commit ff3f07ae99a30006dd85b9d73084edd9355c9db6
author Inna Palant <ipalant@google.com> Thu Jul 11 16:15:26 2019 -0700
committer Inna Palant <ipalant@google.com> Thu Jul 11 16:15:26 2019 -0700
tree 9b2deb7c36a21e826cc70d2650e4664c8961664c
parent 84ed444a53203c4150a519c427f39e18a0711363

Initial check in

Bug: 137197907

vendor/libgit2-sys/.cargo-checksum.json

diff --git a/vendor/libgit2-sys/.cargo-checksum.json b/vendor/libgit2-sys/.cargo-checksum.json
new file mode 100644
index 0000000..da142e4
--- /dev/null
+++ b/vendor/libgit2-sys/.cargo-checksum.json
@@ -0,0 +1 @@
+{"files":{"Cargo.toml":"5e99f3d920503be5fa4b13f52518c9214c4f49a8d74318ec3791cdbf057149c2","LICENSE-APACHE":"a60eea817514531668d7e00765731449fe14d059d3249e0bc93b36de45f759f2","LICENSE-MIT":"378f5840b258e2779c39418f3f2d7b2ba96f1c7917dd6be0713f88305dbda397","build.rs":"fa8044bdb4a4fbfc8fae20d6d549d17800be278c7fefd8e5329b0b2febacbf1c","lib.rs":"9d6b7ce4c141fe216ece45f8f28a6ad5530b341b340e2ef38e7fff0e5da25ac2","libgit2/AUTHORS":"623c6b2b1a422bd4051bf08c6a56842ef1acfa25039d937933dac32c1126a627","libgit2/CHANGELOG.md":"89c932e944f9e13f43d56eedcc2044515d1c7dd5809ac9027e03be1bf0073ce9","libgit2/CMakeLists.txt":"1017c3689b305b4c78a725754b1fb79dd1623e1d4fa6f0effa17ceaec99b300d","libgit2/CODE_OF_CONDUCT.md":"bbb42da81b2c2261fe2781d22179224c5e203144535d33f49a61d4ad322b2217","libgit2/CONTRIBUTING.md":"9eb3caaa65a2e00b22b6ad2c80788189f9c9c49782f8e1fc397617d8bcf31ab3","libgit2/CONVENTIONS.md":"4a74bf6e306485236c52912eff372a5bede620409aa81906dd3a4fc77f5b174d","libgit2/COPYING":"d9a8038088df84fde493fa33a0f1e537252eeb9642122aa4b862690197152813","libgit2/PROJECTS.md":"e3e1f7fc8fb7db989dab4754a38f5665bbbf85ab6b13bc6e6ba4e05d6cb98b98","libgit2/README.md":"7c35c725ea9288083740ea6b4c23bc92b143f82a0ca88b16506518b14b8f2934","libgit2/THREADING.md":"99d405d645678c37146b619b36e79f3164506b44ef116db442493d24731d7290","libgit2/TROUBLESHOOTING.md":"38719af0af50ed2c328c692fe9521f2fe46eef55381b5a4d0346b2a10f501a5d","libgit2/api.docurium":"c1cb3194e6faa84a0d2a15930d24c0c68a0b75ffb3df26fb8a55823256f0f05c","libgit2/appveyor.yml":"4bba27661c6b8d4e65c24664472cd92f81e0ba9ca4f99e61b892e959d265b7de","libgit2/cmake/Modules/AddCFlagIfSupported.cmake":"e8023acd6061254576a6022651a0cbcd1c8d9ebe1105901bc22960b06b595cd2","libgit2/cmake/Modules/EnableWarnings.cmake":"8024848bdac90f96a8060ff51631de1f0e4a78f602f1b2afe2749cbb11465330","libgit2/cmake/Modules/FindCoreFoundation.cmake":"8e1ace5fe47ea5a457855cad091a0641f7311537bcdf71a1b16ce58ac9952f9a","libgit2/cmake/Modules/FindGSSAPI.cmake":"48f9269de462b188b4c81a22bc6dae65d496aa79770aa04fe96d9a6198477363","libgit2/cmake/Modules/FindHTTP_Parser.cmake":"ae7c457f673470a1e20397667555778515e5b5dd4263d3ed8816c7ac5e67d5a5","libgit2/cmake/Modules/FindIconv.cmake":"1db293bb9b74c63d8cbcf2a9cd7ef6ec2c7b6d43b51cc1029ca97d5368c3bfed","libgit2/cmake/Modules/FindPkgLibraries.cmake":"9132bb80cb6d9f7925be275c4a267f91fef82b383e9f0f1214b5e4726c76567b","libgit2/cmake/Modules/FindSecurity.cmake":"ccc6fd877175e4319fb972942ec4775457f4437357e74895298ec9e236244fff","libgit2/cmake/Modules/FindStatNsec.cmake":"1b604915748a830768bb399856084dbafd35a354bc82c0b3d94605501858d458","libgit2/cmake/Modules/FindmbedTLS.cmake":"dddc209a1d02b7599d4bb6a49cd4315fabe32c816190fdb0abfd5c214a470362","libgit2/cmake/Modules/IdeSplitSources.cmake":"0fd931f46f32392f2507ff0ffbdc66c51dc415fe00b72ef44ae3c4776fab1074","libgit2/deps/http-parser/CMakeLists.txt":"869347b1e3e3b13220440059a40bd66de66ebd9632986639967d8ad9c6711b87","libgit2/deps/http-parser/LICENSE-MIT":"2996a1c43ee757f9c997a829d82bdd584052323e73cf02ff8126c6fbd95c2d87","libgit2/deps/http-parser/http_parser.c":"28bd25ddc693f5eae7aa984a36f9cc96057f57b6468312593d48a7b977350c82","libgit2/deps/http-parser/http_parser.h":"d3fd211486e4352f57a47e856a5a10dfce06c46211119d0f6d9935713d2ad08a","libgit2/deps/regex/CMakeLists.txt":"c2d41ba0d8d5e786ea114b4ca1097365c1f63457c3b8d4891eb89e700312b292","libgit2/deps/regex/config.h":"b2ec3e082719b4bfec507594ab1f8a5f8b27cd58095e1c88a64869f0a07ffcfe","libgit2/deps/regex/regcomp.c":"673d72e09e1d4fe35136363c7fe839e6411f320ec51c956e54a222237593b795","libgit2/deps/regex/regex.c":"e22443a2a357b5d03c3cc2d95c04236ee82781bf91504973d1ac2fb03886153e","libgit2/deps/regex/regex.h":"0f5b157b9981d2014ea3e7603008485211386a60bc5f5559fc72833e0a34e687","libgit2/deps/regex/regex_internal.c":"63c1e2f7726ef4173494b5769066e746683c4c2248a42536cf7215c304f14321","libgit2/deps/regex/regex_internal.h":"1071780a8daaef01f5260fd6c3c7bbae9c98c5581d5fdafee8f2fb68d757f4b9","libgit2/deps/regex/regexec.c":"18eb967dbebc6e464f916b2179e674700bc909a6c6439068124d2e6fa1ce6f05","libgit2/deps/winhttp/CMakeLists.txt":"6c641c08d2cb1719c533ac20577f317bfc5ecf27e4ffdd0ea940e26e25dfbf2c","libgit2/deps/winhttp/urlmon.h":"6cdb0f5ce5f0aea2daefc44c4806697ed31ad759f8baa18fb38a5b220ddc7d7f","libgit2/deps/winhttp/winhttp.def":"89601b95ac2515619426ea52ca093fac1a16ef0bfb5586c1385a028947ab6513","libgit2/deps/winhttp/winhttp.h":"a51828d65b1b260a727f596c41cf3257cac2ef6cfebb11726234fd7ccb1537f6","libgit2/deps/winhttp/winhttp64.def":"7cd0bc8dd2c06d288c241d175da06146e940c28d7201fb63de8a75730d09fcd4","libgit2/deps/zlib/CMakeLists.txt":"fd8200f03fa9d6e0e22c8635388edd1912e776178df80d0c3a250dc393207134","libgit2/deps/zlib/adler32.c":"d7f1b6e44fee20ab41cef1d650776a039a2348935eb96bcbd294a4096139be3a","libgit2/deps/zlib/crc32.c":"a04af273e83ecc351bf3794974ab2098d8d960df4044b7b44734c41443ee26d0","libgit2/deps/zlib/crc32.h":"407af59d0abfea84a6507c603eb29809411797f98249614fe76a661def783ce1","libgit2/deps/zlib/deflate.c":"11fd6b0328b65c4ad4b5c204d892a97a9083628a7e77dc47836c8e0c799f8da0","libgit2/deps/zlib/deflate.h":"0ca7fb0cf1dd63001c6e9e4ff93c8dbff2fe521199be51a4dda38a11b44919f6","libgit2/deps/zlib/gzguts.h":"1ef4741cf10441feeca5c8dde2b6c754f0cbd96fcae697d54a604757289a5e9b","libgit2/deps/zlib/infback.c":"abe44873b5af2ea68ea1d281d915b2800f1832f846d2c05442a4711adbe6f269","libgit2/deps/zlib/inffast.c":"4d496ab2a3d29df5fadc3dbff6067e039806aaceae6cfcd09ea77d46c2b848fd","libgit2/deps/zlib/inffast.h":"7d8c1c873ce9bc346ad6005bb9d75cce5c6352aaf7395385be216a9452a34908","libgit2/deps/zlib/inffixed.h":"237ba710f090e432b62ebf963bee8b302867e9691406b2d3f8ee89ee7bfef9b0","libgit2/deps/zlib/inflate.c":"8b6c599c3563c14c447c47db0d7dc9a16e8c246a078ec95a169ddcebaaebd811","libgit2/deps/zlib/inflate.h":"8ec9ac297790276f7e46a961d4c6f9f944fb1dec92401339ec2666973cc5983c","libgit2/deps/zlib/inftrees.c":"1960ca67384376f65b6ce8c08fdb501f8eb33923e11ef5f61a855708c6cb0a8a","libgit2/deps/zlib/inftrees.h":"c510b36402784b1f898be3b049b923469aa92701de2d9195aed19f6b65c0dce2","libgit2/deps/zlib/trees.c":"f2a5f949ea70dde7c23a54c793aeed630a03df4bb72417cd3aa008000c44699b","libgit2/deps/zlib/trees.h":"bb0a9d3ca88ee00c81adb7c636e73b97085f6ef1b52d6d58edbe2b6dc3adeb4d","libgit2/deps/zlib/zconf.h":"9c0087f31cd45fe4bfa0ca79b51df2c69d67c44f2fbb2223d7cf9ab8d971c360","libgit2/deps/zlib/zlib.h":"4ddc82b4af931ab55f44d977bde81bfbc4151b5dcdccc03142831a301b5ec3c8","libgit2/deps/zlib/zutil.c":"f7fdc9ef326a2683eb33c794face54e83c751ec17f3d1ba581847a62af36ddcd","libgit2/deps/zlib/zutil.h":"9a63f6690fac1620aa3cecee5752af618806da438a256b4a047fbcd289cac159","libgit2/docs/checkout-internals.md":"221b9821d89ef60b6b71d5c6b80200bbd911895649bb4961b3dcaa4f5c32d8c9","libgit2/docs/diff-internals.md":"4186480a0882c2ba6177e940be9f04d804d7206cd51467e8226aa964bc090753","libgit2/docs/differences-from-git.md":"30c36445bca9a377db72bd2ffeddf68d392a61fbc60561f17e3590873a372e02","libgit2/docs/error-handling.md":"abf6e8bcf9cc8f7d85c6859a0eb5569a1d8f4ff3f5b4523635b82eaf916621fa","libgit2/docs/merge-df_conflicts.txt":"1d22b5791b72b4c084244888eea37b80b4f0a1dcee9d76991edbc18ecb1df057","libgit2/docs/release.md":"58518cee954cc7173c178fdb8a1ac9c2aacae414a3f62dd6d4ecf73e98a1a2d2","libgit2/examples/CMakeLists.txt":"adf6787f7e6ba51f80d70fb274ed7fc434a590e85a5639e0213570df69454756","libgit2/examples/COPYING":"a2010f343487d3f7618affe54f789f5487602331c0a8d03f49e9a7c547cf0499","libgit2/examples/README.md":"418026aef6c3f2870b7c000df5b4cd7847f644f2fbe52dc9ea0ccacbbe37cd64","libgit2/examples/add.c":"f244a776df48860a3e478dbac0134bea0ecc4276906b62f9444c7d5c51863bb6","libgit2/examples/blame.c":"c74ac19e48ff182308ced7701cbda90f8795a8ff1331ae87d01c7f3afc5abae9","libgit2/examples/cat-file.c":"d70e08e6182e918deb390b722209685acd97390348cf94d3fc0c811335cab76b","libgit2/examples/common.c":"dc90e949c1639d72dd7befec5ae053a9b7a78858316283947fd00b72a4067285","libgit2/examples/common.h":"ddc24d54a2097d8ca2d4de54ad8793b129df7a4042cef87b5051fdb55ae71558","libgit2/examples/describe.c":"589e775269be4f1bc1df418619c080f0ddf51e7f2e39e1d5c48635b074b4ea0e","libgit2/examples/diff.c":"68fb304988e7407e413e8955a53c46b2283b3b38b7508fca165fecd550e691e5","libgit2/examples/for-each-ref.c":"7669ba1d3394f867ab0dfe2ea22c0517730a3f12a9cb3f7a4b8400e775dbc29a","libgit2/examples/general.c":"c0323051fce6c3f5da81f68e1eca3170302f736fb6aef3212eb59c090678fa15","libgit2/examples/init.c":"233f355401e4b5c97e06c8b8547798376fa87fc2aeaa79bf7add5831ef88e7c4","libgit2/examples/log.c":"7c531dab0eeb79287783ca2b00a9bb3ed121c7df76968b93b80e8f39cdf22ceb","libgit2/examples/ls-files.c":"c4d2a23dd4e01e233f74b6823ba247b3adea824f7cc50b89345d94c314161d6a","libgit2/examples/merge.c":"58ea9721e02e288fc84f314876aa7a8355da550ddd44a001ebc36c3b0e52a1e8","libgit2/examples/network/Makefile":"30ab0aacb3196ee990ab9f312ca73c97e8070f1818fccff7507677b3ea502996","libgit2/examples/network/clone.c":"c94cb008000fe218c19d2e123fe2071eb9930e5e75cbadadcddabdfd414b3b97","libgit2/examples/network/common.c":"5b12ef83d93590c6c3200d58a275488993d06933273f92a976c3a0a633851f5a","libgit2/examples/network/common.h":"70515845ff13da9071b59ae20110f459fd4acd4530a8035b8910c14a825a6b93","libgit2/examples/network/fetch.c":"ae26fc5ce9a1ab487db4892ea23069f97332b16c419423bf8b0c179af0ec3a45","libgit2/examples/network/git2.c":"edf2d0b23d80981fe50bb7c09167e179e80cf5f750355e97e3e230fe82d728b8","libgit2/examples/network/index-pack.c":"9f5bcf3208923cff957ca6b0715a93495a896542559024803a67f3264cd50f3e","libgit2/examples/network/ls-remote.c":"33006045a3b8735dad242dd9b355d76b76098bfaf1166a29fd00b47cbb8e0f67","libgit2/examples/remote.c":"0d675a160dc0e02876a99b3b2f2fdca7b89abe81266dde16422609165bfda0b6","libgit2/examples/rev-list.c":"7876b2e4a6c67b53e49b5a4cabc0c2274238e878ff5cc79feb95fb9718b9d073","libgit2/examples/rev-parse.c":"f5d464efbbe322b4212eabac013d0cac321e8e5d0d7bffa8d717a67cfbb8004c","libgit2/examples/showindex.c":"9a57960d8fa93ef02ba6aabc01849dafaa3c73f6ee1c6741e1bd07ae1c84f358","libgit2/examples/status.c":"01e2b757657803965c3dbfbc937fc6ee3e1080fe637054c023f70f142bcfdff3","libgit2/examples/tag.c":"60e33ae54f4a363ba9afa99e59d3df1bee32124e98ac15914e4beccc9e6715e6","libgit2/examples/test/test-rev-list.sh":"256b7db68befaac50e6989bc1ab63d4597fa0a5e5ff6f651c38367fda1d78f4f","libgit2/git.git-authors":"3f26949ee933d877d7797c8401c5d1f77780d3822b495fee98bdb085e9e5c7ea","libgit2/include/git2.h":"dcb1ee56e162d624ea48b8e6b117b5fda311208765fa6cb1dc9c117e54e7e165","libgit2/include/git2/annotated_commit.h":"12c54acb75156e2ac3ac53b679d6a99b764180041be6d3912531fea8b0facb20","libgit2/include/git2/attr.h":"af1491ca8ce2b609980c27299b4bbb3490646c7e8648b693de8d6fab4b4d5410","libgit2/include/git2/blame.h":"632352860dcd0d649750a4c32623487fdeeff9000210669ad537c5ffac2e6b50","libgit2/include/git2/blob.h":"1f52ff355e9af7595d5ae0704ddf0454e286876c88834a648cbff4a324ada79a","libgit2/include/git2/branch.h":"a88c103cd496a6c207f2ea32156576050c207d2e1298b03fc6dce44e77c4c185","libgit2/include/git2/buffer.h":"0e8fdc4bf2f59d3f46923a13651f666b3128a7a9640ebe3a3c8c0f0f919835f6","libgit2/include/git2/checkout.h":"b31972301aea7dd4ec9b3428c9fd857b9eac80d725b2b1d585f60ee6e27ba965","libgit2/include/git2/cherrypick.h":"4aa44e7da960c6fbcba8e6f1b6a7f4bfbdb9ff3854fa7722473d337a60c7a1b0","libgit2/include/git2/clone.h":"7b0ef3e77b298d91ddf0a3c947171068c699a57688834e98ccafcb108692cd47","libgit2/include/git2/commit.h":"5730dfb93fda7f02e06f0edb4ee146d5f0d90b83ce8d36185588d36a2521297b","libgit2/include/git2/common.h":"a72f4afc280f4ae99592dbbd6a89405d2570093846dce8cbb1cd6d6f80b86458","libgit2/include/git2/config.h":"14eed594e46bb1587c2eaef6a059a9730ae91784b4764996c51960ef5e6a6eb7","libgit2/include/git2/cred_helpers.h":"b6cab2f38efd56fe0da379bf9a19493f362018a6ae31243027b1ec5a637d1bd1","libgit2/include/git2/describe.h":"2f5d2a189613a54adcb977e1f385728e5ff22a99051b49b822779b0bad0091a3","libgit2/include/git2/diff.h":"27d15d2c2c598bc44e12089762a814fc88916c1fa69a4aa2567149742a35389b","libgit2/include/git2/errors.h":"4fd4228549332cf00fd535f36ae80e080506d255dfc523987f73f6858204d021","libgit2/include/git2/filter.h":"4013f43c76c36bc5ee562f2ca1d5027b17f40760d6f69543f8ee96c0a9460c63","libgit2/include/git2/global.h":"88e49fa7593012aa9575df08755b907b5b613f43278f477e9ca8e4feedbe6786","libgit2/include/git2/graph.h":"9b70d4c291f69803c51e8859c416f5ff81850738d3c4d1cdca0a44247fbb7086","libgit2/include/git2/ignore.h":"c5693197668116cd130201b353ad472acc5c05f5c382e2b39b050ae955b3aac4","libgit2/include/git2/index.h":"d630e82a53bcf3fc7dea3f51125e813906a7a178291d165dce99b975250fcf41","libgit2/include/git2/indexer.h":"ad6025720b34354abfce9c74892eb4f3dabf6d6d79182029481054daaacae5ae","libgit2/include/git2/inttypes.h":"e2266b727b63eda6d4f19193b6703824fc11f3ae35379ae6f9446c2cccf3f450","libgit2/include/git2/merge.h":"c525ddd8d1e0567791a7b63d425301b0b273bcb47eea4efc0093bac0766c08db","libgit2/include/git2/message.h":"dd9a84083afa7835e4445e444d85756458133ad34c96f8529c2ab942e8ade5a7","libgit2/include/git2/net.h":"2b0e215eeeb942072e8a7d603ba11d23cd58df489442b9a2e7d9552512d148c9","libgit2/include/git2/notes.h":"0537231beee54b3dc69424f312cd42f499b90a5decadfa96f9082754908097bd","libgit2/include/git2/object.h":"1ae55bf4ab22e0e3887f14f1c7cf605d022c1f3a385e3757f6568e6bff4cdc36","libgit2/include/git2/odb.h":"283712832bb13cac24234938205385e86cb4db635d409dc3c3dcb0b101bae42b","libgit2/include/git2/odb_backend.h":"e9275c3dd54048d207f73a99a120d5a9f7d7c6a7a6e9f7cc32136912e9001b12","libgit2/include/git2/oid.h":"3ad36da09a6243f15b0ee4681492364bdfdaa318297bd0a5a6825e8ee3adb3f3","libgit2/include/git2/oidarray.h":"9b89c71035101bd1c315c192b72ce50307a679d212ed4be53c68af74f1d2908f","libgit2/include/git2/pack.h":"0c131ddd7b2ec43cb0e8724c406932cf7a604365196d41370d0a1d8a880242a8","libgit2/include/git2/patch.h":"c9dfe91324fa0884c154953f1645b6354dfdca3b551de04032399e6de865945b","libgit2/include/git2/pathspec.h":"5b482e78f28b084ba7b399b1f4612e58c7b8077e56403d5cb8f2cbec8798eb0c","libgit2/include/git2/proxy.h":"0b1ca6d9b8cc765c44a6e4038afb39fcbcdfd883cfcab42423f5948218fda997","libgit2/include/git2/rebase.h":"628531044aa076c11c737ebc0796c706ff49d26e0ca29b323bed4aef39b10e60","libgit2/include/git2/refdb.h":"77a1b09f4ea49607e7dbaadec51680316e67fc574f822e7f5c92e6e0594c3905","libgit2/include/git2/reflog.h":"c3239c314b3d7bdcb056dcaf7fe31834fdc5905bf98f3e6682d11ad7817bcd4b","libgit2/include/git2/refs.h":"9bdddc94b9428cec546d9c4fae409f1c3e44229b64984935e1be87c9cbaf93a9","libgit2/include/git2/refspec.h":"b46f8b9662c4e37112fc3456a93f1ac7648a3cba32b7a7e5cfcb62466df0f3f9","libgit2/include/git2/remote.h":"a5a5d3dda0b180e5416161bca7fb8c4fa31b826627f265e60d9d6c64b4e14330","libgit2/include/git2/repository.h":"f778b86b8d7e7caaf3917d6efcb235caf09f614bbb2b05a38a442dbe889befc8","libgit2/include/git2/reset.h":"303c3b9ac582a59000be80c3c2acec5eaa50c207112fd42efae77e6f3a308909","libgit2/include/git2/revert.h":"69724276f8e326cc96add6dee3f77d0c32cdc71ecf31b5eec3de34aa5db2770a","libgit2/include/git2/revparse.h":"3447f28f4f811c176bcd43040f68a040111e6c46ad18a3b3fbbcab805964ed5f","libgit2/include/git2/revwalk.h":"99d52a7538ab1024d8b69d8178fd1183971afbe2ff782cd9c97562f51713f549","libgit2/include/git2/signature.h":"a5d6b4b9020f6c72487146463d0361935dcbbeef8efa3741bb016a72f3b0c281","libgit2/include/git2/stash.h":"adf4158d24e0000fa131cfaddb092fada72b0e42148cbe97e911d2c8a36e5f41","libgit2/include/git2/status.h":"74688239fdc262a76565ad1ebe755ce8af4fc1fdf785293448e4c4a01e645359","libgit2/include/git2/stdint.h":"f8e051fb82c10f81982ed3df4fb7572245112567c749a8e4b64883f5cddfc45a","libgit2/include/git2/strarray.h":"bc8661586c2ec8259135dec395514777d0be3fe8078a29ee8be8375d6b4b093f","libgit2/include/git2/submodule.h":"916501455063bef3e5c6822315609a249d84e95b1c714b3a493688d5ad84a838","libgit2/include/git2/sys/commit.h":"c4354e6864080a81890db8c8c853ca8f1a4378a5f23f36c5fa0b80a2433de349","libgit2/include/git2/sys/config.h":"51a0b070a8cbd17653604168f8bd0a75f4bbecc5279a63cbea30e05587cb8bf0","libgit2/include/git2/sys/diff.h":"e341f693acb25645f6ed47c041fc4eda8996a6f1d42905ae4f87fffba22520f3","libgit2/include/git2/sys/filter.h":"6b53b4f0a00dbd47fbf762edff6568698d988e9e2795801b11784450a6747ca1","libgit2/include/git2/sys/hashsig.h":"5677f86c02e557c7897e98d395e83d8168c532916ecfb7f9ca5bf7b4057141f4","libgit2/include/git2/sys/index.h":"d381239cfcab3c3c34b5332b248058da63651e073ffd9b9ea497b0fbd3a2416e","libgit2/include/git2/sys/mempack.h":"133b08d875f014efca893dd34ad9a689c97d855c1df980cb4e40287e6c9105ac","libgit2/include/git2/sys/merge.h":"8f0fe67e0a9f2df3a22a316001595dd46238362a7b0204001af6322c6ee4578c","libgit2/include/git2/sys/odb_backend.h":"26e6bcd82cefe3ecb324ac9eb5f98188841db74cd73a18696a7dc50897d3367c","libgit2/include/git2/sys/openssl.h":"011d45d1991a7d4467b5de5c574718af5b16198fb1581639845fd8d07bef7758","libgit2/include/git2/sys/refdb_backend.h":"230c80406e1e8586c2bf3ce7f4eac4ed6bff6476c648dfee2c5d423dc29fcb29","libgit2/include/git2/sys/reflog.h":"c307ce8e9c8b0483ec45ce34a200f74e1ee73bfea9c4c7b0cc3923e3881360ca","libgit2/include/git2/sys/refs.h":"ee98c1aa0596b1cb409795a94de4891392e1675c42e8877a1e38bd0a5c3fd2d0","libgit2/include/git2/sys/repository.h":"bb380c906d0b70172d02ef082be1184246f3c573d1e1e183d09adf51ad449b75","libgit2/include/git2/sys/stream.h":"b449d03a1b02e18741dade609aa642547290b14d30450625a77da80e695ec0dd","libgit2/include/git2/sys/time.h":"98c05b50edcd3a2c1349bd8fad32edc8e3c47fb45e138b3cd047859714e02e76","libgit2/include/git2/sys/transport.h":"94816faa6b014ba207eea33ede46cc10211f797564014e3fa802b759e6dee988","libgit2/include/git2/tag.h":"d945dcf0ee5a6e5e301809dfcec3d120da8dbca1ea2d59f601fc10574799ab47","libgit2/include/git2/trace.h":"e2c0dac162f8dadd117e73e1254097732dd07d14ad6fbde7d3997da1893fade2","libgit2/include/git2/transaction.h":"9c5b2404e450d628955159840b0b6570f58e85233490cff29d8b23d9e41f1371","libgit2/include/git2/transport.h":"ab5a314dce8a86400658d3980f2b47a202e60681386bf85c9db5cebe568f1a1f","libgit2/include/git2/tree.h":"887a1965625a2cba36a0ce7126ec4a1d8c764c5a325bba2b452f8b6c28529359","libgit2/include/git2/types.h":"2de771ae6b552d934273231df91fb704e9d0e9245f1484ab0ba61cb5b6c70857","libgit2/include/git2/version.h":"b2374dbfd5b85bb81b9b997b474a6739b902b08bfa693058792c1b739c6f5ed6","libgit2/include/git2/worktree.h":"44425271749a9e2f81572684161c90ea393d3cde5d2c3b690567ce791010bc37","libgit2/libgit2.pc.in":"e03f55b445ac78993a06b2dea6018acea775a38161687f8a583d0de371acfe8b","libgit2/libgit2_clar.supp":"bbea1cc011a902c47fc892c866b787b8f5f6b3ac0bda4440f753217c58eb8b3b","libgit2/script/appveyor-mingw.sh":"682d981e9d02ec278839fc980bdddcc4dda95f1dc5f372b42e594ecfe738bf56","libgit2/script/backport.sh":"6ef93a8c4a15ef74d2639638db3b24d20a76fc31faa53b1c34b07e3759c78fe6","libgit2/script/cibuild.sh":"6d976ab1da8c1fbfacfa5d6256e9a2a4b04b763b9c3bc799d43139536b1272d3","libgit2/script/coverity.sh":"b35a4747d1def66d8e446775676a903cdb2db8ca3f4ff9e2af393b96e2353e97","libgit2/script/install-deps-linux.sh":"5a47bd53e207acd9c040d8989a767fcd11f5227ec570cd0d4f2b8af9725cab31","libgit2/script/install-deps-osx.sh":"16afd7202bf531d5d0a3ea33526180bf8aee6e0360733559aa0ac60315686e61","libgit2/script/user_model.c":"a11ef948e568ffaa1a751ac5bd19dc566bd9b343b8f07e6f5fb3f6e8d420c0e9","libgit2/script/user_nodefs.h":"c536d2a4abe570060c393d2516cffa3f91d3c3107380ef1eebfedbfad3c43ad6","libgit2/src/CMakeLists.txt":"3955f63185292f0fafd82ddc89437a66220d2eb9a565ff50220ee3508017a110","libgit2/src/annotated_commit.c":"eec9ad9b8d4b34c70b464b78ad396e9e4a0d189aa5d75534334d01e9e1c9c995","libgit2/src/annotated_commit.h":"0c685dee827676a1d9548cb57d017fbdd20bade9ea78da62a1403e078b1e2fe2","libgit2/src/apply.c":"90ea4c554c42e018320ace825e746818d56f19630d0324c361c5b6e17eaac348","libgit2/src/apply.h":"96f82148795c56914244adc61eb20a6404250e6b9f1cd34db4ac78e76a47c72a","libgit2/src/array.h":"211b0a4268e855f6db8464ee164130f201fa48caf6f01ce3d93cd5e06d7baab5","libgit2/src/attr.c":"48053e39dbb330f0e40909b55a2dae2f7a9308acb5e709a5c075a7a93d35a927","libgit2/src/attr.h":"c940426d88f00d1510d2698897d5fd1b9270d91ec0c86a7df10b9d07f598171e","libgit2/src/attr_file.c":"16366b57210291e1dde6008f7c99b9c05bea9ad5db545d629c8163ee9107e340","libgit2/src/attr_file.h":"b55be6ee92d50b2881df04d441ac82693496381cc6cc16f73135d232c7375f30","libgit2/src/attrcache.c":"b39b00c460aef1c82824c8d2a4d6b4aedafe2ea391976883ab803b18778bd009","libgit2/src/attrcache.h":"a664e35bdf53be510489ccb2b92d3642a82ca8c70ebf4f49712949c7319aceac","libgit2/src/bitvec.h":"281444c865be87104cff9c1b3998877a67bfd92af4b0e5b9b034fd48f6569f7a","libgit2/src/blame.c":"5eb710a299bae7ac109431e0cbb31250d81a5206089daf948c58bdcbad80b4d5","libgit2/src/blame.h":"ffea3556f6fc8b3cc9e8313663f411e5ddf7f98f947d65778cd181213471d159","libgit2/src/blame_git.c":"474e82ed3c1a7c3db8709774e4d587fd5e6fa8c60f3fedd36aaed9dccbda02ac","libgit2/src/blame_git.h":"9b813f16b93512d27d93648e53d1438d5b931024701273b5976c1da41868e286","libgit2/src/blob.c":"ca4fcd9cc58814dda0f57ff3be2a73461661bf1a1314b0f7d99d8db51f80d020","libgit2/src/blob.h":"e760304f489d9242ff77ec579f174045f8c712870d2804f11fa60bc3e506a102","libgit2/src/branch.c":"acc4cefeb073bc6b54e21581d16bf071870d4494cca960b9c081ed240b4fc05e","libgit2/src/branch.h":"c73beffe8a3a21390d49f5cc99601accb3e03d82c150be70da823548e031b6d3","libgit2/src/buf_text.c":"fb9a68883ce3dad454f99531f51b22cd91f8083fee4647fd5c58521c9c5279a2","libgit2/src/buf_text.h":"4ec92a3613a02bc4ba977680e6d96e2eccf0563d43a9693232f8631866174e96","libgit2/src/buffer.c":"21418a940e27e9530a93aac51cea64da0348ff03ea56c23b61d69079870e8f84","libgit2/src/buffer.h":"1160f70e20e19890e6f7e41255dce1764da36fc2a64d26f7bc58dc39a322fd57","libgit2/src/cache.c":"729b4af66acf66c225ef8cd766be4f23a226ba8b3c739f744de5a4d90b7caa8f","libgit2/src/cache.h":"2b6aa11a78a28ebf470855b99772f9695bf0eb8df24c01811ecdd981fc2ca92b","libgit2/src/cc-compat.h":"ad3ec10e26f6d118ce7e50058e69877cee42d18e17f20436523a5180a88e39e1","libgit2/src/checkout.c":"c801b3085fda03920fdccfaaa6b6683310bd2db9bfbe65159c9b0f42eeef72f3","libgit2/src/checkout.h":"deeaae59fbd6f4cb3d6c5b67133df66832ad3e49bc9585b6ce9c5d0aa4aa6ef0","libgit2/src/cherrypick.c":"2d6295717293eea883a8e17505824e1a8097124ab20774c12aac0e8972b18036","libgit2/src/clone.c":"ccd817bd95d68a77ed291472e679ed5b496ae47956ad08e7f60f2333a14ebcc2","libgit2/src/clone.h":"b6748c9ced7f93eb57f967679b67c8381e2fd038921aa4035a4e24ec482d6f6c","libgit2/src/commit.c":"f4b0a6632fd51026c0ef72c12e4cdf966ba1df6e9d7a34cb7ef10aebc21c283c","libgit2/src/commit.h":"c1954b59b3f62645d9456eee88da546f72061d76fe8dcbee3a7eba4a81189af9","libgit2/src/commit_list.c":"68f41621d3fcf95c67587ed6927ec2493bd93f295f41469fcb942e87874d27d3","libgit2/src/commit_list.h":"8640d671d1785f1be371f72b06c332675ae85ab03c65db12b7beaea5f9098c11","libgit2/src/common.h":"2ad0faaf8221c2877581dc5266fbce713c3285b01165550bd56ef199b3818005","libgit2/src/config.c":"d27ae7295d1f4c9eb55c5eaf39b08474b6ab0b005929887bbe4fc2271072a800","libgit2/src/config.h":"744b2ab194ebf0d69532b790f54d89067d18e021c1c3dceb23f5aeaf4c7f4fea","libgit2/src/config_cache.c":"0feece1e15c64701d9967ac74f20765d86e3fabd6a1d0f2e4fb7446c7793840f","libgit2/src/config_file.c":"6dea9fcc8e7b27fadcba7b791bad4e9e699128d093d23c5be5f84448f90f0057","libgit2/src/config_file.h":"41127f8e0f81428c883784e69816f421bd5d5afe0db7c1d17b74c1dd4599ffab","libgit2/src/config_parse.c":"40cc3385da873f9df71903d678a4a2b599a55a3217d010eb5b9a89061e1c7ad9","libgit2/src/config_parse.h":"0acc8329dcf1bb4db0a9294e7ca87f35750d4d48801c8da87a99ec14bb8789a6","libgit2/src/crlf.c":"c89f72be4ee785350ec232a735d5b1a9badce712e272ee051315c38b5a0f91e0","libgit2/src/date.c":"f25e34b3a37facbac7db64d60708d9021d0fe2a2492ebd32432399e0e3ad7e90","libgit2/src/delta.c":"ef64aacf20c3e5427535b77553486640712418fbf5df9c41b995221e8c5e9ec0","libgit2/src/delta.h":"c757526292144083a0e96e7ab259080e83158e28c4819c4fa8bc2523aec12a59","libgit2/src/describe.c":"c2f351318bb2ccb20430b5a6bfff38051293317f36da028451bf81776295fd52","libgit2/src/diff.c":"ba25c45d74d3a44f9fcc8842592b0a2dc6c4b2c9e73128e21893cfd804c2dd3e","libgit2/src/diff.h":"06fc73f98ecc56a5788c0ab2ad8aa68e1fa06579ea1695b1fcba0e0e3a0775e3","libgit2/src/diff_driver.c":"c8d84f9b8e7993ac03e031b192c218be2a4f1773dad17b1c85cbc6a33fe3ed99","libgit2/src/diff_driver.h":"a59c56162e5ee30af5a831b45fcf60833a5a622c05a97b6ac052186a507ded01","libgit2/src/diff_file.c":"7c5e895a60a1659727fa42b53d203813fd00a0e3a35e845342d9a2af29af4c93","libgit2/src/diff_file.h":"c4155c960e8e6d773b86161ba01c86f2be5b3e7fa0142747ae6ba1e039676044","libgit2/src/diff_generate.c":"5513595ddb1032b128bfdd58976667320f4fcbc17163a4eea125a87ae2390e59","libgit2/src/diff_generate.h":"56a0c3b70649ff84fc9c4027e9923fa8a60aaf9291e2f6d313192d44035f4d80","libgit2/src/diff_parse.c":"97315c0da6cdcec2e2e5fe778c99aaeef95f36a03eac28ac70394a4fdf935b2d","libgit2/src/diff_parse.h":"8902d9ba9102f10898c14d0a41a8d5823450527266908cbbb06e676309e23f56","libgit2/src/diff_print.c":"6b2a855c9d88d5ee8630c2f0e6c99072df606aa2e06865a94492d6ac3ee8d3ae","libgit2/src/diff_stats.c":"a9f9ffacb1d7fdc1b17d3338cab704e44416264c036906aec5445d7c67722b32","libgit2/src/diff_tform.c":"896ff97d6ad618bfd3956c65b534b9eda8a01f8896fe03d600bb5231b193a3db","libgit2/src/diff_tform.h":"a4a7433036cefffaa9d968ff45244afb4957313cd9c28980cc102f172f9eaf5a","libgit2/src/diff_xdiff.c":"374161f2eb3a968c7e17728927561272006ccc53d5348b45babda977f89a2269","libgit2/src/diff_xdiff.h":"8d083e69b9b90a5b937fdbead37dcc8e000495a16a7139ec600dda735285561a","libgit2/src/errors.c":"b7e1635a8dbffb9778b4b9b736fa1d888576751777e99ea4f939c031917d9a4e","libgit2/src/features.h.in":"dc2a72cc92799aebd011bf45d2b73a10ce1e16d3c59588e410e8996f9c9f97fd","libgit2/src/fetch.c":"0289fba0a763e12d40e5a7cfabb20f87f1e695d3358aa090688672cd5b61daaf","libgit2/src/fetch.h":"93669dbc5007dfe99856c76d35ca82fd25bcc59f3b5308cd0ca15a14d9fa865d","libgit2/src/fetchhead.c":"151deeddf1f3ba879beedde06e587f1b11912065b4de2297ab2f930efc2739da","libgit2/src/fetchhead.h":"65681769629f670afcf739d582bb7ae90f702f0c6085de3f26b79fb3293d1dc7","libgit2/src/filebuf.c":"b00ec679cc88d359942709d830272a8c960e5b7fb5aca11276896ef6a52d598a","libgit2/src/filebuf.h":"9c3a10f9af8a33e71b731e81d6bae792f04fafeac3beb6ee9b39ef0c9bb43b3b","libgit2/src/fileops.c":"db28a84fbfc985124978df89d414ed37add032c93795aa5dd7f313f9375d0ff3","libgit2/src/fileops.h":"6f3b329942aaaa5647e08758a9c9952980589103d1c1a519be27be11d499ce14","libgit2/src/filter.c":"1ca8139f35f989146e565dde8152b33315541f6ec95094b024d2d63f14b25c7f","libgit2/src/filter.h":"89c0982e5888a80368f908855980cc965325b8c3889697e7ccd6afb48412cc3c","libgit2/src/fnmatch.c":"d55d1de11ab37a093a0fd6764629900aa57a33fc30339684535ac1233b63a18d","libgit2/src/fnmatch.h":"557e1ead8bdf2b75023b066d92f3f0247d065a793bbe6fa6616bb6219359c0ce","libgit2/src/global.c":"9da8e9e6f7533ed54c56a60f6b090a09475749175f8014abb0edb96904048fcb","libgit2/src/global.h":"20e6c01113aa2e0c374f2e2fd538d7e57d781c78e3aec1e15b7da69dd5830032","libgit2/src/graph.c":"796426d52cbf8110cbed8db369ff88752c8100de4fbf53da31dfa9b0044632dc","libgit2/src/hash.c":"15e44532de1e702dd6b1c9747313f9dd542784556e467353c6654dc292151c89","libgit2/src/hash.h":"f1c48b0cec1a458e2be05d79081cae8d60e2195e905636b80745baea2ed2a93d","libgit2/src/hash/hash_collisiondetect.h":"10fa50e9f05004b5d86d519b90201d9e3be99adccd4fb9ce579411a160e2b3ab","libgit2/src/hash/hash_common_crypto.h":"7ca1894092007f4d33bc17d3f1a8e7b5cae1127ce544a6da1bdcda8ed6c4ba1d","libgit2/src/hash/hash_generic.c":"bd282d2de5e28d9ae3c2631c237248af6696b387e676dcc6f15a6626b81d1db9","libgit2/src/hash/hash_generic.h":"d183858837449de5837007c2113de722e9ca98f2246daef41d1564b0f738adec","libgit2/src/hash/hash_mbedtls.c":"7d70655dc43da56255c8c4f9e57c245b20996a1aa6b65926513b7267d691e12d","libgit2/src/hash/hash_mbedtls.h":"3fe5655a257020ae795e0268b9a9b2229c5837ce288177c5bf0f3cf7c6827349","libgit2/src/hash/hash_openssl.h":"5ebb74435019d90100542e3ed3cddc7609ea4608b821d3a0d4f9ffffe8e57836","libgit2/src/hash/hash_win32.c":"18d0167e1c0d443c671ebd9056fe30e0baf898df451b5c53eb72820499a04f15","libgit2/src/hash/hash_win32.h":"f6be087021d651c4208542a2694dd70d322be174104764cf0fdd682b12b2022e","libgit2/src/hash/sha1dc/sha1.c":"d05722b95a07262e923a9293dcdb98319411916c4dede2ebc03a5818fb4b509c","libgit2/src/hash/sha1dc/sha1.h":"78f97f092c20329d1fa8d9a8cbb3d53bb90be19cbc49f1917605a9ddf520de83","libgit2/src/hash/sha1dc/ubc_check.c":"7b0db83569ba82965dc0d16e51e9ad85167cdfdab343f9a02c2c475bfdd93956","libgit2/src/hash/sha1dc/ubc_check.h":"4a140693701da167b4709c4c1b330800a0c29f2a065d0d819567a27b3171a09f","libgit2/src/hashsig.c":"06a6c68e79870779351837485e415e9ecd12de9584eb9e97d3f7d5df74d0bc07","libgit2/src/ident.c":"b4d8d98ec1cf7e1fb395f365ae8b7c1ca88ca8a66fd9d4da5698f2c6a86e1c12","libgit2/src/idxmap.c":"481808c9954e15707d829ddf408aa4c3dc7f807a012a20db8232f26878a3f72b","libgit2/src/idxmap.h":"f81e540c4c4b7d7789e5904592b7f7922fc0435b5ecb816db02735d39d0fc29d","libgit2/src/ignore.c":"17b2fe8fb202f605d039e292f9be892e2379375bf40947701cecbdd0193e934e","libgit2/src/ignore.h":"8189ffe01ffe66489fa19f26c960823ba781e5eb35d93f8ee655b06da26ea96b","libgit2/src/index.c":"da8562f5f6c9a2dcefa1670ab6eed39e6c1394ce62012e1a7206695eed129492","libgit2/src/index.h":"4a89fa2c68aad3edbb6d081003207d4441f5fb44fe198388b6fe84bb4651013e","libgit2/src/indexer.c":"3eea0df361fb378fcaf24d240e5f8bd4ac474ea5d0c8b5c19675a77aac61177f","libgit2/src/indexer.h":"bd32fd65a3a7c6014e3e9846477b060033102c8c7baeb097506074f99c50a434","libgit2/src/integer.h":"ce872c832c3dbc9117e5123c01a55cdccd8fc187cab991bf7b7125f957082acf","libgit2/src/iterator.c":"d8802a3967677b35b21a7aef2656f53d533023157a6b314b8092060f43cf24ff","libgit2/src/iterator.h":"1e2c4d94f98b8a1d3e5f54006a6f2633c55f3ea21a114922328957fe289829dd","libgit2/src/khash.h":"cbfcf6626abc93cbda3feb41bf14be91f014298b3d770a26dc923a59ff9de46a","libgit2/src/map.h":"af71c423780870aa68f525aa0db4ebfbc4f84e46bb9105f14a4c60990c54719f","libgit2/src/merge.c":"519f293f5e732268c1656bda137faf3fc99dde618b33f9ead6c5d9c15e4bb2b8","libgit2/src/merge.h":"a82c5435c9b9b25cc5a47c5b1396d92349238b561b537184cf7bca57ae2650de","libgit2/src/merge_driver.c":"5f8117c4d016480360d906922e7ab7db0a561f8cbdbf04f67033398944262ad7","libgit2/src/merge_driver.h":"4f56c2965330a5cb08b9f26d6b83dc4e15fced9419540d2d793f2e75049bc121","libgit2/src/merge_file.c":"6bfa2d72f6381c3d49f68ed327e70668948cf0ccb11dafaf113906a552eaf285","libgit2/src/message.c":"3f8b9aa487cd068319c6ace315d77824e28adf2360f8c96182952a3efcd341c2","libgit2/src/message.h":"7cabd6fb3da32197a5564061b2f4461551263c207810add923250d9127e3e537","libgit2/src/mwindow.c":"cd601ee977d5716c9f5853aa305d9498d66d0faceccab40f96559b8e5b8c3617","libgit2/src/mwindow.h":"38a5bd0f5cbcd5d5b2c8fe5b31567c1d5be7d92f615b57b7c139ba2b2e8dff95","libgit2/src/netops.c":"fc552144f6ec24d4f49554c6dfba4d5d8d03814912e135a683f06b072d7e28e4","libgit2/src/netops.h":"ee37acfd6a4fbbdf87b688896248e7cf21b9d8e0cb15a04960beff62061d9e53","libgit2/src/notes.c":"6a0d165ff36538f14c818e465ab6c0123973f31f15a1a40da62d121fbfc2e8ab","libgit2/src/notes.h":"650f92bbf875ab194b9e1d041f06fb8332bf5f402ea49cde528a81d2eac05694","libgit2/src/object.c":"1393352d0a02830c3f72cb0ac51e6f8dca2c4ca5fdbbff042a12709a3132cc03","libgit2/src/object.h":"042382a54dd6bcfd98f0f3549a68244619856f4cdbbef20d68e82f7e73a7394d","libgit2/src/object_api.c":"05a64c2342969eacb4d292916943883f5ea7e91d11c1dbefd155fbaa394de1c2","libgit2/src/odb.c":"61211fe6117d6c170703d2fd0b7b1874442e36d98f9eae3d8197f5d7c6b64829","libgit2/src/odb.h":"b90c00b5f680706a062f42ffdfc5e5b9b976e6a9982110b27f640ff216f5b827","libgit2/src/odb_loose.c":"d12406b44b7f191df22ce0e2d3fc59959590bf3d19e7e30ff1215804122b1aca","libgit2/src/odb_mempack.c":"6c1b6ef6a856cbac5a448341288c2692847e0d23b0a6b5249c782108412786fd","libgit2/src/odb_pack.c":"2c556e94bc51871729be80aeafeb34e0d67a4899018b23c1b0685136e3c291b7","libgit2/src/offmap.c":"ee915148a14fb771c335778a329b4ff021a895b6d9395f6ff4cebcd095955ba7","libgit2/src/offmap.h":"10c650325325e83a286cdd29557b05f348d1f2a52632b4ef55501da74eb6039b","libgit2/src/oid.c":"c9609329356129863b32122cbac8dabf346bc770417be4c8f92bcdead6420ca2","libgit2/src/oid.h":"322eef4b2dd9b1f78f25b59034491f3547353655d9fcc9b6fe5a1ab348cb1eca","libgit2/src/oidarray.c":"7574a777c9d92ce2ee3f0b24673fe43c4e5fdaf4203a281c2a69f658523f2025","libgit2/src/oidarray.h":"17a745a4d1f2c464b91080279fb4a3163bb39456be5c7e9d6c8195724cc3cba4","libgit2/src/oidmap.c":"e4ef444af3438d44b20ace069071fa9c68d3489972909a3a9ff22402c645b8b1","libgit2/src/oidmap.h":"583c66d4d5a4293ab612d28be471fe1dd85a6335e293a4db78e2a12c7b775e2e","libgit2/src/pack-objects.c":"3c65ede0f5598dad88706ecdcc8a5daa01c5cbe32a0de8d18eb68f13847debb7","libgit2/src/pack-objects.h":"ee9922706371f00fe44d7012c0cb59eba9041af2d6e56fe7db4df99778a83272","libgit2/src/pack.c":"f33dfca3d5426a241599157fe9c309f1d734214c73cd6e12dee4cb7739a112db","libgit2/src/pack.h":"006699fcbe86cb321c3ece448192a2ac79c254eebc43f79c579ff5a3192c557b","libgit2/src/parse.c":"0623f63c2901b5ffa3ebd078b92e425012010d29cd26cc5429a3fdbee2a75de9","libgit2/src/parse.h":"31cee481b9de89af5cd033b11e4bf909b7885d14398a8fbe31cae39b08c5bfac","libgit2/src/patch.c":"e5d3f21049ff6af8290d72e930e7913ae55b17a69bbb9bfa7b23ffc834ab7fa8","libgit2/src/patch.h":"b6e844a48af7a8729c37f9bab8dc794907534ff723543260781491c133930120","libgit2/src/patch_generate.c":"b0b364b4a52f1ee791d29a090e5b30abb8d5de1833e8710855d60c5cf0214a22","libgit2/src/patch_generate.h":"396a726fd8546630bfc85fb4b1a1fcb3e085aca4b7263f0042aea1b12ff02e35","libgit2/src/patch_parse.c":"d0cf2c5e5a0f7b041d28cfe59ad44504fcbbdc3085266704c87abe163899ffa7","libgit2/src/patch_parse.h":"6883a184830f4c59427177eba5462d27737706a1be899db35423c5ad9d6c8c4a","libgit2/src/path.c":"9edda64de107a6aa1efb1f0e3046123a80c62f60109c283f8eb252244e923ab8","libgit2/src/path.h":"1772c28f5ed858dc433ad359339aac6824b0f15382a3470795c2c5aa67ad98b8","libgit2/src/pathspec.c":"381be1e624e7387b32f8bc52ea8dbe2ad1b7f99661999878fdf24be4ebb07164","libgit2/src/pathspec.h":"405f9c8598735d84951b8adc40e66617dcaf20f5141e5caa187cb638936041c4","libgit2/src/pool.c":"e9175293887a2ce26cb05b4df38c1564692d9ac1e75a67f5d8612279dded93c3","libgit2/src/pool.h":"0083f5991f4e5bfa6eff6d28de1085a2376972848718993cc621c29c7e115e55","libgit2/src/posix.c":"c5eadaaa5187425ca4adcb318a9dcd411c0be305210ae1e39733acc8ffdd8522","libgit2/src/posix.h":"b64da46da1f93d5e932b9ae0f22f3fc9ab3bb8fb8dcdbd0ef66c9babd948246b","libgit2/src/pqueue.c":"d5cd8f6c5639b50898fe0f9354dbb29de1a0be1d20c879242c8423907466c7c2","libgit2/src/pqueue.h":"c4c98b6e99fdc1ab33906a1d659ba113a2048890928f158e9031caa35e385991","libgit2/src/proxy.c":"5e586374b778a3af909c1bf5d922c7fdbac580d7399065d8300fa6016d64ae66","libgit2/src/proxy.h":"e195b1b88c11f9d02aa8f02925fd7f11cd68c0361d0e7a6a477f4a3a5cceb896","libgit2/src/push.c":"cb2dfb4e1f3aa6f515dd15b8ba41915b3706ac1263a01b7ddc3dbc7645f58cdd","libgit2/src/push.h":"9d51feb1c1887fec3a21a7b3f2b24dff90e0716c7d99af7925169e188c46e946","libgit2/src/rebase.c":"576edff9d33a1adffc37218058afbc699f88f83ae00cd355712acf675e11fa14","libgit2/src/refdb.c":"b872a564a63b1dd7646ed5ae484fd0a5c66c085a5076dfcbf70bd73be7df5291","libgit2/src/refdb.h":"56c3c500a704fd792eba6bc91546482e97cf038b08158beece1c4cd69c87071f","libgit2/src/refdb_fs.c":"fd32487bd4d222f5c136f55683baf6985b071423f8fe6cadd1d93a76c55f7c67","libgit2/src/refdb_fs.h":"e981d3df86d535ea91561853a7754419a2c95a3f72313171f5f6e0fe6d1ecacd","libgit2/src/reflog.c":"5d80a65395c241e30a2382cc99c7bf6908bb0613996fb353271e76a089ae5c0c","libgit2/src/reflog.h":"898ae0bf378c465673fef1a4221baa2cf6165a0700949952971f743ca73075da","libgit2/src/refs.c":"952875c847903486784f0a96cef204ccb14cca0c53591e3f7f714de6ead423e7","libgit2/src/refs.h":"53fe26a24f462c7d8345700221af4a903365d27d21126d57e22754976c950b8d","libgit2/src/refspec.c":"7cb138a095456649e818c5230538cc2033852ac2b3e53a296036c3f91d35fc89","libgit2/src/refspec.h":"d4a797ccaa3625bb99530b32f05d0736e08138ef86855abb0ccd08a17656d8ca","libgit2/src/remote.c":"50daf961cabdf8e7acf3b30b125e80e6ad5d0bb0ca259665442a1246590fffc9","libgit2/src/remote.h":"fc5247cd71e8580e8abf8cb492b6d533ba710399dfbaaab99db334d6f551364b","libgit2/src/repo_template.h":"bec227c595d193802723f81765487da76beaffafae40ec05b76a4db7de153c01","libgit2/src/repository.c":"694f6db57b402d9321f0fbeb5f4da201c82bb47fc30cda95d4a9f9ba25c5f35a","libgit2/src/repository.h":"61a3330643e07e4865e118d46b71091fb2c79afa3e013a79f05752f192e8a232","libgit2/src/reset.c":"45f58b48cc3939036b860f2e085e7683d7f29a13a031e6266168337f1e82534d","libgit2/src/revert.c":"61a698c107436b8a484498835c3776fbe61c93acdcf588da67df4eb37fab3dc3","libgit2/src/revparse.c":"77679768cb4e9b723c02109ded69cdbedf96a5672a1b30505c4f7ea4a2c1a385","libgit2/src/revwalk.c":"f52b92784af3d93c3e0bb1432327b4925d109721304538c3c018799428570eb3","libgit2/src/revwalk.h":"788def19bf9c5979004e352b8946bcce9432602b950b8578a45c0065a74b223e","libgit2/src/settings.c":"d15c3493345c2dc80420a30aaa874a5756a183e23c1a64e8992af006594a0a2b","libgit2/src/sha1_lookup.c":"95d24473120414853e34972e200d24ad14254420b32a1d9213042e3450eb0956","libgit2/src/sha1_lookup.h":"904c09580175aca72ce97e5dd972ca74bcde4df726700f519d21e157a99726ae","libgit2/src/signature.c":"07b369d0f1980a3ca4ec280c85ca5c1beba8f5670eb3b65fdca96f52706558fd","libgit2/src/signature.h":"766717ad4c2fdaad4b32f5dc5710f14edcda06ac2f98d98c24cf21a6620e6ff9","libgit2/src/sortedcache.c":"de906476aad69db03532a7eeb7d7212445abdeb6deefcf605daff5e42f0037b0","libgit2/src/sortedcache.h":"3f736131f05456af75a5041088c018b014b807b372cbff1b0591303caa68d0c5","libgit2/src/stash.c":"8bba17543218cd70f58eeab8e50cca3286db3905dd13d22616c9483ff456b89c","libgit2/src/status.c":"aeb4881d74457564e9da576576e97ad62e5f9c69fdcdab7dfb88e1bd2bb6f6e5","libgit2/src/status.h":"68ed612f65430563ad5b3f50973b360f583c5865e54c9b9298eb082d441c4e79","libgit2/src/stream.h":"c8bb2d2fb304144ea5d69e5360683b2f3a79d8ffabe416363a20fbc8b07cda32","libgit2/src/streams/curl.c":"5d5f7df51a8c93eaac4502b86f387bb6d63d14d4e791ffb794e2d391e064d99d","libgit2/src/streams/curl.h":"b768f98ee17f00fc25fa262f3656e30434944e763f23edc9c7e0425eed0b7333","libgit2/src/streams/mbedtls.c":"8214b5a0b3f4319fd901c466bfb7d2d62a3496b36b9f8f839d08be38eb482ca3","libgit2/src/streams/mbedtls.h":"23ef372ada0e05e1fa5ac753b0aac40643e52af2bcd4e1407c59496a9ec61c75","libgit2/src/streams/openssl.c":"74892dbc65a4515bd4e1fe22562a2ce28a733a45070134100f972f45e3c47480","libgit2/src/streams/openssl.h":"0ae58cd2079cd0ad1d9156eeaeaca6dffe52e80305635b3792b37e4038335673","libgit2/src/streams/socket.c":"c2f6d2384f31b4d39087ff6c3fa19087ee8cbeb9ef9a1eeedf8def9c76e0f396","libgit2/src/streams/socket.h":"6ed5745f368fb167f24b8a733be0c2272f5bceb9fc40b5c550463428533c26f9","libgit2/src/streams/stransport.c":"352ed18e480587d791dd868d02661773cb632dbb6e59b4430bf754e8b32e79ec","libgit2/src/streams/stransport.h":"d24155fde168a36a4745546dfe7f7ebf343c933b3a68bc366047c3cb41e7fb61","libgit2/src/streams/tls.c":"87ad5f1ea081fceb5d6727f71a4df60b81c08fc6451140fce2c6c332ab28c32b","libgit2/src/streams/tls.h":"d0643133e2da9abb5cf49159de976028e2804d76b59b8a29bad13dafc5a20b6b","libgit2/src/strmap.c":"6fa6121501cbf8f6f47d7a2abeaa20a70383a6d26ce1d43dc8e85c4c7f9d96b2","libgit2/src/strmap.h":"082988557b7935a2c4d722c23db55e574e445d3e206aa99ecf93ae65298d1a64","libgit2/src/strnlen.h":"27e73ccbe8be7c5bac1d022bf59f2458cc2998d0222e7658a687e02f89fcfd17","libgit2/src/submodule.c":"98e6dd0e1afcfcd6b0de224a0a549c4a4bf27472d37a0b74fec1e8804db50867","libgit2/src/submodule.h":"d432ebdc6f61392ebbba61daa7b55e161d321c1271ecf9cce6379e3e8d2f29e3","libgit2/src/sysdir.c":"9930c0a182c17c5e55be87b691207cd764acfea3bc8bcd90c75dc571346ac483","libgit2/src/sysdir.h":"cea646b34993e9011dcdc132243be3aab7a75d47c4c4ead50c250df9fa35c299","libgit2/src/tag.c":"dc964fa3836e4c573152b01bdbff0447626220a09ebdd488c55f15062de8932e","libgit2/src/tag.h":"43bdcffb1097cbacf732d6d38823c7b5bc84dbbebb61a9dcfd52a5284cf621b8","libgit2/src/thread-utils.c":"cf21d34acd4971927ee8b08de4b35cf4bc3bbb05563883c70145438ce7634dc1","libgit2/src/thread-utils.h":"227f69716555c45a9efa5479120d51206f78c5ff1501de8de3988ac7f2b4c03a","libgit2/src/trace.c":"86220ee758bafd196378116b5dda9b25801f5673a1c55563bcd5a097efe3c5f3","libgit2/src/trace.h":"d7362d28a609d7c678ef4d20713dcb56590d8293baafb021094c61d67dfc2097","libgit2/src/trailer.c":"e37db2466b8c4b1d6313626ad5151a3fbb10e5fd36140d1e5594fa97c0e55ee0","libgit2/src/transaction.c":"2d2b3d1ec18e1d2a30d9c1f40dd170909ac28da58b0362b7493edb96bf53697f","libgit2/src/transaction.h":"42e4b38d1fc7a8d57513da8230fff2f11ea4e1c2907130f99d77fdd2f099fc62","libgit2/src/transport.c":"86c024e84a220f64d56fe77a6a7025fc0ff7440baf77e220ddb58ccc44d05745","libgit2/src/transports/auth.c":"f174e0355e12dfb20b77434edc22937ccc9c3c747a58ded00d601f18cda0116a","libgit2/src/transports/auth.h":"82eb346c1c3f92d9e8397e40fe2575f5f3f1e862ef98211707c63139e2c8b1c4","libgit2/src/transports/auth_negotiate.c":"077b7580365b3c414401a7a3611c02e8d0e6b115b444e4d143409d12c06ce3bb","libgit2/src/transports/auth_negotiate.h":"c776af4b5843b9b91dd7390bde9955c067b4cdf48e8340b2a4c262dc466ee21d","libgit2/src/transports/cred.c":"ee1fd74f8c6e02a516563615c8b268c3bf9e05ee13756a8fbad85a636df62b38","libgit2/src/transports/cred.h":"f60f04d5b1c869578bb25959ac1e5480ec628317f82820ddf13a72a245c6de57","libgit2/src/transports/cred_helpers.c":"1173f709504bf2c97dec66ad345c21a913e39f3efda0d195df9e4ff7cee89793","libgit2/src/transports/git.c":"bcf965b986ab8e52ba7115e79afd01cbe34a3190cc985fe45809336d011dcdc4","libgit2/src/transports/http.c":"c116b15297a8d3a679b7cd25c0d80fcb9eca5085aa8f9c41fd8ead909a476d78","libgit2/src/transports/http.h":"994d1226c40113745dd85b56f0d9f54dfa59494a60dd7ba24b2e3fd1f597d221","libgit2/src/transports/local.c":"39de60286441ce3f26f1140fe9de52a1766180cc9368822a15225b1cf8e01da8","libgit2/src/transports/smart.c":"72533e62452c4978b99a20a09e7992258c6c4ac23cd6990b478d335ed06e0dd6","libgit2/src/transports/smart.h":"e1cf5de49a18840d8cfe3b64664807de81abcafa2af2cad8e226ad7b03769bd5","libgit2/src/transports/smart_pkt.c":"d183eeeb1c6c50c559f07e54842562c5b1f15c364e0eb4fcd274fe3e57640f7f","libgit2/src/transports/smart_protocol.c":"1543ad312506f38fc005627c9171e714730f0278b4b9a495f36c65fdda19c611","libgit2/src/transports/ssh.c":"0d34b00e202947401015956d9f2f8bdeaa6c4f1d3b103d75d9cb07be422e6551","libgit2/src/transports/ssh.h":"a4f6279848362d54f6ba4e9338443d6a3402c1ddb9eb85e2e3befb937cbea2ff","libgit2/src/transports/winhttp.c":"209a96de0b4ae213f92a866f767807cdd81ee2bbef9296193de97729ebd38961","libgit2/src/tree-cache.c":"6a6851e406ae47fbfb132ed8b8c01e7566b6bc9b8fd6b1bd8d4c2ec83622ea74","libgit2/src/tree-cache.h":"f7fac0fe438958415ccd256e0bf9cbe30aa20aa125e60f3812a7fa0521ddb12a","libgit2/src/tree.c":"f470984b86f06dcf4ad55a3de1ecfb5f567fbdb68a0229119c88ef8f342c9a7d","libgit2/src/tree.h":"7f9d1e5262919c0758bab57a1459d18bb54ae138f97ac761884262c1e9dbd436","libgit2/src/tsort.c":"7ea74124c4b53afb2397578d197b1d460eff19e3e9b52964dcb8c606e705ef58","libgit2/src/unix/map.c":"92faca282b6d565dd498de4e045a01d1bda9632fbf436c224dcd036d97654715","libgit2/src/unix/posix.h":"5a1f217d988b9367e08d983e1669dfe56c3c41ad0c30e2e3968c79473175b54c","libgit2/src/unix/pthread.h":"58c92bef5ac49a7846c6ffdf0ae79996a2c6be965fce6fc2056fb5a5c1fdf512","libgit2/src/unix/realpath.c":"e3ed89d4139d62b8a8f37579edb1f262fa02972834603f7b00596cc88240ad2b","libgit2/src/userdiff.h":"fa4bb94fcee94ca85c3e8abcea9c46f2bba904fab11b44c724383911d762c344","libgit2/src/util.c":"56db29b49b21fad59a5af713ef5a371ba9df838da76f0fef05469378350b475b","libgit2/src/util.h":"20685af87004af12031dc60927b527032ff4aa2d1db64900b941ef9816e7a38c","libgit2/src/varint.c":"f93c5ba3498ac04d98ba13d3a320263892452356f797c4091411e5833dfe82f2","libgit2/src/varint.h":"db8ed46f6049f12058d4b624cb0a5ea9d0b0f1317b6378c8817d6e632b6436cd","libgit2/src/vector.c":"744e8f508fc2dfc8add5175e7154f793253a459cb7be6fc943ad5e10726dfe7b","libgit2/src/vector.h":"2ebdb354bbabae224773991a097d71fd14262af49eb2ab00a4ca3844ad54102f","libgit2/src/win32/dir.c":"c93de4aea5c0f5c57251e542b4d7ffd0fccac482532ed9bd11b4db14552225ee","libgit2/src/win32/dir.h":"8e520dd28e37c333aeb10f745efce8ba48a4db414b1605027787b1a52b75a222","libgit2/src/win32/error.c":"f1d2bcb2b6e60ca76c1ee0ca0f236e928331aa9755afc16926a5dab5de26d255","libgit2/src/win32/error.h":"47faa526d448f222c9ed0cf7c3f1ed2c4f14c166610524c76eeb6f0f83938a63","libgit2/src/win32/findfile.c":"17834ef067d58e357cae6936046c372dbd8aa866778c2bb600da7f3ebd52e3e6","libgit2/src/win32/findfile.h":"47842451768d01dec2b7965669ccbc9da6be26449e3b4ebf93caa1ff3f08ab3e","libgit2/src/win32/git2.rc":"fd75d8a9bcb7376d046aa85ae5dd17df18d5d654f635cbd42237a18033fd984d","libgit2/src/win32/map.c":"87812afcd711682018915214ff2220bdfe1f44a18a78a56b19afeeaa45bdcbf8","libgit2/src/win32/mingw-compat.h":"f7b0c7e9dd7147e8930782cdf54ce4be385172966dd1e27435446f38cd2f6d68","libgit2/src/win32/msvc-compat.h":"e166a2d29a58b4634be612945c92878d88103653a2fa03d02fd5d39cbb74e96f","libgit2/src/win32/path_w32.c":"482b355132c32af1c3e0d1eb7978da43c01626ea9448765c424e25579120fb53","libgit2/src/win32/path_w32.h":"7c53c945c6019ad3fab956ab577e3d9eb37af9ce1e61c25d2fffde73ae6a0158","libgit2/src/win32/posix.h":"3699b39d8fdb378de0effc0894d65cf6fe88f04a4cf4c66919246d59618081cf","libgit2/src/win32/posix_w32.c":"036d07e52ddf4c46ffdb7a1008fb1ca363174d78e5fec9156e2bd6a8d227ae92","libgit2/src/win32/precompiled.c":"4dff04101bd64b95c8f708d1accd1bedc39e95a263444290f796c63f4734d4cd","libgit2/src/win32/precompiled.h":"cc87a24892f8a0d90c6633cf66a9f88350e184088b4bafb4afa6c5e26ed40910","libgit2/src/win32/reparse.h":"b0633542864a263dd0a14b260c400a07933fda30fe8619d323a5e97a65d07a26","libgit2/src/win32/thread.c":"115e263bd4492b0a79aeda38d7e0972ec20a97eaccc179226cc124d1af0ac4c5","libgit2/src/win32/thread.h":"cebaa0ed2045a4fa1d4a910db988639e02665b8b299c74454cbcb79de45d02f2","libgit2/src/win32/utf-conv.c":"fce8f7998d93fcd4f043d4d643f466a854b9611389487250e65fbc987a455bca","libgit2/src/win32/utf-conv.h":"46473448949ef66faf32be710f48d3a925e3db1aee27c4cfc4fcd36d344a5404","libgit2/src/win32/version.h":"d9d9546728ee78923ba7ea1c16c000d44450ca80f8c0c3268bf58fa9966ba38f","libgit2/src/win32/w32_buffer.c":"8b2b138049d324b195ca544e57e584ac1c7d32bfa4a0b7db8dcb7a9d15d6e6b4","libgit2/src/win32/w32_buffer.h":"f50a4d06e54710e5f0c5a3eca13690d71875339ae7e696455062651e265b6ae5","libgit2/src/win32/w32_crtdbg_stacktrace.c":"c7eed5d36b4cb74cad7ee4b7982b5d50741ba8f0eed12955d4baef4147f33419","libgit2/src/win32/w32_crtdbg_stacktrace.h":"9260b486e1b6db9c6002207e267dfe56fb7e48ad8f7662df99dc01fd267572a6","libgit2/src/win32/w32_stack.c":"1bb366fcdce5d0ef14d6de6632465e8916e6c1c6f854f2087fc80405113a6032","libgit2/src/win32/w32_stack.h":"30ce8d5555d3c32ef9578f130eacbeff96b803288a92b82f970a7e13dbefd8a1","libgit2/src/win32/w32_util.c":"8a578b6f96d0f9d18bf1157b8d9d0b7daa4c4c537bb1df0bb56906dbd72650b2","libgit2/src/win32/w32_util.h":"ef7088ebacc639453de70bf4387114292a808c184206076bf5686fc91e151c1e","libgit2/src/win32/win32-compat.h":"5ea7b1837a159d66a89365ee2bf3724b32579a6a78d94b0b205d44c8697a8e6f","libgit2/src/worktree.c":"0ae754ae6aca0cf4eb5825c3dec23a54caaf3bdd59129e3fef86bd5a0356c135","libgit2/src/worktree.h":"8f2e10b231590962e1d43b4dd51085da343f09f3e74245141720de9ff8a8e4c5","libgit2/src/xdiff/xdiff.h":"63fb0e162716c6c30364d24f5be1192a3724e527864e462d2163a904222d0b91","libgit2/src/xdiff/xdiffi.c":"b5a12f736e0f65f406b9fdeea09c8c8b4ffc55e17ae93f7795e0d68158c704f9","libgit2/src/xdiff/xdiffi.h":"3429a12de1a8c990005268801706fc2ced0f935813e12493c2dee68ba28dc94e","libgit2/src/xdiff/xemit.c":"588f9867c656b7311006e63ac1c1fc57cfd5f1f2ba5890bc60946d9f638afcb7","libgit2/src/xdiff/xemit.h":"0a8c569eec74bb4d6e8b7b9a50b457532550800e0566cbba6d185974613a2e6c","libgit2/src/xdiff/xhistogram.c":"b829a7ba21d3c0c3c269a9ed33f32acdefc634ce471a72c622118483833dde11","libgit2/src/xdiff/xinclude.h":"26f9a54fefdc2635e31801febb7d44afa8d039d078414d6cd26463e67e5346b5","libgit2/src/xdiff/xmacros.h":"d9cc54bfc6c0f9e6eef68f9d03594a8bd10f6243a2137776527bb5c849cc9de2","libgit2/src/xdiff/xmerge.c":"6bf411d9046a54362004bae83408aaefa639c8fbb03eb1dff96c8da4df8217ba","libgit2/src/xdiff/xpatience.c":"9a8158556fddb9432e213f189c7c9c6426003f56dccf9e7f5e494ec5f800a345","libgit2/src/xdiff/xprepare.c":"a99e59dfd2adff23a5f3f2b3920ee384eb6665cfbc40eddde11b87dfb0c51bc7","libgit2/src/xdiff/xprepare.h":"4945e8fffe620cd4d687c12618d1a4b2aa95a7a8097abf3e5e341abf96c76e1b","libgit2/src/xdiff/xtypes.h":"3336d046bf60e0dc99f3686dfe9ecf098456f0aebe96486be5d1cd64b5d9cefa","libgit2/src/xdiff/xutils.c":"6928247d6adee0f64a63c6ba103a47abe3a83dca12577552d23094f53d4a55f7","libgit2/src/xdiff/xutils.h":"78e2813f0d604d4deaf29583f6709111d8368b4bbd71cfdc55d56769570abe3e","libgit2/src/zstream.c":"7ef827974fd3a039b0b5f38d869768d70017eb3290c9c624f3f17f79dfa968bd","libgit2/src/zstream.h":"b5037f14aefdf2d75a3079850a8077717a6a648821950eded8ee2f980abcdcf8"},"package":"48441cb35dc255da8ae72825689a95368bf510659ae1ad55dc4aa88cb1789bf1"}
\ No newline at end of file

vendor/libgit2-sys/Cargo.toml

diff --git a/vendor/libgit2-sys/Cargo.toml b/vendor/libgit2-sys/Cargo.toml
new file mode 100644
index 0000000..9173e65
--- /dev/null
+++ b/vendor/libgit2-sys/Cargo.toml
@@ -0,0 +1,53 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g. crates.io) dependencies
+#
+# If you believe there's an error in this file please file an
+# issue against the rust-lang/cargo repository. If you're
+# editing this file be aware that the upstream Cargo.toml
+# will likely look very different (and much more reasonable)
+
+[package]
+name = "libgit2-sys"
+version = "0.7.11"
+authors = ["Alex Crichton <alex@alexcrichton.com>"]
+build = "build.rs"
+links = "git2"
+exclude = ["libgit2/tests/*"]
+description = "Native bindings to the libgit2 library"
+license = "MIT/Apache-2.0"
+repository = "https://github.com/alexcrichton/git2-rs"
+
+[lib]
+name = "libgit2_sys"
+path = "lib.rs"
+[dependencies.curl-sys]
+version = "0.4.10"
+optional = true
+
+[dependencies.libc]
+version = "0.2"
+
+[dependencies.libssh2-sys]
+version = "0.2.11"
+optional = true
+
+[dependencies.libz-sys]
+version = "1.0.22"
+[build-dependencies.cc]
+version = "1.0.25"
+
+[build-dependencies.pkg-config]
+version = "0.3"
+
+[features]
+curl = ["curl-sys"]
+https = ["openssl-sys"]
+ssh = ["libssh2-sys"]
+ssh_key_from_memory = []
+[target."cfg(unix)".dependencies.openssl-sys]
+version = "0.9"
+optional = true

vendor/libgit2-sys/LICENSE-APACHE

diff --git a/vendor/libgit2-sys/LICENSE-APACHE b/vendor/libgit2-sys/LICENSE-APACHE
new file mode 100644
index 0000000..16fe87b
--- /dev/null
+++ b/vendor/libgit2-sys/LICENSE-APACHE
@@ -0,0 +1,201 @@
+                              Apache License
+                        Version 2.0, January 2004
+                     http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+1. Definitions.
+
+   "License" shall mean the terms and conditions for use, reproduction,
+   and distribution as defined by Sections 1 through 9 of this document.
+
+   "Licensor" shall mean the copyright owner or entity authorized by
+   the copyright owner that is granting the License.
+
+   "Legal Entity" shall mean the union of the acting entity and all
+   other entities that control, are controlled by, or are under common
+   control with that entity. For the purposes of this definition,
+   "control" means (i) the power, direct or indirect, to cause the
+   direction or management of such entity, whether by contract or
+   otherwise, or (ii) ownership of fifty percent (50%) or more of the
+   outstanding shares, or (iii) beneficial ownership of such entity.
+
+   "You" (or "Your") shall mean an individual or Legal Entity
+   exercising permissions granted by this License.
+
+   "Source" form shall mean the preferred form for making modifications,
+   including but not limited to software source code, documentation
+   source, and configuration files.
+
+   "Object" form shall mean any form resulting from mechanical
+   transformation or translation of a Source form, including but
+   not limited to compiled object code, generated documentation,
+   and conversions to other media types.
+
+   "Work" shall mean the work of authorship, whether in Source or
+   Object form, made available under the License, as indicated by a
+   copyright notice that is included in or attached to the work
+   (an example is provided in the Appendix below).
+
+   "Derivative Works" shall mean any work, whether in Source or Object
+   form, that is based on (or derived from) the Work and for which the
+   editorial revisions, annotations, elaborations, or other modifications
+   represent, as a whole, an original work of authorship. For the purposes
+   of this License, Derivative Works shall not include works that remain
+   separable from, or merely link (or bind by name) to the interfaces of,
+   the Work and Derivative Works thereof.
+
+   "Contribution" shall mean any work of authorship, including
+   the original version of the Work and any modifications or additions
+   to that Work or Derivative Works thereof, that is intentionally
+   submitted to Licensor for inclusion in the Work by the copyright owner
+   or by an individual or Legal Entity authorized to submit on behalf of
+   the copyright owner. For the purposes of this definition, "submitted"
+   means any form of electronic, verbal, or written communication sent
+   to the Licensor or its representatives, including but not limited to
+   communication on electronic mailing lists, source code control systems,
+   and issue tracking systems that are managed by, or on behalf of, the
+   Licensor for the purpose of discussing and improving the Work, but
+   excluding communication that is conspicuously marked or otherwise
+   designated in writing by the copyright owner as "Not a Contribution."
+
+   "Contributor" shall mean Licensor and any individual or Legal Entity
+   on behalf of whom a Contribution has been received by Licensor and
+   subsequently incorporated within the Work.
+
+2. Grant of Copyright License. Subject to the terms and conditions of
+   this License, each Contributor hereby grants to You a perpetual,
+   worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+   copyright license to reproduce, prepare Derivative Works of,
+   publicly display, publicly perform, sublicense, and distribute the
+   Work and such Derivative Works in Source or Object form.
+
+3. Grant of Patent License. Subject to the terms and conditions of
+   this License, each Contributor hereby grants to You a perpetual,
+   worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+   (except as stated in this section) patent license to make, have made,
+   use, offer to sell, sell, import, and otherwise transfer the Work,
+   where such license applies only to those patent claims licensable
+   by such Contributor that are necessarily infringed by their
+   Contribution(s) alone or by combination of their Contribution(s)
+   with the Work to which such Contribution(s) was submitted. If You
+   institute patent litigation against any entity (including a
+   cross-claim or counterclaim in a lawsuit) alleging that the Work
+   or a Contribution incorporated within the Work constitutes direct
+   or contributory patent infringement, then any patent licenses
+   granted to You under this License for that Work shall terminate
+   as of the date such litigation is filed.
+
+4. Redistribution. You may reproduce and distribute copies of the
+   Work or Derivative Works thereof in any medium, with or without
+   modifications, and in Source or Object form, provided that You
+   meet the following conditions:
+
+   (a) You must give any other recipients of the Work or
+       Derivative Works a copy of this License; and
+
+   (b) You must cause any modified files to carry prominent notices
+       stating that You changed the files; and
+
+   (c) You must retain, in the Source form of any Derivative Works
+       that You distribute, all copyright, patent, trademark, and
+       attribution notices from the Source form of the Work,
+       excluding those notices that do not pertain to any part of
+       the Derivative Works; and
+
+   (d) If the Work includes a "NOTICE" text file as part of its
+       distribution, then any Derivative Works that You distribute must
+       include a readable copy of the attribution notices contained
+       within such NOTICE file, excluding those notices that do not
+       pertain to any part of the Derivative Works, in at least one
+       of the following places: within a NOTICE text file distributed
+       as part of the Derivative Works; within the Source form or
+       documentation, if provided along with the Derivative Works; or,
+       within a display generated by the Derivative Works, if and
+       wherever such third-party notices normally appear. The contents
+       of the NOTICE file are for informational purposes only and
+       do not modify the License. You may add Your own attribution
+       notices within Derivative Works that You distribute, alongside
+       or as an addendum to the NOTICE text from the Work, provided
+       that such additional attribution notices cannot be construed
+       as modifying the License.
+
+   You may add Your own copyright statement to Your modifications and
+   may provide additional or different license terms and conditions
+   for use, reproduction, or distribution of Your modifications, or
+   for any such Derivative Works as a whole, provided Your use,
+   reproduction, and distribution of the Work otherwise complies with
+   the conditions stated in this License.
+
+5. Submission of Contributions. Unless You explicitly state otherwise,
+   any Contribution intentionally submitted for inclusion in the Work
+   by You to the Licensor shall be under the terms and conditions of
+   this License, without any additional terms or conditions.
+   Notwithstanding the above, nothing herein shall supersede or modify
+   the terms of any separate license agreement you may have executed
+   with Licensor regarding such Contributions.
+
+6. Trademarks. This License does not grant permission to use the trade
+   names, trademarks, service marks, or product names of the Licensor,
+   except as required for reasonable and customary use in describing the
+   origin of the Work and reproducing the content of the NOTICE file.
+
+7. Disclaimer of Warranty. Unless required by applicable law or
+   agreed to in writing, Licensor provides the Work (and each
+   Contributor provides its Contributions) on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+   implied, including, without limitation, any warranties or conditions
+   of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+   PARTICULAR PURPOSE. You are solely responsible for determining the
+   appropriateness of using or redistributing the Work and assume any
+   risks associated with Your exercise of permissions under this License.
+
+8. Limitation of Liability. In no event and under no legal theory,
+   whether in tort (including negligence), contract, or otherwise,
+   unless required by applicable law (such as deliberate and grossly
+   negligent acts) or agreed to in writing, shall any Contributor be
+   liable to You for damages, including any direct, indirect, special,
+   incidental, or consequential damages of any character arising as a
+   result of this License or out of the use or inability to use the
+   Work (including but not limited to damages for loss of goodwill,
+   work stoppage, computer failure or malfunction, or any and all
+   other commercial damages or losses), even if such Contributor
+   has been advised of the possibility of such damages.
+
+9. Accepting Warranty or Additional Liability. While redistributing
+   the Work or Derivative Works thereof, You may choose to offer,
+   and charge a fee for, acceptance of support, warranty, indemnity,
+   or other liability obligations and/or rights consistent with this
+   License. However, in accepting such obligations, You may act only
+   on Your own behalf and on Your sole responsibility, not on behalf
+   of any other Contributor, and only if You agree to indemnify,
+   defend, and hold each Contributor harmless for any liability
+   incurred by, or claims asserted against, such Contributor by reason
+   of your accepting any such warranty or additional liability.
+
+END OF TERMS AND CONDITIONS
+
+APPENDIX: How to apply the Apache License to your work.
+
+   To apply the Apache License to your work, attach the following
+   boilerplate notice, with the fields enclosed by brackets "[]"
+   replaced with your own identifying information. (Don't include
+   the brackets!)  The text should be enclosed in the appropriate
+   comment syntax for the file format. We also recommend that a
+   file or class name and description of purpose be included on the
+   same "printed page" as the copyright notice for easier
+   identification within third-party archives.
+
+Copyright [yyyy] [name of copyright owner]
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.

vendor/libgit2-sys/LICENSE-MIT

diff --git a/vendor/libgit2-sys/LICENSE-MIT b/vendor/libgit2-sys/LICENSE-MIT
new file mode 100644
index 0000000..39e0ed6
--- /dev/null
+++ b/vendor/libgit2-sys/LICENSE-MIT
@@ -0,0 +1,25 @@
+Copyright (c) 2014 Alex Crichton
+
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

vendor/libgit2-sys/build.rs

diff --git a/vendor/libgit2-sys/build.rs b/vendor/libgit2-sys/build.rs
new file mode 100644
index 0000000..20806c7
--- /dev/null
+++ b/vendor/libgit2-sys/build.rs
@@ -0,0 +1,194 @@
+extern crate cc;
+extern crate pkg_config;
+
+use std::env;
+use std::fs;
+use std::path::{Path, PathBuf};
+use std::process::Command;
+
+fn main() {
+    let https = env::var("CARGO_FEATURE_HTTPS").is_ok();
+    let ssh = env::var("CARGO_FEATURE_SSH").is_ok();
+    let curl = env::var("CARGO_FEATURE_CURL").is_ok();
+
+    if env::var("LIBGIT2_SYS_USE_PKG_CONFIG").is_ok() {
+        if pkg_config::find_library("libgit2").is_ok() {
+            return
+        }
+    }
+
+    if !Path::new("libgit2/.git").exists() {
+        let _ = Command::new("git").args(&["submodule", "update", "--init"])
+                                   .status();
+    }
+
+    let target = env::var("TARGET").unwrap();
+    let windows = target.contains("windows");
+    let dst = PathBuf::from(env::var_os("OUT_DIR").unwrap());
+    let include = dst.join("include");
+    let mut cfg = cc::Build::new();
+    fs::create_dir_all(&include).unwrap();
+
+    // Copy over all header files
+    cp_r("libgit2/include".as_ref(), &include);
+
+    cfg.include(&include)
+        .include("libgit2/src")
+        .out_dir(dst.join("build"))
+        .warnings(false);
+
+    // Include all cross-platform C files
+    add_c_files(&mut cfg, "libgit2/src".as_ref());
+    add_c_files(&mut cfg, "libgit2/src/xdiff".as_ref());
+
+    // These are activated by feautres, but they're all unconditionally always
+    // compiled apparently and have internal #define's to make sure they're
+    // compiled correctly.
+    add_c_files(&mut cfg, "libgit2/src/transports".as_ref());
+    add_c_files(&mut cfg, "libgit2/src/streams".as_ref());
+
+    // Always use bundled http-parser for now
+    cfg.include("libgit2/deps/http-parser")
+        .file("libgit2/deps/http-parser/http_parser.c");
+
+    // Always use bundled regex for now
+    cfg.include("libgit2/deps/regex")
+        .file("libgit2/deps/regex/regex.c");
+
+    if windows {
+        add_c_files(&mut cfg, "libgit2/src/win32".as_ref());
+        cfg.define("STRSAFE_NO_DEPRECATE", None);
+
+        // libgit2's build system claims that forks like mingw-w64 of MinGW
+        // still want this define to use C99 stdio functions automatically.
+        // Apparently libgit2 breaks at runtime if this isn't here? Who knows!
+        if target.contains("gnu") {
+            cfg.define("__USE_MINGW_ANSI_STDIO", "1");
+        }
+    } else {
+        add_c_files(&mut cfg, "libgit2/src/unix".as_ref());
+        cfg.flag("-fvisibility=hidden");
+    }
+    if target.contains("solaris") {
+        cfg.define("_POSIX_C_SOURCE", "200112L");
+        cfg.define("__EXTENSIONS__", None);
+    }
+
+    let mut features = String::new();
+
+    features.push_str("#ifndef INCLUDE_features_h\n");
+    features.push_str("#define INCLUDE_features_h\n");
+    features.push_str("#define GIT_THREADS 1\n");
+
+    if !target.contains("android") {
+        features.push_str("#define GIT_USE_NSEC 1\n");
+    }
+
+    if target.contains("apple") {
+        features.push_str("#define GIT_USE_STAT_MTIMESPEC 1\n");
+    } else {
+        features.push_str("#define GIT_USE_STAT_MTIM 1\n");
+    }
+
+    if env::var("CARGO_CFG_TARGET_POINTER_WIDTH").unwrap() == "32" {
+        features.push_str("#define GIT_ARCH_32 1\n");
+    } else {
+        features.push_str("#define GIT_ARCH_64 1\n");
+    }
+
+    if ssh {
+        if let Some(path) = env::var_os("DEP_SSH2_INCLUDE") {
+            cfg.include(path);
+        }
+        features.push_str("#define GIT_SSH 1\n");
+        features.push_str("#define GIT_SSH_MEMORY_CREDENTIALS 1\n");
+    }
+    if https {
+        features.push_str("#define GIT_HTTPS 1\n");
+
+        if windows {
+            features.push_str("#define GIT_WINHTTP 1\n");
+            features.push_str("#define GIT_SHA1_WIN32 1\n");
+            cfg.file("libgit2/src/hash/hash_win32.c");
+        } else if target.contains("apple") {
+            features.push_str("#define GIT_SECURE_TRANSPORT 1\n");
+            features.push_str("#define GIT_SHA1_COMMON_CRYPTO 1\n");
+        } else {
+            features.push_str("#define GIT_OPENSSL 1\n");
+            features.push_str("#define GIT_SHA1_OPENSSL 1\n");
+            if let Some(path) = env::var_os("DEP_OPENSSL_INCLUDE") {
+                cfg.include(path);
+            }
+        }
+    } else {
+        cfg.file("libgit2/src/hash/hash_generic.c");
+    }
+
+    if curl {
+        features.push_str("#define GIT_CURL 1\n");
+        if let Some(path) = env::var_os("DEP_CURL_INCLUDE") {
+            cfg.include(path);
+        }
+        // Handle dllimport/dllexport on windows by making sure that if we built
+        // curl statically (as told to us by the `curl-sys` crate) we define the
+        // correct values for curl's header files.
+        if env::var_os("DEP_CURL_STATIC").is_some() {
+            cfg.define("CURL_STATICLIB", None);
+        }
+    }
+    if let Some(path) = env::var_os("DEP_Z_INCLUDE") {
+        cfg.include(path);
+    }
+
+    if target.contains("apple") {
+        features.push_str("#define GIT_USE_ICONV 1\n");
+    }
+
+    features.push_str("#endif\n");
+    fs::write(include.join("git2/sys/features.h"), features).unwrap();
+
+    cfg.compile("git2");
+
+    println!("cargo:root={}", dst.display());
+
+    if target.contains("windows") {
+        println!("cargo:rustc-link-lib=winhttp");
+        println!("cargo:rustc-link-lib=rpcrt4");
+        println!("cargo:rustc-link-lib=ole32");
+        println!("cargo:rustc-link-lib=crypt32");
+        return
+    }
+
+    if target.contains("apple") {
+        println!("cargo:rustc-link-lib=iconv");
+        println!("cargo:rustc-link-lib=framework=Security");
+        println!("cargo:rustc-link-lib=framework=CoreFoundation");
+    }
+}
+
+fn cp_r(from: &Path, to: &Path) {
+    for e in from.read_dir().unwrap() {
+        let e = e.unwrap();
+        let from = e.path();
+        let to = to.join(e.file_name());
+        if e.file_type().unwrap().is_dir() {
+            fs::create_dir_all(&to).unwrap();
+            cp_r(&from, &to);
+        } else {
+            println!("{} => {}", from.display(), to.display());
+            fs::copy(&from, &to).unwrap();
+        }
+    }
+}
+
+fn add_c_files(build: &mut cc::Build, path: &Path) {
+    for e in path.read_dir().unwrap() {
+        let e = e.unwrap();
+        let path = e.path();
+        if e.file_type().unwrap().is_dir() {
+            // skip dirs for now
+        } else if path.extension().and_then(|s| s.to_str()) == Some("c") {
+            build.file(&path);
+        }
+    }
+}

vendor/libgit2-sys/lib.rs

diff --git a/vendor/libgit2-sys/lib.rs b/vendor/libgit2-sys/lib.rs
new file mode 100644
index 0000000..7bede4e
--- /dev/null
+++ b/vendor/libgit2-sys/lib.rs
@@ -0,0 +1,3052 @@
+#![doc(html_root_url = "http://alexcrichton.com/git2-rs")]
+#![allow(non_camel_case_types, unused_extern_crates)]
+
+extern crate libc;
+#[cfg(feature = "ssh")]
+extern crate libssh2_sys as libssh2;
+#[cfg(feature = "curl")]
+extern crate curl_sys;
+#[cfg(all(unix, feature = "https"))]
+extern crate openssl_sys;
+extern crate libz_sys as libz;
+
+use libc::{c_int, c_char, c_uint, size_t, c_uchar, c_void};
+
+pub const GIT_OID_RAWSZ: usize = 20;
+pub const GIT_OID_HEXSZ: usize = GIT_OID_RAWSZ * 2;
+pub const GIT_CLONE_OPTIONS_VERSION: c_uint = 1;
+pub const GIT_STASH_APPLY_OPTIONS_VERSION: c_uint = 1;
+pub const GIT_CHECKOUT_OPTIONS_VERSION: c_uint = 1;
+pub const GIT_MERGE_OPTIONS_VERSION: c_uint = 1;
+pub const GIT_REMOTE_CALLBACKS_VERSION: c_uint = 1;
+pub const GIT_STATUS_OPTIONS_VERSION: c_uint = 1;
+pub const GIT_BLAME_OPTIONS_VERSION: c_uint = 1;
+pub const GIT_PROXY_OPTIONS_VERSION: c_uint = 1;
+pub const GIT_SUBMODULE_UPDATE_OPTIONS_VERSION: c_uint = 1;
+pub const GIT_ODB_BACKEND_VERSION: c_uint = 1;
+pub const GIT_REFDB_BACKEND_VERSION: c_uint = 1;
+
+macro_rules! git_enum {
+    (pub enum $name:ident { $($variants:tt)* }) => {
+        #[cfg(target_env = "msvc")]
+        pub type $name = i32;
+        #[cfg(not(target_env = "msvc"))]
+        pub type $name = u32;
+        git_enum!(gen, $name, 0, $($variants)*);
+    };
+    (pub enum $name:ident: $t:ty { $($variants:tt)* }) => {
+        pub type $name = $t;
+        git_enum!(gen, $name, 0, $($variants)*);
+    };
+    (gen, $name:ident, $val:expr, $variant:ident, $($rest:tt)*) => {
+        pub const $variant: $name = $val;
+        git_enum!(gen, $name, $val+1, $($rest)*);
+    };
+    (gen, $name:ident, $val:expr, $variant:ident = $e:expr, $($rest:tt)*) => {
+        pub const $variant: $name = $e;
+        git_enum!(gen, $name, $e+1, $($rest)*);
+    };
+    (gen, $name:ident, $val:expr, ) => {}
+}
+
+pub enum git_blob {}
+pub enum git_branch_iterator {}
+pub enum git_blame {}
+pub enum git_commit {}
+pub enum git_config {}
+pub enum git_config_iterator {}
+pub enum git_index {}
+pub enum git_object {}
+pub enum git_reference {}
+pub enum git_reference_iterator {}
+pub enum git_annotated_commit {}
+pub enum git_refdb {}
+pub enum git_refspec {}
+pub enum git_remote {}
+pub enum git_repository {}
+pub enum git_revwalk {}
+pub enum git_submodule {}
+pub enum git_tag {}
+pub enum git_tree {}
+pub enum git_tree_entry {}
+pub enum git_treebuilder {}
+pub enum git_push {}
+pub enum git_note {}
+pub enum git_note_iterator {}
+pub enum git_status_list {}
+pub enum git_pathspec {}
+pub enum git_pathspec_match_list {}
+pub enum git_diff {}
+pub enum git_diff_stats {}
+pub enum git_patch {}
+pub enum git_rebase {}
+pub enum git_reflog {}
+pub enum git_reflog_entry {}
+pub enum git_describe_result {}
+pub enum git_packbuilder {}
+pub enum git_odb {}
+pub enum git_odb_stream {}
+pub enum git_odb_object {}
+pub enum git_odb_writepack {}
+pub enum git_worktree {}
+
+#[repr(C)]
+pub struct git_revspec {
+    pub from: *mut git_object,
+    pub to: *mut git_object,
+    pub flags: c_uint,
+}
+
+#[repr(C)]
+pub struct git_error {
+    pub message: *mut c_char,
+    pub klass: c_int,
+}
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct git_oid {
+    pub id: [u8; GIT_OID_RAWSZ],
+}
+
+#[repr(C)]
+#[derive(Copy)]
+pub struct git_strarray {
+    pub strings: *mut *mut c_char,
+    pub count: size_t,
+}
+impl Clone for git_strarray {
+    fn clone(&self) -> git_strarray { *self }
+}
+
+#[repr(C)]
+#[derive(Copy)]
+pub struct git_oidarray {
+    pub ids: *mut git_oid,
+    pub count: size_t,
+}
+impl Clone for git_oidarray {
+    fn clone(&self) -> git_oidarray { *self }
+}
+
+#[repr(C)]
+pub struct git_signature {
+    pub name: *mut c_char,
+    pub email: *mut c_char,
+    pub when: git_time,
+}
+
+#[repr(C)]
+#[derive(Copy, Clone, Eq, PartialEq)]
+pub struct git_time {
+    pub time: git_time_t,
+    pub offset: c_int,
+    pub sign: c_char,
+}
+
+pub type git_off_t = i64;
+pub type git_time_t = i64;
+
+git_enum! {
+    pub enum git_revparse_mode_t {
+        GIT_REVPARSE_SINGLE = 1 << 0,
+        GIT_REVPARSE_RANGE = 1 << 1,
+        GIT_REVPARSE_MERGE_BASE = 1 << 2,
+    }
+}
+
+git_enum! {
+    pub enum git_error_code: c_int {
+        GIT_OK = 0,
+
+        GIT_ERROR = -1,
+        GIT_ENOTFOUND = -3,
+        GIT_EEXISTS = -4,
+        GIT_EAMBIGUOUS = -5,
+        GIT_EBUFS = -6,
+        GIT_EUSER = -7,
+        GIT_EBAREREPO = -8,
+        GIT_EUNBORNBRANCH = -9,
+        GIT_EUNMERGED = -10,
+        GIT_ENONFASTFORWARD = -11,
+        GIT_EINVALIDSPEC = -12,
+        GIT_ECONFLICT = -13,
+        GIT_ELOCKED = -14,
+        GIT_EMODIFIED = -15,
+        GIT_EAUTH = -16,
+        GIT_ECERTIFICATE = -17,
+        GIT_EAPPLIED = -18,
+        GIT_EPEEL = -19,
+        GIT_EEOF = -20,
+        GIT_EINVALID = -21,
+        GIT_EUNCOMMITTED = -22,
+        GIT_EDIRECTORY = -23,
+        GIT_EMERGECONFLICT = -24,
+        GIT_PASSTHROUGH = -30,
+        GIT_ITEROVER = -31,
+    }
+}
+
+git_enum! {
+    pub enum git_error_t {
+        GITERR_NONE = 0,
+        GITERR_NOMEMORY,
+        GITERR_OS,
+        GITERR_INVALID,
+        GITERR_REFERENCE,
+        GITERR_ZLIB,
+        GITERR_REPOSITORY,
+        GITERR_CONFIG,
+        GITERR_REGEX,
+        GITERR_ODB,
+        GITERR_INDEX,
+        GITERR_OBJECT,
+        GITERR_NET,
+        GITERR_TAG,
+        GITERR_TREE,
+        GITERR_INDEXER,
+        GITERR_SSL,
+        GITERR_SUBMODULE,
+        GITERR_THREAD,
+        GITERR_STASH,
+        GITERR_CHECKOUT,
+        GITERR_FETCHHEAD,
+        GITERR_MERGE,
+        GITERR_SSH,
+        GITERR_FILTER,
+        GITERR_REVERT,
+        GITERR_CALLBACK,
+        GITERR_CHERRYPICK,
+        GITERR_DESCRIBE,
+        GITERR_REBASE,
+        GITERR_FILESYSTEM,
+    }
+}
+
+git_enum! {
+    pub enum git_repository_state_t {
+        GIT_REPOSITORY_STATE_NONE,
+        GIT_REPOSITORY_STATE_MERGE,
+        GIT_REPOSITORY_STATE_REVERT,
+        GIT_REPOSITORY_STATE_REVERT_SEQUENCE,
+        GIT_REPOSITORY_STATE_CHERRYPICK,
+        GIT_REPOSITORY_STATE_CHERRYPICK_SEQUENCE,
+        GIT_REPOSITORY_STATE_BISECT,
+        GIT_REPOSITORY_STATE_REBASE,
+        GIT_REPOSITORY_STATE_REBASE_INTERACTIVE,
+        GIT_REPOSITORY_STATE_REBASE_MERGE,
+        GIT_REPOSITORY_STATE_APPLY_MAILBOX,
+        GIT_REPOSITORY_STATE_APPLY_MAILBOX_OR_REBASE,
+    }
+}
+
+git_enum! {
+    pub enum git_direction {
+        GIT_DIRECTION_FETCH,
+        GIT_DIRECTION_PUSH,
+    }
+}
+
+#[repr(C)]
+pub struct git_clone_options {
+    pub version: c_uint,
+    pub checkout_opts: git_checkout_options,
+    pub fetch_opts: git_fetch_options,
+    pub bare: c_int,
+    pub local: git_clone_local_t,
+    pub checkout_branch: *const c_char,
+    pub repository_cb: Option<git_repository_create_cb>,
+    pub repository_cb_payload: *mut c_void,
+    pub remote_cb: Option<git_remote_create_cb>,
+    pub remote_cb_payload: *mut c_void,
+}
+
+git_enum! {
+    pub enum git_clone_local_t {
+        GIT_CLONE_LOCAL_AUTO,
+        GIT_CLONE_LOCAL,
+        GIT_CLONE_NO_LOCAL,
+        GIT_CLONE_LOCAL_NO_LINKS,
+    }
+}
+
+#[repr(C)]
+pub struct git_checkout_options {
+    pub version: c_uint,
+    pub checkout_strategy: c_uint,
+    pub disable_filters: c_int,
+    pub dir_mode: c_uint,
+    pub file_mode: c_uint,
+    pub file_open_flags: c_int,
+    pub notify_flags: c_uint,
+    pub notify_cb: Option<git_checkout_notify_cb>,
+    pub notify_payload: *mut c_void,
+    pub progress_cb: Option<git_checkout_progress_cb>,
+    pub progress_payload: *mut c_void,
+    pub paths: git_strarray,
+    pub baseline: *mut git_tree,
+    pub baseline_index: *mut git_index,
+    pub target_directory: *const c_char,
+    pub ancestor_label: *const c_char,
+    pub our_label: *const c_char,
+    pub their_label: *const c_char,
+    pub perfdata_cb: Option<git_checkout_perfdata_cb>,
+    pub perfdata_payload: *mut c_void,
+}
+
+pub type git_checkout_notify_cb = extern fn(git_checkout_notify_t,
+                                            *const c_char,
+                                            *const git_diff_file,
+                                            *const git_diff_file,
+                                            *const git_diff_file,
+                                            *mut c_void) -> c_int;
+pub type git_checkout_progress_cb = extern fn(*const c_char,
+                                              size_t,
+                                              size_t,
+                                              *mut c_void);
+
+pub type git_checkout_perfdata_cb = extern fn(*const git_checkout_perfdata,
+                                              *mut c_void);
+
+#[repr(C)]
+pub struct git_checkout_perfdata {
+    pub mkdir_calls: size_t,
+    pub stat_calls: size_t,
+    pub chmod_calls: size_t,
+}
+
+#[repr(C)]
+pub struct git_remote_callbacks {
+    pub version: c_uint,
+    pub sideband_progress: Option<git_transport_message_cb>,
+    pub completion: Option<extern fn(git_remote_completion_type,
+                                     *mut c_void) -> c_int>,
+    pub credentials: Option<git_cred_acquire_cb>,
+    pub certificate_check: Option<git_transport_certificate_check_cb>,
+    pub transfer_progress: Option<git_transfer_progress_cb>,
+    pub update_tips: Option<extern fn(*const c_char,
+                                      *const git_oid,
+                                      *const git_oid,
+                                      *mut c_void) -> c_int>,
+    pub pack_progress: Option<git_packbuilder_progress>,
+    pub push_transfer_progress: Option<git_push_transfer_progress>,
+    pub push_update_reference: Option<git_push_update_reference_cb>,
+    pub push_negotiation: Option<git_push_negotiation>,
+    pub transport: Option<git_transport_cb>,
+    pub payload: *mut c_void,
+}
+
+#[repr(C)]
+pub struct git_fetch_options {
+    pub version: c_int,
+    pub callbacks: git_remote_callbacks,
+    pub prune: git_fetch_prune_t,
+    pub update_fetchhead: c_int,
+    pub download_tags: git_remote_autotag_option_t,
+    pub proxy_opts: git_proxy_options,
+    pub custom_headers: git_strarray,
+}
+
+git_enum! {
+    pub enum git_remote_autotag_option_t {
+        GIT_REMOTE_DOWNLOAD_TAGS_UNSPECIFIED,
+        GIT_REMOTE_DOWNLOAD_TAGS_AUTO,
+        GIT_REMOTE_DOWNLOAD_TAGS_NONE,
+        GIT_REMOTE_DOWNLOAD_TAGS_ALL,
+    }
+}
+
+git_enum! {
+    pub enum git_fetch_prune_t {
+        GIT_FETCH_PRUNE_UNSPECIFIED,
+        GIT_FETCH_PRUNE,
+        GIT_FETCH_NO_PRUNE,
+    }
+}
+
+git_enum! {
+    pub enum git_remote_completion_type {
+        GIT_REMOTE_COMPLETION_DOWNLOAD,
+        GIT_REMOTE_COMPLETION_INDEXING,
+        GIT_REMOTE_COMPLETION_ERROR,
+    }
+}
+
+pub type git_transport_message_cb = extern fn(*const c_char, c_int,
+                                              *mut c_void) -> c_int;
+pub type git_cred_acquire_cb = extern fn(*mut *mut git_cred,
+                                         *const c_char, *const c_char,
+                                         c_uint, *mut c_void) -> c_int;
+pub type git_transfer_progress_cb = extern fn(*const git_transfer_progress,
+                                              *mut c_void) -> c_int;
+pub type git_packbuilder_progress = extern fn(git_packbuilder_stage_t, c_uint,
+                                              c_uint, *mut c_void) -> c_int;
+pub type git_push_transfer_progress = extern fn(c_uint, c_uint, size_t,
+                                                *mut c_void) -> c_int;
+pub type git_transport_certificate_check_cb = extern fn(*mut git_cert,
+                                                        c_int,
+                                                        *const c_char,
+                                                        *mut c_void) -> c_int;
+pub type git_push_negotiation = extern fn(*mut *const git_push_update,
+                                          size_t,
+                                          *mut c_void) -> c_int;
+
+pub type git_push_update_reference_cb = extern fn(*const c_char,
+                                                  *const c_char,
+                                                  *mut c_void) -> c_int;
+
+#[repr(C)]
+pub struct git_push_update {
+    pub src_refname: *mut c_char,
+    pub dst_refname: *mut c_char,
+    pub src: git_oid,
+    pub dst: git_oid,
+}
+
+git_enum! {
+    pub enum git_cert_t {
+        GIT_CERT_NONE,
+        GIT_CERT_X509,
+        GIT_CERT_HOSTKEY_LIBSSH2,
+    }
+}
+
+#[repr(C)]
+pub struct git_cert {
+    pub cert_type: git_cert_t,
+}
+
+#[repr(C)]
+pub struct git_cert_hostkey {
+    pub parent: git_cert,
+    pub kind: git_cert_ssh_t,
+    pub hash_md5: [u8; 16],
+    pub hash_sha1: [u8; 20],
+}
+
+#[repr(C)]
+pub struct git_cert_x509 {
+    pub parent: git_cert,
+    pub data: *mut c_void,
+    pub len: size_t,
+}
+
+git_enum! {
+    pub enum git_cert_ssh_t {
+        GIT_CERT_SSH_MD5 = 1 << 0,
+        GIT_CERT_SSH_SHA1 = 1 << 1,
+    }
+}
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct git_transfer_progress {
+    pub total_objects: c_uint,
+    pub indexed_objects: c_uint,
+    pub received_objects: c_uint,
+    pub local_objects: c_uint,
+    pub total_deltas: c_uint,
+    pub indexed_deltas: c_uint,
+    pub received_bytes: size_t,
+}
+
+#[repr(C)]
+pub struct git_diff_file {
+    pub id: git_oid,
+    pub path: *const c_char,
+    pub size: git_off_t,
+    pub flags: u32,
+    pub mode: u16,
+}
+
+pub type git_repository_create_cb = extern fn(*mut *mut git_repository,
+                                              *const c_char,
+                                              c_int, *mut c_void) -> c_int;
+pub type git_remote_create_cb = extern fn(*mut *mut git_remote,
+                                          *mut git_repository,
+                                          *const c_char,
+                                          *const c_char,
+                                          *mut c_void) -> c_int;
+
+git_enum! {
+    pub enum git_checkout_notify_t {
+        GIT_CHECKOUT_NOTIFY_NONE = 0,
+        GIT_CHECKOUT_NOTIFY_CONFLICT = (1 << 0),
+        GIT_CHECKOUT_NOTIFY_DIRTY = (1 << 1),
+        GIT_CHECKOUT_NOTIFY_UPDATED = (1 << 2),
+        GIT_CHECKOUT_NOTIFY_UNTRACKED = (1 << 3),
+        GIT_CHECKOUT_NOTIFY_IGNORED = (1 << 4),
+
+        GIT_CHECKOUT_NOTIFY_ALL = 0x0FFFF,
+    }
+}
+
+git_enum! {
+    pub enum git_status_t {
+        GIT_STATUS_CURRENT = 0,
+
+        GIT_STATUS_INDEX_NEW = (1 << 0),
+        GIT_STATUS_INDEX_MODIFIED = (1 << 1),
+        GIT_STATUS_INDEX_DELETED = (1 << 2),
+        GIT_STATUS_INDEX_RENAMED = (1 << 3),
+        GIT_STATUS_INDEX_TYPECHANGE = (1 << 4),
+
+        GIT_STATUS_WT_NEW = (1 << 7),
+        GIT_STATUS_WT_MODIFIED = (1 << 8),
+        GIT_STATUS_WT_DELETED = (1 << 9),
+        GIT_STATUS_WT_TYPECHANGE = (1 << 10),
+        GIT_STATUS_WT_RENAMED = (1 << 11),
+        GIT_STATUS_WT_UNREADABLE = (1 << 12),
+
+        GIT_STATUS_IGNORED = (1 << 14),
+        GIT_STATUS_CONFLICTED = (1 << 15),
+    }
+}
+
+git_enum! {
+    pub enum git_status_opt_t {
+        GIT_STATUS_OPT_INCLUDE_UNTRACKED                = (1 << 0),
+        GIT_STATUS_OPT_INCLUDE_IGNORED                  = (1 << 1),
+        GIT_STATUS_OPT_INCLUDE_UNMODIFIED               = (1 << 2),
+        GIT_STATUS_OPT_EXCLUDE_SUBMODULES               = (1 << 3),
+        GIT_STATUS_OPT_RECURSE_UNTRACKED_DIRS           = (1 << 4),
+        GIT_STATUS_OPT_DISABLE_PATHSPEC_MATCH           = (1 << 5),
+        GIT_STATUS_OPT_RECURSE_IGNORED_DIRS             = (1 << 6),
+        GIT_STATUS_OPT_RENAMES_HEAD_TO_INDEX            = (1 << 7),
+        GIT_STATUS_OPT_RENAMES_INDEX_TO_WORKDIR         = (1 << 8),
+        GIT_STATUS_OPT_SORT_CASE_SENSITIVELY            = (1 << 9),
+        GIT_STATUS_OPT_SORT_CASE_INSENSITIVELY          = (1 << 10),
+
+        GIT_STATUS_OPT_RENAMES_FROM_REWRITES            = (1 << 11),
+        GIT_STATUS_OPT_NO_REFRESH                       = (1 << 12),
+        GIT_STATUS_OPT_UPDATE_INDEX                     = (1 << 13),
+        GIT_STATUS_OPT_INCLUDE_UNREADABLE               = (1 << 14),
+        GIT_STATUS_OPT_INCLUDE_UNREADABLE_AS_UNTRACKED  = (1 << 15),
+    }
+}
+
+git_enum! {
+    pub enum git_status_show_t {
+        GIT_STATUS_SHOW_INDEX_AND_WORKDIR = 0,
+        GIT_STATUS_SHOW_INDEX_ONLY = 1,
+        GIT_STATUS_SHOW_WORKDIR_ONLY = 2,
+    }
+}
+
+git_enum! {
+    pub enum git_delta_t {
+        GIT_DELTA_UNMODIFIED,
+        GIT_DELTA_ADDED,
+        GIT_DELTA_DELETED,
+        GIT_DELTA_MODIFIED,
+        GIT_DELTA_RENAMED,
+        GIT_DELTA_COPIED,
+        GIT_DELTA_IGNORED,
+        GIT_DELTA_UNTRACKED,
+        GIT_DELTA_TYPECHANGE,
+        GIT_DELTA_UNREADABLE,
+        GIT_DELTA_CONFLICTED,
+    }
+}
+
+#[repr(C)]
+pub struct git_status_options {
+    pub version: c_uint,
+    pub show: git_status_show_t,
+    pub flags: c_uint,
+    pub pathspec: git_strarray,
+    pub baseline: *mut git_tree,
+}
+
+#[repr(C)]
+pub struct git_diff_delta {
+    pub status: git_delta_t,
+    pub flags: u32,
+    pub similarity: u16,
+    pub nfiles: u16,
+    pub old_file: git_diff_file,
+    pub new_file: git_diff_file,
+}
+
+#[repr(C)]
+pub struct git_status_entry {
+    pub status: git_status_t,
+    pub head_to_index: *mut git_diff_delta,
+    pub index_to_workdir: *mut git_diff_delta
+}
+
+git_enum! {
+    pub enum git_checkout_strategy_t {
+        GIT_CHECKOUT_NONE = 0,
+        GIT_CHECKOUT_SAFE = (1 << 0),
+        GIT_CHECKOUT_FORCE = (1 << 1),
+        GIT_CHECKOUT_RECREATE_MISSING = (1 << 2),
+        GIT_CHECKOUT_ALLOW_CONFLICTS = (1 << 4),
+        GIT_CHECKOUT_REMOVE_UNTRACKED = (1 << 5),
+        GIT_CHECKOUT_REMOVE_IGNORED = (1 << 6),
+        GIT_CHECKOUT_UPDATE_ONLY = (1 << 7),
+        GIT_CHECKOUT_DONT_UPDATE_INDEX = (1 << 8),
+        GIT_CHECKOUT_NO_REFRESH = (1 << 9),
+        GIT_CHECKOUT_SKIP_UNMERGED = (1 << 10),
+        GIT_CHECKOUT_USE_OURS = (1 << 11),
+        GIT_CHECKOUT_USE_THEIRS = (1 << 12),
+        GIT_CHECKOUT_DISABLE_PATHSPEC_MATCH = (1 << 13),
+        GIT_CHECKOUT_SKIP_LOCKED_DIRECTORIES = (1 << 18),
+        GIT_CHECKOUT_DONT_OVERWRITE_IGNORED = (1 << 19),
+        GIT_CHECKOUT_CONFLICT_STYLE_MERGE = (1 << 20),
+        GIT_CHECKOUT_CONFLICT_STYLE_DIFF3 = (1 << 21),
+
+        GIT_CHECKOUT_UPDATE_SUBMODULES = (1 << 16),
+        GIT_CHECKOUT_UPDATE_SUBMODULES_IF_CHANGED = (1 << 17),
+    }
+}
+
+git_enum! {
+    pub enum git_reset_t {
+        GIT_RESET_SOFT = 1,
+        GIT_RESET_MIXED = 2,
+        GIT_RESET_HARD = 3,
+    }
+}
+
+git_enum! {
+    pub enum git_otype: c_int {
+        GIT_OBJ_ANY = -2,
+        GIT_OBJ_BAD = -1,
+        GIT_OBJ__EXT1 = 0,
+        GIT_OBJ_COMMIT = 1,
+        GIT_OBJ_TREE = 2,
+        GIT_OBJ_BLOB = 3,
+        GIT_OBJ_TAG = 4,
+        GIT_OBJ__EXT2 = 5,
+        GIT_OBJ_OFS_DELTA = 6,
+        GIT_OBJ_REF_DELTA = 7,
+    }
+}
+
+git_enum! {
+    pub enum git_ref_t {
+        GIT_REF_INVALID = 0,
+        GIT_REF_OID = 1,
+        GIT_REF_SYMBOLIC = 2,
+        GIT_REF_LISTALL = GIT_REF_OID | GIT_REF_SYMBOLIC,
+    }
+}
+
+git_enum! {
+    pub enum git_filemode_t {
+        GIT_FILEMODE_UNREADABLE = 0o000000,
+        GIT_FILEMODE_TREE = 0o040000,
+        GIT_FILEMODE_BLOB = 0o100644,
+        GIT_FILEMODE_BLOB_EXECUTABLE = 0o100755,
+        GIT_FILEMODE_LINK = 0o120000,
+        GIT_FILEMODE_COMMIT = 0o160000,
+    }
+}
+
+git_enum! {
+    pub enum git_treewalk_mode {
+        GIT_TREEWALK_PRE = 0,
+        GIT_TREEWALK_POST = 1,
+    }
+}
+
+pub type git_treewalk_cb = extern fn(*const c_char, *const git_tree_entry,
+                                     *mut c_void) -> c_int;
+pub type git_treebuilder_filter_cb = extern fn(*const git_tree_entry,
+                                               *mut c_void) -> c_int;
+
+pub type git_revwalk_hide_cb = extern fn(*const git_oid, *mut c_void) -> c_int;
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct git_buf {
+    pub ptr: *mut c_char,
+    pub asize: size_t,
+    pub size: size_t,
+}
+
+git_enum! {
+    pub enum git_branch_t {
+        GIT_BRANCH_LOCAL = 1,
+        GIT_BRANCH_REMOTE = 2,
+        GIT_BRANCH_ALL = GIT_BRANCH_LOCAL | GIT_BRANCH_REMOTE,
+    }
+}
+
+pub const GIT_BLAME_NORMAL: u32 = 0;
+pub const GIT_BLAME_TRACK_COPIES_SAME_FILE: u32 = 1<<0;
+pub const GIT_BLAME_TRACK_COPIES_SAME_COMMIT_MOVES: u32 = 1<<1;
+pub const GIT_BLAME_TRACK_COPIES_SAME_COMMIT_COPIES: u32 = 1<<2;
+pub const GIT_BLAME_TRACK_COPIES_ANY_COMMIT_COPIES: u32 = 1<<3;
+pub const GIT_BLAME_FIRST_PARENT: u32 = 1<<4;
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct git_blame_options {
+    pub version: c_uint,
+
+    pub flags: u32,
+    pub min_match_characters: u16,
+    pub newest_commit: git_oid,
+    pub oldest_commit: git_oid,
+    pub min_line: usize,
+    pub max_line: usize,
+}
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct git_blame_hunk {
+    pub lines_in_hunk: usize,
+    pub final_commit_id: git_oid,
+    pub final_start_line_number: usize,
+    pub final_signature: *mut git_signature,
+    pub orig_commit_id: git_oid,
+    pub orig_path: *const c_char,
+    pub orig_start_line_number: usize,
+    pub orig_signature: *mut git_signature,
+    pub boundary: c_char,
+}
+
+pub type git_index_matched_path_cb = extern fn(*const c_char, *const c_char,
+                                               *mut c_void) -> c_int;
+
+git_enum! {
+    pub enum git_idxentry_extended_flag_t {
+        GIT_IDXENTRY_INTENT_TO_ADD     = 1 << 13,
+        GIT_IDXENTRY_SKIP_WORKTREE     = 1 << 14,
+        GIT_IDXENTRY_EXTENDED2         = 1 << 15,
+
+        GIT_IDXENTRY_UPDATE            = 1 << 0,
+        GIT_IDXENTRY_REMOVE            = 1 << 1,
+        GIT_IDXENTRY_UPTODATE          = 1 << 2,
+        GIT_IDXENTRY_ADDED             = 1 << 3,
+
+        GIT_IDXENTRY_HASHED            = 1 << 4,
+        GIT_IDXENTRY_UNHASHED          = 1 << 5,
+        GIT_IDXENTRY_WT_REMOVE         = 1 << 6,
+        GIT_IDXENTRY_CONFLICTED        = 1 << 7,
+
+        GIT_IDXENTRY_UNPACKED          = 1 << 8,
+        GIT_IDXENTRY_NEW_SKIP_WORKTREE = 1 << 9,
+    }
+}
+
+git_enum! {
+    pub enum git_indxentry_flag_t {
+        GIT_IDXENTRY_EXTENDED = 0x4000,
+        GIT_IDXENTRY_VALID    = 0x8000,
+    }
+}
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct git_index_entry {
+    pub ctime: git_index_time,
+    pub mtime: git_index_time,
+    pub dev: u32,
+    pub ino: u32,
+    pub mode: u32,
+    pub uid: u32,
+    pub gid: u32,
+    pub file_size: u32,
+    pub id: git_oid,
+    pub flags: u16,
+    pub flags_extended: u16,
+    pub path: *const c_char,
+}
+
+pub const GIT_IDXENTRY_NAMEMASK: u16 = 0xfff;
+pub const GIT_IDXENTRY_STAGEMASK: u16 = 0x3000;
+pub const GIT_IDXENTRY_STAGESHIFT: u16 = 12;
+
+#[repr(C)]
+#[derive(Copy, Clone, Eq, PartialEq)]
+pub struct git_index_time {
+    pub seconds: i32,
+    pub nanoseconds: u32,
+}
+
+#[repr(C)]
+pub struct git_config_entry {
+    pub name: *const c_char,
+    pub value: *const c_char,
+    pub include_depth: c_uint,
+    pub level: git_config_level_t,
+    pub free: extern fn(*mut git_config_entry),
+    pub payload: *mut c_void,
+}
+
+git_enum! {
+    pub enum git_config_level_t: c_int {
+        GIT_CONFIG_LEVEL_PROGRAMDATA = 1,
+        GIT_CONFIG_LEVEL_SYSTEM = 2,
+        GIT_CONFIG_LEVEL_XDG = 3,
+        GIT_CONFIG_LEVEL_GLOBAL = 4,
+        GIT_CONFIG_LEVEL_LOCAL = 5,
+        GIT_CONFIG_LEVEL_APP = 6,
+        GIT_CONFIG_HIGHEST_LEVEL = -1,
+    }
+}
+
+git_enum! {
+    pub enum git_submodule_update_t {
+        GIT_SUBMODULE_UPDATE_CHECKOUT = 1,
+        GIT_SUBMODULE_UPDATE_REBASE   = 2,
+        GIT_SUBMODULE_UPDATE_MERGE    = 3,
+        GIT_SUBMODULE_UPDATE_NONE     = 4,
+        GIT_SUBMODULE_UPDATE_DEFAULT  = 0,
+    }
+}
+
+git_enum! {
+    pub enum git_submodule_ignore_t: c_int {
+        GIT_SUBMODULE_IGNORE_UNSPECIFIED = -1,
+
+        GIT_SUBMODULE_IGNORE_NONE      = 1,
+        GIT_SUBMODULE_IGNORE_UNTRACKED = 2,
+        GIT_SUBMODULE_IGNORE_DIRTY     = 3,
+        GIT_SUBMODULE_IGNORE_ALL       = 4,
+    }
+}
+
+pub type git_submodule_cb = extern fn(*mut git_submodule,
+                                      *const c_char,
+                                      *mut c_void) -> c_int;
+
+#[repr(C)]
+pub struct git_submodule_update_options {
+    pub version: c_uint,
+    pub checkout_opts: git_checkout_options,
+    pub fetch_opts: git_fetch_options,
+    pub allow_fetch: c_int,
+}
+
+#[repr(C)]
+pub struct git_writestream {
+    pub write: extern fn(*mut git_writestream,
+                         *const c_char,
+                         size_t) -> c_int,
+    pub close: extern fn(*mut git_writestream) -> c_int,
+    pub free: extern fn(*mut git_writestream),
+}
+
+#[repr(C)]
+pub struct git_cred {
+    pub credtype: git_credtype_t,
+    pub free: extern fn(*mut git_cred),
+}
+
+git_enum! {
+    pub enum git_credtype_t {
+        GIT_CREDTYPE_USERPASS_PLAINTEXT = 1 << 0,
+        GIT_CREDTYPE_SSH_KEY = 1 << 1,
+        GIT_CREDTYPE_SSH_CUSTOM = 1 << 2,
+        GIT_CREDTYPE_DEFAULT = 1 << 3,
+        GIT_CREDTYPE_SSH_INTERACTIVE = 1 << 4,
+        GIT_CREDTYPE_USERNAME = 1 << 5,
+        GIT_CREDTYPE_SSH_MEMORY = 1 << 6,
+    }
+}
+
+pub type git_cred_ssh_interactive_callback = extern fn(
+    name: *const c_char,
+    name_len: c_int,
+    instruction: *const c_char,
+    instruction_len: c_int,
+    num_prompts: c_int,
+    prompts: *const LIBSSH2_USERAUTH_KBDINT_PROMPT,
+    responses: *mut LIBSSH2_USERAUTH_KBDINT_RESPONSE,
+    abstrakt: *mut *mut c_void
+);
+
+pub type git_cred_sign_callback = extern fn(
+    session: *mut LIBSSH2_SESSION,
+    sig: *mut *mut c_uchar,
+    sig_len: *mut size_t,
+    data: *const c_uchar,
+    data_len: size_t,
+    abstrakt: *mut *mut c_void,
+);
+
+pub enum LIBSSH2_SESSION {}
+pub enum LIBSSH2_USERAUTH_KBDINT_PROMPT {}
+pub enum LIBSSH2_USERAUTH_KBDINT_RESPONSE {}
+
+#[repr(C)]
+pub struct git_push_options {
+    pub version: c_uint,
+    pub pb_parallelism: c_uint,
+    pub callbacks: git_remote_callbacks,
+    pub proxy_opts: git_proxy_options,
+    pub custom_headers: git_strarray,
+}
+
+pub type git_tag_foreach_cb = extern fn(name: *const c_char,
+                                        oid: *mut git_oid,
+                                        payload: *mut c_void) -> c_int;
+
+git_enum! {
+    pub enum git_index_add_option_t {
+        GIT_INDEX_ADD_DEFAULT = 0,
+        GIT_INDEX_ADD_FORCE = 1 << 0,
+        GIT_INDEX_ADD_DISABLE_PATHSPEC_MATCH = 1 << 1,
+        GIT_INDEX_ADD_CHECK_PATHSPEC = 1 << 2,
+    }
+}
+
+git_enum! {
+    pub enum git_repository_open_flag_t {
+        GIT_REPOSITORY_OPEN_NO_SEARCH = (1 << 0),
+        GIT_REPOSITORY_OPEN_CROSS_FS = (1 << 1),
+        GIT_REPOSITORY_OPEN_BARE = (1 << 2),
+        GIT_REPOSITORY_OPEN_NO_DOTGIT = (1 << 3),
+        GIT_REPOSITORY_OPEN_FROM_ENV = (1 << 4),
+    }
+}
+
+#[repr(C)]
+pub struct git_repository_init_options {
+    pub version: c_uint,
+    pub flags: u32,
+    pub mode: u32,
+    pub workdir_path: *const c_char,
+    pub description: *const c_char,
+    pub template_path: *const c_char,
+    pub initial_head: *const c_char,
+    pub origin_url: *const c_char,
+}
+
+pub const GIT_REPOSITORY_INIT_OPTIONS_VERSION: c_uint = 1;
+
+git_enum! {
+    pub enum git_repository_init_flag_t {
+        GIT_REPOSITORY_INIT_BARE              = (1 << 0),
+        GIT_REPOSITORY_INIT_NO_REINIT         = (1 << 1),
+        GIT_REPOSITORY_INIT_NO_DOTGIT_DIR     = (1 << 2),
+        GIT_REPOSITORY_INIT_MKDIR             = (1 << 3),
+        GIT_REPOSITORY_INIT_MKPATH            = (1 << 4),
+        GIT_REPOSITORY_INIT_EXTERNAL_TEMPLATE = (1 << 5),
+    }
+}
+
+git_enum! {
+    pub enum git_repository_init_mode_t {
+        GIT_REPOSITORY_INIT_SHARED_UMASK = 0,
+        GIT_REPOSITORY_INIT_SHARED_GROUP = 0o002775,
+        GIT_REPOSITORY_INIT_SHARED_ALL   = 0o002777,
+    }
+}
+
+git_enum! {
+    pub enum git_sort_t {
+        GIT_SORT_NONE        = 0,
+        GIT_SORT_TOPOLOGICAL = (1 << 0),
+        GIT_SORT_TIME        = (1 << 1),
+        GIT_SORT_REVERSE     = (1 << 2),
+    }
+}
+
+git_enum! {
+    pub enum git_submodule_status_t {
+        GIT_SUBMODULE_STATUS_IN_HEAD = 1 << 0,
+        GIT_SUBMODULE_STATUS_IN_INDEX = 1 << 1,
+        GIT_SUBMODULE_STATUS_IN_CONFIG = 1 << 2,
+        GIT_SUBMODULE_STATUS_IN_WD = 1 << 3,
+        GIT_SUBMODULE_STATUS_INDEX_ADDED = 1 << 4,
+        GIT_SUBMODULE_STATUS_INDEX_DELETED = 1 << 5,
+        GIT_SUBMODULE_STATUS_INDEX_MODIFIED = 1 << 6,
+        GIT_SUBMODULE_STATUS_WD_UNINITIALIZED = 1 << 7,
+        GIT_SUBMODULE_STATUS_WD_ADDED = 1 << 8,
+        GIT_SUBMODULE_STATUS_WD_DELETED = 1 << 9,
+        GIT_SUBMODULE_STATUS_WD_MODIFIED = 1 << 10,
+        GIT_SUBMODULE_STATUS_WD_INDEX_MODIFIED = 1 << 11,
+        GIT_SUBMODULE_STATUS_WD_WD_MODIFIED = 1 << 12,
+        GIT_SUBMODULE_STATUS_WD_UNTRACKED = 1 << 13,
+    }
+}
+
+#[repr(C)]
+pub struct git_remote_head {
+    pub local: c_int,
+    pub oid: git_oid,
+    pub loid: git_oid,
+    pub name: *mut c_char,
+    pub symref_target: *mut c_char,
+}
+
+git_enum! {
+    pub enum git_pathspec_flag_t {
+        GIT_PATHSPEC_DEFAULT = 0,
+        GIT_PATHSPEC_IGNORE_CASE = 1 << 0,
+        GIT_PATHSPEC_USE_CASE = 1 << 1,
+        GIT_PATHSPEC_NO_GLOB = 1 << 2,
+        GIT_PATHSPEC_NO_MATCH_ERROR = 1 << 3,
+        GIT_PATHSPEC_FIND_FAILURES = 1 << 4,
+        GIT_PATHSPEC_FAILURES_ONLY = 1 << 5,
+    }
+}
+
+pub type git_diff_file_cb = extern fn(*const git_diff_delta, f32, *mut c_void)
+                                      -> c_int;
+pub type git_diff_hunk_cb = extern fn(*const git_diff_delta,
+                                      *const git_diff_hunk,
+                                      *mut c_void) -> c_int;
+pub type git_diff_line_cb = extern fn(*const git_diff_delta,
+                                      *const git_diff_hunk,
+                                      *const git_diff_line,
+                                      *mut c_void) -> c_int;
+pub type git_diff_binary_cb = extern fn(*const git_diff_delta,
+                                        *const git_diff_binary,
+                                        *mut c_void) -> c_int;
+
+#[repr(C)]
+pub struct git_diff_hunk {
+    pub old_start: c_int,
+    pub old_lines: c_int,
+    pub new_start: c_int,
+    pub new_lines: c_int,
+    pub header_len: size_t,
+    pub header: [c_char; 128],
+}
+
+git_enum! {
+    pub enum git_diff_line_t {
+        GIT_DIFF_LINE_CONTEXT = b' ' as git_diff_line_t,
+        GIT_DIFF_LINE_ADDITION = b'+' as git_diff_line_t,
+        GIT_DIFF_LINE_DELETION = b'-' as git_diff_line_t,
+        GIT_DIFF_LINE_CONTEXT_EOFNL = b'=' as git_diff_line_t,
+        GIT_DIFF_LINE_ADD_EOFNL = b'>' as git_diff_line_t,
+        GIT_DIFF_LINE_DEL_EOFNL = b'<' as git_diff_line_t,
+        GIT_DIFF_LINE_FILE_HDR = b'F' as git_diff_line_t,
+        GIT_DIFF_LINE_HUNK_HDR = b'H' as git_diff_line_t,
+        GIT_DIFF_LINE_BINARY = b'B' as git_diff_line_t,
+    }
+}
+
+#[repr(C)]
+pub struct git_diff_line {
+    pub origin: c_char,
+    pub old_lineno: c_int,
+    pub new_lineno: c_int,
+    pub num_lines: c_int,
+    pub content_len: size_t,
+    pub content_offset: git_off_t,
+    pub content: *const c_char,
+}
+
+#[repr(C)]
+pub struct git_diff_options {
+    pub version: c_uint,
+    pub flags: u32,
+    pub ignore_submodules: git_submodule_ignore_t,
+    pub pathspec: git_strarray,
+    pub notify_cb: git_diff_notify_cb,
+    pub progress_cb: git_diff_progress_cb,
+    pub payload: *mut c_void,
+    pub context_lines: u32,
+    pub interhunk_lines: u32,
+    pub id_abbrev: u16,
+    pub max_size: git_off_t,
+    pub old_prefix: *const c_char,
+    pub new_prefix: *const c_char,
+}
+
+git_enum! {
+    pub enum git_diff_format_t {
+        GIT_DIFF_FORMAT_PATCH = 1,
+        GIT_DIFF_FORMAT_PATCH_HEADER = 2,
+        GIT_DIFF_FORMAT_RAW = 3,
+        GIT_DIFF_FORMAT_NAME_ONLY = 4,
+        GIT_DIFF_FORMAT_NAME_STATUS = 5,
+    }
+}
+
+git_enum! {
+    pub enum git_diff_stats_format_t {
+        GIT_DIFF_STATS_NONE = 0,
+        GIT_DIFF_STATS_FULL = 1 << 0,
+        GIT_DIFF_STATS_SHORT = 1 << 1,
+        GIT_DIFF_STATS_NUMBER = 1 << 2,
+        GIT_DIFF_STATS_INCLUDE_SUMMARY = 1 << 3,
+    }
+}
+
+pub type git_diff_notify_cb = extern fn(*const git_diff,
+                                        *const git_diff_delta,
+                                        *const c_char,
+                                        *mut c_void) -> c_int;
+
+pub type git_diff_progress_cb = extern fn (*const git_diff,
+                                           *const c_char,
+                                           *const c_char,
+                                           *mut c_void) -> c_int;
+
+pub type git_diff_option_t = i32;
+pub const GIT_DIFF_NORMAL: git_diff_option_t = 0;
+pub const GIT_DIFF_REVERSE: git_diff_option_t = 1 << 0;
+pub const GIT_DIFF_INCLUDE_IGNORED: git_diff_option_t = 1 << 1;
+pub const GIT_DIFF_RECURSE_IGNORED_DIRS: git_diff_option_t = 1 << 2;
+pub const GIT_DIFF_INCLUDE_UNTRACKED: git_diff_option_t = 1 << 3;
+pub const GIT_DIFF_RECURSE_UNTRACKED_DIRS: git_diff_option_t = 1 << 4;
+pub const GIT_DIFF_INCLUDE_UNMODIFIED: git_diff_option_t = 1 << 5;
+pub const GIT_DIFF_INCLUDE_TYPECHANGE: git_diff_option_t = 1 << 6;
+pub const GIT_DIFF_INCLUDE_TYPECHANGE_TREES: git_diff_option_t = 1 << 7;
+pub const GIT_DIFF_IGNORE_FILEMODE: git_diff_option_t = 1 << 8;
+pub const GIT_DIFF_IGNORE_SUBMODULES: git_diff_option_t = 1 << 9;
+pub const GIT_DIFF_IGNORE_CASE: git_diff_option_t = 1 << 10;
+pub const GIT_DIFF_DISABLE_PATHSPEC_MATCH: git_diff_option_t = 1 << 12;
+pub const GIT_DIFF_SKIP_BINARY_CHECK: git_diff_option_t = 1 << 13;
+pub const GIT_DIFF_ENABLE_FAST_UNTRACKED_DIRS: git_diff_option_t = 1 << 14;
+pub const GIT_DIFF_UPDATE_INDEX: git_diff_option_t = 1 << 15;
+pub const GIT_DIFF_INCLUDE_UNREADABLE: git_diff_option_t = 1 << 16;
+pub const GIT_DIFF_INCLUDE_UNREADABLE_AS_UNTRACKED: git_diff_option_t = 1 << 17;
+pub const GIT_DIFF_FORCE_TEXT: git_diff_option_t = 1 << 20;
+pub const GIT_DIFF_FORCE_BINARY: git_diff_option_t = 1 << 21;
+pub const GIT_DIFF_IGNORE_WHITESPACE: git_diff_option_t = 1 << 22;
+pub const GIT_DIFF_IGNORE_WHITESPACE_CHANGE: git_diff_option_t = 1 << 23;
+pub const GIT_DIFF_IGNORE_WHITESPACE_EOL: git_diff_option_t = 1 << 24;
+pub const GIT_DIFF_SHOW_UNTRACKED_CONTENT: git_diff_option_t = 1 << 25;
+pub const GIT_DIFF_SHOW_UNMODIFIED: git_diff_option_t = 1 << 26;
+pub const GIT_DIFF_PATIENCE: git_diff_option_t = 1 << 28;
+pub const GIT_DIFF_MINIMAL: git_diff_option_t = 1 << 29;
+pub const GIT_DIFF_SHOW_BINARY: git_diff_option_t = 1 << 30;
+pub const GIT_DIFF_INDENT_HEURISTIC: git_diff_option_t = 1 << 31;
+
+#[repr(C)]
+pub struct git_diff_find_options {
+    pub version: c_uint,
+    pub flags: u32,
+    pub rename_threshold: u16,
+    pub rename_from_rewrite_threshold: u16,
+    pub copy_threshold: u16,
+    pub break_rewrite_threshold: u16,
+    pub rename_limit: size_t,
+    pub metric: *mut git_diff_similarity_metric,
+}
+
+#[repr(C)]
+pub struct git_diff_similarity_metric {
+    pub file_signature: extern fn(*mut *mut c_void,
+                                  *const git_diff_file,
+                                  *const c_char,
+                                  *mut c_void) -> c_int,
+    pub buffer_signature: extern fn(*mut *mut c_void,
+                                    *const git_diff_file,
+                                    *const c_char,
+                                    size_t,
+                                    *mut c_void) -> c_int,
+    pub free_signature: extern fn(*mut c_void, *mut c_void),
+    pub similarity: extern fn(*mut c_int, *mut c_void, *mut c_void,
+                              *mut c_void) -> c_int,
+    pub payload: *mut c_void,
+}
+
+pub const GIT_DIFF_FIND_OPTIONS_VERSION: c_uint = 1;
+
+pub const GIT_DIFF_FIND_BY_CONFIG: u32 = 0;
+pub const GIT_DIFF_FIND_RENAMES: u32 = 1 << 0;
+pub const GIT_DIFF_FIND_RENAMES_FROM_REWRITES: u32 = 1 << 1;
+pub const GIT_DIFF_FIND_COPIES: u32 = 1 << 2;
+pub const GIT_DIFF_FIND_COPIES_FROM_UNMODIFIED: u32 = 1 << 3;
+pub const GIT_DIFF_FIND_REWRITES: u32 = 1 << 4;
+pub const GIT_DIFF_BREAK_REWRITES: u32 = 1 << 5;
+pub const GIT_DIFF_FIND_AND_BREAK_REWRITES: u32 =
+        GIT_DIFF_FIND_REWRITES | GIT_DIFF_BREAK_REWRITES;
+pub const GIT_DIFF_FIND_FOR_UNTRACKED: u32 = 1 << 6;
+pub const GIT_DIFF_FIND_ALL: u32 = 0x0ff;
+pub const GIT_DIFF_FIND_IGNORE_LEADING_WHITESPACE: u32 = 0;
+pub const GIT_DIFF_FIND_IGNORE_WHITESPACE: u32 = 1 << 12;
+pub const GIT_DIFF_FIND_DONT_IGNORE_WHITESPACE: u32 = 1 << 13;
+pub const GIT_DIFF_FIND_EXACT_MATCH_ONLY: u32 = 1 << 14;
+pub const GIT_DIFF_BREAK_REWRITES_FOR_RENAMES_ONLY : u32 = 1 << 15;
+pub const GIT_DIFF_FIND_REMOVE_UNMODIFIED: u32 = 1 << 16;
+
+#[repr(C)]
+pub struct git_diff_binary {
+    pub contains_data: c_uint,
+    pub old_file: git_diff_binary_file,
+    pub new_file: git_diff_binary_file,
+}
+
+#[repr(C)]
+pub struct git_diff_binary_file {
+    pub kind: git_diff_binary_t,
+    pub data: *const c_char,
+    pub datalen: size_t,
+    pub inflatedlen: size_t,
+}
+
+git_enum! {
+    pub enum git_diff_binary_t {
+        GIT_DIFF_BINARY_NONE,
+        GIT_DIFF_BINARY_LITERAL,
+        GIT_DIFF_BINARY_DELTA,
+    }
+}
+
+#[repr(C)]
+pub struct git_merge_options {
+    pub version: c_uint,
+    pub flags: git_merge_flag_t,
+    pub rename_threshold: c_uint,
+    pub target_limit: c_uint,
+    pub metric: *mut git_diff_similarity_metric,
+    pub recursion_limit: c_uint,
+    pub default_driver: *const c_char,
+    pub file_favor: git_merge_file_favor_t,
+    pub file_flags: git_merge_file_flag_t,
+}
+
+git_enum! {
+    pub enum git_merge_flag_t {
+        GIT_MERGE_FIND_RENAMES = 1 << 0,
+        GIT_MERGE_FAIL_ON_CONFLICT = 1 << 1,
+        GIT_MERGE_SKIP_REUC = 1 << 2,
+        GIT_MERGE_NO_RECURSIVE = 1 << 3,
+    }
+}
+
+git_enum! {
+    pub enum git_merge_file_favor_t {
+        GIT_MERGE_FILE_FAVOR_NORMAL = 0,
+        GIT_MERGE_FILE_FAVOR_OURS = 1,
+        GIT_MERGE_FILE_FAVOR_THEIRS = 2,
+        GIT_MERGE_FILE_FAVOR_UNION = 3,
+    }
+}
+
+git_enum! {
+    pub enum git_merge_file_flag_t {
+        GIT_MERGE_FILE_DEFAULT = 0,
+        GIT_MERGE_FILE_STYLE_MERGE = (1 << 0),
+        GIT_MERGE_FILE_STYLE_DIFF3 = (1 << 1),
+        GIT_MERGE_FILE_SIMPLIFY_ALNUM = (1 << 2),
+        GIT_MERGE_FILE_IGNORE_WHITESPACE = (1 << 3),
+        GIT_MERGE_FILE_IGNORE_WHITESPACE_CHANGE = (1 << 4),
+        GIT_MERGE_FILE_IGNORE_WHITESPACE_EOL = (1 << 5),
+        GIT_MERGE_FILE_DIFF_PATIENCE = (1 << 6),
+        GIT_MERGE_FILE_DIFF_MINIMAL = (1 << 7),
+    }
+}
+
+git_enum! {
+    pub enum git_merge_analysis_t {
+        GIT_MERGE_ANALYSIS_NONE = 0,
+        GIT_MERGE_ANALYSIS_NORMAL = (1 << 0),
+        GIT_MERGE_ANALYSIS_UP_TO_DATE = (1 << 1),
+        GIT_MERGE_ANALYSIS_FASTFORWARD = (1 << 2),
+        GIT_MERGE_ANALYSIS_UNBORN = (1 << 3),
+    }
+}
+
+git_enum! {
+    pub enum git_merge_preference_t {
+        GIT_MERGE_PREFERENCE_NONE = 0,
+        GIT_MERGE_PREFERENCE_NO_FASTFORWARD = (1 << 0),
+        GIT_MERGE_PREFERENCE_FASTFORWARD_ONLY = (1 << 1),
+    }
+}
+
+pub type git_transport_cb = extern fn(out: *mut *mut git_transport,
+                                      owner: *mut git_remote,
+                                      param: *mut c_void) -> c_int;
+
+#[repr(C)]
+pub struct git_transport {
+    pub version: c_uint,
+    pub set_callbacks: extern fn(*mut git_transport,
+                                 git_transport_message_cb,
+                                 git_transport_message_cb,
+                                 git_transport_certificate_check_cb,
+                                 *mut c_void) -> c_int,
+    pub set_custom_headers: extern fn(*mut git_transport,
+                                      *const git_strarray) -> c_int,
+    pub connect: extern fn(*mut git_transport,
+                           *const c_char,
+                           git_cred_acquire_cb,
+                           *mut c_void,
+                           *const git_proxy_options,
+                           c_int, c_int) -> c_int,
+    pub ls: extern fn(*mut *mut *const git_remote_head,
+                      *mut size_t,
+                      *mut git_transport) -> c_int,
+    pub push: extern fn(*mut git_transport,
+                        *mut git_push,
+                        *const git_remote_callbacks) -> c_int,
+    pub negotiate_fetch: extern fn(*mut git_transport,
+                                   *mut git_repository,
+                                   *const *const git_remote_head,
+                                   size_t) -> c_int,
+    pub download_pack: extern fn(*mut git_transport,
+                                 *mut git_repository,
+                                 *mut git_transfer_progress,
+                                 git_transfer_progress_cb,
+                                 *mut c_void) -> c_int,
+    pub is_connected: extern fn(*mut git_transport) -> c_int,
+    pub read_flags: extern fn(*mut git_transport, *mut c_int) -> c_int,
+    pub cancel: extern fn(*mut git_transport),
+    pub close: extern fn(*mut git_transport) -> c_int,
+    pub free: extern fn(*mut git_transport),
+}
+
+#[repr(C)]
+pub struct git_odb_backend {
+    pub version: c_uint,
+    pub odb: *mut git_odb,
+    pub read: extern fn(*mut *mut c_void,
+                        *mut size_t,
+                        *mut git_otype,
+                        *mut git_odb_backend,
+                        *const git_oid) -> c_int,
+
+    pub read_prefix: extern fn(*mut git_oid,
+                               *mut *mut c_void,
+                               *mut size_t,
+                               *mut git_otype,
+                               *mut git_odb_backend,
+                               *const git_oid,
+                               size_t) -> c_int,
+    pub read_header: extern fn(*mut size_t,
+                               *mut git_otype,
+                               *mut git_odb_backend,
+                               *const git_oid) -> c_int,
+
+    pub write: extern fn(*mut git_odb_backend,
+                         *const git_oid,
+                         *const c_void,
+                         size_t,
+                         git_otype) -> c_int,
+
+    pub writestream: extern fn(*mut *mut git_odb_stream,
+                               *mut git_odb_backend,
+                               git_off_t,
+                               git_otype) -> c_int,
+
+    pub readstream: extern fn(*mut *mut git_odb_stream,
+                              *mut size_t,
+                              *mut git_otype,
+                              *mut git_odb_backend,
+                              *const git_oid) -> c_int,
+
+    pub exists: extern fn(*mut git_odb_backend,
+                          *const git_oid) -> c_int,
+
+    pub exists_prefix: extern fn(*mut git_oid,
+                                 *mut git_odb_backend,
+                                 *const git_oid,
+                                 size_t) -> c_int,
+
+    pub refresh: extern fn(*mut git_odb_backend) -> c_int,
+
+    pub foreach: extern fn(*mut git_odb_backend,
+                           git_odb_foreach_cb,
+                           *mut c_void) -> c_int,
+
+    pub writepack: extern fn(*mut *mut git_odb_writepack,
+                             *mut git_odb_backend,
+                             *mut git_odb,
+                             git_transfer_progress_cb,
+                             *mut c_void) -> c_int,
+
+    pub freshen: extern fn(*mut git_odb_backend,
+                           *const git_oid) -> c_int,
+
+    pub free: extern fn(*mut git_odb_backend),
+}
+
+#[repr(C)]
+pub struct git_refdb_backend {
+    pub version: c_uint,
+    pub exists: extern fn(*mut c_int,
+                          *mut git_refdb_backend,
+                          *const c_char) -> c_int,
+    pub lookup: extern fn(*mut *mut git_reference,
+                          *mut git_refdb_backend,
+                          *const c_char) -> c_int,
+    pub iterator: extern fn(*mut *mut git_reference_iterator,
+                            *mut git_refdb_backend,
+                            *const c_char) -> c_int,
+    pub write: extern fn(*mut git_refdb_backend,
+                         *const git_reference,
+                         c_int,
+                         *const git_signature,
+                         *const c_char,
+                         *const git_oid,
+                         *const c_char) -> c_int,
+    pub rename: extern fn(*mut *mut git_reference,
+                          *mut git_refdb_backend,
+                          *const c_char,
+                          *const c_char,
+                          c_int,
+                          *const git_signature,
+                          *const c_char) -> c_int,
+    pub del: extern fn(*mut git_refdb_backend,
+                       *const c_char,
+                       *const git_oid,
+                       *const c_char) -> c_int,
+    pub compress: extern fn(*mut git_refdb_backend) -> c_int,
+    pub has_log: extern fn(*mut git_refdb_backend,
+                           *const c_char) -> c_int,
+    pub ensure_log: extern fn(*mut git_refdb_backend,
+                              *const c_char) -> c_int,
+    pub free: extern fn(*mut git_refdb_backend),
+    pub reflog_read: extern fn(*mut *mut git_reflog,
+                               *mut git_refdb_backend,
+                               *const c_char) -> c_int,
+    pub reflog_write: extern fn(*mut git_refdb_backend,
+                                *mut git_reflog) -> c_int,
+    pub reflog_rename: extern fn(*mut git_refdb_backend,
+                                 *const c_char,
+                                 *const c_char) -> c_int,
+    pub reflog_delete: extern fn(*mut git_refdb_backend,
+                                 *const c_char) -> c_int,
+    pub lock: extern fn(*mut *mut c_void,
+                        *mut git_refdb_backend,
+                        *const c_char) -> c_int,
+    pub unlock: extern fn(*mut git_refdb_backend,
+                          *mut c_void,
+                          c_int,
+                          c_int,
+                          *const git_reference,
+                          *const git_signature,
+                          *const c_char) -> c_int
+}
+
+#[repr(C)]
+pub struct git_proxy_options {
+    pub version: c_uint,
+    pub kind: git_proxy_t,
+    pub url: *const c_char,
+    pub credentials: Option<git_cred_acquire_cb>,
+    pub certificate_check: Option<git_transport_certificate_check_cb>,
+    pub payload: *mut c_void,
+}
+
+git_enum! {
+    pub enum git_proxy_t {
+        GIT_PROXY_NONE = 0,
+        GIT_PROXY_AUTO = 1,
+        GIT_PROXY_SPECIFIED = 2,
+    }
+}
+
+git_enum! {
+    pub enum git_smart_service_t {
+        GIT_SERVICE_UPLOADPACK_LS = 1,
+        GIT_SERVICE_UPLOADPACK = 2,
+        GIT_SERVICE_RECEIVEPACK_LS = 3,
+        GIT_SERVICE_RECEIVEPACK = 4,
+    }
+}
+
+#[repr(C)]
+pub struct git_smart_subtransport_stream {
+    pub subtransport: *mut git_smart_subtransport,
+    pub read: extern fn(*mut git_smart_subtransport_stream,
+                        *mut c_char,
+                        size_t,
+                        *mut size_t) -> c_int,
+    pub write: extern fn(*mut git_smart_subtransport_stream,
+                         *const c_char,
+                         size_t) -> c_int,
+    pub free: extern fn(*mut git_smart_subtransport_stream),
+}
+
+#[repr(C)]
+pub struct git_smart_subtransport {
+    pub action: extern fn(*mut *mut git_smart_subtransport_stream,
+                          *mut git_smart_subtransport,
+                          *const c_char,
+                          git_smart_service_t) -> c_int,
+    pub close: extern fn(*mut git_smart_subtransport) -> c_int,
+    pub free: extern fn(*mut git_smart_subtransport),
+}
+
+pub type git_smart_subtransport_cb = extern fn(*mut *mut git_smart_subtransport,
+                                               *mut git_transport,
+                                               *mut c_void) -> c_int;
+
+#[repr(C)]
+pub struct git_smart_subtransport_definition {
+    pub callback: git_smart_subtransport_cb,
+    pub rpc: c_uint,
+    pub param: *mut c_void,
+}
+
+#[repr(C)]
+pub struct git_describe_options {
+    pub version: c_uint,
+    pub max_candidates_tags: c_uint,
+    pub describe_strategy: c_uint,
+    pub pattern: *const c_char,
+    pub only_follow_first_parent: c_int,
+    pub show_commit_oid_as_fallback: c_int,
+}
+
+git_enum! {
+    pub enum git_describe_strategy_t {
+        GIT_DESCRIBE_DEFAULT,
+        GIT_DESCRIBE_TAGS,
+        GIT_DESCRIBE_ALL,
+    }
+}
+
+#[repr(C)]
+pub struct git_describe_format_options {
+    pub version: c_uint,
+    pub abbreviated_size: c_uint,
+    pub always_use_long_format: c_int,
+    pub dirty_suffix: *const c_char,
+}
+
+git_enum! {
+    pub enum git_packbuilder_stage_t {
+        GIT_PACKBUILDER_ADDING_OBJECTS,
+        GIT_PACKBUILDER_DELTAFICATION,
+    }
+}
+
+git_enum! {
+    pub enum git_stash_flags {
+        GIT_STASH_DEFAULT = 0,
+        GIT_STASH_KEEP_INDEX = 1 << 0,
+        GIT_STASH_INCLUDE_UNTRACKED = 1 << 1,
+        GIT_STASH_INCLUDE_IGNORED = 1 << 2,
+    }
+}
+
+git_enum! {
+    pub enum git_stash_apply_flags {
+        GIT_STASH_APPLY_DEFAULT = 0,
+        GIT_STASH_APPLY_REINSTATE_INDEX = 1 << 0,
+    }
+}
+
+git_enum! {
+    pub enum git_stash_apply_progress_t {
+        GIT_STASH_APPLY_PROGRESS_NONE = 0,
+        GIT_STASH_APPLY_PROGRESS_LOADING_STASH,
+        GIT_STASH_APPLY_PROGRESS_ANALYZE_INDEX,
+        GIT_STASH_APPLY_PROGRESS_ANALYZE_MODIFIED,
+        GIT_STASH_APPLY_PROGRESS_ANALYZE_UNTRACKED,
+        GIT_STASH_APPLY_PROGRESS_CHECKOUT_UNTRACKED,
+        GIT_STASH_APPLY_PROGRESS_CHECKOUT_MODIFIED,
+        GIT_STASH_APPLY_PROGRESS_DONE,
+    }
+}
+
+#[repr(C)]
+pub struct git_stash_apply_options {
+    pub version: c_uint,
+    pub flags: git_stash_apply_flags,
+    pub checkout_options: git_checkout_options,
+    pub progress_cb: git_stash_apply_progress_cb,
+    pub progress_payload: *mut c_void,
+}
+
+pub type git_stash_apply_progress_cb = extern fn(progress: git_stash_apply_progress_t,
+                                                 payload: *mut c_void) -> c_int;
+
+pub type git_stash_cb = extern fn(index: size_t,
+                                  message: *const c_char,
+                                  stash_id: *const git_oid,
+                                  payload: *mut c_void) -> c_int;
+
+pub type git_packbuilder_foreach_cb = extern fn(*const c_void, size_t,
+                                                *mut c_void) -> c_int;
+
+pub type git_odb_foreach_cb = extern fn(id: *const git_oid, payload: *mut c_void) -> c_int;
+
+pub const GIT_REBASE_NO_OPERATION: usize = usize::max_value();
+
+#[repr(C)]
+pub struct git_rebase_options {
+    pub version: c_uint,
+    pub quiet: c_int,
+    pub inmemory: c_int,
+    pub rewrite_notes_ref: *const c_char,
+    pub merge_options: git_merge_options,
+    pub checkout_options: git_checkout_options,
+}
+
+git_enum! {
+    pub enum git_rebase_operation_t {
+        GIT_REBASE_OPERATION_PICK = 0,
+        GIT_REBASE_OPERATION_REWORD,
+        GIT_REBASE_OPERATION_EDIT,
+        GIT_REBASE_OPERATION_SQUASH,
+        GIT_REBASE_OPERATION_FIXUP,
+        GIT_REBASE_OPERATION_EXEC,
+    }
+}
+
+#[repr(C)]
+pub struct git_rebase_operation {
+    pub kind: git_rebase_operation_t,
+    pub id: git_oid,
+    pub exec: *const c_char,
+}
+
+extern {
+    // threads
+    pub fn git_libgit2_init() -> c_int;
+    pub fn git_libgit2_shutdown() -> c_int;
+
+    // repository
+    pub fn git_repository_new(out: *mut *mut git_repository) -> c_int;
+    pub fn git_repository_free(repo: *mut git_repository);
+    pub fn git_repository_open(repo: *mut *mut git_repository,
+                               path: *const c_char) -> c_int;
+    pub fn git_repository_open_bare(repo: *mut *mut git_repository,
+                                    path: *const c_char) -> c_int;
+    pub fn git_repository_open_ext(repo: *mut *mut git_repository,
+                                   path: *const c_char,
+                                   flags: c_uint,
+                                   ceiling_dirs: *const c_char) -> c_int;
+    pub fn git_repository_open_from_worktree(repo: *mut *mut git_repository,
+                                             worktree: *mut git_worktree) -> c_int;
+    pub fn git_repository_wrap_odb(repo: *mut *mut git_repository,
+                                   odb: *mut git_odb) -> c_int;
+    pub fn git_repository_init(repo: *mut *mut git_repository,
+                               path: *const c_char,
+                               is_bare: c_uint) -> c_int;
+    pub fn git_repository_init_ext(out: *mut *mut git_repository,
+                                   repo_path: *const c_char,
+                                   opts: *mut git_repository_init_options)
+                                   -> c_int;
+    pub fn git_repository_init_init_options(opts: *mut git_repository_init_options,
+                                            version: c_uint) -> c_int;
+    pub fn git_repository_get_namespace(repo: *mut git_repository)
+                                        -> *const c_char;
+    pub fn git_repository_set_namespace(repo: *mut git_repository,
+                                        namespace: *const c_char) -> c_int;
+    pub fn git_repository_head(out: *mut *mut git_reference,
+                               repo: *mut git_repository) -> c_int;
+    pub fn git_repository_set_head(repo: *mut git_repository,
+                                   refname: *const c_char) -> c_int;
+
+    pub fn git_repository_head_detached(repo: *mut git_repository) -> c_int;
+    pub fn git_repository_set_head_detached(repo: *mut git_repository,
+                                            commitish: *const git_oid) -> c_int;
+    pub fn git_repository_set_bare(repo: *mut git_repository) -> c_int;
+    pub fn git_repository_is_worktree(repo: *const git_repository) -> c_int;
+    pub fn git_repository_is_bare(repo: *const git_repository) -> c_int;
+    pub fn git_repository_is_empty(repo: *mut git_repository) -> c_int;
+    pub fn git_repository_is_shallow(repo: *mut git_repository) -> c_int;
+    pub fn git_repository_path(repo: *const git_repository) -> *const c_char;
+    pub fn git_repository_state(repo: *mut git_repository) -> c_int;
+    pub fn git_repository_workdir(repo: *const git_repository) -> *const c_char;
+    pub fn git_repository_set_workdir(repo: *mut git_repository,
+                                      workdir: *const c_char,
+                                      update_gitlink: c_int) -> c_int;
+    pub fn git_repository_index(out: *mut *mut git_index,
+                                repo: *mut git_repository) -> c_int;
+    pub fn git_repository_set_index(repo: *mut git_repository,
+                                    index: *mut git_index);
+
+    pub fn git_repository_message(buf: *mut git_buf,
+                                  repo: *mut git_repository) -> c_int;
+
+    pub fn git_repository_message_remove(repo: *mut git_repository) -> c_int;
+    pub fn git_repository_config(out: *mut *mut git_config,
+                                 repo: *mut git_repository) -> c_int;
+    pub fn git_repository_set_config(repo: *mut git_repository,
+                                     config: *mut git_config);
+    pub fn git_repository_config_snapshot(out: *mut *mut git_config,
+                                          repo: *mut git_repository) -> c_int;
+    pub fn git_repository_discover(out: *mut git_buf,
+                                   start_path: *const c_char,
+                                   across_fs: c_int,
+                                   ceiling_dirs: *const c_char) -> c_int;
+    pub fn git_repository_set_odb(repo: *mut git_repository,
+                                  odb: *mut git_odb);
+
+    pub fn git_repository_refdb(out: *mut *mut git_refdb,
+                                repo: *mut git_repository) -> c_int;
+    pub fn git_repository_set_refdb(repo: *mut git_repository,
+                                    refdb: *mut git_refdb);
+
+    pub fn git_repository_reinit_filesystem(repo: *mut git_repository,
+                                            recurse_submodules: c_int) -> c_int;
+    pub fn git_ignore_add_rule(repo: *mut git_repository,
+                               rules: *const c_char) -> c_int;
+    pub fn git_ignore_clear_internal_rules(repo: *mut git_repository) -> c_int;
+    pub fn git_ignore_path_is_ignored(ignored: *mut c_int,
+                                      repo: *mut git_repository,
+                                      path: *const c_char) -> c_int;
+
+    // revparse
+    pub fn git_revparse(revspec: *mut git_revspec,
+                        repo: *mut git_repository,
+                        spec: *const c_char) -> c_int;
+    pub fn git_revparse_single(out: *mut *mut git_object,
+                               repo: *mut git_repository,
+                               spec: *const c_char) -> c_int;
+    pub fn git_revparse_ext(object_out: *mut *mut git_object,
+                            reference_out: *mut *mut git_reference,
+                            repo: *mut git_repository,
+                            spec: *const c_char) -> c_int;
+
+    // object
+    pub fn git_object_dup(dest: *mut *mut git_object,
+                          source: *mut git_object) -> c_int;
+    pub fn git_object_id(obj: *const git_object) -> *const git_oid;
+    pub fn git_object_free(object: *mut git_object);
+    pub fn git_object_lookup(dest: *mut *mut git_object,
+                             repo: *mut git_repository,
+                             id: *const git_oid,
+                             kind: git_otype) -> c_int;
+    pub fn git_object_type(obj: *const git_object) -> git_otype;
+    pub fn git_object_peel(peeled: *mut *mut git_object,
+                           object: *const git_object,
+                           target_type: git_otype) -> c_int;
+    pub fn git_object_short_id(out: *mut git_buf,
+                               obj: *const git_object) -> c_int;
+    pub fn git_object_type2string(kind: git_otype) -> *const c_char;
+    pub fn git_object_string2type(s: *const c_char) -> git_otype;
+    pub fn git_object_typeisloose(kind: git_otype) -> c_int;
+
+    // oid
+    pub fn git_oid_fromraw(out: *mut git_oid, raw: *const c_uchar);
+    pub fn git_oid_fromstrn(out: *mut git_oid, str: *const c_char,
+                            len: size_t) -> c_int;
+    pub fn git_oid_tostr(out: *mut c_char, n: size_t,
+                         id: *const git_oid) -> *mut c_char;
+    pub fn git_oid_cmp(a: *const git_oid, b: *const git_oid) -> c_int;
+    pub fn git_oid_equal(a: *const git_oid, b: *const git_oid) -> c_int;
+    pub fn git_oid_streq(id: *const git_oid, str: *const c_char) -> c_int;
+    pub fn git_oid_iszero(id: *const git_oid) -> c_int;
+
+    // giterr
+    pub fn giterr_last() -> *const git_error;
+    pub fn giterr_clear();
+    pub fn giterr_set_str(error_class: c_int, string: *const c_char);
+
+    // remote
+    pub fn git_remote_create(out: *mut *mut git_remote,
+                             repo: *mut git_repository,
+                             name: *const c_char,
+                             url: *const c_char) -> c_int;
+    pub fn git_remote_lookup(out: *mut *mut git_remote,
+                             repo: *mut git_repository,
+                             name: *const c_char) -> c_int;
+    pub fn git_remote_create_anonymous(out: *mut *mut git_remote,
+                                       repo: *mut git_repository,
+                                       url: *const c_char) -> c_int;
+    pub fn git_remote_delete(repo: *mut git_repository,
+                             name: *const c_char) -> c_int;
+    pub fn git_remote_free(remote: *mut git_remote);
+    pub fn git_remote_name(remote: *const git_remote) -> *const c_char;
+    pub fn git_remote_pushurl(remote: *const git_remote) -> *const c_char;
+    pub fn git_remote_refspec_count(remote: *const git_remote) -> size_t;
+    pub fn git_remote_url(remote: *const git_remote) -> *const c_char;
+    pub fn git_remote_connect(remote: *mut git_remote,
+                              dir: git_direction,
+                              callbacks: *const git_remote_callbacks,
+                              proxy_opts: *const git_proxy_options,
+                              custom_headers: *const git_strarray) -> c_int;
+    pub fn git_remote_connected(remote: *const git_remote) -> c_int;
+    pub fn git_remote_disconnect(remote: *mut git_remote);
+    pub fn git_remote_add_fetch(repo: *mut git_repository,
+                                remote: *const c_char,
+                                refspec: *const c_char) -> c_int;
+    pub fn git_remote_add_push(repo: *mut git_repository,
+                               remote: *const c_char,
+                               refspec: *const c_char) -> c_int;
+    pub fn git_remote_download(remote: *mut git_remote,
+                               refspecs: *const git_strarray,
+                               opts: *const git_fetch_options) -> c_int;
+    pub fn git_remote_stop(remote: *mut git_remote);
+    pub fn git_remote_dup(dest: *mut *mut git_remote,
+                          source: *mut git_remote) -> c_int;
+    pub fn git_remote_get_fetch_refspecs(array: *mut git_strarray,
+                                         remote: *const git_remote) -> c_int;
+    pub fn git_remote_get_push_refspecs(array: *mut git_strarray,
+                                         remote: *const git_remote) -> c_int;
+    pub fn git_remote_get_refspec(remote: *const git_remote,
+                                  n: size_t) -> *const git_refspec;
+    pub fn git_remote_is_valid_name(remote_name: *const c_char) -> c_int;
+    pub fn git_remote_list(out: *mut git_strarray,
+                           repo: *mut git_repository) -> c_int;
+    pub fn git_remote_rename(problems: *mut git_strarray,
+                             repo: *mut git_repository,
+                             name: *const c_char,
+                             new_name: *const c_char) -> c_int;
+    pub fn git_remote_fetch(remote: *mut git_remote,
+                            refspecs: *const git_strarray,
+                            opts: *const git_fetch_options,
+                            reflog_message: *const c_char) -> c_int;
+    pub fn git_remote_push(remote: *mut git_remote,
+                           refspecs: *const git_strarray,
+                           opts: *const git_push_options) -> c_int;
+    pub fn git_remote_update_tips(remote: *mut git_remote,
+                                  callbacks: *const git_remote_callbacks,
+                                  update_fetchead: c_int,
+                                  download_tags: git_remote_autotag_option_t,
+                                  reflog_message: *const c_char) -> c_int;
+    pub fn git_remote_set_url(repo: *mut git_repository,
+                              remote: *const c_char,
+                              url: *const c_char) -> c_int;
+    pub fn git_remote_set_pushurl(repo: *mut git_repository,
+                                  remote: *const c_char,
+                                  pushurl: *const c_char) -> c_int;
+    pub fn git_remote_init_callbacks(opts: *mut git_remote_callbacks,
+                                     version: c_uint) -> c_int;
+    pub fn git_fetch_init_options(opts: *mut git_fetch_options,
+                                  version: c_uint) -> c_int;
+    pub fn git_remote_stats(remote: *mut git_remote)
+                            -> *const git_transfer_progress;
+    pub fn git_remote_ls(out: *mut *mut *const git_remote_head,
+                         size: *mut size_t,
+                         remote: *mut git_remote) -> c_int;
+    pub fn git_remote_set_autotag(repo: *mut git_repository,
+                                  remote: *const c_char,
+                                  value: git_remote_autotag_option_t) -> c_int;
+    pub fn git_remote_prune(remote: *mut git_remote,
+                            callbacks: *const git_remote_callbacks) -> c_int;
+
+    // refspec
+    pub fn git_refspec_direction(spec: *const git_refspec) -> git_direction;
+    pub fn git_refspec_dst(spec: *const git_refspec) -> *const c_char;
+    pub fn git_refspec_dst_matches(spec: *const git_refspec,
+                                   refname: *const c_char) -> c_int;
+    pub fn git_refspec_src(spec: *const git_refspec) -> *const c_char;
+    pub fn git_refspec_src_matches(spec: *const git_refspec,
+                                   refname: *const c_char) -> c_int;
+    pub fn git_refspec_force(spec: *const git_refspec) -> c_int;
+    pub fn git_refspec_string(spec: *const git_refspec) -> *const c_char;
+
+    // strarray
+    pub fn git_strarray_free(array: *mut git_strarray);
+
+    // oidarray
+    pub fn git_oidarray_free(array: *mut git_oidarray);
+
+    // signature
+    pub fn git_signature_default(out: *mut *mut git_signature,
+                                 repo: *mut git_repository) -> c_int;
+    pub fn git_signature_free(sig: *mut git_signature);
+    pub fn git_signature_new(out: *mut *mut git_signature,
+                             name: *const c_char,
+                             email: *const c_char,
+                             time: git_time_t,
+                             offset: c_int) -> c_int;
+    pub fn git_signature_now(out: *mut *mut git_signature,
+                             name: *const c_char,
+                             email: *const c_char) -> c_int;
+    pub fn git_signature_dup(dest: *mut *mut git_signature,
+                             sig: *const git_signature) -> c_int;
+
+    // status
+    pub fn git_status_list_new(out: *mut *mut git_status_list,
+                               repo: *mut git_repository,
+                               options: *const git_status_options) -> c_int;
+    pub fn git_status_list_entrycount(list: *mut git_status_list) -> size_t;
+    pub fn git_status_byindex(statuslist: *mut git_status_list,
+                              idx: size_t) -> *const git_status_entry;
+    pub fn git_status_list_free(list: *mut git_status_list);
+    pub fn git_status_init_options(opts: *mut git_status_options,
+                                   version: c_uint) -> c_int;
+    pub fn git_status_file(status_flags: *mut c_uint,
+                           repo: *mut git_repository,
+                           path: *const c_char) -> c_int;
+    pub fn git_status_should_ignore(ignored: *mut c_int,
+                                    repo: *mut git_repository,
+                                    path: *const c_char) -> c_int;
+
+    // clone
+    pub fn git_clone(out: *mut *mut git_repository,
+                     url: *const c_char,
+                     local_path: *const c_char,
+                     options: *const git_clone_options) -> c_int;
+    pub fn git_clone_init_options(opts: *mut git_clone_options,
+                                  version: c_uint) -> c_int;
+
+    // reset
+    pub fn git_reset(repo: *mut git_repository,
+                     target: *const git_object,
+                     reset_type: git_reset_t,
+                     checkout_opts: *const git_checkout_options) -> c_int;
+    pub fn git_reset_default(repo: *mut git_repository,
+                             target: *const git_object,
+                             pathspecs: *const git_strarray) -> c_int;
+
+    // reference
+    pub fn git_reference_cmp(ref1: *const git_reference,
+                             ref2: *const git_reference) -> c_int;
+    pub fn git_reference_delete(r: *mut git_reference) -> c_int;
+    pub fn git_reference_free(r: *mut git_reference);
+    pub fn git_reference_is_branch(r: *const git_reference) -> c_int;
+    pub fn git_reference_is_note(r: *const git_reference) -> c_int;
+    pub fn git_reference_is_remote(r: *const git_reference) -> c_int;
+    pub fn git_reference_is_tag(r: *const git_reference) -> c_int;
+    pub fn git_reference_is_valid_name(name: *const c_char) -> c_int;
+    pub fn git_reference_lookup(out: *mut *mut git_reference,
+                                repo: *mut git_repository,
+                                name: *const c_char) -> c_int;
+    pub fn git_reference_name(r: *const git_reference) -> *const c_char;
+    pub fn git_reference_name_to_id(out: *mut git_oid,
+                                    repo: *mut git_repository,
+                                    name: *const c_char) -> c_int;
+    pub fn git_reference_peel(out: *mut *mut git_object,
+                              r: *mut git_reference,
+                              otype: git_otype) -> c_int;
+    pub fn git_reference_rename(new_ref: *mut *mut git_reference,
+                                r: *mut git_reference,
+                                new_name: *const c_char,
+                                force: c_int,
+                                log_message: *const c_char) -> c_int;
+    pub fn git_reference_resolve(out: *mut *mut git_reference,
+                                 r: *const git_reference) -> c_int;
+    pub fn git_reference_shorthand(r: *const git_reference) -> *const c_char;
+    pub fn git_reference_symbolic_target(r: *const git_reference) -> *const c_char;
+    pub fn git_reference_target(r: *const git_reference) -> *const git_oid;
+    pub fn git_reference_target_peel(r: *const git_reference) -> *const git_oid;
+    pub fn git_reference_set_target(out: *mut *mut git_reference,
+                                    r: *mut git_reference,
+                                    id: *const git_oid,
+                                    log_message: *const c_char) -> c_int;
+    pub fn git_reference_type(r: *const git_reference) -> git_ref_t;
+    pub fn git_reference_iterator_new(out: *mut *mut git_reference_iterator,
+                                      repo: *mut git_repository) -> c_int;
+    pub fn git_reference_iterator_glob_new(out: *mut *mut git_reference_iterator,
+                                           repo: *mut git_repository,
+                                           glob: *const c_char) -> c_int;
+    pub fn git_reference_iterator_free(iter: *mut git_reference_iterator);
+    pub fn git_reference_next(out: *mut *mut git_reference,
+                              iter: *mut git_reference_iterator) -> c_int;
+    pub fn git_reference_next_name(out: *mut *const c_char,
+                                   iter: *mut git_reference_iterator) -> c_int;
+    pub fn git_reference_create(out: *mut *mut git_reference,
+                                repo: *mut git_repository,
+                                name: *const c_char,
+                                id: *const git_oid,
+                                force: c_int,
+                                log_message: *const c_char) -> c_int;
+    pub fn git_reference_symbolic_create(out: *mut *mut git_reference,
+                                         repo: *mut git_repository,
+                                         name: *const c_char,
+                                         target: *const c_char,
+                                         force: c_int,
+                                         log_message: *const c_char) -> c_int;
+    pub fn git_reference_create_matching(out: *mut *mut git_reference,
+                                         repo: *mut git_repository,
+                                         name: *const c_char,
+                                         id: *const git_oid,
+                                         force: c_int,
+                                         current_id: *const git_oid,
+                                         log_message: *const c_char) -> c_int;
+    pub fn git_reference_symbolic_create_matching(out: *mut *mut git_reference,
+                                                  repo: *mut git_repository,
+                                                  name: *const c_char,
+                                                  target: *const c_char,
+                                                  force: c_int,
+                                                  current_id: *const c_char,
+                                                  log_message: *const c_char)
+                                                  -> c_int;
+    pub fn git_reference_has_log(repo: *mut git_repository,
+                                 name: *const c_char) -> c_int;
+    pub fn git_reference_ensure_log(repo: *mut git_repository,
+                                    name: *const c_char) -> c_int;
+
+    // stash
+    pub fn git_stash_save(out: *mut git_oid,
+                          repo: *mut git_repository,
+                          stasher: *const git_signature,
+                          message: *const c_char,
+                          flags: c_uint) -> c_int;
+
+    pub fn git_stash_apply_init_options(opts: *mut git_stash_apply_options,
+                                        version: c_uint) -> c_int;
+
+    pub fn git_stash_apply(repo: *mut git_repository,
+                           index: size_t,
+                           options: *const git_stash_apply_options) -> c_int;
+
+    pub fn git_stash_foreach(repo: *mut git_repository,
+                             callback: git_stash_cb,
+                             payload: *mut c_void) -> c_int;
+
+    pub fn git_stash_drop(repo: *mut git_repository,
+                          index: size_t) -> c_int;
+
+    pub fn git_stash_pop(repo: *mut git_repository,
+                         index: size_t,
+                         options: *const git_stash_apply_options) -> c_int;
+
+    // submodules
+    pub fn git_submodule_add_finalize(submodule: *mut git_submodule) -> c_int;
+    pub fn git_submodule_add_setup(submodule: *mut *mut git_submodule,
+                                   repo: *mut git_repository,
+                                   url: *const c_char,
+                                   path: *const c_char,
+                                   use_gitlink: c_int) -> c_int;
+    pub fn git_submodule_add_to_index(submodule: *mut git_submodule,
+                                      write_index: c_int) -> c_int;
+    pub fn git_submodule_branch(submodule: *mut git_submodule) -> *const c_char;
+    pub fn git_submodule_foreach(repo: *mut git_repository,
+                                 callback: git_submodule_cb,
+                                 payload: *mut c_void) -> c_int;
+    pub fn git_submodule_free(submodule: *mut git_submodule);
+    pub fn git_submodule_head_id(submodule: *mut git_submodule) -> *const git_oid;
+    pub fn git_submodule_index_id(submodule: *mut git_submodule) -> *const git_oid;
+    pub fn git_submodule_init(submodule: *mut git_submodule,
+                              overwrite: c_int) -> c_int;
+    pub fn git_submodule_location(status: *mut c_uint,
+                                  submodule: *mut git_submodule) -> c_int;
+    pub fn git_submodule_lookup(out: *mut *mut git_submodule,
+                                repo: *mut git_repository,
+                                name: *const c_char) -> c_int;
+    pub fn git_submodule_name(submodule: *mut git_submodule) -> *const c_char;
+    pub fn git_submodule_open(repo: *mut *mut git_repository,
+                              submodule: *mut git_submodule) -> c_int;
+    pub fn git_submodule_path(submodule: *mut git_submodule) -> *const c_char;
+    pub fn git_submodule_reload(submodule: *mut git_submodule,
+                                force: c_int) -> c_int;
+    pub fn git_submodule_set_ignore(repo: *mut git_repository,
+                                    name: *const c_char,
+                                    ignore: git_submodule_ignore_t)
+                                    -> c_int;
+    pub fn git_submodule_set_update(repo: *mut git_repository,
+                                    name: *const c_char,
+                                    update: git_submodule_update_t)
+                                    -> c_int;
+    pub fn git_submodule_set_url(repo: *mut git_repository,
+                                 name: *const c_char,
+                                 url: *const c_char) -> c_int;
+    pub fn git_submodule_sync(submodule: *mut git_submodule) -> c_int;
+    pub fn git_submodule_update_strategy(submodule: *mut git_submodule)
+                                         -> git_submodule_update_t;
+    pub fn git_submodule_update(submodule: *mut git_submodule,
+                                init: c_int,
+                                options: *mut git_submodule_update_options)
+                                -> c_int;
+    pub fn git_submodule_update_init_options(options: *mut git_submodule_update_options,
+                                             version: c_uint) -> c_int;
+    pub fn git_submodule_url(submodule: *mut git_submodule) -> *const c_char;
+    pub fn git_submodule_wd_id(submodule: *mut git_submodule) -> *const git_oid;
+    pub fn git_submodule_status(status: *mut c_uint,
+                                repo: *mut git_repository,
+                                name: *const c_char,
+                                ignore: git_submodule_ignore_t) -> c_int;
+    pub fn git_submodule_set_branch(repo: *mut git_repository,
+                                    name: *const c_char,
+                                    branch: *const c_char) -> c_int;
+
+    // blob
+    pub fn git_blob_free(blob: *mut git_blob);
+    pub fn git_blob_id(blob: *const git_blob) -> *const git_oid;
+    pub fn git_blob_is_binary(blob: *const git_blob) -> c_int;
+    pub fn git_blob_lookup(blob: *mut *mut git_blob, repo: *mut git_repository,
+                           id: *const git_oid) -> c_int;
+    pub fn git_blob_lookup_prefix(blob: *mut *mut git_blob,
+                                  repo: *mut git_repository,
+                                  id: *const git_oid,
+                                  len: size_t) -> c_int;
+    pub fn git_blob_rawcontent(blob: *const git_blob) -> *const c_void;
+    pub fn git_blob_rawsize(blob: *const git_blob) -> git_off_t;
+    pub fn git_blob_create_frombuffer(id: *mut git_oid,
+                                      repo: *mut git_repository,
+                                      buffer: *const c_void,
+                                      len: size_t) -> c_int;
+    pub fn git_blob_create_fromdisk(id: *mut git_oid,
+                                    repo: *mut git_repository,
+                                    path: *const c_char) -> c_int;
+    pub fn git_blob_create_fromworkdir(id: *mut git_oid,
+                                       repo: *mut git_repository,
+                                       relative_path: *const c_char) -> c_int;
+    pub fn git_blob_create_fromstream(out: *mut *mut git_writestream,
+                                      repo: *mut git_repository,
+                                      hintpath: *const c_char) -> c_int;
+    pub fn git_blob_create_fromstream_commit(id: *mut git_oid,
+                                             stream: *mut git_writestream) -> c_int;
+
+    // tree
+    pub fn git_tree_entry_byid(tree: *const git_tree,
+                               id: *const git_oid) -> *const git_tree_entry;
+    pub fn git_tree_entry_byindex(tree: *const git_tree,
+                                  idx: size_t) -> *const git_tree_entry;
+    pub fn git_tree_entry_byname(tree: *const git_tree,
+                                 filename: *const c_char) -> *const git_tree_entry;
+    pub fn git_tree_entry_bypath(out: *mut *mut git_tree_entry,
+                                 tree: *const git_tree,
+                                 filename: *const c_char) -> c_int;
+    pub fn git_tree_entry_cmp(e1: *const git_tree_entry,
+                              e2: *const git_tree_entry) -> c_int;
+    pub fn git_tree_entry_dup(dest: *mut *mut git_tree_entry,
+                              src: *const git_tree_entry) -> c_int;
+    pub fn git_tree_entry_filemode(entry: *const git_tree_entry) -> git_filemode_t;
+    pub fn git_tree_entry_filemode_raw(entry: *const git_tree_entry) -> git_filemode_t;
+    pub fn git_tree_entry_free(entry: *mut git_tree_entry);
+    pub fn git_tree_entry_id(entry: *const git_tree_entry) -> *const git_oid;
+    pub fn git_tree_entry_name(entry: *const git_tree_entry) -> *const c_char;
+    pub fn git_tree_entry_to_object(out: *mut *mut git_object,
+                                    repo: *mut git_repository,
+                                    entry: *const git_tree_entry) -> c_int;
+    pub fn git_tree_entry_type(entry: *const git_tree_entry) -> git_otype;
+    pub fn git_tree_entrycount(tree: *const git_tree) -> size_t;
+    pub fn git_tree_free(tree: *mut git_tree);
+    pub fn git_tree_id(tree: *const git_tree) -> *const git_oid;
+    pub fn git_tree_lookup(tree: *mut *mut git_tree,
+                           repo: *mut git_repository,
+                           id: *const git_oid) -> c_int;
+    pub fn git_tree_walk(tree: *const git_tree,
+                         mode: git_treewalk_mode,
+                         callback: git_treewalk_cb,
+                         payload: *mut c_void) -> c_int;
+
+    // treebuilder
+    pub fn git_treebuilder_new(out: *mut *mut git_treebuilder,
+                               repo: *mut git_repository,
+                               source: *const git_tree) -> c_int;
+    pub fn git_treebuilder_clear(bld: *mut git_treebuilder);
+    pub fn git_treebuilder_entrycount(bld: *mut git_treebuilder) -> c_uint;
+    pub fn git_treebuilder_free(bld: *mut git_treebuilder);
+    pub fn git_treebuilder_get(bld: *mut git_treebuilder,
+                               filename: *const c_char) -> *const git_tree_entry;
+    pub fn git_treebuilder_insert(out: *mut *const git_tree_entry,
+                                  bld: *mut git_treebuilder,
+                                  filename: *const c_char,
+                                  id: *const git_oid,
+                                  filemode: git_filemode_t) -> c_int;
+    pub fn git_treebuilder_remove(bld: *mut git_treebuilder,
+                                  filename: *const c_char) -> c_int;
+    pub fn git_treebuilder_filter(bld: *mut git_treebuilder,
+                                  filter: git_treebuilder_filter_cb,
+                                  payload: *mut c_void);
+    pub fn git_treebuilder_write(id: *mut git_oid,
+                                 bld: *mut git_treebuilder) -> c_int;
+
+    // buf
+    pub fn git_buf_free(buffer: *mut git_buf);
+    pub fn git_buf_grow(buffer: *mut git_buf, target_size: size_t) -> c_int;
+    pub fn git_buf_set(buffer: *mut git_buf, data: *const c_void,
+                       datalen: size_t) -> c_int;
+
+    // commit
+    pub fn git_commit_author(commit: *const git_commit) -> *const git_signature;
+    pub fn git_commit_committer(commit: *const git_commit) -> *const git_signature;
+    pub fn git_commit_free(commit: *mut git_commit);
+    pub fn git_commit_id(commit: *const git_commit) -> *const git_oid;
+    pub fn git_commit_lookup(commit: *mut *mut git_commit,
+                             repo: *mut git_repository,
+                             id: *const git_oid) -> c_int;
+    pub fn git_commit_message(commit: *const git_commit) -> *const c_char;
+    pub fn git_commit_message_encoding(commit: *const git_commit) -> *const c_char;
+    pub fn git_commit_message_raw(commit: *const git_commit) -> *const c_char;
+    pub fn git_commit_nth_gen_ancestor(commit: *mut *mut git_commit,
+                                       commit: *const git_commit,
+                                       n: c_uint) -> c_int;
+    pub fn git_commit_parent(out: *mut *mut git_commit,
+                             commit: *const git_commit,
+                             n: c_uint) -> c_int;
+    pub fn git_commit_parent_id(commit: *const git_commit,
+                                n: c_uint) -> *const git_oid;
+    pub fn git_commit_parentcount(commit: *const git_commit) -> c_uint;
+    pub fn git_commit_raw_header(commit: *const git_commit) -> *const c_char;
+    pub fn git_commit_summary(commit: *mut git_commit) -> *const c_char;
+    pub fn git_commit_time(commit: *const git_commit) -> git_time_t;
+    pub fn git_commit_time_offset(commit: *const git_commit) -> c_int;
+    pub fn git_commit_tree(tree_out: *mut *mut git_tree,
+                           commit: *const git_commit) -> c_int;
+    pub fn git_commit_tree_id(commit: *const git_commit) -> *const git_oid;
+    pub fn git_commit_amend(id: *mut git_oid,
+                            commit_to_amend: *const git_commit,
+                            update_ref: *const c_char,
+                            author: *const git_signature,
+                            committer: *const git_signature,
+                            message_encoding: *const c_char,
+                            message: *const c_char,
+                            tree: *const git_tree) -> c_int;
+    pub fn git_commit_create(id: *mut git_oid,
+                             repo: *mut git_repository,
+                             update_ref: *const c_char,
+                             author: *const git_signature,
+                             committer: *const git_signature,
+                             message_encoding: *const c_char,
+                             message: *const c_char,
+                             tree: *const git_tree,
+                             parent_count: size_t,
+                             parents: *mut *const git_commit) -> c_int;
+    pub fn git_commit_header_field(out: *mut git_buf,
+                                   commit: *const git_commit,
+                                   field: *const c_char) -> c_int;
+    pub fn git_annotated_commit_lookup(out: *mut *mut git_annotated_commit,
+                                       repo: *mut git_repository,
+                                       id: *const git_oid) -> c_int;
+    pub fn git_commit_create_with_signature(id: *mut git_oid,
+                                            repo: *mut git_repository,
+                                            commit_content: *const c_char,
+                                            signature: *const c_char,
+                                            signature_field: *const c_char) -> c_int;
+    pub fn git_commit_extract_signature(signature: *mut git_buf,
+                                        signed_data: *mut git_buf,
+                                        repo: *mut git_repository,
+                                        commit_id: *mut git_oid,
+                                        field: *const c_char) -> c_int;
+
+    // branch
+    pub fn git_branch_create(out: *mut *mut git_reference,
+                             repo: *mut git_repository,
+                             branch_name: *const c_char,
+                             target: *const git_commit,
+                             force: c_int) -> c_int;
+    pub fn git_branch_delete(branch: *mut git_reference) -> c_int;
+    pub fn git_branch_is_head(branch: *const git_reference) -> c_int;
+    pub fn git_branch_iterator_free(iter: *mut git_branch_iterator);
+    pub fn git_branch_iterator_new(iter: *mut *mut git_branch_iterator,
+                                   repo: *mut git_repository,
+                                   list_flags: git_branch_t) -> c_int;
+    pub fn git_branch_lookup(out: *mut *mut git_reference,
+                             repo: *mut git_repository,
+                             branch_name: *const c_char,
+                             branch_type: git_branch_t) -> c_int;
+    pub fn git_branch_move(out: *mut *mut git_reference,
+                           branch: *mut git_reference,
+                           new_branch_name: *const c_char,
+                           force: c_int) -> c_int;
+    pub fn git_branch_name(out: *mut *const c_char,
+                           branch: *const git_reference) -> c_int;
+    pub fn git_branch_next(out: *mut *mut git_reference,
+                           out_type: *mut git_branch_t,
+                           iter: *mut git_branch_iterator) -> c_int;
+    pub fn git_branch_set_upstream(branch: *mut git_reference,
+                                   upstream_name: *const c_char) -> c_int;
+    pub fn git_branch_upstream(out: *mut *mut git_reference,
+                               branch: *const git_reference) -> c_int;
+
+    // index
+    pub fn git_index_add(index: *mut git_index,
+                         entry: *const git_index_entry) -> c_int;
+    pub fn git_index_add_all(index: *mut git_index,
+                             pathspec: *const git_strarray,
+                             flags: c_uint,
+                             callback: Option<git_index_matched_path_cb>,
+                             payload: *mut c_void) -> c_int;
+    pub fn git_index_add_bypath(index: *mut git_index,
+                                path: *const c_char) -> c_int;
+    pub fn git_index_add_frombuffer(index: *mut git_index,
+                                    entry: *const git_index_entry,
+                                    buffer: *const c_void,
+                                    len: size_t) -> c_int;
+    pub fn git_index_conflict_add(index: *mut git_index,
+                                  ancestor_entry: *const git_index_entry,
+                                  our_entry: *const git_index_entry,
+                                  their_entry: *const git_index_entry) -> c_int;
+    pub fn git_index_clear(index: *mut git_index) -> c_int;
+    pub fn git_index_entry_stage(entry: *const git_index_entry) -> c_int;
+    pub fn git_index_entrycount(entry: *const git_index) -> size_t;
+    pub fn git_index_find(at_pos: *mut size_t,
+                          index: *mut git_index,
+                          path: *const c_char) -> c_int;
+    pub fn git_index_free(index: *mut git_index);
+    pub fn git_index_get_byindex(index: *mut git_index,
+                                 n: size_t) -> *const git_index_entry;
+    pub fn git_index_get_bypath(index: *mut git_index,
+                                path: *const c_char,
+                                stage: c_int) -> *const git_index_entry;
+    pub fn git_index_has_conflicts(index: *const git_index) -> c_int;
+    pub fn git_index_new(index: *mut *mut git_index) -> c_int;
+    pub fn git_index_open(index: *mut *mut git_index,
+                          index_path: *const c_char) -> c_int;
+    pub fn git_index_path(index: *const git_index) -> *const c_char;
+    pub fn git_index_read(index: *mut git_index, force: c_int) -> c_int;
+    pub fn git_index_read_tree(index: *mut git_index,
+                               tree: *const git_tree) -> c_int;
+    pub fn git_index_remove(index: *mut git_index,
+                            path: *const c_char,
+                            stage: c_int) -> c_int;
+    pub fn git_index_remove_all(index: *mut git_index,
+                                pathspec: *const git_strarray,
+                                callback: Option<git_index_matched_path_cb>,
+                                payload: *mut c_void) -> c_int;
+    pub fn git_index_remove_bypath(index: *mut git_index,
+                                   path: *const c_char) -> c_int;
+    pub fn git_index_remove_directory(index: *mut git_index,
+                                      dir: *const c_char,
+                                      stage: c_int) -> c_int;
+    pub fn git_index_update_all(index: *mut git_index,
+                                pathspec: *const git_strarray,
+                                callback: Option<git_index_matched_path_cb>,
+                                payload: *mut c_void) -> c_int;
+    pub fn git_index_write(index: *mut git_index) -> c_int;
+    pub fn git_index_write_tree(out: *mut git_oid,
+                                index: *mut git_index) -> c_int;
+    pub fn git_index_write_tree_to(out: *mut git_oid,
+                                   index: *mut git_index,
+                                   repo: *mut git_repository) -> c_int;
+
+    // config
+    pub fn git_config_add_file_ondisk(cfg: *mut git_config,
+                                      path: *const c_char,
+                                      level: git_config_level_t,
+                                      repo: *const git_repository,
+                                      force: c_int) -> c_int;
+    pub fn git_config_delete_entry(cfg: *mut git_config,
+                                   name: *const c_char) -> c_int;
+    pub fn git_config_delete_multivar(cfg: *mut git_config,
+                                      name: *const c_char,
+                                      regexp: *const c_char) -> c_int;
+    pub fn git_config_find_programdata(out: *mut git_buf) -> c_int;
+    pub fn git_config_find_global(out: *mut git_buf) -> c_int;
+    pub fn git_config_find_system(out: *mut git_buf) -> c_int;
+    pub fn git_config_find_xdg(out: *mut git_buf) -> c_int;
+    pub fn git_config_free(cfg: *mut git_config);
+    pub fn git_config_get_bool(out: *mut c_int,
+                               cfg: *const git_config,
+                               name: *const c_char) -> c_int;
+    pub fn git_config_get_entry(out: *mut *mut git_config_entry,
+                                cfg: *const git_config,
+                                name: *const c_char) -> c_int;
+    pub fn git_config_get_int32(out: *mut i32,
+                                cfg: *const git_config,
+                                name: *const c_char) -> c_int;
+    pub fn git_config_get_int64(out: *mut i64,
+                                cfg: *const git_config,
+                                name: *const c_char) -> c_int;
+    pub fn git_config_get_string(out: *mut *const c_char,
+                                 cfg: *const git_config,
+                                 name: *const c_char) -> c_int;
+    pub fn git_config_get_string_buf(out: *mut git_buf,
+                                     cfg: *const git_config,
+                                     name: *const c_char) -> c_int;
+    pub fn git_config_get_path(out: *mut git_buf,
+                               cfg: *const git_config,
+                               name: *const c_char) -> c_int;
+    pub fn git_config_iterator_free(iter: *mut git_config_iterator);
+    pub fn git_config_iterator_glob_new(out: *mut *mut git_config_iterator,
+                                        cfg: *const git_config,
+                                        regexp: *const c_char) -> c_int;
+    pub fn git_config_iterator_new(out: *mut *mut git_config_iterator,
+                                   cfg: *const git_config) -> c_int;
+    pub fn git_config_new(out: *mut *mut git_config) -> c_int;
+    pub fn git_config_next(entry: *mut *mut git_config_entry,
+                           iter: *mut git_config_iterator) -> c_int;
+    pub fn git_config_open_default(out: *mut *mut git_config) -> c_int;
+    pub fn git_config_open_global(out: *mut *mut git_config,
+                                  config: *mut git_config) -> c_int;
+    pub fn git_config_open_level(out: *mut *mut git_config,
+                                 parent: *const git_config,
+                                 level: git_config_level_t) -> c_int;
+    pub fn git_config_open_ondisk(out: *mut *mut git_config,
+                                  path: *const c_char) -> c_int;
+    pub fn git_config_parse_bool(out: *mut c_int,
+                                 value: *const c_char) -> c_int;
+    pub fn git_config_parse_int32(out: *mut i32,
+                                  value: *const c_char) -> c_int;
+    pub fn git_config_parse_int64(out: *mut i64,
+                                  value: *const c_char) -> c_int;
+    pub fn git_config_set_bool(cfg: *mut git_config,
+                               name: *const c_char,
+                               value: c_int) -> c_int;
+    pub fn git_config_set_int32(cfg: *mut git_config,
+                                name: *const c_char,
+                                value: i32) -> c_int;
+    pub fn git_config_set_int64(cfg: *mut git_config,
+                                name: *const c_char,
+                                value: i64) -> c_int;
+    pub fn git_config_set_multivar(cfg: *mut git_config,
+                                   name: *const c_char,
+                                   regexp: *const c_char,
+                                   value: *const c_char) -> c_int;
+    pub fn git_config_set_string(cfg: *mut git_config,
+                                 name: *const c_char,
+                                 value: *const c_char) -> c_int;
+    pub fn git_config_snapshot(out: *mut *mut git_config,
+                               config: *mut git_config) -> c_int;
+    pub fn git_config_entry_free(entry: *mut git_config_entry);
+
+    // cred
+    pub fn git_cred_default_new(out: *mut *mut git_cred) -> c_int;
+    pub fn git_cred_has_username(cred: *mut git_cred) -> c_int;
+    pub fn git_cred_ssh_custom_new(out: *mut *mut git_cred,
+                                   username: *const c_char,
+                                   publickey: *const c_char,
+                                   publickey_len: size_t,
+                                   sign_callback: git_cred_sign_callback,
+                                   payload: *mut c_void) -> c_int;
+    pub fn git_cred_ssh_interactive_new(out: *mut *mut git_cred,
+                                        username: *const c_char,
+                                        prompt_callback: git_cred_ssh_interactive_callback,
+                                        payload: *mut c_void) -> c_int;
+    pub fn git_cred_ssh_key_from_agent(out: *mut *mut git_cred,
+                                       username: *const c_char) -> c_int;
+    pub fn git_cred_ssh_key_new(out: *mut *mut git_cred,
+                                username: *const c_char,
+                                publickey: *const c_char,
+                                privatekey: *const c_char,
+                                passphrase: *const c_char) -> c_int;
+    pub fn git_cred_ssh_key_memory_new(out: *mut *mut git_cred,
+                                       username: *const c_char,
+                                       publickey: *const c_char,
+                                       privatekey: *const c_char,
+                                       passphrase: *const c_char) -> c_int;
+    pub fn git_cred_userpass(cred: *mut *mut git_cred,
+                             url: *const c_char,
+                             user_from_url: *const c_char,
+                             allowed_types: c_uint,
+                             payload: *mut c_void) -> c_int;
+    pub fn git_cred_userpass_plaintext_new(out: *mut *mut git_cred,
+                                           username: *const c_char,
+                                           password: *const c_char) -> c_int;
+    pub fn git_cred_username_new(cred: *mut *mut git_cred,
+                                 username: *const c_char) -> c_int;
+
+    // tags
+    pub fn git_tag_annotation_create(oid: *mut git_oid,
+                                     repo: *mut git_repository,
+                                     tag_name: *const c_char,
+                                     target: *const git_object,
+                                     tagger: *const git_signature,
+                                     message: *const c_char) -> c_int;
+    pub fn git_tag_create(oid: *mut git_oid,
+                          repo: *mut git_repository,
+                          tag_name: *const c_char,
+                          target: *const git_object,
+                          tagger: *const git_signature,
+                          message: *const c_char,
+                          force: c_int) -> c_int;
+    pub fn git_tag_create_frombuffer(oid: *mut git_oid,
+                                     repo: *mut git_repository,
+                                     buffer: *const c_char,
+                                     force: c_int) -> c_int;
+    pub fn git_tag_create_lightweight(oid: *mut git_oid,
+                                      repo: *mut git_repository,
+                                      tag_name: *const c_char,
+                                      target: *const git_object,
+                                      force: c_int) -> c_int;
+    pub fn git_tag_delete(repo: *mut git_repository,
+                          tag_name: *const c_char) -> c_int;
+    pub fn git_tag_foreach(repo: *mut git_repository,
+                           callback: git_tag_foreach_cb,
+                           payload: *mut c_void) -> c_int;
+    pub fn git_tag_free(tag: *mut git_tag);
+    pub fn git_tag_id(tag: *const git_tag) -> *const git_oid;
+    pub fn git_tag_list(tag_names: *mut git_strarray,
+                        repo: *mut git_repository) -> c_int;
+    pub fn git_tag_list_match(tag_names: *mut git_strarray,
+                              pattern: *const c_char,
+                              repo: *mut git_repository) -> c_int;
+    pub fn git_tag_lookup(out: *mut *mut git_tag,
+                          repo: *mut git_repository,
+                          id: *const git_oid) -> c_int;
+    pub fn git_tag_lookup_prefix(out: *mut *mut git_tag,
+                                 repo: *mut git_repository,
+                                 id: *const git_oid,
+                                 len: size_t) -> c_int;
+    pub fn git_tag_message(tag: *const git_tag) -> *const c_char;
+    pub fn git_tag_name(tag: *const git_tag) -> *const c_char;
+    pub fn git_tag_peel(tag_target_out: *mut *mut git_object,
+                        tag: *const git_tag) -> c_int;
+    pub fn git_tag_tagger(tag: *const git_tag) -> *const git_signature;
+    pub fn git_tag_target(target_out: *mut *mut git_object,
+                          tag: *const git_tag) -> c_int;
+    pub fn git_tag_target_id(tag: *const git_tag) -> *const git_oid;
+    pub fn git_tag_target_type(tag: *const git_tag) -> git_otype;
+
+    // checkout
+    pub fn git_checkout_head(repo: *mut git_repository,
+                             opts: *const git_checkout_options) -> c_int;
+    pub fn git_checkout_index(repo: *mut git_repository,
+                              index: *mut git_index,
+                              opts: *const git_checkout_options) -> c_int;
+    pub fn git_checkout_tree(repo: *mut git_repository,
+                             treeish: *const git_object,
+                             opts: *const git_checkout_options) -> c_int;
+    pub fn git_checkout_init_options(opts: *mut git_checkout_options,
+                                     version: c_uint) -> c_int;
+
+    // merge
+    pub fn git_annotated_commit_id(commit: *const git_annotated_commit)
+                                   -> *const git_oid;
+    pub fn git_annotated_commit_from_ref(out: *mut *mut git_annotated_commit,
+                                         repo: *mut git_repository,
+                                         reference: *const git_reference)
+                                         -> c_int;
+    pub fn git_annotated_commit_free(commit: *mut git_annotated_commit);
+    pub fn git_merge_init_options(opts: *mut git_merge_options,
+                                  version: c_uint) -> c_int;
+    pub fn git_merge(repo: *mut git_repository,
+                     their_heads: *mut *const git_annotated_commit,
+                     len: size_t,
+                     merge_opts: *const git_merge_options,
+                     checkout_opts: *const git_checkout_options) -> c_int;
+    pub fn git_merge_commits(out: *mut *mut git_index,
+                             repo: *mut git_repository,
+                             our_commit: *const git_commit,
+                             their_commit: *const git_commit,
+                             opts: *const git_merge_options) -> c_int;
+    pub fn git_merge_trees(out: *mut *mut git_index,
+                           repo: *mut git_repository,
+                           ancestor_tree: *const git_tree,
+                           our_tree: *const git_tree,
+                           their_tree: *const git_tree,
+                           opts: *const git_merge_options) -> c_int;
+    pub fn git_repository_state_cleanup(repo: *mut git_repository) -> c_int;
+
+    // merge analysis
+
+    pub fn git_merge_analysis(analysis_out: *mut git_merge_analysis_t,
+                              pref_out: *mut git_merge_preference_t,
+                              repo: *mut git_repository,
+                              their_heads: *mut *const git_annotated_commit,
+                              their_heads_len: usize) -> c_int;
+
+    // notes
+    pub fn git_note_author(note: *const git_note) -> *const git_signature;
+    pub fn git_note_committer(note: *const git_note) -> *const git_signature;
+    pub fn git_note_create(out: *mut git_oid,
+                           repo: *mut git_repository,
+                           notes_ref: *const c_char,
+                           author: *const git_signature,
+                           committer: *const git_signature,
+                           oid: *const git_oid,
+                           note: *const c_char,
+                           force: c_int) -> c_int;
+    pub fn git_note_default_ref(out: *mut git_buf,
+                                repo: *mut git_repository) -> c_int;
+    pub fn git_note_free(note: *mut git_note);
+    pub fn git_note_id(note: *const git_note) -> *const git_oid;
+    pub fn git_note_iterator_free(it: *mut git_note_iterator);
+    pub fn git_note_iterator_new(out: *mut *mut git_note_iterator,
+                                 repo: *mut git_repository,
+                                 notes_ref: *const c_char) -> c_int;
+    pub fn git_note_message(note: *const git_note) -> *const c_char;
+    pub fn git_note_next(note_id: *mut git_oid,
+                         annotated_id: *mut git_oid,
+                         it: *mut git_note_iterator) -> c_int;
+    pub fn git_note_read(out: *mut *mut git_note,
+                         repo: *mut git_repository,
+                         notes_ref: *const c_char,
+                         oid: *const git_oid) -> c_int;
+    pub fn git_note_remove(repo: *mut git_repository,
+                           notes_ref: *const c_char,
+                           author: *const git_signature,
+                           committer: *const git_signature,
+                           oid: *const git_oid) -> c_int;
+
+    // blame
+    pub fn git_blame_file(out: *mut *mut git_blame,
+                          repo: *mut git_repository,
+                          path: *const c_char,
+                          options: *mut git_blame_options) -> c_int;
+    pub fn git_blame_free(blame: *mut git_blame);
+
+    pub fn git_blame_init_options(opts: *mut git_blame_options,
+                                  version: c_uint) -> c_int;
+    pub fn git_blame_get_hunk_count(blame: *mut git_blame) -> u32;
+
+    pub fn git_blame_get_hunk_byline(blame: *mut git_blame,
+                                     lineno: usize) -> *const git_blame_hunk;
+    pub fn git_blame_get_hunk_byindex(blame: *mut git_blame,
+                                      index: u32) -> *const git_blame_hunk;
+
+    // revwalk
+    pub fn git_revwalk_new(out: *mut *mut git_revwalk,
+                           repo: *mut git_repository) -> c_int;
+    pub fn git_revwalk_free(walk: *mut git_revwalk);
+
+    pub fn git_revwalk_reset(walk: *mut git_revwalk);
+
+    pub fn git_revwalk_sorting(walk: *mut git_revwalk, sort_mode: c_uint);
+
+    pub fn git_revwalk_push_head(walk: *mut git_revwalk) -> c_int;
+    pub fn git_revwalk_push(walk: *mut git_revwalk,
+                            oid: *const git_oid) -> c_int;
+    pub fn git_revwalk_push_ref(walk: *mut git_revwalk,
+                                refname: *const c_char) -> c_int;
+    pub fn git_revwalk_push_glob(walk: *mut git_revwalk,
+                                 glob: *const c_char) -> c_int;
+    pub fn git_revwalk_push_range(walk: *mut git_revwalk,
+                                  range: *const c_char) -> c_int;
+    pub fn git_revwalk_simplify_first_parent(walk: *mut git_revwalk);
+
+    pub fn git_revwalk_hide_head(walk: *mut git_revwalk) -> c_int;
+    pub fn git_revwalk_hide(walk: *mut git_revwalk,
+                            oid: *const git_oid) -> c_int;
+    pub fn git_revwalk_hide_ref(walk: *mut git_revwalk,
+                                refname: *const c_char) -> c_int;
+    pub fn git_revwalk_hide_glob(walk: *mut git_revwalk,
+                                 refname: *const c_char) -> c_int;
+    pub fn git_revwalk_add_hide_cb(walk: *mut git_revwalk,
+                                   hide_cb: git_revwalk_hide_cb,
+                                   payload: *mut c_void) -> c_int;
+
+    pub fn git_revwalk_next(out: *mut git_oid, walk: *mut git_revwalk) -> c_int;
+
+    // merge
+    pub fn git_merge_base(out: *mut git_oid,
+                          repo: *mut git_repository,
+                          one: *const git_oid,
+                          two: *const git_oid) -> c_int;
+
+    pub fn git_merge_bases(out: *mut git_oidarray,
+                           repo: *mut git_repository,
+                           one: *const git_oid,
+                           two: *const git_oid) -> c_int;
+
+    // pathspec
+    pub fn git_pathspec_free(ps: *mut git_pathspec);
+    pub fn git_pathspec_match_diff(out: *mut *mut git_pathspec_match_list,
+                                   diff: *mut git_diff,
+                                   flags: u32,
+                                   ps: *mut git_pathspec) -> c_int;
+    pub fn git_pathspec_match_index(out: *mut *mut git_pathspec_match_list,
+                                    index: *mut git_index,
+                                    flags: u32,
+                                    ps: *mut git_pathspec) -> c_int;
+    pub fn git_pathspec_match_list_diff_entry(m: *const git_pathspec_match_list,
+                                              pos: size_t) -> *const git_diff_delta;
+    pub fn git_pathspec_match_list_entry(m: *const git_pathspec_match_list,
+                                         pos: size_t) -> *const c_char;
+    pub fn git_pathspec_match_list_entrycount(m: *const git_pathspec_match_list)
+                                              -> size_t;
+    pub fn git_pathspec_match_list_failed_entry(m: *const git_pathspec_match_list,
+                                                pos: size_t) -> *const c_char;
+    pub fn git_pathspec_match_list_failed_entrycount(
+                    m: *const git_pathspec_match_list) -> size_t;
+    pub fn git_pathspec_match_list_free(m: *mut git_pathspec_match_list);
+    pub fn git_pathspec_match_tree(out: *mut *mut git_pathspec_match_list,
+                                   tree: *mut git_tree,
+                                   flags: u32,
+                                   ps: *mut git_pathspec) -> c_int;
+    pub fn git_pathspec_match_workdir(out: *mut *mut git_pathspec_match_list,
+                                      repo: *mut git_repository,
+                                      flags: u32,
+                                      ps: *mut git_pathspec) -> c_int;
+    pub fn git_pathspec_matches_path(ps: *const git_pathspec,
+                                     flags: u32,
+                                     path: *const c_char) -> c_int;
+    pub fn git_pathspec_new(out: *mut *mut git_pathspec,
+                            pathspec: *const git_strarray) -> c_int;
+
+    // diff
+    pub fn git_diff_blob_to_buffer(old_blob: *const git_blob,
+                                   old_as_path: *const c_char,
+                                   buffer: *const c_char,
+                                   buffer_len: size_t,
+                                   buffer_as_path: *const c_char,
+                                   options: *const git_diff_options,
+                                   file_cb: git_diff_file_cb,
+                                   binary_cb: git_diff_binary_cb,
+                                   hunk_cb: git_diff_hunk_cb,
+                                   line_cb: git_diff_line_cb,
+                                   payload: *mut c_void) -> c_int;
+    pub fn git_diff_blobs(old_blob: *const git_blob,
+                          old_as_path: *const c_char,
+                          new_blob: *const git_blob,
+                          new_as_path: *const c_char,
+                          options: *const git_diff_options,
+                          file_cb: git_diff_file_cb,
+                          binary_cb: git_diff_binary_cb,
+                          hunk_cb: git_diff_hunk_cb,
+                          line_cb: git_diff_line_cb,
+                          payload: *mut c_void) -> c_int;
+    pub fn git_diff_buffers(old_buffer: *const c_void,
+                            old_len: size_t,
+                            old_as_path: *const c_char,
+                            new_buffer: *const c_void,
+                            new_len: size_t,
+                            new_as_path: *const c_char,
+                            options: *const git_diff_options,
+                            file_cb: git_diff_file_cb,
+                            binary_cb: git_diff_binary_cb,
+                            hunk_cb: git_diff_hunk_cb,
+                            line_cb: git_diff_line_cb,
+                            payload: *mut c_void) -> c_int;
+    pub fn git_diff_find_similar(diff: *mut git_diff,
+                                 options: *const git_diff_find_options) -> c_int;
+    pub fn git_diff_find_init_options(opts: *mut git_diff_find_options,
+                                      version: c_uint) -> c_int;
+    pub fn git_diff_foreach(diff: *mut git_diff,
+                            file_cb: git_diff_file_cb,
+                            binary_cb: Option<git_diff_binary_cb>,
+                            hunk_cb: Option<git_diff_hunk_cb>,
+                            line_cb: Option<git_diff_line_cb>,
+                            payload: *mut c_void) -> c_int;
+    pub fn git_diff_free(diff: *mut git_diff);
+    pub fn git_diff_get_delta(diff: *const git_diff,
+                              idx: size_t) -> *const git_diff_delta;
+    pub fn git_diff_get_stats(out: *mut *mut git_diff_stats,
+                              diff: *mut git_diff) -> c_int;
+    pub fn git_diff_index_to_index(diff: *mut *mut git_diff,
+                                   repo: *mut git_repository,
+                                   old_index: *mut git_index,
+                                   new_index: *mut git_index,
+                                   opts: *const git_diff_options) -> c_int;
+    pub fn git_diff_index_to_workdir(diff: *mut *mut git_diff,
+                                     repo: *mut git_repository,
+                                     index: *mut git_index,
+                                     opts: *const git_diff_options) -> c_int;
+    pub fn git_diff_init_options(opts: *mut git_diff_options,
+                                 version: c_uint) -> c_int;
+    pub fn git_diff_is_sorted_icase(diff: *const git_diff) -> c_int;
+    pub fn git_diff_merge(onto: *mut git_diff,
+                          from: *const git_diff) -> c_int;
+    pub fn git_diff_num_deltas(diff: *const git_diff) -> size_t;
+    pub fn git_diff_num_deltas_of_type(diff: *const git_diff,
+                                       delta: git_delta_t) -> size_t;
+    pub fn git_diff_print(diff: *mut git_diff,
+                          format: git_diff_format_t,
+                          print_cb: git_diff_line_cb,
+                          payload: *mut c_void) -> c_int;
+    pub fn git_diff_stats_deletions(stats: *const git_diff_stats) -> size_t;
+    pub fn git_diff_stats_files_changed(stats: *const git_diff_stats) -> size_t;
+    pub fn git_diff_stats_free(stats: *mut git_diff_stats);
+    pub fn git_diff_stats_insertions(stats: *const git_diff_stats) -> size_t;
+    pub fn git_diff_stats_to_buf(out: *mut git_buf,
+                                 stats: *const git_diff_stats,
+                                 format: git_diff_stats_format_t,
+                                 width: size_t) -> c_int;
+    pub fn git_diff_status_char(status: git_delta_t) -> c_char;
+    pub fn git_diff_tree_to_index(diff: *mut *mut git_diff,
+                                  repo: *mut git_repository,
+                                  old_tree: *mut git_tree,
+                                  index: *mut git_index,
+                                  opts: *const git_diff_options) -> c_int;
+    pub fn git_diff_tree_to_tree(diff: *mut *mut git_diff,
+                                 repo: *mut git_repository,
+                                 old_tree: *mut git_tree,
+                                 new_tree: *mut git_tree,
+                                 opts: *const git_diff_options) -> c_int;
+    pub fn git_diff_tree_to_workdir(diff: *mut *mut git_diff,
+                                    repo: *mut git_repository,
+                                    old_tree: *mut git_tree,
+                                    opts: *const git_diff_options) -> c_int;
+    pub fn git_diff_tree_to_workdir_with_index(diff: *mut *mut git_diff,
+                                               repo: *mut git_repository,
+                                               old_tree: *mut git_tree,
+                                               opts: *const git_diff_options)
+                                               -> c_int;
+
+    pub fn git_graph_ahead_behind(ahead: *mut size_t, behind: *mut size_t,
+                                  repo: *mut git_repository,
+                                  local: *const git_oid, upstream: *const git_oid)
+                                  -> c_int;
+
+    pub fn git_graph_descendant_of(repo: *mut git_repository,
+                                   commit: *const git_oid, ancestor: *const git_oid)
+                                   -> c_int;
+
+    // patch
+    pub fn git_patch_from_diff(out: *mut *mut git_patch,
+                               diff: *mut git_diff,
+                               idx: size_t) -> c_int;
+    pub fn git_patch_from_blobs(out: *mut *mut git_patch,
+                                old_blob: *const git_blob,
+                                old_as_path: *const c_char,
+                                new_blob: *const git_blob,
+                                new_as_path: *const c_char,
+                                opts: *const git_diff_options) -> c_int;
+    pub fn git_patch_from_blob_and_buffer(out: *mut *mut git_patch,
+                                          old_blob: *const git_blob,
+                                          old_as_path: *const c_char,
+                                          buffer: *const c_void,
+                                          buffer_len: size_t,
+                                          buffer_as_path: *const c_char,
+                                          opts: *const git_diff_options) -> c_int;
+    pub fn git_patch_from_buffers(out: *mut *mut git_patch,
+                                  old_buffer: *const c_void,
+                                  old_len: size_t,
+                                  old_as_path: *const c_char,
+                                  new_buffer: *const c_void,
+                                  new_len: size_t,
+                                  new_as_path: *const c_char,
+                                  opts: *const git_diff_options) -> c_int;
+    pub fn git_patch_free(patch: *mut git_patch);
+    pub fn git_patch_get_delta(patch: *const git_patch) -> *const git_diff_delta;
+    pub fn git_patch_num_hunks(patch: *const git_patch) -> size_t;
+    pub fn git_patch_line_stats(total_context: *mut size_t,
+                                total_additions: *mut size_t,
+                                total_deletions: *mut size_t,
+                                patch: *const git_patch) -> c_int;
+    pub fn git_patch_get_hunk(out: *mut *const git_diff_hunk,
+                              lines_in_hunk: *mut size_t,
+                              patch: *mut git_patch,
+                              hunk_idx: size_t) -> c_int;
+    pub fn git_patch_num_lines_in_hunk(patch: *const git_patch,
+                                       hunk_idx: size_t) -> c_int;
+    pub fn git_patch_get_line_in_hunk(out: *mut *const git_diff_line,
+                                      patch: *mut git_patch,
+                                      hunk_idx: size_t,
+                                      line_of_hunk: size_t) -> c_int;
+    pub fn git_patch_size(patch: *mut git_patch,
+                          include_context: c_int,
+                          include_hunk_headers: c_int,
+                          include_file_headers: c_int) -> size_t;
+    pub fn git_patch_print(patch: *mut git_patch,
+                           print_cb: git_diff_line_cb,
+                           payload: *mut c_void) -> c_int;
+    pub fn git_patch_to_buf(buf: *mut git_buf,
+                            patch: *mut git_patch) -> c_int;
+
+    // reflog
+    pub fn git_reflog_append(reflog: *mut git_reflog,
+                             id: *const git_oid,
+                             committer: *const git_signature,
+                             msg: *const c_char) -> c_int;
+    pub fn git_reflog_delete(repo: *mut git_repository,
+                             name: *const c_char) -> c_int;
+    pub fn git_reflog_drop(reflog: *mut git_reflog,
+                           idx: size_t,
+                           rewrite_previous_entry: c_int) -> c_int;
+    pub fn git_reflog_entry_byindex(reflog: *const git_reflog,
+                                    idx: size_t) -> *const git_reflog_entry;
+    pub fn git_reflog_entry_committer(entry: *const git_reflog_entry)
+                                      -> *const git_signature;
+    pub fn git_reflog_entry_id_new(entry: *const git_reflog_entry)
+                                   -> *const git_oid;
+    pub fn git_reflog_entry_id_old(entry: *const git_reflog_entry)
+                                   -> *const git_oid;
+    pub fn git_reflog_entry_message(entry: *const git_reflog_entry)
+                                    -> *const c_char;
+    pub fn git_reflog_entrycount(reflog: *mut git_reflog) -> size_t;
+    pub fn git_reflog_free(reflog: *mut git_reflog);
+    pub fn git_reflog_read(out: *mut *mut git_reflog,
+                           repo: *mut git_repository,
+                           name: *const c_char) -> c_int;
+    pub fn git_reflog_rename(repo: *mut git_repository,
+                             old_name: *const c_char,
+                             name: *const c_char) -> c_int;
+    pub fn git_reflog_write(reflog: *mut git_reflog) -> c_int;
+
+    // transport
+    pub fn git_transport_register(prefix: *const c_char,
+                                  cb: git_transport_cb,
+                                  param: *mut c_void) -> c_int;
+    pub fn git_transport_unregister(prefix: *const c_char) -> c_int;
+    pub fn git_transport_smart(out: *mut *mut git_transport,
+                               owner: *mut git_remote,
+                               payload: *mut c_void) -> c_int;
+
+    // describe
+    pub fn git_describe_commit(result: *mut *mut git_describe_result,
+                               object: *mut git_object,
+                               opts: *mut git_describe_options) -> c_int;
+    pub fn git_describe_format(buf: *mut git_buf,
+                               result: *const git_describe_result,
+                               opts: *const git_describe_format_options) -> c_int;
+    pub fn git_describe_result_free(result: *mut git_describe_result);
+    pub fn git_describe_workdir(out: *mut *mut git_describe_result,
+                                repo: *mut git_repository,
+                                opts: *mut git_describe_options) -> c_int;
+
+    // message
+    pub fn git_message_prettify(out: *mut git_buf,
+                                message: *const c_char,
+                                strip_comments: c_int,
+                                comment_char: c_char) -> c_int;
+
+    // packbuilder
+    pub fn git_packbuilder_new(out: *mut *mut git_packbuilder,
+                               repo: *mut git_repository) -> c_int;
+    pub fn git_packbuilder_set_threads(pb: *mut git_packbuilder,
+                                       n: c_uint) -> c_uint;
+    pub fn git_packbuilder_insert(pb: *mut git_packbuilder,
+                                  id: *const git_oid,
+                                  name: *const c_char) -> c_int;
+    pub fn git_packbuilder_insert_tree(pb: *mut git_packbuilder,
+                                       id: *const git_oid) -> c_int;
+    pub fn git_packbuilder_insert_commit(pb: *mut git_packbuilder,
+                                         id: *const git_oid) -> c_int;
+    pub fn git_packbuilder_insert_walk(pb: *mut git_packbuilder,
+                                       walk: *mut git_revwalk) -> c_int;
+    pub fn git_packbuilder_insert_recur(pb: *mut git_packbuilder,
+                                        id: *const git_oid,
+                                        name: *const c_char) -> c_int;
+    pub fn git_packbuilder_write_buf(buf: *mut git_buf,
+                                     pb: *mut git_packbuilder) -> c_int;
+    pub fn git_packbuilder_write(pb: *mut git_packbuilder,
+                                 path: *const c_char,
+                                 mode: c_uint,
+                                 progress_cb: Option<git_transfer_progress_cb>,
+                                 progress_cb_payload: *mut c_void) -> c_int;
+    pub fn git_packbuilder_hash(pb: *mut git_packbuilder) -> *const git_oid;
+    pub fn git_packbuilder_foreach(pb: *mut git_packbuilder,
+                                   cb: git_packbuilder_foreach_cb,
+                                   payload: *mut c_void) -> c_int;
+    pub fn git_packbuilder_object_count(pb: *mut git_packbuilder) -> size_t;
+    pub fn git_packbuilder_written(pb: *mut git_packbuilder) -> size_t;
+    pub fn git_packbuilder_set_callbacks(pb: *mut git_packbuilder,
+                                         progress_cb: Option<git_packbuilder_progress>,
+                                         progress_cb_payload: *mut c_void) -> c_int;
+    pub fn git_packbuilder_free(pb: *mut git_packbuilder);
+
+    // odb
+    pub fn git_repository_odb(out: *mut *mut git_odb,
+                              repo: *mut git_repository) -> c_int;
+    pub fn git_odb_new(db: *mut *mut git_odb) -> c_int;
+    pub fn git_odb_free(db: *mut git_odb);
+    pub fn git_odb_open_rstream(out: *mut *mut git_odb_stream,
+                                len: *mut size_t,
+                                otype: *mut git_otype,
+                                db: *mut git_odb,
+                                oid: *const git_oid) -> c_int;
+    pub fn git_odb_stream_read(stream: *mut git_odb_stream,
+                               buffer: *mut c_char,
+                               len: size_t) -> c_int;
+    pub fn git_odb_open_wstream(out: *mut *mut git_odb_stream,
+                                db: *mut git_odb,
+                                size: git_off_t,
+                                obj_type: git_otype) -> c_int;
+    pub fn git_odb_stream_write(stream: *mut git_odb_stream,
+                                buffer: *const c_char,
+                                len: size_t) -> c_int;
+    pub fn git_odb_stream_finalize_write(id: *mut git_oid,
+                                         stream: *mut git_odb_stream) -> c_int;
+    pub fn git_odb_stream_free(stream: *mut git_odb_stream);
+    pub fn git_odb_foreach(db: *mut git_odb, cb: git_odb_foreach_cb, payload: *mut c_void) -> c_int;
+
+    pub fn git_odb_read(out: *mut *mut git_odb_object,
+                        odb: *mut git_odb,
+                        oid: *const git_oid) -> c_int;
+
+    pub fn git_odb_read_header(len_out: *mut size_t,
+                               type_out: *mut git_otype,
+                               odb: *mut git_odb,
+                               oid: *const git_oid) -> c_int;
+
+    pub fn git_odb_write(out: *mut git_oid,
+                         odb: *mut git_odb,
+                         data: *const c_void,
+                         len: size_t,
+                         otype: git_otype) -> c_int;
+
+    pub fn git_odb_hash(out: *mut git_oid,
+                        data: *const c_void,
+                        len: size_t,
+                        otype: git_otype) -> c_int;
+
+    pub fn git_odb_hashfile(out: *mut git_oid,
+                            path: *const c_char,
+                            otype: git_otype) -> c_int;
+
+    pub fn git_odb_exists_prefix(out: *mut git_oid,
+                                 odb: *mut git_odb,
+                                 short_oid: *const git_oid,
+                                 len: size_t) -> c_int;
+
+    pub fn git_odb_exists(odb: *mut git_odb,
+                          oid: *const git_oid) -> c_int;
+
+    pub fn git_odb_refresh(odb: *mut git_odb) -> c_int;
+
+    pub fn git_odb_object_id(obj: *mut git_odb_object) -> *const git_oid;
+    pub fn git_odb_object_size(obj: *mut git_odb_object) -> size_t;
+    pub fn git_odb_object_type(obj: *mut git_odb_object) -> git_otype;
+    pub fn git_odb_object_data(obj: *mut git_odb_object) -> *const c_void;
+    pub fn git_odb_object_dup(out: *mut *mut git_odb_object,
+                              obj: *mut git_odb_object) -> c_int;
+    pub fn git_odb_object_free(obj: *mut git_odb_object);
+
+    pub fn git_odb_init_backend(odb: *mut git_odb_backend,
+                                version: c_uint) -> c_int;
+
+    pub fn git_odb_add_backend(odb: *mut git_odb,
+                               backend: *mut git_odb_backend,
+                               priority: c_int) -> c_int;
+
+    pub fn git_odb_backend_pack(out: *mut *mut git_odb_backend,
+                                objects_dir: *const c_char) -> c_int;
+
+    pub fn git_odb_backend_one_pack(out: *mut *mut git_odb_backend,
+                                objects_dir: *const c_char) -> c_int;
+
+    pub fn git_odb_add_disk_alternate(odb: *mut git_odb,
+                                      path: *const c_char) -> c_int;
+
+    pub fn git_odb_backend_loose(out: *mut *mut git_odb_backend,
+                                 objects_dir: *const c_char,
+                                 compression_level: c_int,
+                                 do_fsync: c_int,
+                                 dir_mode: c_uint,
+                                 file_mode: c_uint) -> c_int;
+
+    pub fn git_odb_add_alternate(odb: *mut git_odb,
+                                 backend: *mut git_odb_backend,
+                                 priority: c_int) -> c_int;
+
+    pub fn git_odb_backend_malloc(backend: *mut git_odb_backend,
+                                  len: size_t) -> *mut c_void;
+
+    pub fn git_odb_num_backends(odb: *mut git_odb) -> size_t;
+    pub fn git_odb_get_backend(backend: *mut *mut git_odb_backend,
+                               odb: *mut git_odb,
+                               position: size_t) -> c_int;
+
+    // mempack
+    pub fn git_mempack_new(out: *mut *mut git_odb_backend) -> c_int;
+    pub fn git_mempack_reset(backend: *mut git_odb_backend);
+    pub fn git_mempack_dump(pack: *mut git_buf,
+                            repo: *mut git_repository,
+                            backend: *mut git_odb_backend) -> c_int;
+
+    // refdb
+    pub fn git_refdb_new(out: *mut *mut git_refdb, repo: *mut git_repository) -> c_int;
+    pub fn git_refdb_open(out: *mut *mut git_refdb, repo: *mut git_repository) -> c_int;
+    pub fn git_refdb_backend_fs(out: *mut *mut git_refdb_backend, repo: *mut git_repository) -> c_int;
+    pub fn git_refdb_init_backend(backend: *mut git_refdb_backend, version: c_uint) -> c_int;
+    pub fn git_refdb_set_backend(refdb: *mut git_refdb, backend: *mut git_refdb_backend) -> c_int;
+    pub fn git_refdb_compress(refdb: *mut git_refdb) -> c_int;
+    pub fn git_refdb_free(refdb: *mut git_refdb);
+
+    // rebase
+    pub fn git_rebase_init_options(opts: *mut git_rebase_options, version: c_uint) -> c_int;
+    pub fn git_rebase_init(out: *mut *mut git_rebase,
+                           repo: *mut git_repository,
+                           branch: *const git_annotated_commit,
+                           upstream: *const git_annotated_commit,
+                           onto: *const git_annotated_commit,
+                           opts: *const git_rebase_options) -> c_int;
+    pub fn git_rebase_open(out: *mut *mut git_rebase, repo: *mut git_repository, opts: *const git_rebase_options) -> c_int;
+    pub fn git_rebase_operation_entrycount(rebase: *mut git_rebase) -> size_t;
+    pub fn git_rebase_operation_current(rebase: *mut git_rebase) -> size_t;
+    pub fn git_rebase_operation_byindex(rebase: *mut git_rebase, idx: size_t) -> *mut git_rebase_operation;
+    pub fn git_rebase_next(operation: *mut *mut git_rebase_operation, rebase: *mut git_rebase) -> c_int;
+    pub fn git_rebase_inmemory_index(index: *mut *mut git_index, rebase: *mut git_rebase) -> c_int;
+    pub fn git_rebase_commit(id: *mut git_oid,
+                             rebase: *mut git_rebase,
+                             author: *const git_signature,
+                             committer: *const git_signature,
+                             message_encoding: *const c_char,
+                             message: *const c_char) -> c_int;
+    pub fn git_rebase_abort(rebase: *mut git_rebase) -> c_int;
+    pub fn git_rebase_finish(rebase: *mut git_rebase, signature: *const git_signature) -> c_int;
+    pub fn git_rebase_free(rebase: *mut git_rebase);
+}
+
+pub fn init() {
+    use std::sync::{Once, ONCE_INIT};
+
+    static INIT: Once = ONCE_INIT;
+    INIT.call_once(|| unsafe {
+        openssl_init();
+        ssh_init();
+        let r = git_libgit2_init();
+        assert!(r >= 0,
+                "couldn't initialize the libgit2 library: {}", r);
+
+        // Note that we intentionally never schedule `git_libgit2_shutdown` to
+        // get called. There's not really a great time to call that and #276 has
+        // some more info about how automatically doing it can cause problems.
+    });
+}
+
+#[cfg(all(unix, feature = "https"))]
+#[doc(hidden)]
+pub fn openssl_init() {
+    openssl_sys::init();
+}
+
+#[cfg(any(windows, not(feature = "https")))]
+#[doc(hidden)]
+pub fn openssl_init() {}
+
+#[cfg(feature = "ssh")]
+fn ssh_init() {
+    libssh2::init();
+}
+
+#[cfg(not(feature = "ssh"))]
+fn ssh_init() {}

vendor/libgit2-sys/libgit2/AUTHORS

diff --git a/vendor/libgit2-sys/libgit2/AUTHORS b/vendor/libgit2-sys/libgit2/AUTHORS
new file mode 100644
index 0000000..458ff06
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/AUTHORS
@@ -0,0 +1,77 @@
+The following people contribute or have contributed
+to the libgit2 project (sorted alphabetically):
+
+Alex Budovski
+Alexei Sholik
+Andreas Ericsson
+Anton "antong" Gyllenberg
+Ankur Sethi
+Arthur Schreiber
+Ben Noordhuis
+Ben Straub
+Benjamin C Meyer
+Brian Downing
+Brian Lopez
+Carlos Martín Nieto
+Colin Timmermans
+Daniel Huckstep
+Dave Borowitz
+David Boyce
+David Glesser
+Dmitry Kakurin
+Dmitry Kovega
+Emeric Fermas
+Emmanuel Rodriguez
+Eric Myhre
+Florian Forster
+Holger Weiss
+Ingmar Vanhassel
+J. David Ibáñez
+Jacques Germishuys
+Jakob Pfender
+Jason Penny
+Jason R. McNeil
+Jerome Lambourg
+Johan 't Hart
+John Wiegley
+Jonathan "Duke" Leto
+Julien Miotte
+Julio Espinoza-Sokal
+Justin Love
+Kelly "kelly.leahy" Leahy
+Kirill A. Shutemov
+Lambert CLARA
+Luc Bertrand
+Marc Pegon
+Marcel Groothuis
+Marco Villegas
+Michael "schu" Schubert
+Microsoft Corporation
+Olivier Ramonat
+Peter Drahoš
+Pierre Habouzit
+Pierre-Olivier Latour
+Przemyslaw Pawelczyk
+Ramsay Jones
+Robert G. Jakabosky
+Romain Geissler
+Romain Muller
+Russell Belfer
+Sakari Jokinen
+Samuel Charles "Sam" Day
+Sarath Lakshman
+Sascha Cunz
+Sascha Peilicke
+Scott Chacon
+Sebastian Schuberth
+Sergey Nikishin
+Shawn O. Pearce
+Shuhei Tanuma
+Steve Frécinaux
+Sven Strickroth
+Tim Branyen
+Tim Clem
+Tim Harder
+Torsten Bögershausen
+Trent Mick
+Vicent Marti

vendor/libgit2-sys/libgit2/CHANGELOG.md

diff --git a/vendor/libgit2-sys/libgit2/CHANGELOG.md b/vendor/libgit2-sys/libgit2/CHANGELOG.md
new file mode 100644
index 0000000..bd495d9
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/CHANGELOG.md
@@ -0,0 +1,1028 @@
+v0.27 + 1
+---------
+
+### Changes or improvements
+
+* The line-ending filtering logic - when checking out files - has been
+  updated to match newer git (>= git 2.9) for proper interoperability.
+
+* Submodules with names which attempt to perform path traversal now have their
+  configuration ignored. Such names were blindly appended to the
+  `$GIT_DIR/modules` and a malicious name could lead to an attacker writing to
+  an arbitrary location. This matches git's handling of CVE-2018-11235.
+
+### API additions
+
+### API removals
+
+### Breaking API changes
+
+* The default checkout strategy changed from `DRY_RUN` to `SAFE` (#4531).
+
+* Adding a symlink as .gitmodules into the index from the workdir or checking
+  out such files is not allowed as this can make a Git implementation write
+  outside of the repository and bypass the fsck checks for CVE-2018-11235.
+
+v0.27
+---------
+
+### Changes or improvements
+
+* Improved `p_unlink` in `posix_w32.c` to try and make a file writable
+  before sleeping in the retry loop to prevent unnecessary calls to sleep.
+
+* The CMake build infrastructure has been improved to speed up building time.
+
+* A new CMake option "-DUSE_HTTPS=<backend>" makes it possible to explicitly
+  choose an HTTP backend.
+
+* A new CMake option "-DSHA1_BACKEND=<backend>" makes it possible to explicitly
+  choose an SHA1 backend. The collision-detecting backend is now the default.
+
+* A new CMake option "-DUSE_BUNDLED_ZLIB" makes it possible to explicitly use
+  the bundled zlib library.
+
+* A new CMake option "-DENABLE_REPRODUCIBLE_BUILDS" makes it possible to
+  generate a reproducible static archive. This requires support from your
+  toolchain.
+
+* The minimum required CMake version has been bumped to 2.8.11.
+
+* Writing to a configuration file now preserves the case of the key given by the
+  caller for the case-insensitive portions of the key (existing sections are
+  used even if they don't match).
+
+* We now support conditional includes in configuration files.
+
+* Fix for handling re-reading of configuration files with includes.
+
+* Fix for reading patches which contain exact renames only.
+
+* Fix for reading patches with whitespace in the compared files' paths.
+
+* We will now fill `FETCH_HEAD` from all passed refspecs instead of overwriting
+  with the last one.
+
+* There is a new diff option, `GIT_DIFF_INDENT_HEURISTIC` which activates a
+  heuristic which takes into account whitespace and indentation in order to
+  produce better diffs when dealing with ambiguous diff hunks.
+
+* Fix for pattern-based ignore rules where files ignored by a rule cannot be
+  un-ignored by another rule.
+
+* Sockets opened by libgit2 are now being closed on exec(3) if the platform
+  supports it.
+
+* Fix for peeling annotated tags from packed-refs files.
+
+* Fix reading huge loose objects from the object database.
+
+* Fix files not being treated as modified when only the file mode has changed.
+
+* We now explicitly reject adding submodules to the index via
+  `git_index_add_frombuffer`.
+
+* Fix handling of `GIT_DIFF_FIND_RENAMES_FROM_REWRITES` raising `SIGABRT` when
+  one file has been deleted and another file has been rewritten.
+
+* Fix for WinHTTP not properly handling NTLM and Negotiate challenges.
+
+* When using SSH-based transports, we now repeatedly ask for the passphrase to
+  decrypt the private key in case a wrong passphrase is being provided.
+
+* When generating conflict markers, they will now use the same line endings as
+  the rest of the file.
+
+### API additions
+
+* The `git_merge_file_options` structure now contains a new setting,
+  `marker_size`.  This allows users to set the size of markers that
+  delineate the sides of merged files in the output conflict file.
+  By default this is 7 (`GIT_MERGE_CONFLICT_MARKER_SIZE`), which
+  produces output markers like `<<<<<<<` and `>>>>>>>`.
+
+* `git_remote_create_detached()` creates a remote that is not associated
+  to any repository (and does not apply configuration like 'insteadof' rules).
+  This is mostly useful for e.g. emulating `git ls-remote` behavior.
+
+* `git_diff_patchid()` lets you generate patch IDs for diffs.
+
+* `git_status_options` now has an additional field `baseline` to allow creating
+  status lists against different trees.
+
+* New family of functions to allow creating notes for a specific notes commit
+  instead of for a notes reference.
+
+* New family of functions to allow parsing message trailers. This API is still
+  experimental and may change in future releases.
+
+### API removals
+
+### Breaking API changes
+
+* Signatures now distinguish between +0000 and -0000 UTC offsets.
+
+* The certificate check callback in the WinHTTP transport will now receive the
+  `message_cb_payload` instead of the `cred_acquire_payload`.
+
+* We are now reading symlinked directories under .git/refs.
+
+* We now refuse creating branches named "HEAD".
+
+* We now refuse reading and writing all-zero object IDs into the
+  object database.
+
+* We now read the effective user's configuration file instead of the real user's
+  configuration in case libgit2 runs as part of a setuid binary.
+
+* The `git_odb_open_rstream` function and its `readstream` callback in the
+  `git_odb_backend` interface have changed their signatures to allow providing
+  the object's size and type to the caller.
+
+v0.26
+-----
+
+### Changes or improvements
+
+* Support for opening, creating and modifying worktrees.
+
+* We can now detect SHA1 collisions resulting from the SHAttered attack. These
+  checks can be enabled at build time via `-DUSE_SHA1DC`.
+
+* Fix for missing implementation of `git_merge_driver_source` getters.
+
+* Fix for installed pkg-config file being broken when the prefix contains
+  spaces.
+
+* We now detect when the hashsum of on-disk objects does not match their
+  expected hashsum.
+
+* We now support open-ended ranges (e.g. "master..", "...master") in our
+  revision range parsing code.
+
+* We now correctly compute ignores with leading "/" in subdirectories.
+
+* We now optionally call `fsync` on loose objects, packfiles and their indexes,
+  loose references and packed reference files.
+
+* We can now build against OpenSSL v1.1 and against LibreSSL.
+
+* `GIT_MERGE_OPTIONS_INIT` now includes a setting to perform rename detection.
+  This aligns this structure with the default by `git_merge` and
+  `git_merge_trees` when `NULL` was provided for the options.
+
+* Improvements for reading index v4 files.
+
+* Perform additional retries for filesystem operations on Windows when files
+  are temporarily locked by other processes.
+
+### API additions
+
+* New family of functions to handle worktrees:
+
+    * `git_worktree_list()` lets you look up worktrees for a repository.
+    * `git_worktree_lookup()` lets you get a specific worktree.
+    * `git_worktree_open_from_repository()` lets you get the associated worktree
+      of a repository.
+      a worktree.
+    * `git_worktree_add` lets you create new worktrees.
+    * `git_worktree_prune` lets you remove worktrees from disk.
+    * `git_worktree_lock()` and `git_worktree_unlock()` let you lock
+      respectively unlock a worktree.
+    * `git_repository_open_from_worktree()` lets you open a repository via
+    * `git_repository_head_for_worktree()` lets you get the current `HEAD` for a
+      linked worktree.
+    * `git_repository_head_detached_for_worktree()` lets you check whether a
+      linked worktree is in detached HEAD mode.
+
+* `git_repository_item_path()` lets you retrieve paths for various repository
+  files.
+
+* `git_repository_commondir()` lets you retrieve the common directory of a
+  repository.
+
+* `git_branch_is_checked_out()` allows you to check whether a branch is checked
+  out in a repository or any of its worktrees.
+
+* `git_repository_submodule_cache_all()` and
+  `git_repository_submodule_cache_clear()` functions allow you to prime or clear
+  the submodule cache of a repository.
+
+* You can disable strict hash verifications via the
+  `GIT_OPT_ENABLE_STRICT_HASH_VERIFICATION` option with `git_libgit2_opts()`.
+
+* You can enable us calling `fsync` for various files inside the ".git"
+  directory by setting the `GIT_OPT_ENABLE_FSYNC_GITDIR` option with
+  `git_libgit2_opts()`.
+
+* You can now enable "offset deltas" when creating packfiles and negotiating
+  packfiles with a remote server by setting `GIT_OPT_ENABLE_OFS_DELTA` option
+  with `GIT_libgit2_opts()`.
+
+* You can now set the default share mode on Windows for opening files using
+  `GIT_OPT_SET_WINDOWS_SHAREMODE` option with `git_libgit2_opts()`.
+  You can query the current share mode with `GIT_OPT_GET_WINDOWS_SHAREMODE`.
+
+* `git_transport_smart_proxy_options()' enables you to get the proxy options for
+  smart transports.
+
+* The `GIT_FILTER_INIT` macro and the `git_filter_init` function are provided
+  to initialize a `git_filter` structure.
+
+### Breaking API changes
+
+* `clone_checkout_strategy` has been removed from
+  `git_submodule_update_option`. The checkout strategy used to clone will
+  be the same strategy specified in `checkout_opts`.
+
+v0.25
+-------
+
+### Changes or improvements
+
+* Fix repository discovery with `git_repository_discover` and
+  `git_repository_open_ext` to match git's handling of a ceiling
+  directory at the current directory. git only checks ceiling
+  directories when its search ascends to a parent directory.  A ceiling
+  directory matching the starting directory will not prevent git from
+  finding a repository in the starting directory or a parent directory.
+
+* Do not fail when deleting remotes in the presence of broken
+  global configs which contain branches.
+
+* Support for reading and writing git index v4 files
+
+* Improve the performance of the revwalk and bring us closer to git's code.
+
+* The reference db has improved support for concurrency and returns `GIT_ELOCKED`
+  when an operation could not be performed due to locking.
+
+* Nanosecond resolution is now activated by default, following git's change to
+  do this.
+
+* We now restrict the set of ciphers we let OpenSSL use by default.
+
+* Users can now register their own merge drivers for use with `.gitattributes`.
+  The library also gained built-in support for the union merge driver.
+
+* The default for creating references is now to validate that the object does
+  exist.
+
+* Add `git_proxy_options` which is used by the different networking
+  implementations to let the caller specify the proxy settings instead of
+  relying on the environment variables.
+
+### API additions
+
+* You can now get the user-agent used by libgit2 using the
+  `GIT_OPT_GET_USER_AGENT` option with `git_libgit2_opts()`.
+  It is the counterpart to `GIT_OPT_SET_USER_AGENT`.
+
+* The `GIT_OPT_SET_SSL_CIPHERS` option for `git_libgit2_opts()` lets you specify
+  a custom list of ciphers to use for OpenSSL.
+
+* `git_commit_create_buffer()` creates a commit and writes it into a
+  user-provided buffer instead of writing it into the object db. Combine it with
+  `git_commit_create_with_signature()` in order to create a commit with a
+  cryptographic signature.
+
+* `git_blob_create_fromstream()` and
+  `git_blob_create_fromstream_commit()` allow you to create a blob by
+  writing into a stream. Useful when you do not know the final size or
+  want to copy the contents from another stream.
+
+* New flags for `git_repository_open_ext`:
+
+    * `GIT_REPOSITORY_OPEN_NO_DOTGIT` - Do not check for a repository by
+      appending `/.git` to the `start_path`; only open the repository if
+      `start_path` itself points to the git directory.
+    * `GIT_REPOSITORY_OPEN_FROM_ENV` - Find and open a git repository,
+      respecting the environment variables used by the git command-line
+      tools. If set, `git_repository_open_ext` will ignore the other
+      flags and the `ceiling_dirs` argument, and will allow a NULL
+      `path` to use `GIT_DIR` or search from the current directory. The
+      search for a repository will respect `$GIT_CEILING_DIRECTORIES`
+      and `$GIT_DISCOVERY_ACROSS_FILESYSTEM`.  The opened repository
+      will respect `$GIT_INDEX_FILE`, `$GIT_NAMESPACE`,
+      `$GIT_OBJECT_DIRECTORY`, and `$GIT_ALTERNATE_OBJECT_DIRECTORIES`.
+      In the future, this flag will also cause `git_repository_open_ext`
+      to respect `$GIT_WORK_TREE` and `$GIT_COMMON_DIR`; currently,
+      `git_repository_open_ext` with this flag will error out if either
+      `$GIT_WORK_TREE` or `$GIT_COMMON_DIR` is set.
+
+* `git_diff_from_buffer()` can create a `git_diff` object from the contents
+  of a git-style patch file.
+
+* `git_index_version()` and `git_index_set_version()` to get and set
+  the index version
+
+* `git_odb_expand_ids()` lets you check for the existence of multiple
+  objects at once.
+
+* The new `git_blob_dup()`, `git_commit_dup()`, `git_tag_dup()` and
+  `git_tree_dup()` functions provide type-specific wrappers for
+  `git_object_dup()` to reduce noise and increase type safety for callers.
+
+* `git_reference_dup()` lets you duplicate a reference to aid in ownership
+  management and cleanup.
+
+* `git_signature_from_buffer()` lets you create a signature from a string in the
+  format that appear in objects.
+
+* `git_tree_create_updated()` lets you create a tree based on another one
+  together with a list of updates. For the covered update cases, it's more
+  efficient than the `git_index` route.
+
+* `git_apply_patch()` applies hunks from a `git_patch` to a buffer.
+
+* `git_diff_to_buf()` lets you print an entire diff directory to a buffer,
+  similar to how `git_patch_to_buf()` works.
+
+* `git_proxy_init_options()` is added to initialize a `git_proxy_options`
+  structure at run-time.
+
+* `git_merge_driver_register()`, `git_merge_driver_unregister()` let you
+  register and unregister a custom merge driver to be used when `.gitattributes`
+  specifies it.
+
+* `git_merge_driver_lookup()` can be used to look up a merge driver by name.
+
+* `git_merge_driver_source_repo()`, `git_merge_driver_source_ancestor()`,
+  `git_merge_driver_source_ours()`, `git_merge_driver_source_theirs()`,
+  `git_merge_driver_source_file_options()` added as accessors to
+  `git_merge_driver_source`.
+
+### API removals
+
+* `git_blob_create_fromchunks()` has been removed in favour of
+  `git_blob_create_fromstream()`.
+
+### Breaking API changes
+
+* `git_packbuilder_object_count` and `git_packbuilder_written` now
+  return a `size_t` instead of a `uint32_t` for more thorough
+  compatibility with the rest of the library.
+
+* `git_packbuiler_progress` now provides explicitly sized `uint32_t`
+  values instead of `unsigned int`.
+
+* `git_diff_file` now includes an `id_abbrev` field that reflects the
+  number of nibbles set in the `id` field.
+
+* `git_odb_backend` now has a `freshen` function pointer.  This optional
+  function pointer is similar to the `exists` function, but it will update
+  a last-used marker.  For filesystem-based object databases, this updates
+  the timestamp of the file containing the object, to indicate "freshness".
+  If this is `NULL`, then it will not be called and the `exists` function
+  will be used instead.
+
+* `git_remote_connect()` now accepts `git_proxy_options` argument, and
+  `git_fetch_options` and `git_push_options` each have a `proxy_opts` field.
+
+* `git_merge_options` now provides a `default_driver` that can be used
+  to provide the name of a merge driver to be used to handle files changed
+  during a merge.
+
+v0.24
+-------
+
+### Changes or improvements
+
+* Custom merge drivers can now be registered, which allows callers to
+  configure callbacks to honor `merge=driver` configuration in
+  `.gitattributes`.
+
+* Custom filters can now be registered with wildcard attributes, for
+  example `filter=*`.  Consumers should examine the attributes parameter
+  of the `check` function for details.
+
+* Symlinks are now followed when locking a file, which can be
+  necessary when multiple worktrees share a base repository.
+
+* You can now set your own user-agent to be sent for HTTP requests by
+  using the `GIT_OPT_SET_USER_AGENT` with `git_libgit2_opts()`.
+
+* You can set custom HTTP header fields to be sent along with requests
+  by passing them in the fetch and push options.
+
+* Tree objects are now assumed to be sorted. If a tree is not
+  correctly formed, it will give bad results. This is the git approach
+  and cuts a significant amount of time when reading the trees.
+
+* Filter registration is now protected against concurrent
+  registration.
+
+* Filenames which are not valid on Windows in an index no longer cause
+  to fail to parse it on that OS.
+
+* Rebases can now be performed purely in-memory, without touching the
+  repository's workdir.
+
+* When adding objects to the index, or when creating new tree or commit
+  objects, the inputs are validated to ensure that the dependent objects
+  exist and are of the correct type.  This object validation can be
+  disabled with the GIT_OPT_ENABLE_STRICT_OBJECT_CREATION option.
+
+* The WinHTTP transport's handling of bad credentials now behaves like
+  the others, asking for credentials again.
+
+### API additions
+
+* `git_config_lock()` has been added, which allow for
+  transactional/atomic complex updates to the configuration, removing
+  the opportunity for concurrent operations and not committing any
+  changes until the unlock.
+
+* `git_diff_options` added a new callback `progress_cb` to report on the
+  progress of the diff as files are being compared. The documentation of
+  the existing callback `notify_cb` was updated to reflect that it only
+  gets called when new deltas are added to the diff.
+
+* `git_fetch_options` and `git_push_options` have gained a `custom_headers`
+  field to set the extra HTTP header fields to send.
+
+* `git_stream_register_tls()` lets you register a callback to be used
+  as the constructor for a TLS stream instead of the libgit2 built-in
+  one.
+
+* `git_commit_header_field()` allows you to look up a specific header
+  field in a commit.
+
+* `git_commit_extract_signature()` extracts the signature from a
+  commit and gives you both the signature and the signed data so you
+  can verify it.
+
+### API removals
+
+* No APIs were removed in this version.
+
+### Breaking API changes
+
+* The `git_merge_tree_flag_t` is now `git_merge_flag_t`.  Subsequently,
+  its members are no longer prefixed with `GIT_MERGE_TREE_FLAG` but are
+  now prefixed with `GIT_MERGE_FLAG`, and the `tree_flags` field of the
+  `git_merge_options` structure is now named `flags`.
+
+* The `git_merge_file_flags_t` enum is now `git_merge_file_flag_t` for
+  consistency with other enum type names.
+
+* `git_cert` descendent types now have a proper `parent` member
+
+* It is the responsibility of the refdb backend to decide what to do
+  with the reflog on ref deletion. The file-based backend must delete
+  it, a database-backed one may wish to archive it.
+
+* `git_config_backend` has gained two entries. `lock` and `unlock`
+  with which to implement the transactional/atomic semantics for the
+  configuration backend.
+
+* `git_index_add` and `git_index_conflict_add()` will now use the case
+  as provided by the caller on case insensitive systems.  Previous
+  versions would keep the case as it existed in the index.  This does
+  not affect the higher-level `git_index_add_bypath` or
+  `git_index_add_frombuffer` functions.
+
+* The `notify_payload` field of `git_diff_options` was renamed to `payload`
+  to reflect that it's also the payload for the new progress callback.
+
+* The `git_config_level_t` enum has gained a higher-priority value
+  `GIT_CONFIG_LEVEL_PROGRAMDATA` which represent a rough Windows equivalent
+  to the system level configuration.
+
+* `git_rebase_options` now has a `merge_options` field.
+
+* The index no longer performs locking itself. This is not something
+  users of the library should have been relying on as it's not part of
+  the concurrency guarantees.
+
+* `git_remote_connect()` now takes a `custom_headers` argument to set
+  the extra HTTP header fields to send.
+
+v0.23
+------
+
+### Changes or improvements
+
+* Patience and minimal diff drivers can now be used for merges.
+
+* Merges can now ignore whitespace changes.
+
+* Updated binary identification in CRLF filtering to avoid false positives in
+  UTF-8 files.
+
+* Rename and copy detection is enabled for small files.
+
+* Checkout can now handle an initial checkout of a repository, making
+  `GIT_CHECKOUT_SAFE_CREATE` unnecessary for users of clone.
+
+* The signature parameter in the ref-modifying functions has been
+  removed. Use `git_repository_set_ident()` and
+  `git_repository_ident()` to override the signature to be used.
+
+* The local transport now auto-scales the number of threads to use
+  when creating the packfile instead of sticking to one.
+
+* Reference renaming now uses the right id for the old value.
+
+* The annotated version of branch creation, HEAD detaching and reset
+  allow for specifying the expression from the user to be put into the
+  reflog.
+
+* `git_rebase_commit` now returns `GIT_EUNMERGED` when you attempt to
+  commit with unstaged changes.
+
+* On Mac OS X, we now use SecureTransport to provide the cryptographic
+  support for HTTPS connections insead of OpenSSL.
+
+* Checkout can now accept an index for the baseline computations via the
+  `baseline_index` member.
+
+* The configuration for fetching is no longer stored inside the
+  `git_remote` struct but has been moved to a `git_fetch_options`. The
+  remote functions now take these options or the callbacks instead of
+  setting them beforehand.
+
+* `git_submodule` instances are no longer cached or shared across
+  lookup. Each submodule represents the configuration at the time of
+  loading.
+
+* The index now uses diffs for `add_all()` and `update_all()` which
+  gives it a speed boost and closer semantics to git.
+
+* The ssh transport now reports the stderr output from the server as
+  the error message, which allows you to get the "repository not
+  found" messages.
+
+* `git_index_conflict_add()` will remove staged entries that exist for
+  conflicted paths.
+
+* The flags for a `git_diff_file` will now have the `GIT_DIFF_FLAG_EXISTS`
+  bit set when a file exists on that side of the diff.  This is useful
+  for understanding whether a side of the diff exists in the presence of
+  a conflict.
+
+* The constructor for a write-stream into the odb now takes
+  `git_off_t` instead of `size_t` for the size of the blob, which
+  allows putting large files into the odb on 32-bit systems.
+
+* The remote's push and pull URLs now honor the url.$URL.insteadOf
+  configuration. This allows modifying URL prefixes to a custom
+  value via gitconfig.
+
+* `git_diff_foreach`, `git_diff_blobs`, `git_diff_blob_to_buffer`,
+  and `git_diff_buffers` now accept a new binary callback of type
+  `git_diff_binary_cb` that includes the binary diff information.
+
+* The race condition mitigations described in `racy-git.txt` have been
+  implemented.
+
+* If libcurl is installed, we will use it to connect to HTTP(S)
+  servers.
+
+### API additions
+
+* The `git_merge_options` gained a `file_flags` member.
+
+* Parsing and retrieving a configuration value as a path is exposed
+  via `git_config_parse_path()` and `git_config_get_path()`
+  respectively.
+
+* `git_repository_set_ident()` and `git_repository_ident()` serve to
+  set and query which identity will be used when writing to the
+  reflog.
+
+* `git_config_entry_free()` frees a config entry.
+
+* `git_config_get_string_buf()` provides a way to safely retrieve a
+  string from a non-snapshot configuration.
+
+* `git_annotated_commit_from_revspec()` allows to get an annotated
+  commit from an extended sha synatx string.
+
+* `git_repository_set_head_detached_from_annotated()`,
+  `git_branch_create_from_annotated()` and
+  `git_reset_from_annotated()` allow for the caller to provide an
+  annotated commit through which they can control what expression is
+  put into the reflog as the source/target.
+
+* `git_index_add_frombuffer()` can now create a blob from memory
+  buffer and add it to the index which is attached to a repository.
+
+* The structure `git_fetch_options` has been added to determine the
+  runtime configuration for fetching, such as callbacks, pruning and
+  autotag behaviour. It has the runtime initializer
+  `git_fetch_init_options()`.
+
+* The enum `git_fetch_prune_t` has been added, letting you specify the
+  pruning behaviour for a fetch.
+
+* A push operation will notify the caller of what updates it indends
+  to perform on the remote, which provides similar information to
+  git's pre-push hook.
+
+* `git_stash_apply()` can now apply a stashed state from the stash list,
+  placing the data into the working directory and index.
+
+* `git_stash_pop()` will apply a stashed state (like `git_stash_apply()`)
+  but will remove the stashed state after a successful application.
+
+* A new error code `GIT_EEOF` indicates an early EOF from the
+  server. This typically indicates an error with the URL or
+  configuration of the server, and tools can use this to show messages
+  about failing to communicate with the server.
+
+* A new error code `GIT_EINVALID` indicates that an argument to a
+  function is invalid, or an invalid operation was requested.
+
+* `git_diff_index_to_workdir()` and `git_diff_tree_to_index()` will now
+  produce deltas of type `GIT_DELTA_CONFLICTED` to indicate that the index
+  side of the delta is a conflict.
+
+* The `git_status` family of functions will now produce status of type
+  `GIT_STATUS_CONFLICTED` to indicate that a conflict exists for that file
+  in the index.
+
+* `git_index_entry_is_conflict()` is a utility function to determine if
+  a given index entry has a non-zero stage entry, indicating that it is
+  one side of a conflict.
+
+* It is now possible to pass a keypair via a buffer instead of a
+  path. For this, `GIT_CREDTYPE_SSH_MEMORY` and
+  `git_cred_ssh_key_memory_new()` have been added.
+
+* `git_filter_list_contains` will indicate whether a particular
+  filter will be run in the given filter list.
+
+* `git_commit_header_field()` has been added, which allows retrieving
+  the contents of an arbitrary header field.
+
+* `git_submodule_set_branch()` allows to set the configured branch for
+  a submodule.
+
+### API removals
+
+* `git_remote_save()` and `git_remote_clear_refspecs()` have been
+  removed. Remote's configuration is changed via the configuration
+  directly or through a convenience function which performs changes to
+  the configuration directly.
+
+* `git_remote_set_callbacks()`, `git_remote_get_callbacks()` and
+  `git_remote_set_transport()` have been removed and the remote no
+  longer stores this configuration.
+
+* `git_remote_set_fetch_refpecs()` and
+  `git_remote_set_push_refspecs()` have been removed. There is no
+  longer a way to set the base refspecs at run-time.
+
+* `git_submodule_save()` has been removed. The submodules are no
+  longer configured via the objects.
+
+* `git_submodule_reload_all()` has been removed as we no longer cache
+  submodules.
+
+### Breaking API changes
+
+* `git_smart_subtransport_cb` now has a `param` parameter.
+
+* The `git_merge_options` structure member `flags` has been renamed
+  to `tree_flags`.
+
+* The `git_merge_file_options` structure member `flags` is now
+  an unsigned int. It was previously a `git_merge_file_flags_t`.
+
+* `GIT_CHECKOUT_SAFE_CREATE` has been removed.  Most users will generally
+  be able to switch to `GIT_CHECKOUT_SAFE`, but if you require missing
+  file handling during checkout, you may now use `GIT_CHECKOUT_SAFE |
+  GIT_CHECKOUT_RECREATE_MISSING`.
+
+* The `git_clone_options` and `git_submodule_update_options`
+  structures no longer have a `signature` field.
+
+* The following functions have removed the signature and/or log message
+  parameters in favour of git-emulating ones.
+
+    * `git_branch_create()`, `git_branch_move()`
+    * `git_rebase_init()`, `git_rebase_abort()`
+    * `git_reference_symbolic_create_matching()`,
+      `git_reference_symbolic_create()`, `git_reference_create()`,
+      `git_reference_create_matching()`,
+      `git_reference_symbolic_set_target()`,
+      `git_reference_set_target()`, `git_reference_rename()`
+    * `git_remote_update_tips()`, `git_remote_fetch()`, `git_remote_push()`
+    * `git_repository_set_head()`,
+      `git_repository_set_head_detached()`,
+      `git_repository_detach_head()`
+    * `git_reset()`
+
+* `git_config_get_entry()` now gives back a ref-counted
+  `git_config_entry`. You must free it when you no longer need it.
+
+* `git_config_get_string()` will return an error if used on a
+  non-snapshot configuration, as there can be no guarantee that the
+  returned pointer is valid.
+
+* `git_note_default_ref()` now uses a `git_buf` to return the string,
+  as the string is otherwise not guaranteed to stay allocated.
+
+* `git_rebase_operation_current()` will return `GIT_REBASE_NO_OPERATION`
+  if it is called immediately after creating a rebase session but before
+  you have applied the first patch.
+
+* `git_rebase_options` now contains a `git_checkout_options` struct
+  that will be used for functions that modify the working directory,
+  namely `git_rebase_init`, `git_rebase_next` and
+  `git_rebase_abort`.  As a result, `git_rebase_open` now also takes
+  a `git_rebase_options` and only the `git_rebase_init` and
+  `git_rebase_open` functions take a `git_rebase_options`, where they
+  will persist the options to subsequent `git_rebase` calls.
+
+* The `git_clone_options` struct now has fetch options in a
+  `fetch_opts` field instead of remote callbacks in
+  `remote_callbacks`.
+
+* The remote callbacks has gained a new member `push_negotiation`
+  which gets called before sending the update commands to the server.
+
+* The following functions no longer act on a remote instance but
+  change the repository's configuration. Their signatures have changed
+  accordingly:
+
+    * `git_remote_set_url()`, `git_remote_seturl()`
+    * `git_remote_add_fetch()`, `git_remote_add_push()` and
+    * `git_remote_set_autotag()`
+
+* `git_remote_connect()` and `git_remote_prune()` now take a pointer
+  to the callbacks.
+
+* `git_remote_fetch()` and `git_remote_download()` now take a pointer
+  to fetch options which determine the runtime configuration.
+
+* The `git_remote_autotag_option_t` values have been changed. It has
+  gained a `_UNSPECIFIED` default value to specify no override for the
+  configured setting.
+
+* `git_remote_update_tips()` now takes a pointer to the callbacks as
+  well as a boolean whether to write `FETCH_HEAD` and the autotag
+  setting.
+
+* `git_remote_create_anonymous()` no longer takes a fetch refspec as
+  url-only remotes cannot have configured refspecs.
+
+* The `git_submodule_update_options` struct now has fetch options in
+  the `fetch_opts` field instead of callbacks in the
+  `remote_callbacks` field.
+
+* The following functions no longer act on a submodule instance but
+  change the repository's configuration. Their signatures have changed
+  accordingly:
+
+    * `git_submodule_set_url()`, `git_submodule_set_ignore()`,
+      `git_submodule_set_update()`,
+      `git_submodule_set_fetch_recurse_submodules()`.
+
+* `git_submodule_status()` no longer takes a submodule instance but a
+  repsitory, a submodule name and an ignore setting.
+
+* The `push` function in the `git_transport` interface now takes a
+  pointer to the remote callbacks.
+
+* The `git_index_entry` struct's fields' types have been changed to
+  more accurately reflect what is in fact stored in the
+  index. Specifically, time and file size are 32 bits intead of 64, as
+  these values are truncated.
+
+* `GIT_EMERGECONFLICT` is now `GIT_ECONFLICT`, which more accurately
+  describes the nature of the error.
+
+* It is no longer allowed to call `git_buf_grow()` on buffers
+  borrowing the memory they point to.
+
+v0.22
+------
+
+### Changes or improvements
+
+* `git_signature_new()` now requires a non-empty email address.
+
+* Use CommonCrypto libraries for SHA-1 calculation on Mac OS X.
+
+* Disable SSL compression and SSLv2 and SSLv3 ciphers in favor of TLSv1
+  in OpenSSL.
+
+* The fetch behavior of remotes with autotag set to `GIT_REMOTE_DOWNLOAD_TAGS_ALL`
+  has been changed to match git 1.9.0 and later. In this mode, libgit2 now
+  fetches all tags in addition to whatever else needs to be fetched.
+
+* `git_checkout()` now handles case-changing renames correctly on
+  case-insensitive filesystems; for example renaming "readme" to "README".
+
+* The search for libssh2 is now done via pkg-config instead of a
+  custom search of a few directories.
+
+* Add support for core.protectHFS and core.protectNTFS. Add more
+  validation for filenames which we write such as references.
+
+* The local transport now generates textual progress output like
+  git-upload-pack does ("counting objects").
+
+* `git_checkout_index()` can now check out an in-memory index that is not
+  necessarily the repository's index, so you may check out an index
+  that was produced by git_merge and friends while retaining the cached
+  information.
+
+* Remove the default timeout for receiving / sending data over HTTP using
+  the WinHTTP transport layer.
+
+* Add SPNEGO (Kerberos) authentication using GSSAPI on Unix systems.
+
+* Provide built-in objects for the empty blob (e69de29) and empty
+  tree (4b825dc) objects.
+
+* The index' tree cache is now filled upon read-tree and write-tree
+  and the cache is written to disk.
+
+* LF -> CRLF filter refuses to handle mixed-EOL files
+
+* LF -> CRLF filter now runs when * text = auto (with Git for Windows 1.9.4)
+
+* File unlocks are atomic again via rename. Read-only files on Windows are
+  made read-write if necessary.
+
+* Share open packfiles across repositories to share descriptors and mmaps.
+
+* Use a map for the treebuilder, making insertion O(1)
+
+* The build system now accepts an option EMBED_SSH_PATH which when set
+  tells it to include a copy of libssh2 at the given location. This is
+  enabled for MSVC.
+
+* Add support for refspecs with the asterisk in the middle of a
+  pattern.
+
+* Fetching now performs opportunistic updates. To achieve this, we
+  introduce a difference between active and passive refspecs, which
+  make `git_remote_download()` and `git_remote_fetch()` to take a list of
+  resfpecs to be the active list, similarly to how git fetch accepts a
+  list on the command-line.
+
+* The THREADSAFE option to build libgit2 with threading support has
+  been flipped to be on by default.
+
+* The remote object has learnt to prune remote-tracking branches. If
+  the remote is configured to do so, this will happen via
+  `git_remote_fetch()`. You can also call `git_remote_prune()` after
+  connecting or fetching to perform the prune.
+
+
+### API additions
+
+* Introduce `git_buf_text_is_binary()` and `git_buf_text_contains_nul()` for
+  consumers to perform binary detection on a git_buf.
+
+* `git_branch_upstream_remote()` has been introduced to provide the
+  branch.<name>.remote configuration value.
+
+* Introduce `git_describe_commit()` and `git_describe_workdir()` to provide
+  a description of the current commit (and working tree, respectively)
+  based on the nearest tag or reference
+
+* Introduce `git_merge_bases()` and the `git_oidarray` type to expose all
+  merge bases between two commits.
+
+* Introduce `git_merge_bases_many()` to expose all merge bases between
+  multiple commits.
+
+* Introduce rebase functionality (using the merge algorithm only).
+  Introduce `git_rebase_init()` to begin a new rebase session,
+  `git_rebase_open()` to open an in-progress rebase session,
+  `git_rebase_commit()` to commit the current rebase operation,
+  `git_rebase_next()` to apply the next rebase operation,
+  `git_rebase_abort()` to abort an in-progress rebase and `git_rebase_finish()`
+  to complete a rebase operation.
+
+* Introduce `git_note_author()` and `git_note_committer()` to get the author
+  and committer information on a `git_note`, respectively.
+
+* A factory function for ssh has been added which allows to change the
+  path of the programs to execute for receive-pack and upload-pack on
+  the server, `git_transport_ssh_with_paths()`.
+
+* The ssh transport supports asking the remote host for accepted
+  credential types as well as multiple challeges using a single
+  connection. This requires to know which username you want to connect
+  as, so this introduces the USERNAME credential type which the ssh
+  transport will use to ask for the username.
+
+* The `GIT_EPEEL` error code has been introduced when we cannot peel a tag
+  to the requested object type; if the given object otherwise cannot be
+  peeled, `GIT_EINVALIDSPEC` is returned.
+
+* Introduce `GIT_REPOSITORY_INIT_RELATIVE_GITLINK` to use relative paths
+  when writing gitlinks, as is used by git core for submodules.
+
+* `git_remote_prune()` has been added. See above for description.
+
+
+* Introduce reference transactions, which allow multiple references to
+  be locked at the same time and updates be queued. This also allows
+  us to safely update a reflog with arbitrary contents, as we need to
+  do for stash.
+
+### API removals
+
+* `git_remote_supported_url()` and `git_remote_is_valid_url()` have been
+  removed as they have become essentially useless with rsync-style ssh paths.
+
+* `git_clone_into()` and `git_clone_local_into()` have been removed from the
+  public API in favour of `git_clone callbacks`.
+
+* The option to ignore certificate errors via `git_remote_cert_check()`
+  is no longer present. Instead, `git_remote_callbacks` has gained a new
+  entry which lets the user perform their own certificate checks.
+
+### Breaking API changes
+
+* `git_cherry_pick()` is now `git_cherrypick()`.
+
+* The `git_submodule_update()` function was renamed to
+  `git_submodule_update_strategy()`. `git_submodule_update()` is now used to
+  provide functionalty similar to "git submodule update".
+
+* `git_treebuilder_create()` was renamed to `git_treebuilder_new()` to better
+  reflect it being a constructor rather than something which writes to
+  disk.
+
+* `git_treebuilder_new()` (was `git_treebuilder_create()`) now takes a
+  repository so that it can query repository configuration.
+  Subsequently, `git_treebuilder_write()` no longer takes a repository.
+
+* `git_threads_init()` and `git_threads_shutdown()` have been renamed to
+  `git_libgit2_init()` and `git_libgit2_shutdown()` to better explain what
+  their purpose is, as it's grown to be more than just about threads.
+
+* `git_libgit2_init()` and `git_libgit2_shutdown()` now return the number of
+  initializations of the library, so consumers may schedule work on the
+  first initialization.
+
+* The `git_transport_register()` function no longer takes a priority and takes
+  a URL scheme name (eg "http") instead of a prefix like "http://"
+
+* `git_index_name_entrycount()` and `git_index_reuc_entrycount()` now
+  return size_t instead of unsigned int.
+
+* The `context_lines` and `interhunk_lines` fields in `git_diff`_options are
+  now `uint32_t` instead of `uint16_t`. This allows to set them to `UINT_MAX`,
+  in effect asking for "infinite" context e.g. to iterate over all the
+  unmodified lines of a diff.
+
+* `git_status_file()` now takes an exact path. Use `git_status_list_new()` if
+  pathspec searching is needed.
+
+* `git_note_create()` has changed the position of the notes reference
+  name to match `git_note_remove()`.
+
+* Rename `git_remote_load()` to `git_remote_lookup()` to bring it in line
+  with the rest of the lookup functions.
+
+* `git_remote_rename()` now takes the repository and the remote's
+  current name. Accepting a remote indicates we want to change it,
+  which we only did partially. It is much clearer if we accept a name
+  and no loaded objects are changed.
+
+* `git_remote_delete()` now accepts the repository and the remote's name
+  instead of a loaded remote.
+
+* `git_merge_head` is now `git_annotated_commit`, to better reflect its usage
+  for multiple functions (including rebase)
+
+* The `git_clone_options` struct no longer provides the `ignore_cert_errors` or
+  `remote_name` members for remote customization.
+
+  Instead, the `git_clone_options` struct has two new members, `remote_cb` and
+  `remote_cb_payload`, which allow the caller to completely override the remote
+  creation process. If needed, the caller can use this callback to give their
+  remote a name other than the default (origin) or disable cert checking.
+
+  The `remote_callbacks` member has been preserved for convenience, although it
+  is not used when a remote creation callback is supplied.
+
+* The `git_clone`_options struct now provides `repository_cb` and
+  `repository_cb_payload` to allow the user to create a repository with
+  custom options.
+
+* The `git_push` struct to perform a push has been replaced with
+  `git_remote_upload()`. The refspecs and options are passed as a
+  function argument. `git_push_update_tips()` is now also
+  `git_remote_update_tips()` and the callbacks are in the same struct as
+  the rest.
+
+* The `git_remote_set_transport()` function now sets a transport factory function,
+  rather than a pre-existing transport instance.
+
+* The `git_transport` structure definition has moved into the sys/transport.h
+  file.
+
+* libgit2 no longer automatically sets the OpenSSL locking
+  functions. This is not something which we can know to do. A
+  last-resort convenience function is provided in sys/openssl.h,
+  `git_openssl_set_locking()` which can be used to set the locking.

vendor/libgit2-sys/libgit2/CMakeLists.txt

diff --git a/vendor/libgit2-sys/libgit2/CMakeLists.txt b/vendor/libgit2-sys/libgit2/CMakeLists.txt
new file mode 100644
index 0000000..d411751
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/CMakeLists.txt
@@ -0,0 +1,291 @@
+# CMake build script for the libgit2 project
+#
+# Building (out of source build):
+# > mkdir build && cd build
+# > cmake .. [-DSETTINGS=VALUE]
+# > cmake --build .
+#
+# Testing:
+# > ctest -V
+#
+# Install:
+# > cmake --build . --target install
+
+PROJECT(libgit2 C)
+CMAKE_MINIMUM_REQUIRED(VERSION 2.8.11)
+CMAKE_POLICY(SET CMP0015 NEW)
+IF (POLICY CMP0051)
+	CMAKE_POLICY(SET CMP0051 NEW)
+ENDIF()
+IF (POLICY CMP0042)
+	CMAKE_POLICY(SET CMP0042 NEW)
+ENDIF()
+
+# Add find modules to the path
+SET(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${libgit2_SOURCE_DIR}/cmake/Modules/")
+
+INCLUDE(CheckLibraryExists)
+INCLUDE(CheckFunctionExists)
+INCLUDE(CheckSymbolExists)
+INCLUDE(CheckStructHasMember)
+INCLUDE(AddCFlagIfSupported)
+INCLUDE(FindPkgLibraries)
+INCLUDE(FindThreads)
+INCLUDE(FindStatNsec)
+INCLUDE(IdeSplitSources)
+INCLUDE(FeatureSummary)
+INCLUDE(EnableWarnings)
+
+# Build options
+#
+OPTION( SONAME				"Set the (SO)VERSION of the target"		ON  )
+OPTION( BUILD_SHARED_LIBS	"Build Shared Library (OFF for Static)"	ON  )
+OPTION( THREADSAFE			"Build libgit2 as threadsafe"			ON )
+OPTION( BUILD_CLAR			"Build Tests using the Clar suite"		ON  )
+OPTION( BUILD_EXAMPLES		"Build library usage example apps"		OFF )
+OPTION( TAGS				"Generate tags"							OFF )
+OPTION( PROFILE				"Generate profiling information"		OFF )
+OPTION( ENABLE_TRACE		"Enables tracing support"				OFF )
+OPTION( LIBGIT2_FILENAME	"Name of the produced binary"			OFF )
+
+SET(SHA1_BACKEND "CollisionDetection" CACHE STRING "Backend to use for SHA1. One of Generic, OpenSSL, Win32, CommonCrypto, mbedTLS, CollisionDetection. ")
+OPTION( USE_SSH				"Link with libssh to enable SSH support" ON )
+OPTION( USE_HTTPS			"Enable HTTPS support. Can be set to a specific backend"	ON )
+OPTION( USE_GSSAPI			"Link with libgssapi for SPNEGO auth"   OFF )
+OPTION( VALGRIND			"Configure build for valgrind"			OFF )
+OPTION( CURL			"Use curl for HTTP if available" ON)
+OPTION( USE_EXT_HTTP_PARSER		"Use system HTTP_Parser if available" ON)
+OPTION( DEBUG_POOL			"Enable debug pool allocator"			OFF )
+OPTION( ENABLE_WERROR			"Enable compilation with -Werror"		OFF )
+OPTION( USE_BUNDLED_ZLIB    "Use the bundled version of zlib"       OFF )
+
+IF (UNIX AND NOT APPLE)
+	OPTION( ENABLE_REPRODUCIBLE_BUILDS	"Enable reproducible builds" 			OFF )
+ENDIF()
+
+IF (APPLE)
+	OPTION( USE_ICONV			"Link with and use iconv library"		 ON )
+ENDIF()
+
+IF(MSVC)
+	# This option is only available when building with MSVC. By default, libgit2
+	# is build using the cdecl calling convention, which is useful if you're
+	# writing C. However, the CLR and Win32 API both expect stdcall.
+	#
+	# If you are writing a CLR program and want to link to libgit2, you'll want
+	# to turn this on by invoking CMake with the "-DSTDCALL=ON" argument.
+	OPTION( STDCALL			"Build libgit2 with the __stdcall convention"	OFF  )
+
+	# This option must match the settings used in your program, in particular if you
+	# are linking statically
+	OPTION( STATIC_CRT		"Link the static CRT libraries"	ON  )
+
+	# If you want to embed a copy of libssh2 into libgit2, pass a
+	# path to libssh2
+	OPTION( EMBED_SSH_PATH		"Path to libssh2 to embed (Windows)" OFF )
+ENDIF()
+
+
+IF(WIN32)
+	# By default, libgit2 is built with WinHTTP.  To use the built-in
+	# HTTP transport, invoke CMake with the "-DWINHTTP=OFF" argument.
+	OPTION(	WINHTTP			"Use Win32 WinHTTP routines"	ON	)
+ENDIF()
+
+IF(MSVC)
+	# Enable MSVC CRTDBG memory leak reporting when in debug mode.
+	OPTION(MSVC_CRTDBG "Enable CRTDBG memory leak reporting" OFF)
+ENDIF()
+
+FILE(STRINGS "${libgit2_SOURCE_DIR}/include/git2/version.h" GIT2_HEADER REGEX "^#define LIBGIT2_VERSION \"[^\"]*\"$")
+
+STRING(REGEX REPLACE "^.*LIBGIT2_VERSION \"([0-9]+).*$" "\\1" LIBGIT2_VERSION_MAJOR "${GIT2_HEADER}")
+STRING(REGEX REPLACE "^.*LIBGIT2_VERSION \"[0-9]+\\.([0-9]+).*$" "\\1" LIBGIT2_VERSION_MINOR  "${GIT2_HEADER}")
+STRING(REGEX REPLACE "^.*LIBGIT2_VERSION \"[0-9]+\\.[0-9]+\\.([0-9]+).*$" "\\1" LIBGIT2_VERSION_REV "${GIT2_HEADER}")
+SET(LIBGIT2_VERSION_STRING "${LIBGIT2_VERSION_MAJOR}.${LIBGIT2_VERSION_MINOR}.${LIBGIT2_VERSION_REV}")
+
+FILE(STRINGS "${libgit2_SOURCE_DIR}/include/git2/version.h" GIT2_HEADER_SOVERSION REGEX "^#define LIBGIT2_SOVERSION [0-9]+$")
+STRING(REGEX REPLACE "^.*LIBGIT2_SOVERSION ([0-9]+)$" "\\1" LIBGIT2_SOVERSION "${GIT2_HEADER_SOVERSION}")
+
+# Platform specific compilation flags
+IF (MSVC)
+	ADD_DEFINITIONS(-D_SCL_SECURE_NO_WARNINGS)
+	ADD_DEFINITIONS(-D_CRT_SECURE_NO_DEPRECATE)
+	ADD_DEFINITIONS(-D_CRT_NONSTDC_NO_DEPRECATE)
+
+	STRING(REPLACE "/Zm1000" " " CMAKE_C_FLAGS "${CMAKE_C_FLAGS}")
+
+	# /GF - String pooling
+	# /MP - Parallel build
+	SET(CMAKE_C_FLAGS "/GF /MP /nologo ${CMAKE_C_FLAGS}")
+
+	IF (STDCALL)
+		# /Gz - stdcall calling convention
+		SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} /Gz")
+	ENDIF ()
+
+	IF (STATIC_CRT)
+		SET(CRT_FLAG_DEBUG "/MTd")
+		SET(CRT_FLAG_RELEASE "/MT")
+	ELSE()
+		SET(CRT_FLAG_DEBUG "/MDd")
+		SET(CRT_FLAG_RELEASE "/MD")
+	ENDIF()
+
+	IF (MSVC_CRTDBG)
+		SET(GIT_MSVC_CRTDBG 1)
+		SET(CRT_FLAG_DEBUG "${CRT_FLAG_DEBUG}")
+		SET(CMAKE_C_STANDARD_LIBRARIES "${CMAKE_C_STANDARD_LIBRARIES} Dbghelp.lib")
+	ENDIF()
+
+	# /Zi - Create debugging information
+	# /Od - Disable optimization
+	# /D_DEBUG - #define _DEBUG
+	# /MTd - Statically link the multithreaded debug version of the CRT
+	# /MDd - Dynamically link the multithreaded debug version of the CRT
+	# /RTC1 - Run time checks
+	SET(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} /Zi /Od /D_DEBUG /RTC1 ${CRT_FLAG_DEBUG}")
+
+	# /DNDEBUG - Disables asserts
+	# /MT - Statically link the multithreaded release version of the CRT
+	# /MD - Dynamically link the multithreaded release version of the CRT
+	# /O2 - Optimize for speed
+	# /Oy - Enable frame pointer omission (FPO) (otherwise CMake will automatically turn it off)
+	# /GL - Link time code generation (whole program optimization)
+	# /Gy - Function-level linking
+	SET(CMAKE_C_FLAGS_RELEASE "/DNDEBUG /O2 /Oy /GL /Gy ${CRT_FLAG_RELEASE}")
+
+	# /Oy- - Disable frame pointer omission (FPO)
+	SET(CMAKE_C_FLAGS_RELWITHDEBINFO "/DNDEBUG /Zi /O2 /Oy- /GL /Gy ${CRT_FLAG_RELEASE}")
+
+	# /O1 - Optimize for size
+	SET(CMAKE_C_FLAGS_MINSIZEREL "/DNDEBUG /O1 /Oy /GL /Gy ${CRT_FLAG_RELEASE}")
+
+	# /DYNAMICBASE - Address space load randomization (ASLR)
+	# /NXCOMPAT - Data execution prevention (DEP)
+	# /LARGEADDRESSAWARE - >2GB user address space on x86
+	# /VERSION - Embed version information in PE header
+	SET(CMAKE_EXE_LINKER_FLAGS "/DYNAMICBASE /NXCOMPAT /LARGEADDRESSAWARE /VERSION:${LIBGIT2_VERSION_MAJOR}.${LIBGIT2_VERSION_MINOR}")
+
+	# /DEBUG - Create a PDB
+	# /LTCG - Link time code generation (whole program optimization)
+	# /OPT:REF /OPT:ICF - Fold out duplicate code at link step
+	# /INCREMENTAL:NO - Required to use /LTCG
+	# /DEBUGTYPE:cv,fixup - Additional data embedded in the PDB (requires /INCREMENTAL:NO, so not on for Debug)
+	SET(CMAKE_EXE_LINKER_FLAGS_DEBUG "/DEBUG")
+	SET(CMAKE_EXE_LINKER_FLAGS_RELEASE "/RELEASE /LTCG /OPT:REF /OPT:ICF /INCREMENTAL:NO")
+	SET(CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO "/DEBUG /RELEASE /LTCG /OPT:REF /OPT:ICF /INCREMENTAL:NO /DEBUGTYPE:cv,fixup")
+	SET(CMAKE_EXE_LINKER_FLAGS_MINSIZEREL "/RELEASE /LTCG /OPT:REF /OPT:ICF /INCREMENTAL:NO")
+
+	# Same linker settings for DLL as EXE
+	SET(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS}")
+	SET(CMAKE_SHARED_LINKER_FLAGS_DEBUG "${CMAKE_EXE_LINKER_FLAGS_DEBUG}")
+	SET(CMAKE_SHARED_LINKER_FLAGS_RELEASE "${CMAKE_EXE_LINKER_FLAGS_RELEASE}")
+	SET(CMAKE_SHARED_LINKER_FLAGS_RELWITHDEBINFO "${CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO}")
+	SET(CMAKE_SHARED_LINKER_FLAGS_MINSIZEREL "${CMAKE_EXE_LINKER_FLAGS_MINSIZEREL}")
+ELSE ()
+	IF (ENABLE_REPRODUCIBLE_BUILDS)
+		SET(CMAKE_C_ARCHIVE_CREATE "<CMAKE_AR> Dqc <TARGET> <LINK_FLAGS> <OBJECTS>")
+		SET(CMAKE_C_ARCHIVE_APPEND "<CMAKE_AR> Dq  <TARGET> <LINK_FLAGS> <OBJECTS>")
+		SET(CMAKE_C_ARCHIVE_FINISH "<CMAKE_RANLIB> -D <TARGET>")
+	ENDIF()
+
+	SET(CMAKE_C_FLAGS "-D_GNU_SOURCE ${CMAKE_C_FLAGS}")
+
+	ENABLE_WARNINGS(all)
+	ENABLE_WARNINGS(extra)
+
+	IF (CMAKE_SYSTEM_NAME MATCHES "(Solaris|SunOS)")
+		SET(CMAKE_C_FLAGS "-std=c99 -D_POSIX_C_SOURCE=200112L -D__EXTENSIONS__ -D_POSIX_PTHREAD_SEMANTICS ${CMAKE_C_FLAGS}")
+	ENDIF()
+
+	SET(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -D_DEBUG -O0")
+
+	IF (MINGW OR MSYS) # MinGW and MSYS always do PIC and complain if we tell them to
+		STRING(REGEX REPLACE "-fPIC" "" CMAKE_SHARED_LIBRARY_C_FLAGS "${CMAKE_SHARED_LIBRARY_C_FLAGS}")
+	ELSEIF (BUILD_SHARED_LIBS)
+		ADD_C_FLAG_IF_SUPPORTED(-fvisibility=hidden)
+
+		SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fPIC")
+	ENDIF ()
+
+	IF (MINGW)
+		# MinGW >= 3.14 uses the C99-style stdio functions
+		# automatically, but forks like mingw-w64 still want
+		# us to define this in order to use them
+		ADD_DEFINITIONS(-D__USE_MINGW_ANSI_STDIO=1)
+	ENDIF ()
+
+	ENABLE_WARNINGS(documentation)
+	DISABLE_WARNINGS(missing-field-initializers)
+	ENABLE_WARNINGS(strict-aliasing)
+	ENABLE_WARNINGS(strict-prototypes)
+	ENABLE_WARNINGS(declaration-after-statement)
+	ENABLE_WARNINGS(shift-count-overflow)
+	DISABLE_WARNINGS(unused-const-variable)
+	DISABLE_WARNINGS(unused-function)
+
+	IF (APPLE) # Apple deprecated OpenSSL
+	    DISABLE_WARNINGS(deprecated-declarations)
+	ENDIF()
+
+	IF (PROFILE)
+		SET(CMAKE_C_FLAGS "-pg ${CMAKE_C_FLAGS}")
+		SET(CMAKE_EXE_LINKER_FLAGS "-pg ${CMAKE_EXE_LINKER_FLAGS}")
+	ENDIF ()
+ENDIF()
+
+IF( NOT CMAKE_CONFIGURATION_TYPES )
+	# Build Debug by default
+	IF (NOT CMAKE_BUILD_TYPE)
+		SET(CMAKE_BUILD_TYPE "Debug" CACHE STRING "Choose the type of build, options are: Debug Release RelWithDebInfo MinSizeRel." FORCE)
+	ENDIF ()
+ELSE()
+	# Using a multi-configuration generator eg MSVC or Xcode
+	# that uses CMAKE_CONFIGURATION_TYPES and not CMAKE_BUILD_TYPE
+ENDIF()
+
+ADD_SUBDIRECTORY(src)
+
+# Tests
+IF (NOT MSVC)
+   IF (NOT BUILD_SHARED_LIBS)
+       SET(CMAKE_FIND_LIBRARY_SUFFIXES ".a")
+   ENDIF()
+ENDIF ()
+
+IF (BUILD_CLAR)
+	ENABLE_TESTING()
+	ADD_SUBDIRECTORY(tests)
+ENDIF ()
+
+IF (TAGS)
+	FIND_PROGRAM(CTAGS ctags)
+	IF (NOT CTAGS)
+		MESSAGE(FATAL_ERROR "Could not find ctags command")
+	ENDIF ()
+
+	FILE(GLOB_RECURSE SRC_ALL *.[ch])
+
+	ADD_CUSTOM_COMMAND(
+		OUTPUT tags
+		COMMAND ${CTAGS} -a ${SRC_ALL}
+		DEPENDS ${SRC_ALL}
+	)
+	ADD_CUSTOM_TARGET(
+		do_tags ALL
+		DEPENDS tags
+	)
+ENDIF ()
+
+IF (BUILD_EXAMPLES)
+	ADD_SUBDIRECTORY(examples)
+ENDIF ()
+
+IF(CMAKE_VERSION VERSION_GREATER 3)
+	FEATURE_SUMMARY(WHAT ENABLED_FEATURES DESCRIPTION "Enabled features:")
+	FEATURE_SUMMARY(WHAT DISABLED_FEATURES DESCRIPTION "Disabled features:")
+ELSE()
+	PRINT_ENABLED_FEATURES()
+	PRINT_DISABLED_FEATURES()
+ENDIF()

vendor/libgit2-sys/libgit2/CODE_OF_CONDUCT.md

diff --git a/vendor/libgit2-sys/libgit2/CODE_OF_CONDUCT.md b/vendor/libgit2-sys/libgit2/CODE_OF_CONDUCT.md
new file mode 100644
index 0000000..0a0e4eb
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/CODE_OF_CONDUCT.md
@@ -0,0 +1,75 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+In the interest of fostering an open and welcoming environment, we as
+contributors and maintainers pledge to making participation in our project and
+our community a harassment-free experience for everyone, regardless of age, body
+size, disability, ethnicity, gender identity and expression, level of experience,
+nationality, personal appearance, race, religion, or sexual identity and
+orientation.
+
+## Our Standards
+
+Examples of behavior that contributes to creating a positive environment
+include:
+
+* Using welcoming and inclusive language
+* Being respectful of differing viewpoints and experiences
+* Gracefully accepting constructive criticism
+* Focusing on what is best for the community
+* Showing empathy towards other community members
+
+Examples of unacceptable behavior by participants include:
+
+* The use of sexualized language or imagery and unwelcome sexual attention or
+advances
+* Trolling, insulting/derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or electronic
+  address, without explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Our Responsibilities
+
+Project maintainers are responsible for clarifying the standards of acceptable
+behavior and are expected to take appropriate and fair corrective action in
+response to any instances of unacceptable behavior.
+
+Project maintainers have the right and responsibility to remove, edit, or
+reject comments, commits, code, wiki edits, issues, and other contributions
+that are not aligned to this Code of Conduct, or to ban temporarily or
+permanently any contributor for other behaviors that they deem inappropriate,
+threatening, offensive, or harmful.
+
+## Scope
+
+This Code of Conduct applies both within project spaces and in public spaces
+when an individual is representing the project or its community. Examples of
+representing a project or community include using an official project e-mail
+address, posting via an official social media account, or acting as an appointed
+representative at an online or offline event. Representation of a project may be
+further defined and clarified by project maintainers.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported by contacting the project team at [libgit2@gmail.com][email]. All
+complaints will be reviewed and investigated and will result in a response that
+is deemed necessary and appropriate to the circumstances. The project team is
+obligated to maintain confidentiality with regard to the reporter of an incident.
+Further details of specific enforcement policies may be posted separately.
+
+Project maintainers who do not follow or enforce the Code of Conduct in good
+faith may face temporary or permanent repercussions as determined by other
+members of the project's leadership.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4,
+available at [http://contributor-covenant.org/version/1/4][version]
+
+[email]: mailto:libgit2@gmail.com
+[homepage]: http://contributor-covenant.org
+[version]: http://contributor-covenant.org/version/1/4/

vendor/libgit2-sys/libgit2/CONTRIBUTING.md

diff --git a/vendor/libgit2-sys/libgit2/CONTRIBUTING.md b/vendor/libgit2-sys/libgit2/CONTRIBUTING.md
new file mode 100644
index 0000000..7f37223
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/CONTRIBUTING.md
@@ -0,0 +1,177 @@
+# Welcome to libgit2!
+
+We're making it easy to do interesting things with git, and we'd love to have
+your help.
+
+## Licensing
+
+By contributing to libgit2, you agree to release your contribution under
+the terms of the license.  Except for the `examples` directory, all code
+is released under the [GPL v2 with linking exception](COPYING).
+
+The `examples` code is governed by the
+[CC0 Public Domain Dedication](examples/COPYING), so that you may copy
+from them into your own application.
+
+## Discussion & Chat
+
+We hang out in the
+[`#libgit2`](http://webchat.freenode.net/?channels=#libgit2)) channel on
+irc.freenode.net.
+
+Also, feel free to open an
+[Issue](https://github.com/libgit2/libgit2/issues/new) to start a discussion
+about any concerns you have.  We like to use Issues for that so there is an
+easily accessible permanent record of the conversation.
+
+## Libgit2 Versions
+
+The `master` branch is the main branch where development happens.
+Releases are tagged
+(e.g. [v0.21.0](https://github.com/libgit2/libgit2/releases/tag/v0.21.0) )
+and when a critical bug fix needs to be backported, it will be done on a
+`<tag>-maint` maintenance branch.
+
+## Reporting Bugs
+
+First, know which version of libgit2 your problem is in and include it in
+your bug report.  This can either be a tag (e.g.
+[v0.17.0](https://github.com/libgit2/libgit2/releases/tag/v0.17.0)) or a
+commit SHA
+(e.g. [01be7863](https://github.com/libgit2/libgit2/commit/01be7863)).
+Using [`git describe`](http://git-scm.com/docs/git-describe) is a
+great way to tell us what version you're working with.
+
+If you're not running against the latest `master` branch version,
+please compile and test against that to avoid re-reporting an issue that's
+already been fixed.
+
+It's *incredibly* helpful to be able to reproduce the problem.  Please
+include a list of steps, a bit of code, and/or a zipped repository (if
+possible).  Note that some of the libgit2 developers are employees of
+GitHub, so if your repository is private, find us on IRC and we'll figure
+out a way to help you.
+
+## Pull Requests
+
+Our work flow is a [typical GitHub
+flow](https://guides.github.com/introduction/flow/index.html), where
+contributors fork the [libgit2 repository](https://github.com/libgit2/libgit2),
+make their changes on branch, and submit a
+[Pull Request](https://help.github.com/articles/using-pull-requests)
+(a.k.a. "PR").  Pull requests should usually be targeted at the `master`
+branch.
+
+Life will be a lot easier for you (and us) if you follow this pattern
+(i.e. fork, named branch, submit PR).  If you use your fork's `master`
+branch directly, things can get messy.
+
+Please include a nice description of your changes when you submit your PR;
+if we have to read the whole diff to figure out why you're contributing
+in the first place, you're less likely to get feedback and have your change
+merged in.
+
+In addition to outlining your thought process in the PR's description, please
+also try to document it in your commits. We welcome it if every commit has a
+description of why you have been doing your changes alongside with your
+reasoning why this is a good idea. The messages shall be written in
+present-tense and in an imperative style (e.g. "Add feature foobar", not "Added
+feature foobar" or "Adding feature foobar"). Lines should be wrapped at 80
+characters so people with small screens are able to read the commit messages in
+their terminal without any problem.
+
+To make it easier to attribute commits to certain parts of our code base, we
+also prefer to have the commit subject be prefixed with a "scope". E.g. if you
+are changing code in our merging subsystem, make sure to prefix the subject with
+"merge:". The first word following the colon shall start with an lowercase
+letter. The maximum line length for the subject is 70 characters, preferably
+shorter.
+
+If you are starting to work on a particular area, feel free to submit a PR
+that highlights your work in progress (and note in the PR title that it's
+not ready to merge). These early PRs are welcome and will help in getting
+visibility for your fix, allow others to comment early on the changes and
+also let others know that you are currently working on something.
+
+Before wrapping up a PR, you should be sure to:
+
+* Write tests to cover any functional changes
+* Update documentation for any changed public APIs
+* Add to the [`CHANGELOG.md`](CHANGELOG.md) file describing any major changes
+
+## Unit Tests
+
+We believe that our unit tests allow us to keep the quality of libgit2
+high: any new changes must not cause unit test failures, and new changes
+should include unit tests that cover the bug fixes or new features.
+For bug fixes, we prefer unit tests that illustrate the failure before
+the change, but pass with your changes.
+
+In addition to new tests, please ensure that your changes do not cause
+any other test failures.  Running the entire test suite is helpful
+before you submit a pull request.  When you build libgit2, the test
+suite will also be built.  You can run most of the tests by simply running
+the resultant `libgit2_clar` binary.  If you want to run a specific
+unit test, you can name it with the `-s` option.  For example:
+
+    libgit2_clar -sstatus::worktree::long_filenames
+
+Or you can run an entire class of tests.  For example, to run all the
+worktree status tests:
+
+    libgit2_clar -sstatus::worktree
+
+The default test run is fairly exhaustive, but it will exclude some
+unit tests by default: in particular, those that talk to network
+servers and the tests that manipulate the filesystem in onerous
+ways (and may need to have special privileges to run).  To run the
+network tests:
+
+    libgit2_clar -ionline
+
+In addition, various tests may be enabled by environment variables,
+like the ones that write exceptionally large repositories or manipulate
+the filesystem structure in unexpected ways.  These tests *may be
+dangerous* to run on a normal machine and may harm your filesystem.  It's
+not recommended that you run these; instead, the continuous integration
+servers will run these (in a sandbox).
+
+## Porting Code From Other Open-Source Projects
+
+`libgit2` is licensed under the terms of the GPL v2 with a linking
+exception.  Any code brought in must be compatible with those terms.
+
+The most common case is porting code from core Git.  Git is a pure GPL
+project, which means that in order to port code to this project, we need the
+explicit permission of the author.  Check the
+[`git.git-authors`](https://github.com/libgit2/libgit2/blob/development/git.git-authors)
+file for authors who have already consented.
+
+Other licenses have other requirements; check the license of the library
+you're porting code *from* to see what you need to do.  As a general rule,
+MIT and BSD (3-clause) licenses are typically no problem.  Apache 2.0
+license typically doesn't work due to GPL incompatibility.
+
+If your pull request uses code from core Git, another project, or code
+from a forum / Stack Overflow, then *please* flag this in your PR and make
+sure you've given proper credit to the original author in the code
+snippet.
+
+## Style Guide
+
+The public API of `libgit2` is [ANSI C](http://en.wikipedia.org/wiki/ANSI_C)
+(a.k.a. C89) compatible.  Internally, `libgit2` is written using a portable
+subset of C99 - in order to compile with GCC, Clang, MSVC, etc., we keep
+local variable declarations at the tops of blocks only and avoid `//` style
+comments.  Additionally, `libgit2` follows some extra conventions for
+function and type naming, code formatting, and testing.
+
+We like to keep the source code consistent and easy to read.  Maintaining
+this takes some discipline, but it's been more than worth it.  Take a look
+at the [conventions
+file](https://github.com/libgit2/libgit2/blob/development/CONVENTIONS.md).
+
+## Starter Projects
+
+See our [projects
+list](https://github.com/libgit2/libgit2/blob/development/PROJECTS.md).

vendor/libgit2-sys/libgit2/CONVENTIONS.md

diff --git a/vendor/libgit2-sys/libgit2/CONVENTIONS.md b/vendor/libgit2-sys/libgit2/CONVENTIONS.md
new file mode 100644
index 0000000..ffb696a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/CONVENTIONS.md
@@ -0,0 +1,266 @@
+# Libgit2 Conventions
+
+We like to keep the source consistent and readable.  Herein are some
+guidelines that should help with that.
+
+## External API
+
+We have a few rules to avoid surprising ways of calling functions and
+some rules for consumers of the library to avoid stepping on each
+other's toes.
+
+ - Property accessors return the value directly (e.g. an `int` or
+   `const char *`) but if a function can fail, we return a `int` value
+   and the output parameters go first in the parameter list, followed
+   by the object that a function is operating on, and then any other
+   arguments the function may need.
+
+ - If a function returns an object as a return value, that function is
+   a getter and the object's lifetime is tied to the parent
+   object. Objects which are returned as the first argument as a
+   pointer-to-pointer are owned by the caller and it is responsible
+   for freeing it. Strings are returned via `git_buf` in order to
+   allow for re-use and safe freeing.
+
+ - Most of what libgit2 does relates to I/O so as a general rule
+   you should assume that any function can fail due to errors as even
+   getting data from the filesystem can result in all sorts of errors
+   and complex failure cases.
+
+ - Paths inside the Git system are separated by a slash (0x2F). If a
+   function accepts a path on disk, then backslashes (0x5C) are also
+   accepted on Windows.
+
+ - Do not mix allocators. If something has been allocated by libgit2,
+   you do not know which is the right free function in the general
+   case. Use the free functions provided for each object type.
+
+## Compatibility
+
+`libgit2` runs on many different platforms with many different compilers.
+
+The public API of `libgit2` is [ANSI C](http://en.wikipedia.org/wiki/ANSI_C)
+(a.k.a. C89) compatible.
+
+Internally, `libgit2` is written using a portable subset of C99 - in order
+to maximize compatibility (e.g. with MSVC) we avoid certain C99
+extensions.  Specifically, we keep local variable declarations at the tops
+of blocks only and we avoid `//` style comments.
+
+Also, to the greatest extent possible, we try to avoid lots of `#ifdef`s
+inside the core code base.  This is somewhat unavoidable, but since it can
+really hamper maintainability, we keep it to a minimum.
+
+## Match Surrounding Code
+
+If there is one rule to take away from this document, it is *new code should
+match the surrounding code in a way that makes it impossible to distinguish
+the new from the old.* Consistency is more important to us than anyone's
+personal opinion about where braces should be placed or spaces vs. tabs.
+
+If a section of code is being completely rewritten, it is okay to bring it
+in line with the standards that are laid out here, but we will not accept
+submissions that contain a large number of changes that are merely
+reformatting.
+
+## Naming Things
+
+All external types and functions start with `git_` and all `#define` macros
+start with `GIT_`.  The `libgit2` API is mostly broken into related
+functional modules each with a corresponding header.  All functions in a
+module should be named like `git_modulename_functioname()`
+(e.g. `git_repository_open()`).
+
+Functions with a single output parameter should name that parameter `out`.
+Multiple outputs should be named `foo_out`, `bar_out`, etc.
+
+Parameters of type `git_oid` should be named `id`, or `foo_id`.  Calls that
+return an OID should be named `git_foo_id`.
+
+Where a callback function is used, the function should also include a
+user-supplied extra input that is a `void *` named "payload" that will be
+passed through to the callback at each invocation.
+
+## Typedefs
+
+Wherever possible, use `typedef`.  In some cases, if a structure is just a
+collection of function pointers, the pointer types don't need to be
+separately typedef'd, but loose function pointer types should be.
+
+## Exports
+
+All exported functions must be declared as:
+
+```c
+GIT_EXTERN(result_type) git_modulename_functionname(arg_list);
+```
+
+## Internals
+
+Functions whose *modulename* is followed by two underscores,
+for example `git_odb__read_packed`, are semi-private functions.
+They are primarily intended for use within the library itself,
+and may disappear or change their signature in a future release.
+
+## Parameters
+
+Out parameters come first.
+
+Whenever possible, pass argument pointers as `const`.  Some structures (such
+as `git_repository` and `git_index`) have mutable internal structure that
+prevents this.
+
+Callbacks should always take a `void *` payload as their last parameter.
+Callback pointers are grouped with their payloads, and typically come last
+when passed as arguments:
+
+```c
+int git_foo(git_repository *repo, git_foo_cb callback, void *payload);
+```
+
+## Memory Ownership
+
+Some APIs allocate memory which the caller is responsible for freeing; others
+return a pointer into a buffer that's owned by some other object.  Make this
+explicit in the documentation.
+
+## Return codes
+
+Most public APIs should return an `int` error code.  As is typical with most
+C library functions, a zero value indicates success and a negative value
+indicates failure.
+
+Some bindings will transform these returned error codes into exception
+types, so returning a semantically appropriate error code is important.
+Check
+[`include/git2/errors.h`](https://github.com/libgit2/libgit2/blob/development/include/git2/errors.h)
+for the return codes already defined.
+
+In your implementation, use `giterr_set()` to provide extended error
+information to callers.
+
+If a `libgit2` function internally invokes another function that reports an
+error, but the error is not propagated up, use `giterr_clear()` to prevent
+callers from getting the wrong error message later on.
+
+
+## Structs
+
+Most public types should be opaque, e.g.:
+
+```C
+typedef struct git_odb git_odb;
+```
+
+...with allocation functions returning an "instance" created within
+the library, and not within the application.  This allows the type
+to grow (or shrink) in size without rebuilding client code.
+
+To preserve ABI compatibility, include an `int version` field in all opaque
+structures, and initialize to the latest version in the construction call.
+Increment the "latest" version whenever the structure changes, and try to only
+append to the end of the structure.
+
+## Option Structures
+
+If a function's parameter count is too high, it may be desirable to package
+up the options in a structure.  Make them transparent, include a version
+field, and provide an initializer constant or constructor.  Using these
+structures should be this easy:
+
+```C
+git_foo_options opts = GIT_FOO_OPTIONS_INIT;
+opts.baz = BAZ_OPTION_ONE;
+git_foo(&opts);
+```
+
+## Enumerations
+
+Typedef all enumerated types.  If each option stands alone, use the enum
+type for passing them as parameters; if they are flags to be OR'ed together,
+pass them as `unsigned int` or `uint32_t` or some appropriate type.
+
+## Code Layout
+
+Try to keep lines less than 80 characters long.  This is a loose
+requirement, but going significantly over 80 columns is not nice.
+
+Use common sense to wrap most code lines; public function declarations
+can use a couple of different styles:
+
+```c
+/** All on one line is okay if it fits */
+GIT_EXTERN(int) git_foo_simple(git_oid *id);
+
+/** Otherwise one argument per line is a good next step */
+GIT_EXTERN(int) git_foo_id(
+	git_oid **out,
+	int a,
+	int b);
+```
+
+Indent with tabs; set your editor's tab width to 4 for best effect.
+
+Avoid trailing whitespace and only commit Unix-style newlines (i.e. no CRLF
+in the repository - just set `core.autocrlf` to true if you are writing code
+on a Windows machine).
+
+## Documentation
+
+All comments should conform to Doxygen "javadoc" style conventions for
+formatting the public API documentation.  Try to document every parameter,
+and keep the comments up to date if you change the parameter list.
+
+## Public Header Template
+
+Use this template when creating a new public header.
+
+```C
+#ifndef INCLUDE_git_${filename}_h__
+#define INCLUDE_git_${filename}_h__
+
+#include "git/common.h"
+
+/**
+ * @file git/${filename}.h
+ * @brief Git some description
+ * @defgroup git_${filename} some description routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/* ... definitions ... */
+
+/** @} */
+GIT_END_DECL
+#endif
+```
+
+## Inlined functions
+
+All inlined functions must be declared as:
+
+```C
+GIT_INLINE(result_type) git_modulename_functionname(arg_list);
+```
+
+`GIT_INLINE` (or `inline`) should not be used in public headers in order
+to preserve ANSI C compatibility.
+
+## Tests
+
+`libgit2` uses the [clar](https://github.com/vmg/clar) testing framework.
+
+All PRs should have corresponding tests.
+
+* If the PR fixes an existing issue, the test should fail prior to applying
+  the PR and succeed after applying it.
+* If the PR is for new functionality, then the tests should exercise that
+  new functionality to a certain extent.  We don't require 100% coverage
+  right now (although we are getting stricter over time).
+
+When adding new tests, we prefer if you attempt to reuse existing test data
+(in `tests-clar/resources/`) if possible.  If you are going to add new test
+repositories, please try to strip them of unnecessary files (e.g. sample
+hooks, etc).

vendor/libgit2-sys/libgit2/COPYING

diff --git a/vendor/libgit2-sys/libgit2/COPYING b/vendor/libgit2-sys/libgit2/COPYING
new file mode 100644
index 0000000..da695eb
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/COPYING
@@ -0,0 +1,993 @@
+ libgit2 is Copyright (C) the libgit2 contributors,
+ unless otherwise stated. See the AUTHORS file for details.
+
+ Note that the only valid version of the GPL as far as this project
+ is concerned is _this_ particular version of the license (ie v2, not
+ v2.2 or v3.x or whatever), unless explicitly otherwise stated.
+
+----------------------------------------------------------------------
+
+			LINKING EXCEPTION
+
+ In addition to the permissions in the GNU General Public License,
+ the authors give you unlimited permission to link the compiled
+ version of this library into combinations with other programs,
+ and to distribute those combinations without any restriction
+ coming from the use of this file.  (The General Public License
+ restrictions do apply in other respects; for example, they cover
+ modification of the file, and distribution when not linked into
+ a combined executable.)
+
+----------------------------------------------------------------------
+
+		    GNU GENERAL PUBLIC LICENSE
+		       Version 2, June 1991
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.
+                       59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+			    Preamble
+
+  The licenses for most software are designed to take away your
+freedom to share and change it.  By contrast, the GNU General Public
+License is intended to guarantee your freedom to share and change free
+software--to make sure the software is free for all its users.  This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it.  (Some other Free Software Foundation software is covered by
+the GNU Library General Public License instead.)  You can apply it to
+your programs, too.
+
+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
+
+  To protect your rights, we need to make restrictions that forbid
+anyone to deny you these rights or to ask you to surrender the rights.
+These restrictions translate to certain responsibilities for you if you
+distribute copies of the software, or if you modify it.
+
+  For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must give the recipients all the rights that
+you have.  You must make sure that they, too, receive or can get the
+source code.  And you must show them these terms so they know their
+rights.
+
+  We protect your rights with two steps: (1) copyright the software, and
+(2) offer you this license which gives you legal permission to copy,
+distribute and/or modify the software.
+
+  Also, for each author's protection and ours, we want to make certain
+that everyone understands that there is no warranty for this free
+software.  If the software is modified by someone else and passed on, we
+want its recipients to know that what they have is not the original, so
+that any problems introduced by others will not reflect on the original
+authors' reputations.
+
+  Finally, any free program is threatened constantly by software
+patents.  We wish to avoid the danger that redistributors of a free
+program will individually obtain patent licenses, in effect making the
+program proprietary.  To prevent this, we have made it clear that any
+patent must be licensed for everyone's free use or not licensed at all.
+
+  The precise terms and conditions for copying, distribution and
+modification follow.
+
+		    GNU GENERAL PUBLIC LICENSE
+   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+  0. This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
+under the terms of this General Public License.  The "Program", below,
+refers to any such program or work, and a "work based on the Program"
+means either the Program or any derivative work under copyright law:
+that is to say, a work containing the Program or a portion of it,
+either verbatim or with modifications and/or translated into another
+language.  (Hereinafter, translation is included without limitation in
+the term "modification".)  Each licensee is addressed as "you".
+
+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope.  The act of
+running the Program is not restricted, and the output from the Program
+is covered only if its contents constitute a work based on the
+Program (independent of having been made by running the Program).
+Whether that is true depends on what the Program does.
+
+  1. You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
+conspicuously and appropriately publish on each copy an appropriate
+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
+and give any other recipients of the Program a copy of this License
+along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a fee.
+
+  2. You may modify your copy or copies of the Program or any portion
+of it, thus forming a work based on the Program, and copy and
+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
+
+    a) You must cause the modified files to carry prominent notices
+    stating that you changed the files and the date of any change.
+
+    b) You must cause any work that you distribute or publish, that in
+    whole or in part contains or is derived from the Program or any
+    part thereof, to be licensed as a whole at no charge to all third
+    parties under the terms of this License.
+
+    c) If the modified program normally reads commands interactively
+    when run, you must cause it, when started running for such
+    interactive use in the most ordinary way, to print or display an
+    announcement including an appropriate copyright notice and a
+    notice that there is no warranty (or else, saying that you provide
+    a warranty) and that users may redistribute the program under
+    these conditions, and telling the user how to view a copy of this
+    License.  (Exception: if the Program itself is interactive but
+    does not normally print such an announcement, your work based on
+    the Program is not required to print an announcement.)
+
+These requirements apply to the modified work as a whole.  If
+identifiable sections of that work are not derived from the Program,
+and can be reasonably considered independent and separate works in
+themselves, then this License, and its terms, do not apply to those
+sections when you distribute them as separate works.  But when you
+distribute the same sections as part of a whole which is a work based
+on the Program, the distribution of the whole must be on the terms of
+this License, whose permissions for other licensees extend to the
+entire whole, and thus to each and every part regardless of who wrote it.
+
+Thus, it is not the intent of this section to claim rights or contest
+your rights to work written entirely by you; rather, the intent is to
+exercise the right to control the distribution of derivative or
+collective works based on the Program.
+
+In addition, mere aggregation of another work not based on the Program
+with the Program (or with a work based on the Program) on a volume of
+a storage or distribution medium does not bring the other work under
+the scope of this License.
+
+  3. You may copy and distribute the Program (or a work based on it,
+under Section 2) in object code or executable form under the terms of
+Sections 1 and 2 above provided that you also do one of the following:
+
+    a) Accompany it with the complete corresponding machine-readable
+    source code, which must be distributed under the terms of Sections
+    1 and 2 above on a medium customarily used for software interchange; or,
+
+    b) Accompany it with a written offer, valid for at least three
+    years, to give any third party, for a charge no more than your
+    cost of physically performing source distribution, a complete
+    machine-readable copy of the corresponding source code, to be
+    distributed under the terms of Sections 1 and 2 above on a medium
+    customarily used for software interchange; or,
+
+    c) Accompany it with the information you received as to the offer
+    to distribute corresponding source code.  (This alternative is
+    allowed only for noncommercial distribution and only if you
+    received the program in object code or executable form with such
+    an offer, in accord with Subsection b above.)
+
+The source code for a work means the preferred form of the work for
+making modifications to it.  For an executable work, complete source
+code means all the source code for all modules it contains, plus any
+associated interface definition files, plus the scripts used to
+control compilation and installation of the executable.  However, as a
+special exception, the source code distributed need not include
+anything that is normally distributed (in either source or binary
+form) with the major components (compiler, kernel, and so on) of the
+operating system on which the executable runs, unless that component
+itself accompanies the executable.
+
+If distribution of executable or object code is made by offering
+access to copy from a designated place, then offering equivalent
+access to copy the source code from the same place counts as
+distribution of the source code, even though third parties are not
+compelled to copy the source along with the object code.
+
+  4. You may not copy, modify, sublicense, or distribute the Program
+except as expressly provided under this License.  Any attempt
+otherwise to copy, modify, sublicense or distribute the Program is
+void, and will automatically terminate your rights under this License.
+However, parties who have received copies, or rights, from you under
+this License will not have their licenses terminated so long as such
+parties remain in full compliance.
+
+  5. You are not required to accept this License, since you have not
+signed it.  However, nothing else grants you permission to modify or
+distribute the Program or its derivative works.  These actions are
+prohibited by law if you do not accept this License.  Therefore, by
+modifying or distributing the Program (or any work based on the
+Program), you indicate your acceptance of this License to do so, and
+all its terms and conditions for copying, distributing or modifying
+the Program or works based on it.
+
+  6. Each time you redistribute the Program (or any work based on the
+Program), the recipient automatically receives a license from the
+original licensor to copy, distribute or modify the Program subject to
+these terms and conditions.  You may not impose any further
+restrictions on the recipients' exercise of the rights granted herein.
+You are not responsible for enforcing compliance by third parties to
+this License.
+
+  7. If, as a consequence of a court judgment or allegation of patent
+infringement or for any other reason (not limited to patent issues),
+conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License.  If you cannot
+distribute so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you
+may not distribute the Program at all.  For example, if a patent
+license would not permit royalty-free redistribution of the Program by
+all those who receive copies directly or indirectly through you, then
+the only way you could satisfy both it and this License would be to
+refrain entirely from distribution of the Program.
+
+If any portion of this section is held invalid or unenforceable under
+any particular circumstance, the balance of the section is intended to
+apply and the section as a whole is intended to apply in other
+circumstances.
+
+It is not the purpose of this section to induce you to infringe any
+patents or other property right claims or to contest validity of any
+such claims; this section has the sole purpose of protecting the
+integrity of the free software distribution system, which is
+implemented by public license practices.  Many people have made
+generous contributions to the wide range of software distributed
+through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing
+to distribute software through any other system and a licensee cannot
+impose that choice.
+
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
+
+  8. If the distribution and/or use of the Program is restricted in
+certain countries either by patents or by copyrighted interfaces, the
+original copyright holder who places the Program under this License
+may add an explicit geographical distribution limitation excluding
+those countries, so that distribution is permitted only in or among
+countries not thus excluded.  In such case, this License incorporates
+the limitation as if written in the body of this License.
+
+  9. The Free Software Foundation may publish revised and/or new versions
+of the General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+Each version is given a distinguishing version number.  If the Program
+specifies a version number of this License which applies to it and "any
+later version", you have the option of following the terms and conditions
+either of that version or of any later version published by the Free
+Software Foundation.  If the Program does not specify a version number of
+this License, you may choose any version ever published by the Free Software
+Foundation.
+
+  10. If you wish to incorporate parts of the Program into other free
+programs whose distribution conditions are different, write to the author
+to ask for permission.  For software which is copyrighted by the Free
+Software Foundation, write to the Free Software Foundation; we sometimes
+make exceptions for this.  Our decision will be guided by the two goals
+of preserving the free status of all derivatives of our free software and
+of promoting the sharing and reuse of software generally.
+
+			    NO WARRANTY
+
+  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
+OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
+PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
+OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
+TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
+PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
+REPAIR OR CORRECTION.
+
+  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
+REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
+INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
+OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
+
+		     END OF TERMS AND CONDITIONS
+
+	    How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+
+Also add information on how to contact you by electronic and paper mail.
+
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
+
+    Gnomovision version 69, Copyright (C) year name of author
+    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, the commands you use may
+be called something other than `show w' and `show c'; they could even be
+mouse-clicks or menu items--whatever suits your program.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the program, if
+necessary.  Here is a sample; alter the names:
+
+  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+  `Gnomovision' (which makes passes at compilers) written by James Hacker.
+
+  <signature of Ty Coon>, 1 April 1989
+  Ty Coon, President of Vice
+
+This General Public License does not permit incorporating your program into
+proprietary programs.  If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library.  If this is what you want to do, use the GNU Library General
+Public License instead of this License.
+
+----------------------------------------------------------------------
+
+The bundled ZLib code is licensed under the ZLib license:
+
+Copyright (C) 1995-2010 Jean-loup Gailly and Mark Adler
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  Jean-loup Gailly        Mark Adler
+  jloup@gzip.org          madler@alumni.caltech.edu
+
+----------------------------------------------------------------------
+
+The Clar framework is licensed under the ISC license:
+
+Copyright (c) 2011-2015 Vicent Marti
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+----------------------------------------------------------------------
+
+The regex library (deps/regex/) is licensed under the GNU LGPL
+(available at the end of this file).
+
+Definitions for data structures and routines for the regular
+expression library.
+
+Copyright (C) 1985,1989-93,1995-98,2000,2001,2002,2003,2005,2006,2008
+Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Lesser General Public
+License as published by the Free Software Foundation; either
+version 2.1 of the License, or (at your option) any later version.
+ 
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public
+License along with the GNU C Library; if not, write to the Free
+Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+----------------------------------------------------------------------
+
+The bundled winhttp definition files (deps/winhttp/) are licensed under
+the GNU LGPL (available at the end of this file).
+
+Copyright (C) 2007 Francois Gouget
+
+This library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Lesser General Public
+License as published by the Free Software Foundation; either
+version 2.1 of the License, or (at your option) any later version.
+
+This library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public
+License along with this library; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+
+----------------------------------------------------------------------
+
+                  GNU LESSER GENERAL PUBLIC LICENSE
+                       Version 2.1, February 1999
+
+ Copyright (C) 1991, 1999 Free Software Foundation, Inc.
+ 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+[This is the first released version of the Lesser GPL.  It also counts
+ as the successor of the GNU Library Public License, version 2, hence
+ the version number 2.1.]
+
+                            Preamble
+
+  The licenses for most software are designed to take away your
+freedom to share and change it.  By contrast, the GNU General Public
+Licenses are intended to guarantee your freedom to share and change
+free software--to make sure the software is free for all its users.
+
+  This license, the Lesser General Public License, applies to some
+specially designated software packages--typically libraries--of the
+Free Software Foundation and other authors who decide to use it.  You
+can use it too, but we suggest you first think carefully about whether
+this license or the ordinary General Public License is the better
+strategy to use in any particular case, based on the explanations below.
+
+  When we speak of free software, we are referring to freedom of use,
+not price.  Our General Public Licenses are designed to make sure that
+you have the freedom to distribute copies of free software (and charge
+for this service if you wish); that you receive source code or can get
+it if you want it; that you can change the software and use pieces of
+it in new free programs; and that you are informed that you can do
+these things.
+
+  To protect your rights, we need to make restrictions that forbid
+distributors to deny you these rights or to ask you to surrender these
+rights.  These restrictions translate to certain responsibilities for
+you if you distribute copies of the library or if you modify it.
+
+  For example, if you distribute copies of the library, whether gratis
+or for a fee, you must give the recipients all the rights that we gave
+you.  You must make sure that they, too, receive or can get the source
+code.  If you link other code with the library, you must provide
+complete object files to the recipients, so that they can relink them
+with the library after making changes to the library and recompiling
+it.  And you must show them these terms so they know their rights.
+
+  We protect your rights with a two-step method: (1) we copyright the
+library, and (2) we offer you this license, which gives you legal
+permission to copy, distribute and/or modify the library.
+
+  To protect each distributor, we want to make it very clear that
+there is no warranty for the free library.  Also, if the library is
+modified by someone else and passed on, the recipients should know
+that what they have is not the original version, so that the original
+author's reputation will not be affected by problems that might be
+introduced by others.
+
+  Finally, software patents pose a constant threat to the existence of
+any free program.  We wish to make sure that a company cannot
+effectively restrict the users of a free program by obtaining a
+restrictive license from a patent holder.  Therefore, we insist that
+any patent license obtained for a version of the library must be
+consistent with the full freedom of use specified in this license.
+
+  Most GNU software, including some libraries, is covered by the
+ordinary GNU General Public License.  This license, the GNU Lesser
+General Public License, applies to certain designated libraries, and
+is quite different from the ordinary General Public License.  We use
+this license for certain libraries in order to permit linking those
+libraries into non-free programs.
+
+  When a program is linked with a library, whether statically or using
+a shared library, the combination of the two is legally speaking a
+combined work, a derivative of the original library.  The ordinary
+General Public License therefore permits such linking only if the
+entire combination fits its criteria of freedom.  The Lesser General
+Public License permits more lax criteria for linking other code with
+the library.
+
+  We call this license the "Lesser" General Public License because it
+does Less to protect the user's freedom than the ordinary General
+Public License.  It also provides other free software developers Less
+of an advantage over competing non-free programs.  These disadvantages
+are the reason we use the ordinary General Public License for many
+libraries.  However, the Lesser license provides advantages in certain
+special circumstances.
+
+  For example, on rare occasions, there may be a special need to
+encourage the widest possible use of a certain library, so that it becomes
+a de-facto standard.  To achieve this, non-free programs must be
+allowed to use the library.  A more frequent case is that a free
+library does the same job as widely used non-free libraries.  In this
+case, there is little to gain by limiting the free library to free
+software only, so we use the Lesser General Public License.
+
+  In other cases, permission to use a particular library in non-free
+programs enables a greater number of people to use a large body of
+free software.  For example, permission to use the GNU C Library in
+non-free programs enables many more people to use the whole GNU
+operating system, as well as its variant, the GNU/Linux operating
+system.
+
+  Although the Lesser General Public License is Less protective of the
+users' freedom, it does ensure that the user of a program that is
+linked with the Library has the freedom and the wherewithal to run
+that program using a modified version of the Library.
+
+  The precise terms and conditions for copying, distribution and
+modification follow.  Pay close attention to the difference between a
+"work based on the library" and a "work that uses the library".  The
+former contains code derived from the library, whereas the latter must
+be combined with the library in order to run.
+
+                  GNU LESSER GENERAL PUBLIC LICENSE
+   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+  0. This License Agreement applies to any software library or other
+program which contains a notice placed by the copyright holder or
+other authorized party saying it may be distributed under the terms of
+this Lesser General Public License (also called "this License").
+Each licensee is addressed as "you".
+
+  A "library" means a collection of software functions and/or data
+prepared so as to be conveniently linked with application programs
+(which use some of those functions and data) to form executables.
+
+  The "Library", below, refers to any such software library or work
+which has been distributed under these terms.  A "work based on the
+Library" means either the Library or any derivative work under
+copyright law: that is to say, a work containing the Library or a
+portion of it, either verbatim or with modifications and/or translated
+straightforwardly into another language.  (Hereinafter, translation is
+included without limitation in the term "modification".)
+
+  "Source code" for a work means the preferred form of the work for
+making modifications to it.  For a library, complete source code means
+all the source code for all modules it contains, plus any associated
+interface definition files, plus the scripts used to control compilation
+and installation of the library.
+
+  Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope.  The act of
+running a program using the Library is not restricted, and output from
+such a program is covered only if its contents constitute a work based
+on the Library (independent of the use of the Library in a tool for
+writing it).  Whether that is true depends on what the Library does
+and what the program that uses the Library does.
+
+  1. You may copy and distribute verbatim copies of the Library's
+complete source code as you receive it, in any medium, provided that
+you conspicuously and appropriately publish on each copy an
+appropriate copyright notice and disclaimer of warranty; keep intact
+all the notices that refer to this License and to the absence of any
+warranty; and distribute a copy of this License along with the
+Library.
+
+  You may charge a fee for the physical act of transferring a copy,
+and you may at your option offer warranty protection in exchange for a
+fee.
+
+  2. You may modify your copy or copies of the Library or any portion
+of it, thus forming a work based on the Library, and copy and
+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
+
+    a) The modified work must itself be a software library.
+
+    b) You must cause the files modified to carry prominent notices
+    stating that you changed the files and the date of any change.
+
+    c) You must cause the whole of the work to be licensed at no
+    charge to all third parties under the terms of this License.
+
+    d) If a facility in the modified Library refers to a function or a
+    table of data to be supplied by an application program that uses
+    the facility, other than as an argument passed when the facility
+    is invoked, then you must make a good faith effort to ensure that,
+    in the event an application does not supply such function or
+    table, the facility still operates, and performs whatever part of
+    its purpose remains meaningful.
+
+    (For example, a function in a library to compute square roots has
+    a purpose that is entirely well-defined independent of the
+    application.  Therefore, Subsection 2d requires that any
+    application-supplied function or table used by this function must
+    be optional: if the application does not supply it, the square
+    root function must still compute square roots.)
+
+These requirements apply to the modified work as a whole.  If
+identifiable sections of that work are not derived from the Library,
+and can be reasonably considered independent and separate works in
+themselves, then this License, and its terms, do not apply to those
+sections when you distribute them as separate works.  But when you
+distribute the same sections as part of a whole which is a work based
+on the Library, the distribution of the whole must be on the terms of
+this License, whose permissions for other licensees extend to the
+entire whole, and thus to each and every part regardless of who wrote
+it.
+
+Thus, it is not the intent of this section to claim rights or contest
+your rights to work written entirely by you; rather, the intent is to
+exercise the right to control the distribution of derivative or
+collective works based on the Library.
+
+In addition, mere aggregation of another work not based on the Library
+with the Library (or with a work based on the Library) on a volume of
+a storage or distribution medium does not bring the other work under
+the scope of this License.
+
+  3. You may opt to apply the terms of the ordinary GNU General Public
+License instead of this License to a given copy of the Library.  To do
+this, you must alter all the notices that refer to this License, so
+that they refer to the ordinary GNU General Public License, version 2,
+instead of to this License.  (If a newer version than version 2 of the
+ordinary GNU General Public License has appeared, then you can specify
+that version instead if you wish.)  Do not make any other change in
+these notices.
+
+  Once this change is made in a given copy, it is irreversible for
+that copy, so the ordinary GNU General Public License applies to all
+subsequent copies and derivative works made from that copy.
+
+  This option is useful when you wish to copy part of the code of
+the Library into a program that is not a library.
+
+  4. You may copy and distribute the Library (or a portion or
+derivative of it, under Section 2) in object code or executable form
+under the terms of Sections 1 and 2 above provided that you accompany
+it with the complete corresponding machine-readable source code, which
+must be distributed under the terms of Sections 1 and 2 above on a
+medium customarily used for software interchange.
+
+  If distribution of object code is made by offering access to copy
+from a designated place, then offering equivalent access to copy the
+source code from the same place satisfies the requirement to
+distribute the source code, even though third parties are not
+compelled to copy the source along with the object code.
+
+  5. A program that contains no derivative of any portion of the
+Library, but is designed to work with the Library by being compiled or
+linked with it, is called a "work that uses the Library".  Such a
+work, in isolation, is not a derivative work of the Library, and
+therefore falls outside the scope of this License.
+
+  However, linking a "work that uses the Library" with the Library
+creates an executable that is a derivative of the Library (because it
+contains portions of the Library), rather than a "work that uses the
+library".  The executable is therefore covered by this License.
+Section 6 states terms for distribution of such executables.
+
+  When a "work that uses the Library" uses material from a header file
+that is part of the Library, the object code for the work may be a
+derivative work of the Library even though the source code is not.
+Whether this is true is especially significant if the work can be
+linked without the Library, or if the work is itself a library.  The
+threshold for this to be true is not precisely defined by law.
+
+  If such an object file uses only numerical parameters, data
+structure layouts and accessors, and small macros and small inline
+functions (ten lines or less in length), then the use of the object
+file is unrestricted, regardless of whether it is legally a derivative
+work.  (Executables containing this object code plus portions of the
+Library will still fall under Section 6.)
+
+  Otherwise, if the work is a derivative of the Library, you may
+distribute the object code for the work under the terms of Section 6.
+Any executables containing that work also fall under Section 6,
+whether or not they are linked directly with the Library itself.
+
+  6. As an exception to the Sections above, you may also combine or
+link a "work that uses the Library" with the Library to produce a
+work containing portions of the Library, and distribute that work
+under terms of your choice, provided that the terms permit
+modification of the work for the customer's own use and reverse
+engineering for debugging such modifications.
+
+  You must give prominent notice with each copy of the work that the
+Library is used in it and that the Library and its use are covered by
+this License.  You must supply a copy of this License.  If the work
+during execution displays copyright notices, you must include the
+copyright notice for the Library among them, as well as a reference
+directing the user to the copy of this License.  Also, you must do one
+of these things:
+
+    a) Accompany the work with the complete corresponding
+    machine-readable source code for the Library including whatever
+    changes were used in the work (which must be distributed under
+    Sections 1 and 2 above); and, if the work is an executable linked
+    with the Library, with the complete machine-readable "work that
+    uses the Library", as object code and/or source code, so that the
+    user can modify the Library and then relink to produce a modified
+    executable containing the modified Library.  (It is understood
+    that the user who changes the contents of definitions files in the
+    Library will not necessarily be able to recompile the application
+    to use the modified definitions.)
+
+    b) Use a suitable shared library mechanism for linking with the
+    Library.  A suitable mechanism is one that (1) uses at run time a
+    copy of the library already present on the user's computer system,
+    rather than copying library functions into the executable, and (2)
+    will operate properly with a modified version of the library, if
+    the user installs one, as long as the modified version is
+    interface-compatible with the version that the work was made with.
+
+    c) Accompany the work with a written offer, valid for at
+    least three years, to give the same user the materials
+    specified in Subsection 6a, above, for a charge no more
+    than the cost of performing this distribution.
+
+    d) If distribution of the work is made by offering access to copy
+    from a designated place, offer equivalent access to copy the above
+    specified materials from the same place.
+
+    e) Verify that the user has already received a copy of these
+    materials or that you have already sent this user a copy.
+
+  For an executable, the required form of the "work that uses the
+Library" must include any data and utility programs needed for
+reproducing the executable from it.  However, as a special exception,
+the materials to be distributed need not include anything that is
+normally distributed (in either source or binary form) with the major
+components (compiler, kernel, and so on) of the operating system on
+which the executable runs, unless that component itself accompanies
+the executable.
+
+  It may happen that this requirement contradicts the license
+restrictions of other proprietary libraries that do not normally
+accompany the operating system.  Such a contradiction means you cannot
+use both them and the Library together in an executable that you
+distribute.
+
+  7. You may place library facilities that are a work based on the
+Library side-by-side in a single library together with other library
+facilities not covered by this License, and distribute such a combined
+library, provided that the separate distribution of the work based on
+the Library and of the other library facilities is otherwise
+permitted, and provided that you do these two things:
+
+    a) Accompany the combined library with a copy of the same work
+    based on the Library, uncombined with any other library
+    facilities.  This must be distributed under the terms of the
+    Sections above.
+
+    b) Give prominent notice with the combined library of the fact
+    that part of it is a work based on the Library, and explaining
+    where to find the accompanying uncombined form of the same work.
+
+  8. You may not copy, modify, sublicense, link with, or distribute
+the Library except as expressly provided under this License.  Any
+attempt otherwise to copy, modify, sublicense, link with, or
+distribute the Library is void, and will automatically terminate your
+rights under this License.  However, parties who have received copies,
+or rights, from you under this License will not have their licenses
+terminated so long as such parties remain in full compliance.
+
+  9. You are not required to accept this License, since you have not
+signed it.  However, nothing else grants you permission to modify or
+distribute the Library or its derivative works.  These actions are
+prohibited by law if you do not accept this License.  Therefore, by
+modifying or distributing the Library (or any work based on the
+Library), you indicate your acceptance of this License to do so, and
+all its terms and conditions for copying, distributing or modifying
+the Library or works based on it.
+
+  10. Each time you redistribute the Library (or any work based on the
+Library), the recipient automatically receives a license from the
+original licensor to copy, distribute, link with or modify the Library
+subject to these terms and conditions.  You may not impose any further
+restrictions on the recipients' exercise of the rights granted herein.
+You are not responsible for enforcing compliance by third parties with
+this License.
+
+  11. If, as a consequence of a court judgment or allegation of patent
+infringement or for any other reason (not limited to patent issues),
+conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License.  If you cannot
+distribute so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you
+may not distribute the Library at all.  For example, if a patent
+license would not permit royalty-free redistribution of the Library by
+all those who receive copies directly or indirectly through you, then
+the only way you could satisfy both it and this License would be to
+refrain entirely from distribution of the Library.
+
+If any portion of this section is held invalid or unenforceable under any
+particular circumstance, the balance of the section is intended to apply,
+and the section as a whole is intended to apply in other circumstances.
+
+It is not the purpose of this section to induce you to infringe any
+patents or other property right claims or to contest validity of any
+such claims; this section has the sole purpose of protecting the
+integrity of the free software distribution system which is
+implemented by public license practices.  Many people have made
+generous contributions to the wide range of software distributed
+through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing
+to distribute software through any other system and a licensee cannot
+impose that choice.
+
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
+
+  12. If the distribution and/or use of the Library is restricted in
+certain countries either by patents or by copyrighted interfaces, the
+original copyright holder who places the Library under this License may add
+an explicit geographical distribution limitation excluding those countries,
+so that distribution is permitted only in or among countries not thus
+excluded.  In such case, this License incorporates the limitation as if
+written in the body of this License.
+
+  13. The Free Software Foundation may publish revised and/or new
+versions of the Lesser General Public License from time to time.
+Such new versions will be similar in spirit to the present version,
+but may differ in detail to address new problems or concerns.
+
+Each version is given a distinguishing version number.  If the Library
+specifies a version number of this License which applies to it and
+"any later version", you have the option of following the terms and
+conditions either of that version or of any later version published by
+the Free Software Foundation.  If the Library does not specify a
+license version number, you may choose any version ever published by
+the Free Software Foundation.
+
+  14. If you wish to incorporate parts of the Library into other free
+programs whose distribution conditions are incompatible with these,
+write to the author to ask for permission.  For software which is
+copyrighted by the Free Software Foundation, write to the Free
+Software Foundation; we sometimes make exceptions for this.  Our
+decision will be guided by the two goals of preserving the free status
+of all derivatives of our free software and of promoting the sharing
+and reuse of software generally.
+
+                            NO WARRANTY
+
+  15. BECAUSE THE LIBRARY IS LICENSED FREE OF CHARGE, THERE IS NO
+WARRANTY FOR THE LIBRARY, TO THE EXTENT PERMITTED BY APPLICABLE LAW.
+EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR
+OTHER PARTIES PROVIDE THE LIBRARY "AS IS" WITHOUT WARRANTY OF ANY
+KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE
+LIBRARY IS WITH YOU.  SHOULD THE LIBRARY PROVE DEFECTIVE, YOU ASSUME
+THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+  16. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN
+WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY
+AND/OR REDISTRIBUTE THE LIBRARY AS PERMITTED ABOVE, BE LIABLE TO YOU
+FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR
+CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE
+LIBRARY (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
+RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
+FAILURE OF THE LIBRARY TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
+SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+DAMAGES.
+
+                     END OF TERMS AND CONDITIONS
+
+           How to Apply These Terms to Your New Libraries
+
+  If you develop a new library, and you want it to be of the greatest
+possible use to the public, we recommend making it free software that
+everyone can redistribute and change.  You can do so by permitting
+redistribution under these terms (or, alternatively, under the terms of the
+ordinary General Public License).
+
+  To apply these terms, attach the following notices to the library.  It is
+safest to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least the
+"copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the library's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+
+Also add information on how to contact you by electronic and paper mail.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the library, if
+necessary.  Here is a sample; alter the names:
+
+  Yoyodyne, Inc., hereby disclaims all copyright interest in the
+  library `Frob' (a library for tweaking knobs) written by James Random Hacker.
+
+  <signature of Ty Coon>, 1 April 1990
+  Ty Coon, President of Vice
+
+That's all there is to it!
+
+----------------------------------------------------------------------
+
+The bundled SHA1 collision detection code is licensed under the MIT license:
+
+MIT License
+
+Copyright (c) 2017:
+    Marc Stevens
+    Cryptology Group
+    Centrum Wiskunde & Informatica
+    P.O. Box 94079, 1090 GB Amsterdam, Netherlands
+    marc@marc-stevens.nl
+
+    Dan Shumow
+    Microsoft Research
+    danshu@microsoft.com
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/libgit2-sys/libgit2/PROJECTS.md

diff --git a/vendor/libgit2-sys/libgit2/PROJECTS.md b/vendor/libgit2-sys/libgit2/PROJECTS.md
new file mode 100644
index 0000000..419fdcd
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/PROJECTS.md
@@ -0,0 +1,93 @@
+Projects For LibGit2
+====================
+
+So, you want to start helping out with `libgit2`? That's fantastic! We
+welcome contributions and we promise we'll try to be nice.
+
+This is a list of libgit2 related projects that new contributors can take
+on.  It includes a number of good starter projects as well as some larger
+ideas that no one is actively working on.
+
+## Before You Start
+
+Please start by reading the [README.md](README.md),
+[CONTRIBUTING.md](CONTRIBUTING.md), and [CONVENTIONS.md](CONVENTIONS.md)
+files before diving into one of these projects.  Those explain our work
+flow and coding conventions to help ensure that your work will be easily
+integrated into libgit2.
+
+Next, work through the build instructions and make sure you can clone the
+repository, compile it, and run the tests successfully.  That will make
+sure that your development environment is set up correctly and you are
+ready to start on libgit2 development.
+
+## Starter Projects
+
+These are good small projects to get started with libgit2.
+
+* Look at the `examples/` programs, find an existing one that mirrors a
+  core Git command and add a missing command-line option.  There are many
+  gaps right now and this helps demonstrate how to use the library.  Here
+  are some specific ideas (though there are many more):
+    * Fix the `examples/diff.c` implementation of the `-B`
+      (a.k.a. `--break-rewrites`) command line option to actually look for
+      the optional `[<n>][/<m>]` configuration values. There is an
+      existing comment that reads `/* TODO: parse thresholds */`. The
+      trick to this one will be doing it in a manner that is clean and
+      simple, but still handles the various cases correctly (e.g. `-B/70%`
+      is apparently a legal setting).
+    * As an extension to the matching idea for `examples/log.c`, add the
+      `-i` option to use `strcasestr()` for matches.
+    * For `examples/log.c`, implement the `--first-parent` option now that
+      libgit2 supports it in the revwalk API.
+* Pick a Git command that is not already emulated in `examples/` and write
+  a new example that mirrors the behavior.  Examples don't have to be
+  perfect emulations, but should demonstrate how to use the libgit2 APIs
+  to get results that are similar to Git commands.  This lets you (and us)
+  easily exercise a particular facet of the API and measure compatibility
+  and feature parity with core git.
+* Submit a PR to clarify documentation! While we do try to document all of
+  the APIs, your fresh eyes on the documentation will find areas that are
+  confusing much more easily.
+
+If none of these appeal to you, take a look at our issues list to see if
+there are any unresolved issues you'd like to jump in on.
+
+## Larger Projects
+
+These are ideas for larger projects mostly taken from our backlog of
+[Issues](https://github.com/libgit2/libgit2/issues).  Please don't dive
+into one of these as a first project for libgit2 - we'd rather get to
+know you first by successfully shipping your work on one of the smaller
+projects above.
+
+Some of these projects are broken down into subprojects and/or have
+some incremental steps listed towards the larger goal.  Those steps
+might make good smaller projects by themselves.
+
+* Port part of the Git test suite to run against the command line emulation
+  in `examples/`
+    * Pick a Git command that is emulated in our `examples/` area
+    * Extract the Git tests that exercise that command
+    * Convert the tests to call our emulation
+    * These tests could go in `examples/tests/`...
+* Add hooks API to enumerate and manage hooks (not run them at this point)
+    * Enumeration of available hooks
+    * Lookup API to see which hooks have a script and get the script
+    * Read/write API to load a hook script and write a hook script
+    * Eventually, callback API to invoke a hook callback when libgit2
+      executes the action in question
+* Isolate logic of ignore evaluation into a standalone API
+* Upgrade internal libxdiff code to latest from core Git
+* Tree builder improvements:
+    * Extend to allow building a tree hierarchy
+* Apply-patch API
+* Add a patch editing API to enable "git add -p" type operations
+* Textconv API to filter binary data before generating diffs (something
+  like the current Filter API, probably).
+* Performance profiling and improvement
+* Support "git replace" ref replacements
+* Include conflicts in diff results and in status
+    * GIT_DELTA_CONFLICT for items in conflict (with multiple files)
+    * Appropriate flags for status
+* Support sparse checkout (i.e. "core.sparsecheckout" and ".git/info/sparse-checkout")

vendor/libgit2-sys/libgit2/README.md

diff --git a/vendor/libgit2-sys/libgit2/README.md b/vendor/libgit2-sys/libgit2/README.md
new file mode 100644
index 0000000..9fe99d8
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/README.md
@@ -0,0 +1,359 @@
+libgit2 - the Git linkable library
+==================================
+
+[![Travis Build Status](https://secure.travis-ci.org/libgit2/libgit2.svg?branch=master)](http://travis-ci.org/libgit2/libgit2)
+[![AppVeyor Build Status](https://ci.appveyor.com/api/projects/status/xvof5b4t5480a2q3/branch/master?svg=true)](https://ci.appveyor.com/project/libgit2/libgit2/branch/master)
+[![Coverity Scan Build Status](https://scan.coverity.com/projects/639/badge.svg)](https://scan.coverity.com/projects/639)
+
+`libgit2` is a portable, pure C implementation of the Git core methods
+provided as a linkable library with a solid API, allowing to build Git
+functionality into your application.  Language bindings like
+[Rugged](https://github.com/libgit2/rugged) (Ruby),
+[LibGit2Sharp](https://github.com/libgit2/libgit2sharp) (.NET),
+[pygit2](http://www.pygit2.org/) (Python) and
+[NodeGit](http://nodegit.org) (Node) allow you to build Git tooling
+in your favorite language.
+
+`libgit2` is used to power Git GUI clients like
+[GitKraken](https://gitkraken.com/) and [gmaster](https://gmaster.io/)
+and on Git hosting providers like [GitHub](https://github.com/),
+[GitLab](https://gitlab.com/) and
+[Visual Studio Team Services](https://visualstudio.com/team-services/).
+We perform the merge every time you click "merge pull request".
+
+`libgit2` is licensed under a **very permissive license** (GPLv2 with a special
+Linking Exception).  This basically means that you can link it (unmodified)
+with any kind of software without having to release its source code.
+Additionally, the example code has been released to the public domain (see the
+[separate license](examples/COPYING) for more information).
+
+Quick Start
+===========
+
+**Prerequisites** for building libgit2:
+
+1. [CMake](https://cmake.org/), and is recommended to be installed into
+   your `PATH`.
+2. [Python](https://www.python.org) is used by our test framework, and
+   should be installed into your `PATH`.
+3. C compiler: libgit2 is C90 and should compile on most compilers.
+   * Windows: Visual Studio is recommended
+   * Mac: Xcode is recommended
+   * Unix: gcc or clang is recommended.
+
+**Build**
+
+1. Create a build directory beneath the libgit2 source directory, and change
+   into it: `mkdir build && cd build`
+2. Create the cmake build environment: `cmake ..`
+3. Build libgit2: `cmake --build .`
+
+Trouble with these steps?  Read `TROUBLESHOOTING.md`.  More detailed build
+guidance is available below.
+
+Getting Help
+============
+
+**Join us on Slack**
+
+Visit [slack.libgit2.org](http://slack.libgit2.org/) to sign up, then join
+us in `#libgit2`.  If you prefer IRC, you can also point your client to our
+slack channel once you've registered.
+
+**Getting Help**
+
+If you have questions about the library, please be sure to check out the
+[API documentation](http://libgit2.github.com/libgit2/).  If you still have
+questions, reach out to us on Slack or post a question on 
+[StackOverflow](http://stackoverflow.com/questions/tagged/libgit2) (with the `libgit2` tag).
+
+**Reporting Bugs**
+
+Please open a [GitHub Issue](https://github.com/libgit2/libgit2/issues) and
+include as much information as possible.  If possible, provide sample code
+that illustrates the problem you're seeing.  If you're seeing a bug only
+on a specific repository, please provide a link to it if possible.
+
+We ask that you not open a GitHub Issue for help, only for bug reports.
+
+**Reporting Security Issues**
+
+In case you think to have found a security issue with libgit2, please do not
+open a public issue.  Instead, you can report the issue to the private mailing
+list [security@libgit2.com](mailto:security@libgit2.com).
+
+What It Can Do
+==============
+
+libgit2 provides you with the ability to manage Git repositories in the
+programming language of your choice.  It's used in production to power many
+applications including GitHub.com, Plastic SCM and Visual Studio Team Services.
+
+It does not aim to replace the git tool or its user-facing commands. Some APIs
+resemble the plumbing commands as those align closely with the concepts of the
+Git system, but most commands a user would type are out of scope for this
+library to implement directly.
+
+The library provides:
+
+* SHA conversions, formatting and shortening
+* abstracted ODB backend system
+* commit, tag, tree and blob parsing, editing, and write-back
+* tree traversal
+* revision walking
+* index file (staging area) manipulation
+* reference management (including packed references)
+* config file management
+* high level repository management
+* thread safety and reentrancy
+* descriptive and detailed error messages
+* ...and more (over 175 different API calls)
+
+As libgit2 is purely a consumer of the Git system, we have to
+adjust to changes made upstream. This has two major consequences:
+
+* Some changes may require us to change provided interfaces. While we try to
+  implement functions in a generic way so that no future changes are required,
+  we cannot promise a completely stable API.
+* As we have to keep up with changes in behavior made upstream, we may lag
+  behind in some areas. We usually to document these incompatibilities in our
+  issue tracker with the label "git change".
+
+Optional dependencies
+=====================
+
+While the library provides git functionality without the need for
+dependencies, it can make use of a few libraries to add to it:
+
+- pthreads (non-Windows) to enable threadsafe access as well as multi-threaded pack generation
+- OpenSSL (non-Windows) to talk over HTTPS and provide the SHA-1 functions
+- LibSSH2 to enable the SSH transport
+- iconv (OSX) to handle the HFS+ path encoding peculiarities
+
+Initialization
+===============
+
+The library needs to keep track of some global state. Call
+
+    git_libgit2_init();
+
+before calling any other libgit2 functions. You can call this function many times. A matching number of calls to
+
+    git_libgit2_shutdown();
+
+will free the resources.  Note that if you have worker threads, you should
+call `git_libgit2_shutdown` *after* those threads have exited.  If you
+require assistance coordinating this, simply have the worker threads call
+`git_libgit2_init` at startup and `git_libgit2_shutdown` at shutdown.
+
+Threading
+=========
+
+See [THREADING](THREADING.md) for information
+
+Conventions
+===========
+
+See [CONVENTIONS](CONVENTIONS.md) for an overview of the external
+and internal API/coding conventions we use.
+
+Building libgit2 - Using CMake
+==============================
+
+Building
+--------
+
+`libgit2` builds cleanly on most platforms without any external dependencies.
+Under Unix-like systems, like Linux, \*BSD and Mac OS X, libgit2 expects `pthreads` to be available;
+they should be installed by default on all systems. Under Windows, libgit2 uses the native Windows API
+for threading.
+
+The `libgit2` library is built using [CMake](<https://cmake.org/>) (version 2.8 or newer) on all platforms.
+
+On most systems you can build the library using the following commands
+
+	$ mkdir build && cd build
+	$ cmake ..
+	$ cmake --build .
+
+Alternatively you can point the CMake GUI tool to the CMakeLists.txt file and generate platform specific build project or IDE workspace.
+
+Running Tests
+-------------
+
+Once built, you can run the tests from the `build` directory with the command
+
+	$ ctest -V
+
+Alternatively you can run the test suite directly using,
+
+	$ ./libgit2_clar
+
+Invoking the test suite directly is useful because it allows you to execute
+individual tests, or groups of tests using the `-s` flag.  For example, to
+run the index tests:
+
+    $ ./libgit2_clar -sindex
+
+To run a single test named `index::racy::diff`, which corresponds to the test
+function (`test_index_racy__diff`)[https://github.com/libgit2/libgit2/blob/master/tests/index/racy.c#L23]:
+
+    $ ./libgit2_clar -sindex::racy::diff
+
+The test suite will print a `.` for every passing test, and an `F` for any
+failing test.  An `S` indicates that a test was skipped because it is not
+applicable to your platform or is particularly expensive.
+
+**Note:** There should be _no_ failing tests when you build an unmodified
+source tree from a [release](https://github.com/libgit2/libgit2/releases),
+or from the [master branch](https://github.com/libgit2/libgit2/tree/master).
+Please contact us or [open an issue](https://github.com/libgit2/libgit2/issues)
+if you see test failures.
+
+Installation
+------------
+
+To install the library you can specify the install prefix by setting:
+
+	$ cmake .. -DCMAKE_INSTALL_PREFIX=/install/prefix
+	$ cmake --build . --target install
+
+Advanced Usage
+--------------
+
+For more advanced use or questions about CMake please read <https://cmake.org/Wiki/CMake_FAQ>.
+
+The following CMake variables are declared:
+
+- `BIN_INSTALL_DIR`: Where to install binaries to.
+- `LIB_INSTALL_DIR`: Where to install libraries to.
+- `INCLUDE_INSTALL_DIR`: Where to install headers to.
+- `BUILD_SHARED_LIBS`: Build libgit2 as a Shared Library (defaults to ON)
+- `BUILD_CLAR`: Build [Clar](https://github.com/vmg/clar)-based test suite (defaults to ON)
+- `THREADSAFE`: Build libgit2 with threading support (defaults to ON)
+- `STDCALL`: Build libgit2 as `stdcall`. Turn off for `cdecl` (Windows; defaults to ON)
+
+Compiler and linker options
+---------------------------
+
+CMake lets you specify a few variables to control the behavior of the
+compiler and linker. These flags are rarely used but can be useful for
+64-bit to 32-bit cross-compilation.
+
+- `CMAKE_C_FLAGS`: Set your own compiler flags
+- `CMAKE_FIND_ROOT_PATH`: Override the search path for libraries
+- `ZLIB_LIBRARY`, `OPENSSL_SSL_LIBRARY` AND `OPENSSL_CRYPTO_LIBRARY`:
+Tell CMake where to find those specific libraries
+
+MacOS X
+-------
+
+If you want to build a universal binary for Mac OS X, CMake sets it
+all up for you if you use `-DCMAKE_OSX_ARCHITECTURES="i386;x86_64"`
+when configuring.
+
+Android
+-------
+
+Extract toolchain from NDK using, `make-standalone-toolchain.sh` script.
+Optionally, crosscompile and install OpenSSL inside of it. Then create CMake
+toolchain file that configures paths to your crosscompiler (substitute `{PATH}`
+with full path to the toolchain):
+
+	SET(CMAKE_SYSTEM_NAME Linux)
+	SET(CMAKE_SYSTEM_VERSION Android)
+
+	SET(CMAKE_C_COMPILER   {PATH}/bin/arm-linux-androideabi-gcc)
+	SET(CMAKE_CXX_COMPILER {PATH}/bin/arm-linux-androideabi-g++)
+	SET(CMAKE_FIND_ROOT_PATH {PATH}/sysroot/)
+
+	SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+	SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+	SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+
+Add `-DCMAKE_TOOLCHAIN_FILE={pathToToolchainFile}` to cmake command
+when configuring.
+
+Language Bindings
+==================================
+
+Here are the bindings to libgit2 that are currently available:
+
+* C++
+    * libqgit2, Qt bindings <https://projects.kde.org/projects/playground/libs/libqgit2/repository/>
+* Chicken Scheme
+    * chicken-git <https://wiki.call-cc.org/egg/git>
+* D
+    * dlibgit <https://github.com/s-ludwig/dlibgit>
+* Delphi
+    * GitForDelphi <https://github.com/libgit2/GitForDelphi>
+* Erlang
+    * Geef <https://github.com/carlosmn/geef>
+* Go
+    * git2go <https://github.com/libgit2/git2go>
+* GObject
+    * libgit2-glib <https://wiki.gnome.org/Projects/Libgit2-glib>
+* Guile
+	* Guile-Git <https://gitlab.com/guile-git/guile-git>
+* Haskell
+    * hgit2 <https://github.com/jwiegley/gitlib>
+* Java
+    * Jagged <https://github.com/ethomson/jagged>
+* Julia
+    * LibGit2.jl <https://github.com/jakebolewski/LibGit2.jl>
+* Lua
+    * luagit2 <https://github.com/libgit2/luagit2>
+* .NET
+    * libgit2sharp <https://github.com/libgit2/libgit2sharp>
+* Node.js
+    * nodegit <https://github.com/nodegit/nodegit>
+* Objective-C
+    * objective-git <https://github.com/libgit2/objective-git>
+* OCaml
+    * ocaml-libgit2 <https://github.com/fxfactorial/ocaml-libgit2>
+* Parrot Virtual Machine
+    * parrot-libgit2 <https://github.com/letolabs/parrot-libgit2>
+* Perl
+    * Git-Raw <https://github.com/jacquesg/p5-Git-Raw>
+* PHP
+    * php-git <https://github.com/libgit2/php-git>
+* PowerShell
+    * PSGit <https://github.com/PoshCode/PSGit>
+* Python
+    * pygit2 <https://github.com/libgit2/pygit2>
+* R
+    * git2r <https://github.com/ropensci/git2r>
+* Ruby
+    * Rugged <https://github.com/libgit2/rugged>
+* Rust
+    * git2-rs <https://github.com/alexcrichton/git2-rs>
+* Swift
+    * SwiftGit2 <https://github.com/SwiftGit2/SwiftGit2>
+* Vala
+    * libgit2.vapi <https://github.com/apmasell/vapis/blob/master/libgit2.vapi>
+
+If you start another language binding to libgit2, please let us know so
+we can add it to the list.
+
+How Can I Contribute?
+==================================
+
+We welcome new contributors!  We have a number of issues marked as
+["up for grabs"](https://github.com/libgit2/libgit2/issues?q=is%3Aissue+is%3Aopen+label%3A%22up+for+grabs%22)
+and
+["easy fix"](https://github.com/libgit2/libgit2/issues?utf8=✓&q=is%3Aissue+is%3Aopen+label%3A%22easy+fix%22)
+that are good places to jump in and get started.  There's much more detailed
+information in our list of [outstanding projects](PROJECTS.md).
+
+Please be sure to check the [contribution guidelines](CONTRIBUTING.md) to
+understand our workflow, and the libgit2 [coding conventions](CONVENTIONS.md).
+
+License
+==================================
+
+`libgit2` is under GPL2 **with linking exception**. This means you can link to
+and use the library from any program, proprietary or open source; paid or
+gratis.  However, if you modify libgit2 itself, you must distribute the
+source to your modified version of libgit2.
+
+See the [COPYING file](COPYING) for the full license text.

vendor/libgit2-sys/libgit2/THREADING.md

diff --git a/vendor/libgit2-sys/libgit2/THREADING.md b/vendor/libgit2-sys/libgit2/THREADING.md
new file mode 100644
index 0000000..430bca8
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/THREADING.md
@@ -0,0 +1,115 @@
+Threads in libgit2
+==================
+
+You may safely use any libgit2 object from any thread, though there
+may be issues depending on the cryptographic libraries libgit2 or its
+dependencies link to (more on this later). For libgit2 itself,
+provided you take the following into consideration you won't run into
+issues:
+
+Sharing objects
+---------------
+
+Use an object from a single thread at a time. Most data structures do
+not guard against concurrent access themselves. This is because they
+are rarely used in isolation and it makes more sense to synchronize
+access via a larger lock or similar mechanism.
+
+There are some objects which are read-only/immutable and are thus safe
+to share across threads, such as references and configuration
+snapshots.
+
+Error messages
+--------------
+
+The error message is thread-local. The `giterr_last()` call must
+happen on the same thread as the error in order to get the
+message. Often this will be the case regardless, but if you use
+something like the [GCD](http://en.wikipedia.org/wiki/Grand_Central_Dispatch)
+on Mac OS X (where code is executed on an arbitrary thread), the code
+must make sure to retrieve the error code on the thread where the error
+happened.
+
+Threads and cryptographic libraries
+=======================================
+
+On Windows
+----------
+
+When built as a native Windows DLL, libgit2 uses WinCNG and WinHTTP,
+both of which are thread-safe. You do not need to do anything special.
+
+When using libssh2 which itself uses WinCNG, there are no special
+steps necessary. If you are using a MinGW or similar environment where
+libssh2 uses OpenSSL or libgcrypt, then the general case affects
+you.
+
+On Mac OS X
+-----------
+
+By default we use libcurl to perform the encryption. The
+system-provided libcurl uses SecureTransport, so no special steps are
+necessary. If you link against another libcurl (e.g. from homebrew)
+refer to the general case.
+
+If the option to use libcurl was deactivated, the library makes use of
+CommonCrypto and SecureTransport for cryptographic support. These are
+thread-safe and you do not need to do anything special.
+
+Note that libssh2 may still use OpenSSL itself. In that case, the
+general case still affects you if you use ssh.
+
+General Case
+------------
+
+If it's available, by default we use libcurl to provide HTTP tunneling support,
+which may be linked against a number of cryptographic libraries and has its
+own
+[recommendations for thread safety](https://curl.haxx.se/libcurl/c/threadsafe.html).
+
+If there are no alternative TLS implementations (currently only
+SecureTransport), libgit2 uses OpenSSL in order to use HTTPS as a transport.
+OpenSSL is thread-safe starting at version 1.1.0. If your copy of libgit2 is
+linked against that version, you do not need to take any further steps.
+
+Older versions of OpenSSL are made to be thread-implementation agnostic, and the
+users of the library must set which locking function it should use. libgit2
+cannot know what to set as the user of libgit2 may also be using OpenSSL independently and
+the locking settings must then live outside the lifetime of libgit2.
+
+Even if libgit2 doesn't use OpenSSL directly, OpenSSL can still be used by
+libssh2 or libcurl depending on the configuration. If OpenSSL is used by
+more than one library, you only need to set up threading for OpenSSL once.
+
+If libgit2 is linked against OpenSSL, it provides a last-resort convenience function
+`git_openssl_set_locking()` (available in `sys/openssl.h`) to use the
+platform-native mutex mechanisms to perform the locking, which you can use
+if you do not want to use OpenSSL outside of libgit2, or you
+know that libgit2 will outlive the rest of the operations. It is then not
+safe to use OpenSSL multi-threaded after libgit2's shutdown function
+has been called.  Note `git_openssl_set_locking()` only works if
+libgit2 uses OpenSSL directly - if OpenSSL is only used as a dependency
+of libssh2 or libcurl as described above, `git_openssl_set_locking()` is a no-op.
+
+If your programming language offers a package/bindings for OpenSSL,
+you should very strongly prefer to use that in order to set up
+locking, as they provide a level of coordination which is impossible
+when using this function.
+
+See the
+[OpenSSL documentation](https://www.openssl.org/docs/crypto/threads.html)
+on threading for more details, and http://trac.libssh2.org/wiki/MultiThreading
+for a specific example of providing the threading callbacks.
+
+libssh2 may be linked against OpenSSL or libgcrypt. If it uses OpenSSL,
+see the above paragraphs. If it uses libgcrypt, then you need to
+set up its locking before using it multi-threaded. libgit2 has no
+direct connection to libgcrypt and thus has no convenience functions for
+it (but libgcrypt has macros). Read libgcrypt's
+[threading documentation for more information](http://www.gnupg.org/documentation/manuals/gcrypt/Multi_002dThreading.html)
+
+It is your responsibility as an application author or packager to know
+what your dependencies are linked against and to take the appropriate
+steps to ensure the cryptographic libraries are thread-safe. We agree
+that this situation is far from ideal but at this time it is something
+the application authors need to deal with.

vendor/libgit2-sys/libgit2/TROUBLESHOOTING.md

diff --git a/vendor/libgit2-sys/libgit2/TROUBLESHOOTING.md b/vendor/libgit2-sys/libgit2/TROUBLESHOOTING.md
new file mode 100644
index 0000000..085fff8
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/TROUBLESHOOTING.md
@@ -0,0 +1,13 @@
+Troubleshooting libgit2 Problems
+================================
+
+CMake Failures
+--------------
+
+* **`Asked for OpenSSL TLS backend, but it wasn't found`**
+  CMake cannot find your SSL/TLS libraries.  By default, libgit2 always
+  builds with HTTPS support, and you are encouraged to install the
+  OpenSSL libraries for your system (eg, `apt-get install libssl-dev`).
+
+  For development, if you simply want to disable HTTPS support entirely,
+  pass the `-DUSE_HTTPS=OFF` argument to `cmake` when configuring it.

vendor/libgit2-sys/libgit2/api.docurium

diff --git a/vendor/libgit2-sys/libgit2/api.docurium b/vendor/libgit2-sys/libgit2/api.docurium
new file mode 100644
index 0000000..9e17817
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/api.docurium
@@ -0,0 +1,13 @@
+{
+ "name":   "libgit2",
+ "github": "libgit2/libgit2",
+ "input":  "include/git2",
+ "prefix": "git_",
+ "output": "docs",
+ "branch": "gh-pages",
+ "examples": "examples",
+ "legacy":  {
+    "input": {"src/git": ["v0.1.0"],
+              "src/git2": ["v0.2.0", "v0.3.0"]}
+  }
+}

vendor/libgit2-sys/libgit2/appveyor.yml

diff --git a/vendor/libgit2-sys/libgit2/appveyor.yml b/vendor/libgit2-sys/libgit2/appveyor.yml
new file mode 100644
index 0000000..f76830c
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/appveyor.yml
@@ -0,0 +1,60 @@
+version: '{build}'
+branches:
+  only:
+  - master
+  - appveyor
+  - /^maint.*/
+environment:
+  GITTEST_INVASIVE_FS_STRUCTURE: 1
+  GITTEST_INVASIVE_FS_SIZE: 1
+
+  matrix:
+  - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
+    GENERATOR: "Visual Studio 10 2010"
+    ARCH: 32
+  - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
+    GENERATOR: "Visual Studio 10 2010 Win64"
+    ARCH: 64
+  - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+    GENERATOR: "Visual Studio 14 2015"
+    ARCH: 32
+  - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+    GENERATOR: "Visual Studio 14 2015 Win64"
+    ARCH: 64
+  - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+    GENERATOR: "MSYS Makefiles"
+    ARCH: i686 # this is for 32-bit MinGW-w64
+  - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+    GENERATOR: "MSYS Makefiles"
+    ARCH: 64
+cache:
+- i686-4.9.2-release-win32-sjlj-rt_v3-rev1.7z
+- x86_64-4.9.2-release-win32-seh-rt_v3-rev1.7z
+
+build_script:
+- ps: |
+    mkdir build
+    cd build
+    if ($env:GENERATOR -ne "MSYS Makefiles") {
+      cmake -D ENABLE_TRACE=ON -D BUILD_CLAR=ON -D BUILD_EXAMPLES=ON -D MSVC_CRTDBG=ON .. -G"$env:GENERATOR"
+      cmake --build . --config Debug
+    }
+- cmd: |
+    if "%GENERATOR%"=="MSYS Makefiles" (C:\MinGW\msys\1.0\bin\sh --login /c/projects/libgit2/script/appveyor-mingw.sh)
+test_script:
+- ps: |
+    # Disable DHE key exchange to fix intermittent build failures ("A buffer
+    # provided was too small") due to SChannel bug. See e.g.
+    # - https://github.com/aws/aws-sdk-cpp/issues/671
+    # - https://github.com/dotnet/corefx/issues/7812
+    New-Item HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\KeyExchangeAlgorithms\Diffie-Hellman -Force | New-ItemProperty -Name Enabled -Value 0 -Force
+    $ErrorActionPreference="Stop"
+    Start-FileDownload https://github.com/ethomson/poxyproxy/releases/download/v0.1.0/poxyproxy-0.1.0.jar -FileName poxyproxy.jar
+    # Run this early so we know it's ready by the time we need it
+    $proxyJob = Start-Job { java -jar $Env:APPVEYOR_BUILD_FOLDER\build\poxyproxy.jar -d --port 8080 --credentials foo:bar }
+    ctest -V -R libgit2_clar
+    Receive-Job -Job $proxyJob
+    $env:GITTEST_REMOTE_PROXY_URL = "localhost:8080"
+    $env:GITTEST_REMOTE_PROXY_USER = "foo"
+    $env:GITTEST_REMOTE_PROXY_PASS = "bar"
+    ctest -V -R libgit2_clar-proxy_credentials

vendor/libgit2-sys/libgit2/cmake/Modules/AddCFlagIfSupported.cmake

diff --git a/vendor/libgit2-sys/libgit2/cmake/Modules/AddCFlagIfSupported.cmake b/vendor/libgit2-sys/libgit2/cmake/Modules/AddCFlagIfSupported.cmake
new file mode 100644
index 0000000..67fc895
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/cmake/Modules/AddCFlagIfSupported.cmake
@@ -0,0 +1,16 @@
+# - Append compiler flag to CMAKE_C_FLAGS if compiler supports it
+# ADD_C_FLAG_IF_SUPPORTED(<flag>)
+#  <flag> - the compiler flag to test
+# This internally calls the CHECK_C_COMPILER_FLAG macro.
+
+INCLUDE(CheckCCompilerFlag)
+
+MACRO(ADD_C_FLAG_IF_SUPPORTED _FLAG)
+	STRING(TOUPPER ${_FLAG} UPCASE)
+	STRING(REGEX REPLACE "^-" "" UPCASE_PRETTY ${UPCASE}) 
+	CHECK_C_COMPILER_FLAG(${_FLAG} IS_${UPCASE_PRETTY}_SUPPORTED)
+
+	IF(IS_${UPCASE_PRETTY}_SUPPORTED)
+		SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${_FLAG}")
+	ENDIF()
+ENDMACRO()

vendor/libgit2-sys/libgit2/cmake/Modules/EnableWarnings.cmake

diff --git a/vendor/libgit2-sys/libgit2/cmake/Modules/EnableWarnings.cmake b/vendor/libgit2-sys/libgit2/cmake/Modules/EnableWarnings.cmake
new file mode 100644
index 0000000..e7d7d39
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/cmake/Modules/EnableWarnings.cmake
@@ -0,0 +1,14 @@
+MACRO(ENABLE_WARNINGS flag)
+	IF(ENABLE_WERROR)
+		ADD_C_FLAG_IF_SUPPORTED(-Werror=${flag})
+	ELSE()
+		ADD_C_FLAG_IF_SUPPORTED(-W${flag})
+	ENDIF()
+ENDMACRO()
+
+MACRO(DISABLE_WARNINGS flag)
+	ADD_C_FLAG_IF_SUPPORTED(-Wno-${flag})
+	IF(ENABLE_WERROR)
+		ADD_C_FLAG_IF_SUPPORTED(-Wno-error=${flag})
+	ENDIF()
+ENDMACRO()

vendor/libgit2-sys/libgit2/cmake/Modules/FindCoreFoundation.cmake

diff --git a/vendor/libgit2-sys/libgit2/cmake/Modules/FindCoreFoundation.cmake b/vendor/libgit2-sys/libgit2/cmake/Modules/FindCoreFoundation.cmake
new file mode 100644
index 0000000..e86ccbf
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/cmake/Modules/FindCoreFoundation.cmake
@@ -0,0 +1,26 @@
+# Find CoreFoundation.framework
+# This will define :
+#
+# COREFOUNDATION_FOUND
+# COREFOUNDATION_LIBRARIES
+# COREFOUNDATION_LDFLAGS
+#
+
+FIND_PATH(COREFOUNDATION_INCLUDE_DIR NAMES CoreFoundation.h)
+FIND_LIBRARY(COREFOUNDATION_LIBRARIES NAMES CoreFoundation)
+IF (COREFOUNDATION_INCLUDE_DIR AND COREFOUNDATION_LIBRARIES)
+	IF (NOT CoreFoundation_FIND_QUIETLY)
+		MESSAGE("-- Found CoreFoundation ${COREFOUNDATION_LIBRARIES}")
+	ENDIF()
+	SET(COREFOUNDATION_FOUND TRUE)
+	SET(COREFOUNDATION_LDFLAGS "-framework CoreFoundation")
+ENDIF ()
+
+IF (CoreFoundation_FIND_REQUIRED AND NOT COREFOUNDATION_FOUND)
+	MESSAGE(FATAL "-- CoreFoundation not found")
+ENDIF()
+
+MARK_AS_ADVANCED(
+	COREFOUNDATION_INCLUDE_DIR
+	COREFOUNDATION_LIBRARIES
+)

vendor/libgit2-sys/libgit2/cmake/Modules/FindGSSAPI.cmake

diff --git a/vendor/libgit2-sys/libgit2/cmake/Modules/FindGSSAPI.cmake b/vendor/libgit2-sys/libgit2/cmake/Modules/FindGSSAPI.cmake
new file mode 100644
index 0000000..8520d35
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/cmake/Modules/FindGSSAPI.cmake
@@ -0,0 +1,324 @@
+# - Try to find GSSAPI
+# Once done this will define
+#
+#  KRB5_CONFIG - Path to krb5-config
+#  GSSAPI_ROOT_DIR - Set this variable to the root installation of GSSAPI
+#
+# Read-Only variables:
+#  GSSAPI_FLAVOR_MIT - set to TURE if MIT Kerberos has been found
+#  GSSAPI_FLAVOR_HEIMDAL - set to TRUE if Heimdal Keberos has been found
+#  GSSAPI_FOUND - system has GSSAPI
+#  GSSAPI_INCLUDE_DIR - the GSSAPI include directory
+#  GSSAPI_LIBRARIES - Link these to use GSSAPI
+#  GSSAPI_DEFINITIONS - Compiler switches required for using GSSAPI
+#
+#=============================================================================
+#  Copyright (c) 2013 Andreas Schneider <asn@cryptomilk.org>
+#
+#  Distributed under the OSI-approved BSD License (the "License");
+#  see accompanying file Copyright.txt for details.
+#
+#  This software is distributed WITHOUT ANY WARRANTY; without even the
+#  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+#  See the License for more information.
+#=============================================================================
+#
+
+find_path(GSSAPI_ROOT_DIR
+    NAMES
+        include/gssapi.h
+        include/gssapi/gssapi.h
+    HINTS
+        ${_GSSAPI_ROOT_HINTS}
+    PATHS
+        ${_GSSAPI_ROOT_PATHS}
+)
+mark_as_advanced(GSSAPI_ROOT_DIR)
+
+if (UNIX)
+    find_program(KRB5_CONFIG
+        NAMES
+            krb5-config
+        PATHS
+            ${GSSAPI_ROOT_DIR}/bin
+            /opt/local/bin)
+    mark_as_advanced(KRB5_CONFIG)
+
+    if (KRB5_CONFIG)
+        # Check if we have MIT KRB5
+        execute_process(
+            COMMAND
+                ${KRB5_CONFIG} --vendor
+            RESULT_VARIABLE
+                _GSSAPI_VENDOR_RESULT
+            OUTPUT_VARIABLE
+                _GSSAPI_VENDOR_STRING)
+
+        if (_GSSAPI_VENDOR_STRING MATCHES ".*Massachusetts.*")
+            set(GSSAPI_FLAVOR_MIT TRUE)
+        else()
+            execute_process(
+                COMMAND
+                    ${KRB5_CONFIG} --libs gssapi
+                RESULT_VARIABLE
+                    _GSSAPI_LIBS_RESULT
+                OUTPUT_VARIABLE
+                    _GSSAPI_LIBS_STRING)
+
+            if (_GSSAPI_LIBS_STRING MATCHES ".*roken.*")
+                set(GSSAPI_FLAVOR_HEIMDAL TRUE)
+            endif()
+        endif()
+
+        # Get the include dir
+        execute_process(
+            COMMAND
+                ${KRB5_CONFIG} --cflags gssapi
+            RESULT_VARIABLE
+                _GSSAPI_INCLUDE_RESULT
+            OUTPUT_VARIABLE
+                _GSSAPI_INCLUDE_STRING)
+        string(REGEX REPLACE "(\r?\n)+$" "" _GSSAPI_INCLUDE_STRING "${_GSSAPI_INCLUDE_STRING}")
+        string(REGEX REPLACE " *-I" "" _GSSAPI_INCLUDEDIR "${_GSSAPI_INCLUDE_STRING}")
+    endif()
+
+    if (NOT GSSAPI_FLAVOR_MIT AND NOT GSSAPI_FLAVOR_HEIMDAL)
+        # Check for HEIMDAL
+        find_package(PkgConfig)
+        if (PKG_CONFIG_FOUND)
+            pkg_check_modules(_GSSAPI heimdal-gssapi)
+        endif (PKG_CONFIG_FOUND)
+
+        if (_GSSAPI_FOUND)
+            set(GSSAPI_FLAVOR_HEIMDAL TRUE)
+        else()
+            find_path(_GSSAPI_ROKEN
+                NAMES
+                    roken.h
+                PATHS
+                    ${GSSAPI_ROOT_DIR}/include
+                    ${_GSSAPI_INCLUDEDIR})
+            if (_GSSAPI_ROKEN)
+                set(GSSAPI_FLAVOR_HEIMDAL TRUE)
+            endif()
+        endif ()
+    endif()
+endif (UNIX)
+
+find_path(GSSAPI_INCLUDE_DIR
+    NAMES
+        gssapi.h
+        gssapi/gssapi.h
+    PATHS
+        ${GSSAPI_ROOT_DIR}/include
+        ${_GSSAPI_INCLUDEDIR}
+)
+
+if (GSSAPI_FLAVOR_MIT)
+    find_library(GSSAPI_LIBRARY
+        NAMES
+            gssapi_krb5
+        PATHS
+            ${GSSAPI_ROOT_DIR}/lib
+            ${_GSSAPI_LIBDIR}
+    )
+
+    find_library(KRB5_LIBRARY
+        NAMES
+            krb5
+        PATHS
+            ${GSSAPI_ROOT_DIR}/lib
+            ${_GSSAPI_LIBDIR}
+    )
+
+    find_library(K5CRYPTO_LIBRARY
+        NAMES
+            k5crypto
+        PATHS
+            ${GSSAPI_ROOT_DIR}/lib
+            ${_GSSAPI_LIBDIR}
+    )
+
+    find_library(COM_ERR_LIBRARY
+        NAMES
+            com_err
+        PATHS
+            ${GSSAPI_ROOT_DIR}/lib
+            ${_GSSAPI_LIBDIR}
+    )
+
+    if (GSSAPI_LIBRARY)
+        set(GSSAPI_LIBRARIES
+            ${GSSAPI_LIBRARIES}
+            ${GSSAPI_LIBRARY}
+        )
+    endif (GSSAPI_LIBRARY)
+
+    if (KRB5_LIBRARY)
+        set(GSSAPI_LIBRARIES
+            ${GSSAPI_LIBRARIES}
+            ${KRB5_LIBRARY}
+        )
+    endif (KRB5_LIBRARY)
+
+    if (K5CRYPTO_LIBRARY)
+        set(GSSAPI_LIBRARIES
+            ${GSSAPI_LIBRARIES}
+            ${K5CRYPTO_LIBRARY}
+        )
+    endif (K5CRYPTO_LIBRARY)
+
+    if (COM_ERR_LIBRARY)
+        set(GSSAPI_LIBRARIES
+            ${GSSAPI_LIBRARIES}
+            ${COM_ERR_LIBRARY}
+        )
+    endif (COM_ERR_LIBRARY)
+endif (GSSAPI_FLAVOR_MIT)
+
+if (GSSAPI_FLAVOR_HEIMDAL)
+    find_library(GSSAPI_LIBRARY
+        NAMES
+            gssapi
+        PATHS
+            ${GSSAPI_ROOT_DIR}/lib
+            ${_GSSAPI_LIBDIR}
+    )
+
+    find_library(KRB5_LIBRARY
+        NAMES
+            krb5
+        PATHS
+            ${GSSAPI_ROOT_DIR}/lib
+            ${_GSSAPI_LIBDIR}
+    )
+
+    find_library(HCRYPTO_LIBRARY
+        NAMES
+            hcrypto
+        PATHS
+            ${GSSAPI_ROOT_DIR}/lib
+            ${_GSSAPI_LIBDIR}
+    )
+
+    find_library(COM_ERR_LIBRARY
+        NAMES
+            com_err
+        PATHS
+            ${GSSAPI_ROOT_DIR}/lib
+            ${_GSSAPI_LIBDIR}
+    )
+
+    find_library(HEIMNTLM_LIBRARY
+        NAMES
+            heimntlm
+        PATHS
+            ${GSSAPI_ROOT_DIR}/lib
+            ${_GSSAPI_LIBDIR}
+    )
+
+    find_library(HX509_LIBRARY
+        NAMES
+            hx509
+        PATHS
+            ${GSSAPI_ROOT_DIR}/lib
+            ${_GSSAPI_LIBDIR}
+    )
+
+    find_library(ASN1_LIBRARY
+        NAMES
+            asn1
+        PATHS
+            ${GSSAPI_ROOT_DIR}/lib
+            ${_GSSAPI_LIBDIR}
+    )
+
+    find_library(WIND_LIBRARY
+        NAMES
+            wind
+        PATHS
+            ${GSSAPI_ROOT_DIR}/lib
+            ${_GSSAPI_LIBDIR}
+    )
+
+    find_library(ROKEN_LIBRARY
+        NAMES
+            roken
+        PATHS
+            ${GSSAPI_ROOT_DIR}/lib
+            ${_GSSAPI_LIBDIR}
+    )
+
+    if (GSSAPI_LIBRARY)
+        set(GSSAPI_LIBRARIES
+            ${GSSAPI_LIBRARIES}
+            ${GSSAPI_LIBRARY}
+        )
+    endif (GSSAPI_LIBRARY)
+
+    if (KRB5_LIBRARY)
+        set(GSSAPI_LIBRARIES
+            ${GSSAPI_LIBRARIES}
+            ${KRB5_LIBRARY}
+        )
+    endif (KRB5_LIBRARY)
+
+    if (HCRYPTO_LIBRARY)
+        set(GSSAPI_LIBRARIES
+            ${GSSAPI_LIBRARIES}
+            ${HCRYPTO_LIBRARY}
+        )
+    endif (HCRYPTO_LIBRARY)
+
+    if (COM_ERR_LIBRARY)
+        set(GSSAPI_LIBRARIES
+            ${GSSAPI_LIBRARIES}
+            ${COM_ERR_LIBRARY}
+        )
+    endif (COM_ERR_LIBRARY)
+
+    if (HEIMNTLM_LIBRARY)
+        set(GSSAPI_LIBRARIES
+            ${GSSAPI_LIBRARIES}
+            ${HEIMNTLM_LIBRARY}
+        )
+    endif (HEIMNTLM_LIBRARY)
+
+    if (HX509_LIBRARY)
+        set(GSSAPI_LIBRARIES
+            ${GSSAPI_LIBRARIES}
+            ${HX509_LIBRARY}
+        )
+    endif (HX509_LIBRARY)
+
+    if (ASN1_LIBRARY)
+        set(GSSAPI_LIBRARIES
+            ${GSSAPI_LIBRARIES}
+            ${ASN1_LIBRARY}
+        )
+    endif (ASN1_LIBRARY)
+
+    if (WIND_LIBRARY)
+        set(GSSAPI_LIBRARIES
+            ${GSSAPI_LIBRARIES}
+            ${WIND_LIBRARY}
+        )
+    endif (WIND_LIBRARY)
+
+    if (ROKEN_LIBRARY)
+        set(GSSAPI_LIBRARIES
+            ${GSSAPI_LIBRARIES}
+            ${WIND_LIBRARY}
+        )
+    endif (ROKEN_LIBRARY)
+endif (GSSAPI_FLAVOR_HEIMDAL)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(GSSAPI DEFAULT_MSG GSSAPI_LIBRARIES GSSAPI_INCLUDE_DIR)
+
+if (GSSAPI_INCLUDE_DIRS AND GSSAPI_LIBRARIES)
+    set(GSSAPI_FOUND TRUE)
+endif (GSSAPI_INCLUDE_DIRS AND GSSAPI_LIBRARIES)
+
+# show the GSSAPI_INCLUDE_DIRS and GSSAPI_LIBRARIES variables only in the advanced view
+mark_as_advanced(GSSAPI_INCLUDE_DIRS GSSAPI_LIBRARIES)

vendor/libgit2-sys/libgit2/cmake/Modules/FindHTTP_Parser.cmake

diff --git a/vendor/libgit2-sys/libgit2/cmake/Modules/FindHTTP_Parser.cmake b/vendor/libgit2-sys/libgit2/cmake/Modules/FindHTTP_Parser.cmake
new file mode 100644
index 0000000..d92bf75
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/cmake/Modules/FindHTTP_Parser.cmake
@@ -0,0 +1,39 @@
+# - Try to find http-parser
+#
+# Defines the following variables:
+#
+# HTTP_PARSER_FOUND - system has http-parser
+# HTTP_PARSER_INCLUDE_DIR - the http-parser include directory
+# HTTP_PARSER_LIBRARIES - Link these to use http-parser
+# HTTP_PARSER_VERSION_MAJOR - major version
+# HTTP_PARSER_VERSION_MINOR - minor version
+# HTTP_PARSER_VERSION_STRING - the version of http-parser found
+
+# Find the header and library
+FIND_PATH(HTTP_PARSER_INCLUDE_DIR NAMES http_parser.h)
+FIND_LIBRARY(HTTP_PARSER_LIBRARY NAMES http_parser libhttp_parser)
+
+# Found the header, read version
+if (HTTP_PARSER_INCLUDE_DIR AND EXISTS "${HTTP_PARSER_INCLUDE_DIR}/http_parser.h")
+	FILE(READ "${HTTP_PARSER_INCLUDE_DIR}/http_parser.h" HTTP_PARSER_H)
+	IF (HTTP_PARSER_H)
+		STRING(REGEX REPLACE ".*#define[\t ]+HTTP_PARSER_VERSION_MAJOR[\t ]+([0-9]+).*" "\\1" HTTP_PARSER_VERSION_MAJOR "${HTTP_PARSER_H}")
+		STRING(REGEX REPLACE ".*#define[\t ]+HTTP_PARSER_VERSION_MINOR[\t ]+([0-9]+).*" "\\1" HTTP_PARSER_VERSION_MINOR "${HTTP_PARSER_H}")
+		SET(HTTP_PARSER_VERSION_STRING "${HTTP_PARSER_VERSION_MAJOR}.${HTTP_PARSER_VERSION_MINOR}")
+	ENDIF()
+	UNSET(HTTP_PARSER_H)
+ENDIF()
+
+# Handle the QUIETLY and REQUIRED arguments and set HTTP_PARSER_FOUND
+# to TRUE if all listed variables are TRUE
+INCLUDE(FindPackageHandleStandardArgs)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(HTTP_Parser REQUIRED_VARS HTTP_PARSER_INCLUDE_DIR HTTP_PARSER_LIBRARY)
+
+# Hide advanced variables
+MARK_AS_ADVANCED(HTTP_PARSER_INCLUDE_DIR HTTP_PARSER_LIBRARY)
+
+# Set standard variables
+IF (HTTP_PARSER_FOUND)
+	SET(HTTP_PARSER_LIBRARIES ${HTTP_PARSER_LIBRARY})
+	set(HTTP_PARSER_INCLUDE_DIRS ${HTTP_PARSER_INCLUDE_DIR})
+ENDIF()

vendor/libgit2-sys/libgit2/cmake/Modules/FindIconv.cmake

diff --git a/vendor/libgit2-sys/libgit2/cmake/Modules/FindIconv.cmake b/vendor/libgit2-sys/libgit2/cmake/Modules/FindIconv.cmake
new file mode 100644
index 0000000..95414bd
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/cmake/Modules/FindIconv.cmake
@@ -0,0 +1,40 @@
+# - Try to find Iconv
+# Once done this will define
+#
+# ICONV_FOUND - system has Iconv
+# ICONV_INCLUDE_DIR - the Iconv include directory
+# ICONV_LIBRARIES - Link these to use Iconv
+#
+
+IF(ICONV_INCLUDE_DIR AND ICONV_LIBRARIES)
+	# Already in cache, be silent
+	SET(ICONV_FIND_QUIETLY TRUE)
+ENDIF()
+
+FIND_PATH(ICONV_INCLUDE_DIR iconv.h)
+FIND_LIBRARY(iconv_lib NAMES iconv libiconv libiconv-2 c)
+
+IF(ICONV_INCLUDE_DIR AND iconv_lib)
+	 SET(ICONV_FOUND TRUE)
+ENDIF()
+
+IF(ICONV_FOUND)
+	# split iconv into -L and -l linker options, so we can set them for pkg-config
+	GET_FILENAME_COMPONENT(iconv_path ${iconv_lib} PATH)
+	GET_FILENAME_COMPONENT(iconv_name ${iconv_lib} NAME_WE)
+	STRING(REGEX REPLACE "^lib" "" iconv_name ${iconv_name})
+	SET(ICONV_LIBRARIES "-L${iconv_path} -l${iconv_name}")
+
+	IF(NOT ICONV_FIND_QUIETLY)
+		MESSAGE(STATUS "Found Iconv: ${ICONV_LIBRARIES}")
+	ENDIF(NOT ICONV_FIND_QUIETLY)
+ELSE()
+	IF(Iconv_FIND_REQUIRED)
+		MESSAGE(FATAL_ERROR "Could not find Iconv")
+	ENDIF(Iconv_FIND_REQUIRED)
+ENDIF()
+
+MARK_AS_ADVANCED(
+	ICONV_INCLUDE_DIR
+	ICONV_LIBRARIES
+)

vendor/libgit2-sys/libgit2/cmake/Modules/FindPkgLibraries.cmake

diff --git a/vendor/libgit2-sys/libgit2/cmake/Modules/FindPkgLibraries.cmake b/vendor/libgit2-sys/libgit2/cmake/Modules/FindPkgLibraries.cmake
new file mode 100644
index 0000000..49311c3
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/cmake/Modules/FindPkgLibraries.cmake
@@ -0,0 +1,28 @@
+INCLUDE(FindPkgConfig)
+
+# This function will find and set up a pkg-config based module.
+# If a pc-file was found, it will resolve library paths to
+# absolute paths. Furthermore, the function will automatically
+# fall back to use static libraries in case no dynamic libraries
+# were found.
+FUNCTION(FIND_PKGLIBRARIES prefix package)
+	PKG_CHECK_MODULES(${prefix} ${package})
+	IF(NOT ${prefix}_FOUND)
+		RETURN()
+	ENDIF()
+
+	FOREACH(LIBRARY ${${prefix}_LIBRARIES})
+		FIND_LIBRARY(${LIBRARY}_RESOLVED ${LIBRARY} PATHS ${${prefix}_LIBRARY_DIRS})
+		IF(${${LIBRARY}_RESOLVED} STREQUAL "${LIBRARY}_RESOLVED-NOTFOUND")
+			MESSAGE(FATAL_ERROR "could not resolve ${LIBRARY}")
+		ENDIF()
+		LIST(APPEND RESOLVED_LIBRARIES ${${LIBRARY}_RESOLVED})
+	ENDFOREACH(LIBRARY)
+
+	SET(${prefix}_FOUND 1 PARENT_SCOPE)
+	SET(${prefix}_LIBRARIES ${RESOLVED_LIBRARIES} PARENT_SCOPE)
+	SET(${prefix}_INCLUDE_DIRS ${${prefix}_INCLUDE_DIRS} PARENT_SCOPE)
+	SET(${prefix}_LDFLAGS ${${prefix}_LDFLAGS} PARENT_SCOPE)
+
+	MESSAGE(STATUS "  Resolved libraries: ${RESOLVED_LIBRARIES}")
+ENDFUNCTION()

vendor/libgit2-sys/libgit2/cmake/Modules/FindSecurity.cmake

diff --git a/vendor/libgit2-sys/libgit2/cmake/Modules/FindSecurity.cmake b/vendor/libgit2-sys/libgit2/cmake/Modules/FindSecurity.cmake
new file mode 100644
index 0000000..487f7e5
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/cmake/Modules/FindSecurity.cmake
@@ -0,0 +1,28 @@
+# Find Security.framework
+# This will define :
+#
+# SECURITY_FOUND
+# SECURITY_LIBRARIES
+# SECURITY_LDFLAGS
+# SECURITY_HAS_SSLCREATECONTEXT
+#
+
+FIND_PATH(SECURITY_INCLUDE_DIR NAMES Security/Security.h)
+FIND_LIBRARY(SECURITY_LIBRARIES NAMES Security)
+IF (SECURITY_INCLUDE_DIR AND SECURITY_LIBRARIES)
+	IF (NOT Security_FIND_QUIETLY)
+		MESSAGE("-- Found Security ${SECURITY_LIBRARIES}")
+	ENDIF()
+	SET(SECURITY_FOUND TRUE)
+	SET(SECURITY_LDFLAGS "-framework Security")
+	CHECK_LIBRARY_EXISTS("${SECURITY_LIBRARIES}" SSLCreateContext "Security/SecureTransport.h" SECURITY_HAS_SSLCREATECONTEXT)
+ENDIF ()
+
+IF (Security_FIND_REQUIRED AND NOT SECURITY_FOUND)
+	MESSAGE(FATAL "-- Security not found")
+ENDIF()
+
+MARK_AS_ADVANCED(
+	SECURITY_INCLUDE_DIR
+	SECURITY_LIBRARIES
+)

vendor/libgit2-sys/libgit2/cmake/Modules/FindStatNsec.cmake

diff --git a/vendor/libgit2-sys/libgit2/cmake/Modules/FindStatNsec.cmake b/vendor/libgit2-sys/libgit2/cmake/Modules/FindStatNsec.cmake
new file mode 100644
index 0000000..fa550a2
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/cmake/Modules/FindStatNsec.cmake
@@ -0,0 +1,20 @@
+CHECK_STRUCT_HAS_MEMBER ("struct stat" st_mtim "sys/types.h;sys/stat.h"
+	HAVE_STRUCT_STAT_ST_MTIM LANGUAGE C)
+CHECK_STRUCT_HAS_MEMBER ("struct stat" st_mtimespec "sys/types.h;sys/stat.h"
+	HAVE_STRUCT_STAT_ST_MTIMESPEC LANGUAGE C)
+CHECK_STRUCT_HAS_MEMBER("struct stat" st_mtime_nsec sys/stat.h
+	HAVE_STRUCT_STAT_MTIME_NSEC LANGUAGE C)
+
+IF (HAVE_STRUCT_STAT_ST_MTIM)
+	CHECK_STRUCT_HAS_MEMBER("struct stat" st_mtim.tv_nsec sys/stat.h
+		HAVE_STRUCT_STAT_NSEC LANGUAGE C)
+ELSEIF (HAVE_STRUCT_STAT_ST_MTIMESPEC)
+	CHECK_STRUCT_HAS_MEMBER("struct stat" st_mtimespec.tv_nsec sys/stat.h
+		HAVE_STRUCT_STAT_NSEC LANGUAGE C)
+ELSE ()
+	SET( HAVE_STRUCT_STAT_NSEC ON )
+ENDIF()
+
+IF (HAVE_STRUCT_STAT_NSEC OR WIN32)
+	OPTION( USE_NSEC		"Care about sub-second file mtimes and ctimes"	ON  )
+ENDIF()

vendor/libgit2-sys/libgit2/cmake/Modules/FindmbedTLS.cmake

diff --git a/vendor/libgit2-sys/libgit2/cmake/Modules/FindmbedTLS.cmake b/vendor/libgit2-sys/libgit2/cmake/Modules/FindmbedTLS.cmake
new file mode 100644
index 0000000..9329755
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/cmake/Modules/FindmbedTLS.cmake
@@ -0,0 +1,93 @@
+# - Try to find mbedTLS
+# Once done this will define
+#
+# Read-Only variables
+#  MBEDTLS_FOUND - system has mbedTLS
+#  MBEDTLS_INCLUDE_DIR - the mbedTLS include directory
+#  MBEDTLS_LIBRARY_DIR - the mbedTLS library directory
+#  MBEDTLS_LIBRARIES - Link these to use mbedTLS
+#  MBEDTLS_LIBRARY - path to mbedTLS library
+#  MBEDX509_LIBRARY - path to mbedTLS X.509 library
+#  MBEDCRYPTO_LIBRARY - path to mbedTLS Crypto library
+#
+# Hint
+#  MBEDTLS_ROOT_DIR can be pointed to a local mbedTLS installation.
+
+SET(_MBEDTLS_ROOT_HINTS
+    ${MBEDTLS_ROOT_DIR}
+    ENV MBEDTLS_ROOT_DIR
+)
+
+SET(_MBEDTLS_ROOT_HINTS_AND_PATHS
+    HINTS ${_MBEDTLS_ROOT_HINTS}
+    PATHS ${_MBEDTLS_ROOT_PATHS}
+)
+
+FIND_PATH(MBEDTLS_INCLUDE_DIR
+    NAMES mbedtls/version.h
+    ${_MBEDTLS_ROOT_HINTS_AND_PATHS}
+    PATH_SUFFIXES include
+)
+
+IF(MBEDTLS_INCLUDE_DIR AND MBEDTLS_LIBRARIES)
+    # Already in cache, be silent
+    SET(MBEDTLS_FIND_QUIETLY TRUE)
+ENDIF()
+
+FIND_LIBRARY(MBEDTLS_LIBRARY
+    NAMES mbedtls libmbedtls
+    ${_MBEDTLS_ROOT_HINTS_AND_PATHS}
+    PATH_SUFFIXES library
+)
+FIND_LIBRARY(MBEDX509_LIBRARY
+    NAMES mbedx509 libmbedx509
+    ${_MBEDTLS_ROOT_HINTS_AND_PATHS}
+    PATH_SUFFIXES library
+)
+FIND_LIBRARY(MBEDCRYPTO_LIBRARY
+    NAMES mbedcrypto libmbedcrypto
+    ${_MBEDTLS_ROOT_HINTS_AND_PATHS}
+    PATH_SUFFIXES library
+)
+
+IF(MBEDTLS_INCLUDE_DIR AND MBEDTLS_LIBRARY AND MBEDX509_LIBRARY AND MBEDCRYPTO_LIBRARY)
+     SET(MBEDTLS_FOUND TRUE)
+ENDIF()
+
+IF(MBEDTLS_FOUND)
+    # split mbedTLS into -L and -l linker options, so we can set them for pkg-config
+    GET_FILENAME_COMPONENT(MBEDTLS_LIBRARY_DIR ${MBEDTLS_LIBRARY} PATH)
+    GET_FILENAME_COMPONENT(MBEDTLS_LIBRARY_FILE ${MBEDTLS_LIBRARY} NAME_WE)
+    GET_FILENAME_COMPONENT(MBEDX509_LIBRARY_FILE ${MBEDX509_LIBRARY} NAME_WE)
+    GET_FILENAME_COMPONENT(MBEDCRYPTO_LIBRARY_FILE ${MBEDCRYPTO_LIBRARY} NAME_WE)
+    STRING(REGEX REPLACE "^lib" "" MBEDTLS_LIBRARY_FILE ${MBEDTLS_LIBRARY_FILE})
+    STRING(REGEX REPLACE "^lib" "" MBEDX509_LIBRARY_FILE ${MBEDX509_LIBRARY_FILE})
+    STRING(REGEX REPLACE "^lib" "" MBEDCRYPTO_LIBRARY_FILE ${MBEDCRYPTO_LIBRARY_FILE})
+    SET(MBEDTLS_LIBRARIES "-L${MBEDTLS_LIBRARY_DIR} -l${MBEDTLS_LIBRARY_FILE} -l${MBEDX509_LIBRARY_FILE} -l${MBEDCRYPTO_LIBRARY_FILE}")
+
+    IF(NOT MBEDTLS_FIND_QUIETLY)
+        MESSAGE(STATUS "Found mbedTLS:")
+        FILE(READ ${MBEDTLS_INCLUDE_DIR}/mbedtls/version.h MBEDTLSCONTENT)
+        STRING(REGEX MATCH "MBEDTLS_VERSION_STRING +\"[0-9|.]+\"" MBEDTLSMATCH ${MBEDTLSCONTENT})
+        IF (MBEDTLSMATCH)
+            STRING(REGEX REPLACE "MBEDTLS_VERSION_STRING +\"([0-9|.]+)\"" "\\1" MBEDTLS_VERSION ${MBEDTLSMATCH})
+            MESSAGE(STATUS "  version ${MBEDTLS_VERSION}")
+        ENDIF(MBEDTLSMATCH)
+        MESSAGE(STATUS "  TLS: ${MBEDTLS_LIBRARY}")
+        MESSAGE(STATUS "  X509: ${MBEDX509_LIBRARY}")
+        MESSAGE(STATUS "  Crypto: ${MBEDCRYPTO_LIBRARY}")
+    ENDIF(NOT MBEDTLS_FIND_QUIETLY)
+ELSE(MBEDTLS_FOUND)
+    IF(MBEDTLS_FIND_REQUIRED)
+        MESSAGE(FATAL_ERROR "Could not find mbedTLS")
+    ENDIF(MBEDTLS_FIND_REQUIRED)
+ENDIF(MBEDTLS_FOUND)
+
+MARK_AS_ADVANCED(
+    MBEDTLS_INCLUDE_DIR
+    MBEDTLS_LIBRARY_DIR
+    MBEDTLS_LIBRARIES
+    MBEDTLS_LIBRARY
+    MBEDX509_LIBRARY
+    MBEDCRYPTO_LIBRARY
+)

vendor/libgit2-sys/libgit2/cmake/Modules/IdeSplitSources.cmake

diff --git a/vendor/libgit2-sys/libgit2/cmake/Modules/IdeSplitSources.cmake b/vendor/libgit2-sys/libgit2/cmake/Modules/IdeSplitSources.cmake
new file mode 100644
index 0000000..e2e09b4
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/cmake/Modules/IdeSplitSources.cmake
@@ -0,0 +1,22 @@
+# This function splits the sources files up into their appropriate
+# subdirectories.  This is especially useful for IDEs like Xcode and
+# Visual Studio, so that you can navigate into the libgit2_clar project,
+# and see the folders within the tests folder (instead of just seeing all
+# source and tests in a single folder.)
+FUNCTION(IDE_SPLIT_SOURCES target)
+	IF(MSVC_IDE OR CMAKE_GENERATOR STREQUAL Xcode)
+		GET_TARGET_PROPERTY(sources ${target} SOURCES)
+		FOREACH(source ${sources})
+			IF(source MATCHES ".*/")
+				STRING(REPLACE ${libgit2_SOURCE_DIR}/ "" rel ${source})
+				IF(rel)
+					STRING(REGEX REPLACE "/([^/]*)$" "" rel ${rel})
+					IF(rel)
+						STRING(REPLACE "/" "\\\\" rel ${rel})
+						SOURCE_GROUP(${rel} FILES ${source})
+					ENDIF()
+				ENDIF()
+			ENDIF()
+		ENDFOREACH()
+	ENDIF()
+ENDFUNCTION()

vendor/libgit2-sys/libgit2/deps/http-parser/CMakeLists.txt

diff --git a/vendor/libgit2-sys/libgit2/deps/http-parser/CMakeLists.txt b/vendor/libgit2-sys/libgit2/deps/http-parser/CMakeLists.txt
new file mode 100644
index 0000000..77d9de7
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/http-parser/CMakeLists.txt
@@ -0,0 +1,3 @@
+FILE(GLOB SRC_HTTP "*.c" "*.h")
+
+ADD_LIBRARY(http-parser OBJECT ${SRC_HTTP})

vendor/libgit2-sys/libgit2/deps/http-parser/LICENSE-MIT

diff --git a/vendor/libgit2-sys/libgit2/deps/http-parser/LICENSE-MIT b/vendor/libgit2-sys/libgit2/deps/http-parser/LICENSE-MIT
new file mode 100644
index 0000000..58010b3
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/http-parser/LICENSE-MIT
@@ -0,0 +1,23 @@
+http_parser.c is based on src/http/ngx_http_parse.c from NGINX copyright
+Igor Sysoev.
+
+Additional changes are licensed under the same terms as NGINX and
+copyright Joyent, Inc. and other Node contributors. All rights reserved.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to
+deal in the Software without restriction, including without limitation the
+rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+IN THE SOFTWARE. 

vendor/libgit2-sys/libgit2/deps/http-parser/http_parser.c

diff --git a/vendor/libgit2-sys/libgit2/deps/http-parser/http_parser.c b/vendor/libgit2-sys/libgit2/deps/http-parser/http_parser.c
new file mode 100644
index 0000000..27bdd20
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/http-parser/http_parser.c
@@ -0,0 +1,2177 @@
+/* Based on src/http/ngx_http_parse.c from NGINX copyright Igor Sysoev
+ *
+ * Additional changes are licensed under the same terms as NGINX and
+ * copyright Joyent, Inc. and other Node contributors. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+#include "http_parser.h"
+#include <assert.h>
+#include <stddef.h>
+#include <ctype.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+
+#ifndef ULLONG_MAX
+# define ULLONG_MAX ((uint64_t) -1) /* 2^64-1 */
+#endif
+
+#ifndef MIN
+# define MIN(a,b) ((a) < (b) ? (a) : (b))
+#endif
+
+#ifndef ARRAY_SIZE
+# define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
+#endif
+
+#ifndef BIT_AT
+# define BIT_AT(a, i)                                                \
+  (!!((unsigned int) (a)[(unsigned int) (i) >> 3] &                  \
+   (1 << ((unsigned int) (i) & 7))))
+#endif
+
+#ifndef ELEM_AT
+# define ELEM_AT(a, i, v) ((unsigned int) (i) < ARRAY_SIZE(a) ? (a)[(i)] : (v))
+#endif
+
+#define SET_ERRNO(e)                                                 \
+do {                                                                 \
+  parser->http_errno = (e);                                          \
+} while(0)
+
+
+/* Run the notify callback FOR, returning ER if it fails */
+#define CALLBACK_NOTIFY_(FOR, ER)                                    \
+do {                                                                 \
+  assert(HTTP_PARSER_ERRNO(parser) == HPE_OK);                       \
+                                                                     \
+  if (settings->on_##FOR) {                                          \
+    if (0 != settings->on_##FOR(parser)) {                           \
+      SET_ERRNO(HPE_CB_##FOR);                                       \
+    }                                                                \
+                                                                     \
+    /* We either errored above or got paused; get out */             \
+    if (HTTP_PARSER_ERRNO(parser) != HPE_OK) {                       \
+      return (ER);                                                   \
+    }                                                                \
+  }                                                                  \
+} while (0)
+
+/* Run the notify callback FOR and consume the current byte */
+#define CALLBACK_NOTIFY(FOR)            CALLBACK_NOTIFY_(FOR, p - data + 1)
+
+/* Run the notify callback FOR and don't consume the current byte */
+#define CALLBACK_NOTIFY_NOADVANCE(FOR)  CALLBACK_NOTIFY_(FOR, p - data)
+
+/* Run data callback FOR with LEN bytes, returning ER if it fails */
+#define CALLBACK_DATA_(FOR, LEN, ER)                                 \
+do {                                                                 \
+  assert(HTTP_PARSER_ERRNO(parser) == HPE_OK);                       \
+                                                                     \
+  if (FOR##_mark) {                                                  \
+    if (settings->on_##FOR) {                                        \
+      if (0 != settings->on_##FOR(parser, FOR##_mark, (LEN))) {      \
+        SET_ERRNO(HPE_CB_##FOR);                                     \
+      }                                                              \
+                                                                     \
+      /* We either errored above or got paused; get out */           \
+      if (HTTP_PARSER_ERRNO(parser) != HPE_OK) {                     \
+        return (ER);                                                 \
+      }                                                              \
+    }                                                                \
+    FOR##_mark = NULL;                                               \
+  }                                                                  \
+} while (0)
+
+/* Run the data callback FOR and consume the current byte */
+#define CALLBACK_DATA(FOR)                                           \
+    CALLBACK_DATA_(FOR, p - FOR##_mark, p - data + 1)
+
+/* Run the data callback FOR and don't consume the current byte */
+#define CALLBACK_DATA_NOADVANCE(FOR)                                 \
+    CALLBACK_DATA_(FOR, p - FOR##_mark, p - data)
+
+/* Set the mark FOR; non-destructive if mark is already set */
+#define MARK(FOR)                                                    \
+do {                                                                 \
+  if (!FOR##_mark) {                                                 \
+    FOR##_mark = p;                                                  \
+  }                                                                  \
+} while (0)
+
+
+#define PROXY_CONNECTION "proxy-connection"
+#define CONNECTION "connection"
+#define CONTENT_LENGTH "content-length"
+#define TRANSFER_ENCODING "transfer-encoding"
+#define UPGRADE "upgrade"
+#define CHUNKED "chunked"
+#define KEEP_ALIVE "keep-alive"
+#define CLOSE "close"
+
+
+static const char *method_strings[] =
+  {
+#define XX(num, name, string) #string,
+  HTTP_METHOD_MAP(XX)
+#undef XX
+  };
+
+
+/* Tokens as defined by rfc 2616. Also lowercases them.
+ *        token       = 1*<any CHAR except CTLs or separators>
+ *     separators     = "(" | ")" | "<" | ">" | "@"
+ *                    | "," | ";" | ":" | "\" | <">
+ *                    | "/" | "[" | "]" | "?" | "="
+ *                    | "{" | "}" | SP | HT
+ */
+static const char tokens[256] = {
+/*   0 nul    1 soh    2 stx    3 etx    4 eot    5 enq    6 ack    7 bel  */
+        0,       0,       0,       0,       0,       0,       0,       0,
+/*   8 bs     9 ht    10 nl    11 vt    12 np    13 cr    14 so    15 si   */
+        0,       0,       0,       0,       0,       0,       0,       0,
+/*  16 dle   17 dc1   18 dc2   19 dc3   20 dc4   21 nak   22 syn   23 etb */
+        0,       0,       0,       0,       0,       0,       0,       0,
+/*  24 can   25 em    26 sub   27 esc   28 fs    29 gs    30 rs    31 us  */
+        0,       0,       0,       0,       0,       0,       0,       0,
+/*  32 sp    33  !    34  "    35  #    36  $    37  %    38  &    39  '  */
+        0,      '!',      0,      '#',     '$',     '%',     '&',    '\'',
+/*  40  (    41  )    42  *    43  +    44  ,    45  -    46  .    47  /  */
+        0,       0,      '*',     '+',      0,      '-',     '.',      0,
+/*  48  0    49  1    50  2    51  3    52  4    53  5    54  6    55  7  */
+       '0',     '1',     '2',     '3',     '4',     '5',     '6',     '7',
+/*  56  8    57  9    58  :    59  ;    60  <    61  =    62  >    63  ?  */
+       '8',     '9',      0,       0,       0,       0,       0,       0,
+/*  64  @    65  A    66  B    67  C    68  D    69  E    70  F    71  G  */
+        0,      'a',     'b',     'c',     'd',     'e',     'f',     'g',
+/*  72  H    73  I    74  J    75  K    76  L    77  M    78  N    79  O  */
+       'h',     'i',     'j',     'k',     'l',     'm',     'n',     'o',
+/*  80  P    81  Q    82  R    83  S    84  T    85  U    86  V    87  W  */
+       'p',     'q',     'r',     's',     't',     'u',     'v',     'w',
+/*  88  X    89  Y    90  Z    91  [    92  \    93  ]    94  ^    95  _  */
+       'x',     'y',     'z',      0,       0,       0,      '^',     '_',
+/*  96  `    97  a    98  b    99  c   100  d   101  e   102  f   103  g  */
+       '`',     'a',     'b',     'c',     'd',     'e',     'f',     'g',
+/* 104  h   105  i   106  j   107  k   108  l   109  m   110  n   111  o  */
+       'h',     'i',     'j',     'k',     'l',     'm',     'n',     'o',
+/* 112  p   113  q   114  r   115  s   116  t   117  u   118  v   119  w  */
+       'p',     'q',     'r',     's',     't',     'u',     'v',     'w',
+/* 120  x   121  y   122  z   123  {   124  |   125  }   126  ~   127 del */
+       'x',     'y',     'z',      0,      '|',      0,      '~',       0 };
+
+
+static const int8_t unhex[256] =
+  {-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
+  ,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
+  ,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
+  , 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,-1,-1,-1,-1,-1,-1
+  ,-1,10,11,12,13,14,15,-1,-1,-1,-1,-1,-1,-1,-1,-1
+  ,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
+  ,-1,10,11,12,13,14,15,-1,-1,-1,-1,-1,-1,-1,-1,-1
+  ,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
+  };
+
+
+#if HTTP_PARSER_STRICT
+# define T(v) 0
+#else
+# define T(v) v
+#endif
+
+
+static const uint8_t normal_url_char[32] = {
+/*   0 nul    1 soh    2 stx    3 etx    4 eot    5 enq    6 ack    7 bel  */
+        0    |   0    |   0    |   0    |   0    |   0    |   0    |   0,
+/*   8 bs     9 ht    10 nl    11 vt    12 np    13 cr    14 so    15 si   */
+        0    | T(2)   |   0    |   0    | T(16)  |   0    |   0    |   0,
+/*  16 dle   17 dc1   18 dc2   19 dc3   20 dc4   21 nak   22 syn   23 etb */
+        0    |   0    |   0    |   0    |   0    |   0    |   0    |   0,
+/*  24 can   25 em    26 sub   27 esc   28 fs    29 gs    30 rs    31 us  */
+        0    |   0    |   0    |   0    |   0    |   0    |   0    |   0,
+/*  32 sp    33  !    34  "    35  #    36  $    37  %    38  &    39  '  */
+        0    |   2    |   4    |   0    |   16   |   32   |   64   |  128,
+/*  40  (    41  )    42  *    43  +    44  ,    45  -    46  .    47  /  */
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |  128,
+/*  48  0    49  1    50  2    51  3    52  4    53  5    54  6    55  7  */
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |  128,
+/*  56  8    57  9    58  :    59  ;    60  <    61  =    62  >    63  ?  */
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |   0,
+/*  64  @    65  A    66  B    67  C    68  D    69  E    70  F    71  G  */
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |  128,
+/*  72  H    73  I    74  J    75  K    76  L    77  M    78  N    79  O  */
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |  128,
+/*  80  P    81  Q    82  R    83  S    84  T    85  U    86  V    87  W  */
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |  128,
+/*  88  X    89  Y    90  Z    91  [    92  \    93  ]    94  ^    95  _  */
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |  128,
+/*  96  `    97  a    98  b    99  c   100  d   101  e   102  f   103  g  */
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |  128,
+/* 104  h   105  i   106  j   107  k   108  l   109  m   110  n   111  o  */
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |  128,
+/* 112  p   113  q   114  r   115  s   116  t   117  u   118  v   119  w  */
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |  128,
+/* 120  x   121  y   122  z   123  {   124  |   125  }   126  ~   127 del */
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |   0, };
+
+#undef T
+
+enum state
+  { s_dead = 1 /* important that this is > 0 */
+
+  , s_start_req_or_res
+  , s_res_or_resp_H
+  , s_start_res
+  , s_res_H
+  , s_res_HT
+  , s_res_HTT
+  , s_res_HTTP
+  , s_res_first_http_major
+  , s_res_http_major
+  , s_res_first_http_minor
+  , s_res_http_minor
+  , s_res_first_status_code
+  , s_res_status_code
+  , s_res_status
+  , s_res_line_almost_done
+
+  , s_start_req
+
+  , s_req_method
+  , s_req_spaces_before_url
+  , s_req_schema
+  , s_req_schema_slash
+  , s_req_schema_slash_slash
+  , s_req_server_start
+  , s_req_server
+  , s_req_server_with_at
+  , s_req_path
+  , s_req_query_string_start
+  , s_req_query_string
+  , s_req_fragment_start
+  , s_req_fragment
+  , s_req_http_start
+  , s_req_http_H
+  , s_req_http_HT
+  , s_req_http_HTT
+  , s_req_http_HTTP
+  , s_req_first_http_major
+  , s_req_http_major
+  , s_req_first_http_minor
+  , s_req_http_minor
+  , s_req_line_almost_done
+
+  , s_header_field_start
+  , s_header_field
+  , s_header_value_start
+  , s_header_value
+  , s_header_value_lws
+
+  , s_header_almost_done
+
+  , s_chunk_size_start
+  , s_chunk_size
+  , s_chunk_parameters
+  , s_chunk_size_almost_done
+
+  , s_headers_almost_done
+  , s_headers_done
+
+  /* Important: 's_headers_done' must be the last 'header' state. All
+   * states beyond this must be 'body' states. It is used for overflow
+   * checking. See the PARSING_HEADER() macro.
+   */
+
+  , s_chunk_data
+  , s_chunk_data_almost_done
+  , s_chunk_data_done
+
+  , s_body_identity
+  , s_body_identity_eof
+
+  , s_message_done
+  };
+
+
+#define PARSING_HEADER(state) (state <= s_headers_done)
+
+
+enum header_states
+  { h_general = 0
+  , h_C
+  , h_CO
+  , h_CON
+
+  , h_matching_connection
+  , h_matching_proxy_connection
+  , h_matching_content_length
+  , h_matching_transfer_encoding
+  , h_matching_upgrade
+
+  , h_connection
+  , h_content_length
+  , h_transfer_encoding
+  , h_upgrade
+
+  , h_matching_transfer_encoding_chunked
+  , h_matching_connection_keep_alive
+  , h_matching_connection_close
+
+  , h_transfer_encoding_chunked
+  , h_connection_keep_alive
+  , h_connection_close
+  };
+
+enum http_host_state
+  {
+    s_http_host_dead = 1
+  , s_http_userinfo_start
+  , s_http_userinfo
+  , s_http_host_start
+  , s_http_host_v6_start
+  , s_http_host
+  , s_http_host_v6
+  , s_http_host_v6_end
+  , s_http_host_port_start
+  , s_http_host_port
+};
+
+/* Macros for character classes; depends on strict-mode  */
+#define CR                  '\r'
+#define LF                  '\n'
+#define LOWER(c)            (unsigned char)(c | 0x20)
+#define IS_ALPHA(c)         (LOWER(c) >= 'a' && LOWER(c) <= 'z')
+#define IS_NUM(c)           ((c) >= '0' && (c) <= '9')
+#define IS_ALPHANUM(c)      (IS_ALPHA(c) || IS_NUM(c))
+#define IS_HEX(c)           (IS_NUM(c) || (LOWER(c) >= 'a' && LOWER(c) <= 'f'))
+#define IS_MARK(c)          ((c) == '-' || (c) == '_' || (c) == '.' || \
+  (c) == '!' || (c) == '~' || (c) == '*' || (c) == '\'' || (c) == '(' || \
+  (c) == ')')
+#define IS_USERINFO_CHAR(c) (IS_ALPHANUM(c) || IS_MARK(c) || (c) == '%' || \
+  (c) == ';' || (c) == ':' || (c) == '&' || (c) == '=' || (c) == '+' || \
+  (c) == '$' || (c) == ',')
+
+#if HTTP_PARSER_STRICT
+#define TOKEN(c)            (tokens[(unsigned char)c])
+#define IS_URL_CHAR(c)      (BIT_AT(normal_url_char, (unsigned char)c))
+#define IS_HOST_CHAR(c)     (IS_ALPHANUM(c) || (c) == '.' || (c) == '-')
+#else
+#define TOKEN(c)            ((c == ' ') ? ' ' : tokens[(unsigned char)c])
+#define IS_URL_CHAR(c)                                                         \
+  (BIT_AT(normal_url_char, (unsigned char)c) || ((c) & 0x80))
+#define IS_HOST_CHAR(c)                                                        \
+  (IS_ALPHANUM(c) || (c) == '.' || (c) == '-' || (c) == '_')
+#endif
+
+
+#define start_state (parser->type == HTTP_REQUEST ? s_start_req : s_start_res)
+
+
+#if HTTP_PARSER_STRICT
+# define STRICT_CHECK(cond)                                          \
+do {                                                                 \
+  if (cond) {                                                        \
+    SET_ERRNO(HPE_STRICT);                                           \
+    goto error;                                                      \
+  }                                                                  \
+} while (0)
+# define NEW_MESSAGE() (http_should_keep_alive(parser) ? start_state : s_dead)
+#else
+# define STRICT_CHECK(cond)
+# define NEW_MESSAGE() start_state
+#endif
+
+
+/* Map errno values to strings for human-readable output */
+#define HTTP_STRERROR_GEN(n, s) { "HPE_" #n, s },
+static struct {
+  const char *name;
+  const char *description;
+} http_strerror_tab[] = {
+  HTTP_ERRNO_MAP(HTTP_STRERROR_GEN)
+};
+#undef HTTP_STRERROR_GEN
+
+int http_message_needs_eof(const http_parser *parser);
+
+/* Our URL parser.
+ *
+ * This is designed to be shared by http_parser_execute() for URL validation,
+ * hence it has a state transition + byte-for-byte interface. In addition, it
+ * is meant to be embedded in http_parser_parse_url(), which does the dirty
+ * work of turning state transitions URL components for its API.
+ *
+ * This function should only be invoked with non-space characters. It is
+ * assumed that the caller cares about (and can detect) the transition between
+ * URL and non-URL states by looking for these.
+ */
+static enum state
+parse_url_char(enum state s, const char ch)
+{
+  if (ch == ' ' || ch == '\r' || ch == '\n') {
+    return s_dead;
+  }
+
+#if HTTP_PARSER_STRICT
+  if (ch == '\t' || ch == '\f') {
+    return s_dead;
+  }
+#endif
+
+  switch (s) {
+    case s_req_spaces_before_url:
+      /* Proxied requests are followed by scheme of an absolute URI (alpha).
+       * All methods except CONNECT are followed by '/' or '*'.
+       */
+
+      if (ch == '/' || ch == '*') {
+        return s_req_path;
+      }
+
+      /* The schema must start with an alpha character. After that, it may
+       * consist of digits, '+', '-' or '.', followed by a ':'.
+       */
+      if (IS_ALPHA(ch)) {
+        return s_req_schema;
+      }
+
+      break;
+
+    case s_req_schema:
+      if (IS_ALPHANUM(ch) || ch == '+' || ch == '-' || ch == '.') {
+        return s;
+      }
+
+      if (ch == ':') {
+        return s_req_schema_slash;
+      }
+
+      break;
+
+    case s_req_schema_slash:
+      if (ch == '/') {
+        return s_req_schema_slash_slash;
+      }
+
+      break;
+
+    case s_req_schema_slash_slash:
+      if (ch == '/') {
+        return s_req_server_start;
+      }
+
+      break;
+
+    case s_req_server_with_at:
+      if (ch == '@') {
+        return s_dead;
+      }
+
+    /* FALLTHROUGH */
+    case s_req_server_start:
+    case s_req_server:
+      if (ch == '/') {
+        return s_req_path;
+      }
+
+      if (ch == '?') {
+        return s_req_query_string_start;
+      }
+
+      if (ch == '@') {
+        return s_req_server_with_at;
+      }
+
+      if (IS_USERINFO_CHAR(ch) || ch == '[' || ch == ']') {
+        return s_req_server;
+      }
+
+      break;
+
+    case s_req_path:
+      if (IS_URL_CHAR(ch)) {
+        return s;
+      }
+
+      switch (ch) {
+        case '?':
+          return s_req_query_string_start;
+
+        case '#':
+          return s_req_fragment_start;
+      }
+
+      break;
+
+    case s_req_query_string_start:
+    case s_req_query_string:
+      if (IS_URL_CHAR(ch)) {
+        return s_req_query_string;
+      }
+
+      switch (ch) {
+        case '?':
+          /* allow extra '?' in query string */
+          return s_req_query_string;
+
+        case '#':
+          return s_req_fragment_start;
+      }
+
+      break;
+
+    case s_req_fragment_start:
+      if (IS_URL_CHAR(ch)) {
+        return s_req_fragment;
+      }
+
+      switch (ch) {
+        case '?':
+          return s_req_fragment;
+
+        case '#':
+          return s;
+      }
+
+      break;
+
+    case s_req_fragment:
+      if (IS_URL_CHAR(ch)) {
+        return s;
+      }
+
+      switch (ch) {
+        case '?':
+        case '#':
+          return s;
+      }
+
+      break;
+
+    default:
+      break;
+  }
+
+  /* We should never fall out of the switch above unless there's an error */
+  return s_dead;
+}
+
+size_t http_parser_execute (http_parser *parser,
+                            const http_parser_settings *settings,
+                            const char *data,
+                            size_t len)
+{
+  char c, ch;
+  int8_t unhex_val;
+  const char *p = data;
+  const char *header_field_mark = 0;
+  const char *header_value_mark = 0;
+  const char *url_mark = 0;
+  const char *body_mark = 0;
+
+  /* We're in an error state. Don't bother doing anything. */
+  if (HTTP_PARSER_ERRNO(parser) != HPE_OK) {
+    return 0;
+  }
+
+  if (len == 0) {
+    switch (parser->state) {
+      case s_body_identity_eof:
+        /* Use of CALLBACK_NOTIFY() here would erroneously return 1 byte read if
+         * we got paused.
+         */
+        CALLBACK_NOTIFY_NOADVANCE(message_complete);
+        return 0;
+
+      case s_dead:
+      case s_start_req_or_res:
+      case s_start_res:
+      case s_start_req:
+        return 0;
+
+      default:
+        SET_ERRNO(HPE_INVALID_EOF_STATE);
+        return 1;
+    }
+  }
+
+
+  if (parser->state == s_header_field)
+    header_field_mark = data;
+  if (parser->state == s_header_value)
+    header_value_mark = data;
+  switch (parser->state) {
+  case s_req_path:
+  case s_req_schema:
+  case s_req_schema_slash:
+  case s_req_schema_slash_slash:
+  case s_req_server_start:
+  case s_req_server:
+  case s_req_server_with_at:
+  case s_req_query_string_start:
+  case s_req_query_string:
+  case s_req_fragment_start:
+  case s_req_fragment:
+    url_mark = data;
+    break;
+  }
+
+  for (p=data; p != data + len; p++) {
+    ch = *p;
+
+    if (PARSING_HEADER(parser->state)) {
+      ++parser->nread;
+      /* Buffer overflow attack */
+      if (parser->nread > HTTP_MAX_HEADER_SIZE) {
+        SET_ERRNO(HPE_HEADER_OVERFLOW);
+        goto error;
+      }
+    }
+
+    reexecute_byte:
+    switch (parser->state) {
+
+      case s_dead:
+        /* this state is used after a 'Connection: close' message
+         * the parser will error out if it reads another message
+         */
+        if (ch == CR || ch == LF)
+          break;
+
+        SET_ERRNO(HPE_CLOSED_CONNECTION);
+        goto error;
+
+      case s_start_req_or_res:
+      {
+        if (ch == CR || ch == LF)
+          break;
+        parser->flags = 0;
+        parser->content_length = ULLONG_MAX;
+
+        if (ch == 'H') {
+          parser->state = s_res_or_resp_H;
+
+          CALLBACK_NOTIFY(message_begin);
+        } else {
+          parser->type = HTTP_REQUEST;
+          parser->state = s_start_req;
+          goto reexecute_byte;
+        }
+
+        break;
+      }
+
+      case s_res_or_resp_H:
+        if (ch == 'T') {
+          parser->type = HTTP_RESPONSE;
+          parser->state = s_res_HT;
+        } else {
+          if (ch != 'E') {
+            SET_ERRNO(HPE_INVALID_CONSTANT);
+            goto error;
+          }
+
+          parser->type = HTTP_REQUEST;
+          parser->method = HTTP_HEAD;
+          parser->index = 2;
+          parser->state = s_req_method;
+        }
+        break;
+
+      case s_start_res:
+      {
+        parser->flags = 0;
+        parser->content_length = ULLONG_MAX;
+
+        switch (ch) {
+          case 'H':
+            parser->state = s_res_H;
+            break;
+
+          case CR:
+          case LF:
+            break;
+
+          default:
+            SET_ERRNO(HPE_INVALID_CONSTANT);
+            goto error;
+        }
+
+        CALLBACK_NOTIFY(message_begin);
+        break;
+      }
+
+      case s_res_H:
+        STRICT_CHECK(ch != 'T');
+        parser->state = s_res_HT;
+        break;
+
+      case s_res_HT:
+        STRICT_CHECK(ch != 'T');
+        parser->state = s_res_HTT;
+        break;
+
+      case s_res_HTT:
+        STRICT_CHECK(ch != 'P');
+        parser->state = s_res_HTTP;
+        break;
+
+      case s_res_HTTP:
+        STRICT_CHECK(ch != '/');
+        parser->state = s_res_first_http_major;
+        break;
+
+      case s_res_first_http_major:
+        if (ch < '0' || ch > '9') {
+          SET_ERRNO(HPE_INVALID_VERSION);
+          goto error;
+        }
+
+        parser->http_major = ch - '0';
+        parser->state = s_res_http_major;
+        break;
+
+      /* major HTTP version or dot */
+      case s_res_http_major:
+      {
+        if (ch == '.') {
+          parser->state = s_res_first_http_minor;
+          break;
+        }
+
+        if (!IS_NUM(ch)) {
+          SET_ERRNO(HPE_INVALID_VERSION);
+          goto error;
+        }
+
+        parser->http_major *= 10;
+        parser->http_major += ch - '0';
+
+        if (parser->http_major > 999) {
+          SET_ERRNO(HPE_INVALID_VERSION);
+          goto error;
+        }
+
+        break;
+      }
+
+      /* first digit of minor HTTP version */
+      case s_res_first_http_minor:
+        if (!IS_NUM(ch)) {
+          SET_ERRNO(HPE_INVALID_VERSION);
+          goto error;
+        }
+
+        parser->http_minor = ch - '0';
+        parser->state = s_res_http_minor;
+        break;
+
+      /* minor HTTP version or end of request line */
+      case s_res_http_minor:
+      {
+        if (ch == ' ') {
+          parser->state = s_res_first_status_code;
+          break;
+        }
+
+        if (!IS_NUM(ch)) {
+          SET_ERRNO(HPE_INVALID_VERSION);
+          goto error;
+        }
+
+        parser->http_minor *= 10;
+        parser->http_minor += ch - '0';
+
+        if (parser->http_minor > 999) {
+          SET_ERRNO(HPE_INVALID_VERSION);
+          goto error;
+        }
+
+        break;
+      }
+
+      case s_res_first_status_code:
+      {
+        if (!IS_NUM(ch)) {
+          if (ch == ' ') {
+            break;
+          }
+
+          SET_ERRNO(HPE_INVALID_STATUS);
+          goto error;
+        }
+        parser->status_code = ch - '0';
+        parser->state = s_res_status_code;
+        break;
+      }
+
+      case s_res_status_code:
+      {
+        if (!IS_NUM(ch)) {
+          switch (ch) {
+            case ' ':
+              parser->state = s_res_status;
+              break;
+            case CR:
+              parser->state = s_res_line_almost_done;
+              break;
+            case LF:
+              parser->state = s_header_field_start;
+              break;
+            default:
+              SET_ERRNO(HPE_INVALID_STATUS);
+              goto error;
+          }
+          break;
+        }
+
+        parser->status_code *= 10;
+        parser->status_code += ch - '0';
+
+        if (parser->status_code > 999) {
+          SET_ERRNO(HPE_INVALID_STATUS);
+          goto error;
+        }
+
+        break;
+      }
+
+      case s_res_status:
+        /* the human readable status. e.g. "NOT FOUND"
+         * we are not humans so just ignore this */
+        if (ch == CR) {
+          parser->state = s_res_line_almost_done;
+          break;
+        }
+
+        if (ch == LF) {
+          parser->state = s_header_field_start;
+          break;
+        }
+        break;
+
+      case s_res_line_almost_done:
+        STRICT_CHECK(ch != LF);
+        parser->state = s_header_field_start;
+        break;
+
+      case s_start_req:
+      {
+        if (ch == CR || ch == LF)
+          break;
+        parser->flags = 0;
+        parser->content_length = ULLONG_MAX;
+
+        if (!IS_ALPHA(ch)) {
+          SET_ERRNO(HPE_INVALID_METHOD);
+          goto error;
+        }
+
+        parser->method = (enum http_method) 0;
+        parser->index = 1;
+        switch (ch) {
+          case 'C': parser->method = HTTP_CONNECT; /* or COPY, CHECKOUT */ break;
+          case 'D': parser->method = HTTP_DELETE; break;
+          case 'G': parser->method = HTTP_GET; break;
+          case 'H': parser->method = HTTP_HEAD; break;
+          case 'L': parser->method = HTTP_LOCK; break;
+          case 'M': parser->method = HTTP_MKCOL; /* or MOVE, MKACTIVITY, MERGE, M-SEARCH */ break;
+          case 'N': parser->method = HTTP_NOTIFY; break;
+          case 'O': parser->method = HTTP_OPTIONS; break;
+          case 'P': parser->method = HTTP_POST;
+            /* or PROPFIND|PROPPATCH|PUT|PATCH|PURGE */
+            break;
+          case 'R': parser->method = HTTP_REPORT; break;
+          case 'S': parser->method = HTTP_SUBSCRIBE; /* or SEARCH */ break;
+          case 'T': parser->method = HTTP_TRACE; break;
+          case 'U': parser->method = HTTP_UNLOCK; /* or UNSUBSCRIBE */ break;
+          default:
+            SET_ERRNO(HPE_INVALID_METHOD);
+            goto error;
+        }
+        parser->state = s_req_method;
+
+        CALLBACK_NOTIFY(message_begin);
+
+        break;
+      }
+
+      case s_req_method:
+      {
+        const char *matcher;
+        if (ch == '\0') {
+          SET_ERRNO(HPE_INVALID_METHOD);
+          goto error;
+        }
+
+        matcher = method_strings[parser->method];
+        if (ch == ' ' && matcher[parser->index] == '\0') {
+          parser->state = s_req_spaces_before_url;
+        } else if (ch == matcher[parser->index]) {
+          ; /* nada */
+        } else if (parser->method == HTTP_CONNECT) {
+          if (parser->index == 1 && ch == 'H') {
+            parser->method = HTTP_CHECKOUT;
+          } else if (parser->index == 2  && ch == 'P') {
+            parser->method = HTTP_COPY;
+          } else {
+            goto error;
+          }
+        } else if (parser->method == HTTP_MKCOL) {
+          if (parser->index == 1 && ch == 'O') {
+            parser->method = HTTP_MOVE;
+          } else if (parser->index == 1 && ch == 'E') {
+            parser->method = HTTP_MERGE;
+          } else if (parser->index == 1 && ch == '-') {
+            parser->method = HTTP_MSEARCH;
+          } else if (parser->index == 2 && ch == 'A') {
+            parser->method = HTTP_MKACTIVITY;
+          } else {
+            goto error;
+          }
+        } else if (parser->method == HTTP_SUBSCRIBE) {
+          if (parser->index == 1 && ch == 'E') {
+            parser->method = HTTP_SEARCH;
+          } else {
+            goto error;
+          }
+        } else if (parser->index == 1 && parser->method == HTTP_POST) {
+          if (ch == 'R') {
+            parser->method = HTTP_PROPFIND; /* or HTTP_PROPPATCH */
+          } else if (ch == 'U') {
+            parser->method = HTTP_PUT; /* or HTTP_PURGE */
+          } else if (ch == 'A') {
+            parser->method = HTTP_PATCH;
+          } else {
+            goto error;
+          }
+        } else if (parser->index == 2) {
+          if (parser->method == HTTP_PUT) {
+            if (ch == 'R') parser->method = HTTP_PURGE;
+          } else if (parser->method == HTTP_UNLOCK) {
+            if (ch == 'S') parser->method = HTTP_UNSUBSCRIBE;
+          }
+        } else if (parser->index == 4 && parser->method == HTTP_PROPFIND && ch == 'P') {
+          parser->method = HTTP_PROPPATCH;
+        } else {
+          SET_ERRNO(HPE_INVALID_METHOD);
+          goto error;
+        }
+
+        ++parser->index;
+        break;
+      }
+
+      case s_req_spaces_before_url:
+      {
+        if (ch == ' ') break;
+
+        MARK(url);
+        if (parser->method == HTTP_CONNECT) {
+          parser->state = s_req_server_start;
+        }
+
+        parser->state = parse_url_char((enum state)parser->state, ch);
+        if (parser->state == s_dead) {
+          SET_ERRNO(HPE_INVALID_URL);
+          goto error;
+        }
+
+        break;
+      }
+
+      case s_req_schema:
+      case s_req_schema_slash:
+      case s_req_schema_slash_slash:
+      case s_req_server_start:
+      {
+        switch (ch) {
+          /* No whitespace allowed here */
+          case ' ':
+          case CR:
+          case LF:
+            SET_ERRNO(HPE_INVALID_URL);
+            goto error;
+          default:
+            parser->state = parse_url_char((enum state)parser->state, ch);
+            if (parser->state == s_dead) {
+              SET_ERRNO(HPE_INVALID_URL);
+              goto error;
+            }
+        }
+
+        break;
+      }
+
+      case s_req_server:
+      case s_req_server_with_at:
+      case s_req_path:
+      case s_req_query_string_start:
+      case s_req_query_string:
+      case s_req_fragment_start:
+      case s_req_fragment:
+      {
+        switch (ch) {
+          case ' ':
+            parser->state = s_req_http_start;
+            CALLBACK_DATA(url);
+            break;
+          case CR:
+          case LF:
+            parser->http_major = 0;
+            parser->http_minor = 9;
+            parser->state = (ch == CR) ?
+              s_req_line_almost_done :
+              s_header_field_start;
+            CALLBACK_DATA(url);
+            break;
+          default:
+            parser->state = parse_url_char((enum state)parser->state, ch);
+            if (parser->state == s_dead) {
+              SET_ERRNO(HPE_INVALID_URL);
+              goto error;
+            }
+        }
+        break;
+      }
+
+      case s_req_http_start:
+        switch (ch) {
+          case 'H':
+            parser->state = s_req_http_H;
+            break;
+          case ' ':
+            break;
+          default:
+            SET_ERRNO(HPE_INVALID_CONSTANT);
+            goto error;
+        }
+        break;
+
+      case s_req_http_H:
+        STRICT_CHECK(ch != 'T');
+        parser->state = s_req_http_HT;
+        break;
+
+      case s_req_http_HT:
+        STRICT_CHECK(ch != 'T');
+        parser->state = s_req_http_HTT;
+        break;
+
+      case s_req_http_HTT:
+        STRICT_CHECK(ch != 'P');
+        parser->state = s_req_http_HTTP;
+        break;
+
+      case s_req_http_HTTP:
+        STRICT_CHECK(ch != '/');
+        parser->state = s_req_first_http_major;
+        break;
+
+      /* first digit of major HTTP version */
+      case s_req_first_http_major:
+        if (ch < '1' || ch > '9') {
+          SET_ERRNO(HPE_INVALID_VERSION);
+          goto error;
+        }
+
+        parser->http_major = ch - '0';
+        parser->state = s_req_http_major;
+        break;
+
+      /* major HTTP version or dot */
+      case s_req_http_major:
+      {
+        if (ch == '.') {
+          parser->state = s_req_first_http_minor;
+          break;
+        }
+
+        if (!IS_NUM(ch)) {
+          SET_ERRNO(HPE_INVALID_VERSION);
+          goto error;
+        }
+
+        parser->http_major *= 10;
+        parser->http_major += ch - '0';
+
+        if (parser->http_major > 999) {
+          SET_ERRNO(HPE_INVALID_VERSION);
+          goto error;
+        }
+
+        break;
+      }
+
+      /* first digit of minor HTTP version */
+      case s_req_first_http_minor:
+        if (!IS_NUM(ch)) {
+          SET_ERRNO(HPE_INVALID_VERSION);
+          goto error;
+        }
+
+        parser->http_minor = ch - '0';
+        parser->state = s_req_http_minor;
+        break;
+
+      /* minor HTTP version or end of request line */
+      case s_req_http_minor:
+      {
+        if (ch == CR) {
+          parser->state = s_req_line_almost_done;
+          break;
+        }
+
+        if (ch == LF) {
+          parser->state = s_header_field_start;
+          break;
+        }
+
+        /* XXX allow spaces after digit? */
+
+        if (!IS_NUM(ch)) {
+          SET_ERRNO(HPE_INVALID_VERSION);
+          goto error;
+        }
+
+        parser->http_minor *= 10;
+        parser->http_minor += ch - '0';
+
+        if (parser->http_minor > 999) {
+          SET_ERRNO(HPE_INVALID_VERSION);
+          goto error;
+        }
+
+        break;
+      }
+
+      /* end of request line */
+      case s_req_line_almost_done:
+      {
+        if (ch != LF) {
+          SET_ERRNO(HPE_LF_EXPECTED);
+          goto error;
+        }
+
+        parser->state = s_header_field_start;
+        break;
+      }
+
+      case s_header_field_start:
+      {
+        if (ch == CR) {
+          parser->state = s_headers_almost_done;
+          break;
+        }
+
+        if (ch == LF) {
+          /* they might be just sending \n instead of \r\n so this would be
+           * the second \n to denote the end of headers*/
+          parser->state = s_headers_almost_done;
+          goto reexecute_byte;
+        }
+
+        c = TOKEN(ch);
+
+        if (!c) {
+          SET_ERRNO(HPE_INVALID_HEADER_TOKEN);
+          goto error;
+        }
+
+        MARK(header_field);
+
+        parser->index = 0;
+        parser->state = s_header_field;
+
+        switch (c) {
+          case 'c':
+            parser->header_state = h_C;
+            break;
+
+          case 'p':
+            parser->header_state = h_matching_proxy_connection;
+            break;
+
+          case 't':
+            parser->header_state = h_matching_transfer_encoding;
+            break;
+
+          case 'u':
+            parser->header_state = h_matching_upgrade;
+            break;
+
+          default:
+            parser->header_state = h_general;
+            break;
+        }
+        break;
+      }
+
+      case s_header_field:
+      {
+        c = TOKEN(ch);
+
+        if (c) {
+          switch (parser->header_state) {
+            case h_general:
+              break;
+
+            case h_C:
+              parser->index++;
+              parser->header_state = (c == 'o' ? h_CO : h_general);
+              break;
+
+            case h_CO:
+              parser->index++;
+              parser->header_state = (c == 'n' ? h_CON : h_general);
+              break;
+
+            case h_CON:
+              parser->index++;
+              switch (c) {
+                case 'n':
+                  parser->header_state = h_matching_connection;
+                  break;
+                case 't':
+                  parser->header_state = h_matching_content_length;
+                  break;
+                default:
+                  parser->header_state = h_general;
+                  break;
+              }
+              break;
+
+            /* connection */
+
+            case h_matching_connection:
+              parser->index++;
+              if (parser->index > sizeof(CONNECTION)-1
+                  || c != CONNECTION[parser->index]) {
+                parser->header_state = h_general;
+              } else if (parser->index == sizeof(CONNECTION)-2) {
+                parser->header_state = h_connection;
+              }
+              break;
+
+            /* proxy-connection */
+
+            case h_matching_proxy_connection:
+              parser->index++;
+              if (parser->index > sizeof(PROXY_CONNECTION)-1
+                  || c != PROXY_CONNECTION[parser->index]) {
+                parser->header_state = h_general;
+              } else if (parser->index == sizeof(PROXY_CONNECTION)-2) {
+                parser->header_state = h_connection;
+              }
+              break;
+
+            /* content-length */
+
+            case h_matching_content_length:
+              parser->index++;
+              if (parser->index > sizeof(CONTENT_LENGTH)-1
+                  || c != CONTENT_LENGTH[parser->index]) {
+                parser->header_state = h_general;
+              } else if (parser->index == sizeof(CONTENT_LENGTH)-2) {
+                parser->header_state = h_content_length;
+              }
+              break;
+
+            /* transfer-encoding */
+
+            case h_matching_transfer_encoding:
+              parser->index++;
+              if (parser->index > sizeof(TRANSFER_ENCODING)-1
+                  || c != TRANSFER_ENCODING[parser->index]) {
+                parser->header_state = h_general;
+              } else if (parser->index == sizeof(TRANSFER_ENCODING)-2) {
+                parser->header_state = h_transfer_encoding;
+              }
+              break;
+
+            /* upgrade */
+
+            case h_matching_upgrade:
+              parser->index++;
+              if (parser->index > sizeof(UPGRADE)-1
+                  || c != UPGRADE[parser->index]) {
+                parser->header_state = h_general;
+              } else if (parser->index == sizeof(UPGRADE)-2) {
+                parser->header_state = h_upgrade;
+              }
+              break;
+
+            case h_connection:
+            case h_content_length:
+            case h_transfer_encoding:
+            case h_upgrade:
+              if (ch != ' ') parser->header_state = h_general;
+              break;
+
+            default:
+              assert(0 && "Unknown header_state");
+              break;
+          }
+          break;
+        }
+
+        if (ch == ':') {
+          parser->state = s_header_value_start;
+          CALLBACK_DATA(header_field);
+          break;
+        }
+
+        if (ch == CR) {
+          parser->state = s_header_almost_done;
+          CALLBACK_DATA(header_field);
+          break;
+        }
+
+        if (ch == LF) {
+          parser->state = s_header_field_start;
+          CALLBACK_DATA(header_field);
+          break;
+        }
+
+        SET_ERRNO(HPE_INVALID_HEADER_TOKEN);
+        goto error;
+      }
+
+      case s_header_value_start:
+      {
+        if (ch == ' ' || ch == '\t') break;
+
+        MARK(header_value);
+
+        parser->state = s_header_value;
+        parser->index = 0;
+
+        if (ch == CR) {
+          parser->header_state = h_general;
+          parser->state = s_header_almost_done;
+          CALLBACK_DATA(header_value);
+          break;
+        }
+
+        if (ch == LF) {
+          parser->state = s_header_field_start;
+          CALLBACK_DATA(header_value);
+          break;
+        }
+
+        c = LOWER(ch);
+
+        switch (parser->header_state) {
+          case h_upgrade:
+            parser->flags |= F_UPGRADE;
+            parser->header_state = h_general;
+            break;
+
+          case h_transfer_encoding:
+            /* looking for 'Transfer-Encoding: chunked' */
+            if ('c' == c) {
+              parser->header_state = h_matching_transfer_encoding_chunked;
+            } else {
+              parser->header_state = h_general;
+            }
+            break;
+
+          case h_content_length:
+            if (!IS_NUM(ch)) {
+              SET_ERRNO(HPE_INVALID_CONTENT_LENGTH);
+              goto error;
+            }
+
+            parser->content_length = ch - '0';
+            break;
+
+          case h_connection:
+            /* looking for 'Connection: keep-alive' */
+            if (c == 'k') {
+              parser->header_state = h_matching_connection_keep_alive;
+            /* looking for 'Connection: close' */
+            } else if (c == 'c') {
+              parser->header_state = h_matching_connection_close;
+            } else {
+              parser->header_state = h_general;
+            }
+            break;
+
+          default:
+            parser->header_state = h_general;
+            break;
+        }
+        break;
+      }
+
+      case s_header_value:
+      {
+
+        if (ch == CR) {
+          parser->state = s_header_almost_done;
+          CALLBACK_DATA(header_value);
+          break;
+        }
+
+        if (ch == LF) {
+          parser->state = s_header_almost_done;
+          CALLBACK_DATA_NOADVANCE(header_value);
+          goto reexecute_byte;
+        }
+
+        c = LOWER(ch);
+
+        switch (parser->header_state) {
+          case h_general:
+            break;
+
+          case h_connection:
+          case h_transfer_encoding:
+            assert(0 && "Shouldn't get here.");
+            break;
+
+          case h_content_length:
+          {
+            uint64_t t;
+
+            if (ch == ' ') break;
+
+            if (!IS_NUM(ch)) {
+              SET_ERRNO(HPE_INVALID_CONTENT_LENGTH);
+              goto error;
+            }
+
+            t = parser->content_length;
+            t *= 10;
+            t += ch - '0';
+
+            /* Overflow? */
+            if (t < parser->content_length || t == ULLONG_MAX) {
+              SET_ERRNO(HPE_INVALID_CONTENT_LENGTH);
+              goto error;
+            }
+
+            parser->content_length = t;
+            break;
+          }
+
+          /* Transfer-Encoding: chunked */
+          case h_matching_transfer_encoding_chunked:
+            parser->index++;
+            if (parser->index > sizeof(CHUNKED)-1
+                || c != CHUNKED[parser->index]) {
+              parser->header_state = h_general;
+            } else if (parser->index == sizeof(CHUNKED)-2) {
+              parser->header_state = h_transfer_encoding_chunked;
+            }
+            break;
+
+          /* looking for 'Connection: keep-alive' */
+          case h_matching_connection_keep_alive:
+            parser->index++;
+            if (parser->index > sizeof(KEEP_ALIVE)-1
+                || c != KEEP_ALIVE[parser->index]) {
+              parser->header_state = h_general;
+            } else if (parser->index == sizeof(KEEP_ALIVE)-2) {
+              parser->header_state = h_connection_keep_alive;
+            }
+            break;
+
+          /* looking for 'Connection: close' */
+          case h_matching_connection_close:
+            parser->index++;
+            if (parser->index > sizeof(CLOSE)-1 || c != CLOSE[parser->index]) {
+              parser->header_state = h_general;
+            } else if (parser->index == sizeof(CLOSE)-2) {
+              parser->header_state = h_connection_close;
+            }
+            break;
+
+          case h_transfer_encoding_chunked:
+          case h_connection_keep_alive:
+          case h_connection_close:
+            if (ch != ' ') parser->header_state = h_general;
+            break;
+
+          default:
+            parser->state = s_header_value;
+            parser->header_state = h_general;
+            break;
+        }
+        break;
+      }
+
+      case s_header_almost_done:
+      {
+        STRICT_CHECK(ch != LF);
+
+        parser->state = s_header_value_lws;
+
+        switch (parser->header_state) {
+          case h_connection_keep_alive:
+            parser->flags |= F_CONNECTION_KEEP_ALIVE;
+            break;
+          case h_connection_close:
+            parser->flags |= F_CONNECTION_CLOSE;
+            break;
+          case h_transfer_encoding_chunked:
+            parser->flags |= F_CHUNKED;
+            break;
+          default:
+            break;
+        }
+
+        break;
+      }
+
+      case s_header_value_lws:
+      {
+        if (ch == ' ' || ch == '\t')
+          parser->state = s_header_value_start;
+        else
+        {
+          parser->state = s_header_field_start;
+          goto reexecute_byte;
+        }
+        break;
+      }
+
+      case s_headers_almost_done:
+      {
+        STRICT_CHECK(ch != LF);
+
+        if (parser->flags & F_TRAILING) {
+          /* End of a chunked request */
+          parser->state = NEW_MESSAGE();
+          CALLBACK_NOTIFY(message_complete);
+          break;
+        }
+
+        parser->state = s_headers_done;
+
+        /* Set this here so that on_headers_complete() callbacks can see it */
+        parser->upgrade =
+          (parser->flags & F_UPGRADE || parser->method == HTTP_CONNECT);
+
+        /* Here we call the headers_complete callback. This is somewhat
+         * different than other callbacks because if the user returns 1, we
+         * will interpret that as saying that this message has no body. This
+         * is needed for the annoying case of recieving a response to a HEAD
+         * request.
+         *
+         * We'd like to use CALLBACK_NOTIFY_NOADVANCE() here but we cannot, so
+         * we have to simulate it by handling a change in errno below.
+         */
+        if (settings->on_headers_complete) {
+          switch (settings->on_headers_complete(parser)) {
+            case 0:
+              break;
+
+            case 1:
+              parser->flags |= F_SKIPBODY;
+              break;
+
+            default:
+              SET_ERRNO(HPE_CB_headers_complete);
+              return p - data; /* Error */
+          }
+        }
+
+        if (HTTP_PARSER_ERRNO(parser) != HPE_OK) {
+          return p - data;
+        }
+
+        goto reexecute_byte;
+      }
+
+      case s_headers_done:
+      {
+        STRICT_CHECK(ch != LF);
+
+        parser->nread = 0;
+
+        /* Exit, the rest of the connect is in a different protocol. */
+        if (parser->upgrade) {
+          parser->state = NEW_MESSAGE();
+          CALLBACK_NOTIFY(message_complete);
+          return (p - data) + 1;
+        }
+
+        if (parser->flags & F_SKIPBODY) {
+          parser->state = NEW_MESSAGE();
+          CALLBACK_NOTIFY(message_complete);
+        } else if (parser->flags & F_CHUNKED) {
+          /* chunked encoding - ignore Content-Length header */
+          parser->state = s_chunk_size_start;
+        } else {
+          if (parser->content_length == 0) {
+            /* Content-Length header given but zero: Content-Length: 0\r\n */
+            parser->state = NEW_MESSAGE();
+            CALLBACK_NOTIFY(message_complete);
+          } else if (parser->content_length != ULLONG_MAX) {
+            /* Content-Length header given and non-zero */
+            parser->state = s_body_identity;
+          } else {
+            if (parser->type == HTTP_REQUEST ||
+                !http_message_needs_eof(parser)) {
+              /* Assume content-length 0 - read the next */
+              parser->state = NEW_MESSAGE();
+              CALLBACK_NOTIFY(message_complete);
+            } else {
+              /* Read body until EOF */
+              parser->state = s_body_identity_eof;
+            }
+          }
+        }
+
+        break;
+      }
+
+      case s_body_identity:
+      {
+        uint64_t to_read = MIN(parser->content_length,
+                               (uint64_t) ((data + len) - p));
+
+        assert(parser->content_length != 0
+            && parser->content_length != ULLONG_MAX);
+
+        /* The difference between advancing content_length and p is because
+         * the latter will automaticaly advance on the next loop iteration.
+         * Further, if content_length ends up at 0, we want to see the last
+         * byte again for our message complete callback.
+         */
+        MARK(body);
+        parser->content_length -= to_read;
+        p += to_read - 1;
+
+        if (parser->content_length == 0) {
+          parser->state = s_message_done;
+
+          /* Mimic CALLBACK_DATA_NOADVANCE() but with one extra byte.
+           *
+           * The alternative to doing this is to wait for the next byte to
+           * trigger the data callback, just as in every other case. The
+           * problem with this is that this makes it difficult for the test
+           * harness to distinguish between complete-on-EOF and
+           * complete-on-length. It's not clear that this distinction is
+           * important for applications, but let's keep it for now.
+           */
+          CALLBACK_DATA_(body, p - body_mark + 1, p - data);
+          goto reexecute_byte;
+        }
+
+        break;
+      }
+
+      /* read until EOF */
+      case s_body_identity_eof:
+        MARK(body);
+        p = data + len - 1;
+
+        break;
+
+      case s_message_done:
+        parser->state = NEW_MESSAGE();
+        CALLBACK_NOTIFY(message_complete);
+        break;
+
+      case s_chunk_size_start:
+      {
+        assert(parser->nread == 1);
+        assert(parser->flags & F_CHUNKED);
+
+        unhex_val = unhex[(unsigned char)ch];
+        if (unhex_val == -1) {
+          SET_ERRNO(HPE_INVALID_CHUNK_SIZE);
+          goto error;
+        }
+
+        parser->content_length = unhex_val;
+        parser->state = s_chunk_size;
+        break;
+      }
+
+      case s_chunk_size:
+      {
+        uint64_t t;
+
+        assert(parser->flags & F_CHUNKED);
+
+        if (ch == CR) {
+          parser->state = s_chunk_size_almost_done;
+          break;
+        }
+
+        unhex_val = unhex[(unsigned char)ch];
+
+        if (unhex_val == -1) {
+          if (ch == ';' || ch == ' ') {
+            parser->state = s_chunk_parameters;
+            break;
+          }
+
+          SET_ERRNO(HPE_INVALID_CHUNK_SIZE);
+          goto error;
+        }
+
+        t = parser->content_length;
+        t *= 16;
+        t += unhex_val;
+
+        /* Overflow? */
+        if (t < parser->content_length || t == ULLONG_MAX) {
+          SET_ERRNO(HPE_INVALID_CONTENT_LENGTH);
+          goto error;
+        }
+
+        parser->content_length = t;
+        break;
+      }
+
+      case s_chunk_parameters:
+      {
+        assert(parser->flags & F_CHUNKED);
+        /* just ignore this. TODO check for overflow */
+        if (ch == CR) {
+          parser->state = s_chunk_size_almost_done;
+          break;
+        }
+        break;
+      }
+
+      case s_chunk_size_almost_done:
+      {
+        assert(parser->flags & F_CHUNKED);
+        STRICT_CHECK(ch != LF);
+
+        parser->nread = 0;
+
+        if (parser->content_length == 0) {
+          parser->flags |= F_TRAILING;
+          parser->state = s_header_field_start;
+        } else {
+          parser->state = s_chunk_data;
+        }
+        break;
+      }
+
+      case s_chunk_data:
+      {
+        uint64_t to_read = MIN(parser->content_length,
+                               (uint64_t) ((data + len) - p));
+
+        assert(parser->flags & F_CHUNKED);
+        assert(parser->content_length != 0
+            && parser->content_length != ULLONG_MAX);
+
+        /* See the explanation in s_body_identity for why the content
+         * length and data pointers are managed this way.
+         */
+        MARK(body);
+        parser->content_length -= to_read;
+        p += to_read - 1;
+
+        if (parser->content_length == 0) {
+          parser->state = s_chunk_data_almost_done;
+        }
+
+        break;
+      }
+
+      case s_chunk_data_almost_done:
+        assert(parser->flags & F_CHUNKED);
+        assert(parser->content_length == 0);
+        STRICT_CHECK(ch != CR);
+        parser->state = s_chunk_data_done;
+        CALLBACK_DATA(body);
+        break;
+
+      case s_chunk_data_done:
+        assert(parser->flags & F_CHUNKED);
+        STRICT_CHECK(ch != LF);
+        parser->nread = 0;
+        parser->state = s_chunk_size_start;
+        break;
+
+      default:
+        assert(0 && "unhandled state");
+        SET_ERRNO(HPE_INVALID_INTERNAL_STATE);
+        goto error;
+    }
+  }
+
+  /* Run callbacks for any marks that we have leftover after we ran our of
+   * bytes. There should be at most one of these set, so it's OK to invoke
+   * them in series (unset marks will not result in callbacks).
+   *
+   * We use the NOADVANCE() variety of callbacks here because 'p' has already
+   * overflowed 'data' and this allows us to correct for the off-by-one that
+   * we'd otherwise have (since CALLBACK_DATA() is meant to be run with a 'p'
+   * value that's in-bounds).
+   */
+
+  assert(((header_field_mark ? 1 : 0) +
+          (header_value_mark ? 1 : 0) +
+          (url_mark ? 1 : 0)  +
+          (body_mark ? 1 : 0)) <= 1);
+
+  CALLBACK_DATA_NOADVANCE(header_field);
+  CALLBACK_DATA_NOADVANCE(header_value);
+  CALLBACK_DATA_NOADVANCE(url);
+  CALLBACK_DATA_NOADVANCE(body);
+
+  return len;
+
+error:
+  if (HTTP_PARSER_ERRNO(parser) == HPE_OK) {
+    SET_ERRNO(HPE_UNKNOWN);
+  }
+
+  return (p - data);
+}
+
+
+/* Does the parser need to see an EOF to find the end of the message? */
+int
+http_message_needs_eof (const http_parser *parser)
+{
+  if (parser->type == HTTP_REQUEST) {
+    return 0;
+  }
+
+  /* See RFC 2616 section 4.4 */
+  if (parser->status_code / 100 == 1 || /* 1xx e.g. Continue */
+      parser->status_code == 204 ||     /* No Content */
+      parser->status_code == 304 ||     /* Not Modified */
+      parser->flags & F_SKIPBODY) {     /* response to a HEAD request */
+    return 0;
+  }
+
+  if ((parser->flags & F_CHUNKED) || parser->content_length != ULLONG_MAX) {
+    return 0;
+  }
+
+  return 1;
+}
+
+
+int
+http_should_keep_alive (const http_parser *parser)
+{
+  if (parser->http_major > 0 && parser->http_minor > 0) {
+    /* HTTP/1.1 */
+    if (parser->flags & F_CONNECTION_CLOSE) {
+      return 0;
+    }
+  } else {
+    /* HTTP/1.0 or earlier */
+    if (!(parser->flags & F_CONNECTION_KEEP_ALIVE)) {
+      return 0;
+    }
+  }
+
+  return !http_message_needs_eof(parser);
+}
+
+
+const char *
+http_method_str (enum http_method m)
+{
+  return ELEM_AT(method_strings, m, "<unknown>");
+}
+
+
+void
+http_parser_init (http_parser *parser, enum http_parser_type t)
+{
+  void *data = parser->data; /* preserve application data */
+  memset(parser, 0, sizeof(*parser));
+  parser->data = data;
+  parser->type = t;
+  parser->state = (t == HTTP_REQUEST ? s_start_req : (t == HTTP_RESPONSE ? s_start_res : s_start_req_or_res));
+  parser->http_errno = HPE_OK;
+}
+
+const char *
+http_errno_name(enum http_errno err) {
+  assert(err < (sizeof(http_strerror_tab)/sizeof(http_strerror_tab[0])));
+  return http_strerror_tab[err].name;
+}
+
+const char *
+http_errno_description(enum http_errno err) {
+  assert(err < (sizeof(http_strerror_tab)/sizeof(http_strerror_tab[0])));
+  return http_strerror_tab[err].description;
+}
+
+static enum http_host_state
+http_parse_host_char(enum http_host_state s, const char ch) {
+  switch(s) {
+    case s_http_userinfo:
+    case s_http_userinfo_start:
+      if (ch == '@') {
+        return s_http_host_start;
+      }
+
+      if (IS_USERINFO_CHAR(ch)) {
+        return s_http_userinfo;
+      }
+      break;
+
+    case s_http_host_start:
+      if (ch == '[') {
+        return s_http_host_v6_start;
+      }
+
+      if (IS_HOST_CHAR(ch)) {
+        return s_http_host;
+      }
+
+      break;
+
+    case s_http_host:
+      if (IS_HOST_CHAR(ch)) {
+        return s_http_host;
+      }
+
+    /* FALLTHROUGH */
+    case s_http_host_v6_end:
+      if (ch == ':') {
+        return s_http_host_port_start;
+      }
+
+      break;
+
+    case s_http_host_v6:
+      if (ch == ']') {
+        return s_http_host_v6_end;
+      }
+
+    /* FALLTHROUGH */
+    case s_http_host_v6_start:
+      if (IS_HEX(ch) || ch == ':') {
+        return s_http_host_v6;
+      }
+
+      break;
+
+    case s_http_host_port:
+    case s_http_host_port_start:
+      if (IS_NUM(ch)) {
+        return s_http_host_port;
+      }
+
+      break;
+
+    default:
+      break;
+  }
+  return s_http_host_dead;
+}
+
+static int
+http_parse_host(const char * buf, struct http_parser_url *u, int found_at) {
+  enum http_host_state s;
+
+  const char *p;
+  size_t buflen = u->field_data[UF_HOST].off + u->field_data[UF_HOST].len;
+
+  u->field_data[UF_HOST].len = 0;
+
+  s = found_at ? s_http_userinfo_start : s_http_host_start;
+
+  for (p = buf + u->field_data[UF_HOST].off; p < buf + buflen; p++) {
+    enum http_host_state new_s = http_parse_host_char(s, *p);
+
+    if (new_s == s_http_host_dead) {
+      return 1;
+    }
+
+    switch(new_s) {
+      case s_http_host:
+        if (s != s_http_host) {
+          u->field_data[UF_HOST].off = p - buf;
+        }
+        u->field_data[UF_HOST].len++;
+        break;
+
+      case s_http_host_v6:
+        if (s != s_http_host_v6) {
+          u->field_data[UF_HOST].off = p - buf;
+        }
+        u->field_data[UF_HOST].len++;
+        break;
+
+      case s_http_host_port:
+        if (s != s_http_host_port) {
+          u->field_data[UF_PORT].off = p - buf;
+          u->field_data[UF_PORT].len = 0;
+          u->field_set |= (1 << UF_PORT);
+        }
+        u->field_data[UF_PORT].len++;
+        break;
+
+      case s_http_userinfo:
+        if (s != s_http_userinfo) {
+          u->field_data[UF_USERINFO].off = p - buf ;
+          u->field_data[UF_USERINFO].len = 0;
+          u->field_set |= (1 << UF_USERINFO);
+        }
+        u->field_data[UF_USERINFO].len++;
+        break;
+
+      default:
+        break;
+    }
+    s = new_s;
+  }
+
+  /* Make sure we don't end somewhere unexpected */
+  switch (s) {
+    case s_http_host_start:
+    case s_http_host_v6_start:
+    case s_http_host_v6:
+    case s_http_host_port_start:
+    case s_http_userinfo:
+    case s_http_userinfo_start:
+      return 1;
+    default:
+      break;
+  }
+
+  return 0;
+}
+
+int
+http_parser_parse_url(const char *buf, size_t buflen, int is_connect,
+                      struct http_parser_url *u)
+{
+  enum state s;
+  const char *p;
+  enum http_parser_url_fields uf, old_uf;
+  int found_at = 0;
+
+  u->port = u->field_set = 0;
+  s = is_connect ? s_req_server_start : s_req_spaces_before_url;
+  uf = old_uf = UF_MAX;
+
+  for (p = buf; p < buf + buflen; p++) {
+    s = parse_url_char(s, *p);
+
+    /* Figure out the next field that we're operating on */
+    switch (s) {
+      case s_dead:
+        return 1;
+
+      /* Skip delimeters */
+      case s_req_schema_slash:
+      case s_req_schema_slash_slash:
+      case s_req_server_start:
+      case s_req_query_string_start:
+      case s_req_fragment_start:
+        continue;
+
+      case s_req_schema:
+        uf = UF_SCHEMA;
+        break;
+
+      case s_req_server_with_at:
+        found_at = 1;
+
+      /* FALLTROUGH */
+      case s_req_server:
+        uf = UF_HOST;
+        break;
+
+      case s_req_path:
+        uf = UF_PATH;
+        break;
+
+      case s_req_query_string:
+        uf = UF_QUERY;
+        break;
+
+      case s_req_fragment:
+        uf = UF_FRAGMENT;
+        break;
+
+      default:
+        assert(!"Unexpected state");
+        return 1;
+    }
+
+    /* Nothing's changed; soldier on */
+    if (uf == old_uf) {
+      u->field_data[uf].len++;
+      continue;
+    }
+
+    u->field_data[uf].off = p - buf;
+    u->field_data[uf].len = 1;
+
+    u->field_set |= (1 << uf);
+    old_uf = uf;
+  }
+
+  /* host must be present if there is a schema */
+  /* parsing http:///toto will fail */
+  if ((u->field_set & ((1 << UF_SCHEMA) | (1 << UF_HOST))) != 0) {
+    if (http_parse_host(buf, u, found_at) != 0) {
+      return 1;
+    }
+  }
+
+  /* CONNECT requests can only contain "hostname:port" */
+  if (is_connect && u->field_set != ((1 << UF_HOST)|(1 << UF_PORT))) {
+    return 1;
+  }
+
+  if (u->field_set & (1 << UF_PORT)) {
+    /* Don't bother with endp; we've already validated the string */
+    unsigned long v = strtoul(buf + u->field_data[UF_PORT].off, NULL, 10);
+
+    /* Ports have a max value of 2^16 */
+    if (v > 0xffff) {
+      return 1;
+    }
+
+    u->port = (uint16_t) v;
+  }
+
+  return 0;
+}
+
+void
+http_parser_pause(http_parser *parser, int paused) {
+  /* Users should only be pausing/unpausing a parser that is not in an error
+   * state. In non-debug builds, there's not much that we can do about this
+   * other than ignore it.
+   */
+  if (HTTP_PARSER_ERRNO(parser) == HPE_OK ||
+      HTTP_PARSER_ERRNO(parser) == HPE_PAUSED) {
+    SET_ERRNO((paused) ? HPE_PAUSED : HPE_OK);
+  } else {
+    assert(0 && "Attempting to pause parser in error state");
+  }
+}
+
+int
+http_body_is_final(const struct http_parser *parser) {
+    return parser->state == s_message_done;
+}

vendor/libgit2-sys/libgit2/deps/http-parser/http_parser.h

diff --git a/vendor/libgit2-sys/libgit2/deps/http-parser/http_parser.h b/vendor/libgit2-sys/libgit2/deps/http-parser/http_parser.h
new file mode 100644
index 0000000..67e1d95
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/http-parser/http_parser.h
@@ -0,0 +1,305 @@
+/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+#ifndef http_parser_h
+#define http_parser_h
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define HTTP_PARSER_VERSION_MAJOR 2
+#define HTTP_PARSER_VERSION_MINOR 0
+
+#include <sys/types.h>
+#if defined(_WIN32) && !defined(__MINGW32__) && (!defined(_MSC_VER) || _MSC_VER<1600)
+#include <BaseTsd.h>
+typedef __int8 int8_t;
+typedef unsigned __int8 uint8_t;
+typedef __int16 int16_t;
+typedef unsigned __int16 uint16_t;
+typedef __int32 int32_t;
+typedef unsigned __int32 uint32_t;
+typedef __int64 int64_t;
+typedef unsigned __int64 uint64_t;
+typedef SIZE_T size_t;
+typedef SSIZE_T ssize_t;
+#elif defined(__sun) || defined(__sun__)
+#include <sys/inttypes.h>
+#else
+#include <stdint.h>
+#endif
+
+/* Compile with -DHTTP_PARSER_STRICT=0 to make less checks, but run
+ * faster
+ */
+#ifndef HTTP_PARSER_STRICT
+# define HTTP_PARSER_STRICT 1
+#endif
+
+/* Maximium header size allowed */
+#define HTTP_MAX_HEADER_SIZE (80*1024)
+
+
+typedef struct http_parser http_parser;
+typedef struct http_parser_settings http_parser_settings;
+
+
+/* Callbacks should return non-zero to indicate an error. The parser will
+ * then halt execution.
+ *
+ * The one exception is on_headers_complete. In a HTTP_RESPONSE parser
+ * returning '1' from on_headers_complete will tell the parser that it
+ * should not expect a body. This is used when receiving a response to a
+ * HEAD request which may contain 'Content-Length' or 'Transfer-Encoding:
+ * chunked' headers that indicate the presence of a body.
+ *
+ * http_data_cb does not return data chunks. It will be call arbitrarally
+ * many times for each string. E.G. you might get 10 callbacks for "on_url"
+ * each providing just a few characters more data.
+ */
+typedef int (*http_data_cb) (http_parser*, const char *at, size_t length);
+typedef int (*http_cb) (http_parser*);
+
+
+/* Request Methods */
+#define HTTP_METHOD_MAP(XX)         \
+  XX(0,  DELETE,      DELETE)       \
+  XX(1,  GET,         GET)          \
+  XX(2,  HEAD,        HEAD)         \
+  XX(3,  POST,        POST)         \
+  XX(4,  PUT,         PUT)          \
+  /* pathological */                \
+  XX(5,  CONNECT,     CONNECT)      \
+  XX(6,  OPTIONS,     OPTIONS)      \
+  XX(7,  TRACE,       TRACE)        \
+  /* webdav */                      \
+  XX(8,  COPY,        COPY)         \
+  XX(9,  LOCK,        LOCK)         \
+  XX(10, MKCOL,       MKCOL)        \
+  XX(11, MOVE,        MOVE)         \
+  XX(12, PROPFIND,    PROPFIND)     \
+  XX(13, PROPPATCH,   PROPPATCH)    \
+  XX(14, SEARCH,      SEARCH)       \
+  XX(15, UNLOCK,      UNLOCK)       \
+  /* subversion */                  \
+  XX(16, REPORT,      REPORT)       \
+  XX(17, MKACTIVITY,  MKACTIVITY)   \
+  XX(18, CHECKOUT,    CHECKOUT)     \
+  XX(19, MERGE,       MERGE)        \
+  /* upnp */                        \
+  XX(20, MSEARCH,     M-SEARCH)     \
+  XX(21, NOTIFY,      NOTIFY)       \
+  XX(22, SUBSCRIBE,   SUBSCRIBE)    \
+  XX(23, UNSUBSCRIBE, UNSUBSCRIBE)  \
+  /* RFC-5789 */                    \
+  XX(24, PATCH,       PATCH)        \
+  XX(25, PURGE,       PURGE)        \
+
+enum http_method
+  {
+#define XX(num, name, string) HTTP_##name = num,
+  HTTP_METHOD_MAP(XX)
+#undef XX
+  };
+
+
+enum http_parser_type { HTTP_REQUEST, HTTP_RESPONSE, HTTP_BOTH };
+
+
+/* Flag values for http_parser.flags field */
+enum flags
+  { F_CHUNKED               = 1 << 0
+  , F_CONNECTION_KEEP_ALIVE = 1 << 1
+  , F_CONNECTION_CLOSE      = 1 << 2
+  , F_TRAILING              = 1 << 3
+  , F_UPGRADE               = 1 << 4
+  , F_SKIPBODY              = 1 << 5
+  };
+
+
+/* Map for errno-related constants
+ * 
+ * The provided argument should be a macro that takes 2 arguments.
+ */
+#define HTTP_ERRNO_MAP(XX)                                           \
+  /* No error */                                                     \
+  XX(OK, "success")                                                  \
+                                                                     \
+  /* Callback-related errors */                                      \
+  XX(CB_message_begin, "the on_message_begin callback failed")       \
+  XX(CB_url, "the on_url callback failed")                           \
+  XX(CB_header_field, "the on_header_field callback failed")         \
+  XX(CB_header_value, "the on_header_value callback failed")         \
+  XX(CB_headers_complete, "the on_headers_complete callback failed") \
+  XX(CB_body, "the on_body callback failed")                         \
+  XX(CB_message_complete, "the on_message_complete callback failed") \
+                                                                     \
+  /* Parsing-related errors */                                       \
+  XX(INVALID_EOF_STATE, "stream ended at an unexpected time")        \
+  XX(HEADER_OVERFLOW,                                                \
+     "too many header bytes seen; overflow detected")                \
+  XX(CLOSED_CONNECTION,                                              \
+     "data received after completed connection: close message")      \
+  XX(INVALID_VERSION, "invalid HTTP version")                        \
+  XX(INVALID_STATUS, "invalid HTTP status code")                     \
+  XX(INVALID_METHOD, "invalid HTTP method")                          \
+  XX(INVALID_URL, "invalid URL")                                     \
+  XX(INVALID_HOST, "invalid host")                                   \
+  XX(INVALID_PORT, "invalid port")                                   \
+  XX(INVALID_PATH, "invalid path")                                   \
+  XX(INVALID_QUERY_STRING, "invalid query string")                   \
+  XX(INVALID_FRAGMENT, "invalid fragment")                           \
+  XX(LF_EXPECTED, "LF character expected")                           \
+  XX(INVALID_HEADER_TOKEN, "invalid character in header")            \
+  XX(INVALID_CONTENT_LENGTH,                                         \
+     "invalid character in content-length header")                   \
+  XX(INVALID_CHUNK_SIZE,                                             \
+     "invalid character in chunk size header")                       \
+  XX(INVALID_CONSTANT, "invalid constant string")                    \
+  XX(INVALID_INTERNAL_STATE, "encountered unexpected internal state")\
+  XX(STRICT, "strict mode assertion failed")                         \
+  XX(PAUSED, "parser is paused")                                     \
+  XX(UNKNOWN, "an unknown error occurred")
+
+
+/* Define HPE_* values for each errno value above */
+#define HTTP_ERRNO_GEN(n, s) HPE_##n,
+enum http_errno {
+  HTTP_ERRNO_MAP(HTTP_ERRNO_GEN)
+};
+#undef HTTP_ERRNO_GEN
+
+
+/* Get an http_errno value from an http_parser */
+#define HTTP_PARSER_ERRNO(p)            ((enum http_errno) (p)->http_errno)
+
+
+struct http_parser {
+  /** PRIVATE **/
+  unsigned char type : 2;     /* enum http_parser_type */
+  unsigned char flags : 6;    /* F_* values from 'flags' enum; semi-public */
+  unsigned char state;        /* enum state from http_parser.c */
+  unsigned char header_state; /* enum header_state from http_parser.c */
+  unsigned char index;        /* index into current matcher */
+
+  uint32_t nread;          /* # bytes read in various scenarios */
+  uint64_t content_length; /* # bytes in body (0 if no Content-Length header) */
+
+  /** READ-ONLY **/
+  unsigned short http_major;
+  unsigned short http_minor;
+  unsigned short status_code; /* responses only */
+  unsigned char method;       /* requests only */
+  unsigned char http_errno : 7;
+
+  /* 1 = Upgrade header was present and the parser has exited because of that.
+   * 0 = No upgrade header present.
+   * Should be checked when http_parser_execute() returns in addition to
+   * error checking.
+   */
+  unsigned char upgrade : 1;
+
+  /** PUBLIC **/
+  void *data; /* A pointer to get hook to the "connection" or "socket" object */
+};
+
+
+struct http_parser_settings {
+  http_cb      on_message_begin;
+  http_data_cb on_url;
+  http_data_cb on_header_field;
+  http_data_cb on_header_value;
+  http_cb      on_headers_complete;
+  http_data_cb on_body;
+  http_cb      on_message_complete;
+};
+
+
+enum http_parser_url_fields
+  { UF_SCHEMA           = 0
+  , UF_HOST             = 1
+  , UF_PORT             = 2
+  , UF_PATH             = 3
+  , UF_QUERY            = 4
+  , UF_FRAGMENT         = 5
+  , UF_USERINFO         = 6
+  , UF_MAX              = 7
+  };
+
+
+/* Result structure for http_parser_parse_url().
+ *
+ * Callers should index into field_data[] with UF_* values iff field_set
+ * has the relevant (1 << UF_*) bit set. As a courtesy to clients (and
+ * because we probably have padding left over), we convert any port to
+ * a uint16_t.
+ */
+struct http_parser_url {
+  uint16_t field_set;           /* Bitmask of (1 << UF_*) values */
+  uint16_t port;                /* Converted UF_PORT string */
+
+  struct {
+    uint16_t off;               /* Offset into buffer in which field starts */
+    uint16_t len;               /* Length of run in buffer */
+  } field_data[UF_MAX];
+};
+
+
+void http_parser_init(http_parser *parser, enum http_parser_type type);
+
+
+size_t http_parser_execute(http_parser *parser,
+                           const http_parser_settings *settings,
+                           const char *data,
+                           size_t len);
+
+
+/* If http_should_keep_alive() in the on_headers_complete or
+ * on_message_complete callback returns 0, then this should be
+ * the last message on the connection.
+ * If you are the server, respond with the "Connection: close" header.
+ * If you are the client, close the connection.
+ */
+int http_should_keep_alive(const http_parser *parser);
+
+/* Returns a string version of the HTTP method. */
+const char *http_method_str(enum http_method m);
+
+/* Return a string name of the given error */
+const char *http_errno_name(enum http_errno err);
+
+/* Return a string description of the given error */
+const char *http_errno_description(enum http_errno err);
+
+/* Parse a URL; return nonzero on failure */
+int http_parser_parse_url(const char *buf, size_t buflen,
+                          int is_connect,
+                          struct http_parser_url *u);
+
+/* Pause or un-pause the parser; a nonzero value pauses */
+void http_parser_pause(http_parser *parser, int paused);
+
+/* Checks if this is the final chunk of the body. */
+int http_body_is_final(const http_parser *parser);
+
+#ifdef __cplusplus
+}
+#endif
+#endif

vendor/libgit2-sys/libgit2/deps/regex/CMakeLists.txt

diff --git a/vendor/libgit2-sys/libgit2/deps/regex/CMakeLists.txt b/vendor/libgit2-sys/libgit2/deps/regex/CMakeLists.txt
new file mode 100644
index 0000000..141b54c
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/regex/CMakeLists.txt
@@ -0,0 +1,2 @@
+INCLUDE_DIRECTORIES(".")
+ADD_LIBRARY(regex OBJECT "regex.c" "regex.h")

vendor/libgit2-sys/libgit2/deps/regex/config.h

diff --git a/vendor/libgit2-sys/libgit2/deps/regex/config.h b/vendor/libgit2-sys/libgit2/deps/regex/config.h
new file mode 100644
index 0000000..9537069
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/regex/config.h
@@ -0,0 +1,7 @@
+#ifndef _REGEX_CONFIG_H_
+#define _REGEX_CONFIG_H_
+
+# define GAWK
+# define NO_MBSUPPORT
+
+#endif

vendor/libgit2-sys/libgit2/deps/regex/regcomp.c

diff --git a/vendor/libgit2-sys/libgit2/deps/regex/regcomp.c b/vendor/libgit2-sys/libgit2/deps/regex/regcomp.c
new file mode 100644
index 0000000..43bffbc
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/regex/regcomp.c
@@ -0,0 +1,3857 @@
+/* Extended regular expression matching and search library.
+   Copyright (C) 2002-2007,2009,2010 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301 USA.  */
+
+static reg_errcode_t re_compile_internal (regex_t *preg, const char * pattern,
+					  size_t length, reg_syntax_t syntax);
+static void re_compile_fastmap_iter (regex_t *bufp,
+				     const re_dfastate_t *init_state,
+				     char *fastmap);
+static reg_errcode_t init_dfa (re_dfa_t *dfa, size_t pat_len);
+#ifdef RE_ENABLE_I18N
+static void free_charset (re_charset_t *cset);
+#endif /* RE_ENABLE_I18N */
+static void free_workarea_compile (regex_t *preg);
+static reg_errcode_t create_initial_state (re_dfa_t *dfa);
+#ifdef RE_ENABLE_I18N
+static void optimize_utf8 (re_dfa_t *dfa);
+#endif
+static reg_errcode_t analyze (regex_t *preg);
+static reg_errcode_t preorder (bin_tree_t *root,
+			       reg_errcode_t (fn (void *, bin_tree_t *)),
+			       void *extra);
+static reg_errcode_t postorder (bin_tree_t *root,
+				reg_errcode_t (fn (void *, bin_tree_t *)),
+				void *extra);
+static reg_errcode_t optimize_subexps (void *extra, bin_tree_t *node);
+static reg_errcode_t lower_subexps (void *extra, bin_tree_t *node);
+static bin_tree_t *lower_subexp (reg_errcode_t *err, regex_t *preg,
+				 bin_tree_t *node);
+static reg_errcode_t calc_first (void *extra, bin_tree_t *node);
+static reg_errcode_t calc_next (void *extra, bin_tree_t *node);
+static reg_errcode_t link_nfa_nodes (void *extra, bin_tree_t *node);
+static int duplicate_node (re_dfa_t *dfa, int org_idx, unsigned int constraint);
+static int search_duplicated_node (const re_dfa_t *dfa, int org_node,
+				   unsigned int constraint);
+static reg_errcode_t calc_eclosure (re_dfa_t *dfa);
+static reg_errcode_t calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa,
+					 int node, int root);
+static reg_errcode_t calc_inveclosure (re_dfa_t *dfa);
+static int fetch_number (re_string_t *input, re_token_t *token,
+			 reg_syntax_t syntax);
+static int peek_token (re_token_t *token, re_string_t *input,
+			reg_syntax_t syntax) internal_function;
+static bin_tree_t *parse (re_string_t *regexp, regex_t *preg,
+			  reg_syntax_t syntax, reg_errcode_t *err);
+static bin_tree_t *parse_reg_exp (re_string_t *regexp, regex_t *preg,
+				  re_token_t *token, reg_syntax_t syntax,
+				  int nest, reg_errcode_t *err);
+static bin_tree_t *parse_branch (re_string_t *regexp, regex_t *preg,
+				 re_token_t *token, reg_syntax_t syntax,
+				 int nest, reg_errcode_t *err);
+static bin_tree_t *parse_expression (re_string_t *regexp, regex_t *preg,
+				     re_token_t *token, reg_syntax_t syntax,
+				     int nest, reg_errcode_t *err);
+static bin_tree_t *parse_sub_exp (re_string_t *regexp, regex_t *preg,
+				  re_token_t *token, reg_syntax_t syntax,
+				  int nest, reg_errcode_t *err);
+static bin_tree_t *parse_dup_op (bin_tree_t *dup_elem, re_string_t *regexp,
+				 re_dfa_t *dfa, re_token_t *token,
+				 reg_syntax_t syntax, reg_errcode_t *err);
+static bin_tree_t *parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa,
+				      re_token_t *token, reg_syntax_t syntax,
+				      reg_errcode_t *err);
+static reg_errcode_t parse_bracket_element (bracket_elem_t *elem,
+					    re_string_t *regexp,
+					    re_token_t *token, int token_len,
+					    re_dfa_t *dfa,
+					    reg_syntax_t syntax,
+					    int accept_hyphen);
+static reg_errcode_t parse_bracket_symbol (bracket_elem_t *elem,
+					  re_string_t *regexp,
+					  re_token_t *token);
+#ifdef RE_ENABLE_I18N
+static reg_errcode_t build_equiv_class (bitset_t sbcset,
+					re_charset_t *mbcset,
+					int *equiv_class_alloc,
+					const unsigned char *name);
+static reg_errcode_t build_charclass (RE_TRANSLATE_TYPE trans,
+				      bitset_t sbcset,
+				      re_charset_t *mbcset,
+				      int *char_class_alloc,
+				      const char *class_name,
+				      reg_syntax_t syntax);
+#else  /* not RE_ENABLE_I18N */
+static reg_errcode_t build_equiv_class (bitset_t sbcset,
+					const unsigned char *name);
+static reg_errcode_t build_charclass (RE_TRANSLATE_TYPE trans,
+				      bitset_t sbcset,
+				      const char *class_name,
+				      reg_syntax_t syntax);
+#endif /* not RE_ENABLE_I18N */
+static bin_tree_t *build_charclass_op (re_dfa_t *dfa,
+				       RE_TRANSLATE_TYPE trans,
+				       const char *class_name,
+				       const char *extra,
+				       int non_match, reg_errcode_t *err);
+static bin_tree_t *create_tree (re_dfa_t *dfa,
+				bin_tree_t *left, bin_tree_t *right,
+				re_token_type_t type);
+static bin_tree_t *create_token_tree (re_dfa_t *dfa,
+				      bin_tree_t *left, bin_tree_t *right,
+				      const re_token_t *token);
+static bin_tree_t *duplicate_tree (const bin_tree_t *src, re_dfa_t *dfa);
+static void free_token (re_token_t *node);
+static reg_errcode_t free_tree (void *extra, bin_tree_t *node);
+static reg_errcode_t mark_opt_subexp (void *extra, bin_tree_t *node);
+
+/* This table gives an error message for each of the error codes listed
+   in regex.h.  Obviously the order here has to be same as there.
+   POSIX doesn't require that we do anything for REG_NOERROR,
+   but why not be nice?  */
+
+const char __re_error_msgid[] attribute_hidden =
+  {
+#define REG_NOERROR_IDX	0
+    gettext_noop ("Success")	/* REG_NOERROR */
+    "\0"
+#define REG_NOMATCH_IDX (REG_NOERROR_IDX + sizeof "Success")
+    gettext_noop ("No match")	/* REG_NOMATCH */
+    "\0"
+#define REG_BADPAT_IDX	(REG_NOMATCH_IDX + sizeof "No match")
+    gettext_noop ("Invalid regular expression") /* REG_BADPAT */
+    "\0"
+#define REG_ECOLLATE_IDX (REG_BADPAT_IDX + sizeof "Invalid regular expression")
+    gettext_noop ("Invalid collation character") /* REG_ECOLLATE */
+    "\0"
+#define REG_ECTYPE_IDX	(REG_ECOLLATE_IDX + sizeof "Invalid collation character")
+    gettext_noop ("Invalid character class name") /* REG_ECTYPE */
+    "\0"
+#define REG_EESCAPE_IDX	(REG_ECTYPE_IDX + sizeof "Invalid character class name")
+    gettext_noop ("Trailing backslash") /* REG_EESCAPE */
+    "\0"
+#define REG_ESUBREG_IDX	(REG_EESCAPE_IDX + sizeof "Trailing backslash")
+    gettext_noop ("Invalid back reference") /* REG_ESUBREG */
+    "\0"
+#define REG_EBRACK_IDX	(REG_ESUBREG_IDX + sizeof "Invalid back reference")
+    gettext_noop ("Unmatched [ or [^")	/* REG_EBRACK */
+    "\0"
+#define REG_EPAREN_IDX	(REG_EBRACK_IDX + sizeof "Unmatched [ or [^")
+    gettext_noop ("Unmatched ( or \\(") /* REG_EPAREN */
+    "\0"
+#define REG_EBRACE_IDX	(REG_EPAREN_IDX + sizeof "Unmatched ( or \\(")
+    gettext_noop ("Unmatched \\{") /* REG_EBRACE */
+    "\0"
+#define REG_BADBR_IDX	(REG_EBRACE_IDX + sizeof "Unmatched \\{")
+    gettext_noop ("Invalid content of \\{\\}") /* REG_BADBR */
+    "\0"
+#define REG_ERANGE_IDX	(REG_BADBR_IDX + sizeof "Invalid content of \\{\\}")
+    gettext_noop ("Invalid range end")	/* REG_ERANGE */
+    "\0"
+#define REG_ESPACE_IDX	(REG_ERANGE_IDX + sizeof "Invalid range end")
+    gettext_noop ("Memory exhausted") /* REG_ESPACE */
+    "\0"
+#define REG_BADRPT_IDX	(REG_ESPACE_IDX + sizeof "Memory exhausted")
+    gettext_noop ("Invalid preceding regular expression") /* REG_BADRPT */
+    "\0"
+#define REG_EEND_IDX	(REG_BADRPT_IDX + sizeof "Invalid preceding regular expression")
+    gettext_noop ("Premature end of regular expression") /* REG_EEND */
+    "\0"
+#define REG_ESIZE_IDX	(REG_EEND_IDX + sizeof "Premature end of regular expression")
+    gettext_noop ("Regular expression too big") /* REG_ESIZE */
+    "\0"
+#define REG_ERPAREN_IDX	(REG_ESIZE_IDX + sizeof "Regular expression too big")
+    gettext_noop ("Unmatched ) or \\)") /* REG_ERPAREN */
+  };
+
+const size_t __re_error_msgid_idx[] attribute_hidden =
+  {
+    REG_NOERROR_IDX,
+    REG_NOMATCH_IDX,
+    REG_BADPAT_IDX,
+    REG_ECOLLATE_IDX,
+    REG_ECTYPE_IDX,
+    REG_EESCAPE_IDX,
+    REG_ESUBREG_IDX,
+    REG_EBRACK_IDX,
+    REG_EPAREN_IDX,
+    REG_EBRACE_IDX,
+    REG_BADBR_IDX,
+    REG_ERANGE_IDX,
+    REG_ESPACE_IDX,
+    REG_BADRPT_IDX,
+    REG_EEND_IDX,
+    REG_ESIZE_IDX,
+    REG_ERPAREN_IDX
+  };
+
+/* Entry points for GNU code.  */
+
+
+#ifdef ZOS_USS
+
+/* For ZOS USS we must define btowc */
+
+wchar_t 
+btowc (int c)
+{
+   wchar_t wtmp[2];
+   char tmp[2];
+
+   tmp[0] = c;
+   tmp[1] = 0;
+
+   mbtowc (wtmp, tmp, 1);
+   return wtmp[0];
+}
+#endif
+
+/* re_compile_pattern is the GNU regular expression compiler: it
+   compiles PATTERN (of length LENGTH) and puts the result in BUFP.
+   Returns 0 if the pattern was valid, otherwise an error string.
+
+   Assumes the `allocated' (and perhaps `buffer') and `translate' fields
+   are set in BUFP on entry.  */
+
+const char *
+re_compile_pattern (const char *pattern,
+		    size_t length,
+		    struct re_pattern_buffer *bufp)
+{
+  reg_errcode_t ret;
+
+  /* And GNU code determines whether or not to get register information
+     by passing null for the REGS argument to re_match, etc., not by
+     setting no_sub, unless RE_NO_SUB is set.  */
+  bufp->no_sub = !!(re_syntax_options & RE_NO_SUB);
+
+  /* Match anchors at newline.  */
+  bufp->newline_anchor = 1;
+
+  ret = re_compile_internal (bufp, pattern, length, re_syntax_options);
+
+  if (!ret)
+    return NULL;
+  return gettext (__re_error_msgid + __re_error_msgid_idx[(int) ret]);
+}
+#ifdef _LIBC
+weak_alias (__re_compile_pattern, re_compile_pattern)
+#endif
+
+/* Set by `re_set_syntax' to the current regexp syntax to recognize.  Can
+   also be assigned to arbitrarily: each pattern buffer stores its own
+   syntax, so it can be changed between regex compilations.  */
+/* This has no initializer because initialized variables in Emacs
+   become read-only after dumping.  */
+reg_syntax_t re_syntax_options;
+
+
+/* Specify the precise syntax of regexps for compilation.  This provides
+   for compatibility for various utilities which historically have
+   different, incompatible syntaxes.
+
+   The argument SYNTAX is a bit mask comprised of the various bits
+   defined in regex.h.  We return the old syntax.  */
+
+reg_syntax_t
+re_set_syntax (reg_syntax_t syntax)
+{
+  reg_syntax_t ret = re_syntax_options;
+
+  re_syntax_options = syntax;
+  return ret;
+}
+#ifdef _LIBC
+weak_alias (__re_set_syntax, re_set_syntax)
+#endif
+
+int
+re_compile_fastmap (struct re_pattern_buffer *bufp)
+{
+  re_dfa_t *dfa = (re_dfa_t *) bufp->buffer;
+  char *fastmap = bufp->fastmap;
+
+  memset (fastmap, '\0', sizeof (char) * SBC_MAX);
+  re_compile_fastmap_iter (bufp, dfa->init_state, fastmap);
+  if (dfa->init_state != dfa->init_state_word)
+    re_compile_fastmap_iter (bufp, dfa->init_state_word, fastmap);
+  if (dfa->init_state != dfa->init_state_nl)
+    re_compile_fastmap_iter (bufp, dfa->init_state_nl, fastmap);
+  if (dfa->init_state != dfa->init_state_begbuf)
+    re_compile_fastmap_iter (bufp, dfa->init_state_begbuf, fastmap);
+  bufp->fastmap_accurate = 1;
+  return 0;
+}
+#ifdef _LIBC
+weak_alias (__re_compile_fastmap, re_compile_fastmap)
+#endif
+
+static inline void
+__attribute ((always_inline))
+re_set_fastmap (char *fastmap, int icase, int ch)
+{
+  fastmap[ch] = 1;
+  if (icase)
+    fastmap[tolower (ch)] = 1;
+}
+
+/* Helper function for re_compile_fastmap.
+   Compile fastmap for the initial_state INIT_STATE.  */
+
+static void
+re_compile_fastmap_iter (regex_t *bufp, const re_dfastate_t *init_state,
+			 char *fastmap)
+{
+  volatile re_dfa_t *dfa = (re_dfa_t *) bufp->buffer;
+  int node_cnt;
+  int icase = (dfa->mb_cur_max == 1 && (bufp->syntax & RE_ICASE));
+  for (node_cnt = 0; node_cnt < init_state->nodes.nelem; ++node_cnt)
+    {
+      int node = init_state->nodes.elems[node_cnt];
+      re_token_type_t type = dfa->nodes[node].type;
+
+      if (type == CHARACTER)
+	{
+	  re_set_fastmap (fastmap, icase, dfa->nodes[node].opr.c);
+#ifdef RE_ENABLE_I18N
+	  if ((bufp->syntax & RE_ICASE) && dfa->mb_cur_max > 1)
+	    {
+	      unsigned char *buf = re_malloc (unsigned char, dfa->mb_cur_max), *p;
+	      wchar_t wc;
+	      mbstate_t state;
+
+	      p = buf;
+	      *p++ = dfa->nodes[node].opr.c;
+	      while (++node < dfa->nodes_len
+		     &&	dfa->nodes[node].type == CHARACTER
+		     && dfa->nodes[node].mb_partial)
+		*p++ = dfa->nodes[node].opr.c;
+	      memset (&state, '\0', sizeof (state));
+	      if (__mbrtowc (&wc, (const char *) buf, p - buf,
+			     &state) == p - buf
+		  && (__wcrtomb ((char *) buf, towlower (wc), &state)
+		      != (size_t) -1))
+		re_set_fastmap (fastmap, 0, buf[0]);
+	      re_free (buf);
+	    }
+#endif
+	}
+      else if (type == SIMPLE_BRACKET)
+	{
+	  int i, ch;
+	  for (i = 0, ch = 0; i < BITSET_WORDS; ++i)
+	    {
+	      int j;
+	      bitset_word_t w = dfa->nodes[node].opr.sbcset[i];
+	      for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch)
+		if (w & ((bitset_word_t) 1 << j))
+		  re_set_fastmap (fastmap, icase, ch);
+	    }
+	}
+#ifdef RE_ENABLE_I18N
+      else if (type == COMPLEX_BRACKET)
+	{
+	  re_charset_t *cset = dfa->nodes[node].opr.mbcset;
+	  int i;
+
+# ifdef _LIBC
+	  /* See if we have to try all bytes which start multiple collation
+	     elements.
+	     e.g. In da_DK, we want to catch 'a' since "aa" is a valid
+		  collation element, and don't catch 'b' since 'b' is
+		  the only collation element which starts from 'b' (and
+		  it is caught by SIMPLE_BRACKET).  */
+	      if (_NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES) != 0
+		  && (cset->ncoll_syms || cset->nranges))
+		{
+		  const int32_t *table = (const int32_t *)
+		    _NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEMB);
+		  for (i = 0; i < SBC_MAX; ++i)
+		    if (table[i] < 0)
+		      re_set_fastmap (fastmap, icase, i);
+		}
+# endif /* _LIBC */
+
+	  /* See if we have to start the match at all multibyte characters,
+	     i.e. where we would not find an invalid sequence.  This only
+	     applies to multibyte character sets; for single byte character
+	     sets, the SIMPLE_BRACKET again suffices.  */
+	  if (dfa->mb_cur_max > 1
+	      && (cset->nchar_classes || cset->non_match || cset->nranges
+# ifdef _LIBC
+		  || cset->nequiv_classes
+# endif /* _LIBC */
+		 ))
+	    {
+	      unsigned char c = 0;
+	      do
+		{
+		  mbstate_t mbs;
+		  memset (&mbs, 0, sizeof (mbs));
+		  if (__mbrtowc (NULL, (char *) &c, 1, &mbs) == (size_t) -2)
+		    re_set_fastmap (fastmap, false, (int) c);
+		}
+	      while (++c != 0);
+	    }
+
+	  else
+	    {
+	      /* ... Else catch all bytes which can start the mbchars.  */
+	      for (i = 0; i < cset->nmbchars; ++i)
+		{
+		  char buf[256];
+		  mbstate_t state;
+		  memset (&state, '\0', sizeof (state));
+		  if (__wcrtomb (buf, cset->mbchars[i], &state) != (size_t) -1)
+		    re_set_fastmap (fastmap, icase, *(unsigned char *) buf);
+		  if ((bufp->syntax & RE_ICASE) && dfa->mb_cur_max > 1)
+		    {
+		      if (__wcrtomb (buf, towlower (cset->mbchars[i]), &state)
+			  != (size_t) -1)
+			re_set_fastmap (fastmap, false, *(unsigned char *) buf);
+		    }
+		}
+	    }
+	}
+#endif /* RE_ENABLE_I18N */
+      else if (type == OP_PERIOD
+#ifdef RE_ENABLE_I18N
+	       || type == OP_UTF8_PERIOD
+#endif /* RE_ENABLE_I18N */
+	       || type == END_OF_RE)
+	{
+	  memset (fastmap, '\1', sizeof (char) * SBC_MAX);
+	  if (type == END_OF_RE)
+	    bufp->can_be_null = 1;
+	  return;
+	}
+    }
+}
+
+/* Entry point for POSIX code.  */
+/* regcomp takes a regular expression as a string and compiles it.
+
+   PREG is a regex_t *.  We do not expect any fields to be initialized,
+   since POSIX says we shouldn't.  Thus, we set
+
+     `buffer' to the compiled pattern;
+     `used' to the length of the compiled pattern;
+     `syntax' to RE_SYNTAX_POSIX_EXTENDED if the
+       REG_EXTENDED bit in CFLAGS is set; otherwise, to
+       RE_SYNTAX_POSIX_BASIC;
+     `newline_anchor' to REG_NEWLINE being set in CFLAGS;
+     `fastmap' to an allocated space for the fastmap;
+     `fastmap_accurate' to zero;
+     `re_nsub' to the number of subexpressions in PATTERN.
+
+   PATTERN is the address of the pattern string.
+
+   CFLAGS is a series of bits which affect compilation.
+
+     If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
+     use POSIX basic syntax.
+
+     If REG_NEWLINE is set, then . and [^...] don't match newline.
+     Also, regexec will try a match beginning after every newline.
+
+     If REG_ICASE is set, then we considers upper- and lowercase
+     versions of letters to be equivalent when matching.
+
+     If REG_NOSUB is set, then when PREG is passed to regexec, that
+     routine will report only success or failure, and nothing about the
+     registers.
+
+   It returns 0 if it succeeds, nonzero if it doesn't.  (See regex.h for
+   the return codes and their meanings.)  */
+
+int
+regcomp (regex_t *__restrict preg,
+	 const char *__restrict pattern,
+	 int cflags)
+{
+  reg_errcode_t ret;
+  reg_syntax_t syntax = ((cflags & REG_EXTENDED) ? RE_SYNTAX_POSIX_EXTENDED
+			 : RE_SYNTAX_POSIX_BASIC);
+
+  preg->buffer = NULL;
+  preg->allocated = 0;
+  preg->used = 0;
+
+  /* Try to allocate space for the fastmap.  */
+  preg->fastmap = re_malloc (char, SBC_MAX);
+  if (BE (preg->fastmap == NULL, 0))
+    return REG_ESPACE;
+
+  syntax |= (cflags & REG_ICASE) ? RE_ICASE : 0;
+
+  /* If REG_NEWLINE is set, newlines are treated differently.  */
+  if (cflags & REG_NEWLINE)
+    { /* REG_NEWLINE implies neither . nor [^...] match newline.  */
+      syntax &= ~RE_DOT_NEWLINE;
+      syntax |= RE_HAT_LISTS_NOT_NEWLINE;
+      /* It also changes the matching behavior.  */
+      preg->newline_anchor = 1;
+    }
+  else
+    preg->newline_anchor = 0;
+  preg->no_sub = !!(cflags & REG_NOSUB);
+  preg->translate = NULL;
+
+  ret = re_compile_internal (preg, pattern, strlen (pattern), syntax);
+
+  /* POSIX doesn't distinguish between an unmatched open-group and an
+     unmatched close-group: both are REG_EPAREN.  */
+  if (ret == REG_ERPAREN)
+    ret = REG_EPAREN;
+
+  /* We have already checked preg->fastmap != NULL.  */
+  if (BE (ret == REG_NOERROR, 1))
+    /* Compute the fastmap now, since regexec cannot modify the pattern
+       buffer.  This function never fails in this implementation.  */
+    (void) re_compile_fastmap (preg);
+  else
+    {
+      /* Some error occurred while compiling the expression.  */
+      re_free (preg->fastmap);
+      preg->fastmap = NULL;
+    }
+
+  return (int) ret;
+}
+#ifdef _LIBC
+weak_alias (__regcomp, regcomp)
+#endif
+
+/* Returns a message corresponding to an error code, ERRCODE, returned
+   from either regcomp or regexec.   We don't use PREG here.  */
+
+size_t
+regerror(int errcode, UNUSED const regex_t *__restrict preg,
+	 char *__restrict errbuf, size_t errbuf_size)
+{
+  const char *msg;
+  size_t msg_size;
+
+  if (BE (errcode < 0
+	  || errcode >= (int) (sizeof (__re_error_msgid_idx)
+			       / sizeof (__re_error_msgid_idx[0])), 0))
+    /* Only error codes returned by the rest of the code should be passed
+       to this routine.  If we are given anything else, or if other regex
+       code generates an invalid error code, then the program has a bug.
+       Dump core so we can fix it.  */
+    abort ();
+
+  msg = gettext (__re_error_msgid + __re_error_msgid_idx[errcode]);
+
+  msg_size = strlen (msg) + 1; /* Includes the null.  */
+
+  if (BE (errbuf_size != 0, 1))
+    {
+      if (BE (msg_size > errbuf_size, 0))
+	{
+	  memcpy (errbuf, msg, errbuf_size - 1);
+	  errbuf[errbuf_size - 1] = 0;
+	}
+      else
+	memcpy (errbuf, msg, msg_size);
+    }
+
+  return msg_size;
+}
+#ifdef _LIBC
+weak_alias (__regerror, regerror)
+#endif
+
+
+#ifdef RE_ENABLE_I18N
+/* This static array is used for the map to single-byte characters when
+   UTF-8 is used.  Otherwise we would allocate memory just to initialize
+   it the same all the time.  UTF-8 is the preferred encoding so this is
+   a worthwhile optimization.  */
+#if __GNUC__ >= 3
+static const bitset_t utf8_sb_map = {
+  /* Set the first 128 bits.  */
+  [0 ... 0x80 / BITSET_WORD_BITS - 1] = BITSET_WORD_MAX
+};
+#else /* ! (__GNUC__ >= 3) */
+static bitset_t utf8_sb_map;
+#endif /* __GNUC__ >= 3 */
+#endif /* RE_ENABLE_I18N */
+
+
+static void
+free_dfa_content (re_dfa_t *dfa)
+{
+  unsigned int i;
+  int j;
+
+  if (dfa->nodes)
+    for (i = 0; i < dfa->nodes_len; ++i)
+      free_token (dfa->nodes + i);
+  re_free (dfa->nexts);
+  for (i = 0; i < dfa->nodes_len; ++i)
+    {
+      if (dfa->eclosures != NULL)
+	re_node_set_free (dfa->eclosures + i);
+      if (dfa->inveclosures != NULL)
+	re_node_set_free (dfa->inveclosures + i);
+      if (dfa->edests != NULL)
+	re_node_set_free (dfa->edests + i);
+    }
+  re_free (dfa->edests);
+  re_free (dfa->eclosures);
+  re_free (dfa->inveclosures);
+  re_free (dfa->nodes);
+
+  if (dfa->state_table)
+    for (i = 0; i <= dfa->state_hash_mask; ++i)
+      {
+	struct re_state_table_entry *entry = dfa->state_table + i;
+	for (j = 0; j < entry->num; ++j)
+	  {
+	    re_dfastate_t *state = entry->array[j];
+	    free_state (state);
+	  }
+	re_free (entry->array);
+      }
+  re_free (dfa->state_table);
+#ifdef RE_ENABLE_I18N
+  if (dfa->sb_char != utf8_sb_map)
+    re_free (dfa->sb_char);
+#endif
+  re_free (dfa->subexp_map);
+#ifdef DEBUG
+  re_free (dfa->re_str);
+#endif
+
+  re_free (dfa);
+}
+
+
+/* Free dynamically allocated space used by PREG.  */
+
+void
+regfree (regex_t *preg)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  if (BE (dfa != NULL, 1))
+    free_dfa_content (dfa);
+  preg->buffer = NULL;
+  preg->allocated = 0;
+
+  re_free (preg->fastmap);
+  preg->fastmap = NULL;
+
+  re_free (preg->translate);
+  preg->translate = NULL;
+}
+#ifdef _LIBC
+weak_alias (__regfree, regfree)
+#endif
+
+/* Entry points compatible with 4.2 BSD regex library.  We don't define
+   them unless specifically requested.  */
+
+#if defined _REGEX_RE_COMP || defined _LIBC
+
+/* BSD has one and only one pattern buffer.  */
+static struct re_pattern_buffer re_comp_buf;
+
+char *
+# ifdef _LIBC
+/* Make these definitions weak in libc, so POSIX programs can redefine
+   these names if they don't use our functions, and still use
+   regcomp/regexec above without link errors.  */
+weak_function
+# endif
+re_comp (s)
+     const char *s;
+{
+  reg_errcode_t ret;
+  char *fastmap;
+
+  if (!s)
+    {
+      if (!re_comp_buf.buffer)
+	return gettext ("No previous regular expression");
+      return 0;
+    }
+
+  if (re_comp_buf.buffer)
+    {
+      fastmap = re_comp_buf.fastmap;
+      re_comp_buf.fastmap = NULL;
+      __regfree (&re_comp_buf);
+      memset (&re_comp_buf, '\0', sizeof (re_comp_buf));
+      re_comp_buf.fastmap = fastmap;
+    }
+
+  if (re_comp_buf.fastmap == NULL)
+    {
+      re_comp_buf.fastmap = (char *) malloc (SBC_MAX);
+      if (re_comp_buf.fastmap == NULL)
+	return (char *) gettext (__re_error_msgid
+				 + __re_error_msgid_idx[(int) REG_ESPACE]);
+    }
+
+  /* Since `re_exec' always passes NULL for the `regs' argument, we
+     don't need to initialize the pattern buffer fields which affect it.  */
+
+  /* Match anchors at newlines.  */
+  re_comp_buf.newline_anchor = 1;
+
+  ret = re_compile_internal (&re_comp_buf, s, strlen (s), re_syntax_options);
+
+  if (!ret)
+    return NULL;
+
+  /* Yes, we're discarding `const' here if !HAVE_LIBINTL.  */
+  return (char *) gettext (__re_error_msgid + __re_error_msgid_idx[(int) ret]);
+}
+
+#ifdef _LIBC
+libc_freeres_fn (free_mem)
+{
+  __regfree (&re_comp_buf);
+}
+#endif
+
+#endif /* _REGEX_RE_COMP */
+
+/* Internal entry point.
+   Compile the regular expression PATTERN, whose length is LENGTH.
+   SYNTAX indicate regular expression's syntax.  */
+
+static reg_errcode_t
+re_compile_internal (regex_t *preg, const char * pattern, size_t length,
+		     reg_syntax_t syntax)
+{
+  reg_errcode_t err = REG_NOERROR;
+  re_dfa_t *dfa;
+  re_string_t regexp;
+
+  /* Initialize the pattern buffer.  */
+  preg->fastmap_accurate = 0;
+  preg->syntax = syntax;
+  preg->not_bol = preg->not_eol = 0;
+  preg->used = 0;
+  preg->re_nsub = 0;
+  preg->can_be_null = 0;
+  preg->regs_allocated = REGS_UNALLOCATED;
+
+  /* Initialize the dfa.  */
+  dfa = (re_dfa_t *) preg->buffer;
+  if (BE (preg->allocated < sizeof (re_dfa_t), 0))
+    {
+      /* If zero allocated, but buffer is non-null, try to realloc
+	 enough space.  This loses if buffer's address is bogus, but
+	 that is the user's responsibility.  If ->buffer is NULL this
+	 is a simple allocation.  */
+      dfa = re_realloc (preg->buffer, re_dfa_t, 1);
+      if (dfa == NULL)
+	return REG_ESPACE;
+      preg->allocated = sizeof (re_dfa_t);
+      preg->buffer = (unsigned char *) dfa;
+    }
+  preg->used = sizeof (re_dfa_t);
+
+  err = init_dfa (dfa, length);
+  if (BE (err != REG_NOERROR, 0))
+    {
+      free_dfa_content (dfa);
+      preg->buffer = NULL;
+      preg->allocated = 0;
+      return err;
+    }
+#ifdef DEBUG
+  /* Note: length+1 will not overflow since it is checked in init_dfa.  */
+  dfa->re_str = re_malloc (char, length + 1);
+  strncpy (dfa->re_str, pattern, length + 1);
+#endif
+
+  __libc_lock_init (dfa->lock);
+
+  err = re_string_construct (&regexp, pattern, length, preg->translate,
+			     syntax & RE_ICASE, dfa);
+  if (BE (err != REG_NOERROR, 0))
+    {
+    re_compile_internal_free_return:
+      free_workarea_compile (preg);
+      re_string_destruct (&regexp);
+      free_dfa_content (dfa);
+      preg->buffer = NULL;
+      preg->allocated = 0;
+      return err;
+    }
+
+  /* Parse the regular expression, and build a structure tree.  */
+  preg->re_nsub = 0;
+  dfa->str_tree = parse (&regexp, preg, syntax, &err);
+  if (BE (dfa->str_tree == NULL, 0))
+    goto re_compile_internal_free_return;
+
+  /* Analyze the tree and create the nfa.  */
+  err = analyze (preg);
+  if (BE (err != REG_NOERROR, 0))
+    goto re_compile_internal_free_return;
+
+#ifdef RE_ENABLE_I18N
+  /* If possible, do searching in single byte encoding to speed things up.  */
+  if (dfa->is_utf8 && !(syntax & RE_ICASE) && preg->translate == NULL)
+    optimize_utf8 (dfa);
+#endif
+
+  /* Then create the initial state of the dfa.  */
+  err = create_initial_state (dfa);
+
+  /* Release work areas.  */
+  free_workarea_compile (preg);
+  re_string_destruct (&regexp);
+
+  if (BE (err != REG_NOERROR, 0))
+    {
+      free_dfa_content (dfa);
+      preg->buffer = NULL;
+      preg->allocated = 0;
+    }
+
+  return err;
+}
+
+/* Initialize DFA.  We use the length of the regular expression PAT_LEN
+   as the initial length of some arrays.  */
+
+static reg_errcode_t
+init_dfa (re_dfa_t *dfa, size_t pat_len)
+{
+  unsigned int table_size;
+
+  memset (dfa, '\0', sizeof (re_dfa_t));
+
+  /* Force allocation of str_tree_storage the first time.  */
+  dfa->str_tree_storage_idx = BIN_TREE_STORAGE_SIZE;
+
+  /* Avoid overflows.  */
+  if (pat_len == SIZE_MAX)
+    return REG_ESPACE;
+
+  dfa->nodes_alloc = pat_len + 1;
+  dfa->nodes = re_malloc (re_token_t, dfa->nodes_alloc);
+
+  /*  table_size = 2 ^ ceil(log pat_len) */
+  for (table_size = 1; ; table_size <<= 1)
+    if (table_size > pat_len)
+      break;
+
+  dfa->state_table = calloc (sizeof (struct re_state_table_entry), table_size);
+  dfa->state_hash_mask = table_size - 1;
+
+  dfa->mb_cur_max = MB_CUR_MAX;
+#ifdef _LIBC
+  if (dfa->mb_cur_max == 6
+      && strcmp (_NL_CURRENT (LC_CTYPE, _NL_CTYPE_CODESET_NAME), "UTF-8") == 0)
+    dfa->is_utf8 = 1;
+  dfa->map_notascii = (_NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_MAP_TO_NONASCII)
+		       != 0);
+#else
+  dfa->is_utf8 = 1;
+  /* We check exhaustively in the loop below if this charset is a
+     superset of ASCII.  */
+  dfa->map_notascii = 0;
+#endif
+
+#ifdef RE_ENABLE_I18N
+  if (dfa->mb_cur_max > 1)
+    {
+      if (dfa->is_utf8)
+        {
+#if !defined(__GNUC__) || __GNUC__ < 3
+	  static short utf8_sb_map_inited = 0;
+
+	  if (! utf8_sb_map_inited)
+	    {
+		int i;
+
+	  	utf8_sb_map_inited = 0;
+		for (i = 0; i <= 0x80 / BITSET_WORD_BITS - 1; i++)
+		  utf8_sb_map[i] = BITSET_WORD_MAX;
+	    }
+#endif
+	  dfa->sb_char = (re_bitset_ptr_t) utf8_sb_map;
+	}
+      else
+	{
+	  int i, j, ch;
+
+	  dfa->sb_char = (re_bitset_ptr_t) calloc (sizeof (bitset_t), 1);
+	  if (BE (dfa->sb_char == NULL, 0))
+	    return REG_ESPACE;
+
+	  /* Set the bits corresponding to single byte chars.  */
+	  for (i = 0, ch = 0; i < BITSET_WORDS; ++i)
+	    for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch)
+	      {
+		wint_t wch = __btowc (ch);
+		if (wch != WEOF)
+		  dfa->sb_char[i] |= (bitset_word_t) 1 << j;
+# ifndef _LIBC
+		if (isascii (ch) && wch != ch)
+		  dfa->map_notascii = 1;
+# endif
+	      }
+	}
+    }
+#endif
+
+  if (BE (dfa->nodes == NULL || dfa->state_table == NULL, 0))
+    return REG_ESPACE;
+  return REG_NOERROR;
+}
+
+/* Initialize WORD_CHAR table, which indicate which character is
+   "word".  In this case "word" means that it is the word construction
+   character used by some operators like "\<", "\>", etc.  */
+
+static void
+internal_function
+init_word_char (re_dfa_t *dfa)
+{
+  int i, j, ch;
+  dfa->word_ops_used = 1;
+  for (i = 0, ch = 0; i < BITSET_WORDS; ++i)
+    for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch)
+      if (isalnum (ch) || ch == '_')
+	dfa->word_char[i] |= (bitset_word_t) 1 << j;
+}
+
+/* Free the work area which are only used while compiling.  */
+
+static void
+free_workarea_compile (regex_t *preg)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  bin_tree_storage_t *storage, *next;
+  for (storage = dfa->str_tree_storage; storage; storage = next)
+    {
+      next = storage->next;
+      re_free (storage);
+    }
+  dfa->str_tree_storage = NULL;
+  dfa->str_tree_storage_idx = BIN_TREE_STORAGE_SIZE;
+  dfa->str_tree = NULL;
+  re_free (dfa->org_indices);
+  dfa->org_indices = NULL;
+}
+
+/* Create initial states for all contexts.  */
+
+static reg_errcode_t
+create_initial_state (re_dfa_t *dfa)
+{
+  int first, i;
+  reg_errcode_t err;
+  re_node_set init_nodes;
+
+  /* Initial states have the epsilon closure of the node which is
+     the first node of the regular expression.  */
+  first = dfa->str_tree->first->node_idx;
+  dfa->init_node = first;
+  err = re_node_set_init_copy (&init_nodes, dfa->eclosures + first);
+  if (BE (err != REG_NOERROR, 0))
+    return err;
+
+  /* The back-references which are in initial states can epsilon transit,
+     since in this case all of the subexpressions can be null.
+     Then we add epsilon closures of the nodes which are the next nodes of
+     the back-references.  */
+  if (dfa->nbackref > 0)
+    for (i = 0; i < init_nodes.nelem; ++i)
+      {
+	int node_idx = init_nodes.elems[i];
+	re_token_type_t type = dfa->nodes[node_idx].type;
+
+	int clexp_idx;
+	if (type != OP_BACK_REF)
+	  continue;
+	for (clexp_idx = 0; clexp_idx < init_nodes.nelem; ++clexp_idx)
+	  {
+	    re_token_t *clexp_node;
+	    clexp_node = dfa->nodes + init_nodes.elems[clexp_idx];
+	    if (clexp_node->type == OP_CLOSE_SUBEXP
+		&& clexp_node->opr.idx == dfa->nodes[node_idx].opr.idx)
+	      break;
+	  }
+	if (clexp_idx == init_nodes.nelem)
+	  continue;
+
+	if (type == OP_BACK_REF)
+	  {
+	    int dest_idx = dfa->edests[node_idx].elems[0];
+	    if (!re_node_set_contains (&init_nodes, dest_idx))
+	      {
+		reg_errcode_t err = re_node_set_merge (&init_nodes,
+						       dfa->eclosures
+						       + dest_idx);
+		if (err != REG_NOERROR)
+		  return err;
+		i = 0;
+	      }
+	  }
+      }
+
+  /* It must be the first time to invoke acquire_state.  */
+  dfa->init_state = re_acquire_state_context (&err, dfa, &init_nodes, 0);
+  /* We don't check ERR here, since the initial state must not be NULL.  */
+  if (BE (dfa->init_state == NULL, 0))
+    return err;
+  if (dfa->init_state->has_constraint)
+    {
+      dfa->init_state_word = re_acquire_state_context (&err, dfa, &init_nodes,
+						       CONTEXT_WORD);
+      dfa->init_state_nl = re_acquire_state_context (&err, dfa, &init_nodes,
+						     CONTEXT_NEWLINE);
+      dfa->init_state_begbuf = re_acquire_state_context (&err, dfa,
+							 &init_nodes,
+							 CONTEXT_NEWLINE
+							 | CONTEXT_BEGBUF);
+      if (BE (dfa->init_state_word == NULL || dfa->init_state_nl == NULL
+	      || dfa->init_state_begbuf == NULL, 0))
+	return err;
+    }
+  else
+    dfa->init_state_word = dfa->init_state_nl
+      = dfa->init_state_begbuf = dfa->init_state;
+
+  re_node_set_free (&init_nodes);
+  return REG_NOERROR;
+}
+
+#ifdef RE_ENABLE_I18N
+/* If it is possible to do searching in single byte encoding instead of UTF-8
+   to speed things up, set dfa->mb_cur_max to 1, clear is_utf8 and change
+   DFA nodes where needed.  */
+
+static void
+optimize_utf8 (re_dfa_t *dfa)
+{
+  int node, i, mb_chars = 0, has_period = 0;
+
+  for (node = 0; node < dfa->nodes_len; ++node)
+    switch (dfa->nodes[node].type)
+      {
+      case CHARACTER:
+	if (dfa->nodes[node].opr.c >= 0x80)
+	  mb_chars = 1;
+	break;
+      case ANCHOR:
+	switch (dfa->nodes[node].opr.ctx_type)
+	  {
+	  case LINE_FIRST:
+	  case LINE_LAST:
+	  case BUF_FIRST:
+	  case BUF_LAST:
+	    break;
+	  default:
+	    /* Word anchors etc. cannot be handled.  It's okay to test
+	       opr.ctx_type since constraints (for all DFA nodes) are
+	       created by ORing one or more opr.ctx_type values.  */
+	    return;
+	  }
+	break;
+      case OP_PERIOD:
+	has_period = 1;
+	break;
+      case OP_BACK_REF:
+      case OP_ALT:
+      case END_OF_RE:
+      case OP_DUP_ASTERISK:
+      case OP_OPEN_SUBEXP:
+      case OP_CLOSE_SUBEXP:
+	break;
+      case COMPLEX_BRACKET:
+	return;
+      case SIMPLE_BRACKET:
+	/* Just double check.  The non-ASCII range starts at 0x80.  */
+	assert (0x80 % BITSET_WORD_BITS == 0);
+	for (i = 0x80 / BITSET_WORD_BITS; i < BITSET_WORDS; ++i)
+	  if (dfa->nodes[node].opr.sbcset[i])
+	    return;
+	break;
+      default:
+	abort ();
+      }
+
+  if (mb_chars || has_period)
+    for (node = 0; node < dfa->nodes_len; ++node)
+      {
+	if (dfa->nodes[node].type == CHARACTER
+	    && dfa->nodes[node].opr.c >= 0x80)
+	  dfa->nodes[node].mb_partial = 0;
+	else if (dfa->nodes[node].type == OP_PERIOD)
+	  dfa->nodes[node].type = OP_UTF8_PERIOD;
+      }
+
+  /* The search can be in single byte locale.  */
+  dfa->mb_cur_max = 1;
+  dfa->is_utf8 = 0;
+  dfa->has_mb_node = dfa->nbackref > 0 || has_period;
+}
+#endif
+
+/* Analyze the structure tree, and calculate "first", "next", "edest",
+   "eclosure", and "inveclosure".  */
+
+static reg_errcode_t
+analyze (regex_t *preg)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  reg_errcode_t ret;
+
+  /* Allocate arrays.  */
+  dfa->nexts = re_malloc (int, dfa->nodes_alloc);
+  dfa->org_indices = re_malloc (int, dfa->nodes_alloc);
+  dfa->edests = re_malloc (re_node_set, dfa->nodes_alloc);
+  dfa->eclosures = re_malloc (re_node_set, dfa->nodes_alloc);
+  if (BE (dfa->nexts == NULL || dfa->org_indices == NULL || dfa->edests == NULL
+	  || dfa->eclosures == NULL, 0))
+    return REG_ESPACE;
+
+  dfa->subexp_map = re_malloc (int, preg->re_nsub);
+  if (dfa->subexp_map != NULL)
+    {
+      unsigned int i;
+      for (i = 0; i < preg->re_nsub; i++)
+	dfa->subexp_map[i] = i;
+      preorder (dfa->str_tree, optimize_subexps, dfa);
+      for (i = 0; i < preg->re_nsub; i++)
+	if (dfa->subexp_map[i] != (int)i)
+	  break;
+      if (i == preg->re_nsub)
+	{
+	  free (dfa->subexp_map);
+	  dfa->subexp_map = NULL;
+	}
+    }
+
+  ret = postorder (dfa->str_tree, lower_subexps, preg);
+  if (BE (ret != REG_NOERROR, 0))
+    return ret;
+  ret = postorder (dfa->str_tree, calc_first, dfa);
+  if (BE (ret != REG_NOERROR, 0))
+    return ret;
+  preorder (dfa->str_tree, calc_next, dfa);
+  ret = preorder (dfa->str_tree, link_nfa_nodes, dfa);
+  if (BE (ret != REG_NOERROR, 0))
+    return ret;
+  ret = calc_eclosure (dfa);
+  if (BE (ret != REG_NOERROR, 0))
+    return ret;
+
+  /* We only need this during the prune_impossible_nodes pass in regexec.c;
+     skip it if p_i_n will not run, as calc_inveclosure can be quadratic.  */
+  if ((!preg->no_sub && preg->re_nsub > 0 && dfa->has_plural_match)
+      || dfa->nbackref)
+    {
+      dfa->inveclosures = re_malloc (re_node_set, dfa->nodes_len);
+      if (BE (dfa->inveclosures == NULL, 0))
+	return REG_ESPACE;
+      ret = calc_inveclosure (dfa);
+    }
+
+  return ret;
+}
+
+/* Our parse trees are very unbalanced, so we cannot use a stack to
+   implement parse tree visits.  Instead, we use parent pointers and
+   some hairy code in these two functions.  */
+static reg_errcode_t
+postorder (bin_tree_t *root, reg_errcode_t (fn (void *, bin_tree_t *)),
+	   void *extra)
+{
+  bin_tree_t *node, *prev;
+
+  for (node = root; ; )
+    {
+      /* Descend down the tree, preferably to the left (or to the right
+	 if that's the only child).  */
+      while (node->left || node->right)
+	if (node->left)
+	  node = node->left;
+	else
+	  node = node->right;
+
+      do
+	{
+	  reg_errcode_t err = fn (extra, node);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+	  if (node->parent == NULL)
+	    return REG_NOERROR;
+	  prev = node;
+	  node = node->parent;
+	}
+      /* Go up while we have a node that is reached from the right.  */
+      while (node->right == prev || node->right == NULL);
+      node = node->right;
+    }
+}
+
+static reg_errcode_t
+preorder (bin_tree_t *root, reg_errcode_t (fn (void *, bin_tree_t *)),
+	  void *extra)
+{
+  bin_tree_t *node;
+
+  for (node = root; ; )
+    {
+      reg_errcode_t err = fn (extra, node);
+      if (BE (err != REG_NOERROR, 0))
+	return err;
+
+      /* Go to the left node, or up and to the right.  */
+      if (node->left)
+	node = node->left;
+      else
+	{
+	  bin_tree_t *prev = NULL;
+	  while (node->right == prev || node->right == NULL)
+	    {
+	      prev = node;
+	      node = node->parent;
+	      if (!node)
+		return REG_NOERROR;
+	    }
+	  node = node->right;
+	}
+    }
+}
+
+/* Optimization pass: if a SUBEXP is entirely contained, strip it and tell
+   re_search_internal to map the inner one's opr.idx to this one's.  Adjust
+   backreferences as well.  Requires a preorder visit.  */
+static reg_errcode_t
+optimize_subexps (void *extra, bin_tree_t *node)
+{
+  re_dfa_t *dfa = (re_dfa_t *) extra;
+
+  if (node->token.type == OP_BACK_REF && dfa->subexp_map)
+    {
+      int idx = node->token.opr.idx;
+      node->token.opr.idx = dfa->subexp_map[idx];
+      dfa->used_bkref_map |= 1 << node->token.opr.idx;
+    }
+
+  else if (node->token.type == SUBEXP
+	   && node->left && node->left->token.type == SUBEXP)
+    {
+      int other_idx = node->left->token.opr.idx;
+
+      node->left = node->left->left;
+      if (node->left)
+	node->left->parent = node;
+
+      dfa->subexp_map[other_idx] = dfa->subexp_map[node->token.opr.idx];
+      if (other_idx < BITSET_WORD_BITS)
+	  dfa->used_bkref_map &= ~((bitset_word_t) 1 << other_idx);
+    }
+
+  return REG_NOERROR;
+}
+
+/* Lowering pass: Turn each SUBEXP node into the appropriate concatenation
+   of OP_OPEN_SUBEXP, the body of the SUBEXP (if any) and OP_CLOSE_SUBEXP.  */
+static reg_errcode_t
+lower_subexps (void *extra, bin_tree_t *node)
+{
+  regex_t *preg = (regex_t *) extra;
+  reg_errcode_t err = REG_NOERROR;
+
+  if (node->left && node->left->token.type == SUBEXP)
+    {
+      node->left = lower_subexp (&err, preg, node->left);
+      if (node->left)
+	node->left->parent = node;
+    }
+  if (node->right && node->right->token.type == SUBEXP)
+    {
+      node->right = lower_subexp (&err, preg, node->right);
+      if (node->right)
+	node->right->parent = node;
+    }
+
+  return err;
+}
+
+static bin_tree_t *
+lower_subexp (reg_errcode_t *err, regex_t *preg, bin_tree_t *node)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  bin_tree_t *body = node->left;
+  bin_tree_t *op, *cls, *tree1, *tree;
+
+  if (preg->no_sub
+      /* We do not optimize empty subexpressions, because otherwise we may
+	 have bad CONCAT nodes with NULL children.  This is obviously not
+	 very common, so we do not lose much.  An example that triggers
+	 this case is the sed "script" /\(\)/x.  */
+      && node->left != NULL
+      && (node->token.opr.idx >= BITSET_WORD_BITS
+	  || !(dfa->used_bkref_map
+	       & ((bitset_word_t) 1 << node->token.opr.idx))))
+    return node->left;
+
+  /* Convert the SUBEXP node to the concatenation of an
+     OP_OPEN_SUBEXP, the contents, and an OP_CLOSE_SUBEXP.  */
+  op = create_tree (dfa, NULL, NULL, OP_OPEN_SUBEXP);
+  cls = create_tree (dfa, NULL, NULL, OP_CLOSE_SUBEXP);
+  tree1 = body ? create_tree (dfa, body, cls, CONCAT) : cls;
+  tree = create_tree (dfa, op, tree1, CONCAT);
+  if (BE (tree == NULL || tree1 == NULL || op == NULL || cls == NULL, 0))
+    {
+      *err = REG_ESPACE;
+      return NULL;
+    }
+
+  op->token.opr.idx = cls->token.opr.idx = node->token.opr.idx;
+  op->token.opt_subexp = cls->token.opt_subexp = node->token.opt_subexp;
+  return tree;
+}
+
+/* Pass 1 in building the NFA: compute FIRST and create unlinked automaton
+   nodes.  Requires a postorder visit.  */
+static reg_errcode_t
+calc_first (void *extra, bin_tree_t *node)
+{
+  re_dfa_t *dfa = (re_dfa_t *) extra;
+  if (node->token.type == CONCAT)
+    {
+      node->first = node->left->first;
+      node->node_idx = node->left->node_idx;
+    }
+  else
+    {
+      node->first = node;
+      node->node_idx = re_dfa_add_node (dfa, node->token);
+      if (BE (node->node_idx == -1, 0))
+	return REG_ESPACE;
+      if (node->token.type == ANCHOR)
+	dfa->nodes[node->node_idx].constraint = node->token.opr.ctx_type;
+    }
+  return REG_NOERROR;
+}
+
+/* Pass 2: compute NEXT on the tree.  Preorder visit.  */
+static reg_errcode_t
+calc_next (UNUSED void *extra, bin_tree_t *node)
+{
+  switch (node->token.type)
+    {
+    case OP_DUP_ASTERISK:
+      node->left->next = node;
+      break;
+    case CONCAT:
+      node->left->next = node->right->first;
+      node->right->next = node->next;
+      break;
+    default:
+      if (node->left)
+	node->left->next = node->next;
+      if (node->right)
+	node->right->next = node->next;
+      break;
+    }
+  return REG_NOERROR;
+}
+
+/* Pass 3: link all DFA nodes to their NEXT node (any order will do).  */
+static reg_errcode_t
+link_nfa_nodes (void *extra, bin_tree_t *node)
+{
+  re_dfa_t *dfa = (re_dfa_t *) extra;
+  int idx = node->node_idx;
+  reg_errcode_t err = REG_NOERROR;
+
+  switch (node->token.type)
+    {
+    case CONCAT:
+      break;
+
+    case END_OF_RE:
+      assert (node->next == NULL);
+      break;
+
+    case OP_DUP_ASTERISK:
+    case OP_ALT:
+      {
+	int left, right;
+	dfa->has_plural_match = 1;
+	if (node->left != NULL)
+	  left = node->left->first->node_idx;
+	else
+	  left = node->next->node_idx;
+	if (node->right != NULL)
+	  right = node->right->first->node_idx;
+	else
+	  right = node->next->node_idx;
+	assert (left > -1);
+	assert (right > -1);
+	err = re_node_set_init_2 (dfa->edests + idx, left, right);
+      }
+      break;
+
+    case ANCHOR:
+    case OP_OPEN_SUBEXP:
+    case OP_CLOSE_SUBEXP:
+      err = re_node_set_init_1 (dfa->edests + idx, node->next->node_idx);
+      break;
+
+    case OP_BACK_REF:
+      dfa->nexts[idx] = node->next->node_idx;
+      if (node->token.type == OP_BACK_REF)
+	err = re_node_set_init_1 (dfa->edests + idx, dfa->nexts[idx]);
+      break;
+
+    default:
+      assert (!IS_EPSILON_NODE (node->token.type));
+      dfa->nexts[idx] = node->next->node_idx;
+      break;
+    }
+
+  return err;
+}
+
+/* Duplicate the epsilon closure of the node ROOT_NODE.
+   Note that duplicated nodes have constraint INIT_CONSTRAINT in addition
+   to their own constraint.  */
+
+static reg_errcode_t
+internal_function
+duplicate_node_closure (re_dfa_t *dfa, int top_org_node, int top_clone_node,
+			int root_node, unsigned int init_constraint)
+{
+  int org_node, clone_node, ret;
+  unsigned int constraint = init_constraint;
+  for (org_node = top_org_node, clone_node = top_clone_node;;)
+    {
+      int org_dest, clone_dest;
+      if (dfa->nodes[org_node].type == OP_BACK_REF)
+	{
+	  /* If the back reference epsilon-transit, its destination must
+	     also have the constraint.  Then duplicate the epsilon closure
+	     of the destination of the back reference, and store it in
+	     edests of the back reference.  */
+	  org_dest = dfa->nexts[org_node];
+	  re_node_set_empty (dfa->edests + clone_node);
+	  clone_dest = duplicate_node (dfa, org_dest, constraint);
+	  if (BE (clone_dest == -1, 0))
+	    return REG_ESPACE;
+	  dfa->nexts[clone_node] = dfa->nexts[org_node];
+	  ret = re_node_set_insert (dfa->edests + clone_node, clone_dest);
+	  if (BE (ret < 0, 0))
+	    return REG_ESPACE;
+	}
+      else if (dfa->edests[org_node].nelem == 0)
+	{
+	  /* In case of the node can't epsilon-transit, don't duplicate the
+	     destination and store the original destination as the
+	     destination of the node.  */
+	  dfa->nexts[clone_node] = dfa->nexts[org_node];
+	  break;
+	}
+      else if (dfa->edests[org_node].nelem == 1)
+	{
+	  /* In case of the node can epsilon-transit, and it has only one
+	     destination.  */
+	  org_dest = dfa->edests[org_node].elems[0];
+	  re_node_set_empty (dfa->edests + clone_node);
+	  /* If the node is root_node itself, it means the epsilon clsoure
+	     has a loop.   Then tie it to the destination of the root_node.  */
+	  if (org_node == root_node && clone_node != org_node)
+	    {
+	      ret = re_node_set_insert (dfa->edests + clone_node, org_dest);
+	      if (BE (ret < 0, 0))
+		return REG_ESPACE;
+	      break;
+	    }
+	  /* In case of the node has another constraint, add it.  */
+	  constraint |= dfa->nodes[org_node].constraint;
+	  clone_dest = duplicate_node (dfa, org_dest, constraint);
+	  if (BE (clone_dest == -1, 0))
+	    return REG_ESPACE;
+	  ret = re_node_set_insert (dfa->edests + clone_node, clone_dest);
+	  if (BE (ret < 0, 0))
+	    return REG_ESPACE;
+	}
+      else /* dfa->edests[org_node].nelem == 2 */
+	{
+	  /* In case of the node can epsilon-transit, and it has two
+	     destinations. In the bin_tree_t and DFA, that's '|' and '*'.   */
+	  org_dest = dfa->edests[org_node].elems[0];
+	  re_node_set_empty (dfa->edests + clone_node);
+	  /* Search for a duplicated node which satisfies the constraint.  */
+	  clone_dest = search_duplicated_node (dfa, org_dest, constraint);
+	  if (clone_dest == -1)
+	    {
+	      /* There is no such duplicated node, create a new one.  */
+	      reg_errcode_t err;
+	      clone_dest = duplicate_node (dfa, org_dest, constraint);
+	      if (BE (clone_dest == -1, 0))
+		return REG_ESPACE;
+	      ret = re_node_set_insert (dfa->edests + clone_node, clone_dest);
+	      if (BE (ret < 0, 0))
+		return REG_ESPACE;
+	      err = duplicate_node_closure (dfa, org_dest, clone_dest,
+					    root_node, constraint);
+	      if (BE (err != REG_NOERROR, 0))
+		return err;
+	    }
+	  else
+	    {
+	      /* There is a duplicated node which satisfies the constraint,
+		 use it to avoid infinite loop.  */
+	      ret = re_node_set_insert (dfa->edests + clone_node, clone_dest);
+	      if (BE (ret < 0, 0))
+		return REG_ESPACE;
+	    }
+
+	  org_dest = dfa->edests[org_node].elems[1];
+	  clone_dest = duplicate_node (dfa, org_dest, constraint);
+	  if (BE (clone_dest == -1, 0))
+	    return REG_ESPACE;
+	  ret = re_node_set_insert (dfa->edests + clone_node, clone_dest);
+	  if (BE (ret < 0, 0))
+	    return REG_ESPACE;
+	}
+      org_node = org_dest;
+      clone_node = clone_dest;
+    }
+  return REG_NOERROR;
+}
+
+/* Search for a node which is duplicated from the node ORG_NODE, and
+   satisfies the constraint CONSTRAINT.  */
+
+static int
+search_duplicated_node (const re_dfa_t *dfa, int org_node,
+			unsigned int constraint)
+{
+  int idx;
+  for (idx = dfa->nodes_len - 1; dfa->nodes[idx].duplicated && idx > 0; --idx)
+    {
+      if (org_node == dfa->org_indices[idx]
+	  && constraint == dfa->nodes[idx].constraint)
+	return idx; /* Found.  */
+    }
+  return -1; /* Not found.  */
+}
+
+/* Duplicate the node whose index is ORG_IDX and set the constraint CONSTRAINT.
+   Return the index of the new node, or -1 if insufficient storage is
+   available.  */
+
+static int
+duplicate_node (re_dfa_t *dfa, int org_idx, unsigned int constraint)
+{
+  int dup_idx = re_dfa_add_node (dfa, dfa->nodes[org_idx]);
+  if (BE (dup_idx != -1, 1))
+    {
+      dfa->nodes[dup_idx].constraint = constraint;
+      dfa->nodes[dup_idx].constraint |= dfa->nodes[org_idx].constraint;
+      dfa->nodes[dup_idx].duplicated = 1;
+
+      /* Store the index of the original node.  */
+      dfa->org_indices[dup_idx] = org_idx;
+    }
+  return dup_idx;
+}
+
+static reg_errcode_t
+calc_inveclosure (re_dfa_t *dfa)
+{
+  int ret;
+  unsigned int src, idx;
+  for (idx = 0; idx < dfa->nodes_len; ++idx)
+    re_node_set_init_empty (dfa->inveclosures + idx);
+
+  for (src = 0; src < dfa->nodes_len; ++src)
+    {
+      int *elems = dfa->eclosures[src].elems;
+      int idx;
+      for (idx = 0; idx < dfa->eclosures[src].nelem; ++idx)
+	{
+	  ret = re_node_set_insert_last (dfa->inveclosures + elems[idx], src);
+	  if (BE (ret == -1, 0))
+	    return REG_ESPACE;
+	}
+    }
+
+  return REG_NOERROR;
+}
+
+/* Calculate "eclosure" for all the node in DFA.  */
+
+static reg_errcode_t
+calc_eclosure (re_dfa_t *dfa)
+{
+  size_t node_idx;
+  int incomplete;
+#ifdef DEBUG
+  assert (dfa->nodes_len > 0);
+#endif
+  incomplete = 0;
+  /* For each nodes, calculate epsilon closure.  */
+  for (node_idx = 0; ; ++node_idx)
+    {
+      reg_errcode_t err;
+      re_node_set eclosure_elem;
+      if (node_idx == dfa->nodes_len)
+	{
+	  if (!incomplete)
+	    break;
+	  incomplete = 0;
+	  node_idx = 0;
+	}
+
+#ifdef DEBUG
+      assert (dfa->eclosures[node_idx].nelem != -1);
+#endif
+
+      /* If we have already calculated, skip it.  */
+      if (dfa->eclosures[node_idx].nelem != 0)
+	continue;
+      /* Calculate epsilon closure of `node_idx'.  */
+      err = calc_eclosure_iter (&eclosure_elem, dfa, node_idx, 1);
+      if (BE (err != REG_NOERROR, 0))
+	return err;
+
+      if (dfa->eclosures[node_idx].nelem == 0)
+	{
+	  incomplete = 1;
+	  re_node_set_free (&eclosure_elem);
+	}
+    }
+  return REG_NOERROR;
+}
+
+/* Calculate epsilon closure of NODE.  */
+
+static reg_errcode_t
+calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa, int node, int root)
+{
+  reg_errcode_t err;
+  int i;
+  re_node_set eclosure;
+  int ret;
+  int incomplete = 0;
+  err = re_node_set_alloc (&eclosure, dfa->edests[node].nelem + 1);
+  if (BE (err != REG_NOERROR, 0))
+    return err;
+
+  /* This indicates that we are calculating this node now.
+     We reference this value to avoid infinite loop.  */
+  dfa->eclosures[node].nelem = -1;
+
+  /* If the current node has constraints, duplicate all nodes
+     since they must inherit the constraints.  */
+  if (dfa->nodes[node].constraint
+      && dfa->edests[node].nelem
+      && !dfa->nodes[dfa->edests[node].elems[0]].duplicated)
+    {
+      err = duplicate_node_closure (dfa, node, node, node,
+				    dfa->nodes[node].constraint);
+      if (BE (err != REG_NOERROR, 0))
+	return err;
+    }
+
+  /* Expand each epsilon destination nodes.  */
+  if (IS_EPSILON_NODE(dfa->nodes[node].type))
+    for (i = 0; i < dfa->edests[node].nelem; ++i)
+      {
+	re_node_set eclosure_elem;
+	int edest = dfa->edests[node].elems[i];
+	/* If calculating the epsilon closure of `edest' is in progress,
+	   return intermediate result.  */
+	if (dfa->eclosures[edest].nelem == -1)
+	  {
+	    incomplete = 1;
+	    continue;
+	  }
+	/* If we haven't calculated the epsilon closure of `edest' yet,
+	   calculate now. Otherwise use calculated epsilon closure.  */
+	if (dfa->eclosures[edest].nelem == 0)
+	  {
+	    err = calc_eclosure_iter (&eclosure_elem, dfa, edest, 0);
+	    if (BE (err != REG_NOERROR, 0))
+	      return err;
+	  }
+	else
+	  eclosure_elem = dfa->eclosures[edest];
+	/* Merge the epsilon closure of `edest'.  */
+	err = re_node_set_merge (&eclosure, &eclosure_elem);
+	if (BE (err != REG_NOERROR, 0))
+	  return err;
+	/* If the epsilon closure of `edest' is incomplete,
+	   the epsilon closure of this node is also incomplete.  */
+	if (dfa->eclosures[edest].nelem == 0)
+	  {
+	    incomplete = 1;
+	    re_node_set_free (&eclosure_elem);
+	  }
+      }
+
+  /* An epsilon closure includes itself.  */
+  ret = re_node_set_insert (&eclosure, node);
+  if (BE (ret < 0, 0))
+    return REG_ESPACE;
+  if (incomplete && !root)
+    dfa->eclosures[node].nelem = 0;
+  else
+    dfa->eclosures[node] = eclosure;
+  *new_set = eclosure;
+  return REG_NOERROR;
+}
+
+/* Functions for token which are used in the parser.  */
+
+/* Fetch a token from INPUT.
+   We must not use this function inside bracket expressions.  */
+
+static void
+internal_function
+fetch_token (re_token_t *result, re_string_t *input, reg_syntax_t syntax)
+{
+  re_string_skip_bytes (input, peek_token (result, input, syntax));
+}
+
+/* Peek a token from INPUT, and return the length of the token.
+   We must not use this function inside bracket expressions.  */
+
+static int
+internal_function
+peek_token (re_token_t *token, re_string_t *input, reg_syntax_t syntax)
+{
+  unsigned char c;
+
+  if (re_string_eoi (input))
+    {
+      token->type = END_OF_RE;
+      return 0;
+    }
+
+  c = re_string_peek_byte (input, 0);
+  token->opr.c = c;
+
+  token->word_char = 0;
+#ifdef RE_ENABLE_I18N
+  token->mb_partial = 0;
+  if (input->mb_cur_max > 1 &&
+      !re_string_first_byte (input, re_string_cur_idx (input)))
+    {
+      token->type = CHARACTER;
+      token->mb_partial = 1;
+      return 1;
+    }
+#endif
+  if (c == '\\')
+    {
+      unsigned char c2;
+      if (re_string_cur_idx (input) + 1 >= re_string_length (input))
+	{
+	  token->type = BACK_SLASH;
+	  return 1;
+	}
+
+      c2 = re_string_peek_byte_case (input, 1);
+      token->opr.c = c2;
+      token->type = CHARACTER;
+#ifdef RE_ENABLE_I18N
+      if (input->mb_cur_max > 1)
+	{
+	  wint_t wc = re_string_wchar_at (input,
+					  re_string_cur_idx (input) + 1);
+	  token->word_char = IS_WIDE_WORD_CHAR (wc) != 0;
+	}
+      else
+#endif
+	token->word_char = IS_WORD_CHAR (c2) != 0;
+
+      switch (c2)
+	{
+	case '|':
+	  if (!(syntax & RE_LIMITED_OPS) && !(syntax & RE_NO_BK_VBAR))
+	    token->type = OP_ALT;
+	  break;
+	case '1': case '2': case '3': case '4': case '5':
+	case '6': case '7': case '8': case '9':
+	  if (!(syntax & RE_NO_BK_REFS))
+	    {
+	      token->type = OP_BACK_REF;
+	      token->opr.idx = c2 - '1';
+	    }
+	  break;
+	case '<':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    {
+	      token->type = ANCHOR;
+	      token->opr.ctx_type = WORD_FIRST;
+	    }
+	  break;
+	case '>':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    {
+	      token->type = ANCHOR;
+	      token->opr.ctx_type = WORD_LAST;
+	    }
+	  break;
+	case 'b':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    {
+	      token->type = ANCHOR;
+	      token->opr.ctx_type = WORD_DELIM;
+	    }
+	  break;
+	case 'B':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    {
+	      token->type = ANCHOR;
+	      token->opr.ctx_type = NOT_WORD_DELIM;
+	    }
+	  break;
+	case 'w':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    token->type = OP_WORD;
+	  break;
+	case 'W':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    token->type = OP_NOTWORD;
+	  break;
+	case 's':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    token->type = OP_SPACE;
+	  break;
+	case 'S':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    token->type = OP_NOTSPACE;
+	  break;
+	case '`':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    {
+	      token->type = ANCHOR;
+	      token->opr.ctx_type = BUF_FIRST;
+	    }
+	  break;
+	case '\'':
+	  if (!(syntax & RE_NO_GNU_OPS))
+	    {
+	      token->type = ANCHOR;
+	      token->opr.ctx_type = BUF_LAST;
+	    }
+	  break;
+	case '(':
+	  if (!(syntax & RE_NO_BK_PARENS))
+	    token->type = OP_OPEN_SUBEXP;
+	  break;
+	case ')':
+	  if (!(syntax & RE_NO_BK_PARENS))
+	    token->type = OP_CLOSE_SUBEXP;
+	  break;
+	case '+':
+	  if (!(syntax & RE_LIMITED_OPS) && (syntax & RE_BK_PLUS_QM))
+	    token->type = OP_DUP_PLUS;
+	  break;
+	case '?':
+	  if (!(syntax & RE_LIMITED_OPS) && (syntax & RE_BK_PLUS_QM))
+	    token->type = OP_DUP_QUESTION;
+	  break;
+	case '{':
+	  if ((syntax & RE_INTERVALS) && (!(syntax & RE_NO_BK_BRACES)))
+	    token->type = OP_OPEN_DUP_NUM;
+	  break;
+	case '}':
+	  if ((syntax & RE_INTERVALS) && (!(syntax & RE_NO_BK_BRACES)))
+	    token->type = OP_CLOSE_DUP_NUM;
+	  break;
+	default:
+	  break;
+	}
+      return 2;
+    }
+
+  token->type = CHARACTER;
+#ifdef RE_ENABLE_I18N
+  if (input->mb_cur_max > 1)
+    {
+      wint_t wc = re_string_wchar_at (input, re_string_cur_idx (input));
+      token->word_char = IS_WIDE_WORD_CHAR (wc) != 0;
+    }
+  else
+#endif
+    token->word_char = IS_WORD_CHAR (token->opr.c);
+
+  switch (c)
+    {
+    case '\n':
+      if (syntax & RE_NEWLINE_ALT)
+	token->type = OP_ALT;
+      break;
+    case '|':
+      if (!(syntax & RE_LIMITED_OPS) && (syntax & RE_NO_BK_VBAR))
+	token->type = OP_ALT;
+      break;
+    case '*':
+      token->type = OP_DUP_ASTERISK;
+      break;
+    case '+':
+      if (!(syntax & RE_LIMITED_OPS) && !(syntax & RE_BK_PLUS_QM))
+	token->type = OP_DUP_PLUS;
+      break;
+    case '?':
+      if (!(syntax & RE_LIMITED_OPS) && !(syntax & RE_BK_PLUS_QM))
+	token->type = OP_DUP_QUESTION;
+      break;
+    case '{':
+      if ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
+	token->type = OP_OPEN_DUP_NUM;
+      break;
+    case '}':
+      if ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
+	token->type = OP_CLOSE_DUP_NUM;
+      break;
+    case '(':
+      if (syntax & RE_NO_BK_PARENS)
+	token->type = OP_OPEN_SUBEXP;
+      break;
+    case ')':
+      if (syntax & RE_NO_BK_PARENS)
+	token->type = OP_CLOSE_SUBEXP;
+      break;
+    case '[':
+      token->type = OP_OPEN_BRACKET;
+      break;
+    case '.':
+      token->type = OP_PERIOD;
+      break;
+    case '^':
+      if (!(syntax & (RE_CONTEXT_INDEP_ANCHORS | RE_CARET_ANCHORS_HERE)) &&
+	  re_string_cur_idx (input) != 0)
+	{
+	  char prev = re_string_peek_byte (input, -1);
+	  if (!(syntax & RE_NEWLINE_ALT) || prev != '\n')
+	    break;
+	}
+      token->type = ANCHOR;
+      token->opr.ctx_type = LINE_FIRST;
+      break;
+    case '$':
+      if (!(syntax & RE_CONTEXT_INDEP_ANCHORS) &&
+	  re_string_cur_idx (input) + 1 != re_string_length (input))
+	{
+	  re_token_t next;
+	  re_string_skip_bytes (input, 1);
+	  peek_token (&next, input, syntax);
+	  re_string_skip_bytes (input, -1);
+	  if (next.type != OP_ALT && next.type != OP_CLOSE_SUBEXP)
+	    break;
+	}
+      token->type = ANCHOR;
+      token->opr.ctx_type = LINE_LAST;
+      break;
+    default:
+      break;
+    }
+  return 1;
+}
+
+/* Peek a token from INPUT, and return the length of the token.
+   We must not use this function out of bracket expressions.  */
+
+static int
+internal_function
+peek_token_bracket (re_token_t *token, re_string_t *input, reg_syntax_t syntax)
+{
+  unsigned char c;
+  if (re_string_eoi (input))
+    {
+      token->type = END_OF_RE;
+      return 0;
+    }
+  c = re_string_peek_byte (input, 0);
+  token->opr.c = c;
+
+#ifdef RE_ENABLE_I18N
+  if (input->mb_cur_max > 1 &&
+      !re_string_first_byte (input, re_string_cur_idx (input)))
+    {
+      token->type = CHARACTER;
+      return 1;
+    }
+#endif /* RE_ENABLE_I18N */
+
+  if (c == '\\' && (syntax & RE_BACKSLASH_ESCAPE_IN_LISTS)
+      && re_string_cur_idx (input) + 1 < re_string_length (input))
+    {
+      /* In this case, '\' escape a character.  */
+      unsigned char c2;
+      re_string_skip_bytes (input, 1);
+      c2 = re_string_peek_byte (input, 0);
+      token->opr.c = c2;
+      token->type = CHARACTER;
+      return 1;
+    }
+  if (c == '[') /* '[' is a special char in a bracket exps.  */
+    {
+      unsigned char c2;
+      int token_len;
+      if (re_string_cur_idx (input) + 1 < re_string_length (input))
+	c2 = re_string_peek_byte (input, 1);
+      else
+	c2 = 0;
+      token->opr.c = c2;
+      token_len = 2;
+      switch (c2)
+	{
+	case '.':
+	  token->type = OP_OPEN_COLL_ELEM;
+	  break;
+	case '=':
+	  token->type = OP_OPEN_EQUIV_CLASS;
+	  break;
+	case ':':
+	  if (syntax & RE_CHAR_CLASSES)
+	    {
+	      token->type = OP_OPEN_CHAR_CLASS;
+	      break;
+	    }
+	  /* else fall through.  */
+	default:
+	  token->type = CHARACTER;
+	  token->opr.c = c;
+	  token_len = 1;
+	  break;
+	}
+      return token_len;
+    }
+  switch (c)
+    {
+    case '-':
+      token->type = OP_CHARSET_RANGE;
+      break;
+    case ']':
+      token->type = OP_CLOSE_BRACKET;
+      break;
+    case '^':
+      token->type = OP_NON_MATCH_LIST;
+      break;
+    default:
+      token->type = CHARACTER;
+    }
+  return 1;
+}
+
+/* Functions for parser.  */
+
+/* Entry point of the parser.
+   Parse the regular expression REGEXP and return the structure tree.
+   If an error is occured, ERR is set by error code, and return NULL.
+   This function build the following tree, from regular expression <reg_exp>:
+	   CAT
+	   / \
+	  /   \
+   <reg_exp>  EOR
+
+   CAT means concatenation.
+   EOR means end of regular expression.  */
+
+static bin_tree_t *
+parse (re_string_t *regexp, regex_t *preg, reg_syntax_t syntax,
+       reg_errcode_t *err)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  bin_tree_t *tree, *eor, *root;
+  re_token_t current_token;
+  dfa->syntax = syntax;
+  fetch_token (&current_token, regexp, syntax | RE_CARET_ANCHORS_HERE);
+  tree = parse_reg_exp (regexp, preg, &current_token, syntax, 0, err);
+  if (BE (*err != REG_NOERROR && tree == NULL, 0))
+    return NULL;
+  eor = create_tree (dfa, NULL, NULL, END_OF_RE);
+  if (tree != NULL)
+    root = create_tree (dfa, tree, eor, CONCAT);
+  else
+    root = eor;
+  if (BE (eor == NULL || root == NULL, 0))
+    {
+      *err = REG_ESPACE;
+      return NULL;
+    }
+  return root;
+}
+
+/* This function build the following tree, from regular expression
+   <branch1>|<branch2>:
+	   ALT
+	   / \
+	  /   \
+   <branch1> <branch2>
+
+   ALT means alternative, which represents the operator `|'.  */
+
+static bin_tree_t *
+parse_reg_exp (re_string_t *regexp, regex_t *preg, re_token_t *token,
+	       reg_syntax_t syntax, int nest, reg_errcode_t *err)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  bin_tree_t *tree, *branch = NULL;
+  tree = parse_branch (regexp, preg, token, syntax, nest, err);
+  if (BE (*err != REG_NOERROR && tree == NULL, 0))
+    return NULL;
+
+  while (token->type == OP_ALT)
+    {
+      fetch_token (token, regexp, syntax | RE_CARET_ANCHORS_HERE);
+      if (token->type != OP_ALT && token->type != END_OF_RE
+	  && (nest == 0 || token->type != OP_CLOSE_SUBEXP))
+	{
+	  branch = parse_branch (regexp, preg, token, syntax, nest, err);
+	  if (BE (*err != REG_NOERROR && branch == NULL, 0))
+	    return NULL;
+	}
+      else
+	branch = NULL;
+      tree = create_tree (dfa, tree, branch, OP_ALT);
+      if (BE (tree == NULL, 0))
+	{
+	  *err = REG_ESPACE;
+	  return NULL;
+	}
+    }
+  return tree;
+}
+
+/* This function build the following tree, from regular expression
+   <exp1><exp2>:
+	CAT
+	/ \
+       /   \
+   <exp1> <exp2>
+
+   CAT means concatenation.  */
+
+static bin_tree_t *
+parse_branch (re_string_t *regexp, regex_t *preg, re_token_t *token,
+	      reg_syntax_t syntax, int nest, reg_errcode_t *err)
+{
+  bin_tree_t *tree, *exp;
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  tree = parse_expression (regexp, preg, token, syntax, nest, err);
+  if (BE (*err != REG_NOERROR && tree == NULL, 0))
+    return NULL;
+
+  while (token->type != OP_ALT && token->type != END_OF_RE
+	 && (nest == 0 || token->type != OP_CLOSE_SUBEXP))
+    {
+      exp = parse_expression (regexp, preg, token, syntax, nest, err);
+      if (BE (*err != REG_NOERROR && exp == NULL, 0))
+	{
+	  return NULL;
+	}
+      if (tree != NULL && exp != NULL)
+	{
+	  tree = create_tree (dfa, tree, exp, CONCAT);
+	  if (tree == NULL)
+	    {
+	      *err = REG_ESPACE;
+	      return NULL;
+	    }
+	}
+      else if (tree == NULL)
+	tree = exp;
+      /* Otherwise exp == NULL, we don't need to create new tree.  */
+    }
+  return tree;
+}
+
+/* This function build the following tree, from regular expression a*:
+	 *
+	 |
+	 a
+*/
+
+static bin_tree_t *
+parse_expression (re_string_t *regexp, regex_t *preg, re_token_t *token,
+		  reg_syntax_t syntax, int nest, reg_errcode_t *err)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  bin_tree_t *tree;
+  switch (token->type)
+    {
+    case CHARACTER:
+      tree = create_token_tree (dfa, NULL, NULL, token);
+      if (BE (tree == NULL, 0))
+	{
+	  *err = REG_ESPACE;
+	  return NULL;
+	}
+#ifdef RE_ENABLE_I18N
+      if (dfa->mb_cur_max > 1)
+	{
+	  while (!re_string_eoi (regexp)
+		 && !re_string_first_byte (regexp, re_string_cur_idx (regexp)))
+	    {
+	      bin_tree_t *mbc_remain;
+	      fetch_token (token, regexp, syntax);
+	      mbc_remain = create_token_tree (dfa, NULL, NULL, token);
+	      tree = create_tree (dfa, tree, mbc_remain, CONCAT);
+	      if (BE (mbc_remain == NULL || tree == NULL, 0))
+		{
+		  *err = REG_ESPACE;
+		  return NULL;
+		}
+	    }
+	}
+#endif
+      break;
+    case OP_OPEN_SUBEXP:
+      tree = parse_sub_exp (regexp, preg, token, syntax, nest + 1, err);
+      if (BE (*err != REG_NOERROR && tree == NULL, 0))
+	return NULL;
+      break;
+    case OP_OPEN_BRACKET:
+      tree = parse_bracket_exp (regexp, dfa, token, syntax, err);
+      if (BE (*err != REG_NOERROR && tree == NULL, 0))
+	return NULL;
+      break;
+    case OP_BACK_REF:
+      if (!BE (dfa->completed_bkref_map & (1 << token->opr.idx), 1))
+	{
+	  *err = REG_ESUBREG;
+	  return NULL;
+	}
+      dfa->used_bkref_map |= 1 << token->opr.idx;
+      tree = create_token_tree (dfa, NULL, NULL, token);
+      if (BE (tree == NULL, 0))
+	{
+	  *err = REG_ESPACE;
+	  return NULL;
+	}
+      ++dfa->nbackref;
+      dfa->has_mb_node = 1;
+      break;
+    case OP_OPEN_DUP_NUM:
+      if (syntax & RE_CONTEXT_INVALID_DUP)
+	{
+	  *err = REG_BADRPT;
+	  return NULL;
+	}
+      /* FALLTHROUGH */
+    case OP_DUP_ASTERISK:
+    case OP_DUP_PLUS:
+    case OP_DUP_QUESTION:
+      if (syntax & RE_CONTEXT_INVALID_OPS)
+	{
+	  *err = REG_BADRPT;
+	  return NULL;
+	}
+      else if (syntax & RE_CONTEXT_INDEP_OPS)
+	{
+	  fetch_token (token, regexp, syntax);
+	  return parse_expression (regexp, preg, token, syntax, nest, err);
+	}
+      /* else fall through  */
+    case OP_CLOSE_SUBEXP:
+      if ((token->type == OP_CLOSE_SUBEXP) &&
+	  !(syntax & RE_UNMATCHED_RIGHT_PAREN_ORD))
+	{
+	  *err = REG_ERPAREN;
+	  return NULL;
+	}
+      /* else fall through  */
+    case OP_CLOSE_DUP_NUM:
+      /* We treat it as a normal character.  */
+
+      /* Then we can these characters as normal characters.  */
+      token->type = CHARACTER;
+      /* mb_partial and word_char bits should be initialized already
+	 by peek_token.  */
+      tree = create_token_tree (dfa, NULL, NULL, token);
+      if (BE (tree == NULL, 0))
+	{
+	  *err = REG_ESPACE;
+	  return NULL;
+	}
+      break;
+    case ANCHOR:
+      if ((token->opr.ctx_type
+	   & (WORD_DELIM | NOT_WORD_DELIM | WORD_FIRST | WORD_LAST))
+	  && dfa->word_ops_used == 0)
+	init_word_char (dfa);
+      if (token->opr.ctx_type == WORD_DELIM
+	  || token->opr.ctx_type == NOT_WORD_DELIM)
+	{
+	  bin_tree_t *tree_first, *tree_last;
+	  if (token->opr.ctx_type == WORD_DELIM)
+	    {
+	      token->opr.ctx_type = WORD_FIRST;
+	      tree_first = create_token_tree (dfa, NULL, NULL, token);
+	      token->opr.ctx_type = WORD_LAST;
+	    }
+	  else
+	    {
+	      token->opr.ctx_type = INSIDE_WORD;
+	      tree_first = create_token_tree (dfa, NULL, NULL, token);
+	      token->opr.ctx_type = INSIDE_NOTWORD;
+	    }
+	  tree_last = create_token_tree (dfa, NULL, NULL, token);
+	  tree = create_tree (dfa, tree_first, tree_last, OP_ALT);
+	  if (BE (tree_first == NULL || tree_last == NULL || tree == NULL, 0))
+	    {
+	      *err = REG_ESPACE;
+	      return NULL;
+	    }
+	}
+      else
+	{
+	  tree = create_token_tree (dfa, NULL, NULL, token);
+	  if (BE (tree == NULL, 0))
+	    {
+	      *err = REG_ESPACE;
+	      return NULL;
+	    }
+	}
+      /* We must return here, since ANCHORs can't be followed
+	 by repetition operators.
+	 eg. RE"^*" is invalid or "<ANCHOR(^)><CHAR(*)>",
+	     it must not be "<ANCHOR(^)><REPEAT(*)>".  */
+      fetch_token (token, regexp, syntax);
+      return tree;
+    case OP_PERIOD:
+      tree = create_token_tree (dfa, NULL, NULL, token);
+      if (BE (tree == NULL, 0))
+	{
+	  *err = REG_ESPACE;
+	  return NULL;
+	}
+      if (dfa->mb_cur_max > 1)
+	dfa->has_mb_node = 1;
+      break;
+    case OP_WORD:
+    case OP_NOTWORD:
+      tree = build_charclass_op (dfa, regexp->trans,
+				 "alnum",
+				 "_",
+				 token->type == OP_NOTWORD, err);
+      if (BE (*err != REG_NOERROR && tree == NULL, 0))
+	return NULL;
+      break;
+    case OP_SPACE:
+    case OP_NOTSPACE:
+      tree = build_charclass_op (dfa, regexp->trans,
+				 "space",
+				 "",
+				 token->type == OP_NOTSPACE, err);
+      if (BE (*err != REG_NOERROR && tree == NULL, 0))
+	return NULL;
+      break;
+    case OP_ALT:
+    case END_OF_RE:
+      return NULL;
+    case BACK_SLASH:
+      *err = REG_EESCAPE;
+      return NULL;
+    default:
+      /* Must not happen?  */
+#ifdef DEBUG
+      assert (0);
+#endif
+      return NULL;
+    }
+  fetch_token (token, regexp, syntax);
+
+  while (token->type == OP_DUP_ASTERISK || token->type == OP_DUP_PLUS
+	 || token->type == OP_DUP_QUESTION || token->type == OP_OPEN_DUP_NUM)
+    {
+      tree = parse_dup_op (tree, regexp, dfa, token, syntax, err);
+      if (BE (*err != REG_NOERROR && tree == NULL, 0))
+	return NULL;
+      /* In BRE consecutive duplications are not allowed.  */
+      if ((syntax & RE_CONTEXT_INVALID_DUP)
+	  && (token->type == OP_DUP_ASTERISK
+	      || token->type == OP_OPEN_DUP_NUM))
+	{
+	  *err = REG_BADRPT;
+	  return NULL;
+	}
+    }
+
+  return tree;
+}
+
+/* This function build the following tree, from regular expression
+   (<reg_exp>):
+	 SUBEXP
+	    |
+	<reg_exp>
+*/
+
+static bin_tree_t *
+parse_sub_exp (re_string_t *regexp, regex_t *preg, re_token_t *token,
+	       reg_syntax_t syntax, int nest, reg_errcode_t *err)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  bin_tree_t *tree;
+  size_t cur_nsub;
+  cur_nsub = preg->re_nsub++;
+
+  fetch_token (token, regexp, syntax | RE_CARET_ANCHORS_HERE);
+
+  /* The subexpression may be a null string.  */
+  if (token->type == OP_CLOSE_SUBEXP)
+    tree = NULL;
+  else
+    {
+      tree = parse_reg_exp (regexp, preg, token, syntax, nest, err);
+      if (BE (*err == REG_NOERROR && token->type != OP_CLOSE_SUBEXP, 0))
+	*err = REG_EPAREN;
+      if (BE (*err != REG_NOERROR, 0))
+	return NULL;
+    }
+
+  if (cur_nsub <= '9' - '1')
+    dfa->completed_bkref_map |= 1 << cur_nsub;
+
+  tree = create_tree (dfa, tree, NULL, SUBEXP);
+  if (BE (tree == NULL, 0))
+    {
+      *err = REG_ESPACE;
+      return NULL;
+    }
+  tree->token.opr.idx = cur_nsub;
+  return tree;
+}
+
+/* This function parse repetition operators like "*", "+", "{1,3}" etc.  */
+
+static bin_tree_t *
+parse_dup_op (bin_tree_t *elem, re_string_t *regexp, re_dfa_t *dfa,
+	      re_token_t *token, reg_syntax_t syntax, reg_errcode_t *err)
+{
+  bin_tree_t *tree = NULL, *old_tree = NULL;
+  int i, start, end, start_idx = re_string_cur_idx (regexp);
+#ifndef RE_TOKEN_INIT_BUG
+  re_token_t start_token = *token;
+#else
+  re_token_t start_token;
+
+  memcpy ((void *) &start_token, (void *) token, sizeof start_token);
+#endif
+
+  if (token->type == OP_OPEN_DUP_NUM)
+    {
+      end = 0;
+      start = fetch_number (regexp, token, syntax);
+      if (start == -1)
+	{
+	  if (token->type == CHARACTER && token->opr.c == ',')
+	    start = 0; /* We treat "{,m}" as "{0,m}".  */
+	  else
+	    {
+	      *err = REG_BADBR; /* <re>{} is invalid.  */
+	      return NULL;
+	    }
+	}
+      if (BE (start != -2, 1))
+	{
+	  /* We treat "{n}" as "{n,n}".  */
+	  end = ((token->type == OP_CLOSE_DUP_NUM) ? start
+		 : ((token->type == CHARACTER && token->opr.c == ',')
+		    ? fetch_number (regexp, token, syntax) : -2));
+	}
+      if (BE (start == -2 || end == -2, 0))
+	{
+	  /* Invalid sequence.  */
+	  if (BE (!(syntax & RE_INVALID_INTERVAL_ORD), 0))
+	    {
+	      if (token->type == END_OF_RE)
+		*err = REG_EBRACE;
+	      else
+		*err = REG_BADBR;
+
+	      return NULL;
+	    }
+
+	  /* If the syntax bit is set, rollback.  */
+	  re_string_set_index (regexp, start_idx);
+	  *token = start_token;
+	  token->type = CHARACTER;
+	  /* mb_partial and word_char bits should be already initialized by
+	     peek_token.  */
+	  return elem;
+	}
+
+      if (BE ((end != -1 && start > end) || token->type != OP_CLOSE_DUP_NUM, 0))
+	{
+	  /* First number greater than second.  */
+	  *err = REG_BADBR;
+	  return NULL;
+	}
+    }
+  else
+    {
+      start = (token->type == OP_DUP_PLUS) ? 1 : 0;
+      end = (token->type == OP_DUP_QUESTION) ? 1 : -1;
+    }
+
+  fetch_token (token, regexp, syntax);
+
+  if (BE (elem == NULL, 0))
+    return NULL;
+  if (BE (start == 0 && end == 0, 0))
+    {
+      postorder (elem, free_tree, NULL);
+      return NULL;
+    }
+
+  /* Extract "<re>{n,m}" to "<re><re>...<re><re>{0,<m-n>}".  */
+  if (BE (start > 0, 0))
+    {
+      tree = elem;
+      for (i = 2; i <= start; ++i)
+	{
+	  elem = duplicate_tree (elem, dfa);
+	  tree = create_tree (dfa, tree, elem, CONCAT);
+	  if (BE (elem == NULL || tree == NULL, 0))
+	    goto parse_dup_op_espace;
+	}
+
+      if (start == end)
+	return tree;
+
+      /* Duplicate ELEM before it is marked optional.  */
+      elem = duplicate_tree (elem, dfa);
+      old_tree = tree;
+    }
+  else
+    old_tree = NULL;
+
+  if (elem->token.type == SUBEXP)
+    postorder (elem, mark_opt_subexp, (void *) (long) elem->token.opr.idx);
+
+  tree = create_tree (dfa, elem, NULL, (end == -1 ? OP_DUP_ASTERISK : OP_ALT));
+  if (BE (tree == NULL, 0))
+    goto parse_dup_op_espace;
+
+  /* This loop is actually executed only when end != -1,
+     to rewrite <re>{0,n} as (<re>(<re>...<re>?)?)?...  We have
+     already created the start+1-th copy.  */
+  for (i = start + 2; i <= end; ++i)
+    {
+      elem = duplicate_tree (elem, dfa);
+      tree = create_tree (dfa, tree, elem, CONCAT);
+      if (BE (elem == NULL || tree == NULL, 0))
+	goto parse_dup_op_espace;
+
+      tree = create_tree (dfa, tree, NULL, OP_ALT);
+      if (BE (tree == NULL, 0))
+	goto parse_dup_op_espace;
+    }
+
+  if (old_tree)
+    tree = create_tree (dfa, old_tree, tree, CONCAT);
+
+  return tree;
+
+ parse_dup_op_espace:
+  *err = REG_ESPACE;
+  return NULL;
+}
+
+/* Size of the names for collating symbol/equivalence_class/character_class.
+   I'm not sure, but maybe enough.  */
+#define BRACKET_NAME_BUF_SIZE 32
+
+#ifndef _LIBC
+  /* Local function for parse_bracket_exp only used in case of NOT _LIBC.
+     Build the range expression which starts from START_ELEM, and ends
+     at END_ELEM.  The result are written to MBCSET and SBCSET.
+     RANGE_ALLOC is the allocated size of mbcset->range_starts, and
+     mbcset->range_ends, is a pointer argument sinse we may
+     update it.  */
+
+static reg_errcode_t
+internal_function
+# ifdef RE_ENABLE_I18N
+build_range_exp (bitset_t sbcset, re_charset_t *mbcset, int *range_alloc,
+		 bracket_elem_t *start_elem, bracket_elem_t *end_elem)
+# else /* not RE_ENABLE_I18N */
+build_range_exp (bitset_t sbcset, bracket_elem_t *start_elem,
+		 bracket_elem_t *end_elem)
+# endif /* not RE_ENABLE_I18N */
+{
+  unsigned int start_ch, end_ch;
+  /* Equivalence Classes and Character Classes can't be a range start/end.  */
+  if (BE (start_elem->type == EQUIV_CLASS || start_elem->type == CHAR_CLASS
+	  || end_elem->type == EQUIV_CLASS || end_elem->type == CHAR_CLASS,
+	  0))
+    return REG_ERANGE;
+
+  /* We can handle no multi character collating elements without libc
+     support.  */
+  if (BE ((start_elem->type == COLL_SYM
+	   && strlen ((char *) start_elem->opr.name) > 1)
+	  || (end_elem->type == COLL_SYM
+	      && strlen ((char *) end_elem->opr.name) > 1), 0))
+    return REG_ECOLLATE;
+
+# ifdef RE_ENABLE_I18N
+  {
+    wchar_t wc;
+    wint_t start_wc;
+    wint_t end_wc;
+    wchar_t cmp_buf[6] = {L'\0', L'\0', L'\0', L'\0', L'\0', L'\0'};
+
+    start_ch = ((start_elem->type == SB_CHAR) ? start_elem->opr.ch
+		: ((start_elem->type == COLL_SYM) ? start_elem->opr.name[0]
+		   : 0));
+    end_ch = ((end_elem->type == SB_CHAR) ? end_elem->opr.ch
+	      : ((end_elem->type == COLL_SYM) ? end_elem->opr.name[0]
+		 : 0));
+#ifdef GAWK
+    /*
+     * Fedora Core 2, maybe others, have broken `btowc' that returns -1
+     * for any value > 127. Sigh. Note that `start_ch' and `end_ch' are
+     * unsigned, so we don't have sign extension problems.
+     */
+    start_wc = ((start_elem->type == SB_CHAR || start_elem->type == COLL_SYM)
+		? start_ch : start_elem->opr.wch);
+    end_wc = ((end_elem->type == SB_CHAR || end_elem->type == COLL_SYM)
+	      ? end_ch : end_elem->opr.wch);
+#else
+    start_wc = ((start_elem->type == SB_CHAR || start_elem->type == COLL_SYM)
+		? __btowc (start_ch) : start_elem->opr.wch);
+    end_wc = ((end_elem->type == SB_CHAR || end_elem->type == COLL_SYM)
+	      ? __btowc (end_ch) : end_elem->opr.wch);
+#endif
+    if (start_wc == WEOF || end_wc == WEOF)
+      return REG_ECOLLATE;
+    cmp_buf[0] = start_wc;
+    cmp_buf[4] = end_wc;
+    if (wcscoll (cmp_buf, cmp_buf + 4) > 0)
+      return REG_ERANGE;
+
+    /* Got valid collation sequence values, add them as a new entry.
+       However, for !_LIBC we have no collation elements: if the
+       character set is single byte, the single byte character set
+       that we build below suffices.  parse_bracket_exp passes
+       no MBCSET if dfa->mb_cur_max == 1.  */
+    if (mbcset)
+      {
+	/* Check the space of the arrays.  */
+	if (BE (*range_alloc == mbcset->nranges, 0))
+	  {
+	    /* There is not enough space, need realloc.  */
+	    wchar_t *new_array_start, *new_array_end;
+	    int new_nranges;
+
+	    /* +1 in case of mbcset->nranges is 0.  */
+	    new_nranges = 2 * mbcset->nranges + 1;
+	    /* Use realloc since mbcset->range_starts and mbcset->range_ends
+	       are NULL if *range_alloc == 0.  */
+	    new_array_start = re_realloc (mbcset->range_starts, wchar_t,
+					  new_nranges);
+	    new_array_end = re_realloc (mbcset->range_ends, wchar_t,
+					new_nranges);
+
+	    if (BE (new_array_start == NULL || new_array_end == NULL, 0))
+	      return REG_ESPACE;
+
+	    mbcset->range_starts = new_array_start;
+	    mbcset->range_ends = new_array_end;
+	    *range_alloc = new_nranges;
+	  }
+
+	mbcset->range_starts[mbcset->nranges] = start_wc;
+	mbcset->range_ends[mbcset->nranges++] = end_wc;
+      }
+
+    /* Build the table for single byte characters.  */
+    for (wc = 0; wc < SBC_MAX; ++wc)
+      {
+	cmp_buf[2] = wc;
+	if (wcscoll (cmp_buf, cmp_buf + 2) <= 0
+	    && wcscoll (cmp_buf + 2, cmp_buf + 4) <= 0)
+	  bitset_set (sbcset, wc);
+      }
+  }
+# else /* not RE_ENABLE_I18N */
+  {
+    unsigned int ch;
+    start_ch = ((start_elem->type == SB_CHAR ) ? start_elem->opr.ch
+		: ((start_elem->type == COLL_SYM) ? start_elem->opr.name[0]
+		   : 0));
+    end_ch = ((end_elem->type == SB_CHAR ) ? end_elem->opr.ch
+	      : ((end_elem->type == COLL_SYM) ? end_elem->opr.name[0]
+		 : 0));
+    if (start_ch > end_ch)
+      return REG_ERANGE;
+    /* Build the table for single byte characters.  */
+    for (ch = 0; ch < SBC_MAX; ++ch)
+      if (start_ch <= ch  && ch <= end_ch)
+	bitset_set (sbcset, ch);
+  }
+# endif /* not RE_ENABLE_I18N */
+  return REG_NOERROR;
+}
+#endif /* not _LIBC */
+
+#ifndef _LIBC
+/* Helper function for parse_bracket_exp only used in case of NOT _LIBC..
+   Build the collating element which is represented by NAME.
+   The result are written to MBCSET and SBCSET.
+   COLL_SYM_ALLOC is the allocated size of mbcset->coll_sym, is a
+   pointer argument since we may update it.  */
+
+static reg_errcode_t
+internal_function
+# ifdef RE_ENABLE_I18N
+build_collating_symbol (bitset_t sbcset, re_charset_t *mbcset,
+			int *coll_sym_alloc, const unsigned char *name)
+# else /* not RE_ENABLE_I18N */
+build_collating_symbol (bitset_t sbcset, const unsigned char *name)
+# endif /* not RE_ENABLE_I18N */
+{
+  size_t name_len = strlen ((const char *) name);
+  if (BE (name_len != 1, 0))
+    return REG_ECOLLATE;
+  else
+    {
+      bitset_set (sbcset, name[0]);
+      return REG_NOERROR;
+    }
+}
+#endif /* not _LIBC */
+
+/* This function parse bracket expression like "[abc]", "[a-c]",
+   "[[.a-a.]]" etc.  */
+
+static bin_tree_t *
+parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa, re_token_t *token,
+		   reg_syntax_t syntax, reg_errcode_t *err)
+{
+#ifdef _LIBC
+  const unsigned char *collseqmb;
+  const char *collseqwc;
+  uint32_t nrules;
+  int32_t table_size;
+  const int32_t *symb_table;
+  const unsigned char *extra;
+
+  /* Local function for parse_bracket_exp used in _LIBC environement.
+     Seek the collating symbol entry correspondings to NAME.
+     Return the index of the symbol in the SYMB_TABLE.  */
+
+  auto inline int32_t
+  __attribute ((always_inline))
+  seek_collating_symbol_entry (name, name_len)
+	 const unsigned char *name;
+	 size_t name_len;
+    {
+      int32_t hash = elem_hash ((const char *) name, name_len);
+      int32_t elem = hash % table_size;
+      if (symb_table[2 * elem] != 0)
+	{
+	  int32_t second = hash % (table_size - 2) + 1;
+
+	  do
+	    {
+	      /* First compare the hashing value.  */
+	      if (symb_table[2 * elem] == hash
+		  /* Compare the length of the name.  */
+		  && name_len == extra[symb_table[2 * elem + 1]]
+		  /* Compare the name.  */
+		  && memcmp (name, &extra[symb_table[2 * elem + 1] + 1],
+			     name_len) == 0)
+		{
+		  /* Yep, this is the entry.  */
+		  break;
+		}
+
+	      /* Next entry.  */
+	      elem += second;
+	    }
+	  while (symb_table[2 * elem] != 0);
+	}
+      return elem;
+    }
+
+  /* Local function for parse_bracket_exp used in _LIBC environment.
+     Look up the collation sequence value of BR_ELEM.
+     Return the value if succeeded, UINT_MAX otherwise.  */
+
+  auto inline unsigned int
+  __attribute ((always_inline))
+  lookup_collation_sequence_value (br_elem)
+	 bracket_elem_t *br_elem;
+    {
+      if (br_elem->type == SB_CHAR)
+	{
+	  /*
+	  if (MB_CUR_MAX == 1)
+	  */
+	  if (nrules == 0)
+	    return collseqmb[br_elem->opr.ch];
+	  else
+	    {
+	      wint_t wc = __btowc (br_elem->opr.ch);
+	      return __collseq_table_lookup (collseqwc, wc);
+	    }
+	}
+      else if (br_elem->type == MB_CHAR)
+	{
+	  if (nrules != 0)
+	    return __collseq_table_lookup (collseqwc, br_elem->opr.wch);
+	}
+      else if (br_elem->type == COLL_SYM)
+	{
+	  size_t sym_name_len = strlen ((char *) br_elem->opr.name);
+	  if (nrules != 0)
+	    {
+	      int32_t elem, idx;
+	      elem = seek_collating_symbol_entry (br_elem->opr.name,
+						  sym_name_len);
+	      if (symb_table[2 * elem] != 0)
+		{
+		  /* We found the entry.  */
+		  idx = symb_table[2 * elem + 1];
+		  /* Skip the name of collating element name.  */
+		  idx += 1 + extra[idx];
+		  /* Skip the byte sequence of the collating element.  */
+		  idx += 1 + extra[idx];
+		  /* Adjust for the alignment.  */
+		  idx = (idx + 3) & ~3;
+		  /* Skip the multibyte collation sequence value.  */
+		  idx += sizeof (unsigned int);
+		  /* Skip the wide char sequence of the collating element.  */
+		  idx += sizeof (unsigned int) *
+		    (1 + *(unsigned int *) (extra + idx));
+		  /* Return the collation sequence value.  */
+		  return *(unsigned int *) (extra + idx);
+		}
+	      else if (symb_table[2 * elem] == 0 && sym_name_len == 1)
+		{
+		  /* No valid character.  Match it as a single byte
+		     character.  */
+		  return collseqmb[br_elem->opr.name[0]];
+		}
+	    }
+	  else if (sym_name_len == 1)
+	    return collseqmb[br_elem->opr.name[0]];
+	}
+      return UINT_MAX;
+    }
+
+  /* Local function for parse_bracket_exp used in _LIBC environement.
+     Build the range expression which starts from START_ELEM, and ends
+     at END_ELEM.  The result are written to MBCSET and SBCSET.
+     RANGE_ALLOC is the allocated size of mbcset->range_starts, and
+     mbcset->range_ends, is a pointer argument sinse we may
+     update it.  */
+
+  auto inline reg_errcode_t
+  __attribute ((always_inline))
+  build_range_exp (sbcset, mbcset, range_alloc, start_elem, end_elem)
+	 re_charset_t *mbcset;
+	 int *range_alloc;
+	 bitset_t sbcset;
+	 bracket_elem_t *start_elem, *end_elem;
+    {
+      unsigned int ch;
+      uint32_t start_collseq;
+      uint32_t end_collseq;
+
+      /* Equivalence Classes and Character Classes can't be a range
+	 start/end.  */
+      if (BE (start_elem->type == EQUIV_CLASS || start_elem->type == CHAR_CLASS
+	      || end_elem->type == EQUIV_CLASS || end_elem->type == CHAR_CLASS,
+	      0))
+	return REG_ERANGE;
+
+      start_collseq = lookup_collation_sequence_value (start_elem);
+      end_collseq = lookup_collation_sequence_value (end_elem);
+      /* Check start/end collation sequence values.  */
+      if (BE (start_collseq == UINT_MAX || end_collseq == UINT_MAX, 0))
+	return REG_ECOLLATE;
+      if (BE ((syntax & RE_NO_EMPTY_RANGES) && start_collseq > end_collseq, 0))
+	return REG_ERANGE;
+
+      /* Got valid collation sequence values, add them as a new entry.
+	 However, if we have no collation elements, and the character set
+	 is single byte, the single byte character set that we
+	 build below suffices. */
+      if (nrules > 0 || dfa->mb_cur_max > 1)
+	{
+	  /* Check the space of the arrays.  */
+	  if (BE (*range_alloc == mbcset->nranges, 0))
+	    {
+	      /* There is not enough space, need realloc.  */
+	      uint32_t *new_array_start;
+	      uint32_t *new_array_end;
+	      int new_nranges;
+
+	      /* +1 in case of mbcset->nranges is 0.  */
+	      new_nranges = 2 * mbcset->nranges + 1;
+	      new_array_start = re_realloc (mbcset->range_starts, uint32_t,
+					    new_nranges);
+	      new_array_end = re_realloc (mbcset->range_ends, uint32_t,
+					  new_nranges);
+
+	      if (BE (new_array_start == NULL || new_array_end == NULL, 0))
+		return REG_ESPACE;
+
+	      mbcset->range_starts = new_array_start;
+	      mbcset->range_ends = new_array_end;
+	      *range_alloc = new_nranges;
+	    }
+
+	  mbcset->range_starts[mbcset->nranges] = start_collseq;
+	  mbcset->range_ends[mbcset->nranges++] = end_collseq;
+	}
+
+      /* Build the table for single byte characters.  */
+      for (ch = 0; ch < SBC_MAX; ch++)
+	{
+	  uint32_t ch_collseq;
+	  /*
+	  if (MB_CUR_MAX == 1)
+	  */
+	  if (nrules == 0)
+	    ch_collseq = collseqmb[ch];
+	  else
+	    ch_collseq = __collseq_table_lookup (collseqwc, __btowc (ch));
+	  if (start_collseq <= ch_collseq && ch_collseq <= end_collseq)
+	    bitset_set (sbcset, ch);
+	}
+      return REG_NOERROR;
+    }
+
+  /* Local function for parse_bracket_exp used in _LIBC environement.
+     Build the collating element which is represented by NAME.
+     The result are written to MBCSET and SBCSET.
+     COLL_SYM_ALLOC is the allocated size of mbcset->coll_sym, is a
+     pointer argument sinse we may update it.  */
+
+  auto inline reg_errcode_t
+  __attribute ((always_inline))
+  build_collating_symbol (sbcset, mbcset, coll_sym_alloc, name)
+	 re_charset_t *mbcset;
+	 int *coll_sym_alloc;
+	 bitset_t sbcset;
+	 const unsigned char *name;
+    {
+      int32_t elem, idx;
+      size_t name_len = strlen ((const char *) name);
+      if (nrules != 0)
+	{
+	  elem = seek_collating_symbol_entry (name, name_len);
+	  if (symb_table[2 * elem] != 0)
+	    {
+	      /* We found the entry.  */
+	      idx = symb_table[2 * elem + 1];
+	      /* Skip the name of collating element name.  */
+	      idx += 1 + extra[idx];
+	    }
+	  else if (symb_table[2 * elem] == 0 && name_len == 1)
+	    {
+	      /* No valid character, treat it as a normal
+		 character.  */
+	      bitset_set (sbcset, name[0]);
+	      return REG_NOERROR;
+	    }
+	  else
+	    return REG_ECOLLATE;
+
+	  /* Got valid collation sequence, add it as a new entry.  */
+	  /* Check the space of the arrays.  */
+	  if (BE (*coll_sym_alloc == mbcset->ncoll_syms, 0))
+	    {
+	      /* Not enough, realloc it.  */
+	      /* +1 in case of mbcset->ncoll_syms is 0.  */
+	      int new_coll_sym_alloc = 2 * mbcset->ncoll_syms + 1;
+	      /* Use realloc since mbcset->coll_syms is NULL
+		 if *alloc == 0.  */
+	      int32_t *new_coll_syms = re_realloc (mbcset->coll_syms, int32_t,
+						   new_coll_sym_alloc);
+	      if (BE (new_coll_syms == NULL, 0))
+		return REG_ESPACE;
+	      mbcset->coll_syms = new_coll_syms;
+	      *coll_sym_alloc = new_coll_sym_alloc;
+	    }
+	  mbcset->coll_syms[mbcset->ncoll_syms++] = idx;
+	  return REG_NOERROR;
+	}
+      else
+	{
+	  if (BE (name_len != 1, 0))
+	    return REG_ECOLLATE;
+	  else
+	    {
+	      bitset_set (sbcset, name[0]);
+	      return REG_NOERROR;
+	    }
+	}
+    }
+#endif
+
+  re_token_t br_token;
+  re_bitset_ptr_t sbcset;
+#ifdef RE_ENABLE_I18N
+  re_charset_t *mbcset;
+  int coll_sym_alloc = 0, range_alloc = 0, mbchar_alloc = 0;
+  int equiv_class_alloc = 0, char_class_alloc = 0;
+#endif /* not RE_ENABLE_I18N */
+  int non_match = 0;
+  bin_tree_t *work_tree;
+  int token_len;
+  int first_round = 1;
+#ifdef _LIBC
+  collseqmb = (const unsigned char *)
+    _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQMB);
+  nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+  if (nrules)
+    {
+      /*
+      if (MB_CUR_MAX > 1)
+      */
+      collseqwc = _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQWC);
+      table_size = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_SYMB_HASH_SIZEMB);
+      symb_table = (const int32_t *) _NL_CURRENT (LC_COLLATE,
+						  _NL_COLLATE_SYMB_TABLEMB);
+      extra = (const unsigned char *) _NL_CURRENT (LC_COLLATE,
+						   _NL_COLLATE_SYMB_EXTRAMB);
+    }
+#endif
+  sbcset = (re_bitset_ptr_t) calloc (sizeof (bitset_t), 1);
+#ifdef RE_ENABLE_I18N
+  mbcset = (re_charset_t *) calloc (sizeof (re_charset_t), 1);
+#endif /* RE_ENABLE_I18N */
+#ifdef RE_ENABLE_I18N
+  if (BE (sbcset == NULL || mbcset == NULL, 0))
+#else
+  if (BE (sbcset == NULL, 0))
+#endif /* RE_ENABLE_I18N */
+    {
+      *err = REG_ESPACE;
+      return NULL;
+    }
+
+  token_len = peek_token_bracket (token, regexp, syntax);
+  if (BE (token->type == END_OF_RE, 0))
+    {
+      *err = REG_BADPAT;
+      goto parse_bracket_exp_free_return;
+    }
+  if (token->type == OP_NON_MATCH_LIST)
+    {
+#ifdef RE_ENABLE_I18N
+      mbcset->non_match = 1;
+#endif /* not RE_ENABLE_I18N */
+      non_match = 1;
+      if (syntax & RE_HAT_LISTS_NOT_NEWLINE)
+	bitset_set (sbcset, '\n');
+      re_string_skip_bytes (regexp, token_len); /* Skip a token.  */
+      token_len = peek_token_bracket (token, regexp, syntax);
+      if (BE (token->type == END_OF_RE, 0))
+	{
+	  *err = REG_BADPAT;
+	  goto parse_bracket_exp_free_return;
+	}
+    }
+
+  /* We treat the first ']' as a normal character.  */
+  if (token->type == OP_CLOSE_BRACKET)
+    token->type = CHARACTER;
+
+  while (1)
+    {
+      bracket_elem_t start_elem, end_elem;
+      unsigned char start_name_buf[BRACKET_NAME_BUF_SIZE];
+      unsigned char end_name_buf[BRACKET_NAME_BUF_SIZE];
+      reg_errcode_t ret;
+      int token_len2 = 0, is_range_exp = 0;
+      re_token_t token2;
+
+      start_elem.opr.name = start_name_buf;
+      ret = parse_bracket_element (&start_elem, regexp, token, token_len, dfa,
+				   syntax, first_round);
+      if (BE (ret != REG_NOERROR, 0))
+	{
+	  *err = ret;
+	  goto parse_bracket_exp_free_return;
+	}
+      first_round = 0;
+
+      /* Get information about the next token.  We need it in any case.  */
+      token_len = peek_token_bracket (token, regexp, syntax);
+
+      /* Do not check for ranges if we know they are not allowed.  */
+      if (start_elem.type != CHAR_CLASS && start_elem.type != EQUIV_CLASS)
+	{
+	  if (BE (token->type == END_OF_RE, 0))
+	    {
+	      *err = REG_EBRACK;
+	      goto parse_bracket_exp_free_return;
+	    }
+	  if (token->type == OP_CHARSET_RANGE)
+	    {
+	      re_string_skip_bytes (regexp, token_len); /* Skip '-'.  */
+	      token_len2 = peek_token_bracket (&token2, regexp, syntax);
+	      if (BE (token2.type == END_OF_RE, 0))
+		{
+		  *err = REG_EBRACK;
+		  goto parse_bracket_exp_free_return;
+		}
+	      if (token2.type == OP_CLOSE_BRACKET)
+		{
+		  /* We treat the last '-' as a normal character.  */
+		  re_string_skip_bytes (regexp, -token_len);
+		  token->type = CHARACTER;
+		}
+	      else
+		is_range_exp = 1;
+	    }
+	}
+
+      if (is_range_exp == 1)
+	{
+	  end_elem.opr.name = end_name_buf;
+	  ret = parse_bracket_element (&end_elem, regexp, &token2, token_len2,
+				       dfa, syntax, 1);
+	  if (BE (ret != REG_NOERROR, 0))
+	    {
+	      *err = ret;
+	      goto parse_bracket_exp_free_return;
+	    }
+
+	  token_len = peek_token_bracket (token, regexp, syntax);
+
+#ifdef _LIBC
+	  *err = build_range_exp (sbcset, mbcset, &range_alloc,
+				  &start_elem, &end_elem);
+#else
+# ifdef RE_ENABLE_I18N
+	  *err = build_range_exp (sbcset,
+				  dfa->mb_cur_max > 1 ? mbcset : NULL,
+				  &range_alloc, &start_elem, &end_elem);
+# else
+	  *err = build_range_exp (sbcset, &start_elem, &end_elem);
+# endif
+#endif /* RE_ENABLE_I18N */
+	  if (BE (*err != REG_NOERROR, 0))
+	    goto parse_bracket_exp_free_return;
+	}
+      else
+	{
+	  switch (start_elem.type)
+	    {
+	    case SB_CHAR:
+	      bitset_set (sbcset, start_elem.opr.ch);
+	      break;
+#ifdef RE_ENABLE_I18N
+	    case MB_CHAR:
+	      /* Check whether the array has enough space.  */
+	      if (BE (mbchar_alloc == mbcset->nmbchars, 0))
+		{
+		  wchar_t *new_mbchars;
+		  /* Not enough, realloc it.  */
+		  /* +1 in case of mbcset->nmbchars is 0.  */
+		  mbchar_alloc = 2 * mbcset->nmbchars + 1;
+		  /* Use realloc since array is NULL if *alloc == 0.  */
+		  new_mbchars = re_realloc (mbcset->mbchars, wchar_t,
+					    mbchar_alloc);
+		  if (BE (new_mbchars == NULL, 0))
+		    goto parse_bracket_exp_espace;
+		  mbcset->mbchars = new_mbchars;
+		}
+	      mbcset->mbchars[mbcset->nmbchars++] = start_elem.opr.wch;
+	      break;
+#endif /* RE_ENABLE_I18N */
+	    case EQUIV_CLASS:
+	      *err = build_equiv_class (sbcset,
+#ifdef RE_ENABLE_I18N
+					mbcset, &equiv_class_alloc,
+#endif /* RE_ENABLE_I18N */
+					start_elem.opr.name);
+	      if (BE (*err != REG_NOERROR, 0))
+		goto parse_bracket_exp_free_return;
+	      break;
+	    case COLL_SYM:
+	      *err = build_collating_symbol (sbcset,
+#ifdef RE_ENABLE_I18N
+					     mbcset, &coll_sym_alloc,
+#endif /* RE_ENABLE_I18N */
+					     start_elem.opr.name);
+	      if (BE (*err != REG_NOERROR, 0))
+		goto parse_bracket_exp_free_return;
+	      break;
+	    case CHAR_CLASS:
+	      *err = build_charclass (regexp->trans, sbcset,
+#ifdef RE_ENABLE_I18N
+				      mbcset, &char_class_alloc,
+#endif /* RE_ENABLE_I18N */
+				      (const char *) start_elem.opr.name, syntax);
+	      if (BE (*err != REG_NOERROR, 0))
+	       goto parse_bracket_exp_free_return;
+	      break;
+	    default:
+	      assert (0);
+	      break;
+	    }
+	}
+      if (BE (token->type == END_OF_RE, 0))
+	{
+	  *err = REG_EBRACK;
+	  goto parse_bracket_exp_free_return;
+	}
+      if (token->type == OP_CLOSE_BRACKET)
+	break;
+    }
+
+  re_string_skip_bytes (regexp, token_len); /* Skip a token.  */
+
+  /* If it is non-matching list.  */
+  if (non_match)
+    bitset_not (sbcset);
+
+#ifdef RE_ENABLE_I18N
+  /* Ensure only single byte characters are set.  */
+  if (dfa->mb_cur_max > 1)
+    bitset_mask (sbcset, dfa->sb_char);
+
+  if (mbcset->nmbchars || mbcset->ncoll_syms || mbcset->nequiv_classes
+      || mbcset->nranges || (dfa->mb_cur_max > 1 && (mbcset->nchar_classes
+						     || mbcset->non_match)))
+    {
+      bin_tree_t *mbc_tree;
+      int sbc_idx;
+      /* Build a tree for complex bracket.  */
+      dfa->has_mb_node = 1;
+      br_token.type = COMPLEX_BRACKET;
+      br_token.opr.mbcset = mbcset;
+      mbc_tree = create_token_tree (dfa, NULL, NULL, &br_token);
+      if (BE (mbc_tree == NULL, 0))
+	goto parse_bracket_exp_espace;
+      for (sbc_idx = 0; sbc_idx < BITSET_WORDS; ++sbc_idx)
+	if (sbcset[sbc_idx])
+	  break;
+      /* If there are no bits set in sbcset, there is no point
+	 of having both SIMPLE_BRACKET and COMPLEX_BRACKET.  */
+      if (sbc_idx < BITSET_WORDS)
+	{
+	  /* Build a tree for simple bracket.  */
+	  br_token.type = SIMPLE_BRACKET;
+	  br_token.opr.sbcset = sbcset;
+	  work_tree = create_token_tree (dfa, NULL, NULL, &br_token);
+	  if (BE (work_tree == NULL, 0))
+	    goto parse_bracket_exp_espace;
+
+	  /* Then join them by ALT node.  */
+	  work_tree = create_tree (dfa, work_tree, mbc_tree, OP_ALT);
+	  if (BE (work_tree == NULL, 0))
+	    goto parse_bracket_exp_espace;
+	}
+      else
+	{
+	  re_free (sbcset);
+	  work_tree = mbc_tree;
+	}
+    }
+  else
+#endif /* not RE_ENABLE_I18N */
+    {
+#ifdef RE_ENABLE_I18N
+      free_charset (mbcset);
+#endif
+      /* Build a tree for simple bracket.  */
+      br_token.type = SIMPLE_BRACKET;
+      br_token.opr.sbcset = sbcset;
+      work_tree = create_token_tree (dfa, NULL, NULL, &br_token);
+      if (BE (work_tree == NULL, 0))
+	goto parse_bracket_exp_espace;
+    }
+  return work_tree;
+
+ parse_bracket_exp_espace:
+  *err = REG_ESPACE;
+ parse_bracket_exp_free_return:
+  re_free (sbcset);
+#ifdef RE_ENABLE_I18N
+  free_charset (mbcset);
+#endif /* RE_ENABLE_I18N */
+  return NULL;
+}
+
+/* Parse an element in the bracket expression.  */
+
+static reg_errcode_t
+parse_bracket_element (bracket_elem_t *elem, re_string_t *regexp,
+		       re_token_t *token, int token_len, UNUSED re_dfa_t *dfa,
+		       reg_syntax_t syntax, int accept_hyphen)
+{
+#ifdef RE_ENABLE_I18N
+  int cur_char_size;
+  cur_char_size = re_string_char_size_at (regexp, re_string_cur_idx (regexp));
+  if (cur_char_size > 1)
+    {
+      elem->type = MB_CHAR;
+      elem->opr.wch = re_string_wchar_at (regexp, re_string_cur_idx (regexp));
+      re_string_skip_bytes (regexp, cur_char_size);
+      return REG_NOERROR;
+    }
+#endif /* RE_ENABLE_I18N */
+  re_string_skip_bytes (regexp, token_len); /* Skip a token.  */
+  if (token->type == OP_OPEN_COLL_ELEM || token->type == OP_OPEN_CHAR_CLASS
+      || token->type == OP_OPEN_EQUIV_CLASS)
+    return parse_bracket_symbol (elem, regexp, token);
+  if (BE (token->type == OP_CHARSET_RANGE, 0) && !accept_hyphen)
+    {
+      /* A '-' must only appear as anything but a range indicator before
+	 the closing bracket.  Everything else is an error.  */
+      re_token_t token2;
+      (void) peek_token_bracket (&token2, regexp, syntax);
+      if (token2.type != OP_CLOSE_BRACKET)
+	/* The actual error value is not standardized since this whole
+	   case is undefined.  But ERANGE makes good sense.  */
+	return REG_ERANGE;
+    }
+  elem->type = SB_CHAR;
+  elem->opr.ch = token->opr.c;
+  return REG_NOERROR;
+}
+
+/* Parse a bracket symbol in the bracket expression.  Bracket symbols are
+   such as [:<character_class>:], [.<collating_element>.], and
+   [=<equivalent_class>=].  */
+
+static reg_errcode_t
+parse_bracket_symbol (bracket_elem_t *elem, re_string_t *regexp,
+		      re_token_t *token)
+{
+  unsigned char ch, delim = token->opr.c;
+  int i = 0;
+  if (re_string_eoi(regexp))
+    return REG_EBRACK;
+  for (;; ++i)
+    {
+      if (i >= BRACKET_NAME_BUF_SIZE)
+	return REG_EBRACK;
+      if (token->type == OP_OPEN_CHAR_CLASS)
+	ch = re_string_fetch_byte_case (regexp);
+      else
+	ch = re_string_fetch_byte (regexp);
+      if (re_string_eoi(regexp))
+	return REG_EBRACK;
+      if (ch == delim && re_string_peek_byte (regexp, 0) == ']')
+	break;
+      elem->opr.name[i] = ch;
+    }
+  re_string_skip_bytes (regexp, 1);
+  elem->opr.name[i] = '\0';
+  switch (token->type)
+    {
+    case OP_OPEN_COLL_ELEM:
+      elem->type = COLL_SYM;
+      break;
+    case OP_OPEN_EQUIV_CLASS:
+      elem->type = EQUIV_CLASS;
+      break;
+    case OP_OPEN_CHAR_CLASS:
+      elem->type = CHAR_CLASS;
+      break;
+    default:
+      break;
+    }
+  return REG_NOERROR;
+}
+
+  /* Helper function for parse_bracket_exp.
+     Build the equivalence class which is represented by NAME.
+     The result are written to MBCSET and SBCSET.
+     EQUIV_CLASS_ALLOC is the allocated size of mbcset->equiv_classes,
+     is a pointer argument sinse we may update it.  */
+
+static reg_errcode_t
+#ifdef RE_ENABLE_I18N
+build_equiv_class (bitset_t sbcset, re_charset_t *mbcset,
+		   int *equiv_class_alloc, const unsigned char *name)
+#else /* not RE_ENABLE_I18N */
+build_equiv_class (bitset_t sbcset, const unsigned char *name)
+#endif /* not RE_ENABLE_I18N */
+{
+#ifdef _LIBC
+  uint32_t nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+  if (nrules != 0)
+    {
+      const int32_t *table, *indirect;
+      const unsigned char *weights, *extra, *cp;
+      unsigned char char_buf[2];
+      int32_t idx1, idx2;
+      unsigned int ch;
+      size_t len;
+      /* This #include defines a local function!  */
+# include <locale/weight.h>
+      /* Calculate the index for equivalence class.  */
+      cp = name;
+      table = (const int32_t *) _NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEMB);
+      weights = (const unsigned char *) _NL_CURRENT (LC_COLLATE,
+					       _NL_COLLATE_WEIGHTMB);
+      extra = (const unsigned char *) _NL_CURRENT (LC_COLLATE,
+						   _NL_COLLATE_EXTRAMB);
+      indirect = (const int32_t *) _NL_CURRENT (LC_COLLATE,
+						_NL_COLLATE_INDIRECTMB);
+      idx1 = findidx (&cp);
+      if (BE (idx1 == 0 || cp < name + strlen ((const char *) name), 0))
+	/* This isn't a valid character.  */
+	return REG_ECOLLATE;
+
+      /* Build single byte matcing table for this equivalence class.  */
+      char_buf[1] = (unsigned char) '\0';
+      len = weights[idx1 & 0xffffff];
+      for (ch = 0; ch < SBC_MAX; ++ch)
+	{
+	  char_buf[0] = ch;
+	  cp = char_buf;
+	  idx2 = findidx (&cp);
+/*
+	  idx2 = table[ch];
+*/
+	  if (idx2 == 0)
+	    /* This isn't a valid character.  */
+	    continue;
+	  /* Compare only if the length matches and the collation rule
+	     index is the same.  */
+	  if (len == weights[idx2 & 0xffffff] && (idx1 >> 24) == (idx2 >> 24))
+	    {
+	      int cnt = 0;
+
+	      while (cnt <= len &&
+		     weights[(idx1 & 0xffffff) + 1 + cnt]
+		     == weights[(idx2 & 0xffffff) + 1 + cnt])
+		++cnt;
+
+	      if (cnt > len)
+		bitset_set (sbcset, ch);
+	    }
+	}
+      /* Check whether the array has enough space.  */
+      if (BE (*equiv_class_alloc == mbcset->nequiv_classes, 0))
+	{
+	  /* Not enough, realloc it.  */
+	  /* +1 in case of mbcset->nequiv_classes is 0.  */
+	  int new_equiv_class_alloc = 2 * mbcset->nequiv_classes + 1;
+	  /* Use realloc since the array is NULL if *alloc == 0.  */
+	  int32_t *new_equiv_classes = re_realloc (mbcset->equiv_classes,
+						   int32_t,
+						   new_equiv_class_alloc);
+	  if (BE (new_equiv_classes == NULL, 0))
+	    return REG_ESPACE;
+	  mbcset->equiv_classes = new_equiv_classes;
+	  *equiv_class_alloc = new_equiv_class_alloc;
+	}
+      mbcset->equiv_classes[mbcset->nequiv_classes++] = idx1;
+    }
+  else
+#endif /* _LIBC */
+    {
+      if (BE (strlen ((const char *) name) != 1, 0))
+	return REG_ECOLLATE;
+      bitset_set (sbcset, *name);
+    }
+  return REG_NOERROR;
+}
+
+  /* Helper function for parse_bracket_exp.
+     Build the character class which is represented by NAME.
+     The result are written to MBCSET and SBCSET.
+     CHAR_CLASS_ALLOC is the allocated size of mbcset->char_classes,
+     is a pointer argument sinse we may update it.  */
+
+static reg_errcode_t
+#ifdef RE_ENABLE_I18N
+build_charclass (RE_TRANSLATE_TYPE trans, bitset_t sbcset,
+		 re_charset_t *mbcset, int *char_class_alloc,
+		 const char *class_name, reg_syntax_t syntax)
+#else /* not RE_ENABLE_I18N */
+build_charclass (RE_TRANSLATE_TYPE trans, bitset_t sbcset,
+		 const char *class_name, reg_syntax_t syntax)
+#endif /* not RE_ENABLE_I18N */
+{
+  int i;
+
+  /* In case of REG_ICASE "upper" and "lower" match the both of
+     upper and lower cases.  */
+  if ((syntax & RE_ICASE)
+      && (strcmp (class_name, "upper") == 0 || strcmp (class_name, "lower") == 0))
+    class_name = "alpha";
+
+#ifdef RE_ENABLE_I18N
+  /* Check the space of the arrays.  */
+  if (BE (*char_class_alloc == mbcset->nchar_classes, 0))
+    {
+      /* Not enough, realloc it.  */
+      /* +1 in case of mbcset->nchar_classes is 0.  */
+      int new_char_class_alloc = 2 * mbcset->nchar_classes + 1;
+      /* Use realloc since array is NULL if *alloc == 0.  */
+      wctype_t *new_char_classes = re_realloc (mbcset->char_classes, wctype_t,
+					       new_char_class_alloc);
+      if (BE (new_char_classes == NULL, 0))
+	return REG_ESPACE;
+      mbcset->char_classes = new_char_classes;
+      *char_class_alloc = new_char_class_alloc;
+    }
+  mbcset->char_classes[mbcset->nchar_classes++] = __wctype (class_name);
+#endif /* RE_ENABLE_I18N */
+
+#define BUILD_CHARCLASS_LOOP(ctype_func)	\
+  do {						\
+    if (BE (trans != NULL, 0))			\
+      {						\
+	for (i = 0; i < SBC_MAX; ++i)		\
+  	  if (ctype_func (i))			\
+	    bitset_set (sbcset, trans[i]);	\
+      }						\
+    else					\
+      {						\
+	for (i = 0; i < SBC_MAX; ++i)		\
+  	  if (ctype_func (i))			\
+	    bitset_set (sbcset, i);		\
+      }						\
+  } while (0)
+
+  if (strcmp (class_name, "alnum") == 0)
+    BUILD_CHARCLASS_LOOP (isalnum);
+  else if (strcmp (class_name, "cntrl") == 0)
+    BUILD_CHARCLASS_LOOP (iscntrl);
+  else if (strcmp (class_name, "lower") == 0)
+    BUILD_CHARCLASS_LOOP (islower);
+  else if (strcmp (class_name, "space") == 0)
+    BUILD_CHARCLASS_LOOP (isspace);
+  else if (strcmp (class_name, "alpha") == 0)
+    BUILD_CHARCLASS_LOOP (isalpha);
+  else if (strcmp (class_name, "digit") == 0)
+    BUILD_CHARCLASS_LOOP (isdigit);
+  else if (strcmp (class_name, "print") == 0)
+    BUILD_CHARCLASS_LOOP (isprint);
+  else if (strcmp (class_name, "upper") == 0)
+    BUILD_CHARCLASS_LOOP (isupper);
+  else if (strcmp (class_name, "blank") == 0)
+#ifndef GAWK
+    BUILD_CHARCLASS_LOOP (isblank);
+#else
+    /* see comments above */
+    BUILD_CHARCLASS_LOOP (is_blank);
+#endif
+  else if (strcmp (class_name, "graph") == 0)
+    BUILD_CHARCLASS_LOOP (isgraph);
+  else if (strcmp (class_name, "punct") == 0)
+    BUILD_CHARCLASS_LOOP (ispunct);
+  else if (strcmp (class_name, "xdigit") == 0)
+    BUILD_CHARCLASS_LOOP (isxdigit);
+  else
+    return REG_ECTYPE;
+
+  return REG_NOERROR;
+}
+
+static bin_tree_t *
+build_charclass_op (re_dfa_t *dfa, RE_TRANSLATE_TYPE trans,
+		    const char *class_name,
+		    const char *extra, int non_match,
+		    reg_errcode_t *err)
+{
+  re_bitset_ptr_t sbcset;
+#ifdef RE_ENABLE_I18N
+  re_charset_t *mbcset;
+  int alloc = 0;
+#endif /* not RE_ENABLE_I18N */
+  reg_errcode_t ret;
+  re_token_t br_token;
+  bin_tree_t *tree;
+
+  sbcset = (re_bitset_ptr_t) calloc (sizeof (bitset_t), 1);
+#ifdef RE_ENABLE_I18N
+  mbcset = (re_charset_t *) calloc (sizeof (re_charset_t), 1);
+#endif /* RE_ENABLE_I18N */
+
+#ifdef RE_ENABLE_I18N
+  if (BE (sbcset == NULL || mbcset == NULL, 0))
+#else /* not RE_ENABLE_I18N */
+  if (BE (sbcset == NULL, 0))
+#endif /* not RE_ENABLE_I18N */
+    {
+      *err = REG_ESPACE;
+      return NULL;
+    }
+
+  if (non_match)
+    {
+#ifdef RE_ENABLE_I18N
+      mbcset->non_match = 1;
+#endif /* not RE_ENABLE_I18N */
+    }
+
+  /* We don't care the syntax in this case.  */
+  ret = build_charclass (trans, sbcset,
+#ifdef RE_ENABLE_I18N
+			 mbcset, &alloc,
+#endif /* RE_ENABLE_I18N */
+			 class_name, 0);
+
+  if (BE (ret != REG_NOERROR, 0))
+    {
+      re_free (sbcset);
+#ifdef RE_ENABLE_I18N
+      free_charset (mbcset);
+#endif /* RE_ENABLE_I18N */
+      *err = ret;
+      return NULL;
+    }
+  /* \w match '_' also.  */
+  for (; *extra; extra++)
+    bitset_set (sbcset, *extra);
+
+  /* If it is non-matching list.  */
+  if (non_match)
+    bitset_not (sbcset);
+
+#ifdef RE_ENABLE_I18N
+  /* Ensure only single byte characters are set.  */
+  if (dfa->mb_cur_max > 1)
+    bitset_mask (sbcset, dfa->sb_char);
+#endif
+
+  /* Build a tree for simple bracket.  */
+  br_token.type = SIMPLE_BRACKET;
+  br_token.opr.sbcset = sbcset;
+  tree = create_token_tree (dfa, NULL, NULL, &br_token);
+  if (BE (tree == NULL, 0))
+    goto build_word_op_espace;
+
+#ifdef RE_ENABLE_I18N
+  if (dfa->mb_cur_max > 1)
+    {
+      bin_tree_t *mbc_tree;
+      /* Build a tree for complex bracket.  */
+      br_token.type = COMPLEX_BRACKET;
+      br_token.opr.mbcset = mbcset;
+      dfa->has_mb_node = 1;
+      mbc_tree = create_token_tree (dfa, NULL, NULL, &br_token);
+      if (BE (mbc_tree == NULL, 0))
+	goto build_word_op_espace;
+      /* Then join them by ALT node.  */
+      tree = create_tree (dfa, tree, mbc_tree, OP_ALT);
+      if (BE (mbc_tree != NULL, 1))
+	return tree;
+    }
+  else
+    {
+      free_charset (mbcset);
+      return tree;
+    }
+#else /* not RE_ENABLE_I18N */
+  return tree;
+#endif /* not RE_ENABLE_I18N */
+
+ build_word_op_espace:
+  re_free (sbcset);
+#ifdef RE_ENABLE_I18N
+  free_charset (mbcset);
+#endif /* RE_ENABLE_I18N */
+  *err = REG_ESPACE;
+  return NULL;
+}
+
+/* This is intended for the expressions like "a{1,3}".
+   Fetch a number from `input', and return the number.
+   Return -1, if the number field is empty like "{,1}".
+   Return -2, If an error is occured.  */
+
+static int
+fetch_number (re_string_t *input, re_token_t *token, reg_syntax_t syntax)
+{
+  int num = -1;
+  unsigned char c;
+  while (1)
+    {
+      fetch_token (token, input, syntax);
+      c = token->opr.c;
+      if (BE (token->type == END_OF_RE, 0))
+	return -2;
+      if (token->type == OP_CLOSE_DUP_NUM || c == ',')
+	break;
+      num = ((token->type != CHARACTER || c < '0' || '9' < c || num == -2)
+	     ? -2 : ((num == -1) ? c - '0' : num * 10 + c - '0'));
+      num = (num > RE_DUP_MAX) ? -2 : num;
+    }
+  return num;
+}
+
+#ifdef RE_ENABLE_I18N
+static void
+free_charset (re_charset_t *cset)
+{
+  re_free (cset->mbchars);
+# ifdef _LIBC
+  re_free (cset->coll_syms);
+  re_free (cset->equiv_classes);
+  re_free (cset->range_starts);
+  re_free (cset->range_ends);
+# endif
+  re_free (cset->char_classes);
+  re_free (cset);
+}
+#endif /* RE_ENABLE_I18N */
+
+/* Functions for binary tree operation.  */
+
+/* Create a tree node.  */
+
+static bin_tree_t *
+create_tree (re_dfa_t *dfa, bin_tree_t *left, bin_tree_t *right,
+	     re_token_type_t type)
+{
+  re_token_t t;
+  t.type = type;
+  return create_token_tree (dfa, left, right, &t);
+}
+
+static bin_tree_t *
+create_token_tree (re_dfa_t *dfa, bin_tree_t *left, bin_tree_t *right,
+		   const re_token_t *token)
+{
+  bin_tree_t *tree;
+  if (BE (dfa->str_tree_storage_idx == BIN_TREE_STORAGE_SIZE, 0))
+    {
+      bin_tree_storage_t *storage = re_malloc (bin_tree_storage_t, 1);
+
+      if (storage == NULL)
+	return NULL;
+      storage->next = dfa->str_tree_storage;
+      dfa->str_tree_storage = storage;
+      dfa->str_tree_storage_idx = 0;
+    }
+  tree = &dfa->str_tree_storage->data[dfa->str_tree_storage_idx++];
+
+  tree->parent = NULL;
+  tree->left = left;
+  tree->right = right;
+  tree->token = *token;
+  tree->token.duplicated = 0;
+  tree->token.opt_subexp = 0;
+  tree->first = NULL;
+  tree->next = NULL;
+  tree->node_idx = -1;
+
+  if (left != NULL)
+    left->parent = tree;
+  if (right != NULL)
+    right->parent = tree;
+  return tree;
+}
+
+/* Mark the tree SRC as an optional subexpression.
+   To be called from preorder or postorder.  */
+
+static reg_errcode_t
+mark_opt_subexp (void *extra, bin_tree_t *node)
+{
+  int idx = (int) (long) extra;
+  if (node->token.type == SUBEXP && node->token.opr.idx == idx)
+    node->token.opt_subexp = 1;
+
+  return REG_NOERROR;
+}
+
+/* Free the allocated memory inside NODE. */
+
+static void
+free_token (re_token_t *node)
+{
+#ifdef RE_ENABLE_I18N
+  if (node->type == COMPLEX_BRACKET && node->duplicated == 0)
+    free_charset (node->opr.mbcset);
+  else
+#endif /* RE_ENABLE_I18N */
+    if (node->type == SIMPLE_BRACKET && node->duplicated == 0)
+      re_free (node->opr.sbcset);
+}
+
+/* Worker function for tree walking.  Free the allocated memory inside NODE
+   and its children. */
+
+static reg_errcode_t
+free_tree (UNUSED void *extra, bin_tree_t *node)
+{
+  free_token (&node->token);
+  return REG_NOERROR;
+}
+
+
+/* Duplicate the node SRC, and return new node.  This is a preorder
+   visit similar to the one implemented by the generic visitor, but
+   we need more infrastructure to maintain two parallel trees --- so,
+   it's easier to duplicate.  */
+
+static bin_tree_t *
+duplicate_tree (const bin_tree_t *root, re_dfa_t *dfa)
+{
+  const bin_tree_t *node;
+  bin_tree_t *dup_root;
+  bin_tree_t **p_new = &dup_root, *dup_node = root->parent;
+
+  for (node = root; ; )
+    {
+      /* Create a new tree and link it back to the current parent.  */
+      *p_new = create_token_tree (dfa, NULL, NULL, &node->token);
+      if (*p_new == NULL)
+	return NULL;
+      (*p_new)->parent = dup_node;
+      (*p_new)->token.duplicated = 1;
+      dup_node = *p_new;
+
+      /* Go to the left node, or up and to the right.  */
+      if (node->left)
+	{
+	  node = node->left;
+	  p_new = &dup_node->left;
+	}
+      else
+	{
+	  const bin_tree_t *prev = NULL;
+	  while (node->right == prev || node->right == NULL)
+	    {
+	      prev = node;
+	      node = node->parent;
+	      dup_node = dup_node->parent;
+	      if (!node)
+		return dup_root;
+	    }
+	  node = node->right;
+	  p_new = &dup_node->right;
+	}
+    }
+}

vendor/libgit2-sys/libgit2/deps/regex/regex.c

diff --git a/vendor/libgit2-sys/libgit2/deps/regex/regex.c b/vendor/libgit2-sys/libgit2/deps/regex/regex.c
new file mode 100644
index 0000000..225a001
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/regex/regex.c
@@ -0,0 +1,92 @@
+/* Extended regular expression matching and search library.
+   Copyright (C) 2002, 2003, 2005 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301 USA.  */
+
+#include "config.h"
+
+/* Make sure noone compiles this code with a C++ compiler.  */
+#ifdef __cplusplus
+# error "This is C code, use a C compiler"
+#endif
+
+#ifdef _LIBC
+/* We have to keep the namespace clean.  */
+# define regfree(preg) __regfree (preg)
+# define regexec(pr, st, nm, pm, ef) __regexec (pr, st, nm, pm, ef)
+# define regcomp(preg, pattern, cflags) __regcomp (preg, pattern, cflags)
+# define regerror(errcode, preg, errbuf, errbuf_size) \
+	__regerror(errcode, preg, errbuf, errbuf_size)
+# define re_set_registers(bu, re, nu, st, en) \
+	__re_set_registers (bu, re, nu, st, en)
+# define re_match_2(bufp, string1, size1, string2, size2, pos, regs, stop) \
+	__re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
+# define re_match(bufp, string, size, pos, regs) \
+	__re_match (bufp, string, size, pos, regs)
+# define re_search(bufp, string, size, startpos, range, regs) \
+	__re_search (bufp, string, size, startpos, range, regs)
+# define re_compile_pattern(pattern, length, bufp) \
+	__re_compile_pattern (pattern, length, bufp)
+# define re_set_syntax(syntax) __re_set_syntax (syntax)
+# define re_search_2(bufp, st1, s1, st2, s2, startpos, range, regs, stop) \
+	__re_search_2 (bufp, st1, s1, st2, s2, startpos, range, regs, stop)
+# define re_compile_fastmap(bufp) __re_compile_fastmap (bufp)
+
+# include "../locale/localeinfo.h"
+#endif
+
+#if defined (_MSC_VER)
+#include <stdio.h> /* for size_t */
+#endif
+
+/* On some systems, limits.h sets RE_DUP_MAX to a lower value than
+   GNU regex allows.  Include it before <regex.h>, which correctly
+   #undefs RE_DUP_MAX and sets it to the right value.  */
+#include <limits.h>
+
+#ifdef GAWK
+#undef alloca
+#define alloca alloca_is_bad_you_should_never_use_it
+#endif
+#include <regex.h>
+#include "regex_internal.h"
+
+#include "regex_internal.c"
+
+#ifdef GAWK
+# define bool int
+
+# ifndef true
+#  define true (1)
+# endif
+
+# ifndef false
+#  define false (0)
+# endif
+#endif
+#include "regcomp.c"
+#include "regexec.c"
+
+/* Binary backward compatibility.  */
+#if _LIBC
+# include <shlib-compat.h>
+# if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_3)
+link_warning (re_max_failures, "the 're_max_failures' variable is obsolete and will go away.")
+int re_max_failures = 2000;
+# endif
+#endif

vendor/libgit2-sys/libgit2/deps/regex/regex.h

diff --git a/vendor/libgit2-sys/libgit2/deps/regex/regex.h b/vendor/libgit2-sys/libgit2/deps/regex/regex.h
new file mode 100644
index 0000000..61c9683
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/regex/regex.h
@@ -0,0 +1,582 @@
+#include <stdio.h>
+#include <stddef.h>
+
+/* Definitions for data structures and routines for the regular
+   expression library.
+   Copyright (C) 1985,1989-93,1995-98,2000,2001,2002,2003,2005,2006,2008
+   Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301 USA.  */
+
+#ifndef _REGEX_H
+#define _REGEX_H 1
+
+#ifdef HAVE_STDDEF_H
+#include <stddef.h>
+#endif
+
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+
+#ifndef _LIBC
+#define __USE_GNU	1
+#endif
+
+/* Allow the use in C++ code.  */
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* The following two types have to be signed and unsigned integer type
+   wide enough to hold a value of a pointer.  For most ANSI compilers
+   ptrdiff_t and size_t should be likely OK.  Still size of these two
+   types is 2 for Microsoft C.  Ugh... */
+typedef long int s_reg_t;
+typedef unsigned long int active_reg_t;
+
+/* The following bits are used to determine the regexp syntax we
+   recognize.  The set/not-set meanings are chosen so that Emacs syntax
+   remains the value 0.  The bits are given in alphabetical order, and
+   the definitions shifted by one from the previous bit; thus, when we
+   add or remove a bit, only one other definition need change.  */
+typedef unsigned long int reg_syntax_t;
+
+#ifdef __USE_GNU
+/* If this bit is not set, then \ inside a bracket expression is literal.
+   If set, then such a \ quotes the following character.  */
+# define RE_BACKSLASH_ESCAPE_IN_LISTS ((unsigned long int) 1)
+
+/* If this bit is not set, then + and ? are operators, and \+ and \? are
+     literals.
+   If set, then \+ and \? are operators and + and ? are literals.  */
+# define RE_BK_PLUS_QM (RE_BACKSLASH_ESCAPE_IN_LISTS << 1)
+
+/* If this bit is set, then character classes are supported.  They are:
+     [:alpha:], [:upper:], [:lower:],  [:digit:], [:alnum:], [:xdigit:],
+     [:space:], [:print:], [:punct:], [:graph:], and [:cntrl:].
+   If not set, then character classes are not supported.  */
+# define RE_CHAR_CLASSES (RE_BK_PLUS_QM << 1)
+
+/* If this bit is set, then ^ and $ are always anchors (outside bracket
+     expressions, of course).
+   If this bit is not set, then it depends:
+        ^  is an anchor if it is at the beginning of a regular
+           expression or after an open-group or an alternation operator;
+        $  is an anchor if it is at the end of a regular expression, or
+           before a close-group or an alternation operator.
+
+   This bit could be (re)combined with RE_CONTEXT_INDEP_OPS, because
+   POSIX draft 11.2 says that * etc. in leading positions is undefined.
+   We already implemented a previous draft which made those constructs
+   invalid, though, so we haven't changed the code back.  */
+# define RE_CONTEXT_INDEP_ANCHORS (RE_CHAR_CLASSES << 1)
+
+/* If this bit is set, then special characters are always special
+     regardless of where they are in the pattern.
+   If this bit is not set, then special characters are special only in
+     some contexts; otherwise they are ordinary.  Specifically,
+     * + ? and intervals are only special when not after the beginning,
+     open-group, or alternation operator.  */
+# define RE_CONTEXT_INDEP_OPS (RE_CONTEXT_INDEP_ANCHORS << 1)
+
+/* If this bit is set, then *, +, ?, and { cannot be first in an re or
+     immediately after an alternation or begin-group operator.  */
+# define RE_CONTEXT_INVALID_OPS (RE_CONTEXT_INDEP_OPS << 1)
+
+/* If this bit is set, then . matches newline.
+   If not set, then it doesn't.  */
+# define RE_DOT_NEWLINE (RE_CONTEXT_INVALID_OPS << 1)
+
+/* If this bit is set, then . doesn't match NUL.
+   If not set, then it does.  */
+# define RE_DOT_NOT_NULL (RE_DOT_NEWLINE << 1)
+
+/* If this bit is set, nonmatching lists [^...] do not match newline.
+   If not set, they do.  */
+# define RE_HAT_LISTS_NOT_NEWLINE (RE_DOT_NOT_NULL << 1)
+
+/* If this bit is set, either \{...\} or {...} defines an
+     interval, depending on RE_NO_BK_BRACES.
+   If not set, \{, \}, {, and } are literals.  */
+# define RE_INTERVALS (RE_HAT_LISTS_NOT_NEWLINE << 1)
+
+/* If this bit is set, +, ? and | aren't recognized as operators.
+   If not set, they are.  */
+# define RE_LIMITED_OPS (RE_INTERVALS << 1)
+
+/* If this bit is set, newline is an alternation operator.
+   If not set, newline is literal.  */
+# define RE_NEWLINE_ALT (RE_LIMITED_OPS << 1)
+
+/* If this bit is set, then `{...}' defines an interval, and \{ and \}
+     are literals.
+  If not set, then `\{...\}' defines an interval.  */
+# define RE_NO_BK_BRACES (RE_NEWLINE_ALT << 1)
+
+/* If this bit is set, (...) defines a group, and \( and \) are literals.
+   If not set, \(...\) defines a group, and ( and ) are literals.  */
+# define RE_NO_BK_PARENS (RE_NO_BK_BRACES << 1)
+
+/* If this bit is set, then \<digit> matches <digit>.
+   If not set, then \<digit> is a back-reference.  */
+# define RE_NO_BK_REFS (RE_NO_BK_PARENS << 1)
+
+/* If this bit is set, then | is an alternation operator, and \| is literal.
+   If not set, then \| is an alternation operator, and | is literal.  */
+# define RE_NO_BK_VBAR (RE_NO_BK_REFS << 1)
+
+/* If this bit is set, then an ending range point collating higher
+     than the starting range point, as in [z-a], is invalid.
+   If not set, then when ending range point collates higher than the
+     starting range point, the range is ignored.  */
+# define RE_NO_EMPTY_RANGES (RE_NO_BK_VBAR << 1)
+
+/* If this bit is set, then an unmatched ) is ordinary.
+   If not set, then an unmatched ) is invalid.  */
+# define RE_UNMATCHED_RIGHT_PAREN_ORD (RE_NO_EMPTY_RANGES << 1)
+
+/* If this bit is set, succeed as soon as we match the whole pattern,
+   without further backtracking.  */
+# define RE_NO_POSIX_BACKTRACKING (RE_UNMATCHED_RIGHT_PAREN_ORD << 1)
+
+/* If this bit is set, do not process the GNU regex operators.
+   If not set, then the GNU regex operators are recognized. */
+# define RE_NO_GNU_OPS (RE_NO_POSIX_BACKTRACKING << 1)
+
+/* If this bit is set, a syntactically invalid interval is treated as
+   a string of ordinary characters.  For example, the ERE 'a{1' is
+   treated as 'a\{1'.  */
+# define RE_INVALID_INTERVAL_ORD (RE_NO_GNU_OPS << 1)
+
+/* If this bit is set, then ignore case when matching.
+   If not set, then case is significant.  */
+# define RE_ICASE (RE_INVALID_INTERVAL_ORD << 1)
+
+/* This bit is used internally like RE_CONTEXT_INDEP_ANCHORS but only
+   for ^, because it is difficult to scan the regex backwards to find
+   whether ^ should be special.  */
+# define RE_CARET_ANCHORS_HERE (RE_ICASE << 1)
+
+/* If this bit is set, then \{ cannot be first in an bre or
+   immediately after an alternation or begin-group operator.  */
+# define RE_CONTEXT_INVALID_DUP (RE_CARET_ANCHORS_HERE << 1)
+
+/* If this bit is set, then no_sub will be set to 1 during
+   re_compile_pattern.  */
+#define RE_NO_SUB (RE_CONTEXT_INVALID_DUP << 1)
+#endif
+
+/* This global variable defines the particular regexp syntax to use (for
+   some interfaces).  When a regexp is compiled, the syntax used is
+   stored in the pattern buffer, so changing this does not affect
+   already-compiled regexps.  */
+extern reg_syntax_t re_syntax_options;
+
+#ifdef __USE_GNU
+/* Define combinations of the above bits for the standard possibilities.
+   (The [[[ comments delimit what gets put into the Texinfo file, so
+   don't delete them!)  */
+/* [[[begin syntaxes]]] */
+#define RE_SYNTAX_EMACS 0
+
+#define RE_SYNTAX_AWK							\
+  (RE_BACKSLASH_ESCAPE_IN_LISTS   | RE_DOT_NOT_NULL			\
+   | RE_NO_BK_PARENS              | RE_NO_BK_REFS			\
+   | RE_NO_BK_VBAR                | RE_NO_EMPTY_RANGES			\
+   | RE_DOT_NEWLINE		  | RE_CONTEXT_INDEP_ANCHORS		\
+   | RE_UNMATCHED_RIGHT_PAREN_ORD | RE_NO_GNU_OPS)
+
+#define RE_SYNTAX_GNU_AWK						\
+  ((RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS		\
+   | RE_INVALID_INTERVAL_ORD)						\
+   & ~(RE_DOT_NOT_NULL | RE_CONTEXT_INDEP_OPS				\
+       | RE_CONTEXT_INVALID_OPS ))
+
+#define RE_SYNTAX_POSIX_AWK						\
+  (RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS		\
+   | RE_INTERVALS	    | RE_NO_GNU_OPS				\
+   | RE_INVALID_INTERVAL_ORD)
+
+#define RE_SYNTAX_GREP							\
+  (RE_BK_PLUS_QM              | RE_CHAR_CLASSES				\
+   | RE_HAT_LISTS_NOT_NEWLINE | RE_INTERVALS				\
+   | RE_NEWLINE_ALT)
+
+#define RE_SYNTAX_EGREP							\
+  (RE_CHAR_CLASSES        | RE_CONTEXT_INDEP_ANCHORS			\
+   | RE_CONTEXT_INDEP_OPS | RE_HAT_LISTS_NOT_NEWLINE			\
+   | RE_NEWLINE_ALT       | RE_NO_BK_PARENS				\
+   | RE_NO_BK_VBAR)
+
+#define RE_SYNTAX_POSIX_EGREP						\
+  (RE_SYNTAX_EGREP | RE_INTERVALS | RE_NO_BK_BRACES			\
+   | RE_INVALID_INTERVAL_ORD)
+
+/* P1003.2/D11.2, section 4.20.7.1, lines 5078ff.  */
+#define RE_SYNTAX_ED RE_SYNTAX_POSIX_BASIC
+
+#define RE_SYNTAX_SED RE_SYNTAX_POSIX_BASIC
+
+/* Syntax bits common to both basic and extended POSIX regex syntax.  */
+#define _RE_SYNTAX_POSIX_COMMON						\
+  (RE_CHAR_CLASSES | RE_DOT_NEWLINE      | RE_DOT_NOT_NULL		\
+   | RE_INTERVALS  | RE_NO_EMPTY_RANGES)
+
+#define RE_SYNTAX_POSIX_BASIC						\
+  (_RE_SYNTAX_POSIX_COMMON | RE_BK_PLUS_QM | RE_CONTEXT_INVALID_DUP)
+
+/* Differs from ..._POSIX_BASIC only in that RE_BK_PLUS_QM becomes
+   RE_LIMITED_OPS, i.e., \? \+ \| are not recognized.  Actually, this
+   isn't minimal, since other operators, such as \`, aren't disabled.  */
+#define RE_SYNTAX_POSIX_MINIMAL_BASIC					\
+  (_RE_SYNTAX_POSIX_COMMON | RE_LIMITED_OPS)
+
+#define RE_SYNTAX_POSIX_EXTENDED					\
+  (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS			\
+   | RE_CONTEXT_INDEP_OPS   | RE_NO_BK_BRACES				\
+   | RE_NO_BK_PARENS        | RE_NO_BK_VBAR				\
+   | RE_CONTEXT_INVALID_OPS | RE_UNMATCHED_RIGHT_PAREN_ORD)
+
+/* Differs from ..._POSIX_EXTENDED in that RE_CONTEXT_INDEP_OPS is
+   removed and RE_NO_BK_REFS is added.  */
+#define RE_SYNTAX_POSIX_MINIMAL_EXTENDED				\
+  (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS			\
+   | RE_CONTEXT_INVALID_OPS | RE_NO_BK_BRACES				\
+   | RE_NO_BK_PARENS        | RE_NO_BK_REFS				\
+   | RE_NO_BK_VBAR	    | RE_UNMATCHED_RIGHT_PAREN_ORD)
+/* [[[end syntaxes]]] */
+
+/* Maximum number of duplicates an interval can allow.  Some systems
+   (erroneously) define this in other header files, but we want our
+   value, so remove any previous define.  */
+# ifdef RE_DUP_MAX
+#  undef RE_DUP_MAX
+# endif
+/* If sizeof(int) == 2, then ((1 << 15) - 1) overflows.  */
+# define RE_DUP_MAX (0x7fff)
+#endif
+
+
+/* POSIX `cflags' bits (i.e., information for `regcomp').  */
+
+/* If this bit is set, then use extended regular expression syntax.
+   If not set, then use basic regular expression syntax.  */
+#define REG_EXTENDED 1
+
+/* If this bit is set, then ignore case when matching.
+   If not set, then case is significant.  */
+#define REG_ICASE (REG_EXTENDED << 1)
+
+/* If this bit is set, then anchors do not match at newline
+     characters in the string.
+   If not set, then anchors do match at newlines.  */
+#define REG_NEWLINE (REG_ICASE << 1)
+
+/* If this bit is set, then report only success or fail in regexec.
+   If not set, then returns differ between not matching and errors.  */
+#define REG_NOSUB (REG_NEWLINE << 1)
+
+
+/* POSIX `eflags' bits (i.e., information for regexec).  */
+
+/* If this bit is set, then the beginning-of-line operator doesn't match
+     the beginning of the string (presumably because it's not the
+     beginning of a line).
+   If not set, then the beginning-of-line operator does match the
+     beginning of the string.  */
+#define REG_NOTBOL 1
+
+/* Like REG_NOTBOL, except for the end-of-line.  */
+#define REG_NOTEOL (1 << 1)
+
+/* Use PMATCH[0] to delimit the start and end of the search in the
+   buffer.  */
+#define REG_STARTEND (1 << 2)
+
+
+/* If any error codes are removed, changed, or added, update the
+   `re_error_msg' table in regex.c.  */
+typedef enum
+{
+#if defined _XOPEN_SOURCE || defined __USE_XOPEN2K
+  REG_ENOSYS = -1,	/* This will never happen for this implementation.  */
+#endif
+
+  REG_NOERROR = 0,	/* Success.  */
+  REG_NOMATCH,		/* Didn't find a match (for regexec).  */
+
+  /* POSIX regcomp return error codes.  (In the order listed in the
+     standard.)  */
+  REG_BADPAT,		/* Invalid pattern.  */
+  REG_ECOLLATE,		/* Inalid collating element.  */
+  REG_ECTYPE,		/* Invalid character class name.  */
+  REG_EESCAPE,		/* Trailing backslash.  */
+  REG_ESUBREG,		/* Invalid back reference.  */
+  REG_EBRACK,		/* Unmatched left bracket.  */
+  REG_EPAREN,		/* Parenthesis imbalance.  */
+  REG_EBRACE,		/* Unmatched \{.  */
+  REG_BADBR,		/* Invalid contents of \{\}.  */
+  REG_ERANGE,		/* Invalid range end.  */
+  REG_ESPACE,		/* Ran out of memory.  */
+  REG_BADRPT,		/* No preceding re for repetition op.  */
+
+  /* Error codes we've added.  */
+  REG_EEND,		/* Premature end.  */
+  REG_ESIZE,		/* Compiled pattern bigger than 2^16 bytes.  */
+  REG_ERPAREN		/* Unmatched ) or \); not returned from regcomp.  */
+} reg_errcode_t;
+
+/* This data structure represents a compiled pattern.  Before calling
+   the pattern compiler, the fields `buffer', `allocated', `fastmap',
+   `translate', and `no_sub' can be set.  After the pattern has been
+   compiled, the `re_nsub' field is available.  All other fields are
+   private to the regex routines.  */
+
+#ifndef RE_TRANSLATE_TYPE
+# define __RE_TRANSLATE_TYPE unsigned char *
+# ifdef __USE_GNU
+#  define RE_TRANSLATE_TYPE __RE_TRANSLATE_TYPE
+# endif
+#endif
+
+#ifdef __USE_GNU
+# define __REPB_PREFIX(name) name
+#else
+# define __REPB_PREFIX(name) __##name
+#endif
+
+struct re_pattern_buffer
+{
+  /* Space that holds the compiled pattern.  It is declared as
+     `unsigned char *' because its elements are sometimes used as
+     array indexes.  */
+  unsigned char *__REPB_PREFIX(buffer);
+
+  /* Number of bytes to which `buffer' points.  */
+  unsigned long int __REPB_PREFIX(allocated);
+
+  /* Number of bytes actually used in `buffer'.  */
+  unsigned long int __REPB_PREFIX(used);
+
+  /* Syntax setting with which the pattern was compiled.  */
+  reg_syntax_t __REPB_PREFIX(syntax);
+
+  /* Pointer to a fastmap, if any, otherwise zero.  re_search uses the
+     fastmap, if there is one, to skip over impossible starting points
+     for matches.  */
+  char *__REPB_PREFIX(fastmap);
+
+  /* Either a translate table to apply to all characters before
+     comparing them, or zero for no translation.  The translation is
+     applied to a pattern when it is compiled and to a string when it
+     is matched.  */
+  __RE_TRANSLATE_TYPE __REPB_PREFIX(translate);
+
+  /* Number of subexpressions found by the compiler.  */
+  size_t re_nsub;
+
+  /* Zero if this pattern cannot match the empty string, one else.
+     Well, in truth it's used only in `re_search_2', to see whether or
+     not we should use the fastmap, so we don't set this absolutely
+     perfectly; see `re_compile_fastmap' (the `duplicate' case).  */
+  unsigned __REPB_PREFIX(can_be_null) : 1;
+
+  /* If REGS_UNALLOCATED, allocate space in the `regs' structure
+     for `max (RE_NREGS, re_nsub + 1)' groups.
+     If REGS_REALLOCATE, reallocate space if necessary.
+     If REGS_FIXED, use what's there.  */
+#ifdef __USE_GNU
+# define REGS_UNALLOCATED 0
+# define REGS_REALLOCATE 1
+# define REGS_FIXED 2
+#endif
+  unsigned __REPB_PREFIX(regs_allocated) : 2;
+
+  /* Set to zero when `regex_compile' compiles a pattern; set to one
+     by `re_compile_fastmap' if it updates the fastmap.  */
+  unsigned __REPB_PREFIX(fastmap_accurate) : 1;
+
+  /* If set, `re_match_2' does not return information about
+     subexpressions.  */
+  unsigned __REPB_PREFIX(no_sub) : 1;
+
+  /* If set, a beginning-of-line anchor doesn't match at the beginning
+     of the string.  */
+  unsigned __REPB_PREFIX(not_bol) : 1;
+
+  /* Similarly for an end-of-line anchor.  */
+  unsigned __REPB_PREFIX(not_eol) : 1;
+
+  /* If true, an anchor at a newline matches.  */
+  unsigned __REPB_PREFIX(newline_anchor) : 1;
+};
+
+typedef struct re_pattern_buffer regex_t;
+
+/* Type for byte offsets within the string.  POSIX mandates this.  */
+typedef int regoff_t;
+
+
+#ifdef __USE_GNU
+/* This is the structure we store register match data in.  See
+   regex.texinfo for a full description of what registers match.  */
+struct re_registers
+{
+  unsigned num_regs;
+  regoff_t *start;
+  regoff_t *end;
+};
+
+
+/* If `regs_allocated' is REGS_UNALLOCATED in the pattern buffer,
+   `re_match_2' returns information about at least this many registers
+   the first time a `regs' structure is passed.  */
+# ifndef RE_NREGS
+#  define RE_NREGS 30
+# endif
+#endif
+
+
+/* POSIX specification for registers.  Aside from the different names than
+   `re_registers', POSIX uses an array of structures, instead of a
+   structure of arrays.  */
+typedef struct
+{
+  regoff_t rm_so;  /* Byte offset from string's start to substring's start.  */
+  regoff_t rm_eo;  /* Byte offset from string's start to substring's end.  */
+} regmatch_t;
+
+/* Declarations for routines.  */
+
+#ifdef __USE_GNU
+/* Sets the current default syntax to SYNTAX, and return the old syntax.
+   You can also simply assign to the `re_syntax_options' variable.  */
+extern reg_syntax_t re_set_syntax (reg_syntax_t __syntax);
+
+/* Compile the regular expression PATTERN, with length LENGTH
+   and syntax given by the global `re_syntax_options', into the buffer
+   BUFFER.  Return NULL if successful, and an error string if not.  */
+extern const char *re_compile_pattern (const char *__pattern, size_t __length,
+				       struct re_pattern_buffer *__buffer);
+
+
+/* Compile a fastmap for the compiled pattern in BUFFER; used to
+   accelerate searches.  Return 0 if successful and -2 if was an
+   internal error.  */
+extern int re_compile_fastmap (struct re_pattern_buffer *__buffer);
+
+
+/* Search in the string STRING (with length LENGTH) for the pattern
+   compiled into BUFFER.  Start searching at position START, for RANGE
+   characters.  Return the starting position of the match, -1 for no
+   match, or -2 for an internal error.  Also return register
+   information in REGS (if REGS and BUFFER->no_sub are nonzero).  */
+extern int re_search (struct re_pattern_buffer *__buffer, const char *__cstring,
+		      int __length, int __start, int __range,
+		      struct re_registers *__regs);
+
+
+/* Like `re_search', but search in the concatenation of STRING1 and
+   STRING2.  Also, stop searching at index START + STOP.  */
+extern int re_search_2 (struct re_pattern_buffer *__buffer,
+			const char *__string1, int __length1,
+			const char *__string2, int __length2, int __start,
+			int __range, struct re_registers *__regs, int __stop);
+
+
+/* Like `re_search', but return how many characters in STRING the regexp
+   in BUFFER matched, starting at position START.  */
+extern int re_match (struct re_pattern_buffer *__buffer, const char *__cstring,
+		     int __length, int __start, struct re_registers *__regs);
+
+
+/* Relates to `re_match' as `re_search_2' relates to `re_search'.  */
+extern int re_match_2 (struct re_pattern_buffer *__buffer,
+		       const char *__string1, int __length1,
+		       const char *__string2, int __length2, int __start,
+		       struct re_registers *__regs, int __stop);
+
+
+/* Set REGS to hold NUM_REGS registers, storing them in STARTS and
+   ENDS.  Subsequent matches using BUFFER and REGS will use this memory
+   for recording register information.  STARTS and ENDS must be
+   allocated with malloc, and must each be at least `NUM_REGS * sizeof
+   (regoff_t)' bytes long.
+
+   If NUM_REGS == 0, then subsequent matches should allocate their own
+   register data.
+
+   Unless this function is called, the first search or match using
+   PATTERN_BUFFER will allocate its own register data, without
+   freeing the old data.  */
+extern void re_set_registers (struct re_pattern_buffer *__buffer,
+			      struct re_registers *__regs,
+			      unsigned int __num_regs,
+			      regoff_t *__starts, regoff_t *__ends);
+#endif	/* Use GNU */
+
+#if defined _REGEX_RE_COMP || (defined _LIBC && defined __USE_BSD)
+# ifndef _CRAY
+/* 4.2 bsd compatibility.  */
+extern char *re_comp (const char *);
+extern int re_exec (const char *);
+# endif
+#endif
+
+/* GCC 2.95 and later have "__restrict"; C99 compilers have
+   "restrict", and "configure" may have defined "restrict".  */
+#ifndef __restrict
+# if ! (2 < __GNUC__ || (2 == __GNUC__ && 95 <= __GNUC_MINOR__))
+#  if defined restrict || 199901L <= __STDC_VERSION__
+#   define __restrict restrict
+#  else
+#   define __restrict
+#  endif
+# endif
+#endif
+/* gcc 3.1 and up support the [restrict] syntax.  */
+#ifndef __restrict_arr
+# if (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)) \
+     && !defined __GNUG__
+#  define __restrict_arr __restrict
+# else
+#  define __restrict_arr
+# endif
+#endif
+
+/* POSIX compatibility.  */
+extern int regcomp (regex_t *__restrict __preg,
+		    const char *__restrict __pattern,
+		    int __cflags);
+
+extern int regexec (const regex_t *__restrict __preg,
+		    const char *__restrict __cstring, size_t __nmatch,
+		    regmatch_t __pmatch[__restrict_arr],
+		    int __eflags);
+
+extern size_t regerror (int __errcode, const regex_t *__restrict __preg,
+			char *__restrict __errbuf, size_t __errbuf_size);
+
+extern void regfree (regex_t *__preg);
+
+
+#ifdef __cplusplus
+}
+#endif	/* C++ */
+
+#endif /* regex.h */

vendor/libgit2-sys/libgit2/deps/regex/regex_internal.c

diff --git a/vendor/libgit2-sys/libgit2/deps/regex/regex_internal.c b/vendor/libgit2-sys/libgit2/deps/regex/regex_internal.c
new file mode 100644
index 0000000..ad57c20
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/regex/regex_internal.c
@@ -0,0 +1,1744 @@
+/* Extended regular expression matching and search library.
+   Copyright (C) 2002-2006, 2010 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301 USA.  */
+
+static void re_string_construct_common (const char *str, int len,
+					re_string_t *pstr,
+					RE_TRANSLATE_TYPE trans, int icase,
+					const re_dfa_t *dfa) internal_function;
+static re_dfastate_t *create_ci_newstate (const re_dfa_t *dfa,
+					  const re_node_set *nodes,
+					  unsigned int hash) internal_function;
+static re_dfastate_t *create_cd_newstate (const re_dfa_t *dfa,
+					  const re_node_set *nodes,
+					  unsigned int context,
+					  unsigned int hash) internal_function;
+
+#ifdef GAWK
+#undef MAX	/* safety */
+static size_t
+MAX(size_t a, size_t b)
+{
+	return (a > b ? a : b);
+}
+#endif
+
+/* Functions for string operation.  */
+
+/* This function allocate the buffers.  It is necessary to call
+   re_string_reconstruct before using the object.  */
+
+static reg_errcode_t
+internal_function
+re_string_allocate (re_string_t *pstr, const char *str, int len, int init_len,
+		    RE_TRANSLATE_TYPE trans, int icase, const re_dfa_t *dfa)
+{
+  reg_errcode_t ret;
+  int init_buf_len;
+
+  /* Ensure at least one character fits into the buffers.  */
+  if (init_len < dfa->mb_cur_max)
+    init_len = dfa->mb_cur_max;
+  init_buf_len = (len + 1 < init_len) ? len + 1: init_len;
+  re_string_construct_common (str, len, pstr, trans, icase, dfa);
+
+  ret = re_string_realloc_buffers (pstr, init_buf_len);
+  if (BE (ret != REG_NOERROR, 0))
+    return ret;
+
+  pstr->word_char = dfa->word_char;
+  pstr->word_ops_used = dfa->word_ops_used;
+  pstr->mbs = pstr->mbs_allocated ? pstr->mbs : (unsigned char *) str;
+  pstr->valid_len = (pstr->mbs_allocated || dfa->mb_cur_max > 1) ? 0 : len;
+  pstr->valid_raw_len = pstr->valid_len;
+  return REG_NOERROR;
+}
+
+/* This function allocate the buffers, and initialize them.  */
+
+static reg_errcode_t
+internal_function
+re_string_construct (re_string_t *pstr, const char *str, int len,
+		     RE_TRANSLATE_TYPE trans, int icase, const re_dfa_t *dfa)
+{
+  reg_errcode_t ret;
+  memset (pstr, '\0', sizeof (re_string_t));
+  re_string_construct_common (str, len, pstr, trans, icase, dfa);
+
+  if (len > 0)
+    {
+      ret = re_string_realloc_buffers (pstr, len + 1);
+      if (BE (ret != REG_NOERROR, 0))
+	return ret;
+    }
+  pstr->mbs = pstr->mbs_allocated ? pstr->mbs : (unsigned char *) str;
+
+  if (icase)
+    {
+#ifdef RE_ENABLE_I18N
+      if (dfa->mb_cur_max > 1)
+	{
+	  while (1)
+	    {
+	      ret = build_wcs_upper_buffer (pstr);
+	      if (BE (ret != REG_NOERROR, 0))
+		return ret;
+	      if (pstr->valid_raw_len >= len)
+		break;
+	      if (pstr->bufs_len > pstr->valid_len + dfa->mb_cur_max)
+		break;
+	      ret = re_string_realloc_buffers (pstr, pstr->bufs_len * 2);
+	      if (BE (ret != REG_NOERROR, 0))
+		return ret;
+	    }
+	}
+      else
+#endif /* RE_ENABLE_I18N  */
+	build_upper_buffer (pstr);
+    }
+  else
+    {
+#ifdef RE_ENABLE_I18N
+      if (dfa->mb_cur_max > 1)
+	build_wcs_buffer (pstr);
+      else
+#endif /* RE_ENABLE_I18N  */
+	{
+	  if (trans != NULL)
+	    re_string_translate_buffer (pstr);
+	  else
+	    {
+	      pstr->valid_len = pstr->bufs_len;
+	      pstr->valid_raw_len = pstr->bufs_len;
+	    }
+	}
+    }
+
+  return REG_NOERROR;
+}
+
+/* Helper functions for re_string_allocate, and re_string_construct.  */
+
+static reg_errcode_t
+internal_function
+re_string_realloc_buffers (re_string_t *pstr, int new_buf_len)
+{
+#ifdef RE_ENABLE_I18N
+  if (pstr->mb_cur_max > 1)
+    {
+      wint_t *new_wcs;
+
+      /* Avoid overflow in realloc.  */
+      const size_t max_object_size = MAX (sizeof (wint_t), sizeof (int));
+      if (BE (SIZE_MAX / max_object_size < new_buf_len, 0))
+	return REG_ESPACE;
+
+      new_wcs = re_realloc (pstr->wcs, wint_t, new_buf_len);
+      if (BE (new_wcs == NULL, 0))
+	return REG_ESPACE;
+      pstr->wcs = new_wcs;
+      if (pstr->offsets != NULL)
+	{
+	  int *new_offsets = re_realloc (pstr->offsets, int, new_buf_len);
+	  if (BE (new_offsets == NULL, 0))
+	    return REG_ESPACE;
+	  pstr->offsets = new_offsets;
+	}
+    }
+#endif /* RE_ENABLE_I18N  */
+  if (pstr->mbs_allocated)
+    {
+      unsigned char *new_mbs = re_realloc (pstr->mbs, unsigned char,
+					   new_buf_len);
+      if (BE (new_mbs == NULL, 0))
+	return REG_ESPACE;
+      pstr->mbs = new_mbs;
+    }
+  pstr->bufs_len = new_buf_len;
+  return REG_NOERROR;
+}
+
+
+static void
+internal_function
+re_string_construct_common (const char *str, int len, re_string_t *pstr,
+			    RE_TRANSLATE_TYPE trans, int icase,
+			    const re_dfa_t *dfa)
+{
+  pstr->raw_mbs = (const unsigned char *) str;
+  pstr->len = len;
+  pstr->raw_len = len;
+  pstr->trans = trans;
+  pstr->icase = icase ? 1 : 0;
+  pstr->mbs_allocated = (trans != NULL || icase);
+  pstr->mb_cur_max = dfa->mb_cur_max;
+  pstr->is_utf8 = dfa->is_utf8;
+  pstr->map_notascii = dfa->map_notascii;
+  pstr->stop = pstr->len;
+  pstr->raw_stop = pstr->stop;
+}
+
+#ifdef RE_ENABLE_I18N
+
+/* Build wide character buffer PSTR->WCS.
+   If the byte sequence of the string are:
+     <mb1>(0), <mb1>(1), <mb2>(0), <mb2>(1), <sb3>
+   Then wide character buffer will be:
+     <wc1>   , WEOF    , <wc2>   , WEOF    , <wc3>
+   We use WEOF for padding, they indicate that the position isn't
+   a first byte of a multibyte character.
+
+   Note that this function assumes PSTR->VALID_LEN elements are already
+   built and starts from PSTR->VALID_LEN.  */
+
+static void
+internal_function
+build_wcs_buffer (re_string_t *pstr)
+{
+#ifdef _LIBC
+  unsigned char buf[MB_LEN_MAX];
+  assert (MB_LEN_MAX >= pstr->mb_cur_max);
+#else
+  unsigned char buf[64];
+#endif
+  mbstate_t prev_st;
+  int byte_idx, end_idx, remain_len;
+  size_t mbclen;
+
+  /* Build the buffers from pstr->valid_len to either pstr->len or
+     pstr->bufs_len.  */
+  end_idx = (pstr->bufs_len > pstr->len) ? pstr->len : pstr->bufs_len;
+  for (byte_idx = pstr->valid_len; byte_idx < end_idx;)
+    {
+      wchar_t wc;
+      const char *p;
+
+      remain_len = end_idx - byte_idx;
+      prev_st = pstr->cur_state;
+      /* Apply the translation if we need.  */
+      if (BE (pstr->trans != NULL, 0))
+	{
+	  int i, ch;
+
+	  for (i = 0; i < pstr->mb_cur_max && i < remain_len; ++i)
+	    {
+	      ch = pstr->raw_mbs [pstr->raw_mbs_idx + byte_idx + i];
+	      buf[i] = pstr->mbs[byte_idx + i] = pstr->trans[ch];
+	    }
+	  p = (const char *) buf;
+	}
+      else
+	p = (const char *) pstr->raw_mbs + pstr->raw_mbs_idx + byte_idx;
+      mbclen = __mbrtowc (&wc, p, remain_len, &pstr->cur_state);
+      if (BE (mbclen == (size_t) -2, 0))
+	{
+	  /* The buffer doesn't have enough space, finish to build.  */
+	  pstr->cur_state = prev_st;
+	  break;
+	}
+      else if (BE (mbclen == (size_t) -1 || mbclen == 0, 0))
+	{
+	  /* We treat these cases as a singlebyte character.  */
+	  mbclen = 1;
+	  wc = (wchar_t) pstr->raw_mbs[pstr->raw_mbs_idx + byte_idx];
+	  if (BE (pstr->trans != NULL, 0))
+	    wc = pstr->trans[wc];
+	  pstr->cur_state = prev_st;
+	}
+
+      /* Write wide character and padding.  */
+      pstr->wcs[byte_idx++] = wc;
+      /* Write paddings.  */
+      for (remain_len = byte_idx + mbclen - 1; byte_idx < remain_len ;)
+	pstr->wcs[byte_idx++] = WEOF;
+    }
+  pstr->valid_len = byte_idx;
+  pstr->valid_raw_len = byte_idx;
+}
+
+/* Build wide character buffer PSTR->WCS like build_wcs_buffer,
+   but for REG_ICASE.  */
+
+static reg_errcode_t
+internal_function
+build_wcs_upper_buffer (re_string_t *pstr)
+{
+  mbstate_t prev_st;
+  int src_idx, byte_idx, end_idx, remain_len;
+  size_t mbclen;
+#ifdef _LIBC
+  char buf[MB_LEN_MAX];
+  assert (MB_LEN_MAX >= pstr->mb_cur_max);
+#else
+  char buf[64];
+#endif
+
+  byte_idx = pstr->valid_len;
+  end_idx = (pstr->bufs_len > pstr->len) ? pstr->len : pstr->bufs_len;
+
+  /* The following optimization assumes that ASCII characters can be
+     mapped to wide characters with a simple cast.  */
+  if (! pstr->map_notascii && pstr->trans == NULL && !pstr->offsets_needed)
+    {
+      while (byte_idx < end_idx)
+	{
+	  wchar_t wc;
+
+	  if (isascii (pstr->raw_mbs[pstr->raw_mbs_idx + byte_idx])
+	      && mbsinit (&pstr->cur_state))
+	    {
+	      /* In case of a singlebyte character.  */
+	      pstr->mbs[byte_idx]
+		= toupper (pstr->raw_mbs[pstr->raw_mbs_idx + byte_idx]);
+	      /* The next step uses the assumption that wchar_t is encoded
+		 ASCII-safe: all ASCII values can be converted like this.  */
+	      pstr->wcs[byte_idx] = (wchar_t) pstr->mbs[byte_idx];
+	      ++byte_idx;
+	      continue;
+	    }
+
+	  remain_len = end_idx - byte_idx;
+	  prev_st = pstr->cur_state;
+	  mbclen = __mbrtowc (&wc,
+			      ((const char *) pstr->raw_mbs + pstr->raw_mbs_idx
+			       + byte_idx), remain_len, &pstr->cur_state);
+	  if (BE (mbclen + 2 > 2, 1))
+	    {
+	      wchar_t wcu = wc;
+	      if (iswlower (wc))
+		{
+		  size_t mbcdlen;
+
+		  wcu = towupper (wc);
+		  mbcdlen = wcrtomb (buf, wcu, &prev_st);
+		  if (BE (mbclen == mbcdlen, 1))
+		    memcpy (pstr->mbs + byte_idx, buf, mbclen);
+		  else
+		    {
+		      src_idx = byte_idx;
+		      goto offsets_needed;
+		    }
+		}
+	      else
+		memcpy (pstr->mbs + byte_idx,
+			pstr->raw_mbs + pstr->raw_mbs_idx + byte_idx, mbclen);
+	      pstr->wcs[byte_idx++] = wcu;
+	      /* Write paddings.  */
+	      for (remain_len = byte_idx + mbclen - 1; byte_idx < remain_len ;)
+		pstr->wcs[byte_idx++] = WEOF;
+	    }
+	  else if (mbclen == (size_t) -1 || mbclen == 0)
+	    {
+	      /* It is an invalid character or '\0'.  Just use the byte.  */
+	      int ch = pstr->raw_mbs[pstr->raw_mbs_idx + byte_idx];
+	      pstr->mbs[byte_idx] = ch;
+	      /* And also cast it to wide char.  */
+	      pstr->wcs[byte_idx++] = (wchar_t) ch;
+	      if (BE (mbclen == (size_t) -1, 0))
+		pstr->cur_state = prev_st;
+	    }
+	  else
+	    {
+	      /* The buffer doesn't have enough space, finish to build.  */
+	      pstr->cur_state = prev_st;
+	      break;
+	    }
+	}
+      pstr->valid_len = byte_idx;
+      pstr->valid_raw_len = byte_idx;
+      return REG_NOERROR;
+    }
+  else
+    for (src_idx = pstr->valid_raw_len; byte_idx < end_idx;)
+      {
+	wchar_t wc;
+	const char *p;
+      offsets_needed:
+	remain_len = end_idx - byte_idx;
+	prev_st = pstr->cur_state;
+	if (BE (pstr->trans != NULL, 0))
+	  {
+	    int i, ch;
+
+	    for (i = 0; i < pstr->mb_cur_max && i < remain_len; ++i)
+	      {
+		ch = pstr->raw_mbs [pstr->raw_mbs_idx + src_idx + i];
+		buf[i] = pstr->trans[ch];
+	      }
+	    p = (const char *) buf;
+	  }
+	else
+	  p = (const char *) pstr->raw_mbs + pstr->raw_mbs_idx + src_idx;
+	mbclen = __mbrtowc (&wc, p, remain_len, &pstr->cur_state);
+	if (BE (mbclen + 2 > 2, 1))
+	  {
+	    wchar_t wcu = wc;
+	    if (iswlower (wc))
+	      {
+		size_t mbcdlen;
+
+		wcu = towupper (wc);
+		mbcdlen = wcrtomb ((char *) buf, wcu, &prev_st);
+		if (BE (mbclen == mbcdlen, 1))
+		  memcpy (pstr->mbs + byte_idx, buf, mbclen);
+		else if (mbcdlen != (size_t) -1)
+		  {
+		    size_t i;
+
+		    if (byte_idx + mbcdlen > pstr->bufs_len)
+		      {
+			pstr->cur_state = prev_st;
+			break;
+		      }
+
+		    if (pstr->offsets == NULL)
+		      {
+			pstr->offsets = re_malloc (int, pstr->bufs_len);
+
+			if (pstr->offsets == NULL)
+			  return REG_ESPACE;
+		      }
+		    if (!pstr->offsets_needed)
+		      {
+			for (i = 0; i < (size_t) byte_idx; ++i)
+			  pstr->offsets[i] = i;
+			pstr->offsets_needed = 1;
+		      }
+
+		    memcpy (pstr->mbs + byte_idx, buf, mbcdlen);
+		    pstr->wcs[byte_idx] = wcu;
+		    pstr->offsets[byte_idx] = src_idx;
+		    for (i = 1; i < mbcdlen; ++i)
+		      {
+			pstr->offsets[byte_idx + i]
+			  = src_idx + (i < mbclen ? i : mbclen - 1);
+			pstr->wcs[byte_idx + i] = WEOF;
+		      }
+		    pstr->len += mbcdlen - mbclen;
+		    if (pstr->raw_stop > src_idx)
+		      pstr->stop += mbcdlen - mbclen;
+		    end_idx = (pstr->bufs_len > pstr->len)
+			      ? pstr->len : pstr->bufs_len;
+		    byte_idx += mbcdlen;
+		    src_idx += mbclen;
+		    continue;
+		  }
+		else
+		  memcpy (pstr->mbs + byte_idx, p, mbclen);
+	      }
+	    else
+	      memcpy (pstr->mbs + byte_idx, p, mbclen);
+
+	    if (BE (pstr->offsets_needed != 0, 0))
+	      {
+		size_t i;
+		for (i = 0; i < mbclen; ++i)
+		  pstr->offsets[byte_idx + i] = src_idx + i;
+	      }
+	    src_idx += mbclen;
+
+	    pstr->wcs[byte_idx++] = wcu;
+	    /* Write paddings.  */
+	    for (remain_len = byte_idx + mbclen - 1; byte_idx < remain_len ;)
+	      pstr->wcs[byte_idx++] = WEOF;
+	  }
+	else if (mbclen == (size_t) -1 || mbclen == 0)
+	  {
+	    /* It is an invalid character or '\0'.  Just use the byte.  */
+	    int ch = pstr->raw_mbs[pstr->raw_mbs_idx + src_idx];
+
+	    if (BE (pstr->trans != NULL, 0))
+	      ch = pstr->trans [ch];
+	    pstr->mbs[byte_idx] = ch;
+
+	    if (BE (pstr->offsets_needed != 0, 0))
+	      pstr->offsets[byte_idx] = src_idx;
+	    ++src_idx;
+
+	    /* And also cast it to wide char.  */
+	    pstr->wcs[byte_idx++] = (wchar_t) ch;
+	    if (BE (mbclen == (size_t) -1, 0))
+	      pstr->cur_state = prev_st;
+	  }
+	else
+	  {
+	    /* The buffer doesn't have enough space, finish to build.  */
+	    pstr->cur_state = prev_st;
+	    break;
+	  }
+      }
+  pstr->valid_len = byte_idx;
+  pstr->valid_raw_len = src_idx;
+  return REG_NOERROR;
+}
+
+/* Skip characters until the index becomes greater than NEW_RAW_IDX.
+   Return the index.  */
+
+static int
+internal_function
+re_string_skip_chars (re_string_t *pstr, int new_raw_idx, wint_t *last_wc)
+{
+  mbstate_t prev_st;
+  int rawbuf_idx;
+  size_t mbclen;
+  wint_t wc = WEOF;
+
+  /* Skip the characters which are not necessary to check.  */
+  for (rawbuf_idx = pstr->raw_mbs_idx + pstr->valid_raw_len;
+       rawbuf_idx < new_raw_idx;)
+    {
+      wchar_t wc2;
+      int remain_len = pstr->len - rawbuf_idx;
+      prev_st = pstr->cur_state;
+      mbclen = __mbrtowc (&wc2, (const char *) pstr->raw_mbs + rawbuf_idx,
+			  remain_len, &pstr->cur_state);
+      if (BE (mbclen == (size_t) -2 || mbclen == (size_t) -1 || mbclen == 0, 0))
+	{
+	  /* We treat these cases as a single byte character.  */
+	  if (mbclen == 0 || remain_len == 0)
+	    wc = L'\0';
+	  else
+	    wc = *(unsigned char *) (pstr->raw_mbs + rawbuf_idx);
+	  mbclen = 1;
+	  pstr->cur_state = prev_st;
+	}
+      else
+	wc = (wint_t) wc2;
+      /* Then proceed the next character.  */
+      rawbuf_idx += mbclen;
+    }
+  *last_wc = (wint_t) wc;
+  return rawbuf_idx;
+}
+#endif /* RE_ENABLE_I18N  */
+
+/* Build the buffer PSTR->MBS, and apply the translation if we need.
+   This function is used in case of REG_ICASE.  */
+
+static void
+internal_function
+build_upper_buffer (re_string_t *pstr)
+{
+  int char_idx, end_idx;
+  end_idx = (pstr->bufs_len > pstr->len) ? pstr->len : pstr->bufs_len;
+
+  for (char_idx = pstr->valid_len; char_idx < end_idx; ++char_idx)
+    {
+      int ch = pstr->raw_mbs[pstr->raw_mbs_idx + char_idx];
+      if (BE (pstr->trans != NULL, 0))
+	ch = pstr->trans[ch];
+      if (islower (ch))
+	pstr->mbs[char_idx] = toupper (ch);
+      else
+	pstr->mbs[char_idx] = ch;
+    }
+  pstr->valid_len = char_idx;
+  pstr->valid_raw_len = char_idx;
+}
+
+/* Apply TRANS to the buffer in PSTR.  */
+
+static void
+internal_function
+re_string_translate_buffer (re_string_t *pstr)
+{
+  int buf_idx, end_idx;
+  end_idx = (pstr->bufs_len > pstr->len) ? pstr->len : pstr->bufs_len;
+
+  for (buf_idx = pstr->valid_len; buf_idx < end_idx; ++buf_idx)
+    {
+      int ch = pstr->raw_mbs[pstr->raw_mbs_idx + buf_idx];
+      pstr->mbs[buf_idx] = pstr->trans[ch];
+    }
+
+  pstr->valid_len = buf_idx;
+  pstr->valid_raw_len = buf_idx;
+}
+
+/* This function re-construct the buffers.
+   Concretely, convert to wide character in case of pstr->mb_cur_max > 1,
+   convert to upper case in case of REG_ICASE, apply translation.  */
+
+static reg_errcode_t
+internal_function
+re_string_reconstruct (re_string_t *pstr, int idx, int eflags)
+{
+  int offset = idx - pstr->raw_mbs_idx;
+  if (BE (offset < 0, 0))
+    {
+      /* Reset buffer.  */
+#ifdef RE_ENABLE_I18N
+      if (pstr->mb_cur_max > 1)
+	memset (&pstr->cur_state, '\0', sizeof (mbstate_t));
+#endif /* RE_ENABLE_I18N */
+      pstr->len = pstr->raw_len;
+      pstr->stop = pstr->raw_stop;
+      pstr->valid_len = 0;
+      pstr->raw_mbs_idx = 0;
+      pstr->valid_raw_len = 0;
+      pstr->offsets_needed = 0;
+      pstr->tip_context = ((eflags & REG_NOTBOL) ? CONTEXT_BEGBUF
+			   : CONTEXT_NEWLINE | CONTEXT_BEGBUF);
+      if (!pstr->mbs_allocated)
+	pstr->mbs = (unsigned char *) pstr->raw_mbs;
+      offset = idx;
+    }
+
+  if (BE (offset != 0, 1))
+    {
+      /* Should the already checked characters be kept?  */
+      if (BE (offset < pstr->valid_raw_len, 1))
+	{
+	  /* Yes, move them to the front of the buffer.  */
+#ifdef RE_ENABLE_I18N
+	  if (BE (pstr->offsets_needed, 0))
+	    {
+	      int low = 0, high = pstr->valid_len, mid;
+	      do
+		{
+		  mid = (high + low) / 2;
+		  if (pstr->offsets[mid] > offset)
+		    high = mid;
+		  else if (pstr->offsets[mid] < offset)
+		    low = mid + 1;
+		  else
+		    break;
+		}
+	      while (low < high);
+	      if (pstr->offsets[mid] < offset)
+		++mid;
+	      pstr->tip_context = re_string_context_at (pstr, mid - 1,
+							eflags);
+	      /* This can be quite complicated, so handle specially
+		 only the common and easy case where the character with
+		 different length representation of lower and upper
+		 case is present at or after offset.  */
+	      if (pstr->valid_len > offset
+		  && mid == offset && pstr->offsets[mid] == offset)
+		{
+		  memmove (pstr->wcs, pstr->wcs + offset,
+			   (pstr->valid_len - offset) * sizeof (wint_t));
+		  memmove (pstr->mbs, pstr->mbs + offset, pstr->valid_len - offset);
+		  pstr->valid_len -= offset;
+		  pstr->valid_raw_len -= offset;
+		  for (low = 0; low < pstr->valid_len; low++)
+		    pstr->offsets[low] = pstr->offsets[low + offset] - offset;
+		}
+	      else
+		{
+		  /* Otherwise, just find out how long the partial multibyte
+		     character at offset is and fill it with WEOF/255.  */
+		  pstr->len = pstr->raw_len - idx + offset;
+		  pstr->stop = pstr->raw_stop - idx + offset;
+		  pstr->offsets_needed = 0;
+		  while (mid > 0 && pstr->offsets[mid - 1] == offset)
+		    --mid;
+		  while (mid < pstr->valid_len)
+		    if (pstr->wcs[mid] != WEOF)
+		      break;
+		    else
+		      ++mid;
+		  if (mid == pstr->valid_len)
+		    pstr->valid_len = 0;
+		  else
+		    {
+		      pstr->valid_len = pstr->offsets[mid] - offset;
+		      if (pstr->valid_len)
+			{
+			  for (low = 0; low < pstr->valid_len; ++low)
+			    pstr->wcs[low] = WEOF;
+			  memset (pstr->mbs, 255, pstr->valid_len);
+			}
+		    }
+		  pstr->valid_raw_len = pstr->valid_len;
+		}
+	    }
+	  else
+#endif
+	    {
+	      pstr->tip_context = re_string_context_at (pstr, offset - 1,
+							eflags);
+#ifdef RE_ENABLE_I18N
+	      if (pstr->mb_cur_max > 1)
+		memmove (pstr->wcs, pstr->wcs + offset,
+			 (pstr->valid_len - offset) * sizeof (wint_t));
+#endif /* RE_ENABLE_I18N */
+	      if (BE (pstr->mbs_allocated, 0))
+		memmove (pstr->mbs, pstr->mbs + offset,
+			 pstr->valid_len - offset);
+	      pstr->valid_len -= offset;
+	      pstr->valid_raw_len -= offset;
+#if DEBUG
+	      assert (pstr->valid_len > 0);
+#endif
+	    }
+	}
+      else
+	{
+#ifdef RE_ENABLE_I18N
+	  /* No, skip all characters until IDX.  */
+	  int prev_valid_len = pstr->valid_len;
+
+	  if (BE (pstr->offsets_needed, 0))
+	    {
+	      pstr->len = pstr->raw_len - idx + offset;
+	      pstr->stop = pstr->raw_stop - idx + offset;
+	      pstr->offsets_needed = 0;
+	    }
+#endif
+	  pstr->valid_len = 0;
+#ifdef RE_ENABLE_I18N
+	  if (pstr->mb_cur_max > 1)
+	    {
+	      int wcs_idx;
+	      wint_t wc = WEOF;
+
+	      if (pstr->is_utf8)
+		{
+		  const unsigned char *raw, *p, *end;
+
+		  /* Special case UTF-8.  Multi-byte chars start with any
+		     byte other than 0x80 - 0xbf.  */
+		  raw = pstr->raw_mbs + pstr->raw_mbs_idx;
+		  end = raw + (offset - pstr->mb_cur_max);
+		  if (end < pstr->raw_mbs)
+		    end = pstr->raw_mbs;
+		  p = raw + offset - 1;
+#ifdef _LIBC
+		  /* We know the wchar_t encoding is UCS4, so for the simple
+		     case, ASCII characters, skip the conversion step.  */
+		  if (isascii (*p) && BE (pstr->trans == NULL, 1))
+		    {
+		      memset (&pstr->cur_state, '\0', sizeof (mbstate_t));
+		      /* pstr->valid_len = 0; */
+		      wc = (wchar_t) *p;
+		    }
+		  else
+#endif
+		    for (; p >= end; --p)
+		      if ((*p & 0xc0) != 0x80)
+			{
+			  mbstate_t cur_state;
+			  wchar_t wc2;
+			  int mlen = raw + pstr->len - p;
+			  unsigned char buf[6];
+			  size_t mbclen;
+
+			  if (BE (pstr->trans != NULL, 0))
+			    {
+			      int i = mlen < 6 ? mlen : 6;
+			      while (--i >= 0)
+				buf[i] = pstr->trans[p[i]];
+			    }
+			  /* XXX Don't use mbrtowc, we know which conversion
+			     to use (UTF-8 -> UCS4).  */
+			  memset (&cur_state, 0, sizeof (cur_state));
+			  mbclen = __mbrtowc (&wc2, (const char *) p, mlen,
+					      &cur_state);
+			  if (raw + offset - p <= mbclen
+			      && mbclen < (size_t) -2)
+			    {
+			      memset (&pstr->cur_state, '\0',
+				      sizeof (mbstate_t));
+			      pstr->valid_len = mbclen - (raw + offset - p);
+			      wc = wc2;
+			    }
+			  break;
+			}
+		}
+
+	      if (wc == WEOF)
+		pstr->valid_len = re_string_skip_chars (pstr, idx, &wc) - idx;
+	      if (wc == WEOF)
+		pstr->tip_context
+		  = re_string_context_at (pstr, prev_valid_len - 1, eflags);
+	      else
+		pstr->tip_context = ((BE (pstr->word_ops_used != 0, 0)
+				      && IS_WIDE_WORD_CHAR (wc))
+				     ? CONTEXT_WORD
+				     : ((IS_WIDE_NEWLINE (wc)
+					 && pstr->newline_anchor)
+					? CONTEXT_NEWLINE : 0));
+	      if (BE (pstr->valid_len, 0))
+		{
+		  for (wcs_idx = 0; wcs_idx < pstr->valid_len; ++wcs_idx)
+		    pstr->wcs[wcs_idx] = WEOF;
+		  if (pstr->mbs_allocated)
+		    memset (pstr->mbs, 255, pstr->valid_len);
+		}
+	      pstr->valid_raw_len = pstr->valid_len;
+	    }
+	  else
+#endif /* RE_ENABLE_I18N */
+	    {
+	      int c = pstr->raw_mbs[pstr->raw_mbs_idx + offset - 1];
+	      pstr->valid_raw_len = 0;
+	      if (pstr->trans)
+		c = pstr->trans[c];
+	      pstr->tip_context = (bitset_contain (pstr->word_char, c)
+				   ? CONTEXT_WORD
+				   : ((IS_NEWLINE (c) && pstr->newline_anchor)
+				      ? CONTEXT_NEWLINE : 0));
+	    }
+	}
+      if (!BE (pstr->mbs_allocated, 0))
+	pstr->mbs += offset;
+    }
+  pstr->raw_mbs_idx = idx;
+  pstr->len -= offset;
+  pstr->stop -= offset;
+
+  /* Then build the buffers.  */
+#ifdef RE_ENABLE_I18N
+  if (pstr->mb_cur_max > 1)
+    {
+      if (pstr->icase)
+	{
+	  reg_errcode_t ret = build_wcs_upper_buffer (pstr);
+	  if (BE (ret != REG_NOERROR, 0))
+	    return ret;
+	}
+      else
+	build_wcs_buffer (pstr);
+    }
+  else
+#endif /* RE_ENABLE_I18N */
+    if (BE (pstr->mbs_allocated, 0))
+      {
+	if (pstr->icase)
+	  build_upper_buffer (pstr);
+	else if (pstr->trans != NULL)
+	  re_string_translate_buffer (pstr);
+      }
+    else
+      pstr->valid_len = pstr->len;
+
+  pstr->cur_idx = 0;
+  return REG_NOERROR;
+}
+
+static unsigned char
+internal_function __attribute ((pure))
+re_string_peek_byte_case (const re_string_t *pstr, int idx)
+{
+  int ch, off;
+
+  /* Handle the common (easiest) cases first.  */
+  if (BE (!pstr->mbs_allocated, 1))
+    return re_string_peek_byte (pstr, idx);
+
+#ifdef RE_ENABLE_I18N
+  if (pstr->mb_cur_max > 1
+      && ! re_string_is_single_byte_char (pstr, pstr->cur_idx + idx))
+    return re_string_peek_byte (pstr, idx);
+#endif
+
+  off = pstr->cur_idx + idx;
+#ifdef RE_ENABLE_I18N
+  if (pstr->offsets_needed)
+    off = pstr->offsets[off];
+#endif
+
+  ch = pstr->raw_mbs[pstr->raw_mbs_idx + off];
+
+#ifdef RE_ENABLE_I18N
+  /* Ensure that e.g. for tr_TR.UTF-8 BACKSLASH DOTLESS SMALL LETTER I
+     this function returns CAPITAL LETTER I instead of first byte of
+     DOTLESS SMALL LETTER I.  The latter would confuse the parser,
+     since peek_byte_case doesn't advance cur_idx in any way.  */
+  if (pstr->offsets_needed && !isascii (ch))
+    return re_string_peek_byte (pstr, idx);
+#endif
+
+  return ch;
+}
+
+static unsigned char
+internal_function __attribute ((pure))
+re_string_fetch_byte_case (re_string_t *pstr)
+{
+  if (BE (!pstr->mbs_allocated, 1))
+    return re_string_fetch_byte (pstr);
+
+#ifdef RE_ENABLE_I18N
+  if (pstr->offsets_needed)
+    {
+      int off, ch;
+
+      /* For tr_TR.UTF-8 [[:islower:]] there is
+	 [[: CAPITAL LETTER I WITH DOT lower:]] in mbs.  Skip
+	 in that case the whole multi-byte character and return
+	 the original letter.  On the other side, with
+	 [[: DOTLESS SMALL LETTER I return [[:I, as doing
+	 anything else would complicate things too much.  */
+
+      if (!re_string_first_byte (pstr, pstr->cur_idx))
+	return re_string_fetch_byte (pstr);
+
+      off = pstr->offsets[pstr->cur_idx];
+      ch = pstr->raw_mbs[pstr->raw_mbs_idx + off];
+
+      if (! isascii (ch))
+	return re_string_fetch_byte (pstr);
+
+      re_string_skip_bytes (pstr,
+			    re_string_char_size_at (pstr, pstr->cur_idx));
+      return ch;
+    }
+#endif
+
+  return pstr->raw_mbs[pstr->raw_mbs_idx + pstr->cur_idx++];
+}
+
+static void
+internal_function
+re_string_destruct (re_string_t *pstr)
+{
+#ifdef RE_ENABLE_I18N
+  re_free (pstr->wcs);
+  re_free (pstr->offsets);
+#endif /* RE_ENABLE_I18N  */
+  if (pstr->mbs_allocated)
+    re_free (pstr->mbs);
+}
+
+/* Return the context at IDX in INPUT.  */
+
+static unsigned int
+internal_function
+re_string_context_at (const re_string_t *input, int idx, int eflags)
+{
+  int c;
+  if (BE (idx < 0, 0))
+    /* In this case, we use the value stored in input->tip_context,
+       since we can't know the character in input->mbs[-1] here.  */
+    return input->tip_context;
+  if (BE (idx == input->len, 0))
+    return ((eflags & REG_NOTEOL) ? CONTEXT_ENDBUF
+	    : CONTEXT_NEWLINE | CONTEXT_ENDBUF);
+#ifdef RE_ENABLE_I18N
+  if (input->mb_cur_max > 1)
+    {
+      wint_t wc;
+      int wc_idx = idx;
+      while(input->wcs[wc_idx] == WEOF)
+	{
+#ifdef DEBUG
+	  /* It must not happen.  */
+	  assert (wc_idx >= 0);
+#endif
+	  --wc_idx;
+	  if (wc_idx < 0)
+	    return input->tip_context;
+	}
+      wc = input->wcs[wc_idx];
+      if (BE (input->word_ops_used != 0, 0) && IS_WIDE_WORD_CHAR (wc))
+	return CONTEXT_WORD;
+      return (IS_WIDE_NEWLINE (wc) && input->newline_anchor
+	      ? CONTEXT_NEWLINE : 0);
+    }
+  else
+#endif
+    {
+      c = re_string_byte_at (input, idx);
+      if (bitset_contain (input->word_char, c))
+	return CONTEXT_WORD;
+      return IS_NEWLINE (c) && input->newline_anchor ? CONTEXT_NEWLINE : 0;
+    }
+}
+
+/* Functions for set operation.  */
+
+static reg_errcode_t
+internal_function
+re_node_set_alloc (re_node_set *set, int size)
+{
+  /*
+   * ADR: valgrind says size can be 0, which then doesn't
+   * free the block of size 0.  Harumph. This seems
+   * to work ok, though.
+   */
+  if (size == 0)
+    {
+       memset(set, 0, sizeof(*set));
+       return REG_NOERROR;
+    }
+  set->alloc = size;
+  set->nelem = 0;
+  set->elems = re_malloc (int, size);
+  if (BE (set->elems == NULL, 0))
+    return REG_ESPACE;
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function
+re_node_set_init_1 (re_node_set *set, int elem)
+{
+  set->alloc = 1;
+  set->nelem = 1;
+  set->elems = re_malloc (int, 1);
+  if (BE (set->elems == NULL, 0))
+    {
+      set->alloc = set->nelem = 0;
+      return REG_ESPACE;
+    }
+  set->elems[0] = elem;
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function
+re_node_set_init_2 (re_node_set *set, int elem1, int elem2)
+{
+  set->alloc = 2;
+  set->elems = re_malloc (int, 2);
+  if (BE (set->elems == NULL, 0))
+    return REG_ESPACE;
+  if (elem1 == elem2)
+    {
+      set->nelem = 1;
+      set->elems[0] = elem1;
+    }
+  else
+    {
+      set->nelem = 2;
+      if (elem1 < elem2)
+	{
+	  set->elems[0] = elem1;
+	  set->elems[1] = elem2;
+	}
+      else
+	{
+	  set->elems[0] = elem2;
+	  set->elems[1] = elem1;
+	}
+    }
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function
+re_node_set_init_copy (re_node_set *dest, const re_node_set *src)
+{
+  dest->nelem = src->nelem;
+  if (src->nelem > 0)
+    {
+      dest->alloc = dest->nelem;
+      dest->elems = re_malloc (int, dest->alloc);
+      if (BE (dest->elems == NULL, 0))
+	{
+	  dest->alloc = dest->nelem = 0;
+	  return REG_ESPACE;
+	}
+      memcpy (dest->elems, src->elems, src->nelem * sizeof (int));
+    }
+  else
+    re_node_set_init_empty (dest);
+  return REG_NOERROR;
+}
+
+/* Calculate the intersection of the sets SRC1 and SRC2. And merge it to
+   DEST. Return value indicate the error code or REG_NOERROR if succeeded.
+   Note: We assume dest->elems is NULL, when dest->alloc is 0.  */
+
+static reg_errcode_t
+internal_function
+re_node_set_add_intersect (re_node_set *dest, const re_node_set *src1,
+			   const re_node_set *src2)
+{
+  int i1, i2, is, id, delta, sbase;
+  if (src1->nelem == 0 || src2->nelem == 0)
+    return REG_NOERROR;
+
+  /* We need dest->nelem + 2 * elems_in_intersection; this is a
+     conservative estimate.  */
+  if (src1->nelem + src2->nelem + dest->nelem > dest->alloc)
+    {
+      int new_alloc = src1->nelem + src2->nelem + dest->alloc;
+      int *new_elems = re_realloc (dest->elems, int, new_alloc);
+      if (BE (new_elems == NULL, 0))
+	return REG_ESPACE;
+      dest->elems = new_elems;
+      dest->alloc = new_alloc;
+    }
+
+  /* Find the items in the intersection of SRC1 and SRC2, and copy
+     into the top of DEST those that are not already in DEST itself.  */
+  sbase = dest->nelem + src1->nelem + src2->nelem;
+  i1 = src1->nelem - 1;
+  i2 = src2->nelem - 1;
+  id = dest->nelem - 1;
+  for (;;)
+    {
+      if (src1->elems[i1] == src2->elems[i2])
+	{
+	  /* Try to find the item in DEST.  Maybe we could binary search?  */
+	  while (id >= 0 && dest->elems[id] > src1->elems[i1])
+	    --id;
+
+	  if (id < 0 || dest->elems[id] != src1->elems[i1])
+	    dest->elems[--sbase] = src1->elems[i1];
+
+	  if (--i1 < 0 || --i2 < 0)
+	    break;
+	}
+
+      /* Lower the highest of the two items.  */
+      else if (src1->elems[i1] < src2->elems[i2])
+	{
+	  if (--i2 < 0)
+	    break;
+	}
+      else
+	{
+	  if (--i1 < 0)
+	    break;
+	}
+    }
+
+  id = dest->nelem - 1;
+  is = dest->nelem + src1->nelem + src2->nelem - 1;
+  delta = is - sbase + 1;
+
+  /* Now copy.  When DELTA becomes zero, the remaining
+     DEST elements are already in place; this is more or
+     less the same loop that is in re_node_set_merge.  */
+  dest->nelem += delta;
+  if (delta > 0 && id >= 0)
+    for (;;)
+      {
+	if (dest->elems[is] > dest->elems[id])
+	  {
+	    /* Copy from the top.  */
+	    dest->elems[id + delta--] = dest->elems[is--];
+	    if (delta == 0)
+	      break;
+	  }
+	else
+	  {
+	    /* Slide from the bottom.  */
+	    dest->elems[id + delta] = dest->elems[id];
+	    if (--id < 0)
+	      break;
+	  }
+      }
+
+  /* Copy remaining SRC elements.  */
+  memcpy (dest->elems, dest->elems + sbase, delta * sizeof (int));
+
+  return REG_NOERROR;
+}
+
+/* Calculate the union set of the sets SRC1 and SRC2. And store it to
+   DEST. Return value indicate the error code or REG_NOERROR if succeeded.  */
+
+static reg_errcode_t
+internal_function
+re_node_set_init_union (re_node_set *dest, const re_node_set *src1,
+			const re_node_set *src2)
+{
+  int i1, i2, id;
+  if (src1 != NULL && src1->nelem > 0 && src2 != NULL && src2->nelem > 0)
+    {
+      dest->alloc = src1->nelem + src2->nelem;
+      dest->elems = re_malloc (int, dest->alloc);
+      if (BE (dest->elems == NULL, 0))
+	return REG_ESPACE;
+    }
+  else
+    {
+      if (src1 != NULL && src1->nelem > 0)
+	return re_node_set_init_copy (dest, src1);
+      else if (src2 != NULL && src2->nelem > 0)
+	return re_node_set_init_copy (dest, src2);
+      else
+	re_node_set_init_empty (dest);
+      return REG_NOERROR;
+    }
+  for (i1 = i2 = id = 0 ; i1 < src1->nelem && i2 < src2->nelem ;)
+    {
+      if (src1->elems[i1] > src2->elems[i2])
+	{
+	  dest->elems[id++] = src2->elems[i2++];
+	  continue;
+	}
+      if (src1->elems[i1] == src2->elems[i2])
+	++i2;
+      dest->elems[id++] = src1->elems[i1++];
+    }
+  if (i1 < src1->nelem)
+    {
+      memcpy (dest->elems + id, src1->elems + i1,
+	     (src1->nelem - i1) * sizeof (int));
+      id += src1->nelem - i1;
+    }
+  else if (i2 < src2->nelem)
+    {
+      memcpy (dest->elems + id, src2->elems + i2,
+	     (src2->nelem - i2) * sizeof (int));
+      id += src2->nelem - i2;
+    }
+  dest->nelem = id;
+  return REG_NOERROR;
+}
+
+/* Calculate the union set of the sets DEST and SRC. And store it to
+   DEST. Return value indicate the error code or REG_NOERROR if succeeded.  */
+
+static reg_errcode_t
+internal_function
+re_node_set_merge (re_node_set *dest, const re_node_set *src)
+{
+  int is, id, sbase, delta;
+  if (src == NULL || src->nelem == 0)
+    return REG_NOERROR;
+  if (dest->alloc < 2 * src->nelem + dest->nelem)
+    {
+      int new_alloc = 2 * (src->nelem + dest->alloc);
+      int *new_buffer = re_realloc (dest->elems, int, new_alloc);
+      if (BE (new_buffer == NULL, 0))
+	return REG_ESPACE;
+      dest->elems = new_buffer;
+      dest->alloc = new_alloc;
+    }
+
+  if (BE (dest->nelem == 0, 0))
+    {
+      dest->nelem = src->nelem;
+      memcpy (dest->elems, src->elems, src->nelem * sizeof (int));
+      return REG_NOERROR;
+    }
+
+  /* Copy into the top of DEST the items of SRC that are not
+     found in DEST.  Maybe we could binary search in DEST?  */
+  for (sbase = dest->nelem + 2 * src->nelem,
+       is = src->nelem - 1, id = dest->nelem - 1; is >= 0 && id >= 0; )
+    {
+      if (dest->elems[id] == src->elems[is])
+	is--, id--;
+      else if (dest->elems[id] < src->elems[is])
+	dest->elems[--sbase] = src->elems[is--];
+      else /* if (dest->elems[id] > src->elems[is]) */
+	--id;
+    }
+
+  if (is >= 0)
+    {
+      /* If DEST is exhausted, the remaining items of SRC must be unique.  */
+      sbase -= is + 1;
+      memcpy (dest->elems + sbase, src->elems, (is + 1) * sizeof (int));
+    }
+
+  id = dest->nelem - 1;
+  is = dest->nelem + 2 * src->nelem - 1;
+  delta = is - sbase + 1;
+  if (delta == 0)
+    return REG_NOERROR;
+
+  /* Now copy.  When DELTA becomes zero, the remaining
+     DEST elements are already in place.  */
+  dest->nelem += delta;
+  for (;;)
+    {
+      if (dest->elems[is] > dest->elems[id])
+	{
+	  /* Copy from the top.  */
+	  dest->elems[id + delta--] = dest->elems[is--];
+	  if (delta == 0)
+	    break;
+	}
+      else
+	{
+	  /* Slide from the bottom.  */
+	  dest->elems[id + delta] = dest->elems[id];
+	  if (--id < 0)
+	    {
+	      /* Copy remaining SRC elements.  */
+	      memcpy (dest->elems, dest->elems + sbase,
+		      delta * sizeof (int));
+	      break;
+	    }
+	}
+    }
+
+  return REG_NOERROR;
+}
+
+/* Insert the new element ELEM to the re_node_set* SET.
+   SET should not already have ELEM.
+   return -1 if an error is occured, return 1 otherwise.  */
+
+static int
+internal_function
+re_node_set_insert (re_node_set *set, int elem)
+{
+  int idx;
+  /* In case the set is empty.  */
+  if (set->alloc == 0)
+    {
+      if (BE (re_node_set_init_1 (set, elem) == REG_NOERROR, 1))
+	return 1;
+      else
+	return -1;
+    }
+
+  if (BE (set->nelem, 0) == 0)
+    {
+      /* We already guaranteed above that set->alloc != 0.  */
+      set->elems[0] = elem;
+      ++set->nelem;
+      return 1;
+    }
+
+  /* Realloc if we need.  */
+  if (set->alloc == set->nelem)
+    {
+      int *new_elems;
+      set->alloc = set->alloc * 2;
+      new_elems = re_realloc (set->elems, int, set->alloc);
+      if (BE (new_elems == NULL, 0))
+	return -1;
+      set->elems = new_elems;
+    }
+
+  /* Move the elements which follows the new element.  Test the
+     first element separately to skip a check in the inner loop.  */
+  if (elem < set->elems[0])
+    {
+      idx = 0;
+      for (idx = set->nelem; idx > 0; idx--)
+	set->elems[idx] = set->elems[idx - 1];
+    }
+  else
+    {
+      for (idx = set->nelem; set->elems[idx - 1] > elem; idx--)
+	set->elems[idx] = set->elems[idx - 1];
+    }
+
+  /* Insert the new element.  */
+  set->elems[idx] = elem;
+  ++set->nelem;
+  return 1;
+}
+
+/* Insert the new element ELEM to the re_node_set* SET.
+   SET should not already have any element greater than or equal to ELEM.
+   Return -1 if an error is occured, return 1 otherwise.  */
+
+static int
+internal_function
+re_node_set_insert_last (re_node_set *set, int elem)
+{
+  /* Realloc if we need.  */
+  if (set->alloc == set->nelem)
+    {
+      int *new_elems;
+      set->alloc = (set->alloc + 1) * 2;
+      new_elems = re_realloc (set->elems, int, set->alloc);
+      if (BE (new_elems == NULL, 0))
+	return -1;
+      set->elems = new_elems;
+    }
+
+  /* Insert the new element.  */
+  set->elems[set->nelem++] = elem;
+  return 1;
+}
+
+/* Compare two node sets SET1 and SET2.
+   return 1 if SET1 and SET2 are equivalent, return 0 otherwise.  */
+
+static int
+internal_function __attribute ((pure))
+re_node_set_compare (const re_node_set *set1, const re_node_set *set2)
+{
+  int i;
+  if (set1 == NULL || set2 == NULL || set1->nelem != set2->nelem)
+    return 0;
+  for (i = set1->nelem ; --i >= 0 ; )
+    if (set1->elems[i] != set2->elems[i])
+      return 0;
+  return 1;
+}
+
+/* Return (idx + 1) if SET contains the element ELEM, return 0 otherwise.  */
+
+static int
+internal_function __attribute ((pure))
+re_node_set_contains (const re_node_set *set, int elem)
+{
+  unsigned int idx, right, mid;
+  if (set->nelem <= 0)
+    return 0;
+
+  /* Binary search the element.  */
+  idx = 0;
+  right = set->nelem - 1;
+  while (idx < right)
+    {
+      mid = (idx + right) / 2;
+      if (set->elems[mid] < elem)
+	idx = mid + 1;
+      else
+	right = mid;
+    }
+  return set->elems[idx] == elem ? idx + 1 : 0;
+}
+
+static void
+internal_function
+re_node_set_remove_at (re_node_set *set, int idx)
+{
+  if (idx < 0 || idx >= set->nelem)
+    return;
+  --set->nelem;
+  for (; idx < set->nelem; idx++)
+    set->elems[idx] = set->elems[idx + 1];
+}
+
+
+/* Add the token TOKEN to dfa->nodes, and return the index of the token.
+   Or return -1, if an error will be occured.  */
+
+static int
+internal_function
+re_dfa_add_node (re_dfa_t *dfa, re_token_t token)
+{
+  if (BE (dfa->nodes_len >= dfa->nodes_alloc, 0))
+    {
+      size_t new_nodes_alloc = dfa->nodes_alloc * 2;
+      int *new_nexts, *new_indices;
+      re_node_set *new_edests, *new_eclosures;
+      re_token_t *new_nodes;
+
+      /* Avoid overflows in realloc.  */
+      const size_t max_object_size = MAX (sizeof (re_token_t),
+					  MAX (sizeof (re_node_set),
+					       sizeof (int)));
+      if (BE (SIZE_MAX / max_object_size < new_nodes_alloc, 0))
+	return -1;
+
+      new_nodes = re_realloc (dfa->nodes, re_token_t, new_nodes_alloc);
+      if (BE (new_nodes == NULL, 0))
+	return -1;
+      dfa->nodes = new_nodes;
+      new_nexts = re_realloc (dfa->nexts, int, new_nodes_alloc);
+      new_indices = re_realloc (dfa->org_indices, int, new_nodes_alloc);
+      new_edests = re_realloc (dfa->edests, re_node_set, new_nodes_alloc);
+      new_eclosures = re_realloc (dfa->eclosures, re_node_set, new_nodes_alloc);
+      if (BE (new_nexts == NULL || new_indices == NULL
+	      || new_edests == NULL || new_eclosures == NULL, 0))
+	return -1;
+      dfa->nexts = new_nexts;
+      dfa->org_indices = new_indices;
+      dfa->edests = new_edests;
+      dfa->eclosures = new_eclosures;
+      dfa->nodes_alloc = new_nodes_alloc;
+    }
+  dfa->nodes[dfa->nodes_len] = token;
+  dfa->nodes[dfa->nodes_len].constraint = 0;
+#ifdef RE_ENABLE_I18N
+  dfa->nodes[dfa->nodes_len].accept_mb =
+    (token.type == OP_PERIOD && dfa->mb_cur_max > 1) || token.type == COMPLEX_BRACKET;
+#endif
+  dfa->nexts[dfa->nodes_len] = -1;
+  re_node_set_init_empty (dfa->edests + dfa->nodes_len);
+  re_node_set_init_empty (dfa->eclosures + dfa->nodes_len);
+  return dfa->nodes_len++;
+}
+
+static inline unsigned int
+internal_function
+calc_state_hash (const re_node_set *nodes, unsigned int context)
+{
+  unsigned int hash = nodes->nelem + context;
+  int i;
+  for (i = 0 ; i < nodes->nelem ; i++)
+    hash += nodes->elems[i];
+  return hash;
+}
+
+/* Search for the state whose node_set is equivalent to NODES.
+   Return the pointer to the state, if we found it in the DFA.
+   Otherwise create the new one and return it.  In case of an error
+   return NULL and set the error code in ERR.
+   Note: - We assume NULL as the invalid state, then it is possible that
+	   return value is NULL and ERR is REG_NOERROR.
+	 - We never return non-NULL value in case of any errors, it is for
+	   optimization.  */
+
+static re_dfastate_t *
+internal_function
+re_acquire_state (reg_errcode_t *err, const re_dfa_t *dfa,
+		  const re_node_set *nodes)
+{
+  unsigned int hash;
+  re_dfastate_t *new_state;
+  struct re_state_table_entry *spot;
+  int i;
+  if (BE (nodes->nelem == 0, 0))
+    {
+      *err = REG_NOERROR;
+      return NULL;
+    }
+  hash = calc_state_hash (nodes, 0);
+  spot = dfa->state_table + (hash & dfa->state_hash_mask);
+
+  for (i = 0 ; i < spot->num ; i++)
+    {
+      re_dfastate_t *state = spot->array[i];
+      if (hash != state->hash)
+	continue;
+      if (re_node_set_compare (&state->nodes, nodes))
+	return state;
+    }
+
+  /* There are no appropriate state in the dfa, create the new one.  */
+  new_state = create_ci_newstate (dfa, nodes, hash);
+  if (BE (new_state == NULL, 0))
+    *err = REG_ESPACE;
+
+  return new_state;
+}
+
+/* Search for the state whose node_set is equivalent to NODES and
+   whose context is equivalent to CONTEXT.
+   Return the pointer to the state, if we found it in the DFA.
+   Otherwise create the new one and return it.  In case of an error
+   return NULL and set the error code in ERR.
+   Note: - We assume NULL as the invalid state, then it is possible that
+	   return value is NULL and ERR is REG_NOERROR.
+	 - We never return non-NULL value in case of any errors, it is for
+	   optimization.  */
+
+static re_dfastate_t *
+internal_function
+re_acquire_state_context (reg_errcode_t *err, const re_dfa_t *dfa,
+			  const re_node_set *nodes, unsigned int context)
+{
+  unsigned int hash;
+  re_dfastate_t *new_state;
+  struct re_state_table_entry *spot;
+  int i;
+  if (nodes->nelem == 0)
+    {
+      *err = REG_NOERROR;
+      return NULL;
+    }
+  hash = calc_state_hash (nodes, context);
+  spot = dfa->state_table + (hash & dfa->state_hash_mask);
+
+  for (i = 0 ; i < spot->num ; i++)
+    {
+      re_dfastate_t *state = spot->array[i];
+      if (state->hash == hash
+	  && state->context == context
+	  && re_node_set_compare (state->entrance_nodes, nodes))
+	return state;
+    }
+  /* There are no appropriate state in `dfa', create the new one.  */
+  new_state = create_cd_newstate (dfa, nodes, context, hash);
+  if (BE (new_state == NULL, 0))
+    *err = REG_ESPACE;
+
+  return new_state;
+}
+
+/* Finish initialization of the new state NEWSTATE, and using its hash value
+   HASH put in the appropriate bucket of DFA's state table.  Return value
+   indicates the error code if failed.  */
+
+static reg_errcode_t
+register_state (const re_dfa_t *dfa, re_dfastate_t *newstate,
+		unsigned int hash)
+{
+  struct re_state_table_entry *spot;
+  reg_errcode_t err;
+  int i;
+
+  newstate->hash = hash;
+  err = re_node_set_alloc (&newstate->non_eps_nodes, newstate->nodes.nelem);
+  if (BE (err != REG_NOERROR, 0))
+    return REG_ESPACE;
+  for (i = 0; i < newstate->nodes.nelem; i++)
+    {
+      int elem = newstate->nodes.elems[i];
+      if (!IS_EPSILON_NODE (dfa->nodes[elem].type))
+	if (re_node_set_insert_last (&newstate->non_eps_nodes, elem) < 0)
+	  return REG_ESPACE;
+    }
+
+  spot = dfa->state_table + (hash & dfa->state_hash_mask);
+  if (BE (spot->alloc <= spot->num, 0))
+    {
+      int new_alloc = 2 * spot->num + 2;
+      re_dfastate_t **new_array = re_realloc (spot->array, re_dfastate_t *,
+					      new_alloc);
+      if (BE (new_array == NULL, 0))
+	return REG_ESPACE;
+      spot->array = new_array;
+      spot->alloc = new_alloc;
+    }
+  spot->array[spot->num++] = newstate;
+  return REG_NOERROR;
+}
+
+static void
+free_state (re_dfastate_t *state)
+{
+  re_node_set_free (&state->non_eps_nodes);
+  re_node_set_free (&state->inveclosure);
+  if (state->entrance_nodes != &state->nodes)
+    {
+      re_node_set_free (state->entrance_nodes);
+      re_free (state->entrance_nodes);
+    }
+  re_node_set_free (&state->nodes);
+  re_free (state->word_trtable);
+  re_free (state->trtable);
+  re_free (state);
+}
+
+/* Create the new state which is independ of contexts.
+   Return the new state if succeeded, otherwise return NULL.  */
+
+static re_dfastate_t *
+internal_function
+create_ci_newstate (const re_dfa_t *dfa, const re_node_set *nodes,
+		    unsigned int hash)
+{
+  int i;
+  reg_errcode_t err;
+  re_dfastate_t *newstate;
+
+  newstate = (re_dfastate_t *) calloc (sizeof (re_dfastate_t), 1);
+  if (BE (newstate == NULL, 0))
+    return NULL;
+  err = re_node_set_init_copy (&newstate->nodes, nodes);
+  if (BE (err != REG_NOERROR, 0))
+    {
+      re_free (newstate);
+      return NULL;
+    }
+
+  newstate->entrance_nodes = &newstate->nodes;
+  for (i = 0 ; i < nodes->nelem ; i++)
+    {
+      re_token_t *node = dfa->nodes + nodes->elems[i];
+      re_token_type_t type = node->type;
+      if (type == CHARACTER && !node->constraint)
+	continue;
+#ifdef RE_ENABLE_I18N
+      newstate->accept_mb |= node->accept_mb;
+#endif /* RE_ENABLE_I18N */
+
+      /* If the state has the halt node, the state is a halt state.  */
+      if (type == END_OF_RE)
+	newstate->halt = 1;
+      else if (type == OP_BACK_REF)
+	newstate->has_backref = 1;
+      else if (type == ANCHOR || node->constraint)
+	newstate->has_constraint = 1;
+    }
+  err = register_state (dfa, newstate, hash);
+  if (BE (err != REG_NOERROR, 0))
+    {
+      free_state (newstate);
+      newstate = NULL;
+    }
+  return newstate;
+}
+
+/* Create the new state which is depend on the context CONTEXT.
+   Return the new state if succeeded, otherwise return NULL.  */
+
+static re_dfastate_t *
+internal_function
+create_cd_newstate (const re_dfa_t *dfa, const re_node_set *nodes,
+		    unsigned int context, unsigned int hash)
+{
+  int i, nctx_nodes = 0;
+  reg_errcode_t err;
+  re_dfastate_t *newstate;
+
+  newstate = (re_dfastate_t *) calloc (sizeof (re_dfastate_t), 1);
+  if (BE (newstate == NULL, 0))
+    return NULL;
+  err = re_node_set_init_copy (&newstate->nodes, nodes);
+  if (BE (err != REG_NOERROR, 0))
+    {
+      re_free (newstate);
+      return NULL;
+    }
+
+  newstate->context = context;
+  newstate->entrance_nodes = &newstate->nodes;
+
+  for (i = 0 ; i < nodes->nelem ; i++)
+    {
+      re_token_t *node = dfa->nodes + nodes->elems[i];
+      re_token_type_t type = node->type;
+      unsigned int constraint = node->constraint;
+
+      if (type == CHARACTER && !constraint)
+	continue;
+#ifdef RE_ENABLE_I18N
+      newstate->accept_mb |= node->accept_mb;
+#endif /* RE_ENABLE_I18N */
+
+      /* If the state has the halt node, the state is a halt state.  */
+      if (type == END_OF_RE)
+	newstate->halt = 1;
+      else if (type == OP_BACK_REF)
+	newstate->has_backref = 1;
+
+      if (constraint)
+	{
+	  if (newstate->entrance_nodes == &newstate->nodes)
+	    {
+	      newstate->entrance_nodes = re_malloc (re_node_set, 1);
+	      if (BE (newstate->entrance_nodes == NULL, 0))
+		{
+		  free_state (newstate);
+		  return NULL;
+		}
+	      if (re_node_set_init_copy (newstate->entrance_nodes, nodes)
+		  != REG_NOERROR)
+		return NULL;
+	      nctx_nodes = 0;
+	      newstate->has_constraint = 1;
+	    }
+
+	  if (NOT_SATISFY_PREV_CONSTRAINT (constraint,context))
+	    {
+	      re_node_set_remove_at (&newstate->nodes, i - nctx_nodes);
+	      ++nctx_nodes;
+	    }
+	}
+    }
+  err = register_state (dfa, newstate, hash);
+  if (BE (err != REG_NOERROR, 0))
+    {
+      free_state (newstate);
+      newstate = NULL;
+    }
+  return  newstate;
+}

vendor/libgit2-sys/libgit2/deps/regex/regex_internal.h

diff --git a/vendor/libgit2-sys/libgit2/deps/regex/regex_internal.h b/vendor/libgit2-sys/libgit2/deps/regex/regex_internal.h
new file mode 100644
index 0000000..53ccebe
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/regex/regex_internal.h
@@ -0,0 +1,819 @@
+/* Extended regular expression matching and search library.
+   Copyright (C) 2002-2005, 2007, 2008, 2010 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#ifndef _REGEX_INTERNAL_H
+#define _REGEX_INTERNAL_H 1
+
+#include <assert.h>
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef UNUSED
+#	ifdef __GNUC__
+#		define UNUSED __attribute__((unused))
+#	else
+#		define UNUSED
+#	endif
+#endif
+
+#if defined HAVE_LANGINFO_H || defined HAVE_LANGINFO_CODESET || defined _LIBC
+# include <langinfo.h>
+#endif
+#if defined HAVE_LOCALE_H || defined _LIBC
+# include <locale.h>
+#endif
+#if defined HAVE_WCHAR_H || defined _LIBC
+# include <wchar.h>
+#endif /* HAVE_WCHAR_H || _LIBC */
+#if defined HAVE_WCTYPE_H || defined _LIBC
+# include <wctype.h>
+#endif /* HAVE_WCTYPE_H || _LIBC */
+#if defined HAVE_STDBOOL_H || defined _LIBC
+# include <stdbool.h>
+#endif /* HAVE_STDBOOL_H || _LIBC */
+#if !defined(ZOS_USS)
+#if defined HAVE_STDINT_H || defined _LIBC
+# include <stdint.h>
+#endif /* HAVE_STDINT_H || _LIBC */
+#endif /* !ZOS_USS */
+#if defined _LIBC
+# include <bits/libc-lock.h>
+#else
+# define __libc_lock_define(CLASS,NAME)
+# define __libc_lock_init(NAME) do { } while (0)
+# define __libc_lock_lock(NAME) do { } while (0)
+# define __libc_lock_unlock(NAME) do { } while (0)
+#endif
+
+#ifndef GAWK
+/* In case that the system doesn't have isblank().  */
+#if !defined _LIBC && !defined HAVE_ISBLANK && !defined isblank
+# define isblank(ch) ((ch) == ' ' || (ch) == '\t')
+#endif
+#else /* GAWK */
+/*
+ * This is a mess. On glibc systems you have to define
+ * a magic constant to get isblank() out of <ctype.h>, since it's
+ * a C99 function.  To heck with all that and borrow a page from
+ * dfa.c's book.
+ */
+
+static int
+is_blank (int c)
+{
+   return (c == ' ' || c == '\t');
+}
+#endif /* GAWK */
+
+#ifdef _LIBC
+# ifndef _RE_DEFINE_LOCALE_FUNCTIONS
+#  define _RE_DEFINE_LOCALE_FUNCTIONS 1
+#   include <locale/localeinfo.h>
+#   include <locale/elem-hash.h>
+#   include <locale/coll-lookup.h>
+# endif
+#endif
+
+/* This is for other GNU distributions with internationalized messages.  */
+#if (HAVE_LIBINTL_H && ENABLE_NLS) || defined _LIBC
+# include <libintl.h>
+# ifdef _LIBC
+#  undef gettext
+#  define gettext(msgid) \
+  INTUSE(__dcgettext) (_libc_intl_domainname, msgid, LC_MESSAGES)
+# endif
+#else
+# define gettext(msgid) (msgid)
+#endif
+
+#ifndef gettext_noop
+/* This define is so xgettext can find the internationalizable
+   strings.  */
+# define gettext_noop(String) String
+#endif
+
+/* For loser systems without the definition.  */
+#ifndef SIZE_MAX
+# define SIZE_MAX ((size_t) -1)
+#endif
+
+#ifndef NO_MBSUPPORT
+#include "mbsupport.h" /* gawk */
+#endif
+#ifndef MB_CUR_MAX
+#define MB_CUR_MAX 1
+#endif
+
+#if (defined MBS_SUPPORT) || _LIBC
+# define RE_ENABLE_I18N
+#endif
+
+#if __GNUC__ >= 3
+# define BE(expr, val) __builtin_expect (expr, val)
+#else
+# define BE(expr, val) (expr)
+# ifdef inline
+# undef inline
+# endif
+# define inline
+#endif
+
+/* Number of single byte character.  */
+#define SBC_MAX 256
+
+#define COLL_ELEM_LEN_MAX 8
+
+/* The character which represents newline.  */
+#define NEWLINE_CHAR '\n'
+#define WIDE_NEWLINE_CHAR L'\n'
+
+/* Rename to standard API for using out of glibc.  */
+#ifndef _LIBC
+# ifdef __wctype
+# undef __wctype
+# endif
+# define __wctype wctype
+# ifdef __iswctype
+# undef __iswctype
+# endif
+# define __iswctype iswctype
+# define __btowc btowc
+# define __mbrtowc mbrtowc
+#undef __mempcpy	/* GAWK */
+# define __mempcpy mempcpy
+# define __wcrtomb wcrtomb
+# define __regfree regfree
+# define attribute_hidden
+#endif /* not _LIBC */
+
+#ifdef __GNUC__
+# define __attribute(arg) __attribute__ (arg)
+#else
+# define __attribute(arg)
+#endif
+
+extern const char __re_error_msgid[] attribute_hidden;
+extern const size_t __re_error_msgid_idx[] attribute_hidden;
+
+/* An integer used to represent a set of bits.  It must be unsigned,
+   and must be at least as wide as unsigned int.  */
+typedef unsigned long int bitset_word_t;
+/* All bits set in a bitset_word_t.  */
+#define BITSET_WORD_MAX ULONG_MAX
+/* Number of bits in a bitset_word_t. Cast to int as most code use it
+ * like that for counting */
+#define BITSET_WORD_BITS ((int)(sizeof (bitset_word_t) * CHAR_BIT))
+/* Number of bitset_word_t in a bit_set.  */
+#define BITSET_WORDS (SBC_MAX / BITSET_WORD_BITS)
+typedef bitset_word_t bitset_t[BITSET_WORDS];
+typedef bitset_word_t *re_bitset_ptr_t;
+typedef const bitset_word_t *re_const_bitset_ptr_t;
+
+#define bitset_set(set,i) \
+  (set[i / BITSET_WORD_BITS] |= (bitset_word_t) 1 << i % BITSET_WORD_BITS)
+#define bitset_clear(set,i) \
+  (set[i / BITSET_WORD_BITS] &= ~((bitset_word_t) 1 << i % BITSET_WORD_BITS))
+#define bitset_contain(set,i) \
+  (set[i / BITSET_WORD_BITS] & ((bitset_word_t) 1 << i % BITSET_WORD_BITS))
+#define bitset_empty(set) memset (set, '\0', sizeof (bitset_t))
+#define bitset_set_all(set) memset (set, '\xff', sizeof (bitset_t))
+#define bitset_copy(dest,src) memcpy (dest, src, sizeof (bitset_t))
+
+#define PREV_WORD_CONSTRAINT 0x0001
+#define PREV_NOTWORD_CONSTRAINT 0x0002
+#define NEXT_WORD_CONSTRAINT 0x0004
+#define NEXT_NOTWORD_CONSTRAINT 0x0008
+#define PREV_NEWLINE_CONSTRAINT 0x0010
+#define NEXT_NEWLINE_CONSTRAINT 0x0020
+#define PREV_BEGBUF_CONSTRAINT 0x0040
+#define NEXT_ENDBUF_CONSTRAINT 0x0080
+#define WORD_DELIM_CONSTRAINT 0x0100
+#define NOT_WORD_DELIM_CONSTRAINT 0x0200
+
+typedef enum
+{
+  INSIDE_WORD = PREV_WORD_CONSTRAINT | NEXT_WORD_CONSTRAINT,
+  WORD_FIRST = PREV_NOTWORD_CONSTRAINT | NEXT_WORD_CONSTRAINT,
+  WORD_LAST = PREV_WORD_CONSTRAINT | NEXT_NOTWORD_CONSTRAINT,
+  INSIDE_NOTWORD = PREV_NOTWORD_CONSTRAINT | NEXT_NOTWORD_CONSTRAINT,
+  LINE_FIRST = PREV_NEWLINE_CONSTRAINT,
+  LINE_LAST = NEXT_NEWLINE_CONSTRAINT,
+  BUF_FIRST = PREV_BEGBUF_CONSTRAINT,
+  BUF_LAST = NEXT_ENDBUF_CONSTRAINT,
+  WORD_DELIM = WORD_DELIM_CONSTRAINT,
+  NOT_WORD_DELIM = NOT_WORD_DELIM_CONSTRAINT
+} re_context_type;
+
+typedef struct
+{
+  int alloc;
+  int nelem;
+  int *elems;
+} re_node_set;
+
+typedef enum
+{
+  NON_TYPE = 0,
+
+  /* Node type, These are used by token, node, tree.  */
+  CHARACTER = 1,
+  END_OF_RE = 2,
+  SIMPLE_BRACKET = 3,
+  OP_BACK_REF = 4,
+  OP_PERIOD = 5,
+#ifdef RE_ENABLE_I18N
+  COMPLEX_BRACKET = 6,
+  OP_UTF8_PERIOD = 7,
+#endif /* RE_ENABLE_I18N */
+
+  /* We define EPSILON_BIT as a macro so that OP_OPEN_SUBEXP is used
+     when the debugger shows values of this enum type.  */
+#define EPSILON_BIT 8
+  OP_OPEN_SUBEXP = EPSILON_BIT | 0,
+  OP_CLOSE_SUBEXP = EPSILON_BIT | 1,
+  OP_ALT = EPSILON_BIT | 2,
+  OP_DUP_ASTERISK = EPSILON_BIT | 3,
+  ANCHOR = EPSILON_BIT | 4,
+
+  /* Tree type, these are used only by tree. */
+  CONCAT = 16,
+  SUBEXP = 17,
+
+  /* Token type, these are used only by token.  */
+  OP_DUP_PLUS = 18,
+  OP_DUP_QUESTION,
+  OP_OPEN_BRACKET,
+  OP_CLOSE_BRACKET,
+  OP_CHARSET_RANGE,
+  OP_OPEN_DUP_NUM,
+  OP_CLOSE_DUP_NUM,
+  OP_NON_MATCH_LIST,
+  OP_OPEN_COLL_ELEM,
+  OP_CLOSE_COLL_ELEM,
+  OP_OPEN_EQUIV_CLASS,
+  OP_CLOSE_EQUIV_CLASS,
+  OP_OPEN_CHAR_CLASS,
+  OP_CLOSE_CHAR_CLASS,
+  OP_WORD,
+  OP_NOTWORD,
+  OP_SPACE,
+  OP_NOTSPACE,
+  BACK_SLASH
+
+} re_token_type_t;
+
+#ifdef RE_ENABLE_I18N
+typedef struct
+{
+  /* Multibyte characters.  */
+  wchar_t *mbchars;
+
+  /* Collating symbols.  */
+# ifdef _LIBC
+  int32_t *coll_syms;
+# endif
+
+  /* Equivalence classes. */
+# ifdef _LIBC
+  int32_t *equiv_classes;
+# endif
+
+  /* Range expressions. */
+# ifdef _LIBC
+  uint32_t *range_starts;
+  uint32_t *range_ends;
+# else /* not _LIBC */
+  wchar_t *range_starts;
+  wchar_t *range_ends;
+# endif /* not _LIBC */
+
+  /* Character classes. */
+  wctype_t *char_classes;
+
+  /* If this character set is the non-matching list.  */
+  unsigned int non_match : 1;
+
+  /* # of multibyte characters.  */
+  int nmbchars;
+
+  /* # of collating symbols.  */
+  int ncoll_syms;
+
+  /* # of equivalence classes. */
+  int nequiv_classes;
+
+  /* # of range expressions. */
+  int nranges;
+
+  /* # of character classes. */
+  int nchar_classes;
+} re_charset_t;
+#endif /* RE_ENABLE_I18N */
+
+typedef struct
+{
+  union
+  {
+    unsigned char c;		/* for CHARACTER */
+    re_bitset_ptr_t sbcset;	/* for SIMPLE_BRACKET */
+#ifdef RE_ENABLE_I18N
+    re_charset_t *mbcset;	/* for COMPLEX_BRACKET */
+#endif /* RE_ENABLE_I18N */
+    int idx;			/* for BACK_REF */
+    re_context_type ctx_type;	/* for ANCHOR */
+  } opr;
+#if __GNUC__ >= 2
+  re_token_type_t type : 8;
+#else
+  re_token_type_t type;
+#endif
+  unsigned int constraint : 10;	/* context constraint */
+  unsigned int duplicated : 1;
+  unsigned int opt_subexp : 1;
+#ifdef RE_ENABLE_I18N
+  unsigned int accept_mb : 1;
+  /* These 2 bits can be moved into the union if needed (e.g. if running out
+     of bits; move opr.c to opr.c.c and move the flags to opr.c.flags).  */
+  unsigned int mb_partial : 1;
+#endif
+  unsigned int word_char : 1;
+} re_token_t;
+
+#define IS_EPSILON_NODE(type) ((type) & EPSILON_BIT)
+
+struct re_string_t
+{
+  /* Indicate the raw buffer which is the original string passed as an
+     argument of regexec(), re_search(), etc..  */
+  const unsigned char *raw_mbs;
+  /* Store the multibyte string.  In case of "case insensitive mode" like
+     REG_ICASE, upper cases of the string are stored, otherwise MBS points
+     the same address that RAW_MBS points.  */
+  unsigned char *mbs;
+#ifdef RE_ENABLE_I18N
+  /* Store the wide character string which is corresponding to MBS.  */
+  wint_t *wcs;
+  int *offsets;
+  mbstate_t cur_state;
+#endif
+  /* Index in RAW_MBS.  Each character mbs[i] corresponds to
+     raw_mbs[raw_mbs_idx + i].  */
+  int raw_mbs_idx;
+  /* The length of the valid characters in the buffers.  */
+  int valid_len;
+  /* The corresponding number of bytes in raw_mbs array.  */
+  int valid_raw_len;
+  /* The length of the buffers MBS and WCS.  */
+  int bufs_len;
+  /* The index in MBS, which is updated by re_string_fetch_byte.  */
+  int cur_idx;
+  /* length of RAW_MBS array.  */
+  int raw_len;
+  /* This is RAW_LEN - RAW_MBS_IDX + VALID_LEN - VALID_RAW_LEN.  */
+  int len;
+  /* End of the buffer may be shorter than its length in the cases such
+     as re_match_2, re_search_2.  Then, we use STOP for end of the buffer
+     instead of LEN.  */
+  int raw_stop;
+  /* This is RAW_STOP - RAW_MBS_IDX adjusted through OFFSETS.  */
+  int stop;
+
+  /* The context of mbs[0].  We store the context independently, since
+     the context of mbs[0] may be different from raw_mbs[0], which is
+     the beginning of the input string.  */
+  unsigned int tip_context;
+  /* The translation passed as a part of an argument of re_compile_pattern.  */
+  RE_TRANSLATE_TYPE trans;
+  /* Copy of re_dfa_t's word_char.  */
+  re_const_bitset_ptr_t word_char;
+  /* 1 if REG_ICASE.  */
+  unsigned char icase;
+  unsigned char is_utf8;
+  unsigned char map_notascii;
+  unsigned char mbs_allocated;
+  unsigned char offsets_needed;
+  unsigned char newline_anchor;
+  unsigned char word_ops_used;
+  int mb_cur_max;
+};
+typedef struct re_string_t re_string_t;
+
+
+struct re_dfa_t;
+typedef struct re_dfa_t re_dfa_t;
+
+#ifndef _LIBC
+# ifdef __i386__
+#  define internal_function   __attribute ((regparm (3), stdcall))
+# else
+#  define internal_function
+# endif
+#endif
+
+#ifndef NOT_IN_libc
+static reg_errcode_t re_string_realloc_buffers (re_string_t *pstr,
+						int new_buf_len)
+     internal_function;
+# ifdef RE_ENABLE_I18N
+static void build_wcs_buffer (re_string_t *pstr) internal_function;
+static reg_errcode_t build_wcs_upper_buffer (re_string_t *pstr)
+  internal_function;
+# endif /* RE_ENABLE_I18N */
+static void build_upper_buffer (re_string_t *pstr) internal_function;
+static void re_string_translate_buffer (re_string_t *pstr) internal_function;
+static unsigned int re_string_context_at (const re_string_t *input, int idx,
+					  int eflags)
+     internal_function __attribute ((pure));
+#endif
+#define re_string_peek_byte(pstr, offset) \
+  ((pstr)->mbs[(pstr)->cur_idx + offset])
+#define re_string_fetch_byte(pstr) \
+  ((pstr)->mbs[(pstr)->cur_idx++])
+#define re_string_first_byte(pstr, idx) \
+  ((idx) == (pstr)->valid_len || (pstr)->wcs[idx] != WEOF)
+#define re_string_is_single_byte_char(pstr, idx) \
+  ((pstr)->wcs[idx] != WEOF && ((pstr)->valid_len == (idx) + 1 \
+				|| (pstr)->wcs[(idx) + 1] != WEOF))
+#define re_string_eoi(pstr) ((pstr)->stop <= (pstr)->cur_idx)
+#define re_string_cur_idx(pstr) ((pstr)->cur_idx)
+#define re_string_get_buffer(pstr) ((pstr)->mbs)
+#define re_string_length(pstr) ((pstr)->len)
+#define re_string_byte_at(pstr,idx) ((pstr)->mbs[idx])
+#define re_string_skip_bytes(pstr,idx) ((pstr)->cur_idx += (idx))
+#define re_string_set_index(pstr,idx) ((pstr)->cur_idx = (idx))
+
+#ifndef _LIBC
+# if HAVE_ALLOCA
+#  if (_MSC_VER)
+#   include <malloc.h>
+#   define __libc_use_alloca(n) 0
+#  else
+#   include <alloca.h>
+/* The OS usually guarantees only one guard page at the bottom of the stack,
+   and a page size can be as small as 4096 bytes.  So we cannot safely
+   allocate anything larger than 4096 bytes.  Also care for the possibility
+   of a few compiler-allocated temporary stack slots.  */
+#  define __libc_use_alloca(n) ((n) < 4032)
+#  endif
+# else
+/* alloca is implemented with malloc, so just use malloc.  */
+#  define __libc_use_alloca(n) 0
+# endif
+#endif
+
+#define re_malloc(t,n) ((t *) malloc ((n) * sizeof (t)))
+/* SunOS 4.1.x realloc doesn't accept null pointers: pre-Standard C. Sigh. */
+#define re_realloc(p,t,n) ((p != NULL) ? (t *) realloc (p,(n)*sizeof(t)) : (t *) calloc(n,sizeof(t)))
+#define re_free(p) free (p)
+
+struct bin_tree_t
+{
+  struct bin_tree_t *parent;
+  struct bin_tree_t *left;
+  struct bin_tree_t *right;
+  struct bin_tree_t *first;
+  struct bin_tree_t *next;
+
+  re_token_t token;
+
+  /* `node_idx' is the index in dfa->nodes, if `type' == 0.
+     Otherwise `type' indicate the type of this node.  */
+  int node_idx;
+};
+typedef struct bin_tree_t bin_tree_t;
+
+#define BIN_TREE_STORAGE_SIZE \
+  ((1024 - sizeof (void *)) / sizeof (bin_tree_t))
+
+struct bin_tree_storage_t
+{
+  struct bin_tree_storage_t *next;
+  bin_tree_t data[BIN_TREE_STORAGE_SIZE];
+};
+typedef struct bin_tree_storage_t bin_tree_storage_t;
+
+#define CONTEXT_WORD 1
+#define CONTEXT_NEWLINE (CONTEXT_WORD << 1)
+#define CONTEXT_BEGBUF (CONTEXT_NEWLINE << 1)
+#define CONTEXT_ENDBUF (CONTEXT_BEGBUF << 1)
+
+#define IS_WORD_CONTEXT(c) ((c) & CONTEXT_WORD)
+#define IS_NEWLINE_CONTEXT(c) ((c) & CONTEXT_NEWLINE)
+#define IS_BEGBUF_CONTEXT(c) ((c) & CONTEXT_BEGBUF)
+#define IS_ENDBUF_CONTEXT(c) ((c) & CONTEXT_ENDBUF)
+#define IS_ORDINARY_CONTEXT(c) ((c) == 0)
+
+#define IS_WORD_CHAR(ch) (isalnum (ch) || (ch) == '_')
+#define IS_NEWLINE(ch) ((ch) == NEWLINE_CHAR)
+#define IS_WIDE_WORD_CHAR(ch) (iswalnum (ch) || (ch) == L'_')
+#define IS_WIDE_NEWLINE(ch) ((ch) == WIDE_NEWLINE_CHAR)
+
+#define NOT_SATISFY_PREV_CONSTRAINT(constraint,context) \
+ ((((constraint) & PREV_WORD_CONSTRAINT) && !IS_WORD_CONTEXT (context)) \
+  || ((constraint & PREV_NOTWORD_CONSTRAINT) && IS_WORD_CONTEXT (context)) \
+  || ((constraint & PREV_NEWLINE_CONSTRAINT) && !IS_NEWLINE_CONTEXT (context))\
+  || ((constraint & PREV_BEGBUF_CONSTRAINT) && !IS_BEGBUF_CONTEXT (context)))
+
+#define NOT_SATISFY_NEXT_CONSTRAINT(constraint,context) \
+ ((((constraint) & NEXT_WORD_CONSTRAINT) && !IS_WORD_CONTEXT (context)) \
+  || (((constraint) & NEXT_NOTWORD_CONSTRAINT) && IS_WORD_CONTEXT (context)) \
+  || (((constraint) & NEXT_NEWLINE_CONSTRAINT) && !IS_NEWLINE_CONTEXT (context)) \
+  || (((constraint) & NEXT_ENDBUF_CONSTRAINT) && !IS_ENDBUF_CONTEXT (context)))
+
+struct re_dfastate_t
+{
+  unsigned int hash;
+  re_node_set nodes;
+  re_node_set non_eps_nodes;
+  re_node_set inveclosure;
+  re_node_set *entrance_nodes;
+  struct re_dfastate_t **trtable, **word_trtable;
+  unsigned int context : 4;
+  unsigned int halt : 1;
+  /* If this state can accept `multi byte'.
+     Note that we refer to multibyte characters, and multi character
+     collating elements as `multi byte'.  */
+  unsigned int accept_mb : 1;
+  /* If this state has backreference node(s).  */
+  unsigned int has_backref : 1;
+  unsigned int has_constraint : 1;
+};
+typedef struct re_dfastate_t re_dfastate_t;
+
+struct re_state_table_entry
+{
+  int num;
+  int alloc;
+  re_dfastate_t **array;
+};
+
+/* Array type used in re_sub_match_last_t and re_sub_match_top_t.  */
+
+typedef struct
+{
+  int next_idx;
+  int alloc;
+  re_dfastate_t **array;
+} state_array_t;
+
+/* Store information about the node NODE whose type is OP_CLOSE_SUBEXP.  */
+
+typedef struct
+{
+  int node;
+  int str_idx; /* The position NODE match at.  */
+  state_array_t path;
+} re_sub_match_last_t;
+
+/* Store information about the node NODE whose type is OP_OPEN_SUBEXP.
+   And information about the node, whose type is OP_CLOSE_SUBEXP,
+   corresponding to NODE is stored in LASTS.  */
+
+typedef struct
+{
+  int str_idx;
+  int node;
+  state_array_t *path;
+  int alasts; /* Allocation size of LASTS.  */
+  int nlasts; /* The number of LASTS.  */
+  re_sub_match_last_t **lasts;
+} re_sub_match_top_t;
+
+struct re_backref_cache_entry
+{
+  int node;
+  int str_idx;
+  int subexp_from;
+  int subexp_to;
+  char more;
+  char unused;
+  unsigned short int eps_reachable_subexps_map;
+};
+
+typedef struct
+{
+  /* The string object corresponding to the input string.  */
+  re_string_t input;
+#if defined _LIBC || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)
+  const re_dfa_t *const dfa;
+#else
+  const re_dfa_t *dfa;
+#endif
+  /* EFLAGS of the argument of regexec.  */
+  int eflags;
+  /* Where the matching ends.  */
+  int match_last;
+  int last_node;
+  /* The state log used by the matcher.  */
+  re_dfastate_t **state_log;
+  int state_log_top;
+  /* Back reference cache.  */
+  int nbkref_ents;
+  int abkref_ents;
+  struct re_backref_cache_entry *bkref_ents;
+  int max_mb_elem_len;
+  int nsub_tops;
+  int asub_tops;
+  re_sub_match_top_t **sub_tops;
+} re_match_context_t;
+
+typedef struct
+{
+  re_dfastate_t **sifted_states;
+  re_dfastate_t **limited_states;
+  int last_node;
+  int last_str_idx;
+  re_node_set limits;
+} re_sift_context_t;
+
+struct re_fail_stack_ent_t
+{
+  int idx;
+  int node;
+  regmatch_t *regs;
+  re_node_set eps_via_nodes;
+};
+
+struct re_fail_stack_t
+{
+  int num;
+  int alloc;
+  struct re_fail_stack_ent_t *stack;
+};
+
+struct re_dfa_t
+{
+  re_token_t *nodes;
+  size_t nodes_alloc;
+  size_t nodes_len;
+  int *nexts;
+  int *org_indices;
+  re_node_set *edests;
+  re_node_set *eclosures;
+  re_node_set *inveclosures;
+  struct re_state_table_entry *state_table;
+  re_dfastate_t *init_state;
+  re_dfastate_t *init_state_word;
+  re_dfastate_t *init_state_nl;
+  re_dfastate_t *init_state_begbuf;
+  bin_tree_t *str_tree;
+  bin_tree_storage_t *str_tree_storage;
+  re_bitset_ptr_t sb_char;
+  int str_tree_storage_idx;
+
+  /* number of subexpressions `re_nsub' is in regex_t.  */
+  unsigned int state_hash_mask;
+  int init_node;
+  int nbackref; /* The number of backreference in this dfa.  */
+
+  /* Bitmap expressing which backreference is used.  */
+  bitset_word_t used_bkref_map;
+  bitset_word_t completed_bkref_map;
+
+  unsigned int has_plural_match : 1;
+  /* If this dfa has "multibyte node", which is a backreference or
+     a node which can accept multibyte character or multi character
+     collating element.  */
+  unsigned int has_mb_node : 1;
+  unsigned int is_utf8 : 1;
+  unsigned int map_notascii : 1;
+  unsigned int word_ops_used : 1;
+  int mb_cur_max;
+  bitset_t word_char;
+  reg_syntax_t syntax;
+  int *subexp_map;
+#ifdef DEBUG
+  char* re_str;
+#endif
+#if defined _LIBC
+  __libc_lock_define (, lock)
+#endif
+};
+
+#define re_node_set_init_empty(set) memset (set, '\0', sizeof (re_node_set))
+#define re_node_set_remove(set,id) \
+  (re_node_set_remove_at (set, re_node_set_contains (set, id) - 1))
+#define re_node_set_empty(p) ((p)->nelem = 0)
+#define re_node_set_free(set) re_free ((set)->elems)
+
+
+typedef enum
+{
+  SB_CHAR,
+  MB_CHAR,
+  EQUIV_CLASS,
+  COLL_SYM,
+  CHAR_CLASS
+} bracket_elem_type;
+
+typedef struct
+{
+  bracket_elem_type type;
+  union
+  {
+    unsigned char ch;
+    unsigned char *name;
+    wchar_t wch;
+  } opr;
+} bracket_elem_t;
+
+
+/* Inline functions for bitset operation.  */
+static inline void
+bitset_not (bitset_t set)
+{
+  int bitset_i;
+  for (bitset_i = 0; bitset_i < BITSET_WORDS; ++bitset_i)
+    set[bitset_i] = ~set[bitset_i];
+}
+
+static inline void
+bitset_merge (bitset_t dest, const bitset_t src)
+{
+  int bitset_i;
+  for (bitset_i = 0; bitset_i < BITSET_WORDS; ++bitset_i)
+    dest[bitset_i] |= src[bitset_i];
+}
+
+static inline void
+bitset_mask (bitset_t dest, const bitset_t src)
+{
+  int bitset_i;
+  for (bitset_i = 0; bitset_i < BITSET_WORDS; ++bitset_i)
+    dest[bitset_i] &= src[bitset_i];
+}
+
+#ifdef RE_ENABLE_I18N
+/* Inline functions for re_string.  */
+static inline int
+internal_function __attribute ((pure))
+re_string_char_size_at (const re_string_t *pstr, int idx)
+{
+  int byte_idx;
+  if (pstr->mb_cur_max == 1)
+    return 1;
+  for (byte_idx = 1; idx + byte_idx < pstr->valid_len; ++byte_idx)
+    if (pstr->wcs[idx + byte_idx] != WEOF)
+      break;
+  return byte_idx;
+}
+
+static inline wint_t
+internal_function __attribute ((pure))
+re_string_wchar_at (const re_string_t *pstr, int idx)
+{
+  if (pstr->mb_cur_max == 1)
+    return (wint_t) pstr->mbs[idx];
+  return (wint_t) pstr->wcs[idx];
+}
+
+# ifndef NOT_IN_libc
+static int
+internal_function __attribute ((pure))
+re_string_elem_size_at (const re_string_t *pstr, int idx)
+{
+#  ifdef _LIBC
+  const unsigned char *p, *extra;
+  const int32_t *table, *indirect;
+  int32_t tmp;
+#   include <locale/weight.h>
+  uint_fast32_t nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+
+  if (nrules != 0)
+    {
+      table = (const int32_t *) _NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEMB);
+      extra = (const unsigned char *)
+	_NL_CURRENT (LC_COLLATE, _NL_COLLATE_EXTRAMB);
+      indirect = (const int32_t *) _NL_CURRENT (LC_COLLATE,
+						_NL_COLLATE_INDIRECTMB);
+      p = pstr->mbs + idx;
+      tmp = findidx (&p);
+      return p - pstr->mbs - idx;
+    }
+  else
+#  endif /* _LIBC */
+    return 1;
+}
+# endif
+#endif /* RE_ENABLE_I18N */
+
+#endif /*  _REGEX_INTERNAL_H */

vendor/libgit2-sys/libgit2/deps/regex/regexec.c

diff --git a/vendor/libgit2-sys/libgit2/deps/regex/regexec.c b/vendor/libgit2-sys/libgit2/deps/regex/regexec.c
new file mode 100644
index 0000000..0a1602e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/regex/regexec.c
@@ -0,0 +1,4369 @@
+/* Extended regular expression matching and search library.
+   Copyright (C) 2002-2005, 2007, 2009, 2010 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301 USA.  */
+
+static reg_errcode_t match_ctx_init (re_match_context_t *cache, int eflags,
+				     int n) internal_function;
+static void match_ctx_clean (re_match_context_t *mctx) internal_function;
+static void match_ctx_free (re_match_context_t *cache) internal_function;
+static reg_errcode_t match_ctx_add_entry (re_match_context_t *cache, int node,
+					  int str_idx, int from, int to)
+     internal_function;
+static int search_cur_bkref_entry (const re_match_context_t *mctx, int str_idx)
+     internal_function;
+static reg_errcode_t match_ctx_add_subtop (re_match_context_t *mctx, int node,
+					   int str_idx) internal_function;
+static re_sub_match_last_t * match_ctx_add_sublast (re_sub_match_top_t *subtop,
+						   int node, int str_idx)
+     internal_function;
+static void sift_ctx_init (re_sift_context_t *sctx, re_dfastate_t **sifted_sts,
+			   re_dfastate_t **limited_sts, int last_node,
+			   int last_str_idx)
+     internal_function;
+static reg_errcode_t re_search_internal (const regex_t *preg,
+					 const char *string, int length,
+					 int start, int range, int stop,
+					 size_t nmatch, regmatch_t pmatch[],
+					 int eflags);
+static int re_search_2_stub (struct re_pattern_buffer *bufp,
+			     const char *string1, int length1,
+			     const char *string2, int length2,
+			     int start, int range, struct re_registers *regs,
+			     int stop, int ret_len);
+static int re_search_stub (struct re_pattern_buffer *bufp,
+			   const char *string, int length, int start,
+			   int range, int stop, struct re_registers *regs,
+			   int ret_len);
+static unsigned re_copy_regs (struct re_registers *regs, regmatch_t *pmatch,
+			      unsigned int nregs, int regs_allocated);
+static reg_errcode_t prune_impossible_nodes (re_match_context_t *mctx);
+static int check_matching (re_match_context_t *mctx, int fl_longest_match,
+			   int *p_match_first) internal_function;
+static int check_halt_state_context (const re_match_context_t *mctx,
+				     const re_dfastate_t *state, int idx)
+     internal_function;
+static void update_regs (const re_dfa_t *dfa, regmatch_t *pmatch,
+			 regmatch_t *prev_idx_match, int cur_node,
+			 int cur_idx, int nmatch) internal_function;
+static reg_errcode_t push_fail_stack (struct re_fail_stack_t *fs,
+				      int str_idx, int dest_node, int nregs,
+				      regmatch_t *regs,
+				      re_node_set *eps_via_nodes)
+     internal_function;
+static reg_errcode_t set_regs (const regex_t *preg,
+			       const re_match_context_t *mctx,
+			       size_t nmatch, regmatch_t *pmatch,
+			       int fl_backtrack) internal_function;
+static reg_errcode_t free_fail_stack_return (struct re_fail_stack_t *fs)
+     internal_function;
+
+#ifdef RE_ENABLE_I18N
+static int sift_states_iter_mb (const re_match_context_t *mctx,
+				re_sift_context_t *sctx,
+				int node_idx, int str_idx, int max_str_idx)
+     internal_function;
+#endif /* RE_ENABLE_I18N */
+static reg_errcode_t sift_states_backward (const re_match_context_t *mctx,
+					   re_sift_context_t *sctx)
+     internal_function;
+static reg_errcode_t build_sifted_states (const re_match_context_t *mctx,
+					  re_sift_context_t *sctx, int str_idx,
+					  re_node_set *cur_dest)
+     internal_function;
+static reg_errcode_t update_cur_sifted_state (const re_match_context_t *mctx,
+					      re_sift_context_t *sctx,
+					      int str_idx,
+					      re_node_set *dest_nodes)
+     internal_function;
+static reg_errcode_t add_epsilon_src_nodes (const re_dfa_t *dfa,
+					    re_node_set *dest_nodes,
+					    const re_node_set *candidates)
+     internal_function;
+static int check_dst_limits (const re_match_context_t *mctx,
+			     re_node_set *limits,
+			     int dst_node, int dst_idx, int src_node,
+			     int src_idx) internal_function;
+static int check_dst_limits_calc_pos_1 (const re_match_context_t *mctx,
+					int boundaries, int subexp_idx,
+					int from_node, int bkref_idx)
+     internal_function;
+static int check_dst_limits_calc_pos (const re_match_context_t *mctx,
+				      int limit, int subexp_idx,
+				      int node, int str_idx,
+				      int bkref_idx) internal_function;
+static reg_errcode_t check_subexp_limits (const re_dfa_t *dfa,
+					  re_node_set *dest_nodes,
+					  const re_node_set *candidates,
+					  re_node_set *limits,
+					  struct re_backref_cache_entry *bkref_ents,
+					  int str_idx) internal_function;
+static reg_errcode_t sift_states_bkref (const re_match_context_t *mctx,
+					re_sift_context_t *sctx,
+					int str_idx, const re_node_set *candidates)
+     internal_function;
+static reg_errcode_t merge_state_array (const re_dfa_t *dfa,
+					re_dfastate_t **dst,
+					re_dfastate_t **src, int num)
+     internal_function;
+static re_dfastate_t *find_recover_state (reg_errcode_t *err,
+					 re_match_context_t *mctx) internal_function;
+static re_dfastate_t *transit_state (reg_errcode_t *err,
+				     re_match_context_t *mctx,
+				     re_dfastate_t *state) internal_function;
+static re_dfastate_t *merge_state_with_log (reg_errcode_t *err,
+					    re_match_context_t *mctx,
+					    re_dfastate_t *next_state)
+     internal_function;
+static reg_errcode_t check_subexp_matching_top (re_match_context_t *mctx,
+						re_node_set *cur_nodes,
+						int str_idx) internal_function;
+#if 0
+static re_dfastate_t *transit_state_sb (reg_errcode_t *err,
+					re_match_context_t *mctx,
+					re_dfastate_t *pstate)
+     internal_function;
+#endif
+#ifdef RE_ENABLE_I18N
+static reg_errcode_t transit_state_mb (re_match_context_t *mctx,
+				       re_dfastate_t *pstate)
+     internal_function;
+#endif /* RE_ENABLE_I18N */
+static reg_errcode_t transit_state_bkref (re_match_context_t *mctx,
+					  const re_node_set *nodes)
+     internal_function;
+static reg_errcode_t get_subexp (re_match_context_t *mctx,
+				 int bkref_node, int bkref_str_idx)
+     internal_function;
+static reg_errcode_t get_subexp_sub (re_match_context_t *mctx,
+				     const re_sub_match_top_t *sub_top,
+				     re_sub_match_last_t *sub_last,
+				     int bkref_node, int bkref_str)
+     internal_function;
+static int find_subexp_node (const re_dfa_t *dfa, const re_node_set *nodes,
+			     int subexp_idx, int type) internal_function;
+static reg_errcode_t check_arrival (re_match_context_t *mctx,
+				    state_array_t *path, int top_node,
+				    int top_str, int last_node, int last_str,
+				    int type) internal_function;
+static reg_errcode_t check_arrival_add_next_nodes (re_match_context_t *mctx,
+						   int str_idx,
+						   re_node_set *cur_nodes,
+						   re_node_set *next_nodes)
+     internal_function;
+static reg_errcode_t check_arrival_expand_ecl (const re_dfa_t *dfa,
+					       re_node_set *cur_nodes,
+					       int ex_subexp, int type)
+     internal_function;
+static reg_errcode_t check_arrival_expand_ecl_sub (const re_dfa_t *dfa,
+						   re_node_set *dst_nodes,
+						   int target, int ex_subexp,
+						   int type) internal_function;
+static reg_errcode_t expand_bkref_cache (re_match_context_t *mctx,
+					 re_node_set *cur_nodes, int cur_str,
+					 int subexp_num, int type)
+     internal_function;
+static int build_trtable (const re_dfa_t *dfa,
+			  re_dfastate_t *state) internal_function;
+#ifdef RE_ENABLE_I18N
+static int check_node_accept_bytes (const re_dfa_t *dfa, int node_idx,
+				    const re_string_t *input, int idx)
+     internal_function;
+# ifdef _LIBC
+static unsigned int find_collation_sequence_value (const unsigned char *mbs,
+						   size_t name_len)
+     internal_function;
+# endif /* _LIBC */
+#endif /* RE_ENABLE_I18N */
+static int group_nodes_into_DFAstates (const re_dfa_t *dfa,
+				       const re_dfastate_t *state,
+				       re_node_set *states_node,
+				       bitset_t *states_ch) internal_function;
+static int check_node_accept (const re_match_context_t *mctx,
+			      const re_token_t *node, int idx)
+     internal_function;
+static reg_errcode_t extend_buffers (re_match_context_t *mctx)
+     internal_function;
+
+/* Entry point for POSIX code.  */
+
+/* regexec searches for a given pattern, specified by PREG, in the
+   string STRING.
+
+   If NMATCH is zero or REG_NOSUB was set in the cflags argument to
+   `regcomp', we ignore PMATCH.  Otherwise, we assume PMATCH has at
+   least NMATCH elements, and we set them to the offsets of the
+   corresponding matched substrings.
+
+   EFLAGS specifies `execution flags' which affect matching: if
+   REG_NOTBOL is set, then ^ does not match at the beginning of the
+   string; if REG_NOTEOL is set, then $ does not match at the end.
+
+   We return 0 if we find a match and REG_NOMATCH if not.  */
+
+int
+regexec (
+	const regex_t *__restrict preg,
+	const char *__restrict string,
+	size_t nmatch,
+	regmatch_t pmatch[],
+	int eflags)
+{
+  reg_errcode_t err;
+  int start, length;
+
+  if (eflags & ~(REG_NOTBOL | REG_NOTEOL | REG_STARTEND))
+    return REG_BADPAT;
+
+  if (eflags & REG_STARTEND)
+    {
+      start = pmatch[0].rm_so;
+      length = pmatch[0].rm_eo;
+    }
+  else
+    {
+      start = 0;
+      length = strlen (string);
+    }
+
+  __libc_lock_lock (dfa->lock);
+  if (preg->no_sub)
+    err = re_search_internal (preg, string, length, start, length - start,
+			      length, 0, NULL, eflags);
+  else
+    err = re_search_internal (preg, string, length, start, length - start,
+			      length, nmatch, pmatch, eflags);
+  __libc_lock_unlock (dfa->lock);
+  return err != REG_NOERROR;
+}
+
+#ifdef _LIBC
+# include <shlib-compat.h>
+versioned_symbol (libc, __regexec, regexec, GLIBC_2_3_4);
+
+# if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_3_4)
+__typeof__ (__regexec) __compat_regexec;
+
+int
+attribute_compat_text_section
+__compat_regexec (const regex_t *__restrict preg,
+		  const char *__restrict string, size_t nmatch,
+		  regmatch_t pmatch[], int eflags)
+{
+  return regexec (preg, string, nmatch, pmatch,
+		  eflags & (REG_NOTBOL | REG_NOTEOL));
+}
+compat_symbol (libc, __compat_regexec, regexec, GLIBC_2_0);
+# endif
+#endif
+
+/* Entry points for GNU code.  */
+
+/* re_match, re_search, re_match_2, re_search_2
+
+   The former two functions operate on STRING with length LENGTH,
+   while the later two operate on concatenation of STRING1 and STRING2
+   with lengths LENGTH1 and LENGTH2, respectively.
+
+   re_match() matches the compiled pattern in BUFP against the string,
+   starting at index START.
+
+   re_search() first tries matching at index START, then it tries to match
+   starting from index START + 1, and so on.  The last start position tried
+   is START + RANGE.  (Thus RANGE = 0 forces re_search to operate the same
+   way as re_match().)
+
+   The parameter STOP of re_{match,search}_2 specifies that no match exceeding
+   the first STOP characters of the concatenation of the strings should be
+   concerned.
+
+   If REGS is not NULL, and BUFP->no_sub is not set, the offsets of the match
+   and all groups is stroed in REGS.  (For the "_2" variants, the offsets are
+   computed relative to the concatenation, not relative to the individual
+   strings.)
+
+   On success, re_match* functions return the length of the match, re_search*
+   return the position of the start of the match.  Return value -1 means no
+   match was found and -2 indicates an internal error.  */
+
+int
+re_match (struct re_pattern_buffer *bufp,
+	  const char *string,
+	  int length,
+	  int start,
+	  struct re_registers *regs)
+{
+  return re_search_stub (bufp, string, length, start, 0, length, regs, 1);
+}
+#ifdef _LIBC
+weak_alias (__re_match, re_match)
+#endif
+
+int
+re_search (struct re_pattern_buffer *bufp,
+	   const char *string,
+	   int length, int start, int range,
+	   struct re_registers *regs)
+{
+  return re_search_stub (bufp, string, length, start, range, length, regs, 0);
+}
+#ifdef _LIBC
+weak_alias (__re_search, re_search)
+#endif
+
+int
+re_match_2 (struct re_pattern_buffer *bufp,
+	    const char *string1, int length1,
+	    const char *string2, int length2, int start,
+	    struct re_registers *regs, int stop)
+{
+  return re_search_2_stub (bufp, string1, length1, string2, length2,
+			   start, 0, regs, stop, 1);
+}
+#ifdef _LIBC
+weak_alias (__re_match_2, re_match_2)
+#endif
+
+int
+re_search_2 (struct re_pattern_buffer *bufp,
+	     const char *string1, int length1,
+	     const char *string2, int length2, int start,
+	     int range, struct re_registers *regs,  int stop)
+{
+  return re_search_2_stub (bufp, string1, length1, string2, length2,
+			   start, range, regs, stop, 0);
+}
+#ifdef _LIBC
+weak_alias (__re_search_2, re_search_2)
+#endif
+
+static int
+re_search_2_stub (struct re_pattern_buffer *bufp,
+		  const char *string1, int length1,
+		  const char *string2, int length2, int start,
+		  int range, struct re_registers *regs,
+		  int stop, int ret_len)
+{
+  const char *str;
+  int rval;
+  int len = length1 + length2;
+  int free_str = 0;
+
+  if (BE (length1 < 0 || length2 < 0 || stop < 0, 0))
+    return -2;
+
+  /* Concatenate the strings.  */
+  if (length2 > 0)
+    if (length1 > 0)
+      {
+	char *s = re_malloc (char, len);
+
+	if (BE (s == NULL, 0))
+	  return -2;
+	memcpy (s, string1, length1);
+	memcpy (s + length1, string2, length2);
+	str = s;
+	free_str = 1;
+      }
+    else
+      str = string2;
+  else
+    str = string1;
+
+  rval = re_search_stub (bufp, str, len, start, range, stop, regs, ret_len);
+  if (free_str)
+    re_free ((char *) str);
+  return rval;
+}
+
+/* The parameters have the same meaning as those of re_search.
+   Additional parameters:
+   If RET_LEN is nonzero the length of the match is returned (re_match style);
+   otherwise the position of the match is returned.  */
+
+static int
+re_search_stub (struct re_pattern_buffer *bufp,
+		const char *string, int length, int start,
+		int range, int stop,
+		struct re_registers *regs, int ret_len)
+{
+  reg_errcode_t result;
+  regmatch_t *pmatch;
+  int nregs, rval;
+  int eflags = 0;
+
+  /* Check for out-of-range.  */
+  if (BE (start < 0 || start > length, 0))
+    return -1;
+  if (BE (start + range > length, 0))
+    range = length - start;
+  else if (BE (start + range < 0, 0))
+    range = -start;
+
+  __libc_lock_lock (dfa->lock);
+
+  eflags |= (bufp->not_bol) ? REG_NOTBOL : 0;
+  eflags |= (bufp->not_eol) ? REG_NOTEOL : 0;
+
+  /* Compile fastmap if we haven't yet.  */
+  if (range > 0 && bufp->fastmap != NULL && !bufp->fastmap_accurate)
+    re_compile_fastmap (bufp);
+
+  if (BE (bufp->no_sub, 0))
+    regs = NULL;
+
+  /* We need at least 1 register.  */
+  if (regs == NULL)
+    nregs = 1;
+  else if (BE (bufp->regs_allocated == REGS_FIXED &&
+	       regs->num_regs < bufp->re_nsub + 1, 0))
+    {
+      nregs = regs->num_regs;
+      if (BE (nregs < 1, 0))
+	{
+	  /* Nothing can be copied to regs.  */
+	  regs = NULL;
+	  nregs = 1;
+	}
+    }
+  else
+    nregs = bufp->re_nsub + 1;
+  pmatch = re_malloc (regmatch_t, nregs);
+  if (BE (pmatch == NULL, 0))
+    {
+      rval = -2;
+      goto out;
+    }
+
+  result = re_search_internal (bufp, string, length, start, range, stop,
+			       nregs, pmatch, eflags);
+
+  rval = 0;
+
+  /* I hope we needn't fill ther regs with -1's when no match was found.  */
+  if (result != REG_NOERROR)
+    rval = -1;
+  else if (regs != NULL)
+    {
+      /* If caller wants register contents data back, copy them.  */
+      bufp->regs_allocated = re_copy_regs (regs, pmatch, nregs,
+					   bufp->regs_allocated);
+      if (BE (bufp->regs_allocated == REGS_UNALLOCATED, 0))
+	rval = -2;
+    }
+
+  if (BE (rval == 0, 1))
+    {
+      if (ret_len)
+	{
+	  assert (pmatch[0].rm_so == start);
+	  rval = pmatch[0].rm_eo - start;
+	}
+      else
+	rval = pmatch[0].rm_so;
+    }
+  re_free (pmatch);
+ out:
+  __libc_lock_unlock (dfa->lock);
+  return rval;
+}
+
+static unsigned
+re_copy_regs (struct re_registers *regs,
+	      regmatch_t *pmatch,
+	      unsigned int nregs, int regs_allocated)
+{
+  int rval = REGS_REALLOCATE;
+  unsigned int i;
+  unsigned int need_regs = nregs + 1;
+  /* We need one extra element beyond `num_regs' for the `-1' marker GNU code
+     uses.  */
+
+  /* Have the register data arrays been allocated?  */
+  if (regs_allocated == REGS_UNALLOCATED)
+    { /* No.  So allocate them with malloc.  */
+      regs->start = re_malloc (regoff_t, need_regs);
+      if (BE (regs->start == NULL, 0))
+	return REGS_UNALLOCATED;
+      regs->end = re_malloc (regoff_t, need_regs);
+      if (BE (regs->end == NULL, 0))
+	{
+	  re_free (regs->start);
+	  return REGS_UNALLOCATED;
+	}
+      regs->num_regs = need_regs;
+    }
+  else if (regs_allocated == REGS_REALLOCATE)
+    { /* Yes.  If we need more elements than were already
+	 allocated, reallocate them.  If we need fewer, just
+	 leave it alone.  */
+      if (BE (need_regs > regs->num_regs, 0))
+	{
+	  regoff_t *new_start = re_realloc (regs->start, regoff_t, need_regs);
+	  regoff_t *new_end;
+	  if (BE (new_start == NULL, 0))
+	    return REGS_UNALLOCATED;
+	  new_end = re_realloc (regs->end, regoff_t, need_regs);
+	  if (BE (new_end == NULL, 0))
+	    {
+	      re_free (new_start);
+	      return REGS_UNALLOCATED;
+	    }
+	  regs->start = new_start;
+	  regs->end = new_end;
+	  regs->num_regs = need_regs;
+	}
+    }
+  else
+    {
+      assert (regs_allocated == REGS_FIXED);
+      /* This function may not be called with REGS_FIXED and nregs too big.  */
+      assert (regs->num_regs >= nregs);
+      rval = REGS_FIXED;
+    }
+
+  /* Copy the regs.  */
+  for (i = 0; i < nregs; ++i)
+    {
+      regs->start[i] = pmatch[i].rm_so;
+      regs->end[i] = pmatch[i].rm_eo;
+    }
+  for ( ; i < regs->num_regs; ++i)
+    regs->start[i] = regs->end[i] = -1;
+
+  return rval;
+}
+
+/* Set REGS to hold NUM_REGS registers, storing them in STARTS and
+   ENDS.  Subsequent matches using PATTERN_BUFFER and REGS will use
+   this memory for recording register information.  STARTS and ENDS
+   must be allocated using the malloc library routine, and must each
+   be at least NUM_REGS * sizeof (regoff_t) bytes long.
+
+   If NUM_REGS == 0, then subsequent matches should allocate their own
+   register data.
+
+   Unless this function is called, the first search or match using
+   PATTERN_BUFFER will allocate its own register data, without
+   freeing the old data.  */
+
+void
+re_set_registers (struct re_pattern_buffer *bufp,
+		  struct re_registers *regs,
+		  unsigned num_regs,
+		  regoff_t *starts,
+		  regoff_t *ends)
+{
+  if (num_regs)
+    {
+      bufp->regs_allocated = REGS_REALLOCATE;
+      regs->num_regs = num_regs;
+      regs->start = starts;
+      regs->end = ends;
+    }
+  else
+    {
+      bufp->regs_allocated = REGS_UNALLOCATED;
+      regs->num_regs = 0;
+      regs->start = regs->end = (regoff_t *) 0;
+    }
+}
+#ifdef _LIBC
+weak_alias (__re_set_registers, re_set_registers)
+#endif
+
+/* Entry points compatible with 4.2 BSD regex library.  We don't define
+   them unless specifically requested.  */
+
+#if defined _REGEX_RE_COMP || defined _LIBC
+int
+# ifdef _LIBC
+weak_function
+# endif
+re_exec (s)
+     const char *s;
+{
+  return 0 == regexec (&re_comp_buf, s, 0, NULL, 0);
+}
+#endif /* _REGEX_RE_COMP */
+
+/* Internal entry point.  */
+
+/* Searches for a compiled pattern PREG in the string STRING, whose
+   length is LENGTH.  NMATCH, PMATCH, and EFLAGS have the same
+   mingings with regexec.  START, and RANGE have the same meanings
+   with re_search.
+   Return REG_NOERROR if we find a match, and REG_NOMATCH if not,
+   otherwise return the error code.
+   Note: We assume front end functions already check ranges.
+   (START + RANGE >= 0 && START + RANGE <= LENGTH)  */
+
+static reg_errcode_t
+re_search_internal (const regex_t *preg,
+		    const char *string,
+		    int length, int start, int range, int stop,
+		    size_t nmatch, regmatch_t pmatch[],
+		    int eflags)
+{
+  reg_errcode_t err;
+  const re_dfa_t *dfa = (const re_dfa_t *) preg->buffer;
+  int left_lim, right_lim, incr;
+  int fl_longest_match, match_first, match_kind, match_last = -1;
+  unsigned int extra_nmatch;
+  int sb, ch;
+#if defined _LIBC || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)
+  re_match_context_t mctx = { .dfa = dfa };
+#else
+  re_match_context_t mctx;
+#endif
+  char *fastmap = (preg->fastmap != NULL && preg->fastmap_accurate
+		   && range && !preg->can_be_null) ? preg->fastmap : NULL;
+  RE_TRANSLATE_TYPE t = preg->translate;
+
+#if !(defined _LIBC || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
+  memset (&mctx, '\0', sizeof (re_match_context_t));
+  mctx.dfa = dfa;
+#endif
+
+  extra_nmatch = (nmatch > preg->re_nsub) ? nmatch - (preg->re_nsub + 1) : 0;
+  nmatch -= extra_nmatch;
+
+  /* Check if the DFA haven't been compiled.  */
+  if (BE (preg->used == 0 || dfa->init_state == NULL
+	  || dfa->init_state_word == NULL || dfa->init_state_nl == NULL
+	  || dfa->init_state_begbuf == NULL, 0))
+    return REG_NOMATCH;
+
+#ifdef DEBUG
+  /* We assume front-end functions already check them.  */
+  assert (start + range >= 0 && start + range <= length);
+#endif
+
+  /* If initial states with non-begbuf contexts have no elements,
+     the regex must be anchored.  If preg->newline_anchor is set,
+     we'll never use init_state_nl, so do not check it.  */
+  if (dfa->init_state->nodes.nelem == 0
+      && dfa->init_state_word->nodes.nelem == 0
+      && (dfa->init_state_nl->nodes.nelem == 0
+	  || !preg->newline_anchor))
+    {
+      if (start != 0 && start + range != 0)
+	return REG_NOMATCH;
+      start = range = 0;
+    }
+
+  /* We must check the longest matching, if nmatch > 0.  */
+  fl_longest_match = (nmatch != 0 || dfa->nbackref);
+
+  err = re_string_allocate (&mctx.input, string, length, dfa->nodes_len + 1,
+			    preg->translate, preg->syntax & RE_ICASE, dfa);
+  if (BE (err != REG_NOERROR, 0))
+    goto free_return;
+  mctx.input.stop = stop;
+  mctx.input.raw_stop = stop;
+  mctx.input.newline_anchor = preg->newline_anchor;
+
+  err = match_ctx_init (&mctx, eflags, dfa->nbackref * 2);
+  if (BE (err != REG_NOERROR, 0))
+    goto free_return;
+
+  /* We will log all the DFA states through which the dfa pass,
+     if nmatch > 1, or this dfa has "multibyte node", which is a
+     back-reference or a node which can accept multibyte character or
+     multi character collating element.  */
+  if (nmatch > 1 || dfa->has_mb_node)
+    {
+      /* Avoid overflow.  */
+      if (BE (SIZE_MAX / sizeof (re_dfastate_t *) <= (size_t)mctx.input.bufs_len, 0))
+	{
+	  err = REG_ESPACE;
+	  goto free_return;
+	}
+
+      mctx.state_log = re_malloc (re_dfastate_t *, mctx.input.bufs_len + 1);
+      if (BE (mctx.state_log == NULL, 0))
+	{
+	  err = REG_ESPACE;
+	  goto free_return;
+	}
+    }
+  else
+    mctx.state_log = NULL;
+
+  match_first = start;
+  mctx.input.tip_context = (eflags & REG_NOTBOL) ? CONTEXT_BEGBUF
+			   : CONTEXT_NEWLINE | CONTEXT_BEGBUF;
+
+  /* Check incrementally whether of not the input string match.  */
+  incr = (range < 0) ? -1 : 1;
+  left_lim = (range < 0) ? start + range : start;
+  right_lim = (range < 0) ? start : start + range;
+  sb = dfa->mb_cur_max == 1;
+  match_kind =
+    (fastmap
+     ? ((sb || !(preg->syntax & RE_ICASE || t) ? 4 : 0)
+	| (range >= 0 ? 2 : 0)
+	| (t != NULL ? 1 : 0))
+     : 8);
+
+  for (;; match_first += incr)
+    {
+      err = REG_NOMATCH;
+      if (match_first < left_lim || right_lim < match_first)
+	goto free_return;
+
+      /* Advance as rapidly as possible through the string, until we
+	 find a plausible place to start matching.  This may be done
+	 with varying efficiency, so there are various possibilities:
+	 only the most common of them are specialized, in order to
+	 save on code size.  We use a switch statement for speed.  */
+      switch (match_kind)
+	{
+	case 8:
+	  /* No fastmap.  */
+	  break;
+
+	case 7:
+	  /* Fastmap with single-byte translation, match forward.  */
+	  while (BE (match_first < right_lim, 1)
+		 && !fastmap[t[(unsigned char) string[match_first]]])
+	    ++match_first;
+	  goto forward_match_found_start_or_reached_end;
+
+	case 6:
+	  /* Fastmap without translation, match forward.  */
+	  while (BE (match_first < right_lim, 1)
+		 && !fastmap[(unsigned char) string[match_first]])
+	    ++match_first;
+
+	forward_match_found_start_or_reached_end:
+	  if (BE (match_first == right_lim, 0))
+	    {
+	      ch = match_first >= length
+		       ? 0 : (unsigned char) string[match_first];
+	      if (!fastmap[t ? t[ch] : ch])
+		goto free_return;
+	    }
+	  break;
+
+	case 4:
+	case 5:
+	  /* Fastmap without multi-byte translation, match backwards.  */
+	  while (match_first >= left_lim)
+	    {
+	      ch = match_first >= length
+		       ? 0 : (unsigned char) string[match_first];
+	      if (fastmap[t ? t[ch] : ch])
+		break;
+	      --match_first;
+	    }
+	  if (match_first < left_lim)
+	    goto free_return;
+	  break;
+
+	default:
+	  /* In this case, we can't determine easily the current byte,
+	     since it might be a component byte of a multibyte
+	     character.  Then we use the constructed buffer instead.  */
+	  for (;;)
+	    {
+	      /* If MATCH_FIRST is out of the valid range, reconstruct the
+		 buffers.  */
+	      unsigned int offset = match_first - mctx.input.raw_mbs_idx;
+	      if (BE (offset >= (unsigned int) mctx.input.valid_raw_len, 0))
+		{
+		  err = re_string_reconstruct (&mctx.input, match_first,
+					       eflags);
+		  if (BE (err != REG_NOERROR, 0))
+		    goto free_return;
+
+		  offset = match_first - mctx.input.raw_mbs_idx;
+		}
+	      /* If MATCH_FIRST is out of the buffer, leave it as '\0'.
+		 Note that MATCH_FIRST must not be smaller than 0.  */
+	      ch = (match_first >= length
+		    ? 0 : re_string_byte_at (&mctx.input, offset));
+	      if (fastmap[ch])
+		break;
+	      match_first += incr;
+	      if (match_first < left_lim || match_first > right_lim)
+		{
+		  err = REG_NOMATCH;
+		  goto free_return;
+		}
+	    }
+	  break;
+	}
+
+      /* Reconstruct the buffers so that the matcher can assume that
+	 the matching starts from the beginning of the buffer.  */
+      err = re_string_reconstruct (&mctx.input, match_first, eflags);
+      if (BE (err != REG_NOERROR, 0))
+	goto free_return;
+
+#ifdef RE_ENABLE_I18N
+     /* Don't consider this char as a possible match start if it part,
+	yet isn't the head, of a multibyte character.  */
+      if (!sb && !re_string_first_byte (&mctx.input, 0))
+	continue;
+#endif
+
+      /* It seems to be appropriate one, then use the matcher.  */
+      /* We assume that the matching starts from 0.  */
+      mctx.state_log_top = mctx.nbkref_ents = mctx.max_mb_elem_len = 0;
+      match_last = check_matching (&mctx, fl_longest_match,
+				   range >= 0 ? &match_first : NULL);
+      if (match_last != -1)
+	{
+	  if (BE (match_last == -2, 0))
+	    {
+	      err = REG_ESPACE;
+	      goto free_return;
+	    }
+	  else
+	    {
+	      mctx.match_last = match_last;
+	      if ((!preg->no_sub && nmatch > 1) || dfa->nbackref)
+		{
+		  re_dfastate_t *pstate = mctx.state_log[match_last];
+		  mctx.last_node = check_halt_state_context (&mctx, pstate,
+							     match_last);
+		}
+	      if ((!preg->no_sub && nmatch > 1 && dfa->has_plural_match)
+		  || dfa->nbackref)
+		{
+		  err = prune_impossible_nodes (&mctx);
+		  if (err == REG_NOERROR)
+		    break;
+		  if (BE (err != REG_NOMATCH, 0))
+		    goto free_return;
+		  match_last = -1;
+		}
+	      else
+		break; /* We found a match.  */
+	    }
+	}
+
+      match_ctx_clean (&mctx);
+    }
+
+#ifdef DEBUG
+  assert (match_last != -1);
+  assert (err == REG_NOERROR);
+#endif
+
+  /* Set pmatch[] if we need.  */
+  if (nmatch > 0)
+    {
+      unsigned int reg_idx;
+
+      /* Initialize registers.  */
+      for (reg_idx = 1; reg_idx < nmatch; ++reg_idx)
+	pmatch[reg_idx].rm_so = pmatch[reg_idx].rm_eo = -1;
+
+      /* Set the points where matching start/end.  */
+      pmatch[0].rm_so = 0;
+      pmatch[0].rm_eo = mctx.match_last;
+
+      if (!preg->no_sub && nmatch > 1)
+	{
+	  err = set_regs (preg, &mctx, nmatch, pmatch,
+			  dfa->has_plural_match && dfa->nbackref > 0);
+	  if (BE (err != REG_NOERROR, 0))
+	    goto free_return;
+	}
+
+      /* At last, add the offset to the each registers, since we slided
+	 the buffers so that we could assume that the matching starts
+	 from 0.  */
+      for (reg_idx = 0; reg_idx < nmatch; ++reg_idx)
+	if (pmatch[reg_idx].rm_so != -1)
+	  {
+#ifdef RE_ENABLE_I18N
+	    if (BE (mctx.input.offsets_needed != 0, 0))
+	      {
+		pmatch[reg_idx].rm_so =
+		  (pmatch[reg_idx].rm_so == mctx.input.valid_len
+		   ? mctx.input.valid_raw_len
+		   : mctx.input.offsets[pmatch[reg_idx].rm_so]);
+		pmatch[reg_idx].rm_eo =
+		  (pmatch[reg_idx].rm_eo == mctx.input.valid_len
+		   ? mctx.input.valid_raw_len
+		   : mctx.input.offsets[pmatch[reg_idx].rm_eo]);
+	      }
+#else
+	    assert (mctx.input.offsets_needed == 0);
+#endif
+	    pmatch[reg_idx].rm_so += match_first;
+	    pmatch[reg_idx].rm_eo += match_first;
+	  }
+      for (reg_idx = 0; reg_idx < extra_nmatch; ++reg_idx)
+	{
+	  pmatch[nmatch + reg_idx].rm_so = -1;
+	  pmatch[nmatch + reg_idx].rm_eo = -1;
+	}
+
+      if (dfa->subexp_map)
+	for (reg_idx = 0; reg_idx + 1 < nmatch; reg_idx++)
+	  if (dfa->subexp_map[reg_idx] != (int)reg_idx)
+	    {
+	      pmatch[reg_idx + 1].rm_so
+		= pmatch[dfa->subexp_map[reg_idx] + 1].rm_so;
+	      pmatch[reg_idx + 1].rm_eo
+		= pmatch[dfa->subexp_map[reg_idx] + 1].rm_eo;
+	    }
+    }
+
+ free_return:
+  re_free (mctx.state_log);
+  if (dfa->nbackref)
+    match_ctx_free (&mctx);
+  re_string_destruct (&mctx.input);
+  return err;
+}
+
+static reg_errcode_t
+prune_impossible_nodes (re_match_context_t *mctx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  int halt_node, match_last;
+  reg_errcode_t ret;
+  re_dfastate_t **sifted_states;
+  re_dfastate_t **lim_states = NULL;
+  re_sift_context_t sctx;
+#ifdef DEBUG
+  assert (mctx->state_log != NULL);
+#endif
+  match_last = mctx->match_last;
+  halt_node = mctx->last_node;
+
+  /* Avoid overflow.  */
+  if (BE (SIZE_MAX / sizeof (re_dfastate_t *) <= (size_t)match_last, 0))
+    return REG_ESPACE;
+
+  sifted_states = re_malloc (re_dfastate_t *, match_last + 1);
+  if (BE (sifted_states == NULL, 0))
+    {
+      ret = REG_ESPACE;
+      goto free_return;
+    }
+  if (dfa->nbackref)
+    {
+      lim_states = re_malloc (re_dfastate_t *, match_last + 1);
+      if (BE (lim_states == NULL, 0))
+	{
+	  ret = REG_ESPACE;
+	  goto free_return;
+	}
+      while (1)
+	{
+	  memset (lim_states, '\0',
+		  sizeof (re_dfastate_t *) * (match_last + 1));
+	  sift_ctx_init (&sctx, sifted_states, lim_states, halt_node,
+			 match_last);
+	  ret = sift_states_backward (mctx, &sctx);
+	  re_node_set_free (&sctx.limits);
+	  if (BE (ret != REG_NOERROR, 0))
+	      goto free_return;
+	  if (sifted_states[0] != NULL || lim_states[0] != NULL)
+	    break;
+	  do
+	    {
+	      --match_last;
+	      if (match_last < 0)
+		{
+		  ret = REG_NOMATCH;
+		  goto free_return;
+		}
+	    } while (mctx->state_log[match_last] == NULL
+		     || !mctx->state_log[match_last]->halt);
+	  halt_node = check_halt_state_context (mctx,
+						mctx->state_log[match_last],
+						match_last);
+	}
+      ret = merge_state_array (dfa, sifted_states, lim_states,
+			       match_last + 1);
+      re_free (lim_states);
+      lim_states = NULL;
+      if (BE (ret != REG_NOERROR, 0))
+	goto free_return;
+    }
+  else
+    {
+      sift_ctx_init (&sctx, sifted_states, lim_states, halt_node, match_last);
+      ret = sift_states_backward (mctx, &sctx);
+      re_node_set_free (&sctx.limits);
+      if (BE (ret != REG_NOERROR, 0))
+	goto free_return;
+      if (sifted_states[0] == NULL)
+	{
+	  ret = REG_NOMATCH;
+	  goto free_return;
+	}
+    }
+  re_free (mctx->state_log);
+  mctx->state_log = sifted_states;
+  sifted_states = NULL;
+  mctx->last_node = halt_node;
+  mctx->match_last = match_last;
+  ret = REG_NOERROR;
+ free_return:
+  re_free (sifted_states);
+  re_free (lim_states);
+  return ret;
+}
+
+/* Acquire an initial state and return it.
+   We must select appropriate initial state depending on the context,
+   since initial states may have constraints like "\<", "^", etc..  */
+
+static inline re_dfastate_t *
+__attribute ((always_inline)) internal_function
+acquire_init_state_context (reg_errcode_t *err, const re_match_context_t *mctx,
+			    int idx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  if (dfa->init_state->has_constraint)
+    {
+      unsigned int context;
+      context = re_string_context_at (&mctx->input, idx - 1, mctx->eflags);
+      if (IS_WORD_CONTEXT (context))
+	return dfa->init_state_word;
+      else if (IS_ORDINARY_CONTEXT (context))
+	return dfa->init_state;
+      else if (IS_BEGBUF_CONTEXT (context) && IS_NEWLINE_CONTEXT (context))
+	return dfa->init_state_begbuf;
+      else if (IS_NEWLINE_CONTEXT (context))
+	return dfa->init_state_nl;
+      else if (IS_BEGBUF_CONTEXT (context))
+	{
+	  /* It is relatively rare case, then calculate on demand.  */
+	  return re_acquire_state_context (err, dfa,
+					   dfa->init_state->entrance_nodes,
+					   context);
+	}
+      else
+	/* Must not happen?  */
+	return dfa->init_state;
+    }
+  else
+    return dfa->init_state;
+}
+
+/* Check whether the regular expression match input string INPUT or not,
+   and return the index where the matching end, return -1 if not match,
+   or return -2 in case of an error.
+   FL_LONGEST_MATCH means we want the POSIX longest matching.
+   If P_MATCH_FIRST is not NULL, and the match fails, it is set to the
+   next place where we may want to try matching.
+   Note that the matcher assume that the maching starts from the current
+   index of the buffer.  */
+
+static int
+internal_function
+check_matching (re_match_context_t *mctx, int fl_longest_match,
+		int *p_match_first)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err;
+  int match = 0;
+  int match_last = -1;
+  int cur_str_idx = re_string_cur_idx (&mctx->input);
+  re_dfastate_t *cur_state;
+  int at_init_state = p_match_first != NULL;
+  int next_start_idx = cur_str_idx;
+
+  err = REG_NOERROR;
+  cur_state = acquire_init_state_context (&err, mctx, cur_str_idx);
+  /* An initial state must not be NULL (invalid).  */
+  if (BE (cur_state == NULL, 0))
+    {
+      assert (err == REG_ESPACE);
+      return -2;
+    }
+
+  if (mctx->state_log != NULL)
+    {
+      mctx->state_log[cur_str_idx] = cur_state;
+
+      /* Check OP_OPEN_SUBEXP in the initial state in case that we use them
+	 later.  E.g. Processing back references.  */
+      if (BE (dfa->nbackref, 0))
+	{
+	  at_init_state = 0;
+	  err = check_subexp_matching_top (mctx, &cur_state->nodes, 0);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+
+	  if (cur_state->has_backref)
+	    {
+	      err = transit_state_bkref (mctx, &cur_state->nodes);
+	      if (BE (err != REG_NOERROR, 0))
+		return err;
+	    }
+	}
+    }
+
+  /* If the RE accepts NULL string.  */
+  if (BE (cur_state->halt, 0))
+    {
+      if (!cur_state->has_constraint
+	  || check_halt_state_context (mctx, cur_state, cur_str_idx))
+	{
+	  if (!fl_longest_match)
+	    return cur_str_idx;
+	  else
+	    {
+	      match_last = cur_str_idx;
+	      match = 1;
+	    }
+	}
+    }
+
+  while (!re_string_eoi (&mctx->input))
+    {
+      re_dfastate_t *old_state = cur_state;
+      int next_char_idx = re_string_cur_idx (&mctx->input) + 1;
+
+      if (BE (next_char_idx >= mctx->input.bufs_len, 0)
+	  || (BE (next_char_idx >= mctx->input.valid_len, 0)
+	      && mctx->input.valid_len < mctx->input.len))
+	{
+	  err = extend_buffers (mctx);
+	  if (BE (err != REG_NOERROR, 0))
+	    {
+	      assert (err == REG_ESPACE);
+	      return -2;
+	    }
+	}
+
+      cur_state = transit_state (&err, mctx, cur_state);
+      if (mctx->state_log != NULL)
+	cur_state = merge_state_with_log (&err, mctx, cur_state);
+
+      if (cur_state == NULL)
+	{
+	  /* Reached the invalid state or an error.  Try to recover a valid
+	     state using the state log, if available and if we have not
+	     already found a valid (even if not the longest) match.  */
+	  if (BE (err != REG_NOERROR, 0))
+	    return -2;
+
+	  if (mctx->state_log == NULL
+	      || (match && !fl_longest_match)
+	      || (cur_state = find_recover_state (&err, mctx)) == NULL)
+	    break;
+	}
+
+      if (BE (at_init_state, 0))
+	{
+	  if (old_state == cur_state)
+	    next_start_idx = next_char_idx;
+	  else
+	    at_init_state = 0;
+	}
+
+      if (cur_state->halt)
+	{
+	  /* Reached a halt state.
+	     Check the halt state can satisfy the current context.  */
+	  if (!cur_state->has_constraint
+	      || check_halt_state_context (mctx, cur_state,
+					   re_string_cur_idx (&mctx->input)))
+	    {
+	      /* We found an appropriate halt state.  */
+	      match_last = re_string_cur_idx (&mctx->input);
+	      match = 1;
+
+	      /* We found a match, do not modify match_first below.  */
+	      p_match_first = NULL;
+	      if (!fl_longest_match)
+		break;
+	    }
+	}
+    }
+
+  if (p_match_first)
+    *p_match_first += next_start_idx;
+
+  return match_last;
+}
+
+/* Check NODE match the current context.  */
+
+static int
+internal_function
+check_halt_node_context (const re_dfa_t *dfa, int node, unsigned int context)
+{
+  re_token_type_t type = dfa->nodes[node].type;
+  unsigned int constraint = dfa->nodes[node].constraint;
+  if (type != END_OF_RE)
+    return 0;
+  if (!constraint)
+    return 1;
+  if (NOT_SATISFY_NEXT_CONSTRAINT (constraint, context))
+    return 0;
+  return 1;
+}
+
+/* Check the halt state STATE match the current context.
+   Return 0 if not match, if the node, STATE has, is a halt node and
+   match the context, return the node.  */
+
+static int
+internal_function
+check_halt_state_context (const re_match_context_t *mctx,
+			  const re_dfastate_t *state, int idx)
+{
+  int i;
+  unsigned int context;
+#ifdef DEBUG
+  assert (state->halt);
+#endif
+  context = re_string_context_at (&mctx->input, idx, mctx->eflags);
+  for (i = 0; i < state->nodes.nelem; ++i)
+    if (check_halt_node_context (mctx->dfa, state->nodes.elems[i], context))
+      return state->nodes.elems[i];
+  return 0;
+}
+
+/* Compute the next node to which "NFA" transit from NODE("NFA" is a NFA
+   corresponding to the DFA).
+   Return the destination node, and update EPS_VIA_NODES, return -1 in case
+   of errors.  */
+
+static int
+internal_function
+proceed_next_node (const re_match_context_t *mctx, int nregs, regmatch_t *regs,
+		   int *pidx, int node, re_node_set *eps_via_nodes,
+		   struct re_fail_stack_t *fs)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  int i, err;
+  if (IS_EPSILON_NODE (dfa->nodes[node].type))
+    {
+      re_node_set *cur_nodes = &mctx->state_log[*pidx]->nodes;
+      re_node_set *edests = &dfa->edests[node];
+      int dest_node;
+      err = re_node_set_insert (eps_via_nodes, node);
+      if (BE (err < 0, 0))
+	return -2;
+      /* Pick up a valid destination, or return -1 if none is found.  */
+      for (dest_node = -1, i = 0; i < edests->nelem; ++i)
+	{
+	  int candidate = edests->elems[i];
+	  if (!re_node_set_contains (cur_nodes, candidate))
+	    continue;
+	  if (dest_node == -1)
+	    dest_node = candidate;
+
+	  else
+	    {
+	      /* In order to avoid infinite loop like "(a*)*", return the second
+		 epsilon-transition if the first was already considered.  */
+	      if (re_node_set_contains (eps_via_nodes, dest_node))
+		return candidate;
+
+	      /* Otherwise, push the second epsilon-transition on the fail stack.  */
+	      else if (fs != NULL
+		       && push_fail_stack (fs, *pidx, candidate, nregs, regs,
+					   eps_via_nodes))
+		return -2;
+
+	      /* We know we are going to exit.  */
+	      break;
+	    }
+	}
+      return dest_node;
+    }
+  else
+    {
+      int naccepted = 0;
+      re_token_type_t type = dfa->nodes[node].type;
+
+#ifdef RE_ENABLE_I18N
+      if (dfa->nodes[node].accept_mb)
+	naccepted = check_node_accept_bytes (dfa, node, &mctx->input, *pidx);
+      else
+#endif /* RE_ENABLE_I18N */
+      if (type == OP_BACK_REF)
+	{
+	  int subexp_idx = dfa->nodes[node].opr.idx + 1;
+	  naccepted = regs[subexp_idx].rm_eo - regs[subexp_idx].rm_so;
+	  if (fs != NULL)
+	    {
+	      if (regs[subexp_idx].rm_so == -1 || regs[subexp_idx].rm_eo == -1)
+		return -1;
+	      else if (naccepted)
+		{
+		  char *buf = (char *) re_string_get_buffer (&mctx->input);
+		  if (memcmp (buf + regs[subexp_idx].rm_so, buf + *pidx,
+			      naccepted) != 0)
+		    return -1;
+		}
+	    }
+
+	  if (naccepted == 0)
+	    {
+	      int dest_node;
+	      err = re_node_set_insert (eps_via_nodes, node);
+	      if (BE (err < 0, 0))
+		return -2;
+	      dest_node = dfa->edests[node].elems[0];
+	      if (re_node_set_contains (&mctx->state_log[*pidx]->nodes,
+					dest_node))
+		return dest_node;
+	    }
+	}
+
+      if (naccepted != 0
+	  || check_node_accept (mctx, dfa->nodes + node, *pidx))
+	{
+	  int dest_node = dfa->nexts[node];
+	  *pidx = (naccepted == 0) ? *pidx + 1 : *pidx + naccepted;
+	  if (fs && (*pidx > mctx->match_last || mctx->state_log[*pidx] == NULL
+		     || !re_node_set_contains (&mctx->state_log[*pidx]->nodes,
+					       dest_node)))
+	    return -1;
+	  re_node_set_empty (eps_via_nodes);
+	  return dest_node;
+	}
+    }
+  return -1;
+}
+
+static reg_errcode_t
+internal_function
+push_fail_stack (struct re_fail_stack_t *fs, int str_idx, int dest_node,
+		 int nregs, regmatch_t *regs, re_node_set *eps_via_nodes)
+{
+  reg_errcode_t err;
+  int num = fs->num++;
+  if (fs->num == fs->alloc)
+    {
+      struct re_fail_stack_ent_t *new_array;
+      new_array = realloc (fs->stack, (sizeof (struct re_fail_stack_ent_t)
+				       * fs->alloc * 2));
+      if (new_array == NULL)
+	return REG_ESPACE;
+      fs->alloc *= 2;
+      fs->stack = new_array;
+    }
+  fs->stack[num].idx = str_idx;
+  fs->stack[num].node = dest_node;
+  fs->stack[num].regs = re_malloc (regmatch_t, nregs);
+  if (fs->stack[num].regs == NULL)
+    return REG_ESPACE;
+  memcpy (fs->stack[num].regs, regs, sizeof (regmatch_t) * nregs);
+  err = re_node_set_init_copy (&fs->stack[num].eps_via_nodes, eps_via_nodes);
+  return err;
+}
+
+static int
+internal_function
+pop_fail_stack (struct re_fail_stack_t *fs, int *pidx, int nregs,
+		regmatch_t *regs, re_node_set *eps_via_nodes)
+{
+  int num = --fs->num;
+  assert (num >= 0);
+  *pidx = fs->stack[num].idx;
+  memcpy (regs, fs->stack[num].regs, sizeof (regmatch_t) * nregs);
+  re_node_set_free (eps_via_nodes);
+  re_free (fs->stack[num].regs);
+  *eps_via_nodes = fs->stack[num].eps_via_nodes;
+  return fs->stack[num].node;
+}
+
+/* Set the positions where the subexpressions are starts/ends to registers
+   PMATCH.
+   Note: We assume that pmatch[0] is already set, and
+   pmatch[i].rm_so == pmatch[i].rm_eo == -1 for 0 < i < nmatch.  */
+
+static reg_errcode_t
+internal_function
+set_regs (const regex_t *preg, const re_match_context_t *mctx, size_t nmatch,
+	  regmatch_t *pmatch, int fl_backtrack)
+{
+  const re_dfa_t *dfa = (const re_dfa_t *) preg->buffer;
+  int idx, cur_node;
+  re_node_set eps_via_nodes;
+  struct re_fail_stack_t *fs;
+  struct re_fail_stack_t fs_body = { 0, 2, NULL };
+  regmatch_t *prev_idx_match;
+  int prev_idx_match_malloced = 0;
+
+#ifdef DEBUG
+  assert (nmatch > 1);
+  assert (mctx->state_log != NULL);
+#endif
+  if (fl_backtrack)
+    {
+      fs = &fs_body;
+      fs->stack = re_malloc (struct re_fail_stack_ent_t, fs->alloc);
+      if (fs->stack == NULL)
+	return REG_ESPACE;
+    }
+  else
+    fs = NULL;
+
+  cur_node = dfa->init_node;
+  re_node_set_init_empty (&eps_via_nodes);
+
+#ifdef HAVE_ALLOCA
+  if (__libc_use_alloca (nmatch * sizeof (regmatch_t)))
+    prev_idx_match = (regmatch_t *) alloca (nmatch * sizeof (regmatch_t));
+  else
+#endif
+    {
+      prev_idx_match = re_malloc (regmatch_t, nmatch);
+      if (prev_idx_match == NULL)
+	{
+	  free_fail_stack_return (fs);
+	  return REG_ESPACE;
+	}
+      prev_idx_match_malloced = 1;
+    }
+  memcpy (prev_idx_match, pmatch, sizeof (regmatch_t) * nmatch);
+
+  for (idx = pmatch[0].rm_so; idx <= pmatch[0].rm_eo ;)
+    {
+      update_regs (dfa, pmatch, prev_idx_match, cur_node, idx, nmatch);
+
+      if (idx == pmatch[0].rm_eo && cur_node == mctx->last_node)
+	{
+	  unsigned int reg_idx;
+	  if (fs)
+	    {
+	      for (reg_idx = 0; reg_idx < nmatch; ++reg_idx)
+		if (pmatch[reg_idx].rm_so > -1 && pmatch[reg_idx].rm_eo == -1)
+		  break;
+	      if (reg_idx == nmatch)
+		{
+		  re_node_set_free (&eps_via_nodes);
+		  if (prev_idx_match_malloced)
+		    re_free (prev_idx_match);
+		  return free_fail_stack_return (fs);
+		}
+	      cur_node = pop_fail_stack (fs, &idx, nmatch, pmatch,
+					 &eps_via_nodes);
+	    }
+	  else
+	    {
+	      re_node_set_free (&eps_via_nodes);
+	      if (prev_idx_match_malloced)
+		re_free (prev_idx_match);
+	      return REG_NOERROR;
+	    }
+	}
+
+      /* Proceed to next node.  */
+      cur_node = proceed_next_node (mctx, nmatch, pmatch, &idx, cur_node,
+				    &eps_via_nodes, fs);
+
+      if (BE (cur_node < 0, 0))
+	{
+	  if (BE (cur_node == -2, 0))
+	    {
+	      re_node_set_free (&eps_via_nodes);
+	      if (prev_idx_match_malloced)
+		re_free (prev_idx_match);
+	      free_fail_stack_return (fs);
+	      return REG_ESPACE;
+	    }
+	  if (fs)
+	    cur_node = pop_fail_stack (fs, &idx, nmatch, pmatch,
+				       &eps_via_nodes);
+	  else
+	    {
+	      re_node_set_free (&eps_via_nodes);
+	      if (prev_idx_match_malloced)
+		re_free (prev_idx_match);
+	      return REG_NOMATCH;
+	    }
+	}
+    }
+  re_node_set_free (&eps_via_nodes);
+  if (prev_idx_match_malloced)
+    re_free (prev_idx_match);
+  return free_fail_stack_return (fs);
+}
+
+static reg_errcode_t
+internal_function
+free_fail_stack_return (struct re_fail_stack_t *fs)
+{
+  if (fs)
+    {
+      int fs_idx;
+      for (fs_idx = 0; fs_idx < fs->num; ++fs_idx)
+	{
+	  re_node_set_free (&fs->stack[fs_idx].eps_via_nodes);
+	  re_free (fs->stack[fs_idx].regs);
+	}
+      re_free (fs->stack);
+    }
+  return REG_NOERROR;
+}
+
+static void
+internal_function
+update_regs (const re_dfa_t *dfa, regmatch_t *pmatch,
+	     regmatch_t *prev_idx_match, int cur_node, int cur_idx, int nmatch)
+{
+  int type = dfa->nodes[cur_node].type;
+  if (type == OP_OPEN_SUBEXP)
+    {
+      int reg_num = dfa->nodes[cur_node].opr.idx + 1;
+
+      /* We are at the first node of this sub expression.  */
+      if (reg_num < nmatch)
+	{
+	  pmatch[reg_num].rm_so = cur_idx;
+	  pmatch[reg_num].rm_eo = -1;
+	}
+    }
+  else if (type == OP_CLOSE_SUBEXP)
+    {
+      int reg_num = dfa->nodes[cur_node].opr.idx + 1;
+      if (reg_num < nmatch)
+	{
+	  /* We are at the last node of this sub expression.  */
+	  if (pmatch[reg_num].rm_so < cur_idx)
+	    {
+	      pmatch[reg_num].rm_eo = cur_idx;
+	      /* This is a non-empty match or we are not inside an optional
+		 subexpression.  Accept this right away.  */
+	      memcpy (prev_idx_match, pmatch, sizeof (regmatch_t) * nmatch);
+	    }
+	  else
+	    {
+	      if (dfa->nodes[cur_node].opt_subexp
+		  && prev_idx_match[reg_num].rm_so != -1)
+		/* We transited through an empty match for an optional
+		   subexpression, like (a?)*, and this is not the subexp's
+		   first match.  Copy back the old content of the registers
+		   so that matches of an inner subexpression are undone as
+		   well, like in ((a?))*.  */
+		memcpy (pmatch, prev_idx_match, sizeof (regmatch_t) * nmatch);
+	      else
+		/* We completed a subexpression, but it may be part of
+		   an optional one, so do not update PREV_IDX_MATCH.  */
+		pmatch[reg_num].rm_eo = cur_idx;
+	    }
+	}
+    }
+}
+
+/* This function checks the STATE_LOG from the SCTX->last_str_idx to 0
+   and sift the nodes in each states according to the following rules.
+   Updated state_log will be wrote to STATE_LOG.
+
+   Rules: We throw away the Node `a' in the STATE_LOG[STR_IDX] if...
+     1. When STR_IDX == MATCH_LAST(the last index in the state_log):
+	If `a' isn't the LAST_NODE and `a' can't epsilon transit to
+	the LAST_NODE, we throw away the node `a'.
+     2. When 0 <= STR_IDX < MATCH_LAST and `a' accepts
+	string `s' and transit to `b':
+	i. If 'b' isn't in the STATE_LOG[STR_IDX+strlen('s')], we throw
+	   away the node `a'.
+	ii. If 'b' is in the STATE_LOG[STR_IDX+strlen('s')] but 'b' is
+	    thrown away, we throw away the node `a'.
+     3. When 0 <= STR_IDX < MATCH_LAST and 'a' epsilon transit to 'b':
+	i. If 'b' isn't in the STATE_LOG[STR_IDX], we throw away the
+	   node `a'.
+	ii. If 'b' is in the STATE_LOG[STR_IDX] but 'b' is thrown away,
+	    we throw away the node `a'.  */
+
+#define STATE_NODE_CONTAINS(state,node) \
+  ((state) != NULL && re_node_set_contains (&(state)->nodes, node))
+
+static reg_errcode_t
+internal_function
+sift_states_backward (const re_match_context_t *mctx, re_sift_context_t *sctx)
+{
+  reg_errcode_t err;
+  int null_cnt = 0;
+  int str_idx = sctx->last_str_idx;
+  re_node_set cur_dest;
+
+#ifdef DEBUG
+  assert (mctx->state_log != NULL && mctx->state_log[str_idx] != NULL);
+#endif
+
+  /* Build sifted state_log[str_idx].  It has the nodes which can epsilon
+     transit to the last_node and the last_node itself.  */
+  err = re_node_set_init_1 (&cur_dest, sctx->last_node);
+  if (BE (err != REG_NOERROR, 0))
+    return err;
+  err = update_cur_sifted_state (mctx, sctx, str_idx, &cur_dest);
+  if (BE (err != REG_NOERROR, 0))
+    goto free_return;
+
+  /* Then check each states in the state_log.  */
+  while (str_idx > 0)
+    {
+      /* Update counters.  */
+      null_cnt = (sctx->sifted_states[str_idx] == NULL) ? null_cnt + 1 : 0;
+      if (null_cnt > mctx->max_mb_elem_len)
+	{
+	  memset (sctx->sifted_states, '\0',
+		  sizeof (re_dfastate_t *) * str_idx);
+	  re_node_set_free (&cur_dest);
+	  return REG_NOERROR;
+	}
+      re_node_set_empty (&cur_dest);
+      --str_idx;
+
+      if (mctx->state_log[str_idx])
+	{
+	  err = build_sifted_states (mctx, sctx, str_idx, &cur_dest);
+	  if (BE (err != REG_NOERROR, 0))
+	    goto free_return;
+	}
+
+      /* Add all the nodes which satisfy the following conditions:
+	 - It can epsilon transit to a node in CUR_DEST.
+	 - It is in CUR_SRC.
+	 And update state_log.  */
+      err = update_cur_sifted_state (mctx, sctx, str_idx, &cur_dest);
+      if (BE (err != REG_NOERROR, 0))
+	goto free_return;
+    }
+  err = REG_NOERROR;
+ free_return:
+  re_node_set_free (&cur_dest);
+  return err;
+}
+
+static reg_errcode_t
+internal_function
+build_sifted_states (const re_match_context_t *mctx, re_sift_context_t *sctx,
+		     int str_idx, re_node_set *cur_dest)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  const re_node_set *cur_src = &mctx->state_log[str_idx]->non_eps_nodes;
+  int i;
+
+  /* Then build the next sifted state.
+     We build the next sifted state on `cur_dest', and update
+     `sifted_states[str_idx]' with `cur_dest'.
+     Note:
+     `cur_dest' is the sifted state from `state_log[str_idx + 1]'.
+     `cur_src' points the node_set of the old `state_log[str_idx]'
+     (with the epsilon nodes pre-filtered out).  */
+  for (i = 0; i < cur_src->nelem; i++)
+    {
+      int prev_node = cur_src->elems[i];
+      int naccepted = 0;
+      int ret;
+
+#ifdef DEBUG
+      re_token_type_t type = dfa->nodes[prev_node].type;
+      assert (!IS_EPSILON_NODE (type));
+#endif
+#ifdef RE_ENABLE_I18N
+      /* If the node may accept `multi byte'.  */
+      if (dfa->nodes[prev_node].accept_mb)
+	naccepted = sift_states_iter_mb (mctx, sctx, prev_node,
+					 str_idx, sctx->last_str_idx);
+#endif /* RE_ENABLE_I18N */
+
+      /* We don't check backreferences here.
+	 See update_cur_sifted_state().  */
+      if (!naccepted
+	  && check_node_accept (mctx, dfa->nodes + prev_node, str_idx)
+	  && STATE_NODE_CONTAINS (sctx->sifted_states[str_idx + 1],
+				  dfa->nexts[prev_node]))
+	naccepted = 1;
+
+      if (naccepted == 0)
+	continue;
+
+      if (sctx->limits.nelem)
+	{
+	  int to_idx = str_idx + naccepted;
+	  if (check_dst_limits (mctx, &sctx->limits,
+				dfa->nexts[prev_node], to_idx,
+				prev_node, str_idx))
+	    continue;
+	}
+      ret = re_node_set_insert (cur_dest, prev_node);
+      if (BE (ret == -1, 0))
+	return REG_ESPACE;
+    }
+
+  return REG_NOERROR;
+}
+
+/* Helper functions.  */
+
+static reg_errcode_t
+internal_function
+clean_state_log_if_needed (re_match_context_t *mctx, int next_state_log_idx)
+{
+  int top = mctx->state_log_top;
+
+  if (next_state_log_idx >= mctx->input.bufs_len
+      || (next_state_log_idx >= mctx->input.valid_len
+	  && mctx->input.valid_len < mctx->input.len))
+    {
+      reg_errcode_t err;
+      err = extend_buffers (mctx);
+      if (BE (err != REG_NOERROR, 0))
+	return err;
+    }
+
+  if (top < next_state_log_idx)
+    {
+      memset (mctx->state_log + top + 1, '\0',
+	      sizeof (re_dfastate_t *) * (next_state_log_idx - top));
+      mctx->state_log_top = next_state_log_idx;
+    }
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function
+merge_state_array (const re_dfa_t *dfa, re_dfastate_t **dst,
+		   re_dfastate_t **src, int num)
+{
+  int st_idx;
+  reg_errcode_t err;
+  for (st_idx = 0; st_idx < num; ++st_idx)
+    {
+      if (dst[st_idx] == NULL)
+	dst[st_idx] = src[st_idx];
+      else if (src[st_idx] != NULL)
+	{
+	  re_node_set merged_set;
+	  err = re_node_set_init_union (&merged_set, &dst[st_idx]->nodes,
+					&src[st_idx]->nodes);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+	  dst[st_idx] = re_acquire_state (&err, dfa, &merged_set);
+	  re_node_set_free (&merged_set);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+	}
+    }
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function
+update_cur_sifted_state (const re_match_context_t *mctx,
+			 re_sift_context_t *sctx, int str_idx,
+			 re_node_set *dest_nodes)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err = REG_NOERROR;
+  const re_node_set *candidates;
+  candidates = ((mctx->state_log[str_idx] == NULL) ? NULL
+		: &mctx->state_log[str_idx]->nodes);
+
+  if (dest_nodes->nelem == 0)
+    sctx->sifted_states[str_idx] = NULL;
+  else
+    {
+      if (candidates)
+	{
+	  /* At first, add the nodes which can epsilon transit to a node in
+	     DEST_NODE.  */
+	  err = add_epsilon_src_nodes (dfa, dest_nodes, candidates);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+
+	  /* Then, check the limitations in the current sift_context.  */
+	  if (sctx->limits.nelem)
+	    {
+	      err = check_subexp_limits (dfa, dest_nodes, candidates, &sctx->limits,
+					 mctx->bkref_ents, str_idx);
+	      if (BE (err != REG_NOERROR, 0))
+		return err;
+	    }
+	}
+
+      sctx->sifted_states[str_idx] = re_acquire_state (&err, dfa, dest_nodes);
+      if (BE (err != REG_NOERROR, 0))
+	return err;
+    }
+
+  if (candidates && mctx->state_log[str_idx]->has_backref)
+    {
+      err = sift_states_bkref (mctx, sctx, str_idx, candidates);
+      if (BE (err != REG_NOERROR, 0))
+	return err;
+    }
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function
+add_epsilon_src_nodes (const re_dfa_t *dfa, re_node_set *dest_nodes,
+		       const re_node_set *candidates)
+{
+  reg_errcode_t err = REG_NOERROR;
+  int i;
+
+  re_dfastate_t *state = re_acquire_state (&err, dfa, dest_nodes);
+  if (BE (err != REG_NOERROR, 0))
+    return err;
+
+  if (!state->inveclosure.alloc)
+    {
+      err = re_node_set_alloc (&state->inveclosure, dest_nodes->nelem);
+      if (BE (err != REG_NOERROR, 0))
+	return REG_ESPACE;
+      for (i = 0; i < dest_nodes->nelem; i++)
+	{
+	  err = re_node_set_merge (&state->inveclosure,
+				   dfa->inveclosures + dest_nodes->elems[i]);
+	  if (BE (err != REG_NOERROR, 0))
+	    return REG_ESPACE;
+	}
+    }
+  return re_node_set_add_intersect (dest_nodes, candidates,
+				    &state->inveclosure);
+}
+
+static reg_errcode_t
+internal_function
+sub_epsilon_src_nodes (const re_dfa_t *dfa, int node, re_node_set *dest_nodes,
+		       const re_node_set *candidates)
+{
+    int ecl_idx;
+    reg_errcode_t err;
+    re_node_set *inv_eclosure = dfa->inveclosures + node;
+    re_node_set except_nodes;
+    re_node_set_init_empty (&except_nodes);
+    for (ecl_idx = 0; ecl_idx < inv_eclosure->nelem; ++ecl_idx)
+      {
+	int cur_node = inv_eclosure->elems[ecl_idx];
+	if (cur_node == node)
+	  continue;
+	if (IS_EPSILON_NODE (dfa->nodes[cur_node].type))
+	  {
+	    int edst1 = dfa->edests[cur_node].elems[0];
+	    int edst2 = ((dfa->edests[cur_node].nelem > 1)
+			 ? dfa->edests[cur_node].elems[1] : -1);
+	    if ((!re_node_set_contains (inv_eclosure, edst1)
+		 && re_node_set_contains (dest_nodes, edst1))
+		|| (edst2 > 0
+		    && !re_node_set_contains (inv_eclosure, edst2)
+		    && re_node_set_contains (dest_nodes, edst2)))
+	      {
+		err = re_node_set_add_intersect (&except_nodes, candidates,
+						 dfa->inveclosures + cur_node);
+		if (BE (err != REG_NOERROR, 0))
+		  {
+		    re_node_set_free (&except_nodes);
+		    return err;
+		  }
+	      }
+	  }
+      }
+    for (ecl_idx = 0; ecl_idx < inv_eclosure->nelem; ++ecl_idx)
+      {
+	int cur_node = inv_eclosure->elems[ecl_idx];
+	if (!re_node_set_contains (&except_nodes, cur_node))
+	  {
+	    int idx = re_node_set_contains (dest_nodes, cur_node) - 1;
+	    re_node_set_remove_at (dest_nodes, idx);
+	  }
+      }
+    re_node_set_free (&except_nodes);
+    return REG_NOERROR;
+}
+
+static int
+internal_function
+check_dst_limits (const re_match_context_t *mctx, re_node_set *limits,
+		  int dst_node, int dst_idx, int src_node, int src_idx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  int lim_idx, src_pos, dst_pos;
+
+  int dst_bkref_idx = search_cur_bkref_entry (mctx, dst_idx);
+  int src_bkref_idx = search_cur_bkref_entry (mctx, src_idx);
+  for (lim_idx = 0; lim_idx < limits->nelem; ++lim_idx)
+    {
+      int subexp_idx;
+      struct re_backref_cache_entry *ent;
+      ent = mctx->bkref_ents + limits->elems[lim_idx];
+      subexp_idx = dfa->nodes[ent->node].opr.idx;
+
+      dst_pos = check_dst_limits_calc_pos (mctx, limits->elems[lim_idx],
+					   subexp_idx, dst_node, dst_idx,
+					   dst_bkref_idx);
+      src_pos = check_dst_limits_calc_pos (mctx, limits->elems[lim_idx],
+					   subexp_idx, src_node, src_idx,
+					   src_bkref_idx);
+
+      /* In case of:
+	 <src> <dst> ( <subexp> )
+	 ( <subexp> ) <src> <dst>
+	 ( <subexp1> <src> <subexp2> <dst> <subexp3> )  */
+      if (src_pos == dst_pos)
+	continue; /* This is unrelated limitation.  */
+      else
+	return 1;
+    }
+  return 0;
+}
+
+static int
+internal_function
+check_dst_limits_calc_pos_1 (const re_match_context_t *mctx, int boundaries,
+			     int subexp_idx, int from_node, int bkref_idx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  const re_node_set *eclosures = dfa->eclosures + from_node;
+  int node_idx;
+
+  /* Else, we are on the boundary: examine the nodes on the epsilon
+     closure.  */
+  for (node_idx = 0; node_idx < eclosures->nelem; ++node_idx)
+    {
+      int node = eclosures->elems[node_idx];
+      switch (dfa->nodes[node].type)
+	{
+	case OP_BACK_REF:
+	  if (bkref_idx != -1)
+	    {
+	      struct re_backref_cache_entry *ent = mctx->bkref_ents + bkref_idx;
+	      do
+		{
+		  int dst, cpos;
+
+		  if (ent->node != node)
+		    continue;
+
+		  if (subexp_idx < BITSET_WORD_BITS
+		      && !(ent->eps_reachable_subexps_map
+			   & ((bitset_word_t) 1 << subexp_idx)))
+		    continue;
+
+		  /* Recurse trying to reach the OP_OPEN_SUBEXP and
+		     OP_CLOSE_SUBEXP cases below.  But, if the
+		     destination node is the same node as the source
+		     node, don't recurse because it would cause an
+		     infinite loop: a regex that exhibits this behavior
+		     is ()\1*\1*  */
+		  dst = dfa->edests[node].elems[0];
+		  if (dst == from_node)
+		    {
+		      if (boundaries & 1)
+			return -1;
+		      else /* if (boundaries & 2) */
+			return 0;
+		    }
+
+		  cpos =
+		    check_dst_limits_calc_pos_1 (mctx, boundaries, subexp_idx,
+						 dst, bkref_idx);
+		  if (cpos == -1 /* && (boundaries & 1) */)
+		    return -1;
+		  if (cpos == 0 && (boundaries & 2))
+		    return 0;
+
+		  if (subexp_idx < BITSET_WORD_BITS)
+		    ent->eps_reachable_subexps_map
+		      &= ~((bitset_word_t) 1 << subexp_idx);
+		}
+	      while (ent++->more);
+	    }
+	  break;
+
+	case OP_OPEN_SUBEXP:
+	  if ((boundaries & 1) && subexp_idx == dfa->nodes[node].opr.idx)
+	    return -1;
+	  break;
+
+	case OP_CLOSE_SUBEXP:
+	  if ((boundaries & 2) && subexp_idx == dfa->nodes[node].opr.idx)
+	    return 0;
+	  break;
+
+	default:
+	    break;
+	}
+    }
+
+  return (boundaries & 2) ? 1 : 0;
+}
+
+static int
+internal_function
+check_dst_limits_calc_pos (const re_match_context_t *mctx, int limit,
+			   int subexp_idx, int from_node, int str_idx,
+			   int bkref_idx)
+{
+  struct re_backref_cache_entry *lim = mctx->bkref_ents + limit;
+  int boundaries;
+
+  /* If we are outside the range of the subexpression, return -1 or 1.  */
+  if (str_idx < lim->subexp_from)
+    return -1;
+
+  if (lim->subexp_to < str_idx)
+    return 1;
+
+  /* If we are within the subexpression, return 0.  */
+  boundaries = (str_idx == lim->subexp_from);
+  boundaries |= (str_idx == lim->subexp_to) << 1;
+  if (boundaries == 0)
+    return 0;
+
+  /* Else, examine epsilon closure.  */
+  return check_dst_limits_calc_pos_1 (mctx, boundaries, subexp_idx,
+				      from_node, bkref_idx);
+}
+
+/* Check the limitations of sub expressions LIMITS, and remove the nodes
+   which are against limitations from DEST_NODES. */
+
+static reg_errcode_t
+internal_function
+check_subexp_limits (const re_dfa_t *dfa, re_node_set *dest_nodes,
+		     const re_node_set *candidates, re_node_set *limits,
+		     struct re_backref_cache_entry *bkref_ents, int str_idx)
+{
+  reg_errcode_t err;
+  int node_idx, lim_idx;
+
+  for (lim_idx = 0; lim_idx < limits->nelem; ++lim_idx)
+    {
+      int subexp_idx;
+      struct re_backref_cache_entry *ent;
+      ent = bkref_ents + limits->elems[lim_idx];
+
+      if (str_idx <= ent->subexp_from || ent->str_idx < str_idx)
+	continue; /* This is unrelated limitation.  */
+
+      subexp_idx = dfa->nodes[ent->node].opr.idx;
+      if (ent->subexp_to == str_idx)
+	{
+	  int ops_node = -1;
+	  int cls_node = -1;
+	  for (node_idx = 0; node_idx < dest_nodes->nelem; ++node_idx)
+	    {
+	      int node = dest_nodes->elems[node_idx];
+	      re_token_type_t type = dfa->nodes[node].type;
+	      if (type == OP_OPEN_SUBEXP
+		  && subexp_idx == dfa->nodes[node].opr.idx)
+		ops_node = node;
+	      else if (type == OP_CLOSE_SUBEXP
+		       && subexp_idx == dfa->nodes[node].opr.idx)
+		cls_node = node;
+	    }
+
+	  /* Check the limitation of the open subexpression.  */
+	  /* Note that (ent->subexp_to = str_idx != ent->subexp_from).  */
+	  if (ops_node >= 0)
+	    {
+	      err = sub_epsilon_src_nodes (dfa, ops_node, dest_nodes,
+					   candidates);
+	      if (BE (err != REG_NOERROR, 0))
+		return err;
+	    }
+
+	  /* Check the limitation of the close subexpression.  */
+	  if (cls_node >= 0)
+	    for (node_idx = 0; node_idx < dest_nodes->nelem; ++node_idx)
+	      {
+		int node = dest_nodes->elems[node_idx];
+		if (!re_node_set_contains (dfa->inveclosures + node,
+					   cls_node)
+		    && !re_node_set_contains (dfa->eclosures + node,
+					      cls_node))
+		  {
+		    /* It is against this limitation.
+		       Remove it form the current sifted state.  */
+		    err = sub_epsilon_src_nodes (dfa, node, dest_nodes,
+						 candidates);
+		    if (BE (err != REG_NOERROR, 0))
+		      return err;
+		    --node_idx;
+		  }
+	      }
+	}
+      else /* (ent->subexp_to != str_idx)  */
+	{
+	  for (node_idx = 0; node_idx < dest_nodes->nelem; ++node_idx)
+	    {
+	      int node = dest_nodes->elems[node_idx];
+	      re_token_type_t type = dfa->nodes[node].type;
+	      if (type == OP_CLOSE_SUBEXP || type == OP_OPEN_SUBEXP)
+		{
+		  if (subexp_idx != dfa->nodes[node].opr.idx)
+		    continue;
+		  /* It is against this limitation.
+		     Remove it form the current sifted state.  */
+		  err = sub_epsilon_src_nodes (dfa, node, dest_nodes,
+					       candidates);
+		  if (BE (err != REG_NOERROR, 0))
+		    return err;
+		}
+	    }
+	}
+    }
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function
+sift_states_bkref (const re_match_context_t *mctx, re_sift_context_t *sctx,
+		   int str_idx, const re_node_set *candidates)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err;
+  int node_idx, node;
+  re_sift_context_t local_sctx;
+  int first_idx = search_cur_bkref_entry (mctx, str_idx);
+
+  if (first_idx == -1)
+    return REG_NOERROR;
+
+  local_sctx.sifted_states = NULL; /* Mark that it hasn't been initialized.  */
+
+  for (node_idx = 0; node_idx < candidates->nelem; ++node_idx)
+    {
+      int enabled_idx;
+      re_token_type_t type;
+      struct re_backref_cache_entry *entry;
+      node = candidates->elems[node_idx];
+      type = dfa->nodes[node].type;
+      /* Avoid infinite loop for the REs like "()\1+".  */
+      if (node == sctx->last_node && str_idx == sctx->last_str_idx)
+	continue;
+      if (type != OP_BACK_REF)
+	continue;
+
+      entry = mctx->bkref_ents + first_idx;
+      enabled_idx = first_idx;
+      do
+	{
+	  int subexp_len;
+	  int to_idx;
+	  int dst_node;
+	  int ret;
+	  re_dfastate_t *cur_state;
+
+	  if (entry->node != node)
+	    continue;
+	  subexp_len = entry->subexp_to - entry->subexp_from;
+	  to_idx = str_idx + subexp_len;
+	  dst_node = (subexp_len ? dfa->nexts[node]
+		      : dfa->edests[node].elems[0]);
+
+	  if (to_idx > sctx->last_str_idx
+	      || sctx->sifted_states[to_idx] == NULL
+	      || !STATE_NODE_CONTAINS (sctx->sifted_states[to_idx], dst_node)
+	      || check_dst_limits (mctx, &sctx->limits, node,
+				   str_idx, dst_node, to_idx))
+	    continue;
+
+	  if (local_sctx.sifted_states == NULL)
+	    {
+	      local_sctx = *sctx;
+	      err = re_node_set_init_copy (&local_sctx.limits, &sctx->limits);
+	      if (BE (err != REG_NOERROR, 0))
+		goto free_return;
+	    }
+	  local_sctx.last_node = node;
+	  local_sctx.last_str_idx = str_idx;
+	  ret = re_node_set_insert (&local_sctx.limits, enabled_idx);
+	  if (BE (ret < 0, 0))
+	    {
+	      err = REG_ESPACE;
+	      goto free_return;
+	    }
+	  cur_state = local_sctx.sifted_states[str_idx];
+	  err = sift_states_backward (mctx, &local_sctx);
+	  if (BE (err != REG_NOERROR, 0))
+	    goto free_return;
+	  if (sctx->limited_states != NULL)
+	    {
+	      err = merge_state_array (dfa, sctx->limited_states,
+				       local_sctx.sifted_states,
+				       str_idx + 1);
+	      if (BE (err != REG_NOERROR, 0))
+		goto free_return;
+	    }
+	  local_sctx.sifted_states[str_idx] = cur_state;
+	  re_node_set_remove (&local_sctx.limits, enabled_idx);
+
+	  /* mctx->bkref_ents may have changed, reload the pointer.  */
+	  entry = mctx->bkref_ents + enabled_idx;
+	}
+      while (enabled_idx++, entry++->more);
+    }
+  err = REG_NOERROR;
+ free_return:
+  if (local_sctx.sifted_states != NULL)
+    {
+      re_node_set_free (&local_sctx.limits);
+    }
+
+  return err;
+}
+
+
+#ifdef RE_ENABLE_I18N
+static int
+internal_function
+sift_states_iter_mb (const re_match_context_t *mctx, re_sift_context_t *sctx,
+		     int node_idx, int str_idx, int max_str_idx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  int naccepted;
+  /* Check the node can accept `multi byte'.  */
+  naccepted = check_node_accept_bytes (dfa, node_idx, &mctx->input, str_idx);
+  if (naccepted > 0 && str_idx + naccepted <= max_str_idx &&
+      !STATE_NODE_CONTAINS (sctx->sifted_states[str_idx + naccepted],
+			    dfa->nexts[node_idx]))
+    /* The node can't accept the `multi byte', or the
+       destination was already thrown away, then the node
+       could't accept the current input `multi byte'.   */
+    naccepted = 0;
+  /* Otherwise, it is sure that the node could accept
+     `naccepted' bytes input.  */
+  return naccepted;
+}
+#endif /* RE_ENABLE_I18N */
+
+
+/* Functions for state transition.  */
+
+/* Return the next state to which the current state STATE will transit by
+   accepting the current input byte, and update STATE_LOG if necessary.
+   If STATE can accept a multibyte char/collating element/back reference
+   update the destination of STATE_LOG.  */
+
+static re_dfastate_t *
+internal_function
+transit_state (reg_errcode_t *err, re_match_context_t *mctx,
+	       re_dfastate_t *state)
+{
+  re_dfastate_t **trtable;
+  unsigned char ch;
+
+#ifdef RE_ENABLE_I18N
+  /* If the current state can accept multibyte.  */
+  if (BE (state->accept_mb, 0))
+    {
+      *err = transit_state_mb (mctx, state);
+      if (BE (*err != REG_NOERROR, 0))
+	return NULL;
+    }
+#endif /* RE_ENABLE_I18N */
+
+  /* Then decide the next state with the single byte.  */
+#if 0
+  if (0)
+    /* don't use transition table  */
+    return transit_state_sb (err, mctx, state);
+#endif
+
+  /* Use transition table  */
+  ch = re_string_fetch_byte (&mctx->input);
+  for (;;)
+    {
+      trtable = state->trtable;
+      if (BE (trtable != NULL, 1))
+	return trtable[ch];
+
+      trtable = state->word_trtable;
+      if (BE (trtable != NULL, 1))
+	{
+	  unsigned int context;
+	  context
+	    = re_string_context_at (&mctx->input,
+				    re_string_cur_idx (&mctx->input) - 1,
+				    mctx->eflags);
+	  if (IS_WORD_CONTEXT (context))
+	    return trtable[ch + SBC_MAX];
+	  else
+	    return trtable[ch];
+	}
+
+      if (!build_trtable (mctx->dfa, state))
+	{
+	  *err = REG_ESPACE;
+	  return NULL;
+	}
+
+      /* Retry, we now have a transition table.  */
+    }
+}
+
+/* Update the state_log if we need */
+re_dfastate_t *
+internal_function
+merge_state_with_log (reg_errcode_t *err, re_match_context_t *mctx,
+		      re_dfastate_t *next_state)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  int cur_idx = re_string_cur_idx (&mctx->input);
+
+  if (cur_idx > mctx->state_log_top)
+    {
+      mctx->state_log[cur_idx] = next_state;
+      mctx->state_log_top = cur_idx;
+    }
+  else if (mctx->state_log[cur_idx] == 0)
+    {
+      mctx->state_log[cur_idx] = next_state;
+    }
+  else
+    {
+      re_dfastate_t *pstate;
+      unsigned int context;
+      re_node_set next_nodes, *log_nodes, *table_nodes = NULL;
+      /* If (state_log[cur_idx] != 0), it implies that cur_idx is
+	 the destination of a multibyte char/collating element/
+	 back reference.  Then the next state is the union set of
+	 these destinations and the results of the transition table.  */
+      pstate = mctx->state_log[cur_idx];
+      log_nodes = pstate->entrance_nodes;
+      if (next_state != NULL)
+	{
+	  table_nodes = next_state->entrance_nodes;
+	  *err = re_node_set_init_union (&next_nodes, table_nodes,
+					     log_nodes);
+	  if (BE (*err != REG_NOERROR, 0))
+	    return NULL;
+	}
+      else
+	next_nodes = *log_nodes;
+      /* Note: We already add the nodes of the initial state,
+	 then we don't need to add them here.  */
+
+      context = re_string_context_at (&mctx->input,
+				      re_string_cur_idx (&mctx->input) - 1,
+				      mctx->eflags);
+      next_state = mctx->state_log[cur_idx]
+	= re_acquire_state_context (err, dfa, &next_nodes, context);
+      /* We don't need to check errors here, since the return value of
+	 this function is next_state and ERR is already set.  */
+
+      if (table_nodes != NULL)
+	re_node_set_free (&next_nodes);
+    }
+
+  if (BE (dfa->nbackref, 0) && next_state != NULL)
+    {
+      /* Check OP_OPEN_SUBEXP in the current state in case that we use them
+	 later.  We must check them here, since the back references in the
+	 next state might use them.  */
+      *err = check_subexp_matching_top (mctx, &next_state->nodes,
+					cur_idx);
+      if (BE (*err != REG_NOERROR, 0))
+	return NULL;
+
+      /* If the next state has back references.  */
+      if (next_state->has_backref)
+	{
+	  *err = transit_state_bkref (mctx, &next_state->nodes);
+	  if (BE (*err != REG_NOERROR, 0))
+	    return NULL;
+	  next_state = mctx->state_log[cur_idx];
+	}
+    }
+
+  return next_state;
+}
+
+/* Skip bytes in the input that correspond to part of a
+   multi-byte match, then look in the log for a state
+   from which to restart matching.  */
+re_dfastate_t *
+internal_function
+find_recover_state (reg_errcode_t *err, re_match_context_t *mctx)
+{
+  re_dfastate_t *cur_state;
+  do
+    {
+      int max = mctx->state_log_top;
+      int cur_str_idx = re_string_cur_idx (&mctx->input);
+
+      do
+	{
+	  if (++cur_str_idx > max)
+	    return NULL;
+	  re_string_skip_bytes (&mctx->input, 1);
+	}
+      while (mctx->state_log[cur_str_idx] == NULL);
+
+      cur_state = merge_state_with_log (err, mctx, NULL);
+    }
+  while (*err == REG_NOERROR && cur_state == NULL);
+  return cur_state;
+}
+
+/* Helper functions for transit_state.  */
+
+/* From the node set CUR_NODES, pick up the nodes whose types are
+   OP_OPEN_SUBEXP and which have corresponding back references in the regular
+   expression. And register them to use them later for evaluating the
+   correspoding back references.  */
+
+static reg_errcode_t
+internal_function
+check_subexp_matching_top (re_match_context_t *mctx, re_node_set *cur_nodes,
+			   int str_idx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  int node_idx;
+  reg_errcode_t err;
+
+  /* TODO: This isn't efficient.
+	   Because there might be more than one nodes whose types are
+	   OP_OPEN_SUBEXP and whose index is SUBEXP_IDX, we must check all
+	   nodes.
+	   E.g. RE: (a){2}  */
+  for (node_idx = 0; node_idx < cur_nodes->nelem; ++node_idx)
+    {
+      int node = cur_nodes->elems[node_idx];
+      if (dfa->nodes[node].type == OP_OPEN_SUBEXP
+	  && dfa->nodes[node].opr.idx < BITSET_WORD_BITS
+	  && (dfa->used_bkref_map
+	      & ((bitset_word_t) 1 << dfa->nodes[node].opr.idx)))
+	{
+	  err = match_ctx_add_subtop (mctx, node, str_idx);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+	}
+    }
+  return REG_NOERROR;
+}
+
+#if 0
+/* Return the next state to which the current state STATE will transit by
+   accepting the current input byte.  */
+
+static re_dfastate_t *
+transit_state_sb (reg_errcode_t *err, re_match_context_t *mctx,
+		  re_dfastate_t *state)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  re_node_set next_nodes;
+  re_dfastate_t *next_state;
+  int node_cnt, cur_str_idx = re_string_cur_idx (&mctx->input);
+  unsigned int context;
+
+  *err = re_node_set_alloc (&next_nodes, state->nodes.nelem + 1);
+  if (BE (*err != REG_NOERROR, 0))
+    return NULL;
+  for (node_cnt = 0; node_cnt < state->nodes.nelem; ++node_cnt)
+    {
+      int cur_node = state->nodes.elems[node_cnt];
+      if (check_node_accept (mctx, dfa->nodes + cur_node, cur_str_idx))
+	{
+	  *err = re_node_set_merge (&next_nodes,
+				    dfa->eclosures + dfa->nexts[cur_node]);
+	  if (BE (*err != REG_NOERROR, 0))
+	    {
+	      re_node_set_free (&next_nodes);
+	      return NULL;
+	    }
+	}
+    }
+  context = re_string_context_at (&mctx->input, cur_str_idx, mctx->eflags);
+  next_state = re_acquire_state_context (err, dfa, &next_nodes, context);
+  /* We don't need to check errors here, since the return value of
+     this function is next_state and ERR is already set.  */
+
+  re_node_set_free (&next_nodes);
+  re_string_skip_bytes (&mctx->input, 1);
+  return next_state;
+}
+#endif
+
+#ifdef RE_ENABLE_I18N
+static reg_errcode_t
+internal_function
+transit_state_mb (re_match_context_t *mctx, re_dfastate_t *pstate)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err;
+  int i;
+
+  for (i = 0; i < pstate->nodes.nelem; ++i)
+    {
+      re_node_set dest_nodes, *new_nodes;
+      int cur_node_idx = pstate->nodes.elems[i];
+      int naccepted, dest_idx;
+      unsigned int context;
+      re_dfastate_t *dest_state;
+
+      if (!dfa->nodes[cur_node_idx].accept_mb)
+	continue;
+
+      if (dfa->nodes[cur_node_idx].constraint)
+	{
+	  context = re_string_context_at (&mctx->input,
+					  re_string_cur_idx (&mctx->input),
+					  mctx->eflags);
+	  if (NOT_SATISFY_NEXT_CONSTRAINT (dfa->nodes[cur_node_idx].constraint,
+					   context))
+	    continue;
+	}
+
+      /* How many bytes the node can accept?  */
+      naccepted = check_node_accept_bytes (dfa, cur_node_idx, &mctx->input,
+					   re_string_cur_idx (&mctx->input));
+      if (naccepted == 0)
+	continue;
+
+      /* The node can accepts `naccepted' bytes.  */
+      dest_idx = re_string_cur_idx (&mctx->input) + naccepted;
+      mctx->max_mb_elem_len = ((mctx->max_mb_elem_len < naccepted) ? naccepted
+			       : mctx->max_mb_elem_len);
+      err = clean_state_log_if_needed (mctx, dest_idx);
+      if (BE (err != REG_NOERROR, 0))
+	return err;
+#ifdef DEBUG
+      assert (dfa->nexts[cur_node_idx] != -1);
+#endif
+      new_nodes = dfa->eclosures + dfa->nexts[cur_node_idx];
+
+      dest_state = mctx->state_log[dest_idx];
+      if (dest_state == NULL)
+	dest_nodes = *new_nodes;
+      else
+	{
+	  err = re_node_set_init_union (&dest_nodes,
+					dest_state->entrance_nodes, new_nodes);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+	}
+      context = re_string_context_at (&mctx->input, dest_idx - 1,
+				      mctx->eflags);
+      mctx->state_log[dest_idx]
+	= re_acquire_state_context (&err, dfa, &dest_nodes, context);
+      if (dest_state != NULL)
+	re_node_set_free (&dest_nodes);
+      if (BE (mctx->state_log[dest_idx] == NULL && err != REG_NOERROR, 0))
+	return err;
+    }
+  return REG_NOERROR;
+}
+#endif /* RE_ENABLE_I18N */
+
+static reg_errcode_t
+internal_function
+transit_state_bkref (re_match_context_t *mctx, const re_node_set *nodes)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err;
+  int i;
+  int cur_str_idx = re_string_cur_idx (&mctx->input);
+
+  for (i = 0; i < nodes->nelem; ++i)
+    {
+      int dest_str_idx, prev_nelem, bkc_idx;
+      int node_idx = nodes->elems[i];
+      unsigned int context;
+      const re_token_t *node = dfa->nodes + node_idx;
+      re_node_set *new_dest_nodes;
+
+      /* Check whether `node' is a backreference or not.  */
+      if (node->type != OP_BACK_REF)
+	continue;
+
+      if (node->constraint)
+	{
+	  context = re_string_context_at (&mctx->input, cur_str_idx,
+					  mctx->eflags);
+	  if (NOT_SATISFY_NEXT_CONSTRAINT (node->constraint, context))
+	    continue;
+	}
+
+      /* `node' is a backreference.
+	 Check the substring which the substring matched.  */
+      bkc_idx = mctx->nbkref_ents;
+      err = get_subexp (mctx, node_idx, cur_str_idx);
+      if (BE (err != REG_NOERROR, 0))
+	goto free_return;
+
+      /* And add the epsilon closures (which is `new_dest_nodes') of
+	 the backreference to appropriate state_log.  */
+#ifdef DEBUG
+      assert (dfa->nexts[node_idx] != -1);
+#endif
+      for (; bkc_idx < mctx->nbkref_ents; ++bkc_idx)
+	{
+	  int subexp_len;
+	  re_dfastate_t *dest_state;
+	  struct re_backref_cache_entry *bkref_ent;
+	  bkref_ent = mctx->bkref_ents + bkc_idx;
+	  if (bkref_ent->node != node_idx || bkref_ent->str_idx != cur_str_idx)
+	    continue;
+	  subexp_len = bkref_ent->subexp_to - bkref_ent->subexp_from;
+	  new_dest_nodes = (subexp_len == 0
+			    ? dfa->eclosures + dfa->edests[node_idx].elems[0]
+			    : dfa->eclosures + dfa->nexts[node_idx]);
+	  dest_str_idx = (cur_str_idx + bkref_ent->subexp_to
+			  - bkref_ent->subexp_from);
+	  context = re_string_context_at (&mctx->input, dest_str_idx - 1,
+					  mctx->eflags);
+	  dest_state = mctx->state_log[dest_str_idx];
+	  prev_nelem = ((mctx->state_log[cur_str_idx] == NULL) ? 0
+			: mctx->state_log[cur_str_idx]->nodes.nelem);
+	  /* Add `new_dest_node' to state_log.  */
+	  if (dest_state == NULL)
+	    {
+	      mctx->state_log[dest_str_idx]
+		= re_acquire_state_context (&err, dfa, new_dest_nodes,
+					    context);
+	      if (BE (mctx->state_log[dest_str_idx] == NULL
+		      && err != REG_NOERROR, 0))
+		goto free_return;
+	    }
+	  else
+	    {
+	      re_node_set dest_nodes;
+	      err = re_node_set_init_union (&dest_nodes,
+					    dest_state->entrance_nodes,
+					    new_dest_nodes);
+	      if (BE (err != REG_NOERROR, 0))
+		{
+		  re_node_set_free (&dest_nodes);
+		  goto free_return;
+		}
+	      mctx->state_log[dest_str_idx]
+		= re_acquire_state_context (&err, dfa, &dest_nodes, context);
+	      re_node_set_free (&dest_nodes);
+	      if (BE (mctx->state_log[dest_str_idx] == NULL
+		      && err != REG_NOERROR, 0))
+		goto free_return;
+	    }
+	  /* We need to check recursively if the backreference can epsilon
+	     transit.  */
+	  if (subexp_len == 0
+	      && mctx->state_log[cur_str_idx]->nodes.nelem > prev_nelem)
+	    {
+	      err = check_subexp_matching_top (mctx, new_dest_nodes,
+					       cur_str_idx);
+	      if (BE (err != REG_NOERROR, 0))
+		goto free_return;
+	      err = transit_state_bkref (mctx, new_dest_nodes);
+	      if (BE (err != REG_NOERROR, 0))
+		goto free_return;
+	    }
+	}
+    }
+  err = REG_NOERROR;
+ free_return:
+  return err;
+}
+
+/* Enumerate all the candidates which the backreference BKREF_NODE can match
+   at BKREF_STR_IDX, and register them by match_ctx_add_entry().
+   Note that we might collect inappropriate candidates here.
+   However, the cost of checking them strictly here is too high, then we
+   delay these checking for prune_impossible_nodes().  */
+
+static reg_errcode_t
+internal_function
+get_subexp (re_match_context_t *mctx, int bkref_node, int bkref_str_idx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  int subexp_num, sub_top_idx;
+  const char *buf = (const char *) re_string_get_buffer (&mctx->input);
+  /* Return if we have already checked BKREF_NODE at BKREF_STR_IDX.  */
+  int cache_idx = search_cur_bkref_entry (mctx, bkref_str_idx);
+  if (cache_idx != -1)
+    {
+      const struct re_backref_cache_entry *entry
+	= mctx->bkref_ents + cache_idx;
+      do
+	if (entry->node == bkref_node)
+	  return REG_NOERROR; /* We already checked it.  */
+      while (entry++->more);
+    }
+
+  subexp_num = dfa->nodes[bkref_node].opr.idx;
+
+  /* For each sub expression  */
+  for (sub_top_idx = 0; sub_top_idx < mctx->nsub_tops; ++sub_top_idx)
+    {
+      reg_errcode_t err;
+      re_sub_match_top_t *sub_top = mctx->sub_tops[sub_top_idx];
+      re_sub_match_last_t *sub_last;
+      int sub_last_idx, sl_str, bkref_str_off;
+
+      if (dfa->nodes[sub_top->node].opr.idx != subexp_num)
+	continue; /* It isn't related.  */
+
+      sl_str = sub_top->str_idx;
+      bkref_str_off = bkref_str_idx;
+      /* At first, check the last node of sub expressions we already
+	 evaluated.  */
+      for (sub_last_idx = 0; sub_last_idx < sub_top->nlasts; ++sub_last_idx)
+	{
+	  int sl_str_diff;
+	  sub_last = sub_top->lasts[sub_last_idx];
+	  sl_str_diff = sub_last->str_idx - sl_str;
+	  /* The matched string by the sub expression match with the substring
+	     at the back reference?  */
+	  if (sl_str_diff > 0)
+	    {
+	      if (BE (bkref_str_off + sl_str_diff > mctx->input.valid_len, 0))
+		{
+		  /* Not enough chars for a successful match.  */
+		  if (bkref_str_off + sl_str_diff > mctx->input.len)
+		    break;
+
+		  err = clean_state_log_if_needed (mctx,
+						   bkref_str_off
+						   + sl_str_diff);
+		  if (BE (err != REG_NOERROR, 0))
+		    return err;
+		  buf = (const char *) re_string_get_buffer (&mctx->input);
+		}
+	      if (memcmp (buf + bkref_str_off, buf + sl_str, sl_str_diff) != 0)
+		/* We don't need to search this sub expression any more.  */
+		break;
+	    }
+	  bkref_str_off += sl_str_diff;
+	  sl_str += sl_str_diff;
+	  err = get_subexp_sub (mctx, sub_top, sub_last, bkref_node,
+				bkref_str_idx);
+
+	  /* Reload buf, since the preceding call might have reallocated
+	     the buffer.  */
+	  buf = (const char *) re_string_get_buffer (&mctx->input);
+
+	  if (err == REG_NOMATCH)
+	    continue;
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+	}
+
+      if (sub_last_idx < sub_top->nlasts)
+	continue;
+      if (sub_last_idx > 0)
+	++sl_str;
+      /* Then, search for the other last nodes of the sub expression.  */
+      for (; sl_str <= bkref_str_idx; ++sl_str)
+	{
+	  int cls_node, sl_str_off;
+	  const re_node_set *nodes;
+	  sl_str_off = sl_str - sub_top->str_idx;
+	  /* The matched string by the sub expression match with the substring
+	     at the back reference?  */
+	  if (sl_str_off > 0)
+	    {
+	      if (BE (bkref_str_off >= mctx->input.valid_len, 0))
+		{
+		  /* If we are at the end of the input, we cannot match.  */
+		  if (bkref_str_off >= mctx->input.len)
+		    break;
+
+		  err = extend_buffers (mctx);
+		  if (BE (err != REG_NOERROR, 0))
+		    return err;
+
+		  buf = (const char *) re_string_get_buffer (&mctx->input);
+		}
+	      if (buf [bkref_str_off++] != buf[sl_str - 1])
+		break; /* We don't need to search this sub expression
+			  any more.  */
+	    }
+	  if (mctx->state_log[sl_str] == NULL)
+	    continue;
+	  /* Does this state have a ')' of the sub expression?  */
+	  nodes = &mctx->state_log[sl_str]->nodes;
+	  cls_node = find_subexp_node (dfa, nodes, subexp_num,
+				       OP_CLOSE_SUBEXP);
+	  if (cls_node == -1)
+	    continue; /* No.  */
+	  if (sub_top->path == NULL)
+	    {
+	      sub_top->path = calloc (sizeof (state_array_t),
+				      sl_str - sub_top->str_idx + 1);
+	      if (sub_top->path == NULL)
+		return REG_ESPACE;
+	    }
+	  /* Can the OP_OPEN_SUBEXP node arrive the OP_CLOSE_SUBEXP node
+	     in the current context?  */
+	  err = check_arrival (mctx, sub_top->path, sub_top->node,
+			       sub_top->str_idx, cls_node, sl_str,
+			       OP_CLOSE_SUBEXP);
+	  if (err == REG_NOMATCH)
+	      continue;
+	  if (BE (err != REG_NOERROR, 0))
+	      return err;
+	  sub_last = match_ctx_add_sublast (sub_top, cls_node, sl_str);
+	  if (BE (sub_last == NULL, 0))
+	    return REG_ESPACE;
+	  err = get_subexp_sub (mctx, sub_top, sub_last, bkref_node,
+				bkref_str_idx);
+	  if (err == REG_NOMATCH)
+	    continue;
+	}
+    }
+  return REG_NOERROR;
+}
+
+/* Helper functions for get_subexp().  */
+
+/* Check SUB_LAST can arrive to the back reference BKREF_NODE at BKREF_STR.
+   If it can arrive, register the sub expression expressed with SUB_TOP
+   and SUB_LAST.  */
+
+static reg_errcode_t
+internal_function
+get_subexp_sub (re_match_context_t *mctx, const re_sub_match_top_t *sub_top,
+		re_sub_match_last_t *sub_last, int bkref_node, int bkref_str)
+{
+  reg_errcode_t err;
+  int to_idx;
+  /* Can the subexpression arrive the back reference?  */
+  err = check_arrival (mctx, &sub_last->path, sub_last->node,
+		       sub_last->str_idx, bkref_node, bkref_str,
+		       OP_OPEN_SUBEXP);
+  if (err != REG_NOERROR)
+    return err;
+  err = match_ctx_add_entry (mctx, bkref_node, bkref_str, sub_top->str_idx,
+			     sub_last->str_idx);
+  if (BE (err != REG_NOERROR, 0))
+    return err;
+  to_idx = bkref_str + sub_last->str_idx - sub_top->str_idx;
+  return clean_state_log_if_needed (mctx, to_idx);
+}
+
+/* Find the first node which is '(' or ')' and whose index is SUBEXP_IDX.
+   Search '(' if FL_OPEN, or search ')' otherwise.
+   TODO: This function isn't efficient...
+	 Because there might be more than one nodes whose types are
+	 OP_OPEN_SUBEXP and whose index is SUBEXP_IDX, we must check all
+	 nodes.
+	 E.g. RE: (a){2}  */
+
+static int
+internal_function
+find_subexp_node (const re_dfa_t *dfa, const re_node_set *nodes,
+		  int subexp_idx, int type)
+{
+  int cls_idx;
+  for (cls_idx = 0; cls_idx < nodes->nelem; ++cls_idx)
+    {
+      int cls_node = nodes->elems[cls_idx];
+      const re_token_t *node = dfa->nodes + cls_node;
+      if (node->type == type
+	  && node->opr.idx == subexp_idx)
+	return cls_node;
+    }
+  return -1;
+}
+
+/* Check whether the node TOP_NODE at TOP_STR can arrive to the node
+   LAST_NODE at LAST_STR.  We record the path onto PATH since it will be
+   heavily reused.
+   Return REG_NOERROR if it can arrive, or REG_NOMATCH otherwise.  */
+
+static reg_errcode_t
+internal_function
+check_arrival (re_match_context_t *mctx, state_array_t *path, int top_node,
+	       int top_str, int last_node, int last_str, int type)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err = REG_NOERROR;
+  int subexp_num, backup_cur_idx, str_idx, null_cnt;
+  re_dfastate_t *cur_state = NULL;
+  re_node_set *cur_nodes, next_nodes;
+  re_dfastate_t **backup_state_log;
+  unsigned int context;
+
+  subexp_num = dfa->nodes[top_node].opr.idx;
+  /* Extend the buffer if we need.  */
+  if (BE (path->alloc < last_str + mctx->max_mb_elem_len + 1, 0))
+    {
+      re_dfastate_t **new_array;
+      int old_alloc = path->alloc;
+      path->alloc += last_str + mctx->max_mb_elem_len + 1;
+      new_array = re_realloc (path->array, re_dfastate_t *, path->alloc);
+      if (BE (new_array == NULL, 0))
+	{
+	  path->alloc = old_alloc;
+	  return REG_ESPACE;
+	}
+      path->array = new_array;
+      memset (new_array + old_alloc, '\0',
+	      sizeof (re_dfastate_t *) * (path->alloc - old_alloc));
+    }
+
+  str_idx = path->next_idx ? path->next_idx : top_str;
+
+  /* Temporary modify MCTX.  */
+  backup_state_log = mctx->state_log;
+  backup_cur_idx = mctx->input.cur_idx;
+  mctx->state_log = path->array;
+  mctx->input.cur_idx = str_idx;
+
+  /* Setup initial node set.  */
+  context = re_string_context_at (&mctx->input, str_idx - 1, mctx->eflags);
+  if (str_idx == top_str)
+    {
+      err = re_node_set_init_1 (&next_nodes, top_node);
+      if (BE (err != REG_NOERROR, 0))
+	return err;
+      err = check_arrival_expand_ecl (dfa, &next_nodes, subexp_num, type);
+      if (BE (err != REG_NOERROR, 0))
+	{
+	  re_node_set_free (&next_nodes);
+	  return err;
+	}
+    }
+  else
+    {
+      cur_state = mctx->state_log[str_idx];
+      if (cur_state && cur_state->has_backref)
+	{
+	  err = re_node_set_init_copy (&next_nodes, &cur_state->nodes);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+	}
+      else
+	re_node_set_init_empty (&next_nodes);
+    }
+  if (str_idx == top_str || (cur_state && cur_state->has_backref))
+    {
+      if (next_nodes.nelem)
+	{
+	  err = expand_bkref_cache (mctx, &next_nodes, str_idx,
+				    subexp_num, type);
+	  if (BE (err != REG_NOERROR, 0))
+	    {
+	      re_node_set_free (&next_nodes);
+	      return err;
+	    }
+	}
+      cur_state = re_acquire_state_context (&err, dfa, &next_nodes, context);
+      if (BE (cur_state == NULL && err != REG_NOERROR, 0))
+	{
+	  re_node_set_free (&next_nodes);
+	  return err;
+	}
+      mctx->state_log[str_idx] = cur_state;
+    }
+
+  for (null_cnt = 0; str_idx < last_str && null_cnt <= mctx->max_mb_elem_len;)
+    {
+      re_node_set_empty (&next_nodes);
+      if (mctx->state_log[str_idx + 1])
+	{
+	  err = re_node_set_merge (&next_nodes,
+				   &mctx->state_log[str_idx + 1]->nodes);
+	  if (BE (err != REG_NOERROR, 0))
+	    {
+	      re_node_set_free (&next_nodes);
+	      return err;
+	    }
+	}
+      if (cur_state)
+	{
+	  err = check_arrival_add_next_nodes (mctx, str_idx,
+					      &cur_state->non_eps_nodes,
+					      &next_nodes);
+	  if (BE (err != REG_NOERROR, 0))
+	    {
+	      re_node_set_free (&next_nodes);
+	      return err;
+	    }
+	}
+      ++str_idx;
+      if (next_nodes.nelem)
+	{
+	  err = check_arrival_expand_ecl (dfa, &next_nodes, subexp_num, type);
+	  if (BE (err != REG_NOERROR, 0))
+	    {
+	      re_node_set_free (&next_nodes);
+	      return err;
+	    }
+	  err = expand_bkref_cache (mctx, &next_nodes, str_idx,
+				    subexp_num, type);
+	  if (BE (err != REG_NOERROR, 0))
+	    {
+	      re_node_set_free (&next_nodes);
+	      return err;
+	    }
+	}
+      context = re_string_context_at (&mctx->input, str_idx - 1, mctx->eflags);
+      cur_state = re_acquire_state_context (&err, dfa, &next_nodes, context);
+      if (BE (cur_state == NULL && err != REG_NOERROR, 0))
+	{
+	  re_node_set_free (&next_nodes);
+	  return err;
+	}
+      mctx->state_log[str_idx] = cur_state;
+      null_cnt = cur_state == NULL ? null_cnt + 1 : 0;
+    }
+  re_node_set_free (&next_nodes);
+  cur_nodes = (mctx->state_log[last_str] == NULL ? NULL
+	       : &mctx->state_log[last_str]->nodes);
+  path->next_idx = str_idx;
+
+  /* Fix MCTX.  */
+  mctx->state_log = backup_state_log;
+  mctx->input.cur_idx = backup_cur_idx;
+
+  /* Then check the current node set has the node LAST_NODE.  */
+  if (cur_nodes != NULL && re_node_set_contains (cur_nodes, last_node))
+    return REG_NOERROR;
+
+  return REG_NOMATCH;
+}
+
+/* Helper functions for check_arrival.  */
+
+/* Calculate the destination nodes of CUR_NODES at STR_IDX, and append them
+   to NEXT_NODES.
+   TODO: This function is similar to the functions transit_state*(),
+	 however this function has many additional works.
+	 Can't we unify them?  */
+
+static reg_errcode_t
+internal_function
+check_arrival_add_next_nodes (re_match_context_t *mctx, int str_idx,
+			      re_node_set *cur_nodes, re_node_set *next_nodes)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  int result;
+  int cur_idx;
+#ifdef RE_ENABLE_I18N
+  reg_errcode_t err = REG_NOERROR;
+#endif
+  re_node_set union_set;
+  re_node_set_init_empty (&union_set);
+  for (cur_idx = 0; cur_idx < cur_nodes->nelem; ++cur_idx)
+    {
+      int naccepted = 0;
+      int cur_node = cur_nodes->elems[cur_idx];
+#ifdef DEBUG
+      re_token_type_t type = dfa->nodes[cur_node].type;
+      assert (!IS_EPSILON_NODE (type));
+#endif
+#ifdef RE_ENABLE_I18N
+      /* If the node may accept `multi byte'.  */
+      if (dfa->nodes[cur_node].accept_mb)
+	{
+	  naccepted = check_node_accept_bytes (dfa, cur_node, &mctx->input,
+					       str_idx);
+	  if (naccepted > 1)
+	    {
+	      re_dfastate_t *dest_state;
+	      int next_node = dfa->nexts[cur_node];
+	      int next_idx = str_idx + naccepted;
+	      dest_state = mctx->state_log[next_idx];
+	      re_node_set_empty (&union_set);
+	      if (dest_state)
+		{
+		  err = re_node_set_merge (&union_set, &dest_state->nodes);
+		  if (BE (err != REG_NOERROR, 0))
+		    {
+		      re_node_set_free (&union_set);
+		      return err;
+		    }
+		}
+	      result = re_node_set_insert (&union_set, next_node);
+	      if (BE (result < 0, 0))
+		{
+		  re_node_set_free (&union_set);
+		  return REG_ESPACE;
+		}
+	      mctx->state_log[next_idx] = re_acquire_state (&err, dfa,
+							    &union_set);
+	      if (BE (mctx->state_log[next_idx] == NULL
+		      && err != REG_NOERROR, 0))
+		{
+		  re_node_set_free (&union_set);
+		  return err;
+		}
+	    }
+	}
+#endif /* RE_ENABLE_I18N */
+      if (naccepted
+	  || check_node_accept (mctx, dfa->nodes + cur_node, str_idx))
+	{
+	  result = re_node_set_insert (next_nodes, dfa->nexts[cur_node]);
+	  if (BE (result < 0, 0))
+	    {
+	      re_node_set_free (&union_set);
+	      return REG_ESPACE;
+	    }
+	}
+    }
+  re_node_set_free (&union_set);
+  return REG_NOERROR;
+}
+
+/* For all the nodes in CUR_NODES, add the epsilon closures of them to
+   CUR_NODES, however exclude the nodes which are:
+    - inside the sub expression whose number is EX_SUBEXP, if FL_OPEN.
+    - out of the sub expression whose number is EX_SUBEXP, if !FL_OPEN.
+*/
+
+static reg_errcode_t
+internal_function
+check_arrival_expand_ecl (const re_dfa_t *dfa, re_node_set *cur_nodes,
+			  int ex_subexp, int type)
+{
+  reg_errcode_t err;
+  int idx, outside_node;
+  re_node_set new_nodes;
+#ifdef DEBUG
+  assert (cur_nodes->nelem);
+#endif
+  err = re_node_set_alloc (&new_nodes, cur_nodes->nelem);
+  if (BE (err != REG_NOERROR, 0))
+    return err;
+  /* Create a new node set NEW_NODES with the nodes which are epsilon
+     closures of the node in CUR_NODES.  */
+
+  for (idx = 0; idx < cur_nodes->nelem; ++idx)
+    {
+      int cur_node = cur_nodes->elems[idx];
+      const re_node_set *eclosure = dfa->eclosures + cur_node;
+      outside_node = find_subexp_node (dfa, eclosure, ex_subexp, type);
+      if (outside_node == -1)
+	{
+	  /* There are no problematic nodes, just merge them.  */
+	  err = re_node_set_merge (&new_nodes, eclosure);
+	  if (BE (err != REG_NOERROR, 0))
+	    {
+	      re_node_set_free (&new_nodes);
+	      return err;
+	    }
+	}
+      else
+	{
+	  /* There are problematic nodes, re-calculate incrementally.  */
+	  err = check_arrival_expand_ecl_sub (dfa, &new_nodes, cur_node,
+					      ex_subexp, type);
+	  if (BE (err != REG_NOERROR, 0))
+	    {
+	      re_node_set_free (&new_nodes);
+	      return err;
+	    }
+	}
+    }
+  re_node_set_free (cur_nodes);
+  *cur_nodes = new_nodes;
+  return REG_NOERROR;
+}
+
+/* Helper function for check_arrival_expand_ecl.
+   Check incrementally the epsilon closure of TARGET, and if it isn't
+   problematic append it to DST_NODES.  */
+
+static reg_errcode_t
+internal_function
+check_arrival_expand_ecl_sub (const re_dfa_t *dfa, re_node_set *dst_nodes,
+			      int target, int ex_subexp, int type)
+{
+  int cur_node;
+  for (cur_node = target; !re_node_set_contains (dst_nodes, cur_node);)
+    {
+      int err;
+
+      if (dfa->nodes[cur_node].type == type
+	  && dfa->nodes[cur_node].opr.idx == ex_subexp)
+	{
+	  if (type == OP_CLOSE_SUBEXP)
+	    {
+	      err = re_node_set_insert (dst_nodes, cur_node);
+	      if (BE (err == -1, 0))
+		return REG_ESPACE;
+	    }
+	  break;
+	}
+      err = re_node_set_insert (dst_nodes, cur_node);
+      if (BE (err == -1, 0))
+	return REG_ESPACE;
+      if (dfa->edests[cur_node].nelem == 0)
+	break;
+      if (dfa->edests[cur_node].nelem == 2)
+	{
+	  err = check_arrival_expand_ecl_sub (dfa, dst_nodes,
+					      dfa->edests[cur_node].elems[1],
+					      ex_subexp, type);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
+	}
+      cur_node = dfa->edests[cur_node].elems[0];
+    }
+  return REG_NOERROR;
+}
+
+
+/* For all the back references in the current state, calculate the
+   destination of the back references by the appropriate entry
+   in MCTX->BKREF_ENTS.  */
+
+static reg_errcode_t
+internal_function
+expand_bkref_cache (re_match_context_t *mctx, re_node_set *cur_nodes,
+		    int cur_str, int subexp_num, int type)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err;
+  int cache_idx_start = search_cur_bkref_entry (mctx, cur_str);
+  struct re_backref_cache_entry *ent;
+
+  if (cache_idx_start == -1)
+    return REG_NOERROR;
+
+ restart:
+  ent = mctx->bkref_ents + cache_idx_start;
+  do
+    {
+      int to_idx, next_node;
+
+      /* Is this entry ENT is appropriate?  */
+      if (!re_node_set_contains (cur_nodes, ent->node))
+	continue; /* No.  */
+
+      to_idx = cur_str + ent->subexp_to - ent->subexp_from;
+      /* Calculate the destination of the back reference, and append it
+	 to MCTX->STATE_LOG.  */
+      if (to_idx == cur_str)
+	{
+	  /* The backreference did epsilon transit, we must re-check all the
+	     node in the current state.  */
+	  re_node_set new_dests;
+	  reg_errcode_t err2, err3;
+	  next_node = dfa->edests[ent->node].elems[0];
+	  if (re_node_set_contains (cur_nodes, next_node))
+	    continue;
+	  err = re_node_set_init_1 (&new_dests, next_node);
+	  err2 = check_arrival_expand_ecl (dfa, &new_dests, subexp_num, type);
+	  err3 = re_node_set_merge (cur_nodes, &new_dests);
+	  re_node_set_free (&new_dests);
+	  if (BE (err != REG_NOERROR || err2 != REG_NOERROR
+		  || err3 != REG_NOERROR, 0))
+	    {
+	      err = (err != REG_NOERROR ? err
+		     : (err2 != REG_NOERROR ? err2 : err3));
+	      return err;
+	    }
+	  /* TODO: It is still inefficient...  */
+	  goto restart;
+	}
+      else
+	{
+	  re_node_set union_set;
+	  next_node = dfa->nexts[ent->node];
+	  if (mctx->state_log[to_idx])
+	    {
+	      int ret;
+	      if (re_node_set_contains (&mctx->state_log[to_idx]->nodes,
+					next_node))
+		continue;
+	      err = re_node_set_init_copy (&union_set,
+					   &mctx->state_log[to_idx]->nodes);
+	      ret = re_node_set_insert (&union_set, next_node);
+	      if (BE (err != REG_NOERROR || ret < 0, 0))
+		{
+		  re_node_set_free (&union_set);
+		  err = err != REG_NOERROR ? err : REG_ESPACE;
+		  return err;
+		}
+	    }
+	  else
+	    {
+	      err = re_node_set_init_1 (&union_set, next_node);
+	      if (BE (err != REG_NOERROR, 0))
+		return err;
+	    }
+	  mctx->state_log[to_idx] = re_acquire_state (&err, dfa, &union_set);
+	  re_node_set_free (&union_set);
+	  if (BE (mctx->state_log[to_idx] == NULL
+		  && err != REG_NOERROR, 0))
+	    return err;
+	}
+    }
+  while (ent++->more);
+  return REG_NOERROR;
+}
+
+/* Build transition table for the state.
+   Return 1 if succeeded, otherwise return NULL.  */
+
+static int
+internal_function
+build_trtable (const re_dfa_t *dfa, re_dfastate_t *state)
+{
+  reg_errcode_t err;
+  int i, j, ch, need_word_trtable = 0;
+  bitset_word_t elem, mask;
+  bool dests_node_malloced = false;
+  bool dest_states_malloced = false;
+  int ndests; /* Number of the destination states from `state'.  */
+  re_dfastate_t **trtable;
+  re_dfastate_t **dest_states = NULL, **dest_states_word, **dest_states_nl;
+  re_node_set follows, *dests_node;
+  bitset_t *dests_ch;
+  bitset_t acceptable;
+
+  struct dests_alloc
+  {
+    re_node_set dests_node[SBC_MAX];
+    bitset_t dests_ch[SBC_MAX];
+  } *dests_alloc;
+
+  /* We build DFA states which corresponds to the destination nodes
+     from `state'.  `dests_node[i]' represents the nodes which i-th
+     destination state contains, and `dests_ch[i]' represents the
+     characters which i-th destination state accepts.  */
+#ifdef HAVE_ALLOCA
+  if (__libc_use_alloca (sizeof (struct dests_alloc)))
+    dests_alloc = (struct dests_alloc *) alloca (sizeof (struct dests_alloc));
+  else
+#endif
+    {
+      dests_alloc = re_malloc (struct dests_alloc, 1);
+      if (BE (dests_alloc == NULL, 0))
+	return 0;
+      dests_node_malloced = true;
+    }
+  dests_node = dests_alloc->dests_node;
+  dests_ch = dests_alloc->dests_ch;
+
+  /* Initialize transiton table.  */
+  state->word_trtable = state->trtable = NULL;
+
+  /* At first, group all nodes belonging to `state' into several
+     destinations.  */
+  ndests = group_nodes_into_DFAstates (dfa, state, dests_node, dests_ch);
+  if (BE (ndests <= 0, 0))
+    {
+      if (dests_node_malloced)
+	free (dests_alloc);
+      /* Return 0 in case of an error, 1 otherwise.  */
+      if (ndests == 0)
+	{
+	  state->trtable = (re_dfastate_t **)
+	    calloc (sizeof (re_dfastate_t *), SBC_MAX);
+	  return 1;
+	}
+      return 0;
+    }
+
+  err = re_node_set_alloc (&follows, ndests + 1);
+  if (BE (err != REG_NOERROR, 0))
+    goto out_free;
+
+  /* Avoid arithmetic overflow in size calculation.  */
+  if (BE ((((SIZE_MAX - (sizeof (re_node_set) + sizeof (bitset_t)) * SBC_MAX)
+	    / (3 * sizeof (re_dfastate_t *)))
+	   < (size_t)ndests),
+	  0))
+    goto out_free;
+
+#ifdef HAVE_ALLOCA
+  if (__libc_use_alloca ((sizeof (re_node_set) + sizeof (bitset_t)) * SBC_MAX
+			 + ndests * 3 * sizeof (re_dfastate_t *)))
+    dest_states = (re_dfastate_t **)
+      alloca (ndests * 3 * sizeof (re_dfastate_t *));
+  else
+#endif
+    {
+      dest_states = (re_dfastate_t **)
+	malloc (ndests * 3 * sizeof (re_dfastate_t *));
+      if (BE (dest_states == NULL, 0))
+	{
+out_free:
+	  if (dest_states_malloced)
+	    free (dest_states);
+	  re_node_set_free (&follows);
+	  for (i = 0; i < ndests; ++i)
+	    re_node_set_free (dests_node + i);
+	  if (dests_node_malloced)
+	    free (dests_alloc);
+	  return 0;
+	}
+      dest_states_malloced = true;
+    }
+  dest_states_word = dest_states + ndests;
+  dest_states_nl = dest_states_word + ndests;
+  bitset_empty (acceptable);
+
+  /* Then build the states for all destinations.  */
+  for (i = 0; i < ndests; ++i)
+    {
+      int next_node;
+      re_node_set_empty (&follows);
+      /* Merge the follows of this destination states.  */
+      for (j = 0; j < dests_node[i].nelem; ++j)
+	{
+	  next_node = dfa->nexts[dests_node[i].elems[j]];
+	  if (next_node != -1)
+	    {
+	      err = re_node_set_merge (&follows, dfa->eclosures + next_node);
+	      if (BE (err != REG_NOERROR, 0))
+		goto out_free;
+	    }
+	}
+      dest_states[i] = re_acquire_state_context (&err, dfa, &follows, 0);
+      if (BE (dest_states[i] == NULL && err != REG_NOERROR, 0))
+	goto out_free;
+      /* If the new state has context constraint,
+	 build appropriate states for these contexts.  */
+      if (dest_states[i]->has_constraint)
+	{
+	  dest_states_word[i] = re_acquire_state_context (&err, dfa, &follows,
+							  CONTEXT_WORD);
+	  if (BE (dest_states_word[i] == NULL && err != REG_NOERROR, 0))
+	    goto out_free;
+
+	  if (dest_states[i] != dest_states_word[i] && dfa->mb_cur_max > 1)
+	    need_word_trtable = 1;
+
+	  dest_states_nl[i] = re_acquire_state_context (&err, dfa, &follows,
+							CONTEXT_NEWLINE);
+	  if (BE (dest_states_nl[i] == NULL && err != REG_NOERROR, 0))
+	    goto out_free;
+ 	}
+      else
+	{
+	  dest_states_word[i] = dest_states[i];
+	  dest_states_nl[i] = dest_states[i];
+	}
+      bitset_merge (acceptable, dests_ch[i]);
+    }
+
+  if (!BE (need_word_trtable, 0))
+    {
+      /* We don't care about whether the following character is a word
+	 character, or we are in a single-byte character set so we can
+	 discern by looking at the character code: allocate a
+	 256-entry transition table.  */
+      trtable = state->trtable =
+	(re_dfastate_t **) calloc (sizeof (re_dfastate_t *), SBC_MAX);
+      if (BE (trtable == NULL, 0))
+	goto out_free;
+
+      /* For all characters ch...:  */
+      for (i = 0; i < BITSET_WORDS; ++i)
+	for (ch = i * BITSET_WORD_BITS, elem = acceptable[i], mask = 1;
+	     elem;
+	     mask <<= 1, elem >>= 1, ++ch)
+	  if (BE (elem & 1, 0))
+	    {
+	      /* There must be exactly one destination which accepts
+		 character ch.  See group_nodes_into_DFAstates.  */
+	      for (j = 0; (dests_ch[j][i] & mask) == 0; ++j)
+		;
+
+	      /* j-th destination accepts the word character ch.  */
+	      if (dfa->word_char[i] & mask)
+		trtable[ch] = dest_states_word[j];
+	      else
+		trtable[ch] = dest_states[j];
+	    }
+    }
+  else
+    {
+      /* We care about whether the following character is a word
+	 character, and we are in a multi-byte character set: discern
+	 by looking at the character code: build two 256-entry
+	 transition tables, one starting at trtable[0] and one
+	 starting at trtable[SBC_MAX].  */
+      trtable = state->word_trtable =
+	(re_dfastate_t **) calloc (sizeof (re_dfastate_t *), 2 * SBC_MAX);
+      if (BE (trtable == NULL, 0))
+	goto out_free;
+
+      /* For all characters ch...:  */
+      for (i = 0; i < BITSET_WORDS; ++i)
+	for (ch = i * BITSET_WORD_BITS, elem = acceptable[i], mask = 1;
+	     elem;
+	     mask <<= 1, elem >>= 1, ++ch)
+	  if (BE (elem & 1, 0))
+	    {
+	      /* There must be exactly one destination which accepts
+		 character ch.  See group_nodes_into_DFAstates.  */
+	      for (j = 0; (dests_ch[j][i] & mask) == 0; ++j)
+		;
+
+	      /* j-th destination accepts the word character ch.  */
+	      trtable[ch] = dest_states[j];
+	      trtable[ch + SBC_MAX] = dest_states_word[j];
+	    }
+    }
+
+  /* new line */
+  if (bitset_contain (acceptable, NEWLINE_CHAR))
+    {
+      /* The current state accepts newline character.  */
+      for (j = 0; j < ndests; ++j)
+	if (bitset_contain (dests_ch[j], NEWLINE_CHAR))
+	  {
+	    /* k-th destination accepts newline character.  */
+	    trtable[NEWLINE_CHAR] = dest_states_nl[j];
+	    if (need_word_trtable)
+	      trtable[NEWLINE_CHAR + SBC_MAX] = dest_states_nl[j];
+	    /* There must be only one destination which accepts
+	       newline.  See group_nodes_into_DFAstates.  */
+	    break;
+	  }
+    }
+
+  if (dest_states_malloced)
+    free (dest_states);
+
+  re_node_set_free (&follows);
+  for (i = 0; i < ndests; ++i)
+    re_node_set_free (dests_node + i);
+
+  if (dests_node_malloced)
+    free (dests_alloc);
+
+  return 1;
+}
+
+/* Group all nodes belonging to STATE into several destinations.
+   Then for all destinations, set the nodes belonging to the destination
+   to DESTS_NODE[i] and set the characters accepted by the destination
+   to DEST_CH[i].  This function return the number of destinations.  */
+
+static int
+internal_function
+group_nodes_into_DFAstates (const re_dfa_t *dfa, const re_dfastate_t *state,
+			    re_node_set *dests_node, bitset_t *dests_ch)
+{
+  reg_errcode_t err;
+  int result;
+  int i, j, k;
+  int ndests; /* Number of the destinations from `state'.  */
+  bitset_t accepts; /* Characters a node can accept.  */
+  const re_node_set *cur_nodes = &state->nodes;
+  bitset_empty (accepts);
+  ndests = 0;
+
+  /* For all the nodes belonging to `state',  */
+  for (i = 0; i < cur_nodes->nelem; ++i)
+    {
+      re_token_t *node = &dfa->nodes[cur_nodes->elems[i]];
+      re_token_type_t type = node->type;
+      unsigned int constraint = node->constraint;
+
+      /* Enumerate all single byte character this node can accept.  */
+      if (type == CHARACTER)
+	bitset_set (accepts, node->opr.c);
+      else if (type == SIMPLE_BRACKET)
+	{
+	  bitset_merge (accepts, node->opr.sbcset);
+	}
+      else if (type == OP_PERIOD)
+	{
+#ifdef RE_ENABLE_I18N
+	  if (dfa->mb_cur_max > 1)
+	    bitset_merge (accepts, dfa->sb_char);
+	  else
+#endif
+	    bitset_set_all (accepts);
+	  if (!(dfa->syntax & RE_DOT_NEWLINE))
+	    bitset_clear (accepts, '\n');
+	  if (dfa->syntax & RE_DOT_NOT_NULL)
+	    bitset_clear (accepts, '\0');
+	}
+#ifdef RE_ENABLE_I18N
+      else if (type == OP_UTF8_PERIOD)
+	{
+	  memset (accepts, '\xff', sizeof (bitset_t) / 2);
+	  if (!(dfa->syntax & RE_DOT_NEWLINE))
+	    bitset_clear (accepts, '\n');
+	  if (dfa->syntax & RE_DOT_NOT_NULL)
+	    bitset_clear (accepts, '\0');
+	}
+#endif
+      else
+	continue;
+
+      /* Check the `accepts' and sift the characters which are not
+	 match it the context.  */
+      if (constraint)
+	{
+	  if (constraint & NEXT_NEWLINE_CONSTRAINT)
+	    {
+	      bool accepts_newline = bitset_contain (accepts, NEWLINE_CHAR);
+	      bitset_empty (accepts);
+	      if (accepts_newline)
+		bitset_set (accepts, NEWLINE_CHAR);
+	      else
+		continue;
+	    }
+	  if (constraint & NEXT_ENDBUF_CONSTRAINT)
+	    {
+	      bitset_empty (accepts);
+	      continue;
+	    }
+
+	  if (constraint & NEXT_WORD_CONSTRAINT)
+	    {
+	      bitset_word_t any_set = 0;
+	      if (type == CHARACTER && !node->word_char)
+		{
+		  bitset_empty (accepts);
+		  continue;
+		}
+#ifdef RE_ENABLE_I18N
+	      if (dfa->mb_cur_max > 1)
+		for (j = 0; j < BITSET_WORDS; ++j)
+		  any_set |= (accepts[j] &= (dfa->word_char[j] | ~dfa->sb_char[j]));
+	      else
+#endif
+		for (j = 0; j < BITSET_WORDS; ++j)
+		  any_set |= (accepts[j] &= dfa->word_char[j]);
+	      if (!any_set)
+		continue;
+	    }
+	  if (constraint & NEXT_NOTWORD_CONSTRAINT)
+	    {
+	      bitset_word_t any_set = 0;
+	      if (type == CHARACTER && node->word_char)
+		{
+		  bitset_empty (accepts);
+		  continue;
+		}
+#ifdef RE_ENABLE_I18N
+	      if (dfa->mb_cur_max > 1)
+		for (j = 0; j < BITSET_WORDS; ++j)
+		  any_set |= (accepts[j] &= ~(dfa->word_char[j] & dfa->sb_char[j]));
+	      else
+#endif
+		for (j = 0; j < BITSET_WORDS; ++j)
+		  any_set |= (accepts[j] &= ~dfa->word_char[j]);
+	      if (!any_set)
+		continue;
+	    }
+	}
+
+      /* Then divide `accepts' into DFA states, or create a new
+	 state.  Above, we make sure that accepts is not empty.  */
+      for (j = 0; j < ndests; ++j)
+	{
+	  bitset_t intersec; /* Intersection sets, see below.  */
+	  bitset_t remains;
+	  /* Flags, see below.  */
+	  bitset_word_t has_intersec, not_subset, not_consumed;
+
+	  /* Optimization, skip if this state doesn't accept the character.  */
+	  if (type == CHARACTER && !bitset_contain (dests_ch[j], node->opr.c))
+	    continue;
+
+	  /* Enumerate the intersection set of this state and `accepts'.  */
+	  has_intersec = 0;
+	  for (k = 0; k < BITSET_WORDS; ++k)
+	    has_intersec |= intersec[k] = accepts[k] & dests_ch[j][k];
+	  /* And skip if the intersection set is empty.  */
+	  if (!has_intersec)
+	    continue;
+
+	  /* Then check if this state is a subset of `accepts'.  */
+	  not_subset = not_consumed = 0;
+	  for (k = 0; k < BITSET_WORDS; ++k)
+	    {
+	      not_subset |= remains[k] = ~accepts[k] & dests_ch[j][k];
+	      not_consumed |= accepts[k] = accepts[k] & ~dests_ch[j][k];
+	    }
+
+	  /* If this state isn't a subset of `accepts', create a
+	     new group state, which has the `remains'. */
+	  if (not_subset)
+	    {
+	      bitset_copy (dests_ch[ndests], remains);
+	      bitset_copy (dests_ch[j], intersec);
+	      err = re_node_set_init_copy (dests_node + ndests, &dests_node[j]);
+	      if (BE (err != REG_NOERROR, 0))
+		goto error_return;
+	      ++ndests;
+	    }
+
+	  /* Put the position in the current group. */
+	  result = re_node_set_insert (&dests_node[j], cur_nodes->elems[i]);
+	  if (BE (result < 0, 0))
+	    goto error_return;
+
+	  /* If all characters are consumed, go to next node. */
+	  if (!not_consumed)
+	    break;
+	}
+      /* Some characters remain, create a new group. */
+      if (j == ndests)
+	{
+	  bitset_copy (dests_ch[ndests], accepts);
+	  err = re_node_set_init_1 (dests_node + ndests, cur_nodes->elems[i]);
+	  if (BE (err != REG_NOERROR, 0))
+	    goto error_return;
+	  ++ndests;
+	  bitset_empty (accepts);
+	}
+    }
+  return ndests;
+ error_return:
+  for (j = 0; j < ndests; ++j)
+    re_node_set_free (dests_node + j);
+  return -1;
+}
+
+#ifdef RE_ENABLE_I18N
+/* Check how many bytes the node `dfa->nodes[node_idx]' accepts.
+   Return the number of the bytes the node accepts.
+   STR_IDX is the current index of the input string.
+
+   This function handles the nodes which can accept one character, or
+   one collating element like '.', '[a-z]', opposite to the other nodes
+   can only accept one byte.  */
+
+static int
+internal_function
+check_node_accept_bytes (const re_dfa_t *dfa, int node_idx,
+			 const re_string_t *input, int str_idx)
+{
+  const re_token_t *node = dfa->nodes + node_idx;
+  int char_len, elem_len;
+  int i;
+  wint_t wc;
+
+  if (BE (node->type == OP_UTF8_PERIOD, 0))
+    {
+      unsigned char c = re_string_byte_at (input, str_idx), d;
+      if (BE (c < 0xc2, 1))
+	return 0;
+
+      if (str_idx + 2 > input->len)
+	return 0;
+
+      d = re_string_byte_at (input, str_idx + 1);
+      if (c < 0xe0)
+	return (d < 0x80 || d > 0xbf) ? 0 : 2;
+      else if (c < 0xf0)
+	{
+	  char_len = 3;
+	  if (c == 0xe0 && d < 0xa0)
+	    return 0;
+	}
+      else if (c < 0xf8)
+	{
+	  char_len = 4;
+	  if (c == 0xf0 && d < 0x90)
+	    return 0;
+	}
+      else if (c < 0xfc)
+	{
+	  char_len = 5;
+	  if (c == 0xf8 && d < 0x88)
+	    return 0;
+	}
+      else if (c < 0xfe)
+	{
+	  char_len = 6;
+	  if (c == 0xfc && d < 0x84)
+	    return 0;
+	}
+      else
+	return 0;
+
+      if (str_idx + char_len > input->len)
+	return 0;
+
+      for (i = 1; i < char_len; ++i)
+	{
+	  d = re_string_byte_at (input, str_idx + i);
+	  if (d < 0x80 || d > 0xbf)
+	    return 0;
+	}
+      return char_len;
+    }
+
+  char_len = re_string_char_size_at (input, str_idx);
+  if (node->type == OP_PERIOD)
+    {
+      if (char_len <= 1)
+	return 0;
+      /* FIXME: I don't think this if is needed, as both '\n'
+	 and '\0' are char_len == 1.  */
+      /* '.' accepts any one character except the following two cases.  */
+      if ((!(dfa->syntax & RE_DOT_NEWLINE) &&
+	   re_string_byte_at (input, str_idx) == '\n') ||
+	  ((dfa->syntax & RE_DOT_NOT_NULL) &&
+	   re_string_byte_at (input, str_idx) == '\0'))
+	return 0;
+      return char_len;
+    }
+
+  elem_len = re_string_elem_size_at (input, str_idx);
+  wc = __btowc(*(input->mbs+str_idx));
+  if (((elem_len <= 1 && char_len <= 1) || char_len == 0) && (wc != WEOF && wc < SBC_MAX))
+    return 0;
+
+  if (node->type == COMPLEX_BRACKET)
+    {
+      const re_charset_t *cset = node->opr.mbcset;
+# ifdef _LIBC
+      const unsigned char *pin
+	= ((const unsigned char *) re_string_get_buffer (input) + str_idx);
+      int j;
+      uint32_t nrules;
+# endif /* _LIBC */
+      int match_len = 0;
+      wchar_t wc = ((cset->nranges || cset->nchar_classes || cset->nmbchars)
+		    ? re_string_wchar_at (input, str_idx) : 0);
+
+      /* match with multibyte character?  */
+      for (i = 0; i < cset->nmbchars; ++i)
+	if (wc == cset->mbchars[i])
+	  {
+	    match_len = char_len;
+	    goto check_node_accept_bytes_match;
+	  }
+      /* match with character_class?  */
+      for (i = 0; i < cset->nchar_classes; ++i)
+	{
+	  wctype_t wt = cset->char_classes[i];
+	  if (__iswctype (wc, wt))
+	    {
+	      match_len = char_len;
+	      goto check_node_accept_bytes_match;
+	    }
+	}
+
+# ifdef _LIBC
+      nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+      if (nrules != 0)
+	{
+	  unsigned int in_collseq = 0;
+	  const int32_t *table, *indirect;
+	  const unsigned char *weights, *extra;
+	  const char *collseqwc;
+	  /* This #include defines a local function!  */
+#  include <locale/weight.h>
+
+	  /* match with collating_symbol?  */
+	  if (cset->ncoll_syms)
+	    extra = (const unsigned char *)
+	      _NL_CURRENT (LC_COLLATE, _NL_COLLATE_SYMB_EXTRAMB);
+	  for (i = 0; i < cset->ncoll_syms; ++i)
+	    {
+	      const unsigned char *coll_sym = extra + cset->coll_syms[i];
+	      /* Compare the length of input collating element and
+		 the length of current collating element.  */
+	      if (*coll_sym != elem_len)
+		continue;
+	      /* Compare each bytes.  */
+	      for (j = 0; j < *coll_sym; j++)
+		if (pin[j] != coll_sym[1 + j])
+		  break;
+	      if (j == *coll_sym)
+		{
+		  /* Match if every bytes is equal.  */
+		  match_len = j;
+		  goto check_node_accept_bytes_match;
+		}
+	    }
+
+	  if (cset->nranges)
+	    {
+	      if (elem_len <= char_len)
+		{
+		  collseqwc = _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQWC);
+		  in_collseq = __collseq_table_lookup (collseqwc, wc);
+		}
+	      else
+		in_collseq = find_collation_sequence_value (pin, elem_len);
+	    }
+	  /* match with range expression?  */
+	  for (i = 0; i < cset->nranges; ++i)
+	    if (cset->range_starts[i] <= in_collseq
+		&& in_collseq <= cset->range_ends[i])
+	      {
+		match_len = elem_len;
+		goto check_node_accept_bytes_match;
+	      }
+
+	  /* match with equivalence_class?  */
+	  if (cset->nequiv_classes)
+	    {
+	      const unsigned char *cp = pin;
+	      table = (const int32_t *)
+		_NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEMB);
+	      weights = (const unsigned char *)
+		_NL_CURRENT (LC_COLLATE, _NL_COLLATE_WEIGHTMB);
+	      extra = (const unsigned char *)
+		_NL_CURRENT (LC_COLLATE, _NL_COLLATE_EXTRAMB);
+	      indirect = (const int32_t *)
+		_NL_CURRENT (LC_COLLATE, _NL_COLLATE_INDIRECTMB);
+	      int32_t idx = findidx (&cp);
+	      if (idx > 0)
+		for (i = 0; i < cset->nequiv_classes; ++i)
+		  {
+		    int32_t equiv_class_idx = cset->equiv_classes[i];
+		    size_t weight_len = weights[idx & 0xffffff];
+		    if (weight_len == weights[equiv_class_idx & 0xffffff]
+			&& (idx >> 24) == (equiv_class_idx >> 24))
+		      {
+			int cnt = 0;
+
+			idx &= 0xffffff;
+			equiv_class_idx &= 0xffffff;
+
+			while (cnt <= weight_len
+			       && (weights[equiv_class_idx + 1 + cnt]
+				   == weights[idx + 1 + cnt]))
+			  ++cnt;
+			if (cnt > weight_len)
+			  {
+			    match_len = elem_len;
+			    goto check_node_accept_bytes_match;
+			  }
+		      }
+		  }
+	    }
+	}
+      else
+# endif /* _LIBC */
+	{
+	  /* match with range expression?  */
+#if __GNUC__ >= 2
+	  wchar_t cmp_buf[] = {L'\0', L'\0', wc, L'\0', L'\0', L'\0'};
+#else
+	  wchar_t cmp_buf[] = {L'\0', L'\0', L'\0', L'\0', L'\0', L'\0'};
+	  cmp_buf[2] = wc;
+#endif
+	  for (i = 0; i < cset->nranges; ++i)
+	    {
+	      cmp_buf[0] = cset->range_starts[i];
+	      cmp_buf[4] = cset->range_ends[i];
+	      if (wcscoll (cmp_buf, cmp_buf + 2) <= 0
+		  && wcscoll (cmp_buf + 2, cmp_buf + 4) <= 0)
+		{
+		  match_len = char_len;
+		  goto check_node_accept_bytes_match;
+		}
+	    }
+	}
+    check_node_accept_bytes_match:
+      if (!cset->non_match)
+	return match_len;
+      else
+	{
+	  if (match_len > 0)
+	    return 0;
+	  else
+	    return (elem_len > char_len) ? elem_len : char_len;
+	}
+    }
+  return 0;
+}
+
+# ifdef _LIBC
+static unsigned int
+internal_function
+find_collation_sequence_value (const unsigned char *mbs, size_t mbs_len)
+{
+  uint32_t nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+  if (nrules == 0)
+    {
+      if (mbs_len == 1)
+	{
+	  /* No valid character.  Match it as a single byte character.  */
+	  const unsigned char *collseq = (const unsigned char *)
+	    _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQMB);
+	  return collseq[mbs[0]];
+	}
+      return UINT_MAX;
+    }
+  else
+    {
+      int32_t idx;
+      const unsigned char *extra = (const unsigned char *)
+	_NL_CURRENT (LC_COLLATE, _NL_COLLATE_SYMB_EXTRAMB);
+      int32_t extrasize = (const unsigned char *)
+	_NL_CURRENT (LC_COLLATE, _NL_COLLATE_SYMB_EXTRAMB + 1) - extra;
+
+      for (idx = 0; idx < extrasize;)
+	{
+	  int mbs_cnt, found = 0;
+	  int32_t elem_mbs_len;
+	  /* Skip the name of collating element name.  */
+	  idx = idx + extra[idx] + 1;
+	  elem_mbs_len = extra[idx++];
+	  if (mbs_len == elem_mbs_len)
+	    {
+	      for (mbs_cnt = 0; mbs_cnt < elem_mbs_len; ++mbs_cnt)
+		if (extra[idx + mbs_cnt] != mbs[mbs_cnt])
+		  break;
+	      if (mbs_cnt == elem_mbs_len)
+		/* Found the entry.  */
+		found = 1;
+	    }
+	  /* Skip the byte sequence of the collating element.  */
+	  idx += elem_mbs_len;
+	  /* Adjust for the alignment.  */
+	  idx = (idx + 3) & ~3;
+	  /* Skip the collation sequence value.  */
+	  idx += sizeof (uint32_t);
+	  /* Skip the wide char sequence of the collating element.  */
+	  idx = idx + sizeof (uint32_t) * (extra[idx] + 1);
+	  /* If we found the entry, return the sequence value.  */
+	  if (found)
+	    return *(uint32_t *) (extra + idx);
+	  /* Skip the collation sequence value.  */
+	  idx += sizeof (uint32_t);
+	}
+      return UINT_MAX;
+    }
+}
+# endif /* _LIBC */
+#endif /* RE_ENABLE_I18N */
+
+/* Check whether the node accepts the byte which is IDX-th
+   byte of the INPUT.  */
+
+static int
+internal_function
+check_node_accept (const re_match_context_t *mctx, const re_token_t *node,
+		   int idx)
+{
+  unsigned char ch;
+  ch = re_string_byte_at (&mctx->input, idx);
+  switch (node->type)
+    {
+    case CHARACTER:
+      if (node->opr.c != ch)
+	return 0;
+      break;
+
+    case SIMPLE_BRACKET:
+      if (!bitset_contain (node->opr.sbcset, ch))
+	return 0;
+      break;
+
+#ifdef RE_ENABLE_I18N
+    case OP_UTF8_PERIOD:
+      if (ch >= 0x80)
+	return 0;
+      /* FALLTHROUGH */
+#endif
+    case OP_PERIOD:
+      if ((ch == '\n' && !(mctx->dfa->syntax & RE_DOT_NEWLINE))
+	  || (ch == '\0' && (mctx->dfa->syntax & RE_DOT_NOT_NULL)))
+	return 0;
+      break;
+
+    default:
+      return 0;
+    }
+
+  if (node->constraint)
+    {
+      /* The node has constraints.  Check whether the current context
+	 satisfies the constraints.  */
+      unsigned int context = re_string_context_at (&mctx->input, idx,
+						   mctx->eflags);
+      if (NOT_SATISFY_NEXT_CONSTRAINT (node->constraint, context))
+	return 0;
+    }
+
+  return 1;
+}
+
+/* Extend the buffers, if the buffers have run out.  */
+
+static reg_errcode_t
+internal_function
+extend_buffers (re_match_context_t *mctx)
+{
+  reg_errcode_t ret;
+  re_string_t *pstr = &mctx->input;
+
+  /* Avoid overflow.  */
+  if (BE (INT_MAX / 2 / sizeof (re_dfastate_t *) <= (size_t)pstr->bufs_len, 0))
+    return REG_ESPACE;
+
+  /* Double the lengthes of the buffers.  */
+  ret = re_string_realloc_buffers (pstr, pstr->bufs_len * 2);
+  if (BE (ret != REG_NOERROR, 0))
+    return ret;
+
+  if (mctx->state_log != NULL)
+    {
+      /* And double the length of state_log.  */
+      /* XXX We have no indication of the size of this buffer.  If this
+	 allocation fail we have no indication that the state_log array
+	 does not have the right size.  */
+      re_dfastate_t **new_array = re_realloc (mctx->state_log, re_dfastate_t *,
+					      pstr->bufs_len + 1);
+      if (BE (new_array == NULL, 0))
+	return REG_ESPACE;
+      mctx->state_log = new_array;
+    }
+
+  /* Then reconstruct the buffers.  */
+  if (pstr->icase)
+    {
+#ifdef RE_ENABLE_I18N
+      if (pstr->mb_cur_max > 1)
+	{
+	  ret = build_wcs_upper_buffer (pstr);
+	  if (BE (ret != REG_NOERROR, 0))
+	    return ret;
+	}
+      else
+#endif /* RE_ENABLE_I18N  */
+	build_upper_buffer (pstr);
+    }
+  else
+    {
+#ifdef RE_ENABLE_I18N
+      if (pstr->mb_cur_max > 1)
+	build_wcs_buffer (pstr);
+      else
+#endif /* RE_ENABLE_I18N  */
+	{
+	  if (pstr->trans != NULL)
+	    re_string_translate_buffer (pstr);
+	}
+    }
+  return REG_NOERROR;
+}
+
+
+/* Functions for matching context.  */
+
+/* Initialize MCTX.  */
+
+static reg_errcode_t
+internal_function
+match_ctx_init (re_match_context_t *mctx, int eflags, int n)
+{
+  mctx->eflags = eflags;
+  mctx->match_last = -1;
+  if (n > 0)
+    {
+      mctx->bkref_ents = re_malloc (struct re_backref_cache_entry, n);
+      mctx->sub_tops = re_malloc (re_sub_match_top_t *, n);
+      if (BE (mctx->bkref_ents == NULL || mctx->sub_tops == NULL, 0))
+	return REG_ESPACE;
+    }
+  /* Already zero-ed by the caller.
+     else
+       mctx->bkref_ents = NULL;
+     mctx->nbkref_ents = 0;
+     mctx->nsub_tops = 0;  */
+  mctx->abkref_ents = n;
+  mctx->max_mb_elem_len = 1;
+  mctx->asub_tops = n;
+  return REG_NOERROR;
+}
+
+/* Clean the entries which depend on the current input in MCTX.
+   This function must be invoked when the matcher changes the start index
+   of the input, or changes the input string.  */
+
+static void
+internal_function
+match_ctx_clean (re_match_context_t *mctx)
+{
+  int st_idx;
+  for (st_idx = 0; st_idx < mctx->nsub_tops; ++st_idx)
+    {
+      int sl_idx;
+      re_sub_match_top_t *top = mctx->sub_tops[st_idx];
+      for (sl_idx = 0; sl_idx < top->nlasts; ++sl_idx)
+	{
+	  re_sub_match_last_t *last = top->lasts[sl_idx];
+	  re_free (last->path.array);
+	  re_free (last);
+	}
+      re_free (top->lasts);
+      if (top->path)
+	{
+	  re_free (top->path->array);
+	  re_free (top->path);
+	}
+      free (top);
+    }
+
+  mctx->nsub_tops = 0;
+  mctx->nbkref_ents = 0;
+}
+
+/* Free all the memory associated with MCTX.  */
+
+static void
+internal_function
+match_ctx_free (re_match_context_t *mctx)
+{
+  /* First, free all the memory associated with MCTX->SUB_TOPS.  */
+  match_ctx_clean (mctx);
+  re_free (mctx->sub_tops);
+  re_free (mctx->bkref_ents);
+}
+
+/* Add a new backreference entry to MCTX.
+   Note that we assume that caller never call this function with duplicate
+   entry, and call with STR_IDX which isn't smaller than any existing entry.
+*/
+
+static reg_errcode_t
+internal_function
+match_ctx_add_entry (re_match_context_t *mctx, int node, int str_idx, int from,
+		     int to)
+{
+  if (mctx->nbkref_ents >= mctx->abkref_ents)
+    {
+      struct re_backref_cache_entry* new_entry;
+      new_entry = re_realloc (mctx->bkref_ents, struct re_backref_cache_entry,
+			      mctx->abkref_ents * 2);
+      if (BE (new_entry == NULL, 0))
+	{
+	  re_free (mctx->bkref_ents);
+	  return REG_ESPACE;
+	}
+      mctx->bkref_ents = new_entry;
+      memset (mctx->bkref_ents + mctx->nbkref_ents, '\0',
+	      sizeof (struct re_backref_cache_entry) * mctx->abkref_ents);
+      mctx->abkref_ents *= 2;
+    }
+  if (mctx->nbkref_ents > 0
+      && mctx->bkref_ents[mctx->nbkref_ents - 1].str_idx == str_idx)
+    mctx->bkref_ents[mctx->nbkref_ents - 1].more = 1;
+
+  mctx->bkref_ents[mctx->nbkref_ents].node = node;
+  mctx->bkref_ents[mctx->nbkref_ents].str_idx = str_idx;
+  mctx->bkref_ents[mctx->nbkref_ents].subexp_from = from;
+  mctx->bkref_ents[mctx->nbkref_ents].subexp_to = to;
+
+  /* This is a cache that saves negative results of check_dst_limits_calc_pos.
+     If bit N is clear, means that this entry won't epsilon-transition to
+     an OP_OPEN_SUBEXP or OP_CLOSE_SUBEXP for the N+1-th subexpression.  If
+     it is set, check_dst_limits_calc_pos_1 will recurse and try to find one
+     such node.
+
+     A backreference does not epsilon-transition unless it is empty, so set
+     to all zeros if FROM != TO.  */
+  mctx->bkref_ents[mctx->nbkref_ents].eps_reachable_subexps_map
+    = (from == to ? ~0 : 0);
+
+  mctx->bkref_ents[mctx->nbkref_ents++].more = 0;
+  if (mctx->max_mb_elem_len < to - from)
+    mctx->max_mb_elem_len = to - from;
+  return REG_NOERROR;
+}
+
+/* Search for the first entry which has the same str_idx, or -1 if none is
+   found.  Note that MCTX->BKREF_ENTS is already sorted by MCTX->STR_IDX.  */
+
+static int
+internal_function
+search_cur_bkref_entry (const re_match_context_t *mctx, int str_idx)
+{
+  int left, right, mid, last;
+  last = right = mctx->nbkref_ents;
+  for (left = 0; left < right;)
+    {
+      mid = (left + right) / 2;
+      if (mctx->bkref_ents[mid].str_idx < str_idx)
+	left = mid + 1;
+      else
+	right = mid;
+    }
+  if (left < last && mctx->bkref_ents[left].str_idx == str_idx)
+    return left;
+  else
+    return -1;
+}
+
+/* Register the node NODE, whose type is OP_OPEN_SUBEXP, and which matches
+   at STR_IDX.  */
+
+static reg_errcode_t
+internal_function
+match_ctx_add_subtop (re_match_context_t *mctx, int node, int str_idx)
+{
+#ifdef DEBUG
+  assert (mctx->sub_tops != NULL);
+  assert (mctx->asub_tops > 0);
+#endif
+  if (BE (mctx->nsub_tops == mctx->asub_tops, 0))
+    {
+      int new_asub_tops = mctx->asub_tops * 2;
+      re_sub_match_top_t **new_array = re_realloc (mctx->sub_tops,
+						   re_sub_match_top_t *,
+						   new_asub_tops);
+      if (BE (new_array == NULL, 0))
+	return REG_ESPACE;
+      mctx->sub_tops = new_array;
+      mctx->asub_tops = new_asub_tops;
+    }
+  mctx->sub_tops[mctx->nsub_tops] = calloc (1, sizeof (re_sub_match_top_t));
+  if (BE (mctx->sub_tops[mctx->nsub_tops] == NULL, 0))
+    return REG_ESPACE;
+  mctx->sub_tops[mctx->nsub_tops]->node = node;
+  mctx->sub_tops[mctx->nsub_tops++]->str_idx = str_idx;
+  return REG_NOERROR;
+}
+
+/* Register the node NODE, whose type is OP_CLOSE_SUBEXP, and which matches
+   at STR_IDX, whose corresponding OP_OPEN_SUBEXP is SUB_TOP.  */
+
+static re_sub_match_last_t *
+internal_function
+match_ctx_add_sublast (re_sub_match_top_t *subtop, int node, int str_idx)
+{
+  re_sub_match_last_t *new_entry;
+  if (BE (subtop->nlasts == subtop->alasts, 0))
+    {
+      int new_alasts = 2 * subtop->alasts + 1;
+      re_sub_match_last_t **new_array = re_realloc (subtop->lasts,
+						    re_sub_match_last_t *,
+						    new_alasts);
+      if (BE (new_array == NULL, 0))
+	return NULL;
+      subtop->lasts = new_array;
+      subtop->alasts = new_alasts;
+    }
+  new_entry = calloc (1, sizeof (re_sub_match_last_t));
+  if (BE (new_entry != NULL, 1))
+    {
+      subtop->lasts[subtop->nlasts] = new_entry;
+      new_entry->node = node;
+      new_entry->str_idx = str_idx;
+      ++subtop->nlasts;
+    }
+  return new_entry;
+}
+
+static void
+internal_function
+sift_ctx_init (re_sift_context_t *sctx, re_dfastate_t **sifted_sts,
+	       re_dfastate_t **limited_sts, int last_node, int last_str_idx)
+{
+  sctx->sifted_states = sifted_sts;
+  sctx->limited_states = limited_sts;
+  sctx->last_node = last_node;
+  sctx->last_str_idx = last_str_idx;
+  re_node_set_init_empty (&sctx->limits);
+}

vendor/libgit2-sys/libgit2/deps/winhttp/CMakeLists.txt

diff --git a/vendor/libgit2-sys/libgit2/deps/winhttp/CMakeLists.txt b/vendor/libgit2-sys/libgit2/deps/winhttp/CMakeLists.txt
new file mode 100644
index 0000000..148ac3e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/winhttp/CMakeLists.txt
@@ -0,0 +1,26 @@
+FIND_PROGRAM(DLLTOOL dlltool CMAKE_FIND_ROOT_PATH_BOTH)
+IF (NOT DLLTOOL)
+	MESSAGE(FATAL_ERROR "Could not find dlltool command")
+ENDIF ()
+
+SET(LIBWINHTTP_PATH "${libgit2_BINARY_DIR}/deps/winhttp")
+SET(LIBWINHTTP_PATH ${LIBWINHTTP_PATH} PARENT_SCOPE)
+FILE(MAKE_DIRECTORY ${LIBWINHTTP_PATH})
+
+IF (CMAKE_SIZEOF_VOID_P EQUAL 8)
+	set(WINHTTP_DEF "winhttp64.def")
+ELSE()
+	set(WINHTTP_DEF "winhttp.def")
+ENDIF()
+
+ADD_CUSTOM_COMMAND(
+	OUTPUT ${LIBWINHTTP_PATH}/libwinhttp.a
+	COMMAND ${DLLTOOL} -d ${WINHTTP_DEF} -k -D winhttp.dll -l libwinhttp.a
+	DEPENDS ${WINHTTP_DEF}
+	WORKING_DIRECTORY ${LIBWINHTTP_PATH}
+)
+
+SET_SOURCE_FILES_PROPERTIES(
+	${CMAKE_CURRENT_SOURCE_DIR}/src/transports/winhttp.c
+	PROPERTIES OBJECT_DEPENDS ${LIBWINHTTP_PATH}/libwinhttp.a
+)

vendor/libgit2-sys/libgit2/deps/winhttp/urlmon.h

diff --git a/vendor/libgit2-sys/libgit2/deps/winhttp/urlmon.h b/vendor/libgit2-sys/libgit2/deps/winhttp/urlmon.h
new file mode 100644
index 0000000..4143d50
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/winhttp/urlmon.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#if defined(__MINGW_VERSION) || defined(__MINGW32_VERSION)
+
+#ifndef __CUSTOM_URLMON_H
+#define __CUSTOM_URLMON_H
+
+typedef struct IInternetSecurityManager IInternetSecurityManager;
+
+typedef struct IInternetSecurityManagerVtbl
+{
+	HRESULT(STDMETHODCALLTYPE *QueryInterface)(IInternetSecurityManager *, REFIID, void **);
+	ULONG(STDMETHODCALLTYPE *AddRef)(IInternetSecurityManager *);
+	ULONG(STDMETHODCALLTYPE *Release)(IInternetSecurityManager *);
+	LPVOID SetSecuritySite;
+	LPVOID GetSecuritySite;
+	HRESULT(STDMETHODCALLTYPE *MapUrlToZone)(IInternetSecurityManager *, LPCWSTR, DWORD *, DWORD);
+	LPVOID GetSecurityId;
+	LPVOID ProcessUrlAction;
+	LPVOID QueryCustomPolicy;
+	LPVOID SetZoneMapping;
+	LPVOID GetZoneMappings;
+} IInternetSecurityManagerVtbl;
+
+struct IInternetSecurityManager
+{
+	CONST_VTBL struct IInternetSecurityManagerVtbl *lpVtbl;
+};
+
+#define URLZONE_LOCAL_MACHINE 0
+#define URLZONE_INTRANET      1
+#define URLZONE_TRUSTED       2
+
+#endif /* __CUSTOM_URLMON_H */
+
+#else
+
+#include_next <urlmon.h>
+
+#endif

vendor/libgit2-sys/libgit2/deps/winhttp/winhttp.def

diff --git a/vendor/libgit2-sys/libgit2/deps/winhttp/winhttp.def b/vendor/libgit2-sys/libgit2/deps/winhttp/winhttp.def
new file mode 100644
index 0000000..eecce59
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/winhttp/winhttp.def
@@ -0,0 +1,29 @@
+LIBRARY		WINHTTP
+EXPORTS
+WinHttpAddRequestHeaders@16
+WinHttpCheckPlatform@0
+WinHttpCloseHandle@4
+WinHttpConnect@16
+WinHttpCrackUrl@16
+WinHttpCreateUrl@16
+WinHttpDetectAutoProxyConfigUrl@8
+WinHttpGetDefaultProxyConfiguration@4
+WinHttpGetIEProxyConfigForCurrentUser@4
+WinHttpGetProxyForUrl@16
+WinHttpOpen@20
+WinHttpOpenRequest@28
+WinHttpQueryAuthSchemes@16
+WinHttpQueryDataAvailable@8
+WinHttpQueryHeaders@24
+WinHttpQueryOption@16
+WinHttpReadData@16
+WinHttpReceiveResponse@8
+WinHttpSendRequest@28
+WinHttpSetCredentials@24
+WinHttpSetDefaultProxyConfiguration@4
+WinHttpSetOption@16
+WinHttpSetStatusCallback@16
+WinHttpSetTimeouts@20
+WinHttpTimeFromSystemTime@8
+WinHttpTimeToSystemTime@8
+WinHttpWriteData@16

vendor/libgit2-sys/libgit2/deps/winhttp/winhttp.h

diff --git a/vendor/libgit2-sys/libgit2/deps/winhttp/winhttp.h b/vendor/libgit2-sys/libgit2/deps/winhttp/winhttp.h
new file mode 100644
index 0000000..b7fef1c
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/winhttp/winhttp.h
@@ -0,0 +1,594 @@
+/*
+ * Copyright (C) 2007 Francois Gouget
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#if defined(__MINGW_VERSION) || defined(__MINGW32_VERSION)
+
+#ifndef __WINE_WINHTTP_H
+#define __WINE_WINHTTP_H
+
+#ifdef _WIN64
+#include <pshpack8.h>
+#else
+#include <pshpack4.h>
+#endif
+
+#define WINHTTPAPI
+#define BOOLAPI WINHTTPAPI BOOL WINAPI
+
+
+typedef LPVOID HINTERNET;
+typedef HINTERNET *LPHINTERNET;
+
+#define INTERNET_DEFAULT_PORT           0
+#define INTERNET_DEFAULT_HTTP_PORT      80
+#define INTERNET_DEFAULT_HTTPS_PORT     443
+typedef WORD INTERNET_PORT;
+typedef INTERNET_PORT *LPINTERNET_PORT;
+
+#define INTERNET_SCHEME_HTTP            1
+#define INTERNET_SCHEME_HTTPS           2
+typedef int INTERNET_SCHEME, *LPINTERNET_SCHEME;
+
+#define ICU_ESCAPE  0x80000000
+
+/* flags for WinHttpOpen */
+#define WINHTTP_FLAG_ASYNC                  0x10000000
+
+/* flags for WinHttpOpenRequest */
+#define WINHTTP_FLAG_ESCAPE_PERCENT         0x00000004
+#define WINHTTP_FLAG_NULL_CODEPAGE          0x00000008
+#define WINHTTP_FLAG_ESCAPE_DISABLE         0x00000040
+#define WINHTTP_FLAG_ESCAPE_DISABLE_QUERY   0x00000080
+#define WINHTTP_FLAG_BYPASS_PROXY_CACHE     0x00000100
+#define WINHTTP_FLAG_REFRESH                WINHTTP_FLAG_BYPASS_PROXY_CACHE
+#define WINHTTP_FLAG_SECURE                 0x00800000
+
+#define WINHTTP_ACCESS_TYPE_DEFAULT_PROXY   0
+#define WINHTTP_ACCESS_TYPE_NO_PROXY        1
+#define WINHTTP_ACCESS_TYPE_NAMED_PROXY     3
+
+#define WINHTTP_NO_PROXY_NAME               NULL
+#define WINHTTP_NO_PROXY_BYPASS             NULL
+
+#define WINHTTP_NO_REFERER                  NULL
+#define WINHTTP_DEFAULT_ACCEPT_TYPES        NULL
+
+#define WINHTTP_NO_ADDITIONAL_HEADERS       NULL
+#define WINHTTP_NO_REQUEST_DATA             NULL
+
+#define WINHTTP_HEADER_NAME_BY_INDEX        NULL
+#define WINHTTP_NO_OUTPUT_BUFFER            NULL
+#define WINHTTP_NO_HEADER_INDEX             NULL
+
+#define WINHTTP_ADDREQ_INDEX_MASK                    0x0000FFFF
+#define WINHTTP_ADDREQ_FLAGS_MASK                    0xFFFF0000
+#define WINHTTP_ADDREQ_FLAG_ADD_IF_NEW               0x10000000
+#define WINHTTP_ADDREQ_FLAG_ADD                      0x20000000
+#define WINHTTP_ADDREQ_FLAG_COALESCE_WITH_COMMA      0x40000000
+#define WINHTTP_ADDREQ_FLAG_COALESCE_WITH_SEMICOLON  0x01000000
+#define WINHTTP_ADDREQ_FLAG_COALESCE                 WINHTTP_ADDREQ_FLAG_COALESCE_WITH_COMMA
+#define WINHTTP_ADDREQ_FLAG_REPLACE                  0x80000000
+
+#define WINHTTP_IGNORE_REQUEST_TOTAL_LENGTH 0
+
+/* flags for WinHttp{Set/Query}Options */
+#define WINHTTP_FIRST_OPTION                         WINHTTP_OPTION_CALLBACK
+#define WINHTTP_OPTION_CALLBACK                       1
+#define WINHTTP_OPTION_RESOLVE_TIMEOUT                2
+#define WINHTTP_OPTION_CONNECT_TIMEOUT                3
+#define WINHTTP_OPTION_CONNECT_RETRIES                4
+#define WINHTTP_OPTION_SEND_TIMEOUT                   5
+#define WINHTTP_OPTION_RECEIVE_TIMEOUT                6
+#define WINHTTP_OPTION_RECEIVE_RESPONSE_TIMEOUT       7
+#define WINHTTP_OPTION_HANDLE_TYPE                    9
+#define WINHTTP_OPTION_READ_BUFFER_SIZE              12
+#define WINHTTP_OPTION_WRITE_BUFFER_SIZE             13
+#define WINHTTP_OPTION_PARENT_HANDLE                 21
+#define WINHTTP_OPTION_EXTENDED_ERROR                24
+#define WINHTTP_OPTION_SECURITY_FLAGS                31
+#define WINHTTP_OPTION_SECURITY_CERTIFICATE_STRUCT   32
+#define WINHTTP_OPTION_URL                           34
+#define WINHTTP_OPTION_SECURITY_KEY_BITNESS          36
+#define WINHTTP_OPTION_PROXY                         38
+#define WINHTTP_OPTION_USER_AGENT                    41
+#define WINHTTP_OPTION_CONTEXT_VALUE                 45
+#define WINHTTP_OPTION_CLIENT_CERT_CONTEXT           47
+#define WINHTTP_OPTION_REQUEST_PRIORITY              58
+#define WINHTTP_OPTION_HTTP_VERSION                  59
+#define WINHTTP_OPTION_DISABLE_FEATURE               63
+#define WINHTTP_OPTION_CODEPAGE                      68
+#define WINHTTP_OPTION_MAX_CONNS_PER_SERVER          73
+#define WINHTTP_OPTION_MAX_CONNS_PER_1_0_SERVER      74
+#define WINHTTP_OPTION_AUTOLOGON_POLICY              77
+#define WINHTTP_OPTION_SERVER_CERT_CONTEXT           78
+#define WINHTTP_OPTION_ENABLE_FEATURE                79
+#define WINHTTP_OPTION_WORKER_THREAD_COUNT           80
+#define WINHTTP_OPTION_PASSPORT_COBRANDING_TEXT      81
+#define WINHTTP_OPTION_PASSPORT_COBRANDING_URL       82
+#define WINHTTP_OPTION_CONFIGURE_PASSPORT_AUTH       83
+#define WINHTTP_OPTION_SECURE_PROTOCOLS              84
+#define WINHTTP_OPTION_ENABLETRACING                 85
+#define WINHTTP_OPTION_PASSPORT_SIGN_OUT             86
+#define WINHTTP_OPTION_PASSPORT_RETURN_URL           87
+#define WINHTTP_OPTION_REDIRECT_POLICY               88
+#define WINHTTP_OPTION_MAX_HTTP_AUTOMATIC_REDIRECTS  89
+#define WINHTTP_OPTION_MAX_HTTP_STATUS_CONTINUE      90
+#define WINHTTP_OPTION_MAX_RESPONSE_HEADER_SIZE      91
+#define WINHTTP_OPTION_MAX_RESPONSE_DRAIN_SIZE       92
+#define WINHTTP_OPTION_CONNECTION_INFO               93
+#define WINHTTP_OPTION_CLIENT_CERT_ISSUER_LIST       94
+#define WINHTTP_OPTION_SPN                           96
+#define WINHTTP_OPTION_GLOBAL_PROXY_CREDS            97
+#define WINHTTP_OPTION_GLOBAL_SERVER_CREDS           98
+#define WINHTTP_OPTION_UNLOAD_NOTIFY_EVENT           99
+#define WINHTTP_OPTION_REJECT_USERPWD_IN_URL         100
+#define WINHTTP_OPTION_USE_GLOBAL_SERVER_CREDENTIALS 101
+#define WINHTTP_LAST_OPTION                          WINHTTP_OPTION_USE_GLOBAL_SERVER_CREDENTIALS
+#define WINHTTP_OPTION_USERNAME                      0x1000
+#define WINHTTP_OPTION_PASSWORD                      0x1001
+#define WINHTTP_OPTION_PROXY_USERNAME                0x1002
+#define WINHTTP_OPTION_PROXY_PASSWORD                0x1003
+
+#define WINHTTP_CONNS_PER_SERVER_UNLIMITED 0xFFFFFFFF
+
+#define WINHTTP_AUTOLOGON_SECURITY_LEVEL_MEDIUM   0
+#define WINHTTP_AUTOLOGON_SECURITY_LEVEL_LOW      1
+#define WINHTTP_AUTOLOGON_SECURITY_LEVEL_HIGH     2
+#define WINHTTP_AUTOLOGON_SECURITY_LEVEL_DEFAULT  WINHTTP_AUTOLOGON_SECURITY_LEVEL_MEDIUM
+
+#define WINHTTP_OPTION_REDIRECT_POLICY_NEVER                        0
+#define WINHTTP_OPTION_REDIRECT_POLICY_DISALLOW_HTTPS_TO_HTTP       1
+#define WINHTTP_OPTION_REDIRECT_POLICY_ALWAYS                       2
+#define WINHTTP_OPTION_REDIRECT_POLICY_LAST            WINHTTP_OPTION_REDIRECT_POLICY_ALWAYS
+#define WINHTTP_OPTION_REDIRECT_POLICY_DEFAULT         WINHTTP_OPTION_REDIRECT_POLICY_DISALLOW_HTTPS_TO_HTTP
+
+#define WINHTTP_DISABLE_PASSPORT_AUTH    0x00000000
+#define WINHTTP_ENABLE_PASSPORT_AUTH     0x10000000
+#define WINHTTP_DISABLE_PASSPORT_KEYRING 0x20000000
+#define WINHTTP_ENABLE_PASSPORT_KEYRING  0x40000000
+
+#define WINHTTP_DISABLE_COOKIES                   0x00000001
+#define WINHTTP_DISABLE_REDIRECTS                 0x00000002
+#define WINHTTP_DISABLE_AUTHENTICATION            0x00000004
+#define WINHTTP_DISABLE_KEEP_ALIVE                0x00000008
+#define WINHTTP_ENABLE_SSL_REVOCATION             0x00000001
+#define WINHTTP_ENABLE_SSL_REVERT_IMPERSONATION   0x00000002
+#define WINHTTP_DISABLE_SPN_SERVER_PORT           0x00000000
+#define WINHTTP_ENABLE_SPN_SERVER_PORT            0x00000001
+#define WINHTTP_OPTION_SPN_MASK                   WINHTTP_ENABLE_SPN_SERVER_PORT
+
+/* Options for WinHttpOpenRequest */
+#define WINHTTP_NO_REFERER             NULL
+#define WINHTTP_DEFAULT_ACCEPT_TYPES   NULL
+
+/* Options for WinHttpSendRequest */
+#define WINHTTP_NO_ADDITIONAL_HEADERS   NULL
+#define WINHTTP_NO_REQUEST_DATA         NULL
+
+/* WinHTTP error codes */
+#define WINHTTP_ERROR_BASE                                  12000
+#define ERROR_WINHTTP_OUT_OF_HANDLES                        (WINHTTP_ERROR_BASE + 1)
+#define ERROR_WINHTTP_TIMEOUT                               (WINHTTP_ERROR_BASE + 2)
+#define ERROR_WINHTTP_INTERNAL_ERROR                        (WINHTTP_ERROR_BASE + 4)
+#define ERROR_WINHTTP_INVALID_URL                           (WINHTTP_ERROR_BASE + 5)
+#define ERROR_WINHTTP_UNRECOGNIZED_SCHEME                   (WINHTTP_ERROR_BASE + 6)
+#define ERROR_WINHTTP_NAME_NOT_RESOLVED                     (WINHTTP_ERROR_BASE + 7)
+#define ERROR_WINHTTP_INVALID_OPTION                        (WINHTTP_ERROR_BASE + 9)
+#define ERROR_WINHTTP_OPTION_NOT_SETTABLE                   (WINHTTP_ERROR_BASE + 11)
+#define ERROR_WINHTTP_SHUTDOWN                              (WINHTTP_ERROR_BASE + 12)
+#define ERROR_WINHTTP_LOGIN_FAILURE                         (WINHTTP_ERROR_BASE + 15)
+#define ERROR_WINHTTP_OPERATION_CANCELLED                   (WINHTTP_ERROR_BASE + 17)
+#define ERROR_WINHTTP_INCORRECT_HANDLE_TYPE                 (WINHTTP_ERROR_BASE + 18)
+#define ERROR_WINHTTP_INCORRECT_HANDLE_STATE                (WINHTTP_ERROR_BASE + 19)
+#define ERROR_WINHTTP_CANNOT_CONNECT                        (WINHTTP_ERROR_BASE + 29)
+#define ERROR_WINHTTP_CONNECTION_ERROR                      (WINHTTP_ERROR_BASE + 30)
+#define ERROR_WINHTTP_RESEND_REQUEST                        (WINHTTP_ERROR_BASE + 32)
+#define ERROR_WINHTTP_SECURE_CERT_DATE_INVALID              (WINHTTP_ERROR_BASE + 37)
+#define ERROR_WINHTTP_SECURE_CERT_CN_INVALID                (WINHTTP_ERROR_BASE + 38)
+#define ERROR_WINHTTP_CLIENT_AUTH_CERT_NEEDED               (WINHTTP_ERROR_BASE + 44)
+#define ERROR_WINHTTP_SECURE_INVALID_CA                     (WINHTTP_ERROR_BASE + 45)
+#define ERROR_WINHTTP_SECURE_CERT_REV_FAILED                (WINHTTP_ERROR_BASE + 57)
+#define ERROR_WINHTTP_CANNOT_CALL_BEFORE_OPEN               (WINHTTP_ERROR_BASE + 100)
+#define ERROR_WINHTTP_CANNOT_CALL_BEFORE_SEND               (WINHTTP_ERROR_BASE + 101)
+#define ERROR_WINHTTP_CANNOT_CALL_AFTER_SEND                (WINHTTP_ERROR_BASE + 102)
+#define ERROR_WINHTTP_CANNOT_CALL_AFTER_OPEN                (WINHTTP_ERROR_BASE + 103)
+#define ERROR_WINHTTP_HEADER_NOT_FOUND                      (WINHTTP_ERROR_BASE + 150)
+#define ERROR_WINHTTP_INVALID_SERVER_RESPONSE               (WINHTTP_ERROR_BASE + 152)
+#define ERROR_WINHTTP_INVALID_HEADER                        (WINHTTP_ERROR_BASE + 153)
+#define ERROR_WINHTTP_INVALID_QUERY_REQUEST                 (WINHTTP_ERROR_BASE + 154)
+#define ERROR_WINHTTP_HEADER_ALREADY_EXISTS                 (WINHTTP_ERROR_BASE + 155)
+#define ERROR_WINHTTP_REDIRECT_FAILED                       (WINHTTP_ERROR_BASE + 156)
+#define ERROR_WINHTTP_SECURE_CHANNEL_ERROR                  (WINHTTP_ERROR_BASE + 157)
+#define ERROR_WINHTTP_BAD_AUTO_PROXY_SCRIPT                 (WINHTTP_ERROR_BASE + 166)
+#define ERROR_WINHTTP_UNABLE_TO_DOWNLOAD_SCRIPT             (WINHTTP_ERROR_BASE + 167)
+#define ERROR_WINHTTP_SECURE_INVALID_CERT                   (WINHTTP_ERROR_BASE + 169)
+#define ERROR_WINHTTP_SECURE_CERT_REVOKED                   (WINHTTP_ERROR_BASE + 170)
+#define ERROR_WINHTTP_NOT_INITIALIZED                       (WINHTTP_ERROR_BASE + 172)
+#define ERROR_WINHTTP_SECURE_FAILURE                        (WINHTTP_ERROR_BASE + 175)
+#define ERROR_WINHTTP_AUTO_PROXY_SERVICE_ERROR              (WINHTTP_ERROR_BASE + 178)
+#define ERROR_WINHTTP_SECURE_CERT_WRONG_USAGE               (WINHTTP_ERROR_BASE + 179)
+#define ERROR_WINHTTP_AUTODETECTION_FAILED                  (WINHTTP_ERROR_BASE + 180)
+#define ERROR_WINHTTP_HEADER_COUNT_EXCEEDED                 (WINHTTP_ERROR_BASE + 181)
+#define ERROR_WINHTTP_HEADER_SIZE_OVERFLOW                  (WINHTTP_ERROR_BASE + 182)
+#define ERROR_WINHTTP_CHUNKED_ENCODING_HEADER_SIZE_OVERFLOW (WINHTTP_ERROR_BASE + 183)
+#define ERROR_WINHTTP_RESPONSE_DRAIN_OVERFLOW               (WINHTTP_ERROR_BASE + 184)
+#define ERROR_WINHTTP_CLIENT_CERT_NO_PRIVATE_KEY            (WINHTTP_ERROR_BASE + 185)
+#define ERROR_WINHTTP_CLIENT_CERT_NO_ACCESS_PRIVATE_KEY     (WINHTTP_ERROR_BASE + 186)
+#define WINHTTP_ERROR_LAST                                  (WINHTTP_ERROR_BASE + 186)
+
+/* WinHttp status codes */
+#define HTTP_STATUS_CONTINUE            100
+#define HTTP_STATUS_SWITCH_PROTOCOLS    101
+#define HTTP_STATUS_OK                  200
+#define HTTP_STATUS_CREATED             201
+#define HTTP_STATUS_ACCEPTED            202
+#define HTTP_STATUS_PARTIAL             203
+#define HTTP_STATUS_NO_CONTENT          204
+#define HTTP_STATUS_RESET_CONTENT       205
+#define HTTP_STATUS_PARTIAL_CONTENT     206
+#define HTTP_STATUS_WEBDAV_MULTI_STATUS 207
+#define HTTP_STATUS_AMBIGUOUS           300
+#define HTTP_STATUS_MOVED               301
+#define HTTP_STATUS_REDIRECT            302
+#define HTTP_STATUS_REDIRECT_METHOD     303
+#define HTTP_STATUS_NOT_MODIFIED        304
+#define HTTP_STATUS_USE_PROXY           305
+#define HTTP_STATUS_REDIRECT_KEEP_VERB  307
+#define HTTP_STATUS_BAD_REQUEST         400
+#define HTTP_STATUS_DENIED              401
+#define HTTP_STATUS_PAYMENT_REQ         402
+#define HTTP_STATUS_FORBIDDEN           403
+#define HTTP_STATUS_NOT_FOUND           404
+#define HTTP_STATUS_BAD_METHOD          405
+#define HTTP_STATUS_NONE_ACCEPTABLE     406
+#define HTTP_STATUS_PROXY_AUTH_REQ      407
+#define HTTP_STATUS_REQUEST_TIMEOUT     408
+#define HTTP_STATUS_CONFLICT            409
+#define HTTP_STATUS_GONE                410
+#define HTTP_STATUS_LENGTH_REQUIRED     411
+#define HTTP_STATUS_PRECOND_FAILED      412
+#define HTTP_STATUS_REQUEST_TOO_LARGE   413
+#define HTTP_STATUS_URI_TOO_LONG        414
+#define HTTP_STATUS_UNSUPPORTED_MEDIA   415
+#define HTTP_STATUS_RETRY_WITH          449
+#define HTTP_STATUS_SERVER_ERROR        500
+#define HTTP_STATUS_NOT_SUPPORTED       501
+#define HTTP_STATUS_BAD_GATEWAY         502
+#define HTTP_STATUS_SERVICE_UNAVAIL     503
+#define HTTP_STATUS_GATEWAY_TIMEOUT     504
+#define HTTP_STATUS_VERSION_NOT_SUP     505
+#define HTTP_STATUS_FIRST               HTTP_STATUS_CONTINUE
+#define HTTP_STATUS_LAST                HTTP_STATUS_VERSION_NOT_SUP
+
+#define SECURITY_FLAG_IGNORE_UNKNOWN_CA         0x00000100
+#define SECURITY_FLAG_IGNORE_CERT_DATE_INVALID  0x00002000
+#define SECURITY_FLAG_IGNORE_CERT_CN_INVALID    0x00001000
+#define SECURITY_FLAG_IGNORE_CERT_WRONG_USAGE   0x00000200
+#define SECURITY_FLAG_SECURE                    0x00000001
+#define SECURITY_FLAG_STRENGTH_WEAK             0x10000000
+#define SECURITY_FLAG_STRENGTH_MEDIUM           0x40000000
+#define SECURITY_FLAG_STRENGTH_STRONG           0x20000000
+
+#define ICU_NO_ENCODE          0x20000000
+#define ICU_DECODE             0x10000000
+#define ICU_NO_META            0x08000000
+#define ICU_ENCODE_SPACES_ONLY 0x04000000
+#define ICU_BROWSER_MODE       0x02000000
+#define ICU_ENCODE_PERCENT     0x00001000
+
+/* Query flags */
+#define WINHTTP_QUERY_MIME_VERSION                 0
+#define WINHTTP_QUERY_CONTENT_TYPE                 1
+#define WINHTTP_QUERY_CONTENT_TRANSFER_ENCODING    2
+#define WINHTTP_QUERY_CONTENT_ID                   3
+#define WINHTTP_QUERY_CONTENT_DESCRIPTION          4
+#define WINHTTP_QUERY_CONTENT_LENGTH               5
+#define WINHTTP_QUERY_CONTENT_LANGUAGE             6
+#define WINHTTP_QUERY_ALLOW                        7
+#define WINHTTP_QUERY_PUBLIC                       8
+#define WINHTTP_QUERY_DATE                         9
+#define WINHTTP_QUERY_EXPIRES                      10
+#define WINHTTP_QUERY_LAST_MODIFIED                11
+#define WINHTTP_QUERY_MESSAGE_ID                   12
+#define WINHTTP_QUERY_URI                          13
+#define WINHTTP_QUERY_DERIVED_FROM                 14
+#define WINHTTP_QUERY_COST                         15
+#define WINHTTP_QUERY_LINK                         16
+#define WINHTTP_QUERY_PRAGMA                       17
+#define WINHTTP_QUERY_VERSION                      18
+#define WINHTTP_QUERY_STATUS_CODE                  19
+#define WINHTTP_QUERY_STATUS_TEXT                  20
+#define WINHTTP_QUERY_RAW_HEADERS                  21
+#define WINHTTP_QUERY_RAW_HEADERS_CRLF             22
+#define WINHTTP_QUERY_CONNECTION                   23
+#define WINHTTP_QUERY_ACCEPT                       24
+#define WINHTTP_QUERY_ACCEPT_CHARSET               25
+#define WINHTTP_QUERY_ACCEPT_ENCODING              26
+#define WINHTTP_QUERY_ACCEPT_LANGUAGE              27
+#define WINHTTP_QUERY_AUTHORIZATION                28
+#define WINHTTP_QUERY_CONTENT_ENCODING             29
+#define WINHTTP_QUERY_FORWARDED                    30
+#define WINHTTP_QUERY_FROM                         31
+#define WINHTTP_QUERY_IF_MODIFIED_SINCE            32
+#define WINHTTP_QUERY_LOCATION                     33
+#define WINHTTP_QUERY_ORIG_URI                     34
+#define WINHTTP_QUERY_REFERER                      35
+#define WINHTTP_QUERY_RETRY_AFTER                  36
+#define WINHTTP_QUERY_SERVER                       37
+#define WINHTTP_QUERY_TITLE                        38
+#define WINHTTP_QUERY_USER_AGENT                   39
+#define WINHTTP_QUERY_WWW_AUTHENTICATE             40
+#define WINHTTP_QUERY_PROXY_AUTHENTICATE           41
+#define WINHTTP_QUERY_ACCEPT_RANGES                42
+#define WINHTTP_QUERY_SET_COOKIE                   43
+#define WINHTTP_QUERY_COOKIE                       44
+#define WINHTTP_QUERY_REQUEST_METHOD               45
+#define WINHTTP_QUERY_REFRESH                      46
+#define WINHTTP_QUERY_CONTENT_DISPOSITION          47
+#define WINHTTP_QUERY_AGE                          48
+#define WINHTTP_QUERY_CACHE_CONTROL                49
+#define WINHTTP_QUERY_CONTENT_BASE                 50
+#define WINHTTP_QUERY_CONTENT_LOCATION             51
+#define WINHTTP_QUERY_CONTENT_MD5                  52
+#define WINHTTP_QUERY_CONTENT_RANGE                53
+#define WINHTTP_QUERY_ETAG                         54
+#define WINHTTP_QUERY_HOST                         55
+#define WINHTTP_QUERY_IF_MATCH                     56
+#define WINHTTP_QUERY_IF_NONE_MATCH                57
+#define WINHTTP_QUERY_IF_RANGE                     58
+#define WINHTTP_QUERY_IF_UNMODIFIED_SINCE          59
+#define WINHTTP_QUERY_MAX_FORWARDS                 60
+#define WINHTTP_QUERY_PROXY_AUTHORIZATION          61
+#define WINHTTP_QUERY_RANGE                        62
+#define WINHTTP_QUERY_TRANSFER_ENCODING            63
+#define WINHTTP_QUERY_UPGRADE                      64
+#define WINHTTP_QUERY_VARY                         65
+#define WINHTTP_QUERY_VIA                          66
+#define WINHTTP_QUERY_WARNING                      67
+#define WINHTTP_QUERY_EXPECT                       68
+#define WINHTTP_QUERY_PROXY_CONNECTION             69
+#define WINHTTP_QUERY_UNLESS_MODIFIED_SINCE        70
+#define WINHTTP_QUERY_PROXY_SUPPORT                75
+#define WINHTTP_QUERY_AUTHENTICATION_INFO          76
+#define WINHTTP_QUERY_PASSPORT_URLS                77
+#define WINHTTP_QUERY_PASSPORT_CONFIG              78
+#define WINHTTP_QUERY_MAX                          78
+#define WINHTTP_QUERY_CUSTOM                       65535
+#define WINHTTP_QUERY_FLAG_REQUEST_HEADERS         0x80000000
+#define WINHTTP_QUERY_FLAG_SYSTEMTIME              0x40000000
+#define WINHTTP_QUERY_FLAG_NUMBER                  0x20000000
+
+/* Callback options */
+#define WINHTTP_CALLBACK_STATUS_RESOLVING_NAME          0x00000001
+#define WINHTTP_CALLBACK_STATUS_NAME_RESOLVED           0x00000002
+#define WINHTTP_CALLBACK_STATUS_CONNECTING_TO_SERVER    0x00000004
+#define WINHTTP_CALLBACK_STATUS_CONNECTED_TO_SERVER     0x00000008
+#define WINHTTP_CALLBACK_STATUS_SENDING_REQUEST         0x00000010
+#define WINHTTP_CALLBACK_STATUS_REQUEST_SENT            0x00000020
+#define WINHTTP_CALLBACK_STATUS_RECEIVING_RESPONSE      0x00000040
+#define WINHTTP_CALLBACK_STATUS_RESPONSE_RECEIVED       0x00000080
+#define WINHTTP_CALLBACK_STATUS_CLOSING_CONNECTION      0x00000100
+#define WINHTTP_CALLBACK_STATUS_CONNECTION_CLOSED       0x00000200
+#define WINHTTP_CALLBACK_STATUS_HANDLE_CREATED          0x00000400
+#define WINHTTP_CALLBACK_STATUS_HANDLE_CLOSING          0x00000800
+#define WINHTTP_CALLBACK_STATUS_DETECTING_PROXY         0x00001000
+#define WINHTTP_CALLBACK_STATUS_REDIRECT                0x00004000
+#define WINHTTP_CALLBACK_STATUS_INTERMEDIATE_RESPONSE   0x00008000
+#define WINHTTP_CALLBACK_STATUS_SECURE_FAILURE          0x00010000
+#define WINHTTP_CALLBACK_STATUS_HEADERS_AVAILABLE       0x00020000
+#define WINHTTP_CALLBACK_STATUS_DATA_AVAILABLE          0x00040000
+#define WINHTTP_CALLBACK_STATUS_READ_COMPLETE           0x00080000
+#define WINHTTP_CALLBACK_STATUS_WRITE_COMPLETE          0x00100000
+#define WINHTTP_CALLBACK_STATUS_REQUEST_ERROR           0x00200000
+#define WINHTTP_CALLBACK_STATUS_SENDREQUEST_COMPLETE    0x00400000
+#define WINHTTP_CALLBACK_FLAG_RESOLVE_NAME              (WINHTTP_CALLBACK_STATUS_RESOLVING_NAME | WINHTTP_CALLBACK_STATUS_NAME_RESOLVED)
+#define WINHTTP_CALLBACK_FLAG_CONNECT_TO_SERVER         (WINHTTP_CALLBACK_STATUS_CONNECTING_TO_SERVER | WINHTTP_CALLBACK_STATUS_CONNECTED_TO_SERVER)
+#define WINHTTP_CALLBACK_FLAG_SEND_REQUEST              (WINHTTP_CALLBACK_STATUS_SENDING_REQUEST | WINHTTP_CALLBACK_STATUS_REQUEST_SENT)
+#define WINHTTP_CALLBACK_FLAG_RECEIVE_RESPONSE          (WINHTTP_CALLBACK_STATUS_RECEIVING_RESPONSE | WINHTTP_CALLBACK_STATUS_RESPONSE_RECEIVED)
+#define WINHTTP_CALLBACK_FLAG_CLOSE_CONNECTION          (WINHTTP_CALLBACK_STATUS_CLOSING_CONNECTION | WINHTTP_CALLBACK_STATUS_CONNECTION_CLOSED)
+#define WINHTTP_CALLBACK_FLAG_HANDLES                   (WINHTTP_CALLBACK_STATUS_HANDLE_CREATED | WINHTTP_CALLBACK_STATUS_HANDLE_CLOSING)
+#define WINHTTP_CALLBACK_FLAG_DETECTING_PROXY           WINHTTP_CALLBACK_STATUS_DETECTING_PROXY
+#define WINHTTP_CALLBACK_FLAG_REDIRECT                  WINHTTP_CALLBACK_STATUS_REDIRECT
+#define WINHTTP_CALLBACK_FLAG_INTERMEDIATE_RESPONSE     WINHTTP_CALLBACK_STATUS_INTERMEDIATE_RESPONSE
+#define WINHTTP_CALLBACK_FLAG_SECURE_FAILURE            WINHTTP_CALLBACK_STATUS_SECURE_FAILURE
+#define WINHTTP_CALLBACK_FLAG_SENDREQUEST_COMPLETE      WINHTTP_CALLBACK_STATUS_SENDREQUEST_COMPLETE
+#define WINHTTP_CALLBACK_FLAG_HEADERS_AVAILABLE         WINHTTP_CALLBACK_STATUS_HEADERS_AVAILABLE
+#define WINHTTP_CALLBACK_FLAG_DATA_AVAILABLE            WINHTTP_CALLBACK_STATUS_DATA_AVAILABLE
+#define WINHTTP_CALLBACK_FLAG_READ_COMPLETE             WINHTTP_CALLBACK_STATUS_READ_COMPLETE
+#define WINHTTP_CALLBACK_FLAG_WRITE_COMPLETE            WINHTTP_CALLBACK_STATUS_WRITE_COMPLETE
+#define WINHTTP_CALLBACK_FLAG_REQUEST_ERROR             WINHTTP_CALLBACK_STATUS_REQUEST_ERROR
+#define WINHTTP_CALLBACK_FLAG_ALL_COMPLETIONS           (WINHTTP_CALLBACK_STATUS_SENDREQUEST_COMPLETE | WINHTTP_CALLBACK_STATUS_HEADERS_AVAILABLE \
+                                                        | WINHTTP_CALLBACK_STATUS_DATA_AVAILABLE | WINHTTP_CALLBACK_STATUS_READ_COMPLETE          \
+                                                        | WINHTTP_CALLBACK_STATUS_WRITE_COMPLETE | WINHTTP_CALLBACK_STATUS_REQUEST_ERROR)
+#define WINHTTP_CALLBACK_FLAG_ALL_NOTIFICATIONS         0xffffffff
+#define WINHTTP_INVALID_STATUS_CALLBACK                 ((WINHTTP_STATUS_CALLBACK)(-1))
+
+#define API_RECEIVE_RESPONSE          (1)
+#define API_QUERY_DATA_AVAILABLE      (2)
+#define API_READ_DATA                 (3)
+#define API_WRITE_DATA                (4)
+#define API_SEND_REQUEST              (5)
+
+#define WINHTTP_HANDLE_TYPE_SESSION                  1
+#define WINHTTP_HANDLE_TYPE_CONNECT                  2
+#define WINHTTP_HANDLE_TYPE_REQUEST                  3
+
+#define WINHTTP_CALLBACK_STATUS_FLAG_CERT_REV_FAILED         0x00000001
+#define WINHTTP_CALLBACK_STATUS_FLAG_INVALID_CERT            0x00000002
+#define WINHTTP_CALLBACK_STATUS_FLAG_CERT_REVOKED            0x00000004
+#define WINHTTP_CALLBACK_STATUS_FLAG_INVALID_CA              0x00000008
+#define WINHTTP_CALLBACK_STATUS_FLAG_CERT_CN_INVALID         0x00000010
+#define WINHTTP_CALLBACK_STATUS_FLAG_CERT_DATE_INVALID       0x00000020
+#define WINHTTP_CALLBACK_STATUS_FLAG_CERT_WRONG_USAGE        0x00000040
+#define WINHTTP_CALLBACK_STATUS_FLAG_SECURITY_CHANNEL_ERROR  0x80000000
+
+#define WINHTTP_FLAG_SECURE_PROTOCOL_SSL2    0x00000008
+#define WINHTTP_FLAG_SECURE_PROTOCOL_SSL3    0x00000020
+#define WINHTTP_FLAG_SECURE_PROTOCOL_TLS1    0x00000080
+#define WINHTTP_FLAG_SECURE_PROTOCOL_TLS1_1  0x00000200
+#define WINHTTP_FLAG_SECURE_PROTOCOL_TLS1_2  0x00000800
+#define WINHTTP_FLAG_SECURE_PROTOCOL_ALL     (WINHTTP_FLAG_SECURE_PROTOCOL_SSL2 | WINHTTP_FLAG_SECURE_PROTOCOL_SSL3 | WINHTTP_FLAG_SECURE_PROTOCOL_TLS1)
+
+#define WINHTTP_AUTH_SCHEME_BASIC      0x00000001
+#define WINHTTP_AUTH_SCHEME_NTLM       0x00000002
+#define WINHTTP_AUTH_SCHEME_PASSPORT   0x00000004
+#define WINHTTP_AUTH_SCHEME_DIGEST     0x00000008
+#define WINHTTP_AUTH_SCHEME_NEGOTIATE  0x00000010
+
+#define WINHTTP_AUTH_TARGET_SERVER     0x00000000
+#define WINHTTP_AUTH_TARGET_PROXY      0x00000001
+
+#define WINHTTP_TIME_FORMAT_BUFSIZE    62
+
+typedef struct
+{
+    DWORD   dwStructSize;
+    LPWSTR  lpszScheme;
+    DWORD   dwSchemeLength;
+    INTERNET_SCHEME nScheme;
+    LPWSTR  lpszHostName;
+    DWORD   dwHostNameLength;
+    INTERNET_PORT nPort;
+    LPWSTR  lpszUserName;
+    DWORD   dwUserNameLength;
+    LPWSTR  lpszPassword;
+    DWORD   dwPasswordLength;
+    LPWSTR  lpszUrlPath;
+    DWORD   dwUrlPathLength;
+    LPWSTR  lpszExtraInfo;
+    DWORD   dwExtraInfoLength;
+} URL_COMPONENTS, *LPURL_COMPONENTS;
+typedef URL_COMPONENTS URL_COMPONENTSW;
+typedef LPURL_COMPONENTS LPURL_COMPONENTSW;
+
+typedef struct
+{
+    DWORD_PTR dwResult;
+    DWORD dwError;
+} WINHTTP_ASYNC_RESULT, *LPWINHTTP_ASYNC_RESULT;
+
+typedef struct
+{
+    FILETIME ftExpiry;
+    FILETIME ftStart;
+    LPWSTR lpszSubjectInfo;
+    LPWSTR lpszIssuerInfo;
+    LPWSTR lpszProtocolName;
+    LPWSTR lpszSignatureAlgName;
+    LPWSTR lpszEncryptionAlgName;
+    DWORD dwKeySize;
+} WINHTTP_CERTIFICATE_INFO;
+
+typedef struct
+{
+    DWORD dwAccessType;
+    LPWSTR lpszProxy;
+    LPWSTR lpszProxyBypass;
+} WINHTTP_PROXY_INFO, *LPWINHTTP_PROXY_INFO;
+typedef WINHTTP_PROXY_INFO WINHTTP_PROXY_INFOW;
+typedef LPWINHTTP_PROXY_INFO LPWINHTTP_PROXY_INFOW;
+
+typedef struct
+{
+    BOOL   fAutoDetect;
+    LPWSTR lpszAutoConfigUrl;
+    LPWSTR lpszProxy;
+    LPWSTR lpszProxyBypass;
+} WINHTTP_CURRENT_USER_IE_PROXY_CONFIG;
+
+typedef VOID (CALLBACK *WINHTTP_STATUS_CALLBACK)(HINTERNET,DWORD_PTR,DWORD,LPVOID,DWORD);
+
+#define WINHTTP_AUTO_DETECT_TYPE_DHCP   0x00000001
+#define WINHTTP_AUTO_DETECT_TYPE_DNS_A  0x00000002
+
+#define WINHTTP_AUTOPROXY_AUTO_DETECT           0x00000001
+#define WINHTTP_AUTOPROXY_CONFIG_URL            0x00000002
+#define WINHTTP_AUTOPROXY_RUN_INPROCESS         0x00010000
+#define WINHTTP_AUTOPROXY_RUN_OUTPROCESS_ONLY   0x00020000
+
+typedef struct
+{
+    DWORD dwFlags;
+    DWORD dwAutoDetectFlags;
+    LPCWSTR lpszAutoConfigUrl;
+    LPVOID lpvReserved;
+    DWORD dwReserved;
+    BOOL fAutoLogonIfChallenged;
+} WINHTTP_AUTOPROXY_OPTIONS;
+
+typedef struct
+{
+    DWORD dwMajorVersion;
+    DWORD dwMinorVersion;
+} HTTP_VERSION_INFO, *LPHTTP_VERSION_INFO;
+
+#ifdef _WS2DEF_
+typedef struct
+{
+    DWORD cbSize;
+    SOCKADDR_STORAGE LocalAddress;
+    SOCKADDR_STORAGE RemoteAddress;
+} WINHTTP_CONNECTION_INFO;
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+BOOL        WINAPI WinHttpAddRequestHeaders(HINTERNET,LPCWSTR,DWORD,DWORD);
+BOOL        WINAPI WinHttpDetectAutoProxyConfigUrl(DWORD,LPWSTR*);
+BOOL        WINAPI WinHttpCheckPlatform(void);
+BOOL        WINAPI WinHttpCloseHandle(HINTERNET);
+HINTERNET   WINAPI WinHttpConnect(HINTERNET,LPCWSTR,INTERNET_PORT,DWORD);
+BOOL        WINAPI WinHttpCrackUrl(LPCWSTR,DWORD,DWORD,LPURL_COMPONENTS);
+BOOL        WINAPI WinHttpCreateUrl(LPURL_COMPONENTS,DWORD,LPWSTR,LPDWORD);
+BOOL        WINAPI WinHttpGetDefaultProxyConfiguration(WINHTTP_PROXY_INFO*);
+BOOL        WINAPI WinHttpGetIEProxyConfigForCurrentUser(WINHTTP_CURRENT_USER_IE_PROXY_CONFIG*);
+BOOL        WINAPI WinHttpGetProxyForUrl(HINTERNET,LPCWSTR,WINHTTP_AUTOPROXY_OPTIONS*,WINHTTP_PROXY_INFO*);
+HINTERNET   WINAPI WinHttpOpen(LPCWSTR,DWORD,LPCWSTR,LPCWSTR,DWORD);
+HINTERNET   WINAPI WinHttpOpenRequest(HINTERNET,LPCWSTR,LPCWSTR,LPCWSTR,LPCWSTR,LPCWSTR*,DWORD);
+BOOL        WINAPI WinHttpQueryAuthParams(HINTERNET,DWORD,LPVOID*);
+BOOL        WINAPI WinHttpQueryAuthSchemes(HINTERNET,LPDWORD,LPDWORD,LPDWORD);
+BOOL        WINAPI WinHttpQueryDataAvailable(HINTERNET,LPDWORD);
+BOOL        WINAPI WinHttpQueryHeaders(HINTERNET,DWORD,LPCWSTR,LPVOID,LPDWORD,LPDWORD);
+BOOL        WINAPI WinHttpQueryOption(HINTERNET,DWORD,LPVOID,LPDWORD);
+BOOL        WINAPI WinHttpReadData(HINTERNET,LPVOID,DWORD,LPDWORD);
+BOOL        WINAPI WinHttpReceiveResponse(HINTERNET,LPVOID);
+BOOL        WINAPI WinHttpSendRequest(HINTERNET,LPCWSTR,DWORD,LPVOID,DWORD,DWORD,DWORD_PTR);
+BOOL        WINAPI WinHttpSetDefaultProxyConfiguration(WINHTTP_PROXY_INFO*);
+BOOL        WINAPI WinHttpSetCredentials(HINTERNET,DWORD,DWORD,LPCWSTR,LPCWSTR,LPVOID);
+BOOL        WINAPI WinHttpSetOption(HINTERNET,DWORD,LPVOID,DWORD);
+WINHTTP_STATUS_CALLBACK WINAPI WinHttpSetStatusCallback(HINTERNET,WINHTTP_STATUS_CALLBACK,DWORD,DWORD_PTR);
+BOOL        WINAPI WinHttpSetTimeouts(HINTERNET,int,int,int,int);
+BOOL        WINAPI WinHttpTimeFromSystemTime(const SYSTEMTIME *,LPWSTR);
+BOOL        WINAPI WinHttpTimeToSystemTime(LPCWSTR,SYSTEMTIME*);
+BOOL        WINAPI WinHttpWriteData(HINTERNET,LPCVOID,DWORD,LPDWORD);
+
+#ifdef __cplusplus
+}
+#endif
+
+#include <poppack.h>
+
+#endif  /* __WINE_WINHTTP_H */
+
+#else
+
+#include_next <winhttp.h>
+
+#endif

vendor/libgit2-sys/libgit2/deps/winhttp/winhttp64.def

diff --git a/vendor/libgit2-sys/libgit2/deps/winhttp/winhttp64.def b/vendor/libgit2-sys/libgit2/deps/winhttp/winhttp64.def
new file mode 100644
index 0000000..bfad3a0
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/winhttp/winhttp64.def
@@ -0,0 +1,29 @@
+LIBRARY		WINHTTP
+EXPORTS
+WinHttpAddRequestHeaders
+WinHttpCheckPlatform
+WinHttpCloseHandle
+WinHttpConnect
+WinHttpCrackUrl
+WinHttpCreateUrl
+WinHttpDetectAutoProxyConfigUrl
+WinHttpGetDefaultProxyConfiguration
+WinHttpGetIEProxyConfigForCurrentUser
+WinHttpGetProxyForUrl
+WinHttpOpen
+WinHttpOpenRequest
+WinHttpQueryAuthSchemes
+WinHttpQueryDataAvailable
+WinHttpQueryHeaders
+WinHttpQueryOption
+WinHttpReadData
+WinHttpReceiveResponse
+WinHttpSendRequest
+WinHttpSetCredentials
+WinHttpSetDefaultProxyConfiguration
+WinHttpSetOption
+WinHttpSetStatusCallback
+WinHttpSetTimeouts
+WinHttpTimeFromSystemTime
+WinHttpTimeToSystemTime
+WinHttpWriteData

vendor/libgit2-sys/libgit2/deps/zlib/CMakeLists.txt

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/CMakeLists.txt b/vendor/libgit2-sys/libgit2/deps/zlib/CMakeLists.txt
new file mode 100644
index 0000000..b0cb7f7
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/CMakeLists.txt
@@ -0,0 +1,4 @@
+ADD_DEFINITIONS(-DNO_VIZ -DSTDC -DNO_GZIP)
+FILE(GLOB SRC_ZLIB "*.c" "*.h")
+INCLUDE_DIRECTORIES(".")
+ADD_LIBRARY(zlib OBJECT ${SRC_ZLIB})

vendor/libgit2-sys/libgit2/deps/zlib/adler32.c

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/adler32.c b/vendor/libgit2-sys/libgit2/deps/zlib/adler32.c
new file mode 100644
index 0000000..d0be438
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/adler32.c
@@ -0,0 +1,186 @@
+/* adler32.c -- compute the Adler-32 checksum of a data stream
+ * Copyright (C) 1995-2011, 2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* @(#) $Id$ */
+
+#include "zutil.h"
+
+local uLong adler32_combine_ OF((uLong adler1, uLong adler2, z_off64_t len2));
+
+#define BASE 65521U     /* largest prime smaller than 65536 */
+#define NMAX 5552
+/* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
+
+#define DO1(buf,i)  {adler += (buf)[i]; sum2 += adler;}
+#define DO2(buf,i)  DO1(buf,i); DO1(buf,i+1);
+#define DO4(buf,i)  DO2(buf,i); DO2(buf,i+2);
+#define DO8(buf,i)  DO4(buf,i); DO4(buf,i+4);
+#define DO16(buf)   DO8(buf,0); DO8(buf,8);
+
+/* use NO_DIVIDE if your processor does not do division in hardware --
+   try it both ways to see which is faster */
+#ifdef NO_DIVIDE
+/* note that this assumes BASE is 65521, where 65536 % 65521 == 15
+   (thank you to John Reiser for pointing this out) */
+#  define CHOP(a) \
+    do { \
+        unsigned long tmp = a >> 16; \
+        a &= 0xffffUL; \
+        a += (tmp << 4) - tmp; \
+    } while (0)
+#  define MOD28(a) \
+    do { \
+        CHOP(a); \
+        if (a >= BASE) a -= BASE; \
+    } while (0)
+#  define MOD(a) \
+    do { \
+        CHOP(a); \
+        MOD28(a); \
+    } while (0)
+#  define MOD63(a) \
+    do { /* this assumes a is not negative */ \
+        z_off64_t tmp = a >> 32; \
+        a &= 0xffffffffL; \
+        a += (tmp << 8) - (tmp << 5) + tmp; \
+        tmp = a >> 16; \
+        a &= 0xffffL; \
+        a += (tmp << 4) - tmp; \
+        tmp = a >> 16; \
+        a &= 0xffffL; \
+        a += (tmp << 4) - tmp; \
+        if (a >= BASE) a -= BASE; \
+    } while (0)
+#else
+#  define MOD(a) a %= BASE
+#  define MOD28(a) a %= BASE
+#  define MOD63(a) a %= BASE
+#endif
+
+/* ========================================================================= */
+uLong ZEXPORT adler32_z(adler, buf, len)
+    uLong adler;
+    const Bytef *buf;
+    z_size_t len;
+{
+    unsigned long sum2;
+    unsigned n;
+
+    /* split Adler-32 into component sums */
+    sum2 = (adler >> 16) & 0xffff;
+    adler &= 0xffff;
+
+    /* in case user likes doing a byte at a time, keep it fast */
+    if (len == 1) {
+        adler += buf[0];
+        if (adler >= BASE)
+            adler -= BASE;
+        sum2 += adler;
+        if (sum2 >= BASE)
+            sum2 -= BASE;
+        return adler | (sum2 << 16);
+    }
+
+    /* initial Adler-32 value (deferred check for len == 1 speed) */
+    if (buf == Z_NULL)
+        return 1L;
+
+    /* in case short lengths are provided, keep it somewhat fast */
+    if (len < 16) {
+        while (len--) {
+            adler += *buf++;
+            sum2 += adler;
+        }
+        if (adler >= BASE)
+            adler -= BASE;
+        MOD28(sum2);            /* only added so many BASE's */
+        return adler | (sum2 << 16);
+    }
+
+    /* do length NMAX blocks -- requires just one modulo operation */
+    while (len >= NMAX) {
+        len -= NMAX;
+        n = NMAX / 16;          /* NMAX is divisible by 16 */
+        do {
+            DO16(buf);          /* 16 sums unrolled */
+            buf += 16;
+        } while (--n);
+        MOD(adler);
+        MOD(sum2);
+    }
+
+    /* do remaining bytes (less than NMAX, still just one modulo) */
+    if (len) {                  /* avoid modulos if none remaining */
+        while (len >= 16) {
+            len -= 16;
+            DO16(buf);
+            buf += 16;
+        }
+        while (len--) {
+            adler += *buf++;
+            sum2 += adler;
+        }
+        MOD(adler);
+        MOD(sum2);
+    }
+
+    /* return recombined sums */
+    return adler | (sum2 << 16);
+}
+
+/* ========================================================================= */
+uLong ZEXPORT adler32(adler, buf, len)
+    uLong adler;
+    const Bytef *buf;
+    uInt len;
+{
+    return adler32_z(adler, buf, len);
+}
+
+/* ========================================================================= */
+local uLong adler32_combine_(adler1, adler2, len2)
+    uLong adler1;
+    uLong adler2;
+    z_off64_t len2;
+{
+    unsigned long sum1;
+    unsigned long sum2;
+    unsigned rem;
+
+    /* for negative len, return invalid adler32 as a clue for debugging */
+    if (len2 < 0)
+        return 0xffffffffUL;
+
+    /* the derivation of this formula is left as an exercise for the reader */
+    MOD63(len2);                /* assumes len2 >= 0 */
+    rem = (unsigned)len2;
+    sum1 = adler1 & 0xffff;
+    sum2 = rem * sum1;
+    MOD(sum2);
+    sum1 += (adler2 & 0xffff) + BASE - 1;
+    sum2 += ((adler1 >> 16) & 0xffff) + ((adler2 >> 16) & 0xffff) + BASE - rem;
+    if (sum1 >= BASE) sum1 -= BASE;
+    if (sum1 >= BASE) sum1 -= BASE;
+    if (sum2 >= ((unsigned long)BASE << 1)) sum2 -= ((unsigned long)BASE << 1);
+    if (sum2 >= BASE) sum2 -= BASE;
+    return sum1 | (sum2 << 16);
+}
+
+/* ========================================================================= */
+uLong ZEXPORT adler32_combine(adler1, adler2, len2)
+    uLong adler1;
+    uLong adler2;
+    z_off_t len2;
+{
+    return adler32_combine_(adler1, adler2, len2);
+}
+
+uLong ZEXPORT adler32_combine64(adler1, adler2, len2)
+    uLong adler1;
+    uLong adler2;
+    z_off64_t len2;
+{
+    return adler32_combine_(adler1, adler2, len2);
+}

vendor/libgit2-sys/libgit2/deps/zlib/crc32.c

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/crc32.c b/vendor/libgit2-sys/libgit2/deps/zlib/crc32.c
new file mode 100644
index 0000000..9580440
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/crc32.c
@@ -0,0 +1,442 @@
+/* crc32.c -- compute the CRC-32 of a data stream
+ * Copyright (C) 1995-2006, 2010, 2011, 2012, 2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ *
+ * Thanks to Rodney Brown <rbrown64@csc.com.au> for his contribution of faster
+ * CRC methods: exclusive-oring 32 bits of data at a time, and pre-computing
+ * tables for updating the shift register in one step with three exclusive-ors
+ * instead of four steps with four exclusive-ors.  This results in about a
+ * factor of two increase in speed on a Power PC G4 (PPC7455) using gcc -O3.
+ */
+
+/* @(#) $Id$ */
+
+/*
+  Note on the use of DYNAMIC_CRC_TABLE: there is no mutex or semaphore
+  protection on the static variables used to control the first-use generation
+  of the crc tables.  Therefore, if you #define DYNAMIC_CRC_TABLE, you should
+  first call get_crc_table() to initialize the tables before allowing more than
+  one thread to use crc32().
+
+  DYNAMIC_CRC_TABLE and MAKECRCH can be #defined to write out crc32.h.
+ */
+
+#ifdef MAKECRCH
+#  include <stdio.h>
+#  ifndef DYNAMIC_CRC_TABLE
+#    define DYNAMIC_CRC_TABLE
+#  endif /* !DYNAMIC_CRC_TABLE */
+#endif /* MAKECRCH */
+
+#include "zutil.h"      /* for STDC and FAR definitions */
+
+/* Definitions for doing the crc four data bytes at a time. */
+#if !defined(NOBYFOUR) && defined(Z_U4)
+#  define BYFOUR
+#endif
+#ifdef BYFOUR
+   local unsigned long crc32_little OF((unsigned long,
+                        const unsigned char FAR *, z_size_t));
+   local unsigned long crc32_big OF((unsigned long,
+                        const unsigned char FAR *, z_size_t));
+#  define TBLS 8
+#else
+#  define TBLS 1
+#endif /* BYFOUR */
+
+/* Local functions for crc concatenation */
+local unsigned long gf2_matrix_times OF((unsigned long *mat,
+                                         unsigned long vec));
+local void gf2_matrix_square OF((unsigned long *square, unsigned long *mat));
+local uLong crc32_combine_ OF((uLong crc1, uLong crc2, z_off64_t len2));
+
+
+#ifdef DYNAMIC_CRC_TABLE
+
+local volatile int crc_table_empty = 1;
+local z_crc_t FAR crc_table[TBLS][256];
+local void make_crc_table OF((void));
+#ifdef MAKECRCH
+   local void write_table OF((FILE *, const z_crc_t FAR *));
+#endif /* MAKECRCH */
+/*
+  Generate tables for a byte-wise 32-bit CRC calculation on the polynomial:
+  x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x+1.
+
+  Polynomials over GF(2) are represented in binary, one bit per coefficient,
+  with the lowest powers in the most significant bit.  Then adding polynomials
+  is just exclusive-or, and multiplying a polynomial by x is a right shift by
+  one.  If we call the above polynomial p, and represent a byte as the
+  polynomial q, also with the lowest power in the most significant bit (so the
+  byte 0xb1 is the polynomial x^7+x^3+x+1), then the CRC is (q*x^32) mod p,
+  where a mod b means the remainder after dividing a by b.
+
+  This calculation is done using the shift-register method of multiplying and
+  taking the remainder.  The register is initialized to zero, and for each
+  incoming bit, x^32 is added mod p to the register if the bit is a one (where
+  x^32 mod p is p+x^32 = x^26+...+1), and the register is multiplied mod p by
+  x (which is shifting right by one and adding x^32 mod p if the bit shifted
+  out is a one).  We start with the highest power (least significant bit) of
+  q and repeat for all eight bits of q.
+
+  The first table is simply the CRC of all possible eight bit values.  This is
+  all the information needed to generate CRCs on data a byte at a time for all
+  combinations of CRC register values and incoming bytes.  The remaining tables
+  allow for word-at-a-time CRC calculation for both big-endian and little-
+  endian machines, where a word is four bytes.
+*/
+local void make_crc_table()
+{
+    z_crc_t c;
+    int n, k;
+    z_crc_t poly;                       /* polynomial exclusive-or pattern */
+    /* terms of polynomial defining this crc (except x^32): */
+    static volatile int first = 1;      /* flag to limit concurrent making */
+    static const unsigned char p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26};
+
+    /* See if another task is already doing this (not thread-safe, but better
+       than nothing -- significantly reduces duration of vulnerability in
+       case the advice about DYNAMIC_CRC_TABLE is ignored) */
+    if (first) {
+        first = 0;
+
+        /* make exclusive-or pattern from polynomial (0xedb88320UL) */
+        poly = 0;
+        for (n = 0; n < (int)(sizeof(p)/sizeof(unsigned char)); n++)
+            poly |= (z_crc_t)1 << (31 - p[n]);
+
+        /* generate a crc for every 8-bit value */
+        for (n = 0; n < 256; n++) {
+            c = (z_crc_t)n;
+            for (k = 0; k < 8; k++)
+                c = c & 1 ? poly ^ (c >> 1) : c >> 1;
+            crc_table[0][n] = c;
+        }
+
+#ifdef BYFOUR
+        /* generate crc for each value followed by one, two, and three zeros,
+           and then the byte reversal of those as well as the first table */
+        for (n = 0; n < 256; n++) {
+            c = crc_table[0][n];
+            crc_table[4][n] = ZSWAP32(c);
+            for (k = 1; k < 4; k++) {
+                c = crc_table[0][c & 0xff] ^ (c >> 8);
+                crc_table[k][n] = c;
+                crc_table[k + 4][n] = ZSWAP32(c);
+            }
+        }
+#endif /* BYFOUR */
+
+        crc_table_empty = 0;
+    }
+    else {      /* not first */
+        /* wait for the other guy to finish (not efficient, but rare) */
+        while (crc_table_empty)
+            ;
+    }
+
+#ifdef MAKECRCH
+    /* write out CRC tables to crc32.h */
+    {
+        FILE *out;
+
+        out = fopen("crc32.h", "w");
+        if (out == NULL) return;
+        fprintf(out, "/* crc32.h -- tables for rapid CRC calculation\n");
+        fprintf(out, " * Generated automatically by crc32.c\n */\n\n");
+        fprintf(out, "local const z_crc_t FAR ");
+        fprintf(out, "crc_table[TBLS][256] =\n{\n  {\n");
+        write_table(out, crc_table[0]);
+#  ifdef BYFOUR
+        fprintf(out, "#ifdef BYFOUR\n");
+        for (k = 1; k < 8; k++) {
+            fprintf(out, "  },\n  {\n");
+            write_table(out, crc_table[k]);
+        }
+        fprintf(out, "#endif\n");
+#  endif /* BYFOUR */
+        fprintf(out, "  }\n};\n");
+        fclose(out);
+    }
+#endif /* MAKECRCH */
+}
+
+#ifdef MAKECRCH
+local void write_table(out, table)
+    FILE *out;
+    const z_crc_t FAR *table;
+{
+    int n;
+
+    for (n = 0; n < 256; n++)
+        fprintf(out, "%s0x%08lxUL%s", n % 5 ? "" : "    ",
+                (unsigned long)(table[n]),
+                n == 255 ? "\n" : (n % 5 == 4 ? ",\n" : ", "));
+}
+#endif /* MAKECRCH */
+
+#else /* !DYNAMIC_CRC_TABLE */
+/* ========================================================================
+ * Tables of CRC-32s of all single-byte values, made by make_crc_table().
+ */
+#include "crc32.h"
+#endif /* DYNAMIC_CRC_TABLE */
+
+/* =========================================================================
+ * This function can be used by asm versions of crc32()
+ */
+const z_crc_t FAR * ZEXPORT get_crc_table()
+{
+#ifdef DYNAMIC_CRC_TABLE
+    if (crc_table_empty)
+        make_crc_table();
+#endif /* DYNAMIC_CRC_TABLE */
+    return (const z_crc_t FAR *)crc_table;
+}
+
+/* ========================================================================= */
+#define DO1 crc = crc_table[0][((int)crc ^ (*buf++)) & 0xff] ^ (crc >> 8)
+#define DO8 DO1; DO1; DO1; DO1; DO1; DO1; DO1; DO1
+
+/* ========================================================================= */
+unsigned long ZEXPORT crc32_z(crc, buf, len)
+    unsigned long crc;
+    const unsigned char FAR *buf;
+    z_size_t len;
+{
+    if (buf == Z_NULL) return 0UL;
+
+#ifdef DYNAMIC_CRC_TABLE
+    if (crc_table_empty)
+        make_crc_table();
+#endif /* DYNAMIC_CRC_TABLE */
+
+#ifdef BYFOUR
+    if (sizeof(void *) == sizeof(ptrdiff_t)) {
+        z_crc_t endian;
+
+        endian = 1;
+        if (*((unsigned char *)(&endian)))
+            return crc32_little(crc, buf, len);
+        else
+            return crc32_big(crc, buf, len);
+    }
+#endif /* BYFOUR */
+    crc = crc ^ 0xffffffffUL;
+    while (len >= 8) {
+        DO8;
+        len -= 8;
+    }
+    if (len) do {
+        DO1;
+    } while (--len);
+    return crc ^ 0xffffffffUL;
+}
+
+/* ========================================================================= */
+unsigned long ZEXPORT crc32(crc, buf, len)
+    unsigned long crc;
+    const unsigned char FAR *buf;
+    uInt len;
+{
+    return crc32_z(crc, buf, len);
+}
+
+#ifdef BYFOUR
+
+/*
+   This BYFOUR code accesses the passed unsigned char * buffer with a 32-bit
+   integer pointer type. This violates the strict aliasing rule, where a
+   compiler can assume, for optimization purposes, that two pointers to
+   fundamentally different types won't ever point to the same memory. This can
+   manifest as a problem only if one of the pointers is written to. This code
+   only reads from those pointers. So long as this code remains isolated in
+   this compilation unit, there won't be a problem. For this reason, this code
+   should not be copied and pasted into a compilation unit in which other code
+   writes to the buffer that is passed to these routines.
+ */
+
+/* ========================================================================= */
+#define DOLIT4 c ^= *buf4++; \
+        c = crc_table[3][c & 0xff] ^ crc_table[2][(c >> 8) & 0xff] ^ \
+            crc_table[1][(c >> 16) & 0xff] ^ crc_table[0][c >> 24]
+#define DOLIT32 DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4
+
+/* ========================================================================= */
+local unsigned long crc32_little(crc, buf, len)
+    unsigned long crc;
+    const unsigned char FAR *buf;
+    z_size_t len;
+{
+    register z_crc_t c;
+    register const z_crc_t FAR *buf4;
+
+    c = (z_crc_t)crc;
+    c = ~c;
+    while (len && ((ptrdiff_t)buf & 3)) {
+        c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8);
+        len--;
+    }
+
+    buf4 = (const z_crc_t FAR *)(const void FAR *)buf;
+    while (len >= 32) {
+        DOLIT32;
+        len -= 32;
+    }
+    while (len >= 4) {
+        DOLIT4;
+        len -= 4;
+    }
+    buf = (const unsigned char FAR *)buf4;
+
+    if (len) do {
+        c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8);
+    } while (--len);
+    c = ~c;
+    return (unsigned long)c;
+}
+
+/* ========================================================================= */
+#define DOBIG4 c ^= *buf4++; \
+        c = crc_table[4][c & 0xff] ^ crc_table[5][(c >> 8) & 0xff] ^ \
+            crc_table[6][(c >> 16) & 0xff] ^ crc_table[7][c >> 24]
+#define DOBIG32 DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4
+
+/* ========================================================================= */
+local unsigned long crc32_big(crc, buf, len)
+    unsigned long crc;
+    const unsigned char FAR *buf;
+    z_size_t len;
+{
+    register z_crc_t c;
+    register const z_crc_t FAR *buf4;
+
+    c = ZSWAP32((z_crc_t)crc);
+    c = ~c;
+    while (len && ((ptrdiff_t)buf & 3)) {
+        c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8);
+        len--;
+    }
+
+    buf4 = (const z_crc_t FAR *)(const void FAR *)buf;
+    while (len >= 32) {
+        DOBIG32;
+        len -= 32;
+    }
+    while (len >= 4) {
+        DOBIG4;
+        len -= 4;
+    }
+    buf = (const unsigned char FAR *)buf4;
+
+    if (len) do {
+        c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8);
+    } while (--len);
+    c = ~c;
+    return (unsigned long)(ZSWAP32(c));
+}
+
+#endif /* BYFOUR */
+
+#define GF2_DIM 32      /* dimension of GF(2) vectors (length of CRC) */
+
+/* ========================================================================= */
+local unsigned long gf2_matrix_times(mat, vec)
+    unsigned long *mat;
+    unsigned long vec;
+{
+    unsigned long sum;
+
+    sum = 0;
+    while (vec) {
+        if (vec & 1)
+            sum ^= *mat;
+        vec >>= 1;
+        mat++;
+    }
+    return sum;
+}
+
+/* ========================================================================= */
+local void gf2_matrix_square(square, mat)
+    unsigned long *square;
+    unsigned long *mat;
+{
+    int n;
+
+    for (n = 0; n < GF2_DIM; n++)
+        square[n] = gf2_matrix_times(mat, mat[n]);
+}
+
+/* ========================================================================= */
+local uLong crc32_combine_(crc1, crc2, len2)
+    uLong crc1;
+    uLong crc2;
+    z_off64_t len2;
+{
+    int n;
+    unsigned long row;
+    unsigned long even[GF2_DIM];    /* even-power-of-two zeros operator */
+    unsigned long odd[GF2_DIM];     /* odd-power-of-two zeros operator */
+
+    /* degenerate case (also disallow negative lengths) */
+    if (len2 <= 0)
+        return crc1;
+
+    /* put operator for one zero bit in odd */
+    odd[0] = 0xedb88320UL;          /* CRC-32 polynomial */
+    row = 1;
+    for (n = 1; n < GF2_DIM; n++) {
+        odd[n] = row;
+        row <<= 1;
+    }
+
+    /* put operator for two zero bits in even */
+    gf2_matrix_square(even, odd);
+
+    /* put operator for four zero bits in odd */
+    gf2_matrix_square(odd, even);
+
+    /* apply len2 zeros to crc1 (first square will put the operator for one
+       zero byte, eight zero bits, in even) */
+    do {
+        /* apply zeros operator for this bit of len2 */
+        gf2_matrix_square(even, odd);
+        if (len2 & 1)
+            crc1 = gf2_matrix_times(even, crc1);
+        len2 >>= 1;
+
+        /* if no more bits set, then done */
+        if (len2 == 0)
+            break;
+
+        /* another iteration of the loop with odd and even swapped */
+        gf2_matrix_square(odd, even);
+        if (len2 & 1)
+            crc1 = gf2_matrix_times(odd, crc1);
+        len2 >>= 1;
+
+        /* if no more bits set, then done */
+    } while (len2 != 0);
+
+    /* return combined crc */
+    crc1 ^= crc2;
+    return crc1;
+}
+
+/* ========================================================================= */
+uLong ZEXPORT crc32_combine(crc1, crc2, len2)
+    uLong crc1;
+    uLong crc2;
+    z_off_t len2;
+{
+    return crc32_combine_(crc1, crc2, len2);
+}
+
+uLong ZEXPORT crc32_combine64(crc1, crc2, len2)
+    uLong crc1;
+    uLong crc2;
+    z_off64_t len2;
+{
+    return crc32_combine_(crc1, crc2, len2);
+}

vendor/libgit2-sys/libgit2/deps/zlib/crc32.h

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/crc32.h b/vendor/libgit2-sys/libgit2/deps/zlib/crc32.h
new file mode 100644
index 0000000..9e0c778
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/crc32.h
@@ -0,0 +1,441 @@
+/* crc32.h -- tables for rapid CRC calculation
+ * Generated automatically by crc32.c
+ */
+
+local const z_crc_t FAR crc_table[TBLS][256] =
+{
+  {
+    0x00000000UL, 0x77073096UL, 0xee0e612cUL, 0x990951baUL, 0x076dc419UL,
+    0x706af48fUL, 0xe963a535UL, 0x9e6495a3UL, 0x0edb8832UL, 0x79dcb8a4UL,
+    0xe0d5e91eUL, 0x97d2d988UL, 0x09b64c2bUL, 0x7eb17cbdUL, 0xe7b82d07UL,
+    0x90bf1d91UL, 0x1db71064UL, 0x6ab020f2UL, 0xf3b97148UL, 0x84be41deUL,
+    0x1adad47dUL, 0x6ddde4ebUL, 0xf4d4b551UL, 0x83d385c7UL, 0x136c9856UL,
+    0x646ba8c0UL, 0xfd62f97aUL, 0x8a65c9ecUL, 0x14015c4fUL, 0x63066cd9UL,
+    0xfa0f3d63UL, 0x8d080df5UL, 0x3b6e20c8UL, 0x4c69105eUL, 0xd56041e4UL,
+    0xa2677172UL, 0x3c03e4d1UL, 0x4b04d447UL, 0xd20d85fdUL, 0xa50ab56bUL,
+    0x35b5a8faUL, 0x42b2986cUL, 0xdbbbc9d6UL, 0xacbcf940UL, 0x32d86ce3UL,
+    0x45df5c75UL, 0xdcd60dcfUL, 0xabd13d59UL, 0x26d930acUL, 0x51de003aUL,
+    0xc8d75180UL, 0xbfd06116UL, 0x21b4f4b5UL, 0x56b3c423UL, 0xcfba9599UL,
+    0xb8bda50fUL, 0x2802b89eUL, 0x5f058808UL, 0xc60cd9b2UL, 0xb10be924UL,
+    0x2f6f7c87UL, 0x58684c11UL, 0xc1611dabUL, 0xb6662d3dUL, 0x76dc4190UL,
+    0x01db7106UL, 0x98d220bcUL, 0xefd5102aUL, 0x71b18589UL, 0x06b6b51fUL,
+    0x9fbfe4a5UL, 0xe8b8d433UL, 0x7807c9a2UL, 0x0f00f934UL, 0x9609a88eUL,
+    0xe10e9818UL, 0x7f6a0dbbUL, 0x086d3d2dUL, 0x91646c97UL, 0xe6635c01UL,
+    0x6b6b51f4UL, 0x1c6c6162UL, 0x856530d8UL, 0xf262004eUL, 0x6c0695edUL,
+    0x1b01a57bUL, 0x8208f4c1UL, 0xf50fc457UL, 0x65b0d9c6UL, 0x12b7e950UL,
+    0x8bbeb8eaUL, 0xfcb9887cUL, 0x62dd1ddfUL, 0x15da2d49UL, 0x8cd37cf3UL,
+    0xfbd44c65UL, 0x4db26158UL, 0x3ab551ceUL, 0xa3bc0074UL, 0xd4bb30e2UL,
+    0x4adfa541UL, 0x3dd895d7UL, 0xa4d1c46dUL, 0xd3d6f4fbUL, 0x4369e96aUL,
+    0x346ed9fcUL, 0xad678846UL, 0xda60b8d0UL, 0x44042d73UL, 0x33031de5UL,
+    0xaa0a4c5fUL, 0xdd0d7cc9UL, 0x5005713cUL, 0x270241aaUL, 0xbe0b1010UL,
+    0xc90c2086UL, 0x5768b525UL, 0x206f85b3UL, 0xb966d409UL, 0xce61e49fUL,
+    0x5edef90eUL, 0x29d9c998UL, 0xb0d09822UL, 0xc7d7a8b4UL, 0x59b33d17UL,
+    0x2eb40d81UL, 0xb7bd5c3bUL, 0xc0ba6cadUL, 0xedb88320UL, 0x9abfb3b6UL,
+    0x03b6e20cUL, 0x74b1d29aUL, 0xead54739UL, 0x9dd277afUL, 0x04db2615UL,
+    0x73dc1683UL, 0xe3630b12UL, 0x94643b84UL, 0x0d6d6a3eUL, 0x7a6a5aa8UL,
+    0xe40ecf0bUL, 0x9309ff9dUL, 0x0a00ae27UL, 0x7d079eb1UL, 0xf00f9344UL,
+    0x8708a3d2UL, 0x1e01f268UL, 0x6906c2feUL, 0xf762575dUL, 0x806567cbUL,
+    0x196c3671UL, 0x6e6b06e7UL, 0xfed41b76UL, 0x89d32be0UL, 0x10da7a5aUL,
+    0x67dd4accUL, 0xf9b9df6fUL, 0x8ebeeff9UL, 0x17b7be43UL, 0x60b08ed5UL,
+    0xd6d6a3e8UL, 0xa1d1937eUL, 0x38d8c2c4UL, 0x4fdff252UL, 0xd1bb67f1UL,
+    0xa6bc5767UL, 0x3fb506ddUL, 0x48b2364bUL, 0xd80d2bdaUL, 0xaf0a1b4cUL,
+    0x36034af6UL, 0x41047a60UL, 0xdf60efc3UL, 0xa867df55UL, 0x316e8eefUL,
+    0x4669be79UL, 0xcb61b38cUL, 0xbc66831aUL, 0x256fd2a0UL, 0x5268e236UL,
+    0xcc0c7795UL, 0xbb0b4703UL, 0x220216b9UL, 0x5505262fUL, 0xc5ba3bbeUL,
+    0xb2bd0b28UL, 0x2bb45a92UL, 0x5cb36a04UL, 0xc2d7ffa7UL, 0xb5d0cf31UL,
+    0x2cd99e8bUL, 0x5bdeae1dUL, 0x9b64c2b0UL, 0xec63f226UL, 0x756aa39cUL,
+    0x026d930aUL, 0x9c0906a9UL, 0xeb0e363fUL, 0x72076785UL, 0x05005713UL,
+    0x95bf4a82UL, 0xe2b87a14UL, 0x7bb12baeUL, 0x0cb61b38UL, 0x92d28e9bUL,
+    0xe5d5be0dUL, 0x7cdcefb7UL, 0x0bdbdf21UL, 0x86d3d2d4UL, 0xf1d4e242UL,
+    0x68ddb3f8UL, 0x1fda836eUL, 0x81be16cdUL, 0xf6b9265bUL, 0x6fb077e1UL,
+    0x18b74777UL, 0x88085ae6UL, 0xff0f6a70UL, 0x66063bcaUL, 0x11010b5cUL,
+    0x8f659effUL, 0xf862ae69UL, 0x616bffd3UL, 0x166ccf45UL, 0xa00ae278UL,
+    0xd70dd2eeUL, 0x4e048354UL, 0x3903b3c2UL, 0xa7672661UL, 0xd06016f7UL,
+    0x4969474dUL, 0x3e6e77dbUL, 0xaed16a4aUL, 0xd9d65adcUL, 0x40df0b66UL,
+    0x37d83bf0UL, 0xa9bcae53UL, 0xdebb9ec5UL, 0x47b2cf7fUL, 0x30b5ffe9UL,
+    0xbdbdf21cUL, 0xcabac28aUL, 0x53b39330UL, 0x24b4a3a6UL, 0xbad03605UL,
+    0xcdd70693UL, 0x54de5729UL, 0x23d967bfUL, 0xb3667a2eUL, 0xc4614ab8UL,
+    0x5d681b02UL, 0x2a6f2b94UL, 0xb40bbe37UL, 0xc30c8ea1UL, 0x5a05df1bUL,
+    0x2d02ef8dUL
+#ifdef BYFOUR
+  },
+  {
+    0x00000000UL, 0x191b3141UL, 0x32366282UL, 0x2b2d53c3UL, 0x646cc504UL,
+    0x7d77f445UL, 0x565aa786UL, 0x4f4196c7UL, 0xc8d98a08UL, 0xd1c2bb49UL,
+    0xfaefe88aUL, 0xe3f4d9cbUL, 0xacb54f0cUL, 0xb5ae7e4dUL, 0x9e832d8eUL,
+    0x87981ccfUL, 0x4ac21251UL, 0x53d92310UL, 0x78f470d3UL, 0x61ef4192UL,
+    0x2eaed755UL, 0x37b5e614UL, 0x1c98b5d7UL, 0x05838496UL, 0x821b9859UL,
+    0x9b00a918UL, 0xb02dfadbUL, 0xa936cb9aUL, 0xe6775d5dUL, 0xff6c6c1cUL,
+    0xd4413fdfUL, 0xcd5a0e9eUL, 0x958424a2UL, 0x8c9f15e3UL, 0xa7b24620UL,
+    0xbea97761UL, 0xf1e8e1a6UL, 0xe8f3d0e7UL, 0xc3de8324UL, 0xdac5b265UL,
+    0x5d5daeaaUL, 0x44469febUL, 0x6f6bcc28UL, 0x7670fd69UL, 0x39316baeUL,
+    0x202a5aefUL, 0x0b07092cUL, 0x121c386dUL, 0xdf4636f3UL, 0xc65d07b2UL,
+    0xed705471UL, 0xf46b6530UL, 0xbb2af3f7UL, 0xa231c2b6UL, 0x891c9175UL,
+    0x9007a034UL, 0x179fbcfbUL, 0x0e848dbaUL, 0x25a9de79UL, 0x3cb2ef38UL,
+    0x73f379ffUL, 0x6ae848beUL, 0x41c51b7dUL, 0x58de2a3cUL, 0xf0794f05UL,
+    0xe9627e44UL, 0xc24f2d87UL, 0xdb541cc6UL, 0x94158a01UL, 0x8d0ebb40UL,
+    0xa623e883UL, 0xbf38d9c2UL, 0x38a0c50dUL, 0x21bbf44cUL, 0x0a96a78fUL,
+    0x138d96ceUL, 0x5ccc0009UL, 0x45d73148UL, 0x6efa628bUL, 0x77e153caUL,
+    0xbabb5d54UL, 0xa3a06c15UL, 0x888d3fd6UL, 0x91960e97UL, 0xded79850UL,
+    0xc7cca911UL, 0xece1fad2UL, 0xf5facb93UL, 0x7262d75cUL, 0x6b79e61dUL,
+    0x4054b5deUL, 0x594f849fUL, 0x160e1258UL, 0x0f152319UL, 0x243870daUL,
+    0x3d23419bUL, 0x65fd6ba7UL, 0x7ce65ae6UL, 0x57cb0925UL, 0x4ed03864UL,
+    0x0191aea3UL, 0x188a9fe2UL, 0x33a7cc21UL, 0x2abcfd60UL, 0xad24e1afUL,
+    0xb43fd0eeUL, 0x9f12832dUL, 0x8609b26cUL, 0xc94824abUL, 0xd05315eaUL,
+    0xfb7e4629UL, 0xe2657768UL, 0x2f3f79f6UL, 0x362448b7UL, 0x1d091b74UL,
+    0x04122a35UL, 0x4b53bcf2UL, 0x52488db3UL, 0x7965de70UL, 0x607eef31UL,
+    0xe7e6f3feUL, 0xfefdc2bfUL, 0xd5d0917cUL, 0xcccba03dUL, 0x838a36faUL,
+    0x9a9107bbUL, 0xb1bc5478UL, 0xa8a76539UL, 0x3b83984bUL, 0x2298a90aUL,
+    0x09b5fac9UL, 0x10aecb88UL, 0x5fef5d4fUL, 0x46f46c0eUL, 0x6dd93fcdUL,
+    0x74c20e8cUL, 0xf35a1243UL, 0xea412302UL, 0xc16c70c1UL, 0xd8774180UL,
+    0x9736d747UL, 0x8e2de606UL, 0xa500b5c5UL, 0xbc1b8484UL, 0x71418a1aUL,
+    0x685abb5bUL, 0x4377e898UL, 0x5a6cd9d9UL, 0x152d4f1eUL, 0x0c367e5fUL,
+    0x271b2d9cUL, 0x3e001cddUL, 0xb9980012UL, 0xa0833153UL, 0x8bae6290UL,
+    0x92b553d1UL, 0xddf4c516UL, 0xc4eff457UL, 0xefc2a794UL, 0xf6d996d5UL,
+    0xae07bce9UL, 0xb71c8da8UL, 0x9c31de6bUL, 0x852aef2aUL, 0xca6b79edUL,
+    0xd37048acUL, 0xf85d1b6fUL, 0xe1462a2eUL, 0x66de36e1UL, 0x7fc507a0UL,
+    0x54e85463UL, 0x4df36522UL, 0x02b2f3e5UL, 0x1ba9c2a4UL, 0x30849167UL,
+    0x299fa026UL, 0xe4c5aeb8UL, 0xfdde9ff9UL, 0xd6f3cc3aUL, 0xcfe8fd7bUL,
+    0x80a96bbcUL, 0x99b25afdUL, 0xb29f093eUL, 0xab84387fUL, 0x2c1c24b0UL,
+    0x350715f1UL, 0x1e2a4632UL, 0x07317773UL, 0x4870e1b4UL, 0x516bd0f5UL,
+    0x7a468336UL, 0x635db277UL, 0xcbfad74eUL, 0xd2e1e60fUL, 0xf9ccb5ccUL,
+    0xe0d7848dUL, 0xaf96124aUL, 0xb68d230bUL, 0x9da070c8UL, 0x84bb4189UL,
+    0x03235d46UL, 0x1a386c07UL, 0x31153fc4UL, 0x280e0e85UL, 0x674f9842UL,
+    0x7e54a903UL, 0x5579fac0UL, 0x4c62cb81UL, 0x8138c51fUL, 0x9823f45eUL,
+    0xb30ea79dUL, 0xaa1596dcUL, 0xe554001bUL, 0xfc4f315aUL, 0xd7626299UL,
+    0xce7953d8UL, 0x49e14f17UL, 0x50fa7e56UL, 0x7bd72d95UL, 0x62cc1cd4UL,
+    0x2d8d8a13UL, 0x3496bb52UL, 0x1fbbe891UL, 0x06a0d9d0UL, 0x5e7ef3ecUL,
+    0x4765c2adUL, 0x6c48916eUL, 0x7553a02fUL, 0x3a1236e8UL, 0x230907a9UL,
+    0x0824546aUL, 0x113f652bUL, 0x96a779e4UL, 0x8fbc48a5UL, 0xa4911b66UL,
+    0xbd8a2a27UL, 0xf2cbbce0UL, 0xebd08da1UL, 0xc0fdde62UL, 0xd9e6ef23UL,
+    0x14bce1bdUL, 0x0da7d0fcUL, 0x268a833fUL, 0x3f91b27eUL, 0x70d024b9UL,
+    0x69cb15f8UL, 0x42e6463bUL, 0x5bfd777aUL, 0xdc656bb5UL, 0xc57e5af4UL,
+    0xee530937UL, 0xf7483876UL, 0xb809aeb1UL, 0xa1129ff0UL, 0x8a3fcc33UL,
+    0x9324fd72UL
+  },
+  {
+    0x00000000UL, 0x01c26a37UL, 0x0384d46eUL, 0x0246be59UL, 0x0709a8dcUL,
+    0x06cbc2ebUL, 0x048d7cb2UL, 0x054f1685UL, 0x0e1351b8UL, 0x0fd13b8fUL,
+    0x0d9785d6UL, 0x0c55efe1UL, 0x091af964UL, 0x08d89353UL, 0x0a9e2d0aUL,
+    0x0b5c473dUL, 0x1c26a370UL, 0x1de4c947UL, 0x1fa2771eUL, 0x1e601d29UL,
+    0x1b2f0bacUL, 0x1aed619bUL, 0x18abdfc2UL, 0x1969b5f5UL, 0x1235f2c8UL,
+    0x13f798ffUL, 0x11b126a6UL, 0x10734c91UL, 0x153c5a14UL, 0x14fe3023UL,
+    0x16b88e7aUL, 0x177ae44dUL, 0x384d46e0UL, 0x398f2cd7UL, 0x3bc9928eUL,
+    0x3a0bf8b9UL, 0x3f44ee3cUL, 0x3e86840bUL, 0x3cc03a52UL, 0x3d025065UL,
+    0x365e1758UL, 0x379c7d6fUL, 0x35dac336UL, 0x3418a901UL, 0x3157bf84UL,
+    0x3095d5b3UL, 0x32d36beaUL, 0x331101ddUL, 0x246be590UL, 0x25a98fa7UL,
+    0x27ef31feUL, 0x262d5bc9UL, 0x23624d4cUL, 0x22a0277bUL, 0x20e69922UL,
+    0x2124f315UL, 0x2a78b428UL, 0x2bbade1fUL, 0x29fc6046UL, 0x283e0a71UL,
+    0x2d711cf4UL, 0x2cb376c3UL, 0x2ef5c89aUL, 0x2f37a2adUL, 0x709a8dc0UL,
+    0x7158e7f7UL, 0x731e59aeUL, 0x72dc3399UL, 0x7793251cUL, 0x76514f2bUL,
+    0x7417f172UL, 0x75d59b45UL, 0x7e89dc78UL, 0x7f4bb64fUL, 0x7d0d0816UL,
+    0x7ccf6221UL, 0x798074a4UL, 0x78421e93UL, 0x7a04a0caUL, 0x7bc6cafdUL,
+    0x6cbc2eb0UL, 0x6d7e4487UL, 0x6f38fadeUL, 0x6efa90e9UL, 0x6bb5866cUL,
+    0x6a77ec5bUL, 0x68315202UL, 0x69f33835UL, 0x62af7f08UL, 0x636d153fUL,
+    0x612bab66UL, 0x60e9c151UL, 0x65a6d7d4UL, 0x6464bde3UL, 0x662203baUL,
+    0x67e0698dUL, 0x48d7cb20UL, 0x4915a117UL, 0x4b531f4eUL, 0x4a917579UL,
+    0x4fde63fcUL, 0x4e1c09cbUL, 0x4c5ab792UL, 0x4d98dda5UL, 0x46c49a98UL,
+    0x4706f0afUL, 0x45404ef6UL, 0x448224c1UL, 0x41cd3244UL, 0x400f5873UL,
+    0x4249e62aUL, 0x438b8c1dUL, 0x54f16850UL, 0x55330267UL, 0x5775bc3eUL,
+    0x56b7d609UL, 0x53f8c08cUL, 0x523aaabbUL, 0x507c14e2UL, 0x51be7ed5UL,
+    0x5ae239e8UL, 0x5b2053dfUL, 0x5966ed86UL, 0x58a487b1UL, 0x5deb9134UL,
+    0x5c29fb03UL, 0x5e6f455aUL, 0x5fad2f6dUL, 0xe1351b80UL, 0xe0f771b7UL,
+    0xe2b1cfeeUL, 0xe373a5d9UL, 0xe63cb35cUL, 0xe7fed96bUL, 0xe5b86732UL,
+    0xe47a0d05UL, 0xef264a38UL, 0xeee4200fUL, 0xeca29e56UL, 0xed60f461UL,
+    0xe82fe2e4UL, 0xe9ed88d3UL, 0xebab368aUL, 0xea695cbdUL, 0xfd13b8f0UL,
+    0xfcd1d2c7UL, 0xfe976c9eUL, 0xff5506a9UL, 0xfa1a102cUL, 0xfbd87a1bUL,
+    0xf99ec442UL, 0xf85cae75UL, 0xf300e948UL, 0xf2c2837fUL, 0xf0843d26UL,
+    0xf1465711UL, 0xf4094194UL, 0xf5cb2ba3UL, 0xf78d95faUL, 0xf64fffcdUL,
+    0xd9785d60UL, 0xd8ba3757UL, 0xdafc890eUL, 0xdb3ee339UL, 0xde71f5bcUL,
+    0xdfb39f8bUL, 0xddf521d2UL, 0xdc374be5UL, 0xd76b0cd8UL, 0xd6a966efUL,
+    0xd4efd8b6UL, 0xd52db281UL, 0xd062a404UL, 0xd1a0ce33UL, 0xd3e6706aUL,
+    0xd2241a5dUL, 0xc55efe10UL, 0xc49c9427UL, 0xc6da2a7eUL, 0xc7184049UL,
+    0xc25756ccUL, 0xc3953cfbUL, 0xc1d382a2UL, 0xc011e895UL, 0xcb4dafa8UL,
+    0xca8fc59fUL, 0xc8c97bc6UL, 0xc90b11f1UL, 0xcc440774UL, 0xcd866d43UL,
+    0xcfc0d31aUL, 0xce02b92dUL, 0x91af9640UL, 0x906dfc77UL, 0x922b422eUL,
+    0x93e92819UL, 0x96a63e9cUL, 0x976454abUL, 0x9522eaf2UL, 0x94e080c5UL,
+    0x9fbcc7f8UL, 0x9e7eadcfUL, 0x9c381396UL, 0x9dfa79a1UL, 0x98b56f24UL,
+    0x99770513UL, 0x9b31bb4aUL, 0x9af3d17dUL, 0x8d893530UL, 0x8c4b5f07UL,
+    0x8e0de15eUL, 0x8fcf8b69UL, 0x8a809decUL, 0x8b42f7dbUL, 0x89044982UL,
+    0x88c623b5UL, 0x839a6488UL, 0x82580ebfUL, 0x801eb0e6UL, 0x81dcdad1UL,
+    0x8493cc54UL, 0x8551a663UL, 0x8717183aUL, 0x86d5720dUL, 0xa9e2d0a0UL,
+    0xa820ba97UL, 0xaa6604ceUL, 0xaba46ef9UL, 0xaeeb787cUL, 0xaf29124bUL,
+    0xad6fac12UL, 0xacadc625UL, 0xa7f18118UL, 0xa633eb2fUL, 0xa4755576UL,
+    0xa5b73f41UL, 0xa0f829c4UL, 0xa13a43f3UL, 0xa37cfdaaUL, 0xa2be979dUL,
+    0xb5c473d0UL, 0xb40619e7UL, 0xb640a7beUL, 0xb782cd89UL, 0xb2cddb0cUL,
+    0xb30fb13bUL, 0xb1490f62UL, 0xb08b6555UL, 0xbbd72268UL, 0xba15485fUL,
+    0xb853f606UL, 0xb9919c31UL, 0xbcde8ab4UL, 0xbd1ce083UL, 0xbf5a5edaUL,
+    0xbe9834edUL
+  },
+  {
+    0x00000000UL, 0xb8bc6765UL, 0xaa09c88bUL, 0x12b5afeeUL, 0x8f629757UL,
+    0x37def032UL, 0x256b5fdcUL, 0x9dd738b9UL, 0xc5b428efUL, 0x7d084f8aUL,
+    0x6fbde064UL, 0xd7018701UL, 0x4ad6bfb8UL, 0xf26ad8ddUL, 0xe0df7733UL,
+    0x58631056UL, 0x5019579fUL, 0xe8a530faUL, 0xfa109f14UL, 0x42acf871UL,
+    0xdf7bc0c8UL, 0x67c7a7adUL, 0x75720843UL, 0xcdce6f26UL, 0x95ad7f70UL,
+    0x2d111815UL, 0x3fa4b7fbUL, 0x8718d09eUL, 0x1acfe827UL, 0xa2738f42UL,
+    0xb0c620acUL, 0x087a47c9UL, 0xa032af3eUL, 0x188ec85bUL, 0x0a3b67b5UL,
+    0xb28700d0UL, 0x2f503869UL, 0x97ec5f0cUL, 0x8559f0e2UL, 0x3de59787UL,
+    0x658687d1UL, 0xdd3ae0b4UL, 0xcf8f4f5aUL, 0x7733283fUL, 0xeae41086UL,
+    0x525877e3UL, 0x40edd80dUL, 0xf851bf68UL, 0xf02bf8a1UL, 0x48979fc4UL,
+    0x5a22302aUL, 0xe29e574fUL, 0x7f496ff6UL, 0xc7f50893UL, 0xd540a77dUL,
+    0x6dfcc018UL, 0x359fd04eUL, 0x8d23b72bUL, 0x9f9618c5UL, 0x272a7fa0UL,
+    0xbafd4719UL, 0x0241207cUL, 0x10f48f92UL, 0xa848e8f7UL, 0x9b14583dUL,
+    0x23a83f58UL, 0x311d90b6UL, 0x89a1f7d3UL, 0x1476cf6aUL, 0xaccaa80fUL,
+    0xbe7f07e1UL, 0x06c36084UL, 0x5ea070d2UL, 0xe61c17b7UL, 0xf4a9b859UL,
+    0x4c15df3cUL, 0xd1c2e785UL, 0x697e80e0UL, 0x7bcb2f0eUL, 0xc377486bUL,
+    0xcb0d0fa2UL, 0x73b168c7UL, 0x6104c729UL, 0xd9b8a04cUL, 0x446f98f5UL,
+    0xfcd3ff90UL, 0xee66507eUL, 0x56da371bUL, 0x0eb9274dUL, 0xb6054028UL,
+    0xa4b0efc6UL, 0x1c0c88a3UL, 0x81dbb01aUL, 0x3967d77fUL, 0x2bd27891UL,
+    0x936e1ff4UL, 0x3b26f703UL, 0x839a9066UL, 0x912f3f88UL, 0x299358edUL,
+    0xb4446054UL, 0x0cf80731UL, 0x1e4da8dfUL, 0xa6f1cfbaUL, 0xfe92dfecUL,
+    0x462eb889UL, 0x549b1767UL, 0xec277002UL, 0x71f048bbUL, 0xc94c2fdeUL,
+    0xdbf98030UL, 0x6345e755UL, 0x6b3fa09cUL, 0xd383c7f9UL, 0xc1366817UL,
+    0x798a0f72UL, 0xe45d37cbUL, 0x5ce150aeUL, 0x4e54ff40UL, 0xf6e89825UL,
+    0xae8b8873UL, 0x1637ef16UL, 0x048240f8UL, 0xbc3e279dUL, 0x21e91f24UL,
+    0x99557841UL, 0x8be0d7afUL, 0x335cb0caUL, 0xed59b63bUL, 0x55e5d15eUL,
+    0x47507eb0UL, 0xffec19d5UL, 0x623b216cUL, 0xda874609UL, 0xc832e9e7UL,
+    0x708e8e82UL, 0x28ed9ed4UL, 0x9051f9b1UL, 0x82e4565fUL, 0x3a58313aUL,
+    0xa78f0983UL, 0x1f336ee6UL, 0x0d86c108UL, 0xb53aa66dUL, 0xbd40e1a4UL,
+    0x05fc86c1UL, 0x1749292fUL, 0xaff54e4aUL, 0x322276f3UL, 0x8a9e1196UL,
+    0x982bbe78UL, 0x2097d91dUL, 0x78f4c94bUL, 0xc048ae2eUL, 0xd2fd01c0UL,
+    0x6a4166a5UL, 0xf7965e1cUL, 0x4f2a3979UL, 0x5d9f9697UL, 0xe523f1f2UL,
+    0x4d6b1905UL, 0xf5d77e60UL, 0xe762d18eUL, 0x5fdeb6ebUL, 0xc2098e52UL,
+    0x7ab5e937UL, 0x680046d9UL, 0xd0bc21bcUL, 0x88df31eaUL, 0x3063568fUL,
+    0x22d6f961UL, 0x9a6a9e04UL, 0x07bda6bdUL, 0xbf01c1d8UL, 0xadb46e36UL,
+    0x15080953UL, 0x1d724e9aUL, 0xa5ce29ffUL, 0xb77b8611UL, 0x0fc7e174UL,
+    0x9210d9cdUL, 0x2aacbea8UL, 0x38191146UL, 0x80a57623UL, 0xd8c66675UL,
+    0x607a0110UL, 0x72cfaefeUL, 0xca73c99bUL, 0x57a4f122UL, 0xef189647UL,
+    0xfdad39a9UL, 0x45115eccUL, 0x764dee06UL, 0xcef18963UL, 0xdc44268dUL,
+    0x64f841e8UL, 0xf92f7951UL, 0x41931e34UL, 0x5326b1daUL, 0xeb9ad6bfUL,
+    0xb3f9c6e9UL, 0x0b45a18cUL, 0x19f00e62UL, 0xa14c6907UL, 0x3c9b51beUL,
+    0x842736dbUL, 0x96929935UL, 0x2e2efe50UL, 0x2654b999UL, 0x9ee8defcUL,
+    0x8c5d7112UL, 0x34e11677UL, 0xa9362eceUL, 0x118a49abUL, 0x033fe645UL,
+    0xbb838120UL, 0xe3e09176UL, 0x5b5cf613UL, 0x49e959fdUL, 0xf1553e98UL,
+    0x6c820621UL, 0xd43e6144UL, 0xc68bceaaUL, 0x7e37a9cfUL, 0xd67f4138UL,
+    0x6ec3265dUL, 0x7c7689b3UL, 0xc4caeed6UL, 0x591dd66fUL, 0xe1a1b10aUL,
+    0xf3141ee4UL, 0x4ba87981UL, 0x13cb69d7UL, 0xab770eb2UL, 0xb9c2a15cUL,
+    0x017ec639UL, 0x9ca9fe80UL, 0x241599e5UL, 0x36a0360bUL, 0x8e1c516eUL,
+    0x866616a7UL, 0x3eda71c2UL, 0x2c6fde2cUL, 0x94d3b949UL, 0x090481f0UL,
+    0xb1b8e695UL, 0xa30d497bUL, 0x1bb12e1eUL, 0x43d23e48UL, 0xfb6e592dUL,
+    0xe9dbf6c3UL, 0x516791a6UL, 0xccb0a91fUL, 0x740cce7aUL, 0x66b96194UL,
+    0xde0506f1UL
+  },
+  {
+    0x00000000UL, 0x96300777UL, 0x2c610eeeUL, 0xba510999UL, 0x19c46d07UL,
+    0x8ff46a70UL, 0x35a563e9UL, 0xa395649eUL, 0x3288db0eUL, 0xa4b8dc79UL,
+    0x1ee9d5e0UL, 0x88d9d297UL, 0x2b4cb609UL, 0xbd7cb17eUL, 0x072db8e7UL,
+    0x911dbf90UL, 0x6410b71dUL, 0xf220b06aUL, 0x4871b9f3UL, 0xde41be84UL,
+    0x7dd4da1aUL, 0xebe4dd6dUL, 0x51b5d4f4UL, 0xc785d383UL, 0x56986c13UL,
+    0xc0a86b64UL, 0x7af962fdUL, 0xecc9658aUL, 0x4f5c0114UL, 0xd96c0663UL,
+    0x633d0ffaUL, 0xf50d088dUL, 0xc8206e3bUL, 0x5e10694cUL, 0xe44160d5UL,
+    0x727167a2UL, 0xd1e4033cUL, 0x47d4044bUL, 0xfd850dd2UL, 0x6bb50aa5UL,
+    0xfaa8b535UL, 0x6c98b242UL, 0xd6c9bbdbUL, 0x40f9bcacUL, 0xe36cd832UL,
+    0x755cdf45UL, 0xcf0dd6dcUL, 0x593dd1abUL, 0xac30d926UL, 0x3a00de51UL,
+    0x8051d7c8UL, 0x1661d0bfUL, 0xb5f4b421UL, 0x23c4b356UL, 0x9995bacfUL,
+    0x0fa5bdb8UL, 0x9eb80228UL, 0x0888055fUL, 0xb2d90cc6UL, 0x24e90bb1UL,
+    0x877c6f2fUL, 0x114c6858UL, 0xab1d61c1UL, 0x3d2d66b6UL, 0x9041dc76UL,
+    0x0671db01UL, 0xbc20d298UL, 0x2a10d5efUL, 0x8985b171UL, 0x1fb5b606UL,
+    0xa5e4bf9fUL, 0x33d4b8e8UL, 0xa2c90778UL, 0x34f9000fUL, 0x8ea80996UL,
+    0x18980ee1UL, 0xbb0d6a7fUL, 0x2d3d6d08UL, 0x976c6491UL, 0x015c63e6UL,
+    0xf4516b6bUL, 0x62616c1cUL, 0xd8306585UL, 0x4e0062f2UL, 0xed95066cUL,
+    0x7ba5011bUL, 0xc1f40882UL, 0x57c40ff5UL, 0xc6d9b065UL, 0x50e9b712UL,
+    0xeab8be8bUL, 0x7c88b9fcUL, 0xdf1ddd62UL, 0x492dda15UL, 0xf37cd38cUL,
+    0x654cd4fbUL, 0x5861b24dUL, 0xce51b53aUL, 0x7400bca3UL, 0xe230bbd4UL,
+    0x41a5df4aUL, 0xd795d83dUL, 0x6dc4d1a4UL, 0xfbf4d6d3UL, 0x6ae96943UL,
+    0xfcd96e34UL, 0x468867adUL, 0xd0b860daUL, 0x732d0444UL, 0xe51d0333UL,
+    0x5f4c0aaaUL, 0xc97c0dddUL, 0x3c710550UL, 0xaa410227UL, 0x10100bbeUL,
+    0x86200cc9UL, 0x25b56857UL, 0xb3856f20UL, 0x09d466b9UL, 0x9fe461ceUL,
+    0x0ef9de5eUL, 0x98c9d929UL, 0x2298d0b0UL, 0xb4a8d7c7UL, 0x173db359UL,
+    0x810db42eUL, 0x3b5cbdb7UL, 0xad6cbac0UL, 0x2083b8edUL, 0xb6b3bf9aUL,
+    0x0ce2b603UL, 0x9ad2b174UL, 0x3947d5eaUL, 0xaf77d29dUL, 0x1526db04UL,
+    0x8316dc73UL, 0x120b63e3UL, 0x843b6494UL, 0x3e6a6d0dUL, 0xa85a6a7aUL,
+    0x0bcf0ee4UL, 0x9dff0993UL, 0x27ae000aUL, 0xb19e077dUL, 0x44930ff0UL,
+    0xd2a30887UL, 0x68f2011eUL, 0xfec20669UL, 0x5d5762f7UL, 0xcb676580UL,
+    0x71366c19UL, 0xe7066b6eUL, 0x761bd4feUL, 0xe02bd389UL, 0x5a7ada10UL,
+    0xcc4add67UL, 0x6fdfb9f9UL, 0xf9efbe8eUL, 0x43beb717UL, 0xd58eb060UL,
+    0xe8a3d6d6UL, 0x7e93d1a1UL, 0xc4c2d838UL, 0x52f2df4fUL, 0xf167bbd1UL,
+    0x6757bca6UL, 0xdd06b53fUL, 0x4b36b248UL, 0xda2b0dd8UL, 0x4c1b0aafUL,
+    0xf64a0336UL, 0x607a0441UL, 0xc3ef60dfUL, 0x55df67a8UL, 0xef8e6e31UL,
+    0x79be6946UL, 0x8cb361cbUL, 0x1a8366bcUL, 0xa0d26f25UL, 0x36e26852UL,
+    0x95770cccUL, 0x03470bbbUL, 0xb9160222UL, 0x2f260555UL, 0xbe3bbac5UL,
+    0x280bbdb2UL, 0x925ab42bUL, 0x046ab35cUL, 0xa7ffd7c2UL, 0x31cfd0b5UL,
+    0x8b9ed92cUL, 0x1daede5bUL, 0xb0c2649bUL, 0x26f263ecUL, 0x9ca36a75UL,
+    0x0a936d02UL, 0xa906099cUL, 0x3f360eebUL, 0x85670772UL, 0x13570005UL,
+    0x824abf95UL, 0x147ab8e2UL, 0xae2bb17bUL, 0x381bb60cUL, 0x9b8ed292UL,
+    0x0dbed5e5UL, 0xb7efdc7cUL, 0x21dfdb0bUL, 0xd4d2d386UL, 0x42e2d4f1UL,
+    0xf8b3dd68UL, 0x6e83da1fUL, 0xcd16be81UL, 0x5b26b9f6UL, 0xe177b06fUL,
+    0x7747b718UL, 0xe65a0888UL, 0x706a0fffUL, 0xca3b0666UL, 0x5c0b0111UL,
+    0xff9e658fUL, 0x69ae62f8UL, 0xd3ff6b61UL, 0x45cf6c16UL, 0x78e20aa0UL,
+    0xeed20dd7UL, 0x5483044eUL, 0xc2b30339UL, 0x612667a7UL, 0xf71660d0UL,
+    0x4d476949UL, 0xdb776e3eUL, 0x4a6ad1aeUL, 0xdc5ad6d9UL, 0x660bdf40UL,
+    0xf03bd837UL, 0x53aebca9UL, 0xc59ebbdeUL, 0x7fcfb247UL, 0xe9ffb530UL,
+    0x1cf2bdbdUL, 0x8ac2bacaUL, 0x3093b353UL, 0xa6a3b424UL, 0x0536d0baUL,
+    0x9306d7cdUL, 0x2957de54UL, 0xbf67d923UL, 0x2e7a66b3UL, 0xb84a61c4UL,
+    0x021b685dUL, 0x942b6f2aUL, 0x37be0bb4UL, 0xa18e0cc3UL, 0x1bdf055aUL,
+    0x8def022dUL
+  },
+  {
+    0x00000000UL, 0x41311b19UL, 0x82623632UL, 0xc3532d2bUL, 0x04c56c64UL,
+    0x45f4777dUL, 0x86a75a56UL, 0xc796414fUL, 0x088ad9c8UL, 0x49bbc2d1UL,
+    0x8ae8effaUL, 0xcbd9f4e3UL, 0x0c4fb5acUL, 0x4d7eaeb5UL, 0x8e2d839eUL,
+    0xcf1c9887UL, 0x5112c24aUL, 0x1023d953UL, 0xd370f478UL, 0x9241ef61UL,
+    0x55d7ae2eUL, 0x14e6b537UL, 0xd7b5981cUL, 0x96848305UL, 0x59981b82UL,
+    0x18a9009bUL, 0xdbfa2db0UL, 0x9acb36a9UL, 0x5d5d77e6UL, 0x1c6c6cffUL,
+    0xdf3f41d4UL, 0x9e0e5acdUL, 0xa2248495UL, 0xe3159f8cUL, 0x2046b2a7UL,
+    0x6177a9beUL, 0xa6e1e8f1UL, 0xe7d0f3e8UL, 0x2483dec3UL, 0x65b2c5daUL,
+    0xaaae5d5dUL, 0xeb9f4644UL, 0x28cc6b6fUL, 0x69fd7076UL, 0xae6b3139UL,
+    0xef5a2a20UL, 0x2c09070bUL, 0x6d381c12UL, 0xf33646dfUL, 0xb2075dc6UL,
+    0x715470edUL, 0x30656bf4UL, 0xf7f32abbUL, 0xb6c231a2UL, 0x75911c89UL,
+    0x34a00790UL, 0xfbbc9f17UL, 0xba8d840eUL, 0x79dea925UL, 0x38efb23cUL,
+    0xff79f373UL, 0xbe48e86aUL, 0x7d1bc541UL, 0x3c2ade58UL, 0x054f79f0UL,
+    0x447e62e9UL, 0x872d4fc2UL, 0xc61c54dbUL, 0x018a1594UL, 0x40bb0e8dUL,
+    0x83e823a6UL, 0xc2d938bfUL, 0x0dc5a038UL, 0x4cf4bb21UL, 0x8fa7960aUL,
+    0xce968d13UL, 0x0900cc5cUL, 0x4831d745UL, 0x8b62fa6eUL, 0xca53e177UL,
+    0x545dbbbaUL, 0x156ca0a3UL, 0xd63f8d88UL, 0x970e9691UL, 0x5098d7deUL,
+    0x11a9ccc7UL, 0xd2fae1ecUL, 0x93cbfaf5UL, 0x5cd76272UL, 0x1de6796bUL,
+    0xdeb55440UL, 0x9f844f59UL, 0x58120e16UL, 0x1923150fUL, 0xda703824UL,
+    0x9b41233dUL, 0xa76bfd65UL, 0xe65ae67cUL, 0x2509cb57UL, 0x6438d04eUL,
+    0xa3ae9101UL, 0xe29f8a18UL, 0x21cca733UL, 0x60fdbc2aUL, 0xafe124adUL,
+    0xeed03fb4UL, 0x2d83129fUL, 0x6cb20986UL, 0xab2448c9UL, 0xea1553d0UL,
+    0x29467efbUL, 0x687765e2UL, 0xf6793f2fUL, 0xb7482436UL, 0x741b091dUL,
+    0x352a1204UL, 0xf2bc534bUL, 0xb38d4852UL, 0x70de6579UL, 0x31ef7e60UL,
+    0xfef3e6e7UL, 0xbfc2fdfeUL, 0x7c91d0d5UL, 0x3da0cbccUL, 0xfa368a83UL,
+    0xbb07919aUL, 0x7854bcb1UL, 0x3965a7a8UL, 0x4b98833bUL, 0x0aa99822UL,
+    0xc9fab509UL, 0x88cbae10UL, 0x4f5def5fUL, 0x0e6cf446UL, 0xcd3fd96dUL,
+    0x8c0ec274UL, 0x43125af3UL, 0x022341eaUL, 0xc1706cc1UL, 0x804177d8UL,
+    0x47d73697UL, 0x06e62d8eUL, 0xc5b500a5UL, 0x84841bbcUL, 0x1a8a4171UL,
+    0x5bbb5a68UL, 0x98e87743UL, 0xd9d96c5aUL, 0x1e4f2d15UL, 0x5f7e360cUL,
+    0x9c2d1b27UL, 0xdd1c003eUL, 0x120098b9UL, 0x533183a0UL, 0x9062ae8bUL,
+    0xd153b592UL, 0x16c5f4ddUL, 0x57f4efc4UL, 0x94a7c2efUL, 0xd596d9f6UL,
+    0xe9bc07aeUL, 0xa88d1cb7UL, 0x6bde319cUL, 0x2aef2a85UL, 0xed796bcaUL,
+    0xac4870d3UL, 0x6f1b5df8UL, 0x2e2a46e1UL, 0xe136de66UL, 0xa007c57fUL,
+    0x6354e854UL, 0x2265f34dUL, 0xe5f3b202UL, 0xa4c2a91bUL, 0x67918430UL,
+    0x26a09f29UL, 0xb8aec5e4UL, 0xf99fdefdUL, 0x3accf3d6UL, 0x7bfde8cfUL,
+    0xbc6ba980UL, 0xfd5ab299UL, 0x3e099fb2UL, 0x7f3884abUL, 0xb0241c2cUL,
+    0xf1150735UL, 0x32462a1eUL, 0x73773107UL, 0xb4e17048UL, 0xf5d06b51UL,
+    0x3683467aUL, 0x77b25d63UL, 0x4ed7facbUL, 0x0fe6e1d2UL, 0xccb5ccf9UL,
+    0x8d84d7e0UL, 0x4a1296afUL, 0x0b238db6UL, 0xc870a09dUL, 0x8941bb84UL,
+    0x465d2303UL, 0x076c381aUL, 0xc43f1531UL, 0x850e0e28UL, 0x42984f67UL,
+    0x03a9547eUL, 0xc0fa7955UL, 0x81cb624cUL, 0x1fc53881UL, 0x5ef42398UL,
+    0x9da70eb3UL, 0xdc9615aaUL, 0x1b0054e5UL, 0x5a314ffcUL, 0x996262d7UL,
+    0xd85379ceUL, 0x174fe149UL, 0x567efa50UL, 0x952dd77bUL, 0xd41ccc62UL,
+    0x138a8d2dUL, 0x52bb9634UL, 0x91e8bb1fUL, 0xd0d9a006UL, 0xecf37e5eUL,
+    0xadc26547UL, 0x6e91486cUL, 0x2fa05375UL, 0xe836123aUL, 0xa9070923UL,
+    0x6a542408UL, 0x2b653f11UL, 0xe479a796UL, 0xa548bc8fUL, 0x661b91a4UL,
+    0x272a8abdUL, 0xe0bccbf2UL, 0xa18dd0ebUL, 0x62defdc0UL, 0x23efe6d9UL,
+    0xbde1bc14UL, 0xfcd0a70dUL, 0x3f838a26UL, 0x7eb2913fUL, 0xb924d070UL,
+    0xf815cb69UL, 0x3b46e642UL, 0x7a77fd5bUL, 0xb56b65dcUL, 0xf45a7ec5UL,
+    0x370953eeUL, 0x763848f7UL, 0xb1ae09b8UL, 0xf09f12a1UL, 0x33cc3f8aUL,
+    0x72fd2493UL
+  },
+  {
+    0x00000000UL, 0x376ac201UL, 0x6ed48403UL, 0x59be4602UL, 0xdca80907UL,
+    0xebc2cb06UL, 0xb27c8d04UL, 0x85164f05UL, 0xb851130eUL, 0x8f3bd10fUL,
+    0xd685970dUL, 0xe1ef550cUL, 0x64f91a09UL, 0x5393d808UL, 0x0a2d9e0aUL,
+    0x3d475c0bUL, 0x70a3261cUL, 0x47c9e41dUL, 0x1e77a21fUL, 0x291d601eUL,
+    0xac0b2f1bUL, 0x9b61ed1aUL, 0xc2dfab18UL, 0xf5b56919UL, 0xc8f23512UL,
+    0xff98f713UL, 0xa626b111UL, 0x914c7310UL, 0x145a3c15UL, 0x2330fe14UL,
+    0x7a8eb816UL, 0x4de47a17UL, 0xe0464d38UL, 0xd72c8f39UL, 0x8e92c93bUL,
+    0xb9f80b3aUL, 0x3cee443fUL, 0x0b84863eUL, 0x523ac03cUL, 0x6550023dUL,
+    0x58175e36UL, 0x6f7d9c37UL, 0x36c3da35UL, 0x01a91834UL, 0x84bf5731UL,
+    0xb3d59530UL, 0xea6bd332UL, 0xdd011133UL, 0x90e56b24UL, 0xa78fa925UL,
+    0xfe31ef27UL, 0xc95b2d26UL, 0x4c4d6223UL, 0x7b27a022UL, 0x2299e620UL,
+    0x15f32421UL, 0x28b4782aUL, 0x1fdeba2bUL, 0x4660fc29UL, 0x710a3e28UL,
+    0xf41c712dUL, 0xc376b32cUL, 0x9ac8f52eUL, 0xada2372fUL, 0xc08d9a70UL,
+    0xf7e75871UL, 0xae591e73UL, 0x9933dc72UL, 0x1c259377UL, 0x2b4f5176UL,
+    0x72f11774UL, 0x459bd575UL, 0x78dc897eUL, 0x4fb64b7fUL, 0x16080d7dUL,
+    0x2162cf7cUL, 0xa4748079UL, 0x931e4278UL, 0xcaa0047aUL, 0xfdcac67bUL,
+    0xb02ebc6cUL, 0x87447e6dUL, 0xdefa386fUL, 0xe990fa6eUL, 0x6c86b56bUL,
+    0x5bec776aUL, 0x02523168UL, 0x3538f369UL, 0x087faf62UL, 0x3f156d63UL,
+    0x66ab2b61UL, 0x51c1e960UL, 0xd4d7a665UL, 0xe3bd6464UL, 0xba032266UL,
+    0x8d69e067UL, 0x20cbd748UL, 0x17a11549UL, 0x4e1f534bUL, 0x7975914aUL,
+    0xfc63de4fUL, 0xcb091c4eUL, 0x92b75a4cUL, 0xa5dd984dUL, 0x989ac446UL,
+    0xaff00647UL, 0xf64e4045UL, 0xc1248244UL, 0x4432cd41UL, 0x73580f40UL,
+    0x2ae64942UL, 0x1d8c8b43UL, 0x5068f154UL, 0x67023355UL, 0x3ebc7557UL,
+    0x09d6b756UL, 0x8cc0f853UL, 0xbbaa3a52UL, 0xe2147c50UL, 0xd57ebe51UL,
+    0xe839e25aUL, 0xdf53205bUL, 0x86ed6659UL, 0xb187a458UL, 0x3491eb5dUL,
+    0x03fb295cUL, 0x5a456f5eUL, 0x6d2fad5fUL, 0x801b35e1UL, 0xb771f7e0UL,
+    0xeecfb1e2UL, 0xd9a573e3UL, 0x5cb33ce6UL, 0x6bd9fee7UL, 0x3267b8e5UL,
+    0x050d7ae4UL, 0x384a26efUL, 0x0f20e4eeUL, 0x569ea2ecUL, 0x61f460edUL,
+    0xe4e22fe8UL, 0xd388ede9UL, 0x8a36abebUL, 0xbd5c69eaUL, 0xf0b813fdUL,
+    0xc7d2d1fcUL, 0x9e6c97feUL, 0xa90655ffUL, 0x2c101afaUL, 0x1b7ad8fbUL,
+    0x42c49ef9UL, 0x75ae5cf8UL, 0x48e900f3UL, 0x7f83c2f2UL, 0x263d84f0UL,
+    0x115746f1UL, 0x944109f4UL, 0xa32bcbf5UL, 0xfa958df7UL, 0xcdff4ff6UL,
+    0x605d78d9UL, 0x5737bad8UL, 0x0e89fcdaUL, 0x39e33edbUL, 0xbcf571deUL,
+    0x8b9fb3dfUL, 0xd221f5ddUL, 0xe54b37dcUL, 0xd80c6bd7UL, 0xef66a9d6UL,
+    0xb6d8efd4UL, 0x81b22dd5UL, 0x04a462d0UL, 0x33cea0d1UL, 0x6a70e6d3UL,
+    0x5d1a24d2UL, 0x10fe5ec5UL, 0x27949cc4UL, 0x7e2adac6UL, 0x494018c7UL,
+    0xcc5657c2UL, 0xfb3c95c3UL, 0xa282d3c1UL, 0x95e811c0UL, 0xa8af4dcbUL,
+    0x9fc58fcaUL, 0xc67bc9c8UL, 0xf1110bc9UL, 0x740744ccUL, 0x436d86cdUL,
+    0x1ad3c0cfUL, 0x2db902ceUL, 0x4096af91UL, 0x77fc6d90UL, 0x2e422b92UL,
+    0x1928e993UL, 0x9c3ea696UL, 0xab546497UL, 0xf2ea2295UL, 0xc580e094UL,
+    0xf8c7bc9fUL, 0xcfad7e9eUL, 0x9613389cUL, 0xa179fa9dUL, 0x246fb598UL,
+    0x13057799UL, 0x4abb319bUL, 0x7dd1f39aUL, 0x3035898dUL, 0x075f4b8cUL,
+    0x5ee10d8eUL, 0x698bcf8fUL, 0xec9d808aUL, 0xdbf7428bUL, 0x82490489UL,
+    0xb523c688UL, 0x88649a83UL, 0xbf0e5882UL, 0xe6b01e80UL, 0xd1dadc81UL,
+    0x54cc9384UL, 0x63a65185UL, 0x3a181787UL, 0x0d72d586UL, 0xa0d0e2a9UL,
+    0x97ba20a8UL, 0xce0466aaUL, 0xf96ea4abUL, 0x7c78ebaeUL, 0x4b1229afUL,
+    0x12ac6fadUL, 0x25c6adacUL, 0x1881f1a7UL, 0x2feb33a6UL, 0x765575a4UL,
+    0x413fb7a5UL, 0xc429f8a0UL, 0xf3433aa1UL, 0xaafd7ca3UL, 0x9d97bea2UL,
+    0xd073c4b5UL, 0xe71906b4UL, 0xbea740b6UL, 0x89cd82b7UL, 0x0cdbcdb2UL,
+    0x3bb10fb3UL, 0x620f49b1UL, 0x55658bb0UL, 0x6822d7bbUL, 0x5f4815baUL,
+    0x06f653b8UL, 0x319c91b9UL, 0xb48adebcUL, 0x83e01cbdUL, 0xda5e5abfUL,
+    0xed3498beUL
+  },
+  {
+    0x00000000UL, 0x6567bcb8UL, 0x8bc809aaUL, 0xeeafb512UL, 0x5797628fUL,
+    0x32f0de37UL, 0xdc5f6b25UL, 0xb938d79dUL, 0xef28b4c5UL, 0x8a4f087dUL,
+    0x64e0bd6fUL, 0x018701d7UL, 0xb8bfd64aUL, 0xddd86af2UL, 0x3377dfe0UL,
+    0x56106358UL, 0x9f571950UL, 0xfa30a5e8UL, 0x149f10faUL, 0x71f8ac42UL,
+    0xc8c07bdfUL, 0xada7c767UL, 0x43087275UL, 0x266fcecdUL, 0x707fad95UL,
+    0x1518112dUL, 0xfbb7a43fUL, 0x9ed01887UL, 0x27e8cf1aUL, 0x428f73a2UL,
+    0xac20c6b0UL, 0xc9477a08UL, 0x3eaf32a0UL, 0x5bc88e18UL, 0xb5673b0aUL,
+    0xd00087b2UL, 0x6938502fUL, 0x0c5fec97UL, 0xe2f05985UL, 0x8797e53dUL,
+    0xd1878665UL, 0xb4e03addUL, 0x5a4f8fcfUL, 0x3f283377UL, 0x8610e4eaUL,
+    0xe3775852UL, 0x0dd8ed40UL, 0x68bf51f8UL, 0xa1f82bf0UL, 0xc49f9748UL,
+    0x2a30225aUL, 0x4f579ee2UL, 0xf66f497fUL, 0x9308f5c7UL, 0x7da740d5UL,
+    0x18c0fc6dUL, 0x4ed09f35UL, 0x2bb7238dUL, 0xc518969fUL, 0xa07f2a27UL,
+    0x1947fdbaUL, 0x7c204102UL, 0x928ff410UL, 0xf7e848a8UL, 0x3d58149bUL,
+    0x583fa823UL, 0xb6901d31UL, 0xd3f7a189UL, 0x6acf7614UL, 0x0fa8caacUL,
+    0xe1077fbeUL, 0x8460c306UL, 0xd270a05eUL, 0xb7171ce6UL, 0x59b8a9f4UL,
+    0x3cdf154cUL, 0x85e7c2d1UL, 0xe0807e69UL, 0x0e2fcb7bUL, 0x6b4877c3UL,
+    0xa20f0dcbUL, 0xc768b173UL, 0x29c70461UL, 0x4ca0b8d9UL, 0xf5986f44UL,
+    0x90ffd3fcUL, 0x7e5066eeUL, 0x1b37da56UL, 0x4d27b90eUL, 0x284005b6UL,
+    0xc6efb0a4UL, 0xa3880c1cUL, 0x1ab0db81UL, 0x7fd76739UL, 0x9178d22bUL,
+    0xf41f6e93UL, 0x03f7263bUL, 0x66909a83UL, 0x883f2f91UL, 0xed589329UL,
+    0x546044b4UL, 0x3107f80cUL, 0xdfa84d1eUL, 0xbacff1a6UL, 0xecdf92feUL,
+    0x89b82e46UL, 0x67179b54UL, 0x027027ecUL, 0xbb48f071UL, 0xde2f4cc9UL,
+    0x3080f9dbUL, 0x55e74563UL, 0x9ca03f6bUL, 0xf9c783d3UL, 0x176836c1UL,
+    0x720f8a79UL, 0xcb375de4UL, 0xae50e15cUL, 0x40ff544eUL, 0x2598e8f6UL,
+    0x73888baeUL, 0x16ef3716UL, 0xf8408204UL, 0x9d273ebcUL, 0x241fe921UL,
+    0x41785599UL, 0xafd7e08bUL, 0xcab05c33UL, 0x3bb659edUL, 0x5ed1e555UL,
+    0xb07e5047UL, 0xd519ecffUL, 0x6c213b62UL, 0x094687daUL, 0xe7e932c8UL,
+    0x828e8e70UL, 0xd49eed28UL, 0xb1f95190UL, 0x5f56e482UL, 0x3a31583aUL,
+    0x83098fa7UL, 0xe66e331fUL, 0x08c1860dUL, 0x6da63ab5UL, 0xa4e140bdUL,
+    0xc186fc05UL, 0x2f294917UL, 0x4a4ef5afUL, 0xf3762232UL, 0x96119e8aUL,
+    0x78be2b98UL, 0x1dd99720UL, 0x4bc9f478UL, 0x2eae48c0UL, 0xc001fdd2UL,
+    0xa566416aUL, 0x1c5e96f7UL, 0x79392a4fUL, 0x97969f5dUL, 0xf2f123e5UL,
+    0x05196b4dUL, 0x607ed7f5UL, 0x8ed162e7UL, 0xebb6de5fUL, 0x528e09c2UL,
+    0x37e9b57aUL, 0xd9460068UL, 0xbc21bcd0UL, 0xea31df88UL, 0x8f566330UL,
+    0x61f9d622UL, 0x049e6a9aUL, 0xbda6bd07UL, 0xd8c101bfUL, 0x366eb4adUL,
+    0x53090815UL, 0x9a4e721dUL, 0xff29cea5UL, 0x11867bb7UL, 0x74e1c70fUL,
+    0xcdd91092UL, 0xa8beac2aUL, 0x46111938UL, 0x2376a580UL, 0x7566c6d8UL,
+    0x10017a60UL, 0xfeaecf72UL, 0x9bc973caUL, 0x22f1a457UL, 0x479618efUL,
+    0xa939adfdUL, 0xcc5e1145UL, 0x06ee4d76UL, 0x6389f1ceUL, 0x8d2644dcUL,
+    0xe841f864UL, 0x51792ff9UL, 0x341e9341UL, 0xdab12653UL, 0xbfd69aebUL,
+    0xe9c6f9b3UL, 0x8ca1450bUL, 0x620ef019UL, 0x07694ca1UL, 0xbe519b3cUL,
+    0xdb362784UL, 0x35999296UL, 0x50fe2e2eUL, 0x99b95426UL, 0xfcdee89eUL,
+    0x12715d8cUL, 0x7716e134UL, 0xce2e36a9UL, 0xab498a11UL, 0x45e63f03UL,
+    0x208183bbUL, 0x7691e0e3UL, 0x13f65c5bUL, 0xfd59e949UL, 0x983e55f1UL,
+    0x2106826cUL, 0x44613ed4UL, 0xaace8bc6UL, 0xcfa9377eUL, 0x38417fd6UL,
+    0x5d26c36eUL, 0xb389767cUL, 0xd6eecac4UL, 0x6fd61d59UL, 0x0ab1a1e1UL,
+    0xe41e14f3UL, 0x8179a84bUL, 0xd769cb13UL, 0xb20e77abUL, 0x5ca1c2b9UL,
+    0x39c67e01UL, 0x80fea99cUL, 0xe5991524UL, 0x0b36a036UL, 0x6e511c8eUL,
+    0xa7166686UL, 0xc271da3eUL, 0x2cde6f2cUL, 0x49b9d394UL, 0xf0810409UL,
+    0x95e6b8b1UL, 0x7b490da3UL, 0x1e2eb11bUL, 0x483ed243UL, 0x2d596efbUL,
+    0xc3f6dbe9UL, 0xa6916751UL, 0x1fa9b0ccUL, 0x7ace0c74UL, 0x9461b966UL,
+    0xf10605deUL
+#endif
+  }
+};

vendor/libgit2-sys/libgit2/deps/zlib/deflate.c

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/deflate.c b/vendor/libgit2-sys/libgit2/deps/zlib/deflate.c
new file mode 100644
index 0000000..1ec7614
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/deflate.c
@@ -0,0 +1,2163 @@
+/* deflate.c -- compress data using the deflation algorithm
+ * Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/*
+ *  ALGORITHM
+ *
+ *      The "deflation" process depends on being able to identify portions
+ *      of the input text which are identical to earlier input (within a
+ *      sliding window trailing behind the input currently being processed).
+ *
+ *      The most straightforward technique turns out to be the fastest for
+ *      most input files: try all possible matches and select the longest.
+ *      The key feature of this algorithm is that insertions into the string
+ *      dictionary are very simple and thus fast, and deletions are avoided
+ *      completely. Insertions are performed at each input character, whereas
+ *      string matches are performed only when the previous match ends. So it
+ *      is preferable to spend more time in matches to allow very fast string
+ *      insertions and avoid deletions. The matching algorithm for small
+ *      strings is inspired from that of Rabin & Karp. A brute force approach
+ *      is used to find longer strings when a small match has been found.
+ *      A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
+ *      (by Leonid Broukhis).
+ *         A previous version of this file used a more sophisticated algorithm
+ *      (by Fiala and Greene) which is guaranteed to run in linear amortized
+ *      time, but has a larger average cost, uses more memory and is patented.
+ *      However the F&G algorithm may be faster for some highly redundant
+ *      files if the parameter max_chain_length (described below) is too large.
+ *
+ *  ACKNOWLEDGEMENTS
+ *
+ *      The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
+ *      I found it in 'freeze' written by Leonid Broukhis.
+ *      Thanks to many people for bug reports and testing.
+ *
+ *  REFERENCES
+ *
+ *      Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
+ *      Available in http://tools.ietf.org/html/rfc1951
+ *
+ *      A description of the Rabin and Karp algorithm is given in the book
+ *         "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
+ *
+ *      Fiala,E.R., and Greene,D.H.
+ *         Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
+ *
+ */
+
+/* @(#) $Id$ */
+
+#include "deflate.h"
+
+const char deflate_copyright[] =
+   " deflate 1.2.11 Copyright 1995-2017 Jean-loup Gailly and Mark Adler ";
+/*
+  If you use the zlib library in a product, an acknowledgment is welcome
+  in the documentation of your product. If for some reason you cannot
+  include such an acknowledgment, I would appreciate that you keep this
+  copyright string in the executable of your product.
+ */
+
+/* ===========================================================================
+ *  Function prototypes.
+ */
+typedef enum {
+    need_more,      /* block not completed, need more input or more output */
+    block_done,     /* block flush performed */
+    finish_started, /* finish started, need only more output at next deflate */
+    finish_done     /* finish done, accept no more input or output */
+} block_state;
+
+typedef block_state (*compress_func) OF((deflate_state *s, int flush));
+/* Compression function. Returns the block state after the call. */
+
+local int deflateStateCheck      OF((z_streamp strm));
+local void slide_hash     OF((deflate_state *s));
+local void fill_window    OF((deflate_state *s));
+local block_state deflate_stored OF((deflate_state *s, int flush));
+local block_state deflate_fast   OF((deflate_state *s, int flush));
+#ifndef FASTEST
+local block_state deflate_slow   OF((deflate_state *s, int flush));
+#endif
+local block_state deflate_rle    OF((deflate_state *s, int flush));
+local block_state deflate_huff   OF((deflate_state *s, int flush));
+local void lm_init        OF((deflate_state *s));
+local void putShortMSB    OF((deflate_state *s, uInt b));
+local void flush_pending  OF((z_streamp strm));
+local unsigned read_buf   OF((z_streamp strm, Bytef *buf, unsigned size));
+#ifdef ASMV
+#  pragma message("Assembler code may have bugs -- use at your own risk")
+      void match_init OF((void)); /* asm code initialization */
+      uInt longest_match  OF((deflate_state *s, IPos cur_match));
+#else
+local uInt longest_match  OF((deflate_state *s, IPos cur_match));
+#endif
+
+#ifdef ZLIB_DEBUG
+local  void check_match OF((deflate_state *s, IPos start, IPos match,
+                            int length));
+#endif
+
+/* ===========================================================================
+ * Local data
+ */
+
+#define NIL 0
+/* Tail of hash chains */
+
+#ifndef TOO_FAR
+#  define TOO_FAR 4096
+#endif
+/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
+
+/* Values for max_lazy_match, good_match and max_chain_length, depending on
+ * the desired pack level (0..9). The values given below have been tuned to
+ * exclude worst case performance for pathological files. Better values may be
+ * found for specific files.
+ */
+typedef struct config_s {
+   ush good_length; /* reduce lazy search above this match length */
+   ush max_lazy;    /* do not perform lazy search above this match length */
+   ush nice_length; /* quit search above this match length */
+   ush max_chain;
+   compress_func func;
+} config;
+
+#ifdef FASTEST
+local const config configuration_table[2] = {
+/*      good lazy nice chain */
+/* 0 */ {0,    0,  0,    0, deflate_stored},  /* store only */
+/* 1 */ {4,    4,  8,    4, deflate_fast}}; /* max speed, no lazy matches */
+#else
+local const config configuration_table[10] = {
+/*      good lazy nice chain */
+/* 0 */ {0,    0,  0,    0, deflate_stored},  /* store only */
+/* 1 */ {4,    4,  8,    4, deflate_fast}, /* max speed, no lazy matches */
+/* 2 */ {4,    5, 16,    8, deflate_fast},
+/* 3 */ {4,    6, 32,   32, deflate_fast},
+
+/* 4 */ {4,    4, 16,   16, deflate_slow},  /* lazy matches */
+/* 5 */ {8,   16, 32,   32, deflate_slow},
+/* 6 */ {8,   16, 128, 128, deflate_slow},
+/* 7 */ {8,   32, 128, 256, deflate_slow},
+/* 8 */ {32, 128, 258, 1024, deflate_slow},
+/* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* max compression */
+#endif
+
+/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
+ * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
+ * meaning.
+ */
+
+/* rank Z_BLOCK between Z_NO_FLUSH and Z_PARTIAL_FLUSH */
+#define RANK(f) (((f) * 2) - ((f) > 4 ? 9 : 0))
+
+/* ===========================================================================
+ * Update a hash value with the given input byte
+ * IN  assertion: all calls to UPDATE_HASH are made with consecutive input
+ *    characters, so that a running hash key can be computed from the previous
+ *    key instead of complete recalculation each time.
+ */
+#define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
+
+
+/* ===========================================================================
+ * Insert string str in the dictionary and set match_head to the previous head
+ * of the hash chain (the most recent string with same hash key). Return
+ * the previous length of the hash chain.
+ * If this file is compiled with -DFASTEST, the compression level is forced
+ * to 1, and no hash chains are maintained.
+ * IN  assertion: all calls to INSERT_STRING are made with consecutive input
+ *    characters and the first MIN_MATCH bytes of str are valid (except for
+ *    the last MIN_MATCH-1 bytes of the input file).
+ */
+#ifdef FASTEST
+#define INSERT_STRING(s, str, match_head) \
+   (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
+    match_head = s->head[s->ins_h], \
+    s->head[s->ins_h] = (Pos)(str))
+#else
+#define INSERT_STRING(s, str, match_head) \
+   (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
+    match_head = s->prev[(str) & s->w_mask] = s->head[s->ins_h], \
+    s->head[s->ins_h] = (Pos)(str))
+#endif
+
+/* ===========================================================================
+ * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
+ * prev[] will be initialized on the fly.
+ */
+#define CLEAR_HASH(s) \
+    s->head[s->hash_size-1] = NIL; \
+    zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
+
+/* ===========================================================================
+ * Slide the hash table when sliding the window down (could be avoided with 32
+ * bit values at the expense of memory usage). We slide even when level == 0 to
+ * keep the hash table consistent if we switch back to level > 0 later.
+ */
+local void slide_hash(s)
+    deflate_state *s;
+{
+    unsigned n, m;
+    Posf *p;
+    uInt wsize = s->w_size;
+
+    n = s->hash_size;
+    p = &s->head[n];
+    do {
+        m = *--p;
+        *p = (Pos)(m >= wsize ? m - wsize : NIL);
+    } while (--n);
+    n = wsize;
+#ifndef FASTEST
+    p = &s->prev[n];
+    do {
+        m = *--p;
+        *p = (Pos)(m >= wsize ? m - wsize : NIL);
+        /* If n is not on any hash chain, prev[n] is garbage but
+         * its value will never be used.
+         */
+    } while (--n);
+#endif
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateInit_(strm, level, version, stream_size)
+    z_streamp strm;
+    int level;
+    const char *version;
+    int stream_size;
+{
+    return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
+                         Z_DEFAULT_STRATEGY, version, stream_size);
+    /* To do: ignore strm->next_in if we use it as window */
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
+                  version, stream_size)
+    z_streamp strm;
+    int  level;
+    int  method;
+    int  windowBits;
+    int  memLevel;
+    int  strategy;
+    const char *version;
+    int stream_size;
+{
+    deflate_state *s;
+    int wrap = 1;
+    static const char my_version[] = ZLIB_VERSION;
+
+    ushf *overlay;
+    /* We overlay pending_buf and d_buf+l_buf. This works since the average
+     * output size for (length,distance) codes is <= 24 bits.
+     */
+
+    if (version == Z_NULL || version[0] != my_version[0] ||
+        stream_size != sizeof(z_stream)) {
+        return Z_VERSION_ERROR;
+    }
+    if (strm == Z_NULL) return Z_STREAM_ERROR;
+
+    strm->msg = Z_NULL;
+    if (strm->zalloc == (alloc_func)0) {
+#ifdef Z_SOLO
+        return Z_STREAM_ERROR;
+#else
+        strm->zalloc = zcalloc;
+        strm->opaque = (voidpf)0;
+#endif
+    }
+    if (strm->zfree == (free_func)0)
+#ifdef Z_SOLO
+        return Z_STREAM_ERROR;
+#else
+        strm->zfree = zcfree;
+#endif
+
+#ifdef FASTEST
+    if (level != 0) level = 1;
+#else
+    if (level == Z_DEFAULT_COMPRESSION) level = 6;
+#endif
+
+    if (windowBits < 0) { /* suppress zlib wrapper */
+        wrap = 0;
+        windowBits = -windowBits;
+    }
+#ifdef GZIP
+    else if (windowBits > 15) {
+        wrap = 2;       /* write gzip wrapper instead */
+        windowBits -= 16;
+    }
+#endif
+    if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
+        windowBits < 8 || windowBits > 15 || level < 0 || level > 9 ||
+        strategy < 0 || strategy > Z_FIXED || (windowBits == 8 && wrap != 1)) {
+        return Z_STREAM_ERROR;
+    }
+    if (windowBits == 8) windowBits = 9;  /* until 256-byte window bug fixed */
+    s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
+    if (s == Z_NULL) return Z_MEM_ERROR;
+    strm->state = (struct internal_state FAR *)s;
+    s->strm = strm;
+    s->status = INIT_STATE;     /* to pass state test in deflateReset() */
+
+    s->wrap = wrap;
+    s->gzhead = Z_NULL;
+    s->w_bits = (uInt)windowBits;
+    s->w_size = 1 << s->w_bits;
+    s->w_mask = s->w_size - 1;
+
+    s->hash_bits = (uInt)memLevel + 7;
+    s->hash_size = 1 << s->hash_bits;
+    s->hash_mask = s->hash_size - 1;
+    s->hash_shift =  ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
+
+    s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
+    s->prev   = (Posf *)  ZALLOC(strm, s->w_size, sizeof(Pos));
+    s->head   = (Posf *)  ZALLOC(strm, s->hash_size, sizeof(Pos));
+
+    s->high_water = 0;      /* nothing written to s->window yet */
+
+    s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
+
+    overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
+    s->pending_buf = (uchf *) overlay;
+    s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
+
+    if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
+        s->pending_buf == Z_NULL) {
+        s->status = FINISH_STATE;
+        strm->msg = ERR_MSG(Z_MEM_ERROR);
+        deflateEnd (strm);
+        return Z_MEM_ERROR;
+    }
+    s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
+    s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
+
+    s->level = level;
+    s->strategy = strategy;
+    s->method = (Byte)method;
+
+    return deflateReset(strm);
+}
+
+/* =========================================================================
+ * Check for a valid deflate stream state. Return 0 if ok, 1 if not.
+ */
+local int deflateStateCheck (strm)
+    z_streamp strm;
+{
+    deflate_state *s;
+    if (strm == Z_NULL ||
+        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
+        return 1;
+    s = strm->state;
+    if (s == Z_NULL || s->strm != strm || (s->status != INIT_STATE &&
+#ifdef GZIP
+                                           s->status != GZIP_STATE &&
+#endif
+                                           s->status != EXTRA_STATE &&
+                                           s->status != NAME_STATE &&
+                                           s->status != COMMENT_STATE &&
+                                           s->status != HCRC_STATE &&
+                                           s->status != BUSY_STATE &&
+                                           s->status != FINISH_STATE))
+        return 1;
+    return 0;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength)
+    z_streamp strm;
+    const Bytef *dictionary;
+    uInt  dictLength;
+{
+    deflate_state *s;
+    uInt str, n;
+    int wrap;
+    unsigned avail;
+    z_const unsigned char *next;
+
+    if (deflateStateCheck(strm) || dictionary == Z_NULL)
+        return Z_STREAM_ERROR;
+    s = strm->state;
+    wrap = s->wrap;
+    if (wrap == 2 || (wrap == 1 && s->status != INIT_STATE) || s->lookahead)
+        return Z_STREAM_ERROR;
+
+    /* when using zlib wrappers, compute Adler-32 for provided dictionary */
+    if (wrap == 1)
+        strm->adler = adler32(strm->adler, dictionary, dictLength);
+    s->wrap = 0;                    /* avoid computing Adler-32 in read_buf */
+
+    /* if dictionary would fill window, just replace the history */
+    if (dictLength >= s->w_size) {
+        if (wrap == 0) {            /* already empty otherwise */
+            CLEAR_HASH(s);
+            s->strstart = 0;
+            s->block_start = 0L;
+            s->insert = 0;
+        }
+        dictionary += dictLength - s->w_size;  /* use the tail */
+        dictLength = s->w_size;
+    }
+
+    /* insert dictionary into window and hash */
+    avail = strm->avail_in;
+    next = strm->next_in;
+    strm->avail_in = dictLength;
+    strm->next_in = (z_const Bytef *)dictionary;
+    fill_window(s);
+    while (s->lookahead >= MIN_MATCH) {
+        str = s->strstart;
+        n = s->lookahead - (MIN_MATCH-1);
+        do {
+            UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]);
+#ifndef FASTEST
+            s->prev[str & s->w_mask] = s->head[s->ins_h];
+#endif
+            s->head[s->ins_h] = (Pos)str;
+            str++;
+        } while (--n);
+        s->strstart = str;
+        s->lookahead = MIN_MATCH-1;
+        fill_window(s);
+    }
+    s->strstart += s->lookahead;
+    s->block_start = (long)s->strstart;
+    s->insert = s->lookahead;
+    s->lookahead = 0;
+    s->match_length = s->prev_length = MIN_MATCH-1;
+    s->match_available = 0;
+    strm->next_in = next;
+    strm->avail_in = avail;
+    s->wrap = wrap;
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateGetDictionary (strm, dictionary, dictLength)
+    z_streamp strm;
+    Bytef *dictionary;
+    uInt  *dictLength;
+{
+    deflate_state *s;
+    uInt len;
+
+    if (deflateStateCheck(strm))
+        return Z_STREAM_ERROR;
+    s = strm->state;
+    len = s->strstart + s->lookahead;
+    if (len > s->w_size)
+        len = s->w_size;
+    if (dictionary != Z_NULL && len)
+        zmemcpy(dictionary, s->window + s->strstart + s->lookahead - len, len);
+    if (dictLength != Z_NULL)
+        *dictLength = len;
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateResetKeep (strm)
+    z_streamp strm;
+{
+    deflate_state *s;
+
+    if (deflateStateCheck(strm)) {
+        return Z_STREAM_ERROR;
+    }
+
+    strm->total_in = strm->total_out = 0;
+    strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
+    strm->data_type = Z_UNKNOWN;
+
+    s = (deflate_state *)strm->state;
+    s->pending = 0;
+    s->pending_out = s->pending_buf;
+
+    if (s->wrap < 0) {
+        s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */
+    }
+    s->status =
+#ifdef GZIP
+        s->wrap == 2 ? GZIP_STATE :
+#endif
+        s->wrap ? INIT_STATE : BUSY_STATE;
+    strm->adler =
+#ifdef GZIP
+        s->wrap == 2 ? crc32(0L, Z_NULL, 0) :
+#endif
+        adler32(0L, Z_NULL, 0);
+    s->last_flush = Z_NO_FLUSH;
+
+    _tr_init(s);
+
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateReset (strm)
+    z_streamp strm;
+{
+    int ret;
+
+    ret = deflateResetKeep(strm);
+    if (ret == Z_OK)
+        lm_init(strm->state);
+    return ret;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateSetHeader (strm, head)
+    z_streamp strm;
+    gz_headerp head;
+{
+    if (deflateStateCheck(strm) || strm->state->wrap != 2)
+        return Z_STREAM_ERROR;
+    strm->state->gzhead = head;
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflatePending (strm, pending, bits)
+    unsigned *pending;
+    int *bits;
+    z_streamp strm;
+{
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
+    if (pending != Z_NULL)
+        *pending = strm->state->pending;
+    if (bits != Z_NULL)
+        *bits = strm->state->bi_valid;
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflatePrime (strm, bits, value)
+    z_streamp strm;
+    int bits;
+    int value;
+{
+    deflate_state *s;
+    int put;
+
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
+    s = strm->state;
+    if ((Bytef *)(s->d_buf) < s->pending_out + ((Buf_size + 7) >> 3))
+        return Z_BUF_ERROR;
+    do {
+        put = Buf_size - s->bi_valid;
+        if (put > bits)
+            put = bits;
+        s->bi_buf |= (ush)((value & ((1 << put) - 1)) << s->bi_valid);
+        s->bi_valid += put;
+        _tr_flush_bits(s);
+        value >>= put;
+        bits -= put;
+    } while (bits);
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateParams(strm, level, strategy)
+    z_streamp strm;
+    int level;
+    int strategy;
+{
+    deflate_state *s;
+    compress_func func;
+
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
+    s = strm->state;
+
+#ifdef FASTEST
+    if (level != 0) level = 1;
+#else
+    if (level == Z_DEFAULT_COMPRESSION) level = 6;
+#endif
+    if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) {
+        return Z_STREAM_ERROR;
+    }
+    func = configuration_table[s->level].func;
+
+    if ((strategy != s->strategy || func != configuration_table[level].func) &&
+        s->high_water) {
+        /* Flush the last buffer: */
+        int err = deflate(strm, Z_BLOCK);
+        if (err == Z_STREAM_ERROR)
+            return err;
+        if (strm->avail_out == 0)
+            return Z_BUF_ERROR;
+    }
+    if (s->level != level) {
+        if (s->level == 0 && s->matches != 0) {
+            if (s->matches == 1)
+                slide_hash(s);
+            else
+                CLEAR_HASH(s);
+            s->matches = 0;
+        }
+        s->level = level;
+        s->max_lazy_match   = configuration_table[level].max_lazy;
+        s->good_match       = configuration_table[level].good_length;
+        s->nice_match       = configuration_table[level].nice_length;
+        s->max_chain_length = configuration_table[level].max_chain;
+    }
+    s->strategy = strategy;
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateTune(strm, good_length, max_lazy, nice_length, max_chain)
+    z_streamp strm;
+    int good_length;
+    int max_lazy;
+    int nice_length;
+    int max_chain;
+{
+    deflate_state *s;
+
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
+    s = strm->state;
+    s->good_match = (uInt)good_length;
+    s->max_lazy_match = (uInt)max_lazy;
+    s->nice_match = nice_length;
+    s->max_chain_length = (uInt)max_chain;
+    return Z_OK;
+}
+
+/* =========================================================================
+ * For the default windowBits of 15 and memLevel of 8, this function returns
+ * a close to exact, as well as small, upper bound on the compressed size.
+ * They are coded as constants here for a reason--if the #define's are
+ * changed, then this function needs to be changed as well.  The return
+ * value for 15 and 8 only works for those exact settings.
+ *
+ * For any setting other than those defaults for windowBits and memLevel,
+ * the value returned is a conservative worst case for the maximum expansion
+ * resulting from using fixed blocks instead of stored blocks, which deflate
+ * can emit on compressed data for some combinations of the parameters.
+ *
+ * This function could be more sophisticated to provide closer upper bounds for
+ * every combination of windowBits and memLevel.  But even the conservative
+ * upper bound of about 14% expansion does not seem onerous for output buffer
+ * allocation.
+ */
+uLong ZEXPORT deflateBound(strm, sourceLen)
+    z_streamp strm;
+    uLong sourceLen;
+{
+    deflate_state *s;
+    uLong complen, wraplen;
+
+    /* conservative upper bound for compressed data */
+    complen = sourceLen +
+              ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5;
+
+    /* if can't get parameters, return conservative bound plus zlib wrapper */
+    if (deflateStateCheck(strm))
+        return complen + 6;
+
+    /* compute wrapper length */
+    s = strm->state;
+    switch (s->wrap) {
+    case 0:                                 /* raw deflate */
+        wraplen = 0;
+        break;
+    case 1:                                 /* zlib wrapper */
+        wraplen = 6 + (s->strstart ? 4 : 0);
+        break;
+#ifdef GZIP
+    case 2:                                 /* gzip wrapper */
+        wraplen = 18;
+        if (s->gzhead != Z_NULL) {          /* user-supplied gzip header */
+            Bytef *str;
+            if (s->gzhead->extra != Z_NULL)
+                wraplen += 2 + s->gzhead->extra_len;
+            str = s->gzhead->name;
+            if (str != Z_NULL)
+                do {
+                    wraplen++;
+                } while (*str++);
+            str = s->gzhead->comment;
+            if (str != Z_NULL)
+                do {
+                    wraplen++;
+                } while (*str++);
+            if (s->gzhead->hcrc)
+                wraplen += 2;
+        }
+        break;
+#endif
+    default:                                /* for compiler happiness */
+        wraplen = 6;
+    }
+
+    /* if not default parameters, return conservative bound */
+    if (s->w_bits != 15 || s->hash_bits != 8 + 7)
+        return complen + wraplen;
+
+    /* default settings: return tight bound for that case */
+    return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +
+           (sourceLen >> 25) + 13 - 6 + wraplen;
+}
+
+/* =========================================================================
+ * Put a short in the pending buffer. The 16-bit value is put in MSB order.
+ * IN assertion: the stream state is correct and there is enough room in
+ * pending_buf.
+ */
+local void putShortMSB (s, b)
+    deflate_state *s;
+    uInt b;
+{
+    put_byte(s, (Byte)(b >> 8));
+    put_byte(s, (Byte)(b & 0xff));
+}
+
+/* =========================================================================
+ * Flush as much pending output as possible. All deflate() output, except for
+ * some deflate_stored() output, goes through this function so some
+ * applications may wish to modify it to avoid allocating a large
+ * strm->next_out buffer and copying into it. (See also read_buf()).
+ */
+local void flush_pending(strm)
+    z_streamp strm;
+{
+    unsigned len;
+    deflate_state *s = strm->state;
+
+    _tr_flush_bits(s);
+    len = s->pending;
+    if (len > strm->avail_out) len = strm->avail_out;
+    if (len == 0) return;
+
+    zmemcpy(strm->next_out, s->pending_out, len);
+    strm->next_out  += len;
+    s->pending_out  += len;
+    strm->total_out += len;
+    strm->avail_out -= len;
+    s->pending      -= len;
+    if (s->pending == 0) {
+        s->pending_out = s->pending_buf;
+    }
+}
+
+/* ===========================================================================
+ * Update the header CRC with the bytes s->pending_buf[beg..s->pending - 1].
+ */
+#define HCRC_UPDATE(beg) \
+    do { \
+        if (s->gzhead->hcrc && s->pending > (beg)) \
+            strm->adler = crc32(strm->adler, s->pending_buf + (beg), \
+                                s->pending - (beg)); \
+    } while (0)
+
+/* ========================================================================= */
+int ZEXPORT deflate (strm, flush)
+    z_streamp strm;
+    int flush;
+{
+    int old_flush; /* value of flush param for previous deflate call */
+    deflate_state *s;
+
+    if (deflateStateCheck(strm) || flush > Z_BLOCK || flush < 0) {
+        return Z_STREAM_ERROR;
+    }
+    s = strm->state;
+
+    if (strm->next_out == Z_NULL ||
+        (strm->avail_in != 0 && strm->next_in == Z_NULL) ||
+        (s->status == FINISH_STATE && flush != Z_FINISH)) {
+        ERR_RETURN(strm, Z_STREAM_ERROR);
+    }
+    if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
+
+    old_flush = s->last_flush;
+    s->last_flush = flush;
+
+    /* Flush as much pending output as possible */
+    if (s->pending != 0) {
+        flush_pending(strm);
+        if (strm->avail_out == 0) {
+            /* Since avail_out is 0, deflate will be called again with
+             * more output space, but possibly with both pending and
+             * avail_in equal to zero. There won't be anything to do,
+             * but this is not an error situation so make sure we
+             * return OK instead of BUF_ERROR at next call of deflate:
+             */
+            s->last_flush = -1;
+            return Z_OK;
+        }
+
+    /* Make sure there is something to do and avoid duplicate consecutive
+     * flushes. For repeated and useless calls with Z_FINISH, we keep
+     * returning Z_STREAM_END instead of Z_BUF_ERROR.
+     */
+    } else if (strm->avail_in == 0 && RANK(flush) <= RANK(old_flush) &&
+               flush != Z_FINISH) {
+        ERR_RETURN(strm, Z_BUF_ERROR);
+    }
+
+    /* User must not provide more input after the first FINISH: */
+    if (s->status == FINISH_STATE && strm->avail_in != 0) {
+        ERR_RETURN(strm, Z_BUF_ERROR);
+    }
+
+    /* Write the header */
+    if (s->status == INIT_STATE) {
+        /* zlib header */
+        uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
+        uInt level_flags;
+
+        if (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2)
+            level_flags = 0;
+        else if (s->level < 6)
+            level_flags = 1;
+        else if (s->level == 6)
+            level_flags = 2;
+        else
+            level_flags = 3;
+        header |= (level_flags << 6);
+        if (s->strstart != 0) header |= PRESET_DICT;
+        header += 31 - (header % 31);
+
+        putShortMSB(s, header);
+
+        /* Save the adler32 of the preset dictionary: */
+        if (s->strstart != 0) {
+            putShortMSB(s, (uInt)(strm->adler >> 16));
+            putShortMSB(s, (uInt)(strm->adler & 0xffff));
+        }
+        strm->adler = adler32(0L, Z_NULL, 0);
+        s->status = BUSY_STATE;
+
+        /* Compression must start with an empty pending buffer */
+        flush_pending(strm);
+        if (s->pending != 0) {
+            s->last_flush = -1;
+            return Z_OK;
+        }
+    }
+#ifdef GZIP
+    if (s->status == GZIP_STATE) {
+        /* gzip header */
+        strm->adler = crc32(0L, Z_NULL, 0);
+        put_byte(s, 31);
+        put_byte(s, 139);
+        put_byte(s, 8);
+        if (s->gzhead == Z_NULL) {
+            put_byte(s, 0);
+            put_byte(s, 0);
+            put_byte(s, 0);
+            put_byte(s, 0);
+            put_byte(s, 0);
+            put_byte(s, s->level == 9 ? 2 :
+                     (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
+                      4 : 0));
+            put_byte(s, OS_CODE);
+            s->status = BUSY_STATE;
+
+            /* Compression must start with an empty pending buffer */
+            flush_pending(strm);
+            if (s->pending != 0) {
+                s->last_flush = -1;
+                return Z_OK;
+            }
+        }
+        else {
+            put_byte(s, (s->gzhead->text ? 1 : 0) +
+                     (s->gzhead->hcrc ? 2 : 0) +
+                     (s->gzhead->extra == Z_NULL ? 0 : 4) +
+                     (s->gzhead->name == Z_NULL ? 0 : 8) +
+                     (s->gzhead->comment == Z_NULL ? 0 : 16)
+                     );
+            put_byte(s, (Byte)(s->gzhead->time & 0xff));
+            put_byte(s, (Byte)((s->gzhead->time >> 8) & 0xff));
+            put_byte(s, (Byte)((s->gzhead->time >> 16) & 0xff));
+            put_byte(s, (Byte)((s->gzhead->time >> 24) & 0xff));
+            put_byte(s, s->level == 9 ? 2 :
+                     (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
+                      4 : 0));
+            put_byte(s, s->gzhead->os & 0xff);
+            if (s->gzhead->extra != Z_NULL) {
+                put_byte(s, s->gzhead->extra_len & 0xff);
+                put_byte(s, (s->gzhead->extra_len >> 8) & 0xff);
+            }
+            if (s->gzhead->hcrc)
+                strm->adler = crc32(strm->adler, s->pending_buf,
+                                    s->pending);
+            s->gzindex = 0;
+            s->status = EXTRA_STATE;
+        }
+    }
+    if (s->status == EXTRA_STATE) {
+        if (s->gzhead->extra != Z_NULL) {
+            ulg beg = s->pending;   /* start of bytes to update crc */
+            uInt left = (s->gzhead->extra_len & 0xffff) - s->gzindex;
+            while (s->pending + left > s->pending_buf_size) {
+                uInt copy = s->pending_buf_size - s->pending;
+                zmemcpy(s->pending_buf + s->pending,
+                        s->gzhead->extra + s->gzindex, copy);
+                s->pending = s->pending_buf_size;
+                HCRC_UPDATE(beg);
+                s->gzindex += copy;
+                flush_pending(strm);
+                if (s->pending != 0) {
+                    s->last_flush = -1;
+                    return Z_OK;
+                }
+                beg = 0;
+                left -= copy;
+            }
+            zmemcpy(s->pending_buf + s->pending,
+                    s->gzhead->extra + s->gzindex, left);
+            s->pending += left;
+            HCRC_UPDATE(beg);
+            s->gzindex = 0;
+        }
+        s->status = NAME_STATE;
+    }
+    if (s->status == NAME_STATE) {
+        if (s->gzhead->name != Z_NULL) {
+            ulg beg = s->pending;   /* start of bytes to update crc */
+            int val;
+            do {
+                if (s->pending == s->pending_buf_size) {
+                    HCRC_UPDATE(beg);
+                    flush_pending(strm);
+                    if (s->pending != 0) {
+                        s->last_flush = -1;
+                        return Z_OK;
+                    }
+                    beg = 0;
+                }
+                val = s->gzhead->name[s->gzindex++];
+                put_byte(s, val);
+            } while (val != 0);
+            HCRC_UPDATE(beg);
+            s->gzindex = 0;
+        }
+        s->status = COMMENT_STATE;
+    }
+    if (s->status == COMMENT_STATE) {
+        if (s->gzhead->comment != Z_NULL) {
+            ulg beg = s->pending;   /* start of bytes to update crc */
+            int val;
+            do {
+                if (s->pending == s->pending_buf_size) {
+                    HCRC_UPDATE(beg);
+                    flush_pending(strm);
+                    if (s->pending != 0) {
+                        s->last_flush = -1;
+                        return Z_OK;
+                    }
+                    beg = 0;
+                }
+                val = s->gzhead->comment[s->gzindex++];
+                put_byte(s, val);
+            } while (val != 0);
+            HCRC_UPDATE(beg);
+        }
+        s->status = HCRC_STATE;
+    }
+    if (s->status == HCRC_STATE) {
+        if (s->gzhead->hcrc) {
+            if (s->pending + 2 > s->pending_buf_size) {
+                flush_pending(strm);
+                if (s->pending != 0) {
+                    s->last_flush = -1;
+                    return Z_OK;
+                }
+            }
+            put_byte(s, (Byte)(strm->adler & 0xff));
+            put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
+            strm->adler = crc32(0L, Z_NULL, 0);
+        }
+        s->status = BUSY_STATE;
+
+        /* Compression must start with an empty pending buffer */
+        flush_pending(strm);
+        if (s->pending != 0) {
+            s->last_flush = -1;
+            return Z_OK;
+        }
+    }
+#endif
+
+    /* Start a new block or continue the current one.
+     */
+    if (strm->avail_in != 0 || s->lookahead != 0 ||
+        (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
+        block_state bstate;
+
+        bstate = s->level == 0 ? deflate_stored(s, flush) :
+                 s->strategy == Z_HUFFMAN_ONLY ? deflate_huff(s, flush) :
+                 s->strategy == Z_RLE ? deflate_rle(s, flush) :
+                 (*(configuration_table[s->level].func))(s, flush);
+
+        if (bstate == finish_started || bstate == finish_done) {
+            s->status = FINISH_STATE;
+        }
+        if (bstate == need_more || bstate == finish_started) {
+            if (strm->avail_out == 0) {
+                s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
+            }
+            return Z_OK;
+            /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
+             * of deflate should use the same flush parameter to make sure
+             * that the flush is complete. So we don't have to output an
+             * empty block here, this will be done at next call. This also
+             * ensures that for a very small output buffer, we emit at most
+             * one empty block.
+             */
+        }
+        if (bstate == block_done) {
+            if (flush == Z_PARTIAL_FLUSH) {
+                _tr_align(s);
+            } else if (flush != Z_BLOCK) { /* FULL_FLUSH or SYNC_FLUSH */
+                _tr_stored_block(s, (char*)0, 0L, 0);
+                /* For a full flush, this empty block will be recognized
+                 * as a special marker by inflate_sync().
+                 */
+                if (flush == Z_FULL_FLUSH) {
+                    CLEAR_HASH(s);             /* forget history */
+                    if (s->lookahead == 0) {
+                        s->strstart = 0;
+                        s->block_start = 0L;
+                        s->insert = 0;
+                    }
+                }
+            }
+            flush_pending(strm);
+            if (strm->avail_out == 0) {
+              s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
+              return Z_OK;
+            }
+        }
+    }
+
+    if (flush != Z_FINISH) return Z_OK;
+    if (s->wrap <= 0) return Z_STREAM_END;
+
+    /* Write the trailer */
+#ifdef GZIP
+    if (s->wrap == 2) {
+        put_byte(s, (Byte)(strm->adler & 0xff));
+        put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
+        put_byte(s, (Byte)((strm->adler >> 16) & 0xff));
+        put_byte(s, (Byte)((strm->adler >> 24) & 0xff));
+        put_byte(s, (Byte)(strm->total_in & 0xff));
+        put_byte(s, (Byte)((strm->total_in >> 8) & 0xff));
+        put_byte(s, (Byte)((strm->total_in >> 16) & 0xff));
+        put_byte(s, (Byte)((strm->total_in >> 24) & 0xff));
+    }
+    else
+#endif
+    {
+        putShortMSB(s, (uInt)(strm->adler >> 16));
+        putShortMSB(s, (uInt)(strm->adler & 0xffff));
+    }
+    flush_pending(strm);
+    /* If avail_out is zero, the application will call deflate again
+     * to flush the rest.
+     */
+    if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */
+    return s->pending != 0 ? Z_OK : Z_STREAM_END;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateEnd (strm)
+    z_streamp strm;
+{
+    int status;
+
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
+
+    status = strm->state->status;
+
+    /* Deallocate in reverse order of allocations: */
+    TRY_FREE(strm, strm->state->pending_buf);
+    TRY_FREE(strm, strm->state->head);
+    TRY_FREE(strm, strm->state->prev);
+    TRY_FREE(strm, strm->state->window);
+
+    ZFREE(strm, strm->state);
+    strm->state = Z_NULL;
+
+    return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
+}
+
+/* =========================================================================
+ * Copy the source state to the destination state.
+ * To simplify the source, this is not supported for 16-bit MSDOS (which
+ * doesn't have enough memory anyway to duplicate compression states).
+ */
+int ZEXPORT deflateCopy (dest, source)
+    z_streamp dest;
+    z_streamp source;
+{
+#ifdef MAXSEG_64K
+    return Z_STREAM_ERROR;
+#else
+    deflate_state *ds;
+    deflate_state *ss;
+    ushf *overlay;
+
+
+    if (deflateStateCheck(source) || dest == Z_NULL) {
+        return Z_STREAM_ERROR;
+    }
+
+    ss = source->state;
+
+    zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
+
+    ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
+    if (ds == Z_NULL) return Z_MEM_ERROR;
+    dest->state = (struct internal_state FAR *) ds;
+    zmemcpy((voidpf)ds, (voidpf)ss, sizeof(deflate_state));
+    ds->strm = dest;
+
+    ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
+    ds->prev   = (Posf *)  ZALLOC(dest, ds->w_size, sizeof(Pos));
+    ds->head   = (Posf *)  ZALLOC(dest, ds->hash_size, sizeof(Pos));
+    overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
+    ds->pending_buf = (uchf *) overlay;
+
+    if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
+        ds->pending_buf == Z_NULL) {
+        deflateEnd (dest);
+        return Z_MEM_ERROR;
+    }
+    /* following zmemcpy do not work for 16-bit MSDOS */
+    zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
+    zmemcpy((voidpf)ds->prev, (voidpf)ss->prev, ds->w_size * sizeof(Pos));
+    zmemcpy((voidpf)ds->head, (voidpf)ss->head, ds->hash_size * sizeof(Pos));
+    zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
+
+    ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
+    ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
+    ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
+
+    ds->l_desc.dyn_tree = ds->dyn_ltree;
+    ds->d_desc.dyn_tree = ds->dyn_dtree;
+    ds->bl_desc.dyn_tree = ds->bl_tree;
+
+    return Z_OK;
+#endif /* MAXSEG_64K */
+}
+
+/* ===========================================================================
+ * Read a new buffer from the current input stream, update the adler32
+ * and total number of bytes read.  All deflate() input goes through
+ * this function so some applications may wish to modify it to avoid
+ * allocating a large strm->next_in buffer and copying from it.
+ * (See also flush_pending()).
+ */
+local unsigned read_buf(strm, buf, size)
+    z_streamp strm;
+    Bytef *buf;
+    unsigned size;
+{
+    unsigned len = strm->avail_in;
+
+    if (len > size) len = size;
+    if (len == 0) return 0;
+
+    strm->avail_in  -= len;
+
+    zmemcpy(buf, strm->next_in, len);
+    if (strm->state->wrap == 1) {
+        strm->adler = adler32(strm->adler, buf, len);
+    }
+#ifdef GZIP
+    else if (strm->state->wrap == 2) {
+        strm->adler = crc32(strm->adler, buf, len);
+    }
+#endif
+    strm->next_in  += len;
+    strm->total_in += len;
+
+    return len;
+}
+
+/* ===========================================================================
+ * Initialize the "longest match" routines for a new zlib stream
+ */
+local void lm_init (s)
+    deflate_state *s;
+{
+    s->window_size = (ulg)2L*s->w_size;
+
+    CLEAR_HASH(s);
+
+    /* Set the default configuration parameters:
+     */
+    s->max_lazy_match   = configuration_table[s->level].max_lazy;
+    s->good_match       = configuration_table[s->level].good_length;
+    s->nice_match       = configuration_table[s->level].nice_length;
+    s->max_chain_length = configuration_table[s->level].max_chain;
+
+    s->strstart = 0;
+    s->block_start = 0L;
+    s->lookahead = 0;
+    s->insert = 0;
+    s->match_length = s->prev_length = MIN_MATCH-1;
+    s->match_available = 0;
+    s->ins_h = 0;
+#ifndef FASTEST
+#ifdef ASMV
+    match_init(); /* initialize the asm code */
+#endif
+#endif
+}
+
+#ifndef FASTEST
+/* ===========================================================================
+ * Set match_start to the longest match starting at the given string and
+ * return its length. Matches shorter or equal to prev_length are discarded,
+ * in which case the result is equal to prev_length and match_start is
+ * garbage.
+ * IN assertions: cur_match is the head of the hash chain for the current
+ *   string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
+ * OUT assertion: the match length is not greater than s->lookahead.
+ */
+#ifndef ASMV
+/* For 80x86 and 680x0, an optimized version will be provided in match.asm or
+ * match.S. The code will be functionally equivalent.
+ */
+local uInt longest_match(s, cur_match)
+    deflate_state *s;
+    IPos cur_match;                             /* current match */
+{
+    unsigned chain_length = s->max_chain_length;/* max hash chain length */
+    register Bytef *scan = s->window + s->strstart; /* current string */
+    register Bytef *match;                      /* matched string */
+    register int len;                           /* length of current match */
+    int best_len = (int)s->prev_length;         /* best match length so far */
+    int nice_match = s->nice_match;             /* stop if match long enough */
+    IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
+        s->strstart - (IPos)MAX_DIST(s) : NIL;
+    /* Stop when cur_match becomes <= limit. To simplify the code,
+     * we prevent matches with the string of window index 0.
+     */
+    Posf *prev = s->prev;
+    uInt wmask = s->w_mask;
+
+#ifdef UNALIGNED_OK
+    /* Compare two bytes at a time. Note: this is not always beneficial.
+     * Try with and without -DUNALIGNED_OK to check.
+     */
+    register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
+    register ush scan_start = *(ushf*)scan;
+    register ush scan_end   = *(ushf*)(scan+best_len-1);
+#else
+    register Bytef *strend = s->window + s->strstart + MAX_MATCH;
+    register Byte scan_end1  = scan[best_len-1];
+    register Byte scan_end   = scan[best_len];
+#endif
+
+    /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
+     * It is easy to get rid of this optimization if necessary.
+     */
+    Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
+
+    /* Do not waste too much time if we already have a good match: */
+    if (s->prev_length >= s->good_match) {
+        chain_length >>= 2;
+    }
+    /* Do not look for matches beyond the end of the input. This is necessary
+     * to make deflate deterministic.
+     */
+    if ((uInt)nice_match > s->lookahead) nice_match = (int)s->lookahead;
+
+    Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
+
+    do {
+        Assert(cur_match < s->strstart, "no future");
+        match = s->window + cur_match;
+
+        /* Skip to next match if the match length cannot increase
+         * or if the match length is less than 2.  Note that the checks below
+         * for insufficient lookahead only occur occasionally for performance
+         * reasons.  Therefore uninitialized memory will be accessed, and
+         * conditional jumps will be made that depend on those values.
+         * However the length of the match is limited to the lookahead, so
+         * the output of deflate is not affected by the uninitialized values.
+         */
+#if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
+        /* This code assumes sizeof(unsigned short) == 2. Do not use
+         * UNALIGNED_OK if your compiler uses a different size.
+         */
+        if (*(ushf*)(match+best_len-1) != scan_end ||
+            *(ushf*)match != scan_start) continue;
+
+        /* It is not necessary to compare scan[2] and match[2] since they are
+         * always equal when the other bytes match, given that the hash keys
+         * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
+         * strstart+3, +5, ... up to strstart+257. We check for insufficient
+         * lookahead only every 4th comparison; the 128th check will be made
+         * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
+         * necessary to put more guard bytes at the end of the window, or
+         * to check more often for insufficient lookahead.
+         */
+        Assert(scan[2] == match[2], "scan[2]?");
+        scan++, match++;
+        do {
+        } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
+                 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
+                 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
+                 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
+                 scan < strend);
+        /* The funny "do {}" generates better code on most compilers */
+
+        /* Here, scan <= window+strstart+257 */
+        Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
+        if (*scan == *match) scan++;
+
+        len = (MAX_MATCH - 1) - (int)(strend-scan);
+        scan = strend - (MAX_MATCH-1);
+
+#else /* UNALIGNED_OK */
+
+        if (match[best_len]   != scan_end  ||
+            match[best_len-1] != scan_end1 ||
+            *match            != *scan     ||
+            *++match          != scan[1])      continue;
+
+        /* The check at best_len-1 can be removed because it will be made
+         * again later. (This heuristic is not always a win.)
+         * It is not necessary to compare scan[2] and match[2] since they
+         * are always equal when the other bytes match, given that
+         * the hash keys are equal and that HASH_BITS >= 8.
+         */
+        scan += 2, match++;
+        Assert(*scan == *match, "match[2]?");
+
+        /* We check for insufficient lookahead only every 8th comparison;
+         * the 256th check will be made at strstart+258.
+         */
+        do {
+        } while (*++scan == *++match && *++scan == *++match &&
+                 *++scan == *++match && *++scan == *++match &&
+                 *++scan == *++match && *++scan == *++match &&
+                 *++scan == *++match && *++scan == *++match &&
+                 scan < strend);
+
+        Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
+
+        len = MAX_MATCH - (int)(strend - scan);
+        scan = strend - MAX_MATCH;
+
+#endif /* UNALIGNED_OK */
+
+        if (len > best_len) {
+            s->match_start = cur_match;
+            best_len = len;
+            if (len >= nice_match) break;
+#ifdef UNALIGNED_OK
+            scan_end = *(ushf*)(scan+best_len-1);
+#else
+            scan_end1  = scan[best_len-1];
+            scan_end   = scan[best_len];
+#endif
+        }
+    } while ((cur_match = prev[cur_match & wmask]) > limit
+             && --chain_length != 0);
+
+    if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
+    return s->lookahead;
+}
+#endif /* ASMV */
+
+#else /* FASTEST */
+
+/* ---------------------------------------------------------------------------
+ * Optimized version for FASTEST only
+ */
+local uInt longest_match(s, cur_match)
+    deflate_state *s;
+    IPos cur_match;                             /* current match */
+{
+    register Bytef *scan = s->window + s->strstart; /* current string */
+    register Bytef *match;                       /* matched string */
+    register int len;                           /* length of current match */
+    register Bytef *strend = s->window + s->strstart + MAX_MATCH;
+
+    /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
+     * It is easy to get rid of this optimization if necessary.
+     */
+    Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
+
+    Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
+
+    Assert(cur_match < s->strstart, "no future");
+
+    match = s->window + cur_match;
+
+    /* Return failure if the match length is less than 2:
+     */
+    if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1;
+
+    /* The check at best_len-1 can be removed because it will be made
+     * again later. (This heuristic is not always a win.)
+     * It is not necessary to compare scan[2] and match[2] since they
+     * are always equal when the other bytes match, given that
+     * the hash keys are equal and that HASH_BITS >= 8.
+     */
+    scan += 2, match += 2;
+    Assert(*scan == *match, "match[2]?");
+
+    /* We check for insufficient lookahead only every 8th comparison;
+     * the 256th check will be made at strstart+258.
+     */
+    do {
+    } while (*++scan == *++match && *++scan == *++match &&
+             *++scan == *++match && *++scan == *++match &&
+             *++scan == *++match && *++scan == *++match &&
+             *++scan == *++match && *++scan == *++match &&
+             scan < strend);
+
+    Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
+
+    len = MAX_MATCH - (int)(strend - scan);
+
+    if (len < MIN_MATCH) return MIN_MATCH - 1;
+
+    s->match_start = cur_match;
+    return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead;
+}
+
+#endif /* FASTEST */
+
+#ifdef ZLIB_DEBUG
+
+#define EQUAL 0
+/* result of memcmp for equal strings */
+
+/* ===========================================================================
+ * Check that the match at match_start is indeed a match.
+ */
+local void check_match(s, start, match, length)
+    deflate_state *s;
+    IPos start, match;
+    int length;
+{
+    /* check that the match is indeed a match */
+    if (zmemcmp(s->window + match,
+                s->window + start, length) != EQUAL) {
+        fprintf(stderr, " start %u, match %u, length %d\n",
+                start, match, length);
+        do {
+            fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
+        } while (--length != 0);
+        z_error("invalid match");
+    }
+    if (z_verbose > 1) {
+        fprintf(stderr,"\\[%d,%d]", start-match, length);
+        do { putc(s->window[start++], stderr); } while (--length != 0);
+    }
+}
+#else
+#  define check_match(s, start, match, length)
+#endif /* ZLIB_DEBUG */
+
+/* ===========================================================================
+ * Fill the window when the lookahead becomes insufficient.
+ * Updates strstart and lookahead.
+ *
+ * IN assertion: lookahead < MIN_LOOKAHEAD
+ * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
+ *    At least one byte has been read, or avail_in == 0; reads are
+ *    performed for at least two bytes (required for the zip translate_eol
+ *    option -- not supported here).
+ */
+local void fill_window(s)
+    deflate_state *s;
+{
+    unsigned n;
+    unsigned more;    /* Amount of free space at the end of the window. */
+    uInt wsize = s->w_size;
+
+    Assert(s->lookahead < MIN_LOOKAHEAD, "already enough lookahead");
+
+    do {
+        more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
+
+        /* Deal with !@#$% 64K limit: */
+        if (sizeof(int) <= 2) {
+            if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
+                more = wsize;
+
+            } else if (more == (unsigned)(-1)) {
+                /* Very unlikely, but possible on 16 bit machine if
+                 * strstart == 0 && lookahead == 1 (input done a byte at time)
+                 */
+                more--;
+            }
+        }
+
+        /* If the window is almost full and there is insufficient lookahead,
+         * move the upper half to the lower one to make room in the upper half.
+         */
+        if (s->strstart >= wsize+MAX_DIST(s)) {
+
+            zmemcpy(s->window, s->window+wsize, (unsigned)wsize - more);
+            s->match_start -= wsize;
+            s->strstart    -= wsize; /* we now have strstart >= MAX_DIST */
+            s->block_start -= (long) wsize;
+            slide_hash(s);
+            more += wsize;
+        }
+        if (s->strm->avail_in == 0) break;
+
+        /* If there was no sliding:
+         *    strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
+         *    more == window_size - lookahead - strstart
+         * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
+         * => more >= window_size - 2*WSIZE + 2
+         * In the BIG_MEM or MMAP case (not yet supported),
+         *   window_size == input_size + MIN_LOOKAHEAD  &&
+         *   strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
+         * Otherwise, window_size == 2*WSIZE so more >= 2.
+         * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
+         */
+        Assert(more >= 2, "more < 2");
+
+        n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
+        s->lookahead += n;
+
+        /* Initialize the hash value now that we have some input: */
+        if (s->lookahead + s->insert >= MIN_MATCH) {
+            uInt str = s->strstart - s->insert;
+            s->ins_h = s->window[str];
+            UPDATE_HASH(s, s->ins_h, s->window[str + 1]);
+#if MIN_MATCH != 3
+            Call UPDATE_HASH() MIN_MATCH-3 more times
+#endif
+            while (s->insert) {
+                UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]);
+#ifndef FASTEST
+                s->prev[str & s->w_mask] = s->head[s->ins_h];
+#endif
+                s->head[s->ins_h] = (Pos)str;
+                str++;
+                s->insert--;
+                if (s->lookahead + s->insert < MIN_MATCH)
+                    break;
+            }
+        }
+        /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
+         * but this is not important since only literal bytes will be emitted.
+         */
+
+    } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
+
+    /* If the WIN_INIT bytes after the end of the current data have never been
+     * written, then zero those bytes in order to avoid memory check reports of
+     * the use of uninitialized (or uninitialised as Julian writes) bytes by
+     * the longest match routines.  Update the high water mark for the next
+     * time through here.  WIN_INIT is set to MAX_MATCH since the longest match
+     * routines allow scanning to strstart + MAX_MATCH, ignoring lookahead.
+     */
+    if (s->high_water < s->window_size) {
+        ulg curr = s->strstart + (ulg)(s->lookahead);
+        ulg init;
+
+        if (s->high_water < curr) {
+            /* Previous high water mark below current data -- zero WIN_INIT
+             * bytes or up to end of window, whichever is less.
+             */
+            init = s->window_size - curr;
+            if (init > WIN_INIT)
+                init = WIN_INIT;
+            zmemzero(s->window + curr, (unsigned)init);
+            s->high_water = curr + init;
+        }
+        else if (s->high_water < (ulg)curr + WIN_INIT) {
+            /* High water mark at or above current data, but below current data
+             * plus WIN_INIT -- zero out to current data plus WIN_INIT, or up
+             * to end of window, whichever is less.
+             */
+            init = (ulg)curr + WIN_INIT - s->high_water;
+            if (init > s->window_size - s->high_water)
+                init = s->window_size - s->high_water;
+            zmemzero(s->window + s->high_water, (unsigned)init);
+            s->high_water += init;
+        }
+    }
+
+    Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD,
+           "not enough room for search");
+}
+
+/* ===========================================================================
+ * Flush the current block, with given end-of-file flag.
+ * IN assertion: strstart is set to the end of the current match.
+ */
+#define FLUSH_BLOCK_ONLY(s, last) { \
+   _tr_flush_block(s, (s->block_start >= 0L ? \
+                   (charf *)&s->window[(unsigned)s->block_start] : \
+                   (charf *)Z_NULL), \
+                (ulg)((long)s->strstart - s->block_start), \
+                (last)); \
+   s->block_start = s->strstart; \
+   flush_pending(s->strm); \
+   Tracev((stderr,"[FLUSH]")); \
+}
+
+/* Same but force premature exit if necessary. */
+#define FLUSH_BLOCK(s, last) { \
+   FLUSH_BLOCK_ONLY(s, last); \
+   if (s->strm->avail_out == 0) return (last) ? finish_started : need_more; \
+}
+
+/* Maximum stored block length in deflate format (not including header). */
+#define MAX_STORED 65535
+
+/* Minimum of a and b. */
+#define MIN(a, b) ((a) > (b) ? (b) : (a))
+
+/* ===========================================================================
+ * Copy without compression as much as possible from the input stream, return
+ * the current block state.
+ *
+ * In case deflateParams() is used to later switch to a non-zero compression
+ * level, s->matches (otherwise unused when storing) keeps track of the number
+ * of hash table slides to perform. If s->matches is 1, then one hash table
+ * slide will be done when switching. If s->matches is 2, the maximum value
+ * allowed here, then the hash table will be cleared, since two or more slides
+ * is the same as a clear.
+ *
+ * deflate_stored() is written to minimize the number of times an input byte is
+ * copied. It is most efficient with large input and output buffers, which
+ * maximizes the opportunites to have a single copy from next_in to next_out.
+ */
+local block_state deflate_stored(s, flush)
+    deflate_state *s;
+    int flush;
+{
+    /* Smallest worthy block size when not flushing or finishing. By default
+     * this is 32K. This can be as small as 507 bytes for memLevel == 1. For
+     * large input and output buffers, the stored block size will be larger.
+     */
+    unsigned min_block = MIN(s->pending_buf_size - 5, s->w_size);
+
+    /* Copy as many min_block or larger stored blocks directly to next_out as
+     * possible. If flushing, copy the remaining available input to next_out as
+     * stored blocks, if there is enough space.
+     */
+    unsigned len, left, have, last = 0;
+    unsigned used = s->strm->avail_in;
+    do {
+        /* Set len to the maximum size block that we can copy directly with the
+         * available input data and output space. Set left to how much of that
+         * would be copied from what's left in the window.
+         */
+        len = MAX_STORED;       /* maximum deflate stored block length */
+        have = (s->bi_valid + 42) >> 3;         /* number of header bytes */
+        if (s->strm->avail_out < have)          /* need room for header */
+            break;
+            /* maximum stored block length that will fit in avail_out: */
+        have = s->strm->avail_out - have;
+        left = s->strstart - s->block_start;    /* bytes left in window */
+        if (len > (ulg)left + s->strm->avail_in)
+            len = left + s->strm->avail_in;     /* limit len to the input */
+        if (len > have)
+            len = have;                         /* limit len to the output */
+
+        /* If the stored block would be less than min_block in length, or if
+         * unable to copy all of the available input when flushing, then try
+         * copying to the window and the pending buffer instead. Also don't
+         * write an empty block when flushing -- deflate() does that.
+         */
+        if (len < min_block && ((len == 0 && flush != Z_FINISH) ||
+                                flush == Z_NO_FLUSH ||
+                                len != left + s->strm->avail_in))
+            break;
+
+        /* Make a dummy stored block in pending to get the header bytes,
+         * including any pending bits. This also updates the debugging counts.
+         */
+        last = flush == Z_FINISH && len == left + s->strm->avail_in ? 1 : 0;
+        _tr_stored_block(s, (char *)0, 0L, last);
+
+        /* Replace the lengths in the dummy stored block with len. */
+        s->pending_buf[s->pending - 4] = len;
+        s->pending_buf[s->pending - 3] = len >> 8;
+        s->pending_buf[s->pending - 2] = ~len;
+        s->pending_buf[s->pending - 1] = ~len >> 8;
+
+        /* Write the stored block header bytes. */
+        flush_pending(s->strm);
+
+#ifdef ZLIB_DEBUG
+        /* Update debugging counts for the data about to be copied. */
+        s->compressed_len += len << 3;
+        s->bits_sent += len << 3;
+#endif
+
+        /* Copy uncompressed bytes from the window to next_out. */
+        if (left) {
+            if (left > len)
+                left = len;
+            zmemcpy(s->strm->next_out, s->window + s->block_start, left);
+            s->strm->next_out += left;
+            s->strm->avail_out -= left;
+            s->strm->total_out += left;
+            s->block_start += left;
+            len -= left;
+        }
+
+        /* Copy uncompressed bytes directly from next_in to next_out, updating
+         * the check value.
+         */
+        if (len) {
+            read_buf(s->strm, s->strm->next_out, len);
+            s->strm->next_out += len;
+            s->strm->avail_out -= len;
+            s->strm->total_out += len;
+        }
+    } while (last == 0);
+
+    /* Update the sliding window with the last s->w_size bytes of the copied
+     * data, or append all of the copied data to the existing window if less
+     * than s->w_size bytes were copied. Also update the number of bytes to
+     * insert in the hash tables, in the event that deflateParams() switches to
+     * a non-zero compression level.
+     */
+    used -= s->strm->avail_in;      /* number of input bytes directly copied */
+    if (used) {
+        /* If any input was used, then no unused input remains in the window,
+         * therefore s->block_start == s->strstart.
+         */
+        if (used >= s->w_size) {    /* supplant the previous history */
+            s->matches = 2;         /* clear hash */
+            zmemcpy(s->window, s->strm->next_in - s->w_size, s->w_size);
+            s->strstart = s->w_size;
+        }
+        else {
+            if (s->window_size - s->strstart <= used) {
+                /* Slide the window down. */
+                s->strstart -= s->w_size;
+                zmemcpy(s->window, s->window + s->w_size, s->strstart);
+                if (s->matches < 2)
+                    s->matches++;   /* add a pending slide_hash() */
+            }
+            zmemcpy(s->window + s->strstart, s->strm->next_in - used, used);
+            s->strstart += used;
+        }
+        s->block_start = s->strstart;
+        s->insert += MIN(used, s->w_size - s->insert);
+    }
+    if (s->high_water < s->strstart)
+        s->high_water = s->strstart;
+
+    /* If the last block was written to next_out, then done. */
+    if (last)
+        return finish_done;
+
+    /* If flushing and all input has been consumed, then done. */
+    if (flush != Z_NO_FLUSH && flush != Z_FINISH &&
+        s->strm->avail_in == 0 && (long)s->strstart == s->block_start)
+        return block_done;
+
+    /* Fill the window with any remaining input. */
+    have = s->window_size - s->strstart - 1;
+    if (s->strm->avail_in > have && s->block_start >= (long)s->w_size) {
+        /* Slide the window down. */
+        s->block_start -= s->w_size;
+        s->strstart -= s->w_size;
+        zmemcpy(s->window, s->window + s->w_size, s->strstart);
+        if (s->matches < 2)
+            s->matches++;           /* add a pending slide_hash() */
+        have += s->w_size;          /* more space now */
+    }
+    if (have > s->strm->avail_in)
+        have = s->strm->avail_in;
+    if (have) {
+        read_buf(s->strm, s->window + s->strstart, have);
+        s->strstart += have;
+    }
+    if (s->high_water < s->strstart)
+        s->high_water = s->strstart;
+
+    /* There was not enough avail_out to write a complete worthy or flushed
+     * stored block to next_out. Write a stored block to pending instead, if we
+     * have enough input for a worthy block, or if flushing and there is enough
+     * room for the remaining input as a stored block in the pending buffer.
+     */
+    have = (s->bi_valid + 42) >> 3;         /* number of header bytes */
+        /* maximum stored block length that will fit in pending: */
+    have = MIN(s->pending_buf_size - have, MAX_STORED);
+    min_block = MIN(have, s->w_size);
+    left = s->strstart - s->block_start;
+    if (left >= min_block ||
+        ((left || flush == Z_FINISH) && flush != Z_NO_FLUSH &&
+         s->strm->avail_in == 0 && left <= have)) {
+        len = MIN(left, have);
+        last = flush == Z_FINISH && s->strm->avail_in == 0 &&
+               len == left ? 1 : 0;
+        _tr_stored_block(s, (charf *)s->window + s->block_start, len, last);
+        s->block_start += len;
+        flush_pending(s->strm);
+    }
+
+    /* We've done all we can with the available input and output. */
+    return last ? finish_started : need_more;
+}
+
+/* ===========================================================================
+ * Compress as much as possible from the input stream, return the current
+ * block state.
+ * This function does not perform lazy evaluation of matches and inserts
+ * new strings in the dictionary only for unmatched strings or for short
+ * matches. It is used only for the fast compression options.
+ */
+local block_state deflate_fast(s, flush)
+    deflate_state *s;
+    int flush;
+{
+    IPos hash_head;       /* head of the hash chain */
+    int bflush;           /* set if current block must be flushed */
+
+    for (;;) {
+        /* Make sure that we always have enough lookahead, except
+         * at the end of the input file. We need MAX_MATCH bytes
+         * for the next match, plus MIN_MATCH bytes to insert the
+         * string following the next match.
+         */
+        if (s->lookahead < MIN_LOOKAHEAD) {
+            fill_window(s);
+            if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
+                return need_more;
+            }
+            if (s->lookahead == 0) break; /* flush the current block */
+        }
+
+        /* Insert the string window[strstart .. strstart+2] in the
+         * dictionary, and set hash_head to the head of the hash chain:
+         */
+        hash_head = NIL;
+        if (s->lookahead >= MIN_MATCH) {
+            INSERT_STRING(s, s->strstart, hash_head);
+        }
+
+        /* Find the longest match, discarding those <= prev_length.
+         * At this point we have always match_length < MIN_MATCH
+         */
+        if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
+            /* To simplify the code, we prevent matches with the string
+             * of window index 0 (in particular we have to avoid a match
+             * of the string with itself at the start of the input file).
+             */
+            s->match_length = longest_match (s, hash_head);
+            /* longest_match() sets match_start */
+        }
+        if (s->match_length >= MIN_MATCH) {
+            check_match(s, s->strstart, s->match_start, s->match_length);
+
+            _tr_tally_dist(s, s->strstart - s->match_start,
+                           s->match_length - MIN_MATCH, bflush);
+
+            s->lookahead -= s->match_length;
+
+            /* Insert new strings in the hash table only if the match length
+             * is not too large. This saves time but degrades compression.
+             */
+#ifndef FASTEST
+            if (s->match_length <= s->max_insert_length &&
+                s->lookahead >= MIN_MATCH) {
+                s->match_length--; /* string at strstart already in table */
+                do {
+                    s->strstart++;
+                    INSERT_STRING(s, s->strstart, hash_head);
+                    /* strstart never exceeds WSIZE-MAX_MATCH, so there are
+                     * always MIN_MATCH bytes ahead.
+                     */
+                } while (--s->match_length != 0);
+                s->strstart++;
+            } else
+#endif
+            {
+                s->strstart += s->match_length;
+                s->match_length = 0;
+                s->ins_h = s->window[s->strstart];
+                UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
+#if MIN_MATCH != 3
+                Call UPDATE_HASH() MIN_MATCH-3 more times
+#endif
+                /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
+                 * matter since it will be recomputed at next deflate call.
+                 */
+            }
+        } else {
+            /* No match, output a literal byte */
+            Tracevv((stderr,"%c", s->window[s->strstart]));
+            _tr_tally_lit (s, s->window[s->strstart], bflush);
+            s->lookahead--;
+            s->strstart++;
+        }
+        if (bflush) FLUSH_BLOCK(s, 0);
+    }
+    s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1;
+    if (flush == Z_FINISH) {
+        FLUSH_BLOCK(s, 1);
+        return finish_done;
+    }
+    if (s->last_lit)
+        FLUSH_BLOCK(s, 0);
+    return block_done;
+}
+
+#ifndef FASTEST
+/* ===========================================================================
+ * Same as above, but achieves better compression. We use a lazy
+ * evaluation for matches: a match is finally adopted only if there is
+ * no better match at the next window position.
+ */
+local block_state deflate_slow(s, flush)
+    deflate_state *s;
+    int flush;
+{
+    IPos hash_head;          /* head of hash chain */
+    int bflush;              /* set if current block must be flushed */
+
+    /* Process the input block. */
+    for (;;) {
+        /* Make sure that we always have enough lookahead, except
+         * at the end of the input file. We need MAX_MATCH bytes
+         * for the next match, plus MIN_MATCH bytes to insert the
+         * string following the next match.
+         */
+        if (s->lookahead < MIN_LOOKAHEAD) {
+            fill_window(s);
+            if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
+                return need_more;
+            }
+            if (s->lookahead == 0) break; /* flush the current block */
+        }
+
+        /* Insert the string window[strstart .. strstart+2] in the
+         * dictionary, and set hash_head to the head of the hash chain:
+         */
+        hash_head = NIL;
+        if (s->lookahead >= MIN_MATCH) {
+            INSERT_STRING(s, s->strstart, hash_head);
+        }
+
+        /* Find the longest match, discarding those <= prev_length.
+         */
+        s->prev_length = s->match_length, s->prev_match = s->match_start;
+        s->match_length = MIN_MATCH-1;
+
+        if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
+            s->strstart - hash_head <= MAX_DIST(s)) {
+            /* To simplify the code, we prevent matches with the string
+             * of window index 0 (in particular we have to avoid a match
+             * of the string with itself at the start of the input file).
+             */
+            s->match_length = longest_match (s, hash_head);
+            /* longest_match() sets match_start */
+
+            if (s->match_length <= 5 && (s->strategy == Z_FILTERED
+#if TOO_FAR <= 32767
+                || (s->match_length == MIN_MATCH &&
+                    s->strstart - s->match_start > TOO_FAR)
+#endif
+                )) {
+
+                /* If prev_match is also MIN_MATCH, match_start is garbage
+                 * but we will ignore the current match anyway.
+                 */
+                s->match_length = MIN_MATCH-1;
+            }
+        }
+        /* If there was a match at the previous step and the current
+         * match is not better, output the previous match:
+         */
+        if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
+            uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
+            /* Do not insert strings in hash table beyond this. */
+
+            check_match(s, s->strstart-1, s->prev_match, s->prev_length);
+
+            _tr_tally_dist(s, s->strstart -1 - s->prev_match,
+                           s->prev_length - MIN_MATCH, bflush);
+
+            /* Insert in hash table all strings up to the end of the match.
+             * strstart-1 and strstart are already inserted. If there is not
+             * enough lookahead, the last two strings are not inserted in
+             * the hash table.
+             */
+            s->lookahead -= s->prev_length-1;
+            s->prev_length -= 2;
+            do {
+                if (++s->strstart <= max_insert) {
+                    INSERT_STRING(s, s->strstart, hash_head);
+                }
+            } while (--s->prev_length != 0);
+            s->match_available = 0;
+            s->match_length = MIN_MATCH-1;
+            s->strstart++;
+
+            if (bflush) FLUSH_BLOCK(s, 0);
+
+        } else if (s->match_available) {
+            /* If there was no match at the previous position, output a
+             * single literal. If there was a match but the current match
+             * is longer, truncate the previous match to a single literal.
+             */
+            Tracevv((stderr,"%c", s->window[s->strstart-1]));
+            _tr_tally_lit(s, s->window[s->strstart-1], bflush);
+            if (bflush) {
+                FLUSH_BLOCK_ONLY(s, 0);
+            }
+            s->strstart++;
+            s->lookahead--;
+            if (s->strm->avail_out == 0) return need_more;
+        } else {
+            /* There is no previous match to compare with, wait for
+             * the next step to decide.
+             */
+            s->match_available = 1;
+            s->strstart++;
+            s->lookahead--;
+        }
+    }
+    Assert (flush != Z_NO_FLUSH, "no flush?");
+    if (s->match_available) {
+        Tracevv((stderr,"%c", s->window[s->strstart-1]));
+        _tr_tally_lit(s, s->window[s->strstart-1], bflush);
+        s->match_available = 0;
+    }
+    s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1;
+    if (flush == Z_FINISH) {
+        FLUSH_BLOCK(s, 1);
+        return finish_done;
+    }
+    if (s->last_lit)
+        FLUSH_BLOCK(s, 0);
+    return block_done;
+}
+#endif /* FASTEST */
+
+/* ===========================================================================
+ * For Z_RLE, simply look for runs of bytes, generate matches only of distance
+ * one.  Do not maintain a hash table.  (It will be regenerated if this run of
+ * deflate switches away from Z_RLE.)
+ */
+local block_state deflate_rle(s, flush)
+    deflate_state *s;
+    int flush;
+{
+    int bflush;             /* set if current block must be flushed */
+    uInt prev;              /* byte at distance one to match */
+    Bytef *scan, *strend;   /* scan goes up to strend for length of run */
+
+    for (;;) {
+        /* Make sure that we always have enough lookahead, except
+         * at the end of the input file. We need MAX_MATCH bytes
+         * for the longest run, plus one for the unrolled loop.
+         */
+        if (s->lookahead <= MAX_MATCH) {
+            fill_window(s);
+            if (s->lookahead <= MAX_MATCH && flush == Z_NO_FLUSH) {
+                return need_more;
+            }
+            if (s->lookahead == 0) break; /* flush the current block */
+        }
+
+        /* See how many times the previous byte repeats */
+        s->match_length = 0;
+        if (s->lookahead >= MIN_MATCH && s->strstart > 0) {
+            scan = s->window + s->strstart - 1;
+            prev = *scan;
+            if (prev == *++scan && prev == *++scan && prev == *++scan) {
+                strend = s->window + s->strstart + MAX_MATCH;
+                do {
+                } while (prev == *++scan && prev == *++scan &&
+                         prev == *++scan && prev == *++scan &&
+                         prev == *++scan && prev == *++scan &&
+                         prev == *++scan && prev == *++scan &&
+                         scan < strend);
+                s->match_length = MAX_MATCH - (uInt)(strend - scan);
+                if (s->match_length > s->lookahead)
+                    s->match_length = s->lookahead;
+            }
+            Assert(scan <= s->window+(uInt)(s->window_size-1), "wild scan");
+        }
+
+        /* Emit match if have run of MIN_MATCH or longer, else emit literal */
+        if (s->match_length >= MIN_MATCH) {
+            check_match(s, s->strstart, s->strstart - 1, s->match_length);
+
+            _tr_tally_dist(s, 1, s->match_length - MIN_MATCH, bflush);
+
+            s->lookahead -= s->match_length;
+            s->strstart += s->match_length;
+            s->match_length = 0;
+        } else {
+            /* No match, output a literal byte */
+            Tracevv((stderr,"%c", s->window[s->strstart]));
+            _tr_tally_lit (s, s->window[s->strstart], bflush);
+            s->lookahead--;
+            s->strstart++;
+        }
+        if (bflush) FLUSH_BLOCK(s, 0);
+    }
+    s->insert = 0;
+    if (flush == Z_FINISH) {
+        FLUSH_BLOCK(s, 1);
+        return finish_done;
+    }
+    if (s->last_lit)
+        FLUSH_BLOCK(s, 0);
+    return block_done;
+}
+
+/* ===========================================================================
+ * For Z_HUFFMAN_ONLY, do not look for matches.  Do not maintain a hash table.
+ * (It will be regenerated if this run of deflate switches away from Huffman.)
+ */
+local block_state deflate_huff(s, flush)
+    deflate_state *s;
+    int flush;
+{
+    int bflush;             /* set if current block must be flushed */
+
+    for (;;) {
+        /* Make sure that we have a literal to write. */
+        if (s->lookahead == 0) {
+            fill_window(s);
+            if (s->lookahead == 0) {
+                if (flush == Z_NO_FLUSH)
+                    return need_more;
+                break;      /* flush the current block */
+            }
+        }
+
+        /* Output a literal byte */
+        s->match_length = 0;
+        Tracevv((stderr,"%c", s->window[s->strstart]));
+        _tr_tally_lit (s, s->window[s->strstart], bflush);
+        s->lookahead--;
+        s->strstart++;
+        if (bflush) FLUSH_BLOCK(s, 0);
+    }
+    s->insert = 0;
+    if (flush == Z_FINISH) {
+        FLUSH_BLOCK(s, 1);
+        return finish_done;
+    }
+    if (s->last_lit)
+        FLUSH_BLOCK(s, 0);
+    return block_done;
+}

vendor/libgit2-sys/libgit2/deps/zlib/deflate.h

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/deflate.h b/vendor/libgit2-sys/libgit2/deps/zlib/deflate.h
new file mode 100644
index 0000000..23ecdd3
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/deflate.h
@@ -0,0 +1,349 @@
+/* deflate.h -- internal compression state
+ * Copyright (C) 1995-2016 Jean-loup Gailly
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* @(#) $Id$ */
+
+#ifndef DEFLATE_H
+#define DEFLATE_H
+
+#include "zutil.h"
+
+/* define NO_GZIP when compiling if you want to disable gzip header and
+   trailer creation by deflate().  NO_GZIP would be used to avoid linking in
+   the crc code when it is not needed.  For shared libraries, gzip encoding
+   should be left enabled. */
+#ifndef NO_GZIP
+#  define GZIP
+#endif
+
+/* ===========================================================================
+ * Internal compression state.
+ */
+
+#define LENGTH_CODES 29
+/* number of length codes, not counting the special END_BLOCK code */
+
+#define LITERALS  256
+/* number of literal bytes 0..255 */
+
+#define L_CODES (LITERALS+1+LENGTH_CODES)
+/* number of Literal or Length codes, including the END_BLOCK code */
+
+#define D_CODES   30
+/* number of distance codes */
+
+#define BL_CODES  19
+/* number of codes used to transfer the bit lengths */
+
+#define HEAP_SIZE (2*L_CODES+1)
+/* maximum heap size */
+
+#define MAX_BITS 15
+/* All codes must not exceed MAX_BITS bits */
+
+#define Buf_size 16
+/* size of bit buffer in bi_buf */
+
+#define INIT_STATE    42    /* zlib header -> BUSY_STATE */
+#ifdef GZIP
+#  define GZIP_STATE  57    /* gzip header -> BUSY_STATE | EXTRA_STATE */
+#endif
+#define EXTRA_STATE   69    /* gzip extra block -> NAME_STATE */
+#define NAME_STATE    73    /* gzip file name -> COMMENT_STATE */
+#define COMMENT_STATE 91    /* gzip comment -> HCRC_STATE */
+#define HCRC_STATE   103    /* gzip header CRC -> BUSY_STATE */
+#define BUSY_STATE   113    /* deflate -> FINISH_STATE */
+#define FINISH_STATE 666    /* stream complete */
+/* Stream status */
+
+
+/* Data structure describing a single value and its code string. */
+typedef struct ct_data_s {
+    union {
+        ush  freq;       /* frequency count */
+        ush  code;       /* bit string */
+    } fc;
+    union {
+        ush  dad;        /* father node in Huffman tree */
+        ush  len;        /* length of bit string */
+    } dl;
+} FAR ct_data;
+
+#define Freq fc.freq
+#define Code fc.code
+#define Dad  dl.dad
+#define Len  dl.len
+
+typedef struct static_tree_desc_s  static_tree_desc;
+
+typedef struct tree_desc_s {
+    ct_data *dyn_tree;           /* the dynamic tree */
+    int     max_code;            /* largest code with non zero frequency */
+    const static_tree_desc *stat_desc;  /* the corresponding static tree */
+} FAR tree_desc;
+
+typedef ush Pos;
+typedef Pos FAR Posf;
+typedef unsigned IPos;
+
+/* A Pos is an index in the character window. We use short instead of int to
+ * save space in the various tables. IPos is used only for parameter passing.
+ */
+
+typedef struct internal_state {
+    z_streamp strm;      /* pointer back to this zlib stream */
+    int   status;        /* as the name implies */
+    Bytef *pending_buf;  /* output still pending */
+    ulg   pending_buf_size; /* size of pending_buf */
+    Bytef *pending_out;  /* next pending byte to output to the stream */
+    ulg   pending;       /* nb of bytes in the pending buffer */
+    int   wrap;          /* bit 0 true for zlib, bit 1 true for gzip */
+    gz_headerp  gzhead;  /* gzip header information to write */
+    ulg   gzindex;       /* where in extra, name, or comment */
+    Byte  method;        /* can only be DEFLATED */
+    int   last_flush;    /* value of flush param for previous deflate call */
+
+                /* used by deflate.c: */
+
+    uInt  w_size;        /* LZ77 window size (32K by default) */
+    uInt  w_bits;        /* log2(w_size)  (8..16) */
+    uInt  w_mask;        /* w_size - 1 */
+
+    Bytef *window;
+    /* Sliding window. Input bytes are read into the second half of the window,
+     * and move to the first half later to keep a dictionary of at least wSize
+     * bytes. With this organization, matches are limited to a distance of
+     * wSize-MAX_MATCH bytes, but this ensures that IO is always
+     * performed with a length multiple of the block size. Also, it limits
+     * the window size to 64K, which is quite useful on MSDOS.
+     * To do: use the user input buffer as sliding window.
+     */
+
+    ulg window_size;
+    /* Actual size of window: 2*wSize, except when the user input buffer
+     * is directly used as sliding window.
+     */
+
+    Posf *prev;
+    /* Link to older string with same hash index. To limit the size of this
+     * array to 64K, this link is maintained only for the last 32K strings.
+     * An index in this array is thus a window index modulo 32K.
+     */
+
+    Posf *head; /* Heads of the hash chains or NIL. */
+
+    uInt  ins_h;          /* hash index of string to be inserted */
+    uInt  hash_size;      /* number of elements in hash table */
+    uInt  hash_bits;      /* log2(hash_size) */
+    uInt  hash_mask;      /* hash_size-1 */
+
+    uInt  hash_shift;
+    /* Number of bits by which ins_h must be shifted at each input
+     * step. It must be such that after MIN_MATCH steps, the oldest
+     * byte no longer takes part in the hash key, that is:
+     *   hash_shift * MIN_MATCH >= hash_bits
+     */
+
+    long block_start;
+    /* Window position at the beginning of the current output block. Gets
+     * negative when the window is moved backwards.
+     */
+
+    uInt match_length;           /* length of best match */
+    IPos prev_match;             /* previous match */
+    int match_available;         /* set if previous match exists */
+    uInt strstart;               /* start of string to insert */
+    uInt match_start;            /* start of matching string */
+    uInt lookahead;              /* number of valid bytes ahead in window */
+
+    uInt prev_length;
+    /* Length of the best match at previous step. Matches not greater than this
+     * are discarded. This is used in the lazy match evaluation.
+     */
+
+    uInt max_chain_length;
+    /* To speed up deflation, hash chains are never searched beyond this
+     * length.  A higher limit improves compression ratio but degrades the
+     * speed.
+     */
+
+    uInt max_lazy_match;
+    /* Attempt to find a better match only when the current match is strictly
+     * smaller than this value. This mechanism is used only for compression
+     * levels >= 4.
+     */
+#   define max_insert_length  max_lazy_match
+    /* Insert new strings in the hash table only if the match length is not
+     * greater than this length. This saves time but degrades compression.
+     * max_insert_length is used only for compression levels <= 3.
+     */
+
+    int level;    /* compression level (1..9) */
+    int strategy; /* favor or force Huffman coding*/
+
+    uInt good_match;
+    /* Use a faster search when the previous match is longer than this */
+
+    int nice_match; /* Stop searching when current match exceeds this */
+
+                /* used by trees.c: */
+    /* Didn't use ct_data typedef below to suppress compiler warning */
+    struct ct_data_s dyn_ltree[HEAP_SIZE];   /* literal and length tree */
+    struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
+    struct ct_data_s bl_tree[2*BL_CODES+1];  /* Huffman tree for bit lengths */
+
+    struct tree_desc_s l_desc;               /* desc. for literal tree */
+    struct tree_desc_s d_desc;               /* desc. for distance tree */
+    struct tree_desc_s bl_desc;              /* desc. for bit length tree */
+
+    ush bl_count[MAX_BITS+1];
+    /* number of codes at each bit length for an optimal tree */
+
+    int heap[2*L_CODES+1];      /* heap used to build the Huffman trees */
+    int heap_len;               /* number of elements in the heap */
+    int heap_max;               /* element of largest frequency */
+    /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
+     * The same heap array is used to build all trees.
+     */
+
+    uch depth[2*L_CODES+1];
+    /* Depth of each subtree used as tie breaker for trees of equal frequency
+     */
+
+    uchf *l_buf;          /* buffer for literals or lengths */
+
+    uInt  lit_bufsize;
+    /* Size of match buffer for literals/lengths.  There are 4 reasons for
+     * limiting lit_bufsize to 64K:
+     *   - frequencies can be kept in 16 bit counters
+     *   - if compression is not successful for the first block, all input
+     *     data is still in the window so we can still emit a stored block even
+     *     when input comes from standard input.  (This can also be done for
+     *     all blocks if lit_bufsize is not greater than 32K.)
+     *   - if compression is not successful for a file smaller than 64K, we can
+     *     even emit a stored file instead of a stored block (saving 5 bytes).
+     *     This is applicable only for zip (not gzip or zlib).
+     *   - creating new Huffman trees less frequently may not provide fast
+     *     adaptation to changes in the input data statistics. (Take for
+     *     example a binary file with poorly compressible code followed by
+     *     a highly compressible string table.) Smaller buffer sizes give
+     *     fast adaptation but have of course the overhead of transmitting
+     *     trees more frequently.
+     *   - I can't count above 4
+     */
+
+    uInt last_lit;      /* running index in l_buf */
+
+    ushf *d_buf;
+    /* Buffer for distances. To simplify the code, d_buf and l_buf have
+     * the same number of elements. To use different lengths, an extra flag
+     * array would be necessary.
+     */
+
+    ulg opt_len;        /* bit length of current block with optimal trees */
+    ulg static_len;     /* bit length of current block with static trees */
+    uInt matches;       /* number of string matches in current block */
+    uInt insert;        /* bytes at end of window left to insert */
+
+#ifdef ZLIB_DEBUG
+    ulg compressed_len; /* total bit length of compressed file mod 2^32 */
+    ulg bits_sent;      /* bit length of compressed data sent mod 2^32 */
+#endif
+
+    ush bi_buf;
+    /* Output buffer. bits are inserted starting at the bottom (least
+     * significant bits).
+     */
+    int bi_valid;
+    /* Number of valid bits in bi_buf.  All bits above the last valid bit
+     * are always zero.
+     */
+
+    ulg high_water;
+    /* High water mark offset in window for initialized bytes -- bytes above
+     * this are set to zero in order to avoid memory check warnings when
+     * longest match routines access bytes past the input.  This is then
+     * updated to the new high water mark.
+     */
+
+} FAR deflate_state;
+
+/* Output a byte on the stream.
+ * IN assertion: there is enough room in pending_buf.
+ */
+#define put_byte(s, c) {s->pending_buf[s->pending++] = (Bytef)(c);}
+
+
+#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
+/* Minimum amount of lookahead, except at the end of the input file.
+ * See deflate.c for comments about the MIN_MATCH+1.
+ */
+
+#define MAX_DIST(s)  ((s)->w_size-MIN_LOOKAHEAD)
+/* In order to simplify the code, particularly on 16 bit machines, match
+ * distances are limited to MAX_DIST instead of WSIZE.
+ */
+
+#define WIN_INIT MAX_MATCH
+/* Number of bytes after end of data in window to initialize in order to avoid
+   memory checker errors from longest match routines */
+
+        /* in trees.c */
+void ZLIB_INTERNAL _tr_init OF((deflate_state *s));
+int ZLIB_INTERNAL _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc));
+void ZLIB_INTERNAL _tr_flush_block OF((deflate_state *s, charf *buf,
+                        ulg stored_len, int last));
+void ZLIB_INTERNAL _tr_flush_bits OF((deflate_state *s));
+void ZLIB_INTERNAL _tr_align OF((deflate_state *s));
+void ZLIB_INTERNAL _tr_stored_block OF((deflate_state *s, charf *buf,
+                        ulg stored_len, int last));
+
+#define d_code(dist) \
+   ((dist) < 256 ? _dist_code[dist] : _dist_code[256+((dist)>>7)])
+/* Mapping from a distance to a distance code. dist is the distance - 1 and
+ * must not have side effects. _dist_code[256] and _dist_code[257] are never
+ * used.
+ */
+
+#ifndef ZLIB_DEBUG
+/* Inline versions of _tr_tally for speed: */
+
+#if defined(GEN_TREES_H) || !defined(STDC)
+  extern uch ZLIB_INTERNAL _length_code[];
+  extern uch ZLIB_INTERNAL _dist_code[];
+#else
+  extern const uch ZLIB_INTERNAL _length_code[];
+  extern const uch ZLIB_INTERNAL _dist_code[];
+#endif
+
+# define _tr_tally_lit(s, c, flush) \
+  { uch cc = (c); \
+    s->d_buf[s->last_lit] = 0; \
+    s->l_buf[s->last_lit++] = cc; \
+    s->dyn_ltree[cc].Freq++; \
+    flush = (s->last_lit == s->lit_bufsize-1); \
+   }
+# define _tr_tally_dist(s, distance, length, flush) \
+  { uch len = (uch)(length); \
+    ush dist = (ush)(distance); \
+    s->d_buf[s->last_lit] = dist; \
+    s->l_buf[s->last_lit++] = len; \
+    dist--; \
+    s->dyn_ltree[_length_code[len]+LITERALS+1].Freq++; \
+    s->dyn_dtree[d_code(dist)].Freq++; \
+    flush = (s->last_lit == s->lit_bufsize-1); \
+  }
+#else
+# define _tr_tally_lit(s, c, flush) flush = _tr_tally(s, 0, c)
+# define _tr_tally_dist(s, distance, length, flush) \
+              flush = _tr_tally(s, distance, length)
+#endif
+
+#endif /* DEFLATE_H */

vendor/libgit2-sys/libgit2/deps/zlib/gzguts.h

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/gzguts.h b/vendor/libgit2-sys/libgit2/deps/zlib/gzguts.h
new file mode 100644
index 0000000..990a4d2
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/gzguts.h
@@ -0,0 +1,218 @@
+/* gzguts.h -- zlib internal header definitions for gz* operations
+ * Copyright (C) 2004, 2005, 2010, 2011, 2012, 2013, 2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#ifdef _LARGEFILE64_SOURCE
+#  ifndef _LARGEFILE_SOURCE
+#    define _LARGEFILE_SOURCE 1
+#  endif
+#  ifdef _FILE_OFFSET_BITS
+#    undef _FILE_OFFSET_BITS
+#  endif
+#endif
+
+#ifdef HAVE_HIDDEN
+#  define ZLIB_INTERNAL __attribute__((visibility ("hidden")))
+#else
+#  define ZLIB_INTERNAL
+#endif
+
+#include <stdio.h>
+#include "zlib.h"
+#ifdef STDC
+#  include <string.h>
+#  include <stdlib.h>
+#  include <limits.h>
+#endif
+
+#ifndef _POSIX_SOURCE
+#  define _POSIX_SOURCE
+#endif
+#include <fcntl.h>
+
+#ifdef _WIN32
+#  include <stddef.h>
+#endif
+
+#if defined(__TURBOC__) || defined(_MSC_VER) || defined(_WIN32)
+#  include <io.h>
+#endif
+
+#if defined(_WIN32) || defined(__CYGWIN__)
+#  define WIDECHAR
+#endif
+
+#ifdef WINAPI_FAMILY
+#  define open _open
+#  define read _read
+#  define write _write
+#  define close _close
+#endif
+
+#ifdef NO_DEFLATE       /* for compatibility with old definition */
+#  define NO_GZCOMPRESS
+#endif
+
+#if defined(STDC99) || (defined(__TURBOC__) && __TURBOC__ >= 0x550)
+#  ifndef HAVE_VSNPRINTF
+#    define HAVE_VSNPRINTF
+#  endif
+#endif
+
+#if defined(__CYGWIN__)
+#  ifndef HAVE_VSNPRINTF
+#    define HAVE_VSNPRINTF
+#  endif
+#endif
+
+#if defined(MSDOS) && defined(__BORLANDC__) && (BORLANDC > 0x410)
+#  ifndef HAVE_VSNPRINTF
+#    define HAVE_VSNPRINTF
+#  endif
+#endif
+
+#ifndef HAVE_VSNPRINTF
+#  ifdef MSDOS
+/* vsnprintf may exist on some MS-DOS compilers (DJGPP?),
+   but for now we just assume it doesn't. */
+#    define NO_vsnprintf
+#  endif
+#  ifdef __TURBOC__
+#    define NO_vsnprintf
+#  endif
+#  ifdef WIN32
+/* In Win32, vsnprintf is available as the "non-ANSI" _vsnprintf. */
+#    if !defined(vsnprintf) && !defined(NO_vsnprintf)
+#      if !defined(_MSC_VER) || ( defined(_MSC_VER) && _MSC_VER < 1500 )
+#         define vsnprintf _vsnprintf
+#      endif
+#    endif
+#  endif
+#  ifdef __SASC
+#    define NO_vsnprintf
+#  endif
+#  ifdef VMS
+#    define NO_vsnprintf
+#  endif
+#  ifdef __OS400__
+#    define NO_vsnprintf
+#  endif
+#  ifdef __MVS__
+#    define NO_vsnprintf
+#  endif
+#endif
+
+/* unlike snprintf (which is required in C99), _snprintf does not guarantee
+   null termination of the result -- however this is only used in gzlib.c where
+   the result is assured to fit in the space provided */
+#if defined(_MSC_VER) && _MSC_VER < 1900
+#  define snprintf _snprintf
+#endif
+
+#ifndef local
+#  define local static
+#endif
+/* since "static" is used to mean two completely different things in C, we
+   define "local" for the non-static meaning of "static", for readability
+   (compile with -Dlocal if your debugger can't find static symbols) */
+
+/* gz* functions always use library allocation functions */
+#ifndef STDC
+  extern voidp  malloc OF((uInt size));
+  extern void   free   OF((voidpf ptr));
+#endif
+
+/* get errno and strerror definition */
+#if defined UNDER_CE
+#  include <windows.h>
+#  define zstrerror() gz_strwinerror((DWORD)GetLastError())
+#else
+#  ifndef NO_STRERROR
+#    include <errno.h>
+#    define zstrerror() strerror(errno)
+#  else
+#    define zstrerror() "stdio error (consult errno)"
+#  endif
+#endif
+
+/* provide prototypes for these when building zlib without LFS */
+#if !defined(_LARGEFILE64_SOURCE) || _LFS64_LARGEFILE-0 == 0
+    ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
+    ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
+    ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
+    ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
+#endif
+
+/* default memLevel */
+#if MAX_MEM_LEVEL >= 8
+#  define DEF_MEM_LEVEL 8
+#else
+#  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
+#endif
+
+/* default i/o buffer size -- double this for output when reading (this and
+   twice this must be able to fit in an unsigned type) */
+#define GZBUFSIZE 8192
+
+/* gzip modes, also provide a little integrity check on the passed structure */
+#define GZ_NONE 0
+#define GZ_READ 7247
+#define GZ_WRITE 31153
+#define GZ_APPEND 1     /* mode set to GZ_WRITE after the file is opened */
+
+/* values for gz_state how */
+#define LOOK 0      /* look for a gzip header */
+#define COPY 1      /* copy input directly */
+#define GZIP 2      /* decompress a gzip stream */
+
+/* internal gzip file state data structure */
+typedef struct {
+        /* exposed contents for gzgetc() macro */
+    struct gzFile_s x;      /* "x" for exposed */
+                            /* x.have: number of bytes available at x.next */
+                            /* x.next: next output data to deliver or write */
+                            /* x.pos: current position in uncompressed data */
+        /* used for both reading and writing */
+    int mode;               /* see gzip modes above */
+    int fd;                 /* file descriptor */
+    char *path;             /* path or fd for error messages */
+    unsigned size;          /* buffer size, zero if not allocated yet */
+    unsigned want;          /* requested buffer size, default is GZBUFSIZE */
+    unsigned char *in;      /* input buffer (double-sized when writing) */
+    unsigned char *out;     /* output buffer (double-sized when reading) */
+    int direct;             /* 0 if processing gzip, 1 if transparent */
+        /* just for reading */
+    int how;                /* 0: get header, 1: copy, 2: decompress */
+    z_off64_t start;        /* where the gzip data started, for rewinding */
+    int eof;                /* true if end of input file reached */
+    int past;               /* true if read requested past end */
+        /* just for writing */
+    int level;              /* compression level */
+    int strategy;           /* compression strategy */
+        /* seek request */
+    z_off64_t skip;         /* amount to skip (already rewound if backwards) */
+    int seek;               /* true if seek request pending */
+        /* error information */
+    int err;                /* error code */
+    char *msg;              /* error message */
+        /* zlib inflate or deflate stream */
+    z_stream strm;          /* stream structure in-place (not a pointer) */
+} gz_state;
+typedef gz_state FAR *gz_statep;
+
+/* shared functions */
+void ZLIB_INTERNAL gz_error OF((gz_statep, int, const char *));
+#if defined UNDER_CE
+char ZLIB_INTERNAL *gz_strwinerror OF((DWORD error));
+#endif
+
+/* GT_OFF(x), where x is an unsigned value, is true if x > maximum z_off64_t
+   value -- needed when comparing unsigned to z_off64_t, which is signed
+   (possible z_off64_t types off_t, off64_t, and long are all signed) */
+#ifdef INT_MAX
+#  define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > INT_MAX)
+#else
+unsigned ZLIB_INTERNAL gz_intmax OF((void));
+#  define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > gz_intmax())
+#endif

vendor/libgit2-sys/libgit2/deps/zlib/infback.c

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/infback.c b/vendor/libgit2-sys/libgit2/deps/zlib/infback.c
new file mode 100644
index 0000000..59679ec
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/infback.c
@@ -0,0 +1,640 @@
+/* infback.c -- inflate using a call-back interface
+ * Copyright (C) 1995-2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/*
+   This code is largely copied from inflate.c.  Normally either infback.o or
+   inflate.o would be linked into an application--not both.  The interface
+   with inffast.c is retained so that optimized assembler-coded versions of
+   inflate_fast() can be used with either inflate.c or infback.c.
+ */
+
+#include "zutil.h"
+#include "inftrees.h"
+#include "inflate.h"
+#include "inffast.h"
+
+/* function prototypes */
+local void fixedtables OF((struct inflate_state FAR *state));
+
+/*
+   strm provides memory allocation functions in zalloc and zfree, or
+   Z_NULL to use the library memory allocation functions.
+
+   windowBits is in the range 8..15, and window is a user-supplied
+   window and output buffer that is 2**windowBits bytes.
+ */
+int ZEXPORT inflateBackInit_(strm, windowBits, window, version, stream_size)
+z_streamp strm;
+int windowBits;
+unsigned char FAR *window;
+const char *version;
+int stream_size;
+{
+    struct inflate_state FAR *state;
+
+    if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
+        stream_size != (int)(sizeof(z_stream)))
+        return Z_VERSION_ERROR;
+    if (strm == Z_NULL || window == Z_NULL ||
+        windowBits < 8 || windowBits > 15)
+        return Z_STREAM_ERROR;
+    strm->msg = Z_NULL;                 /* in case we return an error */
+    if (strm->zalloc == (alloc_func)0) {
+#ifdef Z_SOLO
+        return Z_STREAM_ERROR;
+#else
+        strm->zalloc = zcalloc;
+        strm->opaque = (voidpf)0;
+#endif
+    }
+    if (strm->zfree == (free_func)0)
+#ifdef Z_SOLO
+        return Z_STREAM_ERROR;
+#else
+    strm->zfree = zcfree;
+#endif
+    state = (struct inflate_state FAR *)ZALLOC(strm, 1,
+                                               sizeof(struct inflate_state));
+    if (state == Z_NULL) return Z_MEM_ERROR;
+    Tracev((stderr, "inflate: allocated\n"));
+    strm->state = (struct internal_state FAR *)state;
+    state->dmax = 32768U;
+    state->wbits = (uInt)windowBits;
+    state->wsize = 1U << windowBits;
+    state->window = window;
+    state->wnext = 0;
+    state->whave = 0;
+    return Z_OK;
+}
+
+/*
+   Return state with length and distance decoding tables and index sizes set to
+   fixed code decoding.  Normally this returns fixed tables from inffixed.h.
+   If BUILDFIXED is defined, then instead this routine builds the tables the
+   first time it's called, and returns those tables the first time and
+   thereafter.  This reduces the size of the code by about 2K bytes, in
+   exchange for a little execution time.  However, BUILDFIXED should not be
+   used for threaded applications, since the rewriting of the tables and virgin
+   may not be thread-safe.
+ */
+local void fixedtables(state)
+struct inflate_state FAR *state;
+{
+#ifdef BUILDFIXED
+    static int virgin = 1;
+    static code *lenfix, *distfix;
+    static code fixed[544];
+
+    /* build fixed huffman tables if first call (may not be thread safe) */
+    if (virgin) {
+        unsigned sym, bits;
+        static code *next;
+
+        /* literal/length table */
+        sym = 0;
+        while (sym < 144) state->lens[sym++] = 8;
+        while (sym < 256) state->lens[sym++] = 9;
+        while (sym < 280) state->lens[sym++] = 7;
+        while (sym < 288) state->lens[sym++] = 8;
+        next = fixed;
+        lenfix = next;
+        bits = 9;
+        inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
+
+        /* distance table */
+        sym = 0;
+        while (sym < 32) state->lens[sym++] = 5;
+        distfix = next;
+        bits = 5;
+        inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
+
+        /* do this just once */
+        virgin = 0;
+    }
+#else /* !BUILDFIXED */
+#   include "inffixed.h"
+#endif /* BUILDFIXED */
+    state->lencode = lenfix;
+    state->lenbits = 9;
+    state->distcode = distfix;
+    state->distbits = 5;
+}
+
+/* Macros for inflateBack(): */
+
+/* Load returned state from inflate_fast() */
+#define LOAD() \
+    do { \
+        put = strm->next_out; \
+        left = strm->avail_out; \
+        next = strm->next_in; \
+        have = strm->avail_in; \
+        hold = state->hold; \
+        bits = state->bits; \
+    } while (0)
+
+/* Set state from registers for inflate_fast() */
+#define RESTORE() \
+    do { \
+        strm->next_out = put; \
+        strm->avail_out = left; \
+        strm->next_in = next; \
+        strm->avail_in = have; \
+        state->hold = hold; \
+        state->bits = bits; \
+    } while (0)
+
+/* Clear the input bit accumulator */
+#define INITBITS() \
+    do { \
+        hold = 0; \
+        bits = 0; \
+    } while (0)
+
+/* Assure that some input is available.  If input is requested, but denied,
+   then return a Z_BUF_ERROR from inflateBack(). */
+#define PULL() \
+    do { \
+        if (have == 0) { \
+            have = in(in_desc, &next); \
+            if (have == 0) { \
+                next = Z_NULL; \
+                ret = Z_BUF_ERROR; \
+                goto inf_leave; \
+            } \
+        } \
+    } while (0)
+
+/* Get a byte of input into the bit accumulator, or return from inflateBack()
+   with an error if there is no input available. */
+#define PULLBYTE() \
+    do { \
+        PULL(); \
+        have--; \
+        hold += (unsigned long)(*next++) << bits; \
+        bits += 8; \
+    } while (0)
+
+/* Assure that there are at least n bits in the bit accumulator.  If there is
+   not enough available input to do that, then return from inflateBack() with
+   an error. */
+#define NEEDBITS(n) \
+    do { \
+        while (bits < (unsigned)(n)) \
+            PULLBYTE(); \
+    } while (0)
+
+/* Return the low n bits of the bit accumulator (n < 16) */
+#define BITS(n) \
+    ((unsigned)hold & ((1U << (n)) - 1))
+
+/* Remove n bits from the bit accumulator */
+#define DROPBITS(n) \
+    do { \
+        hold >>= (n); \
+        bits -= (unsigned)(n); \
+    } while (0)
+
+/* Remove zero to seven bits as needed to go to a byte boundary */
+#define BYTEBITS() \
+    do { \
+        hold >>= bits & 7; \
+        bits -= bits & 7; \
+    } while (0)
+
+/* Assure that some output space is available, by writing out the window
+   if it's full.  If the write fails, return from inflateBack() with a
+   Z_BUF_ERROR. */
+#define ROOM() \
+    do { \
+        if (left == 0) { \
+            put = state->window; \
+            left = state->wsize; \
+            state->whave = left; \
+            if (out(out_desc, put, left)) { \
+                ret = Z_BUF_ERROR; \
+                goto inf_leave; \
+            } \
+        } \
+    } while (0)
+
+/*
+   strm provides the memory allocation functions and window buffer on input,
+   and provides information on the unused input on return.  For Z_DATA_ERROR
+   returns, strm will also provide an error message.
+
+   in() and out() are the call-back input and output functions.  When
+   inflateBack() needs more input, it calls in().  When inflateBack() has
+   filled the window with output, or when it completes with data in the
+   window, it calls out() to write out the data.  The application must not
+   change the provided input until in() is called again or inflateBack()
+   returns.  The application must not change the window/output buffer until
+   inflateBack() returns.
+
+   in() and out() are called with a descriptor parameter provided in the
+   inflateBack() call.  This parameter can be a structure that provides the
+   information required to do the read or write, as well as accumulated
+   information on the input and output such as totals and check values.
+
+   in() should return zero on failure.  out() should return non-zero on
+   failure.  If either in() or out() fails, than inflateBack() returns a
+   Z_BUF_ERROR.  strm->next_in can be checked for Z_NULL to see whether it
+   was in() or out() that caused in the error.  Otherwise,  inflateBack()
+   returns Z_STREAM_END on success, Z_DATA_ERROR for an deflate format
+   error, or Z_MEM_ERROR if it could not allocate memory for the state.
+   inflateBack() can also return Z_STREAM_ERROR if the input parameters
+   are not correct, i.e. strm is Z_NULL or the state was not initialized.
+ */
+int ZEXPORT inflateBack(strm, in, in_desc, out, out_desc)
+z_streamp strm;
+in_func in;
+void FAR *in_desc;
+out_func out;
+void FAR *out_desc;
+{
+    struct inflate_state FAR *state;
+    z_const unsigned char FAR *next;    /* next input */
+    unsigned char FAR *put;     /* next output */
+    unsigned have, left;        /* available input and output */
+    unsigned long hold;         /* bit buffer */
+    unsigned bits;              /* bits in bit buffer */
+    unsigned copy;              /* number of stored or match bytes to copy */
+    unsigned char FAR *from;    /* where to copy match bytes from */
+    code here;                  /* current decoding table entry */
+    code last;                  /* parent table entry */
+    unsigned len;               /* length to copy for repeats, bits to drop */
+    int ret;                    /* return code */
+    static const unsigned short order[19] = /* permutation of code lengths */
+        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+    /* Check that the strm exists and that the state was initialized */
+    if (strm == Z_NULL || strm->state == Z_NULL)
+        return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+
+    /* Reset the state */
+    strm->msg = Z_NULL;
+    state->mode = TYPE;
+    state->last = 0;
+    state->whave = 0;
+    next = strm->next_in;
+    have = next != Z_NULL ? strm->avail_in : 0;
+    hold = 0;
+    bits = 0;
+    put = state->window;
+    left = state->wsize;
+
+    /* Inflate until end of block marked as last */
+    for (;;)
+        switch (state->mode) {
+        case TYPE:
+            /* determine and dispatch block type */
+            if (state->last) {
+                BYTEBITS();
+                state->mode = DONE;
+                break;
+            }
+            NEEDBITS(3);
+            state->last = BITS(1);
+            DROPBITS(1);
+            switch (BITS(2)) {
+            case 0:                             /* stored block */
+                Tracev((stderr, "inflate:     stored block%s\n",
+                        state->last ? " (last)" : ""));
+                state->mode = STORED;
+                break;
+            case 1:                             /* fixed block */
+                fixedtables(state);
+                Tracev((stderr, "inflate:     fixed codes block%s\n",
+                        state->last ? " (last)" : ""));
+                state->mode = LEN;              /* decode codes */
+                break;
+            case 2:                             /* dynamic block */
+                Tracev((stderr, "inflate:     dynamic codes block%s\n",
+                        state->last ? " (last)" : ""));
+                state->mode = TABLE;
+                break;
+            case 3:
+                strm->msg = (char *)"invalid block type";
+                state->mode = BAD;
+            }
+            DROPBITS(2);
+            break;
+
+        case STORED:
+            /* get and verify stored block length */
+            BYTEBITS();                         /* go to byte boundary */
+            NEEDBITS(32);
+            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
+                strm->msg = (char *)"invalid stored block lengths";
+                state->mode = BAD;
+                break;
+            }
+            state->length = (unsigned)hold & 0xffff;
+            Tracev((stderr, "inflate:       stored length %u\n",
+                    state->length));
+            INITBITS();
+
+            /* copy stored block from input to output */
+            while (state->length != 0) {
+                copy = state->length;
+                PULL();
+                ROOM();
+                if (copy > have) copy = have;
+                if (copy > left) copy = left;
+                zmemcpy(put, next, copy);
+                have -= copy;
+                next += copy;
+                left -= copy;
+                put += copy;
+                state->length -= copy;
+            }
+            Tracev((stderr, "inflate:       stored end\n"));
+            state->mode = TYPE;
+            break;
+
+        case TABLE:
+            /* get dynamic table entries descriptor */
+            NEEDBITS(14);
+            state->nlen = BITS(5) + 257;
+            DROPBITS(5);
+            state->ndist = BITS(5) + 1;
+            DROPBITS(5);
+            state->ncode = BITS(4) + 4;
+            DROPBITS(4);
+#ifndef PKZIP_BUG_WORKAROUND
+            if (state->nlen > 286 || state->ndist > 30) {
+                strm->msg = (char *)"too many length or distance symbols";
+                state->mode = BAD;
+                break;
+            }
+#endif
+            Tracev((stderr, "inflate:       table sizes ok\n"));
+
+            /* get code length code lengths (not a typo) */
+            state->have = 0;
+            while (state->have < state->ncode) {
+                NEEDBITS(3);
+                state->lens[order[state->have++]] = (unsigned short)BITS(3);
+                DROPBITS(3);
+            }
+            while (state->have < 19)
+                state->lens[order[state->have++]] = 0;
+            state->next = state->codes;
+            state->lencode = (code const FAR *)(state->next);
+            state->lenbits = 7;
+            ret = inflate_table(CODES, state->lens, 19, &(state->next),
+                                &(state->lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid code lengths set";
+                state->mode = BAD;
+                break;
+            }
+            Tracev((stderr, "inflate:       code lengths ok\n"));
+
+            /* get length and distance code code lengths */
+            state->have = 0;
+            while (state->have < state->nlen + state->ndist) {
+                for (;;) {
+                    here = state->lencode[BITS(state->lenbits)];
+                    if ((unsigned)(here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                if (here.val < 16) {
+                    DROPBITS(here.bits);
+                    state->lens[state->have++] = here.val;
+                }
+                else {
+                    if (here.val == 16) {
+                        NEEDBITS(here.bits + 2);
+                        DROPBITS(here.bits);
+                        if (state->have == 0) {
+                            strm->msg = (char *)"invalid bit length repeat";
+                            state->mode = BAD;
+                            break;
+                        }
+                        len = (unsigned)(state->lens[state->have - 1]);
+                        copy = 3 + BITS(2);
+                        DROPBITS(2);
+                    }
+                    else if (here.val == 17) {
+                        NEEDBITS(here.bits + 3);
+                        DROPBITS(here.bits);
+                        len = 0;
+                        copy = 3 + BITS(3);
+                        DROPBITS(3);
+                    }
+                    else {
+                        NEEDBITS(here.bits + 7);
+                        DROPBITS(here.bits);
+                        len = 0;
+                        copy = 11 + BITS(7);
+                        DROPBITS(7);
+                    }
+                    if (state->have + copy > state->nlen + state->ndist) {
+                        strm->msg = (char *)"invalid bit length repeat";
+                        state->mode = BAD;
+                        break;
+                    }
+                    while (copy--)
+                        state->lens[state->have++] = (unsigned short)len;
+                }
+            }
+
+            /* handle error breaks in while */
+            if (state->mode == BAD) break;
+
+            /* check for end-of-block code (better have one) */
+            if (state->lens[256] == 0) {
+                strm->msg = (char *)"invalid code -- missing end-of-block";
+                state->mode = BAD;
+                break;
+            }
+
+            /* build code tables -- note: do not change the lenbits or distbits
+               values here (9 and 6) without reading the comments in inftrees.h
+               concerning the ENOUGH constants, which depend on those values */
+            state->next = state->codes;
+            state->lencode = (code const FAR *)(state->next);
+            state->lenbits = 9;
+            ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
+                                &(state->lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid literal/lengths set";
+                state->mode = BAD;
+                break;
+            }
+            state->distcode = (code const FAR *)(state->next);
+            state->distbits = 6;
+            ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
+                            &(state->next), &(state->distbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid distances set";
+                state->mode = BAD;
+                break;
+            }
+            Tracev((stderr, "inflate:       codes ok\n"));
+            state->mode = LEN;
+
+        case LEN:
+            /* use inflate_fast() if we have enough input and output */
+            if (have >= 6 && left >= 258) {
+                RESTORE();
+                if (state->whave < state->wsize)
+                    state->whave = state->wsize - left;
+                inflate_fast(strm, state->wsize);
+                LOAD();
+                break;
+            }
+
+            /* get a literal, length, or end-of-block code */
+            for (;;) {
+                here = state->lencode[BITS(state->lenbits)];
+                if ((unsigned)(here.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if (here.op && (here.op & 0xf0) == 0) {
+                last = here;
+                for (;;) {
+                    here = state->lencode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+            }
+            DROPBITS(here.bits);
+            state->length = (unsigned)here.val;
+
+            /* process literal */
+            if (here.op == 0) {
+                Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
+                        "inflate:         literal '%c'\n" :
+                        "inflate:         literal 0x%02x\n", here.val));
+                ROOM();
+                *put++ = (unsigned char)(state->length);
+                left--;
+                state->mode = LEN;
+                break;
+            }
+
+            /* process end of block */
+            if (here.op & 32) {
+                Tracevv((stderr, "inflate:         end of block\n"));
+                state->mode = TYPE;
+                break;
+            }
+
+            /* invalid code */
+            if (here.op & 64) {
+                strm->msg = (char *)"invalid literal/length code";
+                state->mode = BAD;
+                break;
+            }
+
+            /* length code -- get extra bits, if any */
+            state->extra = (unsigned)(here.op) & 15;
+            if (state->extra != 0) {
+                NEEDBITS(state->extra);
+                state->length += BITS(state->extra);
+                DROPBITS(state->extra);
+            }
+            Tracevv((stderr, "inflate:         length %u\n", state->length));
+
+            /* get distance code */
+            for (;;) {
+                here = state->distcode[BITS(state->distbits)];
+                if ((unsigned)(here.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if ((here.op & 0xf0) == 0) {
+                last = here;
+                for (;;) {
+                    here = state->distcode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+            }
+            DROPBITS(here.bits);
+            if (here.op & 64) {
+                strm->msg = (char *)"invalid distance code";
+                state->mode = BAD;
+                break;
+            }
+            state->offset = (unsigned)here.val;
+
+            /* get distance extra bits, if any */
+            state->extra = (unsigned)(here.op) & 15;
+            if (state->extra != 0) {
+                NEEDBITS(state->extra);
+                state->offset += BITS(state->extra);
+                DROPBITS(state->extra);
+            }
+            if (state->offset > state->wsize - (state->whave < state->wsize ?
+                                                left : 0)) {
+                strm->msg = (char *)"invalid distance too far back";
+                state->mode = BAD;
+                break;
+            }
+            Tracevv((stderr, "inflate:         distance %u\n", state->offset));
+
+            /* copy match from window to output */
+            do {
+                ROOM();
+                copy = state->wsize - state->offset;
+                if (copy < left) {
+                    from = put + copy;
+                    copy = left - copy;
+                }
+                else {
+                    from = put - state->offset;
+                    copy = left;
+                }
+                if (copy > state->length) copy = state->length;
+                state->length -= copy;
+                left -= copy;
+                do {
+                    *put++ = *from++;
+                } while (--copy);
+            } while (state->length != 0);
+            break;
+
+        case DONE:
+            /* inflate stream terminated properly -- write leftover output */
+            ret = Z_STREAM_END;
+            if (left < state->wsize) {
+                if (out(out_desc, state->window, state->wsize - left))
+                    ret = Z_BUF_ERROR;
+            }
+            goto inf_leave;
+
+        case BAD:
+            ret = Z_DATA_ERROR;
+            goto inf_leave;
+
+        default:                /* can't happen, but makes compilers happy */
+            ret = Z_STREAM_ERROR;
+            goto inf_leave;
+        }
+
+    /* Return unused input */
+  inf_leave:
+    strm->next_in = next;
+    strm->avail_in = have;
+    return ret;
+}
+
+int ZEXPORT inflateBackEnd(strm)
+z_streamp strm;
+{
+    if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
+        return Z_STREAM_ERROR;
+    ZFREE(strm, strm->state);
+    strm->state = Z_NULL;
+    Tracev((stderr, "inflate: end\n"));
+    return Z_OK;
+}

vendor/libgit2-sys/libgit2/deps/zlib/inffast.c

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/inffast.c b/vendor/libgit2-sys/libgit2/deps/zlib/inffast.c
new file mode 100644
index 0000000..0dbd1db
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/inffast.c
@@ -0,0 +1,323 @@
+/* inffast.c -- fast decoding
+ * Copyright (C) 1995-2017 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "zutil.h"
+#include "inftrees.h"
+#include "inflate.h"
+#include "inffast.h"
+
+#ifdef ASMINF
+#  pragma message("Assembler code may have bugs -- use at your own risk")
+#else
+
+/*
+   Decode literal, length, and distance codes and write out the resulting
+   literal and match bytes until either not enough input or output is
+   available, an end-of-block is encountered, or a data error is encountered.
+   When large enough input and output buffers are supplied to inflate(), for
+   example, a 16K input buffer and a 64K output buffer, more than 95% of the
+   inflate execution time is spent in this routine.
+
+   Entry assumptions:
+
+        state->mode == LEN
+        strm->avail_in >= 6
+        strm->avail_out >= 258
+        start >= strm->avail_out
+        state->bits < 8
+
+   On return, state->mode is one of:
+
+        LEN -- ran out of enough output space or enough available input
+        TYPE -- reached end of block code, inflate() to interpret next block
+        BAD -- error in block data
+
+   Notes:
+
+    - The maximum input bits used by a length/distance pair is 15 bits for the
+      length code, 5 bits for the length extra, 15 bits for the distance code,
+      and 13 bits for the distance extra.  This totals 48 bits, or six bytes.
+      Therefore if strm->avail_in >= 6, then there is enough input to avoid
+      checking for available input while decoding.
+
+    - The maximum bytes that a single length/distance pair can output is 258
+      bytes, which is the maximum length that can be coded.  inflate_fast()
+      requires strm->avail_out >= 258 for each loop to avoid checking for
+      output space.
+ */
+void ZLIB_INTERNAL inflate_fast(strm, start)
+z_streamp strm;
+unsigned start;         /* inflate()'s starting value for strm->avail_out */
+{
+    struct inflate_state FAR *state;
+    z_const unsigned char FAR *in;      /* local strm->next_in */
+    z_const unsigned char FAR *last;    /* have enough input while in < last */
+    unsigned char FAR *out;     /* local strm->next_out */
+    unsigned char FAR *beg;     /* inflate()'s initial strm->next_out */
+    unsigned char FAR *end;     /* while out < end, enough space available */
+#ifdef INFLATE_STRICT
+    unsigned dmax;              /* maximum distance from zlib header */
+#endif
+    unsigned wsize;             /* window size or zero if not using window */
+    unsigned whave;             /* valid bytes in the window */
+    unsigned wnext;             /* window write index */
+    unsigned char FAR *window;  /* allocated sliding window, if wsize != 0 */
+    unsigned long hold;         /* local strm->hold */
+    unsigned bits;              /* local strm->bits */
+    code const FAR *lcode;      /* local strm->lencode */
+    code const FAR *dcode;      /* local strm->distcode */
+    unsigned lmask;             /* mask for first level of length codes */
+    unsigned dmask;             /* mask for first level of distance codes */
+    code here;                  /* retrieved table entry */
+    unsigned op;                /* code bits, operation, extra bits, or */
+                                /*  window position, window bytes to copy */
+    unsigned len;               /* match length, unused bytes */
+    unsigned dist;              /* match distance */
+    unsigned char FAR *from;    /* where to copy match from */
+
+    /* copy state to local variables */
+    state = (struct inflate_state FAR *)strm->state;
+    in = strm->next_in;
+    last = in + (strm->avail_in - 5);
+    out = strm->next_out;
+    beg = out - (start - strm->avail_out);
+    end = out + (strm->avail_out - 257);
+#ifdef INFLATE_STRICT
+    dmax = state->dmax;
+#endif
+    wsize = state->wsize;
+    whave = state->whave;
+    wnext = state->wnext;
+    window = state->window;
+    hold = state->hold;
+    bits = state->bits;
+    lcode = state->lencode;
+    dcode = state->distcode;
+    lmask = (1U << state->lenbits) - 1;
+    dmask = (1U << state->distbits) - 1;
+
+    /* decode literals and length/distances until end-of-block or not enough
+       input data or output space */
+    do {
+        if (bits < 15) {
+            hold += (unsigned long)(*in++) << bits;
+            bits += 8;
+            hold += (unsigned long)(*in++) << bits;
+            bits += 8;
+        }
+        here = lcode[hold & lmask];
+      dolen:
+        op = (unsigned)(here.bits);
+        hold >>= op;
+        bits -= op;
+        op = (unsigned)(here.op);
+        if (op == 0) {                          /* literal */
+            Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
+                    "inflate:         literal '%c'\n" :
+                    "inflate:         literal 0x%02x\n", here.val));
+            *out++ = (unsigned char)(here.val);
+        }
+        else if (op & 16) {                     /* length base */
+            len = (unsigned)(here.val);
+            op &= 15;                           /* number of extra bits */
+            if (op) {
+                if (bits < op) {
+                    hold += (unsigned long)(*in++) << bits;
+                    bits += 8;
+                }
+                len += (unsigned)hold & ((1U << op) - 1);
+                hold >>= op;
+                bits -= op;
+            }
+            Tracevv((stderr, "inflate:         length %u\n", len));
+            if (bits < 15) {
+                hold += (unsigned long)(*in++) << bits;
+                bits += 8;
+                hold += (unsigned long)(*in++) << bits;
+                bits += 8;
+            }
+            here = dcode[hold & dmask];
+          dodist:
+            op = (unsigned)(here.bits);
+            hold >>= op;
+            bits -= op;
+            op = (unsigned)(here.op);
+            if (op & 16) {                      /* distance base */
+                dist = (unsigned)(here.val);
+                op &= 15;                       /* number of extra bits */
+                if (bits < op) {
+                    hold += (unsigned long)(*in++) << bits;
+                    bits += 8;
+                    if (bits < op) {
+                        hold += (unsigned long)(*in++) << bits;
+                        bits += 8;
+                    }
+                }
+                dist += (unsigned)hold & ((1U << op) - 1);
+#ifdef INFLATE_STRICT
+                if (dist > dmax) {
+                    strm->msg = (char *)"invalid distance too far back";
+                    state->mode = BAD;
+                    break;
+                }
+#endif
+                hold >>= op;
+                bits -= op;
+                Tracevv((stderr, "inflate:         distance %u\n", dist));
+                op = (unsigned)(out - beg);     /* max distance in output */
+                if (dist > op) {                /* see if copy from window */
+                    op = dist - op;             /* distance back in window */
+                    if (op > whave) {
+                        if (state->sane) {
+                            strm->msg =
+                                (char *)"invalid distance too far back";
+                            state->mode = BAD;
+                            break;
+                        }
+#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
+                        if (len <= op - whave) {
+                            do {
+                                *out++ = 0;
+                            } while (--len);
+                            continue;
+                        }
+                        len -= op - whave;
+                        do {
+                            *out++ = 0;
+                        } while (--op > whave);
+                        if (op == 0) {
+                            from = out - dist;
+                            do {
+                                *out++ = *from++;
+                            } while (--len);
+                            continue;
+                        }
+#endif
+                    }
+                    from = window;
+                    if (wnext == 0) {           /* very common case */
+                        from += wsize - op;
+                        if (op < len) {         /* some from window */
+                            len -= op;
+                            do {
+                                *out++ = *from++;
+                            } while (--op);
+                            from = out - dist;  /* rest from output */
+                        }
+                    }
+                    else if (wnext < op) {      /* wrap around window */
+                        from += wsize + wnext - op;
+                        op -= wnext;
+                        if (op < len) {         /* some from end of window */
+                            len -= op;
+                            do {
+                                *out++ = *from++;
+                            } while (--op);
+                            from = window;
+                            if (wnext < len) {  /* some from start of window */
+                                op = wnext;
+                                len -= op;
+                                do {
+                                    *out++ = *from++;
+                                } while (--op);
+                                from = out - dist;      /* rest from output */
+                            }
+                        }
+                    }
+                    else {                      /* contiguous in window */
+                        from += wnext - op;
+                        if (op < len) {         /* some from window */
+                            len -= op;
+                            do {
+                                *out++ = *from++;
+                            } while (--op);
+                            from = out - dist;  /* rest from output */
+                        }
+                    }
+                    while (len > 2) {
+                        *out++ = *from++;
+                        *out++ = *from++;
+                        *out++ = *from++;
+                        len -= 3;
+                    }
+                    if (len) {
+                        *out++ = *from++;
+                        if (len > 1)
+                            *out++ = *from++;
+                    }
+                }
+                else {
+                    from = out - dist;          /* copy direct from output */
+                    do {                        /* minimum length is three */
+                        *out++ = *from++;
+                        *out++ = *from++;
+                        *out++ = *from++;
+                        len -= 3;
+                    } while (len > 2);
+                    if (len) {
+                        *out++ = *from++;
+                        if (len > 1)
+                            *out++ = *from++;
+                    }
+                }
+            }
+            else if ((op & 64) == 0) {          /* 2nd level distance code */
+                here = dcode[here.val + (hold & ((1U << op) - 1))];
+                goto dodist;
+            }
+            else {
+                strm->msg = (char *)"invalid distance code";
+                state->mode = BAD;
+                break;
+            }
+        }
+        else if ((op & 64) == 0) {              /* 2nd level length code */
+            here = lcode[here.val + (hold & ((1U << op) - 1))];
+            goto dolen;
+        }
+        else if (op & 32) {                     /* end-of-block */
+            Tracevv((stderr, "inflate:         end of block\n"));
+            state->mode = TYPE;
+            break;
+        }
+        else {
+            strm->msg = (char *)"invalid literal/length code";
+            state->mode = BAD;
+            break;
+        }
+    } while (in < last && out < end);
+
+    /* return unused bytes (on entry, bits < 8, so in won't go too far back) */
+    len = bits >> 3;
+    in -= len;
+    bits -= len << 3;
+    hold &= (1U << bits) - 1;
+
+    /* update state and return */
+    strm->next_in = in;
+    strm->next_out = out;
+    strm->avail_in = (unsigned)(in < last ? 5 + (last - in) : 5 - (in - last));
+    strm->avail_out = (unsigned)(out < end ?
+                                 257 + (end - out) : 257 - (out - end));
+    state->hold = hold;
+    state->bits = bits;
+    return;
+}
+
+/*
+   inflate_fast() speedups that turned out slower (on a PowerPC G3 750CXe):
+   - Using bit fields for code structure
+   - Different op definition to avoid & for extra bits (do & for table bits)
+   - Three separate decoding do-loops for direct, window, and wnext == 0
+   - Special case for distance > 1 copies to do overlapped load and store copy
+   - Explicit branch predictions (based on measured branch probabilities)
+   - Deferring match copy and interspersed it with decoding subsequent codes
+   - Swapping literal/length else
+   - Swapping window/direct else
+   - Larger unrolled copy loops (three is about right)
+   - Moving len -= 3 statement into middle of loop
+ */
+
+#endif /* !ASMINF */

vendor/libgit2-sys/libgit2/deps/zlib/inffast.h

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/inffast.h b/vendor/libgit2-sys/libgit2/deps/zlib/inffast.h
new file mode 100644
index 0000000..e5c1aa4
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/inffast.h
@@ -0,0 +1,11 @@
+/* inffast.h -- header to use inffast.c
+ * Copyright (C) 1995-2003, 2010 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+void ZLIB_INTERNAL inflate_fast OF((z_streamp strm, unsigned start));

vendor/libgit2-sys/libgit2/deps/zlib/inffixed.h

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/inffixed.h b/vendor/libgit2-sys/libgit2/deps/zlib/inffixed.h
new file mode 100644
index 0000000..d628327
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/inffixed.h
@@ -0,0 +1,94 @@
+    /* inffixed.h -- table for decoding fixed codes
+     * Generated automatically by makefixed().
+     */
+
+    /* WARNING: this file should *not* be used by applications.
+       It is part of the implementation of this library and is
+       subject to change. Applications should only use zlib.h.
+     */
+
+    static const code lenfix[512] = {
+        {96,7,0},{0,8,80},{0,8,16},{20,8,115},{18,7,31},{0,8,112},{0,8,48},
+        {0,9,192},{16,7,10},{0,8,96},{0,8,32},{0,9,160},{0,8,0},{0,8,128},
+        {0,8,64},{0,9,224},{16,7,6},{0,8,88},{0,8,24},{0,9,144},{19,7,59},
+        {0,8,120},{0,8,56},{0,9,208},{17,7,17},{0,8,104},{0,8,40},{0,9,176},
+        {0,8,8},{0,8,136},{0,8,72},{0,9,240},{16,7,4},{0,8,84},{0,8,20},
+        {21,8,227},{19,7,43},{0,8,116},{0,8,52},{0,9,200},{17,7,13},{0,8,100},
+        {0,8,36},{0,9,168},{0,8,4},{0,8,132},{0,8,68},{0,9,232},{16,7,8},
+        {0,8,92},{0,8,28},{0,9,152},{20,7,83},{0,8,124},{0,8,60},{0,9,216},
+        {18,7,23},{0,8,108},{0,8,44},{0,9,184},{0,8,12},{0,8,140},{0,8,76},
+        {0,9,248},{16,7,3},{0,8,82},{0,8,18},{21,8,163},{19,7,35},{0,8,114},
+        {0,8,50},{0,9,196},{17,7,11},{0,8,98},{0,8,34},{0,9,164},{0,8,2},
+        {0,8,130},{0,8,66},{0,9,228},{16,7,7},{0,8,90},{0,8,26},{0,9,148},
+        {20,7,67},{0,8,122},{0,8,58},{0,9,212},{18,7,19},{0,8,106},{0,8,42},
+        {0,9,180},{0,8,10},{0,8,138},{0,8,74},{0,9,244},{16,7,5},{0,8,86},
+        {0,8,22},{64,8,0},{19,7,51},{0,8,118},{0,8,54},{0,9,204},{17,7,15},
+        {0,8,102},{0,8,38},{0,9,172},{0,8,6},{0,8,134},{0,8,70},{0,9,236},
+        {16,7,9},{0,8,94},{0,8,30},{0,9,156},{20,7,99},{0,8,126},{0,8,62},
+        {0,9,220},{18,7,27},{0,8,110},{0,8,46},{0,9,188},{0,8,14},{0,8,142},
+        {0,8,78},{0,9,252},{96,7,0},{0,8,81},{0,8,17},{21,8,131},{18,7,31},
+        {0,8,113},{0,8,49},{0,9,194},{16,7,10},{0,8,97},{0,8,33},{0,9,162},
+        {0,8,1},{0,8,129},{0,8,65},{0,9,226},{16,7,6},{0,8,89},{0,8,25},
+        {0,9,146},{19,7,59},{0,8,121},{0,8,57},{0,9,210},{17,7,17},{0,8,105},
+        {0,8,41},{0,9,178},{0,8,9},{0,8,137},{0,8,73},{0,9,242},{16,7,4},
+        {0,8,85},{0,8,21},{16,8,258},{19,7,43},{0,8,117},{0,8,53},{0,9,202},
+        {17,7,13},{0,8,101},{0,8,37},{0,9,170},{0,8,5},{0,8,133},{0,8,69},
+        {0,9,234},{16,7,8},{0,8,93},{0,8,29},{0,9,154},{20,7,83},{0,8,125},
+        {0,8,61},{0,9,218},{18,7,23},{0,8,109},{0,8,45},{0,9,186},{0,8,13},
+        {0,8,141},{0,8,77},{0,9,250},{16,7,3},{0,8,83},{0,8,19},{21,8,195},
+        {19,7,35},{0,8,115},{0,8,51},{0,9,198},{17,7,11},{0,8,99},{0,8,35},
+        {0,9,166},{0,8,3},{0,8,131},{0,8,67},{0,9,230},{16,7,7},{0,8,91},
+        {0,8,27},{0,9,150},{20,7,67},{0,8,123},{0,8,59},{0,9,214},{18,7,19},
+        {0,8,107},{0,8,43},{0,9,182},{0,8,11},{0,8,139},{0,8,75},{0,9,246},
+        {16,7,5},{0,8,87},{0,8,23},{64,8,0},{19,7,51},{0,8,119},{0,8,55},
+        {0,9,206},{17,7,15},{0,8,103},{0,8,39},{0,9,174},{0,8,7},{0,8,135},
+        {0,8,71},{0,9,238},{16,7,9},{0,8,95},{0,8,31},{0,9,158},{20,7,99},
+        {0,8,127},{0,8,63},{0,9,222},{18,7,27},{0,8,111},{0,8,47},{0,9,190},
+        {0,8,15},{0,8,143},{0,8,79},{0,9,254},{96,7,0},{0,8,80},{0,8,16},
+        {20,8,115},{18,7,31},{0,8,112},{0,8,48},{0,9,193},{16,7,10},{0,8,96},
+        {0,8,32},{0,9,161},{0,8,0},{0,8,128},{0,8,64},{0,9,225},{16,7,6},
+        {0,8,88},{0,8,24},{0,9,145},{19,7,59},{0,8,120},{0,8,56},{0,9,209},
+        {17,7,17},{0,8,104},{0,8,40},{0,9,177},{0,8,8},{0,8,136},{0,8,72},
+        {0,9,241},{16,7,4},{0,8,84},{0,8,20},{21,8,227},{19,7,43},{0,8,116},
+        {0,8,52},{0,9,201},{17,7,13},{0,8,100},{0,8,36},{0,9,169},{0,8,4},
+        {0,8,132},{0,8,68},{0,9,233},{16,7,8},{0,8,92},{0,8,28},{0,9,153},
+        {20,7,83},{0,8,124},{0,8,60},{0,9,217},{18,7,23},{0,8,108},{0,8,44},
+        {0,9,185},{0,8,12},{0,8,140},{0,8,76},{0,9,249},{16,7,3},{0,8,82},
+        {0,8,18},{21,8,163},{19,7,35},{0,8,114},{0,8,50},{0,9,197},{17,7,11},
+        {0,8,98},{0,8,34},{0,9,165},{0,8,2},{0,8,130},{0,8,66},{0,9,229},
+        {16,7,7},{0,8,90},{0,8,26},{0,9,149},{20,7,67},{0,8,122},{0,8,58},
+        {0,9,213},{18,7,19},{0,8,106},{0,8,42},{0,9,181},{0,8,10},{0,8,138},
+        {0,8,74},{0,9,245},{16,7,5},{0,8,86},{0,8,22},{64,8,0},{19,7,51},
+        {0,8,118},{0,8,54},{0,9,205},{17,7,15},{0,8,102},{0,8,38},{0,9,173},
+        {0,8,6},{0,8,134},{0,8,70},{0,9,237},{16,7,9},{0,8,94},{0,8,30},
+        {0,9,157},{20,7,99},{0,8,126},{0,8,62},{0,9,221},{18,7,27},{0,8,110},
+        {0,8,46},{0,9,189},{0,8,14},{0,8,142},{0,8,78},{0,9,253},{96,7,0},
+        {0,8,81},{0,8,17},{21,8,131},{18,7,31},{0,8,113},{0,8,49},{0,9,195},
+        {16,7,10},{0,8,97},{0,8,33},{0,9,163},{0,8,1},{0,8,129},{0,8,65},
+        {0,9,227},{16,7,6},{0,8,89},{0,8,25},{0,9,147},{19,7,59},{0,8,121},
+        {0,8,57},{0,9,211},{17,7,17},{0,8,105},{0,8,41},{0,9,179},{0,8,9},
+        {0,8,137},{0,8,73},{0,9,243},{16,7,4},{0,8,85},{0,8,21},{16,8,258},
+        {19,7,43},{0,8,117},{0,8,53},{0,9,203},{17,7,13},{0,8,101},{0,8,37},
+        {0,9,171},{0,8,5},{0,8,133},{0,8,69},{0,9,235},{16,7,8},{0,8,93},
+        {0,8,29},{0,9,155},{20,7,83},{0,8,125},{0,8,61},{0,9,219},{18,7,23},
+        {0,8,109},{0,8,45},{0,9,187},{0,8,13},{0,8,141},{0,8,77},{0,9,251},
+        {16,7,3},{0,8,83},{0,8,19},{21,8,195},{19,7,35},{0,8,115},{0,8,51},
+        {0,9,199},{17,7,11},{0,8,99},{0,8,35},{0,9,167},{0,8,3},{0,8,131},
+        {0,8,67},{0,9,231},{16,7,7},{0,8,91},{0,8,27},{0,9,151},{20,7,67},
+        {0,8,123},{0,8,59},{0,9,215},{18,7,19},{0,8,107},{0,8,43},{0,9,183},
+        {0,8,11},{0,8,139},{0,8,75},{0,9,247},{16,7,5},{0,8,87},{0,8,23},
+        {64,8,0},{19,7,51},{0,8,119},{0,8,55},{0,9,207},{17,7,15},{0,8,103},
+        {0,8,39},{0,9,175},{0,8,7},{0,8,135},{0,8,71},{0,9,239},{16,7,9},
+        {0,8,95},{0,8,31},{0,9,159},{20,7,99},{0,8,127},{0,8,63},{0,9,223},
+        {18,7,27},{0,8,111},{0,8,47},{0,9,191},{0,8,15},{0,8,143},{0,8,79},
+        {0,9,255}
+    };
+
+    static const code distfix[32] = {
+        {16,5,1},{23,5,257},{19,5,17},{27,5,4097},{17,5,5},{25,5,1025},
+        {21,5,65},{29,5,16385},{16,5,3},{24,5,513},{20,5,33},{28,5,8193},
+        {18,5,9},{26,5,2049},{22,5,129},{64,5,0},{16,5,2},{23,5,385},
+        {19,5,25},{27,5,6145},{17,5,7},{25,5,1537},{21,5,97},{29,5,24577},
+        {16,5,4},{24,5,769},{20,5,49},{28,5,12289},{18,5,13},{26,5,3073},
+        {22,5,193},{64,5,0}
+    };

vendor/libgit2-sys/libgit2/deps/zlib/inflate.c

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/inflate.c b/vendor/libgit2-sys/libgit2/deps/zlib/inflate.c
new file mode 100644
index 0000000..ac333e8
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/inflate.c
@@ -0,0 +1,1561 @@
+/* inflate.c -- zlib decompression
+ * Copyright (C) 1995-2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/*
+ * Change history:
+ *
+ * 1.2.beta0    24 Nov 2002
+ * - First version -- complete rewrite of inflate to simplify code, avoid
+ *   creation of window when not needed, minimize use of window when it is
+ *   needed, make inffast.c even faster, implement gzip decoding, and to
+ *   improve code readability and style over the previous zlib inflate code
+ *
+ * 1.2.beta1    25 Nov 2002
+ * - Use pointers for available input and output checking in inffast.c
+ * - Remove input and output counters in inffast.c
+ * - Change inffast.c entry and loop from avail_in >= 7 to >= 6
+ * - Remove unnecessary second byte pull from length extra in inffast.c
+ * - Unroll direct copy to three copies per loop in inffast.c
+ *
+ * 1.2.beta2    4 Dec 2002
+ * - Change external routine names to reduce potential conflicts
+ * - Correct filename to inffixed.h for fixed tables in inflate.c
+ * - Make hbuf[] unsigned char to match parameter type in inflate.c
+ * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset)
+ *   to avoid negation problem on Alphas (64 bit) in inflate.c
+ *
+ * 1.2.beta3    22 Dec 2002
+ * - Add comments on state->bits assertion in inffast.c
+ * - Add comments on op field in inftrees.h
+ * - Fix bug in reuse of allocated window after inflateReset()
+ * - Remove bit fields--back to byte structure for speed
+ * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
+ * - Change post-increments to pre-increments in inflate_fast(), PPC biased?
+ * - Add compile time option, POSTINC, to use post-increments instead (Intel?)
+ * - Make MATCH copy in inflate() much faster for when inflate_fast() not used
+ * - Use local copies of stream next and avail values, as well as local bit
+ *   buffer and bit count in inflate()--for speed when inflate_fast() not used
+ *
+ * 1.2.beta4    1 Jan 2003
+ * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
+ * - Move a comment on output buffer sizes from inffast.c to inflate.c
+ * - Add comments in inffast.c to introduce the inflate_fast() routine
+ * - Rearrange window copies in inflate_fast() for speed and simplification
+ * - Unroll last copy for window match in inflate_fast()
+ * - Use local copies of window variables in inflate_fast() for speed
+ * - Pull out common wnext == 0 case for speed in inflate_fast()
+ * - Make op and len in inflate_fast() unsigned for consistency
+ * - Add FAR to lcode and dcode declarations in inflate_fast()
+ * - Simplified bad distance check in inflate_fast()
+ * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
+ *   source file infback.c to provide a call-back interface to inflate for
+ *   programs like gzip and unzip -- uses window as output buffer to avoid
+ *   window copying
+ *
+ * 1.2.beta5    1 Jan 2003
+ * - Improved inflateBack() interface to allow the caller to provide initial
+ *   input in strm.
+ * - Fixed stored blocks bug in inflateBack()
+ *
+ * 1.2.beta6    4 Jan 2003
+ * - Added comments in inffast.c on effectiveness of POSTINC
+ * - Typecasting all around to reduce compiler warnings
+ * - Changed loops from while (1) or do {} while (1) to for (;;), again to
+ *   make compilers happy
+ * - Changed type of window in inflateBackInit() to unsigned char *
+ *
+ * 1.2.beta7    27 Jan 2003
+ * - Changed many types to unsigned or unsigned short to avoid warnings
+ * - Added inflateCopy() function
+ *
+ * 1.2.0        9 Mar 2003
+ * - Changed inflateBack() interface to provide separate opaque descriptors
+ *   for the in() and out() functions
+ * - Changed inflateBack() argument and in_func typedef to swap the length
+ *   and buffer address return values for the input function
+ * - Check next_in and next_out for Z_NULL on entry to inflate()
+ *
+ * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
+ */
+
+#include "zutil.h"
+#include "inftrees.h"
+#include "inflate.h"
+#include "inffast.h"
+
+#ifdef MAKEFIXED
+#  ifndef BUILDFIXED
+#    define BUILDFIXED
+#  endif
+#endif
+
+/* function prototypes */
+local int inflateStateCheck OF((z_streamp strm));
+local void fixedtables OF((struct inflate_state FAR *state));
+local int updatewindow OF((z_streamp strm, const unsigned char FAR *end,
+                           unsigned copy));
+#ifdef BUILDFIXED
+   void makefixed OF((void));
+#endif
+local unsigned syncsearch OF((unsigned FAR *have, const unsigned char FAR *buf,
+                              unsigned len));
+
+local int inflateStateCheck(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+    if (strm == Z_NULL ||
+        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
+        return 1;
+    state = (struct inflate_state FAR *)strm->state;
+    if (state == Z_NULL || state->strm != strm ||
+        state->mode < HEAD || state->mode > SYNC)
+        return 1;
+    return 0;
+}
+
+int ZEXPORT inflateResetKeep(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    strm->total_in = strm->total_out = state->total = 0;
+    strm->msg = Z_NULL;
+    if (state->wrap)        /* to support ill-conceived Java test suite */
+        strm->adler = state->wrap & 1;
+    state->mode = HEAD;
+    state->last = 0;
+    state->havedict = 0;
+    state->dmax = 32768U;
+    state->head = Z_NULL;
+    state->hold = 0;
+    state->bits = 0;
+    state->lencode = state->distcode = state->next = state->codes;
+    state->sane = 1;
+    state->back = -1;
+    Tracev((stderr, "inflate: reset\n"));
+    return Z_OK;
+}
+
+int ZEXPORT inflateReset(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    state->wsize = 0;
+    state->whave = 0;
+    state->wnext = 0;
+    return inflateResetKeep(strm);
+}
+
+int ZEXPORT inflateReset2(strm, windowBits)
+z_streamp strm;
+int windowBits;
+{
+    int wrap;
+    struct inflate_state FAR *state;
+
+    /* get the state */
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+
+    /* extract wrap request from windowBits parameter */
+    if (windowBits < 0) {
+        wrap = 0;
+        windowBits = -windowBits;
+    }
+    else {
+        wrap = (windowBits >> 4) + 5;
+#ifdef GUNZIP
+        if (windowBits < 48)
+            windowBits &= 15;
+#endif
+    }
+
+    /* set number of window bits, free window if different */
+    if (windowBits && (windowBits < 8 || windowBits > 15))
+        return Z_STREAM_ERROR;
+    if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) {
+        ZFREE(strm, state->window);
+        state->window = Z_NULL;
+    }
+
+    /* update state and reset the rest of it */
+    state->wrap = wrap;
+    state->wbits = (unsigned)windowBits;
+    return inflateReset(strm);
+}
+
+int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
+z_streamp strm;
+int windowBits;
+const char *version;
+int stream_size;
+{
+    int ret;
+    struct inflate_state FAR *state;
+
+    if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
+        stream_size != (int)(sizeof(z_stream)))
+        return Z_VERSION_ERROR;
+    if (strm == Z_NULL) return Z_STREAM_ERROR;
+    strm->msg = Z_NULL;                 /* in case we return an error */
+    if (strm->zalloc == (alloc_func)0) {
+#ifdef Z_SOLO
+        return Z_STREAM_ERROR;
+#else
+        strm->zalloc = zcalloc;
+        strm->opaque = (voidpf)0;
+#endif
+    }
+    if (strm->zfree == (free_func)0)
+#ifdef Z_SOLO
+        return Z_STREAM_ERROR;
+#else
+        strm->zfree = zcfree;
+#endif
+    state = (struct inflate_state FAR *)
+            ZALLOC(strm, 1, sizeof(struct inflate_state));
+    if (state == Z_NULL) return Z_MEM_ERROR;
+    Tracev((stderr, "inflate: allocated\n"));
+    strm->state = (struct internal_state FAR *)state;
+    state->strm = strm;
+    state->window = Z_NULL;
+    state->mode = HEAD;     /* to pass state test in inflateReset2() */
+    ret = inflateReset2(strm, windowBits);
+    if (ret != Z_OK) {
+        ZFREE(strm, state);
+        strm->state = Z_NULL;
+    }
+    return ret;
+}
+
+int ZEXPORT inflateInit_(strm, version, stream_size)
+z_streamp strm;
+const char *version;
+int stream_size;
+{
+    return inflateInit2_(strm, DEF_WBITS, version, stream_size);
+}
+
+int ZEXPORT inflatePrime(strm, bits, value)
+z_streamp strm;
+int bits;
+int value;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if (bits < 0) {
+        state->hold = 0;
+        state->bits = 0;
+        return Z_OK;
+    }
+    if (bits > 16 || state->bits + (uInt)bits > 32) return Z_STREAM_ERROR;
+    value &= (1L << bits) - 1;
+    state->hold += (unsigned)value << state->bits;
+    state->bits += (uInt)bits;
+    return Z_OK;
+}
+
+/*
+   Return state with length and distance decoding tables and index sizes set to
+   fixed code decoding.  Normally this returns fixed tables from inffixed.h.
+   If BUILDFIXED is defined, then instead this routine builds the tables the
+   first time it's called, and returns those tables the first time and
+   thereafter.  This reduces the size of the code by about 2K bytes, in
+   exchange for a little execution time.  However, BUILDFIXED should not be
+   used for threaded applications, since the rewriting of the tables and virgin
+   may not be thread-safe.
+ */
+local void fixedtables(state)
+struct inflate_state FAR *state;
+{
+#ifdef BUILDFIXED
+    static int virgin = 1;
+    static code *lenfix, *distfix;
+    static code fixed[544];
+
+    /* build fixed huffman tables if first call (may not be thread safe) */
+    if (virgin) {
+        unsigned sym, bits;
+        static code *next;
+
+        /* literal/length table */
+        sym = 0;
+        while (sym < 144) state->lens[sym++] = 8;
+        while (sym < 256) state->lens[sym++] = 9;
+        while (sym < 280) state->lens[sym++] = 7;
+        while (sym < 288) state->lens[sym++] = 8;
+        next = fixed;
+        lenfix = next;
+        bits = 9;
+        inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
+
+        /* distance table */
+        sym = 0;
+        while (sym < 32) state->lens[sym++] = 5;
+        distfix = next;
+        bits = 5;
+        inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
+
+        /* do this just once */
+        virgin = 0;
+    }
+#else /* !BUILDFIXED */
+#   include "inffixed.h"
+#endif /* BUILDFIXED */
+    state->lencode = lenfix;
+    state->lenbits = 9;
+    state->distcode = distfix;
+    state->distbits = 5;
+}
+
+#ifdef MAKEFIXED
+#include <stdio.h>
+
+/*
+   Write out the inffixed.h that is #include'd above.  Defining MAKEFIXED also
+   defines BUILDFIXED, so the tables are built on the fly.  makefixed() writes
+   those tables to stdout, which would be piped to inffixed.h.  A small program
+   can simply call makefixed to do this:
+
+    void makefixed(void);
+
+    int main(void)
+    {
+        makefixed();
+        return 0;
+    }
+
+   Then that can be linked with zlib built with MAKEFIXED defined and run:
+
+    a.out > inffixed.h
+ */
+void makefixed()
+{
+    unsigned low, size;
+    struct inflate_state state;
+
+    fixedtables(&state);
+    puts("    /* inffixed.h -- table for decoding fixed codes");
+    puts("     * Generated automatically by makefixed().");
+    puts("     */");
+    puts("");
+    puts("    /* WARNING: this file should *not* be used by applications.");
+    puts("       It is part of the implementation of this library and is");
+    puts("       subject to change. Applications should only use zlib.h.");
+    puts("     */");
+    puts("");
+    size = 1U << 9;
+    printf("    static const code lenfix[%u] = {", size);
+    low = 0;
+    for (;;) {
+        if ((low % 7) == 0) printf("\n        ");
+        printf("{%u,%u,%d}", (low & 127) == 99 ? 64 : state.lencode[low].op,
+               state.lencode[low].bits, state.lencode[low].val);
+        if (++low == size) break;
+        putchar(',');
+    }
+    puts("\n    };");
+    size = 1U << 5;
+    printf("\n    static const code distfix[%u] = {", size);
+    low = 0;
+    for (;;) {
+        if ((low % 6) == 0) printf("\n        ");
+        printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
+               state.distcode[low].val);
+        if (++low == size) break;
+        putchar(',');
+    }
+    puts("\n    };");
+}
+#endif /* MAKEFIXED */
+
+/*
+   Update the window with the last wsize (normally 32K) bytes written before
+   returning.  If window does not exist yet, create it.  This is only called
+   when a window is already in use, or when output has been written during this
+   inflate call, but the end of the deflate stream has not been reached yet.
+   It is also called to create a window for dictionary data when a dictionary
+   is loaded.
+
+   Providing output buffers larger than 32K to inflate() should provide a speed
+   advantage, since only the last 32K of output is copied to the sliding window
+   upon return from inflate(), and since all distances after the first 32K of
+   output will fall in the output data, making match copies simpler and faster.
+   The advantage may be dependent on the size of the processor's data caches.
+ */
+local int updatewindow(strm, end, copy)
+z_streamp strm;
+const Bytef *end;
+unsigned copy;
+{
+    struct inflate_state FAR *state;
+    unsigned dist;
+
+    state = (struct inflate_state FAR *)strm->state;
+
+    /* if it hasn't been done already, allocate space for the window */
+    if (state->window == Z_NULL) {
+        state->window = (unsigned char FAR *)
+                        ZALLOC(strm, 1U << state->wbits,
+                               sizeof(unsigned char));
+        if (state->window == Z_NULL) return 1;
+    }
+
+    /* if window not in use yet, initialize */
+    if (state->wsize == 0) {
+        state->wsize = 1U << state->wbits;
+        state->wnext = 0;
+        state->whave = 0;
+    }
+
+    /* copy state->wsize or less output bytes into the circular window */
+    if (copy >= state->wsize) {
+        zmemcpy(state->window, end - state->wsize, state->wsize);
+        state->wnext = 0;
+        state->whave = state->wsize;
+    }
+    else {
+        dist = state->wsize - state->wnext;
+        if (dist > copy) dist = copy;
+        zmemcpy(state->window + state->wnext, end - copy, dist);
+        copy -= dist;
+        if (copy) {
+            zmemcpy(state->window, end - copy, copy);
+            state->wnext = copy;
+            state->whave = state->wsize;
+        }
+        else {
+            state->wnext += dist;
+            if (state->wnext == state->wsize) state->wnext = 0;
+            if (state->whave < state->wsize) state->whave += dist;
+        }
+    }
+    return 0;
+}
+
+/* Macros for inflate(): */
+
+/* check function to use adler32() for zlib or crc32() for gzip */
+#ifdef GUNZIP
+#  define UPDATE(check, buf, len) \
+    (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
+#else
+#  define UPDATE(check, buf, len) adler32(check, buf, len)
+#endif
+
+/* check macros for header crc */
+#ifdef GUNZIP
+#  define CRC2(check, word) \
+    do { \
+        hbuf[0] = (unsigned char)(word); \
+        hbuf[1] = (unsigned char)((word) >> 8); \
+        check = crc32(check, hbuf, 2); \
+    } while (0)
+
+#  define CRC4(check, word) \
+    do { \
+        hbuf[0] = (unsigned char)(word); \
+        hbuf[1] = (unsigned char)((word) >> 8); \
+        hbuf[2] = (unsigned char)((word) >> 16); \
+        hbuf[3] = (unsigned char)((word) >> 24); \
+        check = crc32(check, hbuf, 4); \
+    } while (0)
+#endif
+
+/* Load registers with state in inflate() for speed */
+#define LOAD() \
+    do { \
+        put = strm->next_out; \
+        left = strm->avail_out; \
+        next = strm->next_in; \
+        have = strm->avail_in; \
+        hold = state->hold; \
+        bits = state->bits; \
+    } while (0)
+
+/* Restore state from registers in inflate() */
+#define RESTORE() \
+    do { \
+        strm->next_out = put; \
+        strm->avail_out = left; \
+        strm->next_in = next; \
+        strm->avail_in = have; \
+        state->hold = hold; \
+        state->bits = bits; \
+    } while (0)
+
+/* Clear the input bit accumulator */
+#define INITBITS() \
+    do { \
+        hold = 0; \
+        bits = 0; \
+    } while (0)
+
+/* Get a byte of input into the bit accumulator, or return from inflate()
+   if there is no input available. */
+#define PULLBYTE() \
+    do { \
+        if (have == 0) goto inf_leave; \
+        have--; \
+        hold += (unsigned long)(*next++) << bits; \
+        bits += 8; \
+    } while (0)
+
+/* Assure that there are at least n bits in the bit accumulator.  If there is
+   not enough available input to do that, then return from inflate(). */
+#define NEEDBITS(n) \
+    do { \
+        while (bits < (unsigned)(n)) \
+            PULLBYTE(); \
+    } while (0)
+
+/* Return the low n bits of the bit accumulator (n < 16) */
+#define BITS(n) \
+    ((unsigned)hold & ((1U << (n)) - 1))
+
+/* Remove n bits from the bit accumulator */
+#define DROPBITS(n) \
+    do { \
+        hold >>= (n); \
+        bits -= (unsigned)(n); \
+    } while (0)
+
+/* Remove zero to seven bits as needed to go to a byte boundary */
+#define BYTEBITS() \
+    do { \
+        hold >>= bits & 7; \
+        bits -= bits & 7; \
+    } while (0)
+
+/*
+   inflate() uses a state machine to process as much input data and generate as
+   much output data as possible before returning.  The state machine is
+   structured roughly as follows:
+
+    for (;;) switch (state) {
+    ...
+    case STATEn:
+        if (not enough input data or output space to make progress)
+            return;
+        ... make progress ...
+        state = STATEm;
+        break;
+    ...
+    }
+
+   so when inflate() is called again, the same case is attempted again, and
+   if the appropriate resources are provided, the machine proceeds to the
+   next state.  The NEEDBITS() macro is usually the way the state evaluates
+   whether it can proceed or should return.  NEEDBITS() does the return if
+   the requested bits are not available.  The typical use of the BITS macros
+   is:
+
+        NEEDBITS(n);
+        ... do something with BITS(n) ...
+        DROPBITS(n);
+
+   where NEEDBITS(n) either returns from inflate() if there isn't enough
+   input left to load n bits into the accumulator, or it continues.  BITS(n)
+   gives the low n bits in the accumulator.  When done, DROPBITS(n) drops
+   the low n bits off the accumulator.  INITBITS() clears the accumulator
+   and sets the number of available bits to zero.  BYTEBITS() discards just
+   enough bits to put the accumulator on a byte boundary.  After BYTEBITS()
+   and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
+
+   NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
+   if there is no input available.  The decoding of variable length codes uses
+   PULLBYTE() directly in order to pull just enough bytes to decode the next
+   code, and no more.
+
+   Some states loop until they get enough input, making sure that enough
+   state information is maintained to continue the loop where it left off
+   if NEEDBITS() returns in the loop.  For example, want, need, and keep
+   would all have to actually be part of the saved state in case NEEDBITS()
+   returns:
+
+    case STATEw:
+        while (want < need) {
+            NEEDBITS(n);
+            keep[want++] = BITS(n);
+            DROPBITS(n);
+        }
+        state = STATEx;
+    case STATEx:
+
+   As shown above, if the next state is also the next case, then the break
+   is omitted.
+
+   A state may also return if there is not enough output space available to
+   complete that state.  Those states are copying stored data, writing a
+   literal byte, and copying a matching string.
+
+   When returning, a "goto inf_leave" is used to update the total counters,
+   update the check value, and determine whether any progress has been made
+   during that inflate() call in order to return the proper return code.
+   Progress is defined as a change in either strm->avail_in or strm->avail_out.
+   When there is a window, goto inf_leave will update the window with the last
+   output written.  If a goto inf_leave occurs in the middle of decompression
+   and there is no window currently, goto inf_leave will create one and copy
+   output to the window for the next call of inflate().
+
+   In this implementation, the flush parameter of inflate() only affects the
+   return code (per zlib.h).  inflate() always writes as much as possible to
+   strm->next_out, given the space available and the provided input--the effect
+   documented in zlib.h of Z_SYNC_FLUSH.  Furthermore, inflate() always defers
+   the allocation of and copying into a sliding window until necessary, which
+   provides the effect documented in zlib.h for Z_FINISH when the entire input
+   stream available.  So the only thing the flush parameter actually does is:
+   when flush is set to Z_FINISH, inflate() cannot return Z_OK.  Instead it
+   will return Z_BUF_ERROR if it has not reached the end of the stream.
+ */
+
+int ZEXPORT inflate(strm, flush)
+z_streamp strm;
+int flush;
+{
+    struct inflate_state FAR *state;
+    z_const unsigned char FAR *next;    /* next input */
+    unsigned char FAR *put;     /* next output */
+    unsigned have, left;        /* available input and output */
+    unsigned long hold;         /* bit buffer */
+    unsigned bits;              /* bits in bit buffer */
+    unsigned in, out;           /* save starting available input and output */
+    unsigned copy;              /* number of stored or match bytes to copy */
+    unsigned char FAR *from;    /* where to copy match bytes from */
+    code here;                  /* current decoding table entry */
+    code last;                  /* parent table entry */
+    unsigned len;               /* length to copy for repeats, bits to drop */
+    int ret;                    /* return code */
+#ifdef GUNZIP
+    unsigned char hbuf[4];      /* buffer for gzip header crc calculation */
+#endif
+    static const unsigned short order[19] = /* permutation of code lengths */
+        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+    if (inflateStateCheck(strm) || strm->next_out == Z_NULL ||
+        (strm->next_in == Z_NULL && strm->avail_in != 0))
+        return Z_STREAM_ERROR;
+
+    state = (struct inflate_state FAR *)strm->state;
+    if (state->mode == TYPE) state->mode = TYPEDO;      /* skip check */
+    LOAD();
+    in = have;
+    out = left;
+    ret = Z_OK;
+    for (;;)
+        switch (state->mode) {
+        case HEAD:
+            if (state->wrap == 0) {
+                state->mode = TYPEDO;
+                break;
+            }
+            NEEDBITS(16);
+#ifdef GUNZIP
+            if ((state->wrap & 2) && hold == 0x8b1f) {  /* gzip header */
+                if (state->wbits == 0)
+                    state->wbits = 15;
+                state->check = crc32(0L, Z_NULL, 0);
+                CRC2(state->check, hold);
+                INITBITS();
+                state->mode = FLAGS;
+                break;
+            }
+            state->flags = 0;           /* expect zlib header */
+            if (state->head != Z_NULL)
+                state->head->done = -1;
+            if (!(state->wrap & 1) ||   /* check if zlib header allowed */
+#else
+            if (
+#endif
+                ((BITS(8) << 8) + (hold >> 8)) % 31) {
+                strm->msg = (char *)"incorrect header check";
+                state->mode = BAD;
+                break;
+            }
+            if (BITS(4) != Z_DEFLATED) {
+                strm->msg = (char *)"unknown compression method";
+                state->mode = BAD;
+                break;
+            }
+            DROPBITS(4);
+            len = BITS(4) + 8;
+            if (state->wbits == 0)
+                state->wbits = len;
+            if (len > 15 || len > state->wbits) {
+                strm->msg = (char *)"invalid window size";
+                state->mode = BAD;
+                break;
+            }
+            state->dmax = 1U << len;
+            Tracev((stderr, "inflate:   zlib header ok\n"));
+            strm->adler = state->check = adler32(0L, Z_NULL, 0);
+            state->mode = hold & 0x200 ? DICTID : TYPE;
+            INITBITS();
+            break;
+#ifdef GUNZIP
+        case FLAGS:
+            NEEDBITS(16);
+            state->flags = (int)(hold);
+            if ((state->flags & 0xff) != Z_DEFLATED) {
+                strm->msg = (char *)"unknown compression method";
+                state->mode = BAD;
+                break;
+            }
+            if (state->flags & 0xe000) {
+                strm->msg = (char *)"unknown header flags set";
+                state->mode = BAD;
+                break;
+            }
+            if (state->head != Z_NULL)
+                state->head->text = (int)((hold >> 8) & 1);
+            if ((state->flags & 0x0200) && (state->wrap & 4))
+                CRC2(state->check, hold);
+            INITBITS();
+            state->mode = TIME;
+        case TIME:
+            NEEDBITS(32);
+            if (state->head != Z_NULL)
+                state->head->time = hold;
+            if ((state->flags & 0x0200) && (state->wrap & 4))
+                CRC4(state->check, hold);
+            INITBITS();
+            state->mode = OS;
+        case OS:
+            NEEDBITS(16);
+            if (state->head != Z_NULL) {
+                state->head->xflags = (int)(hold & 0xff);
+                state->head->os = (int)(hold >> 8);
+            }
+            if ((state->flags & 0x0200) && (state->wrap & 4))
+                CRC2(state->check, hold);
+            INITBITS();
+            state->mode = EXLEN;
+        case EXLEN:
+            if (state->flags & 0x0400) {
+                NEEDBITS(16);
+                state->length = (unsigned)(hold);
+                if (state->head != Z_NULL)
+                    state->head->extra_len = (unsigned)hold;
+                if ((state->flags & 0x0200) && (state->wrap & 4))
+                    CRC2(state->check, hold);
+                INITBITS();
+            }
+            else if (state->head != Z_NULL)
+                state->head->extra = Z_NULL;
+            state->mode = EXTRA;
+        case EXTRA:
+            if (state->flags & 0x0400) {
+                copy = state->length;
+                if (copy > have) copy = have;
+                if (copy) {
+                    if (state->head != Z_NULL &&
+                        state->head->extra != Z_NULL) {
+                        len = state->head->extra_len - state->length;
+                        zmemcpy(state->head->extra + len, next,
+                                len + copy > state->head->extra_max ?
+                                state->head->extra_max - len : copy);
+                    }
+                    if ((state->flags & 0x0200) && (state->wrap & 4))
+                        state->check = crc32(state->check, next, copy);
+                    have -= copy;
+                    next += copy;
+                    state->length -= copy;
+                }
+                if (state->length) goto inf_leave;
+            }
+            state->length = 0;
+            state->mode = NAME;
+        case NAME:
+            if (state->flags & 0x0800) {
+                if (have == 0) goto inf_leave;
+                copy = 0;
+                do {
+                    len = (unsigned)(next[copy++]);
+                    if (state->head != Z_NULL &&
+                            state->head->name != Z_NULL &&
+                            state->length < state->head->name_max)
+                        state->head->name[state->length++] = (Bytef)len;
+                } while (len && copy < have);
+                if ((state->flags & 0x0200) && (state->wrap & 4))
+                    state->check = crc32(state->check, next, copy);
+                have -= copy;
+                next += copy;
+                if (len) goto inf_leave;
+            }
+            else if (state->head != Z_NULL)
+                state->head->name = Z_NULL;
+            state->length = 0;
+            state->mode = COMMENT;
+        case COMMENT:
+            if (state->flags & 0x1000) {
+                if (have == 0) goto inf_leave;
+                copy = 0;
+                do {
+                    len = (unsigned)(next[copy++]);
+                    if (state->head != Z_NULL &&
+                            state->head->comment != Z_NULL &&
+                            state->length < state->head->comm_max)
+                        state->head->comment[state->length++] = (Bytef)len;
+                } while (len && copy < have);
+                if ((state->flags & 0x0200) && (state->wrap & 4))
+                    state->check = crc32(state->check, next, copy);
+                have -= copy;
+                next += copy;
+                if (len) goto inf_leave;
+            }
+            else if (state->head != Z_NULL)
+                state->head->comment = Z_NULL;
+            state->mode = HCRC;
+        case HCRC:
+            if (state->flags & 0x0200) {
+                NEEDBITS(16);
+                if ((state->wrap & 4) && hold != (state->check & 0xffff)) {
+                    strm->msg = (char *)"header crc mismatch";
+                    state->mode = BAD;
+                    break;
+                }
+                INITBITS();
+            }
+            if (state->head != Z_NULL) {
+                state->head->hcrc = (int)((state->flags >> 9) & 1);
+                state->head->done = 1;
+            }
+            strm->adler = state->check = crc32(0L, Z_NULL, 0);
+            state->mode = TYPE;
+            break;
+#endif
+        case DICTID:
+            NEEDBITS(32);
+            strm->adler = state->check = ZSWAP32(hold);
+            INITBITS();
+            state->mode = DICT;
+        case DICT:
+            if (state->havedict == 0) {
+                RESTORE();
+                return Z_NEED_DICT;
+            }
+            strm->adler = state->check = adler32(0L, Z_NULL, 0);
+            state->mode = TYPE;
+        case TYPE:
+            if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
+        case TYPEDO:
+            if (state->last) {
+                BYTEBITS();
+                state->mode = CHECK;
+                break;
+            }
+            NEEDBITS(3);
+            state->last = BITS(1);
+            DROPBITS(1);
+            switch (BITS(2)) {
+            case 0:                             /* stored block */
+                Tracev((stderr, "inflate:     stored block%s\n",
+                        state->last ? " (last)" : ""));
+                state->mode = STORED;
+                break;
+            case 1:                             /* fixed block */
+                fixedtables(state);
+                Tracev((stderr, "inflate:     fixed codes block%s\n",
+                        state->last ? " (last)" : ""));
+                state->mode = LEN_;             /* decode codes */
+                if (flush == Z_TREES) {
+                    DROPBITS(2);
+                    goto inf_leave;
+                }
+                break;
+            case 2:                             /* dynamic block */
+                Tracev((stderr, "inflate:     dynamic codes block%s\n",
+                        state->last ? " (last)" : ""));
+                state->mode = TABLE;
+                break;
+            case 3:
+                strm->msg = (char *)"invalid block type";
+                state->mode = BAD;
+            }
+            DROPBITS(2);
+            break;
+        case STORED:
+            BYTEBITS();                         /* go to byte boundary */
+            NEEDBITS(32);
+            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
+                strm->msg = (char *)"invalid stored block lengths";
+                state->mode = BAD;
+                break;
+            }
+            state->length = (unsigned)hold & 0xffff;
+            Tracev((stderr, "inflate:       stored length %u\n",
+                    state->length));
+            INITBITS();
+            state->mode = COPY_;
+            if (flush == Z_TREES) goto inf_leave;
+        case COPY_:
+            state->mode = COPY;
+        case COPY:
+            copy = state->length;
+            if (copy) {
+                if (copy > have) copy = have;
+                if (copy > left) copy = left;
+                if (copy == 0) goto inf_leave;
+                zmemcpy(put, next, copy);
+                have -= copy;
+                next += copy;
+                left -= copy;
+                put += copy;
+                state->length -= copy;
+                break;
+            }
+            Tracev((stderr, "inflate:       stored end\n"));
+            state->mode = TYPE;
+            break;
+        case TABLE:
+            NEEDBITS(14);
+            state->nlen = BITS(5) + 257;
+            DROPBITS(5);
+            state->ndist = BITS(5) + 1;
+            DROPBITS(5);
+            state->ncode = BITS(4) + 4;
+            DROPBITS(4);
+#ifndef PKZIP_BUG_WORKAROUND
+            if (state->nlen > 286 || state->ndist > 30) {
+                strm->msg = (char *)"too many length or distance symbols";
+                state->mode = BAD;
+                break;
+            }
+#endif
+            Tracev((stderr, "inflate:       table sizes ok\n"));
+            state->have = 0;
+            state->mode = LENLENS;
+        case LENLENS:
+            while (state->have < state->ncode) {
+                NEEDBITS(3);
+                state->lens[order[state->have++]] = (unsigned short)BITS(3);
+                DROPBITS(3);
+            }
+            while (state->have < 19)
+                state->lens[order[state->have++]] = 0;
+            state->next = state->codes;
+            state->lencode = (const code FAR *)(state->next);
+            state->lenbits = 7;
+            ret = inflate_table(CODES, state->lens, 19, &(state->next),
+                                &(state->lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid code lengths set";
+                state->mode = BAD;
+                break;
+            }
+            Tracev((stderr, "inflate:       code lengths ok\n"));
+            state->have = 0;
+            state->mode = CODELENS;
+        case CODELENS:
+            while (state->have < state->nlen + state->ndist) {
+                for (;;) {
+                    here = state->lencode[BITS(state->lenbits)];
+                    if ((unsigned)(here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                if (here.val < 16) {
+                    DROPBITS(here.bits);
+                    state->lens[state->have++] = here.val;
+                }
+                else {
+                    if (here.val == 16) {
+                        NEEDBITS(here.bits + 2);
+                        DROPBITS(here.bits);
+                        if (state->have == 0) {
+                            strm->msg = (char *)"invalid bit length repeat";
+                            state->mode = BAD;
+                            break;
+                        }
+                        len = state->lens[state->have - 1];
+                        copy = 3 + BITS(2);
+                        DROPBITS(2);
+                    }
+                    else if (here.val == 17) {
+                        NEEDBITS(here.bits + 3);
+                        DROPBITS(here.bits);
+                        len = 0;
+                        copy = 3 + BITS(3);
+                        DROPBITS(3);
+                    }
+                    else {
+                        NEEDBITS(here.bits + 7);
+                        DROPBITS(here.bits);
+                        len = 0;
+                        copy = 11 + BITS(7);
+                        DROPBITS(7);
+                    }
+                    if (state->have + copy > state->nlen + state->ndist) {
+                        strm->msg = (char *)"invalid bit length repeat";
+                        state->mode = BAD;
+                        break;
+                    }
+                    while (copy--)
+                        state->lens[state->have++] = (unsigned short)len;
+                }
+            }
+
+            /* handle error breaks in while */
+            if (state->mode == BAD) break;
+
+            /* check for end-of-block code (better have one) */
+            if (state->lens[256] == 0) {
+                strm->msg = (char *)"invalid code -- missing end-of-block";
+                state->mode = BAD;
+                break;
+            }
+
+            /* build code tables -- note: do not change the lenbits or distbits
+               values here (9 and 6) without reading the comments in inftrees.h
+               concerning the ENOUGH constants, which depend on those values */
+            state->next = state->codes;
+            state->lencode = (const code FAR *)(state->next);
+            state->lenbits = 9;
+            ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
+                                &(state->lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid literal/lengths set";
+                state->mode = BAD;
+                break;
+            }
+            state->distcode = (const code FAR *)(state->next);
+            state->distbits = 6;
+            ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
+                            &(state->next), &(state->distbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid distances set";
+                state->mode = BAD;
+                break;
+            }
+            Tracev((stderr, "inflate:       codes ok\n"));
+            state->mode = LEN_;
+            if (flush == Z_TREES) goto inf_leave;
+        case LEN_:
+            state->mode = LEN;
+        case LEN:
+            if (have >= 6 && left >= 258) {
+                RESTORE();
+                inflate_fast(strm, out);
+                LOAD();
+                if (state->mode == TYPE)
+                    state->back = -1;
+                break;
+            }
+            state->back = 0;
+            for (;;) {
+                here = state->lencode[BITS(state->lenbits)];
+                if ((unsigned)(here.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if (here.op && (here.op & 0xf0) == 0) {
+                last = here;
+                for (;;) {
+                    here = state->lencode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+                state->back += last.bits;
+            }
+            DROPBITS(here.bits);
+            state->back += here.bits;
+            state->length = (unsigned)here.val;
+            if ((int)(here.op) == 0) {
+                Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
+                        "inflate:         literal '%c'\n" :
+                        "inflate:         literal 0x%02x\n", here.val));
+                state->mode = LIT;
+                break;
+            }
+            if (here.op & 32) {
+                Tracevv((stderr, "inflate:         end of block\n"));
+                state->back = -1;
+                state->mode = TYPE;
+                break;
+            }
+            if (here.op & 64) {
+                strm->msg = (char *)"invalid literal/length code";
+                state->mode = BAD;
+                break;
+            }
+            state->extra = (unsigned)(here.op) & 15;
+            state->mode = LENEXT;
+        case LENEXT:
+            if (state->extra) {
+                NEEDBITS(state->extra);
+                state->length += BITS(state->extra);
+                DROPBITS(state->extra);
+                state->back += state->extra;
+            }
+            Tracevv((stderr, "inflate:         length %u\n", state->length));
+            state->was = state->length;
+            state->mode = DIST;
+        case DIST:
+            for (;;) {
+                here = state->distcode[BITS(state->distbits)];
+                if ((unsigned)(here.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if ((here.op & 0xf0) == 0) {
+                last = here;
+                for (;;) {
+                    here = state->distcode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+                state->back += last.bits;
+            }
+            DROPBITS(here.bits);
+            state->back += here.bits;
+            if (here.op & 64) {
+                strm->msg = (char *)"invalid distance code";
+                state->mode = BAD;
+                break;
+            }
+            state->offset = (unsigned)here.val;
+            state->extra = (unsigned)(here.op) & 15;
+            state->mode = DISTEXT;
+        case DISTEXT:
+            if (state->extra) {
+                NEEDBITS(state->extra);
+                state->offset += BITS(state->extra);
+                DROPBITS(state->extra);
+                state->back += state->extra;
+            }
+#ifdef INFLATE_STRICT
+            if (state->offset > state->dmax) {
+                strm->msg = (char *)"invalid distance too far back";
+                state->mode = BAD;
+                break;
+            }
+#endif
+            Tracevv((stderr, "inflate:         distance %u\n", state->offset));
+            state->mode = MATCH;
+        case MATCH:
+            if (left == 0) goto inf_leave;
+            copy = out - left;
+            if (state->offset > copy) {         /* copy from window */
+                copy = state->offset - copy;
+                if (copy > state->whave) {
+                    if (state->sane) {
+                        strm->msg = (char *)"invalid distance too far back";
+                        state->mode = BAD;
+                        break;
+                    }
+#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
+                    Trace((stderr, "inflate.c too far\n"));
+                    copy -= state->whave;
+                    if (copy > state->length) copy = state->length;
+                    if (copy > left) copy = left;
+                    left -= copy;
+                    state->length -= copy;
+                    do {
+                        *put++ = 0;
+                    } while (--copy);
+                    if (state->length == 0) state->mode = LEN;
+                    break;
+#endif
+                }
+                if (copy > state->wnext) {
+                    copy -= state->wnext;
+                    from = state->window + (state->wsize - copy);
+                }
+                else
+                    from = state->window + (state->wnext - copy);
+                if (copy > state->length) copy = state->length;
+            }
+            else {                              /* copy from output */
+                from = put - state->offset;
+                copy = state->length;
+            }
+            if (copy > left) copy = left;
+            left -= copy;
+            state->length -= copy;
+            do {
+                *put++ = *from++;
+            } while (--copy);
+            if (state->length == 0) state->mode = LEN;
+            break;
+        case LIT:
+            if (left == 0) goto inf_leave;
+            *put++ = (unsigned char)(state->length);
+            left--;
+            state->mode = LEN;
+            break;
+        case CHECK:
+            if (state->wrap) {
+                NEEDBITS(32);
+                out -= left;
+                strm->total_out += out;
+                state->total += out;
+                if ((state->wrap & 4) && out)
+                    strm->adler = state->check =
+                        UPDATE(state->check, put - out, out);
+                out = left;
+                if ((state->wrap & 4) && (
+#ifdef GUNZIP
+                     state->flags ? hold :
+#endif
+                     ZSWAP32(hold)) != state->check) {
+                    strm->msg = (char *)"incorrect data check";
+                    state->mode = BAD;
+                    break;
+                }
+                INITBITS();
+                Tracev((stderr, "inflate:   check matches trailer\n"));
+            }
+#ifdef GUNZIP
+            state->mode = LENGTH;
+        case LENGTH:
+            if (state->wrap && state->flags) {
+                NEEDBITS(32);
+                if (hold != (state->total & 0xffffffffUL)) {
+                    strm->msg = (char *)"incorrect length check";
+                    state->mode = BAD;
+                    break;
+                }
+                INITBITS();
+                Tracev((stderr, "inflate:   length matches trailer\n"));
+            }
+#endif
+            state->mode = DONE;
+        case DONE:
+            ret = Z_STREAM_END;
+            goto inf_leave;
+        case BAD:
+            ret = Z_DATA_ERROR;
+            goto inf_leave;
+        case MEM:
+            return Z_MEM_ERROR;
+        case SYNC:
+        default:
+            return Z_STREAM_ERROR;
+        }
+
+    /*
+       Return from inflate(), updating the total counts and the check value.
+       If there was no progress during the inflate() call, return a buffer
+       error.  Call updatewindow() to create and/or update the window state.
+       Note: a memory error from inflate() is non-recoverable.
+     */
+  inf_leave:
+    RESTORE();
+    if (state->wsize || (out != strm->avail_out && state->mode < BAD &&
+            (state->mode < CHECK || flush != Z_FINISH)))
+        if (updatewindow(strm, strm->next_out, out - strm->avail_out)) {
+            state->mode = MEM;
+            return Z_MEM_ERROR;
+        }
+    in -= strm->avail_in;
+    out -= strm->avail_out;
+    strm->total_in += in;
+    strm->total_out += out;
+    state->total += out;
+    if ((state->wrap & 4) && out)
+        strm->adler = state->check =
+            UPDATE(state->check, strm->next_out - out, out);
+    strm->data_type = (int)state->bits + (state->last ? 64 : 0) +
+                      (state->mode == TYPE ? 128 : 0) +
+                      (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
+    if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
+        ret = Z_BUF_ERROR;
+    return ret;
+}
+
+int ZEXPORT inflateEnd(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+    if (inflateStateCheck(strm))
+        return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if (state->window != Z_NULL) ZFREE(strm, state->window);
+    ZFREE(strm, strm->state);
+    strm->state = Z_NULL;
+    Tracev((stderr, "inflate: end\n"));
+    return Z_OK;
+}
+
+int ZEXPORT inflateGetDictionary(strm, dictionary, dictLength)
+z_streamp strm;
+Bytef *dictionary;
+uInt *dictLength;
+{
+    struct inflate_state FAR *state;
+
+    /* check state */
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+
+    /* copy dictionary */
+    if (state->whave && dictionary != Z_NULL) {
+        zmemcpy(dictionary, state->window + state->wnext,
+                state->whave - state->wnext);
+        zmemcpy(dictionary + state->whave - state->wnext,
+                state->window, state->wnext);
+    }
+    if (dictLength != Z_NULL)
+        *dictLength = state->whave;
+    return Z_OK;
+}
+
+int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength)
+z_streamp strm;
+const Bytef *dictionary;
+uInt dictLength;
+{
+    struct inflate_state FAR *state;
+    unsigned long dictid;
+    int ret;
+
+    /* check state */
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if (state->wrap != 0 && state->mode != DICT)
+        return Z_STREAM_ERROR;
+
+    /* check for correct dictionary identifier */
+    if (state->mode == DICT) {
+        dictid = adler32(0L, Z_NULL, 0);
+        dictid = adler32(dictid, dictionary, dictLength);
+        if (dictid != state->check)
+            return Z_DATA_ERROR;
+    }
+
+    /* copy dictionary to window using updatewindow(), which will amend the
+       existing dictionary if appropriate */
+    ret = updatewindow(strm, dictionary + dictLength, dictLength);
+    if (ret) {
+        state->mode = MEM;
+        return Z_MEM_ERROR;
+    }
+    state->havedict = 1;
+    Tracev((stderr, "inflate:   dictionary set\n"));
+    return Z_OK;
+}
+
+int ZEXPORT inflateGetHeader(strm, head)
+z_streamp strm;
+gz_headerp head;
+{
+    struct inflate_state FAR *state;
+
+    /* check state */
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;
+
+    /* save header structure */
+    state->head = head;
+    head->done = 0;
+    return Z_OK;
+}
+
+/*
+   Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff.  Return when found
+   or when out of input.  When called, *have is the number of pattern bytes
+   found in order so far, in 0..3.  On return *have is updated to the new
+   state.  If on return *have equals four, then the pattern was found and the
+   return value is how many bytes were read including the last byte of the
+   pattern.  If *have is less than four, then the pattern has not been found
+   yet and the return value is len.  In the latter case, syncsearch() can be
+   called again with more data and the *have state.  *have is initialized to
+   zero for the first call.
+ */
+local unsigned syncsearch(have, buf, len)
+unsigned FAR *have;
+const unsigned char FAR *buf;
+unsigned len;
+{
+    unsigned got;
+    unsigned next;
+
+    got = *have;
+    next = 0;
+    while (next < len && got < 4) {
+        if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
+            got++;
+        else if (buf[next])
+            got = 0;
+        else
+            got = 4 - got;
+        next++;
+    }
+    *have = got;
+    return next;
+}
+
+int ZEXPORT inflateSync(strm)
+z_streamp strm;
+{
+    unsigned len;               /* number of bytes to look at or looked at */
+    unsigned long in, out;      /* temporary to save total_in and total_out */
+    unsigned char buf[4];       /* to restore bit buffer to byte string */
+    struct inflate_state FAR *state;
+
+    /* check parameters */
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;
+
+    /* if first time, start search in bit buffer */
+    if (state->mode != SYNC) {
+        state->mode = SYNC;
+        state->hold <<= state->bits & 7;
+        state->bits -= state->bits & 7;
+        len = 0;
+        while (state->bits >= 8) {
+            buf[len++] = (unsigned char)(state->hold);
+            state->hold >>= 8;
+            state->bits -= 8;
+        }
+        state->have = 0;
+        syncsearch(&(state->have), buf, len);
+    }
+
+    /* search available input */
+    len = syncsearch(&(state->have), strm->next_in, strm->avail_in);
+    strm->avail_in -= len;
+    strm->next_in += len;
+    strm->total_in += len;
+
+    /* return no joy or set up to restart inflate() on a new block */
+    if (state->have != 4) return Z_DATA_ERROR;
+    in = strm->total_in;  out = strm->total_out;
+    inflateReset(strm);
+    strm->total_in = in;  strm->total_out = out;
+    state->mode = TYPE;
+    return Z_OK;
+}
+
+/*
+   Returns true if inflate is currently at the end of a block generated by
+   Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
+   implementation to provide an additional safety check. PPP uses
+   Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
+   block. When decompressing, PPP checks that at the end of input packet,
+   inflate is waiting for these length bytes.
+ */
+int ZEXPORT inflateSyncPoint(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    return state->mode == STORED && state->bits == 0;
+}
+
+int ZEXPORT inflateCopy(dest, source)
+z_streamp dest;
+z_streamp source;
+{
+    struct inflate_state FAR *state;
+    struct inflate_state FAR *copy;
+    unsigned char FAR *window;
+    unsigned wsize;
+
+    /* check input */
+    if (inflateStateCheck(source) || dest == Z_NULL)
+        return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)source->state;
+
+    /* allocate space */
+    copy = (struct inflate_state FAR *)
+           ZALLOC(source, 1, sizeof(struct inflate_state));
+    if (copy == Z_NULL) return Z_MEM_ERROR;
+    window = Z_NULL;
+    if (state->window != Z_NULL) {
+        window = (unsigned char FAR *)
+                 ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
+        if (window == Z_NULL) {
+            ZFREE(source, copy);
+            return Z_MEM_ERROR;
+        }
+    }
+
+    /* copy state */
+    zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
+    zmemcpy((voidpf)copy, (voidpf)state, sizeof(struct inflate_state));
+    copy->strm = dest;
+    if (state->lencode >= state->codes &&
+        state->lencode <= state->codes + ENOUGH - 1) {
+        copy->lencode = copy->codes + (state->lencode - state->codes);
+        copy->distcode = copy->codes + (state->distcode - state->codes);
+    }
+    copy->next = copy->codes + (state->next - state->codes);
+    if (window != Z_NULL) {
+        wsize = 1U << state->wbits;
+        zmemcpy(window, state->window, wsize);
+    }
+    copy->window = window;
+    dest->state = (struct internal_state FAR *)copy;
+    return Z_OK;
+}
+
+int ZEXPORT inflateUndermine(strm, subvert)
+z_streamp strm;
+int subvert;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
+    state->sane = !subvert;
+    return Z_OK;
+#else
+    (void)subvert;
+    state->sane = 1;
+    return Z_DATA_ERROR;
+#endif
+}
+
+int ZEXPORT inflateValidate(strm, check)
+z_streamp strm;
+int check;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if (check)
+        state->wrap |= 4;
+    else
+        state->wrap &= ~4;
+    return Z_OK;
+}
+
+long ZEXPORT inflateMark(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm))
+        return -(1L << 16);
+    state = (struct inflate_state FAR *)strm->state;
+    return (long)(((unsigned long)((long)state->back)) << 16) +
+        (state->mode == COPY ? state->length :
+            (state->mode == MATCH ? state->was - state->length : 0));
+}
+
+unsigned long ZEXPORT inflateCodesUsed(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+    if (inflateStateCheck(strm)) return (unsigned long)-1;
+    state = (struct inflate_state FAR *)strm->state;
+    return (unsigned long)(state->next - state->codes);
+}

vendor/libgit2-sys/libgit2/deps/zlib/inflate.h

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/inflate.h b/vendor/libgit2-sys/libgit2/deps/zlib/inflate.h
new file mode 100644
index 0000000..a46cce6
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/inflate.h
@@ -0,0 +1,125 @@
+/* inflate.h -- internal inflate state definition
+ * Copyright (C) 1995-2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* define NO_GZIP when compiling if you want to disable gzip header and
+   trailer decoding by inflate().  NO_GZIP would be used to avoid linking in
+   the crc code when it is not needed.  For shared libraries, gzip decoding
+   should be left enabled. */
+#ifndef NO_GZIP
+#  define GUNZIP
+#endif
+
+/* Possible inflate modes between inflate() calls */
+typedef enum {
+    HEAD = 16180,   /* i: waiting for magic header */
+    FLAGS,      /* i: waiting for method and flags (gzip) */
+    TIME,       /* i: waiting for modification time (gzip) */
+    OS,         /* i: waiting for extra flags and operating system (gzip) */
+    EXLEN,      /* i: waiting for extra length (gzip) */
+    EXTRA,      /* i: waiting for extra bytes (gzip) */
+    NAME,       /* i: waiting for end of file name (gzip) */
+    COMMENT,    /* i: waiting for end of comment (gzip) */
+    HCRC,       /* i: waiting for header crc (gzip) */
+    DICTID,     /* i: waiting for dictionary check value */
+    DICT,       /* waiting for inflateSetDictionary() call */
+        TYPE,       /* i: waiting for type bits, including last-flag bit */
+        TYPEDO,     /* i: same, but skip check to exit inflate on new block */
+        STORED,     /* i: waiting for stored size (length and complement) */
+        COPY_,      /* i/o: same as COPY below, but only first time in */
+        COPY,       /* i/o: waiting for input or output to copy stored block */
+        TABLE,      /* i: waiting for dynamic block table lengths */
+        LENLENS,    /* i: waiting for code length code lengths */
+        CODELENS,   /* i: waiting for length/lit and distance code lengths */
+            LEN_,       /* i: same as LEN below, but only first time in */
+            LEN,        /* i: waiting for length/lit/eob code */
+            LENEXT,     /* i: waiting for length extra bits */
+            DIST,       /* i: waiting for distance code */
+            DISTEXT,    /* i: waiting for distance extra bits */
+            MATCH,      /* o: waiting for output space to copy string */
+            LIT,        /* o: waiting for output space to write literal */
+    CHECK,      /* i: waiting for 32-bit check value */
+    LENGTH,     /* i: waiting for 32-bit length (gzip) */
+    DONE,       /* finished check, done -- remain here until reset */
+    BAD,        /* got a data error -- remain here until reset */
+    MEM,        /* got an inflate() memory error -- remain here until reset */
+    SYNC        /* looking for synchronization bytes to restart inflate() */
+} inflate_mode;
+
+/*
+    State transitions between above modes -
+
+    (most modes can go to BAD or MEM on error -- not shown for clarity)
+
+    Process header:
+        HEAD -> (gzip) or (zlib) or (raw)
+        (gzip) -> FLAGS -> TIME -> OS -> EXLEN -> EXTRA -> NAME -> COMMENT ->
+                  HCRC -> TYPE
+        (zlib) -> DICTID or TYPE
+        DICTID -> DICT -> TYPE
+        (raw) -> TYPEDO
+    Read deflate blocks:
+            TYPE -> TYPEDO -> STORED or TABLE or LEN_ or CHECK
+            STORED -> COPY_ -> COPY -> TYPE
+            TABLE -> LENLENS -> CODELENS -> LEN_
+            LEN_ -> LEN
+    Read deflate codes in fixed or dynamic block:
+                LEN -> LENEXT or LIT or TYPE
+                LENEXT -> DIST -> DISTEXT -> MATCH -> LEN
+                LIT -> LEN
+    Process trailer:
+        CHECK -> LENGTH -> DONE
+ */
+
+/* State maintained between inflate() calls -- approximately 7K bytes, not
+   including the allocated sliding window, which is up to 32K bytes. */
+struct inflate_state {
+    z_streamp strm;             /* pointer back to this zlib stream */
+    inflate_mode mode;          /* current inflate mode */
+    int last;                   /* true if processing last block */
+    int wrap;                   /* bit 0 true for zlib, bit 1 true for gzip,
+                                   bit 2 true to validate check value */
+    int havedict;               /* true if dictionary provided */
+    int flags;                  /* gzip header method and flags (0 if zlib) */
+    unsigned dmax;              /* zlib header max distance (INFLATE_STRICT) */
+    unsigned long check;        /* protected copy of check value */
+    unsigned long total;        /* protected copy of output count */
+    gz_headerp head;            /* where to save gzip header information */
+        /* sliding window */
+    unsigned wbits;             /* log base 2 of requested window size */
+    unsigned wsize;             /* window size or zero if not using window */
+    unsigned whave;             /* valid bytes in the window */
+    unsigned wnext;             /* window write index */
+    unsigned char FAR *window;  /* allocated sliding window, if needed */
+        /* bit accumulator */
+    unsigned long hold;         /* input bit accumulator */
+    unsigned bits;              /* number of bits in "in" */
+        /* for string and stored block copying */
+    unsigned length;            /* literal or length of data to copy */
+    unsigned offset;            /* distance back to copy string from */
+        /* for table and code decoding */
+    unsigned extra;             /* extra bits needed */
+        /* fixed and dynamic code tables */
+    code const FAR *lencode;    /* starting table for length/literal codes */
+    code const FAR *distcode;   /* starting table for distance codes */
+    unsigned lenbits;           /* index bits for lencode */
+    unsigned distbits;          /* index bits for distcode */
+        /* dynamic table building */
+    unsigned ncode;             /* number of code length code lengths */
+    unsigned nlen;              /* number of length code lengths */
+    unsigned ndist;             /* number of distance code lengths */
+    unsigned have;              /* number of code lengths in lens[] */
+    code FAR *next;             /* next available space in codes[] */
+    unsigned short lens[320];   /* temporary storage for code lengths */
+    unsigned short work[288];   /* work area for code table building */
+    code codes[ENOUGH];         /* space for code tables */
+    int sane;                   /* if false, allow invalid distance too far */
+    int back;                   /* bits back of last unprocessed length/lit */
+    unsigned was;               /* initial length of match */
+};

vendor/libgit2-sys/libgit2/deps/zlib/inftrees.c

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/inftrees.c b/vendor/libgit2-sys/libgit2/deps/zlib/inftrees.c
new file mode 100644
index 0000000..2ea08fc
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/inftrees.c
@@ -0,0 +1,304 @@
+/* inftrees.c -- generate Huffman trees for efficient decoding
+ * Copyright (C) 1995-2017 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "zutil.h"
+#include "inftrees.h"
+
+#define MAXBITS 15
+
+const char inflate_copyright[] =
+   " inflate 1.2.11 Copyright 1995-2017 Mark Adler ";
+/*
+  If you use the zlib library in a product, an acknowledgment is welcome
+  in the documentation of your product. If for some reason you cannot
+  include such an acknowledgment, I would appreciate that you keep this
+  copyright string in the executable of your product.
+ */
+
+/*
+   Build a set of tables to decode the provided canonical Huffman code.
+   The code lengths are lens[0..codes-1].  The result starts at *table,
+   whose indices are 0..2^bits-1.  work is a writable array of at least
+   lens shorts, which is used as a work area.  type is the type of code
+   to be generated, CODES, LENS, or DISTS.  On return, zero is success,
+   -1 is an invalid code, and +1 means that ENOUGH isn't enough.  table
+   on return points to the next available entry's address.  bits is the
+   requested root table index bits, and on return it is the actual root
+   table index bits.  It will differ if the request is greater than the
+   longest code or if it is less than the shortest code.
+ */
+int ZLIB_INTERNAL inflate_table(type, lens, codes, table, bits, work)
+codetype type;
+unsigned short FAR *lens;
+unsigned codes;
+code FAR * FAR *table;
+unsigned FAR *bits;
+unsigned short FAR *work;
+{
+    unsigned len;               /* a code's length in bits */
+    unsigned sym;               /* index of code symbols */
+    unsigned min, max;          /* minimum and maximum code lengths */
+    unsigned root;              /* number of index bits for root table */
+    unsigned curr;              /* number of index bits for current table */
+    unsigned drop;              /* code bits to drop for sub-table */
+    int left;                   /* number of prefix codes available */
+    unsigned used;              /* code entries in table used */
+    unsigned huff;              /* Huffman code */
+    unsigned incr;              /* for incrementing code, index */
+    unsigned fill;              /* index for replicating entries */
+    unsigned low;               /* low bits for current root entry */
+    unsigned mask;              /* mask for low root bits */
+    code here;                  /* table entry for duplication */
+    code FAR *next;             /* next available space in table */
+    const unsigned short FAR *base;     /* base value table to use */
+    const unsigned short FAR *extra;    /* extra bits table to use */
+    unsigned match;             /* use base and extra for symbol >= match */
+    unsigned short count[MAXBITS+1];    /* number of codes of each length */
+    unsigned short offs[MAXBITS+1];     /* offsets in table for each length */
+    static const unsigned short lbase[31] = { /* Length codes 257..285 base */
+        3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
+        35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
+    static const unsigned short lext[31] = { /* Length codes 257..285 extra */
+        16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18,
+        19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 16, 77, 202};
+    static const unsigned short dbase[32] = { /* Distance codes 0..29 base */
+        1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
+        257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
+        8193, 12289, 16385, 24577, 0, 0};
+    static const unsigned short dext[32] = { /* Distance codes 0..29 extra */
+        16, 16, 16, 16, 17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22,
+        23, 23, 24, 24, 25, 25, 26, 26, 27, 27,
+        28, 28, 29, 29, 64, 64};
+
+    /*
+       Process a set of code lengths to create a canonical Huffman code.  The
+       code lengths are lens[0..codes-1].  Each length corresponds to the
+       symbols 0..codes-1.  The Huffman code is generated by first sorting the
+       symbols by length from short to long, and retaining the symbol order
+       for codes with equal lengths.  Then the code starts with all zero bits
+       for the first code of the shortest length, and the codes are integer
+       increments for the same length, and zeros are appended as the length
+       increases.  For the deflate format, these bits are stored backwards
+       from their more natural integer increment ordering, and so when the
+       decoding tables are built in the large loop below, the integer codes
+       are incremented backwards.
+
+       This routine assumes, but does not check, that all of the entries in
+       lens[] are in the range 0..MAXBITS.  The caller must assure this.
+       1..MAXBITS is interpreted as that code length.  zero means that that
+       symbol does not occur in this code.
+
+       The codes are sorted by computing a count of codes for each length,
+       creating from that a table of starting indices for each length in the
+       sorted table, and then entering the symbols in order in the sorted
+       table.  The sorted table is work[], with that space being provided by
+       the caller.
+
+       The length counts are used for other purposes as well, i.e. finding
+       the minimum and maximum length codes, determining if there are any
+       codes at all, checking for a valid set of lengths, and looking ahead
+       at length counts to determine sub-table sizes when building the
+       decoding tables.
+     */
+
+    /* accumulate lengths for codes (assumes lens[] all in 0..MAXBITS) */
+    for (len = 0; len <= MAXBITS; len++)
+        count[len] = 0;
+    for (sym = 0; sym < codes; sym++)
+        count[lens[sym]]++;
+
+    /* bound code lengths, force root to be within code lengths */
+    root = *bits;
+    for (max = MAXBITS; max >= 1; max--)
+        if (count[max] != 0) break;
+    if (root > max) root = max;
+    if (max == 0) {                     /* no symbols to code at all */
+        here.op = (unsigned char)64;    /* invalid code marker */
+        here.bits = (unsigned char)1;
+        here.val = (unsigned short)0;
+        *(*table)++ = here;             /* make a table to force an error */
+        *(*table)++ = here;
+        *bits = 1;
+        return 0;     /* no symbols, but wait for decoding to report error */
+    }
+    for (min = 1; min < max; min++)
+        if (count[min] != 0) break;
+    if (root < min) root = min;
+
+    /* check for an over-subscribed or incomplete set of lengths */
+    left = 1;
+    for (len = 1; len <= MAXBITS; len++) {
+        left <<= 1;
+        left -= count[len];
+        if (left < 0) return -1;        /* over-subscribed */
+    }
+    if (left > 0 && (type == CODES || max != 1))
+        return -1;                      /* incomplete set */
+
+    /* generate offsets into symbol table for each length for sorting */
+    offs[1] = 0;
+    for (len = 1; len < MAXBITS; len++)
+        offs[len + 1] = offs[len] + count[len];
+
+    /* sort symbols by length, by symbol order within each length */
+    for (sym = 0; sym < codes; sym++)
+        if (lens[sym] != 0) work[offs[lens[sym]]++] = (unsigned short)sym;
+
+    /*
+       Create and fill in decoding tables.  In this loop, the table being
+       filled is at next and has curr index bits.  The code being used is huff
+       with length len.  That code is converted to an index by dropping drop
+       bits off of the bottom.  For codes where len is less than drop + curr,
+       those top drop + curr - len bits are incremented through all values to
+       fill the table with replicated entries.
+
+       root is the number of index bits for the root table.  When len exceeds
+       root, sub-tables are created pointed to by the root entry with an index
+       of the low root bits of huff.  This is saved in low to check for when a
+       new sub-table should be started.  drop is zero when the root table is
+       being filled, and drop is root when sub-tables are being filled.
+
+       When a new sub-table is needed, it is necessary to look ahead in the
+       code lengths to determine what size sub-table is needed.  The length
+       counts are used for this, and so count[] is decremented as codes are
+       entered in the tables.
+
+       used keeps track of how many table entries have been allocated from the
+       provided *table space.  It is checked for LENS and DIST tables against
+       the constants ENOUGH_LENS and ENOUGH_DISTS to guard against changes in
+       the initial root table size constants.  See the comments in inftrees.h
+       for more information.
+
+       sym increments through all symbols, and the loop terminates when
+       all codes of length max, i.e. all codes, have been processed.  This
+       routine permits incomplete codes, so another loop after this one fills
+       in the rest of the decoding tables with invalid code markers.
+     */
+
+    /* set up for code type */
+    switch (type) {
+    case CODES:
+        base = extra = work;    /* dummy value--not used */
+        match = 20;
+        break;
+    case LENS:
+        base = lbase;
+        extra = lext;
+        match = 257;
+        break;
+    default:    /* DISTS */
+        base = dbase;
+        extra = dext;
+        match = 0;
+    }
+
+    /* initialize state for loop */
+    huff = 0;                   /* starting code */
+    sym = 0;                    /* starting code symbol */
+    len = min;                  /* starting code length */
+    next = *table;              /* current table to fill in */
+    curr = root;                /* current table index bits */
+    drop = 0;                   /* current bits to drop from code for index */
+    low = (unsigned)(-1);       /* trigger new sub-table when len > root */
+    used = 1U << root;          /* use root table entries */
+    mask = used - 1;            /* mask for comparing low */
+
+    /* check available table space */
+    if ((type == LENS && used > ENOUGH_LENS) ||
+        (type == DISTS && used > ENOUGH_DISTS))
+        return 1;
+
+    /* process all codes and make table entries */
+    for (;;) {
+        /* create table entry */
+        here.bits = (unsigned char)(len - drop);
+        if (work[sym] + 1U < match) {
+            here.op = (unsigned char)0;
+            here.val = work[sym];
+        }
+        else if (work[sym] >= match) {
+            here.op = (unsigned char)(extra[work[sym] - match]);
+            here.val = base[work[sym] - match];
+        }
+        else {
+            here.op = (unsigned char)(32 + 64);         /* end of block */
+            here.val = 0;
+        }
+
+        /* replicate for those indices with low len bits equal to huff */
+        incr = 1U << (len - drop);
+        fill = 1U << curr;
+        min = fill;                 /* save offset to next table */
+        do {
+            fill -= incr;
+            next[(huff >> drop) + fill] = here;
+        } while (fill != 0);
+
+        /* backwards increment the len-bit code huff */
+        incr = 1U << (len - 1);
+        while (huff & incr)
+            incr >>= 1;
+        if (incr != 0) {
+            huff &= incr - 1;
+            huff += incr;
+        }
+        else
+            huff = 0;
+
+        /* go to next symbol, update count, len */
+        sym++;
+        if (--(count[len]) == 0) {
+            if (len == max) break;
+            len = lens[work[sym]];
+        }
+
+        /* create new sub-table if needed */
+        if (len > root && (huff & mask) != low) {
+            /* if first time, transition to sub-tables */
+            if (drop == 0)
+                drop = root;
+
+            /* increment past last table */
+            next += min;            /* here min is 1 << curr */
+
+            /* determine length of next table */
+            curr = len - drop;
+            left = (int)(1 << curr);
+            while (curr + drop < max) {
+                left -= count[curr + drop];
+                if (left <= 0) break;
+                curr++;
+                left <<= 1;
+            }
+
+            /* check for enough space */
+            used += 1U << curr;
+            if ((type == LENS && used > ENOUGH_LENS) ||
+                (type == DISTS && used > ENOUGH_DISTS))
+                return 1;
+
+            /* point entry in root table to sub-table */
+            low = huff & mask;
+            (*table)[low].op = (unsigned char)curr;
+            (*table)[low].bits = (unsigned char)root;
+            (*table)[low].val = (unsigned short)(next - *table);
+        }
+    }
+
+    /* fill in remaining table entry if code is incomplete (guaranteed to have
+       at most one remaining entry, since if the code is incomplete, the
+       maximum code length that was allowed to get this far is one bit) */
+    if (huff != 0) {
+        here.op = (unsigned char)64;            /* invalid code marker */
+        here.bits = (unsigned char)(len - drop);
+        here.val = (unsigned short)0;
+        next[huff] = here;
+    }
+
+    /* set return parameters */
+    *table += used;
+    *bits = root;
+    return 0;
+}

vendor/libgit2-sys/libgit2/deps/zlib/inftrees.h

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/inftrees.h b/vendor/libgit2-sys/libgit2/deps/zlib/inftrees.h
new file mode 100644
index 0000000..baa53a0
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/inftrees.h
@@ -0,0 +1,62 @@
+/* inftrees.h -- header to use inftrees.c
+ * Copyright (C) 1995-2005, 2010 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* Structure for decoding tables.  Each entry provides either the
+   information needed to do the operation requested by the code that
+   indexed that table entry, or it provides a pointer to another
+   table that indexes more bits of the code.  op indicates whether
+   the entry is a pointer to another table, a literal, a length or
+   distance, an end-of-block, or an invalid code.  For a table
+   pointer, the low four bits of op is the number of index bits of
+   that table.  For a length or distance, the low four bits of op
+   is the number of extra bits to get after the code.  bits is
+   the number of bits in this code or part of the code to drop off
+   of the bit buffer.  val is the actual byte to output in the case
+   of a literal, the base length or distance, or the offset from
+   the current table to the next table.  Each entry is four bytes. */
+typedef struct {
+    unsigned char op;           /* operation, extra bits, table bits */
+    unsigned char bits;         /* bits in this part of the code */
+    unsigned short val;         /* offset in table or code value */
+} code;
+
+/* op values as set by inflate_table():
+    00000000 - literal
+    0000tttt - table link, tttt != 0 is the number of table index bits
+    0001eeee - length or distance, eeee is the number of extra bits
+    01100000 - end of block
+    01000000 - invalid code
+ */
+
+/* Maximum size of the dynamic table.  The maximum number of code structures is
+   1444, which is the sum of 852 for literal/length codes and 592 for distance
+   codes.  These values were found by exhaustive searches using the program
+   examples/enough.c found in the zlib distribtution.  The arguments to that
+   program are the number of symbols, the initial root table size, and the
+   maximum bit length of a code.  "enough 286 9 15" for literal/length codes
+   returns returns 852, and "enough 30 6 15" for distance codes returns 592.
+   The initial root table size (9 or 6) is found in the fifth argument of the
+   inflate_table() calls in inflate.c and infback.c.  If the root table size is
+   changed, then these maximum sizes would be need to be recalculated and
+   updated. */
+#define ENOUGH_LENS 852
+#define ENOUGH_DISTS 592
+#define ENOUGH (ENOUGH_LENS+ENOUGH_DISTS)
+
+/* Type of code to build for inflate_table() */
+typedef enum {
+    CODES,
+    LENS,
+    DISTS
+} codetype;
+
+int ZLIB_INTERNAL inflate_table OF((codetype type, unsigned short FAR *lens,
+                             unsigned codes, code FAR * FAR *table,
+                             unsigned FAR *bits, unsigned short FAR *work));

vendor/libgit2-sys/libgit2/deps/zlib/trees.c

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/trees.c b/vendor/libgit2-sys/libgit2/deps/zlib/trees.c
new file mode 100644
index 0000000..50cf4b4
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/trees.c
@@ -0,0 +1,1203 @@
+/* trees.c -- output deflated data using Huffman coding
+ * Copyright (C) 1995-2017 Jean-loup Gailly
+ * detect_data_type() function provided freely by Cosmin Truta, 2006
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/*
+ *  ALGORITHM
+ *
+ *      The "deflation" process uses several Huffman trees. The more
+ *      common source values are represented by shorter bit sequences.
+ *
+ *      Each code tree is stored in a compressed form which is itself
+ * a Huffman encoding of the lengths of all the code strings (in
+ * ascending order by source values).  The actual code strings are
+ * reconstructed from the lengths in the inflate process, as described
+ * in the deflate specification.
+ *
+ *  REFERENCES
+ *
+ *      Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
+ *      Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
+ *
+ *      Storer, James A.
+ *          Data Compression:  Methods and Theory, pp. 49-50.
+ *          Computer Science Press, 1988.  ISBN 0-7167-8156-5.
+ *
+ *      Sedgewick, R.
+ *          Algorithms, p290.
+ *          Addison-Wesley, 1983. ISBN 0-201-06672-6.
+ */
+
+/* @(#) $Id$ */
+
+/* #define GEN_TREES_H */
+
+#include "deflate.h"
+
+#ifdef ZLIB_DEBUG
+#  include <ctype.h>
+#endif
+
+/* ===========================================================================
+ * Constants
+ */
+
+#define MAX_BL_BITS 7
+/* Bit length codes must not exceed MAX_BL_BITS bits */
+
+#define END_BLOCK 256
+/* end of block literal code */
+
+#define REP_3_6      16
+/* repeat previous bit length 3-6 times (2 bits of repeat count) */
+
+#define REPZ_3_10    17
+/* repeat a zero length 3-10 times  (3 bits of repeat count) */
+
+#define REPZ_11_138  18
+/* repeat a zero length 11-138 times  (7 bits of repeat count) */
+
+local const int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
+   = {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0};
+
+local const int extra_dbits[D_CODES] /* extra bits for each distance code */
+   = {0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13};
+
+local const int extra_blbits[BL_CODES]/* extra bits for each bit length code */
+   = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
+
+local const uch bl_order[BL_CODES]
+   = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
+/* The lengths of the bit length codes are sent in order of decreasing
+ * probability, to avoid transmitting the lengths for unused bit length codes.
+ */
+
+/* ===========================================================================
+ * Local data. These are initialized only once.
+ */
+
+#define DIST_CODE_LEN  512 /* see definition of array dist_code below */
+
+#if defined(GEN_TREES_H) || !defined(STDC)
+/* non ANSI compilers may not accept trees.h */
+
+local ct_data static_ltree[L_CODES+2];
+/* The static literal tree. Since the bit lengths are imposed, there is no
+ * need for the L_CODES extra codes used during heap construction. However
+ * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
+ * below).
+ */
+
+local ct_data static_dtree[D_CODES];
+/* The static distance tree. (Actually a trivial tree since all codes use
+ * 5 bits.)
+ */
+
+uch _dist_code[DIST_CODE_LEN];
+/* Distance codes. The first 256 values correspond to the distances
+ * 3 .. 258, the last 256 values correspond to the top 8 bits of
+ * the 15 bit distances.
+ */
+
+uch _length_code[MAX_MATCH-MIN_MATCH+1];
+/* length code for each normalized match length (0 == MIN_MATCH) */
+
+local int base_length[LENGTH_CODES];
+/* First normalized length for each code (0 = MIN_MATCH) */
+
+local int base_dist[D_CODES];
+/* First normalized distance for each code (0 = distance of 1) */
+
+#else
+#  include "trees.h"
+#endif /* GEN_TREES_H */
+
+struct static_tree_desc_s {
+    const ct_data *static_tree;  /* static tree or NULL */
+    const intf *extra_bits;      /* extra bits for each code or NULL */
+    int     extra_base;          /* base index for extra_bits */
+    int     elems;               /* max number of elements in the tree */
+    int     max_length;          /* max bit length for the codes */
+};
+
+local const static_tree_desc  static_l_desc =
+{static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
+
+local const static_tree_desc  static_d_desc =
+{static_dtree, extra_dbits, 0,          D_CODES, MAX_BITS};
+
+local const static_tree_desc  static_bl_desc =
+{(const ct_data *)0, extra_blbits, 0,   BL_CODES, MAX_BL_BITS};
+
+/* ===========================================================================
+ * Local (static) routines in this file.
+ */
+
+local void tr_static_init OF((void));
+local void init_block     OF((deflate_state *s));
+local void pqdownheap     OF((deflate_state *s, ct_data *tree, int k));
+local void gen_bitlen     OF((deflate_state *s, tree_desc *desc));
+local void gen_codes      OF((ct_data *tree, int max_code, ushf *bl_count));
+local void build_tree     OF((deflate_state *s, tree_desc *desc));
+local void scan_tree      OF((deflate_state *s, ct_data *tree, int max_code));
+local void send_tree      OF((deflate_state *s, ct_data *tree, int max_code));
+local int  build_bl_tree  OF((deflate_state *s));
+local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
+                              int blcodes));
+local void compress_block OF((deflate_state *s, const ct_data *ltree,
+                              const ct_data *dtree));
+local int  detect_data_type OF((deflate_state *s));
+local unsigned bi_reverse OF((unsigned value, int length));
+local void bi_windup      OF((deflate_state *s));
+local void bi_flush       OF((deflate_state *s));
+
+#ifdef GEN_TREES_H
+local void gen_trees_header OF((void));
+#endif
+
+#ifndef ZLIB_DEBUG
+#  define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
+   /* Send a code of the given tree. c and tree must not have side effects */
+
+#else /* !ZLIB_DEBUG */
+#  define send_code(s, c, tree) \
+     { if (z_verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
+       send_bits(s, tree[c].Code, tree[c].Len); }
+#endif
+
+/* ===========================================================================
+ * Output a short LSB first on the stream.
+ * IN assertion: there is enough room in pendingBuf.
+ */
+#define put_short(s, w) { \
+    put_byte(s, (uch)((w) & 0xff)); \
+    put_byte(s, (uch)((ush)(w) >> 8)); \
+}
+
+/* ===========================================================================
+ * Send a value on a given number of bits.
+ * IN assertion: length <= 16 and value fits in length bits.
+ */
+#ifdef ZLIB_DEBUG
+local void send_bits      OF((deflate_state *s, int value, int length));
+
+local void send_bits(s, value, length)
+    deflate_state *s;
+    int value;  /* value to send */
+    int length; /* number of bits */
+{
+    Tracevv((stderr," l %2d v %4x ", length, value));
+    Assert(length > 0 && length <= 15, "invalid length");
+    s->bits_sent += (ulg)length;
+
+    /* If not enough room in bi_buf, use (valid) bits from bi_buf and
+     * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
+     * unused bits in value.
+     */
+    if (s->bi_valid > (int)Buf_size - length) {
+        s->bi_buf |= (ush)value << s->bi_valid;
+        put_short(s, s->bi_buf);
+        s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
+        s->bi_valid += length - Buf_size;
+    } else {
+        s->bi_buf |= (ush)value << s->bi_valid;
+        s->bi_valid += length;
+    }
+}
+#else /* !ZLIB_DEBUG */
+
+#define send_bits(s, value, length) \
+{ int len = length;\
+  if (s->bi_valid > (int)Buf_size - len) {\
+    int val = (int)value;\
+    s->bi_buf |= (ush)val << s->bi_valid;\
+    put_short(s, s->bi_buf);\
+    s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
+    s->bi_valid += len - Buf_size;\
+  } else {\
+    s->bi_buf |= (ush)(value) << s->bi_valid;\
+    s->bi_valid += len;\
+  }\
+}
+#endif /* ZLIB_DEBUG */
+
+
+/* the arguments must not have side effects */
+
+/* ===========================================================================
+ * Initialize the various 'constant' tables.
+ */
+local void tr_static_init()
+{
+#if defined(GEN_TREES_H) || !defined(STDC)
+    static int static_init_done = 0;
+    int n;        /* iterates over tree elements */
+    int bits;     /* bit counter */
+    int length;   /* length value */
+    int code;     /* code value */
+    int dist;     /* distance index */
+    ush bl_count[MAX_BITS+1];
+    /* number of codes at each bit length for an optimal tree */
+
+    if (static_init_done) return;
+
+    /* For some embedded targets, global variables are not initialized: */
+#ifdef NO_INIT_GLOBAL_POINTERS
+    static_l_desc.static_tree = static_ltree;
+    static_l_desc.extra_bits = extra_lbits;
+    static_d_desc.static_tree = static_dtree;
+    static_d_desc.extra_bits = extra_dbits;
+    static_bl_desc.extra_bits = extra_blbits;
+#endif
+
+    /* Initialize the mapping length (0..255) -> length code (0..28) */
+    length = 0;
+    for (code = 0; code < LENGTH_CODES-1; code++) {
+        base_length[code] = length;
+        for (n = 0; n < (1<<extra_lbits[code]); n++) {
+            _length_code[length++] = (uch)code;
+        }
+    }
+    Assert (length == 256, "tr_static_init: length != 256");
+    /* Note that the length 255 (match length 258) can be represented
+     * in two different ways: code 284 + 5 bits or code 285, so we
+     * overwrite length_code[255] to use the best encoding:
+     */
+    _length_code[length-1] = (uch)code;
+
+    /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
+    dist = 0;
+    for (code = 0 ; code < 16; code++) {
+        base_dist[code] = dist;
+        for (n = 0; n < (1<<extra_dbits[code]); n++) {
+            _dist_code[dist++] = (uch)code;
+        }
+    }
+    Assert (dist == 256, "tr_static_init: dist != 256");
+    dist >>= 7; /* from now on, all distances are divided by 128 */
+    for ( ; code < D_CODES; code++) {
+        base_dist[code] = dist << 7;
+        for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
+            _dist_code[256 + dist++] = (uch)code;
+        }
+    }
+    Assert (dist == 256, "tr_static_init: 256+dist != 512");
+
+    /* Construct the codes of the static literal tree */
+    for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
+    n = 0;
+    while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
+    while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
+    while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
+    while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
+    /* Codes 286 and 287 do not exist, but we must include them in the
+     * tree construction to get a canonical Huffman tree (longest code
+     * all ones)
+     */
+    gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
+
+    /* The static distance tree is trivial: */
+    for (n = 0; n < D_CODES; n++) {
+        static_dtree[n].Len = 5;
+        static_dtree[n].Code = bi_reverse((unsigned)n, 5);
+    }
+    static_init_done = 1;
+
+#  ifdef GEN_TREES_H
+    gen_trees_header();
+#  endif
+#endif /* defined(GEN_TREES_H) || !defined(STDC) */
+}
+
+/* ===========================================================================
+ * Genererate the file trees.h describing the static trees.
+ */
+#ifdef GEN_TREES_H
+#  ifndef ZLIB_DEBUG
+#    include <stdio.h>
+#  endif
+
+#  define SEPARATOR(i, last, width) \
+      ((i) == (last)? "\n};\n\n" :    \
+       ((i) % (width) == (width)-1 ? ",\n" : ", "))
+
+void gen_trees_header()
+{
+    FILE *header = fopen("trees.h", "w");
+    int i;
+
+    Assert (header != NULL, "Can't open trees.h");
+    fprintf(header,
+            "/* header created automatically with -DGEN_TREES_H */\n\n");
+
+    fprintf(header, "local const ct_data static_ltree[L_CODES+2] = {\n");
+    for (i = 0; i < L_CODES+2; i++) {
+        fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code,
+                static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5));
+    }
+
+    fprintf(header, "local const ct_data static_dtree[D_CODES] = {\n");
+    for (i = 0; i < D_CODES; i++) {
+        fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code,
+                static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5));
+    }
+
+    fprintf(header, "const uch ZLIB_INTERNAL _dist_code[DIST_CODE_LEN] = {\n");
+    for (i = 0; i < DIST_CODE_LEN; i++) {
+        fprintf(header, "%2u%s", _dist_code[i],
+                SEPARATOR(i, DIST_CODE_LEN-1, 20));
+    }
+
+    fprintf(header,
+        "const uch ZLIB_INTERNAL _length_code[MAX_MATCH-MIN_MATCH+1]= {\n");
+    for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) {
+        fprintf(header, "%2u%s", _length_code[i],
+                SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20));
+    }
+
+    fprintf(header, "local const int base_length[LENGTH_CODES] = {\n");
+    for (i = 0; i < LENGTH_CODES; i++) {
+        fprintf(header, "%1u%s", base_length[i],
+                SEPARATOR(i, LENGTH_CODES-1, 20));
+    }
+
+    fprintf(header, "local const int base_dist[D_CODES] = {\n");
+    for (i = 0; i < D_CODES; i++) {
+        fprintf(header, "%5u%s", base_dist[i],
+                SEPARATOR(i, D_CODES-1, 10));
+    }
+
+    fclose(header);
+}
+#endif /* GEN_TREES_H */
+
+/* ===========================================================================
+ * Initialize the tree data structures for a new zlib stream.
+ */
+void ZLIB_INTERNAL _tr_init(s)
+    deflate_state *s;
+{
+    tr_static_init();
+
+    s->l_desc.dyn_tree = s->dyn_ltree;
+    s->l_desc.stat_desc = &static_l_desc;
+
+    s->d_desc.dyn_tree = s->dyn_dtree;
+    s->d_desc.stat_desc = &static_d_desc;
+
+    s->bl_desc.dyn_tree = s->bl_tree;
+    s->bl_desc.stat_desc = &static_bl_desc;
+
+    s->bi_buf = 0;
+    s->bi_valid = 0;
+#ifdef ZLIB_DEBUG
+    s->compressed_len = 0L;
+    s->bits_sent = 0L;
+#endif
+
+    /* Initialize the first block of the first file: */
+    init_block(s);
+}
+
+/* ===========================================================================
+ * Initialize a new block.
+ */
+local void init_block(s)
+    deflate_state *s;
+{
+    int n; /* iterates over tree elements */
+
+    /* Initialize the trees. */
+    for (n = 0; n < L_CODES;  n++) s->dyn_ltree[n].Freq = 0;
+    for (n = 0; n < D_CODES;  n++) s->dyn_dtree[n].Freq = 0;
+    for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
+
+    s->dyn_ltree[END_BLOCK].Freq = 1;
+    s->opt_len = s->static_len = 0L;
+    s->last_lit = s->matches = 0;
+}
+
+#define SMALLEST 1
+/* Index within the heap array of least frequent node in the Huffman tree */
+
+
+/* ===========================================================================
+ * Remove the smallest element from the heap and recreate the heap with
+ * one less element. Updates heap and heap_len.
+ */
+#define pqremove(s, tree, top) \
+{\
+    top = s->heap[SMALLEST]; \
+    s->heap[SMALLEST] = s->heap[s->heap_len--]; \
+    pqdownheap(s, tree, SMALLEST); \
+}
+
+/* ===========================================================================
+ * Compares to subtrees, using the tree depth as tie breaker when
+ * the subtrees have equal frequency. This minimizes the worst case length.
+ */
+#define smaller(tree, n, m, depth) \
+   (tree[n].Freq < tree[m].Freq || \
+   (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
+
+/* ===========================================================================
+ * Restore the heap property by moving down the tree starting at node k,
+ * exchanging a node with the smallest of its two sons if necessary, stopping
+ * when the heap property is re-established (each father smaller than its
+ * two sons).
+ */
+local void pqdownheap(s, tree, k)
+    deflate_state *s;
+    ct_data *tree;  /* the tree to restore */
+    int k;               /* node to move down */
+{
+    int v = s->heap[k];
+    int j = k << 1;  /* left son of k */
+    while (j <= s->heap_len) {
+        /* Set j to the smallest of the two sons: */
+        if (j < s->heap_len &&
+            smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
+            j++;
+        }
+        /* Exit if v is smaller than both sons */
+        if (smaller(tree, v, s->heap[j], s->depth)) break;
+
+        /* Exchange v with the smallest son */
+        s->heap[k] = s->heap[j];  k = j;
+
+        /* And continue down the tree, setting j to the left son of k */
+        j <<= 1;
+    }
+    s->heap[k] = v;
+}
+
+/* ===========================================================================
+ * Compute the optimal bit lengths for a tree and update the total bit length
+ * for the current block.
+ * IN assertion: the fields freq and dad are set, heap[heap_max] and
+ *    above are the tree nodes sorted by increasing frequency.
+ * OUT assertions: the field len is set to the optimal bit length, the
+ *     array bl_count contains the frequencies for each bit length.
+ *     The length opt_len is updated; static_len is also updated if stree is
+ *     not null.
+ */
+local void gen_bitlen(s, desc)
+    deflate_state *s;
+    tree_desc *desc;    /* the tree descriptor */
+{
+    ct_data *tree        = desc->dyn_tree;
+    int max_code         = desc->max_code;
+    const ct_data *stree = desc->stat_desc->static_tree;
+    const intf *extra    = desc->stat_desc->extra_bits;
+    int base             = desc->stat_desc->extra_base;
+    int max_length       = desc->stat_desc->max_length;
+    int h;              /* heap index */
+    int n, m;           /* iterate over the tree elements */
+    int bits;           /* bit length */
+    int xbits;          /* extra bits */
+    ush f;              /* frequency */
+    int overflow = 0;   /* number of elements with bit length too large */
+
+    for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
+
+    /* In a first pass, compute the optimal bit lengths (which may
+     * overflow in the case of the bit length tree).
+     */
+    tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
+
+    for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
+        n = s->heap[h];
+        bits = tree[tree[n].Dad].Len + 1;
+        if (bits > max_length) bits = max_length, overflow++;
+        tree[n].Len = (ush)bits;
+        /* We overwrite tree[n].Dad which is no longer needed */
+
+        if (n > max_code) continue; /* not a leaf node */
+
+        s->bl_count[bits]++;
+        xbits = 0;
+        if (n >= base) xbits = extra[n-base];
+        f = tree[n].Freq;
+        s->opt_len += (ulg)f * (unsigned)(bits + xbits);
+        if (stree) s->static_len += (ulg)f * (unsigned)(stree[n].Len + xbits);
+    }
+    if (overflow == 0) return;
+
+    Tracev((stderr,"\nbit length overflow\n"));
+    /* This happens for example on obj2 and pic of the Calgary corpus */
+
+    /* Find the first bit length which could increase: */
+    do {
+        bits = max_length-1;
+        while (s->bl_count[bits] == 0) bits--;
+        s->bl_count[bits]--;      /* move one leaf down the tree */
+        s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
+        s->bl_count[max_length]--;
+        /* The brother of the overflow item also moves one step up,
+         * but this does not affect bl_count[max_length]
+         */
+        overflow -= 2;
+    } while (overflow > 0);
+
+    /* Now recompute all bit lengths, scanning in increasing frequency.
+     * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
+     * lengths instead of fixing only the wrong ones. This idea is taken
+     * from 'ar' written by Haruhiko Okumura.)
+     */
+    for (bits = max_length; bits != 0; bits--) {
+        n = s->bl_count[bits];
+        while (n != 0) {
+            m = s->heap[--h];
+            if (m > max_code) continue;
+            if ((unsigned) tree[m].Len != (unsigned) bits) {
+                Tracev((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
+                s->opt_len += ((ulg)bits - tree[m].Len) * tree[m].Freq;
+                tree[m].Len = (ush)bits;
+            }
+            n--;
+        }
+    }
+}
+
+/* ===========================================================================
+ * Generate the codes for a given tree and bit counts (which need not be
+ * optimal).
+ * IN assertion: the array bl_count contains the bit length statistics for
+ * the given tree and the field len is set for all tree elements.
+ * OUT assertion: the field code is set for all tree elements of non
+ *     zero code length.
+ */
+local void gen_codes (tree, max_code, bl_count)
+    ct_data *tree;             /* the tree to decorate */
+    int max_code;              /* largest code with non zero frequency */
+    ushf *bl_count;            /* number of codes at each bit length */
+{
+    ush next_code[MAX_BITS+1]; /* next code value for each bit length */
+    unsigned code = 0;         /* running code value */
+    int bits;                  /* bit index */
+    int n;                     /* code index */
+
+    /* The distribution counts are first used to generate the code values
+     * without bit reversal.
+     */
+    for (bits = 1; bits <= MAX_BITS; bits++) {
+        code = (code + bl_count[bits-1]) << 1;
+        next_code[bits] = (ush)code;
+    }
+    /* Check that the bit counts in bl_count are consistent. The last code
+     * must be all ones.
+     */
+    Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
+            "inconsistent bit counts");
+    Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
+
+    for (n = 0;  n <= max_code; n++) {
+        int len = tree[n].Len;
+        if (len == 0) continue;
+        /* Now reverse the bits */
+        tree[n].Code = (ush)bi_reverse(next_code[len]++, len);
+
+        Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
+             n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
+    }
+}
+
+/* ===========================================================================
+ * Construct one Huffman tree and assigns the code bit strings and lengths.
+ * Update the total bit length for the current block.
+ * IN assertion: the field freq is set for all tree elements.
+ * OUT assertions: the fields len and code are set to the optimal bit length
+ *     and corresponding code. The length opt_len is updated; static_len is
+ *     also updated if stree is not null. The field max_code is set.
+ */
+local void build_tree(s, desc)
+    deflate_state *s;
+    tree_desc *desc; /* the tree descriptor */
+{
+    ct_data *tree         = desc->dyn_tree;
+    const ct_data *stree  = desc->stat_desc->static_tree;
+    int elems             = desc->stat_desc->elems;
+    int n, m;          /* iterate over heap elements */
+    int max_code = -1; /* largest code with non zero frequency */
+    int node;          /* new node being created */
+
+    /* Construct the initial heap, with least frequent element in
+     * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
+     * heap[0] is not used.
+     */
+    s->heap_len = 0, s->heap_max = HEAP_SIZE;
+
+    for (n = 0; n < elems; n++) {
+        if (tree[n].Freq != 0) {
+            s->heap[++(s->heap_len)] = max_code = n;
+            s->depth[n] = 0;
+        } else {
+            tree[n].Len = 0;
+        }
+    }
+
+    /* The pkzip format requires that at least one distance code exists,
+     * and that at least one bit should be sent even if there is only one
+     * possible code. So to avoid special checks later on we force at least
+     * two codes of non zero frequency.
+     */
+    while (s->heap_len < 2) {
+        node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
+        tree[node].Freq = 1;
+        s->depth[node] = 0;
+        s->opt_len--; if (stree) s->static_len -= stree[node].Len;
+        /* node is 0 or 1 so it does not have extra bits */
+    }
+    desc->max_code = max_code;
+
+    /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
+     * establish sub-heaps of increasing lengths:
+     */
+    for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
+
+    /* Construct the Huffman tree by repeatedly combining the least two
+     * frequent nodes.
+     */
+    node = elems;              /* next internal node of the tree */
+    do {
+        pqremove(s, tree, n);  /* n = node of least frequency */
+        m = s->heap[SMALLEST]; /* m = node of next least frequency */
+
+        s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
+        s->heap[--(s->heap_max)] = m;
+
+        /* Create a new node father of n and m */
+        tree[node].Freq = tree[n].Freq + tree[m].Freq;
+        s->depth[node] = (uch)((s->depth[n] >= s->depth[m] ?
+                                s->depth[n] : s->depth[m]) + 1);
+        tree[n].Dad = tree[m].Dad = (ush)node;
+#ifdef DUMP_BL_TREE
+        if (tree == s->bl_tree) {
+            fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
+                    node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
+        }
+#endif
+        /* and insert the new node in the heap */
+        s->heap[SMALLEST] = node++;
+        pqdownheap(s, tree, SMALLEST);
+
+    } while (s->heap_len >= 2);
+
+    s->heap[--(s->heap_max)] = s->heap[SMALLEST];
+
+    /* At this point, the fields freq and dad are set. We can now
+     * generate the bit lengths.
+     */
+    gen_bitlen(s, (tree_desc *)desc);
+
+    /* The field len is now set, we can generate the bit codes */
+    gen_codes ((ct_data *)tree, max_code, s->bl_count);
+}
+
+/* ===========================================================================
+ * Scan a literal or distance tree to determine the frequencies of the codes
+ * in the bit length tree.
+ */
+local void scan_tree (s, tree, max_code)
+    deflate_state *s;
+    ct_data *tree;   /* the tree to be scanned */
+    int max_code;    /* and its largest code of non zero frequency */
+{
+    int n;                     /* iterates over all tree elements */
+    int prevlen = -1;          /* last emitted length */
+    int curlen;                /* length of current code */
+    int nextlen = tree[0].Len; /* length of next code */
+    int count = 0;             /* repeat count of the current code */
+    int max_count = 7;         /* max repeat count */
+    int min_count = 4;         /* min repeat count */
+
+    if (nextlen == 0) max_count = 138, min_count = 3;
+    tree[max_code+1].Len = (ush)0xffff; /* guard */
+
+    for (n = 0; n <= max_code; n++) {
+        curlen = nextlen; nextlen = tree[n+1].Len;
+        if (++count < max_count && curlen == nextlen) {
+            continue;
+        } else if (count < min_count) {
+            s->bl_tree[curlen].Freq += count;
+        } else if (curlen != 0) {
+            if (curlen != prevlen) s->bl_tree[curlen].Freq++;
+            s->bl_tree[REP_3_6].Freq++;
+        } else if (count <= 10) {
+            s->bl_tree[REPZ_3_10].Freq++;
+        } else {
+            s->bl_tree[REPZ_11_138].Freq++;
+        }
+        count = 0; prevlen = curlen;
+        if (nextlen == 0) {
+            max_count = 138, min_count = 3;
+        } else if (curlen == nextlen) {
+            max_count = 6, min_count = 3;
+        } else {
+            max_count = 7, min_count = 4;
+        }
+    }
+}
+
+/* ===========================================================================
+ * Send a literal or distance tree in compressed form, using the codes in
+ * bl_tree.
+ */
+local void send_tree (s, tree, max_code)
+    deflate_state *s;
+    ct_data *tree; /* the tree to be scanned */
+    int max_code;       /* and its largest code of non zero frequency */
+{
+    int n;                     /* iterates over all tree elements */
+    int prevlen = -1;          /* last emitted length */
+    int curlen;                /* length of current code */
+    int nextlen = tree[0].Len; /* length of next code */
+    int count = 0;             /* repeat count of the current code */
+    int max_count = 7;         /* max repeat count */
+    int min_count = 4;         /* min repeat count */
+
+    /* tree[max_code+1].Len = -1; */  /* guard already set */
+    if (nextlen == 0) max_count = 138, min_count = 3;
+
+    for (n = 0; n <= max_code; n++) {
+        curlen = nextlen; nextlen = tree[n+1].Len;
+        if (++count < max_count && curlen == nextlen) {
+            continue;
+        } else if (count < min_count) {
+            do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
+
+        } else if (curlen != 0) {
+            if (curlen != prevlen) {
+                send_code(s, curlen, s->bl_tree); count--;
+            }
+            Assert(count >= 3 && count <= 6, " 3_6?");
+            send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
+
+        } else if (count <= 10) {
+            send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
+
+        } else {
+            send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
+        }
+        count = 0; prevlen = curlen;
+        if (nextlen == 0) {
+            max_count = 138, min_count = 3;
+        } else if (curlen == nextlen) {
+            max_count = 6, min_count = 3;
+        } else {
+            max_count = 7, min_count = 4;
+        }
+    }
+}
+
+/* ===========================================================================
+ * Construct the Huffman tree for the bit lengths and return the index in
+ * bl_order of the last bit length code to send.
+ */
+local int build_bl_tree(s)
+    deflate_state *s;
+{
+    int max_blindex;  /* index of last bit length code of non zero freq */
+
+    /* Determine the bit length frequencies for literal and distance trees */
+    scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
+    scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
+
+    /* Build the bit length tree: */
+    build_tree(s, (tree_desc *)(&(s->bl_desc)));
+    /* opt_len now includes the length of the tree representations, except
+     * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
+     */
+
+    /* Determine the number of bit length codes to send. The pkzip format
+     * requires that at least 4 bit length codes be sent. (appnote.txt says
+     * 3 but the actual value used is 4.)
+     */
+    for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
+        if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
+    }
+    /* Update opt_len to include the bit length tree and counts */
+    s->opt_len += 3*((ulg)max_blindex+1) + 5+5+4;
+    Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
+            s->opt_len, s->static_len));
+
+    return max_blindex;
+}
+
+/* ===========================================================================
+ * Send the header for a block using dynamic Huffman trees: the counts, the
+ * lengths of the bit length codes, the literal tree and the distance tree.
+ * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
+ */
+local void send_all_trees(s, lcodes, dcodes, blcodes)
+    deflate_state *s;
+    int lcodes, dcodes, blcodes; /* number of codes for each tree */
+{
+    int rank;                    /* index in bl_order */
+
+    Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
+    Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
+            "too many codes");
+    Tracev((stderr, "\nbl counts: "));
+    send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
+    send_bits(s, dcodes-1,   5);
+    send_bits(s, blcodes-4,  4); /* not -3 as stated in appnote.txt */
+    for (rank = 0; rank < blcodes; rank++) {
+        Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
+        send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
+    }
+    Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
+
+    send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
+    Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
+
+    send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
+    Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
+}
+
+/* ===========================================================================
+ * Send a stored block
+ */
+void ZLIB_INTERNAL _tr_stored_block(s, buf, stored_len, last)
+    deflate_state *s;
+    charf *buf;       /* input block */
+    ulg stored_len;   /* length of input block */
+    int last;         /* one if this is the last block for a file */
+{
+    send_bits(s, (STORED_BLOCK<<1)+last, 3);    /* send block type */
+    bi_windup(s);        /* align on byte boundary */
+    put_short(s, (ush)stored_len);
+    put_short(s, (ush)~stored_len);
+    zmemcpy(s->pending_buf + s->pending, (Bytef *)buf, stored_len);
+    s->pending += stored_len;
+#ifdef ZLIB_DEBUG
+    s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
+    s->compressed_len += (stored_len + 4) << 3;
+    s->bits_sent += 2*16;
+    s->bits_sent += stored_len<<3;
+#endif
+}
+
+/* ===========================================================================
+ * Flush the bits in the bit buffer to pending output (leaves at most 7 bits)
+ */
+void ZLIB_INTERNAL _tr_flush_bits(s)
+    deflate_state *s;
+{
+    bi_flush(s);
+}
+
+/* ===========================================================================
+ * Send one empty static block to give enough lookahead for inflate.
+ * This takes 10 bits, of which 7 may remain in the bit buffer.
+ */
+void ZLIB_INTERNAL _tr_align(s)
+    deflate_state *s;
+{
+    send_bits(s, STATIC_TREES<<1, 3);
+    send_code(s, END_BLOCK, static_ltree);
+#ifdef ZLIB_DEBUG
+    s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
+#endif
+    bi_flush(s);
+}
+
+/* ===========================================================================
+ * Determine the best encoding for the current block: dynamic trees, static
+ * trees or store, and write out the encoded block.
+ */
+void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)
+    deflate_state *s;
+    charf *buf;       /* input block, or NULL if too old */
+    ulg stored_len;   /* length of input block */
+    int last;         /* one if this is the last block for a file */
+{
+    ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
+    int max_blindex = 0;  /* index of last bit length code of non zero freq */
+
+    /* Build the Huffman trees unless a stored block is forced */
+    if (s->level > 0) {
+
+        /* Check if the file is binary or text */
+        if (s->strm->data_type == Z_UNKNOWN)
+            s->strm->data_type = detect_data_type(s);
+
+        /* Construct the literal and distance trees */
+        build_tree(s, (tree_desc *)(&(s->l_desc)));
+        Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
+                s->static_len));
+
+        build_tree(s, (tree_desc *)(&(s->d_desc)));
+        Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
+                s->static_len));
+        /* At this point, opt_len and static_len are the total bit lengths of
+         * the compressed block data, excluding the tree representations.
+         */
+
+        /* Build the bit length tree for the above two trees, and get the index
+         * in bl_order of the last bit length code to send.
+         */
+        max_blindex = build_bl_tree(s);
+
+        /* Determine the best encoding. Compute the block lengths in bytes. */
+        opt_lenb = (s->opt_len+3+7)>>3;
+        static_lenb = (s->static_len+3+7)>>3;
+
+        Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
+                opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
+                s->last_lit));
+
+        if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
+
+    } else {
+        Assert(buf != (char*)0, "lost buf");
+        opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
+    }
+
+#ifdef FORCE_STORED
+    if (buf != (char*)0) { /* force stored block */
+#else
+    if (stored_len+4 <= opt_lenb && buf != (char*)0) {
+                       /* 4: two words for the lengths */
+#endif
+        /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
+         * Otherwise we can't have processed more than WSIZE input bytes since
+         * the last block flush, because compression would have been
+         * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
+         * transform a block into a stored block.
+         */
+        _tr_stored_block(s, buf, stored_len, last);
+
+#ifdef FORCE_STATIC
+    } else if (static_lenb >= 0) { /* force static trees */
+#else
+    } else if (s->strategy == Z_FIXED || static_lenb == opt_lenb) {
+#endif
+        send_bits(s, (STATIC_TREES<<1)+last, 3);
+        compress_block(s, (const ct_data *)static_ltree,
+                       (const ct_data *)static_dtree);
+#ifdef ZLIB_DEBUG
+        s->compressed_len += 3 + s->static_len;
+#endif
+    } else {
+        send_bits(s, (DYN_TREES<<1)+last, 3);
+        send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
+                       max_blindex+1);
+        compress_block(s, (const ct_data *)s->dyn_ltree,
+                       (const ct_data *)s->dyn_dtree);
+#ifdef ZLIB_DEBUG
+        s->compressed_len += 3 + s->opt_len;
+#endif
+    }
+    Assert (s->compressed_len == s->bits_sent, "bad compressed size");
+    /* The above check is made mod 2^32, for files larger than 512 MB
+     * and uLong implemented on 32 bits.
+     */
+    init_block(s);
+
+    if (last) {
+        bi_windup(s);
+#ifdef ZLIB_DEBUG
+        s->compressed_len += 7;  /* align on byte boundary */
+#endif
+    }
+    Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
+           s->compressed_len-7*last));
+}
+
+/* ===========================================================================
+ * Save the match info and tally the frequency counts. Return true if
+ * the current block must be flushed.
+ */
+int ZLIB_INTERNAL _tr_tally (s, dist, lc)
+    deflate_state *s;
+    unsigned dist;  /* distance of matched string */
+    unsigned lc;    /* match length-MIN_MATCH or unmatched char (if dist==0) */
+{
+    s->d_buf[s->last_lit] = (ush)dist;
+    s->l_buf[s->last_lit++] = (uch)lc;
+    if (dist == 0) {
+        /* lc is the unmatched char */
+        s->dyn_ltree[lc].Freq++;
+    } else {
+        s->matches++;
+        /* Here, lc is the match length - MIN_MATCH */
+        dist--;             /* dist = match distance - 1 */
+        Assert((ush)dist < (ush)MAX_DIST(s) &&
+               (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
+               (ush)d_code(dist) < (ush)D_CODES,  "_tr_tally: bad match");
+
+        s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++;
+        s->dyn_dtree[d_code(dist)].Freq++;
+    }
+
+#ifdef TRUNCATE_BLOCK
+    /* Try to guess if it is profitable to stop the current block here */
+    if ((s->last_lit & 0x1fff) == 0 && s->level > 2) {
+        /* Compute an upper bound for the compressed length */
+        ulg out_length = (ulg)s->last_lit*8L;
+        ulg in_length = (ulg)((long)s->strstart - s->block_start);
+        int dcode;
+        for (dcode = 0; dcode < D_CODES; dcode++) {
+            out_length += (ulg)s->dyn_dtree[dcode].Freq *
+                (5L+extra_dbits[dcode]);
+        }
+        out_length >>= 3;
+        Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
+               s->last_lit, in_length, out_length,
+               100L - out_length*100L/in_length));
+        if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
+    }
+#endif
+    return (s->last_lit == s->lit_bufsize-1);
+    /* We avoid equality with lit_bufsize because of wraparound at 64K
+     * on 16 bit machines and because stored blocks are restricted to
+     * 64K-1 bytes.
+     */
+}
+
+/* ===========================================================================
+ * Send the block data compressed using the given Huffman trees
+ */
+local void compress_block(s, ltree, dtree)
+    deflate_state *s;
+    const ct_data *ltree; /* literal tree */
+    const ct_data *dtree; /* distance tree */
+{
+    unsigned dist;      /* distance of matched string */
+    int lc;             /* match length or unmatched char (if dist == 0) */
+    unsigned lx = 0;    /* running index in l_buf */
+    unsigned code;      /* the code to send */
+    int extra;          /* number of extra bits to send */
+
+    if (s->last_lit != 0) do {
+        dist = s->d_buf[lx];
+        lc = s->l_buf[lx++];
+        if (dist == 0) {
+            send_code(s, lc, ltree); /* send a literal byte */
+            Tracecv(isgraph(lc), (stderr," '%c' ", lc));
+        } else {
+            /* Here, lc is the match length - MIN_MATCH */
+            code = _length_code[lc];
+            send_code(s, code+LITERALS+1, ltree); /* send the length code */
+            extra = extra_lbits[code];
+            if (extra != 0) {
+                lc -= base_length[code];
+                send_bits(s, lc, extra);       /* send the extra length bits */
+            }
+            dist--; /* dist is now the match distance - 1 */
+            code = d_code(dist);
+            Assert (code < D_CODES, "bad d_code");
+
+            send_code(s, code, dtree);       /* send the distance code */
+            extra = extra_dbits[code];
+            if (extra != 0) {
+                dist -= (unsigned)base_dist[code];
+                send_bits(s, dist, extra);   /* send the extra distance bits */
+            }
+        } /* literal or match pair ? */
+
+        /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
+        Assert((uInt)(s->pending) < s->lit_bufsize + 2*lx,
+               "pendingBuf overflow");
+
+    } while (lx < s->last_lit);
+
+    send_code(s, END_BLOCK, ltree);
+}
+
+/* ===========================================================================
+ * Check if the data type is TEXT or BINARY, using the following algorithm:
+ * - TEXT if the two conditions below are satisfied:
+ *    a) There are no non-portable control characters belonging to the
+ *       "black list" (0..6, 14..25, 28..31).
+ *    b) There is at least one printable character belonging to the
+ *       "white list" (9 {TAB}, 10 {LF}, 13 {CR}, 32..255).
+ * - BINARY otherwise.
+ * - The following partially-portable control characters form a
+ *   "gray list" that is ignored in this detection algorithm:
+ *   (7 {BEL}, 8 {BS}, 11 {VT}, 12 {FF}, 26 {SUB}, 27 {ESC}).
+ * IN assertion: the fields Freq of dyn_ltree are set.
+ */
+local int detect_data_type(s)
+    deflate_state *s;
+{
+    /* black_mask is the bit mask of black-listed bytes
+     * set bits 0..6, 14..25, and 28..31
+     * 0xf3ffc07f = binary 11110011111111111100000001111111
+     */
+    unsigned long black_mask = 0xf3ffc07fUL;
+    int n;
+
+    /* Check for non-textual ("black-listed") bytes. */
+    for (n = 0; n <= 31; n++, black_mask >>= 1)
+        if ((black_mask & 1) && (s->dyn_ltree[n].Freq != 0))
+            return Z_BINARY;
+
+    /* Check for textual ("white-listed") bytes. */
+    if (s->dyn_ltree[9].Freq != 0 || s->dyn_ltree[10].Freq != 0
+            || s->dyn_ltree[13].Freq != 0)
+        return Z_TEXT;
+    for (n = 32; n < LITERALS; n++)
+        if (s->dyn_ltree[n].Freq != 0)
+            return Z_TEXT;
+
+    /* There are no "black-listed" or "white-listed" bytes:
+     * this stream either is empty or has tolerated ("gray-listed") bytes only.
+     */
+    return Z_BINARY;
+}
+
+/* ===========================================================================
+ * Reverse the first len bits of a code, using straightforward code (a faster
+ * method would use a table)
+ * IN assertion: 1 <= len <= 15
+ */
+local unsigned bi_reverse(code, len)
+    unsigned code; /* the value to invert */
+    int len;       /* its bit length */
+{
+    register unsigned res = 0;
+    do {
+        res |= code & 1;
+        code >>= 1, res <<= 1;
+    } while (--len > 0);
+    return res >> 1;
+}
+
+/* ===========================================================================
+ * Flush the bit buffer, keeping at most 7 bits in it.
+ */
+local void bi_flush(s)
+    deflate_state *s;
+{
+    if (s->bi_valid == 16) {
+        put_short(s, s->bi_buf);
+        s->bi_buf = 0;
+        s->bi_valid = 0;
+    } else if (s->bi_valid >= 8) {
+        put_byte(s, (Byte)s->bi_buf);
+        s->bi_buf >>= 8;
+        s->bi_valid -= 8;
+    }
+}
+
+/* ===========================================================================
+ * Flush the bit buffer and align the output on a byte boundary
+ */
+local void bi_windup(s)
+    deflate_state *s;
+{
+    if (s->bi_valid > 8) {
+        put_short(s, s->bi_buf);
+    } else if (s->bi_valid > 0) {
+        put_byte(s, (Byte)s->bi_buf);
+    }
+    s->bi_buf = 0;
+    s->bi_valid = 0;
+#ifdef ZLIB_DEBUG
+    s->bits_sent = (s->bits_sent+7) & ~7;
+#endif
+}

vendor/libgit2-sys/libgit2/deps/zlib/trees.h

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/trees.h b/vendor/libgit2-sys/libgit2/deps/zlib/trees.h
new file mode 100644
index 0000000..d35639d
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/trees.h
@@ -0,0 +1,128 @@
+/* header created automatically with -DGEN_TREES_H */
+
+local const ct_data static_ltree[L_CODES+2] = {
+{{ 12},{  8}}, {{140},{  8}}, {{ 76},{  8}}, {{204},{  8}}, {{ 44},{  8}},
+{{172},{  8}}, {{108},{  8}}, {{236},{  8}}, {{ 28},{  8}}, {{156},{  8}},
+{{ 92},{  8}}, {{220},{  8}}, {{ 60},{  8}}, {{188},{  8}}, {{124},{  8}},
+{{252},{  8}}, {{  2},{  8}}, {{130},{  8}}, {{ 66},{  8}}, {{194},{  8}},
+{{ 34},{  8}}, {{162},{  8}}, {{ 98},{  8}}, {{226},{  8}}, {{ 18},{  8}},
+{{146},{  8}}, {{ 82},{  8}}, {{210},{  8}}, {{ 50},{  8}}, {{178},{  8}},
+{{114},{  8}}, {{242},{  8}}, {{ 10},{  8}}, {{138},{  8}}, {{ 74},{  8}},
+{{202},{  8}}, {{ 42},{  8}}, {{170},{  8}}, {{106},{  8}}, {{234},{  8}},
+{{ 26},{  8}}, {{154},{  8}}, {{ 90},{  8}}, {{218},{  8}}, {{ 58},{  8}},
+{{186},{  8}}, {{122},{  8}}, {{250},{  8}}, {{  6},{  8}}, {{134},{  8}},
+{{ 70},{  8}}, {{198},{  8}}, {{ 38},{  8}}, {{166},{  8}}, {{102},{  8}},
+{{230},{  8}}, {{ 22},{  8}}, {{150},{  8}}, {{ 86},{  8}}, {{214},{  8}},
+{{ 54},{  8}}, {{182},{  8}}, {{118},{  8}}, {{246},{  8}}, {{ 14},{  8}},
+{{142},{  8}}, {{ 78},{  8}}, {{206},{  8}}, {{ 46},{  8}}, {{174},{  8}},
+{{110},{  8}}, {{238},{  8}}, {{ 30},{  8}}, {{158},{  8}}, {{ 94},{  8}},
+{{222},{  8}}, {{ 62},{  8}}, {{190},{  8}}, {{126},{  8}}, {{254},{  8}},
+{{  1},{  8}}, {{129},{  8}}, {{ 65},{  8}}, {{193},{  8}}, {{ 33},{  8}},
+{{161},{  8}}, {{ 97},{  8}}, {{225},{  8}}, {{ 17},{  8}}, {{145},{  8}},
+{{ 81},{  8}}, {{209},{  8}}, {{ 49},{  8}}, {{177},{  8}}, {{113},{  8}},
+{{241},{  8}}, {{  9},{  8}}, {{137},{  8}}, {{ 73},{  8}}, {{201},{  8}},
+{{ 41},{  8}}, {{169},{  8}}, {{105},{  8}}, {{233},{  8}}, {{ 25},{  8}},
+{{153},{  8}}, {{ 89},{  8}}, {{217},{  8}}, {{ 57},{  8}}, {{185},{  8}},
+{{121},{  8}}, {{249},{  8}}, {{  5},{  8}}, {{133},{  8}}, {{ 69},{  8}},
+{{197},{  8}}, {{ 37},{  8}}, {{165},{  8}}, {{101},{  8}}, {{229},{  8}},
+{{ 21},{  8}}, {{149},{  8}}, {{ 85},{  8}}, {{213},{  8}}, {{ 53},{  8}},
+{{181},{  8}}, {{117},{  8}}, {{245},{  8}}, {{ 13},{  8}}, {{141},{  8}},
+{{ 77},{  8}}, {{205},{  8}}, {{ 45},{  8}}, {{173},{  8}}, {{109},{  8}},
+{{237},{  8}}, {{ 29},{  8}}, {{157},{  8}}, {{ 93},{  8}}, {{221},{  8}},
+{{ 61},{  8}}, {{189},{  8}}, {{125},{  8}}, {{253},{  8}}, {{ 19},{  9}},
+{{275},{  9}}, {{147},{  9}}, {{403},{  9}}, {{ 83},{  9}}, {{339},{  9}},
+{{211},{  9}}, {{467},{  9}}, {{ 51},{  9}}, {{307},{  9}}, {{179},{  9}},
+{{435},{  9}}, {{115},{  9}}, {{371},{  9}}, {{243},{  9}}, {{499},{  9}},
+{{ 11},{  9}}, {{267},{  9}}, {{139},{  9}}, {{395},{  9}}, {{ 75},{  9}},
+{{331},{  9}}, {{203},{  9}}, {{459},{  9}}, {{ 43},{  9}}, {{299},{  9}},
+{{171},{  9}}, {{427},{  9}}, {{107},{  9}}, {{363},{  9}}, {{235},{  9}},
+{{491},{  9}}, {{ 27},{  9}}, {{283},{  9}}, {{155},{  9}}, {{411},{  9}},
+{{ 91},{  9}}, {{347},{  9}}, {{219},{  9}}, {{475},{  9}}, {{ 59},{  9}},
+{{315},{  9}}, {{187},{  9}}, {{443},{  9}}, {{123},{  9}}, {{379},{  9}},
+{{251},{  9}}, {{507},{  9}}, {{  7},{  9}}, {{263},{  9}}, {{135},{  9}},
+{{391},{  9}}, {{ 71},{  9}}, {{327},{  9}}, {{199},{  9}}, {{455},{  9}},
+{{ 39},{  9}}, {{295},{  9}}, {{167},{  9}}, {{423},{  9}}, {{103},{  9}},
+{{359},{  9}}, {{231},{  9}}, {{487},{  9}}, {{ 23},{  9}}, {{279},{  9}},
+{{151},{  9}}, {{407},{  9}}, {{ 87},{  9}}, {{343},{  9}}, {{215},{  9}},
+{{471},{  9}}, {{ 55},{  9}}, {{311},{  9}}, {{183},{  9}}, {{439},{  9}},
+{{119},{  9}}, {{375},{  9}}, {{247},{  9}}, {{503},{  9}}, {{ 15},{  9}},
+{{271},{  9}}, {{143},{  9}}, {{399},{  9}}, {{ 79},{  9}}, {{335},{  9}},
+{{207},{  9}}, {{463},{  9}}, {{ 47},{  9}}, {{303},{  9}}, {{175},{  9}},
+{{431},{  9}}, {{111},{  9}}, {{367},{  9}}, {{239},{  9}}, {{495},{  9}},
+{{ 31},{  9}}, {{287},{  9}}, {{159},{  9}}, {{415},{  9}}, {{ 95},{  9}},
+{{351},{  9}}, {{223},{  9}}, {{479},{  9}}, {{ 63},{  9}}, {{319},{  9}},
+{{191},{  9}}, {{447},{  9}}, {{127},{  9}}, {{383},{  9}}, {{255},{  9}},
+{{511},{  9}}, {{  0},{  7}}, {{ 64},{  7}}, {{ 32},{  7}}, {{ 96},{  7}},
+{{ 16},{  7}}, {{ 80},{  7}}, {{ 48},{  7}}, {{112},{  7}}, {{  8},{  7}},
+{{ 72},{  7}}, {{ 40},{  7}}, {{104},{  7}}, {{ 24},{  7}}, {{ 88},{  7}},
+{{ 56},{  7}}, {{120},{  7}}, {{  4},{  7}}, {{ 68},{  7}}, {{ 36},{  7}},
+{{100},{  7}}, {{ 20},{  7}}, {{ 84},{  7}}, {{ 52},{  7}}, {{116},{  7}},
+{{  3},{  8}}, {{131},{  8}}, {{ 67},{  8}}, {{195},{  8}}, {{ 35},{  8}},
+{{163},{  8}}, {{ 99},{  8}}, {{227},{  8}}
+};
+
+local const ct_data static_dtree[D_CODES] = {
+{{ 0},{ 5}}, {{16},{ 5}}, {{ 8},{ 5}}, {{24},{ 5}}, {{ 4},{ 5}},
+{{20},{ 5}}, {{12},{ 5}}, {{28},{ 5}}, {{ 2},{ 5}}, {{18},{ 5}},
+{{10},{ 5}}, {{26},{ 5}}, {{ 6},{ 5}}, {{22},{ 5}}, {{14},{ 5}},
+{{30},{ 5}}, {{ 1},{ 5}}, {{17},{ 5}}, {{ 9},{ 5}}, {{25},{ 5}},
+{{ 5},{ 5}}, {{21},{ 5}}, {{13},{ 5}}, {{29},{ 5}}, {{ 3},{ 5}},
+{{19},{ 5}}, {{11},{ 5}}, {{27},{ 5}}, {{ 7},{ 5}}, {{23},{ 5}}
+};
+
+const uch ZLIB_INTERNAL _dist_code[DIST_CODE_LEN] = {
+ 0,  1,  2,  3,  4,  4,  5,  5,  6,  6,  6,  6,  7,  7,  7,  7,  8,  8,  8,  8,
+ 8,  8,  8,  8,  9,  9,  9,  9,  9,  9,  9,  9, 10, 10, 10, 10, 10, 10, 10, 10,
+10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
+11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
+12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13,
+13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
+13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
+14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
+14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
+14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15,
+15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
+15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
+15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,  0,  0, 16, 17,
+18, 18, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22,
+23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
+24, 24, 24, 24, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
+26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
+26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27,
+27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
+27, 27, 27, 27, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
+28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
+28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
+28, 28, 28, 28, 28, 28, 28, 28, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
+29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
+29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
+29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29
+};
+
+const uch ZLIB_INTERNAL _length_code[MAX_MATCH-MIN_MATCH+1]= {
+ 0,  1,  2,  3,  4,  5,  6,  7,  8,  8,  9,  9, 10, 10, 11, 11, 12, 12, 12, 12,
+13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16,
+17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19,
+19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,
+21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22,
+22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23,
+23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
+24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
+25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
+25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 26, 26, 26, 26, 26, 26, 26, 26,
+26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
+26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
+27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 28
+};
+
+local const int base_length[LENGTH_CODES] = {
+0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 20, 24, 28, 32, 40, 48, 56,
+64, 80, 96, 112, 128, 160, 192, 224, 0
+};
+
+local const int base_dist[D_CODES] = {
+    0,     1,     2,     3,     4,     6,     8,    12,    16,    24,
+   32,    48,    64,    96,   128,   192,   256,   384,   512,   768,
+ 1024,  1536,  2048,  3072,  4096,  6144,  8192, 12288, 16384, 24576
+};
+

vendor/libgit2-sys/libgit2/deps/zlib/zconf.h

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/zconf.h b/vendor/libgit2-sys/libgit2/deps/zlib/zconf.h
new file mode 100644
index 0000000..5e1d68a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/zconf.h
@@ -0,0 +1,534 @@
+/* zconf.h -- configuration of the zlib compression library
+ * Copyright (C) 1995-2016 Jean-loup Gailly, Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* @(#) $Id$ */
+
+#ifndef ZCONF_H
+#define ZCONF_H
+
+/*
+ * If you *really* need a unique prefix for all types and library functions,
+ * compile with -DZ_PREFIX. The "standard" zlib should be compiled without it.
+ * Even better than compiling with -DZ_PREFIX would be to use configure to set
+ * this permanently in zconf.h using "./configure --zprefix".
+ */
+#ifdef Z_PREFIX     /* may be set to #if 1 by ./configure */
+#  define Z_PREFIX_SET
+
+/* all linked symbols and init macros */
+#  define _dist_code            z__dist_code
+#  define _length_code          z__length_code
+#  define _tr_align             z__tr_align
+#  define _tr_flush_bits        z__tr_flush_bits
+#  define _tr_flush_block       z__tr_flush_block
+#  define _tr_init              z__tr_init
+#  define _tr_stored_block      z__tr_stored_block
+#  define _tr_tally             z__tr_tally
+#  define adler32               z_adler32
+#  define adler32_combine       z_adler32_combine
+#  define adler32_combine64     z_adler32_combine64
+#  define adler32_z             z_adler32_z
+#  ifndef Z_SOLO
+#    define compress              z_compress
+#    define compress2             z_compress2
+#    define compressBound         z_compressBound
+#  endif
+#  define crc32                 z_crc32
+#  define crc32_combine         z_crc32_combine
+#  define crc32_combine64       z_crc32_combine64
+#  define crc32_z               z_crc32_z
+#  define deflate               z_deflate
+#  define deflateBound          z_deflateBound
+#  define deflateCopy           z_deflateCopy
+#  define deflateEnd            z_deflateEnd
+#  define deflateGetDictionary  z_deflateGetDictionary
+#  define deflateInit           z_deflateInit
+#  define deflateInit2          z_deflateInit2
+#  define deflateInit2_         z_deflateInit2_
+#  define deflateInit_          z_deflateInit_
+#  define deflateParams         z_deflateParams
+#  define deflatePending        z_deflatePending
+#  define deflatePrime          z_deflatePrime
+#  define deflateReset          z_deflateReset
+#  define deflateResetKeep      z_deflateResetKeep
+#  define deflateSetDictionary  z_deflateSetDictionary
+#  define deflateSetHeader      z_deflateSetHeader
+#  define deflateTune           z_deflateTune
+#  define deflate_copyright     z_deflate_copyright
+#  define get_crc_table         z_get_crc_table
+#  ifndef Z_SOLO
+#    define gz_error              z_gz_error
+#    define gz_intmax             z_gz_intmax
+#    define gz_strwinerror        z_gz_strwinerror
+#    define gzbuffer              z_gzbuffer
+#    define gzclearerr            z_gzclearerr
+#    define gzclose               z_gzclose
+#    define gzclose_r             z_gzclose_r
+#    define gzclose_w             z_gzclose_w
+#    define gzdirect              z_gzdirect
+#    define gzdopen               z_gzdopen
+#    define gzeof                 z_gzeof
+#    define gzerror               z_gzerror
+#    define gzflush               z_gzflush
+#    define gzfread               z_gzfread
+#    define gzfwrite              z_gzfwrite
+#    define gzgetc                z_gzgetc
+#    define gzgetc_               z_gzgetc_
+#    define gzgets                z_gzgets
+#    define gzoffset              z_gzoffset
+#    define gzoffset64            z_gzoffset64
+#    define gzopen                z_gzopen
+#    define gzopen64              z_gzopen64
+#    ifdef _WIN32
+#      define gzopen_w              z_gzopen_w
+#    endif
+#    define gzprintf              z_gzprintf
+#    define gzputc                z_gzputc
+#    define gzputs                z_gzputs
+#    define gzread                z_gzread
+#    define gzrewind              z_gzrewind
+#    define gzseek                z_gzseek
+#    define gzseek64              z_gzseek64
+#    define gzsetparams           z_gzsetparams
+#    define gztell                z_gztell
+#    define gztell64              z_gztell64
+#    define gzungetc              z_gzungetc
+#    define gzvprintf             z_gzvprintf
+#    define gzwrite               z_gzwrite
+#  endif
+#  define inflate               z_inflate
+#  define inflateBack           z_inflateBack
+#  define inflateBackEnd        z_inflateBackEnd
+#  define inflateBackInit       z_inflateBackInit
+#  define inflateBackInit_      z_inflateBackInit_
+#  define inflateCodesUsed      z_inflateCodesUsed
+#  define inflateCopy           z_inflateCopy
+#  define inflateEnd            z_inflateEnd
+#  define inflateGetDictionary  z_inflateGetDictionary
+#  define inflateGetHeader      z_inflateGetHeader
+#  define inflateInit           z_inflateInit
+#  define inflateInit2          z_inflateInit2
+#  define inflateInit2_         z_inflateInit2_
+#  define inflateInit_          z_inflateInit_
+#  define inflateMark           z_inflateMark
+#  define inflatePrime          z_inflatePrime
+#  define inflateReset          z_inflateReset
+#  define inflateReset2         z_inflateReset2
+#  define inflateResetKeep      z_inflateResetKeep
+#  define inflateSetDictionary  z_inflateSetDictionary
+#  define inflateSync           z_inflateSync
+#  define inflateSyncPoint      z_inflateSyncPoint
+#  define inflateUndermine      z_inflateUndermine
+#  define inflateValidate       z_inflateValidate
+#  define inflate_copyright     z_inflate_copyright
+#  define inflate_fast          z_inflate_fast
+#  define inflate_table         z_inflate_table
+#  ifndef Z_SOLO
+#    define uncompress            z_uncompress
+#    define uncompress2           z_uncompress2
+#  endif
+#  define zError                z_zError
+#  ifndef Z_SOLO
+#    define zcalloc               z_zcalloc
+#    define zcfree                z_zcfree
+#  endif
+#  define zlibCompileFlags      z_zlibCompileFlags
+#  define zlibVersion           z_zlibVersion
+
+/* all zlib typedefs in zlib.h and zconf.h */
+#  define Byte                  z_Byte
+#  define Bytef                 z_Bytef
+#  define alloc_func            z_alloc_func
+#  define charf                 z_charf
+#  define free_func             z_free_func
+#  ifndef Z_SOLO
+#    define gzFile                z_gzFile
+#  endif
+#  define gz_header             z_gz_header
+#  define gz_headerp            z_gz_headerp
+#  define in_func               z_in_func
+#  define intf                  z_intf
+#  define out_func              z_out_func
+#  define uInt                  z_uInt
+#  define uIntf                 z_uIntf
+#  define uLong                 z_uLong
+#  define uLongf                z_uLongf
+#  define voidp                 z_voidp
+#  define voidpc                z_voidpc
+#  define voidpf                z_voidpf
+
+/* all zlib structs in zlib.h and zconf.h */
+#  define gz_header_s           z_gz_header_s
+#  define internal_state        z_internal_state
+
+#endif
+
+#if defined(__MSDOS__) && !defined(MSDOS)
+#  define MSDOS
+#endif
+#if (defined(OS_2) || defined(__OS2__)) && !defined(OS2)
+#  define OS2
+#endif
+#if defined(_WINDOWS) && !defined(WINDOWS)
+#  define WINDOWS
+#endif
+#if defined(_WIN32) || defined(_WIN32_WCE) || defined(__WIN32__)
+#  ifndef WIN32
+#    define WIN32
+#  endif
+#endif
+#if (defined(MSDOS) || defined(OS2) || defined(WINDOWS)) && !defined(WIN32)
+#  if !defined(__GNUC__) && !defined(__FLAT__) && !defined(__386__)
+#    ifndef SYS16BIT
+#      define SYS16BIT
+#    endif
+#  endif
+#endif
+
+/*
+ * Compile with -DMAXSEG_64K if the alloc function cannot allocate more
+ * than 64k bytes at a time (needed on systems with 16-bit int).
+ */
+#ifdef SYS16BIT
+#  define MAXSEG_64K
+#endif
+#ifdef MSDOS
+#  define UNALIGNED_OK
+#endif
+
+#ifdef __STDC_VERSION__
+#  ifndef STDC
+#    define STDC
+#  endif
+#  if __STDC_VERSION__ >= 199901L
+#    ifndef STDC99
+#      define STDC99
+#    endif
+#  endif
+#endif
+#if !defined(STDC) && (defined(__STDC__) || defined(__cplusplus))
+#  define STDC
+#endif
+#if !defined(STDC) && (defined(__GNUC__) || defined(__BORLANDC__))
+#  define STDC
+#endif
+#if !defined(STDC) && (defined(MSDOS) || defined(WINDOWS) || defined(WIN32))
+#  define STDC
+#endif
+#if !defined(STDC) && (defined(OS2) || defined(__HOS_AIX__))
+#  define STDC
+#endif
+
+#if defined(__OS400__) && !defined(STDC)    /* iSeries (formerly AS/400). */
+#  define STDC
+#endif
+
+#ifndef STDC
+#  ifndef const /* cannot use !defined(STDC) && !defined(const) on Mac */
+#    define const       /* note: need a more gentle solution here */
+#  endif
+#endif
+
+#if defined(ZLIB_CONST) && !defined(z_const)
+#  define z_const const
+#else
+#  define z_const
+#endif
+
+#ifdef Z_SOLO
+   typedef unsigned long z_size_t;
+#else
+#  define z_longlong long long
+#  if defined(NO_SIZE_T)
+     typedef unsigned NO_SIZE_T z_size_t;
+#  elif defined(STDC)
+#    include <stddef.h>
+     typedef size_t z_size_t;
+#  else
+     typedef unsigned long z_size_t;
+#  endif
+#  undef z_longlong
+#endif
+
+/* Maximum value for memLevel in deflateInit2 */
+#ifndef MAX_MEM_LEVEL
+#  ifdef MAXSEG_64K
+#    define MAX_MEM_LEVEL 8
+#  else
+#    define MAX_MEM_LEVEL 9
+#  endif
+#endif
+
+/* Maximum value for windowBits in deflateInit2 and inflateInit2.
+ * WARNING: reducing MAX_WBITS makes minigzip unable to extract .gz files
+ * created by gzip. (Files created by minigzip can still be extracted by
+ * gzip.)
+ */
+#ifndef MAX_WBITS
+#  define MAX_WBITS   15 /* 32K LZ77 window */
+#endif
+
+/* The memory requirements for deflate are (in bytes):
+            (1 << (windowBits+2)) +  (1 << (memLevel+9))
+ that is: 128K for windowBits=15  +  128K for memLevel = 8  (default values)
+ plus a few kilobytes for small objects. For example, if you want to reduce
+ the default memory requirements from 256K to 128K, compile with
+     make CFLAGS="-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7"
+ Of course this will generally degrade compression (there's no free lunch).
+
+   The memory requirements for inflate are (in bytes) 1 << windowBits
+ that is, 32K for windowBits=15 (default value) plus about 7 kilobytes
+ for small objects.
+*/
+
+                        /* Type declarations */
+
+#ifndef OF /* function prototypes */
+#  ifdef STDC
+#    define OF(args)  args
+#  else
+#    define OF(args)  ()
+#  endif
+#endif
+
+#ifndef Z_ARG /* function prototypes for stdarg */
+#  if defined(STDC) || defined(Z_HAVE_STDARG_H)
+#    define Z_ARG(args)  args
+#  else
+#    define Z_ARG(args)  ()
+#  endif
+#endif
+
+/* The following definitions for FAR are needed only for MSDOS mixed
+ * model programming (small or medium model with some far allocations).
+ * This was tested only with MSC; for other MSDOS compilers you may have
+ * to define NO_MEMCPY in zutil.h.  If you don't need the mixed model,
+ * just define FAR to be empty.
+ */
+#ifdef SYS16BIT
+#  if defined(M_I86SM) || defined(M_I86MM)
+     /* MSC small or medium model */
+#    define SMALL_MEDIUM
+#    ifdef _MSC_VER
+#      define FAR _far
+#    else
+#      define FAR far
+#    endif
+#  endif
+#  if (defined(__SMALL__) || defined(__MEDIUM__))
+     /* Turbo C small or medium model */
+#    define SMALL_MEDIUM
+#    ifdef __BORLANDC__
+#      define FAR _far
+#    else
+#      define FAR far
+#    endif
+#  endif
+#endif
+
+#if defined(WINDOWS) || defined(WIN32)
+   /* If building or using zlib as a DLL, define ZLIB_DLL.
+    * This is not mandatory, but it offers a little performance increase.
+    */
+#  ifdef ZLIB_DLL
+#    if defined(WIN32) && (!defined(__BORLANDC__) || (__BORLANDC__ >= 0x500))
+#      ifdef ZLIB_INTERNAL
+#        define ZEXTERN extern __declspec(dllexport)
+#      else
+#        define ZEXTERN extern __declspec(dllimport)
+#      endif
+#    endif
+#  endif  /* ZLIB_DLL */
+   /* If building or using zlib with the WINAPI/WINAPIV calling convention,
+    * define ZLIB_WINAPI.
+    * Caution: the standard ZLIB1.DLL is NOT compiled using ZLIB_WINAPI.
+    */
+#  ifdef ZLIB_WINAPI
+#    ifdef FAR
+#      undef FAR
+#    endif
+#    include <windows.h>
+     /* No need for _export, use ZLIB.DEF instead. */
+     /* For complete Windows compatibility, use WINAPI, not __stdcall. */
+#    define ZEXPORT WINAPI
+#    ifdef WIN32
+#      define ZEXPORTVA WINAPIV
+#    else
+#      define ZEXPORTVA FAR CDECL
+#    endif
+#  endif
+#endif
+
+#if defined (__BEOS__)
+#  ifdef ZLIB_DLL
+#    ifdef ZLIB_INTERNAL
+#      define ZEXPORT   __declspec(dllexport)
+#      define ZEXPORTVA __declspec(dllexport)
+#    else
+#      define ZEXPORT   __declspec(dllimport)
+#      define ZEXPORTVA __declspec(dllimport)
+#    endif
+#  endif
+#endif
+
+#ifndef ZEXTERN
+#  define ZEXTERN extern
+#endif
+#ifndef ZEXPORT
+#  define ZEXPORT
+#endif
+#ifndef ZEXPORTVA
+#  define ZEXPORTVA
+#endif
+
+#ifndef FAR
+#  define FAR
+#endif
+
+#if !defined(__MACTYPES__)
+typedef unsigned char  Byte;  /* 8 bits */
+#endif
+typedef unsigned int   uInt;  /* 16 bits or more */
+typedef unsigned long  uLong; /* 32 bits or more */
+
+#ifdef SMALL_MEDIUM
+   /* Borland C/C++ and some old MSC versions ignore FAR inside typedef */
+#  define Bytef Byte FAR
+#else
+   typedef Byte  FAR Bytef;
+#endif
+typedef char  FAR charf;
+typedef int   FAR intf;
+typedef uInt  FAR uIntf;
+typedef uLong FAR uLongf;
+
+#ifdef STDC
+   typedef void const *voidpc;
+   typedef void FAR   *voidpf;
+   typedef void       *voidp;
+#else
+   typedef Byte const *voidpc;
+   typedef Byte FAR   *voidpf;
+   typedef Byte       *voidp;
+#endif
+
+#if !defined(Z_U4) && !defined(Z_SOLO) && defined(STDC)
+#  include <limits.h>
+#  if (UINT_MAX == 0xffffffffUL)
+#    define Z_U4 unsigned
+#  elif (ULONG_MAX == 0xffffffffUL)
+#    define Z_U4 unsigned long
+#  elif (USHRT_MAX == 0xffffffffUL)
+#    define Z_U4 unsigned short
+#  endif
+#endif
+
+#ifdef Z_U4
+   typedef Z_U4 z_crc_t;
+#else
+   typedef unsigned long z_crc_t;
+#endif
+
+#ifdef HAVE_UNISTD_H    /* may be set to #if 1 by ./configure */
+#  define Z_HAVE_UNISTD_H
+#endif
+
+#ifdef HAVE_STDARG_H    /* may be set to #if 1 by ./configure */
+#  define Z_HAVE_STDARG_H
+#endif
+
+#ifdef STDC
+#  ifndef Z_SOLO
+#    include <sys/types.h>      /* for off_t */
+#  endif
+#endif
+
+#if defined(STDC) || defined(Z_HAVE_STDARG_H)
+#  ifndef Z_SOLO
+#    include <stdarg.h>         /* for va_list */
+#  endif
+#endif
+
+#ifdef _WIN32
+#  ifndef Z_SOLO
+#    include <stddef.h>         /* for wchar_t */
+#  endif
+#endif
+
+/* a little trick to accommodate both "#define _LARGEFILE64_SOURCE" and
+ * "#define _LARGEFILE64_SOURCE 1" as requesting 64-bit operations, (even
+ * though the former does not conform to the LFS document), but considering
+ * both "#undef _LARGEFILE64_SOURCE" and "#define _LARGEFILE64_SOURCE 0" as
+ * equivalently requesting no 64-bit operations
+ */
+#if defined(_LARGEFILE64_SOURCE) && -_LARGEFILE64_SOURCE - -1 == 1
+#  undef _LARGEFILE64_SOURCE
+#endif
+
+#if defined(__WATCOMC__) && !defined(Z_HAVE_UNISTD_H)
+#  define Z_HAVE_UNISTD_H
+#endif
+#ifndef Z_SOLO
+#  if defined(Z_HAVE_UNISTD_H) || defined(_LARGEFILE64_SOURCE)
+#    include <unistd.h>         /* for SEEK_*, off_t, and _LFS64_LARGEFILE */
+#    ifdef VMS
+#      include <unixio.h>       /* for off_t */
+#    endif
+#    ifndef z_off_t
+#      define z_off_t off_t
+#    endif
+#  endif
+#endif
+
+#if defined(_LFS64_LARGEFILE) && _LFS64_LARGEFILE-0
+#  define Z_LFS64
+#endif
+
+#if defined(_LARGEFILE64_SOURCE) && defined(Z_LFS64)
+#  define Z_LARGE64
+#endif
+
+#if defined(_FILE_OFFSET_BITS) && _FILE_OFFSET_BITS-0 == 64 && defined(Z_LFS64)
+#  define Z_WANT64
+#endif
+
+#if !defined(SEEK_SET) && !defined(Z_SOLO)
+#  define SEEK_SET        0       /* Seek from beginning of file.  */
+#  define SEEK_CUR        1       /* Seek from current position.  */
+#  define SEEK_END        2       /* Set file pointer to EOF plus "offset" */
+#endif
+
+#ifndef z_off_t
+#  define z_off_t long
+#endif
+
+#if !defined(_WIN32) && defined(Z_LARGE64)
+#  define z_off64_t off64_t
+#else
+#  if defined(_WIN32) && !defined(__GNUC__) && !defined(Z_SOLO)
+#    define z_off64_t __int64
+#  else
+#    define z_off64_t z_off_t
+#  endif
+#endif
+
+/* MVS linker does not support external names larger than 8 bytes */
+#if defined(__MVS__)
+  #pragma map(deflateInit_,"DEIN")
+  #pragma map(deflateInit2_,"DEIN2")
+  #pragma map(deflateEnd,"DEEND")
+  #pragma map(deflateBound,"DEBND")
+  #pragma map(inflateInit_,"ININ")
+  #pragma map(inflateInit2_,"ININ2")
+  #pragma map(inflateEnd,"INEND")
+  #pragma map(inflateSync,"INSY")
+  #pragma map(inflateSetDictionary,"INSEDI")
+  #pragma map(compressBound,"CMBND")
+  #pragma map(inflate_table,"INTABL")
+  #pragma map(inflate_fast,"INFA")
+  #pragma map(inflate_copyright,"INCOPY")
+#endif
+
+#endif /* ZCONF_H */

vendor/libgit2-sys/libgit2/deps/zlib/zlib.h

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/zlib.h b/vendor/libgit2-sys/libgit2/deps/zlib/zlib.h
new file mode 100644
index 0000000..f09cdaf
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/zlib.h
@@ -0,0 +1,1912 @@
+/* zlib.h -- interface of the 'zlib' general purpose compression library
+  version 1.2.11, January 15th, 2017
+
+  Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  Jean-loup Gailly        Mark Adler
+  jloup@gzip.org          madler@alumni.caltech.edu
+
+
+  The data format used by the zlib library is described by RFCs (Request for
+  Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
+  (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
+*/
+
+#ifndef ZLIB_H
+#define ZLIB_H
+
+#include "zconf.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define ZLIB_VERSION "1.2.11"
+#define ZLIB_VERNUM 0x12b0
+#define ZLIB_VER_MAJOR 1
+#define ZLIB_VER_MINOR 2
+#define ZLIB_VER_REVISION 11
+#define ZLIB_VER_SUBREVISION 0
+
+/*
+    The 'zlib' compression library provides in-memory compression and
+  decompression functions, including integrity checks of the uncompressed data.
+  This version of the library supports only one compression method (deflation)
+  but other algorithms will be added later and will have the same stream
+  interface.
+
+    Compression can be done in a single step if the buffers are large enough,
+  or can be done by repeated calls of the compression function.  In the latter
+  case, the application must provide more input and/or consume the output
+  (providing more output space) before each call.
+
+    The compressed data format used by default by the in-memory functions is
+  the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
+  around a deflate stream, which is itself documented in RFC 1951.
+
+    The library also supports reading and writing files in gzip (.gz) format
+  with an interface similar to that of stdio using the functions that start
+  with "gz".  The gzip format is different from the zlib format.  gzip is a
+  gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
+
+    This library can optionally read and write gzip and raw deflate streams in
+  memory as well.
+
+    The zlib format was designed to be compact and fast for use in memory
+  and on communications channels.  The gzip format was designed for single-
+  file compression on file systems, has a larger header than zlib to maintain
+  directory information, and uses a different, slower check method than zlib.
+
+    The library does not install any signal handler.  The decoder checks
+  the consistency of the compressed data, so the library should never crash
+  even in the case of corrupted input.
+*/
+
+typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
+typedef void   (*free_func)  OF((voidpf opaque, voidpf address));
+
+struct internal_state;
+
+typedef struct z_stream_s {
+    z_const Bytef *next_in;     /* next input byte */
+    uInt     avail_in;  /* number of bytes available at next_in */
+    uLong    total_in;  /* total number of input bytes read so far */
+
+    Bytef    *next_out; /* next output byte will go here */
+    uInt     avail_out; /* remaining free space at next_out */
+    uLong    total_out; /* total number of bytes output so far */
+
+    z_const char *msg;  /* last error message, NULL if no error */
+    struct internal_state FAR *state; /* not visible by applications */
+
+    alloc_func zalloc;  /* used to allocate the internal state */
+    free_func  zfree;   /* used to free the internal state */
+    voidpf     opaque;  /* private data object passed to zalloc and zfree */
+
+    int     data_type;  /* best guess about the data type: binary or text
+                           for deflate, or the decoding state for inflate */
+    uLong   adler;      /* Adler-32 or CRC-32 value of the uncompressed data */
+    uLong   reserved;   /* reserved for future use */
+} z_stream;
+
+typedef z_stream FAR *z_streamp;
+
+/*
+     gzip header information passed to and from zlib routines.  See RFC 1952
+  for more details on the meanings of these fields.
+*/
+typedef struct gz_header_s {
+    int     text;       /* true if compressed data believed to be text */
+    uLong   time;       /* modification time */
+    int     xflags;     /* extra flags (not used when writing a gzip file) */
+    int     os;         /* operating system */
+    Bytef   *extra;     /* pointer to extra field or Z_NULL if none */
+    uInt    extra_len;  /* extra field length (valid if extra != Z_NULL) */
+    uInt    extra_max;  /* space at extra (only when reading header) */
+    Bytef   *name;      /* pointer to zero-terminated file name or Z_NULL */
+    uInt    name_max;   /* space at name (only when reading header) */
+    Bytef   *comment;   /* pointer to zero-terminated comment or Z_NULL */
+    uInt    comm_max;   /* space at comment (only when reading header) */
+    int     hcrc;       /* true if there was or will be a header crc */
+    int     done;       /* true when done reading gzip header (not used
+                           when writing a gzip file) */
+} gz_header;
+
+typedef gz_header FAR *gz_headerp;
+
+/*
+     The application must update next_in and avail_in when avail_in has dropped
+   to zero.  It must update next_out and avail_out when avail_out has dropped
+   to zero.  The application must initialize zalloc, zfree and opaque before
+   calling the init function.  All other fields are set by the compression
+   library and must not be updated by the application.
+
+     The opaque value provided by the application will be passed as the first
+   parameter for calls of zalloc and zfree.  This can be useful for custom
+   memory management.  The compression library attaches no meaning to the
+   opaque value.
+
+     zalloc must return Z_NULL if there is not enough memory for the object.
+   If zlib is used in a multi-threaded application, zalloc and zfree must be
+   thread safe.  In that case, zlib is thread-safe.  When zalloc and zfree are
+   Z_NULL on entry to the initialization function, they are set to internal
+   routines that use the standard library functions malloc() and free().
+
+     On 16-bit systems, the functions zalloc and zfree must be able to allocate
+   exactly 65536 bytes, but will not be required to allocate more than this if
+   the symbol MAXSEG_64K is defined (see zconf.h).  WARNING: On MSDOS, pointers
+   returned by zalloc for objects of exactly 65536 bytes *must* have their
+   offset normalized to zero.  The default allocation function provided by this
+   library ensures this (see zutil.c).  To reduce memory requirements and avoid
+   any allocation of 64K objects, at the expense of compression ratio, compile
+   the library with -DMAX_WBITS=14 (see zconf.h).
+
+     The fields total_in and total_out can be used for statistics or progress
+   reports.  After compression, total_in holds the total size of the
+   uncompressed data and may be saved for use by the decompressor (particularly
+   if the decompressor wants to decompress everything in a single step).
+*/
+
+                        /* constants */
+
+#define Z_NO_FLUSH      0
+#define Z_PARTIAL_FLUSH 1
+#define Z_SYNC_FLUSH    2
+#define Z_FULL_FLUSH    3
+#define Z_FINISH        4
+#define Z_BLOCK         5
+#define Z_TREES         6
+/* Allowed flush values; see deflate() and inflate() below for details */
+
+#define Z_OK            0
+#define Z_STREAM_END    1
+#define Z_NEED_DICT     2
+#define Z_ERRNO        (-1)
+#define Z_STREAM_ERROR (-2)
+#define Z_DATA_ERROR   (-3)
+#define Z_MEM_ERROR    (-4)
+#define Z_BUF_ERROR    (-5)
+#define Z_VERSION_ERROR (-6)
+/* Return codes for the compression/decompression functions. Negative values
+ * are errors, positive values are used for special but normal events.
+ */
+
+#define Z_NO_COMPRESSION         0
+#define Z_BEST_SPEED             1
+#define Z_BEST_COMPRESSION       9
+#define Z_DEFAULT_COMPRESSION  (-1)
+/* compression levels */
+
+#define Z_FILTERED            1
+#define Z_HUFFMAN_ONLY        2
+#define Z_RLE                 3
+#define Z_FIXED               4
+#define Z_DEFAULT_STRATEGY    0
+/* compression strategy; see deflateInit2() below for details */
+
+#define Z_BINARY   0
+#define Z_TEXT     1
+#define Z_ASCII    Z_TEXT   /* for compatibility with 1.2.2 and earlier */
+#define Z_UNKNOWN  2
+/* Possible values of the data_type field for deflate() */
+
+#define Z_DEFLATED   8
+/* The deflate compression method (the only one supported in this version) */
+
+#define Z_NULL  0  /* for initializing zalloc, zfree, opaque */
+
+#define zlib_version zlibVersion()
+/* for compatibility with versions < 1.0.2 */
+
+
+                        /* basic functions */
+
+ZEXTERN const char * ZEXPORT zlibVersion OF((void));
+/* The application can compare zlibVersion and ZLIB_VERSION for consistency.
+   If the first character differs, the library code actually used is not
+   compatible with the zlib.h header file used by the application.  This check
+   is automatically made by deflateInit and inflateInit.
+ */
+
+/*
+ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
+
+     Initializes the internal stream state for compression.  The fields
+   zalloc, zfree and opaque must be initialized before by the caller.  If
+   zalloc and zfree are set to Z_NULL, deflateInit updates them to use default
+   allocation functions.
+
+     The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
+   1 gives best speed, 9 gives best compression, 0 gives no compression at all
+   (the input data is simply copied a block at a time).  Z_DEFAULT_COMPRESSION
+   requests a default compromise between speed and compression (currently
+   equivalent to level 6).
+
+     deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_STREAM_ERROR if level is not a valid compression level, or
+   Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
+   with the version assumed by the caller (ZLIB_VERSION).  msg is set to null
+   if there is no error message.  deflateInit does not perform any compression:
+   this will be done by deflate().
+*/
+
+
+ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
+/*
+    deflate compresses as much data as possible, and stops when the input
+  buffer becomes empty or the output buffer becomes full.  It may introduce
+  some output latency (reading input without producing any output) except when
+  forced to flush.
+
+    The detailed semantics are as follows.  deflate performs one or both of the
+  following actions:
+
+  - Compress more input starting at next_in and update next_in and avail_in
+    accordingly.  If not all input can be processed (because there is not
+    enough room in the output buffer), next_in and avail_in are updated and
+    processing will resume at this point for the next call of deflate().
+
+  - Generate more output starting at next_out and update next_out and avail_out
+    accordingly.  This action is forced if the parameter flush is non zero.
+    Forcing flush frequently degrades the compression ratio, so this parameter
+    should be set only when necessary.  Some output may be provided even if
+    flush is zero.
+
+    Before the call of deflate(), the application should ensure that at least
+  one of the actions is possible, by providing more input and/or consuming more
+  output, and updating avail_in or avail_out accordingly; avail_out should
+  never be zero before the call.  The application can consume the compressed
+  output when it wants, for example when the output buffer is full (avail_out
+  == 0), or after each call of deflate().  If deflate returns Z_OK and with
+  zero avail_out, it must be called again after making room in the output
+  buffer because there might be more output pending. See deflatePending(),
+  which can be used if desired to determine whether or not there is more ouput
+  in that case.
+
+    Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
+  decide how much data to accumulate before producing output, in order to
+  maximize compression.
+
+    If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
+  flushed to the output buffer and the output is aligned on a byte boundary, so
+  that the decompressor can get all input data available so far.  (In
+  particular avail_in is zero after the call if enough output space has been
+  provided before the call.) Flushing may degrade compression for some
+  compression algorithms and so it should be used only when necessary.  This
+  completes the current deflate block and follows it with an empty stored block
+  that is three bits plus filler bits to the next byte, followed by four bytes
+  (00 00 ff ff).
+
+    If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
+  output buffer, but the output is not aligned to a byte boundary.  All of the
+  input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
+  This completes the current deflate block and follows it with an empty fixed
+  codes block that is 10 bits long.  This assures that enough bytes are output
+  in order for the decompressor to finish the block before the empty fixed
+  codes block.
+
+    If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
+  for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
+  seven bits of the current block are held to be written as the next byte after
+  the next deflate block is completed.  In this case, the decompressor may not
+  be provided enough bits at this point in order to complete decompression of
+  the data provided so far to the compressor.  It may need to wait for the next
+  block to be emitted.  This is for advanced applications that need to control
+  the emission of deflate blocks.
+
+    If flush is set to Z_FULL_FLUSH, all output is flushed as with
+  Z_SYNC_FLUSH, and the compression state is reset so that decompression can
+  restart from this point if previous compressed data has been damaged or if
+  random access is desired.  Using Z_FULL_FLUSH too often can seriously degrade
+  compression.
+
+    If deflate returns with avail_out == 0, this function must be called again
+  with the same value of the flush parameter and more output space (updated
+  avail_out), until the flush is complete (deflate returns with non-zero
+  avail_out).  In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
+  avail_out is greater than six to avoid repeated flush markers due to
+  avail_out == 0 on return.
+
+    If the parameter flush is set to Z_FINISH, pending input is processed,
+  pending output is flushed and deflate returns with Z_STREAM_END if there was
+  enough output space.  If deflate returns with Z_OK or Z_BUF_ERROR, this
+  function must be called again with Z_FINISH and more output space (updated
+  avail_out) but no more input data, until it returns with Z_STREAM_END or an
+  error.  After deflate has returned Z_STREAM_END, the only possible operations
+  on the stream are deflateReset or deflateEnd.
+
+    Z_FINISH can be used in the first deflate call after deflateInit if all the
+  compression is to be done in a single step.  In order to complete in one
+  call, avail_out must be at least the value returned by deflateBound (see
+  below).  Then deflate is guaranteed to return Z_STREAM_END.  If not enough
+  output space is provided, deflate will not return Z_STREAM_END, and it must
+  be called again as described above.
+
+    deflate() sets strm->adler to the Adler-32 checksum of all input read
+  so far (that is, total_in bytes).  If a gzip stream is being generated, then
+  strm->adler will be the CRC-32 checksum of the input read so far.  (See
+  deflateInit2 below.)
+
+    deflate() may update strm->data_type if it can make a good guess about
+  the input data type (Z_BINARY or Z_TEXT).  If in doubt, the data is
+  considered binary.  This field is only for information purposes and does not
+  affect the compression algorithm in any manner.
+
+    deflate() returns Z_OK if some progress has been made (more input
+  processed or more output produced), Z_STREAM_END if all input has been
+  consumed and all output has been produced (only when flush is set to
+  Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
+  if next_in or next_out was Z_NULL or the state was inadvertently written over
+  by the application), or Z_BUF_ERROR if no progress is possible (for example
+  avail_in or avail_out was zero).  Note that Z_BUF_ERROR is not fatal, and
+  deflate() can be called again with more input and more output space to
+  continue compressing.
+*/
+
+
+ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
+/*
+     All dynamically allocated data structures for this stream are freed.
+   This function discards any unprocessed input and does not flush any pending
+   output.
+
+     deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
+   stream state was inconsistent, Z_DATA_ERROR if the stream was freed
+   prematurely (some input or output was discarded).  In the error case, msg
+   may be set but then points to a static string (which must not be
+   deallocated).
+*/
+
+
+/*
+ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
+
+     Initializes the internal stream state for decompression.  The fields
+   next_in, avail_in, zalloc, zfree and opaque must be initialized before by
+   the caller.  In the current version of inflate, the provided input is not
+   read or consumed.  The allocation of a sliding window will be deferred to
+   the first call of inflate (if the decompression does not complete on the
+   first call).  If zalloc and zfree are set to Z_NULL, inflateInit updates
+   them to use default allocation functions.
+
+     inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
+   version assumed by the caller, or Z_STREAM_ERROR if the parameters are
+   invalid, such as a null pointer to the structure.  msg is set to null if
+   there is no error message.  inflateInit does not perform any decompression.
+   Actual decompression will be done by inflate().  So next_in, and avail_in,
+   next_out, and avail_out are unused and unchanged.  The current
+   implementation of inflateInit() does not process any header information --
+   that is deferred until inflate() is called.
+*/
+
+
+ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
+/*
+    inflate decompresses as much data as possible, and stops when the input
+  buffer becomes empty or the output buffer becomes full.  It may introduce
+  some output latency (reading input without producing any output) except when
+  forced to flush.
+
+  The detailed semantics are as follows.  inflate performs one or both of the
+  following actions:
+
+  - Decompress more input starting at next_in and update next_in and avail_in
+    accordingly.  If not all input can be processed (because there is not
+    enough room in the output buffer), then next_in and avail_in are updated
+    accordingly, and processing will resume at this point for the next call of
+    inflate().
+
+  - Generate more output starting at next_out and update next_out and avail_out
+    accordingly.  inflate() provides as much output as possible, until there is
+    no more input data or no more space in the output buffer (see below about
+    the flush parameter).
+
+    Before the call of inflate(), the application should ensure that at least
+  one of the actions is possible, by providing more input and/or consuming more
+  output, and updating the next_* and avail_* values accordingly.  If the
+  caller of inflate() does not provide both available input and available
+  output space, it is possible that there will be no progress made.  The
+  application can consume the uncompressed output when it wants, for example
+  when the output buffer is full (avail_out == 0), or after each call of
+  inflate().  If inflate returns Z_OK and with zero avail_out, it must be
+  called again after making room in the output buffer because there might be
+  more output pending.
+
+    The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,
+  Z_BLOCK, or Z_TREES.  Z_SYNC_FLUSH requests that inflate() flush as much
+  output as possible to the output buffer.  Z_BLOCK requests that inflate()
+  stop if and when it gets to the next deflate block boundary.  When decoding
+  the zlib or gzip format, this will cause inflate() to return immediately
+  after the header and before the first block.  When doing a raw inflate,
+  inflate() will go ahead and process the first block, and will return when it
+  gets to the end of that block, or when it runs out of data.
+
+    The Z_BLOCK option assists in appending to or combining deflate streams.
+  To assist in this, on return inflate() always sets strm->data_type to the
+  number of unused bits in the last byte taken from strm->next_in, plus 64 if
+  inflate() is currently decoding the last block in the deflate stream, plus
+  128 if inflate() returned immediately after decoding an end-of-block code or
+  decoding the complete header up to just before the first byte of the deflate
+  stream.  The end-of-block will not be indicated until all of the uncompressed
+  data from that block has been written to strm->next_out.  The number of
+  unused bits may in general be greater than seven, except when bit 7 of
+  data_type is set, in which case the number of unused bits will be less than
+  eight.  data_type is set as noted here every time inflate() returns for all
+  flush options, and so can be used to determine the amount of currently
+  consumed input in bits.
+
+    The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
+  end of each deflate block header is reached, before any actual data in that
+  block is decoded.  This allows the caller to determine the length of the
+  deflate block header for later use in random access within a deflate block.
+  256 is added to the value of strm->data_type when inflate() returns
+  immediately after reaching the end of the deflate block header.
+
+    inflate() should normally be called until it returns Z_STREAM_END or an
+  error.  However if all decompression is to be performed in a single step (a
+  single call of inflate), the parameter flush should be set to Z_FINISH.  In
+  this case all pending input is processed and all pending output is flushed;
+  avail_out must be large enough to hold all of the uncompressed data for the
+  operation to complete.  (The size of the uncompressed data may have been
+  saved by the compressor for this purpose.)  The use of Z_FINISH is not
+  required to perform an inflation in one step.  However it may be used to
+  inform inflate that a faster approach can be used for the single inflate()
+  call.  Z_FINISH also informs inflate to not maintain a sliding window if the
+  stream completes, which reduces inflate's memory footprint.  If the stream
+  does not complete, either because not all of the stream is provided or not
+  enough output space is provided, then a sliding window will be allocated and
+  inflate() can be called again to continue the operation as if Z_NO_FLUSH had
+  been used.
+
+     In this implementation, inflate() always flushes as much output as
+  possible to the output buffer, and always uses the faster approach on the
+  first call.  So the effects of the flush parameter in this implementation are
+  on the return value of inflate() as noted below, when inflate() returns early
+  when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of
+  memory for a sliding window when Z_FINISH is used.
+
+     If a preset dictionary is needed after this call (see inflateSetDictionary
+  below), inflate sets strm->adler to the Adler-32 checksum of the dictionary
+  chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
+  strm->adler to the Adler-32 checksum of all output produced so far (that is,
+  total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
+  below.  At the end of the stream, inflate() checks that its computed Adler-32
+  checksum is equal to that saved by the compressor and returns Z_STREAM_END
+  only if the checksum is correct.
+
+    inflate() can decompress and check either zlib-wrapped or gzip-wrapped
+  deflate data.  The header type is detected automatically, if requested when
+  initializing with inflateInit2().  Any information contained in the gzip
+  header is not retained unless inflateGetHeader() is used.  When processing
+  gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output
+  produced so far.  The CRC-32 is checked against the gzip trailer, as is the
+  uncompressed length, modulo 2^32.
+
+    inflate() returns Z_OK if some progress has been made (more input processed
+  or more output produced), Z_STREAM_END if the end of the compressed data has
+  been reached and all uncompressed output has been produced, Z_NEED_DICT if a
+  preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
+  corrupted (input stream not conforming to the zlib format or incorrect check
+  value, in which case strm->msg points to a string with a more specific
+  error), Z_STREAM_ERROR if the stream structure was inconsistent (for example
+  next_in or next_out was Z_NULL, or the state was inadvertently written over
+  by the application), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR
+  if no progress was possible or if there was not enough room in the output
+  buffer when Z_FINISH is used.  Note that Z_BUF_ERROR is not fatal, and
+  inflate() can be called again with more input and more output space to
+  continue decompressing.  If Z_DATA_ERROR is returned, the application may
+  then call inflateSync() to look for a good compression block if a partial
+  recovery of the data is to be attempted.
+*/
+
+
+ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
+/*
+     All dynamically allocated data structures for this stream are freed.
+   This function discards any unprocessed input and does not flush any pending
+   output.
+
+     inflateEnd returns Z_OK if success, or Z_STREAM_ERROR if the stream state
+   was inconsistent.
+*/
+
+
+                        /* Advanced functions */
+
+/*
+    The following functions are needed only in some special applications.
+*/
+
+/*
+ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
+                                     int  level,
+                                     int  method,
+                                     int  windowBits,
+                                     int  memLevel,
+                                     int  strategy));
+
+     This is another version of deflateInit with more compression options.  The
+   fields next_in, zalloc, zfree and opaque must be initialized before by the
+   caller.
+
+     The method parameter is the compression method.  It must be Z_DEFLATED in
+   this version of the library.
+
+     The windowBits parameter is the base two logarithm of the window size
+   (the size of the history buffer).  It should be in the range 8..15 for this
+   version of the library.  Larger values of this parameter result in better
+   compression at the expense of memory usage.  The default value is 15 if
+   deflateInit is used instead.
+
+     For the current implementation of deflate(), a windowBits value of 8 (a
+   window size of 256 bytes) is not supported.  As a result, a request for 8
+   will result in 9 (a 512-byte window).  In that case, providing 8 to
+   inflateInit2() will result in an error when the zlib header with 9 is
+   checked against the initialization of inflate().  The remedy is to not use 8
+   with deflateInit2() with this initialization, or at least in that case use 9
+   with inflateInit2().
+
+     windowBits can also be -8..-15 for raw deflate.  In this case, -windowBits
+   determines the window size.  deflate() will then generate raw deflate data
+   with no zlib header or trailer, and will not compute a check value.
+
+     windowBits can also be greater than 15 for optional gzip encoding.  Add
+   16 to windowBits to write a simple gzip header and trailer around the
+   compressed data instead of a zlib wrapper.  The gzip header will have no
+   file name, no extra data, no comment, no modification time (set to zero), no
+   header crc, and the operating system will be set to the appropriate value,
+   if the operating system was determined at compile time.  If a gzip stream is
+   being written, strm->adler is a CRC-32 instead of an Adler-32.
+
+     For raw deflate or gzip encoding, a request for a 256-byte window is
+   rejected as invalid, since only the zlib header provides a means of
+   transmitting the window size to the decompressor.
+
+     The memLevel parameter specifies how much memory should be allocated
+   for the internal compression state.  memLevel=1 uses minimum memory but is
+   slow and reduces compression ratio; memLevel=9 uses maximum memory for
+   optimal speed.  The default value is 8.  See zconf.h for total memory usage
+   as a function of windowBits and memLevel.
+
+     The strategy parameter is used to tune the compression algorithm.  Use the
+   value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
+   filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
+   string match), or Z_RLE to limit match distances to one (run-length
+   encoding).  Filtered data consists mostly of small values with a somewhat
+   random distribution.  In this case, the compression algorithm is tuned to
+   compress them better.  The effect of Z_FILTERED is to force more Huffman
+   coding and less string matching; it is somewhat intermediate between
+   Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY.  Z_RLE is designed to be almost as
+   fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data.  The
+   strategy parameter only affects the compression ratio but not the
+   correctness of the compressed output even if it is not set appropriately.
+   Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
+   decoder for special applications.
+
+     deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
+   method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is
+   incompatible with the version assumed by the caller (ZLIB_VERSION).  msg is
+   set to null if there is no error message.  deflateInit2 does not perform any
+   compression: this will be done by deflate().
+*/
+
+ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
+                                             const Bytef *dictionary,
+                                             uInt  dictLength));
+/*
+     Initializes the compression dictionary from the given byte sequence
+   without producing any compressed output.  When using the zlib format, this
+   function must be called immediately after deflateInit, deflateInit2 or
+   deflateReset, and before any call of deflate.  When doing raw deflate, this
+   function must be called either before any call of deflate, or immediately
+   after the completion of a deflate block, i.e. after all input has been
+   consumed and all output has been delivered when using any of the flush
+   options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH.  The
+   compressor and decompressor must use exactly the same dictionary (see
+   inflateSetDictionary).
+
+     The dictionary should consist of strings (byte sequences) that are likely
+   to be encountered later in the data to be compressed, with the most commonly
+   used strings preferably put towards the end of the dictionary.  Using a
+   dictionary is most useful when the data to be compressed is short and can be
+   predicted with good accuracy; the data can then be compressed better than
+   with the default empty dictionary.
+
+     Depending on the size of the compression data structures selected by
+   deflateInit or deflateInit2, a part of the dictionary may in effect be
+   discarded, for example if the dictionary is larger than the window size
+   provided in deflateInit or deflateInit2.  Thus the strings most likely to be
+   useful should be put at the end of the dictionary, not at the front.  In
+   addition, the current implementation of deflate will use at most the window
+   size minus 262 bytes of the provided dictionary.
+
+     Upon return of this function, strm->adler is set to the Adler-32 value
+   of the dictionary; the decompressor may later use this value to determine
+   which dictionary has been used by the compressor.  (The Adler-32 value
+   applies to the whole dictionary even if only a subset of the dictionary is
+   actually used by the compressor.) If a raw deflate was requested, then the
+   Adler-32 value is not computed and strm->adler is not set.
+
+     deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
+   parameter is invalid (e.g.  dictionary being Z_NULL) or the stream state is
+   inconsistent (for example if deflate has already been called for this stream
+   or if not at a block boundary for raw deflate).  deflateSetDictionary does
+   not perform any compression: this will be done by deflate().
+*/
+
+ZEXTERN int ZEXPORT deflateGetDictionary OF((z_streamp strm,
+                                             Bytef *dictionary,
+                                             uInt  *dictLength));
+/*
+     Returns the sliding dictionary being maintained by deflate.  dictLength is
+   set to the number of bytes in the dictionary, and that many bytes are copied
+   to dictionary.  dictionary must have enough space, where 32768 bytes is
+   always enough.  If deflateGetDictionary() is called with dictionary equal to
+   Z_NULL, then only the dictionary length is returned, and nothing is copied.
+   Similary, if dictLength is Z_NULL, then it is not set.
+
+     deflateGetDictionary() may return a length less than the window size, even
+   when more than the window size in input has been provided. It may return up
+   to 258 bytes less in that case, due to how zlib's implementation of deflate
+   manages the sliding window and lookahead for matches, where matches can be
+   up to 258 bytes long. If the application needs the last window-size bytes of
+   input, then that would need to be saved by the application outside of zlib.
+
+     deflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
+   stream state is inconsistent.
+*/
+
+ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
+                                    z_streamp source));
+/*
+     Sets the destination stream as a complete copy of the source stream.
+
+     This function can be useful when several compression strategies will be
+   tried, for example when there are several ways of pre-processing the input
+   data with a filter.  The streams that will be discarded should then be freed
+   by calling deflateEnd.  Note that deflateCopy duplicates the internal
+   compression state which can be quite large, so this strategy is slow and can
+   consume lots of memory.
+
+     deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
+   enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
+   (such as zalloc being Z_NULL).  msg is left unchanged in both source and
+   destination.
+*/
+
+ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
+/*
+     This function is equivalent to deflateEnd followed by deflateInit, but
+   does not free and reallocate the internal compression state.  The stream
+   will leave the compression level and any other attributes that may have been
+   set unchanged.
+
+     deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent (such as zalloc or state being Z_NULL).
+*/
+
+ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
+                                      int level,
+                                      int strategy));
+/*
+     Dynamically update the compression level and compression strategy.  The
+   interpretation of level and strategy is as in deflateInit2().  This can be
+   used to switch between compression and straight copy of the input data, or
+   to switch to a different kind of input data requiring a different strategy.
+   If the compression approach (which is a function of the level) or the
+   strategy is changed, and if any input has been consumed in a previous
+   deflate() call, then the input available so far is compressed with the old
+   level and strategy using deflate(strm, Z_BLOCK).  There are three approaches
+   for the compression levels 0, 1..3, and 4..9 respectively.  The new level
+   and strategy will take effect at the next call of deflate().
+
+     If a deflate(strm, Z_BLOCK) is performed by deflateParams(), and it does
+   not have enough output space to complete, then the parameter change will not
+   take effect.  In this case, deflateParams() can be called again with the
+   same parameters and more output space to try again.
+
+     In order to assure a change in the parameters on the first try, the
+   deflate stream should be flushed using deflate() with Z_BLOCK or other flush
+   request until strm.avail_out is not zero, before calling deflateParams().
+   Then no more input data should be provided before the deflateParams() call.
+   If this is done, the old level and strategy will be applied to the data
+   compressed before deflateParams(), and the new level and strategy will be
+   applied to the the data compressed after deflateParams().
+
+     deflateParams returns Z_OK on success, Z_STREAM_ERROR if the source stream
+   state was inconsistent or if a parameter was invalid, or Z_BUF_ERROR if
+   there was not enough output space to complete the compression of the
+   available input data before a change in the strategy or approach.  Note that
+   in the case of a Z_BUF_ERROR, the parameters are not changed.  A return
+   value of Z_BUF_ERROR is not fatal, in which case deflateParams() can be
+   retried with more output space.
+*/
+
+ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
+                                    int good_length,
+                                    int max_lazy,
+                                    int nice_length,
+                                    int max_chain));
+/*
+     Fine tune deflate's internal compression parameters.  This should only be
+   used by someone who understands the algorithm used by zlib's deflate for
+   searching for the best matching string, and even then only by the most
+   fanatic optimizer trying to squeeze out the last compressed bit for their
+   specific input data.  Read the deflate.c source code for the meaning of the
+   max_lazy, good_length, nice_length, and max_chain parameters.
+
+     deflateTune() can be called after deflateInit() or deflateInit2(), and
+   returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
+ */
+
+ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
+                                       uLong sourceLen));
+/*
+     deflateBound() returns an upper bound on the compressed size after
+   deflation of sourceLen bytes.  It must be called after deflateInit() or
+   deflateInit2(), and after deflateSetHeader(), if used.  This would be used
+   to allocate an output buffer for deflation in a single pass, and so would be
+   called before deflate().  If that first deflate() call is provided the
+   sourceLen input bytes, an output buffer allocated to the size returned by
+   deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed
+   to return Z_STREAM_END.  Note that it is possible for the compressed size to
+   be larger than the value returned by deflateBound() if flush options other
+   than Z_FINISH or Z_NO_FLUSH are used.
+*/
+
+ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm,
+                                       unsigned *pending,
+                                       int *bits));
+/*
+     deflatePending() returns the number of bytes and bits of output that have
+   been generated, but not yet provided in the available output.  The bytes not
+   provided would be due to the available output space having being consumed.
+   The number of bits of output not provided are between 0 and 7, where they
+   await more bits to join them in order to fill out a full byte.  If pending
+   or bits are Z_NULL, then those values are not set.
+
+     deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent.
+ */
+
+ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
+                                     int bits,
+                                     int value));
+/*
+     deflatePrime() inserts bits in the deflate output stream.  The intent
+   is that this function is used to start off the deflate output with the bits
+   leftover from a previous deflate stream when appending to it.  As such, this
+   function can only be used for raw deflate, and must be used before the first
+   deflate() call after a deflateInit2() or deflateReset().  bits must be less
+   than or equal to 16, and that many of the least significant bits of value
+   will be inserted in the output.
+
+     deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough
+   room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the
+   source stream state was inconsistent.
+*/
+
+ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
+                                         gz_headerp head));
+/*
+     deflateSetHeader() provides gzip header information for when a gzip
+   stream is requested by deflateInit2().  deflateSetHeader() may be called
+   after deflateInit2() or deflateReset() and before the first call of
+   deflate().  The text, time, os, extra field, name, and comment information
+   in the provided gz_header structure are written to the gzip header (xflag is
+   ignored -- the extra flags are set according to the compression level).  The
+   caller must assure that, if not Z_NULL, name and comment are terminated with
+   a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
+   available there.  If hcrc is true, a gzip header crc is included.  Note that
+   the current versions of the command-line version of gzip (up through version
+   1.3.x) do not support header crc's, and will report that it is a "multi-part
+   gzip file" and give up.
+
+     If deflateSetHeader is not used, the default gzip header has text false,
+   the time set to zero, and os set to 255, with no extra, name, or comment
+   fields.  The gzip header is returned to the default state by deflateReset().
+
+     deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent.
+*/
+
+/*
+ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
+                                     int  windowBits));
+
+     This is another version of inflateInit with an extra parameter.  The
+   fields next_in, avail_in, zalloc, zfree and opaque must be initialized
+   before by the caller.
+
+     The windowBits parameter is the base two logarithm of the maximum window
+   size (the size of the history buffer).  It should be in the range 8..15 for
+   this version of the library.  The default value is 15 if inflateInit is used
+   instead.  windowBits must be greater than or equal to the windowBits value
+   provided to deflateInit2() while compressing, or it must be equal to 15 if
+   deflateInit2() was not used.  If a compressed stream with a larger window
+   size is given as input, inflate() will return with the error code
+   Z_DATA_ERROR instead of trying to allocate a larger window.
+
+     windowBits can also be zero to request that inflate use the window size in
+   the zlib header of the compressed stream.
+
+     windowBits can also be -8..-15 for raw inflate.  In this case, -windowBits
+   determines the window size.  inflate() will then process raw deflate data,
+   not looking for a zlib or gzip header, not generating a check value, and not
+   looking for any check values for comparison at the end of the stream.  This
+   is for use with other formats that use the deflate compressed data format
+   such as zip.  Those formats provide their own check values.  If a custom
+   format is developed using the raw deflate format for compressed data, it is
+   recommended that a check value such as an Adler-32 or a CRC-32 be applied to
+   the uncompressed data as is done in the zlib, gzip, and zip formats.  For
+   most applications, the zlib format should be used as is.  Note that comments
+   above on the use in deflateInit2() applies to the magnitude of windowBits.
+
+     windowBits can also be greater than 15 for optional gzip decoding.  Add
+   32 to windowBits to enable zlib and gzip decoding with automatic header
+   detection, or add 16 to decode only the gzip format (the zlib format will
+   return a Z_DATA_ERROR).  If a gzip stream is being decoded, strm->adler is a
+   CRC-32 instead of an Adler-32.  Unlike the gunzip utility and gzread() (see
+   below), inflate() will not automatically decode concatenated gzip streams.
+   inflate() will return Z_STREAM_END at the end of the gzip stream.  The state
+   would need to be reset to continue decoding a subsequent gzip stream.
+
+     inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
+   version assumed by the caller, or Z_STREAM_ERROR if the parameters are
+   invalid, such as a null pointer to the structure.  msg is set to null if
+   there is no error message.  inflateInit2 does not perform any decompression
+   apart from possibly reading the zlib header if present: actual decompression
+   will be done by inflate().  (So next_in and avail_in may be modified, but
+   next_out and avail_out are unused and unchanged.) The current implementation
+   of inflateInit2() does not process any header information -- that is
+   deferred until inflate() is called.
+*/
+
+ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
+                                             const Bytef *dictionary,
+                                             uInt  dictLength));
+/*
+     Initializes the decompression dictionary from the given uncompressed byte
+   sequence.  This function must be called immediately after a call of inflate,
+   if that call returned Z_NEED_DICT.  The dictionary chosen by the compressor
+   can be determined from the Adler-32 value returned by that call of inflate.
+   The compressor and decompressor must use exactly the same dictionary (see
+   deflateSetDictionary).  For raw inflate, this function can be called at any
+   time to set the dictionary.  If the provided dictionary is smaller than the
+   window and there is already data in the window, then the provided dictionary
+   will amend what's there.  The application must insure that the dictionary
+   that was used for compression is provided.
+
+     inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
+   parameter is invalid (e.g.  dictionary being Z_NULL) or the stream state is
+   inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
+   expected one (incorrect Adler-32 value).  inflateSetDictionary does not
+   perform any decompression: this will be done by subsequent calls of
+   inflate().
+*/
+
+ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm,
+                                             Bytef *dictionary,
+                                             uInt  *dictLength));
+/*
+     Returns the sliding dictionary being maintained by inflate.  dictLength is
+   set to the number of bytes in the dictionary, and that many bytes are copied
+   to dictionary.  dictionary must have enough space, where 32768 bytes is
+   always enough.  If inflateGetDictionary() is called with dictionary equal to
+   Z_NULL, then only the dictionary length is returned, and nothing is copied.
+   Similary, if dictLength is Z_NULL, then it is not set.
+
+     inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
+   stream state is inconsistent.
+*/
+
+ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
+/*
+     Skips invalid compressed data until a possible full flush point (see above
+   for the description of deflate with Z_FULL_FLUSH) can be found, or until all
+   available input is skipped.  No output is provided.
+
+     inflateSync searches for a 00 00 FF FF pattern in the compressed data.
+   All full flush points have this pattern, but not all occurrences of this
+   pattern are full flush points.
+
+     inflateSync returns Z_OK if a possible full flush point has been found,
+   Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point
+   has been found, or Z_STREAM_ERROR if the stream structure was inconsistent.
+   In the success case, the application may save the current current value of
+   total_in which indicates where valid compressed data was found.  In the
+   error case, the application may repeatedly call inflateSync, providing more
+   input each time, until success or end of the input data.
+*/
+
+ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
+                                    z_streamp source));
+/*
+     Sets the destination stream as a complete copy of the source stream.
+
+     This function can be useful when randomly accessing a large stream.  The
+   first pass through the stream can periodically record the inflate state,
+   allowing restarting inflate at those points when randomly accessing the
+   stream.
+
+     inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
+   enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
+   (such as zalloc being Z_NULL).  msg is left unchanged in both source and
+   destination.
+*/
+
+ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
+/*
+     This function is equivalent to inflateEnd followed by inflateInit,
+   but does not free and reallocate the internal decompression state.  The
+   stream will keep attributes that may have been set by inflateInit2.
+
+     inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent (such as zalloc or state being Z_NULL).
+*/
+
+ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm,
+                                      int windowBits));
+/*
+     This function is the same as inflateReset, but it also permits changing
+   the wrap and window size requests.  The windowBits parameter is interpreted
+   the same as it is for inflateInit2.  If the window size is changed, then the
+   memory allocated for the window is freed, and the window will be reallocated
+   by inflate() if needed.
+
+     inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent (such as zalloc or state being Z_NULL), or if
+   the windowBits parameter is invalid.
+*/
+
+ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
+                                     int bits,
+                                     int value));
+/*
+     This function inserts bits in the inflate input stream.  The intent is
+   that this function is used to start inflating at a bit position in the
+   middle of a byte.  The provided bits will be used before any bytes are used
+   from next_in.  This function should only be used with raw inflate, and
+   should be used before the first inflate() call after inflateInit2() or
+   inflateReset().  bits must be less than or equal to 16, and that many of the
+   least significant bits of value will be inserted in the input.
+
+     If bits is negative, then the input stream bit buffer is emptied.  Then
+   inflatePrime() can be called again to put bits in the buffer.  This is used
+   to clear out bits leftover after feeding inflate a block description prior
+   to feeding inflate codes.
+
+     inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent.
+*/
+
+ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm));
+/*
+     This function returns two values, one in the lower 16 bits of the return
+   value, and the other in the remaining upper bits, obtained by shifting the
+   return value down 16 bits.  If the upper value is -1 and the lower value is
+   zero, then inflate() is currently decoding information outside of a block.
+   If the upper value is -1 and the lower value is non-zero, then inflate is in
+   the middle of a stored block, with the lower value equaling the number of
+   bytes from the input remaining to copy.  If the upper value is not -1, then
+   it is the number of bits back from the current bit position in the input of
+   the code (literal or length/distance pair) currently being processed.  In
+   that case the lower value is the number of bytes already emitted for that
+   code.
+
+     A code is being processed if inflate is waiting for more input to complete
+   decoding of the code, or if it has completed decoding but is waiting for
+   more output space to write the literal or match data.
+
+     inflateMark() is used to mark locations in the input data for random
+   access, which may be at bit positions, and to note those cases where the
+   output of a code may span boundaries of random access blocks.  The current
+   location in the input stream can be determined from avail_in and data_type
+   as noted in the description for the Z_BLOCK flush parameter for inflate.
+
+     inflateMark returns the value noted above, or -65536 if the provided
+   source stream state was inconsistent.
+*/
+
+ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
+                                         gz_headerp head));
+/*
+     inflateGetHeader() requests that gzip header information be stored in the
+   provided gz_header structure.  inflateGetHeader() may be called after
+   inflateInit2() or inflateReset(), and before the first call of inflate().
+   As inflate() processes the gzip stream, head->done is zero until the header
+   is completed, at which time head->done is set to one.  If a zlib stream is
+   being decoded, then head->done is set to -1 to indicate that there will be
+   no gzip header information forthcoming.  Note that Z_BLOCK or Z_TREES can be
+   used to force inflate() to return immediately after header processing is
+   complete and before any actual data is decompressed.
+
+     The text, time, xflags, and os fields are filled in with the gzip header
+   contents.  hcrc is set to true if there is a header CRC.  (The header CRC
+   was valid if done is set to one.) If extra is not Z_NULL, then extra_max
+   contains the maximum number of bytes to write to extra.  Once done is true,
+   extra_len contains the actual extra field length, and extra contains the
+   extra field, or that field truncated if extra_max is less than extra_len.
+   If name is not Z_NULL, then up to name_max characters are written there,
+   terminated with a zero unless the length is greater than name_max.  If
+   comment is not Z_NULL, then up to comm_max characters are written there,
+   terminated with a zero unless the length is greater than comm_max.  When any
+   of extra, name, or comment are not Z_NULL and the respective field is not
+   present in the header, then that field is set to Z_NULL to signal its
+   absence.  This allows the use of deflateSetHeader() with the returned
+   structure to duplicate the header.  However if those fields are set to
+   allocated memory, then the application will need to save those pointers
+   elsewhere so that they can be eventually freed.
+
+     If inflateGetHeader is not used, then the header information is simply
+   discarded.  The header is always checked for validity, including the header
+   CRC if present.  inflateReset() will reset the process to discard the header
+   information.  The application would need to call inflateGetHeader() again to
+   retrieve the header from the next gzip stream.
+
+     inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent.
+*/
+
+/*
+ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
+                                        unsigned char FAR *window));
+
+     Initialize the internal stream state for decompression using inflateBack()
+   calls.  The fields zalloc, zfree and opaque in strm must be initialized
+   before the call.  If zalloc and zfree are Z_NULL, then the default library-
+   derived memory allocation routines are used.  windowBits is the base two
+   logarithm of the window size, in the range 8..15.  window is a caller
+   supplied buffer of that size.  Except for special applications where it is
+   assured that deflate was used with small window sizes, windowBits must be 15
+   and a 32K byte window must be supplied to be able to decompress general
+   deflate streams.
+
+     See inflateBack() for the usage of these routines.
+
+     inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
+   the parameters are invalid, Z_MEM_ERROR if the internal state could not be
+   allocated, or Z_VERSION_ERROR if the version of the library does not match
+   the version of the header file.
+*/
+
+typedef unsigned (*in_func) OF((void FAR *,
+                                z_const unsigned char FAR * FAR *));
+typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
+
+ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
+                                    in_func in, void FAR *in_desc,
+                                    out_func out, void FAR *out_desc));
+/*
+     inflateBack() does a raw inflate with a single call using a call-back
+   interface for input and output.  This is potentially more efficient than
+   inflate() for file i/o applications, in that it avoids copying between the
+   output and the sliding window by simply making the window itself the output
+   buffer.  inflate() can be faster on modern CPUs when used with large
+   buffers.  inflateBack() trusts the application to not change the output
+   buffer passed by the output function, at least until inflateBack() returns.
+
+     inflateBackInit() must be called first to allocate the internal state
+   and to initialize the state with the user-provided window buffer.
+   inflateBack() may then be used multiple times to inflate a complete, raw
+   deflate stream with each call.  inflateBackEnd() is then called to free the
+   allocated state.
+
+     A raw deflate stream is one with no zlib or gzip header or trailer.
+   This routine would normally be used in a utility that reads zip or gzip
+   files and writes out uncompressed files.  The utility would decode the
+   header and process the trailer on its own, hence this routine expects only
+   the raw deflate stream to decompress.  This is different from the default
+   behavior of inflate(), which expects a zlib header and trailer around the
+   deflate stream.
+
+     inflateBack() uses two subroutines supplied by the caller that are then
+   called by inflateBack() for input and output.  inflateBack() calls those
+   routines until it reads a complete deflate stream and writes out all of the
+   uncompressed data, or until it encounters an error.  The function's
+   parameters and return types are defined above in the in_func and out_func
+   typedefs.  inflateBack() will call in(in_desc, &buf) which should return the
+   number of bytes of provided input, and a pointer to that input in buf.  If
+   there is no input available, in() must return zero -- buf is ignored in that
+   case -- and inflateBack() will return a buffer error.  inflateBack() will
+   call out(out_desc, buf, len) to write the uncompressed data buf[0..len-1].
+   out() should return zero on success, or non-zero on failure.  If out()
+   returns non-zero, inflateBack() will return with an error.  Neither in() nor
+   out() are permitted to change the contents of the window provided to
+   inflateBackInit(), which is also the buffer that out() uses to write from.
+   The length written by out() will be at most the window size.  Any non-zero
+   amount of input may be provided by in().
+
+     For convenience, inflateBack() can be provided input on the first call by
+   setting strm->next_in and strm->avail_in.  If that input is exhausted, then
+   in() will be called.  Therefore strm->next_in must be initialized before
+   calling inflateBack().  If strm->next_in is Z_NULL, then in() will be called
+   immediately for input.  If strm->next_in is not Z_NULL, then strm->avail_in
+   must also be initialized, and then if strm->avail_in is not zero, input will
+   initially be taken from strm->next_in[0 ..  strm->avail_in - 1].
+
+     The in_desc and out_desc parameters of inflateBack() is passed as the
+   first parameter of in() and out() respectively when they are called.  These
+   descriptors can be optionally used to pass any information that the caller-
+   supplied in() and out() functions need to do their job.
+
+     On return, inflateBack() will set strm->next_in and strm->avail_in to
+   pass back any unused input that was provided by the last in() call.  The
+   return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
+   if in() or out() returned an error, Z_DATA_ERROR if there was a format error
+   in the deflate stream (in which case strm->msg is set to indicate the nature
+   of the error), or Z_STREAM_ERROR if the stream was not properly initialized.
+   In the case of Z_BUF_ERROR, an input or output error can be distinguished
+   using strm->next_in which will be Z_NULL only if in() returned an error.  If
+   strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
+   non-zero.  (in() will always be called before out(), so strm->next_in is
+   assured to be defined if out() returns non-zero.)  Note that inflateBack()
+   cannot return Z_OK.
+*/
+
+ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
+/*
+     All memory allocated by inflateBackInit() is freed.
+
+     inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
+   state was inconsistent.
+*/
+
+ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
+/* Return flags indicating compile-time options.
+
+    Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
+     1.0: size of uInt
+     3.2: size of uLong
+     5.4: size of voidpf (pointer)
+     7.6: size of z_off_t
+
+    Compiler, assembler, and debug options:
+     8: ZLIB_DEBUG
+     9: ASMV or ASMINF -- use ASM code
+     10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
+     11: 0 (reserved)
+
+    One-time table building (smaller code, but not thread-safe if true):
+     12: BUILDFIXED -- build static block decoding tables when needed
+     13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
+     14,15: 0 (reserved)
+
+    Library content (indicates missing functionality):
+     16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
+                          deflate code when not needed)
+     17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
+                    and decode gzip streams (to avoid linking crc code)
+     18-19: 0 (reserved)
+
+    Operation variations (changes in library functionality):
+     20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
+     21: FASTEST -- deflate algorithm with only one, lowest compression level
+     22,23: 0 (reserved)
+
+    The sprintf variant used by gzprintf (zero is best):
+     24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
+     25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
+     26: 0 = returns value, 1 = void -- 1 means inferred string length returned
+
+    Remainder:
+     27-31: 0 (reserved)
+ */
+
+#ifndef Z_SOLO
+
+                        /* utility functions */
+
+/*
+     The following utility functions are implemented on top of the basic
+   stream-oriented functions.  To simplify the interface, some default options
+   are assumed (compression level and memory usage, standard memory allocation
+   functions).  The source code of these utility functions can be modified if
+   you need special options.
+*/
+
+ZEXTERN int ZEXPORT compress OF((Bytef *dest,   uLongf *destLen,
+                                 const Bytef *source, uLong sourceLen));
+/*
+     Compresses the source buffer into the destination buffer.  sourceLen is
+   the byte length of the source buffer.  Upon entry, destLen is the total size
+   of the destination buffer, which must be at least the value returned by
+   compressBound(sourceLen).  Upon exit, destLen is the actual size of the
+   compressed data.  compress() is equivalent to compress2() with a level
+   parameter of Z_DEFAULT_COMPRESSION.
+
+     compress returns Z_OK if success, Z_MEM_ERROR if there was not
+   enough memory, Z_BUF_ERROR if there was not enough room in the output
+   buffer.
+*/
+
+ZEXTERN int ZEXPORT compress2 OF((Bytef *dest,   uLongf *destLen,
+                                  const Bytef *source, uLong sourceLen,
+                                  int level));
+/*
+     Compresses the source buffer into the destination buffer.  The level
+   parameter has the same meaning as in deflateInit.  sourceLen is the byte
+   length of the source buffer.  Upon entry, destLen is the total size of the
+   destination buffer, which must be at least the value returned by
+   compressBound(sourceLen).  Upon exit, destLen is the actual size of the
+   compressed data.
+
+     compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_BUF_ERROR if there was not enough room in the output buffer,
+   Z_STREAM_ERROR if the level parameter is invalid.
+*/
+
+ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
+/*
+     compressBound() returns an upper bound on the compressed size after
+   compress() or compress2() on sourceLen bytes.  It would be used before a
+   compress() or compress2() call to allocate the destination buffer.
+*/
+
+ZEXTERN int ZEXPORT uncompress OF((Bytef *dest,   uLongf *destLen,
+                                   const Bytef *source, uLong sourceLen));
+/*
+     Decompresses the source buffer into the destination buffer.  sourceLen is
+   the byte length of the source buffer.  Upon entry, destLen is the total size
+   of the destination buffer, which must be large enough to hold the entire
+   uncompressed data.  (The size of the uncompressed data must have been saved
+   previously by the compressor and transmitted to the decompressor by some
+   mechanism outside the scope of this compression library.) Upon exit, destLen
+   is the actual size of the uncompressed data.
+
+     uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
+   enough memory, Z_BUF_ERROR if there was not enough room in the output
+   buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.  In
+   the case where there is not enough room, uncompress() will fill the output
+   buffer with the uncompressed data up to that point.
+*/
+
+ZEXTERN int ZEXPORT uncompress2 OF((Bytef *dest,   uLongf *destLen,
+                                    const Bytef *source, uLong *sourceLen));
+/*
+     Same as uncompress, except that sourceLen is a pointer, where the
+   length of the source is *sourceLen.  On return, *sourceLen is the number of
+   source bytes consumed.
+*/
+
+                        /* gzip file access functions */
+
+/*
+     This library supports reading and writing files in gzip (.gz) format with
+   an interface similar to that of stdio, using the functions that start with
+   "gz".  The gzip format is different from the zlib format.  gzip is a gzip
+   wrapper, documented in RFC 1952, wrapped around a deflate stream.
+*/
+
+typedef struct gzFile_s *gzFile;    /* semi-opaque gzip file descriptor */
+
+/*
+ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
+
+     Opens a gzip (.gz) file for reading or writing.  The mode parameter is as
+   in fopen ("rb" or "wb") but can also include a compression level ("wb9") or
+   a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only
+   compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F'
+   for fixed code compression as in "wb9F".  (See the description of
+   deflateInit2 for more information about the strategy parameter.)  'T' will
+   request transparent writing or appending with no compression and not using
+   the gzip format.
+
+     "a" can be used instead of "w" to request that the gzip stream that will
+   be written be appended to the file.  "+" will result in an error, since
+   reading and writing to the same gzip file is not supported.  The addition of
+   "x" when writing will create the file exclusively, which fails if the file
+   already exists.  On systems that support it, the addition of "e" when
+   reading or writing will set the flag to close the file on an execve() call.
+
+     These functions, as well as gzip, will read and decode a sequence of gzip
+   streams in a file.  The append function of gzopen() can be used to create
+   such a file.  (Also see gzflush() for another way to do this.)  When
+   appending, gzopen does not test whether the file begins with a gzip stream,
+   nor does it look for the end of the gzip streams to begin appending.  gzopen
+   will simply append a gzip stream to the existing file.
+
+     gzopen can be used to read a file which is not in gzip format; in this
+   case gzread will directly read from the file without decompression.  When
+   reading, this will be detected automatically by looking for the magic two-
+   byte gzip header.
+
+     gzopen returns NULL if the file could not be opened, if there was
+   insufficient memory to allocate the gzFile state, or if an invalid mode was
+   specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
+   errno can be checked to determine if the reason gzopen failed was that the
+   file could not be opened.
+*/
+
+ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
+/*
+     gzdopen associates a gzFile with the file descriptor fd.  File descriptors
+   are obtained from calls like open, dup, creat, pipe or fileno (if the file
+   has been previously opened with fopen).  The mode parameter is as in gzopen.
+
+     The next call of gzclose on the returned gzFile will also close the file
+   descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor
+   fd.  If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd,
+   mode);.  The duplicated descriptor should be saved to avoid a leak, since
+   gzdopen does not close fd if it fails.  If you are using fileno() to get the
+   file descriptor from a FILE *, then you will have to use dup() to avoid
+   double-close()ing the file descriptor.  Both gzclose() and fclose() will
+   close the associated file descriptor, so they need to have different file
+   descriptors.
+
+     gzdopen returns NULL if there was insufficient memory to allocate the
+   gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
+   provided, or '+' was provided), or if fd is -1.  The file descriptor is not
+   used until the next gz* read, write, seek, or close operation, so gzdopen
+   will not detect if fd is invalid (unless fd is -1).
+*/
+
+ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
+/*
+     Set the internal buffer size used by this library's functions.  The
+   default buffer size is 8192 bytes.  This function must be called after
+   gzopen() or gzdopen(), and before any other calls that read or write the
+   file.  The buffer memory allocation is always deferred to the first read or
+   write.  Three times that size in buffer space is allocated.  A larger buffer
+   size of, for example, 64K or 128K bytes will noticeably increase the speed
+   of decompression (reading).
+
+     The new buffer size also affects the maximum length for gzprintf().
+
+     gzbuffer() returns 0 on success, or -1 on failure, such as being called
+   too late.
+*/
+
+ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
+/*
+     Dynamically update the compression level or strategy.  See the description
+   of deflateInit2 for the meaning of these parameters.  Previously provided
+   data is flushed before the parameter change.
+
+     gzsetparams returns Z_OK if success, Z_STREAM_ERROR if the file was not
+   opened for writing, Z_ERRNO if there is an error writing the flushed data,
+   or Z_MEM_ERROR if there is a memory allocation error.
+*/
+
+ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
+/*
+     Reads the given number of uncompressed bytes from the compressed file.  If
+   the input file is not in gzip format, gzread copies the given number of
+   bytes into the buffer directly from the file.
+
+     After reaching the end of a gzip stream in the input, gzread will continue
+   to read, looking for another gzip stream.  Any number of gzip streams may be
+   concatenated in the input file, and will all be decompressed by gzread().
+   If something other than a gzip stream is encountered after a gzip stream,
+   that remaining trailing garbage is ignored (and no error is returned).
+
+     gzread can be used to read a gzip file that is being concurrently written.
+   Upon reaching the end of the input, gzread will return with the available
+   data.  If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then
+   gzclearerr can be used to clear the end of file indicator in order to permit
+   gzread to be tried again.  Z_OK indicates that a gzip stream was completed
+   on the last gzread.  Z_BUF_ERROR indicates that the input file ended in the
+   middle of a gzip stream.  Note that gzread does not return -1 in the event
+   of an incomplete gzip stream.  This error is deferred until gzclose(), which
+   will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip
+   stream.  Alternatively, gzerror can be used before gzclose to detect this
+   case.
+
+     gzread returns the number of uncompressed bytes actually read, less than
+   len for end of file, or -1 for error.  If len is too large to fit in an int,
+   then nothing is read, -1 is returned, and the error state is set to
+   Z_STREAM_ERROR.
+*/
+
+ZEXTERN z_size_t ZEXPORT gzfread OF((voidp buf, z_size_t size, z_size_t nitems,
+                                     gzFile file));
+/*
+     Read up to nitems items of size size from file to buf, otherwise operating
+   as gzread() does.  This duplicates the interface of stdio's fread(), with
+   size_t request and return types.  If the library defines size_t, then
+   z_size_t is identical to size_t.  If not, then z_size_t is an unsigned
+   integer type that can contain a pointer.
+
+     gzfread() returns the number of full items read of size size, or zero if
+   the end of the file was reached and a full item could not be read, or if
+   there was an error.  gzerror() must be consulted if zero is returned in
+   order to determine if there was an error.  If the multiplication of size and
+   nitems overflows, i.e. the product does not fit in a z_size_t, then nothing
+   is read, zero is returned, and the error state is set to Z_STREAM_ERROR.
+
+     In the event that the end of file is reached and only a partial item is
+   available at the end, i.e. the remaining uncompressed data length is not a
+   multiple of size, then the final partial item is nevetheless read into buf
+   and the end-of-file flag is set.  The length of the partial item read is not
+   provided, but could be inferred from the result of gztell().  This behavior
+   is the same as the behavior of fread() implementations in common libraries,
+   but it prevents the direct use of gzfread() to read a concurrently written
+   file, reseting and retrying on end-of-file, when size is not 1.
+*/
+
+ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
+                                voidpc buf, unsigned len));
+/*
+     Writes the given number of uncompressed bytes into the compressed file.
+   gzwrite returns the number of uncompressed bytes written or 0 in case of
+   error.
+*/
+
+ZEXTERN z_size_t ZEXPORT gzfwrite OF((voidpc buf, z_size_t size,
+                                      z_size_t nitems, gzFile file));
+/*
+     gzfwrite() writes nitems items of size size from buf to file, duplicating
+   the interface of stdio's fwrite(), with size_t request and return types.  If
+   the library defines size_t, then z_size_t is identical to size_t.  If not,
+   then z_size_t is an unsigned integer type that can contain a pointer.
+
+     gzfwrite() returns the number of full items written of size size, or zero
+   if there was an error.  If the multiplication of size and nitems overflows,
+   i.e. the product does not fit in a z_size_t, then nothing is written, zero
+   is returned, and the error state is set to Z_STREAM_ERROR.
+*/
+
+ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...));
+/*
+     Converts, formats, and writes the arguments to the compressed file under
+   control of the format string, as in fprintf.  gzprintf returns the number of
+   uncompressed bytes actually written, or a negative zlib error code in case
+   of error.  The number of uncompressed bytes written is limited to 8191, or
+   one less than the buffer size given to gzbuffer().  The caller should assure
+   that this limit is not exceeded.  If it is exceeded, then gzprintf() will
+   return an error (0) with nothing written.  In this case, there may also be a
+   buffer overflow with unpredictable consequences, which is possible only if
+   zlib was compiled with the insecure functions sprintf() or vsprintf()
+   because the secure snprintf() or vsnprintf() functions were not available.
+   This can be determined using zlibCompileFlags().
+*/
+
+ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
+/*
+     Writes the given null-terminated string to the compressed file, excluding
+   the terminating null character.
+
+     gzputs returns the number of characters written, or -1 in case of error.
+*/
+
+ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
+/*
+     Reads bytes from the compressed file until len-1 characters are read, or a
+   newline character is read and transferred to buf, or an end-of-file
+   condition is encountered.  If any characters are read or if len == 1, the
+   string is terminated with a null character.  If no characters are read due
+   to an end-of-file or len < 1, then the buffer is left untouched.
+
+     gzgets returns buf which is a null-terminated string, or it returns NULL
+   for end-of-file or in case of error.  If there was an error, the contents at
+   buf are indeterminate.
+*/
+
+ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
+/*
+     Writes c, converted to an unsigned char, into the compressed file.  gzputc
+   returns the value that was written, or -1 in case of error.
+*/
+
+ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
+/*
+     Reads one byte from the compressed file.  gzgetc returns this byte or -1
+   in case of end of file or error.  This is implemented as a macro for speed.
+   As such, it does not do all of the checking the other functions do.  I.e.
+   it does not check to see if file is NULL, nor whether the structure file
+   points to has been clobbered or not.
+*/
+
+ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
+/*
+     Push one character back onto the stream to be read as the first character
+   on the next read.  At least one character of push-back is allowed.
+   gzungetc() returns the character pushed, or -1 on failure.  gzungetc() will
+   fail if c is -1, and may fail if a character has been pushed but not read
+   yet.  If gzungetc is used immediately after gzopen or gzdopen, at least the
+   output buffer size of pushed characters is allowed.  (See gzbuffer above.)
+   The pushed character will be discarded if the stream is repositioned with
+   gzseek() or gzrewind().
+*/
+
+ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
+/*
+     Flushes all pending output into the compressed file.  The parameter flush
+   is as in the deflate() function.  The return value is the zlib error number
+   (see function gzerror below).  gzflush is only permitted when writing.
+
+     If the flush parameter is Z_FINISH, the remaining data is written and the
+   gzip stream is completed in the output.  If gzwrite() is called again, a new
+   gzip stream will be started in the output.  gzread() is able to read such
+   concatenated gzip streams.
+
+     gzflush should be called only when strictly necessary because it will
+   degrade compression if called too often.
+*/
+
+/*
+ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
+                                   z_off_t offset, int whence));
+
+     Sets the starting position for the next gzread or gzwrite on the given
+   compressed file.  The offset represents a number of bytes in the
+   uncompressed data stream.  The whence parameter is defined as in lseek(2);
+   the value SEEK_END is not supported.
+
+     If the file is opened for reading, this function is emulated but can be
+   extremely slow.  If the file is opened for writing, only forward seeks are
+   supported; gzseek then compresses a sequence of zeroes up to the new
+   starting position.
+
+     gzseek returns the resulting offset location as measured in bytes from
+   the beginning of the uncompressed stream, or -1 in case of error, in
+   particular if the file is opened for writing and the new starting position
+   would be before the current position.
+*/
+
+ZEXTERN int ZEXPORT    gzrewind OF((gzFile file));
+/*
+     Rewinds the given file. This function is supported only for reading.
+
+     gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
+*/
+
+/*
+ZEXTERN z_off_t ZEXPORT    gztell OF((gzFile file));
+
+     Returns the starting position for the next gzread or gzwrite on the given
+   compressed file.  This position represents a number of bytes in the
+   uncompressed data stream, and is zero when starting, even if appending or
+   reading a gzip stream from the middle of a file using gzdopen().
+
+     gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
+*/
+
+/*
+ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
+
+     Returns the current offset in the file being read or written.  This offset
+   includes the count of bytes that precede the gzip stream, for example when
+   appending or when using gzdopen() for reading.  When reading, the offset
+   does not include as yet unused buffered input.  This information can be used
+   for a progress indicator.  On error, gzoffset() returns -1.
+*/
+
+ZEXTERN int ZEXPORT gzeof OF((gzFile file));
+/*
+     Returns true (1) if the end-of-file indicator has been set while reading,
+   false (0) otherwise.  Note that the end-of-file indicator is set only if the
+   read tried to go past the end of the input, but came up short.  Therefore,
+   just like feof(), gzeof() may return false even if there is no more data to
+   read, in the event that the last read request was for the exact number of
+   bytes remaining in the input file.  This will happen if the input file size
+   is an exact multiple of the buffer size.
+
+     If gzeof() returns true, then the read functions will return no more data,
+   unless the end-of-file indicator is reset by gzclearerr() and the input file
+   has grown since the previous end of file was detected.
+*/
+
+ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
+/*
+     Returns true (1) if file is being copied directly while reading, or false
+   (0) if file is a gzip stream being decompressed.
+
+     If the input file is empty, gzdirect() will return true, since the input
+   does not contain a gzip stream.
+
+     If gzdirect() is used immediately after gzopen() or gzdopen() it will
+   cause buffers to be allocated to allow reading the file to determine if it
+   is a gzip file.  Therefore if gzbuffer() is used, it should be called before
+   gzdirect().
+
+     When writing, gzdirect() returns true (1) if transparent writing was
+   requested ("wT" for the gzopen() mode), or false (0) otherwise.  (Note:
+   gzdirect() is not needed when writing.  Transparent writing must be
+   explicitly requested, so the application already knows the answer.  When
+   linking statically, using gzdirect() will include all of the zlib code for
+   gzip file reading and decompression, which may not be desired.)
+*/
+
+ZEXTERN int ZEXPORT    gzclose OF((gzFile file));
+/*
+     Flushes all pending output if necessary, closes the compressed file and
+   deallocates the (de)compression state.  Note that once file is closed, you
+   cannot call gzerror with file, since its structures have been deallocated.
+   gzclose must not be called more than once on the same file, just as free
+   must not be called more than once on the same allocation.
+
+     gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
+   file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the
+   last read ended in the middle of a gzip stream, or Z_OK on success.
+*/
+
+ZEXTERN int ZEXPORT gzclose_r OF((gzFile file));
+ZEXTERN int ZEXPORT gzclose_w OF((gzFile file));
+/*
+     Same as gzclose(), but gzclose_r() is only for use when reading, and
+   gzclose_w() is only for use when writing or appending.  The advantage to
+   using these instead of gzclose() is that they avoid linking in zlib
+   compression or decompression code that is not used when only reading or only
+   writing respectively.  If gzclose() is used, then both compression and
+   decompression code will be included the application when linking to a static
+   zlib library.
+*/
+
+ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
+/*
+     Returns the error message for the last error which occurred on the given
+   compressed file.  errnum is set to zlib error number.  If an error occurred
+   in the file system and not in the compression library, errnum is set to
+   Z_ERRNO and the application may consult errno to get the exact error code.
+
+     The application must not modify the returned string.  Future calls to
+   this function may invalidate the previously returned string.  If file is
+   closed, then the string previously returned by gzerror will no longer be
+   available.
+
+     gzerror() should be used to distinguish errors from end-of-file for those
+   functions above that do not distinguish those cases in their return values.
+*/
+
+ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
+/*
+     Clears the error and end-of-file flags for file.  This is analogous to the
+   clearerr() function in stdio.  This is useful for continuing to read a gzip
+   file that is being written concurrently.
+*/
+
+#endif /* !Z_SOLO */
+
+                        /* checksum functions */
+
+/*
+     These functions are not related to compression but are exported
+   anyway because they might be useful in applications using the compression
+   library.
+*/
+
+ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
+/*
+     Update a running Adler-32 checksum with the bytes buf[0..len-1] and
+   return the updated checksum.  If buf is Z_NULL, this function returns the
+   required initial value for the checksum.
+
+     An Adler-32 checksum is almost as reliable as a CRC-32 but can be computed
+   much faster.
+
+   Usage example:
+
+     uLong adler = adler32(0L, Z_NULL, 0);
+
+     while (read_buffer(buffer, length) != EOF) {
+       adler = adler32(adler, buffer, length);
+     }
+     if (adler != original_adler) error();
+*/
+
+ZEXTERN uLong ZEXPORT adler32_z OF((uLong adler, const Bytef *buf,
+                                    z_size_t len));
+/*
+     Same as adler32(), but with a size_t length.
+*/
+
+/*
+ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
+                                          z_off_t len2));
+
+     Combine two Adler-32 checksums into one.  For two sequences of bytes, seq1
+   and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
+   each, adler1 and adler2.  adler32_combine() returns the Adler-32 checksum of
+   seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.  Note
+   that the z_off_t type (like off_t) is a signed integer.  If len2 is
+   negative, the result has no meaning or utility.
+*/
+
+ZEXTERN uLong ZEXPORT crc32   OF((uLong crc, const Bytef *buf, uInt len));
+/*
+     Update a running CRC-32 with the bytes buf[0..len-1] and return the
+   updated CRC-32.  If buf is Z_NULL, this function returns the required
+   initial value for the crc.  Pre- and post-conditioning (one's complement) is
+   performed within this function so it shouldn't be done by the application.
+
+   Usage example:
+
+     uLong crc = crc32(0L, Z_NULL, 0);
+
+     while (read_buffer(buffer, length) != EOF) {
+       crc = crc32(crc, buffer, length);
+     }
+     if (crc != original_crc) error();
+*/
+
+ZEXTERN uLong ZEXPORT crc32_z OF((uLong adler, const Bytef *buf,
+                                  z_size_t len));
+/*
+     Same as crc32(), but with a size_t length.
+*/
+
+/*
+ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
+
+     Combine two CRC-32 check values into one.  For two sequences of bytes,
+   seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
+   calculated for each, crc1 and crc2.  crc32_combine() returns the CRC-32
+   check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
+   len2.
+*/
+
+
+                        /* various hacks, don't look :) */
+
+/* deflateInit and inflateInit are macros to allow checking the zlib version
+ * and the compiler's view of z_stream:
+ */
+ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
+                                     const char *version, int stream_size));
+ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
+                                     const char *version, int stream_size));
+ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int  level, int  method,
+                                      int windowBits, int memLevel,
+                                      int strategy, const char *version,
+                                      int stream_size));
+ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int  windowBits,
+                                      const char *version, int stream_size));
+ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
+                                         unsigned char FAR *window,
+                                         const char *version,
+                                         int stream_size));
+#ifdef Z_PREFIX_SET
+#  define z_deflateInit(strm, level) \
+          deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define z_inflateInit(strm) \
+          inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define z_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
+          deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
+                        (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define z_inflateInit2(strm, windowBits) \
+          inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
+                        (int)sizeof(z_stream))
+#  define z_inflateBackInit(strm, windowBits, window) \
+          inflateBackInit_((strm), (windowBits), (window), \
+                           ZLIB_VERSION, (int)sizeof(z_stream))
+#else
+#  define deflateInit(strm, level) \
+          deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define inflateInit(strm) \
+          inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
+          deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
+                        (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define inflateInit2(strm, windowBits) \
+          inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
+                        (int)sizeof(z_stream))
+#  define inflateBackInit(strm, windowBits, window) \
+          inflateBackInit_((strm), (windowBits), (window), \
+                           ZLIB_VERSION, (int)sizeof(z_stream))
+#endif
+
+#ifndef Z_SOLO
+
+/* gzgetc() macro and its supporting function and exposed data structure.  Note
+ * that the real internal state is much larger than the exposed structure.
+ * This abbreviated structure exposes just enough for the gzgetc() macro.  The
+ * user should not mess with these exposed elements, since their names or
+ * behavior could change in the future, perhaps even capriciously.  They can
+ * only be used by the gzgetc() macro.  You have been warned.
+ */
+struct gzFile_s {
+    unsigned have;
+    unsigned char *next;
+    z_off64_t pos;
+};
+ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file));  /* backward compatibility */
+#ifdef Z_PREFIX_SET
+#  undef z_gzgetc
+#  define z_gzgetc(g) \
+          ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
+#else
+#  define gzgetc(g) \
+          ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
+#endif
+
+/* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
+ * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
+ * both are true, the application gets the *64 functions, and the regular
+ * functions are changed to 64 bits) -- in case these are set on systems
+ * without large file support, _LFS64_LARGEFILE must also be true
+ */
+#ifdef Z_LARGE64
+   ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
+   ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
+   ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
+   ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
+   ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t));
+   ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t));
+#endif
+
+#if !defined(ZLIB_INTERNAL) && defined(Z_WANT64)
+#  ifdef Z_PREFIX_SET
+#    define z_gzopen z_gzopen64
+#    define z_gzseek z_gzseek64
+#    define z_gztell z_gztell64
+#    define z_gzoffset z_gzoffset64
+#    define z_adler32_combine z_adler32_combine64
+#    define z_crc32_combine z_crc32_combine64
+#  else
+#    define gzopen gzopen64
+#    define gzseek gzseek64
+#    define gztell gztell64
+#    define gzoffset gzoffset64
+#    define adler32_combine adler32_combine64
+#    define crc32_combine crc32_combine64
+#  endif
+#  ifndef Z_LARGE64
+     ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
+     ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int));
+     ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile));
+     ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile));
+     ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
+     ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
+#  endif
+#else
+   ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
+   ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int));
+   ZEXTERN z_off_t ZEXPORT gztell OF((gzFile));
+   ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile));
+   ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
+   ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
+#endif
+
+#else /* Z_SOLO */
+
+   ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
+   ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
+
+#endif /* !Z_SOLO */
+
+/* undocumented functions */
+ZEXTERN const char   * ZEXPORT zError           OF((int));
+ZEXTERN int            ZEXPORT inflateSyncPoint OF((z_streamp));
+ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table    OF((void));
+ZEXTERN int            ZEXPORT inflateUndermine OF((z_streamp, int));
+ZEXTERN int            ZEXPORT inflateValidate OF((z_streamp, int));
+ZEXTERN unsigned long  ZEXPORT inflateCodesUsed OF ((z_streamp));
+ZEXTERN int            ZEXPORT inflateResetKeep OF((z_streamp));
+ZEXTERN int            ZEXPORT deflateResetKeep OF((z_streamp));
+#if (defined(_WIN32) || defined(__CYGWIN__)) && !defined(Z_SOLO)
+ZEXTERN gzFile         ZEXPORT gzopen_w OF((const wchar_t *path,
+                                            const char *mode));
+#endif
+#if defined(STDC) || defined(Z_HAVE_STDARG_H)
+#  ifndef Z_SOLO
+ZEXTERN int            ZEXPORTVA gzvprintf Z_ARG((gzFile file,
+                                                  const char *format,
+                                                  va_list va));
+#  endif
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ZLIB_H */

vendor/libgit2-sys/libgit2/deps/zlib/zutil.c

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/zutil.c b/vendor/libgit2-sys/libgit2/deps/zlib/zutil.c
new file mode 100644
index 0000000..a76c6b0
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/zutil.c
@@ -0,0 +1,325 @@
+/* zutil.c -- target dependent utility functions for the compression library
+ * Copyright (C) 1995-2017 Jean-loup Gailly
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* @(#) $Id$ */
+
+#include "zutil.h"
+#ifndef Z_SOLO
+#  include "gzguts.h"
+#endif
+
+z_const char * const z_errmsg[10] = {
+    (z_const char *)"need dictionary",     /* Z_NEED_DICT       2  */
+    (z_const char *)"stream end",          /* Z_STREAM_END      1  */
+    (z_const char *)"",                    /* Z_OK              0  */
+    (z_const char *)"file error",          /* Z_ERRNO         (-1) */
+    (z_const char *)"stream error",        /* Z_STREAM_ERROR  (-2) */
+    (z_const char *)"data error",          /* Z_DATA_ERROR    (-3) */
+    (z_const char *)"insufficient memory", /* Z_MEM_ERROR     (-4) */
+    (z_const char *)"buffer error",        /* Z_BUF_ERROR     (-5) */
+    (z_const char *)"incompatible version",/* Z_VERSION_ERROR (-6) */
+    (z_const char *)""
+};
+
+
+const char * ZEXPORT zlibVersion()
+{
+    return ZLIB_VERSION;
+}
+
+uLong ZEXPORT zlibCompileFlags()
+{
+    uLong flags;
+
+    flags = 0;
+    switch ((int)(sizeof(uInt))) {
+    case 2:     break;
+    case 4:     flags += 1;     break;
+    case 8:     flags += 2;     break;
+    default:    flags += 3;
+    }
+    switch ((int)(sizeof(uLong))) {
+    case 2:     break;
+    case 4:     flags += 1 << 2;        break;
+    case 8:     flags += 2 << 2;        break;
+    default:    flags += 3 << 2;
+    }
+    switch ((int)(sizeof(voidpf))) {
+    case 2:     break;
+    case 4:     flags += 1 << 4;        break;
+    case 8:     flags += 2 << 4;        break;
+    default:    flags += 3 << 4;
+    }
+    switch ((int)(sizeof(z_off_t))) {
+    case 2:     break;
+    case 4:     flags += 1 << 6;        break;
+    case 8:     flags += 2 << 6;        break;
+    default:    flags += 3 << 6;
+    }
+#ifdef ZLIB_DEBUG
+    flags += 1 << 8;
+#endif
+#if defined(ASMV) || defined(ASMINF)
+    flags += 1 << 9;
+#endif
+#ifdef ZLIB_WINAPI
+    flags += 1 << 10;
+#endif
+#ifdef BUILDFIXED
+    flags += 1 << 12;
+#endif
+#ifdef DYNAMIC_CRC_TABLE
+    flags += 1 << 13;
+#endif
+#ifdef NO_GZCOMPRESS
+    flags += 1L << 16;
+#endif
+#ifdef NO_GZIP
+    flags += 1L << 17;
+#endif
+#ifdef PKZIP_BUG_WORKAROUND
+    flags += 1L << 20;
+#endif
+#ifdef FASTEST
+    flags += 1L << 21;
+#endif
+#if defined(STDC) || defined(Z_HAVE_STDARG_H)
+#  ifdef NO_vsnprintf
+    flags += 1L << 25;
+#    ifdef HAS_vsprintf_void
+    flags += 1L << 26;
+#    endif
+#  else
+#    ifdef HAS_vsnprintf_void
+    flags += 1L << 26;
+#    endif
+#  endif
+#else
+    flags += 1L << 24;
+#  ifdef NO_snprintf
+    flags += 1L << 25;
+#    ifdef HAS_sprintf_void
+    flags += 1L << 26;
+#    endif
+#  else
+#    ifdef HAS_snprintf_void
+    flags += 1L << 26;
+#    endif
+#  endif
+#endif
+    return flags;
+}
+
+#ifdef ZLIB_DEBUG
+#include <stdlib.h>
+#  ifndef verbose
+#    define verbose 0
+#  endif
+int ZLIB_INTERNAL z_verbose = verbose;
+
+void ZLIB_INTERNAL z_error (m)
+    char *m;
+{
+    fprintf(stderr, "%s\n", m);
+    exit(1);
+}
+#endif
+
+/* exported to allow conversion of error code to string for compress() and
+ * uncompress()
+ */
+const char * ZEXPORT zError(err)
+    int err;
+{
+    return ERR_MSG(err);
+}
+
+#if defined(_WIN32_WCE)
+    /* The Microsoft C Run-Time Library for Windows CE doesn't have
+     * errno.  We define it as a global variable to simplify porting.
+     * Its value is always 0 and should not be used.
+     */
+    int errno = 0;
+#endif
+
+#ifndef HAVE_MEMCPY
+
+void ZLIB_INTERNAL zmemcpy(dest, source, len)
+    Bytef* dest;
+    const Bytef* source;
+    uInt  len;
+{
+    if (len == 0) return;
+    do {
+        *dest++ = *source++; /* ??? to be unrolled */
+    } while (--len != 0);
+}
+
+int ZLIB_INTERNAL zmemcmp(s1, s2, len)
+    const Bytef* s1;
+    const Bytef* s2;
+    uInt  len;
+{
+    uInt j;
+
+    for (j = 0; j < len; j++) {
+        if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
+    }
+    return 0;
+}
+
+void ZLIB_INTERNAL zmemzero(dest, len)
+    Bytef* dest;
+    uInt  len;
+{
+    if (len == 0) return;
+    do {
+        *dest++ = 0;  /* ??? to be unrolled */
+    } while (--len != 0);
+}
+#endif
+
+#ifndef Z_SOLO
+
+#ifdef SYS16BIT
+
+#ifdef __TURBOC__
+/* Turbo C in 16-bit mode */
+
+#  define MY_ZCALLOC
+
+/* Turbo C malloc() does not allow dynamic allocation of 64K bytes
+ * and farmalloc(64K) returns a pointer with an offset of 8, so we
+ * must fix the pointer. Warning: the pointer must be put back to its
+ * original form in order to free it, use zcfree().
+ */
+
+#define MAX_PTR 10
+/* 10*64K = 640K */
+
+local int next_ptr = 0;
+
+typedef struct ptr_table_s {
+    voidpf org_ptr;
+    voidpf new_ptr;
+} ptr_table;
+
+local ptr_table table[MAX_PTR];
+/* This table is used to remember the original form of pointers
+ * to large buffers (64K). Such pointers are normalized with a zero offset.
+ * Since MSDOS is not a preemptive multitasking OS, this table is not
+ * protected from concurrent access. This hack doesn't work anyway on
+ * a protected system like OS/2. Use Microsoft C instead.
+ */
+
+voidpf ZLIB_INTERNAL zcalloc (voidpf opaque, unsigned items, unsigned size)
+{
+    voidpf buf;
+    ulg bsize = (ulg)items*size;
+
+    (void)opaque;
+
+    /* If we allocate less than 65520 bytes, we assume that farmalloc
+     * will return a usable pointer which doesn't have to be normalized.
+     */
+    if (bsize < 65520L) {
+        buf = farmalloc(bsize);
+        if (*(ush*)&buf != 0) return buf;
+    } else {
+        buf = farmalloc(bsize + 16L);
+    }
+    if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
+    table[next_ptr].org_ptr = buf;
+
+    /* Normalize the pointer to seg:0 */
+    *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
+    *(ush*)&buf = 0;
+    table[next_ptr++].new_ptr = buf;
+    return buf;
+}
+
+void ZLIB_INTERNAL zcfree (voidpf opaque, voidpf ptr)
+{
+    int n;
+
+    (void)opaque;
+
+    if (*(ush*)&ptr != 0) { /* object < 64K */
+        farfree(ptr);
+        return;
+    }
+    /* Find the original pointer */
+    for (n = 0; n < next_ptr; n++) {
+        if (ptr != table[n].new_ptr) continue;
+
+        farfree(table[n].org_ptr);
+        while (++n < next_ptr) {
+            table[n-1] = table[n];
+        }
+        next_ptr--;
+        return;
+    }
+    Assert(0, "zcfree: ptr not found");
+}
+
+#endif /* __TURBOC__ */
+
+
+#ifdef M_I86
+/* Microsoft C in 16-bit mode */
+
+#  define MY_ZCALLOC
+
+#if (!defined(_MSC_VER) || (_MSC_VER <= 600))
+#  define _halloc  halloc
+#  define _hfree   hfree
+#endif
+
+voidpf ZLIB_INTERNAL zcalloc (voidpf opaque, uInt items, uInt size)
+{
+    (void)opaque;
+    return _halloc((long)items, size);
+}
+
+void ZLIB_INTERNAL zcfree (voidpf opaque, voidpf ptr)
+{
+    (void)opaque;
+    _hfree(ptr);
+}
+
+#endif /* M_I86 */
+
+#endif /* SYS16BIT */
+
+
+#ifndef MY_ZCALLOC /* Any system without a special alloc function */
+
+#ifndef STDC
+extern voidp  malloc OF((uInt size));
+extern voidp  calloc OF((uInt items, uInt size));
+extern void   free   OF((voidpf ptr));
+#endif
+
+voidpf ZLIB_INTERNAL zcalloc (opaque, items, size)
+    voidpf opaque;
+    unsigned items;
+    unsigned size;
+{
+    (void)opaque;
+    return sizeof(uInt) > 2 ? (voidpf)malloc(items * size) :
+                              (voidpf)calloc(items, size);
+}
+
+void ZLIB_INTERNAL zcfree (opaque, ptr)
+    voidpf opaque;
+    voidpf ptr;
+{
+    (void)opaque;
+    free(ptr);
+}
+
+#endif /* MY_ZCALLOC */
+
+#endif /* !Z_SOLO */

vendor/libgit2-sys/libgit2/deps/zlib/zutil.h

diff --git a/vendor/libgit2-sys/libgit2/deps/zlib/zutil.h b/vendor/libgit2-sys/libgit2/deps/zlib/zutil.h
new file mode 100644
index 0000000..b079ea6
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/deps/zlib/zutil.h
@@ -0,0 +1,271 @@
+/* zutil.h -- internal interface and configuration of the compression library
+ * Copyright (C) 1995-2016 Jean-loup Gailly, Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* @(#) $Id$ */
+
+#ifndef ZUTIL_H
+#define ZUTIL_H
+
+#ifdef HAVE_HIDDEN
+#  define ZLIB_INTERNAL __attribute__((visibility ("hidden")))
+#else
+#  define ZLIB_INTERNAL
+#endif
+
+#include "zlib.h"
+
+#if defined(STDC) && !defined(Z_SOLO)
+#  if !(defined(_WIN32_WCE) && defined(_MSC_VER))
+#    include <stddef.h>
+#  endif
+#  include <string.h>
+#  include <stdlib.h>
+#endif
+
+#ifdef Z_SOLO
+   typedef long ptrdiff_t;  /* guess -- will be caught if guess is wrong */
+#endif
+
+#ifndef local
+#  define local static
+#endif
+/* since "static" is used to mean two completely different things in C, we
+   define "local" for the non-static meaning of "static", for readability
+   (compile with -Dlocal if your debugger can't find static symbols) */
+
+typedef unsigned char  uch;
+typedef uch FAR uchf;
+typedef unsigned short ush;
+typedef ush FAR ushf;
+typedef unsigned long  ulg;
+
+extern z_const char * const z_errmsg[10]; /* indexed by 2-zlib_error */
+/* (size given to avoid silly warnings with Visual C++) */
+
+#define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)]
+
+#define ERR_RETURN(strm,err) \
+  return (strm->msg = ERR_MSG(err), (err))
+/* To be used only when the state is known to be valid */
+
+        /* common constants */
+
+#ifndef DEF_WBITS
+#  define DEF_WBITS MAX_WBITS
+#endif
+/* default windowBits for decompression. MAX_WBITS is for compression only */
+
+#if MAX_MEM_LEVEL >= 8
+#  define DEF_MEM_LEVEL 8
+#else
+#  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
+#endif
+/* default memLevel */
+
+#define STORED_BLOCK 0
+#define STATIC_TREES 1
+#define DYN_TREES    2
+/* The three kinds of block type */
+
+#define MIN_MATCH  3
+#define MAX_MATCH  258
+/* The minimum and maximum match lengths */
+
+#define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */
+
+        /* target dependencies */
+
+#if defined(MSDOS) || (defined(WINDOWS) && !defined(WIN32))
+#  define OS_CODE  0x00
+#  ifndef Z_SOLO
+#    if defined(__TURBOC__) || defined(__BORLANDC__)
+#      if (__STDC__ == 1) && (defined(__LARGE__) || defined(__COMPACT__))
+         /* Allow compilation with ANSI keywords only enabled */
+         void _Cdecl farfree( void *block );
+         void *_Cdecl farmalloc( unsigned long nbytes );
+#      else
+#        include <alloc.h>
+#      endif
+#    else /* MSC or DJGPP */
+#      include <malloc.h>
+#    endif
+#  endif
+#endif
+
+#ifdef AMIGA
+#  define OS_CODE  1
+#endif
+
+#if defined(VAXC) || defined(VMS)
+#  define OS_CODE  2
+#  define F_OPEN(name, mode) \
+     fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512")
+#endif
+
+#ifdef __370__
+#  if __TARGET_LIB__ < 0x20000000
+#    define OS_CODE 4
+#  elif __TARGET_LIB__ < 0x40000000
+#    define OS_CODE 11
+#  else
+#    define OS_CODE 8
+#  endif
+#endif
+
+#if defined(ATARI) || defined(atarist)
+#  define OS_CODE  5
+#endif
+
+#ifdef OS2
+#  define OS_CODE  6
+#  if defined(M_I86) && !defined(Z_SOLO)
+#    include <malloc.h>
+#  endif
+#endif
+
+#if defined(MACOS) || defined(TARGET_OS_MAC)
+#  define OS_CODE  7
+#  ifndef Z_SOLO
+#    if defined(__MWERKS__) && __dest_os != __be_os && __dest_os != __win32_os
+#      include <unix.h> /* for fdopen */
+#    else
+#      ifndef fdopen
+#        define fdopen(fd,mode) NULL /* No fdopen() */
+#      endif
+#    endif
+#  endif
+#endif
+
+#ifdef __acorn
+#  define OS_CODE 13
+#endif
+
+#if defined(WIN32) && !defined(__CYGWIN__)
+#  define OS_CODE  10
+#endif
+
+#ifdef _BEOS_
+#  define OS_CODE  16
+#endif
+
+#ifdef __TOS_OS400__
+#  define OS_CODE 18
+#endif
+
+#ifdef __APPLE__
+#  define OS_CODE 19
+#endif
+
+#if defined(_BEOS_) || defined(RISCOS)
+#  define fdopen(fd,mode) NULL /* No fdopen() */
+#endif
+
+#if (defined(_MSC_VER) && (_MSC_VER > 600)) && !defined __INTERIX
+#  if defined(_WIN32_WCE)
+#    define fdopen(fd,mode) NULL /* No fdopen() */
+#    ifndef _PTRDIFF_T_DEFINED
+       typedef int ptrdiff_t;
+#      define _PTRDIFF_T_DEFINED
+#    endif
+#  else
+#    define fdopen(fd,type)  _fdopen(fd,type)
+#  endif
+#endif
+
+#if defined(__BORLANDC__) && !defined(MSDOS)
+  #pragma warn -8004
+  #pragma warn -8008
+  #pragma warn -8066
+#endif
+
+/* provide prototypes for these when building zlib without LFS */
+#if !defined(_WIN32) && \
+    (!defined(_LARGEFILE64_SOURCE) || _LFS64_LARGEFILE-0 == 0)
+    ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
+    ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
+#endif
+
+        /* common defaults */
+
+#ifndef OS_CODE
+#  define OS_CODE  3     /* assume Unix */
+#endif
+
+#ifndef F_OPEN
+#  define F_OPEN(name, mode) fopen((name), (mode))
+#endif
+
+         /* functions */
+
+#if defined(pyr) || defined(Z_SOLO)
+#  define NO_MEMCPY
+#endif
+#if defined(SMALL_MEDIUM) && !defined(_MSC_VER) && !defined(__SC__)
+ /* Use our own functions for small and medium model with MSC <= 5.0.
+  * You may have to use the same strategy for Borland C (untested).
+  * The __SC__ check is for Symantec.
+  */
+#  define NO_MEMCPY
+#endif
+#if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
+#  define HAVE_MEMCPY
+#endif
+#ifdef HAVE_MEMCPY
+#  ifdef SMALL_MEDIUM /* MSDOS small or medium model */
+#    define zmemcpy _fmemcpy
+#    define zmemcmp _fmemcmp
+#    define zmemzero(dest, len) _fmemset(dest, 0, len)
+#  else
+#    define zmemcpy memcpy
+#    define zmemcmp memcmp
+#    define zmemzero(dest, len) memset(dest, 0, len)
+#  endif
+#else
+   void ZLIB_INTERNAL zmemcpy OF((Bytef* dest, const Bytef* source, uInt len));
+   int ZLIB_INTERNAL zmemcmp OF((const Bytef* s1, const Bytef* s2, uInt len));
+   void ZLIB_INTERNAL zmemzero OF((Bytef* dest, uInt len));
+#endif
+
+/* Diagnostic functions */
+#ifdef ZLIB_DEBUG
+#  include <stdio.h>
+   extern int ZLIB_INTERNAL z_verbose;
+   extern void ZLIB_INTERNAL z_error OF((char *m));
+#  define Assert(cond,msg) {if(!(cond)) z_error(msg);}
+#  define Trace(x) {if (z_verbose>=0) fprintf x ;}
+#  define Tracev(x) {if (z_verbose>0) fprintf x ;}
+#  define Tracevv(x) {if (z_verbose>1) fprintf x ;}
+#  define Tracec(c,x) {if (z_verbose>0 && (c)) fprintf x ;}
+#  define Tracecv(c,x) {if (z_verbose>1 && (c)) fprintf x ;}
+#else
+#  define Assert(cond,msg)
+#  define Trace(x)
+#  define Tracev(x)
+#  define Tracevv(x)
+#  define Tracec(c,x)
+#  define Tracecv(c,x)
+#endif
+
+#ifndef Z_SOLO
+   voidpf ZLIB_INTERNAL zcalloc OF((voidpf opaque, unsigned items,
+                                    unsigned size));
+   void ZLIB_INTERNAL zcfree  OF((voidpf opaque, voidpf ptr));
+#endif
+
+#define ZALLOC(strm, items, size) \
+           (*((strm)->zalloc))((strm)->opaque, (items), (size))
+#define ZFREE(strm, addr)  (*((strm)->zfree))((strm)->opaque, (voidpf)(addr))
+#define TRY_FREE(s, p) {if (p) ZFREE(s, p);}
+
+/* Reverse the bytes in a 32-bit value */
+#define ZSWAP32(q) ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \
+                    (((q) & 0xff00) << 8) + (((q) & 0xff) << 24))
+
+#endif /* ZUTIL_H */

vendor/libgit2-sys/libgit2/docs/checkout-internals.md

diff --git a/vendor/libgit2-sys/libgit2/docs/checkout-internals.md b/vendor/libgit2-sys/libgit2/docs/checkout-internals.md
new file mode 100644
index 0000000..e0b2583
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/docs/checkout-internals.md
@@ -0,0 +1,231 @@
+Checkout Internals
+==================
+
+Checkout has to handle a lot of different cases.  It examines the
+differences between the target tree, the baseline tree and the working
+directory, plus the contents of the index, and groups files into five
+categories:
+
+1. UNMODIFIED - Files that match in all places.
+2. SAFE - Files where the working directory and the baseline content
+   match that can be safely updated to the target.
+3. DIRTY/MISSING - Files where the working directory differs from the
+   baseline but there is no conflicting change with the target.  One
+   example is a file that doesn't exist in the working directory - no
+   data would be lost as a result of writing this file.  Which action
+   will be taken with these files depends on the options you use.
+4. CONFLICTS - Files where changes in the working directory conflict
+   with changes to be applied by the target.  If conflicts are found,
+   they prevent any other modifications from being made (although there
+   are options to override that and force the update, of course).
+5. UNTRACKED/IGNORED - Files in the working directory that are untracked
+   or ignored (i.e. only in the working directory, not the other places).
+
+Right now, this classification is done via 3 iterators (for the three
+trees), with a final lookup in the index.  At some point, this may move to
+a 4 iterator version to incorporate the index better.
+
+The actual checkout is done in five phases (at least right now).
+
+1. The diff between the baseline and the target tree is used as a base
+   list of possible updates to be applied.
+2. Iterate through the diff and the working directory, building a list of
+   actions to be taken (and sending notifications about conflicts and
+   dirty files).
+3. Remove any files / directories as needed (because alphabetical
+   iteration means that an untracked directory will end up sorted *after*
+   a blob that should be checked out with the same name).
+4. Update all blobs.
+5. Update all submodules (after 4 in case a new .gitmodules blob was
+   checked out)
+
+Checkout could be driven either off a target-to-workdir diff or a
+baseline-to-target diff.  There are pros and cons of each.
+
+Target-to-workdir means the diff includes every file that could be
+modified, which simplifies bookkeeping, but the code to constantly refer
+back to the baseline gets complicated.
+
+Baseline-to-target has simpler code because the diff defines the action to
+take, but needs special handling for untracked and ignored files, if they
+need to be removed.
+
+The current checkout implementation is based on a baseline-to-target diff.
+
+
+Picking Actions
+===============
+
+The most interesting aspect of this is phase 2, picking the actions that
+should be taken.  There are a lot of corner cases, so it may be easier to
+start by looking at the rules for a simple 2-iterator diff:
+
+Key
+---
+- B1,B2,B3 - blobs with different SHAs,
+- Bi       - ignored blob (WD only)
+- T1,T2,T3 - trees with different SHAs,
+- Ti       - ignored tree (WD only)
+- S1,S2    - submodules with different SHAs
+- Sd       - dirty submodule (WD only)
+- x        - nothing
+
+Diff with 2 non-workdir iterators
+---------------------------------
+
+|    | Old | New |                                                            |
+|----|-----|-----|------------------------------------------------------------|
+|  0 |   x |   x | nothing                                                    |
+|  1 |   x |  B1 | added blob                                                 |
+|  2 |   x |  T1 | added tree                                                 |
+|  3 |  B1 |   x | removed blob                                               |
+|  4 |  B1 |  B1 | unmodified blob                                            |
+|  5 |  B1 |  B2 | modified blob                                              |
+|  6 |  B1 |  T1 | typechange blob -> tree                                    |
+|  7 |  T1 |   x | removed tree                                               |
+|  8 |  T1 |  B1 | typechange tree -> blob                                    |
+|  9 |  T1 |  T1 | unmodified tree                                            |
+| 10 |  T1 |  T2 | modified tree (implies modified/added/removed blob inside) |
+
+
+Now, let's make the "New" iterator into a working directory iterator, so
+we replace "added" items with either untracked or ignored, like this:
+
+Diff with non-work & workdir iterators
+--------------------------------------
+
+|    | Old | New |                                                            |
+|----|-----|-----|------------------------------------------------------------|
+|  0 |  x  | x   | nothing                                                    |
+|  1 |  x  | B1  | untracked blob                                             |
+|  2 |  x  | Bi  | ignored file                                               |
+|  3 |  x  | T1  | untracked tree                                             |
+|  4 |  x  | Ti  | ignored tree                                               |
+|  5 | B1  | x   | removed blob                                               |
+|  6 | B1  | B1  | unmodified blob                                            |
+|  7 | B1  | B2  | modified blob                                              |
+|  8 | B1  | T1  | typechange blob -> tree                                    |
+|  9 | B1  | Ti  | removed blob AND ignored tree as separate items            |
+| 10 | T1  | x   | removed tree                                               |
+| 11 | T1  | B1  | typechange tree -> blob                                    |
+| 12 | T1  | Bi  | removed tree AND ignored blob as separate items            |
+| 13 | T1  | T1  | unmodified tree                                            |
+| 14 | T1  | T2  | modified tree (implies modified/added/removed blob inside) |
+
+Note: if there is a corresponding entry in the old tree, then a working
+directory item won't be ignored (i.e. no Bi or Ti for tracked items).
+
+
+Now, expand this to three iterators: a baseline tree, a target tree, and
+an actual working directory tree:
+
+Checkout From 3 Iterators (2 not workdir, 1 workdir)
+----------------------------------------------------
+
+(base == old HEAD; target == what to checkout; actual == working dir)
+
+|     |base | target | actual/workdir |                                                                    |
+|-----|-----|------- |----------------|--------------------------------------------------------------------|
+|  0  |   x |      x |      x         | nothing                                                            |
+|  1  |   x |      x | B1/Bi/T1/Ti    | untracked/ignored blob/tree (SAFE)                                 |
+|  2+ |   x |     B1 |      x         | add blob (SAFE)                                                    |
+|  3  |   x |     B1 |     B1         | independently added blob (FORCEABLE-2)                             |
+|  4* |   x |     B1 | B2/Bi/T1/Ti    | add blob with content conflict (FORCEABLE-2)                       |
+|  5+ |   x |     T1 |      x         | add tree (SAFE)                                                    |
+|  6* |   x |     T1 |  B1/Bi         | add tree with blob conflict (FORCEABLE-2)                          |
+|  7  |   x |     T1 |   T1/i         | independently added tree (SAFE+MISSING)                            |
+|  8  |  B1 |      x |      x         | independently deleted blob (SAFE+MISSING)                          |
+|  9- |  B1 |      x |     B1         | delete blob (SAFE)                                                 |
+| 10- |  B1 |      x |     B2         | delete of modified blob (FORCEABLE-1)                              |
+| 11  |  B1 |      x |  T1/Ti         | independently deleted blob AND untrack/ign tree (SAFE+MISSING !!!) |
+| 12  |  B1 |     B1 |      x         | locally deleted blob (DIRTY || SAFE+CREATE)                        |
+| 13+ |  B1 |     B2 |      x         | update to deleted blob (SAFE+MISSING)                              |
+| 14  |  B1 |     B1 |     B1         | unmodified file (SAFE)                                             |
+| 15  |  B1 |     B1 |     B2         | locally modified file (DIRTY)                                      |
+| 16+ |  B1 |     B2 |     B1         | update unmodified blob (SAFE)                                      |
+| 17  |  B1 |     B2 |     B2         | independently updated blob (FORCEABLE-1)                           |
+| 18+ |  B1 |     B2 |     B3         | update to modified blob (FORCEABLE-1)                              |
+| 19  |  B1 |     B1 |  T1/Ti         | locally deleted blob AND untrack/ign tree (DIRTY)                  |
+| 20* |  B1 |     B2 |  T1/Ti         | update to deleted blob AND untrack/ign tree (F-1)                  |
+| 21+ |  B1 |     T1 |      x         | add tree with locally deleted blob (SAFE+MISSING)                  |
+| 22* |  B1 |     T1 |     B1         | add tree AND deleted blob (SAFE)                                   |
+| 23* |  B1 |     T1 |     B2         | add tree with delete of modified blob (F-1)                        |
+| 24  |  B1 |     T1 |     T1         | add tree with deleted blob (F-1)                                   |
+| 25  |  T1 |      x |      x         | independently deleted tree (SAFE+MISSING)                          |
+| 26  |  T1 |      x |  B1/Bi         | independently deleted tree AND untrack/ign blob (F-1)              |
+| 27- |  T1 |      x |     T1         | deleted tree (MAYBE SAFE)                                          |
+| 28+ |  T1 |     B1 |      x         | deleted tree AND added blob (SAFE+MISSING)                         |
+| 29  |  T1 |     B1 |     B1         | independently typechanged tree -> blob (F-1)                       |
+| 30+ |  T1 |     B1 |     B2         | typechange tree->blob with conflicting blob (F-1)                  |
+| 31* |  T1 |     B1 |  T1/T2         | typechange tree->blob (MAYBE SAFE)                                 |
+| 32+ |  T1 |     T1 |      x         | restore locally deleted tree (SAFE+MISSING)                        |
+| 33  |  T1 |     T1 |  B1/Bi         | locally typechange tree->untrack/ign blob (DIRTY)                  |
+| 34  |  T1 |     T1 |  T1/T2         | unmodified tree (MAYBE SAFE)                                       |
+| 35+ |  T1 |     T2 |      x         | update locally deleted tree (SAFE+MISSING)                         |
+| 36* |  T1 |     T2 |  B1/Bi         | update to tree with typechanged tree->blob conflict (F-1)          |
+| 37  |  T1 |     T2 | T1/T2/T3       | update to existing tree (MAYBE SAFE)                               |
+| 38+ |   x |     S1 |      x         | add submodule (SAFE)                                               |
+| 39  |   x |     S1 |  S1/Sd         | independently added submodule (SUBMODULE)                          |
+| 40* |   x |     S1 |     B1         | add submodule with blob confilct (FORCEABLE)                       |
+| 41* |   x |     S1 |     T1         | add submodule with tree conflict (FORCEABLE)                       |
+| 42  |  S1 |      x |  S1/Sd         | deleted submodule (SUBMODULE)                                      |
+| 43  |  S1 |      x |      x         | independently deleted submodule (SUBMODULE)                        |
+| 44  |  S1 |      x |     B1         | independently deleted submodule with added blob (SAFE+MISSING)     |
+| 45  |  S1 |      x |     T1         | independently deleted submodule with added tree (SAFE+MISSING)     |
+| 46  |  S1 |     S1 |      x         | locally deleted submodule (SUBMODULE)                              |
+| 47+ |  S1 |     S2 |      x         | update locally deleted submodule (SAFE)                            |
+| 48  |  S1 |     S1 |     S2         | locally updated submodule commit (SUBMODULE)                       |
+| 49  |  S1 |     S2 |     S1         | updated submodule commit (SUBMODULE)                               |
+| 50+ |  S1 |     B1 |      x         | add blob with locally deleted submodule (SAFE+MISSING)             |
+| 51* |  S1 |     B1 |     S1         | typechange submodule->blob (SAFE)                                  |
+| 52* |  S1 |     B1 |     Sd         | typechange dirty submodule->blob (SAFE!?!?)                        |
+| 53+ |  S1 |     T1 |      x         | add tree with locally deleted submodule (SAFE+MISSING)             |
+| 54* |  S1 |     T1 |  S1/Sd         | typechange submodule->tree (MAYBE SAFE)                            |
+| 55+ |  B1 |     S1 |      x         | add submodule with locally deleted blob (SAFE+MISSING)             |
+| 56* |  B1 |     S1 |     B1         | typechange blob->submodule (SAFE)                                  |
+| 57+ |  T1 |     S1 |      x         | add submodule with locally deleted tree (SAFE+MISSING)             |
+| 58* |  T1 |     S1 |     T1         | typechange tree->submodule (SAFE)                                  |
+
+
+The number is followed by ' ' if no change is needed or '+' if the case
+needs to write to disk or '-' if something must be deleted and '*' if
+there should be a delete followed by an write.
+
+There are four tiers of safe cases:
+
+* SAFE         == completely safe to update
+* SAFE+MISSING == safe except the workdir is missing the expect content
+* MAYBE SAFE   == safe if workdir tree matches (or is missing) baseline
+                  content, which is unknown at this point
+* FORCEABLE == conflict unless FORCE is given
+* DIRTY     == no conflict but change is not applied unless FORCE
+* SUBMODULE == no conflict and no change is applied unless a deleted
+               submodule dir is empty
+
+Some slightly unusual circumstances:
+
+* 8 - parent dir is only deleted when file is, so parent will be left if
+    empty even though it would be deleted if the file were present
+* 11 - core git does not consider this a conflict but attempts to delete T1
+    and gives "unable to unlink file" error yet does not skip the rest
+    of the operation
+* 12 - without FORCE file is left deleted (i.e. not restored) so new wd is
+    dirty (and warning message "D file" is printed), with FORCE, file is
+    restored.
+* 24 - This should be considered MAYBE SAFE since effectively it is 7 and 8
+    combined, but core git considers this a conflict unless forced.
+* 26 - This combines two cases (1 & 25) (and also implied 8 for tree content)
+    which are ok on their own, but core git treat this as a conflict.
+    If not forced, this is a conflict.  If forced, this actually doesn't
+    have to write anything and leaves the new blob as an untracked file.
+* 32 - This is the only case where the baseline and target values match
+    and yet we will still write to the working directory.  In all other
+    cases, if baseline == target, we don't touch the workdir (it is
+    either already right or is "dirty").  However, since this case also
+    implies that a ?/B1/x case will exist as well, it can be skipped.
+* 41 - It's not clear how core git distinguishes this case from 39 (mode?).
+* 52 - Core git makes destructive changes without any warning when the
+    submodule is dirty and the type changes to a blob.
+
+Cases 3, 17, 24, 26, and 29 are all considered conflicts even though
+none of them will require making any updates to the working directory.

vendor/libgit2-sys/libgit2/docs/diff-internals.md

diff --git a/vendor/libgit2-sys/libgit2/docs/diff-internals.md b/vendor/libgit2-sys/libgit2/docs/diff-internals.md
new file mode 100644
index 0000000..da4c5a1
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/docs/diff-internals.md
@@ -0,0 +1,92 @@
+Diff is broken into four phases:
+
+1. Building a list of things that have changed.  These changes are called
+   deltas (git_diff_delta objects) and are grouped into a git_diff_list.
+2. Applying file similarity measurement for rename and copy detection (and
+   to potentially split files that have changed radically).  This step is
+   optional.
+3. Computing the textual diff for each delta.  Not all deltas have a
+   meaningful textual diff.  For those that do, the textual diff can
+   either be generated on the fly and passed to output callbacks or can be
+   turned into a git_diff_patch object.
+4. Formatting the diff and/or patch into standard text formats (such as
+   patches, raw lists, etc).
+
+In the source code, step 1 is implemented in `src/diff.c`, step 2 in
+`src/diff_tform.c`, step 3 in `src/diff_patch.c`, and step 4 in
+`src/diff_print.c`.  Additionally, when it comes to accessing file
+content, everything goes through diff drivers that are implemented in
+`src/diff_driver.c`.
+
+External Objects
+----------------
+
+* `git_diff_options` represents user choices about how a diff should be
+  performed and is passed to most diff generating functions.
+* `git_diff_file` represents an item on one side of a possible delta
+* `git_diff_delta` represents a pair of items that have changed in some
+  way - it contains two `git_diff_file` plus a status and other stuff.
+* `git_diff_list` is a list of deltas along with information about how
+  those particular deltas were found.
+* `git_diff_patch` represents the actual diff between a pair of items.  In
+  some cases, a delta may not have a corresponding patch, if the objects
+  are binary, for example.  The content of a patch will be a set of hunks
+  and lines.
+* A `hunk` is range of lines described by a `git_diff_range` (i.e.  "lines
+  10-20 in the old file became lines 12-23 in the new").  It will have a
+  header that compactly represents that information, and it will have a
+  number of lines of context surrounding added and deleted lines.
+* A `line` is simple a line of data along with a `git_diff_line_t` value
+  that tells how the data should be interpreted (e.g. context or added).
+
+Internal Objects
+----------------
+
+* `git_diff_file_content` is an internal structure that represents the
+  data on one side of an item to be diffed; it is an augmented
+  `git_diff_file` with more flags and the actual file data.
+
+    * it is created from a repository plus a) a git_diff_file, b) a git_blob,
+   or c) raw data and size
+    * there are three main operations on git_diff_file_content:
+    
+        * _initialization_ sets up the data structure and does what it can up to,
+          but not including loading and looking at the actual data
+        * _loading_ loads the data, preprocesses it (i.e. applies filters) and
+          potentially analyzes it (to decide if binary)
+        * _free_ releases loaded data and frees any allocated memory
+
+* The internal structure of a `git_diff_patch` stores the actual diff
+  between a pair of `git_diff_file_content` items
+
+    * it may be "unset" if the items are not diffable
+    * "empty" if the items are the same
+    * otherwise it will consist of a set of hunks each of which covers some
+      number of lines of context, additions and deletions
+    * a patch is created from two git_diff_file_content items
+    * a patch is fully instantiated in three phases:
+    
+        * initial creation and initialization
+        * loading of data and preliminary data examination
+        * diffing of data and optional storage of diffs
+    * (TBD) if a patch is asked to store the diffs and the size of the diff
+      is significantly smaller than the raw data of the two sides, then the
+      patch may be flattened using a pool of string data
+
+* `git_diff_output` is an internal structure that represents an output
+  target for a `git_diff_patch`
+    * It consists of file, hunk, and line callbacks, plus a payload
+    * There is a standard flattened output that can be used for plain text output
+    * Typically we use a `git_xdiff_output` which drives the callbacks via the
+      xdiff code taken from core Git.
+
+* `git_diff_driver` is an internal structure that encapsulates the logic
+  for a given type of file
+    * a driver is looked up based on the name and mode of a file.
+    * the driver can then be used to:
+        * determine if a file is binary (by attributes, by git_diff_options
+          settings, or by examining the content)
+        * give you a function pointer that is used to evaluate function context
+          for hunk headers
+    * At some point, the logic for getting a filtered version of file content
+      or calculating the OID of a file may be moved into the driver.

vendor/libgit2-sys/libgit2/docs/differences-from-git.md

diff --git a/vendor/libgit2-sys/libgit2/docs/differences-from-git.md b/vendor/libgit2-sys/libgit2/docs/differences-from-git.md
new file mode 100644
index 0000000..3f46508
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/docs/differences-from-git.md
@@ -0,0 +1,27 @@
+# Differences from Git
+
+In some instances, the functionality of libgit2 deviates slightly from Git. This can be because of technical limitations when developing a library, licensing limitations when converting functionality from Git to libgit2, or various other reasons.
+
+Repository and Workdir Path Reporting
+-------------------------------------
+
+When asking Git for the absolute path of a repository via `git rev-parse --absolute-git-dir`, it will output the path to the ".git" folder without a trailing slash. In contrast to that, the call `git_repository_path(repo)` will return the path with a trailing slash:
+
+```
+git rev-parse --absolute-git-dir -> /home/user/projects/libgit2/.git
+git_repository_path(repo) -> /home/user/projects/libgit2/.git/
+```
+
+The same difference exists when listing worktrees:
+
+```
+git worktree list -> /home/user/projects/libgit2
+git_repository_workdir(repo) -> /home/user/projects/libgit2/
+```
+
+Windows Junction Points
+-----------------------
+
+In libgit2, junction points are treated like symbolic links. They're handled specially in `git_win32__file_attribute_to_stat` in `src/win/w32_util.h`. This means that libgit2 tracks the directory itself as a link.
+
+In Git for Windows, junction points are treated like regular directories. This means that Git for Windows tracks the contents of the directory.

vendor/libgit2-sys/libgit2/docs/error-handling.md

diff --git a/vendor/libgit2-sys/libgit2/docs/error-handling.md b/vendor/libgit2-sys/libgit2/docs/error-handling.md
new file mode 100644
index 0000000..719244d
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/docs/error-handling.md
@@ -0,0 +1,270 @@
+Error reporting in libgit2
+==========================
+
+Libgit2 tries to follow the POSIX style: functions return an `int` value
+with 0 (zero) indicating success and negative values indicating an error.
+There are specific negative error codes for each "expected failure"
+(e.g. `GIT_ENOTFOUND` for files that take a path which might be missing)
+and a generic error code (-1) for all critical or non-specific failures
+(e.g. running out of memory or system corruption).
+
+When a negative value is returned, an error message is also set.  The
+message can be accessed via the `giterr_last` function which will return a
+pointer to a `git_error` structure containing the error message text and
+the class of error (i.e. what part of the library generated the error).
+
+For instance: An object lookup by SHA prefix (`git_object_lookup_prefix`)
+has two expected failure cases: the SHA is not found at all which returns
+`GIT_ENOTFOUND` or the SHA prefix is ambiguous (i.e. two or more objects
+share the prefix) which returns `GIT_EAMBIGUOUS`.  There are any number of
+critical failures (such as a packfile being corrupted, a loose object
+having the wrong access permissions, etc.) all of which will return -1.
+When the object lookup is successful, it will return 0.
+
+If libgit2 was compiled with threads enabled (`-DTHREADSAFE=ON` when using
+CMake), then the error message will be kept in thread-local storage, so it
+will not be modified by other threads.  If threads are not enabled, then
+the error message is in global data.
+
+All of the error return codes, the `git_error` type, the error access
+functions, and the error classes are defined in `include/git2/errors.h`.
+See the documentation there for details on the APIs for accessing,
+clearing, and even setting error codes.
+
+When writing libgit2 code, please be smart and conservative when returning
+error codes.  Functions usually have a maximum of two or three "expected
+errors" and in most cases only one.  If you feel there are more possible
+expected error scenarios, then the API you are writing may be at too high
+a level for core libgit2.
+
+Example usage
+-------------
+
+When using libgit2, you will typically capture the return value from
+functions using an `int` variable and check to see if it is negative.
+When that happens, you can, if you wish, look at the specific value or
+look at the error message that was generated.
+
+~~~c
+{
+	git_repository *repo;
+	int error = git_repository_open(&repo, "path/to/repo");
+
+	if (error < 0) {
+		fprintf(stderr, "Could not open repository: %s\n", giterr_last()->message);
+		exit(1);
+	}
+
+	... use `repo` here ...
+
+	git_repository_free(repo); /* void function - no error return code */
+}
+~~~
+
+Some of the error return values do have meaning.  Optionally, you can look
+at the specific error values to decide what to do.
+
+~~~c
+{
+	git_repository *repo;
+	const char *path = "path/to/repo";
+	int error = git_repository_open(&repo, path);
+
+	if (error < 0) {
+		if (error == GIT_ENOTFOUND)
+			fprintf(stderr, "Could not find repository at path '%s'\n", path);
+		else
+			fprintf(stderr, "Unable to open repository: %s\n",
+				giterr_last()->message);
+		exit(1);
+	}
+
+	... happy ...
+}
+~~~
+
+Some of the higher-level language bindings may use a range of information
+from libgit2 to convert error return codes into exceptions, including the
+specific error return codes and even the class of error and the error
+message returned by `giterr_last`, but the full range of that logic is
+beyond the scope of this document.
+
+Example internal implementation
+-------------------------------
+
+Internally, libgit2 detects error scenarios, records error messages, and
+returns error values.  Errors from low-level functions are generally
+passed upwards (unless the higher level can either handle the error or
+wants to translate the error into something more meaningful).
+
+~~~c
+int git_repository_open(git_repository **repository, const char *path)
+{
+	/* perform some logic to open the repository */
+	if (p_exists(path) < 0) {
+		giterr_set(GITERR_REPOSITORY, "The path '%s' doesn't exist", path);
+		return GIT_ENOTFOUND;
+	}
+
+	...
+}
+~~~
+
+The public error API
+--------------------
+
+- `const git_error *giterr_last(void)`: The main function used to look up
+  the last error.  This may return NULL if no error has occurred.
+  Otherwise this should return a `git_error` object indicating the class
+  of error and the error message that was generated by the library.
+
+  The last error is stored in thread-local storage when libgit2 is
+  compiled with thread support, so you do not have to worry about another
+  thread overwriting the value.  When thread support is off, the last
+  error is a global value.
+
+  _Note_ There are some known bugs in the library where this may return
+  NULL even when an error code was generated.  Please report these as
+  bugs, but in the meantime, please code defensively and check for NULL
+  when calling this function.
+
+- `void giterr_clear(void)`: This function clears the last error.  The
+  library will call this when an error is generated by low level function
+  and the higher level function handles the error.
+
+  _Note_ There are some known bugs in the library where a low level
+  function's error message is not cleared by higher level code that
+  handles the error and returns zero.  Please report these as bugs, but in
+  the meantime, a zero return value from a libgit2 API does not guarantee
+  that `giterr_last()` will return NULL.
+
+- `void giterr_set_str(int error_class, const char *message)`: This
+  function can be used when writing a custom backend module to set the
+  libgit2 error message.  See the documentation on this function for its
+  use.  Normal usage of libgit2 will probably never need to call this API.
+
+- `void giterr_set_oom(void)`: This is a standard function for reporting
+  an out-of-memory error.  It is written in a manner that it doesn't have
+  to allocate any extra memory in order to record the error, so this is
+  the best way to report that scenario.
+
+Deviations from the standard
+----------------------------
+
+There are some public functions that do not return `int` values.  There
+are two primary cases:
+
+* `void` return values: If a function has a `void` return, then it will
+  never fail.  This primary will be used for object destructors.
+
+* `git_xyz *` return values: These are simple accessor functions where the
+  only meaningful error would typically be looking something up by index
+  and having the index be out of bounds.  In those cases, the function
+  will typically return NULL.
+
+* Boolean return values: There are some cases where a function cannot fail
+  and wants to return a boolean value.  In those cases, we try to return 1
+  for true and 0 for false.  These cases are rare and the return value for
+  the function should probably be an `unsigned int` to denote these cases.
+  If you find an exception, please open an issue and let's fix it.
+
+There are a few other exceptions to these rules here and there in the
+library, but those are extremely rare and should probably be converted
+over to other to more standard patterns for usage.  Feel free to open
+issues pointing these out.
+
+There are some known bugs in the library where some functions may return a
+negative value but not set an error message and some other functions may
+return zero (no error) and yet leave an error message set.  Please report
+these cases as issues and they will be fixed.  In the meanwhile, please
+code defensively, checking that the return value of `giterr_last` is not
+NULL before using it, and not relying on `giterr_last` to return NULL when
+a function returns 0 for success.
+
+The internal error API
+----------------------
+
+- `void giterr_set(int error_class, const char *fmt, ...)`: This is the
+  main internal function for setting an error.  It works like `printf` to
+  format the error message.  See the notes of `giterr_set_str` for a
+  general description of how error messages are stored (and also about
+  special handling for `error_class` of `GITERR_OS`).
+
+Writing error messages
+----------------------
+
+Here are some guidelines when writing error messages:
+
+- Use proper English, and an impersonal or past tenses: *The given path
+  does not exist*, *Failed to lookup object in ODB*
+
+- Use short, direct and objective messages. **One line, max**. libgit2 is
+  a low level library: think that all the messages reported will be thrown
+  as Ruby or Python exceptions. Think how long are common exception
+  messages in those languages.
+
+- **Do not add redundant information to the error message**, specially
+  information that can be inferred from the context.
+
+	E.g. in `git_repository_open`, do not report a message like "Failed to
+	open repository: path not found". Somebody is calling that
+	function. If it fails, they already know that the repository failed to
+	open!
+
+General guidelines for error reporting
+--------------------------------------
+
+- Libgit2 does not handle programming errors with these
+  functions. Programming errors are `assert`ed, and when their source is
+  internal, fixed as soon as possible. This is C, people.
+
+	Example of programming errors that would **not** be handled: passing
+    NULL to a function that expects a valid pointer; passing a `git_tree`
+    to a function that expects a `git_commit`. All these cases need to be
+    identified with `assert` and fixed asap.
+
+	Example of a runtime error: failing to parse a `git_tree` because it
+    contains invalid data. Failing to open a file because it doesn't exist
+    on disk. These errors are handled, a meaningful error message is set,
+    and an error code is returned.
+
+- In general, *do not* try to overwrite errors internally and *do*
+  propagate error codes from lower level functions to the higher level.
+  There are some cases where propagating an error code will be more
+  confusing rather than less, so there are some exceptions to this rule,
+  but the default behavior should be to simply clean up and pass the error
+  on up to the caller.
+
+    **WRONG**
+
+	~~~c
+	int git_commit_parent(...)
+	{
+		...
+
+		if (git_commit_lookup(parent, repo, parent_id) < 0) {
+			giterr_set(GITERR_COMMIT, "Overwrite lookup error message");
+			return -1; /* mask error code */
+		}
+
+		...
+	}
+	~~~
+
+	**RIGHT**
+
+	~~~c
+	int git_commit_parent(...)
+	{
+		...
+
+		error = git_commit_lookup(parent, repo, parent_id);
+		if (error < 0) {
+			/* cleanup intermediate objects if necessary */
+			/* leave error message and propagate error code */
+			return error;
+		}
+
+		...
+	}
+	~~~

vendor/libgit2-sys/libgit2/docs/merge-df_conflicts.txt

diff --git a/vendor/libgit2-sys/libgit2/docs/merge-df_conflicts.txt b/vendor/libgit2-sys/libgit2/docs/merge-df_conflicts.txt
new file mode 100644
index 0000000..09780ee
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/docs/merge-df_conflicts.txt
@@ -0,0 +1,41 @@
+Anc / Our / Thr represent the ancestor / ours / theirs side of a merge
+from branch "branch" into HEAD.  Workdir represents the expected files in
+the working directory.  Index represents the expected files in the index,
+with stage markers.
+
+    Anc  Our  Thr    Workdir             Index
+1   D    D
+               D/F   D/F                 D/F [0]
+
+2   D    D+          D~HEAD (mod/del)    D/F [0]
+               D/F   D/F                 D [1]
+                                         D [2]
+
+3   D          D     D/F                 D/F [0]
+         D/F
+
+4   D          D+    D~branch (mod/del)  D/F [0]
+         D/F         D/F                 D [1]
+                                         D [3]
+
+5   D                D/F (add/add)       D/F [2]
+         D/F                             D/F [3]
+               D/F
+
+6   D/F  D/F         D                   D [0]
+               D
+
+7   D/F  D/F+        D/F (mod/del)       D/F [1]
+               D     D~branch (fil/dir)  D/F [2]
+                                         D [3]
+
+8   D/F        D/F   D                   D [0]
+         D
+
+9   D/F        D/F+  D/F (mod/del)       D/F [1]
+         D           D~HEAD (fil/dir)    D [2]
+                                         D/F [3]
+
+10  D/F              D/F (fil/dir)       D/F [0]
+         D           D~HEAD              D [2]
+               D

vendor/libgit2-sys/libgit2/docs/release.md

diff --git a/vendor/libgit2-sys/libgit2/docs/release.md b/vendor/libgit2-sys/libgit2/docs/release.md
new file mode 100644
index 0000000..42f032b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/docs/release.md
@@ -0,0 +1,81 @@
+# Releasing the library
+
+We have three kinds of releases: "full" releases, maintenance releases and security releases. Full ones release the state of the `master` branch whereas maintenance releases provide bugfixes building on top of the currently released series. Security releases are also for the current series but only contain security fixes on top of the previous release.
+
+## Full release
+
+We aim to release once every six months. We start the process by opening an issue. This is accompanied with a feature freeze. From now until the release, only bug fixes are to be merged. Use the following as a base for the issue
+
+    Release v0.X
+    
+    Let's release v0.X, codenamed: <something witty>
+    
+    - [ ] Bump the versions in the headers
+    - [ ] Make a release candidate
+    - [ ] Plug any final leaks
+    - [ ] Fix any last-minute issues
+    - [ ] Make sure CHANGELOG reflects everything worth discussing
+    - [ ] Update the version in CHANGELOG and the header
+    - [ ] Produce a release candidate
+    - [ ] Tag
+    - [ ] Create maint/v0.X
+    - [ ] Update any bindings the core team works with
+
+We tag at least one release candidate. This RC must carry the new version in the headers, including the SOVERSION. If there are no significant issues found, we can go straight to the release after a single RC. This is up to the discretion of the release manager. There is no set time to have the candidate out, but we should we should give downstream projects at least a week to give feedback.
+
+Preparing the first release candidate includes updating the version number of libgit2 to the new version number. To do so, a pull request shall be submitted that adjusts the version number in the following places:
+
+- CHANGELOG.md
+- include/git2/version.h
+
+As soon as the pull request is merged, the merge commit shall be tagged with a lightweight tag.
+
+The tagging happens via GitHub's "releases" tab which lets us attach release notes to a particular tag. In the description we include the changes in `CHANGELOG.md` between the last full release. Use the following as a base for the release notes
+
+    This is the first release of the v0.X series, <codename>. The changelog follows.
+
+followed by the three sections in the changelog. For release candidates we can avoid copying the full changelog and only include any new entries.
+
+During the freeze, and certainly after the first release candidate, any bindings the core team work with should be updated in order to discover any issues that might come up with the multitude of approaches to memory management, embedding or linking.
+
+Create a branch `maint/v0.X` at the current state of `master` after you've created the tag. This will be used for maintenance releases and lets our dependents track the latest state of the series.
+
+## Maintenance release
+
+Every once in a while, when we feel we've accumulated a significant amount of backportable fixes in the mainline branch, we produce a maintenance release in order to provide fixes or improvements for those who track the releases. This also lets our users and integrators receive updates without having to upgrade to the next full release.
+
+As a rule of thumb, it's a good idea to produce a maintenance release for the current series when we're getting ready for a full release. This gives the (still) current series a last round of fixes without having to upgrade (which with us potentially means adjusting to API changes).
+
+Start by opening an issue. Use the following as a base.
+
+    Release v0.X.Y
+    
+    Enough fixes have accumulated, let's release v0.X.Y
+    
+    - [ ] Select the changes we want to backport
+    - [ ] Update maint/v0.X
+    - [ ] Tag
+
+The list of changes to backport does not need to be comprehensive and we might not backport something if the code in mainline has diverged significantly. These fixes do not include those which require API or ABI changes as we release under the same SOVERSION.
+
+Do not merge into the `maint/v0.X` until we are getting ready to produce a new release. There is always the possibility that we will need to produce a security release and those must only include the relevant security fixes and not arbitrary fixes we were planning on releasing at some point.
+
+Here we do not use release candidates as the changes are supposed to be small and proven.
+
+## Security releases
+
+This is the same as a maintenance release, except that the fix itself will most likely be developed in a private repository and will only be visible to a select group of people until the release.
+
+Everything else remains the same. Occasionally we might opt to backport a security fix to the previous series, based on how recently we started the new series and how serious the issue is.
+
+## Updating documentation
+
+We use docurium to generate our documentation. It is a tool written in ruby which leverages libclang's documentation parser. Install docurium
+
+    gem install docurium
+
+and run it against our description file with the tip of master checked out.
+
+    cm doc api.docurium
+
+It will start up a few proceses and write out the results as a new commit onto the `gh-pages` branch. That can be pushed to GitHub to update what will show up on our documentation reference site.

vendor/libgit2-sys/libgit2/examples/CMakeLists.txt

diff --git a/vendor/libgit2-sys/libgit2/examples/CMakeLists.txt b/vendor/libgit2-sys/libgit2/examples/CMakeLists.txt
new file mode 100644
index 0000000..ca7515e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/CMakeLists.txt
@@ -0,0 +1,18 @@
+INCLUDE_DIRECTORIES(${LIBGIT2_INCLUDES})
+
+FILE(GLOB_RECURSE SRC_EXAMPLE_GIT2 network/*.c network/*.h common.?)
+ADD_EXECUTABLE(cgit2 ${SRC_EXAMPLE_GIT2})
+IF(WIN32 OR ANDROID)
+	TARGET_LINK_LIBRARIES(cgit2 git2)
+ELSE()
+	TARGET_LINK_LIBRARIES(cgit2 git2 pthread)
+ENDIF()
+
+FILE(GLOB SRC_EXAMPLE_APPS RELATIVE ${CMAKE_CURRENT_SOURCE_DIR} *.c)
+FOREACH(src_app ${SRC_EXAMPLE_APPS})
+	STRING(REPLACE ".c" "" app_name ${src_app})
+	IF(NOT ${app_name} STREQUAL "common")
+		ADD_EXECUTABLE(${app_name} ${src_app} "common.c")
+		TARGET_LINK_LIBRARIES(${app_name} git2)
+	ENDIF()
+ENDFOREACH()

vendor/libgit2-sys/libgit2/examples/COPYING

diff --git a/vendor/libgit2-sys/libgit2/examples/COPYING b/vendor/libgit2-sys/libgit2/examples/COPYING
new file mode 100644
index 0000000..0e259d4
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/COPYING
@@ -0,0 +1,121 @@
+Creative Commons Legal Code
+
+CC0 1.0 Universal
+
+    CREATIVE COMMONS CORPORATION IS NOT A LAW FIRM AND DOES NOT PROVIDE
+    LEGAL SERVICES. DISTRIBUTION OF THIS DOCUMENT DOES NOT CREATE AN
+    ATTORNEY-CLIENT RELATIONSHIP. CREATIVE COMMONS PROVIDES THIS
+    INFORMATION ON AN "AS-IS" BASIS. CREATIVE COMMONS MAKES NO WARRANTIES
+    REGARDING THE USE OF THIS DOCUMENT OR THE INFORMATION OR WORKS
+    PROVIDED HEREUNDER, AND DISCLAIMS LIABILITY FOR DAMAGES RESULTING FROM
+    THE USE OF THIS DOCUMENT OR THE INFORMATION OR WORKS PROVIDED
+    HEREUNDER.
+
+Statement of Purpose
+
+The laws of most jurisdictions throughout the world automatically confer
+exclusive Copyright and Related Rights (defined below) upon the creator
+and subsequent owner(s) (each and all, an "owner") of an original work of
+authorship and/or a database (each, a "Work").
+
+Certain owners wish to permanently relinquish those rights to a Work for
+the purpose of contributing to a commons of creative, cultural and
+scientific works ("Commons") that the public can reliably and without fear
+of later claims of infringement build upon, modify, incorporate in other
+works, reuse and redistribute as freely as possible in any form whatsoever
+and for any purposes, including without limitation commercial purposes.
+These owners may contribute to the Commons to promote the ideal of a free
+culture and the further production of creative, cultural and scientific
+works, or to gain reputation or greater distribution for their Work in
+part through the use and efforts of others.
+
+For these and/or other purposes and motivations, and without any
+expectation of additional consideration or compensation, the person
+associating CC0 with a Work (the "Affirmer"), to the extent that he or she
+is an owner of Copyright and Related Rights in the Work, voluntarily
+elects to apply CC0 to the Work and publicly distribute the Work under its
+terms, with knowledge of his or her Copyright and Related Rights in the
+Work and the meaning and intended legal effect of CC0 on those rights.
+
+1. Copyright and Related Rights. A Work made available under CC0 may be
+protected by copyright and related or neighboring rights ("Copyright and
+Related Rights"). Copyright and Related Rights include, but are not
+limited to, the following:
+
+  i. the right to reproduce, adapt, distribute, perform, display,
+     communicate, and translate a Work;
+ ii. moral rights retained by the original author(s) and/or performer(s);
+iii. publicity and privacy rights pertaining to a person's image or
+     likeness depicted in a Work;
+ iv. rights protecting against unfair competition in regards to a Work,
+     subject to the limitations in paragraph 4(a), below;
+  v. rights protecting the extraction, dissemination, use and reuse of data
+     in a Work;
+ vi. database rights (such as those arising under Directive 96/9/EC of the
+     European Parliament and of the Council of 11 March 1996 on the legal
+     protection of databases, and under any national implementation
+     thereof, including any amended or successor version of such
+     directive); and
+vii. other similar, equivalent or corresponding rights throughout the
+     world based on applicable law or treaty, and any national
+     implementations thereof.
+
+2. Waiver. To the greatest extent permitted by, but not in contravention
+of, applicable law, Affirmer hereby overtly, fully, permanently,
+irrevocably and unconditionally waives, abandons, and surrenders all of
+Affirmer's Copyright and Related Rights and associated claims and causes
+of action, whether now known or unknown (including existing as well as
+future claims and causes of action), in the Work (i) in all territories
+worldwide, (ii) for the maximum duration provided by applicable law or
+treaty (including future time extensions), (iii) in any current or future
+medium and for any number of copies, and (iv) for any purpose whatsoever,
+including without limitation commercial, advertising or promotional
+purposes (the "Waiver"). Affirmer makes the Waiver for the benefit of each
+member of the public at large and to the detriment of Affirmer's heirs and
+successors, fully intending that such Waiver shall not be subject to
+revocation, rescission, cancellation, termination, or any other legal or
+equitable action to disrupt the quiet enjoyment of the Work by the public
+as contemplated by Affirmer's express Statement of Purpose.
+
+3. Public License Fallback. Should any part of the Waiver for any reason
+be judged legally invalid or ineffective under applicable law, then the
+Waiver shall be preserved to the maximum extent permitted taking into
+account Affirmer's express Statement of Purpose. In addition, to the
+extent the Waiver is so judged Affirmer hereby grants to each affected
+person a royalty-free, non transferable, non sublicensable, non exclusive,
+irrevocable and unconditional license to exercise Affirmer's Copyright and
+Related Rights in the Work (i) in all territories worldwide, (ii) for the
+maximum duration provided by applicable law or treaty (including future
+time extensions), (iii) in any current or future medium and for any number
+of copies, and (iv) for any purpose whatsoever, including without
+limitation commercial, advertising or promotional purposes (the
+"License"). The License shall be deemed effective as of the date CC0 was
+applied by Affirmer to the Work. Should any part of the License for any
+reason be judged legally invalid or ineffective under applicable law, such
+partial invalidity or ineffectiveness shall not invalidate the remainder
+of the License, and in such case Affirmer hereby affirms that he or she
+will not (i) exercise any of his or her remaining Copyright and Related
+Rights in the Work or (ii) assert any associated claims and causes of
+action with respect to the Work, in either case contrary to Affirmer's
+express Statement of Purpose.
+
+4. Limitations and Disclaimers.
+
+ a. No trademark or patent rights held by Affirmer are waived, abandoned,
+    surrendered, licensed or otherwise affected by this document.
+ b. Affirmer offers the Work as-is and makes no representations or
+    warranties of any kind concerning the Work, express, implied,
+    statutory or otherwise, including without limitation warranties of
+    title, merchantability, fitness for a particular purpose, non
+    infringement, or the absence of latent or other defects, accuracy, or
+    the present or absence of errors, whether or not discoverable, all to
+    the greatest extent permissible under applicable law.
+ c. Affirmer disclaims responsibility for clearing rights of other persons
+    that may apply to the Work or any use thereof, including without
+    limitation any person's Copyright and Related Rights in the Work.
+    Further, Affirmer disclaims responsibility for obtaining any necessary
+    consents, permissions or other rights required for any use of the
+    Work.
+ d. Affirmer understands and acknowledges that Creative Commons is not a
+    party to this document and has no duty or obligation with respect to
+    this CC0 or use of the Work.

vendor/libgit2-sys/libgit2/examples/README.md

diff --git a/vendor/libgit2-sys/libgit2/examples/README.md b/vendor/libgit2-sys/libgit2/examples/README.md
new file mode 100644
index 0000000..769c4b2
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/README.md
@@ -0,0 +1,22 @@
+libgit2 examples
+================
+
+These examples are a mixture of basic emulation of core Git command line
+functions and simple snippets demonstrating libgit2 API usage (for use
+with Docurium).  As a whole, they are not vetted carefully for bugs, error
+handling, and cross-platform compatibility in the same manner as the rest
+of the code in libgit2, so copy with caution.
+
+That being said, you are welcome to copy code from these examples as
+desired when using libgit2. They have been [released to the public domain][cc0],
+so there are no restrictions on their use.
+
+[cc0]: COPYING
+
+For annotated HTML versions, see the "Examples" section of:
+
+    http://libgit2.github.com/libgit2
+
+such as:
+
+    http://libgit2.github.com/libgit2/ex/HEAD/general.html

vendor/libgit2-sys/libgit2/examples/add.c

diff --git a/vendor/libgit2-sys/libgit2/examples/add.c b/vendor/libgit2-sys/libgit2/examples/add.c
new file mode 100644
index 0000000..e584989
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/add.c
@@ -0,0 +1,158 @@
+/*
+ * libgit2 "add" example - shows how to modify the index
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include "common.h"
+#include <assert.h>
+
+enum print_options {
+	SKIP = 1,
+	VERBOSE = 2,
+	UPDATE = 4,
+};
+
+struct print_payload {
+	enum print_options options;
+	git_repository *repo;
+};
+
+/* Forward declarations for helpers */
+static void parse_opts(int *options, int *count, int argc, char *argv[]);
+void init_array(git_strarray *array, int argc, char **argv);
+int print_matched_cb(const char *path, const char *matched_pathspec, void *payload);
+
+int main (int argc, char** argv)
+{
+	git_index_matched_path_cb matched_cb = NULL;
+	git_repository *repo = NULL;
+	git_index *index;
+	git_strarray array = {0};
+	int options = 0, count = 0;
+	struct print_payload payload = {0};
+
+	git_libgit2_init();
+
+	parse_opts(&options, &count, argc, argv);
+
+	init_array(&array, argc-count, argv+count);
+
+	check_lg2(git_repository_open(&repo, "."), "No git repository", NULL);
+	check_lg2(git_repository_index(&index, repo), "Could not open repository index", NULL);
+
+	if (options&VERBOSE || options&SKIP) {
+		matched_cb = &print_matched_cb;
+	}
+
+	payload.options = options;
+	payload.repo = repo;
+
+	if (options&UPDATE) {
+		git_index_update_all(index, &array, matched_cb, &payload);
+	} else {
+		git_index_add_all(index, &array, 0, matched_cb, &payload);
+	}
+
+	git_index_write(index);
+	git_index_free(index);
+	git_repository_free(repo);
+
+	git_libgit2_shutdown();
+
+	return 0;
+}
+
+int print_matched_cb(const char *path, const char *matched_pathspec, void *payload)
+{
+	struct print_payload p = *(struct print_payload*)(payload);
+	int ret;
+	unsigned status;
+	(void)matched_pathspec;
+
+	if (git_status_file(&status, p.repo, path)) {
+		return -1;
+	}
+
+	if (status & GIT_STATUS_WT_MODIFIED || status & GIT_STATUS_WT_NEW) {
+		printf("add '%s'\n", path);
+		ret = 0;
+	} else {
+		ret = 1;
+	}
+
+	if(p.options & SKIP) {
+		ret = 1;
+	}
+
+	return ret;
+}
+
+void init_array(git_strarray *array, int argc, char **argv)
+{
+	unsigned int i;
+
+	array->count = argc;
+	array->strings = malloc(sizeof(char*) * array->count);
+	assert(array->strings!=NULL);
+
+	for(i=0; i<array->count; i++) {
+		array->strings[i]=argv[i];
+	}
+
+	return;
+}
+
+void print_usage(void)
+{
+	fprintf(stderr, "usage: add [options] [--] file-spec [file-spec] [...]\n\n");
+	fprintf(stderr, "\t-n, --dry-run    dry run\n");
+	fprintf(stderr, "\t-v, --verbose    be verbose\n");
+	fprintf(stderr, "\t-u, --update     update tracked files\n");
+	exit(1);
+}
+
+static void parse_opts(int *options, int *count, int argc, char *argv[])
+{
+	int i;
+
+	for (i = 1; i < argc; ++i) {
+		if (argv[i][0] != '-') {
+			break;
+		}
+		else if(!strcmp(argv[i], "--verbose") || !strcmp(argv[i], "-v")) {
+			*options |= VERBOSE;
+		}
+		else if(!strcmp(argv[i], "--dry-run") || !strcmp(argv[i], "-n")) {
+			*options |= SKIP;
+		}
+		else if(!strcmp(argv[i], "--update") || !strcmp(argv[i], "-u")) {
+			*options |= UPDATE;
+		}
+		else if(!strcmp(argv[i], "-h")) {
+			print_usage();
+			break;
+		}
+		else if(!strcmp(argv[i], "--")) {
+			i++;
+			break;
+		}
+		else {
+			fprintf(stderr, "Unsupported option %s.\n", argv[i]);
+			print_usage();
+		}
+	}
+
+	if (argc<=i)
+		print_usage();
+
+	*count = i;
+}

vendor/libgit2-sys/libgit2/examples/blame.c

diff --git a/vendor/libgit2-sys/libgit2/examples/blame.c b/vendor/libgit2-sys/libgit2/examples/blame.c
new file mode 100644
index 0000000..9288352
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/blame.c
@@ -0,0 +1,212 @@
+/*
+ * libgit2 "blame" example - shows how to use the blame API
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include "common.h"
+
+#ifdef _MSC_VER
+#define snprintf sprintf_s
+#define strcasecmp strcmpi
+#endif
+
+/**
+ * This example demonstrates how to invoke the libgit2 blame API to roughly
+ * simulate the output of `git blame` and a few of its command line arguments.
+ */
+
+struct opts {
+	char *path;
+	char *commitspec;
+	int C;
+	int M;
+	int start_line;
+	int end_line;
+	int F;
+};
+static void parse_opts(struct opts *o, int argc, char *argv[]);
+
+int main(int argc, char *argv[])
+{
+	int line, break_on_null_hunk;
+	size_t i, rawsize;
+	char spec[1024] = {0};
+	struct opts o = {0};
+	const char *rawdata;
+	git_repository *repo = NULL;
+	git_revspec revspec = {0};
+	git_blame_options blameopts = GIT_BLAME_OPTIONS_INIT;
+	git_blame *blame = NULL;
+	git_blob *blob;
+	git_object *obj;
+
+	git_libgit2_init();
+
+	parse_opts(&o, argc, argv);
+	if (o.M) blameopts.flags |= GIT_BLAME_TRACK_COPIES_SAME_COMMIT_MOVES;
+	if (o.C) blameopts.flags |= GIT_BLAME_TRACK_COPIES_SAME_COMMIT_COPIES;
+	if (o.F) blameopts.flags |= GIT_BLAME_FIRST_PARENT;
+
+	/** Open the repository. */
+	check_lg2(git_repository_open_ext(&repo, ".", 0, NULL), "Couldn't open repository", NULL);
+
+	/**
+	 * The commit range comes in "commitish" form. Use the rev-parse API to
+	 * nail down the end points.
+	 */
+	if (o.commitspec) {
+		check_lg2(git_revparse(&revspec, repo, o.commitspec), "Couldn't parse commit spec", NULL);
+		if (revspec.flags & GIT_REVPARSE_SINGLE) {
+			git_oid_cpy(&blameopts.newest_commit, git_object_id(revspec.from));
+			git_object_free(revspec.from);
+		} else {
+			git_oid_cpy(&blameopts.oldest_commit, git_object_id(revspec.from));
+			git_oid_cpy(&blameopts.newest_commit, git_object_id(revspec.to));
+			git_object_free(revspec.from);
+			git_object_free(revspec.to);
+		}
+	}
+
+	/** Run the blame. */
+	check_lg2(git_blame_file(&blame, repo, o.path, &blameopts), "Blame error", NULL);
+
+	/**
+	 * Get the raw data inside the blob for output. We use the
+	 * `commitish:path/to/file.txt` format to find it.
+	 */
+	if (git_oid_iszero(&blameopts.newest_commit))
+		strcpy(spec, "HEAD");
+	else
+		git_oid_tostr(spec, sizeof(spec), &blameopts.newest_commit);
+	strcat(spec, ":");
+	strcat(spec, o.path);
+
+	check_lg2(git_revparse_single(&obj, repo, spec), "Object lookup error", NULL);
+	check_lg2(git_blob_lookup(&blob, repo, git_object_id(obj)), "Blob lookup error", NULL);
+	git_object_free(obj);
+
+	rawdata = git_blob_rawcontent(blob);
+	rawsize = git_blob_rawsize(blob);
+
+	/** Produce the output. */
+	line = 1;
+	i = 0;
+	break_on_null_hunk = 0;
+	while (i < rawsize) {
+		const char *eol = memchr(rawdata + i, '\n', rawsize - i);
+		char oid[10] = {0};
+		const git_blame_hunk *hunk = git_blame_get_hunk_byline(blame, line);
+
+		if (break_on_null_hunk && !hunk)
+			break;
+
+		if (hunk) {
+			char sig[128] = {0};
+			break_on_null_hunk = 1;
+			
+			git_oid_tostr(oid, 10, &hunk->final_commit_id);
+			snprintf(sig, 30, "%s <%s>", hunk->final_signature->name, hunk->final_signature->email);
+
+			printf("%s ( %-30s %3d) %.*s\n",
+					oid,
+					sig,
+					line,
+					(int)(eol - rawdata - i),
+					rawdata + i);
+		}
+
+		i = (int)(eol - rawdata + 1);
+		line++;
+	}
+
+	/** Cleanup. */
+	git_blob_free(blob);
+	git_blame_free(blame);
+	git_repository_free(repo);
+
+	git_libgit2_shutdown();
+
+	return 0;
+}
+
+/** Tell the user how to make this thing work. */
+static void usage(const char *msg, const char *arg)
+{
+	if (msg && arg)
+		fprintf(stderr, "%s: %s\n", msg, arg);
+	else if (msg)
+		fprintf(stderr, "%s\n", msg);
+	fprintf(stderr, "usage: blame [options] [<commit range>] <path>\n");
+	fprintf(stderr, "\n");
+	fprintf(stderr, "   <commit range>      example: `HEAD~10..HEAD`, or `1234abcd`\n");
+	fprintf(stderr, "   -L <n,m>            process only line range n-m, counting from 1\n");
+	fprintf(stderr, "   -M                  find line moves within and across files\n");
+	fprintf(stderr, "   -C                  find line copies within and across files\n");
+	fprintf(stderr, "   -F                  follow only the first parent commits\n");
+	fprintf(stderr, "\n");
+	exit(1);
+}
+
+/** Parse the arguments. */
+static void parse_opts(struct opts *o, int argc, char *argv[])
+{
+	int i;
+	char *bare_args[3] = {0};
+
+	if (argc < 2) usage(NULL, NULL);
+
+	for (i=1; i<argc; i++) {
+		char *a = argv[i];
+
+		if (a[0] != '-') {
+			int i=0;
+			while (bare_args[i] && i < 3) ++i;
+			if (i >= 3)
+				usage("Invalid argument set", NULL);
+			bare_args[i] = a;
+		}
+		else if (!strcmp(a, "--"))
+			continue;
+		else if (!strcasecmp(a, "-M"))
+			o->M = 1;
+		else if (!strcasecmp(a, "-C"))
+			o->C = 1;
+		else if (!strcasecmp(a, "-F"))
+			o->F = 1;
+		else if (!strcasecmp(a, "-L")) {
+			i++; a = argv[i];
+			if (i >= argc) fatal("Not enough arguments to -L", NULL);
+			check_lg2(sscanf(a, "%d,%d", &o->start_line, &o->end_line)-2, "-L format error", NULL);
+		}
+		else {
+			/* commit range */
+			if (o->commitspec) fatal("Only one commit spec allowed", NULL);
+			o->commitspec = a;
+		}
+	}
+
+	/* Handle the bare arguments */
+	if (!bare_args[0]) usage("Please specify a path", NULL);
+	o->path = bare_args[0];
+	if (bare_args[1]) {
+		/* <commitspec> <path> */
+		o->path = bare_args[1];
+		o->commitspec = bare_args[0];
+	}
+	if (bare_args[2]) {
+		/* <oldcommit> <newcommit> <path> */
+		char spec[128] = {0};
+		o->path = bare_args[2];
+		sprintf(spec, "%s..%s", bare_args[0], bare_args[1]);
+		o->commitspec = spec;
+	}
+}

vendor/libgit2-sys/libgit2/examples/cat-file.c

diff --git a/vendor/libgit2-sys/libgit2/examples/cat-file.c b/vendor/libgit2-sys/libgit2/examples/cat-file.c
new file mode 100644
index 0000000..f948740
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/cat-file.c
@@ -0,0 +1,246 @@
+/*
+ * libgit2 "cat-file" example - shows how to print data from the ODB
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include "common.h"
+
+static void print_signature(const char *header, const git_signature *sig)
+{
+	char sign;
+	int offset, hours, minutes;
+
+	if (!sig)
+		return;
+
+	offset = sig->when.offset;
+	if (offset < 0) {
+		sign = '-';
+		offset = -offset;
+	} else {
+		sign = '+';
+	}
+
+	hours   = offset / 60;
+	minutes = offset % 60;
+
+	printf("%s %s <%s> %ld %c%02d%02d\n",
+		   header, sig->name, sig->email, (long)sig->when.time,
+		   sign, hours, minutes);
+}
+
+/** Printing out a blob is simple, get the contents and print */
+static void show_blob(const git_blob *blob)
+{
+	/* ? Does this need crlf filtering? */
+	fwrite(git_blob_rawcontent(blob), (size_t)git_blob_rawsize(blob), 1, stdout);
+}
+
+/** Show each entry with its type, id and attributes */
+static void show_tree(const git_tree *tree)
+{
+	size_t i, max_i = (int)git_tree_entrycount(tree);
+	char oidstr[GIT_OID_HEXSZ + 1];
+	const git_tree_entry *te;
+
+	for (i = 0; i < max_i; ++i) {
+		te = git_tree_entry_byindex(tree, i);
+
+		git_oid_tostr(oidstr, sizeof(oidstr), git_tree_entry_id(te));
+
+		printf("%06o %s %s\t%s\n",
+			git_tree_entry_filemode(te),
+			git_object_type2string(git_tree_entry_type(te)),
+			oidstr, git_tree_entry_name(te));
+	}
+}
+
+/**
+ * Commits and tags have a few interesting fields in their header.
+ */
+static void show_commit(const git_commit *commit)
+{
+	unsigned int i, max_i;
+	char oidstr[GIT_OID_HEXSZ + 1];
+
+	git_oid_tostr(oidstr, sizeof(oidstr), git_commit_tree_id(commit));
+	printf("tree %s\n", oidstr);
+
+	max_i = (unsigned int)git_commit_parentcount(commit);
+	for (i = 0; i < max_i; ++i) {
+		git_oid_tostr(oidstr, sizeof(oidstr), git_commit_parent_id(commit, i));
+		printf("parent %s\n", oidstr);
+	}
+
+	print_signature("author", git_commit_author(commit));
+	print_signature("committer", git_commit_committer(commit));
+
+	if (git_commit_message(commit))
+		printf("\n%s\n", git_commit_message(commit));
+}
+
+static void show_tag(const git_tag *tag)
+{
+	char oidstr[GIT_OID_HEXSZ + 1];
+
+	git_oid_tostr(oidstr, sizeof(oidstr), git_tag_target_id(tag));;
+	printf("object %s\n", oidstr);
+	printf("type %s\n", git_object_type2string(git_tag_target_type(tag)));
+	printf("tag %s\n", git_tag_name(tag));
+	print_signature("tagger", git_tag_tagger(tag));
+
+	if (git_tag_message(tag))
+		printf("\n%s\n", git_tag_message(tag));
+}
+
+enum {
+	SHOW_TYPE = 1,
+	SHOW_SIZE = 2,
+	SHOW_NONE = 3,
+	SHOW_PRETTY = 4
+};
+
+/* Forward declarations for option-parsing helper */
+struct opts {
+	const char *dir;
+	const char *rev;
+	int action;
+	int verbose;
+};
+static void parse_opts(struct opts *o, int argc, char *argv[]);
+
+
+/** Entry point for this command */
+int main(int argc, char *argv[])
+{
+	git_repository *repo;
+	struct opts o = { ".", NULL, 0, 0 };
+	git_object *obj = NULL;
+	char oidstr[GIT_OID_HEXSZ + 1];
+
+	git_libgit2_init();
+
+	parse_opts(&o, argc, argv);
+
+	check_lg2(git_repository_open_ext(&repo, o.dir, 0, NULL),
+			"Could not open repository", NULL);
+	check_lg2(git_revparse_single(&obj, repo, o.rev),
+			"Could not resolve", o.rev);
+
+	if (o.verbose) {
+		char oidstr[GIT_OID_HEXSZ + 1];
+		git_oid_tostr(oidstr, sizeof(oidstr), git_object_id(obj));
+
+		printf("%s %s\n--\n",
+			git_object_type2string(git_object_type(obj)), oidstr);
+	}
+
+	switch (o.action) {
+	case SHOW_TYPE:
+		printf("%s\n", git_object_type2string(git_object_type(obj)));
+		break;
+	case SHOW_SIZE: {
+		git_odb *odb;
+		git_odb_object *odbobj;
+
+		check_lg2(git_repository_odb(&odb, repo), "Could not open ODB", NULL);
+		check_lg2(git_odb_read(&odbobj, odb, git_object_id(obj)),
+			"Could not find obj", NULL);
+
+		printf("%ld\n", (long)git_odb_object_size(odbobj));
+
+		git_odb_object_free(odbobj);
+		git_odb_free(odb);
+		}
+		break;
+	case SHOW_NONE:
+		/* just want return result */
+		break;
+	case SHOW_PRETTY:
+
+		switch (git_object_type(obj)) {
+		case GIT_OBJ_BLOB:
+			show_blob((const git_blob *)obj);
+			break;
+		case GIT_OBJ_COMMIT:
+			show_commit((const git_commit *)obj);
+			break;
+		case GIT_OBJ_TREE:
+			show_tree((const git_tree *)obj);
+			break;
+		case GIT_OBJ_TAG:
+			show_tag((const git_tag *)obj);
+			break;
+		default:
+			printf("unknown %s\n", oidstr);
+			break;
+		}
+		break;
+	}
+
+	git_object_free(obj);
+	git_repository_free(repo);
+
+	git_libgit2_shutdown();
+
+	return 0;
+}
+
+/** Print out usage information */
+static void usage(const char *message, const char *arg)
+{
+	if (message && arg)
+		fprintf(stderr, "%s: %s\n", message, arg);
+	else if (message)
+		fprintf(stderr, "%s\n", message);
+	fprintf(stderr,
+			"usage: cat-file (-t | -s | -e | -p) [-v] [-q] "
+			"[-h|--help] [--git-dir=<dir>] <object>\n");
+	exit(1);
+}
+
+/** Parse the command-line options taken from git */
+static void parse_opts(struct opts *o, int argc, char *argv[])
+{
+	struct args_info args = ARGS_INFO_INIT;
+
+	for (args.pos = 1; args.pos < argc; ++args.pos) {
+		char *a = argv[args.pos];
+
+		if (a[0] != '-') {
+			if (o->rev != NULL)
+				usage("Only one rev should be provided", NULL);
+			else
+				o->rev = a;
+		}
+		else if (!strcmp(a, "-t"))
+			o->action = SHOW_TYPE;
+		else if (!strcmp(a, "-s"))
+			o->action = SHOW_SIZE;
+		else if (!strcmp(a, "-e"))
+			o->action = SHOW_NONE;
+		else if (!strcmp(a, "-p"))
+			o->action = SHOW_PRETTY;
+		else if (!strcmp(a, "-q"))
+			o->verbose = 0;
+		else if (!strcmp(a, "-v"))
+			o->verbose = 1;
+		else if (!strcmp(a, "--help") || !strcmp(a, "-h"))
+			usage(NULL, NULL);
+		else if (!match_str_arg(&o->dir, &args, "--git-dir"))
+			usage("Unknown option", a);
+	}
+
+	if (!o->action || !o->rev)
+		usage(NULL, NULL);
+
+}

vendor/libgit2-sys/libgit2/examples/common.c

diff --git a/vendor/libgit2-sys/libgit2/examples/common.c b/vendor/libgit2-sys/libgit2/examples/common.c
new file mode 100644
index 0000000..1180720
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/common.c
@@ -0,0 +1,247 @@
+/*
+ * Utilities library for libgit2 examples
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include "common.h"
+
+void check_lg2(int error, const char *message, const char *extra)
+{
+	const git_error *lg2err;
+	const char *lg2msg = "", *lg2spacer = "";
+
+	if (!error)
+		return;
+
+	if ((lg2err = giterr_last()) != NULL && lg2err->message != NULL) {
+		lg2msg = lg2err->message;
+		lg2spacer = " - ";
+	}
+
+	if (extra)
+		fprintf(stderr, "%s '%s' [%d]%s%s\n",
+			message, extra, error, lg2spacer, lg2msg);
+	else
+		fprintf(stderr, "%s [%d]%s%s\n",
+			message, error, lg2spacer, lg2msg);
+
+	exit(1);
+}
+
+void fatal(const char *message, const char *extra)
+{
+	if (extra)
+		fprintf(stderr, "%s %s\n", message, extra);
+	else
+		fprintf(stderr, "%s\n", message);
+
+	exit(1);
+}
+
+size_t is_prefixed(const char *str, const char *pfx)
+{
+	size_t len = strlen(pfx);
+	return strncmp(str, pfx, len) ? 0 : len;
+}
+
+int optional_str_arg(
+	const char **out, struct args_info *args, const char *opt, const char *def)
+{
+	const char *found = args->argv[args->pos];
+	size_t len = is_prefixed(found, opt);
+
+	if (!len)
+		return 0;
+
+	if (!found[len]) {
+		if (args->pos + 1 == args->argc) {
+			*out = def;
+			return 1;
+		}
+		args->pos += 1;
+		*out = args->argv[args->pos];
+		return 1;
+	}
+
+	if (found[len] == '=') {
+		*out = found + len + 1;
+		return 1;
+	}
+
+	return 0;
+}
+
+int match_str_arg(
+	const char **out, struct args_info *args, const char *opt)
+{
+	const char *found = args->argv[args->pos];
+	size_t len = is_prefixed(found, opt);
+
+	if (!len)
+		return 0;
+
+	if (!found[len]) {
+		if (args->pos + 1 == args->argc)
+			fatal("expected value following argument", opt);
+		args->pos += 1;
+		*out = args->argv[args->pos];
+		return 1;
+	}
+
+	if (found[len] == '=') {
+		*out = found + len + 1;
+		return 1;
+	}
+
+	return 0;
+}
+
+static const char *match_numeric_arg(struct args_info *args, const char *opt)
+{
+	const char *found = args->argv[args->pos];
+	size_t len = is_prefixed(found, opt);
+
+	if (!len)
+		return NULL;
+
+	if (!found[len]) {
+		if (args->pos + 1 == args->argc)
+			fatal("expected numeric value following argument", opt);
+		args->pos += 1;
+		found = args->argv[args->pos];
+	} else {
+		found = found + len;
+		if (*found == '=')
+			found++;
+	}
+
+	return found;
+}
+
+int match_uint16_arg(
+	uint16_t *out, struct args_info *args, const char *opt)
+{
+	const char *found = match_numeric_arg(args, opt);
+	uint16_t val;
+	char *endptr = NULL;
+
+	if (!found)
+		return 0;
+
+	val = (uint16_t)strtoul(found, &endptr, 0);
+	if (!endptr || *endptr != '\0')
+		fatal("expected number after argument", opt);
+
+	if (out)
+		*out = val;
+	return 1;
+}
+
+int match_uint32_arg(
+	uint32_t *out, struct args_info *args, const char *opt)
+{
+	const char *found = match_numeric_arg(args, opt);
+	uint16_t val;
+	char *endptr = NULL;
+
+	if (!found)
+		return 0;
+
+	val = (uint32_t)strtoul(found, &endptr, 0);
+	if (!endptr || *endptr != '\0')
+		fatal("expected number after argument", opt);
+
+	if (out)
+		*out = val;
+	return 1;
+}
+
+static int match_int_internal(
+	int *out, const char *str, int allow_negative, const char *opt)
+{
+	char *endptr = NULL;
+	int	  val = (int)strtol(str, &endptr, 10);
+
+	if (!endptr || *endptr != '\0')
+		fatal("expected number", opt);
+	else if (val < 0 && !allow_negative)
+		fatal("negative values are not allowed", opt);
+
+	if (out)
+		*out = val;
+
+	return 1;
+}
+
+int is_integer(int *out, const char *str, int allow_negative)
+{
+	return match_int_internal(out, str, allow_negative, NULL);
+}
+
+int match_int_arg(
+	int *out, struct args_info *args, const char *opt, int allow_negative)
+{
+	const char *found = match_numeric_arg(args, opt);
+	if (!found)
+		return 0;
+	return match_int_internal(out, found, allow_negative, opt);
+}
+
+int diff_output(
+	const git_diff_delta *d,
+	const git_diff_hunk *h,
+	const git_diff_line *l,
+	void *p)
+{
+	FILE *fp = (FILE*)p;
+
+	(void)d; (void)h;
+
+	if (!fp)
+		fp = stdout;
+
+	if (l->origin == GIT_DIFF_LINE_CONTEXT ||
+		l->origin == GIT_DIFF_LINE_ADDITION ||
+		l->origin == GIT_DIFF_LINE_DELETION)
+		fputc(l->origin, fp);
+
+	fwrite(l->content, 1, l->content_len, fp);
+
+	return 0;
+}
+
+void treeish_to_tree(
+	git_tree **out, git_repository *repo, const char *treeish)
+{
+	git_object *obj = NULL;
+
+	check_lg2(
+		git_revparse_single(&obj, repo, treeish),
+		"looking up object", treeish);
+
+	check_lg2(
+		git_object_peel((git_object **)out, obj, GIT_OBJ_TREE),
+		"resolving object to tree", treeish);
+
+	git_object_free(obj);
+}
+
+void *xrealloc(void *oldp, size_t newsz)
+{
+	void *p = realloc(oldp, newsz);
+	if (p == NULL) {
+		fprintf(stderr, "Cannot allocate memory, exiting.\n");
+		exit(1);
+	}
+	return p;
+}
+

vendor/libgit2-sys/libgit2/examples/common.h

diff --git a/vendor/libgit2-sys/libgit2/examples/common.h b/vendor/libgit2-sys/libgit2/examples/common.h
new file mode 100644
index 0000000..af42324
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/common.h
@@ -0,0 +1,110 @@
+/*
+ * Utilities library for libgit2 examples
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <git2.h>
+
+/**
+ * Check libgit2 error code, printing error to stderr on failure and
+ * exiting the program.
+ */
+extern void check_lg2(int error, const char *message, const char *extra);
+
+/**
+ * Exit the program, printing error to stderr
+ */
+extern void fatal(const char *message, const char *extra);
+
+/**
+ * Check if a string has the given prefix.  Returns 0 if not prefixed
+ * or the length of the prefix if it is.
+ */
+extern size_t is_prefixed(const char *str, const char *pfx);
+
+/**
+ * Match an integer string, returning 1 if matched, 0 if not.
+ */
+extern int is_integer(int *out, const char *str, int allow_negative);
+
+struct args_info {
+	int    argc;
+	char **argv;
+	int    pos;
+};
+#define ARGS_INFO_INIT { argc, argv, 0 }
+
+/**
+ * Check current `args` entry against `opt` string.  If it matches
+ * exactly, take the next arg as a string; if it matches as a prefix with
+ * an equal sign, take the remainder as a string; if value not supplied, 
+ * default value `def` will be given. otherwise return 0.
+ */
+extern int optional_str_arg(
+	const char **out, struct args_info *args, const char *opt, const char *def);
+
+/**
+ * Check current `args` entry against `opt` string.  If it matches
+ * exactly, take the next arg as a string; if it matches as a prefix with
+ * an equal sign, take the remainder as a string; otherwise return 0.
+ */
+extern int match_str_arg(
+	const char **out, struct args_info *args, const char *opt);
+
+/**
+ * Check current `args` entry against `opt` string parsing as uint16.  If
+ * `opt` matches exactly, take the next arg as a uint16_t value; if `opt`
+ * is a prefix (equal sign optional), take the remainder of the arg as a
+ * uint16_t value; otherwise return 0.
+ */
+extern int match_uint16_arg(
+	uint16_t *out, struct args_info *args, const char *opt);
+
+/**
+ * Check current `args` entry against `opt` string parsing as uint32.  If
+ * `opt` matches exactly, take the next arg as a uint16_t value; if `opt`
+ * is a prefix (equal sign optional), take the remainder of the arg as a
+ * uint32_t value; otherwise return 0.
+ */
+extern int match_uint32_arg(
+	uint32_t *out, struct args_info *args, const char *opt);
+
+/**
+ * Check current `args` entry against `opt` string parsing as int.  If
+ * `opt` matches exactly, take the next arg as an int value; if it matches
+ * as a prefix (equal sign optional), take the remainder of the arg as a
+ * int value; otherwise return 0.
+ */
+extern int match_int_arg(
+	int *out, struct args_info *args, const char *opt, int allow_negative);
+
+/**
+ * Basic output function for plain text diff output
+ * Pass `FILE*` such as `stdout` or `stderr` as payload (or NULL == `stdout`)
+ */
+extern int diff_output(
+	const git_diff_delta*, const git_diff_hunk*, const git_diff_line*, void*);
+
+/**
+ * Convert a treeish argument to an actual tree; this will call check_lg2
+ * and exit the program if `treeish` cannot be resolved to a tree
+ */
+extern void treeish_to_tree(
+	git_tree **out, git_repository *repo, const char *treeish);
+
+/**
+ * A realloc that exits on failure
+ */
+extern void *xrealloc(void *oldp, size_t newsz);

vendor/libgit2-sys/libgit2/examples/describe.c

diff --git a/vendor/libgit2-sys/libgit2/examples/describe.c b/vendor/libgit2-sys/libgit2/examples/describe.c
new file mode 100644
index 0000000..2005de4
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/describe.c
@@ -0,0 +1,174 @@
+/*
+ * libgit2 "describe" example - shows how to describe commits
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include "common.h"
+#include <assert.h>
+
+/**
+ * The following example partially reimplements the `git describe` command
+ * and some of its options.
+ *
+ * These commands should work:
+
+ * - Describe HEAD with default options (`describe`)
+ * - Describe specified revision (`describe master~2`)
+ * - Describe specified revisions (`describe master~2 HEAD~3`)
+ * - Describe HEAD with dirty state suffix (`describe --dirty=*`)
+ * - Describe consider all refs (`describe --all master`)
+ * - Describe consider lightweight tags (`describe --tags temp-tag`)
+ * - Describe show non-default abbreviated size (`describe --abbrev=10`)
+ * - Describe always output the long format if matches a tag (`describe --long v1.0`)
+ * - Describe consider only tags of specified pattern (`describe --match v*-release`)
+ * - Describe show the fallback result (`describe --always`)
+ * - Describe follow only the first parent commit (`describe --first-parent`)
+ *
+ * The command line parsing logic is simplified and doesn't handle
+ * all of the use cases.
+ */
+
+/** describe_options represents the parsed command line options */
+typedef struct {
+	const char **commits;
+	size_t commit_count;
+	git_describe_options describe_options;
+	git_describe_format_options format_options;
+} describe_options;
+
+typedef struct args_info args_info;
+
+static void opts_add_commit(describe_options *opts, const char *commit)
+{
+	size_t sz;
+
+	assert(opts != NULL);
+
+	sz = ++opts->commit_count * sizeof(opts->commits[0]);
+	opts->commits = xrealloc(opts->commits, sz);
+	opts->commits[opts->commit_count - 1] = commit;
+}
+
+static void do_describe_single(git_repository *repo, describe_options *opts, const char *rev)
+{
+	git_object *commit;
+	git_describe_result *describe_result;
+	git_buf buf = { 0 };
+	
+	if (rev) {
+		check_lg2(git_revparse_single(&commit, repo, rev),
+			"Failed to lookup rev", rev);
+
+		check_lg2(git_describe_commit(&describe_result, commit, &opts->describe_options),
+			"Failed to describe rev", rev);
+	}
+	else
+		check_lg2(git_describe_workdir(&describe_result, repo, &opts->describe_options),
+			"Failed to describe workdir", NULL);
+
+	check_lg2(git_describe_format(&buf, describe_result, &opts->format_options),
+			"Failed to format describe rev", rev);
+
+	printf("%s\n", buf.ptr);
+}
+
+static void do_describe(git_repository *repo, describe_options *opts)
+{
+	if (opts->commit_count == 0)
+		do_describe_single(repo, opts, NULL);
+	else
+	{
+		size_t i;
+		for (i = 0; i < opts->commit_count; i++)
+			do_describe_single(repo, opts, opts->commits[i]);
+	}
+}
+
+static void print_usage(void)
+{
+	fprintf(stderr, "usage: see `git help describe`\n");
+	exit(1);
+}
+
+/** Parse command line arguments */
+static void parse_options(describe_options *opts, int argc, char **argv)
+{
+	args_info args = ARGS_INFO_INIT;
+
+	for (args.pos = 1; args.pos < argc; ++args.pos) {
+		const char *curr = argv[args.pos];
+
+		if (curr[0] != '-') {
+			opts_add_commit(opts, curr);
+		} else if (!strcmp(curr, "--all")) {
+			opts->describe_options.describe_strategy = GIT_DESCRIBE_ALL;
+		} else if (!strcmp(curr, "--tags")) {
+			opts->describe_options.describe_strategy = GIT_DESCRIBE_TAGS;
+		} else if (!strcmp(curr, "--exact-match")) {
+			opts->describe_options.max_candidates_tags = 0;
+		} else if (!strcmp(curr, "--long")) {
+			opts->format_options.always_use_long_format = 1;
+		} else if (!strcmp(curr, "--always")) {
+			opts->describe_options.show_commit_oid_as_fallback = 1;
+		} else if (!strcmp(curr, "--first-parent")) {
+			opts->describe_options.only_follow_first_parent = 1;
+		} else if (optional_str_arg(&opts->format_options.dirty_suffix, &args, "--dirty", "-dirty")) {
+		} else if (match_int_arg((int *)&opts->format_options.abbreviated_size, &args, "--abbrev", 0)) {
+		} else if (match_int_arg((int *)&opts->describe_options.max_candidates_tags, &args, "--candidates", 0)) {
+		} else if (match_str_arg(&opts->describe_options.pattern, &args, "--match")) {
+		} else {
+			print_usage();
+		}
+	}
+
+	if (opts->commit_count > 0) {
+		if (opts->format_options.dirty_suffix)
+			fatal("--dirty is incompatible with commit-ishes", NULL);
+	}
+	else {
+		if (!opts->format_options.dirty_suffix || !opts->format_options.dirty_suffix[0]) {
+			opts_add_commit(opts, "HEAD");
+		}
+	}
+}
+
+/** Initialize describe_options struct */
+static void describe_options_init(describe_options *opts)
+{
+	memset(opts, 0, sizeof(*opts));
+
+	opts->commits = NULL;
+	opts->commit_count = 0;
+	git_describe_init_options(&opts->describe_options, GIT_DESCRIBE_OPTIONS_VERSION);
+	git_describe_init_format_options(&opts->format_options, GIT_DESCRIBE_FORMAT_OPTIONS_VERSION);
+}
+
+int main(int argc, char **argv)
+{
+	git_repository *repo;
+	describe_options opts;
+
+	git_libgit2_init();
+
+	check_lg2(git_repository_open_ext(&repo, ".", 0, NULL),
+			"Could not open repository", NULL);
+
+	describe_options_init(&opts);
+	parse_options(&opts, argc, argv);
+
+	do_describe(repo, &opts);
+
+	git_repository_free(repo);
+	git_libgit2_shutdown();
+
+	return 0;
+}

vendor/libgit2-sys/libgit2/examples/diff.c

diff --git a/vendor/libgit2-sys/libgit2/examples/diff.c b/vendor/libgit2-sys/libgit2/examples/diff.c
new file mode 100644
index 0000000..9a4f7a5
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/diff.c
@@ -0,0 +1,337 @@
+/*
+ * libgit2 "diff" example - shows how to use the diff API
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include "common.h"
+
+/**
+ * This example demonstrates the use of the libgit2 diff APIs to
+ * create `git_diff` objects and display them, emulating a number of
+ * core Git `diff` command line options.
+ *
+ * This covers on a portion of the core Git diff options and doesn't
+ * have particularly good error handling, but it should show most of
+ * the core libgit2 diff APIs, including various types of diffs and
+ * how to do renaming detection and patch formatting.
+ */
+
+static const char *colors[] = {
+	"\033[m", /* reset */
+	"\033[1m", /* bold */
+	"\033[31m", /* red */
+	"\033[32m", /* green */
+	"\033[36m" /* cyan */
+};
+
+enum {
+	OUTPUT_DIFF = (1 << 0),
+	OUTPUT_STAT = (1 << 1),
+	OUTPUT_SHORTSTAT = (1 << 2),
+	OUTPUT_NUMSTAT = (1 << 3),
+	OUTPUT_SUMMARY = (1 << 4)
+};
+
+enum {
+	CACHE_NORMAL = 0,
+	CACHE_ONLY = 1,
+	CACHE_NONE = 2
+};
+
+/** The 'opts' struct captures all the various parsed command line options. */
+struct opts {
+	git_diff_options diffopts;
+	git_diff_find_options findopts;
+	int color;
+	int cache;
+	int output;
+	git_diff_format_t format;
+	const char *treeish1;
+	const char *treeish2;
+	const char *dir;
+};
+
+/** These functions are implemented at the end */
+static void usage(const char *message, const char *arg);
+static void parse_opts(struct opts *o, int argc, char *argv[]);
+static int color_printer(
+	const git_diff_delta*, const git_diff_hunk*, const git_diff_line*, void*);
+static void diff_print_stats(git_diff *diff, struct opts *o);
+
+int main(int argc, char *argv[])
+{
+	git_repository *repo = NULL;
+	git_tree *t1 = NULL, *t2 = NULL;
+	git_diff *diff;
+	struct opts o = {
+		GIT_DIFF_OPTIONS_INIT, GIT_DIFF_FIND_OPTIONS_INIT,
+		-1, 0, 0, GIT_DIFF_FORMAT_PATCH, NULL, NULL, "."
+	};
+
+	git_libgit2_init();
+
+	parse_opts(&o, argc, argv);
+
+	check_lg2(git_repository_open_ext(&repo, o.dir, 0, NULL),
+		"Could not open repository", o.dir);
+
+	/**
+	 * Possible argument patterns:
+	 *
+	 *  * &lt;sha1&gt; &lt;sha2&gt;
+	 *  * &lt;sha1&gt; --cached
+	 *  * &lt;sha1&gt;
+	 *  * --cached
+	 *  * --nocache (don't use index data in diff at all)
+	 *  * nothing
+	 *
+	 * Currently ranged arguments like &lt;sha1&gt;..&lt;sha2&gt; and &lt;sha1&gt;...&lt;sha2&gt;
+	 * are not supported in this example
+	 */
+
+	if (o.treeish1)
+		treeish_to_tree(&t1, repo, o.treeish1);
+	if (o.treeish2)
+		treeish_to_tree(&t2, repo, o.treeish2);
+
+	if (t1 && t2)
+		check_lg2(
+			git_diff_tree_to_tree(&diff, repo, t1, t2, &o.diffopts),
+			"diff trees", NULL);
+	else if (o.cache != CACHE_NORMAL) {
+		if (!t1)
+			treeish_to_tree(&t1, repo, "HEAD");
+
+		if (o.cache == CACHE_NONE)
+			check_lg2(
+				git_diff_tree_to_workdir(&diff, repo, t1, &o.diffopts),
+				"diff tree to working directory", NULL);
+		else
+			check_lg2(
+				git_diff_tree_to_index(&diff, repo, t1, NULL, &o.diffopts),
+				"diff tree to index", NULL);
+	}
+	else if (t1)
+		check_lg2(
+			git_diff_tree_to_workdir_with_index(&diff, repo, t1, &o.diffopts),
+			"diff tree to working directory", NULL);
+	else
+		check_lg2(
+			git_diff_index_to_workdir(&diff, repo, NULL, &o.diffopts),
+			"diff index to working directory", NULL);
+
+	/** Apply rename and copy detection if requested. */
+
+	if ((o.findopts.flags & GIT_DIFF_FIND_ALL) != 0)
+		check_lg2(
+			git_diff_find_similar(diff, &o.findopts),
+			"finding renames and copies", NULL);
+
+	/** Generate simple output using libgit2 display helper. */
+
+	if (!o.output)
+		o.output = OUTPUT_DIFF;
+
+	if (o.output != OUTPUT_DIFF)
+		diff_print_stats(diff, &o);
+
+	if ((o.output & OUTPUT_DIFF) != 0) {
+		if (o.color >= 0)
+			fputs(colors[0], stdout);
+
+		check_lg2(
+			git_diff_print(diff, o.format, color_printer, &o.color),
+			"displaying diff", NULL);
+
+		if (o.color >= 0)
+			fputs(colors[0], stdout);
+	}
+
+	/** Cleanup before exiting. */
+
+	git_diff_free(diff);
+	git_tree_free(t1);
+	git_tree_free(t2);
+	git_repository_free(repo);
+
+	git_libgit2_shutdown();
+
+	return 0;
+}
+
+static void usage(const char *message, const char *arg)
+{
+	if (message && arg)
+		fprintf(stderr, "%s: %s\n", message, arg);
+	else if (message)
+		fprintf(stderr, "%s\n", message);
+	fprintf(stderr, "usage: diff [<tree-oid> [<tree-oid>]]\n");
+	exit(1);
+}
+
+/** This implements very rudimentary colorized output. */
+static int color_printer(
+	const git_diff_delta *delta,
+	const git_diff_hunk *hunk,
+	const git_diff_line *line,
+	void *data)
+{
+	int *last_color = data, color = 0;
+
+	(void)delta; (void)hunk;
+
+	if (*last_color >= 0) {
+		switch (line->origin) {
+		case GIT_DIFF_LINE_ADDITION:  color = 3; break;
+		case GIT_DIFF_LINE_DELETION:  color = 2; break;
+		case GIT_DIFF_LINE_ADD_EOFNL: color = 3; break;
+		case GIT_DIFF_LINE_DEL_EOFNL: color = 2; break;
+		case GIT_DIFF_LINE_FILE_HDR:  color = 1; break;
+		case GIT_DIFF_LINE_HUNK_HDR:  color = 4; break;
+		default: break;
+		}
+
+		if (color != *last_color) {
+			if (*last_color == 1 || color == 1)
+				fputs(colors[0], stdout);
+			fputs(colors[color], stdout);
+			*last_color = color;
+		}
+	}
+
+	return diff_output(delta, hunk, line, stdout);
+}
+
+/** Parse arguments as copied from git-diff. */
+static void parse_opts(struct opts *o, int argc, char *argv[])
+{
+	struct args_info args = ARGS_INFO_INIT;
+
+
+	for (args.pos = 1; args.pos < argc; ++args.pos) {
+		const char *a = argv[args.pos];
+
+		if (a[0] != '-') {
+			if (o->treeish1 == NULL)
+				o->treeish1 = a;
+			else if (o->treeish2 == NULL)
+				o->treeish2 = a;
+			else
+				usage("Only one or two tree identifiers can be provided", NULL);
+		}
+		else if (!strcmp(a, "-p") || !strcmp(a, "-u") ||
+				 !strcmp(a, "--patch")) {
+			o->output |= OUTPUT_DIFF;
+			o->format = GIT_DIFF_FORMAT_PATCH;
+		}
+		else if (!strcmp(a, "--cached"))
+			o->cache = CACHE_ONLY;
+		else if (!strcmp(a, "--nocache"))
+			o->cache = CACHE_NONE;
+		else if (!strcmp(a, "--name-only") || !strcmp(a, "--format=name"))
+			o->format = GIT_DIFF_FORMAT_NAME_ONLY;
+		else if (!strcmp(a, "--name-status") ||
+				!strcmp(a, "--format=name-status"))
+			o->format = GIT_DIFF_FORMAT_NAME_STATUS;
+		else if (!strcmp(a, "--raw") || !strcmp(a, "--format=raw"))
+			o->format = GIT_DIFF_FORMAT_RAW;
+		else if (!strcmp(a, "--format=diff-index")) {
+			o->format = GIT_DIFF_FORMAT_RAW;
+			o->diffopts.id_abbrev = 40;
+		}
+		else if (!strcmp(a, "--color"))
+			o->color = 0;
+		else if (!strcmp(a, "--no-color"))
+			o->color = -1;
+		else if (!strcmp(a, "-R"))
+			o->diffopts.flags |= GIT_DIFF_REVERSE;
+		else if (!strcmp(a, "-a") || !strcmp(a, "--text"))
+			o->diffopts.flags |= GIT_DIFF_FORCE_TEXT;
+		else if (!strcmp(a, "--ignore-space-at-eol"))
+			o->diffopts.flags |= GIT_DIFF_IGNORE_WHITESPACE_EOL;
+		else if (!strcmp(a, "-b") || !strcmp(a, "--ignore-space-change"))
+			o->diffopts.flags |= GIT_DIFF_IGNORE_WHITESPACE_CHANGE;
+		else if (!strcmp(a, "-w") || !strcmp(a, "--ignore-all-space"))
+			o->diffopts.flags |= GIT_DIFF_IGNORE_WHITESPACE;
+		else if (!strcmp(a, "--ignored"))
+			o->diffopts.flags |= GIT_DIFF_INCLUDE_IGNORED;
+		else if (!strcmp(a, "--untracked"))
+			o->diffopts.flags |= GIT_DIFF_INCLUDE_UNTRACKED;
+		else if (!strcmp(a, "--patience"))
+			o->diffopts.flags |= GIT_DIFF_PATIENCE;
+		else if (!strcmp(a, "--minimal"))
+			o->diffopts.flags |= GIT_DIFF_MINIMAL;
+		else if (!strcmp(a, "--stat"))
+			o->output |= OUTPUT_STAT;
+		else if (!strcmp(a, "--numstat"))
+			o->output |= OUTPUT_NUMSTAT;
+		else if (!strcmp(a, "--shortstat"))
+			o->output |= OUTPUT_SHORTSTAT;
+		else if (!strcmp(a, "--summary"))
+			o->output |= OUTPUT_SUMMARY;
+		else if (match_uint16_arg(
+				&o->findopts.rename_threshold, &args, "-M") ||
+			match_uint16_arg(
+				&o->findopts.rename_threshold, &args, "--find-renames"))
+			o->findopts.flags |= GIT_DIFF_FIND_RENAMES;
+		else if (match_uint16_arg(
+				&o->findopts.copy_threshold, &args, "-C") ||
+			match_uint16_arg(
+				&o->findopts.copy_threshold, &args, "--find-copies"))
+			o->findopts.flags |= GIT_DIFF_FIND_COPIES;
+		else if (!strcmp(a, "--find-copies-harder"))
+			o->findopts.flags |= GIT_DIFF_FIND_COPIES_FROM_UNMODIFIED;
+		else if (is_prefixed(a, "-B") || is_prefixed(a, "--break-rewrites"))
+			/* TODO: parse thresholds */
+			o->findopts.flags |= GIT_DIFF_FIND_REWRITES;
+		else if (!match_uint32_arg(
+				&o->diffopts.context_lines, &args, "-U") &&
+			!match_uint32_arg(
+				&o->diffopts.context_lines, &args, "--unified") &&
+			!match_uint32_arg(
+				&o->diffopts.interhunk_lines, &args, "--inter-hunk-context") &&
+			!match_uint16_arg(
+				&o->diffopts.id_abbrev, &args, "--abbrev") &&
+			!match_str_arg(&o->diffopts.old_prefix, &args, "--src-prefix") &&
+			!match_str_arg(&o->diffopts.new_prefix, &args, "--dst-prefix") &&
+			!match_str_arg(&o->dir, &args, "--git-dir"))
+			usage("Unknown command line argument", a);
+	}
+}
+
+/** Display diff output with "--stat", "--numstat", or "--shortstat" */
+static void diff_print_stats(git_diff *diff, struct opts *o)
+{
+	git_diff_stats *stats;
+	git_buf b = GIT_BUF_INIT_CONST(NULL, 0);
+	git_diff_stats_format_t format = 0;
+
+	check_lg2(
+		git_diff_get_stats(&stats, diff), "generating stats for diff", NULL);
+
+	if (o->output & OUTPUT_STAT)
+		format |= GIT_DIFF_STATS_FULL;
+	if (o->output & OUTPUT_SHORTSTAT)
+		format |= GIT_DIFF_STATS_SHORT;
+	if (o->output & OUTPUT_NUMSTAT)
+		format |= GIT_DIFF_STATS_NUMBER;
+	if (o->output & OUTPUT_SUMMARY)
+		format |= GIT_DIFF_STATS_INCLUDE_SUMMARY;
+
+	check_lg2(
+		git_diff_stats_to_buf(&b, stats, format, 80), "formatting stats", NULL);
+
+	fputs(b.ptr, stdout);
+
+	git_buf_free(&b);
+	git_diff_stats_free(stats);
+}

vendor/libgit2-sys/libgit2/examples/for-each-ref.c

diff --git a/vendor/libgit2-sys/libgit2/examples/for-each-ref.c b/vendor/libgit2-sys/libgit2/examples/for-each-ref.c
new file mode 100644
index 0000000..a8ceaaf
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/for-each-ref.c
@@ -0,0 +1,49 @@
+#include <git2.h>
+#include <stdio.h>
+#include "common.h"
+
+static int show_ref(git_reference *ref, void *data)
+{
+        git_repository *repo = data;
+        git_reference *resolved = NULL;
+        char hex[GIT_OID_HEXSZ+1];
+        const git_oid *oid;
+        git_object *obj;
+
+        if (git_reference_type(ref) == GIT_REF_SYMBOLIC)
+                check_lg2(git_reference_resolve(&resolved, ref),
+                          "Unable to resolve symbolic reference",
+                          git_reference_name(ref));
+
+        oid = git_reference_target(resolved ? resolved : ref);
+        git_oid_fmt(hex, oid);
+        hex[GIT_OID_HEXSZ] = 0;
+        check_lg2(git_object_lookup(&obj, repo, oid, GIT_OBJ_ANY),
+                  "Unable to lookup object", hex);
+
+        printf("%s %-6s\t%s\n",
+               hex,
+               git_object_type2string(git_object_type(obj)),
+               git_reference_name(ref));
+
+        if (resolved)
+                git_reference_free(resolved);
+        return 0;
+}
+
+int main(int argc, char **argv)
+{
+        git_repository *repo;
+        git_libgit2_init();
+
+        if (argc != 1 || argv[1] /* silence -Wunused-parameter */)
+                fatal("Sorry, no for-each-ref options supported yet", NULL);
+
+        check_lg2(git_repository_open(&repo, "."),
+                  "Could not open repository", NULL);
+        check_lg2(git_reference_foreach(repo, show_ref, repo),
+                  "Could not iterate over references", NULL);
+
+        git_libgit2_shutdown();
+        return 0;
+}

vendor/libgit2-sys/libgit2/examples/general.c

diff --git a/vendor/libgit2-sys/libgit2/examples/general.c b/vendor/libgit2-sys/libgit2/examples/general.c
new file mode 100644
index 0000000..0780d3d
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/general.c
@@ -0,0 +1,773 @@
+/*
+ * libgit2 "general" example - shows basic libgit2 concepts
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+/**
+ * [**libgit2**][lg] is a portable, pure C implementation of the Git core
+ * methods provided as a re-entrant linkable library with a solid API,
+ * allowing you to write native speed custom Git applications in any
+ * language which supports C bindings.
+ *
+ * This file is an example of using that API in a real, compilable C file.
+ * As the API is updated, this file will be updated to demonstrate the new
+ * functionality.
+ *
+ * If you're trying to write something in C using [libgit2][lg], you should
+ * also check out the generated [API documentation][ap]. We try to link to
+ * the relevant sections of the API docs in each section in this file.
+ *
+ * **libgit2** (for the most part) only implements the core plumbing
+ * functions, not really the higher level porcelain stuff. For a primer on
+ * Git Internals that you will need to know to work with Git at this level,
+ * check out [Chapter 10][pg] of the Pro Git book.
+ *
+ * [lg]: http://libgit2.github.com
+ * [ap]: http://libgit2.github.com/libgit2
+ * [pg]: https://git-scm.com/book/en/v2/Git-Internals-Plumbing-and-Porcelain
+ */
+
+/**
+ * ### Includes
+ *
+ * Including the `git2.h` header will include all the other libgit2 headers
+ * that you need.  It should be the only thing you need to include in order
+ * to compile properly and get all the libgit2 API.
+ */
+#include <git2.h>
+#include <stdio.h>
+#include <string.h>
+
+static void oid_parsing(git_oid *out);
+static void object_database(git_repository *repo, git_oid *oid);
+static void commit_writing(git_repository *repo);
+static void commit_parsing(git_repository *repo);
+static void tag_parsing(git_repository *repo);
+static void tree_parsing(git_repository *repo);
+static void blob_parsing(git_repository *repo);
+static void revwalking(git_repository *repo);
+static void index_walking(git_repository *repo);
+static void reference_listing(git_repository *repo);
+static void config_files(const char *repo_path, git_repository *repo);
+
+/**
+ * Almost all libgit2 functions return 0 on success or negative on error.
+ * This is not production quality error checking, but should be sufficient
+ * as an example.
+ */
+static void check_error(int error_code, const char *action)
+{
+	const git_error *error = giterr_last();
+	if (!error_code)
+		return;
+
+	printf("Error %d %s - %s\n", error_code, action,
+			(error && error->message) ? error->message : "???");
+
+	exit(1);
+}
+
+int main (int argc, char** argv)
+{
+	int error;
+	git_oid oid;
+	char *repo_path;
+	git_repository *repo;
+
+	/**
+	 * Initialize the library, this will set up any global state which libgit2 needs
+	 * including threading and crypto
+	 */
+	git_libgit2_init();
+
+	/**
+	 * ### Opening the Repository
+	 *
+	 * There are a couple of methods for opening a repository, this being the
+	 * simplest.  There are also [methods][me] for specifying the index file
+	 * and work tree locations, here we assume they are in the normal places.
+	 *
+	 * (Try running this program against tests/resources/testrepo.git.)
+	 *
+	 * [me]: http://libgit2.github.com/libgit2/#HEAD/group/repository
+	 */
+	repo_path = (argc > 1) ? argv[1] : "/opt/libgit2-test/.git";
+
+	error = git_repository_open(&repo, repo_path);
+	check_error(error, "opening repository");
+
+	oid_parsing(&oid);
+	object_database(repo, &oid);
+	commit_writing(repo);
+	commit_parsing(repo);
+	tag_parsing(repo);
+	tree_parsing(repo);
+	blob_parsing(repo);
+	revwalking(repo);
+	index_walking(repo);
+	reference_listing(repo);
+	config_files(repo_path, repo);
+
+	/**
+	 * Finally, when you're done with the repository, you can free it as well.
+	 */
+	git_repository_free(repo);
+
+	return 0;
+}
+
+/**
+ * ### SHA-1 Value Conversions
+ */
+static void oid_parsing(git_oid *oid)
+{
+	char out[GIT_OID_HEXSZ+1];
+	char hex[] = "4a202b346bb0fb0db7eff3cffeb3c70babbd2045";
+
+	printf("*Hex to Raw*\n");
+
+	/**
+	 * For our first example, we will convert a 40 character hex value to the
+	 * 20 byte raw SHA1 value.
+	 *
+	 * The `git_oid` is the structure that keeps the SHA value. We will use
+	 * this throughout the example for storing the value of the current SHA
+	 * key we're working with.
+	 */
+	git_oid_fromstr(oid, hex);
+
+	// Once we've converted the string into the oid value, we can get the raw
+	// value of the SHA by accessing `oid.id`
+
+	// Next we will convert the 20 byte raw SHA1 value to a human readable 40
+	// char hex value.
+	printf("\n*Raw to Hex*\n");
+	out[GIT_OID_HEXSZ] = '\0';
+
+	/**
+	 * If you have a oid, you can easily get the hex value of the SHA as well.
+	 */
+	git_oid_fmt(out, oid);
+
+	/**
+	 * If you have a oid, you can easily get the hex value of the SHA as well.
+	 */
+	git_oid_fmt(out, oid);
+	printf("SHA hex string: %s\n", out);
+}
+
+/**
+ * ### Working with the Object Database
+ *
+ * **libgit2** provides [direct access][odb] to the object database.  The
+ * object database is where the actual objects are stored in Git. For
+ * working with raw objects, we'll need to get this structure from the
+ * repository.
+ *
+ * [odb]: http://libgit2.github.com/libgit2/#HEAD/group/odb
+ */
+static void object_database(git_repository *repo, git_oid *oid)
+{
+	char oid_hex[GIT_OID_HEXSZ+1] = { 0 };
+	const unsigned char *data;
+	const char *str_type;
+	int error;
+	git_odb_object *obj;
+	git_odb *odb;
+	git_otype otype;
+
+	git_repository_odb(&odb, repo);
+
+	/**
+	 * #### Raw Object Reading
+	 */
+
+	printf("\n*Raw Object Read*\n");
+
+	/**
+	 * We can read raw objects directly from the object database if we have
+	 * the oid (SHA) of the object.  This allows us to access objects without
+	 * knowing their type and inspect the raw bytes unparsed.
+	 */
+	error = git_odb_read(&obj, odb, oid);
+	check_error(error, "finding object in repository");
+
+	/**
+	 * A raw object only has three properties - the type (commit, blob, tree
+	 * or tag), the size of the raw data and the raw, unparsed data itself.
+	 * For a commit or tag, that raw data is human readable plain ASCII
+	 * text. For a blob it is just file contents, so it could be text or
+	 * binary data. For a tree it is a special binary format, so it's unlikely
+	 * to be hugely helpful as a raw object.
+	 */
+	data = (const unsigned char *)git_odb_object_data(obj);
+	otype = git_odb_object_type(obj);
+
+	/**
+	 * We provide methods to convert from the object type which is an enum, to
+	 * a string representation of that value (and vice-versa).
+	 */
+	str_type = git_object_type2string(otype);
+	printf("object length and type: %d, %s\nobject data: %s\n",
+			(int)git_odb_object_size(obj),
+			str_type, data);
+
+	/**
+	 * For proper memory management, close the object when you are done with
+	 * it or it will leak memory.
+	 */
+	git_odb_object_free(obj);
+
+	/**
+	 * #### Raw Object Writing
+	 */
+
+	printf("\n*Raw Object Write*\n");
+
+	/**
+	 * You can also write raw object data to Git. This is pretty cool because
+	 * it gives you direct access to the key/value properties of Git.  Here
+	 * we'll write a new blob object that just contains a simple string.
+	 * Notice that we have to specify the object type as the `git_otype` enum.
+	 */
+	git_odb_write(oid, odb, "test data", sizeof("test data") - 1, GIT_OBJ_BLOB);
+
+	/**
+	 * Now that we've written the object, we can check out what SHA1 was
+	 * generated when the object was written to our database.
+	 */
+	git_oid_fmt(oid_hex, oid);
+	printf("Written Object: %s\n", oid_hex);
+
+	/**
+	 * Free the object database after usage.
+	 */
+	git_odb_free(odb);
+}
+
+/**
+ * #### Writing Commits
+ *
+ * libgit2 provides a couple of methods to create commit objects easily as
+ * well. There are four different create signatures, we'll just show one
+ * of them here.  You can read about the other ones in the [commit API
+ * docs][cd].
+ *
+ * [cd]: http://libgit2.github.com/libgit2/#HEAD/group/commit
+ */
+static void commit_writing(git_repository *repo)
+{
+	git_oid tree_id, parent_id, commit_id;
+	git_tree *tree;
+	git_commit *parent;
+	git_signature *author, *committer;
+	char oid_hex[GIT_OID_HEXSZ+1] = { 0 };
+
+	printf("\n*Commit Writing*\n");
+
+	/**
+	 * Creating signatures for an authoring identity and time is simple.  You
+	 * will need to do this to specify who created a commit and when.  Default
+	 * values for the name and email should be found in the `user.name` and
+	 * `user.email` configuration options.  See the `config` section of this
+	 * example file to see how to access config values.
+	 */
+	git_signature_new(&author,
+			"Scott Chacon", "schacon@gmail.com", 123456789, 60);
+	git_signature_new(&committer,
+			"Scott A Chacon", "scott@github.com", 987654321, 90);
+
+	/**
+	 * Commit objects need a tree to point to and optionally one or more
+	 * parents.  Here we're creating oid objects to create the commit with,
+	 * but you can also use
+	 */
+	git_oid_fromstr(&tree_id, "f60079018b664e4e79329a7ef9559c8d9e0378d1");
+	git_tree_lookup(&tree, repo, &tree_id);
+	git_oid_fromstr(&parent_id, "5b5b025afb0b4c913b4c338a42934a3863bf3644");
+	git_commit_lookup(&parent, repo, &parent_id);
+
+	/**
+	 * Here we actually create the commit object with a single call with all
+	 * the values we need to create the commit.  The SHA key is written to the
+	 * `commit_id` variable here.
+	 */
+	git_commit_create_v(
+			&commit_id, /* out id */
+			repo,
+			NULL, /* do not update the HEAD */
+			author,
+			committer,
+			NULL, /* use default message encoding */
+			"example commit",
+			tree,
+			1, parent);
+
+	/**
+	 * Now we can take a look at the commit SHA we've generated.
+	 */
+	git_oid_fmt(oid_hex, &commit_id);
+	printf("New Commit: %s\n", oid_hex);
+
+	/**
+	 * Free all objects used in the meanwhile.
+	 */
+	git_tree_free(tree);
+	git_commit_free(parent);
+	git_signature_free(author);
+	git_signature_free(committer);
+}
+
+/**
+ * ### Object Parsing
+ *
+ * libgit2 has methods to parse every object type in Git so you don't have
+ * to work directly with the raw data. This is much faster and simpler
+ * than trying to deal with the raw data yourself.
+ */
+
+/**
+ * #### Commit Parsing
+ *
+ * [Parsing commit objects][pco] is simple and gives you access to all the
+ * data in the commit - the author (name, email, datetime), committer
+ * (same), tree, message, encoding and parent(s).
+ *
+ * [pco]: http://libgit2.github.com/libgit2/#HEAD/group/commit
+ */
+static void commit_parsing(git_repository *repo)
+{
+	const git_signature *author, *cmtter;
+	git_commit *commit, *parent;
+	git_oid oid;
+	char oid_hex[GIT_OID_HEXSZ+1];
+	const char *message;
+	unsigned int parents, p;
+	int error;
+	time_t time;
+
+	printf("\n*Commit Parsing*\n");
+
+	git_oid_fromstr(&oid, "8496071c1b46c854b31185ea97743be6a8774479");
+
+	error = git_commit_lookup(&commit, repo, &oid);
+	check_error(error, "looking up commit");
+
+	/**
+	 * Each of the properties of the commit object are accessible via methods,
+	 * including commonly needed variations, such as `git_commit_time` which
+	 * returns the author time and `git_commit_message` which gives you the
+	 * commit message (as a NUL-terminated string).
+	 */
+	message  = git_commit_message(commit);
+	author   = git_commit_author(commit);
+	cmtter   = git_commit_committer(commit);
+	time    = git_commit_time(commit);
+
+	/**
+	 * The author and committer methods return [git_signature] structures,
+	 * which give you name, email and `when`, which is a `git_time` structure,
+	 * giving you a timestamp and timezone offset.
+	 */
+	printf("Author: %s (%s)\nCommitter: %s (%s)\nDate: %s\nMessage: %s\n",
+		author->name, author->email,
+		cmtter->name, cmtter->email,
+		ctime(&time), message);
+
+	/**
+	 * Commits can have zero or more parents. The first (root) commit will
+	 * have no parents, most commits will have one (i.e. the commit it was
+	 * based on) and merge commits will have two or more.  Commits can
+	 * technically have any number, though it's rare to have more than two.
+	 */
+	parents  = git_commit_parentcount(commit);
+	for (p = 0;p < parents;p++) {
+		memset(oid_hex, 0, sizeof(oid_hex));
+
+		git_commit_parent(&parent, commit, p);
+		git_oid_fmt(oid_hex, git_commit_id(parent));
+		printf("Parent: %s\n", oid_hex);
+		git_commit_free(parent);
+	}
+
+	git_commit_free(commit);
+}
+
+/**
+ * #### Tag Parsing
+ *
+ * You can parse and create tags with the [tag management API][tm], which
+ * functions very similarly to the commit lookup, parsing and creation
+ * methods, since the objects themselves are very similar.
+ *
+ * [tm]: http://libgit2.github.com/libgit2/#HEAD/group/tag
+ */
+static void tag_parsing(git_repository *repo)
+{
+	git_commit *commit;
+	git_otype type;
+	git_tag *tag;
+	git_oid oid;
+	const char *name, *message;
+	int error;
+
+	printf("\n*Tag Parsing*\n");
+
+	/**
+	 * We create an oid for the tag object if we know the SHA and look it up
+	 * the same way that we would a commit (or any other object).
+	 */
+	git_oid_fromstr(&oid, "b25fa35b38051e4ae45d4222e795f9df2e43f1d1");
+
+	error = git_tag_lookup(&tag, repo, &oid);
+	check_error(error, "looking up tag");
+
+	/**
+	 * Now that we have the tag object, we can extract the information it
+	 * generally contains: the target (usually a commit object), the type of
+	 * the target object (usually 'commit'), the name ('v1.0'), the tagger (a
+	 * git_signature - name, email, timestamp), and the tag message.
+	 */
+	git_tag_target((git_object **)&commit, tag);
+	name = git_tag_name(tag);		/* "test" */
+	type = git_tag_target_type(tag);	/* GIT_OBJ_COMMIT (otype enum) */
+	message = git_tag_message(tag);		/* "tag message\n" */
+	printf("Tag Name: %s\nTag Type: %s\nTag Message: %s\n",
+		name, git_object_type2string(type), message);
+
+	/**
+	 * Free both the commit and tag after usage.
+	 */
+	git_commit_free(commit);
+	git_tag_free(tag);
+}
+
+/**
+ * #### Tree Parsing
+ *
+ * [Tree parsing][tp] is a bit different than the other objects, in that
+ * we have a subtype which is the tree entry.  This is not an actual
+ * object type in Git, but a useful structure for parsing and traversing
+ * tree entries.
+ *
+ * [tp]: http://libgit2.github.com/libgit2/#HEAD/group/tree
+ */
+static void tree_parsing(git_repository *repo)
+{
+	const git_tree_entry *entry;
+	size_t cnt;
+	git_object *obj;
+	git_tree *tree;
+	git_oid oid;
+
+	printf("\n*Tree Parsing*\n");
+
+	/**
+	 * Create the oid and lookup the tree object just like the other objects.
+	 */
+	git_oid_fromstr(&oid, "f60079018b664e4e79329a7ef9559c8d9e0378d1");
+	git_tree_lookup(&tree, repo, &oid);
+
+	/**
+	 * Getting the count of entries in the tree so you can iterate over them
+	 * if you want to.
+	 */
+	cnt = git_tree_entrycount(tree); /* 2 */
+	printf("tree entries: %d\n", (int) cnt);
+
+	entry = git_tree_entry_byindex(tree, 0);
+	printf("Entry name: %s\n", git_tree_entry_name(entry)); /* "README" */
+
+	/**
+	 * You can also access tree entries by name if you know the name of the
+	 * entry you're looking for.
+	 */
+	entry = git_tree_entry_byname(tree, "README");
+	git_tree_entry_name(entry); /* "README" */
+
+	/**
+	 * Once you have the entry object, you can access the content or subtree
+	 * (or commit, in the case of submodules) that it points to.  You can also
+	 * get the mode if you want.
+	 */
+	git_tree_entry_to_object(&obj, repo, entry); /* blob */
+
+	/**
+	 * Remember to close the looked-up object and tree once you are done using it
+	 */
+	git_object_free(obj);
+	git_tree_free(tree);
+}
+
+/**
+ * #### Blob Parsing
+ *
+ * The last object type is the simplest and requires the least parsing
+ * help. Blobs are just file contents and can contain anything, there is
+ * no structure to it. The main advantage to using the [simple blob
+ * api][ba] is that when you're creating blobs you don't have to calculate
+ * the size of the content.  There is also a helper for reading a file
+ * from disk and writing it to the db and getting the oid back so you
+ * don't have to do all those steps yourself.
+ *
+ * [ba]: http://libgit2.github.com/libgit2/#HEAD/group/blob
+ */
+static void blob_parsing(git_repository *repo)
+{
+	git_blob *blob;
+	git_oid oid;
+
+	printf("\n*Blob Parsing*\n");
+
+	git_oid_fromstr(&oid, "1385f264afb75a56a5bec74243be9b367ba4ca08");
+	git_blob_lookup(&blob, repo, &oid);
+
+	/**
+	 * You can access a buffer with the raw contents of the blob directly.
+	 * Note that this buffer may not be contain ASCII data for certain blobs
+	 * (e.g. binary files): do not consider the buffer a NULL-terminated
+	 * string, and use the `git_blob_rawsize` attribute to find out its exact
+	 * size in bytes
+	 * */
+	printf("Blob Size: %ld\n", (long)git_blob_rawsize(blob)); /* 8 */
+	git_blob_rawcontent(blob); /* "content" */
+
+	/**
+	 * Free the blob after usage.
+	 */
+	git_blob_free(blob);
+}
+
+/**
+ * ### Revwalking
+ *
+ * The libgit2 [revision walking api][rw] provides methods to traverse the
+ * directed graph created by the parent pointers of the commit objects.
+ * Since all commits point back to the commit that came directly before
+ * them, you can walk this parentage as a graph and find all the commits
+ * that were ancestors of (reachable from) a given starting point.  This
+ * can allow you to create `git log` type functionality.
+ *
+ * [rw]: http://libgit2.github.com/libgit2/#HEAD/group/revwalk
+ */
+static void revwalking(git_repository *repo)
+{
+	const git_signature *cauth;
+	const char *cmsg;
+	int error;
+	git_revwalk *walk;
+	git_commit *wcommit;
+	git_oid oid;
+
+	printf("\n*Revwalking*\n");
+
+	git_oid_fromstr(&oid, "5b5b025afb0b4c913b4c338a42934a3863bf3644");
+
+	/**
+	 * To use the revwalker, create a new walker, tell it how you want to sort
+	 * the output and then push one or more starting points onto the walker.
+	 * If you want to emulate the output of `git log` you would push the SHA
+	 * of the commit that HEAD points to into the walker and then start
+	 * traversing them.  You can also 'hide' commits that you want to stop at
+	 * or not see any of their ancestors.  So if you want to emulate `git log
+	 * branch1..branch2`, you would push the oid of `branch2` and hide the oid
+	 * of `branch1`.
+	 */
+	git_revwalk_new(&walk, repo);
+	git_revwalk_sorting(walk, GIT_SORT_TOPOLOGICAL | GIT_SORT_REVERSE);
+	git_revwalk_push(walk, &oid);
+
+	/**
+	 * Now that we have the starting point pushed onto the walker, we start
+	 * asking for ancestors. It will return them in the sorting order we asked
+	 * for as commit oids.  We can then lookup and parse the committed pointed
+	 * at by the returned OID; note that this operation is specially fast
+	 * since the raw contents of the commit object will be cached in memory
+	 */
+	while ((git_revwalk_next(&oid, walk)) == 0) {
+		error = git_commit_lookup(&wcommit, repo, &oid);
+		check_error(error, "looking up commit during revwalk");
+
+		cmsg  = git_commit_message(wcommit);
+		cauth = git_commit_author(wcommit);
+		printf("%s (%s)\n", cmsg, cauth->email);
+
+		git_commit_free(wcommit);
+	}
+
+	/**
+	 * Like the other objects, be sure to free the revwalker when you're done
+	 * to prevent memory leaks.  Also, make sure that the repository being
+	 * walked it not deallocated while the walk is in progress, or it will
+	 * result in undefined behavior
+	 */
+	git_revwalk_free(walk);
+}
+
+/**
+ * ### Index File Manipulation *
+ * The [index file API][gi] allows you to read, traverse, update and write
+ * the Git index file (sometimes thought of as the staging area).
+ *
+ * [gi]: http://libgit2.github.com/libgit2/#HEAD/group/index
+ */
+static void index_walking(git_repository *repo)
+{
+	git_index *index;
+	unsigned int i, ecount;
+
+	printf("\n*Index Walking*\n");
+
+	/**
+	 * You can either open the index from the standard location in an open
+	 * repository, as we're doing here, or you can open and manipulate any
+	 * index file with `git_index_open_bare()`. The index for the repository
+	 * will be located and loaded from disk.
+	 */
+	git_repository_index(&index, repo);
+
+	/**
+	 * For each entry in the index, you can get a bunch of information
+	 * including the SHA (oid), path and mode which map to the tree objects
+	 * that are written out.  It also has filesystem properties to help
+	 * determine what to inspect for changes (ctime, mtime, dev, ino, uid,
+	 * gid, file_size and flags) All these properties are exported publicly in
+	 * the `git_index_entry` struct
+	 */
+	ecount = git_index_entrycount(index);
+	for (i = 0; i < ecount; ++i) {
+		const git_index_entry *e = git_index_get_byindex(index, i);
+
+		printf("path: %s\n", e->path);
+		printf("mtime: %d\n", (int)e->mtime.seconds);
+		printf("fs: %d\n", (int)e->file_size);
+	}
+
+	git_index_free(index);
+}
+
+/**
+ * ### References
+ *
+ * The [reference API][ref] allows you to list, resolve, create and update
+ * references such as branches, tags and remote references (everything in
+ * the .git/refs directory).
+ *
+ * [ref]: http://libgit2.github.com/libgit2/#HEAD/group/reference
+ */
+static void reference_listing(git_repository *repo)
+{
+	git_strarray ref_list;
+	unsigned i;
+
+	printf("\n*Reference Listing*\n");
+
+	/**
+	 * Here we will implement something like `git for-each-ref` simply listing
+	 * out all available references and the object SHA they resolve to.
+	 *
+	 * Now that we have the list of reference names, we can lookup each ref
+	 * one at a time and resolve them to the SHA, then print both values out.
+	 */
+
+	git_reference_list(&ref_list, repo);
+
+	for (i = 0; i < ref_list.count; ++i) {
+		git_reference *ref;
+		char oid_hex[GIT_OID_HEXSZ+1] = GIT_OID_HEX_ZERO;
+		const char *refname;
+
+		refname = ref_list.strings[i];
+		git_reference_lookup(&ref, repo, refname);
+
+		switch (git_reference_type(ref)) {
+			case GIT_REF_OID:
+				git_oid_fmt(oid_hex, git_reference_target(ref));
+				printf("%s [%s]\n", refname, oid_hex);
+				break;
+
+			case GIT_REF_SYMBOLIC:
+				printf("%s => %s\n", refname, git_reference_symbolic_target(ref));
+				break;
+			default:
+				fprintf(stderr, "Unexpected reference type\n");
+				exit(1);
+		}
+
+		git_reference_free(ref);
+	}
+
+	git_strarray_free(&ref_list);
+}
+
+/**
+ * ### Config Files
+ *
+ * The [config API][config] allows you to list and updatee config values
+ * in any of the accessible config file locations (system, global, local).
+ *
+ * [config]: http://libgit2.github.com/libgit2/#HEAD/group/config
+ */
+static void config_files(const char *repo_path, git_repository* repo)
+{
+	const char *email;
+	char config_path[256];
+	int32_t autocorrect;
+	git_config *cfg;
+	git_config *snap_cfg;
+	int error_code;
+
+	printf("\n*Config Listing*\n");
+
+	/**
+	 * Open a config object so we can read global values from it.
+	 */
+	sprintf(config_path, "%s/config", repo_path);
+	check_error(git_config_open_ondisk(&cfg, config_path), "opening config");
+
+	if (git_config_get_int32(&autocorrect, cfg, "help.autocorrect") == 0)
+		printf("Autocorrect: %d\n", autocorrect);
+
+	check_error(git_repository_config_snapshot(&snap_cfg, repo), "config snapshot");
+	git_config_get_string(&email, snap_cfg, "user.email");
+	printf("Email: %s\n", email);
+
+	error_code = git_config_get_int32(&autocorrect, cfg, "help.autocorrect");
+	switch (error_code)
+	{
+		case 0:
+			printf("Autocorrect: %d\n", autocorrect);
+			break;
+		case GIT_ENOTFOUND:
+			printf("Autocorrect: Undefined\n");
+			break;
+		default:
+			check_error(error_code, "get_int32 failed");
+	}
+	git_config_free(cfg);
+
+	check_error(git_repository_config_snapshot(&snap_cfg, repo), "config snapshot");
+	error_code = git_config_get_string(&email, snap_cfg, "user.email");
+	switch (error_code)
+	{
+		case 0:
+			printf("Email: %s\n", email);
+			break;
+		case GIT_ENOTFOUND:
+			printf("Email: Undefined\n");
+			break;
+		default:
+			check_error(error_code, "get_string failed");
+	}
+
+	git_config_free(snap_cfg);
+}

vendor/libgit2-sys/libgit2/examples/init.c

diff --git a/vendor/libgit2-sys/libgit2/examples/init.c b/vendor/libgit2-sys/libgit2/examples/init.c
new file mode 100644
index 0000000..fe7a672
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/init.c
@@ -0,0 +1,253 @@
+/*
+ * libgit2 "init" example - shows how to initialize a new repo
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include "common.h"
+
+/**
+ * This is a sample program that is similar to "git init".  See the
+ * documentation for that (try "git help init") to understand what this
+ * program is emulating.
+ *
+ * This demonstrates using the libgit2 APIs to initialize a new repository.
+ *
+ * This also contains a special additional option that regular "git init"
+ * does not support which is "--initial-commit" to make a first empty commit.
+ * That is demonstrated in the "create_initial_commit" helper function.
+ */
+
+/** Forward declarations of helpers */
+struct opts {
+	int no_options;
+	int quiet;
+	int bare;
+	int initial_commit;
+	uint32_t shared;
+	const char *template;
+	const char *gitdir;
+	const char *dir;
+};
+static void create_initial_commit(git_repository *repo);
+static void parse_opts(struct opts *o, int argc, char *argv[]);
+
+
+int main(int argc, char *argv[])
+{
+	git_repository *repo = NULL;
+	struct opts o = { 1, 0, 0, 0, GIT_REPOSITORY_INIT_SHARED_UMASK, 0, 0, 0 };
+
+	git_libgit2_init();
+
+	parse_opts(&o, argc, argv);
+
+	/* Initialize repository. */
+
+	if (o.no_options) {
+		/**
+		 * No options were specified, so let's demonstrate the default
+		 * simple case of git_repository_init() API usage...
+		 */
+		check_lg2(git_repository_init(&repo, o.dir, 0),
+			"Could not initialize repository", NULL);
+	}
+	else {
+		/**
+		 * Some command line options were specified, so we'll use the
+		 * extended init API to handle them
+		 */
+		git_repository_init_options initopts = GIT_REPOSITORY_INIT_OPTIONS_INIT;
+		initopts.flags = GIT_REPOSITORY_INIT_MKPATH;
+
+		if (o.bare)
+			initopts.flags |= GIT_REPOSITORY_INIT_BARE;
+
+		if (o.template) {
+			initopts.flags |= GIT_REPOSITORY_INIT_EXTERNAL_TEMPLATE;
+			initopts.template_path = o.template;
+		}
+
+		if (o.gitdir) {
+			/**
+			 * If you specified a separate git directory, then initialize
+			 * the repository at that path and use the second path as the
+			 * working directory of the repository (with a git-link file)
+			 */
+			initopts.workdir_path = o.dir;
+			o.dir = o.gitdir;
+		}
+
+		if (o.shared != 0)
+			initopts.mode = o.shared;
+
+		check_lg2(git_repository_init_ext(&repo, o.dir, &initopts),
+				"Could not initialize repository", NULL);
+	}
+
+	/** Print a message to stdout like "git init" does. */
+
+	if (!o.quiet) {
+		if (o.bare || o.gitdir)
+			o.dir = git_repository_path(repo);
+		else
+			o.dir = git_repository_workdir(repo);
+
+		printf("Initialized empty Git repository in %s\n", o.dir);
+	}
+
+	/**
+	 * As an extension to the basic "git init" command, this example
+	 * gives the option to create an empty initial commit.  This is
+	 * mostly to demonstrate what it takes to do that, but also some
+	 * people like to have that empty base commit in their repo.
+	 */
+	if (o.initial_commit) {
+		create_initial_commit(repo);
+		printf("Created empty initial commit\n");
+	}
+
+	git_repository_free(repo);
+	git_libgit2_shutdown();
+
+	return 0;
+}
+
+/**
+ * Unlike regular "git init", this example shows how to create an initial
+ * empty commit in the repository.  This is the helper function that does
+ * that.
+ */
+static void create_initial_commit(git_repository *repo)
+{
+	git_signature *sig;
+	git_index *index;
+	git_oid tree_id, commit_id;
+	git_tree *tree;
+
+	/** First use the config to initialize a commit signature for the user. */
+
+	if (git_signature_default(&sig, repo) < 0)
+		fatal("Unable to create a commit signature.",
+		      "Perhaps 'user.name' and 'user.email' are not set");
+
+	/* Now let's create an empty tree for this commit */
+
+	if (git_repository_index(&index, repo) < 0)
+		fatal("Could not open repository index", NULL);
+
+	/**
+	 * Outside of this example, you could call git_index_add_bypath()
+	 * here to put actual files into the index.  For our purposes, we'll
+	 * leave it empty for now.
+	 */
+
+	if (git_index_write_tree(&tree_id, index) < 0)
+		fatal("Unable to write initial tree from index", NULL);
+
+	git_index_free(index);
+
+	if (git_tree_lookup(&tree, repo, &tree_id) < 0)
+		fatal("Could not look up initial tree", NULL);
+
+	/**
+	 * Ready to create the initial commit.
+	 *
+	 * Normally creating a commit would involve looking up the current
+	 * HEAD commit and making that be the parent of the initial commit,
+	 * but here this is the first commit so there will be no parent.
+	 */
+
+	if (git_commit_create_v(
+			&commit_id, repo, "HEAD", sig, sig,
+			NULL, "Initial commit", tree, 0) < 0)
+		fatal("Could not create the initial commit", NULL);
+
+	/** Clean up so we don't leak memory. */
+
+	git_tree_free(tree);
+	git_signature_free(sig);
+}
+
+static void usage(const char *error, const char *arg)
+{
+	fprintf(stderr, "error: %s '%s'\n", error, arg);
+	fprintf(stderr,
+			"usage: init [-q | --quiet] [--bare] [--template=<dir>]\n"
+			"            [--shared[=perms]] [--initial-commit]\n"
+			"            [--separate-git-dir] <directory>\n");
+	exit(1);
+}
+
+/** Parse the tail of the --shared= argument. */
+static uint32_t parse_shared(const char *shared)
+{
+	if (!strcmp(shared, "false") || !strcmp(shared, "umask"))
+		return GIT_REPOSITORY_INIT_SHARED_UMASK;
+
+	else if (!strcmp(shared, "true") || !strcmp(shared, "group"))
+		return GIT_REPOSITORY_INIT_SHARED_GROUP;
+
+	else if (!strcmp(shared, "all") || !strcmp(shared, "world") ||
+			 !strcmp(shared, "everybody"))
+		return GIT_REPOSITORY_INIT_SHARED_ALL;
+
+	else if (shared[0] == '0') {
+		long val;
+		char *end = NULL;
+		val = strtol(shared + 1, &end, 8);
+		if (end == shared + 1 || *end != 0)
+			usage("invalid octal value for --shared", shared);
+		return (uint32_t)val;
+	}
+
+	else
+		usage("unknown value for --shared", shared);
+
+	return 0;
+}
+
+static void parse_opts(struct opts *o, int argc, char *argv[])
+{
+	struct args_info args = ARGS_INFO_INIT;
+	const char *sharedarg;
+
+	/** Process arguments. */
+
+	for (args.pos = 1; args.pos < argc; ++args.pos) {
+		char *a = argv[args.pos];
+
+		if (a[0] == '-')
+			o->no_options = 0;
+
+		if (a[0] != '-') {
+			if (o->dir != NULL)
+				usage("extra argument", a);
+			o->dir = a;
+		}
+		else if (!strcmp(a, "-q") || !strcmp(a, "--quiet"))
+			o->quiet = 1;
+		else if (!strcmp(a, "--bare"))
+			o->bare = 1;
+		else if (!strcmp(a, "--shared"))
+			o->shared = GIT_REPOSITORY_INIT_SHARED_GROUP;
+		else if (!strcmp(a, "--initial-commit"))
+			o->initial_commit = 1;
+		else if (match_str_arg(&sharedarg, &args, "--shared"))
+			o->shared = parse_shared(sharedarg);
+		else if (!match_str_arg(&o->template, &args, "--template") ||
+		         !match_str_arg(&o->gitdir, &args, "--separate-git-dir"))
+			usage("unknown option", a);
+	}
+
+	if (!o->dir)
+		usage("must specify directory to init", NULL);
+}

vendor/libgit2-sys/libgit2/examples/log.c

diff --git a/vendor/libgit2-sys/libgit2/examples/log.c b/vendor/libgit2-sys/libgit2/examples/log.c
new file mode 100644
index 0000000..a107470
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/log.c
@@ -0,0 +1,486 @@
+/*
+ * libgit2 "log" example - shows how to walk history and get commit info
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include "common.h"
+
+/**
+ * This example demonstrates the libgit2 rev walker APIs to roughly
+ * simulate the output of `git log` and a few of command line arguments.
+ * `git log` has many many options and this only shows a few of them.
+ *
+ * This does not have:
+ *
+ * - Robust error handling
+ * - Colorized or paginated output formatting
+ * - Most of the `git log` options
+ *
+ * This does have:
+ *
+ * - Examples of translating command line arguments to equivalent libgit2
+ *   revwalker configuration calls
+ * - Simplified options to apply pathspec limits and to show basic diffs
+ */
+
+/** log_state represents walker being configured while handling options */
+struct log_state {
+	git_repository *repo;
+	const char *repodir;
+	git_revwalk *walker;
+	int hide;
+	int sorting;
+	int revisions;
+};
+
+/** utility functions that are called to configure the walker */
+static void set_sorting(struct log_state *s, unsigned int sort_mode);
+static void push_rev(struct log_state *s, git_object *obj, int hide);
+static int add_revision(struct log_state *s, const char *revstr);
+
+/** log_options holds other command line options that affect log output */
+struct log_options {
+	int show_diff;
+	int show_log_size;
+	int skip, limit;
+	int min_parents, max_parents;
+	git_time_t before;
+	git_time_t after;
+	const char *author;
+	const char *committer;
+	const char *grep;
+};
+
+/** utility functions that parse options and help with log output */
+static int parse_options(
+	struct log_state *s, struct log_options *opt, int argc, char **argv);
+static void print_time(const git_time *intime, const char *prefix);
+static void print_commit(git_commit *commit, struct log_options *opts);
+static int match_with_parent(git_commit *commit, int i, git_diff_options *);
+
+/** utility functions for filtering */
+static int signature_matches(const git_signature *sig, const char *filter);
+static int log_message_matches(const git_commit *commit, const char *filter);
+
+int main(int argc, char *argv[])
+{
+	int i, count = 0, printed = 0, parents, last_arg;
+	struct log_state s;
+	struct log_options opt;
+	git_diff_options diffopts = GIT_DIFF_OPTIONS_INIT;
+	git_oid oid;
+	git_commit *commit = NULL;
+	git_pathspec *ps = NULL;
+
+	git_libgit2_init();
+
+	/** Parse arguments and set up revwalker. */
+
+	last_arg = parse_options(&s, &opt, argc, argv);
+
+	diffopts.pathspec.strings = &argv[last_arg];
+	diffopts.pathspec.count	  = argc - last_arg;
+	if (diffopts.pathspec.count > 0)
+		check_lg2(git_pathspec_new(&ps, &diffopts.pathspec),
+			"Building pathspec", NULL);
+
+	if (!s.revisions)
+		add_revision(&s, NULL);
+
+	/** Use the revwalker to traverse the history. */
+
+	printed = count = 0;
+
+	for (; !git_revwalk_next(&oid, s.walker); git_commit_free(commit)) {
+		check_lg2(git_commit_lookup(&commit, s.repo, &oid),
+			"Failed to look up commit", NULL);
+
+		parents = (int)git_commit_parentcount(commit);
+		if (parents < opt.min_parents)
+			continue;
+		if (opt.max_parents > 0 && parents > opt.max_parents)
+			continue;
+
+		if (diffopts.pathspec.count > 0) {
+			int unmatched = parents;
+
+			if (parents == 0) {
+				git_tree *tree;
+				check_lg2(git_commit_tree(&tree, commit), "Get tree", NULL);
+				if (git_pathspec_match_tree(
+						NULL, tree, GIT_PATHSPEC_NO_MATCH_ERROR, ps) != 0)
+					unmatched = 1;
+				git_tree_free(tree);
+			} else if (parents == 1) {
+				unmatched = match_with_parent(commit, 0, &diffopts) ? 0 : 1;
+			} else {
+				for (i = 0; i < parents; ++i) {
+					if (match_with_parent(commit, i, &diffopts))
+						unmatched--;
+				}
+			}
+
+			if (unmatched > 0)
+				continue;
+		}
+
+		if (!signature_matches(git_commit_author(commit), opt.author))
+			continue;
+
+		if (!signature_matches(git_commit_committer(commit), opt.committer))
+			continue;
+
+		if (!log_message_matches(commit, opt.grep))
+			continue;
+
+		if (count++ < opt.skip)
+			continue;
+		if (opt.limit != -1 && printed++ >= opt.limit) {
+			git_commit_free(commit);
+			break;
+		}
+
+		print_commit(commit, &opt);
+
+		if (opt.show_diff) {
+			git_tree *a = NULL, *b = NULL;
+			git_diff *diff = NULL;
+
+			if (parents > 1)
+				continue;
+			check_lg2(git_commit_tree(&b, commit), "Get tree", NULL);
+			if (parents == 1) {
+				git_commit *parent;
+				check_lg2(git_commit_parent(&parent, commit, 0), "Get parent", NULL);
+				check_lg2(git_commit_tree(&a, parent), "Tree for parent", NULL);
+				git_commit_free(parent);
+			}
+
+			check_lg2(git_diff_tree_to_tree(
+				&diff, git_commit_owner(commit), a, b, &diffopts),
+				"Diff commit with parent", NULL);
+			check_lg2(
+                git_diff_print(diff, GIT_DIFF_FORMAT_PATCH, diff_output, NULL),
+				"Displaying diff", NULL);
+
+			git_diff_free(diff);
+			git_tree_free(a);
+			git_tree_free(b);
+		}
+	}
+
+	git_pathspec_free(ps);
+	git_revwalk_free(s.walker);
+	git_repository_free(s.repo);
+	git_libgit2_shutdown();
+
+	return 0;
+}
+
+/** Determine if the given git_signature does not contain the filter text. */
+static int signature_matches(const git_signature *sig, const char *filter) {
+	if (filter == NULL)
+		return 1;
+
+	if (sig != NULL &&
+		(strstr(sig->name, filter) != NULL ||
+		strstr(sig->email, filter) != NULL))
+		return 1;
+
+	return 0;
+}
+
+static int log_message_matches(const git_commit *commit, const char *filter) {
+	const char *message = NULL;
+
+	if (filter == NULL)
+		return 1;
+
+	if ((message = git_commit_message(commit)) != NULL &&
+		strstr(message, filter) != NULL)
+		return 1;
+
+	return 0;
+}
+
+/** Push object (for hide or show) onto revwalker. */
+static void push_rev(struct log_state *s, git_object *obj, int hide)
+{
+	hide = s->hide ^ hide;
+
+	/** Create revwalker on demand if it doesn't already exist. */
+	if (!s->walker) {
+		check_lg2(git_revwalk_new(&s->walker, s->repo),
+			"Could not create revision walker", NULL);
+		git_revwalk_sorting(s->walker, s->sorting);
+	}
+
+	if (!obj)
+		check_lg2(git_revwalk_push_head(s->walker),
+			"Could not find repository HEAD", NULL);
+	else if (hide)
+		check_lg2(git_revwalk_hide(s->walker, git_object_id(obj)),
+			"Reference does not refer to a commit", NULL);
+	else
+		check_lg2(git_revwalk_push(s->walker, git_object_id(obj)),
+			"Reference does not refer to a commit", NULL);
+
+	git_object_free(obj);
+}
+
+/** Parse revision string and add revs to walker. */
+static int add_revision(struct log_state *s, const char *revstr)
+{
+	git_revspec revs;
+	int hide = 0;
+
+	/** Open repo on demand if it isn't already open. */
+	if (!s->repo) {
+		if (!s->repodir) s->repodir = ".";
+		check_lg2(git_repository_open_ext(&s->repo, s->repodir, 0, NULL),
+			"Could not open repository", s->repodir);
+	}
+
+	if (!revstr) {
+		push_rev(s, NULL, hide);
+		return 0;
+	}
+
+	if (*revstr == '^') {
+		revs.flags = GIT_REVPARSE_SINGLE;
+		hide = !hide;
+
+		if (git_revparse_single(&revs.from, s->repo, revstr + 1) < 0)
+			return -1;
+	} else if (git_revparse(&revs, s->repo, revstr) < 0)
+		return -1;
+
+	if ((revs.flags & GIT_REVPARSE_SINGLE) != 0)
+		push_rev(s, revs.from, hide);
+	else {
+		push_rev(s, revs.to, hide);
+
+		if ((revs.flags & GIT_REVPARSE_MERGE_BASE) != 0) {
+			git_oid base;
+			check_lg2(git_merge_base(&base, s->repo,
+				git_object_id(revs.from), git_object_id(revs.to)),
+				"Could not find merge base", revstr);
+			check_lg2(
+				git_object_lookup(&revs.to, s->repo, &base, GIT_OBJ_COMMIT),
+				"Could not find merge base commit", NULL);
+
+			push_rev(s, revs.to, hide);
+		}
+
+		push_rev(s, revs.from, !hide);
+	}
+
+	return 0;
+}
+
+/** Update revwalker with sorting mode. */
+static void set_sorting(struct log_state *s, unsigned int sort_mode)
+{
+	/** Open repo on demand if it isn't already open. */
+	if (!s->repo) {
+		if (!s->repodir) s->repodir = ".";
+		check_lg2(git_repository_open_ext(&s->repo, s->repodir, 0, NULL),
+			"Could not open repository", s->repodir);
+	}
+
+	/** Create revwalker on demand if it doesn't already exist. */
+	if (!s->walker)
+		check_lg2(git_revwalk_new(&s->walker, s->repo),
+			"Could not create revision walker", NULL);
+
+	if (sort_mode == GIT_SORT_REVERSE)
+		s->sorting = s->sorting ^ GIT_SORT_REVERSE;
+	else
+		s->sorting = sort_mode | (s->sorting & GIT_SORT_REVERSE);
+
+	git_revwalk_sorting(s->walker, s->sorting);
+}
+
+/** Helper to format a git_time value like Git. */
+static void print_time(const git_time *intime, const char *prefix)
+{
+	char sign, out[32];
+	struct tm *intm;
+	int offset, hours, minutes;
+	time_t t;
+
+	offset = intime->offset;
+	if (offset < 0) {
+		sign = '-';
+		offset = -offset;
+	} else {
+		sign = '+';
+	}
+
+	hours   = offset / 60;
+	minutes = offset % 60;
+
+	t = (time_t)intime->time + (intime->offset * 60);
+
+	intm = gmtime(&t);
+	strftime(out, sizeof(out), "%a %b %e %T %Y", intm);
+
+	printf("%s%s %c%02d%02d\n", prefix, out, sign, hours, minutes);
+}
+
+/** Helper to print a commit object. */
+static void print_commit(git_commit *commit, struct log_options *opts)
+{
+	char buf[GIT_OID_HEXSZ + 1];
+	int i, count;
+	const git_signature *sig;
+	const char *scan, *eol;
+
+	git_oid_tostr(buf, sizeof(buf), git_commit_id(commit));
+	printf("commit %s\n", buf);
+
+	if (opts->show_log_size) {
+		printf("log size %d\n", (int)strlen(git_commit_message(commit)));
+	}
+
+	if ((count = (int)git_commit_parentcount(commit)) > 1) {
+		printf("Merge:");
+		for (i = 0; i < count; ++i) {
+			git_oid_tostr(buf, 8, git_commit_parent_id(commit, i));
+			printf(" %s", buf);
+		}
+		printf("\n");
+	}
+
+	if ((sig = git_commit_author(commit)) != NULL) {
+		printf("Author: %s <%s>\n", sig->name, sig->email);
+		print_time(&sig->when, "Date:   ");
+	}
+	printf("\n");
+
+	for (scan = git_commit_message(commit); scan && *scan; ) {
+		for (eol = scan; *eol && *eol != '\n'; ++eol) /* find eol */;
+
+		printf("    %.*s\n", (int)(eol - scan), scan);
+		scan = *eol ? eol + 1 : NULL;
+	}
+	printf("\n");
+}
+
+/** Helper to find how many files in a commit changed from its nth parent. */
+static int match_with_parent(git_commit *commit, int i, git_diff_options *opts)
+{
+	git_commit *parent;
+	git_tree *a, *b;
+	git_diff *diff;
+	int ndeltas;
+
+	check_lg2(
+		git_commit_parent(&parent, commit, (size_t)i), "Get parent", NULL);
+	check_lg2(git_commit_tree(&a, parent), "Tree for parent", NULL);
+	check_lg2(git_commit_tree(&b, commit), "Tree for commit", NULL);
+	check_lg2(
+		git_diff_tree_to_tree(&diff, git_commit_owner(commit), a, b, opts),
+		"Checking diff between parent and commit", NULL);
+
+	ndeltas = (int)git_diff_num_deltas(diff);
+
+	git_diff_free(diff);
+	git_tree_free(a);
+	git_tree_free(b);
+	git_commit_free(parent);
+
+	return ndeltas > 0;
+}
+
+/** Print a usage message for the program. */
+static void usage(const char *message, const char *arg)
+{
+	if (message && arg)
+		fprintf(stderr, "%s: %s\n", message, arg);
+	else if (message)
+		fprintf(stderr, "%s\n", message);
+	fprintf(stderr, "usage: log [<options>]\n");
+	exit(1);
+}
+
+/** Parse some log command line options. */
+static int parse_options(
+	struct log_state *s, struct log_options *opt, int argc, char **argv)
+{
+	struct args_info args = ARGS_INFO_INIT;
+
+	memset(s, 0, sizeof(*s));
+	s->sorting = GIT_SORT_TIME;
+
+	memset(opt, 0, sizeof(*opt));
+	opt->max_parents = -1;
+	opt->limit = -1;
+
+	for (args.pos = 1; args.pos < argc; ++args.pos) {
+		const char *a = argv[args.pos];
+
+		if (a[0] != '-') {
+			if (!add_revision(s, a))
+				s->revisions++;
+			else
+				/** Try failed revision parse as filename. */
+				break;
+		} else if (!strcmp(a, "--")) {
+			++args.pos;
+			break;
+		}
+		else if (!strcmp(a, "--date-order"))
+			set_sorting(s, GIT_SORT_TIME);
+		else if (!strcmp(a, "--topo-order"))
+			set_sorting(s, GIT_SORT_TOPOLOGICAL);
+		else if (!strcmp(a, "--reverse"))
+			set_sorting(s, GIT_SORT_REVERSE);
+		else if (match_str_arg(&opt->author, &args, "--author"))
+			/** Found valid --author */;
+		else if (match_str_arg(&opt->committer, &args, "--committer"))
+			/** Found valid --committer */;
+		else if (match_str_arg(&opt->grep, &args, "--grep"))
+			/** Found valid --grep */;
+		else if (match_str_arg(&s->repodir, &args, "--git-dir"))
+			/** Found git-dir. */;
+		else if (match_int_arg(&opt->skip, &args, "--skip", 0))
+			/** Found valid --skip. */;
+		else if (match_int_arg(&opt->limit, &args, "--max-count", 0))
+			/** Found valid --max-count. */;
+		else if (a[1] >= '0' && a[1] <= '9')
+			is_integer(&opt->limit, a + 1, 0);
+		else if (match_int_arg(&opt->limit, &args, "-n", 0))
+			/** Found valid -n. */;
+		else if (!strcmp(a, "--merges"))
+			opt->min_parents = 2;
+		else if (!strcmp(a, "--no-merges"))
+			opt->max_parents = 1;
+		else if (!strcmp(a, "--no-min-parents"))
+			opt->min_parents = 0;
+		else if (!strcmp(a, "--no-max-parents"))
+			opt->max_parents = -1;
+		else if (match_int_arg(&opt->max_parents, &args, "--max-parents=", 1))
+			/** Found valid --max-parents. */;
+		else if (match_int_arg(&opt->min_parents, &args, "--min-parents=", 0))
+			/** Found valid --min_parents. */;
+		else if (!strcmp(a, "-p") || !strcmp(a, "-u") || !strcmp(a, "--patch"))
+			opt->show_diff = 1;
+		else if (!strcmp(a, "--log-size"))
+			opt->show_log_size = 1;
+		else
+			usage("Unsupported argument", a);
+	}
+
+	return args.pos;
+}
+

vendor/libgit2-sys/libgit2/examples/ls-files.c

diff --git a/vendor/libgit2-sys/libgit2/examples/ls-files.c b/vendor/libgit2-sys/libgit2/examples/ls-files.c
new file mode 100644
index 0000000..98c89c9
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/ls-files.c
@@ -0,0 +1,140 @@
+/*
+ * libgit2 "ls-files" example - shows how to view all files currently in the index
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include "common.h"
+#include "array.h"
+
+/**
+ * This example demonstrates the libgit2 index APIs to roughly
+ * simulate the output of `git ls-files`.
+ * `git ls-files` has many options and this currently does not show them.
+ *
+ * `git ls-files` base command shows all paths in the index at that time.
+ * This includes staged and committed files, but unstaged files will not display.
+ *
+ * This currently supports the default behavior and the `--error-unmatch` option.
+ */
+
+typedef struct {
+	int error_unmatch;
+	char *files[1024];
+	size_t file_count;
+} ls_options;
+
+static void usage(const char *message, const char *arg)
+{
+	if (message && arg)
+		fprintf(stderr, "%s: %s\n", message, arg);
+	else if (message)
+		fprintf(stderr, "%s\n", message);
+	fprintf(stderr, "usage: ls-files [--error-unmatch] [--] [<file>...]\n");
+	exit(1);
+}
+
+static int parse_options(ls_options *opts, int argc, char *argv[])
+{
+	int parsing_files = 0;
+	int i;
+
+	memset(opts, 0, sizeof(ls_options));
+
+	if (argc < 2)
+		return 0;
+
+	for (i = 1; i < argc; ++i) {
+		char *a = argv[i];
+
+		/* if it doesn't start with a '-' or is after the '--' then it is a file */
+		if (a[0] != '-' || parsing_files) {
+			parsing_files = 1;
+
+			/* watch for overflows (just in case) */
+			if (opts->file_count == 1024) {
+				fprintf(stderr, "ls-files can only support 1024 files at this time.\n");
+				return -1;
+			}
+
+			opts->files[opts->file_count++] = a;
+		} else if (!strcmp(a, "--")) {
+			parsing_files = 1;
+		} else if (!strcmp(a, "--error-unmatch")) {
+			opts->error_unmatch = 1;
+		} else {
+			usage("Unsupported argument", a);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+static int print_paths(ls_options *opts, git_index *index)
+{
+	size_t i;
+	const git_index_entry *entry;
+
+	/* if there are no files explicitly listed by the user print all entries in the index */
+	if (opts->file_count == 0) {
+		size_t entry_count = git_index_entrycount(index);
+
+		for (i = 0; i < entry_count; i++) {
+			entry = git_index_get_byindex(index, i);
+			puts(entry->path);
+		}
+		return 0;
+	}
+
+	/* loop through the files found in the args and print them if they exist */
+	for (i = 0; i < opts->file_count; ++i) {
+		const char *path = opts->files[i];
+
+		if ((entry = git_index_get_bypath(index, path, GIT_INDEX_STAGE_NORMAL)) != NULL) {
+			puts(path);
+		} else if (opts->error_unmatch) {
+			fprintf(stderr, "error: pathspec '%s' did not match any file(s) known to git.\n", path);
+			fprintf(stderr, "Did you forget to 'git add'?\n");
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	ls_options opts;
+	git_repository *repo = NULL;
+	git_index *index = NULL;
+	int error;
+
+	if ((error = parse_options(&opts, argc, argv)) < 0)
+		return error;
+
+	git_libgit2_init();
+
+	if ((error = git_repository_open_ext(&repo, ".", 0, NULL)) < 0)
+		goto cleanup;
+
+	if ((error = git_repository_index(&index, repo)) < 0)
+		goto cleanup;
+
+	error = print_paths(&opts, index);
+
+cleanup:
+	git_index_free(index);
+	git_repository_free(repo);
+	git_libgit2_shutdown();
+
+	return error;
+}

vendor/libgit2-sys/libgit2/examples/merge.c

diff --git a/vendor/libgit2-sys/libgit2/examples/merge.c b/vendor/libgit2-sys/libgit2/examples/merge.c
new file mode 100644
index 0000000..59982cb
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/merge.c
@@ -0,0 +1,396 @@
+/*
+ * libgit2 "merge" example - shows how to perform merges
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include "common.h"
+#include <assert.h>
+
+#ifdef _MSC_VER
+#define snprintf sprintf_s
+#endif
+
+/** The following example demonstrates how to do merges with libgit2.
+ *
+ * It will merge whatever commit-ish you pass in into the current branch.
+ *
+ * Recognized options are :
+ *  --no-commit: don't actually commit the merge.
+ *
+ */
+
+typedef struct {
+	const char **heads;
+	size_t heads_count;
+
+	git_annotated_commit **annotated;
+	size_t annotated_count;
+
+	int no_commit : 1;
+} merge_options;
+
+static void print_usage(void)
+{
+	fprintf(stderr, "usage: merge [--no-commit] <commit...>\n");
+	exit(1);
+}
+
+static void merge_options_init(merge_options *opts)
+{
+	memset(opts, 0, sizeof(*opts));
+
+	opts->heads = NULL;
+	opts->heads_count = 0;
+	opts->annotated = NULL;
+	opts->annotated_count = 0;
+}
+
+static void opts_add_refish(merge_options *opts, const char *refish)
+{
+	size_t sz;
+
+	assert(opts != NULL);
+
+	sz = ++opts->heads_count * sizeof(opts->heads[0]);
+	opts->heads = xrealloc(opts->heads, sz);
+	opts->heads[opts->heads_count - 1] = refish;
+}
+
+static void parse_options(const char **repo_path, merge_options *opts, int argc, char **argv)
+{
+	struct args_info args = ARGS_INFO_INIT;
+
+	if (argc <= 1)
+		print_usage();
+
+	for (args.pos = 1; args.pos < argc; ++args.pos) {
+		const char *curr = argv[args.pos];
+
+		if (curr[0] != '-') {
+			opts_add_refish(opts, curr);
+		} else if (!strcmp(curr, "--no-commit")) {
+			opts->no_commit = 1;
+		} else if (match_str_arg(repo_path, &args, "--git-dir")) {
+			continue;
+		} else {
+			print_usage();
+		}
+	}
+}
+
+static int resolve_refish(git_annotated_commit **commit, git_repository *repo, const char *refish)
+{
+	git_reference *ref;
+	int err = 0;
+	git_oid oid;
+
+	assert(commit != NULL);
+
+	err = git_reference_dwim(&ref, repo, refish);
+	if (err == GIT_OK) {
+		git_annotated_commit_from_ref(commit, repo, ref);
+		git_reference_free(ref);
+		return 0;
+	}
+
+	err = git_oid_fromstr(&oid, refish);
+	if (err == GIT_OK) {
+		err = git_annotated_commit_lookup(commit, repo, &oid);
+	}
+
+	return err;
+}
+
+static int resolve_heads(git_repository *repo, merge_options *opts)
+{
+	git_annotated_commit **annotated = calloc(opts->heads_count, sizeof(git_annotated_commit *));
+	size_t annotated_count = 0, i;
+	int err = 0;
+
+	for (i = 0; i < opts->heads_count; i++) {
+		err = resolve_refish(&annotated[annotated_count++], repo, opts->heads[i]);
+		if (err != 0) {
+			fprintf(stderr, "failed to resolve refish %s: %s\n", opts->heads[i], giterr_last()->message);
+			annotated_count--;
+			continue;
+		}
+	}
+
+	if (annotated_count != opts->heads_count) {
+		fprintf(stderr, "unable to parse some refish\n");
+		free(annotated);
+		return -1;
+	}
+
+	opts->annotated = annotated;
+	opts->annotated_count = annotated_count;
+	return 0;
+}
+
+static int perform_fastforward(git_repository *repo, const git_oid *target_oid, int is_unborn)
+{
+	git_checkout_options ff_checkout_options = GIT_CHECKOUT_OPTIONS_INIT;
+	git_reference *target_ref;
+	git_reference *new_target_ref;
+	git_object *target = NULL;
+	int err = 0;
+
+	if (is_unborn) {
+		const char *symbolic_ref;
+		git_reference *head_ref;
+
+		/* HEAD reference is unborn, lookup manually so we don't try to resolve it */
+		err = git_reference_lookup(&head_ref, repo, "HEAD");
+		if (err != 0) {
+			fprintf(stderr, "failed to lookup HEAD ref\n");
+			return -1;
+		}
+
+		/* Grab the reference HEAD should be pointing to */
+		symbolic_ref = git_reference_symbolic_target(head_ref);
+
+		/* Create our master reference on the target OID */
+		err = git_reference_create(&target_ref, repo, symbolic_ref, target_oid, 0, NULL);
+		if (err != 0) {
+			fprintf(stderr, "failed to create master reference\n");
+			return -1;
+		}
+
+		git_reference_free(head_ref);
+	} else {
+		/* HEAD exists, just lookup and resolve */
+		err = git_repository_head(&target_ref, repo);
+		if (err != 0) {
+			fprintf(stderr, "failed to get HEAD reference\n");
+			return -1;
+		}
+	}
+
+	/* Lookup the target object */
+	err = git_object_lookup(&target, repo, target_oid, GIT_OBJ_COMMIT);
+	if (err != 0) {
+		fprintf(stderr, "failed to lookup OID %s\n", git_oid_tostr_s(target_oid));
+		return -1;
+	}
+
+	/* Checkout the result so the workdir is in the expected state */
+	ff_checkout_options.checkout_strategy = GIT_CHECKOUT_SAFE;
+	err = git_checkout_tree(repo, target, &ff_checkout_options);
+	if (err != 0) {
+		fprintf(stderr, "failed to checkout HEAD reference\n");
+		return -1;
+	}
+
+	/* Move the target reference to the target OID */
+	err = git_reference_set_target(&new_target_ref, target_ref, target_oid, NULL);
+	if (err != 0) {
+		fprintf(stderr, "failed to move HEAD reference\n");
+		return -1;
+	}
+
+	git_reference_free(target_ref);
+	git_reference_free(new_target_ref);
+	git_object_free(target);
+
+	return 0;
+}
+
+static void output_conflicts(git_index *index)
+{
+	git_index_conflict_iterator *conflicts;
+	const git_index_entry *ancestor;
+	const git_index_entry *our;
+	const git_index_entry *their;
+	int err = 0;
+
+	check_lg2(git_index_conflict_iterator_new(&conflicts, index), "failed to create conflict iterator", NULL);
+
+	while ((err = git_index_conflict_next(&ancestor, &our, &their, conflicts)) == 0) {
+		fprintf(stderr, "conflict: a:%s o:%s t:%s\n",
+		        ancestor ? ancestor->path : "NULL",
+		        our->path ? our->path : "NULL",
+		        their->path ? their->path : "NULL");
+	}
+
+	if (err != GIT_ITEROVER) {
+		fprintf(stderr, "error iterating conflicts\n");
+	}
+
+	git_index_conflict_iterator_free(conflicts);
+}
+
+static int create_merge_commit(git_repository *repo, git_index *index, merge_options *opts)
+{
+	git_oid tree_oid, commit_oid;
+	git_tree *tree;
+	git_signature *sign;
+	git_reference *merge_ref = NULL;
+	git_annotated_commit *merge_commit;
+	git_reference *head_ref;
+	git_commit **parents = calloc(opts->annotated_count + 1, sizeof(git_commit *));
+	const char *msg_target = NULL;
+	size_t msglen = 0;
+	char *msg;
+	size_t i;
+	int err;
+
+	/* Grab our needed references */
+	check_lg2(git_repository_head(&head_ref, repo), "failed to get repo HEAD", NULL);
+	if (resolve_refish(&merge_commit, repo, opts->heads[0])) {
+		fprintf(stderr, "failed to resolve refish %s", opts->heads[0]);
+		return -1;
+	}
+
+	/* Maybe that's a ref, so DWIM it */
+	err = git_reference_dwim(&merge_ref, repo, opts->heads[0]);
+	check_lg2(err, "failed to DWIM reference", giterr_last()->message);
+
+	/* Grab a signature */
+	check_lg2(git_signature_now(&sign, "Me", "me@example.com"), "failed to create signature", NULL);
+
+#define MERGE_COMMIT_MSG "Merge %s '%s'"
+	/* Prepare a standard merge commit message */
+	if (merge_ref != NULL) {
+		check_lg2(git_branch_name(&msg_target, merge_ref), "failed to get branch name of merged ref", NULL);
+	} else {
+		msg_target = git_oid_tostr_s(git_annotated_commit_id(merge_commit));
+	}
+
+	msglen = snprintf(NULL, 0, MERGE_COMMIT_MSG, (merge_ref ? "branch" : "commit"), msg_target);
+	if (msglen > 0) msglen++;
+	msg = malloc(msglen);
+	err = snprintf(msg, msglen, MERGE_COMMIT_MSG, (merge_ref ? "branch" : "commit"), msg_target);
+
+	/* This is only to silence the compiler */
+	if (err < 0) goto cleanup;
+
+	/* Setup our parent commits */
+	err = git_reference_peel((git_object **)&parents[0], head_ref, GIT_OBJ_COMMIT);
+	check_lg2(err, "failed to peel head reference", NULL);
+	for (i = 0; i < opts->annotated_count; i++) {
+		git_commit_lookup(&parents[i + 1], repo, git_annotated_commit_id(opts->annotated[i]));
+	}
+
+	/* Prepare our commit tree */
+	check_lg2(git_index_write_tree(&tree_oid, index), "failed to write merged tree", NULL);
+	check_lg2(git_tree_lookup(&tree, repo, &tree_oid), "failed to lookup tree", NULL);
+
+	/* Commit time ! */
+	err = git_commit_create(&commit_oid,
+	                        repo, git_reference_name(head_ref),
+	                        sign, sign,
+	                        NULL, msg,
+	                        tree,
+	                        opts->annotated_count + 1, (const git_commit **)parents);
+	check_lg2(err, "failed to create commit", NULL);
+
+	/* We're done merging, cleanup the repository state */
+	git_repository_state_cleanup(repo);
+
+cleanup:
+	free(parents);
+	return err;
+}
+
+int main(int argc, char **argv)
+{
+	git_repository *repo = NULL;
+	merge_options opts;
+	git_index *index;
+	git_repository_state_t state;
+	git_merge_analysis_t analysis;
+	git_merge_preference_t preference;
+	const char *path = ".";
+	int err = 0;
+
+	merge_options_init(&opts);
+	parse_options(&path, &opts, argc, argv);
+
+	git_libgit2_init();
+
+	check_lg2(git_repository_open_ext(&repo, path, 0, NULL),
+	          "Could not open repository", NULL);
+
+	state = git_repository_state(repo);
+	if (state != GIT_REPOSITORY_STATE_NONE) {
+		fprintf(stderr, "repository is in unexpected state %d\n", state);
+		goto cleanup;
+	}
+
+	err = resolve_heads(repo, &opts);
+	if (err != 0)
+		goto cleanup;
+
+	err = git_merge_analysis(&analysis, &preference,
+	                         repo,
+	                         (const git_annotated_commit **)opts.annotated,
+	                         opts.annotated_count);
+	check_lg2(err, "merge analysis failed", NULL);
+
+	if (analysis & GIT_MERGE_ANALYSIS_UP_TO_DATE) {
+		printf("Already up-to-date\n");
+		return 0;
+	} else if (analysis & GIT_MERGE_ANALYSIS_UNBORN ||
+	          (analysis & GIT_MERGE_ANALYSIS_FASTFORWARD &&
+	          !(preference & GIT_MERGE_PREFERENCE_NO_FASTFORWARD))) {
+		const git_oid *target_oid;
+		if (analysis & GIT_MERGE_ANALYSIS_UNBORN) {
+			printf("Unborn\n");
+		} else {
+			printf("Fast-forward\n");
+		}
+
+		/* Since this is a fast-forward, there can be only one merge head */
+		target_oid = git_annotated_commit_id(opts.annotated[0]);
+		assert(opts.annotated_count == 1);
+
+		return perform_fastforward(repo, target_oid, (analysis & GIT_MERGE_ANALYSIS_UNBORN));
+	} else if (analysis & GIT_MERGE_ANALYSIS_NORMAL) {
+		git_merge_options merge_opts = GIT_MERGE_OPTIONS_INIT;
+		git_checkout_options checkout_opts = GIT_CHECKOUT_OPTIONS_INIT;
+
+		merge_opts.flags = 0;
+		merge_opts.file_flags = GIT_MERGE_FILE_STYLE_DIFF3;
+
+		checkout_opts.checkout_strategy = GIT_CHECKOUT_FORCE|GIT_CHECKOUT_ALLOW_CONFLICTS;
+
+		if (preference & GIT_MERGE_PREFERENCE_FASTFORWARD_ONLY) {
+			printf("Fast-forward is preferred, but only a merge is possible\n");
+			return -1;
+		}
+
+		err = git_merge(repo,
+		                (const git_annotated_commit **)opts.annotated, opts.annotated_count,
+		                &merge_opts, &checkout_opts);
+		check_lg2(err, "merge failed", NULL);
+	}
+
+	/* If we get here, we actually performed the merge above */
+
+	check_lg2(git_repository_index(&index, repo), "failed to get repository index", NULL);
+
+	if (git_index_has_conflicts(index)) {
+		/* Handle conflicts */
+		output_conflicts(index);
+	} else if (!opts.no_commit) {
+		create_merge_commit(repo, index, &opts);
+		printf("Merge made\n");
+	}
+
+cleanup:
+	free(opts.heads);
+	free(opts.annotated);
+	git_repository_free(repo);
+	git_libgit2_shutdown();
+
+	return 0;
+}

vendor/libgit2-sys/libgit2/examples/network/Makefile

diff --git a/vendor/libgit2-sys/libgit2/examples/network/Makefile b/vendor/libgit2-sys/libgit2/examples/network/Makefile
new file mode 100644
index 0000000..f65c6cb
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/network/Makefile
@@ -0,0 +1,22 @@
+default: all
+
+CC = gcc
+CFLAGS += -g
+CFLAGS += -I../../include
+LDFLAGS += -L../../build -L../..
+LIBRARIES += -lgit2 -lpthread
+
+OBJECTS = \
+  git2.o \
+  ls-remote.o \
+  fetch.o \
+  clone.o \
+  index-pack.o \
+  common.o
+
+all: $(OBJECTS)
+	$(CC) $(CFLAGS) $(LDFLAGS) -o git2 $(OBJECTS) $(LIBRARIES)
+
+clean:
+	$(RM) $(OBJECTS)
+	$(RM) git2

vendor/libgit2-sys/libgit2/examples/network/clone.c

diff --git a/vendor/libgit2-sys/libgit2/examples/network/clone.c b/vendor/libgit2-sys/libgit2/examples/network/clone.c
new file mode 100644
index 0000000..540000b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/network/clone.c
@@ -0,0 +1,113 @@
+#include "common.h"
+#include <git2.h>
+#include <git2/clone.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#ifndef _WIN32
+# include <pthread.h>
+# include <unistd.h>
+#endif
+
+typedef struct progress_data {
+	git_transfer_progress fetch_progress;
+	size_t completed_steps;
+	size_t total_steps;
+	const char *path;
+} progress_data;
+
+static void print_progress(const progress_data *pd)
+{
+	int network_percent = pd->fetch_progress.total_objects > 0 ?
+		(100*pd->fetch_progress.received_objects) / pd->fetch_progress.total_objects :
+		0;
+	int index_percent = pd->fetch_progress.total_objects > 0 ?
+		(100*pd->fetch_progress.indexed_objects) / pd->fetch_progress.total_objects :
+		0;
+
+	int checkout_percent = pd->total_steps > 0
+		? (100 * pd->completed_steps) / pd->total_steps
+		: 0;
+	int kbytes = pd->fetch_progress.received_bytes / 1024;
+
+	if (pd->fetch_progress.total_objects &&
+		pd->fetch_progress.received_objects == pd->fetch_progress.total_objects) {
+		printf("Resolving deltas %d/%d\r",
+		       pd->fetch_progress.indexed_deltas,
+		       pd->fetch_progress.total_deltas);
+	} else {
+		printf("net %3d%% (%4d kb, %5d/%5d)  /  idx %3d%% (%5d/%5d)  /  chk %3d%% (%4" PRIuZ "/%4" PRIuZ ") %s\n",
+		   network_percent, kbytes,
+		   pd->fetch_progress.received_objects, pd->fetch_progress.total_objects,
+		   index_percent, pd->fetch_progress.indexed_objects, pd->fetch_progress.total_objects,
+		   checkout_percent,
+		   pd->completed_steps, pd->total_steps,
+		   pd->path);
+	}
+}
+
+static int sideband_progress(const char *str, int len, void *payload)
+{
+	(void)payload; // unused
+
+	printf("remote: %.*s", len, str);
+	fflush(stdout);
+	return 0;
+}
+
+static int fetch_progress(const git_transfer_progress *stats, void *payload)
+{
+	progress_data *pd = (progress_data*)payload;
+	pd->fetch_progress = *stats;
+	print_progress(pd);
+	return 0;
+}
+static void checkout_progress(const char *path, size_t cur, size_t tot, void *payload)
+{
+	progress_data *pd = (progress_data*)payload;
+	pd->completed_steps = cur;
+	pd->total_steps = tot;
+	pd->path = path;
+	print_progress(pd);
+}
+
+
+int do_clone(git_repository *repo, int argc, char **argv)
+{
+	progress_data pd = {{0}};
+	git_repository *cloned_repo = NULL;
+	git_clone_options clone_opts = GIT_CLONE_OPTIONS_INIT;
+	git_checkout_options checkout_opts = GIT_CHECKOUT_OPTIONS_INIT;
+	const char *url = argv[1];
+	const char *path = argv[2];
+	int error;
+
+	(void)repo; // unused
+
+	// Validate args
+	if (argc < 3) {
+		printf ("USAGE: %s <url> <path>\n", argv[0]);
+		return -1;
+	}
+
+	// Set up options
+	checkout_opts.checkout_strategy = GIT_CHECKOUT_SAFE;
+	checkout_opts.progress_cb = checkout_progress;
+	checkout_opts.progress_payload = &pd;
+	clone_opts.checkout_opts = checkout_opts;
+	clone_opts.fetch_opts.callbacks.sideband_progress = sideband_progress;
+	clone_opts.fetch_opts.callbacks.transfer_progress = &fetch_progress;
+	clone_opts.fetch_opts.callbacks.credentials = cred_acquire_cb;
+	clone_opts.fetch_opts.callbacks.payload = &pd;
+
+	// Do the clone
+	error = git_clone(&cloned_repo, url, path, &clone_opts);
+	printf("\n");
+	if (error != 0) {
+		const git_error *err = giterr_last();
+		if (err) printf("ERROR %d: %s\n", err->klass, err->message);
+		else printf("ERROR %d: no detailed info\n", error);
+	}
+	else if (cloned_repo) git_repository_free(cloned_repo);
+	return error;
+}

vendor/libgit2-sys/libgit2/examples/network/common.c

diff --git a/vendor/libgit2-sys/libgit2/examples/network/common.c b/vendor/libgit2-sys/libgit2/examples/network/common.c
new file mode 100644
index 0000000..b0afb02
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/network/common.c
@@ -0,0 +1,85 @@
+#include "common.h"
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+
+/* Shamelessly borrowed from http://stackoverflow.com/questions/3417837/
+ * with permission of the original author, Martin Pool.
+ * http://sourcefrog.net/weblog/software/languages/C/unused.html
+ */
+#ifdef UNUSED
+#elif defined(__GNUC__)
+# define UNUSED(x) UNUSED_ ## x __attribute__((unused))
+#elif defined(__LCLINT__)
+# define UNUSED(x) /*@unused@*/ x
+#else
+# define UNUSED(x) x
+#endif
+
+static int readline(char **out)
+{
+	int c, error = 0, length = 0, allocated = 0;
+	char *line = NULL;
+
+	errno = 0;
+
+	while ((c = getchar()) != EOF) {
+		if (length == allocated) {
+			allocated += 16;
+
+			if ((line = realloc(line, allocated)) == NULL) {
+				error = -1;
+				goto error;
+			}
+		}
+
+		if (c == '\n')
+			break;
+
+		line[length++] = c;
+	}
+
+	if (errno != 0) {
+		error = -1;
+		goto error;
+	}
+
+	line[length] = '\0';
+	*out = line;
+	line = NULL;
+	error = length;
+error:
+	free(line);
+	return error;
+}
+
+int cred_acquire_cb(git_cred **out,
+		const char * UNUSED(url),
+		const char * UNUSED(username_from_url),
+		unsigned int UNUSED(allowed_types),
+		void * UNUSED(payload))
+{
+	char *username = NULL, *password = NULL;
+	int error;
+
+	printf("Username: ");
+	if (readline(&username) < 0) {
+		fprintf(stderr, "Unable to read username: %s", strerror(errno));
+		return -1;
+	}
+
+	/* Yup. Right there on your terminal. Careful where you copy/paste output. */
+	printf("Password: ");
+	if (readline(&password) < 0) {
+		fprintf(stderr, "Unable to read password: %s", strerror(errno));
+		free(username);
+		return -1;
+	}
+
+	error = git_cred_userpass_plaintext_new(out, username, password);
+
+	free(username);
+	free(password);
+
+	return error;
+}

vendor/libgit2-sys/libgit2/examples/network/common.h

diff --git a/vendor/libgit2-sys/libgit2/examples/network/common.h b/vendor/libgit2-sys/libgit2/examples/network/common.h
new file mode 100644
index 0000000..1b09caa
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/network/common.h
@@ -0,0 +1,30 @@
+#ifndef __COMMON_H__
+#define __COMMON_H__
+
+#include <git2.h>
+
+typedef int (*git_cb)(git_repository *, int , char **);
+
+int ls_remote(git_repository *repo, int argc, char **argv);
+int parse_pkt_line(git_repository *repo, int argc, char **argv);
+int show_remote(git_repository *repo, int argc, char **argv);
+int fetch(git_repository *repo, int argc, char **argv);
+int index_pack(git_repository *repo, int argc, char **argv);
+int do_clone(git_repository *repo, int argc, char **argv);
+
+int cred_acquire_cb(git_cred **out,
+		const char * url,
+		const char * username_from_url,
+		unsigned int allowed_types,
+		void *payload);
+
+#ifndef PRIuZ
+/* Define the printf format specifer to use for size_t output */
+#if defined(_MSC_VER) || defined(__MINGW32__)
+#	define PRIuZ "Iu"
+#else
+#	define PRIuZ "zu"
+#endif
+#endif
+
+#endif /* __COMMON_H__ */

vendor/libgit2-sys/libgit2/examples/network/fetch.c

diff --git a/vendor/libgit2-sys/libgit2/examples/network/fetch.c b/vendor/libgit2-sys/libgit2/examples/network/fetch.c
new file mode 100644
index 0000000..76b3011
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/network/fetch.c
@@ -0,0 +1,117 @@
+#include "common.h"
+#include <git2.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#ifndef _WIN32
+# include <pthread.h>
+# include <unistd.h>
+#endif
+
+static int progress_cb(const char *str, int len, void *data)
+{
+	(void)data;
+	printf("remote: %.*s", len, str);
+	fflush(stdout); /* We don't have the \n to force the flush */
+	return 0;
+}
+
+/**
+ * This function gets called for each remote-tracking branch that gets
+ * updated. The message we output depends on whether it's a new one or
+ * an update.
+ */
+static int update_cb(const char *refname, const git_oid *a, const git_oid *b, void *data)
+{
+	char a_str[GIT_OID_HEXSZ+1], b_str[GIT_OID_HEXSZ+1];
+	(void)data;
+
+	git_oid_fmt(b_str, b);
+	b_str[GIT_OID_HEXSZ] = '\0';
+
+	if (git_oid_iszero(a)) {
+		printf("[new]     %.20s %s\n", b_str, refname);
+	} else {
+		git_oid_fmt(a_str, a);
+		a_str[GIT_OID_HEXSZ] = '\0';
+		printf("[updated] %.10s..%.10s %s\n", a_str, b_str, refname);
+	}
+
+	return 0;
+}
+
+/**
+ * This gets called during the download and indexing. Here we show
+ * processed and total objects in the pack and the amount of received
+ * data. Most frontends will probably want to show a percentage and
+ * the download rate.
+ */
+static int transfer_progress_cb(const git_transfer_progress *stats, void *payload)
+{
+	(void)payload;
+
+	if (stats->received_objects == stats->total_objects) {
+		printf("Resolving deltas %d/%d\r",
+		       stats->indexed_deltas, stats->total_deltas);
+	} else if (stats->total_objects > 0) {
+		printf("Received %d/%d objects (%d) in %" PRIuZ " bytes\r",
+		       stats->received_objects, stats->total_objects,
+		       stats->indexed_objects, stats->received_bytes);
+	}
+	return 0;
+}
+
+/** Entry point for this command */
+int fetch(git_repository *repo, int argc, char **argv)
+{
+	git_remote *remote = NULL;
+	const git_transfer_progress *stats;
+	git_fetch_options fetch_opts = GIT_FETCH_OPTIONS_INIT;
+
+	if (argc < 2) {
+		fprintf(stderr, "usage: %s fetch <repo>\n", argv[-1]);
+		return EXIT_FAILURE;
+	}
+
+	/* Figure out whether it's a named remote or a URL */
+	printf("Fetching %s for repo %p\n", argv[1], repo);
+	if (git_remote_lookup(&remote, repo, argv[1]) < 0)
+		if (git_remote_create_anonymous(&remote, repo, argv[1]) < 0)
+			goto on_error;
+
+	/* Set up the callbacks (only update_tips for now) */
+	fetch_opts.callbacks.update_tips = &update_cb;
+	fetch_opts.callbacks.sideband_progress = &progress_cb;
+	fetch_opts.callbacks.transfer_progress = transfer_progress_cb;
+	fetch_opts.callbacks.credentials = cred_acquire_cb;
+
+	/**
+	 * Perform the fetch with the configured refspecs from the
+	 * config. Update the reflog for the updated references with
+	 * "fetch".
+	 */
+	if (git_remote_fetch(remote, NULL, &fetch_opts, "fetch") < 0)
+		goto on_error;
+
+	/**
+	 * If there are local objects (we got a thin pack), then tell
+	 * the user how many objects we saved from having to cross the
+	 * network.
+	 */
+	stats = git_remote_stats(remote);
+	if (stats->local_objects > 0) {
+		printf("\rReceived %d/%d objects in %" PRIuZ " bytes (used %d local objects)\n",
+		       stats->indexed_objects, stats->total_objects, stats->received_bytes, stats->local_objects);
+	} else{
+		printf("\rReceived %d/%d objects in %" PRIuZ "bytes\n",
+			stats->indexed_objects, stats->total_objects, stats->received_bytes);
+	}
+
+	git_remote_free(remote);
+
+	return 0;
+
+ on_error:
+	git_remote_free(remote);
+	return -1;
+}

vendor/libgit2-sys/libgit2/examples/network/git2.c

diff --git a/vendor/libgit2-sys/libgit2/examples/network/git2.c b/vendor/libgit2-sys/libgit2/examples/network/git2.c
new file mode 100644
index 0000000..1d3d27b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/network/git2.c
@@ -0,0 +1,90 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "../common.h"
+#include "common.h"
+
+/* This part is not strictly libgit2-dependent, but you can use this
+ * as a starting point for a git-like tool */
+
+struct {
+	char *name;
+	git_cb fn;
+} commands[] = {
+	{"ls-remote", ls_remote},
+	{"fetch", fetch},
+	{"clone", do_clone},
+	{"index-pack", index_pack},
+	{ NULL, NULL}
+};
+
+static int run_command(git_cb fn, git_repository *repo, struct args_info args)
+{
+	int error;
+
+	/* Run the command. If something goes wrong, print the error message to stderr */
+	error = fn(repo, args.argc - args.pos, &args.argv[args.pos]);
+	if (error < 0) {
+		if (giterr_last() == NULL)
+			fprintf(stderr, "Error without message");
+		else
+			fprintf(stderr, "Bad news:\n %s\n", giterr_last()->message);
+	}
+
+	return !!error;
+}
+
+int main(int argc, char **argv)
+{
+	int i;
+	int return_code = 1;
+	int error;
+	git_repository *repo;
+	struct args_info args = ARGS_INFO_INIT;
+	const char *git_dir = NULL;
+
+	if (argc < 2) {
+		fprintf(stderr, "usage: %s <cmd> [repo]\n", argv[0]);
+		exit(EXIT_FAILURE);
+	}
+
+	git_libgit2_init();
+
+	for (args.pos = 1; args.pos < args.argc; ++args.pos) {
+		char *a = args.argv[args.pos];
+
+		if (a[0] != '-') {
+			/* non-arg */
+			break;
+		} else if (optional_str_arg(&git_dir, &args, "--git-dir", ".git")) {
+			continue;
+		} else if (!strcmp(a, "--")) {
+			/* arg separator */
+			break;
+		}
+	}
+
+	/* Before running the actual command, create an instance of the local
+	 * repository and pass it to the function. */
+
+	error = git_repository_open(&repo, git_dir);
+	if (error < 0)
+		repo = NULL;
+
+	for (i = 0; commands[i].name != NULL; ++i) {
+		if (!strcmp(args.argv[args.pos], commands[i].name)) {
+			return_code = run_command(commands[i].fn, repo, args);
+			goto shutdown;
+		}
+	}
+
+	fprintf(stderr, "Command not found: %s\n", argv[1]);
+
+shutdown:
+	git_repository_free(repo);
+
+	git_libgit2_shutdown();
+
+	return return_code;
+}

vendor/libgit2-sys/libgit2/examples/network/index-pack.c

diff --git a/vendor/libgit2-sys/libgit2/examples/network/index-pack.c b/vendor/libgit2-sys/libgit2/examples/network/index-pack.c
new file mode 100644
index 0000000..314f211
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/network/index-pack.c
@@ -0,0 +1,88 @@
+#include <git2.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#ifdef _WIN32
+# include <io.h>
+# include <Windows.h>
+
+# define open _open
+# define read _read
+# define close _close
+
+#define ssize_t unsigned int
+#else
+# include <unistd.h>
+#endif
+#include "common.h"
+
+// This could be run in the main loop whilst the application waits for
+// the indexing to finish in a worker thread
+static int index_cb(const git_transfer_progress *stats, void *data)
+{
+	(void)data;
+	printf("\rProcessing %d of %d", stats->indexed_objects, stats->total_objects);
+
+	return 0;
+}
+
+int index_pack(git_repository *repo, int argc, char **argv)
+{
+	git_indexer *idx;
+	git_transfer_progress stats = {0, 0};
+	int error;
+	char hash[GIT_OID_HEXSZ + 1] = {0};
+	int fd;
+	ssize_t read_bytes;
+	char buf[512];
+
+	(void)repo;
+
+	if (argc < 2) {
+		fprintf(stderr, "usage: %s index-pack <packfile>\n", argv[-1]);
+		return EXIT_FAILURE;
+	}
+
+	if (git_indexer_new(&idx, ".", 0, NULL, NULL, NULL) < 0) {
+		puts("bad idx");
+		return -1;
+	}
+
+	if ((fd = open(argv[1], 0)) < 0) {
+		perror("open");
+		return -1;
+	}
+
+	do {
+		read_bytes = read(fd, buf, sizeof(buf));
+		if (read_bytes < 0)
+			break;
+
+		if ((error = git_indexer_append(idx, buf, read_bytes, &stats)) < 0)
+			goto cleanup;
+
+		index_cb(&stats, NULL);
+	} while (read_bytes > 0);
+
+	if (read_bytes < 0) {
+		error = -1;
+		perror("failed reading");
+		goto cleanup;
+	}
+
+	if ((error = git_indexer_commit(idx, &stats)) < 0)
+		goto cleanup;
+
+	printf("\rIndexing %d of %d\n", stats.indexed_objects, stats.total_objects);
+
+	git_oid_fmt(hash, git_indexer_hash(idx));
+	puts(hash);
+
+ cleanup:
+	close(fd);
+	git_indexer_free(idx);
+	return error;
+}

vendor/libgit2-sys/libgit2/examples/network/ls-remote.c

diff --git a/vendor/libgit2-sys/libgit2/examples/network/ls-remote.c b/vendor/libgit2-sys/libgit2/examples/network/ls-remote.c
new file mode 100644
index 0000000..9329da5
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/network/ls-remote.c
@@ -0,0 +1,64 @@
+#include <git2.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "common.h"
+
+static int use_remote(git_repository *repo, char *name)
+{
+	git_remote *remote = NULL;
+	int error;
+	const git_remote_head **refs;
+	size_t refs_len, i;
+	git_remote_callbacks callbacks = GIT_REMOTE_CALLBACKS_INIT;
+
+	// Find the remote by name
+	error = git_remote_lookup(&remote, repo, name);
+	if (error < 0) {
+		error = git_remote_create_anonymous(&remote, repo, name);
+		if (error < 0)
+			goto cleanup;
+	}
+
+	/**
+	 * Connect to the remote and call the printing function for
+	 * each of the remote references.
+	 */
+	callbacks.credentials = cred_acquire_cb;
+
+	error = git_remote_connect(remote, GIT_DIRECTION_FETCH, &callbacks, NULL, NULL);
+	if (error < 0)
+		goto cleanup;
+
+	/**
+	 * Get the list of references on the remote and print out
+	 * their name next to what they point to.
+	 */
+	if (git_remote_ls(&refs, &refs_len, remote) < 0)
+		goto cleanup;
+
+	for (i = 0; i < refs_len; i++) {
+		char oid[GIT_OID_HEXSZ + 1] = {0};
+		git_oid_fmt(oid, &refs[i]->oid);
+		printf("%s\t%s\n", oid, refs[i]->name);
+	}
+
+cleanup:
+	git_remote_free(remote);
+	return error;
+}
+
+/** Entry point for this command */
+int ls_remote(git_repository *repo, int argc, char **argv)
+{
+	int error;
+
+	if (argc < 2) {
+		fprintf(stderr, "usage: %s ls-remote <remote>\n", argv[-1]);
+		return EXIT_FAILURE;
+	}
+
+	error = use_remote(repo, argv[1]);
+
+	return error;
+}

vendor/libgit2-sys/libgit2/examples/remote.c

diff --git a/vendor/libgit2-sys/libgit2/examples/remote.c b/vendor/libgit2-sys/libgit2/examples/remote.c
new file mode 100644
index 0000000..e0d5a14
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/remote.c
@@ -0,0 +1,269 @@
+/*
+ * libgit2 "remote" example - shows how to modify remotes for a repo
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include "common.h"
+
+/**
+ * This is a sample program that is similar to "git remote".  See the
+ * documentation for that (try "git help remote") to understand what this
+ * program is emulating.
+ *
+ * This demonstrates using the libgit2 APIs to modify remotes of a repository.
+ */
+
+enum subcmd {
+	subcmd_add,
+	subcmd_remove,
+	subcmd_rename,
+	subcmd_seturl,
+	subcmd_show,
+};
+
+struct opts {
+	enum subcmd cmd;
+
+	/* for command-specific args */
+	int argc;
+	char **argv;
+};
+
+static int cmd_add(git_repository *repo, struct opts *o);
+static int cmd_remove(git_repository *repo, struct opts *o);
+static int cmd_rename(git_repository *repo, struct opts *o);
+static int cmd_seturl(git_repository *repo, struct opts *o);
+static int cmd_show(git_repository *repo, struct opts *o);
+
+static void parse_subcmd(
+	struct opts *opt, int argc, char **argv);
+static void usage(const char *msg, const char *arg);
+
+int main(int argc, char *argv[])
+{
+	int retval = 0;
+	struct opts opt = {0};
+	git_buf buf = GIT_BUF_INIT_CONST(NULL, 0);
+	git_repository *repo = NULL;
+
+	parse_subcmd(&opt, argc, argv);
+
+	git_libgit2_init();
+
+	check_lg2(git_repository_discover(&buf, ".", 0, NULL),
+		"Could not find repository", NULL);
+
+	check_lg2(git_repository_open(&repo, buf.ptr),
+		"Could not open repository", NULL);
+	git_buf_free(&buf);
+
+	switch (opt.cmd)
+	{
+	case subcmd_add:
+		retval = cmd_add(repo, &opt);
+		break;
+	case subcmd_remove:
+		retval = cmd_remove(repo, &opt);
+		break;
+	case subcmd_rename:
+		retval = cmd_rename(repo, &opt);
+		break;
+	case subcmd_seturl:
+		retval = cmd_seturl(repo, &opt);
+		break;
+	case subcmd_show:
+		retval = cmd_show(repo, &opt);
+		break;
+	}
+
+	git_libgit2_shutdown();
+
+	return retval;
+}
+
+static int cmd_add(git_repository *repo, struct opts *o)
+{
+	char *name, *url;
+	git_remote *remote = {0};
+
+	if (o->argc != 2)
+		usage("you need to specify a name and URL", NULL);
+
+	name = o->argv[0];
+	url = o->argv[1];
+
+	check_lg2(git_remote_create(&remote, repo, name, url),
+			"could not create remote", NULL);
+
+	return 0;
+}
+
+static int cmd_remove(git_repository *repo, struct opts *o)
+{
+	char *name;
+
+	if (o->argc != 1)
+		usage("you need to specify a name", NULL);
+
+	name = o->argv[0];
+
+	check_lg2(git_remote_delete(repo, name),
+			"could not delete remote", name);
+
+	return 0;
+}
+
+static int cmd_rename(git_repository *repo, struct opts *o)
+{
+	int i, retval;
+	char *old, *new;
+	git_strarray problems = {0};
+
+	if (o->argc != 2)
+		usage("you need to specify old and new remote name", NULL);
+
+	old = o->argv[0];
+	new = o->argv[1];
+
+	retval = git_remote_rename(&problems, repo, old, new);
+	if (!retval)
+		return 0;
+
+	for (i = 0; i < (int) problems.count; i++) {
+		puts(problems.strings[0]);
+	}
+
+	git_strarray_free(&problems);
+
+	return retval;
+}
+
+static int cmd_seturl(git_repository *repo, struct opts *o)
+{
+	int i, retval, push = 0;
+	char *name = NULL, *url = NULL;
+
+	for (i = 0; i < o->argc; i++) {
+		char *arg = o->argv[i];
+
+		if (!strcmp(arg, "--push")) {
+			push = 1;
+		} else if (arg[0] != '-' && name == NULL) {
+			name = arg;
+		} else if (arg[0] != '-' && url == NULL) {
+			url = arg;
+		} else {
+			usage("invalid argument to set-url", arg);
+		}
+	}
+
+	if (name == NULL || url == NULL)
+		usage("you need to specify remote and the new URL", NULL);
+
+	if (push)
+		retval = git_remote_set_pushurl(repo, name, url);
+	else
+		retval = git_remote_set_url(repo, name, url);
+
+	check_lg2(retval, "could not set URL", url);
+
+	return 0;
+}
+
+static int cmd_show(git_repository *repo, struct opts *o)
+{
+	int i;
+	const char *arg, *name, *fetch, *push;
+	int verbose = 0;
+	git_strarray remotes = {0};
+	git_remote *remote = {0};
+
+	for (i = 0; i < o->argc; i++) {
+		arg = o->argv[i];
+
+		if (!strcmp(arg, "-v") || !strcmp(arg, "--verbose")) {
+			verbose = 1;
+		}
+	}
+
+	check_lg2(git_remote_list(&remotes, repo),
+		"could not retrieve remotes", NULL);
+
+	for (i = 0; i < (int) remotes.count; i++) {
+		name = remotes.strings[i];
+		if (!verbose) {
+			puts(name);
+			continue;
+		}
+
+		check_lg2(git_remote_lookup(&remote, repo, name),
+			"could not look up remote", name);
+
+		fetch = git_remote_url(remote);
+		if (fetch)
+			printf("%s\t%s (fetch)\n", name, fetch);
+		push = git_remote_pushurl(remote);
+		/* use fetch URL if no distinct push URL has been set */
+		push = push ? push : fetch;
+		if (push)
+			printf("%s\t%s (push)\n", name, push);
+
+		git_remote_free(remote);
+	}
+
+	git_strarray_free(&remotes);
+
+	return 0;
+}
+
+static void parse_subcmd(
+	struct opts *opt, int argc, char **argv)
+{
+	char *arg = argv[1];
+	enum subcmd cmd = 0;
+
+	if (argc < 2)
+		usage("no command specified", NULL);
+
+	if (!strcmp(arg, "add")) {
+		cmd = subcmd_add;
+	} else if (!strcmp(arg, "remove")) {
+		cmd = subcmd_remove;
+	} else if (!strcmp(arg, "rename")) {
+		cmd = subcmd_rename;
+	} else if (!strcmp(arg, "set-url")) {
+		cmd = subcmd_seturl;
+	} else if (!strcmp(arg, "show")) {
+		cmd = subcmd_show;
+	} else {
+		usage("command is not valid", arg);
+	}
+	opt->cmd = cmd;
+
+	opt->argc = argc - 2; /* executable and subcommand are removed */
+	opt->argv = argv + 2;
+}
+
+static void usage(const char *msg, const char *arg)
+{
+	fputs("usage: remote add <name> <url>\n", stderr);
+	fputs("       remote remove <name>\n", stderr);
+	fputs("       remote rename <old> <new>\n", stderr);
+	fputs("       remote set-url [--push] <name> <newurl>\n", stderr);
+	fputs("       remote show [-v|--verbose]\n", stderr);
+
+	if (msg && !arg)
+		fprintf(stderr, "\n%s\n", msg);
+	else if (msg && arg)
+		fprintf(stderr, "\n%s: %s\n", msg, arg);
+	exit(1);
+}

vendor/libgit2-sys/libgit2/examples/rev-list.c

diff --git a/vendor/libgit2-sys/libgit2/examples/rev-list.c b/vendor/libgit2-sys/libgit2/examples/rev-list.c
new file mode 100644
index 0000000..ee9afc4
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/rev-list.c
@@ -0,0 +1,121 @@
+/*
+ * libgit2 "rev-list" example - shows how to transform a rev-spec into a list
+ * of commit ids
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include "common.h"
+
+static int revwalk_parseopts(git_repository *repo, git_revwalk *walk, int nopts, char **opts);
+
+int main (int argc, char **argv)
+{
+	git_repository *repo;
+	git_revwalk *walk;
+	git_oid oid;
+	char buf[GIT_OID_HEXSZ+1];
+
+	git_libgit2_init();
+
+	check_lg2(git_repository_open_ext(&repo, ".", 0, NULL), "opening repository", NULL);
+	check_lg2(git_revwalk_new(&walk, repo), "allocating revwalk", NULL);
+	check_lg2(revwalk_parseopts(repo, walk, argc-1, argv+1), "parsing options", NULL);
+
+	while (!git_revwalk_next(&oid, walk)) {
+		git_oid_fmt(buf, &oid);
+		buf[GIT_OID_HEXSZ] = '\0';
+		printf("%s\n", buf);
+	}
+
+	git_libgit2_shutdown();
+	return 0;
+}
+
+static int push_commit(git_revwalk *walk, const git_oid *oid, int hide)
+{
+	if (hide)
+		return git_revwalk_hide(walk, oid);
+	else
+		return git_revwalk_push(walk, oid);
+}
+
+static int push_spec(git_repository *repo, git_revwalk *walk, const char *spec, int hide)
+{
+	int error;
+	git_object *obj;
+
+	if ((error = git_revparse_single(&obj, repo, spec)) < 0)
+		return error;
+
+	error = push_commit(walk, git_object_id(obj), hide);
+	git_object_free(obj);
+	return error;
+}
+
+static int push_range(git_repository *repo, git_revwalk *walk, const char *range, int hide)
+{
+	git_revspec revspec;
+	int error = 0;
+
+	if ((error = git_revparse(&revspec, repo, range)))
+		return error;
+
+	if (revspec.flags & GIT_REVPARSE_MERGE_BASE) {
+		/* TODO: support "<commit>...<commit>" */
+		return GIT_EINVALIDSPEC;
+	}
+
+	if ((error = push_commit(walk, git_object_id(revspec.from), !hide)))
+		goto out;
+
+	error = push_commit(walk, git_object_id(revspec.to), hide);
+
+out:
+	git_object_free(revspec.from);
+	git_object_free(revspec.to);
+	return error;
+}
+
+static int revwalk_parseopts(git_repository *repo, git_revwalk *walk, int nopts, char **opts)
+{
+	int hide, i, error;
+	unsigned int sorting = GIT_SORT_NONE;
+
+	hide = 0;
+	for (i = 0; i < nopts; i++) {
+		if (!strcmp(opts[i], "--topo-order")) {
+			sorting = GIT_SORT_TOPOLOGICAL | (sorting & GIT_SORT_REVERSE);
+			git_revwalk_sorting(walk, sorting);
+		} else if (!strcmp(opts[i], "--date-order")) {
+			sorting = GIT_SORT_TIME | (sorting & GIT_SORT_REVERSE);
+			git_revwalk_sorting(walk, sorting);
+		} else if (!strcmp(opts[i], "--reverse")) {
+			sorting = (sorting & ~GIT_SORT_REVERSE)
+			    | ((sorting & GIT_SORT_REVERSE) ? 0 : GIT_SORT_REVERSE);
+			git_revwalk_sorting(walk, sorting);
+		} else if (!strcmp(opts[i], "--not")) {
+			hide = !hide;
+		} else if (opts[i][0] == '^') {
+			if ((error = push_spec(repo, walk, opts[i] + 1, !hide)))
+				return error;
+		} else if (strstr(opts[i], "..")) {
+			if ((error = push_range(repo, walk, opts[i], hide)))
+				return error;
+		} else {
+			if ((error = push_spec(repo, walk, opts[i], hide)))
+				return error;
+		}
+	}
+
+	return 0;
+}
+

vendor/libgit2-sys/libgit2/examples/rev-parse.c

diff --git a/vendor/libgit2-sys/libgit2/examples/rev-parse.c b/vendor/libgit2-sys/libgit2/examples/rev-parse.c
new file mode 100644
index 0000000..483d6e0
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/rev-parse.c
@@ -0,0 +1,115 @@
+/*
+ * libgit2 "rev-parse" example - shows how to parse revspecs
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include "common.h"
+
+/** Forward declarations for helpers. */
+struct parse_state {
+	git_repository *repo;
+	const char *repodir;
+	const char *spec;
+	int not;
+};
+static void parse_opts(struct parse_state *ps, int argc, char *argv[]);
+static int parse_revision(struct parse_state *ps);
+
+
+int main(int argc, char *argv[])
+{
+	struct parse_state ps = {0};
+
+	git_libgit2_init();
+	parse_opts(&ps, argc, argv);
+
+	check_lg2(parse_revision(&ps), "Parsing", NULL);
+
+	git_repository_free(ps.repo);
+	git_libgit2_shutdown();
+
+	return 0;
+}
+
+static void usage(const char *message, const char *arg)
+{
+	if (message && arg)
+		fprintf(stderr, "%s: %s\n", message, arg);
+	else if (message)
+		fprintf(stderr, "%s\n", message);
+	fprintf(stderr, "usage: rev-parse [ --option ] <args>...\n");
+	exit(1);
+}
+
+static void parse_opts(struct parse_state *ps, int argc, char *argv[])
+{
+	struct args_info args = ARGS_INFO_INIT;
+
+	for (args.pos=1; args.pos < argc; ++args.pos) {
+		const char *a = argv[args.pos];
+
+		if (a[0] != '-') {
+			if (ps->spec)
+				usage("Too many specs", a);
+			ps->spec = a;
+		} else if (!strcmp(a, "--not"))
+			ps->not = !ps->not;
+		else if (!match_str_arg(&ps->repodir, &args, "--git-dir"))
+			usage("Cannot handle argument", a);
+	}
+}
+
+static int parse_revision(struct parse_state *ps)
+{
+	git_revspec rs;
+	char str[GIT_OID_HEXSZ + 1];
+
+	if (!ps->repo) {
+		if (!ps->repodir)
+			ps->repodir = ".";
+		check_lg2(git_repository_open_ext(&ps->repo, ps->repodir, 0, NULL),
+			"Could not open repository from", ps->repodir);
+	}
+
+	check_lg2(git_revparse(&rs, ps->repo, ps->spec), "Could not parse", ps->spec);
+
+	if ((rs.flags & GIT_REVPARSE_SINGLE) != 0) {
+		git_oid_tostr(str, sizeof(str), git_object_id(rs.from));
+		printf("%s\n", str);
+		git_object_free(rs.from);
+	}
+	else if ((rs.flags & GIT_REVPARSE_RANGE) != 0) {
+		git_oid_tostr(str, sizeof(str), git_object_id(rs.to));
+		printf("%s\n", str);
+		git_object_free(rs.to);
+
+		if ((rs.flags & GIT_REVPARSE_MERGE_BASE) != 0) {
+			git_oid base;
+			check_lg2(git_merge_base(&base, ps->repo,
+						git_object_id(rs.from), git_object_id(rs.to)),
+					"Could not find merge base", ps->spec);
+
+			git_oid_tostr(str, sizeof(str), &base);
+			printf("%s\n", str);
+		}
+
+		git_oid_tostr(str, sizeof(str), git_object_id(rs.from));
+		printf("^%s\n", str);
+		git_object_free(rs.from);
+	}
+	else {
+		fatal("Invalid results from git_revparse", ps->spec);
+	}
+
+	return 0;
+}
+

vendor/libgit2-sys/libgit2/examples/showindex.c

diff --git a/vendor/libgit2-sys/libgit2/examples/showindex.c b/vendor/libgit2-sys/libgit2/examples/showindex.c
new file mode 100644
index 0000000..43be5e2
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/showindex.c
@@ -0,0 +1,70 @@
+/*
+ * libgit2 "showindex" example - shows how to extract data from the index
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include "common.h"
+
+int main (int argc, char** argv)
+{
+	git_index *index;
+	unsigned int i, ecount;
+	char *dir = ".";
+	size_t dirlen;
+	char out[GIT_OID_HEXSZ+1];
+	out[GIT_OID_HEXSZ] = '\0';
+
+	git_libgit2_init();
+
+	if (argc > 2)
+		fatal("usage: showindex [<repo-dir>]", NULL);
+	if (argc > 1)
+		dir = argv[1];
+
+	dirlen = strlen(dir);
+	if (dirlen > 5 && strcmp(dir + dirlen - 5, "index") == 0) {
+		check_lg2(git_index_open(&index, dir), "could not open index", dir);
+	} else {
+		git_repository *repo;
+		check_lg2(git_repository_open_ext(&repo, dir, 0, NULL), "could not open repository", dir);
+		check_lg2(git_repository_index(&index, repo), "could not open repository index", NULL);
+		git_repository_free(repo);
+	}
+
+	git_index_read(index, 0);
+
+	ecount = git_index_entrycount(index);
+	if (!ecount)
+		printf("Empty index\n");
+
+	for (i = 0; i < ecount; ++i) {
+		const git_index_entry *e = git_index_get_byindex(index, i);
+
+		git_oid_fmt(out, &e->id);
+
+		printf("File Path: %s\n", e->path);
+		printf("    Stage: %d\n", git_index_entry_stage(e));
+		printf(" Blob SHA: %s\n", out);
+		printf("File Mode: %07o\n", e->mode);
+		printf("File Size: %d bytes\n", (int)e->file_size);
+		printf("Dev/Inode: %d/%d\n", (int)e->dev, (int)e->ino);
+		printf("  UID/GID: %d/%d\n", (int)e->uid, (int)e->gid);
+		printf("    ctime: %d\n", (int)e->ctime.seconds);
+		printf("    mtime: %d\n", (int)e->mtime.seconds);
+		printf("\n");
+	}
+
+	git_index_free(index);
+	git_libgit2_shutdown();
+
+	return 0;
+}

vendor/libgit2-sys/libgit2/examples/status.c

diff --git a/vendor/libgit2-sys/libgit2/examples/status.c b/vendor/libgit2-sys/libgit2/examples/status.c
new file mode 100644
index 0000000..49f006d
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/status.c
@@ -0,0 +1,517 @@
+/*
+ * libgit2 "status" example - shows how to use the status APIs
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include "common.h"
+#ifdef _WIN32
+# include <Windows.h>
+# define sleep(a) Sleep(a * 1000)
+#else
+# include <unistd.h>
+#endif
+
+/**
+ * This example demonstrates the use of the libgit2 status APIs,
+ * particularly the `git_status_list` object, to roughly simulate the
+ * output of running `git status`.  It serves as a simple example of
+ * using those APIs to get basic status information.
+ *
+ * This does not have:
+ *
+ * - Robust error handling
+ * - Colorized or paginated output formatting
+ *
+ * This does have:
+ *
+ * - Examples of translating command line arguments to the status
+ *   options settings to mimic `git status` results.
+ * - A sample status formatter that matches the default "long" format
+ *   from `git status`
+ * - A sample status formatter that matches the "short" format
+ */
+
+enum {
+	FORMAT_DEFAULT   = 0,
+	FORMAT_LONG      = 1,
+	FORMAT_SHORT     = 2,
+	FORMAT_PORCELAIN = 3,
+};
+
+#define MAX_PATHSPEC 8
+
+struct opts {
+	git_status_options statusopt;
+	char *repodir;
+	char *pathspec[MAX_PATHSPEC];
+	int npaths;
+	int format;
+	int zterm;
+	int showbranch;
+	int showsubmod;
+	int repeat;
+};
+
+static void parse_opts(struct opts *o, int argc, char *argv[]);
+static void show_branch(git_repository *repo, int format);
+static void print_long(git_status_list *status);
+static void print_short(git_repository *repo, git_status_list *status);
+static int print_submod(git_submodule *sm, const char *name, void *payload);
+
+int main(int argc, char *argv[])
+{
+	git_repository *repo = NULL;
+	git_status_list *status;
+	struct opts o = { GIT_STATUS_OPTIONS_INIT, "." };
+
+	git_libgit2_init();
+
+	o.statusopt.show  = GIT_STATUS_SHOW_INDEX_AND_WORKDIR;
+	o.statusopt.flags = GIT_STATUS_OPT_INCLUDE_UNTRACKED |
+		GIT_STATUS_OPT_RENAMES_HEAD_TO_INDEX |
+		GIT_STATUS_OPT_SORT_CASE_SENSITIVELY;
+
+	parse_opts(&o, argc, argv);
+
+	/**
+	 * Try to open the repository at the given path (or at the current
+	 * directory if none was given).
+	 */
+	check_lg2(git_repository_open_ext(&repo, o.repodir, 0, NULL),
+		  "Could not open repository", o.repodir);
+
+	if (git_repository_is_bare(repo))
+		fatal("Cannot report status on bare repository",
+			git_repository_path(repo));
+
+show_status:
+	if (o.repeat)
+		printf("\033[H\033[2J");
+
+	/**
+	 * Run status on the repository
+	 *
+	 * We use `git_status_list_new()` to generate a list of status
+	 * information which lets us iterate over it at our
+	 * convenience and extract the data we want to show out of
+	 * each entry.
+	 *
+	 * You can use `git_status_foreach()` or
+	 * `git_status_foreach_ext()` if you'd prefer to execute a
+	 * callback for each entry. The latter gives you more control
+	 * about what results are presented.
+	 */
+	check_lg2(git_status_list_new(&status, repo, &o.statusopt),
+		"Could not get status", NULL);
+
+	if (o.showbranch)
+		show_branch(repo, o.format);
+
+	if (o.showsubmod) {
+		int submod_count = 0;
+		check_lg2(git_submodule_foreach(repo, print_submod, &submod_count),
+			"Cannot iterate submodules", o.repodir);
+	}
+
+	if (o.format == FORMAT_LONG)
+		print_long(status);
+	else
+		print_short(repo, status);
+
+	git_status_list_free(status);
+
+	if (o.repeat) {
+		sleep(o.repeat);
+		goto show_status;
+	}
+
+	git_repository_free(repo);
+	git_libgit2_shutdown();
+
+	return 0;
+}
+
+/**
+ * If the user asked for the branch, let's show the short name of the
+ * branch.
+ */
+static void show_branch(git_repository *repo, int format)
+{
+	int error = 0;
+	const char *branch = NULL;
+	git_reference *head = NULL;
+
+	error = git_repository_head(&head, repo);
+
+	if (error == GIT_EUNBORNBRANCH || error == GIT_ENOTFOUND)
+		branch = NULL;
+	else if (!error) {
+		branch = git_reference_shorthand(head);
+	} else
+		check_lg2(error, "failed to get current branch", NULL);
+
+	if (format == FORMAT_LONG)
+		printf("# On branch %s\n",
+			branch ? branch : "Not currently on any branch.");
+	else
+		printf("## %s\n", branch ? branch : "HEAD (no branch)");
+
+	git_reference_free(head);
+}
+
+/**
+ * This function print out an output similar to git's status command
+ * in long form, including the command-line hints.
+ */
+static void print_long(git_status_list *status)
+{
+	size_t i, maxi = git_status_list_entrycount(status);
+	const git_status_entry *s;
+	int header = 0, changes_in_index = 0;
+	int changed_in_workdir = 0, rm_in_workdir = 0;
+	const char *old_path, *new_path;
+
+	/** Print index changes. */
+
+	for (i = 0; i < maxi; ++i) {
+		char *istatus = NULL;
+
+		s = git_status_byindex(status, i);
+
+		if (s->status == GIT_STATUS_CURRENT)
+			continue;
+
+		if (s->status & GIT_STATUS_WT_DELETED)
+			rm_in_workdir = 1;
+
+		if (s->status & GIT_STATUS_INDEX_NEW)
+			istatus = "new file: ";
+		if (s->status & GIT_STATUS_INDEX_MODIFIED)
+			istatus = "modified: ";
+		if (s->status & GIT_STATUS_INDEX_DELETED)
+			istatus = "deleted:  ";
+		if (s->status & GIT_STATUS_INDEX_RENAMED)
+			istatus = "renamed:  ";
+		if (s->status & GIT_STATUS_INDEX_TYPECHANGE)
+			istatus = "typechange:";
+
+		if (istatus == NULL)
+			continue;
+
+		if (!header) {
+			printf("# Changes to be committed:\n");
+			printf("#   (use \"git reset HEAD <file>...\" to unstage)\n");
+			printf("#\n");
+			header = 1;
+		}
+
+		old_path = s->head_to_index->old_file.path;
+		new_path = s->head_to_index->new_file.path;
+
+		if (old_path && new_path && strcmp(old_path, new_path))
+			printf("#\t%s  %s -> %s\n", istatus, old_path, new_path);
+		else
+			printf("#\t%s  %s\n", istatus, old_path ? old_path : new_path);
+	}
+
+	if (header) {
+		changes_in_index = 1;
+		printf("#\n");
+	}
+	header = 0;
+
+	/** Print workdir changes to tracked files. */
+
+	for (i = 0; i < maxi; ++i) {
+		char *wstatus = NULL;
+
+		s = git_status_byindex(status, i);
+
+		/**
+		 * With `GIT_STATUS_OPT_INCLUDE_UNMODIFIED` (not used in this example)
+		 * `index_to_workdir` may not be `NULL` even if there are
+		 * no differences, in which case it will be a `GIT_DELTA_UNMODIFIED`.
+		 */
+		if (s->status == GIT_STATUS_CURRENT || s->index_to_workdir == NULL)
+			continue;
+
+		/** Print out the output since we know the file has some changes */
+		if (s->status & GIT_STATUS_WT_MODIFIED)
+			wstatus = "modified: ";
+		if (s->status & GIT_STATUS_WT_DELETED)
+			wstatus = "deleted:  ";
+		if (s->status & GIT_STATUS_WT_RENAMED)
+			wstatus = "renamed:  ";
+		if (s->status & GIT_STATUS_WT_TYPECHANGE)
+			wstatus = "typechange:";
+
+		if (wstatus == NULL)
+			continue;
+
+		if (!header) {
+			printf("# Changes not staged for commit:\n");
+			printf("#   (use \"git add%s <file>...\" to update what will be committed)\n", rm_in_workdir ? "/rm" : "");
+			printf("#   (use \"git checkout -- <file>...\" to discard changes in working directory)\n");
+			printf("#\n");
+			header = 1;
+		}
+
+		old_path = s->index_to_workdir->old_file.path;
+		new_path = s->index_to_workdir->new_file.path;
+
+		if (old_path && new_path && strcmp(old_path, new_path))
+			printf("#\t%s  %s -> %s\n", wstatus, old_path, new_path);
+		else
+			printf("#\t%s  %s\n", wstatus, old_path ? old_path : new_path);
+	}
+
+	if (header) {
+		changed_in_workdir = 1;
+		printf("#\n");
+	}
+
+	/** Print untracked files. */
+
+	header = 0;
+
+	for (i = 0; i < maxi; ++i) {
+		s = git_status_byindex(status, i);
+
+		if (s->status == GIT_STATUS_WT_NEW) {
+
+			if (!header) {
+				printf("# Untracked files:\n");
+				printf("#   (use \"git add <file>...\" to include in what will be committed)\n");
+				printf("#\n");
+				header = 1;
+			}
+
+			printf("#\t%s\n", s->index_to_workdir->old_file.path);
+		}
+	}
+
+	header = 0;
+
+	/** Print ignored files. */
+
+	for (i = 0; i < maxi; ++i) {
+		s = git_status_byindex(status, i);
+
+		if (s->status == GIT_STATUS_IGNORED) {
+
+			if (!header) {
+				printf("# Ignored files:\n");
+				printf("#   (use \"git add -f <file>...\" to include in what will be committed)\n");
+				printf("#\n");
+				header = 1;
+			}
+
+			printf("#\t%s\n", s->index_to_workdir->old_file.path);
+		}
+	}
+
+	if (!changes_in_index && changed_in_workdir)
+		printf("no changes added to commit (use \"git add\" and/or \"git commit -a\")\n");
+}
+
+/**
+ * This version of the output prefixes each path with two status
+ * columns and shows submodule status information.
+ */
+static void print_short(git_repository *repo, git_status_list *status)
+{
+	size_t i, maxi = git_status_list_entrycount(status);
+	const git_status_entry *s;
+	char istatus, wstatus;
+	const char *extra, *a, *b, *c;
+
+	for (i = 0; i < maxi; ++i) {
+		s = git_status_byindex(status, i);
+
+		if (s->status == GIT_STATUS_CURRENT)
+			continue;
+
+		a = b = c = NULL;
+		istatus = wstatus = ' ';
+		extra = "";
+
+		if (s->status & GIT_STATUS_INDEX_NEW)
+			istatus = 'A';
+		if (s->status & GIT_STATUS_INDEX_MODIFIED)
+			istatus = 'M';
+		if (s->status & GIT_STATUS_INDEX_DELETED)
+			istatus = 'D';
+		if (s->status & GIT_STATUS_INDEX_RENAMED)
+			istatus = 'R';
+		if (s->status & GIT_STATUS_INDEX_TYPECHANGE)
+			istatus = 'T';
+
+		if (s->status & GIT_STATUS_WT_NEW) {
+			if (istatus == ' ')
+				istatus = '?';
+			wstatus = '?';
+		}
+		if (s->status & GIT_STATUS_WT_MODIFIED)
+			wstatus = 'M';
+		if (s->status & GIT_STATUS_WT_DELETED)
+			wstatus = 'D';
+		if (s->status & GIT_STATUS_WT_RENAMED)
+			wstatus = 'R';
+		if (s->status & GIT_STATUS_WT_TYPECHANGE)
+			wstatus = 'T';
+
+		if (s->status & GIT_STATUS_IGNORED) {
+			istatus = '!';
+			wstatus = '!';
+		}
+
+		if (istatus == '?' && wstatus == '?')
+			continue;
+
+		/**
+		 * A commit in a tree is how submodules are stored, so
+		 * let's go take a look at its status.
+		 */
+		if (s->index_to_workdir &&
+			s->index_to_workdir->new_file.mode == GIT_FILEMODE_COMMIT)
+		{
+			unsigned int smstatus = 0;
+
+			if (!git_submodule_status(&smstatus, repo, s->index_to_workdir->new_file.path,
+						  GIT_SUBMODULE_IGNORE_UNSPECIFIED)) {
+				if (smstatus & GIT_SUBMODULE_STATUS_WD_MODIFIED)
+					extra = " (new commits)";
+				else if (smstatus & GIT_SUBMODULE_STATUS_WD_INDEX_MODIFIED)
+					extra = " (modified content)";
+				else if (smstatus & GIT_SUBMODULE_STATUS_WD_WD_MODIFIED)
+					extra = " (modified content)";
+				else if (smstatus & GIT_SUBMODULE_STATUS_WD_UNTRACKED)
+					extra = " (untracked content)";
+			}
+		}
+
+		/**
+		 * Now that we have all the information, format the output.
+		 */
+
+		if (s->head_to_index) {
+			a = s->head_to_index->old_file.path;
+			b = s->head_to_index->new_file.path;
+		}
+		if (s->index_to_workdir) {
+			if (!a)
+				a = s->index_to_workdir->old_file.path;
+			if (!b)
+				b = s->index_to_workdir->old_file.path;
+			c = s->index_to_workdir->new_file.path;
+		}
+
+		if (istatus == 'R') {
+			if (wstatus == 'R')
+				printf("%c%c %s %s %s%s\n", istatus, wstatus, a, b, c, extra);
+			else
+				printf("%c%c %s %s%s\n", istatus, wstatus, a, b, extra);
+		} else {
+			if (wstatus == 'R')
+				printf("%c%c %s %s%s\n", istatus, wstatus, a, c, extra);
+			else
+				printf("%c%c %s%s\n", istatus, wstatus, a, extra);
+		}
+	}
+
+	for (i = 0; i < maxi; ++i) {
+		s = git_status_byindex(status, i);
+
+		if (s->status == GIT_STATUS_WT_NEW)
+			printf("?? %s\n", s->index_to_workdir->old_file.path);
+	}
+}
+
+static int print_submod(git_submodule *sm, const char *name, void *payload)
+{
+	int *count = payload;
+	(void)name;
+
+	if (*count == 0)
+		printf("# Submodules\n");
+	(*count)++;
+
+	printf("# - submodule '%s' at %s\n",
+		git_submodule_name(sm), git_submodule_path(sm));
+
+	return 0;
+}
+
+/**
+ * Parse options that git's status command supports.
+ */
+static void parse_opts(struct opts *o, int argc, char *argv[])
+{
+	struct args_info args = ARGS_INFO_INIT;
+
+	for (args.pos = 1; args.pos < argc; ++args.pos) {
+		char *a = argv[args.pos];
+
+		if (a[0] != '-') {
+			if (o->npaths < MAX_PATHSPEC)
+				o->pathspec[o->npaths++] = a;
+			else
+				fatal("Example only supports a limited pathspec", NULL);
+		}
+		else if (!strcmp(a, "-s") || !strcmp(a, "--short"))
+			o->format = FORMAT_SHORT;
+		else if (!strcmp(a, "--long"))
+			o->format = FORMAT_LONG;
+		else if (!strcmp(a, "--porcelain"))
+			o->format = FORMAT_PORCELAIN;
+		else if (!strcmp(a, "-b") || !strcmp(a, "--branch"))
+			o->showbranch = 1;
+		else if (!strcmp(a, "-z")) {
+			o->zterm = 1;
+			if (o->format == FORMAT_DEFAULT)
+				o->format = FORMAT_PORCELAIN;
+		}
+		else if (!strcmp(a, "--ignored"))
+			o->statusopt.flags |= GIT_STATUS_OPT_INCLUDE_IGNORED;
+		else if (!strcmp(a, "-uno") ||
+				 !strcmp(a, "--untracked-files=no"))
+			o->statusopt.flags &= ~GIT_STATUS_OPT_INCLUDE_UNTRACKED;
+		else if (!strcmp(a, "-unormal") ||
+				 !strcmp(a, "--untracked-files=normal"))
+			o->statusopt.flags |= GIT_STATUS_OPT_INCLUDE_UNTRACKED;
+		else if (!strcmp(a, "-uall") ||
+				 !strcmp(a, "--untracked-files=all"))
+			o->statusopt.flags |= GIT_STATUS_OPT_INCLUDE_UNTRACKED |
+				GIT_STATUS_OPT_RECURSE_UNTRACKED_DIRS;
+		else if (!strcmp(a, "--ignore-submodules=all"))
+			o->statusopt.flags |= GIT_STATUS_OPT_EXCLUDE_SUBMODULES;
+		else if (!strncmp(a, "--git-dir=", strlen("--git-dir=")))
+			o->repodir = a + strlen("--git-dir=");
+		else if (!strcmp(a, "--repeat"))
+			o->repeat = 10;
+		else if (match_int_arg(&o->repeat, &args, "--repeat", 0))
+			/* okay */;
+		else if (!strcmp(a, "--list-submodules"))
+			o->showsubmod = 1;
+		else
+			check_lg2(-1, "Unsupported option", a);
+	}
+
+	if (o->format == FORMAT_DEFAULT)
+		o->format = FORMAT_LONG;
+	if (o->format == FORMAT_LONG)
+		o->showbranch = 1;
+	if (o->npaths > 0) {
+		o->statusopt.pathspec.strings = o->pathspec;
+		o->statusopt.pathspec.count   = o->npaths;
+	}
+}

vendor/libgit2-sys/libgit2/examples/tag.c

diff --git a/vendor/libgit2-sys/libgit2/examples/tag.c b/vendor/libgit2-sys/libgit2/examples/tag.c
new file mode 100644
index 0000000..c6a70d9
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/tag.c
@@ -0,0 +1,319 @@
+/*
+ * libgit2 "tag" example - shows how to list, create and delete tags
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include "common.h"
+
+/**
+ * The following example partially reimplements the `git tag` command
+ * and some of its options.
+ *
+ * These commands should work:
+
+ * - Tag name listing (`tag`)
+ * - Filtered tag listing with messages (`tag -n3 -l "v0.1*"`)
+ * - Lightweight tag creation (`tag test v0.18.0`)
+ * - Tag creation (`tag -a -m "Test message" test v0.18.0`)
+ * - Tag deletion (`tag -d test`)
+ *
+ * The command line parsing logic is simplified and doesn't handle
+ * all of the use cases.
+ */
+
+/** tag_options represents the parsed command line options */
+typedef struct {
+	const char *message;
+	const char *pattern;
+	const char *tag_name;
+	const char *target;
+	int num_lines;
+	int force;
+} tag_options;
+
+/** tag_state represents the current program state for dragging around */
+typedef struct {
+	git_repository *repo;
+	tag_options *opts;
+} tag_state;
+
+/** An action to execute based on the command line arguments */
+typedef void (*tag_action)(tag_state *state);
+typedef struct args_info args_info;
+
+static void check(int result, const char *message)
+{
+	if (result) fatal(message, NULL);
+}
+
+/** Tag listing: Print individual message lines */
+static void print_list_lines(const char *message, const tag_state *state)
+{
+	const char *msg = message;
+	int num = state->opts->num_lines - 1;
+
+	if (!msg) return;
+
+	/** first line - headline */
+	while(*msg && *msg != '\n') printf("%c", *msg++);
+
+	/** skip over new lines */
+	while(*msg && *msg == '\n') msg++;
+
+	printf("\n");
+
+	/** print just headline? */
+	if (num == 0) return;
+	if (*msg && msg[1]) printf("\n");
+
+	/** print individual commit/tag lines */
+	while (*msg && num-- >= 2) {
+		printf("    ");
+
+		while (*msg && *msg != '\n') printf("%c", *msg++);
+
+		/** handle consecutive new lines */
+		if (*msg && *msg == '\n' && msg[1] == '\n') {
+			num--;
+			printf("\n");
+		}
+		while(*msg && *msg == '\n') msg++;
+
+		printf("\n");
+	}
+}
+
+/** Tag listing: Print an actual tag object */
+static void print_tag(git_tag *tag, const tag_state *state)
+{
+	printf("%-16s", git_tag_name(tag));
+
+	if (state->opts->num_lines) {
+		const char *msg = git_tag_message(tag);
+		print_list_lines(msg, state);
+	} else {
+		printf("\n");
+	}
+}
+
+/** Tag listing: Print a commit (target of a lightweight tag) */
+static void print_commit(git_commit *commit, const char *name,
+		const tag_state *state)
+{
+	printf("%-16s", name);
+
+	if (state->opts->num_lines) {
+		const char *msg = git_commit_message(commit);
+		print_list_lines(msg, state);
+	} else {
+		printf("\n");
+	}
+}
+
+/** Tag listing: Fallback, should not happen */
+static void print_name(const char *name)
+{
+	printf("%s\n", name);
+}
+
+/** Tag listing: Lookup tags based on ref name and dispatch to print */
+static int each_tag(const char *name, tag_state *state)
+{
+	git_repository *repo = state->repo;
+	git_object *obj;
+
+	check_lg2(git_revparse_single(&obj, repo, name),
+			"Failed to lookup rev", name);
+
+	switch (git_object_type(obj)) {
+		case GIT_OBJ_TAG:
+			print_tag((git_tag *) obj, state);
+			break;
+		case GIT_OBJ_COMMIT:
+			print_commit((git_commit *) obj, name, state);
+			break;
+		default:
+			print_name(name);
+	}
+
+	git_object_free(obj);
+	return 0;
+}
+
+static void action_list_tags(tag_state *state)
+{
+	const char *pattern = state->opts->pattern;
+	git_strarray tag_names = {0};
+	size_t i;
+
+	check_lg2(git_tag_list_match(&tag_names, pattern ? pattern : "*", state->repo),
+			"Unable to get list of tags", NULL);
+
+	for(i = 0; i < tag_names.count; i++) {
+		each_tag(tag_names.strings[i], state);
+	}
+
+	git_strarray_free(&tag_names);
+}
+
+static void action_delete_tag(tag_state *state)
+{
+	tag_options *opts = state->opts;
+	git_object *obj;
+	git_buf abbrev_oid = {0};
+
+	check(!opts->tag_name, "Name required");
+
+	check_lg2(git_revparse_single(&obj, state->repo, opts->tag_name),
+			"Failed to lookup rev", opts->tag_name);
+
+	check_lg2(git_object_short_id(&abbrev_oid, obj),
+			"Unable to get abbreviated OID", opts->tag_name);
+
+	check_lg2(git_tag_delete(state->repo, opts->tag_name),
+			"Unable to delete tag", opts->tag_name);
+
+	printf("Deleted tag '%s' (was %s)\n", opts->tag_name, abbrev_oid.ptr);
+
+	git_buf_free(&abbrev_oid);
+	git_object_free(obj);
+}
+
+static void action_create_lighweight_tag(tag_state *state)
+{
+	git_repository *repo = state->repo;
+	tag_options *opts = state->opts;
+	git_oid oid;
+	git_object *target;
+
+	check(!opts->tag_name, "Name required");
+
+	if (!opts->target) opts->target = "HEAD";
+
+	check(!opts->target, "Target required");
+
+	check_lg2(git_revparse_single(&target, repo, opts->target),
+			"Unable to resolve spec", opts->target);
+
+	check_lg2(git_tag_create_lightweight(&oid, repo, opts->tag_name,
+				target, opts->force), "Unable to create tag", NULL);
+
+	git_object_free(target);
+}
+
+static void action_create_tag(tag_state *state)
+{
+	git_repository *repo = state->repo;
+	tag_options *opts = state->opts;
+	git_signature *tagger;
+	git_oid oid;
+	git_object *target;
+
+	check(!opts->tag_name, "Name required");
+	check(!opts->message, "Message required");
+
+	if (!opts->target) opts->target = "HEAD";
+
+	check_lg2(git_revparse_single(&target, repo, opts->target),
+			"Unable to resolve spec", opts->target);
+
+	check_lg2(git_signature_default(&tagger, repo),
+			"Unable to create signature", NULL);
+
+	check_lg2(git_tag_create(&oid, repo, opts->tag_name,
+				target, tagger, opts->message, opts->force), "Unable to create tag", NULL);
+
+	git_object_free(target);
+	git_signature_free(tagger);
+}
+
+static void print_usage(void)
+{
+	fprintf(stderr, "usage: see `git help tag`\n");
+	exit(1);
+}
+
+/** Parse command line arguments and choose action to run when done */
+static void parse_options(tag_action *action, tag_options *opts, int argc, char **argv)
+{
+	args_info args = ARGS_INFO_INIT;
+	*action = &action_list_tags;
+
+	for (args.pos = 1; args.pos < argc; ++args.pos) {
+		const char *curr = argv[args.pos];
+
+		if (curr[0] != '-') {
+			if (!opts->tag_name)
+				opts->tag_name = curr;
+			else if (!opts->target)
+				opts->target = curr;
+			else
+				print_usage();
+
+			if (*action != &action_create_tag)
+				*action = &action_create_lighweight_tag;
+		} else if (!strcmp(curr, "-n")) {
+			opts->num_lines = 1;
+			*action = &action_list_tags;
+		} else if (!strcmp(curr, "-a")) {
+			*action = &action_create_tag;
+		} else if (!strcmp(curr, "-f")) {
+			opts->force = 1;
+		} else if (match_int_arg(&opts->num_lines, &args, "-n", 0)) {
+			*action = &action_list_tags;
+		} else if (match_str_arg(&opts->pattern, &args, "-l")) {
+			*action = &action_list_tags;
+		} else if (match_str_arg(&opts->tag_name, &args, "-d")) {
+			*action = &action_delete_tag;
+		} else if (match_str_arg(&opts->message, &args, "-m")) {
+			*action = &action_create_tag;
+		}
+	}
+}
+
+/** Initialize tag_options struct */
+static void tag_options_init(tag_options *opts)
+{
+	memset(opts, 0, sizeof(*opts));
+
+	opts->message   = NULL;
+	opts->pattern   = NULL;
+	opts->tag_name  = NULL;
+	opts->target    = NULL;
+	opts->num_lines = 0;
+	opts->force     = 0;
+}
+
+int main(int argc, char **argv)
+{
+	git_repository *repo;
+	tag_options opts;
+	tag_action action;
+	tag_state state;
+
+	git_libgit2_init();
+
+	check_lg2(git_repository_open_ext(&repo, ".", 0, NULL),
+			"Could not open repository", NULL);
+
+	tag_options_init(&opts);
+	parse_options(&action, &opts, argc, argv);
+
+	state.repo = repo;
+	state.opts = &opts;
+	action(&state);
+
+	git_repository_free(repo);
+	git_libgit2_shutdown();
+
+	return 0;
+}

vendor/libgit2-sys/libgit2/examples/test/test-rev-list.sh

diff --git a/vendor/libgit2-sys/libgit2/examples/test/test-rev-list.sh b/vendor/libgit2-sys/libgit2/examples/test/test-rev-list.sh
new file mode 100755
index 0000000..aa645be
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/examples/test/test-rev-list.sh
@@ -0,0 +1,95 @@
+#!/bin/bash
+
+THIS_FILE="$(readlink -f "$0")"
+ROOT="$(dirname "$(dirname "$(dirname "$THIS_FILE")")")"
+PROGRAM="$ROOT"/examples/rev-list
+LIBDIR="$ROOT"/build
+REPO="$ROOT"/tests/resources/testrepo.git
+
+cd "$REPO"
+
+run () {
+    LD_LIBRARY_PATH="$LIBDIR" "$PROGRAM" "$@"
+}
+
+diff -u - <(run --date-order a4a7dce) <<EOF
+a4a7dce85cf63874e984719f4fdd239f5145052f
+c47800c7266a2be04c571c04d5a6614691ea99bd
+9fd738e8f7967c078dceed8190330fc8648ee56a
+4a202b346bb0fb0db7eff3cffeb3c70babbd2045
+5b5b025afb0b4c913b4c338a42934a3863bf3644
+8496071c1b46c854b31185ea97743be6a8774479
+EOF
+
+out="$(run --topo-order a4a7dce)"
+diff -q - <(echo -n "$out") <<EOF >/dev/null ||
+a4a7dce85cf63874e984719f4fdd239f5145052f
+c47800c7266a2be04c571c04d5a6614691ea99bd
+9fd738e8f7967c078dceed8190330fc8648ee56a
+4a202b346bb0fb0db7eff3cffeb3c70babbd2045
+5b5b025afb0b4c913b4c338a42934a3863bf3644
+8496071c1b46c854b31185ea97743be6a8774479
+EOF
+diff -u - <(echo "$out") <<EOF
+a4a7dce85cf63874e984719f4fdd239f5145052f
+9fd738e8f7967c078dceed8190330fc8648ee56a
+4a202b346bb0fb0db7eff3cffeb3c70babbd2045
+c47800c7266a2be04c571c04d5a6614691ea99bd
+5b5b025afb0b4c913b4c338a42934a3863bf3644
+8496071c1b46c854b31185ea97743be6a8774479
+EOF
+
+diff -u - <(run --date-order --reverse a4a7dce) <<EOF
+8496071c1b46c854b31185ea97743be6a8774479
+5b5b025afb0b4c913b4c338a42934a3863bf3644
+4a202b346bb0fb0db7eff3cffeb3c70babbd2045
+9fd738e8f7967c078dceed8190330fc8648ee56a
+c47800c7266a2be04c571c04d5a6614691ea99bd
+a4a7dce85cf63874e984719f4fdd239f5145052f
+EOF
+
+out=$(run --topo-order --reverse a4a7dce)
+diff -q - <(echo -n "$out") <<EOF >/dev/null ||
+8496071c1b46c854b31185ea97743be6a8774479
+5b5b025afb0b4c913b4c338a42934a3863bf3644
+4a202b346bb0fb0db7eff3cffeb3c70babbd2045
+9fd738e8f7967c078dceed8190330fc8648ee56a
+c47800c7266a2be04c571c04d5a6614691ea99bd
+a4a7dce85cf63874e984719f4fdd239f5145052f
+EOF
+diff -u - <(echo "$out") <<EOF
+8496071c1b46c854b31185ea97743be6a8774479
+5b5b025afb0b4c913b4c338a42934a3863bf3644
+c47800c7266a2be04c571c04d5a6614691ea99bd
+4a202b346bb0fb0db7eff3cffeb3c70babbd2045
+9fd738e8f7967c078dceed8190330fc8648ee56a
+a4a7dce85cf63874e984719f4fdd239f5145052f
+EOF
+
+out="$(run --date-order --topo-order --reverse --reverse a4a7dce)"
+diff -q - <(echo -n "$out") <<EOF >/dev/null ||
+a4a7dce85cf63874e984719f4fdd239f5145052f
+c47800c7266a2be04c571c04d5a6614691ea99bd
+9fd738e8f7967c078dceed8190330fc8648ee56a
+4a202b346bb0fb0db7eff3cffeb3c70babbd2045
+5b5b025afb0b4c913b4c338a42934a3863bf3644
+8496071c1b46c854b31185ea97743be6a8774479
+EOF
+diff -u - <(echo "$out") <<EOF
+a4a7dce85cf63874e984719f4fdd239f5145052f
+9fd738e8f7967c078dceed8190330fc8648ee56a
+4a202b346bb0fb0db7eff3cffeb3c70babbd2045
+c47800c7266a2be04c571c04d5a6614691ea99bd
+5b5b025afb0b4c913b4c338a42934a3863bf3644
+8496071c1b46c854b31185ea97743be6a8774479
+EOF
+
+diff -u - <(run ^9fd738e~2 9fd738e) <<EOF
+9fd738e8f7967c078dceed8190330fc8648ee56a
+4a202b346bb0fb0db7eff3cffeb3c70babbd2045
+EOF
+
+diff -u - <(run --not 9fd738e..9fd738e~2) <<EOF
+9fd738e8f7967c078dceed8190330fc8648ee56a
+4a202b346bb0fb0db7eff3cffeb3c70babbd2045
+EOF

vendor/libgit2-sys/libgit2/git.git-authors

diff --git a/vendor/libgit2-sys/libgit2/git.git-authors b/vendor/libgit2-sys/libgit2/git.git-authors
new file mode 100644
index 0000000..905bdd2
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/git.git-authors
@@ -0,0 +1,77 @@
+# This document lists the authors that have given voice to
+# their decision regarding relicensing the GPL'd code from
+# git.git to the GPL + gcc-exception license used by libgit2.
+#
+# Note that the permission is given for libgit2 use only. For
+# other uses, you must ask each of the contributors yourself.
+#
+# To show the owners of a file in git.git, one can run the
+# following command:
+#
+#  git blame -C -C -M -- file | \
+#    sed -e 's/[^(]*(\([^0-9]*\).*/\1/' -e 's/[\t ]*$//' | \
+#      sort | uniq -c | sort -nr
+#
+# If everyone on the list that produces are on the list in
+# the recently added file "git.git-authors", it *should* be
+# safe to include that code in libgit2, but make sure to
+# read the file to ensure the code doesn't originate from
+# somewhere else.
+#
+# The format of this list is
+# "ok/no/ask/???"<tab>"Author"<space>"<email>"
+#
+# "ok" means the author consents to relicensing all their
+#   contributed code (possibly with some exceptions)
+# "no" means the author does not consent
+# "ask" means that the contributor wants to give/withhold
+#   his/her consent on a patch-by-patch basis.
+# "???" means the person is a prominent contributor who has
+#   not yet made his/her standpoint clear.
+#
+# Please try to keep the list alphabetically ordered. It will
+# help in case we get all 600-ish git.git authors on it.
+#
+# (Paul Kocher is the author of the mozilla-sha1 implementation
+#  but has otherwise not contributed to git.)
+#
+ok	Adam Simpkins <adam@adamsimpkins.net> (http transport)
+ok	Adrian Johnson <ajohnson@redneon.com>
+ok	Alexey Shumkin <alex.crezoff@gmail.com>
+ok	Andreas Ericsson <ae@op5.se>
+ok	Antoine Pelisse <apelisse@gmail.com>
+ok	Boyd Lynn Gerber <gerberb@zenez.com>
+ok	Brandon Casey <drafnel@gmail.com>
+ok	Brian Downing <bdowning@lavos.net>
+ok	Brian Gernhardt <benji@silverinsanity.com>
+ok	Christian Couder <chriscool@tuxfamily.org>
+ok	Daniel Barkalow <barkalow@iabervon.org>
+ok	Elijah Newren <newren@gmail.com>
+ok	Florian Forster <octo@verplant.org>
+ok	Gustaf Hendeby <hendeby@isy.liu.se>
+ok	Holger Weiss <holger@zedat.fu-berlin.de>
+ok	Jeff King <peff@peff.net>
+ok	Johannes Schindelin <Johannes.Schindelin@gmx.de>
+ok	Johannes Sixt <j6t@kdbg.org>
+ask	Jonathan Nieder <jrnieder@gmail.com>
+ok	Jonathan Tan <jonathantanmy@google.com>
+ok	Junio C Hamano <gitster@pobox.com>
+ok	Kristian Høgsberg <krh@redhat.com>
+ok	Linus Torvalds <torvalds@linux-foundation.org>
+ok	Lukas Sandström <lukass@etek.chalmers.se>
+ok	Matthieu Moy <Matthieu.Moy@imag.fr>
+ok	Michael Haggerty <mhagger@alum.mit.edu>
+ok	Nicolas Pitre <nico@fluxnic.net> <nico@cam.org>
+ok	Paolo Bonzini <bonzini@gnu.org>
+ok	Paul Kocher <paul@cryptography.com>
+ok	Peter Hagervall <hager@cs.umu.se>
+ok	Petr Onderka <gsvick@gmail.com>
+ok	Pierre Habouzit <madcoder@debian.org>
+ok	Pieter de Bie <pdebie@ai.rug.nl>
+ok	René Scharfe <rene.scharfe@lsrfire.ath.cx>
+ok	Sebastian Schuberth <sschuberth@gmail.com>
+ok	Shawn O. Pearce <spearce@spearce.org>
+ok	Steffen Prohaska <prohaska@zib.de>
+ok	Sven Verdoolaege <skimo@kotnet.org>
+ask	Thomas Rast <tr@thomasrast.ch> (ok before 6-Oct-2013)
+ok	Torsten Bögershausen <tboegi@web.de>

vendor/libgit2-sys/libgit2/include/git2.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2.h b/vendor/libgit2-sys/libgit2/include/git2.h
new file mode 100644
index 0000000..5f6104e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2.h
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_git_git_h__
+#define INCLUDE_git_git_h__
+
+#include "git2/annotated_commit.h"
+#include "git2/attr.h"
+#include "git2/blob.h"
+#include "git2/blame.h"
+#include "git2/branch.h"
+#include "git2/buffer.h"
+#include "git2/checkout.h"
+#include "git2/cherrypick.h"
+#include "git2/clone.h"
+#include "git2/commit.h"
+#include "git2/common.h"
+#include "git2/config.h"
+#include "git2/describe.h"
+#include "git2/diff.h"
+#include "git2/errors.h"
+#include "git2/filter.h"
+#include "git2/global.h"
+#include "git2/graph.h"
+#include "git2/ignore.h"
+#include "git2/index.h"
+#include "git2/indexer.h"
+#include "git2/merge.h"
+#include "git2/message.h"
+#include "git2/net.h"
+#include "git2/notes.h"
+#include "git2/object.h"
+#include "git2/odb.h"
+#include "git2/odb_backend.h"
+#include "git2/oid.h"
+#include "git2/pack.h"
+#include "git2/patch.h"
+#include "git2/pathspec.h"
+#include "git2/proxy.h"
+#include "git2/rebase.h"
+#include "git2/refdb.h"
+#include "git2/reflog.h"
+#include "git2/refs.h"
+#include "git2/refspec.h"
+#include "git2/remote.h"
+#include "git2/repository.h"
+#include "git2/reset.h"
+#include "git2/revert.h"
+#include "git2/revparse.h"
+#include "git2/revwalk.h"
+#include "git2/signature.h"
+#include "git2/stash.h"
+#include "git2/status.h"
+#include "git2/submodule.h"
+#include "git2/tag.h"
+#include "git2/transport.h"
+#include "git2/transaction.h"
+#include "git2/tree.h"
+#include "git2/types.h"
+#include "git2/version.h"
+#include "git2/worktree.h"
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/annotated_commit.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/annotated_commit.h b/vendor/libgit2-sys/libgit2/include/git2/annotated_commit.h
new file mode 100644
index 0000000..7fb896a5
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/annotated_commit.h
@@ -0,0 +1,116 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_annotated_commit_h__
+#define INCLUDE_git_annotated_commit_h__
+
+#include "common.h"
+#include "repository.h"
+#include "types.h"
+
+/**
+ * @file git2/annotated_commit.h
+ * @brief Git annotated commit routines
+ * @defgroup git_annotated_commit Git annotated commit routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Creates a `git_annotated_commit` from the given reference.
+ * The resulting git_annotated_commit must be freed with
+ * `git_annotated_commit_free`.
+ *
+ * @param out pointer to store the git_annotated_commit result in
+ * @param repo repository that contains the given reference
+ * @param ref reference to use to lookup the git_annotated_commit
+ * @return 0 on success or error code
+ */
+GIT_EXTERN(int) git_annotated_commit_from_ref(
+	git_annotated_commit **out,
+	git_repository *repo,
+	const git_reference *ref);
+
+/**
+ * Creates a `git_annotated_commit` from the given fetch head data.
+ * The resulting git_annotated_commit must be freed with
+ * `git_annotated_commit_free`.
+ *
+ * @param out pointer to store the git_annotated_commit result in
+ * @param repo repository that contains the given commit
+ * @param branch_name name of the (remote) branch
+ * @param remote_url url of the remote
+ * @param id the commit object id of the remote branch
+ * @return 0 on success or error code
+ */
+GIT_EXTERN(int) git_annotated_commit_from_fetchhead(
+	git_annotated_commit **out,
+	git_repository *repo,
+	const char *branch_name,
+	const char *remote_url,
+	const git_oid *id);
+
+/**
+ * Creates a `git_annotated_commit` from the given commit id.
+ * The resulting git_annotated_commit must be freed with
+ * `git_annotated_commit_free`.
+ *
+ * An annotated commit contains information about how it was
+ * looked up, which may be useful for functions like merge or
+ * rebase to provide context to the operation.  For example,
+ * conflict files will include the name of the source or target
+ * branches being merged.  It is therefore preferable to use the
+ * most specific function (eg `git_annotated_commit_from_ref`)
+ * instead of this one when that data is known.
+ *
+ * @param out pointer to store the git_annotated_commit result in
+ * @param repo repository that contains the given commit
+ * @param id the commit object id to lookup
+ * @return 0 on success or error code
+ */
+GIT_EXTERN(int) git_annotated_commit_lookup(
+	git_annotated_commit **out,
+	git_repository *repo,
+	const git_oid *id);
+
+/**
+ * Creates a `git_annotated_comit` from a revision string.
+ *
+ * See `man gitrevisions`, or
+ * http://git-scm.com/docs/git-rev-parse.html#_specifying_revisions for
+ * information on the syntax accepted.
+ *
+ * @param out pointer to store the git_annotated_commit result in
+ * @param repo repository that contains the given commit
+ * @param revspec the extended sha syntax string to use to lookup the commit
+ * @return 0 on success or error code
+ */
+GIT_EXTERN(int) git_annotated_commit_from_revspec(
+	git_annotated_commit **out,
+	git_repository *repo,
+	const char *revspec);
+
+/**
+ * Gets the commit ID that the given `git_annotated_commit` refers to.
+ *
+ * @param commit the given annotated commit
+ * @return commit id
+ */
+GIT_EXTERN(const git_oid *) git_annotated_commit_id(
+	const git_annotated_commit *commit);
+
+/**
+ * Frees a `git_annotated_commit`.
+ *
+ * @param commit annotated commit to free
+ */
+GIT_EXTERN(void) git_annotated_commit_free(
+	git_annotated_commit *commit);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/attr.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/attr.h b/vendor/libgit2-sys/libgit2/include/git2/attr.h
new file mode 100644
index 0000000..0238f3d
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/attr.h
@@ -0,0 +1,245 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_attr_h__
+#define INCLUDE_git_attr_h__
+
+#include "common.h"
+#include "types.h"
+
+/**
+ * @file git2/attr.h
+ * @brief Git attribute management routines
+ * @defgroup git_attr Git attribute management routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * GIT_ATTR_TRUE checks if an attribute is set on.  In core git
+ * parlance, this the value for "Set" attributes.
+ *
+ * For example, if the attribute file contains:
+ *
+ *    *.c foo
+ *
+ * Then for file `xyz.c` looking up attribute "foo" gives a value for
+ * which `GIT_ATTR_TRUE(value)` is true.
+ */
+#define GIT_ATTR_TRUE(attr)	(git_attr_value(attr) == GIT_ATTR_TRUE_T)
+
+/**
+ * GIT_ATTR_FALSE checks if an attribute is set off.  In core git
+ * parlance, this is the value for attributes that are "Unset" (not to
+ * be confused with values that a "Unspecified").
+ *
+ * For example, if the attribute file contains:
+ *
+ *    *.h -foo
+ *
+ * Then for file `zyx.h` looking up attribute "foo" gives a value for
+ * which `GIT_ATTR_FALSE(value)` is true.
+ */
+#define GIT_ATTR_FALSE(attr) (git_attr_value(attr) == GIT_ATTR_FALSE_T)
+
+/**
+ * GIT_ATTR_UNSPECIFIED checks if an attribute is unspecified.  This
+ * may be due to the attribute not being mentioned at all or because
+ * the attribute was explicitly set unspecified via the `!` operator.
+ *
+ * For example, if the attribute file contains:
+ *
+ *    *.c foo
+ *    *.h -foo
+ *    onefile.c !foo
+ *
+ * Then for `onefile.c` looking up attribute "foo" yields a value with
+ * `GIT_ATTR_UNSPECIFIED(value)` of true.  Also, looking up "foo" on
+ * file `onefile.rb` or looking up "bar" on any file will all give
+ * `GIT_ATTR_UNSPECIFIED(value)` of true.
+ */
+#define GIT_ATTR_UNSPECIFIED(attr) (git_attr_value(attr) == GIT_ATTR_UNSPECIFIED_T)
+
+/**
+ * GIT_ATTR_HAS_VALUE checks if an attribute is set to a value (as
+ * opposed to TRUE, FALSE or UNSPECIFIED).  This would be the case if
+ * for a file with something like:
+ *
+ *    *.txt eol=lf
+ *
+ * Given this, looking up "eol" for `onefile.txt` will give back the
+ * string "lf" and `GIT_ATTR_SET_TO_VALUE(attr)` will return true.
+ */
+#define GIT_ATTR_HAS_VALUE(attr) (git_attr_value(attr) == GIT_ATTR_VALUE_T)
+
+/**
+ * Possible states for an attribute
+ */
+typedef enum {
+	GIT_ATTR_UNSPECIFIED_T = 0, /**< The attribute has been left unspecified */
+	GIT_ATTR_TRUE_T,  /**< The attribute has been set */
+	GIT_ATTR_FALSE_T, /**< The attribute has been unset */
+	GIT_ATTR_VALUE_T, /**< This attribute has a value */
+} git_attr_t;
+
+/**
+ * Return the value type for a given attribute.
+ *
+ * This can be either `TRUE`, `FALSE`, `UNSPECIFIED` (if the attribute
+ * was not set at all), or `VALUE`, if the attribute was set to an
+ * actual string.
+ *
+ * If the attribute has a `VALUE` string, it can be accessed normally
+ * as a NULL-terminated C string.
+ *
+ * @param attr The attribute
+ * @return the value type for the attribute
+ */
+GIT_EXTERN(git_attr_t) git_attr_value(const char *attr);
+
+/**
+ * Check attribute flags: Reading values from index and working directory.
+ *
+ * When checking attributes, it is possible to check attribute files
+ * in both the working directory (if there is one) and the index (if
+ * there is one).  You can explicitly choose where to check and in
+ * which order using the following flags.
+ *
+ * Core git usually checks the working directory then the index,
+ * except during a checkout when it checks the index first.  It will
+ * use index only for creating archives or for a bare repo (if an
+ * index has been specified for the bare repo).
+ */
+#define GIT_ATTR_CHECK_FILE_THEN_INDEX	0
+#define GIT_ATTR_CHECK_INDEX_THEN_FILE	1
+#define GIT_ATTR_CHECK_INDEX_ONLY		2
+
+/**
+ * Check attribute flags: Using the system attributes file.
+ *
+ * Normally, attribute checks include looking in the /etc (or system
+ * equivalent) directory for a `gitattributes` file.  Passing this
+ * flag will cause attribute checks to ignore that file.
+ */
+#define GIT_ATTR_CHECK_NO_SYSTEM		(1 << 2)
+
+/**
+ * Look up the value of one git attribute for path.
+ *
+ * @param value_out Output of the value of the attribute.  Use the GIT_ATTR_...
+ *             macros to test for TRUE, FALSE, UNSPECIFIED, etc. or just
+ *             use the string value for attributes set to a value.  You
+ *             should NOT modify or free this value.
+ * @param repo The repository containing the path.
+ * @param flags A combination of GIT_ATTR_CHECK... flags.
+ * @param path The path to check for attributes.  Relative paths are
+ *             interpreted relative to the repo root.  The file does
+ *             not have to exist, but if it does not, then it will be
+ *             treated as a plain file (not a directory).
+ * @param name The name of the attribute to look up.
+ */
+GIT_EXTERN(int) git_attr_get(
+	const char **value_out,
+	git_repository *repo,
+	uint32_t flags,
+	const char *path,
+	const char *name);
+
+/**
+ * Look up a list of git attributes for path.
+ *
+ * Use this if you have a known list of attributes that you want to
+ * look up in a single call.  This is somewhat more efficient than
+ * calling `git_attr_get()` multiple times.
+ *
+ * For example, you might write:
+ *
+ *     const char *attrs[] = { "crlf", "diff", "foo" };
+ *     const char **values[3];
+ *     git_attr_get_many(values, repo, 0, "my/fun/file.c", 3, attrs);
+ *
+ * Then you could loop through the 3 values to get the settings for
+ * the three attributes you asked about.
+ *
+ * @param values_out An array of num_attr entries that will have string
+ *             pointers written into it for the values of the attributes.
+ *             You should not modify or free the values that are written
+ *             into this array (although of course, you should free the
+ *             array itself if you allocated it).
+ * @param repo The repository containing the path.
+ * @param flags A combination of GIT_ATTR_CHECK... flags.
+ * @param path The path inside the repo to check attributes.  This
+ *             does not have to exist, but if it does not, then
+ *             it will be treated as a plain file (i.e. not a directory).
+ * @param num_attr The number of attributes being looked up
+ * @param names An array of num_attr strings containing attribute names.
+ */
+GIT_EXTERN(int) git_attr_get_many(
+	const char **values_out,
+	git_repository *repo,
+	uint32_t flags,
+	const char *path,
+	size_t num_attr,
+	const char **names);
+
+typedef int (*git_attr_foreach_cb)(const char *name, const char *value, void *payload);
+
+/**
+ * Loop over all the git attributes for a path.
+ *
+ * @param repo The repository containing the path.
+ * @param flags A combination of GIT_ATTR_CHECK... flags.
+ * @param path Path inside the repo to check attributes.  This does not have
+ *             to exist, but if it does not, then it will be treated as a
+ *             plain file (i.e. not a directory).
+ * @param callback Function to invoke on each attribute name and value.  The
+ *             value may be NULL is the attribute is explicitly set to
+ *             UNSPECIFIED using the '!' sign.  Callback will be invoked
+ *             only once per attribute name, even if there are multiple
+ *             rules for a given file.  The highest priority rule will be
+ *             used.  Return a non-zero value from this to stop looping.
+ *             The value will be returned from `git_attr_foreach`.
+ * @param payload Passed on as extra parameter to callback function.
+ * @return 0 on success, non-zero callback return value, or error code
+ */
+GIT_EXTERN(int) git_attr_foreach(
+	git_repository *repo,
+	uint32_t flags,
+	const char *path,
+	git_attr_foreach_cb callback,
+	void *payload);
+
+/**
+ * Flush the gitattributes cache.
+ *
+ * Call this if you have reason to believe that the attributes files on
+ * disk no longer match the cached contents of memory.  This will cause
+ * the attributes files to be reloaded the next time that an attribute
+ * access function is called.
+ */
+GIT_EXTERN(void) git_attr_cache_flush(
+	git_repository *repo);
+
+/**
+ * Add a macro definition.
+ *
+ * Macros will automatically be loaded from the top level `.gitattributes`
+ * file of the repository (plus the build-in "binary" macro).  This
+ * function allows you to add others.  For example, to add the default
+ * macro, you would call:
+ *
+ *     git_attr_add_macro(repo, "binary", "-diff -crlf");
+ */
+GIT_EXTERN(int) git_attr_add_macro(
+	git_repository *repo,
+	const char *name,
+	const char *values);
+
+/** @} */
+GIT_END_DECL
+#endif
+

vendor/libgit2-sys/libgit2/include/git2/blame.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/blame.h b/vendor/libgit2-sys/libgit2/include/git2/blame.h
new file mode 100644
index 0000000..84bb7f9
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/blame.h
@@ -0,0 +1,212 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_git_blame_h__
+#define INCLUDE_git_blame_h__
+
+#include "common.h"
+#include "oid.h"
+
+/**
+ * @file git2/blame.h
+ * @brief Git blame routines
+ * @defgroup git_blame Git blame routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Flags for indicating option behavior for git_blame APIs.
+ */
+typedef enum {
+	/** Normal blame, the default */
+	GIT_BLAME_NORMAL = 0,
+	/** Track lines that have moved within a file (like `git blame -M`).
+	 * NOT IMPLEMENTED. */
+	GIT_BLAME_TRACK_COPIES_SAME_FILE = (1<<0),
+	/** Track lines that have moved across files in the same commit (like `git blame -C`).
+	 * NOT IMPLEMENTED. */
+	GIT_BLAME_TRACK_COPIES_SAME_COMMIT_MOVES = (1<<1),
+	/** Track lines that have been copied from another file that exists in the
+	 * same commit (like `git blame -CC`). Implies SAME_FILE.
+	 * NOT IMPLEMENTED. */
+	GIT_BLAME_TRACK_COPIES_SAME_COMMIT_COPIES = (1<<2),
+	/** Track lines that have been copied from another file that exists in *any*
+	 * commit (like `git blame -CCC`). Implies SAME_COMMIT_COPIES.
+	 * NOT IMPLEMENTED. */
+	GIT_BLAME_TRACK_COPIES_ANY_COMMIT_COPIES = (1<<3),
+	/** Restrict the search of commits to those reachable following only the
+	 * first parents. */
+	GIT_BLAME_FIRST_PARENT = (1<<4),
+} git_blame_flag_t;
+
+/**
+ * Blame options structure
+ *
+ * Use zeros to indicate default settings.  It's easiest to use the
+ * `GIT_BLAME_OPTIONS_INIT` macro:
+ *     git_blame_options opts = GIT_BLAME_OPTIONS_INIT;
+ *
+ * - `flags` is a combination of the `git_blame_flag_t` values above.
+ * - `min_match_characters` is the lower bound on the number of alphanumeric
+ *   characters that must be detected as moving/copying within a file for it to
+ *   associate those lines with the parent commit. The default value is 20.
+ *   This value only takes effect if any of the `GIT_BLAME_TRACK_COPIES_*`
+ *   flags are specified.
+ * - `newest_commit` is the id of the newest commit to consider.  The default
+ *                   is HEAD.
+ * - `oldest_commit` is the id of the oldest commit to consider.  The default
+ *                   is the first commit encountered with a NULL parent.
+ *	- `min_line` is the first line in the file to blame.  The default is 1 (line
+ *	             numbers start with 1).
+ *	- `max_line` is the last line in the file to blame.  The default is the last
+ *	             line of the file.
+ */
+typedef struct git_blame_options {
+	unsigned int version;
+
+	uint32_t flags;
+	uint16_t min_match_characters;
+	git_oid newest_commit;
+	git_oid oldest_commit;
+	size_t min_line;
+	size_t max_line;
+} git_blame_options;
+
+#define GIT_BLAME_OPTIONS_VERSION 1
+#define GIT_BLAME_OPTIONS_INIT {GIT_BLAME_OPTIONS_VERSION}
+
+/**
+ * Initializes a `git_blame_options` with default values. Equivalent to
+ * creating an instance with GIT_BLAME_OPTIONS_INIT.
+ *
+ * @param opts The `git_blame_options` struct to initialize
+ * @param version Version of struct; pass `GIT_BLAME_OPTIONS_VERSION`
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_blame_init_options(
+	git_blame_options *opts,
+	unsigned int version);
+
+/**
+ * Structure that represents a blame hunk.
+ *
+ * - `lines_in_hunk` is the number of lines in this hunk
+ * - `final_commit_id` is the OID of the commit where this line was last
+ *   changed.
+ * - `final_start_line_number` is the 1-based line number where this hunk
+ *   begins, in the final version of the file
+ * - `orig_commit_id` is the OID of the commit where this hunk was found.  This
+ *   will usually be the same as `final_commit_id`, except when
+ *   `GIT_BLAME_TRACK_COPIES_ANY_COMMIT_COPIES` has been specified.
+ * - `orig_path` is the path to the file where this hunk originated, as of the
+ *   commit specified by `orig_commit_id`.
+ * - `orig_start_line_number` is the 1-based line number where this hunk begins
+ *   in the file named by `orig_path` in the commit specified by
+ *   `orig_commit_id`.
+ * - `boundary` is 1 iff the hunk has been tracked to a boundary commit (the
+ *   root, or the commit specified in git_blame_options.oldest_commit)
+ */
+typedef struct git_blame_hunk {
+	size_t lines_in_hunk;
+
+	git_oid final_commit_id;
+	size_t final_start_line_number;
+	git_signature *final_signature;
+
+	git_oid orig_commit_id;
+	const char *orig_path;
+	size_t orig_start_line_number;
+	git_signature *orig_signature;
+
+	char boundary;
+} git_blame_hunk;
+
+
+/* Opaque structure to hold blame results */
+typedef struct git_blame git_blame;
+
+/**
+ * Gets the number of hunks that exist in the blame structure.
+ */
+GIT_EXTERN(uint32_t) git_blame_get_hunk_count(git_blame *blame);
+
+/**
+ * Gets the blame hunk at the given index.
+ *
+ * @param blame the blame structure to query
+ * @param index index of the hunk to retrieve
+ * @return the hunk at the given index, or NULL on error
+ */
+GIT_EXTERN(const git_blame_hunk*) git_blame_get_hunk_byindex(
+		git_blame *blame,
+		uint32_t index);
+
+/**
+ * Gets the hunk that relates to the given line number in the newest commit.
+ *
+ * @param blame the blame structure to query
+ * @param lineno the (1-based) line number to find a hunk for
+ * @return the hunk that contains the given line, or NULL on error
+ */
+GIT_EXTERN(const git_blame_hunk*) git_blame_get_hunk_byline(
+		git_blame *blame,
+		size_t lineno);
+
+/**
+ * Get the blame for a single file.
+ *
+ * @param out pointer that will receive the blame object
+ * @param repo repository whose history is to be walked
+ * @param path path to file to consider
+ * @param options options for the blame operation.  If NULL, this is treated as
+ *                though GIT_BLAME_OPTIONS_INIT were passed.
+ * @return 0 on success, or an error code. (use giterr_last for information
+ *         about the error.)
+ */
+GIT_EXTERN(int) git_blame_file(
+		git_blame **out,
+		git_repository *repo,
+		const char *path,
+		git_blame_options *options);
+
+
+/**
+ * Get blame data for a file that has been modified in memory. The `reference`
+ * parameter is a pre-calculated blame for the in-odb history of the file. This
+ * means that once a file blame is completed (which can be expensive), updating
+ * the buffer blame is very fast.
+ *
+ * Lines that differ between the buffer and the committed version are marked as
+ * having a zero OID for their final_commit_id.
+ *
+ * @param out pointer that will receive the resulting blame data
+ * @param reference cached blame from the history of the file (usually the output
+ *                  from git_blame_file)
+ * @param buffer the (possibly) modified contents of the file
+ * @param buffer_len number of valid bytes in the buffer
+ * @return 0 on success, or an error code. (use giterr_last for information
+ *         about the error)
+ */
+GIT_EXTERN(int) git_blame_buffer(
+		git_blame **out,
+		git_blame *reference,
+		const char *buffer,
+		size_t buffer_len);
+
+/**
+ * Free memory allocated by git_blame_file or git_blame_buffer.
+ *
+ * @param blame the blame structure to free
+ */
+GIT_EXTERN(void) git_blame_free(git_blame *blame);
+
+/** @} */
+GIT_END_DECL
+#endif
+

vendor/libgit2-sys/libgit2/include/git2/blob.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/blob.h b/vendor/libgit2-sys/libgit2/include/git2/blob.h
new file mode 100644
index 0000000..70204c4
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/blob.h
@@ -0,0 +1,232 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_blob_h__
+#define INCLUDE_git_blob_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+#include "object.h"
+#include "buffer.h"
+
+/**
+ * @file git2/blob.h
+ * @brief Git blob load and write routines
+ * @defgroup git_blob Git blob load and write routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Lookup a blob object from a repository.
+ *
+ * @param blob pointer to the looked up blob
+ * @param repo the repo to use when locating the blob.
+ * @param id identity of the blob to locate.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_blob_lookup(git_blob **blob, git_repository *repo, const git_oid *id);
+
+/**
+ * Lookup a blob object from a repository,
+ * given a prefix of its identifier (short id).
+ *
+ * @see git_object_lookup_prefix
+ *
+ * @param blob pointer to the looked up blob
+ * @param repo the repo to use when locating the blob.
+ * @param id identity of the blob to locate.
+ * @param len the length of the short identifier
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_blob_lookup_prefix(git_blob **blob, git_repository *repo, const git_oid *id, size_t len);
+
+/**
+ * Close an open blob
+ *
+ * This is a wrapper around git_object_free()
+ *
+ * IMPORTANT:
+ * It *is* necessary to call this method when you stop
+ * using a blob. Failure to do so will cause a memory leak.
+ *
+ * @param blob the blob to close
+ */
+GIT_EXTERN(void) git_blob_free(git_blob *blob);
+
+/**
+ * Get the id of a blob.
+ *
+ * @param blob a previously loaded blob.
+ * @return SHA1 hash for this blob.
+ */
+GIT_EXTERN(const git_oid *) git_blob_id(const git_blob *blob);
+
+/**
+ * Get the repository that contains the blob.
+ *
+ * @param blob A previously loaded blob.
+ * @return Repository that contains this blob.
+ */
+GIT_EXTERN(git_repository *) git_blob_owner(const git_blob *blob);
+
+/**
+ * Get a read-only buffer with the raw content of a blob.
+ *
+ * A pointer to the raw content of a blob is returned;
+ * this pointer is owned internally by the object and shall
+ * not be free'd. The pointer may be invalidated at a later
+ * time.
+ *
+ * @param blob pointer to the blob
+ * @return the pointer
+ */
+GIT_EXTERN(const void *) git_blob_rawcontent(const git_blob *blob);
+
+/**
+ * Get the size in bytes of the contents of a blob
+ *
+ * @param blob pointer to the blob
+ * @return size on bytes
+ */
+GIT_EXTERN(git_off_t) git_blob_rawsize(const git_blob *blob);
+
+/**
+ * Get a buffer with the filtered content of a blob.
+ *
+ * This applies filters as if the blob was being checked out to the
+ * working directory under the specified filename.  This may apply
+ * CRLF filtering or other types of changes depending on the file
+ * attributes set for the blob and the content detected in it.
+ *
+ * The output is written into a `git_buf` which the caller must free
+ * when done (via `git_buf_free`).
+ *
+ * If no filters need to be applied, then the `out` buffer will just
+ * be populated with a pointer to the raw content of the blob.  In
+ * that case, be careful to *not* free the blob until done with the
+ * buffer or copy it into memory you own.
+ *
+ * @param out The git_buf to be filled in
+ * @param blob Pointer to the blob
+ * @param as_path Path used for file attribute lookups, etc.
+ * @param check_for_binary_data Should this test if blob content contains
+ *        NUL bytes / looks like binary data before applying filters?
+ * @return 0 on success or an error code
+ */
+GIT_EXTERN(int) git_blob_filtered_content(
+	git_buf *out,
+	git_blob *blob,
+	const char *as_path,
+	int check_for_binary_data);
+
+/**
+ * Read a file from the working folder of a repository
+ * and write it to the Object Database as a loose blob
+ *
+ * @param id return the id of the written blob
+ * @param repo repository where the blob will be written.
+ *	this repository cannot be bare
+ * @param relative_path file from which the blob will be created,
+ *	relative to the repository's working dir
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_blob_create_fromworkdir(git_oid *id, git_repository *repo, const char *relative_path);
+
+/**
+ * Read a file from the filesystem and write its content
+ * to the Object Database as a loose blob
+ *
+ * @param id return the id of the written blob
+ * @param repo repository where the blob will be written.
+ *	this repository can be bare or not
+ * @param path file from which the blob will be created
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_blob_create_fromdisk(git_oid *id, git_repository *repo, const char *path);
+
+/**
+ * Create a stream to write a new blob into the object db
+ *
+ * This function may need to buffer the data on disk and will in
+ * general not be the right choice if you know the size of the data
+ * to write. If you have data in memory, use
+ * `git_blob_create_frombuffer()`. If you do not, but know the size of
+ * the contents (and don't want/need to perform filtering), use
+ * `git_odb_open_wstream()`.
+ *
+ * Don't close this stream yourself but pass it to
+ * `git_blob_create_fromstream_commit()` to commit the write to the
+ * object db and get the object id.
+ *
+ * If the `hintpath` parameter is filled, it will be used to determine
+ * what git filters should be applied to the object before it is written
+ * to the object database.
+ *
+ * @param out the stream into which to write
+ * @param repo Repository where the blob will be written.
+ *        This repository can be bare or not.
+ * @param hintpath If not NULL, will be used to select data filters
+ *        to apply onto the content of the blob to be created.
+ * @return 0 or error code
+ */
+GIT_EXTERN(int) git_blob_create_fromstream(
+	git_writestream **out,
+	git_repository *repo,
+	const char *hintpath);
+
+/**
+ * Close the stream and write the blob to the object db
+ *
+ * The stream will be closed and freed.
+ *
+ * @param out the id of the new blob
+ * @param stream the stream to close
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_blob_create_fromstream_commit(
+	git_oid *out,
+	git_writestream *stream);
+
+/**
+ * Write an in-memory buffer to the ODB as a blob
+ *
+ * @param id return the id of the written blob
+ * @param repo repository where to blob will be written
+ * @param buffer data to be written into the blob
+ * @param len length of the data
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_blob_create_frombuffer(
+	git_oid *id, git_repository *repo, const void *buffer, size_t len);
+
+/**
+ * Determine if the blob content is most certainly binary or not.
+ *
+ * The heuristic used to guess if a file is binary is taken from core git:
+ * Searching for NUL bytes and looking for a reasonable ratio of printable
+ * to non-printable characters among the first 8000 bytes.
+ *
+ * @param blob The blob which content should be analyzed
+ * @return 1 if the content of the blob is detected
+ * as binary; 0 otherwise.
+ */
+GIT_EXTERN(int) git_blob_is_binary(const git_blob *blob);
+
+/**
+ * Create an in-memory copy of a blob. The copy must be explicitly
+ * free'd or it will leak.
+ *
+ * @param out Pointer to store the copy of the object
+ * @param source Original object to copy
+ */
+GIT_EXTERN(int) git_blob_dup(git_blob **out, git_blob *source);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/branch.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/branch.h b/vendor/libgit2-sys/libgit2/include/git2/branch.h
new file mode 100644
index 0000000..88fe723
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/branch.h
@@ -0,0 +1,292 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_branch_h__
+#define INCLUDE_git_branch_h__
+
+#include "common.h"
+#include "oid.h"
+#include "types.h"
+
+/**
+ * @file git2/branch.h
+ * @brief Git branch parsing routines
+ * @defgroup git_branch Git branch management
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Create a new branch pointing at a target commit
+ *
+ * A new direct reference will be created pointing to
+ * this target commit. If `force` is true and a reference
+ * already exists with the given name, it'll be replaced.
+ *
+ * The returned reference must be freed by the user.
+ *
+ * The branch name will be checked for validity.
+ * See `git_tag_create()` for rules about valid names.
+ *
+ * @param out Pointer where to store the underlying reference.
+ *
+ * @param branch_name Name for the branch; this name is
+ * validated for consistency. It should also not conflict with
+ * an already existing branch name.
+ *
+ * @param target Commit to which this branch should point. This object
+ * must belong to the given `repo`.
+ *
+ * @param force Overwrite existing branch.
+ *
+ * @return 0, GIT_EINVALIDSPEC or an error code.
+ * A proper reference is written in the refs/heads namespace
+ * pointing to the provided target commit.
+ */
+GIT_EXTERN(int) git_branch_create(
+	git_reference **out,
+	git_repository *repo,
+	const char *branch_name,
+	const git_commit *target,
+	int force);
+
+/**
+ * Create a new branch pointing at a target commit
+ *
+ * This behaves like `git_branch_create()` but takes an annotated
+ * commit, which lets you specify which extended sha syntax string was
+ * specified by a user, allowing for more exact reflog messages.
+ *
+ * See the documentation for `git_branch_create()`.
+ *
+ * @see git_branch_create
+ */
+GIT_EXTERN(int) git_branch_create_from_annotated(
+	git_reference **ref_out,
+	git_repository *repository,
+	const char *branch_name,
+	const git_annotated_commit *commit,
+	int force);
+
+/**
+ * Delete an existing branch reference.
+ *
+ * If the branch is successfully deleted, the passed reference
+ * object will be invalidated. The reference must be freed manually
+ * by the user.
+ *
+ * @param branch A valid reference representing a branch
+ * @return 0 on success, or an error code.
+ */
+GIT_EXTERN(int) git_branch_delete(git_reference *branch);
+
+/** Iterator type for branches */
+typedef struct git_branch_iterator git_branch_iterator;
+
+/**
+ * Create an iterator which loops over the requested branches.
+ *
+ * @param out the iterator
+ * @param repo Repository where to find the branches.
+ * @param list_flags Filtering flags for the branch
+ * listing. Valid values are GIT_BRANCH_LOCAL, GIT_BRANCH_REMOTE
+ * or GIT_BRANCH_ALL.
+ *
+ * @return 0 on success  or an error code
+ */
+GIT_EXTERN(int) git_branch_iterator_new(
+	git_branch_iterator **out,
+	git_repository *repo,
+	git_branch_t list_flags);
+
+/**
+ * Retrieve the next branch from the iterator
+ *
+ * @param out the reference
+ * @param out_type the type of branch (local or remote-tracking)
+ * @param iter the branch iterator
+ * @return 0 on success, GIT_ITEROVER if there are no more branches or an error code.
+ */
+GIT_EXTERN(int) git_branch_next(git_reference **out, git_branch_t *out_type, git_branch_iterator *iter);
+
+/**
+ * Free a branch iterator
+ *
+ * @param iter the iterator to free
+ */
+GIT_EXTERN(void) git_branch_iterator_free(git_branch_iterator *iter);
+
+/**
+ * Move/rename an existing local branch reference.
+ *
+ * The new branch name will be checked for validity.
+ * See `git_tag_create()` for rules about valid names.
+ *
+ * @param branch Current underlying reference of the branch.
+ *
+ * @param new_branch_name Target name of the branch once the move
+ * is performed; this name is validated for consistency.
+ *
+ * @param force Overwrite existing branch.
+ *
+ * @return 0 on success, GIT_EINVALIDSPEC or an error code.
+ */
+GIT_EXTERN(int) git_branch_move(
+	git_reference **out,
+	git_reference *branch,
+	const char *new_branch_name,
+	int force);
+
+/**
+ * Lookup a branch by its name in a repository.
+ *
+ * The generated reference must be freed by the user.
+ *
+ * The branch name will be checked for validity.
+ * See `git_tag_create()` for rules about valid names.
+ *
+ * @param out pointer to the looked-up branch reference
+ *
+ * @param repo the repository to look up the branch
+ *
+ * @param branch_name Name of the branch to be looked-up;
+ * this name is validated for consistency.
+ *
+ * @param branch_type Type of the considered branch. This should
+ * be valued with either GIT_BRANCH_LOCAL or GIT_BRANCH_REMOTE.
+ *
+ * @return 0 on success; GIT_ENOTFOUND when no matching branch
+ * exists, GIT_EINVALIDSPEC, otherwise an error code.
+ */
+GIT_EXTERN(int) git_branch_lookup(
+	git_reference **out,
+	git_repository *repo,
+	const char *branch_name,
+	git_branch_t branch_type);
+
+/**
+ * Return the name of the given local or remote branch.
+ *
+ * The name of the branch matches the definition of the name
+ * for git_branch_lookup. That is, if the returned name is given
+ * to git_branch_lookup() then the reference is returned that
+ * was given to this function.
+ *
+ * @param out where the pointer of branch name is stored;
+ * this is valid as long as the ref is not freed.
+ * @param ref the reference ideally pointing to a branch
+ *
+ * @return 0 on success; otherwise an error code (e.g., if the
+ *  ref is no local or remote branch).
+ */
+GIT_EXTERN(int) git_branch_name(
+		const char **out,
+		const git_reference *ref);
+
+/**
+ * Return the reference supporting the remote tracking branch,
+ * given a local branch reference.
+ *
+ * @param out Pointer where to store the retrieved
+ * reference.
+ *
+ * @param branch Current underlying reference of the branch.
+ *
+ * @return 0 on success; GIT_ENOTFOUND when no remote tracking
+ * reference exists, otherwise an error code.
+ */
+GIT_EXTERN(int) git_branch_upstream(
+	git_reference **out,
+	const git_reference *branch);
+
+/**
+ * Set the upstream configuration for a given local branch
+ *
+ * @param branch the branch to configure
+ *
+ * @param upstream_name remote-tracking or local branch to set as
+ * upstream. Pass NULL to unset.
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_branch_set_upstream(git_reference *branch, const char *upstream_name);
+
+/**
+ * Return the name of the reference supporting the remote tracking branch,
+ * given the name of a local branch reference.
+ *
+ * @param out Pointer to the user-allocated git_buf which will be
+ * filled with the name of the reference.
+ *
+ * @param repo the repository where the branches live
+ *
+ * @param refname reference name of the local branch.
+ *
+ * @return 0, GIT_ENOTFOUND when no remote tracking reference exists,
+ *     otherwise an error code.
+ */
+GIT_EXTERN(int) git_branch_upstream_name(
+	git_buf *out,
+	git_repository *repo,
+	const char *refname);
+
+/**
+ * Determine if the current local branch is pointed at by HEAD.
+ *
+ * @param branch Current underlying reference of the branch.
+ *
+ * @return 1 if HEAD points at the branch, 0 if it isn't,
+ * error code otherwise.
+ */
+GIT_EXTERN(int) git_branch_is_head(
+	const git_reference *branch);
+
+/**
+ * Determine if the current branch is checked out in any linked
+ * repository.
+ *
+ * @param branch Reference to the branch.
+ *
+ * @return 1 if branch is checked out, 0 if it isn't,
+ * error code otherwise.
+ */
+GIT_EXTERN(int) git_branch_is_checked_out(
+	const git_reference *branch);
+
+/**
+ * Return the name of remote that the remote tracking branch belongs to.
+ *
+ * @param out Pointer to the user-allocated git_buf which will be filled with the name of the remote.
+ *
+ * @param repo The repository where the branch lives.
+ *
+ * @param canonical_branch_name name of the remote tracking branch.
+ *
+ * @return 0, GIT_ENOTFOUND
+ *     when no remote matching remote was found,
+ *     GIT_EAMBIGUOUS when the branch maps to several remotes,
+ *     otherwise an error code.
+ */
+GIT_EXTERN(int) git_branch_remote_name(
+	git_buf *out,
+	git_repository *repo,
+	const char *canonical_branch_name);
+
+
+/**
+ * Retrieve the name fo the upstream remote of a local branch
+ *
+ * @param buf the buffer into which to write the name
+ * @param repo the repository in which to look
+ * @param refname the full name of the branch
+ * @return 0 or an error code
+ */
+ GIT_EXTERN(int) git_branch_upstream_remote(git_buf *buf, git_repository *repo, const char *refname);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/buffer.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/buffer.h b/vendor/libgit2-sys/libgit2/include/git2/buffer.h
new file mode 100644
index 0000000..9fc6a58
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/buffer.h
@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_buf_h__
+#define INCLUDE_git_buf_h__
+
+#include "common.h"
+
+/**
+ * @file git2/buffer.h
+ * @brief Buffer export structure
+ *
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * A data buffer for exporting data from libgit2
+ *
+ * Sometimes libgit2 wants to return an allocated data buffer to the
+ * caller and have the caller take responsibility for freeing that memory.
+ * This can be awkward if the caller does not have easy access to the same
+ * allocation functions that libgit2 is using.  In those cases, libgit2
+ * will fill in a `git_buf` and the caller can use `git_buf_free()` to
+ * release it when they are done.
+ *
+ * A `git_buf` may also be used for the caller to pass in a reference to
+ * a block of memory they hold.  In this case, libgit2 will not resize or
+ * free the memory, but will read from it as needed.
+ *
+ * A `git_buf` is a public structure with three fields:
+ *
+ * - `ptr` points to the start of the allocated memory.  If it is NULL,
+ *   then the `git_buf` is considered empty and libgit2 will feel free
+ *   to overwrite it with new data.
+ *
+ * - `size` holds the size (in bytes) of the data that is actually used.
+ *
+ * - `asize` holds the known total amount of allocated memory if the `ptr`
+ *    was allocated by libgit2.  It may be larger than `size`.  If `ptr`
+ *    was not allocated by libgit2 and should not be resized and/or freed,
+ *    then `asize` will be set to zero.
+ *
+ * Some APIs may occasionally do something slightly unusual with a buffer,
+ * such as setting `ptr` to a value that was passed in by the user.  In
+ * those cases, the behavior will be clearly documented by the API.
+ */
+typedef struct {
+	char   *ptr;
+	size_t asize, size;
+} git_buf;
+
+/**
+ * Static initializer for git_buf from static buffer
+ */
+#define GIT_BUF_INIT_CONST(STR,LEN) { (char *)(STR), 0, (size_t)(LEN) }
+
+/**
+ * Free the memory referred to by the git_buf.
+ *
+ * Note that this does not free the `git_buf` itself, just the memory
+ * pointed to by `buffer->ptr`.  This will not free the memory if it looks
+ * like it was not allocated internally, but it will clear the buffer back
+ * to the empty state.
+ *
+ * @param buffer The buffer to deallocate
+ */
+GIT_EXTERN(void) git_buf_free(git_buf *buffer);
+
+/**
+ * Resize the buffer allocation to make more space.
+ *
+ * This will attempt to grow the buffer to accommodate the target size.
+ *
+ * If the buffer refers to memory that was not allocated by libgit2 (i.e.
+ * the `asize` field is zero), then `ptr` will be replaced with a newly
+ * allocated block of data.  Be careful so that memory allocated by the
+ * caller is not lost.  As a special variant, if you pass `target_size` as
+ * 0 and the memory is not allocated by libgit2, this will allocate a new
+ * buffer of size `size` and copy the external data into it.
+ *
+ * Currently, this will never shrink a buffer, only expand it.
+ *
+ * If the allocation fails, this will return an error and the buffer will be
+ * marked as invalid for future operations, invaliding the contents.
+ *
+ * @param buffer The buffer to be resized; may or may not be allocated yet
+ * @param target_size The desired available size
+ * @return 0 on success, -1 on allocation failure
+ */
+GIT_EXTERN(int) git_buf_grow(git_buf *buffer, size_t target_size);
+
+/**
+ * Set buffer to a copy of some raw data.
+ *
+ * @param buffer The buffer to set
+ * @param data The data to copy into the buffer
+ * @param datalen The length of the data to copy into the buffer
+ * @return 0 on success, -1 on allocation failure
+ */
+GIT_EXTERN(int) git_buf_set(
+	git_buf *buffer, const void *data, size_t datalen);
+
+/**
+* Check quickly if buffer looks like it contains binary data
+*
+* @param buf Buffer to check
+* @return 1 if buffer looks like non-text data
+*/
+GIT_EXTERN(int) git_buf_is_binary(const git_buf *buf);
+
+/**
+* Check quickly if buffer contains a NUL byte
+*
+* @param buf Buffer to check
+* @return 1 if buffer contains a NUL byte
+*/
+GIT_EXTERN(int) git_buf_contains_nul(const git_buf *buf);
+
+GIT_END_DECL
+
+/** @} */
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/checkout.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/checkout.h b/vendor/libgit2-sys/libgit2/include/git2/checkout.h
new file mode 100644
index 0000000..c7b0c83
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/checkout.h
@@ -0,0 +1,365 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_checkout_h__
+#define INCLUDE_git_checkout_h__
+
+#include "common.h"
+#include "types.h"
+#include "diff.h"
+
+/**
+ * @file git2/checkout.h
+ * @brief Git checkout routines
+ * @defgroup git_checkout Git checkout routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Checkout behavior flags
+ *
+ * In libgit2, checkout is used to update the working directory and index
+ * to match a target tree.  Unlike git checkout, it does not move the HEAD
+ * commit for you - use `git_repository_set_head` or the like to do that.
+ *
+ * Checkout looks at (up to) four things: the "target" tree you want to
+ * check out, the "baseline" tree of what was checked out previously, the
+ * working directory for actual files, and the index for staged changes.
+ *
+ * You give checkout one of three strategies for update:
+ *
+ * - `GIT_CHECKOUT_NONE` is a dry-run strategy that checks for conflicts,
+ *   etc., but doesn't make any actual changes.
+ *
+ * - `GIT_CHECKOUT_FORCE` is at the opposite extreme, taking any action to
+ *   make the working directory match the target (including potentially
+ *   discarding modified files).
+ *
+ * - `GIT_CHECKOUT_SAFE` is between these two options, it will only make
+ *   modifications that will not lose changes.
+ *
+ *                         |  target == baseline   |  target != baseline  |
+ *    ---------------------|-----------------------|----------------------|
+ *     workdir == baseline |       no action       |  create, update, or  |
+ *                         |                       |     delete file      |
+ *    ---------------------|-----------------------|----------------------|
+ *     workdir exists and  |       no action       |   conflict (notify   |
+ *       is != baseline    | notify dirty MODIFIED | and cancel checkout) |
+ *    ---------------------|-----------------------|----------------------|
+ *      workdir missing,   | notify dirty DELETED  |     create file      |
+ *      baseline present   |                       |                      |
+ *    ---------------------|-----------------------|----------------------|
+ *
+ * To emulate `git checkout`, use `GIT_CHECKOUT_SAFE` with a checkout
+ * notification callback (see below) that displays information about dirty
+ * files.  The default behavior will cancel checkout on conflicts.
+ *
+ * To emulate `git checkout-index`, use `GIT_CHECKOUT_SAFE` with a
+ * notification callback that cancels the operation if a dirty-but-existing
+ * file is found in the working directory.  This core git command isn't
+ * quite "force" but is sensitive about some types of changes.
+ *
+ * To emulate `git checkout -f`, use `GIT_CHECKOUT_FORCE`.
+ *
+ *
+ * There are some additional flags to modified the behavior of checkout:
+ *
+ * - GIT_CHECKOUT_ALLOW_CONFLICTS makes SAFE mode apply safe file updates
+ *   even if there are conflicts (instead of cancelling the checkout).
+ *
+ * - GIT_CHECKOUT_REMOVE_UNTRACKED means remove untracked files (i.e. not
+ *   in target, baseline, or index, and not ignored) from the working dir.
+ *
+ * - GIT_CHECKOUT_REMOVE_IGNORED means remove ignored files (that are also
+ *   untracked) from the working directory as well.
+ *
+ * - GIT_CHECKOUT_UPDATE_ONLY means to only update the content of files that
+ *   already exist.  Files will not be created nor deleted.  This just skips
+ *   applying adds, deletes, and typechanges.
+ *
+ * - GIT_CHECKOUT_DONT_UPDATE_INDEX prevents checkout from writing the
+ *   updated files' information to the index.
+ *
+ * - Normally, checkout will reload the index and git attributes from disk
+ *   before any operations.  GIT_CHECKOUT_NO_REFRESH prevents this reload.
+ *
+ * - Unmerged index entries are conflicts.  GIT_CHECKOUT_SKIP_UNMERGED skips
+ *   files with unmerged index entries instead.  GIT_CHECKOUT_USE_OURS and
+ *   GIT_CHECKOUT_USE_THEIRS to proceed with the checkout using either the
+ *   stage 2 ("ours") or stage 3 ("theirs") version of files in the index.
+ *
+ * - GIT_CHECKOUT_DONT_OVERWRITE_IGNORED prevents ignored files from being
+ *   overwritten.  Normally, files that are ignored in the working directory
+ *   are not considered "precious" and may be overwritten if the checkout
+ *   target contains that file.
+ *
+ * - GIT_CHECKOUT_DONT_REMOVE_EXISTING prevents checkout from removing
+ *   files or folders that fold to the same name on case insensitive
+ *   filesystems.  This can cause files to retain their existing names
+ *   and write through existing symbolic links.
+ */
+typedef enum {
+	GIT_CHECKOUT_NONE = 0, /**< default is a dry run, no actual updates */
+
+	/** Allow safe updates that cannot overwrite uncommitted data */
+	GIT_CHECKOUT_SAFE = (1u << 0),
+
+	/** Allow all updates to force working directory to look like index */
+	GIT_CHECKOUT_FORCE = (1u << 1),
+
+
+	/** Allow checkout to recreate missing files */
+	GIT_CHECKOUT_RECREATE_MISSING = (1u << 2),
+
+	/** Allow checkout to make safe updates even if conflicts are found */
+	GIT_CHECKOUT_ALLOW_CONFLICTS = (1u << 4),
+
+	/** Remove untracked files not in index (that are not ignored) */
+	GIT_CHECKOUT_REMOVE_UNTRACKED = (1u << 5),
+
+	/** Remove ignored files not in index */
+	GIT_CHECKOUT_REMOVE_IGNORED = (1u << 6),
+
+	/** Only update existing files, don't create new ones */
+	GIT_CHECKOUT_UPDATE_ONLY = (1u << 7),
+
+	/**
+	 * Normally checkout updates index entries as it goes; this stops that.
+	 * Implies `GIT_CHECKOUT_DONT_WRITE_INDEX`.
+	 */
+	GIT_CHECKOUT_DONT_UPDATE_INDEX = (1u << 8),
+
+	/** Don't refresh index/config/etc before doing checkout */
+	GIT_CHECKOUT_NO_REFRESH = (1u << 9),
+
+	/** Allow checkout to skip unmerged files */
+	GIT_CHECKOUT_SKIP_UNMERGED = (1u << 10),
+	/** For unmerged files, checkout stage 2 from index */
+	GIT_CHECKOUT_USE_OURS = (1u << 11),
+	/** For unmerged files, checkout stage 3 from index */
+	GIT_CHECKOUT_USE_THEIRS = (1u << 12),
+
+	/** Treat pathspec as simple list of exact match file paths */
+	GIT_CHECKOUT_DISABLE_PATHSPEC_MATCH = (1u << 13),
+
+	/** Ignore directories in use, they will be left empty */
+	GIT_CHECKOUT_SKIP_LOCKED_DIRECTORIES = (1u << 18),
+
+	/** Don't overwrite ignored files that exist in the checkout target */
+	GIT_CHECKOUT_DONT_OVERWRITE_IGNORED = (1u << 19),
+
+	/** Write normal merge files for conflicts */
+	GIT_CHECKOUT_CONFLICT_STYLE_MERGE = (1u << 20),
+
+	/** Include common ancestor data in diff3 format files for conflicts */
+	GIT_CHECKOUT_CONFLICT_STYLE_DIFF3 = (1u << 21),
+
+	/** Don't overwrite existing files or folders */
+	GIT_CHECKOUT_DONT_REMOVE_EXISTING = (1u << 22),
+
+	/** Normally checkout writes the index upon completion; this prevents that. */
+	GIT_CHECKOUT_DONT_WRITE_INDEX = (1u << 23),
+
+	/**
+	 * THE FOLLOWING OPTIONS ARE NOT YET IMPLEMENTED
+	 */
+
+	/** Recursively checkout submodules with same options (NOT IMPLEMENTED) */
+	GIT_CHECKOUT_UPDATE_SUBMODULES = (1u << 16),
+	/** Recursively checkout submodules if HEAD moved in super repo (NOT IMPLEMENTED) */
+	GIT_CHECKOUT_UPDATE_SUBMODULES_IF_CHANGED = (1u << 17),
+
+} git_checkout_strategy_t;
+
+/**
+ * Checkout notification flags
+ *
+ * Checkout will invoke an options notification callback (`notify_cb`) for
+ * certain cases - you pick which ones via `notify_flags`:
+ *
+ * - GIT_CHECKOUT_NOTIFY_CONFLICT invokes checkout on conflicting paths.
+ *
+ * - GIT_CHECKOUT_NOTIFY_DIRTY notifies about "dirty" files, i.e. those that
+ *   do not need an update but no longer match the baseline.  Core git
+ *   displays these files when checkout runs, but won't stop the checkout.
+ *
+ * - GIT_CHECKOUT_NOTIFY_UPDATED sends notification for any file changed.
+ *
+ * - GIT_CHECKOUT_NOTIFY_UNTRACKED notifies about untracked files.
+ *
+ * - GIT_CHECKOUT_NOTIFY_IGNORED notifies about ignored files.
+ *
+ * Returning a non-zero value from this callback will cancel the checkout.
+ * The non-zero return value will be propagated back and returned by the
+ * git_checkout_... call.
+ *
+ * Notification callbacks are made prior to modifying any files on disk,
+ * so canceling on any notification will still happen prior to any files
+ * being modified.
+ */
+typedef enum {
+	GIT_CHECKOUT_NOTIFY_NONE      = 0,
+	GIT_CHECKOUT_NOTIFY_CONFLICT  = (1u << 0),
+	GIT_CHECKOUT_NOTIFY_DIRTY     = (1u << 1),
+	GIT_CHECKOUT_NOTIFY_UPDATED   = (1u << 2),
+	GIT_CHECKOUT_NOTIFY_UNTRACKED = (1u << 3),
+	GIT_CHECKOUT_NOTIFY_IGNORED   = (1u << 4),
+
+	GIT_CHECKOUT_NOTIFY_ALL       = 0x0FFFFu
+} git_checkout_notify_t;
+
+typedef struct {
+	size_t mkdir_calls;
+	size_t stat_calls;
+	size_t chmod_calls;
+} git_checkout_perfdata;
+
+/** Checkout notification callback function */
+typedef int (*git_checkout_notify_cb)(
+	git_checkout_notify_t why,
+	const char *path,
+	const git_diff_file *baseline,
+	const git_diff_file *target,
+	const git_diff_file *workdir,
+	void *payload);
+
+/** Checkout progress notification function */
+typedef void (*git_checkout_progress_cb)(
+	const char *path,
+	size_t completed_steps,
+	size_t total_steps,
+	void *payload);
+
+/** Checkout perfdata notification function */
+typedef void (*git_checkout_perfdata_cb)(
+	const git_checkout_perfdata *perfdata,
+	void *payload);
+
+/**
+ * Checkout options structure
+ *
+ * Zero out for defaults.  Initialize with `GIT_CHECKOUT_OPTIONS_INIT` macro to
+ * correctly set the `version` field.  E.g.
+ *
+ *		git_checkout_options opts = GIT_CHECKOUT_OPTIONS_INIT;
+ */
+typedef struct git_checkout_options {
+	unsigned int version;
+
+	unsigned int checkout_strategy; /**< default will be a safe checkout */
+
+	int disable_filters;    /**< don't apply filters like CRLF conversion */
+	unsigned int dir_mode;  /**< default is 0755 */
+	unsigned int file_mode; /**< default is 0644 or 0755 as dictated by blob */
+	int file_open_flags;    /**< default is O_CREAT | O_TRUNC | O_WRONLY */
+
+	unsigned int notify_flags; /**< see `git_checkout_notify_t` above */
+	git_checkout_notify_cb notify_cb;
+	void *notify_payload;
+
+	/** Optional callback to notify the consumer of checkout progress. */
+	git_checkout_progress_cb progress_cb;
+	void *progress_payload;
+
+	/** When not zeroed out, array of fnmatch patterns specifying which
+	 *  paths should be taken into account, otherwise all files.  Use
+	 *  GIT_CHECKOUT_DISABLE_PATHSPEC_MATCH to treat as simple list.
+	 */
+	git_strarray paths;
+
+	/** The expected content of the working directory; defaults to HEAD.
+	 *  If the working directory does not match this baseline information,
+	 *  that will produce a checkout conflict.
+	 */
+	git_tree *baseline;
+
+	/** Like `baseline` above, though expressed as an index.  This
+	 *  option overrides `baseline`.
+	 */
+	git_index *baseline_index; /**< expected content of workdir, expressed as an index. */
+
+	const char *target_directory; /**< alternative checkout path to workdir */
+
+	const char *ancestor_label; /**< the name of the common ancestor side of conflicts */
+	const char *our_label; /**< the name of the "our" side of conflicts */
+	const char *their_label; /**< the name of the "their" side of conflicts */
+
+	/** Optional callback to notify the consumer of performance data. */
+	git_checkout_perfdata_cb perfdata_cb;
+	void *perfdata_payload;
+} git_checkout_options;
+
+#define GIT_CHECKOUT_OPTIONS_VERSION 1
+#define GIT_CHECKOUT_OPTIONS_INIT {GIT_CHECKOUT_OPTIONS_VERSION, GIT_CHECKOUT_SAFE}
+
+/**
+* Initializes a `git_checkout_options` with default values. Equivalent to
+* creating an instance with GIT_CHECKOUT_OPTIONS_INIT.
+*
+* @param opts the `git_checkout_options` struct to initialize.
+* @param version Version of struct; pass `GIT_CHECKOUT_OPTIONS_VERSION`
+* @return Zero on success; -1 on failure.
+*/
+GIT_EXTERN(int) git_checkout_init_options(
+	git_checkout_options *opts,
+	unsigned int version);
+
+/**
+ * Updates files in the index and the working tree to match the content of
+ * the commit pointed at by HEAD.
+ *
+ * Note that this is _not_ the correct mechanism used to switch branches;
+ * do not change your `HEAD` and then call this method, that would leave
+ * you with checkout conflicts since your working directory would then
+ * appear to be dirty.  Instead, checkout the target of the branch and
+ * then update `HEAD` using `git_repository_set_head` to point to the
+ * branch you checked out.
+ *
+ * @param repo repository to check out (must be non-bare)
+ * @param opts specifies checkout options (may be NULL)
+ * @return 0 on success, GIT_EUNBORNBRANCH if HEAD points to a non
+ *         existing branch, non-zero value returned by `notify_cb`, or
+ *         other error code < 0 (use giterr_last for error details)
+ */
+GIT_EXTERN(int) git_checkout_head(
+	git_repository *repo,
+	const git_checkout_options *opts);
+
+/**
+ * Updates files in the working tree to match the content of the index.
+ *
+ * @param repo repository into which to check out (must be non-bare)
+ * @param index index to be checked out (or NULL to use repository index)
+ * @param opts specifies checkout options (may be NULL)
+ * @return 0 on success, non-zero return value from `notify_cb`, or error
+ *         code < 0 (use giterr_last for error details)
+ */
+GIT_EXTERN(int) git_checkout_index(
+	git_repository *repo,
+	git_index *index,
+	const git_checkout_options *opts);
+
+/**
+ * Updates files in the index and working tree to match the content of the
+ * tree pointed at by the treeish.
+ *
+ * @param repo repository to check out (must be non-bare)
+ * @param treeish a commit, tag or tree which content will be used to update
+ * the working directory (or NULL to use HEAD)
+ * @param opts specifies checkout options (may be NULL)
+ * @return 0 on success, non-zero return value from `notify_cb`, or error
+ *         code < 0 (use giterr_last for error details)
+ */
+GIT_EXTERN(int) git_checkout_tree(
+	git_repository *repo,
+	const git_object *treeish,
+	const git_checkout_options *opts);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/cherrypick.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/cherrypick.h b/vendor/libgit2-sys/libgit2/include/git2/cherrypick.h
new file mode 100644
index 0000000..edec96a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/cherrypick.h
@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_cherrypick_h__
+#define INCLUDE_git_cherrypick_h__
+
+#include "common.h"
+#include "types.h"
+#include "merge.h"
+
+/**
+ * @file git2/cherrypick.h
+ * @brief Git cherry-pick routines
+ * @defgroup git_cherrypick Git cherry-pick routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Cherry-pick options
+ */
+typedef struct {
+	unsigned int version;
+
+	/** For merge commits, the "mainline" is treated as the parent. */
+	unsigned int mainline;
+
+	git_merge_options merge_opts; /**< Options for the merging */
+	git_checkout_options checkout_opts; /**< Options for the checkout */
+} git_cherrypick_options;
+
+#define GIT_CHERRYPICK_OPTIONS_VERSION 1
+#define GIT_CHERRYPICK_OPTIONS_INIT {GIT_CHERRYPICK_OPTIONS_VERSION, 0, GIT_MERGE_OPTIONS_INIT, GIT_CHECKOUT_OPTIONS_INIT}
+
+/**
+ * Initializes a `git_cherrypick_options` with default values. Equivalent to
+ * creating an instance with GIT_CHERRYPICK_OPTIONS_INIT.
+ *
+ * @param opts the `git_cherrypick_options` struct to initialize
+ * @param version Version of struct; pass `GIT_CHERRYPICK_OPTIONS_VERSION`
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_cherrypick_init_options(
+	git_cherrypick_options *opts,
+	unsigned int version);
+
+/**
+ * Cherry-picks the given commit against the given "our" commit, producing an
+ * index that reflects the result of the cherry-pick.
+ *
+ * The returned index must be freed explicitly with `git_index_free`.
+ *
+ * @param out pointer to store the index result in
+ * @param repo the repository that contains the given commits
+ * @param cherrypick_commit the commit to cherry-pick
+ * @param our_commit the commit to revert against (eg, HEAD)
+ * @param mainline the parent of the revert commit, if it is a merge
+ * @param merge_options the merge options (or null for defaults)
+ * @return zero on success, -1 on failure.
+ */
+GIT_EXTERN(int) git_cherrypick_commit(
+	git_index **out,
+	git_repository *repo,
+	git_commit *cherrypick_commit,
+	git_commit *our_commit,
+	unsigned int mainline,
+	const git_merge_options *merge_options);
+
+/**
+ * Cherry-pick the given commit, producing changes in the index and working directory.
+ *
+ * @param repo the repository to cherry-pick
+ * @param commit the commit to cherry-pick
+ * @param cherrypick_options the cherry-pick options (or null for defaults)
+ * @return zero on success, -1 on failure.
+ */
+GIT_EXTERN(int) git_cherrypick(
+	git_repository *repo,
+	git_commit *commit,
+	const git_cherrypick_options *cherrypick_options);
+
+/** @} */
+GIT_END_DECL
+
+#endif
+

vendor/libgit2-sys/libgit2/include/git2/clone.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/clone.h b/vendor/libgit2-sys/libgit2/include/git2/clone.h
new file mode 100644
index 0000000..9e23aac
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/clone.h
@@ -0,0 +1,207 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_clone_h__
+#define INCLUDE_git_clone_h__
+
+#include "common.h"
+#include "types.h"
+#include "indexer.h"
+#include "checkout.h"
+#include "remote.h"
+#include "transport.h"
+
+
+/**
+ * @file git2/clone.h
+ * @brief Git cloning routines
+ * @defgroup git_clone Git cloning routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Options for bypassing the git-aware transport on clone. Bypassing
+ * it means that instead of a fetch, libgit2 will copy the object
+ * database directory instead of figuring out what it needs, which is
+ * faster. If possible, it will hardlink the files to save space.
+ */
+typedef enum {
+	/**
+	 * Auto-detect (default), libgit2 will bypass the git-aware
+	 * transport for local paths, but use a normal fetch for
+	 * `file://` urls.
+	 */
+	GIT_CLONE_LOCAL_AUTO,
+	/**
+	 * Bypass the git-aware transport even for a `file://` url.
+	 */
+	GIT_CLONE_LOCAL,
+	/**
+	 * Do no bypass the git-aware transport
+	 */
+	GIT_CLONE_NO_LOCAL,
+	/**
+	 * Bypass the git-aware transport, but do not try to use
+	 * hardlinks.
+	 */
+	GIT_CLONE_LOCAL_NO_LINKS,
+} git_clone_local_t;
+
+/**
+ * The signature of a function matching git_remote_create, with an additional
+ * void* as a callback payload.
+ *
+ * Callers of git_clone may provide a function matching this signature to override
+ * the remote creation and customization process during a clone operation.
+ *
+ * @param out the resulting remote
+ * @param repo the repository in which to create the remote
+ * @param name the remote's name
+ * @param url the remote's url
+ * @param payload an opaque payload
+ * @return 0, GIT_EINVALIDSPEC, GIT_EEXISTS or an error code
+ */
+typedef int (*git_remote_create_cb)(
+	git_remote **out,
+	git_repository *repo,
+	const char *name,
+	const char *url,
+	void *payload);
+
+/**
+ * The signature of a function matchin git_repository_init, with an
+ * aditional void * as callback payload.
+ *
+ * Callers of git_clone my provide a function matching this signature
+ * to override the repository creation and customization process
+ * during a clone operation.
+ *
+ * @param out the resulting repository
+ * @param path path in which to create the repository
+ * @param bare whether the repository is bare. This is the value from the clone options
+ * @param payload payload specified by the options
+ * @return 0, or a negative value to indicate error
+ */
+typedef int (*git_repository_create_cb)(
+	git_repository **out,
+	const char *path,
+	int bare,
+	void *payload);
+
+/**
+ * Clone options structure
+ *
+ * Use the GIT_CLONE_OPTIONS_INIT to get the default settings, like this:
+ *
+ *		git_clone_options opts = GIT_CLONE_OPTIONS_INIT;
+ */
+typedef struct git_clone_options {
+	unsigned int version;
+
+	/**
+	 * These options are passed to the checkout step. To disable
+	 * checkout, set the `checkout_strategy` to
+	 * `GIT_CHECKOUT_NONE`.
+	 */
+	git_checkout_options checkout_opts;
+
+	/**
+	 * Options which control the fetch, including callbacks.
+	 *
+	 * The callbacks are used for reporting fetch progress, and for acquiring
+	 * credentials in the event they are needed.
+	 */
+	git_fetch_options fetch_opts;
+
+	/**
+	 * Set to zero (false) to create a standard repo, or non-zero
+	 * for a bare repo
+	 */
+	int bare;
+
+	/**
+	 * Whether to use a fetch or copy the object database.
+	 */
+	git_clone_local_t local;
+
+	/**
+	 * The name of the branch to checkout. NULL means use the
+	 * remote's default branch.
+	 */
+	const char* checkout_branch;
+
+	/**
+	 * A callback used to create the new repository into which to
+	 * clone. If NULL, the 'bare' field will be used to determine
+	 * whether to create a bare repository.
+	 */
+	git_repository_create_cb repository_cb;
+
+	/**
+	 * An opaque payload to pass to the git_repository creation callback.
+	 * This parameter is ignored unless repository_cb is non-NULL.
+	 */
+	void *repository_cb_payload;
+
+	/**
+	 * A callback used to create the git_remote, prior to its being
+	 * used to perform the clone operation. See the documentation for
+	 * git_remote_create_cb for details. This parameter may be NULL,
+	 * indicating that git_clone should provide default behavior.
+	 */
+	git_remote_create_cb remote_cb;
+
+	/**
+	 * An opaque payload to pass to the git_remote creation callback.
+	 * This parameter is ignored unless remote_cb is non-NULL.
+	 */
+	void *remote_cb_payload;
+} git_clone_options;
+
+#define GIT_CLONE_OPTIONS_VERSION 1
+#define GIT_CLONE_OPTIONS_INIT { GIT_CLONE_OPTIONS_VERSION, \
+	{ GIT_CHECKOUT_OPTIONS_VERSION, GIT_CHECKOUT_SAFE }, \
+	GIT_FETCH_OPTIONS_INIT }
+
+/**
+ * Initializes a `git_clone_options` with default values. Equivalent to
+ * creating an instance with GIT_CLONE_OPTIONS_INIT.
+ *
+ * @param opts The `git_clone_options` struct to initialize
+ * @param version Version of struct; pass `GIT_CLONE_OPTIONS_VERSION`
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_clone_init_options(
+	git_clone_options *opts,
+	unsigned int version);
+
+/**
+ * Clone a remote repository.
+ *
+ * By default this creates its repository and initial remote to match
+ * git's defaults. You can use the options in the callback to
+ * customize how these are created.
+ *
+ * @param out pointer that will receive the resulting repository object
+ * @param url the remote repository to clone
+ * @param local_path local directory to clone to
+ * @param options configuration options for the clone.  If NULL, the
+ *        function works as though GIT_OPTIONS_INIT were passed.
+ * @return 0 on success, any non-zero return value from a callback
+ *         function, or a negative value to indicate an error (use
+ *         `giterr_last` for a detailed error message)
+ */
+GIT_EXTERN(int) git_clone(
+	git_repository **out,
+	const char *url,
+	const char *local_path,
+	const git_clone_options *options);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/commit.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/commit.h b/vendor/libgit2-sys/libgit2/include/git2/commit.h
new file mode 100644
index 0000000..692b3bd
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/commit.h
@@ -0,0 +1,478 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_commit_h__
+#define INCLUDE_git_commit_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+#include "object.h"
+
+/**
+ * @file git2/commit.h
+ * @brief Git commit parsing, formatting routines
+ * @defgroup git_commit Git commit parsing, formatting routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Lookup a commit object from a repository.
+ *
+ * The returned object should be released with `git_commit_free` when no
+ * longer needed.
+ *
+ * @param commit pointer to the looked up commit
+ * @param repo the repo to use when locating the commit.
+ * @param id identity of the commit to locate. If the object is
+ *		an annotated tag it will be peeled back to the commit.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_commit_lookup(
+	git_commit **commit, git_repository *repo, const git_oid *id);
+
+/**
+ * Lookup a commit object from a repository, given a prefix of its
+ * identifier (short id).
+ *
+ * The returned object should be released with `git_commit_free` when no
+ * longer needed.
+ *
+ * @see git_object_lookup_prefix
+ *
+ * @param commit pointer to the looked up commit
+ * @param repo the repo to use when locating the commit.
+ * @param id identity of the commit to locate. If the object is
+ *		an annotated tag it will be peeled back to the commit.
+ * @param len the length of the short identifier
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_commit_lookup_prefix(
+	git_commit **commit, git_repository *repo, const git_oid *id, size_t len);
+
+/**
+ * Close an open commit
+ *
+ * This is a wrapper around git_object_free()
+ *
+ * IMPORTANT:
+ * It *is* necessary to call this method when you stop
+ * using a commit. Failure to do so will cause a memory leak.
+ *
+ * @param commit the commit to close
+ */
+
+GIT_EXTERN(void) git_commit_free(git_commit *commit);
+
+/**
+ * Get the id of a commit.
+ *
+ * @param commit a previously loaded commit.
+ * @return object identity for the commit.
+ */
+GIT_EXTERN(const git_oid *) git_commit_id(const git_commit *commit);
+
+/**
+ * Get the repository that contains the commit.
+ *
+ * @param commit A previously loaded commit.
+ * @return Repository that contains this commit.
+ */
+GIT_EXTERN(git_repository *) git_commit_owner(const git_commit *commit);
+
+/**
+ * Get the encoding for the message of a commit,
+ * as a string representing a standard encoding name.
+ *
+ * The encoding may be NULL if the `encoding` header
+ * in the commit is missing; in that case UTF-8 is assumed.
+ *
+ * @param commit a previously loaded commit.
+ * @return NULL, or the encoding
+ */
+GIT_EXTERN(const char *) git_commit_message_encoding(const git_commit *commit);
+
+/**
+ * Get the full message of a commit.
+ *
+ * The returned message will be slightly prettified by removing any
+ * potential leading newlines.
+ *
+ * @param commit a previously loaded commit.
+ * @return the message of a commit
+ */
+GIT_EXTERN(const char *) git_commit_message(const git_commit *commit);
+
+/**
+ * Get the full raw message of a commit.
+ *
+ * @param commit a previously loaded commit.
+ * @return the raw message of a commit
+ */
+GIT_EXTERN(const char *) git_commit_message_raw(const git_commit *commit);
+
+/**
+ * Get the short "summary" of the git commit message.
+ *
+ * The returned message is the summary of the commit, comprising the
+ * first paragraph of the message with whitespace trimmed and squashed.
+ *
+ * @param commit a previously loaded commit.
+ * @return the summary of a commit or NULL on error
+ */
+GIT_EXTERN(const char *) git_commit_summary(git_commit *commit);
+
+/**
+ * Get the long "body" of the git commit message.
+ *
+ * The returned message is the body of the commit, comprising
+ * everything but the first paragraph of the message. Leading and
+ * trailing whitespaces are trimmed.
+ *
+ * @param commit a previously loaded commit.
+ * @return the body of a commit or NULL when no the message only
+ *   consists of a summary
+ */
+GIT_EXTERN(const char *) git_commit_body(git_commit *commit);
+
+/**
+ * Get the commit time (i.e. committer time) of a commit.
+ *
+ * @param commit a previously loaded commit.
+ * @return the time of a commit
+ */
+GIT_EXTERN(git_time_t) git_commit_time(const git_commit *commit);
+
+/**
+ * Get the commit timezone offset (i.e. committer's preferred timezone) of a commit.
+ *
+ * @param commit a previously loaded commit.
+ * @return positive or negative timezone offset, in minutes from UTC
+ */
+GIT_EXTERN(int) git_commit_time_offset(const git_commit *commit);
+
+/**
+ * Get the committer of a commit.
+ *
+ * @param commit a previously loaded commit.
+ * @return the committer of a commit
+ */
+GIT_EXTERN(const git_signature *) git_commit_committer(const git_commit *commit);
+
+/**
+ * Get the author of a commit.
+ *
+ * @param commit a previously loaded commit.
+ * @return the author of a commit
+ */
+GIT_EXTERN(const git_signature *) git_commit_author(const git_commit *commit);
+
+/**
+ * Get the full raw text of the commit header.
+ *
+ * @param commit a previously loaded commit
+ * @return the header text of the commit
+ */
+GIT_EXTERN(const char *) git_commit_raw_header(const git_commit *commit);
+
+/**
+ * Get the tree pointed to by a commit.
+ *
+ * @param tree_out pointer where to store the tree object
+ * @param commit a previously loaded commit.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_commit_tree(git_tree **tree_out, const git_commit *commit);
+
+/**
+ * Get the id of the tree pointed to by a commit. This differs from
+ * `git_commit_tree` in that no attempts are made to fetch an object
+ * from the ODB.
+ *
+ * @param commit a previously loaded commit.
+ * @return the id of tree pointed to by commit.
+ */
+GIT_EXTERN(const git_oid *) git_commit_tree_id(const git_commit *commit);
+
+/**
+ * Get the number of parents of this commit
+ *
+ * @param commit a previously loaded commit.
+ * @return integer of count of parents
+ */
+GIT_EXTERN(unsigned int) git_commit_parentcount(const git_commit *commit);
+
+/**
+ * Get the specified parent of the commit.
+ *
+ * @param out Pointer where to store the parent commit
+ * @param commit a previously loaded commit.
+ * @param n the position of the parent (from 0 to `parentcount`)
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_commit_parent(
+	git_commit **out,
+	const git_commit *commit,
+	unsigned int n);
+
+/**
+ * Get the oid of a specified parent for a commit. This is different from
+ * `git_commit_parent`, which will attempt to load the parent commit from
+ * the ODB.
+ *
+ * @param commit a previously loaded commit.
+ * @param n the position of the parent (from 0 to `parentcount`)
+ * @return the id of the parent, NULL on error.
+ */
+GIT_EXTERN(const git_oid *) git_commit_parent_id(
+	const git_commit *commit,
+	unsigned int n);
+
+/**
+ * Get the commit object that is the <n>th generation ancestor
+ * of the named commit object, following only the first parents.
+ * The returned commit has to be freed by the caller.
+ *
+ * Passing `0` as the generation number returns another instance of the
+ * base commit itself.
+ *
+ * @param ancestor Pointer where to store the ancestor commit
+ * @param commit a previously loaded commit.
+ * @param n the requested generation
+ * @return 0 on success; GIT_ENOTFOUND if no matching ancestor exists
+ * or an error code
+ */
+GIT_EXTERN(int) git_commit_nth_gen_ancestor(
+	git_commit **ancestor,
+	const git_commit *commit,
+	unsigned int n);
+
+/**
+ * Get an arbitrary header field
+ *
+ * @param out the buffer to fill; existing content will be
+ * overwritten
+ * @param commit the commit to look in
+ * @param field the header field to return
+ * @return 0 on succeess, GIT_ENOTFOUND if the field does not exist,
+ * or an error code
+ */
+GIT_EXTERN(int) git_commit_header_field(git_buf *out, const git_commit *commit, const char *field);
+
+/**
+ * Extract the signature from a commit
+ *
+ * If the id is not for a commit, the error class will be
+ * `GITERR_INVALID`. If the commit does not have a signature, the
+ * error class will be `GITERR_OBJECT`.
+ *
+ * @param signature the signature block; existing content will be
+ * overwritten
+ * @param signed_data signed data; this is the commit contents minus the signature block;
+ * existing content will be overwritten
+ * @param repo the repository in which the commit exists
+ * @param commit_id the commit from which to extract the data
+ * @param field the name of the header field containing the signature
+ * block; pass `NULL` to extract the default 'gpgsig'
+ * @return 0 on success, GIT_ENOTFOUND if the id is not for a commit
+ * or the commit does not have a signature.
+ */
+GIT_EXTERN(int) git_commit_extract_signature(git_buf *signature, git_buf *signed_data, git_repository *repo, git_oid *commit_id, const char *field);
+
+/**
+ * Create new commit in the repository from a list of `git_object` pointers
+ *
+ * The message will **not** be cleaned up automatically. You can do that
+ * with the `git_message_prettify()` function.
+ *
+ * @param id Pointer in which to store the OID of the newly created commit
+ *
+ * @param repo Repository where to store the commit
+ *
+ * @param update_ref If not NULL, name of the reference that
+ *	will be updated to point to this commit. If the reference
+ *	is not direct, it will be resolved to a direct reference.
+ *	Use "HEAD" to update the HEAD of the current branch and
+ *	make it point to this commit. If the reference doesn't
+ *	exist yet, it will be created. If it does exist, the first
+ *	parent must be the tip of this branch.
+ *
+ * @param author Signature with author and author time of commit
+ *
+ * @param committer Signature with committer and * commit time of commit
+ *
+ * @param message_encoding The encoding for the message in the
+ *  commit, represented with a standard encoding name.
+ *  E.g. "UTF-8". If NULL, no encoding header is written and
+ *  UTF-8 is assumed.
+ *
+ * @param message Full message for this commit
+ *
+ * @param tree An instance of a `git_tree` object that will
+ *  be used as the tree for the commit. This tree object must
+ *  also be owned by the given `repo`.
+ *
+ * @param parent_count Number of parents for this commit
+ *
+ * @param parents Array of `parent_count` pointers to `git_commit`
+ *  objects that will be used as the parents for this commit. This
+ *  array may be NULL if `parent_count` is 0 (root commit). All the
+ *  given commits must be owned by the `repo`.
+ *
+ * @return 0 or an error code
+ *	The created commit will be written to the Object Database and
+ *	the given reference will be updated to point to it
+ */
+GIT_EXTERN(int) git_commit_create(
+	git_oid *id,
+	git_repository *repo,
+	const char *update_ref,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message,
+	const git_tree *tree,
+	size_t parent_count,
+	const git_commit *parents[]);
+
+/**
+ * Create new commit in the repository using a variable argument list.
+ *
+ * The message will **not** be cleaned up automatically. You can do that
+ * with the `git_message_prettify()` function.
+ *
+ * The parents for the commit are specified as a variable list of pointers
+ * to `const git_commit *`. Note that this is a convenience method which may
+ * not be safe to export for certain languages or compilers
+ *
+ * All other parameters remain the same as `git_commit_create()`.
+ *
+ * @see git_commit_create
+ */
+GIT_EXTERN(int) git_commit_create_v(
+	git_oid *id,
+	git_repository *repo,
+	const char *update_ref,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message,
+	const git_tree *tree,
+	size_t parent_count,
+	...);
+
+/**
+ * Amend an existing commit by replacing only non-NULL values.
+ *
+ * This creates a new commit that is exactly the same as the old commit,
+ * except that any non-NULL values will be updated.  The new commit has
+ * the same parents as the old commit.
+ *
+ * The `update_ref` value works as in the regular `git_commit_create()`,
+ * updating the ref to point to the newly rewritten commit.  If you want
+ * to amend a commit that is not currently the tip of the branch and then
+ * rewrite the following commits to reach a ref, pass this as NULL and
+ * update the rest of the commit chain and ref separately.
+ *
+ * Unlike `git_commit_create()`, the `author`, `committer`, `message`,
+ * `message_encoding`, and `tree` parameters can be NULL in which case this
+ * will use the values from the original `commit_to_amend`.
+ *
+ * All parameters have the same meanings as in `git_commit_create()`.
+ *
+ * @see git_commit_create
+ */
+GIT_EXTERN(int) git_commit_amend(
+	git_oid *id,
+	const git_commit *commit_to_amend,
+	const char *update_ref,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message,
+	const git_tree *tree);
+
+/**
+ * Create a commit and write it into a buffer
+ *
+ * Create a commit as with `git_commit_create()` but instead of
+ * writing it to the objectdb, write the contents of the object into a
+ * buffer.
+ *
+ * @param out the buffer into which to write the commit object content
+ *
+ * @param repo Repository where the referenced tree and parents live
+ *
+ * @param author Signature with author and author time of commit
+ *
+ * @param committer Signature with committer and * commit time of commit
+ *
+ * @param message_encoding The encoding for the message in the
+ *  commit, represented with a standard encoding name.
+ *  E.g. "UTF-8". If NULL, no encoding header is written and
+ *  UTF-8 is assumed.
+ *
+ * @param message Full message for this commit
+ *
+ * @param tree An instance of a `git_tree` object that will
+ *  be used as the tree for the commit. This tree object must
+ *  also be owned by the given `repo`.
+ *
+ * @param parent_count Number of parents for this commit
+ *
+ * @param parents Array of `parent_count` pointers to `git_commit`
+ *  objects that will be used as the parents for this commit. This
+ *  array may be NULL if `parent_count` is 0 (root commit). All the
+ *  given commits must be owned by the `repo`.
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_commit_create_buffer(
+	git_buf *out,
+	git_repository *repo,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message,
+	const git_tree *tree,
+	size_t parent_count,
+	const git_commit *parents[]);
+
+/**
+ * Create a commit object from the given buffer and signature
+ *
+ * Given the unsigned commit object's contents, its signature and the
+ * header field in which to store the signature, attach the signature
+ * to the commit and write it into the given repository.
+ *
+ * @param out the resulting commit id
+ * @param commit_content the content of the unsigned commit object
+ * @param signature the signature to add to the commit
+ * @param signature_field which header field should contain this
+ * signature. Leave `NULL` for the default of "gpgsig"
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_commit_create_with_signature(
+	git_oid *out,
+	git_repository *repo,
+	const char *commit_content,
+	const char *signature,
+	const char *signature_field);
+
+/**
+ * Create an in-memory copy of a commit. The copy must be explicitly
+ * free'd or it will leak.
+ *
+ * @param out Pointer to store the copy of the commit
+ * @param source Original commit to copy
+ */
+GIT_EXTERN(int) git_commit_dup(git_commit **out, git_commit *source);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/common.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/common.h b/vendor/libgit2-sys/libgit2/include/git2/common.h
new file mode 100644
index 0000000..f65cfdd
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/common.h
@@ -0,0 +1,357 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_common_h__
+#define INCLUDE_git_common_h__
+
+#include <time.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+# define GIT_BEGIN_DECL extern "C" {
+# define GIT_END_DECL	}
+#else
+ /** Start declarations in C mode */
+# define GIT_BEGIN_DECL /* empty */
+ /** End declarations in C mode */
+# define GIT_END_DECL	/* empty */
+#endif
+
+#if defined(_MSC_VER) && _MSC_VER < 1800
+ GIT_BEGIN_DECL
+# include "inttypes.h"
+ GIT_END_DECL
+/** This check is needed for importing this file in an iOS/OS X framework throws an error in Xcode otherwise.*/
+#elif !defined(__CLANG_INTTYPES_H)
+# include <inttypes.h>
+#endif
+
+#ifdef DOCURIUM
+/*
+ * This is so clang's doc parser acknowledges comments on functions
+ * with size_t parameters.
+ */
+typedef size_t size_t;
+#endif
+
+/** Declare a public function exported for application use. */
+#if __GNUC__ >= 4
+# define GIT_EXTERN(type) extern \
+			 __attribute__((visibility("default"))) \
+			 type
+#elif defined(_MSC_VER)
+# define GIT_EXTERN(type) __declspec(dllexport) type
+#else
+# define GIT_EXTERN(type) extern type
+#endif
+
+/** Declare a function's takes printf style arguments. */
+#ifdef __GNUC__
+# define GIT_FORMAT_PRINTF(a,b) __attribute__((format (printf, a, b)))
+#else
+# define GIT_FORMAT_PRINTF(a,b) /* empty */
+#endif
+
+#if (defined(_WIN32)) && !defined(__CYGWIN__)
+#define GIT_WIN32 1
+#endif
+
+#ifdef __amigaos4__
+#include <netinet/in.h>
+#endif
+
+/**
+ * @file git2/common.h
+ * @brief Git common platform definitions
+ * @defgroup git_common Git common platform definitions
+ * @ingroup Git
+ * @{
+ */
+
+GIT_BEGIN_DECL
+
+/**
+ * The separator used in path list strings (ie like in the PATH
+ * environment variable). A semi-colon ";" is used on Windows, and
+ * a colon ":" for all other systems.
+ */
+#ifdef GIT_WIN32
+#define GIT_PATH_LIST_SEPARATOR ';'
+#else
+#define GIT_PATH_LIST_SEPARATOR ':'
+#endif
+
+/**
+ * The maximum length of a valid git path.
+ */
+#define GIT_PATH_MAX 4096
+
+/**
+ * The string representation of the null object ID.
+ */
+#define GIT_OID_HEX_ZERO "0000000000000000000000000000000000000000"
+
+/**
+ * Return the version of the libgit2 library
+ * being currently used.
+ *
+ * @param major Store the major version number
+ * @param minor Store the minor version number
+ * @param rev Store the revision (patch) number
+ */
+GIT_EXTERN(void) git_libgit2_version(int *major, int *minor, int *rev);
+
+/**
+ * Combinations of these values describe the features with which libgit2
+ * was compiled
+ */
+typedef enum {
+  /**
+   * If set, libgit2 was built thread-aware and can be safely used from multiple
+   * threads.
+   */
+	GIT_FEATURE_THREADS	= (1 << 0),
+  /**
+   * If set, libgit2 was built with and linked against a TLS implementation.
+   * Custom TLS streams may still be added by the user to support HTTPS
+   * regardless of this.
+   */
+	GIT_FEATURE_HTTPS	= (1 << 1),
+  /**
+   * If set, libgit2 was built with and linked against libssh2. A custom
+   * transport may still be added by the user to support libssh2 regardless of
+   * this.
+   */
+	GIT_FEATURE_SSH		= (1 << 2),
+  /**
+   * If set, libgit2 was built with support for sub-second resolution in file
+   * modification times.
+   */
+	GIT_FEATURE_NSEC	= (1 << 3),
+} git_feature_t;
+
+/**
+ * Query compile time options for libgit2.
+ *
+ * @return A combination of GIT_FEATURE_* values.
+ *
+ * - GIT_FEATURE_THREADS
+ *   Libgit2 was compiled with thread support. Note that thread support is
+ *   still to be seen as a 'work in progress' - basic object lookups are
+ *   believed to be threadsafe, but other operations may not be.
+ *
+ * - GIT_FEATURE_HTTPS
+ *   Libgit2 supports the https:// protocol. This requires the openssl
+ *   library to be found when compiling libgit2.
+ *
+ * - GIT_FEATURE_SSH
+ *   Libgit2 supports the SSH protocol for network operations. This requires
+ *   the libssh2 library to be found when compiling libgit2
+ */
+GIT_EXTERN(int) git_libgit2_features(void);
+
+/**
+ * Global library options
+ *
+ * These are used to select which global option to set or get and are
+ * used in `git_libgit2_opts()`.
+ */
+typedef enum {
+	GIT_OPT_GET_MWINDOW_SIZE,
+	GIT_OPT_SET_MWINDOW_SIZE,
+	GIT_OPT_GET_MWINDOW_MAPPED_LIMIT,
+	GIT_OPT_SET_MWINDOW_MAPPED_LIMIT,
+	GIT_OPT_GET_SEARCH_PATH,
+	GIT_OPT_SET_SEARCH_PATH,
+	GIT_OPT_SET_CACHE_OBJECT_LIMIT,
+	GIT_OPT_SET_CACHE_MAX_SIZE,
+	GIT_OPT_ENABLE_CACHING,
+	GIT_OPT_GET_CACHED_MEMORY,
+	GIT_OPT_GET_TEMPLATE_PATH,
+	GIT_OPT_SET_TEMPLATE_PATH,
+	GIT_OPT_SET_SSL_CERT_LOCATIONS,
+	GIT_OPT_SET_USER_AGENT,
+	GIT_OPT_ENABLE_STRICT_OBJECT_CREATION,
+	GIT_OPT_ENABLE_STRICT_SYMBOLIC_REF_CREATION,
+	GIT_OPT_SET_SSL_CIPHERS,
+	GIT_OPT_GET_USER_AGENT,
+	GIT_OPT_ENABLE_OFS_DELTA,
+	GIT_OPT_ENABLE_FSYNC_GITDIR,
+	GIT_OPT_GET_WINDOWS_SHAREMODE,
+	GIT_OPT_SET_WINDOWS_SHAREMODE,
+	GIT_OPT_ENABLE_STRICT_HASH_VERIFICATION,
+} git_libgit2_opt_t;
+
+/**
+ * Set or query a library global option
+ *
+ * Available options:
+ *
+ *	* opts(GIT_OPT_GET_MWINDOW_SIZE, size_t *):
+ *
+ *		> Get the maximum mmap window size
+ *
+ *	* opts(GIT_OPT_SET_MWINDOW_SIZE, size_t):
+ *
+ *		> Set the maximum mmap window size
+ *
+ *	* opts(GIT_OPT_GET_MWINDOW_MAPPED_LIMIT, size_t *):
+ *
+ *		> Get the maximum memory that will be mapped in total by the library
+ *
+ *	* opts(GIT_OPT_SET_MWINDOW_MAPPED_LIMIT, size_t):
+ *
+ *		>Set the maximum amount of memory that can be mapped at any time
+ *		by the library
+ *
+ *	* opts(GIT_OPT_GET_SEARCH_PATH, int level, git_buf *buf)
+ *
+ *		> Get the search path for a given level of config data.  "level" must
+ *		> be one of `GIT_CONFIG_LEVEL_SYSTEM`, `GIT_CONFIG_LEVEL_GLOBAL`,
+ *		> `GIT_CONFIG_LEVEL_XDG`, or `GIT_CONFIG_LEVEL_PROGRAMDATA`.
+ *		> The search path is written to the `out` buffer.
+ *
+ *	* opts(GIT_OPT_SET_SEARCH_PATH, int level, const char *path)
+ *
+ *		> Set the search path for a level of config data.  The search path
+ *		> applied to shared attributes and ignore files, too.
+ *		>
+ *		> - `path` lists directories delimited by GIT_PATH_LIST_SEPARATOR.
+ *		>   Pass NULL to reset to the default (generally based on environment
+ *		>   variables).  Use magic path `$PATH` to include the old value
+ *		>   of the path (if you want to prepend or append, for instance).
+ *		>
+ *		> - `level` must be `GIT_CONFIG_LEVEL_SYSTEM`,
+ *		>   `GIT_CONFIG_LEVEL_GLOBAL`, `GIT_CONFIG_LEVEL_XDG`, or
+ *		>   `GIT_CONFIG_LEVEL_PROGRAMDATA`.
+ *
+ *	* opts(GIT_OPT_SET_CACHE_OBJECT_LIMIT, git_otype type, size_t size)
+ *
+ *		> Set the maximum data size for the given type of object to be
+ *		> considered eligible for caching in memory.  Setting to value to
+ *		> zero means that that type of object will not be cached.
+ *		> Defaults to 0 for GIT_OBJ_BLOB (i.e. won't cache blobs) and 4k
+ *		> for GIT_OBJ_COMMIT, GIT_OBJ_TREE, and GIT_OBJ_TAG.
+ *
+ *	* opts(GIT_OPT_SET_CACHE_MAX_SIZE, ssize_t max_storage_bytes)
+ *
+ *		> Set the maximum total data size that will be cached in memory
+ *		> across all repositories before libgit2 starts evicting objects
+ *		> from the cache.  This is a soft limit, in that the library might
+ *		> briefly exceed it, but will start aggressively evicting objects
+ *		> from cache when that happens.  The default cache size is 256MB.
+ *
+ *	* opts(GIT_OPT_ENABLE_CACHING, int enabled)
+ *
+ *		> Enable or disable caching completely.
+ *		>
+ *		> Because caches are repository-specific, disabling the cache
+ *		> cannot immediately clear all cached objects, but each cache will
+ *		> be cleared on the next attempt to update anything in it.
+ *
+ *	* opts(GIT_OPT_GET_CACHED_MEMORY, ssize_t *current, ssize_t *allowed)
+ *
+ *		> Get the current bytes in cache and the maximum that would be
+ *		> allowed in the cache.
+ *
+ *	* opts(GIT_OPT_GET_TEMPLATE_PATH, git_buf *out)
+ *
+ *		> Get the default template path.
+ *		> The path is written to the `out` buffer.
+ *
+ *	* opts(GIT_OPT_SET_TEMPLATE_PATH, const char *path)
+ *
+ *		> Set the default template path.
+ *		>
+ *		> - `path` directory of template.
+ *
+ *	* opts(GIT_OPT_SET_SSL_CERT_LOCATIONS, const char *file, const char *path)
+ *
+ *		> Set the SSL certificate-authority locations.
+ *		>
+ *		> - `file` is the location of a file containing several
+ *		>   certificates concatenated together.
+ *		> - `path` is the location of a directory holding several
+ *		>   certificates, one per file.
+ *		>
+ * 		> Either parameter may be `NULL`, but not both.
+ *
+ *	* opts(GIT_OPT_SET_USER_AGENT, const char *user_agent)
+ *
+ *		> Set the value of the User-Agent header.  This value will be
+ *		> appended to "git/1.0", for compatibility with other git clients.
+ *		>
+ *		> - `user_agent` is the value that will be delivered as the
+ *		>   User-Agent header on HTTP requests.
+ *
+ *	* opts(GIT_OPT_SET_WINDOWS_SHAREMODE, unsigned long value)
+ *
+ *		> Set the share mode used when opening files on Windows.
+ *		> For more information, see the documentation for CreateFile.
+ *		> The default is: FILE_SHARE_READ | FILE_SHARE_WRITE.  This is
+ *		> ignored and unused on non-Windows platforms.
+ *
+ *	* opts(GIT_OPT_GET_WINDOWS_SHAREMODE, unsigned long *value)
+ *
+ *		> Get the share mode used when opening files on Windows.
+ *
+ *	* opts(GIT_OPT_ENABLE_STRICT_OBJECT_CREATION, int enabled)
+ *
+ *		> Enable strict input validation when creating new objects
+ *		> to ensure that all inputs to the new objects are valid.  For
+ *		> example, when this is enabled, the parent(s) and tree inputs
+ *		> will be validated when creating a new commit.  This defaults
+ *		> to enabled.
+ *
+ *	* opts(GIT_OPT_ENABLE_STRICT_SYMBOLIC_REF_CREATION, int enabled)
+ *
+ *		> Validate the target of a symbolic ref when creating it.  For
+ *		> example, `foobar` is not a valid ref, therefore `foobar` is
+ *		> not a valid target for a symbolic ref by default, whereas
+ *		> `refs/heads/foobar` is.  Disabling this bypasses validation
+ *		> so that an arbitrary strings such as `foobar` can be used
+ *		> for a symbolic ref target.  This defaults to enabled.
+ *
+ *	* opts(GIT_OPT_SET_SSL_CIPHERS, const char *ciphers)
+ *
+ *		> Set the SSL ciphers use for HTTPS connections.
+ *		>
+ *		> - `ciphers` is the list of ciphers that are eanbled.
+ *
+ *	* opts(GIT_OPT_ENABLE_OFS_DELTA, int enabled)
+ *
+ *		> Enable or disable the use of "offset deltas" when creating packfiles,
+ *		> and the negotiation of them when talking to a remote server.
+ *		> Offset deltas store a delta base location as an offset into the
+ *		> packfile from the current location, which provides a shorter encoding
+ *		> and thus smaller resultant packfiles.
+ *		> Packfiles containing offset deltas can still be read.
+ *		> This defaults to enabled.
+ *
+ *	* opts(GIT_OPT_ENABLE_FSYNC_GITDIR, int enabled)
+ *
+ *		> Enable synchronized writes of files in the gitdir using `fsync`
+ *		> (or the platform equivalent) to ensure that new object data
+ *		> is written to permanent storage, not simply cached.  This
+ *		> defaults to disabled.
+ *
+ *	 opts(GIT_OPT_ENABLE_STRICT_HASH_VERIFICATION, int enabled)
+ *
+ *		> Enable strict verification of object hashsums when reading
+ *		> objects from disk. This may impact performance due to an
+ *		> additional checksum calculation on each object. This defaults
+ *		> to enabled.
+ *
+ * @param option Option key
+ * @param ... value to set the option
+ * @return 0 on success, <0 on failure
+ */
+GIT_EXTERN(int) git_libgit2_opts(int option, ...);
+
+/** @} */
+GIT_END_DECL
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/config.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/config.h b/vendor/libgit2-sys/libgit2/include/git2/config.h
new file mode 100644
index 0000000..7bcca7d
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/config.h
@@ -0,0 +1,756 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_config_h__
+#define INCLUDE_git_config_h__
+
+#include "common.h"
+#include "types.h"
+#include "buffer.h"
+
+/**
+ * @file git2/config.h
+ * @brief Git config management routines
+ * @defgroup git_config Git config management routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Priority level of a config file.
+ * These priority levels correspond to the natural escalation logic
+ * (from higher to lower) when searching for config entries in git.git.
+ *
+ * git_config_open_default() and git_repository_config() honor those
+ * priority levels as well.
+ */
+typedef enum {
+	/** System-wide on Windows, for compatibility with portable git */
+	GIT_CONFIG_LEVEL_PROGRAMDATA = 1,
+
+	/** System-wide configuration file; /etc/gitconfig on Linux systems */
+	GIT_CONFIG_LEVEL_SYSTEM = 2,
+
+	/** XDG compatible configuration file; typically ~/.config/git/config */
+	GIT_CONFIG_LEVEL_XDG = 3,
+
+	/** User-specific configuration file (also called Global configuration
+	 * file); typically ~/.gitconfig
+	 */
+	GIT_CONFIG_LEVEL_GLOBAL = 4,
+
+	/** Repository specific configuration file; $WORK_DIR/.git/config on
+	 * non-bare repos
+	 */
+	GIT_CONFIG_LEVEL_LOCAL = 5,
+
+	/** Application specific configuration file; freely defined by applications
+	 */
+	GIT_CONFIG_LEVEL_APP = 6,
+
+	/** Represents the highest level available config file (i.e. the most
+	 * specific config file available that actually is loaded)
+	 */
+	GIT_CONFIG_HIGHEST_LEVEL = -1,
+} git_config_level_t;
+
+/**
+ * An entry in a configuration file
+ */
+typedef struct git_config_entry {
+	const char *name; /**< Name of the entry (normalised) */
+	const char *value; /**< String value of the entry */
+	unsigned int include_depth; /**< Depth of includes where this variable was found */
+	git_config_level_t level; /**< Which config file this was found in */
+	void (*free)(struct git_config_entry *entry); /**< Free function for this entry */
+	void *payload; /**< Opaque value for the free function. Do not read or write */
+} git_config_entry;
+
+/**
+ * Free a config entry
+ */
+GIT_EXTERN(void) git_config_entry_free(git_config_entry *);
+
+typedef int  (*git_config_foreach_cb)(const git_config_entry *, void *);
+typedef struct git_config_iterator git_config_iterator;
+
+/**
+ * Config var type
+ */
+typedef enum {
+	GIT_CVAR_FALSE = 0,
+	GIT_CVAR_TRUE = 1,
+	GIT_CVAR_INT32,
+	GIT_CVAR_STRING
+} git_cvar_t;
+
+/**
+ * Mapping from config variables to values.
+ */
+typedef struct {
+	git_cvar_t cvar_type;
+	const char *str_match;
+	int map_value;
+} git_cvar_map;
+
+/**
+ * Locate the path to the global configuration file
+ *
+ * The user or global configuration file is usually
+ * located in `$HOME/.gitconfig`.
+ *
+ * This method will try to guess the full path to that
+ * file, if the file exists. The returned path
+ * may be used on any `git_config` call to load the
+ * global configuration file.
+ *
+ * This method will not guess the path to the xdg compatible
+ * config file (.config/git/config).
+ *
+ * @param out Pointer to a user-allocated git_buf in which to store the path
+ * @return 0 if a global configuration file has been found. Its path will be stored in `out`.
+ */
+GIT_EXTERN(int) git_config_find_global(git_buf *out);
+
+/**
+ * Locate the path to the global xdg compatible configuration file
+ *
+ * The xdg compatible configuration file is usually
+ * located in `$HOME/.config/git/config`.
+ *
+ * This method will try to guess the full path to that
+ * file, if the file exists. The returned path
+ * may be used on any `git_config` call to load the
+ * xdg compatible configuration file.
+ *
+ * @param out Pointer to a user-allocated git_buf in which to store the path
+ * @return 0 if a xdg compatible configuration file has been
+ *	found. Its path will be stored in `out`.
+ */
+GIT_EXTERN(int) git_config_find_xdg(git_buf *out);
+
+/**
+ * Locate the path to the system configuration file
+ *
+ * If /etc/gitconfig doesn't exist, it will look for
+ * %PROGRAMFILES%\Git\etc\gitconfig.
+ *
+ * @param out Pointer to a user-allocated git_buf in which to store the path
+ * @return 0 if a system configuration file has been
+ *	found. Its path will be stored in `out`.
+ */
+GIT_EXTERN(int) git_config_find_system(git_buf *out);
+
+/**
+ * Locate the path to the configuration file in ProgramData
+ *
+ * Look for the file in %PROGRAMDATA%\Git\config used by portable git.
+ *
+ * @param out Pointer to a user-allocated git_buf in which to store the path
+ * @return 0 if a ProgramData configuration file has been
+ *	found. Its path will be stored in `out`.
+ */
+GIT_EXTERN(int) git_config_find_programdata(git_buf *out);
+
+/**
+ * Open the global, XDG and system configuration files
+ *
+ * Utility wrapper that finds the global, XDG and system configuration files
+ * and opens them into a single prioritized config object that can be
+ * used when accessing default config data outside a repository.
+ *
+ * @param out Pointer to store the config instance
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_config_open_default(git_config **out);
+
+/**
+ * Allocate a new configuration object
+ *
+ * This object is empty, so you have to add a file to it before you
+ * can do anything with it.
+ *
+ * @param out pointer to the new configuration
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_config_new(git_config **out);
+
+/**
+ * Add an on-disk config file instance to an existing config
+ *
+ * The on-disk file pointed at by `path` will be opened and
+ * parsed; it's expected to be a native Git config file following
+ * the default Git config syntax (see man git-config).
+ *
+ * If the file does not exist, the file will still be added and it
+ * will be created the first time we write to it.
+ *
+ * Note that the configuration object will free the file
+ * automatically.
+ *
+ * Further queries on this config object will access each
+ * of the config file instances in order (instances with
+ * a higher priority level will be accessed first).
+ *
+ * @param cfg the configuration to add the file to
+ * @param path path to the configuration file to add
+ * @param level the priority level of the backend
+ * @param force replace config file at the given priority level
+ * @param repo optional repository to allow parsing of
+ *  conditional includes
+ * @return 0 on success, GIT_EEXISTS when adding more than one file
+ *  for a given priority level (and force_replace set to 0),
+ *  GIT_ENOTFOUND when the file doesn't exist or error code
+ */
+GIT_EXTERN(int) git_config_add_file_ondisk(
+	git_config *cfg,
+	const char *path,
+	git_config_level_t level,
+	const git_repository *repo,
+	int force);
+
+/**
+ * Create a new config instance containing a single on-disk file
+ *
+ * This method is a simple utility wrapper for the following sequence
+ * of calls:
+ *	- git_config_new
+ *	- git_config_add_file_ondisk
+ *
+ * @param out The configuration instance to create
+ * @param path Path to the on-disk file to open
+ * @return 0 on success, or an error code
+ */
+GIT_EXTERN(int) git_config_open_ondisk(git_config **out, const char *path);
+
+/**
+ * Build a single-level focused config object from a multi-level one.
+ *
+ * The returned config object can be used to perform get/set/delete operations
+ * on a single specific level.
+ *
+ * Getting several times the same level from the same parent multi-level config
+ * will return different config instances, but containing the same config_file
+ * instance.
+ *
+ * @param out The configuration instance to create
+ * @param parent Multi-level config to search for the given level
+ * @param level Configuration level to search for
+ * @return 0, GIT_ENOTFOUND if the passed level cannot be found in the
+ * multi-level parent config, or an error code
+ */
+GIT_EXTERN(int) git_config_open_level(
+	git_config **out,
+	const git_config *parent,
+	git_config_level_t level);
+
+/**
+ * Open the global/XDG configuration file according to git's rules
+ *
+ * Git allows you to store your global configuration at
+ * `$HOME/.config` or `$XDG_CONFIG_HOME/git/config`. For backwards
+ * compatability, the XDG file shouldn't be used unless the use has
+ * created it explicitly. With this function you'll open the correct
+ * one to write to.
+ *
+ * @param out pointer in which to store the config object
+ * @param config the config object in which to look
+ */
+GIT_EXTERN(int) git_config_open_global(git_config **out, git_config *config);
+
+/**
+ * Create a snapshot of the configuration
+ *
+ * Create a snapshot of the current state of a configuration, which
+ * allows you to look into a consistent view of the configuration for
+ * looking up complex values (e.g. a remote, submodule).
+ *
+ * The string returned when querying such a config object is valid
+ * until it is freed.
+ *
+ * @param out pointer in which to store the snapshot config object
+ * @param config configuration to snapshot
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_config_snapshot(git_config **out, git_config *config);
+
+/**
+ * Free the configuration and its associated memory and files
+ *
+ * @param cfg the configuration to free
+ */
+GIT_EXTERN(void) git_config_free(git_config *cfg);
+
+/**
+ * Get the git_config_entry of a config variable.
+ *
+ * Free the git_config_entry after use with `git_config_entry_free()`.
+ *
+ * @param out pointer to the variable git_config_entry
+ * @param cfg where to look for the variable
+ * @param name the variable's name
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_config_get_entry(
+	git_config_entry **out,
+	const git_config *cfg,
+	const char *name);
+
+/**
+ * Get the value of an integer config variable.
+ *
+ * All config files will be looked into, in the order of their
+ * defined level. A higher level means a higher priority. The
+ * first occurrence of the variable will be returned here.
+ *
+ * @param out pointer to the variable where the value should be stored
+ * @param cfg where to look for the variable
+ * @param name the variable's name
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_config_get_int32(int32_t *out, const git_config *cfg, const char *name);
+
+/**
+ * Get the value of a long integer config variable.
+ *
+ * All config files will be looked into, in the order of their
+ * defined level. A higher level means a higher priority. The
+ * first occurrence of the variable will be returned here.
+ *
+ * @param out pointer to the variable where the value should be stored
+ * @param cfg where to look for the variable
+ * @param name the variable's name
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_config_get_int64(int64_t *out, const git_config *cfg, const char *name);
+
+/**
+ * Get the value of a boolean config variable.
+ *
+ * This function uses the usual C convention of 0 being false and
+ * anything else true.
+ *
+ * All config files will be looked into, in the order of their
+ * defined level. A higher level means a higher priority. The
+ * first occurrence of the variable will be returned here.
+ *
+ * @param out pointer to the variable where the value should be stored
+ * @param cfg where to look for the variable
+ * @param name the variable's name
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_config_get_bool(int *out, const git_config *cfg, const char *name);
+
+/**
+ * Get the value of a path config variable.
+ *
+ * A leading '~' will be expanded to the global search path (which
+ * defaults to the user's home directory but can be overridden via
+ * `git_libgit2_opts()`.
+ *
+ * All config files will be looked into, in the order of their
+ * defined level. A higher level means a higher priority. The
+ * first occurrence of the variable will be returned here.
+ *
+ * @param out the buffer in which to store the result
+ * @param cfg where to look for the variable
+ * @param name the variable's name
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_config_get_path(git_buf *out, const git_config *cfg, const char *name);
+
+/**
+ * Get the value of a string config variable.
+ *
+ * This function can only be used on snapshot config objects. The
+ * string is owned by the config and should not be freed by the
+ * user. The pointer will be valid until the config is freed.
+ *
+ * All config files will be looked into, in the order of their
+ * defined level. A higher level means a higher priority. The
+ * first occurrence of the variable will be returned here.
+ *
+ * @param out pointer to the string
+ * @param cfg where to look for the variable
+ * @param name the variable's name
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_config_get_string(const char **out, const git_config *cfg, const char *name);
+
+/**
+ * Get the value of a string config variable.
+ *
+ * The value of the config will be copied into the buffer.
+ *
+ * All config files will be looked into, in the order of their
+ * defined level. A higher level means a higher priority. The
+ * first occurrence of the variable will be returned here.
+ *
+ * @param out buffer in which to store the string
+ * @param cfg where to look for the variable
+ * @param name the variable's name
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_config_get_string_buf(git_buf *out, const git_config *cfg, const char *name);
+
+/**
+ * Get each value of a multivar in a foreach callback
+ *
+ * The callback will be called on each variable found
+ *
+ * The regular expression is applied case-sensitively on the normalized form of
+ * the variable name: the section and variable parts are lower-cased. The
+ * subsection is left unchanged.
+ *
+ * @param cfg where to look for the variable
+ * @param name the variable's name
+ * @param regexp regular expression to filter which variables we're
+ * interested in. Use NULL to indicate all
+ * @param callback the function to be called on each value of the variable
+ * @param payload opaque pointer to pass to the callback
+ */
+GIT_EXTERN(int) git_config_get_multivar_foreach(const git_config *cfg, const char *name, const char *regexp, git_config_foreach_cb callback, void *payload);
+
+/**
+ * Get each value of a multivar
+ *
+ * The regular expression is applied case-sensitively on the normalized form of
+ * the variable name: the section and variable parts are lower-cased. The
+ * subsection is left unchanged.
+ *
+ * @param out pointer to store the iterator
+ * @param cfg where to look for the variable
+ * @param name the variable's name
+ * @param regexp regular expression to filter which variables we're
+ * interested in. Use NULL to indicate all
+ */
+GIT_EXTERN(int) git_config_multivar_iterator_new(git_config_iterator **out, const git_config *cfg, const char *name, const char *regexp);
+
+/**
+ * Return the current entry and advance the iterator
+ *
+ * The pointers returned by this function are valid until the iterator
+ * is freed.
+ *
+ * @param entry pointer to store the entry
+ * @param iter the iterator
+ * @return 0 or an error code. GIT_ITEROVER if the iteration has completed
+ */
+GIT_EXTERN(int) git_config_next(git_config_entry **entry, git_config_iterator *iter);
+
+/**
+ * Free a config iterator
+ *
+ * @param iter the iterator to free
+ */
+GIT_EXTERN(void) git_config_iterator_free(git_config_iterator *iter);
+
+/**
+ * Set the value of an integer config variable in the config file
+ * with the highest level (usually the local one).
+ *
+ * @param cfg where to look for the variable
+ * @param name the variable's name
+ * @param value Integer value for the variable
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_config_set_int32(git_config *cfg, const char *name, int32_t value);
+
+/**
+ * Set the value of a long integer config variable in the config file
+ * with the highest level (usually the local one).
+ *
+ * @param cfg where to look for the variable
+ * @param name the variable's name
+ * @param value Long integer value for the variable
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_config_set_int64(git_config *cfg, const char *name, int64_t value);
+
+/**
+ * Set the value of a boolean config variable in the config file
+ * with the highest level (usually the local one).
+ *
+ * @param cfg where to look for the variable
+ * @param name the variable's name
+ * @param value the value to store
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_config_set_bool(git_config *cfg, const char *name, int value);
+
+/**
+ * Set the value of a string config variable in the config file
+ * with the highest level (usually the local one).
+ *
+ * A copy of the string is made and the user is free to use it
+ * afterwards.
+ *
+ * @param cfg where to look for the variable
+ * @param name the variable's name
+ * @param value the string to store.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_config_set_string(git_config *cfg, const char *name, const char *value);
+
+/**
+ * Set a multivar in the local config file.
+ *
+ * The regular expression is applied case-sensitively on the value.
+ *
+ * @param cfg where to look for the variable
+ * @param name the variable's name
+ * @param regexp a regular expression to indicate which values to replace
+ * @param value the new value.
+ */
+GIT_EXTERN(int) git_config_set_multivar(git_config *cfg, const char *name, const char *regexp, const char *value);
+
+/**
+ * Delete a config variable from the config file
+ * with the highest level (usually the local one).
+ *
+ * @param cfg the configuration
+ * @param name the variable to delete
+ */
+GIT_EXTERN(int) git_config_delete_entry(git_config *cfg, const char *name);
+
+/**
+ * Deletes one or several entries from a multivar in the local config file.
+ *
+ * The regular expression is applied case-sensitively on the value.
+ *
+ * @param cfg where to look for the variables
+ * @param name the variable's name
+ * @param regexp a regular expression to indicate which values to delete
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_config_delete_multivar(git_config *cfg, const char *name, const char *regexp);
+
+/**
+ * Perform an operation on each config variable.
+ *
+ * The callback receives the normalized name and value of each variable
+ * in the config backend, and the data pointer passed to this function.
+ * If the callback returns a non-zero value, the function stops iterating
+ * and returns that value to the caller.
+ *
+ * The pointers passed to the callback are only valid as long as the
+ * iteration is ongoing.
+ *
+ * @param cfg where to get the variables from
+ * @param callback the function to call on each variable
+ * @param payload the data to pass to the callback
+ * @return 0 on success, non-zero callback return value, or error code
+ */
+GIT_EXTERN(int) git_config_foreach(
+	const git_config *cfg,
+	git_config_foreach_cb callback,
+	void *payload);
+
+/**
+ * Iterate over all the config variables
+ *
+ * Use `git_config_next` to advance the iteration and
+ * `git_config_iterator_free` when done.
+ *
+ * @param out pointer to store the iterator
+ * @param cfg where to ge the variables from
+ */
+GIT_EXTERN(int) git_config_iterator_new(git_config_iterator **out, const git_config *cfg);
+
+/**
+ * Iterate over all the config variables whose name matches a pattern
+ *
+ * Use `git_config_next` to advance the iteration and
+ * `git_config_iterator_free` when done.
+ *
+ * The regular expression is applied case-sensitively on the normalized form of
+ * the variable name: the section and variable parts are lower-cased. The
+ * subsection is left unchanged.
+ *
+ * @param out pointer to store the iterator
+ * @param cfg where to ge the variables from
+ * @param regexp regular expression to match the names
+ */
+GIT_EXTERN(int) git_config_iterator_glob_new(git_config_iterator **out, const git_config *cfg, const char *regexp);
+
+/**
+ * Perform an operation on each config variable matching a regular expression.
+ *
+ * This behaviors like `git_config_foreach` with an additional filter of a
+ * regular expression that filters which config keys are passed to the
+ * callback.
+ *
+ * The regular expression is applied case-sensitively on the normalized form of
+ * the variable name: the section and variable parts are lower-cased. The
+ * subsection is left unchanged.
+ *
+ * The regular expression is applied case-sensitively on the normalized form of
+ * the variable name: the case-insensitive parts are lower-case.
+ *
+ * @param cfg where to get the variables from
+ * @param regexp regular expression to match against config names
+ * @param callback the function to call on each variable
+ * @param payload the data to pass to the callback
+ * @return 0 or the return value of the callback which didn't return 0
+ */
+GIT_EXTERN(int) git_config_foreach_match(
+	const git_config *cfg,
+	const char *regexp,
+	git_config_foreach_cb callback,
+	void *payload);
+
+/**
+ * Query the value of a config variable and return it mapped to
+ * an integer constant.
+ *
+ * This is a helper method to easily map different possible values
+ * to a variable to integer constants that easily identify them.
+ *
+ * A mapping array looks as follows:
+ *
+ *	git_cvar_map autocrlf_mapping[] = {
+ *		{GIT_CVAR_FALSE, NULL, GIT_AUTO_CRLF_FALSE},
+ *		{GIT_CVAR_TRUE, NULL, GIT_AUTO_CRLF_TRUE},
+ *		{GIT_CVAR_STRING, "input", GIT_AUTO_CRLF_INPUT},
+ *		{GIT_CVAR_STRING, "default", GIT_AUTO_CRLF_DEFAULT}};
+ *
+ * On any "false" value for the variable (e.g. "false", "FALSE", "no"), the
+ * mapping will store `GIT_AUTO_CRLF_FALSE` in the `out` parameter.
+ *
+ * The same thing applies for any "true" value such as "true", "yes" or "1", storing
+ * the `GIT_AUTO_CRLF_TRUE` variable.
+ *
+ * Otherwise, if the value matches the string "input" (with case insensitive comparison),
+ * the given constant will be stored in `out`, and likewise for "default".
+ *
+ * If not a single match can be made to store in `out`, an error code will be
+ * returned.
+ *
+ * @param out place to store the result of the mapping
+ * @param cfg config file to get the variables from
+ * @param name name of the config variable to lookup
+ * @param maps array of `git_cvar_map` objects specifying the possible mappings
+ * @param map_n number of mapping objects in `maps`
+ * @return 0 on success, error code otherwise
+ */
+GIT_EXTERN(int) git_config_get_mapped(
+	int *out,
+	const git_config *cfg,
+	const char *name,
+	const git_cvar_map *maps,
+	size_t map_n);
+
+/**
+ * Maps a string value to an integer constant
+ *
+ * @param out place to store the result of the parsing
+ * @param maps array of `git_cvar_map` objects specifying the possible mappings
+ * @param map_n number of mapping objects in `maps`
+ * @param value value to parse
+ */
+GIT_EXTERN(int) git_config_lookup_map_value(
+	int *out,
+	const git_cvar_map *maps,
+	size_t map_n,
+	const char *value);
+
+/**
+ * Parse a string value as a bool.
+ *
+ * Valid values for true are: 'true', 'yes', 'on', 1 or any
+ *  number different from 0
+ * Valid values for false are: 'false', 'no', 'off', 0
+ *
+ * @param out place to store the result of the parsing
+ * @param value value to parse
+ */
+GIT_EXTERN(int) git_config_parse_bool(int *out, const char *value);
+
+/**
+ * Parse a string value as an int32.
+ *
+ * An optional value suffix of 'k', 'm', or 'g' will
+ * cause the value to be multiplied by 1024, 1048576,
+ * or 1073741824 prior to output.
+ *
+ * @param out place to store the result of the parsing
+ * @param value value to parse
+ */
+GIT_EXTERN(int) git_config_parse_int32(int32_t *out, const char *value);
+
+/**
+ * Parse a string value as an int64.
+ *
+ * An optional value suffix of 'k', 'm', or 'g' will
+ * cause the value to be multiplied by 1024, 1048576,
+ * or 1073741824 prior to output.
+ *
+ * @param out place to store the result of the parsing
+ * @param value value to parse
+ */
+GIT_EXTERN(int) git_config_parse_int64(int64_t *out, const char *value);
+
+/**
+ * Parse a string value as a path.
+ *
+ * A leading '~' will be expanded to the global search path (which
+ * defaults to the user's home directory but can be overridden via
+ * `git_libgit2_opts()`.
+ *
+ * If the value does not begin with a tilde, the input will be
+ * returned.
+ *
+ * @param out placae to store the result of parsing
+ * @param value the path to evaluate
+ */
+GIT_EXTERN(int) git_config_parse_path(git_buf *out, const char *value);
+
+/**
+ * Perform an operation on each config variable in given config backend
+ * matching a regular expression.
+ *
+ * This behaviors like `git_config_foreach_match` except instead of all config
+ * entries it just enumerates through the given backend entry.
+ *
+ * The regular expression is applied case-sensitively on the normalized form of
+ * the variable name: the section and variable parts are lower-cased. The
+ * subsection is left unchanged.
+ *
+ * @param backend where to get the variables from
+ * @param regexp regular expression to match against config names (can be NULL)
+ * @param callback the function to call on each variable
+ * @param payload the data to pass to the callback
+ */
+GIT_EXTERN(int) git_config_backend_foreach_match(
+	git_config_backend *backend,
+	const char *regexp,
+	git_config_foreach_cb callback,
+	void *payload);
+
+
+/**
+ * Lock the backend with the highest priority
+ *
+ * Locking disallows anybody else from writing to that backend. Any
+ * updates made after locking will not be visible to a reader until
+ * the file is unlocked.
+ *
+ * You can apply the changes by calling `git_transaction_commit()`
+ * before freeing the transaction. Either of these actions will unlock
+ * the config.
+ *
+ * @param tx the resulting transaction, use this to commit or undo the
+ * changes
+ * @param cfg the configuration in which to lock
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_config_lock(git_transaction **tx, git_config *cfg);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/cred_helpers.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/cred_helpers.h b/vendor/libgit2-sys/libgit2/include/git2/cred_helpers.h
new file mode 100644
index 0000000..1416d56
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/cred_helpers.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_cred_helpers_h__
+#define INCLUDE_git_cred_helpers_h__
+
+#include "transport.h"
+
+/**
+ * @file git2/cred_helpers.h
+ * @brief Utility functions for credential management
+ * @defgroup git_cred_helpers credential management helpers
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Payload for git_cred_stock_userpass_plaintext.
+ */
+typedef struct git_cred_userpass_payload {
+	const char *username;
+	const char *password;
+} git_cred_userpass_payload;
+
+
+/**
+ * Stock callback usable as a git_cred_acquire_cb.  This calls
+ * git_cred_userpass_plaintext_new unless the protocol has not specified
+ * `GIT_CREDTYPE_USERPASS_PLAINTEXT` as an allowed type.
+ *
+ * @param cred The newly created credential object.
+ * @param url The resource for which we are demanding a credential.
+ * @param user_from_url The username that was embedded in a "user\@host"
+ *                          remote url, or NULL if not included.
+ * @param allowed_types A bitmask stating which cred types are OK to return.
+ * @param payload The payload provided when specifying this callback.  (This is
+ *        interpreted as a `git_cred_userpass_payload*`.)
+ */
+GIT_EXTERN(int) git_cred_userpass(
+		git_cred **cred,
+		const char *url,
+		const char *user_from_url,
+		unsigned int allowed_types,
+		void *payload);
+
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/describe.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/describe.h b/vendor/libgit2-sys/libgit2/include/git2/describe.h
new file mode 100644
index 0000000..eb0355b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/describe.h
@@ -0,0 +1,166 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_describe_h__
+#define INCLUDE_git_describe_h__
+
+#include "common.h"
+#include "types.h"
+#include "buffer.h"
+
+/**
+ * @file git2/describe.h
+ * @brief Git describing routines
+ * @defgroup git_describe Git describing routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Reference lookup strategy
+ *
+ * These behave like the --tags and --all options to git-describe,
+ * namely they say to look for any reference in either refs/tags/ or
+ * refs/ respectively.
+ */
+typedef enum {
+	GIT_DESCRIBE_DEFAULT,
+	GIT_DESCRIBE_TAGS,
+	GIT_DESCRIBE_ALL,
+} git_describe_strategy_t;
+
+/**
+ * Describe options structure
+ *
+ * Initialize with `GIT_DESCRIBE_OPTIONS_INIT` macro to correctly set
+ * the `version` field.  E.g.
+ *
+ *		git_describe_options opts = GIT_DESCRIBE_OPTIONS_INIT;
+ */
+typedef struct git_describe_options {
+	unsigned int version;
+
+	unsigned int max_candidates_tags; /**< default: 10 */
+	unsigned int describe_strategy; /**< default: GIT_DESCRIBE_DEFAULT */
+	const char *pattern;
+	/**
+	 * When calculating the distance from the matching tag or
+	 * reference, only walk down the first-parent ancestry.
+	 */
+	int only_follow_first_parent;
+	/**
+	 * If no matching tag or reference is found, the describe
+	 * operation would normally fail. If this option is set, it
+	 * will instead fall back to showing the full id of the
+	 * commit.
+	 */
+	int show_commit_oid_as_fallback;
+} git_describe_options;
+
+#define GIT_DESCRIBE_DEFAULT_MAX_CANDIDATES_TAGS 10
+#define GIT_DESCRIBE_DEFAULT_ABBREVIATED_SIZE 7
+
+#define GIT_DESCRIBE_OPTIONS_VERSION 1
+#define GIT_DESCRIBE_OPTIONS_INIT { \
+	GIT_DESCRIBE_OPTIONS_VERSION, \
+	GIT_DESCRIBE_DEFAULT_MAX_CANDIDATES_TAGS, \
+}
+
+GIT_EXTERN(int) git_describe_init_options(git_describe_options *opts, unsigned int version);
+
+/**
+ * Options for formatting the describe string
+ */
+typedef struct {
+	unsigned int version;
+
+	/**
+	 * Size of the abbreviated commit id to use. This value is the
+	 * lower bound for the length of the abbreviated string. The
+	 * default is 7.
+	 */
+	unsigned int abbreviated_size;
+
+	/**
+	 * Set to use the long format even when a shorter name could be used.
+	 */
+	int always_use_long_format;
+
+	/**
+	 * If the workdir is dirty and this is set, this string will
+	 * be appended to the description string.
+	 */
+	const char *dirty_suffix;
+} git_describe_format_options;
+
+#define GIT_DESCRIBE_FORMAT_OPTIONS_VERSION 1
+#define GIT_DESCRIBE_FORMAT_OPTIONS_INIT { \
+		GIT_DESCRIBE_FORMAT_OPTIONS_VERSION,   \
+		GIT_DESCRIBE_DEFAULT_ABBREVIATED_SIZE, \
+ }
+
+GIT_EXTERN(int) git_describe_init_format_options(git_describe_format_options *opts, unsigned int version);
+
+/**
+ * A struct that stores the result of a describe operation.
+ */
+typedef struct git_describe_result git_describe_result;
+
+/**
+ * Describe a commit
+ *
+ * Perform the describe operation on the given committish object.
+ *
+ * @param result pointer to store the result. You must free this once
+ * you're done with it.
+ * @param committish a committish to describe
+ * @param opts the lookup options (or NULL for defaults)
+ */
+GIT_EXTERN(int) git_describe_commit(
+	git_describe_result **result,
+	git_object *committish,
+	git_describe_options *opts);
+
+/**
+ * Describe a commit
+ *
+ * Perform the describe operation on the current commit and the
+ * worktree. After peforming describe on HEAD, a status is run and the
+ * description is considered to be dirty if there are.
+ *
+ * @param out pointer to store the result. You must free this once
+ * you're done with it.
+ * @param repo the repository in which to perform the describe
+ * @param opts the lookup options (or NULL for defaults)
+ */
+GIT_EXTERN(int) git_describe_workdir(
+	git_describe_result **out,
+	git_repository *repo,
+	git_describe_options *opts);
+
+/**
+ * Print the describe result to a buffer
+ *
+ * @param out The buffer to store the result
+ * @param result the result from `git_describe_commit()` or
+ * `git_describe_workdir()`.
+ * @param opts the formatting options (or NULL for defaults)
+ */
+GIT_EXTERN(int) git_describe_format(
+	git_buf *out,
+	const git_describe_result *result,
+	const git_describe_format_options *opts);
+
+/**
+ * Free the describe result.
+ */
+GIT_EXTERN(void) git_describe_result_free(git_describe_result *result);
+
+/** @} */
+GIT_END_DECL
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/diff.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/diff.h b/vendor/libgit2-sys/libgit2/include/git2/diff.h
new file mode 100644
index 0000000..86009f5
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/diff.h
@@ -0,0 +1,1458 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_diff_h__
+#define INCLUDE_git_diff_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+#include "tree.h"
+#include "refs.h"
+
+/**
+ * @file git2/diff.h
+ * @brief Git tree and file differencing routines.
+ *
+ * Overview
+ * --------
+ *
+ * Calculating diffs is generally done in two phases: building a list of
+ * diffs then traversing it.  This makes is easier to share logic across
+ * the various types of diffs (tree vs tree, workdir vs index, etc.), and
+ * also allows you to insert optional diff post-processing phases,
+ * such as rename detection, in between the steps.  When you are done with
+ * a diff object, it must be freed.
+ *
+ * Terminology
+ * -----------
+ *
+ * To understand the diff APIs, you should know the following terms:
+ *
+ * - A `diff` represents the cumulative list of differences between two
+ *   snapshots of a repository (possibly filtered by a set of file name
+ *   patterns).  This is the `git_diff` object.
+ *
+ * - A `delta` is a file pair with an old and new revision.  The old version
+ *   may be absent if the file was just created and the new version may be
+ *   absent if the file was deleted.  A diff is mostly just a list of deltas.
+ *
+ * - A `binary` file / delta is a file (or pair) for which no text diffs
+ *   should be generated.  A diff can contain delta entries that are
+ *   binary, but no diff content will be output for those files.  There is
+ *   a base heuristic for binary detection and you can further tune the
+ *   behavior with git attributes or diff flags and option settings.
+ *
+ * - A `hunk` is a span of modified lines in a delta along with some stable
+ *   surrounding context.  You can configure the amount of context and other
+ *   properties of how hunks are generated.  Each hunk also comes with a
+ *   header that described where it starts and ends in both the old and new
+ *   versions in the delta.
+ *
+ * - A `line` is a range of characters inside a hunk.  It could be a context
+ *   line (i.e. in both old and new versions), an added line (i.e. only in
+ *   the new version), or a removed line (i.e. only in the old version).
+ *   Unfortunately, we don't know anything about the encoding of data in the
+ *   file being diffed, so we cannot tell you much about the line content.
+ *   Line data will not be NUL-byte terminated, however, because it will be
+ *   just a span of bytes inside the larger file.
+ *
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Flags for diff options.  A combination of these flags can be passed
+ * in via the `flags` value in the `git_diff_options`.
+ */
+typedef enum {
+	/** Normal diff, the default */
+	GIT_DIFF_NORMAL = 0,
+
+	/*
+	 * Options controlling which files will be in the diff
+	 */
+
+	/** Reverse the sides of the diff */
+	GIT_DIFF_REVERSE = (1u << 0),
+
+	/** Include ignored files in the diff */
+	GIT_DIFF_INCLUDE_IGNORED = (1u << 1),
+
+	/** Even with GIT_DIFF_INCLUDE_IGNORED, an entire ignored directory
+	 *  will be marked with only a single entry in the diff; this flag
+	 *  adds all files under the directory as IGNORED entries, too.
+	 */
+	GIT_DIFF_RECURSE_IGNORED_DIRS = (1u << 2),
+
+	/** Include untracked files in the diff */
+	GIT_DIFF_INCLUDE_UNTRACKED = (1u << 3),
+
+	/** Even with GIT_DIFF_INCLUDE_UNTRACKED, an entire untracked
+	 *  directory will be marked with only a single entry in the diff
+	 *  (a la what core Git does in `git status`); this flag adds *all*
+	 *  files under untracked directories as UNTRACKED entries, too.
+	 */
+	GIT_DIFF_RECURSE_UNTRACKED_DIRS = (1u << 4),
+
+	/** Include unmodified files in the diff */
+	GIT_DIFF_INCLUDE_UNMODIFIED = (1u << 5),
+
+	/** Normally, a type change between files will be converted into a
+	 *  DELETED record for the old and an ADDED record for the new; this
+	 *  options enabled the generation of TYPECHANGE delta records.
+	 */
+	GIT_DIFF_INCLUDE_TYPECHANGE = (1u << 6),
+
+	/** Even with GIT_DIFF_INCLUDE_TYPECHANGE, blob->tree changes still
+	 *  generally show as a DELETED blob.  This flag tries to correctly
+	 *  label blob->tree transitions as TYPECHANGE records with new_file's
+	 *  mode set to tree.  Note: the tree SHA will not be available.
+	 */
+	GIT_DIFF_INCLUDE_TYPECHANGE_TREES = (1u << 7),
+
+	/** Ignore file mode changes */
+	GIT_DIFF_IGNORE_FILEMODE = (1u << 8),
+
+	/** Treat all submodules as unmodified */
+	GIT_DIFF_IGNORE_SUBMODULES = (1u << 9),
+
+	/** Use case insensitive filename comparisons */
+	GIT_DIFF_IGNORE_CASE = (1u << 10),
+
+	/** May be combined with `GIT_DIFF_IGNORE_CASE` to specify that a file
+	 *  that has changed case will be returned as an add/delete pair.
+	 */
+	GIT_DIFF_INCLUDE_CASECHANGE = (1u << 11),
+
+	/** If the pathspec is set in the diff options, this flags indicates
+	 *  that the paths will be treated as literal paths instead of
+	 *  fnmatch patterns.  Each path in the list must either be a full
+	 *  path to a file or a directory.  (A trailing slash indicates that
+	 *  the path will _only_ match a directory).  If a directory is
+	 *  specified, all children will be included.
+	 */
+	GIT_DIFF_DISABLE_PATHSPEC_MATCH = (1u << 12),
+
+	/** Disable updating of the `binary` flag in delta records.  This is
+	 *  useful when iterating over a diff if you don't need hunk and data
+	 *  callbacks and want to avoid having to load file completely.
+	 */
+	GIT_DIFF_SKIP_BINARY_CHECK = (1u << 13),
+
+	/** When diff finds an untracked directory, to match the behavior of
+	 *  core Git, it scans the contents for IGNORED and UNTRACKED files.
+	 *  If *all* contents are IGNORED, then the directory is IGNORED; if
+	 *  any contents are not IGNORED, then the directory is UNTRACKED.
+	 *  This is extra work that may not matter in many cases.  This flag
+	 *  turns off that scan and immediately labels an untracked directory
+	 *  as UNTRACKED (changing the behavior to not match core Git).
+	 */
+	GIT_DIFF_ENABLE_FAST_UNTRACKED_DIRS = (1u << 14),
+
+	/** When diff finds a file in the working directory with stat
+	 * information different from the index, but the OID ends up being the
+	 * same, write the correct stat information into the index.  Note:
+	 * without this flag, diff will always leave the index untouched.
+	 */
+	GIT_DIFF_UPDATE_INDEX = (1u << 15),
+
+	/** Include unreadable files in the diff */
+	GIT_DIFF_INCLUDE_UNREADABLE = (1u << 16),
+	
+	/** Include unreadable files in the diff */
+	GIT_DIFF_INCLUDE_UNREADABLE_AS_UNTRACKED = (1u << 17),
+
+	/*
+	 * Options controlling how output will be generated
+	 */
+
+	/** Treat all files as text, disabling binary attributes & detection */
+	GIT_DIFF_FORCE_TEXT = (1u << 20),
+	/** Treat all files as binary, disabling text diffs */
+	GIT_DIFF_FORCE_BINARY = (1u << 21),
+
+	/** Ignore all whitespace */
+	GIT_DIFF_IGNORE_WHITESPACE = (1u << 22),
+	/** Ignore changes in amount of whitespace */
+	GIT_DIFF_IGNORE_WHITESPACE_CHANGE = (1u << 23),
+	/** Ignore whitespace at end of line */
+	GIT_DIFF_IGNORE_WHITESPACE_EOL = (1u << 24),
+
+	/** When generating patch text, include the content of untracked
+	 *  files.  This automatically turns on GIT_DIFF_INCLUDE_UNTRACKED but
+	 *  it does not turn on GIT_DIFF_RECURSE_UNTRACKED_DIRS.  Add that
+	 *  flag if you want the content of every single UNTRACKED file.
+	 */
+	GIT_DIFF_SHOW_UNTRACKED_CONTENT = (1u << 25),
+
+	/** When generating output, include the names of unmodified files if
+	 *  they are included in the git_diff.  Normally these are skipped in
+	 *  the formats that list files (e.g. name-only, name-status, raw).
+	 *  Even with this, these will not be included in patch format.
+	 */
+	GIT_DIFF_SHOW_UNMODIFIED = (1u << 26),
+
+	/** Use the "patience diff" algorithm */
+	GIT_DIFF_PATIENCE = (1u << 28),
+	/** Take extra time to find minimal diff */
+	GIT_DIFF_MINIMAL = (1u << 29),
+
+	/** Include the necessary deflate / delta information so that `git-apply`
+	 *  can apply given diff information to binary files.
+	 */
+	GIT_DIFF_SHOW_BINARY = (1u << 30),
+
+	/** Use a heuristic that takes indentation and whitespace into account
+	 * which generally can produce better diffs when dealing with ambiguous
+	 * diff hunks.
+	 */
+	GIT_DIFF_INDENT_HEURISTIC = (1u << 31),
+} git_diff_option_t;
+
+/**
+ * The diff object that contains all individual file deltas.
+ *
+ * This is an opaque structure which will be allocated by one of the diff
+ * generator functions below (such as `git_diff_tree_to_tree`).  You are
+ * responsible for releasing the object memory when done, using the
+ * `git_diff_free()` function.
+ */
+typedef struct git_diff git_diff;
+
+/**
+ * Flags for the delta object and the file objects on each side.
+ *
+ * These flags are used for both the `flags` value of the `git_diff_delta`
+ * and the flags for the `git_diff_file` objects representing the old and
+ * new sides of the delta.  Values outside of this public range should be
+ * considered reserved for internal or future use.
+ */
+typedef enum {
+	GIT_DIFF_FLAG_BINARY     = (1u << 0), /**< file(s) treated as binary data */
+	GIT_DIFF_FLAG_NOT_BINARY = (1u << 1), /**< file(s) treated as text data */
+	GIT_DIFF_FLAG_VALID_ID   = (1u << 2), /**< `id` value is known correct */
+	GIT_DIFF_FLAG_EXISTS     = (1u << 3), /**< file exists at this side of the delta */
+} git_diff_flag_t;
+
+/**
+ * What type of change is described by a git_diff_delta?
+ *
+ * `GIT_DELTA_RENAMED` and `GIT_DELTA_COPIED` will only show up if you run
+ * `git_diff_find_similar()` on the diff object.
+ *
+ * `GIT_DELTA_TYPECHANGE` only shows up given `GIT_DIFF_INCLUDE_TYPECHANGE`
+ * in the option flags (otherwise type changes will be split into ADDED /
+ * DELETED pairs).
+ */
+typedef enum {
+	GIT_DELTA_UNMODIFIED = 0,  /**< no changes */
+	GIT_DELTA_ADDED = 1,	   /**< entry does not exist in old version */
+	GIT_DELTA_DELETED = 2,	   /**< entry does not exist in new version */
+	GIT_DELTA_MODIFIED = 3,    /**< entry content changed between old and new */
+	GIT_DELTA_RENAMED = 4,     /**< entry was renamed between old and new */
+	GIT_DELTA_COPIED = 5,      /**< entry was copied from another old entry */
+	GIT_DELTA_IGNORED = 6,     /**< entry is ignored item in workdir */
+	GIT_DELTA_UNTRACKED = 7,   /**< entry is untracked item in workdir */
+	GIT_DELTA_TYPECHANGE = 8,  /**< type of entry changed between old and new */
+	GIT_DELTA_UNREADABLE = 9,  /**< entry is unreadable */
+	GIT_DELTA_CONFLICTED = 10, /**< entry in the index is conflicted */
+} git_delta_t;
+
+/**
+ * Description of one side of a delta.
+ *
+ * Although this is called a "file", it could represent a file, a symbolic
+ * link, a submodule commit id, or even a tree (although that only if you
+ * are tracking type changes or ignored/untracked directories).
+ *
+ * The `id` is the `git_oid` of the item.  If the entry represents an
+ * absent side of a diff (e.g. the `old_file` of a `GIT_DELTA_ADDED` delta),
+ * then the oid will be zeroes.
+ *
+ * `path` is the NUL-terminated path to the entry relative to the working
+ * directory of the repository.
+ *
+ * `size` is the size of the entry in bytes.
+ *
+ * `flags` is a combination of the `git_diff_flag_t` types
+ *
+ * `mode` is, roughly, the stat() `st_mode` value for the item.  This will
+ * be restricted to one of the `git_filemode_t` values.
+ *
+ * The `id_abbrev` represents the known length of the `id` field, when
+ * converted to a hex string.  It is generally `GIT_OID_HEXSZ`, unless this
+ * delta was created from reading a patch file, in which case it may be
+ * abbreviated to something reasonable, like 7 characters.
+ */
+typedef struct {
+	git_oid     id;
+	const char *path;
+	git_off_t   size;
+	uint32_t    flags;
+	uint16_t    mode;
+	uint16_t    id_abbrev;
+} git_diff_file;
+
+/**
+ * Description of changes to one entry.
+ *
+ * When iterating over a diff, this will be passed to most callbacks and
+ * you can use the contents to understand exactly what has changed.
+ *
+ * The `old_file` represents the "from" side of the diff and the `new_file`
+ * represents to "to" side of the diff.  What those means depend on the
+ * function that was used to generate the diff and will be documented below.
+ * You can also use the `GIT_DIFF_REVERSE` flag to flip it around.
+ *
+ * Although the two sides of the delta are named "old_file" and "new_file",
+ * they actually may correspond to entries that represent a file, a symbolic
+ * link, a submodule commit id, or even a tree (if you are tracking type
+ * changes or ignored/untracked directories).
+ *
+ * Under some circumstances, in the name of efficiency, not all fields will
+ * be filled in, but we generally try to fill in as much as possible.  One
+ * example is that the "flags" field may not have either the `BINARY` or the
+ * `NOT_BINARY` flag set to avoid examining file contents if you do not pass
+ * in hunk and/or line callbacks to the diff foreach iteration function.  It
+ * will just use the git attributes for those files.
+ *
+ * The similarity score is zero unless you call `git_diff_find_similar()`
+ * which does a similarity analysis of files in the diff.  Use that
+ * function to do rename and copy detection, and to split heavily modified
+ * files in add/delete pairs.  After that call, deltas with a status of
+ * GIT_DELTA_RENAMED or GIT_DELTA_COPIED will have a similarity score
+ * between 0 and 100 indicating how similar the old and new sides are.
+ *
+ * If you ask `git_diff_find_similar` to find heavily modified files to
+ * break, but to not *actually* break the records, then GIT_DELTA_MODIFIED
+ * records may have a non-zero similarity score if the self-similarity is
+ * below the split threshold.  To display this value like core Git, invert
+ * the score (a la `printf("M%03d", 100 - delta->similarity)`).
+ */
+typedef struct {
+	git_delta_t   status;
+	uint32_t      flags;	   /**< git_diff_flag_t values */
+	uint16_t      similarity;  /**< for RENAMED and COPIED, value 0-100 */
+	uint16_t      nfiles;	   /**< number of files in this delta */
+	git_diff_file old_file;
+	git_diff_file new_file;
+} git_diff_delta;
+
+/**
+ * Diff notification callback function.
+ *
+ * The callback will be called for each file, just before the `git_delta_t`
+ * gets inserted into the diff.
+ *
+ * When the callback:
+ * - returns < 0, the diff process will be aborted.
+ * - returns > 0, the delta will not be inserted into the diff, but the
+ *		diff process continues.
+ * - returns 0, the delta is inserted into the diff, and the diff process
+ *		continues.
+ */
+typedef int (*git_diff_notify_cb)(
+	const git_diff *diff_so_far,
+	const git_diff_delta *delta_to_add,
+	const char *matched_pathspec,
+	void *payload);
+
+/**
+ * Diff progress callback.
+ *
+ * Called before each file comparison.
+ *
+ * @param diff_so_far The diff being generated.
+ * @param old_path The path to the old file or NULL.
+ * @param new_path The path to the new file or NULL.
+ * @return Non-zero to abort the diff.
+ */
+typedef int (*git_diff_progress_cb)(
+	const git_diff *diff_so_far,
+	const char *old_path,
+	const char *new_path,
+	void *payload);
+
+/**
+ * Structure describing options about how the diff should be executed.
+ *
+ * Setting all values of the structure to zero will yield the default
+ * values.  Similarly, passing NULL for the options structure will
+ * give the defaults.  The default values are marked below.
+ *
+ * - `flags` is a combination of the `git_diff_option_t` values above
+ * - `context_lines` is the number of unchanged lines that define the
+ *    boundary of a hunk (and to display before and after)
+ * - `interhunk_lines` is the maximum number of unchanged lines between
+ *    hunk boundaries before the hunks will be merged into a one.
+ * - `old_prefix` is the virtual "directory" to prefix to old file names
+ *   in hunk headers (default "a")
+ * - `new_prefix` is the virtual "directory" to prefix to new file names
+ *   in hunk headers (default "b")
+ * - `pathspec` is an array of paths / fnmatch patterns to constrain diff
+ * - `max_size` is a file size (in bytes) above which a blob will be marked
+ *   as binary automatically; pass a negative value to disable.
+ * - `notify_cb` is an optional callback function, notifying the consumer of
+ *   changes to the diff as new deltas are added.
+ * - `progress_cb` is an optional callback function, notifying the consumer of
+ *   which files are being examined as the diff is generated.
+ * - `payload` is the payload to pass to the callback functions.
+ * - `ignore_submodules` overrides the submodule ignore setting for all
+ *   submodules in the diff.
+ */
+typedef struct {
+	unsigned int version;      /**< version for the struct */
+	uint32_t flags;            /**< defaults to GIT_DIFF_NORMAL */
+
+	/* options controlling which files are in the diff */
+
+	git_submodule_ignore_t ignore_submodules; /**< submodule ignore rule */
+	git_strarray       pathspec;     /**< defaults to include all paths */
+	git_diff_notify_cb   notify_cb;
+	git_diff_progress_cb progress_cb;
+	void                *payload;
+
+	/* options controlling how to diff text is generated */
+
+	uint32_t    context_lines;    /**< defaults to 3 */
+	uint32_t    interhunk_lines;  /**< defaults to 0 */
+	uint16_t    id_abbrev;       /**< default 'core.abbrev' or 7 if unset */
+	git_off_t   max_size;         /**< defaults to 512MB */
+	const char *old_prefix;       /**< defaults to "a" */
+	const char *new_prefix;       /**< defaults to "b" */
+} git_diff_options;
+
+/* The current version of the diff options structure */
+#define GIT_DIFF_OPTIONS_VERSION 1
+
+/* Stack initializer for diff options.  Alternatively use
+ * `git_diff_options_init` programmatic initialization.
+ */
+#define GIT_DIFF_OPTIONS_INIT \
+	{GIT_DIFF_OPTIONS_VERSION, 0, GIT_SUBMODULE_IGNORE_UNSPECIFIED, {NULL,0}, NULL, NULL, NULL, 3}
+
+/**
+ * Initializes a `git_diff_options` with default values. Equivalent to
+ * creating an instance with GIT_DIFF_OPTIONS_INIT.
+ *
+ * @param opts The `git_diff_options` struct to initialize
+ * @param version Version of struct; pass `GIT_DIFF_OPTIONS_VERSION`
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_diff_init_options(
+	git_diff_options *opts,
+	unsigned int version);
+
+/**
+ * When iterating over a diff, callback that will be made per file.
+ *
+ * @param delta A pointer to the delta data for the file
+ * @param progress Goes from 0 to 1 over the diff
+ * @param payload User-specified pointer from foreach function
+ */
+typedef int (*git_diff_file_cb)(
+	const git_diff_delta *delta,
+	float progress,
+	void *payload);
+
+#define GIT_DIFF_HUNK_HEADER_SIZE	128
+
+/**
+ * When producing a binary diff, the binary data returned will be
+ * either the deflated full ("literal") contents of the file, or
+ * the deflated binary delta between the two sides (whichever is
+ * smaller).
+ */
+typedef enum {
+	/** There is no binary delta. */
+	GIT_DIFF_BINARY_NONE,
+
+	/** The binary data is the literal contents of the file. */
+	GIT_DIFF_BINARY_LITERAL,
+
+	/** The binary data is the delta from one side to the other. */
+	GIT_DIFF_BINARY_DELTA,
+} git_diff_binary_t;
+
+/** The contents of one of the files in a binary diff. */
+typedef struct {
+	/** The type of binary data for this file. */
+	git_diff_binary_t type;
+
+	/** The binary data, deflated. */
+	const char *data;
+
+	/** The length of the binary data. */
+	size_t datalen;
+
+	/** The length of the binary data after inflation. */
+	size_t inflatedlen;
+} git_diff_binary_file;
+
+/** Structure describing the binary contents of a diff. */
+typedef struct {
+	/**
+	 * Whether there is data in this binary structure or not.  If this
+	 * is `1`, then this was produced and included binary content.  If
+	 * this is `0` then this was generated knowing only that a binary
+	 * file changed but without providing the data, probably from a patch
+	 * that said `Binary files a/file.txt and b/file.txt differ`.
+	 */
+	unsigned int contains_data;
+	git_diff_binary_file old_file; /**< The contents of the old file. */
+	git_diff_binary_file new_file; /**< The contents of the new file. */
+} git_diff_binary;
+
+/**
+* When iterating over a diff, callback that will be made for
+* binary content within the diff.
+*/
+typedef int(*git_diff_binary_cb)(
+	const git_diff_delta *delta,
+	const git_diff_binary *binary,
+	void *payload);
+
+/**
+ * Structure describing a hunk of a diff.
+ */
+typedef struct {
+	int    old_start;     /**< Starting line number in old_file */
+	int    old_lines;     /**< Number of lines in old_file */
+	int    new_start;     /**< Starting line number in new_file */
+	int    new_lines;     /**< Number of lines in new_file */
+	size_t header_len;    /**< Number of bytes in header text */
+	char   header[GIT_DIFF_HUNK_HEADER_SIZE];   /**< Header text, NUL-byte terminated */
+} git_diff_hunk;
+
+/**
+ * When iterating over a diff, callback that will be made per hunk.
+ */
+typedef int (*git_diff_hunk_cb)(
+	const git_diff_delta *delta,
+	const git_diff_hunk *hunk,
+	void *payload);
+
+/**
+ * Line origin constants.
+ *
+ * These values describe where a line came from and will be passed to
+ * the git_diff_line_cb when iterating over a diff.  There are some
+ * special origin constants at the end that are used for the text
+ * output callbacks to demarcate lines that are actually part of
+ * the file or hunk headers.
+ */
+typedef enum {
+	/* These values will be sent to `git_diff_line_cb` along with the line */
+	GIT_DIFF_LINE_CONTEXT   = ' ',
+	GIT_DIFF_LINE_ADDITION  = '+',
+	GIT_DIFF_LINE_DELETION  = '-',
+
+	GIT_DIFF_LINE_CONTEXT_EOFNL = '=', /**< Both files have no LF at end */
+	GIT_DIFF_LINE_ADD_EOFNL = '>',     /**< Old has no LF at end, new does */
+	GIT_DIFF_LINE_DEL_EOFNL = '<',     /**< Old has LF at end, new does not */
+
+	/* The following values will only be sent to a `git_diff_line_cb` when
+	 * the content of a diff is being formatted through `git_diff_print`.
+	 */
+	GIT_DIFF_LINE_FILE_HDR  = 'F',
+	GIT_DIFF_LINE_HUNK_HDR  = 'H',
+	GIT_DIFF_LINE_BINARY    = 'B' /**< For "Binary files x and y differ" */
+} git_diff_line_t;
+
+/**
+ * Structure describing a line (or data span) of a diff.
+ */
+typedef struct {
+	char   origin;       /**< A git_diff_line_t value */
+	int    old_lineno;   /**< Line number in old file or -1 for added line */
+	int    new_lineno;   /**< Line number in new file or -1 for deleted line */
+	int    num_lines;    /**< Number of newline characters in content */
+	size_t content_len;  /**< Number of bytes of data */
+	git_off_t content_offset; /**< Offset in the original file to the content */
+	const char *content; /**< Pointer to diff text, not NUL-byte terminated */
+} git_diff_line;
+
+/**
+ * When iterating over a diff, callback that will be made per text diff
+ * line. In this context, the provided range will be NULL.
+ *
+ * When printing a diff, callback that will be made to output each line
+ * of text.  This uses some extra GIT_DIFF_LINE_... constants for output
+ * of lines of file and hunk headers.
+ */
+typedef int (*git_diff_line_cb)(
+	const git_diff_delta *delta, /**< delta that contains this data */
+	const git_diff_hunk *hunk,   /**< hunk containing this data */
+	const git_diff_line *line,   /**< line data */
+	void *payload);              /**< user reference data */
+
+/**
+ * Flags to control the behavior of diff rename/copy detection.
+ */
+typedef enum {
+	/** Obey `diff.renames`. Overridden by any other GIT_DIFF_FIND_... flag. */
+	GIT_DIFF_FIND_BY_CONFIG = 0,
+
+	/** Look for renames? (`--find-renames`) */
+	GIT_DIFF_FIND_RENAMES = (1u << 0),
+
+	/** Consider old side of MODIFIED for renames? (`--break-rewrites=N`) */
+	GIT_DIFF_FIND_RENAMES_FROM_REWRITES = (1u << 1),
+
+	/** Look for copies? (a la `--find-copies`). */
+	GIT_DIFF_FIND_COPIES = (1u << 2),
+
+	/** Consider UNMODIFIED as copy sources? (`--find-copies-harder`).
+	 *
+	 * For this to work correctly, use GIT_DIFF_INCLUDE_UNMODIFIED when
+	 * the initial `git_diff` is being generated.
+	 */
+	GIT_DIFF_FIND_COPIES_FROM_UNMODIFIED = (1u << 3),
+
+	/** Mark significant rewrites for split (`--break-rewrites=/M`) */
+	GIT_DIFF_FIND_REWRITES = (1u << 4),
+	/** Actually split large rewrites into delete/add pairs */
+	GIT_DIFF_BREAK_REWRITES = (1u << 5),
+	/** Mark rewrites for split and break into delete/add pairs */
+	GIT_DIFF_FIND_AND_BREAK_REWRITES =
+		(GIT_DIFF_FIND_REWRITES | GIT_DIFF_BREAK_REWRITES),
+
+	/** Find renames/copies for UNTRACKED items in working directory.
+	 *
+	 * For this to work correctly, use GIT_DIFF_INCLUDE_UNTRACKED when the
+	 * initial `git_diff` is being generated (and obviously the diff must
+	 * be against the working directory for this to make sense).
+	 */
+	GIT_DIFF_FIND_FOR_UNTRACKED = (1u << 6),
+
+	/** Turn on all finding features. */
+	GIT_DIFF_FIND_ALL = (0x0ff),
+
+	/** Measure similarity ignoring leading whitespace (default) */
+	GIT_DIFF_FIND_IGNORE_LEADING_WHITESPACE = 0,
+	/** Measure similarity ignoring all whitespace */
+	GIT_DIFF_FIND_IGNORE_WHITESPACE = (1u << 12),
+	/** Measure similarity including all data */
+	GIT_DIFF_FIND_DONT_IGNORE_WHITESPACE = (1u << 13),
+	/** Measure similarity only by comparing SHAs (fast and cheap) */
+	GIT_DIFF_FIND_EXACT_MATCH_ONLY = (1u << 14),
+
+	/** Do not break rewrites unless they contribute to a rename.
+	 *
+	 * Normally, GIT_DIFF_FIND_AND_BREAK_REWRITES will measure the self-
+	 * similarity of modified files and split the ones that have changed a
+	 * lot into a DELETE / ADD pair.  Then the sides of that pair will be
+	 * considered candidates for rename and copy detection.
+	 *
+	 * If you add this flag in and the split pair is *not* used for an
+	 * actual rename or copy, then the modified record will be restored to
+	 * a regular MODIFIED record instead of being split.
+	 */
+	GIT_DIFF_BREAK_REWRITES_FOR_RENAMES_ONLY  = (1u << 15),
+
+	/** Remove any UNMODIFIED deltas after find_similar is done.
+	 *
+	 * Using GIT_DIFF_FIND_COPIES_FROM_UNMODIFIED to emulate the
+	 * --find-copies-harder behavior requires building a diff with the
+	 * GIT_DIFF_INCLUDE_UNMODIFIED flag.  If you do not want UNMODIFIED
+	 * records in the final result, pass this flag to have them removed.
+	 */
+	GIT_DIFF_FIND_REMOVE_UNMODIFIED = (1u << 16),
+} git_diff_find_t;
+
+/**
+ * Pluggable similarity metric
+ */
+typedef struct {
+	int (*file_signature)(
+		void **out, const git_diff_file *file,
+		const char *fullpath, void *payload);
+	int (*buffer_signature)(
+		void **out, const git_diff_file *file,
+		const char *buf, size_t buflen, void *payload);
+	void (*free_signature)(void *sig, void *payload);
+	int (*similarity)(int *score, void *siga, void *sigb, void *payload);
+	void *payload;
+} git_diff_similarity_metric;
+
+/**
+ * Control behavior of rename and copy detection
+ *
+ * These options mostly mimic parameters that can be passed to git-diff.
+ *
+ * - `rename_threshold` is the same as the -M option with a value
+ * - `copy_threshold` is the same as the -C option with a value
+ * - `rename_from_rewrite_threshold` matches the top of the -B option
+ * - `break_rewrite_threshold` matches the bottom of the -B option
+ * - `rename_limit` is the maximum number of matches to consider for
+ *   a particular file.  This is a little different from the `-l` option
+ *   to regular Git because we will still process up to this many matches
+ *   before abandoning the search.
+ *
+ * The `metric` option allows you to plug in a custom similarity metric.
+ * Set it to NULL for the default internal metric which is based on sampling
+ * hashes of ranges of data in the file.  The default metric is a pretty
+ * good similarity approximation that should work fairly well for both text
+ * and binary data, and is pretty fast with fixed memory overhead.
+ */
+typedef struct {
+	unsigned int version;
+
+	/**
+	 * Combination of git_diff_find_t values (default GIT_DIFF_FIND_BY_CONFIG).
+	 * NOTE: if you don't explicitly set this, `diff.renames` could be set
+	 * to false, resulting in `git_diff_find_similar` doing nothing.
+	 */
+	uint32_t flags;
+
+	/** Similarity to consider a file renamed (default 50) */
+	uint16_t rename_threshold;
+	/** Similarity of modified to be eligible rename source (default 50) */
+	uint16_t rename_from_rewrite_threshold;
+	/** Similarity to consider a file a copy (default 50) */
+	uint16_t copy_threshold;
+	/** Similarity to split modify into delete/add pair (default 60) */
+	uint16_t break_rewrite_threshold;
+
+	/** Maximum similarity sources to examine for a file (somewhat like
+	 *  git-diff's `-l` option or `diff.renameLimit` config) (default 200)
+	 */
+	size_t rename_limit;
+
+	/** Pluggable similarity metric; pass NULL to use internal metric */
+	git_diff_similarity_metric *metric;
+} git_diff_find_options;
+
+#define GIT_DIFF_FIND_OPTIONS_VERSION 1
+#define GIT_DIFF_FIND_OPTIONS_INIT {GIT_DIFF_FIND_OPTIONS_VERSION}
+
+/**
+ * Initializes a `git_diff_find_options` with default values. Equivalent to
+ * creating an instance with GIT_DIFF_FIND_OPTIONS_INIT.
+ *
+ * @param opts The `git_diff_find_options` struct to initialize
+ * @param version Version of struct; pass `GIT_DIFF_FIND_OPTIONS_VERSION`
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_diff_find_init_options(
+	git_diff_find_options *opts,
+	unsigned int version);
+
+/** @name Diff Generator Functions
+ *
+ * These are the functions you would use to create (or destroy) a
+ * git_diff from various objects in a repository.
+ */
+/**@{*/
+
+/**
+ * Deallocate a diff.
+ *
+ * @param diff The previously created diff; cannot be used after free.
+ */
+GIT_EXTERN(void) git_diff_free(git_diff *diff);
+
+/**
+ * Create a diff with the difference between two tree objects.
+ *
+ * This is equivalent to `git diff <old-tree> <new-tree>`
+ *
+ * The first tree will be used for the "old_file" side of the delta and the
+ * second tree will be used for the "new_file" side of the delta.  You can
+ * pass NULL to indicate an empty tree, although it is an error to pass
+ * NULL for both the `old_tree` and `new_tree`.
+ *
+ * @param diff Output pointer to a git_diff pointer to be allocated.
+ * @param repo The repository containing the trees.
+ * @param old_tree A git_tree object to diff from, or NULL for empty tree.
+ * @param new_tree A git_tree object to diff to, or NULL for empty tree.
+ * @param opts Structure with options to influence diff or NULL for defaults.
+ */
+GIT_EXTERN(int) git_diff_tree_to_tree(
+	git_diff **diff,
+	git_repository *repo,
+	git_tree *old_tree,
+	git_tree *new_tree,
+	const git_diff_options *opts); /**< can be NULL for defaults */
+
+/**
+ * Create a diff between a tree and repository index.
+ *
+ * This is equivalent to `git diff --cached <treeish>` or if you pass
+ * the HEAD tree, then like `git diff --cached`.
+ *
+ * The tree you pass will be used for the "old_file" side of the delta, and
+ * the index will be used for the "new_file" side of the delta.
+ *
+ * If you pass NULL for the index, then the existing index of the `repo`
+ * will be used.  In this case, the index will be refreshed from disk
+ * (if it has changed) before the diff is generated.
+ *
+ * @param diff Output pointer to a git_diff pointer to be allocated.
+ * @param repo The repository containing the tree and index.
+ * @param old_tree A git_tree object to diff from, or NULL for empty tree.
+ * @param index The index to diff with; repo index used if NULL.
+ * @param opts Structure with options to influence diff or NULL for defaults.
+ */
+GIT_EXTERN(int) git_diff_tree_to_index(
+	git_diff **diff,
+	git_repository *repo,
+	git_tree *old_tree,
+	git_index *index,
+	const git_diff_options *opts); /**< can be NULL for defaults */
+
+/**
+ * Create a diff between the repository index and the workdir directory.
+ *
+ * This matches the `git diff` command.  See the note below on
+ * `git_diff_tree_to_workdir` for a discussion of the difference between
+ * `git diff` and `git diff HEAD` and how to emulate a `git diff <treeish>`
+ * using libgit2.
+ *
+ * The index will be used for the "old_file" side of the delta, and the
+ * working directory will be used for the "new_file" side of the delta.
+ *
+ * If you pass NULL for the index, then the existing index of the `repo`
+ * will be used.  In this case, the index will be refreshed from disk
+ * (if it has changed) before the diff is generated.
+ *
+ * @param diff Output pointer to a git_diff pointer to be allocated.
+ * @param repo The repository.
+ * @param index The index to diff from; repo index used if NULL.
+ * @param opts Structure with options to influence diff or NULL for defaults.
+ */
+GIT_EXTERN(int) git_diff_index_to_workdir(
+	git_diff **diff,
+	git_repository *repo,
+	git_index *index,
+	const git_diff_options *opts); /**< can be NULL for defaults */
+
+/**
+ * Create a diff between a tree and the working directory.
+ *
+ * The tree you provide will be used for the "old_file" side of the delta,
+ * and the working directory will be used for the "new_file" side.
+ *
+ * This is not the same as `git diff <treeish>` or `git diff-index
+ * <treeish>`.  Those commands use information from the index, whereas this
+ * function strictly returns the differences between the tree and the files
+ * in the working directory, regardless of the state of the index.  Use
+ * `git_diff_tree_to_workdir_with_index` to emulate those commands.
+ *
+ * To see difference between this and `git_diff_tree_to_workdir_with_index`,
+ * consider the example of a staged file deletion where the file has then
+ * been put back into the working dir and further modified.  The
+ * tree-to-workdir diff for that file is 'modified', but `git diff` would
+ * show status 'deleted' since there is a staged delete.
+ *
+ * @param diff A pointer to a git_diff pointer that will be allocated.
+ * @param repo The repository containing the tree.
+ * @param old_tree A git_tree object to diff from, or NULL for empty tree.
+ * @param opts Structure with options to influence diff or NULL for defaults.
+ */
+GIT_EXTERN(int) git_diff_tree_to_workdir(
+	git_diff **diff,
+	git_repository *repo,
+	git_tree *old_tree,
+	const git_diff_options *opts); /**< can be NULL for defaults */
+
+/**
+ * Create a diff between a tree and the working directory using index data
+ * to account for staged deletes, tracked files, etc.
+ *
+ * This emulates `git diff <tree>` by diffing the tree to the index and
+ * the index to the working directory and blending the results into a
+ * single diff that includes staged deleted, etc.
+ *
+ * @param diff A pointer to a git_diff pointer that will be allocated.
+ * @param repo The repository containing the tree.
+ * @param old_tree A git_tree object to diff from, or NULL for empty tree.
+ * @param opts Structure with options to influence diff or NULL for defaults.
+ */
+GIT_EXTERN(int) git_diff_tree_to_workdir_with_index(
+	git_diff **diff,
+	git_repository *repo,
+	git_tree *old_tree,
+	const git_diff_options *opts); /**< can be NULL for defaults */
+
+/**
+ * Create a diff with the difference between two index objects.
+ *
+ * The first index will be used for the "old_file" side of the delta and the
+ * second index will be used for the "new_file" side of the delta.
+ *
+ * @param diff Output pointer to a git_diff pointer to be allocated.
+ * @param repo The repository containing the indexes.
+ * @param old_index A git_index object to diff from.
+ * @param new_index A git_index object to diff to.
+ * @param opts Structure with options to influence diff or NULL for defaults.
+ */
+GIT_EXTERN(int) git_diff_index_to_index(
+	git_diff **diff,
+	git_repository *repo,
+	git_index *old_index,
+	git_index *new_index,
+	const git_diff_options *opts); /**< can be NULL for defaults */
+
+/**
+ * Merge one diff into another.
+ *
+ * This merges items from the "from" list into the "onto" list.  The
+ * resulting diff will have all items that appear in either list.
+ * If an item appears in both lists, then it will be "merged" to appear
+ * as if the old version was from the "onto" list and the new version
+ * is from the "from" list (with the exception that if the item has a
+ * pending DELETE in the middle, then it will show as deleted).
+ *
+ * @param onto Diff to merge into.
+ * @param from Diff to merge.
+ */
+GIT_EXTERN(int) git_diff_merge(
+	git_diff *onto,
+	const git_diff *from);
+
+/**
+ * Transform a diff marking file renames, copies, etc.
+ *
+ * This modifies a diff in place, replacing old entries that look
+ * like renames or copies with new entries reflecting those changes.
+ * This also will, if requested, break modified files into add/remove
+ * pairs if the amount of change is above a threshold.
+ *
+ * @param diff diff to run detection algorithms on
+ * @param options Control how detection should be run, NULL for defaults
+ * @return 0 on success, -1 on failure
+ */
+GIT_EXTERN(int) git_diff_find_similar(
+	git_diff *diff,
+	const git_diff_find_options *options);
+
+/**@}*/
+
+
+/** @name Diff Processor Functions
+ *
+ * These are the functions you apply to a diff to process it
+ * or read it in some way.
+ */
+/**@{*/
+
+/**
+ * Query how many diff records are there in a diff.
+ *
+ * @param diff A git_diff generated by one of the above functions
+ * @return Count of number of deltas in the list
+ */
+GIT_EXTERN(size_t) git_diff_num_deltas(const git_diff *diff);
+
+/**
+ * Query how many diff deltas are there in a diff filtered by type.
+ *
+ * This works just like `git_diff_entrycount()` with an extra parameter
+ * that is a `git_delta_t` and returns just the count of how many deltas
+ * match that particular type.
+ *
+ * @param diff A git_diff generated by one of the above functions
+ * @param type A git_delta_t value to filter the count
+ * @return Count of number of deltas matching delta_t type
+ */
+GIT_EXTERN(size_t) git_diff_num_deltas_of_type(
+	const git_diff *diff, git_delta_t type);
+
+/**
+ * Return the diff delta for an entry in the diff list.
+ *
+ * The `git_diff_delta` pointer points to internal data and you do not
+ * have to release it when you are done with it.  It will go away when
+ * the * `git_diff` (or any associated `git_patch`) goes away.
+ *
+ * Note that the flags on the delta related to whether it has binary
+ * content or not may not be set if there are no attributes set for the
+ * file and there has been no reason to load the file data at this point.
+ * For now, if you need those flags to be up to date, your only option is
+ * to either use `git_diff_foreach` or create a `git_patch`.
+ *
+ * @param diff Diff list object
+ * @param idx Index into diff list
+ * @return Pointer to git_diff_delta (or NULL if `idx` out of range)
+ */
+GIT_EXTERN(const git_diff_delta *) git_diff_get_delta(
+	const git_diff *diff, size_t idx);
+
+/**
+ * Check if deltas are sorted case sensitively or insensitively.
+ *
+ * @param diff diff to check
+ * @return 0 if case sensitive, 1 if case is ignored
+ */
+GIT_EXTERN(int) git_diff_is_sorted_icase(const git_diff *diff);
+
+/**
+ * Loop over all deltas in a diff issuing callbacks.
+ *
+ * This will iterate through all of the files described in a diff.  You
+ * should provide a file callback to learn about each file.
+ *
+ * The "hunk" and "line" callbacks are optional, and the text diff of the
+ * files will only be calculated if they are not NULL.  Of course, these
+ * callbacks will not be invoked for binary files on the diff or for
+ * files whose only changed is a file mode change.
+ *
+ * Returning a non-zero value from any of the callbacks will terminate
+ * the iteration and return the value to the user.
+ *
+ * @param diff A git_diff generated by one of the above functions.
+ * @param file_cb Callback function to make per file in the diff.
+ * @param binary_cb Optional callback to make for binary files.
+ * @param hunk_cb Optional callback to make per hunk of text diff.  This
+ *                callback is called to describe a range of lines in the
+ *                diff.  It will not be issued for binary files.
+ * @param line_cb Optional callback to make per line of diff text.  This
+ *                same callback will be made for context lines, added, and
+ *                removed lines, and even for a deleted trailing newline.
+ * @param payload Reference pointer that will be passed to your callbacks.
+ * @return 0 on success, non-zero callback return value, or error code
+ */
+GIT_EXTERN(int) git_diff_foreach(
+	git_diff *diff,
+	git_diff_file_cb file_cb,
+	git_diff_binary_cb binary_cb,
+	git_diff_hunk_cb hunk_cb,
+	git_diff_line_cb line_cb,
+	void *payload);
+
+/**
+ * Look up the single character abbreviation for a delta status code.
+ *
+ * When you run `git diff --name-status` it uses single letter codes in
+ * the output such as 'A' for added, 'D' for deleted, 'M' for modified,
+ * etc.  This function converts a git_delta_t value into these letters for
+ * your own purposes.  GIT_DELTA_UNTRACKED will return a space (i.e. ' ').
+ *
+ * @param status The git_delta_t value to look up
+ * @return The single character label for that code
+ */
+GIT_EXTERN(char) git_diff_status_char(git_delta_t status);
+
+/**
+ * Possible output formats for diff data
+ */
+typedef enum {
+	GIT_DIFF_FORMAT_PATCH        = 1u, /**< full git diff */
+	GIT_DIFF_FORMAT_PATCH_HEADER = 2u, /**< just the file headers of patch */
+	GIT_DIFF_FORMAT_RAW          = 3u, /**< like git diff --raw */
+	GIT_DIFF_FORMAT_NAME_ONLY    = 4u, /**< like git diff --name-only */
+	GIT_DIFF_FORMAT_NAME_STATUS  = 5u, /**< like git diff --name-status */
+} git_diff_format_t;
+
+/**
+ * Iterate over a diff generating formatted text output.
+ *
+ * Returning a non-zero value from the callbacks will terminate the
+ * iteration and return the non-zero value to the caller.
+ *
+ * @param diff A git_diff generated by one of the above functions.
+ * @param format A git_diff_format_t value to pick the text format.
+ * @param print_cb Callback to make per line of diff text.
+ * @param payload Reference pointer that will be passed to your callback.
+ * @return 0 on success, non-zero callback return value, or error code
+ */
+GIT_EXTERN(int) git_diff_print(
+	git_diff *diff,
+	git_diff_format_t format,
+	git_diff_line_cb print_cb,
+	void *payload);
+
+/**
+ * Produce the complete formatted text output from a diff into a
+ * buffer.
+ *
+ * @param out A pointer to a user-allocated git_buf that will
+ *            contain the diff text
+ * @param diff A git_diff generated by one of the above functions.
+ * @param format A git_diff_format_t value to pick the text format.
+ * @return 0 on success or error code
+ */
+GIT_EXTERN(int) git_diff_to_buf(
+	git_buf *out,
+	git_diff *diff,
+	git_diff_format_t format);
+
+/**@}*/
+
+
+/*
+ * Misc
+ */
+
+/**
+ * Directly run a diff on two blobs.
+ *
+ * Compared to a file, a blob lacks some contextual information. As such,
+ * the `git_diff_file` given to the callback will have some fake data; i.e.
+ * `mode` will be 0 and `path` will be NULL.
+ *
+ * NULL is allowed for either `old_blob` or `new_blob` and will be treated
+ * as an empty blob, with the `oid` set to NULL in the `git_diff_file` data.
+ * Passing NULL for both blobs is a noop; no callbacks will be made at all.
+ *
+ * We do run a binary content check on the blob content and if either blob
+ * looks like binary data, the `git_diff_delta` binary attribute will be set
+ * to 1 and no call to the hunk_cb nor line_cb will be made (unless you pass
+ * `GIT_DIFF_FORCE_TEXT` of course).
+ *
+ * @param old_blob Blob for old side of diff, or NULL for empty blob
+ * @param old_as_path Treat old blob as if it had this filename; can be NULL
+ * @param new_blob Blob for new side of diff, or NULL for empty blob
+ * @param new_as_path Treat new blob as if it had this filename; can be NULL
+ * @param options Options for diff, or NULL for default options
+ * @param file_cb Callback for "file"; made once if there is a diff; can be NULL
+ * @param binary_cb Callback for binary files; can be NULL
+ * @param hunk_cb Callback for each hunk in diff; can be NULL
+ * @param line_cb Callback for each line in diff; can be NULL
+ * @param payload Payload passed to each callback function
+ * @return 0 on success, non-zero callback return value, or error code
+ */
+GIT_EXTERN(int) git_diff_blobs(
+	const git_blob *old_blob,
+	const char *old_as_path,
+	const git_blob *new_blob,
+	const char *new_as_path,
+	const git_diff_options *options,
+	git_diff_file_cb file_cb,
+	git_diff_binary_cb binary_cb,
+	git_diff_hunk_cb hunk_cb,
+	git_diff_line_cb line_cb,
+	void *payload);
+
+/**
+ * Directly run a diff between a blob and a buffer.
+ *
+ * As with `git_diff_blobs`, comparing a blob and buffer lacks some context,
+ * so the `git_diff_file` parameters to the callbacks will be faked a la the
+ * rules for `git_diff_blobs()`.
+ *
+ * Passing NULL for `old_blob` will be treated as an empty blob (i.e. the
+ * `file_cb` will be invoked with GIT_DELTA_ADDED and the diff will be the
+ * entire content of the buffer added).  Passing NULL to the buffer will do
+ * the reverse, with GIT_DELTA_REMOVED and blob content removed.
+ *
+ * @param old_blob Blob for old side of diff, or NULL for empty blob
+ * @param old_as_path Treat old blob as if it had this filename; can be NULL
+ * @param buffer Raw data for new side of diff, or NULL for empty
+ * @param buffer_len Length of raw data for new side of diff
+ * @param buffer_as_path Treat buffer as if it had this filename; can be NULL
+ * @param options Options for diff, or NULL for default options
+ * @param file_cb Callback for "file"; made once if there is a diff; can be NULL
+ * @param binary_cb Callback for binary files; can be NULL
+ * @param hunk_cb Callback for each hunk in diff; can be NULL
+ * @param line_cb Callback for each line in diff; can be NULL
+ * @param payload Payload passed to each callback function
+ * @return 0 on success, non-zero callback return value, or error code
+ */
+GIT_EXTERN(int) git_diff_blob_to_buffer(
+	const git_blob *old_blob,
+	const char *old_as_path,
+	const char *buffer,
+	size_t buffer_len,
+	const char *buffer_as_path,
+	const git_diff_options *options,
+	git_diff_file_cb file_cb,
+	git_diff_binary_cb binary_cb,
+	git_diff_hunk_cb hunk_cb,
+	git_diff_line_cb line_cb,
+	void *payload);
+
+/**
+ * Directly run a diff between two buffers.
+ *
+ * Even more than with `git_diff_blobs`, comparing two buffer lacks
+ * context, so the `git_diff_file` parameters to the callbacks will be
+ * faked a la the rules for `git_diff_blobs()`.
+ *
+ * @param old_buffer Raw data for old side of diff, or NULL for empty
+ * @param old_len Length of the raw data for old side of the diff
+ * @param old_as_path Treat old buffer as if it had this filename; can be NULL
+ * @param new_buffer Raw data for new side of diff, or NULL for empty
+ * @param new_len Length of raw data for new side of diff
+ * @param new_as_path Treat buffer as if it had this filename; can be NULL
+ * @param options Options for diff, or NULL for default options
+ * @param file_cb Callback for "file"; made once if there is a diff; can be NULL
+ * @param binary_cb Callback for binary files; can be NULL
+ * @param hunk_cb Callback for each hunk in diff; can be NULL
+ * @param line_cb Callback for each line in diff; can be NULL
+ * @param payload Payload passed to each callback function
+ * @return 0 on success, non-zero callback return value, or error code
+ */
+GIT_EXTERN(int) git_diff_buffers(
+	const void *old_buffer,
+	size_t old_len,
+	const char *old_as_path,
+	const void *new_buffer,
+	size_t new_len,
+	const char *new_as_path,
+	const git_diff_options *options,
+	git_diff_file_cb file_cb,
+	git_diff_binary_cb binary_cb,
+	git_diff_hunk_cb hunk_cb,
+	git_diff_line_cb line_cb,
+	void *payload);
+
+/**
+ * Read the contents of a git patch file into a `git_diff` object.
+ *
+ * The diff object produced is similar to the one that would be
+ * produced if you actually produced it computationally by comparing
+ * two trees, however there may be subtle differences.  For example,
+ * a patch file likely contains abbreviated object IDs, so the
+ * object IDs in a `git_diff_delta` produced by this function will
+ * also be abbreviated.
+ *
+ * This function will only read patch files created by a git
+ * implementation, it will not read unified diffs produced by
+ * the `diff` program, nor any other types of patch files.
+ *
+ * @param out A pointer to a git_diff pointer that will be allocated.
+ * @param content The contents of a patch file
+ * @param content_len The length of the patch file contents
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_diff_from_buffer(
+	git_diff **out,
+	const char *content,
+	size_t content_len);
+
+/**
+ * This is an opaque structure which is allocated by `git_diff_get_stats`.
+ * You are responsible for releasing the object memory when done, using the
+ * `git_diff_stats_free()` function.
+ */
+typedef struct git_diff_stats git_diff_stats;
+
+/**
+ * Formatting options for diff stats
+ */
+typedef enum {
+	/** No stats*/
+	GIT_DIFF_STATS_NONE = 0,
+
+	/** Full statistics, equivalent of `--stat` */
+	GIT_DIFF_STATS_FULL = (1u << 0),
+
+	/** Short statistics, equivalent of `--shortstat` */
+	GIT_DIFF_STATS_SHORT = (1u << 1),
+
+	/** Number statistics, equivalent of `--numstat` */
+	GIT_DIFF_STATS_NUMBER = (1u << 2),
+
+	/** Extended header information such as creations, renames and mode changes, equivalent of `--summary` */
+	GIT_DIFF_STATS_INCLUDE_SUMMARY = (1u << 3),
+} git_diff_stats_format_t;
+
+/**
+ * Accumulate diff statistics for all patches.
+ *
+ * @param out Structure containg the diff statistics.
+ * @param diff A git_diff generated by one of the above functions.
+ * @return 0 on success; non-zero on error
+ */
+GIT_EXTERN(int) git_diff_get_stats(
+	git_diff_stats **out,
+	git_diff *diff);
+
+/**
+ * Get the total number of files changed in a diff
+ *
+ * @param stats A `git_diff_stats` generated by one of the above functions.
+ * @return total number of files changed in the diff
+ */
+GIT_EXTERN(size_t) git_diff_stats_files_changed(
+	const git_diff_stats *stats);
+
+/**
+ * Get the total number of insertions in a diff
+ *
+ * @param stats A `git_diff_stats` generated by one of the above functions.
+ * @return total number of insertions in the diff
+ */
+GIT_EXTERN(size_t) git_diff_stats_insertions(
+	const git_diff_stats *stats);
+
+/**
+ * Get the total number of deletions in a diff
+ *
+ * @param stats A `git_diff_stats` generated by one of the above functions.
+ * @return total number of deletions in the diff
+ */
+GIT_EXTERN(size_t) git_diff_stats_deletions(
+	const git_diff_stats *stats);
+
+/**
+ * Print diff statistics to a `git_buf`.
+ *
+ * @param out buffer to store the formatted diff statistics in.
+ * @param stats A `git_diff_stats` generated by one of the above functions.
+ * @param format Formatting option.
+ * @param width Target width for output (only affects GIT_DIFF_STATS_FULL)
+ * @return 0 on success; non-zero on error
+ */
+GIT_EXTERN(int) git_diff_stats_to_buf(
+	git_buf *out,
+	const git_diff_stats *stats,
+	git_diff_stats_format_t format,
+	size_t width);
+
+/**
+ * Deallocate a `git_diff_stats`.
+ *
+ * @param stats The previously created statistics object;
+ * cannot be used after free.
+ */
+GIT_EXTERN(void) git_diff_stats_free(git_diff_stats *stats);
+
+/**
+ * Formatting options for diff e-mail generation
+ */
+typedef enum {
+	/** Normal patch, the default */
+	GIT_DIFF_FORMAT_EMAIL_NONE = 0,
+
+	/** Don't insert "[PATCH]" in the subject header*/
+	GIT_DIFF_FORMAT_EMAIL_EXCLUDE_SUBJECT_PATCH_MARKER = (1 << 0),
+
+} git_diff_format_email_flags_t;
+
+/**
+ * Options for controlling the formatting of the generated e-mail.
+ */
+typedef struct {
+	unsigned int version;
+
+	git_diff_format_email_flags_t flags;
+
+	/** This patch number */
+	size_t patch_no;
+
+	/** Total number of patches in this series */
+	size_t total_patches;
+
+	/** id to use for the commit */
+	const git_oid *id;
+
+	/** Summary of the change */
+	const char *summary;
+
+	/** Commit message's body */
+	const char *body;
+
+	/** Author of the change */
+	const git_signature *author;
+} git_diff_format_email_options;
+
+#define GIT_DIFF_FORMAT_EMAIL_OPTIONS_VERSION 1
+#define GIT_DIFF_FORMAT_EMAIL_OPTIONS_INIT {GIT_DIFF_FORMAT_EMAIL_OPTIONS_VERSION, 0, 1, 1, NULL, NULL, NULL, NULL}
+
+/**
+ * Create an e-mail ready patch from a diff.
+ *
+ * @param out buffer to store the e-mail patch in
+ * @param diff containing the commit
+ * @param opts structure with options to influence content and formatting.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_diff_format_email(
+	git_buf *out,
+	git_diff *diff,
+	const git_diff_format_email_options *opts);
+
+/**
+ * Create an e-mail ready patch for a commit.
+ *
+ * Does not support creating patches for merge commits (yet).
+ *
+ * @param out buffer to store the e-mail patch in
+ * @param repo containing the commit
+ * @param commit pointer to up commit
+ * @param patch_no patch number of the commit
+ * @param total_patches total number of patches in the patch set
+ * @param flags determines the formatting of the e-mail
+ * @param diff_opts structure with options to influence diff or NULL for defaults.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_diff_commit_as_email(
+	git_buf *out,
+	git_repository *repo,
+	git_commit *commit,
+	size_t patch_no,
+	size_t total_patches,
+	git_diff_format_email_flags_t flags,
+	const git_diff_options *diff_opts);
+
+/**
+ * Initializes a `git_diff_format_email_options` with default values.
+ *
+ * Equivalent to creating an instance with GIT_DIFF_FORMAT_EMAIL_OPTIONS_INIT.
+ *
+ * @param opts The `git_diff_format_email_options` struct to initialize
+ * @param version Version of struct; pass `GIT_DIFF_FORMAT_EMAIL_OPTIONS_VERSION`
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_diff_format_email_init_options(
+	git_diff_format_email_options *opts,
+	unsigned int version);
+
+/**
+ * Patch ID options structure
+ *
+ * Initialize with `GIT_DIFF_PATCHID_OPTIONS_INIT` macro to
+ * correctly set the default values and version.
+ */
+typedef struct git_diff_patchid_options {
+	unsigned int version;
+} git_diff_patchid_options;
+
+#define GIT_DIFF_PATCHID_OPTIONS_VERSION 1
+#define GIT_DIFF_PATCHID_OPTIONS_INIT { GIT_DIFF_PATCHID_OPTIONS_VERSION }
+
+/**
+ * Initialize `git_diff_patchid_options` structure.
+ *
+ * Initializes the structure with default values. Equivalent to
+ * creating an instance with `GIT_DIFF_PATCHID_OPTIONS_INIT`.
+ */
+GIT_EXTERN(int) git_diff_patchid_init_options(
+	git_diff_patchid_options *opts,
+	unsigned int version);
+
+/**
+ * Calculate the patch ID for the given patch.
+ *
+ * Calculate a stable patch ID for the given patch by summing the
+ * hash of the file diffs, ignoring whitespace and line numbers.
+ * This can be used to derive whether two diffs are the same with
+ * a high probability.
+ *
+ * Currently, this function only calculates stable patch IDs, as
+ * defined in git-patch-id(1), and should in fact generate the
+ * same IDs as the upstream git project does.
+ *
+ * @param out Pointer where the calculated patch ID shoul be
+ *  stored
+ * @param diff The diff to calculate the ID for
+ * @param opts Options for how to calculate the patch ID. This is
+ *  intended for future changes, as currently no options are
+ *  available.
+ * @return 0 on success, an error code otherwise.
+ */
+GIT_EXTERN(int) git_diff_patchid(git_oid *out, git_diff *diff, git_diff_patchid_options *opts);
+
+GIT_END_DECL
+
+/** @} */
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/errors.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/errors.h b/vendor/libgit2-sys/libgit2/include/git2/errors.h
new file mode 100644
index 0000000..6f55802
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/errors.h
@@ -0,0 +1,153 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_errors_h__
+#define INCLUDE_git_errors_h__
+
+#include "common.h"
+
+/**
+ * @file git2/errors.h
+ * @brief Git error handling routines and variables
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/** Generic return codes */
+typedef enum {
+	GIT_OK         =  0,		/**< No error */
+
+	GIT_ERROR      = -1,		/**< Generic error */
+	GIT_ENOTFOUND  = -3,		/**< Requested object could not be found */
+	GIT_EEXISTS    = -4,		/**< Object exists preventing operation */
+	GIT_EAMBIGUOUS = -5,		/**< More than one object matches */
+	GIT_EBUFS      = -6,		/**< Output buffer too short to hold data */
+
+	/* GIT_EUSER is a special error that is never generated by libgit2
+	 * code.  You can return it from a callback (e.g to stop an iteration)
+	 * to know that it was generated by the callback and not by libgit2.
+	 */
+	GIT_EUSER      = -7,
+
+	GIT_EBAREREPO       =  -8,	/**< Operation not allowed on bare repository */
+	GIT_EUNBORNBRANCH   =  -9,	/**< HEAD refers to branch with no commits */
+	GIT_EUNMERGED       = -10,	/**< Merge in progress prevented operation */
+	GIT_ENONFASTFORWARD = -11,	/**< Reference was not fast-forwardable */
+	GIT_EINVALIDSPEC    = -12,	/**< Name/ref spec was not in a valid format */
+	GIT_ECONFLICT       = -13,	/**< Checkout conflicts prevented operation */
+	GIT_ELOCKED         = -14,	/**< Lock file prevented operation */
+	GIT_EMODIFIED       = -15,	/**< Reference value does not match expected */
+	GIT_EAUTH           = -16,      /**< Authentication error */
+	GIT_ECERTIFICATE    = -17,      /**< Server certificate is invalid */
+	GIT_EAPPLIED        = -18,	/**< Patch/merge has already been applied */
+	GIT_EPEEL           = -19,      /**< The requested peel operation is not possible */
+	GIT_EEOF            = -20,      /**< Unexpected EOF */
+	GIT_EINVALID        = -21,      /**< Invalid operation or input */
+	GIT_EUNCOMMITTED    = -22,	/**< Uncommitted changes in index prevented operation */
+	GIT_EDIRECTORY      = -23,      /**< The operation is not valid for a directory */
+	GIT_EMERGECONFLICT  = -24,	/**< A merge conflict exists and cannot continue */
+
+	GIT_PASSTHROUGH     = -30,	/**< Internal only */
+	GIT_ITEROVER        = -31,	/**< Signals end of iteration with iterator */
+	GIT_RETRY           = -32,	/**< Internal only */
+	GIT_EMISMATCH       = -33,	/**< Hashsum mismatch in object */
+} git_error_code;
+
+/**
+ * Structure to store extra details of the last error that occurred.
+ *
+ * This is kept on a per-thread basis if GIT_THREADS was defined when the
+ * library was build, otherwise one is kept globally for the library
+ */
+typedef struct {
+	char *message;
+	int klass;
+} git_error;
+
+/** Error classes */
+typedef enum {
+	GITERR_NONE = 0,
+	GITERR_NOMEMORY,
+	GITERR_OS,
+	GITERR_INVALID,
+	GITERR_REFERENCE,
+	GITERR_ZLIB,
+	GITERR_REPOSITORY,
+	GITERR_CONFIG,
+	GITERR_REGEX,
+	GITERR_ODB,
+	GITERR_INDEX,
+	GITERR_OBJECT,
+	GITERR_NET,
+	GITERR_TAG,
+	GITERR_TREE,
+	GITERR_INDEXER,
+	GITERR_SSL,
+	GITERR_SUBMODULE,
+	GITERR_THREAD,
+	GITERR_STASH,
+	GITERR_CHECKOUT,
+	GITERR_FETCHHEAD,
+	GITERR_MERGE,
+	GITERR_SSH,
+	GITERR_FILTER,
+	GITERR_REVERT,
+	GITERR_CALLBACK,
+	GITERR_CHERRYPICK,
+	GITERR_DESCRIBE,
+	GITERR_REBASE,
+	GITERR_FILESYSTEM,
+	GITERR_PATCH,
+	GITERR_WORKTREE,
+	GITERR_SHA1
+} git_error_t;
+
+/**
+ * Return the last `git_error` object that was generated for the
+ * current thread or NULL if no error has occurred.
+ *
+ * @return A git_error object.
+ */
+GIT_EXTERN(const git_error *) giterr_last(void);
+
+/**
+ * Clear the last library error that occurred for this thread.
+ */
+GIT_EXTERN(void) giterr_clear(void);
+
+/**
+ * Set the error message string for this thread.
+ *
+ * This function is public so that custom ODB backends and the like can
+ * relay an error message through libgit2.  Most regular users of libgit2
+ * will never need to call this function -- actually, calling it in most
+ * circumstances (for example, calling from within a callback function)
+ * will just end up having the value overwritten by libgit2 internals.
+ *
+ * This error message is stored in thread-local storage and only applies
+ * to the particular thread that this libgit2 call is made from.
+ *
+ * @param error_class One of the `git_error_t` enum above describing the
+ *                    general subsystem that is responsible for the error.
+ * @param string The formatted error message to keep
+ */
+GIT_EXTERN(void) giterr_set_str(int error_class, const char *string);
+
+/**
+ * Set the error message to a special value for memory allocation failure.
+ *
+ * The normal `giterr_set_str()` function attempts to `strdup()` the string
+ * that is passed in.  This is not a good idea when the error in question
+ * is a memory allocation failure.  That circumstance has a special setter
+ * function that sets the error string to a known and statically allocated
+ * internal value.
+ */
+GIT_EXTERN(void) giterr_set_oom(void);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/filter.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/filter.h b/vendor/libgit2-sys/libgit2/include/git2/filter.h
new file mode 100644
index 0000000..436a0f3
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/filter.h
@@ -0,0 +1,217 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_filter_h__
+#define INCLUDE_git_filter_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+#include "buffer.h"
+
+/**
+ * @file git2/filter.h
+ * @brief Git filter APIs
+ *
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Filters are applied in one of two directions: smudging - which is
+ * exporting a file from the Git object database to the working directory,
+ * and cleaning - which is importing a file from the working directory to
+ * the Git object database.  These values control which direction of
+ * change is being applied.
+ */
+typedef enum {
+	GIT_FILTER_TO_WORKTREE = 0,
+	GIT_FILTER_SMUDGE = GIT_FILTER_TO_WORKTREE,
+	GIT_FILTER_TO_ODB = 1,
+	GIT_FILTER_CLEAN = GIT_FILTER_TO_ODB,
+} git_filter_mode_t;
+
+/**
+ * Filter option flags.
+ */
+typedef enum {
+	GIT_FILTER_DEFAULT = 0u,
+	GIT_FILTER_ALLOW_UNSAFE = (1u << 0),
+} git_filter_flag_t;
+
+/**
+ * A filter that can transform file data
+ *
+ * This represents a filter that can be used to transform or even replace
+ * file data.  Libgit2 includes one built in filter and it is possible to
+ * write your own (see git2/sys/filter.h for information on that).
+ *
+ * The two builtin filters are:
+ *
+ * * "crlf" which uses the complex rules with the "text", "eol", and
+ *   "crlf" file attributes to decide how to convert between LF and CRLF
+ *   line endings
+ * * "ident" which replaces "$Id$" in a blob with "$Id: <blob OID>$" upon
+ *   checkout and replaced "$Id: <anything>$" with "$Id$" on checkin.
+ */
+typedef struct git_filter git_filter;
+
+/**
+ * List of filters to be applied
+ *
+ * This represents a list of filters to be applied to a file / blob.  You
+ * can build the list with one call, apply it with another, and dispose it
+ * with a third.  In typical usage, there are not many occasions where a
+ * git_filter_list is needed directly since the library will generally
+ * handle conversions for you, but it can be convenient to be able to
+ * build and apply the list sometimes.
+ */
+typedef struct git_filter_list git_filter_list;
+
+/**
+ * Load the filter list for a given path.
+ *
+ * This will return 0 (success) but set the output git_filter_list to NULL
+ * if no filters are requested for the given file.
+ *
+ * @param filters Output newly created git_filter_list (or NULL)
+ * @param repo Repository object that contains `path`
+ * @param blob The blob to which the filter will be applied (if known)
+ * @param path Relative path of the file to be filtered
+ * @param mode Filtering direction (WT->ODB or ODB->WT)
+ * @param flags Combination of `git_filter_flag_t` flags
+ * @return 0 on success (which could still return NULL if no filters are
+ *         needed for the requested file), <0 on error
+ */
+GIT_EXTERN(int) git_filter_list_load(
+	git_filter_list **filters,
+	git_repository *repo,
+	git_blob *blob, /* can be NULL */
+	const char *path,
+	git_filter_mode_t mode,
+	uint32_t flags);
+
+/**
+ * Query the filter list to see if a given filter (by name) will run.
+ * The built-in filters "crlf" and "ident" can be queried, otherwise this
+ * is the name of the filter specified by the filter attribute.
+ *
+ * This will return 0 if the given filter is not in the list, or 1 if
+ * the filter will be applied.
+ *
+ * @param filters A loaded git_filter_list (or NULL)
+ * @param name The name of the filter to query
+ * @return 1 if the filter is in the list, 0 otherwise
+ */
+GIT_EXTERN(int) git_filter_list_contains(
+	git_filter_list *filters,
+	const char *name);
+
+/**
+ * Apply filter list to a data buffer.
+ *
+ * See `git2/buffer.h` for background on `git_buf` objects.
+ *
+ * If the `in` buffer holds data allocated by libgit2 (i.e. `in->asize` is
+ * not zero), then it will be overwritten when applying the filters.  If
+ * not, then it will be left untouched.
+ *
+ * If there are no filters to apply (or `filters` is NULL), then the `out`
+ * buffer will reference the `in` buffer data (with `asize` set to zero)
+ * instead of allocating data.  This keeps allocations to a minimum, but
+ * it means you have to be careful about freeing the `in` data since `out`
+ * may be pointing to it!
+ *
+ * @param out Buffer to store the result of the filtering
+ * @param filters A loaded git_filter_list (or NULL)
+ * @param in Buffer containing the data to filter
+ * @return 0 on success, an error code otherwise
+ */
+GIT_EXTERN(int) git_filter_list_apply_to_data(
+	git_buf *out,
+	git_filter_list *filters,
+	git_buf *in);
+
+/**
+ * Apply a filter list to the contents of a file on disk
+ *
+ * @param out buffer into which to store the filtered file
+ * @param filters the list of filters to apply
+ * @param repo the repository in which to perform the filtering
+ * @param path the path of the file to filter, a relative path will be
+ * taken as relative to the workdir
+ */
+GIT_EXTERN(int) git_filter_list_apply_to_file(
+	git_buf *out,
+	git_filter_list *filters,
+	git_repository *repo,
+	const char *path);
+
+/**
+ * Apply a filter list to the contents of a blob
+ *
+ * @param out buffer into which to store the filtered file
+ * @param filters the list of filters to apply
+ * @param blob the blob to filter
+ */
+GIT_EXTERN(int) git_filter_list_apply_to_blob(
+	git_buf *out,
+	git_filter_list *filters,
+	git_blob *blob);
+
+/**
+ * Apply a filter list to an arbitrary buffer as a stream
+ *
+ * @param filters the list of filters to apply
+ * @param data the buffer to filter
+ * @param target the stream into which the data will be written
+ */
+GIT_EXTERN(int) git_filter_list_stream_data(
+	git_filter_list *filters,
+	git_buf *data,
+	git_writestream *target);
+
+/**
+ * Apply a filter list to a file as a stream
+ *
+ * @param filters the list of filters to apply
+ * @param repo the repository in which to perform the filtering
+ * @param path the path of the file to filter, a relative path will be
+ * taken as relative to the workdir
+ * @param target the stream into which the data will be written
+ */
+GIT_EXTERN(int) git_filter_list_stream_file(
+	git_filter_list *filters,
+	git_repository *repo,
+	const char *path,
+	git_writestream *target);
+
+/**
+ * Apply a filter list to a blob as a stream
+ *
+ * @param filters the list of filters to apply
+ * @param blob the blob to filter
+ * @param target the stream into which the data will be written
+ */
+GIT_EXTERN(int) git_filter_list_stream_blob(
+	git_filter_list *filters,
+	git_blob *blob,
+	git_writestream *target);
+
+/**
+ * Free a git_filter_list
+ *
+ * @param filters A git_filter_list created by `git_filter_list_load`
+ */
+GIT_EXTERN(void) git_filter_list_free(git_filter_list *filters);
+
+
+GIT_END_DECL
+
+/** @} */
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/global.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/global.h b/vendor/libgit2-sys/libgit2/include/git2/global.h
new file mode 100644
index 0000000..2a87e10
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/global.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_global_h__
+#define INCLUDE_git_global_h__
+
+#include "common.h"
+
+GIT_BEGIN_DECL
+
+/**
+ * Init the global state
+ *
+ * This function must be called before any other libgit2 function in
+ * order to set up global state and threading.
+ *
+ * This function may be called multiple times - it will return the number
+ * of times the initialization has been called (including this one) that have
+ * not subsequently been shutdown.
+ *
+ * @return the number of initializations of the library, or an error code.
+ */
+GIT_EXTERN(int) git_libgit2_init(void);
+
+/**
+ * Shutdown the global state
+ *
+ * Clean up the global state and threading context after calling it as
+ * many times as `git_libgit2_init()` was called - it will return the
+ * number of remainining initializations that have not been shutdown
+ * (after this one).
+ * 
+ * @return the number of remaining initializations of the library, or an
+ * error code.
+ */
+GIT_EXTERN(int) git_libgit2_shutdown(void);
+
+/** @} */
+GIT_END_DECL
+#endif
+

vendor/libgit2-sys/libgit2/include/git2/graph.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/graph.h b/vendor/libgit2-sys/libgit2/include/git2/graph.h
new file mode 100644
index 0000000..213ae97
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/graph.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_graph_h__
+#define INCLUDE_git_graph_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+
+/**
+ * @file git2/graph.h
+ * @brief Git graph traversal routines
+ * @defgroup git_revwalk Git graph traversal routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Count the number of unique commits between two commit objects
+ *
+ * There is no need for branches containing the commits to have any
+ * upstream relationship, but it helps to think of one as a branch and
+ * the other as its upstream, the `ahead` and `behind` values will be
+ * what git would report for the branches.
+ *
+ * @param ahead number of unique from commits in `upstream`
+ * @param behind number of unique from commits in `local`
+ * @param repo the repository where the commits exist
+ * @param local the commit for local
+ * @param upstream the commit for upstream
+ */
+GIT_EXTERN(int) git_graph_ahead_behind(size_t *ahead, size_t *behind, git_repository *repo, const git_oid *local, const git_oid *upstream);
+
+
+/**
+ * Determine if a commit is the descendant of another commit.
+ *
+ * Note that a commit is not considered a descendant of itself, in contrast
+ * to `git merge-base --is-ancestor`.
+ *
+ * @param commit a previously loaded commit.
+ * @param ancestor a potential ancestor commit.
+ * @return 1 if the given commit is a descendant of the potential ancestor,
+ * 0 if not, error code otherwise.
+ */
+GIT_EXTERN(int) git_graph_descendant_of(
+	git_repository *repo,
+	const git_oid *commit,
+	const git_oid *ancestor);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/ignore.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/ignore.h b/vendor/libgit2-sys/libgit2/include/git2/ignore.h
new file mode 100644
index 0000000..d0c1877
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/ignore.h
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_ignore_h__
+#define INCLUDE_git_ignore_h__
+
+#include "common.h"
+#include "types.h"
+
+GIT_BEGIN_DECL
+
+/**
+ * Add ignore rules for a repository.
+ *
+ * Excludesfile rules (i.e. .gitignore rules) are generally read from
+ * .gitignore files in the repository tree or from a shared system file
+ * only if a "core.excludesfile" config value is set.  The library also
+ * keeps a set of per-repository internal ignores that can be configured
+ * in-memory and will not persist.  This function allows you to add to
+ * that internal rules list.
+ *
+ * Example usage:
+ *
+ *     error = git_ignore_add_rule(myrepo, "*.c\ndir/\nFile with space\n");
+ *
+ * This would add three rules to the ignores.
+ *
+ * @param repo The repository to add ignore rules to.
+ * @param rules Text of rules, a la the contents of a .gitignore file.
+ *              It is okay to have multiple rules in the text; if so,
+ *              each rule should be terminated with a newline.
+ * @return 0 on success
+ */
+GIT_EXTERN(int) git_ignore_add_rule(
+	git_repository *repo,
+	const char *rules);
+
+/**
+ * Clear ignore rules that were explicitly added.
+ *
+ * Resets to the default internal ignore rules.  This will not turn off
+ * rules in .gitignore files that actually exist in the filesystem.
+ *
+ * The default internal ignores ignore ".", ".." and ".git" entries.
+ *
+ * @param repo The repository to remove ignore rules from.
+ * @return 0 on success
+ */
+GIT_EXTERN(int) git_ignore_clear_internal_rules(
+	git_repository *repo);
+
+/**
+ * Test if the ignore rules apply to a given path.
+ *
+ * This function checks the ignore rules to see if they would apply to the
+ * given file.  This indicates if the file would be ignored regardless of
+ * whether the file is already in the index or committed to the repository.
+ *
+ * One way to think of this is if you were to do "git add ." on the
+ * directory containing the file, would it be added or not?
+ *
+ * @param ignored boolean returning 0 if the file is not ignored, 1 if it is
+ * @param repo a repository object
+ * @param path the file to check ignores for, relative to the repo's workdir.
+ * @return 0 if ignore rules could be processed for the file (regardless
+ *         of whether it exists or not), or an error < 0 if they could not.
+ */
+GIT_EXTERN(int) git_ignore_path_is_ignored(
+	int *ignored,
+	git_repository *repo,
+	const char *path);
+
+GIT_END_DECL
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/index.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/index.h b/vendor/libgit2-sys/libgit2/include/git2/index.h
new file mode 100644
index 0000000..35af2e5
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/index.h
@@ -0,0 +1,812 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_index_h__
+#define INCLUDE_git_index_h__
+
+#include "common.h"
+#include "indexer.h"
+#include "types.h"
+#include "oid.h"
+#include "strarray.h"
+
+/**
+ * @file git2/index.h
+ * @brief Git index parsing and manipulation routines
+ * @defgroup git_index Git index parsing and manipulation routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/** Time structure used in a git index entry */
+typedef struct {
+	int32_t seconds;
+	/* nsec should not be stored as time_t compatible */
+	uint32_t nanoseconds;
+} git_index_time;
+
+/**
+ * In-memory representation of a file entry in the index.
+ *
+ * This is a public structure that represents a file entry in the index.
+ * The meaning of the fields corresponds to core Git's documentation (in
+ * "Documentation/technical/index-format.txt").
+ *
+ * The `flags` field consists of a number of bit fields which can be
+ * accessed via the first set of `GIT_IDXENTRY_...` bitmasks below.  These
+ * flags are all read from and persisted to disk.
+ *
+ * The `flags_extended` field also has a number of bit fields which can be
+ * accessed via the later `GIT_IDXENTRY_...` bitmasks below.  Some of
+ * these flags are read from and written to disk, but some are set aside
+ * for in-memory only reference.
+ *
+ * Note that the time and size fields are truncated to 32 bits. This
+ * is enough to detect changes, which is enough for the index to
+ * function as a cache, but it should not be taken as an authoritative
+ * source for that data.
+ */
+typedef struct git_index_entry {
+	git_index_time ctime;
+	git_index_time mtime;
+
+	uint32_t dev;
+	uint32_t ino;
+	uint32_t mode;
+	uint32_t uid;
+	uint32_t gid;
+	uint32_t file_size;
+
+	git_oid id;
+
+	uint16_t flags;
+	uint16_t flags_extended;
+
+	const char *path;
+} git_index_entry;
+
+/**
+ * Bitmasks for on-disk fields of `git_index_entry`'s `flags`
+ *
+ * These bitmasks match the four fields in the `git_index_entry` `flags`
+ * value both in memory and on disk.  You can use them to interpret the
+ * data in the `flags`.
+ */
+#define GIT_IDXENTRY_NAMEMASK  (0x0fff)
+#define GIT_IDXENTRY_STAGEMASK (0x3000)
+#define GIT_IDXENTRY_STAGESHIFT 12
+
+/**
+ * Flags for index entries
+ */
+typedef enum {
+	GIT_IDXENTRY_EXTENDED  = (0x4000),
+	GIT_IDXENTRY_VALID     = (0x8000),
+} git_indxentry_flag_t;
+
+#define GIT_IDXENTRY_STAGE(E) \
+	(((E)->flags & GIT_IDXENTRY_STAGEMASK) >> GIT_IDXENTRY_STAGESHIFT)
+
+#define GIT_IDXENTRY_STAGE_SET(E,S) do { \
+	(E)->flags = ((E)->flags & ~GIT_IDXENTRY_STAGEMASK) | \
+		(((S) & 0x03) << GIT_IDXENTRY_STAGESHIFT); } while (0)
+
+/**
+ * Bitmasks for on-disk fields of `git_index_entry`'s `flags_extended`
+ *
+ * In memory, the `flags_extended` fields are divided into two parts: the
+ * fields that are read from and written to disk, and other fields that
+ * in-memory only and used by libgit2.  Only the flags in
+ * `GIT_IDXENTRY_EXTENDED_FLAGS` will get saved on-disk.
+ *
+ * Thee first three bitmasks match the three fields in the
+ * `git_index_entry` `flags_extended` value that belong on disk.  You
+ * can use them to interpret the data in the `flags_extended`.
+ *
+ * The rest of the bitmasks match the other fields in the `git_index_entry`
+ * `flags_extended` value that are only used in-memory by libgit2.
+ * You can use them to interpret the data in the `flags_extended`.
+ *
+ */
+typedef enum {
+
+	GIT_IDXENTRY_INTENT_TO_ADD  =  (1 << 13),
+	GIT_IDXENTRY_SKIP_WORKTREE  =  (1 << 14),
+	/** Reserved for future extension */
+	GIT_IDXENTRY_EXTENDED2      =  (1 << 15),
+
+	GIT_IDXENTRY_EXTENDED_FLAGS = (GIT_IDXENTRY_INTENT_TO_ADD | GIT_IDXENTRY_SKIP_WORKTREE),
+	GIT_IDXENTRY_UPDATE            =  (1 << 0),
+	GIT_IDXENTRY_REMOVE            =  (1 << 1),
+	GIT_IDXENTRY_UPTODATE          =  (1 << 2),
+	GIT_IDXENTRY_ADDED             =  (1 << 3),
+
+	GIT_IDXENTRY_HASHED            =  (1 << 4),
+	GIT_IDXENTRY_UNHASHED          =  (1 << 5),
+	GIT_IDXENTRY_WT_REMOVE         =  (1 << 6), /**< remove in work directory */
+	GIT_IDXENTRY_CONFLICTED        =  (1 << 7),
+
+	GIT_IDXENTRY_UNPACKED          =  (1 << 8),
+	GIT_IDXENTRY_NEW_SKIP_WORKTREE =  (1 << 9),
+} git_idxentry_extended_flag_t;
+
+/** Capabilities of system that affect index actions. */
+typedef enum {
+	GIT_INDEXCAP_IGNORE_CASE = 1,
+	GIT_INDEXCAP_NO_FILEMODE = 2,
+	GIT_INDEXCAP_NO_SYMLINKS = 4,
+	GIT_INDEXCAP_FROM_OWNER  = -1,
+} git_indexcap_t;
+
+/** Callback for APIs that add/remove/update files matching pathspec */
+typedef int (*git_index_matched_path_cb)(
+	const char *path, const char *matched_pathspec, void *payload);
+
+/** Flags for APIs that add files matching pathspec */
+typedef enum {
+	GIT_INDEX_ADD_DEFAULT = 0,
+	GIT_INDEX_ADD_FORCE = (1u << 0),
+	GIT_INDEX_ADD_DISABLE_PATHSPEC_MATCH = (1u << 1),
+	GIT_INDEX_ADD_CHECK_PATHSPEC = (1u << 2),
+} git_index_add_option_t;
+
+typedef enum {
+	/**
+	 * Match any index stage.
+	 *
+	 * Some index APIs take a stage to match; pass this value to match
+	 * any entry matching the path regardless of stage.
+	 */
+	GIT_INDEX_STAGE_ANY = -1,
+
+	/** A normal staged file in the index. */
+	GIT_INDEX_STAGE_NORMAL = 0,
+
+	/** The ancestor side of a conflict. */
+	GIT_INDEX_STAGE_ANCESTOR = 1,
+
+	/** The "ours" side of a conflict. */
+	GIT_INDEX_STAGE_OURS = 2,
+
+	/** The "theirs" side of a conflict. */
+	GIT_INDEX_STAGE_THEIRS = 3,
+} git_index_stage_t;
+
+/** @name Index File Functions
+ *
+ * These functions work on the index file itself.
+ */
+/**@{*/
+
+/**
+ * Create a new bare Git index object as a memory representation
+ * of the Git index file in 'index_path', without a repository
+ * to back it.
+ *
+ * Since there is no ODB or working directory behind this index,
+ * any Index methods which rely on these (e.g. index_add_bypath)
+ * will fail with the GIT_ERROR error code.
+ *
+ * If you need to access the index of an actual repository,
+ * use the `git_repository_index` wrapper.
+ *
+ * The index must be freed once it's no longer in use.
+ *
+ * @param out the pointer for the new index
+ * @param index_path the path to the index file in disk
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_index_open(git_index **out, const char *index_path);
+
+/**
+ * Create an in-memory index object.
+ *
+ * This index object cannot be read/written to the filesystem,
+ * but may be used to perform in-memory index operations.
+ *
+ * The index must be freed once it's no longer in use.
+ *
+ * @param out the pointer for the new index
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_index_new(git_index **out);
+
+/**
+ * Free an existing index object.
+ *
+ * @param index an existing index object
+ */
+GIT_EXTERN(void) git_index_free(git_index *index);
+
+/**
+ * Get the repository this index relates to
+ *
+ * @param index The index
+ * @return A pointer to the repository
+ */
+GIT_EXTERN(git_repository *) git_index_owner(const git_index *index);
+
+/**
+ * Read index capabilities flags.
+ *
+ * @param index An existing index object
+ * @return A combination of GIT_INDEXCAP values
+ */
+GIT_EXTERN(int) git_index_caps(const git_index *index);
+
+/**
+ * Set index capabilities flags.
+ *
+ * If you pass `GIT_INDEXCAP_FROM_OWNER` for the caps, then the
+ * capabilities will be read from the config of the owner object,
+ * looking at `core.ignorecase`, `core.filemode`, `core.symlinks`.
+ *
+ * @param index An existing index object
+ * @param caps A combination of GIT_INDEXCAP values
+ * @return 0 on success, -1 on failure
+ */
+GIT_EXTERN(int) git_index_set_caps(git_index *index, int caps);
+
+/**
+ * Get index on-disk version.
+ *
+ * Valid return values are 2, 3, or 4.  If 3 is returned, an index
+ * with version 2 may be written instead, if the extension data in
+ * version 3 is not necessary.
+ *
+ * @param index An existing index object
+ * @return the index version
+ */
+GIT_EXTERN(unsigned int) git_index_version(git_index *index);
+
+/**
+ * Set index on-disk version.
+ *
+ * Valid values are 2, 3, or 4.  If 2 is given, git_index_write may
+ * write an index with version 3 instead, if necessary to accurately
+ * represent the index.
+ *
+ * @param index An existing index object
+ * @param version The new version number
+ * @return 0 on success, -1 on failure
+ */
+GIT_EXTERN(int) git_index_set_version(git_index *index, unsigned int version);
+
+/**
+ * Update the contents of an existing index object in memory by reading
+ * from the hard disk.
+ *
+ * If `force` is true, this performs a "hard" read that discards in-memory
+ * changes and always reloads the on-disk index data.  If there is no
+ * on-disk version, the index will be cleared.
+ *
+ * If `force` is false, this does a "soft" read that reloads the index
+ * data from disk only if it has changed since the last time it was
+ * loaded.  Purely in-memory index data will be untouched.  Be aware: if
+ * there are changes on disk, unwritten in-memory changes are discarded.
+ *
+ * @param index an existing index object
+ * @param force if true, always reload, vs. only read if file has changed
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_index_read(git_index *index, int force);
+
+/**
+ * Write an existing index object from memory back to disk
+ * using an atomic file lock.
+ *
+ * @param index an existing index object
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_index_write(git_index *index);
+
+/**
+ * Get the full path to the index file on disk.
+ *
+ * @param index an existing index object
+ * @return path to index file or NULL for in-memory index
+ */
+GIT_EXTERN(const char *) git_index_path(const git_index *index);
+
+/**
+ * Get the checksum of the index
+ *
+ * This checksum is the SHA-1 hash over the index file (except the
+ * last 20 bytes which are the checksum itself). In cases where the
+ * index does not exist on-disk, it will be zeroed out.
+ *
+ * @param index an existing index object
+ * @return a pointer to the checksum of the index
+ */
+GIT_EXTERN(const git_oid *) git_index_checksum(git_index *index);
+
+/**
+ * Read a tree into the index file with stats
+ *
+ * The current index contents will be replaced by the specified tree.
+ *
+ * @param index an existing index object
+ * @param tree tree to read
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_index_read_tree(git_index *index, const git_tree *tree);
+
+/**
+ * Write the index as a tree
+ *
+ * This method will scan the index and write a representation
+ * of its current state back to disk; it recursively creates
+ * tree objects for each of the subtrees stored in the index,
+ * but only returns the OID of the root tree. This is the OID
+ * that can be used e.g. to create a commit.
+ *
+ * The index instance cannot be bare, and needs to be associated
+ * to an existing repository.
+ *
+ * The index must not contain any file in conflict.
+ *
+ * @param out Pointer where to store the OID of the written tree
+ * @param index Index to write
+ * @return 0 on success, GIT_EUNMERGED when the index is not clean
+ * or an error code
+ */
+GIT_EXTERN(int) git_index_write_tree(git_oid *out, git_index *index);
+
+/**
+ * Write the index as a tree to the given repository
+ *
+ * This method will do the same as `git_index_write_tree`, but
+ * letting the user choose the repository where the tree will
+ * be written.
+ *
+ * The index must not contain any file in conflict.
+ *
+ * @param out Pointer where to store OID of the the written tree
+ * @param index Index to write
+ * @param repo Repository where to write the tree
+ * @return 0 on success, GIT_EUNMERGED when the index is not clean
+ * or an error code
+ */
+GIT_EXTERN(int) git_index_write_tree_to(git_oid *out, git_index *index, git_repository *repo);
+
+/**@}*/
+
+/** @name Raw Index Entry Functions
+ *
+ * These functions work on index entries, and allow for raw manipulation
+ * of the entries.
+ */
+/**@{*/
+
+/* Index entry manipulation */
+
+/**
+ * Get the count of entries currently in the index
+ *
+ * @param index an existing index object
+ * @return integer of count of current entries
+ */
+GIT_EXTERN(size_t) git_index_entrycount(const git_index *index);
+
+/**
+ * Clear the contents (all the entries) of an index object.
+ *
+ * This clears the index object in memory; changes must be explicitly
+ * written to disk for them to take effect persistently.
+ *
+ * @param index an existing index object
+ * @return 0 on success, error code < 0 on failure
+ */
+GIT_EXTERN(int) git_index_clear(git_index *index);
+
+/**
+ * Get a pointer to one of the entries in the index
+ *
+ * The entry is not modifiable and should not be freed.  Because the
+ * `git_index_entry` struct is a publicly defined struct, you should
+ * be able to make your own permanent copy of the data if necessary.
+ *
+ * @param index an existing index object
+ * @param n the position of the entry
+ * @return a pointer to the entry; NULL if out of bounds
+ */
+GIT_EXTERN(const git_index_entry *) git_index_get_byindex(
+	git_index *index, size_t n);
+
+/**
+ * Get a pointer to one of the entries in the index
+ *
+ * The entry is not modifiable and should not be freed.  Because the
+ * `git_index_entry` struct is a publicly defined struct, you should
+ * be able to make your own permanent copy of the data if necessary.
+ *
+ * @param index an existing index object
+ * @param path path to search
+ * @param stage stage to search
+ * @return a pointer to the entry; NULL if it was not found
+ */
+GIT_EXTERN(const git_index_entry *) git_index_get_bypath(
+	git_index *index, const char *path, int stage);
+
+/**
+ * Remove an entry from the index
+ *
+ * @param index an existing index object
+ * @param path path to search
+ * @param stage stage to search
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_index_remove(git_index *index, const char *path, int stage);
+
+/**
+ * Remove all entries from the index under a given directory
+ *
+ * @param index an existing index object
+ * @param dir container directory path
+ * @param stage stage to search
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_index_remove_directory(
+	git_index *index, const char *dir, int stage);
+
+/**
+ * Add or update an index entry from an in-memory struct
+ *
+ * If a previous index entry exists that has the same path and stage
+ * as the given 'source_entry', it will be replaced.  Otherwise, the
+ * 'source_entry' will be added.
+ *
+ * A full copy (including the 'path' string) of the given
+ * 'source_entry' will be inserted on the index.
+ *
+ * @param index an existing index object
+ * @param source_entry new entry object
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_index_add(git_index *index, const git_index_entry *source_entry);
+
+/**
+ * Return the stage number from a git index entry
+ *
+ * This entry is calculated from the entry's flag attribute like this:
+ *
+ *    (entry->flags & GIT_IDXENTRY_STAGEMASK) >> GIT_IDXENTRY_STAGESHIFT
+ *
+ * @param entry The entry
+ * @return the stage number
+ */
+GIT_EXTERN(int) git_index_entry_stage(const git_index_entry *entry);
+
+/**
+ * Return whether the given index entry is a conflict (has a high stage
+ * entry).  This is simply shorthand for `git_index_entry_stage > 0`.
+ *
+ * @param entry The entry
+ * @return 1 if the entry is a conflict entry, 0 otherwise
+ */
+GIT_EXTERN(int) git_index_entry_is_conflict(const git_index_entry *entry);
+
+/**@}*/
+
+/** @name Workdir Index Entry Functions
+ *
+ * These functions work on index entries specifically in the working
+ * directory (ie, stage 0).
+ */
+/**@{*/
+
+/**
+ * Add or update an index entry from a file on disk
+ *
+ * The file `path` must be relative to the repository's
+ * working folder and must be readable.
+ *
+ * This method will fail in bare index instances.
+ *
+ * This forces the file to be added to the index, not looking
+ * at gitignore rules.  Those rules can be evaluated through
+ * the git_status APIs (in status.h) before calling this.
+ *
+ * If this file currently is the result of a merge conflict, this
+ * file will no longer be marked as conflicting.  The data about
+ * the conflict will be moved to the "resolve undo" (REUC) section.
+ *
+ * @param index an existing index object
+ * @param path filename to add
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_index_add_bypath(git_index *index, const char *path);
+
+/**
+ * Add or update an index entry from a buffer in memory
+ *
+ * This method will create a blob in the repository that owns the
+ * index and then add the index entry to the index.  The `path` of the
+ * entry represents the position of the blob relative to the
+ * repository's root folder.
+ *
+ * If a previous index entry exists that has the same path as the
+ * given 'entry', it will be replaced.  Otherwise, the 'entry' will be
+ * added. The `id` and the `file_size` of the 'entry' are updated with the
+ * real value of the blob.
+ *
+ * This forces the file to be added to the index, not looking
+ * at gitignore rules.  Those rules can be evaluated through
+ * the git_status APIs (in status.h) before calling this.
+ *
+ * If this file currently is the result of a merge conflict, this
+ * file will no longer be marked as conflicting.  The data about
+ * the conflict will be moved to the "resolve undo" (REUC) section.
+ *
+ * @param index an existing index object
+ * @param entry filename to add
+ * @param buffer data to be written into the blob
+ * @param len length of the data
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_index_add_frombuffer(
+	git_index *index,
+	const git_index_entry *entry,
+	const void *buffer, size_t len);
+
+/**
+ * Remove an index entry corresponding to a file on disk
+ *
+ * The file `path` must be relative to the repository's
+ * working folder.  It may exist.
+ *
+ * If this file currently is the result of a merge conflict, this
+ * file will no longer be marked as conflicting.  The data about
+ * the conflict will be moved to the "resolve undo" (REUC) section.
+ *
+ * @param index an existing index object
+ * @param path filename to remove
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_index_remove_bypath(git_index *index, const char *path);
+
+/**
+ * Add or update index entries matching files in the working directory.
+ *
+ * This method will fail in bare index instances.
+ *
+ * The `pathspec` is a list of file names or shell glob patterns that will
+ * be matched against files in the repository's working directory.  Each
+ * file that matches will be added to the index (either updating an
+ * existing entry or adding a new entry).  You can disable glob expansion
+ * and force exact matching with the `GIT_INDEX_ADD_DISABLE_PATHSPEC_MATCH`
+ * flag.
+ *
+ * Files that are ignored will be skipped (unlike `git_index_add_bypath`).
+ * If a file is already tracked in the index, then it *will* be updated
+ * even if it is ignored.  Pass the `GIT_INDEX_ADD_FORCE` flag to skip
+ * the checking of ignore rules.
+ *
+ * To emulate `git add -A` and generate an error if the pathspec contains
+ * the exact path of an ignored file (when not using FORCE), add the
+ * `GIT_INDEX_ADD_CHECK_PATHSPEC` flag.  This checks that each entry
+ * in the `pathspec` that is an exact match to a filename on disk is
+ * either not ignored or already in the index.  If this check fails, the
+ * function will return GIT_EINVALIDSPEC.
+ *
+ * To emulate `git add -A` with the "dry-run" option, just use a callback
+ * function that always returns a positive value.  See below for details.
+ *
+ * If any files are currently the result of a merge conflict, those files
+ * will no longer be marked as conflicting.  The data about the conflicts
+ * will be moved to the "resolve undo" (REUC) section.
+ *
+ * If you provide a callback function, it will be invoked on each matching
+ * item in the working directory immediately *before* it is added to /
+ * updated in the index.  Returning zero will add the item to the index,
+ * greater than zero will skip the item, and less than zero will abort the
+ * scan and return that value to the caller.
+ *
+ * @param index an existing index object
+ * @param pathspec array of path patterns
+ * @param flags combination of git_index_add_option_t flags
+ * @param callback notification callback for each added/updated path (also
+ *                 gets index of matching pathspec entry); can be NULL;
+ *                 return 0 to add, >0 to skip, <0 to abort scan.
+ * @param payload payload passed through to callback function
+ * @return 0 on success, negative callback return value, or error code
+ */
+GIT_EXTERN(int) git_index_add_all(
+	git_index *index,
+	const git_strarray *pathspec,
+	unsigned int flags,
+	git_index_matched_path_cb callback,
+	void *payload);
+
+/**
+ * Remove all matching index entries.
+ *
+ * If you provide a callback function, it will be invoked on each matching
+ * item in the index immediately *before* it is removed.  Return 0 to
+ * remove the item, > 0 to skip the item, and < 0 to abort the scan.
+ *
+ * @param index An existing index object
+ * @param pathspec array of path patterns
+ * @param callback notification callback for each removed path (also
+ *                 gets index of matching pathspec entry); can be NULL;
+ *                 return 0 to add, >0 to skip, <0 to abort scan.
+ * @param payload payload passed through to callback function
+ * @return 0 on success, negative callback return value, or error code
+ */
+GIT_EXTERN(int) git_index_remove_all(
+	git_index *index,
+	const git_strarray *pathspec,
+	git_index_matched_path_cb callback,
+	void *payload);
+
+/**
+ * Update all index entries to match the working directory
+ *
+ * This method will fail in bare index instances.
+ *
+ * This scans the existing index entries and synchronizes them with the
+ * working directory, deleting them if the corresponding working directory
+ * file no longer exists otherwise updating the information (including
+ * adding the latest version of file to the ODB if needed).
+ *
+ * If you provide a callback function, it will be invoked on each matching
+ * item in the index immediately *before* it is updated (either refreshed
+ * or removed depending on working directory state).  Return 0 to proceed
+ * with updating the item, > 0 to skip the item, and < 0 to abort the scan.
+ *
+ * @param index An existing index object
+ * @param pathspec array of path patterns
+ * @param callback notification callback for each updated path (also
+ *                 gets index of matching pathspec entry); can be NULL;
+ *                 return 0 to add, >0 to skip, <0 to abort scan.
+ * @param payload payload passed through to callback function
+ * @return 0 on success, negative callback return value, or error code
+ */
+GIT_EXTERN(int) git_index_update_all(
+	git_index *index,
+	const git_strarray *pathspec,
+	git_index_matched_path_cb callback,
+	void *payload);
+
+/**
+ * Find the first position of any entries which point to given
+ * path in the Git index.
+ *
+ * @param at_pos the address to which the position of the index entry is written (optional)
+ * @param index an existing index object
+ * @param path path to search
+ * @return a zero-based position in the index if found; GIT_ENOTFOUND otherwise
+ */
+GIT_EXTERN(int) git_index_find(size_t *at_pos, git_index *index, const char *path);
+
+/**
+ * Find the first position of any entries matching a prefix. To find the first position
+ * of a path inside a given folder, suffix the prefix with a '/'.
+ *
+ * @param at_pos the address to which the position of the index entry is written (optional)
+ * @param index an existing index object
+ * @param prefix the prefix to search for
+ * @return 0 with valid value in at_pos; an error code otherwise
+ */
+GIT_EXTERN(int) git_index_find_prefix(size_t *at_pos, git_index *index, const char *prefix);
+
+/**@}*/
+
+/** @name Conflict Index Entry Functions
+ *
+ * These functions work on conflict index entries specifically (ie, stages 1-3)
+ */
+/**@{*/
+
+/**
+ * Add or update index entries to represent a conflict.  Any staged
+ * entries that exist at the given paths will be removed.
+ *
+ * The entries are the entries from the tree included in the merge.  Any
+ * entry may be null to indicate that that file was not present in the
+ * trees during the merge.  For example, ancestor_entry may be NULL to
+ * indicate that a file was added in both branches and must be resolved.
+ *
+ * @param index an existing index object
+ * @param ancestor_entry the entry data for the ancestor of the conflict
+ * @param our_entry the entry data for our side of the merge conflict
+ * @param their_entry the entry data for their side of the merge conflict
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_index_conflict_add(
+	git_index *index,
+	const git_index_entry *ancestor_entry,
+	const git_index_entry *our_entry,
+	const git_index_entry *their_entry);
+
+/**
+ * Get the index entries that represent a conflict of a single file.
+ *
+ * The entries are not modifiable and should not be freed.  Because the
+ * `git_index_entry` struct is a publicly defined struct, you should
+ * be able to make your own permanent copy of the data if necessary.
+ *
+ * @param ancestor_out Pointer to store the ancestor entry
+ * @param our_out Pointer to store the our entry
+ * @param their_out Pointer to store the their entry
+ * @param index an existing index object
+ * @param path path to search
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_index_conflict_get(
+	const git_index_entry **ancestor_out,
+	const git_index_entry **our_out,
+	const git_index_entry **their_out,
+	git_index *index,
+	const char *path);
+
+/**
+ * Removes the index entries that represent a conflict of a single file.
+ *
+ * @param index an existing index object
+ * @param path path to remove conflicts for
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_index_conflict_remove(git_index *index, const char *path);
+
+/**
+ * Remove all conflicts in the index (entries with a stage greater than 0).
+ *
+ * @param index an existing index object
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_index_conflict_cleanup(git_index *index);
+
+/**
+ * Determine if the index contains entries representing file conflicts.
+ *
+ * @return 1 if at least one conflict is found, 0 otherwise.
+ */
+GIT_EXTERN(int) git_index_has_conflicts(const git_index *index);
+
+/**
+ * Create an iterator for the conflicts in the index.
+ *
+ * The index must not be modified while iterating; the results are undefined.
+ *
+ * @param iterator_out The newly created conflict iterator
+ * @param index The index to scan
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_index_conflict_iterator_new(
+	git_index_conflict_iterator **iterator_out,
+	git_index *index);
+
+/**
+ * Returns the current conflict (ancestor, ours and theirs entry) and
+ * advance the iterator internally to the next value.
+ *
+ * @param ancestor_out Pointer to store the ancestor side of the conflict
+ * @param our_out Pointer to store our side of the conflict
+ * @param their_out Pointer to store their side of the conflict
+ * @return 0 (no error), GIT_ITEROVER (iteration is done) or an error code
+ *         (negative value)
+ */
+GIT_EXTERN(int) git_index_conflict_next(
+	const git_index_entry **ancestor_out,
+	const git_index_entry **our_out,
+	const git_index_entry **their_out,
+	git_index_conflict_iterator *iterator);
+
+/**
+ * Frees a `git_index_conflict_iterator`.
+ *
+ * @param iterator pointer to the iterator
+ */
+GIT_EXTERN(void) git_index_conflict_iterator_free(
+	git_index_conflict_iterator *iterator);
+
+/**@}*/
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/indexer.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/indexer.h b/vendor/libgit2-sys/libgit2/include/git2/indexer.h
new file mode 100644
index 0000000..d2d315e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/indexer.h
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef _INCLUDE_git_indexer_h__
+#define _INCLUDE_git_indexer_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+
+GIT_BEGIN_DECL
+
+typedef struct git_indexer git_indexer;
+
+/**
+ * Create a new indexer instance
+ *
+ * @param out where to store the indexer instance
+ * @param path to the directory where the packfile should be stored
+ * @param mode permissions to use creating packfile or 0 for defaults
+ * @param odb object database from which to read base objects when
+ * fixing thin packs. Pass NULL if no thin pack is expected (an error
+ * will be returned if there are bases missing)
+ * @param progress_cb function to call with progress information
+ * @param progress_cb_payload payload for the progress callback
+ */
+GIT_EXTERN(int) git_indexer_new(
+		git_indexer **out,
+		const char *path,
+		unsigned int mode,
+		git_odb *odb,
+		git_transfer_progress_cb progress_cb,
+		void *progress_cb_payload);
+
+/**
+ * Add data to the indexer
+ *
+ * @param idx the indexer
+ * @param data the data to add
+ * @param size the size of the data in bytes
+ * @param stats stat storage
+ */
+GIT_EXTERN(int) git_indexer_append(git_indexer *idx, const void *data, size_t size, git_transfer_progress *stats);
+
+/**
+ * Finalize the pack and index
+ *
+ * Resolve any pending deltas and write out the index file
+ *
+ * @param idx the indexer
+ */
+GIT_EXTERN(int) git_indexer_commit(git_indexer *idx, git_transfer_progress *stats);
+
+/**
+ * Get the packfile's hash
+ *
+ * A packfile's name is derived from the sorted hashing of all object
+ * names. This is only correct after the index has been finalized.
+ *
+ * @param idx the indexer instance
+ */
+GIT_EXTERN(const git_oid *) git_indexer_hash(const git_indexer *idx);
+
+/**
+ * Free the indexer and its resources
+ *
+ * @param idx the indexer to free
+ */
+GIT_EXTERN(void) git_indexer_free(git_indexer *idx);
+
+GIT_END_DECL
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/inttypes.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/inttypes.h b/vendor/libgit2-sys/libgit2/include/git2/inttypes.h
new file mode 100644
index 0000000..17364c7
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/inttypes.h
@@ -0,0 +1,309 @@
+// ISO C9x  compliant inttypes.h for Microsoft Visual Studio
+// Based on ISO/IEC 9899:TC2 Committee draft (May 6, 2005) WG14/N1124
+//
+//  Copyright (c) 2006 Alexander Chemeris
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//   1. Redistributions of source code must retain the above copyright notice,
+//      this list of conditions and the following disclaimer.
+//
+//   2. Redistributions in binary form must reproduce the above copyright
+//      notice, this list of conditions and the following disclaimer in the
+//      documentation and/or other materials provided with the distribution.
+//
+//   3. The name of the author may be used to endorse or promote products
+//      derived from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+// WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+// EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+// OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+// WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+// OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+// ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef _MSC_VER // [
+#error "Use this header only with Microsoft Visual C++ compilers!"
+#endif // _MSC_VER ]
+
+#ifndef _MSC_INTTYPES_H_ // [
+#define _MSC_INTTYPES_H_
+
+#if _MSC_VER > 1000
+#pragma once
+#endif
+
+#if _MSC_VER >= 1600
+#include <stdint.h>
+#else
+#include "stdint.h"
+#endif
+
+// 7.8 Format conversion of integer types
+
+typedef struct {
+   intmax_t quot;
+   intmax_t rem;
+} imaxdiv_t;
+
+// 7.8.1 Macros for format specifiers
+
+#if !defined(__cplusplus) || defined(__STDC_FORMAT_MACROS) // [   See footnote 185 at page 198
+
+// The fprintf macros for signed integers are:
+#define PRId8       "d"
+#define PRIi8       "i"
+#define PRIdLEAST8  "d"
+#define PRIiLEAST8  "i"
+#define PRIdFAST8   "d"
+#define PRIiFAST8   "i"
+
+#define PRId16       "hd"
+#define PRIi16       "hi"
+#define PRIdLEAST16  "hd"
+#define PRIiLEAST16  "hi"
+#define PRIdFAST16   "hd"
+#define PRIiFAST16   "hi"
+
+#define PRId32       "I32d"
+#define PRIi32       "I32i"
+#define PRIdLEAST32  "I32d"
+#define PRIiLEAST32  "I32i"
+#define PRIdFAST32   "I32d"
+#define PRIiFAST32   "I32i"
+
+#define PRId64       "I64d"
+#define PRIi64       "I64i"
+#define PRIdLEAST64  "I64d"
+#define PRIiLEAST64  "I64i"
+#define PRIdFAST64   "I64d"
+#define PRIiFAST64   "I64i"
+
+#define PRIdMAX     "I64d"
+#define PRIiMAX     "I64i"
+
+#define PRIdPTR     "Id"
+#define PRIiPTR     "Ii"
+
+// The fprintf macros for unsigned integers are:
+#define PRIo8       "o"
+#define PRIu8       "u"
+#define PRIx8       "x"
+#define PRIX8       "X"
+#define PRIoLEAST8  "o"
+#define PRIuLEAST8  "u"
+#define PRIxLEAST8  "x"
+#define PRIXLEAST8  "X"
+#define PRIoFAST8   "o"
+#define PRIuFAST8   "u"
+#define PRIxFAST8   "x"
+#define PRIXFAST8   "X"
+
+#define PRIo16       "ho"
+#define PRIu16       "hu"
+#define PRIx16       "hx"
+#define PRIX16       "hX"
+#define PRIoLEAST16  "ho"
+#define PRIuLEAST16  "hu"
+#define PRIxLEAST16  "hx"
+#define PRIXLEAST16  "hX"
+#define PRIoFAST16   "ho"
+#define PRIuFAST16   "hu"
+#define PRIxFAST16   "hx"
+#define PRIXFAST16   "hX"
+
+#define PRIo32       "I32o"
+#define PRIu32       "I32u"
+#define PRIx32       "I32x"
+#define PRIX32       "I32X"
+#define PRIoLEAST32  "I32o"
+#define PRIuLEAST32  "I32u"
+#define PRIxLEAST32  "I32x"
+#define PRIXLEAST32  "I32X"
+#define PRIoFAST32   "I32o"
+#define PRIuFAST32   "I32u"
+#define PRIxFAST32   "I32x"
+#define PRIXFAST32   "I32X"
+
+#define PRIo64       "I64o"
+#define PRIu64       "I64u"
+#define PRIx64       "I64x"
+#define PRIX64       "I64X"
+#define PRIoLEAST64  "I64o"
+#define PRIuLEAST64  "I64u"
+#define PRIxLEAST64  "I64x"
+#define PRIXLEAST64  "I64X"
+#define PRIoFAST64   "I64o"
+#define PRIuFAST64   "I64u"
+#define PRIxFAST64   "I64x"
+#define PRIXFAST64   "I64X"
+
+#define PRIoMAX     "I64o"
+#define PRIuMAX     "I64u"
+#define PRIxMAX     "I64x"
+#define PRIXMAX     "I64X"
+
+#define PRIoPTR     "Io"
+#define PRIuPTR     "Iu"
+#define PRIxPTR     "Ix"
+#define PRIXPTR     "IX"
+
+// The fscanf macros for signed integers are:
+#define SCNd8       "d"
+#define SCNi8       "i"
+#define SCNdLEAST8  "d"
+#define SCNiLEAST8  "i"
+#define SCNdFAST8   "d"
+#define SCNiFAST8   "i"
+
+#define SCNd16       "hd"
+#define SCNi16       "hi"
+#define SCNdLEAST16  "hd"
+#define SCNiLEAST16  "hi"
+#define SCNdFAST16   "hd"
+#define SCNiFAST16   "hi"
+
+#define SCNd32       "ld"
+#define SCNi32       "li"
+#define SCNdLEAST32  "ld"
+#define SCNiLEAST32  "li"
+#define SCNdFAST32   "ld"
+#define SCNiFAST32   "li"
+
+#define SCNd64       "I64d"
+#define SCNi64       "I64i"
+#define SCNdLEAST64  "I64d"
+#define SCNiLEAST64  "I64i"
+#define SCNdFAST64   "I64d"
+#define SCNiFAST64   "I64i"
+
+#define SCNdMAX     "I64d"
+#define SCNiMAX     "I64i"
+
+#ifdef _WIN64 // [
+#  define SCNdPTR     "I64d"
+#  define SCNiPTR     "I64i"
+#else  // _WIN64 ][
+#  define SCNdPTR     "ld"
+#  define SCNiPTR     "li"
+#endif  // _WIN64 ]
+
+// The fscanf macros for unsigned integers are:
+#define SCNo8       "o"
+#define SCNu8       "u"
+#define SCNx8       "x"
+#define SCNX8       "X"
+#define SCNoLEAST8  "o"
+#define SCNuLEAST8  "u"
+#define SCNxLEAST8  "x"
+#define SCNXLEAST8  "X"
+#define SCNoFAST8   "o"
+#define SCNuFAST8   "u"
+#define SCNxFAST8   "x"
+#define SCNXFAST8   "X"
+
+#define SCNo16       "ho"
+#define SCNu16       "hu"
+#define SCNx16       "hx"
+#define SCNX16       "hX"
+#define SCNoLEAST16  "ho"
+#define SCNuLEAST16  "hu"
+#define SCNxLEAST16  "hx"
+#define SCNXLEAST16  "hX"
+#define SCNoFAST16   "ho"
+#define SCNuFAST16   "hu"
+#define SCNxFAST16   "hx"
+#define SCNXFAST16   "hX"
+
+#define SCNo32       "lo"
+#define SCNu32       "lu"
+#define SCNx32       "lx"
+#define SCNX32       "lX"
+#define SCNoLEAST32  "lo"
+#define SCNuLEAST32  "lu"
+#define SCNxLEAST32  "lx"
+#define SCNXLEAST32  "lX"
+#define SCNoFAST32   "lo"
+#define SCNuFAST32   "lu"
+#define SCNxFAST32   "lx"
+#define SCNXFAST32   "lX"
+
+#define SCNo64       "I64o"
+#define SCNu64       "I64u"
+#define SCNx64       "I64x"
+#define SCNX64       "I64X"
+#define SCNoLEAST64  "I64o"
+#define SCNuLEAST64  "I64u"
+#define SCNxLEAST64  "I64x"
+#define SCNXLEAST64  "I64X"
+#define SCNoFAST64   "I64o"
+#define SCNuFAST64   "I64u"
+#define SCNxFAST64   "I64x"
+#define SCNXFAST64   "I64X"
+
+#define SCNoMAX     "I64o"
+#define SCNuMAX     "I64u"
+#define SCNxMAX     "I64x"
+#define SCNXMAX     "I64X"
+
+#ifdef _WIN64 // [
+#  define SCNoPTR     "I64o"
+#  define SCNuPTR     "I64u"
+#  define SCNxPTR     "I64x"
+#  define SCNXPTR     "I64X"
+#else  // _WIN64 ][
+#  define SCNoPTR     "lo"
+#  define SCNuPTR     "lu"
+#  define SCNxPTR     "lx"
+#  define SCNXPTR     "lX"
+#endif  // _WIN64 ]
+
+#endif // __STDC_FORMAT_MACROS ]
+
+// 7.8.2 Functions for greatest-width integer types
+
+// 7.8.2.1 The imaxabs function
+#define imaxabs _abs64
+
+// 7.8.2.2 The imaxdiv function
+
+// This is modified version of div() function from Microsoft's div.c found
+// in %MSVC.NET%\crt\src\div.c
+#ifdef STATIC_IMAXDIV // [
+static
+#else // STATIC_IMAXDIV ][
+_inline
+#endif // STATIC_IMAXDIV ]
+imaxdiv_t __cdecl imaxdiv(intmax_t numer, intmax_t denom)
+{
+	imaxdiv_t result;
+
+	result.quot = numer / denom;
+	result.rem = numer % denom;
+
+	if (numer < 0 && result.rem > 0) {
+		// did division wrong; must fix up
+		++result.quot;
+		result.rem -= denom;
+	}
+
+	return result;
+}
+
+// 7.8.2.3 The strtoimax and strtoumax functions
+#define strtoimax _strtoi64
+#define strtoumax _strtoui64
+
+// 7.8.2.4 The wcstoimax and wcstoumax functions
+#define wcstoimax _wcstoi64
+#define wcstoumax _wcstoui64
+
+
+#endif // _MSC_INTTYPES_H_ ]

vendor/libgit2-sys/libgit2/include/git2/merge.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/merge.h b/vendor/libgit2-sys/libgit2/include/git2/merge.h
new file mode 100644
index 0000000..80ef864
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/merge.h
@@ -0,0 +1,589 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_merge_h__
+#define INCLUDE_git_merge_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+#include "oidarray.h"
+#include "checkout.h"
+#include "index.h"
+#include "annotated_commit.h"
+
+/**
+ * @file git2/merge.h
+ * @brief Git merge routines
+ * @defgroup git_merge Git merge routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * The file inputs to `git_merge_file`.  Callers should populate the
+ * `git_merge_file_input` structure with descriptions of the files in
+ * each side of the conflict for use in producing the merge file.
+ */
+typedef struct {
+	unsigned int version;
+
+	/** Pointer to the contents of the file. */
+	const char *ptr;
+
+	/** Size of the contents pointed to in `ptr`. */
+	size_t size;
+
+	/** File name of the conflicted file, or `NULL` to not merge the path. */
+	const char *path;
+
+	/** File mode of the conflicted file, or `0` to not merge the mode. */
+	unsigned int mode;
+} git_merge_file_input;
+
+#define GIT_MERGE_FILE_INPUT_VERSION 1
+#define GIT_MERGE_FILE_INPUT_INIT {GIT_MERGE_FILE_INPUT_VERSION}
+
+/**
+ * Initializes a `git_merge_file_input` with default values. Equivalent to
+ * creating an instance with GIT_MERGE_FILE_INPUT_INIT.
+ *
+ * @param opts the `git_merge_file_input` instance to initialize.
+ * @param version the version of the struct; you should pass
+ *        `GIT_MERGE_FILE_INPUT_VERSION` here.
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_merge_file_init_input(
+	git_merge_file_input *opts,
+	unsigned int version);
+
+/**
+ * Flags for `git_merge` options.  A combination of these flags can be
+ * passed in via the `flags` value in the `git_merge_options`.
+ */
+typedef enum {
+	/**
+	 * Detect renames that occur between the common ancestor and the "ours"
+	 * side or the common ancestor and the "theirs" side.  This will enable
+	 * the ability to merge between a modified and renamed file.
+	 */
+	GIT_MERGE_FIND_RENAMES = (1 << 0),
+
+	/**
+	 * If a conflict occurs, exit immediately instead of attempting to
+	 * continue resolving conflicts.  The merge operation will fail with
+	 * GIT_EMERGECONFLICT and no index will be returned.
+	 */
+	GIT_MERGE_FAIL_ON_CONFLICT = (1 << 1),
+
+	/**
+	 * Do not write the REUC extension on the generated index
+	 */
+	GIT_MERGE_SKIP_REUC = (1 << 2),
+
+	/**
+	 * If the commits being merged have multiple merge bases, do not build
+	 * a recursive merge base (by merging the multiple merge bases),
+	 * instead simply use the first base.  This flag provides a similar
+	 * merge base to `git-merge-resolve`.
+	 */
+	GIT_MERGE_NO_RECURSIVE = (1 << 3),
+} git_merge_flag_t;
+
+/**
+ * Merge file favor options for `git_merge_options` instruct the file-level
+ * merging functionality how to deal with conflicting regions of the files.
+ */
+typedef enum {
+	/**
+	 * When a region of a file is changed in both branches, a conflict
+	 * will be recorded in the index so that `git_checkout` can produce
+	 * a merge file with conflict markers in the working directory.
+	 * This is the default.
+	 */
+	GIT_MERGE_FILE_FAVOR_NORMAL = 0,
+
+	/**
+	 * When a region of a file is changed in both branches, the file
+	 * created in the index will contain the "ours" side of any conflicting
+	 * region.  The index will not record a conflict.
+	 */
+	GIT_MERGE_FILE_FAVOR_OURS = 1,
+
+	/**
+	 * When a region of a file is changed in both branches, the file
+	 * created in the index will contain the "theirs" side of any conflicting
+	 * region.  The index will not record a conflict.
+	 */
+	GIT_MERGE_FILE_FAVOR_THEIRS = 2,
+
+	/**
+	 * When a region of a file is changed in both branches, the file
+	 * created in the index will contain each unique line from each side,
+	 * which has the result of combining both files.  The index will not
+	 * record a conflict.
+	 */
+	GIT_MERGE_FILE_FAVOR_UNION = 3,
+} git_merge_file_favor_t;
+
+/**
+ * File merging flags
+ */
+typedef enum {
+	/** Defaults */
+	GIT_MERGE_FILE_DEFAULT = 0,
+
+	/** Create standard conflicted merge files */
+	GIT_MERGE_FILE_STYLE_MERGE = (1 << 0),
+
+	/** Create diff3-style files */
+	GIT_MERGE_FILE_STYLE_DIFF3 = (1 << 1),
+
+	/** Condense non-alphanumeric regions for simplified diff file */
+	GIT_MERGE_FILE_SIMPLIFY_ALNUM = (1 << 2),
+
+	/** Ignore all whitespace */
+	GIT_MERGE_FILE_IGNORE_WHITESPACE = (1 << 3),
+
+	/** Ignore changes in amount of whitespace */
+	GIT_MERGE_FILE_IGNORE_WHITESPACE_CHANGE = (1 << 4),
+
+	/** Ignore whitespace at end of line */
+	GIT_MERGE_FILE_IGNORE_WHITESPACE_EOL = (1 << 5),
+
+	/** Use the "patience diff" algorithm */
+	GIT_MERGE_FILE_DIFF_PATIENCE = (1 << 6),
+
+	/** Take extra time to find minimal diff */
+	GIT_MERGE_FILE_DIFF_MINIMAL = (1 << 7),
+} git_merge_file_flag_t;
+
+#define GIT_MERGE_CONFLICT_MARKER_SIZE	7
+
+/**
+ * Options for merging a file
+ */
+typedef struct {
+	unsigned int version;
+
+	/**
+	 * Label for the ancestor file side of the conflict which will be prepended
+	 * to labels in diff3-format merge files.
+	 */
+	const char *ancestor_label;
+
+	/**
+	 * Label for our file side of the conflict which will be prepended
+	 * to labels in merge files.
+	 */
+	const char *our_label;
+
+	/**
+	 * Label for their file side of the conflict which will be prepended
+	 * to labels in merge files.
+	 */
+	const char *their_label;
+
+	/** The file to favor in region conflicts. */
+	git_merge_file_favor_t favor;
+
+	/** see `git_merge_file_flag_t` above */
+	git_merge_file_flag_t flags;
+
+	/** The size of conflict markers (eg, "<<<<<<<").  Default is
+	 * GIT_MERGE_CONFLICT_MARKER_SIZE. */
+	unsigned short marker_size;
+} git_merge_file_options;
+
+#define GIT_MERGE_FILE_OPTIONS_VERSION 1
+#define GIT_MERGE_FILE_OPTIONS_INIT {GIT_MERGE_FILE_OPTIONS_VERSION}
+
+/**
+ * Initializes a `git_merge_file_options` with default values. Equivalent to
+ * creating an instance with GIT_MERGE_FILE_OPTIONS_INIT.
+ *
+ * @param opts the `git_merge_file_options` instance to initialize.
+ * @param version the version of the struct; you should pass
+ *        `GIT_MERGE_FILE_OPTIONS_VERSION` here.
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_merge_file_init_options(
+	git_merge_file_options *opts,
+	unsigned int version);
+
+/**
+ * Information about file-level merging
+ */
+typedef struct {
+	/**
+	 * True if the output was automerged, false if the output contains
+	 * conflict markers.
+	 */
+	unsigned int automergeable;
+
+	/**
+	 * The path that the resultant merge file should use, or NULL if a
+	 * filename conflict would occur.
+	 */
+	const char *path;
+
+	/** The mode that the resultant merge file should use.  */
+	unsigned int mode;
+
+	/** The contents of the merge. */
+	const char *ptr;
+
+	/** The length of the merge contents. */
+	size_t len;
+} git_merge_file_result;
+
+/**
+ * Merging options
+ */
+typedef struct {
+	unsigned int version;
+
+	/** See `git_merge_flag_t` above */
+	git_merge_flag_t flags;
+
+	/**
+	 * Similarity to consider a file renamed (default 50).  If
+	 * `GIT_MERGE_FIND_RENAMES` is enabled, added files will be compared
+	 * with deleted files to determine their similarity.  Files that are
+	 * more similar than the rename threshold (percentage-wise) will be
+	 * treated as a rename.
+	 */
+	unsigned int rename_threshold;
+
+	/**
+	 * Maximum similarity sources to examine for renames (default 200).
+	 * If the number of rename candidates (add / delete pairs) is greater
+	 * than this value, inexact rename detection is aborted.
+	 *
+	 * This setting overrides the `merge.renameLimit` configuration value.
+	 */
+	unsigned int target_limit;
+
+	/** Pluggable similarity metric; pass NULL to use internal metric */
+	git_diff_similarity_metric *metric;
+
+	/**
+	 * Maximum number of times to merge common ancestors to build a
+	 * virtual merge base when faced with criss-cross merges.  When this
+	 * limit is reached, the next ancestor will simply be used instead of
+	 * attempting to merge it.  The default is unlimited.
+	 */
+	unsigned int recursion_limit;
+
+	/**
+	 * Default merge driver to be used when both sides of a merge have
+	 * changed.  The default is the `text` driver.
+	 */
+	const char *default_driver;
+
+	/**
+	 * Flags for handling conflicting content, to be used with the standard
+	 * (`text`) merge driver.
+	 */
+	git_merge_file_favor_t file_favor;
+
+	/** see `git_merge_file_flag_t` above */
+	git_merge_file_flag_t file_flags;
+} git_merge_options;
+
+#define GIT_MERGE_OPTIONS_VERSION 1
+#define GIT_MERGE_OPTIONS_INIT { \
+	GIT_MERGE_OPTIONS_VERSION, GIT_MERGE_FIND_RENAMES }
+
+/**
+ * Initializes a `git_merge_options` with default values. Equivalent to
+ * creating an instance with GIT_MERGE_OPTIONS_INIT.
+ *
+ * @param opts the `git_merge_options` instance to initialize.
+ * @param version the version of the struct; you should pass
+ *        `GIT_MERGE_OPTIONS_VERSION` here.
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_merge_init_options(
+	git_merge_options *opts,
+	unsigned int version);
+
+/**
+ * The results of `git_merge_analysis` indicate the merge opportunities.
+ */
+typedef enum {
+	/** No merge is possible.  (Unused.) */
+	GIT_MERGE_ANALYSIS_NONE = 0,
+
+	/**
+	 * A "normal" merge; both HEAD and the given merge input have diverged
+	 * from their common ancestor.  The divergent commits must be merged.
+	 */
+	GIT_MERGE_ANALYSIS_NORMAL = (1 << 0),
+
+	/**
+	 * All given merge inputs are reachable from HEAD, meaning the
+	 * repository is up-to-date and no merge needs to be performed.
+	 */
+	GIT_MERGE_ANALYSIS_UP_TO_DATE = (1 << 1),
+
+	/**
+	 * The given merge input is a fast-forward from HEAD and no merge
+	 * needs to be performed.  Instead, the client can check out the
+	 * given merge input.
+	 */
+	GIT_MERGE_ANALYSIS_FASTFORWARD = (1 << 2),
+
+	/**
+	 * The HEAD of the current repository is "unborn" and does not point to
+	 * a valid commit.  No merge can be performed, but the caller may wish
+	 * to simply set HEAD to the target commit(s).
+	 */
+	GIT_MERGE_ANALYSIS_UNBORN = (1 << 3),
+} git_merge_analysis_t;
+
+/**
+ * The user's stated preference for merges.
+ */
+typedef enum {
+	/**
+	 * No configuration was found that suggests a preferred behavior for
+	 * merge.
+	 */
+	GIT_MERGE_PREFERENCE_NONE = 0,
+
+	/**
+	 * There is a `merge.ff=false` configuration setting, suggesting that
+	 * the user does not want to allow a fast-forward merge.
+	 */
+	GIT_MERGE_PREFERENCE_NO_FASTFORWARD = (1 << 0),
+
+	/**
+	 * There is a `merge.ff=only` configuration setting, suggesting that
+	 * the user only wants fast-forward merges.
+	 */
+	GIT_MERGE_PREFERENCE_FASTFORWARD_ONLY = (1 << 1),
+} git_merge_preference_t;
+
+/**
+ * Analyzes the given branch(es) and determines the opportunities for
+ * merging them into the HEAD of the repository.
+ *
+ * @param analysis_out analysis enumeration that the result is written into
+ * @param repo the repository to merge
+ * @param their_heads the heads to merge into
+ * @param their_heads_len the number of heads to merge
+ * @return 0 on success or error code
+ */
+GIT_EXTERN(int) git_merge_analysis(
+	git_merge_analysis_t *analysis_out,
+	git_merge_preference_t *preference_out,
+	git_repository *repo,
+	const git_annotated_commit **their_heads,
+	size_t their_heads_len);
+
+/**
+ * Find a merge base between two commits
+ *
+ * @param out the OID of a merge base between 'one' and 'two'
+ * @param repo the repository where the commits exist
+ * @param one one of the commits
+ * @param two the other commit
+ * @return 0 on success, GIT_ENOTFOUND if not found or error code
+ */
+GIT_EXTERN(int) git_merge_base(
+	git_oid *out,
+	git_repository *repo,
+	const git_oid *one,
+	const git_oid *two);
+
+/**
+ * Find merge bases between two commits
+ *
+ * @param out array in which to store the resulting ids
+ * @param repo the repository where the commits exist
+ * @param one one of the commits
+ * @param two the other commit
+ * @return 0 on success, GIT_ENOTFOUND if not found or error code
+ */
+GIT_EXTERN(int) git_merge_bases(
+	git_oidarray *out,
+	git_repository *repo,
+	const git_oid *one,
+	const git_oid *two);
+
+/**
+ * Find a merge base given a list of commits
+ *
+ * @param out the OID of a merge base considering all the commits
+ * @param repo the repository where the commits exist
+ * @param length The number of commits in the provided `input_array`
+ * @param input_array oids of the commits
+ * @return Zero on success; GIT_ENOTFOUND or -1 on failure.
+ */
+GIT_EXTERN(int) git_merge_base_many(
+	git_oid *out,
+	git_repository *repo,
+	size_t length,
+	const git_oid input_array[]);
+
+/**
+ * Find all merge bases given a list of commits
+ *
+ * @param out array in which to store the resulting ids
+ * @param repo the repository where the commits exist
+ * @param length The number of commits in the provided `input_array`
+ * @param input_array oids of the commits
+ * @return Zero on success; GIT_ENOTFOUND or -1 on failure.
+ */
+GIT_EXTERN(int) git_merge_bases_many(
+	git_oidarray *out,
+	git_repository *repo,
+	size_t length,
+	const git_oid input_array[]);
+
+/**
+ * Find a merge base in preparation for an octopus merge
+ *
+ * @param out the OID of a merge base considering all the commits
+ * @param repo the repository where the commits exist
+ * @param length The number of commits in the provided `input_array`
+ * @param input_array oids of the commits
+ * @return Zero on success; GIT_ENOTFOUND or -1 on failure.
+ */
+GIT_EXTERN(int) git_merge_base_octopus(
+	git_oid *out,
+	git_repository *repo,
+	size_t length,
+	const git_oid input_array[]);
+
+/**
+ * Merge two files as they exist in the in-memory data structures, using
+ * the given common ancestor as the baseline, producing a
+ * `git_merge_file_result` that reflects the merge result.  The
+ * `git_merge_file_result` must be freed with `git_merge_file_result_free`.
+ *
+ * Note that this function does not reference a repository and any
+ * configuration must be passed as `git_merge_file_options`.
+ *
+ * @param out The git_merge_file_result to be filled in
+ * @param ancestor The contents of the ancestor file
+ * @param ours The contents of the file in "our" side
+ * @param theirs The contents of the file in "their" side
+ * @param opts The merge file options or `NULL` for defaults
+ * @return 0 on success or error code
+ */
+GIT_EXTERN(int) git_merge_file(
+	git_merge_file_result *out,
+	const git_merge_file_input *ancestor,
+	const git_merge_file_input *ours,
+	const git_merge_file_input *theirs,
+	const git_merge_file_options *opts);
+
+/**
+ * Merge two files as they exist in the index, using the given common
+ * ancestor as the baseline, producing a `git_merge_file_result` that
+ * reflects the merge result.  The `git_merge_file_result` must be freed with
+ * `git_merge_file_result_free`.
+ *
+ * @param out The git_merge_file_result to be filled in
+ * @param repo The repository
+ * @param ancestor The index entry for the ancestor file (stage level 1)
+ * @param ours The index entry for our file (stage level 2)
+ * @param theirs The index entry for their file (stage level 3)
+ * @param opts The merge file options or NULL
+ * @return 0 on success or error code
+ */
+GIT_EXTERN(int) git_merge_file_from_index(
+	git_merge_file_result *out,
+	git_repository *repo,
+	const git_index_entry *ancestor,
+	const git_index_entry *ours,
+	const git_index_entry *theirs,
+	const git_merge_file_options *opts);
+
+/**
+ * Frees a `git_merge_file_result`.
+ *
+ * @param result The result to free or `NULL`
+ */
+GIT_EXTERN(void) git_merge_file_result_free(git_merge_file_result *result);
+
+/**
+ * Merge two trees, producing a `git_index` that reflects the result of
+ * the merge.  The index may be written as-is to the working directory
+ * or checked out.  If the index is to be converted to a tree, the caller
+ * should resolve any conflicts that arose as part of the merge.
+ *
+ * The returned index must be freed explicitly with `git_index_free`.
+ *
+ * @param out pointer to store the index result in
+ * @param repo repository that contains the given trees
+ * @param ancestor_tree the common ancestor between the trees (or null if none)
+ * @param our_tree the tree that reflects the destination tree
+ * @param their_tree the tree to merge in to `our_tree`
+ * @param opts the merge tree options (or null for defaults)
+ * @return 0 on success or error code
+ */
+GIT_EXTERN(int) git_merge_trees(
+	git_index **out,
+	git_repository *repo,
+	const git_tree *ancestor_tree,
+	const git_tree *our_tree,
+	const git_tree *their_tree,
+	const git_merge_options *opts);
+
+/**
+ * Merge two commits, producing a `git_index` that reflects the result of
+ * the merge.  The index may be written as-is to the working directory
+ * or checked out.  If the index is to be converted to a tree, the caller
+ * should resolve any conflicts that arose as part of the merge.
+ *
+ * The returned index must be freed explicitly with `git_index_free`.
+ *
+ * @param out pointer to store the index result in
+ * @param repo repository that contains the given trees
+ * @param our_commit the commit that reflects the destination tree
+ * @param their_commit the commit to merge in to `our_commit`
+ * @param opts the merge tree options (or null for defaults)
+ * @return 0 on success or error code
+ */
+GIT_EXTERN(int) git_merge_commits(
+	git_index **out,
+	git_repository *repo,
+	const git_commit *our_commit,
+	const git_commit *their_commit,
+	const git_merge_options *opts);
+
+/**
+ * Merges the given commit(s) into HEAD, writing the results into the working
+ * directory.  Any changes are staged for commit and any conflicts are written
+ * to the index.  Callers should inspect the repository's index after this
+ * completes, resolve any conflicts and prepare a commit.
+ *
+ * For compatibility with git, the repository is put into a merging
+ * state. Once the commit is done (or if the uses wishes to abort),
+ * you should clear this state by calling
+ * `git_repository_state_cleanup()`.
+ *
+ * @param repo the repository to merge
+ * @param their_heads the heads to merge into
+ * @param their_heads_len the number of heads to merge
+ * @param merge_opts merge options
+ * @param checkout_opts checkout options
+ * @return 0 on success or error code
+ */
+GIT_EXTERN(int) git_merge(
+	git_repository *repo,
+	const git_annotated_commit **their_heads,
+	size_t their_heads_len,
+	const git_merge_options *merge_opts,
+	const git_checkout_options *checkout_opts);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/message.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/message.h b/vendor/libgit2-sys/libgit2/include/git2/message.h
new file mode 100644
index 0000000..42ca3e5
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/message.h
@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_message_h__
+#define INCLUDE_git_message_h__
+
+#include "common.h"
+#include "buffer.h"
+
+/**
+ * @file git2/message.h
+ * @brief Git message management routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Clean up excess whitespace and make sure there is a trailing newline in the message.
+ *
+ * Optionally, it can remove lines which start with the comment character.
+ *
+ * @param out The user-allocated git_buf which will be filled with the
+ *     cleaned up message.
+ *
+ * @param message The message to be prettified.
+ *
+ * @param strip_comments Non-zero to remove comment lines, 0 to leave them in.
+ *
+ * @param comment_char Comment character. Lines starting with this character
+ * are considered to be comments and removed if `strip_comments` is non-zero.
+ *
+ * @return 0 or an error code.
+ */
+GIT_EXTERN(int) git_message_prettify(git_buf *out, const char *message, int strip_comments, char comment_char);
+
+/**
+ * Represents a single git message trailer.
+ */
+typedef struct {
+  const char *key;
+  const char *value;
+} git_message_trailer;
+
+/**
+ * Represents an array of git message trailers.
+ *
+ * Struct members under the private comment are private, subject to change
+ * and should not be used by callers.
+ */
+typedef struct {
+  git_message_trailer *trailers;
+  size_t count;
+
+  /* private */
+  char *_trailer_block;
+} git_message_trailer_array;
+
+/**
+ * Parse trailers out of a message, filling the array pointed to by +arr+.
+ *
+ * Trailers are key/value pairs in the last paragraph of a message, not
+ * including any patches or conflicts that may be present.
+ *
+ * @param arr A pre-allocated git_message_trailer_array struct to be filled in
+ *            with any trailers found during parsing.
+ * @param message The message to be parsed
+ * @return 0 on success, or non-zero on error.
+ */
+GIT_EXTERN(int) git_message_trailers(git_message_trailer_array *arr, const char *message);
+
+/**
+ * Clean's up any allocated memory in the git_message_trailer_array filled by
+ * a call to git_message_trailers.
+ */
+GIT_EXTERN(void) git_message_trailer_array_free(git_message_trailer_array *arr);
+
+/** @} */
+GIT_END_DECL
+
+#endif /* INCLUDE_git_message_h__ */

vendor/libgit2-sys/libgit2/include/git2/net.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/net.h b/vendor/libgit2-sys/libgit2/include/git2/net.h
new file mode 100644
index 0000000..04dff34
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/net.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_net_h__
+#define INCLUDE_git_net_h__
+
+#include "common.h"
+#include "oid.h"
+#include "types.h"
+
+/**
+ * @file git2/net.h
+ * @brief Git networking declarations
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+#define GIT_DEFAULT_PORT "9418"
+
+/**
+ * Direction of the connection.
+ *
+ * We need this because we need to know whether we should call
+ * git-upload-pack or git-receive-pack on the remote end when get_refs
+ * gets called.
+ */
+typedef enum {
+	GIT_DIRECTION_FETCH = 0,
+	GIT_DIRECTION_PUSH  = 1
+} git_direction;
+
+/**
+ * Description of a reference advertised by a remote server, given out
+ * on `ls` calls.
+ */
+struct git_remote_head {
+	int local; /* available locally */
+	git_oid oid;
+	git_oid loid;
+	char *name;
+	/**
+	 * If the server send a symref mapping for this ref, this will
+	 * point to the target.
+	 */
+	char *symref_target;
+};
+
+/**
+ * Callback for listing the remote heads
+ */
+typedef int (*git_headlist_cb)(git_remote_head *rhead, void *payload);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/notes.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/notes.h b/vendor/libgit2-sys/libgit2/include/git2/notes.h
new file mode 100644
index 0000000..853e5de
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/notes.h
@@ -0,0 +1,306 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_note_h__
+#define INCLUDE_git_note_h__
+
+#include "oid.h"
+
+/**
+ * @file git2/notes.h
+ * @brief Git notes management routines
+ * @defgroup git_note Git notes management routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Callback for git_note_foreach.
+ *
+ * Receives:
+ * - blob_id: Oid of the blob containing the message
+ * - annotated_object_id: Oid of the git object being annotated
+ * - payload: Payload data passed to `git_note_foreach`
+ */
+typedef int (*git_note_foreach_cb)(
+	const git_oid *blob_id, const git_oid *annotated_object_id, void *payload);
+
+/**
+ * note iterator
+ */
+typedef struct git_iterator git_note_iterator;
+
+/**
+ * Creates a new iterator for notes
+ *
+ * The iterator must be freed manually by the user.
+ *
+ * @param out pointer to the iterator
+ * @param repo repository where to look up the note
+ * @param notes_ref canonical name of the reference to use (optional); defaults to
+ *                  "refs/notes/commits"
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_note_iterator_new(
+	git_note_iterator **out,
+	git_repository *repo,
+	const char *notes_ref);
+
+/**
+ * Creates a new iterator for notes from a commit
+ *
+ * The iterator must be freed manually by the user.
+ *
+ * @param out pointer to the iterator
+ * @param notes_commit a pointer to the notes commit object
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_note_commit_iterator_new(
+	git_note_iterator **out,
+	git_commit *notes_commit);
+
+/**
+ * Frees an git_note_iterator
+ *
+ * @param it pointer to the iterator
+ */
+GIT_EXTERN(void) git_note_iterator_free(git_note_iterator *it);
+
+/**
+ * Return the current item (note_id and annotated_id) and advance the iterator
+ * internally to the next value
+ *
+ * @param note_id id of blob containing the message
+ * @param annotated_id id of the git object being annotated
+ * @param it pointer to the iterator
+ *
+ * @return 0 (no error), GIT_ITEROVER (iteration is done) or an error code
+ *         (negative value)
+ */
+GIT_EXTERN(int) git_note_next(
+	git_oid* note_id,
+	git_oid* annotated_id,
+	git_note_iterator *it);
+
+
+/**
+ * Read the note for an object
+ *
+ * The note must be freed manually by the user.
+ *
+ * @param out pointer to the read note; NULL in case of error
+ * @param repo repository where to look up the note
+ * @param notes_ref canonical name of the reference to use (optional); defaults to
+ *                  "refs/notes/commits"
+ * @param oid OID of the git object to read the note from
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_note_read(
+	git_note **out,
+	git_repository *repo,
+	const char *notes_ref,
+	const git_oid *oid);
+
+
+/**
+ * Read the note for an object from a note commit
+ *
+ * The note must be freed manually by the user.
+ *
+ * @param out pointer to the read note; NULL in case of error
+ * @param repo repository where to look up the note
+ * @param notes_commit a pointer to the notes commit object
+ * @param oid OID of the git object to read the note from
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_note_commit_read(
+	git_note **out,
+	git_repository *repo,
+	git_commit *notes_commit,
+	const git_oid *oid);
+
+/**
+ * Get the note author
+ *
+ * @param note the note
+ * @return the author
+ */
+GIT_EXTERN(const git_signature *) git_note_author(const git_note *note);
+
+/**
+ * Get the note committer
+ *
+ * @param note the note
+ * @return the committer
+ */
+GIT_EXTERN(const git_signature *) git_note_committer(const git_note *note);
+
+
+/**
+ * Get the note message
+ *
+ * @param note the note
+ * @return the note message
+ */
+GIT_EXTERN(const char *) git_note_message(const git_note *note);
+
+
+/**
+ * Get the note object's id
+ *
+ * @param note the note
+ * @return the note object's id
+ */
+GIT_EXTERN(const git_oid *) git_note_id(const git_note *note);
+
+/**
+ * Add a note for an object
+ *
+ * @param out pointer to store the OID (optional); NULL in case of error
+ * @param repo repository where to store the note
+ * @param notes_ref canonical name of the reference to use (optional);
+ *					defaults to "refs/notes/commits"
+ * @param author signature of the notes commit author
+ * @param committer signature of the notes commit committer
+ * @param oid OID of the git object to decorate
+ * @param note Content of the note to add for object oid
+ * @param force Overwrite existing note
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_note_create(
+	git_oid *out,
+	git_repository *repo,
+	const char *notes_ref,
+	const git_signature *author,
+	const git_signature *committer,
+	const git_oid *oid,
+	const char *note,
+	int force);
+
+/**
+ * Add a note for an object from a commit
+ *
+ * This function will create a notes commit for a given object,
+ * the commit is a dangling commit, no reference is created.
+ *
+ * @param notes_commit_out pointer to store the commit (optional);
+ *					NULL in case of error
+ * @param notes_blob_out a point to the id of a note blob (optional)
+ * @param repo repository where the note will live
+ * @param parent Pointer to parent note
+ *					or NULL if this shall start a new notes tree
+ * @param author signature of the notes commit author
+ * @param committer signature of the notes commit committer
+ * @param oid OID of the git object to decorate
+ * @param note Content of the note to add for object oid
+ * @param allow_note_overwrite Overwrite existing note
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_note_commit_create(
+	git_oid *notes_commit_out,
+	git_oid *notes_blob_out,
+	git_repository *repo,
+	git_commit *parent,
+	const git_signature *author,
+	const git_signature *committer,
+	const git_oid *oid,
+	const char *note,
+	int allow_note_overwrite);
+
+/**
+ * Remove the note for an object
+ *
+ * @param repo repository where the note lives
+ * @param notes_ref canonical name of the reference to use (optional);
+ *					defaults to "refs/notes/commits"
+ * @param author signature of the notes commit author
+ * @param committer signature of the notes commit committer
+ * @param oid OID of the git object to remove the note from
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_note_remove(
+	git_repository *repo,
+	const char *notes_ref,
+	const git_signature *author,
+	const git_signature *committer,
+	const git_oid *oid);
+
+/**
+ * Remove the note for an object
+ *
+ * @param notes_commit_out pointer to store the new notes commit (optional);
+ *					NULL in case of error.
+ *					When removing a note a new tree containing all notes
+ *					sans the note to be removed is created and a new commit
+ *					pointing to that tree is also created.
+ *					In the case where the resulting tree is an empty tree
+ *					a new commit pointing to this empty tree will be returned.
+ * @param repo repository where the note lives
+ * @param notes_commit a pointer to the notes commit object
+ * @param author signature of the notes commit author
+ * @param committer signature of the notes commit committer
+ * @param oid OID of the git object to remove the note from
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_note_commit_remove(
+		git_oid *notes_commit_out,
+		git_repository *repo,
+		git_commit *notes_commit,
+		const git_signature *author,
+		const git_signature *committer,
+		const git_oid *oid);
+
+/**
+ * Free a git_note object
+ *
+ * @param note git_note object
+ */
+GIT_EXTERN(void) git_note_free(git_note *note);
+
+/**
+ * Get the default notes reference for a repository
+ *
+ * @param out buffer in which to store the name of the default notes reference
+ * @param repo The Git repository
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_note_default_ref(git_buf *out, git_repository *repo);
+
+/**
+ * Loop over all the notes within a specified namespace
+ * and issue a callback for each one.
+ *
+ * @param repo Repository where to find the notes.
+ *
+ * @param notes_ref Reference to read from (optional); defaults to
+ *        "refs/notes/commits".
+ *
+ * @param note_cb Callback to invoke per found annotation.  Return non-zero
+ *        to stop looping.
+ *
+ * @param payload Extra parameter to callback function.
+ *
+ * @return 0 on success, non-zero callback return value, or error code
+ */
+GIT_EXTERN(int) git_note_foreach(
+	git_repository *repo,
+	const char *notes_ref,
+	git_note_foreach_cb note_cb,
+	void *payload);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/object.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/object.h b/vendor/libgit2-sys/libgit2/include/git2/object.h
new file mode 100644
index 0000000..a798c9d
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/object.h
@@ -0,0 +1,242 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_object_h__
+#define INCLUDE_git_object_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+#include "buffer.h"
+
+/**
+ * @file git2/object.h
+ * @brief Git revision object management routines
+ * @defgroup git_object Git revision object management routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Lookup a reference to one of the objects in a repository.
+ *
+ * The generated reference is owned by the repository and
+ * should be closed with the `git_object_free` method
+ * instead of free'd manually.
+ *
+ * The 'type' parameter must match the type of the object
+ * in the odb; the method will fail otherwise.
+ * The special value 'GIT_OBJ_ANY' may be passed to let
+ * the method guess the object's type.
+ *
+ * @param object pointer to the looked-up object
+ * @param repo the repository to look up the object
+ * @param id the unique identifier for the object
+ * @param type the type of the object
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_object_lookup(
+		git_object **object,
+		git_repository *repo,
+		const git_oid *id,
+		git_otype type);
+
+/**
+ * Lookup a reference to one of the objects in a repository,
+ * given a prefix of its identifier (short id).
+ *
+ * The object obtained will be so that its identifier
+ * matches the first 'len' hexadecimal characters
+ * (packets of 4 bits) of the given 'id'.
+ * 'len' must be at least GIT_OID_MINPREFIXLEN, and
+ * long enough to identify a unique object matching
+ * the prefix; otherwise the method will fail.
+ *
+ * The generated reference is owned by the repository and
+ * should be closed with the `git_object_free` method
+ * instead of free'd manually.
+ *
+ * The 'type' parameter must match the type of the object
+ * in the odb; the method will fail otherwise.
+ * The special value 'GIT_OBJ_ANY' may be passed to let
+ * the method guess the object's type.
+ *
+ * @param object_out pointer where to store the looked-up object
+ * @param repo the repository to look up the object
+ * @param id a short identifier for the object
+ * @param len the length of the short identifier
+ * @param type the type of the object
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_object_lookup_prefix(
+		git_object **object_out,
+		git_repository *repo,
+		const git_oid *id,
+		size_t len,
+		git_otype type);
+
+
+/**
+ * Lookup an object that represents a tree entry.
+ *
+ * @param out buffer that receives a pointer to the object (which must be freed
+ *            by the caller)
+ * @param treeish root object that can be peeled to a tree
+ * @param path relative path from the root object to the desired object
+ * @param type type of object desired
+ * @return 0 on success, or an error code
+ */
+GIT_EXTERN(int) git_object_lookup_bypath(
+		git_object **out,
+		const git_object *treeish,
+		const char *path,
+		git_otype type);
+
+/**
+ * Get the id (SHA1) of a repository object
+ *
+ * @param obj the repository object
+ * @return the SHA1 id
+ */
+GIT_EXTERN(const git_oid *) git_object_id(const git_object *obj);
+
+/**
+ * Get a short abbreviated OID string for the object
+ *
+ * This starts at the "core.abbrev" length (default 7 characters) and
+ * iteratively extends to a longer string if that length is ambiguous.
+ * The result will be unambiguous (at least until new objects are added to
+ * the repository).
+ *
+ * @param out Buffer to write string into
+ * @param obj The object to get an ID for
+ * @return 0 on success, <0 for error
+ */
+GIT_EXTERN(int) git_object_short_id(git_buf *out, const git_object *obj);
+
+/**
+ * Get the object type of an object
+ *
+ * @param obj the repository object
+ * @return the object's type
+ */
+GIT_EXTERN(git_otype) git_object_type(const git_object *obj);
+
+/**
+ * Get the repository that owns this object
+ *
+ * Freeing or calling `git_repository_close` on the
+ * returned pointer will invalidate the actual object.
+ *
+ * Any other operation may be run on the repository without
+ * affecting the object.
+ *
+ * @param obj the object
+ * @return the repository who owns this object
+ */
+GIT_EXTERN(git_repository *) git_object_owner(const git_object *obj);
+
+/**
+ * Close an open object
+ *
+ * This method instructs the library to close an existing
+ * object; note that git_objects are owned and cached by the repository
+ * so the object may or may not be freed after this library call,
+ * depending on how aggressive is the caching mechanism used
+ * by the repository.
+ *
+ * IMPORTANT:
+ * It *is* necessary to call this method when you stop using
+ * an object. Failure to do so will cause a memory leak.
+ *
+ * @param object the object to close
+ */
+GIT_EXTERN(void) git_object_free(git_object *object);
+
+/**
+ * Convert an object type to its string representation.
+ *
+ * The result is a pointer to a string in static memory and
+ * should not be free()'ed.
+ *
+ * @param type object type to convert.
+ * @return the corresponding string representation.
+ */
+GIT_EXTERN(const char *) git_object_type2string(git_otype type);
+
+/**
+ * Convert a string object type representation to it's git_otype.
+ *
+ * @param str the string to convert.
+ * @return the corresponding git_otype.
+ */
+GIT_EXTERN(git_otype) git_object_string2type(const char *str);
+
+/**
+ * Determine if the given git_otype is a valid loose object type.
+ *
+ * @param type object type to test.
+ * @return true if the type represents a valid loose object type,
+ * false otherwise.
+ */
+GIT_EXTERN(int) git_object_typeisloose(git_otype type);
+
+/**
+ * Get the size in bytes for the structure which
+ * acts as an in-memory representation of any given
+ * object type.
+ *
+ * For all the core types, this would the equivalent
+ * of calling `sizeof(git_commit)` if the core types
+ * were not opaque on the external API.
+ *
+ * @param type object type to get its size
+ * @return size in bytes of the object
+ */
+GIT_EXTERN(size_t) git_object__size(git_otype type);
+
+/**
+ * Recursively peel an object until an object of the specified type is met.
+ *
+ * If the query cannot be satisfied due to the object model,
+ * GIT_EINVALIDSPEC will be returned (e.g. trying to peel a blob to a
+ * tree).
+ *
+ * If you pass `GIT_OBJ_ANY` as the target type, then the object will
+ * be peeled until the type changes. A tag will be peeled until the
+ * referenced object is no longer a tag, and a commit will be peeled
+ * to a tree. Any other object type will return GIT_EINVALIDSPEC.
+ *
+ * If peeling a tag we discover an object which cannot be peeled to
+ * the target type due to the object model, GIT_EPEEL will be
+ * returned.
+ *
+ * You must free the returned object.
+ *
+ * @param peeled Pointer to the peeled git_object
+ * @param object The object to be processed
+ * @param target_type The type of the requested object (a GIT_OBJ_ value)
+ * @return 0 on success, GIT_EINVALIDSPEC, GIT_EPEEL, or an error code
+ */
+GIT_EXTERN(int) git_object_peel(
+	git_object **peeled,
+	const git_object *object,
+	git_otype target_type);
+
+/**
+ * Create an in-memory copy of a Git object. The copy must be
+ * explicitly free'd or it will leak.
+ *
+ * @param dest Pointer to store the copy of the object
+ * @param source Original object to copy
+ */
+GIT_EXTERN(int) git_object_dup(git_object **dest, git_object *source);
+
+/** @} */
+GIT_END_DECL
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/odb.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/odb.h b/vendor/libgit2-sys/libgit2/include/git2/odb.h
new file mode 100644
index 0000000..006a75b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/odb.h
@@ -0,0 +1,548 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_odb_h__
+#define INCLUDE_git_odb_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+#include "oidarray.h"
+
+/**
+ * @file git2/odb.h
+ * @brief Git object database routines
+ * @defgroup git_odb Git object database routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Function type for callbacks from git_odb_foreach.
+ */
+typedef int (*git_odb_foreach_cb)(const git_oid *id, void *payload);
+
+/**
+ * Create a new object database with no backends.
+ *
+ * Before the ODB can be used for read/writing, a custom database
+ * backend must be manually added using `git_odb_add_backend()`
+ *
+ * @param out location to store the database pointer, if opened.
+ *			Set to NULL if the open failed.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_odb_new(git_odb **out);
+
+/**
+ * Create a new object database and automatically add
+ * the two default backends:
+ *
+ *	- git_odb_backend_loose: read and write loose object files
+ *		from disk, assuming `objects_dir` as the Objects folder
+ *
+ *	- git_odb_backend_pack: read objects from packfiles,
+ *		assuming `objects_dir` as the Objects folder which
+ *		contains a 'pack/' folder with the corresponding data
+ *
+ * @param out location to store the database pointer, if opened.
+ *			Set to NULL if the open failed.
+ * @param objects_dir path of the backends' "objects" directory.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_odb_open(git_odb **out, const char *objects_dir);
+
+/**
+ * Add an on-disk alternate to an existing Object DB.
+ *
+ * Note that the added path must point to an `objects`, not
+ * to a full repository, to use it as an alternate store.
+ *
+ * Alternate backends are always checked for objects *after*
+ * all the main backends have been exhausted.
+ *
+ * Writing is disabled on alternate backends.
+ *
+ * @param odb database to add the backend to
+ * @param path path to the objects folder for the alternate
+ * @return 0 on success; error code otherwise
+ */
+GIT_EXTERN(int) git_odb_add_disk_alternate(git_odb *odb, const char *path);
+
+/**
+ * Close an open object database.
+ *
+ * @param db database pointer to close. If NULL no action is taken.
+ */
+GIT_EXTERN(void) git_odb_free(git_odb *db);
+
+/**
+ * Read an object from the database.
+ *
+ * This method queries all available ODB backends
+ * trying to read the given OID.
+ *
+ * The returned object is reference counted and
+ * internally cached, so it should be closed
+ * by the user once it's no longer in use.
+ *
+ * @param out pointer where to store the read object
+ * @param db database to search for the object in.
+ * @param id identity of the object to read.
+ * @return
+ * - 0 if the object was read;
+ * - GIT_ENOTFOUND if the object is not in the database.
+ */
+GIT_EXTERN(int) git_odb_read(git_odb_object **out, git_odb *db, const git_oid *id);
+
+/**
+ * Read an object from the database, given a prefix
+ * of its identifier.
+ *
+ * This method queries all available ODB backends
+ * trying to match the 'len' first hexadecimal
+ * characters of the 'short_id'.
+ * The remaining (GIT_OID_HEXSZ-len)*4 bits of
+ * 'short_id' must be 0s.
+ * 'len' must be at least GIT_OID_MINPREFIXLEN,
+ * and the prefix must be long enough to identify
+ * a unique object in all the backends; the
+ * method will fail otherwise.
+ *
+ * The returned object is reference counted and
+ * internally cached, so it should be closed
+ * by the user once it's no longer in use.
+ *
+ * @param out pointer where to store the read object
+ * @param db database to search for the object in.
+ * @param short_id a prefix of the id of the object to read.
+ * @param len the length of the prefix
+ * @return
+ * - 0 if the object was read;
+ * - GIT_ENOTFOUND if the object is not in the database.
+ * - GIT_EAMBIGUOUS if the prefix is ambiguous (several objects match the prefix)
+ */
+GIT_EXTERN(int) git_odb_read_prefix(git_odb_object **out, git_odb *db, const git_oid *short_id, size_t len);
+
+/**
+ * Read the header of an object from the database, without
+ * reading its full contents.
+ *
+ * The header includes the length and the type of an object.
+ *
+ * Note that most backends do not support reading only the header
+ * of an object, so the whole object will be read and then the
+ * header will be returned.
+ *
+ * @param len_out pointer where to store the length
+ * @param type_out pointer where to store the type
+ * @param db database to search for the object in.
+ * @param id identity of the object to read.
+ * @return
+ * - 0 if the object was read;
+ * - GIT_ENOTFOUND if the object is not in the database.
+ */
+GIT_EXTERN(int) git_odb_read_header(size_t *len_out, git_otype *type_out, git_odb *db, const git_oid *id);
+
+/**
+ * Determine if the given object can be found in the object database.
+ *
+ * @param db database to be searched for the given object.
+ * @param id the object to search for.
+ * @return
+ * - 1, if the object was found
+ * - 0, otherwise
+ */
+GIT_EXTERN(int) git_odb_exists(git_odb *db, const git_oid *id);
+
+/**
+ * Determine if an object can be found in the object database by an
+ * abbreviated object ID.
+ *
+ * @param out The full OID of the found object if just one is found.
+ * @param db The database to be searched for the given object.
+ * @param short_id A prefix of the id of the object to read.
+ * @param len The length of the prefix.
+ * @return 0 if found, GIT_ENOTFOUND if not found, GIT_EAMBIGUOUS if multiple
+ *         matches were found, other value < 0 if there was a read error.
+ */
+GIT_EXTERN(int) git_odb_exists_prefix(
+	git_oid *out, git_odb *db, const git_oid *short_id, size_t len);
+
+/**
+ * The information about object IDs to query in `git_odb_expand_ids`,
+ * which will be populated upon return.
+ */
+typedef struct git_odb_expand_id {
+	/** The object ID to expand */
+	git_oid id;
+
+	/**
+	 * The length of the object ID (in nibbles, or packets of 4 bits; the
+	 * number of hex characters)
+	 * */
+	unsigned short length;
+
+	/**
+	 * The (optional) type of the object to search for; leave as `0` or set
+	 * to `GIT_OBJ_ANY` to query for any object matching the ID.
+	 */
+	git_otype type;
+} git_odb_expand_id;
+
+/**
+ * Determine if one or more objects can be found in the object database
+ * by their abbreviated object ID and type.  The given array will be
+ * updated in place:  for each abbreviated ID that is unique in the
+ * database, and of the given type (if specified), the full object ID,
+ * object ID length (`GIT_OID_HEXSZ`) and type will be written back to
+ * the array.  For IDs that are not found (or are ambiguous), the
+ * array entry will be zeroed.
+ *
+ * Note that since this function operates on multiple objects, the
+ * underlying database will not be asked to be reloaded if an object is
+ * not found (which is unlike other object database operations.)
+ *
+ * @param db The database to be searched for the given objects.
+ * @param ids An array of short object IDs to search for
+ * @param count The length of the `ids` array
+ * @return 0 on success or an error code on failure
+ */
+GIT_EXTERN(int) git_odb_expand_ids(
+	git_odb *db,
+	git_odb_expand_id *ids,
+	size_t count);
+
+/**
+ * Refresh the object database to load newly added files.
+ *
+ * If the object databases have changed on disk while the library
+ * is running, this function will force a reload of the underlying
+ * indexes.
+ *
+ * Use this function when you're confident that an external
+ * application has tampered with the ODB.
+ *
+ * NOTE that it is not necessary to call this function at all. The
+ * library will automatically attempt to refresh the ODB
+ * when a lookup fails, to see if the looked up object exists
+ * on disk but hasn't been loaded yet.
+ *
+ * @param db database to refresh
+ * @return 0 on success, error code otherwise
+ */
+GIT_EXTERN(int) git_odb_refresh(struct git_odb *db);
+
+/**
+ * List all objects available in the database
+ *
+ * The callback will be called for each object available in the
+ * database. Note that the objects are likely to be returned in the index
+ * order, which would make accessing the objects in that order inefficient.
+ * Return a non-zero value from the callback to stop looping.
+ *
+ * @param db database to use
+ * @param cb the callback to call for each object
+ * @param payload data to pass to the callback
+ * @return 0 on success, non-zero callback return value, or error code
+ */
+GIT_EXTERN(int) git_odb_foreach(git_odb *db, git_odb_foreach_cb cb, void *payload);
+
+/**
+ * Write an object directly into the ODB
+ *
+ * This method writes a full object straight into the ODB.
+ * For most cases, it is preferred to write objects through a write
+ * stream, which is both faster and less memory intensive, specially
+ * for big objects.
+ *
+ * This method is provided for compatibility with custom backends
+ * which are not able to support streaming writes
+ *
+ * @param out pointer to store the OID result of the write
+ * @param odb object database where to store the object
+ * @param data buffer with the data to store
+ * @param len size of the buffer
+ * @param type type of the data to store
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_odb_write(git_oid *out, git_odb *odb, const void *data, size_t len, git_otype type);
+
+/**
+ * Open a stream to write an object into the ODB
+ *
+ * The type and final length of the object must be specified
+ * when opening the stream.
+ *
+ * The returned stream will be of type `GIT_STREAM_WRONLY`, and it
+ * won't be effective until `git_odb_stream_finalize_write` is called
+ * and returns without an error
+ *
+ * The stream must always be freed when done with `git_odb_stream_free` or
+ * will leak memory.
+ *
+ * @see git_odb_stream
+ *
+ * @param out pointer where to store the stream
+ * @param db object database where the stream will write
+ * @param size final size of the object that will be written
+ * @param type type of the object that will be written
+ * @return 0 if the stream was created; error code otherwise
+ */
+GIT_EXTERN(int) git_odb_open_wstream(git_odb_stream **out, git_odb *db, git_off_t size, git_otype type);
+
+/**
+ * Write to an odb stream
+ *
+ * This method will fail if the total number of received bytes exceeds the
+ * size declared with `git_odb_open_wstream()`
+ *
+ * @param stream the stream
+ * @param buffer the data to write
+ * @param len the buffer's length
+ * @return 0 if the write succeeded; error code otherwise
+ */
+GIT_EXTERN(int) git_odb_stream_write(git_odb_stream *stream, const char *buffer, size_t len);
+
+/**
+ * Finish writing to an odb stream
+ *
+ * The object will take its final name and will be available to the
+ * odb.
+ *
+ * This method will fail if the total number of received bytes
+ * differs from the size declared with `git_odb_open_wstream()`
+ *
+ * @param out pointer to store the resulting object's id
+ * @param stream the stream
+ * @return 0 on success; an error code otherwise
+ */
+GIT_EXTERN(int) git_odb_stream_finalize_write(git_oid *out, git_odb_stream *stream);
+
+/**
+ * Read from an odb stream
+ *
+ * Most backends don't implement streaming reads
+ */
+GIT_EXTERN(int) git_odb_stream_read(git_odb_stream *stream, char *buffer, size_t len);
+
+/**
+ * Free an odb stream
+ *
+ * @param stream the stream to free
+ */
+GIT_EXTERN(void) git_odb_stream_free(git_odb_stream *stream);
+
+/**
+ * Open a stream to read an object from the ODB
+ *
+ * Note that most backends do *not* support streaming reads
+ * because they store their objects as compressed/delta'ed blobs.
+ *
+ * It's recommended to use `git_odb_read` instead, which is
+ * assured to work on all backends.
+ *
+ * The returned stream will be of type `GIT_STREAM_RDONLY` and
+ * will have the following methods:
+ *
+ *		- stream->read: read `n` bytes from the stream
+ *		- stream->free: free the stream
+ *
+ * The stream must always be free'd or will leak memory.
+ *
+ * @see git_odb_stream
+ *
+ * @param out pointer where to store the stream
+ * @param len pointer where to store the length of the object
+ * @param type pointer where to store the type of the object
+ * @param db object database where the stream will read from
+ * @param oid oid of the object the stream will read from
+ * @return 0 if the stream was created; error code otherwise
+ */
+GIT_EXTERN(int) git_odb_open_rstream(
+	git_odb_stream **out,
+	size_t *len,
+	git_otype *type,
+	git_odb *db,
+	const git_oid *oid);
+
+/**
+ * Open a stream for writing a pack file to the ODB.
+ *
+ * If the ODB layer understands pack files, then the given
+ * packfile will likely be streamed directly to disk (and a
+ * corresponding index created).  If the ODB layer does not
+ * understand pack files, the objects will be stored in whatever
+ * format the ODB layer uses.
+ *
+ * @see git_odb_writepack
+ *
+ * @param out pointer to the writepack functions
+ * @param db object database where the stream will read from
+ * @param progress_cb function to call with progress information.
+ * Be aware that this is called inline with network and indexing operations,
+ * so performance may be affected.
+ * @param progress_payload payload for the progress callback
+ */
+GIT_EXTERN(int) git_odb_write_pack(
+	git_odb_writepack **out,
+	git_odb *db,
+	git_transfer_progress_cb progress_cb,
+	void *progress_payload);
+
+/**
+ * Determine the object-ID (sha1 hash) of a data buffer
+ *
+ * The resulting SHA-1 OID will be the identifier for the data
+ * buffer as if the data buffer it were to written to the ODB.
+ *
+ * @param out the resulting object-ID.
+ * @param data data to hash
+ * @param len size of the data
+ * @param type of the data to hash
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_odb_hash(git_oid *out, const void *data, size_t len, git_otype type);
+
+/**
+ * Read a file from disk and fill a git_oid with the object id
+ * that the file would have if it were written to the Object
+ * Database as an object of the given type (w/o applying filters).
+ * Similar functionality to git.git's `git hash-object` without
+ * the `-w` flag, however, with the --no-filters flag.
+ * If you need filters, see git_repository_hashfile.
+ *
+ * @param out oid structure the result is written into.
+ * @param path file to read and determine object id for
+ * @param type the type of the object that will be hashed
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_odb_hashfile(git_oid *out, const char *path, git_otype type);
+
+/**
+ * Create a copy of an odb_object
+ *
+ * The returned copy must be manually freed with `git_odb_object_free`.
+ * Note that because of an implementation detail, the returned copy will be
+ * the same pointer as `source`: the object is internally refcounted, so the
+ * copy still needs to be freed twice.
+ *
+ * @param dest pointer where to store the copy
+ * @param source object to copy
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_odb_object_dup(git_odb_object **dest, git_odb_object *source);
+
+/**
+ * Close an ODB object
+ *
+ * This method must always be called once a `git_odb_object` is no
+ * longer needed, otherwise memory will leak.
+ *
+ * @param object object to close
+ */
+GIT_EXTERN(void) git_odb_object_free(git_odb_object *object);
+
+/**
+ * Return the OID of an ODB object
+ *
+ * This is the OID from which the object was read from
+ *
+ * @param object the object
+ * @return a pointer to the OID
+ */
+GIT_EXTERN(const git_oid *) git_odb_object_id(git_odb_object *object);
+
+/**
+ * Return the data of an ODB object
+ *
+ * This is the uncompressed, raw data as read from the ODB,
+ * without the leading header.
+ *
+ * This pointer is owned by the object and shall not be free'd.
+ *
+ * @param object the object
+ * @return a pointer to the data
+ */
+GIT_EXTERN(const void *) git_odb_object_data(git_odb_object *object);
+
+/**
+ * Return the size of an ODB object
+ *
+ * This is the real size of the `data` buffer, not the
+ * actual size of the object.
+ *
+ * @param object the object
+ * @return the size
+ */
+GIT_EXTERN(size_t) git_odb_object_size(git_odb_object *object);
+
+/**
+ * Return the type of an ODB object
+ *
+ * @param object the object
+ * @return the type
+ */
+GIT_EXTERN(git_otype) git_odb_object_type(git_odb_object *object);
+
+/**
+ * Add a custom backend to an existing Object DB
+ *
+ * The backends are checked in relative ordering, based on the
+ * value of the `priority` parameter.
+ *
+ * Read <sys/odb_backend.h> for more information.
+ *
+ * @param odb database to add the backend to
+ * @param backend pointer to a git_odb_backend instance
+ * @param priority Value for ordering the backends queue
+ * @return 0 on success; error code otherwise
+ */
+GIT_EXTERN(int) git_odb_add_backend(git_odb *odb, git_odb_backend *backend, int priority);
+
+/**
+ * Add a custom backend to an existing Object DB; this
+ * backend will work as an alternate.
+ *
+ * Alternate backends are always checked for objects *after*
+ * all the main backends have been exhausted.
+ *
+ * The backends are checked in relative ordering, based on the
+ * value of the `priority` parameter.
+ *
+ * Writing is disabled on alternate backends.
+ *
+ * Read <sys/odb_backend.h> for more information.
+ *
+ * @param odb database to add the backend to
+ * @param backend pointer to a git_odb_backend instance
+ * @param priority Value for ordering the backends queue
+ * @return 0 on success; error code otherwise
+ */
+GIT_EXTERN(int) git_odb_add_alternate(git_odb *odb, git_odb_backend *backend, int priority);
+
+/**
+ * Get the number of ODB backend objects
+ *
+ * @param odb object database
+ * @return number of backends in the ODB
+ */
+GIT_EXTERN(size_t) git_odb_num_backends(git_odb *odb);
+
+/**
+ * Lookup an ODB backend object by index
+ *
+ * @param out output pointer to ODB backend at pos
+ * @param odb object database
+ * @param pos index into object database backend list
+ * @return 0 on success; GIT_ENOTFOUND if pos is invalid; other errors < 0
+ */
+GIT_EXTERN(int) git_odb_get_backend(git_odb_backend **out, git_odb *odb, size_t pos);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/odb_backend.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/odb_backend.h b/vendor/libgit2-sys/libgit2/include/git2/odb_backend.h
new file mode 100644
index 0000000..9199538
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/odb_backend.h
@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_odb_backend_h__
+#define INCLUDE_git_odb_backend_h__
+
+#include "common.h"
+#include "types.h"
+
+/**
+ * @file git2/backend.h
+ * @brief Git custom backend functions
+ * @defgroup git_odb Git object database routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/*
+ * Constructors for in-box ODB backends.
+ */
+
+/**
+ * Create a backend for the packfiles.
+ *
+ * @param out location to store the odb backend pointer
+ * @param objects_dir the Git repository's objects directory
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_odb_backend_pack(git_odb_backend **out, const char *objects_dir);
+
+/**
+ * Create a backend for loose objects
+ *
+ * @param out location to store the odb backend pointer
+ * @param objects_dir the Git repository's objects directory
+ * @param compression_level zlib compression level to use
+ * @param do_fsync whether to do an fsync() after writing
+ * @param dir_mode permissions to use creating a directory or 0 for defaults
+ * @param file_mode permissions to use creating a file or 0 for defaults
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_odb_backend_loose(
+	git_odb_backend **out,
+	const char *objects_dir,
+	int compression_level,
+	int do_fsync,
+	unsigned int dir_mode,
+	unsigned int file_mode);
+
+/**
+ * Create a backend out of a single packfile
+ *
+ * This can be useful for inspecting the contents of a single
+ * packfile.
+ *
+ * @param out location to store the odb backend pointer
+ * @param index_file path to the packfile's .idx file
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_odb_backend_one_pack(git_odb_backend **out, const char *index_file);
+
+/** Streaming mode */
+typedef enum {
+	GIT_STREAM_RDONLY = (1 << 1),
+	GIT_STREAM_WRONLY = (1 << 2),
+	GIT_STREAM_RW = (GIT_STREAM_RDONLY | GIT_STREAM_WRONLY),
+} git_odb_stream_t;
+
+/**
+ * A stream to read/write from a backend.
+ *
+ * This represents a stream of data being written to or read from a
+ * backend. When writing, the frontend functions take care of
+ * calculating the object's id and all `finalize_write` needs to do is
+ * store the object with the id it is passed.
+ */
+struct git_odb_stream {
+	git_odb_backend *backend;
+	unsigned int mode;
+	void *hash_ctx;
+
+	git_off_t declared_size;
+	git_off_t received_bytes;
+
+	/**
+	 * Write at most `len` bytes into `buffer` and advance the stream.
+	 */
+	int (*read)(git_odb_stream *stream, char *buffer, size_t len);
+
+	/**
+	 * Write `len` bytes from `buffer` into the stream.
+	 */
+	int (*write)(git_odb_stream *stream, const char *buffer, size_t len);
+
+	/**
+	 * Store the contents of the stream as an object with the id
+	 * specified in `oid`.
+	 *
+	 * This method might not be invoked if:
+	 * - an error occurs earlier with the `write` callback,
+	 * - the object referred to by `oid` already exists in any backend, or
+	 * - the final number of received bytes differs from the size declared
+	 *   with `git_odb_open_wstream()`
+	 */
+	int (*finalize_write)(git_odb_stream *stream, const git_oid *oid);
+
+	/**
+	 * Free the stream's memory.
+	 *
+	 * This method might be called without a call to `finalize_write` if
+	 * an error occurs or if the object is already present in the ODB.
+	 */
+	void (*free)(git_odb_stream *stream);
+};
+
+/** A stream to write a pack file to the ODB */
+struct git_odb_writepack {
+	git_odb_backend *backend;
+
+	int (*append)(git_odb_writepack *writepack, const void *data, size_t size, git_transfer_progress *stats);
+	int (*commit)(git_odb_writepack *writepack, git_transfer_progress *stats);
+	void (*free)(git_odb_writepack *writepack);
+};
+
+GIT_END_DECL
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/oid.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/oid.h b/vendor/libgit2-sys/libgit2/include/git2/oid.h
new file mode 100644
index 0000000..aaa678cc
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/oid.h
@@ -0,0 +1,268 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_oid_h__
+#define INCLUDE_git_oid_h__
+
+#include "common.h"
+#include "types.h"
+
+/**
+ * @file git2/oid.h
+ * @brief Git object id routines
+ * @defgroup git_oid Git object id routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/** Size (in bytes) of a raw/binary oid */
+#define GIT_OID_RAWSZ 20
+
+/** Size (in bytes) of a hex formatted oid */
+#define GIT_OID_HEXSZ (GIT_OID_RAWSZ * 2)
+
+/** Minimum length (in number of hex characters,
+ * i.e. packets of 4 bits) of an oid prefix */
+#define GIT_OID_MINPREFIXLEN 4
+
+/** Unique identity of any object (commit, tree, blob, tag). */
+typedef struct git_oid {
+	/** raw binary formatted id */
+	unsigned char id[GIT_OID_RAWSZ];
+} git_oid;
+
+/**
+ * Parse a hex formatted object id into a git_oid.
+ *
+ * @param out oid structure the result is written into.
+ * @param str input hex string; must be pointing at the start of
+ *		the hex sequence and have at least the number of bytes
+ *		needed for an oid encoded in hex (40 bytes).
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_oid_fromstr(git_oid *out, const char *str);
+
+/**
+ * Parse a hex formatted null-terminated string into a git_oid.
+ *
+ * @param out oid structure the result is written into.
+ * @param str input hex string; must be null-terminated.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_oid_fromstrp(git_oid *out, const char *str);
+
+/**
+ * Parse N characters of a hex formatted object id into a git_oid.
+ *
+ * If N is odd, the last byte's high nibble will be read in and the
+ * low nibble set to zero.
+ *
+ * @param out oid structure the result is written into.
+ * @param str input hex string of at least size `length`
+ * @param length length of the input string
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_oid_fromstrn(git_oid *out, const char *str, size_t length);
+
+/**
+ * Copy an already raw oid into a git_oid structure.
+ *
+ * @param out oid structure the result is written into.
+ * @param raw the raw input bytes to be copied.
+ */
+GIT_EXTERN(void) git_oid_fromraw(git_oid *out, const unsigned char *raw);
+
+/**
+ * Format a git_oid into a hex string.
+ *
+ * @param out output hex string; must be pointing at the start of
+ *		the hex sequence and have at least the number of bytes
+ *		needed for an oid encoded in hex (40 bytes). Only the
+ *		oid digits are written; a '\\0' terminator must be added
+ *		by the caller if it is required.
+ * @param id oid structure to format.
+ */
+GIT_EXTERN(void) git_oid_fmt(char *out, const git_oid *id);
+
+/**
+ * Format a git_oid into a partial hex string.
+ *
+ * @param out output hex string; you say how many bytes to write.
+ *		If the number of bytes is > GIT_OID_HEXSZ, extra bytes
+ *		will be zeroed; if not, a '\0' terminator is NOT added.
+ * @param n number of characters to write into out string
+ * @param id oid structure to format.
+ */
+GIT_EXTERN(void) git_oid_nfmt(char *out, size_t n, const git_oid *id);
+
+/**
+ * Format a git_oid into a loose-object path string.
+ *
+ * The resulting string is "aa/...", where "aa" is the first two
+ * hex digits of the oid and "..." is the remaining 38 digits.
+ *
+ * @param out output hex string; must be pointing at the start of
+ *		the hex sequence and have at least the number of bytes
+ *		needed for an oid encoded in hex (41 bytes). Only the
+ *		oid digits are written; a '\\0' terminator must be added
+ *		by the caller if it is required.
+ * @param id oid structure to format.
+ */
+GIT_EXTERN(void) git_oid_pathfmt(char *out, const git_oid *id);
+
+/**
+ * Format a git_oid into a statically allocated c-string.
+ *
+ * The c-string is owned by the library and should not be freed
+ * by the user. If libgit2 is built with thread support, the string
+ * will be stored in TLS (i.e. one buffer per thread) to allow for
+ * concurrent calls of the function.
+ *
+ * @param oid The oid structure to format
+ * @return the c-string
+ */
+GIT_EXTERN(char *) git_oid_tostr_s(const git_oid *oid);
+
+/**
+ * Format a git_oid into a buffer as a hex format c-string.
+ *
+ * If the buffer is smaller than GIT_OID_HEXSZ+1, then the resulting
+ * oid c-string will be truncated to n-1 characters (but will still be
+ * NUL-byte terminated).
+ *
+ * If there are any input parameter errors (out == NULL, n == 0, oid ==
+ * NULL), then a pointer to an empty string is returned, so that the
+ * return value can always be printed.
+ *
+ * @param out the buffer into which the oid string is output.
+ * @param n the size of the out buffer.
+ * @param id the oid structure to format.
+ * @return the out buffer pointer, assuming no input parameter
+ *			errors, otherwise a pointer to an empty string.
+ */
+GIT_EXTERN(char *) git_oid_tostr(char *out, size_t n, const git_oid *id);
+
+/**
+ * Copy an oid from one structure to another.
+ *
+ * @param out oid structure the result is written into.
+ * @param src oid structure to copy from.
+ */
+GIT_EXTERN(void) git_oid_cpy(git_oid *out, const git_oid *src);
+
+/**
+ * Compare two oid structures.
+ *
+ * @param a first oid structure.
+ * @param b second oid structure.
+ * @return <0, 0, >0 if a < b, a == b, a > b.
+ */
+GIT_EXTERN(int) git_oid_cmp(const git_oid *a, const git_oid *b);
+
+/**
+ * Compare two oid structures for equality
+ *
+ * @param a first oid structure.
+ * @param b second oid structure.
+ * @return true if equal, false otherwise
+ */
+GIT_EXTERN(int) git_oid_equal(const git_oid *a, const git_oid *b);
+
+/**
+ * Compare the first 'len' hexadecimal characters (packets of 4 bits)
+ * of two oid structures.
+ *
+ * @param a first oid structure.
+ * @param b second oid structure.
+ * @param len the number of hex chars to compare
+ * @return 0 in case of a match
+ */
+GIT_EXTERN(int) git_oid_ncmp(const git_oid *a, const git_oid *b, size_t len);
+
+/**
+ * Check if an oid equals an hex formatted object id.
+ *
+ * @param id oid structure.
+ * @param str input hex string of an object id.
+ * @return 0 in case of a match, -1 otherwise.
+ */
+GIT_EXTERN(int) git_oid_streq(const git_oid *id, const char *str);
+
+/**
+ * Compare an oid to an hex formatted object id.
+ *
+ * @param id oid structure.
+ * @param str input hex string of an object id.
+ * @return -1 if str is not valid, <0 if id sorts before str,
+ *         0 if id matches str, >0 if id sorts after str.
+ */
+GIT_EXTERN(int) git_oid_strcmp(const git_oid *id, const char *str);
+
+/**
+ * Check is an oid is all zeros.
+ *
+ * @return 1 if all zeros, 0 otherwise.
+ */
+GIT_EXTERN(int) git_oid_iszero(const git_oid *id);
+
+/**
+ * OID Shortener object
+ */
+typedef struct git_oid_shorten git_oid_shorten;
+
+/**
+ * Create a new OID shortener.
+ *
+ * The OID shortener is used to process a list of OIDs
+ * in text form and return the shortest length that would
+ * uniquely identify all of them.
+ *
+ * E.g. look at the result of `git log --abbrev`.
+ *
+ * @param min_length The minimal length for all identifiers,
+ *		which will be used even if shorter OIDs would still
+ *		be unique.
+ *	@return a `git_oid_shorten` instance, NULL if OOM
+ */
+GIT_EXTERN(git_oid_shorten *) git_oid_shorten_new(size_t min_length);
+
+/**
+ * Add a new OID to set of shortened OIDs and calculate
+ * the minimal length to uniquely identify all the OIDs in
+ * the set.
+ *
+ * The OID is expected to be a 40-char hexadecimal string.
+ * The OID is owned by the user and will not be modified
+ * or freed.
+ *
+ * For performance reasons, there is a hard-limit of how many
+ * OIDs can be added to a single set (around ~32000, assuming
+ * a mostly randomized distribution), which should be enough
+ * for any kind of program, and keeps the algorithm fast and
+ * memory-efficient.
+ *
+ * Attempting to add more than those OIDs will result in a
+ * GITERR_INVALID error
+ *
+ * @param os a `git_oid_shorten` instance
+ * @param text_id an OID in text form
+ * @return the minimal length to uniquely identify all OIDs
+ *		added so far to the set; or an error code (<0) if an
+ *		error occurs.
+ */
+GIT_EXTERN(int) git_oid_shorten_add(git_oid_shorten *os, const char *text_id);
+
+/**
+ * Free an OID shortener instance
+ *
+ * @param os a `git_oid_shorten` instance
+ */
+GIT_EXTERN(void) git_oid_shorten_free(git_oid_shorten *os);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/oidarray.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/oidarray.h b/vendor/libgit2-sys/libgit2/include/git2/oidarray.h
new file mode 100644
index 0000000..0b32045
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/oidarray.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_oidarray_h__
+#define INCLUDE_git_oidarray_h__
+
+#include "common.h"
+#include "oid.h"
+
+GIT_BEGIN_DECL
+
+/** Array of object ids */
+typedef struct git_oidarray {
+	git_oid *ids;
+	size_t count;
+} git_oidarray;
+
+/**
+ * Free the OID array
+ *
+ * This method must (and must only) be called on `git_oidarray`
+ * objects where the array is allocated by the library. Not doing so,
+ * will result in a memory leak.
+ *
+ * This does not free the `git_oidarray` itself, since the library will
+ * never allocate that object directly itself (it is more commonly embedded
+ * inside another struct or created on the stack).
+ *
+ * @param array git_oidarray from which to free oid data
+ */
+GIT_EXTERN(void) git_oidarray_free(git_oidarray *array);
+
+/** @} */
+GIT_END_DECL
+
+#endif
+

vendor/libgit2-sys/libgit2/include/git2/pack.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/pack.h b/vendor/libgit2-sys/libgit2/include/git2/pack.h
new file mode 100644
index 0000000..2dfd825
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/pack.h
@@ -0,0 +1,240 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_pack_h__
+#define INCLUDE_git_pack_h__
+
+#include "common.h"
+#include "oid.h"
+
+/**
+ * @file git2/pack.h
+ * @brief Git pack management routines
+ *
+ * Packing objects
+ * ---------------
+ *
+ * Creation of packfiles requires two steps:
+ *
+ * - First, insert all the objects you want to put into the packfile
+ *   using `git_packbuilder_insert` and `git_packbuilder_insert_tree`.
+ *   It's important to add the objects in recency order ("in the order
+ *   that they are 'reachable' from head").
+ *
+ *   "ANY order will give you a working pack, ... [but it is] the thing
+ *   that gives packs good locality. It keeps the objects close to the
+ *   head (whether they are old or new, but they are _reachable_ from the
+ *   head) at the head of the pack. So packs actually have absolutely
+ *   _wonderful_ IO patterns." - Linus Torvalds
+ *   git.git/Documentation/technical/pack-heuristics.txt
+ *
+ * - Second, use `git_packbuilder_write` or `git_packbuilder_foreach` to
+ *   write the resulting packfile.
+ *
+ *   libgit2 will take care of the delta ordering and generation.
+ *   `git_packbuilder_set_threads` can be used to adjust the number of
+ *   threads used for the process.
+ *
+ * See tests/pack/packbuilder.c for an example.
+ *
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Stages that are reported by the packbuilder progress callback.
+ */
+typedef enum {
+	GIT_PACKBUILDER_ADDING_OBJECTS = 0,
+	GIT_PACKBUILDER_DELTAFICATION = 1,
+} git_packbuilder_stage_t;
+
+/**
+ * Initialize a new packbuilder
+ *
+ * @param out The new packbuilder object
+ * @param repo The repository
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_packbuilder_new(git_packbuilder **out, git_repository *repo);
+
+/**
+ * Set number of threads to spawn
+ *
+ * By default, libgit2 won't spawn any threads at all;
+ * when set to 0, libgit2 will autodetect the number of
+ * CPUs.
+ *
+ * @param pb The packbuilder
+ * @param n Number of threads to spawn
+ * @return number of actual threads to be used
+ */
+GIT_EXTERN(unsigned int) git_packbuilder_set_threads(git_packbuilder *pb, unsigned int n);
+
+/**
+ * Insert a single object
+ *
+ * For an optimal pack it's mandatory to insert objects in recency order,
+ * commits followed by trees and blobs.
+ *
+ * @param pb The packbuilder
+ * @param id The oid of the commit
+ * @param name The name; might be NULL
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_packbuilder_insert(git_packbuilder *pb, const git_oid *id, const char *name);
+
+/**
+ * Insert a root tree object
+ *
+ * This will add the tree as well as all referenced trees and blobs.
+ *
+ * @param pb The packbuilder
+ * @param id The oid of the root tree
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_packbuilder_insert_tree(git_packbuilder *pb, const git_oid *id);
+
+/**
+ * Insert a commit object
+ *
+ * This will add a commit as well as the completed referenced tree.
+ *
+ * @param pb The packbuilder
+ * @param id The oid of the commit
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_packbuilder_insert_commit(git_packbuilder *pb, const git_oid *id);
+
+/**
+ * Insert objects as given by the walk
+ *
+ * Those commits and all objects they reference will be inserted into
+ * the packbuilder.
+ *
+ * @param pb the packbuilder
+ * @param walk the revwalk to use to fill the packbuilder
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_packbuilder_insert_walk(git_packbuilder *pb, git_revwalk *walk);
+
+/**
+ * Recursively insert an object and its referenced objects
+ *
+ * Insert the object as well as any object it references.
+ *
+ * @param pb the packbuilder
+ * @param id the id of the root object to insert
+ * @param name optional name for the object
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_packbuilder_insert_recur(git_packbuilder *pb, const git_oid *id, const char *name);
+
+/**
+ * Write the contents of the packfile to an in-memory buffer
+ *
+ * The contents of the buffer will become a valid packfile, even though there
+ * will be no attached index
+ *
+ * @param buf Buffer where to write the packfile
+ * @param pb The packbuilder
+ */
+GIT_EXTERN(int) git_packbuilder_write_buf(git_buf *buf, git_packbuilder *pb);
+
+/**
+ * Write the new pack and corresponding index file to path.
+ *
+ * @param pb The packbuilder
+ * @param path to the directory where the packfile and index should be stored
+ * @param mode permissions to use creating a packfile or 0 for defaults
+ * @param progress_cb function to call with progress information from the indexer (optional)
+ * @param progress_cb_payload payload for the progress callback (optional)
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_packbuilder_write(
+	git_packbuilder *pb,
+	const char *path,
+	unsigned int mode,
+	git_transfer_progress_cb progress_cb,
+	void *progress_cb_payload);
+
+/**
+* Get the packfile's hash
+*
+* A packfile's name is derived from the sorted hashing of all object
+* names. This is only correct after the packfile has been written.
+*
+* @param pb The packbuilder object
+*/
+GIT_EXTERN(const git_oid *) git_packbuilder_hash(git_packbuilder *pb);
+
+typedef int (*git_packbuilder_foreach_cb)(void *buf, size_t size, void *payload);
+
+/**
+ * Create the new pack and pass each object to the callback
+ *
+ * @param pb the packbuilder
+ * @param cb the callback to call with each packed object's buffer
+ * @param payload the callback's data
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_packbuilder_foreach(git_packbuilder *pb, git_packbuilder_foreach_cb cb, void *payload);
+
+/**
+ * Get the total number of objects the packbuilder will write out
+ *
+ * @param pb the packbuilder
+ * @return the number of objects in the packfile
+ */
+GIT_EXTERN(size_t) git_packbuilder_object_count(git_packbuilder *pb);
+
+/**
+ * Get the number of objects the packbuilder has already written out
+ *
+ * @param pb the packbuilder
+ * @return the number of objects which have already been written
+ */
+GIT_EXTERN(size_t) git_packbuilder_written(git_packbuilder *pb);
+
+/** Packbuilder progress notification function */
+typedef int (*git_packbuilder_progress)(
+	int stage,
+	uint32_t current,
+	uint32_t total,
+	void *payload);
+
+/**
+ * Set the callbacks for a packbuilder
+ *
+ * @param pb The packbuilder object
+ * @param progress_cb Function to call with progress information during
+ * pack building. Be aware that this is called inline with pack building
+ * operations, so performance may be affected.
+ * @param progress_cb_payload Payload for progress callback.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_packbuilder_set_callbacks(
+	git_packbuilder *pb,
+	git_packbuilder_progress progress_cb,
+	void *progress_cb_payload);
+
+/**
+ * Free the packbuilder and all associated data
+ *
+ * @param pb The packbuilder
+ */
+GIT_EXTERN(void) git_packbuilder_free(git_packbuilder *pb);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/patch.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/patch.h b/vendor/libgit2-sys/libgit2/include/git2/patch.h
new file mode 100644
index 0000000..b177798
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/patch.h
@@ -0,0 +1,274 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_patch_h__
+#define INCLUDE_git_patch_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+#include "diff.h"
+
+/**
+ * @file git2/patch.h
+ * @brief Patch handling routines.
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * The diff patch is used to store all the text diffs for a delta.
+ *
+ * You can easily loop over the content of patches and get information about
+ * them.
+ */
+typedef struct git_patch git_patch;
+
+/**
+ * Return a patch for an entry in the diff list.
+ *
+ * The `git_patch` is a newly created object contains the text diffs
+ * for the delta.  You have to call `git_patch_free()` when you are
+ * done with it.  You can use the patch object to loop over all the hunks
+ * and lines in the diff of the one delta.
+ *
+ * For an unchanged file or a binary file, no `git_patch` will be
+ * created, the output will be set to NULL, and the `binary` flag will be
+ * set true in the `git_diff_delta` structure.
+ *
+ * It is okay to pass NULL for either of the output parameters; if you pass
+ * NULL for the `git_patch`, then the text diff will not be calculated.
+ *
+ * @param out Output parameter for the delta patch object
+ * @param diff Diff list object
+ * @param idx Index into diff list
+ * @return 0 on success, other value < 0 on error
+ */
+GIT_EXTERN(int) git_patch_from_diff(
+	git_patch **out, git_diff *diff, size_t idx);
+
+/**
+ * Directly generate a patch from the difference between two blobs.
+ *
+ * This is just like `git_diff_blobs()` except it generates a patch object
+ * for the difference instead of directly making callbacks.  You can use the
+ * standard `git_patch` accessor functions to read the patch data, and
+ * you must call `git_patch_free()` on the patch when done.
+ *
+ * @param out The generated patch; NULL on error
+ * @param old_blob Blob for old side of diff, or NULL for empty blob
+ * @param old_as_path Treat old blob as if it had this filename; can be NULL
+ * @param new_blob Blob for new side of diff, or NULL for empty blob
+ * @param new_as_path Treat new blob as if it had this filename; can be NULL
+ * @param opts Options for diff, or NULL for default options
+ * @return 0 on success or error code < 0
+ */
+GIT_EXTERN(int) git_patch_from_blobs(
+	git_patch **out,
+	const git_blob *old_blob,
+	const char *old_as_path,
+	const git_blob *new_blob,
+	const char *new_as_path,
+	const git_diff_options *opts);
+
+/**
+ * Directly generate a patch from the difference between a blob and a buffer.
+ *
+ * This is just like `git_diff_blob_to_buffer()` except it generates a patch
+ * object for the difference instead of directly making callbacks.  You can
+ * use the standard `git_patch` accessor functions to read the patch
+ * data, and you must call `git_patch_free()` on the patch when done.
+ *
+ * @param out The generated patch; NULL on error
+ * @param old_blob Blob for old side of diff, or NULL for empty blob
+ * @param old_as_path Treat old blob as if it had this filename; can be NULL
+ * @param buffer Raw data for new side of diff, or NULL for empty
+ * @param buffer_len Length of raw data for new side of diff
+ * @param buffer_as_path Treat buffer as if it had this filename; can be NULL
+ * @param opts Options for diff, or NULL for default options
+ * @return 0 on success or error code < 0
+ */
+GIT_EXTERN(int) git_patch_from_blob_and_buffer(
+	git_patch **out,
+	const git_blob *old_blob,
+	const char *old_as_path,
+	const void *buffer,
+	size_t buffer_len,
+	const char *buffer_as_path,
+	const git_diff_options *opts);
+
+/**
+ * Directly generate a patch from the difference between two buffers.
+ *
+ * This is just like `git_diff_buffers()` except it generates a patch
+ * object for the difference instead of directly making callbacks.  You can
+ * use the standard `git_patch` accessor functions to read the patch
+ * data, and you must call `git_patch_free()` on the patch when done.
+ *
+ * @param out The generated patch; NULL on error
+ * @param old_buffer Raw data for old side of diff, or NULL for empty
+ * @param old_len Length of the raw data for old side of the diff
+ * @param old_as_path Treat old buffer as if it had this filename; can be NULL
+ * @param new_buffer Raw data for new side of diff, or NULL for empty
+ * @param new_len Length of raw data for new side of diff
+ * @param new_as_path Treat buffer as if it had this filename; can be NULL
+ * @param opts Options for diff, or NULL for default options
+ * @return 0 on success or error code < 0
+ */
+GIT_EXTERN(int) git_patch_from_buffers(
+	git_patch **out,
+	const void *old_buffer,
+	size_t old_len,
+	const char *old_as_path,
+	const void *new_buffer,
+	size_t new_len,
+	const char *new_as_path,
+	const git_diff_options *opts);
+
+/**
+ * Free a git_patch object.
+ */
+GIT_EXTERN(void) git_patch_free(git_patch *patch);
+
+/**
+ * Get the delta associated with a patch.  This delta points to internal
+ * data and you do not have to release it when you are done with it.
+ */
+GIT_EXTERN(const git_diff_delta *) git_patch_get_delta(const git_patch *patch);
+
+/**
+ * Get the number of hunks in a patch
+ */
+GIT_EXTERN(size_t) git_patch_num_hunks(const git_patch *patch);
+
+/**
+ * Get line counts of each type in a patch.
+ *
+ * This helps imitate a diff --numstat type of output.  For that purpose,
+ * you only need the `total_additions` and `total_deletions` values, but we
+ * include the `total_context` line count in case you want the total number
+ * of lines of diff output that will be generated.
+ *
+ * All outputs are optional. Pass NULL if you don't need a particular count.
+ *
+ * @param total_context Count of context lines in output, can be NULL.
+ * @param total_additions Count of addition lines in output, can be NULL.
+ * @param total_deletions Count of deletion lines in output, can be NULL.
+ * @param patch The git_patch object
+ * @return 0 on success, <0 on error
+ */
+GIT_EXTERN(int) git_patch_line_stats(
+	size_t *total_context,
+	size_t *total_additions,
+	size_t *total_deletions,
+	const git_patch *patch);
+
+/**
+ * Get the information about a hunk in a patch
+ *
+ * Given a patch and a hunk index into the patch, this returns detailed
+ * information about that hunk.  Any of the output pointers can be passed
+ * as NULL if you don't care about that particular piece of information.
+ *
+ * @param out Output pointer to git_diff_hunk of hunk
+ * @param lines_in_hunk Output count of total lines in this hunk
+ * @param patch Input pointer to patch object
+ * @param hunk_idx Input index of hunk to get information about
+ * @return 0 on success, GIT_ENOTFOUND if hunk_idx out of range, <0 on error
+ */
+GIT_EXTERN(int) git_patch_get_hunk(
+	const git_diff_hunk **out,
+	size_t *lines_in_hunk,
+	git_patch *patch,
+	size_t hunk_idx);
+
+/**
+ * Get the number of lines in a hunk.
+ *
+ * @param patch The git_patch object
+ * @param hunk_idx Index of the hunk
+ * @return Number of lines in hunk or GIT_ENOTFOUND if invalid hunk index
+ */
+GIT_EXTERN(int) git_patch_num_lines_in_hunk(
+	const git_patch *patch,
+	size_t hunk_idx);
+
+/**
+ * Get data about a line in a hunk of a patch.
+ *
+ * Given a patch, a hunk index, and a line index in the hunk, this
+ * will return a lot of details about that line.  If you pass a hunk
+ * index larger than the number of hunks or a line index larger than
+ * the number of lines in the hunk, this will return -1.
+ *
+ * @param out The git_diff_line data for this line
+ * @param patch The patch to look in
+ * @param hunk_idx The index of the hunk
+ * @param line_of_hunk The index of the line in the hunk
+ * @return 0 on success, <0 on failure
+ */
+GIT_EXTERN(int) git_patch_get_line_in_hunk(
+	const git_diff_line **out,
+	git_patch *patch,
+	size_t hunk_idx,
+	size_t line_of_hunk);
+
+/**
+ * Look up size of patch diff data in bytes
+ *
+ * This returns the raw size of the patch data.  This only includes the
+ * actual data from the lines of the diff, not the file or hunk headers.
+ *
+ * If you pass `include_context` as true (non-zero), this will be the size
+ * of all of the diff output; if you pass it as false (zero), this will
+ * only include the actual changed lines (as if `context_lines` was 0).
+ *
+ * @param patch A git_patch representing changes to one file
+ * @param include_context Include context lines in size if non-zero
+ * @param include_hunk_headers Include hunk header lines if non-zero
+ * @param include_file_headers Include file header lines if non-zero
+ * @return The number of bytes of data
+ */
+GIT_EXTERN(size_t) git_patch_size(
+	git_patch *patch,
+	int include_context,
+	int include_hunk_headers,
+	int include_file_headers);
+
+/**
+ * Serialize the patch to text via callback.
+ *
+ * Returning a non-zero value from the callback will terminate the iteration
+ * and return that value to the caller.
+ *
+ * @param patch A git_patch representing changes to one file
+ * @param print_cb Callback function to output lines of the patch.  Will be
+ *                 called for file headers, hunk headers, and diff lines.
+ * @param payload Reference pointer that will be passed to your callbacks.
+ * @return 0 on success, non-zero callback return value, or error code
+ */
+GIT_EXTERN(int) git_patch_print(
+	git_patch *patch,
+	git_diff_line_cb print_cb,
+	void *payload);
+
+/**
+ * Get the content of a patch as a single diff text.
+ *
+ * @param out The git_buf to be filled in
+ * @param patch A git_patch representing changes to one file
+ * @return 0 on success, <0 on failure.
+ */
+GIT_EXTERN(int) git_patch_to_buf(
+	git_buf *out,
+	git_patch *patch);
+
+GIT_END_DECL
+
+/**@}*/
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/pathspec.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/pathspec.h b/vendor/libgit2-sys/libgit2/include/git2/pathspec.h
new file mode 100644
index 0000000..3299657
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/pathspec.h
@@ -0,0 +1,280 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_pathspec_h__
+#define INCLUDE_git_pathspec_h__
+
+#include "common.h"
+#include "types.h"
+#include "strarray.h"
+#include "diff.h"
+
+GIT_BEGIN_DECL
+
+/**
+ * Compiled pathspec
+ */
+typedef struct git_pathspec git_pathspec;
+
+/**
+ * List of filenames matching a pathspec
+ */
+typedef struct git_pathspec_match_list git_pathspec_match_list;
+
+/**
+ * Options controlling how pathspec match should be executed
+ */
+typedef enum {
+	GIT_PATHSPEC_DEFAULT        = 0,
+
+	/**
+	 * GIT_PATHSPEC_IGNORE_CASE forces match to ignore case; otherwise
+	 * match will use native case sensitivity of platform filesystem
+	 */
+	GIT_PATHSPEC_IGNORE_CASE    = (1u << 0),
+
+	/**
+	 * GIT_PATHSPEC_USE_CASE forces case sensitive match; otherwise
+	 * match will use native case sensitivity of platform filesystem
+	 */
+	GIT_PATHSPEC_USE_CASE       = (1u << 1),
+
+	/**
+	 * GIT_PATHSPEC_NO_GLOB disables glob patterns and just uses simple
+	 * string comparison for matching
+	 */
+	GIT_PATHSPEC_NO_GLOB        = (1u << 2),
+
+	/**
+	 * GIT_PATHSPEC_NO_MATCH_ERROR means the match functions return error
+	 * code GIT_ENOTFOUND if no matches are found; otherwise no matches is
+	 * still success (return 0) but `git_pathspec_match_list_entrycount`
+	 * will indicate 0 matches.
+	 */
+	GIT_PATHSPEC_NO_MATCH_ERROR = (1u << 3),
+
+	/**
+	 * GIT_PATHSPEC_FIND_FAILURES means that the `git_pathspec_match_list`
+	 * should track which patterns matched which files so that at the end of
+	 * the match we can identify patterns that did not match any files.
+	 */
+	GIT_PATHSPEC_FIND_FAILURES  = (1u << 4),
+
+	/**
+	 * GIT_PATHSPEC_FAILURES_ONLY means that the `git_pathspec_match_list`
+	 * does not need to keep the actual matching filenames.  Use this to
+	 * just test if there were any matches at all or in combination with
+	 * GIT_PATHSPEC_FIND_FAILURES to validate a pathspec.
+	 */
+	GIT_PATHSPEC_FAILURES_ONLY  = (1u << 5),
+} git_pathspec_flag_t;
+
+/**
+ * Compile a pathspec
+ *
+ * @param out Output of the compiled pathspec
+ * @param pathspec A git_strarray of the paths to match
+ * @return 0 on success, <0 on failure
+ */
+GIT_EXTERN(int) git_pathspec_new(
+	git_pathspec **out, const git_strarray *pathspec);
+
+/**
+ * Free a pathspec
+ *
+ * @param ps The compiled pathspec
+ */
+GIT_EXTERN(void) git_pathspec_free(git_pathspec *ps);
+
+/**
+ * Try to match a path against a pathspec
+ *
+ * Unlike most of the other pathspec matching functions, this will not
+ * fall back on the native case-sensitivity for your platform.  You must
+ * explicitly pass flags to control case sensitivity or else this will
+ * fall back on being case sensitive.
+ *
+ * @param ps The compiled pathspec
+ * @param flags Combination of git_pathspec_flag_t options to control match
+ * @param path The pathname to attempt to match
+ * @return 1 is path matches spec, 0 if it does not
+ */
+GIT_EXTERN(int) git_pathspec_matches_path(
+	const git_pathspec *ps, uint32_t flags, const char *path);
+
+/**
+ * Match a pathspec against the working directory of a repository.
+ *
+ * This matches the pathspec against the current files in the working
+ * directory of the repository.  It is an error to invoke this on a bare
+ * repo.  This handles git ignores (i.e. ignored files will not be
+ * considered to match the `pathspec` unless the file is tracked in the
+ * index).
+ *
+ * If `out` is not NULL, this returns a `git_patchspec_match_list`.  That
+ * contains the list of all matched filenames (unless you pass the
+ * `GIT_PATHSPEC_FAILURES_ONLY` flag) and may also contain the list of
+ * pathspecs with no match (if you used the `GIT_PATHSPEC_FIND_FAILURES`
+ * flag).  You must call `git_pathspec_match_list_free()` on this object.
+ *
+ * @param out Output list of matches; pass NULL to just get return value
+ * @param repo The repository in which to match; bare repo is an error
+ * @param flags Combination of git_pathspec_flag_t options to control match
+ * @param ps Pathspec to be matched
+ * @return 0 on success, -1 on error, GIT_ENOTFOUND if no matches and
+ *         the GIT_PATHSPEC_NO_MATCH_ERROR flag was given
+ */
+GIT_EXTERN(int) git_pathspec_match_workdir(
+	git_pathspec_match_list **out,
+	git_repository *repo,
+	uint32_t flags,
+	git_pathspec *ps);
+
+/**
+ * Match a pathspec against entries in an index.
+ *
+ * This matches the pathspec against the files in the repository index.
+ *
+ * NOTE: At the moment, the case sensitivity of this match is controlled
+ * by the current case-sensitivity of the index object itself and the
+ * USE_CASE and IGNORE_CASE flags will have no effect.  This behavior will
+ * be corrected in a future release.
+ *
+ * If `out` is not NULL, this returns a `git_patchspec_match_list`.  That
+ * contains the list of all matched filenames (unless you pass the
+ * `GIT_PATHSPEC_FAILURES_ONLY` flag) and may also contain the list of
+ * pathspecs with no match (if you used the `GIT_PATHSPEC_FIND_FAILURES`
+ * flag).  You must call `git_pathspec_match_list_free()` on this object.
+ *
+ * @param out Output list of matches; pass NULL to just get return value
+ * @param index The index to match against
+ * @param flags Combination of git_pathspec_flag_t options to control match
+ * @param ps Pathspec to be matched
+ * @return 0 on success, -1 on error, GIT_ENOTFOUND if no matches and
+ *         the GIT_PATHSPEC_NO_MATCH_ERROR flag is used
+ */
+GIT_EXTERN(int) git_pathspec_match_index(
+	git_pathspec_match_list **out,
+	git_index *index,
+	uint32_t flags,
+	git_pathspec *ps);
+
+/**
+ * Match a pathspec against files in a tree.
+ *
+ * This matches the pathspec against the files in the given tree.
+ *
+ * If `out` is not NULL, this returns a `git_patchspec_match_list`.  That
+ * contains the list of all matched filenames (unless you pass the
+ * `GIT_PATHSPEC_FAILURES_ONLY` flag) and may also contain the list of
+ * pathspecs with no match (if you used the `GIT_PATHSPEC_FIND_FAILURES`
+ * flag).  You must call `git_pathspec_match_list_free()` on this object.
+ *
+ * @param out Output list of matches; pass NULL to just get return value
+ * @param tree The root-level tree to match against
+ * @param flags Combination of git_pathspec_flag_t options to control match
+ * @param ps Pathspec to be matched
+ * @return 0 on success, -1 on error, GIT_ENOTFOUND if no matches and
+ *         the GIT_PATHSPEC_NO_MATCH_ERROR flag is used
+ */
+GIT_EXTERN(int) git_pathspec_match_tree(
+	git_pathspec_match_list **out,
+	git_tree *tree,
+	uint32_t flags,
+	git_pathspec *ps);
+
+/**
+ * Match a pathspec against files in a diff list.
+ *
+ * This matches the pathspec against the files in the given diff list.
+ *
+ * If `out` is not NULL, this returns a `git_patchspec_match_list`.  That
+ * contains the list of all matched filenames (unless you pass the
+ * `GIT_PATHSPEC_FAILURES_ONLY` flag) and may also contain the list of
+ * pathspecs with no match (if you used the `GIT_PATHSPEC_FIND_FAILURES`
+ * flag).  You must call `git_pathspec_match_list_free()` on this object.
+ *
+ * @param out Output list of matches; pass NULL to just get return value
+ * @param diff A generated diff list
+ * @param flags Combination of git_pathspec_flag_t options to control match
+ * @param ps Pathspec to be matched
+ * @return 0 on success, -1 on error, GIT_ENOTFOUND if no matches and
+ *         the GIT_PATHSPEC_NO_MATCH_ERROR flag is used
+ */
+GIT_EXTERN(int) git_pathspec_match_diff(
+	git_pathspec_match_list **out,
+	git_diff *diff,
+	uint32_t flags,
+	git_pathspec *ps);
+
+/**
+ * Free memory associates with a git_pathspec_match_list
+ *
+ * @param m The git_pathspec_match_list to be freed
+ */
+GIT_EXTERN(void) git_pathspec_match_list_free(git_pathspec_match_list *m);
+
+/**
+ * Get the number of items in a match list.
+ *
+ * @param m The git_pathspec_match_list object
+ * @return Number of items in match list
+ */
+GIT_EXTERN(size_t) git_pathspec_match_list_entrycount(
+	const git_pathspec_match_list *m);
+
+/**
+ * Get a matching filename by position.
+ *
+ * This routine cannot be used if the match list was generated by
+ * `git_pathspec_match_diff`.  If so, it will always return NULL.
+ *
+ * @param m The git_pathspec_match_list object
+ * @param pos The index into the list
+ * @return The filename of the match
+ */
+GIT_EXTERN(const char *) git_pathspec_match_list_entry(
+	const git_pathspec_match_list *m, size_t pos);
+
+/**
+ * Get a matching diff delta by position.
+ *
+ * This routine can only be used if the match list was generated by
+ * `git_pathspec_match_diff`.  Otherwise it will always return NULL.
+ *
+ * @param m The git_pathspec_match_list object
+ * @param pos The index into the list
+ * @return The filename of the match
+ */
+GIT_EXTERN(const git_diff_delta *) git_pathspec_match_list_diff_entry(
+	const git_pathspec_match_list *m, size_t pos);
+
+/**
+ * Get the number of pathspec items that did not match.
+ *
+ * This will be zero unless you passed GIT_PATHSPEC_FIND_FAILURES when
+ * generating the git_pathspec_match_list.
+ *
+ * @param m The git_pathspec_match_list object
+ * @return Number of items in original pathspec that had no matches
+ */
+GIT_EXTERN(size_t) git_pathspec_match_list_failed_entrycount(
+	const git_pathspec_match_list *m);
+
+/**
+ * Get an original pathspec string that had no matches.
+ *
+ * This will be return NULL for positions out of range.
+ *
+ * @param m The git_pathspec_match_list object
+ * @param pos The index into the failed items
+ * @return The pathspec pattern that didn't match anything
+ */
+GIT_EXTERN(const char *) git_pathspec_match_list_failed_entry(
+	const git_pathspec_match_list *m, size_t pos);
+
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/proxy.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/proxy.h b/vendor/libgit2-sys/libgit2/include/git2/proxy.h
new file mode 100644
index 0000000..06d46d3
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/proxy.h
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_proxy_h__
+#define INCLUDE_git_proxy_h__
+
+#include "common.h"
+#include "transport.h"
+
+GIT_BEGIN_DECL
+
+/**
+ * The type of proxy to use.
+ */
+typedef enum {
+	/**
+	 * Do not attempt to connect through a proxy
+	 *
+	 * If built against libcurl, it itself may attempt to connect
+	 * to a proxy if the environment variables specify it.
+	 */
+	GIT_PROXY_NONE,
+	/**
+	 * Try to auto-detect the proxy from the git configuration.
+	 */
+	GIT_PROXY_AUTO,
+	/**
+	 * Connect via the URL given in the options
+	 */
+	GIT_PROXY_SPECIFIED,
+} git_proxy_t;
+
+/**
+ * Options for connecting through a proxy
+ *
+ * Note that not all types may be supported, depending on the platform
+ * and compilation options.
+ */
+typedef struct {
+	unsigned int version;
+
+	/**
+	 * The type of proxy to use, by URL, auto-detect.
+	 */
+	git_proxy_t type;
+
+	/**
+	 * The URL of the proxy.
+	 */
+	const char *url;
+
+	/**
+	 * This will be called if the remote host requires
+	 * authentication in order to connect to it.
+	 *
+	 * Returning GIT_PASSTHROUGH will make libgit2 behave as
+	 * though this field isn't set.
+	 */
+	git_cred_acquire_cb credentials;
+
+	/**
+	 * If cert verification fails, this will be called to let the
+	 * user make the final decision of whether to allow the
+	 * connection to proceed. Returns 0 to allow the connection
+	 * or a negative value to indicate an error.
+	 */
+        git_transport_certificate_check_cb certificate_check;
+
+	/**
+	 * Payload to be provided to the credentials and certificate
+	 * check callbacks.
+	 */
+	void *payload;
+} git_proxy_options;
+
+#define GIT_PROXY_OPTIONS_VERSION 1
+#define GIT_PROXY_OPTIONS_INIT {GIT_PROXY_OPTIONS_VERSION}
+
+/**
+ * Initialize a proxy options structure
+ *
+ * @param opts the options struct to initialize
+ * @param version the version of the struct, use `GIT_PROXY_OPTIONS_VERSION`
+ */
+GIT_EXTERN(int) git_proxy_init_options(git_proxy_options *opts, unsigned int version);
+
+GIT_END_DECL
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/rebase.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/rebase.h b/vendor/libgit2-sys/libgit2/include/git2/rebase.h
new file mode 100644
index 0000000..9b9065e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/rebase.h
@@ -0,0 +1,320 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_rebase_h__
+#define INCLUDE_git_rebase_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+#include "annotated_commit.h"
+
+/**
+ * @file git2/rebase.h
+ * @brief Git rebase routines
+ * @defgroup git_rebase Git merge routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Rebase options
+ *
+ * Use to tell the rebase machinery how to operate.
+ */
+typedef struct {
+	unsigned int version;
+
+	/**
+	 * Used by `git_rebase_init`, this will instruct other clients working
+	 * on this rebase that you want a quiet rebase experience, which they
+	 * may choose to provide in an application-specific manner.  This has no
+	 * effect upon libgit2 directly, but is provided for interoperability
+	 * between Git tools.
+	 */
+	int quiet;
+
+	/**
+	 * Used by `git_rebase_init`, this will begin an in-memory rebase,
+	 * which will allow callers to step through the rebase operations and
+	 * commit the rebased changes, but will not rewind HEAD or update the
+	 * repository to be in a rebasing state.  This will not interfere with
+	 * the working directory (if there is one).
+	 */
+	int inmemory;
+
+	/**
+	 * Used by `git_rebase_finish`, this is the name of the notes reference
+	 * used to rewrite notes for rebased commits when finishing the rebase;
+	 * if NULL, the contents of the configuration option `notes.rewriteRef`
+	 * is examined, unless the configuration option `notes.rewrite.rebase`
+	 * is set to false.  If `notes.rewriteRef` is also NULL, notes will
+	 * not be rewritten.
+	 */
+	const char *rewrite_notes_ref;
+
+	/**
+	 * Options to control how trees are merged during `git_rebase_next`.
+	 */
+	git_merge_options merge_options;
+
+	/**
+	 * Options to control how files are written during `git_rebase_init`,
+	 * `git_rebase_next` and `git_rebase_abort`.  Note that a minimum
+	 * strategy of `GIT_CHECKOUT_SAFE` is defaulted in `init` and `next`,
+	 * and a minimum strategy of `GIT_CHECKOUT_FORCE` is defaulted in
+	 * `abort` to match git semantics.
+	 */
+	git_checkout_options checkout_options;
+} git_rebase_options;
+
+/**
+ * Type of rebase operation in-progress after calling `git_rebase_next`.
+ */
+typedef enum {
+	/**
+	 * The given commit is to be cherry-picked.  The client should commit
+	 * the changes and continue if there are no conflicts.
+	 */
+	GIT_REBASE_OPERATION_PICK = 0,
+
+	/**
+	 * The given commit is to be cherry-picked, but the client should prompt
+	 * the user to provide an updated commit message.
+	 */
+	GIT_REBASE_OPERATION_REWORD,
+
+	/**
+	 * The given commit is to be cherry-picked, but the client should stop
+	 * to allow the user to edit the changes before committing them.
+	 */
+	GIT_REBASE_OPERATION_EDIT,
+
+	/**
+	 * The given commit is to be squashed into the previous commit.  The
+	 * commit message will be merged with the previous message.
+	 */
+	GIT_REBASE_OPERATION_SQUASH,
+
+	/**
+	 * The given commit is to be squashed into the previous commit.  The
+	 * commit message from this commit will be discarded.
+	 */
+	GIT_REBASE_OPERATION_FIXUP,
+
+	/**
+	 * No commit will be cherry-picked.  The client should run the given
+	 * command and (if successful) continue.
+	 */
+	GIT_REBASE_OPERATION_EXEC,
+} git_rebase_operation_t;
+
+#define GIT_REBASE_OPTIONS_VERSION 1
+#define GIT_REBASE_OPTIONS_INIT \
+	{ GIT_REBASE_OPTIONS_VERSION, 0, 0, NULL, GIT_MERGE_OPTIONS_INIT, \
+	  GIT_CHECKOUT_OPTIONS_INIT}
+
+/** Indicates that a rebase operation is not (yet) in progress. */
+#define GIT_REBASE_NO_OPERATION SIZE_MAX
+
+/**
+ * A rebase operation
+ *
+ * Describes a single instruction/operation to be performed during the
+ * rebase.
+ */
+typedef struct {
+	/** The type of rebase operation. */
+	git_rebase_operation_t type;
+
+	/**
+	 * The commit ID being cherry-picked.  This will be populated for
+	 * all operations except those of type `GIT_REBASE_OPERATION_EXEC`.
+	 */
+	const git_oid id;
+
+	/**
+	 * The executable the user has requested be run.  This will only
+	 * be populated for operations of type `GIT_REBASE_OPERATION_EXEC`.
+	 */
+	const char *exec;
+} git_rebase_operation;
+
+/**
+ * Initializes a `git_rebase_options` with default values. Equivalent to
+ * creating an instance with GIT_REBASE_OPTIONS_INIT.
+ *
+ * @param opts the `git_rebase_options` instance to initialize.
+ * @param version the version of the struct; you should pass
+ *        `GIT_REBASE_OPTIONS_VERSION` here.
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_rebase_init_options(
+	git_rebase_options *opts,
+	unsigned int version);
+
+/**
+ * Initializes a rebase operation to rebase the changes in `branch`
+ * relative to `upstream` onto another branch.  To begin the rebase
+ * process, call `git_rebase_next`.  When you have finished with this
+ * object, call `git_rebase_free`.
+ *
+ * @param out Pointer to store the rebase object
+ * @param repo The repository to perform the rebase
+ * @param branch The terminal commit to rebase, or NULL to rebase the
+ *               current branch
+ * @param upstream The commit to begin rebasing from, or NULL to rebase all
+ *                 reachable commits
+ * @param onto The branch to rebase onto, or NULL to rebase onto the given
+ *             upstream
+ * @param opts Options to specify how rebase is performed, or NULL
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_rebase_init(
+	git_rebase **out,
+	git_repository *repo,
+	const git_annotated_commit *branch,
+	const git_annotated_commit *upstream,
+	const git_annotated_commit *onto,
+	const git_rebase_options *opts);
+
+/**
+ * Opens an existing rebase that was previously started by either an
+ * invocation of `git_rebase_init` or by another client.
+ *
+ * @param out Pointer to store the rebase object
+ * @param repo The repository that has a rebase in-progress
+ * @param opts Options to specify how rebase is performed
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_rebase_open(
+	git_rebase **out,
+	git_repository *repo,
+	const git_rebase_options *opts);
+
+/**
+ * Gets the count of rebase operations that are to be applied.
+ *
+ * @param rebase The in-progress rebase
+ * @return The number of rebase operations in total
+ */
+GIT_EXTERN(size_t) git_rebase_operation_entrycount(git_rebase *rebase);
+
+/**
+ * Gets the index of the rebase operation that is currently being applied.
+ * If the first operation has not yet been applied (because you have
+ * called `init` but not yet `next`) then this returns
+ * `GIT_REBASE_NO_OPERATION`.
+ *
+ * @param rebase The in-progress rebase
+ * @return The index of the rebase operation currently being applied.
+ */
+GIT_EXTERN(size_t) git_rebase_operation_current(git_rebase *rebase);
+
+/**
+ * Gets the rebase operation specified by the given index.
+ *
+ * @param rebase The in-progress rebase
+ * @param idx The index of the rebase operation to retrieve
+ * @return The rebase operation or NULL if `idx` was out of bounds
+ */
+GIT_EXTERN(git_rebase_operation *) git_rebase_operation_byindex(
+	git_rebase *rebase,
+	size_t idx);
+
+/**
+ * Performs the next rebase operation and returns the information about it.
+ * If the operation is one that applies a patch (which is any operation except
+ * GIT_REBASE_OPERATION_EXEC) then the patch will be applied and the index and
+ * working directory will be updated with the changes.  If there are conflicts,
+ * you will need to address those before committing the changes.
+ *
+ * @param operation Pointer to store the rebase operation that is to be performed next
+ * @param rebase The rebase in progress
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_rebase_next(
+	git_rebase_operation **operation,
+	git_rebase *rebase);
+
+/**
+ * Gets the index produced by the last operation, which is the result
+ * of `git_rebase_next` and which will be committed by the next
+ * invocation of `git_rebase_commit`.  This is useful for resolving
+ * conflicts in an in-memory rebase before committing them.  You must
+ * call `git_index_free` when you are finished with this.
+ *
+ * This is only applicable for in-memory rebases; for rebases within
+ * a working directory, the changes were applied to the repository's
+ * index.
+ */
+GIT_EXTERN(int) git_rebase_inmemory_index(
+	git_index **index,
+	git_rebase *rebase);
+
+/**
+ * Commits the current patch.  You must have resolved any conflicts that
+ * were introduced during the patch application from the `git_rebase_next`
+ * invocation.
+ *
+ * @param id Pointer in which to store the OID of the newly created commit
+ * @param rebase The rebase that is in-progress
+ * @param author The author of the updated commit, or NULL to keep the
+ *        author from the original commit
+ * @param committer The committer of the rebase
+ * @param message_encoding The encoding for the message in the commit,
+ *        represented with a standard encoding name.  If message is NULL,
+ *        this should also be NULL, and the encoding from the original
+ *        commit will be maintained.  If message is specified, this may be
+ *        NULL to indicate that "UTF-8" is to be used.
+ * @param message The message for this commit, or NULL to use the message
+ *        from the original commit.
+ * @return Zero on success, GIT_EUNMERGED if there are unmerged changes in
+ *        the index, GIT_EAPPLIED if the current commit has already
+ *        been applied to the upstream and there is nothing to commit,
+ *        -1 on failure.
+ */
+GIT_EXTERN(int) git_rebase_commit(
+	git_oid *id,
+	git_rebase *rebase,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message);
+
+/**
+ * Aborts a rebase that is currently in progress, resetting the repository
+ * and working directory to their state before rebase began.
+ *
+ * @param rebase The rebase that is in-progress
+ * @return Zero on success; GIT_ENOTFOUND if a rebase is not in progress,
+ *         -1 on other errors.
+ */
+GIT_EXTERN(int) git_rebase_abort(git_rebase *rebase);
+
+/**
+ * Finishes a rebase that is currently in progress once all patches have
+ * been applied.
+ *
+ * @param rebase The rebase that is in-progress
+ * @param signature The identity that is finishing the rebase (optional)
+ * @return Zero on success; -1 on error
+ */
+GIT_EXTERN(int) git_rebase_finish(
+	git_rebase *rebase,
+	const git_signature *signature);
+
+/**
+ * Frees the `git_rebase` object.
+ *
+ * @param rebase The rebase object
+ */
+GIT_EXTERN(void) git_rebase_free(git_rebase *rebase);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/refdb.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/refdb.h b/vendor/libgit2-sys/libgit2/include/git2/refdb.h
new file mode 100644
index 0000000..a315876
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/refdb.h
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_refdb_h__
+#define INCLUDE_git_refdb_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+#include "refs.h"
+
+/**
+ * @file git2/refdb.h
+ * @brief Git custom refs backend functions
+ * @defgroup git_refdb Git custom refs backend API
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Create a new reference database with no backends.
+ *
+ * Before the Ref DB can be used for read/writing, a custom database
+ * backend must be manually set using `git_refdb_set_backend()`
+ *
+ * @param out location to store the database pointer, if opened.
+ *			Set to NULL if the open failed.
+ * @param repo the repository
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_refdb_new(git_refdb **out, git_repository *repo);
+
+/**
+ * Create a new reference database and automatically add
+ * the default backends:
+ *
+ *  - git_refdb_dir: read and write loose and packed refs
+ *      from disk, assuming the repository dir as the folder
+ *
+ * @param out location to store the database pointer, if opened.
+ *			Set to NULL if the open failed.
+ * @param repo the repository
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_refdb_open(git_refdb **out, git_repository *repo);
+
+/**
+ * Suggests that the given refdb compress or optimize its references.
+ * This mechanism is implementation specific.  For on-disk reference
+ * databases, for example, this may pack all loose references.
+ */
+GIT_EXTERN(int) git_refdb_compress(git_refdb *refdb);
+
+/**
+ * Close an open reference database.
+ *
+ * @param refdb reference database pointer or NULL
+ */
+GIT_EXTERN(void) git_refdb_free(git_refdb *refdb);
+
+/** @} */
+GIT_END_DECL
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/reflog.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/reflog.h b/vendor/libgit2-sys/libgit2/include/git2/reflog.h
new file mode 100644
index 0000000..c949a28
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/reflog.h
@@ -0,0 +1,170 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_reflog_h__
+#define INCLUDE_git_reflog_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+
+/**
+ * @file git2/reflog.h
+ * @brief Git reflog management routines
+ * @defgroup git_reflog Git reflog management routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Read the reflog for the given reference
+ *
+ * If there is no reflog file for the given
+ * reference yet, an empty reflog object will
+ * be returned.
+ *
+ * The reflog must be freed manually by using
+ * git_reflog_free().
+ *
+ * @param out pointer to reflog
+ * @param repo the repostiory
+ * @param name reference to look up
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_reflog_read(git_reflog **out, git_repository *repo,  const char *name);
+
+/**
+ * Write an existing in-memory reflog object back to disk
+ * using an atomic file lock.
+ *
+ * @param reflog an existing reflog object
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_reflog_write(git_reflog *reflog);
+
+/**
+ * Add a new entry to the in-memory reflog.
+ *
+ * `msg` is optional and can be NULL.
+ *
+ * @param reflog an existing reflog object
+ * @param id the OID the reference is now pointing to
+ * @param committer the signature of the committer
+ * @param msg the reflog message
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_reflog_append(git_reflog *reflog, const git_oid *id, const git_signature *committer, const char *msg);
+
+/**
+ * Rename a reflog
+ *
+ * The reflog to be renamed is expected to already exist
+ *
+ * The new name will be checked for validity.
+ * See `git_reference_create_symbolic()` for rules about valid names.
+ *
+ * @param repo the repository
+ * @param old_name the old name of the reference
+ * @param name the new name of the reference
+ * @return 0 on success, GIT_EINVALIDSPEC or an error code
+ */
+GIT_EXTERN(int) git_reflog_rename(git_repository *repo, const char *old_name, const char *name);
+
+/**
+ * Delete the reflog for the given reference
+ *
+ * @param repo the repository
+ * @param name the reflog to delete
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_reflog_delete(git_repository *repo, const char *name);
+
+/**
+ * Get the number of log entries in a reflog
+ *
+ * @param reflog the previously loaded reflog
+ * @return the number of log entries
+ */
+GIT_EXTERN(size_t) git_reflog_entrycount(git_reflog *reflog);
+
+/**
+ * Lookup an entry by its index
+ *
+ * Requesting the reflog entry with an index of 0 (zero) will
+ * return the most recently created entry.
+ *
+ * @param reflog a previously loaded reflog
+ * @param idx the position of the entry to lookup. Should be greater than or
+ * equal to 0 (zero) and less than `git_reflog_entrycount()`.
+ * @return the entry; NULL if not found
+ */
+GIT_EXTERN(const git_reflog_entry *) git_reflog_entry_byindex(const git_reflog *reflog, size_t idx);
+
+/**
+ * Remove an entry from the reflog by its index
+ *
+ * To ensure there's no gap in the log history, set `rewrite_previous_entry`
+ * param value to 1. When deleting entry `n`, member old_oid of entry `n-1`
+ * (if any) will be updated with the value of member new_oid of entry `n+1`.
+ *
+ * @param reflog a previously loaded reflog.
+ *
+ * @param idx the position of the entry to remove. Should be greater than or
+ * equal to 0 (zero) and less than `git_reflog_entrycount()`.
+ *
+ * @param rewrite_previous_entry 1 to rewrite the history; 0 otherwise.
+ *
+ * @return 0 on success, GIT_ENOTFOUND if the entry doesn't exist
+ * or an error code.
+ */
+GIT_EXTERN(int) git_reflog_drop(
+	git_reflog *reflog,
+	size_t idx,
+	int rewrite_previous_entry);
+
+/**
+ * Get the old oid
+ *
+ * @param entry a reflog entry
+ * @return the old oid
+ */
+GIT_EXTERN(const git_oid *) git_reflog_entry_id_old(const git_reflog_entry *entry);
+
+/**
+ * Get the new oid
+ *
+ * @param entry a reflog entry
+ * @return the new oid at this time
+ */
+GIT_EXTERN(const git_oid *) git_reflog_entry_id_new(const git_reflog_entry *entry);
+
+/**
+ * Get the committer of this entry
+ *
+ * @param entry a reflog entry
+ * @return the committer
+ */
+GIT_EXTERN(const git_signature *) git_reflog_entry_committer(const git_reflog_entry *entry);
+
+/**
+ * Get the log message
+ *
+ * @param entry a reflog entry
+ * @return the log msg
+ */
+GIT_EXTERN(const char *) git_reflog_entry_message(const git_reflog_entry *entry);
+
+/**
+ * Free the reflog
+ *
+ * @param reflog reflog to free
+ */
+GIT_EXTERN(void) git_reflog_free(git_reflog *reflog);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/refs.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/refs.h b/vendor/libgit2-sys/libgit2/include/git2/refs.h
new file mode 100644
index 0000000..0dd453e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/refs.h
@@ -0,0 +1,749 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_refs_h__
+#define INCLUDE_git_refs_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+#include "strarray.h"
+
+/**
+ * @file git2/refs.h
+ * @brief Git reference management routines
+ * @defgroup git_reference Git reference management routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Lookup a reference by name in a repository.
+ *
+ * The returned reference must be freed by the user.
+ *
+ * The name will be checked for validity.
+ * See `git_reference_symbolic_create()` for rules about valid names.
+ *
+ * @param out pointer to the looked-up reference
+ * @param repo the repository to look up the reference
+ * @param name the long name for the reference (e.g. HEAD, refs/heads/master, refs/tags/v0.1.0, ...)
+ * @return 0 on success, GIT_ENOTFOUND, GIT_EINVALIDSPEC or an error code.
+ */
+GIT_EXTERN(int) git_reference_lookup(git_reference **out, git_repository *repo, const char *name);
+
+/**
+ * Lookup a reference by name and resolve immediately to OID.
+ *
+ * This function provides a quick way to resolve a reference name straight
+ * through to the object id that it refers to.  This avoids having to
+ * allocate or free any `git_reference` objects for simple situations.
+ *
+ * The name will be checked for validity.
+ * See `git_reference_symbolic_create()` for rules about valid names.
+ *
+ * @param out Pointer to oid to be filled in
+ * @param repo The repository in which to look up the reference
+ * @param name The long name for the reference (e.g. HEAD, refs/heads/master, refs/tags/v0.1.0, ...)
+ * @return 0 on success, GIT_ENOTFOUND, GIT_EINVALIDSPEC or an error code.
+ */
+GIT_EXTERN(int) git_reference_name_to_id(
+	git_oid *out, git_repository *repo, const char *name);
+
+/**
+ * Lookup a reference by DWIMing its short name
+ *
+ * Apply the git precendence rules to the given shorthand to determine
+ * which reference the user is referring to.
+ *
+ * @param out pointer in which to store the reference
+ * @param repo the repository in which to look
+ * @param shorthand the short name for the reference
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_reference_dwim(git_reference **out, git_repository *repo, const char *shorthand);
+
+/**
+ * Conditionally create a new symbolic reference.
+ *
+ * A symbolic reference is a reference name that refers to another
+ * reference name.  If the other name moves, the symbolic name will move,
+ * too.  As a simple example, the "HEAD" reference might refer to
+ * "refs/heads/master" while on the "master" branch of a repository.
+ *
+ * The symbolic reference will be created in the repository and written to
+ * the disk.  The generated reference object must be freed by the user.
+ *
+ * Valid reference names must follow one of two patterns:
+ *
+ * 1. Top-level names must contain only capital letters and underscores,
+ *    and must begin and end with a letter. (e.g. "HEAD", "ORIG_HEAD").
+ * 2. Names prefixed with "refs/" can be almost anything.  You must avoid
+ *    the characters '~', '^', ':', '\\', '?', '[', and '*', and the
+ *    sequences ".." and "@{" which have special meaning to revparse.
+ *
+ * This function will return an error if a reference already exists with the
+ * given name unless `force` is true, in which case it will be overwritten.
+ *
+ * The message for the reflog will be ignored if the reference does
+ * not belong in the standard set (HEAD, branches and remote-tracking
+ * branches) and it does not have a reflog.
+ *
+ * It will return GIT_EMODIFIED if the reference's value at the time
+ * of updating does not match the one passed through `current_value`
+ * (i.e. if the ref has changed since the user read it).
+ *
+ * @param out Pointer to the newly created reference
+ * @param repo Repository where that reference will live
+ * @param name The name of the reference
+ * @param target The target of the reference
+ * @param force Overwrite existing references
+ * @param current_value The expected value of the reference when updating
+ * @param log_message The one line long message to be appended to the reflog
+ * @return 0 on success, GIT_EEXISTS, GIT_EINVALIDSPEC, GIT_EMODIFIED or an error code
+ */
+GIT_EXTERN(int) git_reference_symbolic_create_matching(git_reference **out, git_repository *repo, const char *name, const char *target, int force, const char *current_value, const char *log_message);
+
+/**
+ * Create a new symbolic reference.
+ *
+ * A symbolic reference is a reference name that refers to another
+ * reference name.  If the other name moves, the symbolic name will move,
+ * too.  As a simple example, the "HEAD" reference might refer to
+ * "refs/heads/master" while on the "master" branch of a repository.
+ *
+ * The symbolic reference will be created in the repository and written to
+ * the disk.  The generated reference object must be freed by the user.
+ *
+ * Valid reference names must follow one of two patterns:
+ *
+ * 1. Top-level names must contain only capital letters and underscores,
+ *    and must begin and end with a letter. (e.g. "HEAD", "ORIG_HEAD").
+ * 2. Names prefixed with "refs/" can be almost anything.  You must avoid
+ *    the characters '~', '^', ':', '\\', '?', '[', and '*', and the
+ *    sequences ".." and "@{" which have special meaning to revparse.
+ *
+ * This function will return an error if a reference already exists with the
+ * given name unless `force` is true, in which case it will be overwritten.
+ *
+ * The message for the reflog will be ignored if the reference does
+ * not belong in the standard set (HEAD, branches and remote-tracking
+ * branches) and it does not have a reflog.
+ *
+ * @param out Pointer to the newly created reference
+ * @param repo Repository where that reference will live
+ * @param name The name of the reference
+ * @param target The target of the reference
+ * @param force Overwrite existing references
+ * @param log_message The one line long message to be appended to the reflog
+ * @return 0 on success, GIT_EEXISTS, GIT_EINVALIDSPEC or an error code
+ */
+GIT_EXTERN(int) git_reference_symbolic_create(git_reference **out, git_repository *repo, const char *name, const char *target, int force, const char *log_message);
+
+/**
+ * Create a new direct reference.
+ *
+ * A direct reference (also called an object id reference) refers directly
+ * to a specific object id (a.k.a. OID or SHA) in the repository.  The id
+ * permanently refers to the object (although the reference itself can be
+ * moved).  For example, in libgit2 the direct ref "refs/tags/v0.17.0"
+ * refers to OID 5b9fac39d8a76b9139667c26a63e6b3f204b3977.
+ *
+ * The direct reference will be created in the repository and written to
+ * the disk.  The generated reference object must be freed by the user.
+ *
+ * Valid reference names must follow one of two patterns:
+ *
+ * 1. Top-level names must contain only capital letters and underscores,
+ *    and must begin and end with a letter. (e.g. "HEAD", "ORIG_HEAD").
+ * 2. Names prefixed with "refs/" can be almost anything.  You must avoid
+ *    the characters '~', '^', ':', '\\', '?', '[', and '*', and the
+ *    sequences ".." and "@{" which have special meaning to revparse.
+ *
+ * This function will return an error if a reference already exists with the
+ * given name unless `force` is true, in which case it will be overwritten.
+ *
+ * The message for the reflog will be ignored if the reference does
+ * not belong in the standard set (HEAD, branches and remote-tracking
+ * branches) and and it does not have a reflog.
+ *
+ * @param out Pointer to the newly created reference
+ * @param repo Repository where that reference will live
+ * @param name The name of the reference
+ * @param id The object id pointed to by the reference.
+ * @param force Overwrite existing references
+ * @param log_message The one line long message to be appended to the reflog
+ * @return 0 on success, GIT_EEXISTS, GIT_EINVALIDSPEC or an error code
+ */
+GIT_EXTERN(int) git_reference_create(git_reference **out, git_repository *repo, const char *name, const git_oid *id, int force, const char *log_message);
+
+/**
+ * Conditionally create new direct reference
+ *
+ * A direct reference (also called an object id reference) refers directly
+ * to a specific object id (a.k.a. OID or SHA) in the repository.  The id
+ * permanently refers to the object (although the reference itself can be
+ * moved).  For example, in libgit2 the direct ref "refs/tags/v0.17.0"
+ * refers to OID 5b9fac39d8a76b9139667c26a63e6b3f204b3977.
+ *
+ * The direct reference will be created in the repository and written to
+ * the disk.  The generated reference object must be freed by the user.
+ *
+ * Valid reference names must follow one of two patterns:
+ *
+ * 1. Top-level names must contain only capital letters and underscores,
+ *    and must begin and end with a letter. (e.g. "HEAD", "ORIG_HEAD").
+ * 2. Names prefixed with "refs/" can be almost anything.  You must avoid
+ *    the characters '~', '^', ':', '\\', '?', '[', and '*', and the
+ *    sequences ".." and "@{" which have special meaning to revparse.
+ *
+ * This function will return an error if a reference already exists with the
+ * given name unless `force` is true, in which case it will be overwritten.
+ *
+ * The message for the reflog will be ignored if the reference does
+ * not belong in the standard set (HEAD, branches and remote-tracking
+ * branches) and and it does not have a reflog.
+ *
+ * It will return GIT_EMODIFIED if the reference's value at the time
+ * of updating does not match the one passed through `current_id`
+ * (i.e. if the ref has changed since the user read it).
+ *
+ * @param out Pointer to the newly created reference
+ * @param repo Repository where that reference will live
+ * @param name The name of the reference
+ * @param id The object id pointed to by the reference.
+ * @param force Overwrite existing references
+ * @param current_id The expected value of the reference at the time of update
+ * @param log_message The one line long message to be appended to the reflog
+ * @return 0 on success, GIT_EMODIFIED if the value of the reference
+ * has changed, GIT_EEXISTS, GIT_EINVALIDSPEC or an error code
+ */
+GIT_EXTERN(int) git_reference_create_matching(git_reference **out, git_repository *repo, const char *name, const git_oid *id, int force, const git_oid *current_id, const char *log_message);
+
+/**
+ * Get the OID pointed to by a direct reference.
+ *
+ * Only available if the reference is direct (i.e. an object id reference,
+ * not a symbolic one).
+ *
+ * To find the OID of a symbolic ref, call `git_reference_resolve()` and
+ * then this function (or maybe use `git_reference_name_to_id()` to
+ * directly resolve a reference name all the way through to an OID).
+ *
+ * @param ref The reference
+ * @return a pointer to the oid if available, NULL otherwise
+ */
+GIT_EXTERN(const git_oid *) git_reference_target(const git_reference *ref);
+
+/**
+ * Return the peeled OID target of this reference.
+ *
+ * This peeled OID only applies to direct references that point to
+ * a hard Tag object: it is the result of peeling such Tag.
+ *
+ * @param ref The reference
+ * @return a pointer to the oid if available, NULL otherwise
+ */
+GIT_EXTERN(const git_oid *) git_reference_target_peel(const git_reference *ref);
+
+/**
+ * Get full name to the reference pointed to by a symbolic reference.
+ *
+ * Only available if the reference is symbolic.
+ *
+ * @param ref The reference
+ * @return a pointer to the name if available, NULL otherwise
+ */
+GIT_EXTERN(const char *) git_reference_symbolic_target(const git_reference *ref);
+
+/**
+ * Get the type of a reference.
+ *
+ * Either direct (GIT_REF_OID) or symbolic (GIT_REF_SYMBOLIC)
+ *
+ * @param ref The reference
+ * @return the type
+ */
+GIT_EXTERN(git_ref_t) git_reference_type(const git_reference *ref);
+
+/**
+ * Get the full name of a reference.
+ *
+ * See `git_reference_symbolic_create()` for rules about valid names.
+ *
+ * @param ref The reference
+ * @return the full name for the ref
+ */
+GIT_EXTERN(const char *) git_reference_name(const git_reference *ref);
+
+/**
+ * Resolve a symbolic reference to a direct reference.
+ *
+ * This method iteratively peels a symbolic reference until it resolves to
+ * a direct reference to an OID.
+ *
+ * The peeled reference is returned in the `resolved_ref` argument, and
+ * must be freed manually once it's no longer needed.
+ *
+ * If a direct reference is passed as an argument, a copy of that
+ * reference is returned. This copy must be manually freed too.
+ *
+ * @param out Pointer to the peeled reference
+ * @param ref The reference
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_reference_resolve(git_reference **out, const git_reference *ref);
+
+/**
+ * Get the repository where a reference resides.
+ *
+ * @param ref The reference
+ * @return a pointer to the repo
+ */
+GIT_EXTERN(git_repository *) git_reference_owner(const git_reference *ref);
+
+/**
+ * Create a new reference with the same name as the given reference but a
+ * different symbolic target. The reference must be a symbolic reference,
+ * otherwise this will fail.
+ *
+ * The new reference will be written to disk, overwriting the given reference.
+ *
+ * The target name will be checked for validity.
+ * See `git_reference_symbolic_create()` for rules about valid names.
+ *
+ * The message for the reflog will be ignored if the reference does
+ * not belong in the standard set (HEAD, branches and remote-tracking
+ * branches) and and it does not have a reflog.
+ *
+ * @param out Pointer to the newly created reference
+ * @param ref The reference
+ * @param target The new target for the reference
+ * @param log_message The one line long message to be appended to the reflog
+ * @return 0 on success, GIT_EINVALIDSPEC or an error code
+ */
+GIT_EXTERN(int) git_reference_symbolic_set_target(
+	git_reference **out,
+	git_reference *ref,
+	const char *target,
+	const char *log_message);
+
+/**
+ * Conditionally create a new reference with the same name as the given reference but a
+ * different OID target. The reference must be a direct reference, otherwise
+ * this will fail.
+ *
+ * The new reference will be written to disk, overwriting the given reference.
+ *
+ * @param out Pointer to the newly created reference
+ * @param ref The reference
+ * @param id The new target OID for the reference
+ * @param log_message The one line long message to be appended to the reflog
+ * @return 0 on success, GIT_EMODIFIED if the value of the reference
+ * has changed since it was read, or an error code
+ */
+GIT_EXTERN(int) git_reference_set_target(
+	git_reference **out,
+	git_reference *ref,
+	const git_oid *id,
+	const char *log_message);
+
+/**
+ * Rename an existing reference.
+ *
+ * This method works for both direct and symbolic references.
+ *
+ * The new name will be checked for validity.
+ * See `git_reference_symbolic_create()` for rules about valid names.
+ *
+ * If the `force` flag is not enabled, and there's already
+ * a reference with the given name, the renaming will fail.
+ *
+ * IMPORTANT:
+ * The user needs to write a proper reflog entry if the
+ * reflog is enabled for the repository. We only rename
+ * the reflog if it exists.
+ *
+ * @param ref The reference to rename
+ * @param new_name The new name for the reference
+ * @param force Overwrite an existing reference
+ * @param log_message The one line long message to be appended to the reflog
+ * @return 0 on success, GIT_EINVALIDSPEC, GIT_EEXISTS or an error code
+ *
+ */
+GIT_EXTERN(int) git_reference_rename(
+	git_reference **new_ref,
+	git_reference *ref,
+	const char *new_name,
+	int force,
+	const char *log_message);
+
+/**
+ * Delete an existing reference.
+ *
+ * This method works for both direct and symbolic references.  The reference
+ * will be immediately removed on disk but the memory will not be freed.
+ * Callers must call `git_reference_free`.
+ *
+ * This function will return an error if the reference has changed
+ * from the time it was looked up.
+ *
+ * @param ref The reference to remove
+ * @return 0, GIT_EMODIFIED or an error code
+ */
+GIT_EXTERN(int) git_reference_delete(git_reference *ref);
+
+/**
+ * Delete an existing reference by name
+ *
+ * This method removes the named reference from the repository without
+ * looking at its old value.
+ *
+ * @param name The reference to remove
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_reference_remove(git_repository *repo, const char *name);
+
+/**
+ * Fill a list with all the references that can be found in a repository.
+ *
+ * The string array will be filled with the names of all references; these
+ * values are owned by the user and should be free'd manually when no
+ * longer needed, using `git_strarray_free()`.
+ *
+ * @param array Pointer to a git_strarray structure where
+ *		the reference names will be stored
+ * @param repo Repository where to find the refs
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_reference_list(git_strarray *array, git_repository *repo);
+
+typedef int (*git_reference_foreach_cb)(git_reference *reference, void *payload);
+typedef int (*git_reference_foreach_name_cb)(const char *name, void *payload);
+
+/**
+ * Perform a callback on each reference in the repository.
+ *
+ * The `callback` function will be called for each reference in the
+ * repository, receiving the reference object and the `payload` value
+ * passed to this method.  Returning a non-zero value from the callback
+ * will terminate the iteration.
+ *
+ * Note that the callback function is responsible to call `git_reference_free`
+ * on each reference passed to it.
+ *
+ * @param repo Repository where to find the refs
+ * @param callback Function which will be called for every listed ref
+ * @param payload Additional data to pass to the callback
+ * @return 0 on success, non-zero callback return value, or error code
+ */
+GIT_EXTERN(int) git_reference_foreach(
+	git_repository *repo,
+	git_reference_foreach_cb callback,
+	void *payload);
+
+/**
+ * Perform a callback on the fully-qualified name of each reference.
+ *
+ * The `callback` function will be called for each reference in the
+ * repository, receiving the name of the reference and the `payload` value
+ * passed to this method.  Returning a non-zero value from the callback
+ * will terminate the iteration.
+ *
+ * @param repo Repository where to find the refs
+ * @param callback Function which will be called for every listed ref name
+ * @param payload Additional data to pass to the callback
+ * @return 0 on success, non-zero callback return value, or error code
+ */
+GIT_EXTERN(int) git_reference_foreach_name(
+	git_repository *repo,
+	git_reference_foreach_name_cb callback,
+	void *payload);
+
+/**
+ * Create a copy of an existing reference.
+ *
+ * Call `git_reference_free` to free the data.
+ *
+ * @param dest pointer where to store the copy
+ * @param source object to copy
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_reference_dup(git_reference **dest, git_reference *source);
+
+/**
+ * Free the given reference.
+ *
+ * @param ref git_reference
+ */
+GIT_EXTERN(void) git_reference_free(git_reference *ref);
+
+/**
+ * Compare two references.
+ *
+ * @param ref1 The first git_reference
+ * @param ref2 The second git_reference
+ * @return 0 if the same, else a stable but meaningless ordering.
+ */
+GIT_EXTERN(int) git_reference_cmp(
+	const git_reference *ref1,
+	const git_reference *ref2);
+
+/**
+ * Create an iterator for the repo's references
+ *
+ * @param out pointer in which to store the iterator
+ * @param repo the repository
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_reference_iterator_new(
+	git_reference_iterator **out,
+	git_repository *repo);
+
+/**
+ * Create an iterator for the repo's references that match the
+ * specified glob
+ *
+ * @param out pointer in which to store the iterator
+ * @param repo the repository
+ * @param glob the glob to match against the reference names
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_reference_iterator_glob_new(
+	git_reference_iterator **out,
+	git_repository *repo,
+	const char *glob);
+
+/**
+ * Get the next reference
+ *
+ * @param out pointer in which to store the reference
+ * @param iter the iterator
+ * @return 0, GIT_ITEROVER if there are no more; or an error code
+ */
+GIT_EXTERN(int) git_reference_next(git_reference **out, git_reference_iterator *iter);
+
+/**
+ * Get the next reference's name
+ *
+ * This function is provided for convenience in case only the names
+ * are interesting as it avoids the allocation of the `git_reference`
+ * object which `git_reference_next()` needs.
+ *
+ * @param out pointer in which to store the string
+ * @param iter the iterator
+ * @return 0, GIT_ITEROVER if there are no more; or an error code
+ */
+GIT_EXTERN(int) git_reference_next_name(const char **out, git_reference_iterator *iter);
+
+/**
+ * Free the iterator and its associated resources
+ *
+ * @param iter the iterator to free
+ */
+GIT_EXTERN(void) git_reference_iterator_free(git_reference_iterator *iter);
+
+/**
+ * Perform a callback on each reference in the repository whose name
+ * matches the given pattern.
+ *
+ * This function acts like `git_reference_foreach()` with an additional
+ * pattern match being applied to the reference name before issuing the
+ * callback function.  See that function for more information.
+ *
+ * The pattern is matched using fnmatch or "glob" style where a '*' matches
+ * any sequence of letters, a '?' matches any letter, and square brackets
+ * can be used to define character ranges (such as "[0-9]" for digits).
+ *
+ * @param repo Repository where to find the refs
+ * @param glob Pattern to match (fnmatch-style) against reference name.
+ * @param callback Function which will be called for every listed ref
+ * @param payload Additional data to pass to the callback
+ * @return 0 on success, GIT_EUSER on non-zero callback, or error code
+ */
+GIT_EXTERN(int) git_reference_foreach_glob(
+	git_repository *repo,
+	const char *glob,
+	git_reference_foreach_name_cb callback,
+	void *payload);
+
+/**
+ * Check if a reflog exists for the specified reference.
+ *
+ * @param repo the repository
+ * @param refname the reference's name
+ * @return 0 when no reflog can be found, 1 when it exists;
+ * otherwise an error code.
+ */
+GIT_EXTERN(int) git_reference_has_log(git_repository *repo, const char *refname);
+
+/**
+ * Ensure there is a reflog for a particular reference.
+ *
+ * Make sure that successive updates to the reference will append to
+ * its log.
+ *
+ * @param repo the repository
+ * @param refname the reference's name
+ * @return 0 or an error code.
+ */
+GIT_EXTERN(int) git_reference_ensure_log(git_repository *repo, const char *refname);
+
+/**
+ * Check if a reference is a local branch.
+ *
+ * @param ref A git reference
+ *
+ * @return 1 when the reference lives in the refs/heads
+ * namespace; 0 otherwise.
+ */
+GIT_EXTERN(int) git_reference_is_branch(const git_reference *ref);
+
+/**
+ * Check if a reference is a remote tracking branch
+ *
+ * @param ref A git reference
+ *
+ * @return 1 when the reference lives in the refs/remotes
+ * namespace; 0 otherwise.
+ */
+GIT_EXTERN(int) git_reference_is_remote(const git_reference *ref);
+
+/**
+ * Check if a reference is a tag
+ *
+ * @param ref A git reference
+ *
+ * @return 1 when the reference lives in the refs/tags
+ * namespace; 0 otherwise.
+ */
+GIT_EXTERN(int) git_reference_is_tag(const git_reference *ref);
+
+/**
+ * Check if a reference is a note
+ *
+ * @param ref A git reference
+ *
+ * @return 1 when the reference lives in the refs/notes
+ * namespace; 0 otherwise.
+ */
+GIT_EXTERN(int) git_reference_is_note(const git_reference *ref);
+
+/**
+ * Normalization options for reference lookup
+ */
+typedef enum {
+	/**
+	 * No particular normalization.
+	 */
+	GIT_REF_FORMAT_NORMAL = 0u,
+
+	/**
+	 * Control whether one-level refnames are accepted
+	 * (i.e., refnames that do not contain multiple /-separated
+	 * components). Those are expected to be written only using
+	 * uppercase letters and underscore (FETCH_HEAD, ...)
+	 */
+	GIT_REF_FORMAT_ALLOW_ONELEVEL = (1u << 0),
+
+	/**
+	 * Interpret the provided name as a reference pattern for a
+	 * refspec (as used with remote repositories). If this option
+	 * is enabled, the name is allowed to contain a single * (<star>)
+	 * in place of a one full pathname component
+	 * (e.g., foo/<star>/bar but not foo/bar<star>).
+	 */
+	GIT_REF_FORMAT_REFSPEC_PATTERN = (1u << 1),
+
+	/**
+	 * Interpret the name as part of a refspec in shorthand form
+	 * so the `ONELEVEL` naming rules aren't enforced and 'master'
+	 * becomes a valid name.
+	 */
+	GIT_REF_FORMAT_REFSPEC_SHORTHAND = (1u << 2),
+} git_reference_normalize_t;
+
+/**
+ * Normalize reference name and check validity.
+ *
+ * This will normalize the reference name by removing any leading slash
+ * '/' characters and collapsing runs of adjacent slashes between name
+ * components into a single slash.
+ *
+ * Once normalized, if the reference name is valid, it will be returned in
+ * the user allocated buffer.
+ *
+ * See `git_reference_symbolic_create()` for rules about valid names.
+ *
+ * @param buffer_out User allocated buffer to store normalized name
+ * @param buffer_size Size of buffer_out
+ * @param name Reference name to be checked.
+ * @param flags Flags to constrain name validation rules - see the
+ *              GIT_REF_FORMAT constants above.
+ * @return 0 on success, GIT_EBUFS if buffer is too small, GIT_EINVALIDSPEC
+ * or an error code.
+ */
+GIT_EXTERN(int) git_reference_normalize_name(
+	char *buffer_out,
+	size_t buffer_size,
+	const char *name,
+	unsigned int flags);
+
+/**
+ * Recursively peel reference until object of the specified type is found.
+ *
+ * The retrieved `peeled` object is owned by the repository
+ * and should be closed with the `git_object_free` method.
+ *
+ * If you pass `GIT_OBJ_ANY` as the target type, then the object
+ * will be peeled until a non-tag object is met.
+ *
+ * @param out Pointer to the peeled git_object
+ * @param ref The reference to be processed
+ * @param type The type of the requested object (GIT_OBJ_COMMIT,
+ * GIT_OBJ_TAG, GIT_OBJ_TREE, GIT_OBJ_BLOB or GIT_OBJ_ANY).
+ * @return 0 on success, GIT_EAMBIGUOUS, GIT_ENOTFOUND or an error code
+ */
+GIT_EXTERN(int) git_reference_peel(
+	git_object **out,
+	git_reference *ref,
+	git_otype type);
+
+/**
+ * Ensure the reference name is well-formed.
+ *
+ * Valid reference names must follow one of two patterns:
+ *
+ * 1. Top-level names must contain only capital letters and underscores,
+ *    and must begin and end with a letter. (e.g. "HEAD", "ORIG_HEAD").
+ * 2. Names prefixed with "refs/" can be almost anything.  You must avoid
+ *    the characters '~', '^', ':', '\\', '?', '[', and '*', and the
+ *    sequences ".." and "@{" which have special meaning to revparse.
+ *
+ * @param refname name to be checked.
+ * @return 1 if the reference name is acceptable; 0 if it isn't
+ */
+GIT_EXTERN(int) git_reference_is_valid_name(const char *refname);
+
+/**
+ * Get the reference's short name
+ *
+ * This will transform the reference name into a name "human-readable"
+ * version. If no shortname is appropriate, it will return the full
+ * name.
+ *
+ * The memory is owned by the reference and must not be freed.
+ *
+ * @param ref a reference
+ * @return the human-readable version of the name
+ */
+GIT_EXTERN(const char *) git_reference_shorthand(const git_reference *ref);
+
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/refspec.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/refspec.h b/vendor/libgit2-sys/libgit2/include/git2/refspec.h
new file mode 100644
index 0000000..9acdc72
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/refspec.h
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_refspec_h__
+#define INCLUDE_git_refspec_h__
+
+#include "common.h"
+#include "types.h"
+#include "net.h"
+#include "buffer.h"
+
+/**
+ * @file git2/refspec.h
+ * @brief Git refspec attributes
+ * @defgroup git_refspec Git refspec attributes
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Get the source specifier
+ *
+ * @param refspec the refspec
+ * @return the refspec's source specifier
+ */
+GIT_EXTERN(const char *) git_refspec_src(const git_refspec *refspec);
+
+/**
+ * Get the destination specifier
+ *
+ * @param refspec the refspec
+ * @return the refspec's destination specifier
+ */
+GIT_EXTERN(const char *) git_refspec_dst(const git_refspec *refspec);
+
+/**
+ * Get the refspec's string
+ *
+ * @param refspec the refspec
+ * @returns the refspec's original string
+ */
+GIT_EXTERN(const char *) git_refspec_string(const git_refspec *refspec);
+
+/**
+ * Get the force update setting
+ *
+ * @param refspec the refspec
+ * @return 1 if force update has been set, 0 otherwise
+ */
+GIT_EXTERN(int) git_refspec_force(const git_refspec *refspec);
+
+/**
+ * Get the refspec's direction.
+ *
+ * @param spec refspec
+ * @return GIT_DIRECTION_FETCH or GIT_DIRECTION_PUSH
+ */
+GIT_EXTERN(git_direction) git_refspec_direction(const git_refspec *spec);
+
+/**
+ * Check if a refspec's source descriptor matches a reference 
+ *
+ * @param refspec the refspec
+ * @param refname the name of the reference to check
+ * @return 1 if the refspec matches, 0 otherwise
+ */
+GIT_EXTERN(int) git_refspec_src_matches(const git_refspec *refspec, const char *refname);
+
+/**
+ * Check if a refspec's destination descriptor matches a reference
+ *
+ * @param refspec the refspec
+ * @param refname the name of the reference to check
+ * @return 1 if the refspec matches, 0 otherwise
+ */
+GIT_EXTERN(int) git_refspec_dst_matches(const git_refspec *refspec, const char *refname);
+
+/**
+ * Transform a reference to its target following the refspec's rules
+ *
+ * @param out where to store the target name
+ * @param spec the refspec
+ * @param name the name of the reference to transform
+ * @return 0, GIT_EBUFS or another error
+ */
+GIT_EXTERN(int) git_refspec_transform(git_buf *out, const git_refspec *spec, const char *name);
+
+/**
+ * Transform a target reference to its source reference following the refspec's rules
+ *
+ * @param out where to store the source reference name
+ * @param spec the refspec
+ * @param name the name of the reference to transform
+ * @return 0, GIT_EBUFS or another error
+ */
+GIT_EXTERN(int) git_refspec_rtransform(git_buf *out, const git_refspec *spec, const char *name);
+
+GIT_END_DECL
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/remote.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/remote.h b/vendor/libgit2-sys/libgit2/include/git2/remote.h
new file mode 100644
index 0000000..3d463de
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/remote.h
@@ -0,0 +1,854 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_remote_h__
+#define INCLUDE_git_remote_h__
+
+#include "common.h"
+#include "repository.h"
+#include "refspec.h"
+#include "net.h"
+#include "indexer.h"
+#include "strarray.h"
+#include "transport.h"
+#include "pack.h"
+#include "proxy.h"
+
+/**
+ * @file git2/remote.h
+ * @brief Git remote management functions
+ * @defgroup git_remote remote management functions
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Add a remote with the default fetch refspec to the repository's configuration.
+ *
+ * @param out the resulting remote
+ * @param repo the repository in which to create the remote
+ * @param name the remote's name
+ * @param url the remote's url
+ * @return 0, GIT_EINVALIDSPEC, GIT_EEXISTS or an error code
+ */
+GIT_EXTERN(int) git_remote_create(
+		git_remote **out,
+		git_repository *repo,
+		const char *name,
+		const char *url);
+
+/**
+ * Add a remote with the provided fetch refspec (or default if NULL) to the repository's
+ * configuration.
+ *
+ * @param out the resulting remote
+ * @param repo the repository in which to create the remote
+ * @param name the remote's name
+ * @param url the remote's url
+ * @param fetch the remote fetch value
+ * @return 0, GIT_EINVALIDSPEC, GIT_EEXISTS or an error code
+ */
+GIT_EXTERN(int) git_remote_create_with_fetchspec(
+		git_remote **out,
+		git_repository *repo,
+		const char *name,
+		const char *url,
+		const char *fetch);
+
+/**
+ * Create an anonymous remote
+ *
+ * Create a remote with the given url in-memory. You can use this when
+ * you have a URL instead of a remote's name.
+ *
+ * @param out pointer to the new remote objects
+ * @param repo the associated repository
+ * @param url the remote repository's URL
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_remote_create_anonymous(
+		git_remote **out,
+		git_repository *repo,
+		const char *url);
+
+/**
+ * Create a remote without a connected local repo
+ *
+ * Create a remote with the given url in-memory. You can use this when
+ * you have a URL instead of a remote's name.
+ *
+ * Contrasted with git_remote_create_anonymous, a detached remote
+ * will not consider any repo configuration values (such as insteadof url
+ * substitutions).
+ *
+ * @param out pointer to the new remote objects
+ * @param url the remote repository's URL
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_remote_create_detached(
+		git_remote **out,
+		const char *url);
+
+/**
+ * Get the information for a particular remote
+ *
+ * The name will be checked for validity.
+ * See `git_tag_create()` for rules about valid names.
+ *
+ * @param out pointer to the new remote object
+ * @param repo the associated repository
+ * @param name the remote's name
+ * @return 0, GIT_ENOTFOUND, GIT_EINVALIDSPEC or an error code
+ */
+GIT_EXTERN(int) git_remote_lookup(git_remote **out, git_repository *repo, const char *name);
+
+/**
+ * Create a copy of an existing remote.  All internal strings are also
+ * duplicated. Callbacks are not duplicated.
+ *
+ * Call `git_remote_free` to free the data.
+ *
+ * @param dest pointer where to store the copy
+ * @param source object to copy
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_remote_dup(git_remote **dest, git_remote *source);
+
+/**
+ * Get the remote's repository
+ *
+ * @param remote the remote
+ * @return a pointer to the repository
+ */
+GIT_EXTERN(git_repository *) git_remote_owner(const git_remote *remote);
+
+/**
+ * Get the remote's name
+ *
+ * @param remote the remote
+ * @return a pointer to the name or NULL for in-memory remotes
+ */
+GIT_EXTERN(const char *) git_remote_name(const git_remote *remote);
+
+/**
+ * Get the remote's url
+ *
+ * If url.*.insteadOf has been configured for this URL, it will
+ * return the modified URL.
+ *
+ * @param remote the remote
+ * @return a pointer to the url
+ */
+GIT_EXTERN(const char *) git_remote_url(const git_remote *remote);
+
+/**
+ * Get the remote's url for pushing
+ *
+ * If url.*.pushInsteadOf has been configured for this URL, it
+ * will return the modified URL.
+ *
+ * @param remote the remote
+ * @return a pointer to the url or NULL if no special url for pushing is set
+ */
+GIT_EXTERN(const char *) git_remote_pushurl(const git_remote *remote);
+
+/**
+ * Set the remote's url in the configuration
+ *
+ * Remote objects already in memory will not be affected. This assumes
+ * the common case of a single-url remote and will otherwise return an error.
+ *
+ * @param repo the repository in which to perform the change
+ * @param remote the remote's name
+ * @param url the url to set
+ * @return 0 or an error value
+ */
+GIT_EXTERN(int) git_remote_set_url(git_repository *repo, const char *remote, const char* url);
+
+/**
+ * Set the remote's url for pushing in the configuration.
+ *
+ * Remote objects already in memory will not be affected. This assumes
+ * the common case of a single-url remote and will otherwise return an error.
+ *
+ *
+ * @param repo the repository in which to perform the change
+ * @param remote the remote's name
+ * @param url the url to set
+ */
+GIT_EXTERN(int) git_remote_set_pushurl(git_repository *repo, const char *remote, const char* url);
+
+/**
+ * Add a fetch refspec to the remote's configuration
+ *
+ * Add the given refspec to the fetch list in the configuration. No
+ * loaded remote instances will be affected.
+ *
+ * @param repo the repository in which to change the configuration
+ * @param remote the name of the remote to change
+ * @param refspec the new fetch refspec
+ * @return 0, GIT_EINVALIDSPEC if refspec is invalid or an error value
+ */
+GIT_EXTERN(int) git_remote_add_fetch(git_repository *repo, const char *remote, const char *refspec);
+
+/**
+ * Get the remote's list of fetch refspecs
+ *
+ * The memory is owned by the user and should be freed with
+ * `git_strarray_free`.
+ *
+ * @param array pointer to the array in which to store the strings
+ * @param remote the remote to query
+ */
+GIT_EXTERN(int) git_remote_get_fetch_refspecs(git_strarray *array, const git_remote *remote);
+
+/**
+ * Add a push refspec to the remote's configuration
+ *
+ * Add the given refspec to the push list in the configuration. No
+ * loaded remote instances will be affected.
+ *
+ * @param repo the repository in which to change the configuration
+ * @param remote the name of the remote to change
+ * @param refspec the new push refspec
+ * @return 0, GIT_EINVALIDSPEC if refspec is invalid or an error value
+ */
+GIT_EXTERN(int) git_remote_add_push(git_repository *repo, const char *remote, const char *refspec);
+
+/**
+ * Get the remote's list of push refspecs
+ *
+ * The memory is owned by the user and should be freed with
+ * `git_strarray_free`.
+ *
+ * @param array pointer to the array in which to store the strings
+ * @param remote the remote to query
+ */
+GIT_EXTERN(int) git_remote_get_push_refspecs(git_strarray *array, const git_remote *remote);
+
+/**
+ * Get the number of refspecs for a remote
+ *
+ * @param remote the remote
+ * @return the amount of refspecs configured in this remote
+ */
+GIT_EXTERN(size_t) git_remote_refspec_count(const git_remote *remote);
+
+/**
+ * Get a refspec from the remote
+ *
+ * @param remote the remote to query
+ * @param n the refspec to get
+ * @return the nth refspec
+ */
+GIT_EXTERN(const git_refspec *)git_remote_get_refspec(const git_remote *remote, size_t n);
+
+/**
+ * Open a connection to a remote
+ *
+ * The transport is selected based on the URL. The direction argument
+ * is due to a limitation of the git protocol (over TCP or SSH) which
+ * starts up a specific binary which can only do the one or the other.
+ *
+ * @param remote the remote to connect to
+ * @param direction GIT_DIRECTION_FETCH if you want to fetch or
+ * GIT_DIRECTION_PUSH if you want to push
+ * @param callbacks the callbacks to use for this connection
+ * @param proxy_opts proxy settings
+ * @param custom_headers extra HTTP headers to use in this connection
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_remote_connect(git_remote *remote, git_direction direction, const git_remote_callbacks *callbacks, const git_proxy_options *proxy_opts, const git_strarray *custom_headers);
+
+/**
+ * Get the remote repository's reference advertisement list
+ *
+ * Get the list of references with which the server responds to a new
+ * connection.
+ *
+ * The remote (or more exactly its transport) must have connected to
+ * the remote repository. This list is available as soon as the
+ * connection to the remote is initiated and it remains available
+ * after disconnecting.
+ *
+ * The memory belongs to the remote. The pointer will be valid as long
+ * as a new connection is not initiated, but it is recommended that
+ * you make a copy in order to make use of the data.
+ *
+ * @param out pointer to the array
+ * @param size the number of remote heads
+ * @param remote the remote
+ * @return 0 on success, or an error code
+ */
+GIT_EXTERN(int) git_remote_ls(const git_remote_head ***out,  size_t *size, git_remote *remote);
+
+/**
+ * Check whether the remote is connected
+ *
+ * Check whether the remote's underlying transport is connected to the
+ * remote host.
+ *
+ * @param remote the remote
+ * @return 1 if it's connected, 0 otherwise.
+ */
+GIT_EXTERN(int) git_remote_connected(const git_remote *remote);
+
+/**
+ * Cancel the operation
+ *
+ * At certain points in its operation, the network code checks whether
+ * the operation has been cancelled and if so stops the operation.
+ *
+ * @param remote the remote
+ */
+GIT_EXTERN(void) git_remote_stop(git_remote *remote);
+
+/**
+ * Disconnect from the remote
+ *
+ * Close the connection to the remote.
+ *
+ * @param remote the remote to disconnect from
+ */
+GIT_EXTERN(void) git_remote_disconnect(git_remote *remote);
+
+/**
+ * Free the memory associated with a remote
+ *
+ * This also disconnects from the remote, if the connection
+ * has not been closed yet (using git_remote_disconnect).
+ *
+ * @param remote the remote to free
+ */
+GIT_EXTERN(void) git_remote_free(git_remote *remote);
+
+/**
+ * Get a list of the configured remotes for a repo
+ *
+ * The string array must be freed by the user.
+ *
+ * @param out a string array which receives the names of the remotes
+ * @param repo the repository to query
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_remote_list(git_strarray *out, git_repository *repo);
+
+/**
+ * Argument to the completion callback which tells it which operation
+ * finished.
+ */
+typedef enum git_remote_completion_type {
+	GIT_REMOTE_COMPLETION_DOWNLOAD,
+	GIT_REMOTE_COMPLETION_INDEXING,
+	GIT_REMOTE_COMPLETION_ERROR,
+} git_remote_completion_type;
+
+/** Push network progress notification function */
+typedef int (*git_push_transfer_progress)(
+	unsigned int current,
+	unsigned int total,
+	size_t bytes,
+	void* payload);
+/**
+ * Represents an update which will be performed on the remote during push
+ */
+typedef struct {
+	/**
+	 * The source name of the reference
+	 */
+	char *src_refname;
+	/**
+	 * The name of the reference to update on the server
+	 */
+	char *dst_refname;
+	/**
+	 * The current target of the reference
+	 */
+	git_oid src;
+	/**
+	 * The new target for the reference
+	 */
+	git_oid dst;
+} git_push_update;
+
+/**
+ * Callback used to inform of upcoming updates.
+ *
+ * @param updates an array containing the updates which will be sent
+ * as commands to the destination.
+ * @param len number of elements in `updates`
+ * @param payload Payload provided by the caller
+ */
+typedef int (*git_push_negotiation)(const git_push_update **updates, size_t len, void *payload);
+
+/**
+ * Callback used to inform of the update status from the remote.
+ *
+ * Called for each updated reference on push. If `status` is
+ * not `NULL`, the update was rejected by the remote server
+ * and `status` contains the reason given.
+ *
+ * @param refname refname specifying to the remote ref
+ * @param status status message sent from the remote
+ * @param data data provided by the caller
+ * @return 0 on success, otherwise an error
+ */
+typedef int (*git_push_update_reference_cb)(const char *refname, const char *status, void *data);
+
+/**
+ * The callback settings structure
+ *
+ * Set the callbacks to be called by the remote when informing the user
+ * about the progress of the network operations.
+ */
+struct git_remote_callbacks {
+	unsigned int version;
+	/**
+	 * Textual progress from the remote. Text send over the
+	 * progress side-band will be passed to this function (this is
+	 * the 'counting objects' output).
+	 */
+	git_transport_message_cb sideband_progress;
+
+	/**
+	 * Completion is called when different parts of the download
+	 * process are done (currently unused).
+	 */
+	int (*completion)(git_remote_completion_type type, void *data);
+
+	/**
+	 * This will be called if the remote host requires
+	 * authentication in order to connect to it.
+	 *
+	 * Returning GIT_PASSTHROUGH will make libgit2 behave as
+	 * though this field isn't set.
+	 */
+	git_cred_acquire_cb credentials;
+
+	/**
+	 * If cert verification fails, this will be called to let the
+	 * user make the final decision of whether to allow the
+	 * connection to proceed. Returns 0 to allow the connection
+	 * or a negative value to indicate an error.
+	 */
+	git_transport_certificate_check_cb certificate_check;
+
+	/**
+	 * During the download of new data, this will be regularly
+	 * called with the current count of progress done by the
+	 * indexer.
+	 */
+	git_transfer_progress_cb transfer_progress;
+
+	/**
+	 * Each time a reference is updated locally, this function
+	 * will be called with information about it.
+	 */
+	int (*update_tips)(const char *refname, const git_oid *a, const git_oid *b, void *data);
+
+	/**
+	 * Function to call with progress information during pack
+	 * building. Be aware that this is called inline with pack
+	 * building operations, so performance may be affected.
+	 */
+	git_packbuilder_progress pack_progress;
+
+	/**
+	 * Function to call with progress information during the
+	 * upload portion of a push. Be aware that this is called
+	 * inline with pack building operations, so performance may be
+	 * affected.
+	 */
+	git_push_transfer_progress push_transfer_progress;
+
+	/**
+	 * See documentation of git_push_update_reference_cb
+	 */
+	git_push_update_reference_cb push_update_reference;
+
+	/**
+	 * Called once between the negotiation step and the upload. It
+	 * provides information about what updates will be performed.
+	 */
+	git_push_negotiation push_negotiation;
+
+	/**
+	 * Create the transport to use for this operation. Leave NULL
+	 * to auto-detect.
+	 */
+	git_transport_cb transport;
+
+	/**
+	 * This will be passed to each of the callbacks in this struct
+	 * as the last parameter.
+	 */
+	void *payload;
+};
+
+#define GIT_REMOTE_CALLBACKS_VERSION 1
+#define GIT_REMOTE_CALLBACKS_INIT {GIT_REMOTE_CALLBACKS_VERSION}
+
+/**
+ * Initializes a `git_remote_callbacks` with default values. Equivalent to
+ * creating an instance with GIT_REMOTE_CALLBACKS_INIT.
+ *
+ * @param opts the `git_remote_callbacks` struct to initialize
+ * @param version Version of struct; pass `GIT_REMOTE_CALLBACKS_VERSION`
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_remote_init_callbacks(
+	git_remote_callbacks *opts,
+	unsigned int version);
+
+typedef enum {
+	/**
+	 * Use the setting from the configuration
+	 */
+	GIT_FETCH_PRUNE_UNSPECIFIED,
+	/**
+	 * Force pruning on
+	 */
+	GIT_FETCH_PRUNE,
+	/**
+	 * Force pruning off
+	 */
+	GIT_FETCH_NO_PRUNE,
+} git_fetch_prune_t;
+
+/**
+ * Automatic tag following option
+ *
+ * Lets us select the --tags option to use.
+ */
+typedef enum {
+	/**
+	 * Use the setting from the configuration.
+	 */
+	GIT_REMOTE_DOWNLOAD_TAGS_UNSPECIFIED = 0,
+	/**
+	 * Ask the server for tags pointing to objects we're already
+	 * downloading.
+	 */
+	GIT_REMOTE_DOWNLOAD_TAGS_AUTO,
+	/**
+	 * Don't ask for any tags beyond the refspecs.
+	 */
+	GIT_REMOTE_DOWNLOAD_TAGS_NONE,
+	/**
+	 * Ask for the all the tags.
+	 */
+	GIT_REMOTE_DOWNLOAD_TAGS_ALL,
+} git_remote_autotag_option_t;
+
+/**
+ * Fetch options structure.
+ *
+ * Zero out for defaults.  Initialize with `GIT_FETCH_OPTIONS_INIT` macro to
+ * correctly set the `version` field.  E.g.
+ *
+ *		git_fetch_options opts = GIT_FETCH_OPTIONS_INIT;
+ */
+typedef struct {
+	int version;
+
+	/**
+	 * Callbacks to use for this fetch operation
+	 */
+	git_remote_callbacks callbacks;
+
+	/**
+	 * Whether to perform a prune after the fetch
+	 */
+	git_fetch_prune_t prune;
+
+	/**
+	 * Whether to write the results to FETCH_HEAD. Defaults to
+	 * on. Leave this default in order to behave like git.
+	 */
+	int update_fetchhead;
+
+	/**
+	 * Determines how to behave regarding tags on the remote, such
+	 * as auto-downloading tags for objects we're downloading or
+	 * downloading all of them.
+	 *
+	 * The default is to auto-follow tags.
+	 */
+	git_remote_autotag_option_t download_tags;
+
+	/**
+	 * Proxy options to use, by default no proxy is used.
+	 */
+	git_proxy_options proxy_opts;
+
+	/**
+	 * Extra headers for this fetch operation
+	 */
+	git_strarray custom_headers;
+} git_fetch_options;
+
+#define GIT_FETCH_OPTIONS_VERSION 1
+#define GIT_FETCH_OPTIONS_INIT { GIT_FETCH_OPTIONS_VERSION, GIT_REMOTE_CALLBACKS_INIT, GIT_FETCH_PRUNE_UNSPECIFIED, 1, \
+				 GIT_REMOTE_DOWNLOAD_TAGS_UNSPECIFIED, GIT_PROXY_OPTIONS_INIT }
+
+/**
+ * Initializes a `git_fetch_options` with default values. Equivalent to
+ * creating an instance with GIT_FETCH_OPTIONS_INIT.
+ *
+ * @param opts the `git_fetch_options` instance to initialize.
+ * @param version the version of the struct; you should pass
+ *        `GIT_FETCH_OPTIONS_VERSION` here.
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_fetch_init_options(
+	git_fetch_options *opts,
+	unsigned int version);
+
+
+/**
+ * Controls the behavior of a git_push object.
+ */
+typedef struct {
+	unsigned int version;
+
+	/**
+	 * If the transport being used to push to the remote requires the creation
+	 * of a pack file, this controls the number of worker threads used by
+	 * the packbuilder when creating that pack file to be sent to the remote.
+	 *
+	 * If set to 0, the packbuilder will auto-detect the number of threads
+	 * to create. The default value is 1.
+	 */
+	unsigned int pb_parallelism;
+
+	/**
+	 * Callbacks to use for this push operation
+	 */
+	git_remote_callbacks callbacks;
+
+	/**
+	* Proxy options to use, by default no proxy is used.
+	*/
+	git_proxy_options proxy_opts;
+
+	/**
+	 * Extra headers for this push operation
+	 */
+	git_strarray custom_headers;
+} git_push_options;
+
+#define GIT_PUSH_OPTIONS_VERSION 1
+#define GIT_PUSH_OPTIONS_INIT { GIT_PUSH_OPTIONS_VERSION, 0, GIT_REMOTE_CALLBACKS_INIT, GIT_PROXY_OPTIONS_INIT }
+
+/**
+ * Initializes a `git_push_options` with default values. Equivalent to
+ * creating an instance with GIT_PUSH_OPTIONS_INIT.
+ *
+ * @param opts the `git_push_options` instance to initialize.
+ * @param version the version of the struct; you should pass
+ *        `GIT_PUSH_OPTIONS_VERSION` here.
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_push_init_options(
+	git_push_options *opts,
+	unsigned int version);
+
+/**
+ * Download and index the packfile
+ *
+ * Connect to the remote if it hasn't been done yet, negotiate with
+ * the remote git which objects are missing, download and index the
+ * packfile.
+ *
+ * The .idx file will be created and both it and the packfile with be
+ * renamed to their final name.
+ *
+ * @param remote the remote
+ * @param refspecs the refspecs to use for this negotiation and
+ * download. Use NULL or an empty array to use the base refspecs
+ * @param opts the options to use for this fetch
+ * @return 0 or an error code
+ */
+ GIT_EXTERN(int) git_remote_download(git_remote *remote, const git_strarray *refspecs, const git_fetch_options *opts);
+
+/**
+ * Create a packfile and send it to the server
+ *
+ * Connect to the remote if it hasn't been done yet, negotiate with
+ * the remote git which objects are missing, create a packfile with the missing objects and send it.
+ *
+ * @param remote the remote
+ * @param refspecs the refspecs to use for this negotiation and
+ * upload. Use NULL or an empty array to use the base refspecs
+ * @param opts the options to use for this push
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_remote_upload(git_remote *remote, const git_strarray *refspecs, const git_push_options *opts);
+
+/**
+ * Update the tips to the new state
+ *
+ * @param remote the remote to update
+ * @param reflog_message The message to insert into the reflogs. If
+ * NULL and fetching, the default is "fetch <name>", where <name> is
+ * the name of the remote (or its url, for in-memory remotes). This
+ * parameter is ignored when pushing.
+ * @param callbacks  pointer to the callback structure to use
+ * @param update_fetchhead whether to write to FETCH_HEAD. Pass 1 to behave like git.
+ * @param download_tags what the behaviour for downloading tags is for this fetch. This is
+ * ignored for push. This must be the same value passed to `git_remote_download()`.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_remote_update_tips(
+		git_remote *remote,
+		const git_remote_callbacks *callbacks,
+		int update_fetchhead,
+		git_remote_autotag_option_t download_tags,
+		const char *reflog_message);
+
+/**
+ * Download new data and update tips
+ *
+ * Convenience function to connect to a remote, download the data,
+ * disconnect and update the remote-tracking branches.
+ *
+ * @param remote the remote to fetch from
+ * @param refspecs the refspecs to use for this fetch. Pass NULL or an
+ *                 empty array to use the base refspecs.
+ * @param opts options to use for this fetch
+ * @param reflog_message The message to insert into the reflogs. If NULL, the
+ *								 default is "fetch"
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_remote_fetch(
+		git_remote *remote,
+		const git_strarray *refspecs,
+		const git_fetch_options *opts,
+		const char *reflog_message);
+
+/**
+ * Prune tracking refs that are no longer present on remote
+ *
+ * @param remote the remote to prune
+ * @param callbacks callbacks to use for this prune
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_remote_prune(git_remote *remote, const git_remote_callbacks *callbacks);
+
+/**
+ * Perform a push
+ *
+ * Peform all the steps from a push.
+ *
+ * @param remote the remote to push to
+ * @param refspecs the refspecs to use for pushing. If NULL or an empty
+ *                 array, the configured refspecs will be used
+ * @param opts options to use for this push
+ */
+GIT_EXTERN(int) git_remote_push(git_remote *remote,
+				const git_strarray *refspecs,
+				const git_push_options *opts);
+
+/**
+ * Get the statistics structure that is filled in by the fetch operation.
+ */
+GIT_EXTERN(const git_transfer_progress *) git_remote_stats(git_remote *remote);
+
+/**
+ * Retrieve the tag auto-follow setting
+ *
+ * @param remote the remote to query
+ * @return the auto-follow setting
+ */
+GIT_EXTERN(git_remote_autotag_option_t) git_remote_autotag(const git_remote *remote);
+
+/**
+ * Set the remote's tag following setting.
+ *
+ * The change will be made in the configuration. No loaded remotes
+ * will be affected.
+ *
+ * @param repo the repository in which to make the change
+ * @param remote the name of the remote
+ * @param value the new value to take.
+ */
+GIT_EXTERN(int) git_remote_set_autotag(git_repository *repo, const char *remote, git_remote_autotag_option_t value);
+/**
+ * Retrieve the ref-prune setting
+ *
+ * @param remote the remote to query
+ * @return the ref-prune setting
+ */
+GIT_EXTERN(int) git_remote_prune_refs(const git_remote *remote);
+
+/**
+ * Give the remote a new name
+ *
+ * All remote-tracking branches and configuration settings
+ * for the remote are updated.
+ *
+ * The new name will be checked for validity.
+ * See `git_tag_create()` for rules about valid names.
+ *
+ * No loaded instances of a the remote with the old name will change
+ * their name or their list of refspecs.
+ *
+ * @param problems non-default refspecs cannot be renamed and will be
+ * stored here for further processing by the caller. Always free this
+ * strarray on successful return.
+ * @param repo the repository in which to rename
+ * @param name the current name of the remote
+ * @param new_name the new name the remote should bear
+ * @return 0, GIT_EINVALIDSPEC, GIT_EEXISTS or an error code
+ */
+GIT_EXTERN(int) git_remote_rename(
+	git_strarray *problems,
+	git_repository *repo,
+	const char *name,
+	const char *new_name);
+
+/**
+ * Ensure the remote name is well-formed.
+ *
+ * @param remote_name name to be checked.
+ * @return 1 if the reference name is acceptable; 0 if it isn't
+ */
+GIT_EXTERN(int) git_remote_is_valid_name(const char *remote_name);
+
+/**
+* Delete an existing persisted remote.
+*
+* All remote-tracking branches and configuration settings
+* for the remote will be removed.
+*
+* @param repo the repository in which to act
+* @param name the name of the remote to delete
+* @return 0 on success, or an error code.
+*/
+GIT_EXTERN(int) git_remote_delete(git_repository *repo, const char *name);
+
+/**
+ * Retrieve the name of the remote's default branch
+ *
+ * The default branch of a repository is the branch which HEAD points
+ * to. If the remote does not support reporting this information
+ * directly, it performs the guess as git does; that is, if there are
+ * multiple branches which point to the same commit, the first one is
+ * chosen. If the master branch is a candidate, it wins.
+ *
+ * This function must only be called after connecting.
+ *
+ * @param out the buffern in which to store the reference name
+ * @param remote the remote
+ * @return 0, GIT_ENOTFOUND if the remote does not have any references
+ * or none of them point to HEAD's commit, or an error message.
+ */
+GIT_EXTERN(int) git_remote_default_branch(git_buf *out, git_remote *remote);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/repository.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/repository.h b/vendor/libgit2-sys/libgit2/include/git2/repository.h
new file mode 100644
index 0000000..6e0c1f7
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/repository.h
@@ -0,0 +1,866 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_repository_h__
+#define INCLUDE_git_repository_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+#include "buffer.h"
+
+/**
+ * @file git2/repository.h
+ * @brief Git repository management routines
+ * @defgroup git_repository Git repository management routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Open a git repository.
+ *
+ * The 'path' argument must point to either a git repository
+ * folder, or an existing work dir.
+ *
+ * The method will automatically detect if 'path' is a normal
+ * or bare repository or fail is 'path' is neither.
+ *
+ * @param out pointer to the repo which will be opened
+ * @param path the path to the repository
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_repository_open(git_repository **out, const char *path);
+/**
+ * Open working tree as a repository
+ *
+ * Open the working directory of the working tree as a normal
+ * repository that can then be worked on.
+ *
+ * @param out Output pointer containing opened repository
+ * @param wt Working tree to open
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_repository_open_from_worktree(git_repository **out, git_worktree *wt);
+
+/**
+ * Create a "fake" repository to wrap an object database
+ *
+ * Create a repository object to wrap an object database to be used
+ * with the API when all you have is an object database. This doesn't
+ * have any paths associated with it, so use with care.
+ *
+ * @param out pointer to the repo
+ * @param odb the object database to wrap
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_repository_wrap_odb(git_repository **out, git_odb *odb);
+
+/**
+ * Look for a git repository and copy its path in the given buffer.
+ * The lookup start from base_path and walk across parent directories
+ * if nothing has been found. The lookup ends when the first repository
+ * is found, or when reaching a directory referenced in ceiling_dirs
+ * or when the filesystem changes (in case across_fs is true).
+ *
+ * The method will automatically detect if the repository is bare
+ * (if there is a repository).
+ *
+ * @param out A pointer to a user-allocated git_buf which will contain
+ * the found path.
+ *
+ * @param start_path The base path where the lookup starts.
+ *
+ * @param across_fs If true, then the lookup will not stop when a
+ * filesystem device change is detected while exploring parent directories.
+ *
+ * @param ceiling_dirs A GIT_PATH_LIST_SEPARATOR separated list of
+ * absolute symbolic link free paths. The lookup will stop when any
+ * of this paths is reached. Note that the lookup always performs on
+ * start_path no matter start_path appears in ceiling_dirs ceiling_dirs
+ * might be NULL (which is equivalent to an empty string)
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_repository_discover(
+		git_buf *out,
+		const char *start_path,
+		int across_fs,
+		const char *ceiling_dirs);
+
+/**
+ * Option flags for `git_repository_open_ext`.
+ *
+ * * GIT_REPOSITORY_OPEN_NO_SEARCH - Only open the repository if it can be
+ *   immediately found in the start_path.  Do not walk up from the
+ *   start_path looking at parent directories.
+ * * GIT_REPOSITORY_OPEN_CROSS_FS - Unless this flag is set, open will not
+ *   continue searching across filesystem boundaries (i.e. when `st_dev`
+ *   changes from the `stat` system call).  (E.g. Searching in a user's home
+ *   directory "/home/user/source/" will not return "/.git/" as the found
+ *   repo if "/" is a different filesystem than "/home".)
+ * * GIT_REPOSITORY_OPEN_BARE - Open repository as a bare repo regardless
+ *   of core.bare config, and defer loading config file for faster setup.
+ *   Unlike `git_repository_open_bare`, this can follow gitlinks.
+ * * GIT_REPOSITORY_OPEN_NO_DOTGIT - Do not check for a repository by
+ *   appending /.git to the start_path; only open the repository if
+ *   start_path itself points to the git directory.
+ * * GIT_REPOSITORY_OPEN_FROM_ENV - Find and open a git repository,
+ *   respecting the environment variables used by the git command-line
+ *   tools. If set, `git_repository_open_ext` will ignore the other
+ *   flags and the `ceiling_dirs` argument, and will allow a NULL `path`
+ *   to use `GIT_DIR` or search from the current directory. The search
+ *   for a repository will respect $GIT_CEILING_DIRECTORIES and
+ *   $GIT_DISCOVERY_ACROSS_FILESYSTEM.  The opened repository will
+ *   respect $GIT_INDEX_FILE, $GIT_NAMESPACE, $GIT_OBJECT_DIRECTORY, and
+ *   $GIT_ALTERNATE_OBJECT_DIRECTORIES.  In the future, this flag will
+ *   also cause `git_repository_open_ext` to respect $GIT_WORK_TREE and
+ *   $GIT_COMMON_DIR; currently, `git_repository_open_ext` with this
+ *   flag will error out if either $GIT_WORK_TREE or $GIT_COMMON_DIR is
+ *   set.
+ */
+typedef enum {
+	GIT_REPOSITORY_OPEN_NO_SEARCH = (1 << 0),
+	GIT_REPOSITORY_OPEN_CROSS_FS  = (1 << 1),
+	GIT_REPOSITORY_OPEN_BARE      = (1 << 2),
+	GIT_REPOSITORY_OPEN_NO_DOTGIT = (1 << 3),
+	GIT_REPOSITORY_OPEN_FROM_ENV  = (1 << 4),
+} git_repository_open_flag_t;
+
+/**
+ * Find and open a repository with extended controls.
+ *
+ * @param out Pointer to the repo which will be opened.  This can
+ *        actually be NULL if you only want to use the error code to
+ *        see if a repo at this path could be opened.
+ * @param path Path to open as git repository.  If the flags
+ *        permit "searching", then this can be a path to a subdirectory
+ *        inside the working directory of the repository. May be NULL if
+ *        flags is GIT_REPOSITORY_OPEN_FROM_ENV.
+ * @param flags A combination of the GIT_REPOSITORY_OPEN flags above.
+ * @param ceiling_dirs A GIT_PATH_LIST_SEPARATOR delimited list of path
+ *        prefixes at which the search for a containing repository should
+ *        terminate.
+ * @return 0 on success, GIT_ENOTFOUND if no repository could be found,
+ *        or -1 if there was a repository but open failed for some reason
+ *        (such as repo corruption or system errors).
+ */
+GIT_EXTERN(int) git_repository_open_ext(
+	git_repository **out,
+	const char *path,
+	unsigned int flags,
+	const char *ceiling_dirs);
+
+/**
+ * Open a bare repository on the serverside.
+ *
+ * This is a fast open for bare repositories that will come in handy
+ * if you're e.g. hosting git repositories and need to access them
+ * efficiently
+ *
+ * @param out Pointer to the repo which will be opened.
+ * @param bare_path Direct path to the bare repository
+ * @return 0 on success, or an error code
+ */
+GIT_EXTERN(int) git_repository_open_bare(git_repository **out, const char *bare_path);
+
+/**
+ * Free a previously allocated repository
+ *
+ * Note that after a repository is free'd, all the objects it has spawned
+ * will still exist until they are manually closed by the user
+ * with `git_object_free`, but accessing any of the attributes of
+ * an object without a backing repository will result in undefined
+ * behavior
+ *
+ * @param repo repository handle to close. If NULL nothing occurs.
+ */
+GIT_EXTERN(void) git_repository_free(git_repository *repo);
+
+/**
+ * Creates a new Git repository in the given folder.
+ *
+ * TODO:
+ *	- Reinit the repository
+ *
+ * @param out pointer to the repo which will be created or reinitialized
+ * @param path the path to the repository
+ * @param is_bare if true, a Git repository without a working directory is
+ *		created at the pointed path. If false, provided path will be
+ *		considered as the working directory into which the .git directory
+ *		will be created.
+ *
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_repository_init(
+	git_repository **out,
+	const char *path,
+	unsigned is_bare);
+
+/**
+ * Option flags for `git_repository_init_ext`.
+ *
+ * These flags configure extra behaviors to `git_repository_init_ext`.
+ * In every case, the default behavior is the zero value (i.e. flag is
+ * not set).  Just OR the flag values together for the `flags` parameter
+ * when initializing a new repo.  Details of individual values are:
+ *
+ * * BARE   - Create a bare repository with no working directory.
+ * * NO_REINIT - Return an GIT_EEXISTS error if the repo_path appears to
+ *        already be an git repository.
+ * * NO_DOTGIT_DIR - Normally a "/.git/" will be appended to the repo
+ *        path for non-bare repos (if it is not already there), but
+ *        passing this flag prevents that behavior.
+ * * MKDIR  - Make the repo_path (and workdir_path) as needed.  Init is
+ *        always willing to create the ".git" directory even without this
+ *        flag.  This flag tells init to create the trailing component of
+ *        the repo and workdir paths as needed.
+ * * MKPATH - Recursively make all components of the repo and workdir
+ *        paths as necessary.
+ * * EXTERNAL_TEMPLATE - libgit2 normally uses internal templates to
+ *        initialize a new repo.  This flags enables external templates,
+ *        looking the "template_path" from the options if set, or the
+ *        `init.templatedir` global config if not, or falling back on
+ *        "/usr/share/git-core/templates" if it exists.
+ * * GIT_REPOSITORY_INIT_RELATIVE_GITLINK - If an alternate workdir is
+ *        specified, use relative paths for the gitdir and core.worktree.
+ */
+typedef enum {
+	GIT_REPOSITORY_INIT_BARE              = (1u << 0),
+	GIT_REPOSITORY_INIT_NO_REINIT         = (1u << 1),
+	GIT_REPOSITORY_INIT_NO_DOTGIT_DIR     = (1u << 2),
+	GIT_REPOSITORY_INIT_MKDIR             = (1u << 3),
+	GIT_REPOSITORY_INIT_MKPATH            = (1u << 4),
+	GIT_REPOSITORY_INIT_EXTERNAL_TEMPLATE = (1u << 5),
+	GIT_REPOSITORY_INIT_RELATIVE_GITLINK  = (1u << 6),
+} git_repository_init_flag_t;
+
+/**
+ * Mode options for `git_repository_init_ext`.
+ *
+ * Set the mode field of the `git_repository_init_options` structure
+ * either to the custom mode that you would like, or to one of the
+ * following modes:
+ *
+ * * SHARED_UMASK - Use permissions configured by umask - the default.
+ * * SHARED_GROUP - Use "--shared=group" behavior, chmod'ing the new repo
+ *        to be group writable and "g+sx" for sticky group assignment.
+ * * SHARED_ALL - Use "--shared=all" behavior, adding world readability.
+ * * Anything else - Set to custom value.
+ */
+typedef enum {
+	GIT_REPOSITORY_INIT_SHARED_UMASK = 0,
+	GIT_REPOSITORY_INIT_SHARED_GROUP = 0002775,
+	GIT_REPOSITORY_INIT_SHARED_ALL   = 0002777,
+} git_repository_init_mode_t;
+
+/**
+ * Extended options structure for `git_repository_init_ext`.
+ *
+ * This contains extra options for `git_repository_init_ext` that enable
+ * additional initialization features.  The fields are:
+ *
+ * * flags - Combination of GIT_REPOSITORY_INIT flags above.
+ * * mode  - Set to one of the standard GIT_REPOSITORY_INIT_SHARED_...
+ *        constants above, or to a custom value that you would like.
+ * * workdir_path - The path to the working dir or NULL for default (i.e.
+ *        repo_path parent on non-bare repos).  IF THIS IS RELATIVE PATH,
+ *        IT WILL BE EVALUATED RELATIVE TO THE REPO_PATH.  If this is not
+ *        the "natural" working directory, a .git gitlink file will be
+ *        created here linking to the repo_path.
+ * * description - If set, this will be used to initialize the "description"
+ *        file in the repository, instead of using the template content.
+ * * template_path - When GIT_REPOSITORY_INIT_EXTERNAL_TEMPLATE is set,
+ *        this contains the path to use for the template directory.  If
+ *        this is NULL, the config or default directory options will be
+ *        used instead.
+ * * initial_head - The name of the head to point HEAD at.  If NULL, then
+ *        this will be treated as "master" and the HEAD ref will be set
+ *        to "refs/heads/master".  If this begins with "refs/" it will be
+ *        used verbatim; otherwise "refs/heads/" will be prefixed.
+ * * origin_url - If this is non-NULL, then after the rest of the
+ *        repository initialization is completed, an "origin" remote
+ *        will be added pointing to this URL.
+ */
+typedef struct {
+	unsigned int version;
+	uint32_t    flags;
+	uint32_t    mode;
+	const char *workdir_path;
+	const char *description;
+	const char *template_path;
+	const char *initial_head;
+	const char *origin_url;
+} git_repository_init_options;
+
+#define GIT_REPOSITORY_INIT_OPTIONS_VERSION 1
+#define GIT_REPOSITORY_INIT_OPTIONS_INIT {GIT_REPOSITORY_INIT_OPTIONS_VERSION}
+
+/**
+ * Initializes a `git_repository_init_options` with default values. Equivalent
+ * to creating an instance with GIT_REPOSITORY_INIT_OPTIONS_INIT.
+ *
+ * @param opts the `git_repository_init_options` struct to initialize
+ * @param version Version of struct; pass `GIT_REPOSITORY_INIT_OPTIONS_VERSION`
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_repository_init_init_options(
+	git_repository_init_options *opts,
+	unsigned int version);
+
+/**
+ * Create a new Git repository in the given folder with extended controls.
+ *
+ * This will initialize a new git repository (creating the repo_path
+ * if requested by flags) and working directory as needed.  It will
+ * auto-detect the case sensitivity of the file system and if the
+ * file system supports file mode bits correctly.
+ *
+ * @param out Pointer to the repo which will be created or reinitialized.
+ * @param repo_path The path to the repository.
+ * @param opts Pointer to git_repository_init_options struct.
+ * @return 0 or an error code on failure.
+ */
+GIT_EXTERN(int) git_repository_init_ext(
+	git_repository **out,
+	const char *repo_path,
+	git_repository_init_options *opts);
+
+/**
+ * Retrieve and resolve the reference pointed at by HEAD.
+ *
+ * The returned `git_reference` will be owned by caller and
+ * `git_reference_free()` must be called when done with it to release the
+ * allocated memory and prevent a leak.
+ *
+ * @param out pointer to the reference which will be retrieved
+ * @param repo a repository object
+ *
+ * @return 0 on success, GIT_EUNBORNBRANCH when HEAD points to a non existing
+ * branch, GIT_ENOTFOUND when HEAD is missing; an error code otherwise
+ */
+GIT_EXTERN(int) git_repository_head(git_reference **out, git_repository *repo);
+
+/**
+ * Retrieve the referenced HEAD for the worktree
+ *
+ * @param out pointer to the reference which will be retrieved
+ * @param repo a repository object
+ * @param name name of the worktree to retrieve HEAD for
+ * @return 0 when successful, error-code otherwise
+ */
+GIT_EXTERN(int) git_repository_head_for_worktree(git_reference **out, git_repository *repo,
+	const char *name);
+
+/**
+ * Check if a repository's HEAD is detached
+ *
+ * A repository's HEAD is detached when it points directly to a commit
+ * instead of a branch.
+ *
+ * @param repo Repo to test
+ * @return 1 if HEAD is detached, 0 if it's not; error code if there
+ * was an error.
+ */
+GIT_EXTERN(int) git_repository_head_detached(git_repository *repo);
+
+/*
+ * Check if a worktree's HEAD is detached
+ *
+ * A worktree's HEAD is detached when it points directly to a
+ * commit instead of a branch.
+ *
+ * @param repo a repository object
+ * @param name name of the worktree to retrieve HEAD for
+ * @return 1 if HEAD is detached, 0 if its not; error code if
+ *  there was an error
+ */
+GIT_EXTERN(int) git_repository_head_detached_for_worktree(git_repository *repo,
+	const char *name);
+
+/**
+ * Check if the current branch is unborn
+ *
+ * An unborn branch is one named from HEAD but which doesn't exist in
+ * the refs namespace, because it doesn't have any commit to point to.
+ *
+ * @param repo Repo to test
+ * @return 1 if the current branch is unborn, 0 if it's not; error
+ * code if there was an error
+ */
+GIT_EXTERN(int) git_repository_head_unborn(git_repository *repo);
+
+/**
+ * Check if a repository is empty
+ *
+ * An empty repository has just been initialized and contains no references
+ * apart from HEAD, which must be pointing to the unborn master branch.
+ *
+ * @param repo Repo to test
+ * @return 1 if the repository is empty, 0 if it isn't, error code
+ * if the repository is corrupted
+ */
+GIT_EXTERN(int) git_repository_is_empty(git_repository *repo);
+
+/**
+ * List of items which belong to the git repository layout
+ */
+typedef enum {
+	GIT_REPOSITORY_ITEM_GITDIR,
+	GIT_REPOSITORY_ITEM_WORKDIR,
+	GIT_REPOSITORY_ITEM_COMMONDIR,
+	GIT_REPOSITORY_ITEM_INDEX,
+	GIT_REPOSITORY_ITEM_OBJECTS,
+	GIT_REPOSITORY_ITEM_REFS,
+	GIT_REPOSITORY_ITEM_PACKED_REFS,
+	GIT_REPOSITORY_ITEM_REMOTES,
+	GIT_REPOSITORY_ITEM_CONFIG,
+	GIT_REPOSITORY_ITEM_INFO,
+	GIT_REPOSITORY_ITEM_HOOKS,
+	GIT_REPOSITORY_ITEM_LOGS,
+	GIT_REPOSITORY_ITEM_MODULES,
+	GIT_REPOSITORY_ITEM_WORKTREES
+} git_repository_item_t;
+
+/**
+ * Get the location of a specific repository file or directory
+ *
+ * This function will retrieve the path of a specific repository
+ * item. It will thereby honor things like the repository's
+ * common directory, gitdir, etc. In case a file path cannot
+ * exist for a given item (e.g. the working directory of a bare
+ * repository), GIT_ENOTFOUND is returned.
+ *
+ * @param out Buffer to store the path at
+ * @param repo Repository to get path for
+ * @param item The repository item for which to retrieve the path
+ * @return 0, GIT_ENOTFOUND if the path cannot exist or an error code
+ */
+GIT_EXTERN(int) git_repository_item_path(git_buf *out, const git_repository *repo, git_repository_item_t item);
+
+/**
+ * Get the path of this repository
+ *
+ * This is the path of the `.git` folder for normal repositories,
+ * or of the repository itself for bare repositories.
+ *
+ * @param repo A repository object
+ * @return the path to the repository
+ */
+GIT_EXTERN(const char *) git_repository_path(const git_repository *repo);
+
+/**
+ * Get the path of the working directory for this repository
+ *
+ * If the repository is bare, this function will always return
+ * NULL.
+ *
+ * @param repo A repository object
+ * @return the path to the working dir, if it exists
+ */
+GIT_EXTERN(const char *) git_repository_workdir(const git_repository *repo);
+
+/**
+ * Get the path of the shared common directory for this repository
+ *
+ * If the repository is bare is not a worktree, the git directory
+ * path is returned.
+ *
+ * @param repo A repository object
+ * @return the path to the common dir
+ */
+GIT_EXTERN(const char *) git_repository_commondir(const git_repository *repo);
+
+/**
+ * Set the path to the working directory for this repository
+ *
+ * The working directory doesn't need to be the same one
+ * that contains the `.git` folder for this repository.
+ *
+ * If this repository is bare, setting its working directory
+ * will turn it into a normal repository, capable of performing
+ * all the common workdir operations (checkout, status, index
+ * manipulation, etc).
+ *
+ * @param repo A repository object
+ * @param workdir The path to a working directory
+ * @param update_gitlink Create/update gitlink in workdir and set config
+ *        "core.worktree" (if workdir is not the parent of the .git directory)
+ * @return 0, or an error code
+ */
+GIT_EXTERN(int) git_repository_set_workdir(
+	git_repository *repo, const char *workdir, int update_gitlink);
+
+/**
+ * Check if a repository is bare
+ *
+ * @param repo Repo to test
+ * @return 1 if the repository is bare, 0 otherwise.
+ */
+GIT_EXTERN(int) git_repository_is_bare(const git_repository *repo);
+
+/**
+ * Check if a repository is a linked work tree
+ *
+ * @param repo Repo to test
+ * @return 1 if the repository is a linked work tree, 0 otherwise.
+ */
+GIT_EXTERN(int) git_repository_is_worktree(const git_repository *repo);
+
+/**
+ * Get the configuration file for this repository.
+ *
+ * If a configuration file has not been set, the default
+ * config set for the repository will be returned, including
+ * global and system configurations (if they are available).
+ *
+ * The configuration file must be freed once it's no longer
+ * being used by the user.
+ *
+ * @param out Pointer to store the loaded configuration
+ * @param repo A repository object
+ * @return 0, or an error code
+ */
+GIT_EXTERN(int) git_repository_config(git_config **out, git_repository *repo);
+
+/**
+ * Get a snapshot of the repository's configuration
+ *
+ * Convenience function to take a snapshot from the repository's
+ * configuration.  The contents of this snapshot will not change,
+ * even if the underlying config files are modified.
+ *
+ * The configuration file must be freed once it's no longer
+ * being used by the user.
+ *
+ * @param out Pointer to store the loaded configuration
+ * @param repo the repository
+ * @return 0, or an error code
+ */
+GIT_EXTERN(int) git_repository_config_snapshot(git_config **out, git_repository *repo);
+
+/**
+ * Get the Object Database for this repository.
+ *
+ * If a custom ODB has not been set, the default
+ * database for the repository will be returned (the one
+ * located in `.git/objects`).
+ *
+ * The ODB must be freed once it's no longer being used by
+ * the user.
+ *
+ * @param out Pointer to store the loaded ODB
+ * @param repo A repository object
+ * @return 0, or an error code
+ */
+GIT_EXTERN(int) git_repository_odb(git_odb **out, git_repository *repo);
+
+/**
+ * Get the Reference Database Backend for this repository.
+ *
+ * If a custom refsdb has not been set, the default database for
+ * the repository will be returned (the one that manipulates loose
+ * and packed references in the `.git` directory).
+ *
+ * The refdb must be freed once it's no longer being used by
+ * the user.
+ *
+ * @param out Pointer to store the loaded refdb
+ * @param repo A repository object
+ * @return 0, or an error code
+ */
+GIT_EXTERN(int) git_repository_refdb(git_refdb **out, git_repository *repo);
+
+/**
+ * Get the Index file for this repository.
+ *
+ * If a custom index has not been set, the default
+ * index for the repository will be returned (the one
+ * located in `.git/index`).
+ *
+ * The index must be freed once it's no longer being used by
+ * the user.
+ *
+ * @param out Pointer to store the loaded index
+ * @param repo A repository object
+ * @return 0, or an error code
+ */
+GIT_EXTERN(int) git_repository_index(git_index **out, git_repository *repo);
+
+/**
+ * Retrieve git's prepared message
+ *
+ * Operations such as git revert/cherry-pick/merge with the -n option
+ * stop just short of creating a commit with the changes and save
+ * their prepared message in .git/MERGE_MSG so the next git-commit
+ * execution can present it to the user for them to amend if they
+ * wish.
+ *
+ * Use this function to get the contents of this file. Don't forget to
+ * remove the file after you create the commit.
+ *
+ * @param out git_buf to write data into
+ * @param repo Repository to read prepared message from
+ * @return 0, GIT_ENOTFOUND if no message exists or an error code
+ */
+GIT_EXTERN(int) git_repository_message(git_buf *out, git_repository *repo);
+
+/**
+ * Remove git's prepared message.
+ *
+ * Remove the message that `git_repository_message` retrieves.
+ */
+GIT_EXTERN(int) git_repository_message_remove(git_repository *repo);
+
+/**
+ * Remove all the metadata associated with an ongoing command like merge,
+ * revert, cherry-pick, etc.  For example: MERGE_HEAD, MERGE_MSG, etc.
+ *
+ * @param repo A repository object
+ * @return 0 on success, or error
+ */
+GIT_EXTERN(int) git_repository_state_cleanup(git_repository *repo);
+
+typedef int (*git_repository_fetchhead_foreach_cb)(const char *ref_name,
+	const char *remote_url,
+	const git_oid *oid,
+	unsigned int is_merge,
+	void *payload);
+
+/**
+ * Invoke 'callback' for each entry in the given FETCH_HEAD file.
+ *
+ * Return a non-zero value from the callback to stop the loop.
+ *
+ * @param repo A repository object
+ * @param callback Callback function
+ * @param payload Pointer to callback data (optional)
+ * @return 0 on success, non-zero callback return value, GIT_ENOTFOUND if
+ *         there is no FETCH_HEAD file, or other error code.
+ */
+GIT_EXTERN(int) git_repository_fetchhead_foreach(
+	git_repository *repo,
+	git_repository_fetchhead_foreach_cb callback,
+	void *payload);
+
+typedef int (*git_repository_mergehead_foreach_cb)(const git_oid *oid,
+	void *payload);
+
+/**
+ * If a merge is in progress, invoke 'callback' for each commit ID in the
+ * MERGE_HEAD file.
+ *
+ * Return a non-zero value from the callback to stop the loop.
+ *
+ * @param repo A repository object
+ * @param callback Callback function
+ * @param payload Pointer to callback data (optional)
+ * @return 0 on success, non-zero callback return value, GIT_ENOTFOUND if
+ *         there is no MERGE_HEAD file, or other error code.
+ */
+GIT_EXTERN(int) git_repository_mergehead_foreach(
+	git_repository *repo,
+	git_repository_mergehead_foreach_cb callback,
+	void *payload);
+
+/**
+ * Calculate hash of file using repository filtering rules.
+ *
+ * If you simply want to calculate the hash of a file on disk with no filters,
+ * you can just use the `git_odb_hashfile()` API.  However, if you want to
+ * hash a file in the repository and you want to apply filtering rules (e.g.
+ * crlf filters) before generating the SHA, then use this function.
+ *
+ * Note: if the repository has `core.safecrlf` set to fail and the
+ * filtering triggers that failure, then this function will return an
+ * error and not calculate the hash of the file.
+ *
+ * @param out Output value of calculated SHA
+ * @param repo Repository pointer
+ * @param path Path to file on disk whose contents should be hashed. If the
+ *             repository is not NULL, this can be a relative path.
+ * @param type The object type to hash as (e.g. GIT_OBJ_BLOB)
+ * @param as_path The path to use to look up filtering rules. If this is
+ *             NULL, then the `path` parameter will be used instead. If
+ *             this is passed as the empty string, then no filters will be
+ *             applied when calculating the hash.
+ * @return 0 on success, or an error code
+ */
+GIT_EXTERN(int) git_repository_hashfile(
+	git_oid *out,
+	git_repository *repo,
+	const char *path,
+	git_otype type,
+	const char *as_path);
+
+/**
+ * Make the repository HEAD point to the specified reference.
+ *
+ * If the provided reference points to a Tree or a Blob, the HEAD is
+ * unaltered and -1 is returned.
+ *
+ * If the provided reference points to a branch, the HEAD will point
+ * to that branch, staying attached, or become attached if it isn't yet.
+ * If the branch doesn't exist yet, no error will be return. The HEAD
+ * will then be attached to an unborn branch.
+ *
+ * Otherwise, the HEAD will be detached and will directly point to
+ * the Commit.
+ *
+ * @param repo Repository pointer
+ * @param refname Canonical name of the reference the HEAD should point at
+ * @return 0 on success, or an error code
+ */
+GIT_EXTERN(int) git_repository_set_head(
+	git_repository* repo,
+	const char* refname);
+
+/**
+ * Make the repository HEAD directly point to the Commit.
+ *
+ * If the provided committish cannot be found in the repository, the HEAD
+ * is unaltered and GIT_ENOTFOUND is returned.
+ *
+ * If the provided commitish cannot be peeled into a commit, the HEAD
+ * is unaltered and -1 is returned.
+ *
+ * Otherwise, the HEAD will eventually be detached and will directly point to
+ * the peeled Commit.
+ *
+ * @param repo Repository pointer
+ * @param commitish Object id of the Commit the HEAD should point to
+ * @return 0 on success, or an error code
+ */
+GIT_EXTERN(int) git_repository_set_head_detached(
+	git_repository* repo,
+	const git_oid* commitish);
+
+/**
+ * Make the repository HEAD directly point to the Commit.
+ *
+ * This behaves like `git_repository_set_head_detached()` but takes an
+ * annotated commit, which lets you specify which extended sha syntax
+ * string was specified by a user, allowing for more exact reflog
+ * messages.
+ *
+ * See the documentation for `git_repository_set_head_detached()`.
+ *
+ * @see git_repository_set_head_detached
+ */
+GIT_EXTERN(int) git_repository_set_head_detached_from_annotated(
+	git_repository *repo,
+	const git_annotated_commit *commitish);
+
+/**
+ * Detach the HEAD.
+ *
+ * If the HEAD is already detached and points to a Commit, 0 is returned.
+ *
+ * If the HEAD is already detached and points to a Tag, the HEAD is
+ * updated into making it point to the peeled Commit, and 0 is returned.
+ *
+ * If the HEAD is already detached and points to a non commitish, the HEAD is
+ * unaltered, and -1 is returned.
+ *
+ * Otherwise, the HEAD will be detached and point to the peeled Commit.
+ *
+ * @param repo Repository pointer
+ * @return 0 on success, GIT_EUNBORNBRANCH when HEAD points to a non existing
+ * branch or an error code
+ */
+GIT_EXTERN(int) git_repository_detach_head(
+	git_repository* repo);
+
+/**
+ * Repository state
+ *
+ * These values represent possible states for the repository to be in,
+ * based on the current operation which is ongoing.
+ */
+typedef enum {
+	GIT_REPOSITORY_STATE_NONE,
+	GIT_REPOSITORY_STATE_MERGE,
+	GIT_REPOSITORY_STATE_REVERT,
+	GIT_REPOSITORY_STATE_REVERT_SEQUENCE,
+	GIT_REPOSITORY_STATE_CHERRYPICK,
+	GIT_REPOSITORY_STATE_CHERRYPICK_SEQUENCE,
+	GIT_REPOSITORY_STATE_BISECT,
+	GIT_REPOSITORY_STATE_REBASE,
+	GIT_REPOSITORY_STATE_REBASE_INTERACTIVE,
+	GIT_REPOSITORY_STATE_REBASE_MERGE,
+	GIT_REPOSITORY_STATE_APPLY_MAILBOX,
+	GIT_REPOSITORY_STATE_APPLY_MAILBOX_OR_REBASE,
+} git_repository_state_t;
+
+/**
+ * Determines the status of a git repository - ie, whether an operation
+ * (merge, cherry-pick, etc) is in progress.
+ *
+ * @param repo Repository pointer
+ * @return The state of the repository
+ */
+GIT_EXTERN(int) git_repository_state(git_repository *repo);
+
+/**
+ * Sets the active namespace for this Git Repository
+ *
+ * This namespace affects all reference operations for the repo.
+ * See `man gitnamespaces`
+ *
+ * @param repo The repo
+ * @param nmspace The namespace. This should not include the refs
+ *	folder, e.g. to namespace all references under `refs/namespaces/foo/`,
+ *	use `foo` as the namespace.
+ *	@return 0 on success, -1 on error
+ */
+GIT_EXTERN(int) git_repository_set_namespace(git_repository *repo, const char *nmspace);
+
+/**
+ * Get the currently active namespace for this repository
+ *
+ * @param repo The repo
+ * @return the active namespace, or NULL if there isn't one
+ */
+GIT_EXTERN(const char *) git_repository_get_namespace(git_repository *repo);
+
+
+/**
+ * Determine if the repository was a shallow clone
+ *
+ * @param repo The repository
+ * @return 1 if shallow, zero if not
+ */
+GIT_EXTERN(int) git_repository_is_shallow(git_repository *repo);
+
+/**
+ * Retrieve the configured identity to use for reflogs
+ *
+ * The memory is owned by the repository and must not be freed by the
+ * user.
+ *
+ * @param name where to store the pointer to the name
+ * @param email where to store the pointer to the email
+ * @param repo the repository
+ */
+GIT_EXTERN(int) git_repository_ident(const char **name, const char **email, const git_repository *repo);
+
+/**
+ * Set the identity to be used for writing reflogs
+ *
+ * If both are set, this name and email will be used to write to the
+ * reflog. Pass NULL to unset. When unset, the identity will be taken
+ * from the repository's configuration.
+ *
+ * @param repo the repository to configure
+ * @param name the name to use for the reflog entries
+ * @param email the email to use for the reflog entries
+ */
+GIT_EXTERN(int) git_repository_set_ident(git_repository *repo, const char *name, const char *email);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/reset.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/reset.h b/vendor/libgit2-sys/libgit2/include/git2/reset.h
new file mode 100644
index 0000000..be25414
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/reset.h
@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_reset_h__
+#define INCLUDE_git_reset_h__
+
+#include "common.h"
+#include "types.h"
+#include "strarray.h"
+#include "checkout.h"
+
+/**
+ * @file git2/reset.h
+ * @brief Git reset management routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Kinds of reset operation
+ */
+typedef enum {
+	GIT_RESET_SOFT  = 1, /**< Move the head to the given commit */
+	GIT_RESET_MIXED = 2, /**< SOFT plus reset index to the commit */
+	GIT_RESET_HARD  = 3, /**< MIXED plus changes in working tree discarded */
+} git_reset_t;
+
+/**
+ * Sets the current head to the specified commit oid and optionally
+ * resets the index and working tree to match.
+ *
+ * SOFT reset means the Head will be moved to the commit.
+ *
+ * MIXED reset will trigger a SOFT reset, plus the index will be replaced
+ * with the content of the commit tree.
+ *
+ * HARD reset will trigger a MIXED reset and the working directory will be
+ * replaced with the content of the index.  (Untracked and ignored files
+ * will be left alone, however.)
+ *
+ * TODO: Implement remaining kinds of resets.
+ *
+ * @param repo Repository where to perform the reset operation.
+ *
+ * @param target Committish to which the Head should be moved to. This object
+ * must belong to the given `repo` and can either be a git_commit or a
+ * git_tag. When a git_tag is being passed, it should be dereferencable
+ * to a git_commit which oid will be used as the target of the branch.
+ *
+ * @param reset_type Kind of reset operation to perform.
+ *
+ * @param checkout_opts Optional checkout options to be used for a HARD reset.
+ * The checkout_strategy field will be overridden (based on reset_type).
+ * This parameter can be used to propagate notify and progress callbacks.
+ *
+ * @return 0 on success or an error code
+ */
+GIT_EXTERN(int) git_reset(
+	git_repository *repo,
+	const git_object *target,
+	git_reset_t reset_type,
+	const git_checkout_options *checkout_opts);
+
+/**
+ * Sets the current head to the specified commit oid and optionally
+ * resets the index and working tree to match.
+ *
+ * This behaves like `git_reset()` but takes an annotated commit,
+ * which lets you specify which extended sha syntax string was
+ * specified by a user, allowing for more exact reflog messages.
+ *
+ * See the documentation for `git_reset()`.
+ *
+ * @see git_reset
+ */
+GIT_EXTERN(int) git_reset_from_annotated(
+	git_repository *repo,
+	const git_annotated_commit *commit,
+	git_reset_t reset_type,
+	const git_checkout_options *checkout_opts);
+
+/**
+ * Updates some entries in the index from the target commit tree.
+ *
+ * The scope of the updated entries is determined by the paths
+ * being passed in the `pathspec` parameters.
+ *
+ * Passing a NULL `target` will result in removing
+ * entries in the index matching the provided pathspecs.
+ *
+ * @param repo Repository where to perform the reset operation.
+ *
+ * @param target The committish which content will be used to reset the content
+ * of the index.
+ *
+ * @param pathspecs List of pathspecs to operate on.
+ *
+ * @return 0 on success or an error code < 0
+ */
+GIT_EXTERN(int) git_reset_default(
+	git_repository *repo,
+	const git_object *target,
+	const git_strarray* pathspecs);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/revert.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/revert.h b/vendor/libgit2-sys/libgit2/include/git2/revert.h
new file mode 100644
index 0000000..82dbadc
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/revert.h
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_revert_h__
+#define INCLUDE_git_revert_h__
+
+#include "common.h"
+#include "types.h"
+#include "merge.h"
+
+/**
+ * @file git2/revert.h
+ * @brief Git revert routines
+ * @defgroup git_revert Git revert routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Options for revert
+ */
+typedef struct {
+	unsigned int version;
+
+	/** For merge commits, the "mainline" is treated as the parent. */
+	unsigned int mainline;
+
+	git_merge_options merge_opts; /**< Options for the merging */
+	git_checkout_options checkout_opts; /**< Options for the checkout */
+} git_revert_options;
+
+#define GIT_REVERT_OPTIONS_VERSION 1
+#define GIT_REVERT_OPTIONS_INIT {GIT_REVERT_OPTIONS_VERSION, 0, GIT_MERGE_OPTIONS_INIT, GIT_CHECKOUT_OPTIONS_INIT}
+
+/**
+ * Initializes a `git_revert_options` with default values. Equivalent to
+ * creating an instance with GIT_REVERT_OPTIONS_INIT.
+ *
+ * @param opts the `git_revert_options` struct to initialize
+ * @param version Version of struct; pass `GIT_REVERT_OPTIONS_VERSION`
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_revert_init_options(
+	git_revert_options *opts,
+	unsigned int version);
+
+/**
+ * Reverts the given commit against the given "our" commit, producing an
+ * index that reflects the result of the revert.
+ *
+ * The returned index must be freed explicitly with `git_index_free`.
+ *
+ * @param out pointer to store the index result in
+ * @param repo the repository that contains the given commits
+ * @param revert_commit the commit to revert
+ * @param our_commit the commit to revert against (eg, HEAD)
+ * @param mainline the parent of the revert commit, if it is a merge
+ * @param merge_options the merge options (or null for defaults)
+ * @return zero on success, -1 on failure.
+ */
+GIT_EXTERN(int) git_revert_commit(
+	git_index **out,
+	git_repository *repo,
+	git_commit *revert_commit,
+	git_commit *our_commit,
+	unsigned int mainline,
+	const git_merge_options *merge_options);
+
+/**
+ * Reverts the given commit, producing changes in the index and working directory.
+ *
+ * @param repo the repository to revert
+ * @param commit the commit to revert
+ * @param given_opts the revert options (or null for defaults)
+ * @return zero on success, -1 on failure.
+ */
+GIT_EXTERN(int) git_revert(
+	git_repository *repo,
+	git_commit *commit,
+	const git_revert_options *given_opts);
+
+/** @} */
+GIT_END_DECL
+#endif
+

vendor/libgit2-sys/libgit2/include/git2/revparse.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/revparse.h b/vendor/libgit2-sys/libgit2/include/git2/revparse.h
new file mode 100644
index 0000000..d170e16
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/revparse.h
@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_revparse_h__
+#define INCLUDE_git_revparse_h__
+
+#include "common.h"
+#include "types.h"
+
+/**
+ * @file git2/revparse.h
+ * @brief Git revision parsing routines
+ * @defgroup git_revparse Git revision parsing routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Find a single object, as specified by a revision string.
+ *
+ * See `man gitrevisions`, or
+ * http://git-scm.com/docs/git-rev-parse.html#_specifying_revisions for
+ * information on the syntax accepted.
+ *
+ * The returned object should be released with `git_object_free` when no
+ * longer needed.
+ *
+ * @param out pointer to output object
+ * @param repo the repository to search in
+ * @param spec the textual specification for an object
+ * @return 0 on success, GIT_ENOTFOUND, GIT_EAMBIGUOUS, GIT_EINVALIDSPEC or an error code
+ */
+GIT_EXTERN(int) git_revparse_single(
+	git_object **out, git_repository *repo, const char *spec);
+
+/**
+ * Find a single object and intermediate reference by a revision string.
+ *
+ * See `man gitrevisions`, or
+ * http://git-scm.com/docs/git-rev-parse.html#_specifying_revisions for
+ * information on the syntax accepted.
+ *
+ * In some cases (`@{<-n>}` or `<branchname>@{upstream}`), the expression may
+ * point to an intermediate reference. When such expressions are being passed
+ * in, `reference_out` will be valued as well.
+ *
+ * The returned object should be released with `git_object_free` and the
+ * returned reference with `git_reference_free` when no longer needed.
+ *
+ * @param object_out pointer to output object
+ * @param reference_out pointer to output reference or NULL
+ * @param repo the repository to search in
+ * @param spec the textual specification for an object
+ * @return 0 on success, GIT_ENOTFOUND, GIT_EAMBIGUOUS, GIT_EINVALIDSPEC
+ * or an error code
+ */
+GIT_EXTERN(int) git_revparse_ext(
+	git_object **object_out,
+	git_reference **reference_out,
+	git_repository *repo,
+	const char *spec);
+
+/**
+ * Revparse flags.  These indicate the intended behavior of the spec passed to
+ * git_revparse.
+ */
+typedef enum {
+	/** The spec targeted a single object. */
+	GIT_REVPARSE_SINGLE         = 1 << 0,
+	/** The spec targeted a range of commits. */
+	GIT_REVPARSE_RANGE          = 1 << 1,
+	/** The spec used the '...' operator, which invokes special semantics. */
+	GIT_REVPARSE_MERGE_BASE     = 1 << 2,
+} git_revparse_mode_t;
+
+/**
+ * Git Revision Spec: output of a `git_revparse` operation
+ */
+typedef struct {
+	/** The left element of the revspec; must be freed by the user */
+	git_object *from;
+	/** The right element of the revspec; must be freed by the user */
+	git_object *to;
+	/** The intent of the revspec (i.e. `git_revparse_mode_t` flags) */
+	unsigned int flags;
+} git_revspec;
+
+/**
+ * Parse a revision string for `from`, `to`, and intent.
+ *
+ * See `man gitrevisions` or
+ * http://git-scm.com/docs/git-rev-parse.html#_specifying_revisions for
+ * information on the syntax accepted.
+ *
+ * @param revspec Pointer to an user-allocated git_revspec struct where
+ *	              the result of the rev-parse will be stored
+ * @param repo the repository to search in
+ * @param spec the rev-parse spec to parse
+ * @return 0 on success, GIT_INVALIDSPEC, GIT_ENOTFOUND, GIT_EAMBIGUOUS or an error code
+ */
+GIT_EXTERN(int) git_revparse(
+	git_revspec *revspec,
+	git_repository *repo,
+	const char *spec);
+
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/revwalk.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/revwalk.h b/vendor/libgit2-sys/libgit2/include/git2/revwalk.h
new file mode 100644
index 0000000..d9376ce
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/revwalk.h
@@ -0,0 +1,295 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_revwalk_h__
+#define INCLUDE_git_revwalk_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+
+/**
+ * @file git2/revwalk.h
+ * @brief Git revision traversal routines
+ * @defgroup git_revwalk Git revision traversal routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Flags to specify the sorting which a revwalk should perform.
+ */
+typedef enum {
+	/**
+	 * Sort the output with the same default time-order method from git.
+	 * This is the default sorting for new walkers.
+	 */
+	GIT_SORT_NONE = 0,
+
+	/**
+	 * Sort the repository contents in topological order (parents before
+	 * children); this sorting mode can be combined with time sorting to
+	 * produce git's "time-order".
+	 */
+	GIT_SORT_TOPOLOGICAL = 1 << 0,
+
+	/**
+	 * Sort the repository contents by commit time;
+	 * this sorting mode can be combined with
+	 * topological sorting.
+	 */
+	GIT_SORT_TIME = 1 << 1,
+
+	/**
+	 * Iterate through the repository contents in reverse
+	 * order; this sorting mode can be combined with
+	 * any of the above.
+	 */
+	GIT_SORT_REVERSE = 1 << 2,
+} git_sort_t;
+
+/**
+ * Allocate a new revision walker to iterate through a repo.
+ *
+ * This revision walker uses a custom memory pool and an internal
+ * commit cache, so it is relatively expensive to allocate.
+ *
+ * For maximum performance, this revision walker should be
+ * reused for different walks.
+ *
+ * This revision walker is *not* thread safe: it may only be
+ * used to walk a repository on a single thread; however,
+ * it is possible to have several revision walkers in
+ * several different threads walking the same repository.
+ *
+ * @param out pointer to the new revision walker
+ * @param repo the repo to walk through
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_revwalk_new(git_revwalk **out, git_repository *repo);
+
+/**
+ * Reset the revision walker for reuse.
+ *
+ * This will clear all the pushed and hidden commits, and
+ * leave the walker in a blank state (just like at
+ * creation) ready to receive new commit pushes and
+ * start a new walk.
+ *
+ * The revision walk is automatically reset when a walk
+ * is over.
+ *
+ * @param walker handle to reset.
+ */
+GIT_EXTERN(void) git_revwalk_reset(git_revwalk *walker);
+
+/**
+ * Add a new root for the traversal
+ *
+ * The pushed commit will be marked as one of the roots from which to
+ * start the walk. This commit may not be walked if it or a child is
+ * hidden.
+ *
+ * At least one commit must be pushed onto the walker before a walk
+ * can be started.
+ *
+ * The given id must belong to a committish on the walked
+ * repository.
+ *
+ * @param walk the walker being used for the traversal.
+ * @param id the oid of the commit to start from.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_revwalk_push(git_revwalk *walk, const git_oid *id);
+
+/**
+ * Push matching references
+ *
+ * The OIDs pointed to by the references that match the given glob
+ * pattern will be pushed to the revision walker.
+ *
+ * A leading 'refs/' is implied if not present as well as a trailing
+ * '/\*' if the glob lacks '?', '\*' or '['.
+ *
+ * Any references matching this glob which do not point to a
+ * committish will be ignored.
+ *
+ * @param walk the walker being used for the traversal
+ * @param glob the glob pattern references should match
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_revwalk_push_glob(git_revwalk *walk, const char *glob);
+
+/**
+ * Push the repository's HEAD
+ *
+ * @param walk the walker being used for the traversal
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_revwalk_push_head(git_revwalk *walk);
+
+/**
+ * Mark a commit (and its ancestors) uninteresting for the output.
+ *
+ * The given id must belong to a committish on the walked
+ * repository.
+ *
+ * The resolved commit and all its parents will be hidden from the
+ * output on the revision walk.
+ *
+ * @param walk the walker being used for the traversal.
+ * @param commit_id the oid of commit that will be ignored during the traversal
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_revwalk_hide(git_revwalk *walk, const git_oid *commit_id);
+
+/**
+ * Hide matching references.
+ *
+ * The OIDs pointed to by the references that match the given glob
+ * pattern and their ancestors will be hidden from the output on the
+ * revision walk.
+ *
+ * A leading 'refs/' is implied if not present as well as a trailing
+ * '/\*' if the glob lacks '?', '\*' or '['.
+ *
+ * Any references matching this glob which do not point to a
+ * committish will be ignored.
+ *
+ * @param walk the walker being used for the traversal
+ * @param glob the glob pattern references should match
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_revwalk_hide_glob(git_revwalk *walk, const char *glob);
+
+/**
+ * Hide the repository's HEAD
+ *
+ * @param walk the walker being used for the traversal
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_revwalk_hide_head(git_revwalk *walk);
+
+/**
+ * Push the OID pointed to by a reference
+ *
+ * The reference must point to a committish.
+ *
+ * @param walk the walker being used for the traversal
+ * @param refname the reference to push
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_revwalk_push_ref(git_revwalk *walk, const char *refname);
+
+/**
+ * Hide the OID pointed to by a reference
+ *
+ * The reference must point to a committish.
+ *
+ * @param walk the walker being used for the traversal
+ * @param refname the reference to hide
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_revwalk_hide_ref(git_revwalk *walk, const char *refname);
+
+/**
+ * Get the next commit from the revision walk.
+ *
+ * The initial call to this method is *not* blocking when
+ * iterating through a repo with a time-sorting mode.
+ *
+ * Iterating with Topological or inverted modes makes the initial
+ * call blocking to preprocess the commit list, but this block should be
+ * mostly unnoticeable on most repositories (topological preprocessing
+ * times at 0.3s on the git.git repo).
+ *
+ * The revision walker is reset when the walk is over.
+ *
+ * @param out Pointer where to store the oid of the next commit
+ * @param walk the walker to pop the commit from.
+ * @return 0 if the next commit was found;
+ *	GIT_ITEROVER if there are no commits left to iterate
+ */
+GIT_EXTERN(int) git_revwalk_next(git_oid *out, git_revwalk *walk);
+
+/**
+ * Change the sorting mode when iterating through the
+ * repository's contents.
+ *
+ * Changing the sorting mode resets the walker.
+ *
+ * @param walk the walker being used for the traversal.
+ * @param sort_mode combination of GIT_SORT_XXX flags
+ */
+GIT_EXTERN(void) git_revwalk_sorting(git_revwalk *walk, unsigned int sort_mode);
+
+/**
+ * Push and hide the respective endpoints of the given range.
+ *
+ * The range should be of the form
+ *   <commit>..<commit>
+ * where each <commit> is in the form accepted by 'git_revparse_single'.
+ * The left-hand commit will be hidden and the right-hand commit pushed.
+ *
+ * @param walk the walker being used for the traversal
+ * @param range the range
+ * @return 0 or an error code
+ *
+ */
+GIT_EXTERN(int) git_revwalk_push_range(git_revwalk *walk, const char *range);
+
+/**
+ * Simplify the history by first-parent
+ *
+ * No parents other than the first for each commit will be enqueued.
+ */
+GIT_EXTERN(void) git_revwalk_simplify_first_parent(git_revwalk *walk);
+
+
+/**
+ * Free a revision walker previously allocated.
+ *
+ * @param walk traversal handle to close. If NULL nothing occurs.
+ */
+GIT_EXTERN(void) git_revwalk_free(git_revwalk *walk);
+
+/**
+ * Return the repository on which this walker
+ * is operating.
+ *
+ * @param walk the revision walker
+ * @return the repository being walked
+ */
+GIT_EXTERN(git_repository *) git_revwalk_repository(git_revwalk *walk);
+
+/**
+ * This is a callback function that user can provide to hide a
+ * commit and its parents. If the callback function returns non-zero value,
+ * then this commit and its parents will be hidden.
+ *
+ * @param commit_id oid of Commit
+ * @param payload User-specified pointer to data to be passed as data payload
+ */
+typedef int(*git_revwalk_hide_cb)(
+	const git_oid *commit_id,
+	void *payload);
+
+/**
+ * Adds a callback function to hide a commit and its parents
+ *
+ * @param walk the revision walker
+ * @param hide_cb  callback function to hide a commit and its parents
+ * @param payload  data payload to be passed to callback function
+ */
+GIT_EXTERN(int) git_revwalk_add_hide_cb(
+	git_revwalk *walk,
+	git_revwalk_hide_cb hide_cb,
+	void *payload);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/signature.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/signature.h b/vendor/libgit2-sys/libgit2/include/git2/signature.h
new file mode 100644
index 0000000..7a2a023
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/signature.h
@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_signature_h__
+#define INCLUDE_git_signature_h__
+
+#include "common.h"
+#include "types.h"
+
+/**
+ * @file git2/signature.h
+ * @brief Git signature creation
+ * @defgroup git_signature Git signature creation
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Create a new action signature.
+ *
+ * Call `git_signature_free()` to free the data.
+ *
+ * Note: angle brackets ('<' and '>') characters are not allowed
+ * to be used in either the `name` or the `email` parameter.
+ *
+ * @param out new signature, in case of error NULL
+ * @param name name of the person
+ * @param email email of the person
+ * @param time time when the action happened
+ * @param offset timezone offset in minutes for the time
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_signature_new(git_signature **out, const char *name, const char *email, git_time_t time, int offset);
+
+/**
+ * Create a new action signature with a timestamp of 'now'.
+ *
+ * Call `git_signature_free()` to free the data.
+ *
+ * @param out new signature, in case of error NULL
+ * @param name name of the person
+ * @param email email of the person
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_signature_now(git_signature **out, const char *name, const char *email);
+
+/**
+ * Create a new action signature with default user and now timestamp.
+ *
+ * This looks up the user.name and user.email from the configuration and
+ * uses the current time as the timestamp, and creates a new signature
+ * based on that information.  It will return GIT_ENOTFOUND if either the
+ * user.name or user.email are not set.
+ *
+ * @param out new signature
+ * @param repo repository pointer
+ * @return 0 on success, GIT_ENOTFOUND if config is missing, or error code
+ */
+GIT_EXTERN(int) git_signature_default(git_signature **out, git_repository *repo);
+
+/**
+ * Create a new signature by parsing the given buffer, which is
+ * expected to be in the format "Real Name <email> timestamp tzoffset",
+ * where `timestamp` is the number of seconds since the Unix epoch and
+ * `tzoffset` is the timezone offset in `hhmm` format (note the lack
+ * of a colon separator).
+ *
+ * @param out new signature
+ * @param buf signature string
+ * @return 0 on success, or an error code
+ */
+GIT_EXTERN(int) git_signature_from_buffer(git_signature **out, const char *buf);
+
+/**
+ * Create a copy of an existing signature.  All internal strings are also
+ * duplicated.
+ *
+ * Call `git_signature_free()` to free the data.
+ *
+ * @param dest pointer where to store the copy
+ * @param sig signature to duplicate
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_signature_dup(git_signature **dest, const git_signature *sig);
+
+/**
+ * Free an existing signature.
+ *
+ * Because the signature is not an opaque structure, it is legal to free it
+ * manually, but be sure to free the "name" and "email" strings in addition
+ * to the structure itself.
+ *
+ * @param sig signature to free
+ */
+GIT_EXTERN(void) git_signature_free(git_signature *sig);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/stash.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/stash.h b/vendor/libgit2-sys/libgit2/include/git2/stash.h
new file mode 100644
index 0000000..3af9cde
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/stash.h
@@ -0,0 +1,257 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_stash_h__
+#define INCLUDE_git_stash_h__
+
+#include "common.h"
+#include "types.h"
+
+/**
+ * @file git2/stash.h
+ * @brief Git stash management routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Stash flags
+ */
+typedef enum {
+	/**
+	 * No option, default
+	 */
+	GIT_STASH_DEFAULT = 0,
+
+	/**
+	 * All changes already added to the index are left intact in
+	 * the working directory
+	 */
+	GIT_STASH_KEEP_INDEX = (1 << 0),
+
+	/**
+	 * All untracked files are also stashed and then cleaned up
+	 * from the working directory
+	 */
+	GIT_STASH_INCLUDE_UNTRACKED = (1 << 1),
+
+	/**
+	 * All ignored files are also stashed and then cleaned up from
+	 * the working directory
+	 */
+	GIT_STASH_INCLUDE_IGNORED = (1 << 2),
+} git_stash_flags;
+
+/**
+ * Save the local modifications to a new stash.
+ *
+ * @param out Object id of the commit containing the stashed state.
+ * This commit is also the target of the direct reference refs/stash.
+ *
+ * @param repo The owning repository.
+ *
+ * @param stasher The identity of the person performing the stashing.
+ *
+ * @param message Optional description along with the stashed state.
+ *
+ * @param flags Flags to control the stashing process. (see GIT_STASH_* above)
+ *
+ * @return 0 on success, GIT_ENOTFOUND where there's nothing to stash,
+ * or error code.
+ */
+GIT_EXTERN(int) git_stash_save(
+	git_oid *out,
+	git_repository *repo,
+	const git_signature *stasher,
+	const char *message,
+	uint32_t flags);
+
+/** Stash application flags. */
+typedef enum {
+	GIT_STASH_APPLY_DEFAULT = 0,
+
+	/* Try to reinstate not only the working tree's changes,
+	 * but also the index's changes.
+	 */
+	GIT_STASH_APPLY_REINSTATE_INDEX = (1 << 0),
+} git_stash_apply_flags;
+
+typedef enum {
+	GIT_STASH_APPLY_PROGRESS_NONE = 0,
+
+	/** Loading the stashed data from the object database. */
+	GIT_STASH_APPLY_PROGRESS_LOADING_STASH,
+
+	/** The stored index is being analyzed. */
+	GIT_STASH_APPLY_PROGRESS_ANALYZE_INDEX,
+
+	/** The modified files are being analyzed. */
+	GIT_STASH_APPLY_PROGRESS_ANALYZE_MODIFIED,
+
+	/** The untracked and ignored files are being analyzed. */
+	GIT_STASH_APPLY_PROGRESS_ANALYZE_UNTRACKED,
+
+	/** The untracked files are being written to disk. */
+	GIT_STASH_APPLY_PROGRESS_CHECKOUT_UNTRACKED,
+
+	/** The modified files are being written to disk. */
+	GIT_STASH_APPLY_PROGRESS_CHECKOUT_MODIFIED,
+
+	/** The stash was applied successfully. */
+	GIT_STASH_APPLY_PROGRESS_DONE,
+} git_stash_apply_progress_t;
+
+/**
+ * Stash application progress notification function.
+ * Return 0 to continue processing, or a negative value to
+ * abort the stash application.
+ */
+typedef int (*git_stash_apply_progress_cb)(
+	git_stash_apply_progress_t progress,
+	void *payload);
+
+/** Stash application options structure.
+ *
+ * Initialize with the `GIT_STASH_APPLY_OPTIONS_INIT` macro to set
+ * sensible defaults; for example:
+ *
+ *		git_stash_apply_options opts = GIT_STASH_APPLY_OPTIONS_INIT;
+ */
+typedef struct git_stash_apply_options {
+	unsigned int version;
+
+	/** See `git_stash_apply_flags_t`, above. */
+	git_stash_apply_flags flags;
+
+	/** Options to use when writing files to the working directory. */
+	git_checkout_options checkout_options;
+
+	/** Optional callback to notify the consumer of application progress. */
+	git_stash_apply_progress_cb progress_cb;
+	void *progress_payload;
+} git_stash_apply_options;
+
+#define GIT_STASH_APPLY_OPTIONS_VERSION 1
+#define GIT_STASH_APPLY_OPTIONS_INIT { \
+	GIT_STASH_APPLY_OPTIONS_VERSION, \
+	GIT_STASH_APPLY_DEFAULT, \
+	GIT_CHECKOUT_OPTIONS_INIT }
+
+/**
+ * Initializes a `git_stash_apply_options` with default values. Equivalent to
+ * creating an instance with GIT_STASH_APPLY_OPTIONS_INIT.
+ *
+ * @param opts the `git_stash_apply_options` instance to initialize.
+ * @param version the version of the struct; you should pass
+ *        `GIT_STASH_APPLY_OPTIONS_INIT` here.
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_stash_apply_init_options(
+	git_stash_apply_options *opts, unsigned int version);
+
+/**
+ * Apply a single stashed state from the stash list.
+ *
+ * If local changes in the working directory conflict with changes in the
+ * stash then GIT_EMERGECONFLICT will be returned.  In this case, the index
+ * will always remain unmodified and all files in the working directory will
+ * remain unmodified.  However, if you are restoring untracked files or
+ * ignored files and there is a conflict when applying the modified files,
+ * then those files will remain in the working directory.
+ *
+ * If passing the GIT_STASH_APPLY_REINSTATE_INDEX flag and there would be
+ * conflicts when reinstating the index, the function will return
+ * GIT_EMERGECONFLICT and both the working directory and index will be left
+ * unmodified.
+ *
+ * Note that a minimum checkout strategy of `GIT_CHECKOUT_SAFE` is implied.
+ *
+ * @param repo The owning repository.
+ * @param index The position within the stash list. 0 points to the
+ *              most recent stashed state.
+ * @param options Optional options to control how stashes are applied.
+ *
+ * @return 0 on success, GIT_ENOTFOUND if there's no stashed state for the
+ *         given index, GIT_EMERGECONFLICT if changes exist in the working
+ *         directory, or an error code
+ */
+GIT_EXTERN(int) git_stash_apply(
+	git_repository *repo,
+	size_t index,
+	const git_stash_apply_options *options);
+
+/**
+ * This is a callback function you can provide to iterate over all the
+ * stashed states that will be invoked per entry.
+ *
+ * @param index The position within the stash list. 0 points to the
+ *              most recent stashed state.
+ * @param message The stash message.
+ * @param stash_id The commit oid of the stashed state.
+ * @param payload Extra parameter to callback function.
+ * @return 0 to continue iterating or non-zero to stop.
+ */
+typedef int (*git_stash_cb)(
+	size_t index,
+	const char* message,
+	const git_oid *stash_id,
+	void *payload);
+
+/**
+ * Loop over all the stashed states and issue a callback for each one.
+ *
+ * If the callback returns a non-zero value, this will stop looping.
+ *
+ * @param repo Repository where to find the stash.
+ *
+ * @param callback Callback to invoke per found stashed state. The most
+ *                 recent stash state will be enumerated first.
+ *
+ * @param payload Extra parameter to callback function.
+ *
+ * @return 0 on success, non-zero callback return value, or error code.
+ */
+GIT_EXTERN(int) git_stash_foreach(
+	git_repository *repo,
+	git_stash_cb callback,
+	void *payload);
+
+/**
+ * Remove a single stashed state from the stash list.
+ *
+ * @param repo The owning repository.
+ *
+ * @param index The position within the stash list. 0 points to the
+ * most recent stashed state.
+ *
+ * @return 0 on success, GIT_ENOTFOUND if there's no stashed state for the given
+ * index, or error code.
+ */
+GIT_EXTERN(int) git_stash_drop(
+	git_repository *repo,
+	size_t index);
+
+/**
+ * Apply a single stashed state from the stash list and remove it from the list
+ * if successful.
+ *
+ * @param repo The owning repository.
+ * @param index The position within the stash list. 0 points to the
+ *              most recent stashed state.
+ * @param options Optional options to control how stashes are applied.
+ *
+ * @return 0 on success, GIT_ENOTFOUND if there's no stashed state for the given
+ * index, or error code. (see git_stash_apply() above for details)
+*/
+GIT_EXTERN(int) git_stash_pop(
+	git_repository *repo,
+	size_t index,
+	const git_stash_apply_options *options);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/status.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/status.h b/vendor/libgit2-sys/libgit2/include/git2/status.h
new file mode 100644
index 0000000..4b86818
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/status.h
@@ -0,0 +1,374 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_status_h__
+#define INCLUDE_git_status_h__
+
+#include "common.h"
+#include "types.h"
+
+/**
+ * @file git2/status.h
+ * @brief Git file status routines
+ * @defgroup git_status Git file status routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Status flags for a single file.
+ *
+ * A combination of these values will be returned to indicate the status of
+ * a file.  Status compares the working directory, the index, and the
+ * current HEAD of the repository.  The `GIT_STATUS_INDEX` set of flags
+ * represents the status of file in the index relative to the HEAD, and the
+ * `GIT_STATUS_WT` set of flags represent the status of the file in the
+ * working directory relative to the index.
+ */
+typedef enum {
+	GIT_STATUS_CURRENT = 0,
+
+	GIT_STATUS_INDEX_NEW        = (1u << 0),
+	GIT_STATUS_INDEX_MODIFIED   = (1u << 1),
+	GIT_STATUS_INDEX_DELETED    = (1u << 2),
+	GIT_STATUS_INDEX_RENAMED    = (1u << 3),
+	GIT_STATUS_INDEX_TYPECHANGE = (1u << 4),
+
+	GIT_STATUS_WT_NEW           = (1u << 7),
+	GIT_STATUS_WT_MODIFIED      = (1u << 8),
+	GIT_STATUS_WT_DELETED       = (1u << 9),
+	GIT_STATUS_WT_TYPECHANGE    = (1u << 10),
+	GIT_STATUS_WT_RENAMED       = (1u << 11),
+	GIT_STATUS_WT_UNREADABLE    = (1u << 12),
+
+	GIT_STATUS_IGNORED          = (1u << 14),
+	GIT_STATUS_CONFLICTED       = (1u << 15),
+} git_status_t;
+
+/**
+ * Function pointer to receive status on individual files
+ *
+ * `path` is the relative path to the file from the root of the repository.
+ *
+ * `status_flags` is a combination of `git_status_t` values that apply.
+ *
+ * `payload` is the value you passed to the foreach function as payload.
+ */
+typedef int (*git_status_cb)(
+	const char *path, unsigned int status_flags, void *payload);
+
+/**
+ * Select the files on which to report status.
+ *
+ * With `git_status_foreach_ext`, this will control which changes get
+ * callbacks.  With `git_status_list_new`, these will control which
+ * changes are included in the list.
+ *
+ * - GIT_STATUS_SHOW_INDEX_AND_WORKDIR is the default.  This roughly
+ *   matches `git status --porcelain` regarding which files are
+ *   included and in what order.
+ * - GIT_STATUS_SHOW_INDEX_ONLY only gives status based on HEAD to index
+ *   comparison, not looking at working directory changes.
+ * - GIT_STATUS_SHOW_WORKDIR_ONLY only gives status based on index to
+ *   working directory comparison, not comparing the index to the HEAD.
+ */
+typedef enum {
+	GIT_STATUS_SHOW_INDEX_AND_WORKDIR = 0,
+	GIT_STATUS_SHOW_INDEX_ONLY = 1,
+	GIT_STATUS_SHOW_WORKDIR_ONLY = 2,
+} git_status_show_t;
+
+/**
+ * Flags to control status callbacks
+ *
+ * - GIT_STATUS_OPT_INCLUDE_UNTRACKED says that callbacks should be made
+ *   on untracked files.  These will only be made if the workdir files are
+ *   included in the status "show" option.
+ * - GIT_STATUS_OPT_INCLUDE_IGNORED says that ignored files get callbacks.
+ *   Again, these callbacks will only be made if the workdir files are
+ *   included in the status "show" option.
+ * - GIT_STATUS_OPT_INCLUDE_UNMODIFIED indicates that callback should be
+ *   made even on unmodified files.
+ * - GIT_STATUS_OPT_EXCLUDE_SUBMODULES indicates that submodules should be
+ *   skipped.  This only applies if there are no pending typechanges to
+ *   the submodule (either from or to another type).
+ * - GIT_STATUS_OPT_RECURSE_UNTRACKED_DIRS indicates that all files in
+ *   untracked directories should be included.  Normally if an entire
+ *   directory is new, then just the top-level directory is included (with
+ *   a trailing slash on the entry name).  This flag says to include all
+ *   of the individual files in the directory instead.
+ * - GIT_STATUS_OPT_DISABLE_PATHSPEC_MATCH indicates that the given path
+ *   should be treated as a literal path, and not as a pathspec pattern.
+ * - GIT_STATUS_OPT_RECURSE_IGNORED_DIRS indicates that the contents of
+ *   ignored directories should be included in the status.  This is like
+ *   doing `git ls-files -o -i --exclude-standard` with core git.
+ * - GIT_STATUS_OPT_RENAMES_HEAD_TO_INDEX indicates that rename detection
+ *   should be processed between the head and the index and enables
+ *   the GIT_STATUS_INDEX_RENAMED as a possible status flag.
+ * - GIT_STATUS_OPT_RENAMES_INDEX_TO_WORKDIR indicates that rename
+ *   detection should be run between the index and the working directory
+ *   and enabled GIT_STATUS_WT_RENAMED as a possible status flag.
+ * - GIT_STATUS_OPT_SORT_CASE_SENSITIVELY overrides the native case
+ *   sensitivity for the file system and forces the output to be in
+ *   case-sensitive order
+ * - GIT_STATUS_OPT_SORT_CASE_INSENSITIVELY overrides the native case
+ *   sensitivity for the file system and forces the output to be in
+ *   case-insensitive order
+ * - GIT_STATUS_OPT_RENAMES_FROM_REWRITES indicates that rename detection
+ *   should include rewritten files
+ * - GIT_STATUS_OPT_NO_REFRESH bypasses the default status behavior of
+ *   doing a "soft" index reload (i.e. reloading the index data if the
+ *   file on disk has been modified outside libgit2).
+ * - GIT_STATUS_OPT_UPDATE_INDEX tells libgit2 to refresh the stat cache
+ *   in the index for files that are unchanged but have out of date stat
+ *   information in the index.  It will result in less work being done on
+ *   subsequent calls to get status.  This is mutually exclusive with the
+ *   NO_REFRESH option.
+ *
+ * Calling `git_status_foreach()` is like calling the extended version
+ * with: GIT_STATUS_OPT_INCLUDE_IGNORED, GIT_STATUS_OPT_INCLUDE_UNTRACKED,
+ * and GIT_STATUS_OPT_RECURSE_UNTRACKED_DIRS.  Those options are bundled
+ * together as `GIT_STATUS_OPT_DEFAULTS` if you want them as a baseline.
+ */
+typedef enum {
+	GIT_STATUS_OPT_INCLUDE_UNTRACKED                = (1u << 0),
+	GIT_STATUS_OPT_INCLUDE_IGNORED                  = (1u << 1),
+	GIT_STATUS_OPT_INCLUDE_UNMODIFIED               = (1u << 2),
+	GIT_STATUS_OPT_EXCLUDE_SUBMODULES               = (1u << 3),
+	GIT_STATUS_OPT_RECURSE_UNTRACKED_DIRS           = (1u << 4),
+	GIT_STATUS_OPT_DISABLE_PATHSPEC_MATCH           = (1u << 5),
+	GIT_STATUS_OPT_RECURSE_IGNORED_DIRS             = (1u << 6),
+	GIT_STATUS_OPT_RENAMES_HEAD_TO_INDEX            = (1u << 7),
+	GIT_STATUS_OPT_RENAMES_INDEX_TO_WORKDIR         = (1u << 8),
+	GIT_STATUS_OPT_SORT_CASE_SENSITIVELY            = (1u << 9),
+	GIT_STATUS_OPT_SORT_CASE_INSENSITIVELY          = (1u << 10),
+	GIT_STATUS_OPT_RENAMES_FROM_REWRITES            = (1u << 11),
+	GIT_STATUS_OPT_NO_REFRESH                       = (1u << 12),
+	GIT_STATUS_OPT_UPDATE_INDEX                     = (1u << 13),
+	GIT_STATUS_OPT_INCLUDE_UNREADABLE               = (1u << 14),
+	GIT_STATUS_OPT_INCLUDE_UNREADABLE_AS_UNTRACKED  = (1u << 15),
+} git_status_opt_t;
+
+#define GIT_STATUS_OPT_DEFAULTS \
+	(GIT_STATUS_OPT_INCLUDE_IGNORED | \
+	GIT_STATUS_OPT_INCLUDE_UNTRACKED | \
+	GIT_STATUS_OPT_RECURSE_UNTRACKED_DIRS)
+
+/**
+ * Options to control how `git_status_foreach_ext()` will issue callbacks.
+ *
+ * This structure is set so that zeroing it out will give you relatively
+ * sane defaults.
+ *
+ * The `show` value is one of the `git_status_show_t` constants that
+ * control which files to scan and in what order.
+ *
+ * The `flags` value is an OR'ed combination of the `git_status_opt_t`
+ * values above.
+ *
+ * The `pathspec` is an array of path patterns to match (using
+ * fnmatch-style matching), or just an array of paths to match exactly if
+ * `GIT_STATUS_OPT_DISABLE_PATHSPEC_MATCH` is specified in the flags.
+ *
+ * The `baseline` is the tree to be used for comparison to the working directory
+ * and index; defaults to HEAD.
+ */
+typedef struct {
+	unsigned int      version;
+	git_status_show_t show;
+	unsigned int      flags;
+	git_strarray      pathspec;
+	git_tree          *baseline;
+} git_status_options;
+
+#define GIT_STATUS_OPTIONS_VERSION 1
+#define GIT_STATUS_OPTIONS_INIT {GIT_STATUS_OPTIONS_VERSION}
+
+/**
+ * Initializes a `git_status_options` with default values. Equivalent to
+ * creating an instance with GIT_STATUS_OPTIONS_INIT.
+ *
+ * @param opts The `git_status_options` instance to initialize.
+ * @param version Version of struct; pass `GIT_STATUS_OPTIONS_VERSION`
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_status_init_options(
+	git_status_options *opts,
+	unsigned int version);
+
+/**
+ * A status entry, providing the differences between the file as it exists
+ * in HEAD and the index, and providing the differences between the index
+ * and the working directory.
+ *
+ * The `status` value provides the status flags for this file.
+ *
+ * The `head_to_index` value provides detailed information about the
+ * differences between the file in HEAD and the file in the index.
+ *
+ * The `index_to_workdir` value provides detailed information about the
+ * differences between the file in the index and the file in the
+ * working directory.
+ */
+typedef struct {
+	git_status_t status;
+	git_diff_delta *head_to_index;
+	git_diff_delta *index_to_workdir;
+} git_status_entry;
+
+
+/**
+ * Gather file statuses and run a callback for each one.
+ *
+ * The callback is passed the path of the file, the status (a combination of
+ * the `git_status_t` values above) and the `payload` data pointer passed
+ * into this function.
+ *
+ * If the callback returns a non-zero value, this function will stop looping
+ * and return that value to caller.
+ *
+ * @param repo A repository object
+ * @param callback The function to call on each file
+ * @param payload Pointer to pass through to callback function
+ * @return 0 on success, non-zero callback return value, or error code
+ */
+GIT_EXTERN(int) git_status_foreach(
+	git_repository *repo,
+	git_status_cb callback,
+	void *payload);
+
+/**
+ * Gather file status information and run callbacks as requested.
+ *
+ * This is an extended version of the `git_status_foreach()` API that
+ * allows for more granular control over which paths will be processed and
+ * in what order.  See the `git_status_options` structure for details
+ * about the additional controls that this makes available.
+ *
+ * Note that if a `pathspec` is given in the `git_status_options` to filter
+ * the status, then the results from rename detection (if you enable it) may
+ * not be accurate.  To do rename detection properly, this must be called
+ * with no `pathspec` so that all files can be considered.
+ *
+ * @param repo Repository object
+ * @param opts Status options structure
+ * @param callback The function to call on each file
+ * @param payload Pointer to pass through to callback function
+ * @return 0 on success, non-zero callback return value, or error code
+ */
+GIT_EXTERN(int) git_status_foreach_ext(
+	git_repository *repo,
+	const git_status_options *opts,
+	git_status_cb callback,
+	void *payload);
+
+/**
+ * Get file status for a single file.
+ *
+ * This tries to get status for the filename that you give.  If no files
+ * match that name (in either the HEAD, index, or working directory), this
+ * returns GIT_ENOTFOUND.
+ *
+ * If the name matches multiple files (for example, if the `path` names a
+ * directory or if running on a case- insensitive filesystem and yet the
+ * HEAD has two entries that both match the path), then this returns
+ * GIT_EAMBIGUOUS because it cannot give correct results.
+ *
+ * This does not do any sort of rename detection.  Renames require a set of
+ * targets and because of the path filtering, there is not enough
+ * information to check renames correctly.  To check file status with rename
+ * detection, there is no choice but to do a full `git_status_list_new` and
+ * scan through looking for the path that you are interested in.
+ *
+ * @param status_flags Output combination of git_status_t values for file
+ * @param repo A repository object
+ * @param path The exact path to retrieve status for relative to the
+ * repository working directory
+ * @return 0 on success, GIT_ENOTFOUND if the file is not found in the HEAD,
+ *      index, and work tree, GIT_EAMBIGUOUS if `path` matches multiple files
+ *      or if it refers to a folder, and -1 on other errors.
+ */
+GIT_EXTERN(int) git_status_file(
+	unsigned int *status_flags,
+	git_repository *repo,
+	const char *path);
+
+/**
+ * Gather file status information and populate the `git_status_list`.
+ *
+ * Note that if a `pathspec` is given in the `git_status_options` to filter
+ * the status, then the results from rename detection (if you enable it) may
+ * not be accurate.  To do rename detection properly, this must be called
+ * with no `pathspec` so that all files can be considered.
+ *
+ * @param out Pointer to store the status results in
+ * @param repo Repository object
+ * @param opts Status options structure
+ * @return 0 on success or error code
+ */
+GIT_EXTERN(int) git_status_list_new(
+	git_status_list **out,
+	git_repository *repo,
+	const git_status_options *opts);
+
+/**
+ * Gets the count of status entries in this list.
+ *
+ * If there are no changes in status (at least according the options given
+ * when the status list was created), this can return 0.
+ *
+ * @param statuslist Existing status list object
+ * @return the number of status entries
+ */
+GIT_EXTERN(size_t) git_status_list_entrycount(
+	git_status_list *statuslist);
+
+/**
+ * Get a pointer to one of the entries in the status list.
+ *
+ * The entry is not modifiable and should not be freed.
+ *
+ * @param statuslist Existing status list object
+ * @param idx Position of the entry
+ * @return Pointer to the entry; NULL if out of bounds
+ */
+GIT_EXTERN(const git_status_entry *) git_status_byindex(
+	git_status_list *statuslist,
+	size_t idx);
+
+/**
+ * Free an existing status list
+ *
+ * @param statuslist Existing status list object
+ */
+GIT_EXTERN(void) git_status_list_free(
+	git_status_list *statuslist);
+
+/**
+ * Test if the ignore rules apply to a given file.
+ *
+ * This function checks the ignore rules to see if they would apply to the
+ * given file.  This indicates if the file would be ignored regardless of
+ * whether the file is already in the index or committed to the repository.
+ *
+ * One way to think of this is if you were to do "git add ." on the
+ * directory containing the file, would it be added or not?
+ *
+ * @param ignored Boolean returning 0 if the file is not ignored, 1 if it is
+ * @param repo A repository object
+ * @param path The file to check ignores for, rooted at the repo's workdir.
+ * @return 0 if ignore rules could be processed for the file (regardless
+ *         of whether it exists or not), or an error < 0 if they could not.
+ */
+GIT_EXTERN(int) git_status_should_ignore(
+	int *ignored,
+	git_repository *repo,
+	const char *path);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/stdint.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/stdint.h b/vendor/libgit2-sys/libgit2/include/git2/stdint.h
new file mode 100644
index 0000000..c66fbb8
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/stdint.h
@@ -0,0 +1,247 @@
+// ISO C9x  compliant stdint.h for Microsoft Visual Studio
+// Based on ISO/IEC 9899:TC2 Committee draft (May 6, 2005) WG14/N1124
+//
+//  Copyright (c) 2006-2008 Alexander Chemeris
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//   1. Redistributions of source code must retain the above copyright notice,
+//      this list of conditions and the following disclaimer.
+//
+//   2. Redistributions in binary form must reproduce the above copyright
+//      notice, this list of conditions and the following disclaimer in the
+//      documentation and/or other materials provided with the distribution.
+//
+//   3. The name of the author may be used to endorse or promote products
+//      derived from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+// WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+// EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+// OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+// WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+// OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+// ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef _MSC_VER // [
+#error "Use this header only with Microsoft Visual C++ compilers!"
+#endif // _MSC_VER ]
+
+#ifndef _MSC_STDINT_H_ // [
+#define _MSC_STDINT_H_
+
+#if _MSC_VER > 1000
+#pragma once
+#endif
+
+#include <limits.h>
+
+// For Visual Studio 6 in C++ mode and for many Visual Studio versions when
+// compiling for ARM we should wrap <wchar.h> include with 'extern "C++" {}'
+// or compiler give many errors like this:
+//   error C2733: second C linkage of overloaded function 'wmemchr' not allowed
+#ifdef __cplusplus
+extern "C" {
+#endif
+#  include <wchar.h>
+#ifdef __cplusplus
+}
+#endif
+
+// Define _W64 macros to mark types changing their size, like intptr_t.
+#ifndef _W64
+#  if !defined(__midl) && (defined(_X86_) || defined(_M_IX86)) && _MSC_VER >= 1300
+#     define _W64 __w64
+#  else
+#     define _W64
+#  endif
+#endif
+
+
+// 7.18.1 Integer types
+
+// 7.18.1.1 Exact-width integer types
+
+// Visual Studio 6 and Embedded Visual C++ 4 doesn't
+// realize that, e.g. char has the same size as __int8
+// so we give up on __intX for them.
+#if (_MSC_VER < 1300)
+   typedef signed char       int8_t;
+   typedef signed short      int16_t;
+   typedef signed int        int32_t;
+   typedef unsigned char     uint8_t;
+   typedef unsigned short    uint16_t;
+   typedef unsigned int      uint32_t;
+#else
+   typedef signed __int8     int8_t;
+   typedef signed __int16    int16_t;
+   typedef signed __int32    int32_t;
+   typedef unsigned __int8   uint8_t;
+   typedef unsigned __int16  uint16_t;
+   typedef unsigned __int32  uint32_t;
+#endif
+typedef signed __int64       int64_t;
+typedef unsigned __int64     uint64_t;
+
+
+// 7.18.1.2 Minimum-width integer types
+typedef int8_t    int_least8_t;
+typedef int16_t   int_least16_t;
+typedef int32_t   int_least32_t;
+typedef int64_t   int_least64_t;
+typedef uint8_t   uint_least8_t;
+typedef uint16_t  uint_least16_t;
+typedef uint32_t  uint_least32_t;
+typedef uint64_t  uint_least64_t;
+
+// 7.18.1.3 Fastest minimum-width integer types
+typedef int8_t    int_fast8_t;
+typedef int16_t   int_fast16_t;
+typedef int32_t   int_fast32_t;
+typedef int64_t   int_fast64_t;
+typedef uint8_t   uint_fast8_t;
+typedef uint16_t  uint_fast16_t;
+typedef uint32_t  uint_fast32_t;
+typedef uint64_t  uint_fast64_t;
+
+// 7.18.1.4 Integer types capable of holding object pointers
+#ifdef _WIN64 // [
+   typedef signed __int64    intptr_t;
+   typedef unsigned __int64  uintptr_t;
+#else // _WIN64 ][
+   typedef _W64 signed int   intptr_t;
+   typedef _W64 unsigned int uintptr_t;
+#endif // _WIN64 ]
+
+// 7.18.1.5 Greatest-width integer types
+typedef int64_t   intmax_t;
+typedef uint64_t  uintmax_t;
+
+
+// 7.18.2 Limits of specified-width integer types
+
+#if !defined(__cplusplus) || defined(__STDC_LIMIT_MACROS) // [   See footnote 220 at page 257 and footnote 221 at page 259
+
+// 7.18.2.1 Limits of exact-width integer types
+#define INT8_MIN     ((int8_t)_I8_MIN)
+#define INT8_MAX     _I8_MAX
+#define INT16_MIN    ((int16_t)_I16_MIN)
+#define INT16_MAX    _I16_MAX
+#define INT32_MIN    ((int32_t)_I32_MIN)
+#define INT32_MAX    _I32_MAX
+#define INT64_MIN    ((int64_t)_I64_MIN)
+#define INT64_MAX    _I64_MAX
+#define UINT8_MAX    _UI8_MAX
+#define UINT16_MAX   _UI16_MAX
+#define UINT32_MAX   _UI32_MAX
+#define UINT64_MAX   _UI64_MAX
+
+// 7.18.2.2 Limits of minimum-width integer types
+#define INT_LEAST8_MIN    INT8_MIN
+#define INT_LEAST8_MAX    INT8_MAX
+#define INT_LEAST16_MIN   INT16_MIN
+#define INT_LEAST16_MAX   INT16_MAX
+#define INT_LEAST32_MIN   INT32_MIN
+#define INT_LEAST32_MAX   INT32_MAX
+#define INT_LEAST64_MIN   INT64_MIN
+#define INT_LEAST64_MAX   INT64_MAX
+#define UINT_LEAST8_MAX   UINT8_MAX
+#define UINT_LEAST16_MAX  UINT16_MAX
+#define UINT_LEAST32_MAX  UINT32_MAX
+#define UINT_LEAST64_MAX  UINT64_MAX
+
+// 7.18.2.3 Limits of fastest minimum-width integer types
+#define INT_FAST8_MIN    INT8_MIN
+#define INT_FAST8_MAX    INT8_MAX
+#define INT_FAST16_MIN   INT16_MIN
+#define INT_FAST16_MAX   INT16_MAX
+#define INT_FAST32_MIN   INT32_MIN
+#define INT_FAST32_MAX   INT32_MAX
+#define INT_FAST64_MIN   INT64_MIN
+#define INT_FAST64_MAX   INT64_MAX
+#define UINT_FAST8_MAX   UINT8_MAX
+#define UINT_FAST16_MAX  UINT16_MAX
+#define UINT_FAST32_MAX  UINT32_MAX
+#define UINT_FAST64_MAX  UINT64_MAX
+
+// 7.18.2.4 Limits of integer types capable of holding object pointers
+#ifdef _WIN64 // [
+#  define INTPTR_MIN   INT64_MIN
+#  define INTPTR_MAX   INT64_MAX
+#  define UINTPTR_MAX  UINT64_MAX
+#else // _WIN64 ][
+#  define INTPTR_MIN   INT32_MIN
+#  define INTPTR_MAX   INT32_MAX
+#  define UINTPTR_MAX  UINT32_MAX
+#endif // _WIN64 ]
+
+// 7.18.2.5 Limits of greatest-width integer types
+#define INTMAX_MIN   INT64_MIN
+#define INTMAX_MAX   INT64_MAX
+#define UINTMAX_MAX  UINT64_MAX
+
+// 7.18.3 Limits of other integer types
+
+#ifdef _WIN64 // [
+#  define PTRDIFF_MIN  _I64_MIN
+#  define PTRDIFF_MAX  _I64_MAX
+#else  // _WIN64 ][
+#  define PTRDIFF_MIN  _I32_MIN
+#  define PTRDIFF_MAX  _I32_MAX
+#endif  // _WIN64 ]
+
+#define SIG_ATOMIC_MIN  INT_MIN
+#define SIG_ATOMIC_MAX  INT_MAX
+
+#ifndef SIZE_MAX // [
+#  ifdef _WIN64 // [
+#     define SIZE_MAX  _UI64_MAX
+#  else // _WIN64 ][
+#     define SIZE_MAX  _UI32_MAX
+#  endif // _WIN64 ]
+#endif // SIZE_MAX ]
+
+// WCHAR_MIN and WCHAR_MAX are also defined in <wchar.h>
+#ifndef WCHAR_MIN // [
+#  define WCHAR_MIN  0
+#endif  // WCHAR_MIN ]
+#ifndef WCHAR_MAX // [
+#  define WCHAR_MAX  _UI16_MAX
+#endif  // WCHAR_MAX ]
+
+#define WINT_MIN  0
+#define WINT_MAX  _UI16_MAX
+
+#endif // __STDC_LIMIT_MACROS ]
+
+
+// 7.18.4 Limits of other integer types
+
+#if !defined(__cplusplus) || defined(__STDC_CONSTANT_MACROS) // [   See footnote 224 at page 260
+
+// 7.18.4.1 Macros for minimum-width integer constants
+
+#define INT8_C(val)  val##i8
+#define INT16_C(val) val##i16
+#define INT32_C(val) val##i32
+#define INT64_C(val) val##i64
+
+#define UINT8_C(val)  val##ui8
+#define UINT16_C(val) val##ui16
+#define UINT32_C(val) val##ui32
+#define UINT64_C(val) val##ui64
+
+// 7.18.4.2 Macros for greatest-width integer constants
+#define INTMAX_C   INT64_C
+#define UINTMAX_C  UINT64_C
+
+#endif // __STDC_CONSTANT_MACROS ]
+
+
+#endif // _MSC_STDINT_H_ ]

vendor/libgit2-sys/libgit2/include/git2/strarray.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/strarray.h b/vendor/libgit2-sys/libgit2/include/git2/strarray.h
new file mode 100644
index 0000000..86fa25f
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/strarray.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_strarray_h__
+#define INCLUDE_git_strarray_h__
+
+#include "common.h"
+
+/**
+ * @file git2/strarray.h
+ * @brief Git string array routines
+ * @defgroup git_strarray Git string array routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/** Array of strings */
+typedef struct git_strarray {
+	char **strings;
+	size_t count;
+} git_strarray;
+
+/**
+ * Close a string array object
+ *
+ * This method should be called on `git_strarray` objects where the strings
+ * array is allocated and contains allocated strings, such as what you
+ * would get from `git_strarray_copy()`.  Not doing so, will result in a
+ * memory leak.
+ *
+ * This does not free the `git_strarray` itself, since the library will
+ * never allocate that object directly itself (it is more commonly embedded
+ * inside another struct or created on the stack).
+ *
+ * @param array git_strarray from which to free string data
+ */
+GIT_EXTERN(void) git_strarray_free(git_strarray *array);
+
+/**
+ * Copy a string array object from source to target.
+ *
+ * Note: target is overwritten and hence should be empty, otherwise its
+ * contents are leaked.  Call git_strarray_free() if necessary.
+ *
+ * @param tgt target
+ * @param src source
+ * @return 0 on success, < 0 on allocation failure
+ */
+GIT_EXTERN(int) git_strarray_copy(git_strarray *tgt, const git_strarray *src);
+
+
+/** @} */
+GIT_END_DECL
+
+#endif
+

vendor/libgit2-sys/libgit2/include/git2/submodule.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/submodule.h b/vendor/libgit2-sys/libgit2/include/git2/submodule.h
new file mode 100644
index 0000000..b2b3039
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/submodule.h
@@ -0,0 +1,636 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_submodule_h__
+#define INCLUDE_git_submodule_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+#include "remote.h"
+#include "checkout.h"
+
+/**
+ * @file git2/submodule.h
+ * @brief Git submodule management utilities
+ *
+ * Submodule support in libgit2 builds a list of known submodules and keeps
+ * it in the repository.  The list is built from the .gitmodules file, the
+ * .git/config file, the index, and the HEAD tree.  Items in the working
+ * directory that look like submodules (i.e. a git repo) but are not
+ * mentioned in those places won't be tracked.
+ *
+ * @defgroup git_submodule Git submodule management routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Return codes for submodule status.
+ *
+ * A combination of these flags will be returned to describe the status of a
+ * submodule.  Depending on the "ignore" property of the submodule, some of
+ * the flags may never be returned because they indicate changes that are
+ * supposed to be ignored.
+ *
+ * Submodule info is contained in 4 places: the HEAD tree, the index, config
+ * files (both .git/config and .gitmodules), and the working directory.  Any
+ * or all of those places might be missing information about the submodule
+ * depending on what state the repo is in.  We consider all four places to
+ * build the combination of status flags.
+ *
+ * There are four values that are not really status, but give basic info
+ * about what sources of submodule data are available.  These will be
+ * returned even if ignore is set to "ALL".
+ *
+ * * IN_HEAD   - superproject head contains submodule
+ * * IN_INDEX  - superproject index contains submodule
+ * * IN_CONFIG - superproject gitmodules has submodule
+ * * IN_WD     - superproject workdir has submodule
+ *
+ * The following values will be returned so long as ignore is not "ALL".
+ *
+ * * INDEX_ADDED       - in index, not in head
+ * * INDEX_DELETED     - in head, not in index
+ * * INDEX_MODIFIED    - index and head don't match
+ * * WD_UNINITIALIZED  - workdir contains empty directory
+ * * WD_ADDED          - in workdir, not index
+ * * WD_DELETED        - in index, not workdir
+ * * WD_MODIFIED       - index and workdir head don't match
+ *
+ * The following can only be returned if ignore is "NONE" or "UNTRACKED".
+ *
+ * * WD_INDEX_MODIFIED - submodule workdir index is dirty
+ * * WD_WD_MODIFIED    - submodule workdir has modified files
+ *
+ * Lastly, the following will only be returned for ignore "NONE".
+ *
+ * * WD_UNTRACKED      - wd contains untracked files
+ */
+typedef enum {
+	GIT_SUBMODULE_STATUS_IN_HEAD           = (1u << 0),
+	GIT_SUBMODULE_STATUS_IN_INDEX          = (1u << 1),
+	GIT_SUBMODULE_STATUS_IN_CONFIG         = (1u << 2),
+	GIT_SUBMODULE_STATUS_IN_WD             = (1u << 3),
+	GIT_SUBMODULE_STATUS_INDEX_ADDED       = (1u << 4),
+	GIT_SUBMODULE_STATUS_INDEX_DELETED     = (1u << 5),
+	GIT_SUBMODULE_STATUS_INDEX_MODIFIED    = (1u << 6),
+	GIT_SUBMODULE_STATUS_WD_UNINITIALIZED  = (1u << 7),
+	GIT_SUBMODULE_STATUS_WD_ADDED          = (1u << 8),
+	GIT_SUBMODULE_STATUS_WD_DELETED        = (1u << 9),
+	GIT_SUBMODULE_STATUS_WD_MODIFIED       = (1u << 10),
+	GIT_SUBMODULE_STATUS_WD_INDEX_MODIFIED = (1u << 11),
+	GIT_SUBMODULE_STATUS_WD_WD_MODIFIED    = (1u << 12),
+	GIT_SUBMODULE_STATUS_WD_UNTRACKED      = (1u << 13),
+} git_submodule_status_t;
+
+#define GIT_SUBMODULE_STATUS__IN_FLAGS		0x000Fu
+#define GIT_SUBMODULE_STATUS__INDEX_FLAGS	0x0070u
+#define GIT_SUBMODULE_STATUS__WD_FLAGS		0x3F80u
+
+#define GIT_SUBMODULE_STATUS_IS_UNMODIFIED(S) \
+	(((S) & ~GIT_SUBMODULE_STATUS__IN_FLAGS) == 0)
+
+#define GIT_SUBMODULE_STATUS_IS_INDEX_UNMODIFIED(S) \
+	(((S) & GIT_SUBMODULE_STATUS__INDEX_FLAGS) == 0)
+
+#define GIT_SUBMODULE_STATUS_IS_WD_UNMODIFIED(S) \
+	(((S) & (GIT_SUBMODULE_STATUS__WD_FLAGS & \
+	~GIT_SUBMODULE_STATUS_WD_UNINITIALIZED)) == 0)
+
+#define GIT_SUBMODULE_STATUS_IS_WD_DIRTY(S) \
+	(((S) & (GIT_SUBMODULE_STATUS_WD_INDEX_MODIFIED | \
+	GIT_SUBMODULE_STATUS_WD_WD_MODIFIED | \
+	GIT_SUBMODULE_STATUS_WD_UNTRACKED)) != 0)
+
+/**
+ * Function pointer to receive each submodule
+ *
+ * @param sm git_submodule currently being visited
+ * @param name name of the submodule
+ * @param payload value you passed to the foreach function as payload
+ * @return 0 on success or error code
+ */
+typedef int (*git_submodule_cb)(
+	git_submodule *sm, const char *name, void *payload);
+
+/**
+ * Submodule update options structure
+ *
+ * Use the GIT_SUBMODULE_UPDATE_OPTIONS_INIT to get the default settings,
+ * like this:
+ *
+ * git_submodule_update_options opts = GIT_SUBMODULE_UPDATE_OPTIONS_INIT;
+ */
+typedef struct git_submodule_update_options {
+	unsigned int version;
+
+	/**
+	 * These options are passed to the checkout step. To disable
+	 * checkout, set the `checkout_strategy` to
+	 * `GIT_CHECKOUT_NONE`. Generally you will want the use
+	 * GIT_CHECKOUT_SAFE to update files in the working
+	 * directory. 
+	 */
+	git_checkout_options checkout_opts;
+
+	/**
+	 * Options which control the fetch, including callbacks.
+	 *
+	 * The callbacks to use for reporting fetch progress, and for acquiring
+	 * credentials in the event they are needed.
+	 */
+	git_fetch_options fetch_opts;
+
+	/**
+	 * Allow fetching from the submodule's default remote if the target
+	 * commit isn't found. Enabled by default.
+	 */
+	int allow_fetch;
+} git_submodule_update_options;
+
+#define GIT_SUBMODULE_UPDATE_OPTIONS_VERSION 1
+#define GIT_SUBMODULE_UPDATE_OPTIONS_INIT \
+	{ GIT_SUBMODULE_UPDATE_OPTIONS_VERSION, \
+		{ GIT_CHECKOUT_OPTIONS_VERSION, GIT_CHECKOUT_SAFE }, \
+	GIT_FETCH_OPTIONS_INIT, 1 }
+
+/**
+ * Initializes a `git_submodule_update_options` with default values.
+ * Equivalent to creating an instance with GIT_SUBMODULE_UPDATE_OPTIONS_INIT.
+ *
+ * @param opts The `git_submodule_update_options` instance to initialize.
+ * @param version Version of struct; pass `GIT_SUBMODULE_UPDATE_OPTIONS_VERSION`
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_submodule_update_init_options(
+	git_submodule_update_options *opts, unsigned int version);
+
+/**
+ * Update a submodule. This will clone a missing submodule and
+ * checkout the subrepository to the commit specified in the index of
+ * the containing repository. If the submodule repository doesn't contain
+ * the target commit (e.g. because fetchRecurseSubmodules isn't set), then
+ * the submodule is fetched using the fetch options supplied in options.
+ *
+ * @param submodule Submodule object
+ * @param init If the submodule is not initialized, setting this flag to true
+ *        will initialize the submodule before updating. Otherwise, this will
+ *        return an error if attempting to update an uninitialzed repository.
+ *        but setting this to true forces them to be updated.
+ * @param options configuration options for the update.  If NULL, the
+ *        function works as though GIT_SUBMODULE_UPDATE_OPTIONS_INIT was passed.
+ * @return 0 on success, any non-zero return value from a callback
+ *         function, or a negative value to indicate an error (use
+ *         `giterr_last` for a detailed error message).
+ */
+GIT_EXTERN(int) git_submodule_update(git_submodule *submodule, int init, git_submodule_update_options *options);
+
+/**
+ * Lookup submodule information by name or path.
+ *
+ * Given either the submodule name or path (they are usually the same), this
+ * returns a structure describing the submodule.
+ *
+ * There are two expected error scenarios:
+ *
+ * - The submodule is not mentioned in the HEAD, the index, and the config,
+ *   but does "exist" in the working directory (i.e. there is a subdirectory
+ *   that appears to be a Git repository).  In this case, this function
+ *   returns GIT_EEXISTS to indicate a sub-repository exists but not in a
+ *   state where a git_submodule can be instantiated.
+ * - The submodule is not mentioned in the HEAD, index, or config and the
+ *   working directory doesn't contain a value git repo at that path.
+ *   There may or may not be anything else at that path, but nothing that
+ *   looks like a submodule.  In this case, this returns GIT_ENOTFOUND.
+ *
+ * You must call `git_submodule_free` when done with the submodule.
+ *
+ * @param out Output ptr to submodule; pass NULL to just get return code
+ * @param repo The parent repository
+ * @param name The name of or path to the submodule; trailing slashes okay
+ * @return 0 on success, GIT_ENOTFOUND if submodule does not exist,
+ *         GIT_EEXISTS if a repository is found in working directory only,
+ *         -1 on other errors.
+ */
+GIT_EXTERN(int) git_submodule_lookup(
+	git_submodule **out,
+	git_repository *repo,
+	const char *name);
+
+/**
+ * Release a submodule
+ *
+ * @param submodule Submodule object
+ */
+GIT_EXTERN(void) git_submodule_free(git_submodule *submodule);
+
+/**
+ * Iterate over all tracked submodules of a repository.
+ *
+ * See the note on `git_submodule` above.  This iterates over the tracked
+ * submodules as described therein.
+ *
+ * If you are concerned about items in the working directory that look like
+ * submodules but are not tracked, the diff API will generate a diff record
+ * for workdir items that look like submodules but are not tracked, showing
+ * them as added in the workdir.  Also, the status API will treat the entire
+ * subdirectory of a contained git repo as a single GIT_STATUS_WT_NEW item.
+ *
+ * @param repo The repository
+ * @param callback Function to be called with the name of each submodule.
+ *        Return a non-zero value to terminate the iteration.
+ * @param payload Extra data to pass to callback
+ * @return 0 on success, -1 on error, or non-zero return value of callback
+ */
+GIT_EXTERN(int) git_submodule_foreach(
+	git_repository *repo,
+	git_submodule_cb callback,
+	void *payload);
+
+/**
+ * Set up a new git submodule for checkout.
+ *
+ * This does "git submodule add" up to the fetch and checkout of the
+ * submodule contents.  It preps a new submodule, creates an entry in
+ * .gitmodules and creates an empty initialized repository either at the
+ * given path in the working directory or in .git/modules with a gitlink
+ * from the working directory to the new repo.
+ *
+ * To fully emulate "git submodule add" call this function, then open the
+ * submodule repo and perform the clone step as needed.  Lastly, call
+ * `git_submodule_add_finalize()` to wrap up adding the new submodule and
+ * .gitmodules to the index to be ready to commit.
+ *
+ * You must call `git_submodule_free` on the submodule object when done.
+ *
+ * @param out The newly created submodule ready to open for clone
+ * @param repo The repository in which you want to create the submodule
+ * @param url URL for the submodule's remote
+ * @param path Path at which the submodule should be created
+ * @param use_gitlink Should workdir contain a gitlink to the repo in
+ *        .git/modules vs. repo directly in workdir.
+ * @return 0 on success, GIT_EEXISTS if submodule already exists,
+ *         -1 on other errors.
+ */
+GIT_EXTERN(int) git_submodule_add_setup(
+	git_submodule **out,
+	git_repository *repo,
+	const char *url,
+	const char *path,
+	int use_gitlink);
+
+/**
+ * Resolve the setup of a new git submodule.
+ *
+ * This should be called on a submodule once you have called add setup
+ * and done the clone of the submodule.  This adds the .gitmodules file
+ * and the newly cloned submodule to the index to be ready to be committed
+ * (but doesn't actually do the commit).
+ *
+ * @param submodule The submodule to finish adding.
+ */
+GIT_EXTERN(int) git_submodule_add_finalize(git_submodule *submodule);
+
+/**
+ * Add current submodule HEAD commit to index of superproject.
+ *
+ * @param submodule The submodule to add to the index
+ * @param write_index Boolean if this should immediately write the index
+ *            file.  If you pass this as false, you will have to get the
+ *            git_index and explicitly call `git_index_write()` on it to
+ *            save the change.
+ * @return 0 on success, <0 on failure
+ */
+GIT_EXTERN(int) git_submodule_add_to_index(
+	git_submodule *submodule,
+	int write_index);
+
+/**
+ * Get the containing repository for a submodule.
+ *
+ * This returns a pointer to the repository that contains the submodule.
+ * This is a just a reference to the repository that was passed to the
+ * original `git_submodule_lookup()` call, so if that repository has been
+ * freed, then this may be a dangling reference.
+ *
+ * @param submodule Pointer to submodule object
+ * @return Pointer to `git_repository`
+ */
+GIT_EXTERN(git_repository *) git_submodule_owner(git_submodule *submodule);
+
+/**
+ * Get the name of submodule.
+ *
+ * @param submodule Pointer to submodule object
+ * @return Pointer to the submodule name
+ */
+GIT_EXTERN(const char *) git_submodule_name(git_submodule *submodule);
+
+/**
+ * Get the path to the submodule.
+ *
+ * The path is almost always the same as the submodule name, but the
+ * two are actually not required to match.
+ *
+ * @param submodule Pointer to submodule object
+ * @return Pointer to the submodule path
+ */
+GIT_EXTERN(const char *) git_submodule_path(git_submodule *submodule);
+
+/**
+ * Get the URL for the submodule.
+ *
+ * @param submodule Pointer to submodule object
+ * @return Pointer to the submodule url
+ */
+GIT_EXTERN(const char *) git_submodule_url(git_submodule *submodule);
+
+/**
+ * Resolve a submodule url relative to the given repository.
+ *
+ * @param out buffer to store the absolute submodule url in
+ * @param repo Pointer to repository object
+ * @param url Relative url
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_submodule_resolve_url(git_buf *out, git_repository *repo, const char *url);
+
+/**
+* Get the branch for the submodule.
+*
+* @param submodule Pointer to submodule object
+* @return Pointer to the submodule branch
+*/
+GIT_EXTERN(const char *) git_submodule_branch(git_submodule *submodule);
+
+/**
+ * Set the branch for the submodule in the configuration
+ *
+ * After calling this, you may wish to call `git_submodule_sync()` to
+ * write the changes to the checked out submodule repository.
+ *
+ * @param repo the repository to affect
+ * @param name the name of the submodule to configure
+ * @param branch Branch that should be used for the submodule
+ * @return 0 on success, <0 on failure
+ */
+GIT_EXTERN(int) git_submodule_set_branch(git_repository *repo, const char *name, const char *branch);
+
+/**
+ * Set the URL for the submodule in the configuration
+ *
+ *
+ * After calling this, you may wish to call `git_submodule_sync()` to
+ * write the changes to the checked out submodule repository.
+ *
+ * @param repo the repository to affect
+ * @param name the name of the submodule to configure
+ * @param url URL that should be used for the submodule
+ * @return 0 on success, <0 on failure
+ */
+GIT_EXTERN(int) git_submodule_set_url(git_repository *repo, const char *name, const char *url);
+
+/**
+ * Get the OID for the submodule in the index.
+ *
+ * @param submodule Pointer to submodule object
+ * @return Pointer to git_oid or NULL if submodule is not in index.
+ */
+GIT_EXTERN(const git_oid *) git_submodule_index_id(git_submodule *submodule);
+
+/**
+ * Get the OID for the submodule in the current HEAD tree.
+ *
+ * @param submodule Pointer to submodule object
+ * @return Pointer to git_oid or NULL if submodule is not in the HEAD.
+ */
+GIT_EXTERN(const git_oid *) git_submodule_head_id(git_submodule *submodule);
+
+/**
+ * Get the OID for the submodule in the current working directory.
+ *
+ * This returns the OID that corresponds to looking up 'HEAD' in the checked
+ * out submodule.  If there are pending changes in the index or anything
+ * else, this won't notice that.  You should call `git_submodule_status()`
+ * for a more complete picture about the state of the working directory.
+ *
+ * @param submodule Pointer to submodule object
+ * @return Pointer to git_oid or NULL if submodule is not checked out.
+ */
+GIT_EXTERN(const git_oid *) git_submodule_wd_id(git_submodule *submodule);
+
+/**
+ * Get the ignore rule that will be used for the submodule.
+ *
+ * These values control the behavior of `git_submodule_status()` for this
+ * submodule.  There are four ignore values:
+ *
+ *  - **GIT_SUBMODULE_IGNORE_NONE** will consider any change to the contents
+ *    of the submodule from a clean checkout to be dirty, including the
+ *    addition of untracked files.  This is the default if unspecified.
+ *  - **GIT_SUBMODULE_IGNORE_UNTRACKED** examines the contents of the
+ *    working tree (i.e. call `git_status_foreach()` on the submodule) but
+ *    UNTRACKED files will not count as making the submodule dirty.
+ *  - **GIT_SUBMODULE_IGNORE_DIRTY** means to only check if the HEAD of the
+ *    submodule has moved for status.  This is fast since it does not need to
+ *    scan the working tree of the submodule at all.
+ *  - **GIT_SUBMODULE_IGNORE_ALL** means not to open the submodule repo.
+ *    The working directory will be consider clean so long as there is a
+ *    checked out version present.
+ *
+ * @param submodule The submodule to check
+ * @return The current git_submodule_ignore_t valyue what will be used for
+ *         this submodule.
+ */
+GIT_EXTERN(git_submodule_ignore_t) git_submodule_ignore(
+	git_submodule *submodule);
+
+/**
+ * Set the ignore rule for the submodule in the configuration
+ *
+ * This does not affect any currently-loaded instances.
+ *
+ * @param repo the repository to affect
+ * @param name the name of the submdule
+ * @param ignore The new value for the ignore rule
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_submodule_set_ignore(
+	git_repository *repo,
+	const char *name,
+	git_submodule_ignore_t ignore);
+
+/**
+ * Get the update rule that will be used for the submodule.
+ *
+ * This value controls the behavior of the `git submodule update` command.
+ * There are four useful values documented with `git_submodule_update_t`.
+ *
+ * @param submodule The submodule to check
+ * @return The current git_submodule_update_t value that will be used
+ *         for this submodule.
+ */
+GIT_EXTERN(git_submodule_update_t) git_submodule_update_strategy(
+	git_submodule *submodule);
+
+/**
+ * Set the update rule for the submodule in the configuration
+ *
+ * This setting won't affect any existing instances.
+ *
+ * @param repo the repository to affect
+ * @param name the name of the submodule to configure
+ * @param update The new value to use
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_submodule_set_update(
+	git_repository *repo,
+	const char *name,
+	git_submodule_update_t update);
+
+/**
+ * Read the fetchRecurseSubmodules rule for a submodule.
+ *
+ * This accesses the submodule.<name>.fetchRecurseSubmodules value for
+ * the submodule that controls fetching behavior for the submodule.
+ *
+ * Note that at this time, libgit2 does not honor this setting and the
+ * fetch functionality current ignores submodules.
+ *
+ * @return 0 if fetchRecurseSubmodules is false, 1 if true
+ */
+GIT_EXTERN(git_submodule_recurse_t) git_submodule_fetch_recurse_submodules(
+	git_submodule *submodule);
+
+/**
+ * Set the fetchRecurseSubmodules rule for a submodule in the configuration
+ *
+ * This setting won't affect any existing instances.
+ *
+ * @param repo the repository to affect
+ * @param name the submodule to configure
+ * @param fetch_recurse_submodules Boolean value
+ * @return old value for fetchRecurseSubmodules
+ */
+GIT_EXTERN(int) git_submodule_set_fetch_recurse_submodules(
+	git_repository *repo,
+	const char *name,
+	git_submodule_recurse_t fetch_recurse_submodules);
+
+/**
+ * Copy submodule info into ".git/config" file.
+ *
+ * Just like "git submodule init", this copies information about the
+ * submodule into ".git/config".  You can use the accessor functions
+ * above to alter the in-memory git_submodule object and control what
+ * is written to the config, overriding what is in .gitmodules.
+ *
+ * @param submodule The submodule to write into the superproject config
+ * @param overwrite By default, existing entries will not be overwritten,
+ *                  but setting this to true forces them to be updated.
+ * @return 0 on success, <0 on failure.
+ */
+GIT_EXTERN(int) git_submodule_init(git_submodule *submodule, int overwrite);
+
+/**
+ * Set up the subrepository for a submodule in preparation for clone.
+ *
+ * This function can be called to init and set up a submodule
+ * repository from a submodule in preparation to clone it from
+ * its remote.
+ *
+ * @param out Output pointer to the created git repository.
+ * @param sm The submodule to create a new subrepository from.
+ * @param use_gitlink Should the workdir contain a gitlink to
+ *        the repo in .git/modules vs. repo directly in workdir.
+ * @return 0 on success, <0 on failure.
+ */
+GIT_EXTERN(int) git_submodule_repo_init(
+	git_repository **out,
+	const git_submodule *sm,
+	int use_gitlink);
+
+/**
+ * Copy submodule remote info into submodule repo.
+ *
+ * This copies the information about the submodules URL into the checked out
+ * submodule config, acting like "git submodule sync".  This is useful if
+ * you have altered the URL for the submodule (or it has been altered by a
+ * fetch of upstream changes) and you need to update your local repo.
+ */
+GIT_EXTERN(int) git_submodule_sync(git_submodule *submodule);
+
+/**
+ * Open the repository for a submodule.
+ *
+ * This is a newly opened repository object.  The caller is responsible for
+ * calling `git_repository_free()` on it when done.  Multiple calls to this
+ * function will return distinct `git_repository` objects.  This will only
+ * work if the submodule is checked out into the working directory.
+ *
+ * @param repo Pointer to the submodule repo which was opened
+ * @param submodule Submodule to be opened
+ * @return 0 on success, <0 if submodule repo could not be opened.
+ */
+GIT_EXTERN(int) git_submodule_open(
+	git_repository **repo,
+	git_submodule *submodule);
+
+/**
+ * Reread submodule info from config, index, and HEAD.
+ *
+ * Call this to reread cached submodule information for this submodule if
+ * you have reason to believe that it has changed.
+ *
+ * @param submodule The submodule to reload
+ * @param force Force reload even if the data doesn't seem out of date
+ * @return 0 on success, <0 on error
+ */
+GIT_EXTERN(int) git_submodule_reload(git_submodule *submodule, int force);
+
+/**
+ * Get the status for a submodule.
+ *
+ * This looks at a submodule and tries to determine the status.  It
+ * will return a combination of the `GIT_SUBMODULE_STATUS` values above.
+ * How deeply it examines the working directory to do this will depend
+ * on the `git_submodule_ignore_t` value for the submodule.
+ *
+ * @param status Combination of `GIT_SUBMODULE_STATUS` flags
+ * @param repo the repository in which to look
+ * @param name name of the submodule
+ * @param ignore the ignore rules to follow
+ * @return 0 on success, <0 on error
+ */
+GIT_EXTERN(int) git_submodule_status(
+	unsigned int *status,
+	git_repository *repo,
+	const char *name,
+	git_submodule_ignore_t ignore);
+
+/**
+ * Get the locations of submodule information.
+ *
+ * This is a bit like a very lightweight version of `git_submodule_status`.
+ * It just returns a made of the first four submodule status values (i.e.
+ * the ones like GIT_SUBMODULE_STATUS_IN_HEAD, etc) that tell you where the
+ * submodule data comes from (i.e. the HEAD commit, gitmodules file, etc.).
+ * This can be useful if you want to know if the submodule is present in the
+ * working directory at this point in time, etc.
+ *
+ * @param location_status Combination of first four `GIT_SUBMODULE_STATUS` flags
+ * @param submodule Submodule for which to get status
+ * @return 0 on success, <0 on error
+ */
+GIT_EXTERN(int) git_submodule_location(
+	unsigned int *location_status,
+	git_submodule *submodule);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/sys/commit.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/sys/commit.h b/vendor/libgit2-sys/libgit2/include/git2/sys/commit.h
new file mode 100644
index 0000000..627d3ae
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/sys/commit.h
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sys_git_commit_h__
+#define INCLUDE_sys_git_commit_h__
+
+#include "git2/common.h"
+#include "git2/types.h"
+#include "git2/oid.h"
+
+/**
+ * @file git2/sys/commit.h
+ * @brief Low-level Git commit creation
+ * @defgroup git_backend Git custom backend APIs
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Create new commit in the repository from a list of `git_oid` values.
+ *
+ * See documentation for `git_commit_create()` for information about the
+ * parameters, as the meaning is identical excepting that `tree` and
+ * `parents` now take `git_oid`.  This is a dangerous API in that nor
+ * the `tree`, neither the `parents` list of `git_oid`s are checked for
+ * validity.
+ *
+ * @see git_commit_create
+ */
+GIT_EXTERN(int) git_commit_create_from_ids(
+	git_oid *id,
+	git_repository *repo,
+	const char *update_ref,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message,
+	const git_oid *tree,
+	size_t parent_count,
+	const git_oid *parents[]);
+
+/**
+ * Callback function to return parents for commit.
+ *
+ * This is invoked with the count of the number of parents processed so far
+ * along with the user supplied payload.  This should return a git_oid of
+ * the next parent or NULL if all parents have been provided.
+ */
+typedef const git_oid *(*git_commit_parent_callback)(size_t idx, void *payload);
+
+/**
+ * Create a new commit in the repository with an callback to supply parents.
+ *
+ * See documentation for `git_commit_create()` for information about the
+ * parameters, as the meaning is identical excepting that `tree` takes a
+ * `git_oid` and doesn't check for validity, and `parent_cb` is invoked
+ * with `parent_payload` and should return `git_oid` values or NULL to
+ * indicate that all parents are accounted for.
+ *
+ * @see git_commit_create
+ */
+GIT_EXTERN(int) git_commit_create_from_callback(
+	git_oid *id,
+	git_repository *repo,
+	const char *update_ref,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message,
+	const git_oid *tree,
+	git_commit_parent_callback parent_cb,
+	void *parent_payload);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/sys/config.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/sys/config.h b/vendor/libgit2-sys/libgit2/include/git2/sys/config.h
new file mode 100644
index 0000000..ed20322
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/sys/config.h
@@ -0,0 +1,130 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sys_git_config_backend_h__
+#define INCLUDE_sys_git_config_backend_h__
+
+#include "git2/common.h"
+#include "git2/types.h"
+#include "git2/config.h"
+
+/**
+ * @file git2/sys/config.h
+ * @brief Git config backend routines
+ * @defgroup git_backend Git custom backend APIs
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Every iterator must have this struct as its first element, so the
+ * API can talk to it. You'd define your iterator as
+ *
+ *     struct my_iterator {
+ *             git_config_iterator parent;
+ *             ...
+ *     }
+ *
+ * and assign `iter->parent.backend` to your `git_config_backend`.
+ */
+struct git_config_iterator {
+	git_config_backend *backend;
+	unsigned int flags;
+
+	/**
+	 * Return the current entry and advance the iterator. The
+	 * memory belongs to the library.
+	 */
+	int (*next)(git_config_entry **entry, git_config_iterator *iter);
+
+	/**
+	 * Free the iterator
+	 */
+	void (*free)(git_config_iterator *iter);
+};
+
+/**
+ * Generic backend that implements the interface to
+ * access a configuration file
+ */
+struct git_config_backend {
+	unsigned int version;
+	/** True if this backend is for a snapshot */
+	int readonly;
+	struct git_config *cfg;
+
+	/* Open means open the file/database and parse if necessary */
+	int (*open)(struct git_config_backend *, git_config_level_t level, const git_repository *repo);
+	int (*get)(struct git_config_backend *, const char *key, git_config_entry **entry);
+	int (*set)(struct git_config_backend *, const char *key, const char *value);
+	int (*set_multivar)(git_config_backend *cfg, const char *name, const char *regexp, const char *value);
+	int (*del)(struct git_config_backend *, const char *key);
+	int (*del_multivar)(struct git_config_backend *, const char *key, const char *regexp);
+	int (*iterator)(git_config_iterator **, struct git_config_backend *);
+	/** Produce a read-only version of this backend */
+	int (*snapshot)(struct git_config_backend **, struct git_config_backend *);
+	/**
+	 * Lock this backend.
+	 *
+	 * Prevent any writes to the data store backing this
+	 * backend. Any updates must not be visible to any other
+	 * readers.
+	 */
+	int (*lock)(struct git_config_backend *);
+	/**
+	 * Unlock the data store backing this backend. If success is
+	 * true, the changes should be committed, otherwise rolled
+	 * back.
+	 */
+	int (*unlock)(struct git_config_backend *, int success);
+	void (*free)(struct git_config_backend *);
+};
+#define GIT_CONFIG_BACKEND_VERSION 1
+#define GIT_CONFIG_BACKEND_INIT {GIT_CONFIG_BACKEND_VERSION}
+
+/**
+ * Initializes a `git_config_backend` with default values. Equivalent to
+ * creating an instance with GIT_CONFIG_BACKEND_INIT.
+ *
+ * @param backend the `git_config_backend` struct to initialize.
+ * @param version Version of struct; pass `GIT_CONFIG_BACKEND_VERSION`
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_config_init_backend(
+	git_config_backend *backend,
+	unsigned int version);
+
+/**
+ * Add a generic config file instance to an existing config
+ *
+ * Note that the configuration object will free the file
+ * automatically.
+ *
+ * Further queries on this config object will access each
+ * of the config file instances in order (instances with
+ * a higher priority level will be accessed first).
+ *
+ * @param cfg the configuration to add the file to
+ * @param file the configuration file (backend) to add
+ * @param level the priority level of the backend
+ * @param repo optional repository to allow parsing of
+ *  conditional includes
+ * @param force if a config file already exists for the given
+ *  priority level, replace it
+ * @return 0 on success, GIT_EEXISTS when adding more than one file
+ *  for a given priority level (and force_replace set to 0), or error code
+ */
+GIT_EXTERN(int) git_config_add_backend(
+	git_config *cfg,
+	git_config_backend *file,
+	git_config_level_t level,
+	const git_repository *repo,
+	int force);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/sys/diff.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/sys/diff.h b/vendor/libgit2-sys/libgit2/include/git2/sys/diff.h
new file mode 100644
index 0000000..aefd7b9
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/sys/diff.h
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sys_git_diff_h__
+#define INCLUDE_sys_git_diff_h__
+
+#include "git2/common.h"
+#include "git2/types.h"
+#include "git2/oid.h"
+#include "git2/diff.h"
+#include "git2/status.h"
+
+/**
+ * @file git2/sys/diff.h
+ * @brief Low-level Git diff utilities
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Diff print callback that writes to a git_buf.
+ *
+ * This function is provided not for you to call it directly, but instead
+ * so you can use it as a function pointer to the `git_diff_print` or
+ * `git_patch_print` APIs.  When using those APIs, you specify a callback
+ * to actually handle the diff and/or patch data.
+ *
+ * Use this callback to easily write that data to a `git_buf` buffer.  You
+ * must pass a `git_buf *` value as the payload to the `git_diff_print`
+ * and/or `git_patch_print` function.  The data will be appended to the
+ * buffer (after any existing content).
+ */
+GIT_EXTERN(int) git_diff_print_callback__to_buf(
+	const git_diff_delta *delta,
+	const git_diff_hunk *hunk,
+	const git_diff_line *line,
+	void *payload); /**< payload must be a `git_buf *` */
+
+/**
+ * Diff print callback that writes to stdio FILE handle.
+ *
+ * This function is provided not for you to call it directly, but instead
+ * so you can use it as a function pointer to the `git_diff_print` or
+ * `git_patch_print` APIs.  When using those APIs, you specify a callback
+ * to actually handle the diff and/or patch data.
+ *
+ * Use this callback to easily write that data to a stdio FILE handle.  You
+ * must pass a `FILE *` value (such as `stdout` or `stderr` or the return
+ * value from `fopen()`) as the payload to the `git_diff_print`
+ * and/or `git_patch_print` function.  If you pass NULL, this will write
+ * data to `stdout`.
+ */
+GIT_EXTERN(int) git_diff_print_callback__to_file_handle(
+	const git_diff_delta *delta,
+	const git_diff_hunk *hunk,
+	const git_diff_line *line,
+	void *payload); /**< payload must be a `FILE *` */
+
+
+/**
+ * Performance data from diffing
+ */
+typedef struct {
+	unsigned int version;
+	size_t stat_calls; /**< Number of stat() calls performed */
+	size_t oid_calculations; /**< Number of ID calculations */
+} git_diff_perfdata;
+
+#define GIT_DIFF_PERFDATA_VERSION 1
+#define GIT_DIFF_PERFDATA_INIT {GIT_DIFF_PERFDATA_VERSION,0,0}
+
+/**
+ * Get performance data for a diff object.
+ *
+ * @param out Structure to be filled with diff performance data
+ * @param diff Diff to read performance data from
+ * @return 0 for success, <0 for error
+ */
+GIT_EXTERN(int) git_diff_get_perfdata(
+	git_diff_perfdata *out, const git_diff *diff);
+
+/**
+ * Get performance data for diffs from a git_status_list
+ */
+GIT_EXTERN(int) git_status_list_get_perfdata(
+	git_diff_perfdata *out, const git_status_list *status);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/sys/filter.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/sys/filter.h b/vendor/libgit2-sys/libgit2/include/git2/sys/filter.h
new file mode 100644
index 0000000..6d575d4
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/sys/filter.h
@@ -0,0 +1,332 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sys_git_filter_h__
+#define INCLUDE_sys_git_filter_h__
+
+#include "git2/filter.h"
+
+/**
+ * @file git2/sys/filter.h
+ * @brief Git filter backend and plugin routines
+ * @defgroup git_backend Git custom backend APIs
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Look up a filter by name
+ *
+ * @param name The name of the filter
+ * @return Pointer to the filter object or NULL if not found
+ */
+GIT_EXTERN(git_filter *) git_filter_lookup(const char *name);
+
+#define GIT_FILTER_CRLF  "crlf"
+#define GIT_FILTER_IDENT "ident"
+
+/**
+ * This is priority that the internal CRLF filter will be registered with
+ */
+#define GIT_FILTER_CRLF_PRIORITY 0
+
+/**
+ * This is priority that the internal ident filter will be registered with
+ */
+#define GIT_FILTER_IDENT_PRIORITY 100
+
+/**
+ * This is priority to use with a custom filter to imitate a core Git
+ * filter driver, so that it will be run last on checkout and first on
+ * checkin.  You do not have to use this, but it helps compatibility.
+ */
+#define GIT_FILTER_DRIVER_PRIORITY 200
+
+/**
+ * Create a new empty filter list
+ *
+ * Normally you won't use this because `git_filter_list_load` will create
+ * the filter list for you, but you can use this in combination with the
+ * `git_filter_lookup` and `git_filter_list_push` functions to assemble
+ * your own chains of filters.
+ */
+GIT_EXTERN(int) git_filter_list_new(
+	git_filter_list **out,
+	git_repository *repo,
+	git_filter_mode_t mode,
+	uint32_t options);
+
+/**
+ * Add a filter to a filter list with the given payload.
+ *
+ * Normally you won't have to do this because the filter list is created
+ * by calling the "check" function on registered filters when the filter
+ * attributes are set, but this does allow more direct manipulation of
+ * filter lists when desired.
+ *
+ * Note that normally the "check" function can set up a payload for the
+ * filter.  Using this function, you can either pass in a payload if you
+ * know the expected payload format, or you can pass NULL.  Some filters
+ * may fail with a NULL payload.  Good luck!
+ */
+GIT_EXTERN(int) git_filter_list_push(
+	git_filter_list *fl, git_filter *filter, void *payload);
+
+/**
+ * Look up how many filters are in the list
+ *
+ * We will attempt to apply all of these filters to any data passed in,
+ * but note that the filter apply action still has the option of skipping
+ * data that is passed in (for example, the CRLF filter will skip data
+ * that appears to be binary).
+ *
+ * @param fl A filter list
+ * @return The number of filters in the list
+ */
+GIT_EXTERN(size_t) git_filter_list_length(const git_filter_list *fl);
+
+/**
+ * A filter source represents a file/blob to be processed
+ */
+typedef struct git_filter_source git_filter_source;
+
+/**
+ * Get the repository that the source data is coming from.
+ */
+GIT_EXTERN(git_repository *) git_filter_source_repo(const git_filter_source *src);
+
+/**
+ * Get the path that the source data is coming from.
+ */
+GIT_EXTERN(const char *) git_filter_source_path(const git_filter_source *src);
+
+/**
+ * Get the file mode of the source file
+ * If the mode is unknown, this will return 0
+ */
+GIT_EXTERN(uint16_t) git_filter_source_filemode(const git_filter_source *src);
+
+/**
+ * Get the OID of the source
+ * If the OID is unknown (often the case with GIT_FILTER_CLEAN) then
+ * this will return NULL.
+ */
+GIT_EXTERN(const git_oid *) git_filter_source_id(const git_filter_source *src);
+
+/**
+ * Get the git_filter_mode_t to be used
+ */
+GIT_EXTERN(git_filter_mode_t) git_filter_source_mode(const git_filter_source *src);
+
+/**
+ * Get the combination git_filter_flag_t options to be applied
+ */
+GIT_EXTERN(uint32_t) git_filter_source_flags(const git_filter_source *src);
+
+/**
+ * Initialize callback on filter
+ *
+ * Specified as `filter.initialize`, this is an optional callback invoked
+ * before a filter is first used.  It will be called once at most.
+ *
+ * If non-NULL, the filter's `initialize` callback will be invoked right
+ * before the first use of the filter, so you can defer expensive
+ * initialization operations (in case libgit2 is being used in a way that
+ * doesn't need the filter).
+ */
+typedef int (*git_filter_init_fn)(git_filter *self);
+
+/**
+ * Shutdown callback on filter
+ *
+ * Specified as `filter.shutdown`, this is an optional callback invoked
+ * when the filter is unregistered or when libgit2 is shutting down.  It
+ * will be called once at most and should release resources as needed.
+ * This may be called even if the `initialize` callback was not made.
+ *
+ * Typically this function will free the `git_filter` object itself.
+ */
+typedef void (*git_filter_shutdown_fn)(git_filter *self);
+
+/**
+ * Callback to decide if a given source needs this filter
+ *
+ * Specified as `filter.check`, this is an optional callback that checks
+ * if filtering is needed for a given source.
+ *
+ * It should return 0 if the filter should be applied (i.e. success),
+ * GIT_PASSTHROUGH if the filter should not be applied, or an error code
+ * to fail out of the filter processing pipeline and return to the caller.
+ *
+ * The `attr_values` will be set to the values of any attributes given in
+ * the filter definition.  See `git_filter` below for more detail.
+ *
+ * The `payload` will be a pointer to a reference payload for the filter.
+ * This will start as NULL, but `check` can assign to this pointer for
+ * later use by the `apply` callback.  Note that the value should be heap
+ * allocated (not stack), so that it doesn't go away before the `apply`
+ * callback can use it.  If a filter allocates and assigns a value to the
+ * `payload`, it will need a `cleanup` callback to free the payload.
+ */
+typedef int (*git_filter_check_fn)(
+	git_filter  *self,
+	void       **payload, /* points to NULL ptr on entry, may be set */
+	const git_filter_source *src,
+	const char **attr_values);
+
+/**
+ * Callback to actually perform the data filtering
+ *
+ * Specified as `filter.apply`, this is the callback that actually filters
+ * data.  If it successfully writes the output, it should return 0.  Like
+ * `check`, it can return GIT_PASSTHROUGH to indicate that the filter
+ * doesn't want to run.  Other error codes will stop filter processing and
+ * return to the caller.
+ *
+ * The `payload` value will refer to any payload that was set by the
+ * `check` callback.  It may be read from or written to as needed.
+ */
+typedef int (*git_filter_apply_fn)(
+	git_filter    *self,
+	void         **payload, /* may be read and/or set */
+	git_buf       *to,
+	const git_buf *from,
+	const git_filter_source *src);
+
+typedef int (*git_filter_stream_fn)(
+	git_writestream **out,
+	git_filter *self,
+	void **payload,
+	const git_filter_source *src,
+	git_writestream *next);
+
+/**
+ * Callback to clean up after filtering has been applied
+ *
+ * Specified as `filter.cleanup`, this is an optional callback invoked
+ * after the filter has been applied.  If the `check` or `apply` callbacks
+ * allocated a `payload` to keep per-source filter state, use this
+ * callback to free that payload and release resources as required.
+ */
+typedef void (*git_filter_cleanup_fn)(
+	git_filter *self,
+	void       *payload);
+
+/**
+ * Filter structure used to register custom filters.
+ *
+ * To associate extra data with a filter, allocate extra data and put the
+ * `git_filter` struct at the start of your data buffer, then cast the
+ * `self` pointer to your larger structure when your callback is invoked.
+ */
+struct git_filter {
+	/** The `version` field should be set to `GIT_FILTER_VERSION`. */
+	unsigned int           version;
+
+ 	/**
+	 * A whitespace-separated list of attribute names to check for this
+	 * filter (e.g. "eol crlf text").  If the attribute name is bare, it
+	 * will be simply loaded and passed to the `check` callback.  If it
+	 * has a value (i.e. "name=value"), the attribute must match that
+	 * value for the filter to be applied.  The value may be a wildcard
+	 * (eg, "name=*"), in which case the filter will be invoked for any
+	 * value for the given attribute name.  See the attribute parameter
+	 * of the `check` callback for the attribute value that was specified.
+	 */
+	const char            *attributes;
+
+	/** Called when the filter is first used for any file. */
+	git_filter_init_fn     initialize;
+
+	/** Called when the filter is removed or unregistered from the system. */
+	git_filter_shutdown_fn shutdown;
+
+	/**
+	 * Called to determine whether the filter should be invoked for a
+	 * given file.  If this function returns `GIT_PASSTHROUGH` then the
+	 * `apply` function will not be invoked and the contents will be passed
+	 * through unmodified.
+	 */
+	git_filter_check_fn    check;
+
+	/**
+	 * Called to actually apply the filter to file contents.  If this
+	 * function returns `GIT_PASSTHROUGH` then the contents will be passed
+	 * through unmodified.
+	 */
+	git_filter_apply_fn    apply;
+
+	/**
+	 * Called to apply the filter in a streaming manner.  If this is not
+	 * specified then the system will call `apply` with the whole buffer.
+	 */
+	git_filter_stream_fn   stream;
+
+	/** Called when the system is done filtering for a file. */
+	git_filter_cleanup_fn  cleanup;
+};
+
+#define GIT_FILTER_VERSION 1
+#define GIT_FILTER_INIT {GIT_FILTER_VERSION}
+
+/**
+ * Initializes a `git_filter` with default values. Equivalent to
+ * creating an instance with GIT_FILTER_INIT.
+ *
+ * @param filter the `git_filter` struct to initialize.
+ * @param version Version the struct; pass `GIT_FILTER_VERSION`
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_filter_init(git_filter *filter, unsigned int version);
+
+/**
+ * Register a filter under a given name with a given priority.
+ *
+ * As mentioned elsewhere, the initialize callback will not be invoked
+ * immediately.  It is deferred until the filter is used in some way.
+ *
+ * A filter's attribute checks and `check` and `apply` callbacks will be
+ * issued in order of `priority` on smudge (to workdir), and in reverse
+ * order of `priority` on clean (to odb).
+ *
+ * Two filters are preregistered with libgit2:
+ * - GIT_FILTER_CRLF with priority 0
+ * - GIT_FILTER_IDENT with priority 100
+ *
+ * Currently the filter registry is not thread safe, so any registering or
+ * deregistering of filters must be done outside of any possible usage of
+ * the filters (i.e. during application setup or shutdown).
+ *
+ * @param name A name by which the filter can be referenced.  Attempting
+ * 			to register with an in-use name will return GIT_EEXISTS.
+ * @param filter The filter definition.  This pointer will be stored as is
+ * 			by libgit2 so it must be a durable allocation (either static
+ * 			or on the heap).
+ * @param priority The priority for filter application
+ * @return 0 on successful registry, error code <0 on failure
+ */
+GIT_EXTERN(int) git_filter_register(
+	const char *name, git_filter *filter, int priority);
+
+/**
+ * Remove the filter with the given name
+ *
+ * Attempting to remove the builtin libgit2 filters is not permitted and
+ * will return an error.
+ *
+ * Currently the filter registry is not thread safe, so any registering or
+ * deregistering of filters must be done outside of any possible usage of
+ * the filters (i.e. during application setup or shutdown).
+ *
+ * @param name The name under which the filter was registered
+ * @return 0 on success, error code <0 on failure
+ */
+GIT_EXTERN(int) git_filter_unregister(const char *name);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/sys/hashsig.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/sys/hashsig.h b/vendor/libgit2-sys/libgit2/include/git2/sys/hashsig.h
new file mode 100644
index 0000000..09c19ae
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/sys/hashsig.h
@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sys_hashsig_h__
+#define INCLUDE_sys_hashsig_h__
+
+#include "git2/common.h"
+
+GIT_BEGIN_DECL
+
+/**
+ * Similarity signature of arbitrary text content based on line hashes
+ */
+typedef struct git_hashsig git_hashsig;
+
+/**
+ * Options for hashsig computation
+ *
+ * The options GIT_HASHSIG_NORMAL, GIT_HASHSIG_IGNORE_WHITESPACE,
+ * GIT_HASHSIG_SMART_WHITESPACE are exclusive and should not be combined.
+ */
+typedef enum {
+	/**
+	 * Use all data
+	 */
+	GIT_HASHSIG_NORMAL = 0,
+
+	/**
+	 * Ignore whitespace
+	 */
+	GIT_HASHSIG_IGNORE_WHITESPACE = (1 << 0),
+
+	/**
+	 * Ignore \r and all space after \n
+	 */
+	GIT_HASHSIG_SMART_WHITESPACE = (1 << 1),
+
+	/**
+	 * Allow hashing of small files
+	 */
+	GIT_HASHSIG_ALLOW_SMALL_FILES = (1 << 2)
+} git_hashsig_option_t;
+
+/**
+ * Compute a similarity signature for a text buffer
+ *
+ * If you have passed the option GIT_HASHSIG_IGNORE_WHITESPACE, then the
+ * whitespace will be removed from the buffer while it is being processed,
+ * modifying the buffer in place. Sorry about that!
+ *
+ * @param out The computed similarity signature.
+ * @param buf The input buffer.
+ * @param buflen The input buffer size.
+ * @param opts The signature computation options (see above).
+ * @return 0 on success, GIT_EBUFS if the buffer doesn't contain enough data to
+ * compute a valid signature (unless GIT_HASHSIG_ALLOW_SMALL_FILES is set), or
+ * error code.
+ */
+GIT_EXTERN(int) git_hashsig_create(
+	git_hashsig **out,
+	const char *buf,
+	size_t buflen,
+	git_hashsig_option_t opts);
+
+/**
+ * Compute a similarity signature for a text file
+ *
+ * This walks through the file, only loading a maximum of 4K of file data at
+ * a time. Otherwise, it acts just like `git_hashsig_create`.
+ *
+ * @param out The computed similarity signature.
+ * @param path The path to the input file.
+ * @param opts The signature computation options (see above).
+ * @return 0 on success, GIT_EBUFS if the buffer doesn't contain enough data to
+ * compute a valid signature (unless GIT_HASHSIG_ALLOW_SMALL_FILES is set), or
+ * error code.
+ */
+GIT_EXTERN(int) git_hashsig_create_fromfile(
+	git_hashsig **out,
+	const char *path,
+	git_hashsig_option_t opts);
+
+/**
+ * Release memory for a content similarity signature
+ *
+ * @param sig The similarity signature to free.
+ */
+GIT_EXTERN(void) git_hashsig_free(git_hashsig *sig);
+
+/**
+ * Measure similarity score between two similarity signatures
+ *
+ * @param a The first similarity signature to compare.
+ * @param b The second similarity signature to compare.
+ * @return [0 to 100] on success as the similarity score, or error code.
+ */
+GIT_EXTERN(int) git_hashsig_compare(
+	const git_hashsig *a,
+	const git_hashsig *b);
+
+GIT_END_DECL
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/sys/index.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/sys/index.h b/vendor/libgit2-sys/libgit2/include/git2/sys/index.h
new file mode 100644
index 0000000..2e2b87e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/sys/index.h
@@ -0,0 +1,177 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sys_git_index_h__
+#define INCLUDE_sys_git_index_h__
+
+/**
+ * @file git2/sys/index.h
+ * @brief Low-level Git index manipulation routines
+ * @defgroup git_backend Git custom backend APIs
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/** Representation of a rename conflict entry in the index. */
+typedef struct git_index_name_entry {
+	char *ancestor;
+	char *ours;
+	char *theirs;
+} git_index_name_entry;
+
+/** Representation of a resolve undo entry in the index. */
+typedef struct git_index_reuc_entry {
+	uint32_t mode[3];
+	git_oid oid[3];
+	char *path;
+} git_index_reuc_entry;
+
+/** @name Conflict Name entry functions
+ *
+ * These functions work on rename conflict entries.
+ */
+/**@{*/
+
+/**
+ * Get the count of filename conflict entries currently in the index.
+ *
+ * @param index an existing index object
+ * @return integer of count of current filename conflict entries
+ */
+GIT_EXTERN(size_t) git_index_name_entrycount(git_index *index);
+
+/**
+ * Get a filename conflict entry from the index.
+ *
+ * The returned entry is read-only and should not be modified
+ * or freed by the caller.
+ *
+ * @param index an existing index object
+ * @param n the position of the entry
+ * @return a pointer to the filename conflict entry; NULL if out of bounds
+ */
+GIT_EXTERN(const git_index_name_entry *) git_index_name_get_byindex(
+	git_index *index, size_t n);
+
+/**
+ * Record the filenames involved in a rename conflict.
+ *
+ * @param index an existing index object
+ * @param ancestor the path of the file as it existed in the ancestor
+ * @param ours the path of the file as it existed in our tree
+ * @param theirs the path of the file as it existed in their tree
+ */
+GIT_EXTERN(int) git_index_name_add(git_index *index,
+	const char *ancestor, const char *ours, const char *theirs);
+
+/**
+ * Remove all filename conflict entries.
+ *
+ * @param index an existing index object
+ */
+GIT_EXTERN(void) git_index_name_clear(git_index *index);
+
+/**@}*/
+
+/** @name Resolve Undo (REUC) index entry manipulation.
+ *
+ * These functions work on the Resolve Undo index extension and contains
+ * data about the original files that led to a merge conflict.
+ */
+/**@{*/
+
+/**
+ * Get the count of resolve undo entries currently in the index.
+ *
+ * @param index an existing index object
+ * @return integer of count of current resolve undo entries
+ */
+GIT_EXTERN(size_t) git_index_reuc_entrycount(git_index *index);
+
+/**
+ * Finds the resolve undo entry that points to the given path in the Git
+ * index.
+ *
+ * @param at_pos the address to which the position of the reuc entry is written (optional)
+ * @param index an existing index object
+ * @param path path to search
+ * @return 0 if found, < 0 otherwise (GIT_ENOTFOUND)
+ */
+GIT_EXTERN(int) git_index_reuc_find(size_t *at_pos, git_index *index, const char *path);
+
+/**
+ * Get a resolve undo entry from the index.
+ *
+ * The returned entry is read-only and should not be modified
+ * or freed by the caller.
+ *
+ * @param index an existing index object
+ * @param path path to search
+ * @return the resolve undo entry; NULL if not found
+ */
+GIT_EXTERN(const git_index_reuc_entry *) git_index_reuc_get_bypath(git_index *index, const char *path);
+
+/**
+ * Get a resolve undo entry from the index.
+ *
+ * The returned entry is read-only and should not be modified
+ * or freed by the caller.
+ *
+ * @param index an existing index object
+ * @param n the position of the entry
+ * @return a pointer to the resolve undo entry; NULL if out of bounds
+ */
+GIT_EXTERN(const git_index_reuc_entry *) git_index_reuc_get_byindex(git_index *index, size_t n);
+
+/**
+ * Adds a resolve undo entry for a file based on the given parameters.
+ *
+ * The resolve undo entry contains the OIDs of files that were involved
+ * in a merge conflict after the conflict has been resolved.  This allows
+ * conflicts to be re-resolved later.
+ *
+ * If there exists a resolve undo entry for the given path in the index,
+ * it will be removed.
+ *
+ * This method will fail in bare index instances.
+ *
+ * @param index an existing index object
+ * @param path filename to add
+ * @param ancestor_mode mode of the ancestor file
+ * @param ancestor_id oid of the ancestor file
+ * @param our_mode mode of our file
+ * @param our_id oid of our file
+ * @param their_mode mode of their file
+ * @param their_id oid of their file
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_index_reuc_add(git_index *index, const char *path,
+	int ancestor_mode, const git_oid *ancestor_id,
+	int our_mode, const git_oid *our_id,
+	int their_mode, const git_oid *their_id);
+
+/**
+ * Remove an resolve undo entry from the index
+ *
+ * @param index an existing index object
+ * @param n position of the resolve undo entry to remove
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_index_reuc_remove(git_index *index, size_t n);
+
+/**
+ * Remove all resolve undo entries from the index
+ *
+ * @param index an existing index object
+ */
+GIT_EXTERN(void) git_index_reuc_clear(git_index *index);
+
+/**@}*/
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/sys/mempack.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/sys/mempack.h b/vendor/libgit2-sys/libgit2/include/git2/sys/mempack.h
new file mode 100644
index 0000000..490636b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/sys/mempack.h
@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sys_git_odb_mempack_h__
+#define INCLUDE_sys_git_odb_mempack_h__
+
+#include "git2/common.h"
+#include "git2/types.h"
+#include "git2/oid.h"
+#include "git2/odb.h"
+#include "git2/buffer.h"
+
+/**
+ * @file git2/sys/mempack.h
+ * @brief Custom ODB backend that permits packing objects in-memory
+ * @defgroup git_backend Git custom backend APIs
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ *	Instantiate a new mempack backend.
+ *
+ *	The backend must be added to an existing ODB with the highest
+ *	priority.
+ *
+ *		git_mempack_new(&mempacker);
+ *		git_repository_odb(&odb, repository);
+ *		git_odb_add_backend(odb, mempacker, 999);
+ *
+ *	Once the backend has been loaded, all writes to the ODB will
+ *	instead be queued in memory, and can be finalized with
+ *	`git_mempack_dump`.
+ *
+ *	Subsequent reads will also be served from the in-memory store
+ *	to ensure consistency, until the memory store is dumped.
+ *
+ *	@param out Pointer where to store the ODB backend
+ *	@return 0 on success; error code otherwise
+ */
+GIT_EXTERN(int) git_mempack_new(git_odb_backend **out);
+
+/**
+ *	Dump all the queued in-memory writes to a packfile.
+ *
+ *	The contents of the packfile will be stored in the given buffer.
+ *	It is the caller's responsibility to ensure that the generated
+ *	packfile is available to the repository (e.g. by writing it
+ *	to disk, or doing something crazy like distributing it across
+ *	several copies of the repository over a network).
+ *
+ *	Once the generated packfile is available to the repository,
+ *	call `git_mempack_reset` to cleanup the memory store.
+ *
+ *	Calling `git_mempack_reset` before the packfile has been
+ *	written to disk will result in an inconsistent repository
+ *	(the objects in the memory store won't be accessible).
+ *
+ *	@param pack Buffer where to store the raw packfile
+ *	@param repo The active repository where the backend is loaded
+ *	@param backend The mempack backend
+ *	@return 0 on success; error code otherwise
+ */
+GIT_EXTERN(int) git_mempack_dump(git_buf *pack, git_repository *repo, git_odb_backend *backend);
+
+/**
+ *	Reset the memory packer by clearing all the queued objects.
+ *
+ *	This assumes that `git_mempack_dump` has been called before to
+ *	store all the queued objects into a single packfile.
+ *
+ *	Alternatively, call `reset` without a previous dump to "undo"
+ *	all the recently written objects, giving transaction-like
+ *	semantics to the Git repository.
+ *
+ *	@param backend The mempack backend
+ */
+GIT_EXTERN(void) git_mempack_reset(git_odb_backend *backend);
+
+GIT_END_DECL
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/sys/merge.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/sys/merge.h b/vendor/libgit2-sys/libgit2/include/git2/sys/merge.h
new file mode 100644
index 0000000..eed106c
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/sys/merge.h
@@ -0,0 +1,177 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sys_git_merge_h__
+#define INCLUDE_sys_git_merge_h__
+
+/**
+ * @file git2/sys/merge.h
+ * @brief Git merge driver backend and plugin routines
+ * @defgroup git_backend Git custom backend APIs
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+typedef struct git_merge_driver git_merge_driver;
+
+/**
+ * Look up a merge driver by name
+ *
+ * @param name The name of the merge driver
+ * @return Pointer to the merge driver object or NULL if not found
+ */
+GIT_EXTERN(git_merge_driver *) git_merge_driver_lookup(const char *name);
+
+#define GIT_MERGE_DRIVER_TEXT   "text"
+#define GIT_MERGE_DRIVER_BINARY "binary"
+#define GIT_MERGE_DRIVER_UNION  "union"
+
+/**
+ * A merge driver source represents the file to be merged
+ */
+typedef struct git_merge_driver_source git_merge_driver_source;
+
+/** Get the repository that the source data is coming from. */
+GIT_EXTERN(const git_repository *) git_merge_driver_source_repo(
+	const git_merge_driver_source *src);
+
+/** Gets the ancestor of the file to merge. */
+GIT_EXTERN(const git_index_entry *) git_merge_driver_source_ancestor(
+	const git_merge_driver_source *src);
+
+/** Gets the ours side of the file to merge. */
+GIT_EXTERN(const git_index_entry *) git_merge_driver_source_ours(
+	const git_merge_driver_source *src);
+
+/** Gets the theirs side of the file to merge. */
+GIT_EXTERN(const git_index_entry *) git_merge_driver_source_theirs(
+	const git_merge_driver_source *src);
+
+/** Gets the merge file options that the merge was invoked with */
+GIT_EXTERN(const git_merge_file_options *) git_merge_driver_source_file_options(
+	const git_merge_driver_source *src);
+
+
+/**
+ * Initialize callback on merge driver
+ *
+ * Specified as `driver.initialize`, this is an optional callback invoked
+ * before a merge driver is first used.  It will be called once at most
+ * per library lifetime.
+ *
+ * If non-NULL, the merge driver's `initialize` callback will be invoked
+ * right before the first use of the driver, so you can defer expensive
+ * initialization operations (in case libgit2 is being used in a way that
+ * doesn't need the merge driver).
+ */
+typedef int (*git_merge_driver_init_fn)(git_merge_driver *self);
+
+/**
+ * Shutdown callback on merge driver
+ *
+ * Specified as `driver.shutdown`, this is an optional callback invoked
+ * when the merge driver is unregistered or when libgit2 is shutting down.
+ * It will be called once at most and should release resources as needed.
+ * This may be called even if the `initialize` callback was not made.
+ *
+ * Typically this function will free the `git_merge_driver` object itself.
+ */
+typedef void (*git_merge_driver_shutdown_fn)(git_merge_driver *self);
+
+/**
+ * Callback to perform the merge.
+ *
+ * Specified as `driver.apply`, this is the callback that actually does the
+ * merge.  If it can successfully perform a merge, it should populate
+ * `path_out` with a pointer to the filename to accept, `mode_out` with
+ * the resultant mode, and `merged_out` with the buffer of the merged file
+ * and then return 0.  If the driver returns `GIT_PASSTHROUGH`, then the
+ * default merge driver should instead be run.  It can also return
+ * `GIT_EMERGECONFLICT` if the driver is not able to produce a merge result,
+ * and the file will remain conflicted.  Any other errors will fail and
+ * return to the caller.
+ *
+ * The `filter_name` contains the name of the filter that was invoked, as
+ * specified by the file's attributes.
+ *
+ * The `src` contains the data about the file to be merged.
+ */
+typedef int (*git_merge_driver_apply_fn)(
+	git_merge_driver *self,
+	const char **path_out,
+	uint32_t *mode_out,
+	git_buf *merged_out,
+	const char *filter_name,
+	const git_merge_driver_source *src);
+
+/**
+ * Merge driver structure used to register custom merge drivers.
+ *
+ * To associate extra data with a driver, allocate extra data and put the
+ * `git_merge_driver` struct at the start of your data buffer, then cast
+ * the `self` pointer to your larger structure when your callback is invoked.
+ */
+struct git_merge_driver {
+	/** The `version` should be set to `GIT_MERGE_DRIVER_VERSION`. */
+	unsigned int                 version;
+
+	/** Called when the merge driver is first used for any file. */
+	git_merge_driver_init_fn     initialize;
+
+	/** Called when the merge driver is unregistered from the system. */
+	git_merge_driver_shutdown_fn shutdown;
+
+	/**
+	 * Called to merge the contents of a conflict.  If this function
+	 * returns `GIT_PASSTHROUGH` then the default (`text`) merge driver
+	 * will instead be invoked.  If this function returns
+	 * `GIT_EMERGECONFLICT` then the file will remain conflicted.
+	 */
+	git_merge_driver_apply_fn    apply;
+};
+
+#define GIT_MERGE_DRIVER_VERSION 1
+
+/**
+ * Register a merge driver under a given name.
+ *
+ * As mentioned elsewhere, the initialize callback will not be invoked
+ * immediately.  It is deferred until the driver is used in some way.
+ *
+ * Currently the merge driver registry is not thread safe, so any
+ * registering or deregistering of merge drivers must be done outside of
+ * any possible usage of the drivers (i.e. during application setup or
+ * shutdown).
+ *
+ * @param name The name of this driver to match an attribute.  Attempting
+ * 			to register with an in-use name will return GIT_EEXISTS.
+ * @param driver The merge driver definition.  This pointer will be stored
+ *			as is by libgit2 so it must be a durable allocation (either
+ *			static or on the heap).
+ * @return 0 on successful registry, error code <0 on failure
+ */
+GIT_EXTERN(int) git_merge_driver_register(
+	const char *name, git_merge_driver *driver);
+
+/**
+ * Remove the merge driver with the given name.
+ *
+ * Attempting to remove the builtin libgit2 merge drivers is not permitted
+ * and will return an error.
+ *
+ * Currently the merge driver registry is not thread safe, so any
+ * registering or deregistering of drivers must be done outside of any
+ * possible usage of the drivers (i.e. during application setup or shutdown).
+ *
+ * @param name The name under which the merge driver was registered
+ * @return 0 on success, error code <0 on failure
+ */
+GIT_EXTERN(int) git_merge_driver_unregister(const char *name);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/sys/odb_backend.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/sys/odb_backend.h b/vendor/libgit2-sys/libgit2/include/git2/sys/odb_backend.h
new file mode 100644
index 0000000..792f103
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/sys/odb_backend.h
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sys_git_odb_backend_h__
+#define INCLUDE_sys_git_odb_backend_h__
+
+#include "git2/common.h"
+#include "git2/types.h"
+#include "git2/oid.h"
+#include "git2/odb.h"
+
+/**
+ * @file git2/sys/backend.h
+ * @brief Git custom backend implementors functions
+ * @defgroup git_backend Git custom backend APIs
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * An instance for a custom backend
+ */
+struct git_odb_backend {
+	unsigned int version;
+	git_odb *odb;
+
+	/* read and read_prefix each return to libgit2 a buffer which
+	 * will be freed later. The buffer should be allocated using
+	 * the function git_odb_backend_malloc to ensure that it can
+	 * be safely freed later. */
+	int (* read)(
+		void **, size_t *, git_otype *, git_odb_backend *, const git_oid *);
+
+	/* To find a unique object given a prefix of its oid.  The oid given
+	 * must be so that the remaining (GIT_OID_HEXSZ - len)*4 bits are 0s.
+	 */
+	int (* read_prefix)(
+		git_oid *, void **, size_t *, git_otype *,
+		git_odb_backend *, const git_oid *, size_t);
+
+	int (* read_header)(
+		size_t *, git_otype *, git_odb_backend *, const git_oid *);
+
+	/**
+	 * Write an object into the backend. The id of the object has
+	 * already been calculated and is passed in.
+	 */
+	int (* write)(
+		git_odb_backend *, const git_oid *, const void *, size_t, git_otype);
+
+	int (* writestream)(
+		git_odb_stream **, git_odb_backend *, git_off_t, git_otype);
+
+	int (* readstream)(
+		git_odb_stream **, size_t *, git_otype *,
+		git_odb_backend *, const git_oid *);
+
+	int (* exists)(
+		git_odb_backend *, const git_oid *);
+
+	int (* exists_prefix)(
+		git_oid *, git_odb_backend *, const git_oid *, size_t);
+
+	/**
+	 * If the backend implements a refreshing mechanism, it should be exposed
+	 * through this endpoint. Each call to `git_odb_refresh()` will invoke it.
+	 *
+	 * However, the backend implementation should try to stay up-to-date as much
+	 * as possible by itself as libgit2 will not automatically invoke
+	 * `git_odb_refresh()`. For instance, a potential strategy for the backend
+	 * implementation to achieve this could be to internally invoke this
+	 * endpoint on failed lookups (ie. `exists()`, `read()`, `read_header()`).
+	 */
+	int (* refresh)(git_odb_backend *);
+
+	int (* foreach)(
+		git_odb_backend *, git_odb_foreach_cb cb, void *payload);
+
+	int (* writepack)(
+		git_odb_writepack **, git_odb_backend *, git_odb *odb,
+		git_transfer_progress_cb progress_cb, void *progress_payload);
+
+	/**
+	 * "Freshens" an already existing object, updating its last-used
+	 * time.  This occurs when `git_odb_write` was called, but the
+	 * object already existed (and will not be re-written).  The
+	 * underlying implementation may want to update last-used timestamps.
+	 *
+	 * If callers implement this, they should return `0` if the object
+	 * exists and was freshened, and non-zero otherwise.
+	 */
+	int (* freshen)(git_odb_backend *, const git_oid *);
+
+	/**
+	 * Frees any resources held by the odb (including the `git_odb_backend`
+	 * itself). An odb backend implementation must provide this function.
+	 */
+	void (* free)(git_odb_backend *);
+};
+
+#define GIT_ODB_BACKEND_VERSION 1
+#define GIT_ODB_BACKEND_INIT {GIT_ODB_BACKEND_VERSION}
+
+/**
+ * Initializes a `git_odb_backend` with default values. Equivalent to
+ * creating an instance with GIT_ODB_BACKEND_INIT.
+ *
+ * @param backend the `git_odb_backend` struct to initialize.
+ * @param version Version the struct; pass `GIT_ODB_BACKEND_VERSION`
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_odb_init_backend(
+	git_odb_backend *backend,
+	unsigned int version);
+
+GIT_EXTERN(void *) git_odb_backend_malloc(git_odb_backend *backend, size_t len);
+
+GIT_END_DECL
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/sys/openssl.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/sys/openssl.h b/vendor/libgit2-sys/libgit2/include/git2/sys/openssl.h
new file mode 100644
index 0000000..b41c55c
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/sys/openssl.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_openssl_h__
+#define INCLUDE_git_openssl_h__
+
+#include "git2/common.h"
+
+GIT_BEGIN_DECL
+
+/**
+ * Initialize the OpenSSL locks
+ *
+ * OpenSSL requires the application to determine how it performs
+ * locking.
+ *
+ * This is a last-resort convenience function which libgit2 provides for
+ * allocating and initializing the locks as well as setting the
+ * locking function to use the system's native locking functions.
+ *
+ * The locking function will be cleared and the memory will be freed
+ * when you call git_threads_sutdown().
+ *
+ * If your programming language has an OpenSSL package/bindings, it
+ * likely sets up locking. You should very strongly prefer that over
+ * this function.
+ *
+ * @return 0 on success, -1 if there are errors or if libgit2 was not
+ * built with OpenSSL and threading support.
+ */
+GIT_EXTERN(int) git_openssl_set_locking(void);
+
+GIT_END_DECL
+#endif
+

vendor/libgit2-sys/libgit2/include/git2/sys/refdb_backend.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/sys/refdb_backend.h b/vendor/libgit2-sys/libgit2/include/git2/sys/refdb_backend.h
new file mode 100644
index 0000000..5129ad8
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/sys/refdb_backend.h
@@ -0,0 +1,218 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sys_git_refdb_backend_h__
+#define INCLUDE_sys_git_refdb_backend_h__
+
+#include "git2/common.h"
+#include "git2/types.h"
+#include "git2/oid.h"
+
+/**
+ * @file git2/refdb_backend.h
+ * @brief Git custom refs backend functions
+ * @defgroup git_refdb_backend Git custom refs backend API
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+
+/**
+ * Every backend's iterator must have a pointer to itself as the first
+ * element, so the API can talk to it. You'd define your iterator as
+ *
+ *     struct my_iterator {
+ *             git_reference_iterator parent;
+ *             ...
+ *     }
+ *
+ * and assign `iter->parent.backend` to your `git_refdb_backend`.
+ */
+struct git_reference_iterator {
+	git_refdb *db;
+
+	/**
+	 * Return the current reference and advance the iterator.
+	 */
+	int (*next)(
+		git_reference **ref,
+		git_reference_iterator *iter);
+
+	/**
+	 * Return the name of the current reference and advance the iterator
+	 */
+	int (*next_name)(
+		const char **ref_name,
+		git_reference_iterator *iter);
+
+	/**
+	 * Free the iterator
+	 */
+	void (*free)(
+		git_reference_iterator *iter);
+};
+
+/** An instance for a custom backend */
+struct git_refdb_backend {
+	unsigned int version;
+
+	/**
+	 * Queries the refdb backend to determine if the given ref_name
+	 * exists.  A refdb implementation must provide this function.
+	 */
+	int (*exists)(
+		int *exists,
+		git_refdb_backend *backend,
+		const char *ref_name);
+
+	/**
+	 * Queries the refdb backend for a given reference.  A refdb
+	 * implementation must provide this function.
+	 */
+	int (*lookup)(
+		git_reference **out,
+		git_refdb_backend *backend,
+		const char *ref_name);
+
+	/**
+	 * Allocate an iterator object for the backend.
+	 *
+	 * A refdb implementation must provide this function.
+	 */
+	int (*iterator)(
+		git_reference_iterator **iter,
+		struct git_refdb_backend *backend,
+		const char *glob);
+
+	/*
+	 * Writes the given reference to the refdb.  A refdb implementation
+	 * must provide this function.
+	 */
+	int (*write)(git_refdb_backend *backend,
+		     const git_reference *ref, int force,
+		     const git_signature *who, const char *message,
+		     const git_oid *old, const char *old_target);
+
+	int (*rename)(
+		git_reference **out, git_refdb_backend *backend,
+		const char *old_name, const char *new_name, int force,
+		const git_signature *who, const char *message);
+
+	/**
+	 * Deletes the given reference (and if necessary its reflog)
+	 * from the refdb.  A refdb implementation must provide this
+	 * function.
+	 */
+	int (*del)(git_refdb_backend *backend, const char *ref_name, const git_oid *old_id, const char *old_target);
+
+	/**
+	 * Suggests that the given refdb compress or optimize its references.
+	 * This mechanism is implementation specific.  (For on-disk reference
+	 * databases, this may pack all loose references.)    A refdb
+	 * implementation may provide this function; if it is not provided,
+	 * nothing will be done.
+	 */
+	int (*compress)(git_refdb_backend *backend);
+
+	/**
+	 * Query whether a particular reference has a log (may be empty)
+	 */
+	int (*has_log)(git_refdb_backend *backend, const char *refname);
+
+	/**
+	 * Make sure a particular reference will have a reflog which
+	 * will be appended to on writes.
+	 */
+	int (*ensure_log)(git_refdb_backend *backend, const char *refname);
+
+	/**
+	 * Frees any resources held by the refdb (including the `git_refdb_backend`
+	 * itself). A refdb backend implementation must provide this function.
+	 */
+	void (*free)(git_refdb_backend *backend);
+
+	/**
+	 * Read the reflog for the given reference name.
+	 */
+	int (*reflog_read)(git_reflog **out, git_refdb_backend *backend, const char *name);
+
+	/**
+	 * Write a reflog to disk.
+	 */
+	int (*reflog_write)(git_refdb_backend *backend, git_reflog *reflog);
+
+	/**
+	 * Rename a reflog
+	 */
+	int (*reflog_rename)(git_refdb_backend *_backend, const char *old_name, const char *new_name);
+
+	/**
+	 * Remove a reflog.
+	 */
+	int (*reflog_delete)(git_refdb_backend *backend, const char *name);
+
+	/**
+	 * Lock a reference. The opaque parameter will be passed to the unlock function
+	 */
+	int (*lock)(void **payload_out, git_refdb_backend *backend, const char *refname);
+
+	/**
+	 * Unlock a reference. Only one of target or symbolic_target
+	 * will be set. success indicates whether to update the
+	 * reference or discard the lock (if it's false)
+	 */
+	int (*unlock)(git_refdb_backend *backend, void *payload, int success, int update_reflog,
+		      const git_reference *ref, const git_signature *sig, const char *message);
+};
+
+#define GIT_REFDB_BACKEND_VERSION 1
+#define GIT_REFDB_BACKEND_INIT {GIT_REFDB_BACKEND_VERSION}
+
+/**
+ * Initializes a `git_refdb_backend` with default values. Equivalent to
+ * creating an instance with GIT_REFDB_BACKEND_INIT.
+ *
+ * @param backend the `git_refdb_backend` struct to initialize
+ * @param version Version of struct; pass `GIT_REFDB_BACKEND_VERSION`
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_refdb_init_backend(
+	git_refdb_backend *backend,
+	unsigned int version);
+
+/**
+ * Constructors for default filesystem-based refdb backend
+ *
+ * Under normal usage, this is called for you when the repository is
+ * opened / created, but you can use this to explicitly construct a
+ * filesystem refdb backend for a repository.
+ *
+ * @param backend_out Output pointer to the git_refdb_backend object
+ * @param repo Git repository to access
+ * @return 0 on success, <0 error code on failure
+ */
+GIT_EXTERN(int) git_refdb_backend_fs(
+	git_refdb_backend **backend_out,
+	git_repository *repo);
+
+/**
+ * Sets the custom backend to an existing reference DB
+ *
+ * The `git_refdb` will take ownership of the `git_refdb_backend` so you
+ * should NOT free it after calling this function.
+ *
+ * @param refdb database to add the backend to
+ * @param backend pointer to a git_refdb_backend instance
+ * @return 0 on success; error code otherwise
+ */
+GIT_EXTERN(int) git_refdb_set_backend(
+	git_refdb *refdb,
+	git_refdb_backend *backend);
+
+GIT_END_DECL
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/sys/reflog.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/sys/reflog.h b/vendor/libgit2-sys/libgit2/include/git2/sys/reflog.h
new file mode 100644
index 0000000..c9d0041
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/sys/reflog.h
@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sys_git_reflog_h__
+#define INCLUDE_sys_git_reflog_h__
+
+#include "git2/common.h"
+#include "git2/types.h"
+#include "git2/oid.h"
+
+GIT_BEGIN_DECL
+
+GIT_EXTERN(git_reflog_entry *) git_reflog_entry__alloc(void);
+GIT_EXTERN(void) git_reflog_entry__free(git_reflog_entry *entry);
+
+GIT_END_DECL
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/sys/refs.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/sys/refs.h b/vendor/libgit2-sys/libgit2/include/git2/sys/refs.h
new file mode 100644
index 0000000..d2ce2e0
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/sys/refs.h
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sys_git_refdb_h__
+#define INCLUDE_sys_git_refdb_h__
+
+#include "git2/common.h"
+#include "git2/types.h"
+#include "git2/oid.h"
+
+/**
+ * @file git2/sys/refs.h
+ * @brief Low-level Git ref creation
+ * @defgroup git_backend Git custom backend APIs
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Create a new direct reference from an OID.
+ *
+ * @param name the reference name
+ * @param oid the object id for a direct reference
+ * @param peel the first non-tag object's OID, or NULL
+ * @return the created git_reference or NULL on error
+ */
+GIT_EXTERN(git_reference *) git_reference__alloc(
+	const char *name,
+	const git_oid *oid,
+	const git_oid *peel);
+
+/**
+ * Create a new symbolic reference.
+ *
+ * @param name the reference name
+ * @param target the target for a symbolic reference
+ * @return the created git_reference or NULL on error
+ */
+GIT_EXTERN(git_reference *) git_reference__alloc_symbolic(
+	const char *name,
+	const char *target);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/sys/repository.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/sys/repository.h b/vendor/libgit2-sys/libgit2/include/git2/sys/repository.h
new file mode 100644
index 0000000..0c91421
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/sys/repository.h
@@ -0,0 +1,169 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sys_git_repository_h__
+#define INCLUDE_sys_git_repository_h__
+
+#include "git2/common.h"
+#include "git2/types.h"
+
+/**
+ * @file git2/sys/repository.h
+ * @brief Git repository custom implementation routines
+ * @defgroup git_backend Git custom backend APIs
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Create a new repository with neither backends nor config object
+ *
+ * Note that this is only useful if you wish to associate the repository
+ * with a non-filesystem-backed object database and config store.
+ *
+ * @param out The blank repository
+ * @return 0 on success, or an error code
+ */
+GIT_EXTERN(int) git_repository_new(git_repository **out);
+
+/**
+ * Reset all the internal state in a repository.
+ *
+ * This will free all the mapped memory and internal objects
+ * of the repository and leave it in a "blank" state.
+ *
+ * There's no need to call this function directly unless you're
+ * trying to aggressively cleanup the repo before its
+ * deallocation. `git_repository_free` already performs this operation
+ * before deallocation the repo.
+ */
+GIT_EXTERN(void) git_repository__cleanup(git_repository *repo);
+
+/**
+ * Update the filesystem config settings for an open repository
+ *
+ * When a repository is initialized, config values are set based on the
+ * properties of the filesystem that the repository is on, such as
+ * "core.ignorecase", "core.filemode", "core.symlinks", etc.  If the
+ * repository is moved to a new filesystem, these properties may no
+ * longer be correct and API calls may not behave as expected.  This
+ * call reruns the phase of repository initialization that sets those
+ * properties to compensate for the current filesystem of the repo.
+ *
+ * @param repo A repository object
+ * @param recurse_submodules Should submodules be updated recursively
+ * @return 0 on success, < 0 on error
+ */
+GIT_EXTERN(int) git_repository_reinit_filesystem(
+	git_repository *repo,
+	int recurse_submodules);
+
+/**
+ * Set the configuration file for this repository
+ *
+ * This configuration file will be used for all configuration
+ * queries involving this repository.
+ *
+ * The repository will keep a reference to the config file;
+ * the user must still free the config after setting it
+ * to the repository, or it will leak.
+ *
+ * @param repo A repository object
+ * @param config A Config object
+ */
+GIT_EXTERN(void) git_repository_set_config(git_repository *repo, git_config *config);
+
+/**
+ * Set the Object Database for this repository
+ *
+ * The ODB will be used for all object-related operations
+ * involving this repository.
+ *
+ * The repository will keep a reference to the ODB; the user
+ * must still free the ODB object after setting it to the
+ * repository, or it will leak.
+ *
+ * @param repo A repository object
+ * @param odb An ODB object
+ */
+GIT_EXTERN(void) git_repository_set_odb(git_repository *repo, git_odb *odb);
+
+/**
+ * Set the Reference Database Backend for this repository
+ *
+ * The refdb will be used for all reference related operations
+ * involving this repository.
+ *
+ * The repository will keep a reference to the refdb; the user
+ * must still free the refdb object after setting it to the
+ * repository, or it will leak.
+ *
+ * @param repo A repository object
+ * @param refdb An refdb object
+ */
+GIT_EXTERN(void) git_repository_set_refdb(git_repository *repo, git_refdb *refdb);
+
+/**
+ * Set the index file for this repository
+ *
+ * This index will be used for all index-related operations
+ * involving this repository.
+ *
+ * The repository will keep a reference to the index file;
+ * the user must still free the index after setting it
+ * to the repository, or it will leak.
+ *
+ * @param repo A repository object
+ * @param index An index object
+ */
+GIT_EXTERN(void) git_repository_set_index(git_repository *repo, git_index *index);
+
+/**
+ * Set a repository to be bare.
+ *
+ * Clear the working directory and set core.bare to true.  You may also
+ * want to call `git_repository_set_index(repo, NULL)` since a bare repo
+ * typically does not have an index, but this function will not do that
+ * for you.
+ *
+ * @param repo Repo to make bare
+ * @return 0 on success, <0 on failure
+ */
+GIT_EXTERN(int) git_repository_set_bare(git_repository *repo);
+
+/**
+ * Load and cache all submodules.
+ *
+ * Because the `.gitmodules` file is unstructured, loading submodules is an
+ * O(N) operation.  Any operation (such as `git_rebase_init`) that requires
+ * accessing all submodules is O(N^2) in the number of submodules, if it
+ * has to look each one up individually.  This function loads all submodules
+ * and caches them so that subsequent calls to `git_submodule_lookup` are O(1).
+ *
+ * @param repo the repository whose submodules will be cached.
+ */
+GIT_EXTERN(int) git_repository_submodule_cache_all(
+	git_repository *repo);
+
+/**
+ * Clear the submodule cache.
+ *
+ * Clear the submodule cache populated by `git_repository_submodule_cache_all`.
+ * If there is no cache, do nothing.
+ *
+ * The cache incorporates data from the repository's configuration, as well
+ * as the state of the working tree, the index, and HEAD.  So any time any
+ * of these has changed, the cache might become invalid.
+ *
+ * @param repo the repository whose submodule cache will be cleared
+ */
+GIT_EXTERN(int) git_repository_submodule_cache_clear(
+	git_repository *repo);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/sys/stream.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/sys/stream.h b/vendor/libgit2-sys/libgit2/include/git2/sys/stream.h
new file mode 100644
index 0000000..eeeb68d
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/sys/stream.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sys_git_stream_h__
+#define INCLUDE_sys_git_stream_h__
+
+#include "git2/common.h"
+#include "git2/types.h"
+#include "git2/proxy.h"
+
+GIT_BEGIN_DECL
+
+#define GIT_STREAM_VERSION 1
+
+/**
+ * Every stream must have this struct as its first element, so the
+ * API can talk to it. You'd define your stream as
+ *
+ *     struct my_stream {
+ *             git_stream parent;
+ *             ...
+ *     }
+ *
+ * and fill the functions
+ */
+typedef struct git_stream {
+	int version;
+
+	int encrypted;
+	int proxy_support;
+	int (*connect)(struct git_stream *);
+	int (*certificate)(git_cert **, struct git_stream *);
+	int (*set_proxy)(struct git_stream *, const git_proxy_options *proxy_opts);
+	ssize_t (*read)(struct git_stream *, void *, size_t);
+	ssize_t (*write)(struct git_stream *, const char *, size_t, int);
+	int (*close)(struct git_stream *);
+	void (*free)(struct git_stream *);
+} git_stream;
+
+typedef int (*git_stream_cb)(git_stream **out, const char *host, const char *port);
+
+/**
+ * Register a TLS stream constructor for the library to use
+ *
+ * If a constructor is already set, it will be overwritten. Pass
+ * `NULL` in order to deregister the current constructor.
+ *
+ * @param ctor the constructor to use
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_stream_register_tls(git_stream_cb ctor);
+
+GIT_END_DECL
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/sys/time.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/sys/time.h b/vendor/libgit2-sys/libgit2/include/git2/sys/time.h
new file mode 100644
index 0000000..e4f87e6
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/sys/time.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_time_h__
+#define INCLUDE_git_time_h__
+
+#include "git2/common.h"
+
+GIT_BEGIN_DECL
+
+/**
+ * Return a monotonic time value, useful for measuring running time
+ * and setting up timeouts.
+ *
+ * The returned value is an arbitrary point in time -- it can only be
+ * used when comparing it to another `git_time_monotonic` call.
+ *
+ * The time is returned in seconds, with a decimal fraction that differs
+ * on accuracy based on the underlying system, but should be least
+ * accurate to Nanoseconds.
+ *
+ * This function cannot fail.
+ */
+GIT_EXTERN(double) git_time_monotonic(void);
+
+GIT_END_DECL
+#endif
+

vendor/libgit2-sys/libgit2/include/git2/sys/transport.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/sys/transport.h b/vendor/libgit2-sys/libgit2/include/git2/sys/transport.h
new file mode 100644
index 0000000..a395de5
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/sys/transport.h
@@ -0,0 +1,393 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_sys_git_transport_h
+#define INCLUDE_sys_git_transport_h
+
+#include "git2/net.h"
+#include "git2/types.h"
+#include "git2/strarray.h"
+#include "git2/proxy.h"
+
+/**
+ * @file git2/sys/transport.h
+ * @brief Git custom transport registration interfaces and functions
+ * @defgroup git_transport Git custom transport registration
+ * @ingroup Git
+ * @{
+ */
+
+GIT_BEGIN_DECL
+
+/**
+ * Flags to pass to transport
+ *
+ * Currently unused.
+ */
+typedef enum {
+	GIT_TRANSPORTFLAGS_NONE = 0,
+} git_transport_flags_t;
+
+struct git_transport {
+	unsigned int version;
+	/* Set progress and error callbacks */
+	int (*set_callbacks)(
+		git_transport *transport,
+		git_transport_message_cb progress_cb,
+		git_transport_message_cb error_cb,
+		git_transport_certificate_check_cb certificate_check_cb,
+		void *payload);
+
+	/* Set custom headers for HTTP requests */
+	int (*set_custom_headers)(
+		git_transport *transport,
+		const git_strarray *custom_headers);
+
+	/* Connect the transport to the remote repository, using the given
+	 * direction. */
+	int (*connect)(
+		git_transport *transport,
+		const char *url,
+		git_cred_acquire_cb cred_acquire_cb,
+		void *cred_acquire_payload,
+		const git_proxy_options *proxy_opts,
+		int direction,
+		int flags);
+
+	/* This function may be called after a successful call to
+	 * connect(). The array returned is owned by the transport and
+	 * is guaranteed until the next call of a transport function. */
+	int (*ls)(
+		const git_remote_head ***out,
+		size_t *size,
+		git_transport *transport);
+
+	/* Executes the push whose context is in the git_push object. */
+	int(*push)(git_transport *transport, git_push *push, const git_remote_callbacks *callbacks);
+
+	/* This function may be called after a successful call to connect(), when
+	 * the direction is FETCH. The function performs a negotiation to calculate
+	 * the wants list for the fetch. */
+	int (*negotiate_fetch)(
+		git_transport *transport,
+		git_repository *repo,
+		const git_remote_head * const *refs,
+		size_t count);
+
+	/* This function may be called after a successful call to negotiate_fetch(),
+	 * when the direction is FETCH. This function retrieves the pack file for
+	 * the fetch from the remote end. */
+	int (*download_pack)(
+		git_transport *transport,
+		git_repository *repo,
+		git_transfer_progress *stats,
+		git_transfer_progress_cb progress_cb,
+		void *progress_payload);
+
+	/* Checks to see if the transport is connected */
+	int (*is_connected)(git_transport *transport);
+
+	/* Reads the flags value previously passed into connect() */
+	int (*read_flags)(git_transport *transport, int *flags);
+
+	/* Cancels any outstanding transport operation */
+	void (*cancel)(git_transport *transport);
+
+	/* This function is the reverse of connect() -- it terminates the
+	 * connection to the remote end. */
+	int (*close)(git_transport *transport);
+
+	/* Frees/destructs the git_transport object. */
+	void (*free)(git_transport *transport);
+};
+
+#define GIT_TRANSPORT_VERSION 1
+#define GIT_TRANSPORT_INIT {GIT_TRANSPORT_VERSION}
+
+/**
+ * Initializes a `git_transport` with default values. Equivalent to
+ * creating an instance with GIT_TRANSPORT_INIT.
+ *
+ * @param opts the `git_transport` struct to initialize
+ * @param version Version of struct; pass `GIT_TRANSPORT_VERSION`
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_transport_init(
+	git_transport *opts,
+	unsigned int version);
+
+/**
+ * Function to use to create a transport from a URL. The transport database
+ * is scanned to find a transport that implements the scheme of the URI (i.e.
+ * git:// or http://) and a transport object is returned to the caller.
+ *
+ * @param out The newly created transport (out)
+ * @param owner The git_remote which will own this transport
+ * @param url The URL to connect to
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_transport_new(git_transport **out, git_remote *owner, const char *url);
+
+/**
+ * Create an ssh transport with custom git command paths
+ *
+ * This is a factory function suitable for setting as the transport
+ * callback in a remote (or for a clone in the options).
+ *
+ * The payload argument must be a strarray pointer with the paths for
+ * the `git-upload-pack` and `git-receive-pack` at index 0 and 1.
+ *
+ * @param out the resulting transport
+ * @param owner the owning remote
+ * @param payload a strarray with the paths
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_transport_ssh_with_paths(git_transport **out, git_remote *owner, void *payload);
+
+/**
+ * Add a custom transport definition, to be used in addition to the built-in
+ * set of transports that come with libgit2.
+ *
+ * The caller is responsible for synchronizing calls to git_transport_register
+ * and git_transport_unregister with other calls to the library that
+ * instantiate transports.
+ *
+ * @param prefix The scheme (ending in "://") to match, i.e. "git://"
+ * @param cb The callback used to create an instance of the transport
+ * @param param A fixed parameter to pass to cb at creation time
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_transport_register(
+	const char *prefix,
+	git_transport_cb cb,
+	void *param);
+
+/**
+ *
+ * Unregister a custom transport definition which was previously registered
+ * with git_transport_register.
+ *
+ * @param prefix From the previous call to git_transport_register
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_transport_unregister(
+	const char *prefix);
+
+/* Transports which come with libgit2 (match git_transport_cb). The expected
+ * value for "param" is listed in-line below. */
+
+/**
+ * Create an instance of the dummy transport.
+ *
+ * @param out The newly created transport (out)
+ * @param owner The git_remote which will own this transport
+ * @param payload You must pass NULL for this parameter.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_transport_dummy(
+	git_transport **out,
+	git_remote *owner,
+	/* NULL */ void *payload);
+
+/**
+ * Create an instance of the local transport.
+ *
+ * @param out The newly created transport (out)
+ * @param owner The git_remote which will own this transport
+ * @param payload You must pass NULL for this parameter.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_transport_local(
+	git_transport **out,
+	git_remote *owner,
+	/* NULL */ void *payload);
+
+/**
+ * Create an instance of the smart transport.
+ *
+ * @param out The newly created transport (out)
+ * @param owner The git_remote which will own this transport
+ * @param payload A pointer to a git_smart_subtransport_definition
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_transport_smart(
+	git_transport **out,
+	git_remote *owner,
+	/* (git_smart_subtransport_definition *) */ void *payload);
+
+/**
+ * Call the certificate check for this transport.
+ *
+ * @param transport a smart transport
+ * @param cert the certificate to pass to the caller
+ * @param valid whether we believe the certificate is valid
+ * @param hostname the hostname we connected to
+ * @return the return value of the callback
+ */
+GIT_EXTERN(int) git_transport_smart_certificate_check(git_transport *transport, git_cert *cert, int valid, const char *hostname);
+
+/**
+ * Call the credentials callback for this transport
+ *
+ * @param out the pointer where the creds are to be stored
+ * @param transport a smart transport
+ * @param user the user we saw on the url (if any)
+ * @param methods available methods for authentication
+ * @return the return value of the callback
+ */
+GIT_EXTERN(int) git_transport_smart_credentials(git_cred **out, git_transport *transport, const char *user, int methods);
+
+/**
+ * Get a copy of the proxy options
+ *
+ * The url is copied and must be freed by the caller.
+ *
+ * @param out options struct to fill
+ * @param transport the transport to extract the data from.
+ */
+GIT_EXTERN(int) git_transport_smart_proxy_options(git_proxy_options *out, git_transport *transport);
+
+/*
+ *** End of base transport interface ***
+ *** Begin interface for subtransports for the smart transport ***
+ */
+
+/* The smart transport knows how to speak the git protocol, but it has no
+ * knowledge of how to establish a connection between it and another endpoint,
+ * or how to move data back and forth. For this, a subtransport interface is
+ * declared, and the smart transport delegates this work to the subtransports.
+ * Three subtransports are implemented: git, http, and winhttp. (The http and
+ * winhttp transports each implement both http and https.) */
+
+/* Subtransports can either be RPC = 0 (persistent connection) or RPC = 1
+ * (request/response). The smart transport handles the differences in its own
+ * logic. The git subtransport is RPC = 0, while http and winhttp are both
+ * RPC = 1. */
+
+/* Actions that the smart transport can ask
+ * a subtransport to perform */
+typedef enum {
+	GIT_SERVICE_UPLOADPACK_LS = 1,
+	GIT_SERVICE_UPLOADPACK = 2,
+	GIT_SERVICE_RECEIVEPACK_LS = 3,
+	GIT_SERVICE_RECEIVEPACK = 4,
+} git_smart_service_t;
+
+typedef struct git_smart_subtransport git_smart_subtransport;
+typedef struct git_smart_subtransport_stream git_smart_subtransport_stream;
+
+/* A stream used by the smart transport to read and write data
+ * from a subtransport */
+struct git_smart_subtransport_stream {
+	/* The owning subtransport */
+	git_smart_subtransport *subtransport;
+
+	int (*read)(
+		git_smart_subtransport_stream *stream,
+		char *buffer,
+		size_t buf_size,
+		size_t *bytes_read);
+
+	int (*write)(
+		git_smart_subtransport_stream *stream,
+		const char *buffer,
+		size_t len);
+
+	void (*free)(
+		git_smart_subtransport_stream *stream);
+};
+
+/* An implementation of a subtransport which carries data for the
+ * smart transport */
+struct git_smart_subtransport {
+	int (* action)(
+			git_smart_subtransport_stream **out,
+			git_smart_subtransport *transport,
+			const char *url,
+			git_smart_service_t action);
+
+	/* Subtransports are guaranteed a call to close() between
+	 * calls to action(), except for the following two "natural" progressions
+	 * of actions against a constant URL.
+	 *
+	 * 1. UPLOADPACK_LS -> UPLOADPACK
+	 * 2. RECEIVEPACK_LS -> RECEIVEPACK */
+	int (*close)(git_smart_subtransport *transport);
+
+	void (*free)(git_smart_subtransport *transport);
+};
+
+/* A function which creates a new subtransport for the smart transport */
+typedef int (*git_smart_subtransport_cb)(
+	git_smart_subtransport **out,
+	git_transport* owner,
+	void* param);
+
+/**
+ * Definition for a "subtransport"
+ *
+ * This is used to let the smart protocol code know about the protocol
+ * which you are implementing.
+ */
+typedef struct git_smart_subtransport_definition {
+	/** The function to use to create the git_smart_subtransport */
+	git_smart_subtransport_cb callback;
+
+	/**
+	 * True if the protocol is stateless; false otherwise. For example,
+	 * http:// is stateless, but git:// is not.
+	 */
+	unsigned rpc;
+
+	/** Param of the callback
+	 */
+	void* param;
+} git_smart_subtransport_definition;
+
+/* Smart transport subtransports that come with libgit2 */
+
+/**
+ * Create an instance of the http subtransport. This subtransport
+ * also supports https. On Win32, this subtransport may be implemented
+ * using the WinHTTP library.
+ *
+ * @param out The newly created subtransport
+ * @param owner The smart transport to own this subtransport
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_smart_subtransport_http(
+	git_smart_subtransport **out,
+	git_transport* owner,
+	void *param);
+
+/**
+ * Create an instance of the git subtransport.
+ *
+ * @param out The newly created subtransport
+ * @param owner The smart transport to own this subtransport
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_smart_subtransport_git(
+	git_smart_subtransport **out,
+	git_transport* owner,
+	void *param);
+
+/**
+ * Create an instance of the ssh subtransport.
+ *
+ * @param out The newly created subtransport
+ * @param owner The smart transport to own this subtransport
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_smart_subtransport_ssh(
+	git_smart_subtransport **out,
+	git_transport* owner,
+	void *param);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/tag.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/tag.h b/vendor/libgit2-sys/libgit2/include/git2/tag.h
new file mode 100644
index 0000000..cb95fb5
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/tag.h
@@ -0,0 +1,361 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_tag_h__
+#define INCLUDE_git_tag_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+#include "object.h"
+#include "strarray.h"
+
+/**
+ * @file git2/tag.h
+ * @brief Git tag parsing routines
+ * @defgroup git_tag Git tag management
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Lookup a tag object from the repository.
+ *
+ * @param out pointer to the looked up tag
+ * @param repo the repo to use when locating the tag.
+ * @param id identity of the tag to locate.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_tag_lookup(
+	git_tag **out, git_repository *repo, const git_oid *id);
+
+/**
+ * Lookup a tag object from the repository,
+ * given a prefix of its identifier (short id).
+ *
+ * @see git_object_lookup_prefix
+ *
+ * @param out pointer to the looked up tag
+ * @param repo the repo to use when locating the tag.
+ * @param id identity of the tag to locate.
+ * @param len the length of the short identifier
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_tag_lookup_prefix(
+	git_tag **out, git_repository *repo, const git_oid *id, size_t len);
+
+/**
+ * Close an open tag
+ *
+ * You can no longer use the git_tag pointer after this call.
+ *
+ * IMPORTANT: You MUST call this method when you are through with a tag to
+ * release memory. Failure to do so will cause a memory leak.
+ *
+ * @param tag the tag to close
+ */
+GIT_EXTERN(void) git_tag_free(git_tag *tag);
+
+/**
+ * Get the id of a tag.
+ *
+ * @param tag a previously loaded tag.
+ * @return object identity for the tag.
+ */
+GIT_EXTERN(const git_oid *) git_tag_id(const git_tag *tag);
+
+/**
+ * Get the repository that contains the tag.
+ *
+ * @param tag A previously loaded tag.
+ * @return Repository that contains this tag.
+ */
+GIT_EXTERN(git_repository *) git_tag_owner(const git_tag *tag);
+
+/**
+ * Get the tagged object of a tag
+ *
+ * This method performs a repository lookup for the
+ * given object and returns it
+ *
+ * @param target_out pointer where to store the target
+ * @param tag a previously loaded tag.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_tag_target(git_object **target_out, const git_tag *tag);
+
+/**
+ * Get the OID of the tagged object of a tag
+ *
+ * @param tag a previously loaded tag.
+ * @return pointer to the OID
+ */
+GIT_EXTERN(const git_oid *) git_tag_target_id(const git_tag *tag);
+
+/**
+ * Get the type of a tag's tagged object
+ *
+ * @param tag a previously loaded tag.
+ * @return type of the tagged object
+ */
+GIT_EXTERN(git_otype) git_tag_target_type(const git_tag *tag);
+
+/**
+ * Get the name of a tag
+ *
+ * @param tag a previously loaded tag.
+ * @return name of the tag
+ */
+GIT_EXTERN(const char *) git_tag_name(const git_tag *tag);
+
+/**
+ * Get the tagger (author) of a tag
+ *
+ * @param tag a previously loaded tag.
+ * @return reference to the tag's author or NULL when unspecified
+ */
+GIT_EXTERN(const git_signature *) git_tag_tagger(const git_tag *tag);
+
+/**
+ * Get the message of a tag
+ *
+ * @param tag a previously loaded tag.
+ * @return message of the tag or NULL when unspecified
+ */
+GIT_EXTERN(const char *) git_tag_message(const git_tag *tag);
+
+
+/**
+ * Create a new tag in the repository from an object
+ *
+ * A new reference will also be created pointing to
+ * this tag object. If `force` is true and a reference
+ * already exists with the given name, it'll be replaced.
+ *
+ * The message will not be cleaned up. This can be achieved
+ * through `git_message_prettify()`.
+ *
+ * The tag name will be checked for validity. You must avoid
+ * the characters '~', '^', ':', '\\', '?', '[', and '*', and the
+ * sequences ".." and "@{" which have special meaning to revparse.
+ *
+ * @param oid Pointer where to store the OID of the
+ * newly created tag. If the tag already exists, this parameter
+ * will be the oid of the existing tag, and the function will
+ * return a GIT_EEXISTS error code.
+ *
+ * @param repo Repository where to store the tag
+ *
+ * @param tag_name Name for the tag; this name is validated
+ * for consistency. It should also not conflict with an
+ * already existing tag name
+ *
+ * @param target Object to which this tag points. This object
+ * must belong to the given `repo`.
+ *
+ * @param tagger Signature of the tagger for this tag, and
+ * of the tagging time
+ *
+ * @param message Full message for this tag
+ *
+ * @param force Overwrite existing references
+ *
+ * @return 0 on success, GIT_EINVALIDSPEC or an error code
+ *	A tag object is written to the ODB, and a proper reference
+ *	is written in the /refs/tags folder, pointing to it
+ */
+GIT_EXTERN(int) git_tag_create(
+	git_oid *oid,
+	git_repository *repo,
+	const char *tag_name,
+	const git_object *target,
+	const git_signature *tagger,
+	const char *message,
+	int force);
+
+/**
+ * Create a new tag in the object database pointing to a git_object
+ *
+ * The message will not be cleaned up. This can be achieved
+ * through `git_message_prettify()`.
+ *
+ * @param oid Pointer where to store the OID of the
+ * newly created tag
+ *
+ * @param repo Repository where to store the tag
+ *
+ * @param tag_name Name for the tag
+ *
+ * @param target Object to which this tag points. This object
+ * must belong to the given `repo`.
+ *
+ * @param tagger Signature of the tagger for this tag, and
+ * of the tagging time
+ *
+ * @param message Full message for this tag
+ *
+ * @return 0 on success or an error code
+ */
+GIT_EXTERN(int) git_tag_annotation_create(
+	git_oid *oid,
+	git_repository *repo,
+	const char *tag_name,
+	const git_object *target,
+	const git_signature *tagger,
+	const char *message);
+
+/**
+ * Create a new tag in the repository from a buffer
+ *
+ * @param oid Pointer where to store the OID of the newly created tag
+ * @param repo Repository where to store the tag
+ * @param buffer Raw tag data
+ * @param force Overwrite existing tags
+ * @return 0 on success; error code otherwise
+ */
+GIT_EXTERN(int) git_tag_create_frombuffer(
+	git_oid *oid,
+	git_repository *repo,
+	const char *buffer,
+	int force);
+
+/**
+ * Create a new lightweight tag pointing at a target object
+ *
+ * A new direct reference will be created pointing to
+ * this target object. If `force` is true and a reference
+ * already exists with the given name, it'll be replaced.
+ *
+ * The tag name will be checked for validity.
+ * See `git_tag_create()` for rules about valid names.
+ *
+ * @param oid Pointer where to store the OID of the provided
+ * target object. If the tag already exists, this parameter
+ * will be filled with the oid of the existing pointed object
+ * and the function will return a GIT_EEXISTS error code.
+ *
+ * @param repo Repository where to store the lightweight tag
+ *
+ * @param tag_name Name for the tag; this name is validated
+ * for consistency. It should also not conflict with an
+ * already existing tag name
+ *
+ * @param target Object to which this tag points. This object
+ * must belong to the given `repo`.
+ *
+ * @param force Overwrite existing references
+ *
+ * @return 0 on success, GIT_EINVALIDSPEC or an error code
+ *	A proper reference is written in the /refs/tags folder,
+ * pointing to the provided target object
+ */
+GIT_EXTERN(int) git_tag_create_lightweight(
+	git_oid *oid,
+	git_repository *repo,
+	const char *tag_name,
+	const git_object *target,
+	int force);
+
+/**
+ * Delete an existing tag reference.
+ *
+ * The tag name will be checked for validity.
+ * See `git_tag_create()` for rules about valid names.
+ *
+ * @param repo Repository where lives the tag
+ *
+ * @param tag_name Name of the tag to be deleted;
+ * this name is validated for consistency.
+ *
+ * @return 0 on success, GIT_EINVALIDSPEC or an error code
+ */
+GIT_EXTERN(int) git_tag_delete(
+	git_repository *repo,
+	const char *tag_name);
+
+/**
+ * Fill a list with all the tags in the Repository
+ *
+ * The string array will be filled with the names of the
+ * matching tags; these values are owned by the user and
+ * should be free'd manually when no longer needed, using
+ * `git_strarray_free`.
+ *
+ * @param tag_names Pointer to a git_strarray structure where
+ *		the tag names will be stored
+ * @param repo Repository where to find the tags
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_tag_list(
+	git_strarray *tag_names,
+	git_repository *repo);
+
+/**
+ * Fill a list with all the tags in the Repository
+ * which name match a defined pattern
+ *
+ * If an empty pattern is provided, all the tags
+ * will be returned.
+ *
+ * The string array will be filled with the names of the
+ * matching tags; these values are owned by the user and
+ * should be free'd manually when no longer needed, using
+ * `git_strarray_free`.
+ *
+ * @param tag_names Pointer to a git_strarray structure where
+ *		the tag names will be stored
+ * @param pattern Standard fnmatch pattern
+ * @param repo Repository where to find the tags
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_tag_list_match(
+	git_strarray *tag_names,
+	const char *pattern,
+	git_repository *repo);
+
+
+typedef int (*git_tag_foreach_cb)(const char *name, git_oid *oid, void *payload);
+
+/**
+ * Call callback `cb' for each tag in the repository
+ *
+ * @param repo Repository
+ * @param callback Callback function
+ * @param payload Pointer to callback data (optional)
+ */
+GIT_EXTERN(int) git_tag_foreach(
+	git_repository *repo,
+	git_tag_foreach_cb callback,
+	void *payload);
+
+
+/**
+ * Recursively peel a tag until a non tag git_object is found
+ *
+ * The retrieved `tag_target` object is owned by the repository
+ * and should be closed with the `git_object_free` method.
+ *
+ * @param tag_target_out Pointer to the peeled git_object
+ * @param tag The tag to be processed
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_tag_peel(
+	git_object **tag_target_out,
+	const git_tag *tag);
+
+/**
+ * Create an in-memory copy of a tag. The copy must be explicitly
+ * free'd or it will leak.
+ *
+ * @param out Pointer to store the copy of the tag
+ * @param source Original tag to copy
+ */
+GIT_EXTERN(int) git_tag_dup(git_tag **out, git_tag *source);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/trace.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/trace.h b/vendor/libgit2-sys/libgit2/include/git2/trace.h
new file mode 100644
index 0000000..f9b4d6f
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/trace.h
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_trace_h__
+#define INCLUDE_git_trace_h__
+
+#include "common.h"
+#include "types.h"
+
+/**
+ * @file git2/trace.h
+ * @brief Git tracing configuration routines
+ * @defgroup git_trace Git tracing configuration routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Available tracing levels.  When tracing is set to a particular level,
+ * callers will be provided tracing at the given level and all lower levels.
+ */
+typedef enum {
+	/** No tracing will be performed. */
+	GIT_TRACE_NONE = 0,
+
+	/** Severe errors that may impact the program's execution */
+	GIT_TRACE_FATAL = 1,
+
+	/** Errors that do not impact the program's execution */
+	GIT_TRACE_ERROR = 2,
+
+	/** Warnings that suggest abnormal data */
+	GIT_TRACE_WARN = 3,
+
+	/** Informational messages about program execution */
+	GIT_TRACE_INFO = 4,
+
+	/** Detailed data that allows for debugging */
+	GIT_TRACE_DEBUG = 5,
+
+	/** Exceptionally detailed debugging data */
+	GIT_TRACE_TRACE = 6
+} git_trace_level_t;
+
+/**
+ * An instance for a tracing function
+ */
+typedef void (*git_trace_callback)(git_trace_level_t level, const char *msg);
+
+/**
+ * Sets the system tracing configuration to the specified level with the
+ * specified callback.  When system events occur at a level equal to, or
+ * lower than, the given level they will be reported to the given callback.
+ *
+ * @param level Level to set tracing to
+ * @param cb Function to call with trace data
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_trace_set(git_trace_level_t level, git_trace_callback cb);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/transaction.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/transaction.h b/vendor/libgit2-sys/libgit2/include/git2/transaction.h
new file mode 100644
index 0000000..00ca139
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/transaction.h
@@ -0,0 +1,120 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_transaction_h__
+#define INCLUDE_git_transaction_h__
+
+#include "common.h"
+
+/**
+ * @file git2/transaction.h
+ * @brief Git transactional reference routines
+ * @defgroup git_transaction Git transactional reference routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Create a new transaction object
+ *
+ * This does not lock anything, but sets up the transaction object to
+ * know from which repository to lock.
+ *
+ * @param out the resulting transaction
+ * @param repo the repository in which to lock
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_transaction_new(git_transaction **out, git_repository *repo);
+
+/**
+ * Lock a reference
+ *
+ * Lock the specified reference. This is the first step to updating a
+ * reference.
+ *
+ * @param tx the transaction
+ * @param refname the reference to lock
+ * @return 0 or an error message
+ */
+GIT_EXTERN(int) git_transaction_lock_ref(git_transaction *tx, const char *refname);
+
+/**
+ * Set the target of a reference
+ *
+ * Set the target of the specified reference. This reference must be
+ * locked.
+ *
+ * @param tx the transaction
+ * @param refname reference to update
+ * @param target target to set the reference to
+ * @param sig signature to use in the reflog; pass NULL to read the identity from the config
+ * @param msg message to use in the reflog
+ * @return 0, GIT_ENOTFOUND if the reference is not among the locked ones, or an error code
+ */
+GIT_EXTERN(int) git_transaction_set_target(git_transaction *tx, const char *refname, const git_oid *target, const git_signature *sig, const char *msg);
+
+/**
+ * Set the target of a reference
+ *
+ * Set the target of the specified reference. This reference must be
+ * locked.
+ *
+ * @param tx the transaction
+ * @param refname reference to update
+ * @param target target to set the reference to
+ * @param sig signature to use in the reflog; pass NULL to read the identity from the config
+ * @param msg message to use in the reflog
+ * @return 0, GIT_ENOTFOUND if the reference is not among the locked ones, or an error code
+ */
+GIT_EXTERN(int) git_transaction_set_symbolic_target(git_transaction *tx, const char *refname, const char *target, const git_signature *sig, const char *msg);
+
+/**
+ * Set the reflog of a reference
+ *
+ * Set the specified reference's reflog. If this is combined with
+ * setting the target, that update won't be written to the reflog.
+ *
+ * @param tx the transaction
+ * @param refname the reference whose reflog to set
+ * @param reflog the reflog as it should be written out
+ * @return 0, GIT_ENOTFOUND if the reference is not among the locked ones, or an error code
+ */
+GIT_EXTERN(int) git_transaction_set_reflog(git_transaction *tx, const char *refname, const git_reflog *reflog);
+
+/**
+ * Remove a reference
+ *
+ * @param tx the transaction
+ * @param refname the reference to remove
+ * @return 0, GIT_ENOTFOUND if the reference is not among the locked ones, or an error code
+ */
+GIT_EXTERN(int) git_transaction_remove(git_transaction *tx, const char *refname);
+
+/**
+ * Commit the changes from the transaction
+ *
+ * Perform the changes that have been queued. The updates will be made
+ * one by one, and the first failure will stop the processing.
+ *
+ * @param tx the transaction
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_transaction_commit(git_transaction *tx);
+
+/**
+ * Free the resources allocated by this transaction
+ *
+ * If any references remain locked, they will be unlocked without any
+ * changes made to them.
+ *
+ * @param tx the transaction
+ */
+GIT_EXTERN(void) git_transaction_free(git_transaction *tx);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/transport.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/transport.h b/vendor/libgit2-sys/libgit2/include/git2/transport.h
new file mode 100644
index 0000000..0c371bf
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/transport.h
@@ -0,0 +1,342 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_transport_h__
+#define INCLUDE_git_transport_h__
+
+#include "indexer.h"
+#include "net.h"
+#include "types.h"
+
+/**
+ * @file git2/transport.h
+ * @brief Git transport interfaces and functions
+ * @defgroup git_transport interfaces and functions
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/** Signature of a function which creates a transport */
+typedef int (*git_transport_cb)(git_transport **out, git_remote *owner, void *param);
+
+/**
+ * Type of SSH host fingerprint
+ */
+typedef enum {
+	/** MD5 is available */
+	GIT_CERT_SSH_MD5 = (1 << 0),
+	/** SHA-1 is available */
+	GIT_CERT_SSH_SHA1 = (1 << 1),
+} git_cert_ssh_t;
+
+/**
+ * Hostkey information taken from libssh2
+ */
+typedef struct {
+	git_cert parent;
+
+	/**
+	 * A hostkey type from libssh2, either
+	 * `GIT_CERT_SSH_MD5` or `GIT_CERT_SSH_SHA1`
+	 */
+	git_cert_ssh_t type;
+
+	/**
+	 * Hostkey hash. If type has `GIT_CERT_SSH_MD5` set, this will
+	 * have the MD5 hash of the hostkey.
+	 */
+	unsigned char hash_md5[16];
+
+	/**
+	 * Hostkey hash. If type has `GIT_CERT_SSH_SHA1` set, this will
+	 * have the SHA-1 hash of the hostkey.
+	 */
+	unsigned char hash_sha1[20];
+} git_cert_hostkey;
+
+/**
+ * X.509 certificate information
+ */
+typedef struct {
+	git_cert parent;
+	/**
+	 * Pointer to the X.509 certificate data
+	 */
+	void *data;
+	/**
+	 * Length of the memory block pointed to by `data`.
+	 */
+	size_t len;
+} git_cert_x509;
+
+/*
+ *** Begin interface for credentials acquisition ***
+ */
+
+/** Authentication type requested */
+typedef enum {
+	/* git_cred_userpass_plaintext */
+	GIT_CREDTYPE_USERPASS_PLAINTEXT = (1u << 0),
+
+	/* git_cred_ssh_key */
+	GIT_CREDTYPE_SSH_KEY = (1u << 1),
+
+	/* git_cred_ssh_custom */
+	GIT_CREDTYPE_SSH_CUSTOM = (1u << 2),
+
+	/* git_cred_default */
+	GIT_CREDTYPE_DEFAULT = (1u << 3),
+
+	/* git_cred_ssh_interactive */
+	GIT_CREDTYPE_SSH_INTERACTIVE = (1u << 4),
+
+	/**
+	 * Username-only information
+	 *
+	 * If the SSH transport does not know which username to use,
+	 * it will ask via this credential type.
+	 */
+	GIT_CREDTYPE_USERNAME = (1u << 5),
+
+	/**
+	 * Credentials read from memory.
+	 *
+	 * Only available for libssh2+OpenSSL for now.
+	 */
+	GIT_CREDTYPE_SSH_MEMORY = (1u << 6),
+} git_credtype_t;
+
+/* The base structure for all credential types */
+typedef struct git_cred git_cred;
+
+struct git_cred {
+	git_credtype_t credtype;
+	void (*free)(git_cred *cred);
+};
+
+/** A plaintext username and password */
+typedef struct {
+	git_cred parent;
+	char *username;
+	char *password;
+} git_cred_userpass_plaintext;
+
+
+/*
+ * If the user hasn't included libssh2.h before git2.h, we need to
+ * define a few types for the callback signatures.
+ */
+#ifndef LIBSSH2_VERSION
+typedef struct _LIBSSH2_SESSION LIBSSH2_SESSION;
+typedef struct _LIBSSH2_USERAUTH_KBDINT_PROMPT LIBSSH2_USERAUTH_KBDINT_PROMPT;
+typedef struct _LIBSSH2_USERAUTH_KBDINT_RESPONSE LIBSSH2_USERAUTH_KBDINT_RESPONSE;
+#endif
+
+typedef int (*git_cred_sign_callback)(LIBSSH2_SESSION *session, unsigned char **sig, size_t *sig_len, const unsigned char *data, size_t data_len, void **abstract);
+typedef void (*git_cred_ssh_interactive_callback)(const char* name, int name_len, const char* instruction, int instruction_len, int num_prompts, const LIBSSH2_USERAUTH_KBDINT_PROMPT* prompts, LIBSSH2_USERAUTH_KBDINT_RESPONSE* responses, void **abstract);
+
+/**
+ * A ssh key from disk
+ */
+typedef struct git_cred_ssh_key {
+	git_cred parent;
+	char *username;
+	char *publickey;
+	char *privatekey;
+	char *passphrase;
+} git_cred_ssh_key;
+
+/**
+ * Keyboard-interactive based ssh authentication
+ */
+typedef struct git_cred_ssh_interactive {
+	git_cred parent;
+	char *username;
+	git_cred_ssh_interactive_callback prompt_callback;
+	void *payload;
+} git_cred_ssh_interactive;
+
+/**
+ * A key with a custom signature function
+ */
+typedef struct git_cred_ssh_custom {
+	git_cred parent;
+	char *username;
+	char *publickey;
+	size_t publickey_len;
+	git_cred_sign_callback sign_callback;
+	void *payload;
+} git_cred_ssh_custom;
+
+/** A key for NTLM/Kerberos "default" credentials */
+typedef struct git_cred git_cred_default;
+
+/** Username-only credential information */
+typedef struct git_cred_username {
+	git_cred parent;
+	char username[1];
+} git_cred_username;
+
+/**
+ * Check whether a credential object contains username information.
+ *
+ * @param cred object to check
+ * @return 1 if the credential object has non-NULL username, 0 otherwise
+ */
+GIT_EXTERN(int) git_cred_has_username(git_cred *cred);
+
+/**
+ * Create a new plain-text username and password credential object.
+ * The supplied credential parameter will be internally duplicated.
+ *
+ * @param out The newly created credential object.
+ * @param username The username of the credential.
+ * @param password The password of the credential.
+ * @return 0 for success or an error code for failure
+ */
+GIT_EXTERN(int) git_cred_userpass_plaintext_new(
+	git_cred **out,
+	const char *username,
+	const char *password);
+
+/**
+ * Create a new passphrase-protected ssh key credential object.
+ * The supplied credential parameter will be internally duplicated.
+ *
+ * @param out The newly created credential object.
+ * @param username username to use to authenticate
+ * @param publickey The path to the public key of the credential.
+ * @param privatekey The path to the private key of the credential.
+ * @param passphrase The passphrase of the credential.
+ * @return 0 for success or an error code for failure
+ */
+GIT_EXTERN(int) git_cred_ssh_key_new(
+	git_cred **out,
+	const char *username,
+	const char *publickey,
+	const char *privatekey,
+	const char *passphrase);
+
+/**
+ * Create a new ssh keyboard-interactive based credential object.
+ * The supplied credential parameter will be internally duplicated.
+ *
+ * @param username Username to use to authenticate.
+ * @param prompt_callback The callback method used for prompts.
+ * @param payload Additional data to pass to the callback.
+ * @return 0 for success or an error code for failure.
+ */
+GIT_EXTERN(int) git_cred_ssh_interactive_new(
+	git_cred **out,
+	const char *username,
+	git_cred_ssh_interactive_callback prompt_callback,
+	void *payload);
+
+/**
+ * Create a new ssh key credential object used for querying an ssh-agent.
+ * The supplied credential parameter will be internally duplicated.
+ *
+ * @param out The newly created credential object.
+ * @param username username to use to authenticate
+ * @return 0 for success or an error code for failure
+ */
+GIT_EXTERN(int) git_cred_ssh_key_from_agent(
+	git_cred **out,
+	const char *username);
+
+/**
+ * Create an ssh key credential with a custom signing function.
+ *
+ * This lets you use your own function to sign the challenge.
+ *
+ * This function and its credential type is provided for completeness
+ * and wraps `libssh2_userauth_publickey()`, which is undocumented.
+ *
+ * The supplied credential parameter will be internally duplicated.
+ *
+ * @param out The newly created credential object.
+ * @param username username to use to authenticate
+ * @param publickey The bytes of the public key.
+ * @param publickey_len The length of the public key in bytes.
+ * @param sign_callback The callback method to sign the data during the challenge.
+ * @param payload Additional data to pass to the callback.
+ * @return 0 for success or an error code for failure
+ */
+GIT_EXTERN(int) git_cred_ssh_custom_new(
+	git_cred **out,
+	const char *username,
+	const char *publickey,
+	size_t publickey_len,
+	git_cred_sign_callback sign_callback,
+	void *payload);
+
+/**
+ * Create a "default" credential usable for Negotiate mechanisms like NTLM
+ * or Kerberos authentication.
+ *
+ * @return 0 for success or an error code for failure
+ */
+GIT_EXTERN(int) git_cred_default_new(git_cred **out);
+
+/**
+ * Create a credential to specify a username.
+ *
+ * This is used with ssh authentication to query for the username if
+ * none is specified in the url.
+ */
+GIT_EXTERN(int) git_cred_username_new(git_cred **cred, const char *username);
+
+/**
+ * Create a new ssh key credential object reading the keys from memory.
+ *
+ * @param out The newly created credential object.
+ * @param username username to use to authenticate.
+ * @param publickey The public key of the credential.
+ * @param privatekey The private key of the credential.
+ * @param passphrase The passphrase of the credential.
+ * @return 0 for success or an error code for failure
+ */
+GIT_EXTERN(int) git_cred_ssh_key_memory_new(
+	git_cred **out,
+	const char *username,
+	const char *publickey,
+	const char *privatekey,
+	const char *passphrase);
+
+
+/**
+ * Free a credential.
+ *
+ * This is only necessary if you own the object; that is, if you are a
+ * transport.
+ *
+ * @param cred the object to free
+ */
+GIT_EXTERN(void) git_cred_free(git_cred *cred);
+
+/**
+ * Signature of a function which acquires a credential object.
+ *
+ * @param cred The newly created credential object.
+ * @param url The resource for which we are demanding a credential.
+ * @param username_from_url The username that was embedded in a "user\@host"
+ *                          remote url, or NULL if not included.
+ * @param allowed_types A bitmask stating which cred types are OK to return.
+ * @param payload The payload provided when specifying this callback.
+ * @return 0 for success, < 0 to indicate an error, > 0 to indicate
+ *       no credential was acquired
+ */
+typedef int (*git_cred_acquire_cb)(
+	git_cred **cred,
+	const char *url,
+	const char *username_from_url,
+	unsigned int allowed_types,
+	void *payload);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/tree.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/tree.h b/vendor/libgit2-sys/libgit2/include/git2/tree.h
new file mode 100644
index 0000000..1a363c1
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/tree.h
@@ -0,0 +1,484 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_tree_h__
+#define INCLUDE_git_tree_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+#include "object.h"
+
+/**
+ * @file git2/tree.h
+ * @brief Git tree parsing, loading routines
+ * @defgroup git_tree Git tree parsing, loading routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Lookup a tree object from the repository.
+ *
+ * @param out Pointer to the looked up tree
+ * @param repo The repo to use when locating the tree.
+ * @param id Identity of the tree to locate.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_tree_lookup(
+	git_tree **out, git_repository *repo, const git_oid *id);
+
+/**
+ * Lookup a tree object from the repository,
+ * given a prefix of its identifier (short id).
+ *
+ * @see git_object_lookup_prefix
+ *
+ * @param out pointer to the looked up tree
+ * @param repo the repo to use when locating the tree.
+ * @param id identity of the tree to locate.
+ * @param len the length of the short identifier
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_tree_lookup_prefix(
+	git_tree **out,
+	git_repository *repo,
+	const git_oid *id,
+	size_t len);
+
+/**
+ * Close an open tree
+ *
+ * You can no longer use the git_tree pointer after this call.
+ *
+ * IMPORTANT: You MUST call this method when you stop using a tree to
+ * release memory. Failure to do so will cause a memory leak.
+ *
+ * @param tree The tree to close
+ */
+GIT_EXTERN(void) git_tree_free(git_tree *tree);
+
+/**
+ * Get the id of a tree.
+ *
+ * @param tree a previously loaded tree.
+ * @return object identity for the tree.
+ */
+GIT_EXTERN(const git_oid *) git_tree_id(const git_tree *tree);
+
+/**
+ * Get the repository that contains the tree.
+ *
+ * @param tree A previously loaded tree.
+ * @return Repository that contains this tree.
+ */
+GIT_EXTERN(git_repository *) git_tree_owner(const git_tree *tree);
+
+/**
+ * Get the number of entries listed in a tree
+ *
+ * @param tree a previously loaded tree.
+ * @return the number of entries in the tree
+ */
+GIT_EXTERN(size_t) git_tree_entrycount(const git_tree *tree);
+
+/**
+ * Lookup a tree entry by its filename
+ *
+ * This returns a git_tree_entry that is owned by the git_tree.  You don't
+ * have to free it, but you must not use it after the git_tree is released.
+ *
+ * @param tree a previously loaded tree.
+ * @param filename the filename of the desired entry
+ * @return the tree entry; NULL if not found
+ */
+GIT_EXTERN(const git_tree_entry *) git_tree_entry_byname(
+	const git_tree *tree, const char *filename);
+
+/**
+ * Lookup a tree entry by its position in the tree
+ *
+ * This returns a git_tree_entry that is owned by the git_tree.  You don't
+ * have to free it, but you must not use it after the git_tree is released.
+ *
+ * @param tree a previously loaded tree.
+ * @param idx the position in the entry list
+ * @return the tree entry; NULL if not found
+ */
+GIT_EXTERN(const git_tree_entry *) git_tree_entry_byindex(
+	const git_tree *tree, size_t idx);
+
+/**
+ * Lookup a tree entry by SHA value.
+ *
+ * This returns a git_tree_entry that is owned by the git_tree.  You don't
+ * have to free it, but you must not use it after the git_tree is released.
+ *
+ * Warning: this must examine every entry in the tree, so it is not fast.
+ *
+ * @param tree a previously loaded tree.
+ * @param id the sha being looked for
+ * @return the tree entry; NULL if not found
+ */
+GIT_EXTERN(const git_tree_entry *) git_tree_entry_byid(
+	const git_tree *tree, const git_oid *id);
+
+/**
+ * Retrieve a tree entry contained in a tree or in any of its subtrees,
+ * given its relative path.
+ *
+ * Unlike the other lookup functions, the returned tree entry is owned by
+ * the user and must be freed explicitly with `git_tree_entry_free()`.
+ *
+ * @param out Pointer where to store the tree entry
+ * @param root Previously loaded tree which is the root of the relative path
+ * @param path Path to the contained entry
+ * @return 0 on success; GIT_ENOTFOUND if the path does not exist
+ */
+GIT_EXTERN(int) git_tree_entry_bypath(
+	git_tree_entry **out,
+	const git_tree *root,
+	const char *path);
+
+/**
+ * Duplicate a tree entry
+ *
+ * Create a copy of a tree entry. The returned copy is owned by the user,
+ * and must be freed explicitly with `git_tree_entry_free()`.
+ *
+ * @param dest pointer where to store the copy
+ * @param source tree entry to duplicate
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_tree_entry_dup(git_tree_entry **dest, const git_tree_entry *source);
+
+/**
+ * Free a user-owned tree entry
+ *
+ * IMPORTANT: This function is only needed for tree entries owned by the
+ * user, such as the ones returned by `git_tree_entry_dup()` or
+ * `git_tree_entry_bypath()`.
+ *
+ * @param entry The entry to free
+ */
+GIT_EXTERN(void) git_tree_entry_free(git_tree_entry *entry);
+
+/**
+ * Get the filename of a tree entry
+ *
+ * @param entry a tree entry
+ * @return the name of the file
+ */
+GIT_EXTERN(const char *) git_tree_entry_name(const git_tree_entry *entry);
+
+/**
+ * Get the id of the object pointed by the entry
+ *
+ * @param entry a tree entry
+ * @return the oid of the object
+ */
+GIT_EXTERN(const git_oid *) git_tree_entry_id(const git_tree_entry *entry);
+
+/**
+ * Get the type of the object pointed by the entry
+ *
+ * @param entry a tree entry
+ * @return the type of the pointed object
+ */
+GIT_EXTERN(git_otype) git_tree_entry_type(const git_tree_entry *entry);
+
+/**
+ * Get the UNIX file attributes of a tree entry
+ *
+ * @param entry a tree entry
+ * @return filemode as an integer
+ */
+GIT_EXTERN(git_filemode_t) git_tree_entry_filemode(const git_tree_entry *entry);
+
+/**
+ * Get the raw UNIX file attributes of a tree entry
+ *
+ * This function does not perform any normalization and is only useful
+ * if you need to be able to recreate the original tree object.
+ *
+ * @param entry a tree entry
+ * @return filemode as an integer
+ */
+
+GIT_EXTERN(git_filemode_t) git_tree_entry_filemode_raw(const git_tree_entry *entry);
+/**
+ * Compare two tree entries
+ *
+ * @param e1 first tree entry
+ * @param e2 second tree entry
+ * @return <0 if e1 is before e2, 0 if e1 == e2, >0 if e1 is after e2
+ */
+GIT_EXTERN(int) git_tree_entry_cmp(const git_tree_entry *e1, const git_tree_entry *e2);
+
+/**
+ * Convert a tree entry to the git_object it points to.
+ *
+ * You must call `git_object_free()` on the object when you are done with it.
+ *
+ * @param object_out pointer to the converted object
+ * @param repo repository where to lookup the pointed object
+ * @param entry a tree entry
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_tree_entry_to_object(
+	git_object **object_out,
+	git_repository *repo,
+	const git_tree_entry *entry);
+
+/**
+ * Create a new tree builder.
+ *
+ * The tree builder can be used to create or modify trees in memory and
+ * write them as tree objects to the database.
+ *
+ * If the `source` parameter is not NULL, the tree builder will be
+ * initialized with the entries of the given tree.
+ *
+ * If the `source` parameter is NULL, the tree builder will start with no
+ * entries and will have to be filled manually.
+ *
+ * @param out Pointer where to store the tree builder
+ * @param repo Repository in which to store the object
+ * @param source Source tree to initialize the builder (optional)
+ * @return 0 on success; error code otherwise
+ */
+GIT_EXTERN(int) git_treebuilder_new(
+	git_treebuilder **out, git_repository *repo, const git_tree *source);
+
+/**
+ * Clear all the entires in the builder
+ *
+ * @param bld Builder to clear
+ */
+GIT_EXTERN(void) git_treebuilder_clear(git_treebuilder *bld);
+
+/**
+ * Get the number of entries listed in a treebuilder
+ *
+ * @param bld a previously loaded treebuilder.
+ * @return the number of entries in the treebuilder
+ */
+GIT_EXTERN(unsigned int) git_treebuilder_entrycount(git_treebuilder *bld);
+
+/**
+ * Free a tree builder
+ *
+ * This will clear all the entries and free to builder.
+ * Failing to free the builder after you're done using it
+ * will result in a memory leak
+ *
+ * @param bld Builder to free
+ */
+GIT_EXTERN(void) git_treebuilder_free(git_treebuilder *bld);
+
+/**
+ * Get an entry from the builder from its filename
+ *
+ * The returned entry is owned by the builder and should
+ * not be freed manually.
+ *
+ * @param bld Tree builder
+ * @param filename Name of the entry
+ * @return pointer to the entry; NULL if not found
+ */
+GIT_EXTERN(const git_tree_entry *) git_treebuilder_get(
+	git_treebuilder *bld, const char *filename);
+
+/**
+ * Add or update an entry to the builder
+ *
+ * Insert a new entry for `filename` in the builder with the
+ * given attributes.
+ *
+ * If an entry named `filename` already exists, its attributes
+ * will be updated with the given ones.
+ *
+ * The optional pointer `out` can be used to retrieve a pointer to the
+ * newly created/updated entry.  Pass NULL if you do not need it. The
+ * pointer may not be valid past the next operation in this
+ * builder. Duplicate the entry if you want to keep it.
+ *
+ * By default the entry that you are inserting will be checked for
+ * validity; that it exists in the object database and is of the
+ * correct type.  If you do not want this behavior, set the
+ * `GIT_OPT_ENABLE_STRICT_OBJECT_CREATION` library option to false.
+ *
+ * @param out Pointer to store the entry (optional)
+ * @param bld Tree builder
+ * @param filename Filename of the entry
+ * @param id SHA1 oid of the entry
+ * @param filemode Folder attributes of the entry. This parameter must
+ *			be valued with one of the following entries: 0040000, 0100644,
+ *			0100755, 0120000 or 0160000.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_treebuilder_insert(
+	const git_tree_entry **out,
+	git_treebuilder *bld,
+	const char *filename,
+	const git_oid *id,
+	git_filemode_t filemode);
+
+/**
+ * Remove an entry from the builder by its filename
+ *
+ * @param bld Tree builder
+ * @param filename Filename of the entry to remove
+ */
+GIT_EXTERN(int) git_treebuilder_remove(
+	git_treebuilder *bld, const char *filename);
+
+/**
+ * Callback for git_treebuilder_filter
+ *
+ * The return value is treated as a boolean, with zero indicating that the
+ * entry should be left alone and any non-zero value meaning that the
+ * entry should be removed from the treebuilder list (i.e. filtered out).
+ */
+typedef int (*git_treebuilder_filter_cb)(
+	const git_tree_entry *entry, void *payload);
+
+/**
+ * Selectively remove entries in the tree
+ *
+ * The `filter` callback will be called for each entry in the tree with a
+ * pointer to the entry and the provided `payload`; if the callback returns
+ * non-zero, the entry will be filtered (removed from the builder).
+ *
+ * @param bld Tree builder
+ * @param filter Callback to filter entries
+ * @param payload Extra data to pass to filter callback
+ */
+GIT_EXTERN(void) git_treebuilder_filter(
+	git_treebuilder *bld,
+	git_treebuilder_filter_cb filter,
+	void *payload);
+
+/**
+ * Write the contents of the tree builder as a tree object
+ *
+ * The tree builder will be written to the given `repo`, and its
+ * identifying SHA1 hash will be stored in the `id` pointer.
+ *
+ * @param id Pointer to store the OID of the newly written tree
+ * @param bld Tree builder to write
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_treebuilder_write(
+	git_oid *id, git_treebuilder *bld);
+
+/**
+ * Write the contents of the tree builder as a tree object
+ * using a shared git_buf.
+ *
+ * @see git_treebuilder_write
+ *
+ * @param oid Pointer to store the OID of the newly written tree
+ * @param bld Tree builder to write
+ * @param tree Shared buffer for writing the tree. Will be grown as necessary.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_treebuilder_write_with_buffer(
+	git_oid *oid, git_treebuilder *bld, git_buf *tree);
+
+/** Callback for the tree traversal method */
+typedef int (*git_treewalk_cb)(
+	const char *root, const git_tree_entry *entry, void *payload);
+
+/** Tree traversal modes */
+typedef enum {
+	GIT_TREEWALK_PRE = 0, /* Pre-order */
+	GIT_TREEWALK_POST = 1, /* Post-order */
+} git_treewalk_mode;
+
+/**
+ * Traverse the entries in a tree and its subtrees in post or pre order.
+ *
+ * The entries will be traversed in the specified order, children subtrees
+ * will be automatically loaded as required, and the `callback` will be
+ * called once per entry with the current (relative) root for the entry and
+ * the entry data itself.
+ *
+ * If the callback returns a positive value, the passed entry will be
+ * skipped on the traversal (in pre mode). A negative value stops the walk.
+ *
+ * @param tree The tree to walk
+ * @param mode Traversal mode (pre or post-order)
+ * @param callback Function to call on each tree entry
+ * @param payload Opaque pointer to be passed on each callback
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_tree_walk(
+	const git_tree *tree,
+	git_treewalk_mode mode,
+	git_treewalk_cb callback,
+	void *payload);
+
+/**
+ * Create an in-memory copy of a tree. The copy must be explicitly
+ * free'd or it will leak.
+ *
+ * @param out Pointer to store the copy of the tree
+ * @param source Original tree to copy
+ */
+GIT_EXTERN(int) git_tree_dup(git_tree **out, git_tree *source);
+
+/**
+ * The kind of update to perform
+ */
+typedef enum {
+	/** Update or insert an entry at the specified path */
+	GIT_TREE_UPDATE_UPSERT,
+	/** Remove an entry from the specified path */
+	GIT_TREE_UPDATE_REMOVE,
+} git_tree_update_t;
+
+/**
+ * An action to perform during the update of a tree
+ */
+typedef struct {
+	/** Update action. If it's an removal, only the path is looked at */
+	git_tree_update_t action;
+	/** The entry's id */
+	git_oid id;
+	/** The filemode/kind of object */
+	git_filemode_t filemode;
+	/** The full path from the root tree */
+	const char *path;
+} git_tree_update;
+
+/**
+ * Create a tree based on another one with the specified modifications
+ *
+ * Given the `baseline` perform the changes described in the list of
+ * `updates` and create a new tree.
+ *
+ * This function is optimized for common file/directory addition, removal and
+ * replacement in trees. It is much more efficient than reading the tree into a
+ * `git_index` and modifying that, but in exchange it is not as flexible.
+ *
+ * Deleting and adding the same entry is undefined behaviour, changing
+ * a tree to a blob or viceversa is not supported.
+ *
+ * @param out id of the new tree
+ * @param repo the repository in which to create the tree, must be the
+ * same as for `baseline`
+ * @param baseline the tree to base these changes on
+ * @param nupdates the number of elements in the update list
+ * @param updates the list of updates to perform
+ */
+GIT_EXTERN(int) git_tree_create_updated(git_oid *out, git_repository *repo, git_tree *baseline, size_t nupdates, const git_tree_update *updates);
+
+/** @} */
+
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/include/git2/types.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/types.h b/vendor/libgit2-sys/libgit2/include/git2/types.h
new file mode 100644
index 0000000..ad34e01
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/types.h
@@ -0,0 +1,437 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_types_h__
+#define INCLUDE_git_types_h__
+
+#include "common.h"
+
+/**
+ * @file git2/types.h
+ * @brief libgit2 base & compatibility types
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Cross-platform compatibility types for off_t / time_t
+ *
+ * NOTE: This needs to be in a public header so that both the library
+ * implementation and client applications both agree on the same types.
+ * Otherwise we get undefined behavior.
+ *
+ * Use the "best" types that each platform provides. Currently we truncate
+ * these intermediate representations for compatibility with the git ABI, but
+ * if and when it changes to support 64 bit types, our code will naturally
+ * adapt.
+ * NOTE: These types should match those that are returned by our internal
+ * stat() functions, for all platforms.
+ */
+#include <sys/types.h>
+#ifdef __amigaos4__
+#include <stdint.h>
+#endif
+
+#if defined(_MSC_VER)
+
+typedef __int64 git_off_t;
+typedef __time64_t git_time_t;
+
+#elif defined(__MINGW32__)
+
+typedef off64_t git_off_t;
+typedef __time64_t git_time_t;
+
+#elif defined(__HAIKU__)
+
+typedef __haiku_std_int64 git_off_t;
+typedef __haiku_std_int64 git_time_t;
+
+#else /* POSIX */
+
+/*
+ * Note: Can't use off_t since if a client program includes <sys/types.h>
+ * before us (directly or indirectly), they'll get 32 bit off_t in their client
+ * app, even though /we/ define _FILE_OFFSET_BITS=64.
+ */
+typedef int64_t git_off_t;
+typedef int64_t git_time_t;
+
+#endif
+
+/** Basic type (loose or packed) of any Git object. */
+typedef enum {
+	GIT_OBJ_ANY = -2,		/**< Object can be any of the following */
+	GIT_OBJ_BAD = -1,		/**< Object is invalid. */
+	GIT_OBJ__EXT1 = 0,		/**< Reserved for future use. */
+	GIT_OBJ_COMMIT = 1,		/**< A commit object. */
+	GIT_OBJ_TREE = 2,		/**< A tree (directory listing) object. */
+	GIT_OBJ_BLOB = 3,		/**< A file revision object. */
+	GIT_OBJ_TAG = 4,		/**< An annotated tag object. */
+	GIT_OBJ__EXT2 = 5,		/**< Reserved for future use. */
+	GIT_OBJ_OFS_DELTA = 6, /**< A delta, base is given by an offset. */
+	GIT_OBJ_REF_DELTA = 7, /**< A delta, base is given by object id. */
+} git_otype;
+
+/** An open object database handle. */
+typedef struct git_odb git_odb;
+
+/** A custom backend in an ODB */
+typedef struct git_odb_backend git_odb_backend;
+
+/** An object read from the ODB */
+typedef struct git_odb_object git_odb_object;
+
+/** A stream to read/write from the ODB */
+typedef struct git_odb_stream git_odb_stream;
+
+/** A stream to write a packfile to the ODB */
+typedef struct git_odb_writepack git_odb_writepack;
+
+/** An open refs database handle. */
+typedef struct git_refdb git_refdb;
+
+/** A custom backend for refs */
+typedef struct git_refdb_backend git_refdb_backend;
+
+/**
+ * Representation of an existing git repository,
+ * including all its object contents
+ */
+typedef struct git_repository git_repository;
+
+/** Representation of a working tree */
+typedef struct git_worktree git_worktree;
+
+/** Representation of a generic object in a repository */
+typedef struct git_object git_object;
+
+/** Representation of an in-progress walk through the commits in a repo */
+typedef struct git_revwalk git_revwalk;
+
+/** Parsed representation of a tag object. */
+typedef struct git_tag git_tag;
+
+/** In-memory representation of a blob object. */
+typedef struct git_blob git_blob;
+
+/** Parsed representation of a commit object. */
+typedef struct git_commit git_commit;
+
+/** Representation of each one of the entries in a tree object. */
+typedef struct git_tree_entry git_tree_entry;
+
+/** Representation of a tree object. */
+typedef struct git_tree git_tree;
+
+/** Constructor for in-memory trees */
+typedef struct git_treebuilder git_treebuilder;
+
+/** Memory representation of an index file. */
+typedef struct git_index git_index;
+
+/** An iterator for conflicts in the index. */
+typedef struct git_index_conflict_iterator git_index_conflict_iterator;
+
+/** Memory representation of a set of config files */
+typedef struct git_config git_config;
+
+/** Interface to access a configuration file */
+typedef struct git_config_backend git_config_backend;
+
+/** Representation of a reference log entry */
+typedef struct git_reflog_entry git_reflog_entry;
+
+/** Representation of a reference log */
+typedef struct git_reflog git_reflog;
+
+/** Representation of a git note */
+typedef struct git_note git_note;
+
+/** Representation of a git packbuilder */
+typedef struct git_packbuilder git_packbuilder;
+
+/** Time in a signature */
+typedef struct git_time {
+	git_time_t time; /**< time in seconds from epoch */
+	int offset; /**< timezone offset, in minutes */
+	char sign; /**< indicator for questionable '-0000' offsets in signature */
+} git_time;
+
+/** An action signature (e.g. for committers, taggers, etc) */
+typedef struct git_signature {
+	char *name; /**< full name of the author */
+	char *email; /**< email of the author */
+	git_time when; /**< time when the action happened */
+} git_signature;
+
+/** In-memory representation of a reference. */
+typedef struct git_reference git_reference;
+
+/** Iterator for references */
+typedef struct git_reference_iterator  git_reference_iterator;
+
+/** Transactional interface to references */
+typedef struct git_transaction git_transaction;
+
+/** Annotated commits, the input to merge and rebase. */
+typedef struct git_annotated_commit git_annotated_commit;
+
+/** Representation of a status collection */
+typedef struct git_status_list git_status_list;
+
+/** Representation of a rebase */
+typedef struct git_rebase git_rebase;
+
+/** Basic type of any Git reference. */
+typedef enum {
+	GIT_REF_INVALID = 0, /**< Invalid reference */
+	GIT_REF_OID = 1, /**< A reference which points at an object id */
+	GIT_REF_SYMBOLIC = 2, /**< A reference which points at another reference */
+	GIT_REF_LISTALL = GIT_REF_OID|GIT_REF_SYMBOLIC,
+} git_ref_t;
+
+/** Basic type of any Git branch. */
+typedef enum {
+	GIT_BRANCH_LOCAL = 1,
+	GIT_BRANCH_REMOTE = 2,
+	GIT_BRANCH_ALL = GIT_BRANCH_LOCAL|GIT_BRANCH_REMOTE,
+} git_branch_t;
+
+/** Valid modes for index and tree entries. */
+typedef enum {
+	GIT_FILEMODE_UNREADABLE          = 0000000,
+	GIT_FILEMODE_TREE                = 0040000,
+	GIT_FILEMODE_BLOB                = 0100644,
+	GIT_FILEMODE_BLOB_EXECUTABLE     = 0100755,
+	GIT_FILEMODE_LINK                = 0120000,
+	GIT_FILEMODE_COMMIT              = 0160000,
+} git_filemode_t;
+
+/*
+ * A refspec specifies the mapping between remote and local reference
+ * names when fetch or pushing.
+ */
+typedef struct git_refspec git_refspec;
+
+/**
+ * Git's idea of a remote repository. A remote can be anonymous (in
+ * which case it does not have backing configuration entires).
+ */
+typedef struct git_remote git_remote;
+
+/**
+ * Interface which represents a transport to communicate with a
+ * remote.
+ */
+typedef struct git_transport git_transport;
+
+/**
+ * Preparation for a push operation. Can be used to configure what to
+ * push and the level of parallelism of the packfile builder.
+ */
+typedef struct git_push git_push;
+
+/* documentation in the definition */
+typedef struct git_remote_head git_remote_head;
+typedef struct git_remote_callbacks git_remote_callbacks;
+
+/**
+ * This is passed as the first argument to the callback to allow the
+ * user to see the progress.
+ *
+ * - total_objects: number of objects in the packfile being downloaded
+ * - indexed_objects: received objects that have been hashed
+ * - received_objects: objects which have been downloaded
+ * - local_objects: locally-available objects that have been injected
+ *    in order to fix a thin pack.
+ * - received-bytes: size of the packfile received up to now
+ */
+typedef struct git_transfer_progress {
+	unsigned int total_objects;
+	unsigned int indexed_objects;
+	unsigned int received_objects;
+	unsigned int local_objects;
+	unsigned int total_deltas;
+	unsigned int indexed_deltas;
+	size_t received_bytes;
+} git_transfer_progress;
+
+/**
+ * Type for progress callbacks during indexing.  Return a value less than zero
+ * to cancel the transfer.
+ *
+ * @param stats Structure containing information about the state of the transfer
+ * @param payload Payload provided by caller
+ */
+typedef int (*git_transfer_progress_cb)(const git_transfer_progress *stats, void *payload);
+
+/**
+ * Type for messages delivered by the transport.  Return a negative value
+ * to cancel the network operation.
+ *
+ * @param str The message from the transport
+ * @param len The length of the message
+ * @param payload Payload provided by the caller
+ */
+typedef int (*git_transport_message_cb)(const char *str, int len, void *payload);
+
+
+/**
+ * Type of host certificate structure that is passed to the check callback
+ */
+typedef enum git_cert_t {
+	/**
+	 * No information about the certificate is available. This may
+	 * happen when using curl.
+	 */
+	GIT_CERT_NONE,
+        /**
+         * The `data` argument to the callback will be a pointer to
+         * the DER-encoded data.
+         */
+	GIT_CERT_X509,
+        /**
+         * The `data` argument to the callback will be a pointer to a
+         * `git_cert_hostkey` structure.
+         */
+	GIT_CERT_HOSTKEY_LIBSSH2,
+	/**
+	 * The `data` argument to the callback will be a pointer to a
+	 * `git_strarray` with `name:content` strings containing
+	 * information about the certificate. This is used when using
+	 * curl.
+	 */
+	GIT_CERT_STRARRAY,
+} git_cert_t;
+
+/**
+ * Parent type for `git_cert_hostkey` and `git_cert_x509`.
+ */
+typedef struct {
+	/**
+	 * Type of certificate. A `GIT_CERT_` value.
+	 */
+	git_cert_t cert_type;
+} git_cert;
+
+/**
+ * Callback for the user's custom certificate checks.
+ *
+ * @param cert The host certificate
+ * @param valid Whether the libgit2 checks (OpenSSL or WinHTTP) think
+ * this certificate is valid
+ * @param host Hostname of the host libgit2 connected to
+ * @param payload Payload provided by the caller
+ */
+typedef int (*git_transport_certificate_check_cb)(git_cert *cert, int valid, const char *host, void *payload);
+
+/**
+ * Opaque structure representing a submodule.
+ */
+typedef struct git_submodule git_submodule;
+
+/**
+ * Submodule update values
+ *
+ * These values represent settings for the `submodule.$name.update`
+ * configuration value which says how to handle `git submodule update` for
+ * this submodule.  The value is usually set in the ".gitmodules" file and
+ * copied to ".git/config" when the submodule is initialized.
+ *
+ * You can override this setting on a per-submodule basis with
+ * `git_submodule_set_update()` and write the changed value to disk using
+ * `git_submodule_save()`.  If you have overwritten the value, you can
+ * revert it by passing `GIT_SUBMODULE_UPDATE_RESET` to the set function.
+ *
+ * The values are:
+ *
+ * - GIT_SUBMODULE_UPDATE_CHECKOUT: the default; when a submodule is
+ *   updated, checkout the new detached HEAD to the submodule directory.
+ * - GIT_SUBMODULE_UPDATE_REBASE: update by rebasing the current checked
+ *   out branch onto the commit from the superproject.
+ * - GIT_SUBMODULE_UPDATE_MERGE: update by merging the commit in the
+ *   superproject into the current checkout out branch of the submodule.
+ * - GIT_SUBMODULE_UPDATE_NONE: do not update this submodule even when
+ *   the commit in the superproject is updated.
+ * - GIT_SUBMODULE_UPDATE_DEFAULT: not used except as static initializer
+ *   when we don't want any particular update rule to be specified.
+ */
+typedef enum {
+	GIT_SUBMODULE_UPDATE_CHECKOUT = 1,
+	GIT_SUBMODULE_UPDATE_REBASE   = 2,
+	GIT_SUBMODULE_UPDATE_MERGE    = 3,
+	GIT_SUBMODULE_UPDATE_NONE     = 4,
+
+	GIT_SUBMODULE_UPDATE_DEFAULT  = 0
+} git_submodule_update_t;
+
+/**
+ * Submodule ignore values
+ *
+ * These values represent settings for the `submodule.$name.ignore`
+ * configuration value which says how deeply to look at the working
+ * directory when getting submodule status.
+ *
+ * You can override this value in memory on a per-submodule basis with
+ * `git_submodule_set_ignore()` and can write the changed value to disk
+ * with `git_submodule_save()`.  If you have overwritten the value, you
+ * can revert to the on disk value by using `GIT_SUBMODULE_IGNORE_RESET`.
+ *
+ * The values are:
+ *
+ * - GIT_SUBMODULE_IGNORE_UNSPECIFIED: use the submodule's configuration
+ * - GIT_SUBMODULE_IGNORE_NONE: don't ignore any change - i.e. even an
+ *   untracked file, will mark the submodule as dirty.  Ignored files are
+ *   still ignored, of course.
+ * - GIT_SUBMODULE_IGNORE_UNTRACKED: ignore untracked files; only changes
+ *   to tracked files, or the index or the HEAD commit will matter.
+ * - GIT_SUBMODULE_IGNORE_DIRTY: ignore changes in the working directory,
+ *   only considering changes if the HEAD of submodule has moved from the
+ *   value in the superproject.
+ * - GIT_SUBMODULE_IGNORE_ALL: never check if the submodule is dirty
+ * - GIT_SUBMODULE_IGNORE_DEFAULT: not used except as static initializer
+ *   when we don't want any particular ignore rule to be specified.
+ */
+typedef enum {
+	GIT_SUBMODULE_IGNORE_UNSPECIFIED  = -1, /**< use the submodule's configuration */
+
+	GIT_SUBMODULE_IGNORE_NONE      = 1,  /**< any change or untracked == dirty */
+	GIT_SUBMODULE_IGNORE_UNTRACKED = 2,  /**< dirty if tracked files change */
+	GIT_SUBMODULE_IGNORE_DIRTY     = 3,  /**< only dirty if HEAD moved */
+	GIT_SUBMODULE_IGNORE_ALL       = 4,  /**< never dirty */
+} git_submodule_ignore_t;
+
+/**
+ * Options for submodule recurse.
+ *
+ * Represent the value of `submodule.$name.fetchRecurseSubmodules`
+ *
+ * * GIT_SUBMODULE_RECURSE_NO    - do no recurse into submodules
+ * * GIT_SUBMODULE_RECURSE_YES   - recurse into submodules
+ * * GIT_SUBMODULE_RECURSE_ONDEMAND - recurse into submodules only when
+ *                                    commit not already in local clone
+ */
+typedef enum {
+	GIT_SUBMODULE_RECURSE_NO = 0,
+	GIT_SUBMODULE_RECURSE_YES = 1,
+	GIT_SUBMODULE_RECURSE_ONDEMAND = 2,
+} git_submodule_recurse_t;
+
+/** A type to write in a streaming fashion, for example, for filters. */
+typedef struct git_writestream git_writestream;
+
+struct git_writestream {
+	int (*write)(git_writestream *stream, const char *buffer, size_t len);
+	int (*close)(git_writestream *stream);
+	void (*free)(git_writestream *stream);
+};
+
+/** @} */
+GIT_END_DECL
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/version.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/version.h b/vendor/libgit2-sys/libgit2/include/git2/version.h
new file mode 100644
index 0000000..746bf42
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/version.h
@@ -0,0 +1,18 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_version_h__
+#define INCLUDE_git_version_h__
+
+#define LIBGIT2_VERSION "0.27.0"
+#define LIBGIT2_VER_MAJOR 0
+#define LIBGIT2_VER_MINOR 27
+#define LIBGIT2_VER_REVISION 0
+#define LIBGIT2_VER_PATCH 0
+
+#define LIBGIT2_SOVERSION 27
+
+#endif

vendor/libgit2-sys/libgit2/include/git2/worktree.h

diff --git a/vendor/libgit2-sys/libgit2/include/git2/worktree.h b/vendor/libgit2-sys/libgit2/include/git2/worktree.h
new file mode 100644
index 0000000..d6d4ce5
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/include/git2/worktree.h
@@ -0,0 +1,239 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_worktree_h__
+#define INCLUDE_git_worktree_h__
+
+#include "common.h"
+#include "buffer.h"
+#include "types.h"
+#include "strarray.h"
+
+/**
+ * @file git2/worktrees.h
+ * @brief Git worktree related functions
+ * @defgroup git_commit Git worktree related functions
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * List names of linked working trees
+ *
+ * The returned list should be released with `git_strarray_free`
+ * when no longer needed.
+ *
+ * @param out pointer to the array of working tree names
+ * @param repo the repo to use when listing working trees
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_worktree_list(git_strarray *out, git_repository *repo);
+
+/**
+ * Lookup a working tree by its name for a given repository
+ *
+ * @param out Output pointer to looked up worktree or `NULL`
+ * @param repo The repository containing worktrees
+ * @param name Name of the working tree to look up
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_worktree_lookup(git_worktree **out, git_repository *repo, const char *name);
+
+/**
+ * Open a worktree of a given repository
+ *
+ * If a repository is not the main tree but a worktree, this
+ * function will look up the worktree inside the parent
+ * repository and create a new `git_worktree` structure.
+ *
+ * @param out Out-pointer for the newly allocated worktree
+ * @param repo Repository to look up worktree for
+ */
+GIT_EXTERN(int) git_worktree_open_from_repository(git_worktree **out, git_repository *repo);
+
+/**
+ * Free a previously allocated worktree
+ *
+ * @param wt worktree handle to close. If NULL nothing occurs.
+ */
+GIT_EXTERN(void) git_worktree_free(git_worktree *wt);
+
+/**
+ * Check if worktree is valid
+ *
+ * A valid worktree requires both the git data structures inside
+ * the linked parent repository and the linked working copy to be
+ * present.
+ *
+ * @param wt Worktree to check
+ * @return 0 when worktree is valid, error-code otherwise
+ */
+GIT_EXTERN(int) git_worktree_validate(const git_worktree *wt);
+
+typedef struct git_worktree_add_options {
+	unsigned int version;
+
+	int lock; /**< lock newly created worktree */
+	git_reference *ref; /**< reference to use for the new worktree HEAD */
+} git_worktree_add_options;
+
+#define GIT_WORKTREE_ADD_OPTIONS_VERSION 1
+#define GIT_WORKTREE_ADD_OPTIONS_INIT {GIT_WORKTREE_ADD_OPTIONS_VERSION,0,NULL}
+
+/**
+ * Initializes a `git_worktree_add_options` with default vaules.
+ * Equivalent to creating an instance with
+ * GIT_WORKTREE_ADD_OPTIONS_INIT.
+ *
+ * @param opts the struct to initialize
+ * @param version Verison of struct; pass `GIT_WORKTREE_ADD_OPTIONS_VERSION`
+ * @return Zero on success; -1 on failure.
+ */
+int git_worktree_add_init_options(git_worktree_add_options *opts,
+	unsigned int version);
+
+/**
+ * Add a new working tree
+ *
+ * Add a new working tree for the repository, that is create the
+ * required data structures inside the repository and check out
+ * the current HEAD at `path`
+ *
+ * @param out Output pointer containing new working tree
+ * @param repo Repository to create working tree for
+ * @param name Name of the working tree
+ * @param path Path to create working tree at
+ * @param opts Options to modify default behavior. May be NULL
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_worktree_add(git_worktree **out, git_repository *repo,
+	const char *name, const char *path,
+	const git_worktree_add_options *opts);
+
+/**
+ * Lock worktree if not already locked
+ *
+ * Lock a worktree, optionally specifying a reason why the linked
+ * working tree is being locked.
+ *
+ * @param wt Worktree to lock
+ * @param reason Reason why the working tree is being locked
+ * @return 0 on success, non-zero otherwise
+ */
+GIT_EXTERN(int) git_worktree_lock(git_worktree *wt, const char *reason);
+
+/**
+ * Unlock a locked worktree
+ *
+ * @param wt Worktree to unlock
+ * @return 0 on success, 1 if worktree was not locked, error-code
+ *  otherwise
+ */
+GIT_EXTERN(int) git_worktree_unlock(git_worktree *wt);
+
+/**
+ * Check if worktree is locked
+ *
+ * A worktree may be locked if the linked working tree is stored
+ * on a portable device which is not available.
+ *
+ * @param reason Buffer to store reason in. If NULL no reason is stored.
+ * @param wt Worktree to check
+ * @return 0 when the working tree not locked, a value greater
+ *  than zero if it is locked, less than zero if there was an
+ *  error
+ */
+GIT_EXTERN(int) git_worktree_is_locked(git_buf *reason, const git_worktree *wt);
+
+/**
+ * Retrieve the name of the worktree
+ *
+ * @param wt Worktree to get the name for
+ * @return The worktree's name. The pointer returned is valid for the
+ *  lifetime of the git_worktree
+ */
+GIT_EXTERN(const char *) git_worktree_name(const git_worktree *wt);
+
+/**
+ * Retrieve the filesystem path for the worktree
+ *
+ * @param wt Worktree to get the path for
+ * @return The worktree's filesystem path. The pointer returned
+ *  is valid for the lifetime of the git_worktree.
+ */
+GIT_EXTERN(const char *) git_worktree_path(const git_worktree *wt);
+ 
+/**
+ * Flags which can be passed to git_worktree_prune to alter its
+ * behavior.
+ */
+typedef enum {
+	/* Prune working tree even if working tree is valid */
+	GIT_WORKTREE_PRUNE_VALID = 1u << 0,
+	/* Prune working tree even if it is locked */
+	GIT_WORKTREE_PRUNE_LOCKED = 1u << 1,
+	/* Prune checked out working tree */
+	GIT_WORKTREE_PRUNE_WORKING_TREE = 1u << 2,
+} git_worktree_prune_t;
+
+typedef struct git_worktree_prune_options {
+	unsigned int version;
+
+	uint32_t flags;
+} git_worktree_prune_options;
+
+#define GIT_WORKTREE_PRUNE_OPTIONS_VERSION 1
+#define GIT_WORKTREE_PRUNE_OPTIONS_INIT {GIT_WORKTREE_PRUNE_OPTIONS_VERSION,0}
+
+/**
+ * Initializes a `git_worktree_prune_options` with default vaules.
+ * Equivalent to creating an instance with
+ * GIT_WORKTREE_PRUNE_OPTIONS_INIT.
+ *
+ * @param opts the struct to initialize
+ * @param version Verison of struct; pass `GIT_WORKTREE_PRUNE_OPTIONS_VERSION`
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_worktree_prune_init_options(
+	git_worktree_prune_options *opts,
+	unsigned int version);
+
+/**
+ * Is the worktree prunable with the given options?
+ *
+ * A worktree is not prunable in the following scenarios:
+ *
+ * - the worktree is linking to a valid on-disk worktree. The
+ *   `valid` member will cause this check to be ignored.
+ * - the worktree is locked. The `locked` flag will cause this
+ *   check to be ignored.
+ *
+ * If the worktree is not valid and not locked or if the above
+ * flags have been passed in, this function will return a
+ * positive value.
+ */
+GIT_EXTERN(int) git_worktree_is_prunable(git_worktree *wt,
+	git_worktree_prune_options *opts);
+
+/**
+ * Prune working tree
+ *
+ * Prune the working tree, that is remove the git data
+ * structures on disk. The repository will only be pruned of
+ * `git_worktree_is_prunable` succeeds.
+ *
+ * @param wt Worktree to prune
+ * @param opts Specifies which checks to override. See
+ *        `git_worktree_is_prunable`. May be NULL
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_worktree_prune(git_worktree *wt,
+	git_worktree_prune_options *opts);
+
+/** @} */
+GIT_END_DECL
+#endif

vendor/libgit2-sys/libgit2/libgit2.pc.in

diff --git a/vendor/libgit2-sys/libgit2/libgit2.pc.in b/vendor/libgit2-sys/libgit2/libgit2.pc.in
new file mode 100644
index 0000000..96b9659
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/libgit2.pc.in
@@ -0,0 +1,13 @@
+prefix="@PKGCONFIG_PREFIX@"
+libdir=@PKGCONFIG_LIBDIR@
+includedir=@PKGCONFIG_INCLUDEDIR@
+
+Name: libgit2
+Description: The git library, take 2
+Version: @LIBGIT2_VERSION_STRING@
+
+Libs: -L${libdir} -lgit2
+Libs.private: @LIBGIT2_PC_LIBS@
+Requires.private: @LIBGIT2_PC_REQUIRES@
+
+Cflags: -I${includedir}

vendor/libgit2-sys/libgit2/libgit2_clar.supp

diff --git a/vendor/libgit2-sys/libgit2/libgit2_clar.supp b/vendor/libgit2-sys/libgit2/libgit2_clar.supp
new file mode 100644
index 0000000..bd22ada
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/libgit2_clar.supp
@@ -0,0 +1,49 @@
+{
+	ignore-zlib-errors-cond
+	Memcheck:Cond
+	obj:*libz.so*
+}
+
+{
+	ignore-giterr-set-leak
+	Memcheck:Leak
+	...
+	fun:giterr_set
+}
+
+{
+	ignore-git-global-state-leak
+	Memcheck:Leak
+	...
+	fun:git__global_state
+}
+
+{
+	ignore-openssl-ssl-leak
+	Memcheck:Leak
+	...
+	obj:*libssl.so*
+	...
+}
+
+{
+	ignore-openssl-crypto-leak
+	Memcheck:Leak
+	...
+	obj:*libcrypto.so*
+	...
+}
+
+{
+	ignore-openssl-crypto-cond
+	Memcheck:Cond
+	obj:*libcrypto.so*
+	...
+}
+
+{
+	ignore-glibc-getaddrinfo-cache
+	Memcheck:Leak
+	...
+	fun:__check_pf
+}

vendor/libgit2-sys/libgit2/script/appveyor-mingw.sh

diff --git a/vendor/libgit2-sys/libgit2/script/appveyor-mingw.sh b/vendor/libgit2-sys/libgit2/script/appveyor-mingw.sh
new file mode 100755
index 0000000..6b2a942
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/script/appveyor-mingw.sh
@@ -0,0 +1,23 @@
+#!/bin/sh
+set -e
+cd `dirname "$0"`/..
+if [ "$ARCH" = "i686" ]; then
+  f=i686-4.9.2-release-win32-sjlj-rt_v3-rev1.7z
+  if ! [ -e $f ]; then
+    curl -LsSO http://sourceforge.net/projects/mingw-w64/files/Toolchains%20targetting%20Win32/Personal%20Builds/mingw-builds/4.9.2/threads-win32/sjlj/$f
+  fi
+  7z x $f > /dev/null
+  export PATH=`pwd`/mingw32/bin:$PATH
+else
+  f=x86_64-4.9.2-release-win32-seh-rt_v3-rev1.7z
+  if ! [ -e $f ]; then
+    curl -LsSO http://sourceforge.net/projects/mingw-w64/files/Toolchains%20targetting%20Win64/Personal%20Builds/mingw-builds/4.9.2/threads-win32/seh/$f
+  fi
+  7z x $f > /dev/null
+  export PATH=`pwd`/mingw64/bin:$PATH
+fi
+cd build
+gcc --version
+cmake --version
+cmake -D ENABLE_TRACE=ON -D BUILD_CLAR=ON -D BUILD_EXAMPLES=ON .. -G"$GENERATOR"
+cmake --build . --config RelWithDebInfo

vendor/libgit2-sys/libgit2/script/backport.sh

diff --git a/vendor/libgit2-sys/libgit2/script/backport.sh b/vendor/libgit2-sys/libgit2/script/backport.sh
new file mode 100755
index 0000000..3c2f899
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/script/backport.sh
@@ -0,0 +1,23 @@
+#!/bin/sh
+
+if test $# -eq 0
+then
+    echo "USAGE: $0 <#PR> [<#PR>...]"
+    exit
+fi
+
+commits=
+
+for pr in $*
+do
+    mergecommit=$(git rev-parse ":/Merge pull request #$pr" || exit 1)
+    mergebase=$(git merge-base "$mergecommit"^1 "$mergecommit"^2 || exit 1)
+
+    commits="$commits $(git rev-list --reverse "$mergecommit"^2 ^"$mergebase")"
+done
+
+echo "Cherry-picking the following commits:"
+git rev-list --no-walk --oneline $commits
+echo
+
+git cherry-pick $commits

vendor/libgit2-sys/libgit2/script/cibuild.sh

diff --git a/vendor/libgit2-sys/libgit2/script/cibuild.sh b/vendor/libgit2-sys/libgit2/script/cibuild.sh
new file mode 100755
index 0000000..5d70e75
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/script/cibuild.sh
@@ -0,0 +1,102 @@
+#!/bin/sh
+
+set -x
+
+if [ -n "$COVERITY" ];
+then
+	./script/coverity.sh;
+	exit $?;
+fi
+
+if [ "$TRAVIS_OS_NAME" = "osx" ]; then
+	export PKG_CONFIG_PATH=$(ls -d /usr/local/Cellar/{curl,zlib}/*/lib/pkgconfig | paste -s -d':' -)
+
+	# Set up a ramdisk for us to put our test data on to speed up tests on macOS
+	export CLAR_TMP="$HOME"/_clar_tmp
+	mkdir -p $CLAR_TMP
+
+	# 5*2M sectors aka ~5GB of space
+	device=$(hdiutil attach -nomount ram://$((5 * 2 * 1024 * 1024)))
+	newfs_hfs $device
+	mount -t hfs $device $CLAR_TMP
+fi
+
+# Should we ask Travis to cache this file?
+curl -L https://github.com/ethomson/poxyproxy/releases/download/v0.1.0/poxyproxy-0.1.0.jar >poxyproxy.jar || exit $?
+# Run this early so we know it's ready by the time we need it
+java -jar poxyproxy.jar -d --port 8080 --credentials foo:bar &
+
+mkdir _build
+cd _build
+# shellcheck disable=SC2086
+cmake .. -DBUILD_EXAMPLES=ON -DCMAKE_INSTALL_PREFIX=../_install $OPTIONS || exit $?
+make -j2 install || exit $?
+
+# If this platform doesn't support test execution, bail out now
+if [ -n "$SKIP_TESTS" ];
+then
+	exit $?;
+fi
+
+# Create a test repo which we can use for the online::push tests
+mkdir "$HOME"/_temp
+git init --bare "$HOME"/_temp/test.git
+git daemon --listen=localhost --export-all --enable=receive-pack --base-path="$HOME"/_temp "$HOME"/_temp 2>/dev/null &
+export GITTEST_REMOTE_URL="git://localhost/test.git"
+
+# Run the test suite
+ctest -V -R libgit2_clar || exit $?
+
+# Now that we've tested the raw git protocol, let's set up ssh to we
+# can do the push tests over it
+
+killall git-daemon
+
+# Set up sshd
+mkdir ~/sshd/
+cat >~/sshd/sshd_config<<-EOF
+	Port 2222
+	ListenAddress 0.0.0.0
+	Protocol 2
+	HostKey ${HOME}/sshd/id_rsa
+	PidFile ${HOME}/sshd/pid
+	RSAAuthentication yes
+	PasswordAuthentication yes
+	PubkeyAuthentication yes
+	ChallengeResponseAuthentication no
+	# Required here as sshd will simply close connection otherwise
+	UsePAM no
+EOF
+ssh-keygen -t rsa -f ~/sshd/id_rsa -N "" -q
+/usr/sbin/sshd -f ~/sshd/sshd_config
+
+# Set up keys
+ssh-keygen -t rsa -f ~/.ssh/id_rsa -N "" -q
+cat ~/.ssh/id_rsa.pub >>~/.ssh/authorized_keys
+while read algorithm key comment; do
+    echo "[localhost]:2222 $algorithm $key" >>~/.ssh/known_hosts
+done <~/sshd/id_rsa.pub
+
+# Get the fingerprint for localhost and remove the colons so we can parse it as
+# a hex number. The Mac version is newer so it has a different output format.
+if [ "$TRAVIS_OS_NAME" = "osx" ]; then
+    export GITTEST_REMOTE_SSH_FINGERPRINT=$(ssh-keygen -E md5 -F '[localhost]:2222' -l | tail -n 1 | cut -d ' ' -f 3 | cut -d : -f2- | tr -d :)
+else
+    export GITTEST_REMOTE_SSH_FINGERPRINT=$(ssh-keygen -F '[localhost]:2222' -l | tail -n 1 | cut -d ' ' -f 2 | tr -d ':')
+fi
+
+# Use the SSH server
+export GITTEST_REMOTE_URL="ssh://localhost:2222/$HOME/_temp/test.git"
+export GITTEST_REMOTE_USER=$USER
+export GITTEST_REMOTE_SSH_KEY="$HOME/.ssh/id_rsa"
+export GITTEST_REMOTE_SSH_PUBKEY="$HOME/.ssh/id_rsa.pub"
+export GITTEST_REMOTE_SSH_PASSPHRASE=""
+ctest -V -R libgit2_clar-ssh || exit $?
+
+# Use the proxy we started at the beginning
+export GITTEST_REMOTE_PROXY_URL="localhost:8080"
+export GITTEST_REMOTE_PROXY_USER="foo"
+export GITTEST_REMOTE_PROXY_PASS="bar"
+ctest -V -R libgit2_clar-proxy_credentials || exit $?
+
+kill $(cat "$HOME/sshd/pid")

vendor/libgit2-sys/libgit2/script/coverity.sh

diff --git a/vendor/libgit2-sys/libgit2/script/coverity.sh b/vendor/libgit2-sys/libgit2/script/coverity.sh
new file mode 100755
index 0000000..5fe16c0
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/script/coverity.sh
@@ -0,0 +1,71 @@
+#!/bin/bash
+set -e
+
+# Only run this on our branches
+echo "Branch: $TRAVIS_BRANCH  |  Pull request: $TRAVIS_PULL_REQUEST  |  Slug: $TRAVIS_REPO_SLUG"
+if [ "$TRAVIS_BRANCH" != "master" -o "$TRAVIS_PULL_REQUEST" != "false" -o "$TRAVIS_REPO_SLUG" != "libgit2/libgit2" ];
+then
+	echo "Only analyzing the 'master' brach of the main repository."
+	exit 0
+fi
+
+# Environment check
+[ -z "$COVERITY_TOKEN" ] && echo "Need to set a coverity token" && exit 1
+
+case $(uname -m) in
+	i?86)				BITS=32 ;;
+	amd64|x86_64)	BITS=64 ;;
+esac
+SCAN_TOOL=https://scan.coverity.com/download/cxx/linux${BITS}
+TOOL_BASE=$(pwd)/_coverity-scan
+
+# Install coverity tools
+if [ ! -d "$TOOL_BASE" ]; then
+	echo "Downloading coverity..."
+	mkdir -p "$TOOL_BASE"
+	pushd "$TOOL_BASE"
+	wget -O coverity_tool.tgz $SCAN_TOOL \
+		--post-data "project=libgit2&token=$COVERITY_TOKEN"
+	tar xzf coverity_tool.tgz
+	popd
+	TOOL_DIR=$(find "$TOOL_BASE" -type d -name 'cov-analysis*')
+	ln -s "$TOOL_DIR" "$TOOL_BASE"/cov-analysis
+fi
+
+cp script/user_nodefs.h "$TOOL_BASE"/cov-analysis/config/user_nodefs.h
+
+COV_BUILD="$TOOL_BASE/cov-analysis/bin/cov-build"
+
+# Configure and build
+rm -rf _build
+mkdir _build
+cd _build
+cmake .. -DTHREADSAFE=ON
+COVERITY_UNSUPPORTED=1 \
+	$COV_BUILD --dir cov-int \
+	cmake --build .
+
+# Upload results
+tar czf libgit2.tgz cov-int
+SHA=$(git rev-parse --short HEAD)
+
+HTML="$(curl \
+	--silent \
+	--write-out "\n%{http_code}" \
+	--form token="$COVERITY_TOKEN" \
+	--form email=bs@github.com \
+	--form file=@libgit2.tgz \
+	--form version="$SHA" \
+	--form description="Travis build" \
+	https://scan.coverity.com/builds?project=libgit2)"
+# Body is everything up to the last line
+BODY="$(echo "$HTML" | head -n-1)"
+# Status code is the last line
+STATUS_CODE="$(echo "$HTML" | tail -n1)"
+
+echo "${BODY}"
+
+if [ "${STATUS_CODE}" != "201" ]; then
+	echo "Received error code ${STATUS_CODE} from Coverity"
+	exit 1
+fi

vendor/libgit2-sys/libgit2/script/install-deps-linux.sh

diff --git a/vendor/libgit2-sys/libgit2/script/install-deps-linux.sh b/vendor/libgit2-sys/libgit2/script/install-deps-linux.sh
new file mode 100755
index 0000000..99cbde4
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/script/install-deps-linux.sh
@@ -0,0 +1,13 @@
+#!/bin/sh
+
+set -x
+
+if [ "$MBEDTLS" ]; then
+  git clone --depth 10 --single-branch --branch mbedtls-2.6.1 https://github.com/ARMmbed/mbedtls.git ./deps/mbedtls
+  cd ./deps/mbedtls
+  # We pass -fPIC explicitely because we'll include it in libgit2.so
+  CFLAGS=-fPIC cmake -DENABLE_PROGRAMS=OFF -DENABLE_TESTING=OFF -DUSE_SHARED_MBEDTLS_LIBRARY=OFF -DUSE_STATIC_MBEDTLS_LIBRARY=ON .
+  cmake --build .
+
+  echo "mbedTLS built in `pwd`"
+fi

vendor/libgit2-sys/libgit2/script/install-deps-osx.sh

diff --git a/vendor/libgit2-sys/libgit2/script/install-deps-osx.sh b/vendor/libgit2-sys/libgit2/script/install-deps-osx.sh
new file mode 100755
index 0000000..94314db
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/script/install-deps-osx.sh
@@ -0,0 +1,9 @@
+#!/bin/sh
+
+set -x
+
+brew update
+brew install zlib
+brew install curl
+brew install openssl
+brew install libssh2

vendor/libgit2-sys/libgit2/script/user_model.c

diff --git a/vendor/libgit2-sys/libgit2/script/user_model.c b/vendor/libgit2-sys/libgit2/script/user_model.c
new file mode 100644
index 0000000..a933d73
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/script/user_model.c
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+void *realloc(void *ptr, size_t size);
+void *memmove(void *dest, const void *src, size_t n);
+size_t strlen(const char *s);
+
+typedef struct va_list_str *va_list;
+
+typedef struct git_vector {
+	void **contents;
+	size_t length;
+} git_vector;
+
+typedef struct git_buf {
+	char *ptr;
+	size_t asize, size;
+} git_buf;
+
+int git_vector_insert(git_vector *v, void *element)
+{
+	if (!v)
+		__coverity_panic__();
+
+	v->contents = realloc(v->contents, ++v->length);
+	if (!v->contents)
+		__coverity_panic__();
+	v->contents[v->length] = element;
+
+	return 0;
+}
+
+int git_buf_len(const struct git_buf *buf)
+{
+	return strlen(buf->ptr);
+}
+
+int git_buf_vprintf(git_buf *buf, const char *format, va_list ap)
+{
+    char ch, *s;
+    size_t len;
+
+    __coverity_string_null_sink__(format);
+    __coverity_string_size_sink__(format);
+
+    ch = *format;
+    ch = *(char *)ap;
+
+    buf->ptr = __coverity_alloc__(len);
+    __coverity_writeall__(buf->ptr);
+    buf->size = len;
+
+    return 0;
+}
+
+int git_buf_put(git_buf *buf, const char *data, size_t len)
+{
+    buf->ptr = __coverity_alloc__(buf->size + len + 1);
+    memmove(buf->ptr + buf->size, data, len);
+    buf->size += len;
+    buf->ptr[buf->size + len] = 0;
+    return 0;
+}
+
+int git_buf_set(git_buf *buf, const void *data, size_t len)
+{
+    buf->ptr = __coverity_alloc__(len + 1);
+    memmove(buf->ptr, data, len);
+    buf->size = len + 1;
+    return 0;
+}

vendor/libgit2-sys/libgit2/script/user_nodefs.h

diff --git a/vendor/libgit2-sys/libgit2/script/user_nodefs.h b/vendor/libgit2-sys/libgit2/script/user_nodefs.h
new file mode 100644
index 0000000..3c06a70
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/script/user_nodefs.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#nodef GITERR_CHECK_ALLOC(ptr) if (ptr == NULL) { __coverity_panic__(); }
+#nodef GITERR_CHECK_ALLOC_BUF(buf) if (buf == NULL || git_buf_oom(buf)) { __coverity_panic__(); }
+
+#nodef GITERR_CHECK_ALLOC_ADD(out, one, two) \
+	if (GIT_ADD_SIZET_OVERFLOW(out, one, two)) { __coverity_panic__(); }
+
+#nodef GITERR_CHECK_ALLOC_ADD3(out, one, two, three) \
+	if (GIT_ADD_SIZET_OVERFLOW(out, one, two) || \
+		GIT_ADD_SIZET_OVERFLOW(out, *(out), three)) { __coverity_panic__(); }
+
+#nodef GITERR_CHECK_ALLOC_ADD4(out, one, two, three, four) \
+	if (GIT_ADD_SIZET_OVERFLOW(out, one, two) || \
+		GIT_ADD_SIZET_OVERFLOW(out, *(out), three) || \
+		GIT_ADD_SIZET_OVERFLOW(out, *(out), four)) { __coverity_panic__(); }
+
+#nodef GITERR_CHECK_ALLOC_MULTIPLY(out, nelem, elsize) \
+	if (GIT_MULTIPLY_SIZET_OVERFLOW(out, nelem, elsize)) { __coverity_panic__(); }
+
+#nodef GITERR_CHECK_VERSION(S,V,N) if (giterr__check_version(S,V,N) < 0)  { __coverity_panic__(); }
+
+#nodef LOOKS_LIKE_DRIVE_PREFIX(S) (strlen(S) >= 2 && git__isalpha((S)[0]) && (S)[1] == ':')
+
+#nodef git_vector_foreach(v, iter, elem)	\
+	for ((iter) = 0; (v)->contents != NULL && (iter) < (v)->length && ((elem) = (v)->contents[(iter)], 1); (iter)++ )
+
+#nodef git_vector_rforeach(v, iter, elem)	\
+	for ((iter) = (v)->length - 1; (v)->contents != NULL && (iter) < SIZE_MAX && ((elem) = (v)->contents[(iter)], 1); (iter)-- )

vendor/libgit2-sys/libgit2/src/CMakeLists.txt

diff --git a/vendor/libgit2-sys/libgit2/src/CMakeLists.txt b/vendor/libgit2-sys/libgit2/src/CMakeLists.txt
new file mode 100644
index 0000000..2b82bb3
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/CMakeLists.txt
@@ -0,0 +1,515 @@
+IF(DEBUG_POOL)
+	SET(GIT_DEBUG_POOL 1)
+ENDIF()
+ADD_FEATURE_INFO(debugpool GIT_DEBUG_POOL "debug pool allocator")
+
+# This variable will contain the libraries we need to put into
+# libgit2.pc's Requires.private. That is, what we're linking to or
+# what someone who's statically linking us needs to link to.
+SET(LIBGIT2_PC_REQUIRES "")
+# This will be set later if we use the system's http-parser library or
+# use iconv (OSX) and will be written to the Libs.private field in the
+# pc file.
+SET(LIBGIT2_PC_LIBS "")
+
+SET(LIBGIT2_INCLUDES
+	"${CMAKE_CURRENT_BINARY_DIR}"
+	"${libgit2_SOURCE_DIR}/src"
+	"${libgit2_SOURCE_DIR}/include")
+SET(LIBGIT2_LIBS "")
+
+# Installation paths
+#
+SET(BIN_INSTALL_DIR bin CACHE PATH "Where to install binaries to.")
+SET(LIB_INSTALL_DIR lib CACHE PATH "Where to install libraries to.")
+SET(INCLUDE_INSTALL_DIR include CACHE PATH "Where to install headers to.")
+
+# Set a couple variables to be substituted inside the .pc file.
+# We can't just use LIB_INSTALL_DIR in the .pc file, as passing them as absolue
+# or relative paths is both valid and supported by cmake.
+SET (PKGCONFIG_PREFIX ${CMAKE_INSTALL_PREFIX})
+
+IF(IS_ABSOLUTE ${LIB_INSTALL_DIR})
+  SET (PKGCONFIG_LIBDIR ${LIB_INSTALL_DIR})
+ELSE(IS_ABSOLUTE ${LIB_INSTALL_DIR})
+  SET (PKGCONFIG_LIBDIR "\${prefix}/${LIB_INSTALL_DIR}")
+ENDIF (IS_ABSOLUTE ${LIB_INSTALL_DIR})
+
+IF(IS_ABSOLUTE ${INCLUDE_INSTALL_DIR})
+  SET (PKGCONFIG_INCLUDEDIR ${INCLUDE_INSTALL_DIR})
+ELSE(IS_ABSOLUTE ${INCLUDE_INSTALL_DIR})
+  SET (PKGCONFIG_INCLUDEDIR "\${prefix}/${INCLUDE_INSTALL_DIR}")
+ENDIF(IS_ABSOLUTE ${INCLUDE_INSTALL_DIR})
+
+# Enable tracing
+IF (ENABLE_TRACE STREQUAL "ON")
+	SET(GIT_TRACE 1)
+ENDIF()
+ADD_FEATURE_INFO(tracing GIT_TRACE "tracing support")
+
+CHECK_SYMBOL_EXISTS(regcomp_l "regex.h;xlocale.h" HAVE_REGCOMP_L)
+IF (HAVE_REGCOMP_L)
+	SET(GIT_USE_REGCOMP_L 1)
+ENDIF ()
+
+CHECK_FUNCTION_EXISTS(futimens HAVE_FUTIMENS)
+IF (HAVE_FUTIMENS)
+	SET(GIT_USE_FUTIMENS 1)
+ENDIF ()
+
+CHECK_FUNCTION_EXISTS(qsort_r HAVE_QSORT_R)
+IF (HAVE_QSORT_R)
+	ADD_DEFINITIONS(-DHAVE_QSORT_R)
+ENDIF ()
+
+CHECK_FUNCTION_EXISTS(qsort_s HAVE_QSORT_S)
+IF (HAVE_QSORT_S)
+	ADD_DEFINITIONS(-DHAVE_QSORT_S)
+ENDIF ()
+
+# Find required dependencies
+
+IF(WIN32)
+	LIST(APPEND LIBGIT2_LIBS ws2_32)
+ELSEIF(CMAKE_SYSTEM_NAME MATCHES "(Solaris|SunOS)")
+	LIST(APPEND LIBGIT2_LIBS socket nsl)
+	LIST(APPEND LIBGIT2_PC_LIBS "-lsocket" "-lnsl")
+ELSEIF(CMAKE_SYSTEM_NAME MATCHES "Haiku")
+	LIST(APPEND LIBGIT2_LIBS network)
+	LIST(APPEND LIBGIT2_PC_LIBS "-lnetwork")
+ENDIF()
+
+CHECK_LIBRARY_EXISTS(rt clock_gettime "time.h" NEED_LIBRT)
+IF(NEED_LIBRT)
+	LIST(APPEND LIBGIT2_LIBS rt)
+	LIST(APPEND LIBGIT2_PC_LIBS "-lrt")
+ENDIF()
+
+IF(THREADSAFE)
+	LIST(APPEND LIBGIT2_LIBS ${CMAKE_THREAD_LIBS_INIT})
+	LIST(APPEND LIBGIT2_PC_LIBS ${CMAKE_THREAD_LIBS_INIT})
+ENDIF()
+ADD_FEATURE_INFO(threadsafe THREADSAFE "threadsafe support")
+
+
+IF (WIN32 AND EMBED_SSH_PATH)
+	FILE(GLOB SRC_SSH "${EMBED_SSH_PATH}/src/*.c")
+	LIST(APPEND LIBGIT2_INCLUDES "${EMBED_SSH_PATH}/include")
+	FILE(WRITE "${EMBED_SSH_PATH}/src/libssh2_config.h" "#define HAVE_WINCNG\n#define LIBSSH2_WINCNG\n#include \"../win32/libssh2_config.h\"")
+	SET(GIT_SSH 1)
+ENDIF()
+
+IF (WIN32 AND WINHTTP)
+	SET(GIT_WINHTTP 1)
+
+	# Since MinGW does not come with headers or an import library for winhttp,
+	# we have to include a private header and generate our own import library
+	IF (MINGW)
+		ADD_SUBDIRECTORY("${libgit2_SOURCE_DIR}/deps/winhttp" "${libgit2_BINARY_DIR}/deps/winhttp")
+		LIST(APPEND LIBGIT2_LIBS winhttp)
+		LIST(APPEND LIBGIT2_INCLUDES "${libgit2_SOURCE_DIR}/deps/winhttp")
+	ELSE()
+		LIST(APPEND LIBGIT2_LIBS "winhttp")
+		LIST(APPEND LIBGIT2_PC_LIBS "-lwinhttp")
+	ENDIF ()
+
+	LIST(APPEND LIBGIT2_LIBS "rpcrt4" "crypt32" "ole32")
+	LIST(APPEND LIBGIT2_PC_LIBS "-lrpcrt4" "-lcrypt32" "-lole32")
+ELSE ()
+	IF (CURL)
+		FIND_PKGLIBRARIES(CURL libcurl)
+	ENDIF ()
+	IF (CURL_FOUND)
+		SET(GIT_CURL 1)
+		LIST(APPEND LIBGIT2_INCLUDES ${CURL_INCLUDE_DIRS})
+		LIST(APPEND LIBGIT2_LIBS ${CURL_LIBRARIES})
+		LIST(APPEND LIBGIT2_PC_LIBS ${CURL_LDFLAGS})
+	ENDIF()
+	ADD_FEATURE_INFO(cURL GIT_CURL "cURL for HTTP proxy support")
+ENDIF()
+
+IF (USE_HTTPS)
+	# We try to find any packages our backends might use
+	FIND_PACKAGE(OpenSSL)
+	FIND_PACKAGE(mbedTLS)
+	IF (CMAKE_SYSTEM_NAME MATCHES "Darwin")
+		FIND_PACKAGE(Security)
+		FIND_PACKAGE(CoreFoundation)
+	ENDIF()
+
+	# Auto-select TLS backend
+	IF (USE_HTTPS STREQUAL ON)
+		IF (SECURITY_FOUND)
+			IF (SECURITY_HAS_SSLCREATECONTEXT)
+				SET(HTTPS_BACKEND "SecureTransport")
+			ELSE()
+				MESSAGE("-- Security framework is too old, falling back to OpenSSL")
+				SET(HTTPS_BACKEND "OpenSSL")
+			ENDIF()
+		ELSEIF (WINHTTP)
+			SET(HTTPS_BACKEND "WinHTTP")
+		ELSEIF(OPENSSL_FOUND)
+			SET(HTTPS_BACKEND "OpenSSL")
+		ELSEIF(MBEDTLS_FOUND)
+			SET(HTTPS_BACKEND "mbedTLS")
+		ELSE()
+			MESSAGE(FATAL_ERROR "Unable to autodetect a usable HTTPS backend."
+				"Please pass the backend name explicitly (-DUSE_HTTPS=backend)")
+		ENDIF()
+	ELSE()
+		# Backend was explicitly set
+		SET(HTTPS_BACKEND ${USE_HTTPS})
+	ENDIF()
+
+	# Check that we can find what's required for the selected backend
+	IF (HTTPS_BACKEND STREQUAL "SecureTransport")
+		IF (NOT COREFOUNDATION_FOUND)
+			MESSAGE(FATAL_ERROR "Cannot use SecureTransport backend, CoreFoundation.framework not found")
+		ENDIF()
+		IF (NOT SECURITY_FOUND)
+			MESSAGE(FATAL_ERROR "Cannot use SecureTransport backend, Security.framework not found")
+		ENDIF()
+		IF (NOT SECURITY_HAS_SSLCREATECONTEXT)
+			MESSAGE(FATAL_ERROR "Cannot use SecureTransport backend, SSLCreateContext not supported")
+		ENDIF()
+
+		SET(GIT_SECURE_TRANSPORT 1)
+		LIST(APPEND LIBGIT2_INCLUDES ${SECURITY_INCLUDE_DIR})
+		LIST(APPEND LIBGIT2_LIBS ${COREFOUNDATION_LIBRARIES} ${SECURITY_LIBRARIES})
+		LIST(APPEND LIBGIT2_PC_LIBS ${COREFOUNDATION_LDFLAGS} ${SECURITY_LDFLAGS})
+	ELSEIF (HTTPS_BACKEND STREQUAL "OpenSSL")
+		IF (NOT OPENSSL_FOUND)
+			MESSAGE(FATAL_ERROR "Asked for OpenSSL TLS backend, but it wasn't found")
+		ENDIF()
+
+		SET(GIT_OPENSSL 1)
+		LIST(APPEND LIBGIT2_INCLUDES ${OPENSSL_INCLUDE_DIR})
+		LIST(APPEND LIBGIT2_LIBS ${OPENSSL_LIBRARIES})
+		LIST(APPEND LIBGIT2_PC_LIBS ${OPENSSL_LDFLAGS})
+		LIST(APPEND LIBGIT2_PC_REQUIRES "openssl")
+	ELSEIF(HTTPS_BACKEND STREQUAL "mbedTLS")
+		IF (NOT MBEDTLS_FOUND)
+			MESSAGE(FATAL_ERROR "Asked for mbedTLS backend, but it wasn't found")
+		ENDIF()
+
+		IF(NOT CERT_LOCATION)
+			MESSAGE("Auto-detecting default certificates location")
+			IF(CMAKE_SYSTEM_NAME MATCHES Darwin)
+				# Check for an Homebrew installation
+				SET(OPENSSL_CMD "/usr/local/opt/openssl/bin/openssl")
+			ELSE()
+				SET(OPENSSL_CMD "openssl")
+			ENDIF()
+			EXECUTE_PROCESS(COMMAND ${OPENSSL_CMD} version -d OUTPUT_VARIABLE OPENSSL_DIR OUTPUT_STRIP_TRAILING_WHITESPACE)
+			IF(OPENSSL_DIR)
+				STRING(REGEX REPLACE "^OPENSSLDIR: \"(.*)\"$" "\\1/" OPENSSL_DIR ${OPENSSL_DIR})
+
+				SET(OPENSSL_CA_LOCATIONS
+					"ca-bundle.pem"             # OpenSUSE Leap 42.1
+					"cert.pem"                  # Ubuntu 14.04, FreeBSD
+					"certs/ca-certificates.crt" # Ubuntu 16.04
+					"certs/ca.pem"              # Debian 7
+				)
+				FOREACH(SUFFIX IN LISTS OPENSSL_CA_LOCATIONS)
+					SET(LOC "${OPENSSL_DIR}${SUFFIX}")
+					IF(NOT CERT_LOCATION AND EXISTS "${OPENSSL_DIR}${SUFFIX}")
+						SET(CERT_LOCATION ${LOC})
+					ENDIF()
+				ENDFOREACH()
+			ELSE()
+				MESSAGE("Unable to find OpenSSL executable. Please provide default certificate location via CERT_LOCATION")
+			ENDIF()
+		ENDIF()
+
+		IF(CERT_LOCATION)
+			IF(NOT EXISTS ${CERT_LOCATION})
+				MESSAGE(FATAL_ERROR "Cannot use CERT_LOCATION=${CERT_LOCATION} as it doesn't exist")
+			ENDIF()
+			ADD_FEATURE_INFO(CERT_LOCATION ON "using certificates from ${CERT_LOCATION}")
+			ADD_DEFINITIONS(-DGIT_DEFAULT_CERT_LOCATION="${CERT_LOCATION}")
+		ENDIF()
+
+		SET(GIT_MBEDTLS 1)
+		LIST(APPEND LIBGIT2_INCLUDES ${MBEDTLS_INCLUDE_DIR})
+		LIST(APPEND LIBGIT2_LIBS ${MBEDTLS_LIBRARIES})
+		# mbedTLS has no pkgconfig file, hence we can't require it
+		# https://github.com/ARMmbed/mbedtls/issues/228
+		# For now, pass its link flags as our own
+		LIST(APPEND LIBGIT2_PC_LIBS ${MBEDTLS_LIBRARIES})
+	ELSEIF (HTTPS_BACKEND STREQUAL "WinHTTP")
+		# WinHTTP setup was handled in the WinHTTP-specific block above
+	ELSE()
+		MESSAGE(FATAL_ERROR "Asked for backend ${HTTPS_BACKEND} but it wasn't found")
+	ENDIF()
+
+	ADD_FEATURE_INFO(HTTPS ON "using ${HTTPS_BACKEND}")
+	SET(GIT_HTTPS 1)
+ELSE()
+	ADD_FEATURE_INFO(HTTPS OFF "no support")
+ENDIF()
+
+# Specify sha1 implementation
+IF(SHA1_BACKEND STREQUAL "OpenSSL")
+	IF(NOT OPENSSL_FOUND)
+		FIND_PACKAGE(OpenSSL)
+		IF(NOT OPENSSL_FOUND)
+		    MESSAGE(FATAL_ERROR "Requested OpenSSL SHA1 backend, but OpenSSL could not be found")
+		ENDIF()
+	ENDIF()
+
+	ADD_FEATURE_INFO(SHA ON "using OpenSSL")
+	SET(GIT_SHA1_OPENSSL 1)
+	IF(CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
+		LIST(APPEND LIBGIT2_PC_LIBS "-lssl")
+	ELSE()
+		LIST(APPEND LIBGIT2_PC_REQUIRES "openssl")
+	ENDIF()
+ELSEIF(SHA1_BACKEND STREQUAL "CollisionDetection")
+	ADD_FEATURE_INFO(SHA ON "using CollisionDetection")
+	SET(GIT_SHA1_COLLISIONDETECT 1)
+	ADD_DEFINITIONS(-DSHA1DC_NO_STANDARD_INCLUDES=1)
+	ADD_DEFINITIONS(-DSHA1DC_CUSTOM_INCLUDE_SHA1_C=\"common.h\")
+	ADD_DEFINITIONS(-DSHA1DC_CUSTOM_INCLUDE_UBC_CHECK_C=\"common.h\")
+	FILE(GLOB SRC_SHA1 hash/hash_collisiondetect.c hash/sha1dc/*)
+ELSEIF(SHA1_BACKEND STREQUAL "Generic")
+	ADD_FEATURE_INFO(SHA ON "using Generic")
+	FILE(GLOB SRC_SHA1 hash/hash_generic.c)
+ELSEIF(SHA1_BACKEND STREQUAL "Win32")
+	ADD_FEATURE_INFO(SHA ON "using Win32")
+	SET(GIT_SHA1_WIN32 1)
+	FILE(GLOB SRC_SHA1 hash/hash_win32.c)
+ELSEIF(SHA1_BACKEND STREQUAL "CommonCrypto")
+	ADD_FEATURE_INFO(SHA ON "using CommonCrypto")
+	SET(GIT_SHA1_COMMON_CRYPTO 1)
+ELSEIF (SHA1_BACKEND STREQUAL "mbedTLS")
+	ADD_FEATURE_INFO(SHA ON "using mbedTLS")
+	SET(GIT_SHA1_MBEDTLS 1)
+	FILE(GLOB SRC_SHA1 src/hash/hash_mbedtls.c)
+	LIST(APPEND LIBGIT2_PC_REQUIRES "mbedtls")
+ELSE()
+	MESSAGE(FATAL_ERROR "Asked for unknown SHA1 backend ${SHA1_BACKEND}")
+ENDIF()
+
+# Include POSIX regex when it is required
+IF(WIN32 OR AMIGA OR CMAKE_SYSTEM_NAME MATCHES "(Solaris|SunOS)")
+	ADD_SUBDIRECTORY("${libgit2_SOURCE_DIR}/deps/regex" "${libgit2_BINARY_DIR}/deps/regex")
+	LIST(APPEND LIBGIT2_INCLUDES "${libgit2_SOURCE_DIR}/deps/regex")
+	LIST(APPEND LIBGIT2_OBJECTS $<TARGET_OBJECTS:regex>)
+ENDIF()
+
+# Optional external dependency: http-parser
+FIND_PACKAGE(HTTP_Parser)
+IF (USE_EXT_HTTP_PARSER AND HTTP_PARSER_FOUND AND HTTP_PARSER_VERSION_MAJOR EQUAL 2)
+	LIST(APPEND LIBGIT2_INCLUDES ${HTTP_PARSER_INCLUDE_DIRS})
+	LIST(APPEND LIBGIT2_LIBS ${HTTP_PARSER_LIBRARIES})
+	LIST(APPEND LIBGIT2_PC_LIBS "-lhttp_parser")
+	ADD_FEATURE_INFO(http-parser ON "http-parser support")
+ELSE()
+	MESSAGE(STATUS "http-parser version 2 was not found or disabled; using bundled 3rd-party sources.")
+	ADD_SUBDIRECTORY("${libgit2_SOURCE_DIR}/deps/http-parser" "${libgit2_BINARY_DIR}/deps/http-parser")
+	LIST(APPEND LIBGIT2_INCLUDES "${libgit2_SOURCE_DIR}/deps/http-parser")
+	LIST(APPEND LIBGIT2_OBJECTS "$<TARGET_OBJECTS:http-parser>")
+	ADD_FEATURE_INFO(http-parser ON "http-parser support (bundled)")
+ENDIF()
+
+# Optional external dependency: zlib
+IF(NOT USE_BUNDLED_ZLIB)
+	FIND_PACKAGE(ZLIB)
+	IF(ZLIB_FOUND)
+		LIST(APPEND LIBGIT2_INCLUDES ${ZLIB_INCLUDE_DIRS})
+		LIST(APPEND LIBGIT2_LIBS ${ZLIB_LIBRARIES})
+		IF(APPLE OR CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
+			LIST(APPEND LIBGIT2_LIBS "z")
+			LIST(APPEND LIBGIT2_PC_LIBS "-lz")
+		ELSE()
+			LIST(APPEND LIBGIT2_PC_REQUIRES "zlib")
+		ENDIF()
+		ADD_FEATURE_INFO(zlib ON "using system zlib")
+	ELSE()
+		MESSAGE(STATUS "zlib was not found; using bundled 3rd-party sources." )
+	ENDIF()
+ENDIF()
+IF(USE_BUNDLED_ZLIB OR NOT ZLIB_FOUND)
+	ADD_SUBDIRECTORY("${libgit2_SOURCE_DIR}/deps/zlib" "${libgit2_BINARY_DIR}/deps/zlib")
+	LIST(APPEND LIBGIT2_INCLUDES "${libgit2_SOURCE_DIR}/deps/zlib")
+	LIST(APPEND LIBGIT2_OBJECTS $<TARGET_OBJECTS:zlib>)
+	ADD_FEATURE_INFO(zlib ON "using bundled zlib")
+ENDIF()
+
+# Optional external dependency: libssh2
+IF (USE_SSH)
+	FIND_PKGLIBRARIES(LIBSSH2 libssh2)
+ENDIF()
+IF (LIBSSH2_FOUND)
+	SET(GIT_SSH 1)
+	LIST(APPEND LIBGIT2_INCLUDES ${LIBSSH2_INCLUDE_DIRS})
+	LIST(APPEND LIBGIT2_LIBS ${LIBSSH2_LIBRARIES})
+	LIST(APPEND LIBGIT2_PC_LIBS ${LIBSSH2_LDFLAGS})
+
+	CHECK_LIBRARY_EXISTS("${LIBSSH2_LIBRARIES}" libssh2_userauth_publickey_frommemory "${LIBSSH2_LIBRARY_DIRS}" HAVE_LIBSSH2_MEMORY_CREDENTIALS)
+	IF (HAVE_LIBSSH2_MEMORY_CREDENTIALS)
+		SET(GIT_SSH_MEMORY_CREDENTIALS 1)
+	ENDIF()
+ELSE()
+	MESSAGE(STATUS "LIBSSH2 not found. Set CMAKE_PREFIX_PATH if it is installed outside of the default search path.")
+ENDIF()
+ADD_FEATURE_INFO(SSH GIT_SSH "SSH transport support")
+
+# Optional external dependency: libgssapi
+IF (USE_GSSAPI)
+	FIND_PACKAGE(GSSAPI)
+ENDIF()
+IF (GSSAPI_FOUND)
+	SET(GIT_GSSAPI 1)
+	LIST(APPEND LIBGIT2_LIBS ${GSSAPI_LIBRARIES})
+ENDIF()
+ADD_FEATURE_INFO(SPNEGO GIT_GSSAPI "SPNEGO authentication support")
+
+# Optional external dependency: iconv
+IF (USE_ICONV)
+	FIND_PACKAGE(Iconv)
+ENDIF()
+IF (ICONV_FOUND)
+	SET(GIT_USE_ICONV 1)
+	LIST(APPEND LIBGIT2_INCLUDES ${ICONV_INCLUDE_DIR})
+	LIST(APPEND LIBGIT2_LIBS ${ICONV_LIBRARIES})
+	LIST(APPEND LIBGIT2_PC_LIBS ${ICONV_LIBRARIES})
+ENDIF()
+ADD_FEATURE_INFO(iconv GIT_USE_ICONV "iconv encoding conversion support")
+
+
+IF (THREADSAFE)
+	IF (NOT WIN32)
+		FIND_PACKAGE(Threads REQUIRED)
+	ENDIF()
+
+	SET(GIT_THREADS 1)
+ENDIF()
+
+IF (USE_NSEC)
+	SET(GIT_USE_NSEC 1)
+ENDIF()
+
+IF (HAVE_STRUCT_STAT_ST_MTIM)
+	SET(GIT_USE_STAT_MTIM 1)
+ELSEIF (HAVE_STRUCT_STAT_ST_MTIMESPEC)
+	SET(GIT_USE_STAT_MTIMESPEC 1)
+ELSEIF (HAVE_STRUCT_STAT_ST_MTIME_NSEC)
+	SET(GIT_USE_STAT_MTIME_NSEC 1)
+ENDIF()
+
+ADD_DEFINITIONS(-D_FILE_OFFSET_BITS=64)
+
+# Collect sourcefiles
+FILE(GLOB SRC_H
+	"${libgit2_SOURCE_DIR}/include/git2.h"
+	"${libgit2_SOURCE_DIR}/include/git2/*.h"
+	"${libgit2_SOURCE_DIR}/include/git2/sys/*.h")
+
+# On Windows use specific platform sources
+IF (WIN32 AND NOT CYGWIN)
+	ADD_DEFINITIONS(-DWIN32 -D_WIN32_WINNT=0x0501)
+
+	IF(MSVC)
+		SET(WIN_RC "win32/git2.rc")
+	ENDIF()
+
+	FILE(GLOB SRC_OS win32/*.c win32/*.h)
+ELSEIF (AMIGA)
+	ADD_DEFINITIONS(-DNO_ADDRINFO -DNO_READDIR_R -DNO_MMAP)
+ELSE()
+	IF (VALGRIND)
+		ADD_DEFINITIONS(-DNO_MMAP)
+	ENDIF()
+	FILE(GLOB SRC_OS unix/*.c unix/*.h)
+ENDIF()
+FILE(GLOB SRC_GIT2 *.c *.h
+	streams/*.c streams/*.h
+	transports/*.c transports/*.h
+	xdiff/*.c xdiff/*.h)
+
+# Determine architecture of the machine
+IF (CMAKE_SIZEOF_VOID_P EQUAL 8)
+	SET(GIT_ARCH_64 1)
+ELSEIF (CMAKE_SIZEOF_VOID_P EQUAL 4)
+	SET(GIT_ARCH_32 1)
+ELSEIF (CMAKE_SIZEOF_VOID_P)
+	MESSAGE(FATAL_ERROR "Unsupported architecture (pointer size is ${CMAKE_SIZEOF_VOID_P} bytes)")
+ELSE()
+	MESSAGE(FATAL_ERROR "Unsupported architecture (CMAKE_SIZEOF_VOID_P is unset)")
+ENDIF()
+
+CONFIGURE_FILE(features.h.in git2/sys/features.h)
+
+SET(LIBGIT2_SOURCES ${SRC_H} ${SRC_GIT2} ${SRC_OS} ${SRC_SSH} ${SRC_SHA1})
+
+ADD_LIBRARY(git2internal OBJECT ${LIBGIT2_SOURCES})
+IDE_SPLIT_SOURCES(git2internal)
+LIST(APPEND LIBGIT2_OBJECTS $<TARGET_OBJECTS:git2internal>)
+
+IF (${CMAKE_VERSION} VERSION_LESS 2.8.12)
+	INCLUDE_DIRECTORIES(${LIBGIT2_INCLUDES})
+ELSE()
+	TARGET_INCLUDE_DIRECTORIES(git2internal
+	    PRIVATE ${LIBGIT2_INCLUDES}
+	    PUBLIC ${libgit2_SOURCE_DIR}/include)
+ENDIF()
+
+SET(LIBGIT2_OBJECTS ${LIBGIT2_OBJECTS} PARENT_SCOPE)
+SET(LIBGIT2_INCLUDES ${LIBGIT2_INCLUDES} PARENT_SCOPE)
+SET(LIBGIT2_LIBS ${LIBGIT2_LIBS} PARENT_SCOPE)
+
+IF(XCODE_VERSION)
+	# This is required for Xcode to actually link the libgit2 library
+	# when using only object libraries.
+	FILE(WRITE ${CMAKE_CURRENT_BINARY_DIR}/dummy.c "")
+	LIST(APPEND LIBGIT2_OBJECTS ${CMAKE_CURRENT_BINARY_DIR}/dummy.c)
+ENDIF()
+
+# Compile and link libgit2
+ADD_LIBRARY(git2 ${WIN_RC} ${LIBGIT2_OBJECTS})
+TARGET_LINK_LIBRARIES(git2 ${LIBGIT2_LIBS})
+
+SET_TARGET_PROPERTIES(git2 PROPERTIES LIBRARY_OUTPUT_DIRECTORY ${libgit2_BINARY_DIR})
+SET_TARGET_PROPERTIES(git2 PROPERTIES RUNTIME_OUTPUT_DIRECTORY ${libgit2_BINARY_DIR})
+SET_TARGET_PROPERTIES(git2 PROPERTIES ARCHIVE_OUTPUT_DIRECTORY ${libgit2_BINARY_DIR})
+
+# Workaround for Cmake bug #0011240 (see http://public.kitware.com/Bug/view.php?id=11240)
+# Win64+MSVC+static libs = linker error
+IF(MSVC AND GIT_ARCH_64 AND NOT BUILD_SHARED_LIBS)
+  SET_TARGET_PROPERTIES(git2 PROPERTIES STATIC_LIBRARY_FLAGS "/MACHINE:x64")
+ENDIF()
+
+IDE_SPLIT_SOURCES(git2)
+
+IF (SONAME)
+	SET_TARGET_PROPERTIES(git2 PROPERTIES VERSION ${LIBGIT2_VERSION_STRING})
+	SET_TARGET_PROPERTIES(git2 PROPERTIES SOVERSION ${LIBGIT2_SOVERSION})
+	IF (LIBGIT2_FILENAME)
+		ADD_DEFINITIONS(-DLIBGIT2_FILENAME=\"${LIBGIT2_FILENAME}\")
+		SET_TARGET_PROPERTIES(git2 PROPERTIES OUTPUT_NAME ${LIBGIT2_FILENAME})
+	ELSEIF (DEFINED LIBGIT2_PREFIX)
+		SET_TARGET_PROPERTIES(git2 PROPERTIES PREFIX "${LIBGIT2_PREFIX}")
+	ENDIF()
+ENDIF()
+
+LIST(REMOVE_DUPLICATES LIBGIT2_PC_REQUIRES)
+STRING(REPLACE ";" " " LIBGIT2_PC_REQUIRES "${LIBGIT2_PC_REQUIRES}")
+STRING(REPLACE ";" " " LIBGIT2_PC_LIBS "${LIBGIT2_PC_LIBS}")
+CONFIGURE_FILE(${libgit2_SOURCE_DIR}/libgit2.pc.in ${libgit2_BINARY_DIR}/libgit2.pc @ONLY)
+
+IF (MSVC_IDE)
+   # Precompiled headers
+   SET_TARGET_PROPERTIES(git2 PROPERTIES COMPILE_FLAGS "/Yuprecompiled.h /FIprecompiled.h")
+   SET_SOURCE_FILES_PROPERTIES(win32/precompiled.c COMPILE_FLAGS "/Ycprecompiled.h")
+ENDIF ()
+
+# Install
+INSTALL(TARGETS git2
+	RUNTIME DESTINATION ${BIN_INSTALL_DIR}
+	LIBRARY DESTINATION ${LIB_INSTALL_DIR}
+	ARCHIVE DESTINATION ${LIB_INSTALL_DIR}
+)
+INSTALL(FILES ${libgit2_BINARY_DIR}/libgit2.pc DESTINATION ${LIB_INSTALL_DIR}/pkgconfig )
+INSTALL(DIRECTORY ${libgit2_SOURCE_DIR}/include/git2 DESTINATION ${INCLUDE_INSTALL_DIR} )
+INSTALL(FILES ${libgit2_SOURCE_DIR}/include/git2.h DESTINATION ${INCLUDE_INSTALL_DIR} )

vendor/libgit2-sys/libgit2/src/annotated_commit.c

diff --git a/vendor/libgit2-sys/libgit2/src/annotated_commit.c b/vendor/libgit2-sys/libgit2/src/annotated_commit.c
new file mode 100644
index 0000000..72ba80a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/annotated_commit.c
@@ -0,0 +1,221 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "annotated_commit.h"
+
+#include "refs.h"
+#include "cache.h"
+
+#include "git2/commit.h"
+#include "git2/refs.h"
+#include "git2/repository.h"
+#include "git2/annotated_commit.h"
+#include "git2/revparse.h"
+#include "git2/tree.h"
+#include "git2/index.h"
+
+static int annotated_commit_init(
+	git_annotated_commit **out,
+	git_commit *commit,
+	const char *description)
+{
+	git_annotated_commit *annotated_commit;
+	int error = 0;
+
+	assert(out && commit);
+
+	*out = NULL;
+
+	annotated_commit = git__calloc(1, sizeof(git_annotated_commit));
+	GITERR_CHECK_ALLOC(annotated_commit);
+
+	annotated_commit->type = GIT_ANNOTATED_COMMIT_REAL;
+
+	if ((error = git_commit_dup(&annotated_commit->commit, commit)) < 0)
+		goto done;
+
+	git_oid_fmt(annotated_commit->id_str, git_commit_id(commit));
+	annotated_commit->id_str[GIT_OID_HEXSZ] = '\0';
+
+	if (!description)
+		description = annotated_commit->id_str;
+
+	annotated_commit->description = git__strdup(description);
+	GITERR_CHECK_ALLOC(annotated_commit->description);
+
+done:
+	if (!error)
+		*out = annotated_commit;
+
+	return error;
+}
+
+static int annotated_commit_init_from_id(
+	git_annotated_commit **out,
+	git_repository *repo,
+	const git_oid *id,
+	const char *description)
+{
+	git_commit *commit = NULL;
+	int error = 0;
+
+	assert(out && repo && id);
+
+	*out = NULL;
+
+	if ((error = git_commit_lookup(&commit, repo, id)) < 0)
+		goto done;
+
+	error = annotated_commit_init(out, commit, description);
+
+done:
+	git_commit_free(commit);
+	return error;
+}
+
+int git_annotated_commit_lookup(
+	git_annotated_commit **out,
+	git_repository *repo,
+	const git_oid *id)
+{
+	return annotated_commit_init_from_id(out, repo, id, NULL);
+}
+
+int git_annotated_commit_from_commit(
+	git_annotated_commit **out,
+	git_commit *commit)
+{
+	return annotated_commit_init(out, commit, NULL);
+}
+
+int git_annotated_commit_from_revspec(
+	git_annotated_commit **out,
+	git_repository *repo,
+	const char *revspec)
+{
+	git_object *obj, *commit;
+	int error;
+
+	assert(out && repo && revspec);
+
+	if ((error = git_revparse_single(&obj, repo, revspec)) < 0)
+		return error;
+
+	if ((error = git_object_peel(&commit, obj, GIT_OBJ_COMMIT))) {
+		git_object_free(obj);
+		return error;
+	}
+
+	error = annotated_commit_init(out, (git_commit *)commit, revspec);
+
+	git_object_free(obj);
+	git_object_free(commit);
+
+	return error;
+}
+
+int git_annotated_commit_from_ref(
+	git_annotated_commit **out,
+	git_repository *repo,
+	const git_reference *ref)
+{
+	git_reference *resolved;
+	int error = 0;
+
+	assert(out && repo && ref);
+
+	*out = NULL;
+
+	if ((error = git_reference_resolve(&resolved, ref)) < 0)
+		return error;
+	
+	error = annotated_commit_init_from_id(out,
+		repo,
+		git_reference_target(resolved),
+		git_reference_name(ref));
+
+	if (!error) {
+		(*out)->ref_name = git__strdup(git_reference_name(ref));
+		GITERR_CHECK_ALLOC((*out)->ref_name);
+	}
+
+	git_reference_free(resolved);
+	return error;
+}
+
+int git_annotated_commit_from_head(
+	git_annotated_commit **out,
+	git_repository *repo)
+{
+	git_reference *head;
+	int error;
+
+	assert(out && repo);
+
+	*out = NULL;
+
+    if ((error = git_reference_lookup(&head, repo, GIT_HEAD_FILE)) < 0)
+		return -1;
+
+	error = git_annotated_commit_from_ref(out, repo, head);
+
+	git_reference_free(head);
+	return error;
+}
+
+int git_annotated_commit_from_fetchhead(
+	git_annotated_commit **out,
+	git_repository *repo,
+	const char *branch_name,
+	const char *remote_url,
+	const git_oid *id)
+{
+	assert(repo && id && branch_name && remote_url);
+
+	if (annotated_commit_init_from_id(out, repo, id, branch_name) < 0)
+		return -1;
+
+	(*out)->ref_name = git__strdup(branch_name);
+	GITERR_CHECK_ALLOC((*out)->ref_name);
+
+	(*out)->remote_url = git__strdup(remote_url);
+	GITERR_CHECK_ALLOC((*out)->remote_url);
+
+	return 0;
+}
+
+
+const git_oid *git_annotated_commit_id(
+	const git_annotated_commit *annotated_commit)
+{
+	assert(annotated_commit);
+	return git_commit_id(annotated_commit->commit);
+}
+
+void git_annotated_commit_free(git_annotated_commit *annotated_commit)
+{
+	if (annotated_commit == NULL)
+		return;
+
+	switch (annotated_commit->type) {
+		case GIT_ANNOTATED_COMMIT_REAL:
+			git_commit_free(annotated_commit->commit);
+			git_tree_free(annotated_commit->tree);
+			git__free((char *)annotated_commit->description);
+			git__free((char *)annotated_commit->ref_name);
+			git__free((char *)annotated_commit->remote_url);
+			break;
+		case GIT_ANNOTATED_COMMIT_VIRTUAL:
+			git_index_free(annotated_commit->index);
+			git_array_clear(annotated_commit->parents);
+			break;
+		default:
+			abort();
+	}
+
+	git__free(annotated_commit);
+}

vendor/libgit2-sys/libgit2/src/annotated_commit.h

diff --git a/vendor/libgit2-sys/libgit2/src/annotated_commit.h b/vendor/libgit2-sys/libgit2/src/annotated_commit.h
new file mode 100644
index 0000000..b390066
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/annotated_commit.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_annotated_commit_h__
+#define INCLUDE_annotated_commit_h__
+
+#include "common.h"
+
+#include "oidarray.h"
+
+#include "git2/oid.h"
+
+typedef enum {
+	GIT_ANNOTATED_COMMIT_REAL = 1,
+	GIT_ANNOTATED_COMMIT_VIRTUAL = 2,
+} git_annotated_commit_t;
+
+/**
+ * Internal structure for merge inputs.  An annotated commit is generally
+ * "real" and backed by an actual commit in the repository, but merge will
+ * internally create "virtual" commits that are in-memory intermediate
+ * commits backed by an index.
+ */
+struct git_annotated_commit {
+	git_annotated_commit_t type;
+
+	/* real commit */
+	git_commit *commit;
+	git_tree *tree;
+
+	/* virtual commit structure */
+	git_index *index;
+	git_array_oid_t parents;
+
+	/* how this commit was looked up */
+	const char *description;
+
+	const char *ref_name;
+	const char *remote_url;
+
+	char id_str[GIT_OID_HEXSZ+1];
+};
+
+extern int git_annotated_commit_from_head(git_annotated_commit **out,
+	git_repository *repo);
+extern int git_annotated_commit_from_commit(git_annotated_commit **out,
+	git_commit *commit);
+
+#endif

vendor/libgit2-sys/libgit2/src/apply.c

diff --git a/vendor/libgit2-sys/libgit2/src/apply.c b/vendor/libgit2-sys/libgit2/src/apply.c
new file mode 100644
index 0000000..7801a0a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/apply.c
@@ -0,0 +1,378 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "apply.h"
+
+#include <assert.h>
+
+#include "git2/patch.h"
+#include "git2/filter.h"
+#include "array.h"
+#include "patch.h"
+#include "fileops.h"
+#include "delta.h"
+#include "zstream.h"
+
+#define apply_err(...) \
+	( giterr_set(GITERR_PATCH, __VA_ARGS__), -1 )
+
+typedef struct {
+	/* The lines that we allocate ourself are allocated out of the pool.
+	 * (Lines may have been allocated out of the diff.)
+	 */
+	git_pool pool;
+	git_vector lines;
+} patch_image;
+
+static void patch_line_init(
+	git_diff_line *out,
+	const char *in,
+	size_t in_len,
+	size_t in_offset)
+{
+	out->content = in;
+	out->content_len = in_len;
+	out->content_offset = in_offset;
+}
+
+#define PATCH_IMAGE_INIT { GIT_POOL_INIT, GIT_VECTOR_INIT }
+
+static int patch_image_init_fromstr(
+	patch_image *out, const char *in, size_t in_len)
+{
+	git_diff_line *line;
+	const char *start, *end;
+
+	memset(out, 0x0, sizeof(patch_image));
+
+	git_pool_init(&out->pool, sizeof(git_diff_line));
+
+	for (start = in; start < in + in_len; start = end) {
+		end = memchr(start, '\n', in_len);
+
+		if (end == NULL)
+			end = in + in_len;
+
+		else if (end < in + in_len)
+			end++;
+
+		line = git_pool_mallocz(&out->pool, 1);
+		GITERR_CHECK_ALLOC(line);
+
+		if (git_vector_insert(&out->lines, line) < 0)
+			return -1;
+
+		patch_line_init(line, start, (end - start), (start - in));
+	}
+
+	return 0;
+}
+
+static void patch_image_free(patch_image *image)
+{
+	if (image == NULL)
+		return;
+
+	git_pool_clear(&image->pool);
+	git_vector_free(&image->lines);
+}
+
+static bool match_hunk(
+	patch_image *image,
+	patch_image *preimage,
+	size_t linenum)
+{
+	bool match = 0;
+	size_t i;
+
+	/* Ensure this hunk is within the image boundaries. */
+	if (git_vector_length(&preimage->lines) + linenum >
+		git_vector_length(&image->lines))
+		return 0;
+
+	match = 1;
+
+	/* Check exact match. */
+	for (i = 0; i < git_vector_length(&preimage->lines); i++) {
+		git_diff_line *preimage_line = git_vector_get(&preimage->lines, i);
+		git_diff_line *image_line = git_vector_get(&image->lines, linenum + i);
+
+		if (preimage_line->content_len != image_line->content_len ||
+			memcmp(preimage_line->content, image_line->content, image_line->content_len) != 0) {
+			match = 0;
+			break;
+		}
+	}
+
+	return match;
+}
+
+static bool find_hunk_linenum(
+	size_t *out,
+	patch_image *image,
+	patch_image *preimage,
+	size_t linenum)
+{
+	size_t max = git_vector_length(&image->lines);
+	bool match;
+
+	if (linenum > max)
+		linenum = max;
+
+	match = match_hunk(image, preimage, linenum);
+
+	*out = linenum;
+	return match;
+}
+
+static int update_hunk(
+	patch_image *image,
+	unsigned int linenum,
+	patch_image *preimage,
+	patch_image *postimage)
+{
+	size_t postlen = git_vector_length(&postimage->lines);
+	size_t prelen = git_vector_length(&preimage->lines);
+	size_t i;
+	int error = 0;
+
+	if (postlen > prelen)
+		error = git_vector_insert_null(
+			&image->lines, linenum, (postlen - prelen));
+	else if (prelen > postlen)
+		error = git_vector_remove_range(
+			&image->lines, linenum, (prelen - postlen));
+
+	if (error) {
+		giterr_set_oom();
+		return -1;
+	}
+
+	for (i = 0; i < git_vector_length(&postimage->lines); i++) {
+		image->lines.contents[linenum + i] =
+			git_vector_get(&postimage->lines, i);
+	}
+
+	return 0;
+}
+
+static int apply_hunk(
+	patch_image *image,
+	git_patch *patch,
+	git_patch_hunk *hunk)
+{
+	patch_image preimage = PATCH_IMAGE_INIT, postimage = PATCH_IMAGE_INIT;
+	size_t line_num, i;
+	int error = 0;
+
+	for (i = 0; i < hunk->line_count; i++) {
+		size_t linenum = hunk->line_start + i;
+		git_diff_line *line = git_array_get(patch->lines, linenum);
+
+		if (!line) {
+			error = apply_err("preimage does not contain line %"PRIuZ, linenum);
+			goto done;
+		}
+
+		if (line->origin == GIT_DIFF_LINE_CONTEXT ||
+			line->origin == GIT_DIFF_LINE_DELETION) {
+			if ((error = git_vector_insert(&preimage.lines, line)) < 0)
+				goto done;
+		}
+
+		if (line->origin == GIT_DIFF_LINE_CONTEXT ||
+			line->origin == GIT_DIFF_LINE_ADDITION) {
+			if ((error = git_vector_insert(&postimage.lines, line)) < 0)
+				goto done;
+		}
+	}
+
+	line_num = hunk->hunk.new_start ? hunk->hunk.new_start - 1 : 0;
+
+	if (!find_hunk_linenum(&line_num, image, &preimage, line_num)) {
+		error = apply_err("hunk at line %d did not apply",
+			hunk->hunk.new_start);
+		goto done;
+	}
+
+	error = update_hunk(image, line_num, &preimage, &postimage);
+
+done:
+	patch_image_free(&preimage);
+	patch_image_free(&postimage);
+
+	return error;
+}
+
+static int apply_hunks(
+	git_buf *out,
+	const char *source,
+	size_t source_len,
+	git_patch *patch)
+{
+	git_patch_hunk *hunk;
+	git_diff_line *line;
+	patch_image image;
+	size_t i;
+	int error = 0;
+
+	if ((error = patch_image_init_fromstr(&image, source, source_len)) < 0)
+		goto done;
+
+	git_array_foreach(patch->hunks, i, hunk) {
+		if ((error = apply_hunk(&image, patch, hunk)) < 0)
+			goto done;
+	}
+
+	git_vector_foreach(&image.lines, i, line)
+		git_buf_put(out, line->content, line->content_len);
+
+done:
+	patch_image_free(&image);
+
+	return error;
+}
+
+static int apply_binary_delta(
+	git_buf *out,
+	const char *source,
+	size_t source_len,
+	git_diff_binary_file *binary_file)
+{
+	git_buf inflated = GIT_BUF_INIT;
+	int error = 0;
+
+	/* no diff means identical contents */
+	if (binary_file->datalen == 0)
+		return git_buf_put(out, source, source_len);
+
+	error = git_zstream_inflatebuf(&inflated,
+		binary_file->data, binary_file->datalen);
+
+	if (!error && inflated.size != binary_file->inflatedlen) {
+		error = apply_err("inflated delta does not match expected length");
+		git_buf_free(out);
+	}
+
+	if (error < 0)
+		goto done;
+
+	if (binary_file->type == GIT_DIFF_BINARY_DELTA) {
+		void *data;
+		size_t data_len;
+
+		error = git_delta_apply(&data, &data_len, (void *)source, source_len,
+			(void *)inflated.ptr, inflated.size);
+
+		out->ptr = data;
+		out->size = data_len;
+		out->asize = data_len;
+	}
+	else if (binary_file->type == GIT_DIFF_BINARY_LITERAL) {
+		git_buf_swap(out, &inflated);
+	}
+	else {
+		error = apply_err("unknown binary delta type");
+		goto done;
+	}
+
+done:
+	git_buf_free(&inflated);
+	return error;
+}
+
+static int apply_binary(
+	git_buf *out,
+	const char *source,
+	size_t source_len,
+	git_patch *patch)
+{
+	git_buf reverse = GIT_BUF_INIT;
+	int error = 0;
+
+	if (!patch->binary.contains_data) {
+		error = apply_err("patch does not contain binary data");
+		goto done;
+	}
+
+	if (!patch->binary.old_file.datalen && !patch->binary.new_file.datalen)
+		goto done;
+
+	/* first, apply the new_file delta to the given source */
+	if ((error = apply_binary_delta(out, source, source_len,
+			&patch->binary.new_file)) < 0)
+		goto done;
+
+	/* second, apply the old_file delta to sanity check the result */
+	if ((error = apply_binary_delta(&reverse, out->ptr, out->size,
+			&patch->binary.old_file)) < 0)
+		goto done;
+
+	if (source_len != reverse.size ||
+		memcmp(source, reverse.ptr, source_len) != 0) {
+		error = apply_err("binary patch did not apply cleanly");
+		goto done;
+	}
+
+done:
+	if (error < 0)
+		git_buf_free(out);
+
+	git_buf_free(&reverse);
+	return error;
+}
+
+int git_apply__patch(
+	git_buf *contents_out,
+	char **filename_out,
+	unsigned int *mode_out,
+	const char *source,
+	size_t source_len,
+	git_patch *patch)
+{
+	char *filename = NULL;
+	unsigned int mode = 0;
+	int error = 0;
+
+	assert(contents_out && filename_out && mode_out && (source || !source_len) && patch);
+
+	*filename_out = NULL;
+	*mode_out = 0;
+
+	if (patch->delta->status != GIT_DELTA_DELETED) {
+		const git_diff_file *newfile = &patch->delta->new_file;
+
+		filename = git__strdup(newfile->path);
+		mode = newfile->mode ?
+			newfile->mode : GIT_FILEMODE_BLOB;
+	}
+
+	if (patch->delta->flags & GIT_DIFF_FLAG_BINARY)
+		error = apply_binary(contents_out, source, source_len, patch);
+	else if (patch->hunks.size)
+		error = apply_hunks(contents_out, source, source_len, patch);
+	else
+		error = git_buf_put(contents_out, source, source_len);
+
+	if (error)
+		goto done;
+
+	if (patch->delta->status == GIT_DELTA_DELETED &&
+		git_buf_len(contents_out) > 0) {
+		error = apply_err("removal patch leaves file contents");
+		goto done;
+	}
+
+	*filename_out = filename;
+	*mode_out = mode;
+
+done:
+	if (error < 0)
+		git__free(filename);
+
+	return error;
+}

vendor/libgit2-sys/libgit2/src/apply.h

diff --git a/vendor/libgit2-sys/libgit2/src/apply.h b/vendor/libgit2-sys/libgit2/src/apply.h
new file mode 100644
index 0000000..b29460c
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/apply.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_apply_h__
+#define INCLUDE_apply_h__
+
+#include "common.h"
+
+#include "git2/patch.h"
+#include "buffer.h"
+
+extern int git_apply__patch(
+	git_buf *out,
+	char **filename,
+	unsigned int *mode,
+	const char *source,
+	size_t source_len,
+	git_patch *patch);
+
+#endif

vendor/libgit2-sys/libgit2/src/array.h

diff --git a/vendor/libgit2-sys/libgit2/src/array.h b/vendor/libgit2-sys/libgit2/src/array.h
new file mode 100644
index 0000000..1d8a01c
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/array.h
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_array_h__
+#define INCLUDE_array_h__
+
+#include "common.h"
+
+/*
+ * Use this to declare a typesafe resizable array of items, a la:
+ *
+ *     git_array_t(int) my_ints = GIT_ARRAY_INIT;
+ *     ...
+ *     int *i = git_array_alloc(my_ints);
+ *     GITERR_CHECK_ALLOC(i);
+ *     ...
+ *     git_array_clear(my_ints);
+ *
+ * You may also want to do things like:
+ *
+ *     typedef git_array_t(my_struct) my_struct_array_t;
+ */
+#define git_array_t(type) struct { type *ptr; size_t size, asize; }
+
+#define GIT_ARRAY_INIT { NULL, 0, 0 }
+
+#define git_array_init(a) \
+	do { (a).size = (a).asize = 0; (a).ptr = NULL; } while (0)
+
+#define git_array_init_to_size(a, desired) \
+	do { (a).size = 0; (a).asize = desired; (a).ptr = git__calloc(desired, sizeof(*(a).ptr)); } while (0)
+
+#define git_array_clear(a) \
+	do { git__free((a).ptr); git_array_init(a); } while (0)
+
+#define GITERR_CHECK_ARRAY(a) GITERR_CHECK_ALLOC((a).ptr)
+
+
+typedef git_array_t(char) git_array_generic_t;
+
+/* use a generic array for growth so this can return the new item */
+GIT_INLINE(void *) git_array_grow(void *_a, size_t item_size)
+{
+	volatile git_array_generic_t *a = _a;
+	size_t new_size;
+	char *new_array;
+
+	if (a->size < 8) {
+		new_size = 8;
+	} else {
+		if (GIT_MULTIPLY_SIZET_OVERFLOW(&new_size, a->size, 3))
+			goto on_oom;
+		new_size /= 2;
+	}
+
+	if ((new_array = git__reallocarray(a->ptr, new_size, item_size)) == NULL)
+		goto on_oom;
+
+	a->ptr = new_array; a->asize = new_size; a->size++;
+	return a->ptr + (a->size - 1) * item_size;
+
+on_oom:
+	git_array_clear(*a);
+	return NULL;
+}
+
+#define git_array_alloc(a) \
+	(((a).size >= (a).asize) ? \
+	git_array_grow(&(a), sizeof(*(a).ptr)) : \
+	((a).ptr ? &(a).ptr[(a).size++] : NULL))
+
+#define git_array_last(a) ((a).size ? &(a).ptr[(a).size - 1] : NULL)
+
+#define git_array_pop(a) ((a).size ? &(a).ptr[--(a).size] : NULL)
+
+#define git_array_get(a, i) (((i) < (a).size) ? &(a).ptr[(i)] : NULL)
+
+#define git_array_size(a) (a).size
+
+#define git_array_valid_index(a, i) ((i) < (a).size)
+
+#define git_array_foreach(a, i, element) \
+	for ((i) = 0; (i) < (a).size && ((element) = &(a).ptr[(i)]); (i)++)
+
+GIT_INLINE(int) git_array__search(
+	size_t *out,
+	void *array_ptr,
+	size_t item_size,
+	size_t array_len,
+	int (*compare)(const void *, const void *),
+	const void *key)
+{
+	size_t lim;
+	unsigned char *part, *array = array_ptr, *base = array_ptr;
+	int cmp = -1;
+
+	for (lim = array_len; lim != 0; lim >>= 1) {
+		part = base + (lim >> 1) * item_size;
+		cmp = (*compare)(key, part);
+
+		if (cmp == 0) {
+			base = part;
+			break;
+		}
+		if (cmp > 0) { /* key > p; take right partition */
+			base = part + 1 * item_size;
+			lim--;
+		} /* else take left partition */
+	}
+
+	if (out)
+		*out = (base - array) / item_size;
+
+	return (cmp == 0) ? 0 : GIT_ENOTFOUND;
+}
+
+#define git_array_search(out, a, cmp, key) \
+	git_array__search(out, (a).ptr, sizeof(*(a).ptr), (a).size, \
+		(cmp), (key))
+
+#endif

vendor/libgit2-sys/libgit2/src/attr.c

diff --git a/vendor/libgit2-sys/libgit2/src/attr.c b/vendor/libgit2-sys/libgit2/src/attr.c
new file mode 100644
index 0000000..93d9551
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/attr.c
@@ -0,0 +1,572 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "attr.h"
+
+#include "repository.h"
+#include "sysdir.h"
+#include "config.h"
+#include "attr_file.h"
+#include "ignore.h"
+#include "git2/oid.h"
+#include <ctype.h>
+
+const char *git_attr__true  = "[internal]__TRUE__";
+const char *git_attr__false = "[internal]__FALSE__";
+const char *git_attr__unset = "[internal]__UNSET__";
+
+git_attr_t git_attr_value(const char *attr)
+{
+	if (attr == NULL || attr == git_attr__unset)
+		return GIT_ATTR_UNSPECIFIED_T;
+
+	if (attr == git_attr__true)
+		return GIT_ATTR_TRUE_T;
+
+	if (attr == git_attr__false)
+		return GIT_ATTR_FALSE_T;
+
+	return GIT_ATTR_VALUE_T;
+}
+
+static int collect_attr_files(
+	git_repository *repo,
+	git_attr_session *attr_session,
+	uint32_t flags,
+	const char *path,
+	git_vector *files);
+
+static void release_attr_files(git_vector *files);
+
+int git_attr_get(
+	const char **value,
+	git_repository *repo,
+	uint32_t flags,
+	const char *pathname,
+	const char *name)
+{
+	int error;
+	git_attr_path path;
+	git_vector files = GIT_VECTOR_INIT;
+	size_t i, j;
+	git_attr_file *file;
+	git_attr_name attr;
+	git_attr_rule *rule;
+	git_dir_flag dir_flag = GIT_DIR_FLAG_UNKNOWN;
+
+	assert(value && repo && name);
+
+	*value = NULL;
+
+	if (git_repository_is_bare(repo))
+		dir_flag = GIT_DIR_FLAG_FALSE;
+
+	if (git_attr_path__init(&path, pathname, git_repository_workdir(repo), dir_flag) < 0)
+		return -1;
+
+	if ((error = collect_attr_files(repo, NULL, flags, pathname, &files)) < 0)
+		goto cleanup;
+
+	memset(&attr, 0, sizeof(attr));
+	attr.name = name;
+	attr.name_hash = git_attr_file__name_hash(name);
+
+	git_vector_foreach(&files, i, file) {
+
+		git_attr_file__foreach_matching_rule(file, &path, j, rule) {
+			size_t pos;
+
+			if (!git_vector_bsearch(&pos, &rule->assigns, &attr)) {
+				*value = ((git_attr_assignment *)git_vector_get(
+							  &rule->assigns, pos))->value;
+				goto cleanup;
+			}
+		}
+	}
+
+cleanup:
+	release_attr_files(&files);
+	git_attr_path__free(&path);
+
+	return error;
+}
+
+
+typedef struct {
+	git_attr_name name;
+	git_attr_assignment *found;
+} attr_get_many_info;
+
+int git_attr_get_many_with_session(
+	const char **values,
+	git_repository *repo,
+	git_attr_session *attr_session,
+	uint32_t flags,
+	const char *pathname,
+	size_t num_attr,
+	const char **names)
+{
+	int error;
+	git_attr_path path;
+	git_vector files = GIT_VECTOR_INIT;
+	size_t i, j, k;
+	git_attr_file *file;
+	git_attr_rule *rule;
+	attr_get_many_info *info = NULL;
+	size_t num_found = 0;
+	git_dir_flag dir_flag = GIT_DIR_FLAG_UNKNOWN;
+
+	if (!num_attr)
+		return 0;
+
+	assert(values && repo && names);
+
+	if (git_repository_is_bare(repo))
+		dir_flag = GIT_DIR_FLAG_FALSE;
+
+	if (git_attr_path__init(&path, pathname, git_repository_workdir(repo), dir_flag) < 0)
+		return -1;
+
+	if ((error = collect_attr_files(repo, attr_session, flags, pathname, &files)) < 0)
+		goto cleanup;
+
+	info = git__calloc(num_attr, sizeof(attr_get_many_info));
+	GITERR_CHECK_ALLOC(info);
+
+	git_vector_foreach(&files, i, file) {
+
+		git_attr_file__foreach_matching_rule(file, &path, j, rule) {
+
+			for (k = 0; k < num_attr; k++) {
+				size_t pos;
+
+				if (info[k].found != NULL) /* already found assignment */
+					continue;
+
+				if (!info[k].name.name) {
+					info[k].name.name = names[k];
+					info[k].name.name_hash = git_attr_file__name_hash(names[k]);
+				}
+
+				if (!git_vector_bsearch(&pos, &rule->assigns, &info[k].name)) {
+					info[k].found = (git_attr_assignment *)
+						git_vector_get(&rule->assigns, pos);
+					values[k] = info[k].found->value;
+
+					if (++num_found == num_attr)
+						goto cleanup;
+				}
+			}
+		}
+	}
+
+	for (k = 0; k < num_attr; k++) {
+		if (!info[k].found)
+			values[k] = NULL;
+	}
+
+cleanup:
+	release_attr_files(&files);
+	git_attr_path__free(&path);
+	git__free(info);
+
+	return error;
+}
+
+int git_attr_get_many(
+	const char **values,
+	git_repository *repo,
+	uint32_t flags,
+	const char *pathname,
+	size_t num_attr,
+	const char **names)
+{
+	return git_attr_get_many_with_session(
+		values, repo, NULL, flags, pathname, num_attr, names);
+}
+
+int git_attr_foreach(
+	git_repository *repo,
+	uint32_t flags,
+	const char *pathname,
+	int (*callback)(const char *name, const char *value, void *payload),
+	void *payload)
+{
+	int error;
+	git_attr_path path;
+	git_vector files = GIT_VECTOR_INIT;
+	size_t i, j, k;
+	git_attr_file *file;
+	git_attr_rule *rule;
+	git_attr_assignment *assign;
+	git_strmap *seen = NULL;
+	git_dir_flag dir_flag = GIT_DIR_FLAG_UNKNOWN;
+
+	assert(repo && callback);
+
+	if (git_repository_is_bare(repo))
+		dir_flag = GIT_DIR_FLAG_FALSE;
+
+	if (git_attr_path__init(&path, pathname, git_repository_workdir(repo), dir_flag) < 0)
+		return -1;
+
+	if ((error = collect_attr_files(repo, NULL, flags, pathname, &files)) < 0 ||
+		(error = git_strmap_alloc(&seen)) < 0)
+		goto cleanup;
+
+	git_vector_foreach(&files, i, file) {
+
+		git_attr_file__foreach_matching_rule(file, &path, j, rule) {
+
+			git_vector_foreach(&rule->assigns, k, assign) {
+				/* skip if higher priority assignment was already seen */
+				if (git_strmap_exists(seen, assign->name))
+					continue;
+
+				git_strmap_insert(seen, assign->name, assign, &error);
+				if (error < 0)
+					goto cleanup;
+
+				error = callback(assign->name, assign->value, payload);
+				if (error) {
+					giterr_set_after_callback(error);
+					goto cleanup;
+				}
+			}
+		}
+	}
+
+cleanup:
+	git_strmap_free(seen);
+	release_attr_files(&files);
+	git_attr_path__free(&path);
+
+	return error;
+}
+
+static int preload_attr_file(
+	git_repository *repo,
+	git_attr_session *attr_session,
+	git_attr_file_source source,
+	const char *base,
+	const char *file)
+{
+	int error;
+	git_attr_file *preload = NULL;
+
+	if (!file)
+		return 0;
+	if (!(error = git_attr_cache__get(
+			&preload, repo, attr_session, source, base, file, git_attr_file__parse_buffer)))
+		git_attr_file__free(preload);
+
+	return error;
+}
+
+static int system_attr_file(
+	git_buf *out,
+	git_attr_session *attr_session)
+{
+	int error;
+
+	if (!attr_session) {
+		error = git_sysdir_find_system_file(out, GIT_ATTR_FILE_SYSTEM);
+
+		if (error == GIT_ENOTFOUND)
+			giterr_clear();
+
+		return error;
+	}
+
+	if (!attr_session->init_sysdir) {
+		error = git_sysdir_find_system_file(&attr_session->sysdir, GIT_ATTR_FILE_SYSTEM);
+
+		if (error == GIT_ENOTFOUND)
+			giterr_clear();
+		else if (error)
+			return error;
+
+		attr_session->init_sysdir = 1;
+	}
+
+	if (attr_session->sysdir.size == 0)
+		return GIT_ENOTFOUND;
+
+	/* We can safely provide a git_buf with no allocation (asize == 0) to
+	 * a consumer. This allows them to treat this as a regular `git_buf`,
+	 * but their call to `git_buf_free` will not attempt to free it.
+	 */
+	git_buf_attach_notowned(
+		out, attr_session->sysdir.ptr, attr_session->sysdir.size);
+	return 0;
+}
+
+static int attr_setup(git_repository *repo, git_attr_session *attr_session)
+{
+	int error = 0;
+	const char *workdir = git_repository_workdir(repo);
+	git_index *idx = NULL;
+	git_buf path = GIT_BUF_INIT;
+
+	if (attr_session && attr_session->init_setup)
+		return 0;
+
+	if ((error = git_attr_cache__init(repo)) < 0)
+		return error;
+
+	/* preload attribute files that could contain macros so the
+	 * definitions will be available for later file parsing
+	 */
+
+	error = system_attr_file(&path, attr_session);
+
+	if (error == 0)
+		error = preload_attr_file(
+			repo, attr_session, GIT_ATTR_FILE__FROM_FILE, NULL, path.ptr);
+
+	if (error != GIT_ENOTFOUND)
+		goto out;
+
+	if ((error = preload_attr_file(
+			repo, attr_session, GIT_ATTR_FILE__FROM_FILE,
+			NULL, git_repository_attr_cache(repo)->cfg_attr_file)) < 0)
+		goto out;
+
+	if ((error = git_repository_item_path(&path,
+			repo, GIT_REPOSITORY_ITEM_INFO)) < 0)
+		goto out;
+
+	if ((error = preload_attr_file(
+			repo, attr_session, GIT_ATTR_FILE__FROM_FILE,
+			path.ptr, GIT_ATTR_FILE_INREPO)) < 0)
+		goto out;
+
+	if (workdir != NULL &&
+		(error = preload_attr_file(
+			repo, attr_session, GIT_ATTR_FILE__FROM_FILE, workdir, GIT_ATTR_FILE)) < 0)
+		goto out;
+
+	if ((error = git_repository_index__weakptr(&idx, repo)) < 0 ||
+		(error = preload_attr_file(
+			repo, attr_session, GIT_ATTR_FILE__FROM_INDEX, NULL, GIT_ATTR_FILE)) < 0)
+		goto out;
+
+	if (attr_session)
+		attr_session->init_setup = 1;
+
+out:
+	git_buf_free(&path);
+
+	return error;
+}
+
+int git_attr_add_macro(
+	git_repository *repo,
+	const char *name,
+	const char *values)
+{
+	int error;
+	git_attr_rule *macro = NULL;
+	git_pool *pool;
+
+	if ((error = git_attr_cache__init(repo)) < 0)
+		return error;
+
+	macro = git__calloc(1, sizeof(git_attr_rule));
+	GITERR_CHECK_ALLOC(macro);
+
+	pool = &git_repository_attr_cache(repo)->pool;
+
+	macro->match.pattern = git_pool_strdup(pool, name);
+	GITERR_CHECK_ALLOC(macro->match.pattern);
+
+	macro->match.length = strlen(macro->match.pattern);
+	macro->match.flags = GIT_ATTR_FNMATCH_MACRO;
+
+	error = git_attr_assignment__parse(repo, pool, &macro->assigns, &values);
+
+	if (!error)
+		error = git_attr_cache__insert_macro(repo, macro);
+
+	if (error < 0)
+		git_attr_rule__free(macro);
+
+	return error;
+}
+
+typedef struct {
+	git_repository *repo;
+	git_attr_session *attr_session;
+	uint32_t flags;
+	const char *workdir;
+	git_index *index;
+	git_vector *files;
+} attr_walk_up_info;
+
+static int attr_decide_sources(
+	uint32_t flags, bool has_wd, bool has_index, git_attr_file_source *srcs)
+{
+	int count = 0;
+
+	switch (flags & 0x03) {
+	case GIT_ATTR_CHECK_FILE_THEN_INDEX:
+		if (has_wd)
+			srcs[count++] = GIT_ATTR_FILE__FROM_FILE;
+		if (has_index)
+			srcs[count++] = GIT_ATTR_FILE__FROM_INDEX;
+		break;
+	case GIT_ATTR_CHECK_INDEX_THEN_FILE:
+		if (has_index)
+			srcs[count++] = GIT_ATTR_FILE__FROM_INDEX;
+		if (has_wd)
+			srcs[count++] = GIT_ATTR_FILE__FROM_FILE;
+		break;
+	case GIT_ATTR_CHECK_INDEX_ONLY:
+		if (has_index)
+			srcs[count++] = GIT_ATTR_FILE__FROM_INDEX;
+		break;
+	}
+
+	return count;
+}
+
+static int push_attr_file(
+	git_repository *repo,
+	git_attr_session *attr_session,
+	git_vector *list,
+	git_attr_file_source source,
+	const char *base,
+	const char *filename)
+{
+	int error = 0;
+	git_attr_file *file = NULL;
+
+	error = git_attr_cache__get(&file, repo, attr_session,
+		source, base, filename, git_attr_file__parse_buffer);
+
+	if (error < 0)
+		return error;
+
+	if (file != NULL) {
+		if ((error = git_vector_insert(list, file)) < 0)
+			git_attr_file__free(file);
+	}
+
+	return error;
+}
+
+static int push_one_attr(void *ref, const char *path)
+{
+	int error = 0, n_src, i;
+	attr_walk_up_info *info = (attr_walk_up_info *)ref;
+	git_attr_file_source src[2];
+
+	n_src = attr_decide_sources(
+		info->flags, info->workdir != NULL, info->index != NULL, src);
+
+	for (i = 0; !error && i < n_src; ++i)
+		error = push_attr_file(info->repo, info->attr_session,
+			info->files, src[i], path, GIT_ATTR_FILE);
+
+	return error;
+}
+
+static void release_attr_files(git_vector *files)
+{
+	size_t i;
+	git_attr_file *file;
+
+	git_vector_foreach(files, i, file) {
+		git_attr_file__free(file);
+		files->contents[i] = NULL;
+	}
+	git_vector_free(files);
+}
+
+static int collect_attr_files(
+	git_repository *repo,
+	git_attr_session *attr_session,
+	uint32_t flags,
+	const char *path,
+	git_vector *files)
+{
+	int error = 0;
+	git_buf dir = GIT_BUF_INIT, attrfile = GIT_BUF_INIT;
+	const char *workdir = git_repository_workdir(repo);
+	attr_walk_up_info info = { NULL };
+
+	if ((error = attr_setup(repo, attr_session)) < 0)
+		return error;
+
+	/* Resolve path in a non-bare repo */
+	if (workdir != NULL)
+		error = git_path_find_dir(&dir, path, workdir);
+	else
+		error = git_path_dirname_r(&dir, path);
+	if (error < 0)
+		goto cleanup;
+
+	/* in precendence order highest to lowest:
+	 * - $GIT_DIR/info/attributes
+	 * - path components with .gitattributes
+	 * - config core.attributesfile
+	 * - $GIT_PREFIX/etc/gitattributes
+	 */
+
+	error = git_repository_item_path(&attrfile, repo, GIT_REPOSITORY_ITEM_INFO);
+	if (error < 0)
+		goto cleanup;
+
+	error = push_attr_file(
+		repo, attr_session, files, GIT_ATTR_FILE__FROM_FILE,
+		attrfile.ptr, GIT_ATTR_FILE_INREPO);
+	if (error < 0)
+		goto cleanup;
+
+	info.repo = repo;
+	info.attr_session = attr_session;
+	info.flags = flags;
+	info.workdir = workdir;
+	if (git_repository_index__weakptr(&info.index, repo) < 0)
+		giterr_clear(); /* no error even if there is no index */
+	info.files = files;
+
+	if (!strcmp(dir.ptr, "."))
+		error = push_one_attr(&info, "");
+	else
+		error = git_path_walk_up(&dir, workdir, push_one_attr, &info);
+
+	if (error < 0)
+		goto cleanup;
+
+	if (git_repository_attr_cache(repo)->cfg_attr_file != NULL) {
+		error = push_attr_file(
+			repo, attr_session, files, GIT_ATTR_FILE__FROM_FILE,
+			NULL, git_repository_attr_cache(repo)->cfg_attr_file);
+		if (error < 0)
+			goto cleanup;
+	}
+
+	if ((flags & GIT_ATTR_CHECK_NO_SYSTEM) == 0) {
+		error = system_attr_file(&dir, attr_session);
+
+		if (!error)
+			error = push_attr_file(
+				repo, attr_session, files, GIT_ATTR_FILE__FROM_FILE,
+				NULL, dir.ptr);
+		else if (error == GIT_ENOTFOUND)
+			error = 0;
+	}
+
+ cleanup:
+	if (error < 0)
+		release_attr_files(files);
+	git_buf_free(&attrfile);
+	git_buf_free(&dir);
+
+	return error;
+}

vendor/libgit2-sys/libgit2/src/attr.h

diff --git a/vendor/libgit2-sys/libgit2/src/attr.h b/vendor/libgit2-sys/libgit2/src/attr.h
new file mode 100644
index 0000000..9775652
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/attr.h
@@ -0,0 +1,15 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_attr_h__
+#define INCLUDE_attr_h__
+
+#include "common.h"
+
+#include "attr_file.h"
+#include "attrcache.h"
+
+#endif

vendor/libgit2-sys/libgit2/src/attr_file.c

diff --git a/vendor/libgit2-sys/libgit2/src/attr_file.c b/vendor/libgit2-sys/libgit2/src/attr_file.c
new file mode 100644
index 0000000..f46cce3
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/attr_file.c
@@ -0,0 +1,882 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "attr_file.h"
+
+#include "repository.h"
+#include "filebuf.h"
+#include "attrcache.h"
+#include "git2/blob.h"
+#include "git2/tree.h"
+#include "index.h"
+#include <ctype.h>
+
+static void attr_file_free(git_attr_file *file)
+{
+	bool unlock = !git_mutex_lock(&file->lock);
+	git_attr_file__clear_rules(file, false);
+	git_pool_clear(&file->pool);
+	if (unlock)
+		git_mutex_unlock(&file->lock);
+	git_mutex_free(&file->lock);
+
+	git__memzero(file, sizeof(*file));
+	git__free(file);
+}
+
+int git_attr_file__new(
+	git_attr_file **out,
+	git_attr_file_entry *entry,
+	git_attr_file_source source)
+{
+	git_attr_file *attrs = git__calloc(1, sizeof(git_attr_file));
+	GITERR_CHECK_ALLOC(attrs);
+
+	if (git_mutex_init(&attrs->lock) < 0) {
+		giterr_set(GITERR_OS, "failed to initialize lock");
+		git__free(attrs);
+		return -1;
+	}
+
+	git_pool_init(&attrs->pool, 1);
+	GIT_REFCOUNT_INC(attrs);
+	attrs->entry  = entry;
+	attrs->source = source;
+	*out = attrs;
+	return 0;
+}
+
+int git_attr_file__clear_rules(git_attr_file *file, bool need_lock)
+{
+	unsigned int i;
+	git_attr_rule *rule;
+
+	if (need_lock && git_mutex_lock(&file->lock) < 0) {
+		giterr_set(GITERR_OS, "failed to lock attribute file");
+		return -1;
+	}
+
+	git_vector_foreach(&file->rules, i, rule)
+		git_attr_rule__free(rule);
+	git_vector_free(&file->rules);
+
+	if (need_lock)
+		git_mutex_unlock(&file->lock);
+
+	return 0;
+}
+
+void git_attr_file__free(git_attr_file *file)
+{
+	if (!file)
+		return;
+	GIT_REFCOUNT_DEC(file, attr_file_free);
+}
+
+static int attr_file_oid_from_index(
+	git_oid *oid, git_repository *repo, const char *path)
+{
+	int error;
+	git_index *idx;
+	size_t pos;
+	const git_index_entry *entry;
+
+	if ((error = git_repository_index__weakptr(&idx, repo)) < 0 ||
+		(error = git_index__find_pos(&pos, idx, path, 0, 0)) < 0)
+		return error;
+
+	if (!(entry = git_index_get_byindex(idx, pos)))
+		return GIT_ENOTFOUND;
+
+	*oid = entry->id;
+	return 0;
+}
+
+int git_attr_file__load(
+	git_attr_file **out,
+	git_repository *repo,
+	git_attr_session *attr_session,
+	git_attr_file_entry *entry,
+	git_attr_file_source source,
+	git_attr_file_parser parser)
+{
+	int error = 0;
+	git_blob *blob = NULL;
+	git_buf content = GIT_BUF_INIT;
+	git_attr_file *file;
+	struct stat st;
+	bool nonexistent = false;
+
+	*out = NULL;
+
+	switch (source) {
+	case GIT_ATTR_FILE__IN_MEMORY:
+		/* in-memory attribute file doesn't need data */
+		break;
+	case GIT_ATTR_FILE__FROM_INDEX: {
+		git_oid id;
+
+		if ((error = attr_file_oid_from_index(&id, repo, entry->path)) < 0 ||
+			(error = git_blob_lookup(&blob, repo, &id)) < 0)
+			return error;
+
+		/* Do not assume that data straight from the ODB is NULL-terminated;
+		 * copy the contents of a file to a buffer to work on */
+		git_buf_put(&content, git_blob_rawcontent(blob), git_blob_rawsize(blob));
+		break;
+	}
+	case GIT_ATTR_FILE__FROM_FILE: {
+		int fd = -1;
+
+		/* For open or read errors, pretend that we got ENOTFOUND. */
+		/* TODO: issue warning when warning API is available */
+
+		if (p_stat(entry->fullpath, &st) < 0 ||
+			S_ISDIR(st.st_mode) ||
+			(fd = git_futils_open_ro(entry->fullpath)) < 0 ||
+			(error = git_futils_readbuffer_fd(&content, fd, (size_t)st.st_size)) < 0)
+			nonexistent = true;
+
+		if (fd >= 0)
+			p_close(fd);
+
+		break;
+	}
+	default:
+		giterr_set(GITERR_INVALID, "unknown file source %d", source);
+		return -1;
+	}
+
+	if ((error = git_attr_file__new(&file, entry, source)) < 0)
+		goto cleanup;
+
+	/* store the key of the attr_reader; don't bother with cache
+	 * invalidation during the same attr reader session.
+	 */
+	if (attr_session)
+		file->session_key = attr_session->key;
+
+	if (parser && (error = parser(repo, file, git_buf_cstr(&content))) < 0) {
+		git_attr_file__free(file);
+		goto cleanup;
+	}
+
+	/* write cache breakers */
+	if (nonexistent)
+		file->nonexistent = 1;
+	else if (source == GIT_ATTR_FILE__FROM_INDEX)
+		git_oid_cpy(&file->cache_data.oid, git_blob_id(blob));
+	else if (source == GIT_ATTR_FILE__FROM_FILE)
+		git_futils_filestamp_set_from_stat(&file->cache_data.stamp, &st);
+	/* else always cacheable */
+
+	*out = file;
+
+cleanup:
+	git_blob_free(blob);
+	git_buf_free(&content);
+
+	return error;
+}
+
+int git_attr_file__out_of_date(
+	git_repository *repo,
+	git_attr_session *attr_session,
+	git_attr_file *file)
+{
+	if (!file)
+		return 1;
+
+	/* we are never out of date if we just created this data in the same
+	 * attr_session; otherwise, nonexistent files must be invalidated
+	 */
+	if (attr_session && attr_session->key == file->session_key)
+		return 0;
+	else if (file->nonexistent)
+		return 1;
+
+	switch (file->source) {
+	case GIT_ATTR_FILE__IN_MEMORY:
+		return 0;
+
+	case GIT_ATTR_FILE__FROM_FILE:
+		return git_futils_filestamp_check(
+			&file->cache_data.stamp, file->entry->fullpath);
+
+	case GIT_ATTR_FILE__FROM_INDEX: {
+		int error;
+		git_oid id;
+
+		if ((error = attr_file_oid_from_index(
+				&id, repo, file->entry->path)) < 0)
+			return error;
+
+		return (git_oid__cmp(&file->cache_data.oid, &id) != 0);
+	}
+
+	default:
+		giterr_set(GITERR_INVALID, "invalid file type %d", file->source);
+		return -1;
+	}
+}
+
+static int sort_by_hash_and_name(const void *a_raw, const void *b_raw);
+static void git_attr_rule__clear(git_attr_rule *rule);
+static bool parse_optimized_patterns(
+	git_attr_fnmatch *spec,
+	git_pool *pool,
+	const char *pattern);
+
+int git_attr_file__parse_buffer(
+	git_repository *repo, git_attr_file *attrs, const char *data)
+{
+	int error = 0;
+	const char *scan = data, *context = NULL;
+	git_attr_rule *rule = NULL;
+
+	/* if subdir file path, convert context for file paths */
+	if (attrs->entry &&
+		git_path_root(attrs->entry->path) < 0 &&
+		!git__suffixcmp(attrs->entry->path, "/" GIT_ATTR_FILE))
+		context = attrs->entry->path;
+
+	if (git_mutex_lock(&attrs->lock) < 0) {
+		giterr_set(GITERR_OS, "failed to lock attribute file");
+		return -1;
+	}
+
+	while (!error && *scan) {
+		/* allocate rule if needed */
+		if (!rule && !(rule = git__calloc(1, sizeof(*rule)))) {
+			error = -1;
+			break;
+		}
+
+		rule->match.flags =
+			GIT_ATTR_FNMATCH_ALLOWNEG | GIT_ATTR_FNMATCH_ALLOWMACRO;
+
+		/* parse the next "pattern attr attr attr" line */
+		if (!(error = git_attr_fnmatch__parse(
+				&rule->match, &attrs->pool, context, &scan)) &&
+			!(error = git_attr_assignment__parse(
+				repo, &attrs->pool, &rule->assigns, &scan)))
+		{
+			if (rule->match.flags & GIT_ATTR_FNMATCH_MACRO)
+				/* TODO: warning if macro found in file below repo root */
+				error = git_attr_cache__insert_macro(repo, rule);
+			else
+				error = git_vector_insert(&attrs->rules, rule);
+		}
+
+		/* if the rule wasn't a pattern, on to the next */
+		if (error < 0) {
+			git_attr_rule__clear(rule); /* reset rule contents */
+			if (error == GIT_ENOTFOUND)
+				error = 0;
+		} else {
+			rule = NULL; /* vector now "owns" the rule */
+		}
+	}
+
+	git_mutex_unlock(&attrs->lock);
+	git_attr_rule__free(rule);
+
+	return error;
+}
+
+uint32_t git_attr_file__name_hash(const char *name)
+{
+	uint32_t h = 5381;
+	int c;
+	assert(name);
+	while ((c = (int)*name++) != 0)
+		h = ((h << 5) + h) + c;
+	return h;
+}
+
+int git_attr_file__lookup_one(
+	git_attr_file *file,
+	git_attr_path *path,
+	const char *attr,
+	const char **value)
+{
+	size_t i;
+	git_attr_name name;
+	git_attr_rule *rule;
+
+	*value = NULL;
+
+	name.name = attr;
+	name.name_hash = git_attr_file__name_hash(attr);
+
+	git_attr_file__foreach_matching_rule(file, path, i, rule) {
+		size_t pos;
+
+		if (!git_vector_bsearch(&pos, &rule->assigns, &name)) {
+			*value = ((git_attr_assignment *)
+					  git_vector_get(&rule->assigns, pos))->value;
+			break;
+		}
+	}
+
+	return 0;
+}
+
+int git_attr_file__load_standalone(git_attr_file **out, const char *path)
+{
+	int error;
+	git_attr_file *file;
+	git_buf content = GIT_BUF_INIT;
+
+	error = git_attr_file__new(&file, NULL, GIT_ATTR_FILE__FROM_FILE);
+	if (error < 0)
+		return error;
+
+	error = git_attr_cache__alloc_file_entry(
+		&file->entry, NULL, path, &file->pool);
+	if (error < 0) {
+		git_attr_file__free(file);
+		return error;
+	}
+	/* because the cache entry is allocated from the file's own pool, we
+	 * don't have to free it - freeing file+pool will free cache entry, too.
+	 */
+
+	if (!(error = git_futils_readbuffer(&content, path))) {
+		error = git_attr_file__parse_buffer(NULL, file, content.ptr);
+		git_buf_free(&content);
+	}
+
+	if (error < 0)
+		git_attr_file__free(file);
+	else
+		*out = file;
+
+	return error;
+}
+
+bool git_attr_fnmatch__match(
+	git_attr_fnmatch *match,
+	git_attr_path *path)
+{
+	const char *relpath = path->path;
+	const char *filename;
+	int flags = 0;
+
+	/*
+	 * If the rule was generated in a subdirectory, we must only
+	 * use it for paths inside that directory. We can thus return
+	 * a non-match if the prefixes don't match.
+	 */
+	if (match->containing_dir) {
+		if (match->flags & GIT_ATTR_FNMATCH_ICASE) {
+			if (git__strncasecmp(path->path, match->containing_dir, match->containing_dir_length))
+				return 0;
+		} else {
+			if (git__prefixcmp(path->path, match->containing_dir))
+				return 0;
+		}
+
+		relpath += match->containing_dir_length;
+	}
+
+	if (match->flags & GIT_ATTR_FNMATCH_ICASE)
+		flags |= FNM_CASEFOLD;
+	if (match->flags & GIT_ATTR_FNMATCH_LEADINGDIR)
+		flags |= FNM_LEADING_DIR;
+
+	if (match->flags & GIT_ATTR_FNMATCH_FULLPATH) {
+		filename = relpath;
+		flags |= FNM_PATHNAME;
+	} else {
+		filename = path->basename;
+
+		if (path->is_dir)
+			flags |= FNM_LEADING_DIR;
+	}
+
+	if ((match->flags & GIT_ATTR_FNMATCH_DIRECTORY) && !path->is_dir) {
+		bool samename;
+
+		/*
+		 * for attribute checks or checks at the root of this match's
+		 * containing_dir (or root of the repository if no containing_dir),
+		 * do not match.
+		 */
+		if (!(match->flags & GIT_ATTR_FNMATCH_IGNORE) ||
+			path->basename == relpath)
+			return false;
+
+		flags |= FNM_LEADING_DIR;
+
+		/* fail match if this is a file with same name as ignored folder */
+		samename = (match->flags & GIT_ATTR_FNMATCH_ICASE) ?
+			!strcasecmp(match->pattern, relpath) :
+			!strcmp(match->pattern, relpath);
+
+		if (samename)
+			return false;
+
+		return (p_fnmatch(match->pattern, relpath, flags) != FNM_NOMATCH);
+	}
+
+	/* if path is a directory prefix of a negated pattern, then match */
+	if ((match->flags & GIT_ATTR_FNMATCH_NEGATIVE) && path->is_dir) {
+		size_t pathlen = strlen(relpath);
+		bool prefixed = (pathlen <= match->length) &&
+			((match->flags & GIT_ATTR_FNMATCH_ICASE) ?
+			!strncasecmp(match->pattern, relpath, pathlen) :
+			!strncmp(match->pattern, relpath, pathlen));
+
+		if (prefixed && git_path_at_end_of_segment(&match->pattern[pathlen]))
+			return true;
+	}
+
+	return (p_fnmatch(match->pattern, filename, flags) != FNM_NOMATCH);
+}
+
+bool git_attr_rule__match(
+	git_attr_rule *rule,
+	git_attr_path *path)
+{
+	bool matched = git_attr_fnmatch__match(&rule->match, path);
+
+	if (rule->match.flags & GIT_ATTR_FNMATCH_NEGATIVE)
+		matched = !matched;
+
+	return matched;
+}
+
+git_attr_assignment *git_attr_rule__lookup_assignment(
+	git_attr_rule *rule, const char *name)
+{
+	size_t pos;
+	git_attr_name key;
+	key.name = name;
+	key.name_hash = git_attr_file__name_hash(name);
+
+	if (git_vector_bsearch(&pos, &rule->assigns, &key))
+		return NULL;
+
+	return git_vector_get(&rule->assigns, pos);
+}
+
+int git_attr_path__init(
+	git_attr_path *info, const char *path, const char *base, git_dir_flag dir_flag)
+{
+	ssize_t root;
+
+	/* build full path as best we can */
+	git_buf_init(&info->full, 0);
+
+	if (git_path_join_unrooted(&info->full, path, base, &root) < 0)
+		return -1;
+
+	info->path = info->full.ptr + root;
+
+	/* remove trailing slashes */
+	while (info->full.size > 0) {
+		if (info->full.ptr[info->full.size - 1] != '/')
+			break;
+		info->full.size--;
+	}
+	info->full.ptr[info->full.size] = '\0';
+
+	/* skip leading slashes in path */
+	while (*info->path == '/')
+		info->path++;
+
+	/* find trailing basename component */
+	info->basename = strrchr(info->path, '/');
+	if (info->basename)
+		info->basename++;
+	if (!info->basename || !*info->basename)
+		info->basename = info->path;
+
+	switch (dir_flag)
+	{
+	case GIT_DIR_FLAG_FALSE:
+		info->is_dir = 0;
+		break;
+
+	case GIT_DIR_FLAG_TRUE:
+		info->is_dir = 1;
+		break;
+
+	case GIT_DIR_FLAG_UNKNOWN:
+	default:
+		info->is_dir = (int)git_path_isdir(info->full.ptr);
+		break;
+	}
+
+	return 0;
+}
+
+void git_attr_path__free(git_attr_path *info)
+{
+	git_buf_free(&info->full);
+	info->path = NULL;
+	info->basename = NULL;
+}
+
+/*
+ * From gitattributes(5):
+ *
+ * Patterns have the following format:
+ *
+ * - A blank line matches no files, so it can serve as a separator for
+ *   readability.
+ *
+ * - A line starting with # serves as a comment.
+ *
+ * - An optional prefix ! which negates the pattern; any matching file
+ *   excluded by a previous pattern will become included again. If a negated
+ *   pattern matches, this will override lower precedence patterns sources.
+ *
+ * - If the pattern ends with a slash, it is removed for the purpose of the
+ *   following description, but it would only find a match with a directory. In
+ *   other words, foo/ will match a directory foo and paths underneath it, but
+ *   will not match a regular file or a symbolic link foo (this is consistent
+ *   with the way how pathspec works in general in git).
+ *
+ * - If the pattern does not contain a slash /, git treats it as a shell glob
+ *   pattern and checks for a match against the pathname without leading
+ *   directories.
+ *
+ * - Otherwise, git treats the pattern as a shell glob suitable for consumption
+ *   by fnmatch(3) with the FNM_PATHNAME flag: wildcards in the pattern will
+ *   not match a / in the pathname. For example, "Documentation/\*.html" matches
+ *   "Documentation/git.html" but not "Documentation/ppc/ppc.html". A leading
+ *   slash matches the beginning of the pathname; for example, "/\*.c" matches
+ *   "cat-file.c" but not "mozilla-sha1/sha1.c".
+ */
+
+/*
+ * This will return 0 if the spec was filled out,
+ * GIT_ENOTFOUND if the fnmatch does not require matching, or
+ * another error code there was an actual problem.
+ */
+int git_attr_fnmatch__parse(
+	git_attr_fnmatch *spec,
+	git_pool *pool,
+	const char *context,
+	const char **base)
+{
+	const char *pattern, *scan;
+	int slash_count, allow_space;
+
+	assert(spec && base && *base);
+
+	if (parse_optimized_patterns(spec, pool, *base))
+		return 0;
+
+	spec->flags = (spec->flags & GIT_ATTR_FNMATCH__INCOMING);
+	allow_space = ((spec->flags & GIT_ATTR_FNMATCH_ALLOWSPACE) != 0);
+
+	pattern = *base;
+
+	while (git__isspace(*pattern)) pattern++;
+	if (!*pattern || *pattern == '#') {
+		*base = git__next_line(pattern);
+		return GIT_ENOTFOUND;
+	}
+
+	if (*pattern == '[' && (spec->flags & GIT_ATTR_FNMATCH_ALLOWMACRO) != 0) {
+		if (strncmp(pattern, "[attr]", 6) == 0) {
+			spec->flags = spec->flags | GIT_ATTR_FNMATCH_MACRO;
+			pattern += 6;
+		}
+		/* else a character range like [a-e]* which is accepted */
+	}
+
+	if (*pattern == '!' && (spec->flags & GIT_ATTR_FNMATCH_ALLOWNEG) != 0) {
+		spec->flags = spec->flags |
+			GIT_ATTR_FNMATCH_NEGATIVE | GIT_ATTR_FNMATCH_LEADINGDIR;
+		pattern++;
+	}
+
+	slash_count = 0;
+	for (scan = pattern; *scan != '\0'; ++scan) {
+		/* scan until (non-escaped) white space */
+		if (git__isspace(*scan) && *(scan - 1) != '\\') {
+			if (!allow_space || (*scan != ' ' && *scan != '\t' && *scan != '\r'))
+				break;
+		}
+
+		if (*scan == '/') {
+			spec->flags = spec->flags | GIT_ATTR_FNMATCH_FULLPATH;
+			slash_count++;
+			if (pattern == scan)
+				pattern++;
+		}
+		/* remember if we see an unescaped wildcard in pattern */
+		else if (git__iswildcard(*scan) &&
+			(scan == pattern || (*(scan - 1) != '\\')))
+			spec->flags = spec->flags | GIT_ATTR_FNMATCH_HASWILD;
+	}
+
+	*base = scan;
+
+	if ((spec->length = scan - pattern) == 0)
+		return GIT_ENOTFOUND;
+
+	/*
+	 * Remove one trailing \r in case this is a CRLF delimited
+	 * file, in the case of Icon\r\r\n, we still leave the first
+	 * \r there to match against.
+	 */
+	if (pattern[spec->length - 1] == '\r')
+		if (--spec->length == 0)
+			return GIT_ENOTFOUND;
+
+	/* Remove trailing spaces. */
+	while (pattern[spec->length - 1] == ' ' || pattern[spec->length - 1] == '\t')
+		if (--spec->length == 0)
+			return GIT_ENOTFOUND;
+
+	if (pattern[spec->length - 1] == '/') {
+		spec->length--;
+		spec->flags = spec->flags | GIT_ATTR_FNMATCH_DIRECTORY;
+		if (--slash_count <= 0)
+			spec->flags = spec->flags & ~GIT_ATTR_FNMATCH_FULLPATH;
+	}
+	if ((spec->flags & GIT_ATTR_FNMATCH_NOLEADINGDIR) == 0 &&
+		spec->length >= 2 &&
+		pattern[spec->length - 1] == '*' &&
+		pattern[spec->length - 2] == '/') {
+		spec->length -= 2;
+		spec->flags = spec->flags | GIT_ATTR_FNMATCH_LEADINGDIR;
+		/* leave FULLPATH match on, however */
+	}
+
+	if (context) {
+		char *slash = strrchr(context, '/');
+		size_t len;
+		if (slash) {
+			/* include the slash for easier matching */
+			len = slash - context + 1;
+			spec->containing_dir = git_pool_strndup(pool, context, len);
+			spec->containing_dir_length = len;
+		}
+	}
+
+	spec->pattern = git_pool_strndup(pool, pattern, spec->length);
+
+	if (!spec->pattern) {
+		*base = git__next_line(pattern);
+		return -1;
+	} else {
+		/* strip '\' that might have be used for internal whitespace */
+		spec->length = git__unescape(spec->pattern);
+		/* TODO: convert remaining '\' into '/' for POSIX ??? */
+	}
+
+	return 0;
+}
+
+static bool parse_optimized_patterns(
+	git_attr_fnmatch *spec,
+	git_pool *pool,
+	const char *pattern)
+{
+	if (!pattern[1] && (pattern[0] == '*' || pattern[0] == '.')) {
+		spec->flags = GIT_ATTR_FNMATCH_MATCH_ALL;
+		spec->pattern = git_pool_strndup(pool, pattern, 1);
+		spec->length = 1;
+
+		return true;
+	}
+
+	return false;
+}
+
+static int sort_by_hash_and_name(const void *a_raw, const void *b_raw)
+{
+	const git_attr_name *a = a_raw;
+	const git_attr_name *b = b_raw;
+
+	if (b->name_hash < a->name_hash)
+		return 1;
+	else if (b->name_hash > a->name_hash)
+		return -1;
+	else
+		return strcmp(b->name, a->name);
+}
+
+static void git_attr_assignment__free(git_attr_assignment *assign)
+{
+	/* name and value are stored in a git_pool associated with the
+	 * git_attr_file, so they do not need to be freed here
+	 */
+	assign->name = NULL;
+	assign->value = NULL;
+	git__free(assign);
+}
+
+static int merge_assignments(void **old_raw, void *new_raw)
+{
+	git_attr_assignment **old = (git_attr_assignment **)old_raw;
+	git_attr_assignment *new = (git_attr_assignment *)new_raw;
+
+	GIT_REFCOUNT_DEC(*old, git_attr_assignment__free);
+	*old = new;
+	return GIT_EEXISTS;
+}
+
+int git_attr_assignment__parse(
+	git_repository *repo,
+	git_pool *pool,
+	git_vector *assigns,
+	const char **base)
+{
+	int error;
+	const char *scan = *base;
+	git_attr_assignment *assign = NULL;
+
+	assert(assigns && !assigns->length);
+
+	git_vector_set_cmp(assigns, sort_by_hash_and_name);
+
+	while (*scan && *scan != '\n') {
+		const char *name_start, *value_start;
+
+		/* skip leading blanks */
+		while (git__isspace(*scan) && *scan != '\n') scan++;
+
+		/* allocate assign if needed */
+		if (!assign) {
+			assign = git__calloc(1, sizeof(git_attr_assignment));
+			GITERR_CHECK_ALLOC(assign);
+			GIT_REFCOUNT_INC(assign);
+		}
+
+		assign->name_hash = 5381;
+		assign->value = git_attr__true;
+
+		/* look for magic name prefixes */
+		if (*scan == '-') {
+			assign->value = git_attr__false;
+			scan++;
+		} else if (*scan == '!') {
+			assign->value = git_attr__unset; /* explicit unspecified state */
+			scan++;
+		} else if (*scan == '#') /* comment rest of line */
+			break;
+
+		/* find the name */
+		name_start = scan;
+		while (*scan && !git__isspace(*scan) && *scan != '=') {
+			assign->name_hash =
+				((assign->name_hash << 5) + assign->name_hash) + *scan;
+			scan++;
+		}
+		if (scan == name_start) {
+			/* must have found lone prefix (" - ") or leading = ("=foo")
+			 * or end of buffer -- advance until whitespace and continue
+			 */
+			while (*scan && !git__isspace(*scan)) scan++;
+			continue;
+		}
+
+		/* allocate permanent storage for name */
+		assign->name = git_pool_strndup(pool, name_start, scan - name_start);
+		GITERR_CHECK_ALLOC(assign->name);
+
+		/* if there is an equals sign, find the value */
+		if (*scan == '=') {
+			for (value_start = ++scan; *scan && !git__isspace(*scan); ++scan);
+
+			/* if we found a value, allocate permanent storage for it */
+			if (scan > value_start) {
+				assign->value = git_pool_strndup(pool, value_start, scan - value_start);
+				GITERR_CHECK_ALLOC(assign->value);
+			}
+		}
+
+		/* expand macros (if given a repo with a macro cache) */
+		if (repo != NULL && assign->value == git_attr__true) {
+			git_attr_rule *macro =
+				git_attr_cache__lookup_macro(repo, assign->name);
+
+			if (macro != NULL) {
+				unsigned int i;
+				git_attr_assignment *massign;
+
+				git_vector_foreach(&macro->assigns, i, massign) {
+					GIT_REFCOUNT_INC(massign);
+
+					error = git_vector_insert_sorted(
+						assigns, massign, &merge_assignments);
+					if (error < 0 && error != GIT_EEXISTS) {
+						git_attr_assignment__free(assign);
+						return error;
+					}
+				}
+			}
+		}
+
+		/* insert allocated assign into vector */
+		error = git_vector_insert_sorted(assigns, assign, &merge_assignments);
+		if (error < 0 && error != GIT_EEXISTS)
+			return error;
+
+		/* clear assign since it is now "owned" by the vector */
+		assign = NULL;
+	}
+
+	if (assign != NULL)
+		git_attr_assignment__free(assign);
+
+	*base = git__next_line(scan);
+
+	return (assigns->length == 0) ? GIT_ENOTFOUND : 0;
+}
+
+static void git_attr_rule__clear(git_attr_rule *rule)
+{
+	unsigned int i;
+	git_attr_assignment *assign;
+
+	if (!rule)
+		return;
+
+	if (!(rule->match.flags & GIT_ATTR_FNMATCH_IGNORE)) {
+		git_vector_foreach(&rule->assigns, i, assign)
+			GIT_REFCOUNT_DEC(assign, git_attr_assignment__free);
+		git_vector_free(&rule->assigns);
+	}
+
+	/* match.pattern is stored in a git_pool, so no need to free */
+	rule->match.pattern = NULL;
+	rule->match.length = 0;
+}
+
+void git_attr_rule__free(git_attr_rule *rule)
+{
+	git_attr_rule__clear(rule);
+	git__free(rule);
+}
+
+int git_attr_session__init(git_attr_session *session, git_repository *repo)
+{
+	assert(repo);
+
+	session->key = git_atomic_inc(&repo->attr_session_key);
+
+	return 0;
+}
+
+void git_attr_session__free(git_attr_session *session)
+{
+	if (!session)
+		return;
+
+	git_buf_free(&session->sysdir);
+	git_buf_free(&session->tmp);
+
+	memset(session, 0, sizeof(git_attr_session));
+}

vendor/libgit2-sys/libgit2/src/attr_file.h

diff --git a/vendor/libgit2-sys/libgit2/src/attr_file.h b/vendor/libgit2-sys/libgit2/src/attr_file.h
new file mode 100644
index 0000000..fedf55a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/attr_file.h
@@ -0,0 +1,220 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_attr_file_h__
+#define INCLUDE_attr_file_h__
+
+#include "common.h"
+
+#include "git2/oid.h"
+#include "git2/attr.h"
+#include "vector.h"
+#include "pool.h"
+#include "buffer.h"
+#include "fileops.h"
+
+#define GIT_ATTR_FILE			".gitattributes"
+#define GIT_ATTR_FILE_INREPO	"attributes"
+#define GIT_ATTR_FILE_SYSTEM	"gitattributes"
+#define GIT_ATTR_FILE_XDG		"attributes"
+
+#define GIT_ATTR_FNMATCH_NEGATIVE	(1U << 0)
+#define GIT_ATTR_FNMATCH_DIRECTORY	(1U << 1)
+#define GIT_ATTR_FNMATCH_FULLPATH	(1U << 2)
+#define GIT_ATTR_FNMATCH_MACRO		(1U << 3)
+#define GIT_ATTR_FNMATCH_IGNORE		(1U << 4)
+#define GIT_ATTR_FNMATCH_HASWILD	(1U << 5)
+#define GIT_ATTR_FNMATCH_ALLOWSPACE	(1U << 6)
+#define GIT_ATTR_FNMATCH_ICASE		(1U << 7)
+#define GIT_ATTR_FNMATCH_MATCH_ALL	(1U << 8)
+#define GIT_ATTR_FNMATCH_ALLOWNEG   (1U << 9)
+#define GIT_ATTR_FNMATCH_ALLOWMACRO (1U << 10)
+#define GIT_ATTR_FNMATCH_LEADINGDIR (1U << 11)
+#define GIT_ATTR_FNMATCH_NOLEADINGDIR (1U << 12)
+
+#define GIT_ATTR_FNMATCH__INCOMING \
+	(GIT_ATTR_FNMATCH_ALLOWSPACE | GIT_ATTR_FNMATCH_ALLOWNEG | \
+	 GIT_ATTR_FNMATCH_ALLOWMACRO | GIT_ATTR_FNMATCH_NOLEADINGDIR)
+
+typedef enum {
+	GIT_ATTR_FILE__IN_MEMORY   = 0,
+	GIT_ATTR_FILE__FROM_FILE   = 1,
+	GIT_ATTR_FILE__FROM_INDEX  = 2,
+
+	GIT_ATTR_FILE_NUM_SOURCES  = 3
+} git_attr_file_source;
+
+extern const char *git_attr__true;
+extern const char *git_attr__false;
+extern const char *git_attr__unset;
+
+typedef struct {
+	char *pattern;
+	size_t length;
+	char *containing_dir;
+	size_t containing_dir_length;
+	unsigned int flags;
+} git_attr_fnmatch;
+
+typedef struct {
+	git_attr_fnmatch match;
+	git_vector assigns;		/* vector of <git_attr_assignment*> */
+} git_attr_rule;
+
+typedef struct {
+	git_refcount unused;
+	const char *name;
+	uint32_t name_hash;
+} git_attr_name;
+
+typedef struct {
+	git_refcount rc;		/* for macros */
+	char *name;
+	uint32_t name_hash;
+	const char *value;
+} git_attr_assignment;
+
+typedef struct git_attr_file_entry git_attr_file_entry;
+
+typedef struct {
+	git_refcount rc;
+	git_mutex lock;
+	git_attr_file_entry *entry;
+	git_attr_file_source source;
+	git_vector rules;			/* vector of <rule*> or <fnmatch*> */
+	git_pool pool;
+	unsigned int nonexistent:1;
+	int session_key;
+	union {
+		git_oid oid;
+		git_futils_filestamp stamp;
+	} cache_data;
+} git_attr_file;
+
+struct git_attr_file_entry {
+	git_attr_file *file[GIT_ATTR_FILE_NUM_SOURCES];
+	const char *path; /* points into fullpath */
+	char fullpath[GIT_FLEX_ARRAY];
+};
+
+typedef struct {
+	git_buf  full;
+	char    *path;
+	char    *basename;
+	int      is_dir;
+} git_attr_path;
+
+/* A git_attr_session can provide an "instance" of reading, to prevent cache
+ * invalidation during a single operation instance (like checkout).
+ */
+
+typedef struct {
+	int key;
+	unsigned int init_setup:1,
+		init_sysdir:1;
+	git_buf sysdir;
+	git_buf tmp;
+} git_attr_session;
+
+extern int git_attr_session__init(git_attr_session *attr_session, git_repository *repo);
+extern void git_attr_session__free(git_attr_session *session);
+
+extern int git_attr_get_many_with_session(
+	const char **values_out,
+	git_repository *repo,
+	git_attr_session *attr_session,
+	uint32_t flags,
+	const char *path,
+	size_t num_attr,
+	const char **names);
+
+typedef int (*git_attr_file_parser)(
+	git_repository *repo,
+	git_attr_file *file,
+	const char *data);
+
+/*
+ * git_attr_file API
+ */
+
+int git_attr_file__new(
+	git_attr_file **out,
+	git_attr_file_entry *entry,
+	git_attr_file_source source);
+
+void git_attr_file__free(git_attr_file *file);
+
+int git_attr_file__load(
+	git_attr_file **out,
+	git_repository *repo,
+	git_attr_session *attr_session,
+	git_attr_file_entry *ce,
+	git_attr_file_source source,
+	git_attr_file_parser parser);
+
+int git_attr_file__load_standalone(
+	git_attr_file **out, const char *path);
+
+int git_attr_file__out_of_date(
+	git_repository *repo, git_attr_session *session, git_attr_file *file);
+
+int git_attr_file__parse_buffer(
+	git_repository *repo, git_attr_file *attrs, const char *data);
+
+int git_attr_file__clear_rules(
+	git_attr_file *file, bool need_lock);
+
+int git_attr_file__lookup_one(
+	git_attr_file *file,
+	git_attr_path *path,
+	const char *attr,
+	const char **value);
+
+/* loop over rules in file from bottom to top */
+#define git_attr_file__foreach_matching_rule(file, path, iter, rule)	\
+	git_vector_rforeach(&(file)->rules, (iter), (rule)) \
+		if (git_attr_rule__match((rule), (path)))
+
+uint32_t git_attr_file__name_hash(const char *name);
+
+
+/*
+ * other utilities
+ */
+
+extern int git_attr_fnmatch__parse(
+	git_attr_fnmatch *spec,
+	git_pool *pool,
+	const char *source,
+	const char **base);
+
+extern bool git_attr_fnmatch__match(
+	git_attr_fnmatch *rule,
+	git_attr_path *path);
+
+extern void git_attr_rule__free(git_attr_rule *rule);
+
+extern bool git_attr_rule__match(
+	git_attr_rule *rule,
+	git_attr_path *path);
+
+extern git_attr_assignment *git_attr_rule__lookup_assignment(
+	git_attr_rule *rule, const char *name);
+
+typedef enum { GIT_DIR_FLAG_TRUE = 1, GIT_DIR_FLAG_FALSE = 0, GIT_DIR_FLAG_UNKNOWN = -1 } git_dir_flag;
+
+extern int git_attr_path__init(
+	git_attr_path *info, const char *path, const char *base, git_dir_flag is_dir);
+
+extern void git_attr_path__free(git_attr_path *info);
+
+extern int git_attr_assignment__parse(
+	git_repository *repo, /* needed to expand macros */
+	git_pool *pool,
+	git_vector *assigns,
+	const char **scan);
+
+#endif

vendor/libgit2-sys/libgit2/src/attrcache.c

diff --git a/vendor/libgit2-sys/libgit2/src/attrcache.c b/vendor/libgit2-sys/libgit2/src/attrcache.c
new file mode 100644
index 0000000..65e7b46
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/attrcache.c
@@ -0,0 +1,469 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "attrcache.h"
+
+#include "repository.h"
+#include "attr_file.h"
+#include "config.h"
+#include "sysdir.h"
+#include "ignore.h"
+
+GIT_INLINE(int) attr_cache_lock(git_attr_cache *cache)
+{
+	GIT_UNUSED(cache); /* avoid warning if threading is off */
+
+	if (git_mutex_lock(&cache->lock) < 0) {
+		giterr_set(GITERR_OS, "unable to get attr cache lock");
+		return -1;
+	}
+	return 0;
+}
+
+GIT_INLINE(void) attr_cache_unlock(git_attr_cache *cache)
+{
+	GIT_UNUSED(cache); /* avoid warning if threading is off */
+	git_mutex_unlock(&cache->lock);
+}
+
+GIT_INLINE(git_attr_file_entry *) attr_cache_lookup_entry(
+	git_attr_cache *cache, const char *path)
+{
+	khiter_t pos = git_strmap_lookup_index(cache->files, path);
+
+	if (git_strmap_valid_index(cache->files, pos))
+		return git_strmap_value_at(cache->files, pos);
+	else
+		return NULL;
+}
+
+int git_attr_cache__alloc_file_entry(
+	git_attr_file_entry **out,
+	const char *base,
+	const char *path,
+	git_pool *pool)
+{
+	size_t baselen = 0, pathlen = strlen(path);
+	size_t cachesize = sizeof(git_attr_file_entry) + pathlen + 1;
+	git_attr_file_entry *ce;
+
+	if (base != NULL && git_path_root(path) < 0) {
+		baselen = strlen(base);
+		cachesize += baselen;
+
+		if (baselen && base[baselen - 1] != '/')
+			cachesize++;
+	}
+
+	ce = git_pool_mallocz(pool, (uint32_t)cachesize);
+	GITERR_CHECK_ALLOC(ce);
+
+	if (baselen) {
+		memcpy(ce->fullpath, base, baselen);
+
+		if (base[baselen - 1] != '/')
+			ce->fullpath[baselen++] = '/';
+	}
+	memcpy(&ce->fullpath[baselen], path, pathlen);
+
+	ce->path = &ce->fullpath[baselen];
+	*out = ce;
+
+	return 0;
+}
+
+/* call with attrcache locked */
+static int attr_cache_make_entry(
+	git_attr_file_entry **out, git_repository *repo, const char *path)
+{
+	int error = 0;
+	git_attr_cache *cache = git_repository_attr_cache(repo);
+	git_attr_file_entry *entry = NULL;
+
+	error = git_attr_cache__alloc_file_entry(
+		&entry, git_repository_workdir(repo), path, &cache->pool);
+
+	if (!error) {
+		git_strmap_insert(cache->files, entry->path, entry, &error);
+		if (error > 0)
+			error = 0;
+	}
+
+	*out = entry;
+	return error;
+}
+
+/* insert entry or replace existing if we raced with another thread */
+static int attr_cache_upsert(git_attr_cache *cache, git_attr_file *file)
+{
+	git_attr_file_entry *entry;
+	git_attr_file *old;
+
+	if (attr_cache_lock(cache) < 0)
+		return -1;
+
+	entry = attr_cache_lookup_entry(cache, file->entry->path);
+
+	GIT_REFCOUNT_OWN(file, entry);
+	GIT_REFCOUNT_INC(file);
+
+	/*
+	 * Replace the existing value if another thread has
+	 * created it in the meantime.
+	 */
+	old = git__swap(entry->file[file->source], file);
+
+	if (old) {
+		GIT_REFCOUNT_OWN(old, NULL);
+		git_attr_file__free(old);
+	}
+
+	attr_cache_unlock(cache);
+	return 0;
+}
+
+static int attr_cache_remove(git_attr_cache *cache, git_attr_file *file)
+{
+	int error = 0;
+	git_attr_file_entry *entry;
+	git_attr_file *old = NULL;
+
+	if (!file)
+		return 0;
+
+	if ((error = attr_cache_lock(cache)) < 0)
+		return error;
+
+	if ((entry = attr_cache_lookup_entry(cache, file->entry->path)) != NULL)
+		old = git__compare_and_swap(&entry->file[file->source], file, NULL);
+
+	attr_cache_unlock(cache);
+
+	if (old) {
+		GIT_REFCOUNT_OWN(old, NULL);
+		git_attr_file__free(old);
+	}
+
+	return error;
+}
+
+/* Look up cache entry and file.
+ * - If entry is not present, create it while the cache is locked.
+ * - If file is present, increment refcount before returning it, so the
+ *   cache can be unlocked and it won't go away.
+ */
+static int attr_cache_lookup(
+	git_attr_file **out_file,
+	git_attr_file_entry **out_entry,
+	git_repository *repo,
+	git_attr_session *attr_session,
+	git_attr_file_source source,
+	const char *base,
+	const char *filename)
+{
+	int error = 0;
+	git_buf path = GIT_BUF_INIT;
+	const char *wd = git_repository_workdir(repo), *relfile;
+	git_attr_cache *cache = git_repository_attr_cache(repo);
+	git_attr_file_entry *entry = NULL;
+	git_attr_file *file = NULL;
+
+	/* join base and path as needed */
+	if (base != NULL && git_path_root(filename) < 0) {
+		git_buf *p = attr_session ? &attr_session->tmp : &path;
+
+		if (git_buf_joinpath(p, base, filename) < 0)
+			return -1;
+
+		filename = p->ptr;
+	}
+
+	relfile = filename;
+	if (wd && !git__prefixcmp(relfile, wd))
+		relfile += strlen(wd);
+
+	/* check cache for existing entry */
+	if ((error = attr_cache_lock(cache)) < 0)
+		goto cleanup;
+
+	entry = attr_cache_lookup_entry(cache, relfile);
+	if (!entry)
+		error = attr_cache_make_entry(&entry, repo, relfile);
+	else if (entry->file[source] != NULL) {
+		file = entry->file[source];
+		GIT_REFCOUNT_INC(file);
+	}
+
+	attr_cache_unlock(cache);
+
+cleanup:
+	*out_file  = file;
+	*out_entry = entry;
+
+	git_buf_free(&path);
+	return error;
+}
+
+int git_attr_cache__get(
+	git_attr_file **out,
+	git_repository *repo,
+	git_attr_session *attr_session,
+	git_attr_file_source source,
+	const char *base,
+	const char *filename,
+	git_attr_file_parser parser)
+{
+	int error = 0;
+	git_attr_cache *cache = git_repository_attr_cache(repo);
+	git_attr_file_entry *entry = NULL;
+	git_attr_file *file = NULL, *updated = NULL;
+
+	if ((error = attr_cache_lookup(
+			&file, &entry, repo, attr_session, source, base, filename)) < 0)
+		return error;
+
+	/* load file if we don't have one or if existing one is out of date */
+	if (!file || (error = git_attr_file__out_of_date(repo, attr_session, file)) > 0)
+		error = git_attr_file__load(&updated, repo, attr_session, entry, source, parser);
+
+	/* if we loaded the file, insert into and/or update cache */
+	if (updated) {
+		if ((error = attr_cache_upsert(cache, updated)) < 0)
+			git_attr_file__free(updated);
+		else {
+			git_attr_file__free(file); /* offset incref from lookup */
+			file = updated;
+		}
+	}
+
+	/* if file could not be loaded */
+	if (error < 0) {
+		/* remove existing entry */
+		if (file) {
+			attr_cache_remove(cache, file);
+			git_attr_file__free(file); /* offset incref from lookup */
+			file = NULL;
+		}
+		/* no error if file simply doesn't exist */
+		if (error == GIT_ENOTFOUND) {
+			giterr_clear();
+			error = 0;
+		}
+	}
+
+	*out = file;
+	return error;
+}
+
+bool git_attr_cache__is_cached(
+	git_repository *repo,
+	git_attr_file_source source,
+	const char *filename)
+{
+	git_attr_cache *cache = git_repository_attr_cache(repo);
+	git_strmap *files;
+	khiter_t pos;
+	git_attr_file_entry *entry;
+
+	if (!cache || !(files = cache->files))
+		return false;
+
+	pos = git_strmap_lookup_index(files, filename);
+	if (!git_strmap_valid_index(files, pos))
+		return false;
+
+	entry = git_strmap_value_at(files, pos);
+
+	return entry && (entry->file[source] != NULL);
+}
+
+
+static int attr_cache__lookup_path(
+	char **out, git_config *cfg, const char *key, const char *fallback)
+{
+	git_buf buf = GIT_BUF_INIT;
+	int error;
+	git_config_entry *entry = NULL;
+
+	*out = NULL;
+
+	if ((error = git_config__lookup_entry(&entry, cfg, key, false)) < 0)
+		return error;
+
+	if (entry) {
+		const char *cfgval = entry->value;
+
+		/* expand leading ~/ as needed */
+		if (cfgval && cfgval[0] == '~' && cfgval[1] == '/') {
+			if (! (error = git_sysdir_expand_global_file(&buf, &cfgval[2])))
+				*out = git_buf_detach(&buf);
+		} else if (cfgval) {
+			*out = git__strdup(cfgval);
+		}
+	}
+	else if (!git_sysdir_find_xdg_file(&buf, fallback)) {
+		*out = git_buf_detach(&buf);
+	}
+
+	git_config_entry_free(entry);
+	git_buf_free(&buf);
+
+	return error;
+}
+
+static void attr_cache__free(git_attr_cache *cache)
+{
+	bool unlock;
+
+	if (!cache)
+		return;
+
+	unlock = (attr_cache_lock(cache) == 0);
+
+	if (cache->files != NULL) {
+		git_attr_file_entry *entry;
+		git_attr_file *file;
+		int i;
+
+		git_strmap_foreach_value(cache->files, entry, {
+			for (i = 0; i < GIT_ATTR_FILE_NUM_SOURCES; ++i) {
+				if ((file = git__swap(entry->file[i], NULL)) != NULL) {
+					GIT_REFCOUNT_OWN(file, NULL);
+					git_attr_file__free(file);
+				}
+			}
+		});
+		git_strmap_free(cache->files);
+	}
+
+	if (cache->macros != NULL) {
+		git_attr_rule *rule;
+
+		git_strmap_foreach_value(cache->macros, rule, {
+			git_attr_rule__free(rule);
+		});
+		git_strmap_free(cache->macros);
+	}
+
+	git_pool_clear(&cache->pool);
+
+	git__free(cache->cfg_attr_file);
+	cache->cfg_attr_file = NULL;
+
+	git__free(cache->cfg_excl_file);
+	cache->cfg_excl_file = NULL;
+
+	if (unlock)
+		attr_cache_unlock(cache);
+	git_mutex_free(&cache->lock);
+
+	git__free(cache);
+}
+
+int git_attr_cache__init(git_repository *repo)
+{
+	int ret = 0;
+	git_attr_cache *cache = git_repository_attr_cache(repo);
+	git_config *cfg = NULL;
+
+	if (cache)
+		return 0;
+
+	cache = git__calloc(1, sizeof(git_attr_cache));
+	GITERR_CHECK_ALLOC(cache);
+
+	/* set up lock */
+	if (git_mutex_init(&cache->lock) < 0) {
+		giterr_set(GITERR_OS, "unable to initialize lock for attr cache");
+		git__free(cache);
+		return -1;
+	}
+
+	if ((ret = git_repository_config_snapshot(&cfg, repo)) < 0)
+		goto cancel;
+
+	/* cache config settings for attributes and ignores */
+	ret = attr_cache__lookup_path(
+		&cache->cfg_attr_file, cfg, GIT_ATTR_CONFIG, GIT_ATTR_FILE_XDG);
+	if (ret < 0)
+		goto cancel;
+
+	ret = attr_cache__lookup_path(
+		&cache->cfg_excl_file, cfg, GIT_IGNORE_CONFIG, GIT_IGNORE_FILE_XDG);
+	if (ret < 0)
+		goto cancel;
+
+	/* allocate hashtable for attribute and ignore file contents,
+	 * hashtable for attribute macros, and string pool
+	 */
+	if ((ret = git_strmap_alloc(&cache->files)) < 0 ||
+		(ret = git_strmap_alloc(&cache->macros)) < 0)
+		goto cancel;
+
+	git_pool_init(&cache->pool, 1);
+
+	cache = git__compare_and_swap(&repo->attrcache, NULL, cache);
+	if (cache)
+		goto cancel; /* raced with another thread, free this but no error */
+
+	git_config_free(cfg);
+
+	/* insert default macros */
+	return git_attr_add_macro(repo, "binary", "-diff -crlf -text");
+
+cancel:
+	attr_cache__free(cache);
+	git_config_free(cfg);
+	return ret;
+}
+
+void git_attr_cache_flush(git_repository *repo)
+{
+	git_attr_cache *cache;
+
+	/* this could be done less expensively, but for now, we'll just free
+	 * the entire attrcache and let the next use reinitialize it...
+	 */
+	if (repo && (cache = git__swap(repo->attrcache, NULL)) != NULL)
+		attr_cache__free(cache);
+}
+
+int git_attr_cache__insert_macro(git_repository *repo, git_attr_rule *macro)
+{
+	git_attr_cache *cache = git_repository_attr_cache(repo);
+	git_strmap *macros = cache->macros;
+	int error;
+
+	/* TODO: generate warning log if (macro->assigns.length == 0) */
+	if (macro->assigns.length == 0)
+		return 0;
+
+	if (attr_cache_lock(cache) < 0) {
+		giterr_set(GITERR_OS, "unable to get attr cache lock");
+		error = -1;
+	} else {
+		git_strmap_insert(macros, macro->match.pattern, macro, &error);
+		git_mutex_unlock(&cache->lock);
+	}
+
+	return (error < 0) ? -1 : 0;
+}
+
+git_attr_rule *git_attr_cache__lookup_macro(
+	git_repository *repo, const char *name)
+{
+	git_strmap *macros = git_repository_attr_cache(repo)->macros;
+	khiter_t pos;
+
+	pos = git_strmap_lookup_index(macros, name);
+
+	if (!git_strmap_valid_index(macros, pos))
+		return NULL;
+
+	return (git_attr_rule *)git_strmap_value_at(macros, pos);
+}
+

vendor/libgit2-sys/libgit2/src/attrcache.h

diff --git a/vendor/libgit2-sys/libgit2/src/attrcache.h b/vendor/libgit2-sys/libgit2/src/attrcache.h
new file mode 100644
index 0000000..f528911
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/attrcache.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_attrcache_h__
+#define INCLUDE_attrcache_h__
+
+#include "common.h"
+
+#include "attr_file.h"
+#include "strmap.h"
+
+#define GIT_ATTR_CONFIG       "core.attributesfile"
+#define GIT_IGNORE_CONFIG     "core.excludesfile"
+
+typedef struct {
+	char *cfg_attr_file; /* cached value of core.attributesfile */
+	char *cfg_excl_file; /* cached value of core.excludesfile */
+	git_strmap *files;	 /* hash path to git_attr_cache_entry records */
+	git_strmap *macros;	 /* hash name to vector<git_attr_assignment> */
+	git_mutex lock;
+	git_pool  pool;
+} git_attr_cache;
+
+extern int git_attr_cache__init(git_repository *repo);
+
+/* get file - loading and reload as needed */
+extern int git_attr_cache__get(
+	git_attr_file **file,
+	git_repository *repo,
+	git_attr_session *attr_session,
+	git_attr_file_source source,
+	const char *base,
+	const char *filename,
+	git_attr_file_parser parser);
+
+extern bool git_attr_cache__is_cached(
+	git_repository *repo,
+	git_attr_file_source source,
+	const char *path);
+
+extern int git_attr_cache__alloc_file_entry(
+	git_attr_file_entry **out,
+	const char *base,
+	const char *path,
+	git_pool *pool);
+
+extern int git_attr_cache__insert_macro(
+	git_repository *repo, git_attr_rule *macro);
+
+extern git_attr_rule *git_attr_cache__lookup_macro(
+	git_repository *repo, const char *name);
+
+#endif

vendor/libgit2-sys/libgit2/src/bitvec.h

diff --git a/vendor/libgit2-sys/libgit2/src/bitvec.h b/vendor/libgit2-sys/libgit2/src/bitvec.h
new file mode 100644
index 0000000..544832d
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/bitvec.h
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_bitvec_h__
+#define INCLUDE_bitvec_h__
+
+#include "common.h"
+
+/*
+ * This is a silly little fixed length bit vector type that will store
+ * vectors of 64 bits or less directly in the structure and allocate
+ * memory for vectors longer than 64 bits.  You can use the two versions
+ * transparently through the API and avoid heap allocation completely when
+ * using a short bit vector as a result.
+ */
+typedef struct {
+	size_t length;
+	union {
+		uint64_t *words;
+		uint64_t bits;
+	} u;
+} git_bitvec;
+
+GIT_INLINE(int) git_bitvec_init(git_bitvec *bv, size_t capacity)
+{
+	memset(bv, 0x0, sizeof(*bv));
+
+	if (capacity >= 64) {
+		bv->length = (capacity / 64) + 1;
+		bv->u.words = git__calloc(bv->length, sizeof(uint64_t));
+		if (!bv->u.words)
+			return -1;
+	}
+
+	return 0;
+}
+
+#define GIT_BITVEC_MASK(BIT) ((uint64_t)1 << (BIT % 64))
+#define GIT_BITVEC_WORD(BV, BIT) (BV->length ? &BV->u.words[BIT / 64] : &BV->u.bits)
+
+GIT_INLINE(void) git_bitvec_set(git_bitvec *bv, size_t bit, bool on)
+{
+	uint64_t *word = GIT_BITVEC_WORD(bv, bit);
+	uint64_t mask = GIT_BITVEC_MASK(bit);
+
+	if (on)
+		*word |= mask;
+	else
+		*word &= ~mask;
+}
+
+GIT_INLINE(bool) git_bitvec_get(git_bitvec *bv, size_t bit)
+{
+	uint64_t *word = GIT_BITVEC_WORD(bv, bit);
+	return (*word & GIT_BITVEC_MASK(bit)) != 0;
+}
+
+GIT_INLINE(void) git_bitvec_clear(git_bitvec *bv)
+{
+	if (!bv->length)
+		bv->u.bits = 0;
+	else
+		memset(bv->u.words, 0x0, bv->length * sizeof(uint64_t));
+}
+
+GIT_INLINE(void) git_bitvec_free(git_bitvec *bv)
+{
+	if (bv->length)
+		git__free(bv->u.words);
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/blame.c

diff --git a/vendor/libgit2-sys/libgit2/src/blame.c b/vendor/libgit2-sys/libgit2/src/blame.c
new file mode 100644
index 0000000..a923bf0
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/blame.c
@@ -0,0 +1,517 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "blame.h"
+
+#include "git2/commit.h"
+#include "git2/revparse.h"
+#include "git2/revwalk.h"
+#include "git2/tree.h"
+#include "git2/diff.h"
+#include "git2/blob.h"
+#include "git2/signature.h"
+#include "util.h"
+#include "repository.h"
+#include "blame_git.h"
+
+
+static int hunk_byfinalline_search_cmp(const void *key, const void *entry)
+{
+	git_blame_hunk *hunk = (git_blame_hunk*)entry;
+
+	size_t lineno = *(size_t*)key;
+	size_t lines_in_hunk = hunk->lines_in_hunk;
+	size_t final_start_line_number = hunk->final_start_line_number;
+
+	if (lineno < final_start_line_number)
+		return -1;
+	if (lineno >= final_start_line_number + lines_in_hunk)
+		return 1;
+	return 0;
+}
+
+static int paths_cmp(const void *a, const void *b) { return git__strcmp((char*)a, (char*)b); }
+static int hunk_cmp(const void *_a, const void *_b)
+{
+	git_blame_hunk *a = (git_blame_hunk*)_a,
+						*b = (git_blame_hunk*)_b;
+
+	return a->final_start_line_number - b->final_start_line_number;
+}
+
+static bool hunk_ends_at_or_before_line(git_blame_hunk *hunk, size_t line)
+{
+	return line >= (hunk->final_start_line_number + hunk->lines_in_hunk - 1);
+}
+
+static bool hunk_starts_at_or_after_line(git_blame_hunk *hunk, size_t line)
+{
+	return line <= hunk->final_start_line_number;
+}
+
+static git_blame_hunk* new_hunk(
+		size_t start,
+		size_t lines,
+		size_t orig_start,
+		const char *path)
+{
+	git_blame_hunk *hunk = git__calloc(1, sizeof(git_blame_hunk));
+	if (!hunk) return NULL;
+
+	hunk->lines_in_hunk = lines;
+	hunk->final_start_line_number = start;
+	hunk->orig_start_line_number = orig_start;
+	hunk->orig_path = path ? git__strdup(path) : NULL;
+
+	return hunk;
+}
+
+static git_blame_hunk* dup_hunk(git_blame_hunk *hunk)
+{
+	git_blame_hunk *newhunk = new_hunk(
+			hunk->final_start_line_number,
+			hunk->lines_in_hunk,
+			hunk->orig_start_line_number,
+			hunk->orig_path);
+
+	if (!newhunk)
+		return NULL;
+
+	git_oid_cpy(&newhunk->orig_commit_id, &hunk->orig_commit_id);
+	git_oid_cpy(&newhunk->final_commit_id, &hunk->final_commit_id);
+	newhunk->boundary = hunk->boundary;
+	git_signature_dup(&newhunk->final_signature, hunk->final_signature);
+	git_signature_dup(&newhunk->orig_signature, hunk->orig_signature);
+	return newhunk;
+}
+
+static void free_hunk(git_blame_hunk *hunk)
+{
+	git__free((void*)hunk->orig_path);
+	git_signature_free(hunk->final_signature);
+	git_signature_free(hunk->orig_signature);
+	git__free(hunk);
+}
+
+/* Starting with the hunk that includes start_line, shift all following hunks'
+ * final_start_line by shift_by lines */
+static void shift_hunks_by(git_vector *v, size_t start_line, int shift_by)
+{
+	size_t i;
+
+	if (!git_vector_bsearch2(&i, v, hunk_byfinalline_search_cmp, &start_line)) {
+		for (; i < v->length; i++) {
+			git_blame_hunk *hunk = (git_blame_hunk*)v->contents[i];
+			hunk->final_start_line_number += shift_by;
+		}
+	}
+}
+
+git_blame* git_blame__alloc(
+	git_repository *repo,
+	git_blame_options opts,
+	const char *path)
+{
+	git_blame *gbr = git__calloc(1, sizeof(git_blame));
+	if (!gbr)
+		return NULL;
+
+	gbr->repository = repo;
+	gbr->options = opts;
+
+	if (git_vector_init(&gbr->hunks, 8, hunk_cmp) < 0 ||
+		git_vector_init(&gbr->paths, 8, paths_cmp) < 0 ||
+		(gbr->path = git__strdup(path)) == NULL ||
+		git_vector_insert(&gbr->paths, git__strdup(path)) < 0)
+	{
+		git_blame_free(gbr);
+		return NULL;
+	}
+
+	return gbr;
+}
+
+void git_blame_free(git_blame *blame)
+{
+	size_t i;
+	git_blame_hunk *hunk;
+
+	if (!blame) return;
+
+	git_vector_foreach(&blame->hunks, i, hunk)
+		free_hunk(hunk);
+	git_vector_free(&blame->hunks);
+
+	git_vector_free_deep(&blame->paths);
+
+	git_array_clear(blame->line_index);
+
+	git__free(blame->path);
+	git_blob_free(blame->final_blob);
+	git__free(blame);
+}
+
+uint32_t git_blame_get_hunk_count(git_blame *blame)
+{
+	assert(blame);
+	return (uint32_t)blame->hunks.length;
+}
+
+const git_blame_hunk *git_blame_get_hunk_byindex(git_blame *blame, uint32_t index)
+{
+	assert(blame);
+	return (git_blame_hunk*)git_vector_get(&blame->hunks, index);
+}
+
+const git_blame_hunk *git_blame_get_hunk_byline(git_blame *blame, size_t lineno)
+{
+	size_t i, new_lineno = lineno;
+	assert(blame);
+
+	if (!git_vector_bsearch2(&i, &blame->hunks, hunk_byfinalline_search_cmp, &new_lineno)) {
+		return git_blame_get_hunk_byindex(blame, (uint32_t)i);
+	}
+
+	return NULL;
+}
+
+static int normalize_options(
+		git_blame_options *out,
+		const git_blame_options *in,
+		git_repository *repo)
+{
+	git_blame_options dummy = GIT_BLAME_OPTIONS_INIT;
+	if (!in) in = &dummy;
+
+	memcpy(out, in, sizeof(git_blame_options));
+
+	/* No newest_commit => HEAD */
+	if (git_oid_iszero(&out->newest_commit)) {
+		if (git_reference_name_to_id(&out->newest_commit, repo, "HEAD") < 0) {
+			return -1;
+		}
+	}
+
+	/* min_line 0 really means 1 */
+	if (!out->min_line) out->min_line = 1;
+	/* max_line 0 really means N, but we don't know N yet */
+
+	/* Fix up option implications */
+	if (out->flags & GIT_BLAME_TRACK_COPIES_ANY_COMMIT_COPIES)
+		out->flags |= GIT_BLAME_TRACK_COPIES_SAME_COMMIT_COPIES;
+	if (out->flags & GIT_BLAME_TRACK_COPIES_SAME_COMMIT_COPIES)
+		out->flags |= GIT_BLAME_TRACK_COPIES_SAME_COMMIT_MOVES;
+	if (out->flags & GIT_BLAME_TRACK_COPIES_SAME_COMMIT_MOVES)
+		out->flags |= GIT_BLAME_TRACK_COPIES_SAME_FILE;
+
+	return 0;
+}
+
+static git_blame_hunk *split_hunk_in_vector(
+		git_vector *vec,
+		git_blame_hunk *hunk,
+		size_t rel_line,
+		bool return_new)
+{
+	size_t new_line_count;
+	git_blame_hunk *nh;
+
+	/* Don't split if already at a boundary */
+	if (rel_line <= 0 ||
+	    rel_line >= hunk->lines_in_hunk)
+	{
+		return hunk;
+	}
+
+	new_line_count = hunk->lines_in_hunk - rel_line;
+	nh = new_hunk(hunk->final_start_line_number + rel_line, new_line_count,
+			hunk->orig_start_line_number + rel_line, hunk->orig_path);
+
+	if (!nh)
+		return NULL;
+
+	git_oid_cpy(&nh->final_commit_id, &hunk->final_commit_id);
+	git_oid_cpy(&nh->orig_commit_id, &hunk->orig_commit_id);
+
+	/* Adjust hunk that was split */
+	hunk->lines_in_hunk -= new_line_count;
+	git_vector_insert_sorted(vec, nh, NULL);
+	{
+		git_blame_hunk *ret = return_new ? nh : hunk;
+		return ret;
+	}
+}
+
+/*
+ * Construct a list of char indices for where lines begin
+ * Adapted from core git:
+ * https://github.com/gitster/git/blob/be5c9fb9049ed470e7005f159bb923a5f4de1309/builtin/blame.c#L1760-L1789
+ */
+static int index_blob_lines(git_blame *blame)
+{
+    const char *buf = blame->final_buf;
+    git_off_t len = blame->final_buf_size;
+    int num = 0, incomplete = 0, bol = 1;
+    size_t *i;
+
+    if (len && buf[len-1] != '\n')
+        incomplete++; /* incomplete line at the end */
+    while (len--) {
+        if (bol) {
+            i = git_array_alloc(blame->line_index);
+            GITERR_CHECK_ALLOC(i);
+            *i = buf - blame->final_buf;
+            bol = 0;
+        }
+        if (*buf++ == '\n') {
+            num++;
+            bol = 1;
+        }
+    }
+    i = git_array_alloc(blame->line_index);
+    GITERR_CHECK_ALLOC(i);
+    *i = buf - blame->final_buf;
+    blame->num_lines = num + incomplete;
+    return blame->num_lines;
+}
+
+static git_blame_hunk* hunk_from_entry(git_blame__entry *e)
+{
+	git_blame_hunk *h = new_hunk(
+			e->lno+1, e->num_lines, e->s_lno+1, e->suspect->path);
+
+	if (!h)
+		return NULL;
+
+	git_oid_cpy(&h->final_commit_id, git_commit_id(e->suspect->commit));
+	git_oid_cpy(&h->orig_commit_id, git_commit_id(e->suspect->commit));
+	git_signature_dup(&h->final_signature, git_commit_author(e->suspect->commit));
+	git_signature_dup(&h->orig_signature, git_commit_author(e->suspect->commit));
+	h->boundary = e->is_boundary ? 1 : 0;
+	return h;
+}
+
+static int load_blob(git_blame *blame)
+{
+	int error;
+
+	if (blame->final_blob) return 0;
+
+	error = git_commit_lookup(&blame->final, blame->repository, &blame->options.newest_commit);
+	if (error < 0)
+		goto cleanup;
+	error = git_object_lookup_bypath((git_object**)&blame->final_blob,
+			(git_object*)blame->final, blame->path, GIT_OBJ_BLOB);
+
+cleanup:
+	return error;
+}
+
+static int blame_internal(git_blame *blame)
+{
+	int error;
+	git_blame__entry *ent = NULL;
+	git_blame__origin *o;
+
+	if ((error = load_blob(blame)) < 0 ||
+	    (error = git_blame__get_origin(&o, blame, blame->final, blame->path)) < 0)
+		goto cleanup;
+	blame->final_buf = git_blob_rawcontent(blame->final_blob);
+	blame->final_buf_size = git_blob_rawsize(blame->final_blob);
+
+	ent = git__calloc(1, sizeof(git_blame__entry));
+	GITERR_CHECK_ALLOC(ent);
+
+	ent->num_lines = index_blob_lines(blame);
+	ent->lno = blame->options.min_line - 1;
+	ent->num_lines = ent->num_lines - blame->options.min_line + 1;
+	if (blame->options.max_line > 0)
+		ent->num_lines = blame->options.max_line - blame->options.min_line + 1;
+	ent->s_lno = ent->lno;
+	ent->suspect = o;
+
+	blame->ent = ent;
+
+	error = git_blame__like_git(blame, blame->options.flags);
+
+cleanup:
+	for (ent = blame->ent; ent; ) {
+		git_blame__entry *e = ent->next;
+		git_blame_hunk *h = hunk_from_entry(ent);
+
+		git_vector_insert(&blame->hunks, h);
+
+		git_blame__free_entry(ent);
+		ent = e;
+	}
+
+	return error;
+}
+
+/*******************************************************************************
+ * File blaming
+ ******************************************************************************/
+
+int git_blame_file(
+		git_blame **out,
+		git_repository *repo,
+		const char *path,
+		git_blame_options *options)
+{
+	int error = -1;
+	git_blame_options normOptions = GIT_BLAME_OPTIONS_INIT;
+	git_blame *blame = NULL;
+
+	assert(out && repo && path);
+	if ((error = normalize_options(&normOptions, options, repo)) < 0)
+		goto on_error;
+
+	blame = git_blame__alloc(repo, normOptions, path);
+	GITERR_CHECK_ALLOC(blame);
+
+	if ((error = load_blob(blame)) < 0)
+		goto on_error;
+
+	if ((error = blame_internal(blame)) < 0)
+		goto on_error;
+
+	*out = blame;
+	return 0;
+
+on_error:
+	git_blame_free(blame);
+	return error;
+}
+
+/*******************************************************************************
+ * Buffer blaming
+ *******************************************************************************/
+
+static bool hunk_is_bufferblame(git_blame_hunk *hunk)
+{
+	return git_oid_iszero(&hunk->final_commit_id);
+}
+
+static int buffer_hunk_cb(
+	const git_diff_delta *delta,
+	const git_diff_hunk *hunk,
+	void *payload)
+{
+	git_blame *blame = (git_blame*)payload;
+	uint32_t wedge_line;
+
+	GIT_UNUSED(delta);
+
+	wedge_line = (hunk->old_lines == 0) ? hunk->new_start : hunk->old_start;
+	blame->current_diff_line = wedge_line;
+
+	blame->current_hunk = (git_blame_hunk*)git_blame_get_hunk_byline(blame, wedge_line);
+	if (!blame->current_hunk) {
+		/* Line added at the end of the file */
+		blame->current_hunk = new_hunk(wedge_line, 0, wedge_line, blame->path);
+		GITERR_CHECK_ALLOC(blame->current_hunk);
+
+		git_vector_insert(&blame->hunks, blame->current_hunk);
+	} else if (!hunk_starts_at_or_after_line(blame->current_hunk, wedge_line)){
+		/* If this hunk doesn't start between existing hunks, split a hunk up so it does */
+		blame->current_hunk = split_hunk_in_vector(&blame->hunks, blame->current_hunk,
+				wedge_line - blame->current_hunk->orig_start_line_number, true);
+		GITERR_CHECK_ALLOC(blame->current_hunk);
+	}
+
+	return 0;
+}
+
+static int ptrs_equal_cmp(const void *a, const void *b) { return a<b ? -1 : a>b ? 1 : 0; }
+static int buffer_line_cb(
+	const git_diff_delta *delta,
+	const git_diff_hunk *hunk,
+	const git_diff_line *line,
+	void *payload)
+{
+	git_blame *blame = (git_blame*)payload;
+
+	GIT_UNUSED(delta);
+	GIT_UNUSED(hunk);
+	GIT_UNUSED(line);
+
+	if (line->origin == GIT_DIFF_LINE_ADDITION) {
+		if (hunk_is_bufferblame(blame->current_hunk) &&
+		    hunk_ends_at_or_before_line(blame->current_hunk, blame->current_diff_line)) {
+			/* Append to the current buffer-blame hunk */
+			blame->current_hunk->lines_in_hunk++;
+			shift_hunks_by(&blame->hunks, blame->current_diff_line+1, 1);
+		} else {
+			/* Create a new buffer-blame hunk with this line */
+			shift_hunks_by(&blame->hunks, blame->current_diff_line, 1);
+			blame->current_hunk = new_hunk(blame->current_diff_line, 1, 0, blame->path);
+			GITERR_CHECK_ALLOC(blame->current_hunk);
+
+			git_vector_insert_sorted(&blame->hunks, blame->current_hunk, NULL);
+		}
+		blame->current_diff_line++;
+	}
+
+	if (line->origin == GIT_DIFF_LINE_DELETION) {
+		/* Trim the line from the current hunk; remove it if it's now empty */
+		size_t shift_base = blame->current_diff_line + blame->current_hunk->lines_in_hunk+1;
+
+		if (--(blame->current_hunk->lines_in_hunk) == 0) {
+			size_t i;
+			shift_base--;
+			if (!git_vector_search2(&i, &blame->hunks, ptrs_equal_cmp, blame->current_hunk)) {
+				git_vector_remove(&blame->hunks, i);
+				free_hunk(blame->current_hunk);
+				blame->current_hunk = (git_blame_hunk*)git_blame_get_hunk_byindex(blame, (uint32_t)i);
+			}
+		}
+		shift_hunks_by(&blame->hunks, shift_base, -1);
+	}
+	return 0;
+}
+
+int git_blame_buffer(
+		git_blame **out,
+		git_blame *reference,
+		const char *buffer,
+		size_t buffer_len)
+{
+	git_blame *blame;
+	git_diff_options diffopts = GIT_DIFF_OPTIONS_INIT;
+	size_t i;
+	git_blame_hunk *hunk;
+
+	diffopts.context_lines = 0;
+
+	assert(out && reference && buffer && buffer_len);
+
+	blame = git_blame__alloc(reference->repository, reference->options, reference->path);
+	GITERR_CHECK_ALLOC(blame);
+
+	/* Duplicate all of the hunk structures in the reference blame */
+	git_vector_foreach(&reference->hunks, i, hunk) {
+		git_blame_hunk *h = dup_hunk(hunk);
+		GITERR_CHECK_ALLOC(h);
+
+		git_vector_insert(&blame->hunks, h);
+	}
+
+	/* Diff to the reference blob */
+	git_diff_blob_to_buffer(reference->final_blob, blame->path,
+		buffer, buffer_len, blame->path, &diffopts,
+		NULL, NULL, buffer_hunk_cb, buffer_line_cb, blame);
+
+	*out = blame;
+	return 0;
+}
+
+int git_blame_init_options(git_blame_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_blame_options, GIT_BLAME_OPTIONS_INIT);
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/blame.h

diff --git a/vendor/libgit2-sys/libgit2/src/blame.h b/vendor/libgit2-sys/libgit2/src/blame.h
new file mode 100644
index 0000000..8fd3ee5
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/blame.h
@@ -0,0 +1,94 @@
+#ifndef INCLUDE_blame_h__
+#define INCLUDE_blame_h__
+
+#include "common.h"
+
+#include "git2/blame.h"
+#include "vector.h"
+#include "diff.h"
+#include "array.h"
+#include "git2/oid.h"
+
+/*
+ * One blob in a commit that is being suspected
+ */
+typedef struct git_blame__origin {
+	int refcnt;
+	struct git_blame__origin *previous;
+	git_commit *commit;
+	git_blob *blob;
+	char path[GIT_FLEX_ARRAY];
+} git_blame__origin;
+
+/*
+ * Each group of lines is described by a git_blame__entry; it can be split
+ * as we pass blame to the parents.  They form a linked list in the
+ * scoreboard structure, sorted by the target line number.
+ */
+typedef struct git_blame__entry {
+	struct git_blame__entry *prev;
+	struct git_blame__entry *next;
+
+	/* the first line of this group in the final image;
+	 * internally all line numbers are 0 based.
+	 */
+	size_t lno;
+
+	/* how many lines this group has */
+	size_t num_lines;
+
+	/* the commit that introduced this group into the final image */
+	git_blame__origin *suspect;
+
+	/* true if the suspect is truly guilty; false while we have not
+	 * checked if the group came from one of its parents.
+	 */
+	bool guilty;
+
+	/* true if the entry has been scanned for copies in the current parent
+	 */
+	bool scanned;
+
+	/* the line number of the first line of this group in the
+	 * suspect's file; internally all line numbers are 0 based.
+	 */
+	size_t s_lno;
+
+	/* how significant this entry is -- cached to avoid
+	 * scanning the lines over and over.
+	 */
+	unsigned score;
+
+	/* Whether this entry has been tracked to a boundary commit.
+	 */
+	bool is_boundary;
+} git_blame__entry;
+
+struct git_blame {
+	char *path;
+	git_repository *repository;
+	git_blame_options options;
+
+	git_vector hunks;
+	git_vector paths;
+
+	git_blob *final_blob;
+	git_array_t(size_t) line_index;
+
+	size_t current_diff_line;
+	git_blame_hunk *current_hunk;
+
+	/* Scoreboard fields */
+	git_commit *final;
+	git_blame__entry *ent;
+	int num_lines;
+	const char *final_buf;
+	git_off_t final_buf_size;
+};
+
+git_blame *git_blame__alloc(
+	git_repository *repo,
+	git_blame_options opts,
+	const char *path);
+
+#endif

vendor/libgit2-sys/libgit2/src/blame_git.c

diff --git a/vendor/libgit2-sys/libgit2/src/blame_git.c b/vendor/libgit2-sys/libgit2/src/blame_git.c
new file mode 100644
index 0000000..302cd1e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/blame_git.c
@@ -0,0 +1,668 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "blame_git.h"
+
+#include "commit.h"
+#include "blob.h"
+#include "xdiff/xinclude.h"
+#include "diff_xdiff.h"
+
+/*
+ * Origin is refcounted and usually we keep the blob contents to be
+ * reused.
+ */
+static git_blame__origin *origin_incref(git_blame__origin *o)
+{
+	if (o)
+		o->refcnt++;
+	return o;
+}
+
+static void origin_decref(git_blame__origin *o)
+{
+	if (o && --o->refcnt <= 0) {
+		if (o->previous)
+			origin_decref(o->previous);
+		git_blob_free(o->blob);
+		git_commit_free(o->commit);
+		git__free(o);
+	}
+}
+
+/* Given a commit and a path in it, create a new origin structure. */
+static int make_origin(git_blame__origin **out, git_commit *commit, const char *path)
+{
+	git_blame__origin *o;
+	git_object *blob;
+	size_t path_len = strlen(path), alloc_len;
+	int error = 0;
+
+	if ((error = git_object_lookup_bypath(&blob, (git_object*)commit,
+			path, GIT_OBJ_BLOB)) < 0)
+		return error;
+
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, sizeof(*o), path_len);
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, 1);
+	o = git__calloc(1, alloc_len);
+	GITERR_CHECK_ALLOC(o);
+
+	o->commit = commit;
+	o->blob = (git_blob *) blob;
+	o->refcnt = 1;
+	strcpy(o->path, path);
+
+	*out = o;
+
+	return 0;
+}
+
+/* Locate an existing origin or create a new one. */
+int git_blame__get_origin(
+		git_blame__origin **out,
+		git_blame *blame,
+		git_commit *commit,
+		const char *path)
+{
+	git_blame__entry *e;
+
+	for (e = blame->ent; e; e = e->next) {
+		if (e->suspect->commit == commit && !strcmp(e->suspect->path, path)) {
+			*out = origin_incref(e->suspect);
+		}
+	}
+	return make_origin(out, commit, path);
+}
+
+typedef struct blame_chunk_cb_data {
+	git_blame *blame;
+	git_blame__origin *target;
+	git_blame__origin *parent;
+	long tlno;
+	long plno;
+}blame_chunk_cb_data;
+
+static bool same_suspect(git_blame__origin *a, git_blame__origin *b)
+{
+	if (a == b)
+		return true;
+	if (git_oid_cmp(git_commit_id(a->commit), git_commit_id(b->commit)))
+		return false;
+	return 0 == strcmp(a->path, b->path);
+}
+
+/* find the line number of the last line the target is suspected for */
+static bool find_last_in_target(size_t *out, git_blame *blame, git_blame__origin *target)
+{
+	git_blame__entry *e;
+	size_t last_in_target = 0;
+	bool found = false;
+
+	*out = 0;
+
+	for (e=blame->ent; e; e=e->next) {
+		if (e->guilty || !same_suspect(e->suspect, target))
+			continue;
+		if (last_in_target < e->s_lno + e->num_lines) {
+			found = true;
+			last_in_target = e->s_lno + e->num_lines;
+		}
+	}
+
+	*out = last_in_target;
+	return found;
+}
+
+/*
+ * It is known that lines between tlno to same came from parent, and e
+ * has an overlap with that range.  it also is known that parent's
+ * line plno corresponds to e's line tlno.
+ *
+ *                <---- e ----->
+ *                   <------>         (entirely within)
+ *                   <------------>   (extends past)
+ *             <------------>         (starts before)
+ *             <------------------>   (entirely encloses)
+ *
+ * Split e into potentially three parts; before this chunk, the chunk
+ * to be blamed for the parent, and after that portion.
+ */
+static void split_overlap(git_blame__entry *split, git_blame__entry *e,
+		size_t tlno, size_t plno, size_t same, git_blame__origin *parent)
+{
+	size_t chunk_end_lno;
+
+	if (e->s_lno < tlno) {
+		/* there is a pre-chunk part not blamed on the parent */
+		split[0].suspect = origin_incref(e->suspect);
+		split[0].lno = e->lno;
+		split[0].s_lno = e->s_lno;
+		split[0].num_lines = tlno - e->s_lno;
+		split[1].lno = e->lno + tlno - e->s_lno;
+		split[1].s_lno = plno;
+	} else {
+		split[1].lno = e->lno;
+		split[1].s_lno = plno + (e->s_lno - tlno);
+	}
+
+	if (same < e->s_lno + e->num_lines) {
+		/* there is a post-chunk part not blamed on parent */
+		split[2].suspect = origin_incref(e->suspect);
+		split[2].lno = e->lno + (same - e->s_lno);
+		split[2].s_lno = e->s_lno + (same - e->s_lno);
+		split[2].num_lines = e->s_lno + e->num_lines - same;
+		chunk_end_lno = split[2].lno;
+	} else {
+		chunk_end_lno = e->lno + e->num_lines;
+	}
+	split[1].num_lines = chunk_end_lno - split[1].lno;
+
+	/*
+	 * if it turns out there is nothing to blame the parent for, forget about
+	 * the splitting. !split[1].suspect signals this.
+	 */
+	if (split[1].num_lines < 1)
+		return;
+	split[1].suspect = origin_incref(parent);
+}
+
+/*
+ * Link in a new blame entry to the scoreboard. Entries that cover the same
+ * line range have been removed from the scoreboard previously.
+ */
+static void add_blame_entry(git_blame *blame, git_blame__entry *e)
+{
+	git_blame__entry *ent, *prev = NULL;
+
+	origin_incref(e->suspect);
+
+	for (ent = blame->ent; ent && ent->lno < e->lno; ent = ent->next)
+		prev = ent;
+
+	/* prev, if not NULL, is the last one that is below e */
+	e->prev = prev;
+	if (prev) {
+		e->next = prev->next;
+		prev->next = e;
+	} else {
+		e->next = blame->ent;
+		blame->ent = e;
+	}
+	if (e->next)
+		e->next->prev = e;
+}
+
+/*
+ * src typically is on-stack; we want to copy the information in it to
+ * a malloced blame_entry that is already on the linked list of the scoreboard.
+ * The origin of dst loses a refcnt while the origin of src gains one.
+ */
+static void dup_entry(git_blame__entry *dst, git_blame__entry *src)
+{
+	git_blame__entry *p, *n;
+
+	p = dst->prev;
+	n = dst->next;
+	origin_incref(src->suspect);
+	origin_decref(dst->suspect);
+	memcpy(dst, src, sizeof(*src));
+	dst->prev = p;
+	dst->next = n;
+	dst->score = 0;
+}
+
+/*
+ * split_overlap() divided an existing blame e into up to three parts in split.
+ * Adjust the linked list of blames in the scoreboard to reflect the split.
+ */
+static void split_blame(git_blame *blame, git_blame__entry *split, git_blame__entry *e)
+{
+	git_blame__entry *new_entry;
+
+	if (split[0].suspect && split[2].suspect) {
+		/* The first part (reuse storage for the existing entry e */
+		dup_entry(e, &split[0]);
+
+		/* The last part -- me */
+		new_entry = git__malloc(sizeof(*new_entry));
+		memcpy(new_entry, &(split[2]), sizeof(git_blame__entry));
+		add_blame_entry(blame, new_entry);
+
+		/* ... and the middle part -- parent */
+		new_entry = git__malloc(sizeof(*new_entry));
+		memcpy(new_entry, &(split[1]), sizeof(git_blame__entry));
+		add_blame_entry(blame, new_entry);
+	} else if (!split[0].suspect && !split[2].suspect) {
+		/*
+		 * The parent covers the entire area; reuse storage for e and replace it
+		 * with the parent
+		 */
+		dup_entry(e, &split[1]);
+	} else if (split[0].suspect) {
+		/* me and then parent */
+		dup_entry(e, &split[0]);
+		new_entry = git__malloc(sizeof(*new_entry));
+		memcpy(new_entry, &(split[1]), sizeof(git_blame__entry));
+		add_blame_entry(blame, new_entry);
+	} else {
+		/* parent and then me */
+		dup_entry(e, &split[1]);
+		new_entry = git__malloc(sizeof(*new_entry));
+		memcpy(new_entry, &(split[2]), sizeof(git_blame__entry));
+		add_blame_entry(blame, new_entry);
+	}
+}
+
+/* 
+ * After splitting the blame, the origins used by the on-stack blame_entry
+ * should lose one refcnt each.
+ */
+static void decref_split(git_blame__entry *split)
+{
+	int i;
+	for (i=0; i<3; i++)
+		origin_decref(split[i].suspect);
+}
+
+/*
+ * Helper for blame_chunk(). blame_entry e is known to overlap with the patch
+ * hunk; split it and pass blame to the parent.
+ */
+static void blame_overlap(
+		git_blame *blame,
+		git_blame__entry *e,
+		size_t tlno,
+		size_t plno,
+		size_t same,
+		git_blame__origin *parent)
+{
+	git_blame__entry split[3] = {{0}};
+
+	split_overlap(split, e, tlno, plno, same, parent);
+	if (split[1].suspect)
+		split_blame(blame, split, e);
+	decref_split(split);
+}
+
+/*
+ * Process one hunk from the patch between the current suspect for blame_entry
+ * e and its parent. Find and split the overlap, and pass blame to the
+ * overlapping part to the parent.
+ */
+static void blame_chunk(
+		git_blame *blame,
+		size_t tlno,
+		size_t plno,
+		size_t same,
+		git_blame__origin *target,
+		git_blame__origin *parent)
+{
+	git_blame__entry *e;
+
+	for (e = blame->ent; e; e = e->next) {
+		if (e->guilty || !same_suspect(e->suspect, target))
+			continue;
+		if (same <= e->s_lno)
+			continue;
+		if (tlno < e->s_lno + e->num_lines) {
+			blame_overlap(blame, e, tlno, plno, same, parent);
+		}
+	}
+}
+
+static int my_emit(
+	long start_a, long count_a,
+	long start_b, long count_b,
+	void *cb_data)
+{
+	blame_chunk_cb_data *d = (blame_chunk_cb_data *)cb_data;
+
+	blame_chunk(d->blame, d->tlno, d->plno, start_b, d->target, d->parent);
+	d->plno = start_a + count_a;
+	d->tlno = start_b + count_b;
+
+	return 0;
+}
+
+static void trim_common_tail(mmfile_t *a, mmfile_t *b, long ctx)
+{
+	const int blk = 1024;
+	long trimmed = 0, recovered = 0;
+	char *ap = a->ptr + a->size;
+	char *bp = b->ptr + b->size;
+	long smaller = (long)((a->size < b->size) ? a->size : b->size);
+
+	if (ctx)
+		return;
+
+	while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
+		trimmed += blk;
+		ap -= blk;
+		bp -= blk;
+	}
+
+	while (recovered < trimmed)
+		if (ap[recovered++] == '\n')
+			break;
+	a->size -= trimmed - recovered;
+	b->size -= trimmed - recovered;
+}
+
+static int diff_hunks(mmfile_t file_a, mmfile_t file_b, void *cb_data)
+{
+	xpparam_t xpp = {0};
+	xdemitconf_t xecfg = {0};
+	xdemitcb_t ecb = {0};
+
+	xecfg.hunk_func = my_emit;
+	ecb.priv = cb_data;
+
+	trim_common_tail(&file_a, &file_b, 0);
+
+	if (file_a.size > GIT_XDIFF_MAX_SIZE ||
+		file_b.size > GIT_XDIFF_MAX_SIZE) {
+		giterr_set(GITERR_INVALID, "file too large to blame");
+		return -1;
+	}
+
+	return xdl_diff(&file_a, &file_b, &xpp, &xecfg, &ecb);
+}
+
+static void fill_origin_blob(git_blame__origin *o, mmfile_t *file)
+{
+	memset(file, 0, sizeof(*file));
+	if (o->blob) {
+		file->ptr = (char*)git_blob_rawcontent(o->blob);
+		file->size = (size_t)git_blob_rawsize(o->blob);
+	}
+}
+
+static int pass_blame_to_parent(
+		git_blame *blame,
+		git_blame__origin *target,
+		git_blame__origin *parent)
+{
+	size_t last_in_target;
+	mmfile_t file_p, file_o;
+	blame_chunk_cb_data d = { blame, target, parent, 0, 0 };
+
+	if (!find_last_in_target(&last_in_target, blame, target))
+		return 1; /* nothing remains for this target */
+
+	fill_origin_blob(parent, &file_p);
+	fill_origin_blob(target, &file_o);
+
+	if (diff_hunks(file_p, file_o, &d) < 0)
+		return -1;
+
+	/* The reset (i.e. anything after tlno) are the same as the parent */
+	blame_chunk(blame, d.tlno, d.plno, last_in_target, target, parent);
+
+	return 0;
+}
+
+static int paths_on_dup(void **old, void *new)
+{
+	GIT_UNUSED(old);
+	git__free(new);
+	return -1;
+}
+
+static git_blame__origin* find_origin(
+		git_blame *blame,
+		git_commit *parent,
+		git_blame__origin *origin)
+{
+	git_blame__origin *porigin = NULL;
+	git_diff *difflist = NULL;
+	git_diff_options diffopts = GIT_DIFF_OPTIONS_INIT;
+	git_tree *otree=NULL, *ptree=NULL;
+
+	/* Get the trees from this commit and its parent */
+	if (0 != git_commit_tree(&otree, origin->commit) ||
+	    0 != git_commit_tree(&ptree, parent))
+		goto cleanup;
+
+	/* Configure the diff */
+	diffopts.context_lines = 0;
+	diffopts.flags = GIT_DIFF_SKIP_BINARY_CHECK;
+
+	/* Check to see if files we're interested have changed */
+	diffopts.pathspec.count = blame->paths.length;
+	diffopts.pathspec.strings = (char**)blame->paths.contents;
+	if (0 != git_diff_tree_to_tree(&difflist, blame->repository, ptree, otree, &diffopts))
+			goto cleanup;
+
+	if (!git_diff_num_deltas(difflist)) {
+		/* No changes; copy data */
+		git_blame__get_origin(&porigin, blame, parent, origin->path);
+	} else {
+		git_diff_find_options findopts = GIT_DIFF_FIND_OPTIONS_INIT;
+		int i;
+
+		/* Generate a full diff between the two trees */
+		git_diff_free(difflist);
+		diffopts.pathspec.count = 0;
+		if (0 != git_diff_tree_to_tree(&difflist, blame->repository, ptree, otree, &diffopts))
+			goto cleanup;
+
+		/* Let diff find renames */
+		findopts.flags = GIT_DIFF_FIND_RENAMES;
+		if (0 != git_diff_find_similar(difflist, &findopts))
+			goto cleanup;
+
+		/* Find one that matches */
+		for (i=0; i<(int)git_diff_num_deltas(difflist); i++) {
+			const git_diff_delta *delta = git_diff_get_delta(difflist, i);
+
+			if (!git_vector_bsearch(NULL, &blame->paths, delta->new_file.path))
+			{
+				git_vector_insert_sorted(&blame->paths, (void*)git__strdup(delta->old_file.path),
+						paths_on_dup);
+				make_origin(&porigin, parent, delta->old_file.path);
+			}
+		}
+	}
+
+cleanup:
+	git_diff_free(difflist);
+	git_tree_free(otree);
+	git_tree_free(ptree);
+	return porigin;
+}
+
+/*
+ * The blobs of origin and porigin exactly match, so everything origin is
+ * suspected for can be blamed on the parent.
+ */
+static int pass_whole_blame(git_blame *blame,
+		git_blame__origin *origin, git_blame__origin *porigin)
+{
+	git_blame__entry *e;
+
+	if (!porigin->blob &&
+	    git_object_lookup((git_object**)&porigin->blob, blame->repository,
+				git_blob_id(origin->blob), GIT_OBJ_BLOB) < 0)
+		return -1;
+	for (e=blame->ent; e; e=e->next) {
+		if (!same_suspect(e->suspect, origin))
+			continue;
+		origin_incref(porigin);
+		origin_decref(e->suspect);
+		e->suspect = porigin;
+	}
+
+	return 0;
+}
+
+static int pass_blame(git_blame *blame, git_blame__origin *origin, uint32_t opt)
+{
+	git_commit *commit = origin->commit;
+	int i, num_parents;
+	git_blame__origin *sg_buf[16];
+	git_blame__origin *porigin, **sg_origin = sg_buf;
+	int ret, error = 0;
+
+	num_parents = git_commit_parentcount(commit);
+	if (!git_oid_cmp(git_commit_id(commit), &blame->options.oldest_commit))
+		/* Stop at oldest specified commit */
+		num_parents = 0;
+	else if (opt & GIT_BLAME_FIRST_PARENT && num_parents > 1)
+		/* Limit search to the first parent */
+		num_parents = 1;
+
+	if (!num_parents) {
+		git_oid_cpy(&blame->options.oldest_commit, git_commit_id(commit));
+		goto finish;
+	} else if (num_parents < (int)ARRAY_SIZE(sg_buf))
+		memset(sg_buf, 0, sizeof(sg_buf));
+	else {
+		sg_origin = git__calloc(num_parents, sizeof(*sg_origin));
+		GITERR_CHECK_ALLOC(sg_origin);
+	}
+
+	for (i=0; i<num_parents; i++) {
+		git_commit *p;
+		int j, same;
+
+		if (sg_origin[i])
+			continue;
+
+		if ((error = git_commit_parent(&p, origin->commit, i)) < 0)
+			goto finish;
+		porigin = find_origin(blame, p, origin);
+
+		if (!porigin) {
+			/*
+			 * We only have to decrement the parent's
+			 * reference count when no porigin has
+			 * been created, as otherwise the commit
+			 * is assigned to the created object.
+			 */
+			git_commit_free(p);
+			continue;
+		}
+		if (porigin->blob && origin->blob &&
+		    !git_oid_cmp(git_blob_id(porigin->blob), git_blob_id(origin->blob))) {
+			error = pass_whole_blame(blame, origin, porigin);
+			origin_decref(porigin);
+			goto finish;
+		}
+		for (j = same = 0; j<i; j++)
+			if (sg_origin[j] &&
+				 !git_oid_cmp(git_blob_id(sg_origin[j]->blob), git_blob_id(porigin->blob))) {
+				same = 1;
+				break;
+			}
+		if (!same)
+			sg_origin[i] = porigin;
+		else
+			origin_decref(porigin);
+	}
+
+	/* Standard blame */
+	for (i=0; i<num_parents; i++) {
+		git_blame__origin *porigin = sg_origin[i];
+		if (!porigin)
+			continue;
+		if (!origin->previous) {
+			origin_incref(porigin);
+			origin->previous = porigin;
+		}
+
+		if ((ret = pass_blame_to_parent(blame, origin, porigin)) != 0) {
+			if (ret < 0)
+				error = -1;
+
+			goto finish;
+		}
+	}
+
+	/* TODO: optionally find moves in parents' files */
+
+	/* TODO: optionally find copies in parents' files */
+
+finish:
+	for (i=0; i<num_parents; i++)
+		if (sg_origin[i])
+			origin_decref(sg_origin[i]);
+	if (sg_origin != sg_buf)
+		git__free(sg_origin);
+	return error;
+}
+
+/*
+ * If two blame entries that are next to each other came from
+ * contiguous lines in the same origin (i.e. <commit, path> pair),
+ * merge them together.
+ */
+static void coalesce(git_blame *blame)
+{
+	git_blame__entry *ent, *next;
+
+	for (ent=blame->ent; ent && (next = ent->next); ent = next) {
+		if (same_suspect(ent->suspect, next->suspect) &&
+		    ent->guilty == next->guilty &&
+		    ent->s_lno + ent->num_lines == next->s_lno)
+		{
+			ent->num_lines += next->num_lines;
+			ent->next = next->next;
+			if (ent->next)
+				ent->next->prev = ent;
+			origin_decref(next->suspect);
+			git__free(next);
+			ent->score = 0;
+			next = ent; /* again */
+		}
+	}
+}
+
+int git_blame__like_git(git_blame *blame, uint32_t opt)
+{
+	int error = 0;
+
+	while (true) {
+		git_blame__entry *ent;
+		git_blame__origin *suspect = NULL;
+
+		/* Find a suspect to break down */
+		for (ent = blame->ent; !suspect && ent; ent = ent->next)
+			if (!ent->guilty)
+				suspect = ent->suspect;
+		if (!suspect)
+			break;
+
+		/* We'll use this suspect later in the loop, so hold on to it for now. */
+		origin_incref(suspect);
+
+		if ((error = pass_blame(blame, suspect, opt)) < 0)
+			break;
+
+		/* Take responsibility for the remaining entries */
+		for (ent = blame->ent; ent; ent = ent->next) {
+			if (same_suspect(ent->suspect, suspect)) {
+				ent->guilty = true;
+				ent->is_boundary = !git_oid_cmp(
+						git_commit_id(suspect->commit),
+						&blame->options.oldest_commit);
+			}
+		}
+		origin_decref(suspect);
+	}
+
+	if (!error)
+		coalesce(blame);
+
+	return error;
+}
+
+void git_blame__free_entry(git_blame__entry *ent)
+{
+	if (!ent) return;
+	origin_decref(ent->suspect);
+	git__free(ent);
+}

vendor/libgit2-sys/libgit2/src/blame_git.h

diff --git a/vendor/libgit2-sys/libgit2/src/blame_git.h b/vendor/libgit2-sys/libgit2/src/blame_git.h
new file mode 100644
index 0000000..48b85a2
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/blame_git.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_blame_git__
+#define INCLUDE_blame_git__
+
+#include "common.h"
+
+#include "blame.h"
+
+int git_blame__get_origin(
+		git_blame__origin **out,
+		git_blame *sb,
+		git_commit *commit,
+		const char *path);
+void git_blame__free_entry(git_blame__entry *ent);
+int git_blame__like_git(git_blame *sb, uint32_t flags);
+
+#endif

vendor/libgit2-sys/libgit2/src/blob.c

diff --git a/vendor/libgit2-sys/libgit2/src/blob.c b/vendor/libgit2-sys/libgit2/src/blob.c
new file mode 100644
index 0000000..3396fe7
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/blob.c
@@ -0,0 +1,407 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "blob.h"
+
+#include "git2/common.h"
+#include "git2/object.h"
+#include "git2/repository.h"
+#include "git2/odb_backend.h"
+
+#include "filebuf.h"
+#include "filter.h"
+#include "buf_text.h"
+
+const void *git_blob_rawcontent(const git_blob *blob)
+{
+	assert(blob);
+	return git_odb_object_data(blob->odb_object);
+}
+
+git_off_t git_blob_rawsize(const git_blob *blob)
+{
+	assert(blob);
+	return (git_off_t)git_odb_object_size(blob->odb_object);
+}
+
+int git_blob__getbuf(git_buf *buffer, git_blob *blob)
+{
+	return git_buf_set(
+		buffer,
+		git_odb_object_data(blob->odb_object),
+		git_odb_object_size(blob->odb_object));
+}
+
+void git_blob__free(void *blob)
+{
+	git_odb_object_free(((git_blob *)blob)->odb_object);
+	git__free(blob);
+}
+
+int git_blob__parse(void *blob, git_odb_object *odb_obj)
+{
+	assert(blob);
+	git_cached_obj_incref((git_cached_obj *)odb_obj);
+	((git_blob *)blob)->odb_object = odb_obj;
+	return 0;
+}
+
+int git_blob_create_frombuffer(
+	git_oid *id, git_repository *repo, const void *buffer, size_t len)
+{
+	int error;
+	git_odb *odb;
+	git_odb_stream *stream;
+
+	assert(id && repo);
+
+	if ((error = git_repository_odb__weakptr(&odb, repo)) < 0 ||
+		(error = git_odb_open_wstream(&stream, odb, len, GIT_OBJ_BLOB)) < 0)
+		return error;
+
+	if ((error = git_odb_stream_write(stream, buffer, len)) == 0)
+		error = git_odb_stream_finalize_write(id, stream);
+
+	git_odb_stream_free(stream);
+	return error;
+}
+
+static int write_file_stream(
+	git_oid *id, git_odb *odb, const char *path, git_off_t file_size)
+{
+	int fd, error;
+	char buffer[FILEIO_BUFSIZE];
+	git_odb_stream *stream = NULL;
+	ssize_t read_len = -1;
+	git_off_t written = 0;
+
+	if ((error = git_odb_open_wstream(
+			&stream, odb, file_size, GIT_OBJ_BLOB)) < 0)
+		return error;
+
+	if ((fd = git_futils_open_ro(path)) < 0) {
+		git_odb_stream_free(stream);
+		return -1;
+	}
+
+	while (!error && (read_len = p_read(fd, buffer, sizeof(buffer))) > 0) {
+		error = git_odb_stream_write(stream, buffer, read_len);
+		written += read_len;
+	}
+
+	p_close(fd);
+
+	if (written != file_size || read_len < 0) {
+		giterr_set(GITERR_OS, "failed to read file into stream");
+		error = -1;
+	}
+
+	if (!error)
+		error = git_odb_stream_finalize_write(id, stream);
+
+	git_odb_stream_free(stream);
+	return error;
+}
+
+static int write_file_filtered(
+	git_oid *id,
+	git_off_t *size,
+	git_odb *odb,
+	const char *full_path,
+	git_filter_list *fl)
+{
+	int error;
+	git_buf tgt = GIT_BUF_INIT;
+
+	error = git_filter_list_apply_to_file(&tgt, fl, NULL, full_path);
+
+	/* Write the file to disk if it was properly filtered */
+	if (!error) {
+		*size = tgt.size;
+
+		error = git_odb_write(id, odb, tgt.ptr, tgt.size, GIT_OBJ_BLOB);
+	}
+
+	git_buf_free(&tgt);
+	return error;
+}
+
+static int write_symlink(
+	git_oid *id, git_odb *odb, const char *path, size_t link_size)
+{
+	char *link_data;
+	ssize_t read_len;
+	int error;
+
+	link_data = git__malloc(link_size);
+	GITERR_CHECK_ALLOC(link_data);
+
+	read_len = p_readlink(path, link_data, link_size);
+	if (read_len != (ssize_t)link_size) {
+		giterr_set(GITERR_OS, "failed to create blob: cannot read symlink '%s'", path);
+		git__free(link_data);
+		return -1;
+	}
+
+	error = git_odb_write(id, odb, (void *)link_data, link_size, GIT_OBJ_BLOB);
+	git__free(link_data);
+	return error;
+}
+
+int git_blob__create_from_paths(
+	git_oid *id,
+	struct stat *out_st,
+	git_repository *repo,
+	const char *content_path,
+	const char *hint_path,
+	mode_t hint_mode,
+	bool try_load_filters)
+{
+	int error;
+	struct stat st;
+	git_odb *odb = NULL;
+	git_off_t size;
+	mode_t mode;
+	git_buf path = GIT_BUF_INIT;
+
+	assert(hint_path || !try_load_filters);
+
+	if (!content_path) {
+		if (git_repository__ensure_not_bare(repo, "create blob from file") < 0)
+			return GIT_EBAREREPO;
+
+		if (git_buf_joinpath(
+				&path, git_repository_workdir(repo), hint_path) < 0)
+			return -1;
+
+		content_path = path.ptr;
+	}
+
+	if ((error = git_path_lstat(content_path, &st)) < 0 ||
+		(error = git_repository_odb(&odb, repo)) < 0)
+		goto done;
+
+	if (S_ISDIR(st.st_mode)) {
+		giterr_set(GITERR_ODB, "cannot create blob from '%s': it is a directory", content_path);
+		error = GIT_EDIRECTORY;
+		goto done;
+	}
+
+	if (out_st)
+		memcpy(out_st, &st, sizeof(st));
+
+	size = st.st_size;
+	mode = hint_mode ? hint_mode : st.st_mode;
+
+	if (S_ISLNK(mode)) {
+		error = write_symlink(id, odb, content_path, (size_t)size);
+	} else {
+		git_filter_list *fl = NULL;
+
+		if (try_load_filters)
+			/* Load the filters for writing this file to the ODB */
+			error = git_filter_list_load(
+				&fl, repo, NULL, hint_path,
+				GIT_FILTER_TO_ODB, GIT_FILTER_DEFAULT);
+
+		if (error < 0)
+			/* well, that didn't work */;
+		else if (fl == NULL)
+			/* No filters need to be applied to the document: we can stream
+			 * directly from disk */
+			error = write_file_stream(id, odb, content_path, size);
+		else {
+			/* We need to apply one or more filters */
+			error = write_file_filtered(id, &size, odb, content_path, fl);
+
+			git_filter_list_free(fl);
+		}
+
+		/*
+		 * TODO: eventually support streaming filtered files, for files
+		 * which are bigger than a given threshold. This is not a priority
+		 * because applying a filter in streaming mode changes the final
+		 * size of the blob, and without knowing its final size, the blob
+		 * cannot be written in stream mode to the ODB.
+		 *
+		 * The plan is to do streaming writes to a tempfile on disk and then
+		 * opening streaming that file to the ODB, using
+		 * `write_file_stream`.
+		 *
+		 * CAREFULLY DESIGNED APIS YO
+		 */
+	}
+
+done:
+	git_odb_free(odb);
+	git_buf_free(&path);
+
+	return error;
+}
+
+int git_blob_create_fromworkdir(
+	git_oid *id, git_repository *repo, const char *path)
+{
+	return git_blob__create_from_paths(id, NULL, repo, NULL, path, 0, true);
+}
+
+int git_blob_create_fromdisk(
+	git_oid *id, git_repository *repo, const char *path)
+{
+	int error;
+	git_buf full_path = GIT_BUF_INIT;
+	const char *workdir, *hintpath;
+
+	if ((error = git_path_prettify(&full_path, path, NULL)) < 0) {
+		git_buf_free(&full_path);
+		return error;
+	}
+
+	hintpath = git_buf_cstr(&full_path);
+	workdir  = git_repository_workdir(repo);
+
+	if (workdir && !git__prefixcmp(hintpath, workdir))
+		hintpath += strlen(workdir);
+
+	error = git_blob__create_from_paths(
+		id, NULL, repo, git_buf_cstr(&full_path), hintpath, 0, true);
+
+	git_buf_free(&full_path);
+	return error;
+}
+
+typedef struct {
+	git_writestream parent;
+	git_filebuf fbuf;
+	git_repository *repo;
+	char *hintpath;
+} blob_writestream;
+
+static int blob_writestream_close(git_writestream *_stream)
+{
+	blob_writestream *stream = (blob_writestream *) _stream;
+
+	git_filebuf_cleanup(&stream->fbuf);
+	return 0;
+}
+
+static void blob_writestream_free(git_writestream *_stream)
+{
+	blob_writestream *stream = (blob_writestream *) _stream;
+
+	git_filebuf_cleanup(&stream->fbuf);
+	git__free(stream->hintpath);
+	git__free(stream);
+}
+
+static int blob_writestream_write(git_writestream *_stream, const char *buffer, size_t len)
+{
+	blob_writestream *stream = (blob_writestream *) _stream;
+
+	return git_filebuf_write(&stream->fbuf, buffer, len);
+}
+
+int git_blob_create_fromstream(git_writestream **out, git_repository *repo, const char *hintpath)
+{
+	int error;
+	git_buf path = GIT_BUF_INIT;
+	blob_writestream *stream;
+
+	assert(out && repo);
+
+	stream = git__calloc(1, sizeof(blob_writestream));
+	GITERR_CHECK_ALLOC(stream);
+
+	if (hintpath) {
+		stream->hintpath = git__strdup(hintpath);
+		GITERR_CHECK_ALLOC(stream->hintpath);
+	}
+
+	stream->repo = repo;
+	stream->parent.write = blob_writestream_write;
+	stream->parent.close = blob_writestream_close;
+	stream->parent.free  = blob_writestream_free;
+
+	if ((error = git_repository_item_path(&path, repo, GIT_REPOSITORY_ITEM_OBJECTS)) < 0
+		|| (error = git_buf_joinpath(&path, path.ptr, "streamed")) < 0)
+		goto cleanup;
+
+	if ((error = git_filebuf_open_withsize(&stream->fbuf, git_buf_cstr(&path), GIT_FILEBUF_TEMPORARY,
+					       0666, 2 * 1024 * 1024)) < 0)
+		goto cleanup;
+
+	*out = (git_writestream *) stream;
+
+cleanup:
+	if (error < 0)
+		blob_writestream_free((git_writestream *) stream);
+
+	git_buf_free(&path);
+	return error;
+}
+
+int git_blob_create_fromstream_commit(git_oid *out, git_writestream *_stream)
+{
+	int error;
+	blob_writestream *stream = (blob_writestream *) _stream;
+
+	/*
+	 * We can make this more officient by avoiding writing to
+	 * disk, but for now let's re-use the helper functions we
+	 * have.
+	 */
+	if ((error = git_filebuf_flush(&stream->fbuf)) < 0)
+		goto cleanup;
+
+	error = git_blob__create_from_paths(out, NULL, stream->repo, stream->fbuf.path_lock,
+					    stream->hintpath, 0, !!stream->hintpath);
+
+cleanup:
+	blob_writestream_free(_stream);
+	return error;
+
+}
+
+int git_blob_is_binary(const git_blob *blob)
+{
+	git_buf content = GIT_BUF_INIT;
+
+	assert(blob);
+
+	git_buf_attach_notowned(&content, blob->odb_object->buffer,
+		min(blob->odb_object->cached.size,
+		GIT_FILTER_BYTES_TO_CHECK_NUL));
+	return git_buf_text_is_binary(&content);
+}
+
+int git_blob_filtered_content(
+	git_buf *out,
+	git_blob *blob,
+	const char *path,
+	int check_for_binary_data)
+{
+	int error = 0;
+	git_filter_list *fl = NULL;
+
+	assert(blob && path && out);
+
+	git_buf_sanitize(out);
+
+	if (check_for_binary_data && git_blob_is_binary(blob))
+		return 0;
+
+	if (!(error = git_filter_list_load(
+			&fl, git_blob_owner(blob), blob, path,
+			GIT_FILTER_TO_WORKTREE, GIT_FILTER_DEFAULT))) {
+
+		error = git_filter_list_apply_to_blob(out, fl, blob);
+
+		git_filter_list_free(fl);
+	}
+
+	return error;
+}

vendor/libgit2-sys/libgit2/src/blob.h

diff --git a/vendor/libgit2-sys/libgit2/src/blob.h b/vendor/libgit2-sys/libgit2/src/blob.h
new file mode 100644
index 0000000..3f1f977
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/blob.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_blob_h__
+#define INCLUDE_blob_h__
+
+#include "common.h"
+
+#include "git2/blob.h"
+#include "repository.h"
+#include "odb.h"
+#include "fileops.h"
+
+struct git_blob {
+	git_object object;
+	git_odb_object *odb_object;
+};
+
+void git_blob__free(void *blob);
+int git_blob__parse(void *blob, git_odb_object *obj);
+int git_blob__getbuf(git_buf *buffer, git_blob *blob);
+
+extern int git_blob__create_from_paths(
+	git_oid *out_oid,
+	struct stat *out_st,
+	git_repository *repo,
+	const char *full_path,
+	const char *hint_path,
+	mode_t hint_mode,
+	bool apply_filters);
+
+#endif

vendor/libgit2-sys/libgit2/src/branch.c

diff --git a/vendor/libgit2-sys/libgit2/src/branch.c b/vendor/libgit2-sys/libgit2/src/branch.c
new file mode 100644
index 0000000..42addc2
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/branch.c
@@ -0,0 +1,699 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "branch.h"
+
+#include "commit.h"
+#include "tag.h"
+#include "config.h"
+#include "refspec.h"
+#include "refs.h"
+#include "remote.h"
+#include "annotated_commit.h"
+#include "worktree.h"
+
+#include "git2/branch.h"
+
+static int retrieve_branch_reference(
+	git_reference **branch_reference_out,
+	git_repository *repo,
+	const char *branch_name,
+	int is_remote)
+{
+	git_reference *branch = NULL;
+	int error = 0;
+	char *prefix;
+	git_buf ref_name = GIT_BUF_INIT;
+
+	prefix = is_remote ? GIT_REFS_REMOTES_DIR : GIT_REFS_HEADS_DIR;
+
+	if ((error = git_buf_joinpath(&ref_name, prefix, branch_name)) < 0)
+		/* OOM */;
+	else if ((error = git_reference_lookup(&branch, repo, ref_name.ptr)) < 0)
+		giterr_set(
+			GITERR_REFERENCE, "cannot locate %s branch '%s'",
+			is_remote ? "remote-tracking" : "local", branch_name);
+
+	*branch_reference_out = branch; /* will be NULL on error */
+
+	git_buf_free(&ref_name);
+	return error;
+}
+
+static int not_a_local_branch(const char *reference_name)
+{
+	giterr_set(
+		GITERR_INVALID,
+		"reference '%s' is not a local branch.", reference_name);
+	return -1;
+}
+
+static int create_branch(
+	git_reference **ref_out,
+	git_repository *repository,
+	const char *branch_name,
+	const git_commit *commit,
+	const char *from,
+	int force)
+{
+	int is_unmovable_head = 0;
+	git_reference *branch = NULL;
+	git_buf canonical_branch_name = GIT_BUF_INIT,
+			  log_message = GIT_BUF_INIT;
+	int error = -1;
+	int bare = git_repository_is_bare(repository);
+
+	assert(branch_name && commit && ref_out);
+	assert(git_object_owner((const git_object *)commit) == repository);
+
+	if (!git__strcmp(branch_name, "HEAD")) {
+		giterr_set(GITERR_REFERENCE, "'HEAD' is not a valid branch name");
+		error = -1;
+		goto cleanup;
+	}
+
+	if (force && !bare && git_branch_lookup(&branch, repository, branch_name, GIT_BRANCH_LOCAL) == 0) {
+		error = git_branch_is_head(branch);
+		git_reference_free(branch);
+		branch = NULL;
+
+		if (error < 0)
+			goto cleanup;
+
+		is_unmovable_head = error;
+	}
+
+	if (is_unmovable_head && force) {
+		giterr_set(GITERR_REFERENCE, "cannot force update branch '%s' as it is "
+			"the current HEAD of the repository.", branch_name);
+		error = -1;
+		goto cleanup;
+	}
+
+	if (git_buf_joinpath(&canonical_branch_name, GIT_REFS_HEADS_DIR, branch_name) < 0)
+		goto cleanup;
+
+	if (git_buf_printf(&log_message, "branch: Created from %s", from) < 0)
+		goto cleanup;
+
+	error = git_reference_create(&branch, repository,
+		git_buf_cstr(&canonical_branch_name), git_commit_id(commit), force,
+		git_buf_cstr(&log_message));
+
+	if (!error)
+		*ref_out = branch;
+
+cleanup:
+	git_buf_free(&canonical_branch_name);
+	git_buf_free(&log_message);
+	return error;
+}
+
+int git_branch_create(
+	git_reference **ref_out,
+	git_repository *repository,
+	const char *branch_name,
+	const git_commit *commit,
+	int force)
+{
+	return create_branch(ref_out, repository, branch_name, commit, git_oid_tostr_s(git_commit_id(commit)), force);
+}
+
+int git_branch_create_from_annotated(
+	git_reference **ref_out,
+	git_repository *repository,
+	const char *branch_name,
+	const git_annotated_commit *commit,
+	int force)
+{
+	return create_branch(ref_out,
+		repository, branch_name, commit->commit, commit->description, force);
+}
+
+static int branch_equals(git_repository *repo, const char *path, void *payload)
+{
+	git_reference *branch = (git_reference *) payload;
+	git_reference *head = NULL;
+	int equal = 0;
+
+	if (git_reference__read_head(&head, repo, path) < 0 ||
+		git_reference_type(head) != GIT_REF_SYMBOLIC)
+		goto done;
+
+	equal = !git__strcmp(head->target.symbolic, branch->name);
+
+done:
+	git_reference_free(head);
+	return equal;
+}
+
+int git_branch_is_checked_out(const git_reference *branch)
+{
+	assert(branch && git_reference_is_branch(branch));
+
+	return git_repository_foreach_head(git_reference_owner(branch),
+		branch_equals, (void *) branch) == 1;
+}
+
+int git_branch_delete(git_reference *branch)
+{
+	int is_head;
+	git_buf config_section = GIT_BUF_INIT;
+	int error = -1;
+
+	assert(branch);
+
+	if (!git_reference_is_branch(branch) && !git_reference_is_remote(branch)) {
+		giterr_set(GITERR_INVALID, "reference '%s' is not a valid branch.",
+			git_reference_name(branch));
+		return GIT_ENOTFOUND;
+	}
+
+	if ((is_head = git_branch_is_head(branch)) < 0)
+		return is_head;
+
+	if (is_head) {
+		giterr_set(GITERR_REFERENCE, "cannot delete branch '%s' as it is "
+			"the current HEAD of the repository.", git_reference_name(branch));
+		return -1;
+	}
+
+	if (git_reference_is_branch(branch) && git_branch_is_checked_out(branch)) {
+		giterr_set(GITERR_REFERENCE, "Cannot delete branch '%s' as it is "
+			"the current HEAD of a linked repository.", git_reference_name(branch));
+		return -1;
+	}
+
+	if (git_buf_join(&config_section, '.', "branch",
+			git_reference_name(branch) + strlen(GIT_REFS_HEADS_DIR)) < 0)
+		goto on_error;
+
+	if (git_config_rename_section(
+		git_reference_owner(branch), git_buf_cstr(&config_section), NULL) < 0)
+		goto on_error;
+
+	error = git_reference_delete(branch);
+
+on_error:
+	git_buf_free(&config_section);
+	return error;
+}
+
+typedef struct {
+	git_reference_iterator *iter;
+	unsigned int flags;
+} branch_iter;
+
+int git_branch_next(git_reference **out, git_branch_t *out_type, git_branch_iterator *_iter)
+{
+	branch_iter *iter = (branch_iter *) _iter;
+	git_reference *ref;
+	int error;
+
+	while ((error = git_reference_next(&ref, iter->iter)) == 0) {
+		if ((iter->flags & GIT_BRANCH_LOCAL) &&
+		    !git__prefixcmp(ref->name, GIT_REFS_HEADS_DIR)) {
+			*out = ref;
+			*out_type = GIT_BRANCH_LOCAL;
+
+			return 0;
+		} else  if ((iter->flags & GIT_BRANCH_REMOTE) &&
+			    !git__prefixcmp(ref->name, GIT_REFS_REMOTES_DIR)) {
+			*out = ref;
+			*out_type = GIT_BRANCH_REMOTE;
+
+			return 0;
+		} else {
+			git_reference_free(ref);
+		}
+	}
+
+	return error;
+}
+
+int git_branch_iterator_new(
+	git_branch_iterator **out,
+	git_repository *repo,
+	git_branch_t list_flags)
+{
+	branch_iter *iter;
+
+	iter = git__calloc(1, sizeof(branch_iter));
+	GITERR_CHECK_ALLOC(iter);
+
+	iter->flags = list_flags;
+
+	if (git_reference_iterator_new(&iter->iter, repo) < 0) {
+		git__free(iter);
+		return -1;
+	}
+
+	*out = (git_branch_iterator *) iter;
+
+	return 0;
+}
+
+void git_branch_iterator_free(git_branch_iterator *_iter)
+{
+	branch_iter *iter = (branch_iter *) _iter;
+
+	if (iter == NULL)
+		return;
+
+	git_reference_iterator_free(iter->iter);
+	git__free(iter);
+}
+
+int git_branch_move(
+	git_reference **out,
+	git_reference *branch,
+	const char *new_branch_name,
+	int force)
+{
+	git_buf new_reference_name = GIT_BUF_INIT,
+	        old_config_section = GIT_BUF_INIT,
+	        new_config_section = GIT_BUF_INIT,
+	        log_message = GIT_BUF_INIT;
+	int error;
+
+	assert(branch && new_branch_name);
+
+	if (!git_reference_is_branch(branch))
+		return not_a_local_branch(git_reference_name(branch));
+
+	if ((error = git_buf_joinpath(&new_reference_name, GIT_REFS_HEADS_DIR, new_branch_name)) < 0)
+		goto done;
+
+	if ((error = git_buf_printf(&log_message, "branch: renamed %s to %s",
+				    git_reference_name(branch), git_buf_cstr(&new_reference_name))) < 0)
+			goto done;
+
+	/* first update ref then config so failure won't trash config */
+
+	error = git_reference_rename(
+		out, branch, git_buf_cstr(&new_reference_name), force,
+		git_buf_cstr(&log_message));
+	if (error < 0)
+		goto done;
+
+	git_buf_join(&old_config_section, '.', "branch",
+		git_reference_name(branch) + strlen(GIT_REFS_HEADS_DIR));
+	git_buf_join(&new_config_section, '.', "branch", new_branch_name);
+
+	error = git_config_rename_section(
+		git_reference_owner(branch),
+		git_buf_cstr(&old_config_section),
+		git_buf_cstr(&new_config_section));
+
+done:
+	git_buf_free(&new_reference_name);
+	git_buf_free(&old_config_section);
+	git_buf_free(&new_config_section);
+	git_buf_free(&log_message);
+
+	return error;
+}
+
+int git_branch_lookup(
+	git_reference **ref_out,
+	git_repository *repo,
+	const char *branch_name,
+	git_branch_t branch_type)
+{
+	assert(ref_out && repo && branch_name);
+
+	return retrieve_branch_reference(ref_out, repo, branch_name, branch_type == GIT_BRANCH_REMOTE);
+}
+
+int git_branch_name(
+	const char **out,
+	const git_reference *ref)
+{
+	const char *branch_name;
+
+	assert(out && ref);
+
+	branch_name = ref->name;
+
+	if (git_reference_is_branch(ref)) {
+		branch_name += strlen(GIT_REFS_HEADS_DIR);
+	} else if (git_reference_is_remote(ref)) {
+		branch_name += strlen(GIT_REFS_REMOTES_DIR);
+	} else {
+		giterr_set(GITERR_INVALID,
+				"reference '%s' is neither a local nor a remote branch.", ref->name);
+		return -1;
+	}
+	*out = branch_name;
+	return 0;
+}
+
+static int retrieve_upstream_configuration(
+	git_buf *out,
+	const git_config *config,
+	const char *canonical_branch_name,
+	const char *format)
+{
+	git_buf buf = GIT_BUF_INIT;
+	int error;
+
+	if (git_buf_printf(&buf, format,
+		canonical_branch_name + strlen(GIT_REFS_HEADS_DIR)) < 0)
+			return -1;
+
+	error = git_config_get_string_buf(out, config, git_buf_cstr(&buf));
+	git_buf_free(&buf);
+	return error;
+}
+
+int git_branch_upstream_name(
+	git_buf *out,
+	git_repository *repo,
+	const char *refname)
+{
+	git_buf remote_name = GIT_BUF_INIT;
+	git_buf merge_name = GIT_BUF_INIT;
+	git_buf buf = GIT_BUF_INIT;
+	int error = -1;
+	git_remote *remote = NULL;
+	const git_refspec *refspec;
+	git_config *config;
+
+	assert(out && refname);
+
+	git_buf_sanitize(out);
+
+	if (!git_reference__is_branch(refname))
+		return not_a_local_branch(refname);
+
+	if ((error = git_repository_config_snapshot(&config, repo)) < 0)
+		return error;
+
+	if ((error = retrieve_upstream_configuration(
+		&remote_name, config, refname, "branch.%s.remote")) < 0)
+			goto cleanup;
+
+	if ((error = retrieve_upstream_configuration(
+		&merge_name, config, refname, "branch.%s.merge")) < 0)
+			goto cleanup;
+
+	if (git_buf_len(&remote_name) == 0 || git_buf_len(&merge_name) == 0) {
+		giterr_set(GITERR_REFERENCE,
+			"branch '%s' does not have an upstream", refname);
+		error = GIT_ENOTFOUND;
+		goto cleanup;
+	}
+
+	if (strcmp(".", git_buf_cstr(&remote_name)) != 0) {
+		if ((error = git_remote_lookup(&remote, repo, git_buf_cstr(&remote_name))) < 0)
+			goto cleanup;
+
+		refspec = git_remote__matching_refspec(remote, git_buf_cstr(&merge_name));
+		if (!refspec) {
+			error = GIT_ENOTFOUND;
+			goto cleanup;
+		}
+
+		if (git_refspec_transform(&buf, refspec, git_buf_cstr(&merge_name)) < 0)
+			goto cleanup;
+	} else
+		if (git_buf_set(&buf, git_buf_cstr(&merge_name), git_buf_len(&merge_name)) < 0)
+			goto cleanup;
+
+	error = git_buf_set(out, git_buf_cstr(&buf), git_buf_len(&buf));
+
+cleanup:
+	git_config_free(config);
+	git_remote_free(remote);
+	git_buf_free(&remote_name);
+	git_buf_free(&merge_name);
+	git_buf_free(&buf);
+	return error;
+}
+
+int git_branch_upstream_remote(git_buf *buf, git_repository *repo, const char *refname)
+{
+	int error;
+	git_config *cfg;
+
+	if (!git_reference__is_branch(refname))
+		return not_a_local_branch(refname);
+
+	if ((error = git_repository_config__weakptr(&cfg, repo)) < 0)
+		return error;
+
+	git_buf_sanitize(buf);
+
+	if ((error = retrieve_upstream_configuration(buf, cfg, refname, "branch.%s.remote")) < 0)
+		return error;
+
+	if (git_buf_len(buf) == 0) {
+		giterr_set(GITERR_REFERENCE, "branch '%s' does not have an upstream remote", refname);
+		error = GIT_ENOTFOUND;
+		git_buf_clear(buf);
+	}
+
+	return error;
+}
+
+int git_branch_remote_name(git_buf *buf, git_repository *repo, const char *refname)
+{
+	git_strarray remote_list = {0};
+	size_t i;
+	git_remote *remote;
+	const git_refspec *fetchspec;
+	int error = 0;
+	char *remote_name = NULL;
+
+	assert(buf && repo && refname);
+
+	git_buf_sanitize(buf);
+
+	/* Verify that this is a remote branch */
+	if (!git_reference__is_remote(refname)) {
+		giterr_set(GITERR_INVALID, "reference '%s' is not a remote branch.",
+			refname);
+		error = GIT_ERROR;
+		goto cleanup;
+	}
+
+	/* Get the remotes */
+	if ((error = git_remote_list(&remote_list, repo)) < 0)
+		goto cleanup;
+
+	/* Find matching remotes */
+	for (i = 0; i < remote_list.count; i++) {
+		if ((error = git_remote_lookup(&remote, repo, remote_list.strings[i])) < 0)
+			continue;
+
+		fetchspec = git_remote__matching_dst_refspec(remote, refname);
+		if (fetchspec) {
+			/* If we have not already set out yet, then set
+			 * it to the matching remote name. Otherwise
+			 * multiple remotes match this reference, and it
+			 * is ambiguous. */
+			if (!remote_name) {
+				remote_name = remote_list.strings[i];
+			} else {
+				git_remote_free(remote);
+
+				giterr_set(GITERR_REFERENCE,
+					"reference '%s' is ambiguous", refname);
+				error = GIT_EAMBIGUOUS;
+				goto cleanup;
+			}
+		}
+
+		git_remote_free(remote);
+	}
+
+	if (remote_name) {
+		git_buf_clear(buf);
+		error = git_buf_puts(buf, remote_name);
+	} else {
+		giterr_set(GITERR_REFERENCE,
+			"could not determine remote for '%s'", refname);
+		error = GIT_ENOTFOUND;
+	}
+
+cleanup:
+	if (error < 0)
+		git_buf_free(buf);
+
+	git_strarray_free(&remote_list);
+	return error;
+}
+
+int git_branch_upstream(
+	git_reference **tracking_out,
+	const git_reference *branch)
+{
+	int error;
+	git_buf tracking_name = GIT_BUF_INIT;
+
+	if ((error = git_branch_upstream_name(&tracking_name,
+		git_reference_owner(branch), git_reference_name(branch))) < 0)
+			return error;
+
+	error = git_reference_lookup(
+		tracking_out,
+		git_reference_owner(branch),
+		git_buf_cstr(&tracking_name));
+
+	git_buf_free(&tracking_name);
+	return error;
+}
+
+static int unset_upstream(git_config *config, const char *shortname)
+{
+	git_buf buf = GIT_BUF_INIT;
+
+	if (git_buf_printf(&buf, "branch.%s.remote", shortname) < 0)
+		return -1;
+
+	if (git_config_delete_entry(config, git_buf_cstr(&buf)) < 0)
+		goto on_error;
+
+	git_buf_clear(&buf);
+	if (git_buf_printf(&buf, "branch.%s.merge", shortname) < 0)
+		goto on_error;
+
+	if (git_config_delete_entry(config, git_buf_cstr(&buf)) < 0)
+		goto on_error;
+
+	git_buf_free(&buf);
+	return 0;
+
+on_error:
+	git_buf_free(&buf);
+	return -1;
+}
+
+int git_branch_set_upstream(git_reference *branch, const char *upstream_name)
+{
+	git_buf key = GIT_BUF_INIT, value = GIT_BUF_INIT;
+	git_reference *upstream;
+	git_repository *repo;
+	git_remote *remote = NULL;
+	git_config *config;
+	const char *name, *shortname;
+	int local, error;
+	const git_refspec *fetchspec;
+
+	name = git_reference_name(branch);
+	if (!git_reference__is_branch(name))
+		return not_a_local_branch(name);
+
+	if (git_repository_config__weakptr(&config, git_reference_owner(branch)) < 0)
+		return -1;
+
+	shortname = name + strlen(GIT_REFS_HEADS_DIR);
+
+	if (upstream_name == NULL)
+		return unset_upstream(config, shortname);
+
+	repo = git_reference_owner(branch);
+
+	/* First we need to figure out whether it's a branch or remote-tracking */
+	if (git_branch_lookup(&upstream, repo, upstream_name, GIT_BRANCH_LOCAL) == 0)
+		local = 1;
+	else if (git_branch_lookup(&upstream, repo, upstream_name, GIT_BRANCH_REMOTE) == 0)
+		local = 0;
+	else {
+		giterr_set(GITERR_REFERENCE,
+			"cannot set upstream for branch '%s'", shortname);
+		return GIT_ENOTFOUND;
+	}
+
+	/*
+	 * If it's local, the remote is "." and the branch name is
+	 * simply the refname. Otherwise we need to figure out what
+	 * the remote-tracking branch's name on the remote is and use
+	 * that.
+	 */
+	if (local)
+		error = git_buf_puts(&value, ".");
+	else
+		error = git_branch_remote_name(&value, repo, git_reference_name(upstream));
+
+	if (error < 0)
+		goto on_error;
+
+	if (git_buf_printf(&key, "branch.%s.remote", shortname) < 0)
+		goto on_error;
+
+	if (git_config_set_string(config, git_buf_cstr(&key), git_buf_cstr(&value)) < 0)
+		goto on_error;
+
+	if (local) {
+		git_buf_clear(&value);
+		if (git_buf_puts(&value, git_reference_name(upstream)) < 0)
+			goto on_error;
+	} else {
+		/* Get the remoe-tracking branch's refname in its repo */
+		if (git_remote_lookup(&remote, repo, git_buf_cstr(&value)) < 0)
+			goto on_error;
+
+		fetchspec = git_remote__matching_dst_refspec(remote, git_reference_name(upstream));
+		git_buf_clear(&value);
+		if (!fetchspec || git_refspec_rtransform(&value, fetchspec, git_reference_name(upstream)) < 0)
+			goto on_error;
+
+		git_remote_free(remote);
+		remote = NULL;
+	}
+
+	git_buf_clear(&key);
+	if (git_buf_printf(&key, "branch.%s.merge", shortname) < 0)
+		goto on_error;
+
+	if (git_config_set_string(config, git_buf_cstr(&key), git_buf_cstr(&value)) < 0)
+		goto on_error;
+
+	git_reference_free(upstream);
+	git_buf_free(&key);
+	git_buf_free(&value);
+
+	return 0;
+
+on_error:
+	git_reference_free(upstream);
+	git_buf_free(&key);
+	git_buf_free(&value);
+	git_remote_free(remote);
+
+	return -1;
+}
+
+int git_branch_is_head(
+		const git_reference *branch)
+{
+	git_reference *head;
+	bool is_same = false;
+	int error;
+
+	assert(branch);
+
+	if (!git_reference_is_branch(branch))
+		return false;
+
+	error = git_repository_head(&head, git_reference_owner(branch));
+
+	if (error == GIT_EUNBORNBRANCH || error == GIT_ENOTFOUND)
+		return false;
+
+	if (error < 0)
+		return -1;
+
+	is_same = strcmp(
+		git_reference_name(branch),
+		git_reference_name(head)) == 0;
+
+	git_reference_free(head);
+
+	return is_same;
+}

vendor/libgit2-sys/libgit2/src/branch.h

diff --git a/vendor/libgit2-sys/libgit2/src/branch.h b/vendor/libgit2-sys/libgit2/src/branch.h
new file mode 100644
index 0000000..5ae227c
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/branch.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_branch_h__
+#define INCLUDE_branch_h__
+
+#include "common.h"
+
+#include "buffer.h"
+
+int git_branch_upstream__name(
+	git_buf *tracking_name,
+	git_repository *repo,
+	const char *canonical_branch_name);
+
+#endif

vendor/libgit2-sys/libgit2/src/buf_text.c

diff --git a/vendor/libgit2-sys/libgit2/src/buf_text.c b/vendor/libgit2-sys/libgit2/src/buf_text.c
new file mode 100644
index 0000000..306980b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/buf_text.c
@@ -0,0 +1,315 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#include "buf_text.h"
+
+int git_buf_text_puts_escaped(
+	git_buf *buf,
+	const char *string,
+	const char *esc_chars,
+	const char *esc_with)
+{
+	const char *scan;
+	size_t total = 0, esc_len = strlen(esc_with), count, alloclen;
+
+	if (!string)
+		return 0;
+
+	for (scan = string; *scan; ) {
+		/* count run of non-escaped characters */
+		count = strcspn(scan, esc_chars);
+		total += count;
+		scan += count;
+		/* count run of escaped characters */
+		count = strspn(scan, esc_chars);
+		total += count * (esc_len + 1);
+		scan += count;
+	}
+
+	GITERR_CHECK_ALLOC_ADD(&alloclen, total, 1);
+	if (git_buf_grow_by(buf, alloclen) < 0)
+		return -1;
+
+	for (scan = string; *scan; ) {
+		count = strcspn(scan, esc_chars);
+
+		memmove(buf->ptr + buf->size, scan, count);
+		scan += count;
+		buf->size += count;
+
+		for (count = strspn(scan, esc_chars); count > 0; --count) {
+			/* copy escape sequence */
+			memmove(buf->ptr + buf->size, esc_with, esc_len);
+			buf->size += esc_len;
+			/* copy character to be escaped */
+			buf->ptr[buf->size] = *scan;
+			buf->size++;
+			scan++;
+		}
+	}
+
+	buf->ptr[buf->size] = '\0';
+
+	return 0;
+}
+
+void git_buf_text_unescape(git_buf *buf)
+{
+	buf->size = git__unescape(buf->ptr);
+}
+
+int git_buf_text_crlf_to_lf(git_buf *tgt, const git_buf *src)
+{
+	const char *scan = src->ptr;
+	const char *scan_end = src->ptr + src->size;
+	const char *next = memchr(scan, '\r', src->size);
+	size_t new_size;
+	char *out;
+
+	assert(tgt != src);
+
+	if (!next)
+		return git_buf_set(tgt, src->ptr, src->size);
+
+	/* reduce reallocs while in the loop */
+	GITERR_CHECK_ALLOC_ADD(&new_size, src->size, 1);
+	if (git_buf_grow(tgt, new_size) < 0)
+		return -1;
+
+	out = tgt->ptr;
+	tgt->size = 0;
+
+	/* Find the next \r and copy whole chunk up to there to tgt */
+	for (; next; scan = next + 1, next = memchr(scan, '\r', scan_end - scan)) {
+		if (next > scan) {
+			size_t copylen = (size_t)(next - scan);
+			memcpy(out, scan, copylen);
+			out += copylen;
+		}
+
+		/* Do not drop \r unless it is followed by \n */
+		if (next + 1 == scan_end || next[1] != '\n')
+			*out++ = '\r';
+	}
+
+	/* Copy remaining input into dest */
+	if (scan < scan_end) {
+		size_t remaining = (size_t)(scan_end - scan);
+		memcpy(out, scan, remaining);
+		out += remaining;
+	}
+
+	tgt->size = (size_t)(out - tgt->ptr);
+	tgt->ptr[tgt->size] = '\0';
+
+	return 0;
+}
+
+int git_buf_text_lf_to_crlf(git_buf *tgt, const git_buf *src)
+{
+	const char *start = src->ptr;
+	const char *end = start + src->size;
+	const char *scan = start;
+	const char *next = memchr(scan, '\n', src->size);
+	size_t alloclen;
+
+	assert(tgt != src);
+
+	if (!next)
+		return git_buf_set(tgt, src->ptr, src->size);
+
+	/* attempt to reduce reallocs while in the loop */
+	GITERR_CHECK_ALLOC_ADD(&alloclen, src->size, src->size >> 4);
+	GITERR_CHECK_ALLOC_ADD(&alloclen, alloclen, 1);
+	if (git_buf_grow(tgt, alloclen) < 0)
+		return -1;
+	tgt->size = 0;
+
+	for (; next; scan = next + 1, next = memchr(scan, '\n', end - scan)) {
+		size_t copylen = next - scan;
+
+		/* if we find mixed line endings, carry on */
+		if (copylen && next[-1] == '\r')
+			copylen--;
+
+		GITERR_CHECK_ALLOC_ADD(&alloclen, copylen, 3);
+		if (git_buf_grow_by(tgt, alloclen) < 0)
+			return -1;
+
+		if (copylen) {
+			memcpy(tgt->ptr + tgt->size, scan, copylen);
+			tgt->size += copylen;
+		}
+
+		tgt->ptr[tgt->size++] = '\r';
+		tgt->ptr[tgt->size++] = '\n';
+	}
+
+	tgt->ptr[tgt->size] = '\0';
+	return git_buf_put(tgt, scan, end - scan);
+}
+
+int git_buf_text_common_prefix(git_buf *buf, const git_strarray *strings)
+{
+	size_t i;
+	const char *str, *pfx;
+
+	git_buf_clear(buf);
+
+	if (!strings || !strings->count)
+		return 0;
+
+	/* initialize common prefix to first string */
+	if (git_buf_sets(buf, strings->strings[0]) < 0)
+		return -1;
+
+	/* go through the rest of the strings, truncating to shared prefix */
+	for (i = 1; i < strings->count; ++i) {
+
+		for (str = strings->strings[i], pfx = buf->ptr;
+			 *str && *str == *pfx; str++, pfx++)
+			/* scanning */;
+
+		git_buf_truncate(buf, pfx - buf->ptr);
+
+		if (!buf->size)
+			break;
+	}
+
+	return 0;
+}
+
+bool git_buf_text_is_binary(const git_buf *buf)
+{
+	const char *scan = buf->ptr, *end = buf->ptr + buf->size;
+	git_bom_t bom;
+	int printable = 0, nonprintable = 0;
+
+	scan += git_buf_text_detect_bom(&bom, buf);
+
+	if (bom > GIT_BOM_UTF8)
+		return 1;
+
+	while (scan < end) {
+		unsigned char c = *scan++;
+
+		/* Printable characters are those above SPACE (0x1F) excluding DEL,
+		 * and including BS, ESC and FF.
+		 */
+		if ((c > 0x1F && c != 127) || c == '\b' || c == '\033' || c == '\014')
+			printable++;
+		else if (c == '\0')
+			return true;
+		else if (!git__isspace(c))
+			nonprintable++;
+	}
+
+	return ((printable >> 7) < nonprintable);
+}
+
+bool git_buf_text_contains_nul(const git_buf *buf)
+{
+	return (memchr(buf->ptr, '\0', buf->size) != NULL);
+}
+
+int git_buf_text_detect_bom(git_bom_t *bom, const git_buf *buf)
+{
+	const char *ptr;
+	size_t len;
+
+	*bom = GIT_BOM_NONE;
+	/* need at least 2 bytes to look for any BOM */
+	if (buf->size < 2)
+		return 0;
+
+	ptr = buf->ptr;
+	len = buf->size;
+
+	switch (*ptr++) {
+	case 0:
+		if (len >= 4 && ptr[0] == 0 && ptr[1] == '\xFE' && ptr[2] == '\xFF') {
+			*bom = GIT_BOM_UTF32_BE;
+			return 4;
+		}
+		break;
+	case '\xEF':
+		if (len >= 3 && ptr[0] == '\xBB' && ptr[1] == '\xBF') {
+			*bom = GIT_BOM_UTF8;
+			return 3;
+		}
+		break;
+	case '\xFE':
+		if (*ptr == '\xFF') {
+			*bom = GIT_BOM_UTF16_BE;
+			return 2;
+		}
+		break;
+	case '\xFF':
+		if (*ptr != '\xFE')
+			break;
+		if (len >= 4 && ptr[1] == 0 && ptr[2] == 0) {
+			*bom = GIT_BOM_UTF32_LE;
+			return 4;
+		} else {
+			*bom = GIT_BOM_UTF16_LE;
+			return 2;
+		}
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+bool git_buf_text_gather_stats(
+	git_buf_text_stats *stats, const git_buf *buf, bool skip_bom)
+{
+	const char *scan = buf->ptr, *end = buf->ptr + buf->size;
+	int skip;
+
+	memset(stats, 0, sizeof(*stats));
+
+	/* BOM detection */
+	skip = git_buf_text_detect_bom(&stats->bom, buf);
+	if (skip_bom)
+		scan += skip;
+
+	/* Ignore EOF character */
+	if (buf->size > 0 && end[-1] == '\032')
+		end--;
+
+	/* Counting loop */
+	while (scan < end) {
+		unsigned char c = *scan++;
+
+		if (c > 0x1F && c != 0x7F)
+			stats->printable++;
+		else switch (c) {
+			case '\0':
+				stats->nul++;
+				stats->nonprintable++;
+				break;
+			case '\n':
+				stats->lf++;
+				break;
+			case '\r':
+				stats->cr++;
+				if (scan < end && *scan == '\n')
+					stats->crlf++;
+				break;
+			case '\t': case '\f': case '\v': case '\b': case 0x1b: /*ESC*/
+				stats->printable++;
+				break;
+			default:
+				stats->nonprintable++;
+				break;
+			}
+	}
+
+	return (stats->nul > 0 ||
+		((stats->printable >> 7) < stats->nonprintable));
+}

vendor/libgit2-sys/libgit2/src/buf_text.h

diff --git a/vendor/libgit2-sys/libgit2/src/buf_text.h b/vendor/libgit2-sys/libgit2/src/buf_text.h
new file mode 100644
index 0000000..726b0ae
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/buf_text.h
@@ -0,0 +1,122 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_buf_text_h__
+#define INCLUDE_buf_text_h__
+
+#include "common.h"
+
+#include "buffer.h"
+
+typedef enum {
+	GIT_BOM_NONE = 0,
+	GIT_BOM_UTF8 = 1,
+	GIT_BOM_UTF16_LE = 2,
+	GIT_BOM_UTF16_BE = 3,
+	GIT_BOM_UTF32_LE = 4,
+	GIT_BOM_UTF32_BE = 5
+} git_bom_t;
+
+typedef struct {
+	git_bom_t bom; /* BOM found at head of text */
+	unsigned int nul, cr, lf, crlf; /* NUL, CR, LF and CRLF counts */
+	unsigned int printable, nonprintable; /* These are just approximations! */
+} git_buf_text_stats;
+
+/**
+ * Append string to buffer, prefixing each character from `esc_chars` with
+ * `esc_with` string.
+ *
+ * @param buf Buffer to append data to
+ * @param string String to escape and append
+ * @param esc_chars Characters to be escaped
+ * @param esc_with String to insert in from of each found character
+ * @return 0 on success, <0 on failure (probably allocation problem)
+ */
+extern int git_buf_text_puts_escaped(
+	git_buf *buf,
+	const char *string,
+	const char *esc_chars,
+	const char *esc_with);
+
+/**
+ * Append string escaping characters that are regex special
+ */
+GIT_INLINE(int) git_buf_text_puts_escape_regex(git_buf *buf, const char *string)
+{
+	return git_buf_text_puts_escaped(buf, string, "^.[]$()|*+?{}\\", "\\");
+}
+
+/**
+ * Unescape all characters in a buffer in place
+ *
+ * I.e. remove backslashes
+ */
+extern void git_buf_text_unescape(git_buf *buf);
+
+/**
+ * Replace all \r\n with \n.
+ *
+ * @return 0 on success, -1 on memory error
+ */
+extern int git_buf_text_crlf_to_lf(git_buf *tgt, const git_buf *src);
+
+/**
+ * Replace all \n with \r\n. Does not modify existing \r\n.
+ *
+ * @return 0 on success, -1 on memory error
+ */
+extern int git_buf_text_lf_to_crlf(git_buf *tgt, const git_buf *src);
+
+/**
+ * Fill buffer with the common prefix of a array of strings
+ *
+ * Buffer will be set to empty if there is no common prefix
+ */
+extern int git_buf_text_common_prefix(git_buf *buf, const git_strarray *strs);
+
+/**
+ * Check quickly if buffer looks like it contains binary data
+ *
+ * @param buf Buffer to check
+ * @return true if buffer looks like non-text data
+ */
+extern bool git_buf_text_is_binary(const git_buf *buf);
+
+/**
+ * Check quickly if buffer contains a NUL byte
+ *
+ * @param buf Buffer to check
+ * @return true if buffer contains a NUL byte
+ */
+extern bool git_buf_text_contains_nul(const git_buf *buf);
+
+/**
+ * Check if a buffer begins with a UTF BOM
+ *
+ * @param bom Set to the type of BOM detected or GIT_BOM_NONE
+ * @param buf Buffer in which to check the first bytes for a BOM
+ * @return Number of bytes of BOM data (or 0 if no BOM found)
+ */
+extern int git_buf_text_detect_bom(git_bom_t *bom, const git_buf *buf);
+
+/**
+ * Gather stats for a piece of text
+ *
+ * Fill the `stats` structure with counts of unreadable characters, carriage
+ * returns, etc, so it can be used in heuristics.  This automatically skips
+ * a trailing EOF (\032 character).  Also it will look for a BOM at the
+ * start of the text and can be told to skip that as well.
+ *
+ * @param stats Structure to be filled in
+ * @param buf Text to process
+ * @param skip_bom Exclude leading BOM from stats if true
+ * @return Does the buffer heuristically look like binary data
+ */
+extern bool git_buf_text_gather_stats(
+	git_buf_text_stats *stats, const git_buf *buf, bool skip_bom);
+
+#endif

vendor/libgit2-sys/libgit2/src/buffer.c

diff --git a/vendor/libgit2-sys/libgit2/src/buffer.c b/vendor/libgit2-sys/libgit2/src/buffer.c
new file mode 100644
index 0000000..8a58d1a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/buffer.c
@@ -0,0 +1,1029 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#include "buffer.h"
+#include "posix.h"
+#include "git2/buffer.h"
+#include "buf_text.h"
+#include <ctype.h>
+
+/* Used as default value for git_buf->ptr so that people can always
+ * assume ptr is non-NULL and zero terminated even for new git_bufs.
+ */
+char git_buf__initbuf[1];
+
+char git_buf__oom[1];
+
+#define ENSURE_SIZE(b, d) \
+	if ((d) > (b)->asize && git_buf_grow((b), (d)) < 0)\
+		return -1;
+
+
+int git_buf_init(git_buf *buf, size_t initial_size)
+{
+	buf->asize = 0;
+	buf->size = 0;
+	buf->ptr = git_buf__initbuf;
+
+	ENSURE_SIZE(buf, initial_size);
+
+	return 0;
+}
+
+int git_buf_try_grow(
+	git_buf *buf, size_t target_size, bool mark_oom)
+{
+	char *new_ptr;
+	size_t new_size;
+
+	if (buf->ptr == git_buf__oom)
+		return -1;
+
+	if (buf->asize == 0 && buf->size != 0) {
+		giterr_set(GITERR_INVALID, "cannot grow a borrowed buffer");
+		return GIT_EINVALID;
+	}
+
+	if (!target_size)
+		target_size = buf->size;
+
+	if (target_size <= buf->asize)
+		return 0;
+
+	if (buf->asize == 0) {
+		new_size = target_size;
+		new_ptr = NULL;
+	} else {
+		new_size = buf->asize;
+		new_ptr = buf->ptr;
+	}
+
+	/* grow the buffer size by 1.5, until it's big enough
+	 * to fit our target size */
+	while (new_size < target_size)
+		new_size = (new_size << 1) - (new_size >> 1);
+
+	/* round allocation up to multiple of 8 */
+	new_size = (new_size + 7) & ~7;
+
+	if (new_size < buf->size) {
+		if (mark_oom)
+			buf->ptr = git_buf__oom;
+
+		giterr_set_oom();
+		return -1;
+	}
+
+	new_ptr = git__realloc(new_ptr, new_size);
+
+	if (!new_ptr) {
+		if (mark_oom) {
+			if (buf->ptr && (buf->ptr != git_buf__initbuf))
+				git__free(buf->ptr);
+			buf->ptr = git_buf__oom;
+		}
+		return -1;
+	}
+
+	buf->asize = new_size;
+	buf->ptr   = new_ptr;
+
+	/* truncate the existing buffer size if necessary */
+	if (buf->size >= buf->asize)
+		buf->size = buf->asize - 1;
+	buf->ptr[buf->size] = '\0';
+
+	return 0;
+}
+
+int git_buf_grow(git_buf *buffer, size_t target_size)
+{
+	return git_buf_try_grow(buffer, target_size, true);
+}
+
+int git_buf_grow_by(git_buf *buffer, size_t additional_size)
+{
+	size_t newsize;
+
+	if (GIT_ADD_SIZET_OVERFLOW(&newsize, buffer->size, additional_size)) {
+		buffer->ptr = git_buf__oom;
+		return -1;
+	}
+
+	return git_buf_try_grow(buffer, newsize, true);
+}
+
+void git_buf_free(git_buf *buf)
+{
+	if (!buf) return;
+
+	if (buf->asize > 0 && buf->ptr != NULL && buf->ptr != git_buf__oom)
+		git__free(buf->ptr);
+
+	git_buf_init(buf, 0);
+}
+
+void git_buf_sanitize(git_buf *buf)
+{
+	if (buf->ptr == NULL) {
+		assert(buf->size == 0 && buf->asize == 0);
+		buf->ptr = git_buf__initbuf;
+	} else if (buf->asize > buf->size)
+		buf->ptr[buf->size] = '\0';
+}
+
+void git_buf_clear(git_buf *buf)
+{
+	buf->size = 0;
+
+	if (!buf->ptr) {
+		buf->ptr = git_buf__initbuf;
+		buf->asize = 0;
+	}
+
+	if (buf->asize > 0)
+		buf->ptr[0] = '\0';
+}
+
+int git_buf_set(git_buf *buf, const void *data, size_t len)
+{
+	size_t alloclen;
+
+	if (len == 0 || data == NULL) {
+		git_buf_clear(buf);
+	} else {
+		if (data != buf->ptr) {
+			GITERR_CHECK_ALLOC_ADD(&alloclen, len, 1);
+			ENSURE_SIZE(buf, alloclen);
+			memmove(buf->ptr, data, len);
+		}
+
+		buf->size = len;
+		if (buf->asize > buf->size)
+			buf->ptr[buf->size] = '\0';
+
+	}
+	return 0;
+}
+
+int git_buf_is_binary(const git_buf *buf)
+{
+	return git_buf_text_is_binary(buf);
+}
+
+int git_buf_contains_nul(const git_buf *buf)
+{
+	return git_buf_text_contains_nul(buf);
+}
+
+int git_buf_sets(git_buf *buf, const char *string)
+{
+	return git_buf_set(buf, string, string ? strlen(string) : 0);
+}
+
+int git_buf_putc(git_buf *buf, char c)
+{
+	size_t new_size;
+	GITERR_CHECK_ALLOC_ADD(&new_size, buf->size, 2);
+	ENSURE_SIZE(buf, new_size);
+	buf->ptr[buf->size++] = c;
+	buf->ptr[buf->size] = '\0';
+	return 0;
+}
+
+int git_buf_putcn(git_buf *buf, char c, size_t len)
+{
+	size_t new_size;
+	GITERR_CHECK_ALLOC_ADD(&new_size, buf->size, len);
+	GITERR_CHECK_ALLOC_ADD(&new_size, new_size, 1);
+	ENSURE_SIZE(buf, new_size);
+	memset(buf->ptr + buf->size, c, len);
+	buf->size += len;
+	buf->ptr[buf->size] = '\0';
+	return 0;
+}
+
+int git_buf_put(git_buf *buf, const char *data, size_t len)
+{
+	if (len) {
+		size_t new_size;
+
+		assert(data);
+
+		GITERR_CHECK_ALLOC_ADD(&new_size, buf->size, len);
+		GITERR_CHECK_ALLOC_ADD(&new_size, new_size, 1);
+		ENSURE_SIZE(buf, new_size);
+		memmove(buf->ptr + buf->size, data, len);
+		buf->size += len;
+		buf->ptr[buf->size] = '\0';
+	}
+	return 0;
+}
+
+int git_buf_puts(git_buf *buf, const char *string)
+{
+	assert(string);
+	return git_buf_put(buf, string, strlen(string));
+}
+
+static const char base64_encode[] =
+	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+int git_buf_encode_base64(git_buf *buf, const char *data, size_t len)
+{
+	size_t extra = len % 3;
+	uint8_t *write, a, b, c;
+	const uint8_t *read = (const uint8_t *)data;
+	size_t blocks = (len / 3) + !!extra, alloclen;
+
+	GITERR_CHECK_ALLOC_ADD(&blocks, blocks, 1);
+	GITERR_CHECK_ALLOC_MULTIPLY(&alloclen, blocks, 4);
+	GITERR_CHECK_ALLOC_ADD(&alloclen, alloclen, buf->size);
+
+	ENSURE_SIZE(buf, alloclen);
+	write = (uint8_t *)&buf->ptr[buf->size];
+
+	/* convert each run of 3 bytes into 4 output bytes */
+	for (len -= extra; len > 0; len -= 3) {
+		a = *read++;
+		b = *read++;
+		c = *read++;
+
+		*write++ = base64_encode[a >> 2];
+		*write++ = base64_encode[(a & 0x03) << 4 | b >> 4];
+		*write++ = base64_encode[(b & 0x0f) << 2 | c >> 6];
+		*write++ = base64_encode[c & 0x3f];
+	}
+
+	if (extra > 0) {
+		a = *read++;
+		b = (extra > 1) ? *read++ : 0;
+
+		*write++ = base64_encode[a >> 2];
+		*write++ = base64_encode[(a & 0x03) << 4 | b >> 4];
+		*write++ = (extra > 1) ? base64_encode[(b & 0x0f) << 2] : '=';
+		*write++ = '=';
+	}
+
+	buf->size = ((char *)write) - buf->ptr;
+	buf->ptr[buf->size] = '\0';
+
+	return 0;
+}
+
+/* The inverse of base64_encode */
+static const int8_t base64_decode[] = {
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
+	52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1,  0, -1, -1,
+	-1,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
+	15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
+	-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+	41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
+};
+
+int git_buf_decode_base64(git_buf *buf, const char *base64, size_t len)
+{
+	size_t i;
+	int8_t a, b, c, d;
+	size_t orig_size = buf->size, new_size;
+
+	if (len % 4) {
+		giterr_set(GITERR_INVALID, "invalid base64 input");
+		return -1;
+	}
+
+	assert(len % 4 == 0);
+	GITERR_CHECK_ALLOC_ADD(&new_size, (len / 4 * 3), buf->size);
+	GITERR_CHECK_ALLOC_ADD(&new_size, new_size, 1);
+	ENSURE_SIZE(buf, new_size);
+
+	for (i = 0; i < len; i += 4) {
+		if ((a = base64_decode[(unsigned char)base64[i]]) < 0 ||
+			(b = base64_decode[(unsigned char)base64[i+1]]) < 0 ||
+			(c = base64_decode[(unsigned char)base64[i+2]]) < 0 ||
+			(d = base64_decode[(unsigned char)base64[i+3]]) < 0) {
+			buf->size = orig_size;
+			buf->ptr[buf->size] = '\0';
+
+			giterr_set(GITERR_INVALID, "invalid base64 input");
+			return -1;
+		}
+
+		buf->ptr[buf->size++] = ((a << 2) | (b & 0x30) >> 4);
+		buf->ptr[buf->size++] = ((b & 0x0f) << 4) | ((c & 0x3c) >> 2);
+		buf->ptr[buf->size++] = (c & 0x03) << 6 | (d & 0x3f);
+	}
+
+	buf->ptr[buf->size] = '\0';
+	return 0;
+}
+
+static const char base85_encode[] =
+	"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";
+
+int git_buf_encode_base85(git_buf *buf, const char *data, size_t len)
+{
+	size_t blocks = (len / 4) + !!(len % 4), alloclen;
+
+	GITERR_CHECK_ALLOC_MULTIPLY(&alloclen, blocks, 5);
+	GITERR_CHECK_ALLOC_ADD(&alloclen, alloclen, buf->size);
+	GITERR_CHECK_ALLOC_ADD(&alloclen, alloclen, 1);
+
+	ENSURE_SIZE(buf, alloclen);
+
+	while (len) {
+		uint32_t acc = 0;
+		char b85[5];
+		int i;
+
+		for (i = 24; i >= 0; i -= 8) {
+			uint8_t ch = *data++;
+			acc |= ch << i;
+
+			if (--len == 0)
+				break;
+		}
+
+		for (i = 4; i >= 0; i--) {
+			int val = acc % 85;
+			acc /= 85;
+
+			b85[i] = base85_encode[val];
+		}
+
+		for (i = 0; i < 5; i++)
+			buf->ptr[buf->size++] = b85[i];
+	}
+
+	buf->ptr[buf->size] = '\0';
+
+	return 0;
+}
+
+/* The inverse of base85_encode */
+static const int8_t base85_decode[] = {
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, 63, -1, 64, 65, 66, 67, -1, 68, 69, 70, 71, -1, 72, -1, -1,
+	 1,  2,  3,  4,  5,  6,  7,  8,  9, 10, -1, 73, 74, 75, 76, 77,
+	78, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,
+	26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, -1, -1, -1, 79, 80,
+	81, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,
+	52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 82, 83, 84, 85, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
+};
+
+int git_buf_decode_base85(
+	git_buf *buf,
+	const char *base85,
+	size_t base85_len,
+	size_t output_len)
+{
+	size_t orig_size = buf->size, new_size;
+
+	if (base85_len % 5 ||
+		output_len > base85_len * 4 / 5) {
+		giterr_set(GITERR_INVALID, "invalid base85 input");
+		return -1;
+	}
+
+	GITERR_CHECK_ALLOC_ADD(&new_size, output_len, buf->size);
+	GITERR_CHECK_ALLOC_ADD(&new_size, new_size, 1);
+	ENSURE_SIZE(buf, new_size);
+
+	while (output_len) {
+		unsigned acc = 0;
+		int de, cnt = 4;
+		unsigned char ch;
+		do {
+			ch = *base85++;
+			de = base85_decode[ch];
+			if (--de < 0)
+				goto on_error;
+
+			acc = acc * 85 + de;
+		} while (--cnt);
+		ch = *base85++;
+		de = base85_decode[ch];
+		if (--de < 0)
+			goto on_error;
+
+		/* Detect overflow. */
+		if (0xffffffff / 85 < acc ||
+			0xffffffff - de < (acc *= 85))
+			goto on_error;
+
+		acc += de;
+
+		cnt = (output_len < 4) ? output_len : 4;
+		output_len -= cnt;
+		do {
+			acc = (acc << 8) | (acc >> 24);
+			buf->ptr[buf->size++] = acc;
+		} while (--cnt);
+	}
+
+	buf->ptr[buf->size] = 0;
+
+	return 0;
+
+on_error:
+	buf->size = orig_size;
+	buf->ptr[buf->size] = '\0';
+
+	giterr_set(GITERR_INVALID, "invalid base85 input");
+	return -1;
+}
+
+#define HEX_DECODE(c) ((c | 32) % 39 - 9)
+
+int git_buf_decode_percent(
+	git_buf *buf,
+	const char *str,
+	size_t str_len)
+{
+	size_t str_pos, new_size;
+
+	GITERR_CHECK_ALLOC_ADD(&new_size, buf->size, str_len);
+	GITERR_CHECK_ALLOC_ADD(&new_size, new_size, 1);
+	ENSURE_SIZE(buf, new_size);
+
+	for (str_pos = 0; str_pos < str_len; buf->size++, str_pos++) {
+		if (str[str_pos] == '%' &&
+			str_len > str_pos + 2 &&
+			isxdigit(str[str_pos + 1]) &&
+			isxdigit(str[str_pos + 2])) {
+			buf->ptr[buf->size] = (HEX_DECODE(str[str_pos + 1]) << 4) +
+				HEX_DECODE(str[str_pos + 2]);
+			str_pos += 2;
+		} else {
+			buf->ptr[buf->size] = str[str_pos];
+		}
+	}
+
+	buf->ptr[buf->size] = '\0';
+	return 0;
+}
+
+int git_buf_vprintf(git_buf *buf, const char *format, va_list ap)
+{
+	size_t expected_size, new_size;
+	int len;
+
+	GITERR_CHECK_ALLOC_MULTIPLY(&expected_size, strlen(format), 2);
+	GITERR_CHECK_ALLOC_ADD(&expected_size, expected_size, buf->size);
+	ENSURE_SIZE(buf, expected_size);
+
+	while (1) {
+		va_list args;
+		va_copy(args, ap);
+
+		len = p_vsnprintf(
+			buf->ptr + buf->size,
+			buf->asize - buf->size,
+			format, args
+		);
+
+		va_end(args);
+
+		if (len < 0) {
+			git__free(buf->ptr);
+			buf->ptr = git_buf__oom;
+			return -1;
+		}
+
+		if ((size_t)len + 1 <= buf->asize - buf->size) {
+			buf->size += len;
+			break;
+		}
+
+		GITERR_CHECK_ALLOC_ADD(&new_size, buf->size, len);
+		GITERR_CHECK_ALLOC_ADD(&new_size, new_size, 1);
+		ENSURE_SIZE(buf, new_size);
+	}
+
+	return 0;
+}
+
+int git_buf_printf(git_buf *buf, const char *format, ...)
+{
+	int r;
+	va_list ap;
+
+	va_start(ap, format);
+	r = git_buf_vprintf(buf, format, ap);
+	va_end(ap);
+
+	return r;
+}
+
+void git_buf_copy_cstr(char *data, size_t datasize, const git_buf *buf)
+{
+	size_t copylen;
+
+	assert(data && datasize && buf);
+
+	data[0] = '\0';
+
+	if (buf->size == 0 || buf->asize <= 0)
+		return;
+
+	copylen = buf->size;
+	if (copylen > datasize - 1)
+		copylen = datasize - 1;
+	memmove(data, buf->ptr, copylen);
+	data[copylen] = '\0';
+}
+
+void git_buf_consume(git_buf *buf, const char *end)
+{
+	if (end > buf->ptr && end <= buf->ptr + buf->size) {
+		size_t consumed = end - buf->ptr;
+		memmove(buf->ptr, end, buf->size - consumed);
+		buf->size -= consumed;
+		buf->ptr[buf->size] = '\0';
+	}
+}
+
+void git_buf_truncate(git_buf *buf, size_t len)
+{
+	if (len >= buf->size)
+		return;
+
+	buf->size = len;
+	if (buf->size < buf->asize)
+		buf->ptr[buf->size] = '\0';
+}
+
+void git_buf_shorten(git_buf *buf, size_t amount)
+{
+	if (buf->size > amount)
+		git_buf_truncate(buf, buf->size - amount);
+	else
+		git_buf_clear(buf);
+}
+
+void git_buf_rtruncate_at_char(git_buf *buf, char separator)
+{
+	ssize_t idx = git_buf_rfind_next(buf, separator);
+	git_buf_truncate(buf, idx < 0 ? 0 : (size_t)idx);
+}
+
+void git_buf_swap(git_buf *buf_a, git_buf *buf_b)
+{
+	git_buf t = *buf_a;
+	*buf_a = *buf_b;
+	*buf_b = t;
+}
+
+char *git_buf_detach(git_buf *buf)
+{
+	char *data = buf->ptr;
+
+	if (buf->asize == 0 || buf->ptr == git_buf__oom)
+		return NULL;
+
+	git_buf_init(buf, 0);
+
+	return data;
+}
+
+int git_buf_attach(git_buf *buf, char *ptr, size_t asize)
+{
+	git_buf_free(buf);
+
+	if (ptr) {
+		buf->ptr = ptr;
+		buf->size = strlen(ptr);
+		if (asize)
+			buf->asize = (asize < buf->size) ? buf->size + 1 : asize;
+		else /* pass 0 to fall back on strlen + 1 */
+			buf->asize = buf->size + 1;
+	}
+
+	ENSURE_SIZE(buf, asize);
+	return 0;
+}
+
+void git_buf_attach_notowned(git_buf *buf, const char *ptr, size_t size)
+{
+	if (git_buf_is_allocated(buf))
+		git_buf_free(buf);
+
+	if (!size) {
+		git_buf_init(buf, 0);
+	} else {
+		buf->ptr = (char *)ptr;
+		buf->asize = 0;
+		buf->size = size;
+	}
+}
+
+int git_buf_join_n(git_buf *buf, char separator, int nbuf, ...)
+{
+	va_list ap;
+	int i;
+	size_t total_size = 0, original_size = buf->size;
+	char *out, *original = buf->ptr;
+
+	if (buf->size > 0 && buf->ptr[buf->size - 1] != separator)
+		++total_size; /* space for initial separator */
+
+	/* Make two passes to avoid multiple reallocation */
+
+	va_start(ap, nbuf);
+	for (i = 0; i < nbuf; ++i) {
+		const char* segment;
+		size_t segment_len;
+
+		segment = va_arg(ap, const char *);
+		if (!segment)
+			continue;
+
+		segment_len = strlen(segment);
+
+		GITERR_CHECK_ALLOC_ADD(&total_size, total_size, segment_len);
+
+		if (segment_len == 0 || segment[segment_len - 1] != separator)
+			GITERR_CHECK_ALLOC_ADD(&total_size, total_size, 1);
+	}
+	va_end(ap);
+
+	/* expand buffer if needed */
+	if (total_size == 0)
+		return 0;
+
+	GITERR_CHECK_ALLOC_ADD(&total_size, total_size, 1);
+	if (git_buf_grow_by(buf, total_size) < 0)
+		return -1;
+
+	out = buf->ptr + buf->size;
+
+	/* append separator to existing buf if needed */
+	if (buf->size > 0 && out[-1] != separator)
+		*out++ = separator;
+
+	va_start(ap, nbuf);
+	for (i = 0; i < nbuf; ++i) {
+		const char* segment;
+		size_t segment_len;
+
+		segment = va_arg(ap, const char *);
+		if (!segment)
+			continue;
+
+		/* deal with join that references buffer's original content */
+		if (segment >= original && segment < original + original_size) {
+			size_t offset = (segment - original);
+			segment = buf->ptr + offset;
+			segment_len = original_size - offset;
+		} else {
+			segment_len = strlen(segment);
+		}
+
+		/* skip leading separators */
+		if (out > buf->ptr && out[-1] == separator)
+			while (segment_len > 0 && *segment == separator) {
+				segment++;
+				segment_len--;
+			}
+
+		/* copy over next buffer */
+		if (segment_len > 0) {
+			memmove(out, segment, segment_len);
+			out += segment_len;
+		}
+
+		/* append trailing separator (except for last item) */
+		if (i < nbuf - 1 && out > buf->ptr && out[-1] != separator)
+			*out++ = separator;
+	}
+	va_end(ap);
+
+	/* set size based on num characters actually written */
+	buf->size = out - buf->ptr;
+	buf->ptr[buf->size] = '\0';
+
+	return 0;
+}
+
+int git_buf_join(
+	git_buf *buf,
+	char separator,
+	const char *str_a,
+	const char *str_b)
+{
+	size_t strlen_a = str_a ? strlen(str_a) : 0;
+	size_t strlen_b = strlen(str_b);
+	size_t alloc_len;
+	int need_sep = 0;
+	ssize_t offset_a = -1;
+
+	/* not safe to have str_b point internally to the buffer */
+	assert(str_b < buf->ptr || str_b >= buf->ptr + buf->size);
+
+	/* figure out if we need to insert a separator */
+	if (separator && strlen_a) {
+		while (*str_b == separator) { str_b++; strlen_b--; }
+		if (str_a[strlen_a - 1] != separator)
+			need_sep = 1;
+	}
+
+	/* str_a could be part of the buffer */
+	if (str_a >= buf->ptr && str_a < buf->ptr + buf->size)
+		offset_a = str_a - buf->ptr;
+
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, strlen_a, strlen_b);
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, need_sep);
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, 1);
+	ENSURE_SIZE(buf, alloc_len);
+
+	/* fix up internal pointers */
+	if (offset_a >= 0)
+		str_a = buf->ptr + offset_a;
+
+	/* do the actual copying */
+	if (offset_a != 0 && str_a)
+		memmove(buf->ptr, str_a, strlen_a);
+	if (need_sep)
+		buf->ptr[strlen_a] = separator;
+	memcpy(buf->ptr + strlen_a + need_sep, str_b, strlen_b);
+
+	buf->size = strlen_a + strlen_b + need_sep;
+	buf->ptr[buf->size] = '\0';
+
+	return 0;
+}
+
+int git_buf_join3(
+	git_buf *buf,
+	char separator,
+	const char *str_a,
+	const char *str_b,
+	const char *str_c)
+{
+	size_t len_a = strlen(str_a),
+		len_b = strlen(str_b),
+		len_c = strlen(str_c),
+		len_total;
+	int sep_a = 0, sep_b = 0;
+	char *tgt;
+
+	/* for this function, disallow pointers into the existing buffer */
+	assert(str_a < buf->ptr || str_a >= buf->ptr + buf->size);
+	assert(str_b < buf->ptr || str_b >= buf->ptr + buf->size);
+	assert(str_c < buf->ptr || str_c >= buf->ptr + buf->size);
+
+	if (separator) {
+		if (len_a > 0) {
+			while (*str_b == separator) { str_b++; len_b--; }
+			sep_a = (str_a[len_a - 1] != separator);
+		}
+		if (len_a > 0 || len_b > 0)
+			while (*str_c == separator) { str_c++; len_c--; }
+		if (len_b > 0)
+			sep_b = (str_b[len_b - 1] != separator);
+	}
+
+	GITERR_CHECK_ALLOC_ADD(&len_total, len_a, sep_a);
+	GITERR_CHECK_ALLOC_ADD(&len_total, len_total, len_b);
+	GITERR_CHECK_ALLOC_ADD(&len_total, len_total, sep_b);
+	GITERR_CHECK_ALLOC_ADD(&len_total, len_total, len_c);
+	GITERR_CHECK_ALLOC_ADD(&len_total, len_total, 1);
+	ENSURE_SIZE(buf, len_total);
+
+	tgt = buf->ptr;
+
+	if (len_a) {
+		memcpy(tgt, str_a, len_a);
+		tgt += len_a;
+	}
+	if (sep_a)
+		*tgt++ = separator;
+	if (len_b) {
+		memcpy(tgt, str_b, len_b);
+		tgt += len_b;
+	}
+	if (sep_b)
+		*tgt++ = separator;
+	if (len_c)
+		memcpy(tgt, str_c, len_c);
+
+	buf->size = len_a + sep_a + len_b + sep_b + len_c;
+	buf->ptr[buf->size] = '\0';
+
+	return 0;
+}
+
+void git_buf_rtrim(git_buf *buf)
+{
+	while (buf->size > 0) {
+		if (!git__isspace(buf->ptr[buf->size - 1]))
+			break;
+
+		buf->size--;
+	}
+
+	if (buf->asize > buf->size)
+		buf->ptr[buf->size] = '\0';
+}
+
+int git_buf_cmp(const git_buf *a, const git_buf *b)
+{
+	int result = memcmp(a->ptr, b->ptr, min(a->size, b->size));
+	return (result != 0) ? result :
+		(a->size < b->size) ? -1 : (a->size > b->size) ? 1 : 0;
+}
+
+int git_buf_splice(
+	git_buf *buf,
+	size_t where,
+	size_t nb_to_remove,
+	const char *data,
+	size_t nb_to_insert)
+{
+	char *splice_loc;
+	size_t new_size, alloc_size;
+
+	assert(buf && where <= buf->size && nb_to_remove <= buf->size - where);
+
+	splice_loc = buf->ptr + where;
+
+	/* Ported from git.git
+	 * https://github.com/git/git/blob/16eed7c/strbuf.c#L159-176
+	 */
+	GITERR_CHECK_ALLOC_ADD(&new_size, (buf->size - nb_to_remove), nb_to_insert);
+	GITERR_CHECK_ALLOC_ADD(&alloc_size, new_size, 1);
+	ENSURE_SIZE(buf, alloc_size);
+
+	memmove(splice_loc + nb_to_insert,
+		splice_loc + nb_to_remove,
+		buf->size - where - nb_to_remove);
+
+	memcpy(splice_loc, data, nb_to_insert);
+
+	buf->size = new_size;
+	buf->ptr[buf->size] = '\0';
+	return 0;
+}
+
+/* Quote per http://marc.info/?l=git&m=112927316408690&w=2 */
+int git_buf_quote(git_buf *buf)
+{
+	const char whitespace[] = { 'a', 'b', 't', 'n', 'v', 'f', 'r' };
+	git_buf quoted = GIT_BUF_INIT;
+	size_t i = 0;
+	bool quote = false;
+	int error = 0;
+
+	/* walk to the first char that needs quoting */
+	if (buf->size && buf->ptr[0] == '!')
+		quote = true;
+
+	for (i = 0; !quote && i < buf->size; i++) {
+		if (buf->ptr[i] == '"' || buf->ptr[i] == '\\' ||
+			buf->ptr[i] < ' ' || buf->ptr[i] > '~') {
+			quote = true;
+			break;
+		}
+	}
+
+	if (!quote)
+		goto done;
+
+	git_buf_putc(&quoted, '"');
+	git_buf_put(&quoted, buf->ptr, i);
+
+	for (; i < buf->size; i++) {
+		/* whitespace - use the map above, which is ordered by ascii value */
+		if (buf->ptr[i] >= '\a' && buf->ptr[i] <= '\r') {
+			git_buf_putc(&quoted, '\\');
+			git_buf_putc(&quoted, whitespace[buf->ptr[i] - '\a']);
+		}
+
+		/* double quote and backslash must be escaped */
+		else if (buf->ptr[i] == '"' || buf->ptr[i] == '\\') {
+			git_buf_putc(&quoted, '\\');
+			git_buf_putc(&quoted, buf->ptr[i]);
+		}
+
+		/* escape anything unprintable as octal */
+		else if (buf->ptr[i] != ' ' &&
+				(buf->ptr[i] < '!' || buf->ptr[i] > '~')) {
+			git_buf_printf(&quoted, "\\%03o", (unsigned char)buf->ptr[i]);
+		}
+
+		/* yay, printable! */
+		else {
+			git_buf_putc(&quoted, buf->ptr[i]);
+		}
+	}
+
+	git_buf_putc(&quoted, '"');
+
+	if (git_buf_oom(&quoted)) {
+		error = -1;
+		goto done;
+	}
+
+	git_buf_swap(&quoted, buf);
+
+done:
+	git_buf_free(&quoted);
+	return error;
+}
+
+/* Unquote per http://marc.info/?l=git&m=112927316408690&w=2 */
+int git_buf_unquote(git_buf *buf)
+{
+	size_t i, j;
+	char ch;
+
+	git_buf_rtrim(buf);
+
+	if (buf->size < 2 || buf->ptr[0] != '"' || buf->ptr[buf->size-1] != '"')
+		goto invalid;
+
+	for (i = 0, j = 1; j < buf->size-1; i++, j++) {
+		ch = buf->ptr[j];
+
+		if (ch == '\\') {
+			if (j == buf->size-2)
+				goto invalid;
+
+			ch = buf->ptr[++j];
+
+			switch (ch) {
+			/* \" or \\ simply copy the char in */
+			case '"': case '\\':
+				break;
+
+			/* add the appropriate escaped char */
+			case 'a': ch = '\a'; break;
+			case 'b': ch = '\b'; break;
+			case 'f': ch = '\f'; break;
+			case 'n': ch = '\n'; break;
+			case 'r': ch = '\r'; break;
+			case 't': ch = '\t'; break;
+			case 'v': ch = '\v'; break;
+
+			/* \xyz digits convert to the char*/
+			case '0': case '1': case '2': case '3':
+				if (j == buf->size-3) {
+					giterr_set(GITERR_INVALID,
+						"truncated quoted character \\%c", ch);
+					return -1;
+				}
+
+				if (buf->ptr[j+1] < '0' || buf->ptr[j+1] > '7' ||
+					buf->ptr[j+2] < '0' || buf->ptr[j+2] > '7') {
+					giterr_set(GITERR_INVALID,
+						"truncated quoted character \\%c%c%c",
+						buf->ptr[j], buf->ptr[j+1], buf->ptr[j+2]);
+					return -1;
+				}
+
+				ch = ((buf->ptr[j] - '0') << 6) |
+					((buf->ptr[j+1] - '0') << 3) |
+					(buf->ptr[j+2] - '0');
+				j += 2;
+				break;
+
+			default:
+				giterr_set(GITERR_INVALID, "invalid quoted character \\%c", ch);
+				return -1;
+			}
+		}
+
+		buf->ptr[i] = ch;
+	}
+
+	buf->ptr[i] = '\0';
+	buf->size = i;
+
+	return 0;
+
+invalid:
+	giterr_set(GITERR_INVALID, "invalid quoted line");
+	return -1;
+}

vendor/libgit2-sys/libgit2/src/buffer.h

diff --git a/vendor/libgit2-sys/libgit2/src/buffer.h b/vendor/libgit2-sys/libgit2/src/buffer.h
new file mode 100644
index 0000000..cc77fc0
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/buffer.h
@@ -0,0 +1,221 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_buffer_h__
+#define INCLUDE_buffer_h__
+
+#include "common.h"
+#include "git2/strarray.h"
+#include "git2/buffer.h"
+
+/* typedef struct {
+ *  	char   *ptr;
+ *  	size_t asize, size;
+ * } git_buf;
+ */
+
+extern char git_buf__initbuf[];
+extern char git_buf__oom[];
+
+/* Use to initialize buffer structure when git_buf is on stack */
+#define GIT_BUF_INIT { git_buf__initbuf, 0, 0 }
+
+GIT_INLINE(bool) git_buf_is_allocated(const git_buf *buf)
+{
+	return (buf->ptr != NULL && buf->asize > 0);
+}
+
+/**
+ * Initialize a git_buf structure.
+ *
+ * For the cases where GIT_BUF_INIT cannot be used to do static
+ * initialization.
+ */
+extern int git_buf_init(git_buf *buf, size_t initial_size);
+
+/**
+ * Resize the buffer allocation to make more space.
+ *
+ * This will attempt to grow the buffer to accommodate the additional size.
+ * It is similar to `git_buf_grow`, but performs the new size calculation,
+ * checking for overflow.
+ *
+ * Like `git_buf_grow`, if this is a user-supplied buffer, this will allocate
+ * a new buffer.
+ */
+extern int git_buf_grow_by(git_buf *buffer, size_t additional_size);
+
+/**
+ * Attempt to grow the buffer to hold at least `target_size` bytes.
+ *
+ * If the allocation fails, this will return an error.  If `mark_oom` is true,
+ * this will mark the buffer as invalid for future operations; if false,
+ * existing buffer content will be preserved, but calling code must handle
+ * that buffer was not expanded.  If `preserve_external` is true, then any
+ * existing data pointed to be `ptr` even if `asize` is zero will be copied
+ * into the newly allocated buffer.
+ */
+extern int git_buf_try_grow(
+	git_buf *buf, size_t target_size, bool mark_oom);
+
+/**
+ * Sanitizes git_buf structures provided from user input.  Users of the
+ * library, when providing git_buf's, may wish to provide a NULL ptr for
+ * ease of handling.  The buffer routines, however, expect a non-NULL ptr
+ * always.  This helper method simply handles NULL input, converting to a
+ * git_buf__initbuf. If a buffer with a non-NULL ptr is passed in, this method
+ * assures that the buffer is '\0'-terminated.
+ */
+extern void git_buf_sanitize(git_buf *buf);
+
+extern void git_buf_swap(git_buf *buf_a, git_buf *buf_b);
+extern char *git_buf_detach(git_buf *buf);
+extern int git_buf_attach(git_buf *buf, char *ptr, size_t asize);
+
+/* Populates a `git_buf` where the contents are not "owned" by the
+ * buffer, and calls to `git_buf_free` will not free the given buf.
+ */
+extern void git_buf_attach_notowned(
+	git_buf *buf, const char *ptr, size_t size);
+
+/**
+ * Test if there have been any reallocation failures with this git_buf.
+ *
+ * Any function that writes to a git_buf can fail due to memory allocation
+ * issues.  If one fails, the git_buf will be marked with an OOM error and
+ * further calls to modify the buffer will fail.  Check git_buf_oom() at the
+ * end of your sequence and it will be true if you ran out of memory at any
+ * point with that buffer.
+ *
+ * @return false if no error, true if allocation error
+ */
+GIT_INLINE(bool) git_buf_oom(const git_buf *buf)
+{
+	return (buf->ptr == git_buf__oom);
+}
+
+/*
+ * Functions below that return int value error codes will return 0 on
+ * success or -1 on failure (which generally means an allocation failed).
+ * Using a git_buf where the allocation has failed with result in -1 from
+ * all further calls using that buffer.  As a result, you can ignore the
+ * return code of these functions and call them in a series then just call
+ * git_buf_oom at the end.
+ */
+int git_buf_sets(git_buf *buf, const char *string);
+int git_buf_putc(git_buf *buf, char c);
+int git_buf_putcn(git_buf *buf, char c, size_t len);
+int git_buf_put(git_buf *buf, const char *data, size_t len);
+int git_buf_puts(git_buf *buf, const char *string);
+int git_buf_printf(git_buf *buf, const char *format, ...) GIT_FORMAT_PRINTF(2, 3);
+int git_buf_vprintf(git_buf *buf, const char *format, va_list ap);
+void git_buf_clear(git_buf *buf);
+void git_buf_consume(git_buf *buf, const char *end);
+void git_buf_truncate(git_buf *buf, size_t len);
+void git_buf_shorten(git_buf *buf, size_t amount);
+void git_buf_rtruncate_at_char(git_buf *path, char separator);
+
+/** General join with separator */
+int git_buf_join_n(git_buf *buf, char separator, int nbuf, ...);
+/** Fast join of two strings - first may legally point into `buf` data */
+int git_buf_join(git_buf *buf, char separator, const char *str_a, const char *str_b);
+/** Fast join of three strings - cannot reference `buf` data */
+int git_buf_join3(git_buf *buf, char separator, const char *str_a, const char *str_b, const char *str_c);
+
+/**
+ * Join two strings as paths, inserting a slash between as needed.
+ * @return 0 on success, -1 on failure
+ */
+GIT_INLINE(int) git_buf_joinpath(git_buf *buf, const char *a, const char *b)
+{
+	return git_buf_join(buf, '/', a, b);
+}
+
+GIT_INLINE(const char *) git_buf_cstr(const git_buf *buf)
+{
+	return buf->ptr;
+}
+
+GIT_INLINE(size_t) git_buf_len(const git_buf *buf)
+{
+	return buf->size;
+}
+
+void git_buf_copy_cstr(char *data, size_t datasize, const git_buf *buf);
+
+#define git_buf_PUTS(buf, str) git_buf_put(buf, str, sizeof(str) - 1)
+
+GIT_INLINE(ssize_t) git_buf_rfind_next(const git_buf *buf, char ch)
+{
+	ssize_t idx = (ssize_t)buf->size - 1;
+	while (idx >= 0 && buf->ptr[idx] == ch) idx--;
+	while (idx >= 0 && buf->ptr[idx] != ch) idx--;
+	return idx;
+}
+
+GIT_INLINE(ssize_t) git_buf_rfind(const git_buf *buf, char ch)
+{
+	ssize_t idx = (ssize_t)buf->size - 1;
+	while (idx >= 0 && buf->ptr[idx] != ch) idx--;
+	return idx;
+}
+
+GIT_INLINE(ssize_t) git_buf_find(const git_buf *buf, char ch)
+{
+	void *found = memchr(buf->ptr, ch, buf->size);
+	return found ? (ssize_t)((const char *)found - buf->ptr) : -1;
+}
+
+/* Remove whitespace from the end of the buffer */
+void git_buf_rtrim(git_buf *buf);
+
+int git_buf_cmp(const git_buf *a, const git_buf *b);
+
+/* Quote and unquote a buffer as specified in
+ * http://marc.info/?l=git&m=112927316408690&w=2
+ */
+int git_buf_quote(git_buf *buf);
+int git_buf_unquote(git_buf *buf);
+
+/* Write data as base64 encoded in buffer */
+int git_buf_encode_base64(git_buf *buf, const char *data, size_t len);
+/* Decode the given bas64 and write the result to the buffer */
+int git_buf_decode_base64(git_buf *buf, const char *base64, size_t len);
+
+/* Write data as "base85" encoded in buffer */
+int git_buf_encode_base85(git_buf *buf, const char *data, size_t len);
+/* Decode the given "base85" and write the result to the buffer */
+int git_buf_decode_base85(git_buf *buf, const char *base64, size_t len, size_t output_len);
+
+/* Decode the given percent-encoded string and write the result to the buffer */
+int git_buf_decode_percent(git_buf *buf, const char *str, size_t len);
+
+/*
+ * Insert, remove or replace a portion of the buffer.
+ *
+ * @param buf The buffer to work with
+ *
+ * @param where The location in the buffer where the transformation
+ * should be applied.
+ *
+ * @param nb_to_remove The number of chars to be removed. 0 to not
+ * remove any character in the buffer.
+ *
+ * @param data A pointer to the data which should be inserted.
+ *
+ * @param nb_to_insert The number of chars to be inserted. 0 to not
+ * insert any character from the buffer.
+ *
+ * @return 0 or an error code.
+ */
+int git_buf_splice(
+	git_buf *buf,
+	size_t where,
+	size_t nb_to_remove,
+	const char *data,
+	size_t nb_to_insert);
+
+#endif

vendor/libgit2-sys/libgit2/src/cache.c

diff --git a/vendor/libgit2-sys/libgit2/src/cache.c b/vendor/libgit2-sys/libgit2/src/cache.c
new file mode 100644
index 0000000..cdd1297
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/cache.c
@@ -0,0 +1,277 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "cache.h"
+
+#include "repository.h"
+#include "commit.h"
+#include "thread-utils.h"
+#include "util.h"
+#include "odb.h"
+#include "object.h"
+#include "git2/oid.h"
+
+bool git_cache__enabled = true;
+ssize_t git_cache__max_storage = (256 * 1024 * 1024);
+git_atomic_ssize git_cache__current_storage = {0};
+
+static size_t git_cache__max_object_size[8] = {
+	0,     /* GIT_OBJ__EXT1 */
+	4096,  /* GIT_OBJ_COMMIT */
+	4096,  /* GIT_OBJ_TREE */
+	0,     /* GIT_OBJ_BLOB */
+	4096,  /* GIT_OBJ_TAG */
+	0,     /* GIT_OBJ__EXT2 */
+	0,     /* GIT_OBJ_OFS_DELTA */
+	0      /* GIT_OBJ_REF_DELTA */
+};
+
+int git_cache_set_max_object_size(git_otype type, size_t size)
+{
+	if (type < 0 || (size_t)type >= ARRAY_SIZE(git_cache__max_object_size)) {
+		giterr_set(GITERR_INVALID, "type out of range");
+		return -1;
+	}
+
+	git_cache__max_object_size[type] = size;
+	return 0;
+}
+
+void git_cache_dump_stats(git_cache *cache)
+{
+	git_cached_obj *object;
+
+	if (git_cache_size(cache) == 0)
+		return;
+
+	printf("Cache %p: %"PRIuZ" items cached, %"PRIdZ" bytes\n",
+		cache, git_cache_size(cache), cache->used_memory);
+
+	git_oidmap_foreach_value(cache->map, object, {
+		char oid_str[9];
+		printf(" %s%c %s (%"PRIuZ")\n",
+			git_object_type2string(object->type),
+			object->flags == GIT_CACHE_STORE_PARSED ? '*' : ' ',
+			git_oid_tostr(oid_str, sizeof(oid_str), &object->oid),
+			object->size
+		);
+	});
+}
+
+int git_cache_init(git_cache *cache)
+{
+	memset(cache, 0, sizeof(*cache));
+	cache->map = git_oidmap_alloc();
+	GITERR_CHECK_ALLOC(cache->map);
+	if (git_rwlock_init(&cache->lock)) {
+		giterr_set(GITERR_OS, "failed to initialize cache rwlock");
+		return -1;
+	}
+	return 0;
+}
+
+/* called with lock */
+static void clear_cache(git_cache *cache)
+{
+	git_cached_obj *evict = NULL;
+
+	if (git_cache_size(cache) == 0)
+		return;
+
+	git_oidmap_foreach_value(cache->map, evict, {
+		git_cached_obj_decref(evict);
+	});
+
+	git_oidmap_clear(cache->map);
+	git_atomic_ssize_add(&git_cache__current_storage, -cache->used_memory);
+	cache->used_memory = 0;
+}
+
+void git_cache_clear(git_cache *cache)
+{
+	if (git_rwlock_wrlock(&cache->lock) < 0)
+		return;
+
+	clear_cache(cache);
+
+	git_rwlock_wrunlock(&cache->lock);
+}
+
+void git_cache_free(git_cache *cache)
+{
+	git_cache_clear(cache);
+	git_oidmap_free(cache->map);
+	git_rwlock_free(&cache->lock);
+	git__memzero(cache, sizeof(*cache));
+}
+
+/* Called with lock */
+static void cache_evict_entries(git_cache *cache)
+{
+	uint32_t seed = rand();
+	size_t evict_count = 8;
+	ssize_t evicted_memory = 0;
+
+	/* do not infinite loop if there's not enough entries to evict  */
+	if (evict_count > git_cache_size(cache)) {
+		clear_cache(cache);
+		return;
+	}
+
+	while (evict_count > 0) {
+		khiter_t pos = seed++ % git_oidmap_end(cache->map);
+
+		if (git_oidmap_has_data(cache->map, pos)) {
+			git_cached_obj *evict = git_oidmap_value_at(cache->map, pos);
+
+			evict_count--;
+			evicted_memory += evict->size;
+			git_cached_obj_decref(evict);
+
+			git_oidmap_delete_at(cache->map, pos);
+		}
+	}
+
+	cache->used_memory -= evicted_memory;
+	git_atomic_ssize_add(&git_cache__current_storage, -evicted_memory);
+}
+
+static bool cache_should_store(git_otype object_type, size_t object_size)
+{
+	size_t max_size = git_cache__max_object_size[object_type];
+	return git_cache__enabled && object_size < max_size;
+}
+
+static void *cache_get(git_cache *cache, const git_oid *oid, unsigned int flags)
+{
+	khiter_t pos;
+	git_cached_obj *entry = NULL;
+
+	if (!git_cache__enabled || git_rwlock_rdlock(&cache->lock) < 0)
+		return NULL;
+
+	pos = git_oidmap_lookup_index(cache->map, oid);
+	if (git_oidmap_valid_index(cache->map, pos)) {
+		entry = git_oidmap_value_at(cache->map, pos);
+
+		if (flags && entry->flags != flags) {
+			entry = NULL;
+		} else {
+			git_cached_obj_incref(entry);
+		}
+	}
+
+	git_rwlock_rdunlock(&cache->lock);
+
+	return entry;
+}
+
+static void *cache_store(git_cache *cache, git_cached_obj *entry)
+{
+	khiter_t pos;
+
+	git_cached_obj_incref(entry);
+
+	if (!git_cache__enabled && cache->used_memory > 0) {
+		git_cache_clear(cache);
+		return entry;
+	}
+
+	if (!cache_should_store(entry->type, entry->size))
+		return entry;
+
+	if (git_rwlock_wrlock(&cache->lock) < 0)
+		return entry;
+
+	/* soften the load on the cache */
+	if (git_cache__current_storage.val > git_cache__max_storage)
+		cache_evict_entries(cache);
+
+	pos = git_oidmap_lookup_index(cache->map, &entry->oid);
+
+	/* not found */
+	if (!git_oidmap_valid_index(cache->map, pos)) {
+		int rval;
+
+		git_oidmap_insert(cache->map, &entry->oid, entry, &rval);
+		if (rval >= 0) {
+			git_cached_obj_incref(entry);
+			cache->used_memory += entry->size;
+			git_atomic_ssize_add(&git_cache__current_storage, (ssize_t)entry->size);
+		}
+	}
+	/* found */
+	else {
+		git_cached_obj *stored_entry = git_oidmap_value_at(cache->map, pos);
+
+		if (stored_entry->flags == entry->flags) {
+			git_cached_obj_decref(entry);
+			git_cached_obj_incref(stored_entry);
+			entry = stored_entry;
+		} else if (stored_entry->flags == GIT_CACHE_STORE_RAW &&
+			entry->flags == GIT_CACHE_STORE_PARSED) {
+			git_cached_obj_decref(stored_entry);
+			git_cached_obj_incref(entry);
+
+			git_oidmap_set_key_at(cache->map, pos, &entry->oid);
+			git_oidmap_set_value_at(cache->map, pos, entry);
+		} else {
+			/* NO OP */
+		}
+	}
+
+	git_rwlock_wrunlock(&cache->lock);
+	return entry;
+}
+
+void *git_cache_store_raw(git_cache *cache, git_odb_object *entry)
+{
+	entry->cached.flags = GIT_CACHE_STORE_RAW;
+	return cache_store(cache, (git_cached_obj *)entry);
+}
+
+void *git_cache_store_parsed(git_cache *cache, git_object *entry)
+{
+	entry->cached.flags = GIT_CACHE_STORE_PARSED;
+	return cache_store(cache, (git_cached_obj *)entry);
+}
+
+git_odb_object *git_cache_get_raw(git_cache *cache, const git_oid *oid)
+{
+	return cache_get(cache, oid, GIT_CACHE_STORE_RAW);
+}
+
+git_object *git_cache_get_parsed(git_cache *cache, const git_oid *oid)
+{
+	return cache_get(cache, oid, GIT_CACHE_STORE_PARSED);
+}
+
+void *git_cache_get_any(git_cache *cache, const git_oid *oid)
+{
+	return cache_get(cache, oid, GIT_CACHE_STORE_ANY);
+}
+
+void git_cached_obj_decref(void *_obj)
+{
+	git_cached_obj *obj = _obj;
+
+	if (git_atomic_dec(&obj->refcount) == 0) {
+		switch (obj->flags) {
+		case GIT_CACHE_STORE_RAW:
+			git_odb_object__free(_obj);
+			break;
+
+		case GIT_CACHE_STORE_PARSED:
+			git_object__free(_obj);
+			break;
+
+		default:
+			git__free(_obj);
+			break;
+		}
+	}
+}

vendor/libgit2-sys/libgit2/src/cache.h

diff --git a/vendor/libgit2-sys/libgit2/src/cache.h b/vendor/libgit2-sys/libgit2/src/cache.h
new file mode 100644
index 0000000..9c09954
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/cache.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_cache_h__
+#define INCLUDE_cache_h__
+
+#include "common.h"
+
+#include "git2/common.h"
+#include "git2/oid.h"
+#include "git2/odb.h"
+
+#include "thread-utils.h"
+#include "oidmap.h"
+
+enum {
+	GIT_CACHE_STORE_ANY = 0,
+	GIT_CACHE_STORE_RAW = 1,
+	GIT_CACHE_STORE_PARSED = 2
+};
+
+typedef struct {
+	git_oid    oid;
+	int16_t    type;  /* git_otype value */
+	uint16_t   flags; /* GIT_CACHE_STORE value */
+	size_t     size;
+	git_atomic refcount;
+} git_cached_obj;
+
+typedef struct {
+	git_oidmap *map;
+	git_rwlock  lock;
+	ssize_t     used_memory;
+} git_cache;
+
+extern bool git_cache__enabled;
+extern ssize_t git_cache__max_storage;
+extern git_atomic_ssize git_cache__current_storage;
+
+int git_cache_set_max_object_size(git_otype type, size_t size);
+
+int git_cache_init(git_cache *cache);
+void git_cache_free(git_cache *cache);
+void git_cache_clear(git_cache *cache);
+
+void *git_cache_store_raw(git_cache *cache, git_odb_object *entry);
+void *git_cache_store_parsed(git_cache *cache, git_object *entry);
+
+git_odb_object *git_cache_get_raw(git_cache *cache, const git_oid *oid);
+git_object *git_cache_get_parsed(git_cache *cache, const git_oid *oid);
+void *git_cache_get_any(git_cache *cache, const git_oid *oid);
+
+GIT_INLINE(size_t) git_cache_size(git_cache *cache)
+{
+	return (size_t)git_oidmap_size(cache->map);
+}
+
+GIT_INLINE(void) git_cached_obj_incref(void *_obj)
+{
+	git_cached_obj *obj = _obj;
+	git_atomic_inc(&obj->refcount);
+}
+
+void git_cached_obj_decref(void *_obj);
+
+#endif

vendor/libgit2-sys/libgit2/src/cc-compat.h

diff --git a/vendor/libgit2-sys/libgit2/src/cc-compat.h b/vendor/libgit2-sys/libgit2/src/cc-compat.h
new file mode 100644
index 0000000..0f05cd2
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/cc-compat.h
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_cc_compat_h__
+#define INCLUDE_cc_compat_h__
+
+#include <stdarg.h>
+
+/*
+ * See if our compiler is known to support flexible array members.
+ */
+#ifndef GIT_FLEX_ARRAY
+#	if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
+#		define GIT_FLEX_ARRAY /* empty */
+#	elif defined(__GNUC__)
+#		if (__GNUC__ >= 3)
+#			define GIT_FLEX_ARRAY /* empty */
+#		else
+#			define GIT_FLEX_ARRAY 0 /* older GNU extension */
+#		endif
+#	endif
+
+/* Default to safer but a bit wasteful traditional style */
+#	ifndef GIT_FLEX_ARRAY
+#		define GIT_FLEX_ARRAY 1
+#	endif
+#endif
+
+#ifdef __GNUC__
+#	define GIT_TYPEOF(x) (__typeof__(x))
+#else
+#	define GIT_TYPEOF(x)
+#endif
+
+#if defined(__GNUC__)
+#	define GIT_ALIGN(x,size) x __attribute__ ((aligned(size)))
+#elif defined(_MSC_VER)
+#	define GIT_ALIGN(x,size) __declspec(align(size)) x
+#else
+#	define GIT_ALIGN(x,size) x
+#endif
+
+#define GIT_UNUSED(x) ((void)(x))
+
+/* Define the printf format specifer to use for size_t output */
+#if defined(_MSC_VER) || defined(__MINGW32__)
+#	define PRIuZ "Iu"
+#	define PRIxZ "Ix"
+#	define PRIdZ "Id"
+#else
+#	define PRIuZ "zu"
+#	define PRIxZ "zx"
+#	define PRIdZ "zd"
+#endif
+
+/* Micosoft Visual C/C++ */
+#if defined(_MSC_VER)
+/* disable "deprecated function" warnings */
+#	pragma warning ( disable : 4996 )
+/* disable "conditional expression is constant" level 4 warnings */
+#	pragma warning ( disable : 4127 )
+#endif
+
+#if defined (_MSC_VER)
+	typedef unsigned char bool;
+#	ifndef true
+#		define true 1
+#	endif
+#	ifndef false
+#		define false 0
+#	endif
+#else
+#	include <stdbool.h>
+#endif
+
+#ifndef va_copy
+#	ifdef __va_copy
+#		define va_copy(dst, src) __va_copy(dst, src)
+#	else
+#		define va_copy(dst, src) ((dst) = (src))
+#	endif
+#endif
+
+#endif

vendor/libgit2-sys/libgit2/src/checkout.c

diff --git a/vendor/libgit2-sys/libgit2/src/checkout.c b/vendor/libgit2-sys/libgit2/src/checkout.c
new file mode 100644
index 0000000..debdbe9
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/checkout.c
@@ -0,0 +1,2790 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "checkout.h"
+
+#include <assert.h>
+
+#include "git2/repository.h"
+#include "git2/refs.h"
+#include "git2/tree.h"
+#include "git2/blob.h"
+#include "git2/config.h"
+#include "git2/diff.h"
+#include "git2/submodule.h"
+#include "git2/sys/index.h"
+#include "git2/sys/filter.h"
+#include "git2/merge.h"
+
+#include "refs.h"
+#include "repository.h"
+#include "index.h"
+#include "filter.h"
+#include "blob.h"
+#include "diff.h"
+#include "diff_generate.h"
+#include "pathspec.h"
+#include "buf_text.h"
+#include "diff_xdiff.h"
+#include "path.h"
+#include "attr.h"
+#include "pool.h"
+#include "strmap.h"
+
+/* See docs/checkout-internals.md for more information */
+
+enum {
+	CHECKOUT_ACTION__NONE = 0,
+	CHECKOUT_ACTION__REMOVE = 1,
+	CHECKOUT_ACTION__UPDATE_BLOB = 2,
+	CHECKOUT_ACTION__UPDATE_SUBMODULE = 4,
+	CHECKOUT_ACTION__CONFLICT = 8,
+	CHECKOUT_ACTION__REMOVE_CONFLICT = 16,
+	CHECKOUT_ACTION__UPDATE_CONFLICT = 32,
+	CHECKOUT_ACTION__MAX = 32,
+	CHECKOUT_ACTION__DEFER_REMOVE = 64,
+	CHECKOUT_ACTION__REMOVE_AND_UPDATE =
+		(CHECKOUT_ACTION__UPDATE_BLOB | CHECKOUT_ACTION__REMOVE),
+};
+
+typedef struct {
+	git_repository *repo;
+	git_iterator *target;
+	git_diff *diff;
+	git_checkout_options opts;
+	bool opts_free_baseline;
+	char *pfx;
+	git_index *index;
+	git_pool pool;
+	git_vector removes;
+	git_vector remove_conflicts;
+	git_vector update_conflicts;
+	git_vector *update_reuc;
+	git_vector *update_names;
+	git_buf target_path;
+	size_t target_len;
+	git_buf tmp;
+	unsigned int strategy;
+	int can_symlink;
+	int respect_filemode;
+	bool reload_submodules;
+	size_t total_steps;
+	size_t completed_steps;
+	git_checkout_perfdata perfdata;
+	git_strmap *mkdir_map;
+	git_attr_session attr_session;
+} checkout_data;
+
+typedef struct {
+	const git_index_entry *ancestor;
+	const git_index_entry *ours;
+	const git_index_entry *theirs;
+
+	int name_collision:1,
+		directoryfile:1,
+		one_to_two:1,
+		binary:1,
+		submodule:1;
+} checkout_conflictdata;
+
+static int checkout_notify(
+	checkout_data *data,
+	git_checkout_notify_t why,
+	const git_diff_delta *delta,
+	const git_index_entry *wditem)
+{
+	git_diff_file wdfile;
+	const git_diff_file *baseline = NULL, *target = NULL, *workdir = NULL;
+	const char *path = NULL;
+
+	if (!data->opts.notify_cb ||
+		(why & data->opts.notify_flags) == 0)
+		return 0;
+
+	if (wditem) {
+		memset(&wdfile, 0, sizeof(wdfile));
+
+		git_oid_cpy(&wdfile.id, &wditem->id);
+		wdfile.path = wditem->path;
+		wdfile.size = wditem->file_size;
+		wdfile.flags = GIT_DIFF_FLAG_VALID_ID;
+		wdfile.mode = wditem->mode;
+
+		workdir = &wdfile;
+
+		path = wditem->path;
+	}
+
+	if (delta) {
+		switch (delta->status) {
+		case GIT_DELTA_UNMODIFIED:
+		case GIT_DELTA_MODIFIED:
+		case GIT_DELTA_TYPECHANGE:
+		default:
+			baseline = &delta->old_file;
+			target = &delta->new_file;
+			break;
+		case GIT_DELTA_ADDED:
+		case GIT_DELTA_IGNORED:
+		case GIT_DELTA_UNTRACKED:
+		case GIT_DELTA_UNREADABLE:
+			target = &delta->new_file;
+			break;
+		case GIT_DELTA_DELETED:
+			baseline = &delta->old_file;
+			break;
+		}
+
+		path = delta->old_file.path;
+	}
+
+	{
+		int error = data->opts.notify_cb(
+			why, path, baseline, target, workdir, data->opts.notify_payload);
+
+		return giterr_set_after_callback_function(
+			error, "git_checkout notification");
+	}
+}
+
+GIT_INLINE(bool) is_workdir_base_or_new(
+	const git_oid *workdir_id,
+	const git_diff_file *baseitem,
+	const git_diff_file *newitem)
+{
+	return (git_oid__cmp(&baseitem->id, workdir_id) == 0 ||
+		git_oid__cmp(&newitem->id, workdir_id) == 0);
+}
+
+GIT_INLINE(bool) is_filemode_changed(git_filemode_t a, git_filemode_t b, int respect_filemode)
+{
+	/* If core.filemode = false, ignore links in the repository and executable bit changes */
+	if (!respect_filemode) {
+		if (a == S_IFLNK)
+			a = GIT_FILEMODE_BLOB;
+		if (b == S_IFLNK)
+			b = GIT_FILEMODE_BLOB;
+
+		a &= ~0111;
+		b &= ~0111;
+	}
+
+	return (a != b);
+}
+
+static bool checkout_is_workdir_modified(
+	checkout_data *data,
+	const git_diff_file *baseitem,
+	const git_diff_file *newitem,
+	const git_index_entry *wditem)
+{
+	git_oid oid;
+	const git_index_entry *ie;
+
+	/* handle "modified" submodule */
+	if (wditem->mode == GIT_FILEMODE_COMMIT) {
+		git_submodule *sm;
+		unsigned int sm_status = 0;
+		const git_oid *sm_oid = NULL;
+		bool rval = false;
+
+		if (git_submodule_lookup(&sm, data->repo, wditem->path) < 0) {
+			giterr_clear();
+			return true;
+		}
+
+		if (git_submodule_status(&sm_status, data->repo, wditem->path, GIT_SUBMODULE_IGNORE_UNSPECIFIED) < 0 ||
+			GIT_SUBMODULE_STATUS_IS_WD_DIRTY(sm_status))
+			rval = true;
+		else if ((sm_oid = git_submodule_wd_id(sm)) == NULL)
+			rval = false;
+		else
+			rval = (git_oid__cmp(&baseitem->id, sm_oid) != 0);
+
+		git_submodule_free(sm);
+		return rval;
+	}
+
+	/*
+	 * Look at the cache to decide if the workdir is modified: if the
+	 * cache contents match the workdir contents, then we do not need
+	 * to examine the working directory directly, instead we can
+	 * examine the cache to see if _it_ has been modified.  This allows
+	 * us to avoid touching the disk.
+	 */
+	ie = git_index_get_bypath(data->index, wditem->path, 0);
+
+	if (ie != NULL &&
+		git_index_time_eq(&wditem->mtime, &ie->mtime) &&
+		wditem->file_size == ie->file_size &&
+		!is_filemode_changed(wditem->mode, ie->mode, data->respect_filemode)) {
+
+		/* The workdir is modified iff the index entry is modified */
+		return !is_workdir_base_or_new(&ie->id, baseitem, newitem) ||
+			is_filemode_changed(baseitem->mode, ie->mode, data->respect_filemode);
+	}
+
+	/* depending on where base is coming from, we may or may not know
+	 * the actual size of the data, so we can't rely on this shortcut.
+	 */
+	if (baseitem->size && wditem->file_size != baseitem->size)
+		return true;
+
+	/* if the workdir item is a directory, it cannot be a modified file */
+	if (S_ISDIR(wditem->mode))
+		return false;
+
+	if (is_filemode_changed(baseitem->mode, wditem->mode, data->respect_filemode))
+		return true;
+
+	if (git_diff__oid_for_entry(&oid, data->diff, wditem, wditem->mode, NULL) < 0)
+		return false;
+
+	/* Allow the checkout if the workdir is not modified *or* if the checkout
+	 * target's contents are already in the working directory.
+	 */
+	return !is_workdir_base_or_new(&oid, baseitem, newitem);
+}
+
+#define CHECKOUT_ACTION_IF(FLAG,YES,NO) \
+	((data->strategy & GIT_CHECKOUT_##FLAG) ? CHECKOUT_ACTION__##YES : CHECKOUT_ACTION__##NO)
+
+static int checkout_action_common(
+	int *action,
+	checkout_data *data,
+	const git_diff_delta *delta,
+	const git_index_entry *wd)
+{
+	git_checkout_notify_t notify = GIT_CHECKOUT_NOTIFY_NONE;
+
+	if ((data->strategy & GIT_CHECKOUT_UPDATE_ONLY) != 0)
+		*action = (*action & ~CHECKOUT_ACTION__REMOVE);
+
+	if ((*action & CHECKOUT_ACTION__UPDATE_BLOB) != 0) {
+		if (S_ISGITLINK(delta->new_file.mode))
+			*action = (*action & ~CHECKOUT_ACTION__UPDATE_BLOB) |
+				CHECKOUT_ACTION__UPDATE_SUBMODULE;
+
+		/* to "update" a symlink, we must remove the old one first */
+		if (delta->new_file.mode == GIT_FILEMODE_LINK && wd != NULL)
+			*action |= CHECKOUT_ACTION__REMOVE;
+
+		/* if the file is on disk and doesn't match our mode, force update */
+		if (wd &&
+			GIT_PERMS_IS_EXEC(wd->mode) !=
+			GIT_PERMS_IS_EXEC(delta->new_file.mode))
+				*action |= CHECKOUT_ACTION__REMOVE;
+
+		notify = GIT_CHECKOUT_NOTIFY_UPDATED;
+	}
+
+	if ((*action & CHECKOUT_ACTION__CONFLICT) != 0)
+		notify = GIT_CHECKOUT_NOTIFY_CONFLICT;
+
+	return checkout_notify(data, notify, delta, wd);
+}
+
+static int checkout_action_no_wd(
+	int *action,
+	checkout_data *data,
+	const git_diff_delta *delta)
+{
+	int error = 0;
+
+	*action = CHECKOUT_ACTION__NONE;
+
+	switch (delta->status) {
+	case GIT_DELTA_UNMODIFIED: /* case 12 */
+		error = checkout_notify(data, GIT_CHECKOUT_NOTIFY_DIRTY, delta, NULL);
+		if (error)
+			return error;
+		*action = CHECKOUT_ACTION_IF(RECREATE_MISSING, UPDATE_BLOB, NONE);
+		break;
+	case GIT_DELTA_ADDED:    /* case 2 or 28 (and 5 but not really) */
+		*action = CHECKOUT_ACTION_IF(SAFE, UPDATE_BLOB, NONE);
+		break;
+	case GIT_DELTA_MODIFIED: /* case 13 (and 35 but not really) */
+		*action = CHECKOUT_ACTION_IF(RECREATE_MISSING, UPDATE_BLOB, CONFLICT);
+		break;
+	case GIT_DELTA_TYPECHANGE: /* case 21 (B->T) and 28 (T->B)*/
+		if (delta->new_file.mode == GIT_FILEMODE_TREE)
+			*action = CHECKOUT_ACTION_IF(SAFE, UPDATE_BLOB, NONE);
+		break;
+	case GIT_DELTA_DELETED: /* case 8 or 25 */
+		*action = CHECKOUT_ACTION_IF(SAFE, REMOVE, NONE);
+		break;
+	default: /* impossible */
+		break;
+	}
+
+	return checkout_action_common(action, data, delta, NULL);
+}
+
+static int checkout_target_fullpath(
+	git_buf **out, checkout_data *data, const char *path)
+{
+	git_buf_truncate(&data->target_path, data->target_len);
+
+	if (path && git_buf_puts(&data->target_path, path) < 0)
+		return -1;
+
+	*out = &data->target_path;
+
+	return 0;
+}
+
+static bool wd_item_is_removable(
+	checkout_data *data, const git_index_entry *wd)
+{
+	git_buf *full;
+
+	if (wd->mode != GIT_FILEMODE_TREE)
+		return true;
+
+	if (checkout_target_fullpath(&full, data, wd->path) < 0)
+		return false;
+
+	return !full || !git_path_contains(full, DOT_GIT);
+}
+
+static int checkout_queue_remove(checkout_data *data, const char *path)
+{
+	char *copy = git_pool_strdup(&data->pool, path);
+	GITERR_CHECK_ALLOC(copy);
+	return git_vector_insert(&data->removes, copy);
+}
+
+/* note that this advances the iterator over the wd item */
+static int checkout_action_wd_only(
+	checkout_data *data,
+	git_iterator *workdir,
+	const git_index_entry **wditem,
+	git_vector *pathspec)
+{
+	int error = 0;
+	bool remove = false;
+	git_checkout_notify_t notify = GIT_CHECKOUT_NOTIFY_NONE;
+	const git_index_entry *wd = *wditem;
+
+	if (!git_pathspec__match(
+			pathspec, wd->path,
+			(data->strategy & GIT_CHECKOUT_DISABLE_PATHSPEC_MATCH) != 0,
+			git_iterator_ignore_case(workdir), NULL, NULL))
+		return git_iterator_advance(wditem, workdir);
+
+	/* check if item is tracked in the index but not in the checkout diff */
+	if (data->index != NULL) {
+		size_t pos;
+
+		error = git_index__find_pos(
+			&pos, data->index, wd->path, 0, GIT_INDEX_STAGE_ANY);
+
+		if (wd->mode != GIT_FILEMODE_TREE) {
+			if (!error) { /* found by git_index__find_pos call */
+				notify = GIT_CHECKOUT_NOTIFY_DIRTY;
+				remove = ((data->strategy & GIT_CHECKOUT_FORCE) != 0);
+			} else if (error != GIT_ENOTFOUND)
+				return error;
+			else
+				error = 0; /* git_index__find_pos does not set error msg */
+		} else {
+			/* for tree entries, we have to see if there are any index
+			 * entries that are contained inside that tree
+			 */
+			const git_index_entry *e = git_index_get_byindex(data->index, pos);
+
+			if (e != NULL && data->diff->pfxcomp(e->path, wd->path) == 0)
+				return git_iterator_advance_into(wditem, workdir);
+		}
+	}
+
+	if (notify != GIT_CHECKOUT_NOTIFY_NONE) {
+		/* if we found something in the index, notify and advance */
+		if ((error = checkout_notify(data, notify, NULL, wd)) != 0)
+			return error;
+
+		if (remove && wd_item_is_removable(data, wd))
+			error = checkout_queue_remove(data, wd->path);
+
+		if (!error)
+			error = git_iterator_advance(wditem, workdir);
+	} else {
+		/* untracked or ignored - can't know which until we advance through */
+		bool over = false, removable = wd_item_is_removable(data, wd);
+		git_iterator_status_t untracked_state;
+
+		/* copy the entry for issuing notification callback later */
+		git_index_entry saved_wd = *wd;
+		git_buf_sets(&data->tmp, wd->path);
+		saved_wd.path = data->tmp.ptr;
+
+		error = git_iterator_advance_over(
+			wditem, &untracked_state, workdir);
+		if (error == GIT_ITEROVER)
+			over = true;
+		else if (error < 0)
+			return error;
+
+		if (untracked_state == GIT_ITERATOR_STATUS_IGNORED) {
+			notify = GIT_CHECKOUT_NOTIFY_IGNORED;
+			remove = ((data->strategy & GIT_CHECKOUT_REMOVE_IGNORED) != 0);
+		} else {
+			notify = GIT_CHECKOUT_NOTIFY_UNTRACKED;
+			remove = ((data->strategy & GIT_CHECKOUT_REMOVE_UNTRACKED) != 0);
+		}
+
+		if ((error = checkout_notify(data, notify, NULL, &saved_wd)) != 0)
+			return error;
+
+		if (remove && removable)
+			error = checkout_queue_remove(data, saved_wd.path);
+
+		if (!error && over) /* restore ITEROVER if needed */
+			error = GIT_ITEROVER;
+	}
+
+	return error;
+}
+
+static bool submodule_is_config_only(
+	checkout_data *data,
+	const char *path)
+{
+	git_submodule *sm = NULL;
+	unsigned int sm_loc = 0;
+	bool rval = false;
+
+	if (git_submodule_lookup(&sm, data->repo, path) < 0)
+		return true;
+
+	if (git_submodule_location(&sm_loc, sm) < 0 ||
+		sm_loc == GIT_SUBMODULE_STATUS_IN_CONFIG)
+		rval = true;
+
+	git_submodule_free(sm);
+
+	return rval;
+}
+
+static bool checkout_is_empty_dir(checkout_data *data, const char *path)
+{
+	git_buf *fullpath;
+
+	if (checkout_target_fullpath(&fullpath, data, path) < 0)
+		return false;
+
+	return git_path_is_empty_dir(fullpath->ptr);
+}
+
+static int checkout_action_with_wd(
+	int *action,
+	checkout_data *data,
+	const git_diff_delta *delta,
+	git_iterator *workdir,
+	const git_index_entry *wd)
+{
+	*action = CHECKOUT_ACTION__NONE;
+
+	switch (delta->status) {
+	case GIT_DELTA_UNMODIFIED: /* case 14/15 or 33 */
+		if (checkout_is_workdir_modified(data, &delta->old_file, &delta->new_file, wd)) {
+			GITERR_CHECK_ERROR(
+				checkout_notify(data, GIT_CHECKOUT_NOTIFY_DIRTY, delta, wd) );
+			*action = CHECKOUT_ACTION_IF(FORCE, UPDATE_BLOB, NONE);
+		}
+		break;
+	case GIT_DELTA_ADDED: /* case 3, 4 or 6 */
+		if (git_iterator_current_is_ignored(workdir))
+			*action = CHECKOUT_ACTION_IF(DONT_OVERWRITE_IGNORED, CONFLICT, UPDATE_BLOB);
+		else
+			*action = CHECKOUT_ACTION_IF(FORCE, UPDATE_BLOB, CONFLICT);
+		break;
+	case GIT_DELTA_DELETED: /* case 9 or 10 (or 26 but not really) */
+		if (checkout_is_workdir_modified(data, &delta->old_file, &delta->new_file, wd))
+			*action = CHECKOUT_ACTION_IF(FORCE, REMOVE, CONFLICT);
+		else
+			*action = CHECKOUT_ACTION_IF(SAFE, REMOVE, NONE);
+		break;
+	case GIT_DELTA_MODIFIED: /* case 16, 17, 18 (or 36 but not really) */
+		if (wd->mode != GIT_FILEMODE_COMMIT &&
+			checkout_is_workdir_modified(data, &delta->old_file, &delta->new_file, wd))
+			*action = CHECKOUT_ACTION_IF(FORCE, UPDATE_BLOB, CONFLICT);
+		else
+			*action = CHECKOUT_ACTION_IF(SAFE, UPDATE_BLOB, NONE);
+		break;
+	case GIT_DELTA_TYPECHANGE: /* case 22, 23, 29, 30 */
+		if (delta->old_file.mode == GIT_FILEMODE_TREE) {
+			if (wd->mode == GIT_FILEMODE_TREE)
+				/* either deleting items in old tree will delete the wd dir,
+				 * or we'll get a conflict when we attempt blob update...
+				 */
+				*action = CHECKOUT_ACTION_IF(SAFE, UPDATE_BLOB, NONE);
+			else if (wd->mode == GIT_FILEMODE_COMMIT) {
+				/* workdir is possibly a "phantom" submodule - treat as a
+				 * tree if the only submodule info came from the config
+				 */
+				if (submodule_is_config_only(data, wd->path))
+					*action = CHECKOUT_ACTION_IF(SAFE, UPDATE_BLOB, NONE);
+				else
+					*action = CHECKOUT_ACTION_IF(FORCE, REMOVE_AND_UPDATE, CONFLICT);
+			} else
+				*action = CHECKOUT_ACTION_IF(FORCE, REMOVE, CONFLICT);
+		}
+		else if (checkout_is_workdir_modified(data, &delta->old_file, &delta->new_file, wd))
+			*action = CHECKOUT_ACTION_IF(FORCE, REMOVE_AND_UPDATE, CONFLICT);
+		else
+			*action = CHECKOUT_ACTION_IF(SAFE, REMOVE_AND_UPDATE, NONE);
+
+		/* don't update if the typechange is to a tree */
+		if (delta->new_file.mode == GIT_FILEMODE_TREE)
+			*action = (*action & ~CHECKOUT_ACTION__UPDATE_BLOB);
+		break;
+	default: /* impossible */
+		break;
+	}
+
+	return checkout_action_common(action, data, delta, wd);
+}
+
+static int checkout_action_with_wd_blocker(
+	int *action,
+	checkout_data *data,
+	const git_diff_delta *delta,
+	const git_index_entry *wd)
+{
+	*action = CHECKOUT_ACTION__NONE;
+
+	switch (delta->status) {
+	case GIT_DELTA_UNMODIFIED:
+		/* should show delta as dirty / deleted */
+		GITERR_CHECK_ERROR(
+			checkout_notify(data, GIT_CHECKOUT_NOTIFY_DIRTY, delta, wd) );
+		*action = CHECKOUT_ACTION_IF(FORCE, REMOVE_AND_UPDATE, NONE);
+		break;
+	case GIT_DELTA_ADDED:
+	case GIT_DELTA_MODIFIED:
+		*action = CHECKOUT_ACTION_IF(FORCE, REMOVE_AND_UPDATE, CONFLICT);
+		break;
+	case GIT_DELTA_DELETED:
+		*action = CHECKOUT_ACTION_IF(FORCE, REMOVE, CONFLICT);
+		break;
+	case GIT_DELTA_TYPECHANGE:
+		/* not 100% certain about this... */
+		*action = CHECKOUT_ACTION_IF(FORCE, REMOVE_AND_UPDATE, CONFLICT);
+		break;
+	default: /* impossible */
+		break;
+	}
+
+	return checkout_action_common(action, data, delta, wd);
+}
+
+static int checkout_action_with_wd_dir(
+	int *action,
+	checkout_data *data,
+	const git_diff_delta *delta,
+	git_iterator *workdir,
+	const git_index_entry *wd)
+{
+	*action = CHECKOUT_ACTION__NONE;
+
+	switch (delta->status) {
+	case GIT_DELTA_UNMODIFIED: /* case 19 or 24 (or 34 but not really) */
+		GITERR_CHECK_ERROR(
+			checkout_notify(data, GIT_CHECKOUT_NOTIFY_DIRTY, delta, NULL));
+		GITERR_CHECK_ERROR(
+			checkout_notify(data, GIT_CHECKOUT_NOTIFY_UNTRACKED, NULL, wd));
+		*action = CHECKOUT_ACTION_IF(FORCE, REMOVE_AND_UPDATE, NONE);
+		break;
+	case GIT_DELTA_ADDED:/* case 4 (and 7 for dir) */
+	case GIT_DELTA_MODIFIED: /* case 20 (or 37 but not really) */
+		if (delta->old_file.mode == GIT_FILEMODE_COMMIT)
+			/* expected submodule (and maybe found one) */;
+		else if (delta->new_file.mode != GIT_FILEMODE_TREE)
+			*action = git_iterator_current_is_ignored(workdir) ?
+				CHECKOUT_ACTION_IF(DONT_OVERWRITE_IGNORED, CONFLICT, REMOVE_AND_UPDATE) :
+				CHECKOUT_ACTION_IF(FORCE, REMOVE_AND_UPDATE, CONFLICT);
+		break;
+	case GIT_DELTA_DELETED: /* case 11 (and 27 for dir) */
+		if (delta->old_file.mode != GIT_FILEMODE_TREE)
+			GITERR_CHECK_ERROR(
+				checkout_notify(data, GIT_CHECKOUT_NOTIFY_UNTRACKED, NULL, wd));
+		break;
+	case GIT_DELTA_TYPECHANGE: /* case 24 or 31 */
+		if (delta->old_file.mode == GIT_FILEMODE_TREE) {
+			/* For typechange from dir, remove dir and add blob, but it is
+			 * not safe to remove dir if it contains modified files.
+			 * However, safely removing child files will remove the parent
+			 * directory if is it left empty, so we can defer removing the
+			 * dir and it will succeed if no children are left.
+			 */
+			*action = CHECKOUT_ACTION_IF(SAFE, UPDATE_BLOB, NONE);
+		}
+		else if (delta->new_file.mode != GIT_FILEMODE_TREE)
+			/* For typechange to dir, dir is already created so no action */
+			*action = CHECKOUT_ACTION_IF(FORCE, REMOVE_AND_UPDATE, CONFLICT);
+		break;
+	default: /* impossible */
+		break;
+	}
+
+	return checkout_action_common(action, data, delta, wd);
+}
+
+static int checkout_action_with_wd_dir_empty(
+	int *action,
+	checkout_data *data,
+	const git_diff_delta *delta)
+{
+	int error = checkout_action_no_wd(action, data, delta);
+
+	/* We can always safely remove an empty directory. */
+	if (error == 0 && *action != CHECKOUT_ACTION__NONE)
+		*action |= CHECKOUT_ACTION__REMOVE;
+
+	return error;
+}
+
+static int checkout_action(
+	int *action,
+	checkout_data *data,
+	git_diff_delta *delta,
+	git_iterator *workdir,
+	const git_index_entry **wditem,
+	git_vector *pathspec)
+{
+	int cmp = -1, error;
+	int (*strcomp)(const char *, const char *) = data->diff->strcomp;
+	int (*pfxcomp)(const char *str, const char *pfx) = data->diff->pfxcomp;
+	int (*advance)(const git_index_entry **, git_iterator *) = NULL;
+
+	/* move workdir iterator to follow along with deltas */
+
+	while (1) {
+		const git_index_entry *wd = *wditem;
+
+		if (!wd)
+			return checkout_action_no_wd(action, data, delta);
+
+		cmp = strcomp(wd->path, delta->old_file.path);
+
+		/* 1. wd before delta ("a/a" before "a/b")
+		 * 2. wd prefixes delta & should expand ("a/" before "a/b")
+		 * 3. wd prefixes delta & cannot expand ("a/b" before "a/b/c")
+		 * 4. wd equals delta ("a/b" and "a/b")
+		 * 5. wd after delta & delta prefixes wd ("a/b/c" after "a/b/" or "a/b")
+		 * 6. wd after delta ("a/c" after "a/b")
+		 */
+
+		if (cmp < 0) {
+			cmp = pfxcomp(delta->old_file.path, wd->path);
+
+			if (cmp == 0) {
+				if (wd->mode == GIT_FILEMODE_TREE) {
+					/* case 2 - entry prefixed by workdir tree */
+					error = git_iterator_advance_into(wditem, workdir);
+					if (error < 0 && error != GIT_ITEROVER)
+						goto done;
+					continue;
+				}
+
+				/* case 3 maybe - wd contains non-dir where dir expected */
+				if (delta->old_file.path[strlen(wd->path)] == '/') {
+					error = checkout_action_with_wd_blocker(
+						action, data, delta, wd);
+					advance = git_iterator_advance;
+					goto done;
+				}
+			}
+
+			/* case 1 - handle wd item (if it matches pathspec) */
+			error = checkout_action_wd_only(data, workdir, wditem, pathspec);
+			if (error && error != GIT_ITEROVER)
+				goto done;
+			continue;
+		}
+
+		if (cmp == 0) {
+			/* case 4 */
+			error = checkout_action_with_wd(action, data, delta, workdir, wd);
+			advance = git_iterator_advance;
+			goto done;
+		}
+
+		cmp = pfxcomp(wd->path, delta->old_file.path);
+
+		if (cmp == 0) { /* case 5 */
+			if (wd->path[strlen(delta->old_file.path)] != '/')
+				return checkout_action_no_wd(action, data, delta);
+
+			if (delta->status == GIT_DELTA_TYPECHANGE) {
+				if (delta->old_file.mode == GIT_FILEMODE_TREE) {
+					error = checkout_action_with_wd(action, data, delta, workdir, wd);
+					advance = git_iterator_advance_into;
+					goto done;
+				}
+
+				if (delta->new_file.mode == GIT_FILEMODE_TREE ||
+					delta->new_file.mode == GIT_FILEMODE_COMMIT ||
+					delta->old_file.mode == GIT_FILEMODE_COMMIT)
+				{
+					error = checkout_action_with_wd(action, data, delta, workdir, wd);
+					advance = git_iterator_advance;
+					goto done;
+				}
+			}
+
+			return checkout_is_empty_dir(data, wd->path) ?
+				checkout_action_with_wd_dir_empty(action, data, delta) :
+				checkout_action_with_wd_dir(action, data, delta, workdir, wd);
+		}
+
+		/* case 6 - wd is after delta */
+		return checkout_action_no_wd(action, data, delta);
+	}
+
+done:
+	if (!error && advance != NULL &&
+		(error = advance(wditem, workdir)) < 0) {
+		*wditem = NULL;
+		if (error == GIT_ITEROVER)
+			error = 0;
+	}
+
+	return error;
+}
+
+static int checkout_remaining_wd_items(
+	checkout_data *data,
+	git_iterator *workdir,
+	const git_index_entry *wd,
+	git_vector *spec)
+{
+	int error = 0;
+
+	while (wd && !error)
+		error = checkout_action_wd_only(data, workdir, &wd, spec);
+
+	if (error == GIT_ITEROVER)
+		error = 0;
+
+	return error;
+}
+
+GIT_INLINE(int) checkout_idxentry_cmp(
+	const git_index_entry *a,
+	const git_index_entry *b)
+{
+	if (!a && !b)
+		return 0;
+	else if (!a && b)
+		return -1;
+	else if(a && !b)
+		return 1;
+	else
+		return strcmp(a->path, b->path);
+}
+
+static int checkout_conflictdata_cmp(const void *a, const void *b)
+{
+	const checkout_conflictdata *ca = a;
+	const checkout_conflictdata *cb = b;
+	int diff;
+
+	if ((diff = checkout_idxentry_cmp(ca->ancestor, cb->ancestor)) == 0 &&
+		(diff = checkout_idxentry_cmp(ca->ours, cb->theirs)) == 0)
+		diff = checkout_idxentry_cmp(ca->theirs, cb->theirs);
+
+	return diff;
+}
+
+int checkout_conflictdata_empty(
+	const git_vector *conflicts, size_t idx, void *payload)
+{
+	checkout_conflictdata *conflict;
+
+	GIT_UNUSED(payload);
+
+	if ((conflict = git_vector_get(conflicts, idx)) == NULL)
+		return -1;
+
+	if (conflict->ancestor || conflict->ours || conflict->theirs)
+		return 0;
+
+	git__free(conflict);
+	return 1;
+}
+
+GIT_INLINE(bool) conflict_pathspec_match(
+	checkout_data *data,
+	git_iterator *workdir,
+	git_vector *pathspec,
+	const git_index_entry *ancestor,
+	const git_index_entry *ours,
+	const git_index_entry *theirs)
+{
+	/* if the pathspec matches ours *or* theirs, proceed */
+	if (ours && git_pathspec__match(pathspec, ours->path,
+		(data->strategy & GIT_CHECKOUT_DISABLE_PATHSPEC_MATCH) != 0,
+		git_iterator_ignore_case(workdir), NULL, NULL))
+		return true;
+
+	if (theirs && git_pathspec__match(pathspec, theirs->path,
+		(data->strategy & GIT_CHECKOUT_DISABLE_PATHSPEC_MATCH) != 0,
+		git_iterator_ignore_case(workdir), NULL, NULL))
+		return true;
+
+	if (ancestor && git_pathspec__match(pathspec, ancestor->path,
+		(data->strategy & GIT_CHECKOUT_DISABLE_PATHSPEC_MATCH) != 0,
+		git_iterator_ignore_case(workdir), NULL, NULL))
+		return true;
+
+	return false;
+}
+
+GIT_INLINE(int) checkout_conflict_detect_submodule(checkout_conflictdata *conflict)
+{
+	conflict->submodule = ((conflict->ancestor && S_ISGITLINK(conflict->ancestor->mode)) ||
+		(conflict->ours && S_ISGITLINK(conflict->ours->mode)) ||
+		(conflict->theirs && S_ISGITLINK(conflict->theirs->mode)));
+	return 0;
+}
+
+GIT_INLINE(int) checkout_conflict_detect_binary(git_repository *repo, checkout_conflictdata *conflict)
+{
+	git_blob *ancestor_blob = NULL, *our_blob = NULL, *their_blob = NULL;
+	int error = 0;
+
+	if (conflict->submodule)
+		return 0;
+
+	if (conflict->ancestor) {
+		if ((error = git_blob_lookup(&ancestor_blob, repo, &conflict->ancestor->id)) < 0)
+			goto done;
+
+		conflict->binary = git_blob_is_binary(ancestor_blob);
+	}
+
+	if (!conflict->binary && conflict->ours) {
+		if ((error = git_blob_lookup(&our_blob, repo, &conflict->ours->id)) < 0)
+			goto done;
+
+		conflict->binary = git_blob_is_binary(our_blob);
+	}
+
+	if (!conflict->binary && conflict->theirs) {
+		if ((error = git_blob_lookup(&their_blob, repo, &conflict->theirs->id)) < 0)
+			goto done;
+
+		conflict->binary = git_blob_is_binary(their_blob);
+	}
+
+done:
+	git_blob_free(ancestor_blob);
+	git_blob_free(our_blob);
+	git_blob_free(their_blob);
+
+	return error;
+}
+
+static int checkout_conflict_append_update(
+	const git_index_entry *ancestor,
+	const git_index_entry *ours,
+	const git_index_entry *theirs,
+	void *payload)
+{
+	checkout_data *data = payload;
+	checkout_conflictdata *conflict;
+	int error;
+
+	conflict = git__calloc(1, sizeof(checkout_conflictdata));
+	GITERR_CHECK_ALLOC(conflict);
+
+	conflict->ancestor = ancestor;
+	conflict->ours = ours;
+	conflict->theirs = theirs;
+
+	if ((error = checkout_conflict_detect_submodule(conflict)) < 0 ||
+		(error = checkout_conflict_detect_binary(data->repo, conflict)) < 0)
+	{
+		git__free(conflict);
+		return error;
+	}
+
+	if (git_vector_insert(&data->update_conflicts, conflict))
+		return -1;
+
+	return 0;
+}
+
+static int checkout_conflicts_foreach(
+	checkout_data *data,
+	git_index *index,
+	git_iterator *workdir,
+	git_vector *pathspec,
+	int (*cb)(const git_index_entry *, const git_index_entry *, const git_index_entry *, void *),
+	void *payload)
+{
+	git_index_conflict_iterator *iterator = NULL;
+	const git_index_entry *ancestor, *ours, *theirs;
+	int error = 0;
+
+	if ((error = git_index_conflict_iterator_new(&iterator, index)) < 0)
+		goto done;
+
+	/* Collect the conflicts */
+	while ((error = git_index_conflict_next(&ancestor, &ours, &theirs, iterator)) == 0) {
+		if (!conflict_pathspec_match(data, workdir, pathspec, ancestor, ours, theirs))
+			continue;
+
+		if ((error = cb(ancestor, ours, theirs, payload)) < 0)
+			goto done;
+	}
+
+	if (error == GIT_ITEROVER)
+		error = 0;
+
+done:
+	git_index_conflict_iterator_free(iterator);
+
+	return error;
+}
+
+static int checkout_conflicts_load(checkout_data *data, git_iterator *workdir, git_vector *pathspec)
+{
+	git_index *index;
+
+	/* Only write conficts from sources that have them: indexes. */
+	if ((index = git_iterator_index(data->target)) == NULL)
+		return 0;
+
+	data->update_conflicts._cmp = checkout_conflictdata_cmp;
+
+	if (checkout_conflicts_foreach(data, index, workdir, pathspec, checkout_conflict_append_update, data) < 0)
+		return -1;
+
+	/* Collect the REUC and NAME entries */
+	data->update_reuc = &index->reuc;
+	data->update_names = &index->names;
+
+	return 0;
+}
+
+GIT_INLINE(int) checkout_conflicts_cmp_entry(
+	const char *path,
+	const git_index_entry *entry)
+{
+	return strcmp((const char *)path, entry->path);
+}
+
+static int checkout_conflicts_cmp_ancestor(const void *p, const void *c)
+{
+	const char *path = p;
+	const checkout_conflictdata *conflict = c;
+
+	if (!conflict->ancestor)
+		return 1;
+
+	return checkout_conflicts_cmp_entry(path, conflict->ancestor);
+}
+
+static checkout_conflictdata *checkout_conflicts_search_ancestor(
+	checkout_data *data,
+	const char *path)
+{
+	size_t pos;
+
+	if (git_vector_bsearch2(&pos, &data->update_conflicts, checkout_conflicts_cmp_ancestor, path) < 0)
+		return NULL;
+
+	return git_vector_get(&data->update_conflicts, pos);
+}
+
+static checkout_conflictdata *checkout_conflicts_search_branch(
+	checkout_data *data,
+	const char *path)
+{
+	checkout_conflictdata *conflict;
+	size_t i;
+
+	git_vector_foreach(&data->update_conflicts, i, conflict) {
+		int cmp = -1;
+
+		if (conflict->ancestor)
+			break;
+
+		if (conflict->ours)
+			cmp = checkout_conflicts_cmp_entry(path, conflict->ours);
+		else if (conflict->theirs)
+			cmp = checkout_conflicts_cmp_entry(path, conflict->theirs);
+
+		if (cmp == 0)
+			return conflict;
+	}
+
+	return NULL;
+}
+
+static int checkout_conflicts_load_byname_entry(
+	checkout_conflictdata **ancestor_out,
+	checkout_conflictdata **ours_out,
+	checkout_conflictdata **theirs_out,
+	checkout_data *data,
+	const git_index_name_entry *name_entry)
+{
+	checkout_conflictdata *ancestor, *ours = NULL, *theirs = NULL;
+	int error = 0;
+
+	*ancestor_out = NULL;
+	*ours_out = NULL;
+	*theirs_out = NULL;
+
+	if (!name_entry->ancestor) {
+		giterr_set(GITERR_INDEX, "a NAME entry exists without an ancestor");
+		error = -1;
+		goto done;
+	}
+
+	if (!name_entry->ours && !name_entry->theirs) {
+		giterr_set(GITERR_INDEX, "a NAME entry exists without an ours or theirs");
+		error = -1;
+		goto done;
+	}
+
+	if ((ancestor = checkout_conflicts_search_ancestor(data,
+		name_entry->ancestor)) == NULL) {
+		giterr_set(GITERR_INDEX,
+			"a NAME entry referenced ancestor entry '%s' which does not exist in the main index",
+			name_entry->ancestor);
+		error = -1;
+		goto done;
+	}
+
+	if (name_entry->ours) {
+		if (strcmp(name_entry->ancestor, name_entry->ours) == 0)
+			ours = ancestor;
+		else if ((ours = checkout_conflicts_search_branch(data, name_entry->ours)) == NULL ||
+			ours->ours == NULL) {
+			giterr_set(GITERR_INDEX,
+				"a NAME entry referenced our entry '%s' which does not exist in the main index",
+				name_entry->ours);
+			error = -1;
+			goto done;
+		}
+	}
+
+	if (name_entry->theirs) {
+		if (strcmp(name_entry->ancestor, name_entry->theirs) == 0)
+			theirs = ancestor;
+		else if (name_entry->ours && strcmp(name_entry->ours, name_entry->theirs) == 0)
+			theirs = ours;
+		else if ((theirs = checkout_conflicts_search_branch(data, name_entry->theirs)) == NULL ||
+			theirs->theirs == NULL) {
+			giterr_set(GITERR_INDEX,
+				"a NAME entry referenced their entry '%s' which does not exist in the main index",
+				name_entry->theirs);
+			error = -1;
+			goto done;
+		}
+	}
+
+	*ancestor_out = ancestor;
+	*ours_out = ours;
+	*theirs_out = theirs;
+
+done:
+	return error;
+}
+
+static int checkout_conflicts_coalesce_renames(
+	checkout_data *data)
+{
+	git_index *index;
+	const git_index_name_entry *name_entry;
+	checkout_conflictdata *ancestor_conflict, *our_conflict, *their_conflict;
+	size_t i, names;
+	int error = 0;
+
+	if ((index = git_iterator_index(data->target)) == NULL)
+		return 0;
+
+	/* Juggle entries based on renames */
+	names = git_index_name_entrycount(index);
+
+	for (i = 0; i < names; i++) {
+		name_entry = git_index_name_get_byindex(index, i);
+
+		if ((error = checkout_conflicts_load_byname_entry(
+			&ancestor_conflict, &our_conflict, &their_conflict,
+			data, name_entry)) < 0)
+			goto done;
+
+		if (our_conflict && our_conflict != ancestor_conflict) {
+			ancestor_conflict->ours = our_conflict->ours;
+			our_conflict->ours = NULL;
+
+			if (our_conflict->theirs)
+				our_conflict->name_collision = 1;
+
+			if (our_conflict->name_collision)
+				ancestor_conflict->name_collision = 1;
+		}
+
+		if (their_conflict && their_conflict != ancestor_conflict) {
+			ancestor_conflict->theirs = their_conflict->theirs;
+			their_conflict->theirs = NULL;
+
+			if (their_conflict->ours)
+				their_conflict->name_collision = 1;
+
+			if (their_conflict->name_collision)
+				ancestor_conflict->name_collision = 1;
+		}
+
+		if (our_conflict && our_conflict != ancestor_conflict &&
+			their_conflict && their_conflict != ancestor_conflict)
+			ancestor_conflict->one_to_two = 1;
+	}
+
+	git_vector_remove_matching(
+		&data->update_conflicts, checkout_conflictdata_empty, NULL);
+
+done:
+	return error;
+}
+
+static int checkout_conflicts_mark_directoryfile(
+	checkout_data *data)
+{
+	git_index *index;
+	checkout_conflictdata *conflict;
+	const git_index_entry *entry;
+	size_t i, j, len;
+	const char *path;
+	int prefixed, error = 0;
+
+	if ((index = git_iterator_index(data->target)) == NULL)
+		return 0;
+
+	len = git_index_entrycount(index);
+
+	/* Find d/f conflicts */
+	git_vector_foreach(&data->update_conflicts, i, conflict) {
+		if ((conflict->ours && conflict->theirs) ||
+			(!conflict->ours && !conflict->theirs))
+			continue;
+
+		path = conflict->ours ?
+			conflict->ours->path : conflict->theirs->path;
+
+		if ((error = git_index_find(&j, index, path)) < 0) {
+			if (error == GIT_ENOTFOUND)
+				giterr_set(GITERR_INDEX,
+					"index inconsistency, could not find entry for expected conflict '%s'", path);
+
+			goto done;
+		}
+
+		for (; j < len; j++) {
+			if ((entry = git_index_get_byindex(index, j)) == NULL) {
+				giterr_set(GITERR_INDEX,
+					"index inconsistency, truncated index while loading expected conflict '%s'", path);
+				error = -1;
+				goto done;
+			}
+
+			prefixed = git_path_equal_or_prefixed(path, entry->path, NULL);
+
+			if (prefixed == GIT_PATH_EQUAL)
+				continue;
+
+			if (prefixed == GIT_PATH_PREFIX)
+				conflict->directoryfile = 1;
+
+			break;
+		}
+	}
+
+done:
+	return error;
+}
+
+static int checkout_get_update_conflicts(
+	checkout_data *data,
+	git_iterator *workdir,
+	git_vector *pathspec)
+{
+	int error = 0;
+
+	if (data->strategy & GIT_CHECKOUT_SKIP_UNMERGED)
+		return 0;
+
+	if ((error = checkout_conflicts_load(data, workdir, pathspec)) < 0 ||
+		(error = checkout_conflicts_coalesce_renames(data)) < 0 ||
+		(error = checkout_conflicts_mark_directoryfile(data)) < 0)
+		goto done;
+
+done:
+	return error;
+}
+
+static int checkout_conflict_append_remove(
+	const git_index_entry *ancestor,
+	const git_index_entry *ours,
+	const git_index_entry *theirs,
+	void *payload)
+{
+	checkout_data *data = payload;
+	const char *name;
+
+	assert(ancestor || ours || theirs);
+
+	if (ancestor)
+		name = git__strdup(ancestor->path);
+	else if (ours)
+		name = git__strdup(ours->path);
+	else if (theirs)
+		name = git__strdup(theirs->path);
+	else
+		abort();
+
+	GITERR_CHECK_ALLOC(name);
+
+	return git_vector_insert(&data->remove_conflicts, (char *)name);
+}
+
+static int checkout_get_remove_conflicts(
+	checkout_data *data,
+	git_iterator *workdir,
+	git_vector *pathspec)
+{
+	if ((data->strategy & GIT_CHECKOUT_DONT_UPDATE_INDEX) != 0)
+		return 0;
+
+	return checkout_conflicts_foreach(data, data->index, workdir, pathspec, checkout_conflict_append_remove, data);
+}
+
+static int checkout_verify_paths(
+	git_repository *repo,
+	int action,
+	git_diff_delta *delta)
+{
+	unsigned int flags = GIT_PATH_REJECT_WORKDIR_DEFAULTS;
+
+	if (action & CHECKOUT_ACTION__REMOVE) {
+		if (!git_path_isvalid(repo, delta->old_file.path, delta->old_file.mode, flags)) {
+			giterr_set(GITERR_CHECKOUT, "cannot remove invalid path '%s'", delta->old_file.path);
+			return -1;
+		}
+	}
+
+	if (action & ~CHECKOUT_ACTION__REMOVE) {
+		if (!git_path_isvalid(repo, delta->new_file.path, delta->new_file.mode, flags)) {
+			giterr_set(GITERR_CHECKOUT, "cannot checkout to invalid path '%s'", delta->new_file.path);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+static int checkout_get_actions(
+	uint32_t **actions_ptr,
+	size_t **counts_ptr,
+	checkout_data *data,
+	git_iterator *workdir)
+{
+	int error = 0, act;
+	const git_index_entry *wditem;
+	git_vector pathspec = GIT_VECTOR_INIT, *deltas;
+	git_pool pathpool;
+	git_diff_delta *delta;
+	size_t i, *counts = NULL;
+	uint32_t *actions = NULL;
+
+	git_pool_init(&pathpool, 1);
+
+	if (data->opts.paths.count > 0 &&
+		git_pathspec__vinit(&pathspec, &data->opts.paths, &pathpool) < 0)
+		return -1;
+
+	if ((error = git_iterator_current(&wditem, workdir)) < 0 &&
+		error != GIT_ITEROVER)
+		goto fail;
+
+	deltas = &data->diff->deltas;
+
+	*counts_ptr = counts = git__calloc(CHECKOUT_ACTION__MAX+1, sizeof(size_t));
+	*actions_ptr = actions = git__calloc(
+		deltas->length ? deltas->length : 1, sizeof(uint32_t));
+	if (!counts || !actions) {
+		error = -1;
+		goto fail;
+	}
+
+	git_vector_foreach(deltas, i, delta) {
+		if ((error = checkout_action(&act, data, delta, workdir, &wditem, &pathspec)) == 0)
+			error = checkout_verify_paths(data->repo, act, delta);
+
+		if (error != 0)
+			goto fail;
+
+		actions[i] = act;
+
+		if (act & CHECKOUT_ACTION__REMOVE)
+			counts[CHECKOUT_ACTION__REMOVE]++;
+		if (act & CHECKOUT_ACTION__UPDATE_BLOB)
+			counts[CHECKOUT_ACTION__UPDATE_BLOB]++;
+		if (act & CHECKOUT_ACTION__UPDATE_SUBMODULE)
+			counts[CHECKOUT_ACTION__UPDATE_SUBMODULE]++;
+		if (act & CHECKOUT_ACTION__CONFLICT)
+			counts[CHECKOUT_ACTION__CONFLICT]++;
+	}
+
+	error = checkout_remaining_wd_items(data, workdir, wditem, &pathspec);
+	if (error)
+		goto fail;
+
+	counts[CHECKOUT_ACTION__REMOVE] += data->removes.length;
+
+	if (counts[CHECKOUT_ACTION__CONFLICT] > 0 &&
+		(data->strategy & GIT_CHECKOUT_ALLOW_CONFLICTS) == 0)
+	{
+		giterr_set(GITERR_CHECKOUT, "%"PRIuZ" %s checkout",
+			counts[CHECKOUT_ACTION__CONFLICT],
+			counts[CHECKOUT_ACTION__CONFLICT] == 1 ?
+			"conflict prevents" : "conflicts prevent");
+		error = GIT_ECONFLICT;
+		goto fail;
+	}
+
+
+	if ((error = checkout_get_remove_conflicts(data, workdir, &pathspec)) < 0 ||
+		(error = checkout_get_update_conflicts(data, workdir, &pathspec)) < 0)
+		goto fail;
+
+	counts[CHECKOUT_ACTION__REMOVE_CONFLICT] = git_vector_length(&data->remove_conflicts);
+	counts[CHECKOUT_ACTION__UPDATE_CONFLICT] = git_vector_length(&data->update_conflicts);
+
+	git_pathspec__vfree(&pathspec);
+	git_pool_clear(&pathpool);
+
+	return 0;
+
+fail:
+	*counts_ptr = NULL;
+	git__free(counts);
+	*actions_ptr = NULL;
+	git__free(actions);
+
+	git_pathspec__vfree(&pathspec);
+	git_pool_clear(&pathpool);
+
+	return error;
+}
+
+static bool should_remove_existing(checkout_data *data)
+{
+	int ignorecase;
+
+	if (git_repository__cvar(&ignorecase, data->repo, GIT_CVAR_IGNORECASE) < 0) {
+		ignorecase = 0;
+	}
+
+	return (ignorecase &&
+		(data->strategy & GIT_CHECKOUT_DONT_REMOVE_EXISTING) == 0);
+}
+
+#define MKDIR_NORMAL \
+	GIT_MKDIR_PATH | GIT_MKDIR_VERIFY_DIR
+#define MKDIR_REMOVE_EXISTING \
+	MKDIR_NORMAL | GIT_MKDIR_REMOVE_FILES | GIT_MKDIR_REMOVE_SYMLINKS
+
+static int checkout_mkdir(
+	checkout_data *data,
+	const char *path,
+	const char *base,
+	mode_t mode,
+	unsigned int flags)
+{
+	struct git_futils_mkdir_options mkdir_opts = {0};
+	int error;
+
+	mkdir_opts.dir_map = data->mkdir_map;
+	mkdir_opts.pool = &data->pool;
+
+	error = git_futils_mkdir_relative(
+		path, base, mode, flags, &mkdir_opts);
+
+	data->perfdata.mkdir_calls += mkdir_opts.perfdata.mkdir_calls;
+	data->perfdata.stat_calls += mkdir_opts.perfdata.stat_calls;
+	data->perfdata.chmod_calls += mkdir_opts.perfdata.chmod_calls;
+
+	return error;
+}
+
+static int mkpath2file(
+	checkout_data *data, const char *path, unsigned int mode)
+{
+	struct stat st;
+	bool remove_existing = should_remove_existing(data);
+	unsigned int flags =
+		(remove_existing ? MKDIR_REMOVE_EXISTING : MKDIR_NORMAL) |
+		GIT_MKDIR_SKIP_LAST;
+	int error;
+
+	if ((error = checkout_mkdir(
+			data, path, data->opts.target_directory, mode, flags)) < 0)
+		return error;
+
+	if (remove_existing) {
+		data->perfdata.stat_calls++;
+
+		if (p_lstat(path, &st) == 0) {
+
+			/* Some file, symlink or folder already exists at this name.
+			 * We would have removed it in remove_the_old unless we're on
+			 * a case inensitive filesystem (or the user has asked us not
+			 * to).  Remove the similarly named file to write the new.
+			 */
+			error = git_futils_rmdir_r(path, NULL, GIT_RMDIR_REMOVE_FILES);
+		} else if (errno != ENOENT) {
+			giterr_set(GITERR_OS, "failed to stat '%s'", path);
+			return GIT_EEXISTS;
+		} else {
+			giterr_clear();
+		}
+	}
+
+	return error;
+}
+
+struct checkout_stream {
+	git_writestream base;
+	const char *path;
+	int fd;
+	int open;
+};
+
+static int checkout_stream_write(
+	git_writestream *s, const char *buffer, size_t len)
+{
+	struct checkout_stream *stream = (struct checkout_stream *)s;
+	int ret;
+
+	if ((ret = p_write(stream->fd, buffer, len)) < 0)
+		giterr_set(GITERR_OS, "could not write to '%s'", stream->path);
+
+	return ret;
+}
+
+static int checkout_stream_close(git_writestream *s)
+{
+	struct checkout_stream *stream = (struct checkout_stream *)s;
+	assert(stream && stream->open);
+
+	stream->open = 0;
+	return p_close(stream->fd);
+}
+
+static void checkout_stream_free(git_writestream *s)
+{
+	GIT_UNUSED(s);
+}
+
+static int blob_content_to_file(
+	checkout_data *data,
+	struct stat *st,
+	git_blob *blob,
+	const char *path,
+	const char *hint_path,
+	mode_t entry_filemode)
+{
+	int flags = data->opts.file_open_flags;
+	mode_t file_mode = data->opts.file_mode ?
+		data->opts.file_mode : entry_filemode;
+	git_filter_options filter_opts = GIT_FILTER_OPTIONS_INIT;
+	struct checkout_stream writer;
+	mode_t mode;
+	git_filter_list *fl = NULL;
+	int fd;
+	int error = 0;
+
+	if (hint_path == NULL)
+		hint_path = path;
+
+	if ((error = mkpath2file(data, path, data->opts.dir_mode)) < 0)
+		return error;
+
+	if (flags <= 0)
+		flags = O_CREAT | O_TRUNC | O_WRONLY;
+	if (!(mode = file_mode))
+		mode = GIT_FILEMODE_BLOB;
+
+	if ((fd = p_open(path, flags, mode)) < 0) {
+		giterr_set(GITERR_OS, "could not open '%s' for writing", path);
+		return fd;
+	}
+
+	filter_opts.attr_session = &data->attr_session;
+	filter_opts.temp_buf = &data->tmp;
+
+	if (!data->opts.disable_filters &&
+		(error = git_filter_list__load_ext(
+			&fl, data->repo, blob, hint_path,
+			GIT_FILTER_TO_WORKTREE, &filter_opts))) {
+		p_close(fd);
+		return error;
+	}
+
+	/* setup the writer */
+	memset(&writer, 0, sizeof(struct checkout_stream));
+	writer.base.write = checkout_stream_write;
+	writer.base.close = checkout_stream_close;
+	writer.base.free = checkout_stream_free;
+	writer.path = path;
+	writer.fd = fd;
+	writer.open = 1;
+
+	error = git_filter_list_stream_blob(fl, blob, &writer.base);
+
+	assert(writer.open == 0);
+
+	git_filter_list_free(fl);
+
+	if (error < 0)
+		return error;
+
+	if (st) {
+		data->perfdata.stat_calls++;
+
+		if ((error = p_stat(path, st)) < 0) {
+			giterr_set(GITERR_OS, "failed to stat '%s'", path);
+			return error;
+		}
+
+		st->st_mode = entry_filemode;
+	}
+
+	return 0;
+}
+
+static int blob_content_to_link(
+	checkout_data *data,
+	struct stat *st,
+	git_blob *blob,
+	const char *path)
+{
+	git_buf linktarget = GIT_BUF_INIT;
+	int error;
+
+	if ((error = mkpath2file(data, path, data->opts.dir_mode)) < 0)
+		return error;
+
+	if ((error = git_blob__getbuf(&linktarget, blob)) < 0)
+		return error;
+
+	if (data->can_symlink) {
+		if ((error = p_symlink(git_buf_cstr(&linktarget), path)) < 0)
+			giterr_set(GITERR_OS, "could not create symlink %s", path);
+	} else {
+		error = git_futils_fake_symlink(git_buf_cstr(&linktarget), path);
+	}
+
+	if (!error) {
+		data->perfdata.stat_calls++;
+
+		if ((error = p_lstat(path, st)) < 0)
+			giterr_set(GITERR_CHECKOUT, "could not stat symlink %s", path);
+
+		st->st_mode = GIT_FILEMODE_LINK;
+	}
+
+	git_buf_free(&linktarget);
+
+	return error;
+}
+
+static int checkout_update_index(
+	checkout_data *data,
+	const git_diff_file *file,
+	struct stat *st)
+{
+	git_index_entry entry;
+
+	if (!data->index)
+		return 0;
+
+	memset(&entry, 0, sizeof(entry));
+	entry.path = (char *)file->path; /* cast to prevent warning */
+	git_index_entry__init_from_stat(&entry, st, true);
+	git_oid_cpy(&entry.id, &file->id);
+
+	return git_index_add(data->index, &entry);
+}
+
+static int checkout_submodule_update_index(
+	checkout_data *data,
+	const git_diff_file *file)
+{
+	git_buf *fullpath;
+	struct stat st;
+
+	/* update the index unless prevented */
+	if ((data->strategy & GIT_CHECKOUT_DONT_UPDATE_INDEX) != 0)
+		return 0;
+
+	if (checkout_target_fullpath(&fullpath, data, file->path) < 0)
+		return -1;
+
+	data->perfdata.stat_calls++;
+	if (p_stat(fullpath->ptr, &st) < 0) {
+		giterr_set(
+			GITERR_CHECKOUT, "could not stat submodule %s\n", file->path);
+		return GIT_ENOTFOUND;
+	}
+
+	st.st_mode = GIT_FILEMODE_COMMIT;
+
+	return checkout_update_index(data, file, &st);
+}
+
+static int checkout_submodule(
+	checkout_data *data,
+	const git_diff_file *file)
+{
+	bool remove_existing = should_remove_existing(data);
+	int error = 0;
+
+	/* Until submodules are supported, UPDATE_ONLY means do nothing here */
+	if ((data->strategy & GIT_CHECKOUT_UPDATE_ONLY) != 0)
+		return 0;
+
+	if ((error = checkout_mkdir(
+			data,
+			file->path, data->opts.target_directory, data->opts.dir_mode,
+			remove_existing ? MKDIR_REMOVE_EXISTING : MKDIR_NORMAL)) < 0)
+		return error;
+
+	if ((error = git_submodule_lookup(NULL, data->repo, file->path)) < 0) {
+		/* I've observed repos with submodules in the tree that do not
+		 * have a .gitmodules - core Git just makes an empty directory
+		 */
+		if (error == GIT_ENOTFOUND) {
+			giterr_clear();
+			return checkout_submodule_update_index(data, file);
+		}
+
+		return error;
+	}
+
+	/* TODO: Support checkout_strategy options.  Two circumstances:
+	 * 1 - submodule already checked out, but we need to move the HEAD
+	 *     to the new OID, or
+	 * 2 - submodule not checked out and we should recursively check it out
+	 *
+	 * Checkout will not execute a pull on the submodule, but a clone
+	 * command should probably be able to.  Do we need a submodule callback?
+	 */
+
+	return checkout_submodule_update_index(data, file);
+}
+
+static void report_progress(
+	checkout_data *data,
+	const char *path)
+{
+	if (data->opts.progress_cb)
+		data->opts.progress_cb(
+			path, data->completed_steps, data->total_steps,
+			data->opts.progress_payload);
+}
+
+static int checkout_safe_for_update_only(
+	checkout_data *data, const char *path, mode_t expected_mode)
+{
+	struct stat st;
+
+	data->perfdata.stat_calls++;
+
+	if (p_lstat(path, &st) < 0) {
+		/* if doesn't exist, then no error and no update */
+		if (errno == ENOENT || errno == ENOTDIR)
+			return 0;
+
+		/* otherwise, stat error and no update */
+		giterr_set(GITERR_OS, "failed to stat '%s'", path);
+		return -1;
+	}
+
+	/* only safe for update if this is the same type of file */
+	if ((st.st_mode & ~0777) == (expected_mode & ~0777))
+		return 1;
+
+	return 0;
+}
+
+static int checkout_write_content(
+	checkout_data *data,
+	const git_oid *oid,
+	const char *full_path,
+	const char *hint_path,
+	unsigned int mode,
+	struct stat *st)
+{
+	int error = 0;
+	git_blob *blob;
+
+	if ((error = git_blob_lookup(&blob, data->repo, oid)) < 0)
+		return error;
+
+	if (S_ISLNK(mode))
+		error = blob_content_to_link(data, st, blob, full_path);
+	else
+		error = blob_content_to_file(data, st, blob, full_path, hint_path, mode);
+
+	git_blob_free(blob);
+
+	/* if we try to create the blob and an existing directory blocks it from
+	 * being written, then there must have been a typechange conflict in a
+	 * parent directory - suppress the error and try to continue.
+	 */
+	if ((data->strategy & GIT_CHECKOUT_ALLOW_CONFLICTS) != 0 &&
+		(error == GIT_ENOTFOUND || error == GIT_EEXISTS))
+	{
+		giterr_clear();
+		error = 0;
+	}
+
+	return error;
+}
+
+static int checkout_blob(
+	checkout_data *data,
+	const git_diff_file *file)
+{
+	git_buf *fullpath;
+	struct stat st;
+	int error = 0;
+
+	if (checkout_target_fullpath(&fullpath, data, file->path) < 0)
+		return -1;
+
+	if ((data->strategy & GIT_CHECKOUT_UPDATE_ONLY) != 0) {
+		int rval = checkout_safe_for_update_only(
+			data, fullpath->ptr, file->mode);
+
+		if (rval <= 0)
+			return rval;
+	}
+
+	error = checkout_write_content(
+		data, &file->id, fullpath->ptr, NULL, file->mode, &st);
+
+	/* update the index unless prevented */
+	if (!error && (data->strategy & GIT_CHECKOUT_DONT_UPDATE_INDEX) == 0)
+		error = checkout_update_index(data, file, &st);
+
+	/* update the submodule data if this was a new .gitmodules file */
+	if (!error && strcmp(file->path, ".gitmodules") == 0)
+		data->reload_submodules = true;
+
+	return error;
+}
+
+static int checkout_remove_the_old(
+	unsigned int *actions,
+	checkout_data *data)
+{
+	int error = 0;
+	git_diff_delta *delta;
+	const char *str;
+	size_t i;
+	git_buf *fullpath;
+	uint32_t flg = GIT_RMDIR_EMPTY_PARENTS |
+		GIT_RMDIR_REMOVE_FILES | GIT_RMDIR_REMOVE_BLOCKERS;
+
+	if (data->opts.checkout_strategy & GIT_CHECKOUT_SKIP_LOCKED_DIRECTORIES)
+		flg |= GIT_RMDIR_SKIP_NONEMPTY;
+
+	if (checkout_target_fullpath(&fullpath, data, NULL) < 0)
+		return -1;
+
+	git_vector_foreach(&data->diff->deltas, i, delta) {
+		if (actions[i] & CHECKOUT_ACTION__REMOVE) {
+			error = git_futils_rmdir_r(
+				delta->old_file.path, fullpath->ptr, flg);
+
+			if (error < 0)
+				return error;
+
+			data->completed_steps++;
+			report_progress(data, delta->old_file.path);
+
+			if ((actions[i] & CHECKOUT_ACTION__UPDATE_BLOB) == 0 &&
+				(data->strategy & GIT_CHECKOUT_DONT_UPDATE_INDEX) == 0 &&
+				data->index != NULL)
+			{
+				(void)git_index_remove(data->index, delta->old_file.path, 0);
+			}
+		}
+	}
+
+	git_vector_foreach(&data->removes, i, str) {
+		error = git_futils_rmdir_r(str, fullpath->ptr, flg);
+		if (error < 0)
+			return error;
+
+		data->completed_steps++;
+		report_progress(data, str);
+
+		if ((data->strategy & GIT_CHECKOUT_DONT_UPDATE_INDEX) == 0 &&
+			data->index != NULL)
+		{
+			if (str[strlen(str) - 1] == '/')
+				(void)git_index_remove_directory(data->index, str, 0);
+			else
+				(void)git_index_remove(data->index, str, 0);
+		}
+	}
+
+	return 0;
+}
+
+static int checkout_deferred_remove(git_repository *repo, const char *path)
+{
+#if 0
+	int error = git_futils_rmdir_r(
+		path, data->opts.target_directory, GIT_RMDIR_EMPTY_PARENTS);
+
+	if (error == GIT_ENOTFOUND) {
+		error = 0;
+		giterr_clear();
+	}
+
+	return error;
+#else
+	GIT_UNUSED(repo);
+	GIT_UNUSED(path);
+	assert(false);
+	return 0;
+#endif
+}
+
+static int checkout_create_the_new(
+	unsigned int *actions,
+	checkout_data *data)
+{
+	int error = 0;
+	git_diff_delta *delta;
+	size_t i;
+
+	git_vector_foreach(&data->diff->deltas, i, delta) {
+		if (actions[i] & CHECKOUT_ACTION__DEFER_REMOVE) {
+			/* this had a blocker directory that should only be removed iff
+			 * all of the contents of the directory were safely removed
+			 */
+			if ((error = checkout_deferred_remove(
+					data->repo, delta->old_file.path)) < 0)
+				return error;
+		}
+
+		if (actions[i] & CHECKOUT_ACTION__UPDATE_BLOB) {
+			error = checkout_blob(data, &delta->new_file);
+			if (error < 0)
+				return error;
+
+			data->completed_steps++;
+			report_progress(data, delta->new_file.path);
+		}
+	}
+
+	return 0;
+}
+
+static int checkout_create_submodules(
+	unsigned int *actions,
+	checkout_data *data)
+{
+	int error = 0;
+	git_diff_delta *delta;
+	size_t i;
+
+	git_vector_foreach(&data->diff->deltas, i, delta) {
+		if (actions[i] & CHECKOUT_ACTION__DEFER_REMOVE) {
+			/* this has a blocker directory that should only be removed iff
+			 * all of the contents of the directory were safely removed
+			 */
+			if ((error = checkout_deferred_remove(
+					data->repo, delta->old_file.path)) < 0)
+				return error;
+		}
+
+		if (actions[i] & CHECKOUT_ACTION__UPDATE_SUBMODULE) {
+			int error = checkout_submodule(data, &delta->new_file);
+			if (error < 0)
+				return error;
+
+			data->completed_steps++;
+			report_progress(data, delta->new_file.path);
+		}
+	}
+
+	return 0;
+}
+
+static int checkout_lookup_head_tree(git_tree **out, git_repository *repo)
+{
+	int error = 0;
+	git_reference *ref = NULL;
+	git_object *head;
+
+	if (!(error = git_repository_head(&ref, repo)) &&
+		!(error = git_reference_peel(&head, ref, GIT_OBJ_TREE)))
+		*out = (git_tree *)head;
+
+	git_reference_free(ref);
+
+	return error;
+}
+
+
+static int conflict_entry_name(
+	git_buf *out,
+	const char *side_name,
+	const char *filename)
+{
+	if (git_buf_puts(out, side_name) < 0 ||
+		git_buf_putc(out, ':') < 0 ||
+		git_buf_puts(out, filename) < 0)
+		return -1;
+
+	return 0;
+}
+
+static int checkout_path_suffixed(git_buf *path, const char *suffix)
+{
+	size_t path_len;
+	int i = 0, error = 0;
+
+	if ((error = git_buf_putc(path, '~')) < 0 || (error = git_buf_puts(path, suffix)) < 0)
+		return -1;
+
+	path_len = git_buf_len(path);
+
+	while (git_path_exists(git_buf_cstr(path)) && i < INT_MAX) {
+		git_buf_truncate(path, path_len);
+
+		if ((error = git_buf_putc(path, '_')) < 0 ||
+			(error = git_buf_printf(path, "%d", i)) < 0)
+			return error;
+
+		i++;
+	}
+
+	if (i == INT_MAX) {
+		git_buf_truncate(path, path_len);
+
+		giterr_set(GITERR_CHECKOUT, "could not write '%s': working directory file exists", path->ptr);
+		return GIT_EEXISTS;
+	}
+
+	return 0;
+}
+
+static int checkout_write_entry(
+	checkout_data *data,
+	checkout_conflictdata *conflict,
+	const git_index_entry *side)
+{
+	const char *hint_path = NULL, *suffix;
+	git_buf *fullpath;
+	struct stat st;
+	int error;
+
+	assert (side == conflict->ours || side == conflict->theirs);
+
+	if (checkout_target_fullpath(&fullpath, data, side->path) < 0)
+		return -1;
+
+	if ((conflict->name_collision || conflict->directoryfile) &&
+		(data->strategy & GIT_CHECKOUT_USE_OURS) == 0 &&
+		(data->strategy & GIT_CHECKOUT_USE_THEIRS) == 0) {
+
+		if (side == conflict->ours)
+			suffix = data->opts.our_label ? data->opts.our_label :
+				"ours";
+		else
+			suffix = data->opts.their_label ? data->opts.their_label :
+				"theirs";
+
+		if (checkout_path_suffixed(fullpath, suffix) < 0)
+			return -1;
+
+		hint_path = side->path;
+	}
+
+	if ((data->strategy & GIT_CHECKOUT_UPDATE_ONLY) != 0 &&
+		(error = checkout_safe_for_update_only(data, fullpath->ptr, side->mode)) <= 0)
+		return error;
+
+	if (!S_ISGITLINK(side->mode))
+		return checkout_write_content(data,
+					      &side->id, fullpath->ptr, hint_path, side->mode, &st);
+
+	return 0;
+}
+
+static int checkout_write_entries(
+	checkout_data *data,
+	checkout_conflictdata *conflict)
+{
+	int error = 0;
+
+	if ((error = checkout_write_entry(data, conflict, conflict->ours)) >= 0)
+		error = checkout_write_entry(data, conflict, conflict->theirs);
+
+	return error;
+}
+
+static int checkout_merge_path(
+	git_buf *out,
+	checkout_data *data,
+	checkout_conflictdata *conflict,
+	git_merge_file_result *result)
+{
+	const char *our_label_raw, *their_label_raw, *suffix;
+	int error = 0;
+
+	if ((error = git_buf_joinpath(out, git_repository_workdir(data->repo), result->path)) < 0)
+		return error;
+
+	/* Most conflicts simply use the filename in the index */
+	if (!conflict->name_collision)
+		return 0;
+
+	/* Rename 2->1 conflicts need the branch name appended */
+	our_label_raw = data->opts.our_label ? data->opts.our_label : "ours";
+	their_label_raw = data->opts.their_label ? data->opts.their_label : "theirs";
+	suffix = strcmp(result->path, conflict->ours->path) == 0 ? our_label_raw : their_label_raw;
+
+	if ((error = checkout_path_suffixed(out, suffix)) < 0)
+		return error;
+
+	return 0;
+}
+
+static int checkout_write_merge(
+	checkout_data *data,
+	checkout_conflictdata *conflict)
+{
+	git_buf our_label = GIT_BUF_INIT, their_label = GIT_BUF_INIT,
+		path_suffixed = GIT_BUF_INIT, path_workdir = GIT_BUF_INIT,
+		in_data = GIT_BUF_INIT, out_data = GIT_BUF_INIT;
+	git_merge_file_options opts = GIT_MERGE_FILE_OPTIONS_INIT;
+	git_merge_file_result result = {0};
+	git_filebuf output = GIT_FILEBUF_INIT;
+	git_filter_list *fl = NULL;
+	git_filter_options filter_opts = GIT_FILTER_OPTIONS_INIT;
+	int error = 0;
+
+	if (data->opts.checkout_strategy & GIT_CHECKOUT_CONFLICT_STYLE_DIFF3)
+		opts.flags |= GIT_MERGE_FILE_STYLE_DIFF3;
+
+	opts.ancestor_label = data->opts.ancestor_label ?
+		data->opts.ancestor_label : "ancestor";
+	opts.our_label = data->opts.our_label ?
+		data->opts.our_label : "ours";
+	opts.their_label = data->opts.their_label ?
+		data->opts.their_label : "theirs";
+
+	/* If all the paths are identical, decorate the diff3 file with the branch
+	 * names.  Otherwise, append branch_name:path.
+	 */
+	if (conflict->ours && conflict->theirs &&
+		strcmp(conflict->ours->path, conflict->theirs->path) != 0) {
+
+		if ((error = conflict_entry_name(
+			&our_label, opts.our_label, conflict->ours->path)) < 0 ||
+			(error = conflict_entry_name(
+			&their_label, opts.their_label, conflict->theirs->path)) < 0)
+			goto done;
+
+		opts.our_label = git_buf_cstr(&our_label);
+		opts.their_label = git_buf_cstr(&their_label);
+	}
+
+	if ((error = git_merge_file_from_index(&result, data->repo,
+		conflict->ancestor, conflict->ours, conflict->theirs, &opts)) < 0)
+		goto done;
+
+	if (result.path == NULL || result.mode == 0) {
+		giterr_set(GITERR_CHECKOUT, "could not merge contents of file");
+		error = GIT_ECONFLICT;
+		goto done;
+	}
+
+	if ((error = checkout_merge_path(&path_workdir, data, conflict, &result)) < 0)
+		goto done;
+
+	if ((data->strategy & GIT_CHECKOUT_UPDATE_ONLY) != 0 &&
+		(error = checkout_safe_for_update_only(data, git_buf_cstr(&path_workdir), result.mode)) <= 0)
+		goto done;
+
+	if (!data->opts.disable_filters) {
+		in_data.ptr = (char *)result.ptr;
+		in_data.size = result.len;
+
+		filter_opts.attr_session = &data->attr_session;
+		filter_opts.temp_buf = &data->tmp;
+
+		if ((error = git_filter_list__load_ext(
+				&fl, data->repo, NULL, git_buf_cstr(&path_workdir),
+				GIT_FILTER_TO_WORKTREE, &filter_opts)) < 0 ||
+			(error = git_filter_list_apply_to_data(&out_data, fl, &in_data)) < 0)
+			goto done;
+	} else {
+		out_data.ptr = (char *)result.ptr;
+		out_data.size = result.len;
+	}
+
+	if ((error = mkpath2file(data, path_workdir.ptr, data->opts.dir_mode)) < 0 ||
+		(error = git_filebuf_open(&output, git_buf_cstr(&path_workdir), GIT_FILEBUF_DO_NOT_BUFFER, result.mode)) < 0 ||
+		(error = git_filebuf_write(&output, out_data.ptr, out_data.size)) < 0 ||
+		(error = git_filebuf_commit(&output)) < 0)
+		goto done;
+
+done:
+	git_filter_list_free(fl);
+
+	git_buf_free(&out_data);
+	git_buf_free(&our_label);
+	git_buf_free(&their_label);
+
+	git_merge_file_result_free(&result);
+	git_buf_free(&path_workdir);
+	git_buf_free(&path_suffixed);
+
+	return error;
+}
+
+static int checkout_conflict_add(
+	checkout_data *data,
+	const git_index_entry *conflict)
+{
+	int error = git_index_remove(data->index, conflict->path, 0);
+
+	if (error == GIT_ENOTFOUND)
+		giterr_clear();
+	else if (error < 0)
+		return error;
+
+	return git_index_add(data->index, conflict);
+}
+
+static int checkout_conflict_update_index(
+	checkout_data *data,
+	checkout_conflictdata *conflict)
+{
+	int error = 0;
+
+	if (conflict->ancestor)
+		error = checkout_conflict_add(data, conflict->ancestor);
+
+	if (!error && conflict->ours)
+		error = checkout_conflict_add(data, conflict->ours);
+
+	if (!error && conflict->theirs)
+		error = checkout_conflict_add(data, conflict->theirs);
+
+	return error;
+}
+
+static int checkout_create_conflicts(checkout_data *data)
+{
+	checkout_conflictdata *conflict;
+	size_t i;
+	int error = 0;
+
+	git_vector_foreach(&data->update_conflicts, i, conflict) {
+
+		/* Both deleted: nothing to do */
+		if (conflict->ours == NULL && conflict->theirs == NULL)
+			error = 0;
+
+		else if ((data->strategy & GIT_CHECKOUT_USE_OURS) &&
+			conflict->ours)
+			error = checkout_write_entry(data, conflict, conflict->ours);
+		else if ((data->strategy & GIT_CHECKOUT_USE_THEIRS) &&
+			conflict->theirs)
+			error = checkout_write_entry(data, conflict, conflict->theirs);
+
+		/* Ignore the other side of name collisions. */
+		else if ((data->strategy & GIT_CHECKOUT_USE_OURS) &&
+			!conflict->ours && conflict->name_collision)
+			error = 0;
+		else if ((data->strategy & GIT_CHECKOUT_USE_THEIRS) &&
+			!conflict->theirs && conflict->name_collision)
+			error = 0;
+
+		/* For modify/delete, name collisions and d/f conflicts, write
+		 * the file (potentially with the name mangled.
+		 */
+		else if (conflict->ours != NULL && conflict->theirs == NULL)
+			error = checkout_write_entry(data, conflict, conflict->ours);
+		else if (conflict->ours == NULL && conflict->theirs != NULL)
+			error = checkout_write_entry(data, conflict, conflict->theirs);
+
+		/* Add/add conflicts and rename 1->2 conflicts, write the
+		 * ours/theirs sides (potentially name mangled).
+		 */
+		else if (conflict->one_to_two)
+			error = checkout_write_entries(data, conflict);
+
+		/* If all sides are links, write the ours side */
+		else if (S_ISLNK(conflict->ours->mode) &&
+			S_ISLNK(conflict->theirs->mode))
+			error = checkout_write_entry(data, conflict, conflict->ours);
+		/* Link/file conflicts, write the file side */
+		else if (S_ISLNK(conflict->ours->mode))
+			error = checkout_write_entry(data, conflict, conflict->theirs);
+		else if (S_ISLNK(conflict->theirs->mode))
+			error = checkout_write_entry(data, conflict, conflict->ours);
+
+		/* If any side is a gitlink, do nothing. */
+		else if (conflict->submodule)
+			error = 0;
+
+		/* If any side is binary, write the ours side */
+		else if (conflict->binary)
+			error = checkout_write_entry(data, conflict, conflict->ours);
+
+		else if (!error)
+			error = checkout_write_merge(data, conflict);
+
+		/* Update the index extensions (REUC and NAME) if we're checking
+		 * out a different index. (Otherwise just leave them there.)
+		 */
+		if (!error && (data->strategy & GIT_CHECKOUT_DONT_UPDATE_INDEX) == 0)
+			error = checkout_conflict_update_index(data, conflict);
+
+		if (error)
+			break;
+
+		data->completed_steps++;
+		report_progress(data,
+			conflict->ours ? conflict->ours->path :
+			(conflict->theirs ? conflict->theirs->path : conflict->ancestor->path));
+	}
+
+	return error;
+}
+
+static int checkout_remove_conflicts(checkout_data *data)
+{
+	const char *conflict;
+	size_t i;
+
+	git_vector_foreach(&data->remove_conflicts, i, conflict) {
+		if (git_index_conflict_remove(data->index, conflict) < 0)
+			return -1;
+
+		data->completed_steps++;
+	}
+
+	return 0;
+}
+
+static int checkout_extensions_update_index(checkout_data *data)
+{
+	const git_index_reuc_entry *reuc_entry;
+	const git_index_name_entry *name_entry;
+	size_t i;
+	int error = 0;
+
+	if ((data->strategy & GIT_CHECKOUT_UPDATE_ONLY) != 0)
+		return 0;
+
+	if (data->update_reuc) {
+		git_vector_foreach(data->update_reuc, i, reuc_entry) {
+			if ((error = git_index_reuc_add(data->index, reuc_entry->path,
+				reuc_entry->mode[0], &reuc_entry->oid[0],
+				reuc_entry->mode[1], &reuc_entry->oid[1],
+				reuc_entry->mode[2], &reuc_entry->oid[2])) < 0)
+				goto done;
+		}
+	}
+
+	if (data->update_names) {
+		git_vector_foreach(data->update_names, i, name_entry) {
+			if ((error = git_index_name_add(data->index, name_entry->ancestor,
+				name_entry->ours, name_entry->theirs)) < 0)
+				goto done;
+		}
+	}
+
+done:
+	return error;
+}
+
+static void checkout_data_clear(checkout_data *data)
+{
+	if (data->opts_free_baseline) {
+		git_tree_free(data->opts.baseline);
+		data->opts.baseline = NULL;
+	}
+
+	git_vector_free(&data->removes);
+	git_pool_clear(&data->pool);
+
+	git_vector_free_deep(&data->remove_conflicts);
+	git_vector_free_deep(&data->update_conflicts);
+
+	git__free(data->pfx);
+	data->pfx = NULL;
+
+	git_buf_free(&data->target_path);
+	git_buf_free(&data->tmp);
+
+	git_index_free(data->index);
+	data->index = NULL;
+
+	git_strmap_free(data->mkdir_map);
+	data->mkdir_map = NULL;
+
+	git_attr_session__free(&data->attr_session);
+}
+
+static int checkout_data_init(
+	checkout_data *data,
+	git_iterator *target,
+	const git_checkout_options *proposed)
+{
+	int error = 0;
+	git_repository *repo = git_iterator_owner(target);
+
+	memset(data, 0, sizeof(*data));
+
+	if (!repo) {
+		giterr_set(GITERR_CHECKOUT, "cannot checkout nothing");
+		return -1;
+	}
+
+	if ((!proposed || !proposed->target_directory) &&
+		(error = git_repository__ensure_not_bare(repo, "checkout")) < 0)
+		return error;
+
+	data->repo = repo;
+	data->target = target;
+
+	GITERR_CHECK_VERSION(
+		proposed, GIT_CHECKOUT_OPTIONS_VERSION, "git_checkout_options");
+
+	if (!proposed)
+		GIT_INIT_STRUCTURE(&data->opts, GIT_CHECKOUT_OPTIONS_VERSION);
+	else
+		memmove(&data->opts, proposed, sizeof(git_checkout_options));
+
+	if (!data->opts.target_directory)
+		data->opts.target_directory = git_repository_workdir(repo);
+	else if (!git_path_isdir(data->opts.target_directory) &&
+			 (error = checkout_mkdir(data,
+				data->opts.target_directory, NULL,
+				GIT_DIR_MODE, GIT_MKDIR_VERIFY_DIR)) < 0)
+		goto cleanup;
+
+	/* refresh config and index content unless NO_REFRESH is given */
+	if ((data->opts.checkout_strategy & GIT_CHECKOUT_NO_REFRESH) == 0) {
+		git_config *cfg;
+
+		if ((error = git_repository_config__weakptr(&cfg, repo)) < 0)
+			goto cleanup;
+
+		/* Get the repository index and reload it (unless we're checking
+		 * out the index; then it has the changes we're trying to check
+		 * out and those should not be overwritten.)
+		 */
+		if ((error = git_repository_index(&data->index, data->repo)) < 0)
+			goto cleanup;
+
+		if (data->index != git_iterator_index(target)) {
+			if ((error = git_index_read(data->index, true)) < 0)
+				goto cleanup;
+
+			/* cannot checkout if unresolved conflicts exist */
+			if ((data->opts.checkout_strategy & GIT_CHECKOUT_FORCE) == 0 &&
+				git_index_has_conflicts(data->index)) {
+				error = GIT_ECONFLICT;
+				giterr_set(GITERR_CHECKOUT,
+					"unresolved conflicts exist in the index");
+				goto cleanup;
+			}
+
+			/* clean conflict data in the current index */
+			git_index_name_clear(data->index);
+			git_index_reuc_clear(data->index);
+		}
+	}
+
+	/* if you are forcing, allow all safe updates, plus recreate missing */
+	if ((data->opts.checkout_strategy & GIT_CHECKOUT_FORCE) != 0)
+		data->opts.checkout_strategy |= GIT_CHECKOUT_SAFE |
+			GIT_CHECKOUT_RECREATE_MISSING;
+
+	/* if the repository does not actually have an index file, then this
+	 * is an initial checkout (perhaps from clone), so we allow safe updates
+	 */
+	if (!data->index->on_disk &&
+		(data->opts.checkout_strategy & GIT_CHECKOUT_SAFE) != 0)
+		data->opts.checkout_strategy |= GIT_CHECKOUT_RECREATE_MISSING;
+
+	data->strategy = data->opts.checkout_strategy;
+
+	/* opts->disable_filters is false by default */
+
+	if (!data->opts.dir_mode)
+		data->opts.dir_mode = GIT_DIR_MODE;
+
+	if (!data->opts.file_open_flags)
+		data->opts.file_open_flags = O_CREAT | O_TRUNC | O_WRONLY;
+
+	data->pfx = git_pathspec_prefix(&data->opts.paths);
+
+	if ((error = git_repository__cvar(
+			 &data->can_symlink, repo, GIT_CVAR_SYMLINKS)) < 0)
+		goto cleanup;
+
+	if ((error = git_repository__cvar(
+			 &data->respect_filemode, repo, GIT_CVAR_FILEMODE)) < 0)
+		goto cleanup;
+
+	if (!data->opts.baseline && !data->opts.baseline_index) {
+		data->opts_free_baseline = true;
+		error = 0;
+
+		/* if we don't have an index, this is an initial checkout and
+		 * should be against an empty baseline
+		 */
+		if (data->index->on_disk)
+			error = checkout_lookup_head_tree(&data->opts.baseline, repo);
+
+		if (error == GIT_EUNBORNBRANCH) {
+			error = 0;
+			giterr_clear();
+		}
+
+		if (error < 0)
+			goto cleanup;
+	}
+
+	if ((data->opts.checkout_strategy &
+		(GIT_CHECKOUT_CONFLICT_STYLE_MERGE | GIT_CHECKOUT_CONFLICT_STYLE_DIFF3)) == 0) {
+		git_config_entry *conflict_style = NULL;
+		git_config *cfg = NULL;
+
+		if ((error = git_repository_config__weakptr(&cfg, repo)) < 0 ||
+			(error = git_config_get_entry(&conflict_style, cfg, "merge.conflictstyle")) < 0 ||
+			error == GIT_ENOTFOUND)
+			;
+		else if (error)
+			goto cleanup;
+		else if (strcmp(conflict_style->value, "merge") == 0)
+			data->opts.checkout_strategy |= GIT_CHECKOUT_CONFLICT_STYLE_MERGE;
+		else if (strcmp(conflict_style->value, "diff3") == 0)
+			data->opts.checkout_strategy |= GIT_CHECKOUT_CONFLICT_STYLE_DIFF3;
+		else {
+			giterr_set(GITERR_CHECKOUT, "unknown style '%s' given for 'merge.conflictstyle'",
+				conflict_style->value);
+			error = -1;
+			git_config_entry_free(conflict_style);
+			goto cleanup;
+		}
+		git_config_entry_free(conflict_style);
+	}
+
+	git_pool_init(&data->pool, 1);
+
+	if ((error = git_vector_init(&data->removes, 0, git__strcmp_cb)) < 0 ||
+		(error = git_vector_init(&data->remove_conflicts, 0, NULL)) < 0 ||
+		(error = git_vector_init(&data->update_conflicts, 0, NULL)) < 0 ||
+		(error = git_buf_puts(&data->target_path, data->opts.target_directory)) < 0 ||
+		(error = git_path_to_dir(&data->target_path)) < 0 ||
+		(error = git_strmap_alloc(&data->mkdir_map)) < 0)
+		goto cleanup;
+
+	data->target_len = git_buf_len(&data->target_path);
+
+	git_attr_session__init(&data->attr_session, data->repo);
+
+cleanup:
+	if (error < 0)
+		checkout_data_clear(data);
+
+	return error;
+}
+
+#define CHECKOUT_INDEX_DONT_WRITE_MASK \
+	(GIT_CHECKOUT_DONT_UPDATE_INDEX | GIT_CHECKOUT_DONT_WRITE_INDEX)
+
+int git_checkout_iterator(
+	git_iterator *target,
+	git_index *index,
+	const git_checkout_options *opts)
+{
+	int error = 0;
+	git_iterator *baseline = NULL, *workdir = NULL;
+	git_iterator_options baseline_opts = GIT_ITERATOR_OPTIONS_INIT,
+		workdir_opts = GIT_ITERATOR_OPTIONS_INIT;
+	checkout_data data = {0};
+	git_diff_options diff_opts = GIT_DIFF_OPTIONS_INIT;
+	uint32_t *actions = NULL;
+	size_t *counts = NULL;
+
+	/* initialize structures and options */
+	error = checkout_data_init(&data, target, opts);
+	if (error < 0)
+		return error;
+
+	diff_opts.flags =
+		GIT_DIFF_INCLUDE_UNMODIFIED |
+		GIT_DIFF_INCLUDE_UNREADABLE |
+		GIT_DIFF_INCLUDE_UNTRACKED |
+		GIT_DIFF_RECURSE_UNTRACKED_DIRS | /* needed to match baseline */
+		GIT_DIFF_INCLUDE_IGNORED |
+		GIT_DIFF_INCLUDE_TYPECHANGE |
+		GIT_DIFF_INCLUDE_TYPECHANGE_TREES |
+		GIT_DIFF_SKIP_BINARY_CHECK |
+		GIT_DIFF_INCLUDE_CASECHANGE;
+	if (data.opts.checkout_strategy & GIT_CHECKOUT_DISABLE_PATHSPEC_MATCH)
+		diff_opts.flags |= GIT_DIFF_DISABLE_PATHSPEC_MATCH;
+	if (data.opts.paths.count > 0)
+		diff_opts.pathspec = data.opts.paths;
+
+	/* set up iterators */
+
+	workdir_opts.flags = git_iterator_ignore_case(target) ?
+		GIT_ITERATOR_IGNORE_CASE : GIT_ITERATOR_DONT_IGNORE_CASE;
+	workdir_opts.flags |= GIT_ITERATOR_DONT_AUTOEXPAND;
+	workdir_opts.start = data.pfx;
+	workdir_opts.end = data.pfx;
+
+	if ((error = git_iterator_reset_range(target, data.pfx, data.pfx)) < 0 ||
+		(error = git_iterator_for_workdir_ext(
+			&workdir, data.repo, data.opts.target_directory, index, NULL,
+			&workdir_opts)) < 0)
+		goto cleanup;
+
+	baseline_opts.flags = git_iterator_ignore_case(target) ?
+		GIT_ITERATOR_IGNORE_CASE : GIT_ITERATOR_DONT_IGNORE_CASE;
+	baseline_opts.start = data.pfx;
+	baseline_opts.end = data.pfx;
+	if (opts && (opts->checkout_strategy & GIT_CHECKOUT_DISABLE_PATHSPEC_MATCH)) {
+		baseline_opts.pathlist.count = opts->paths.count;
+		baseline_opts.pathlist.strings = opts->paths.strings;
+	}
+
+	if (data.opts.baseline_index) {
+		if ((error = git_iterator_for_index(
+				&baseline, git_index_owner(data.opts.baseline_index),
+				data.opts.baseline_index, &baseline_opts)) < 0)
+			goto cleanup;
+	} else {
+		if ((error = git_iterator_for_tree(
+				&baseline, data.opts.baseline, &baseline_opts)) < 0)
+			goto cleanup;
+	}
+
+	/* Should not have case insensitivity mismatch */
+	assert(git_iterator_ignore_case(workdir) == git_iterator_ignore_case(baseline));
+
+	/* Generate baseline-to-target diff which will include an entry for
+	 * every possible update that might need to be made.
+	 */
+	if ((error = git_diff__from_iterators(
+			&data.diff, data.repo, baseline, target, &diff_opts)) < 0)
+		goto cleanup;
+
+	/* Loop through diff (and working directory iterator) building a list of
+	 * actions to be taken, plus look for conflicts and send notifications,
+	 * then loop through conflicts.
+	 */
+	if ((error = checkout_get_actions(&actions, &counts, &data, workdir)) != 0)
+		goto cleanup;
+
+	data.total_steps = counts[CHECKOUT_ACTION__REMOVE] +
+		counts[CHECKOUT_ACTION__REMOVE_CONFLICT] +
+		counts[CHECKOUT_ACTION__UPDATE_BLOB] +
+		counts[CHECKOUT_ACTION__UPDATE_SUBMODULE] +
+		counts[CHECKOUT_ACTION__UPDATE_CONFLICT];
+
+	report_progress(&data, NULL); /* establish 0 baseline */
+
+	/* To deal with some order dependencies, perform remaining checkout
+	 * in three passes: removes, then update blobs, then update submodules.
+	 */
+	if (counts[CHECKOUT_ACTION__REMOVE] > 0 &&
+		(error = checkout_remove_the_old(actions, &data)) < 0)
+		goto cleanup;
+
+	if (counts[CHECKOUT_ACTION__REMOVE_CONFLICT] > 0 &&
+		(error = checkout_remove_conflicts(&data)) < 0)
+		goto cleanup;
+
+	if (counts[CHECKOUT_ACTION__UPDATE_BLOB] > 0 &&
+		(error = checkout_create_the_new(actions, &data)) < 0)
+		goto cleanup;
+
+	if (counts[CHECKOUT_ACTION__UPDATE_SUBMODULE] > 0 &&
+		(error = checkout_create_submodules(actions, &data)) < 0)
+		goto cleanup;
+
+	if (counts[CHECKOUT_ACTION__UPDATE_CONFLICT] > 0 &&
+		(error = checkout_create_conflicts(&data)) < 0)
+		goto cleanup;
+
+	if (data.index != git_iterator_index(target) &&
+		(error = checkout_extensions_update_index(&data)) < 0)
+		goto cleanup;
+
+	assert(data.completed_steps == data.total_steps);
+
+	if (data.opts.perfdata_cb)
+		data.opts.perfdata_cb(&data.perfdata, data.opts.perfdata_payload);
+
+cleanup:
+	if (!error && data.index != NULL &&
+		(data.strategy & CHECKOUT_INDEX_DONT_WRITE_MASK) == 0)
+		error = git_index_write(data.index);
+
+	git_diff_free(data.diff);
+	git_iterator_free(workdir);
+	git_iterator_free(baseline);
+	git__free(actions);
+	git__free(counts);
+	checkout_data_clear(&data);
+
+	return error;
+}
+
+int git_checkout_index(
+	git_repository *repo,
+	git_index *index,
+	const git_checkout_options *opts)
+{
+	int error, owned = 0;
+	git_iterator *index_i;
+
+	if (!index && !repo) {
+		giterr_set(GITERR_CHECKOUT,
+			"must provide either repository or index to checkout");
+		return -1;
+	}
+
+	if (index && repo &&
+		git_index_owner(index) &&
+		git_index_owner(index) != repo) {
+		giterr_set(GITERR_CHECKOUT,
+			"index to checkout does not match repository");
+		return -1;
+	} else if(index && repo && !git_index_owner(index)) {
+		GIT_REFCOUNT_OWN(index, repo);
+		owned = 1;
+	}
+
+	if (!repo)
+		repo = git_index_owner(index);
+
+	if (!index && (error = git_repository_index__weakptr(&index, repo)) < 0)
+		return error;
+	GIT_REFCOUNT_INC(index);
+
+	if (!(error = git_iterator_for_index(&index_i, repo, index, NULL)))
+		error = git_checkout_iterator(index_i, index, opts);
+
+	if (owned)
+		GIT_REFCOUNT_OWN(index, NULL);
+
+	git_iterator_free(index_i);
+	git_index_free(index);
+
+	return error;
+}
+
+int git_checkout_tree(
+	git_repository *repo,
+	const git_object *treeish,
+	const git_checkout_options *opts)
+{
+	int error;
+	git_index *index;
+	git_tree *tree = NULL;
+	git_iterator *tree_i = NULL;
+	git_iterator_options iter_opts = GIT_ITERATOR_OPTIONS_INIT;
+
+	if (!treeish && !repo) {
+		giterr_set(GITERR_CHECKOUT,
+			"must provide either repository or tree to checkout");
+		return -1;
+	}
+	if (treeish && repo && git_object_owner(treeish) != repo) {
+		giterr_set(GITERR_CHECKOUT,
+			"object to checkout does not match repository");
+		return -1;
+	}
+
+	if (!repo)
+		repo = git_object_owner(treeish);
+
+	if (treeish) {
+		if (git_object_peel((git_object **)&tree, treeish, GIT_OBJ_TREE) < 0) {
+			giterr_set(
+				GITERR_CHECKOUT, "provided object cannot be peeled to a tree");
+			return -1;
+		}
+	}
+	else {
+		if ((error = checkout_lookup_head_tree(&tree, repo)) < 0) {
+			if (error != GIT_EUNBORNBRANCH)
+				giterr_set(
+					GITERR_CHECKOUT,
+					"HEAD could not be peeled to a tree and no treeish given");
+			return error;
+		}
+	}
+
+	if ((error = git_repository_index(&index, repo)) < 0)
+		return error;
+
+	if (opts && (opts->checkout_strategy & GIT_CHECKOUT_DISABLE_PATHSPEC_MATCH)) {
+		iter_opts.pathlist.count = opts->paths.count;
+		iter_opts.pathlist.strings = opts->paths.strings;
+	}
+
+	if (!(error = git_iterator_for_tree(&tree_i, tree, &iter_opts)))
+		error = git_checkout_iterator(tree_i, index, opts);
+
+	git_iterator_free(tree_i);
+	git_index_free(index);
+	git_tree_free(tree);
+
+	return error;
+}
+
+int git_checkout_head(
+	git_repository *repo,
+	const git_checkout_options *opts)
+{
+	assert(repo);
+	return git_checkout_tree(repo, NULL, opts);
+}
+
+int git_checkout_init_options(git_checkout_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_checkout_options, GIT_CHECKOUT_OPTIONS_INIT);
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/checkout.h

diff --git a/vendor/libgit2-sys/libgit2/src/checkout.h b/vendor/libgit2-sys/libgit2/src/checkout.h
new file mode 100644
index 0000000..517fbf3
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/checkout.h
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_checkout_h__
+#define INCLUDE_checkout_h__
+
+#include "common.h"
+
+#include "git2/checkout.h"
+#include "iterator.h"
+
+#define GIT_CHECKOUT__NOTIFY_CONFLICT_TREE (1u << 12)
+
+/**
+ * Update the working directory to match the target iterator.  The
+ * expected baseline value can be passed in via the checkout options
+ * or else will default to the HEAD commit.
+ */
+extern int git_checkout_iterator(
+	git_iterator *target,
+	git_index *index,
+	const git_checkout_options *opts);
+
+#endif

vendor/libgit2-sys/libgit2/src/cherrypick.c

diff --git a/vendor/libgit2-sys/libgit2/src/cherrypick.c b/vendor/libgit2-sys/libgit2/src/cherrypick.c
new file mode 100644
index 0000000..e42b748
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/cherrypick.c
@@ -0,0 +1,230 @@
+/*
+* Copyright (C) the libgit2 contributors. All rights reserved.
+*
+* This file is part of libgit2, distributed under the GNU GPL v2 with
+* a Linking Exception. For full terms see the included COPYING file.
+*/
+
+#include "common.h"
+
+#include "repository.h"
+#include "filebuf.h"
+#include "merge.h"
+#include "vector.h"
+#include "index.h"
+
+#include "git2/types.h"
+#include "git2/merge.h"
+#include "git2/cherrypick.h"
+#include "git2/commit.h"
+#include "git2/sys/commit.h"
+
+#define GIT_CHERRYPICK_FILE_MODE		0666
+
+static int write_cherrypick_head(
+	git_repository *repo,
+	const char *commit_oidstr)
+{
+	git_filebuf file = GIT_FILEBUF_INIT;
+	git_buf file_path = GIT_BUF_INIT;
+	int error = 0;
+
+	if ((error = git_buf_joinpath(&file_path, repo->gitdir, GIT_CHERRYPICK_HEAD_FILE)) >= 0 &&
+		(error = git_filebuf_open(&file, file_path.ptr, GIT_FILEBUF_FORCE, GIT_CHERRYPICK_FILE_MODE)) >= 0 &&
+		(error = git_filebuf_printf(&file, "%s\n", commit_oidstr)) >= 0)
+		error = git_filebuf_commit(&file);
+
+	if (error < 0)
+		git_filebuf_cleanup(&file);
+
+	git_buf_free(&file_path);
+
+	return error;
+}
+
+static int write_merge_msg(
+	git_repository *repo,
+	const char *commit_msg)
+{
+	git_filebuf file = GIT_FILEBUF_INIT;
+	git_buf file_path = GIT_BUF_INIT;
+	int error = 0;
+
+	if ((error = git_buf_joinpath(&file_path, repo->gitdir, GIT_MERGE_MSG_FILE)) < 0 ||
+		(error = git_filebuf_open(&file, file_path.ptr, GIT_FILEBUF_FORCE, GIT_CHERRYPICK_FILE_MODE)) < 0 ||
+		(error = git_filebuf_printf(&file, "%s", commit_msg)) < 0)
+		goto cleanup;
+
+	error = git_filebuf_commit(&file);
+
+cleanup:
+	if (error < 0)
+		git_filebuf_cleanup(&file);
+
+	git_buf_free(&file_path);
+
+	return error;
+}
+
+static int cherrypick_normalize_opts(
+	git_repository *repo,
+	git_cherrypick_options *opts,
+	const git_cherrypick_options *given,
+	const char *their_label)
+{
+	int error = 0;
+	unsigned int default_checkout_strategy = GIT_CHECKOUT_SAFE |
+		GIT_CHECKOUT_ALLOW_CONFLICTS;
+
+	GIT_UNUSED(repo);
+
+	if (given != NULL)
+		memcpy(opts, given, sizeof(git_cherrypick_options));
+	else {
+		git_cherrypick_options default_opts = GIT_CHERRYPICK_OPTIONS_INIT;
+		memcpy(opts, &default_opts, sizeof(git_cherrypick_options));
+	}
+
+	if (!opts->checkout_opts.checkout_strategy)
+		opts->checkout_opts.checkout_strategy = default_checkout_strategy;
+
+	if (!opts->checkout_opts.our_label)
+		opts->checkout_opts.our_label = "HEAD";
+
+	if (!opts->checkout_opts.their_label)
+		opts->checkout_opts.their_label = their_label;
+
+	return error;
+}
+
+static int cherrypick_state_cleanup(git_repository *repo)
+{
+	const char *state_files[] = { GIT_CHERRYPICK_HEAD_FILE, GIT_MERGE_MSG_FILE };
+
+	return git_repository__cleanup_files(repo, state_files, ARRAY_SIZE(state_files));
+}
+
+static int cherrypick_seterr(git_commit *commit, const char *fmt)
+{
+	char commit_oidstr[GIT_OID_HEXSZ + 1];
+
+	giterr_set(GITERR_CHERRYPICK, fmt,
+		git_oid_tostr(commit_oidstr, GIT_OID_HEXSZ + 1, git_commit_id(commit)));
+
+	return -1;
+}
+
+int git_cherrypick_commit(
+	git_index **out,
+	git_repository *repo,
+	git_commit *cherrypick_commit,
+	git_commit *our_commit,
+	unsigned int mainline,
+	const git_merge_options *merge_opts)
+{
+	git_commit *parent_commit = NULL;
+	git_tree *parent_tree = NULL, *our_tree = NULL, *cherrypick_tree = NULL;
+	int parent = 0, error = 0;
+
+	assert(out && repo && cherrypick_commit && our_commit);
+
+	if (git_commit_parentcount(cherrypick_commit) > 1) {
+		if (!mainline)
+			return cherrypick_seterr(cherrypick_commit,
+				"mainline branch is not specified but %s is a merge commit");
+
+		parent = mainline;
+	} else {
+		if (mainline)
+			return cherrypick_seterr(cherrypick_commit,
+				"mainline branch specified but %s is not a merge commit");
+
+		parent = git_commit_parentcount(cherrypick_commit);
+	}
+
+	if (parent &&
+		((error = git_commit_parent(&parent_commit, cherrypick_commit, (parent - 1))) < 0 ||
+		(error = git_commit_tree(&parent_tree, parent_commit)) < 0))
+		goto done;
+
+	if ((error = git_commit_tree(&cherrypick_tree, cherrypick_commit)) < 0 ||
+		(error = git_commit_tree(&our_tree, our_commit)) < 0)
+		goto done;
+
+	error = git_merge_trees(out, repo, parent_tree, our_tree, cherrypick_tree, merge_opts);
+
+done:
+	git_tree_free(parent_tree);
+	git_tree_free(our_tree);
+	git_tree_free(cherrypick_tree);
+	git_commit_free(parent_commit);
+
+	return error;
+}
+
+int git_cherrypick(
+	git_repository *repo,
+	git_commit *commit,
+	const git_cherrypick_options *given_opts)
+{
+	git_cherrypick_options opts;
+	git_reference *our_ref = NULL;
+	git_commit *our_commit = NULL;
+	char commit_oidstr[GIT_OID_HEXSZ + 1];
+	const char *commit_msg, *commit_summary;
+	git_buf their_label = GIT_BUF_INIT;
+	git_index *index = NULL;
+	git_indexwriter indexwriter = GIT_INDEXWRITER_INIT;
+	int error = 0;
+
+	assert(repo && commit);
+
+	GITERR_CHECK_VERSION(given_opts, GIT_CHERRYPICK_OPTIONS_VERSION, "git_cherrypick_options");
+
+	if ((error = git_repository__ensure_not_bare(repo, "cherry-pick")) < 0)
+		return error;
+
+	if ((commit_msg = git_commit_message(commit)) == NULL ||
+		(commit_summary = git_commit_summary(commit)) == NULL) {
+		error = -1;
+		goto on_error;
+	}
+
+	git_oid_nfmt(commit_oidstr, sizeof(commit_oidstr), git_commit_id(commit));
+
+	if ((error = write_merge_msg(repo, commit_msg)) < 0 ||
+		(error = git_buf_printf(&their_label, "%.7s... %s", commit_oidstr, commit_summary)) < 0 ||
+		(error = cherrypick_normalize_opts(repo, &opts, given_opts, git_buf_cstr(&their_label))) < 0 ||
+		(error = git_indexwriter_init_for_operation(&indexwriter, repo, &opts.checkout_opts.checkout_strategy)) < 0 ||
+		(error = write_cherrypick_head(repo, commit_oidstr)) < 0 ||
+		(error = git_repository_head(&our_ref, repo)) < 0 ||
+		(error = git_reference_peel((git_object **)&our_commit, our_ref, GIT_OBJ_COMMIT)) < 0 ||
+		(error = git_cherrypick_commit(&index, repo, commit, our_commit, opts.mainline, &opts.merge_opts)) < 0 ||
+		(error = git_merge__check_result(repo, index)) < 0 ||
+		(error = git_merge__append_conflicts_to_merge_msg(repo, index)) < 0 ||
+		(error = git_checkout_index(repo, index, &opts.checkout_opts)) < 0 ||
+		(error = git_indexwriter_commit(&indexwriter)) < 0)
+		goto on_error;
+
+	goto done;
+
+on_error:
+	cherrypick_state_cleanup(repo);
+
+done:
+	git_indexwriter_cleanup(&indexwriter);
+	git_index_free(index);
+	git_commit_free(our_commit);
+	git_reference_free(our_ref);
+	git_buf_free(&their_label);
+
+	return error;
+}
+
+int git_cherrypick_init_options(
+	git_cherrypick_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_cherrypick_options, GIT_CHERRYPICK_OPTIONS_INIT);
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/clone.c

diff --git a/vendor/libgit2-sys/libgit2/src/clone.c b/vendor/libgit2-sys/libgit2/src/clone.c
new file mode 100644
index 0000000..8764bb7
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/clone.c
@@ -0,0 +1,558 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "clone.h"
+
+#include <assert.h>
+
+#include "git2/clone.h"
+#include "git2/remote.h"
+#include "git2/revparse.h"
+#include "git2/branch.h"
+#include "git2/config.h"
+#include "git2/checkout.h"
+#include "git2/commit.h"
+#include "git2/tree.h"
+
+#include "remote.h"
+#include "fileops.h"
+#include "refs.h"
+#include "path.h"
+#include "repository.h"
+#include "odb.h"
+
+static int clone_local_into(git_repository *repo, git_remote *remote, const git_fetch_options *fetch_opts, const git_checkout_options *co_opts, const char *branch, int link);
+
+static int create_branch(
+	git_reference **branch,
+	git_repository *repo,
+	const git_oid *target,
+	const char *name,
+	const char *log_message)
+{
+	git_commit *head_obj = NULL;
+	git_reference *branch_ref = NULL;
+	git_buf refname = GIT_BUF_INIT;
+	int error;
+
+	/* Find the target commit */
+	if ((error = git_commit_lookup(&head_obj, repo, target)) < 0)
+		return error;
+
+	/* Create the new branch */
+	if ((error = git_buf_printf(&refname, GIT_REFS_HEADS_DIR "%s", name)) < 0)
+		return error;
+
+	error = git_reference_create(&branch_ref, repo, git_buf_cstr(&refname), target, 0, log_message);
+	git_buf_free(&refname);
+	git_commit_free(head_obj);
+
+	if (!error)
+		*branch = branch_ref;
+	else
+		git_reference_free(branch_ref);
+
+	return error;
+}
+
+static int setup_tracking_config(
+	git_repository *repo,
+	const char *branch_name,
+	const char *remote_name,
+	const char *merge_target)
+{
+	git_config *cfg;
+	git_buf remote_key = GIT_BUF_INIT, merge_key = GIT_BUF_INIT;
+	int error = -1;
+
+	if (git_repository_config__weakptr(&cfg, repo) < 0)
+		return -1;
+
+	if (git_buf_printf(&remote_key, "branch.%s.remote", branch_name) < 0)
+		goto cleanup;
+
+	if (git_buf_printf(&merge_key, "branch.%s.merge", branch_name) < 0)
+		goto cleanup;
+
+	if (git_config_set_string(cfg, git_buf_cstr(&remote_key), remote_name) < 0)
+		goto cleanup;
+
+	if (git_config_set_string(cfg, git_buf_cstr(&merge_key), merge_target) < 0)
+		goto cleanup;
+
+	error = 0;
+
+cleanup:
+	git_buf_free(&remote_key);
+	git_buf_free(&merge_key);
+	return error;
+}
+
+static int create_tracking_branch(
+	git_reference **branch,
+	git_repository *repo,
+	const git_oid *target,
+	const char *branch_name,
+	const char *log_message)
+{
+	int error;
+
+	if ((error = create_branch(branch, repo, target, branch_name, log_message)) < 0)
+		return error;
+
+	return setup_tracking_config(
+		repo,
+		branch_name,
+		GIT_REMOTE_ORIGIN,
+		git_reference_name(*branch));
+}
+
+static int update_head_to_new_branch(
+	git_repository *repo,
+	const git_oid *target,
+	const char *name,
+	const char *reflog_message)
+{
+	git_reference *tracking_branch = NULL;
+	int error;
+
+	if (!git__prefixcmp(name, GIT_REFS_HEADS_DIR))
+		name += strlen(GIT_REFS_HEADS_DIR);
+
+	error = create_tracking_branch(&tracking_branch, repo, target, name,
+			reflog_message);
+
+	if (!error)
+		error = git_repository_set_head(
+			repo, git_reference_name(tracking_branch));
+
+	git_reference_free(tracking_branch);
+
+	/* if it already existed, then the user's refspec created it for us, ignore it' */
+	if (error == GIT_EEXISTS)
+		error = 0;
+
+	return error;
+}
+
+static int update_head_to_remote(
+		git_repository *repo,
+		git_remote *remote,
+		const char *reflog_message)
+{
+	int error = 0;
+	size_t refs_len;
+	git_refspec *refspec;
+	const git_remote_head *remote_head, **refs;
+	const git_oid *remote_head_id;
+	git_buf remote_master_name = GIT_BUF_INIT;
+	git_buf branch = GIT_BUF_INIT;
+
+	if ((error = git_remote_ls(&refs, &refs_len, remote)) < 0)
+		return error;
+
+	/* We cloned an empty repository or one with an unborn HEAD */
+	if (refs_len == 0 || strcmp(refs[0]->name, GIT_HEAD_FILE))
+		return setup_tracking_config(
+			repo, "master", GIT_REMOTE_ORIGIN, GIT_REFS_HEADS_MASTER_FILE);
+
+	/* We know we have HEAD, let's see where it points */
+	remote_head = refs[0];
+	assert(remote_head);
+
+	remote_head_id = &remote_head->oid;
+
+	error = git_remote_default_branch(&branch, remote);
+	if (error == GIT_ENOTFOUND) {
+		error = git_repository_set_head_detached(
+			repo, remote_head_id);
+		goto cleanup;
+	}
+
+	refspec = git_remote__matching_refspec(remote, git_buf_cstr(&branch));
+
+	if (refspec == NULL) {
+		giterr_set(GITERR_NET, "the remote's default branch does not fit the refspec configuration");
+		error = GIT_EINVALIDSPEC;
+		goto cleanup;
+	}
+
+	/* Determine the remote tracking reference name from the local master */
+	if ((error = git_refspec_transform(
+		&remote_master_name,
+		refspec,
+		git_buf_cstr(&branch))) < 0)
+		goto cleanup;
+
+	error = update_head_to_new_branch(
+		repo,
+		remote_head_id,
+		git_buf_cstr(&branch),
+		reflog_message);
+
+cleanup:
+	git_buf_free(&remote_master_name);
+	git_buf_free(&branch);
+
+	return error;
+}
+
+static int update_head_to_branch(
+		git_repository *repo,
+		const char *remote_name,
+		const char *branch,
+		const char *reflog_message)
+{
+	int retcode;
+	git_buf remote_branch_name = GIT_BUF_INIT;
+	git_reference* remote_ref = NULL;
+
+	assert(remote_name && branch);
+
+	if ((retcode = git_buf_printf(&remote_branch_name, GIT_REFS_REMOTES_DIR "%s/%s",
+		remote_name, branch)) < 0 )
+		goto cleanup;
+
+	if ((retcode = git_reference_lookup(&remote_ref, repo, git_buf_cstr(&remote_branch_name))) < 0)
+		goto cleanup;
+
+	retcode = update_head_to_new_branch(repo, git_reference_target(remote_ref), branch,
+			reflog_message);
+
+cleanup:
+	git_reference_free(remote_ref);
+	git_buf_free(&remote_branch_name);
+	return retcode;
+}
+
+static int default_repository_create(git_repository **out, const char *path, int bare, void *payload)
+{
+	GIT_UNUSED(payload);
+
+	return git_repository_init(out, path, bare);
+}
+
+static int default_remote_create(
+		git_remote **out,
+		git_repository *repo,
+		const char *name,
+		const char *url,
+		void *payload)
+{
+	GIT_UNUSED(payload);
+
+	return git_remote_create(out, repo, name, url);
+}
+
+/*
+ * submodules?
+ */
+
+static int create_and_configure_origin(
+		git_remote **out,
+		git_repository *repo,
+		const char *url,
+		const git_clone_options *options)
+{
+	int error;
+	git_remote *origin = NULL;
+	char buf[GIT_PATH_MAX];
+	git_remote_create_cb remote_create = options->remote_cb;
+	void *payload = options->remote_cb_payload;
+
+	/* If the path exists and is a dir, the url should be the absolute path */
+	if (git_path_root(url) < 0 && git_path_exists(url) && git_path_isdir(url)) {
+		if (p_realpath(url, buf) == NULL)
+			return -1;
+
+		url = buf;
+	}
+
+	if (!remote_create) {
+		remote_create = default_remote_create;
+		payload = NULL;
+	}
+
+	if ((error = remote_create(&origin, repo, "origin", url, payload)) < 0)
+		goto on_error;
+
+	*out = origin;
+	return 0;
+
+on_error:
+	git_remote_free(origin);
+	return error;
+}
+
+static bool should_checkout(
+	git_repository *repo,
+	bool is_bare,
+	const git_checkout_options *opts)
+{
+	if (is_bare)
+		return false;
+
+	if (!opts)
+		return false;
+
+	if (opts->checkout_strategy == GIT_CHECKOUT_NONE)
+		return false;
+
+	return !git_repository_head_unborn(repo);
+}
+
+static int checkout_branch(git_repository *repo, git_remote *remote, const git_checkout_options *co_opts, const char *branch, const char *reflog_message)
+{
+	int error;
+
+	if (branch)
+		error = update_head_to_branch(repo, git_remote_name(remote), branch,
+				reflog_message);
+	/* Point HEAD to the same ref as the remote's head */
+	else
+		error = update_head_to_remote(repo, remote, reflog_message);
+
+	if (!error && should_checkout(repo, git_repository_is_bare(repo), co_opts))
+		error = git_checkout_head(repo, co_opts);
+
+	return error;
+}
+
+static int clone_into(git_repository *repo, git_remote *_remote, const git_fetch_options *opts, const git_checkout_options *co_opts, const char *branch)
+{
+	int error;
+	git_buf reflog_message = GIT_BUF_INIT;
+	git_fetch_options fetch_opts;
+	git_remote *remote;
+
+	assert(repo && _remote);
+
+	if (!git_repository_is_empty(repo)) {
+		giterr_set(GITERR_INVALID, "the repository is not empty");
+		return -1;
+	}
+
+	if ((error = git_remote_dup(&remote, _remote)) < 0)
+		return error;
+
+	memcpy(&fetch_opts, opts, sizeof(git_fetch_options));
+	fetch_opts.update_fetchhead = 0;
+	fetch_opts.download_tags = GIT_REMOTE_DOWNLOAD_TAGS_ALL;
+	git_buf_printf(&reflog_message, "clone: from %s", git_remote_url(remote));
+
+	if ((error = git_remote_fetch(remote, NULL, &fetch_opts, git_buf_cstr(&reflog_message))) != 0)
+		goto cleanup;
+
+	error = checkout_branch(repo, remote, co_opts, branch, git_buf_cstr(&reflog_message));
+
+cleanup:
+	git_remote_free(remote);
+	git_buf_free(&reflog_message);
+
+	return error;
+}
+
+int git_clone__should_clone_local(const char *url_or_path, git_clone_local_t local)
+{
+	git_buf fromurl = GIT_BUF_INIT;
+	const char *path = url_or_path;
+	bool is_url, is_local;
+
+	if (local == GIT_CLONE_NO_LOCAL)
+		return 0;
+
+	if ((is_url = git_path_is_local_file_url(url_or_path)) != 0) {
+		if (git_path_fromurl(&fromurl, url_or_path) < 0) {
+			is_local = -1;
+			goto done;
+		}
+
+		path = fromurl.ptr;
+	}
+
+	is_local = (!is_url || local != GIT_CLONE_LOCAL_AUTO) &&
+		git_path_isdir(path);
+
+done:
+	git_buf_free(&fromurl);
+	return is_local;
+}
+
+int git_clone(
+	git_repository **out,
+	const char *url,
+	const char *local_path,
+	const git_clone_options *_options)
+{
+	int error = 0;
+	git_repository *repo = NULL;
+	git_remote *origin;
+	git_clone_options options = GIT_CLONE_OPTIONS_INIT;
+	uint32_t rmdir_flags = GIT_RMDIR_REMOVE_FILES;
+	git_repository_create_cb repository_cb;
+
+	assert(out && url && local_path);
+
+	if (_options)
+		memcpy(&options, _options, sizeof(git_clone_options));
+
+	GITERR_CHECK_VERSION(&options, GIT_CLONE_OPTIONS_VERSION, "git_clone_options");
+
+	/* Only clone to a new directory or an empty directory */
+	if (git_path_exists(local_path) && !git_path_is_empty_dir(local_path)) {
+		giterr_set(GITERR_INVALID,
+			"'%s' exists and is not an empty directory", local_path);
+		return GIT_EEXISTS;
+	}
+
+	/* Only remove the root directory on failure if we create it */
+	if (git_path_exists(local_path))
+		rmdir_flags |= GIT_RMDIR_SKIP_ROOT;
+
+	if (options.repository_cb)
+		repository_cb = options.repository_cb;
+	else
+		repository_cb = default_repository_create;
+
+	if ((error = repository_cb(&repo, local_path, options.bare, options.repository_cb_payload)) < 0)
+		return error;
+
+	if (!(error = create_and_configure_origin(&origin, repo, url, &options))) {
+		int clone_local = git_clone__should_clone_local(url, options.local);
+		int link = options.local != GIT_CLONE_LOCAL_NO_LINKS;
+
+		if (clone_local == 1)
+			error = clone_local_into(
+				repo, origin, &options.fetch_opts, &options.checkout_opts,
+				options.checkout_branch, link);
+		else if (clone_local == 0)
+			error = clone_into(
+				repo, origin, &options.fetch_opts, &options.checkout_opts,
+				options.checkout_branch);
+		else
+			error = -1;
+
+		git_remote_free(origin);
+	}
+
+	if (error != 0) {
+		git_error_state last_error = {0};
+		giterr_state_capture(&last_error, error);
+
+		git_repository_free(repo);
+		repo = NULL;
+
+		(void)git_futils_rmdir_r(local_path, NULL, rmdir_flags);
+
+		giterr_state_restore(&last_error);
+	}
+
+	*out = repo;
+	return error;
+}
+
+int git_clone_init_options(git_clone_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_clone_options, GIT_CLONE_OPTIONS_INIT);
+	return 0;
+}
+
+static bool can_link(const char *src, const char *dst, int link)
+{
+#ifdef GIT_WIN32
+	GIT_UNUSED(src);
+	GIT_UNUSED(dst);
+	GIT_UNUSED(link);
+	return false;
+#else
+
+	struct stat st_src, st_dst;
+
+	if (!link)
+		return false;
+
+	if (p_stat(src, &st_src) < 0)
+		return false;
+
+	if (p_stat(dst, &st_dst) < 0)
+		return false;
+
+	return st_src.st_dev == st_dst.st_dev;
+#endif
+}
+
+static int clone_local_into(git_repository *repo, git_remote *remote, const git_fetch_options *fetch_opts, const git_checkout_options *co_opts, const char *branch, int link)
+{
+	int error, flags;
+	git_repository *src;
+	git_buf src_odb = GIT_BUF_INIT, dst_odb = GIT_BUF_INIT, src_path = GIT_BUF_INIT;
+	git_buf reflog_message = GIT_BUF_INIT;
+
+	assert(repo && remote);
+
+	if (!git_repository_is_empty(repo)) {
+		giterr_set(GITERR_INVALID, "the repository is not empty");
+		return -1;
+	}
+
+	/*
+	 * Let's figure out what path we should use for the source
+	 * repo, if it's not rooted, the path should be relative to
+	 * the repository's worktree/gitdir.
+	 */
+	if ((error = git_path_from_url_or_path(&src_path, git_remote_url(remote))) < 0)
+		return error;
+
+	/* Copy .git/objects/ from the source to the target */
+	if ((error = git_repository_open(&src, git_buf_cstr(&src_path))) < 0) {
+		git_buf_free(&src_path);
+		return error;
+	}
+
+	if (git_repository_item_path(&src_odb, src, GIT_REPOSITORY_ITEM_OBJECTS) < 0
+		|| git_repository_item_path(&dst_odb, repo, GIT_REPOSITORY_ITEM_OBJECTS) < 0) {
+		error = -1;
+		goto cleanup;
+	}
+
+	flags = 0;
+	if (can_link(git_repository_path(src), git_repository_path(repo), link))
+		flags |= GIT_CPDIR_LINK_FILES;
+
+	error = git_futils_cp_r(git_buf_cstr(&src_odb), git_buf_cstr(&dst_odb),
+				flags, GIT_OBJECT_DIR_MODE);
+
+	/*
+	 * can_link() doesn't catch all variations, so if we hit an
+	 * error and did want to link, let's try again without trying
+	 * to link.
+	 */
+	if (error < 0 && link) {
+		flags &= ~GIT_CPDIR_LINK_FILES;
+		error = git_futils_cp_r(git_buf_cstr(&src_odb), git_buf_cstr(&dst_odb),
+					flags, GIT_OBJECT_DIR_MODE);
+	}
+
+	if (error < 0)
+		goto cleanup;
+
+	git_buf_printf(&reflog_message, "clone: from %s", git_remote_url(remote));
+
+	if ((error = git_remote_fetch(remote, NULL, fetch_opts, git_buf_cstr(&reflog_message))) != 0)
+		goto cleanup;
+
+	error = checkout_branch(repo, remote, co_opts, branch, git_buf_cstr(&reflog_message));
+
+cleanup:
+	git_buf_free(&reflog_message);
+	git_buf_free(&src_path);
+	git_buf_free(&src_odb);
+	git_buf_free(&dst_odb);
+	git_repository_free(src);
+	return error;
+}

vendor/libgit2-sys/libgit2/src/clone.h

diff --git a/vendor/libgit2-sys/libgit2/src/clone.h b/vendor/libgit2-sys/libgit2/src/clone.h
new file mode 100644
index 0000000..864b590
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/clone.h
@@ -0,0 +1,16 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_clone_h__
+#define INCLUDE_clone_h__
+
+#include "common.h"
+
+#include "git2/clone.h"
+
+extern int git_clone__should_clone_local(const char *url, git_clone_local_t local);
+
+#endif

vendor/libgit2-sys/libgit2/src/commit.c

diff --git a/vendor/libgit2-sys/libgit2/src/commit.c b/vendor/libgit2-sys/libgit2/src/commit.c
new file mode 100644
index 0000000..838688b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/commit.c
@@ -0,0 +1,891 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "commit.h"
+
+#include "git2/common.h"
+#include "git2/object.h"
+#include "git2/repository.h"
+#include "git2/signature.h"
+#include "git2/sys/commit.h"
+
+#include "odb.h"
+#include "commit.h"
+#include "signature.h"
+#include "message.h"
+#include "refs.h"
+#include "object.h"
+#include "oidarray.h"
+
+void git_commit__free(void *_commit)
+{
+	git_commit *commit = _commit;
+
+	git_array_clear(commit->parent_ids);
+
+	git_signature_free(commit->author);
+	git_signature_free(commit->committer);
+
+	git__free(commit->raw_header);
+	git__free(commit->raw_message);
+	git__free(commit->message_encoding);
+	git__free(commit->summary);
+	git__free(commit->body);
+
+	git__free(commit);
+}
+
+static int git_commit__create_buffer_internal(
+	git_buf *out,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message,
+	const git_oid *tree,
+	git_array_oid_t *parents)
+{
+	size_t i = 0;
+	const git_oid *parent;
+
+	assert(out && tree);
+
+	git_oid__writebuf(out, "tree ", tree);
+
+	for (i = 0; i < git_array_size(*parents); i++) {
+		parent = git_array_get(*parents, i);
+		git_oid__writebuf(out, "parent ", parent);
+	}
+
+	git_signature__writebuf(out, "author ", author);
+	git_signature__writebuf(out, "committer ", committer);
+
+	if (message_encoding != NULL)
+		git_buf_printf(out, "encoding %s\n", message_encoding);
+
+	git_buf_putc(out, '\n');
+
+	if (git_buf_puts(out, message) < 0)
+		goto on_error;
+
+	return 0;
+
+on_error:
+	git_buf_free(out);
+	return -1;
+}
+
+static int validate_tree_and_parents(git_array_oid_t *parents, git_repository *repo, const git_oid *tree,
+				     git_commit_parent_callback parent_cb, void *parent_payload,
+				     const git_oid *current_id, bool validate)
+{
+	size_t i;
+	int error;
+	git_oid *parent_cpy;
+	const git_oid *parent;
+
+	if (validate && !git_object__is_valid(repo, tree, GIT_OBJ_TREE))
+		return -1;
+
+	i = 0;
+	while ((parent = parent_cb(i, parent_payload)) != NULL) {
+		if (validate && !git_object__is_valid(repo, parent, GIT_OBJ_COMMIT)) {
+			error = -1;
+			goto on_error;
+		}
+
+		parent_cpy = git_array_alloc(*parents);
+		GITERR_CHECK_ALLOC(parent_cpy);
+
+		git_oid_cpy(parent_cpy, parent);
+		i++;
+	}
+
+	if (current_id && (parents->size == 0 || git_oid_cmp(current_id, git_array_get(*parents, 0)))) {
+		giterr_set(GITERR_OBJECT, "failed to create commit: current tip is not the first parent");
+		error = GIT_EMODIFIED;
+		goto on_error;
+	}
+
+	return 0;
+
+on_error:
+	git_array_clear(*parents);
+	return error;
+}
+
+static int git_commit__create_internal(
+	git_oid *id,
+	git_repository *repo,
+	const char *update_ref,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message,
+	const git_oid *tree,
+	git_commit_parent_callback parent_cb,
+	void *parent_payload,
+	bool validate)
+{
+	int error;
+	git_odb *odb;
+	git_reference *ref = NULL;
+	git_buf buf = GIT_BUF_INIT;
+	const git_oid *current_id = NULL;
+	git_array_oid_t parents = GIT_ARRAY_INIT;
+
+	if (update_ref) {
+		error = git_reference_lookup_resolved(&ref, repo, update_ref, 10);
+		if (error < 0 && error != GIT_ENOTFOUND)
+			return error;
+	}
+	giterr_clear();
+
+	if (ref)
+		current_id = git_reference_target(ref);
+
+	if ((error = validate_tree_and_parents(&parents, repo, tree, parent_cb, parent_payload, current_id, validate)) < 0)
+		goto cleanup;
+
+	error = git_commit__create_buffer_internal(&buf, author, committer,
+						   message_encoding, message, tree,
+						   &parents);
+
+	if (error < 0)
+		goto cleanup;
+
+	if (git_repository_odb__weakptr(&odb, repo) < 0)
+		goto cleanup;
+
+	if (git_odb__freshen(odb, tree) < 0)
+		goto cleanup;
+
+	if (git_odb_write(id, odb, buf.ptr, buf.size, GIT_OBJ_COMMIT) < 0)
+		goto cleanup;
+
+
+	if (update_ref != NULL) {
+		error = git_reference__update_for_commit(
+			repo, ref, update_ref, id, "commit");
+		goto cleanup;
+	}
+
+cleanup:
+	git_array_clear(parents);
+	git_reference_free(ref);
+	git_buf_free(&buf);
+	return error;
+}
+
+int git_commit_create_from_callback(
+	git_oid *id,
+	git_repository *repo,
+	const char *update_ref,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message,
+	const git_oid *tree,
+	git_commit_parent_callback parent_cb,
+	void *parent_payload)
+{
+	return git_commit__create_internal(
+		id, repo, update_ref, author, committer, message_encoding, message,
+		tree, parent_cb, parent_payload, true);
+}
+
+typedef struct {
+	size_t total;
+	va_list args;
+} commit_parent_varargs;
+
+static const git_oid *commit_parent_from_varargs(size_t curr, void *payload)
+{
+	commit_parent_varargs *data = payload;
+	const git_commit *commit;
+	if (curr >= data->total)
+		return NULL;
+	commit = va_arg(data->args, const git_commit *);
+	return commit ? git_commit_id(commit) : NULL;
+}
+
+int git_commit_create_v(
+	git_oid *id,
+	git_repository *repo,
+	const char *update_ref,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message,
+	const git_tree *tree,
+	size_t parent_count,
+	...)
+{
+	int error = 0;
+	commit_parent_varargs data;
+
+	assert(tree && git_tree_owner(tree) == repo);
+
+	data.total = parent_count;
+	va_start(data.args, parent_count);
+
+	error = git_commit__create_internal(
+		id, repo, update_ref, author, committer,
+		message_encoding, message, git_tree_id(tree),
+		commit_parent_from_varargs, &data, false);
+
+	va_end(data.args);
+	return error;
+}
+
+typedef struct {
+	size_t total;
+	const git_oid **parents;
+} commit_parent_oids;
+
+static const git_oid *commit_parent_from_ids(size_t curr, void *payload)
+{
+	commit_parent_oids *data = payload;
+	return (curr < data->total) ? data->parents[curr] : NULL;
+}
+
+int git_commit_create_from_ids(
+	git_oid *id,
+	git_repository *repo,
+	const char *update_ref,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message,
+	const git_oid *tree,
+	size_t parent_count,
+	const git_oid *parents[])
+{
+	commit_parent_oids data = { parent_count, parents };
+
+	return git_commit__create_internal(
+		id, repo, update_ref, author, committer,
+		message_encoding, message, tree,
+		commit_parent_from_ids, &data, true);
+}
+
+typedef struct {
+	size_t total;
+	const git_commit **parents;
+	git_repository *repo;
+} commit_parent_data;
+
+static const git_oid *commit_parent_from_array(size_t curr, void *payload)
+{
+	commit_parent_data *data = payload;
+	const git_commit *commit;
+	if (curr >= data->total)
+		return NULL;
+	commit = data->parents[curr];
+	if (git_commit_owner(commit) != data->repo)
+		return NULL;
+	return git_commit_id(commit);
+}
+
+int git_commit_create(
+	git_oid *id,
+	git_repository *repo,
+	const char *update_ref,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message,
+	const git_tree *tree,
+	size_t parent_count,
+	const git_commit *parents[])
+{
+	commit_parent_data data = { parent_count, parents, repo };
+
+	assert(tree && git_tree_owner(tree) == repo);
+
+	return git_commit__create_internal(
+		id, repo, update_ref, author, committer,
+		message_encoding, message, git_tree_id(tree),
+		commit_parent_from_array, &data, false);
+}
+
+static const git_oid *commit_parent_for_amend(size_t curr, void *payload)
+{
+	const git_commit *commit_to_amend = payload;
+	if (curr >= git_array_size(commit_to_amend->parent_ids))
+		return NULL;
+	return git_array_get(commit_to_amend->parent_ids, curr);
+}
+
+int git_commit_amend(
+	git_oid *id,
+	const git_commit *commit_to_amend,
+	const char *update_ref,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message,
+	const git_tree *tree)
+{
+	git_repository *repo;
+	git_oid tree_id;
+	git_reference *ref;
+	int error;
+
+	assert(id && commit_to_amend);
+
+	repo = git_commit_owner(commit_to_amend);
+
+	if (!author)
+		author = git_commit_author(commit_to_amend);
+	if (!committer)
+		committer = git_commit_committer(commit_to_amend);
+	if (!message_encoding)
+		message_encoding = git_commit_message_encoding(commit_to_amend);
+	if (!message)
+		message = git_commit_message(commit_to_amend);
+
+	if (!tree) {
+		git_tree *old_tree;
+		GITERR_CHECK_ERROR( git_commit_tree(&old_tree, commit_to_amend) );
+		git_oid_cpy(&tree_id, git_tree_id(old_tree));
+		git_tree_free(old_tree);
+	} else {
+		assert(git_tree_owner(tree) == repo);
+		git_oid_cpy(&tree_id, git_tree_id(tree));
+	}
+
+	if (update_ref) {
+		if ((error = git_reference_lookup_resolved(&ref, repo, update_ref, 5)) < 0)
+			return error;
+
+		if (git_oid_cmp(git_commit_id(commit_to_amend), git_reference_target(ref))) {
+			git_reference_free(ref);
+			giterr_set(GITERR_REFERENCE, "commit to amend is not the tip of the given branch");
+			return -1;
+		}
+	}
+
+	error = git_commit__create_internal(
+		id, repo, NULL, author, committer, message_encoding, message,
+		&tree_id, commit_parent_for_amend, (void *)commit_to_amend, false);
+
+	if (!error && update_ref) {
+		error = git_reference__update_for_commit(
+			repo, ref, NULL, id, "commit");
+		git_reference_free(ref);
+	}
+
+	return error;
+}
+
+int git_commit__parse(void *_commit, git_odb_object *odb_obj)
+{
+	git_commit *commit = _commit;
+	const char *buffer_start = git_odb_object_data(odb_obj), *buffer;
+	const char *buffer_end = buffer_start + git_odb_object_size(odb_obj);
+	git_oid parent_id;
+	size_t header_len;
+	git_signature dummy_sig;
+
+	buffer = buffer_start;
+
+	/* Allocate for one, which will allow not to realloc 90% of the time  */
+	git_array_init_to_size(commit->parent_ids, 1);
+	GITERR_CHECK_ARRAY(commit->parent_ids);
+
+	/* The tree is always the first field */
+	if (git_oid__parse(&commit->tree_id, &buffer, buffer_end, "tree ") < 0)
+		goto bad_buffer;
+
+	/*
+	 * TODO: commit grafts!
+	 */
+
+	while (git_oid__parse(&parent_id, &buffer, buffer_end, "parent ") == 0) {
+		git_oid *new_id = git_array_alloc(commit->parent_ids);
+		GITERR_CHECK_ALLOC(new_id);
+
+		git_oid_cpy(new_id, &parent_id);
+	}
+
+	commit->author = git__malloc(sizeof(git_signature));
+	GITERR_CHECK_ALLOC(commit->author);
+
+	if (git_signature__parse(commit->author, &buffer, buffer_end, "author ", '\n') < 0)
+		return -1;
+
+	/* Some tools create multiple author fields, ignore the extra ones */
+	while ((size_t)(buffer_end - buffer) >= strlen("author ") && !git__prefixcmp(buffer, "author ")) {
+		if (git_signature__parse(&dummy_sig, &buffer, buffer_end, "author ", '\n') < 0)
+			return -1;
+
+		git__free(dummy_sig.name);
+		git__free(dummy_sig.email);
+	}
+
+	/* Always parse the committer; we need the commit time */
+	commit->committer = git__malloc(sizeof(git_signature));
+	GITERR_CHECK_ALLOC(commit->committer);
+
+	if (git_signature__parse(commit->committer, &buffer, buffer_end, "committer ", '\n') < 0)
+		return -1;
+
+	/* Parse add'l header entries */
+	while (buffer < buffer_end) {
+		const char *eoln = buffer;
+		if (buffer[-1] == '\n' && buffer[0] == '\n')
+			break;
+
+		while (eoln < buffer_end && *eoln != '\n')
+			++eoln;
+
+		if (git__prefixcmp(buffer, "encoding ") == 0) {
+			buffer += strlen("encoding ");
+
+			commit->message_encoding = git__strndup(buffer, eoln - buffer);
+			GITERR_CHECK_ALLOC(commit->message_encoding);
+		}
+
+		if (eoln < buffer_end && *eoln == '\n')
+			++eoln;
+		buffer = eoln;
+	}
+
+	header_len = buffer - buffer_start;
+	commit->raw_header = git__strndup(buffer_start, header_len);
+	GITERR_CHECK_ALLOC(commit->raw_header);
+
+	/* point "buffer" to data after header, +1 for the final LF */
+	buffer = buffer_start + header_len + 1;
+
+	/* extract commit message */
+	if (buffer <= buffer_end)
+		commit->raw_message = git__strndup(buffer, buffer_end - buffer);
+	else
+		commit->raw_message = git__strdup("");
+	GITERR_CHECK_ALLOC(commit->raw_message);
+
+	return 0;
+
+bad_buffer:
+	giterr_set(GITERR_OBJECT, "failed to parse bad commit object");
+	return -1;
+}
+
+#define GIT_COMMIT_GETTER(_rvalue, _name, _return) \
+	_rvalue git_commit_##_name(const git_commit *commit) \
+	{\
+		assert(commit); \
+		return _return; \
+	}
+
+GIT_COMMIT_GETTER(const git_signature *, author, commit->author)
+GIT_COMMIT_GETTER(const git_signature *, committer, commit->committer)
+GIT_COMMIT_GETTER(const char *, message_raw, commit->raw_message)
+GIT_COMMIT_GETTER(const char *, message_encoding, commit->message_encoding)
+GIT_COMMIT_GETTER(const char *, raw_header, commit->raw_header)
+GIT_COMMIT_GETTER(git_time_t, time, commit->committer->when.time)
+GIT_COMMIT_GETTER(int, time_offset, commit->committer->when.offset)
+GIT_COMMIT_GETTER(unsigned int, parentcount, (unsigned int)git_array_size(commit->parent_ids))
+GIT_COMMIT_GETTER(const git_oid *, tree_id, &commit->tree_id)
+
+const char *git_commit_message(const git_commit *commit)
+{
+	const char *message;
+
+	assert(commit);
+
+	message = commit->raw_message;
+
+	/* trim leading newlines from raw message */
+	while (*message && *message == '\n')
+		++message;
+
+	return message;
+}
+
+const char *git_commit_summary(git_commit *commit)
+{
+	git_buf summary = GIT_BUF_INIT;
+	const char *msg, *space;
+	bool space_contains_newline = false;
+
+	assert(commit);
+
+	if (!commit->summary) {
+		for (msg = git_commit_message(commit), space = NULL; *msg; ++msg) {
+			char next_character = msg[0];
+			/* stop processing at the end of the first paragraph */
+			if (next_character == '\n' && (!msg[1] || msg[1] == '\n'))
+				break;
+			/* record the beginning of contiguous whitespace runs */
+			else if (git__isspace(next_character)) {
+				if(space == NULL) {
+					space = msg;
+					space_contains_newline = false;
+				}
+				space_contains_newline |= next_character == '\n';
+			}
+			/* the next character is non-space */
+			else {
+				/* process any recorded whitespace */
+				if (space) {
+					if(space_contains_newline)
+						git_buf_putc(&summary, ' '); /* if the space contains a newline, collapse to ' ' */
+					else
+						git_buf_put(&summary, space, (msg - space)); /* otherwise copy it */
+					space = NULL;
+				}
+				/* copy the next character */
+				git_buf_putc(&summary, next_character);
+			}
+		}
+
+		commit->summary = git_buf_detach(&summary);
+		if (!commit->summary)
+			commit->summary = git__strdup("");
+	}
+
+	return commit->summary;
+}
+
+const char *git_commit_body(git_commit *commit)
+{
+	const char *msg, *end;
+
+	assert(commit);
+
+	if (!commit->body) {
+		/* search for end of summary */
+		for (msg = git_commit_message(commit); *msg; ++msg)
+			if (msg[0] == '\n' && (!msg[1] || msg[1] == '\n'))
+				break;
+
+		/* trim leading and trailing whitespace */
+		for (; *msg; ++msg)
+			if (!git__isspace(*msg))
+				break;
+		for (end = msg + strlen(msg) - 1; msg <= end; --end)
+			if (!git__isspace(*end))
+				break;
+
+		if (*msg)
+			    commit->body = git__strndup(msg, end - msg + 1);
+	}
+
+	return commit->body;
+}
+
+int git_commit_tree(git_tree **tree_out, const git_commit *commit)
+{
+	assert(commit);
+	return git_tree_lookup(tree_out, commit->object.repo, &commit->tree_id);
+}
+
+const git_oid *git_commit_parent_id(
+	const git_commit *commit, unsigned int n)
+{
+	assert(commit);
+
+	return git_array_get(commit->parent_ids, n);
+}
+
+int git_commit_parent(
+	git_commit **parent, const git_commit *commit, unsigned int n)
+{
+	const git_oid *parent_id;
+	assert(commit);
+
+	parent_id = git_commit_parent_id(commit, n);
+	if (parent_id == NULL) {
+		giterr_set(GITERR_INVALID, "parent %u does not exist", n);
+		return GIT_ENOTFOUND;
+	}
+
+	return git_commit_lookup(parent, commit->object.repo, parent_id);
+}
+
+int git_commit_nth_gen_ancestor(
+	git_commit **ancestor,
+	const git_commit *commit,
+	unsigned int n)
+{
+	git_commit *current, *parent = NULL;
+	int error;
+
+	assert(ancestor && commit);
+
+	if (git_commit_dup(&current, (git_commit *)commit) < 0)
+		return -1;
+
+	if (n == 0) {
+		*ancestor = current;
+		return 0;
+	}
+
+	while (n--) {
+		error = git_commit_parent(&parent, current, 0);
+
+		git_commit_free(current);
+
+		if (error < 0)
+			return error;
+
+		current = parent;
+	}
+
+	*ancestor = parent;
+	return 0;
+}
+
+int git_commit_header_field(git_buf *out, const git_commit *commit, const char *field)
+{
+	const char *eol, *buf = commit->raw_header;
+
+	git_buf_clear(out);
+
+	while ((eol = strchr(buf, '\n'))) {
+		/* We can skip continuations here */
+		if (buf[0] == ' ') {
+			buf = eol + 1;
+			continue;
+		}
+
+		/* Skip until we find the field we're after */
+		if (git__prefixcmp(buf, field)) {
+			buf = eol + 1;
+			continue;
+		}
+
+		buf += strlen(field);
+		/* Check that we're not matching a prefix but the field itself */
+		if (buf[0] != ' ') {
+			buf = eol + 1;
+			continue;
+		}
+
+		buf++; /* skip the SP */
+
+		git_buf_put(out, buf, eol - buf);
+		if (git_buf_oom(out))
+			goto oom;
+
+		/* If the next line starts with SP, it's multi-line, we must continue */
+		while (eol[1] == ' ') {
+			git_buf_putc(out, '\n');
+			buf = eol + 2;
+			eol = strchr(buf, '\n');
+			if (!eol)
+				goto malformed;
+
+			git_buf_put(out, buf, eol - buf);
+		}
+
+		if (git_buf_oom(out))
+			goto oom;
+
+		return 0;
+	}
+
+	giterr_set(GITERR_OBJECT, "no such field '%s'", field);
+	return GIT_ENOTFOUND;
+
+malformed:
+	giterr_set(GITERR_OBJECT, "malformed header");
+	return -1;
+oom:
+	giterr_set_oom();
+	return -1;
+}
+
+int git_commit_extract_signature(git_buf *signature, git_buf *signed_data, git_repository *repo, git_oid *commit_id, const char *field)
+{
+	git_odb_object *obj;
+	git_odb *odb;
+	const char *buf;
+	const char *h, *eol;
+	int error;
+
+	git_buf_clear(signature);
+	git_buf_clear(signed_data);
+
+	if (!field)
+		field = "gpgsig";
+
+	if ((error = git_repository_odb__weakptr(&odb, repo)) < 0)
+		return error;
+
+	if ((error = git_odb_read(&obj, odb, commit_id)) < 0)
+		return error;
+
+	if (obj->cached.type != GIT_OBJ_COMMIT) {
+		giterr_set(GITERR_INVALID, "the requested type does not match the type in ODB");
+		error = GIT_ENOTFOUND;
+		goto cleanup;
+	}
+
+	buf = git_odb_object_data(obj);
+
+	while ((h = strchr(buf, '\n')) && h[1] != '\0') {
+		h++;
+		if (git__prefixcmp(buf, field)) {
+			if (git_buf_put(signed_data, buf, h - buf) < 0)
+				return -1;
+
+			buf = h;
+			continue;
+		}
+
+		h = buf;
+		h += strlen(field);
+		eol = strchr(h, '\n');
+		if (h[0] != ' ') {
+			buf = h;
+			continue;
+		}
+		if (!eol)
+			goto malformed;
+
+		h++; /* skip the SP */
+
+		git_buf_put(signature, h, eol - h);
+		if (git_buf_oom(signature))
+			goto oom;
+
+		/* If the next line starts with SP, it's multi-line, we must continue */
+		while (eol[1] == ' ') {
+			git_buf_putc(signature, '\n');
+			h = eol + 2;
+			eol = strchr(h, '\n');
+			if (!eol)
+				goto malformed;
+
+			git_buf_put(signature, h, eol - h);
+		}
+
+		if (git_buf_oom(signature))
+			goto oom;
+
+		error = git_buf_puts(signed_data, eol+1);
+		git_odb_object_free(obj);
+		return error;
+	}
+
+	giterr_set(GITERR_OBJECT, "this commit is not signed");
+	error = GIT_ENOTFOUND;
+	goto cleanup;
+
+malformed:
+	giterr_set(GITERR_OBJECT, "malformed header");
+	error = -1;
+	goto cleanup;
+oom:
+	giterr_set_oom();
+	error = -1;
+	goto cleanup;
+
+cleanup:
+	git_odb_object_free(obj);
+	git_buf_clear(signature);
+	git_buf_clear(signed_data);
+	return error;
+}
+
+int git_commit_create_buffer(git_buf *out,
+	git_repository *repo,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message,
+	const git_tree *tree,
+	size_t parent_count,
+	const git_commit *parents[])
+{
+	int error;
+	commit_parent_data data = { parent_count, parents, repo };
+	git_array_oid_t parents_arr = GIT_ARRAY_INIT;
+	const git_oid *tree_id;
+
+	assert(tree && git_tree_owner(tree) == repo);
+
+	tree_id = git_tree_id(tree);
+
+	if ((error = validate_tree_and_parents(&parents_arr, repo, tree_id, commit_parent_from_array, &data, NULL, true)) < 0)
+		return error;
+
+	error = git_commit__create_buffer_internal(
+		out, author, committer,
+		message_encoding, message, tree_id,
+		&parents_arr);
+
+	git_array_clear(parents_arr);
+	return error;
+}
+
+/**
+ * Append to 'out' properly marking continuations when there's a newline in 'content'
+ */
+static void format_header_field(git_buf *out, const char *field, const char *content)
+{
+	const char *lf;
+
+	assert(out && field && content);
+
+	git_buf_puts(out, field);
+	git_buf_putc(out, ' ');
+
+	while ((lf = strchr(content, '\n')) != NULL) {
+		git_buf_put(out, content, lf - content);
+		git_buf_puts(out, "\n ");
+		content = lf + 1;
+	}
+
+	git_buf_puts(out, content);
+	git_buf_putc(out, '\n');
+}
+
+int git_commit_create_with_signature(
+	git_oid *out,
+	git_repository *repo,
+	const char *commit_content,
+	const char *signature,
+	const char *signature_field)
+{
+	git_odb *odb;
+	int error = 0;
+	const char *field;
+	const char *header_end;
+	git_buf commit = GIT_BUF_INIT;
+
+	/* We start by identifying the end of the commit header */
+	header_end = strstr(commit_content, "\n\n");
+	if (!header_end) {
+		giterr_set(GITERR_INVALID, "malformed commit contents");
+		return -1;
+	}
+
+	field = signature_field ? signature_field : "gpgsig";
+
+	/* The header ends after the first LF */
+	header_end++;
+	git_buf_put(&commit, commit_content, header_end - commit_content);
+	format_header_field(&commit, field, signature);
+	git_buf_puts(&commit, header_end);
+
+	if (git_buf_oom(&commit))
+		return -1;
+
+	if ((error = git_repository_odb__weakptr(&odb, repo)) < 0)
+		goto cleanup;
+
+	if ((error = git_odb_write(out, odb, commit.ptr, commit.size, GIT_OBJ_COMMIT)) < 0)
+		goto cleanup;
+
+cleanup:
+	git_buf_free(&commit);
+	return error;
+}

vendor/libgit2-sys/libgit2/src/commit.h

diff --git a/vendor/libgit2-sys/libgit2/src/commit.h b/vendor/libgit2-sys/libgit2/src/commit.h
new file mode 100644
index 0000000..781809d
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/commit.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_commit_h__
+#define INCLUDE_commit_h__
+
+#include "common.h"
+
+#include "git2/commit.h"
+#include "tree.h"
+#include "repository.h"
+#include "array.h"
+
+#include <time.h>
+
+struct git_commit {
+	git_object object;
+
+	git_array_t(git_oid) parent_ids;
+	git_oid tree_id;
+
+	git_signature *author;
+	git_signature *committer;
+
+	char *message_encoding;
+	char *raw_message;
+	char *raw_header;
+
+	char *summary;
+	char *body;
+};
+
+void git_commit__free(void *commit);
+int git_commit__parse(void *commit, git_odb_object *obj);
+
+#endif

vendor/libgit2-sys/libgit2/src/commit_list.c

diff --git a/vendor/libgit2-sys/libgit2/src/commit_list.c b/vendor/libgit2-sys/libgit2/src/commit_list.c
new file mode 100644
index 0000000..96bd9dc
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/commit_list.c
@@ -0,0 +1,205 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "commit_list.h"
+
+#include "revwalk.h"
+#include "pool.h"
+#include "odb.h"
+
+int git_commit_list_time_cmp(const void *a, const void *b)
+{
+	int64_t time_a = ((git_commit_list_node *) a)->time;
+	int64_t time_b = ((git_commit_list_node *) b)->time;
+
+	if (time_a < time_b)
+		return 1;
+	if (time_a > time_b)
+		return -1;
+
+	return 0;
+}
+
+git_commit_list *git_commit_list_insert(git_commit_list_node *item, git_commit_list **list_p)
+{
+	git_commit_list *new_list = git__malloc(sizeof(git_commit_list));
+	if (new_list != NULL) {
+		new_list->item = item;
+		new_list->next = *list_p;
+	}
+	*list_p = new_list;
+	return new_list;
+}
+
+git_commit_list *git_commit_list_insert_by_date(git_commit_list_node *item, git_commit_list **list_p)
+{
+	git_commit_list **pp = list_p;
+	git_commit_list *p;
+
+	while ((p = *pp) != NULL) {
+		if (git_commit_list_time_cmp(p->item, item) > 0)
+			break;
+
+		pp = &p->next;
+	}
+
+	return git_commit_list_insert(item, pp);
+}
+
+git_commit_list_node *git_commit_list_alloc_node(git_revwalk *walk)
+{
+	return (git_commit_list_node *)git_pool_mallocz(&walk->commit_pool, 1);
+}
+
+static int commit_error(git_commit_list_node *commit, const char *msg)
+{
+	char commit_oid[GIT_OID_HEXSZ + 1];
+	git_oid_fmt(commit_oid, &commit->oid);
+	commit_oid[GIT_OID_HEXSZ] = '\0';
+
+	giterr_set(GITERR_ODB, "failed to parse commit %s - %s", commit_oid, msg);
+
+	return -1;
+}
+
+static git_commit_list_node **alloc_parents(
+	git_revwalk *walk, git_commit_list_node *commit, size_t n_parents)
+{
+	if (n_parents <= PARENTS_PER_COMMIT)
+		return (git_commit_list_node **)((char *)commit + sizeof(git_commit_list_node));
+
+	return (git_commit_list_node **)git_pool_malloc(
+		&walk->commit_pool, (uint32_t)(n_parents * sizeof(git_commit_list_node *)));
+}
+
+
+void git_commit_list_free(git_commit_list **list_p)
+{
+	git_commit_list *list = *list_p;
+
+	if (list == NULL)
+		return;
+
+	while (list) {
+		git_commit_list *temp = list;
+		list = temp->next;
+		git__free(temp);
+	}
+
+	*list_p = NULL;
+}
+
+git_commit_list_node *git_commit_list_pop(git_commit_list **stack)
+{
+	git_commit_list *top = *stack;
+	git_commit_list_node *item = top ? top->item : NULL;
+
+	if (top) {
+		*stack = top->next;
+		git__free(top);
+	}
+	return item;
+}
+
+static int commit_quick_parse(
+	git_revwalk *walk,
+	git_commit_list_node *commit,
+	const uint8_t *buffer,
+	size_t buffer_len)
+{
+	const size_t parent_len = strlen("parent ") + GIT_OID_HEXSZ + 1;
+	const uint8_t *buffer_end = buffer + buffer_len;
+	const uint8_t *parents_start, *committer_start;
+	int i, parents = 0;
+	int64_t commit_time;
+
+	buffer += strlen("tree ") + GIT_OID_HEXSZ + 1;
+
+	parents_start = buffer;
+	while (buffer + parent_len < buffer_end && memcmp(buffer, "parent ", strlen("parent ")) == 0) {
+		parents++;
+		buffer += parent_len;
+	}
+
+	commit->parents = alloc_parents(walk, commit, parents);
+	GITERR_CHECK_ALLOC(commit->parents);
+
+	buffer = parents_start;
+	for (i = 0; i < parents; ++i) {
+		git_oid oid;
+
+		if (git_oid_fromstr(&oid, (const char *)buffer + strlen("parent ")) < 0)
+			return -1;
+
+		commit->parents[i] = git_revwalk__commit_lookup(walk, &oid);
+		if (commit->parents[i] == NULL)
+			return -1;
+
+		buffer += parent_len;
+	}
+
+	commit->out_degree = (unsigned short)parents;
+
+	if ((committer_start = buffer = memchr(buffer, '\n', buffer_end - buffer)) == NULL)
+		return commit_error(commit, "object is corrupted");
+
+	buffer++;
+
+	if ((buffer = memchr(buffer, '\n', buffer_end - buffer)) == NULL)
+		return commit_error(commit, "object is corrupted");
+
+	/* Skip trailing spaces */
+	while (buffer > committer_start && git__isspace(*buffer))
+		buffer--;
+
+	/* Seek for the beginning of the pack of digits */
+	while (buffer > committer_start && git__isdigit(*buffer))
+		buffer--;
+
+	/* Skip potential timezone offset */
+	if ((buffer > committer_start) && (*buffer == '+' || *buffer == '-')) {
+		buffer--;
+
+		while (buffer > committer_start && git__isspace(*buffer))
+			buffer--;
+
+		while (buffer > committer_start && git__isdigit(*buffer))
+			buffer--;
+	}
+
+	if ((buffer == committer_start) || (git__strtol64(&commit_time, (char *)(buffer + 1), NULL, 10) < 0))
+		return commit_error(commit, "cannot parse commit time");
+
+	commit->time = commit_time;
+	commit->parsed = 1;
+	return 0;
+}
+
+int git_commit_list_parse(git_revwalk *walk, git_commit_list_node *commit)
+{
+	git_odb_object *obj;
+	int error;
+
+	if (commit->parsed)
+		return 0;
+
+	if ((error = git_odb_read(&obj, walk->odb, &commit->oid)) < 0)
+		return error;
+
+	if (obj->cached.type != GIT_OBJ_COMMIT) {
+		giterr_set(GITERR_INVALID, "object is no commit object");
+		error = -1;
+	} else
+		error = commit_quick_parse(
+			walk, commit,
+			(const uint8_t *)git_odb_object_data(obj),
+			git_odb_object_size(obj));
+
+	git_odb_object_free(obj);
+	return error;
+}
+

vendor/libgit2-sys/libgit2/src/commit_list.h

diff --git a/vendor/libgit2-sys/libgit2/src/commit_list.h b/vendor/libgit2-sys/libgit2/src/commit_list.h
new file mode 100644
index 0000000..a7551a2
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/commit_list.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_commit_list_h__
+#define INCLUDE_commit_list_h__
+
+#include "common.h"
+
+#include "git2/oid.h"
+
+#define PARENT1  (1 << 0)
+#define PARENT2  (1 << 1)
+#define RESULT   (1 << 2)
+#define STALE    (1 << 3)
+#define ALL_FLAGS (PARENT1 | PARENT2 | STALE | RESULT)
+
+#define PARENTS_PER_COMMIT	2
+#define COMMIT_ALLOC \
+	(sizeof(git_commit_list_node) + PARENTS_PER_COMMIT * sizeof(git_commit_list_node *))
+
+#define FLAG_BITS 4
+
+typedef struct git_commit_list_node {
+	git_oid oid;
+	int64_t time;
+	unsigned int seen:1,
+			 uninteresting:1,
+			 topo_delay:1,
+			 parsed:1,
+			 added:1,
+			 flags : FLAG_BITS;
+
+	unsigned short in_degree;
+	unsigned short out_degree;
+
+	struct git_commit_list_node **parents;
+} git_commit_list_node;
+
+typedef struct git_commit_list {
+	git_commit_list_node *item;
+	struct git_commit_list *next;
+} git_commit_list;
+
+git_commit_list_node *git_commit_list_alloc_node(git_revwalk *walk);
+int git_commit_list_time_cmp(const void *a, const void *b);
+void git_commit_list_free(git_commit_list **list_p);
+git_commit_list *git_commit_list_insert(git_commit_list_node *item, git_commit_list **list_p);
+git_commit_list *git_commit_list_insert_by_date(git_commit_list_node *item, git_commit_list **list_p);
+int git_commit_list_parse(git_revwalk *walk, git_commit_list_node *commit);
+git_commit_list_node *git_commit_list_pop(git_commit_list **stack);
+
+#endif

vendor/libgit2-sys/libgit2/src/common.h

diff --git a/vendor/libgit2-sys/libgit2/src/common.h b/vendor/libgit2-sys/libgit2/src/common.h
new file mode 100644
index 0000000..44063be
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/common.h
@@ -0,0 +1,247 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_common_h__
+#define INCLUDE_common_h__
+
+#ifndef LIBGIT2_NO_FEATURES_H
+# include "git2/sys/features.h"
+#endif
+
+#include "git2/common.h"
+#include "cc-compat.h"
+
+/** Declare a function as always inlined. */
+#if defined(_MSC_VER)
+# define GIT_INLINE(type) static __inline type
+#else
+# define GIT_INLINE(type) static inline type
+#endif
+
+/** Support for gcc/clang __has_builtin intrinsic */
+#ifndef __has_builtin
+# define __has_builtin(x) 0
+#endif
+
+#include <assert.h>
+#include <errno.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#ifdef GIT_WIN32
+
+# include <io.h>
+# include <direct.h>
+# include <winsock2.h>
+# include <windows.h>
+# include <ws2tcpip.h>
+# include "win32/msvc-compat.h"
+# include "win32/mingw-compat.h"
+# include "win32/win32-compat.h"
+# include "win32/error.h"
+# include "win32/version.h"
+# ifdef GIT_THREADS
+#	include "win32/thread.h"
+# endif
+
+#else
+
+# include <unistd.h>
+# include <strings.h>
+# ifdef GIT_THREADS
+#	include <pthread.h>
+#	include <sched.h>
+# endif
+#define GIT_STDLIB_CALL
+
+#ifdef GIT_USE_STAT_ATIMESPEC
+# define st_atim st_atimespec
+# define st_ctim st_ctimespec
+# define st_mtim st_mtimespec
+#endif
+
+# include <arpa/inet.h>
+
+#endif
+
+#include "git2/types.h"
+#include "git2/errors.h"
+#include "thread-utils.h"
+#include "integer.h"
+
+#include <regex.h>
+
+#define DEFAULT_BUFSIZE 65536
+#define FILEIO_BUFSIZE DEFAULT_BUFSIZE
+#define FILTERIO_BUFSIZE DEFAULT_BUFSIZE
+#define NETIO_BUFSIZE DEFAULT_BUFSIZE
+
+/**
+ * Check a pointer allocation result, returning -1 if it failed.
+ */
+#define GITERR_CHECK_ALLOC(ptr) if (ptr == NULL) { return -1; }
+
+/**
+ * Check a buffer allocation result, returning -1 if it failed.
+ */
+#define GITERR_CHECK_ALLOC_BUF(buf) if ((void *)(buf) == NULL || git_buf_oom(buf)) { return -1; }
+
+/**
+ * Check a return value and propagate result if non-zero.
+ */
+#define GITERR_CHECK_ERROR(code) \
+	do { int _err = (code); if (_err) return _err; } while (0)
+
+/**
+ * Set the error message for this thread, formatting as needed.
+ */
+
+void giterr_set(int error_class, const char *string, ...) GIT_FORMAT_PRINTF(2, 3);
+
+/**
+ * Set the error message for a regex failure, using the internal regex
+ * error code lookup and return a libgit error code.
+ */
+int giterr_set_regex(const regex_t *regex, int error_code);
+
+/**
+ * Set error message for user callback if needed.
+ *
+ * If the error code in non-zero and no error message is set, this
+ * sets a generic error message.
+ *
+ * @return This always returns the `error_code` parameter.
+ */
+GIT_INLINE(int) giterr_set_after_callback_function(
+	int error_code, const char *action)
+{
+	if (error_code) {
+		const git_error *e = giterr_last();
+		if (!e || !e->message)
+			giterr_set(e ? e->klass : GITERR_CALLBACK,
+				"%s callback returned %d", action, error_code);
+	}
+	return error_code;
+}
+
+#ifdef GIT_WIN32
+#define giterr_set_after_callback(code) \
+	giterr_set_after_callback_function((code), __FUNCTION__)
+#else
+#define giterr_set_after_callback(code) \
+	giterr_set_after_callback_function((code), __func__)
+#endif
+
+/**
+ * Gets the system error code for this thread.
+ */
+int giterr_system_last(void);
+
+/**
+ * Sets the system error code for this thread.
+ */
+void giterr_system_set(int code);
+
+/**
+ * Structure to preserve libgit2 error state
+ */
+typedef struct {
+	int error_code;
+	unsigned int oom : 1;
+	git_error error_msg;
+} git_error_state;
+
+/**
+ * Capture current error state to restore later, returning error code.
+ * If `error_code` is zero, this does not clear the current error state.
+ * You must either restore this error state, or free it.
+ */
+extern int giterr_state_capture(git_error_state *state, int error_code);
+
+/**
+ * Restore error state to a previous value, returning saved error code.
+ */
+extern int giterr_state_restore(git_error_state *state);
+
+/** Free an error state. */
+extern void giterr_state_free(git_error_state *state);
+
+/**
+ * Check a versioned structure for validity
+ */
+GIT_INLINE(int) giterr__check_version(const void *structure, unsigned int expected_max, const char *name)
+{
+	unsigned int actual;
+
+	if (!structure)
+		return 0;
+
+	actual = *(const unsigned int*)structure;
+	if (actual > 0 && actual <= expected_max)
+		return 0;
+
+	giterr_set(GITERR_INVALID, "invalid version %d on %s", actual, name);
+	return -1;
+}
+#define GITERR_CHECK_VERSION(S,V,N) if (giterr__check_version(S,V,N) < 0) return -1
+
+/**
+ * Initialize a structure with a version.
+ */
+GIT_INLINE(void) git__init_structure(void *structure, size_t len, unsigned int version)
+{
+	memset(structure, 0, len);
+	*((int*)structure) = version;
+}
+#define GIT_INIT_STRUCTURE(S,V) git__init_structure(S, sizeof(*S), V)
+
+#define GIT_INIT_STRUCTURE_FROM_TEMPLATE(PTR,VERSION,TYPE,TPL) do { \
+	TYPE _tmpl = TPL; \
+	GITERR_CHECK_VERSION(&(VERSION), _tmpl.version, #TYPE);	\
+	memcpy((PTR), &_tmpl, sizeof(_tmpl)); } while (0)
+
+
+/** Check for additive overflow, setting an error if would occur. */
+#define GIT_ADD_SIZET_OVERFLOW(out, one, two) \
+	(git__add_sizet_overflow(out, one, two) ? (giterr_set_oom(), 1) : 0)
+
+/** Check for additive overflow, setting an error if would occur. */
+#define GIT_MULTIPLY_SIZET_OVERFLOW(out, nelem, elsize) \
+	(git__multiply_sizet_overflow(out, nelem, elsize) ? (giterr_set_oom(), 1) : 0)
+
+/** Check for additive overflow, failing if it would occur. */
+#define GITERR_CHECK_ALLOC_ADD(out, one, two) \
+	if (GIT_ADD_SIZET_OVERFLOW(out, one, two)) { return -1; }
+
+#define GITERR_CHECK_ALLOC_ADD3(out, one, two, three) \
+	if (GIT_ADD_SIZET_OVERFLOW(out, one, two) || \
+		GIT_ADD_SIZET_OVERFLOW(out, *(out), three)) { return -1; }
+
+#define GITERR_CHECK_ALLOC_ADD4(out, one, two, three, four) \
+	if (GIT_ADD_SIZET_OVERFLOW(out, one, two) || \
+		GIT_ADD_SIZET_OVERFLOW(out, *(out), three) || \
+		GIT_ADD_SIZET_OVERFLOW(out, *(out), four)) { return -1; }
+
+#define GITERR_CHECK_ALLOC_ADD5(out, one, two, three, four, five) \
+	if (GIT_ADD_SIZET_OVERFLOW(out, one, two) || \
+		GIT_ADD_SIZET_OVERFLOW(out, *(out), three) || \
+		GIT_ADD_SIZET_OVERFLOW(out, *(out), four) || \
+		GIT_ADD_SIZET_OVERFLOW(out, *(out), five)) { return -1; }
+
+/** Check for multiplicative overflow, failing if it would occur. */
+#define GITERR_CHECK_ALLOC_MULTIPLY(out, nelem, elsize) \
+	if (GIT_MULTIPLY_SIZET_OVERFLOW(out, nelem, elsize)) { return -1; }
+
+/* NOTE: other giterr functions are in the public errors.h header file */
+
+#include "util.h"
+
+#endif

vendor/libgit2-sys/libgit2/src/config.c

diff --git a/vendor/libgit2-sys/libgit2/src/config.c b/vendor/libgit2-sys/libgit2/src/config.c
new file mode 100644
index 0000000..1bc11b9
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/config.c
@@ -0,0 +1,1492 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "config.h"
+
+#include "sysdir.h"
+#include "git2/config.h"
+#include "git2/sys/config.h"
+#include "vector.h"
+#include "buf_text.h"
+#include "config_file.h"
+#include "transaction.h"
+#if GIT_WIN32
+# include <windows.h>
+#endif
+
+#include <ctype.h>
+
+void git_config_entry_free(git_config_entry *entry)
+{
+	if (!entry)
+		return;
+
+	entry->free(entry);
+}
+
+typedef struct {
+	git_refcount rc;
+
+	git_config_backend *file;
+	git_config_level_t level;
+} file_internal;
+
+static void file_internal_free(file_internal *internal)
+{
+	git_config_backend *file;
+
+	file = internal->file;
+	file->free(file);
+	git__free(internal);
+}
+
+static void config_free(git_config *cfg)
+{
+	size_t i;
+	file_internal *internal;
+
+	for (i = 0; i < cfg->files.length; ++i) {
+		internal = git_vector_get(&cfg->files, i);
+		GIT_REFCOUNT_DEC(internal, file_internal_free);
+	}
+
+	git_vector_free(&cfg->files);
+
+	git__memzero(cfg, sizeof(*cfg));
+	git__free(cfg);
+}
+
+void git_config_free(git_config *cfg)
+{
+	if (cfg == NULL)
+		return;
+
+	GIT_REFCOUNT_DEC(cfg, config_free);
+}
+
+static int config_backend_cmp(const void *a, const void *b)
+{
+	const file_internal *bk_a = (const file_internal *)(a);
+	const file_internal *bk_b = (const file_internal *)(b);
+
+	return bk_b->level - bk_a->level;
+}
+
+int git_config_new(git_config **out)
+{
+	git_config *cfg;
+
+	cfg = git__malloc(sizeof(git_config));
+	GITERR_CHECK_ALLOC(cfg);
+
+	memset(cfg, 0x0, sizeof(git_config));
+
+	if (git_vector_init(&cfg->files, 3, config_backend_cmp) < 0) {
+		git__free(cfg);
+		return -1;
+	}
+
+	*out = cfg;
+	GIT_REFCOUNT_INC(cfg);
+	return 0;
+}
+
+int git_config_add_file_ondisk(
+	git_config *cfg,
+	const char *path,
+	git_config_level_t level,
+	const git_repository *repo,
+	int force)
+{
+	git_config_backend *file = NULL;
+	struct stat st;
+	int res;
+
+	assert(cfg && path);
+
+	res = p_stat(path, &st);
+	if (res < 0 && errno != ENOENT) {
+		giterr_set(GITERR_CONFIG, "failed to stat '%s'", path);
+		return -1;
+	}
+
+	if (git_config_file__ondisk(&file, path) < 0)
+		return -1;
+
+	if ((res = git_config_add_backend(cfg, file, level, repo, force)) < 0) {
+		/*
+		 * free manually; the file is not owned by the config
+		 * instance yet and will not be freed on cleanup
+		 */
+		file->free(file);
+		return res;
+	}
+
+	return 0;
+}
+
+int git_config_open_ondisk(git_config **out, const char *path)
+{
+	int error;
+	git_config *config;
+
+	*out = NULL;
+
+	if (git_config_new(&config) < 0)
+		return -1;
+
+	if ((error = git_config_add_file_ondisk(config, path, GIT_CONFIG_LEVEL_LOCAL, NULL, 0)) < 0)
+		git_config_free(config);
+	else
+		*out = config;
+
+	return error;
+}
+
+int git_config_snapshot(git_config **out, git_config *in)
+{
+	int error = 0;
+	size_t i;
+	file_internal *internal;
+	git_config *config;
+
+	*out = NULL;
+
+	if (git_config_new(&config) < 0)
+		return -1;
+
+	git_vector_foreach(&in->files, i, internal) {
+		git_config_backend *b;
+
+		if ((error = internal->file->snapshot(&b, internal->file)) < 0)
+			break;
+
+		if ((error = git_config_add_backend(config, b, internal->level, NULL, 0)) < 0) {
+			b->free(b);
+			break;
+		}
+	}
+
+	if (error < 0)
+		git_config_free(config);
+	else
+		*out = config;
+
+	return error;
+}
+
+static int find_internal_file_by_level(
+	file_internal **internal_out,
+	const git_config *cfg,
+	git_config_level_t level)
+{
+	int pos = -1;
+	file_internal *internal;
+	size_t i;
+
+	/* when passing GIT_CONFIG_HIGHEST_LEVEL, the idea is to get the config file
+	 * which has the highest level. As config files are stored in a vector
+	 * sorted by decreasing order of level, getting the file at position 0
+	 * will do the job.
+	 */
+	if (level == GIT_CONFIG_HIGHEST_LEVEL) {
+		pos = 0;
+	} else {
+		git_vector_foreach(&cfg->files, i, internal) {
+			if (internal->level == level)
+				pos = (int)i;
+		}
+	}
+
+	if (pos == -1) {
+		giterr_set(GITERR_CONFIG,
+			"no config file exists for the given level '%i'", (int)level);
+		return GIT_ENOTFOUND;
+	}
+
+	*internal_out = git_vector_get(&cfg->files, pos);
+
+	return 0;
+}
+
+static int duplicate_level(void **old_raw, void *new_raw)
+{
+	file_internal **old = (file_internal **)old_raw;
+
+	GIT_UNUSED(new_raw);
+
+	giterr_set(GITERR_CONFIG, "a file with the same level (%i) has already been added to the config", (int)(*old)->level);
+	return GIT_EEXISTS;
+}
+
+static void try_remove_existing_file_internal(
+	git_config *cfg,
+	git_config_level_t level)
+{
+	int pos = -1;
+	file_internal *internal;
+	size_t i;
+
+	git_vector_foreach(&cfg->files, i, internal) {
+		if (internal->level == level)
+			pos = (int)i;
+	}
+
+	if (pos == -1)
+		return;
+
+	internal = git_vector_get(&cfg->files, pos);
+
+	if (git_vector_remove(&cfg->files, pos) < 0)
+		return;
+
+	GIT_REFCOUNT_DEC(internal, file_internal_free);
+}
+
+static int git_config__add_internal(
+	git_config *cfg,
+	file_internal *internal,
+	git_config_level_t level,
+	int force)
+{
+	int result;
+
+	/* delete existing config file for level if it exists */
+	if (force)
+		try_remove_existing_file_internal(cfg, level);
+
+	if ((result = git_vector_insert_sorted(&cfg->files,
+			internal, &duplicate_level)) < 0)
+		return result;
+
+	git_vector_sort(&cfg->files);
+	internal->file->cfg = cfg;
+
+	GIT_REFCOUNT_INC(internal);
+
+	return 0;
+}
+
+int git_config_open_global(git_config **cfg_out, git_config *cfg)
+{
+	if (!git_config_open_level(cfg_out, cfg, GIT_CONFIG_LEVEL_XDG))
+		return 0;
+
+	return git_config_open_level(cfg_out, cfg, GIT_CONFIG_LEVEL_GLOBAL);
+}
+
+int git_config_open_level(
+	git_config **cfg_out,
+	const git_config *cfg_parent,
+	git_config_level_t level)
+{
+	git_config *cfg;
+	file_internal *internal;
+	int res;
+
+	if ((res = find_internal_file_by_level(&internal, cfg_parent, level)) < 0)
+		return res;
+
+	if ((res = git_config_new(&cfg)) < 0)
+		return res;
+
+	if ((res = git_config__add_internal(cfg, internal, level, true)) < 0) {
+		git_config_free(cfg);
+		return res;
+	}
+
+	*cfg_out = cfg;
+
+	return 0;
+}
+
+int git_config_add_backend(
+	git_config *cfg,
+	git_config_backend *file,
+	git_config_level_t level,
+	const git_repository *repo,
+	int force)
+{
+	file_internal *internal;
+	int result;
+
+	assert(cfg && file);
+
+	GITERR_CHECK_VERSION(file, GIT_CONFIG_BACKEND_VERSION, "git_config_backend");
+
+	if ((result = file->open(file, level, repo)) < 0)
+		return result;
+
+	internal = git__malloc(sizeof(file_internal));
+	GITERR_CHECK_ALLOC(internal);
+
+	memset(internal, 0x0, sizeof(file_internal));
+
+	internal->file = file;
+	internal->level = level;
+
+	if ((result = git_config__add_internal(cfg, internal, level, force)) < 0) {
+		git__free(internal);
+		return result;
+	}
+
+	return 0;
+}
+
+/*
+ * Loop over all the variables
+ */
+
+typedef struct {
+	git_config_iterator parent;
+	git_config_iterator *current;
+	const git_config *cfg;
+	regex_t regex;
+	size_t i;
+} all_iter;
+
+static int find_next_backend(size_t *out, const git_config *cfg, size_t i)
+{
+	file_internal *internal;
+
+	for (; i > 0; --i) {
+		internal = git_vector_get(&cfg->files, i - 1);
+		if (!internal || !internal->file)
+			continue;
+
+		*out = i;
+		return 0;
+	}
+
+	return -1;
+}
+
+static int all_iter_next(git_config_entry **entry, git_config_iterator *_iter)
+{
+	all_iter *iter = (all_iter *) _iter;
+	file_internal *internal;
+	git_config_backend *backend;
+	size_t i;
+	int error = 0;
+
+	if (iter->current != NULL &&
+	    (error = iter->current->next(entry, iter->current)) == 0) {
+		return 0;
+	}
+
+	if (error < 0 && error != GIT_ITEROVER)
+		return error;
+
+	do {
+		if (find_next_backend(&i, iter->cfg, iter->i) < 0)
+			return GIT_ITEROVER;
+
+		internal = git_vector_get(&iter->cfg->files, i - 1);
+		backend = internal->file;
+		iter->i = i - 1;
+
+		if (iter->current)
+			iter->current->free(iter->current);
+
+		iter->current = NULL;
+		error = backend->iterator(&iter->current, backend);
+		if (error == GIT_ENOTFOUND)
+			continue;
+
+		if (error < 0)
+			return error;
+
+		error = iter->current->next(entry, iter->current);
+		/* If this backend is empty, then keep going */
+		if (error == GIT_ITEROVER)
+			continue;
+
+		return error;
+
+	} while(1);
+
+	return GIT_ITEROVER;
+}
+
+static int all_iter_glob_next(git_config_entry **entry, git_config_iterator *_iter)
+{
+	int error;
+	all_iter *iter = (all_iter *) _iter;
+
+	/*
+	 * We use the "normal" function to grab the next one across
+	 * backends and then apply the regex
+	 */
+	while ((error = all_iter_next(entry, _iter)) == 0) {
+		/* skip non-matching keys if regexp was provided */
+		if (regexec(&iter->regex, (*entry)->name, 0, NULL, 0) != 0)
+			continue;
+
+		/* and simply return if we like the entry's name */
+		return 0;
+	}
+
+	return error;
+}
+
+static void all_iter_free(git_config_iterator *_iter)
+{
+	all_iter *iter = (all_iter *) _iter;
+
+	if (iter->current)
+		iter->current->free(iter->current);
+
+	git__free(iter);
+}
+
+static void all_iter_glob_free(git_config_iterator *_iter)
+{
+	all_iter *iter = (all_iter *) _iter;
+
+	regfree(&iter->regex);
+	all_iter_free(_iter);
+}
+
+int git_config_iterator_new(git_config_iterator **out, const git_config *cfg)
+{
+	all_iter *iter;
+
+	iter = git__calloc(1, sizeof(all_iter));
+	GITERR_CHECK_ALLOC(iter);
+
+	iter->parent.free = all_iter_free;
+	iter->parent.next = all_iter_next;
+
+	iter->i = cfg->files.length;
+	iter->cfg = cfg;
+
+	*out = (git_config_iterator *) iter;
+
+	return 0;
+}
+
+int git_config_iterator_glob_new(git_config_iterator **out, const git_config *cfg, const char *regexp)
+{
+	all_iter *iter;
+	int result;
+
+	if (regexp == NULL)
+		return git_config_iterator_new(out, cfg);
+
+	iter = git__calloc(1, sizeof(all_iter));
+	GITERR_CHECK_ALLOC(iter);
+
+	if ((result = p_regcomp(&iter->regex, regexp, REG_EXTENDED)) != 0) {
+		giterr_set_regex(&iter->regex, result);
+		git__free(iter);
+		return -1;
+	}
+
+	iter->parent.next = all_iter_glob_next;
+	iter->parent.free = all_iter_glob_free;
+	iter->i = cfg->files.length;
+	iter->cfg = cfg;
+
+	*out = (git_config_iterator *) iter;
+
+	return 0;
+}
+
+int git_config_foreach(
+	const git_config *cfg, git_config_foreach_cb cb, void *payload)
+{
+	return git_config_foreach_match(cfg, NULL, cb, payload);
+}
+
+int git_config_backend_foreach_match(
+	git_config_backend *backend,
+	const char *regexp,
+	git_config_foreach_cb cb,
+	void *payload)
+{
+	git_config_entry *entry;
+	git_config_iterator* iter;
+	regex_t regex;
+	int error = 0;
+
+	if (regexp != NULL) {
+		if ((error = p_regcomp(&regex, regexp, REG_EXTENDED)) != 0) {
+			giterr_set_regex(&regex, error);
+			regfree(&regex);
+			return -1;
+		}
+	}
+
+	if ((error = backend->iterator(&iter, backend)) < 0) {
+		iter = NULL;
+		return -1;
+	}
+
+	while (!(iter->next(&entry, iter) < 0)) {
+		/* skip non-matching keys if regexp was provided */
+		if (regexp && regexec(&regex, entry->name, 0, NULL, 0) != 0)
+			continue;
+
+		/* abort iterator on non-zero return value */
+		if ((error = cb(entry, payload)) != 0) {
+			giterr_set_after_callback(error);
+			break;
+		}
+	}
+
+	if (regexp != NULL)
+		regfree(&regex);
+
+	iter->free(iter);
+
+	return error;
+}
+
+int git_config_foreach_match(
+	const git_config *cfg,
+	const char *regexp,
+	git_config_foreach_cb cb,
+	void *payload)
+{
+	int error;
+	git_config_iterator *iter;
+	git_config_entry *entry;
+
+	if ((error = git_config_iterator_glob_new(&iter, cfg, regexp)) < 0)
+		return error;
+
+	while (!(error = git_config_next(&entry, iter))) {
+		if ((error = cb(entry, payload)) != 0) {
+			giterr_set_after_callback(error);
+			break;
+		}
+	}
+
+	git_config_iterator_free(iter);
+
+	if (error == GIT_ITEROVER)
+		error = 0;
+
+	return error;
+}
+
+/**************
+ * Setters
+ **************/
+
+typedef enum {
+	BACKEND_USE_SET,
+	BACKEND_USE_DELETE
+} backend_use;
+
+static const char *uses[] = {
+    "set",
+    "delete"
+};
+
+static int get_backend_for_use(git_config_backend **out,
+	git_config *cfg, const char *name, backend_use use)
+{
+	size_t i;
+	file_internal *f;
+
+	*out = NULL;
+
+	if (git_vector_length(&cfg->files) == 0) {
+		giterr_set(GITERR_CONFIG,
+			"cannot %s value for '%s' when no config files exist",
+			uses[use], name);
+		return GIT_ENOTFOUND;
+	}
+
+	git_vector_foreach(&cfg->files, i, f) {
+		if (!f->file->readonly) {
+			*out = f->file;
+			return 0;
+		}
+	}
+
+	giterr_set(GITERR_CONFIG,
+		"cannot %s value for '%s' when all config files are readonly",
+		uses[use], name);
+	return GIT_ENOTFOUND;
+}
+
+int git_config_delete_entry(git_config *cfg, const char *name)
+{
+	git_config_backend *file;
+
+	if (get_backend_for_use(&file, cfg, name, BACKEND_USE_DELETE) < 0)
+		return GIT_ENOTFOUND;
+
+	return file->del(file, name);
+}
+
+int git_config_set_int64(git_config *cfg, const char *name, int64_t value)
+{
+	char str_value[32]; /* All numbers should fit in here */
+	p_snprintf(str_value, sizeof(str_value), "%" PRId64, value);
+	return git_config_set_string(cfg, name, str_value);
+}
+
+int git_config_set_int32(git_config *cfg, const char *name, int32_t value)
+{
+	return git_config_set_int64(cfg, name, (int64_t)value);
+}
+
+int git_config_set_bool(git_config *cfg, const char *name, int value)
+{
+	return git_config_set_string(cfg, name, value ? "true" : "false");
+}
+
+int git_config_set_string(git_config *cfg, const char *name, const char *value)
+{
+	int error;
+	git_config_backend *file;
+
+	if (!value) {
+		giterr_set(GITERR_CONFIG, "the value to set cannot be NULL");
+		return -1;
+	}
+
+	if (get_backend_for_use(&file, cfg, name, BACKEND_USE_SET) < 0)
+		return GIT_ENOTFOUND;
+
+	error = file->set(file, name, value);
+
+	if (!error && GIT_REFCOUNT_OWNER(cfg) != NULL)
+		git_repository__cvar_cache_clear(GIT_REFCOUNT_OWNER(cfg));
+
+	return error;
+}
+
+int git_config__update_entry(
+	git_config *config,
+	const char *key,
+	const char *value,
+	bool overwrite_existing,
+	bool only_if_existing)
+{
+	int error = 0;
+	git_config_entry *ce = NULL;
+
+	if ((error = git_config__lookup_entry(&ce, config, key, false)) < 0)
+		return error;
+
+	if (!ce && only_if_existing) /* entry doesn't exist */
+		return 0;
+	if (ce && !overwrite_existing) /* entry would be overwritten */
+		return 0;
+	if (value && ce && ce->value && !strcmp(ce->value, value)) /* no change */
+		return 0;
+	if (!value && (!ce || !ce->value)) /* asked to delete absent entry */
+		return 0;
+
+	if (!value)
+		error = git_config_delete_entry(config, key);
+	else
+		error = git_config_set_string(config, key, value);
+
+	git_config_entry_free(ce);
+	return error;
+}
+
+/***********
+ * Getters
+ ***********/
+
+static int config_error_notfound(const char *name)
+{
+	giterr_set(GITERR_CONFIG, "config value '%s' was not found", name);
+	return GIT_ENOTFOUND;
+}
+
+enum {
+	GET_ALL_ERRORS = 0,
+	GET_NO_MISSING = 1,
+	GET_NO_ERRORS  = 2
+};
+
+static int get_entry(
+	git_config_entry **out,
+	const git_config *cfg,
+	const char *name,
+	bool normalize_name,
+	int want_errors)
+{
+	int res = GIT_ENOTFOUND;
+	const char *key = name;
+	char *normalized = NULL;
+	size_t i;
+	file_internal *internal;
+
+	*out = NULL;
+
+	if (normalize_name) {
+		if ((res = git_config__normalize_name(name, &normalized)) < 0)
+			goto cleanup;
+		key = normalized;
+	}
+
+	res = GIT_ENOTFOUND;
+	git_vector_foreach(&cfg->files, i, internal) {
+		if (!internal || !internal->file)
+			continue;
+
+		res = internal->file->get(internal->file, key, out);
+		if (res != GIT_ENOTFOUND)
+			break;
+	}
+
+	git__free(normalized);
+
+cleanup:
+	if (res == GIT_ENOTFOUND)
+		res = (want_errors > GET_ALL_ERRORS) ? 0 : config_error_notfound(name);
+	else if (res && (want_errors == GET_NO_ERRORS)) {
+		giterr_clear();
+		res = 0;
+	}
+
+	return res;
+}
+
+int git_config_get_entry(
+	git_config_entry **out, const git_config *cfg, const char *name)
+{
+	return get_entry(out, cfg, name, true, GET_ALL_ERRORS);
+}
+
+int git_config__lookup_entry(
+	git_config_entry **out,
+	const git_config *cfg,
+	const char *key,
+	bool no_errors)
+{
+	return get_entry(
+		out, cfg, key, false, no_errors ? GET_NO_ERRORS : GET_NO_MISSING);
+}
+
+int git_config_get_mapped(
+	int *out,
+	const git_config *cfg,
+	const char *name,
+	const git_cvar_map *maps,
+	size_t map_n)
+{
+	git_config_entry *entry;
+	int ret;
+
+	if ((ret = get_entry(&entry, cfg, name, true, GET_ALL_ERRORS)) < 0)
+		return ret;
+
+	ret = git_config_lookup_map_value(out, maps, map_n, entry->value);
+	git_config_entry_free(entry);
+
+	return ret;
+}
+
+int git_config_get_int64(int64_t *out, const git_config *cfg, const char *name)
+{
+	git_config_entry *entry;
+	int ret;
+
+	if ((ret = get_entry(&entry, cfg, name, true, GET_ALL_ERRORS)) < 0)
+		return ret;
+
+	ret = git_config_parse_int64(out, entry->value);
+	git_config_entry_free(entry);
+
+	return ret;
+}
+
+int git_config_get_int32(int32_t *out, const git_config *cfg, const char *name)
+{
+	git_config_entry *entry;
+	int ret;
+
+	if ((ret = get_entry(&entry, cfg, name, true, GET_ALL_ERRORS)) < 0)
+		return ret;
+
+	ret = git_config_parse_int32(out, entry->value);
+	git_config_entry_free(entry);
+
+	return ret;
+}
+
+int git_config_get_bool(int *out, const git_config *cfg, const char *name)
+{
+	git_config_entry *entry;
+	int ret;
+
+	if ((ret = get_entry(&entry, cfg, name, true, GET_ALL_ERRORS)) < 0)
+		return ret;
+
+	ret = git_config_parse_bool(out, entry->value);
+	git_config_entry_free(entry);
+
+	return ret;
+}
+
+static int is_readonly(const git_config *cfg)
+{
+	size_t i;
+	file_internal *internal;
+
+	git_vector_foreach(&cfg->files, i, internal) {
+		if (!internal || !internal->file)
+			continue;
+
+		if (!internal->file->readonly)
+			return 0;
+	}
+
+	return 1;
+}
+
+int git_config_get_path(git_buf *out, const git_config *cfg, const char *name)
+{
+	git_config_entry *entry;
+	int error;
+
+	if ((error = get_entry(&entry, cfg, name, true, GET_ALL_ERRORS)) < 0)
+		return error;
+
+	 error = git_config_parse_path(out, entry->value);
+	 git_config_entry_free(entry);
+
+	 return error;
+}
+
+int git_config_get_string(
+	const char **out, const git_config *cfg, const char *name)
+{
+	git_config_entry *entry;
+	int ret;
+
+	if (!is_readonly(cfg)) {
+		giterr_set(GITERR_CONFIG, "get_string called on a live config object");
+		return -1;
+	}
+
+	ret = get_entry(&entry, cfg, name, true, GET_ALL_ERRORS);
+	*out = !ret ? (entry->value ? entry->value : "") : NULL;
+
+	git_config_entry_free(entry);
+
+	return ret;
+}
+
+int git_config_get_string_buf(
+	git_buf *out, const git_config *cfg, const char *name)
+{
+	git_config_entry *entry;
+	int ret;
+	const char *str;
+
+	git_buf_sanitize(out);
+
+	ret  = get_entry(&entry, cfg, name, true, GET_ALL_ERRORS);
+	str = !ret ? (entry->value ? entry->value : "") : NULL;
+
+	if (str)
+		ret = git_buf_puts(out, str);
+
+	git_config_entry_free(entry);
+
+	return ret;
+}
+
+char *git_config__get_string_force(
+	const git_config *cfg, const char *key, const char *fallback_value)
+{
+	git_config_entry *entry;
+	char *ret;
+
+	get_entry(&entry, cfg, key, false, GET_NO_ERRORS);
+	ret = (entry && entry->value) ? git__strdup(entry->value) : fallback_value ? git__strdup(fallback_value) : NULL;
+	git_config_entry_free(entry);
+
+	return ret;
+}
+
+int git_config__get_bool_force(
+	const git_config *cfg, const char *key, int fallback_value)
+{
+	int val = fallback_value;
+	git_config_entry *entry;
+
+	get_entry(&entry, cfg, key, false, GET_NO_ERRORS);
+
+	if (entry && git_config_parse_bool(&val, entry->value) < 0)
+		giterr_clear();
+
+	git_config_entry_free(entry);
+	return val;
+}
+
+int git_config__get_int_force(
+	const git_config *cfg, const char *key, int fallback_value)
+{
+	int32_t val = (int32_t)fallback_value;
+	git_config_entry *entry;
+
+	get_entry(&entry, cfg, key, false, GET_NO_ERRORS);
+
+	if (entry && git_config_parse_int32(&val, entry->value) < 0)
+		giterr_clear();
+
+	git_config_entry_free(entry);
+	return (int)val;
+}
+
+int git_config_get_multivar_foreach(
+	const git_config *cfg, const char *name, const char *regexp,
+	git_config_foreach_cb cb, void *payload)
+{
+	int err, found;
+	git_config_iterator *iter;
+	git_config_entry *entry;
+
+	if ((err = git_config_multivar_iterator_new(&iter, cfg, name, regexp)) < 0)
+		return err;
+
+	found = 0;
+	while ((err = iter->next(&entry, iter)) == 0) {
+		found = 1;
+
+		if ((err = cb(entry, payload)) != 0) {
+			giterr_set_after_callback(err);
+			break;
+		}
+	}
+
+	iter->free(iter);
+	if (err == GIT_ITEROVER)
+		err = 0;
+
+	if (found == 0 && err == 0)
+		err = config_error_notfound(name);
+
+	return err;
+}
+
+typedef struct {
+	git_config_iterator parent;
+	git_config_iterator *iter;
+	char *name;
+	regex_t regex;
+	int have_regex;
+} multivar_iter;
+
+static int multivar_iter_next(git_config_entry **entry, git_config_iterator *_iter)
+{
+	multivar_iter *iter = (multivar_iter *) _iter;
+	int error = 0;
+
+	while ((error = iter->iter->next(entry, iter->iter)) == 0) {
+		if (git__strcmp(iter->name, (*entry)->name))
+			continue;
+
+		if (!iter->have_regex)
+			return 0;
+
+		if (regexec(&iter->regex, (*entry)->value, 0, NULL, 0) == 0)
+			return 0;
+	}
+
+	return error;
+}
+
+void multivar_iter_free(git_config_iterator *_iter)
+{
+	multivar_iter *iter = (multivar_iter *) _iter;
+
+	iter->iter->free(iter->iter);
+
+	git__free(iter->name);
+	if (iter->have_regex)
+		regfree(&iter->regex);
+	git__free(iter);
+}
+
+int git_config_multivar_iterator_new(git_config_iterator **out, const git_config *cfg, const char *name, const char *regexp)
+{
+	multivar_iter *iter = NULL;
+	git_config_iterator *inner = NULL;
+	int error;
+
+	if ((error = git_config_iterator_new(&inner, cfg)) < 0)
+		return error;
+
+	iter = git__calloc(1, sizeof(multivar_iter));
+	GITERR_CHECK_ALLOC(iter);
+
+	if ((error = git_config__normalize_name(name, &iter->name)) < 0)
+		goto on_error;
+
+	if (regexp != NULL) {
+		error = p_regcomp(&iter->regex, regexp, REG_EXTENDED);
+		if (error != 0) {
+			giterr_set_regex(&iter->regex, error);
+			error = -1;
+			regfree(&iter->regex);
+			goto on_error;
+		}
+
+		iter->have_regex = 1;
+	}
+
+	iter->iter = inner;
+	iter->parent.free = multivar_iter_free;
+	iter->parent.next = multivar_iter_next;
+
+	*out = (git_config_iterator *) iter;
+
+	return 0;
+
+on_error:
+
+	inner->free(inner);
+	git__free(iter);
+	return error;
+}
+
+int git_config_set_multivar(git_config *cfg, const char *name, const char *regexp, const char *value)
+{
+	git_config_backend *file;
+
+	if (get_backend_for_use(&file, cfg, name, BACKEND_USE_DELETE) < 0)
+		return GIT_ENOTFOUND;
+
+	return file->set_multivar(file, name, regexp, value);
+}
+
+int git_config_delete_multivar(git_config *cfg, const char *name, const char *regexp)
+{
+	git_config_backend *file;
+
+	if (get_backend_for_use(&file, cfg, name, BACKEND_USE_DELETE) < 0)
+		return GIT_ENOTFOUND;
+
+	return file->del_multivar(file, name, regexp);
+}
+
+int git_config_next(git_config_entry **entry, git_config_iterator *iter)
+{
+	return iter->next(entry, iter);
+}
+
+void git_config_iterator_free(git_config_iterator *iter)
+{
+	if (iter == NULL)
+		return;
+
+	iter->free(iter);
+}
+
+int git_config_find_global(git_buf *path)
+{
+	git_buf_sanitize(path);
+	return git_sysdir_find_global_file(path, GIT_CONFIG_FILENAME_GLOBAL);
+}
+
+int git_config_find_xdg(git_buf *path)
+{
+	git_buf_sanitize(path);
+	return git_sysdir_find_xdg_file(path, GIT_CONFIG_FILENAME_XDG);
+}
+
+int git_config_find_system(git_buf *path)
+{
+	git_buf_sanitize(path);
+	return git_sysdir_find_system_file(path, GIT_CONFIG_FILENAME_SYSTEM);
+}
+
+int git_config_find_programdata(git_buf *path)
+{
+	git_buf_sanitize(path);
+	return git_sysdir_find_programdata_file(path, GIT_CONFIG_FILENAME_PROGRAMDATA);
+}
+
+int git_config__global_location(git_buf *buf)
+{
+	const git_buf *paths;
+	const char *sep, *start;
+
+	if (git_sysdir_get(&paths, GIT_SYSDIR_GLOBAL) < 0)
+		return -1;
+
+	/* no paths, so give up */
+	if (!paths || !git_buf_len(paths))
+		return -1;
+
+	/* find unescaped separator or end of string */
+	for (sep = start = git_buf_cstr(paths); *sep; ++sep) {
+		if (*sep == GIT_PATH_LIST_SEPARATOR &&
+			(sep <= start || sep[-1] != '\\'))
+			break;
+	}
+
+	if (git_buf_set(buf, start, (size_t)(sep - start)) < 0)
+		return -1;
+
+	return git_buf_joinpath(buf, buf->ptr, GIT_CONFIG_FILENAME_GLOBAL);
+}
+
+int git_config_open_default(git_config **out)
+{
+	int error;
+	git_config *cfg = NULL;
+	git_buf buf = GIT_BUF_INIT;
+
+	if ((error = git_config_new(&cfg)) < 0)
+		return error;
+
+	if (!git_config_find_global(&buf) || !git_config__global_location(&buf)) {
+		error = git_config_add_file_ondisk(cfg, buf.ptr,
+			GIT_CONFIG_LEVEL_GLOBAL, NULL, 0);
+	}
+
+	if (!error && !git_config_find_xdg(&buf))
+		error = git_config_add_file_ondisk(cfg, buf.ptr,
+			GIT_CONFIG_LEVEL_XDG, NULL, 0);
+
+	if (!error && !git_config_find_system(&buf))
+		error = git_config_add_file_ondisk(cfg, buf.ptr,
+			GIT_CONFIG_LEVEL_SYSTEM, NULL, 0);
+
+	if (!error && !git_config_find_programdata(&buf))
+		error = git_config_add_file_ondisk(cfg, buf.ptr,
+			GIT_CONFIG_LEVEL_PROGRAMDATA, NULL, 0);
+
+	git_buf_free(&buf);
+
+	if (error) {
+		git_config_free(cfg);
+		cfg = NULL;
+	}
+
+	*out = cfg;
+
+	return error;
+}
+
+int git_config_lock(git_transaction **out, git_config *cfg)
+{
+	int error;
+	git_config_backend *file;
+	file_internal *internal;
+
+	internal = git_vector_get(&cfg->files, 0);
+	if (!internal || !internal->file) {
+		giterr_set(GITERR_CONFIG, "cannot lock; the config has no backends/files");
+		return -1;
+	}
+	file = internal->file;
+
+	if ((error = file->lock(file)) < 0)
+		return error;
+
+	return git_transaction_config_new(out, cfg);
+}
+
+int git_config_unlock(git_config *cfg, int commit)
+{
+	git_config_backend *file;
+	file_internal *internal;
+
+	internal = git_vector_get(&cfg->files, 0);
+	if (!internal || !internal->file) {
+		giterr_set(GITERR_CONFIG, "cannot lock; the config has no backends/files");
+		return -1;
+	}
+
+	file = internal->file;
+
+	return file->unlock(file, commit);
+}
+
+/***********
+ * Parsers
+ ***********/
+
+int git_config_lookup_map_value(
+	int *out,
+	const git_cvar_map *maps,
+	size_t map_n,
+	const char *value)
+{
+	size_t i;
+
+	if (!value)
+		goto fail_parse;
+
+	for (i = 0; i < map_n; ++i) {
+		const git_cvar_map *m = maps + i;
+
+		switch (m->cvar_type) {
+		case GIT_CVAR_FALSE:
+		case GIT_CVAR_TRUE: {
+			int bool_val;
+
+			if (git__parse_bool(&bool_val, value) == 0 &&
+				bool_val == (int)m->cvar_type) {
+				*out = m->map_value;
+				return 0;
+			}
+			break;
+		}
+
+		case GIT_CVAR_INT32:
+			if (git_config_parse_int32(out, value) == 0)
+				return 0;
+			break;
+
+		case GIT_CVAR_STRING:
+			if (strcasecmp(value, m->str_match) == 0) {
+				*out = m->map_value;
+				return 0;
+			}
+			break;
+		}
+	}
+
+fail_parse:
+	giterr_set(GITERR_CONFIG, "failed to map '%s'", value);
+	return -1;
+}
+
+int git_config_lookup_map_enum(git_cvar_t *type_out, const char **str_out,
+			       const git_cvar_map *maps, size_t map_n, int enum_val)
+{
+	size_t i;
+
+	for (i = 0; i < map_n; i++) {
+		const git_cvar_map *m = &maps[i];
+
+		if (m->map_value != enum_val)
+			continue;
+
+		*type_out = m->cvar_type;
+		*str_out = m->str_match;
+		return 0;
+	}
+
+	giterr_set(GITERR_CONFIG, "invalid enum value");
+	return GIT_ENOTFOUND;
+}
+
+int git_config_parse_bool(int *out, const char *value)
+{
+	if (git__parse_bool(out, value) == 0)
+		return 0;
+
+	if (git_config_parse_int32(out, value) == 0) {
+		*out = !!(*out);
+		return 0;
+	}
+
+	giterr_set(GITERR_CONFIG, "failed to parse '%s' as a boolean value", value);
+	return -1;
+}
+
+int git_config_parse_int64(int64_t *out, const char *value)
+{
+	const char *num_end;
+	int64_t num;
+
+	if (!value || git__strtol64(&num, value, &num_end, 0) < 0)
+		goto fail_parse;
+
+	switch (*num_end) {
+	case 'g':
+	case 'G':
+		num *= 1024;
+		/* fallthrough */
+
+	case 'm':
+	case 'M':
+		num *= 1024;
+		/* fallthrough */
+
+	case 'k':
+	case 'K':
+		num *= 1024;
+
+		/* check that that there are no more characters after the
+		 * given modifier suffix */
+		if (num_end[1] != '\0')
+			return -1;
+
+		/* fallthrough */
+
+	case '\0':
+		*out = num;
+		return 0;
+
+	default:
+		goto fail_parse;
+	}
+
+fail_parse:
+	giterr_set(GITERR_CONFIG, "failed to parse '%s' as an integer", value ? value : "(null)");
+	return -1;
+}
+
+int git_config_parse_int32(int32_t *out, const char *value)
+{
+	int64_t tmp;
+	int32_t truncate;
+
+	if (git_config_parse_int64(&tmp, value) < 0)
+		goto fail_parse;
+
+	truncate = tmp & 0xFFFFFFFF;
+	if (truncate != tmp)
+		goto fail_parse;
+
+	*out = truncate;
+	return 0;
+
+fail_parse:
+	giterr_set(GITERR_CONFIG, "failed to parse '%s' as a 32-bit integer", value ? value : "(null)");
+	return -1;
+}
+
+int git_config_parse_path(git_buf *out, const char *value)
+{
+	assert(out && value);
+
+	git_buf_sanitize(out);
+
+	if (value[0] == '~') {
+		if (value[1] != '\0' && value[1] != '/') {
+			giterr_set(GITERR_CONFIG, "retrieving a homedir by name is not supported");
+			return -1;
+		}
+
+		return git_sysdir_expand_global_file(out, value[1] ? &value[2] : NULL);
+	}
+
+	return git_buf_sets(out, value);
+}
+
+/* Take something the user gave us and make it nice for our hash function */
+int git_config__normalize_name(const char *in, char **out)
+{
+	char *name, *fdot, *ldot;
+
+	assert(in && out);
+
+	name = git__strdup(in);
+	GITERR_CHECK_ALLOC(name);
+
+	fdot = strchr(name, '.');
+	ldot = strrchr(name, '.');
+
+	if (fdot == NULL || fdot == name || ldot == NULL || !ldot[1])
+		goto invalid;
+
+	/* Validate and downcase up to first dot and after last dot */
+	if (git_config_file_normalize_section(name, fdot) < 0 ||
+		git_config_file_normalize_section(ldot + 1, NULL) < 0)
+		goto invalid;
+
+	/* If there is a middle range, make sure it doesn't have newlines */
+	while (fdot < ldot)
+		if (*fdot++ == '\n')
+			goto invalid;
+
+	*out = name;
+	return 0;
+
+invalid:
+	git__free(name);
+	giterr_set(GITERR_CONFIG, "invalid config item name '%s'", in);
+	return GIT_EINVALIDSPEC;
+}
+
+struct rename_data {
+	git_config *config;
+	git_buf *name;
+	size_t old_len;
+};
+
+static int rename_config_entries_cb(
+	const git_config_entry *entry,
+	void *payload)
+{
+	int error = 0;
+	struct rename_data *data = (struct rename_data *)payload;
+	size_t base_len = git_buf_len(data->name);
+
+	if (base_len > 0 &&
+		!(error = git_buf_puts(data->name, entry->name + data->old_len)))
+	{
+		error = git_config_set_string(
+			data->config, git_buf_cstr(data->name), entry->value);
+
+		git_buf_truncate(data->name, base_len);
+	}
+
+	if (!error)
+		error = git_config_delete_entry(data->config, entry->name);
+
+	return error;
+}
+
+int git_config_rename_section(
+	git_repository *repo,
+	const char *old_section_name,
+	const char *new_section_name)
+{
+	git_config *config;
+	git_buf pattern = GIT_BUF_INIT, replace = GIT_BUF_INIT;
+	int error = 0;
+	struct rename_data data;
+
+	git_buf_text_puts_escape_regex(&pattern, old_section_name);
+
+	if ((error = git_buf_puts(&pattern, "\\..+")) < 0)
+		goto cleanup;
+
+	if ((error = git_repository_config__weakptr(&config, repo)) < 0)
+		goto cleanup;
+
+	data.config  = config;
+	data.name    = &replace;
+	data.old_len = strlen(old_section_name) + 1;
+
+	if ((error = git_buf_join(&replace, '.', new_section_name, "")) < 0)
+		goto cleanup;
+
+	if (new_section_name != NULL &&
+		(error = git_config_file_normalize_section(
+			replace.ptr, strchr(replace.ptr, '.'))) < 0)
+	{
+		giterr_set(
+			GITERR_CONFIG, "invalid config section '%s'", new_section_name);
+		goto cleanup;
+	}
+
+	error = git_config_foreach_match(
+		config, git_buf_cstr(&pattern), rename_config_entries_cb, &data);
+
+cleanup:
+	git_buf_free(&pattern);
+	git_buf_free(&replace);
+
+	return error;
+}
+
+int git_config_init_backend(git_config_backend *backend, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		backend, version, git_config_backend, GIT_CONFIG_BACKEND_INIT);
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/config.h

diff --git a/vendor/libgit2-sys/libgit2/src/config.h b/vendor/libgit2-sys/libgit2/src/config.h
new file mode 100644
index 0000000..a5fcf2e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/config.h
@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_config_h__
+#define INCLUDE_config_h__
+
+#include "common.h"
+
+#include "git2.h"
+#include "git2/config.h"
+#include "vector.h"
+#include "repository.h"
+
+#define GIT_CONFIG_FILENAME_PROGRAMDATA "config"
+#define GIT_CONFIG_FILENAME_SYSTEM "gitconfig"
+#define GIT_CONFIG_FILENAME_GLOBAL ".gitconfig"
+#define GIT_CONFIG_FILENAME_XDG    "config"
+
+#define GIT_CONFIG_FILENAME_INREPO "config"
+#define GIT_CONFIG_FILE_MODE 0666
+
+struct git_config {
+	git_refcount rc;
+	git_vector files;
+};
+
+extern int git_config__global_location(git_buf *buf);
+
+extern int git_config_rename_section(
+	git_repository *repo,
+	const char *old_section_name,	/* eg "branch.dummy" */
+	const char *new_section_name);	/* NULL to drop the old section */
+
+/**
+ * Create a configuration file backend for ondisk files
+ *
+ * These are the normal `.gitconfig` files that Core Git
+ * processes. Note that you first have to add this file to a
+ * configuration object before you can query it for configuration
+ * variables.
+ *
+ * @param out the new backend
+ * @param path where the config file is located
+ */
+extern int git_config_file__ondisk(git_config_backend **out, const char *path);
+
+extern int git_config__normalize_name(const char *in, char **out);
+
+/* internal only: does not normalize key and sets out to NULL if not found */
+extern int git_config__lookup_entry(
+	git_config_entry **out,
+	const git_config *cfg,
+	const char *key,
+	bool no_errors);
+
+/* internal only: update and/or delete entry string with constraints */
+extern int git_config__update_entry(
+	git_config *cfg,
+	const char *key,
+	const char *value,
+	bool overwrite_existing,
+	bool only_if_existing);
+
+/*
+ * Lookup functions that cannot fail.  These functions look up a config
+ * value and return a fallback value if the value is missing or if any
+ * failures occur while trying to access the value.
+ */
+
+extern char *git_config__get_string_force(
+	const git_config *cfg, const char *key, const char *fallback_value);
+
+extern int git_config__get_bool_force(
+	const git_config *cfg, const char *key, int fallback_value);
+
+extern int git_config__get_int_force(
+	const git_config *cfg, const char *key, int fallback_value);
+
+/* API for repository cvar-style lookups from config - not cached, but
+ * uses cvar value maps and fallbacks
+ */
+extern int git_config__cvar(
+	int *out, git_config *config, git_cvar_cached cvar);
+
+/**
+ * The opposite of git_config_lookup_map_value, we take an enum value
+ * and map it to the string or bool value on the config.
+ */
+int git_config_lookup_map_enum(git_cvar_t *type_out, const char **str_out,
+			       const git_cvar_map *maps, size_t map_n, int enum_val);
+
+/**
+ * Unlock the backend with the highest priority
+ *
+ * Unlocking will allow other writers to updat the configuration
+ * file. Optionally, any changes performed since the lock will be
+ * applied to the configuration.
+ *
+ * @param cfg the configuration
+ * @param commit boolean which indicates whether to commit any changes
+ * done since locking
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_config_unlock(git_config *cfg, int commit);
+
+#endif

vendor/libgit2-sys/libgit2/src/config_cache.c

diff --git a/vendor/libgit2-sys/libgit2/src/config_cache.c b/vendor/libgit2-sys/libgit2/src/config_cache.c
new file mode 100644
index 0000000..0efb1a7
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/config_cache.c
@@ -0,0 +1,131 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "fileops.h"
+#include "repository.h"
+#include "config.h"
+#include "git2/config.h"
+#include "vector.h"
+#include "filter.h"
+
+struct map_data {
+	const char *cvar_name;
+	git_cvar_map *maps;
+	size_t map_count;
+	int default_value;
+};
+
+/*
+ *	core.eol
+ *		Sets the line ending type to use in the working directory for
+ *	files that have the text property set. Alternatives are lf, crlf
+ *	and native, which uses the platform's native line ending. The default
+ *	value is native. See gitattributes(5) for more information on
+ *	end-of-line conversion.
+ */
+static git_cvar_map _cvar_map_eol[] = {
+	{GIT_CVAR_FALSE, NULL, GIT_EOL_UNSET},
+	{GIT_CVAR_STRING, "lf", GIT_EOL_LF},
+	{GIT_CVAR_STRING, "crlf", GIT_EOL_CRLF},
+	{GIT_CVAR_STRING, "native", GIT_EOL_NATIVE}
+};
+
+/*
+ *	core.autocrlf
+ *		Setting this variable to "true" is almost the same as setting
+ *	the text attribute to "auto" on all files except that text files are
+ *	not guaranteed to be normalized: files that contain CRLF in the
+ *	repository will not be touched. Use this setting if you want to have
+ *	CRLF line endings in your working directory even though the repository
+ *	does not have normalized line endings. This variable can be set to input,
+ *	in which case no output conversion is performed.
+ */
+static git_cvar_map _cvar_map_autocrlf[] = {
+	{GIT_CVAR_FALSE, NULL, GIT_AUTO_CRLF_FALSE},
+	{GIT_CVAR_TRUE, NULL, GIT_AUTO_CRLF_TRUE},
+	{GIT_CVAR_STRING, "input", GIT_AUTO_CRLF_INPUT}
+};
+
+static git_cvar_map _cvar_map_safecrlf[] = {
+	{GIT_CVAR_FALSE, NULL, GIT_SAFE_CRLF_FALSE},
+	{GIT_CVAR_TRUE, NULL, GIT_SAFE_CRLF_FAIL},
+	{GIT_CVAR_STRING, "warn", GIT_SAFE_CRLF_WARN}
+};
+
+/*
+ * Generic map for integer values
+ */
+static git_cvar_map _cvar_map_int[] = {
+	{GIT_CVAR_INT32, NULL, 0},
+};
+
+static struct map_data _cvar_maps[] = {
+	{"core.autocrlf", _cvar_map_autocrlf, ARRAY_SIZE(_cvar_map_autocrlf), GIT_AUTO_CRLF_DEFAULT},
+	{"core.eol", _cvar_map_eol, ARRAY_SIZE(_cvar_map_eol), GIT_EOL_DEFAULT},
+	{"core.symlinks", NULL, 0, GIT_SYMLINKS_DEFAULT },
+	{"core.ignorecase", NULL, 0, GIT_IGNORECASE_DEFAULT },
+	{"core.filemode", NULL, 0, GIT_FILEMODE_DEFAULT },
+	{"core.ignorestat", NULL, 0, GIT_IGNORESTAT_DEFAULT },
+	{"core.trustctime", NULL, 0, GIT_TRUSTCTIME_DEFAULT },
+	{"core.abbrev", _cvar_map_int, 1, GIT_ABBREV_DEFAULT },
+	{"core.precomposeunicode", NULL, 0, GIT_PRECOMPOSE_DEFAULT },
+	{"core.safecrlf", _cvar_map_safecrlf, ARRAY_SIZE(_cvar_map_safecrlf), GIT_SAFE_CRLF_DEFAULT},
+	{"core.logallrefupdates", NULL, 0, GIT_LOGALLREFUPDATES_DEFAULT },
+	{"core.protecthfs", NULL, 0, GIT_PROTECTHFS_DEFAULT },
+	{"core.protectntfs", NULL, 0, GIT_PROTECTNTFS_DEFAULT },
+	{"core.fsyncobjectfiles", NULL, 0, GIT_FSYNCOBJECTFILES_DEFAULT },
+};
+
+int git_config__cvar(int *out, git_config *config, git_cvar_cached cvar)
+{
+	int error = 0;
+	struct map_data *data = &_cvar_maps[(int)cvar];
+	git_config_entry *entry;
+
+	if ((error = git_config__lookup_entry(&entry, config, data->cvar_name, false)) < 0)
+		return error;
+
+	if (!entry)
+		*out = data->default_value;
+	else if (data->maps)
+		error = git_config_lookup_map_value(
+			out, data->maps, data->map_count, entry->value);
+	else
+		error = git_config_parse_bool(out, entry->value);
+
+	git_config_entry_free(entry);
+	return error;
+}
+
+int git_repository__cvar(int *out, git_repository *repo, git_cvar_cached cvar)
+{
+	*out = repo->cvar_cache[(int)cvar];
+
+	if (*out == GIT_CVAR_NOT_CACHED) {
+		int error;
+		git_config *config;
+
+		if ((error = git_repository_config__weakptr(&config, repo)) < 0 ||
+			(error = git_config__cvar(out, config, cvar)) < 0)
+			return error;
+
+		repo->cvar_cache[(int)cvar] = *out;
+	}
+
+	return 0;
+}
+
+void git_repository__cvar_cache_clear(git_repository *repo)
+{
+	int i;
+
+	for (i = 0; i < GIT_CVAR_CACHE_MAX; ++i)
+		repo->cvar_cache[i] = GIT_CVAR_NOT_CACHED;
+}
+

vendor/libgit2-sys/libgit2/src/config_file.c

diff --git a/vendor/libgit2-sys/libgit2/src/config_file.c b/vendor/libgit2-sys/libgit2/src/config_file.c
new file mode 100644
index 0000000..6c65208
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/config_file.c
@@ -0,0 +1,1429 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "config_file.h"
+
+#include "config.h"
+#include "filebuf.h"
+#include "sysdir.h"
+#include "buffer.h"
+#include "buf_text.h"
+#include "git2/config.h"
+#include "git2/sys/config.h"
+#include "git2/types.h"
+#include "strmap.h"
+#include "array.h"
+#include "config_parse.h"
+
+#include <ctype.h>
+#include <sys/types.h>
+#include <regex.h>
+
+typedef struct config_entry_list {
+	struct config_entry_list *next;
+	git_config_entry *entry;
+} config_entry_list;
+
+typedef struct git_config_file_iter {
+	git_config_iterator parent;
+	config_entry_list *head;
+} git_config_file_iter;
+
+/* Max depth for [include] directives */
+#define MAX_INCLUDE_DEPTH 10
+
+typedef struct {
+	git_atomic refcount;
+	git_strmap *map;
+	config_entry_list *list;
+} diskfile_entries;
+
+typedef struct {
+	git_config_backend parent;
+	/* mutex to coordinate accessing the values */
+	git_mutex values_mutex;
+	diskfile_entries *entries;
+	const git_repository *repo;
+	git_config_level_t level;
+} diskfile_header;
+
+typedef struct {
+	diskfile_header header;
+
+	git_array_t(git_config_parser) readers;
+
+	bool locked;
+	git_filebuf locked_buf;
+	git_buf locked_content;
+
+	struct config_file file;
+} diskfile_backend;
+
+typedef struct {
+	diskfile_header header;
+
+	diskfile_backend *snapshot_from;
+} diskfile_readonly_backend;
+
+typedef struct {
+	const git_repository *repo;
+	const char *file_path;
+	diskfile_entries *entries;
+	git_config_level_t level;
+	unsigned int depth;
+} diskfile_parse_state;
+
+static int config_read(diskfile_entries *entries, const git_repository *repo, git_config_file *file, git_config_level_t level, int depth);
+static int config_write(diskfile_backend *cfg, const char *orig_key, const char *key, const regex_t *preg, const char *value);
+static char *escape_value(const char *ptr);
+
+int git_config_file__snapshot(git_config_backend **out, diskfile_backend *in);
+static int config_snapshot(git_config_backend **out, git_config_backend *in);
+
+static int config_error_readonly(void)
+{
+	giterr_set(GITERR_CONFIG, "this backend is read-only");
+	return -1;
+}
+
+static void config_entry_list_free(config_entry_list *list)
+{
+	config_entry_list *next;
+
+	while (list != NULL) {
+		next = list->next;
+
+		git__free((char*) list->entry->name);
+		git__free((char *) list->entry->value);
+		git__free(list->entry);
+		git__free(list);
+
+		list = next;
+	};
+}
+
+int git_config_file_normalize_section(char *start, char *end)
+{
+	char *scan;
+
+	if (start == end)
+		return GIT_EINVALIDSPEC;
+
+	/* Validate and downcase range */
+	for (scan = start; *scan; ++scan) {
+		if (end && scan >= end)
+			break;
+		if (isalnum(*scan))
+			*scan = (char)git__tolower(*scan);
+		else if (*scan != '-' || scan == start)
+			return GIT_EINVALIDSPEC;
+	}
+
+	if (scan == start)
+		return GIT_EINVALIDSPEC;
+
+	return 0;
+}
+
+static void config_entry_list_append(config_entry_list **list, config_entry_list *entry)
+{
+	config_entry_list *head = *list;
+
+	if (head) {
+		while (head->next != NULL)
+			head = head->next;
+		head->next = entry;
+	} else {
+		*list = entry;
+	}
+}
+
+/* Add or append the new config option */
+static int diskfile_entries_append(diskfile_entries *entries, git_config_entry *entry)
+{
+	git_strmap_iter pos;
+	config_entry_list *existing, *var;
+	int error = 0;
+
+	var = git__calloc(1, sizeof(config_entry_list));
+	GITERR_CHECK_ALLOC(var);
+	var->entry = entry;
+
+	pos = git_strmap_lookup_index(entries->map, entry->name);
+	if (!git_strmap_valid_index(entries->map, pos)) {
+		git_strmap_insert(entries->map, entry->name, var, &error);
+
+		if (error > 0)
+			error = 0;
+	} else {
+		existing = git_strmap_value_at(entries->map, pos);
+		config_entry_list_append(&existing, var);
+	}
+
+	var = git__calloc(1, sizeof(config_entry_list));
+	GITERR_CHECK_ALLOC(var);
+	var->entry = entry;
+	config_entry_list_append(&entries->list, var);
+
+	return error;
+}
+
+static void diskfile_entries_free(diskfile_entries *entries)
+{
+	config_entry_list *list = NULL, *next;
+
+	if (!entries)
+		return;
+
+	if (git_atomic_dec(&entries->refcount) != 0)
+		return;
+
+	git_strmap_foreach_value(entries->map, list, config_entry_list_free(list));
+	git_strmap_free(entries->map);
+
+	list = entries->list;
+	while (list != NULL) {
+		next = list->next;
+		git__free(list);
+		list = next;
+	}
+
+	git__free(entries);
+}
+
+/**
+ * Take the current values map from the backend and increase its
+ * refcount. This is its own function to make sure we use the mutex to
+ * avoid the map pointer from changing under us.
+ */
+static diskfile_entries *diskfile_entries_take(diskfile_header *h)
+{
+	diskfile_entries *entries;
+
+	if (git_mutex_lock(&h->values_mutex) < 0) {
+	    giterr_set(GITERR_OS, "failed to lock config backend");
+	    return NULL;
+	}
+
+	entries = h->entries;
+	git_atomic_inc(&entries->refcount);
+
+	git_mutex_unlock(&h->values_mutex);
+
+	return entries;
+}
+
+static int diskfile_entries_alloc(diskfile_entries **out)
+{
+	diskfile_entries *entries;
+	int error;
+
+	entries = git__calloc(1, sizeof(diskfile_entries));
+	GITERR_CHECK_ALLOC(entries);
+
+	git_atomic_set(&entries->refcount, 1);
+
+	if ((error = git_strmap_alloc(&entries->map)) < 0)
+		git__free(entries);
+	else
+		*out = entries;
+
+	return error;
+}
+
+static void config_file_clear(struct config_file *file)
+{
+	struct config_file *include;
+	uint32_t i;
+
+	if (file == NULL)
+		return;
+
+	git_array_foreach(file->includes, i, include) {
+		config_file_clear(include);
+	}
+	git_array_clear(file->includes);
+
+	git__free(file->path);
+}
+
+static int config_open(git_config_backend *cfg, git_config_level_t level, const git_repository *repo)
+{
+	int res;
+	diskfile_backend *b = (diskfile_backend *)cfg;
+
+	b->header.level = level;
+	b->header.repo = repo;
+
+	if ((res = diskfile_entries_alloc(&b->header.entries)) < 0)
+		return res;
+
+	if (!git_path_exists(b->file.path))
+		return 0;
+
+	if (res < 0 || (res = config_read(b->header.entries, repo, &b->file, level, 0)) < 0) {
+		diskfile_entries_free(b->header.entries);
+		b->header.entries = NULL;
+	}
+
+	return res;
+}
+
+static int config_is_modified(int *modified, struct config_file *file)
+{
+	git_config_file *include;
+	git_buf buf = GIT_BUF_INIT;
+	git_oid hash;
+	uint32_t i;
+	int error = 0;
+
+	*modified = 0;
+
+	if ((error = git_futils_readbuffer(&buf, file->path)) < 0)
+		goto out;
+
+	if ((error = git_hash_buf(&hash, buf.ptr, buf.size)) < 0)
+		goto out;
+
+	if (!git_oid_equal(&hash, &file->checksum)) {
+		*modified = 1;
+		goto out;
+	}
+
+	git_array_foreach(file->includes, i, include) {
+		if ((error = config_is_modified(modified, include)) < 0 || *modified)
+			goto out;
+	}
+
+out:
+	git_buf_free(&buf);
+
+	return error;
+}
+
+static int config_refresh(git_config_backend *cfg)
+{
+	diskfile_backend *b = (diskfile_backend *)cfg;
+	diskfile_entries *entries = NULL, *tmp;
+	git_config_file *include;
+	int error, modified;
+	uint32_t i;
+
+	if (b->header.parent.readonly)
+		return config_error_readonly();
+
+	error = config_is_modified(&modified, &b->file);
+	if (error < 0 && error != GIT_ENOTFOUND)
+		goto out;
+
+	if (!modified)
+		return 0;
+
+	if ((error = diskfile_entries_alloc(&entries)) < 0)
+		goto out;
+
+	/* Reparse the current configuration */
+	git_array_foreach(b->file.includes, i, include) {
+		config_file_clear(include);
+	}
+	git_array_clear(b->file.includes);
+
+	if ((error = config_read(entries, b->header.repo, &b->file, b->header.level, 0)) < 0)
+		goto out;
+
+	if ((error = git_mutex_lock(&b->header.values_mutex)) < 0) {
+		giterr_set(GITERR_OS, "failed to lock config backend");
+		goto out;
+	}
+
+	tmp = b->header.entries;
+	b->header.entries = entries;
+	entries = tmp;
+
+	git_mutex_unlock(&b->header.values_mutex);
+
+out:
+	diskfile_entries_free(entries);
+
+	return (error == GIT_ENOTFOUND) ? 0 : error;
+}
+
+static void backend_free(git_config_backend *_backend)
+{
+	diskfile_backend *backend = (diskfile_backend *)_backend;
+
+	if (backend == NULL)
+		return;
+
+	config_file_clear(&backend->file);
+	diskfile_entries_free(backend->header.entries);
+	git_mutex_free(&backend->header.values_mutex);
+	git__free(backend);
+}
+
+static void config_iterator_free(
+	git_config_iterator* iter)
+{
+	iter->backend->free(iter->backend);
+	git__free(iter);
+}
+
+static int config_iterator_next(
+	git_config_entry **entry,
+	git_config_iterator *iter)
+{
+	git_config_file_iter *it = (git_config_file_iter *) iter;
+
+	if (!it->head)
+		return GIT_ITEROVER;
+
+	*entry = it->head->entry;
+	it->head = it->head->next;
+
+	return 0;
+}
+
+static int config_iterator_new(
+	git_config_iterator **iter,
+	struct git_config_backend* backend)
+{
+	diskfile_header *h;
+	git_config_file_iter *it;
+	git_config_backend *snapshot;
+	diskfile_header *bh = (diskfile_header *) backend;
+	int error;
+
+	if ((error = config_snapshot(&snapshot, backend)) < 0)
+		return error;
+
+	if ((error = snapshot->open(snapshot, bh->level, bh->repo)) < 0)
+		return error;
+
+	it = git__calloc(1, sizeof(git_config_file_iter));
+	GITERR_CHECK_ALLOC(it);
+
+	h = (diskfile_header *)snapshot;
+
+	it->parent.backend = snapshot;
+	it->head = h->entries->list;
+	it->parent.next = config_iterator_next;
+	it->parent.free = config_iterator_free;
+
+	*iter = (git_config_iterator *) it;
+
+	return 0;
+}
+
+static int config_set(git_config_backend *cfg, const char *name, const char *value)
+{
+	diskfile_backend *b = (diskfile_backend *)cfg;
+	diskfile_entries *entries;
+	git_strmap *entry_map;
+	char *key, *esc_value = NULL;
+	khiter_t pos;
+	int rval, ret;
+
+	if ((rval = git_config__normalize_name(name, &key)) < 0)
+		return rval;
+
+	if ((entries = diskfile_entries_take(&b->header)) == NULL)
+		return -1;
+	entry_map = entries->map;
+
+	/*
+	 * Try to find it in the existing values and update it if it
+	 * only has one value.
+	 */
+	pos = git_strmap_lookup_index(entry_map, key);
+	if (git_strmap_valid_index(entry_map, pos)) {
+		config_entry_list *existing = git_strmap_value_at(entry_map, pos);
+
+		if (existing->next != NULL) {
+			giterr_set(GITERR_CONFIG, "multivar incompatible with simple set");
+			ret = -1;
+			goto out;
+		}
+
+		if (existing->entry->include_depth) {
+			giterr_set(GITERR_CONFIG, "modifying included variable is not supported");
+			ret = -1;
+			goto out;
+		}
+
+		/* don't update if old and new values already match */
+		if ((!existing->entry->value && !value) ||
+			(existing->entry->value && value &&
+			 !strcmp(existing->entry->value, value))) {
+			ret = 0;
+			goto out;
+		}
+	}
+
+	/* No early returns due to sanity checks, let's write it out and refresh */
+
+	if (value) {
+		esc_value = escape_value(value);
+		GITERR_CHECK_ALLOC(esc_value);
+	}
+
+	if ((ret = config_write(b, name, key, NULL, esc_value)) < 0)
+		goto out;
+
+	ret = config_refresh(cfg);
+
+out:
+	diskfile_entries_free(entries);
+	git__free(esc_value);
+	git__free(key);
+	return ret;
+}
+
+/* release the map containing the entry as an equivalent to freeing it */
+static void free_diskfile_entry(git_config_entry *entry)
+{
+	diskfile_entries *map = (diskfile_entries *) entry->payload;
+	diskfile_entries_free(map);
+}
+
+/*
+ * Internal function that actually gets the value in string form
+ */
+static int config_get(git_config_backend *cfg, const char *key, git_config_entry **out)
+{
+	diskfile_header *h = (diskfile_header *)cfg;
+	diskfile_entries *entries;
+	git_strmap *entry_map;
+	khiter_t pos;
+	config_entry_list *var;
+	int error = 0;
+
+	if (!h->parent.readonly && ((error = config_refresh(cfg)) < 0))
+		return error;
+
+	if ((entries = diskfile_entries_take(h)) == NULL)
+		return -1;
+	entry_map = entries->map;
+
+	pos = git_strmap_lookup_index(entry_map, key);
+
+	/* no error message; the config system will write one */
+	if (!git_strmap_valid_index(entry_map, pos)) {
+		diskfile_entries_free(entries);
+		return GIT_ENOTFOUND;
+	}
+
+	var = git_strmap_value_at(entry_map, pos);
+	while (var->next)
+		var = var->next;
+
+	*out = var->entry;
+	(*out)->free = free_diskfile_entry;
+	(*out)->payload = entries;
+
+	return error;
+}
+
+static int config_set_multivar(
+	git_config_backend *cfg, const char *name, const char *regexp, const char *value)
+{
+	diskfile_backend *b = (diskfile_backend *)cfg;
+	char *key;
+	regex_t preg;
+	int result;
+
+	assert(regexp);
+
+	if ((result = git_config__normalize_name(name, &key)) < 0)
+		return result;
+
+	result = p_regcomp(&preg, regexp, REG_EXTENDED);
+	if (result != 0) {
+		giterr_set_regex(&preg, result);
+		result = -1;
+		goto out;
+	}
+
+	/* If we do have it, set call config_write() and reload */
+	if ((result = config_write(b, name, key, &preg, value)) < 0)
+		goto out;
+
+	result = config_refresh(cfg);
+
+out:
+	git__free(key);
+	regfree(&preg);
+
+	return result;
+}
+
+static int config_delete(git_config_backend *cfg, const char *name)
+{
+	config_entry_list *var;
+	diskfile_backend *b = (diskfile_backend *)cfg;
+	diskfile_entries *map;
+	git_strmap *entry_map;
+	char *key;
+	int result;
+	khiter_t pos;
+
+	if ((result = git_config__normalize_name(name, &key)) < 0)
+		return result;
+
+	if ((map = diskfile_entries_take(&b->header)) == NULL)
+		return -1;
+	entry_map = b->header.entries->map;
+
+	pos = git_strmap_lookup_index(entry_map, key);
+	git__free(key);
+
+	if (!git_strmap_valid_index(entry_map, pos)) {
+		diskfile_entries_free(map);
+		giterr_set(GITERR_CONFIG, "could not find key '%s' to delete", name);
+		return GIT_ENOTFOUND;
+	}
+
+	var = git_strmap_value_at(entry_map, pos);
+	diskfile_entries_free(map);
+
+	if (var->entry->include_depth) {
+		giterr_set(GITERR_CONFIG, "cannot delete included variable");
+		return -1;
+	}
+
+	if (var->next != NULL) {
+		giterr_set(GITERR_CONFIG, "cannot delete multivar with a single delete");
+		return -1;
+	}
+
+	if ((result = config_write(b, name, var->entry->name, NULL, NULL)) < 0)
+		return result;
+
+	return config_refresh(cfg);
+}
+
+static int config_delete_multivar(git_config_backend *cfg, const char *name, const char *regexp)
+{
+	diskfile_backend *b = (diskfile_backend *)cfg;
+	diskfile_entries *map;
+	git_strmap *entry_map;
+	char *key;
+	regex_t preg;
+	int result;
+	khiter_t pos;
+
+	if ((result = git_config__normalize_name(name, &key)) < 0)
+		return result;
+
+	if ((map = diskfile_entries_take(&b->header)) == NULL)
+		return -1;
+	entry_map = b->header.entries->map;
+
+	pos = git_strmap_lookup_index(entry_map, key);
+
+	if (!git_strmap_valid_index(entry_map, pos)) {
+		diskfile_entries_free(map);
+		git__free(key);
+		giterr_set(GITERR_CONFIG, "could not find key '%s' to delete", name);
+		return GIT_ENOTFOUND;
+	}
+
+	diskfile_entries_free(map);
+
+	result = p_regcomp(&preg, regexp, REG_EXTENDED);
+	if (result != 0) {
+		giterr_set_regex(&preg, result);
+		result = -1;
+		goto out;
+	}
+
+	if ((result = config_write(b, name, key, &preg, NULL)) < 0)
+		goto out;
+
+	result = config_refresh(cfg);
+
+out:
+	git__free(key);
+	regfree(&preg);
+	return result;
+}
+
+static int config_snapshot(git_config_backend **out, git_config_backend *in)
+{
+	diskfile_backend *b = (diskfile_backend *) in;
+
+	return git_config_file__snapshot(out, b);
+}
+
+static int config_lock(git_config_backend *_cfg)
+{
+	diskfile_backend *cfg = (diskfile_backend *) _cfg;
+	int error;
+
+	if ((error = git_filebuf_open(&cfg->locked_buf, cfg->file.path, 0, GIT_CONFIG_FILE_MODE)) < 0)
+		return error;
+
+	error = git_futils_readbuffer(&cfg->locked_content, cfg->file.path);
+	if (error < 0 && error != GIT_ENOTFOUND) {
+		git_filebuf_cleanup(&cfg->locked_buf);
+		return error;
+	}
+
+	cfg->locked = true;
+	return 0;
+
+}
+
+static int config_unlock(git_config_backend *_cfg, int success)
+{
+	diskfile_backend *cfg = (diskfile_backend *) _cfg;
+	int error = 0;
+
+	if (success) {
+		git_filebuf_write(&cfg->locked_buf, cfg->locked_content.ptr, cfg->locked_content.size);
+		error = git_filebuf_commit(&cfg->locked_buf);
+	}
+
+	git_filebuf_cleanup(&cfg->locked_buf);
+	git_buf_free(&cfg->locked_content);
+	cfg->locked = false;
+
+	return error;
+}
+
+int git_config_file__ondisk(git_config_backend **out, const char *path)
+{
+	diskfile_backend *backend;
+
+	backend = git__calloc(1, sizeof(diskfile_backend));
+	GITERR_CHECK_ALLOC(backend);
+
+	backend->header.parent.version = GIT_CONFIG_BACKEND_VERSION;
+	git_mutex_init(&backend->header.values_mutex);
+
+	backend->file.path = git__strdup(path);
+	GITERR_CHECK_ALLOC(backend->file.path);
+	git_array_init(backend->file.includes);
+
+	backend->header.parent.open = config_open;
+	backend->header.parent.get = config_get;
+	backend->header.parent.set = config_set;
+	backend->header.parent.set_multivar = config_set_multivar;
+	backend->header.parent.del = config_delete;
+	backend->header.parent.del_multivar = config_delete_multivar;
+	backend->header.parent.iterator = config_iterator_new;
+	backend->header.parent.snapshot = config_snapshot;
+	backend->header.parent.lock = config_lock;
+	backend->header.parent.unlock = config_unlock;
+	backend->header.parent.free = backend_free;
+
+	*out = (git_config_backend *)backend;
+
+	return 0;
+}
+
+static int config_set_readonly(git_config_backend *cfg, const char *name, const char *value)
+{
+	GIT_UNUSED(cfg);
+	GIT_UNUSED(name);
+	GIT_UNUSED(value);
+
+	return config_error_readonly();
+}
+
+static int config_set_multivar_readonly(
+	git_config_backend *cfg, const char *name, const char *regexp, const char *value)
+{
+	GIT_UNUSED(cfg);
+	GIT_UNUSED(name);
+	GIT_UNUSED(regexp);
+	GIT_UNUSED(value);
+
+	return config_error_readonly();
+}
+
+static int config_delete_multivar_readonly(git_config_backend *cfg, const char *name, const char *regexp)
+{
+	GIT_UNUSED(cfg);
+	GIT_UNUSED(name);
+	GIT_UNUSED(regexp);
+
+	return config_error_readonly();
+}
+
+static int config_delete_readonly(git_config_backend *cfg, const char *name)
+{
+	GIT_UNUSED(cfg);
+	GIT_UNUSED(name);
+
+	return config_error_readonly();
+}
+
+static int config_lock_readonly(git_config_backend *_cfg)
+{
+	GIT_UNUSED(_cfg);
+
+	return config_error_readonly();
+}
+
+static int config_unlock_readonly(git_config_backend *_cfg, int success)
+{
+	GIT_UNUSED(_cfg);
+	GIT_UNUSED(success);
+
+	return config_error_readonly();
+}
+
+static void backend_readonly_free(git_config_backend *_backend)
+{
+	diskfile_backend *backend = (diskfile_backend *)_backend;
+
+	if (backend == NULL)
+		return;
+
+	diskfile_entries_free(backend->header.entries);
+	git_mutex_free(&backend->header.values_mutex);
+	git__free(backend);
+}
+
+static int config_readonly_open(git_config_backend *cfg, git_config_level_t level, const git_repository *repo)
+{
+	diskfile_readonly_backend *b = (diskfile_readonly_backend *) cfg;
+	diskfile_backend *src = b->snapshot_from;
+	diskfile_header *src_header = &src->header;
+	diskfile_entries *entries;
+	int error;
+
+	if (!src_header->parent.readonly && (error = config_refresh(&src_header->parent)) < 0)
+		return error;
+
+	/* We're just copying data, don't care about the level or repo*/
+	GIT_UNUSED(level);
+	GIT_UNUSED(repo);
+
+	if ((entries = diskfile_entries_take(src_header)) == NULL)
+		return -1;
+	b->header.entries = entries;
+
+	return 0;
+}
+
+int git_config_file__snapshot(git_config_backend **out, diskfile_backend *in)
+{
+	diskfile_readonly_backend *backend;
+
+	backend = git__calloc(1, sizeof(diskfile_readonly_backend));
+	GITERR_CHECK_ALLOC(backend);
+
+	backend->header.parent.version = GIT_CONFIG_BACKEND_VERSION;
+	git_mutex_init(&backend->header.values_mutex);
+
+	backend->snapshot_from = in;
+
+	backend->header.parent.readonly = 1;
+	backend->header.parent.version = GIT_CONFIG_BACKEND_VERSION;
+	backend->header.parent.open = config_readonly_open;
+	backend->header.parent.get = config_get;
+	backend->header.parent.set = config_set_readonly;
+	backend->header.parent.set_multivar = config_set_multivar_readonly;
+	backend->header.parent.del = config_delete_readonly;
+	backend->header.parent.del_multivar = config_delete_multivar_readonly;
+	backend->header.parent.iterator = config_iterator_new;
+	backend->header.parent.lock = config_lock_readonly;
+	backend->header.parent.unlock = config_unlock_readonly;
+	backend->header.parent.free = backend_readonly_free;
+
+	*out = (git_config_backend *)backend;
+
+	return 0;
+}
+
+static int included_path(git_buf *out, const char *dir, const char *path)
+{
+	/* From the user's home */
+	if (path[0] == '~' && path[1] == '/')
+		return git_sysdir_expand_global_file(out, &path[1]);
+
+	return git_path_join_unrooted(out, path, dir, NULL);
+}
+
+/* Escape the values to write them to the file */
+static char *escape_value(const char *ptr)
+{
+	git_buf buf;
+	size_t len;
+	const char *esc;
+
+	assert(ptr);
+
+	len = strlen(ptr);
+	if (!len)
+		return git__calloc(1, sizeof(char));
+
+	if (git_buf_init(&buf, len) < 0)
+		return NULL;
+
+	while (*ptr != '\0') {
+		if ((esc = strchr(git_config_escaped, *ptr)) != NULL) {
+			git_buf_putc(&buf, '\\');
+			git_buf_putc(&buf, git_config_escapes[esc - git_config_escaped]);
+		} else {
+			git_buf_putc(&buf, *ptr);
+		}
+		ptr++;
+	}
+
+	if (git_buf_oom(&buf)) {
+		git_buf_free(&buf);
+		return NULL;
+	}
+
+	return git_buf_detach(&buf);
+}
+
+static int parse_include(git_config_parser *reader,
+	diskfile_parse_state *parse_data, const char *file)
+{
+	struct config_file *include;
+	git_buf path = GIT_BUF_INIT;
+	char *dir;
+	int result;
+
+	if ((result = git_path_dirname_r(&path, reader->file->path)) < 0)
+		return result;
+
+	dir = git_buf_detach(&path);
+	result = included_path(&path, dir, file);
+	git__free(dir);
+
+	if (result < 0)
+		return result;
+
+	include = git_array_alloc(reader->file->includes);
+	memset(include, 0, sizeof(*include));
+	git_array_init(include->includes);
+	include->path = git_buf_detach(&path);
+
+	result = config_read(parse_data->entries, parse_data->repo,
+		include, parse_data->level, parse_data->depth+1);
+
+	if (result == GIT_ENOTFOUND) {
+		giterr_clear();
+		result = 0;
+	}
+
+	return result;
+}
+
+static int do_match_gitdir(
+	int *matches,
+	const git_repository *repo,
+	const char *cfg_file,
+	const char *value,
+	bool case_insensitive)
+{
+	git_buf path = GIT_BUF_INIT;
+	int error, fnmatch_flags;
+
+	if (value[0] == '.' && git_path_is_dirsep(value[1])) {
+		git_path_dirname_r(&path, cfg_file);
+		git_buf_joinpath(&path, path.ptr, value + 2);
+	} else if (value[0] == '~' && git_path_is_dirsep(value[1]))
+		git_sysdir_expand_global_file(&path, value + 1);
+	else if (!git_path_is_absolute(value))
+		git_buf_joinpath(&path, "**", value);
+	else
+		git_buf_sets(&path, value);
+
+	if (git_buf_oom(&path)) {
+		error = -1;
+		goto out;
+	}
+
+	if (git_path_is_dirsep(value[strlen(value) - 1]))
+		git_buf_puts(&path, "**");
+
+	fnmatch_flags = FNM_PATHNAME|FNM_LEADING_DIR;
+	if (case_insensitive)
+		fnmatch_flags |= FNM_IGNORECASE;
+
+	if ((error = p_fnmatch(path.ptr, git_repository_path(repo), fnmatch_flags)) < 0)
+		goto out;
+
+	*matches = (error == 0);
+
+out:
+	git_buf_free(&path);
+	return error;
+}
+
+static int conditional_match_gitdir(
+	int *matches,
+	const git_repository *repo,
+	const char *cfg_file,
+	const char *value)
+{
+	return do_match_gitdir(matches, repo, cfg_file, value, false);
+}
+
+static int conditional_match_gitdir_i(
+	int *matches,
+	const git_repository *repo,
+	const char *cfg_file,
+	const char *value)
+{
+	return do_match_gitdir(matches, repo, cfg_file, value, true);
+}
+
+static const struct {
+	const char *prefix;
+	int (*matches)(int *matches, const git_repository *repo, const char *cfg, const char *value);
+} conditions[] = {
+	{ "gitdir:", conditional_match_gitdir },
+	{ "gitdir/i:", conditional_match_gitdir_i }
+};
+
+static int parse_conditional_include(git_config_parser *reader,
+	diskfile_parse_state *parse_data, const char *section, const char *file)
+{
+	char *condition;
+	size_t i;
+	int error = 0, matches;
+
+	if (!parse_data->repo)
+		return 0;
+
+	condition = git__substrdup(section + strlen("includeIf."),
+				   strlen(section) - strlen("includeIf.") - strlen(".path"));
+
+	for (i = 0; i < ARRAY_SIZE(conditions); i++) {
+		if (git__prefixcmp(condition, conditions[i].prefix))
+			continue;
+
+		if ((error = conditions[i].matches(&matches,
+						   parse_data->repo,
+						   parse_data->file_path,
+						   condition + strlen(conditions[i].prefix))) < 0)
+			break;
+
+		if (matches)
+			error = parse_include(reader, parse_data, file);
+
+		break;
+	}
+
+	git__free(condition);
+	return error;
+}
+
+static int read_on_variable(
+	git_config_parser *reader,
+	const char *current_section,
+	char *var_name,
+	char *var_value,
+	const char *line,
+	size_t line_len,
+	void *data)
+{
+	diskfile_parse_state *parse_data = (diskfile_parse_state *)data;
+	git_buf buf = GIT_BUF_INIT;
+	git_config_entry *entry;
+	int result = 0;
+
+	GIT_UNUSED(line);
+	GIT_UNUSED(line_len);
+
+	git__strtolower(var_name);
+	git_buf_printf(&buf, "%s.%s", current_section, var_name);
+	git__free(var_name);
+
+	if (git_buf_oom(&buf)) {
+		git__free(var_value);
+		return -1;
+	}
+
+	entry = git__calloc(1, sizeof(git_config_entry));
+	GITERR_CHECK_ALLOC(entry);
+	entry->name = git_buf_detach(&buf);
+	entry->value = var_value;
+	entry->level = parse_data->level;
+	entry->include_depth = parse_data->depth;
+
+	if ((result = diskfile_entries_append(parse_data->entries, entry)) < 0)
+		return result;
+
+	result = 0;
+
+	/* Add or append the new config option */
+	if (!git__strcmp(entry->name, "include.path"))
+		result = parse_include(reader, parse_data, entry->value);
+	else if (!git__prefixcmp(entry->name, "includeif.") &&
+	         !git__suffixcmp(entry->name, ".path"))
+		result = parse_conditional_include(reader, parse_data,
+						   entry->name, entry->value);
+
+
+	return result;
+}
+
+static int config_read(
+	diskfile_entries *entries,
+	const git_repository *repo,
+	git_config_file *file,
+	git_config_level_t level,
+	int depth)
+{
+	diskfile_parse_state parse_data;
+	git_config_parser reader;
+	git_buf contents = GIT_BUF_INIT;
+	int error;
+
+	if (depth >= MAX_INCLUDE_DEPTH) {
+		giterr_set(GITERR_CONFIG, "maximum config include depth reached");
+		return -1;
+	}
+
+	if ((error = git_futils_readbuffer(&contents, file->path)) < 0)
+		goto out;
+
+	git_parse_ctx_init(&reader.ctx, contents.ptr, contents.size);
+
+	if ((error = git_hash_buf(&file->checksum, contents.ptr, contents.size)) < 0)
+		goto out;
+
+	/* Initialize the reading position */
+	reader.file = file;
+	git_parse_ctx_init(&reader.ctx, contents.ptr, contents.size);
+
+	/* If the file is empty, there's nothing for us to do */
+	if (!reader.ctx.content || *reader.ctx.content == '\0')
+		goto out;
+
+	parse_data.repo = repo;
+	parse_data.file_path = file->path;
+	parse_data.entries = entries;
+	parse_data.level = level;
+	parse_data.depth = depth;
+
+	error = git_config_parse(&reader, NULL, read_on_variable, NULL, NULL, &parse_data);
+
+out:
+	git_buf_free(&contents);
+	return error;
+}
+
+static int write_section(git_buf *fbuf, const char *key)
+{
+	int result;
+	const char *dot;
+	git_buf buf = GIT_BUF_INIT;
+
+	/* All of this just for [section "subsection"] */
+	dot = strchr(key, '.');
+	git_buf_putc(&buf, '[');
+	if (dot == NULL) {
+		git_buf_puts(&buf, key);
+	} else {
+		char *escaped;
+		git_buf_put(&buf, key, dot - key);
+		escaped = escape_value(dot + 1);
+		GITERR_CHECK_ALLOC(escaped);
+		git_buf_printf(&buf, " \"%s\"", escaped);
+		git__free(escaped);
+	}
+	git_buf_puts(&buf, "]\n");
+
+	if (git_buf_oom(&buf))
+		return -1;
+
+	result = git_buf_put(fbuf, git_buf_cstr(&buf), buf.size);
+	git_buf_free(&buf);
+
+	return result;
+}
+
+static const char *quotes_for_value(const char *value)
+{
+	const char *ptr;
+
+	if (value[0] == ' ' || value[0] == '\0')
+		return "\"";
+
+	for (ptr = value; *ptr; ++ptr) {
+		if (*ptr == ';' || *ptr == '#')
+			return "\"";
+	}
+
+	if (ptr[-1] == ' ')
+		return "\"";
+
+	return "";
+}
+
+struct write_data {
+	git_buf *buf;
+	git_buf buffered_comment;
+	unsigned int in_section : 1,
+		preg_replaced : 1;
+	const char *orig_section;
+	const char *section;
+	const char *orig_name;
+	const char *name;
+	const regex_t *preg;
+	const char *value;
+};
+
+static int write_line_to(git_buf *buf, const char *line, size_t line_len)
+{
+	int result = git_buf_put(buf, line, line_len);
+
+	if (!result && line_len && line[line_len-1] != '\n')
+		result = git_buf_printf(buf, "\n");
+
+	return result;
+}
+
+static int write_line(struct write_data *write_data, const char *line, size_t line_len)
+{
+	return write_line_to(write_data->buf, line, line_len);
+}
+
+static int write_value(struct write_data *write_data)
+{
+	const char *q;
+	int result;
+
+	q = quotes_for_value(write_data->value);
+	result = git_buf_printf(write_data->buf,
+		"\t%s = %s%s%s\n", write_data->orig_name, q, write_data->value, q);
+
+	/* If we are updating a single name/value, we're done.  Setting `value`
+	 * to `NULL` will prevent us from trying to write it again later (in
+	 * `write_on_section`) if we see the same section repeated.
+	 */
+	if (!write_data->preg)
+		write_data->value = NULL;
+
+	return result;
+}
+
+static int write_on_section(
+	git_config_parser *reader,
+	const char *current_section,
+	const char *line,
+	size_t line_len,
+	void *data)
+{
+	struct write_data *write_data = (struct write_data *)data;
+	int result = 0;
+
+	GIT_UNUSED(reader);
+
+	/* If we were previously in the correct section (but aren't anymore)
+	 * and haven't written our value (for a simple name/value set, not
+	 * a multivar), then append it to the end of the section before writing
+	 * the new one.
+	 */
+	if (write_data->in_section && !write_data->preg && write_data->value)
+		result = write_value(write_data);
+
+	write_data->in_section = strcmp(current_section, write_data->section) == 0;
+
+	/*
+	 * If there were comments just before this section, dump them as well.
+	 */
+	if (!result) {
+		result = git_buf_put(write_data->buf, write_data->buffered_comment.ptr, write_data->buffered_comment.size);
+		git_buf_clear(&write_data->buffered_comment);
+	}
+
+	if (!result)
+		result = write_line(write_data, line, line_len);
+
+	return result;
+}
+
+static int write_on_variable(
+	git_config_parser *reader,
+	const char *current_section,
+	char *var_name,
+	char *var_value,
+	const char *line,
+	size_t line_len,
+	void *data)
+{
+	struct write_data *write_data = (struct write_data *)data;
+	bool has_matched = false;
+	int error;
+
+	GIT_UNUSED(reader);
+	GIT_UNUSED(current_section);
+
+	/*
+	 * If there were comments just before this variable, let's dump them as well.
+	 */
+	if ((error = git_buf_put(write_data->buf, write_data->buffered_comment.ptr, write_data->buffered_comment.size)) < 0)
+		return error;
+
+	git_buf_clear(&write_data->buffered_comment);
+
+	/* See if we are to update this name/value pair; first examine name */
+	if (write_data->in_section &&
+		strcasecmp(write_data->name, var_name) == 0)
+		has_matched = true;
+
+	/* If we have a regex to match the value, see if it matches */
+	if (has_matched && write_data->preg != NULL)
+		has_matched = (regexec(write_data->preg, var_value, 0, NULL, 0) == 0);
+
+	git__free(var_name);
+	git__free(var_value);
+
+	/* If this isn't the name/value we're looking for, simply dump the
+	 * existing data back out and continue on.
+	 */
+	if (!has_matched)
+		return write_line(write_data, line, line_len);
+
+	write_data->preg_replaced = 1;
+
+	/* If value is NULL, we are deleting this value; write nothing. */
+	if (!write_data->value)
+		return 0;
+
+	return write_value(write_data);
+}
+
+static int write_on_comment(git_config_parser *reader, const char *line, size_t line_len, void *data)
+{
+	struct write_data *write_data;
+
+	GIT_UNUSED(reader);
+
+	write_data = (struct write_data *)data;
+	return write_line_to(&write_data->buffered_comment, line, line_len);
+}
+
+static int write_on_eof(
+	git_config_parser *reader, const char *current_section, void *data)
+{
+	struct write_data *write_data = (struct write_data *)data;
+	int result = 0;
+
+	GIT_UNUSED(reader);
+
+	/*
+	 * If we've buffered comments when reaching EOF, make sure to dump them.
+	 */
+	if ((result = git_buf_put(write_data->buf, write_data->buffered_comment.ptr, write_data->buffered_comment.size)) < 0)
+		return result;
+
+	/* If we are at the EOF and have not written our value (again, for a
+	 * simple name/value set, not a multivar) then we have never seen the
+	 * section in question and should create a new section and write the
+	 * value.
+	 */
+	if ((!write_data->preg || !write_data->preg_replaced) && write_data->value) {
+		/* write the section header unless we're already in it */
+		if (!current_section || strcmp(current_section, write_data->section))
+			result = write_section(write_data->buf, write_data->orig_section);
+
+		if (!result)
+			result = write_value(write_data);
+	}
+
+	return result;
+}
+
+/*
+ * This is pretty much the parsing, except we write out anything we don't have
+ */
+static int config_write(diskfile_backend *cfg, const char *orig_key, const char *key, const regex_t *preg, const char* value)
+{
+	int result;
+	char *orig_section, *section, *orig_name, *name, *ldot;
+	git_filebuf file = GIT_FILEBUF_INIT;
+	git_buf buf = GIT_BUF_INIT, contents = GIT_BUF_INIT;
+	git_config_parser reader;
+	struct write_data write_data;
+
+	memset(&reader, 0, sizeof(reader));
+	reader.file = &cfg->file;
+
+	if (cfg->locked) {
+		result = git_buf_puts(&contents, git_buf_cstr(&cfg->locked_content));
+	} else {
+		/* Lock the file */
+		if ((result = git_filebuf_open(
+			     &file, cfg->file.path, GIT_FILEBUF_HASH_CONTENTS, GIT_CONFIG_FILE_MODE)) < 0) {
+			git_buf_free(&contents);
+			return result;
+		}
+
+		/* We need to read in our own config file */
+		result = git_futils_readbuffer(&contents, cfg->file.path);
+	}
+
+	/* Initialise the reading position */
+	if (result == 0 || result == GIT_ENOTFOUND) {
+		git_parse_ctx_init(&reader.ctx, contents.ptr, contents.size);
+	} else {
+		git_filebuf_cleanup(&file);
+		return -1; /* OS error when reading the file */
+	}
+
+	ldot = strrchr(key, '.');
+	name = ldot + 1;
+	section = git__strndup(key, ldot - key);
+	GITERR_CHECK_ALLOC(section);
+
+	ldot = strrchr(orig_key, '.');
+	orig_name = ldot + 1;
+	orig_section = git__strndup(orig_key, ldot - orig_key);
+	GITERR_CHECK_ALLOC(orig_section);
+
+	write_data.buf = &buf;
+	git_buf_init(&write_data.buffered_comment, 0);
+	write_data.orig_section = orig_section;
+	write_data.section = section;
+	write_data.in_section = 0;
+	write_data.preg_replaced = 0;
+	write_data.orig_name = orig_name;
+	write_data.name = name;
+	write_data.preg = preg;
+	write_data.value = value;
+
+	result = git_config_parse(&reader,
+		write_on_section,
+		write_on_variable,
+		write_on_comment,
+		write_on_eof,
+		&write_data);
+	git__free(section);
+	git__free(orig_section);
+	git_buf_free(&write_data.buffered_comment);
+
+	if (result < 0) {
+		git_filebuf_cleanup(&file);
+		goto done;
+	}
+
+	if (cfg->locked) {
+		size_t len = buf.asize;
+		/* Update our copy with the modified contents */
+		git_buf_free(&cfg->locked_content);
+		git_buf_attach(&cfg->locked_content, git_buf_detach(&buf), len);
+	} else {
+		git_filebuf_write(&file, git_buf_cstr(&buf), git_buf_len(&buf));
+		result = git_filebuf_commit(&file);
+	}
+
+done:
+	git_buf_free(&buf);
+	git_buf_free(&contents);
+	git_parse_ctx_clear(&reader.ctx);
+	return result;
+}

vendor/libgit2-sys/libgit2/src/config_file.h

diff --git a/vendor/libgit2-sys/libgit2/src/config_file.h b/vendor/libgit2-sys/libgit2/src/config_file.h
new file mode 100644
index 0000000..72818e5
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/config_file.h
@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_config_file_h__
+#define INCLUDE_config_file_h__
+
+#include "common.h"
+
+#include "git2/sys/config.h"
+#include "git2/config.h"
+
+GIT_INLINE(int) git_config_file_open(git_config_backend *cfg, unsigned int level, const git_repository *repo)
+{
+	return cfg->open(cfg, level, repo);
+}
+
+GIT_INLINE(void) git_config_file_free(git_config_backend *cfg)
+{
+	if (cfg)
+		cfg->free(cfg);
+}
+
+GIT_INLINE(int) git_config_file_get_string(
+	git_config_entry **out, git_config_backend *cfg, const char *name)
+{
+	return cfg->get(cfg, name, out);
+}
+
+GIT_INLINE(int) git_config_file_set_string(
+	git_config_backend *cfg, const char *name, const char *value)
+{
+	return cfg->set(cfg, name, value);
+}
+
+GIT_INLINE(int) git_config_file_delete(
+	git_config_backend *cfg, const char *name)
+{
+	return cfg->del(cfg, name);
+}
+
+GIT_INLINE(int) git_config_file_foreach(
+	git_config_backend *cfg,
+	int (*fn)(const git_config_entry *entry, void *data),
+	void *data)
+{
+	return git_config_backend_foreach_match(cfg, NULL, fn, data);
+}
+
+GIT_INLINE(int) git_config_file_foreach_match(
+	git_config_backend *cfg,
+	const char *regexp,
+	int (*fn)(const git_config_entry *entry, void *data),
+	void *data)
+{
+	return git_config_backend_foreach_match(cfg, regexp, fn, data);
+}
+
+GIT_INLINE(int) git_config_file_lock(git_config_backend *cfg)
+{
+	return cfg->lock(cfg);
+}
+
+GIT_INLINE(int) git_config_file_unlock(git_config_backend *cfg, int success)
+{
+	return cfg->unlock(cfg, success);
+}
+
+extern int git_config_file_normalize_section(char *start, char *end);
+
+#endif

vendor/libgit2-sys/libgit2/src/config_parse.c

diff --git a/vendor/libgit2-sys/libgit2/src/config_parse.c b/vendor/libgit2-sys/libgit2/src/config_parse.c
new file mode 100644
index 0000000..149550d
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/config_parse.c
@@ -0,0 +1,525 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "config_parse.h"
+
+#include "buf_text.h"
+
+#include <ctype.h>
+
+static void set_parse_error(git_config_parser *reader, int col, const char *error_str)
+{
+	giterr_set(GITERR_CONFIG, "failed to parse config file: %s (in %s:%"PRIuZ", column %d)",
+		error_str, reader->file->path, reader->ctx.line_num, col);
+}
+
+
+GIT_INLINE(int) config_keychar(int c)
+{
+	return isalnum(c) || c == '-';
+}
+
+static int strip_comments(char *line, int in_quotes)
+{
+	int quote_count = in_quotes, backslash_count = 0;
+	char *ptr;
+
+	for (ptr = line; *ptr; ++ptr) {
+		if (ptr[0] == '"' && ptr > line && ptr[-1] != '\\')
+			quote_count++;
+
+		if ((ptr[0] == ';' || ptr[0] == '#') &&
+			(quote_count % 2) == 0 &&
+			(backslash_count % 2) == 0) {
+			ptr[0] = '\0';
+			break;
+		}
+
+		if (ptr[0] == '\\')
+			backslash_count++;
+		else
+			backslash_count = 0;
+	}
+
+	/* skip any space at the end */
+	while (ptr > line && git__isspace(ptr[-1])) {
+		ptr--;
+	}
+	ptr[0] = '\0';
+
+	return quote_count;
+}
+
+
+static int parse_section_header_ext(git_config_parser *reader, const char *line, const char *base_name, char **section_name)
+{
+	int c, rpos;
+	char *first_quote, *last_quote;
+	git_buf buf = GIT_BUF_INIT;
+	size_t quoted_len, alloc_len, base_name_len = strlen(base_name);
+
+	/*
+	 * base_name is what came before the space. We should be at the
+	 * first quotation mark, except for now, line isn't being kept in
+	 * sync so we only really use it to calculate the length.
+	 */
+
+	first_quote = strchr(line, '"');
+	if (first_quote == NULL) {
+		set_parse_error(reader, 0, "Missing quotation marks in section header");
+		goto end_error;
+	}
+
+	last_quote = strrchr(line, '"');
+	quoted_len = last_quote - first_quote;
+
+	if (quoted_len == 0) {
+		set_parse_error(reader, 0, "Missing closing quotation mark in section header");
+		goto end_error;
+	}
+
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, base_name_len, quoted_len);
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, 2);
+
+	if (git_buf_grow(&buf, alloc_len) < 0 ||
+	    git_buf_printf(&buf, "%s.", base_name) < 0)
+		goto end_error;
+
+	rpos = 0;
+
+	line = first_quote;
+	c = line[++rpos];
+
+	/*
+	 * At the end of each iteration, whatever is stored in c will be
+	 * added to the string. In case of error, jump to out
+	 */
+	do {
+
+		switch (c) {
+		case 0:
+			set_parse_error(reader, 0, "Unexpected end-of-line in section header");
+			goto end_error;
+
+		case '"':
+			goto end_parse;
+
+		case '\\':
+			c = line[++rpos];
+
+			if (c == 0) {
+				set_parse_error(reader, rpos, "Unexpected end-of-line in section header");
+				goto end_error;
+			}
+
+		default:
+			break;
+		}
+
+		git_buf_putc(&buf, (char)c);
+		c = line[++rpos];
+	} while (line + rpos < last_quote);
+
+end_parse:
+	if (git_buf_oom(&buf))
+		goto end_error;
+
+	if (line[rpos] != '"' || line[rpos + 1] != ']') {
+		set_parse_error(reader, rpos, "Unexpected text after closing quotes");
+		git_buf_free(&buf);
+		return -1;
+	}
+
+	*section_name = git_buf_detach(&buf);
+	return 0;
+
+end_error:
+	git_buf_free(&buf);
+
+	return -1;
+}
+
+static int parse_section_header(git_config_parser *reader, char **section_out)
+{
+	char *name, *name_end;
+	int name_length, c, pos;
+	int result;
+	char *line;
+	size_t line_len;
+
+	git_parse_advance_ws(&reader->ctx);
+	line = git__strndup(reader->ctx.line, reader->ctx.line_len);
+	if (line == NULL)
+		return -1;
+
+	/* find the end of the variable's name */
+	name_end = strrchr(line, ']');
+	if (name_end == NULL) {
+		git__free(line);
+		set_parse_error(reader, 0, "Missing ']' in section header");
+		return -1;
+	}
+
+	GITERR_CHECK_ALLOC_ADD(&line_len, (size_t)(name_end - line), 1);
+	name = git__malloc(line_len);
+	GITERR_CHECK_ALLOC(name);
+
+	name_length = 0;
+	pos = 0;
+
+	/* Make sure we were given a section header */
+	c = line[pos++];
+	assert(c == '[');
+
+	c = line[pos++];
+
+	do {
+		if (git__isspace(c)){
+			name[name_length] = '\0';
+			result = parse_section_header_ext(reader, line, name, section_out);
+			git__free(line);
+			git__free(name);
+			return result;
+		}
+
+		if (!config_keychar(c) && c != '.') {
+			set_parse_error(reader, pos, "Unexpected character in header");
+			goto fail_parse;
+		}
+
+		name[name_length++] = (char)git__tolower(c);
+
+	} while ((c = line[pos++]) != ']');
+
+	if (line[pos - 1] != ']') {
+		set_parse_error(reader, pos, "Unexpected end of file");
+		goto fail_parse;
+	}
+
+	git__free(line);
+
+	name[name_length] = 0;
+	*section_out = name;
+
+	return 0;
+
+fail_parse:
+	git__free(line);
+	git__free(name);
+	return -1;
+}
+
+static int skip_bom(git_parse_ctx *parser)
+{
+	git_buf buf = GIT_BUF_INIT_CONST(parser->content, parser->content_len);
+	git_bom_t bom;
+	int bom_offset = git_buf_text_detect_bom(&bom, &buf);
+
+	if (bom == GIT_BOM_UTF8)
+		git_parse_advance_chars(parser, bom_offset);
+
+	/* TODO: reference implementation is pretty stupid with BoM */
+
+	return 0;
+}
+
+/*
+	(* basic types *)
+	digit = "0".."9"
+	integer = digit { digit }
+	alphabet = "a".."z" + "A" .. "Z"
+
+	section_char = alphabet | "." | "-"
+	extension_char = (* any character except newline *)
+	any_char = (* any character *)
+	variable_char = "alphabet" | "-"
+
+
+	(* actual grammar *)
+	config = { section }
+
+	section = header { definition }
+
+	header = "[" section [subsection | subsection_ext] "]"
+
+	subsection = "." section
+	subsection_ext = "\"" extension "\""
+
+	section = section_char { section_char }
+	extension = extension_char { extension_char }
+
+	definition = variable_name ["=" variable_value] "\n"
+
+	variable_name = variable_char { variable_char }
+	variable_value = string | boolean | integer
+
+	string = quoted_string | plain_string
+	quoted_string = "\"" plain_string "\""
+	plain_string = { any_char }
+
+	boolean = boolean_true | boolean_false
+	boolean_true = "yes" | "1" | "true" | "on"
+	boolean_false = "no" | "0" | "false" | "off"
+*/
+
+/* '\"' -> '"' etc */
+static int unescape_line(
+	char **out, bool *is_multi, const char *ptr, int quote_count)
+{
+	char *str, *fixed, *esc;
+	size_t ptr_len = strlen(ptr), alloc_len;
+
+	*is_multi = false;
+
+	if (GIT_ADD_SIZET_OVERFLOW(&alloc_len, ptr_len, 1) ||
+		(str = git__malloc(alloc_len)) == NULL) {
+		return -1;
+	}
+
+	fixed = str;
+
+	while (*ptr != '\0') {
+		if (*ptr == '"') {
+			quote_count++;
+		} else if (*ptr != '\\') {
+			*fixed++ = *ptr;
+		} else {
+			/* backslash, check the next char */
+			ptr++;
+			/* if we're at the end, it's a multiline, so keep the backslash */
+			if (*ptr == '\0') {
+				*is_multi = true;
+				goto done;
+			}
+			if ((esc = strchr(git_config_escapes, *ptr)) != NULL) {
+				*fixed++ = git_config_escaped[esc - git_config_escapes];
+			} else {
+				git__free(str);
+				giterr_set(GITERR_CONFIG, "invalid escape at %s", ptr);
+				return -1;
+			}
+		}
+		ptr++;
+	}
+
+done:
+	*fixed = '\0';
+	*out = str;
+
+	return 0;
+}
+
+static int parse_multiline_variable(git_config_parser *reader, git_buf *value, int in_quotes)
+{
+	char *line = NULL, *proc_line = NULL;
+	int quote_count;
+	bool multiline;
+
+	/* Check that the next line exists */
+	git_parse_advance_line(&reader->ctx);
+	line = git__strndup(reader->ctx.line, reader->ctx.line_len);
+	if (line == NULL)
+		return -1;
+
+	/* We've reached the end of the file, there is no continuation.
+	 * (this is not an error).
+	 */
+	if (line[0] == '\0') {
+		git__free(line);
+		return 0;
+	}
+
+	quote_count = strip_comments(line, !!in_quotes);
+
+	/* If it was just a comment, pretend it didn't exist */
+	if (line[0] == '\0') {
+		git__free(line);
+		return parse_multiline_variable(reader, value, quote_count);
+		/* TODO: unbounded recursion. This **could** be exploitable */
+	}
+
+	if (unescape_line(&proc_line, &multiline, line, in_quotes) < 0) {
+		git__free(line);
+		return -1;
+	}
+	/* add this line to the multiline var */
+
+	git_buf_puts(value, proc_line);
+	git__free(line);
+	git__free(proc_line);
+
+	/*
+	 * If we need to continue reading the next line, let's just
+	 * keep putting stuff in the buffer
+	 */
+	if (multiline)
+		return parse_multiline_variable(reader, value, quote_count);
+
+	return 0;
+}
+
+GIT_INLINE(bool) is_namechar(char c)
+{
+	return isalnum(c) || c == '-';
+}
+
+static int parse_name(
+	char **name, const char **value, git_config_parser *reader, const char *line)
+{
+	const char *name_end = line, *value_start;
+
+	*name = NULL;
+	*value = NULL;
+
+	while (*name_end && is_namechar(*name_end))
+		name_end++;
+
+	if (line == name_end) {
+		set_parse_error(reader, 0, "Invalid configuration key");
+		return -1;
+	}
+
+	value_start = name_end;
+
+	while (*value_start && git__isspace(*value_start))
+		value_start++;
+
+	if (*value_start == '=') {
+		*value = value_start + 1;
+	} else if (*value_start) {
+		set_parse_error(reader, 0, "Invalid configuration key");
+		return -1;
+	}
+
+	if ((*name = git__strndup(line, name_end - line)) == NULL)
+		return -1;
+
+	return 0;
+}
+
+static int parse_variable(git_config_parser *reader, char **var_name, char **var_value)
+{
+	const char *value_start = NULL;
+	char *line;
+	int quote_count;
+	bool multiline;
+
+	git_parse_advance_ws(&reader->ctx);
+	line = git__strndup(reader->ctx.line, reader->ctx.line_len);
+	if (line == NULL)
+		return -1;
+
+	quote_count = strip_comments(line, 0);
+
+	/* If there is no value, boolean true is assumed */
+	*var_value = NULL;
+
+	if (parse_name(var_name, &value_start, reader, line) < 0)
+		goto on_error;
+
+	/*
+	 * Now, let's try to parse the value
+	 */
+	if (value_start != NULL) {
+		while (git__isspace(value_start[0]))
+			value_start++;
+
+		if (unescape_line(var_value, &multiline, value_start, 0) < 0)
+			goto on_error;
+
+		if (multiline) {
+			git_buf multi_value = GIT_BUF_INIT;
+			git_buf_attach(&multi_value, *var_value, 0);
+
+			if (parse_multiline_variable(reader, &multi_value, quote_count) < 0 ||
+				git_buf_oom(&multi_value)) {
+				git_buf_free(&multi_value);
+				goto on_error;
+			}
+
+			*var_value = git_buf_detach(&multi_value);
+		}
+	}
+
+	git__free(line);
+	return 0;
+
+on_error:
+	git__free(*var_name);
+	git__free(line);
+	return -1;
+}
+
+int git_config_parse(
+	git_config_parser *parser,
+	git_config_parser_section_cb on_section,
+	git_config_parser_variable_cb on_variable,
+	git_config_parser_comment_cb on_comment,
+	git_config_parser_eof_cb on_eof,
+	void *data)
+{
+	git_parse_ctx *ctx;
+	char *current_section = NULL, *var_name, *var_value;
+	int result = 0;
+
+	ctx = &parser->ctx;
+
+	skip_bom(ctx);
+
+	for (; ctx->remain_len > 0; git_parse_advance_line(ctx)) {
+		const char *line_start = parser->ctx.line;
+		size_t line_len = parser->ctx.line_len;
+		char c;
+
+		/*
+		 * Get either first non-whitespace character or, if that does
+		 * not exist, the first whitespace character. This is required
+		 * to preserve whitespaces when writing back the file.
+		 */
+		if (git_parse_peek(&c, ctx, GIT_PARSE_PEEK_SKIP_WHITESPACE) < 0 &&
+		    git_parse_peek(&c, ctx, 0) < 0)
+			continue;
+
+		switch (c) {
+		case '[': /* section header, new section begins */
+			git__free(current_section);
+			current_section = NULL;
+
+			if ((result = parse_section_header(parser, &current_section)) == 0 && on_section) {
+				result = on_section(parser, current_section, line_start, line_len, data);
+			}
+			break;
+
+		case '\n': /* comment or whitespace-only */
+		case '\r':
+		case ' ':
+		case '\t':
+		case ';':
+		case '#':
+			if (on_comment) {
+				result = on_comment(parser, line_start, line_len, data);
+			}
+			break;
+
+		default: /* assume variable declaration */
+			if ((result = parse_variable(parser, &var_name, &var_value)) == 0 && on_variable) {
+				result = on_variable(parser, current_section, var_name, var_value, line_start, line_len, data);
+			}
+			break;
+		}
+
+		if (result < 0)
+			goto out;
+	}
+
+	if (on_eof)
+		result = on_eof(parser, current_section, data);
+
+out:
+	git__free(current_section);
+	return result;
+}

vendor/libgit2-sys/libgit2/src/config_parse.h

diff --git a/vendor/libgit2-sys/libgit2/src/config_parse.h b/vendor/libgit2-sys/libgit2/src/config_parse.h
new file mode 100644
index 0000000..d14a8e6
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/config_parse.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_config_parse_h__
+#define INCLUDE_config_parse_h__
+
+#include "common.h"
+#include "array.h"
+#include "oid.h"
+#include "parse.h"
+
+static const char *git_config_escapes = "ntb\"\\";
+static const char *git_config_escaped = "\n\t\b\"\\";
+
+typedef struct config_file {
+	git_oid checksum;
+	char *path;
+	git_array_t(struct config_file) includes;
+} git_config_file;
+
+typedef struct {
+	struct config_file *file;
+	git_parse_ctx ctx;
+} git_config_parser;
+
+typedef int (*git_config_parser_section_cb)(
+	git_config_parser *parser,
+	const char *current_section,
+	const char *line,
+	size_t line_len,
+	void *data);
+
+typedef int (*git_config_parser_variable_cb)(
+	git_config_parser *parser,
+	const char *current_section,
+	char *var_name,
+	char *var_value,
+	const char *line,
+	size_t line_len,
+	void *data);
+
+typedef int (*git_config_parser_comment_cb)(
+	git_config_parser *parser,
+	const char *line,
+	size_t line_len,
+	void *data);
+
+typedef int (*git_config_parser_eof_cb)(
+	git_config_parser *parser,
+	const char *current_section,
+	void *data);
+
+int git_config_parse(
+	git_config_parser *parser,
+	git_config_parser_section_cb on_section,
+	git_config_parser_variable_cb on_variable,
+	git_config_parser_comment_cb on_comment,
+	git_config_parser_eof_cb on_eof,
+	void *data);
+
+#endif

vendor/libgit2-sys/libgit2/src/crlf.c

diff --git a/vendor/libgit2-sys/libgit2/src/crlf.c b/vendor/libgit2-sys/libgit2/src/crlf.c
new file mode 100644
index 0000000..96cd2d8
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/crlf.c
@@ -0,0 +1,390 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "git2/attr.h"
+#include "git2/blob.h"
+#include "git2/index.h"
+#include "git2/sys/filter.h"
+
+#include "fileops.h"
+#include "hash.h"
+#include "filter.h"
+#include "buf_text.h"
+#include "repository.h"
+
+struct crlf_attrs {
+	int crlf_action;
+	int eol;
+	int auto_crlf;
+	int safe_crlf;
+};
+
+struct crlf_filter {
+	git_filter f;
+};
+
+static int check_crlf(const char *value)
+{
+	if (GIT_ATTR_TRUE(value))
+		return GIT_CRLF_TEXT;
+
+	if (GIT_ATTR_FALSE(value))
+		return GIT_CRLF_BINARY;
+
+	if (GIT_ATTR_UNSPECIFIED(value))
+		return GIT_CRLF_GUESS;
+
+	if (strcmp(value, "input") == 0)
+		return GIT_CRLF_INPUT;
+
+	if (strcmp(value, "auto") == 0)
+		return GIT_CRLF_AUTO;
+
+	return GIT_CRLF_GUESS;
+}
+
+static int check_eol(const char *value)
+{
+	if (GIT_ATTR_UNSPECIFIED(value))
+		return GIT_EOL_UNSET;
+
+	if (strcmp(value, "lf") == 0)
+		return GIT_EOL_LF;
+
+	if (strcmp(value, "crlf") == 0)
+		return GIT_EOL_CRLF;
+
+	return GIT_EOL_UNSET;
+}
+
+static int crlf_input_action(struct crlf_attrs *ca)
+{
+	if (ca->crlf_action == GIT_CRLF_BINARY)
+		return GIT_CRLF_BINARY;
+
+	if (ca->eol == GIT_EOL_LF)
+		return GIT_CRLF_INPUT;
+
+	if (ca->crlf_action == GIT_CRLF_AUTO)
+		return GIT_CRLF_AUTO;
+
+	if (ca->eol == GIT_EOL_CRLF)
+		return GIT_CRLF_CRLF;
+
+	return ca->crlf_action;
+}
+
+static int has_cr_in_index(const git_filter_source *src)
+{
+	git_repository *repo = git_filter_source_repo(src);
+	const char *path = git_filter_source_path(src);
+	git_index *index;
+	const git_index_entry *entry;
+	git_blob *blob;
+	const void *blobcontent;
+	git_off_t blobsize;
+	bool found_cr;
+
+	if (!path)
+		return false;
+
+	if (git_repository_index__weakptr(&index, repo) < 0) {
+		giterr_clear();
+		return false;
+	}
+
+	if (!(entry = git_index_get_bypath(index, path, 0)) &&
+		!(entry = git_index_get_bypath(index, path, 1)))
+		return false;
+
+	if (!S_ISREG(entry->mode)) /* don't crlf filter non-blobs */
+		return true;
+
+	if (git_blob_lookup(&blob, repo, &entry->id) < 0)
+		return false;
+
+	blobcontent = git_blob_rawcontent(blob);
+	blobsize    = git_blob_rawsize(blob);
+	if (!git__is_sizet(blobsize))
+		blobsize = (size_t)-1;
+
+	found_cr = (blobcontent != NULL &&
+		blobsize > 0 &&
+		memchr(blobcontent, '\r', (size_t)blobsize) != NULL);
+
+	git_blob_free(blob);
+	return found_cr;
+}
+
+static int crlf_apply_to_odb(
+	struct crlf_attrs *ca,
+	git_buf *to,
+	const git_buf *from,
+	const git_filter_source *src)
+{
+	/* Empty file? Nothing to do */
+	if (!git_buf_len(from))
+		return 0;
+
+	/* Heuristics to see if we can skip the conversion.
+	 * Straight from Core Git.
+	 */
+	if (ca->crlf_action == GIT_CRLF_AUTO || ca->crlf_action == GIT_CRLF_GUESS) {
+		git_buf_text_stats stats;
+
+		/* Check heuristics for binary vs text - returns true if binary */
+		if (git_buf_text_gather_stats(&stats, from, false))
+			return GIT_PASSTHROUGH;
+
+		/* If there are no CR characters to filter out, then just pass */
+		if (!stats.cr)
+			return GIT_PASSTHROUGH;
+
+		/* If safecrlf is enabled, sanity-check the result. */
+		if (stats.cr != stats.crlf || stats.lf != stats.crlf) {
+			switch (ca->safe_crlf) {
+			case GIT_SAFE_CRLF_FAIL:
+				giterr_set(
+					GITERR_FILTER, "LF would be replaced by CRLF in '%s'",
+					git_filter_source_path(src));
+				return -1;
+			case GIT_SAFE_CRLF_WARN:
+				/* TODO: issue warning when warning API is available */;
+				break;
+			default:
+				break;
+			}
+		}
+
+		/*
+		 * We're currently not going to even try to convert stuff
+		 * that has bare CR characters. Does anybody do that crazy
+		 * stuff?
+		 */
+		if (stats.cr != stats.crlf)
+			return GIT_PASSTHROUGH;
+
+		if (ca->crlf_action == GIT_CRLF_GUESS) {
+			/*
+			 * If the file in the index has any CR in it, do not convert.
+			 * This is the new safer autocrlf handling.
+			 */
+			if (has_cr_in_index(src))
+				return GIT_PASSTHROUGH;
+		}
+
+		if (!stats.cr)
+			return GIT_PASSTHROUGH;
+	}
+
+	/* Actually drop the carriage returns */
+	return git_buf_text_crlf_to_lf(to, from);
+}
+
+static const char *line_ending(struct crlf_attrs *ca)
+{
+	switch (ca->crlf_action) {
+	case GIT_CRLF_BINARY:
+	case GIT_CRLF_INPUT:
+		return "\n";
+
+	case GIT_CRLF_CRLF:
+		return "\r\n";
+
+	case GIT_CRLF_GUESS:
+		if (ca->auto_crlf == GIT_AUTO_CRLF_FALSE)
+			return "\n";
+		break;
+
+	case GIT_CRLF_AUTO:
+		if (ca->eol == GIT_EOL_CRLF)
+			return "\r\n";
+	case GIT_CRLF_TEXT:
+		break;
+
+	default:
+		goto line_ending_error;
+	}
+
+	if (ca->auto_crlf == GIT_AUTO_CRLF_TRUE)
+		return "\r\n";
+	else if (ca->auto_crlf == GIT_AUTO_CRLF_INPUT)
+		return "\n";
+	else if (ca->eol == GIT_EOL_UNSET)
+		return GIT_EOL_NATIVE == GIT_EOL_CRLF ? "\r\n" : "\n";
+	else if (ca->eol == GIT_EOL_LF)
+		return "\n";
+	else if (ca->eol == GIT_EOL_CRLF)
+		return "\r\n";
+
+line_ending_error:
+	giterr_set(GITERR_INVALID, "invalid input to line ending filter");
+	return NULL;
+}
+
+static int crlf_apply_to_workdir(
+	struct crlf_attrs *ca, git_buf *to, const git_buf *from)
+{
+	git_buf_text_stats stats;
+	const char *workdir_ending = NULL;
+	bool is_binary;
+
+	/* Empty file? Nothing to do. */
+	if (git_buf_len(from) == 0)
+		return 0;
+
+	/* Determine proper line ending */
+	workdir_ending = line_ending(ca);
+	if (!workdir_ending)
+		return -1;
+
+	/* only LF->CRLF conversion is supported, do nothing on LF platforms */
+	if (strcmp(workdir_ending, "\r\n") != 0)
+		return GIT_PASSTHROUGH;
+
+	/* If there are no LFs, or all LFs are part of a CRLF, nothing to do */
+	is_binary = git_buf_text_gather_stats(&stats, from, false);
+
+	if (stats.lf == 0 || stats.lf == stats.crlf)
+		return GIT_PASSTHROUGH;
+
+	if (ca->crlf_action == GIT_CRLF_AUTO ||
+		ca->crlf_action == GIT_CRLF_GUESS) {
+
+		/* If we have any existing CR or CRLF line endings, do nothing */
+		if (stats.cr > 0 && stats.crlf > 0)
+			return GIT_PASSTHROUGH;
+
+		/* If we have bare CR characters, do nothing */
+		if (stats.cr != stats.crlf)
+			return GIT_PASSTHROUGH;
+
+		/* Don't filter binary files */
+		if (is_binary)
+			return GIT_PASSTHROUGH;
+	}
+
+	return git_buf_text_lf_to_crlf(to, from);
+}
+
+static int crlf_check(
+	git_filter        *self,
+	void              **payload, /* points to NULL ptr on entry, may be set */
+	const git_filter_source *src,
+	const char **attr_values)
+{
+	int error;
+	struct crlf_attrs ca;
+
+	GIT_UNUSED(self);
+
+	if (!attr_values) {
+		ca.crlf_action = GIT_CRLF_GUESS;
+		ca.eol = GIT_EOL_UNSET;
+	} else {
+		ca.crlf_action = check_crlf(attr_values[2]); /* text */
+		if (ca.crlf_action == GIT_CRLF_GUESS)
+			ca.crlf_action = check_crlf(attr_values[0]); /* clrf */
+		ca.eol = check_eol(attr_values[1]); /* eol */
+	}
+	ca.auto_crlf = GIT_AUTO_CRLF_DEFAULT;
+	ca.safe_crlf = GIT_SAFE_CRLF_DEFAULT;
+
+	/*
+	 * Use the core Git logic to see if we should perform CRLF for this file
+	 * based on its attributes & the value of `core.autocrlf`
+	 */
+	ca.crlf_action = crlf_input_action(&ca);
+
+	if (ca.crlf_action == GIT_CRLF_BINARY)
+		return GIT_PASSTHROUGH;
+
+	if (ca.crlf_action == GIT_CRLF_GUESS ||
+		((ca.crlf_action == GIT_CRLF_AUTO ||
+		ca.crlf_action == GIT_CRLF_TEXT) &&
+		git_filter_source_mode(src) == GIT_FILTER_SMUDGE)) {
+
+		error = git_repository__cvar(
+			&ca.auto_crlf, git_filter_source_repo(src), GIT_CVAR_AUTO_CRLF);
+		if (error < 0)
+			return error;
+
+		if (ca.crlf_action == GIT_CRLF_GUESS &&
+			ca.auto_crlf == GIT_AUTO_CRLF_FALSE)
+			return GIT_PASSTHROUGH;
+
+		if (ca.auto_crlf == GIT_AUTO_CRLF_INPUT &&
+			ca.eol != GIT_EOL_CRLF &&
+			git_filter_source_mode(src) == GIT_FILTER_SMUDGE)
+			return GIT_PASSTHROUGH;
+	}
+
+	if (git_filter_source_mode(src) == GIT_FILTER_CLEAN) {
+		error = git_repository__cvar(
+			&ca.safe_crlf, git_filter_source_repo(src), GIT_CVAR_SAFE_CRLF);
+		if (error < 0)
+			return error;
+
+		/* downgrade FAIL to WARN if ALLOW_UNSAFE option is used */
+		if ((git_filter_source_flags(src) & GIT_FILTER_ALLOW_UNSAFE) &&
+			ca.safe_crlf == GIT_SAFE_CRLF_FAIL)
+			ca.safe_crlf = GIT_SAFE_CRLF_WARN;
+	}
+
+	*payload = git__malloc(sizeof(ca));
+	GITERR_CHECK_ALLOC(*payload);
+	memcpy(*payload, &ca, sizeof(ca));
+
+	return 0;
+}
+
+static int crlf_apply(
+	git_filter    *self,
+	void         **payload, /* may be read and/or set */
+	git_buf       *to,
+	const git_buf *from,
+	const git_filter_source *src)
+{
+	/* initialize payload in case `check` was bypassed */
+	if (!*payload) {
+		int error = crlf_check(self, payload, src, NULL);
+		if (error < 0)
+			return error;
+	}
+
+	if (git_filter_source_mode(src) == GIT_FILTER_SMUDGE)
+		return crlf_apply_to_workdir(*payload, to, from);
+	else
+		return crlf_apply_to_odb(*payload, to, from, src);
+}
+
+static void crlf_cleanup(
+	git_filter *self,
+	void       *payload)
+{
+	GIT_UNUSED(self);
+	git__free(payload);
+}
+
+git_filter *git_crlf_filter_new(void)
+{
+	struct crlf_filter *f = git__calloc(1, sizeof(struct crlf_filter));
+	if (f == NULL)
+		return NULL;
+
+	f->f.version = GIT_FILTER_VERSION;
+	f->f.attributes = "crlf eol text";
+	f->f.initialize = NULL;
+	f->f.shutdown = git_filter_free;
+	f->f.check    = crlf_check;
+	f->f.apply    = crlf_apply;
+	f->f.cleanup  = crlf_cleanup;
+
+	return (git_filter *)f;
+}

vendor/libgit2-sys/libgit2/src/date.c

diff --git a/vendor/libgit2-sys/libgit2/src/date.c b/vendor/libgit2-sys/libgit2/src/date.c
new file mode 100644
index 0000000..0e1b31a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/date.c
@@ -0,0 +1,904 @@
+/*
+ * GIT - The information manager from hell
+ *
+ * Copyright (C) Linus Torvalds, 2005
+ */
+
+#include "common.h"
+
+#ifndef GIT_WIN32
+#include <sys/time.h>
+#endif
+
+#include "util.h"
+#include "cache.h"
+#include "posix.h"
+
+#include <ctype.h>
+#include <time.h>
+
+typedef enum {
+	DATE_NORMAL = 0,
+	DATE_RELATIVE,
+	DATE_SHORT,
+	DATE_LOCAL,
+	DATE_ISO8601,
+	DATE_RFC2822,
+	DATE_RAW
+} date_mode;
+
+/*
+ * This is like mktime, but without normalization of tm_wday and tm_yday.
+ */
+static git_time_t tm_to_time_t(const struct tm *tm)
+{
+	static const int mdays[] = {
+	    0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
+	};
+	int year = tm->tm_year - 70;
+	int month = tm->tm_mon;
+	int day = tm->tm_mday;
+
+	if (year < 0 || year > 129) /* algo only works for 1970-2099 */
+		return -1;
+	if (month < 0 || month > 11) /* array bounds */
+		return -1;
+	if (month < 2 || (year + 2) % 4)
+		day--;
+	if (tm->tm_hour < 0 || tm->tm_min < 0 || tm->tm_sec < 0)
+		return -1;
+	return (year * 365 + (year + 1) / 4 + mdays[month] + day) * 24*60*60UL +
+		tm->tm_hour * 60*60 + tm->tm_min * 60 + tm->tm_sec;
+}
+
+static const char *month_names[] = {
+	"January", "February", "March", "April", "May", "June",
+	"July", "August", "September", "October", "November", "December"
+};
+
+static const char *weekday_names[] = {
+	"Sundays", "Mondays", "Tuesdays", "Wednesdays", "Thursdays", "Fridays", "Saturdays"
+};
+
+
+
+/*
+ * Check these. And note how it doesn't do the summer-time conversion.
+ *
+ * In my world, it's always summer, and things are probably a bit off
+ * in other ways too.
+ */
+static const struct {
+	const char *name;
+	int offset;
+	int dst;
+} timezone_names[] = {
+	{ "IDLW", -12, 0, },	/* International Date Line West */
+	{ "NT",   -11, 0, },	/* Nome */
+	{ "CAT",  -10, 0, },	/* Central Alaska */
+	{ "HST",  -10, 0, },	/* Hawaii Standard */
+	{ "HDT",  -10, 1, },	/* Hawaii Daylight */
+	{ "YST",   -9, 0, },	/* Yukon Standard */
+	{ "YDT",   -9, 1, },	/* Yukon Daylight */
+	{ "PST",   -8, 0, },	/* Pacific Standard */
+	{ "PDT",   -8, 1, },	/* Pacific Daylight */
+	{ "MST",   -7, 0, },	/* Mountain Standard */
+	{ "MDT",   -7, 1, },	/* Mountain Daylight */
+	{ "CST",   -6, 0, },	/* Central Standard */
+	{ "CDT",   -6, 1, },	/* Central Daylight */
+	{ "EST",   -5, 0, },	/* Eastern Standard */
+	{ "EDT",   -5, 1, },	/* Eastern Daylight */
+	{ "AST",   -3, 0, },	/* Atlantic Standard */
+	{ "ADT",   -3, 1, },	/* Atlantic Daylight */
+	{ "WAT",   -1, 0, },	/* West Africa */
+
+	{ "GMT",    0, 0, },	/* Greenwich Mean */
+	{ "UTC",    0, 0, },	/* Universal (Coordinated) */
+	{ "Z",      0, 0, },    /* Zulu, alias for UTC */
+
+	{ "WET",    0, 0, },	/* Western European */
+	{ "BST",    0, 1, },	/* British Summer */
+	{ "CET",   +1, 0, },	/* Central European */
+	{ "MET",   +1, 0, },	/* Middle European */
+	{ "MEWT",  +1, 0, },	/* Middle European Winter */
+	{ "MEST",  +1, 1, },	/* Middle European Summer */
+	{ "CEST",  +1, 1, },	/* Central European Summer */
+	{ "MESZ",  +1, 1, },	/* Middle European Summer */
+	{ "FWT",   +1, 0, },	/* French Winter */
+	{ "FST",   +1, 1, },	/* French Summer */
+	{ "EET",   +2, 0, },	/* Eastern Europe */
+	{ "EEST",  +2, 1, },	/* Eastern European Daylight */
+	{ "WAST",  +7, 0, },	/* West Australian Standard */
+	{ "WADT",  +7, 1, },	/* West Australian Daylight */
+	{ "CCT",   +8, 0, },	/* China Coast */
+	{ "JST",   +9, 0, },	/* Japan Standard */
+	{ "EAST", +10, 0, },	/* Eastern Australian Standard */
+	{ "EADT", +10, 1, },	/* Eastern Australian Daylight */
+	{ "GST",  +10, 0, },	/* Guam Standard */
+	{ "NZT",  +12, 0, },	/* New Zealand */
+	{ "NZST", +12, 0, },	/* New Zealand Standard */
+	{ "NZDT", +12, 1, },	/* New Zealand Daylight */
+	{ "IDLE", +12, 0, },	/* International Date Line East */
+};
+
+static size_t match_string(const char *date, const char *str)
+{
+	size_t i = 0;
+
+	for (i = 0; *date; date++, str++, i++) {
+		if (*date == *str)
+			continue;
+		if (toupper(*date) == toupper(*str))
+			continue;
+		if (!isalnum(*date))
+			break;
+		return 0;
+	}
+	return i;
+}
+
+static int skip_alpha(const char *date)
+{
+	int i = 0;
+	do {
+		i++;
+	} while (isalpha(date[i]));
+	return i;
+}
+
+/*
+* Parse month, weekday, or timezone name
+*/
+static size_t match_alpha(const char *date, struct tm *tm, int *offset)
+{
+	unsigned int i;
+
+	for (i = 0; i < 12; i++) {
+		size_t match = match_string(date, month_names[i]);
+		if (match >= 3) {
+			tm->tm_mon = i;
+			return match;
+		}
+	}
+
+	for (i = 0; i < 7; i++) {
+		size_t match = match_string(date, weekday_names[i]);
+		if (match >= 3) {
+			tm->tm_wday = i;
+			return match;
+		}
+	}
+
+	for (i = 0; i < ARRAY_SIZE(timezone_names); i++) {
+		size_t match = match_string(date, timezone_names[i].name);
+		if (match >= 3 || match == strlen(timezone_names[i].name)) {
+			int off = timezone_names[i].offset;
+
+			/* This is bogus, but we like summer */
+			off += timezone_names[i].dst;
+
+			/* Only use the tz name offset if we don't have anything better */
+			if (*offset == -1)
+				*offset = 60*off;
+
+			return match;
+		}
+	}
+
+	if (match_string(date, "PM") == 2) {
+		tm->tm_hour = (tm->tm_hour % 12) + 12;
+		return 2;
+	}
+
+	if (match_string(date, "AM") == 2) {
+		tm->tm_hour = (tm->tm_hour % 12) + 0;
+		return 2;
+	}
+
+	/* BAD */
+	return skip_alpha(date);
+}
+
+static int is_date(int year, int month, int day, struct tm *now_tm, time_t now, struct tm *tm)
+{
+	if (month > 0 && month < 13 && day > 0 && day < 32) {
+		struct tm check = *tm;
+		struct tm *r = (now_tm ? &check : tm);
+		time_t specified;
+
+		r->tm_mon = month - 1;
+		r->tm_mday = day;
+		if (year == -1) {
+			if (!now_tm)
+				return 1;
+			r->tm_year = now_tm->tm_year;
+		}
+		else if (year >= 1970 && year < 2100)
+			r->tm_year = year - 1900;
+		else if (year > 70 && year < 100)
+			r->tm_year = year;
+		else if (year < 38)
+			r->tm_year = year + 100;
+		else
+			return 0;
+		if (!now_tm)
+			return 1;
+
+		specified = tm_to_time_t(r);
+
+		/* Be it commit time or author time, it does not make
+		 * sense to specify timestamp way into the future.  Make
+		 * sure it is not later than ten days from now...
+		 */
+		if (now + 10*24*3600 < specified)
+			return 0;
+		tm->tm_mon = r->tm_mon;
+		tm->tm_mday = r->tm_mday;
+		if (year != -1)
+			tm->tm_year = r->tm_year;
+		return 1;
+	}
+	return 0;
+}
+
+static size_t match_multi_number(unsigned long num, char c, const char *date, char *end, struct tm *tm)
+{
+	time_t now;
+	struct tm now_tm;
+	struct tm *refuse_future;
+	long num2, num3;
+
+	num2 = strtol(end+1, &end, 10);
+	num3 = -1;
+	if (*end == c && isdigit(end[1]))
+		num3 = strtol(end+1, &end, 10);
+
+	/* Time? Date? */
+	switch (c) {
+	case ':':
+		if (num3 < 0)
+			num3 = 0;
+		if (num < 25 && num2 >= 0 && num2 < 60 && num3 >= 0 && num3 <= 60) {
+			tm->tm_hour = num;
+			tm->tm_min = num2;
+			tm->tm_sec = num3;
+			break;
+		}
+		return 0;
+
+	case '-':
+	case '/':
+	case '.':
+		now = time(NULL);
+		refuse_future = NULL;
+		if (p_gmtime_r(&now, &now_tm))
+			refuse_future = &now_tm;
+
+		if (num > 70) {
+			/* yyyy-mm-dd? */
+			if (is_date(num, num2, num3, refuse_future, now, tm))
+				break;
+			/* yyyy-dd-mm? */
+			if (is_date(num, num3, num2, refuse_future, now, tm))
+				break;
+		}
+		/* Our eastern European friends say dd.mm.yy[yy]
+		 * is the norm there, so giving precedence to
+		 * mm/dd/yy[yy] form only when separator is not '.'
+		 */
+		if (c != '.' &&
+		    is_date(num3, num, num2, refuse_future, now, tm))
+			break;
+		/* European dd.mm.yy[yy] or funny US dd/mm/yy[yy] */
+		if (is_date(num3, num2, num, refuse_future, now, tm))
+			break;
+		/* Funny European mm.dd.yy */
+		if (c == '.' &&
+		    is_date(num3, num, num2, refuse_future, now, tm))
+			break;
+		return 0;
+	}
+	return end - date;
+}
+
+/*
+ * Have we filled in any part of the time/date yet?
+ * We just do a binary 'and' to see if the sign bit
+ * is set in all the values.
+ */
+static int nodate(struct tm *tm)
+{
+	return (tm->tm_year &
+		tm->tm_mon &
+		tm->tm_mday &
+		tm->tm_hour &
+		tm->tm_min &
+		tm->tm_sec) < 0;
+}
+
+/*
+ * We've seen a digit. Time? Year? Date?
+ */
+static size_t match_digit(const char *date, struct tm *tm, int *offset, int *tm_gmt)
+{
+	size_t n;
+	char *end;
+	unsigned long num;
+
+	num = strtoul(date, &end, 10);
+
+	/*
+	 * Seconds since 1970? We trigger on that for any numbers with
+	 * more than 8 digits. This is because we don't want to rule out
+	 * numbers like 20070606 as a YYYYMMDD date.
+	 */
+	if (num >= 100000000 && nodate(tm)) {
+		time_t time = num;
+		if (p_gmtime_r(&time, tm)) {
+			*tm_gmt = 1;
+			return end - date;
+		}
+	}
+
+	/*
+	 * Check for special formats: num[-.:/]num[same]num
+	 */
+	switch (*end) {
+	case ':':
+	case '.':
+	case '/':
+	case '-':
+		if (isdigit(end[1])) {
+			size_t match = match_multi_number(num, *end, date, end, tm);
+			if (match)
+				return match;
+		}
+	}
+
+	/*
+	 * None of the special formats? Try to guess what
+	 * the number meant. We use the number of digits
+	 * to make a more educated guess..
+	 */
+	n = 0;
+	do {
+		n++;
+	} while (isdigit(date[n]));
+
+	/* Four-digit year or a timezone? */
+	if (n == 4) {
+		if (num <= 1400 && *offset == -1) {
+			unsigned int minutes = num % 100;
+			unsigned int hours = num / 100;
+			*offset = hours*60 + minutes;
+		} else if (num > 1900 && num < 2100)
+			tm->tm_year = num - 1900;
+		return n;
+	}
+
+	/*
+	 * Ignore lots of numerals. We took care of 4-digit years above.
+	 * Days or months must be one or two digits.
+	 */
+	if (n > 2)
+		return n;
+
+	/*
+	 * NOTE! We will give precedence to day-of-month over month or
+	 * year numbers in the 1-12 range. So 05 is always "mday 5",
+	 * unless we already have a mday..
+	 *
+	 * IOW, 01 Apr 05 parses as "April 1st, 2005".
+	 */
+	if (num > 0 && num < 32 && tm->tm_mday < 0) {
+		tm->tm_mday = num;
+		return n;
+	}
+
+	/* Two-digit year? */
+	if (n == 2 && tm->tm_year < 0) {
+		if (num < 10 && tm->tm_mday >= 0) {
+			tm->tm_year = num + 100;
+			return n;
+		}
+		if (num >= 70) {
+			tm->tm_year = num;
+			return n;
+		}
+	}
+
+	if (num > 0 && num < 13 && tm->tm_mon < 0)
+		tm->tm_mon = num-1;
+
+	return n;
+}
+
+static size_t match_tz(const char *date, int *offp)
+{
+	char *end;
+	int hour = strtoul(date + 1, &end, 10);
+	size_t n = end - (date + 1);
+	int min = 0;
+
+	if (n == 4) {
+		/* hhmm */
+		min = hour % 100;
+		hour = hour / 100;
+	} else if (n != 2) {
+		min = 99; /* random stuff */
+	} else if (*end == ':') {
+		/* hh:mm? */
+		min = strtoul(end + 1, &end, 10);
+		if (end - (date + 1) != 5)
+			min = 99; /* random stuff */
+	} /* otherwise we parsed "hh" */
+
+	/*
+	 * Don't accept any random stuff. Even though some places have
+	 * offset larger than 12 hours (e.g. Pacific/Kiritimati is at
+	 * UTC+14), there is something wrong if hour part is much
+	 * larger than that. We might also want to check that the
+	 * minutes are divisible by 15 or something too. (Offset of
+	 * Kathmandu, Nepal is UTC+5:45)
+	 */
+	if (min < 60 && hour < 24) {
+		int offset = hour * 60 + min;
+		if (*date == '-')
+			offset = -offset;
+		*offp = offset;
+	}
+	return end - date;
+}
+
+/*
+ * Parse a string like "0 +0000" as ancient timestamp near epoch, but
+ * only when it appears not as part of any other string.
+ */
+static int match_object_header_date(const char *date, git_time_t *timestamp, int *offset)
+{
+	char *end;
+	unsigned long stamp;
+	int ofs;
+
+	if (*date < '0' || '9' <= *date)
+		return -1;
+	stamp = strtoul(date, &end, 10);
+	if (*end != ' ' || stamp == ULONG_MAX || (end[1] != '+' && end[1] != '-'))
+		return -1;
+	date = end + 2;
+	ofs = strtol(date, &end, 10);
+	if ((*end != '\0' && (*end != '\n')) || end != date + 4)
+		return -1;
+	ofs = (ofs / 100) * 60 + (ofs % 100);
+	if (date[-1] == '-')
+		ofs = -ofs;
+	*timestamp = stamp;
+	*offset = ofs;
+	return 0;
+}
+
+/* Gr. strptime is crap for this; it doesn't have a way to require RFC2822
+   (i.e. English) day/month names, and it doesn't work correctly with %z. */
+static int parse_date_basic(const char *date, git_time_t *timestamp, int *offset)
+{
+	struct tm tm;
+	int tm_gmt;
+	git_time_t dummy_timestamp;
+	int dummy_offset;
+
+	if (!timestamp)
+		timestamp = &dummy_timestamp;
+	if (!offset)
+		offset = &dummy_offset;
+
+	memset(&tm, 0, sizeof(tm));
+	tm.tm_year = -1;
+	tm.tm_mon = -1;
+	tm.tm_mday = -1;
+	tm.tm_isdst = -1;
+	tm.tm_hour = -1;
+	tm.tm_min = -1;
+	tm.tm_sec = -1;
+	*offset = -1;
+	tm_gmt = 0;
+
+	if (*date == '@' &&
+	    !match_object_header_date(date + 1, timestamp, offset))
+		return 0; /* success */
+	for (;;) {
+		size_t match = 0;
+		unsigned char c = *date;
+
+		/* Stop at end of string or newline */
+		if (!c || c == '\n')
+			break;
+
+		if (isalpha(c))
+			match = match_alpha(date, &tm, offset);
+		else if (isdigit(c))
+			match = match_digit(date, &tm, offset, &tm_gmt);
+		else if ((c == '-' || c == '+') && isdigit(date[1]))
+			match = match_tz(date, offset);
+
+		if (!match) {
+			/* BAD */
+			match = 1;
+		}
+
+		date += match;
+	}
+
+	/* mktime uses local timezone */
+	*timestamp = tm_to_time_t(&tm);
+	if (*offset == -1)
+		*offset = (int)((time_t)*timestamp - mktime(&tm)) / 60;
+
+	if (*timestamp == (git_time_t)-1)
+		return -1;
+
+	if (!tm_gmt)
+		*timestamp -= *offset * 60;
+	return 0; /* success */
+}
+
+
+/*
+ * Relative time update (eg "2 days ago").  If we haven't set the time
+ * yet, we need to set it from current time.
+ */
+static git_time_t update_tm(struct tm *tm, struct tm *now, unsigned long sec)
+{
+	time_t n;
+
+	if (tm->tm_mday < 0)
+		tm->tm_mday = now->tm_mday;
+	if (tm->tm_mon < 0)
+		tm->tm_mon = now->tm_mon;
+	if (tm->tm_year < 0) {
+		tm->tm_year = now->tm_year;
+		if (tm->tm_mon > now->tm_mon)
+			tm->tm_year--;
+	}
+
+	n = mktime(tm) - sec;
+	p_localtime_r(&n, tm);
+	return n;
+}
+
+static void date_now(struct tm *tm, struct tm *now, int *num)
+{
+   GIT_UNUSED(num);
+	update_tm(tm, now, 0);
+}
+
+static void date_yesterday(struct tm *tm, struct tm *now, int *num)
+{
+   GIT_UNUSED(num);
+	update_tm(tm, now, 24*60*60);
+}
+
+static void date_time(struct tm *tm, struct tm *now, int hour)
+{
+	if (tm->tm_hour < hour)
+		date_yesterday(tm, now, NULL);
+	tm->tm_hour = hour;
+	tm->tm_min = 0;
+	tm->tm_sec = 0;
+}
+
+static void date_midnight(struct tm *tm, struct tm *now, int *num)
+{
+   GIT_UNUSED(num);
+	date_time(tm, now, 0);
+}
+
+static void date_noon(struct tm *tm, struct tm *now, int *num)
+{
+   GIT_UNUSED(num);
+	date_time(tm, now, 12);
+}
+
+static void date_tea(struct tm *tm, struct tm *now, int *num)
+{
+   GIT_UNUSED(num);
+	date_time(tm, now, 17);
+}
+
+static void date_pm(struct tm *tm, struct tm *now, int *num)
+{
+	int hour, n = *num;
+	*num = 0;
+   GIT_UNUSED(now);
+
+	hour = tm->tm_hour;
+	if (n) {
+		hour = n;
+		tm->tm_min = 0;
+		tm->tm_sec = 0;
+	}
+	tm->tm_hour = (hour % 12) + 12;
+}
+
+static void date_am(struct tm *tm, struct tm *now, int *num)
+{
+	int hour, n = *num;
+	*num = 0;
+   GIT_UNUSED(now);
+
+	hour = tm->tm_hour;
+	if (n) {
+		hour = n;
+		tm->tm_min = 0;
+		tm->tm_sec = 0;
+	}
+	tm->tm_hour = (hour % 12);
+}
+
+static void date_never(struct tm *tm, struct tm *now, int *num)
+{
+	time_t n = 0;
+   GIT_UNUSED(now);
+   GIT_UNUSED(num);
+	p_localtime_r(&n, tm);
+}
+
+static const struct special {
+	const char *name;
+	void (*fn)(struct tm *, struct tm *, int *);
+} special[] = {
+	{ "yesterday", date_yesterday },
+	{ "noon", date_noon },
+	{ "midnight", date_midnight },
+	{ "tea", date_tea },
+	{ "PM", date_pm },
+	{ "AM", date_am },
+	{ "never", date_never },
+	{ "now", date_now },
+	{ NULL }
+};
+
+static const char *number_name[] = {
+	"zero", "one", "two", "three", "four",
+	"five", "six", "seven", "eight", "nine", "ten",
+};
+
+static const struct typelen {
+	const char *type;
+	int length;
+} typelen[] = {
+	{ "seconds", 1 },
+	{ "minutes", 60 },
+	{ "hours", 60*60 },
+	{ "days", 24*60*60 },
+	{ "weeks", 7*24*60*60 },
+	{ NULL }
+};
+
+static const char *approxidate_alpha(const char *date, struct tm *tm, struct tm *now, int *num, int *touched)
+{
+	const struct typelen *tl;
+	const struct special *s;
+	const char *end = date;
+	int i;
+
+	while (isalpha(*++end))
+		/* scan to non-alpha */;
+
+	for (i = 0; i < 12; i++) {
+		size_t match = match_string(date, month_names[i]);
+		if (match >= 3) {
+			tm->tm_mon = i;
+			*touched = 1;
+			return end;
+		}
+	}
+
+	for (s = special; s->name; s++) {
+		size_t len = strlen(s->name);
+		if (match_string(date, s->name) == len) {
+			s->fn(tm, now, num);
+			*touched = 1;
+			return end;
+		}
+	}
+
+	if (!*num) {
+		for (i = 1; i < 11; i++) {
+			size_t len = strlen(number_name[i]);
+			if (match_string(date, number_name[i]) == len) {
+				*num = i;
+				*touched = 1;
+				return end;
+			}
+		}
+		if (match_string(date, "last") == 4) {
+			*num = 1;
+			*touched = 1;
+		}
+		return end;
+	}
+
+	tl = typelen;
+	while (tl->type) {
+		size_t len = strlen(tl->type);
+		if (match_string(date, tl->type) >= len-1) {
+			update_tm(tm, now, tl->length * *num);
+			*num = 0;
+			*touched = 1;
+			return end;
+		}
+		tl++;
+	}
+
+	for (i = 0; i < 7; i++) {
+		size_t match = match_string(date, weekday_names[i]);
+		if (match >= 3) {
+			int diff, n = *num -1;
+			*num = 0;
+
+			diff = tm->tm_wday - i;
+			if (diff <= 0)
+				n++;
+			diff += 7*n;
+
+			update_tm(tm, now, diff * 24 * 60 * 60);
+			*touched = 1;
+			return end;
+		}
+	}
+
+	if (match_string(date, "months") >= 5) {
+		int n;
+		update_tm(tm, now, 0); /* fill in date fields if needed */
+		n = tm->tm_mon - *num;
+		*num = 0;
+		while (n < 0) {
+			n += 12;
+			tm->tm_year--;
+		}
+		tm->tm_mon = n;
+		*touched = 1;
+		return end;
+	}
+
+	if (match_string(date, "years") >= 4) {
+		update_tm(tm, now, 0); /* fill in date fields if needed */
+		tm->tm_year -= *num;
+		*num = 0;
+		*touched = 1;
+		return end;
+	}
+
+	return end;
+}
+
+static const char *approxidate_digit(const char *date, struct tm *tm, int *num)
+{
+	char *end;
+	unsigned long number = strtoul(date, &end, 10);
+
+	switch (*end) {
+	case ':':
+	case '.':
+	case '/':
+	case '-':
+		if (isdigit(end[1])) {
+			size_t match = match_multi_number(number, *end, date, end, tm);
+			if (match)
+				return date + match;
+		}
+	}
+
+	/* Accept zero-padding only for small numbers ("Dec 02", never "Dec 0002") */
+	if (date[0] != '0' || end - date <= 2)
+		*num = number;
+	return end;
+}
+
+/*
+ * Do we have a pending number at the end, or when
+ * we see a new one? Let's assume it's a month day,
+ * as in "Dec 6, 1992"
+ */
+static void pending_number(struct tm *tm, int *num)
+{
+	int number = *num;
+
+	if (number) {
+		*num = 0;
+		if (tm->tm_mday < 0 && number < 32)
+			tm->tm_mday = number;
+		else if (tm->tm_mon < 0 && number < 13)
+			tm->tm_mon = number-1;
+		else if (tm->tm_year < 0) {
+			if (number > 1969 && number < 2100)
+				tm->tm_year = number - 1900;
+			else if (number > 69 && number < 100)
+				tm->tm_year = number;
+			else if (number < 38)
+				tm->tm_year = 100 + number;
+			/* We mess up for number = 00 ? */
+		}
+	}
+}
+
+static git_time_t approxidate_str(const char *date,
+	time_t time_sec,
+	int *error_ret)
+{
+	int number = 0;
+	int touched = 0;
+	struct tm tm = {0}, now;
+
+	p_localtime_r(&time_sec, &tm);
+	now = tm;
+
+	tm.tm_year = -1;
+	tm.tm_mon = -1;
+	tm.tm_mday = -1;
+
+	for (;;) {
+		unsigned char c = *date;
+		if (!c)
+			break;
+		date++;
+		if (isdigit(c)) {
+			pending_number(&tm, &number);
+			date = approxidate_digit(date-1, &tm, &number);
+			touched = 1;
+			continue;
+		}
+		if (isalpha(c))
+			date = approxidate_alpha(date-1, &tm, &now, &number, &touched);
+	}
+	pending_number(&tm, &number);
+	if (!touched)
+		*error_ret = 1;
+	return update_tm(&tm, &now, 0);
+}
+
+int git__date_parse(git_time_t *out, const char *date)
+{
+	time_t time_sec;
+	git_time_t timestamp;
+	int offset, error_ret=0;
+
+	if (!parse_date_basic(date, &timestamp, &offset)) {
+		*out = timestamp;
+		return 0;
+	}
+
+	if (time(&time_sec) == -1)
+		return -1;
+
+	*out = approxidate_str(date, time_sec, &error_ret);
+   return error_ret;
+}
+
+int git__date_rfc2822_fmt(char *out, size_t len, const git_time *date)
+{
+	int written;
+	struct tm gmt;
+	time_t t;
+
+	assert(out && date);
+
+	t = (time_t) (date->time + date->offset * 60);
+
+	if (p_gmtime_r (&t, &gmt) == NULL)
+		return -1;
+
+	written = p_snprintf(out, len, "%.3s, %u %.3s %.4u %02u:%02u:%02u %+03d%02d",
+		weekday_names[gmt.tm_wday],
+		gmt.tm_mday,
+		month_names[gmt.tm_mon],
+		gmt.tm_year + 1900,
+		gmt.tm_hour, gmt.tm_min, gmt.tm_sec,
+		date->offset / 60, date->offset % 60);
+
+	if (written < 0 || (written > (int) len - 1))
+		return -1;
+
+	return 0;
+}
+

vendor/libgit2-sys/libgit2/src/delta.c

diff --git a/vendor/libgit2-sys/libgit2/src/delta.c b/vendor/libgit2-sys/libgit2/src/delta.c
new file mode 100644
index 0000000..073cba7
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/delta.c
@@ -0,0 +1,619 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "delta.h"
+
+/* maximum hash entry list for the same hash bucket */
+#define HASH_LIMIT 64
+
+#define RABIN_SHIFT 23
+#define RABIN_WINDOW 16
+
+static const unsigned int T[256] = {
+	0x00000000, 0xab59b4d1, 0x56b369a2, 0xfdeadd73, 0x063f6795, 0xad66d344,
+	0x508c0e37, 0xfbd5bae6, 0x0c7ecf2a, 0xa7277bfb, 0x5acda688, 0xf1941259,
+	0x0a41a8bf, 0xa1181c6e, 0x5cf2c11d, 0xf7ab75cc, 0x18fd9e54, 0xb3a42a85,
+	0x4e4ef7f6, 0xe5174327, 0x1ec2f9c1, 0xb59b4d10, 0x48719063, 0xe32824b2,
+	0x1483517e, 0xbfdae5af, 0x423038dc, 0xe9698c0d, 0x12bc36eb, 0xb9e5823a,
+	0x440f5f49, 0xef56eb98, 0x31fb3ca8, 0x9aa28879, 0x6748550a, 0xcc11e1db,
+	0x37c45b3d, 0x9c9defec, 0x6177329f, 0xca2e864e, 0x3d85f382, 0x96dc4753,
+	0x6b369a20, 0xc06f2ef1, 0x3bba9417, 0x90e320c6, 0x6d09fdb5, 0xc6504964,
+	0x2906a2fc, 0x825f162d, 0x7fb5cb5e, 0xd4ec7f8f, 0x2f39c569, 0x846071b8,
+	0x798aaccb, 0xd2d3181a, 0x25786dd6, 0x8e21d907, 0x73cb0474, 0xd892b0a5,
+	0x23470a43, 0x881ebe92, 0x75f463e1, 0xdeadd730, 0x63f67950, 0xc8afcd81,
+	0x354510f2, 0x9e1ca423, 0x65c91ec5, 0xce90aa14, 0x337a7767, 0x9823c3b6,
+	0x6f88b67a, 0xc4d102ab, 0x393bdfd8, 0x92626b09, 0x69b7d1ef, 0xc2ee653e,
+	0x3f04b84d, 0x945d0c9c, 0x7b0be704, 0xd05253d5, 0x2db88ea6, 0x86e13a77,
+	0x7d348091, 0xd66d3440, 0x2b87e933, 0x80de5de2, 0x7775282e, 0xdc2c9cff,
+	0x21c6418c, 0x8a9ff55d, 0x714a4fbb, 0xda13fb6a, 0x27f92619, 0x8ca092c8,
+	0x520d45f8, 0xf954f129, 0x04be2c5a, 0xafe7988b, 0x5432226d, 0xff6b96bc,
+	0x02814bcf, 0xa9d8ff1e, 0x5e738ad2, 0xf52a3e03, 0x08c0e370, 0xa39957a1,
+	0x584ced47, 0xf3155996, 0x0eff84e5, 0xa5a63034, 0x4af0dbac, 0xe1a96f7d,
+	0x1c43b20e, 0xb71a06df, 0x4ccfbc39, 0xe79608e8, 0x1a7cd59b, 0xb125614a,
+	0x468e1486, 0xedd7a057, 0x103d7d24, 0xbb64c9f5, 0x40b17313, 0xebe8c7c2,
+	0x16021ab1, 0xbd5bae60, 0x6cb54671, 0xc7ecf2a0, 0x3a062fd3, 0x915f9b02,
+	0x6a8a21e4, 0xc1d39535, 0x3c394846, 0x9760fc97, 0x60cb895b, 0xcb923d8a,
+	0x3678e0f9, 0x9d215428, 0x66f4eece, 0xcdad5a1f, 0x3047876c, 0x9b1e33bd,
+	0x7448d825, 0xdf116cf4, 0x22fbb187, 0x89a20556, 0x7277bfb0, 0xd92e0b61,
+	0x24c4d612, 0x8f9d62c3, 0x7836170f, 0xd36fa3de, 0x2e857ead, 0x85dcca7c,
+	0x7e09709a, 0xd550c44b, 0x28ba1938, 0x83e3ade9, 0x5d4e7ad9, 0xf617ce08,
+	0x0bfd137b, 0xa0a4a7aa, 0x5b711d4c, 0xf028a99d, 0x0dc274ee, 0xa69bc03f,
+	0x5130b5f3, 0xfa690122, 0x0783dc51, 0xacda6880, 0x570fd266, 0xfc5666b7,
+	0x01bcbbc4, 0xaae50f15, 0x45b3e48d, 0xeeea505c, 0x13008d2f, 0xb85939fe,
+	0x438c8318, 0xe8d537c9, 0x153feaba, 0xbe665e6b, 0x49cd2ba7, 0xe2949f76,
+	0x1f7e4205, 0xb427f6d4, 0x4ff24c32, 0xe4abf8e3, 0x19412590, 0xb2189141,
+	0x0f433f21, 0xa41a8bf0, 0x59f05683, 0xf2a9e252, 0x097c58b4, 0xa225ec65,
+	0x5fcf3116, 0xf49685c7, 0x033df00b, 0xa86444da, 0x558e99a9, 0xfed72d78,
+	0x0502979e, 0xae5b234f, 0x53b1fe3c, 0xf8e84aed, 0x17bea175, 0xbce715a4,
+	0x410dc8d7, 0xea547c06, 0x1181c6e0, 0xbad87231, 0x4732af42, 0xec6b1b93,
+	0x1bc06e5f, 0xb099da8e, 0x4d7307fd, 0xe62ab32c, 0x1dff09ca, 0xb6a6bd1b,
+	0x4b4c6068, 0xe015d4b9, 0x3eb80389, 0x95e1b758, 0x680b6a2b, 0xc352defa,
+	0x3887641c, 0x93ded0cd, 0x6e340dbe, 0xc56db96f, 0x32c6cca3, 0x999f7872,
+	0x6475a501, 0xcf2c11d0, 0x34f9ab36, 0x9fa01fe7, 0x624ac294, 0xc9137645,
+	0x26459ddd, 0x8d1c290c, 0x70f6f47f, 0xdbaf40ae, 0x207afa48, 0x8b234e99,
+	0x76c993ea, 0xdd90273b, 0x2a3b52f7, 0x8162e626, 0x7c883b55, 0xd7d18f84,
+	0x2c043562, 0x875d81b3, 0x7ab75cc0, 0xd1eee811
+};
+
+static const unsigned int U[256] = {
+	0x00000000, 0x7eb5200d, 0x5633f4cb, 0x2886d4c6, 0x073e5d47, 0x798b7d4a,
+	0x510da98c, 0x2fb88981, 0x0e7cba8e, 0x70c99a83, 0x584f4e45, 0x26fa6e48,
+	0x0942e7c9, 0x77f7c7c4, 0x5f711302, 0x21c4330f, 0x1cf9751c, 0x624c5511,
+	0x4aca81d7, 0x347fa1da, 0x1bc7285b, 0x65720856, 0x4df4dc90, 0x3341fc9d,
+	0x1285cf92, 0x6c30ef9f, 0x44b63b59, 0x3a031b54, 0x15bb92d5, 0x6b0eb2d8,
+	0x4388661e, 0x3d3d4613, 0x39f2ea38, 0x4747ca35, 0x6fc11ef3, 0x11743efe,
+	0x3eccb77f, 0x40799772, 0x68ff43b4, 0x164a63b9, 0x378e50b6, 0x493b70bb,
+	0x61bda47d, 0x1f088470, 0x30b00df1, 0x4e052dfc, 0x6683f93a, 0x1836d937,
+	0x250b9f24, 0x5bbebf29, 0x73386bef, 0x0d8d4be2, 0x2235c263, 0x5c80e26e,
+	0x740636a8, 0x0ab316a5, 0x2b7725aa, 0x55c205a7, 0x7d44d161, 0x03f1f16c,
+	0x2c4978ed, 0x52fc58e0, 0x7a7a8c26, 0x04cfac2b, 0x73e5d470, 0x0d50f47d,
+	0x25d620bb, 0x5b6300b6, 0x74db8937, 0x0a6ea93a, 0x22e87dfc, 0x5c5d5df1,
+	0x7d996efe, 0x032c4ef3, 0x2baa9a35, 0x551fba38, 0x7aa733b9, 0x041213b4,
+	0x2c94c772, 0x5221e77f, 0x6f1ca16c, 0x11a98161, 0x392f55a7, 0x479a75aa,
+	0x6822fc2b, 0x1697dc26, 0x3e1108e0, 0x40a428ed, 0x61601be2, 0x1fd53bef,
+	0x3753ef29, 0x49e6cf24, 0x665e46a5, 0x18eb66a8, 0x306db26e, 0x4ed89263,
+	0x4a173e48, 0x34a21e45, 0x1c24ca83, 0x6291ea8e, 0x4d29630f, 0x339c4302,
+	0x1b1a97c4, 0x65afb7c9, 0x446b84c6, 0x3adea4cb, 0x1258700d, 0x6ced5000,
+	0x4355d981, 0x3de0f98c, 0x15662d4a, 0x6bd30d47, 0x56ee4b54, 0x285b6b59,
+	0x00ddbf9f, 0x7e689f92, 0x51d01613, 0x2f65361e, 0x07e3e2d8, 0x7956c2d5,
+	0x5892f1da, 0x2627d1d7, 0x0ea10511, 0x7014251c, 0x5facac9d, 0x21198c90,
+	0x099f5856, 0x772a785b, 0x4c921c31, 0x32273c3c, 0x1aa1e8fa, 0x6414c8f7,
+	0x4bac4176, 0x3519617b, 0x1d9fb5bd, 0x632a95b0, 0x42eea6bf, 0x3c5b86b2,
+	0x14dd5274, 0x6a687279, 0x45d0fbf8, 0x3b65dbf5, 0x13e30f33, 0x6d562f3e,
+	0x506b692d, 0x2ede4920, 0x06589de6, 0x78edbdeb, 0x5755346a, 0x29e01467,
+	0x0166c0a1, 0x7fd3e0ac, 0x5e17d3a3, 0x20a2f3ae, 0x08242768, 0x76910765,
+	0x59298ee4, 0x279caee9, 0x0f1a7a2f, 0x71af5a22, 0x7560f609, 0x0bd5d604,
+	0x235302c2, 0x5de622cf, 0x725eab4e, 0x0ceb8b43, 0x246d5f85, 0x5ad87f88,
+	0x7b1c4c87, 0x05a96c8a, 0x2d2fb84c, 0x539a9841, 0x7c2211c0, 0x029731cd,
+	0x2a11e50b, 0x54a4c506, 0x69998315, 0x172ca318, 0x3faa77de, 0x411f57d3,
+	0x6ea7de52, 0x1012fe5f, 0x38942a99, 0x46210a94, 0x67e5399b, 0x19501996,
+	0x31d6cd50, 0x4f63ed5d, 0x60db64dc, 0x1e6e44d1, 0x36e89017, 0x485db01a,
+	0x3f77c841, 0x41c2e84c, 0x69443c8a, 0x17f11c87, 0x38499506, 0x46fcb50b,
+	0x6e7a61cd, 0x10cf41c0, 0x310b72cf, 0x4fbe52c2, 0x67388604, 0x198da609,
+	0x36352f88, 0x48800f85, 0x6006db43, 0x1eb3fb4e, 0x238ebd5d, 0x5d3b9d50,
+	0x75bd4996, 0x0b08699b, 0x24b0e01a, 0x5a05c017, 0x728314d1, 0x0c3634dc,
+	0x2df207d3, 0x534727de, 0x7bc1f318, 0x0574d315, 0x2acc5a94, 0x54797a99,
+	0x7cffae5f, 0x024a8e52, 0x06852279, 0x78300274, 0x50b6d6b2, 0x2e03f6bf,
+	0x01bb7f3e, 0x7f0e5f33, 0x57888bf5, 0x293dabf8, 0x08f998f7, 0x764cb8fa,
+	0x5eca6c3c, 0x207f4c31, 0x0fc7c5b0, 0x7172e5bd, 0x59f4317b, 0x27411176,
+	0x1a7c5765, 0x64c97768, 0x4c4fa3ae, 0x32fa83a3, 0x1d420a22, 0x63f72a2f,
+	0x4b71fee9, 0x35c4dee4, 0x1400edeb, 0x6ab5cde6, 0x42331920, 0x3c86392d,
+	0x133eb0ac, 0x6d8b90a1, 0x450d4467, 0x3bb8646a
+};
+
+struct index_entry {
+	const unsigned char *ptr;
+	unsigned int val;
+	struct index_entry *next;
+};
+
+struct git_delta_index {
+	unsigned long memsize;
+	const void *src_buf;
+	size_t src_size;
+	unsigned int hash_mask;
+	struct index_entry *hash[GIT_FLEX_ARRAY];
+};
+
+static int lookup_index_alloc(
+	void **out, unsigned long *out_len, size_t entries, size_t hash_count)
+{
+	size_t entries_len, hash_len, index_len;
+
+	GITERR_CHECK_ALLOC_MULTIPLY(&entries_len, entries, sizeof(struct index_entry));
+	GITERR_CHECK_ALLOC_MULTIPLY(&hash_len, hash_count, sizeof(struct index_entry *));
+
+	GITERR_CHECK_ALLOC_ADD(&index_len, sizeof(struct git_delta_index), entries_len);
+	GITERR_CHECK_ALLOC_ADD(&index_len, index_len, hash_len);
+
+	if (!git__is_ulong(index_len)) {
+		giterr_set(GITERR_NOMEMORY, "overly large delta");
+		return -1;
+	}
+
+	*out = git__malloc(index_len);
+	GITERR_CHECK_ALLOC(*out);
+
+	*out_len = index_len;
+	return 0;
+}
+
+int git_delta_index_init(
+	git_delta_index **out, const void *buf, size_t bufsize)
+{
+	unsigned int i, hsize, hmask, entries, prev_val, *hash_count;
+	const unsigned char *data, *buffer = buf;
+	struct git_delta_index *index;
+	struct index_entry *entry, **hash;
+	void *mem;
+	unsigned long memsize;
+
+	*out = NULL;
+
+	if (!buf || !bufsize)
+		return 0;
+
+	/* Determine index hash size.  Note that indexing skips the
+	   first byte to allow for optimizing the rabin polynomial
+	   initialization in create_delta(). */
+	entries = (unsigned int)(bufsize - 1) / RABIN_WINDOW;
+	if (bufsize >= 0xffffffffUL) {
+		/*
+		 * Current delta format can't encode offsets into
+		 * reference buffer with more than 32 bits.
+		 */
+		entries = 0xfffffffeU / RABIN_WINDOW;
+	}
+	hsize = entries / 4;
+	for (i = 4; i < 31 && (1u << i) < hsize; i++);
+	hsize = 1 << i;
+	hmask = hsize - 1;
+
+	if (lookup_index_alloc(&mem, &memsize, entries, hsize) < 0)
+		return -1;
+
+	index = mem;
+	mem = index->hash;
+	hash = mem;
+	mem = hash + hsize;
+	entry = mem;
+
+	index->memsize = memsize;
+	index->src_buf = buf;
+	index->src_size = bufsize;
+	index->hash_mask = hmask;
+	memset(hash, 0, hsize * sizeof(*hash));
+
+	/* allocate an array to count hash entries */
+	hash_count = git__calloc(hsize, sizeof(*hash_count));
+	if (!hash_count) {
+		git__free(index);
+		return -1;
+	}
+
+	/* then populate the index */
+	prev_val = ~0;
+	for (data = buffer + entries * RABIN_WINDOW - RABIN_WINDOW;
+	     data >= buffer;
+	     data -= RABIN_WINDOW) {
+		unsigned int val = 0;
+		for (i = 1; i <= RABIN_WINDOW; i++)
+			val = ((val << 8) | data[i]) ^ T[val >> RABIN_SHIFT];
+		if (val == prev_val) {
+			/* keep the lowest of consecutive identical blocks */
+			entry[-1].ptr = data + RABIN_WINDOW;
+		} else {
+			prev_val = val;
+			i = val & hmask;
+			entry->ptr = data + RABIN_WINDOW;
+			entry->val = val;
+			entry->next = hash[i];
+			hash[i] = entry++;
+			hash_count[i]++;
+		}
+	}
+
+	/*
+	 * Determine a limit on the number of entries in the same hash
+	 * bucket.  This guard us against patological data sets causing
+	 * really bad hash distribution with most entries in the same hash
+	 * bucket that would bring us to O(m*n) computing costs (m and n
+	 * corresponding to reference and target buffer sizes).
+	 *
+	 * Make sure none of the hash buckets has more entries than
+	 * we're willing to test.  Otherwise we cull the entry list
+	 * uniformly to still preserve a good repartition across
+	 * the reference buffer.
+	 */
+	for (i = 0; i < hsize; i++) {
+		if (hash_count[i] < HASH_LIMIT)
+			continue;
+
+		entry = hash[i];
+		do {
+			struct index_entry *keep = entry;
+			int skip = hash_count[i] / HASH_LIMIT / 2;
+			do {
+				entry = entry->next;
+			} while(--skip && entry);
+			keep->next = entry;
+		} while (entry);
+	}
+	git__free(hash_count);
+
+	*out = index;
+	return 0;
+}
+
+void git_delta_index_free(git_delta_index *index)
+{
+	git__free(index);
+}
+
+size_t git_delta_index_size(git_delta_index *index)
+{
+	assert(index);
+
+	return index->memsize;
+}
+
+/*
+ * The maximum size for any opcode sequence, including the initial header
+ * plus rabin window plus biggest copy.
+ */
+#define MAX_OP_SIZE	(5 + 5 + 1 + RABIN_WINDOW + 7)
+
+int git_delta_create_from_index(
+	void **out,
+	size_t *out_len,
+	const struct git_delta_index *index,
+	const void *trg_buf,
+	size_t trg_size,
+	size_t max_size)
+{
+	unsigned int i, bufpos, bufsize, moff, msize, val;
+	int inscnt;
+	const unsigned char *ref_data, *ref_top, *data, *top;
+	unsigned char *buf;
+
+	*out = NULL;
+	*out_len = 0;
+
+	if (!trg_buf || !trg_size)
+		return 0;
+
+	bufpos = 0;
+	bufsize = 8192;
+	if (max_size && bufsize >= max_size)
+		bufsize = (unsigned int)(max_size + MAX_OP_SIZE + 1);
+	buf = git__malloc(bufsize);
+	GITERR_CHECK_ALLOC(buf);
+
+	/* store reference buffer size */
+	i = index->src_size;
+	while (i >= 0x80) {
+		buf[bufpos++] = i | 0x80;
+		i >>= 7;
+	}
+	buf[bufpos++] = i;
+
+	/* store target buffer size */
+	i = trg_size;
+	while (i >= 0x80) {
+		buf[bufpos++] = i | 0x80;
+		i >>= 7;
+	}
+	buf[bufpos++] = i;
+
+	ref_data = index->src_buf;
+	ref_top = ref_data + index->src_size;
+	data = trg_buf;
+	top = (const unsigned char *) trg_buf + trg_size;
+
+	bufpos++;
+	val = 0;
+	for (i = 0; i < RABIN_WINDOW && data < top; i++, data++) {
+		buf[bufpos++] = *data;
+		val = ((val << 8) | *data) ^ T[val >> RABIN_SHIFT];
+	}
+	inscnt = i;
+
+	moff = 0;
+	msize = 0;
+	while (data < top) {
+		if (msize < 4096) {
+			struct index_entry *entry;
+			val ^= U[data[-RABIN_WINDOW]];
+			val = ((val << 8) | *data) ^ T[val >> RABIN_SHIFT];
+			i = val & index->hash_mask;
+			for (entry = index->hash[i]; entry; entry = entry->next) {
+				const unsigned char *ref = entry->ptr;
+				const unsigned char *src = data;
+				unsigned int ref_size = (unsigned int)(ref_top - ref);
+				if (entry->val != val)
+					continue;
+				if (ref_size > (unsigned int)(top - src))
+					ref_size = (unsigned int)(top - src);
+				if (ref_size <= msize)
+					break;
+				while (ref_size-- && *src++ == *ref)
+					ref++;
+				if (msize < (unsigned int)(ref - entry->ptr)) {
+					/* this is our best match so far */
+					msize = (unsigned int)(ref - entry->ptr);
+					moff = (unsigned int)(entry->ptr - ref_data);
+					if (msize >= 4096) /* good enough */
+						break;
+				}
+			}
+		}
+
+		if (msize < 4) {
+			if (!inscnt)
+				bufpos++;
+			buf[bufpos++] = *data++;
+			inscnt++;
+			if (inscnt == 0x7f) {
+				buf[bufpos - inscnt - 1] = inscnt;
+				inscnt = 0;
+			}
+			msize = 0;
+		} else {
+			unsigned int left;
+			unsigned char *op;
+
+			if (inscnt) {
+				while (moff && ref_data[moff-1] == data[-1]) {
+					/* we can match one byte back */
+					msize++;
+					moff--;
+					data--;
+					bufpos--;
+					if (--inscnt)
+						continue;
+					bufpos--;  /* remove count slot */
+					inscnt--;  /* make it -1 */
+					break;
+				}
+				buf[bufpos - inscnt - 1] = inscnt;
+				inscnt = 0;
+			}
+
+			/* A copy op is currently limited to 64KB (pack v2) */
+			left = (msize < 0x10000) ? 0 : (msize - 0x10000);
+			msize -= left;
+
+			op = buf + bufpos++;
+			i = 0x80;
+
+			if (moff & 0x000000ff)
+				buf[bufpos++] = moff >> 0,  i |= 0x01;
+			if (moff & 0x0000ff00)
+				buf[bufpos++] = moff >> 8,  i |= 0x02;
+			if (moff & 0x00ff0000)
+				buf[bufpos++] = moff >> 16, i |= 0x04;
+			if (moff & 0xff000000)
+				buf[bufpos++] = moff >> 24, i |= 0x08;
+
+			if (msize & 0x00ff)
+				buf[bufpos++] = msize >> 0, i |= 0x10;
+			if (msize & 0xff00)
+				buf[bufpos++] = msize >> 8, i |= 0x20;
+
+			*op = i;
+
+			data += msize;
+			moff += msize;
+			msize = left;
+
+			if (msize < 4096) {
+				int j;
+				val = 0;
+				for (j = -RABIN_WINDOW; j < 0; j++)
+					val = ((val << 8) | data[j])
+					      ^ T[val >> RABIN_SHIFT];
+			}
+		}
+
+		if (bufpos >= bufsize - MAX_OP_SIZE) {
+			void *tmp = buf;
+			bufsize = bufsize * 3 / 2;
+			if (max_size && bufsize >= max_size)
+				bufsize = max_size + MAX_OP_SIZE + 1;
+			if (max_size && bufpos > max_size)
+				break;
+			buf = git__realloc(buf, bufsize);
+			if (!buf) {
+				git__free(tmp);
+				return -1;
+			}
+		}
+	}
+
+	if (inscnt)
+		buf[bufpos - inscnt - 1] = inscnt;
+
+	if (max_size && bufpos > max_size) {
+		giterr_set(GITERR_NOMEMORY, "delta would be larger than maximum size");
+		git__free(buf);
+		return GIT_EBUFS;
+	}
+
+	*out_len = bufpos;
+	*out = buf;
+	return 0;
+}
+
+/*
+* Delta application was heavily cribbed from BinaryDelta.java in JGit, which
+* itself was heavily cribbed from <code>patch-delta.c</code> in the
+* GIT project.	The original delta patching code was written by
+* Nicolas Pitre <nico@cam.org>.
+*/
+
+static int hdr_sz(
+	size_t *size,
+	const unsigned char **delta,
+	const unsigned char *end)
+{
+	const unsigned char *d = *delta;
+	size_t r = 0;
+	unsigned int c, shift = 0;
+
+	do {
+		if (d == end) {
+			giterr_set(GITERR_INVALID, "truncated delta");
+			return -1;
+		}
+
+		c = *d++;
+		r |= (c & 0x7f) << shift;
+		shift += 7;
+	} while (c & 0x80);
+	*delta = d;
+	*size = r;
+	return 0;
+}
+
+int git_delta_read_header(
+	size_t *base_out,
+	size_t *result_out,
+	const unsigned char *delta,
+	size_t delta_len)
+{
+	const unsigned char *delta_end = delta + delta_len;
+	if ((hdr_sz(base_out, &delta, delta_end) < 0) ||
+		(hdr_sz(result_out, &delta, delta_end) < 0))
+		return -1;
+	return 0;
+}
+
+#define DELTA_HEADER_BUFFER_LEN 16
+int git_delta_read_header_fromstream(
+	size_t *base_sz, size_t *res_sz, git_packfile_stream *stream)
+{
+	static const size_t buffer_len = DELTA_HEADER_BUFFER_LEN;
+	unsigned char buffer[DELTA_HEADER_BUFFER_LEN];
+	const unsigned char *delta, *delta_end;
+	size_t len;
+	ssize_t read;
+
+	len = read = 0;
+	while (len < buffer_len) {
+		read = git_packfile_stream_read(stream, &buffer[len], buffer_len - len);
+
+		if (read == 0)
+			break;
+
+		if (read == GIT_EBUFS)
+			continue;
+
+		len += read;
+	}
+
+	delta = buffer;
+	delta_end = delta + len;
+	if ((hdr_sz(base_sz, &delta, delta_end) < 0) ||
+		(hdr_sz(res_sz, &delta, delta_end) < 0))
+		return -1;
+
+	return 0;
+}
+
+int git_delta_apply(
+	void **out,
+	size_t *out_len,
+	const unsigned char *base,
+	size_t base_len,
+	const unsigned char *delta,
+	size_t delta_len)
+{
+	const unsigned char *delta_end = delta + delta_len;
+	size_t base_sz, res_sz, alloc_sz;
+	unsigned char *res_dp;
+
+	*out = NULL;
+	*out_len = 0;
+
+	/* Check that the base size matches the data we were given;
+	* if not we would underflow while accessing data from the
+	* base object, resulting in data corruption or segfault.
+	*/
+	if ((hdr_sz(&base_sz, &delta, delta_end) < 0) || (base_sz != base_len)) {
+		giterr_set(GITERR_INVALID, "failed to apply delta: base size does not match given data");
+		return -1;
+	}
+
+	if (hdr_sz(&res_sz, &delta, delta_end) < 0) {
+		giterr_set(GITERR_INVALID, "failed to apply delta: base size does not match given data");
+		return -1;
+	}
+
+	GITERR_CHECK_ALLOC_ADD(&alloc_sz, res_sz, 1);
+	res_dp = git__malloc(alloc_sz);
+	GITERR_CHECK_ALLOC(res_dp);
+
+	res_dp[res_sz] = '\0';
+	*out = res_dp;
+	*out_len = res_sz;
+
+	while (delta < delta_end) {
+		unsigned char cmd = *delta++;
+		if (cmd & 0x80) {
+			/* cmd is a copy instruction; copy from the base.
+			*/
+			size_t off = 0, len = 0;
+
+			if (cmd & 0x01) off = *delta++;
+			if (cmd & 0x02) off |= *delta++ << 8UL;
+			if (cmd & 0x04) off |= *delta++ << 16UL;
+			if (cmd & 0x08) off |= *delta++ << 24UL;
+
+			if (cmd & 0x10) len = *delta++;
+			if (cmd & 0x20) len |= *delta++ << 8UL;
+			if (cmd & 0x40) len |= *delta++ << 16UL;
+			if (!len)		len = 0x10000;
+
+			if (base_len < off + len || res_sz < len)
+				goto fail;
+			memcpy(res_dp, base + off, len);
+			res_dp += len;
+			res_sz -= len;
+
+		}
+		else if (cmd) {
+			/* cmd is a literal insert instruction; copy from
+			* the delta stream itself.
+			*/
+			if (delta_end - delta < cmd || res_sz < cmd)
+				goto fail;
+			memcpy(res_dp, delta, cmd);
+			delta += cmd;
+			res_dp += cmd;
+			res_sz -= cmd;
+
+		}
+		else {
+			/* cmd == 0 is reserved for future encodings.
+			*/
+			goto fail;
+		}
+	}
+
+	if (delta != delta_end || res_sz)
+		goto fail;
+	return 0;
+
+fail:
+	git__free(*out);
+
+	*out = NULL;
+	*out_len = 0;
+
+	giterr_set(GITERR_INVALID, "failed to apply delta");
+	return -1;
+}

vendor/libgit2-sys/libgit2/src/delta.h

diff --git a/vendor/libgit2-sys/libgit2/src/delta.h b/vendor/libgit2-sys/libgit2/src/delta.h
new file mode 100644
index 0000000..f619873
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/delta.h
@@ -0,0 +1,136 @@
+/*
+ * diff-delta code taken from git.git. See diff-delta.c for details.
+ *
+ */
+#ifndef INCLUDE_git_delta_h__
+#define INCLUDE_git_delta_h__
+
+#include "common.h"
+
+#include "pack.h"
+
+typedef struct git_delta_index git_delta_index;
+
+/*
+ * git_delta_index_init: compute index data from given buffer
+ *
+ * This returns a pointer to a struct delta_index that should be passed to
+ * subsequent create_delta() calls, or to free_delta_index().  A NULL pointer
+ * is returned on failure.  The given buffer must not be freed nor altered
+ * before free_delta_index() is called.  The returned pointer must be freed
+ * using free_delta_index().
+ */
+extern int git_delta_index_init(
+	git_delta_index **out, const void *buf, size_t bufsize);
+
+/*
+ * Free the index created by git_delta_index_init()
+ */
+extern void git_delta_index_free(git_delta_index *index);
+
+/*
+ * Returns memory usage of delta index.
+ */
+extern size_t git_delta_index_size(git_delta_index *index);
+
+/*
+ * create_delta: create a delta from given index for the given buffer
+ *
+ * This function may be called multiple times with different buffers using
+ * the same delta_index pointer.  If max_delta_size is non-zero and the
+ * resulting delta is to be larger than max_delta_size then NULL is returned.
+ * On success, a non-NULL pointer to the buffer with the delta data is
+ * returned and *delta_size is updated with its size.  The returned buffer
+ * must be freed by the caller.
+ */
+extern int git_delta_create_from_index(
+	void **out,
+	size_t *out_size,
+	const struct git_delta_index *index,
+	const void *buf,
+	size_t bufsize,
+	size_t max_delta_size);
+
+/*
+ * diff_delta: create a delta from source buffer to target buffer
+ *
+ * If max_delta_size is non-zero and the resulting delta is to be larger
+ * than max_delta_size then GIT_EBUFS is returned.  On success, a non-NULL
+ * pointer to the buffer with the delta data is returned and *delta_size is
+ * updated with its size.  The returned buffer must be freed by the caller.
+ */
+GIT_INLINE(int) git_delta(
+	void **out, size_t *out_len,
+	const void *src_buf, size_t src_bufsize,
+	const void *trg_buf, size_t trg_bufsize,
+	size_t max_delta_size)
+{
+	git_delta_index *index;
+	int error = 0;
+
+	*out = NULL;
+	*out_len = 0;
+
+	if ((error = git_delta_index_init(&index, src_buf, src_bufsize)) < 0)
+		return error;
+
+	if (index) {
+		error = git_delta_create_from_index(out, out_len,
+			index, trg_buf, trg_bufsize, max_delta_size);
+
+		git_delta_index_free(index);
+	}
+
+	return error;
+}
+
+/* the smallest possible delta size is 4 bytes */
+#define GIT_DELTA_SIZE_MIN	4
+
+/**
+* Apply a git binary delta to recover the original content.
+* The caller is responsible for freeing the returned buffer.
+*
+* @param out the output buffer
+* @param out_len the length of the output buffer
+* @param base the base to copy from during copy instructions.
+* @param base_len number of bytes available at base.
+* @param delta the delta to execute copy/insert instructions from.
+* @param delta_len total number of bytes in the delta.
+* @return 0 on success or an error code
+*/
+extern int git_delta_apply(
+	void **out,
+	size_t *out_len,
+	const unsigned char *base,
+	size_t base_len,
+	const unsigned char *delta,
+	size_t delta_len);
+
+/**
+* Read the header of a git binary delta.
+*
+* @param base_out pointer to store the base size field.
+* @param result_out pointer to store the result size field.
+* @param delta the delta to execute copy/insert instructions from.
+* @param delta_len total number of bytes in the delta.
+* @return 0 on success or an error code
+*/
+extern int git_delta_read_header(
+	size_t *base_out,
+	size_t *result_out,
+	const unsigned char *delta,
+	size_t delta_len);
+
+/**
+ * Read the header of a git binary delta
+ *
+ * This variant reads just enough from the packfile stream to read the
+ * delta header.
+ */
+extern int git_delta_read_header_fromstream(
+	size_t *base_out,
+	size_t *result_out,
+	git_packfile_stream *stream);
+
+#endif

vendor/libgit2-sys/libgit2/src/describe.c

diff --git a/vendor/libgit2-sys/libgit2/src/describe.c b/vendor/libgit2-sys/libgit2/src/describe.c
new file mode 100644
index 0000000..edf8edf
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/describe.c
@@ -0,0 +1,893 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "git2/describe.h"
+#include "git2/strarray.h"
+#include "git2/diff.h"
+#include "git2/status.h"
+
+#include "commit.h"
+#include "commit_list.h"
+#include "oidmap.h"
+#include "refs.h"
+#include "revwalk.h"
+#include "tag.h"
+#include "vector.h"
+#include "repository.h"
+
+/* Ported from https://github.com/git/git/blob/89dde7882f71f846ccd0359756d27bebc31108de/builtin/describe.c */
+
+struct commit_name {
+	git_tag *tag;
+	unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
+	unsigned name_checked:1;
+	git_oid sha1;
+	char *path;
+
+	/* Khash workaround. They original key has to still be reachable */
+	git_oid peeled;
+};
+
+static void *oidmap_value_bykey(git_oidmap *map, const git_oid *key)
+{
+	khint_t pos = git_oidmap_lookup_index(map, key);
+
+	if (!git_oidmap_valid_index(map, pos))
+		return NULL;
+
+	return git_oidmap_value_at(map, pos);
+}
+
+static struct commit_name *find_commit_name(
+	git_oidmap *names,
+	const git_oid *peeled)
+{
+	return (struct commit_name *)(oidmap_value_bykey(names, peeled));
+}
+
+static int replace_name(
+	git_tag **tag,
+	git_repository *repo,
+	struct commit_name *e,
+	unsigned int prio,
+	const git_oid *sha1)
+{
+	git_time_t e_time = 0, t_time = 0;
+
+	if (!e || e->prio < prio)
+		return 1;
+
+	if (e->prio == 2 && prio == 2) {
+		/* Multiple annotated tags point to the same commit.
+		 * Select one to keep based upon their tagger date.
+		 */
+		git_tag *t = NULL;
+
+		if (!e->tag) {
+			if (git_tag_lookup(&t, repo, &e->sha1) < 0)
+				return 1;
+			e->tag = t;
+		}
+
+		if (git_tag_lookup(&t, repo, sha1) < 0)
+			return 0;
+
+		*tag = t;
+
+		if (e->tag->tagger)
+			e_time = e->tag->tagger->when.time;
+
+		if (t->tagger)
+			t_time = t->tagger->when.time;
+
+		if (e_time < t_time)
+			return 1;
+	}
+
+	return 0;
+}
+
+static int add_to_known_names(
+	git_repository *repo,
+	git_oidmap *names,
+	const char *path,
+	const git_oid *peeled,
+	unsigned int prio,
+	const git_oid *sha1)
+{
+	struct commit_name *e = find_commit_name(names, peeled);
+	bool found = (e != NULL);
+
+	git_tag *tag = NULL;
+	if (replace_name(&tag, repo, e, prio, sha1)) {
+		if (!found) {
+			e = git__malloc(sizeof(struct commit_name));
+			GITERR_CHECK_ALLOC(e);
+
+			e->path = NULL;
+			e->tag = NULL;
+		}
+
+		if (e->tag)
+			git_tag_free(e->tag);
+		e->tag = tag;
+		e->prio = prio;
+		e->name_checked = 0;
+		git_oid_cpy(&e->sha1, sha1);
+		git__free(e->path);
+		e->path = git__strdup(path);
+		git_oid_cpy(&e->peeled, peeled);
+
+		if (!found) {
+			int ret;
+
+			git_oidmap_insert(names, &e->peeled, e, &ret);
+			if (ret < 0)
+				return -1;
+		}
+	}
+	else
+		git_tag_free(tag);
+
+	return 0;
+}
+
+static int retrieve_peeled_tag_or_object_oid(
+	git_oid *peeled_out,
+	git_oid *ref_target_out,
+	git_repository *repo,
+	const char *refname)
+{
+	git_reference *ref;
+	git_object *peeled = NULL;
+	int error;
+
+	if ((error = git_reference_lookup_resolved(&ref, repo, refname, -1)) < 0)
+		return error;
+
+	if ((error = git_reference_peel(&peeled, ref, GIT_OBJ_ANY)) < 0)
+		goto cleanup;
+
+	git_oid_cpy(ref_target_out, git_reference_target(ref));
+	git_oid_cpy(peeled_out, git_object_id(peeled));
+
+	if (git_oid_cmp(ref_target_out, peeled_out) != 0)
+		error = 1; /* The reference was pointing to a annotated tag */
+	else
+		error = 0; /* Any other object */
+
+cleanup:
+	git_reference_free(ref);
+	git_object_free(peeled);
+	return error;
+}
+
+struct git_describe_result {
+	int dirty;
+	int exact_match;
+	int fallback_to_id;
+	git_oid commit_id;
+	git_repository *repo;
+	struct commit_name *name;
+	struct possible_tag *tag;
+};
+
+struct get_name_data
+{
+	git_describe_options *opts;
+	git_repository *repo;
+	git_oidmap *names;
+	git_describe_result *result;
+};
+
+static int commit_name_dup(struct commit_name **out, struct commit_name *in)
+{
+	struct commit_name *name;
+
+	name = git__malloc(sizeof(struct commit_name));
+	GITERR_CHECK_ALLOC(name);
+
+	memcpy(name, in,  sizeof(struct commit_name));
+	name->tag = NULL;
+	name->path = NULL;
+
+	if (in->tag && git_tag_dup(&name->tag, in->tag) < 0)
+		return -1;
+
+	name->path = git__strdup(in->path);
+	GITERR_CHECK_ALLOC(name->path);
+
+	*out = name;
+	return 0;
+}
+
+static int get_name(const char *refname, void *payload)
+{
+	struct get_name_data *data;
+	bool is_tag, is_annotated, all;
+	git_oid peeled, sha1;
+	unsigned int prio;
+	int error = 0;
+
+	data = (struct get_name_data *)payload;
+	is_tag = !git__prefixcmp(refname, GIT_REFS_TAGS_DIR);
+	all = data->opts->describe_strategy == GIT_DESCRIBE_ALL;
+
+	/* Reject anything outside refs/tags/ unless --all */
+	if (!all && !is_tag)
+		return 0;
+
+	/* Accept only tags that match the pattern, if given */
+	if (data->opts->pattern && (!is_tag || p_fnmatch(data->opts->pattern,
+		refname + strlen(GIT_REFS_TAGS_DIR), 0)))
+				return 0;
+
+	/* Is it annotated? */
+	if ((error = retrieve_peeled_tag_or_object_oid(
+		&peeled, &sha1, data->repo, refname)) < 0)
+		return error;
+
+	is_annotated = error;
+
+	/*
+	 * By default, we only use annotated tags, but with --tags
+	 * we fall back to lightweight ones (even without --tags,
+	 * we still remember lightweight ones, only to give hints
+	 * in an error message).  --all allows any refs to be used.
+	 */
+	if (is_annotated)
+		prio = 2;
+	else if (is_tag)
+		prio = 1;
+	else
+		prio = 0;
+
+	add_to_known_names(data->repo, data->names,
+		all ? refname + strlen(GIT_REFS_DIR) : refname + strlen(GIT_REFS_TAGS_DIR),
+		&peeled, prio, &sha1);
+	return 0;
+}
+
+struct possible_tag {
+	struct commit_name *name;
+	int depth;
+	int found_order;
+	unsigned flag_within;
+};
+
+static int possible_tag_dup(struct possible_tag **out, struct possible_tag *in)
+{
+	struct possible_tag *tag;
+	int error;
+
+	tag = git__malloc(sizeof(struct possible_tag));
+	GITERR_CHECK_ALLOC(tag);
+
+	memcpy(tag, in, sizeof(struct possible_tag));
+	tag->name = NULL;
+
+	if ((error = commit_name_dup(&tag->name, in->name)) < 0) {
+		git__free(tag);
+		*out = NULL;
+		return error;
+	}
+
+	*out = tag;
+	return 0;
+}
+
+static int compare_pt(const void *a_, const void *b_)
+{
+	struct possible_tag *a = (struct possible_tag *)a_;
+	struct possible_tag *b = (struct possible_tag *)b_;
+	if (a->depth != b->depth)
+		return a->depth - b->depth;
+	if (a->found_order != b->found_order)
+		return a->found_order - b->found_order;
+	return 0;
+}
+
+#define SEEN (1u << 0)
+
+static unsigned long finish_depth_computation(
+	git_pqueue *list,
+	git_revwalk *walk,
+	struct possible_tag *best)
+{
+	unsigned long seen_commits = 0;
+	int error, i;
+
+	while (git_pqueue_size(list) > 0) {
+		git_commit_list_node *c = git_pqueue_pop(list);
+		seen_commits++;
+		if (c->flags & best->flag_within) {
+			size_t index = 0;
+			while (git_pqueue_size(list) > index) {
+				git_commit_list_node *i = git_pqueue_get(list, index);
+				if (!(i->flags & best->flag_within))
+					break;
+				index++;
+			}
+			if (index > git_pqueue_size(list))
+				break;
+		} else
+			best->depth++;
+		for (i = 0; i < c->out_degree; i++) {
+			git_commit_list_node *p = c->parents[i];
+			if ((error = git_commit_list_parse(walk, p)) < 0)
+				return error;
+			if (!(p->flags & SEEN))
+				if ((error = git_pqueue_insert(list, p)) < 0)
+					return error;
+			p->flags |= c->flags;
+		}
+	}
+	return seen_commits;
+}
+
+static int display_name(git_buf *buf, git_repository *repo, struct commit_name *n)
+{
+	if (n->prio == 2 && !n->tag) {
+		if (git_tag_lookup(&n->tag, repo, &n->sha1) < 0) {
+			giterr_set(GITERR_TAG, "annotated tag '%s' not available", n->path);
+			return -1;
+		}
+	}
+
+	if (n->tag && !n->name_checked) {
+		if (!git_tag_name(n->tag)) {
+			giterr_set(GITERR_TAG, "annotated tag '%s' has no embedded name", n->path);
+			return -1;
+		}
+
+		/* TODO: Cope with warnings
+		if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
+			warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
+		*/
+
+		n->name_checked = 1;
+	}
+
+	if (n->tag)
+		git_buf_printf(buf, "%s", git_tag_name(n->tag));
+	else
+		git_buf_printf(buf, "%s", n->path);
+
+	return 0;
+}
+
+static int find_unique_abbrev_size(
+	int *out,
+	git_repository *repo,
+	const git_oid *oid_in,
+	int abbreviated_size)
+{
+	size_t size = abbreviated_size;
+	git_odb *odb;
+	git_oid dummy;
+	int error;
+
+	if ((error = git_repository_odb__weakptr(&odb, repo)) < 0)
+		return error;
+
+	while (size < GIT_OID_HEXSZ) {
+		if ((error = git_odb_exists_prefix(&dummy, odb, oid_in, size)) == 0) {
+			*out = (int) size;
+			return 0;
+		}
+
+		/* If the error wasn't that it's not unique, then it's a proper error */
+		if (error != GIT_EAMBIGUOUS)
+			return error;
+
+		/* Try again with a larger size */
+		size++;
+	}
+
+	/* If we didn't find any shorter prefix, we have to do the whole thing */
+	*out = GIT_OID_HEXSZ;
+	
+	return 0;
+}
+
+static int show_suffix(
+	git_buf *buf,
+	int depth,
+	git_repository *repo,
+	const git_oid* id,
+	size_t abbrev_size)
+{
+	int error, size = 0;
+
+	char hex_oid[GIT_OID_HEXSZ];
+
+	if ((error = find_unique_abbrev_size(&size, repo, id, abbrev_size)) < 0)
+		return error;
+
+	git_oid_fmt(hex_oid, id);
+
+	git_buf_printf(buf, "-%d-g", depth);
+
+	git_buf_put(buf, hex_oid, size);
+
+	return git_buf_oom(buf) ? -1 : 0;
+}
+
+#define MAX_CANDIDATES_TAGS FLAG_BITS - 1
+
+static int describe_not_found(const git_oid *oid, const char *message_format) {
+	char oid_str[GIT_OID_HEXSZ + 1];
+	git_oid_tostr(oid_str, sizeof(oid_str), oid);
+
+	giterr_set(GITERR_DESCRIBE, message_format, oid_str);
+	return GIT_ENOTFOUND;
+}
+
+static int describe(
+	struct get_name_data *data,
+	git_commit *commit)
+{
+	struct commit_name *n;
+	struct possible_tag *best;
+	bool all, tags;
+	git_revwalk *walk = NULL;
+	git_pqueue list;
+	git_commit_list_node *cmit, *gave_up_on = NULL;
+	git_vector all_matches = GIT_VECTOR_INIT;
+	unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
+	unsigned long seen_commits = 0;	/* TODO: Check long */
+	unsigned int unannotated_cnt = 0;
+	int error;
+
+	if (git_vector_init(&all_matches, MAX_CANDIDATES_TAGS, compare_pt) < 0)
+		return -1;
+
+	if ((error = git_pqueue_init(&list, 0, 2, git_commit_list_time_cmp)) < 0)
+		goto cleanup;
+
+	all = data->opts->describe_strategy == GIT_DESCRIBE_ALL;
+	tags = data->opts->describe_strategy == GIT_DESCRIBE_TAGS;
+
+	git_oid_cpy(&data->result->commit_id, git_commit_id(commit));
+
+	n = find_commit_name(data->names, git_commit_id(commit));
+	if (n && (tags || all || n->prio == 2)) {
+		/*
+		 * Exact match to an existing ref.
+		 */
+		data->result->exact_match = 1;
+		if ((error = commit_name_dup(&data->result->name, n)) < 0)
+			goto cleanup;
+
+		goto cleanup;
+	}
+
+	if (!data->opts->max_candidates_tags) {
+		error = describe_not_found(
+			git_commit_id(commit),
+			"cannot describe - no tag exactly matches '%s'");
+
+		goto cleanup;
+	}
+
+	if ((error = git_revwalk_new(&walk, git_commit_owner(commit))) < 0)
+		goto cleanup;
+
+	if ((cmit = git_revwalk__commit_lookup(walk, git_commit_id(commit))) == NULL)
+		goto cleanup;
+
+	if ((error = git_commit_list_parse(walk, cmit)) < 0)
+		goto cleanup;
+
+	cmit->flags = SEEN;
+
+	if ((error = git_pqueue_insert(&list, cmit)) < 0)
+		goto cleanup;
+
+	while (git_pqueue_size(&list) > 0)
+	{
+		int i;
+
+		git_commit_list_node *c = (git_commit_list_node *)git_pqueue_pop(&list);
+		seen_commits++;
+
+		n = find_commit_name(data->names, &c->oid);
+
+		if (n) {
+			if (!tags && !all && n->prio < 2) {
+				unannotated_cnt++;
+			} else if (match_cnt < data->opts->max_candidates_tags) {
+				struct possible_tag *t = git__malloc(sizeof(struct commit_name));
+				GITERR_CHECK_ALLOC(t);
+				if ((error = git_vector_insert(&all_matches, t)) < 0)
+					goto cleanup;
+
+				match_cnt++;
+
+				t->name = n;
+				t->depth = seen_commits - 1;
+				t->flag_within = 1u << match_cnt;
+				t->found_order = match_cnt;
+				c->flags |= t->flag_within;
+				if (n->prio == 2)
+					annotated_cnt++;
+			}
+			else {
+				gave_up_on = c;
+				break;
+			}
+		}
+
+		for (cur_match = 0; cur_match < match_cnt; cur_match++) {
+			struct possible_tag *t = git_vector_get(&all_matches, cur_match);
+			if (!(c->flags & t->flag_within))
+				t->depth++;
+		}
+
+		if (annotated_cnt && (git_pqueue_size(&list) == 0)) {
+			/*
+			if (debug) {
+				char oid_str[GIT_OID_HEXSZ + 1];
+				git_oid_tostr(oid_str, sizeof(oid_str), &c->oid);
+
+				fprintf(stderr, "finished search at %s\n", oid_str);
+			}
+			*/
+			break;
+		}
+		for (i = 0; i < c->out_degree; i++) {
+			git_commit_list_node *p = c->parents[i];
+			if ((error = git_commit_list_parse(walk, p)) < 0)
+				goto cleanup;
+			if (!(p->flags & SEEN))
+				if ((error = git_pqueue_insert(&list, p)) < 0)
+					goto cleanup;
+			p->flags |= c->flags;
+
+			if (data->opts->only_follow_first_parent)
+				break;
+		}
+	}
+
+	if (!match_cnt) {
+		if (data->opts->show_commit_oid_as_fallback) {
+			data->result->fallback_to_id = 1;
+			git_oid_cpy(&data->result->commit_id, &cmit->oid);
+
+			goto cleanup;
+		}
+		if (unannotated_cnt) {
+			error = describe_not_found(git_commit_id(commit), 
+				"cannot describe - "
+				"no annotated tags can describe '%s'; "
+			    "however, there were unannotated tags.");
+			goto cleanup;
+		}
+		else {
+			error = describe_not_found(git_commit_id(commit), 
+				"cannot describe - "
+				"no tags can describe '%s'.");
+			goto cleanup;
+		}
+	}
+
+	git_vector_sort(&all_matches);
+
+	best = (struct possible_tag *)git_vector_get(&all_matches, 0);
+
+	if (gave_up_on) {
+		if ((error = git_pqueue_insert(&list, gave_up_on)) < 0)
+			goto cleanup;
+		seen_commits--;
+	}
+	if ((error = finish_depth_computation(
+		&list, walk, best)) < 0)
+		goto cleanup;
+
+	seen_commits += error;
+	if ((error = possible_tag_dup(&data->result->tag, best)) < 0)
+		goto cleanup;
+
+	/*
+	{
+		static const char *prio_names[] = {
+			"head", "lightweight", "annotated",
+		};
+
+		char oid_str[GIT_OID_HEXSZ + 1];
+
+		if (debug) {
+			for (cur_match = 0; cur_match < match_cnt; cur_match++) {
+				struct possible_tag *t = (struct possible_tag *)git_vector_get(&all_matches, cur_match);
+				fprintf(stderr, " %-11s %8d %s\n",
+					prio_names[t->name->prio],
+					t->depth, t->name->path);
+			}
+			fprintf(stderr, "traversed %lu commits\n", seen_commits);
+			if (gave_up_on) {
+				git_oid_tostr(oid_str, sizeof(oid_str), &gave_up_on->oid);
+				fprintf(stderr,
+					"more than %i tags found; listed %i most recent\n"
+					"gave up search at %s\n",
+					data->opts->max_candidates_tags, data->opts->max_candidates_tags,
+					oid_str);
+			}
+		}
+	}
+	*/
+
+	git_oid_cpy(&data->result->commit_id, &cmit->oid);
+
+cleanup:
+	{
+		size_t i;
+		struct possible_tag *match;
+		git_vector_foreach(&all_matches, i, match) {
+			git__free(match);
+		}
+	}
+	git_vector_free(&all_matches);
+	git_pqueue_free(&list);
+	git_revwalk_free(walk);
+	return error;
+}
+
+static int normalize_options(
+	git_describe_options *dst,
+	const git_describe_options *src)
+{
+	git_describe_options default_options = GIT_DESCRIBE_OPTIONS_INIT;
+	if (!src) src = &default_options;
+
+	*dst = *src;
+
+	if (dst->max_candidates_tags > GIT_DESCRIBE_DEFAULT_MAX_CANDIDATES_TAGS)
+		dst->max_candidates_tags = GIT_DESCRIBE_DEFAULT_MAX_CANDIDATES_TAGS;
+
+	return 0;
+}
+
+int git_describe_commit(
+	git_describe_result **result,
+	git_object *committish,
+	git_describe_options *opts)
+{
+	struct get_name_data data;
+	struct commit_name *name;
+	git_commit *commit;
+	int error = -1;
+	git_describe_options normalized;
+
+	assert(committish);
+
+	data.result = git__calloc(1, sizeof(git_describe_result));
+	GITERR_CHECK_ALLOC(data.result);
+	data.result->repo = git_object_owner(committish);
+
+	data.repo = git_object_owner(committish);
+
+	if ((error = normalize_options(&normalized, opts)) < 0)
+		return error;
+
+	GITERR_CHECK_VERSION(
+		&normalized,
+		GIT_DESCRIBE_OPTIONS_VERSION,
+		"git_describe_options");
+	data.opts = &normalized;
+
+	data.names = git_oidmap_alloc();
+	GITERR_CHECK_ALLOC(data.names);
+
+	/** TODO: contains to be implemented */
+
+	if ((error = git_object_peel((git_object **)(&commit), committish, GIT_OBJ_COMMIT)) < 0)
+		goto cleanup;
+
+	if ((error = git_reference_foreach_name(
+			git_object_owner(committish),
+			get_name, &data)) < 0)
+				goto cleanup;
+
+	if (git_oidmap_size(data.names) == 0 && !opts->show_commit_oid_as_fallback) {
+		giterr_set(GITERR_DESCRIBE, "cannot describe - "
+			"no reference found, cannot describe anything.");
+		error = -1;
+		goto cleanup;
+	}
+
+	if ((error = describe(&data, commit)) < 0)
+		goto cleanup;
+
+cleanup:
+	git_commit_free(commit);
+
+	git_oidmap_foreach_value(data.names, name, {
+		git_tag_free(name->tag);
+		git__free(name->path);
+		git__free(name);
+	});
+
+	git_oidmap_free(data.names);
+
+	if (error < 0)
+		git_describe_result_free(data.result);
+	else
+		*result = data.result;
+
+	return error;
+}
+
+int git_describe_workdir(
+	git_describe_result **out,
+	git_repository *repo,
+	git_describe_options *opts)
+{
+	int error;
+	git_oid current_id;
+	git_status_list *status = NULL;
+	git_status_options status_opts = GIT_STATUS_OPTIONS_INIT;
+	git_describe_result *result = NULL;
+	git_object *commit;
+
+	if ((error = git_reference_name_to_id(&current_id, repo, GIT_HEAD_FILE)) < 0)
+		return error;
+
+	if ((error = git_object_lookup(&commit, repo, &current_id, GIT_OBJ_COMMIT)) < 0)
+		return error;
+
+	/* The first step is to perform a describe of HEAD, so we can leverage this */
+	if ((error = git_describe_commit(&result, commit, opts)) < 0)
+		goto out;
+
+	if ((error = git_status_list_new(&status, repo, &status_opts)) < 0)
+		goto out;
+
+
+	if (git_status_list_entrycount(status) > 0)
+		result->dirty = 1;
+
+out:
+	git_object_free(commit);
+	git_status_list_free(status);
+
+	if (error < 0)
+		git_describe_result_free(result);
+	else
+		*out = result;
+
+	return error;
+}
+
+static int normalize_format_options(
+	git_describe_format_options *dst,
+	const git_describe_format_options *src)
+{
+	if (!src) {
+		git_describe_init_format_options(dst, GIT_DESCRIBE_FORMAT_OPTIONS_VERSION);
+		return 0;
+	}
+
+	memcpy(dst, src, sizeof(git_describe_format_options));
+	return 0;
+}
+
+int git_describe_format(git_buf *out, const git_describe_result *result, const git_describe_format_options *given)
+{
+	int error;
+	git_repository *repo;
+	struct commit_name *name;
+	git_describe_format_options opts;
+
+	assert(out && result);
+
+	GITERR_CHECK_VERSION(given, GIT_DESCRIBE_FORMAT_OPTIONS_VERSION, "git_describe_format_options");
+	normalize_format_options(&opts, given);
+
+	git_buf_sanitize(out);
+
+
+	if (opts.always_use_long_format && opts.abbreviated_size == 0) {
+		giterr_set(GITERR_DESCRIBE, "cannot describe - "
+			"'always_use_long_format' is incompatible with a zero"
+			"'abbreviated_size'");
+		return -1;
+	}
+
+
+	repo = result->repo;
+
+	/* If we did find an exact match, then it's the easier method */
+	if (result->exact_match) {
+		name = result->name;
+		if ((error = display_name(out, repo, name)) < 0)
+			return error;
+
+		if (opts.always_use_long_format) {
+			const git_oid *id = name->tag ? git_tag_target_id(name->tag) : &result->commit_id;
+			if ((error = show_suffix(out, 0, repo, id, opts.abbreviated_size)) < 0)
+				return error;
+		}
+
+		if (result->dirty && opts.dirty_suffix)
+			git_buf_puts(out, opts.dirty_suffix);
+
+		return git_buf_oom(out) ? -1 : 0;
+	}
+
+	/* If we didn't find *any* tags, we fall back to the commit's id */
+	if (result->fallback_to_id) {
+		char hex_oid[GIT_OID_HEXSZ + 1] = {0};
+		int size = 0;
+
+		if ((error = find_unique_abbrev_size(
+			     &size, repo, &result->commit_id, opts.abbreviated_size)) < 0)
+			return -1;
+
+		git_oid_fmt(hex_oid, &result->commit_id);
+		git_buf_put(out, hex_oid, size);
+
+		if (result->dirty && opts.dirty_suffix)
+			git_buf_puts(out, opts.dirty_suffix);
+
+		return git_buf_oom(out) ? -1 : 0;
+	}
+
+	/* Lastly, if we found a matching tag, we show that */
+	name = result->tag->name;
+
+	if ((error = display_name(out, repo, name)) < 0)
+		return error;
+
+	if (opts.abbreviated_size) {
+		if ((error = show_suffix(out, result->tag->depth, repo,
+			&result->commit_id, opts.abbreviated_size)) < 0)
+			return error;
+	}
+
+	if (result->dirty && opts.dirty_suffix) {
+		git_buf_puts(out, opts.dirty_suffix);
+	}
+
+	return git_buf_oom(out) ? -1 : 0;
+}
+
+void git_describe_result_free(git_describe_result *result)
+{
+	if (result == NULL)
+		return;
+
+	if (result->name) {
+		git_tag_free(result->name->tag);
+		git__free(result->name->path);
+		git__free(result->name);
+	}
+
+	if (result->tag) {
+		git_tag_free(result->tag->name->tag);
+		git__free(result->tag->name->path);
+		git__free(result->tag->name);
+		git__free(result->tag);
+	}
+
+	git__free(result);
+}
+
+int git_describe_init_options(git_describe_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_describe_options, GIT_DESCRIBE_OPTIONS_INIT);
+	return 0;
+}
+
+int git_describe_init_format_options(git_describe_format_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_describe_format_options, GIT_DESCRIBE_FORMAT_OPTIONS_INIT);
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/diff.c

diff --git a/vendor/libgit2-sys/libgit2/src/diff.c b/vendor/libgit2-sys/libgit2/src/diff.c
new file mode 100644
index 0000000..c7a6528
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/diff.c
@@ -0,0 +1,515 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "diff.h"
+
+#include "git2/version.h"
+#include "diff_generate.h"
+#include "patch.h"
+#include "commit.h"
+#include "index.h"
+
+struct patch_id_args {
+	git_hash_ctx ctx;
+	git_oid result;
+	int first_file;
+};
+
+GIT_INLINE(const char *) diff_delta__path(const git_diff_delta *delta)
+{
+	const char *str = delta->old_file.path;
+
+	if (!str ||
+		delta->status == GIT_DELTA_ADDED ||
+		delta->status == GIT_DELTA_RENAMED ||
+		delta->status == GIT_DELTA_COPIED)
+		str = delta->new_file.path;
+
+	return str;
+}
+
+const char *git_diff_delta__path(const git_diff_delta *delta)
+{
+	return diff_delta__path(delta);
+}
+
+int git_diff_delta__cmp(const void *a, const void *b)
+{
+	const git_diff_delta *da = a, *db = b;
+	int val = strcmp(diff_delta__path(da), diff_delta__path(db));
+	return val ? val : ((int)da->status - (int)db->status);
+}
+
+int git_diff_delta__casecmp(const void *a, const void *b)
+{
+	const git_diff_delta *da = a, *db = b;
+	int val = strcasecmp(diff_delta__path(da), diff_delta__path(db));
+	return val ? val : ((int)da->status - (int)db->status);
+}
+
+int git_diff__entry_cmp(const void *a, const void *b)
+{
+	const git_index_entry *entry_a = a;
+	const git_index_entry *entry_b = b;
+
+	return strcmp(entry_a->path, entry_b->path);
+}
+
+int git_diff__entry_icmp(const void *a, const void *b)
+{
+	const git_index_entry *entry_a = a;
+	const git_index_entry *entry_b = b;
+
+	return strcasecmp(entry_a->path, entry_b->path);
+}
+
+void git_diff_free(git_diff *diff)
+{
+	if (!diff)
+		return;
+
+	GIT_REFCOUNT_DEC(diff, diff->free_fn);
+}
+
+void git_diff_addref(git_diff *diff)
+{
+	GIT_REFCOUNT_INC(diff);
+}
+
+size_t git_diff_num_deltas(const git_diff *diff)
+{
+	assert(diff);
+	return diff->deltas.length;
+}
+
+size_t git_diff_num_deltas_of_type(const git_diff *diff, git_delta_t type)
+{
+	size_t i, count = 0;
+	const git_diff_delta *delta;
+
+	assert(diff);
+
+	git_vector_foreach(&diff->deltas, i, delta) {
+		count += (delta->status == type);
+	}
+
+	return count;
+}
+
+const git_diff_delta *git_diff_get_delta(const git_diff *diff, size_t idx)
+{
+	assert(diff);
+	return git_vector_get(&diff->deltas, idx);
+}
+
+int git_diff_is_sorted_icase(const git_diff *diff)
+{
+	return (diff->opts.flags & GIT_DIFF_IGNORE_CASE) != 0;
+}
+
+int git_diff_get_perfdata(git_diff_perfdata *out, const git_diff *diff)
+{
+	assert(out);
+	GITERR_CHECK_VERSION(out, GIT_DIFF_PERFDATA_VERSION, "git_diff_perfdata");
+	out->stat_calls = diff->perf.stat_calls;
+	out->oid_calculations = diff->perf.oid_calculations;
+	return 0;
+}
+
+int git_diff_foreach(
+	git_diff *diff,
+	git_diff_file_cb file_cb,
+	git_diff_binary_cb binary_cb,
+	git_diff_hunk_cb hunk_cb,
+	git_diff_line_cb data_cb,
+	void *payload)
+{
+	int error = 0;
+	git_diff_delta *delta;
+	size_t idx;
+
+	assert(diff);
+
+	git_vector_foreach(&diff->deltas, idx, delta) {
+		git_patch *patch;
+
+		/* check flags against patch status */
+		if (git_diff_delta__should_skip(&diff->opts, delta))
+			continue;
+
+		if ((error = git_patch_from_diff(&patch, diff, idx)) != 0)
+			break;
+
+		error = git_patch__invoke_callbacks(patch, file_cb, binary_cb,
+						    hunk_cb, data_cb, payload);
+		git_patch_free(patch);
+
+		if (error)
+			break;
+	}
+
+	return error;
+}
+
+int git_diff_format_email__append_header_tobuf(
+	git_buf *out,
+	const git_oid *id,
+	const git_signature *author,
+	const char *summary,
+	const char *body,
+	size_t patch_no,
+	size_t total_patches,
+	bool exclude_patchno_marker)
+{
+	char idstr[GIT_OID_HEXSZ + 1];
+	char date_str[GIT_DATE_RFC2822_SZ];
+	int error = 0;
+
+	git_oid_fmt(idstr, id);
+	idstr[GIT_OID_HEXSZ] = '\0';
+
+	if ((error = git__date_rfc2822_fmt(date_str, sizeof(date_str),
+		&author->when)) < 0)
+		return error;
+
+	error = git_buf_printf(out,
+				"From %s Mon Sep 17 00:00:00 2001\n" \
+				"From: %s <%s>\n" \
+				"Date: %s\n" \
+				"Subject: ",
+				idstr,
+				author->name, author->email,
+				date_str);
+
+	if (error < 0)
+		return error;
+
+	if (!exclude_patchno_marker) {
+		if (total_patches == 1) {
+			error = git_buf_puts(out, "[PATCH] ");
+		} else {
+			error = git_buf_printf(out, "[PATCH %"PRIuZ"/%"PRIuZ"] ",
+				patch_no, total_patches);
+		}
+
+		if (error < 0)
+			return error;
+	}
+
+	error = git_buf_printf(out, "%s\n\n", summary);
+
+	if (body) {
+		git_buf_puts(out, body);
+
+		if (out->ptr[out->size - 1] != '\n')
+			git_buf_putc(out, '\n');
+	}
+
+	return error;
+}
+
+int git_diff_format_email__append_patches_tobuf(
+	git_buf *out,
+	git_diff *diff)
+{
+	size_t i, deltas;
+	int error = 0;
+
+	deltas = git_diff_num_deltas(diff);
+
+	for (i = 0; i < deltas; ++i) {
+		git_patch *patch = NULL;
+
+		if ((error = git_patch_from_diff(&patch, diff, i)) >= 0)
+			error = git_patch_to_buf(out, patch);
+
+		git_patch_free(patch);
+
+		if (error < 0)
+			break;
+	}
+
+	return error;
+}
+
+int git_diff_format_email(
+	git_buf *out,
+	git_diff *diff,
+	const git_diff_format_email_options *opts)
+{
+	git_diff_stats *stats = NULL;
+	char *summary = NULL, *loc = NULL;
+	bool ignore_marker;
+	unsigned int format_flags = 0;
+	size_t allocsize;
+	int error;
+
+	assert(out && diff && opts);
+	assert(opts->summary && opts->id && opts->author);
+
+	GITERR_CHECK_VERSION(opts,
+		GIT_DIFF_FORMAT_EMAIL_OPTIONS_VERSION,
+		"git_format_email_options");
+
+	ignore_marker = (opts->flags &
+		GIT_DIFF_FORMAT_EMAIL_EXCLUDE_SUBJECT_PATCH_MARKER) != 0;
+
+	if (!ignore_marker) {
+		if (opts->patch_no > opts->total_patches) {
+			giterr_set(GITERR_INVALID,
+				"patch %"PRIuZ" out of range. max %"PRIuZ,
+				opts->patch_no, opts->total_patches);
+			return -1;
+		}
+
+		if (opts->patch_no == 0) {
+			giterr_set(GITERR_INVALID,
+				"invalid patch no %"PRIuZ". should be >0", opts->patch_no);
+			return -1;
+		}
+	}
+
+	/* the summary we receive may not be clean.
+	 * it could potentially contain new line characters
+	 * or not be set, sanitize, */
+	if ((loc = strpbrk(opts->summary, "\r\n")) != NULL) {
+		size_t offset = 0;
+
+		if ((offset = (loc - opts->summary)) == 0) {
+			giterr_set(GITERR_INVALID, "summary is empty");
+			error = -1;
+			goto on_error;
+		}
+
+		GITERR_CHECK_ALLOC_ADD(&allocsize, offset, 1);
+		summary = git__calloc(allocsize, sizeof(char));
+		GITERR_CHECK_ALLOC(summary);
+
+		strncpy(summary, opts->summary, offset);
+	}
+
+	error = git_diff_format_email__append_header_tobuf(out,
+		opts->id, opts->author, summary == NULL ? opts->summary : summary,
+		opts->body, opts->patch_no, opts->total_patches, ignore_marker);
+
+	if (error < 0)
+		goto on_error;
+
+	format_flags = GIT_DIFF_STATS_FULL | GIT_DIFF_STATS_INCLUDE_SUMMARY;
+
+	if ((error = git_buf_puts(out, "---\n")) < 0 ||
+		(error = git_diff_get_stats(&stats, diff)) < 0 ||
+		(error = git_diff_stats_to_buf(out, stats, format_flags, 0)) < 0 ||
+		(error = git_buf_putc(out, '\n')) < 0 ||
+		(error = git_diff_format_email__append_patches_tobuf(out, diff)) < 0)
+			goto on_error;
+
+	error = git_buf_puts(out, "--\nlibgit2 " LIBGIT2_VERSION "\n\n");
+
+on_error:
+	git__free(summary);
+	git_diff_stats_free(stats);
+
+	return error;
+}
+
+int git_diff_commit_as_email(
+	git_buf *out,
+	git_repository *repo,
+	git_commit *commit,
+	size_t patch_no,
+	size_t total_patches,
+	git_diff_format_email_flags_t flags,
+	const git_diff_options *diff_opts)
+{
+	git_diff *diff = NULL;
+	git_diff_format_email_options opts =
+		GIT_DIFF_FORMAT_EMAIL_OPTIONS_INIT;
+	int error;
+
+	assert (out && repo && commit);
+
+	opts.flags = flags;
+	opts.patch_no = patch_no;
+	opts.total_patches = total_patches;
+	opts.id = git_commit_id(commit);
+	opts.summary = git_commit_summary(commit);
+	opts.body = git_commit_body(commit);
+	opts.author = git_commit_author(commit);
+
+	if ((error = git_diff__commit(&diff, repo, commit, diff_opts)) < 0)
+		return error;
+
+	error = git_diff_format_email(out, diff, &opts);
+
+	git_diff_free(diff);
+	return error;
+}
+
+int git_diff_init_options(git_diff_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_diff_options, GIT_DIFF_OPTIONS_INIT);
+	return 0;
+}
+
+int git_diff_find_init_options(
+	git_diff_find_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_diff_find_options, GIT_DIFF_FIND_OPTIONS_INIT);
+	return 0;
+}
+
+int git_diff_format_email_init_options(
+	git_diff_format_email_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_diff_format_email_options,
+		GIT_DIFF_FORMAT_EMAIL_OPTIONS_INIT);
+	return 0;
+}
+
+static int flush_hunk(git_oid *result, git_hash_ctx *ctx)
+{
+	git_oid hash;
+	unsigned short carry = 0;
+	int error, i;
+
+	if ((error = git_hash_final(&hash, ctx)) < 0 ||
+	    (error = git_hash_init(ctx)) < 0)
+		return error;
+
+	for (i = 0; i < GIT_OID_RAWSZ; i++) {
+		carry += result->id[i] + hash.id[i];
+		result->id[i] = carry;
+		carry >>= 8;
+	}
+
+	return 0;
+}
+
+static void strip_spaces(git_buf *buf)
+{
+	char *src = buf->ptr, *dst = buf->ptr;
+	char c;
+	size_t len = 0;
+
+	while ((c = *src++) != '\0') {
+		if (!git__isspace(c)) {
+			*dst++ = c;
+			len++;
+		}
+	}
+
+	git_buf_truncate(buf, len);
+}
+
+static int file_cb(
+	const git_diff_delta *delta,
+	float progress,
+	void *payload)
+{
+	struct patch_id_args *args = (struct patch_id_args *) payload;
+	git_buf buf = GIT_BUF_INIT;
+	int error;
+
+	GIT_UNUSED(progress);
+
+	if (!args->first_file &&
+	    (error = flush_hunk(&args->result, &args->ctx)) < 0)
+		goto out;
+	args->first_file = 0;
+
+	if ((error = git_buf_printf(&buf,
+				    "diff--gita/%sb/%s---a/%s+++b/%s",
+				    delta->old_file.path,
+				    delta->new_file.path,
+				    delta->old_file.path,
+				    delta->new_file.path)) < 0)
+		goto out;
+
+	strip_spaces(&buf);
+
+	if ((error = git_hash_update(&args->ctx, buf.ptr, buf.size)) < 0)
+		goto out;
+
+out:
+	git_buf_free(&buf);
+	return error;
+}
+
+static int line_cb(
+	const git_diff_delta *delta,
+	const git_diff_hunk *hunk,
+	const git_diff_line *line,
+	void *payload)
+{
+	struct patch_id_args *args = (struct patch_id_args *) payload;
+	git_buf buf = GIT_BUF_INIT;
+	int error;
+
+	GIT_UNUSED(delta);
+	GIT_UNUSED(hunk);
+
+	switch (line->origin) {
+	    case GIT_DIFF_LINE_ADDITION:
+		git_buf_putc(&buf, '+');
+		break;
+	    case GIT_DIFF_LINE_DELETION:
+		git_buf_putc(&buf, '-');
+		break;
+	    case GIT_DIFF_LINE_CONTEXT:
+		break;
+	    default:
+		giterr_set(GITERR_PATCH, "invalid line origin for patch");
+		return -1;
+	}
+
+	git_buf_put(&buf, line->content, line->content_len);
+	strip_spaces(&buf);
+
+	if ((error = git_hash_update(&args->ctx, buf.ptr, buf.size)) < 0)
+		goto out;
+
+out:
+	git_buf_free(&buf);
+	return error;
+}
+
+int git_diff_patchid_init_options(git_diff_patchid_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_diff_patchid_options, GIT_DIFF_PATCHID_OPTIONS_INIT);
+	return 0;
+}
+
+int git_diff_patchid(git_oid *out, git_diff *diff, git_diff_patchid_options *opts)
+{
+	struct patch_id_args args;
+	int error;
+
+	GITERR_CHECK_VERSION(
+		opts, GIT_DIFF_PATCHID_OPTIONS_VERSION, "git_diff_patchid_options");
+
+	memset(&args, 0, sizeof(args));
+	args.first_file = 1;
+	if ((error = git_hash_ctx_init(&args.ctx)) < 0)
+		goto out;
+
+	if ((error = git_diff_foreach(diff, file_cb, NULL, NULL, line_cb, &args)) < 0)
+		goto out;
+
+	if ((error = (flush_hunk(&args.result, &args.ctx))) < 0)
+		goto out;
+
+	git_oid_cpy(out, &args.result);
+
+out:
+	git_hash_ctx_cleanup(&args.ctx);
+	return error;
+}

vendor/libgit2-sys/libgit2/src/diff.h

diff --git a/vendor/libgit2-sys/libgit2/src/diff.h b/vendor/libgit2-sys/libgit2/src/diff.h
new file mode 100644
index 0000000..93374b9
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/diff.h
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_diff_h__
+#define INCLUDE_diff_h__
+
+#include "common.h"
+
+#include "git2/diff.h"
+#include "git2/patch.h"
+#include "git2/sys/diff.h"
+#include "git2/oid.h"
+
+#include <stdio.h>
+#include "vector.h"
+#include "buffer.h"
+#include "iterator.h"
+#include "repository.h"
+#include "pool.h"
+#include "odb.h"
+
+#define DIFF_OLD_PREFIX_DEFAULT "a/"
+#define DIFF_NEW_PREFIX_DEFAULT "b/"
+
+typedef enum {
+	GIT_DIFF_TYPE_UNKNOWN = 0,
+	GIT_DIFF_TYPE_GENERATED = 1,
+	GIT_DIFF_TYPE_PARSED = 2,
+} git_diff_origin_t;
+
+struct git_diff {
+	git_refcount     rc;
+	git_repository   *repo;
+	git_attr_session attrsession;
+	git_diff_origin_t type;
+	git_diff_options opts;
+	git_vector       deltas;    /* vector of git_diff_delta */
+	git_pool pool;
+	git_iterator_type_t old_src;
+	git_iterator_type_t new_src;
+	git_diff_perfdata perf;
+
+	int (*strcomp)(const char *, const char *);
+	int (*strncomp)(const char *, const char *, size_t);
+	int (*pfxcomp)(const char *str, const char *pfx);
+	int (*entrycomp)(const void *a, const void *b);
+
+	int (*patch_fn)(git_patch **out, git_diff *diff, size_t idx);
+	void (*free_fn)(git_diff *diff);
+};
+
+extern int git_diff_delta__format_file_header(
+	git_buf *out,
+	const git_diff_delta *delta,
+	const char *oldpfx,
+	const char *newpfx,
+	int oid_strlen);
+
+extern int git_diff_delta__cmp(const void *a, const void *b);
+extern int git_diff_delta__casecmp(const void *a, const void *b);
+
+extern int git_diff__entry_cmp(const void *a, const void *b);
+extern int git_diff__entry_icmp(const void *a, const void *b);
+
+#endif

vendor/libgit2-sys/libgit2/src/diff_driver.c

diff --git a/vendor/libgit2-sys/libgit2/src/diff_driver.c b/vendor/libgit2-sys/libgit2/src/diff_driver.c
new file mode 100644
index 0000000..7114b06
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/diff_driver.c
@@ -0,0 +1,522 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "diff_driver.h"
+
+#include "git2/attr.h"
+
+#include "diff.h"
+#include "strmap.h"
+#include "map.h"
+#include "buf_text.h"
+#include "config.h"
+#include "repository.h"
+
+typedef enum {
+	DIFF_DRIVER_AUTO = 0,
+	DIFF_DRIVER_BINARY = 1,
+	DIFF_DRIVER_TEXT = 2,
+	DIFF_DRIVER_PATTERNLIST = 3,
+} git_diff_driver_t;
+
+typedef struct {
+	regex_t re;
+	int flags;
+} git_diff_driver_pattern;
+
+enum {
+	REG_NEGATE = (1 << 15) /* get out of the way of existing flags */
+};
+
+/* data for finding function context for a given file type */
+struct git_diff_driver {
+	git_diff_driver_t type;
+	uint32_t binary_flags;
+	uint32_t other_flags;
+	git_array_t(git_diff_driver_pattern) fn_patterns;
+	regex_t  word_pattern;
+	char name[GIT_FLEX_ARRAY];
+};
+
+#include "userdiff.h"
+
+struct git_diff_driver_registry {
+	git_strmap *drivers;
+};
+
+#define FORCE_DIFFABLE (GIT_DIFF_FORCE_TEXT | GIT_DIFF_FORCE_BINARY)
+
+static git_diff_driver global_drivers[3] = {
+	{ DIFF_DRIVER_AUTO,   0, 0, },
+	{ DIFF_DRIVER_BINARY, GIT_DIFF_FORCE_BINARY, 0 },
+	{ DIFF_DRIVER_TEXT,   GIT_DIFF_FORCE_TEXT, 0 },
+};
+
+git_diff_driver_registry *git_diff_driver_registry_new(void)
+{
+	git_diff_driver_registry *reg =
+		git__calloc(1, sizeof(git_diff_driver_registry));
+	if (!reg)
+		return NULL;
+
+	if (git_strmap_alloc(&reg->drivers) < 0) {
+		git_diff_driver_registry_free(reg);
+		return NULL;
+	}
+
+	return reg;
+}
+
+void git_diff_driver_registry_free(git_diff_driver_registry *reg)
+{
+	git_diff_driver *drv;
+
+	if (!reg)
+		return;
+
+	git_strmap_foreach_value(reg->drivers, drv, git_diff_driver_free(drv));
+	git_strmap_free(reg->drivers);
+	git__free(reg);
+}
+
+static int diff_driver_add_patterns(
+	git_diff_driver *drv, const char *regex_str, int regex_flags)
+{
+	int error = 0;
+	const char *scan, *end;
+	git_diff_driver_pattern *pat = NULL;
+	git_buf buf = GIT_BUF_INIT;
+
+	for (scan = regex_str; scan; scan = end) {
+		/* get pattern to fill in */
+		if ((pat = git_array_alloc(drv->fn_patterns)) == NULL) {
+			return -1;
+		}
+
+		pat->flags = regex_flags;
+		if (*scan == '!') {
+			pat->flags |= REG_NEGATE;
+			++scan;
+		}
+
+		if ((end = strchr(scan, '\n')) != NULL) {
+			error = git_buf_set(&buf, scan, end - scan);
+			end++;
+		} else {
+			error = git_buf_sets(&buf, scan);
+		}
+		if (error < 0)
+			break;
+
+		if ((error = p_regcomp(&pat->re, buf.ptr, regex_flags)) != 0) {
+			/*
+			 * TODO: issue a warning
+			 */
+		}
+	}
+
+	if (error && pat != NULL)
+		(void)git_array_pop(drv->fn_patterns); /* release last item */
+	git_buf_free(&buf);
+
+	/* We want to ignore bad patterns, so return success regardless */
+	return 0;
+}
+
+static int diff_driver_xfuncname(const git_config_entry *entry, void *payload)
+{
+	return diff_driver_add_patterns(payload, entry->value, REG_EXTENDED);
+}
+
+static int diff_driver_funcname(const git_config_entry *entry, void *payload)
+{
+	return diff_driver_add_patterns(payload, entry->value, 0);
+}
+
+static git_diff_driver_registry *git_repository_driver_registry(
+	git_repository *repo)
+{
+	if (!repo->diff_drivers) {
+		git_diff_driver_registry *reg = git_diff_driver_registry_new();
+		reg = git__compare_and_swap(&repo->diff_drivers, NULL, reg);
+
+		if (reg != NULL) /* if we race, free losing allocation */
+			git_diff_driver_registry_free(reg);
+	}
+
+	if (!repo->diff_drivers)
+		giterr_set(GITERR_REPOSITORY, "unable to create diff driver registry");
+
+	return repo->diff_drivers;
+}
+
+static int diff_driver_alloc(
+	git_diff_driver **out, size_t *namelen_out, const char *name)
+{
+	git_diff_driver *driver;
+	size_t driverlen = sizeof(git_diff_driver),
+		namelen = strlen(name),
+		alloclen;
+
+	GITERR_CHECK_ALLOC_ADD(&alloclen, driverlen, namelen);
+	GITERR_CHECK_ALLOC_ADD(&alloclen, alloclen, 1);
+
+	driver = git__calloc(1, alloclen);
+	GITERR_CHECK_ALLOC(driver);
+
+	memcpy(driver->name, name, namelen);
+
+	*out = driver;
+
+	if (namelen_out)
+		*namelen_out = namelen;
+
+	return 0;
+}
+
+static int git_diff_driver_builtin(
+	git_diff_driver **out,
+	git_diff_driver_registry *reg,
+	const char *driver_name)
+{
+	int error = 0;
+	git_diff_driver_definition *ddef = NULL;
+	git_diff_driver *drv = NULL;
+	size_t idx;
+
+	for (idx = 0; idx < ARRAY_SIZE(builtin_defs); ++idx) {
+		if (!strcasecmp(driver_name, builtin_defs[idx].name)) {
+			ddef = &builtin_defs[idx];
+			break;
+		}
+	}
+	if (!ddef)
+		goto done;
+
+	if ((error = diff_driver_alloc(&drv, NULL, ddef->name)) < 0)
+		goto done;
+
+	drv->type = DIFF_DRIVER_PATTERNLIST;
+
+	if (ddef->fns &&
+		(error = diff_driver_add_patterns(
+			drv, ddef->fns, ddef->flags | REG_EXTENDED)) < 0)
+		goto done;
+
+	if (ddef->words &&
+		(error = p_regcomp(
+			&drv->word_pattern, ddef->words, ddef->flags | REG_EXTENDED)))
+	{
+		error = giterr_set_regex(&drv->word_pattern, error);
+		goto done;
+	}
+
+	git_strmap_insert(reg->drivers, drv->name, drv, &error);
+	if (error > 0)
+		error = 0;
+
+done:
+	if (error && drv)
+		git_diff_driver_free(drv);
+	else
+		*out = drv;
+
+	return error;
+}
+
+static int git_diff_driver_load(
+	git_diff_driver **out, git_repository *repo, const char *driver_name)
+{
+	int error = 0;
+	git_diff_driver_registry *reg;
+	git_diff_driver *drv = NULL;
+	size_t namelen;
+	khiter_t pos;
+	git_config *cfg = NULL;
+	git_buf name = GIT_BUF_INIT;
+	git_config_entry *ce = NULL;
+	bool found_driver = false;
+
+	if ((reg = git_repository_driver_registry(repo)) == NULL)
+		return -1;
+
+	pos = git_strmap_lookup_index(reg->drivers, driver_name);
+	if (git_strmap_valid_index(reg->drivers, pos)) {
+		*out = git_strmap_value_at(reg->drivers, pos);
+		return 0;
+	}
+
+	if ((error = diff_driver_alloc(&drv, &namelen, driver_name)) < 0)
+		goto done;
+
+	drv->type = DIFF_DRIVER_AUTO;
+
+	/* if you can't read config for repo, just use default driver */
+	if (git_repository_config_snapshot(&cfg, repo) < 0) {
+		giterr_clear();
+		goto done;
+	}
+
+	if ((error = git_buf_printf(&name, "diff.%s.binary", driver_name)) < 0)
+		goto done;
+
+	switch (git_config__get_bool_force(cfg, name.ptr, -1)) {
+	case true:
+		/* if diff.<driver>.binary is true, just return the binary driver */
+		*out = &global_drivers[DIFF_DRIVER_BINARY];
+		goto done;
+	case false:
+		/* if diff.<driver>.binary is false, force binary checks off */
+		/* but still may have custom function context patterns, etc. */
+		drv->binary_flags = GIT_DIFF_FORCE_TEXT;
+		found_driver = true;
+		break;
+	default:
+		/* diff.<driver>.binary unspecified or "auto", so just continue */
+		break;
+	}
+
+	/* TODO: warn if diff.<name>.command or diff.<name>.textconv are set */
+
+	git_buf_truncate(&name, namelen + strlen("diff.."));
+	git_buf_put(&name, "xfuncname", strlen("xfuncname"));
+	if ((error = git_config_get_multivar_foreach(
+			cfg, name.ptr, NULL, diff_driver_xfuncname, drv)) < 0) {
+		if (error != GIT_ENOTFOUND)
+			goto done;
+		giterr_clear(); /* no diff.<driver>.xfuncname, so just continue */
+	}
+
+	git_buf_truncate(&name, namelen + strlen("diff.."));
+	git_buf_put(&name, "funcname", strlen("funcname"));
+	if ((error = git_config_get_multivar_foreach(
+			cfg, name.ptr, NULL, diff_driver_funcname, drv)) < 0) {
+		if (error != GIT_ENOTFOUND)
+			goto done;
+		giterr_clear(); /* no diff.<driver>.funcname, so just continue */
+	}
+
+	/* if we found any patterns, set driver type to use correct callback */
+	if (git_array_size(drv->fn_patterns) > 0) {
+		drv->type = DIFF_DRIVER_PATTERNLIST;
+		found_driver = true;
+	}
+
+	git_buf_truncate(&name, namelen + strlen("diff.."));
+	git_buf_put(&name, "wordregex", strlen("wordregex"));
+	if ((error = git_config__lookup_entry(&ce, cfg, name.ptr, false)) < 0)
+		goto done;
+	if (!ce || !ce->value)
+		/* no diff.<driver>.wordregex, so just continue */;
+	else if (!(error = p_regcomp(&drv->word_pattern, ce->value, REG_EXTENDED)))
+		found_driver = true;
+	else {
+		/* TODO: warn about bad regex instead of failure */
+		error = giterr_set_regex(&drv->word_pattern, error);
+		goto done;
+	}
+
+	/* TODO: look up diff.<driver>.algorithm to turn on minimal / patience
+	 * diff in drv->other_flags
+	 */
+
+	/* if no driver config found at all, fall back on AUTO driver */
+	if (!found_driver)
+		goto done;
+
+	/* store driver in registry */
+	git_strmap_insert(reg->drivers, drv->name, drv, &error);
+	if (error < 0)
+		goto done;
+	error = 0;
+
+	*out = drv;
+
+done:
+	git_config_entry_free(ce);
+	git_buf_free(&name);
+	git_config_free(cfg);
+
+	if (!*out) {
+		int error2 = git_diff_driver_builtin(out, reg, driver_name);
+		if (!error)
+			error = error2;
+	}
+
+	if (drv && drv != *out)
+		git_diff_driver_free(drv);
+
+	return error;
+}
+
+int git_diff_driver_lookup(
+	git_diff_driver **out, git_repository *repo,
+	git_attr_session *attrsession, const char *path)
+{
+	int error = 0;
+	const char *values[1], *attrs[] = { "diff" };
+
+	assert(out);
+	*out = NULL;
+
+	if (!repo || !path || !strlen(path))
+		/* just use the auto value */;
+	else if ((error = git_attr_get_many_with_session(values, repo,
+			attrsession, 0, path, 1, attrs)) < 0)
+		/* return error below */;
+
+	else if (GIT_ATTR_UNSPECIFIED(values[0]))
+		/* just use the auto value */;
+	else if (GIT_ATTR_FALSE(values[0]))
+		*out = &global_drivers[DIFF_DRIVER_BINARY];
+	else if (GIT_ATTR_TRUE(values[0]))
+		*out = &global_drivers[DIFF_DRIVER_TEXT];
+
+	/* otherwise look for driver information in config and build driver */
+	else if ((error = git_diff_driver_load(out, repo, values[0])) < 0) {
+		if (error == GIT_ENOTFOUND) {
+			error = 0;
+			giterr_clear();
+		}
+	}
+
+	if (!*out)
+		*out = &global_drivers[DIFF_DRIVER_AUTO];
+
+	return error;
+}
+
+void git_diff_driver_free(git_diff_driver *driver)
+{
+	size_t i;
+
+	if (!driver)
+		return;
+
+	for (i = 0; i < git_array_size(driver->fn_patterns); ++i)
+		regfree(& git_array_get(driver->fn_patterns, i)->re);
+	git_array_clear(driver->fn_patterns);
+
+	regfree(&driver->word_pattern);
+
+	git__free(driver);
+}
+
+void git_diff_driver_update_options(
+	uint32_t *option_flags, git_diff_driver *driver)
+{
+	if ((*option_flags & FORCE_DIFFABLE) == 0)
+		*option_flags |= driver->binary_flags;
+
+	*option_flags |= driver->other_flags;
+}
+
+int git_diff_driver_content_is_binary(
+	git_diff_driver *driver, const char *content, size_t content_len)
+{
+	git_buf search = GIT_BUF_INIT;
+
+	GIT_UNUSED(driver);
+
+	git_buf_attach_notowned(&search, content,
+		min(content_len, GIT_FILTER_BYTES_TO_CHECK_NUL));
+
+	/* TODO: provide encoding / binary detection callbacks that can
+	 * be UTF-8 aware, etc.  For now, instead of trying to be smart,
+	 * let's just use the simple NUL-byte detection that core git uses.
+	 */
+
+	/* previously was: if (git_buf_text_is_binary(&search)) */
+	if (git_buf_text_contains_nul(&search))
+		return 1;
+
+	return 0;
+}
+
+static int diff_context_line__simple(
+	git_diff_driver *driver, git_buf *line)
+{
+	char firstch = line->ptr[0];
+	GIT_UNUSED(driver);
+	return (git__isalpha(firstch) || firstch == '_' || firstch == '$');
+}
+
+static int diff_context_line__pattern_match(
+	git_diff_driver *driver, git_buf *line)
+{
+	size_t i, maxi = git_array_size(driver->fn_patterns);
+	regmatch_t pmatch[2];
+
+	for (i = 0; i < maxi; ++i) {
+		git_diff_driver_pattern *pat = git_array_get(driver->fn_patterns, i);
+
+		if (!regexec(&pat->re, line->ptr, 2, pmatch, 0)) {
+			if (pat->flags & REG_NEGATE)
+				return false;
+
+			/* use pmatch data to trim line data */
+			i = (pmatch[1].rm_so >= 0) ? 1 : 0;
+			git_buf_consume(line, git_buf_cstr(line) + pmatch[i].rm_so);
+			git_buf_truncate(line, pmatch[i].rm_eo - pmatch[i].rm_so);
+			git_buf_rtrim(line);
+
+			return true;
+		}
+	}
+
+	return false;
+}
+
+static long diff_context_find(
+	const char *line,
+	long line_len,
+	char *out,
+	long out_size,
+	void *payload)
+{
+	git_diff_find_context_payload *ctxt = payload;
+
+	if (git_buf_set(&ctxt->line, line, (size_t)line_len) < 0)
+		return -1;
+	git_buf_rtrim(&ctxt->line);
+
+	if (!ctxt->line.size)
+		return -1;
+
+	if (!ctxt->match_line || !ctxt->match_line(ctxt->driver, &ctxt->line))
+		return -1;
+
+	if (out_size > (long)ctxt->line.size)
+		out_size = (long)ctxt->line.size;
+	memcpy(out, ctxt->line.ptr, (size_t)out_size);
+
+	return out_size;
+}
+
+void git_diff_find_context_init(
+	git_diff_find_context_fn *findfn_out,
+	git_diff_find_context_payload *payload_out,
+	git_diff_driver *driver)
+{
+	*findfn_out = driver ? diff_context_find : NULL;
+
+	memset(payload_out, 0, sizeof(*payload_out));
+	if (driver) {
+		payload_out->driver = driver;
+		payload_out->match_line = (driver->type == DIFF_DRIVER_PATTERNLIST) ?
+			diff_context_line__pattern_match : diff_context_line__simple;
+		git_buf_init(&payload_out->line, 0);
+	}
+}
+
+void git_diff_find_context_clear(git_diff_find_context_payload *payload)
+{
+	if (payload) {
+		git_buf_free(&payload->line);
+		payload->driver = NULL;
+	}
+}

vendor/libgit2-sys/libgit2/src/diff_driver.h

diff --git a/vendor/libgit2-sys/libgit2/src/diff_driver.h b/vendor/libgit2-sys/libgit2/src/diff_driver.h
new file mode 100644
index 0000000..a03a67e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/diff_driver.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_diff_driver_h__
+#define INCLUDE_diff_driver_h__
+
+#include "common.h"
+
+#include "attr_file.h"
+#include "buffer.h"
+
+typedef struct git_diff_driver_registry git_diff_driver_registry;
+
+git_diff_driver_registry *git_diff_driver_registry_new(void);
+void git_diff_driver_registry_free(git_diff_driver_registry *);
+
+typedef struct git_diff_driver git_diff_driver;
+
+int git_diff_driver_lookup(git_diff_driver **, git_repository *,
+	git_attr_session *attrsession, const char *);
+void git_diff_driver_free(git_diff_driver *);
+
+/* diff option flags to force off and on for this driver */
+void git_diff_driver_update_options(uint32_t *option_flags, git_diff_driver *);
+
+/* returns -1 meaning "unknown", 0 meaning not binary, 1 meaning binary */
+int git_diff_driver_content_is_binary(
+	git_diff_driver *, const char *content, size_t content_len);
+
+typedef long (*git_diff_find_context_fn)(
+	const char *, long, char *, long, void *);
+
+typedef int (*git_diff_find_context_line)(
+	git_diff_driver *, git_buf *);
+
+typedef struct {
+	git_diff_driver *driver;
+	git_diff_find_context_line match_line;
+	git_buf line;
+} git_diff_find_context_payload;
+
+void git_diff_find_context_init(
+	git_diff_find_context_fn *findfn_out,
+	git_diff_find_context_payload *payload_out,
+	git_diff_driver *driver);
+
+void git_diff_find_context_clear(git_diff_find_context_payload *);
+
+#endif

vendor/libgit2-sys/libgit2/src/diff_file.c

diff --git a/vendor/libgit2-sys/libgit2/src/diff_file.c b/vendor/libgit2-sys/libgit2/src/diff_file.c
new file mode 100644
index 0000000..5bb9c37
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/diff_file.c
@@ -0,0 +1,472 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "diff_file.h"
+
+#include "git2/blob.h"
+#include "git2/submodule.h"
+#include "diff.h"
+#include "diff_generate.h"
+#include "odb.h"
+#include "fileops.h"
+#include "filter.h"
+
+#define DIFF_MAX_FILESIZE 0x20000000
+
+static bool diff_file_content_binary_by_size(git_diff_file_content *fc)
+{
+	/* if we have diff opts, check max_size vs file size */
+	if ((fc->file->flags & DIFF_FLAGS_KNOWN_BINARY) == 0 &&
+		fc->opts_max_size > 0 &&
+		fc->file->size > fc->opts_max_size)
+		fc->file->flags |= GIT_DIFF_FLAG_BINARY;
+
+	return ((fc->file->flags & GIT_DIFF_FLAG_BINARY) != 0);
+}
+
+static void diff_file_content_binary_by_content(git_diff_file_content *fc)
+{
+	if ((fc->file->flags & DIFF_FLAGS_KNOWN_BINARY) != 0)
+		return;
+
+	switch (git_diff_driver_content_is_binary(
+		fc->driver, fc->map.data, fc->map.len)) {
+	case 0: fc->file->flags |= GIT_DIFF_FLAG_NOT_BINARY; break;
+	case 1: fc->file->flags |= GIT_DIFF_FLAG_BINARY; break;
+	default: break;
+	}
+}
+
+static int diff_file_content_init_common(
+	git_diff_file_content *fc, const git_diff_options *opts)
+{
+	fc->opts_flags = opts ? opts->flags : GIT_DIFF_NORMAL;
+
+	if (opts && opts->max_size >= 0)
+		fc->opts_max_size = opts->max_size ?
+			opts->max_size : DIFF_MAX_FILESIZE;
+
+	if (fc->src == GIT_ITERATOR_TYPE_EMPTY)
+		fc->src = GIT_ITERATOR_TYPE_TREE;
+
+	if (!fc->driver &&
+		git_diff_driver_lookup(&fc->driver, fc->repo,
+		    NULL, fc->file->path) < 0)
+		return -1;
+
+	/* give driver a chance to modify options */
+	git_diff_driver_update_options(&fc->opts_flags, fc->driver);
+
+	/* make sure file is conceivable mmap-able */
+	if ((git_off_t)((size_t)fc->file->size) != fc->file->size)
+		fc->file->flags |= GIT_DIFF_FLAG_BINARY;
+	/* check if user is forcing text diff the file */
+	else if (fc->opts_flags & GIT_DIFF_FORCE_TEXT) {
+		fc->file->flags &= ~GIT_DIFF_FLAG_BINARY;
+		fc->file->flags |= GIT_DIFF_FLAG_NOT_BINARY;
+	}
+	/* check if user is forcing binary diff the file */
+	else if (fc->opts_flags & GIT_DIFF_FORCE_BINARY) {
+		fc->file->flags &= ~GIT_DIFF_FLAG_NOT_BINARY;
+		fc->file->flags |= GIT_DIFF_FLAG_BINARY;
+	}
+
+	diff_file_content_binary_by_size(fc);
+
+	if ((fc->flags & GIT_DIFF_FLAG__NO_DATA) != 0) {
+		fc->flags |= GIT_DIFF_FLAG__LOADED;
+		fc->map.len  = 0;
+		fc->map.data = "";
+	}
+
+	if ((fc->flags & GIT_DIFF_FLAG__LOADED) != 0)
+		diff_file_content_binary_by_content(fc);
+
+	return 0;
+}
+
+int git_diff_file_content__init_from_diff(
+	git_diff_file_content *fc,
+	git_diff *diff,
+	git_diff_delta *delta,
+	bool use_old)
+{
+	bool has_data = true;
+
+	memset(fc, 0, sizeof(*fc));
+	fc->repo = diff->repo;
+	fc->file = use_old ? &delta->old_file : &delta->new_file;
+	fc->src  = use_old ? diff->old_src : diff->new_src;
+
+	if (git_diff_driver_lookup(&fc->driver, fc->repo,
+		    &diff->attrsession, fc->file->path) < 0)
+		return -1;
+
+	switch (delta->status) {
+	case GIT_DELTA_ADDED:
+		has_data = !use_old; break;
+	case GIT_DELTA_DELETED:
+		has_data = use_old; break;
+	case GIT_DELTA_UNTRACKED:
+		has_data = !use_old &&
+			(diff->opts.flags & GIT_DIFF_SHOW_UNTRACKED_CONTENT) != 0;
+		break;
+	case GIT_DELTA_UNREADABLE:
+	case GIT_DELTA_MODIFIED:
+	case GIT_DELTA_COPIED:
+	case GIT_DELTA_RENAMED:
+		break;
+	default:
+		has_data = false;
+		break;
+	}
+
+	if (!has_data)
+		fc->flags |= GIT_DIFF_FLAG__NO_DATA;
+
+	return diff_file_content_init_common(fc, &diff->opts);
+}
+
+int git_diff_file_content__init_from_src(
+	git_diff_file_content *fc,
+	git_repository *repo,
+	const git_diff_options *opts,
+	const git_diff_file_content_src *src,
+	git_diff_file *as_file)
+{
+	memset(fc, 0, sizeof(*fc));
+	fc->repo = repo;
+	fc->file = as_file;
+
+	if (!src->blob && !src->buf) {
+		fc->flags |= GIT_DIFF_FLAG__NO_DATA;
+	} else {
+		fc->flags |= GIT_DIFF_FLAG__LOADED;
+		fc->file->flags |= GIT_DIFF_FLAG_VALID_ID;
+		fc->file->mode = GIT_FILEMODE_BLOB;
+
+		if (src->blob) {
+			git_blob_dup((git_blob **)&fc->blob, (git_blob *) src->blob);
+			fc->file->size = git_blob_rawsize(src->blob);
+			git_oid_cpy(&fc->file->id, git_blob_id(src->blob));
+			fc->file->id_abbrev = GIT_OID_HEXSZ;
+
+			fc->map.len  = (size_t)fc->file->size;
+			fc->map.data = (char *)git_blob_rawcontent(src->blob);
+
+			fc->flags |= GIT_DIFF_FLAG__FREE_BLOB;
+		} else {
+			fc->file->size = src->buflen;
+			git_odb_hash(&fc->file->id, src->buf, src->buflen, GIT_OBJ_BLOB);
+			fc->file->id_abbrev = GIT_OID_HEXSZ;
+
+			fc->map.len  = src->buflen;
+			fc->map.data = (char *)src->buf;
+		}
+	}
+
+	return diff_file_content_init_common(fc, opts);
+}
+
+static int diff_file_content_commit_to_str(
+	git_diff_file_content *fc, bool check_status)
+{
+	char oid[GIT_OID_HEXSZ+1];
+	git_buf content = GIT_BUF_INIT;
+	const char *status = "";
+
+	if (check_status) {
+		int error = 0;
+		git_submodule *sm = NULL;
+		unsigned int sm_status = 0;
+		const git_oid *sm_head;
+
+		if ((error = git_submodule_lookup(&sm, fc->repo, fc->file->path)) < 0) {
+			/* GIT_EEXISTS means a "submodule" that has not been git added */
+			if (error == GIT_EEXISTS) {
+				giterr_clear();
+				error = 0;
+			}
+			return error;
+		}
+
+		if ((error = git_submodule_status(&sm_status, fc->repo, fc->file->path, GIT_SUBMODULE_IGNORE_UNSPECIFIED)) < 0) {
+			git_submodule_free(sm);
+			return error;
+		}
+
+		/* update OID if we didn't have it previously */
+		if ((fc->file->flags & GIT_DIFF_FLAG_VALID_ID) == 0 &&
+			((sm_head = git_submodule_wd_id(sm)) != NULL ||
+			 (sm_head = git_submodule_head_id(sm)) != NULL))
+		{
+			git_oid_cpy(&fc->file->id, sm_head);
+			fc->file->flags |= GIT_DIFF_FLAG_VALID_ID;
+		}
+
+		if (GIT_SUBMODULE_STATUS_IS_WD_DIRTY(sm_status))
+			status = "-dirty";
+
+		git_submodule_free(sm);
+	}
+
+	git_oid_tostr(oid, sizeof(oid), &fc->file->id);
+	if (git_buf_printf(&content, "Subproject commit %s%s\n", oid, status) < 0)
+		return -1;
+
+	fc->map.len  = git_buf_len(&content);
+	fc->map.data = git_buf_detach(&content);
+	fc->flags |= GIT_DIFF_FLAG__FREE_DATA;
+
+	return 0;
+}
+
+static int diff_file_content_load_blob(
+	git_diff_file_content *fc,
+	git_diff_options *opts)
+{
+	int error = 0;
+	git_odb_object *odb_obj = NULL;
+
+	if (git_oid_iszero(&fc->file->id))
+		return 0;
+
+	if (fc->file->mode == GIT_FILEMODE_COMMIT)
+		return diff_file_content_commit_to_str(fc, false);
+
+	/* if we don't know size, try to peek at object header first */
+	if (!fc->file->size) {
+		if ((error = git_diff_file__resolve_zero_size(
+				fc->file, &odb_obj, fc->repo)) < 0)
+			return error;
+	}
+
+	if ((opts->flags & GIT_DIFF_SHOW_BINARY) == 0 &&
+		diff_file_content_binary_by_size(fc))
+		return 0;
+
+	if (odb_obj != NULL) {
+		error = git_object__from_odb_object(
+			(git_object **)&fc->blob, fc->repo, odb_obj, GIT_OBJ_BLOB);
+		git_odb_object_free(odb_obj);
+	} else {
+		error = git_blob_lookup(
+			(git_blob **)&fc->blob, fc->repo, &fc->file->id);
+	}
+
+	if (!error) {
+		fc->flags |= GIT_DIFF_FLAG__FREE_BLOB;
+		fc->map.data = (void *)git_blob_rawcontent(fc->blob);
+		fc->map.len  = (size_t)git_blob_rawsize(fc->blob);
+	}
+
+	return error;
+}
+
+static int diff_file_content_load_workdir_symlink_fake(
+	git_diff_file_content *fc, git_buf *path)
+{
+	git_buf target = GIT_BUF_INIT;
+	int error;
+
+	if ((error = git_futils_readbuffer(&target, path->ptr)) < 0)
+		return error;
+
+	fc->map.len = git_buf_len(&target);
+	fc->map.data = git_buf_detach(&target);
+	fc->flags |= GIT_DIFF_FLAG__FREE_DATA;
+
+	git_buf_free(&target);
+	return error;
+}
+
+static int diff_file_content_load_workdir_symlink(
+	git_diff_file_content *fc, git_buf *path)
+{
+	ssize_t alloc_len, read_len;
+	int symlink_supported, error;
+
+	if ((error = git_repository__cvar(
+		&symlink_supported, fc->repo, GIT_CVAR_SYMLINKS)) < 0)
+		return -1;
+
+	if (!symlink_supported)
+		return diff_file_content_load_workdir_symlink_fake(fc, path);
+
+	/* link path on disk could be UTF-16, so prepare a buffer that is
+	 * big enough to handle some UTF-8 data expansion
+	 */
+	alloc_len = (ssize_t)(fc->file->size * 2) + 1;
+
+	fc->map.data = git__calloc(alloc_len, sizeof(char));
+	GITERR_CHECK_ALLOC(fc->map.data);
+
+	fc->flags |= GIT_DIFF_FLAG__FREE_DATA;
+
+	read_len = p_readlink(git_buf_cstr(path), fc->map.data, alloc_len);
+	if (read_len < 0) {
+		giterr_set(GITERR_OS, "failed to read symlink '%s'", fc->file->path);
+		return -1;
+	}
+
+	fc->map.len = read_len;
+	return 0;
+}
+
+static int diff_file_content_load_workdir_file(
+	git_diff_file_content *fc,
+	git_buf *path,
+	git_diff_options *diff_opts)
+{
+	int error = 0;
+	git_filter_list *fl = NULL;
+	git_file fd = git_futils_open_ro(git_buf_cstr(path));
+	git_buf raw = GIT_BUF_INIT;
+
+	if (fd < 0)
+		return fd;
+
+	if (!fc->file->size &&
+		!(fc->file->size = git_futils_filesize(fd)))
+		goto cleanup;
+
+	if ((diff_opts->flags & GIT_DIFF_SHOW_BINARY) == 0 &&
+		diff_file_content_binary_by_size(fc))
+		goto cleanup;
+
+	if ((error = git_filter_list_load(
+			&fl, fc->repo, NULL, fc->file->path,
+			GIT_FILTER_TO_ODB, GIT_FILTER_ALLOW_UNSAFE)) < 0)
+		goto cleanup;
+
+	/* if there are no filters, try to mmap the file */
+	if (fl == NULL) {
+		if (!(error = git_futils_mmap_ro(
+				&fc->map, fd, 0, (size_t)fc->file->size))) {
+			fc->flags |= GIT_DIFF_FLAG__UNMAP_DATA;
+			goto cleanup;
+		}
+
+		/* if mmap failed, fall through to try readbuffer below */
+		giterr_clear();
+	}
+
+	if (!(error = git_futils_readbuffer_fd(&raw, fd, (size_t)fc->file->size))) {
+		git_buf out = GIT_BUF_INIT;
+
+		error = git_filter_list_apply_to_data(&out, fl, &raw);
+
+		if (out.ptr != raw.ptr)
+			git_buf_free(&raw);
+
+		if (!error) {
+			fc->map.len  = out.size;
+			fc->map.data = out.ptr;
+			fc->flags |= GIT_DIFF_FLAG__FREE_DATA;
+		}
+	}
+
+cleanup:
+	git_filter_list_free(fl);
+	p_close(fd);
+
+	return error;
+}
+
+static int diff_file_content_load_workdir(
+	git_diff_file_content *fc,
+	git_diff_options *diff_opts)
+{
+	int error = 0;
+	git_buf path = GIT_BUF_INIT;
+
+	if (fc->file->mode == GIT_FILEMODE_COMMIT)
+		return diff_file_content_commit_to_str(fc, true);
+
+	if (fc->file->mode == GIT_FILEMODE_TREE)
+		return 0;
+
+	if (git_buf_joinpath(
+			&path, git_repository_workdir(fc->repo), fc->file->path) < 0)
+		return -1;
+
+	if (S_ISLNK(fc->file->mode))
+		error = diff_file_content_load_workdir_symlink(fc, &path);
+	else
+		error = diff_file_content_load_workdir_file(fc, &path, diff_opts);
+
+	/* once data is loaded, update OID if we didn't have it previously */
+	if (!error && (fc->file->flags & GIT_DIFF_FLAG_VALID_ID) == 0) {
+		error = git_odb_hash(
+			&fc->file->id, fc->map.data, fc->map.len, GIT_OBJ_BLOB);
+		fc->file->flags |= GIT_DIFF_FLAG_VALID_ID;
+	}
+
+	git_buf_free(&path);
+	return error;
+}
+
+int git_diff_file_content__load(
+	git_diff_file_content *fc,
+	git_diff_options *diff_opts)
+{
+	int error = 0;
+
+	if ((fc->flags & GIT_DIFF_FLAG__LOADED) != 0)
+		return 0;
+
+	if ((fc->file->flags & GIT_DIFF_FLAG_BINARY) != 0 &&
+		(diff_opts->flags & GIT_DIFF_SHOW_BINARY) == 0)
+		return 0;
+
+	if (fc->src == GIT_ITERATOR_TYPE_WORKDIR)
+		error = diff_file_content_load_workdir(fc, diff_opts);
+	else
+		error = diff_file_content_load_blob(fc, diff_opts);
+	if (error)
+		return error;
+
+	fc->flags |= GIT_DIFF_FLAG__LOADED;
+
+	diff_file_content_binary_by_content(fc);
+
+	return 0;
+}
+
+void git_diff_file_content__unload(git_diff_file_content *fc)
+{
+	if ((fc->flags & GIT_DIFF_FLAG__LOADED) == 0)
+		return;
+
+	if (fc->flags & GIT_DIFF_FLAG__FREE_DATA) {
+		git__free(fc->map.data);
+		fc->map.data = "";
+		fc->map.len  = 0;
+		fc->flags &= ~GIT_DIFF_FLAG__FREE_DATA;
+	}
+	else if (fc->flags & GIT_DIFF_FLAG__UNMAP_DATA) {
+		git_futils_mmap_free(&fc->map);
+		fc->map.data = "";
+		fc->map.len  = 0;
+		fc->flags &= ~GIT_DIFF_FLAG__UNMAP_DATA;
+	}
+
+	if (fc->flags & GIT_DIFF_FLAG__FREE_BLOB) {
+		git_blob_free((git_blob *)fc->blob);
+		fc->blob = NULL;
+		fc->flags &= ~GIT_DIFF_FLAG__FREE_BLOB;
+	}
+
+	fc->flags &= ~GIT_DIFF_FLAG__LOADED;
+}
+
+void git_diff_file_content__clear(git_diff_file_content *fc)
+{
+	git_diff_file_content__unload(fc);
+
+	/* for now, nothing else to do */
+}

vendor/libgit2-sys/libgit2/src/diff_file.h

diff --git a/vendor/libgit2-sys/libgit2/src/diff_file.h b/vendor/libgit2-sys/libgit2/src/diff_file.h
new file mode 100644
index 0000000..5da7a7b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/diff_file.h
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_diff_file_h__
+#define INCLUDE_diff_file_h__
+
+#include "common.h"
+
+#include "diff.h"
+#include "diff_driver.h"
+#include "map.h"
+
+/* expanded information for one side of a delta */
+typedef struct {
+	git_repository *repo;
+	git_diff_file *file;
+	git_diff_driver *driver;
+	uint32_t flags;
+	uint32_t opts_flags;
+	git_off_t opts_max_size;
+	git_iterator_type_t src;
+	const git_blob *blob;
+	git_map map;
+} git_diff_file_content;
+
+extern int git_diff_file_content__init_from_diff(
+	git_diff_file_content *fc,
+	git_diff *diff,
+	git_diff_delta *delta,
+	bool use_old);
+
+typedef struct {
+	const git_blob *blob;
+	const void *buf;
+	size_t buflen;
+	const char *as_path;
+} git_diff_file_content_src;
+
+#define GIT_DIFF_FILE_CONTENT_SRC__BLOB(BLOB,PATH) { (BLOB),NULL,0,(PATH) }
+#define GIT_DIFF_FILE_CONTENT_SRC__BUF(BUF,LEN,PATH) { NULL,(BUF),(LEN),(PATH) }
+
+extern int git_diff_file_content__init_from_src(
+	git_diff_file_content *fc,
+	git_repository *repo,
+	const git_diff_options *opts,
+	const git_diff_file_content_src *src,
+	git_diff_file *as_file);
+
+/* this loads the blob/file-on-disk as needed */
+extern int git_diff_file_content__load(
+	git_diff_file_content *fc,
+	git_diff_options *diff_opts);
+
+/* this releases the blob/file-in-memory */
+extern void git_diff_file_content__unload(git_diff_file_content *fc);
+
+/* this unloads and also releases any other resources */
+extern void git_diff_file_content__clear(git_diff_file_content *fc);
+
+#endif

vendor/libgit2-sys/libgit2/src/diff_generate.c

diff --git a/vendor/libgit2-sys/libgit2/src/diff_generate.c b/vendor/libgit2-sys/libgit2/src/diff_generate.c
new file mode 100644
index 0000000..e11cbe4
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/diff_generate.c
@@ -0,0 +1,1616 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "diff_generate.h"
+
+#include "diff.h"
+#include "patch_generate.h"
+#include "fileops.h"
+#include "config.h"
+#include "attr_file.h"
+#include "filter.h"
+#include "pathspec.h"
+#include "index.h"
+#include "odb.h"
+#include "submodule.h"
+
+#define DIFF_FLAG_IS_SET(DIFF,FLAG) \
+	(((DIFF)->base.opts.flags & (FLAG)) != 0)
+#define DIFF_FLAG_ISNT_SET(DIFF,FLAG) \
+	(((DIFF)->base.opts.flags & (FLAG)) == 0)
+#define DIFF_FLAG_SET(DIFF,FLAG,VAL) (DIFF)->base.opts.flags = \
+	(VAL) ? ((DIFF)->base.opts.flags | (FLAG)) : \
+	((DIFF)->base.opts.flags & ~(FLAG))
+
+typedef struct {
+	struct git_diff base;
+
+	git_vector pathspec;
+
+	uint32_t diffcaps;
+	bool index_updated;
+} git_diff_generated;
+
+static git_diff_delta *diff_delta__alloc(
+	git_diff_generated *diff,
+	git_delta_t status,
+	const char *path)
+{
+	git_diff_delta *delta = git__calloc(1, sizeof(git_diff_delta));
+	if (!delta)
+		return NULL;
+
+	delta->old_file.path = git_pool_strdup(&diff->base.pool, path);
+	if (delta->old_file.path == NULL) {
+		git__free(delta);
+		return NULL;
+	}
+
+	delta->new_file.path = delta->old_file.path;
+
+	if (DIFF_FLAG_IS_SET(diff, GIT_DIFF_REVERSE)) {
+		switch (status) {
+		case GIT_DELTA_ADDED:   status = GIT_DELTA_DELETED; break;
+		case GIT_DELTA_DELETED: status = GIT_DELTA_ADDED; break;
+		default: break; /* leave other status values alone */
+		}
+	}
+	delta->status = status;
+
+	return delta;
+}
+
+static int diff_insert_delta(
+	git_diff_generated *diff,
+	git_diff_delta *delta,
+	const char *matched_pathspec)
+{
+	int error = 0;
+
+	if (diff->base.opts.notify_cb) {
+		error = diff->base.opts.notify_cb(
+			&diff->base, delta, matched_pathspec, diff->base.opts.payload);
+
+		if (error) {
+			git__free(delta);
+
+			if (error > 0)	/* positive value means to skip this delta */
+				return 0;
+			else			/* negative value means to cancel diff */
+				return giterr_set_after_callback_function(error, "git_diff");
+		}
+	}
+
+	if ((error = git_vector_insert(&diff->base.deltas, delta)) < 0)
+		git__free(delta);
+
+	return error;
+}
+
+static bool diff_pathspec_match(
+	const char **matched_pathspec,
+	git_diff_generated *diff,
+	const git_index_entry *entry)
+{
+	bool disable_pathspec_match =
+		DIFF_FLAG_IS_SET(diff, GIT_DIFF_DISABLE_PATHSPEC_MATCH);
+
+	/* If we're disabling fnmatch, then the iterator has already applied
+	 * the filters to the files for us and we don't have to do anything.
+	 * However, this only applies to *files* - the iterator will include
+	 * directories that we need to recurse into when not autoexpanding,
+	 * so we still need to apply the pathspec match to directories.
+	 */
+	if ((S_ISLNK(entry->mode) || S_ISREG(entry->mode)) &&
+		disable_pathspec_match) {
+		*matched_pathspec = entry->path;
+		return true;
+	}
+
+	return git_pathspec__match(
+		&diff->pathspec, entry->path, disable_pathspec_match,
+		DIFF_FLAG_IS_SET(diff, GIT_DIFF_IGNORE_CASE),
+		matched_pathspec, NULL);
+}
+
+static int diff_delta__from_one(
+	git_diff_generated *diff,
+	git_delta_t status,
+	const git_index_entry *oitem,
+	const git_index_entry *nitem)
+{
+	const git_index_entry *entry = nitem;
+	bool has_old = false;
+	git_diff_delta *delta;
+	const char *matched_pathspec;
+
+	assert((oitem != NULL) ^ (nitem != NULL));
+
+	if (oitem) {
+		entry = oitem;
+		has_old = true;
+	}
+
+	if (DIFF_FLAG_IS_SET(diff, GIT_DIFF_REVERSE))
+		has_old = !has_old;
+
+	if ((entry->flags & GIT_IDXENTRY_VALID) != 0)
+		return 0;
+
+	if (status == GIT_DELTA_IGNORED &&
+		DIFF_FLAG_ISNT_SET(diff, GIT_DIFF_INCLUDE_IGNORED))
+		return 0;
+
+	if (status == GIT_DELTA_UNTRACKED &&
+		DIFF_FLAG_ISNT_SET(diff, GIT_DIFF_INCLUDE_UNTRACKED))
+		return 0;
+
+	if (status == GIT_DELTA_UNREADABLE &&
+		DIFF_FLAG_ISNT_SET(diff, GIT_DIFF_INCLUDE_UNREADABLE))
+		return 0;
+
+	if (!diff_pathspec_match(&matched_pathspec, diff, entry))
+		return 0;
+
+	delta = diff_delta__alloc(diff, status, entry->path);
+	GITERR_CHECK_ALLOC(delta);
+
+	/* This fn is just for single-sided diffs */
+	assert(status != GIT_DELTA_MODIFIED);
+	delta->nfiles = 1;
+
+	if (has_old) {
+		delta->old_file.mode = entry->mode;
+		delta->old_file.size = entry->file_size;
+		delta->old_file.flags |= GIT_DIFF_FLAG_EXISTS;
+		git_oid_cpy(&delta->old_file.id, &entry->id);
+		delta->old_file.id_abbrev = GIT_OID_HEXSZ;
+	} else /* ADDED, IGNORED, UNTRACKED */ {
+		delta->new_file.mode = entry->mode;
+		delta->new_file.size = entry->file_size;
+		delta->new_file.flags |= GIT_DIFF_FLAG_EXISTS;
+		git_oid_cpy(&delta->new_file.id, &entry->id);
+		delta->new_file.id_abbrev = GIT_OID_HEXSZ;
+	}
+
+	delta->old_file.flags |= GIT_DIFF_FLAG_VALID_ID;
+
+	if (has_old || !git_oid_iszero(&delta->new_file.id))
+		delta->new_file.flags |= GIT_DIFF_FLAG_VALID_ID;
+
+	return diff_insert_delta(diff, delta, matched_pathspec);
+}
+
+static int diff_delta__from_two(
+	git_diff_generated *diff,
+	git_delta_t status,
+	const git_index_entry *old_entry,
+	uint32_t old_mode,
+	const git_index_entry *new_entry,
+	uint32_t new_mode,
+	const git_oid *new_id,
+	const char *matched_pathspec)
+{
+	const git_oid *old_id = &old_entry->id;
+	git_diff_delta *delta;
+	const char *canonical_path = old_entry->path;
+
+	if (status == GIT_DELTA_UNMODIFIED &&
+		DIFF_FLAG_ISNT_SET(diff, GIT_DIFF_INCLUDE_UNMODIFIED))
+		return 0;
+
+	if (!new_id)
+		new_id = &new_entry->id;
+
+	if (DIFF_FLAG_IS_SET(diff, GIT_DIFF_REVERSE)) {
+		uint32_t temp_mode = old_mode;
+		const git_index_entry *temp_entry = old_entry;
+		const git_oid *temp_id = old_id;
+
+		old_entry = new_entry;
+		new_entry = temp_entry;
+		old_mode = new_mode;
+		new_mode = temp_mode;
+		old_id = new_id;
+		new_id = temp_id;
+	}
+
+	delta = diff_delta__alloc(diff, status, canonical_path);
+	GITERR_CHECK_ALLOC(delta);
+	delta->nfiles = 2;
+
+	if (!git_index_entry_is_conflict(old_entry)) {
+		delta->old_file.size = old_entry->file_size;
+		delta->old_file.mode = old_mode;
+		git_oid_cpy(&delta->old_file.id, old_id);
+		delta->old_file.id_abbrev = GIT_OID_HEXSZ;
+		delta->old_file.flags |= GIT_DIFF_FLAG_VALID_ID |
+			GIT_DIFF_FLAG_EXISTS;
+	}
+
+	if (!git_index_entry_is_conflict(new_entry)) {
+		git_oid_cpy(&delta->new_file.id, new_id);
+		delta->new_file.id_abbrev = GIT_OID_HEXSZ;
+		delta->new_file.size = new_entry->file_size;
+		delta->new_file.mode = new_mode;
+		delta->old_file.flags |= GIT_DIFF_FLAG_EXISTS;
+		delta->new_file.flags |= GIT_DIFF_FLAG_EXISTS;
+
+		if (!git_oid_iszero(&new_entry->id))
+			delta->new_file.flags |= GIT_DIFF_FLAG_VALID_ID;
+	}
+
+	return diff_insert_delta(diff, delta, matched_pathspec);
+}
+
+static git_diff_delta *diff_delta__last_for_item(
+	git_diff_generated *diff,
+	const git_index_entry *item)
+{
+	git_diff_delta *delta = git_vector_last(&diff->base.deltas);
+	if (!delta)
+		return NULL;
+
+	switch (delta->status) {
+	case GIT_DELTA_UNMODIFIED:
+	case GIT_DELTA_DELETED:
+		if (git_oid__cmp(&delta->old_file.id, &item->id) == 0)
+			return delta;
+		break;
+	case GIT_DELTA_ADDED:
+		if (git_oid__cmp(&delta->new_file.id, &item->id) == 0)
+			return delta;
+		break;
+	case GIT_DELTA_UNREADABLE:
+	case GIT_DELTA_UNTRACKED:
+		if (diff->base.strcomp(delta->new_file.path, item->path) == 0 &&
+			git_oid__cmp(&delta->new_file.id, &item->id) == 0)
+			return delta;
+		break;
+	case GIT_DELTA_MODIFIED:
+		if (git_oid__cmp(&delta->old_file.id, &item->id) == 0 ||
+			git_oid__cmp(&delta->new_file.id, &item->id) == 0)
+			return delta;
+		break;
+	default:
+		break;
+	}
+
+	return NULL;
+}
+
+static char *diff_strdup_prefix(git_pool *pool, const char *prefix)
+{
+	size_t len = strlen(prefix);
+
+	/* append '/' at end if needed */
+	if (len > 0 && prefix[len - 1] != '/')
+		return git_pool_strcat(pool, prefix, "/");
+	else
+		return git_pool_strndup(pool, prefix, len + 1);
+}
+
+GIT_INLINE(const char *) diff_delta__i2w_path(const git_diff_delta *delta)
+{
+	return delta->old_file.path ?
+		delta->old_file.path : delta->new_file.path;
+}
+
+int git_diff_delta__i2w_cmp(const void *a, const void *b)
+{
+	const git_diff_delta *da = a, *db = b;
+	int val = strcmp(diff_delta__i2w_path(da), diff_delta__i2w_path(db));
+	return val ? val : ((int)da->status - (int)db->status);
+}
+
+int git_diff_delta__i2w_casecmp(const void *a, const void *b)
+{
+	const git_diff_delta *da = a, *db = b;
+	int val = strcasecmp(diff_delta__i2w_path(da), diff_delta__i2w_path(db));
+	return val ? val : ((int)da->status - (int)db->status);
+}
+
+bool git_diff_delta__should_skip(
+	const git_diff_options *opts, const git_diff_delta *delta)
+{
+	uint32_t flags = opts ? opts->flags : 0;
+
+	if (delta->status == GIT_DELTA_UNMODIFIED &&
+		(flags & GIT_DIFF_INCLUDE_UNMODIFIED) == 0)
+		return true;
+
+	if (delta->status == GIT_DELTA_IGNORED &&
+		(flags & GIT_DIFF_INCLUDE_IGNORED) == 0)
+		return true;
+
+	if (delta->status == GIT_DELTA_UNTRACKED &&
+		(flags & GIT_DIFF_INCLUDE_UNTRACKED) == 0)
+		return true;
+
+	if (delta->status == GIT_DELTA_UNREADABLE &&
+		(flags & GIT_DIFF_INCLUDE_UNREADABLE) == 0)
+		return true;
+
+	return false;
+}
+
+
+static const char *diff_mnemonic_prefix(
+	git_iterator_type_t type, bool left_side)
+{
+	const char *pfx = "";
+
+	switch (type) {
+	case GIT_ITERATOR_TYPE_EMPTY:   pfx = "c"; break;
+	case GIT_ITERATOR_TYPE_TREE:    pfx = "c"; break;
+	case GIT_ITERATOR_TYPE_INDEX:   pfx = "i"; break;
+	case GIT_ITERATOR_TYPE_WORKDIR: pfx = "w"; break;
+	case GIT_ITERATOR_TYPE_FS:      pfx = left_side ? "1" : "2"; break;
+	default: break;
+	}
+
+	/* note: without a deeper look at pathspecs, there is no easy way
+	 * to get the (o)bject / (w)ork tree mnemonics working...
+	 */
+
+	return pfx;
+}
+
+void git_diff__set_ignore_case(git_diff *diff, bool ignore_case)
+{
+	if (!ignore_case) {
+		diff->opts.flags &= ~GIT_DIFF_IGNORE_CASE;
+
+		diff->strcomp    = git__strcmp;
+		diff->strncomp   = git__strncmp;
+		diff->pfxcomp    = git__prefixcmp;
+		diff->entrycomp  = git_diff__entry_cmp;
+
+		git_vector_set_cmp(&diff->deltas, git_diff_delta__cmp);
+	} else {
+		diff->opts.flags |= GIT_DIFF_IGNORE_CASE;
+
+		diff->strcomp    = git__strcasecmp;
+		diff->strncomp   = git__strncasecmp;
+		diff->pfxcomp    = git__prefixcmp_icase;
+		diff->entrycomp  = git_diff__entry_icmp;
+
+		git_vector_set_cmp(&diff->deltas, git_diff_delta__casecmp);
+	}
+
+	git_vector_sort(&diff->deltas);
+}
+
+static void diff_generated_free(git_diff *d)
+{
+	git_diff_generated *diff = (git_diff_generated *)d;
+
+	git_attr_session__free(&diff->base.attrsession);
+	git_vector_free_deep(&diff->base.deltas);
+
+	git_pathspec__vfree(&diff->pathspec);
+	git_pool_clear(&diff->base.pool);
+
+	git__memzero(diff, sizeof(*diff));
+	git__free(diff);
+}
+
+static git_diff_generated *diff_generated_alloc(
+	git_repository *repo,
+	git_iterator *old_iter,
+	git_iterator *new_iter)
+{
+	git_diff_generated *diff;
+	git_diff_options dflt = GIT_DIFF_OPTIONS_INIT;
+
+	assert(repo && old_iter && new_iter);
+
+	if ((diff = git__calloc(1, sizeof(git_diff_generated))) == NULL)
+		return NULL;
+
+	GIT_REFCOUNT_INC(&diff->base);
+	diff->base.type = GIT_DIFF_TYPE_GENERATED;
+	diff->base.repo = repo;
+	diff->base.old_src = old_iter->type;
+	diff->base.new_src = new_iter->type;
+	diff->base.patch_fn = git_patch_generated_from_diff;
+	diff->base.free_fn = diff_generated_free;
+	git_attr_session__init(&diff->base.attrsession, repo);
+	memcpy(&diff->base.opts, &dflt, sizeof(git_diff_options));
+
+	git_pool_init(&diff->base.pool, 1);
+
+	if (git_vector_init(&diff->base.deltas, 0, git_diff_delta__cmp) < 0) {
+		git_diff_free(&diff->base);
+		return NULL;
+	}
+
+	/* Use case-insensitive compare if either iterator has
+	 * the ignore_case bit set */
+	git_diff__set_ignore_case(
+		&diff->base,
+		git_iterator_ignore_case(old_iter) ||
+		git_iterator_ignore_case(new_iter));
+
+	return diff;
+}
+
+static int diff_generated_apply_options(
+	git_diff_generated *diff,
+	const git_diff_options *opts)
+{
+	git_config *cfg = NULL;
+	git_repository *repo = diff->base.repo;
+	git_pool *pool = &diff->base.pool;
+	int val;
+
+	if (opts) {
+		/* copy user options (except case sensitivity info from iterators) */
+		bool icase = DIFF_FLAG_IS_SET(diff, GIT_DIFF_IGNORE_CASE);
+		memcpy(&diff->base.opts, opts, sizeof(diff->base.opts));
+		DIFF_FLAG_SET(diff, GIT_DIFF_IGNORE_CASE, icase);
+
+		/* initialize pathspec from options */
+		if (git_pathspec__vinit(&diff->pathspec, &opts->pathspec, pool) < 0)
+			return -1;
+	}
+
+	/* flag INCLUDE_TYPECHANGE_TREES implies INCLUDE_TYPECHANGE */
+	if (DIFF_FLAG_IS_SET(diff, GIT_DIFF_INCLUDE_TYPECHANGE_TREES))
+		diff->base.opts.flags |= GIT_DIFF_INCLUDE_TYPECHANGE;
+
+	/* flag INCLUDE_UNTRACKED_CONTENT implies INCLUDE_UNTRACKED */
+	if (DIFF_FLAG_IS_SET(diff, GIT_DIFF_SHOW_UNTRACKED_CONTENT))
+		diff->base.opts.flags |= GIT_DIFF_INCLUDE_UNTRACKED;
+
+	/* load config values that affect diff behavior */
+	if ((val = git_repository_config_snapshot(&cfg, repo)) < 0)
+		return val;
+
+	if (!git_config__cvar(&val, cfg, GIT_CVAR_SYMLINKS) && val)
+		diff->diffcaps |= GIT_DIFFCAPS_HAS_SYMLINKS;
+
+	if (!git_config__cvar(&val, cfg, GIT_CVAR_IGNORESTAT) && val)
+		diff->diffcaps |= GIT_DIFFCAPS_IGNORE_STAT;
+
+	if ((diff->base.opts.flags & GIT_DIFF_IGNORE_FILEMODE) == 0 &&
+		!git_config__cvar(&val, cfg, GIT_CVAR_FILEMODE) && val)
+		diff->diffcaps |= GIT_DIFFCAPS_TRUST_MODE_BITS;
+
+	if (!git_config__cvar(&val, cfg, GIT_CVAR_TRUSTCTIME) && val)
+		diff->diffcaps |= GIT_DIFFCAPS_TRUST_CTIME;
+
+	/* Don't set GIT_DIFFCAPS_USE_DEV - compile time option in core git */
+
+	/* If not given explicit `opts`, check `diff.xyz` configs */
+	if (!opts) {
+		int context = git_config__get_int_force(cfg, "diff.context", 3);
+		diff->base.opts.context_lines = context >= 0 ? (uint32_t)context : 3;
+
+		/* add other defaults here */
+	}
+
+	/* Reverse src info if diff is reversed */
+	if (DIFF_FLAG_IS_SET(diff, GIT_DIFF_REVERSE)) {
+		git_iterator_type_t tmp_src = diff->base.old_src;
+		diff->base.old_src = diff->base.new_src;
+		diff->base.new_src = tmp_src;
+	}
+
+	/* Unset UPDATE_INDEX unless diffing workdir and index */
+	if (DIFF_FLAG_IS_SET(diff, GIT_DIFF_UPDATE_INDEX) &&
+		(!(diff->base.old_src == GIT_ITERATOR_TYPE_WORKDIR ||
+		   diff->base.new_src == GIT_ITERATOR_TYPE_WORKDIR) ||
+		 !(diff->base.old_src == GIT_ITERATOR_TYPE_INDEX ||
+		   diff->base.new_src == GIT_ITERATOR_TYPE_INDEX)))
+		diff->base.opts.flags &= ~GIT_DIFF_UPDATE_INDEX;
+
+	/* if ignore_submodules not explicitly set, check diff config */
+	if (diff->base.opts.ignore_submodules <= 0) {
+		 git_config_entry *entry;
+		git_config__lookup_entry(&entry, cfg, "diff.ignoresubmodules", true);
+
+		if (entry && git_submodule_parse_ignore(
+				&diff->base.opts.ignore_submodules, entry->value) < 0)
+			giterr_clear();
+		git_config_entry_free(entry);
+	}
+
+	/* if either prefix is not set, figure out appropriate value */
+	if (!diff->base.opts.old_prefix || !diff->base.opts.new_prefix) {
+		const char *use_old = DIFF_OLD_PREFIX_DEFAULT;
+		const char *use_new = DIFF_NEW_PREFIX_DEFAULT;
+
+		if (git_config__get_bool_force(cfg, "diff.noprefix", 0))
+			use_old = use_new = "";
+		else if (git_config__get_bool_force(cfg, "diff.mnemonicprefix", 0)) {
+			use_old = diff_mnemonic_prefix(diff->base.old_src, true);
+			use_new = diff_mnemonic_prefix(diff->base.new_src, false);
+		}
+
+		if (!diff->base.opts.old_prefix)
+			diff->base.opts.old_prefix = use_old;
+		if (!diff->base.opts.new_prefix)
+			diff->base.opts.new_prefix = use_new;
+	}
+
+	/* strdup prefix from pool so we're not dependent on external data */
+	diff->base.opts.old_prefix = diff_strdup_prefix(pool, diff->base.opts.old_prefix);
+	diff->base.opts.new_prefix = diff_strdup_prefix(pool, diff->base.opts.new_prefix);
+
+	if (DIFF_FLAG_IS_SET(diff, GIT_DIFF_REVERSE)) {
+		const char *tmp_prefix = diff->base.opts.old_prefix;
+		diff->base.opts.old_prefix  = diff->base.opts.new_prefix;
+		diff->base.opts.new_prefix  = tmp_prefix;
+	}
+
+	git_config_free(cfg);
+
+	/* check strdup results for error */
+	return (!diff->base.opts.old_prefix || !diff->base.opts.new_prefix) ? -1 : 0;
+}
+
+int git_diff__oid_for_file(
+	git_oid *out,
+	git_diff *diff,
+	const char *path,
+	uint16_t mode,
+	git_off_t size)
+{
+	git_index_entry entry;
+
+	memset(&entry, 0, sizeof(entry));
+	entry.mode = mode;
+	entry.file_size = size;
+	entry.path = (char *)path;
+
+	return git_diff__oid_for_entry(out, diff, &entry, mode, NULL);
+}
+
+int git_diff__oid_for_entry(
+	git_oid *out,
+	git_diff *d,
+	const git_index_entry *src,
+	uint16_t mode,
+	const git_oid *update_match)
+{
+	git_diff_generated *diff;
+	git_buf full_path = GIT_BUF_INIT;
+	git_index_entry entry = *src;
+	git_filter_list *fl = NULL;
+	int error = 0;
+
+	assert(d->type == GIT_DIFF_TYPE_GENERATED);
+	diff = (git_diff_generated *)d;
+
+	memset(out, 0, sizeof(*out));
+
+	if (git_buf_joinpath(&full_path,
+		git_repository_workdir(diff->base.repo), entry.path) < 0)
+		return -1;
+
+	if (!mode) {
+		struct stat st;
+
+		diff->base.perf.stat_calls++;
+
+		if (p_stat(full_path.ptr, &st) < 0) {
+			error = git_path_set_error(errno, entry.path, "stat");
+			git_buf_free(&full_path);
+			return error;
+		}
+
+		git_index_entry__init_from_stat(&entry,
+			&st, (diff->diffcaps & GIT_DIFFCAPS_TRUST_MODE_BITS) != 0);
+	}
+
+	/* calculate OID for file if possible */
+	if (S_ISGITLINK(mode)) {
+		git_submodule *sm;
+
+		if (!git_submodule_lookup(&sm, diff->base.repo, entry.path)) {
+			const git_oid *sm_oid = git_submodule_wd_id(sm);
+			if (sm_oid)
+				git_oid_cpy(out, sm_oid);
+			git_submodule_free(sm);
+		} else {
+			/* if submodule lookup failed probably just in an intermediate
+			 * state where some init hasn't happened, so ignore the error
+			 */
+			giterr_clear();
+		}
+	} else if (S_ISLNK(mode)) {
+		error = git_odb__hashlink(out, full_path.ptr);
+		diff->base.perf.oid_calculations++;
+	} else if (!git__is_sizet(entry.file_size)) {
+		giterr_set(GITERR_OS, "file size overflow (for 32-bits) on '%s'",
+			entry.path);
+		error = -1;
+	} else if (!(error = git_filter_list_load(&fl,
+		diff->base.repo, NULL, entry.path,
+		GIT_FILTER_TO_ODB, GIT_FILTER_ALLOW_UNSAFE)))
+	{
+		int fd = git_futils_open_ro(full_path.ptr);
+		if (fd < 0)
+			error = fd;
+		else {
+			error = git_odb__hashfd_filtered(
+				out, fd, (size_t)entry.file_size, GIT_OBJ_BLOB, fl);
+			p_close(fd);
+			diff->base.perf.oid_calculations++;
+		}
+
+		git_filter_list_free(fl);
+	}
+
+	/* update index for entry if requested */
+	if (!error && update_match && git_oid_equal(out, update_match)) {
+		git_index *idx;
+		git_index_entry updated_entry;
+
+		memcpy(&updated_entry, &entry, sizeof(git_index_entry));
+		updated_entry.mode = mode;
+		git_oid_cpy(&updated_entry.id, out);
+
+		if (!(error = git_repository_index__weakptr(&idx,
+			diff->base.repo))) {
+			error = git_index_add(idx, &updated_entry);
+			diff->index_updated = true;
+		}
+ 	}
+
+	git_buf_free(&full_path);
+	return error;
+}
+
+typedef struct {
+	git_repository *repo;
+	git_iterator *old_iter;
+	git_iterator *new_iter;
+	const git_index_entry *oitem;
+	const git_index_entry *nitem;
+} diff_in_progress;
+
+#define MODE_BITS_MASK 0000777
+
+static int maybe_modified_submodule(
+	git_delta_t *status,
+	git_oid *found_oid,
+	git_diff_generated *diff,
+	diff_in_progress *info)
+{
+	int error = 0;
+	git_submodule *sub;
+	unsigned int sm_status = 0;
+	git_submodule_ignore_t ign = diff->base.opts.ignore_submodules;
+
+	*status = GIT_DELTA_UNMODIFIED;
+
+	if (DIFF_FLAG_IS_SET(diff, GIT_DIFF_IGNORE_SUBMODULES) ||
+		ign == GIT_SUBMODULE_IGNORE_ALL)
+		return 0;
+
+	if ((error = git_submodule_lookup(
+			&sub, diff->base.repo, info->nitem->path)) < 0) {
+
+		/* GIT_EEXISTS means dir with .git in it was found - ignore it */
+		if (error == GIT_EEXISTS) {
+			giterr_clear();
+			error = 0;
+		}
+		return error;
+	}
+
+	if (ign <= 0 && git_submodule_ignore(sub) == GIT_SUBMODULE_IGNORE_ALL)
+		/* ignore it */;
+	else if ((error = git_submodule__status(
+			&sm_status, NULL, NULL, found_oid, sub, ign)) < 0)
+		/* return error below */;
+
+	/* check IS_WD_UNMODIFIED because this case is only used
+	 * when the new side of the diff is the working directory
+	 */
+	else if (!GIT_SUBMODULE_STATUS_IS_WD_UNMODIFIED(sm_status))
+		*status = GIT_DELTA_MODIFIED;
+
+	/* now that we have a HEAD OID, check if HEAD moved */
+	else if ((sm_status & GIT_SUBMODULE_STATUS_IN_WD) != 0 &&
+		!git_oid_equal(&info->oitem->id, found_oid))
+		*status = GIT_DELTA_MODIFIED;
+
+	git_submodule_free(sub);
+	return error;
+}
+
+static int maybe_modified(
+	git_diff_generated *diff,
+	diff_in_progress *info)
+{
+	git_oid noid;
+	git_delta_t status = GIT_DELTA_MODIFIED;
+	const git_index_entry *oitem = info->oitem;
+	const git_index_entry *nitem = info->nitem;
+	unsigned int omode = oitem->mode;
+	unsigned int nmode = nitem->mode;
+	bool new_is_workdir = (info->new_iter->type == GIT_ITERATOR_TYPE_WORKDIR);
+	bool modified_uncertain = false;
+	const char *matched_pathspec;
+	int error = 0;
+
+	if (!diff_pathspec_match(&matched_pathspec, diff, oitem))
+		return 0;
+
+	memset(&noid, 0, sizeof(noid));
+
+	/* on platforms with no symlinks, preserve mode of existing symlinks */
+	if (S_ISLNK(omode) && S_ISREG(nmode) && new_is_workdir &&
+		!(diff->diffcaps & GIT_DIFFCAPS_HAS_SYMLINKS))
+		nmode = omode;
+
+	/* on platforms with no execmode, just preserve old mode */
+	if (!(diff->diffcaps & GIT_DIFFCAPS_TRUST_MODE_BITS) &&
+		(nmode & MODE_BITS_MASK) != (omode & MODE_BITS_MASK) &&
+		new_is_workdir)
+		nmode = (nmode & ~MODE_BITS_MASK) | (omode & MODE_BITS_MASK);
+
+	/* if one side is a conflict, mark the whole delta as conflicted */
+	if (git_index_entry_is_conflict(oitem) ||
+			git_index_entry_is_conflict(nitem)) {
+		status = GIT_DELTA_CONFLICTED;
+
+	/* support "assume unchanged" (poorly, b/c we still stat everything) */
+	} else if ((oitem->flags & GIT_IDXENTRY_VALID) != 0) {
+		status = GIT_DELTA_UNMODIFIED;
+
+	/* support "skip worktree" index bit */
+	} else if ((oitem->flags_extended & GIT_IDXENTRY_SKIP_WORKTREE) != 0) {
+		status = GIT_DELTA_UNMODIFIED;
+
+	/* if basic type of file changed, then split into delete and add */
+	} else if (GIT_MODE_TYPE(omode) != GIT_MODE_TYPE(nmode)) {
+		if (DIFF_FLAG_IS_SET(diff, GIT_DIFF_INCLUDE_TYPECHANGE)) {
+			status = GIT_DELTA_TYPECHANGE;
+		}
+
+		else if (nmode == GIT_FILEMODE_UNREADABLE) {
+			if (!(error = diff_delta__from_one(diff, GIT_DELTA_DELETED, oitem, NULL)))
+				error = diff_delta__from_one(diff, GIT_DELTA_UNREADABLE, NULL, nitem);
+			return error;
+		}
+
+		else {
+			if (!(error = diff_delta__from_one(diff, GIT_DELTA_DELETED, oitem, NULL)))
+				error = diff_delta__from_one(diff, GIT_DELTA_ADDED, NULL, nitem);
+			return error;
+		}
+
+	/* if oids and modes match (and are valid), then file is unmodified */
+	} else if (git_oid_equal(&oitem->id, &nitem->id) &&
+			 omode == nmode &&
+			 !git_oid_iszero(&oitem->id)) {
+		status = GIT_DELTA_UNMODIFIED;
+
+	/* if we have an unknown OID and a workdir iterator, then check some
+	 * circumstances that can accelerate things or need special handling
+	 */
+	} else if (git_oid_iszero(&nitem->id) && new_is_workdir) {
+		bool use_ctime =
+			((diff->diffcaps & GIT_DIFFCAPS_TRUST_CTIME) != 0);
+		git_index *index = git_iterator_index(info->new_iter);
+
+		status = GIT_DELTA_UNMODIFIED;
+
+		if (S_ISGITLINK(nmode)) {
+			if ((error = maybe_modified_submodule(&status, &noid, diff, info)) < 0)
+				return error;
+		}
+
+		/* if the stat data looks different, then mark modified - this just
+		 * means that the OID will be recalculated below to confirm change
+		 */
+		else if (omode != nmode || oitem->file_size != nitem->file_size) {
+			status = GIT_DELTA_MODIFIED;
+			modified_uncertain =
+				(oitem->file_size <= 0 && nitem->file_size > 0);
+		}
+		else if (!git_index_time_eq(&oitem->mtime, &nitem->mtime) ||
+			(use_ctime && !git_index_time_eq(&oitem->ctime, &nitem->ctime)) ||
+			oitem->ino != nitem->ino ||
+			oitem->uid != nitem->uid ||
+			oitem->gid != nitem->gid ||
+			git_index_entry_newer_than_index(nitem, index))
+		{
+			status = GIT_DELTA_MODIFIED;
+			modified_uncertain = true;
+		}
+
+	/* if mode is GITLINK and submodules are ignored, then skip */
+	} else if (S_ISGITLINK(nmode) &&
+			 DIFF_FLAG_IS_SET(diff, GIT_DIFF_IGNORE_SUBMODULES)) {
+		status = GIT_DELTA_UNMODIFIED;
+	}
+
+	/* if we got here and decided that the files are modified, but we
+	 * haven't calculated the OID of the new item, then calculate it now
+	 */
+	if (modified_uncertain && git_oid_iszero(&nitem->id)) {
+		const git_oid *update_check =
+			DIFF_FLAG_IS_SET(diff, GIT_DIFF_UPDATE_INDEX) && omode == nmode ?
+			&oitem->id : NULL;
+
+		if ((error = git_diff__oid_for_entry(
+				&noid, &diff->base, nitem, nmode, update_check)) < 0)
+			return error;
+
+		/* if oid matches, then mark unmodified (except submodules, where
+		 * the filesystem content may be modified even if the oid still
+		 * matches between the index and the workdir HEAD)
+		 */
+		if (omode == nmode && !S_ISGITLINK(omode) &&
+			git_oid_equal(&oitem->id, &noid))
+			status = GIT_DELTA_UNMODIFIED;
+	}
+
+	/* If we want case changes, then break this into a delete of the old
+	 * and an add of the new so that consumers can act accordingly (eg,
+	 * checkout will update the case on disk.)
+	 */
+	if (DIFF_FLAG_IS_SET(diff, GIT_DIFF_IGNORE_CASE) &&
+		DIFF_FLAG_IS_SET(diff, GIT_DIFF_INCLUDE_CASECHANGE) &&
+		strcmp(oitem->path, nitem->path) != 0) {
+
+		if (!(error = diff_delta__from_one(diff, GIT_DELTA_DELETED, oitem, NULL)))
+			error = diff_delta__from_one(diff, GIT_DELTA_ADDED, NULL, nitem);
+
+		return error;
+	}
+
+	return diff_delta__from_two(
+		diff, status, oitem, omode, nitem, nmode,
+		git_oid_iszero(&noid) ? NULL : &noid, matched_pathspec);
+}
+
+static bool entry_is_prefixed(
+	git_diff_generated *diff,
+	const git_index_entry *item,
+	const git_index_entry *prefix_item)
+{
+	size_t pathlen;
+
+	if (!item || diff->base.pfxcomp(item->path, prefix_item->path) != 0)
+		return false;
+
+	pathlen = strlen(prefix_item->path);
+
+	return (prefix_item->path[pathlen - 1] == '/' ||
+			item->path[pathlen] == '\0' ||
+			item->path[pathlen] == '/');
+}
+
+static int iterator_current(
+	const git_index_entry **entry,
+	git_iterator *iterator)
+{
+	int error;
+
+	if ((error = git_iterator_current(entry, iterator)) == GIT_ITEROVER) {
+		*entry = NULL;
+		error = 0;
+	}
+
+	return error;
+}
+
+static int iterator_advance(
+	const git_index_entry **entry,
+	git_iterator *iterator)
+{
+	const git_index_entry *prev_entry = *entry;
+	int cmp, error;
+
+	/* if we're looking for conflicts, we only want to report
+	 * one conflict for each file, instead of all three sides.
+	 * so if this entry is a conflict for this file, and the
+	 * previous one was a conflict for the same file, skip it.
+	 */
+	while ((error = git_iterator_advance(entry, iterator)) == 0) {
+		if (!(iterator->flags & GIT_ITERATOR_INCLUDE_CONFLICTS) ||
+			!git_index_entry_is_conflict(prev_entry) ||
+			!git_index_entry_is_conflict(*entry))
+			break;
+
+		cmp = (iterator->flags & GIT_ITERATOR_IGNORE_CASE) ?
+			strcasecmp(prev_entry->path, (*entry)->path) :
+			strcmp(prev_entry->path, (*entry)->path);
+
+		if (cmp)
+			break;
+	}
+
+	if (error == GIT_ITEROVER) {
+		*entry = NULL;
+		error = 0;
+	}
+
+	return error;
+}
+
+static int iterator_advance_into(
+	const git_index_entry **entry,
+	git_iterator *iterator)
+{
+	int error;
+
+	if ((error = git_iterator_advance_into(entry, iterator)) == GIT_ITEROVER) {
+		*entry = NULL;
+		error = 0;
+	}
+
+	return error;
+}
+
+static int iterator_advance_over(
+	const git_index_entry **entry,
+	git_iterator_status_t *status,
+	git_iterator *iterator)
+{
+	int error = git_iterator_advance_over(entry, status, iterator);
+
+	if (error == GIT_ITEROVER) {
+		*entry = NULL;
+		error = 0;
+	}
+
+	return error;
+}
+
+static int handle_unmatched_new_item(
+	git_diff_generated *diff, diff_in_progress *info)
+{
+	int error = 0;
+	const git_index_entry *nitem = info->nitem;
+	git_delta_t delta_type = GIT_DELTA_UNTRACKED;
+	bool contains_oitem;
+
+	/* check if this is a prefix of the other side */
+	contains_oitem = entry_is_prefixed(diff, info->oitem, nitem);
+
+	/* update delta_type if this item is conflicted */
+	if (git_index_entry_is_conflict(nitem))
+		delta_type = GIT_DELTA_CONFLICTED;
+
+	/* update delta_type if this item is ignored */
+	else if (git_iterator_current_is_ignored(info->new_iter))
+		delta_type = GIT_DELTA_IGNORED;
+
+	if (nitem->mode == GIT_FILEMODE_TREE) {
+		bool recurse_into_dir = contains_oitem;
+
+		/* check if user requests recursion into this type of dir */
+		recurse_into_dir = contains_oitem ||
+			(delta_type == GIT_DELTA_UNTRACKED &&
+			 DIFF_FLAG_IS_SET(diff, GIT_DIFF_RECURSE_UNTRACKED_DIRS)) ||
+			(delta_type == GIT_DELTA_IGNORED &&
+			 DIFF_FLAG_IS_SET(diff, GIT_DIFF_RECURSE_IGNORED_DIRS));
+
+		/* do not advance into directories that contain a .git file */
+		if (recurse_into_dir && !contains_oitem) {
+			git_buf *full = NULL;
+			if (git_iterator_current_workdir_path(&full, info->new_iter) < 0)
+				return -1;
+			if (full && git_path_contains(full, DOT_GIT)) {
+				/* TODO: warning if not a valid git repository */
+				recurse_into_dir = false;
+			}
+		}
+
+		/* still have to look into untracked directories to match core git -
+		 * with no untracked files, directory is treated as ignored
+		 */
+		if (!recurse_into_dir &&
+			delta_type == GIT_DELTA_UNTRACKED &&
+			DIFF_FLAG_ISNT_SET(diff, GIT_DIFF_ENABLE_FAST_UNTRACKED_DIRS))
+		{
+			git_diff_delta *last;
+			git_iterator_status_t untracked_state;
+
+			/* attempt to insert record for this directory */
+			if ((error = diff_delta__from_one(diff, delta_type, NULL, nitem)) != 0)
+				return error;
+
+			/* if delta wasn't created (because of rules), just skip ahead */
+			last = diff_delta__last_for_item(diff, nitem);
+			if (!last)
+				return iterator_advance(&info->nitem, info->new_iter);
+
+			/* iterate into dir looking for an actual untracked file */
+			if ((error = iterator_advance_over(
+					&info->nitem, &untracked_state, info->new_iter)) < 0)
+				return error;
+
+			/* if we found nothing that matched our pathlist filter, exclude */
+			if (untracked_state == GIT_ITERATOR_STATUS_FILTERED) {
+				git_vector_pop(&diff->base.deltas);
+				git__free(last);
+			}
+
+			/* if we found nothing or just ignored items, update the record */
+			if (untracked_state == GIT_ITERATOR_STATUS_IGNORED ||
+				untracked_state == GIT_ITERATOR_STATUS_EMPTY) {
+				last->status = GIT_DELTA_IGNORED;
+
+				/* remove the record if we don't want ignored records */
+				if (DIFF_FLAG_ISNT_SET(diff, GIT_DIFF_INCLUDE_IGNORED)) {
+					git_vector_pop(&diff->base.deltas);
+					git__free(last);
+				}
+			}
+
+			return 0;
+		}
+
+		/* try to advance into directory if necessary */
+		if (recurse_into_dir) {
+			error = iterator_advance_into(&info->nitem, info->new_iter);
+
+			/* if directory is empty, can't advance into it, so skip it */
+			if (error == GIT_ENOTFOUND) {
+				giterr_clear();
+				error = iterator_advance(&info->nitem, info->new_iter);
+			}
+
+			return error;
+		}
+	}
+
+	else if (delta_type == GIT_DELTA_IGNORED &&
+		DIFF_FLAG_ISNT_SET(diff, GIT_DIFF_RECURSE_IGNORED_DIRS) &&
+		git_iterator_current_tree_is_ignored(info->new_iter))
+		/* item contained in ignored directory, so skip over it */
+		return iterator_advance(&info->nitem, info->new_iter);
+
+	else if (info->new_iter->type != GIT_ITERATOR_TYPE_WORKDIR) {
+		if (delta_type != GIT_DELTA_CONFLICTED)
+			delta_type = GIT_DELTA_ADDED;
+	}
+
+	else if (nitem->mode == GIT_FILEMODE_COMMIT) {
+		/* ignore things that are not actual submodules */
+		if (git_submodule_lookup(NULL, info->repo, nitem->path) != 0) {
+			giterr_clear();
+			delta_type = GIT_DELTA_IGNORED;
+
+			/* if this contains a tracked item, treat as normal TREE */
+			if (contains_oitem) {
+				error = iterator_advance_into(&info->nitem, info->new_iter);
+				if (error != GIT_ENOTFOUND)
+					return error;
+
+				giterr_clear();
+				return iterator_advance(&info->nitem, info->new_iter);
+			}
+		}
+	}
+
+	else if (nitem->mode == GIT_FILEMODE_UNREADABLE) {
+		if (DIFF_FLAG_IS_SET(diff, GIT_DIFF_INCLUDE_UNREADABLE_AS_UNTRACKED))
+			delta_type = GIT_DELTA_UNTRACKED;
+		else
+			delta_type = GIT_DELTA_UNREADABLE;
+	}
+
+	/* Actually create the record for this item if necessary */
+	if ((error = diff_delta__from_one(diff, delta_type, NULL, nitem)) != 0)
+		return error;
+
+	/* If user requested TYPECHANGE records, then check for that instead of
+	 * just generating an ADDED/UNTRACKED record
+	 */
+	if (delta_type != GIT_DELTA_IGNORED &&
+		DIFF_FLAG_IS_SET(diff, GIT_DIFF_INCLUDE_TYPECHANGE_TREES) &&
+		contains_oitem)
+	{
+		/* this entry was prefixed with a tree - make TYPECHANGE */
+		git_diff_delta *last = diff_delta__last_for_item(diff, nitem);
+		if (last) {
+			last->status = GIT_DELTA_TYPECHANGE;
+			last->old_file.mode = GIT_FILEMODE_TREE;
+		}
+	}
+
+	return iterator_advance(&info->nitem, info->new_iter);
+}
+
+static int handle_unmatched_old_item(
+	git_diff_generated *diff, diff_in_progress *info)
+{
+	git_delta_t delta_type = GIT_DELTA_DELETED;
+	int error;
+
+	/* update delta_type if this item is conflicted */
+	if (git_index_entry_is_conflict(info->oitem))
+		delta_type = GIT_DELTA_CONFLICTED;
+
+	if ((error = diff_delta__from_one(diff, delta_type, info->oitem, NULL)) < 0)
+		return error;
+
+	/* if we are generating TYPECHANGE records then check for that
+	 * instead of just generating a DELETE record
+	 */
+	if (DIFF_FLAG_IS_SET(diff, GIT_DIFF_INCLUDE_TYPECHANGE_TREES) &&
+		entry_is_prefixed(diff, info->nitem, info->oitem))
+	{
+		/* this entry has become a tree! convert to TYPECHANGE */
+		git_diff_delta *last = diff_delta__last_for_item(diff, info->oitem);
+		if (last) {
+			last->status = GIT_DELTA_TYPECHANGE;
+			last->new_file.mode = GIT_FILEMODE_TREE;
+		}
+
+		/* If new_iter is a workdir iterator, then this situation
+		 * will certainly be followed by a series of untracked items.
+		 * Unless RECURSE_UNTRACKED_DIRS is set, skip over them...
+		 */
+		if (S_ISDIR(info->nitem->mode) &&
+			DIFF_FLAG_ISNT_SET(diff, GIT_DIFF_RECURSE_UNTRACKED_DIRS))
+			return iterator_advance(&info->nitem, info->new_iter);
+	}
+
+	return iterator_advance(&info->oitem, info->old_iter);
+}
+
+static int handle_matched_item(
+	git_diff_generated *diff, diff_in_progress *info)
+{
+	int error = 0;
+
+	if ((error = maybe_modified(diff, info)) < 0)
+		return error;
+
+	if (!(error = iterator_advance(&info->oitem, info->old_iter)))
+		error = iterator_advance(&info->nitem, info->new_iter);
+
+	return error;
+}
+
+int git_diff__from_iterators(
+	git_diff **out,
+	git_repository *repo,
+	git_iterator *old_iter,
+	git_iterator *new_iter,
+	const git_diff_options *opts)
+{
+	git_diff_generated *diff;
+	diff_in_progress info;
+	int error = 0;
+
+	*out = NULL;
+
+	diff = diff_generated_alloc(repo, old_iter, new_iter);
+	GITERR_CHECK_ALLOC(diff);
+
+	info.repo = repo;
+	info.old_iter = old_iter;
+	info.new_iter = new_iter;
+
+	/* make iterators have matching icase behavior */
+	if (DIFF_FLAG_IS_SET(diff, GIT_DIFF_IGNORE_CASE)) {
+		git_iterator_set_ignore_case(old_iter, true);
+		git_iterator_set_ignore_case(new_iter, true);
+	}
+
+	/* finish initialization */
+	if ((error = diff_generated_apply_options(diff, opts)) < 0)
+		goto cleanup;
+
+	if ((error = iterator_current(&info.oitem, old_iter)) < 0 ||
+		(error = iterator_current(&info.nitem, new_iter)) < 0)
+		goto cleanup;
+
+	/* run iterators building diffs */
+	while (!error && (info.oitem || info.nitem)) {
+		int cmp;
+
+		/* report progress */
+		if (opts && opts->progress_cb) {
+			if ((error = opts->progress_cb(&diff->base,
+					info.oitem ? info.oitem->path : NULL,
+					info.nitem ? info.nitem->path : NULL,
+					opts->payload)))
+				break;
+		}
+
+		cmp = info.oitem ?
+			(info.nitem ? diff->base.entrycomp(info.oitem, info.nitem) : -1) : 1;
+
+		/* create DELETED records for old items not matched in new */
+		if (cmp < 0)
+			error = handle_unmatched_old_item(diff, &info);
+
+		/* create ADDED, TRACKED, or IGNORED records for new items not
+		 * matched in old (and/or descend into directories as needed)
+		 */
+		else if (cmp > 0)
+			error = handle_unmatched_new_item(diff, &info);
+
+		/* otherwise item paths match, so create MODIFIED record
+		 * (or ADDED and DELETED pair if type changed)
+		 */
+		else
+			error = handle_matched_item(diff, &info);
+	}
+
+	diff->base.perf.stat_calls +=
+		old_iter->stat_calls + new_iter->stat_calls;
+
+cleanup:
+	if (!error)
+		*out = &diff->base;
+	else
+		git_diff_free(&diff->base);
+
+	return error;
+}
+
+#define DIFF_FROM_ITERATORS(MAKE_FIRST, FLAGS_FIRST, MAKE_SECOND, FLAGS_SECOND) do { \
+	git_iterator *a = NULL, *b = NULL; \
+	char *pfx = (opts && !(opts->flags & GIT_DIFF_DISABLE_PATHSPEC_MATCH)) ? \
+		git_pathspec_prefix(&opts->pathspec) : NULL; \
+	git_iterator_options a_opts = GIT_ITERATOR_OPTIONS_INIT, \
+		b_opts = GIT_ITERATOR_OPTIONS_INIT; \
+	a_opts.flags = FLAGS_FIRST; \
+	a_opts.start = pfx; \
+	a_opts.end = pfx; \
+	b_opts.flags = FLAGS_SECOND; \
+	b_opts.start = pfx; \
+	b_opts.end = pfx; \
+	GITERR_CHECK_VERSION(opts, GIT_DIFF_OPTIONS_VERSION, "git_diff_options"); \
+	if (opts && (opts->flags & GIT_DIFF_DISABLE_PATHSPEC_MATCH)) { \
+		a_opts.pathlist.strings = opts->pathspec.strings; \
+		a_opts.pathlist.count = opts->pathspec.count; \
+		b_opts.pathlist.strings = opts->pathspec.strings; \
+		b_opts.pathlist.count = opts->pathspec.count; \
+	} \
+	if (!error && !(error = MAKE_FIRST) && !(error = MAKE_SECOND)) \
+		error = git_diff__from_iterators(&diff, repo, a, b, opts); \
+	git__free(pfx); git_iterator_free(a); git_iterator_free(b); \
+} while (0)
+
+int git_diff_tree_to_tree(
+	git_diff **out,
+	git_repository *repo,
+	git_tree *old_tree,
+	git_tree *new_tree,
+	const git_diff_options *opts)
+{
+	git_diff *diff = NULL;
+	git_iterator_flag_t iflag = GIT_ITERATOR_DONT_IGNORE_CASE;
+	int error = 0;
+
+	assert(out && repo);
+
+	*out = NULL;
+
+	/* for tree to tree diff, be case sensitive even if the index is
+	 * currently case insensitive, unless the user explicitly asked
+	 * for case insensitivity
+	 */
+	if (opts && (opts->flags & GIT_DIFF_IGNORE_CASE) != 0)
+		iflag = GIT_ITERATOR_IGNORE_CASE;
+
+	DIFF_FROM_ITERATORS(
+		git_iterator_for_tree(&a, old_tree, &a_opts), iflag,
+		git_iterator_for_tree(&b, new_tree, &b_opts), iflag
+	);
+
+	if (!error)
+		*out = diff;
+
+	return error;
+}
+
+static int diff_load_index(git_index **index, git_repository *repo)
+{
+	int error = git_repository_index__weakptr(index, repo);
+
+	/* reload the repository index when user did not pass one in */
+	if (!error && git_index_read(*index, false) < 0)
+		giterr_clear();
+
+	return error;
+}
+
+int git_diff_tree_to_index(
+	git_diff **out,
+	git_repository *repo,
+	git_tree *old_tree,
+	git_index *index,
+	const git_diff_options *opts)
+{
+	git_diff *diff = NULL;
+	git_iterator_flag_t iflag = GIT_ITERATOR_DONT_IGNORE_CASE |
+		GIT_ITERATOR_INCLUDE_CONFLICTS;
+	bool index_ignore_case = false;
+	int error = 0;
+
+	assert(out && repo);
+
+	*out = NULL;
+
+	if (!index && (error = diff_load_index(&index, repo)) < 0)
+		return error;
+
+	index_ignore_case = index->ignore_case;
+
+	DIFF_FROM_ITERATORS(
+		git_iterator_for_tree(&a, old_tree, &a_opts), iflag,
+		git_iterator_for_index(&b, repo, index, &b_opts), iflag
+	);
+
+	/* if index is in case-insensitive order, re-sort deltas to match */
+	if (!error && index_ignore_case)
+		git_diff__set_ignore_case(diff, true);
+
+	if (!error)
+		*out = diff;
+
+	return error;
+}
+
+int git_diff_index_to_workdir(
+	git_diff **out,
+	git_repository *repo,
+	git_index *index,
+	const git_diff_options *opts)
+{
+	git_diff *diff = NULL;
+	int error = 0;
+
+	assert(out && repo);
+
+	*out = NULL;
+
+	if (!index && (error = diff_load_index(&index, repo)) < 0)
+		return error;
+
+	DIFF_FROM_ITERATORS(
+		git_iterator_for_index(&a, repo, index, &a_opts),
+		GIT_ITERATOR_INCLUDE_CONFLICTS,
+
+		git_iterator_for_workdir(&b, repo, index, NULL, &b_opts),
+		GIT_ITERATOR_DONT_AUTOEXPAND
+	);
+
+	if (!error && (diff->opts.flags & GIT_DIFF_UPDATE_INDEX) != 0 &&
+		((git_diff_generated *)diff)->index_updated)
+		error = git_index_write(index);
+
+	if (!error)
+		*out = diff;
+
+	return error;
+}
+
+int git_diff_tree_to_workdir(
+	git_diff **out,
+	git_repository *repo,
+	git_tree *old_tree,
+	const git_diff_options *opts)
+{
+	git_diff *diff = NULL;
+	git_index *index;
+	int error = 0;
+
+	assert(out && repo);
+
+	*out = NULL;
+
+	if ((error = git_repository_index__weakptr(&index, repo)))
+		return error;
+
+	DIFF_FROM_ITERATORS(
+		git_iterator_for_tree(&a, old_tree, &a_opts), 0,
+		git_iterator_for_workdir(&b, repo, index, old_tree, &b_opts), GIT_ITERATOR_DONT_AUTOEXPAND
+	);
+
+	if (!error)
+		*out = diff;
+
+	return error;
+}
+
+int git_diff_tree_to_workdir_with_index(
+	git_diff **out,
+	git_repository *repo,
+	git_tree *tree,
+	const git_diff_options *opts)
+{
+	git_diff *d1 = NULL, *d2 = NULL;
+	git_index *index = NULL;
+	int error = 0;
+
+	assert(out && repo);
+
+	*out = NULL;
+
+	if ((error = diff_load_index(&index, repo)) < 0)
+		return error;
+
+	if (!(error = git_diff_tree_to_index(&d1, repo, tree, index, opts)) &&
+		!(error = git_diff_index_to_workdir(&d2, repo, index, opts)))
+		error = git_diff_merge(d1, d2);
+
+	git_diff_free(d2);
+
+	if (error) {
+		git_diff_free(d1);
+		d1 = NULL;
+	}
+
+	*out = d1;
+	return error;
+}
+
+int git_diff_index_to_index(
+	git_diff **out,
+	git_repository *repo,
+	git_index *old_index,
+	git_index *new_index,
+	const git_diff_options *opts)
+{
+	git_diff *diff;
+	int error = 0;
+
+	assert(out && old_index && new_index);
+
+	*out = NULL;
+
+	DIFF_FROM_ITERATORS(
+		git_iterator_for_index(&a, repo, old_index, &a_opts), GIT_ITERATOR_DONT_IGNORE_CASE,
+		git_iterator_for_index(&b, repo, new_index, &b_opts), GIT_ITERATOR_DONT_IGNORE_CASE
+	);
+
+	/* if index is in case-insensitive order, re-sort deltas to match */
+	if (!error && (old_index->ignore_case || new_index->ignore_case))
+		git_diff__set_ignore_case(diff, true);
+
+	if (!error)
+		*out = diff;
+
+	return error;
+}
+
+int git_diff__paired_foreach(
+	git_diff *head2idx,
+	git_diff *idx2wd,
+	int (*cb)(git_diff_delta *h2i, git_diff_delta *i2w, void *payload),
+	void *payload)
+{
+	int cmp, error = 0;
+	git_diff_delta *h2i, *i2w;
+	size_t i, j, i_max, j_max;
+	int (*strcomp)(const char *, const char *) = git__strcmp;
+	bool h2i_icase, i2w_icase, icase_mismatch;
+
+	i_max = head2idx ? head2idx->deltas.length : 0;
+	j_max = idx2wd ? idx2wd->deltas.length : 0;
+	if (!i_max && !j_max)
+		return 0;
+
+	/* At some point, tree-to-index diffs will probably never ignore case,
+	 * even if that isn't true now.  Index-to-workdir diffs may or may not
+	 * ignore case, but the index filename for the idx2wd diff should
+	 * still be using the canonical case-preserving name.
+	 *
+	 * Therefore the main thing we need to do here is make sure the diffs
+	 * are traversed in a compatible order.  To do this, we temporarily
+	 * resort a mismatched diff to get the order correct.
+	 *
+	 * In order to traverse renames in the index->workdir, we need to
+	 * ensure that we compare the index name on both sides, so we
+	 * always sort by the old name in the i2w list.
+	 */
+	h2i_icase = head2idx != NULL && git_diff_is_sorted_icase(head2idx);
+	i2w_icase = idx2wd != NULL && git_diff_is_sorted_icase(idx2wd);
+
+	icase_mismatch =
+		(head2idx != NULL && idx2wd != NULL && h2i_icase != i2w_icase);
+
+	if (icase_mismatch && h2i_icase) {
+		git_vector_set_cmp(&head2idx->deltas, git_diff_delta__cmp);
+		git_vector_sort(&head2idx->deltas);
+	}
+
+	if (i2w_icase && !icase_mismatch) {
+		strcomp = git__strcasecmp;
+
+		git_vector_set_cmp(&idx2wd->deltas, git_diff_delta__i2w_casecmp);
+		git_vector_sort(&idx2wd->deltas);
+	} else if (idx2wd != NULL) {
+		git_vector_set_cmp(&idx2wd->deltas, git_diff_delta__i2w_cmp);
+		git_vector_sort(&idx2wd->deltas);
+	}
+
+	for (i = 0, j = 0; i < i_max || j < j_max; ) {
+		h2i = head2idx ? GIT_VECTOR_GET(&head2idx->deltas, i) : NULL;
+		i2w = idx2wd ? GIT_VECTOR_GET(&idx2wd->deltas, j) : NULL;
+
+		cmp = !i2w ? -1 : !h2i ? 1 :
+			strcomp(h2i->new_file.path, i2w->old_file.path);
+
+		if (cmp < 0) {
+			i++; i2w = NULL;
+		} else if (cmp > 0) {
+			j++; h2i = NULL;
+		} else {
+			i++; j++;
+		}
+
+		if ((error = cb(h2i, i2w, payload)) != 0) {
+			giterr_set_after_callback(error);
+			break;
+		}
+	}
+
+	/* restore case-insensitive delta sort */
+	if (icase_mismatch && h2i_icase) {
+		git_vector_set_cmp(&head2idx->deltas, git_diff_delta__casecmp);
+		git_vector_sort(&head2idx->deltas);
+	}
+
+	/* restore idx2wd sort by new path */
+	if (idx2wd != NULL) {
+		git_vector_set_cmp(&idx2wd->deltas,
+			i2w_icase ? git_diff_delta__casecmp : git_diff_delta__cmp);
+		git_vector_sort(&idx2wd->deltas);
+	}
+
+	return error;
+}
+
+int git_diff__commit(
+	git_diff **out,
+	git_repository *repo,
+	const git_commit *commit,
+	const git_diff_options *opts)
+{
+	git_commit *parent = NULL;
+	git_diff *commit_diff = NULL;
+	git_tree *old_tree = NULL, *new_tree = NULL;
+	size_t parents;
+	int error = 0;
+
+	*out = NULL;
+
+	if ((parents = git_commit_parentcount(commit)) > 1) {
+		char commit_oidstr[GIT_OID_HEXSZ + 1];
+
+		error = -1;
+		giterr_set(GITERR_INVALID, "commit %s is a merge commit",
+			git_oid_tostr(commit_oidstr, GIT_OID_HEXSZ + 1, git_commit_id(commit)));
+		goto on_error;
+	}
+
+	if (parents > 0)
+		if ((error = git_commit_parent(&parent, commit, 0)) < 0 ||
+			(error = git_commit_tree(&old_tree, parent)) < 0)
+				goto on_error;
+
+	if ((error = git_commit_tree(&new_tree, commit)) < 0 ||
+		(error = git_diff_tree_to_tree(&commit_diff, repo, old_tree, new_tree, opts)) < 0)
+			goto on_error;
+
+	*out = commit_diff;
+
+on_error:
+	git_tree_free(new_tree);
+	git_tree_free(old_tree);
+	git_commit_free(parent);
+
+	return error;
+}
+

vendor/libgit2-sys/libgit2/src/diff_generate.h

diff --git a/vendor/libgit2-sys/libgit2/src/diff_generate.h b/vendor/libgit2-sys/libgit2/src/diff_generate.h
new file mode 100644
index 0000000..3f182b0
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/diff_generate.h
@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_diff_generate_h__
+#define INCLUDE_diff_generate_h__
+
+#include "common.h"
+
+#include "diff.h"
+#include "pool.h"
+#include "index.h"
+
+enum {
+	GIT_DIFFCAPS_HAS_SYMLINKS     = (1 << 0), /* symlinks on platform? */
+	GIT_DIFFCAPS_IGNORE_STAT      = (1 << 1), /* use stat? */
+	GIT_DIFFCAPS_TRUST_MODE_BITS  = (1 << 2), /* use st_mode? */
+	GIT_DIFFCAPS_TRUST_CTIME      = (1 << 3), /* use st_ctime? */
+	GIT_DIFFCAPS_USE_DEV          = (1 << 4), /* use st_dev? */
+};
+
+#define DIFF_FLAGS_KNOWN_BINARY (GIT_DIFF_FLAG_BINARY|GIT_DIFF_FLAG_NOT_BINARY)
+#define DIFF_FLAGS_NOT_BINARY   (GIT_DIFF_FLAG_NOT_BINARY|GIT_DIFF_FLAG__NO_DATA)
+
+enum {
+	GIT_DIFF_FLAG__FREE_PATH  = (1 << 7),  /* `path` is allocated memory */
+	GIT_DIFF_FLAG__FREE_DATA  = (1 << 8),  /* internal file data is allocated */
+	GIT_DIFF_FLAG__UNMAP_DATA = (1 << 9),  /* internal file data is mmap'ed */
+	GIT_DIFF_FLAG__NO_DATA    = (1 << 10), /* file data should not be loaded */
+	GIT_DIFF_FLAG__FREE_BLOB  = (1 << 11), /* release the blob when done */
+	GIT_DIFF_FLAG__LOADED     = (1 << 12), /* file data has been loaded */
+
+	GIT_DIFF_FLAG__TO_DELETE  = (1 << 16), /* delete entry during rename det. */
+	GIT_DIFF_FLAG__TO_SPLIT   = (1 << 17), /* split entry during rename det. */
+	GIT_DIFF_FLAG__IS_RENAME_TARGET = (1 << 18),
+	GIT_DIFF_FLAG__IS_RENAME_SOURCE = (1 << 19),
+	GIT_DIFF_FLAG__HAS_SELF_SIMILARITY = (1 << 20),
+};
+
+#define GIT_DIFF_FLAG__CLEAR_INTERNAL(F) (F) = ((F) & 0x00FFFF)
+
+#define GIT_DIFF__VERBOSE  (1 << 30)
+
+extern void git_diff_addref(git_diff *diff);
+
+extern bool git_diff_delta__should_skip(
+	const git_diff_options *opts, const git_diff_delta *delta);
+
+extern int git_diff__from_iterators(
+	git_diff **diff_ptr,
+	git_repository *repo,
+	git_iterator *old_iter,
+	git_iterator *new_iter,
+	const git_diff_options *opts);
+
+extern int git_diff__commit(
+	git_diff **diff, git_repository *repo, const git_commit *commit, const git_diff_options *opts);
+
+extern int git_diff__paired_foreach(
+	git_diff *idx2head,
+	git_diff *wd2idx,
+	int (*cb)(git_diff_delta *i2h, git_diff_delta *w2i, void *payload),
+	void *payload);
+
+/* Merge two `git_diff`s according to the callback given by `cb`. */
+
+typedef git_diff_delta *(*git_diff__merge_cb)(
+	const git_diff_delta *left,
+	const git_diff_delta *right,
+	git_pool *pool);
+
+extern int git_diff__merge(
+	git_diff *onto, const git_diff *from, git_diff__merge_cb cb);
+
+extern git_diff_delta *git_diff__merge_like_cgit(
+	const git_diff_delta *a,
+	const git_diff_delta *b,
+	git_pool *pool);
+
+/* Duplicate a `git_diff_delta` out of the `git_pool` */
+extern git_diff_delta *git_diff__delta_dup(
+	const git_diff_delta *d, git_pool *pool);
+
+extern int git_diff__oid_for_file(
+	git_oid *out,
+	git_diff *diff,
+	const char *path,
+	uint16_t mode,
+	git_off_t size);
+
+extern int git_diff__oid_for_entry(
+	git_oid *out,
+	git_diff *diff,
+	const git_index_entry *src,
+	uint16_t mode,
+	const git_oid *update_match);
+
+/*
+ * Sometimes a git_diff_file will have a zero size; this attempts to
+ * fill in the size without loading the blob if possible.  If that is
+ * not possible, then it will return the git_odb_object that had to be
+ * loaded and the caller can use it or dispose of it as needed.
+ */
+GIT_INLINE(int) git_diff_file__resolve_zero_size(
+	git_diff_file *file, git_odb_object **odb_obj, git_repository *repo)
+{
+	int error;
+	git_odb *odb;
+	size_t len;
+	git_otype type;
+
+	if ((error = git_repository_odb(&odb, repo)) < 0)
+		return error;
+
+	error = git_odb__read_header_or_object(
+		odb_obj, &len, &type, odb, &file->id);
+
+	git_odb_free(odb);
+
+	if (!error)
+		file->size = (git_off_t)len;
+
+	return error;
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/diff_parse.c

diff --git a/vendor/libgit2-sys/libgit2/src/diff_parse.c b/vendor/libgit2-sys/libgit2/src/diff_parse.c
new file mode 100644
index 0000000..59fd861
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/diff_parse.c
@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "diff_parse.h"
+
+#include "diff.h"
+#include "patch.h"
+#include "patch_parse.h"
+
+static void diff_parsed_free(git_diff *d)
+{
+	git_diff_parsed *diff = (git_diff_parsed *)d;
+	git_patch *patch;
+	size_t i;
+
+	git_vector_foreach(&diff->patches, i, patch)
+		git_patch_free(patch);
+
+	git_vector_free(&diff->patches);
+
+	git_vector_free(&diff->base.deltas);
+	git_pool_clear(&diff->base.pool);
+
+	git__memzero(diff, sizeof(*diff));
+	git__free(diff);
+}
+
+static git_diff_parsed *diff_parsed_alloc(void)
+{
+	git_diff_parsed *diff;
+
+	if ((diff = git__calloc(1, sizeof(git_diff_parsed))) == NULL)
+		return NULL;
+
+	GIT_REFCOUNT_INC(&diff->base);
+	diff->base.type = GIT_DIFF_TYPE_PARSED;
+	diff->base.strcomp = git__strcmp;
+	diff->base.strncomp = git__strncmp;
+	diff->base.pfxcomp = git__prefixcmp;
+	diff->base.entrycomp = git_diff__entry_cmp;
+	diff->base.patch_fn = git_patch_parsed_from_diff;
+	diff->base.free_fn = diff_parsed_free;
+
+	if (git_diff_init_options(&diff->base.opts, GIT_DIFF_OPTIONS_VERSION) < 0) {
+		git__free(diff);
+		return NULL;
+	}
+
+	diff->base.opts.flags &= ~GIT_DIFF_IGNORE_CASE;
+
+	git_pool_init(&diff->base.pool, 1);
+
+	if (git_vector_init(&diff->patches, 0, NULL) < 0 ||
+		git_vector_init(&diff->base.deltas, 0, git_diff_delta__cmp) < 0) {
+		git_diff_free(&diff->base);
+		return NULL;
+	}
+
+	git_vector_set_cmp(&diff->base.deltas, git_diff_delta__cmp);
+
+	return diff;
+}
+
+int git_diff_from_buffer(
+	git_diff **out,
+	const char *content,
+	size_t content_len)
+{
+	git_diff_parsed *diff;
+	git_patch *patch;
+	git_patch_parse_ctx *ctx = NULL;
+	int error = 0;
+
+	*out = NULL;
+
+	diff = diff_parsed_alloc();
+	GITERR_CHECK_ALLOC(diff);
+
+	ctx = git_patch_parse_ctx_init(content, content_len, NULL);
+	GITERR_CHECK_ALLOC(ctx);
+
+	while (ctx->parse_ctx.remain_len) {
+		if ((error = git_patch_parse(&patch, ctx)) < 0)
+			break;
+
+		git_vector_insert(&diff->patches, patch);
+		git_vector_insert(&diff->base.deltas, patch->delta);
+	}
+
+	if (error == GIT_ENOTFOUND && git_vector_length(&diff->patches) > 0) {
+		giterr_clear();
+		error = 0;
+	}
+
+	git_patch_parse_ctx_free(ctx);
+
+	if (error < 0)
+		git_diff_free(&diff->base);
+	else
+		*out = &diff->base;
+
+	return error;
+}
+

vendor/libgit2-sys/libgit2/src/diff_parse.h

diff --git a/vendor/libgit2-sys/libgit2/src/diff_parse.h b/vendor/libgit2-sys/libgit2/src/diff_parse.h
new file mode 100644
index 0000000..8767821
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/diff_parse.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_diff_parse_h__
+#define INCLUDE_diff_parse_h__
+
+#include "common.h"
+
+#include "diff.h"
+
+typedef struct {
+	struct git_diff base;
+
+	git_vector patches;
+} git_diff_parsed;
+
+#endif

vendor/libgit2-sys/libgit2/src/diff_print.c

diff --git a/vendor/libgit2-sys/libgit2/src/diff_print.c b/vendor/libgit2-sys/libgit2/src/diff_print.c
new file mode 100644
index 0000000..5e53548
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/diff_print.c
@@ -0,0 +1,790 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "diff.h"
+#include "diff_file.h"
+#include "patch_generate.h"
+#include "fileops.h"
+#include "zstream.h"
+#include "blob.h"
+#include "delta.h"
+#include "git2/sys/diff.h"
+
+typedef struct {
+	git_diff_format_t format;
+	git_diff_line_cb print_cb;
+	void *payload;
+
+	git_buf *buf;
+	git_diff_line line;
+
+	const char *old_prefix;
+	const char *new_prefix;
+	uint32_t flags;
+	int id_strlen;
+
+	int (*strcomp)(const char *, const char *);
+} diff_print_info;
+
+static int diff_print_info_init__common(
+	diff_print_info *pi,
+	git_buf *out,
+	git_repository *repo,
+	git_diff_format_t format,
+	git_diff_line_cb cb,
+	void *payload)
+{
+	pi->format = format;
+	pi->print_cb = cb;
+	pi->payload = payload;
+	pi->buf = out;
+
+	if (!pi->id_strlen) {
+		if (!repo)
+			pi->id_strlen = GIT_ABBREV_DEFAULT;
+		else if (git_repository__cvar(&pi->id_strlen, repo, GIT_CVAR_ABBREV) < 0)
+			return -1;
+	}
+
+	if (pi->id_strlen > GIT_OID_HEXSZ)
+		pi->id_strlen = GIT_OID_HEXSZ;
+
+	memset(&pi->line, 0, sizeof(pi->line));
+	pi->line.old_lineno = -1;
+	pi->line.new_lineno = -1;
+	pi->line.num_lines = 1;
+
+	return 0;
+}
+
+static int diff_print_info_init_fromdiff(
+	diff_print_info *pi,
+	git_buf *out,
+	git_diff *diff,
+	git_diff_format_t format,
+	git_diff_line_cb cb,
+	void *payload)
+{
+	git_repository *repo = diff ? diff->repo : NULL;
+
+	memset(pi, 0, sizeof(diff_print_info));
+
+	if (diff) {
+		pi->flags = diff->opts.flags;
+		pi->id_strlen = diff->opts.id_abbrev;
+		pi->old_prefix = diff->opts.old_prefix;
+		pi->new_prefix = diff->opts.new_prefix;
+
+		pi->strcomp = diff->strcomp;
+	}
+
+	return diff_print_info_init__common(pi, out, repo, format, cb, payload);
+}
+
+static int diff_print_info_init_frompatch(
+	diff_print_info *pi,
+	git_buf *out,
+	git_patch *patch,
+	git_diff_format_t format,
+	git_diff_line_cb cb,
+	void *payload)
+{
+	assert(patch);
+
+	memset(pi, 0, sizeof(diff_print_info));
+
+	pi->flags = patch->diff_opts.flags;
+	pi->id_strlen = patch->diff_opts.id_abbrev;
+	pi->old_prefix = patch->diff_opts.old_prefix;
+	pi->new_prefix = patch->diff_opts.new_prefix;
+
+	return diff_print_info_init__common(pi, out, patch->repo, format, cb, payload);
+}
+
+static char diff_pick_suffix(int mode)
+{
+	if (S_ISDIR(mode))
+		return '/';
+	else if (GIT_PERMS_IS_EXEC(mode)) /* -V536 */
+		/* in git, modes are very regular, so we must have 0100755 mode */
+		return '*';
+	else
+		return ' ';
+}
+
+char git_diff_status_char(git_delta_t status)
+{
+	char code;
+
+	switch (status) {
+	case GIT_DELTA_ADDED:      code = 'A'; break;
+	case GIT_DELTA_DELETED:    code = 'D'; break;
+	case GIT_DELTA_MODIFIED:   code = 'M'; break;
+	case GIT_DELTA_RENAMED:    code = 'R'; break;
+	case GIT_DELTA_COPIED:     code = 'C'; break;
+	case GIT_DELTA_IGNORED:    code = 'I'; break;
+	case GIT_DELTA_UNTRACKED:  code = '?'; break;
+	case GIT_DELTA_TYPECHANGE: code = 'T'; break;
+	case GIT_DELTA_UNREADABLE: code = 'X'; break;
+	default:                   code = ' '; break;
+	}
+
+	return code;
+}
+
+static int diff_print_one_name_only(
+	const git_diff_delta *delta, float progress, void *data)
+{
+	diff_print_info *pi = data;
+	git_buf *out = pi->buf;
+
+	GIT_UNUSED(progress);
+
+	if ((pi->flags & GIT_DIFF_SHOW_UNMODIFIED) == 0 &&
+		delta->status == GIT_DELTA_UNMODIFIED)
+		return 0;
+
+	git_buf_clear(out);
+	git_buf_puts(out, delta->new_file.path);
+	git_buf_putc(out, '\n');
+	if (git_buf_oom(out))
+		return -1;
+
+	pi->line.origin      = GIT_DIFF_LINE_FILE_HDR;
+	pi->line.content     = git_buf_cstr(out);
+	pi->line.content_len = git_buf_len(out);
+
+	return pi->print_cb(delta, NULL, &pi->line, pi->payload);
+}
+
+static int diff_print_one_name_status(
+	const git_diff_delta *delta, float progress, void *data)
+{
+	diff_print_info *pi = data;
+	git_buf *out = pi->buf;
+	char old_suffix, new_suffix, code = git_diff_status_char(delta->status);
+	int(*strcomp)(const char *, const char *) = pi->strcomp ?
+		pi->strcomp : git__strcmp;
+
+	GIT_UNUSED(progress);
+
+	if ((pi->flags & GIT_DIFF_SHOW_UNMODIFIED) == 0 && code == ' ')
+		return 0;
+
+	old_suffix = diff_pick_suffix(delta->old_file.mode);
+	new_suffix = diff_pick_suffix(delta->new_file.mode);
+
+	git_buf_clear(out);
+
+	if (delta->old_file.path != delta->new_file.path &&
+		strcomp(delta->old_file.path,delta->new_file.path) != 0)
+		git_buf_printf(out, "%c\t%s%c %s%c\n", code,
+			delta->old_file.path, old_suffix, delta->new_file.path, new_suffix);
+	else if (delta->old_file.mode != delta->new_file.mode &&
+		delta->old_file.mode != 0 && delta->new_file.mode != 0)
+		git_buf_printf(out, "%c\t%s%c %s%c\n", code,
+			delta->old_file.path, old_suffix, delta->new_file.path, new_suffix);
+	else if (old_suffix != ' ')
+		git_buf_printf(out, "%c\t%s%c\n", code, delta->old_file.path, old_suffix);
+	else
+		git_buf_printf(out, "%c\t%s\n", code, delta->old_file.path);
+	if (git_buf_oom(out))
+		return -1;
+
+	pi->line.origin      = GIT_DIFF_LINE_FILE_HDR;
+	pi->line.content     = git_buf_cstr(out);
+	pi->line.content_len = git_buf_len(out);
+
+	return pi->print_cb(delta, NULL, &pi->line, pi->payload);
+}
+
+static int diff_print_one_raw(
+	const git_diff_delta *delta, float progress, void *data)
+{
+	diff_print_info *pi = data;
+	git_buf *out = pi->buf;
+	int id_abbrev;
+	char code = git_diff_status_char(delta->status);
+	char start_oid[GIT_OID_HEXSZ+1], end_oid[GIT_OID_HEXSZ+1];
+
+	GIT_UNUSED(progress);
+
+	if ((pi->flags & GIT_DIFF_SHOW_UNMODIFIED) == 0 && code == ' ')
+		return 0;
+
+	git_buf_clear(out);
+
+	id_abbrev = delta->old_file.mode ? delta->old_file.id_abbrev :
+		delta->new_file.id_abbrev;
+
+	if (pi->id_strlen > id_abbrev) {
+		giterr_set(GITERR_PATCH,
+			"the patch input contains %d id characters (cannot print %d)",
+			id_abbrev, pi->id_strlen);
+		return -1;
+	}
+
+	git_oid_tostr(start_oid, pi->id_strlen + 1, &delta->old_file.id);
+	git_oid_tostr(end_oid, pi->id_strlen + 1, &delta->new_file.id);
+
+	git_buf_printf(
+		out, (pi->id_strlen <= GIT_OID_HEXSZ) ?
+			":%06o %06o %s... %s... %c" : ":%06o %06o %s %s %c",
+		delta->old_file.mode, delta->new_file.mode, start_oid, end_oid, code);
+
+	if (delta->similarity > 0)
+		git_buf_printf(out, "%03u", delta->similarity);
+
+	if (delta->old_file.path != delta->new_file.path)
+		git_buf_printf(
+			out, "\t%s %s\n", delta->old_file.path, delta->new_file.path);
+	else
+		git_buf_printf(
+			out, "\t%s\n", delta->old_file.path ?
+			delta->old_file.path : delta->new_file.path);
+
+	if (git_buf_oom(out))
+		return -1;
+
+	pi->line.origin      = GIT_DIFF_LINE_FILE_HDR;
+	pi->line.content     = git_buf_cstr(out);
+	pi->line.content_len = git_buf_len(out);
+
+	return pi->print_cb(delta, NULL, &pi->line, pi->payload);
+}
+
+static int diff_print_modes(
+	git_buf *out, const git_diff_delta *delta)
+{
+	git_buf_printf(out, "old mode %o\n", delta->old_file.mode);
+	git_buf_printf(out, "new mode %o\n", delta->new_file.mode);
+
+	return git_buf_oom(out) ? -1 : 0;
+}
+
+static int diff_print_oid_range(
+	git_buf *out, const git_diff_delta *delta, int id_strlen)
+{
+	char start_oid[GIT_OID_HEXSZ+1], end_oid[GIT_OID_HEXSZ+1];
+
+	if (delta->old_file.mode &&
+			id_strlen > delta->old_file.id_abbrev) {
+		giterr_set(GITERR_PATCH,
+			"the patch input contains %d id characters (cannot print %d)",
+			delta->old_file.id_abbrev, id_strlen);
+		return -1;
+	}
+
+	if ((delta->new_file.mode &&
+			id_strlen > delta->new_file.id_abbrev)) {
+		giterr_set(GITERR_PATCH,
+			"the patch input contains %d id characters (cannot print %d)",
+			delta->new_file.id_abbrev, id_strlen);
+		return -1;
+	}
+
+	git_oid_tostr(start_oid, id_strlen + 1, &delta->old_file.id);
+	git_oid_tostr(end_oid, id_strlen + 1, &delta->new_file.id);
+
+	if (delta->old_file.mode == delta->new_file.mode) {
+		git_buf_printf(out, "index %s..%s %o\n",
+			start_oid, end_oid, delta->old_file.mode);
+	} else {
+		if (delta->old_file.mode == 0)
+			git_buf_printf(out, "new file mode %o\n", delta->new_file.mode);
+		else if (delta->new_file.mode == 0)
+			git_buf_printf(out, "deleted file mode %o\n", delta->old_file.mode);
+		else
+			diff_print_modes(out, delta);
+
+		git_buf_printf(out, "index %s..%s\n", start_oid, end_oid);
+	}
+
+	return git_buf_oom(out) ? -1 : 0;
+}
+
+static int diff_delta_format_path(
+	git_buf *out, const char *prefix, const char *filename)
+{
+	if (git_buf_joinpath(out, prefix, filename) < 0)
+		return -1;
+
+	return git_buf_quote(out);
+}
+
+static int diff_delta_format_with_paths(
+	git_buf *out,
+	const git_diff_delta *delta,
+	const char *template,
+	const char *oldpath,
+	const char *newpath)
+{
+	if (git_oid_iszero(&delta->old_file.id))
+		oldpath = "/dev/null";
+
+	if (git_oid_iszero(&delta->new_file.id))
+		newpath = "/dev/null";
+
+	return git_buf_printf(out, template, oldpath, newpath);
+}
+
+int diff_delta_format_similarity_header(
+	git_buf *out,
+	const git_diff_delta *delta)
+{
+	git_buf old_path = GIT_BUF_INIT, new_path = GIT_BUF_INIT;
+	const char *type;
+	int error = 0;
+
+	if (delta->similarity > 100) {
+		giterr_set(GITERR_PATCH, "invalid similarity %d", delta->similarity);
+		error = -1;
+		goto done;
+	}
+
+	if (delta->status == GIT_DELTA_RENAMED)
+		type = "rename";
+	else if (delta->status == GIT_DELTA_COPIED)
+		type = "copy";
+	else
+		abort();
+
+	if ((error = git_buf_puts(&old_path, delta->old_file.path)) < 0 ||
+		(error = git_buf_puts(&new_path, delta->new_file.path)) < 0 ||
+		(error = git_buf_quote(&old_path)) < 0 ||
+		(error = git_buf_quote(&new_path)) < 0)
+		goto done;
+
+	git_buf_printf(out,
+		"similarity index %d%%\n"
+		"%s from %s\n"
+		"%s to %s\n",
+		delta->similarity,
+		type, old_path.ptr,
+		type, new_path.ptr);
+
+	if (git_buf_oom(out))
+		error = -1;
+
+done:
+	git_buf_free(&old_path);
+	git_buf_free(&new_path);
+
+	return error;
+}
+
+static bool delta_is_unchanged(const git_diff_delta *delta)
+{
+	if (git_oid_iszero(&delta->old_file.id) &&
+		git_oid_iszero(&delta->new_file.id))
+		return true;
+
+	if (delta->old_file.mode == GIT_FILEMODE_COMMIT ||
+		delta->new_file.mode == GIT_FILEMODE_COMMIT)
+		return false;
+
+	if (git_oid_equal(&delta->old_file.id, &delta->new_file.id))
+		return true;
+
+	return false;
+}
+
+int git_diff_delta__format_file_header(
+	git_buf *out,
+	const git_diff_delta *delta,
+	const char *oldpfx,
+	const char *newpfx,
+	int id_strlen)
+{
+	git_buf old_path = GIT_BUF_INIT, new_path = GIT_BUF_INIT;
+	bool unchanged = delta_is_unchanged(delta);
+	int error = 0;
+
+	if (!oldpfx)
+		oldpfx = DIFF_OLD_PREFIX_DEFAULT;
+	if (!newpfx)
+		newpfx = DIFF_NEW_PREFIX_DEFAULT;
+	if (!id_strlen)
+		id_strlen = GIT_ABBREV_DEFAULT;
+
+	if ((error = diff_delta_format_path(
+			&old_path, oldpfx, delta->old_file.path)) < 0 ||
+		(error = diff_delta_format_path(
+			&new_path, newpfx, delta->new_file.path)) < 0)
+		goto done;
+
+	git_buf_clear(out);
+
+	git_buf_printf(out, "diff --git %s %s\n",
+		old_path.ptr, new_path.ptr);
+
+	if (delta->status == GIT_DELTA_RENAMED ||
+		(delta->status == GIT_DELTA_COPIED && unchanged)) {
+		if ((error = diff_delta_format_similarity_header(out, delta)) < 0)
+			goto done;
+	}
+
+	if (!unchanged) {
+		if ((error = diff_print_oid_range(out, delta, id_strlen)) < 0)
+			goto done;
+
+		if ((delta->flags & GIT_DIFF_FLAG_BINARY) == 0)
+			diff_delta_format_with_paths(out, delta,
+				"--- %s\n+++ %s\n", old_path.ptr, new_path.ptr);
+	}
+
+	if (unchanged && delta->old_file.mode != delta->new_file.mode)
+		diff_print_modes(out, delta);
+
+	if (git_buf_oom(out))
+		error = -1;
+
+done:
+	git_buf_free(&old_path);
+	git_buf_free(&new_path);
+
+	return error;
+}
+
+static int format_binary(
+	diff_print_info *pi,
+	git_diff_binary_t type,
+	const char *data,
+	size_t datalen,
+	size_t inflatedlen)
+{
+	const char *typename = type == GIT_DIFF_BINARY_DELTA ?
+		"delta" : "literal";
+	const char *scan, *end;
+
+	git_buf_printf(pi->buf, "%s %" PRIuZ "\n", typename, inflatedlen);
+	pi->line.num_lines++;
+
+	for (scan = data, end = data + datalen; scan < end; ) {
+		size_t chunk_len = end - scan;
+		if (chunk_len > 52)
+			chunk_len = 52;
+
+		if (chunk_len <= 26)
+			git_buf_putc(pi->buf, (char)chunk_len + 'A' - 1);
+		else
+			git_buf_putc(pi->buf, (char)chunk_len - 26 + 'a' - 1);
+
+		git_buf_encode_base85(pi->buf, scan, chunk_len);
+		git_buf_putc(pi->buf, '\n');
+
+		if (git_buf_oom(pi->buf))
+			return -1;
+
+		scan += chunk_len;
+		pi->line.num_lines++;
+	}
+	git_buf_putc(pi->buf, '\n');
+
+	return 0;
+}
+
+static int diff_print_patch_file_binary_noshow(
+	diff_print_info *pi, git_diff_delta *delta,
+	const char *old_pfx, const char *new_pfx)
+{
+	git_buf old_path = GIT_BUF_INIT, new_path = GIT_BUF_INIT;
+	int error;
+
+	if ((error = diff_delta_format_path(
+			&old_path, old_pfx, delta->old_file.path)) < 0 ||
+		(error = diff_delta_format_path(
+			&new_path, new_pfx, delta->new_file.path)) < 0)
+		goto done;
+
+	pi->line.num_lines = 1;
+	error = diff_delta_format_with_paths(
+		pi->buf, delta, "Binary files %s and %s differ\n",
+		old_path.ptr, new_path.ptr);
+
+done:
+	git_buf_free(&old_path);
+	git_buf_free(&new_path);
+
+	return error;
+}
+
+static int diff_print_patch_file_binary(
+	diff_print_info *pi, git_diff_delta *delta,
+	const char *old_pfx, const char *new_pfx,
+	const git_diff_binary *binary)
+{
+	size_t pre_binary_size;
+	int error;
+
+	if (delta->status == GIT_DELTA_UNMODIFIED)
+		return 0;
+
+	if ((pi->flags & GIT_DIFF_SHOW_BINARY) == 0 || !binary->contains_data)
+		return diff_print_patch_file_binary_noshow(
+			pi, delta, old_pfx, new_pfx);
+
+	pre_binary_size = pi->buf->size;
+	git_buf_printf(pi->buf, "GIT binary patch\n");
+	pi->line.num_lines++;
+
+	if ((error = format_binary(pi, binary->new_file.type, binary->new_file.data,
+		binary->new_file.datalen, binary->new_file.inflatedlen)) < 0 ||
+		(error = format_binary(pi, binary->old_file.type, binary->old_file.data,
+			binary->old_file.datalen, binary->old_file.inflatedlen)) < 0) {
+
+		if (error == GIT_EBUFS) {
+			giterr_clear();
+			git_buf_truncate(pi->buf, pre_binary_size);
+
+			return diff_print_patch_file_binary_noshow(
+				pi, delta, old_pfx, new_pfx);
+		}
+	}
+
+	pi->line.num_lines++;
+	return error;
+}
+
+static int diff_print_patch_file(
+	const git_diff_delta *delta, float progress, void *data)
+{
+	int error;
+	diff_print_info *pi = data;
+	const char *oldpfx =
+		pi->old_prefix ? pi->old_prefix : DIFF_OLD_PREFIX_DEFAULT;
+	const char *newpfx =
+		pi->new_prefix ? pi->new_prefix : DIFF_NEW_PREFIX_DEFAULT;
+
+	bool binary = (delta->flags & GIT_DIFF_FLAG_BINARY) ||
+		(pi->flags & GIT_DIFF_FORCE_BINARY);
+	bool show_binary = !!(pi->flags & GIT_DIFF_SHOW_BINARY);
+	int id_strlen = pi->id_strlen;
+
+	if (binary && show_binary)
+		id_strlen = delta->old_file.id_abbrev ? delta->old_file.id_abbrev :
+			delta->new_file.id_abbrev;
+
+	GIT_UNUSED(progress);
+
+	if (S_ISDIR(delta->new_file.mode) ||
+		delta->status == GIT_DELTA_UNMODIFIED ||
+		delta->status == GIT_DELTA_IGNORED ||
+		delta->status == GIT_DELTA_UNREADABLE ||
+		(delta->status == GIT_DELTA_UNTRACKED &&
+		 (pi->flags & GIT_DIFF_SHOW_UNTRACKED_CONTENT) == 0))
+		return 0;
+
+	if ((error = git_diff_delta__format_file_header(
+			pi->buf, delta, oldpfx, newpfx, id_strlen)) < 0)
+		return error;
+
+	pi->line.origin      = GIT_DIFF_LINE_FILE_HDR;
+	pi->line.content     = git_buf_cstr(pi->buf);
+	pi->line.content_len = git_buf_len(pi->buf);
+
+	return pi->print_cb(delta, NULL, &pi->line, pi->payload);
+}
+
+static int diff_print_patch_binary(
+	const git_diff_delta *delta,
+	const git_diff_binary *binary,
+	void *data)
+{
+	diff_print_info *pi = data;
+	const char *old_pfx =
+		pi->old_prefix ? pi->old_prefix : DIFF_OLD_PREFIX_DEFAULT;
+	const char *new_pfx =
+		pi->new_prefix ? pi->new_prefix : DIFF_NEW_PREFIX_DEFAULT;
+	int error;
+
+	git_buf_clear(pi->buf);
+
+	if ((error = diff_print_patch_file_binary(
+		pi, (git_diff_delta *)delta, old_pfx, new_pfx, binary)) < 0)
+		return error;
+
+	pi->line.origin = GIT_DIFF_LINE_BINARY;
+	pi->line.content = git_buf_cstr(pi->buf);
+	pi->line.content_len = git_buf_len(pi->buf);
+
+	return pi->print_cb(delta, NULL, &pi->line, pi->payload);
+}
+
+static int diff_print_patch_hunk(
+	const git_diff_delta *d,
+	const git_diff_hunk *h,
+	void *data)
+{
+	diff_print_info *pi = data;
+
+	if (S_ISDIR(d->new_file.mode))
+		return 0;
+
+	pi->line.origin      = GIT_DIFF_LINE_HUNK_HDR;
+	pi->line.content     = h->header;
+	pi->line.content_len = h->header_len;
+
+	return pi->print_cb(d, h, &pi->line, pi->payload);
+}
+
+static int diff_print_patch_line(
+	const git_diff_delta *delta,
+	const git_diff_hunk *hunk,
+	const git_diff_line *line,
+	void *data)
+{
+	diff_print_info *pi = data;
+
+	if (S_ISDIR(delta->new_file.mode))
+		return 0;
+
+	return pi->print_cb(delta, hunk, line, pi->payload);
+}
+
+/* print a git_diff to an output callback */
+int git_diff_print(
+	git_diff *diff,
+	git_diff_format_t format,
+	git_diff_line_cb print_cb,
+	void *payload)
+{
+	int error;
+	git_buf buf = GIT_BUF_INIT;
+	diff_print_info pi;
+	git_diff_file_cb print_file = NULL;
+	git_diff_binary_cb print_binary = NULL;
+	git_diff_hunk_cb print_hunk = NULL;
+	git_diff_line_cb print_line = NULL;
+
+	switch (format) {
+	case GIT_DIFF_FORMAT_PATCH:
+		print_file = diff_print_patch_file;
+		print_binary = diff_print_patch_binary;
+		print_hunk = diff_print_patch_hunk;
+		print_line = diff_print_patch_line;
+		break;
+	case GIT_DIFF_FORMAT_PATCH_HEADER:
+		print_file = diff_print_patch_file;
+		break;
+	case GIT_DIFF_FORMAT_RAW:
+		print_file = diff_print_one_raw;
+		break;
+	case GIT_DIFF_FORMAT_NAME_ONLY:
+		print_file = diff_print_one_name_only;
+		break;
+	case GIT_DIFF_FORMAT_NAME_STATUS:
+		print_file = diff_print_one_name_status;
+		break;
+	default:
+		giterr_set(GITERR_INVALID, "unknown diff output format (%d)", format);
+		return -1;
+	}
+
+	if (!(error = diff_print_info_init_fromdiff(
+			&pi, &buf, diff, format, print_cb, payload))) {
+		error = git_diff_foreach(
+			diff, print_file, print_binary, print_hunk, print_line, &pi);
+
+		if (error) /* make sure error message is set */
+			giterr_set_after_callback_function(error, "git_diff_print");
+	}
+
+	git_buf_free(&buf);
+
+	return error;
+}
+
+int git_diff_print_callback__to_buf(
+	const git_diff_delta *delta,
+	const git_diff_hunk *hunk,
+	const git_diff_line *line,
+	void *payload)
+{
+	git_buf *output = payload;
+	GIT_UNUSED(delta); GIT_UNUSED(hunk);
+
+	if (!output) {
+		giterr_set(GITERR_INVALID, "buffer pointer must be provided");
+		return -1;
+	}
+
+	if (line->origin == GIT_DIFF_LINE_ADDITION ||
+		line->origin == GIT_DIFF_LINE_DELETION ||
+		line->origin == GIT_DIFF_LINE_CONTEXT)
+		git_buf_putc(output, line->origin);
+
+	return git_buf_put(output, line->content, line->content_len);
+}
+
+int git_diff_print_callback__to_file_handle(
+	const git_diff_delta *delta,
+	const git_diff_hunk *hunk,
+	const git_diff_line *line,
+	void *payload)
+{
+	FILE *fp = payload ? payload : stdout;
+
+	GIT_UNUSED(delta); GIT_UNUSED(hunk);
+
+	if (line->origin == GIT_DIFF_LINE_CONTEXT ||
+		line->origin == GIT_DIFF_LINE_ADDITION ||
+		line->origin == GIT_DIFF_LINE_DELETION)
+		fputc(line->origin, fp);
+	fwrite(line->content, 1, line->content_len, fp);
+	return 0;
+}
+
+/* print a git_diff to a git_buf */
+int git_diff_to_buf(git_buf *out, git_diff *diff, git_diff_format_t format)
+{
+	assert(out && diff);
+	git_buf_sanitize(out);
+	return git_diff_print(
+		diff, format, git_diff_print_callback__to_buf, out);
+}
+
+/* print a git_patch to an output callback */
+int git_patch_print(
+	git_patch *patch,
+	git_diff_line_cb print_cb,
+	void *payload)
+{
+	int error;
+	git_buf temp = GIT_BUF_INIT;
+	diff_print_info pi;
+
+	assert(patch && print_cb);
+
+	if (!(error = diff_print_info_init_frompatch(
+		&pi, &temp, patch,
+		GIT_DIFF_FORMAT_PATCH, print_cb, payload)))
+	{
+		error = git_patch__invoke_callbacks(
+			patch,
+			diff_print_patch_file, diff_print_patch_binary,
+			diff_print_patch_hunk, diff_print_patch_line,
+			&pi);
+
+		if (error) /* make sure error message is set */
+			giterr_set_after_callback_function(error, "git_patch_print");
+	}
+
+	git_buf_free(&temp);
+
+	return error;
+}
+
+/* print a git_patch to a git_buf */
+int git_patch_to_buf(git_buf *out, git_patch *patch)
+{
+	assert(out && patch);
+	git_buf_sanitize(out);
+	return git_patch_print(patch, git_diff_print_callback__to_buf, out);
+}

vendor/libgit2-sys/libgit2/src/diff_stats.c

diff --git a/vendor/libgit2-sys/libgit2/src/diff_stats.c b/vendor/libgit2-sys/libgit2/src/diff_stats.c
new file mode 100644
index 0000000..583c684
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/diff_stats.c
@@ -0,0 +1,347 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "vector.h"
+#include "diff.h"
+#include "patch_generate.h"
+
+#define DIFF_RENAME_FILE_SEPARATOR " => "
+#define STATS_FULL_MIN_SCALE 7
+
+typedef struct {
+	size_t insertions;
+	size_t deletions;
+} diff_file_stats;
+
+struct git_diff_stats {
+	git_diff *diff;
+	diff_file_stats *filestats;
+
+	size_t files_changed;
+	size_t insertions;
+	size_t deletions;
+	size_t renames;
+
+	size_t max_name;
+	size_t max_filestat;
+	int max_digits;
+};
+
+static int digits_for_value(size_t val)
+{
+	int count = 1;
+	size_t placevalue = 10;
+
+	while (val >= placevalue) {
+		++count;
+		placevalue *= 10;
+	}
+
+	return count;
+}
+
+int git_diff_file_stats__full_to_buf(
+	git_buf *out,
+	const git_diff_delta *delta,
+	const diff_file_stats *filestat,
+	const git_diff_stats *stats,
+	size_t width)
+{
+	const char *old_path = NULL, *new_path = NULL;
+	size_t padding, old_size, new_size;
+
+	old_path = delta->old_file.path;
+	new_path = delta->new_file.path;
+	old_size = delta->old_file.size;
+	new_size = delta->new_file.size;
+
+	if (git_buf_printf(out, " %s", old_path) < 0)
+		goto on_error;
+
+	if (strcmp(old_path, new_path) != 0) {
+		padding = stats->max_name - strlen(old_path) - strlen(new_path);
+
+		if (git_buf_printf(out, DIFF_RENAME_FILE_SEPARATOR "%s", new_path) < 0)
+			goto on_error;
+	} else {
+		padding = stats->max_name - strlen(old_path);
+
+		if (stats->renames > 0)
+			padding += strlen(DIFF_RENAME_FILE_SEPARATOR);
+	}
+
+	if (git_buf_putcn(out, ' ', padding) < 0 ||
+		git_buf_puts(out, " | ") < 0)
+		goto on_error;
+
+	if (delta->flags & GIT_DIFF_FLAG_BINARY) {
+		if (git_buf_printf(out,
+				"Bin %" PRIuZ " -> %" PRIuZ " bytes", old_size, new_size) < 0)
+			goto on_error;
+	}
+	else {
+		if (git_buf_printf(out,
+				"%*" PRIuZ, stats->max_digits,
+				filestat->insertions + filestat->deletions) < 0)
+			goto on_error;
+
+		if (filestat->insertions || filestat->deletions) {
+			if (git_buf_putc(out, ' ') < 0)
+				goto on_error;
+
+			if (!width) {
+				if (git_buf_putcn(out, '+', filestat->insertions) < 0 ||
+					git_buf_putcn(out, '-', filestat->deletions) < 0)
+					goto on_error;
+			} else {
+				size_t total = filestat->insertions + filestat->deletions;
+				size_t full = (total * width + stats->max_filestat / 2) /
+					stats->max_filestat;
+				size_t plus = full * filestat->insertions / total;
+				size_t minus = full - plus;
+
+				if (git_buf_putcn(out, '+', max(plus,  1)) < 0 ||
+					git_buf_putcn(out, '-', max(minus, 1)) < 0)
+					goto on_error;
+			}
+		}
+	}
+
+	git_buf_putc(out, '\n');
+
+on_error:
+	return (git_buf_oom(out) ? -1 : 0);
+}
+
+int git_diff_file_stats__number_to_buf(
+	git_buf *out,
+	const git_diff_delta *delta,
+	const diff_file_stats *filestats)
+{
+	int error;
+	const char *path = delta->new_file.path;
+
+	if (delta->flags & GIT_DIFF_FLAG_BINARY)
+		error = git_buf_printf(out, "%-8c" "%-8c" "%s\n", '-', '-', path);
+	else
+		error = git_buf_printf(out, "%-8" PRIuZ "%-8" PRIuZ "%s\n",
+			filestats->insertions, filestats->deletions, path);
+
+	return error;
+}
+
+int git_diff_file_stats__summary_to_buf(
+	git_buf *out,
+	const git_diff_delta *delta)
+{
+	if (delta->old_file.mode != delta->new_file.mode) {
+		if (delta->old_file.mode == 0) {
+			git_buf_printf(out, " create mode %06o %s\n",
+				delta->new_file.mode, delta->new_file.path);
+		}
+		else if (delta->new_file.mode == 0) {
+			git_buf_printf(out, " delete mode %06o %s\n",
+				delta->old_file.mode, delta->old_file.path);
+		}
+		else {
+			git_buf_printf(out, " mode change %06o => %06o %s\n",
+				delta->old_file.mode, delta->new_file.mode, delta->new_file.path);
+		}
+	}
+
+	return 0;
+}
+
+int git_diff_get_stats(
+	git_diff_stats **out,
+	git_diff *diff)
+{
+	size_t i, deltas;
+	size_t total_insertions = 0, total_deletions = 0;
+	git_diff_stats *stats = NULL;
+	int error = 0;
+
+	assert(out && diff);
+
+	stats = git__calloc(1, sizeof(git_diff_stats));
+	GITERR_CHECK_ALLOC(stats);
+
+	deltas = git_diff_num_deltas(diff);
+
+	stats->filestats = git__calloc(deltas, sizeof(diff_file_stats));
+	if (!stats->filestats) {
+		git__free(stats);
+		return -1;
+	}
+
+	stats->diff = diff;
+	GIT_REFCOUNT_INC(diff);
+
+	for (i = 0; i < deltas && !error; ++i) {
+		git_patch *patch = NULL;
+		size_t add = 0, remove = 0, namelen;
+		const git_diff_delta *delta;
+
+		if ((error = git_patch_from_diff(&patch, diff, i)) < 0)
+			break;
+
+		/* keep a count of renames because it will affect formatting */
+		delta = patch->delta;
+
+		/* TODO ugh */
+		namelen = strlen(delta->new_file.path);
+		if (strcmp(delta->old_file.path, delta->new_file.path) != 0) {
+			namelen += strlen(delta->old_file.path);
+			stats->renames++;
+		}
+
+		/* and, of course, count the line stats */
+		error = git_patch_line_stats(NULL, &add, &remove, patch);
+
+		git_patch_free(patch);
+
+		stats->filestats[i].insertions = add;
+		stats->filestats[i].deletions = remove;
+
+		total_insertions += add;
+		total_deletions += remove;
+
+		if (stats->max_name < namelen)
+			stats->max_name = namelen;
+		if (stats->max_filestat < add + remove)
+			stats->max_filestat = add + remove;
+	}
+
+	stats->files_changed = deltas;
+	stats->insertions = total_insertions;
+	stats->deletions = total_deletions;
+	stats->max_digits = digits_for_value(stats->max_filestat + 1);
+
+	if (error < 0) {
+		git_diff_stats_free(stats);
+		stats = NULL;
+	}
+
+	*out = stats;
+	return error;
+}
+
+size_t git_diff_stats_files_changed(
+	const git_diff_stats *stats)
+{
+	assert(stats);
+
+	return stats->files_changed;
+}
+
+size_t git_diff_stats_insertions(
+	const git_diff_stats *stats)
+{
+	assert(stats);
+
+	return stats->insertions;
+}
+
+size_t git_diff_stats_deletions(
+	const git_diff_stats *stats)
+{
+	assert(stats);
+
+	return stats->deletions;
+}
+
+int git_diff_stats_to_buf(
+	git_buf *out,
+	const git_diff_stats *stats,
+	git_diff_stats_format_t format,
+	size_t width)
+{
+	int error = 0;
+	size_t i;
+	const git_diff_delta *delta;
+
+	assert(out && stats);
+
+	if (format & GIT_DIFF_STATS_NUMBER) {
+		for (i = 0; i < stats->files_changed; ++i) {
+			if ((delta = git_diff_get_delta(stats->diff, i)) == NULL)
+				continue;
+
+			error = git_diff_file_stats__number_to_buf(
+				out, delta, &stats->filestats[i]);
+			if (error < 0)
+				return error;
+		}
+	}
+
+	if (format & GIT_DIFF_STATS_FULL) {
+		if (width > 0) {
+			if (width > stats->max_name + stats->max_digits + 5)
+				width -= (stats->max_name + stats->max_digits + 5);
+			if (width < STATS_FULL_MIN_SCALE)
+				width = STATS_FULL_MIN_SCALE;
+		}
+		if (width > stats->max_filestat)
+			width = 0;
+
+		for (i = 0; i < stats->files_changed; ++i) {
+			if ((delta = git_diff_get_delta(stats->diff, i)) == NULL)
+				continue;
+
+			error = git_diff_file_stats__full_to_buf(
+				out, delta, &stats->filestats[i], stats, width);
+			if (error < 0)
+				return error;
+		}
+	}
+
+	if (format & GIT_DIFF_STATS_FULL || format & GIT_DIFF_STATS_SHORT) {
+		git_buf_printf(
+			out, " %" PRIuZ " file%s changed",
+			stats->files_changed, stats->files_changed != 1 ? "s" : "");
+
+		if (stats->insertions || stats->deletions == 0)
+			git_buf_printf(
+				out, ", %" PRIuZ " insertion%s(+)",
+				stats->insertions, stats->insertions != 1 ? "s" : "");
+
+		if (stats->deletions || stats->insertions == 0)
+			git_buf_printf(
+				out, ", %" PRIuZ " deletion%s(-)",
+				stats->deletions, stats->deletions != 1 ? "s" : "");
+
+		git_buf_putc(out, '\n');
+
+		if (git_buf_oom(out))
+			return -1;
+	}
+
+	if (format & GIT_DIFF_STATS_INCLUDE_SUMMARY) {
+		for (i = 0; i < stats->files_changed; ++i) {
+			if ((delta = git_diff_get_delta(stats->diff, i)) == NULL)
+				continue;
+
+			error = git_diff_file_stats__summary_to_buf(out, delta);
+			if (error < 0)
+				return error;
+		}
+	}
+
+	return error;
+}
+
+void git_diff_stats_free(git_diff_stats *stats)
+{
+	if (stats == NULL)
+		return;
+
+	git_diff_free(stats->diff); /* bumped refcount in constructor */
+	git__free(stats->filestats);
+	git__free(stats);
+}

vendor/libgit2-sys/libgit2/src/diff_tform.c

diff --git a/vendor/libgit2-sys/libgit2/src/diff_tform.c b/vendor/libgit2-sys/libgit2/src/diff_tform.c
new file mode 100644
index 0000000..bc664dd
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/diff_tform.c
@@ -0,0 +1,1118 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "diff_tform.h"
+
+#include "git2/config.h"
+#include "git2/blob.h"
+#include "git2/sys/hashsig.h"
+
+#include "diff.h"
+#include "diff_generate.h"
+#include "path.h"
+#include "fileops.h"
+#include "config.h"
+
+git_diff_delta *git_diff__delta_dup(
+	const git_diff_delta *d, git_pool *pool)
+{
+	git_diff_delta *delta = git__malloc(sizeof(git_diff_delta));
+	if (!delta)
+		return NULL;
+
+	memcpy(delta, d, sizeof(git_diff_delta));
+	GIT_DIFF_FLAG__CLEAR_INTERNAL(delta->flags);
+
+	if (d->old_file.path != NULL) {
+		delta->old_file.path = git_pool_strdup(pool, d->old_file.path);
+		if (delta->old_file.path == NULL)
+			goto fail;
+	}
+
+	if (d->new_file.path != d->old_file.path && d->new_file.path != NULL) {
+		delta->new_file.path = git_pool_strdup(pool, d->new_file.path);
+		if (delta->new_file.path == NULL)
+			goto fail;
+	} else {
+		delta->new_file.path = delta->old_file.path;
+	}
+
+	return delta;
+
+fail:
+	git__free(delta);
+	return NULL;
+}
+
+git_diff_delta *git_diff__merge_like_cgit(
+	const git_diff_delta *a,
+	const git_diff_delta *b,
+	git_pool *pool)
+{
+	git_diff_delta *dup;
+
+	/* Emulate C git for merging two diffs (a la 'git diff <sha>').
+	 *
+	 * When C git does a diff between the work dir and a tree, it actually
+	 * diffs with the index but uses the workdir contents.  This emulates
+	 * those choices so we can emulate the type of diff.
+	 *
+	 * We have three file descriptions here, let's call them:
+	 *  f1 = a->old_file
+	 *  f2 = a->new_file AND b->old_file
+	 *  f3 = b->new_file
+	 */
+
+	/* If one of the diffs is a conflict, just dup it */
+	if (b->status == GIT_DELTA_CONFLICTED)
+		return git_diff__delta_dup(b, pool);
+	if (a->status == GIT_DELTA_CONFLICTED)
+		return git_diff__delta_dup(a, pool);
+
+	/* if f2 == f3 or f2 is deleted, then just dup the 'a' diff */
+	if (b->status == GIT_DELTA_UNMODIFIED || a->status == GIT_DELTA_DELETED)
+		return git_diff__delta_dup(a, pool);
+
+	/* otherwise, base this diff on the 'b' diff */
+	if ((dup = git_diff__delta_dup(b, pool)) == NULL)
+		return NULL;
+
+	/* If 'a' status is uninteresting, then we're done */
+	if (a->status == GIT_DELTA_UNMODIFIED ||
+		a->status == GIT_DELTA_UNTRACKED ||
+		a->status == GIT_DELTA_UNREADABLE)
+		return dup;
+
+	assert(b->status != GIT_DELTA_UNMODIFIED);
+
+	/* A cgit exception is that the diff of a file that is only in the
+	 * index (i.e. not in HEAD nor workdir) is given as empty.
+	 */
+	if (dup->status == GIT_DELTA_DELETED) {
+		if (a->status == GIT_DELTA_ADDED) {
+			dup->status = GIT_DELTA_UNMODIFIED;
+			dup->nfiles = 2;
+		}
+		/* else don't overwrite DELETE status */
+	} else {
+		dup->status = a->status;
+		dup->nfiles = a->nfiles;
+	}
+
+	git_oid_cpy(&dup->old_file.id, &a->old_file.id);
+	dup->old_file.mode  = a->old_file.mode;
+	dup->old_file.size  = a->old_file.size;
+	dup->old_file.flags = a->old_file.flags;
+
+	return dup;
+}
+
+int git_diff__merge(
+	git_diff *onto, const git_diff *from, git_diff__merge_cb cb)
+{
+	int error = 0;
+	git_pool onto_pool;
+	git_vector onto_new;
+	git_diff_delta *delta;
+	bool ignore_case, reversed;
+	unsigned int i, j;
+
+	assert(onto && from);
+
+	if (!from->deltas.length)
+		return 0;
+
+	ignore_case = ((onto->opts.flags & GIT_DIFF_IGNORE_CASE) != 0);
+	reversed    = ((onto->opts.flags & GIT_DIFF_REVERSE) != 0);
+
+	if (ignore_case != ((from->opts.flags & GIT_DIFF_IGNORE_CASE) != 0) ||
+		reversed    != ((from->opts.flags & GIT_DIFF_REVERSE) != 0)) {
+		giterr_set(GITERR_INVALID,
+			"attempt to merge diffs created with conflicting options");
+		return -1;
+	}
+
+	if (git_vector_init(&onto_new, onto->deltas.length, git_diff_delta__cmp) < 0)
+		return -1;
+
+	git_pool_init(&onto_pool, 1);
+
+	for (i = 0, j = 0; i < onto->deltas.length || j < from->deltas.length; ) {
+		git_diff_delta *o = GIT_VECTOR_GET(&onto->deltas, i);
+		const git_diff_delta *f = GIT_VECTOR_GET(&from->deltas, j);
+		int cmp = !f ? -1 : !o ? 1 :
+			STRCMP_CASESELECT(ignore_case, o->old_file.path, f->old_file.path);
+
+		if (cmp < 0) {
+			delta = git_diff__delta_dup(o, &onto_pool);
+			i++;
+		} else if (cmp > 0) {
+			delta = git_diff__delta_dup(f, &onto_pool);
+			j++;
+		} else {
+			const git_diff_delta *left = reversed ? f : o;
+			const git_diff_delta *right = reversed ? o : f;
+
+			delta = cb(left, right, &onto_pool);
+			i++;
+			j++;
+		}
+
+		/* the ignore rules for the target may not match the source
+		 * or the result of a merged delta could be skippable...
+		 */
+		if (delta && git_diff_delta__should_skip(&onto->opts, delta)) {
+			git__free(delta);
+			continue;
+		}
+
+		if ((error = !delta ? -1 : git_vector_insert(&onto_new, delta)) < 0)
+			break;
+	}
+
+	if (!error) {
+		git_vector_swap(&onto->deltas, &onto_new);
+		git_pool_swap(&onto->pool, &onto_pool);
+
+		if ((onto->opts.flags & GIT_DIFF_REVERSE) != 0)
+			onto->old_src = from->old_src;
+		else
+			onto->new_src = from->new_src;
+
+		/* prefix strings also come from old pool, so recreate those.*/
+		onto->opts.old_prefix =
+			git_pool_strdup_safe(&onto->pool, onto->opts.old_prefix);
+		onto->opts.new_prefix =
+			git_pool_strdup_safe(&onto->pool, onto->opts.new_prefix);
+	}
+
+	git_vector_free_deep(&onto_new);
+	git_pool_clear(&onto_pool);
+
+	return error;
+}
+
+int git_diff_merge(git_diff *onto, const git_diff *from)
+{
+	return git_diff__merge(onto, from, git_diff__merge_like_cgit);
+}
+
+int git_diff_find_similar__hashsig_for_file(
+	void **out, const git_diff_file *f, const char *path, void *p)
+{
+	git_hashsig_option_t opt = (git_hashsig_option_t)(intptr_t)p;
+
+	GIT_UNUSED(f);
+	return git_hashsig_create_fromfile((git_hashsig **)out, path, opt);
+}
+
+int git_diff_find_similar__hashsig_for_buf(
+	void **out, const git_diff_file *f, const char *buf, size_t len, void *p)
+{
+	git_hashsig_option_t opt = (git_hashsig_option_t)(intptr_t)p;
+
+	GIT_UNUSED(f);
+	return git_hashsig_create((git_hashsig **)out, buf, len, opt);
+}
+
+void git_diff_find_similar__hashsig_free(void *sig, void *payload)
+{
+	GIT_UNUSED(payload);
+	git_hashsig_free(sig);
+}
+
+int git_diff_find_similar__calc_similarity(
+	int *score, void *siga, void *sigb, void *payload)
+{
+	int error;
+
+	GIT_UNUSED(payload);
+	error = git_hashsig_compare(siga, sigb);
+	if (error < 0)
+		return error;
+
+	*score = error;
+	return 0;
+}
+
+#define DEFAULT_THRESHOLD 50
+#define DEFAULT_BREAK_REWRITE_THRESHOLD 60
+#define DEFAULT_RENAME_LIMIT 200
+
+static int normalize_find_opts(
+	git_diff *diff,
+	git_diff_find_options *opts,
+	const git_diff_find_options *given)
+{
+	git_config *cfg = NULL;
+	git_hashsig_option_t hashsig_opts;
+
+	GITERR_CHECK_VERSION(given, GIT_DIFF_FIND_OPTIONS_VERSION, "git_diff_find_options");
+
+	if (diff->repo != NULL &&
+		git_repository_config__weakptr(&cfg, diff->repo) < 0)
+		return -1;
+
+	if (given)
+		memcpy(opts, given, sizeof(*opts));
+
+	if (!given ||
+		 (given->flags & GIT_DIFF_FIND_ALL) == GIT_DIFF_FIND_BY_CONFIG)
+	{
+		if (cfg) {
+			char *rule =
+				git_config__get_string_force(cfg, "diff.renames", "true");
+			int boolval;
+
+			if (!git__parse_bool(&boolval, rule) && !boolval)
+				/* don't set FIND_RENAMES if bool value is false */;
+			else if (!strcasecmp(rule, "copies") || !strcasecmp(rule, "copy"))
+				opts->flags |= GIT_DIFF_FIND_RENAMES | GIT_DIFF_FIND_COPIES;
+			else
+				opts->flags |= GIT_DIFF_FIND_RENAMES;
+
+			git__free(rule);
+		} else {
+			/* set default flag */
+			opts->flags |= GIT_DIFF_FIND_RENAMES;
+		}
+	}
+
+	/* some flags imply others */
+
+	if (opts->flags & GIT_DIFF_FIND_EXACT_MATCH_ONLY) {
+		/* if we are only looking for exact matches, then don't turn
+		 * MODIFIED items into ADD/DELETE pairs because it's too picky
+		 */
+		opts->flags &= ~(GIT_DIFF_FIND_REWRITES | GIT_DIFF_BREAK_REWRITES);
+
+		/* similarly, don't look for self-rewrites to split */
+		opts->flags &= ~GIT_DIFF_FIND_RENAMES_FROM_REWRITES;
+	}
+
+	if (opts->flags & GIT_DIFF_FIND_RENAMES_FROM_REWRITES)
+		opts->flags |= GIT_DIFF_FIND_RENAMES;
+
+	if (opts->flags & GIT_DIFF_FIND_COPIES_FROM_UNMODIFIED)
+		opts->flags |= GIT_DIFF_FIND_COPIES;
+
+	if (opts->flags & GIT_DIFF_BREAK_REWRITES)
+		opts->flags |= GIT_DIFF_FIND_REWRITES;
+
+#define USE_DEFAULT(X) ((X) == 0 || (X) > 100)
+
+	if (USE_DEFAULT(opts->rename_threshold))
+		opts->rename_threshold = DEFAULT_THRESHOLD;
+
+	if (USE_DEFAULT(opts->rename_from_rewrite_threshold))
+		opts->rename_from_rewrite_threshold = DEFAULT_THRESHOLD;
+
+	if (USE_DEFAULT(opts->copy_threshold))
+		opts->copy_threshold = DEFAULT_THRESHOLD;
+
+	if (USE_DEFAULT(opts->break_rewrite_threshold))
+		opts->break_rewrite_threshold = DEFAULT_BREAK_REWRITE_THRESHOLD;
+
+#undef USE_DEFAULT
+
+	if (!opts->rename_limit) {
+		if (cfg) {
+			opts->rename_limit = git_config__get_int_force(
+				cfg, "diff.renamelimit", DEFAULT_RENAME_LIMIT);
+		}
+
+		if (opts->rename_limit <= 0)
+			opts->rename_limit = DEFAULT_RENAME_LIMIT;
+	}
+
+	/* assign the internal metric with whitespace flag as payload */
+	if (!opts->metric) {
+		opts->metric = git__malloc(sizeof(git_diff_similarity_metric));
+		GITERR_CHECK_ALLOC(opts->metric);
+
+		opts->metric->file_signature = git_diff_find_similar__hashsig_for_file;
+		opts->metric->buffer_signature = git_diff_find_similar__hashsig_for_buf;
+		opts->metric->free_signature = git_diff_find_similar__hashsig_free;
+		opts->metric->similarity = git_diff_find_similar__calc_similarity;
+
+		if (opts->flags & GIT_DIFF_FIND_IGNORE_WHITESPACE)
+			hashsig_opts = GIT_HASHSIG_IGNORE_WHITESPACE;
+		else if (opts->flags & GIT_DIFF_FIND_DONT_IGNORE_WHITESPACE)
+			hashsig_opts = GIT_HASHSIG_NORMAL;
+		else
+			hashsig_opts = GIT_HASHSIG_SMART_WHITESPACE;
+		hashsig_opts |= GIT_HASHSIG_ALLOW_SMALL_FILES;
+		opts->metric->payload = (void *)hashsig_opts;
+	}
+
+	return 0;
+}
+
+static int insert_delete_side_of_split(
+	git_diff *diff, git_vector *onto, const git_diff_delta *delta)
+{
+	/* make new record for DELETED side of split */
+	git_diff_delta *deleted = git_diff__delta_dup(delta, &diff->pool);
+	GITERR_CHECK_ALLOC(deleted);
+
+	deleted->status = GIT_DELTA_DELETED;
+	deleted->nfiles = 1;
+	memset(&deleted->new_file, 0, sizeof(deleted->new_file));
+	deleted->new_file.path = deleted->old_file.path;
+	deleted->new_file.flags |= GIT_DIFF_FLAG_VALID_ID;
+
+	return git_vector_insert(onto, deleted);
+}
+
+static int apply_splits_and_deletes(
+	git_diff *diff, size_t expected_size, bool actually_split)
+{
+	git_vector onto = GIT_VECTOR_INIT;
+	size_t i;
+	git_diff_delta *delta;
+
+	if (git_vector_init(&onto, expected_size, git_diff_delta__cmp) < 0)
+		return -1;
+
+	/* build new delta list without TO_DELETE and splitting TO_SPLIT */
+	git_vector_foreach(&diff->deltas, i, delta) {
+		if ((delta->flags & GIT_DIFF_FLAG__TO_DELETE) != 0)
+			continue;
+
+		if ((delta->flags & GIT_DIFF_FLAG__TO_SPLIT) != 0 && actually_split) {
+			delta->similarity = 0;
+
+			if (insert_delete_side_of_split(diff, &onto, delta) < 0)
+				goto on_error;
+
+			if (diff->new_src == GIT_ITERATOR_TYPE_WORKDIR)
+				delta->status = GIT_DELTA_UNTRACKED;
+			else
+				delta->status = GIT_DELTA_ADDED;
+			delta->nfiles = 1;
+			memset(&delta->old_file, 0, sizeof(delta->old_file));
+			delta->old_file.path = delta->new_file.path;
+			delta->old_file.flags |= GIT_DIFF_FLAG_VALID_ID;
+		}
+
+		/* clean up delta before inserting into new list */
+		GIT_DIFF_FLAG__CLEAR_INTERNAL(delta->flags);
+
+		if (delta->status != GIT_DELTA_COPIED &&
+			delta->status != GIT_DELTA_RENAMED &&
+			(delta->status != GIT_DELTA_MODIFIED || actually_split))
+			delta->similarity = 0;
+
+		/* insert into new list */
+		if (git_vector_insert(&onto, delta) < 0)
+			goto on_error;
+	}
+
+	/* cannot return an error past this point */
+
+	/* free deltas from old list that didn't make it to the new one */
+	git_vector_foreach(&diff->deltas, i, delta) {
+		if ((delta->flags & GIT_DIFF_FLAG__TO_DELETE) != 0)
+			git__free(delta);
+	}
+
+	/* swap new delta list into place */
+	git_vector_swap(&diff->deltas, &onto);
+	git_vector_free(&onto);
+	git_vector_sort(&diff->deltas);
+
+	return 0;
+
+on_error:
+	git_vector_free_deep(&onto);
+
+	return -1;
+}
+
+GIT_INLINE(git_diff_file *) similarity_get_file(git_diff *diff, size_t idx)
+{
+	git_diff_delta *delta = git_vector_get(&diff->deltas, idx / 2);
+	return (idx & 1) ? &delta->new_file : &delta->old_file;
+}
+
+typedef struct {
+	size_t idx;
+	git_iterator_type_t src;
+	git_repository *repo;
+	git_diff_file *file;
+	git_buf data;
+	git_odb_object *odb_obj;
+	git_blob *blob;
+} similarity_info;
+
+static int similarity_init(
+	similarity_info *info, git_diff *diff, size_t file_idx)
+{
+	info->idx  = file_idx;
+	info->src  = (file_idx & 1) ? diff->new_src : diff->old_src;
+	info->repo = diff->repo;
+	info->file = similarity_get_file(diff, file_idx);
+	info->odb_obj = NULL;
+	info->blob = NULL;
+	git_buf_init(&info->data, 0);
+
+	if (info->file->size > 0 || info->src == GIT_ITERATOR_TYPE_WORKDIR)
+		return 0;
+
+	return git_diff_file__resolve_zero_size(
+		info->file, &info->odb_obj, info->repo);
+}
+
+static int similarity_sig(
+	similarity_info *info,
+	const git_diff_find_options *opts,
+	void **cache)
+{
+	int error = 0;
+	git_diff_file *file = info->file;
+
+	if (info->src == GIT_ITERATOR_TYPE_WORKDIR) {
+		if ((error = git_buf_joinpath(
+			&info->data, git_repository_workdir(info->repo), file->path)) < 0)
+			return error;
+
+		/* if path is not a regular file, just skip this item */
+		if (!git_path_isfile(info->data.ptr))
+			return 0;
+
+		/* TODO: apply wd-to-odb filters to file data if necessary */
+
+		error = opts->metric->file_signature(
+			&cache[info->idx], info->file,
+			info->data.ptr, opts->metric->payload);
+	} else {
+		/* if we didn't initially know the size, we might have an odb_obj
+		 * around from earlier, so convert that, otherwise load the blob now
+		 */
+		if (info->odb_obj != NULL)
+			error = git_object__from_odb_object(
+				(git_object **)&info->blob, info->repo,
+				info->odb_obj, GIT_OBJ_BLOB);
+		else
+			error = git_blob_lookup(&info->blob, info->repo, &file->id);
+
+		if (error < 0) {
+			/* if lookup fails, just skip this item in similarity calc */
+			giterr_clear();
+		} else {
+			size_t sz;
+
+			/* index size may not be actual blob size if filtered */
+			if (file->size != git_blob_rawsize(info->blob))
+				file->size = git_blob_rawsize(info->blob);
+
+			sz = (size_t)(git__is_sizet(file->size) ? file->size : -1);
+
+			error = opts->metric->buffer_signature(
+				&cache[info->idx], info->file,
+				git_blob_rawcontent(info->blob), sz, opts->metric->payload);
+		}
+	}
+
+	return error;
+}
+
+static void similarity_unload(similarity_info *info)
+{
+	if (info->odb_obj)
+		git_odb_object_free(info->odb_obj);
+
+	if (info->blob)
+		git_blob_free(info->blob);
+	else
+		git_buf_free(&info->data);
+}
+
+#define FLAG_SET(opts,flag_name) (((opts)->flags & flag_name) != 0)
+
+/* - score < 0 means files cannot be compared
+ * - score >= 100 means files are exact match
+ * - score == 0 means files are completely different
+ */
+static int similarity_measure(
+	int *score,
+	git_diff *diff,
+	const git_diff_find_options *opts,
+	void **cache,
+	size_t a_idx,
+	size_t b_idx)
+{
+	git_diff_file *a_file = similarity_get_file(diff, a_idx);
+	git_diff_file *b_file = similarity_get_file(diff, b_idx);
+	bool exact_match = FLAG_SET(opts, GIT_DIFF_FIND_EXACT_MATCH_ONLY);
+	int error = 0;
+	similarity_info a_info, b_info;
+
+	*score = -1;
+
+	/* don't try to compare things that aren't files */
+	if (!GIT_MODE_ISBLOB(a_file->mode) || !GIT_MODE_ISBLOB(b_file->mode))
+		return 0;
+
+	/* if exact match is requested, force calculation of missing OIDs now */
+	if (exact_match) {
+		if (git_oid_iszero(&a_file->id) &&
+			diff->old_src == GIT_ITERATOR_TYPE_WORKDIR &&
+			!git_diff__oid_for_file(&a_file->id,
+				diff, a_file->path, a_file->mode, a_file->size))
+			a_file->flags |= GIT_DIFF_FLAG_VALID_ID;
+
+		if (git_oid_iszero(&b_file->id) &&
+			diff->new_src == GIT_ITERATOR_TYPE_WORKDIR &&
+			!git_diff__oid_for_file(&b_file->id,
+				diff, b_file->path, b_file->mode, b_file->size))
+			b_file->flags |= GIT_DIFF_FLAG_VALID_ID;
+	}
+
+	/* check OID match as a quick test */
+	if (git_oid__cmp(&a_file->id, &b_file->id) == 0) {
+		*score = 100;
+		return 0;
+	}
+
+	/* don't calculate signatures if we are doing exact match */
+	if (exact_match) {
+		*score = 0;
+		return 0;
+	}
+
+	memset(&a_info, 0, sizeof(a_info));
+	memset(&b_info, 0, sizeof(b_info));
+
+	/* set up similarity data (will try to update missing file sizes) */
+	if (!cache[a_idx] && (error = similarity_init(&a_info, diff, a_idx)) < 0)
+		return error;
+	if (!cache[b_idx] && (error = similarity_init(&b_info, diff, b_idx)) < 0)
+		goto cleanup;
+
+	/* check if file sizes are nowhere near each other */
+	if (a_file->size > 127 &&
+		b_file->size > 127 &&
+		(a_file->size > (b_file->size << 3) ||
+		 b_file->size > (a_file->size << 3)))
+		goto cleanup;
+
+	/* update signature cache if needed */
+	if (!cache[a_idx]) {
+		if ((error = similarity_sig(&a_info, opts, cache)) < 0)
+			goto cleanup;
+	}
+	if (!cache[b_idx]) {
+		if ((error = similarity_sig(&b_info, opts, cache)) < 0)
+			goto cleanup;
+	}
+
+	/* calculate similarity provided that the metric choose to process
+	 * both the a and b files (some may not if file is too big, etc).
+	 */
+	if (cache[a_idx] && cache[b_idx])
+		error = opts->metric->similarity(
+			score, cache[a_idx], cache[b_idx], opts->metric->payload);
+
+cleanup:
+	similarity_unload(&a_info);
+	similarity_unload(&b_info);
+
+	return error;
+}
+
+static int calc_self_similarity(
+	git_diff *diff,
+	const git_diff_find_options *opts,
+	size_t delta_idx,
+	void **cache)
+{
+	int error, similarity = -1;
+	git_diff_delta *delta = GIT_VECTOR_GET(&diff->deltas, delta_idx);
+
+	if ((delta->flags & GIT_DIFF_FLAG__HAS_SELF_SIMILARITY) != 0)
+		return 0;
+
+	error = similarity_measure(
+		&similarity, diff, opts, cache, 2 * delta_idx, 2 * delta_idx + 1);
+	if (error < 0)
+		return error;
+
+	if (similarity >= 0) {
+		delta->similarity = (uint16_t)similarity;
+		delta->flags |= GIT_DIFF_FLAG__HAS_SELF_SIMILARITY;
+	}
+
+	return 0;
+}
+
+static bool is_rename_target(
+	git_diff *diff,
+	const git_diff_find_options *opts,
+	size_t delta_idx,
+	void **cache)
+{
+	git_diff_delta *delta = GIT_VECTOR_GET(&diff->deltas, delta_idx);
+
+	/* skip things that aren't plain blobs */
+	if (!GIT_MODE_ISBLOB(delta->new_file.mode))
+		return false;
+
+	/* only consider ADDED, RENAMED, COPIED, and split MODIFIED as
+	 * targets; maybe include UNTRACKED if requested.
+	 */
+	switch (delta->status) {
+	case GIT_DELTA_UNMODIFIED:
+	case GIT_DELTA_DELETED:
+	case GIT_DELTA_IGNORED:
+	case GIT_DELTA_CONFLICTED:
+		return false;
+
+	case GIT_DELTA_MODIFIED:
+		if (!FLAG_SET(opts, GIT_DIFF_FIND_REWRITES) &&
+			!FLAG_SET(opts, GIT_DIFF_FIND_RENAMES_FROM_REWRITES))
+			return false;
+
+		if (calc_self_similarity(diff, opts, delta_idx, cache) < 0)
+			return false;
+
+		if (FLAG_SET(opts, GIT_DIFF_BREAK_REWRITES) &&
+			delta->similarity < opts->break_rewrite_threshold) {
+			delta->flags |= GIT_DIFF_FLAG__TO_SPLIT;
+			break;
+		}
+		if (FLAG_SET(opts, GIT_DIFF_FIND_RENAMES_FROM_REWRITES) &&
+			delta->similarity < opts->rename_from_rewrite_threshold) {
+			delta->flags |= GIT_DIFF_FLAG__TO_SPLIT;
+			break;
+		}
+
+		return false;
+
+	case GIT_DELTA_UNTRACKED:
+		if (!FLAG_SET(opts, GIT_DIFF_FIND_FOR_UNTRACKED))
+			return false;
+		break;
+
+	default: /* all other status values should be checked */
+		break;
+	}
+
+	delta->flags |= GIT_DIFF_FLAG__IS_RENAME_TARGET;
+	return true;
+}
+
+static bool is_rename_source(
+	git_diff *diff,
+	const git_diff_find_options *opts,
+	size_t delta_idx,
+	void **cache)
+{
+	git_diff_delta *delta = GIT_VECTOR_GET(&diff->deltas, delta_idx);
+
+	/* skip things that aren't blobs */
+	if (!GIT_MODE_ISBLOB(delta->old_file.mode))
+		return false;
+
+	switch (delta->status) {
+	case GIT_DELTA_ADDED:
+	case GIT_DELTA_UNTRACKED:
+	case GIT_DELTA_UNREADABLE:
+	case GIT_DELTA_IGNORED:
+	case GIT_DELTA_CONFLICTED:
+		return false;
+
+	case GIT_DELTA_DELETED:
+	case GIT_DELTA_TYPECHANGE:
+		break;
+
+	case GIT_DELTA_UNMODIFIED:
+		if (!FLAG_SET(opts, GIT_DIFF_FIND_COPIES_FROM_UNMODIFIED))
+			return false;
+		if (FLAG_SET(opts, GIT_DIFF_FIND_REMOVE_UNMODIFIED))
+			delta->flags |= GIT_DIFF_FLAG__TO_DELETE;
+		break;
+
+	default: /* MODIFIED, RENAMED, COPIED */
+		/* if we're finding copies, this could be a source */
+		if (FLAG_SET(opts, GIT_DIFF_FIND_COPIES))
+			break;
+
+		/* otherwise, this is only a source if we can split it */
+		if (!FLAG_SET(opts, GIT_DIFF_FIND_REWRITES) &&
+			!FLAG_SET(opts, GIT_DIFF_FIND_RENAMES_FROM_REWRITES))
+			return false;
+
+		if (calc_self_similarity(diff, opts, delta_idx, cache) < 0)
+			return false;
+
+		if (FLAG_SET(opts, GIT_DIFF_BREAK_REWRITES) &&
+			delta->similarity < opts->break_rewrite_threshold) {
+			delta->flags |= GIT_DIFF_FLAG__TO_SPLIT;
+			break;
+		}
+
+		if (FLAG_SET(opts, GIT_DIFF_FIND_RENAMES_FROM_REWRITES) &&
+			delta->similarity < opts->rename_from_rewrite_threshold)
+			break;
+
+		return false;
+	}
+
+	delta->flags |= GIT_DIFF_FLAG__IS_RENAME_SOURCE;
+	return true;
+}
+
+GIT_INLINE(bool) delta_is_split(git_diff_delta *delta)
+{
+	return (delta->status == GIT_DELTA_TYPECHANGE ||
+			(delta->flags & GIT_DIFF_FLAG__TO_SPLIT) != 0);
+}
+
+GIT_INLINE(bool) delta_is_new_only(git_diff_delta *delta)
+{
+	return (delta->status == GIT_DELTA_ADDED ||
+			delta->status == GIT_DELTA_UNTRACKED ||
+			delta->status == GIT_DELTA_UNREADABLE ||
+			delta->status == GIT_DELTA_IGNORED);
+}
+
+GIT_INLINE(void) delta_make_rename(
+	git_diff_delta *to, const git_diff_delta *from, uint16_t similarity)
+{
+	to->status     = GIT_DELTA_RENAMED;
+	to->similarity = similarity;
+	to->nfiles     = 2;
+	memcpy(&to->old_file, &from->old_file, sizeof(to->old_file));
+	to->flags &= ~GIT_DIFF_FLAG__TO_SPLIT;
+}
+
+typedef struct {
+	size_t   idx;
+	uint16_t similarity;
+} diff_find_match;
+
+int git_diff_find_similar(
+	git_diff *diff,
+	const git_diff_find_options *given_opts)
+{
+	size_t s, t;
+	int error = 0, result;
+	uint16_t similarity;
+	git_diff_delta *src, *tgt;
+	git_diff_find_options opts = GIT_DIFF_FIND_OPTIONS_INIT;
+	size_t num_deltas, num_srcs = 0, num_tgts = 0;
+	size_t tried_srcs = 0, tried_tgts = 0;
+	size_t num_rewrites = 0, num_updates = 0, num_bumped = 0;
+	size_t sigcache_size;
+	void **sigcache = NULL; /* cache of similarity metric file signatures */
+	diff_find_match *tgt2src = NULL;
+	diff_find_match *src2tgt = NULL;
+	diff_find_match *tgt2src_copy = NULL;
+	diff_find_match *best_match;
+	git_diff_file swap;
+
+	if ((error = normalize_find_opts(diff, &opts, given_opts)) < 0)
+		return error;
+
+	num_deltas = diff->deltas.length;
+
+	/* TODO: maybe abort if deltas.length > rename_limit ??? */
+	if (!git__is_uint32(num_deltas))
+		goto cleanup;
+
+	/* No flags set; nothing to do */
+	if ((opts.flags & GIT_DIFF_FIND_ALL) == 0)
+		goto cleanup;
+
+	GITERR_CHECK_ALLOC_MULTIPLY(&sigcache_size, num_deltas, 2);
+	sigcache = git__calloc(sigcache_size, sizeof(void *));
+	GITERR_CHECK_ALLOC(sigcache);
+
+	/* Label rename sources and targets
+	 *
+	 * This will also set self-similarity scores for MODIFIED files and
+	 * mark them for splitting if break-rewrites is enabled
+	 */
+	git_vector_foreach(&diff->deltas, t, tgt) {
+		if (is_rename_source(diff, &opts, t, sigcache))
+			++num_srcs;
+
+		if (is_rename_target(diff, &opts, t, sigcache))
+			++num_tgts;
+
+		if ((tgt->flags & GIT_DIFF_FLAG__TO_SPLIT) != 0)
+			num_rewrites++;
+	}
+
+	/* if there are no candidate srcs or tgts, we're done */
+	if (!num_srcs || !num_tgts)
+		goto cleanup;
+
+	src2tgt = git__calloc(num_deltas, sizeof(diff_find_match));
+	GITERR_CHECK_ALLOC(src2tgt);
+	tgt2src = git__calloc(num_deltas, sizeof(diff_find_match));
+	GITERR_CHECK_ALLOC(tgt2src);
+
+	if (FLAG_SET(&opts, GIT_DIFF_FIND_COPIES)) {
+		tgt2src_copy = git__calloc(num_deltas, sizeof(diff_find_match));
+		GITERR_CHECK_ALLOC(tgt2src_copy);
+	}
+
+	/*
+	 * Find best-fit matches for rename / copy candidates
+	 */
+
+find_best_matches:
+	tried_tgts = num_bumped = 0;
+
+	git_vector_foreach(&diff->deltas, t, tgt) {
+		/* skip things that are not rename targets */
+		if ((tgt->flags & GIT_DIFF_FLAG__IS_RENAME_TARGET) == 0)
+			continue;
+
+		tried_srcs = 0;
+
+		git_vector_foreach(&diff->deltas, s, src) {
+			/* skip things that are not rename sources */
+			if ((src->flags & GIT_DIFF_FLAG__IS_RENAME_SOURCE) == 0)
+				continue;
+
+			/* calculate similarity for this pair and find best match */
+			if (s == t)
+				result = -1; /* don't measure self-similarity here */
+			else if ((error = similarity_measure(
+				&result, diff, &opts, sigcache, 2 * s, 2 * t + 1)) < 0)
+				goto cleanup;
+
+			if (result < 0)
+				continue;
+			similarity = (uint16_t)result;
+
+			/* is this a better rename? */
+			if (tgt2src[t].similarity < similarity &&
+				src2tgt[s].similarity < similarity)
+			{
+				/* eject old mapping */
+				if (src2tgt[s].similarity > 0) {
+					tgt2src[src2tgt[s].idx].similarity = 0;
+					num_bumped++;
+				}
+				if (tgt2src[t].similarity > 0) {
+					src2tgt[tgt2src[t].idx].similarity = 0;
+					num_bumped++;
+				}
+
+				/* write new mapping */
+				tgt2src[t].idx = s;
+				tgt2src[t].similarity = similarity;
+				src2tgt[s].idx = t;
+				src2tgt[s].similarity = similarity;
+			}
+
+			/* keep best absolute match for copies */
+			if (tgt2src_copy != NULL &&
+				tgt2src_copy[t].similarity < similarity)
+			{
+				tgt2src_copy[t].idx = s;
+				tgt2src_copy[t].similarity = similarity;
+			}
+
+			if (++tried_srcs >= num_srcs)
+				break;
+
+			/* cap on maximum targets we'll examine (per "tgt" file) */
+			if (tried_srcs > opts.rename_limit)
+				break;
+		}
+
+		if (++tried_tgts >= num_tgts)
+			break;
+	}
+
+	if (num_bumped > 0) /* try again if we bumped some items */
+		goto find_best_matches;
+
+	/*
+	 * Rewrite the diffs with renames / copies
+	 */
+
+	git_vector_foreach(&diff->deltas, t, tgt) {
+		/* skip things that are not rename targets */
+		if ((tgt->flags & GIT_DIFF_FLAG__IS_RENAME_TARGET) == 0)
+			continue;
+
+		/* check if this delta was the target of a similarity */
+		if (tgt2src[t].similarity)
+			best_match = &tgt2src[t];
+		else if (tgt2src_copy && tgt2src_copy[t].similarity)
+			best_match = &tgt2src_copy[t];
+		else
+			continue;
+
+		s = best_match->idx;
+		src = GIT_VECTOR_GET(&diff->deltas, s);
+
+		/* possible scenarios:
+		 * 1. from DELETE to ADD/UNTRACK/IGNORE = RENAME
+		 * 2. from DELETE to SPLIT/TYPECHANGE = RENAME + DELETE
+		 * 3. from SPLIT/TYPECHANGE to ADD/UNTRACK/IGNORE = ADD + RENAME
+		 * 4. from SPLIT/TYPECHANGE to SPLIT/TYPECHANGE = RENAME + SPLIT
+		 * 5. from OTHER to ADD/UNTRACK/IGNORE = OTHER + COPY
+		 */
+
+		if (src->status == GIT_DELTA_DELETED) {
+
+			if (delta_is_new_only(tgt)) {
+
+				if (best_match->similarity < opts.rename_threshold)
+					continue;
+
+				delta_make_rename(tgt, src, best_match->similarity);
+
+				src->flags |= GIT_DIFF_FLAG__TO_DELETE;
+				num_rewrites++;
+			} else {
+				assert(delta_is_split(tgt));
+
+				if (best_match->similarity < opts.rename_from_rewrite_threshold)
+					continue;
+
+				memcpy(&swap, &tgt->old_file, sizeof(swap));
+
+				delta_make_rename(tgt, src, best_match->similarity);
+				num_rewrites--;
+
+				assert(src->status == GIT_DELTA_DELETED);
+				memcpy(&src->old_file, &swap, sizeof(src->old_file));
+				memset(&src->new_file, 0, sizeof(src->new_file));
+				src->new_file.path = src->old_file.path;
+				src->new_file.flags |= GIT_DIFF_FLAG_VALID_ID;
+
+				num_updates++;
+
+				if (src2tgt[t].similarity > 0 && src2tgt[t].idx > t) {
+					/* what used to be at src t is now at src s */
+					tgt2src[src2tgt[t].idx].idx = s;
+				}
+			}
+		}
+
+		else if (delta_is_split(src)) {
+
+			if (delta_is_new_only(tgt)) {
+
+				if (best_match->similarity < opts.rename_threshold)
+					continue;
+
+				delta_make_rename(tgt, src, best_match->similarity);
+
+				src->status = (diff->new_src == GIT_ITERATOR_TYPE_WORKDIR) ?
+					GIT_DELTA_UNTRACKED : GIT_DELTA_ADDED;
+				src->nfiles = 1;
+				memset(&src->old_file, 0, sizeof(src->old_file));
+				src->old_file.path = src->new_file.path;
+				src->old_file.flags |= GIT_DIFF_FLAG_VALID_ID;
+
+				src->flags &= ~GIT_DIFF_FLAG__TO_SPLIT;
+				num_rewrites--;
+
+				num_updates++;
+			} else {
+				assert(delta_is_split(src));
+
+				if (best_match->similarity < opts.rename_from_rewrite_threshold)
+					continue;
+
+				memcpy(&swap, &tgt->old_file, sizeof(swap));
+
+				delta_make_rename(tgt, src, best_match->similarity);
+				num_rewrites--;
+				num_updates++;
+
+				memcpy(&src->old_file, &swap, sizeof(src->old_file));
+
+				/* if we've just swapped the new element into the correct
+				 * place, clear the SPLIT flag
+				 */
+				if (tgt2src[s].idx == t &&
+					tgt2src[s].similarity >
+					opts.rename_from_rewrite_threshold) {
+					src->status     = GIT_DELTA_RENAMED;
+					src->similarity = tgt2src[s].similarity;
+					tgt2src[s].similarity = 0;
+					src->flags &= ~GIT_DIFF_FLAG__TO_SPLIT;
+					num_rewrites--;
+				}
+				/* otherwise, if we just overwrote a source, update mapping */
+				else if (src2tgt[t].similarity > 0 && src2tgt[t].idx > t) {
+					/* what used to be at src t is now at src s */
+					tgt2src[src2tgt[t].idx].idx = s;
+				}
+
+				num_updates++;
+			}
+		}
+
+		else if (FLAG_SET(&opts, GIT_DIFF_FIND_COPIES)) {
+			if (tgt2src_copy[t].similarity < opts.copy_threshold)
+				continue;
+
+			/* always use best possible source for copy */
+			best_match = &tgt2src_copy[t];
+			src = GIT_VECTOR_GET(&diff->deltas, best_match->idx);
+
+			if (delta_is_split(tgt)) {
+				error = insert_delete_side_of_split(diff, &diff->deltas, tgt);
+				if (error < 0)
+					goto cleanup;
+				num_rewrites--;
+			}
+
+			if (!delta_is_split(tgt) && !delta_is_new_only(tgt))
+				continue;
+
+			tgt->status     = GIT_DELTA_COPIED;
+			tgt->similarity = best_match->similarity;
+			tgt->nfiles     = 2;
+			memcpy(&tgt->old_file, &src->old_file, sizeof(tgt->old_file));
+			tgt->flags &= ~GIT_DIFF_FLAG__TO_SPLIT;
+
+			num_updates++;
+		}
+	}
+
+	/*
+	 * Actually split and delete entries as needed
+	 */
+
+	if (num_rewrites > 0 || num_updates > 0)
+		error = apply_splits_and_deletes(
+			diff, diff->deltas.length - num_rewrites,
+			FLAG_SET(&opts, GIT_DIFF_BREAK_REWRITES) &&
+			!FLAG_SET(&opts, GIT_DIFF_BREAK_REWRITES_FOR_RENAMES_ONLY));
+
+cleanup:
+	git__free(tgt2src);
+	git__free(src2tgt);
+	git__free(tgt2src_copy);
+
+	if (sigcache) {
+		for (t = 0; t < num_deltas * 2; ++t) {
+			if (sigcache[t] != NULL)
+				opts.metric->free_signature(sigcache[t], opts.metric->payload);
+		}
+		git__free(sigcache);
+	}
+
+	if (!given_opts || !given_opts->metric)
+		git__free(opts.metric);
+
+	return error;
+}
+
+#undef FLAG_SET

vendor/libgit2-sys/libgit2/src/diff_tform.h

diff --git a/vendor/libgit2-sys/libgit2/src/diff_tform.h b/vendor/libgit2-sys/libgit2/src/diff_tform.h
new file mode 100644
index 0000000..7abb8b3
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/diff_tform.h
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_diff_tform_h__
+#define INCLUDE_diff_tform_h__
+
+#include "common.h"
+
+#include "diff_file.h"
+
+extern int git_diff_find_similar__hashsig_for_file(
+	void **out, const git_diff_file *f, const char *path, void *p);
+
+extern int git_diff_find_similar__hashsig_for_buf(
+	void **out, const git_diff_file *f, const char *buf, size_t len, void *p);
+
+extern void git_diff_find_similar__hashsig_free(void *sig, void *payload);
+
+extern int git_diff_find_similar__calc_similarity(
+	int *score, void *siga, void *sigb, void *payload);
+
+#endif

vendor/libgit2-sys/libgit2/src/diff_xdiff.c

diff --git a/vendor/libgit2-sys/libgit2/src/diff_xdiff.c b/vendor/libgit2-sys/libgit2/src/diff_xdiff.c
new file mode 100644
index 0000000..6907e52
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/diff_xdiff.c
@@ -0,0 +1,263 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "diff_xdiff.h"
+#include "util.h"
+
+#include "git2/errors.h"
+#include "diff.h"
+#include "diff_driver.h"
+#include "patch_generate.h"
+
+static int git_xdiff_scan_int(const char **str, int *value)
+{
+	const char *scan = *str;
+	int v = 0, digits = 0;
+	/* find next digit */
+	for (scan = *str; *scan && !git__isdigit(*scan); scan++);
+	/* parse next number */
+	for (; git__isdigit(*scan); scan++, digits++)
+		v = (v * 10) + (*scan - '0');
+	*str = scan;
+	*value = v;
+	return (digits > 0) ? 0 : -1;
+}
+
+static int git_xdiff_parse_hunk(git_diff_hunk *hunk, const char *header)
+{
+	/* expect something of the form "@@ -%d[,%d] +%d[,%d] @@" */
+	if (*header != '@')
+		goto fail;
+	if (git_xdiff_scan_int(&header, &hunk->old_start) < 0)
+		goto fail;
+	if (*header == ',') {
+		if (git_xdiff_scan_int(&header, &hunk->old_lines) < 0)
+			goto fail;
+	} else
+		hunk->old_lines = 1;
+	if (git_xdiff_scan_int(&header, &hunk->new_start) < 0)
+		goto fail;
+	if (*header == ',') {
+		if (git_xdiff_scan_int(&header, &hunk->new_lines) < 0)
+			goto fail;
+	} else
+		hunk->new_lines = 1;
+	if (hunk->old_start < 0 || hunk->new_start < 0)
+		goto fail;
+
+	return 0;
+
+fail:
+	giterr_set(GITERR_INVALID, "malformed hunk header from xdiff");
+	return -1;
+}
+
+typedef struct {
+	git_xdiff_output *xo;
+	git_patch_generated *patch;
+	git_diff_hunk hunk;
+	int old_lineno, new_lineno;
+	mmfile_t xd_old_data, xd_new_data;
+} git_xdiff_info;
+
+static int diff_update_lines(
+	git_xdiff_info *info,
+	git_diff_line *line,
+	const char *content,
+	size_t content_len)
+{
+	const char *scan = content, *scan_end = content + content_len;
+
+	for (line->num_lines = 0; scan < scan_end; ++scan)
+		if (*scan == '\n')
+			++line->num_lines;
+
+	line->content     = content;
+	line->content_len = content_len;
+
+	/* expect " "/"-"/"+", then data */
+	switch (line->origin) {
+	case GIT_DIFF_LINE_ADDITION:
+	case GIT_DIFF_LINE_DEL_EOFNL:
+		line->old_lineno = -1;
+		line->new_lineno = info->new_lineno;
+		info->new_lineno += (int)line->num_lines;
+		break;
+	case GIT_DIFF_LINE_DELETION:
+	case GIT_DIFF_LINE_ADD_EOFNL:
+		line->old_lineno = info->old_lineno;
+		line->new_lineno = -1;
+		info->old_lineno += (int)line->num_lines;
+		break;
+	case GIT_DIFF_LINE_CONTEXT:
+	case GIT_DIFF_LINE_CONTEXT_EOFNL:
+		line->old_lineno = info->old_lineno;
+		line->new_lineno = info->new_lineno;
+		info->old_lineno += (int)line->num_lines;
+		info->new_lineno += (int)line->num_lines;
+		break;
+	default:
+		giterr_set(GITERR_INVALID, "unknown diff line origin %02x",
+			(unsigned int)line->origin);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int git_xdiff_cb(void *priv, mmbuffer_t *bufs, int len)
+{
+	git_xdiff_info *info = priv;
+	git_patch_generated *patch = info->patch;
+	const git_diff_delta *delta = patch->base.delta;
+	git_patch_generated_output *output = &info->xo->output;
+	git_diff_line line;
+	size_t buffer_len;
+
+	if (len == 1) {
+		output->error = git_xdiff_parse_hunk(&info->hunk, bufs[0].ptr);
+		if (output->error < 0)
+			return output->error;
+
+		info->hunk.header_len = bufs[0].size;
+		if (info->hunk.header_len >= sizeof(info->hunk.header))
+			info->hunk.header_len = sizeof(info->hunk.header) - 1;
+
+		/* Sanitize the hunk header in case there is invalid Unicode */
+		buffer_len = git__utf8_valid_buf_length((const uint8_t *) bufs[0].ptr, info->hunk.header_len);
+		/* Sanitizing the hunk header may delete the newline, so add it back again if there is room */
+		if (buffer_len < info->hunk.header_len) {
+			bufs[0].ptr[buffer_len] = '\n';
+			buffer_len += 1;
+			info->hunk.header_len = buffer_len;
+		}
+
+		memcpy(info->hunk.header, bufs[0].ptr, info->hunk.header_len);
+		info->hunk.header[info->hunk.header_len] = '\0';
+
+		if (output->hunk_cb != NULL &&
+			(output->error = output->hunk_cb(
+				delta, &info->hunk, output->payload)))
+			return output->error;
+
+		info->old_lineno = info->hunk.old_start;
+		info->new_lineno = info->hunk.new_start;
+	}
+
+	if (len == 2 || len == 3) {
+		/* expect " "/"-"/"+", then data */
+		line.origin =
+			(*bufs[0].ptr == '+') ? GIT_DIFF_LINE_ADDITION :
+			(*bufs[0].ptr == '-') ? GIT_DIFF_LINE_DELETION :
+			GIT_DIFF_LINE_CONTEXT;
+
+		if (line.origin == GIT_DIFF_LINE_ADDITION)
+			line.content_offset = bufs[1].ptr - info->xd_new_data.ptr;
+		else if (line.origin == GIT_DIFF_LINE_DELETION)
+			line.content_offset = bufs[1].ptr - info->xd_old_data.ptr;
+		else
+			line.content_offset = -1;
+
+		output->error = diff_update_lines(
+			info, &line, bufs[1].ptr, bufs[1].size);
+
+		if (!output->error && output->data_cb != NULL)
+			output->error = output->data_cb(
+				delta, &info->hunk, &line, output->payload);
+	}
+
+	if (len == 3 && !output->error) {
+		/* If we have a '+' and a third buf, then we have added a line
+		 * without a newline and the old code had one, so DEL_EOFNL.
+		 * If we have a '-' and a third buf, then we have removed a line
+		 * with out a newline but added a blank line, so ADD_EOFNL.
+		 */
+		line.origin =
+			(*bufs[0].ptr == '+') ? GIT_DIFF_LINE_DEL_EOFNL :
+			(*bufs[0].ptr == '-') ? GIT_DIFF_LINE_ADD_EOFNL :
+			GIT_DIFF_LINE_CONTEXT_EOFNL;
+
+		line.content_offset = -1;
+
+		output->error = diff_update_lines(
+			info, &line, bufs[2].ptr, bufs[2].size);
+
+		if (!output->error && output->data_cb != NULL)
+			output->error = output->data_cb(
+				delta, &info->hunk, &line, output->payload);
+	}
+
+	return output->error;
+}
+
+static int git_xdiff(git_patch_generated_output *output, git_patch_generated *patch)
+{
+	git_xdiff_output *xo = (git_xdiff_output *)output;
+	git_xdiff_info info;
+	git_diff_find_context_payload findctxt;
+
+	memset(&info, 0, sizeof(info));
+	info.patch = patch;
+	info.xo    = xo;
+
+	xo->callback.priv = &info;
+
+	git_diff_find_context_init(
+		&xo->config.find_func, &findctxt, git_patch_generated_driver(patch));
+	xo->config.find_func_priv = &findctxt;
+
+	if (xo->config.find_func != NULL)
+		xo->config.flags |= XDL_EMIT_FUNCNAMES;
+	else
+		xo->config.flags &= ~XDL_EMIT_FUNCNAMES;
+
+	/* TODO: check ofile.opts_flags to see if driver-specific per-file
+	 * updates are needed to xo->params.flags
+	 */
+
+	git_patch_generated_old_data(&info.xd_old_data.ptr, &info.xd_old_data.size, patch);
+	git_patch_generated_new_data(&info.xd_new_data.ptr, &info.xd_new_data.size, patch);
+
+	if (info.xd_old_data.size > GIT_XDIFF_MAX_SIZE ||
+		info.xd_new_data.size > GIT_XDIFF_MAX_SIZE) {
+		giterr_set(GITERR_INVALID, "files too large for diff");
+		return -1;
+	}
+
+	xdl_diff(&info.xd_old_data, &info.xd_new_data,
+		&xo->params, &xo->config, &xo->callback);
+
+	git_diff_find_context_clear(&findctxt);
+
+	return xo->output.error;
+}
+
+void git_xdiff_init(git_xdiff_output *xo, const git_diff_options *opts)
+{
+	uint32_t flags = opts ? opts->flags : 0;
+
+	xo->output.diff_cb = git_xdiff;
+
+	xo->config.ctxlen = opts ? opts->context_lines : 3;
+	xo->config.interhunkctxlen = opts ? opts->interhunk_lines : 0;
+
+	if (flags & GIT_DIFF_IGNORE_WHITESPACE)
+		xo->params.flags |= XDF_WHITESPACE_FLAGS;
+	if (flags & GIT_DIFF_IGNORE_WHITESPACE_CHANGE)
+		xo->params.flags |= XDF_IGNORE_WHITESPACE_CHANGE;
+	if (flags & GIT_DIFF_IGNORE_WHITESPACE_EOL)
+		xo->params.flags |= XDF_IGNORE_WHITESPACE_AT_EOL;
+	if (flags & GIT_DIFF_INDENT_HEURISTIC)
+		xo->params.flags |= XDF_INDENT_HEURISTIC;
+
+	if (flags & GIT_DIFF_PATIENCE)
+		xo->params.flags |= XDF_PATIENCE_DIFF;
+	if (flags & GIT_DIFF_MINIMAL)
+		xo->params.flags |= XDF_NEED_MINIMAL;
+
+	xo->callback.outf = git_xdiff_cb;
+}

vendor/libgit2-sys/libgit2/src/diff_xdiff.h

diff --git a/vendor/libgit2-sys/libgit2/src/diff_xdiff.h b/vendor/libgit2-sys/libgit2/src/diff_xdiff.h
new file mode 100644
index 0000000..aca80b1
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/diff_xdiff.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_diff_xdiff_h__
+#define INCLUDE_diff_xdiff_h__
+
+#include "common.h"
+
+#include "diff.h"
+#include "xdiff/xdiff.h"
+#include "patch_generate.h"
+
+/* xdiff cannot cope with large files.  these files should not be passed to
+ * xdiff.  callers should treat these large files as binary.
+ */
+#define GIT_XDIFF_MAX_SIZE (1024LL * 1024 * 1023)
+
+/* A git_xdiff_output is a git_patch_generate_output with extra fields
+ * necessary to use libxdiff.  Calling git_xdiff_init() will set the diff_cb
+ * field of the output to use xdiff to generate the diffs.
+ */
+typedef struct {
+	git_patch_generated_output output;
+
+	xdemitconf_t config;
+	xpparam_t    params;
+	xdemitcb_t   callback;
+} git_xdiff_output;
+
+void git_xdiff_init(git_xdiff_output *xo, const git_diff_options *opts);
+
+#endif

vendor/libgit2-sys/libgit2/src/errors.c

diff --git a/vendor/libgit2-sys/libgit2/src/errors.c b/vendor/libgit2-sys/libgit2/src/errors.c
new file mode 100644
index 0000000..a874163
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/errors.c
@@ -0,0 +1,213 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "global.h"
+#include "posix.h"
+#include "buffer.h"
+
+/********************************************
+ * New error handling
+ ********************************************/
+
+static git_error g_git_oom_error = {
+	"Out of memory",
+	GITERR_NOMEMORY
+};
+
+static void set_error_from_buffer(int error_class)
+{
+	git_error *error = &GIT_GLOBAL->error_t;
+	git_buf *buf = &GIT_GLOBAL->error_buf;
+
+	error->message = buf->ptr;
+	error->klass = error_class;
+
+	GIT_GLOBAL->last_error = error;
+}
+
+static void set_error(int error_class, char *string)
+{
+	git_buf *buf = &GIT_GLOBAL->error_buf;
+
+	git_buf_clear(buf);
+	if (string) {
+		git_buf_puts(buf, string);
+		git__free(string);
+	}
+
+	set_error_from_buffer(error_class);
+}
+
+void giterr_set_oom(void)
+{
+	GIT_GLOBAL->last_error = &g_git_oom_error;
+}
+
+void giterr_set(int error_class, const char *string, ...)
+{
+	va_list arglist;
+#ifdef GIT_WIN32
+	DWORD win32_error_code = (error_class == GITERR_OS) ? GetLastError() : 0;
+#endif
+	int error_code = (error_class == GITERR_OS) ? errno : 0;
+	git_buf *buf = &GIT_GLOBAL->error_buf;
+
+	git_buf_clear(buf);
+	if (string) {
+		va_start(arglist, string);
+		git_buf_vprintf(buf, string, arglist);
+		va_end(arglist);
+
+		if (error_class == GITERR_OS)
+			git_buf_PUTS(buf, ": ");
+	}
+
+	if (error_class == GITERR_OS) {
+#ifdef GIT_WIN32
+		char * win32_error = git_win32_get_error_message(win32_error_code);
+		if (win32_error) {
+			git_buf_puts(buf, win32_error);
+			git__free(win32_error);
+
+			SetLastError(0);
+		}
+		else
+#endif
+		if (error_code)
+			git_buf_puts(buf, strerror(error_code));
+
+		if (error_code)
+			errno = 0;
+	}
+
+	if (!git_buf_oom(buf))
+		set_error_from_buffer(error_class);
+}
+
+void giterr_set_str(int error_class, const char *string)
+{
+	git_buf *buf = &GIT_GLOBAL->error_buf;
+
+	assert(string);
+
+	if (!string)
+		return;
+
+	git_buf_clear(buf);
+	git_buf_puts(buf, string);
+	if (!git_buf_oom(buf))
+		set_error_from_buffer(error_class);
+}
+
+int giterr_set_regex(const regex_t *regex, int error_code)
+{
+	char error_buf[1024];
+
+	assert(error_code);
+
+	regerror(error_code, regex, error_buf, sizeof(error_buf));
+	giterr_set_str(GITERR_REGEX, error_buf);
+
+	if (error_code == REG_NOMATCH)
+		return GIT_ENOTFOUND;
+
+	return GIT_EINVALIDSPEC;
+}
+
+void giterr_clear(void)
+{
+	if (GIT_GLOBAL->last_error != NULL) {
+		set_error(0, NULL);
+		GIT_GLOBAL->last_error = NULL;
+	}
+
+	errno = 0;
+#ifdef GIT_WIN32
+	SetLastError(0);
+#endif
+}
+
+const git_error *giterr_last(void)
+{
+	return GIT_GLOBAL->last_error;
+}
+
+int giterr_state_capture(git_error_state *state, int error_code)
+{
+	git_error *error = GIT_GLOBAL->last_error;
+	git_buf *error_buf = &GIT_GLOBAL->error_buf;
+
+	memset(state, 0, sizeof(git_error_state));
+
+	if (!error_code)
+		return 0;
+
+	state->error_code = error_code;
+	state->oom = (error == &g_git_oom_error);
+
+	if (error) {
+		state->error_msg.klass = error->klass;
+
+		if (state->oom)
+			state->error_msg.message = g_git_oom_error.message;
+		else
+			state->error_msg.message = git_buf_detach(error_buf);
+	}
+
+	giterr_clear();
+	return error_code;
+}
+
+int giterr_state_restore(git_error_state *state)
+{
+	int ret = 0;
+
+	giterr_clear();
+
+	if (state && state->error_msg.message) {
+		if (state->oom)
+			giterr_set_oom();
+		else
+			set_error(state->error_msg.klass, state->error_msg.message);
+
+		ret = state->error_code;
+		memset(state, 0, sizeof(git_error_state));
+	}
+
+	return ret;
+}
+
+void giterr_state_free(git_error_state *state)
+{
+	if (!state)
+		return;
+
+	if (!state->oom)
+		git__free(state->error_msg.message);
+
+	memset(state, 0, sizeof(git_error_state));
+}
+
+int giterr_system_last(void)
+{
+#ifdef GIT_WIN32
+	return GetLastError();
+#else
+	return errno;
+#endif
+}
+
+void giterr_system_set(int code)
+{
+#ifdef GIT_WIN32
+	SetLastError(code);
+#else
+	errno = code;
+#endif
+}

vendor/libgit2-sys/libgit2/src/features.h.in

diff --git a/vendor/libgit2-sys/libgit2/src/features.h.in b/vendor/libgit2-sys/libgit2/src/features.h.in
new file mode 100644
index 0000000..f414c58
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/features.h.in
@@ -0,0 +1,38 @@
+#ifndef INCLUDE_features_h__
+#define INCLUDE_features_h__
+
+#cmakedefine GIT_DEBUG_POOL 1
+#cmakedefine GIT_TRACE 1
+#cmakedefine GIT_THREADS 1
+#cmakedefine GIT_MSVC_CRTDBG 1
+
+#cmakedefine GIT_ARCH_64 1
+#cmakedefine GIT_ARCH_32 1
+
+#cmakedefine GIT_USE_ICONV 1
+#cmakedefine GIT_USE_NSEC 1
+#cmakedefine GIT_USE_STAT_MTIM 1
+#cmakedefine GIT_USE_STAT_MTIMESPEC 1
+#cmakedefine GIT_USE_STAT_MTIME_NSEC 1
+#cmakedefine GIT_USE_FUTIMENS 1
+#cmakedefine GIT_USE_REGCOMP_L 1
+
+#cmakedefine GIT_SSH 1
+#cmakedefine GIT_SSH_MEMORY_CREDENTIALS 1
+
+#cmakedefine GIT_GSSAPI 1
+#cmakedefine GIT_WINHTTP 1
+#cmakedefine GIT_CURL 1
+
+#cmakedefine GIT_HTTPS 1
+#cmakedefine GIT_OPENSSL 1
+#cmakedefine GIT_SECURE_TRANSPORT 1
+#cmakedefine GIT_MBEDTLS 1
+
+#cmakedefine GIT_SHA1_COLLISIONDETECT 1
+#cmakedefine GIT_SHA1_WIN32 1
+#cmakedefine GIT_SHA1_COMMON_CRYPTO 1
+#cmakedefine GIT_SHA1_OPENSSL 1
+#cmakedefine GIT_SHA1_MBEDTLS 1
+
+#endif

vendor/libgit2-sys/libgit2/src/fetch.c

diff --git a/vendor/libgit2-sys/libgit2/src/fetch.c b/vendor/libgit2-sys/libgit2/src/fetch.c
new file mode 100644
index 0000000..0b22b36
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/fetch.c
@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "fetch.h"
+
+#include "git2/oid.h"
+#include "git2/refs.h"
+#include "git2/revwalk.h"
+#include "git2/transport.h"
+
+#include "remote.h"
+#include "refspec.h"
+#include "pack.h"
+#include "netops.h"
+#include "repository.h"
+#include "refs.h"
+
+static int maybe_want(git_remote *remote, git_remote_head *head, git_odb *odb, git_refspec *tagspec, git_remote_autotag_option_t tagopt)
+{
+	int match = 0;
+
+	if (!git_reference_is_valid_name(head->name))
+		return 0;
+
+	if (tagopt == GIT_REMOTE_DOWNLOAD_TAGS_ALL) {
+		/*
+		 * If tagopt is --tags, always request tags
+		 * in addition to the remote's refspecs
+		 */
+		if (git_refspec_src_matches(tagspec, head->name))
+			match = 1;
+	}
+
+	if (!match && git_remote__matching_refspec(remote, head->name))
+		match = 1;
+
+	if (!match)
+		return 0;
+
+	/* If we have the object, mark it so we don't ask for it */
+	if (git_odb_exists(odb, &head->oid)) {
+		head->local = 1;
+	}
+	else
+		remote->need_pack = 1;
+
+	return git_vector_insert(&remote->refs, head);
+}
+
+static int filter_wants(git_remote *remote, const git_fetch_options *opts)
+{
+	git_remote_head **heads;
+	git_refspec tagspec, head;
+	int error = 0;
+	git_odb *odb;
+	size_t i, heads_len;
+	git_remote_autotag_option_t tagopt = remote->download_tags;
+
+	if (opts && opts->download_tags != GIT_REMOTE_DOWNLOAD_TAGS_UNSPECIFIED)
+		tagopt = opts->download_tags;
+
+	git_vector_clear(&remote->refs);
+	if ((error = git_refspec__parse(&tagspec, GIT_REFSPEC_TAGS, true)) < 0)
+		return error;
+
+	/*
+	 * The fetch refspec can be NULL, and what this means is that the
+	 * user didn't specify one. This is fine, as it means that we're
+	 * not interested in any particular branch but just the remote's
+	 * HEAD, which will be stored in FETCH_HEAD after the fetch.
+	 */
+	if (remote->active_refspecs.length == 0) {
+		if ((error = git_refspec__parse(&head, "HEAD", true)) < 0)
+			goto cleanup;
+
+		error = git_refspec__dwim_one(&remote->active_refspecs, &head, &remote->refs);
+		git_refspec__free(&head);
+
+		if (error < 0)
+			goto cleanup;
+	}
+
+	if (git_repository_odb__weakptr(&odb, remote->repo) < 0)
+		goto cleanup;
+
+	if (git_remote_ls((const git_remote_head ***)&heads, &heads_len, remote) < 0)
+		goto cleanup;
+
+	for (i = 0; i < heads_len; i++) {
+		if ((error = maybe_want(remote, heads[i], odb, &tagspec, tagopt)) < 0)
+			break;
+	}
+
+cleanup:
+	git_refspec__free(&tagspec);
+
+	return error;
+}
+
+/*
+ * In this first version, we push all our refs in and start sending
+ * them out. When we get an ACK we hide that commit and continue
+ * traversing until we're done
+ */
+int git_fetch_negotiate(git_remote *remote, const git_fetch_options *opts)
+{
+	git_transport *t = remote->transport;
+
+	remote->need_pack = 0;
+
+	if (filter_wants(remote, opts) < 0) {
+		giterr_set(GITERR_NET, "failed to filter the reference list for wants");
+		return -1;
+	}
+
+	/* Don't try to negotiate when we don't want anything */
+	if (!remote->need_pack)
+		return 0;
+
+	/*
+	 * Now we have everything set up so we can start tell the
+	 * server what we want and what we have.
+	 */
+	return t->negotiate_fetch(t,
+		remote->repo,
+		(const git_remote_head * const *)remote->refs.contents,
+		remote->refs.length);
+}
+
+int git_fetch_download_pack(git_remote *remote, const git_remote_callbacks *callbacks)
+{
+	git_transport *t = remote->transport;
+	git_transfer_progress_cb progress = NULL;
+	void *payload = NULL;
+
+	if (!remote->need_pack)
+		return 0;
+
+	if (callbacks) {
+		progress = callbacks->transfer_progress;
+		payload  = callbacks->payload;
+	}
+
+	return t->download_pack(t, remote->repo, &remote->stats, progress, payload);
+}
+
+int git_fetch_init_options(git_fetch_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_fetch_options, GIT_FETCH_OPTIONS_INIT);
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/fetch.h

diff --git a/vendor/libgit2-sys/libgit2/src/fetch.h b/vendor/libgit2-sys/libgit2/src/fetch.h
new file mode 100644
index 0000000..1c75af9
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/fetch.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_fetch_h__
+#define INCLUDE_fetch_h__
+
+#include "common.h"
+
+#include "git2/remote.h"
+
+#include "netops.h"
+
+int git_fetch_negotiate(git_remote *remote, const git_fetch_options *opts);
+
+int git_fetch_download_pack(git_remote *remote, const git_remote_callbacks *callbacks);
+
+int git_fetch_setup_walk(git_revwalk **out, git_repository *repo);
+
+#endif

vendor/libgit2-sys/libgit2/src/fetchhead.c

diff --git a/vendor/libgit2-sys/libgit2/src/fetchhead.c b/vendor/libgit2-sys/libgit2/src/fetchhead.c
new file mode 100644
index 0000000..e55e7c8
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/fetchhead.c
@@ -0,0 +1,302 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "fetchhead.h"
+
+#include "git2/types.h"
+#include "git2/oid.h"
+
+#include "buffer.h"
+#include "fileops.h"
+#include "filebuf.h"
+#include "refs.h"
+#include "repository.h"
+
+int git_fetchhead_ref_cmp(const void *a, const void *b)
+{
+	const git_fetchhead_ref *one = (const git_fetchhead_ref *)a;
+	const git_fetchhead_ref *two = (const git_fetchhead_ref *)b;
+
+	if (one->is_merge && !two->is_merge)
+		return -1;
+	if (two->is_merge && !one->is_merge)
+		return 1;
+
+	if (one->ref_name && two->ref_name)
+		return strcmp(one->ref_name, two->ref_name);
+	else if (one->ref_name)
+		return -1;
+	else if (two->ref_name)
+		return 1;
+
+	return 0;
+}
+
+int git_fetchhead_ref_create(
+	git_fetchhead_ref **out,
+	git_oid *oid,
+	unsigned int is_merge,
+	const char *ref_name,
+	const char *remote_url)
+{
+	git_fetchhead_ref *fetchhead_ref;
+
+	assert(out && oid);
+
+	*out = NULL;
+
+	fetchhead_ref = git__malloc(sizeof(git_fetchhead_ref));
+	GITERR_CHECK_ALLOC(fetchhead_ref);
+
+	memset(fetchhead_ref, 0x0, sizeof(git_fetchhead_ref));
+
+	git_oid_cpy(&fetchhead_ref->oid, oid);
+	fetchhead_ref->is_merge = is_merge;
+
+	if (ref_name)
+		fetchhead_ref->ref_name = git__strdup(ref_name);
+
+	if (remote_url)
+		fetchhead_ref->remote_url = git__strdup(remote_url);
+
+	*out = fetchhead_ref;
+
+	return 0;
+}
+
+static int fetchhead_ref_write(
+	git_filebuf *file,
+	git_fetchhead_ref *fetchhead_ref)
+{
+	char oid[GIT_OID_HEXSZ + 1];
+	const char *type, *name;
+	int head = 0;
+
+	assert(file && fetchhead_ref);
+
+	git_oid_fmt(oid, &fetchhead_ref->oid);
+	oid[GIT_OID_HEXSZ] = '\0';
+
+	if (git__prefixcmp(fetchhead_ref->ref_name, GIT_REFS_HEADS_DIR) == 0) {
+		type = "branch ";
+		name = fetchhead_ref->ref_name + strlen(GIT_REFS_HEADS_DIR);
+	} else if(git__prefixcmp(fetchhead_ref->ref_name,
+		GIT_REFS_TAGS_DIR) == 0) {
+		type = "tag ";
+		name = fetchhead_ref->ref_name + strlen(GIT_REFS_TAGS_DIR);
+	} else if (!git__strcmp(fetchhead_ref->ref_name, GIT_HEAD_FILE)) {
+		head = 1;
+	} else {
+		type = "";
+		name = fetchhead_ref->ref_name;
+	}
+
+	if (head)
+		return git_filebuf_printf(file, "%s\t\t%s\n", oid, fetchhead_ref->remote_url);
+
+	return git_filebuf_printf(file, "%s\t%s\t%s'%s' of %s\n",
+		oid,
+		(fetchhead_ref->is_merge) ? "" : "not-for-merge",
+		type,
+		name,
+		fetchhead_ref->remote_url);
+}
+
+int git_fetchhead_write(git_repository *repo, git_vector *fetchhead_refs)
+{
+	git_filebuf file = GIT_FILEBUF_INIT;
+	git_buf path = GIT_BUF_INIT;
+	unsigned int i;
+	git_fetchhead_ref *fetchhead_ref;
+
+	assert(repo && fetchhead_refs);
+
+	if (git_buf_joinpath(&path, repo->gitdir, GIT_FETCH_HEAD_FILE) < 0)
+		return -1;
+
+	if (git_filebuf_open(&file, path.ptr, GIT_FILEBUF_APPEND, GIT_REFS_FILE_MODE) < 0) {
+		git_buf_free(&path);
+		return -1;
+	}
+
+	git_buf_free(&path);
+
+	git_vector_sort(fetchhead_refs);
+
+	git_vector_foreach(fetchhead_refs, i, fetchhead_ref)
+		fetchhead_ref_write(&file, fetchhead_ref);
+
+	return git_filebuf_commit(&file);
+}
+
+static int fetchhead_ref_parse(
+	git_oid *oid,
+	unsigned int *is_merge,
+	git_buf *ref_name,
+	const char **remote_url,
+	char *line,
+	size_t line_num)
+{
+	char *oid_str, *is_merge_str, *desc, *name = NULL;
+	const char *type = NULL;
+	int error = 0;
+
+	*remote_url = NULL;
+
+	if (!*line) {
+		giterr_set(GITERR_FETCHHEAD,
+			"empty line in FETCH_HEAD line %"PRIuZ, line_num);
+		return -1;
+	}
+
+	/* Compat with old git clients that wrote FETCH_HEAD like a loose ref. */
+	if ((oid_str = git__strsep(&line, "\t")) == NULL) {
+		oid_str = line;
+		line += strlen(line);
+
+		*is_merge = 1;
+	}
+
+	if (strlen(oid_str) != GIT_OID_HEXSZ) {
+		giterr_set(GITERR_FETCHHEAD,
+			"invalid object ID in FETCH_HEAD line %"PRIuZ, line_num);
+		return -1;
+	}
+
+	if (git_oid_fromstr(oid, oid_str) < 0) {
+		const git_error *oid_err = giterr_last();
+		const char *err_msg = oid_err ? oid_err->message : "invalid object ID";
+
+		giterr_set(GITERR_FETCHHEAD, "%s in FETCH_HEAD line %"PRIuZ,
+			err_msg, line_num);
+		return -1;
+	}
+
+	/* Parse new data from newer git clients */
+	if (*line) {
+		if ((is_merge_str = git__strsep(&line, "\t")) == NULL) {
+			giterr_set(GITERR_FETCHHEAD,
+				"invalid description data in FETCH_HEAD line %"PRIuZ, line_num);
+			return -1;
+		}
+
+		if (*is_merge_str == '\0')
+			*is_merge = 1;
+		else if (strcmp(is_merge_str, "not-for-merge") == 0)
+			*is_merge = 0;
+		else {
+			giterr_set(GITERR_FETCHHEAD,
+				"invalid for-merge entry in FETCH_HEAD line %"PRIuZ, line_num);
+			return -1;
+		}
+
+		if ((desc = line) == NULL) {
+			giterr_set(GITERR_FETCHHEAD,
+				"invalid description in FETCH_HEAD line %"PRIuZ, line_num);
+			return -1;
+		}
+
+		if (git__prefixcmp(desc, "branch '") == 0) {
+			type = GIT_REFS_HEADS_DIR;
+			name = desc + 8;
+		} else if (git__prefixcmp(desc, "tag '") == 0) {
+			type = GIT_REFS_TAGS_DIR;
+			name = desc + 5;
+		} else if (git__prefixcmp(desc, "'") == 0)
+			name = desc + 1;
+
+		if (name) {
+			if ((desc = strstr(name, "' ")) == NULL ||
+				git__prefixcmp(desc, "' of ") != 0) {
+				giterr_set(GITERR_FETCHHEAD,
+					"invalid description in FETCH_HEAD line %"PRIuZ, line_num);
+				return -1;
+			}
+
+			*desc = '\0';
+			desc += 5;
+		}
+
+		*remote_url = desc;
+	}
+
+	git_buf_clear(ref_name);
+
+	if (type)
+		git_buf_join(ref_name, '/', type, name);
+	else if(name)
+		git_buf_puts(ref_name, name);
+
+	return error;
+}
+
+int git_repository_fetchhead_foreach(git_repository *repo,
+	git_repository_fetchhead_foreach_cb cb,
+	void *payload)
+{
+	git_buf path = GIT_BUF_INIT, file = GIT_BUF_INIT, name = GIT_BUF_INIT;
+	const char *ref_name;
+	git_oid oid;
+	const char *remote_url;
+	unsigned int is_merge = 0;
+	char *buffer, *line;
+	size_t line_num = 0;
+	int error = 0;
+
+	assert(repo && cb);
+
+	if (git_buf_joinpath(&path, repo->gitdir, GIT_FETCH_HEAD_FILE) < 0)
+		return -1;
+
+	if ((error = git_futils_readbuffer(&file, git_buf_cstr(&path))) < 0)
+		goto done;
+
+	buffer = file.ptr;
+
+	while ((line = git__strsep(&buffer, "\n")) != NULL) {
+		++line_num;
+
+		if ((error = fetchhead_ref_parse(
+				&oid, &is_merge, &name, &remote_url, line, line_num)) < 0)
+			goto done;
+
+		if (git_buf_len(&name) > 0)
+			ref_name = git_buf_cstr(&name);
+		else
+			ref_name = NULL;
+
+		error = cb(ref_name, remote_url, &oid, is_merge, payload);
+		if (error) {
+			giterr_set_after_callback(error);
+			goto done;
+		}
+	}
+
+	if (*buffer) {
+		giterr_set(GITERR_FETCHHEAD, "no EOL at line %"PRIuZ, line_num+1);
+		error = -1;
+		goto done;
+	}
+
+done:
+	git_buf_free(&file);
+	git_buf_free(&path);
+	git_buf_free(&name);
+
+	return error;
+}
+
+void git_fetchhead_ref_free(git_fetchhead_ref *fetchhead_ref)
+{
+	if (fetchhead_ref == NULL)
+		return;
+
+	git__free(fetchhead_ref->remote_url);
+	git__free(fetchhead_ref->ref_name);
+	git__free(fetchhead_ref);
+}
+

vendor/libgit2-sys/libgit2/src/fetchhead.h

diff --git a/vendor/libgit2-sys/libgit2/src/fetchhead.h b/vendor/libgit2-sys/libgit2/src/fetchhead.h
new file mode 100644
index 0000000..9e51710
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/fetchhead.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_fetchhead_h__
+#define INCLUDE_fetchhead_h__
+
+#include "common.h"
+
+#include "oid.h"
+#include "vector.h"
+
+typedef struct git_fetchhead_ref {
+	git_oid oid;
+	unsigned int is_merge;
+	char *ref_name;
+	char *remote_url;
+} git_fetchhead_ref;
+
+int git_fetchhead_ref_create(
+	git_fetchhead_ref **fetchhead_ref_out,
+	git_oid *oid,
+	unsigned int is_merge,
+	const char *ref_name,
+	const char *remote_url);
+
+int git_fetchhead_ref_cmp(const void *a, const void *b);
+
+int git_fetchhead_write(git_repository *repo, git_vector *fetchhead_refs);
+
+void git_fetchhead_ref_free(git_fetchhead_ref *fetchhead_ref);
+
+#endif

vendor/libgit2-sys/libgit2/src/filebuf.c

diff --git a/vendor/libgit2-sys/libgit2/src/filebuf.c b/vendor/libgit2-sys/libgit2/src/filebuf.c
new file mode 100644
index 0000000..8b7e489
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/filebuf.c
@@ -0,0 +1,597 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "filebuf.h"
+
+#include "fileops.h"
+
+static const size_t WRITE_BUFFER_SIZE = (4096 * 2);
+
+enum buferr_t {
+	BUFERR_OK = 0,
+	BUFERR_WRITE,
+	BUFERR_ZLIB,
+	BUFERR_MEM
+};
+
+#define ENSURE_BUF_OK(buf) if ((buf)->last_error != BUFERR_OK) { return -1; }
+
+static int verify_last_error(git_filebuf *file)
+{
+	switch (file->last_error) {
+	case BUFERR_WRITE:
+		giterr_set(GITERR_OS, "failed to write out file");
+		return -1;
+
+	case BUFERR_MEM:
+		giterr_set_oom();
+		return -1;
+
+	case BUFERR_ZLIB:
+		giterr_set(GITERR_ZLIB,
+			"Buffer error when writing out ZLib data");
+		return -1;
+
+	default:
+		return 0;
+	}
+}
+
+static int lock_file(git_filebuf *file, int flags, mode_t mode)
+{
+	if (git_path_exists(file->path_lock) == true) {
+		if (flags & GIT_FILEBUF_FORCE)
+			p_unlink(file->path_lock);
+		else {
+			giterr_clear(); /* actual OS error code just confuses */
+			giterr_set(GITERR_OS,
+				"failed to lock file '%s' for writing", file->path_lock);
+			return GIT_ELOCKED;
+		}
+	}
+
+	/* create path to the file buffer is required */
+	if (flags & GIT_FILEBUF_FORCE) {
+		/* XXX: Should dirmode here be configurable? Or is 0777 always fine? */
+		file->fd = git_futils_creat_locked_withpath(file->path_lock, 0777, mode);
+	} else {
+		file->fd = git_futils_creat_locked(file->path_lock, mode);
+	}
+
+	if (file->fd < 0)
+		return file->fd;
+
+	file->fd_is_open = true;
+
+	if ((flags & GIT_FILEBUF_APPEND) && git_path_exists(file->path_original) == true) {
+		git_file source;
+		char buffer[FILEIO_BUFSIZE];
+		ssize_t read_bytes;
+		int error = 0;
+
+		source = p_open(file->path_original, O_RDONLY);
+		if (source < 0) {
+			giterr_set(GITERR_OS,
+				"failed to open file '%s' for reading",
+				file->path_original);
+			return -1;
+		}
+
+		while ((read_bytes = p_read(source, buffer, sizeof(buffer))) > 0) {
+			if ((error = p_write(file->fd, buffer, read_bytes)) < 0)
+				break;
+			if (file->compute_digest)
+				git_hash_update(&file->digest, buffer, read_bytes);
+		}
+
+		p_close(source);
+
+		if (read_bytes < 0) {
+			giterr_set(GITERR_OS, "failed to read file '%s'", file->path_original);
+			return -1;
+		} else if (error < 0) {
+			giterr_set(GITERR_OS, "failed to write file '%s'", file->path_lock);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+void git_filebuf_cleanup(git_filebuf *file)
+{
+	if (file->fd_is_open && file->fd >= 0)
+		p_close(file->fd);
+
+	if (file->created_lock && !file->did_rename && file->path_lock && git_path_exists(file->path_lock))
+		p_unlink(file->path_lock);
+
+	if (file->compute_digest) {
+		git_hash_ctx_cleanup(&file->digest);
+		file->compute_digest = 0;
+	}
+
+	if (file->buffer)
+		git__free(file->buffer);
+
+	/* use the presence of z_buf to decide if we need to deflateEnd */
+	if (file->z_buf) {
+		git__free(file->z_buf);
+		deflateEnd(&file->zs);
+	}
+
+	if (file->path_original)
+		git__free(file->path_original);
+	if (file->path_lock)
+		git__free(file->path_lock);
+
+	memset(file, 0x0, sizeof(git_filebuf));
+	file->fd = -1;
+}
+
+GIT_INLINE(int) flush_buffer(git_filebuf *file)
+{
+	int result = file->write(file, file->buffer, file->buf_pos);
+	file->buf_pos = 0;
+	return result;
+}
+
+int git_filebuf_flush(git_filebuf *file)
+{
+	return flush_buffer(file);
+}
+
+static int write_normal(git_filebuf *file, void *source, size_t len)
+{
+	if (len > 0) {
+		if (p_write(file->fd, (void *)source, len) < 0) {
+			file->last_error = BUFERR_WRITE;
+			return -1;
+		}
+
+		if (file->compute_digest)
+			git_hash_update(&file->digest, source, len);
+	}
+
+	return 0;
+}
+
+static int write_deflate(git_filebuf *file, void *source, size_t len)
+{
+	z_stream *zs = &file->zs;
+
+	if (len > 0 || file->flush_mode == Z_FINISH) {
+		zs->next_in = source;
+		zs->avail_in = (uInt)len;
+
+		do {
+			size_t have;
+
+			zs->next_out = file->z_buf;
+			zs->avail_out = (uInt)file->buf_size;
+
+			if (deflate(zs, file->flush_mode) == Z_STREAM_ERROR) {
+				file->last_error = BUFERR_ZLIB;
+				return -1;
+			}
+
+			have = file->buf_size - (size_t)zs->avail_out;
+
+			if (p_write(file->fd, file->z_buf, have) < 0) {
+				file->last_error = BUFERR_WRITE;
+				return -1;
+			}
+
+		} while (zs->avail_out == 0);
+
+		assert(zs->avail_in == 0);
+
+		if (file->compute_digest)
+			git_hash_update(&file->digest, source, len);
+	}
+
+	return 0;
+}
+
+#define MAX_SYMLINK_DEPTH 5
+
+static int resolve_symlink(git_buf *out, const char *path)
+{
+	int i, error, root;
+	ssize_t ret;
+	struct stat st;
+	git_buf curpath = GIT_BUF_INIT, target = GIT_BUF_INIT;
+
+	if ((error = git_buf_grow(&target, GIT_PATH_MAX + 1)) < 0 ||
+	    (error = git_buf_puts(&curpath, path)) < 0)
+		return error;
+
+	for (i = 0; i < MAX_SYMLINK_DEPTH; i++) {
+		error = p_lstat(curpath.ptr, &st);
+		if (error < 0 && errno == ENOENT) {
+			error = git_buf_puts(out, curpath.ptr);
+			goto cleanup;
+		}
+
+		if (error < 0) {
+			giterr_set(GITERR_OS, "failed to stat '%s'", curpath.ptr);
+			error = -1;
+			goto cleanup;
+		}
+
+		if (!S_ISLNK(st.st_mode)) {
+			error = git_buf_puts(out, curpath.ptr);
+			goto cleanup;
+		}
+
+		ret = p_readlink(curpath.ptr, target.ptr, GIT_PATH_MAX);
+		if (ret < 0) {
+			giterr_set(GITERR_OS, "failed to read symlink '%s'", curpath.ptr);
+			error = -1;
+			goto cleanup;
+		}
+
+		if (ret == GIT_PATH_MAX) {
+			giterr_set(GITERR_INVALID, "symlink target too long");
+			error = -1;
+			goto cleanup;
+		}
+
+		/* readlink(2) won't NUL-terminate for us */
+		target.ptr[ret] = '\0';
+		target.size = ret;
+
+		root = git_path_root(target.ptr);
+		if (root >= 0) {
+			if ((error = git_buf_sets(&curpath, target.ptr)) < 0)
+				goto cleanup;
+		} else {
+			git_buf dir = GIT_BUF_INIT;
+
+			if ((error = git_path_dirname_r(&dir, curpath.ptr)) < 0)
+				goto cleanup;
+
+			git_buf_swap(&curpath, &dir);
+			git_buf_free(&dir);
+
+			if ((error = git_path_apply_relative(&curpath, target.ptr)) < 0)
+				goto cleanup;
+		}
+	}
+
+	giterr_set(GITERR_INVALID, "maximum symlink depth reached");
+	error = -1;
+
+cleanup:
+	git_buf_free(&curpath);
+	git_buf_free(&target);
+	return error;
+}
+
+int git_filebuf_open(git_filebuf *file, const char *path, int flags, mode_t mode)
+{
+	return git_filebuf_open_withsize(file, path, flags, mode, WRITE_BUFFER_SIZE);
+}
+
+int git_filebuf_open_withsize(git_filebuf *file, const char *path, int flags, mode_t mode, size_t size)
+{
+	int compression, error = -1;
+	size_t path_len, alloc_len;
+
+	/* opening an already open buffer is a programming error;
+	 * assert that this never happens instead of returning
+	 * an error code */
+	assert(file && path && file->buffer == NULL);
+
+	memset(file, 0x0, sizeof(git_filebuf));
+
+	if (flags & GIT_FILEBUF_DO_NOT_BUFFER)
+		file->do_not_buffer = true;
+
+	if (flags & GIT_FILEBUF_FSYNC)
+		file->do_fsync = true;
+
+	file->buf_size = size;
+	file->buf_pos = 0;
+	file->fd = -1;
+	file->last_error = BUFERR_OK;
+
+	/* Allocate the main cache buffer */
+	if (!file->do_not_buffer) {
+		file->buffer = git__malloc(file->buf_size);
+		GITERR_CHECK_ALLOC(file->buffer);
+	}
+
+	/* If we are hashing on-write, allocate a new hash context */
+	if (flags & GIT_FILEBUF_HASH_CONTENTS) {
+		file->compute_digest = 1;
+
+		if (git_hash_ctx_init(&file->digest) < 0)
+			goto cleanup;
+	}
+
+	compression = flags >> GIT_FILEBUF_DEFLATE_SHIFT;
+
+	/* If we are deflating on-write, */
+	if (compression != 0) {
+		/* Initialize the ZLib stream */
+		if (deflateInit(&file->zs, compression) != Z_OK) {
+			giterr_set(GITERR_ZLIB, "failed to initialize zlib");
+			goto cleanup;
+		}
+
+		/* Allocate the Zlib cache buffer */
+		file->z_buf = git__malloc(file->buf_size);
+		GITERR_CHECK_ALLOC(file->z_buf);
+
+		/* Never flush */
+		file->flush_mode = Z_NO_FLUSH;
+		file->write = &write_deflate;
+	} else {
+		file->write = &write_normal;
+	}
+
+	/* If we are writing to a temp file */
+	if (flags & GIT_FILEBUF_TEMPORARY) {
+		git_buf tmp_path = GIT_BUF_INIT;
+
+		/* Open the file as temporary for locking */
+		file->fd = git_futils_mktmp(&tmp_path, path, mode);
+
+		if (file->fd < 0) {
+			git_buf_free(&tmp_path);
+			goto cleanup;
+		}
+		file->fd_is_open = true;
+		file->created_lock = true;
+
+		/* No original path */
+		file->path_original = NULL;
+		file->path_lock = git_buf_detach(&tmp_path);
+		GITERR_CHECK_ALLOC(file->path_lock);
+	} else {
+		git_buf resolved_path = GIT_BUF_INIT;
+
+		if ((error = resolve_symlink(&resolved_path, path)) < 0)
+			goto cleanup;
+
+		/* Save the original path of the file */
+		path_len = resolved_path.size;
+		file->path_original = git_buf_detach(&resolved_path);
+
+		/* create the locking path by appending ".lock" to the original */
+		GITERR_CHECK_ALLOC_ADD(&alloc_len, path_len, GIT_FILELOCK_EXTLENGTH);
+		file->path_lock = git__malloc(alloc_len);
+		GITERR_CHECK_ALLOC(file->path_lock);
+
+		memcpy(file->path_lock, file->path_original, path_len);
+		memcpy(file->path_lock + path_len, GIT_FILELOCK_EXTENSION, GIT_FILELOCK_EXTLENGTH);
+
+		if (git_path_isdir(file->path_original)) {
+			giterr_set(GITERR_FILESYSTEM, "path '%s' is a directory", file->path_original);
+			error = GIT_EDIRECTORY;
+			goto cleanup;
+		}
+
+		/* open the file for locking */
+		if ((error = lock_file(file, flags, mode)) < 0)
+			goto cleanup;
+
+		file->created_lock = true;
+	}
+
+	return 0;
+
+cleanup:
+	git_filebuf_cleanup(file);
+	return error;
+}
+
+int git_filebuf_hash(git_oid *oid, git_filebuf *file)
+{
+	assert(oid && file && file->compute_digest);
+
+	flush_buffer(file);
+
+	if (verify_last_error(file) < 0)
+		return -1;
+
+	git_hash_final(oid, &file->digest);
+	git_hash_ctx_cleanup(&file->digest);
+	file->compute_digest = 0;
+
+	return 0;
+}
+
+int git_filebuf_commit_at(git_filebuf *file, const char *path)
+{
+	git__free(file->path_original);
+	file->path_original = git__strdup(path);
+	GITERR_CHECK_ALLOC(file->path_original);
+
+	return git_filebuf_commit(file);
+}
+
+int git_filebuf_commit(git_filebuf *file)
+{
+	/* temporary files cannot be committed */
+	assert(file && file->path_original);
+
+	file->flush_mode = Z_FINISH;
+	flush_buffer(file);
+
+	if (verify_last_error(file) < 0)
+		goto on_error;
+
+	file->fd_is_open = false;
+
+	if (file->do_fsync && p_fsync(file->fd) < 0) {
+		giterr_set(GITERR_OS, "failed to fsync '%s'", file->path_lock);
+		goto on_error;
+	}
+
+	if (p_close(file->fd) < 0) {
+		giterr_set(GITERR_OS, "failed to close file at '%s'", file->path_lock);
+		goto on_error;
+	}
+
+	file->fd = -1;
+
+	if (p_rename(file->path_lock, file->path_original) < 0) {
+		giterr_set(GITERR_OS, "failed to rename lockfile to '%s'", file->path_original);
+		goto on_error;
+	}
+
+	if (file->do_fsync && git_futils_fsync_parent(file->path_original) < 0)
+		goto on_error;
+
+	file->did_rename = true;
+
+	git_filebuf_cleanup(file);
+	return 0;
+
+on_error:
+	git_filebuf_cleanup(file);
+	return -1;
+}
+
+GIT_INLINE(void) add_to_cache(git_filebuf *file, const void *buf, size_t len)
+{
+	memcpy(file->buffer + file->buf_pos, buf, len);
+	file->buf_pos += len;
+}
+
+int git_filebuf_write(git_filebuf *file, const void *buff, size_t len)
+{
+	const unsigned char *buf = buff;
+
+	ENSURE_BUF_OK(file);
+
+	if (file->do_not_buffer)
+		return file->write(file, (void *)buff, len);
+
+	for (;;) {
+		size_t space_left = file->buf_size - file->buf_pos;
+
+		/* cache if it's small */
+		if (space_left > len) {
+			add_to_cache(file, buf, len);
+			return 0;
+		}
+
+		add_to_cache(file, buf, space_left);
+		if (flush_buffer(file) < 0)
+			return -1;
+
+		len -= space_left;
+		buf += space_left;
+	}
+}
+
+int git_filebuf_reserve(git_filebuf *file, void **buffer, size_t len)
+{
+	size_t space_left = file->buf_size - file->buf_pos;
+
+	*buffer = NULL;
+
+	ENSURE_BUF_OK(file);
+
+	if (len > file->buf_size) {
+		file->last_error = BUFERR_MEM;
+		return -1;
+	}
+
+	if (space_left <= len) {
+		if (flush_buffer(file) < 0)
+			return -1;
+	}
+
+	*buffer = (file->buffer + file->buf_pos);
+	file->buf_pos += len;
+
+	return 0;
+}
+
+int git_filebuf_printf(git_filebuf *file, const char *format, ...)
+{
+	va_list arglist;
+	size_t space_left, len, alloclen;
+	int written, res;
+	char *tmp_buffer;
+
+	ENSURE_BUF_OK(file);
+
+	space_left = file->buf_size - file->buf_pos;
+
+	do {
+		va_start(arglist, format);
+		written = p_vsnprintf((char *)file->buffer + file->buf_pos, space_left, format, arglist);
+		va_end(arglist);
+
+		if (written < 0) {
+			file->last_error = BUFERR_MEM;
+			return -1;
+		}
+
+		len = written;
+		if (len + 1 <= space_left) {
+			file->buf_pos += len;
+			return 0;
+		}
+
+		if (flush_buffer(file) < 0)
+			return -1;
+
+		space_left = file->buf_size - file->buf_pos;
+
+	} while (len + 1 <= space_left);
+
+	if (GIT_ADD_SIZET_OVERFLOW(&alloclen, len, 1) ||
+		!(tmp_buffer = git__malloc(alloclen))) {
+		file->last_error = BUFERR_MEM;
+		return -1;
+	}
+
+	va_start(arglist, format);
+	written = p_vsnprintf(tmp_buffer, len + 1, format, arglist);
+	va_end(arglist);
+
+	if (written < 0) {
+		git__free(tmp_buffer);
+		file->last_error = BUFERR_MEM;
+		return -1;
+	}
+
+	res = git_filebuf_write(file, tmp_buffer, len);
+	git__free(tmp_buffer);
+
+	return res;
+}
+
+int git_filebuf_stats(time_t *mtime, size_t *size, git_filebuf *file)
+{
+	int res;
+	struct stat st;
+
+	if (file->fd_is_open)
+		res = p_fstat(file->fd, &st);
+	else
+		res = p_stat(file->path_original, &st);
+
+	if (res < 0) {
+		giterr_set(GITERR_OS, "could not get stat info for '%s'",
+			file->path_original);
+		return res;
+	}
+
+	if (mtime)
+		*mtime = st.st_mtime;
+	if (size)
+		*size = (size_t)st.st_size;
+
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/filebuf.h

diff --git a/vendor/libgit2-sys/libgit2/src/filebuf.h b/vendor/libgit2-sys/libgit2/src/filebuf.h
new file mode 100644
index 0000000..f51ff23
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/filebuf.h
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_filebuf_h__
+#define INCLUDE_filebuf_h__
+
+#include "common.h"
+
+#include "fileops.h"
+#include "hash.h"
+#include <zlib.h>
+
+#ifdef GIT_THREADS
+#	define GIT_FILEBUF_THREADS
+#endif
+
+#define GIT_FILEBUF_HASH_CONTENTS		(1 << 0)
+#define GIT_FILEBUF_APPEND				(1 << 2)
+#define GIT_FILEBUF_FORCE				(1 << 3)
+#define GIT_FILEBUF_TEMPORARY			(1 << 4)
+#define GIT_FILEBUF_DO_NOT_BUFFER		(1 << 5)
+#define GIT_FILEBUF_FSYNC				(1 << 6)
+#define GIT_FILEBUF_DEFLATE_SHIFT		(7)
+
+#define GIT_FILELOCK_EXTENSION ".lock\0"
+#define GIT_FILELOCK_EXTLENGTH 6
+
+typedef struct git_filebuf git_filebuf;
+struct git_filebuf {
+	char *path_original;
+	char *path_lock;
+
+	int (*write)(git_filebuf *file, void *source, size_t len);
+
+	bool compute_digest;
+	git_hash_ctx digest;
+
+	unsigned char *buffer;
+	unsigned char *z_buf;
+
+	z_stream zs;
+	int flush_mode;
+
+	size_t buf_size, buf_pos;
+	git_file fd;
+	bool fd_is_open;
+	bool created_lock;
+	bool did_rename;
+	bool do_not_buffer;
+	bool do_fsync;
+	int last_error;
+};
+
+#define GIT_FILEBUF_INIT {0}
+
+/*
+ * The git_filebuf object lifecycle is:
+ * - Allocate git_filebuf, preferably using GIT_FILEBUF_INIT.
+ *
+ * - Call git_filebuf_open() to initialize the filebuf for use.
+ *
+ * - Make as many calls to git_filebuf_write(), git_filebuf_printf(),
+ *   git_filebuf_reserve() as you like. The error codes for these
+ *   functions don't need to be checked. They are stored internally
+ *   by the file buffer.
+ *
+ * - While you are writing, you may call git_filebuf_hash() to get
+ *   the hash of all you have written so far. This function will
+ *   fail if any of the previous writes to the buffer failed.
+ *
+ * - To close the git_filebuf, you may call git_filebuf_commit() or
+ *   git_filebuf_commit_at() to save the file, or
+ *   git_filebuf_cleanup() to abandon the file.  All of these will
+ *   free the git_filebuf object. Likewise, all of these will fail
+ *   if any of the previous writes to the buffer failed, and set
+ *   an error code accordingly.
+ */
+int git_filebuf_write(git_filebuf *lock, const void *buff, size_t len);
+int git_filebuf_reserve(git_filebuf *file, void **buff, size_t len);
+int git_filebuf_printf(git_filebuf *file, const char *format, ...) GIT_FORMAT_PRINTF(2, 3);
+
+int git_filebuf_open(git_filebuf *lock, const char *path, int flags, mode_t mode);
+int git_filebuf_open_withsize(git_filebuf *file, const char *path, int flags, mode_t mode, size_t size);
+int git_filebuf_commit(git_filebuf *lock);
+int git_filebuf_commit_at(git_filebuf *lock, const char *path);
+void git_filebuf_cleanup(git_filebuf *lock);
+int git_filebuf_hash(git_oid *oid, git_filebuf *file);
+int git_filebuf_flush(git_filebuf *file);
+int git_filebuf_stats(time_t *mtime, size_t *size, git_filebuf *file);
+
+#endif

vendor/libgit2-sys/libgit2/src/fileops.c

diff --git a/vendor/libgit2-sys/libgit2/src/fileops.c b/vendor/libgit2-sys/libgit2/src/fileops.c
new file mode 100644
index 0000000..58988c2
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/fileops.c
@@ -0,0 +1,1181 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "fileops.h"
+
+#include "global.h"
+#include "strmap.h"
+#include <ctype.h>
+#if GIT_WIN32
+#include "win32/findfile.h"
+#endif
+
+int git_futils_mkpath2file(const char *file_path, const mode_t mode)
+{
+	return git_futils_mkdir(
+		file_path, mode,
+		GIT_MKDIR_PATH | GIT_MKDIR_SKIP_LAST | GIT_MKDIR_VERIFY_DIR);
+}
+
+int git_futils_mktmp(git_buf *path_out, const char *filename, mode_t mode)
+{
+	int fd;
+	mode_t mask;
+
+	p_umask(mask = p_umask(0));
+
+	git_buf_sets(path_out, filename);
+	git_buf_puts(path_out, "_git2_XXXXXX");
+
+	if (git_buf_oom(path_out))
+		return -1;
+
+	if ((fd = p_mkstemp(path_out->ptr)) < 0) {
+		giterr_set(GITERR_OS,
+			"failed to create temporary file '%s'", path_out->ptr);
+		return -1;
+	}
+
+	if (p_chmod(path_out->ptr, (mode & ~mask))) {
+		giterr_set(GITERR_OS,
+			"failed to set permissions on file '%s'", path_out->ptr);
+		return -1;
+	}
+
+	return fd;
+}
+
+int git_futils_creat_withpath(const char *path, const mode_t dirmode, const mode_t mode)
+{
+	int fd;
+
+	if (git_futils_mkpath2file(path, dirmode) < 0)
+		return -1;
+
+	fd = p_creat(path, mode);
+	if (fd < 0) {
+		giterr_set(GITERR_OS, "failed to create file '%s'", path);
+		return -1;
+	}
+
+	return fd;
+}
+
+int git_futils_creat_locked(const char *path, const mode_t mode)
+{
+	int fd = p_open(path, O_WRONLY | O_CREAT | O_EXCL | O_BINARY | O_CLOEXEC,
+		mode);
+
+	if (fd < 0) {
+		int error = errno;
+		giterr_set(GITERR_OS, "failed to create locked file '%s'", path);
+		switch (error) {
+		case EEXIST:
+			return GIT_ELOCKED;
+		case ENOENT:
+			return GIT_ENOTFOUND;
+		default:
+			return -1;
+		}
+	}
+
+	return fd;
+}
+
+int git_futils_creat_locked_withpath(const char *path, const mode_t dirmode, const mode_t mode)
+{
+	if (git_futils_mkpath2file(path, dirmode) < 0)
+		return -1;
+
+	return git_futils_creat_locked(path, mode);
+}
+
+int git_futils_open_ro(const char *path)
+{
+	int fd = p_open(path, O_RDONLY);
+	if (fd < 0)
+		return git_path_set_error(errno, path, "open");
+	return fd;
+}
+
+int git_futils_truncate(const char *path, int mode)
+{
+	int fd = p_open(path, O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC, mode);
+	if (fd < 0)
+		return git_path_set_error(errno, path, "open");
+
+	close(fd);
+	return 0;
+}
+
+git_off_t git_futils_filesize(git_file fd)
+{
+	struct stat sb;
+
+	if (p_fstat(fd, &sb)) {
+		giterr_set(GITERR_OS, "failed to stat file descriptor");
+		return -1;
+	}
+
+	return sb.st_size;
+}
+
+mode_t git_futils_canonical_mode(mode_t raw_mode)
+{
+	if (S_ISREG(raw_mode))
+		return S_IFREG | GIT_PERMS_CANONICAL(raw_mode);
+	else if (S_ISLNK(raw_mode))
+		return S_IFLNK;
+	else if (S_ISGITLINK(raw_mode))
+		return S_IFGITLINK;
+	else if (S_ISDIR(raw_mode))
+		return S_IFDIR;
+	else
+		return 0;
+}
+
+int git_futils_readbuffer_fd(git_buf *buf, git_file fd, size_t len)
+{
+	ssize_t read_size = 0;
+	size_t alloc_len;
+
+	git_buf_clear(buf);
+
+	if (!git__is_ssizet(len)) {
+		giterr_set(GITERR_INVALID, "read too large");
+		return -1;
+	}
+
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, len, 1);
+	if (git_buf_grow(buf, alloc_len) < 0)
+		return -1;
+
+	/* p_read loops internally to read len bytes */
+	read_size = p_read(fd, buf->ptr, len);
+
+	if (read_size != (ssize_t)len) {
+		giterr_set(GITERR_OS, "failed to read descriptor");
+		git_buf_free(buf);
+		return -1;
+	}
+
+	buf->ptr[read_size] = '\0';
+	buf->size = read_size;
+
+	return 0;
+}
+
+int git_futils_readbuffer_updated(
+	git_buf *out, const char *path, git_oid *checksum, int *updated)
+{
+	int error;
+	git_file fd;
+	struct stat st;
+	git_buf buf = GIT_BUF_INIT;
+	git_oid checksum_new;
+
+	assert(out && path && *path);
+
+	if (updated != NULL)
+		*updated = 0;
+
+	if (p_stat(path, &st) < 0)
+		return git_path_set_error(errno, path, "stat");
+
+
+	if (S_ISDIR(st.st_mode)) {
+		giterr_set(GITERR_INVALID, "requested file is a directory");
+		return GIT_ENOTFOUND;
+	}
+
+	if (!git__is_sizet(st.st_size+1)) {
+		giterr_set(GITERR_OS, "invalid regular file stat for '%s'", path);
+		return -1;
+	}
+
+	if ((fd = git_futils_open_ro(path)) < 0)
+		return fd;
+
+	if (git_futils_readbuffer_fd(&buf, fd, (size_t)st.st_size) < 0) {
+		p_close(fd);
+		return -1;
+	}
+
+	p_close(fd);
+
+	if (checksum) {
+		if ((error = git_hash_buf(&checksum_new, buf.ptr, buf.size)) < 0) {
+			git_buf_free(&buf);
+			return error;
+		}
+
+		/*
+		 * If we were given a checksum, we only want to use it if it's different
+		 */
+		if (!git_oid__cmp(checksum, &checksum_new)) {
+			git_buf_free(&buf);
+			if (updated)
+				*updated = 0;
+
+			return 0;
+		}
+
+		git_oid_cpy(checksum, &checksum_new);
+	}
+
+	/*
+	 * If we're here, the file did change, or the user didn't have an old version
+	 */
+	if (updated != NULL)
+		*updated = 1;
+
+	git_buf_swap(out, &buf);
+	git_buf_free(&buf);
+
+	return 0;
+}
+
+int git_futils_readbuffer(git_buf *buf, const char *path)
+{
+	return git_futils_readbuffer_updated(buf, path, NULL, NULL);
+}
+
+int git_futils_writebuffer(
+	const git_buf *buf,	const char *path, int flags, mode_t mode)
+{
+	int fd, do_fsync = 0, error = 0;
+
+	if (!flags)
+		flags = O_CREAT | O_TRUNC | O_WRONLY;
+
+	if ((flags & O_FSYNC) != 0)
+		do_fsync = 1;
+
+	flags &= ~O_FSYNC;
+
+	if (!mode)
+		mode = GIT_FILEMODE_BLOB;
+
+	if ((fd = p_open(path, flags, mode)) < 0) {
+		giterr_set(GITERR_OS, "could not open '%s' for writing", path);
+		return fd;
+	}
+
+	if ((error = p_write(fd, git_buf_cstr(buf), git_buf_len(buf))) < 0) {
+		giterr_set(GITERR_OS, "could not write to '%s'", path);
+		(void)p_close(fd);
+		return error;
+	}
+
+	if (do_fsync && (error = p_fsync(fd)) < 0) {
+		giterr_set(GITERR_OS, "could not fsync '%s'", path);
+		p_close(fd);
+		return error;
+	}
+
+	if ((error = p_close(fd)) < 0) {
+		giterr_set(GITERR_OS, "error while closing '%s'", path);
+		return error;
+	}
+
+	if (do_fsync && (flags & O_CREAT))
+		error = git_futils_fsync_parent(path);
+
+	return error;
+}
+
+int git_futils_mv_withpath(const char *from, const char *to, const mode_t dirmode)
+{
+	if (git_futils_mkpath2file(to, dirmode) < 0)
+		return -1;
+
+	if (p_rename(from, to) < 0) {
+		giterr_set(GITERR_OS, "failed to rename '%s' to '%s'", from, to);
+		return -1;
+	}
+
+	return 0;
+}
+
+int git_futils_mmap_ro(git_map *out, git_file fd, git_off_t begin, size_t len)
+{
+	return p_mmap(out, len, GIT_PROT_READ, GIT_MAP_SHARED, fd, begin);
+}
+
+int git_futils_mmap_ro_file(git_map *out, const char *path)
+{
+	git_file fd = git_futils_open_ro(path);
+	git_off_t len;
+	int result;
+
+	if (fd < 0)
+		return fd;
+
+	if ((len = git_futils_filesize(fd)) < 0) {
+		result = -1;
+		goto out;
+	}
+
+	if (!git__is_sizet(len)) {
+		giterr_set(GITERR_OS, "file `%s` too large to mmap", path);
+		result = -1;
+		goto out;
+	}
+
+	result = git_futils_mmap_ro(out, fd, 0, (size_t)len);
+out:
+	p_close(fd);
+	return result;
+}
+
+void git_futils_mmap_free(git_map *out)
+{
+	p_munmap(out);
+}
+
+GIT_INLINE(int) mkdir_validate_dir(
+	const char *path,
+	struct stat *st,
+	mode_t mode,
+	uint32_t flags,
+	struct git_futils_mkdir_options *opts)
+{
+	/* with exclusive create, existing dir is an error */
+	if ((flags & GIT_MKDIR_EXCL) != 0) {
+		giterr_set(GITERR_FILESYSTEM,
+			"failed to make directory '%s': directory exists", path);
+		return GIT_EEXISTS;
+	}
+
+	if ((S_ISREG(st->st_mode) && (flags & GIT_MKDIR_REMOVE_FILES)) ||
+		(S_ISLNK(st->st_mode) && (flags & GIT_MKDIR_REMOVE_SYMLINKS))) {
+		if (p_unlink(path) < 0) {
+			giterr_set(GITERR_OS, "failed to remove %s '%s'",
+				S_ISLNK(st->st_mode) ? "symlink" : "file", path);
+			return GIT_EEXISTS;
+		}
+
+		opts->perfdata.mkdir_calls++;
+
+		if (p_mkdir(path, mode) < 0) {
+			giterr_set(GITERR_OS, "failed to make directory '%s'", path);
+			return GIT_EEXISTS;
+		}
+	}
+
+	else if (S_ISLNK(st->st_mode)) {
+		/* Re-stat the target, make sure it's a directory */
+		opts->perfdata.stat_calls++;
+
+		if (p_stat(path, st) < 0) {
+			giterr_set(GITERR_OS, "failed to make directory '%s'", path);
+			return GIT_EEXISTS;
+		}
+	}
+
+	else if (!S_ISDIR(st->st_mode)) {
+		giterr_set(GITERR_FILESYSTEM,
+			"failed to make directory '%s': directory exists", path);
+		return GIT_EEXISTS;
+	}
+
+	return 0;
+}
+
+GIT_INLINE(int) mkdir_validate_mode(
+	const char *path,
+	struct stat *st,
+	bool terminal_path,
+	mode_t mode,
+	uint32_t flags,
+	struct git_futils_mkdir_options *opts)
+{
+	if (((terminal_path && (flags & GIT_MKDIR_CHMOD) != 0) ||
+		(flags & GIT_MKDIR_CHMOD_PATH) != 0) && st->st_mode != mode) {
+
+		opts->perfdata.chmod_calls++;
+
+		if (p_chmod(path, mode) < 0) {
+			giterr_set(GITERR_OS, "failed to set permissions on '%s'", path);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+GIT_INLINE(int) mkdir_canonicalize(
+	git_buf *path,
+	uint32_t flags)
+{
+	ssize_t root_len;
+
+	if (path->size == 0) {
+		giterr_set(GITERR_OS, "attempt to create empty path");
+		return -1;
+	}
+
+	/* Trim trailing slashes (except the root) */
+	if ((root_len = git_path_root(path->ptr)) < 0)
+		root_len = 0;
+	else
+		root_len++;
+
+	while (path->size > (size_t)root_len && path->ptr[path->size - 1] == '/')
+		path->ptr[--path->size] = '\0';
+
+	/* if we are not supposed to made the last element, truncate it */
+	if ((flags & GIT_MKDIR_SKIP_LAST2) != 0) {
+		git_path_dirname_r(path, path->ptr);
+		flags |= GIT_MKDIR_SKIP_LAST;
+	}
+	if ((flags & GIT_MKDIR_SKIP_LAST) != 0) {
+		git_path_dirname_r(path, path->ptr);
+	}
+
+	/* We were either given the root path (or trimmed it to
+	* the root), we don't have anything to do.
+	*/
+	if (path->size <= (size_t)root_len)
+		git_buf_clear(path);
+
+	return 0;
+}
+
+int git_futils_mkdir(
+	const char *path,
+	mode_t mode,
+	uint32_t flags)
+{
+	git_buf make_path = GIT_BUF_INIT, parent_path = GIT_BUF_INIT;
+	const char *relative;
+	struct git_futils_mkdir_options opts = { 0 };
+	struct stat st;
+	size_t depth = 0;
+	int len = 0, root_len, error;
+
+	if ((error = git_buf_puts(&make_path, path)) < 0 ||
+		(error = mkdir_canonicalize(&make_path, flags)) < 0 ||
+		(error = git_buf_puts(&parent_path, make_path.ptr)) < 0 ||
+		make_path.size == 0)
+		goto done;
+
+	root_len = git_path_root(make_path.ptr);
+
+	/* find the first parent directory that exists.  this will be used
+	 * as the base to dirname_relative.
+	 */
+	for (relative = make_path.ptr; parent_path.size; ) {
+		error = p_lstat(parent_path.ptr, &st);
+
+		if (error == 0) {
+			break;
+		} else if (errno != ENOENT) {
+			giterr_set(GITERR_OS, "failed to stat '%s'", parent_path.ptr);
+			goto done;
+		}
+
+		depth++;
+
+		/* examine the parent of the current path */
+		if ((len = git_path_dirname_r(&parent_path, parent_path.ptr)) < 0) {
+			error = len;
+			goto done;
+		}
+
+		assert(len);
+
+		/* we've walked all the given path's parents and it's either relative
+		 * or rooted.  either way, give up and make the entire path.
+		 */
+		if ((len == 1 && parent_path.ptr[0] == '.') || len == root_len+1) {
+			relative = make_path.ptr;
+			break;
+		}
+
+		relative = make_path.ptr + len + 1;
+
+		/* not recursive? just make this directory relative to its parent. */
+		if ((flags & GIT_MKDIR_PATH) == 0)
+			break;
+	}
+
+	/* we found an item at the location we're trying to create,
+	 * validate it.
+	 */
+	if (depth == 0) {
+		error = mkdir_validate_dir(make_path.ptr, &st, mode, flags, &opts);
+
+		if (!error)
+			error = mkdir_validate_mode(
+				make_path.ptr, &st, true, mode, flags, &opts);
+
+		goto done;
+	}
+
+	/* we already took `SKIP_LAST` and `SKIP_LAST2` into account when
+	 * canonicalizing `make_path`.
+	 */
+	flags &= ~(GIT_MKDIR_SKIP_LAST2 | GIT_MKDIR_SKIP_LAST);
+
+	error = git_futils_mkdir_relative(relative,
+		parent_path.size ? parent_path.ptr : NULL, mode, flags, &opts);
+
+done:
+	git_buf_free(&make_path);
+	git_buf_free(&parent_path);
+	return error;
+}
+
+int git_futils_mkdir_r(const char *path, const mode_t mode)
+{
+	return git_futils_mkdir(path, mode, GIT_MKDIR_PATH);
+}
+
+int git_futils_mkdir_relative(
+	const char *relative_path,
+	const char *base,
+	mode_t mode,
+	uint32_t flags,
+	struct git_futils_mkdir_options *opts)
+{
+	git_buf make_path = GIT_BUF_INIT;
+	ssize_t root = 0, min_root_len;
+	char lastch = '/', *tail;
+	struct stat st;
+	struct git_futils_mkdir_options empty_opts = {0};
+	int error;
+
+	if (!opts)
+		opts = &empty_opts;
+
+	/* build path and find "root" where we should start calling mkdir */
+	if (git_path_join_unrooted(&make_path, relative_path, base, &root) < 0)
+		return -1;
+
+	if ((error = mkdir_canonicalize(&make_path, flags)) < 0 ||
+		make_path.size == 0)
+		goto done;
+
+	/* if we are not supposed to make the whole path, reset root */
+	if ((flags & GIT_MKDIR_PATH) == 0)
+		root = git_buf_rfind(&make_path, '/');
+
+	/* advance root past drive name or network mount prefix */
+	min_root_len = git_path_root(make_path.ptr);
+	if (root < min_root_len)
+		root = min_root_len;
+	while (root >= 0 && make_path.ptr[root] == '/')
+		++root;
+
+	/* clip root to make_path length */
+	if (root > (ssize_t)make_path.size)
+		root = (ssize_t)make_path.size; /* i.e. NUL byte of string */
+	if (root < 0)
+		root = 0;
+
+	/* walk down tail of path making each directory */
+	for (tail = &make_path.ptr[root]; *tail; *tail = lastch) {
+		bool mkdir_attempted = false;
+
+		/* advance tail to include next path component */
+		while (*tail == '/')
+			tail++;
+		while (*tail && *tail != '/')
+			tail++;
+
+		/* truncate path at next component */
+		lastch = *tail;
+		*tail = '\0';
+		st.st_mode = 0;
+
+		if (opts->dir_map && git_strmap_exists(opts->dir_map, make_path.ptr))
+			continue;
+
+		/* See what's going on with this path component */
+		opts->perfdata.stat_calls++;
+
+retry_lstat:
+		if (p_lstat(make_path.ptr, &st) < 0) {
+			if (mkdir_attempted || errno != ENOENT) {
+				giterr_set(GITERR_OS, "cannot access component in path '%s'", make_path.ptr);
+				error = -1;
+				goto done;
+			}
+
+			giterr_clear();
+			opts->perfdata.mkdir_calls++;
+			mkdir_attempted = true;
+			if (p_mkdir(make_path.ptr, mode) < 0) {
+				if (errno == EEXIST)
+					goto retry_lstat;
+				giterr_set(GITERR_OS, "failed to make directory '%s'", make_path.ptr);
+				error = -1;
+				goto done;
+			}
+		} else {
+			if ((error = mkdir_validate_dir(
+				make_path.ptr, &st, mode, flags, opts)) < 0)
+				goto done;
+		}
+
+		/* chmod if requested and necessary */
+		if ((error = mkdir_validate_mode(
+			make_path.ptr, &st, (lastch == '\0'), mode, flags, opts)) < 0)
+			goto done;
+
+		if (opts->dir_map && opts->pool) {
+			char *cache_path;
+			size_t alloc_size;
+
+			GITERR_CHECK_ALLOC_ADD(&alloc_size, make_path.size, 1);
+			if (!git__is_uint32(alloc_size))
+				return -1;
+			cache_path = git_pool_malloc(opts->pool, (uint32_t)alloc_size);
+			GITERR_CHECK_ALLOC(cache_path);
+
+			memcpy(cache_path, make_path.ptr, make_path.size + 1);
+
+			git_strmap_insert(opts->dir_map, cache_path, cache_path, &error);
+			if (error < 0)
+				goto done;
+		}
+	}
+
+	error = 0;
+
+	/* check that full path really is a directory if requested & needed */
+	if ((flags & GIT_MKDIR_VERIFY_DIR) != 0 &&
+		lastch != '\0') {
+		opts->perfdata.stat_calls++;
+
+		if (p_stat(make_path.ptr, &st) < 0 || !S_ISDIR(st.st_mode)) {
+			giterr_set(GITERR_OS, "path is not a directory '%s'",
+				make_path.ptr);
+			error = GIT_ENOTFOUND;
+		}
+	}
+
+done:
+	git_buf_free(&make_path);
+	return error;
+}
+
+typedef struct {
+	const char *base;
+	size_t baselen;
+	uint32_t flags;
+	int depth;
+} futils__rmdir_data;
+
+#define FUTILS_MAX_DEPTH 100
+
+static int futils__error_cannot_rmdir(const char *path, const char *filemsg)
+{
+	if (filemsg)
+		giterr_set(GITERR_OS, "could not remove directory '%s': %s",
+				   path, filemsg);
+	else
+		giterr_set(GITERR_OS, "could not remove directory '%s'", path);
+
+	return -1;
+}
+
+static int futils__rm_first_parent(git_buf *path, const char *ceiling)
+{
+	int error = GIT_ENOTFOUND;
+	struct stat st;
+
+	while (error == GIT_ENOTFOUND) {
+		git_buf_rtruncate_at_char(path, '/');
+
+		if (!path->size || git__prefixcmp(path->ptr, ceiling) != 0)
+			error = 0;
+		else if (p_lstat_posixly(path->ptr, &st) == 0) {
+			if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode))
+				error = p_unlink(path->ptr);
+			else if (!S_ISDIR(st.st_mode))
+				error = -1; /* fail to remove non-regular file */
+		} else if (errno != ENOTDIR)
+			error = -1;
+	}
+
+	if (error)
+		futils__error_cannot_rmdir(path->ptr, "cannot remove parent");
+
+	return error;
+}
+
+static int futils__rmdir_recurs_foreach(void *opaque, git_buf *path)
+{
+	int error = 0;
+	futils__rmdir_data *data = opaque;
+	struct stat st;
+
+	if (data->depth > FUTILS_MAX_DEPTH)
+		error = futils__error_cannot_rmdir(
+			path->ptr, "directory nesting too deep");
+
+	else if ((error = p_lstat_posixly(path->ptr, &st)) < 0) {
+		if (errno == ENOENT)
+			error = 0;
+		else if (errno == ENOTDIR) {
+			/* asked to remove a/b/c/d/e and a/b is a normal file */
+			if ((data->flags & GIT_RMDIR_REMOVE_BLOCKERS) != 0)
+				error = futils__rm_first_parent(path, data->base);
+			else
+				futils__error_cannot_rmdir(
+					path->ptr, "parent is not directory");
+		}
+		else
+			error = git_path_set_error(errno, path->ptr, "rmdir");
+	}
+
+	else if (S_ISDIR(st.st_mode)) {
+		data->depth++;
+
+		error = git_path_direach(path, 0, futils__rmdir_recurs_foreach, data);
+
+		data->depth--;
+
+		if (error < 0)
+			return error;
+
+		if (data->depth == 0 && (data->flags & GIT_RMDIR_SKIP_ROOT) != 0)
+			return error;
+
+		if ((error = p_rmdir(path->ptr)) < 0) {
+			if ((data->flags & GIT_RMDIR_SKIP_NONEMPTY) != 0 &&
+				(errno == ENOTEMPTY || errno == EEXIST || errno == EBUSY))
+				error = 0;
+			else
+				error = git_path_set_error(errno, path->ptr, "rmdir");
+		}
+	}
+
+	else if ((data->flags & GIT_RMDIR_REMOVE_FILES) != 0) {
+		if (p_unlink(path->ptr) < 0)
+			error = git_path_set_error(errno, path->ptr, "remove");
+	}
+
+	else if ((data->flags & GIT_RMDIR_SKIP_NONEMPTY) == 0)
+		error = futils__error_cannot_rmdir(path->ptr, "still present");
+
+	return error;
+}
+
+static int futils__rmdir_empty_parent(void *opaque, const char *path)
+{
+	futils__rmdir_data *data = opaque;
+	int error = 0;
+
+	if (strlen(path) <= data->baselen)
+		error = GIT_ITEROVER;
+
+	else if (p_rmdir(path) < 0) {
+		int en = errno;
+
+		if (en == ENOENT || en == ENOTDIR) {
+			/* do nothing */
+		} else if ((data->flags & GIT_RMDIR_SKIP_NONEMPTY) == 0 &&
+			en == EBUSY) {
+			error = git_path_set_error(errno, path, "rmdir");
+		} else if (en == ENOTEMPTY || en == EEXIST || en == EBUSY) {
+			error = GIT_ITEROVER;
+		} else {
+			error = git_path_set_error(errno, path, "rmdir");
+		}
+	}
+
+	return error;
+}
+
+int git_futils_rmdir_r(
+	const char *path, const char *base, uint32_t flags)
+{
+	int error;
+	git_buf fullpath = GIT_BUF_INIT;
+	futils__rmdir_data data;
+
+	/* build path and find "root" where we should start calling mkdir */
+	if (git_path_join_unrooted(&fullpath, path, base, NULL) < 0)
+		return -1;
+
+	memset(&data, 0, sizeof(data));
+	data.base    = base ? base : "";
+	data.baselen = base ? strlen(base) : 0;
+	data.flags   = flags;
+
+	error = futils__rmdir_recurs_foreach(&data, &fullpath);
+
+	/* remove now-empty parents if requested */
+	if (!error && (flags & GIT_RMDIR_EMPTY_PARENTS) != 0)
+		error = git_path_walk_up(
+			&fullpath, base, futils__rmdir_empty_parent, &data);
+
+	if (error == GIT_ITEROVER) {
+		giterr_clear();
+		error = 0;
+	}
+
+	git_buf_free(&fullpath);
+
+	return error;
+}
+
+int git_futils_fake_symlink(const char *old, const char *new)
+{
+	int retcode = GIT_ERROR;
+	int fd = git_futils_creat_withpath(new, 0755, 0644);
+	if (fd >= 0) {
+		retcode = p_write(fd, old, strlen(old));
+		p_close(fd);
+	}
+	return retcode;
+}
+
+static int cp_by_fd(int ifd, int ofd, bool close_fd_when_done)
+{
+	int error = 0;
+	char buffer[FILEIO_BUFSIZE];
+	ssize_t len = 0;
+
+	while (!error && (len = p_read(ifd, buffer, sizeof(buffer))) > 0)
+		/* p_write() does not have the same semantics as write().  It loops
+		 * internally and will return 0 when it has completed writing.
+		 */
+		error = p_write(ofd, buffer, len);
+
+	if (len < 0) {
+		giterr_set(GITERR_OS, "read error while copying file");
+		error = (int)len;
+	}
+
+	if (error < 0)
+		giterr_set(GITERR_OS, "write error while copying file");
+
+	if (close_fd_when_done) {
+		p_close(ifd);
+		p_close(ofd);
+	}
+
+	return error;
+}
+
+int git_futils_cp(const char *from, const char *to, mode_t filemode)
+{
+	int ifd, ofd;
+
+	if ((ifd = git_futils_open_ro(from)) < 0)
+		return ifd;
+
+	if ((ofd = p_open(to, O_WRONLY | O_CREAT | O_EXCL, filemode)) < 0) {
+		p_close(ifd);
+		return git_path_set_error(errno, to, "open for writing");
+	}
+
+	return cp_by_fd(ifd, ofd, true);
+}
+
+int git_futils_touch(const char *path, time_t *when)
+{
+	struct p_timeval times[2];
+	int ret;
+
+	times[0].tv_sec =  times[1].tv_sec  = when ? *when : time(NULL);
+	times[0].tv_usec = times[1].tv_usec = 0;
+
+	ret = p_utimes(path, times);
+
+	return (ret < 0) ? git_path_set_error(errno, path, "touch") : 0;
+}
+
+static int cp_link(const char *from, const char *to, size_t link_size)
+{
+	int error = 0;
+	ssize_t read_len;
+	char *link_data;
+	size_t alloc_size;
+
+	GITERR_CHECK_ALLOC_ADD(&alloc_size, link_size, 1);
+	link_data = git__malloc(alloc_size);
+	GITERR_CHECK_ALLOC(link_data);
+
+	read_len = p_readlink(from, link_data, link_size);
+	if (read_len != (ssize_t)link_size) {
+		giterr_set(GITERR_OS, "failed to read symlink data for '%s'", from);
+		error = -1;
+	}
+	else {
+		link_data[read_len] = '\0';
+
+		if (p_symlink(link_data, to) < 0) {
+			giterr_set(GITERR_OS, "could not symlink '%s' as '%s'",
+				link_data, to);
+			error = -1;
+		}
+	}
+
+	git__free(link_data);
+	return error;
+}
+
+typedef struct {
+	const char *to_root;
+	git_buf to;
+	ssize_t from_prefix;
+	uint32_t flags;
+	uint32_t mkdir_flags;
+	mode_t dirmode;
+} cp_r_info;
+
+#define GIT_CPDIR__MKDIR_DONE_FOR_TO_ROOT (1u << 10)
+
+static int _cp_r_mkdir(cp_r_info *info, git_buf *from)
+{
+	int error = 0;
+
+	/* create root directory the first time we need to create a directory */
+	if ((info->flags & GIT_CPDIR__MKDIR_DONE_FOR_TO_ROOT) == 0) {
+		error = git_futils_mkdir(
+			info->to_root, info->dirmode,
+			(info->flags & GIT_CPDIR_CHMOD_DIRS) ? GIT_MKDIR_CHMOD : 0);
+
+		info->flags |= GIT_CPDIR__MKDIR_DONE_FOR_TO_ROOT;
+	}
+
+	/* create directory with root as base to prevent excess chmods */
+	if (!error)
+		error = git_futils_mkdir_relative(
+			from->ptr + info->from_prefix, info->to_root,
+			info->dirmode, info->mkdir_flags, NULL);
+
+	return error;
+}
+
+static int _cp_r_callback(void *ref, git_buf *from)
+{
+	int error = 0;
+	cp_r_info *info = ref;
+	struct stat from_st, to_st;
+	bool exists = false;
+
+	if ((info->flags & GIT_CPDIR_COPY_DOTFILES) == 0 &&
+		from->ptr[git_path_basename_offset(from)] == '.')
+		return 0;
+
+	if ((error = git_buf_joinpath(
+			&info->to, info->to_root, from->ptr + info->from_prefix)) < 0)
+		return error;
+
+	if (!(error = git_path_lstat(info->to.ptr, &to_st)))
+		exists = true;
+	else if (error != GIT_ENOTFOUND)
+		return error;
+	else {
+		giterr_clear();
+		error = 0;
+	}
+
+	if ((error = git_path_lstat(from->ptr, &from_st)) < 0)
+		return error;
+
+	if (S_ISDIR(from_st.st_mode)) {
+		mode_t oldmode = info->dirmode;
+
+		/* if we are not chmod'ing, then overwrite dirmode */
+		if ((info->flags & GIT_CPDIR_CHMOD_DIRS) == 0)
+			info->dirmode = from_st.st_mode;
+
+		/* make directory now if CREATE_EMPTY_DIRS is requested and needed */
+		if (!exists && (info->flags & GIT_CPDIR_CREATE_EMPTY_DIRS) != 0)
+			error = _cp_r_mkdir(info, from);
+
+		/* recurse onto target directory */
+		if (!error && (!exists || S_ISDIR(to_st.st_mode)))
+			error = git_path_direach(from, 0, _cp_r_callback, info);
+
+		if (oldmode != 0)
+			info->dirmode = oldmode;
+
+		return error;
+	}
+
+	if (exists) {
+		if ((info->flags & GIT_CPDIR_OVERWRITE) == 0)
+			return 0;
+
+		if (p_unlink(info->to.ptr) < 0) {
+			giterr_set(GITERR_OS, "cannot overwrite existing file '%s'",
+				info->to.ptr);
+			return GIT_EEXISTS;
+		}
+	}
+
+	/* Done if this isn't a regular file or a symlink */
+	if (!S_ISREG(from_st.st_mode) &&
+		(!S_ISLNK(from_st.st_mode) ||
+		 (info->flags & GIT_CPDIR_COPY_SYMLINKS) == 0))
+		return 0;
+
+	/* Make container directory on demand if needed */
+	if ((info->flags & GIT_CPDIR_CREATE_EMPTY_DIRS) == 0 &&
+		(error = _cp_r_mkdir(info, from)) < 0)
+		return error;
+
+	/* make symlink or regular file */
+	if (info->flags & GIT_CPDIR_LINK_FILES) {
+		if ((error = p_link(from->ptr, info->to.ptr)) < 0)
+			giterr_set(GITERR_OS, "failed to link '%s'", from->ptr);
+	} else if (S_ISLNK(from_st.st_mode)) {
+		error = cp_link(from->ptr, info->to.ptr, (size_t)from_st.st_size);
+	} else {
+		mode_t usemode = from_st.st_mode;
+
+		if ((info->flags & GIT_CPDIR_SIMPLE_TO_MODE) != 0)
+			usemode = GIT_PERMS_FOR_WRITE(usemode);
+
+		error = git_futils_cp(from->ptr, info->to.ptr, usemode);
+	}
+
+	return error;
+}
+
+int git_futils_cp_r(
+	const char *from,
+	const char *to,
+	uint32_t flags,
+	mode_t dirmode)
+{
+	int error;
+	git_buf path = GIT_BUF_INIT;
+	cp_r_info info;
+
+	if (git_buf_joinpath(&path, from, "") < 0) /* ensure trailing slash */
+		return -1;
+
+	memset(&info, 0, sizeof(info));
+	info.to_root = to;
+	info.flags   = flags;
+	info.dirmode = dirmode;
+	info.from_prefix = path.size;
+	git_buf_init(&info.to, 0);
+
+	/* precalculate mkdir flags */
+	if ((flags & GIT_CPDIR_CREATE_EMPTY_DIRS) == 0) {
+		/* if not creating empty dirs, then use mkdir to create the path on
+		 * demand right before files are copied.
+		 */
+		info.mkdir_flags = GIT_MKDIR_PATH | GIT_MKDIR_SKIP_LAST;
+		if ((flags & GIT_CPDIR_CHMOD_DIRS) != 0)
+			info.mkdir_flags |= GIT_MKDIR_CHMOD_PATH;
+	} else {
+		/* otherwise, we will do simple mkdir as directories are encountered */
+		info.mkdir_flags =
+			((flags & GIT_CPDIR_CHMOD_DIRS) != 0) ? GIT_MKDIR_CHMOD : 0;
+	}
+
+	error = _cp_r_callback(&info, &path);
+
+	git_buf_free(&path);
+	git_buf_free(&info.to);
+
+	return error;
+}
+
+int git_futils_filestamp_check(
+	git_futils_filestamp *stamp, const char *path)
+{
+	struct stat st;
+
+	/* if the stamp is NULL, then always reload */
+	if (stamp == NULL)
+		return 1;
+
+	if (p_stat(path, &st) < 0)
+		return GIT_ENOTFOUND;
+
+	if (stamp->mtime.tv_sec == st.st_mtime &&
+#if defined(GIT_USE_NSEC)
+		stamp->mtime.tv_nsec == st.st_mtime_nsec &&
+#endif
+		stamp->size  == (git_off_t)st.st_size   &&
+		stamp->ino   == (unsigned int)st.st_ino)
+		return 0;
+
+	stamp->mtime.tv_sec = st.st_mtime;
+#if defined(GIT_USE_NSEC)
+	stamp->mtime.tv_nsec = st.st_mtime_nsec;
+#endif
+	stamp->size  = (git_off_t)st.st_size;
+	stamp->ino   = (unsigned int)st.st_ino;
+
+	return 1;
+}
+
+void git_futils_filestamp_set(
+	git_futils_filestamp *target, const git_futils_filestamp *source)
+{
+	assert(target);
+
+	if (source)
+		memcpy(target, source, sizeof(*target));
+	else
+		memset(target, 0, sizeof(*target));
+}
+
+
+void git_futils_filestamp_set_from_stat(
+	git_futils_filestamp *stamp, struct stat *st)
+{
+	if (st) {
+		stamp->mtime.tv_sec = st->st_mtime;
+#if defined(GIT_USE_NSEC)
+		stamp->mtime.tv_nsec = st->st_mtime_nsec;
+#else
+		stamp->mtime.tv_nsec = 0;
+#endif
+		stamp->size  = (git_off_t)st->st_size;
+		stamp->ino   = (unsigned int)st->st_ino;
+	} else {
+		memset(stamp, 0, sizeof(*stamp));
+	}
+}
+
+int git_futils_fsync_dir(const char *path)
+{
+#ifdef GIT_WIN32
+	GIT_UNUSED(path);
+	return 0;
+#else
+	int fd, error = -1;
+
+	if ((fd = p_open(path, O_RDONLY)) < 0) {
+		giterr_set(GITERR_OS, "failed to open directory '%s' for fsync", path);
+		return -1;
+	}
+
+	if ((error = p_fsync(fd)) < 0)
+		giterr_set(GITERR_OS, "failed to fsync directory '%s'", path);
+
+	p_close(fd);
+	return error;
+#endif
+}
+
+int git_futils_fsync_parent(const char *path)
+{
+	char *parent;
+	int error;
+
+	if ((parent = git_path_dirname(path)) == NULL)
+		return -1;
+
+	error = git_futils_fsync_dir(parent);
+	git__free(parent);
+	return error;
+}

vendor/libgit2-sys/libgit2/src/fileops.h

diff --git a/vendor/libgit2-sys/libgit2/src/fileops.h b/vendor/libgit2-sys/libgit2/src/fileops.h
new file mode 100644
index 0000000..2844ece
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/fileops.h
@@ -0,0 +1,390 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_fileops_h__
+#define INCLUDE_fileops_h__
+
+#include "common.h"
+
+#include "map.h"
+#include "posix.h"
+#include "path.h"
+#include "pool.h"
+#include "strmap.h"
+#include "oid.h"
+
+/**
+ * Filebuffer methods
+ *
+ * Read whole files into an in-memory buffer for processing
+ */
+extern int git_futils_readbuffer(git_buf *obj, const char *path);
+extern int git_futils_readbuffer_updated(
+	git_buf *obj, const char *path, git_oid *checksum, int *updated);
+extern int git_futils_readbuffer_fd(git_buf *obj, git_file fd, size_t len);
+
+/* Additional constants for `git_futils_writebuffer`'s `open_flags`.  We
+ * support these internally and they will be removed before the `open` call.
+ */
+#ifndef O_FSYNC
+# define O_FSYNC (1 << 31)
+#endif
+
+extern int git_futils_writebuffer(
+	const git_buf *buf, const char *path, int open_flags, mode_t mode);
+
+/**
+ * File utils
+ *
+ * These are custom filesystem-related helper methods. They are
+ * rather high level, and wrap the underlying POSIX methods
+ *
+ * All these methods return 0 on success,
+ * or an error code on failure and an error message is set.
+ */
+
+/**
+ * Create and open a file, while also
+ * creating all the folders in its path
+ */
+extern int git_futils_creat_withpath(const char *path, const mode_t dirmode, const mode_t mode);
+
+/**
+ * Create and open a process-locked file
+ */
+extern int git_futils_creat_locked(const char *path, const mode_t mode);
+
+/**
+ * Create and open a process-locked file, while
+ * also creating all the folders in its path
+ */
+extern int git_futils_creat_locked_withpath(const char *path, const mode_t dirmode, const mode_t mode);
+
+/**
+ * Create a path recursively.
+ */
+extern int git_futils_mkdir_r(const char *path, const mode_t mode);
+
+/**
+ * Flags to pass to `git_futils_mkdir`.
+ *
+ * * GIT_MKDIR_EXCL is "exclusive" - i.e. generate an error if dir exists.
+ * * GIT_MKDIR_PATH says to make all components in the path.
+ * * GIT_MKDIR_CHMOD says to chmod the final directory entry after creation
+ * * GIT_MKDIR_CHMOD_PATH says to chmod each directory component in the path
+ * * GIT_MKDIR_SKIP_LAST says to leave off the last element of the path
+ * * GIT_MKDIR_SKIP_LAST2 says to leave off the last 2 elements of the path
+ * * GIT_MKDIR_VERIFY_DIR says confirm final item is a dir, not just EEXIST
+ * * GIT_MKDIR_REMOVE_FILES says to remove files and recreate dirs
+ * * GIT_MKDIR_REMOVE_SYMLINKS says to remove symlinks and recreate dirs
+ *
+ * Note that the chmod options will be executed even if the directory already
+ * exists, unless GIT_MKDIR_EXCL is given.
+ */
+typedef enum {
+	GIT_MKDIR_EXCL = 1,
+	GIT_MKDIR_PATH = 2,
+	GIT_MKDIR_CHMOD = 4,
+	GIT_MKDIR_CHMOD_PATH = 8,
+	GIT_MKDIR_SKIP_LAST = 16,
+	GIT_MKDIR_SKIP_LAST2 = 32,
+	GIT_MKDIR_VERIFY_DIR = 64,
+	GIT_MKDIR_REMOVE_FILES = 128,
+	GIT_MKDIR_REMOVE_SYMLINKS = 256,
+} git_futils_mkdir_flags;
+
+struct git_futils_mkdir_perfdata
+{
+	size_t stat_calls;
+	size_t mkdir_calls;
+	size_t chmod_calls;
+};
+
+struct git_futils_mkdir_options
+{
+	git_strmap *dir_map;
+	git_pool *pool;
+	struct git_futils_mkdir_perfdata perfdata;
+};
+
+/**
+ * Create a directory or entire path.
+ *
+ * This makes a directory (and the entire path leading up to it if requested),
+ * and optionally chmods the directory immediately after (or each part of the
+ * path if requested).
+ *
+ * @param path The path to create, relative to base.
+ * @param base Root for relative path.  These directories will never be made.
+ * @param mode The mode to use for created directories.
+ * @param flags Combination of the mkdir flags above.
+ * @param opts Extended options, or null.
+ * @return 0 on success, else error code
+ */
+extern int git_futils_mkdir_relative(const char *path, const char *base, mode_t mode, uint32_t flags, struct git_futils_mkdir_options *opts);
+
+/**
+ * Create a directory or entire path.  Similar to `git_futils_mkdir_relative`
+ * without performance data.
+ */
+extern int git_futils_mkdir(const char *path, mode_t mode, uint32_t flags);
+
+/**
+ * Create all the folders required to contain
+ * the full path of a file
+ */
+extern int git_futils_mkpath2file(const char *path, const mode_t mode);
+
+/**
+ * Flags to pass to `git_futils_rmdir_r`.
+ *
+ * * GIT_RMDIR_EMPTY_HIERARCHY - the default; remove hierarchy of empty
+ *       dirs and generate error if any files are found.
+ * * GIT_RMDIR_REMOVE_FILES    - attempt to remove files in the hierarchy.
+ * * GIT_RMDIR_SKIP_NONEMPTY   - skip non-empty directories with no error.
+ * * GIT_RMDIR_EMPTY_PARENTS   - remove containing directories up to base
+ *       if removing this item leaves them empty
+ * * GIT_RMDIR_REMOVE_BLOCKERS - remove blocking file that causes ENOTDIR
+ * * GIT_RMDIR_SKIP_ROOT       - don't remove root directory itself
+ */
+typedef enum {
+	GIT_RMDIR_EMPTY_HIERARCHY = 0,
+	GIT_RMDIR_REMOVE_FILES    = (1 << 0),
+	GIT_RMDIR_SKIP_NONEMPTY   = (1 << 1),
+	GIT_RMDIR_EMPTY_PARENTS   = (1 << 2),
+	GIT_RMDIR_REMOVE_BLOCKERS = (1 << 3),
+	GIT_RMDIR_SKIP_ROOT       = (1 << 4),
+} git_futils_rmdir_flags;
+
+/**
+ * Remove path and any files and directories beneath it.
+ *
+ * @param path Path to the top level directory to process.
+ * @param base Root for relative path.
+ * @param flags Combination of git_futils_rmdir_flags values
+ * @return 0 on success; -1 on error.
+ */
+extern int git_futils_rmdir_r(const char *path, const char *base, uint32_t flags);
+
+/**
+ * Create and open a temporary file with a `_git2_` suffix.
+ * Writes the filename into path_out.
+ * @return On success, an open file descriptor, else an error code < 0.
+ */
+extern int git_futils_mktmp(git_buf *path_out, const char *filename, mode_t mode);
+
+/**
+ * Move a file on the filesystem, create the
+ * destination path if it doesn't exist
+ */
+extern int git_futils_mv_withpath(const char *from, const char *to, const mode_t dirmode);
+
+/**
+ * Copy a file
+ *
+ * The filemode will be used for the newly created file.
+ */
+extern int git_futils_cp(
+	const char *from,
+	const char *to,
+	mode_t filemode);
+
+/**
+ * Set the files atime and mtime to the given time, or the current time
+ * if `ts` is NULL.
+ */
+extern int git_futils_touch(const char *path, time_t *when);
+
+/**
+ * Flags that can be passed to `git_futils_cp_r`.
+ *
+ * - GIT_CPDIR_CREATE_EMPTY_DIRS: create directories even if there are no
+ *   files under them (otherwise directories will only be created lazily
+ *   when a file inside them is copied).
+ * - GIT_CPDIR_COPY_SYMLINKS: copy symlinks, otherwise they are ignored.
+ * - GIT_CPDIR_COPY_DOTFILES: copy files with leading '.', otherwise ignored.
+ * - GIT_CPDIR_OVERWRITE: overwrite pre-existing files with source content,
+ *   otherwise they are silently skipped.
+ * - GIT_CPDIR_CHMOD_DIRS: explicitly chmod directories to `dirmode`
+ * - GIT_CPDIR_SIMPLE_TO_MODE: default tries to replicate the mode of the
+ *   source file to the target; with this flag, always use 0666 (or 0777 if
+ *   source has exec bits set) for target.
+ * - GIT_CPDIR_LINK_FILES will try to use hardlinks for the files
+ */
+typedef enum {
+	GIT_CPDIR_CREATE_EMPTY_DIRS = (1u << 0),
+	GIT_CPDIR_COPY_SYMLINKS     = (1u << 1),
+	GIT_CPDIR_COPY_DOTFILES     = (1u << 2),
+	GIT_CPDIR_OVERWRITE         = (1u << 3),
+	GIT_CPDIR_CHMOD_DIRS        = (1u << 4),
+	GIT_CPDIR_SIMPLE_TO_MODE    = (1u << 5),
+	GIT_CPDIR_LINK_FILES        = (1u << 6),
+} git_futils_cpdir_flags;
+
+/**
+ * Copy a directory tree.
+ *
+ * This copies directories and files from one root to another.  You can
+ * pass a combinationof GIT_CPDIR flags as defined above.
+ *
+ * If you pass the CHMOD flag, then the dirmode will be applied to all
+ * directories that are created during the copy, overiding the natural
+ * permissions.  If you do not pass the CHMOD flag, then the dirmode
+ * will actually be copied from the source files and the `dirmode` arg
+ * will be ignored.
+ */
+extern int git_futils_cp_r(
+	const char *from,
+	const char *to,
+	uint32_t flags,
+	mode_t dirmode);
+
+/**
+ * Open a file readonly and set error if needed.
+ */
+extern int git_futils_open_ro(const char *path);
+
+/**
+ * Truncate a file, creating it if it doesn't exist.
+ */
+extern int git_futils_truncate(const char *path, int mode);
+
+/**
+ * Get the filesize in bytes of a file
+ */
+extern git_off_t git_futils_filesize(git_file fd);
+
+#define GIT_PERMS_IS_EXEC(MODE)		(((MODE) & 0111) != 0)
+#define GIT_PERMS_CANONICAL(MODE)	(GIT_PERMS_IS_EXEC(MODE) ? 0755 : 0644)
+#define GIT_PERMS_FOR_WRITE(MODE)   (GIT_PERMS_IS_EXEC(MODE) ? 0777 : 0666)
+
+#define GIT_MODE_PERMS_MASK			0777
+#define GIT_MODE_TYPE_MASK			0170000
+#define GIT_MODE_TYPE(MODE)			((MODE) & GIT_MODE_TYPE_MASK)
+#define GIT_MODE_ISBLOB(MODE)		(GIT_MODE_TYPE(MODE) == GIT_MODE_TYPE(GIT_FILEMODE_BLOB))
+
+/**
+ * Convert a mode_t from the OS to a legal git mode_t value.
+ */
+extern mode_t git_futils_canonical_mode(mode_t raw_mode);
+
+
+/**
+ * Read-only map all or part of a file into memory.
+ * When possible this function should favor a virtual memory
+ * style mapping over some form of malloc()+read(), as the
+ * data access will be random and is not likely to touch the
+ * majority of the region requested.
+ *
+ * @param out buffer to populate with the mapping information.
+ * @param fd open descriptor to configure the mapping from.
+ * @param begin first byte to map, this should be page aligned.
+ * @param len number of bytes to map.
+ * @return
+ * - 0 on success;
+ * - -1 on error.
+ */
+extern int git_futils_mmap_ro(
+	git_map *out,
+	git_file fd,
+	git_off_t begin,
+	size_t len);
+
+/**
+ * Read-only map an entire file.
+ *
+ * @param out buffer to populate with the mapping information.
+ * @param path path to file to be opened.
+ * @return
+ * - 0 on success;
+ * - GIT_ENOTFOUND if not found;
+ * - -1 on an unspecified OS related error.
+ */
+extern int git_futils_mmap_ro_file(
+	git_map *out,
+	const char *path);
+
+/**
+ * Release the memory associated with a previous memory mapping.
+ * @param map the mapping description previously configured.
+ */
+extern void git_futils_mmap_free(git_map *map);
+
+/**
+ * Create a "fake" symlink (text file containing the target path).
+ *
+ * @param new symlink file to be created
+ * @param old original symlink target
+ * @return 0 on success, -1 on error
+ */
+extern int git_futils_fake_symlink(const char *new, const char *old);
+
+/**
+ * A file stamp represents a snapshot of information about a file that can
+ * be used to test if the file changes.  This portable implementation is
+ * based on stat data about that file, but it is possible that OS specific
+ * versions could be implemented in the future.
+ */
+typedef struct {
+	struct timespec mtime;
+	git_off_t  size;
+	unsigned int ino;
+} git_futils_filestamp;
+
+/**
+ * Compare stat information for file with reference info.
+ *
+ * This function updates the file stamp to current data for the given path
+ * and returns 0 if the file is up-to-date relative to the prior setting,
+ * 1 if the file has been changed, or GIT_ENOTFOUND if the file doesn't
+ * exist.  This will not call giterr_set, so you must set the error if you
+ * plan to return an error.
+ *
+ * @param stamp File stamp to be checked
+ * @param path Path to stat and check if changed
+ * @return 0 if up-to-date, 1 if out-of-date, GIT_ENOTFOUND if cannot stat
+ */
+extern int git_futils_filestamp_check(
+	git_futils_filestamp *stamp, const char *path);
+
+/**
+ * Set or reset file stamp data
+ *
+ * This writes the target file stamp.  If the source is NULL, this will set
+ * the target stamp to values that will definitely be out of date.  If the
+ * source is not NULL, this copies the source values to the target.
+ *
+ * @param tgt File stamp to write to
+ * @param src File stamp to copy from or NULL to clear the target
+ */
+extern void git_futils_filestamp_set(
+	git_futils_filestamp *tgt, const git_futils_filestamp *src);
+
+/**
+ * Set file stamp data from stat structure
+ */
+extern void git_futils_filestamp_set_from_stat(
+	git_futils_filestamp *stamp, struct stat *st);
+
+/**
+ * `fsync` the parent directory of the given path, if `fsync` is
+ * supported for directories on this platform.
+ *
+ * @param path Path of the directory to sync.
+ * @return 0 on success, -1 on error
+ */
+extern int git_futils_fsync_dir(const char *path);
+
+/**
+ * `fsync` the parent directory of the given path, if `fsync` is
+ * supported for directories on this platform.
+ *
+ * @param path Path of the file whose parent directory should be synced.
+ * @return 0 on success, -1 on error
+ */
+extern int git_futils_fsync_parent(const char *path);
+
+#endif

vendor/libgit2-sys/libgit2/src/filter.c

diff --git a/vendor/libgit2-sys/libgit2/src/filter.c b/vendor/libgit2-sys/libgit2/src/filter.c
new file mode 100644
index 0000000..6ab0979
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/filter.c
@@ -0,0 +1,1031 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "filter.h"
+
+#include "common.h"
+#include "fileops.h"
+#include "hash.h"
+#include "repository.h"
+#include "global.h"
+#include "git2/sys/filter.h"
+#include "git2/config.h"
+#include "blob.h"
+#include "attr_file.h"
+#include "array.h"
+
+struct git_filter_source {
+	git_repository *repo;
+	const char     *path;
+	git_oid         oid;  /* zero if unknown (which is likely) */
+	uint16_t        filemode; /* zero if unknown */
+	git_filter_mode_t mode;
+	uint32_t        flags;
+};
+
+typedef struct {
+	const char *filter_name;
+	git_filter *filter;
+	void *payload;
+} git_filter_entry;
+
+struct git_filter_list {
+	git_array_t(git_filter_entry) filters;
+	git_filter_source source;
+	git_buf *temp_buf;
+	char path[GIT_FLEX_ARRAY];
+};
+
+typedef struct {
+	char *filter_name;
+	git_filter *filter;
+	int priority;
+	int initialized;
+	size_t nattrs, nmatches;
+	char *attrdata;
+	const char *attrs[GIT_FLEX_ARRAY];
+} git_filter_def;
+
+static int filter_def_priority_cmp(const void *a, const void *b)
+{
+	int pa = ((const git_filter_def *)a)->priority;
+	int pb = ((const git_filter_def *)b)->priority;
+	return (pa < pb) ? -1 : (pa > pb) ? 1 : 0;
+}
+
+struct git_filter_registry {
+	git_rwlock lock;
+	git_vector filters;
+};
+
+static struct git_filter_registry filter_registry;
+
+static void git_filter_global_shutdown(void);
+
+
+static int filter_def_scan_attrs(
+	git_buf *attrs, size_t *nattr, size_t *nmatch, const char *attr_str)
+{
+	const char *start, *scan = attr_str;
+	int has_eq;
+
+	*nattr = *nmatch = 0;
+
+	if (!scan)
+		return 0;
+
+	while (*scan) {
+		while (git__isspace(*scan)) scan++;
+
+		for (start = scan, has_eq = 0; *scan && !git__isspace(*scan); ++scan) {
+			if (*scan == '=')
+				has_eq = 1;
+		}
+
+		if (scan > start) {
+			(*nattr)++;
+			if (has_eq || *start == '-' || *start == '+' || *start == '!')
+				(*nmatch)++;
+
+			if (has_eq)
+				git_buf_putc(attrs, '=');
+			git_buf_put(attrs, start, scan - start);
+			git_buf_putc(attrs, '\0');
+		}
+	}
+
+	return 0;
+}
+
+static void filter_def_set_attrs(git_filter_def *fdef)
+{
+	char *scan = fdef->attrdata;
+	size_t i;
+
+	for (i = 0; i < fdef->nattrs; ++i) {
+		const char *name, *value;
+
+		switch (*scan) {
+		case '=':
+			name = scan + 1;
+			for (scan++; *scan != '='; scan++) /* find '=' */;
+			*scan++ = '\0';
+			value = scan;
+			break;
+		case '-':
+			name = scan + 1; value = git_attr__false; break;
+		case '+':
+			name = scan + 1; value = git_attr__true;  break;
+		case '!':
+			name = scan + 1; value = git_attr__unset; break;
+		default:
+			name = scan;     value = NULL; break;
+		}
+
+		fdef->attrs[i] = name;
+		fdef->attrs[i + fdef->nattrs] = value;
+
+		scan += strlen(scan) + 1;
+	}
+}
+
+static int filter_def_name_key_check(const void *key, const void *fdef)
+{
+	const char *name =
+		fdef ? ((const git_filter_def *)fdef)->filter_name : NULL;
+	return name ? git__strcmp(key, name) : -1;
+}
+
+static int filter_def_filter_key_check(const void *key, const void *fdef)
+{
+	const void *filter = fdef ? ((const git_filter_def *)fdef)->filter : NULL;
+	return (key == filter) ? 0 : -1;
+}
+
+/* Note: callers must lock the registry before calling this function */
+static int filter_registry_insert(
+	const char *name, git_filter *filter, int priority)
+{
+	git_filter_def *fdef;
+	size_t nattr = 0, nmatch = 0, alloc_len;
+	git_buf attrs = GIT_BUF_INIT;
+
+	if (filter_def_scan_attrs(&attrs, &nattr, &nmatch, filter->attributes) < 0)
+		return -1;
+
+	GITERR_CHECK_ALLOC_MULTIPLY(&alloc_len, nattr, 2);
+	GITERR_CHECK_ALLOC_MULTIPLY(&alloc_len, alloc_len, sizeof(char *));
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, sizeof(git_filter_def));
+
+	fdef = git__calloc(1, alloc_len);
+	GITERR_CHECK_ALLOC(fdef);
+
+	fdef->filter_name = git__strdup(name);
+	GITERR_CHECK_ALLOC(fdef->filter_name);
+
+	fdef->filter      = filter;
+	fdef->priority    = priority;
+	fdef->nattrs      = nattr;
+	fdef->nmatches    = nmatch;
+	fdef->attrdata    = git_buf_detach(&attrs);
+
+	filter_def_set_attrs(fdef);
+
+	if (git_vector_insert(&filter_registry.filters, fdef) < 0) {
+		git__free(fdef->filter_name);
+		git__free(fdef->attrdata);
+		git__free(fdef);
+		return -1;
+	}
+
+	git_vector_sort(&filter_registry.filters);
+	return 0;
+}
+
+int git_filter_global_init(void)
+{
+	git_filter *crlf = NULL, *ident = NULL;
+	int error = 0;
+
+	if (git_rwlock_init(&filter_registry.lock) < 0)
+		return -1;
+
+	if ((error = git_vector_init(&filter_registry.filters, 2,
+		filter_def_priority_cmp)) < 0)
+		goto done;
+
+	if ((crlf = git_crlf_filter_new()) == NULL ||
+		filter_registry_insert(
+			GIT_FILTER_CRLF, crlf, GIT_FILTER_CRLF_PRIORITY) < 0 ||
+		(ident = git_ident_filter_new()) == NULL ||
+		filter_registry_insert(
+			GIT_FILTER_IDENT, ident, GIT_FILTER_IDENT_PRIORITY) < 0)
+		error = -1;
+
+	git__on_shutdown(git_filter_global_shutdown);
+
+done:
+	if (error) {
+		git_filter_free(crlf);
+		git_filter_free(ident);
+	}
+
+	return error;
+}
+
+static void git_filter_global_shutdown(void)
+{
+	size_t pos;
+	git_filter_def *fdef;
+
+	if (git_rwlock_wrlock(&filter_registry.lock) < 0)
+		return;
+
+	git_vector_foreach(&filter_registry.filters, pos, fdef) {
+		if (fdef->filter && fdef->filter->shutdown) {
+			fdef->filter->shutdown(fdef->filter);
+			fdef->initialized = false;
+		}
+
+		git__free(fdef->filter_name);
+		git__free(fdef->attrdata);
+		git__free(fdef);
+	}
+
+	git_vector_free(&filter_registry.filters);
+
+	git_rwlock_wrunlock(&filter_registry.lock);
+	git_rwlock_free(&filter_registry.lock);
+}
+
+/* Note: callers must lock the registry before calling this function */
+static int filter_registry_find(size_t *pos, const char *name)
+{
+	return git_vector_search2(
+		pos, &filter_registry.filters, filter_def_name_key_check, name);
+}
+
+/* Note: callers must lock the registry before calling this function */
+static git_filter_def *filter_registry_lookup(size_t *pos, const char *name)
+{
+	git_filter_def *fdef = NULL;
+
+	if (!filter_registry_find(pos, name))
+		fdef = git_vector_get(&filter_registry.filters, *pos);
+
+	return fdef;
+}
+
+
+int git_filter_register(
+	const char *name, git_filter *filter, int priority)
+{
+	int error;
+
+	assert(name && filter);
+
+	if (git_rwlock_wrlock(&filter_registry.lock) < 0) {
+		giterr_set(GITERR_OS, "failed to lock filter registry");
+		return -1;
+	}
+
+	if (!filter_registry_find(NULL, name)) {
+		giterr_set(
+			GITERR_FILTER, "attempt to reregister existing filter '%s'", name);
+		error = GIT_EEXISTS;
+		goto done;
+	}
+
+	error = filter_registry_insert(name, filter, priority);
+
+done:
+	git_rwlock_wrunlock(&filter_registry.lock);
+	return error;
+}
+
+int git_filter_unregister(const char *name)
+{
+	size_t pos;
+	git_filter_def *fdef;
+	int error = 0;
+
+	assert(name);
+
+	/* cannot unregister default filters */
+	if (!strcmp(GIT_FILTER_CRLF, name) || !strcmp(GIT_FILTER_IDENT, name)) {
+		giterr_set(GITERR_FILTER, "cannot unregister filter '%s'", name);
+		return -1;
+	}
+
+	if (git_rwlock_wrlock(&filter_registry.lock) < 0) {
+		giterr_set(GITERR_OS, "failed to lock filter registry");
+		return -1;
+	}
+
+	if ((fdef = filter_registry_lookup(&pos, name)) == NULL) {
+		giterr_set(GITERR_FILTER, "cannot find filter '%s' to unregister", name);
+		error = GIT_ENOTFOUND;
+		goto done;
+	}
+
+	git_vector_remove(&filter_registry.filters, pos);
+
+	if (fdef->initialized && fdef->filter && fdef->filter->shutdown) {
+		fdef->filter->shutdown(fdef->filter);
+		fdef->initialized = false;
+	}
+
+	git__free(fdef->filter_name);
+	git__free(fdef->attrdata);
+	git__free(fdef);
+
+done:
+	git_rwlock_wrunlock(&filter_registry.lock);
+	return error;
+}
+
+static int filter_initialize(git_filter_def *fdef)
+{
+	int error = 0;
+
+	if (!fdef->initialized && fdef->filter && fdef->filter->initialize) {
+		if ((error = fdef->filter->initialize(fdef->filter)) < 0)
+			return error;
+	}
+
+	fdef->initialized = true;
+	return 0;
+}
+
+git_filter *git_filter_lookup(const char *name)
+{
+	size_t pos;
+	git_filter_def *fdef;
+	git_filter *filter = NULL;
+
+	if (git_rwlock_rdlock(&filter_registry.lock) < 0) {
+		giterr_set(GITERR_OS, "failed to lock filter registry");
+		return NULL;
+	}
+
+	if ((fdef = filter_registry_lookup(&pos, name)) == NULL ||
+		(!fdef->initialized && filter_initialize(fdef) < 0))
+		goto done;
+
+	filter = fdef->filter;
+
+done:
+	git_rwlock_rdunlock(&filter_registry.lock);
+	return filter;
+}
+
+void git_filter_free(git_filter *filter)
+{
+	git__free(filter);
+}
+
+git_repository *git_filter_source_repo(const git_filter_source *src)
+{
+	return src->repo;
+}
+
+const char *git_filter_source_path(const git_filter_source *src)
+{
+	return src->path;
+}
+
+uint16_t git_filter_source_filemode(const git_filter_source *src)
+{
+	return src->filemode;
+}
+
+const git_oid *git_filter_source_id(const git_filter_source *src)
+{
+	return git_oid_iszero(&src->oid) ? NULL : &src->oid;
+}
+
+git_filter_mode_t git_filter_source_mode(const git_filter_source *src)
+{
+	return src->mode;
+}
+
+uint32_t git_filter_source_flags(const git_filter_source *src)
+{
+	return src->flags;
+}
+
+static int filter_list_new(
+	git_filter_list **out, const git_filter_source *src)
+{
+	git_filter_list *fl = NULL;
+	size_t pathlen = src->path ? strlen(src->path) : 0, alloclen;
+
+	GITERR_CHECK_ALLOC_ADD(&alloclen, sizeof(git_filter_list), pathlen);
+	GITERR_CHECK_ALLOC_ADD(&alloclen, alloclen, 1);
+
+	fl = git__calloc(1, alloclen);
+	GITERR_CHECK_ALLOC(fl);
+
+	if (src->path)
+		memcpy(fl->path, src->path, pathlen);
+	fl->source.repo = src->repo;
+	fl->source.path = fl->path;
+	fl->source.mode = src->mode;
+	fl->source.flags = src->flags;
+
+	*out = fl;
+	return 0;
+}
+
+static int filter_list_check_attributes(
+	const char ***out,
+	git_repository *repo,
+	git_attr_session *attr_session,
+	git_filter_def *fdef,
+	const git_filter_source *src)
+{
+	int error;
+	size_t i;
+	const char **strs = git__calloc(fdef->nattrs, sizeof(const char *));
+	GITERR_CHECK_ALLOC(strs);
+
+	error = git_attr_get_many_with_session(
+		strs, repo, attr_session, 0, src->path, fdef->nattrs, fdef->attrs);
+
+	/* if no values were found but no matches are needed, it's okay! */
+	if (error == GIT_ENOTFOUND && !fdef->nmatches) {
+		giterr_clear();
+		git__free((void *)strs);
+		return 0;
+	}
+
+	for (i = 0; !error && i < fdef->nattrs; ++i) {
+		const char *want = fdef->attrs[fdef->nattrs + i];
+		git_attr_t want_type, found_type;
+
+		if (!want)
+			continue;
+
+		want_type  = git_attr_value(want);
+		found_type = git_attr_value(strs[i]);
+
+		if (want_type != found_type)
+			error = GIT_ENOTFOUND;
+		else if (want_type == GIT_ATTR_VALUE_T &&
+				strcmp(want, strs[i]) &&
+				strcmp(want, "*"))
+			error = GIT_ENOTFOUND;
+	}
+
+	if (error)
+		git__free((void *)strs);
+	else
+		*out = strs;
+
+	return error;
+}
+
+int git_filter_list_new(
+	git_filter_list **out,
+	git_repository *repo,
+	git_filter_mode_t mode,
+	uint32_t flags)
+{
+	git_filter_source src = { 0 };
+	src.repo = repo;
+	src.path = NULL;
+	src.mode = mode;
+	src.flags = flags;
+	return filter_list_new(out, &src);
+}
+
+int git_filter_list__load_ext(
+	git_filter_list **filters,
+	git_repository *repo,
+	git_blob *blob, /* can be NULL */
+	const char *path,
+	git_filter_mode_t mode,
+	git_filter_options *filter_opts)
+{
+	int error = 0;
+	git_filter_list *fl = NULL;
+	git_filter_source src = { 0 };
+	git_filter_entry *fe;
+	size_t idx;
+	git_filter_def *fdef;
+
+	if (git_rwlock_rdlock(&filter_registry.lock) < 0) {
+		giterr_set(GITERR_OS, "failed to lock filter registry");
+		return -1;
+	}
+
+	src.repo = repo;
+	src.path = path;
+	src.mode = mode;
+	src.flags = filter_opts->flags;
+
+	if (blob)
+		git_oid_cpy(&src.oid, git_blob_id(blob));
+
+	git_vector_foreach(&filter_registry.filters, idx, fdef) {
+		const char **values = NULL;
+		void *payload = NULL;
+
+		if (!fdef || !fdef->filter)
+			continue;
+
+		if (fdef->nattrs > 0) {
+			error = filter_list_check_attributes(
+				&values, repo, filter_opts->attr_session, fdef, &src);
+
+			if (error == GIT_ENOTFOUND) {
+				error = 0;
+				continue;
+			} else if (error < 0)
+				break;
+		}
+
+		if (!fdef->initialized && (error = filter_initialize(fdef)) < 0)
+			break;
+
+		if (fdef->filter->check)
+			error = fdef->filter->check(
+				fdef->filter, &payload, &src, values);
+
+		git__free((void *)values);
+
+		if (error == GIT_PASSTHROUGH)
+			error = 0;
+		else if (error < 0)
+			break;
+		else {
+			if (!fl) {
+				if ((error = filter_list_new(&fl, &src)) < 0)
+					break;
+
+				fl->temp_buf = filter_opts->temp_buf;
+			}
+
+			fe = git_array_alloc(fl->filters);
+			GITERR_CHECK_ALLOC(fe);
+
+			fe->filter = fdef->filter;
+			fe->filter_name = fdef->filter_name;
+			fe->payload = payload;
+		}
+	}
+
+	git_rwlock_rdunlock(&filter_registry.lock);
+
+	if (error && fl != NULL) {
+		git_array_clear(fl->filters);
+		git__free(fl);
+		fl = NULL;
+	}
+
+	*filters = fl;
+	return error;
+}
+
+int git_filter_list_load(
+	git_filter_list **filters,
+	git_repository *repo,
+	git_blob *blob, /* can be NULL */
+	const char *path,
+	git_filter_mode_t mode,
+	uint32_t flags)
+{
+	git_filter_options filter_opts = GIT_FILTER_OPTIONS_INIT;
+
+	filter_opts.flags = flags;
+
+	return git_filter_list__load_ext(
+		filters, repo, blob, path, mode, &filter_opts);
+}
+
+void git_filter_list_free(git_filter_list *fl)
+{
+	uint32_t i;
+
+	if (!fl)
+		return;
+
+	for (i = 0; i < git_array_size(fl->filters); ++i) {
+		git_filter_entry *fe = git_array_get(fl->filters, i);
+		if (fe->filter->cleanup)
+			fe->filter->cleanup(fe->filter, fe->payload);
+	}
+
+	git_array_clear(fl->filters);
+	git__free(fl);
+}
+
+int git_filter_list_contains(
+	git_filter_list *fl,
+	const char *name)
+{
+	size_t i;
+
+	assert(name);
+
+	if (!fl)
+		return 0;
+
+	for (i = 0; i < fl->filters.size; i++) {
+		if (strcmp(fl->filters.ptr[i].filter_name, name) == 0)
+			return 1;
+	}
+
+	return 0;
+}
+
+int git_filter_list_push(
+	git_filter_list *fl, git_filter *filter, void *payload)
+{
+	int error = 0;
+	size_t pos;
+	git_filter_def *fdef = NULL;
+	git_filter_entry *fe;
+
+	assert(fl && filter);
+
+	if (git_rwlock_rdlock(&filter_registry.lock) < 0) {
+		giterr_set(GITERR_OS, "failed to lock filter registry");
+		return -1;
+	}
+
+	if (git_vector_search2(
+			&pos, &filter_registry.filters,
+			filter_def_filter_key_check, filter) == 0)
+		fdef = git_vector_get(&filter_registry.filters, pos);
+
+	git_rwlock_rdunlock(&filter_registry.lock);
+
+	if (fdef == NULL) {
+		giterr_set(GITERR_FILTER, "cannot use an unregistered filter");
+		return -1;
+	}
+
+	if (!fdef->initialized && (error = filter_initialize(fdef)) < 0)
+		return error;
+
+	fe = git_array_alloc(fl->filters);
+	GITERR_CHECK_ALLOC(fe);
+	fe->filter  = filter;
+	fe->payload = payload;
+
+	return 0;
+}
+
+size_t git_filter_list_length(const git_filter_list *fl)
+{
+	return fl ? git_array_size(fl->filters) : 0;
+}
+
+struct buf_stream {
+	git_writestream parent;
+	git_buf *target;
+	bool complete;
+};
+
+static int buf_stream_write(
+	git_writestream *s, const char *buffer, size_t len)
+{
+	struct buf_stream *buf_stream = (struct buf_stream *)s;
+	assert(buf_stream);
+
+	assert(buf_stream->complete == 0);
+
+	return git_buf_put(buf_stream->target, buffer, len);
+}
+
+static int buf_stream_close(git_writestream *s)
+{
+	struct buf_stream *buf_stream = (struct buf_stream *)s;
+	assert(buf_stream);
+
+	assert(buf_stream->complete == 0);
+	buf_stream->complete = 1;
+
+	return 0;
+}
+
+static void buf_stream_free(git_writestream *s)
+{
+	GIT_UNUSED(s);
+}
+
+static void buf_stream_init(struct buf_stream *writer, git_buf *target)
+{
+	memset(writer, 0, sizeof(struct buf_stream));
+
+	writer->parent.write = buf_stream_write;
+	writer->parent.close = buf_stream_close;
+	writer->parent.free = buf_stream_free;
+	writer->target = target;
+
+	git_buf_clear(target);
+}
+
+int git_filter_list_apply_to_data(
+	git_buf *tgt, git_filter_list *filters, git_buf *src)
+{
+	struct buf_stream writer;
+	int error;
+
+	git_buf_sanitize(tgt);
+	git_buf_sanitize(src);
+
+	if (!filters) {
+		git_buf_attach_notowned(tgt, src->ptr, src->size);
+		return 0;
+	}
+
+	buf_stream_init(&writer, tgt);
+
+	if ((error = git_filter_list_stream_data(filters, src,
+		&writer.parent)) < 0)
+			return error;
+
+	assert(writer.complete);
+	return error;
+}
+
+int git_filter_list_apply_to_file(
+	git_buf *out,
+	git_filter_list *filters,
+	git_repository *repo,
+	const char *path)
+{
+	struct buf_stream writer;
+	int error;
+
+	buf_stream_init(&writer, out);
+
+	if ((error = git_filter_list_stream_file(
+		filters, repo, path, &writer.parent)) < 0)
+			return error;
+
+	assert(writer.complete);
+	return error;
+}
+
+static int buf_from_blob(git_buf *out, git_blob *blob)
+{
+	git_off_t rawsize = git_blob_rawsize(blob);
+
+	if (!git__is_sizet(rawsize)) {
+		giterr_set(GITERR_OS, "blob is too large to filter");
+		return -1;
+	}
+
+	git_buf_attach_notowned(out, git_blob_rawcontent(blob), (size_t)rawsize);
+	return 0;
+}
+
+int git_filter_list_apply_to_blob(
+	git_buf *out,
+	git_filter_list *filters,
+	git_blob *blob)
+{
+	struct buf_stream writer;
+	int error;
+
+	buf_stream_init(&writer, out);
+
+	if ((error = git_filter_list_stream_blob(
+		filters, blob, &writer.parent)) < 0)
+			return error;
+
+	assert(writer.complete);
+	return error;
+}
+
+struct proxy_stream {
+	git_writestream parent;
+	git_filter *filter;
+	const git_filter_source *source;
+	void **payload;
+	git_buf input;
+	git_buf temp_buf;
+	git_buf *output;
+	git_writestream *target;
+};
+
+static int proxy_stream_write(
+	git_writestream *s, const char *buffer, size_t len)
+{
+	struct proxy_stream *proxy_stream = (struct proxy_stream *)s;
+	assert(proxy_stream);
+
+	return git_buf_put(&proxy_stream->input, buffer, len);
+}
+
+static int proxy_stream_close(git_writestream *s)
+{
+	struct proxy_stream *proxy_stream = (struct proxy_stream *)s;
+	git_buf *writebuf;
+	int error;
+
+	assert(proxy_stream);
+
+	error = proxy_stream->filter->apply(
+		proxy_stream->filter,
+		proxy_stream->payload,
+		proxy_stream->output,
+		&proxy_stream->input,
+		proxy_stream->source);
+
+	if (error == GIT_PASSTHROUGH) {
+		writebuf = &proxy_stream->input;
+	} else if (error == 0) {
+		git_buf_sanitize(proxy_stream->output);
+		writebuf = proxy_stream->output;
+	} else {
+		return error;
+	}
+
+	if ((error = proxy_stream->target->write(
+			proxy_stream->target, writebuf->ptr, writebuf->size)) == 0)
+		error = proxy_stream->target->close(proxy_stream->target);
+
+	return error;
+}
+
+static void proxy_stream_free(git_writestream *s)
+{
+	struct proxy_stream *proxy_stream = (struct proxy_stream *)s;
+	assert(proxy_stream);
+
+	git_buf_free(&proxy_stream->input);
+	git_buf_free(&proxy_stream->temp_buf);
+	git__free(proxy_stream);
+}
+
+static int proxy_stream_init(
+	git_writestream **out,
+	git_filter *filter,
+	git_buf *temp_buf,
+	void **payload,
+	const git_filter_source *source,
+	git_writestream *target)
+{
+	struct proxy_stream *proxy_stream = git__calloc(1, sizeof(struct proxy_stream));
+	GITERR_CHECK_ALLOC(proxy_stream);
+
+	proxy_stream->parent.write = proxy_stream_write;
+	proxy_stream->parent.close = proxy_stream_close;
+	proxy_stream->parent.free = proxy_stream_free;
+	proxy_stream->filter = filter;
+	proxy_stream->payload = payload;
+	proxy_stream->source = source;
+	proxy_stream->target = target;
+	proxy_stream->output = temp_buf ? temp_buf : &proxy_stream->temp_buf;
+
+	if (temp_buf)
+		git_buf_clear(temp_buf);
+
+	*out = (git_writestream *)proxy_stream;
+	return 0;
+}
+
+static int stream_list_init(
+	git_writestream **out,
+	git_vector *streams,
+	git_filter_list *filters,
+	git_writestream *target)
+{
+	git_writestream *last_stream = target;
+	size_t i;
+	int error = 0;
+
+	*out = NULL;
+
+	if (!filters) {
+		*out = target;
+		return 0;
+	}
+
+	/* Create filters last to first to get the chaining direction */
+	for (i = 0; i < git_array_size(filters->filters); ++i) {
+		size_t filter_idx = (filters->source.mode == GIT_FILTER_TO_WORKTREE) ?
+			git_array_size(filters->filters) - 1 - i : i;
+		git_filter_entry *fe = git_array_get(filters->filters, filter_idx);
+		git_writestream *filter_stream;
+
+		assert(fe->filter->stream || fe->filter->apply);
+
+		/* If necessary, create a stream that proxies the traditional
+		 * application.
+		 */
+		if (fe->filter->stream)
+			error = fe->filter->stream(&filter_stream, fe->filter,
+				&fe->payload, &filters->source, last_stream);
+		else
+			/* Create a stream that proxies the one-shot apply */
+			error = proxy_stream_init(&filter_stream, fe->filter,
+				filters->temp_buf, &fe->payload, &filters->source,
+				last_stream);
+
+		if (error < 0)
+			goto out;
+
+		git_vector_insert(streams, filter_stream);
+		last_stream = filter_stream;
+	}
+
+out:
+	if (error)
+		last_stream->close(last_stream);
+	else
+		*out = last_stream;
+
+	return error;
+}
+
+void stream_list_free(git_vector *streams)
+{
+	git_writestream *stream;
+	size_t i;
+
+	git_vector_foreach(streams, i, stream)
+		stream->free(stream);
+	git_vector_free(streams);
+}
+
+int git_filter_list_stream_file(
+	git_filter_list *filters,
+	git_repository *repo,
+	const char *path,
+	git_writestream *target)
+{
+	char buf[FILTERIO_BUFSIZE];
+	git_buf abspath = GIT_BUF_INIT;
+	const char *base = repo ? git_repository_workdir(repo) : NULL;
+	git_vector filter_streams = GIT_VECTOR_INIT;
+	git_writestream *stream_start;
+	ssize_t readlen;
+	int fd = -1, error, initialized = 0;
+
+	if ((error = stream_list_init(
+			&stream_start, &filter_streams, filters, target)) < 0 ||
+		(error = git_path_join_unrooted(&abspath, path, base, NULL)) < 0)
+		goto done;
+	initialized = 1;
+
+	if ((fd = git_futils_open_ro(abspath.ptr)) < 0) {
+		error = fd;
+		goto done;
+	}
+
+	while ((readlen = p_read(fd, buf, sizeof(buf))) > 0) {
+		if ((error = stream_start->write(stream_start, buf, readlen)) < 0)
+			goto done;
+	}
+
+	if (readlen < 0)
+		error = readlen;
+
+done:
+	if (initialized)
+		error |= stream_start->close(stream_start);
+
+	if (fd >= 0)
+		p_close(fd);
+	stream_list_free(&filter_streams);
+	git_buf_free(&abspath);
+	return error;
+}
+
+int git_filter_list_stream_data(
+	git_filter_list *filters,
+	git_buf *data,
+	git_writestream *target)
+{
+	git_vector filter_streams = GIT_VECTOR_INIT;
+	git_writestream *stream_start;
+	int error, initialized = 0;
+
+	git_buf_sanitize(data);
+
+	if ((error = stream_list_init(&stream_start, &filter_streams, filters, target)) < 0)
+		goto out;
+	initialized = 1;
+
+	if ((error = stream_start->write(
+			stream_start, data->ptr, data->size)) < 0)
+		goto out;
+
+out:
+	if (initialized)
+		error |= stream_start->close(stream_start);
+
+	stream_list_free(&filter_streams);
+	return error;
+}
+
+int git_filter_list_stream_blob(
+	git_filter_list *filters,
+	git_blob *blob,
+	git_writestream *target)
+{
+	git_buf in = GIT_BUF_INIT;
+
+	if (buf_from_blob(&in, blob) < 0)
+		return -1;
+
+	if (filters)
+		git_oid_cpy(&filters->source.oid, git_blob_id(blob));
+
+	return git_filter_list_stream_data(filters, &in, target);
+}
+
+int git_filter_init(git_filter *filter, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(filter, version, git_filter, GIT_FILTER_INIT);
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/filter.h

diff --git a/vendor/libgit2-sys/libgit2/src/filter.h b/vendor/libgit2-sys/libgit2/src/filter.h
new file mode 100644
index 0000000..b1c403b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/filter.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_filter_h__
+#define INCLUDE_filter_h__
+
+#include "common.h"
+
+#include "attr_file.h"
+#include "git2/filter.h"
+
+/* Amount of file to examine for NUL byte when checking binary-ness */
+#define GIT_FILTER_BYTES_TO_CHECK_NUL 8000
+
+/* Possible CRLF values */
+typedef enum {
+	GIT_CRLF_GUESS = -1,
+	GIT_CRLF_BINARY = 0,
+	GIT_CRLF_TEXT,
+	GIT_CRLF_INPUT,
+	GIT_CRLF_CRLF,
+	GIT_CRLF_AUTO,
+} git_crlf_t;
+
+typedef struct {
+	git_attr_session *attr_session;
+	git_buf *temp_buf;
+	uint32_t flags;
+} git_filter_options;
+
+#define GIT_FILTER_OPTIONS_INIT {0}
+
+extern int git_filter_global_init(void);
+
+extern void git_filter_free(git_filter *filter);
+
+extern int git_filter_list__load_ext(
+	git_filter_list **filters,
+	git_repository *repo,
+	git_blob *blob, /* can be NULL */
+	const char *path,
+	git_filter_mode_t mode,
+	git_filter_options *filter_opts);
+
+/*
+ * Available filters
+ */
+
+extern git_filter *git_crlf_filter_new(void);
+extern git_filter *git_ident_filter_new(void);
+
+#endif

vendor/libgit2-sys/libgit2/src/fnmatch.c

diff --git a/vendor/libgit2-sys/libgit2/src/fnmatch.c b/vendor/libgit2-sys/libgit2/src/fnmatch.c
new file mode 100644
index 0000000..3cc2a27
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/fnmatch.c
@@ -0,0 +1,248 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+/*
+ * This file contains code originally derrived from OpenBSD fnmatch.c 
+ *
+ * Copyright (c) 1989, 1993, 1994
+ *      The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Guido van Rossum.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Function fnmatch() as specified in POSIX 1003.2-1992, section B.6.
+ * Compares a filename or pathname to a pattern.
+ */
+
+#include "fnmatch.h"
+
+#include <ctype.h>
+#include <stdio.h>
+#include <string.h>
+
+#define EOS		'\0'
+
+#define RANGE_MATCH		1
+#define RANGE_NOMATCH		0
+#define RANGE_ERROR		(-1)
+
+static int rangematch(const char *, char, int, char **);
+
+static int
+p_fnmatchx(const char *pattern, const char *string, int flags, size_t recurs)
+{
+		const char *stringstart;
+		char *newp;
+		char c, test;
+		int recurs_flags = flags & ~FNM_PERIOD;
+
+		if (recurs-- == 0)
+				return FNM_NORES;
+
+		for (stringstart = string;;)
+				switch (c = *pattern++) {
+				case EOS:
+						if ((flags & FNM_LEADING_DIR) && *string == '/')
+								return (0);
+						return (*string == EOS ? 0 : FNM_NOMATCH);
+				case '?':
+						if (*string == EOS)
+								return (FNM_NOMATCH);
+						if (*string == '/' && (flags & FNM_PATHNAME))
+								return (FNM_NOMATCH);
+						if (*string == '.' && (flags & FNM_PERIOD) &&
+							(string == stringstart ||
+							((flags & FNM_PATHNAME) && *(string - 1) == '/')))
+								return (FNM_NOMATCH);
+						++string;
+						break;
+				case '*':
+						c = *pattern;
+
+						/* Let '**' override PATHNAME match for this segment.
+						 * It will be restored if/when we recurse below.
+						 */
+						if (c == '*') {
+							c = *++pattern;
+							/* star-star-slash is at the end, match by default */
+							if (c == EOS)
+								return 0;
+							/* Double-star must be at end or between slashes */
+							if (c != '/')
+								return (FNM_NOMATCH);
+
+							c = *++pattern;
+							do {
+								int e = p_fnmatchx(pattern, string, recurs_flags, recurs);
+								if (e != FNM_NOMATCH)
+									return e;
+								string = strchr(string, '/');
+							} while (string++);
+
+							/* If we get here, we didn't find a match */
+							return FNM_NOMATCH;
+						}
+
+						if (*string == '.' && (flags & FNM_PERIOD) &&
+							(string == stringstart ||
+							((flags & FNM_PATHNAME) && *(string - 1) == '/')))
+								return (FNM_NOMATCH);
+
+						/* Optimize for pattern with * at end or before /. */
+						if (c == EOS) {
+								if (flags & FNM_PATHNAME)
+										return ((flags & FNM_LEADING_DIR) ||
+											strchr(string, '/') == NULL ?
+											0 : FNM_NOMATCH);
+								else
+										return (0);
+						} else if (c == '/' && (flags & FNM_PATHNAME)) {
+								if ((string = strchr(string, '/')) == NULL)
+										return (FNM_NOMATCH);
+								break;
+						}
+
+						/* General case, use recursion. */
+						while ((test = *string) != EOS) {
+								int e;
+
+								e = p_fnmatchx(pattern, string, recurs_flags, recurs);
+								if (e != FNM_NOMATCH)
+										return e;
+								if (test == '/' && (flags & FNM_PATHNAME))
+										break;
+								++string;
+						}
+						return (FNM_NOMATCH);
+				case '[':
+						if (*string == EOS)
+								return (FNM_NOMATCH);
+						if (*string == '/' && (flags & FNM_PATHNAME))
+								return (FNM_NOMATCH);
+						if (*string == '.' && (flags & FNM_PERIOD) &&
+							(string == stringstart ||
+							((flags & FNM_PATHNAME) && *(string - 1) == '/')))
+								return (FNM_NOMATCH);
+
+						switch (rangematch(pattern, *string, flags, &newp)) {
+						case RANGE_ERROR:
+								/* not a good range, treat as normal text */
+								goto normal;
+						case RANGE_MATCH:
+								pattern = newp;
+								break;
+						case RANGE_NOMATCH:
+								return (FNM_NOMATCH);
+						}
+						++string;
+						break;
+				case '\\':
+						if (!(flags & FNM_NOESCAPE)) {
+								if ((c = *pattern++) == EOS) {
+										c = '\\';
+										--pattern;
+								}
+						}
+						/* FALLTHROUGH */
+				default:
+				normal:
+						if (c != *string && !((flags & FNM_CASEFOLD) &&
+									(git__tolower((unsigned char)c) ==
+									git__tolower((unsigned char)*string))))
+								return (FNM_NOMATCH);
+						++string;
+						break;
+				}
+		/* NOTREACHED */
+}
+
+static int
+rangematch(const char *pattern, char test, int flags, char **newp)
+{
+		int negate, ok;
+		char c, c2;
+
+		/*
+			* A bracket expression starting with an unquoted circumflex
+			* character produces unspecified results (IEEE 1003.2-1992,
+			* 3.13.2). This implementation treats it like '!', for
+			* consistency with the regular expression syntax.
+			* J.T. Conklin (conklin@ngai.kaleida.com)
+			*/
+		if ((negate = (*pattern == '!' || *pattern == '^')) != 0)
+				++pattern;
+
+		if (flags & FNM_CASEFOLD)
+				test = (char)git__tolower((unsigned char)test);
+
+		/*
+			* A right bracket shall lose its special meaning and represent
+			* itself in a bracket expression if it occurs first in the list.
+			* -- POSIX.2 2.8.3.2
+			*/
+		ok = 0;
+		c = *pattern++;
+		do {
+				if (c == '\\' && !(flags & FNM_NOESCAPE))
+						c = *pattern++;
+				if (c == EOS)
+						return (RANGE_ERROR);
+				if (c == '/' && (flags & FNM_PATHNAME))
+						return (RANGE_NOMATCH);
+				if ((flags & FNM_CASEFOLD))
+						c = (char)git__tolower((unsigned char)c);
+				if (*pattern == '-'
+					&& (c2 = *(pattern+1)) != EOS && c2 != ']') {
+						pattern += 2;
+						if (c2 == '\\' && !(flags & FNM_NOESCAPE))
+								c2 = *pattern++;
+						if (c2 == EOS)
+								return (RANGE_ERROR);
+						if (flags & FNM_CASEFOLD)
+								c2 = (char)git__tolower((unsigned char)c2);
+						if (c <= test && test <= c2)
+								ok = 1;
+				} else if (c == test)
+						ok = 1;
+		} while ((c = *pattern++) != ']');
+
+		*newp = (char *)pattern;
+		return (ok == negate ? RANGE_NOMATCH : RANGE_MATCH);
+}
+
+int
+p_fnmatch(const char *pattern, const char *string, int flags)
+{
+		return p_fnmatchx(pattern, string, flags, 64);
+}
+

vendor/libgit2-sys/libgit2/src/fnmatch.h

diff --git a/vendor/libgit2-sys/libgit2/src/fnmatch.h b/vendor/libgit2-sys/libgit2/src/fnmatch.h
new file mode 100644
index 0000000..ddaae15
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/fnmatch.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+#ifndef INCLUDE_fnmatch_h__
+#define INCLUDE_fnmatch_h__
+
+#include "common.h"
+
+#define FNM_NOMATCH		1		/* Match failed. */
+#define FNM_NOSYS		2		/* Function not supported (unused). */
+#define	FNM_NORES		3		/* Out of resources */
+
+#define FNM_NOESCAPE	0x01		/* Disable backslash escaping. */
+#define FNM_PATHNAME	0x02		/* Slash must be matched by slash. */
+#define FNM_PERIOD		0x04		/* Period must be matched by period. */
+#define FNM_LEADING_DIR 0x08		/* Ignore /<tail> after Imatch. */
+#define FNM_CASEFOLD	0x10		/* Case insensitive search. */
+
+#define FNM_IGNORECASE	FNM_CASEFOLD
+#define FNM_FILE_NAME	FNM_PATHNAME
+
+extern int p_fnmatch(const char *pattern, const char *string, int flags);
+
+#endif

vendor/libgit2-sys/libgit2/src/global.c

diff --git a/vendor/libgit2-sys/libgit2/src/global.c b/vendor/libgit2-sys/libgit2/src/global.c
new file mode 100644
index 0000000..53e6609
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/global.c
@@ -0,0 +1,379 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "global.h"
+
+#include "hash.h"
+#include "sysdir.h"
+#include "filter.h"
+#include "merge_driver.h"
+#include "streams/curl.h"
+#include "streams/mbedtls.h"
+#include "streams/openssl.h"
+#include "thread-utils.h"
+#include "git2/global.h"
+#include "transports/ssh.h"
+
+#if defined(GIT_MSVC_CRTDBG)
+#include "win32/w32_stack.h"
+#include "win32/w32_crtdbg_stacktrace.h"
+#endif
+
+git_mutex git__mwindow_mutex;
+
+#define MAX_SHUTDOWN_CB 10
+
+static git_global_shutdown_fn git__shutdown_callbacks[MAX_SHUTDOWN_CB];
+static git_atomic git__n_shutdown_callbacks;
+static git_atomic git__n_inits;
+char *git__user_agent;
+char *git__ssl_ciphers;
+
+void git__on_shutdown(git_global_shutdown_fn callback)
+{
+	int count = git_atomic_inc(&git__n_shutdown_callbacks);
+	assert(count <= MAX_SHUTDOWN_CB && count > 0);
+	git__shutdown_callbacks[count - 1] = callback;
+}
+
+static void git__global_state_cleanup(git_global_st *st)
+{
+	if (!st)
+		return;
+
+	git__free(st->error_t.message);
+	st->error_t.message = NULL;
+}
+
+static int init_common(void)
+{
+	int ret;
+
+	/* Initialize the CRT debug allocator first, before our first malloc */
+#if defined(GIT_MSVC_CRTDBG)
+	git_win32__crtdbg_stacktrace_init();
+	git_win32__stack_init();
+#endif
+
+	/* Initialize any other subsystems that have global state */
+	if ((ret = git_hash_global_init()) == 0 &&
+		(ret = git_sysdir_global_init()) == 0 &&
+		(ret = git_filter_global_init()) == 0 &&
+		(ret = git_merge_driver_global_init()) == 0 &&
+		(ret = git_transport_ssh_global_init()) == 0 &&
+		(ret = git_openssl_stream_global_init()) == 0 &&
+		(ret = git_curl_stream_global_init()) == 0 &&
+		(ret = git_mbedtls_stream_global_init()) == 0)
+		ret = git_mwindow_global_init();
+
+	GIT_MEMORY_BARRIER;
+
+	return ret;
+}
+
+static void shutdown_common(void)
+{
+	int pos;
+
+	/* Shutdown subsystems that have registered */
+	for (pos = git_atomic_get(&git__n_shutdown_callbacks);
+		pos > 0;
+		pos = git_atomic_dec(&git__n_shutdown_callbacks)) {
+
+		git_global_shutdown_fn cb = git__swap(
+			git__shutdown_callbacks[pos - 1], NULL);
+
+		if (cb != NULL)
+			cb();
+	}
+
+	git__free(git__user_agent);
+	git__free(git__ssl_ciphers);
+}
+
+/**
+ * Handle the global state with TLS
+ *
+ * If libgit2 is built with GIT_THREADS enabled,
+ * the `git_libgit2_init()` function must be called
+ * before calling any other function of the library.
+ *
+ * This function allocates a TLS index (using pthreads
+ * or the native Win32 API) to store the global state
+ * on a per-thread basis.
+ *
+ * Any internal method that requires global state will
+ * then call `git__global_state()` which returns a pointer
+ * to the global state structure; this pointer is lazily
+ * allocated on each thread.
+ *
+ * Before shutting down the library, the
+ * `git_libgit2_shutdown` method must be called to free
+ * the previously reserved TLS index.
+ *
+ * If libgit2 is built without threading support, the
+ * `git__global_statestate()` call returns a pointer to a single,
+ * statically allocated global state. The `git_thread_`
+ * functions are not available in that case.
+ */
+
+/*
+ * `git_libgit2_init()` allows subsystems to perform global setup,
+ * which may take place in the global scope.  An explicit memory
+ * fence exists at the exit of `git_libgit2_init()`.  Without this,
+ * CPU cores are free to reorder cache invalidation of `_tls_init`
+ * before cache invalidation of the subsystems' newly written global
+ * state.
+ */
+#if defined(GIT_THREADS) && defined(GIT_WIN32)
+
+static DWORD _tls_index;
+static volatile LONG _mutex = 0;
+
+static int synchronized_threads_init(void)
+{
+	int error;
+
+	_tls_index = TlsAlloc();
+
+	git_threads_init();
+
+	if (git_mutex_init(&git__mwindow_mutex))
+		return -1;
+
+	error = init_common();
+
+	return error;
+}
+
+int git_libgit2_init(void)
+{
+	int ret;
+
+	/* Enter the lock */
+	while (InterlockedCompareExchange(&_mutex, 1, 0)) { Sleep(0); }
+
+	/* Only do work on a 0 -> 1 transition of the refcount */
+	if ((ret = git_atomic_inc(&git__n_inits)) == 1) {
+		if (synchronized_threads_init() < 0)
+			ret = -1;
+	}
+
+	/* Exit the lock */
+	InterlockedExchange(&_mutex, 0);
+
+	return ret;
+}
+
+int git_libgit2_shutdown(void)
+{
+	int ret;
+
+	/* Enter the lock */
+	while (InterlockedCompareExchange(&_mutex, 1, 0)) { Sleep(0); }
+
+	/* Only do work on a 1 -> 0 transition of the refcount */
+	if ((ret = git_atomic_dec(&git__n_inits)) == 0) {
+		shutdown_common();
+
+		git__free_tls_data();
+
+		TlsFree(_tls_index);
+		git_mutex_free(&git__mwindow_mutex);
+
+#if defined(GIT_MSVC_CRTDBG)
+		git_win32__crtdbg_stacktrace_cleanup();
+		git_win32__stack_cleanup();
+#endif
+	}
+
+	/* Exit the lock */
+	InterlockedExchange(&_mutex, 0);
+
+	return ret;
+}
+
+git_global_st *git__global_state(void)
+{
+	git_global_st *ptr;
+
+	assert(git_atomic_get(&git__n_inits) > 0);
+
+	if ((ptr = TlsGetValue(_tls_index)) != NULL)
+		return ptr;
+
+	ptr = git__calloc(1, sizeof(git_global_st));
+	if (!ptr)
+		return NULL;
+
+	git_buf_init(&ptr->error_buf, 0);
+
+	TlsSetValue(_tls_index, ptr);
+	return ptr;
+}
+
+/**
+ * Free the TLS data associated with this thread.
+ * This should only be used by the thread as it
+ * is exiting.
+ */
+void git__free_tls_data(void)
+{
+	void *ptr = TlsGetValue(_tls_index);
+	if (!ptr)
+		return;
+
+	git__global_state_cleanup(ptr);
+	git__free(ptr);
+	TlsSetValue(_tls_index, NULL);
+}
+
+BOOL WINAPI DllMain(HINSTANCE hInstDll, DWORD fdwReason, LPVOID lpvReserved)
+{
+	GIT_UNUSED(hInstDll);
+	GIT_UNUSED(lpvReserved);
+
+	/* This is how Windows lets us know our thread is being shut down */
+	if (fdwReason == DLL_THREAD_DETACH) {
+		git__free_tls_data();
+	}
+
+	/*
+	 * Windows pays attention to this during library loading. We don't do anything
+	 * so we trivially succeed.
+	 */
+	return TRUE;
+}
+
+#elif defined(GIT_THREADS) && defined(_POSIX_THREADS)
+
+static pthread_key_t _tls_key;
+static pthread_mutex_t _init_mutex = PTHREAD_MUTEX_INITIALIZER;
+static pthread_once_t _once_init = PTHREAD_ONCE_INIT;
+int init_error = 0;
+
+static void cb__free_status(void *st)
+{
+	git__global_state_cleanup(st);
+	git__free(st);
+}
+
+static void init_once(void)
+{
+	if ((init_error = git_mutex_init(&git__mwindow_mutex)) != 0)
+		return;
+
+	pthread_key_create(&_tls_key, &cb__free_status);
+
+	init_error = init_common();
+}
+
+int git_libgit2_init(void)
+{
+	int ret, err;
+
+	if ((err = pthread_mutex_lock(&_init_mutex)) != 0)
+		return err;
+
+	ret = git_atomic_inc(&git__n_inits);
+	err = pthread_once(&_once_init, init_once);
+	err |= pthread_mutex_unlock(&_init_mutex);
+
+	if (err || init_error)
+		return err | init_error;
+
+	return ret;
+}
+
+int git_libgit2_shutdown(void)
+{
+	void *ptr = NULL;
+	pthread_once_t new_once = PTHREAD_ONCE_INIT;
+	int error, ret;
+
+	if ((error = pthread_mutex_lock(&_init_mutex)) != 0)
+		return error;
+
+	if ((ret = git_atomic_dec(&git__n_inits)) != 0)
+		goto out;
+
+	/* Shut down any subsystems that have global state */
+	shutdown_common();
+
+	ptr = pthread_getspecific(_tls_key);
+	pthread_setspecific(_tls_key, NULL);
+
+	git__global_state_cleanup(ptr);
+	git__free(ptr);
+
+	pthread_key_delete(_tls_key);
+	git_mutex_free(&git__mwindow_mutex);
+	_once_init = new_once;
+
+out:
+	if ((error = pthread_mutex_unlock(&_init_mutex)) != 0)
+		return error;
+
+	return ret;
+}
+
+git_global_st *git__global_state(void)
+{
+	git_global_st *ptr;
+
+	assert(git_atomic_get(&git__n_inits) > 0);
+
+	if ((ptr = pthread_getspecific(_tls_key)) != NULL)
+		return ptr;
+
+	ptr = git__calloc(1, sizeof(git_global_st));
+	if (!ptr)
+		return NULL;
+
+	git_buf_init(&ptr->error_buf, 0);
+	pthread_setspecific(_tls_key, ptr);
+	return ptr;
+}
+
+#else
+
+static git_global_st __state;
+
+int git_libgit2_init(void)
+{
+	int ret;
+
+	/* Only init subsystems the first time */
+	if ((ret = git_atomic_inc(&git__n_inits)) != 1)
+		return ret;
+
+	if ((ret = init_common()) < 0)
+		return ret;
+
+	return 1;
+}
+
+int git_libgit2_shutdown(void)
+{
+	int ret;
+
+	/* Shut down any subsystems that have global state */
+	if ((ret = git_atomic_dec(&git__n_inits)) == 0) {
+		shutdown_common();
+		git__global_state_cleanup(&__state);
+		memset(&__state, 0, sizeof(__state));
+	}
+
+	return ret;
+}
+
+git_global_st *git__global_state(void)
+{
+	return &__state;
+}
+
+#endif /* GIT_THREADS */

vendor/libgit2-sys/libgit2/src/global.h

diff --git a/vendor/libgit2-sys/libgit2/src/global.h b/vendor/libgit2-sys/libgit2/src/global.h
new file mode 100644
index 0000000..3c0559c
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/global.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_global_h__
+#define INCLUDE_global_h__
+
+#include "common.h"
+
+#include "mwindow.h"
+#include "hash.h"
+
+typedef struct {
+	git_error *last_error;
+	git_error error_t;
+	git_buf error_buf;
+	char oid_fmt[GIT_OID_HEXSZ+1];
+
+	/* On Windows, this is the current child thread that was started by
+	 * `git_thread_create`.  This is used to set the thread's exit code
+	 * when terminated by `git_thread_exit`.  It is unused on POSIX.
+	 */
+	git_thread *current_thread;
+} git_global_st;
+
+git_global_st *git__global_state(void);
+
+extern git_mutex git__mwindow_mutex;
+
+#define GIT_GLOBAL (git__global_state())
+
+typedef void (*git_global_shutdown_fn)(void);
+
+extern void git__on_shutdown(git_global_shutdown_fn callback);
+
+extern void git__free_tls_data(void);
+
+extern const char *git_libgit2__user_agent(void);
+extern const char *git_libgit2__ssl_ciphers(void);
+
+#endif

vendor/libgit2-sys/libgit2/src/graph.c

diff --git a/vendor/libgit2-sys/libgit2/src/graph.c b/vendor/libgit2-sys/libgit2/src/graph.c
new file mode 100644
index 0000000..df82f0f
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/graph.c
@@ -0,0 +1,194 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "revwalk.h"
+#include "merge.h"
+#include "git2/graph.h"
+
+static int interesting(git_pqueue *list, git_commit_list *roots)
+{
+	unsigned int i;
+
+	for (i = 0; i < git_pqueue_size(list); i++) {
+		git_commit_list_node *commit = git_pqueue_get(list, i);
+		if ((commit->flags & STALE) == 0)
+			return 1;
+	}
+
+	while(roots) {
+		if ((roots->item->flags & STALE) == 0)
+			return 1;
+		roots = roots->next;
+	}
+
+	return 0;
+}
+
+static int mark_parents(git_revwalk *walk, git_commit_list_node *one,
+	git_commit_list_node *two)
+{
+	unsigned int i;
+	git_commit_list *roots = NULL;
+	git_pqueue list;
+
+	/* if the commit is repeated, we have a our merge base already */
+	if (one == two) {
+		one->flags |= PARENT1 | PARENT2 | RESULT;
+		return 0;
+	}
+
+	if (git_pqueue_init(&list, 0, 2, git_commit_list_time_cmp) < 0)
+		return -1;
+
+	if (git_commit_list_parse(walk, one) < 0)
+		goto on_error;
+	one->flags |= PARENT1;
+	if (git_pqueue_insert(&list, one) < 0)
+		goto on_error;
+
+	if (git_commit_list_parse(walk, two) < 0)
+		goto on_error;
+	two->flags |= PARENT2;
+	if (git_pqueue_insert(&list, two) < 0)
+		goto on_error;
+
+	/* as long as there are non-STALE commits */
+	while (interesting(&list, roots)) {
+		git_commit_list_node *commit = git_pqueue_pop(&list);
+		unsigned int flags;
+
+		if (commit == NULL)
+			break;
+
+		flags = commit->flags & (PARENT1 | PARENT2 | STALE);
+		if (flags == (PARENT1 | PARENT2)) {
+			if (!(commit->flags & RESULT))
+				commit->flags |= RESULT;
+			/* we mark the parents of a merge stale */
+			flags |= STALE;
+		}
+
+		for (i = 0; i < commit->out_degree; i++) {
+			git_commit_list_node *p = commit->parents[i];
+			if ((p->flags & flags) == flags)
+				continue;
+
+			if (git_commit_list_parse(walk, p) < 0)
+				goto on_error;
+
+			p->flags |= flags;
+			if (git_pqueue_insert(&list, p) < 0)
+				goto on_error;
+		}
+
+		/* Keep track of root commits, to make sure the path gets marked */
+		if (commit->out_degree == 0) {
+			if (git_commit_list_insert(commit, &roots) == NULL)
+				goto on_error;
+		}
+	}
+
+	git_commit_list_free(&roots);
+	git_pqueue_free(&list);
+	return 0;
+
+on_error:
+	git_commit_list_free(&roots);
+	git_pqueue_free(&list);
+	return -1;
+}
+
+
+static int ahead_behind(git_commit_list_node *one, git_commit_list_node *two,
+	size_t *ahead, size_t *behind)
+{
+	git_commit_list_node *commit;
+	git_pqueue pq;
+	int error = 0, i;
+	*ahead = 0;
+	*behind = 0;
+
+	if (git_pqueue_init(&pq, 0, 2, git_commit_list_time_cmp) < 0)
+		return -1;
+
+	if ((error = git_pqueue_insert(&pq, one)) < 0 ||
+		(error = git_pqueue_insert(&pq, two)) < 0)
+		goto done;
+
+	while ((commit = git_pqueue_pop(&pq)) != NULL) {
+		if (commit->flags & RESULT ||
+			(commit->flags & (PARENT1 | PARENT2)) == (PARENT1 | PARENT2))
+			continue;
+		else if (commit->flags & PARENT1)
+			(*ahead)++;
+		else if (commit->flags & PARENT2)
+			(*behind)++;
+
+		for (i = 0; i < commit->out_degree; i++) {
+			git_commit_list_node *p = commit->parents[i];
+			if ((error = git_pqueue_insert(&pq, p)) < 0)
+				goto done;
+		}
+		commit->flags |= RESULT;
+	}
+
+done:
+	git_pqueue_free(&pq);
+	return error;
+}
+
+int git_graph_ahead_behind(size_t *ahead, size_t *behind, git_repository *repo,
+	const git_oid *local, const git_oid *upstream)
+{
+	git_revwalk *walk;
+	git_commit_list_node *commit_u, *commit_l;
+
+	if (git_revwalk_new(&walk, repo) < 0)
+		return -1;
+
+	commit_u = git_revwalk__commit_lookup(walk, upstream);
+	if (commit_u == NULL)
+		goto on_error;
+
+	commit_l = git_revwalk__commit_lookup(walk, local);
+	if (commit_l == NULL)
+		goto on_error;
+
+	if (mark_parents(walk, commit_l, commit_u) < 0)
+		goto on_error;
+	if (ahead_behind(commit_l, commit_u, ahead, behind) < 0)
+		goto on_error;
+
+	git_revwalk_free(walk);
+
+	return 0;
+
+on_error:
+	git_revwalk_free(walk);
+	return -1;
+}
+
+int git_graph_descendant_of(git_repository *repo, const git_oid *commit, const git_oid *ancestor)
+{
+	git_oid merge_base;
+	int error;
+
+	if (git_oid_equal(commit, ancestor))
+		return 0;
+
+	error = git_merge_base(&merge_base, repo, commit, ancestor);
+	/* No merge-base found, it's not a descendant */
+	if (error == GIT_ENOTFOUND)
+		return 0;
+
+	if (error < 0)
+		return error;
+
+	return git_oid_equal(&merge_base, ancestor);
+}

vendor/libgit2-sys/libgit2/src/hash.c

diff --git a/vendor/libgit2-sys/libgit2/src/hash.c b/vendor/libgit2-sys/libgit2/src/hash.c
new file mode 100644
index 0000000..cc6676d
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/hash.c
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "hash.h"
+
+int git_hash_buf(git_oid *out, const void *data, size_t len)
+{
+	git_hash_ctx ctx;
+	int error = 0;
+
+	if (git_hash_ctx_init(&ctx) < 0)
+		return -1;
+
+	if ((error = git_hash_update(&ctx, data, len)) >= 0)
+		error = git_hash_final(out, &ctx);
+
+	git_hash_ctx_cleanup(&ctx);
+	
+	return error;
+}
+
+int git_hash_vec(git_oid *out, git_buf_vec *vec, size_t n)
+{
+	git_hash_ctx ctx;
+	size_t i;
+	int error = 0;
+
+	if (git_hash_ctx_init(&ctx) < 0)
+		return -1;
+
+	for (i = 0; i < n; i++) {
+		if ((error = git_hash_update(&ctx, vec[i].data, vec[i].len)) < 0)
+			goto done;
+	}
+
+	error = git_hash_final(out, &ctx);
+
+done:
+	git_hash_ctx_cleanup(&ctx);
+
+	return error;
+}

vendor/libgit2-sys/libgit2/src/hash.h

diff --git a/vendor/libgit2-sys/libgit2/src/hash.h b/vendor/libgit2-sys/libgit2/src/hash.h
new file mode 100644
index 0000000..93765ad
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/hash.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_hash_h__
+#define INCLUDE_hash_h__
+
+#include "common.h"
+
+#include "git2/oid.h"
+
+typedef struct git_hash_prov git_hash_prov;
+typedef struct git_hash_ctx git_hash_ctx;
+
+int git_hash_global_init(void);
+int git_hash_ctx_init(git_hash_ctx *ctx);
+void git_hash_ctx_cleanup(git_hash_ctx *ctx);
+
+#if defined(GIT_SHA1_COLLISIONDETECT)
+# include "hash/hash_collisiondetect.h"
+#elif defined(GIT_SHA1_COMMON_CRYPTO)
+# include "hash/hash_common_crypto.h"
+#elif defined(GIT_SHA1_OPENSSL)
+# include "hash/hash_openssl.h"
+#elif defined(GIT_SHA1_WIN32)
+# include "hash/hash_win32.h"
+#elif defined(GIT_SHA1_MBEDTLS)
+# include "hash/hash_mbedtls.h"
+#else
+# include "hash/hash_generic.h"
+#endif
+
+typedef struct {
+	void *data;
+	size_t len;
+} git_buf_vec;
+
+int git_hash_init(git_hash_ctx *c);
+int git_hash_update(git_hash_ctx *c, const void *data, size_t len);
+int git_hash_final(git_oid *out, git_hash_ctx *c);
+
+int git_hash_buf(git_oid *out, const void *data, size_t len);
+int git_hash_vec(git_oid *out, git_buf_vec *vec, size_t n);
+
+#endif

vendor/libgit2-sys/libgit2/src/hash/hash_collisiondetect.h

diff --git a/vendor/libgit2-sys/libgit2/src/hash/hash_collisiondetect.h b/vendor/libgit2-sys/libgit2/src/hash/hash_collisiondetect.h
new file mode 100644
index 0000000..4c5e3c3
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/hash/hash_collisiondetect.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_hash_hash_collisiondetect_h__
+#define INCLUDE_hash_hash_collisiondetect_h__
+
+#include "hash.h"
+#include "sha1dc/sha1.h"
+
+struct git_hash_ctx {
+	SHA1_CTX c;
+};
+
+#define git_hash_global_init() 0
+#define git_hash_ctx_init(ctx) git_hash_init(ctx)
+#define git_hash_ctx_cleanup(ctx)
+
+GIT_INLINE(int) git_hash_init(git_hash_ctx *ctx)
+{
+	assert(ctx);
+	SHA1DCInit(&ctx->c);
+	return 0;
+}
+
+GIT_INLINE(int) git_hash_update(git_hash_ctx *ctx, const void *data, size_t len)
+{
+	assert(ctx);
+	SHA1DCUpdate(&ctx->c, data, len);
+	return 0;
+}
+
+GIT_INLINE(int) git_hash_final(git_oid *out, git_hash_ctx *ctx)
+{
+	assert(ctx);
+	if (SHA1DCFinal(out->id, &ctx->c)) {
+		giterr_set(GITERR_SHA1, "SHA1 collision attack detected");
+		return -1;
+	}
+
+	return 0;
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/hash/hash_common_crypto.h

diff --git a/vendor/libgit2-sys/libgit2/src/hash/hash_common_crypto.h b/vendor/libgit2-sys/libgit2/src/hash/hash_common_crypto.h
new file mode 100644
index 0000000..5c3887d
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/hash/hash_common_crypto.h
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_hash_hash_common_crypto_h__
+#define INCLUDE_hash_hash_common_crypto_h__
+
+#include "hash.h"
+
+#include <CommonCrypto/CommonDigest.h>
+
+struct git_hash_ctx {
+	CC_SHA1_CTX c;
+};
+
+#define CC_LONG_MAX ((CC_LONG)-1)
+
+#define git_hash_global_init() 0
+#define git_hash_ctx_init(ctx) git_hash_init(ctx)
+#define git_hash_ctx_cleanup(ctx)
+
+GIT_INLINE(int) git_hash_init(git_hash_ctx *ctx)
+{
+	assert(ctx);
+	CC_SHA1_Init(&ctx->c);
+	return 0;
+}
+
+GIT_INLINE(int) git_hash_update(git_hash_ctx *ctx, const void *_data, size_t len)
+{
+	const unsigned char *data = _data;
+
+	assert(ctx);
+
+	while (len > 0) {
+		CC_LONG chunk = (len > CC_LONG_MAX) ? CC_LONG_MAX : (CC_LONG)len;
+
+		CC_SHA1_Update(&ctx->c, data, chunk);
+
+		data += chunk;
+		len -= chunk;
+	}
+
+	return 0;
+}
+
+GIT_INLINE(int) git_hash_final(git_oid *out, git_hash_ctx *ctx)
+{
+	assert(ctx);
+	CC_SHA1_Final(out->id, &ctx->c);
+	return 0;
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/hash/hash_generic.c

diff --git a/vendor/libgit2-sys/libgit2/src/hash/hash_generic.c b/vendor/libgit2-sys/libgit2/src/hash/hash_generic.c
new file mode 100644
index 0000000..7b33b61
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/hash/hash_generic.c
@@ -0,0 +1,288 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "hash_generic.h"
+
+#include "hash.h"
+
+#if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
+
+/*
+ * Force usage of rol or ror by selecting the one with the smaller constant.
+ * It _can_ generate slightly smaller code (a constant of 1 is special), but
+ * perhaps more importantly it's possibly faster on any uarch that does a
+ * rotate with a loop.
+ */
+
+#define SHA_ASM(op, x, n) (__extension__ ({ unsigned int __res; __asm__(op " %1,%0":"=r" (__res):"i" (n), "0" (x)); __res; }))
+#define SHA_ROL(x,n)	SHA_ASM("rol", x, n)
+#define SHA_ROR(x,n)	SHA_ASM("ror", x, n)
+
+#else
+
+#define SHA_ROT(X,l,r)	(((X) << (l)) | ((X) >> (r)))
+#define SHA_ROL(X,n)	SHA_ROT(X,n,32-(n))
+#define SHA_ROR(X,n)	SHA_ROT(X,32-(n),n)
+
+#endif
+
+/*
+ * If you have 32 registers or more, the compiler can (and should)
+ * try to change the array[] accesses into registers. However, on
+ * machines with less than ~25 registers, that won't really work,
+ * and at least gcc will make an unholy mess of it.
+ *
+ * So to avoid that mess which just slows things down, we force
+ * the stores to memory to actually happen (we might be better off
+ * with a 'W(t)=(val);asm("":"+m" (W(t))' there instead, as
+ * suggested by Artur Skawina - that will also make gcc unable to
+ * try to do the silly "optimize away loads" part because it won't
+ * see what the value will be).
+ *
+ * Ben Herrenschmidt reports that on PPC, the C version comes close
+ * to the optimized asm with this (ie on PPC you don't want that
+ * 'volatile', since there are lots of registers).
+ *
+ * On ARM we get the best code generation by forcing a full memory barrier
+ * between each SHA_ROUND, otherwise gcc happily get wild with spilling and
+ * the stack frame size simply explode and performance goes down the drain.
+ */
+
+#if defined(__i386__) || defined(__x86_64__)
+ #define setW(x, val) (*(volatile unsigned int *)&W(x) = (val))
+#elif defined(__GNUC__) && defined(__arm__)
+ #define setW(x, val) do { W(x) = (val); __asm__("":::"memory"); } while (0)
+#else
+ #define setW(x, val) (W(x) = (val))
+#endif
+
+/*
+ * Performance might be improved if the CPU architecture is OK with
+ * unaligned 32-bit loads and a fast ntohl() is available.
+ * Otherwise fall back to byte loads and shifts which is portable,
+ * and is faster on architectures with memory alignment issues.
+ */
+
+#if defined(__i386__) || defined(__x86_64__) || \
+	defined(_M_IX86) || defined(_M_X64) || \
+	defined(__ppc__) || defined(__ppc64__) || \
+	defined(__powerpc__) || defined(__powerpc64__) || \
+	defined(__s390__) || defined(__s390x__)
+
+#define get_be32(p)	ntohl(*(const unsigned int *)(p))
+#define put_be32(p, v)	do { *(unsigned int *)(p) = htonl(v); } while (0)
+
+#else
+
+#define get_be32(p)	( \
+	(*((const unsigned char *)(p) + 0) << 24) | \
+	(*((const unsigned char *)(p) + 1) << 16) | \
+	(*((const unsigned char *)(p) + 2) << 8) | \
+	(*((const unsigned char *)(p) + 3) << 0) )
+#define put_be32(p, v)	do { \
+	unsigned int __v = (v); \
+	*((unsigned char *)(p) + 0) = __v >> 24; \
+	*((unsigned char *)(p) + 1) = __v >> 16; \
+	*((unsigned char *)(p) + 2) = __v >> 8; \
+	*((unsigned char *)(p) + 3) = __v >> 0; } while (0)
+
+#endif
+
+/* This "rolls" over the 512-bit array */
+#define W(x) (array[(x)&15])
+
+/*
+ * Where do we get the source from? The first 16 iterations get it from
+ * the input data, the next mix it from the 512-bit array.
+ */
+#define SHA_SRC(t) get_be32(data + t)
+#define SHA_MIX(t) SHA_ROL(W(t+13) ^ W(t+8) ^ W(t+2) ^ W(t), 1)
+
+#define SHA_ROUND(t, input, fn, constant, A, B, C, D, E) do { \
+	unsigned int TEMP = input(t); setW(t, TEMP); \
+	E += TEMP + SHA_ROL(A,5) + (fn) + (constant); \
+	B = SHA_ROR(B, 2); } while (0)
+
+#define T_0_15(t, A, B, C, D, E) SHA_ROUND(t, SHA_SRC, (((C^D)&B)^D) , 0x5a827999, A, B, C, D, E )
+#define T_16_19(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (((C^D)&B)^D) , 0x5a827999, A, B, C, D, E )
+#define T_20_39(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0x6ed9eba1, A, B, C, D, E )
+#define T_40_59(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, ((B&C)+(D&(B^C))) , 0x8f1bbcdc, A, B, C, D, E )
+#define T_60_79(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0xca62c1d6, A, B, C, D, E )
+
+static void hash__block(git_hash_ctx *ctx, const unsigned int *data)
+{
+	unsigned int A,B,C,D,E;
+	unsigned int array[16];
+
+	A = ctx->H[0];
+	B = ctx->H[1];
+	C = ctx->H[2];
+	D = ctx->H[3];
+	E = ctx->H[4];
+
+	/* Round 1 - iterations 0-16 take their input from 'data' */
+	T_0_15( 0, A, B, C, D, E);
+	T_0_15( 1, E, A, B, C, D);
+	T_0_15( 2, D, E, A, B, C);
+	T_0_15( 3, C, D, E, A, B);
+	T_0_15( 4, B, C, D, E, A);
+	T_0_15( 5, A, B, C, D, E);
+	T_0_15( 6, E, A, B, C, D);
+	T_0_15( 7, D, E, A, B, C);
+	T_0_15( 8, C, D, E, A, B);
+	T_0_15( 9, B, C, D, E, A);
+	T_0_15(10, A, B, C, D, E);
+	T_0_15(11, E, A, B, C, D);
+	T_0_15(12, D, E, A, B, C);
+	T_0_15(13, C, D, E, A, B);
+	T_0_15(14, B, C, D, E, A);
+	T_0_15(15, A, B, C, D, E);
+
+	/* Round 1 - tail. Input from 512-bit mixing array */
+	T_16_19(16, E, A, B, C, D);
+	T_16_19(17, D, E, A, B, C);
+	T_16_19(18, C, D, E, A, B);
+	T_16_19(19, B, C, D, E, A);
+
+	/* Round 2 */
+	T_20_39(20, A, B, C, D, E);
+	T_20_39(21, E, A, B, C, D);
+	T_20_39(22, D, E, A, B, C);
+	T_20_39(23, C, D, E, A, B);
+	T_20_39(24, B, C, D, E, A);
+	T_20_39(25, A, B, C, D, E);
+	T_20_39(26, E, A, B, C, D);
+	T_20_39(27, D, E, A, B, C);
+	T_20_39(28, C, D, E, A, B);
+	T_20_39(29, B, C, D, E, A);
+	T_20_39(30, A, B, C, D, E);
+	T_20_39(31, E, A, B, C, D);
+	T_20_39(32, D, E, A, B, C);
+	T_20_39(33, C, D, E, A, B);
+	T_20_39(34, B, C, D, E, A);
+	T_20_39(35, A, B, C, D, E);
+	T_20_39(36, E, A, B, C, D);
+	T_20_39(37, D, E, A, B, C);
+	T_20_39(38, C, D, E, A, B);
+	T_20_39(39, B, C, D, E, A);
+
+	/* Round 3 */
+	T_40_59(40, A, B, C, D, E);
+	T_40_59(41, E, A, B, C, D);
+	T_40_59(42, D, E, A, B, C);
+	T_40_59(43, C, D, E, A, B);
+	T_40_59(44, B, C, D, E, A);
+	T_40_59(45, A, B, C, D, E);
+	T_40_59(46, E, A, B, C, D);
+	T_40_59(47, D, E, A, B, C);
+	T_40_59(48, C, D, E, A, B);
+	T_40_59(49, B, C, D, E, A);
+	T_40_59(50, A, B, C, D, E);
+	T_40_59(51, E, A, B, C, D);
+	T_40_59(52, D, E, A, B, C);
+	T_40_59(53, C, D, E, A, B);
+	T_40_59(54, B, C, D, E, A);
+	T_40_59(55, A, B, C, D, E);
+	T_40_59(56, E, A, B, C, D);
+	T_40_59(57, D, E, A, B, C);
+	T_40_59(58, C, D, E, A, B);
+	T_40_59(59, B, C, D, E, A);
+
+	/* Round 4 */
+	T_60_79(60, A, B, C, D, E);
+	T_60_79(61, E, A, B, C, D);
+	T_60_79(62, D, E, A, B, C);
+	T_60_79(63, C, D, E, A, B);
+	T_60_79(64, B, C, D, E, A);
+	T_60_79(65, A, B, C, D, E);
+	T_60_79(66, E, A, B, C, D);
+	T_60_79(67, D, E, A, B, C);
+	T_60_79(68, C, D, E, A, B);
+	T_60_79(69, B, C, D, E, A);
+	T_60_79(70, A, B, C, D, E);
+	T_60_79(71, E, A, B, C, D);
+	T_60_79(72, D, E, A, B, C);
+	T_60_79(73, C, D, E, A, B);
+	T_60_79(74, B, C, D, E, A);
+	T_60_79(75, A, B, C, D, E);
+	T_60_79(76, E, A, B, C, D);
+	T_60_79(77, D, E, A, B, C);
+	T_60_79(78, C, D, E, A, B);
+	T_60_79(79, B, C, D, E, A);
+
+	ctx->H[0] += A;
+	ctx->H[1] += B;
+	ctx->H[2] += C;
+	ctx->H[3] += D;
+	ctx->H[4] += E;
+}
+
+int git_hash_init(git_hash_ctx *ctx)
+{
+	ctx->size = 0;
+
+	/* Initialize H with the magic constants (see FIPS180 for constants) */
+	ctx->H[0] = 0x67452301;
+	ctx->H[1] = 0xefcdab89;
+	ctx->H[2] = 0x98badcfe;
+	ctx->H[3] = 0x10325476;
+	ctx->H[4] = 0xc3d2e1f0;
+
+	return 0;
+}
+
+int git_hash_update(git_hash_ctx *ctx, const void *data, size_t len)
+{
+	unsigned int lenW = ctx->size & 63;
+
+	ctx->size += len;
+
+	/* Read the data into W and process blocks as they get full */
+	if (lenW) {
+		unsigned int left = 64 - lenW;
+		if (len < left)
+			left = (unsigned int)len;
+		memcpy(lenW + (char *)ctx->W, data, left);
+		lenW = (lenW + left) & 63;
+		len -= left;
+		data = ((const char *)data + left);
+		if (lenW)
+			return 0;
+		hash__block(ctx, ctx->W);
+	}
+	while (len >= 64) {
+		hash__block(ctx, data);
+		data = ((const char *)data + 64);
+		len -= 64;
+	}
+	if (len)
+		memcpy(ctx->W, data, len);
+
+	return 0;
+}
+
+int git_hash_final(git_oid *out, git_hash_ctx *ctx)
+{
+	static const unsigned char pad[64] = { 0x80 };
+	unsigned int padlen[2];
+	int i;
+
+	/* Pad with a binary 1 (ie 0x80), then zeroes, then length */
+	padlen[0] = htonl((uint32_t)(ctx->size >> 29));
+	padlen[1] = htonl((uint32_t)(ctx->size << 3));
+
+	i = ctx->size & 63;
+	git_hash_update(ctx, pad, 1+ (63 & (55 - i)));
+	git_hash_update(ctx, padlen, 8);
+
+	/* Output hash */
+	for (i = 0; i < 5; i++)
+		put_be32(out->id + i*4, ctx->H[i]);
+
+	return 0;
+}
+

vendor/libgit2-sys/libgit2/src/hash/hash_generic.h

diff --git a/vendor/libgit2-sys/libgit2/src/hash/hash_generic.h b/vendor/libgit2-sys/libgit2/src/hash/hash_generic.h
new file mode 100644
index 0000000..21a0428
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/hash/hash_generic.h
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_hash_hash_generic_h__
+#define INCLUDE_hash_hash_generic_h__
+
+#include "common.h"
+
+#include "hash.h"
+
+struct git_hash_ctx {
+	unsigned long long size;
+	unsigned int H[5];
+	unsigned int W[16];
+};
+
+#define git_hash_global_init() 0
+#define git_hash_ctx_init(ctx) git_hash_init(ctx)
+#define git_hash_ctx_cleanup(ctx)
+
+#endif

vendor/libgit2-sys/libgit2/src/hash/hash_mbedtls.c

diff --git a/vendor/libgit2-sys/libgit2/src/hash/hash_mbedtls.c b/vendor/libgit2-sys/libgit2/src/hash/hash_mbedtls.c
new file mode 100644
index 0000000..a19d763
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/hash/hash_mbedtls.c
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+#include "hash.h"
+#include "hash/hash_mbedtls.h"
+
+void git_hash_ctx_cleanup(git_hash_ctx *ctx)
+{
+    assert(ctx);
+    mbedtls_sha1_free(&ctx->c);
+}
+
+int git_hash_init(git_hash_ctx *ctx)
+{
+    assert(ctx);
+    mbedtls_sha1_init(&ctx->c);
+    mbedtls_sha1_starts(&ctx->c);
+    return 0;
+}
+
+int git_hash_update(git_hash_ctx *ctx, const void *data, size_t len)
+{
+    assert(ctx);
+    mbedtls_sha1_update(&ctx->c, data, len);
+    return 0;
+}
+
+int git_hash_final(git_oid *out, git_hash_ctx *ctx)
+{
+    assert(ctx);
+    mbedtls_sha1_finish(&ctx->c, out->id);
+    return 0;
+}

vendor/libgit2-sys/libgit2/src/hash/hash_mbedtls.h

diff --git a/vendor/libgit2-sys/libgit2/src/hash/hash_mbedtls.h b/vendor/libgit2-sys/libgit2/src/hash/hash_mbedtls.h
new file mode 100644
index 0000000..24196c5b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/hash/hash_mbedtls.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_hash_mbedtld_h__
+#define INCLUDE_hash_mbedtld_h__
+
+#include <mbedtls/sha1.h>
+
+struct git_hash_ctx {
+    mbedtls_sha1_context c;
+};
+
+#define git_hash_global_init() 0
+#define git_hash_ctx_init(ctx) git_hash_init(ctx)
+
+#endif /* INCLUDE_hash_mbedtld_h__ */

vendor/libgit2-sys/libgit2/src/hash/hash_openssl.h

diff --git a/vendor/libgit2-sys/libgit2/src/hash/hash_openssl.h b/vendor/libgit2-sys/libgit2/src/hash/hash_openssl.h
new file mode 100644
index 0000000..eb2dcb0
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/hash/hash_openssl.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_hash_hash_openssl_h__
+#define INCLUDE_hash_hash_openssl_h__
+
+#include "hash.h"
+
+#include <openssl/sha.h>
+
+struct git_hash_ctx {
+	SHA_CTX c;
+};
+
+#define git_hash_global_init() 0
+#define git_hash_ctx_init(ctx) git_hash_init(ctx)
+#define git_hash_ctx_cleanup(ctx)
+
+GIT_INLINE(int) git_hash_init(git_hash_ctx *ctx)
+{
+	assert(ctx);
+
+	if (SHA1_Init(&ctx->c) != 1) {
+		giterr_set(GITERR_SHA1, "hash_openssl: failed to initialize hash context");
+		return -1;
+	}
+
+	return 0;
+}
+
+GIT_INLINE(int) git_hash_update(git_hash_ctx *ctx, const void *data, size_t len)
+{
+	assert(ctx);
+
+	if (SHA1_Update(&ctx->c, data, len) != 1) {
+		giterr_set(GITERR_SHA1, "hash_openssl: failed to update hash");
+		return -1;
+	}
+
+	return 0;
+}
+
+GIT_INLINE(int) git_hash_final(git_oid *out, git_hash_ctx *ctx)
+{
+	assert(ctx);
+
+	if (SHA1_Final(out->id, &ctx->c) != 1) {
+		giterr_set(GITERR_SHA1, "hash_openssl: failed to finalize hash");
+		return -1;
+	}
+
+	return 0;
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/hash/hash_win32.c

diff --git a/vendor/libgit2-sys/libgit2/src/hash/hash_win32.c b/vendor/libgit2-sys/libgit2/src/hash/hash_win32.c
new file mode 100644
index 0000000..779802c
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/hash/hash_win32.c
@@ -0,0 +1,319 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "hash_win32.h"
+
+#include "global.h"
+#include "hash.h"
+
+#include <wincrypt.h>
+#include <strsafe.h>
+
+static struct git_hash_prov hash_prov = {0};
+
+/* Hash initialization */
+
+/* Initialize CNG, if available */
+GIT_INLINE(int) hash_cng_prov_init(void)
+{
+	char dll_path[MAX_PATH];
+	DWORD dll_path_len, size_len;
+
+	/* Only use CNG on Windows 2008 / Vista SP1  or better (Windows 6.0 SP1) */
+	if (!git_has_win32_version(6, 0, 1)) {
+		giterr_set(GITERR_SHA1, "CryptoNG is not supported on this platform");
+		return -1;
+	}
+
+	/* Load bcrypt.dll explicitly from the system directory */
+	if ((dll_path_len = GetSystemDirectory(dll_path, MAX_PATH)) == 0 ||
+		dll_path_len > MAX_PATH ||
+		StringCchCat(dll_path, MAX_PATH, "\\") < 0 ||
+		StringCchCat(dll_path, MAX_PATH, GIT_HASH_CNG_DLL_NAME) < 0 ||
+		(hash_prov.prov.cng.dll = LoadLibrary(dll_path)) == NULL) {
+		giterr_set(GITERR_SHA1, "CryptoNG library could not be loaded");
+		return -1;
+	}
+
+	/* Load the function addresses */
+	if ((hash_prov.prov.cng.open_algorithm_provider = (hash_win32_cng_open_algorithm_provider_fn)GetProcAddress(hash_prov.prov.cng.dll, "BCryptOpenAlgorithmProvider")) == NULL ||
+		(hash_prov.prov.cng.get_property = (hash_win32_cng_get_property_fn)GetProcAddress(hash_prov.prov.cng.dll, "BCryptGetProperty")) == NULL ||
+		(hash_prov.prov.cng.create_hash = (hash_win32_cng_create_hash_fn)GetProcAddress(hash_prov.prov.cng.dll, "BCryptCreateHash")) == NULL ||
+		(hash_prov.prov.cng.finish_hash = (hash_win32_cng_finish_hash_fn)GetProcAddress(hash_prov.prov.cng.dll, "BCryptFinishHash")) == NULL ||
+		(hash_prov.prov.cng.hash_data = (hash_win32_cng_hash_data_fn)GetProcAddress(hash_prov.prov.cng.dll, "BCryptHashData")) == NULL ||
+		(hash_prov.prov.cng.destroy_hash = (hash_win32_cng_destroy_hash_fn)GetProcAddress(hash_prov.prov.cng.dll, "BCryptDestroyHash")) == NULL ||
+		(hash_prov.prov.cng.close_algorithm_provider = (hash_win32_cng_close_algorithm_provider_fn)GetProcAddress(hash_prov.prov.cng.dll, "BCryptCloseAlgorithmProvider")) == NULL) {
+		FreeLibrary(hash_prov.prov.cng.dll);
+
+		giterr_set(GITERR_OS, "CryptoNG functions could not be loaded");
+		return -1;
+	}
+
+	/* Load the SHA1 algorithm */
+	if (hash_prov.prov.cng.open_algorithm_provider(&hash_prov.prov.cng.handle, GIT_HASH_CNG_HASH_TYPE, NULL, GIT_HASH_CNG_HASH_REUSABLE) < 0) {
+		FreeLibrary(hash_prov.prov.cng.dll);
+
+		giterr_set(GITERR_OS, "algorithm provider could not be initialized");
+		return -1;
+	}
+
+	/* Get storage space for the hash object */
+	if (hash_prov.prov.cng.get_property(hash_prov.prov.cng.handle, GIT_HASH_CNG_HASH_OBJECT_LEN, (PBYTE)&hash_prov.prov.cng.hash_object_size, sizeof(DWORD), &size_len, 0) < 0) {
+		hash_prov.prov.cng.close_algorithm_provider(hash_prov.prov.cng.handle, 0);
+		FreeLibrary(hash_prov.prov.cng.dll);
+
+		giterr_set(GITERR_OS, "algorithm handle could not be found");
+		return -1;
+	}
+
+	hash_prov.type = CNG;
+	return 0;
+}
+
+GIT_INLINE(void) hash_cng_prov_shutdown(void)
+{
+	hash_prov.prov.cng.close_algorithm_provider(hash_prov.prov.cng.handle, 0);
+	FreeLibrary(hash_prov.prov.cng.dll);
+
+	hash_prov.type = INVALID;
+}
+
+/* Initialize CryptoAPI */
+GIT_INLINE(int) hash_cryptoapi_prov_init()
+{
+	if (!CryptAcquireContext(&hash_prov.prov.cryptoapi.handle, NULL, 0, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT)) {
+		giterr_set(GITERR_OS, "legacy hash context could not be started");
+		return -1;
+	}
+
+	hash_prov.type = CRYPTOAPI;
+	return 0;
+}
+
+GIT_INLINE(void) hash_cryptoapi_prov_shutdown(void)
+{
+	CryptReleaseContext(hash_prov.prov.cryptoapi.handle, 0);
+
+	hash_prov.type = INVALID;
+}
+
+static void git_hash_global_shutdown(void)
+{
+	if (hash_prov.type == CNG)
+		hash_cng_prov_shutdown();
+	else if(hash_prov.type == CRYPTOAPI)
+		hash_cryptoapi_prov_shutdown();
+}
+
+int git_hash_global_init(void)
+{
+	int error = 0;
+
+	if (hash_prov.type != INVALID)
+		return 0;
+
+	if ((error = hash_cng_prov_init()) < 0)
+		error = hash_cryptoapi_prov_init();
+
+	git__on_shutdown(git_hash_global_shutdown);
+
+	return error;
+}
+
+/* CryptoAPI: available in Windows XP and newer */
+
+GIT_INLINE(int) hash_ctx_cryptoapi_init(git_hash_ctx *ctx)
+{
+	ctx->type = CRYPTOAPI;
+	ctx->prov = &hash_prov;
+
+	return git_hash_init(ctx);
+}
+
+GIT_INLINE(int) hash_cryptoapi_init(git_hash_ctx *ctx)
+{
+	if (ctx->ctx.cryptoapi.valid)
+		CryptDestroyHash(ctx->ctx.cryptoapi.hash_handle);
+
+	if (!CryptCreateHash(ctx->prov->prov.cryptoapi.handle, CALG_SHA1, 0, 0, &ctx->ctx.cryptoapi.hash_handle)) {
+		ctx->ctx.cryptoapi.valid = 0;
+		giterr_set(GITERR_OS, "legacy hash implementation could not be created");
+		return -1;
+	}
+
+	ctx->ctx.cryptoapi.valid = 1;
+	return 0;
+}
+
+GIT_INLINE(int) hash_cryptoapi_update(git_hash_ctx *ctx, const void *_data, size_t len)
+{
+	const BYTE *data = (BYTE *)_data;
+
+	assert(ctx->ctx.cryptoapi.valid);
+
+	while (len > 0) {
+		DWORD chunk = (len > MAXDWORD) ? MAXDWORD : (DWORD)len;
+
+		if (!CryptHashData(ctx->ctx.cryptoapi.hash_handle, data, chunk, 0)) {
+			giterr_set(GITERR_OS, "legacy hash data could not be updated");
+			return -1;
+		}
+
+		data += chunk;
+		len -= chunk;
+	}
+
+	return 0;
+}
+
+GIT_INLINE(int) hash_cryptoapi_final(git_oid *out, git_hash_ctx *ctx)
+{
+	DWORD len = 20;
+	int error = 0;
+
+	assert(ctx->ctx.cryptoapi.valid);
+
+	if (!CryptGetHashParam(ctx->ctx.cryptoapi.hash_handle, HP_HASHVAL, out->id, &len, 0)) {
+		giterr_set(GITERR_OS, "legacy hash data could not be finished");
+		error = -1;
+	}
+
+	CryptDestroyHash(ctx->ctx.cryptoapi.hash_handle);
+	ctx->ctx.cryptoapi.valid = 0;
+
+	return error;
+}
+
+GIT_INLINE(void) hash_ctx_cryptoapi_cleanup(git_hash_ctx *ctx)
+{
+	if (ctx->ctx.cryptoapi.valid)
+		CryptDestroyHash(ctx->ctx.cryptoapi.hash_handle);
+}
+
+/* CNG: Available in Windows Server 2008 and newer */
+
+GIT_INLINE(int) hash_ctx_cng_init(git_hash_ctx *ctx)
+{
+	if ((ctx->ctx.cng.hash_object = git__malloc(hash_prov.prov.cng.hash_object_size)) == NULL)
+		return -1;
+
+	if (hash_prov.prov.cng.create_hash(hash_prov.prov.cng.handle, &ctx->ctx.cng.hash_handle, ctx->ctx.cng.hash_object, hash_prov.prov.cng.hash_object_size, NULL, 0, 0) < 0) {
+		git__free(ctx->ctx.cng.hash_object);
+
+		giterr_set(GITERR_OS, "hash implementation could not be created");
+		return -1;
+	}
+
+	ctx->type = CNG;
+	ctx->prov = &hash_prov;
+
+	return 0;
+}
+
+GIT_INLINE(int) hash_cng_init(git_hash_ctx *ctx)
+{
+	BYTE hash[GIT_OID_RAWSZ];
+
+	if (!ctx->ctx.cng.updated)
+		return 0;
+
+	/* CNG needs to be finished to restart */
+	if (ctx->prov->prov.cng.finish_hash(ctx->ctx.cng.hash_handle, hash, GIT_OID_RAWSZ, 0) < 0) {
+		giterr_set(GITERR_OS, "hash implementation could not be finished");
+		return -1;
+	}
+
+	ctx->ctx.cng.updated = 0;
+
+	return 0;
+}
+
+GIT_INLINE(int) hash_cng_update(git_hash_ctx *ctx, const void *_data, size_t len)
+{
+	PBYTE data = (PBYTE)_data;
+
+	while (len > 0) {
+		ULONG chunk = (len > ULONG_MAX) ? ULONG_MAX : (ULONG)len;
+
+		if (ctx->prov->prov.cng.hash_data(ctx->ctx.cng.hash_handle, data, chunk, 0) < 0) {
+			giterr_set(GITERR_OS, "hash could not be updated");
+			return -1;
+		}
+
+		data += chunk;
+		len -= chunk;
+	}
+
+	return 0;
+}
+
+GIT_INLINE(int) hash_cng_final(git_oid *out, git_hash_ctx *ctx)
+{
+	if (ctx->prov->prov.cng.finish_hash(ctx->ctx.cng.hash_handle, out->id, GIT_OID_RAWSZ, 0) < 0) {
+		giterr_set(GITERR_OS, "hash could not be finished");
+		return -1;
+	}
+
+	ctx->ctx.cng.updated = 0;
+
+	return 0;
+}
+
+GIT_INLINE(void) hash_ctx_cng_cleanup(git_hash_ctx *ctx)
+{
+	ctx->prov->prov.cng.destroy_hash(ctx->ctx.cng.hash_handle);
+	git__free(ctx->ctx.cng.hash_object);
+}
+
+/* Indirection between CryptoAPI and CNG */
+
+int git_hash_ctx_init(git_hash_ctx *ctx)
+{
+	int error = 0;
+
+	assert(ctx);
+
+	/*
+	 * When compiled with GIT_THREADS, the global hash_prov data is
+	 * initialized with git_libgit2_init.  Otherwise, it must be initialized
+	 * at first use.
+	 */
+	if (hash_prov.type == INVALID && (error = git_hash_global_init()) < 0)
+		return error;
+
+	memset(ctx, 0x0, sizeof(git_hash_ctx));
+
+	return (hash_prov.type == CNG) ? hash_ctx_cng_init(ctx) : hash_ctx_cryptoapi_init(ctx);
+}
+
+int git_hash_init(git_hash_ctx *ctx)
+{
+	assert(ctx && ctx->type);
+	return (ctx->type == CNG) ? hash_cng_init(ctx) : hash_cryptoapi_init(ctx);
+}
+
+int git_hash_update(git_hash_ctx *ctx, const void *data, size_t len)
+{
+	assert(ctx && ctx->type);
+	return (ctx->type == CNG) ? hash_cng_update(ctx, data, len) : hash_cryptoapi_update(ctx, data, len);
+}
+
+int git_hash_final(git_oid *out, git_hash_ctx *ctx)
+{
+	assert(ctx && ctx->type);
+	return (ctx->type == CNG) ? hash_cng_final(out, ctx) : hash_cryptoapi_final(out, ctx);
+}
+
+void git_hash_ctx_cleanup(git_hash_ctx *ctx)
+{
+	assert(ctx);
+
+	if (ctx->type == CNG)
+		hash_ctx_cng_cleanup(ctx);
+	else if(ctx->type == CRYPTOAPI)
+		hash_ctx_cryptoapi_cleanup(ctx);
+}

vendor/libgit2-sys/libgit2/src/hash/hash_win32.h

diff --git a/vendor/libgit2-sys/libgit2/src/hash/hash_win32.h b/vendor/libgit2-sys/libgit2/src/hash/hash_win32.h
new file mode 100644
index 0000000..9704204
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/hash/hash_win32.h
@@ -0,0 +1,141 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_hash_hash_win32_h__
+#define INCLUDE_hash_hash_win32_h__
+
+#include "common.h"
+
+#include "hash.h"
+
+#include <wincrypt.h>
+#include <strsafe.h>
+
+enum hash_win32_prov_type {
+	INVALID = 0,
+	CRYPTOAPI,
+	CNG
+};
+
+/*
+ * CryptoAPI is available for hashing on Windows XP and newer.
+ */
+
+struct hash_cryptoapi_prov {
+	HCRYPTPROV handle;
+};
+
+/*
+ * CNG (bcrypt.dll) is significantly more performant than CryptoAPI and is
+ * preferred, however it is only available on Windows 2008 and newer and
+ * must therefore be dynamically loaded, and we must inline constants that
+ * would not exist when building in pre-Windows 2008 environments.
+ */
+
+#define GIT_HASH_CNG_DLL_NAME           "bcrypt.dll"
+
+/* BCRYPT_SHA1_ALGORITHM */
+#define GIT_HASH_CNG_HASH_TYPE          L"SHA1"
+
+/* BCRYPT_OBJECT_LENGTH */
+#define GIT_HASH_CNG_HASH_OBJECT_LEN    L"ObjectLength"
+
+/* BCRYPT_HASH_REUSEABLE_FLAGS */
+#define GIT_HASH_CNG_HASH_REUSABLE      0x00000020
+
+/* Function declarations for CNG */
+typedef NTSTATUS (WINAPI *hash_win32_cng_open_algorithm_provider_fn)(
+	HANDLE /* BCRYPT_ALG_HANDLE */ *phAlgorithm,
+	LPCWSTR pszAlgId,
+	LPCWSTR pszImplementation,
+	DWORD dwFlags);
+
+typedef NTSTATUS (WINAPI *hash_win32_cng_get_property_fn)(
+	HANDLE /* BCRYPT_HANDLE */ hObject,
+	LPCWSTR pszProperty,
+	PUCHAR pbOutput,
+	ULONG cbOutput,
+	ULONG *pcbResult,
+	ULONG dwFlags);
+
+typedef NTSTATUS (WINAPI *hash_win32_cng_create_hash_fn)(
+	HANDLE /* BCRYPT_ALG_HANDLE */ hAlgorithm,
+	HANDLE /* BCRYPT_HASH_HANDLE */ *phHash,
+	PUCHAR pbHashObject, ULONG cbHashObject,
+	PUCHAR pbSecret,
+	ULONG cbSecret,
+	ULONG dwFlags);
+
+typedef NTSTATUS (WINAPI *hash_win32_cng_finish_hash_fn)(
+	HANDLE /* BCRYPT_HASH_HANDLE */ hHash,
+	PUCHAR pbOutput,
+	ULONG cbOutput,
+	ULONG dwFlags);
+
+typedef NTSTATUS (WINAPI *hash_win32_cng_hash_data_fn)(
+	HANDLE /* BCRYPT_HASH_HANDLE */ hHash,
+	PUCHAR pbInput,
+	ULONG cbInput,
+	ULONG dwFlags);
+
+typedef NTSTATUS (WINAPI *hash_win32_cng_destroy_hash_fn)(
+	HANDLE /* BCRYPT_HASH_HANDLE */ hHash);
+
+typedef NTSTATUS (WINAPI *hash_win32_cng_close_algorithm_provider_fn)(
+	HANDLE /* BCRYPT_ALG_HANDLE */ hAlgorithm,
+	ULONG dwFlags);
+
+struct hash_cng_prov {
+	/* DLL for CNG */
+	HINSTANCE dll;
+
+	/* Function pointers for CNG */
+	hash_win32_cng_open_algorithm_provider_fn open_algorithm_provider;
+	hash_win32_cng_get_property_fn get_property;
+	hash_win32_cng_create_hash_fn create_hash;
+	hash_win32_cng_finish_hash_fn finish_hash;
+	hash_win32_cng_hash_data_fn hash_data;
+	hash_win32_cng_destroy_hash_fn destroy_hash;
+	hash_win32_cng_close_algorithm_provider_fn close_algorithm_provider;
+
+	HANDLE /* BCRYPT_ALG_HANDLE */ handle;
+	DWORD hash_object_size;
+};
+
+struct git_hash_prov {
+	enum hash_win32_prov_type type;
+
+	union {
+		struct hash_cryptoapi_prov cryptoapi;
+		struct hash_cng_prov cng;
+	} prov;
+};
+
+/* Hash contexts */
+
+struct hash_cryptoapi_ctx {
+	bool valid;
+	HCRYPTHASH hash_handle;
+};
+
+struct hash_cng_ctx {
+	bool updated;
+	HANDLE /* BCRYPT_HASH_HANDLE */ hash_handle;
+	PBYTE hash_object;
+};
+
+struct git_hash_ctx {
+	enum hash_win32_prov_type type;
+	git_hash_prov *prov;
+
+	union {
+		struct hash_cryptoapi_ctx cryptoapi;
+		struct hash_cng_ctx cng;
+	} ctx;
+};
+
+#endif

vendor/libgit2-sys/libgit2/src/hash/sha1dc/sha1.c

diff --git a/vendor/libgit2-sys/libgit2/src/hash/sha1dc/sha1.c b/vendor/libgit2-sys/libgit2/src/hash/sha1dc/sha1.c
new file mode 100644
index 0000000..25eded1
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/hash/sha1dc/sha1.c
@@ -0,0 +1,1900 @@
+/***
+* Copyright 2017 Marc Stevens <marc@marc-stevens.nl>, Dan Shumow (danshu@microsoft.com)
+* Distributed under the MIT Software License.
+* See accompanying file LICENSE.txt or copy at
+* https://opensource.org/licenses/MIT
+***/
+
+#ifndef SHA1DC_NO_STANDARD_INCLUDES
+#include <string.h>
+#include <memory.h>
+#include <stdio.h>
+#include <stdlib.h>
+#ifdef __unix__
+#include <sys/types.h> /* make sure macros like _BIG_ENDIAN visible */
+#endif
+#endif
+
+#ifdef SHA1DC_CUSTOM_INCLUDE_SHA1_C
+#include SHA1DC_CUSTOM_INCLUDE_SHA1_C
+#endif
+
+#ifndef SHA1DC_INIT_SAFE_HASH_DEFAULT
+#define SHA1DC_INIT_SAFE_HASH_DEFAULT 1
+#endif
+
+#include "sha1.h"
+#include "ubc_check.h"
+
+#if (defined(__amd64__) || defined(__amd64) || defined(__x86_64__) || defined(__x86_64) || \
+     defined(i386) || defined(__i386) || defined(__i386__) || defined(__i486__)  || \
+     defined(__i586__) || defined(__i686__) || defined(_M_IX86) || defined(__X86__) || \
+     defined(_X86_) || defined(__THW_INTEL__) || defined(__I86__) || defined(__INTEL__) || \
+     defined(__386) || defined(_M_X64) || defined(_M_AMD64))
+#define SHA1DC_ON_INTEL_LIKE_PROCESSOR
+#endif
+
+/*
+   Because Little-Endian architectures are most common,
+   we only set SHA1DC_BIGENDIAN if one of these conditions is met.
+   Note that all MSFT platforms are little endian,
+   so none of these will be defined under the MSC compiler.
+   If you are compiling on a big endian platform and your compiler does not define one of these,
+   you will have to add whatever macros your tool chain defines to indicate Big-Endianness.
+ */
+
+#if defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__)
+/*
+ * Should detect Big Endian under GCC since at least 4.6.0 (gcc svn
+ * rev #165881). See
+ * https://gcc.gnu.org/onlinedocs/cpp/Common-Predefined-Macros.html
+ *
+ * This also works under clang since 3.2, it copied the GCC-ism. See
+ * clang.git's 3b198a97d2 ("Preprocessor: add __BYTE_ORDER__
+ * predefined macro", 2012-07-27)
+ */
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+#define SHA1DC_BIGENDIAN
+#endif
+
+/* Not under GCC-alike */
+#elif defined(__BYTE_ORDER) && defined(__BIG_ENDIAN)
+/*
+ * Should detect Big Endian under glibc.git since 14245eb70e ("entered
+ * into RCS", 1992-11-25). Defined in <endian.h> which will have been
+ * brought in by standard headers. See glibc.git and
+ * https://sourceforge.net/p/predef/wiki/Endianness/
+ */
+#if __BYTE_ORDER == __BIG_ENDIAN
+#define SHA1DC_BIGENDIAN
+#endif
+
+/* Not under GCC-alike or glibc */
+#elif defined(_BYTE_ORDER) && defined(_BIG_ENDIAN) && defined(_LITTLE_ENDIAN)
+/*
+ * *BSD and newlib (embeded linux, cygwin, etc).
+ * the defined(_BIG_ENDIAN) && defined(_LITTLE_ENDIAN) part prevents
+ * this condition from matching with Solaris/sparc.
+ * (Solaris defines only one endian macro)
+ */
+#if _BYTE_ORDER == _BIG_ENDIAN
+#define SHA1DC_BIGENDIAN
+#endif
+
+/* Not under GCC-alike or glibc or *BSD or newlib */
+#elif (defined(__ARMEB__) || defined(__THUMBEB__) || defined(__AARCH64EB__) || \
+       defined(__MIPSEB__) || defined(__MIPSEB) || defined(_MIPSEB) || \
+       defined(__sparc))
+/*
+ * Should define Big Endian for a whitelist of known processors. See
+ * https://sourceforge.net/p/predef/wiki/Endianness/ and
+ * http://www.oracle.com/technetwork/server-storage/solaris/portingtosolaris-138514.html
+ */
+#define SHA1DC_BIGENDIAN
+
+/* Not under GCC-alike or glibc or *BSD or newlib or <processor whitelist> */
+#elif defined(SHA1DC_ON_INTEL_LIKE_PROCESSOR)
+/*
+ * As a last resort before we do anything else we're not 100% sure
+ * about below, we blacklist specific processors here. We could add
+ * more, see e.g. https://wiki.debian.org/ArchitectureSpecificsMemo
+ */
+#else /* Not under GCC-alike or glibc or *BSD or newlib or <processor whitelist>  or <processor blacklist> */
+
+/* We do nothing more here for now */
+/*#error "Uncomment this to see if you fall through all the detection"*/
+
+#endif /* Big Endian detection */
+
+#if (defined(SHA1DC_FORCE_LITTLEENDIAN) && defined(SHA1DC_BIGENDIAN))
+#undef SHA1DC_BIGENDIAN
+#endif
+#if (defined(SHA1DC_FORCE_BIGENDIAN) && !defined(SHA1DC_BIGENDIAN))
+#define SHA1DC_BIGENDIAN
+#endif
+/*ENDIANNESS SELECTION*/
+
+#if defined(SHA1DC_FORCE_UNALIGNED_ACCESS) || defined(SHA1DC_ON_INTEL_LIKE_PROCESSOR)
+#define SHA1DC_ALLOW_UNALIGNED_ACCESS
+#endif /*UNALIGNMENT DETECTION*/
+
+
+#define rotate_right(x,n) (((x)>>(n))|((x)<<(32-(n))))
+#define rotate_left(x,n)  (((x)<<(n))|((x)>>(32-(n))))
+
+#define sha1_bswap32(x) \
+	{x = ((x << 8) & 0xFF00FF00) | ((x >> 8) & 0xFF00FF); x = (x << 16) | (x >> 16);}
+
+#define sha1_mix(W, t)  (rotate_left(W[t - 3] ^ W[t - 8] ^ W[t - 14] ^ W[t - 16], 1))
+
+#ifdef SHA1DC_BIGENDIAN
+	#define sha1_load(m, t, temp)  { temp = m[t]; }
+#else
+	#define sha1_load(m, t, temp)  { temp = m[t]; sha1_bswap32(temp); }
+#endif
+
+#define sha1_store(W, t, x)	*(volatile uint32_t *)&W[t] = x
+
+#define sha1_f1(b,c,d) ((d)^((b)&((c)^(d))))
+#define sha1_f2(b,c,d) ((b)^(c)^(d))
+#define sha1_f3(b,c,d) (((b)&(c))+((d)&((b)^(c))))
+#define sha1_f4(b,c,d) ((b)^(c)^(d))
+
+#define HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, m, t) \
+	{ e += rotate_left(a, 5) + sha1_f1(b,c,d) + 0x5A827999 + m[t]; b = rotate_left(b, 30); }
+#define HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, m, t) \
+	{ e += rotate_left(a, 5) + sha1_f2(b,c,d) + 0x6ED9EBA1 + m[t]; b = rotate_left(b, 30); }
+#define HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, m, t) \
+	{ e += rotate_left(a, 5) + sha1_f3(b,c,d) + 0x8F1BBCDC + m[t]; b = rotate_left(b, 30); }
+#define HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, m, t) \
+	{ e += rotate_left(a, 5) + sha1_f4(b,c,d) + 0xCA62C1D6 + m[t]; b = rotate_left(b, 30); }
+
+#define HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(a, b, c, d, e, m, t) \
+	{ b = rotate_right(b, 30); e -= rotate_left(a, 5) + sha1_f1(b,c,d) + 0x5A827999 + m[t]; }
+#define HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(a, b, c, d, e, m, t) \
+	{ b = rotate_right(b, 30); e -= rotate_left(a, 5) + sha1_f2(b,c,d) + 0x6ED9EBA1 + m[t]; }
+#define HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(a, b, c, d, e, m, t) \
+	{ b = rotate_right(b, 30); e -= rotate_left(a, 5) + sha1_f3(b,c,d) + 0x8F1BBCDC + m[t]; }
+#define HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(a, b, c, d, e, m, t) \
+	{ b = rotate_right(b, 30); e -= rotate_left(a, 5) + sha1_f4(b,c,d) + 0xCA62C1D6 + m[t]; }
+
+#define SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(a, b, c, d, e, m, W, t, temp) \
+	{sha1_load(m, t, temp); sha1_store(W, t, temp); e += temp + rotate_left(a, 5) + sha1_f1(b,c,d) + 0x5A827999; b = rotate_left(b, 30);}
+
+#define SHA1COMPRESS_FULL_ROUND1_STEP_EXPAND(a, b, c, d, e, W, t, temp) \
+	{temp = sha1_mix(W, t); sha1_store(W, t, temp); e += temp + rotate_left(a, 5) + sha1_f1(b,c,d) + 0x5A827999; b = rotate_left(b, 30); }
+
+#define SHA1COMPRESS_FULL_ROUND2_STEP(a, b, c, d, e, W, t, temp) \
+	{temp = sha1_mix(W, t); sha1_store(W, t, temp); e += temp + rotate_left(a, 5) + sha1_f2(b,c,d) + 0x6ED9EBA1; b = rotate_left(b, 30); }
+
+#define SHA1COMPRESS_FULL_ROUND3_STEP(a, b, c, d, e, W, t, temp) \
+	{temp = sha1_mix(W, t); sha1_store(W, t, temp); e += temp + rotate_left(a, 5) + sha1_f3(b,c,d) + 0x8F1BBCDC; b = rotate_left(b, 30); }
+
+#define SHA1COMPRESS_FULL_ROUND4_STEP(a, b, c, d, e, W, t, temp) \
+	{temp = sha1_mix(W, t); sha1_store(W, t, temp); e += temp + rotate_left(a, 5) + sha1_f4(b,c,d) + 0xCA62C1D6; b = rotate_left(b, 30); }
+
+
+#define SHA1_STORE_STATE(i) states[i][0] = a; states[i][1] = b; states[i][2] = c; states[i][3] = d; states[i][4] = e;
+
+#ifdef BUILDNOCOLLDETECTSHA1COMPRESSION
+void sha1_compression(uint32_t ihv[5], const uint32_t m[16])
+{
+	uint32_t W[80];
+	uint32_t a,b,c,d,e;
+	unsigned i;
+
+	memcpy(W, m, 16 * 4);
+	for (i = 16; i < 80; ++i)
+		W[i] = sha1_mix(W, i);
+
+	a = ihv[0]; b = ihv[1]; c = ihv[2]; d = ihv[3]; e = ihv[4];
+
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, W, 0);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, W, 1);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, W, 2);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, W, 3);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, W, 4);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, W, 5);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, W, 6);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, W, 7);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, W, 8);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, W, 9);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, W, 10);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, W, 11);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, W, 12);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, W, 13);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, W, 14);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, W, 15);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, W, 16);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, W, 17);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, W, 18);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, W, 19);
+
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, W, 20);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, W, 21);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, W, 22);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, W, 23);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, W, 24);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, W, 25);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, W, 26);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, W, 27);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, W, 28);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, W, 29);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, W, 30);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, W, 31);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, W, 32);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, W, 33);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, W, 34);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, W, 35);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, W, 36);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, W, 37);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, W, 38);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, W, 39);
+
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, W, 40);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, W, 41);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, W, 42);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, W, 43);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, W, 44);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, W, 45);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, W, 46);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, W, 47);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, W, 48);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, W, 49);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, W, 50);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, W, 51);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, W, 52);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, W, 53);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, W, 54);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, W, 55);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, W, 56);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, W, 57);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, W, 58);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, W, 59);
+
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, W, 60);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, W, 61);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, W, 62);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, W, 63);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, W, 64);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, W, 65);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, W, 66);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, W, 67);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, W, 68);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, W, 69);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, W, 70);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, W, 71);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, W, 72);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, W, 73);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, W, 74);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, W, 75);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, W, 76);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, W, 77);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, W, 78);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, W, 79);
+
+	ihv[0] += a; ihv[1] += b; ihv[2] += c; ihv[3] += d; ihv[4] += e;
+}
+#endif /*BUILDNOCOLLDETECTSHA1COMPRESSION*/
+
+
+static void sha1_compression_W(uint32_t ihv[5], const uint32_t W[80])
+{
+	uint32_t a = ihv[0], b = ihv[1], c = ihv[2], d = ihv[3], e = ihv[4];
+
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, W, 0);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, W, 1);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, W, 2);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, W, 3);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, W, 4);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, W, 5);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, W, 6);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, W, 7);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, W, 8);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, W, 9);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, W, 10);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, W, 11);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, W, 12);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, W, 13);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, W, 14);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, W, 15);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, W, 16);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, W, 17);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, W, 18);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, W, 19);
+
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, W, 20);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, W, 21);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, W, 22);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, W, 23);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, W, 24);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, W, 25);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, W, 26);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, W, 27);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, W, 28);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, W, 29);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, W, 30);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, W, 31);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, W, 32);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, W, 33);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, W, 34);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, W, 35);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, W, 36);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, W, 37);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, W, 38);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, W, 39);
+
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, W, 40);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, W, 41);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, W, 42);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, W, 43);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, W, 44);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, W, 45);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, W, 46);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, W, 47);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, W, 48);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, W, 49);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, W, 50);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, W, 51);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, W, 52);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, W, 53);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, W, 54);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, W, 55);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, W, 56);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, W, 57);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, W, 58);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, W, 59);
+
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, W, 60);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, W, 61);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, W, 62);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, W, 63);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, W, 64);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, W, 65);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, W, 66);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, W, 67);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, W, 68);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, W, 69);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, W, 70);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, W, 71);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, W, 72);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, W, 73);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, W, 74);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, W, 75);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, W, 76);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, W, 77);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, W, 78);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, W, 79);
+
+	ihv[0] += a; ihv[1] += b; ihv[2] += c; ihv[3] += d; ihv[4] += e;
+}
+
+
+
+void sha1_compression_states(uint32_t ihv[5], const uint32_t m[16], uint32_t W[80], uint32_t states[80][5])
+{
+	uint32_t a = ihv[0], b = ihv[1], c = ihv[2], d = ihv[3], e = ihv[4];
+	uint32_t temp;
+
+#ifdef DOSTORESTATE00
+	SHA1_STORE_STATE(0)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(a, b, c, d, e, m, W, 0, temp);
+
+#ifdef DOSTORESTATE01
+	SHA1_STORE_STATE(1)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(e, a, b, c, d, m, W, 1, temp);
+
+#ifdef DOSTORESTATE02
+	SHA1_STORE_STATE(2)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(d, e, a, b, c, m, W, 2, temp);
+
+#ifdef DOSTORESTATE03
+	SHA1_STORE_STATE(3)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(c, d, e, a, b, m, W, 3, temp);
+
+#ifdef DOSTORESTATE04
+	SHA1_STORE_STATE(4)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(b, c, d, e, a, m, W, 4, temp);
+
+#ifdef DOSTORESTATE05
+	SHA1_STORE_STATE(5)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(a, b, c, d, e, m, W, 5, temp);
+
+#ifdef DOSTORESTATE06
+	SHA1_STORE_STATE(6)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(e, a, b, c, d, m, W, 6, temp);
+
+#ifdef DOSTORESTATE07
+	SHA1_STORE_STATE(7)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(d, e, a, b, c, m, W, 7, temp);
+
+#ifdef DOSTORESTATE08
+	SHA1_STORE_STATE(8)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(c, d, e, a, b, m, W, 8, temp);
+
+#ifdef DOSTORESTATE09
+	SHA1_STORE_STATE(9)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(b, c, d, e, a, m, W, 9, temp);
+
+#ifdef DOSTORESTATE10
+	SHA1_STORE_STATE(10)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(a, b, c, d, e, m, W, 10, temp);
+
+#ifdef DOSTORESTATE11
+	SHA1_STORE_STATE(11)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(e, a, b, c, d, m, W, 11, temp);
+
+#ifdef DOSTORESTATE12
+	SHA1_STORE_STATE(12)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(d, e, a, b, c, m, W, 12, temp);
+
+#ifdef DOSTORESTATE13
+	SHA1_STORE_STATE(13)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(c, d, e, a, b, m, W, 13, temp);
+
+#ifdef DOSTORESTATE14
+	SHA1_STORE_STATE(14)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(b, c, d, e, a, m, W, 14, temp);
+
+#ifdef DOSTORESTATE15
+	SHA1_STORE_STATE(15)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(a, b, c, d, e, m, W, 15, temp);
+
+#ifdef DOSTORESTATE16
+	SHA1_STORE_STATE(16)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_EXPAND(e, a, b, c, d, W, 16, temp);
+
+#ifdef DOSTORESTATE17
+	SHA1_STORE_STATE(17)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_EXPAND(d, e, a, b, c, W, 17, temp);
+
+#ifdef DOSTORESTATE18
+	SHA1_STORE_STATE(18)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_EXPAND(c, d, e, a, b, W, 18, temp);
+
+#ifdef DOSTORESTATE19
+	SHA1_STORE_STATE(19)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_EXPAND(b, c, d, e, a, W, 19, temp);
+
+
+
+#ifdef DOSTORESTATE20
+	SHA1_STORE_STATE(20)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(a, b, c, d, e, W, 20, temp);
+
+#ifdef DOSTORESTATE21
+	SHA1_STORE_STATE(21)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(e, a, b, c, d, W, 21, temp);
+
+#ifdef DOSTORESTATE22
+	SHA1_STORE_STATE(22)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(d, e, a, b, c, W, 22, temp);
+
+#ifdef DOSTORESTATE23
+	SHA1_STORE_STATE(23)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(c, d, e, a, b, W, 23, temp);
+
+#ifdef DOSTORESTATE24
+	SHA1_STORE_STATE(24)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(b, c, d, e, a, W, 24, temp);
+
+#ifdef DOSTORESTATE25
+	SHA1_STORE_STATE(25)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(a, b, c, d, e, W, 25, temp);
+
+#ifdef DOSTORESTATE26
+	SHA1_STORE_STATE(26)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(e, a, b, c, d, W, 26, temp);
+
+#ifdef DOSTORESTATE27
+	SHA1_STORE_STATE(27)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(d, e, a, b, c, W, 27, temp);
+
+#ifdef DOSTORESTATE28
+	SHA1_STORE_STATE(28)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(c, d, e, a, b, W, 28, temp);
+
+#ifdef DOSTORESTATE29
+	SHA1_STORE_STATE(29)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(b, c, d, e, a, W, 29, temp);
+
+#ifdef DOSTORESTATE30
+	SHA1_STORE_STATE(30)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(a, b, c, d, e, W, 30, temp);
+
+#ifdef DOSTORESTATE31
+	SHA1_STORE_STATE(31)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(e, a, b, c, d, W, 31, temp);
+
+#ifdef DOSTORESTATE32
+	SHA1_STORE_STATE(32)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(d, e, a, b, c, W, 32, temp);
+
+#ifdef DOSTORESTATE33
+	SHA1_STORE_STATE(33)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(c, d, e, a, b, W, 33, temp);
+
+#ifdef DOSTORESTATE34
+	SHA1_STORE_STATE(34)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(b, c, d, e, a, W, 34, temp);
+
+#ifdef DOSTORESTATE35
+	SHA1_STORE_STATE(35)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(a, b, c, d, e, W, 35, temp);
+
+#ifdef DOSTORESTATE36
+	SHA1_STORE_STATE(36)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(e, a, b, c, d, W, 36, temp);
+
+#ifdef DOSTORESTATE37
+	SHA1_STORE_STATE(37)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(d, e, a, b, c, W, 37, temp);
+
+#ifdef DOSTORESTATE38
+	SHA1_STORE_STATE(38)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(c, d, e, a, b, W, 38, temp);
+
+#ifdef DOSTORESTATE39
+	SHA1_STORE_STATE(39)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(b, c, d, e, a, W, 39, temp);
+
+
+
+#ifdef DOSTORESTATE40
+	SHA1_STORE_STATE(40)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(a, b, c, d, e, W, 40, temp);
+
+#ifdef DOSTORESTATE41
+	SHA1_STORE_STATE(41)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(e, a, b, c, d, W, 41, temp);
+
+#ifdef DOSTORESTATE42
+	SHA1_STORE_STATE(42)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(d, e, a, b, c, W, 42, temp);
+
+#ifdef DOSTORESTATE43
+	SHA1_STORE_STATE(43)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(c, d, e, a, b, W, 43, temp);
+
+#ifdef DOSTORESTATE44
+	SHA1_STORE_STATE(44)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(b, c, d, e, a, W, 44, temp);
+
+#ifdef DOSTORESTATE45
+	SHA1_STORE_STATE(45)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(a, b, c, d, e, W, 45, temp);
+
+#ifdef DOSTORESTATE46
+	SHA1_STORE_STATE(46)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(e, a, b, c, d, W, 46, temp);
+
+#ifdef DOSTORESTATE47
+	SHA1_STORE_STATE(47)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(d, e, a, b, c, W, 47, temp);
+
+#ifdef DOSTORESTATE48
+	SHA1_STORE_STATE(48)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(c, d, e, a, b, W, 48, temp);
+
+#ifdef DOSTORESTATE49
+	SHA1_STORE_STATE(49)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(b, c, d, e, a, W, 49, temp);
+
+#ifdef DOSTORESTATE50
+	SHA1_STORE_STATE(50)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(a, b, c, d, e, W, 50, temp);
+
+#ifdef DOSTORESTATE51
+	SHA1_STORE_STATE(51)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(e, a, b, c, d, W, 51, temp);
+
+#ifdef DOSTORESTATE52
+	SHA1_STORE_STATE(52)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(d, e, a, b, c, W, 52, temp);
+
+#ifdef DOSTORESTATE53
+	SHA1_STORE_STATE(53)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(c, d, e, a, b, W, 53, temp);
+
+#ifdef DOSTORESTATE54
+	SHA1_STORE_STATE(54)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(b, c, d, e, a, W, 54, temp);
+
+#ifdef DOSTORESTATE55
+	SHA1_STORE_STATE(55)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(a, b, c, d, e, W, 55, temp);
+
+#ifdef DOSTORESTATE56
+	SHA1_STORE_STATE(56)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(e, a, b, c, d, W, 56, temp);
+
+#ifdef DOSTORESTATE57
+	SHA1_STORE_STATE(57)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(d, e, a, b, c, W, 57, temp);
+
+#ifdef DOSTORESTATE58
+	SHA1_STORE_STATE(58)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(c, d, e, a, b, W, 58, temp);
+
+#ifdef DOSTORESTATE59
+	SHA1_STORE_STATE(59)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(b, c, d, e, a, W, 59, temp);
+
+
+
+
+#ifdef DOSTORESTATE60
+	SHA1_STORE_STATE(60)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(a, b, c, d, e, W, 60, temp);
+
+#ifdef DOSTORESTATE61
+	SHA1_STORE_STATE(61)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(e, a, b, c, d, W, 61, temp);
+
+#ifdef DOSTORESTATE62
+	SHA1_STORE_STATE(62)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(d, e, a, b, c, W, 62, temp);
+
+#ifdef DOSTORESTATE63
+	SHA1_STORE_STATE(63)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(c, d, e, a, b, W, 63, temp);
+
+#ifdef DOSTORESTATE64
+	SHA1_STORE_STATE(64)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(b, c, d, e, a, W, 64, temp);
+
+#ifdef DOSTORESTATE65
+	SHA1_STORE_STATE(65)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(a, b, c, d, e, W, 65, temp);
+
+#ifdef DOSTORESTATE66
+	SHA1_STORE_STATE(66)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(e, a, b, c, d, W, 66, temp);
+
+#ifdef DOSTORESTATE67
+	SHA1_STORE_STATE(67)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(d, e, a, b, c, W, 67, temp);
+
+#ifdef DOSTORESTATE68
+	SHA1_STORE_STATE(68)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(c, d, e, a, b, W, 68, temp);
+
+#ifdef DOSTORESTATE69
+	SHA1_STORE_STATE(69)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(b, c, d, e, a, W, 69, temp);
+
+#ifdef DOSTORESTATE70
+	SHA1_STORE_STATE(70)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(a, b, c, d, e, W, 70, temp);
+
+#ifdef DOSTORESTATE71
+	SHA1_STORE_STATE(71)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(e, a, b, c, d, W, 71, temp);
+
+#ifdef DOSTORESTATE72
+	SHA1_STORE_STATE(72)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(d, e, a, b, c, W, 72, temp);
+
+#ifdef DOSTORESTATE73
+	SHA1_STORE_STATE(73)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(c, d, e, a, b, W, 73, temp);
+
+#ifdef DOSTORESTATE74
+	SHA1_STORE_STATE(74)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(b, c, d, e, a, W, 74, temp);
+
+#ifdef DOSTORESTATE75
+	SHA1_STORE_STATE(75)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(a, b, c, d, e, W, 75, temp);
+
+#ifdef DOSTORESTATE76
+	SHA1_STORE_STATE(76)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(e, a, b, c, d, W, 76, temp);
+
+#ifdef DOSTORESTATE77
+	SHA1_STORE_STATE(77)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(d, e, a, b, c, W, 77, temp);
+
+#ifdef DOSTORESTATE78
+	SHA1_STORE_STATE(78)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(c, d, e, a, b, W, 78, temp);
+
+#ifdef DOSTORESTATE79
+	SHA1_STORE_STATE(79)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(b, c, d, e, a, W, 79, temp);
+
+
+
+	ihv[0] += a; ihv[1] += b; ihv[2] += c; ihv[3] += d; ihv[4] += e;
+}
+
+
+
+
+#define SHA1_RECOMPRESS(t) \
+static void sha1recompress_fast_ ## t (uint32_t ihvin[5], uint32_t ihvout[5], const uint32_t me2[80], const uint32_t state[5]) \
+{ \
+	uint32_t a = state[0], b = state[1], c = state[2], d = state[3], e = state[4]; \
+	if (t > 79) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(b, c, d, e, a, me2, 79); \
+	if (t > 78) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(c, d, e, a, b, me2, 78); \
+	if (t > 77) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(d, e, a, b, c, me2, 77); \
+	if (t > 76) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(e, a, b, c, d, me2, 76); \
+	if (t > 75) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(a, b, c, d, e, me2, 75); \
+	if (t > 74) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(b, c, d, e, a, me2, 74); \
+	if (t > 73) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(c, d, e, a, b, me2, 73); \
+	if (t > 72) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(d, e, a, b, c, me2, 72); \
+	if (t > 71) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(e, a, b, c, d, me2, 71); \
+	if (t > 70) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(a, b, c, d, e, me2, 70); \
+	if (t > 69) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(b, c, d, e, a, me2, 69); \
+	if (t > 68) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(c, d, e, a, b, me2, 68); \
+	if (t > 67) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(d, e, a, b, c, me2, 67); \
+	if (t > 66) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(e, a, b, c, d, me2, 66); \
+	if (t > 65) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(a, b, c, d, e, me2, 65); \
+	if (t > 64) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(b, c, d, e, a, me2, 64); \
+	if (t > 63) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(c, d, e, a, b, me2, 63); \
+	if (t > 62) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(d, e, a, b, c, me2, 62); \
+	if (t > 61) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(e, a, b, c, d, me2, 61); \
+	if (t > 60) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(a, b, c, d, e, me2, 60); \
+	if (t > 59) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(b, c, d, e, a, me2, 59); \
+	if (t > 58) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(c, d, e, a, b, me2, 58); \
+	if (t > 57) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(d, e, a, b, c, me2, 57); \
+	if (t > 56) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(e, a, b, c, d, me2, 56); \
+	if (t > 55) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(a, b, c, d, e, me2, 55); \
+	if (t > 54) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(b, c, d, e, a, me2, 54); \
+	if (t > 53) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(c, d, e, a, b, me2, 53); \
+	if (t > 52) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(d, e, a, b, c, me2, 52); \
+	if (t > 51) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(e, a, b, c, d, me2, 51); \
+	if (t > 50) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(a, b, c, d, e, me2, 50); \
+	if (t > 49) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(b, c, d, e, a, me2, 49); \
+	if (t > 48) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(c, d, e, a, b, me2, 48); \
+	if (t > 47) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(d, e, a, b, c, me2, 47); \
+	if (t > 46) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(e, a, b, c, d, me2, 46); \
+	if (t > 45) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(a, b, c, d, e, me2, 45); \
+	if (t > 44) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(b, c, d, e, a, me2, 44); \
+	if (t > 43) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(c, d, e, a, b, me2, 43); \
+	if (t > 42) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(d, e, a, b, c, me2, 42); \
+	if (t > 41) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(e, a, b, c, d, me2, 41); \
+	if (t > 40) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(a, b, c, d, e, me2, 40); \
+	if (t > 39) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(b, c, d, e, a, me2, 39); \
+	if (t > 38) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(c, d, e, a, b, me2, 38); \
+	if (t > 37) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(d, e, a, b, c, me2, 37); \
+	if (t > 36) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(e, a, b, c, d, me2, 36); \
+	if (t > 35) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(a, b, c, d, e, me2, 35); \
+	if (t > 34) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(b, c, d, e, a, me2, 34); \
+	if (t > 33) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(c, d, e, a, b, me2, 33); \
+	if (t > 32) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(d, e, a, b, c, me2, 32); \
+	if (t > 31) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(e, a, b, c, d, me2, 31); \
+	if (t > 30) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(a, b, c, d, e, me2, 30); \
+	if (t > 29) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(b, c, d, e, a, me2, 29); \
+	if (t > 28) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(c, d, e, a, b, me2, 28); \
+	if (t > 27) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(d, e, a, b, c, me2, 27); \
+	if (t > 26) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(e, a, b, c, d, me2, 26); \
+	if (t > 25) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(a, b, c, d, e, me2, 25); \
+	if (t > 24) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(b, c, d, e, a, me2, 24); \
+	if (t > 23) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(c, d, e, a, b, me2, 23); \
+	if (t > 22) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(d, e, a, b, c, me2, 22); \
+	if (t > 21) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(e, a, b, c, d, me2, 21); \
+	if (t > 20) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(a, b, c, d, e, me2, 20); \
+	if (t > 19) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(b, c, d, e, a, me2, 19); \
+	if (t > 18) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(c, d, e, a, b, me2, 18); \
+	if (t > 17) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(d, e, a, b, c, me2, 17); \
+	if (t > 16) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(e, a, b, c, d, me2, 16); \
+	if (t > 15) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(a, b, c, d, e, me2, 15); \
+	if (t > 14) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(b, c, d, e, a, me2, 14); \
+	if (t > 13) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(c, d, e, a, b, me2, 13); \
+	if (t > 12) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(d, e, a, b, c, me2, 12); \
+	if (t > 11) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(e, a, b, c, d, me2, 11); \
+	if (t > 10) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(a, b, c, d, e, me2, 10); \
+	if (t > 9) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(b, c, d, e, a, me2, 9); \
+	if (t > 8) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(c, d, e, a, b, me2, 8); \
+	if (t > 7) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(d, e, a, b, c, me2, 7); \
+	if (t > 6) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(e, a, b, c, d, me2, 6); \
+	if (t > 5) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(a, b, c, d, e, me2, 5); \
+	if (t > 4) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(b, c, d, e, a, me2, 4); \
+	if (t > 3) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(c, d, e, a, b, me2, 3); \
+	if (t > 2) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(d, e, a, b, c, me2, 2); \
+	if (t > 1) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(e, a, b, c, d, me2, 1); \
+	if (t > 0) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(a, b, c, d, e, me2, 0); \
+	ihvin[0] = a; ihvin[1] = b; ihvin[2] = c; ihvin[3] = d; ihvin[4] = e; \
+	a = state[0]; b = state[1]; c = state[2]; d = state[3]; e = state[4]; \
+	if (t <= 0) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, me2, 0); \
+	if (t <= 1) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, me2, 1); \
+	if (t <= 2) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, me2, 2); \
+	if (t <= 3) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, me2, 3); \
+	if (t <= 4) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, me2, 4); \
+	if (t <= 5) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, me2, 5); \
+	if (t <= 6) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, me2, 6); \
+	if (t <= 7) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, me2, 7); \
+	if (t <= 8) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, me2, 8); \
+	if (t <= 9) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, me2, 9); \
+	if (t <= 10) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, me2, 10); \
+	if (t <= 11) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, me2, 11); \
+	if (t <= 12) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, me2, 12); \
+	if (t <= 13) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, me2, 13); \
+	if (t <= 14) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, me2, 14); \
+	if (t <= 15) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, me2, 15); \
+	if (t <= 16) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, me2, 16); \
+	if (t <= 17) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, me2, 17); \
+	if (t <= 18) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, me2, 18); \
+	if (t <= 19) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, me2, 19); \
+	if (t <= 20) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, me2, 20); \
+	if (t <= 21) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, me2, 21); \
+	if (t <= 22) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, me2, 22); \
+	if (t <= 23) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, me2, 23); \
+	if (t <= 24) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, me2, 24); \
+	if (t <= 25) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, me2, 25); \
+	if (t <= 26) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, me2, 26); \
+	if (t <= 27) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, me2, 27); \
+	if (t <= 28) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, me2, 28); \
+	if (t <= 29) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, me2, 29); \
+	if (t <= 30) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, me2, 30); \
+	if (t <= 31) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, me2, 31); \
+	if (t <= 32) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, me2, 32); \
+	if (t <= 33) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, me2, 33); \
+	if (t <= 34) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, me2, 34); \
+	if (t <= 35) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, me2, 35); \
+	if (t <= 36) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, me2, 36); \
+	if (t <= 37) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, me2, 37); \
+	if (t <= 38) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, me2, 38); \
+	if (t <= 39) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, me2, 39); \
+	if (t <= 40) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, me2, 40); \
+	if (t <= 41) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, me2, 41); \
+	if (t <= 42) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, me2, 42); \
+	if (t <= 43) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, me2, 43); \
+	if (t <= 44) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, me2, 44); \
+	if (t <= 45) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, me2, 45); \
+	if (t <= 46) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, me2, 46); \
+	if (t <= 47) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, me2, 47); \
+	if (t <= 48) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, me2, 48); \
+	if (t <= 49) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, me2, 49); \
+	if (t <= 50) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, me2, 50); \
+	if (t <= 51) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, me2, 51); \
+	if (t <= 52) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, me2, 52); \
+	if (t <= 53) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, me2, 53); \
+	if (t <= 54) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, me2, 54); \
+	if (t <= 55) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, me2, 55); \
+	if (t <= 56) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, me2, 56); \
+	if (t <= 57) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, me2, 57); \
+	if (t <= 58) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, me2, 58); \
+	if (t <= 59) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, me2, 59); \
+	if (t <= 60) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, me2, 60); \
+	if (t <= 61) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, me2, 61); \
+	if (t <= 62) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, me2, 62); \
+	if (t <= 63) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, me2, 63); \
+	if (t <= 64) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, me2, 64); \
+	if (t <= 65) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, me2, 65); \
+	if (t <= 66) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, me2, 66); \
+	if (t <= 67) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, me2, 67); \
+	if (t <= 68) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, me2, 68); \
+	if (t <= 69) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, me2, 69); \
+	if (t <= 70) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, me2, 70); \
+	if (t <= 71) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, me2, 71); \
+	if (t <= 72) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, me2, 72); \
+	if (t <= 73) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, me2, 73); \
+	if (t <= 74) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, me2, 74); \
+	if (t <= 75) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, me2, 75); \
+	if (t <= 76) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, me2, 76); \
+	if (t <= 77) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, me2, 77); \
+	if (t <= 78) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, me2, 78); \
+	if (t <= 79) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, me2, 79); \
+	ihvout[0] = ihvin[0] + a; ihvout[1] = ihvin[1] + b; ihvout[2] = ihvin[2] + c; ihvout[3] = ihvin[3] + d; ihvout[4] = ihvin[4] + e; \
+}
+
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable: 4127)  /* Compiler complains about the checks in the above macro being constant. */
+#endif
+
+#ifdef DOSTORESTATE0
+SHA1_RECOMPRESS(0)
+#endif
+
+#ifdef DOSTORESTATE1
+SHA1_RECOMPRESS(1)
+#endif
+
+#ifdef DOSTORESTATE2
+SHA1_RECOMPRESS(2)
+#endif
+
+#ifdef DOSTORESTATE3
+SHA1_RECOMPRESS(3)
+#endif
+
+#ifdef DOSTORESTATE4
+SHA1_RECOMPRESS(4)
+#endif
+
+#ifdef DOSTORESTATE5
+SHA1_RECOMPRESS(5)
+#endif
+
+#ifdef DOSTORESTATE6
+SHA1_RECOMPRESS(6)
+#endif
+
+#ifdef DOSTORESTATE7
+SHA1_RECOMPRESS(7)
+#endif
+
+#ifdef DOSTORESTATE8
+SHA1_RECOMPRESS(8)
+#endif
+
+#ifdef DOSTORESTATE9
+SHA1_RECOMPRESS(9)
+#endif
+
+#ifdef DOSTORESTATE10
+SHA1_RECOMPRESS(10)
+#endif
+
+#ifdef DOSTORESTATE11
+SHA1_RECOMPRESS(11)
+#endif
+
+#ifdef DOSTORESTATE12
+SHA1_RECOMPRESS(12)
+#endif
+
+#ifdef DOSTORESTATE13
+SHA1_RECOMPRESS(13)
+#endif
+
+#ifdef DOSTORESTATE14
+SHA1_RECOMPRESS(14)
+#endif
+
+#ifdef DOSTORESTATE15
+SHA1_RECOMPRESS(15)
+#endif
+
+#ifdef DOSTORESTATE16
+SHA1_RECOMPRESS(16)
+#endif
+
+#ifdef DOSTORESTATE17
+SHA1_RECOMPRESS(17)
+#endif
+
+#ifdef DOSTORESTATE18
+SHA1_RECOMPRESS(18)
+#endif
+
+#ifdef DOSTORESTATE19
+SHA1_RECOMPRESS(19)
+#endif
+
+#ifdef DOSTORESTATE20
+SHA1_RECOMPRESS(20)
+#endif
+
+#ifdef DOSTORESTATE21
+SHA1_RECOMPRESS(21)
+#endif
+
+#ifdef DOSTORESTATE22
+SHA1_RECOMPRESS(22)
+#endif
+
+#ifdef DOSTORESTATE23
+SHA1_RECOMPRESS(23)
+#endif
+
+#ifdef DOSTORESTATE24
+SHA1_RECOMPRESS(24)
+#endif
+
+#ifdef DOSTORESTATE25
+SHA1_RECOMPRESS(25)
+#endif
+
+#ifdef DOSTORESTATE26
+SHA1_RECOMPRESS(26)
+#endif
+
+#ifdef DOSTORESTATE27
+SHA1_RECOMPRESS(27)
+#endif
+
+#ifdef DOSTORESTATE28
+SHA1_RECOMPRESS(28)
+#endif
+
+#ifdef DOSTORESTATE29
+SHA1_RECOMPRESS(29)
+#endif
+
+#ifdef DOSTORESTATE30
+SHA1_RECOMPRESS(30)
+#endif
+
+#ifdef DOSTORESTATE31
+SHA1_RECOMPRESS(31)
+#endif
+
+#ifdef DOSTORESTATE32
+SHA1_RECOMPRESS(32)
+#endif
+
+#ifdef DOSTORESTATE33
+SHA1_RECOMPRESS(33)
+#endif
+
+#ifdef DOSTORESTATE34
+SHA1_RECOMPRESS(34)
+#endif
+
+#ifdef DOSTORESTATE35
+SHA1_RECOMPRESS(35)
+#endif
+
+#ifdef DOSTORESTATE36
+SHA1_RECOMPRESS(36)
+#endif
+
+#ifdef DOSTORESTATE37
+SHA1_RECOMPRESS(37)
+#endif
+
+#ifdef DOSTORESTATE38
+SHA1_RECOMPRESS(38)
+#endif
+
+#ifdef DOSTORESTATE39
+SHA1_RECOMPRESS(39)
+#endif
+
+#ifdef DOSTORESTATE40
+SHA1_RECOMPRESS(40)
+#endif
+
+#ifdef DOSTORESTATE41
+SHA1_RECOMPRESS(41)
+#endif
+
+#ifdef DOSTORESTATE42
+SHA1_RECOMPRESS(42)
+#endif
+
+#ifdef DOSTORESTATE43
+SHA1_RECOMPRESS(43)
+#endif
+
+#ifdef DOSTORESTATE44
+SHA1_RECOMPRESS(44)
+#endif
+
+#ifdef DOSTORESTATE45
+SHA1_RECOMPRESS(45)
+#endif
+
+#ifdef DOSTORESTATE46
+SHA1_RECOMPRESS(46)
+#endif
+
+#ifdef DOSTORESTATE47
+SHA1_RECOMPRESS(47)
+#endif
+
+#ifdef DOSTORESTATE48
+SHA1_RECOMPRESS(48)
+#endif
+
+#ifdef DOSTORESTATE49
+SHA1_RECOMPRESS(49)
+#endif
+
+#ifdef DOSTORESTATE50
+SHA1_RECOMPRESS(50)
+#endif
+
+#ifdef DOSTORESTATE51
+SHA1_RECOMPRESS(51)
+#endif
+
+#ifdef DOSTORESTATE52
+SHA1_RECOMPRESS(52)
+#endif
+
+#ifdef DOSTORESTATE53
+SHA1_RECOMPRESS(53)
+#endif
+
+#ifdef DOSTORESTATE54
+SHA1_RECOMPRESS(54)
+#endif
+
+#ifdef DOSTORESTATE55
+SHA1_RECOMPRESS(55)
+#endif
+
+#ifdef DOSTORESTATE56
+SHA1_RECOMPRESS(56)
+#endif
+
+#ifdef DOSTORESTATE57
+SHA1_RECOMPRESS(57)
+#endif
+
+#ifdef DOSTORESTATE58
+SHA1_RECOMPRESS(58)
+#endif
+
+#ifdef DOSTORESTATE59
+SHA1_RECOMPRESS(59)
+#endif
+
+#ifdef DOSTORESTATE60
+SHA1_RECOMPRESS(60)
+#endif
+
+#ifdef DOSTORESTATE61
+SHA1_RECOMPRESS(61)
+#endif
+
+#ifdef DOSTORESTATE62
+SHA1_RECOMPRESS(62)
+#endif
+
+#ifdef DOSTORESTATE63
+SHA1_RECOMPRESS(63)
+#endif
+
+#ifdef DOSTORESTATE64
+SHA1_RECOMPRESS(64)
+#endif
+
+#ifdef DOSTORESTATE65
+SHA1_RECOMPRESS(65)
+#endif
+
+#ifdef DOSTORESTATE66
+SHA1_RECOMPRESS(66)
+#endif
+
+#ifdef DOSTORESTATE67
+SHA1_RECOMPRESS(67)
+#endif
+
+#ifdef DOSTORESTATE68
+SHA1_RECOMPRESS(68)
+#endif
+
+#ifdef DOSTORESTATE69
+SHA1_RECOMPRESS(69)
+#endif
+
+#ifdef DOSTORESTATE70
+SHA1_RECOMPRESS(70)
+#endif
+
+#ifdef DOSTORESTATE71
+SHA1_RECOMPRESS(71)
+#endif
+
+#ifdef DOSTORESTATE72
+SHA1_RECOMPRESS(72)
+#endif
+
+#ifdef DOSTORESTATE73
+SHA1_RECOMPRESS(73)
+#endif
+
+#ifdef DOSTORESTATE74
+SHA1_RECOMPRESS(74)
+#endif
+
+#ifdef DOSTORESTATE75
+SHA1_RECOMPRESS(75)
+#endif
+
+#ifdef DOSTORESTATE76
+SHA1_RECOMPRESS(76)
+#endif
+
+#ifdef DOSTORESTATE77
+SHA1_RECOMPRESS(77)
+#endif
+
+#ifdef DOSTORESTATE78
+SHA1_RECOMPRESS(78)
+#endif
+
+#ifdef DOSTORESTATE79
+SHA1_RECOMPRESS(79)
+#endif
+
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
+static void sha1_recompression_step(uint32_t step, uint32_t ihvin[5], uint32_t ihvout[5], const uint32_t me2[80], const uint32_t state[5])
+{
+	switch (step)
+	{
+#ifdef DOSTORESTATE0
+	case 0:
+		sha1recompress_fast_0(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE1
+	case 1:
+		sha1recompress_fast_1(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE2
+	case 2:
+		sha1recompress_fast_2(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE3
+	case 3:
+		sha1recompress_fast_3(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE4
+	case 4:
+		sha1recompress_fast_4(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE5
+	case 5:
+		sha1recompress_fast_5(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE6
+	case 6:
+		sha1recompress_fast_6(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE7
+	case 7:
+		sha1recompress_fast_7(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE8
+	case 8:
+		sha1recompress_fast_8(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE9
+	case 9:
+		sha1recompress_fast_9(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE10
+	case 10:
+		sha1recompress_fast_10(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE11
+	case 11:
+		sha1recompress_fast_11(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE12
+	case 12:
+		sha1recompress_fast_12(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE13
+	case 13:
+		sha1recompress_fast_13(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE14
+	case 14:
+		sha1recompress_fast_14(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE15
+	case 15:
+		sha1recompress_fast_15(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE16
+	case 16:
+		sha1recompress_fast_16(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE17
+	case 17:
+		sha1recompress_fast_17(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE18
+	case 18:
+		sha1recompress_fast_18(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE19
+	case 19:
+		sha1recompress_fast_19(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE20
+	case 20:
+		sha1recompress_fast_20(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE21
+	case 21:
+		sha1recompress_fast_21(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE22
+	case 22:
+		sha1recompress_fast_22(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE23
+	case 23:
+		sha1recompress_fast_23(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE24
+	case 24:
+		sha1recompress_fast_24(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE25
+	case 25:
+		sha1recompress_fast_25(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE26
+	case 26:
+		sha1recompress_fast_26(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE27
+	case 27:
+		sha1recompress_fast_27(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE28
+	case 28:
+		sha1recompress_fast_28(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE29
+	case 29:
+		sha1recompress_fast_29(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE30
+	case 30:
+		sha1recompress_fast_30(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE31
+	case 31:
+		sha1recompress_fast_31(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE32
+	case 32:
+		sha1recompress_fast_32(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE33
+	case 33:
+		sha1recompress_fast_33(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE34
+	case 34:
+		sha1recompress_fast_34(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE35
+	case 35:
+		sha1recompress_fast_35(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE36
+	case 36:
+		sha1recompress_fast_36(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE37
+	case 37:
+		sha1recompress_fast_37(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE38
+	case 38:
+		sha1recompress_fast_38(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE39
+	case 39:
+		sha1recompress_fast_39(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE40
+	case 40:
+		sha1recompress_fast_40(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE41
+	case 41:
+		sha1recompress_fast_41(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE42
+	case 42:
+		sha1recompress_fast_42(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE43
+	case 43:
+		sha1recompress_fast_43(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE44
+	case 44:
+		sha1recompress_fast_44(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE45
+	case 45:
+		sha1recompress_fast_45(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE46
+	case 46:
+		sha1recompress_fast_46(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE47
+	case 47:
+		sha1recompress_fast_47(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE48
+	case 48:
+		sha1recompress_fast_48(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE49
+	case 49:
+		sha1recompress_fast_49(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE50
+	case 50:
+		sha1recompress_fast_50(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE51
+	case 51:
+		sha1recompress_fast_51(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE52
+	case 52:
+		sha1recompress_fast_52(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE53
+	case 53:
+		sha1recompress_fast_53(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE54
+	case 54:
+		sha1recompress_fast_54(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE55
+	case 55:
+		sha1recompress_fast_55(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE56
+	case 56:
+		sha1recompress_fast_56(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE57
+	case 57:
+		sha1recompress_fast_57(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE58
+	case 58:
+		sha1recompress_fast_58(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE59
+	case 59:
+		sha1recompress_fast_59(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE60
+	case 60:
+		sha1recompress_fast_60(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE61
+	case 61:
+		sha1recompress_fast_61(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE62
+	case 62:
+		sha1recompress_fast_62(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE63
+	case 63:
+		sha1recompress_fast_63(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE64
+	case 64:
+		sha1recompress_fast_64(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE65
+	case 65:
+		sha1recompress_fast_65(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE66
+	case 66:
+		sha1recompress_fast_66(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE67
+	case 67:
+		sha1recompress_fast_67(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE68
+	case 68:
+		sha1recompress_fast_68(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE69
+	case 69:
+		sha1recompress_fast_69(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE70
+	case 70:
+		sha1recompress_fast_70(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE71
+	case 71:
+		sha1recompress_fast_71(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE72
+	case 72:
+		sha1recompress_fast_72(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE73
+	case 73:
+		sha1recompress_fast_73(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE74
+	case 74:
+		sha1recompress_fast_74(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE75
+	case 75:
+		sha1recompress_fast_75(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE76
+	case 76:
+		sha1recompress_fast_76(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE77
+	case 77:
+		sha1recompress_fast_77(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE78
+	case 78:
+		sha1recompress_fast_78(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE79
+	case 79:
+		sha1recompress_fast_79(ihvin, ihvout, me2, state);
+		break;
+#endif
+	default:
+		abort();
+	}
+
+}
+
+
+
+static void sha1_process(SHA1_CTX* ctx, const uint32_t block[16])
+{
+	unsigned i, j;
+	uint32_t ubc_dv_mask[DVMASKSIZE] = { 0xFFFFFFFF };
+	uint32_t ihvtmp[5];
+
+	ctx->ihv1[0] = ctx->ihv[0];
+	ctx->ihv1[1] = ctx->ihv[1];
+	ctx->ihv1[2] = ctx->ihv[2];
+	ctx->ihv1[3] = ctx->ihv[3];
+	ctx->ihv1[4] = ctx->ihv[4];
+
+	sha1_compression_states(ctx->ihv, block, ctx->m1, ctx->states);
+
+	if (ctx->detect_coll)
+	{
+		if (ctx->ubc_check)
+		{
+			ubc_check(ctx->m1, ubc_dv_mask);
+		}
+
+		if (ubc_dv_mask[0] != 0)
+		{
+			for (i = 0; sha1_dvs[i].dvType != 0; ++i)
+			{
+				if (ubc_dv_mask[0] & ((uint32_t)(1) << sha1_dvs[i].maskb))
+				{
+					for (j = 0; j < 80; ++j)
+						ctx->m2[j] = ctx->m1[j] ^ sha1_dvs[i].dm[j];
+
+					sha1_recompression_step(sha1_dvs[i].testt, ctx->ihv2, ihvtmp, ctx->m2, ctx->states[sha1_dvs[i].testt]);
+
+					/* to verify SHA-1 collision detection code with collisions for reduced-step SHA-1 */
+					if ((0 == ((ihvtmp[0] ^ ctx->ihv[0]) | (ihvtmp[1] ^ ctx->ihv[1]) | (ihvtmp[2] ^ ctx->ihv[2]) | (ihvtmp[3] ^ ctx->ihv[3]) | (ihvtmp[4] ^ ctx->ihv[4])))
+						|| (ctx->reduced_round_coll && 0==((ctx->ihv1[0] ^ ctx->ihv2[0]) | (ctx->ihv1[1] ^ ctx->ihv2[1]) | (ctx->ihv1[2] ^ ctx->ihv2[2]) | (ctx->ihv1[3] ^ ctx->ihv2[3]) | (ctx->ihv1[4] ^ ctx->ihv2[4]))))
+					{
+						ctx->found_collision = 1;
+
+						if (ctx->safe_hash)
+						{
+							sha1_compression_W(ctx->ihv, ctx->m1);
+							sha1_compression_W(ctx->ihv, ctx->m1);
+						}
+
+						break;
+					}
+				}
+			}
+		}
+	}
+}
+
+void SHA1DCInit(SHA1_CTX* ctx)
+{
+	ctx->total = 0;
+	ctx->ihv[0] = 0x67452301;
+	ctx->ihv[1] = 0xEFCDAB89;
+	ctx->ihv[2] = 0x98BADCFE;
+	ctx->ihv[3] = 0x10325476;
+	ctx->ihv[4] = 0xC3D2E1F0;
+	ctx->found_collision = 0;
+	ctx->safe_hash = SHA1DC_INIT_SAFE_HASH_DEFAULT;
+	ctx->ubc_check = 1;
+	ctx->detect_coll = 1;
+	ctx->reduced_round_coll = 0;
+	ctx->callback = NULL;
+}
+
+void SHA1DCSetSafeHash(SHA1_CTX* ctx, int safehash)
+{
+	if (safehash)
+		ctx->safe_hash = 1;
+	else
+		ctx->safe_hash = 0;
+}
+
+
+void SHA1DCSetUseUBC(SHA1_CTX* ctx, int ubc_check)
+{
+	if (ubc_check)
+		ctx->ubc_check = 1;
+	else
+		ctx->ubc_check = 0;
+}
+
+void SHA1DCSetUseDetectColl(SHA1_CTX* ctx, int detect_coll)
+{
+	if (detect_coll)
+		ctx->detect_coll = 1;
+	else
+		ctx->detect_coll = 0;
+}
+
+void SHA1DCSetDetectReducedRoundCollision(SHA1_CTX* ctx, int reduced_round_coll)
+{
+	if (reduced_round_coll)
+		ctx->reduced_round_coll = 1;
+	else
+		ctx->reduced_round_coll = 0;
+}
+
+void SHA1DCSetCallback(SHA1_CTX* ctx, collision_block_callback callback)
+{
+	ctx->callback = callback;
+}
+
+void SHA1DCUpdate(SHA1_CTX* ctx, const char* buf, size_t len)
+{
+	unsigned left, fill;
+
+	if (len == 0)
+		return;
+
+	left = ctx->total & 63;
+	fill = 64 - left;
+
+	if (left && len >= fill)
+	{
+		ctx->total += fill;
+		memcpy(ctx->buffer + left, buf, fill);
+		sha1_process(ctx, (uint32_t*)(ctx->buffer));
+		buf += fill;
+		len -= fill;
+		left = 0;
+	}
+	while (len >= 64)
+	{
+		ctx->total += 64;
+
+#if defined(SHA1DC_ALLOW_UNALIGNED_ACCESS)
+		sha1_process(ctx, (uint32_t*)(buf));
+#else
+		memcpy(ctx->buffer, buf, 64);
+		sha1_process(ctx, (uint32_t*)(ctx->buffer));
+#endif /* defined(SHA1DC_ALLOW_UNALIGNED_ACCESS) */
+		buf += 64;
+		len -= 64;
+	}
+	if (len > 0)
+	{
+		ctx->total += len;
+		memcpy(ctx->buffer + left, buf, len);
+	}
+}
+
+static const unsigned char sha1_padding[64] =
+{
+	0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+};
+
+int SHA1DCFinal(unsigned char output[20], SHA1_CTX *ctx)
+{
+	uint32_t last = ctx->total & 63;
+	uint32_t padn = (last < 56) ? (56 - last) : (120 - last);
+	uint64_t total;
+	SHA1DCUpdate(ctx, (const char*)(sha1_padding), padn);
+
+	total = ctx->total - padn;
+	total <<= 3;
+	ctx->buffer[56] = (unsigned char)(total >> 56);
+	ctx->buffer[57] = (unsigned char)(total >> 48);
+	ctx->buffer[58] = (unsigned char)(total >> 40);
+	ctx->buffer[59] = (unsigned char)(total >> 32);
+	ctx->buffer[60] = (unsigned char)(total >> 24);
+	ctx->buffer[61] = (unsigned char)(total >> 16);
+	ctx->buffer[62] = (unsigned char)(total >> 8);
+	ctx->buffer[63] = (unsigned char)(total);
+	sha1_process(ctx, (uint32_t*)(ctx->buffer));
+	output[0] = (unsigned char)(ctx->ihv[0] >> 24);
+	output[1] = (unsigned char)(ctx->ihv[0] >> 16);
+	output[2] = (unsigned char)(ctx->ihv[0] >> 8);
+	output[3] = (unsigned char)(ctx->ihv[0]);
+	output[4] = (unsigned char)(ctx->ihv[1] >> 24);
+	output[5] = (unsigned char)(ctx->ihv[1] >> 16);
+	output[6] = (unsigned char)(ctx->ihv[1] >> 8);
+	output[7] = (unsigned char)(ctx->ihv[1]);
+	output[8] = (unsigned char)(ctx->ihv[2] >> 24);
+	output[9] = (unsigned char)(ctx->ihv[2] >> 16);
+	output[10] = (unsigned char)(ctx->ihv[2] >> 8);
+	output[11] = (unsigned char)(ctx->ihv[2]);
+	output[12] = (unsigned char)(ctx->ihv[3] >> 24);
+	output[13] = (unsigned char)(ctx->ihv[3] >> 16);
+	output[14] = (unsigned char)(ctx->ihv[3] >> 8);
+	output[15] = (unsigned char)(ctx->ihv[3]);
+	output[16] = (unsigned char)(ctx->ihv[4] >> 24);
+	output[17] = (unsigned char)(ctx->ihv[4] >> 16);
+	output[18] = (unsigned char)(ctx->ihv[4] >> 8);
+	output[19] = (unsigned char)(ctx->ihv[4]);
+	return ctx->found_collision;
+}
+
+#ifdef SHA1DC_CUSTOM_TRAILING_INCLUDE_SHA1_C
+#include SHA1DC_CUSTOM_TRAILING_INCLUDE_SHA1_C
+#endif

vendor/libgit2-sys/libgit2/src/hash/sha1dc/sha1.h

diff --git a/vendor/libgit2-sys/libgit2/src/hash/sha1dc/sha1.h b/vendor/libgit2-sys/libgit2/src/hash/sha1dc/sha1.h
new file mode 100644
index 0000000..1e4e94b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/hash/sha1dc/sha1.h
@@ -0,0 +1,110 @@
+/***
+* Copyright 2017 Marc Stevens <marc@marc-stevens.nl>, Dan Shumow <danshu@microsoft.com>
+* Distributed under the MIT Software License.
+* See accompanying file LICENSE.txt or copy at
+* https://opensource.org/licenses/MIT
+***/
+
+#ifndef SHA1DC_SHA1_H
+#define SHA1DC_SHA1_H
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+#ifndef SHA1DC_NO_STANDARD_INCLUDES
+#include <stdint.h>
+#endif
+
+/* sha-1 compression function that takes an already expanded message, and additionally store intermediate states */
+/* only stores states ii (the state between step ii-1 and step ii) when DOSTORESTATEii is defined in ubc_check.h */
+void sha1_compression_states(uint32_t[5], const uint32_t[16], uint32_t[80], uint32_t[80][5]);
+
+/*
+// Function type for sha1_recompression_step_T (uint32_t ihvin[5], uint32_t ihvout[5], const uint32_t me2[80], const uint32_t state[5]).
+// Where 0 <= T < 80
+//       me2 is an expanded message (the expansion of an original message block XOR'ed with a disturbance vector's message block difference.)
+//       state is the internal state (a,b,c,d,e) before step T of the SHA-1 compression function while processing the original message block.
+// The function will return:
+//       ihvin: The reconstructed input chaining value.
+//       ihvout: The reconstructed output chaining value.
+*/
+typedef void(*sha1_recompression_type)(uint32_t*, uint32_t*, const uint32_t*, const uint32_t*);
+
+/* A callback function type that can be set to be called when a collision block has been found: */
+/* void collision_block_callback(uint64_t byteoffset, const uint32_t ihvin1[5], const uint32_t ihvin2[5], const uint32_t m1[80], const uint32_t m2[80]) */
+typedef void(*collision_block_callback)(uint64_t, const uint32_t*, const uint32_t*, const uint32_t*, const uint32_t*);
+
+/* The SHA-1 context. */
+typedef struct {
+	uint64_t total;
+	uint32_t ihv[5];
+	unsigned char buffer[64];
+	int found_collision;
+	int safe_hash;
+	int detect_coll;
+	int ubc_check;
+	int reduced_round_coll;
+	collision_block_callback callback;
+
+	uint32_t ihv1[5];
+	uint32_t ihv2[5];
+	uint32_t m1[80];
+	uint32_t m2[80];
+	uint32_t states[80][5];
+} SHA1_CTX;
+
+/* Initialize SHA-1 context. */
+void SHA1DCInit(SHA1_CTX*);
+
+/*
+    Function to enable safe SHA-1 hashing:
+    Collision attacks are thwarted by hashing a detected near-collision block 3 times.
+    Think of it as extending SHA-1 from 80-steps to 240-steps for such blocks:
+        The best collision attacks against SHA-1 have complexity about 2^60,
+        thus for 240-steps an immediate lower-bound for the best cryptanalytic attacks would be 2^180.
+        An attacker would be better off using a generic birthday search of complexity 2^80.
+
+   Enabling safe SHA-1 hashing will result in the correct SHA-1 hash for messages where no collision attack was detected,
+   but it will result in a different SHA-1 hash for messages where a collision attack was detected.
+   This will automatically invalidate SHA-1 based digital signature forgeries.
+   Enabled by default.
+*/
+void SHA1DCSetSafeHash(SHA1_CTX*, int);
+
+/*
+    Function to disable or enable the use of Unavoidable Bitconditions (provides a significant speed up).
+    Enabled by default
+ */
+void SHA1DCSetUseUBC(SHA1_CTX*, int);
+
+/*
+    Function to disable or enable the use of Collision Detection.
+    Enabled by default.
+ */
+void SHA1DCSetUseDetectColl(SHA1_CTX*, int);
+
+/* function to disable or enable the detection of reduced-round SHA-1 collisions */
+/* disabled by default */
+void SHA1DCSetDetectReducedRoundCollision(SHA1_CTX*, int);
+
+/* function to set a callback function, pass NULL to disable */
+/* by default no callback set */
+void SHA1DCSetCallback(SHA1_CTX*, collision_block_callback);
+
+/* update SHA-1 context with buffer contents */
+void SHA1DCUpdate(SHA1_CTX*, const char*, size_t);
+
+/* obtain SHA-1 hash from SHA-1 context */
+/* returns: 0 = no collision detected, otherwise = collision found => warn user for active attack */
+int  SHA1DCFinal(unsigned char[20], SHA1_CTX*);
+
+#if defined(__cplusplus)
+}
+#endif
+
+#ifdef SHA1DC_CUSTOM_TRAILING_INCLUDE_SHA1_H
+#include SHA1DC_CUSTOM_TRAILING_INCLUDE_SHA1_H
+#endif
+
+#endif

vendor/libgit2-sys/libgit2/src/hash/sha1dc/ubc_check.c

diff --git a/vendor/libgit2-sys/libgit2/src/hash/sha1dc/ubc_check.c b/vendor/libgit2-sys/libgit2/src/hash/sha1dc/ubc_check.c
new file mode 100644
index 0000000..b3beff2
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/hash/sha1dc/ubc_check.c
@@ -0,0 +1,372 @@
+/***
+* Copyright 2017 Marc Stevens <marc@marc-stevens.nl>, Dan Shumow <danshu@microsoft.com>
+* Distributed under the MIT Software License.
+* See accompanying file LICENSE.txt or copy at
+* https://opensource.org/licenses/MIT
+***/
+
+/*
+// this file was generated by the 'parse_bitrel' program in the tools section
+// using the data files from directory 'tools/data/3565'
+//
+// sha1_dvs contains a list of SHA-1 Disturbance Vectors (DV) to check
+// dvType, dvK and dvB define the DV: I(K,B) or II(K,B) (see the paper)
+// dm[80] is the expanded message block XOR-difference defined by the DV
+// testt is the step to do the recompression from for collision detection
+// maski and maskb define the bit to check for each DV in the dvmask returned by ubc_check
+//
+// ubc_check takes as input an expanded message block and verifies the unavoidable bitconditions for all listed DVs
+// it returns a dvmask where each bit belonging to a DV is set if all unavoidable bitconditions for that DV have been met
+// thus one needs to do the recompression check for each DV that has its bit set
+//
+// ubc_check is programmatically generated and the unavoidable bitconditions have been hardcoded
+// a directly verifiable version named ubc_check_verify can be found in ubc_check_verify.c
+// ubc_check has been verified against ubc_check_verify using the 'ubc_check_test' program in the tools section
+*/
+
+#ifndef SHA1DC_NO_STANDARD_INCLUDES
+#include <stdint.h>
+#endif
+#ifdef SHA1DC_CUSTOM_INCLUDE_UBC_CHECK_C
+#include SHA1DC_CUSTOM_INCLUDE_UBC_CHECK_C
+#endif
+#include "ubc_check.h"
+
+static const uint32_t DV_I_43_0_bit 	= (uint32_t)(1) << 0;
+static const uint32_t DV_I_44_0_bit 	= (uint32_t)(1) << 1;
+static const uint32_t DV_I_45_0_bit 	= (uint32_t)(1) << 2;
+static const uint32_t DV_I_46_0_bit 	= (uint32_t)(1) << 3;
+static const uint32_t DV_I_46_2_bit 	= (uint32_t)(1) << 4;
+static const uint32_t DV_I_47_0_bit 	= (uint32_t)(1) << 5;
+static const uint32_t DV_I_47_2_bit 	= (uint32_t)(1) << 6;
+static const uint32_t DV_I_48_0_bit 	= (uint32_t)(1) << 7;
+static const uint32_t DV_I_48_2_bit 	= (uint32_t)(1) << 8;
+static const uint32_t DV_I_49_0_bit 	= (uint32_t)(1) << 9;
+static const uint32_t DV_I_49_2_bit 	= (uint32_t)(1) << 10;
+static const uint32_t DV_I_50_0_bit 	= (uint32_t)(1) << 11;
+static const uint32_t DV_I_50_2_bit 	= (uint32_t)(1) << 12;
+static const uint32_t DV_I_51_0_bit 	= (uint32_t)(1) << 13;
+static const uint32_t DV_I_51_2_bit 	= (uint32_t)(1) << 14;
+static const uint32_t DV_I_52_0_bit 	= (uint32_t)(1) << 15;
+static const uint32_t DV_II_45_0_bit 	= (uint32_t)(1) << 16;
+static const uint32_t DV_II_46_0_bit 	= (uint32_t)(1) << 17;
+static const uint32_t DV_II_46_2_bit 	= (uint32_t)(1) << 18;
+static const uint32_t DV_II_47_0_bit 	= (uint32_t)(1) << 19;
+static const uint32_t DV_II_48_0_bit 	= (uint32_t)(1) << 20;
+static const uint32_t DV_II_49_0_bit 	= (uint32_t)(1) << 21;
+static const uint32_t DV_II_49_2_bit 	= (uint32_t)(1) << 22;
+static const uint32_t DV_II_50_0_bit 	= (uint32_t)(1) << 23;
+static const uint32_t DV_II_50_2_bit 	= (uint32_t)(1) << 24;
+static const uint32_t DV_II_51_0_bit 	= (uint32_t)(1) << 25;
+static const uint32_t DV_II_51_2_bit 	= (uint32_t)(1) << 26;
+static const uint32_t DV_II_52_0_bit 	= (uint32_t)(1) << 27;
+static const uint32_t DV_II_53_0_bit 	= (uint32_t)(1) << 28;
+static const uint32_t DV_II_54_0_bit 	= (uint32_t)(1) << 29;
+static const uint32_t DV_II_55_0_bit 	= (uint32_t)(1) << 30;
+static const uint32_t DV_II_56_0_bit 	= (uint32_t)(1) << 31;
+
+dv_info_t sha1_dvs[] =
+{
+  {1,43,0,58,0,0, { 0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012,0x80000202,0x00000018,0x00000164,0x00000408,0x800000e6,0x8000004c,0x00000803,0x80000161,0x80000599 } }
+, {1,44,0,58,0,1, { 0xb4000008,0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012,0x80000202,0x00000018,0x00000164,0x00000408,0x800000e6,0x8000004c,0x00000803,0x80000161 } }
+, {1,45,0,58,0,2, { 0xf4000014,0xb4000008,0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012,0x80000202,0x00000018,0x00000164,0x00000408,0x800000e6,0x8000004c,0x00000803 } }
+, {1,46,0,58,0,3, { 0x2c000010,0xf4000014,0xb4000008,0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012,0x80000202,0x00000018,0x00000164,0x00000408,0x800000e6,0x8000004c } }
+, {1,46,2,58,0,4, { 0xb0000040,0xd0000053,0xd0000022,0x20000000,0x60000032,0x60000043,0x20000040,0xe0000042,0x60000002,0x80000001,0x00000020,0x00000003,0x40000052,0x40000040,0xe0000052,0xa0000000,0x80000040,0x20000001,0x20000060,0x80000001,0x40000042,0xc0000043,0x40000022,0x00000003,0x40000042,0xc0000043,0xc0000022,0x00000001,0x40000002,0xc0000043,0x40000062,0x80000001,0x40000042,0x40000042,0x40000002,0x00000002,0x00000040,0x80000002,0x80000000,0x80000002,0x80000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000000,0x00000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000101,0x00000009,0x00000012,0x00000202,0x0000001a,0x00000124,0x0000040c,0x00000026,0x0000004a,0x0000080a,0x00000060,0x00000590,0x00001020,0x0000039a,0x00000132 } }
+, {1,47,0,58,0,5, { 0xc8000010,0x2c000010,0xf4000014,0xb4000008,0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012,0x80000202,0x00000018,0x00000164,0x00000408,0x800000e6 } }
+, {1,47,2,58,0,6, { 0x20000043,0xb0000040,0xd0000053,0xd0000022,0x20000000,0x60000032,0x60000043,0x20000040,0xe0000042,0x60000002,0x80000001,0x00000020,0x00000003,0x40000052,0x40000040,0xe0000052,0xa0000000,0x80000040,0x20000001,0x20000060,0x80000001,0x40000042,0xc0000043,0x40000022,0x00000003,0x40000042,0xc0000043,0xc0000022,0x00000001,0x40000002,0xc0000043,0x40000062,0x80000001,0x40000042,0x40000042,0x40000002,0x00000002,0x00000040,0x80000002,0x80000000,0x80000002,0x80000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000000,0x00000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000101,0x00000009,0x00000012,0x00000202,0x0000001a,0x00000124,0x0000040c,0x00000026,0x0000004a,0x0000080a,0x00000060,0x00000590,0x00001020,0x0000039a } }
+, {1,48,0,58,0,7, { 0xb800000a,0xc8000010,0x2c000010,0xf4000014,0xb4000008,0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012,0x80000202,0x00000018,0x00000164,0x00000408 } }
+, {1,48,2,58,0,8, { 0xe000002a,0x20000043,0xb0000040,0xd0000053,0xd0000022,0x20000000,0x60000032,0x60000043,0x20000040,0xe0000042,0x60000002,0x80000001,0x00000020,0x00000003,0x40000052,0x40000040,0xe0000052,0xa0000000,0x80000040,0x20000001,0x20000060,0x80000001,0x40000042,0xc0000043,0x40000022,0x00000003,0x40000042,0xc0000043,0xc0000022,0x00000001,0x40000002,0xc0000043,0x40000062,0x80000001,0x40000042,0x40000042,0x40000002,0x00000002,0x00000040,0x80000002,0x80000000,0x80000002,0x80000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000000,0x00000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000101,0x00000009,0x00000012,0x00000202,0x0000001a,0x00000124,0x0000040c,0x00000026,0x0000004a,0x0000080a,0x00000060,0x00000590,0x00001020 } }
+, {1,49,0,58,0,9, { 0x18000000,0xb800000a,0xc8000010,0x2c000010,0xf4000014,0xb4000008,0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012,0x80000202,0x00000018,0x00000164 } }
+, {1,49,2,58,0,10, { 0x60000000,0xe000002a,0x20000043,0xb0000040,0xd0000053,0xd0000022,0x20000000,0x60000032,0x60000043,0x20000040,0xe0000042,0x60000002,0x80000001,0x00000020,0x00000003,0x40000052,0x40000040,0xe0000052,0xa0000000,0x80000040,0x20000001,0x20000060,0x80000001,0x40000042,0xc0000043,0x40000022,0x00000003,0x40000042,0xc0000043,0xc0000022,0x00000001,0x40000002,0xc0000043,0x40000062,0x80000001,0x40000042,0x40000042,0x40000002,0x00000002,0x00000040,0x80000002,0x80000000,0x80000002,0x80000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000000,0x00000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000101,0x00000009,0x00000012,0x00000202,0x0000001a,0x00000124,0x0000040c,0x00000026,0x0000004a,0x0000080a,0x00000060,0x00000590 } }
+, {1,50,0,65,0,11, { 0x0800000c,0x18000000,0xb800000a,0xc8000010,0x2c000010,0xf4000014,0xb4000008,0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012,0x80000202,0x00000018 } }
+, {1,50,2,65,0,12, { 0x20000030,0x60000000,0xe000002a,0x20000043,0xb0000040,0xd0000053,0xd0000022,0x20000000,0x60000032,0x60000043,0x20000040,0xe0000042,0x60000002,0x80000001,0x00000020,0x00000003,0x40000052,0x40000040,0xe0000052,0xa0000000,0x80000040,0x20000001,0x20000060,0x80000001,0x40000042,0xc0000043,0x40000022,0x00000003,0x40000042,0xc0000043,0xc0000022,0x00000001,0x40000002,0xc0000043,0x40000062,0x80000001,0x40000042,0x40000042,0x40000002,0x00000002,0x00000040,0x80000002,0x80000000,0x80000002,0x80000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000000,0x00000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000101,0x00000009,0x00000012,0x00000202,0x0000001a,0x00000124,0x0000040c,0x00000026,0x0000004a,0x0000080a,0x00000060 } }
+, {1,51,0,65,0,13, { 0xe8000000,0x0800000c,0x18000000,0xb800000a,0xc8000010,0x2c000010,0xf4000014,0xb4000008,0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012,0x80000202 } }
+, {1,51,2,65,0,14, { 0xa0000003,0x20000030,0x60000000,0xe000002a,0x20000043,0xb0000040,0xd0000053,0xd0000022,0x20000000,0x60000032,0x60000043,0x20000040,0xe0000042,0x60000002,0x80000001,0x00000020,0x00000003,0x40000052,0x40000040,0xe0000052,0xa0000000,0x80000040,0x20000001,0x20000060,0x80000001,0x40000042,0xc0000043,0x40000022,0x00000003,0x40000042,0xc0000043,0xc0000022,0x00000001,0x40000002,0xc0000043,0x40000062,0x80000001,0x40000042,0x40000042,0x40000002,0x00000002,0x00000040,0x80000002,0x80000000,0x80000002,0x80000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000000,0x00000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000101,0x00000009,0x00000012,0x00000202,0x0000001a,0x00000124,0x0000040c,0x00000026,0x0000004a,0x0000080a } }
+, {1,52,0,65,0,15, { 0x04000010,0xe8000000,0x0800000c,0x18000000,0xb800000a,0xc8000010,0x2c000010,0xf4000014,0xb4000008,0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012 } }
+, {2,45,0,58,0,16, { 0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107,0x00000089,0x00000014,0x8000024b,0x0000011b,0x8000016d,0x8000041a,0x000002e4,0x80000054,0x00000967 } }
+, {2,46,0,58,0,17, { 0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107,0x00000089,0x00000014,0x8000024b,0x0000011b,0x8000016d,0x8000041a,0x000002e4,0x80000054 } }
+, {2,46,2,58,0,18, { 0x90000070,0xb0000053,0x30000008,0x00000043,0xd0000072,0xb0000010,0xf0000062,0xc0000042,0x00000030,0xe0000042,0x20000060,0xe0000041,0x20000050,0xc0000041,0xe0000072,0xa0000003,0xc0000012,0x60000041,0xc0000032,0x20000001,0xc0000002,0xe0000042,0x60000042,0x80000002,0x00000000,0x00000000,0x80000000,0x00000002,0x00000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000001,0x00000060,0x80000003,0x40000002,0xc0000040,0xc0000002,0x80000000,0x80000000,0x80000002,0x00000040,0x00000002,0x80000000,0x80000000,0x80000000,0x00000002,0x00000040,0x00000000,0x80000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000105,0x00000089,0x00000016,0x0000020b,0x0000011b,0x0000012d,0x0000041e,0x00000224,0x00000050,0x0000092e,0x0000046c,0x000005b6,0x0000106a,0x00000b90,0x00000152 } }
+, {2,47,0,58,0,19, { 0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107,0x00000089,0x00000014,0x8000024b,0x0000011b,0x8000016d,0x8000041a,0x000002e4 } }
+, {2,48,0,58,0,20, { 0xbc00001a,0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107,0x00000089,0x00000014,0x8000024b,0x0000011b,0x8000016d,0x8000041a } }
+, {2,49,0,58,0,21, { 0x3c000004,0xbc00001a,0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107,0x00000089,0x00000014,0x8000024b,0x0000011b,0x8000016d } }
+, {2,49,2,58,0,22, { 0xf0000010,0xf000006a,0x80000040,0x90000070,0xb0000053,0x30000008,0x00000043,0xd0000072,0xb0000010,0xf0000062,0xc0000042,0x00000030,0xe0000042,0x20000060,0xe0000041,0x20000050,0xc0000041,0xe0000072,0xa0000003,0xc0000012,0x60000041,0xc0000032,0x20000001,0xc0000002,0xe0000042,0x60000042,0x80000002,0x00000000,0x00000000,0x80000000,0x00000002,0x00000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000001,0x00000060,0x80000003,0x40000002,0xc0000040,0xc0000002,0x80000000,0x80000000,0x80000002,0x00000040,0x00000002,0x80000000,0x80000000,0x80000000,0x00000002,0x00000040,0x00000000,0x80000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000105,0x00000089,0x00000016,0x0000020b,0x0000011b,0x0000012d,0x0000041e,0x00000224,0x00000050,0x0000092e,0x0000046c,0x000005b6 } }
+, {2,50,0,65,0,23, { 0xb400001c,0x3c000004,0xbc00001a,0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107,0x00000089,0x00000014,0x8000024b,0x0000011b } }
+, {2,50,2,65,0,24, { 0xd0000072,0xf0000010,0xf000006a,0x80000040,0x90000070,0xb0000053,0x30000008,0x00000043,0xd0000072,0xb0000010,0xf0000062,0xc0000042,0x00000030,0xe0000042,0x20000060,0xe0000041,0x20000050,0xc0000041,0xe0000072,0xa0000003,0xc0000012,0x60000041,0xc0000032,0x20000001,0xc0000002,0xe0000042,0x60000042,0x80000002,0x00000000,0x00000000,0x80000000,0x00000002,0x00000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000001,0x00000060,0x80000003,0x40000002,0xc0000040,0xc0000002,0x80000000,0x80000000,0x80000002,0x00000040,0x00000002,0x80000000,0x80000000,0x80000000,0x00000002,0x00000040,0x00000000,0x80000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000105,0x00000089,0x00000016,0x0000020b,0x0000011b,0x0000012d,0x0000041e,0x00000224,0x00000050,0x0000092e,0x0000046c } }
+, {2,51,0,65,0,25, { 0xc0000010,0xb400001c,0x3c000004,0xbc00001a,0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107,0x00000089,0x00000014,0x8000024b } }
+, {2,51,2,65,0,26, { 0x00000043,0xd0000072,0xf0000010,0xf000006a,0x80000040,0x90000070,0xb0000053,0x30000008,0x00000043,0xd0000072,0xb0000010,0xf0000062,0xc0000042,0x00000030,0xe0000042,0x20000060,0xe0000041,0x20000050,0xc0000041,0xe0000072,0xa0000003,0xc0000012,0x60000041,0xc0000032,0x20000001,0xc0000002,0xe0000042,0x60000042,0x80000002,0x00000000,0x00000000,0x80000000,0x00000002,0x00000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000001,0x00000060,0x80000003,0x40000002,0xc0000040,0xc0000002,0x80000000,0x80000000,0x80000002,0x00000040,0x00000002,0x80000000,0x80000000,0x80000000,0x00000002,0x00000040,0x00000000,0x80000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000105,0x00000089,0x00000016,0x0000020b,0x0000011b,0x0000012d,0x0000041e,0x00000224,0x00000050,0x0000092e } }
+, {2,52,0,65,0,27, { 0x0c000002,0xc0000010,0xb400001c,0x3c000004,0xbc00001a,0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107,0x00000089,0x00000014 } }
+, {2,53,0,65,0,28, { 0xcc000014,0x0c000002,0xc0000010,0xb400001c,0x3c000004,0xbc00001a,0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107,0x00000089 } }
+, {2,54,0,65,0,29, { 0x0400001c,0xcc000014,0x0c000002,0xc0000010,0xb400001c,0x3c000004,0xbc00001a,0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107 } }
+, {2,55,0,65,0,30, { 0x00000010,0x0400001c,0xcc000014,0x0c000002,0xc0000010,0xb400001c,0x3c000004,0xbc00001a,0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b } }
+, {2,56,0,65,0,31, { 0x2600001a,0x00000010,0x0400001c,0xcc000014,0x0c000002,0xc0000010,0xb400001c,0x3c000004,0xbc00001a,0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046 } }
+, {0,0,0,0,0,0, {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}}
+};
+void ubc_check(const uint32_t W[80], uint32_t dvmask[1])
+{
+	uint32_t mask = ~((uint32_t)(0));
+	mask &= (((((W[44]^W[45])>>29)&1)-1) | ~(DV_I_48_0_bit|DV_I_51_0_bit|DV_I_52_0_bit|DV_II_45_0_bit|DV_II_46_0_bit|DV_II_50_0_bit|DV_II_51_0_bit));
+	mask &= (((((W[49]^W[50])>>29)&1)-1) | ~(DV_I_46_0_bit|DV_II_45_0_bit|DV_II_50_0_bit|DV_II_51_0_bit|DV_II_55_0_bit|DV_II_56_0_bit));
+	mask &= (((((W[48]^W[49])>>29)&1)-1) | ~(DV_I_45_0_bit|DV_I_52_0_bit|DV_II_49_0_bit|DV_II_50_0_bit|DV_II_54_0_bit|DV_II_55_0_bit));
+	mask &= ((((W[47]^(W[50]>>25))&(1<<4))-(1<<4)) | ~(DV_I_47_0_bit|DV_I_49_0_bit|DV_I_51_0_bit|DV_II_45_0_bit|DV_II_51_0_bit|DV_II_56_0_bit));
+	mask &= (((((W[47]^W[48])>>29)&1)-1) | ~(DV_I_44_0_bit|DV_I_51_0_bit|DV_II_48_0_bit|DV_II_49_0_bit|DV_II_53_0_bit|DV_II_54_0_bit));
+	mask &= (((((W[46]>>4)^(W[49]>>29))&1)-1) | ~(DV_I_46_0_bit|DV_I_48_0_bit|DV_I_50_0_bit|DV_I_52_0_bit|DV_II_50_0_bit|DV_II_55_0_bit));
+	mask &= (((((W[46]^W[47])>>29)&1)-1) | ~(DV_I_43_0_bit|DV_I_50_0_bit|DV_II_47_0_bit|DV_II_48_0_bit|DV_II_52_0_bit|DV_II_53_0_bit));
+	mask &= (((((W[45]>>4)^(W[48]>>29))&1)-1) | ~(DV_I_45_0_bit|DV_I_47_0_bit|DV_I_49_0_bit|DV_I_51_0_bit|DV_II_49_0_bit|DV_II_54_0_bit));
+	mask &= (((((W[45]^W[46])>>29)&1)-1) | ~(DV_I_49_0_bit|DV_I_52_0_bit|DV_II_46_0_bit|DV_II_47_0_bit|DV_II_51_0_bit|DV_II_52_0_bit));
+	mask &= (((((W[44]>>4)^(W[47]>>29))&1)-1) | ~(DV_I_44_0_bit|DV_I_46_0_bit|DV_I_48_0_bit|DV_I_50_0_bit|DV_II_48_0_bit|DV_II_53_0_bit));
+	mask &= (((((W[43]>>4)^(W[46]>>29))&1)-1) | ~(DV_I_43_0_bit|DV_I_45_0_bit|DV_I_47_0_bit|DV_I_49_0_bit|DV_II_47_0_bit|DV_II_52_0_bit));
+	mask &= (((((W[43]^W[44])>>29)&1)-1) | ~(DV_I_47_0_bit|DV_I_50_0_bit|DV_I_51_0_bit|DV_II_45_0_bit|DV_II_49_0_bit|DV_II_50_0_bit));
+	mask &= (((((W[42]>>4)^(W[45]>>29))&1)-1) | ~(DV_I_44_0_bit|DV_I_46_0_bit|DV_I_48_0_bit|DV_I_52_0_bit|DV_II_46_0_bit|DV_II_51_0_bit));
+	mask &= (((((W[41]>>4)^(W[44]>>29))&1)-1) | ~(DV_I_43_0_bit|DV_I_45_0_bit|DV_I_47_0_bit|DV_I_51_0_bit|DV_II_45_0_bit|DV_II_50_0_bit));
+	mask &= (((((W[40]^W[41])>>29)&1)-1) | ~(DV_I_44_0_bit|DV_I_47_0_bit|DV_I_48_0_bit|DV_II_46_0_bit|DV_II_47_0_bit|DV_II_56_0_bit));
+	mask &= (((((W[54]^W[55])>>29)&1)-1) | ~(DV_I_51_0_bit|DV_II_47_0_bit|DV_II_50_0_bit|DV_II_55_0_bit|DV_II_56_0_bit));
+	mask &= (((((W[53]^W[54])>>29)&1)-1) | ~(DV_I_50_0_bit|DV_II_46_0_bit|DV_II_49_0_bit|DV_II_54_0_bit|DV_II_55_0_bit));
+	mask &= (((((W[52]^W[53])>>29)&1)-1) | ~(DV_I_49_0_bit|DV_II_45_0_bit|DV_II_48_0_bit|DV_II_53_0_bit|DV_II_54_0_bit));
+	mask &= ((((W[50]^(W[53]>>25))&(1<<4))-(1<<4)) | ~(DV_I_50_0_bit|DV_I_52_0_bit|DV_II_46_0_bit|DV_II_48_0_bit|DV_II_54_0_bit));
+	mask &= (((((W[50]^W[51])>>29)&1)-1) | ~(DV_I_47_0_bit|DV_II_46_0_bit|DV_II_51_0_bit|DV_II_52_0_bit|DV_II_56_0_bit));
+	mask &= ((((W[49]^(W[52]>>25))&(1<<4))-(1<<4)) | ~(DV_I_49_0_bit|DV_I_51_0_bit|DV_II_45_0_bit|DV_II_47_0_bit|DV_II_53_0_bit));
+	mask &= ((((W[48]^(W[51]>>25))&(1<<4))-(1<<4)) | ~(DV_I_48_0_bit|DV_I_50_0_bit|DV_I_52_0_bit|DV_II_46_0_bit|DV_II_52_0_bit));
+	mask &= (((((W[42]^W[43])>>29)&1)-1) | ~(DV_I_46_0_bit|DV_I_49_0_bit|DV_I_50_0_bit|DV_II_48_0_bit|DV_II_49_0_bit));
+	mask &= (((((W[41]^W[42])>>29)&1)-1) | ~(DV_I_45_0_bit|DV_I_48_0_bit|DV_I_49_0_bit|DV_II_47_0_bit|DV_II_48_0_bit));
+	mask &= (((((W[40]>>4)^(W[43]>>29))&1)-1) | ~(DV_I_44_0_bit|DV_I_46_0_bit|DV_I_50_0_bit|DV_II_49_0_bit|DV_II_56_0_bit));
+	mask &= (((((W[39]>>4)^(W[42]>>29))&1)-1) | ~(DV_I_43_0_bit|DV_I_45_0_bit|DV_I_49_0_bit|DV_II_48_0_bit|DV_II_55_0_bit));
+	if (mask & (DV_I_44_0_bit|DV_I_48_0_bit|DV_II_47_0_bit|DV_II_54_0_bit|DV_II_56_0_bit))
+		mask &= (((((W[38]>>4)^(W[41]>>29))&1)-1) | ~(DV_I_44_0_bit|DV_I_48_0_bit|DV_II_47_0_bit|DV_II_54_0_bit|DV_II_56_0_bit));
+	mask &= (((((W[37]>>4)^(W[40]>>29))&1)-1) | ~(DV_I_43_0_bit|DV_I_47_0_bit|DV_II_46_0_bit|DV_II_53_0_bit|DV_II_55_0_bit));
+	if (mask & (DV_I_52_0_bit|DV_II_48_0_bit|DV_II_51_0_bit|DV_II_56_0_bit))
+		mask &= (((((W[55]^W[56])>>29)&1)-1) | ~(DV_I_52_0_bit|DV_II_48_0_bit|DV_II_51_0_bit|DV_II_56_0_bit));
+	if (mask & (DV_I_52_0_bit|DV_II_48_0_bit|DV_II_50_0_bit|DV_II_56_0_bit))
+		mask &= ((((W[52]^(W[55]>>25))&(1<<4))-(1<<4)) | ~(DV_I_52_0_bit|DV_II_48_0_bit|DV_II_50_0_bit|DV_II_56_0_bit));
+	if (mask & (DV_I_51_0_bit|DV_II_47_0_bit|DV_II_49_0_bit|DV_II_55_0_bit))
+		mask &= ((((W[51]^(W[54]>>25))&(1<<4))-(1<<4)) | ~(DV_I_51_0_bit|DV_II_47_0_bit|DV_II_49_0_bit|DV_II_55_0_bit));
+	if (mask & (DV_I_48_0_bit|DV_II_47_0_bit|DV_II_52_0_bit|DV_II_53_0_bit))
+		mask &= (((((W[51]^W[52])>>29)&1)-1) | ~(DV_I_48_0_bit|DV_II_47_0_bit|DV_II_52_0_bit|DV_II_53_0_bit));
+	if (mask & (DV_I_46_0_bit|DV_I_49_0_bit|DV_II_45_0_bit|DV_II_48_0_bit))
+		mask &= (((((W[36]>>4)^(W[40]>>29))&1)-1) | ~(DV_I_46_0_bit|DV_I_49_0_bit|DV_II_45_0_bit|DV_II_48_0_bit));
+	if (mask & (DV_I_52_0_bit|DV_II_48_0_bit|DV_II_49_0_bit))
+		mask &= ((0-(((W[53]^W[56])>>29)&1)) | ~(DV_I_52_0_bit|DV_II_48_0_bit|DV_II_49_0_bit));
+	if (mask & (DV_I_50_0_bit|DV_II_46_0_bit|DV_II_47_0_bit))
+		mask &= ((0-(((W[51]^W[54])>>29)&1)) | ~(DV_I_50_0_bit|DV_II_46_0_bit|DV_II_47_0_bit));
+	if (mask & (DV_I_49_0_bit|DV_I_51_0_bit|DV_II_45_0_bit))
+		mask &= ((0-(((W[50]^W[52])>>29)&1)) | ~(DV_I_49_0_bit|DV_I_51_0_bit|DV_II_45_0_bit));
+	if (mask & (DV_I_48_0_bit|DV_I_50_0_bit|DV_I_52_0_bit))
+		mask &= ((0-(((W[49]^W[51])>>29)&1)) | ~(DV_I_48_0_bit|DV_I_50_0_bit|DV_I_52_0_bit));
+	if (mask & (DV_I_47_0_bit|DV_I_49_0_bit|DV_I_51_0_bit))
+		mask &= ((0-(((W[48]^W[50])>>29)&1)) | ~(DV_I_47_0_bit|DV_I_49_0_bit|DV_I_51_0_bit));
+	if (mask & (DV_I_46_0_bit|DV_I_48_0_bit|DV_I_50_0_bit))
+		mask &= ((0-(((W[47]^W[49])>>29)&1)) | ~(DV_I_46_0_bit|DV_I_48_0_bit|DV_I_50_0_bit));
+	if (mask & (DV_I_45_0_bit|DV_I_47_0_bit|DV_I_49_0_bit))
+		mask &= ((0-(((W[46]^W[48])>>29)&1)) | ~(DV_I_45_0_bit|DV_I_47_0_bit|DV_I_49_0_bit));
+	mask &= ((((W[45]^W[47])&(1<<6))-(1<<6)) | ~(DV_I_47_2_bit|DV_I_49_2_bit|DV_I_51_2_bit));
+	if (mask & (DV_I_44_0_bit|DV_I_46_0_bit|DV_I_48_0_bit))
+		mask &= ((0-(((W[45]^W[47])>>29)&1)) | ~(DV_I_44_0_bit|DV_I_46_0_bit|DV_I_48_0_bit));
+	mask &= (((((W[44]^W[46])>>6)&1)-1) | ~(DV_I_46_2_bit|DV_I_48_2_bit|DV_I_50_2_bit));
+	if (mask & (DV_I_43_0_bit|DV_I_45_0_bit|DV_I_47_0_bit))
+		mask &= ((0-(((W[44]^W[46])>>29)&1)) | ~(DV_I_43_0_bit|DV_I_45_0_bit|DV_I_47_0_bit));
+	mask &= ((0-((W[41]^(W[42]>>5))&(1<<1))) | ~(DV_I_48_2_bit|DV_II_46_2_bit|DV_II_51_2_bit));
+	mask &= ((0-((W[40]^(W[41]>>5))&(1<<1))) | ~(DV_I_47_2_bit|DV_I_51_2_bit|DV_II_50_2_bit));
+	if (mask & (DV_I_44_0_bit|DV_I_46_0_bit|DV_II_56_0_bit))
+		mask &= ((0-(((W[40]^W[42])>>4)&1)) | ~(DV_I_44_0_bit|DV_I_46_0_bit|DV_II_56_0_bit));
+	mask &= ((0-((W[39]^(W[40]>>5))&(1<<1))) | ~(DV_I_46_2_bit|DV_I_50_2_bit|DV_II_49_2_bit));
+	if (mask & (DV_I_43_0_bit|DV_I_45_0_bit|DV_II_55_0_bit))
+		mask &= ((0-(((W[39]^W[41])>>4)&1)) | ~(DV_I_43_0_bit|DV_I_45_0_bit|DV_II_55_0_bit));
+	if (mask & (DV_I_44_0_bit|DV_II_54_0_bit|DV_II_56_0_bit))
+		mask &= ((0-(((W[38]^W[40])>>4)&1)) | ~(DV_I_44_0_bit|DV_II_54_0_bit|DV_II_56_0_bit));
+	if (mask & (DV_I_43_0_bit|DV_II_53_0_bit|DV_II_55_0_bit))
+		mask &= ((0-(((W[37]^W[39])>>4)&1)) | ~(DV_I_43_0_bit|DV_II_53_0_bit|DV_II_55_0_bit));
+	mask &= ((0-((W[36]^(W[37]>>5))&(1<<1))) | ~(DV_I_47_2_bit|DV_I_50_2_bit|DV_II_46_2_bit));
+	if (mask & (DV_I_45_0_bit|DV_I_48_0_bit|DV_II_47_0_bit))
+		mask &= (((((W[35]>>4)^(W[39]>>29))&1)-1) | ~(DV_I_45_0_bit|DV_I_48_0_bit|DV_II_47_0_bit));
+	if (mask & (DV_I_48_0_bit|DV_II_48_0_bit))
+		mask &= ((0-((W[63]^(W[64]>>5))&(1<<0))) | ~(DV_I_48_0_bit|DV_II_48_0_bit));
+	if (mask & (DV_I_45_0_bit|DV_II_45_0_bit))
+		mask &= ((0-((W[63]^(W[64]>>5))&(1<<1))) | ~(DV_I_45_0_bit|DV_II_45_0_bit));
+	if (mask & (DV_I_47_0_bit|DV_II_47_0_bit))
+		mask &= ((0-((W[62]^(W[63]>>5))&(1<<0))) | ~(DV_I_47_0_bit|DV_II_47_0_bit));
+	if (mask & (DV_I_46_0_bit|DV_II_46_0_bit))
+		mask &= ((0-((W[61]^(W[62]>>5))&(1<<0))) | ~(DV_I_46_0_bit|DV_II_46_0_bit));
+	mask &= ((0-((W[61]^(W[62]>>5))&(1<<2))) | ~(DV_I_46_2_bit|DV_II_46_2_bit));
+	if (mask & (DV_I_45_0_bit|DV_II_45_0_bit))
+		mask &= ((0-((W[60]^(W[61]>>5))&(1<<0))) | ~(DV_I_45_0_bit|DV_II_45_0_bit));
+	if (mask & (DV_II_51_0_bit|DV_II_54_0_bit))
+		mask &= (((((W[58]^W[59])>>29)&1)-1) | ~(DV_II_51_0_bit|DV_II_54_0_bit));
+	if (mask & (DV_II_50_0_bit|DV_II_53_0_bit))
+		mask &= (((((W[57]^W[58])>>29)&1)-1) | ~(DV_II_50_0_bit|DV_II_53_0_bit));
+	if (mask & (DV_II_52_0_bit|DV_II_54_0_bit))
+		mask &= ((((W[56]^(W[59]>>25))&(1<<4))-(1<<4)) | ~(DV_II_52_0_bit|DV_II_54_0_bit));
+	if (mask & (DV_II_51_0_bit|DV_II_52_0_bit))
+		mask &= ((0-(((W[56]^W[59])>>29)&1)) | ~(DV_II_51_0_bit|DV_II_52_0_bit));
+	if (mask & (DV_II_49_0_bit|DV_II_52_0_bit))
+		mask &= (((((W[56]^W[57])>>29)&1)-1) | ~(DV_II_49_0_bit|DV_II_52_0_bit));
+	if (mask & (DV_II_51_0_bit|DV_II_53_0_bit))
+		mask &= ((((W[55]^(W[58]>>25))&(1<<4))-(1<<4)) | ~(DV_II_51_0_bit|DV_II_53_0_bit));
+	if (mask & (DV_II_50_0_bit|DV_II_52_0_bit))
+		mask &= ((((W[54]^(W[57]>>25))&(1<<4))-(1<<4)) | ~(DV_II_50_0_bit|DV_II_52_0_bit));
+	if (mask & (DV_II_49_0_bit|DV_II_51_0_bit))
+		mask &= ((((W[53]^(W[56]>>25))&(1<<4))-(1<<4)) | ~(DV_II_49_0_bit|DV_II_51_0_bit));
+	mask &= ((((W[51]^(W[50]>>5))&(1<<1))-(1<<1)) | ~(DV_I_50_2_bit|DV_II_46_2_bit));
+	mask &= ((((W[48]^W[50])&(1<<6))-(1<<6)) | ~(DV_I_50_2_bit|DV_II_46_2_bit));
+	if (mask & (DV_I_51_0_bit|DV_I_52_0_bit))
+		mask &= ((0-(((W[48]^W[55])>>29)&1)) | ~(DV_I_51_0_bit|DV_I_52_0_bit));
+	mask &= ((((W[47]^W[49])&(1<<6))-(1<<6)) | ~(DV_I_49_2_bit|DV_I_51_2_bit));
+	mask &= ((((W[48]^(W[47]>>5))&(1<<1))-(1<<1)) | ~(DV_I_47_2_bit|DV_II_51_2_bit));
+	mask &= ((((W[46]^W[48])&(1<<6))-(1<<6)) | ~(DV_I_48_2_bit|DV_I_50_2_bit));
+	mask &= ((((W[47]^(W[46]>>5))&(1<<1))-(1<<1)) | ~(DV_I_46_2_bit|DV_II_50_2_bit));
+	mask &= ((0-((W[44]^(W[45]>>5))&(1<<1))) | ~(DV_I_51_2_bit|DV_II_49_2_bit));
+	mask &= ((((W[43]^W[45])&(1<<6))-(1<<6)) | ~(DV_I_47_2_bit|DV_I_49_2_bit));
+	mask &= (((((W[42]^W[44])>>6)&1)-1) | ~(DV_I_46_2_bit|DV_I_48_2_bit));
+	mask &= ((((W[43]^(W[42]>>5))&(1<<1))-(1<<1)) | ~(DV_II_46_2_bit|DV_II_51_2_bit));
+	mask &= ((((W[42]^(W[41]>>5))&(1<<1))-(1<<1)) | ~(DV_I_51_2_bit|DV_II_50_2_bit));
+	mask &= ((((W[41]^(W[40]>>5))&(1<<1))-(1<<1)) | ~(DV_I_50_2_bit|DV_II_49_2_bit));
+	if (mask & (DV_I_52_0_bit|DV_II_51_0_bit))
+		mask &= ((((W[39]^(W[43]>>25))&(1<<4))-(1<<4)) | ~(DV_I_52_0_bit|DV_II_51_0_bit));
+	if (mask & (DV_I_51_0_bit|DV_II_50_0_bit))
+		mask &= ((((W[38]^(W[42]>>25))&(1<<4))-(1<<4)) | ~(DV_I_51_0_bit|DV_II_50_0_bit));
+	if (mask & (DV_I_48_2_bit|DV_I_51_2_bit))
+		mask &= ((0-((W[37]^(W[38]>>5))&(1<<1))) | ~(DV_I_48_2_bit|DV_I_51_2_bit));
+	if (mask & (DV_I_50_0_bit|DV_II_49_0_bit))
+		mask &= ((((W[37]^(W[41]>>25))&(1<<4))-(1<<4)) | ~(DV_I_50_0_bit|DV_II_49_0_bit));
+	if (mask & (DV_II_52_0_bit|DV_II_54_0_bit))
+		mask &= ((0-((W[36]^W[38])&(1<<4))) | ~(DV_II_52_0_bit|DV_II_54_0_bit));
+	mask &= ((0-((W[35]^(W[36]>>5))&(1<<1))) | ~(DV_I_46_2_bit|DV_I_49_2_bit));
+	if (mask & (DV_I_51_0_bit|DV_II_47_0_bit))
+		mask &= ((((W[35]^(W[39]>>25))&(1<<3))-(1<<3)) | ~(DV_I_51_0_bit|DV_II_47_0_bit));
+if (mask) {
+
+	if (mask & DV_I_43_0_bit)
+		 if (
+			    !((W[61]^(W[62]>>5)) & (1<<1))
+			 || !(!((W[59]^(W[63]>>25)) & (1<<5)))
+			 || !((W[58]^(W[63]>>30)) & (1<<0))
+		 )  mask &= ~DV_I_43_0_bit;
+	if (mask & DV_I_44_0_bit)
+		 if (
+			    !((W[62]^(W[63]>>5)) & (1<<1))
+			 || !(!((W[60]^(W[64]>>25)) & (1<<5)))
+			 || !((W[59]^(W[64]>>30)) & (1<<0))
+		 )  mask &= ~DV_I_44_0_bit;
+	if (mask & DV_I_46_2_bit)
+		mask &= ((~((W[40]^W[42])>>2)) | ~DV_I_46_2_bit);
+	if (mask & DV_I_47_2_bit)
+		 if (
+			    !((W[62]^(W[63]>>5)) & (1<<2))
+			 || !(!((W[41]^W[43]) & (1<<6)))
+		 )  mask &= ~DV_I_47_2_bit;
+	if (mask & DV_I_48_2_bit)
+		 if (
+			    !((W[63]^(W[64]>>5)) & (1<<2))
+			 || !(!((W[48]^(W[49]<<5)) & (1<<6)))
+		 )  mask &= ~DV_I_48_2_bit;
+	if (mask & DV_I_49_2_bit)
+		 if (
+			    !(!((W[49]^(W[50]<<5)) & (1<<6)))
+			 || !((W[42]^W[50]) & (1<<1))
+			 || !(!((W[39]^(W[40]<<5)) & (1<<6)))
+			 || !((W[38]^W[40]) & (1<<1))
+		 )  mask &= ~DV_I_49_2_bit;
+	if (mask & DV_I_50_0_bit)
+		mask &= ((((W[36]^W[37])<<7)) | ~DV_I_50_0_bit);
+	if (mask & DV_I_50_2_bit)
+		mask &= ((((W[43]^W[51])<<11)) | ~DV_I_50_2_bit);
+	if (mask & DV_I_51_0_bit)
+		mask &= ((((W[37]^W[38])<<9)) | ~DV_I_51_0_bit);
+	if (mask & DV_I_51_2_bit)
+		 if (
+			    !(!((W[51]^(W[52]<<5)) & (1<<6)))
+			 || !(!((W[49]^W[51]) & (1<<6)))
+			 || !(!((W[37]^(W[37]>>5)) & (1<<1)))
+			 || !(!((W[35]^(W[39]>>25)) & (1<<5)))
+		 )  mask &= ~DV_I_51_2_bit;
+	if (mask & DV_I_52_0_bit)
+		mask &= ((((W[38]^W[39])<<11)) | ~DV_I_52_0_bit);
+	if (mask & DV_II_46_2_bit)
+		mask &= ((((W[47]^W[51])<<17)) | ~DV_II_46_2_bit);
+	if (mask & DV_II_48_0_bit)
+		 if (
+			    !(!((W[36]^(W[40]>>25)) & (1<<3)))
+			 || !((W[35]^(W[40]<<2)) & (1<<30))
+		 )  mask &= ~DV_II_48_0_bit;
+	if (mask & DV_II_49_0_bit)
+		 if (
+			    !(!((W[37]^(W[41]>>25)) & (1<<3)))
+			 || !((W[36]^(W[41]<<2)) & (1<<30))
+		 )  mask &= ~DV_II_49_0_bit;
+	if (mask & DV_II_49_2_bit)
+		 if (
+			    !(!((W[53]^(W[54]<<5)) & (1<<6)))
+			 || !(!((W[51]^W[53]) & (1<<6)))
+			 || !((W[50]^W[54]) & (1<<1))
+			 || !(!((W[45]^(W[46]<<5)) & (1<<6)))
+			 || !(!((W[37]^(W[41]>>25)) & (1<<5)))
+			 || !((W[36]^(W[41]>>30)) & (1<<0))
+		 )  mask &= ~DV_II_49_2_bit;
+	if (mask & DV_II_50_0_bit)
+		 if (
+			    !((W[55]^W[58]) & (1<<29))
+			 || !(!((W[38]^(W[42]>>25)) & (1<<3)))
+			 || !((W[37]^(W[42]<<2)) & (1<<30))
+		 )  mask &= ~DV_II_50_0_bit;
+	if (mask & DV_II_50_2_bit)
+		 if (
+			    !(!((W[54]^(W[55]<<5)) & (1<<6)))
+			 || !(!((W[52]^W[54]) & (1<<6)))
+			 || !((W[51]^W[55]) & (1<<1))
+			 || !((W[45]^W[47]) & (1<<1))
+			 || !(!((W[38]^(W[42]>>25)) & (1<<5)))
+			 || !((W[37]^(W[42]>>30)) & (1<<0))
+		 )  mask &= ~DV_II_50_2_bit;
+	if (mask & DV_II_51_0_bit)
+		 if (
+			    !(!((W[39]^(W[43]>>25)) & (1<<3)))
+			 || !((W[38]^(W[43]<<2)) & (1<<30))
+		 )  mask &= ~DV_II_51_0_bit;
+	if (mask & DV_II_51_2_bit)
+		 if (
+			    !(!((W[55]^(W[56]<<5)) & (1<<6)))
+			 || !(!((W[53]^W[55]) & (1<<6)))
+			 || !((W[52]^W[56]) & (1<<1))
+			 || !((W[46]^W[48]) & (1<<1))
+			 || !(!((W[39]^(W[43]>>25)) & (1<<5)))
+			 || !((W[38]^(W[43]>>30)) & (1<<0))
+		 )  mask &= ~DV_II_51_2_bit;
+	if (mask & DV_II_52_0_bit)
+		 if (
+			    !(!((W[59]^W[60]) & (1<<29)))
+			 || !(!((W[40]^(W[44]>>25)) & (1<<3)))
+			 || !(!((W[40]^(W[44]>>25)) & (1<<4)))
+			 || !((W[39]^(W[44]<<2)) & (1<<30))
+		 )  mask &= ~DV_II_52_0_bit;
+	if (mask & DV_II_53_0_bit)
+		 if (
+			    !((W[58]^W[61]) & (1<<29))
+			 || !(!((W[57]^(W[61]>>25)) & (1<<4)))
+			 || !(!((W[41]^(W[45]>>25)) & (1<<3)))
+			 || !(!((W[41]^(W[45]>>25)) & (1<<4)))
+		 )  mask &= ~DV_II_53_0_bit;
+	if (mask & DV_II_54_0_bit)
+		 if (
+			    !(!((W[58]^(W[62]>>25)) & (1<<4)))
+			 || !(!((W[42]^(W[46]>>25)) & (1<<3)))
+			 || !(!((W[42]^(W[46]>>25)) & (1<<4)))
+		 )  mask &= ~DV_II_54_0_bit;
+	if (mask & DV_II_55_0_bit)
+		 if (
+			    !(!((W[59]^(W[63]>>25)) & (1<<4)))
+			 || !(!((W[57]^(W[59]>>25)) & (1<<4)))
+			 || !(!((W[43]^(W[47]>>25)) & (1<<3)))
+			 || !(!((W[43]^(W[47]>>25)) & (1<<4)))
+		 )  mask &= ~DV_II_55_0_bit;
+	if (mask & DV_II_56_0_bit)
+		 if (
+			    !(!((W[60]^(W[64]>>25)) & (1<<4)))
+			 || !(!((W[44]^(W[48]>>25)) & (1<<3)))
+			 || !(!((W[44]^(W[48]>>25)) & (1<<4)))
+		 )  mask &= ~DV_II_56_0_bit;
+}
+
+	dvmask[0]=mask;
+}
+
+#ifdef SHA1DC_CUSTOM_TRAILING_INCLUDE_UBC_CHECK_C
+#include SHA1DC_CUSTOM_TRAILING_INCLUDE_UBC_CHECK_C
+#endif

vendor/libgit2-sys/libgit2/src/hash/sha1dc/ubc_check.h

diff --git a/vendor/libgit2-sys/libgit2/src/hash/sha1dc/ubc_check.h b/vendor/libgit2-sys/libgit2/src/hash/sha1dc/ubc_check.h
new file mode 100644
index 0000000..d7e17dc
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/hash/sha1dc/ubc_check.h
@@ -0,0 +1,52 @@
+/***
+* Copyright 2017 Marc Stevens <marc@marc-stevens.nl>, Dan Shumow <danshu@microsoft.com>
+* Distributed under the MIT Software License.
+* See accompanying file LICENSE.txt or copy at
+* https://opensource.org/licenses/MIT
+***/
+
+/*
+// this file was generated by the 'parse_bitrel' program in the tools section
+// using the data files from directory 'tools/data/3565'
+//
+// sha1_dvs contains a list of SHA-1 Disturbance Vectors (DV) to check
+// dvType, dvK and dvB define the DV: I(K,B) or II(K,B) (see the paper)
+// dm[80] is the expanded message block XOR-difference defined by the DV
+// testt is the step to do the recompression from for collision detection
+// maski and maskb define the bit to check for each DV in the dvmask returned by ubc_check
+//
+// ubc_check takes as input an expanded message block and verifies the unavoidable bitconditions for all listed DVs
+// it returns a dvmask where each bit belonging to a DV is set if all unavoidable bitconditions for that DV have been met
+// thus one needs to do the recompression check for each DV that has its bit set
+*/
+
+#ifndef SHA1DC_UBC_CHECK_H
+#define SHA1DC_UBC_CHECK_H
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+#ifndef SHA1DC_NO_STANDARD_INCLUDES
+#include <stdint.h>
+#endif
+
+#define DVMASKSIZE 1
+typedef struct { int dvType; int dvK; int dvB; int testt; int maski; int maskb; uint32_t dm[80]; } dv_info_t;
+extern dv_info_t sha1_dvs[];
+void ubc_check(const uint32_t W[80], uint32_t dvmask[DVMASKSIZE]);
+
+#define DOSTORESTATE58
+#define DOSTORESTATE65
+
+#define CHECK_DVMASK(_DVMASK) (0 != _DVMASK[0])
+
+#if defined(__cplusplus)
+}
+#endif
+
+#ifdef SHA1DC_CUSTOM_TRAILING_INCLUDE_UBC_CHECK_H
+#include SHA1DC_CUSTOM_TRAILING_INCLUDE_UBC_CHECK_H
+#endif
+
+#endif

vendor/libgit2-sys/libgit2/src/hashsig.c

diff --git a/vendor/libgit2-sys/libgit2/src/hashsig.c b/vendor/libgit2-sys/libgit2/src/hashsig.c
new file mode 100644
index 0000000..30d0594
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/hashsig.c
@@ -0,0 +1,362 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "git2/sys/hashsig.h"
+#include "fileops.h"
+#include "util.h"
+
+typedef uint32_t hashsig_t;
+typedef uint64_t hashsig_state;
+
+#define HASHSIG_SCALE 100
+
+#define HASHSIG_MAX_RUN 80
+#define HASHSIG_HASH_START	0x012345678ABCDEF0LL
+#define HASHSIG_HASH_SHIFT  5
+
+#define HASHSIG_HASH_MIX(S,CH) \
+	(S) = ((S) << HASHSIG_HASH_SHIFT) - (S) + (hashsig_state)(CH)
+
+#define HASHSIG_HEAP_SIZE ((1 << 7) - 1)
+#define HASHSIG_HEAP_MIN_SIZE 4
+
+typedef int (*hashsig_cmp)(const void *a, const void *b, void *);
+
+typedef struct {
+	int size, asize;
+	hashsig_cmp cmp;
+	hashsig_t values[HASHSIG_HEAP_SIZE];
+} hashsig_heap;
+
+struct git_hashsig {
+	hashsig_heap mins;
+	hashsig_heap maxs;
+	size_t lines;
+	git_hashsig_option_t opt;
+};
+
+#define HEAP_LCHILD_OF(I) (((I)<<1)+1)
+#define HEAP_RCHILD_OF(I) (((I)<<1)+2)
+#define HEAP_PARENT_OF(I) (((I)-1)>>1)
+
+static void hashsig_heap_init(hashsig_heap *h, hashsig_cmp cmp)
+{
+	h->size  = 0;
+	h->asize = HASHSIG_HEAP_SIZE;
+	h->cmp   = cmp;
+}
+
+static int hashsig_cmp_max(const void *a, const void *b, void *payload)
+{
+	hashsig_t av = *(const hashsig_t *)a, bv = *(const hashsig_t *)b;
+	GIT_UNUSED(payload);
+	return (av < bv) ? -1 : (av > bv) ? 1 : 0;
+}
+
+static int hashsig_cmp_min(const void *a, const void *b, void *payload)
+{
+	hashsig_t av = *(const hashsig_t *)a, bv = *(const hashsig_t *)b;
+	GIT_UNUSED(payload);
+	return (av > bv) ? -1 : (av < bv) ? 1 : 0;
+}
+
+static void hashsig_heap_up(hashsig_heap *h, int el)
+{
+	int parent_el = HEAP_PARENT_OF(el);
+
+	while (el > 0 && h->cmp(&h->values[parent_el], &h->values[el], NULL) > 0) {
+		hashsig_t t = h->values[el];
+		h->values[el] = h->values[parent_el];
+		h->values[parent_el] = t;
+
+		el = parent_el;
+		parent_el = HEAP_PARENT_OF(el);
+	}
+}
+
+static void hashsig_heap_down(hashsig_heap *h, int el)
+{
+	hashsig_t v, lv, rv;
+
+	/* 'el < h->size / 2' tests if el is bottom row of heap */
+
+	while (el < h->size / 2) {
+		int lel = HEAP_LCHILD_OF(el), rel = HEAP_RCHILD_OF(el), swapel;
+
+		v  = h->values[el];
+		lv = h->values[lel];
+		rv = h->values[rel];
+
+		if (h->cmp(&v, &lv, NULL) < 0 && h->cmp(&v, &rv, NULL) < 0)
+			break;
+
+		swapel = (h->cmp(&lv, &rv, NULL) < 0) ? lel : rel;
+
+		h->values[el] = h->values[swapel];
+		h->values[swapel] = v;
+
+		el = swapel;
+	}
+}
+
+static void hashsig_heap_sort(hashsig_heap *h)
+{
+	/* only need to do this at the end for signature comparison */
+	git__qsort_r(h->values, h->size, sizeof(hashsig_t), h->cmp, NULL);
+}
+
+static void hashsig_heap_insert(hashsig_heap *h, hashsig_t val)
+{
+	/* if heap is not full, insert new element */
+	if (h->size < h->asize) {
+		h->values[h->size++] = val;
+		hashsig_heap_up(h, h->size - 1);
+	}
+
+	/* if heap is full, pop top if new element should replace it */
+	else if (h->cmp(&val, &h->values[0], NULL) > 0) {
+		h->size--;
+		h->values[0] = h->values[h->size];
+		hashsig_heap_down(h, 0);
+	}
+
+}
+
+typedef struct {
+	int use_ignores;
+	uint8_t ignore_ch[256];
+} hashsig_in_progress;
+
+static void hashsig_in_progress_init(
+	hashsig_in_progress *prog, git_hashsig *sig)
+{
+	int i;
+
+	/* no more than one can be set */
+	assert(!(sig->opt & GIT_HASHSIG_IGNORE_WHITESPACE) ||
+		   !(sig->opt & GIT_HASHSIG_SMART_WHITESPACE));
+
+	if (sig->opt & GIT_HASHSIG_IGNORE_WHITESPACE) {
+		for (i = 0; i < 256; ++i)
+			prog->ignore_ch[i] = git__isspace_nonlf(i);
+		prog->use_ignores = 1;
+	} else if (sig->opt & GIT_HASHSIG_SMART_WHITESPACE) {
+		for (i = 0; i < 256; ++i)
+			prog->ignore_ch[i] = git__isspace(i);
+		prog->use_ignores = 1;
+	} else {
+		memset(prog, 0, sizeof(*prog));
+	}
+}
+
+static int hashsig_add_hashes(
+	git_hashsig *sig,
+	const uint8_t *data,
+	size_t size,
+	hashsig_in_progress *prog)
+{
+	const uint8_t *scan = data, *end = data + size;
+	hashsig_state state = HASHSIG_HASH_START;
+	int use_ignores = prog->use_ignores, len;
+	uint8_t ch;
+
+	while (scan < end) {
+		state = HASHSIG_HASH_START;
+
+		for (len = 0; scan < end && len < HASHSIG_MAX_RUN; ) {
+			ch = *scan;
+
+			if (use_ignores)
+				for (; scan < end && git__isspace_nonlf(ch); ch = *scan)
+					++scan;
+			else if (sig->opt &
+					 (GIT_HASHSIG_IGNORE_WHITESPACE | GIT_HASHSIG_SMART_WHITESPACE))
+				for (; scan < end && ch == '\r'; ch = *scan)
+					++scan;
+
+			/* peek at next character to decide what to do next */
+			if (sig->opt & GIT_HASHSIG_SMART_WHITESPACE)
+				use_ignores = (ch == '\n');
+
+			if (scan >= end)
+				break;
+			++scan;
+
+			/* check run terminator */
+			if (ch == '\n' || ch == '\0') {
+				sig->lines++;
+				break;
+			}
+
+			++len;
+			HASHSIG_HASH_MIX(state, ch);
+		}
+
+		if (len > 0) {
+			hashsig_heap_insert(&sig->mins, (hashsig_t)state);
+			hashsig_heap_insert(&sig->maxs, (hashsig_t)state);
+
+			while (scan < end && (*scan == '\n' || !*scan))
+				++scan;
+		}
+	}
+
+	prog->use_ignores = use_ignores;
+
+	return 0;
+}
+
+static int hashsig_finalize_hashes(git_hashsig *sig)
+{
+	if (sig->mins.size < HASHSIG_HEAP_MIN_SIZE &&
+		!(sig->opt & GIT_HASHSIG_ALLOW_SMALL_FILES)) {
+		giterr_set(GITERR_INVALID,
+			"file too small for similarity signature calculation");
+		return GIT_EBUFS;
+	}
+
+	hashsig_heap_sort(&sig->mins);
+	hashsig_heap_sort(&sig->maxs);
+
+	return 0;
+}
+
+static git_hashsig *hashsig_alloc(git_hashsig_option_t opts)
+{
+	git_hashsig *sig = git__calloc(1, sizeof(git_hashsig));
+	if (!sig)
+		return NULL;
+
+	hashsig_heap_init(&sig->mins, hashsig_cmp_min);
+	hashsig_heap_init(&sig->maxs, hashsig_cmp_max);
+	sig->opt = opts;
+
+	return sig;
+}
+
+int git_hashsig_create(
+	git_hashsig **out,
+	const char *buf,
+	size_t buflen,
+	git_hashsig_option_t opts)
+{
+	int error;
+	hashsig_in_progress prog;
+	git_hashsig *sig = hashsig_alloc(opts);
+	GITERR_CHECK_ALLOC(sig);
+
+	hashsig_in_progress_init(&prog, sig);
+
+	error = hashsig_add_hashes(sig, (const uint8_t *)buf, buflen, &prog);
+
+	if (!error)
+		error = hashsig_finalize_hashes(sig);
+
+	if (!error)
+		*out = sig;
+	else
+		git_hashsig_free(sig);
+
+	return error;
+}
+
+int git_hashsig_create_fromfile(
+	git_hashsig **out,
+	const char *path,
+	git_hashsig_option_t opts)
+{
+	uint8_t buf[0x1000];
+	ssize_t buflen = 0;
+	int error = 0, fd;
+	hashsig_in_progress prog;
+	git_hashsig *sig = hashsig_alloc(opts);
+	GITERR_CHECK_ALLOC(sig);
+
+	if ((fd = git_futils_open_ro(path)) < 0) {
+		git__free(sig);
+		return fd;
+	}
+
+	hashsig_in_progress_init(&prog, sig);
+
+	while (!error) {
+		if ((buflen = p_read(fd, buf, sizeof(buf))) <= 0) {
+			if ((error = (int)buflen) < 0)
+				giterr_set(GITERR_OS,
+					"read error on '%s' calculating similarity hashes", path);
+			break;
+		}
+
+		error = hashsig_add_hashes(sig, buf, buflen, &prog);
+	}
+
+	p_close(fd);
+
+	if (!error)
+		error = hashsig_finalize_hashes(sig);
+
+	if (!error)
+		*out = sig;
+	else
+		git_hashsig_free(sig);
+
+	return error;
+}
+
+void git_hashsig_free(git_hashsig *sig)
+{
+	git__free(sig);
+}
+
+static int hashsig_heap_compare(const hashsig_heap *a, const hashsig_heap *b)
+{
+	int matches = 0, i, j, cmp;
+
+	assert(a->cmp == b->cmp);
+
+	/* hash heaps are sorted - just look for overlap vs total */
+
+	for (i = 0, j = 0; i < a->size && j < b->size; ) {
+		cmp = a->cmp(&a->values[i], &b->values[j], NULL);
+
+		if (cmp < 0)
+			++i;
+		else if (cmp > 0)
+			++j;
+		else {
+			++i; ++j; ++matches;
+		}
+	}
+
+	return HASHSIG_SCALE * (matches * 2) / (a->size + b->size);
+}
+
+int git_hashsig_compare(const git_hashsig *a, const git_hashsig *b)
+{
+	/* if we have no elements in either file then each file is either
+	 * empty or blank.  if we're ignoring whitespace then the files are
+	 * similar, otherwise they're dissimilar.
+	 */
+	if (a->mins.size == 0 && b->mins.size == 0) {
+		if ((!a->lines && !b->lines) ||
+			(a->opt & GIT_HASHSIG_IGNORE_WHITESPACE))
+			return HASHSIG_SCALE;
+		else
+			return 0;
+	}
+
+	/* if we have fewer than the maximum number of elements, then just use
+	 * one array since the two arrays will be the same
+	 */
+	if (a->mins.size < HASHSIG_HEAP_SIZE)
+		return hashsig_heap_compare(&a->mins, &b->mins);
+	else
+		return (hashsig_heap_compare(&a->mins, &b->mins) +
+				hashsig_heap_compare(&a->maxs, &b->maxs)) / 2;
+}

vendor/libgit2-sys/libgit2/src/ident.c

diff --git a/vendor/libgit2-sys/libgit2/src/ident.c b/vendor/libgit2-sys/libgit2/src/ident.c
new file mode 100644
index 0000000..7eccf9a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/ident.c
@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "git2/sys/filter.h"
+#include "filter.h"
+#include "buffer.h"
+#include "buf_text.h"
+
+static int ident_find_id(
+	const char **id_start, const char **id_end, const char *start, size_t len)
+{
+	const char *end = start + len, *found = NULL;
+
+	while (len > 3 && (found = memchr(start, '$', len)) != NULL) {
+		size_t remaining = (size_t)(end - found) - 1;
+		if (remaining < 3)
+			return GIT_ENOTFOUND;
+
+		start = found + 1;
+		len   = remaining;
+
+		if (start[0] == 'I' && start[1] == 'd')
+			break;
+	}
+
+	if (len < 3 || !found)
+		return GIT_ENOTFOUND;
+	*id_start = found;
+
+	if ((found = memchr(start + 2, '$', len - 2)) == NULL)
+		return GIT_ENOTFOUND;
+
+	*id_end = found + 1;
+	return 0;
+}
+
+static int ident_insert_id(
+	git_buf *to, const git_buf *from, const git_filter_source *src)
+{
+	char oid[GIT_OID_HEXSZ+1];
+	const char *id_start, *id_end, *from_end = from->ptr + from->size;
+	size_t need_size;
+
+	/* replace $Id$ with blob id */
+
+	if (!git_filter_source_id(src))
+		return GIT_PASSTHROUGH;
+
+	git_oid_tostr(oid, sizeof(oid), git_filter_source_id(src));
+
+	if (ident_find_id(&id_start, &id_end, from->ptr, from->size) < 0)
+		return GIT_PASSTHROUGH;
+
+	need_size = (size_t)(id_start - from->ptr) +
+		5 /* "$Id: " */ + GIT_OID_HEXSZ + 2 /* " $" */ +
+		(size_t)(from_end - id_end);
+
+	if (git_buf_grow(to, need_size) < 0)
+		return -1;
+
+	git_buf_set(to, from->ptr, (size_t)(id_start - from->ptr));
+	git_buf_put(to, "$Id: ", 5);
+	git_buf_put(to, oid, GIT_OID_HEXSZ);
+	git_buf_put(to, " $", 2);
+	git_buf_put(to, id_end, (size_t)(from_end - id_end));
+
+	return git_buf_oom(to) ? -1 : 0;
+}
+
+static int ident_remove_id(
+	git_buf *to, const git_buf *from)
+{
+	const char *id_start, *id_end, *from_end = from->ptr + from->size;
+	size_t need_size;
+
+	if (ident_find_id(&id_start, &id_end, from->ptr, from->size) < 0)
+		return GIT_PASSTHROUGH;
+
+	need_size = (size_t)(id_start - from->ptr) +
+		4 /* "$Id$" */ + (size_t)(from_end - id_end);
+
+	if (git_buf_grow(to, need_size) < 0)
+		return -1;
+
+	git_buf_set(to, from->ptr, (size_t)(id_start - from->ptr));
+	git_buf_put(to, "$Id$", 4);
+	git_buf_put(to, id_end, (size_t)(from_end - id_end));
+
+	return git_buf_oom(to) ? -1 : 0;
+}
+
+static int ident_apply(
+	git_filter     *self,
+	void          **payload,
+	git_buf        *to,
+	const git_buf  *from,
+	const git_filter_source *src)
+{
+	GIT_UNUSED(self); GIT_UNUSED(payload);
+
+	/* Don't filter binary files */
+	if (git_buf_text_is_binary(from))
+		return GIT_PASSTHROUGH;
+
+	if (git_filter_source_mode(src) == GIT_FILTER_SMUDGE)
+		return ident_insert_id(to, from, src);
+	else
+		return ident_remove_id(to, from);
+}
+
+git_filter *git_ident_filter_new(void)
+{
+	git_filter *f = git__calloc(1, sizeof(git_filter));
+	if (f == NULL)
+		return NULL;
+
+	f->version = GIT_FILTER_VERSION;
+	f->attributes = "+ident"; /* apply to files with ident attribute set */
+	f->shutdown = git_filter_free;
+	f->apply    = ident_apply;
+
+	return f;
+}

vendor/libgit2-sys/libgit2/src/idxmap.c

diff --git a/vendor/libgit2-sys/libgit2/src/idxmap.c b/vendor/libgit2-sys/libgit2/src/idxmap.c
new file mode 100644
index 0000000..45f0c22
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/idxmap.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "idxmap.h"
+
+/* This is __ac_X31_hash_string but with tolower and it takes the entry's stage into account */
+static kh_inline khint_t idxentry_hash(const git_index_entry *e)
+{
+	const char *s = e->path;
+	khint_t h = (khint_t)git__tolower(*s);
+	if (h) for (++s ; *s; ++s) h = (h << 5) - h + (khint_t)git__tolower(*s);
+	return h + GIT_IDXENTRY_STAGE(e);
+}
+
+#define idxentry_equal(a, b) (GIT_IDXENTRY_STAGE(a) == GIT_IDXENTRY_STAGE(b) && strcmp(a->path, b->path) == 0)
+#define idxentry_icase_equal(a, b) (GIT_IDXENTRY_STAGE(a) == GIT_IDXENTRY_STAGE(b) && strcasecmp(a->path, b->path) == 0)
+
+__KHASH_IMPL(idx, static kh_inline, const git_index_entry *, git_index_entry *, 1, idxentry_hash, idxentry_equal)
+__KHASH_IMPL(idxicase, static kh_inline, const git_index_entry *, git_index_entry *, 1, idxentry_hash, idxentry_icase_equal)
+
+int git_idxmap_alloc(git_idxmap **map)
+{
+	if ((*map = kh_init(idx)) == NULL) {
+		giterr_set_oom();
+		return -1;
+	}
+
+	return 0;
+}
+
+int git_idxmap_icase_alloc(git_idxmap_icase **map)
+{
+	if ((*map = kh_init(idxicase)) == NULL) {
+		giterr_set_oom();
+		return -1;
+	}
+
+	return 0;
+}
+
+void git_idxmap_insert(git_idxmap *map, const git_index_entry *key, void *value, int *rval)
+{
+	khiter_t idx = kh_put(idx, map, key, rval);
+
+	if ((*rval) >= 0) {
+		if ((*rval) == 0)
+			kh_key(map, idx) = key;
+		kh_val(map, idx) = value;
+	}
+}
+
+void git_idxmap_icase_insert(git_idxmap_icase *map, const git_index_entry *key, void *value, int *rval)
+{
+	khiter_t idx = kh_put(idxicase, map, key, rval);
+
+	if ((*rval) >= 0) {
+		if ((*rval) == 0)
+			kh_key(map, idx) = key;
+		kh_val(map, idx) = value;
+	}
+}
+
+size_t git_idxmap_lookup_index(git_idxmap *map, const git_index_entry *key)
+{
+	return kh_get(idx, map, key);
+}
+
+size_t git_idxmap_icase_lookup_index(git_idxmap_icase *map, const git_index_entry *key)
+{
+	return kh_get(idxicase, map, key);
+}
+
+void *git_idxmap_value_at(git_idxmap *map, size_t idx)
+{
+	return kh_val(map, idx);
+}
+
+int git_idxmap_valid_index(git_idxmap *map, size_t idx)
+{
+	return idx != kh_end(map);
+}
+
+int git_idxmap_has_data(git_idxmap *map, size_t idx)
+{
+	return kh_exist(map, idx);
+}
+
+void git_idxmap_resize(git_idxmap *map, size_t size)
+{
+	kh_resize(idx, map, size);
+}
+
+void git_idxmap_icase_resize(git_idxmap_icase *map, size_t size)
+{
+	kh_resize(idxicase, map, size);
+}
+
+void git_idxmap_free(git_idxmap *map)
+{
+	kh_destroy(idx, map);
+}
+
+void git_idxmap_clear(git_idxmap *map)
+{
+	kh_clear(idx, map);
+}
+
+void git_idxmap_delete_at(git_idxmap *map, size_t idx)
+{
+	kh_del(idx, map, idx);
+}
+
+void git_idxmap_icase_delete_at(git_idxmap_icase *map, size_t idx)
+{
+	kh_del(idxicase, map, idx);
+}
+
+void git_idxmap_delete(git_idxmap *map, const git_index_entry *key)
+{
+	khiter_t idx = git_idxmap_lookup_index(map, key);
+	if (git_idxmap_valid_index(map, idx))
+		git_idxmap_delete_at(map, idx);
+}
+void git_idxmap_icase_delete(git_idxmap_icase *map, const git_index_entry *key)
+{
+	khiter_t idx = git_idxmap_icase_lookup_index(map, key);
+	if (git_idxmap_valid_index((git_idxmap *)map, idx))
+		git_idxmap_icase_delete_at(map, idx);
+}

vendor/libgit2-sys/libgit2/src/idxmap.h

diff --git a/vendor/libgit2-sys/libgit2/src/idxmap.h b/vendor/libgit2-sys/libgit2/src/idxmap.h
new file mode 100644
index 0000000..f7e903a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/idxmap.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_idxmap_h__
+#define INCLUDE_idxmap_h__
+
+#include "common.h"
+
+#include <ctype.h>
+#include "git2/index.h"
+
+#define kmalloc git__malloc
+#define kcalloc git__calloc
+#define krealloc git__realloc
+#define kreallocarray git__reallocarray
+#define kfree git__free
+#include "khash.h"
+
+__KHASH_TYPE(idx, const git_index_entry *, git_index_entry *)
+__KHASH_TYPE(idxicase, const git_index_entry *, git_index_entry *)
+
+typedef khash_t(idx) git_idxmap;
+typedef khash_t(idxicase) git_idxmap_icase;
+
+typedef khiter_t git_idxmap_iter;
+
+int git_idxmap_alloc(git_idxmap **map);
+int git_idxmap_icase_alloc(git_idxmap_icase **map);
+void git_idxmap_insert(git_idxmap *map, const git_index_entry *key, void *value, int *rval);
+void git_idxmap_icase_insert(git_idxmap_icase *map, const git_index_entry *key, void *value, int *rval);
+
+size_t git_idxmap_lookup_index(git_idxmap *map, const git_index_entry *key);
+size_t git_idxmap_icase_lookup_index(git_idxmap_icase *map, const git_index_entry *key);
+void *git_idxmap_value_at(git_idxmap *map, size_t idx);
+int git_idxmap_valid_index(git_idxmap *map, size_t idx);
+int git_idxmap_has_data(git_idxmap *map, size_t idx);
+
+void git_idxmap_resize(git_idxmap *map, size_t size);
+void git_idxmap_icase_resize(git_idxmap_icase *map, size_t size);
+void git_idxmap_free(git_idxmap *map);
+void git_idxmap_clear(git_idxmap *map);
+
+void git_idxmap_delete_at(git_idxmap *map, size_t idx);
+void git_idxmap_icase_delete_at(git_idxmap_icase *map, size_t idx);
+
+void git_idxmap_delete(git_idxmap *map, const git_index_entry *key);
+void git_idxmap_icase_delete(git_idxmap_icase *map, const git_index_entry *key);
+
+#define git_idxmap_begin		kh_begin
+#define git_idxmap_end		kh_end
+
+#endif

vendor/libgit2-sys/libgit2/src/ignore.c

diff --git a/vendor/libgit2-sys/libgit2/src/ignore.c b/vendor/libgit2-sys/libgit2/src/ignore.c
new file mode 100644
index 0000000..76b9972
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/ignore.c
@@ -0,0 +1,644 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "ignore.h"
+
+#include "git2/ignore.h"
+#include "common.h"
+#include "attrcache.h"
+#include "path.h"
+#include "config.h"
+#include "fnmatch.h"
+
+#define GIT_IGNORE_INTERNAL		"[internal]exclude"
+
+#define GIT_IGNORE_DEFAULT_RULES ".\n..\n.git\n"
+
+/**
+ * A negative ignore pattern can negate a positive one without
+ * wildcards if it is a basename only and equals the basename of
+ * the positive pattern. Thus
+ *
+ * foo/bar
+ * !bar
+ *
+ * would result in foo/bar being unignored again while
+ *
+ * moo/foo/bar
+ * !foo/bar
+ *
+ * would do nothing. The reverse also holds true: a positive
+ * basename pattern can be negated by unignoring the basename in
+ * subdirectories. Thus
+ *
+ * bar
+ * !foo/bar
+ *
+ * would result in foo/bar being unignored again. As with the
+ * first case,
+ *
+ * foo/bar
+ * !moo/foo/bar
+ *
+ * would do nothing, again.
+ */
+static int does_negate_pattern(git_attr_fnmatch *rule, git_attr_fnmatch *neg)
+{
+	int (*cmp)(const char *, const char *, size_t);
+	git_attr_fnmatch *longer, *shorter;
+	char *p;
+
+	if ((rule->flags & GIT_ATTR_FNMATCH_NEGATIVE) != 0
+	    || (neg->flags & GIT_ATTR_FNMATCH_NEGATIVE) == 0)
+		return false;
+
+	if (neg->flags & GIT_ATTR_FNMATCH_ICASE)
+		cmp = git__strncasecmp;
+	else
+		cmp = git__strncmp;
+
+	/* If lengths match we need to have an exact match */
+	if (rule->length == neg->length) {
+		return cmp(rule->pattern, neg->pattern, rule->length) == 0;
+	} else if (rule->length < neg->length) {
+		shorter = rule;
+		longer = neg;
+	} else {
+		shorter = neg;
+		longer = rule;
+	}
+
+	/* Otherwise, we need to check if the shorter
+	 * rule is a basename only (that is, it contains
+	 * no path separator) and, if so, if it
+	 * matches the tail of the longer rule */
+	p = longer->pattern + longer->length - shorter->length;
+
+	if (p[-1] != '/')
+		return false;
+	if (memchr(shorter->pattern, '/', shorter->length) != NULL)
+		return false;
+
+	return cmp(p, shorter->pattern, shorter->length) == 0;
+}
+
+/**
+ * A negative ignore can only unignore a file which is given explicitly before, thus
+ *
+ *    foo
+ *    !foo/bar
+ *
+ * does not unignore 'foo/bar' as it's not in the list. However
+ *
+ *    foo/<star>
+ *    !foo/bar
+ *
+ * does unignore 'foo/bar', as it is contained within the 'foo/<star>' rule.
+ */
+static int does_negate_rule(int *out, git_vector *rules, git_attr_fnmatch *match)
+{
+	int error = 0, fnflags;
+	size_t i;
+	git_attr_fnmatch *rule;
+	char *path;
+	git_buf buf = GIT_BUF_INIT;
+
+	*out = 0;
+
+	fnflags = FNM_PATHNAME;
+	if (match->flags & GIT_ATTR_FNMATCH_ICASE)
+		fnflags |= FNM_IGNORECASE;
+
+	/* path of the file relative to the workdir, so we match the rules in subdirs */
+	if (match->containing_dir) {
+		git_buf_puts(&buf, match->containing_dir);
+	}
+	if (git_buf_puts(&buf, match->pattern) < 0)
+		return -1;
+
+	path = git_buf_detach(&buf);
+
+	git_vector_foreach(rules, i, rule) {
+		if (!(rule->flags & GIT_ATTR_FNMATCH_HASWILD)) {
+			if (does_negate_pattern(rule, match)) {
+				error = 0;
+				*out = 1;
+				goto out;
+			}
+			else
+				continue;
+		}
+
+		/*
+		 * When dealing with a directory, we add '/<star>' so
+		 * p_fnmatch() honours FNM_PATHNAME. Checking for LEADINGDIR
+		 * alone isn't enough as that's also set for nagations, so we
+		 * need to check that NEGATIVE is off.
+		 */
+		git_buf_clear(&buf);
+		if (rule->containing_dir) {
+			git_buf_puts(&buf, rule->containing_dir);
+		}
+
+		error = git_buf_puts(&buf, rule->pattern);
+
+		if ((rule->flags & (GIT_ATTR_FNMATCH_LEADINGDIR | GIT_ATTR_FNMATCH_NEGATIVE)) == GIT_ATTR_FNMATCH_LEADINGDIR)
+			error = git_buf_PUTS(&buf, "/*");
+
+		if (error < 0)
+			goto out;
+
+		if ((error = p_fnmatch(git_buf_cstr(&buf), path, fnflags)) < 0) {
+			giterr_set(GITERR_INVALID, "error matching pattern");
+			goto out;
+		}
+
+		/* if we found a match, we want to keep this rule */
+		if (error != FNM_NOMATCH) {
+			*out = 1;
+			error = 0;
+			goto out;
+		}
+	}
+
+	error = 0;
+
+out:
+	git__free(path);
+	git_buf_free(&buf);
+	return error;
+}
+
+static int parse_ignore_file(
+	git_repository *repo, git_attr_file *attrs, const char *data)
+{
+	int error = 0;
+	int ignore_case = false;
+	const char *scan = data, *context = NULL;
+	git_attr_fnmatch *match = NULL;
+
+	if (git_repository__cvar(&ignore_case, repo, GIT_CVAR_IGNORECASE) < 0)
+		giterr_clear();
+
+	/* if subdir file path, convert context for file paths */
+	if (attrs->entry &&
+		git_path_root(attrs->entry->path) < 0 &&
+		!git__suffixcmp(attrs->entry->path, "/" GIT_IGNORE_FILE))
+		context = attrs->entry->path;
+
+	if (git_mutex_lock(&attrs->lock) < 0) {
+		giterr_set(GITERR_OS, "failed to lock ignore file");
+		return -1;
+	}
+
+	while (!error && *scan) {
+		int valid_rule = 1;
+
+		if (!match && !(match = git__calloc(1, sizeof(*match)))) {
+			error = -1;
+			break;
+		}
+
+		match->flags = GIT_ATTR_FNMATCH_ALLOWSPACE | GIT_ATTR_FNMATCH_ALLOWNEG;
+
+		if (!(error = git_attr_fnmatch__parse(
+			match, &attrs->pool, context, &scan)))
+		{
+			match->flags |= GIT_ATTR_FNMATCH_IGNORE;
+
+			if (ignore_case)
+				match->flags |= GIT_ATTR_FNMATCH_ICASE;
+
+			scan = git__next_line(scan);
+
+			/*
+			 * If a negative match doesn't actually do anything,
+			 * throw it away. As we cannot always verify whether a
+			 * rule containing wildcards negates another rule, we
+			 * do not optimize away these rules, though.
+			 * */
+			if (match->flags & GIT_ATTR_FNMATCH_NEGATIVE
+			    && !(match->flags & GIT_ATTR_FNMATCH_HASWILD))
+				error = does_negate_rule(&valid_rule, &attrs->rules, match);
+
+			if (!error && valid_rule)
+				error = git_vector_insert(&attrs->rules, match);
+		}
+
+		if (error != 0 || !valid_rule) {
+			match->pattern = NULL;
+
+			if (error == GIT_ENOTFOUND)
+				error = 0;
+		} else {
+			match = NULL; /* vector now "owns" the match */
+		}
+	}
+
+	git_mutex_unlock(&attrs->lock);
+	git__free(match);
+
+	return error;
+}
+
+static int push_ignore_file(
+	git_ignores *ignores,
+	git_vector *which_list,
+	const char *base,
+	const char *filename)
+{
+	int error = 0;
+	git_attr_file *file = NULL;
+
+	error = git_attr_cache__get(
+		&file, ignores->repo, NULL, GIT_ATTR_FILE__FROM_FILE,
+		base, filename, parse_ignore_file);
+	if (error < 0)
+		return error;
+
+	if (file != NULL) {
+		if ((error = git_vector_insert(which_list, file)) < 0)
+			git_attr_file__free(file);
+	}
+
+	return error;
+}
+
+static int push_one_ignore(void *payload, const char *path)
+{
+	git_ignores *ign = payload;
+	ign->depth++;
+	return push_ignore_file(ign, &ign->ign_path, path, GIT_IGNORE_FILE);
+}
+
+static int get_internal_ignores(git_attr_file **out, git_repository *repo)
+{
+	int error;
+
+	if ((error = git_attr_cache__init(repo)) < 0)
+		return error;
+
+	error = git_attr_cache__get(
+		out, repo, NULL, GIT_ATTR_FILE__IN_MEMORY, NULL, GIT_IGNORE_INTERNAL, NULL);
+
+	/* if internal rules list is empty, insert default rules */
+	if (!error && !(*out)->rules.length)
+		error = parse_ignore_file(repo, *out, GIT_IGNORE_DEFAULT_RULES);
+
+	return error;
+}
+
+int git_ignore__for_path(
+	git_repository *repo,
+	const char *path,
+	git_ignores *ignores)
+{
+	int error = 0;
+	const char *workdir = git_repository_workdir(repo);
+	git_buf infopath = GIT_BUF_INIT;
+
+	assert(repo && ignores && path);
+
+	memset(ignores, 0, sizeof(*ignores));
+	ignores->repo = repo;
+
+	/* Read the ignore_case flag */
+	if ((error = git_repository__cvar(
+			&ignores->ignore_case, repo, GIT_CVAR_IGNORECASE)) < 0)
+		goto cleanup;
+
+	if ((error = git_attr_cache__init(repo)) < 0)
+		goto cleanup;
+
+	/* given a unrooted path in a non-bare repo, resolve it */
+	if (workdir && git_path_root(path) < 0) {
+		git_buf local = GIT_BUF_INIT;
+
+		if ((error = git_path_dirname_r(&local, path)) < 0 ||
+		    (error = git_path_resolve_relative(&local, 0)) < 0 ||
+		    (error = git_path_to_dir(&local)) < 0 ||
+		    (error = git_buf_joinpath(&ignores->dir, workdir, local.ptr)) < 0)
+		{;} /* Nothing, we just want to stop on the first error */
+		git_buf_free(&local);
+	} else {
+		error = git_buf_joinpath(&ignores->dir, path, "");
+	}
+	if (error < 0)
+		goto cleanup;
+
+	if (workdir && !git__prefixcmp(ignores->dir.ptr, workdir))
+		ignores->dir_root = strlen(workdir);
+
+	/* set up internals */
+	if ((error = get_internal_ignores(&ignores->ign_internal, repo)) < 0)
+		goto cleanup;
+
+	/* load .gitignore up the path */
+	if (workdir != NULL) {
+		error = git_path_walk_up(
+			&ignores->dir, workdir, push_one_ignore, ignores);
+		if (error < 0)
+			goto cleanup;
+	}
+
+	if ((error = git_repository_item_path(&infopath,
+			repo, GIT_REPOSITORY_ITEM_INFO)) < 0)
+		goto cleanup;
+
+	/* load .git/info/exclude */
+	error = push_ignore_file(
+		ignores, &ignores->ign_global,
+		infopath.ptr, GIT_IGNORE_FILE_INREPO);
+	if (error < 0)
+		goto cleanup;
+
+	/* load core.excludesfile */
+	if (git_repository_attr_cache(repo)->cfg_excl_file != NULL)
+		error = push_ignore_file(
+			ignores, &ignores->ign_global, NULL,
+			git_repository_attr_cache(repo)->cfg_excl_file);
+
+cleanup:
+	git_buf_free(&infopath);
+	if (error < 0)
+		git_ignore__free(ignores);
+
+	return error;
+}
+
+int git_ignore__push_dir(git_ignores *ign, const char *dir)
+{
+	if (git_buf_joinpath(&ign->dir, ign->dir.ptr, dir) < 0)
+		return -1;
+
+	ign->depth++;
+
+	return push_ignore_file(
+		ign, &ign->ign_path, ign->dir.ptr, GIT_IGNORE_FILE);
+}
+
+int git_ignore__pop_dir(git_ignores *ign)
+{
+	if (ign->ign_path.length > 0) {
+		git_attr_file *file = git_vector_last(&ign->ign_path);
+		const char *start = file->entry->path, *end;
+
+		/* - ign->dir looks something like "/home/user/a/b/" (or "a/b/c/d/")
+		 * - file->path looks something like "a/b/.gitignore
+		 *
+		 * We are popping the last directory off ign->dir.  We also want
+		 * to remove the file from the vector if the popped directory
+		 * matches the ignore path.  We need to test if the "a/b" part of
+		 * the file key matches the path we are about to pop.
+		 */
+
+		if ((end = strrchr(start, '/')) != NULL) {
+			size_t dirlen = (end - start) + 1;
+			const char *relpath = ign->dir.ptr + ign->dir_root;
+			size_t pathlen = ign->dir.size - ign->dir_root;
+
+			if (pathlen == dirlen && !memcmp(relpath, start, dirlen)) {
+				git_vector_pop(&ign->ign_path);
+				git_attr_file__free(file);
+			}
+		}
+	}
+
+	if (--ign->depth > 0) {
+		git_buf_rtruncate_at_char(&ign->dir, '/');
+		git_path_to_dir(&ign->dir);
+	}
+
+	return 0;
+}
+
+void git_ignore__free(git_ignores *ignores)
+{
+	unsigned int i;
+	git_attr_file *file;
+
+	git_attr_file__free(ignores->ign_internal);
+
+	git_vector_foreach(&ignores->ign_path, i, file) {
+		git_attr_file__free(file);
+		ignores->ign_path.contents[i] = NULL;
+	}
+	git_vector_free(&ignores->ign_path);
+
+	git_vector_foreach(&ignores->ign_global, i, file) {
+		git_attr_file__free(file);
+		ignores->ign_global.contents[i] = NULL;
+	}
+	git_vector_free(&ignores->ign_global);
+
+	git_buf_free(&ignores->dir);
+}
+
+static bool ignore_lookup_in_rules(
+	int *ignored, git_attr_file *file, git_attr_path *path)
+{
+	size_t j;
+	git_attr_fnmatch *match;
+
+	git_vector_rforeach(&file->rules, j, match) {
+		if (git_attr_fnmatch__match(match, path)) {
+			*ignored = ((match->flags & GIT_ATTR_FNMATCH_NEGATIVE) == 0) ?
+				GIT_IGNORE_TRUE : GIT_IGNORE_FALSE;
+			return true;
+		}
+	}
+
+	return false;
+}
+
+int git_ignore__lookup(
+	int *out, git_ignores *ignores, const char *pathname, git_dir_flag dir_flag)
+{
+	unsigned int i;
+	git_attr_file *file;
+	git_attr_path path;
+
+	*out = GIT_IGNORE_NOTFOUND;
+
+	if (git_attr_path__init(
+		&path, pathname, git_repository_workdir(ignores->repo), dir_flag) < 0)
+		return -1;
+
+	/* first process builtins - success means path was found */
+	if (ignore_lookup_in_rules(out, ignores->ign_internal, &path))
+		goto cleanup;
+
+	/* next process files in the path */
+	git_vector_foreach(&ignores->ign_path, i, file) {
+		if (ignore_lookup_in_rules(out, file, &path))
+			goto cleanup;
+	}
+
+	/* last process global ignores */
+	git_vector_foreach(&ignores->ign_global, i, file) {
+		if (ignore_lookup_in_rules(out, file, &path))
+			goto cleanup;
+	}
+
+cleanup:
+	git_attr_path__free(&path);
+	return 0;
+}
+
+int git_ignore_add_rule(git_repository *repo, const char *rules)
+{
+	int error;
+	git_attr_file *ign_internal = NULL;
+
+	if ((error = get_internal_ignores(&ign_internal, repo)) < 0)
+		return error;
+
+	error = parse_ignore_file(repo, ign_internal, rules);
+	git_attr_file__free(ign_internal);
+
+	return error;
+}
+
+int git_ignore_clear_internal_rules(git_repository *repo)
+{
+	int error;
+	git_attr_file *ign_internal;
+
+	if ((error = get_internal_ignores(&ign_internal, repo)) < 0)
+		return error;
+
+	if (!(error = git_attr_file__clear_rules(ign_internal, true)))
+		error = parse_ignore_file(
+			repo, ign_internal, GIT_IGNORE_DEFAULT_RULES);
+
+	git_attr_file__free(ign_internal);
+	return error;
+}
+
+int git_ignore_path_is_ignored(
+	int *ignored,
+	git_repository *repo,
+	const char *pathname)
+{
+	int error;
+	const char *workdir;
+	git_attr_path path;
+	git_ignores ignores;
+	unsigned int i;
+	git_attr_file *file;
+	git_dir_flag dir_flag = GIT_DIR_FLAG_UNKNOWN;
+
+	assert(repo && ignored && pathname);
+
+	workdir = git_repository_workdir(repo);
+
+	memset(&path, 0, sizeof(path));
+	memset(&ignores, 0, sizeof(ignores));
+
+	if (git_repository_is_bare(repo))
+		dir_flag = GIT_DIR_FLAG_FALSE;
+
+	if ((error = git_attr_path__init(&path, pathname, workdir, dir_flag)) < 0 ||
+		(error = git_ignore__for_path(repo, path.path, &ignores)) < 0)
+		goto cleanup;
+
+	while (1) {
+		/* first process builtins - success means path was found */
+		if (ignore_lookup_in_rules(ignored, ignores.ign_internal, &path))
+			goto cleanup;
+
+		/* next process files in the path */
+		git_vector_foreach(&ignores.ign_path, i, file) {
+			if (ignore_lookup_in_rules(ignored, file, &path))
+				goto cleanup;
+		}
+
+		/* last process global ignores */
+		git_vector_foreach(&ignores.ign_global, i, file) {
+			if (ignore_lookup_in_rules(ignored, file, &path))
+				goto cleanup;
+		}
+
+		/* move up one directory */
+		if (path.basename == path.path)
+			break;
+		path.basename[-1] = '\0';
+		while (path.basename > path.path && *path.basename != '/')
+			path.basename--;
+		if (path.basename > path.path)
+			path.basename++;
+		path.is_dir = 1;
+
+		if ((error = git_ignore__pop_dir(&ignores)) < 0)
+			break;
+	}
+
+	*ignored = 0;
+
+cleanup:
+	git_attr_path__free(&path);
+	git_ignore__free(&ignores);
+	return error;
+}
+
+int git_ignore__check_pathspec_for_exact_ignores(
+	git_repository *repo,
+	git_vector *vspec,
+	bool no_fnmatch)
+{
+	int error = 0;
+	size_t i;
+	git_attr_fnmatch *match;
+	int ignored;
+	git_buf path = GIT_BUF_INIT;
+	const char *wd, *filename;
+	git_index *idx;
+
+	if ((error = git_repository__ensure_not_bare(
+			repo, "validate pathspec")) < 0 ||
+		(error = git_repository_index(&idx, repo)) < 0)
+		return error;
+
+	wd = git_repository_workdir(repo);
+
+	git_vector_foreach(vspec, i, match) {
+		/* skip wildcard matches (if they are being used) */
+		if ((match->flags & GIT_ATTR_FNMATCH_HASWILD) != 0 &&
+			!no_fnmatch)
+			continue;
+
+		filename = match->pattern;
+
+		/* if file is already in the index, it's fine */
+		if (git_index_get_bypath(idx, filename, 0) != NULL)
+			continue;
+
+		if ((error = git_buf_joinpath(&path, wd, filename)) < 0)
+			break;
+
+		/* is there a file on disk that matches this exactly? */
+		if (!git_path_isfile(path.ptr))
+			continue;
+
+		/* is that file ignored? */
+		if ((error = git_ignore_path_is_ignored(&ignored, repo, filename)) < 0)
+			break;
+
+		if (ignored) {
+			giterr_set(GITERR_INVALID, "pathspec contains ignored file '%s'",
+				filename);
+			error = GIT_EINVALIDSPEC;
+			break;
+		}
+	}
+
+	git_index_free(idx);
+	git_buf_free(&path);
+
+	return error;
+}
+

vendor/libgit2-sys/libgit2/src/ignore.h

diff --git a/vendor/libgit2-sys/libgit2/src/ignore.h b/vendor/libgit2-sys/libgit2/src/ignore.h
new file mode 100644
index 0000000..5895d3f
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/ignore.h
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_ignore_h__
+#define INCLUDE_ignore_h__
+
+#include "common.h"
+
+#include "repository.h"
+#include "vector.h"
+#include "attr_file.h"
+
+#define GIT_IGNORE_FILE			".gitignore"
+#define GIT_IGNORE_FILE_INREPO	"exclude"
+#define GIT_IGNORE_FILE_XDG		"ignore"
+
+/* The git_ignores structure maintains three sets of ignores:
+ * - internal ignores
+ * - per directory ignores
+ * - global ignores (at lower priority than the others)
+ * As you traverse from one directory to another, you can push and pop
+ * directories onto git_ignores list efficiently.
+ */
+typedef struct {
+	git_repository *repo;
+	git_buf dir; /* current directory reflected in ign_path */
+	git_attr_file *ign_internal;
+	git_vector ign_path;
+	git_vector ign_global;
+	size_t dir_root; /* offset in dir to repo root */
+	int ignore_case;
+	int depth;
+} git_ignores;
+
+extern int git_ignore__for_path(
+	git_repository *repo, const char *path, git_ignores *ign);
+
+extern int git_ignore__push_dir(git_ignores *ign, const char *dir);
+
+extern int git_ignore__pop_dir(git_ignores *ign);
+
+extern void git_ignore__free(git_ignores *ign);
+
+enum {
+	GIT_IGNORE_UNCHECKED = -2,
+	GIT_IGNORE_NOTFOUND = -1,
+	GIT_IGNORE_FALSE = 0,
+	GIT_IGNORE_TRUE = 1,
+};
+
+extern int git_ignore__lookup(int *out, git_ignores *ign, const char *path, git_dir_flag dir_flag);
+
+/* command line Git sometimes generates an error message if given a
+ * pathspec that contains an exact match to an ignored file (provided
+ * --force isn't also given).  This makes it easy to check it that has
+ * happened.  Returns GIT_EINVALIDSPEC if the pathspec contains ignored
+ * exact matches (that are not already present in the index).
+ */
+extern int git_ignore__check_pathspec_for_exact_ignores(
+	git_repository *repo, git_vector *pathspec, bool no_fnmatch);
+
+#endif

vendor/libgit2-sys/libgit2/src/index.c

diff --git a/vendor/libgit2-sys/libgit2/src/index.c b/vendor/libgit2-sys/libgit2/src/index.c
new file mode 100644
index 0000000..09313eb
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/index.c
@@ -0,0 +1,3619 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "index.h"
+
+#include <stddef.h>
+
+#include "repository.h"
+#include "tree.h"
+#include "tree-cache.h"
+#include "hash.h"
+#include "iterator.h"
+#include "pathspec.h"
+#include "ignore.h"
+#include "blob.h"
+#include "idxmap.h"
+#include "diff.h"
+#include "varint.h"
+
+#include "git2/odb.h"
+#include "git2/oid.h"
+#include "git2/blob.h"
+#include "git2/config.h"
+#include "git2/sys/index.h"
+
+#define INSERT_IN_MAP_EX(idx, map, e, err) do {				\
+		if ((idx)->ignore_case)					\
+			git_idxmap_icase_insert((khash_t(idxicase) *) (map), (e), (e), (err)); \
+		else							\
+			git_idxmap_insert((map), (e), (e), (err));	\
+	} while (0)
+
+#define INSERT_IN_MAP(idx, e, err) INSERT_IN_MAP_EX(idx, (idx)->entries_map, e, err)
+
+#define LOOKUP_IN_MAP(p, idx, k) do {					\
+		if ((idx)->ignore_case)					\
+			(p) = git_idxmap_icase_lookup_index((khash_t(idxicase) *) index->entries_map, (k)); \
+		else							\
+			(p) = git_idxmap_lookup_index(index->entries_map, (k)); \
+	} while (0)
+
+#define DELETE_IN_MAP(idx, e) do {					\
+		if ((idx)->ignore_case)					\
+			git_idxmap_icase_delete((khash_t(idxicase) *) (idx)->entries_map, (e)); \
+		else							\
+			git_idxmap_delete((idx)->entries_map, (e));	\
+	} while (0)
+
+static int index_apply_to_wd_diff(git_index *index, int action, const git_strarray *paths,
+				  unsigned int flags,
+				  git_index_matched_path_cb cb, void *payload);
+
+#define minimal_entry_size (offsetof(struct entry_short, path))
+
+static const size_t INDEX_FOOTER_SIZE = GIT_OID_RAWSZ;
+static const size_t INDEX_HEADER_SIZE = 12;
+
+static const unsigned int INDEX_VERSION_NUMBER_DEFAULT = 2;
+static const unsigned int INDEX_VERSION_NUMBER_LB = 2;
+static const unsigned int INDEX_VERSION_NUMBER_EXT = 3;
+static const unsigned int INDEX_VERSION_NUMBER_COMP = 4;
+static const unsigned int INDEX_VERSION_NUMBER_UB = 4;
+
+static const unsigned int INDEX_HEADER_SIG = 0x44495243;
+static const char INDEX_EXT_TREECACHE_SIG[] = {'T', 'R', 'E', 'E'};
+static const char INDEX_EXT_UNMERGED_SIG[] = {'R', 'E', 'U', 'C'};
+static const char INDEX_EXT_CONFLICT_NAME_SIG[] = {'N', 'A', 'M', 'E'};
+
+#define INDEX_OWNER(idx) ((git_repository *)(GIT_REFCOUNT_OWNER(idx)))
+
+struct index_header {
+	uint32_t signature;
+	uint32_t version;
+	uint32_t entry_count;
+};
+
+struct index_extension {
+	char signature[4];
+	uint32_t extension_size;
+};
+
+struct entry_time {
+	uint32_t seconds;
+	uint32_t nanoseconds;
+};
+
+struct entry_short {
+	struct entry_time ctime;
+	struct entry_time mtime;
+	uint32_t dev;
+	uint32_t ino;
+	uint32_t mode;
+	uint32_t uid;
+	uint32_t gid;
+	uint32_t file_size;
+	git_oid oid;
+	uint16_t flags;
+	char path[1]; /* arbitrary length */
+};
+
+struct entry_long {
+	struct entry_time ctime;
+	struct entry_time mtime;
+	uint32_t dev;
+	uint32_t ino;
+	uint32_t mode;
+	uint32_t uid;
+	uint32_t gid;
+	uint32_t file_size;
+	git_oid oid;
+	uint16_t flags;
+	uint16_t flags_extended;
+	char path[1]; /* arbitrary length */
+};
+
+struct entry_srch_key {
+	const char *path;
+	size_t pathlen;
+	int stage;
+};
+
+struct entry_internal {
+	git_index_entry entry;
+	size_t pathlen;
+	char path[GIT_FLEX_ARRAY];
+};
+
+struct reuc_entry_internal {
+	git_index_reuc_entry entry;
+	size_t pathlen;
+	char path[GIT_FLEX_ARRAY];
+};
+
+/* local declarations */
+static size_t read_extension(git_index *index, const char *buffer, size_t buffer_size);
+static int read_header(struct index_header *dest, const void *buffer);
+
+static int parse_index(git_index *index, const char *buffer, size_t buffer_size);
+static bool is_index_extended(git_index *index);
+static int write_index(git_oid *checksum, git_index *index, git_filebuf *file);
+
+static void index_entry_free(git_index_entry *entry);
+static void index_entry_reuc_free(git_index_reuc_entry *reuc);
+
+int git_index_entry_srch(const void *key, const void *array_member)
+{
+	const struct entry_srch_key *srch_key = key;
+	const struct entry_internal *entry = array_member;
+	int cmp;
+	size_t len1, len2, len;
+
+	len1 = srch_key->pathlen;
+	len2 = entry->pathlen;
+	len = len1 < len2 ? len1 : len2;
+
+	cmp = memcmp(srch_key->path, entry->path, len);
+	if (cmp)
+		return cmp;
+	if (len1 < len2)
+		return -1;
+	if (len1 > len2)
+		return 1;
+
+	if (srch_key->stage != GIT_INDEX_STAGE_ANY)
+		return srch_key->stage - GIT_IDXENTRY_STAGE(&entry->entry);
+
+	return 0;
+}
+
+int git_index_entry_isrch(const void *key, const void *array_member)
+{
+	const struct entry_srch_key *srch_key = key;
+	const struct entry_internal *entry = array_member;
+	int cmp;
+	size_t len1, len2, len;
+
+	len1 = srch_key->pathlen;
+	len2 = entry->pathlen;
+	len = len1 < len2 ? len1 : len2;
+
+	cmp = strncasecmp(srch_key->path, entry->path, len);
+
+	if (cmp)
+		return cmp;
+	if (len1 < len2)
+		return -1;
+	if (len1 > len2)
+		return 1;
+
+	if (srch_key->stage != GIT_INDEX_STAGE_ANY)
+		return srch_key->stage - GIT_IDXENTRY_STAGE(&entry->entry);
+
+	return 0;
+}
+
+static int index_entry_srch_path(const void *path, const void *array_member)
+{
+	const git_index_entry *entry = array_member;
+
+	return strcmp((const char *)path, entry->path);
+}
+
+static int index_entry_isrch_path(const void *path, const void *array_member)
+{
+	const git_index_entry *entry = array_member;
+
+	return strcasecmp((const char *)path, entry->path);
+}
+
+int git_index_entry_cmp(const void *a, const void *b)
+{
+	int diff;
+	const git_index_entry *entry_a = a;
+	const git_index_entry *entry_b = b;
+
+	diff = strcmp(entry_a->path, entry_b->path);
+
+	if (diff == 0)
+		diff = (GIT_IDXENTRY_STAGE(entry_a) - GIT_IDXENTRY_STAGE(entry_b));
+
+	return diff;
+}
+
+int git_index_entry_icmp(const void *a, const void *b)
+{
+	int diff;
+	const git_index_entry *entry_a = a;
+	const git_index_entry *entry_b = b;
+
+	diff = strcasecmp(entry_a->path, entry_b->path);
+
+	if (diff == 0)
+		diff = (GIT_IDXENTRY_STAGE(entry_a) - GIT_IDXENTRY_STAGE(entry_b));
+
+	return diff;
+}
+
+static int conflict_name_cmp(const void *a, const void *b)
+{
+	const git_index_name_entry *name_a = a;
+	const git_index_name_entry *name_b = b;
+
+	if (name_a->ancestor && !name_b->ancestor)
+		return 1;
+
+	if (!name_a->ancestor && name_b->ancestor)
+		return -1;
+
+	if (name_a->ancestor)
+		return strcmp(name_a->ancestor, name_b->ancestor);
+
+	if (!name_a->ours || !name_b->ours)
+		return 0;
+
+	return strcmp(name_a->ours, name_b->ours);
+}
+
+/**
+ * TODO: enable this when resolving case insensitive conflicts
+ */
+#if 0
+static int conflict_name_icmp(const void *a, const void *b)
+{
+	const git_index_name_entry *name_a = a;
+	const git_index_name_entry *name_b = b;
+
+	if (name_a->ancestor && !name_b->ancestor)
+		return 1;
+
+	if (!name_a->ancestor && name_b->ancestor)
+		return -1;
+
+	if (name_a->ancestor)
+		return strcasecmp(name_a->ancestor, name_b->ancestor);
+
+	if (!name_a->ours || !name_b->ours)
+		return 0;
+
+	return strcasecmp(name_a->ours, name_b->ours);
+}
+#endif
+
+static int reuc_srch(const void *key, const void *array_member)
+{
+	const git_index_reuc_entry *reuc = array_member;
+
+	return strcmp(key, reuc->path);
+}
+
+static int reuc_isrch(const void *key, const void *array_member)
+{
+	const git_index_reuc_entry *reuc = array_member;
+
+	return strcasecmp(key, reuc->path);
+}
+
+static int reuc_cmp(const void *a, const void *b)
+{
+	const git_index_reuc_entry *info_a = a;
+	const git_index_reuc_entry *info_b = b;
+
+	return strcmp(info_a->path, info_b->path);
+}
+
+static int reuc_icmp(const void *a, const void *b)
+{
+	const git_index_reuc_entry *info_a = a;
+	const git_index_reuc_entry *info_b = b;
+
+	return strcasecmp(info_a->path, info_b->path);
+}
+
+static void index_entry_reuc_free(git_index_reuc_entry *reuc)
+{
+	git__free(reuc);
+}
+
+static void index_entry_free(git_index_entry *entry)
+{
+	if (!entry)
+		return;
+
+	memset(&entry->id, 0, sizeof(entry->id));
+	git__free(entry);
+}
+
+unsigned int git_index__create_mode(unsigned int mode)
+{
+	if (S_ISLNK(mode))
+		return S_IFLNK;
+
+	if (S_ISDIR(mode) || (mode & S_IFMT) == (S_IFLNK | S_IFDIR))
+		return (S_IFLNK | S_IFDIR);
+
+	return S_IFREG | GIT_PERMS_CANONICAL(mode);
+}
+
+static unsigned int index_merge_mode(
+	git_index *index, git_index_entry *existing, unsigned int mode)
+{
+	if (index->no_symlinks && S_ISREG(mode) &&
+		existing && S_ISLNK(existing->mode))
+		return existing->mode;
+
+	if (index->distrust_filemode && S_ISREG(mode))
+		return (existing && S_ISREG(existing->mode)) ?
+			existing->mode : git_index__create_mode(0666);
+
+	return git_index__create_mode(mode);
+}
+
+GIT_INLINE(int) index_find_in_entries(
+	size_t *out, git_vector *entries, git_vector_cmp entry_srch,
+	const char *path, size_t path_len, int stage)
+{
+	struct entry_srch_key srch_key;
+	srch_key.path = path;
+	srch_key.pathlen = !path_len ? strlen(path) : path_len;
+	srch_key.stage = stage;
+	return git_vector_bsearch2(out, entries, entry_srch, &srch_key);
+}
+
+GIT_INLINE(int) index_find(
+	size_t *out, git_index *index,
+	const char *path, size_t path_len, int stage)
+{
+	git_vector_sort(&index->entries);
+
+	return index_find_in_entries(
+		out, &index->entries, index->entries_search, path, path_len, stage);
+}
+
+void git_index__set_ignore_case(git_index *index, bool ignore_case)
+{
+	index->ignore_case = ignore_case;
+
+	if (ignore_case) {
+		index->entries_cmp_path    = git__strcasecmp_cb;
+		index->entries_search      = git_index_entry_isrch;
+		index->entries_search_path = index_entry_isrch_path;
+		index->reuc_search         = reuc_isrch;
+	} else {
+		index->entries_cmp_path    = git__strcmp_cb;
+		index->entries_search      = git_index_entry_srch;
+		index->entries_search_path = index_entry_srch_path;
+		index->reuc_search         = reuc_srch;
+	}
+
+	git_vector_set_cmp(&index->entries,
+		ignore_case ? git_index_entry_icmp : git_index_entry_cmp);
+	git_vector_sort(&index->entries);
+
+	git_vector_set_cmp(&index->reuc, ignore_case ? reuc_icmp : reuc_cmp);
+	git_vector_sort(&index->reuc);
+}
+
+int git_index_open(git_index **index_out, const char *index_path)
+{
+	git_index *index;
+	int error = -1;
+
+	assert(index_out);
+
+	index = git__calloc(1, sizeof(git_index));
+	GITERR_CHECK_ALLOC(index);
+
+	git_pool_init(&index->tree_pool, 1);
+
+	if (index_path != NULL) {
+		index->index_file_path = git__strdup(index_path);
+		if (!index->index_file_path)
+			goto fail;
+
+		/* Check if index file is stored on disk already */
+		if (git_path_exists(index->index_file_path) == true)
+			index->on_disk = 1;
+	}
+
+	if (git_vector_init(&index->entries, 32, git_index_entry_cmp) < 0 ||
+		git_idxmap_alloc(&index->entries_map) < 0 ||
+		git_vector_init(&index->names, 8, conflict_name_cmp) < 0 ||
+		git_vector_init(&index->reuc, 8, reuc_cmp) < 0 ||
+		git_vector_init(&index->deleted, 8, git_index_entry_cmp) < 0)
+		goto fail;
+
+	index->entries_cmp_path = git__strcmp_cb;
+	index->entries_search = git_index_entry_srch;
+	index->entries_search_path = index_entry_srch_path;
+	index->reuc_search = reuc_srch;
+	index->version = INDEX_VERSION_NUMBER_DEFAULT;
+
+	if (index_path != NULL && (error = git_index_read(index, true)) < 0)
+		goto fail;
+
+	*index_out = index;
+	GIT_REFCOUNT_INC(index);
+
+	return 0;
+
+fail:
+	git_pool_clear(&index->tree_pool);
+	git_index_free(index);
+	return error;
+}
+
+int git_index_new(git_index **out)
+{
+	return git_index_open(out, NULL);
+}
+
+static void index_free(git_index *index)
+{
+	/* index iterators increment the refcount of the index, so if we
+	 * get here then there should be no outstanding iterators.
+	 */
+	assert(!git_atomic_get(&index->readers));
+
+	git_index_clear(index);
+	git_idxmap_free(index->entries_map);
+	git_vector_free(&index->entries);
+	git_vector_free(&index->names);
+	git_vector_free(&index->reuc);
+	git_vector_free(&index->deleted);
+
+	git__free(index->index_file_path);
+
+	git__memzero(index, sizeof(*index));
+	git__free(index);
+}
+
+void git_index_free(git_index *index)
+{
+	if (index == NULL)
+		return;
+
+	GIT_REFCOUNT_DEC(index, index_free);
+}
+
+/* call with locked index */
+static void index_free_deleted(git_index *index)
+{
+	int readers = (int)git_atomic_get(&index->readers);
+	size_t i;
+
+	if (readers > 0 || !index->deleted.length)
+		return;
+
+	for (i = 0; i < index->deleted.length; ++i) {
+		git_index_entry *ie = git__swap(index->deleted.contents[i], NULL);
+		index_entry_free(ie);
+	}
+
+	git_vector_clear(&index->deleted);
+}
+
+/* call with locked index */
+static int index_remove_entry(git_index *index, size_t pos)
+{
+	int error = 0;
+	git_index_entry *entry = git_vector_get(&index->entries, pos);
+
+	if (entry != NULL) {
+		git_tree_cache_invalidate_path(index->tree, entry->path);
+		DELETE_IN_MAP(index, entry);
+	}
+
+	error = git_vector_remove(&index->entries, pos);
+
+	if (!error) {
+		if (git_atomic_get(&index->readers) > 0) {
+			error = git_vector_insert(&index->deleted, entry);
+		} else {
+			index_entry_free(entry);
+		}
+	}
+
+	return error;
+}
+
+int git_index_clear(git_index *index)
+{
+	int error = 0;
+
+	assert(index);
+
+	index->tree = NULL;
+	git_pool_clear(&index->tree_pool);
+
+	git_idxmap_clear(index->entries_map);
+	while (!error && index->entries.length > 0)
+		error = index_remove_entry(index, index->entries.length - 1);
+	index_free_deleted(index);
+
+	git_index_reuc_clear(index);
+	git_index_name_clear(index);
+
+	git_futils_filestamp_set(&index->stamp, NULL);
+
+	return error;
+}
+
+static int create_index_error(int error, const char *msg)
+{
+	giterr_set_str(GITERR_INDEX, msg);
+	return error;
+}
+
+int git_index_set_caps(git_index *index, int caps)
+{
+	unsigned int old_ignore_case;
+
+	assert(index);
+
+	old_ignore_case = index->ignore_case;
+
+	if (caps == GIT_INDEXCAP_FROM_OWNER) {
+		git_repository *repo = INDEX_OWNER(index);
+		int val;
+
+		if (!repo)
+			return create_index_error(
+				-1, "cannot access repository to set index caps");
+
+		if (!git_repository__cvar(&val, repo, GIT_CVAR_IGNORECASE))
+			index->ignore_case = (val != 0);
+		if (!git_repository__cvar(&val, repo, GIT_CVAR_FILEMODE))
+			index->distrust_filemode = (val == 0);
+		if (!git_repository__cvar(&val, repo, GIT_CVAR_SYMLINKS))
+			index->no_symlinks = (val == 0);
+	}
+	else {
+		index->ignore_case = ((caps & GIT_INDEXCAP_IGNORE_CASE) != 0);
+		index->distrust_filemode = ((caps & GIT_INDEXCAP_NO_FILEMODE) != 0);
+		index->no_symlinks = ((caps & GIT_INDEXCAP_NO_SYMLINKS) != 0);
+	}
+
+	if (old_ignore_case != index->ignore_case) {
+		git_index__set_ignore_case(index, (bool)index->ignore_case);
+	}
+
+	return 0;
+}
+
+int git_index_caps(const git_index *index)
+{
+	return ((index->ignore_case ? GIT_INDEXCAP_IGNORE_CASE : 0) |
+			(index->distrust_filemode ? GIT_INDEXCAP_NO_FILEMODE : 0) |
+			(index->no_symlinks ? GIT_INDEXCAP_NO_SYMLINKS : 0));
+}
+
+const git_oid *git_index_checksum(git_index *index)
+{
+	return &index->checksum;
+}
+
+/**
+ * Returns 1 for changed, 0 for not changed and <0 for errors
+ */
+static int compare_checksum(git_index *index)
+{
+	int fd;
+	ssize_t bytes_read;
+	git_oid checksum = {{ 0 }};
+
+	if ((fd = p_open(index->index_file_path, O_RDONLY)) < 0)
+		return fd;
+
+	if (p_lseek(fd, -20, SEEK_END) < 0) {
+		p_close(fd);
+		giterr_set(GITERR_OS, "failed to seek to end of file");
+		return -1;
+	}
+
+	bytes_read = p_read(fd, &checksum, GIT_OID_RAWSZ);
+	p_close(fd);
+
+	if (bytes_read < 0)
+		return -1;
+
+	return !!git_oid_cmp(&checksum, &index->checksum);
+}
+
+int git_index_read(git_index *index, int force)
+{
+	int error = 0, updated;
+	git_buf buffer = GIT_BUF_INIT;
+	git_futils_filestamp stamp = index->stamp;
+
+	if (!index->index_file_path)
+		return create_index_error(-1,
+			"failed to read index: The index is in-memory only");
+
+	index->on_disk = git_path_exists(index->index_file_path);
+
+	if (!index->on_disk) {
+		if (force)
+			return git_index_clear(index);
+		return 0;
+	}
+
+	if ((updated = git_futils_filestamp_check(&stamp, index->index_file_path) < 0) ||
+	    ((updated = compare_checksum(index)) < 0)) {
+		giterr_set(
+			GITERR_INDEX,
+			"failed to read index: '%s' no longer exists",
+			index->index_file_path);
+		return updated;
+	}
+	if (!updated && !force)
+		return 0;
+
+	error = git_futils_readbuffer(&buffer, index->index_file_path);
+	if (error < 0)
+		return error;
+
+	index->tree = NULL;
+	git_pool_clear(&index->tree_pool);
+
+	error = git_index_clear(index);
+
+	if (!error)
+		error = parse_index(index, buffer.ptr, buffer.size);
+
+	if (!error)
+		git_futils_filestamp_set(&index->stamp, &stamp);
+
+	git_buf_free(&buffer);
+	return error;
+}
+
+int git_index__changed_relative_to(
+	git_index *index, const git_oid *checksum)
+{
+	/* attempt to update index (ignoring errors) */
+	if (git_index_read(index, false) < 0)
+		giterr_clear();
+
+	return !!git_oid_cmp(&index->checksum, checksum);
+}
+
+static bool is_racy_entry(git_index *index, const git_index_entry *entry)
+{
+	/* Git special-cases submodules in the check */
+	if (S_ISGITLINK(entry->mode))
+		return false;
+
+	return git_index_entry_newer_than_index(entry, index);
+}
+
+/*
+ * Force the next diff to take a look at those entries which have the
+ * same timestamp as the current index.
+ */
+static int truncate_racily_clean(git_index *index)
+{
+	size_t i;
+	int error;
+	git_index_entry *entry;
+	git_diff_options diff_opts = GIT_DIFF_OPTIONS_INIT;
+	git_diff *diff = NULL;
+	git_vector paths = GIT_VECTOR_INIT;
+	git_diff_delta *delta;
+
+	/* Nothing to do if there's no repo to talk about */
+	if (!INDEX_OWNER(index))
+		return 0;
+
+	/* If there's no workdir, we can't know where to even check */
+	if (!git_repository_workdir(INDEX_OWNER(index)))
+		return 0;
+
+	diff_opts.flags |= GIT_DIFF_INCLUDE_TYPECHANGE | GIT_DIFF_IGNORE_SUBMODULES | GIT_DIFF_DISABLE_PATHSPEC_MATCH;
+	git_vector_foreach(&index->entries, i, entry) {
+		if ((entry->flags_extended & GIT_IDXENTRY_UPTODATE) == 0 &&
+			is_racy_entry(index, entry))
+			git_vector_insert(&paths, (char *)entry->path);
+	}
+
+	if (paths.length == 0)
+		goto done;
+
+	diff_opts.pathspec.count = paths.length;
+	diff_opts.pathspec.strings = (char **)paths.contents;
+
+	if ((error = git_diff_index_to_workdir(&diff, INDEX_OWNER(index), index, &diff_opts)) < 0)
+		return error;
+
+	git_vector_foreach(&diff->deltas, i, delta) {
+		entry = (git_index_entry *)git_index_get_bypath(index, delta->old_file.path, 0);
+
+		/* Ensure that we have a stage 0 for this file (ie, it's not a
+		 * conflict), otherwise smudging it is quite pointless.
+		 */
+		if (entry)
+			entry->file_size = 0;
+	}
+
+done:
+	git_diff_free(diff);
+	git_vector_free(&paths);
+	return 0;
+}
+
+unsigned git_index_version(git_index *index)
+{
+	assert(index);
+
+	return index->version;
+}
+
+int git_index_set_version(git_index *index, unsigned int version)
+{
+	assert(index);
+
+	if (version < INDEX_VERSION_NUMBER_LB ||
+	    version > INDEX_VERSION_NUMBER_UB) {
+		giterr_set(GITERR_INDEX, "invalid version number");
+		return -1;
+	}
+
+	index->version = version;
+
+	return 0;
+}
+
+int git_index_write(git_index *index)
+{
+	git_indexwriter writer = GIT_INDEXWRITER_INIT;
+	int error;
+
+	truncate_racily_clean(index);
+
+	if ((error = git_indexwriter_init(&writer, index)) == 0)
+		error = git_indexwriter_commit(&writer);
+
+	git_indexwriter_cleanup(&writer);
+
+	return error;
+}
+
+const char * git_index_path(const git_index *index)
+{
+	assert(index);
+	return index->index_file_path;
+}
+
+int git_index_write_tree(git_oid *oid, git_index *index)
+{
+	git_repository *repo;
+
+	assert(oid && index);
+
+	repo = INDEX_OWNER(index);
+
+	if (repo == NULL)
+		return create_index_error(-1, "Failed to write tree. "
+		  "the index file is not backed up by an existing repository");
+
+	return git_tree__write_index(oid, index, repo);
+}
+
+int git_index_write_tree_to(
+	git_oid *oid, git_index *index, git_repository *repo)
+{
+	assert(oid && index && repo);
+	return git_tree__write_index(oid, index, repo);
+}
+
+size_t git_index_entrycount(const git_index *index)
+{
+	assert(index);
+	return index->entries.length;
+}
+
+const git_index_entry *git_index_get_byindex(
+	git_index *index, size_t n)
+{
+	assert(index);
+	git_vector_sort(&index->entries);
+	return git_vector_get(&index->entries, n);
+}
+
+const git_index_entry *git_index_get_bypath(
+	git_index *index, const char *path, int stage)
+{
+	khiter_t pos;
+	git_index_entry key = {{ 0 }};
+
+	assert(index);
+
+	key.path = path;
+	GIT_IDXENTRY_STAGE_SET(&key, stage);
+
+	LOOKUP_IN_MAP(pos, index, &key);
+
+	if (git_idxmap_valid_index(index->entries_map, pos))
+		return git_idxmap_value_at(index->entries_map, pos);
+
+	giterr_set(GITERR_INDEX, "index does not contain '%s'", path);
+	return NULL;
+}
+
+void git_index_entry__init_from_stat(
+	git_index_entry *entry, struct stat *st, bool trust_mode)
+{
+	entry->ctime.seconds = (int32_t)st->st_ctime;
+	entry->mtime.seconds = (int32_t)st->st_mtime;
+#if defined(GIT_USE_NSEC)
+	entry->mtime.nanoseconds = st->st_mtime_nsec;
+	entry->ctime.nanoseconds = st->st_ctime_nsec;
+#endif
+	entry->dev  = st->st_rdev;
+	entry->ino  = st->st_ino;
+	entry->mode = (!trust_mode && S_ISREG(st->st_mode)) ?
+		git_index__create_mode(0666) : git_index__create_mode(st->st_mode);
+	entry->uid  = st->st_uid;
+	entry->gid  = st->st_gid;
+	entry->file_size = (uint32_t)st->st_size;
+}
+
+static void index_entry_adjust_namemask(
+		git_index_entry *entry,
+		size_t path_length)
+{
+	entry->flags &= ~GIT_IDXENTRY_NAMEMASK;
+
+	if (path_length < GIT_IDXENTRY_NAMEMASK)
+		entry->flags |= path_length & GIT_IDXENTRY_NAMEMASK;
+	else
+		entry->flags |= GIT_IDXENTRY_NAMEMASK;
+}
+
+/* When `from_workdir` is true, we will validate the paths to avoid placing
+ * paths that are invalid for the working directory on the current filesystem
+ * (eg, on Windows, we will disallow `GIT~1`, `AUX`, `COM1`, etc).  This
+ * function will *always* prevent `.git` and directory traversal `../` from
+ * being added to the index.
+ */
+static int index_entry_create(
+	git_index_entry **out,
+	git_repository *repo,
+	const char *path,
+	struct stat *st,
+	bool from_workdir)
+{
+	size_t pathlen = strlen(path), alloclen;
+	struct entry_internal *entry;
+	unsigned int path_valid_flags = GIT_PATH_REJECT_INDEX_DEFAULTS;
+	uint16_t mode = 0;
+
+	/* always reject placing `.git` in the index and directory traversal.
+	 * when requested, disallow platform-specific filenames and upgrade to
+	 * the platform-specific `.git` tests (eg, `git~1`, etc).
+	 */
+	if (from_workdir)
+		path_valid_flags |= GIT_PATH_REJECT_WORKDIR_DEFAULTS;
+	if (st)
+		mode = st->st_mode;
+
+	if (!git_path_isvalid(repo, path, mode, path_valid_flags)) {
+		giterr_set(GITERR_INDEX, "invalid path: '%s'", path);
+		return -1;
+	}
+
+	GITERR_CHECK_ALLOC_ADD(&alloclen, sizeof(struct entry_internal), pathlen);
+	GITERR_CHECK_ALLOC_ADD(&alloclen, alloclen, 1);
+	entry = git__calloc(1, alloclen);
+	GITERR_CHECK_ALLOC(entry);
+
+	entry->pathlen = pathlen;
+	memcpy(entry->path, path, pathlen);
+	entry->entry.path = entry->path;
+
+	*out = (git_index_entry *)entry;
+	return 0;
+}
+
+static int index_entry_init(
+	git_index_entry **entry_out,
+	git_index *index,
+	const char *rel_path)
+{
+	int error = 0;
+	git_index_entry *entry = NULL;
+	git_buf path = GIT_BUF_INIT;
+	struct stat st;
+	git_oid oid;
+	git_repository *repo;
+
+	if (INDEX_OWNER(index) == NULL)
+		return create_index_error(-1,
+			"could not initialize index entry. "
+			"Index is not backed up by an existing repository.");
+
+	/*
+	 * FIXME: this is duplicated with the work in
+	 * git_blob__create_from_paths. It should accept an optional stat
+	 * structure so we can pass in the one we have to do here.
+	 */
+	repo = INDEX_OWNER(index);
+	if (git_repository__ensure_not_bare(repo, "create blob from file") < 0)
+		return GIT_EBAREREPO;
+
+	if (git_buf_joinpath(&path, git_repository_workdir(repo), rel_path) < 0)
+		return -1;
+
+	error = git_path_lstat(path.ptr, &st);
+	git_buf_free(&path);
+
+	if (error < 0)
+		return error;
+
+	if (index_entry_create(&entry, INDEX_OWNER(index), rel_path, &st, true) < 0)
+		return -1;
+
+	/* write the blob to disk and get the oid and stat info */
+	error = git_blob__create_from_paths(
+		&oid, &st, INDEX_OWNER(index), NULL, rel_path, 0, true);
+
+	if (error < 0) {
+		index_entry_free(entry);
+		return error;
+	}
+
+	entry->id = oid;
+	git_index_entry__init_from_stat(entry, &st, !index->distrust_filemode);
+
+	*entry_out = (git_index_entry *)entry;
+	return 0;
+}
+
+static git_index_reuc_entry *reuc_entry_alloc(const char *path)
+{
+	size_t pathlen = strlen(path),
+		structlen = sizeof(struct reuc_entry_internal),
+		alloclen;
+	struct reuc_entry_internal *entry;
+
+	if (GIT_ADD_SIZET_OVERFLOW(&alloclen, structlen, pathlen) ||
+		GIT_ADD_SIZET_OVERFLOW(&alloclen, alloclen, 1))
+		return NULL;
+
+	entry = git__calloc(1, alloclen);
+	if (!entry)
+		return NULL;
+
+	entry->pathlen = pathlen;
+	memcpy(entry->path, path, pathlen);
+	entry->entry.path = entry->path;
+
+	return (git_index_reuc_entry *)entry;
+}
+
+static int index_entry_reuc_init(git_index_reuc_entry **reuc_out,
+	const char *path,
+	int ancestor_mode, const git_oid *ancestor_oid,
+	int our_mode, const git_oid *our_oid,
+	int their_mode, const git_oid *their_oid)
+{
+	git_index_reuc_entry *reuc = NULL;
+
+	assert(reuc_out && path);
+
+	*reuc_out = reuc = reuc_entry_alloc(path);
+	GITERR_CHECK_ALLOC(reuc);
+
+	if ((reuc->mode[0] = ancestor_mode) > 0) {
+		assert(ancestor_oid);
+		git_oid_cpy(&reuc->oid[0], ancestor_oid);
+	}
+
+	if ((reuc->mode[1] = our_mode) > 0) {
+		assert(our_oid);
+		git_oid_cpy(&reuc->oid[1], our_oid);
+	}
+
+	if ((reuc->mode[2] = their_mode) > 0) {
+		assert(their_oid);
+		git_oid_cpy(&reuc->oid[2], their_oid);
+	}
+
+	return 0;
+}
+
+static void index_entry_cpy(
+	git_index_entry *tgt,
+	const git_index_entry *src)
+{
+	const char *tgt_path = tgt->path;
+	memcpy(tgt, src, sizeof(*tgt));
+	tgt->path = tgt_path;
+}
+
+static int index_entry_dup(
+	git_index_entry **out,
+	git_index *index,
+	const git_index_entry *src)
+{
+	if (index_entry_create(out, INDEX_OWNER(index), src->path, NULL, false) < 0)
+		return -1;
+
+	index_entry_cpy(*out, src);
+	return 0;
+}
+
+static void index_entry_cpy_nocache(
+	git_index_entry *tgt,
+	const git_index_entry *src)
+{
+	git_oid_cpy(&tgt->id, &src->id);
+	tgt->mode = src->mode;
+	tgt->flags = src->flags;
+	tgt->flags_extended = (src->flags_extended & GIT_IDXENTRY_EXTENDED_FLAGS);
+}
+
+static int index_entry_dup_nocache(
+	git_index_entry **out,
+	git_index *index,
+	const git_index_entry *src)
+{
+	if (index_entry_create(out, INDEX_OWNER(index), src->path, NULL, false) < 0)
+		return -1;
+
+	index_entry_cpy_nocache(*out, src);
+	return 0;
+}
+
+static int has_file_name(git_index *index,
+	 const git_index_entry *entry, size_t pos, int ok_to_replace)
+{
+	int retval = 0;
+	size_t len = strlen(entry->path);
+	int stage = GIT_IDXENTRY_STAGE(entry);
+	const char *name = entry->path;
+
+	while (pos < index->entries.length) {
+		struct entry_internal *p = index->entries.contents[pos++];
+
+		if (len >= p->pathlen)
+			break;
+		if (memcmp(name, p->path, len))
+			break;
+		if (GIT_IDXENTRY_STAGE(&p->entry) != stage)
+			continue;
+		if (p->path[len] != '/')
+			continue;
+		retval = -1;
+		if (!ok_to_replace)
+			break;
+
+		if (index_remove_entry(index, --pos) < 0)
+			break;
+	}
+	return retval;
+}
+
+/*
+ * Do we have another file with a pathname that is a proper
+ * subset of the name we're trying to add?
+ */
+static int has_dir_name(git_index *index,
+		const git_index_entry *entry, int ok_to_replace)
+{
+	int retval = 0;
+	int stage = GIT_IDXENTRY_STAGE(entry);
+	const char *name = entry->path;
+	const char *slash = name + strlen(name);
+
+	for (;;) {
+		size_t len, pos;
+
+		for (;;) {
+			if (*--slash == '/')
+				break;
+			if (slash <= entry->path)
+				return retval;
+		}
+		len = slash - name;
+
+		if (!index_find(&pos, index, name, len, stage)) {
+			retval = -1;
+			if (!ok_to_replace)
+				break;
+
+			if (index_remove_entry(index, pos) < 0)
+				break;
+			continue;
+		}
+
+		/*
+		 * Trivial optimization: if we find an entry that
+		 * already matches the sub-directory, then we know
+		 * we're ok, and we can exit.
+		 */
+		for (; pos < index->entries.length; ++pos) {
+			struct entry_internal *p = index->entries.contents[pos];
+
+			if (p->pathlen <= len ||
+			    p->path[len] != '/' ||
+			    memcmp(p->path, name, len))
+				break; /* not our subdirectory */
+
+			if (GIT_IDXENTRY_STAGE(&p->entry) == stage)
+				return retval;
+		}
+	}
+
+	return retval;
+}
+
+static int check_file_directory_collision(git_index *index,
+		git_index_entry *entry, size_t pos, int ok_to_replace)
+{
+	int retval = has_file_name(index, entry, pos, ok_to_replace);
+	retval = retval + has_dir_name(index, entry, ok_to_replace);
+
+	if (retval) {
+		giterr_set(GITERR_INDEX,
+			"'%s' appears as both a file and a directory", entry->path);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int canonicalize_directory_path(
+	git_index *index,
+	git_index_entry *entry,
+	git_index_entry *existing)
+{
+	const git_index_entry *match, *best = NULL;
+	char *search, *sep;
+	size_t pos, search_len, best_len;
+
+	if (!index->ignore_case)
+		return 0;
+
+	/* item already exists in the index, simply re-use the existing case */
+	if (existing) {
+		memcpy((char *)entry->path, existing->path, strlen(existing->path));
+		return 0;
+	}
+
+	/* nothing to do */
+	if (strchr(entry->path, '/') == NULL)
+		return 0;
+
+	if ((search = git__strdup(entry->path)) == NULL)
+		return -1;
+
+	/* starting at the parent directory and descending to the root, find the
+	 * common parent directory.
+	 */
+	while (!best && (sep = strrchr(search, '/'))) {
+		sep[1] = '\0';
+
+		search_len = strlen(search);
+
+		git_vector_bsearch2(
+			&pos, &index->entries, index->entries_search_path, search);
+
+		while ((match = git_vector_get(&index->entries, pos))) {
+			if (GIT_IDXENTRY_STAGE(match) != 0) {
+				/* conflicts do not contribute to canonical paths */
+			} else if (strncmp(search, match->path, search_len) == 0) {
+				/* prefer an exact match to the input filename */
+				best = match;
+				best_len = search_len;
+				break;
+			} else if (strncasecmp(search, match->path, search_len) == 0) {
+				/* continue walking, there may be a path with an exact
+				 * (case sensitive) match later in the index, but use this
+				 * as the best match until that happens.
+				 */
+				if (!best) {
+					best = match;
+					best_len = search_len;
+				}
+			} else {
+				break;
+			}
+
+			pos++;
+		}
+
+		sep[0] = '\0';
+	}
+
+	if (best)
+		memcpy((char *)entry->path, best->path, best_len);
+
+	git__free(search);
+	return 0;
+}
+
+static int index_no_dups(void **old, void *new)
+{
+	const git_index_entry *entry = new;
+	GIT_UNUSED(old);
+	giterr_set(GITERR_INDEX, "'%s' appears multiple times at stage %d",
+		entry->path, GIT_IDXENTRY_STAGE(entry));
+	return GIT_EEXISTS;
+}
+
+static void index_existing_and_best(
+	git_index_entry **existing,
+	size_t *existing_position,
+	git_index_entry **best,
+	git_index *index,
+	const git_index_entry *entry)
+{
+	git_index_entry *e;
+	size_t pos;
+	int error;
+
+	error = index_find(&pos,
+		index, entry->path, 0, GIT_IDXENTRY_STAGE(entry));
+
+	if (error == 0) {
+		*existing = index->entries.contents[pos];
+		*existing_position = pos;
+		*best = index->entries.contents[pos];
+		return;
+	}
+
+	*existing = NULL;
+	*existing_position = 0;
+	*best = NULL;
+
+	if (GIT_IDXENTRY_STAGE(entry) == 0) {
+		for (; pos < index->entries.length; pos++) {
+			int (*strcomp)(const char *a, const char *b) =
+				index->ignore_case ? git__strcasecmp : git__strcmp;
+
+			e = index->entries.contents[pos];
+
+			if (strcomp(entry->path, e->path) != 0)
+				break;
+
+			if (GIT_IDXENTRY_STAGE(e) == GIT_INDEX_STAGE_ANCESTOR) {
+				*best = e;
+				continue;
+			} else {
+				*best = e;
+				break;
+			}
+		}
+	}
+}
+
+/* index_insert takes ownership of the new entry - if it can't insert
+ * it, then it will return an error **and also free the entry**.  When
+ * it replaces an existing entry, it will update the entry_ptr with the
+ * actual entry in the index (and free the passed in one).
+ *
+ * trust_path is whether we use the given path, or whether (on case
+ * insensitive systems only) we try to canonicalize the given path to
+ * be within an existing directory.
+ *
+ * trust_mode is whether we trust the mode in entry_ptr.
+ *
+ * trust_id is whether we trust the id or it should be validated.
+ */
+static int index_insert(
+	git_index *index,
+	git_index_entry **entry_ptr,
+	int replace,
+	bool trust_path,
+	bool trust_mode,
+	bool trust_id)
+{
+	int error = 0;
+	size_t path_length, position;
+	git_index_entry *existing, *best, *entry;
+
+	assert(index && entry_ptr);
+
+	entry = *entry_ptr;
+
+	/* make sure that the path length flag is correct */
+	path_length = ((struct entry_internal *)entry)->pathlen;
+	index_entry_adjust_namemask(entry, path_length);
+
+	/* this entry is now up-to-date and should not be checked for raciness */
+	entry->flags_extended |= GIT_IDXENTRY_UPTODATE;
+
+	git_vector_sort(&index->entries);
+
+	/* look if an entry with this path already exists, either staged, or (if
+	 * this entry is a regular staged item) as the "ours" side of a conflict.
+	 */
+	index_existing_and_best(&existing, &position, &best, index, entry);
+
+	/* update the file mode */
+	entry->mode = trust_mode ?
+		git_index__create_mode(entry->mode) :
+		index_merge_mode(index, best, entry->mode);
+
+	/* canonicalize the directory name */
+	if (!trust_path)
+		error = canonicalize_directory_path(index, entry, best);
+
+	/* ensure that the given id exists (unless it's a submodule) */
+	if (!error && !trust_id && INDEX_OWNER(index) &&
+		(entry->mode & GIT_FILEMODE_COMMIT) != GIT_FILEMODE_COMMIT) {
+
+		if (!git_object__is_valid(INDEX_OWNER(index), &entry->id,
+			git_object__type_from_filemode(entry->mode)))
+			error = -1;
+	}
+
+	/* look for tree / blob name collisions, removing conflicts if requested */
+	if (!error)
+		error = check_file_directory_collision(index, entry, position, replace);
+
+	if (error < 0)
+		/* skip changes */;
+
+	/* if we are replacing an existing item, overwrite the existing entry
+	 * and return it in place of the passed in one.
+	 */
+	else if (existing) {
+		if (replace) {
+			index_entry_cpy(existing, entry);
+
+			if (trust_path)
+				memcpy((char *)existing->path, entry->path, strlen(entry->path));
+		}
+
+		index_entry_free(entry);
+		*entry_ptr = entry = existing;
+	}
+	else {
+		/* if replace is not requested or no existing entry exists, insert
+		 * at the sorted position.  (Since we re-sort after each insert to
+		 * check for dups, this is actually cheaper in the long run.)
+		 */
+		error = git_vector_insert_sorted(&index->entries, entry, index_no_dups);
+
+		if (error == 0) {
+			INSERT_IN_MAP(index, entry, &error);
+		}
+	}
+
+	if (error < 0) {
+		index_entry_free(*entry_ptr);
+		*entry_ptr = NULL;
+	}
+
+	return error;
+}
+
+static int index_conflict_to_reuc(git_index *index, const char *path)
+{
+	const git_index_entry *conflict_entries[3];
+	int ancestor_mode, our_mode, their_mode;
+	git_oid const *ancestor_oid, *our_oid, *their_oid;
+	int ret;
+
+	if ((ret = git_index_conflict_get(&conflict_entries[0],
+		&conflict_entries[1], &conflict_entries[2], index, path)) < 0)
+		return ret;
+
+	ancestor_mode = conflict_entries[0] == NULL ? 0 : conflict_entries[0]->mode;
+	our_mode = conflict_entries[1] == NULL ? 0 : conflict_entries[1]->mode;
+	their_mode = conflict_entries[2] == NULL ? 0 : conflict_entries[2]->mode;
+
+	ancestor_oid = conflict_entries[0] == NULL ? NULL : &conflict_entries[0]->id;
+	our_oid = conflict_entries[1] == NULL ? NULL : &conflict_entries[1]->id;
+	their_oid = conflict_entries[2] == NULL ? NULL : &conflict_entries[2]->id;
+
+	if ((ret = git_index_reuc_add(index, path, ancestor_mode, ancestor_oid,
+		our_mode, our_oid, their_mode, their_oid)) >= 0)
+		ret = git_index_conflict_remove(index, path);
+
+	return ret;
+}
+
+GIT_INLINE(bool) is_file_or_link(const int filemode)
+{
+	return (filemode == GIT_FILEMODE_BLOB ||
+		filemode == GIT_FILEMODE_BLOB_EXECUTABLE ||
+		filemode == GIT_FILEMODE_LINK);
+}
+
+GIT_INLINE(bool) valid_filemode(const int filemode)
+{
+	return (is_file_or_link(filemode) || filemode == GIT_FILEMODE_COMMIT);
+}
+
+int git_index_add_frombuffer(
+    git_index *index, const git_index_entry *source_entry,
+    const void *buffer, size_t len)
+{
+	git_index_entry *entry = NULL;
+	int error = 0;
+	git_oid id;
+
+	assert(index && source_entry->path);
+
+	if (INDEX_OWNER(index) == NULL)
+		return create_index_error(-1,
+			"could not initialize index entry. "
+			"Index is not backed up by an existing repository.");
+
+	if (!is_file_or_link(source_entry->mode)) {
+		giterr_set(GITERR_INDEX, "invalid filemode");
+		return -1;
+	}
+
+	if (index_entry_dup(&entry, index, source_entry) < 0)
+		return -1;
+
+	error = git_blob_create_frombuffer(&id, INDEX_OWNER(index), buffer, len);
+	if (error < 0) {
+		index_entry_free(entry);
+		return error;
+	}
+
+	git_oid_cpy(&entry->id, &id);
+	entry->file_size = len;
+
+	if ((error = index_insert(index, &entry, 1, true, true, true)) < 0)
+		return error;
+
+	/* Adding implies conflict was resolved, move conflict entries to REUC */
+	if ((error = index_conflict_to_reuc(index, entry->path)) < 0 && error != GIT_ENOTFOUND)
+		return error;
+
+	git_tree_cache_invalidate_path(index->tree, entry->path);
+	return 0;
+}
+
+static int add_repo_as_submodule(git_index_entry **out, git_index *index, const char *path)
+{
+	git_repository *sub;
+	git_buf abspath = GIT_BUF_INIT;
+	git_repository *repo = INDEX_OWNER(index);
+	git_reference *head;
+	git_index_entry *entry;
+	struct stat st;
+	int error;
+
+	if ((error = git_buf_joinpath(&abspath, git_repository_workdir(repo), path)) < 0)
+		return error;
+
+	if ((error = p_stat(abspath.ptr, &st)) < 0) {
+		giterr_set(GITERR_OS, "failed to stat repository dir");
+		return -1;
+	}
+
+	if (index_entry_create(&entry, INDEX_OWNER(index), path, &st, true) < 0)
+		return -1;
+
+	git_index_entry__init_from_stat(entry, &st, !index->distrust_filemode);
+
+	if ((error = git_repository_open(&sub, abspath.ptr)) < 0)
+		return error;
+
+	if ((error = git_repository_head(&head, sub)) < 0)
+		return error;
+
+	git_oid_cpy(&entry->id, git_reference_target(head));
+	entry->mode = GIT_FILEMODE_COMMIT;
+
+	git_reference_free(head);
+	git_repository_free(sub);
+	git_buf_free(&abspath);
+
+	*out = entry;
+	return 0;
+}
+
+int git_index_add_bypath(git_index *index, const char *path)
+{
+	git_index_entry *entry = NULL;
+	int ret;
+
+	assert(index && path);
+
+	if ((ret = index_entry_init(&entry, index, path)) == 0)
+		ret = index_insert(index, &entry, 1, false, false, true);
+
+	/* If we were given a directory, let's see if it's a submodule */
+	if (ret < 0 && ret != GIT_EDIRECTORY)
+		return ret;
+
+	if (ret == GIT_EDIRECTORY) {
+		git_submodule *sm;
+		git_error_state err;
+
+		giterr_state_capture(&err, ret);
+
+		ret = git_submodule_lookup(&sm, INDEX_OWNER(index), path);
+		if (ret == GIT_ENOTFOUND)
+			return giterr_state_restore(&err);
+
+		giterr_state_free(&err);
+
+		/*
+		 * EEXISTS means that there is a repository at that path, but it's not known
+		 * as a submodule. We add its HEAD as an entry and don't register it.
+		 */
+		if (ret == GIT_EEXISTS) {
+			if ((ret = add_repo_as_submodule(&entry, index, path)) < 0)
+				return ret;
+
+			if ((ret = index_insert(index, &entry, 1, false, false, true)) < 0)
+				return ret;
+		} else if (ret < 0) {
+			return ret;
+		} else {
+			ret = git_submodule_add_to_index(sm, false);
+			git_submodule_free(sm);
+			return ret;
+		}
+	}
+
+	/* Adding implies conflict was resolved, move conflict entries to REUC */
+	if ((ret = index_conflict_to_reuc(index, path)) < 0 && ret != GIT_ENOTFOUND)
+		return ret;
+
+	git_tree_cache_invalidate_path(index->tree, entry->path);
+	return 0;
+}
+
+int git_index_remove_bypath(git_index *index, const char *path)
+{
+	int ret;
+
+	assert(index && path);
+
+	if (((ret = git_index_remove(index, path, 0)) < 0 &&
+		ret != GIT_ENOTFOUND) ||
+		((ret = index_conflict_to_reuc(index, path)) < 0 &&
+		ret != GIT_ENOTFOUND))
+		return ret;
+
+	if (ret == GIT_ENOTFOUND)
+		giterr_clear();
+
+	return 0;
+}
+
+int git_index__fill(git_index *index, const git_vector *source_entries)
+{
+	const git_index_entry *source_entry = NULL;
+	size_t i;
+	int ret = 0;
+
+	assert(index);
+
+	if (!source_entries->length)
+		return 0;
+
+	git_vector_size_hint(&index->entries, source_entries->length);
+	git_idxmap_resize(index->entries_map, (khint_t)(source_entries->length * 1.3));
+
+	git_vector_foreach(source_entries, i, source_entry) {
+		git_index_entry *entry = NULL;
+
+		if ((ret = index_entry_dup(&entry, index, source_entry)) < 0)
+			break;
+
+		index_entry_adjust_namemask(entry, ((struct entry_internal *)entry)->pathlen);
+		entry->flags_extended |= GIT_IDXENTRY_UPTODATE;
+		entry->mode = git_index__create_mode(entry->mode);
+
+		if ((ret = git_vector_insert(&index->entries, entry)) < 0)
+			break;
+
+		INSERT_IN_MAP(index, entry, &ret);
+		if (ret < 0)
+			break;
+	}
+
+	if (!ret)
+		git_vector_sort(&index->entries);
+
+	return ret;
+}
+
+
+int git_index_add(git_index *index, const git_index_entry *source_entry)
+{
+	git_index_entry *entry = NULL;
+	int ret;
+
+	assert(index && source_entry && source_entry->path);
+
+	if (!valid_filemode(source_entry->mode)) {
+		giterr_set(GITERR_INDEX, "invalid entry mode");
+		return -1;
+	}
+
+	if ((ret = index_entry_dup(&entry, index, source_entry)) < 0 ||
+		(ret = index_insert(index, &entry, 1, true, true, false)) < 0)
+		return ret;
+
+	git_tree_cache_invalidate_path(index->tree, entry->path);
+	return 0;
+}
+
+int git_index_remove(git_index *index, const char *path, int stage)
+{
+	int error;
+	size_t position;
+	git_index_entry remove_key = {{ 0 }};
+
+	remove_key.path = path;
+	GIT_IDXENTRY_STAGE_SET(&remove_key, stage);
+
+	DELETE_IN_MAP(index, &remove_key);
+
+	if (index_find(&position, index, path, 0, stage) < 0) {
+		giterr_set(
+			GITERR_INDEX, "index does not contain %s at stage %d", path, stage);
+		error = GIT_ENOTFOUND;
+	} else {
+		error = index_remove_entry(index, position);
+	}
+
+	return error;
+}
+
+int git_index_remove_directory(git_index *index, const char *dir, int stage)
+{
+	git_buf pfx = GIT_BUF_INIT;
+	int error = 0;
+	size_t pos;
+	git_index_entry *entry;
+
+	if (!(error = git_buf_sets(&pfx, dir)) &&
+		!(error = git_path_to_dir(&pfx)))
+		index_find(&pos, index, pfx.ptr, pfx.size, GIT_INDEX_STAGE_ANY);
+
+	while (!error) {
+		entry = git_vector_get(&index->entries, pos);
+		if (!entry || git__prefixcmp(entry->path, pfx.ptr) != 0)
+			break;
+
+		if (GIT_IDXENTRY_STAGE(entry) != stage) {
+			++pos;
+			continue;
+		}
+
+		error = index_remove_entry(index, pos);
+
+		/* removed entry at 'pos' so we don't need to increment */
+	}
+
+	git_buf_free(&pfx);
+
+	return error;
+}
+
+int git_index_find_prefix(size_t *at_pos, git_index *index, const char *prefix)
+{
+	int error = 0;
+	size_t pos;
+	const git_index_entry *entry;
+
+	index_find(&pos, index, prefix, strlen(prefix), GIT_INDEX_STAGE_ANY);
+	entry = git_vector_get(&index->entries, pos);
+	if (!entry || git__prefixcmp(entry->path, prefix) != 0)
+		error = GIT_ENOTFOUND;
+
+	if (!error && at_pos)
+		*at_pos = pos;
+
+	return error;
+}
+
+int git_index__find_pos(
+	size_t *out, git_index *index, const char *path, size_t path_len, int stage)
+{
+	assert(index && path);
+	return index_find(out, index, path, path_len, stage);
+}
+
+int git_index_find(size_t *at_pos, git_index *index, const char *path)
+{
+	size_t pos;
+
+	assert(index && path);
+
+	if (git_vector_bsearch2(
+			&pos, &index->entries, index->entries_search_path, path) < 0) {
+		giterr_set(GITERR_INDEX, "index does not contain %s", path);
+		return GIT_ENOTFOUND;
+	}
+
+	/* Since our binary search only looked at path, we may be in the
+	 * middle of a list of stages.
+	 */
+	for (; pos > 0; --pos) {
+		const git_index_entry *prev = git_vector_get(&index->entries, pos - 1);
+
+		if (index->entries_cmp_path(prev->path, path) != 0)
+			break;
+	}
+
+	if (at_pos)
+		*at_pos = pos;
+
+	return 0;
+}
+
+int git_index_conflict_add(git_index *index,
+	const git_index_entry *ancestor_entry,
+	const git_index_entry *our_entry,
+	const git_index_entry *their_entry)
+{
+	git_index_entry *entries[3] = { 0 };
+	unsigned short i;
+	int ret = 0;
+
+	assert (index);
+
+	if ((ancestor_entry &&
+			(ret = index_entry_dup(&entries[0], index, ancestor_entry)) < 0) ||
+		(our_entry &&
+			(ret = index_entry_dup(&entries[1], index, our_entry)) < 0) ||
+		(their_entry &&
+			(ret = index_entry_dup(&entries[2], index, their_entry)) < 0))
+		goto on_error;
+
+	/* Validate entries */
+	for (i = 0; i < 3; i++) {
+		if (entries[i] && !valid_filemode(entries[i]->mode)) {
+			giterr_set(GITERR_INDEX, "invalid filemode for stage %d entry",
+				i + 1);
+			return -1;
+		}
+	}
+
+	/* Remove existing index entries for each path */
+	for (i = 0; i < 3; i++) {
+		if (entries[i] == NULL)
+			continue;
+
+		if ((ret = git_index_remove(index, entries[i]->path, 0)) != 0) {
+			if (ret != GIT_ENOTFOUND)
+				goto on_error;
+
+			giterr_clear();
+			ret = 0;
+		}
+	}
+
+	/* Add the conflict entries */
+	for (i = 0; i < 3; i++) {
+		if (entries[i] == NULL)
+			continue;
+
+		/* Make sure stage is correct */
+		GIT_IDXENTRY_STAGE_SET(entries[i], i + 1);
+
+		if ((ret = index_insert(index, &entries[i], 1, true, true, false)) < 0)
+			goto on_error;
+
+		entries[i] = NULL; /* don't free if later entry fails */
+	}
+
+	return 0;
+
+on_error:
+	for (i = 0; i < 3; i++) {
+		if (entries[i] != NULL)
+			index_entry_free(entries[i]);
+	}
+
+	return ret;
+}
+
+static int index_conflict__get_byindex(
+	const git_index_entry **ancestor_out,
+	const git_index_entry **our_out,
+	const git_index_entry **their_out,
+	git_index *index,
+	size_t n)
+{
+	const git_index_entry *conflict_entry;
+	const char *path = NULL;
+	size_t count;
+	int stage, len = 0;
+
+	assert(ancestor_out && our_out && their_out && index);
+
+	*ancestor_out = NULL;
+	*our_out = NULL;
+	*their_out = NULL;
+
+	for (count = git_index_entrycount(index); n < count; ++n) {
+		conflict_entry = git_vector_get(&index->entries, n);
+
+		if (path && index->entries_cmp_path(conflict_entry->path, path) != 0)
+			break;
+
+		stage = GIT_IDXENTRY_STAGE(conflict_entry);
+		path = conflict_entry->path;
+
+		switch (stage) {
+		case 3:
+			*their_out = conflict_entry;
+			len++;
+			break;
+		case 2:
+			*our_out = conflict_entry;
+			len++;
+			break;
+		case 1:
+			*ancestor_out = conflict_entry;
+			len++;
+			break;
+		default:
+			break;
+		};
+	}
+
+	return len;
+}
+
+int git_index_conflict_get(
+	const git_index_entry **ancestor_out,
+	const git_index_entry **our_out,
+	const git_index_entry **their_out,
+	git_index *index,
+	const char *path)
+{
+	size_t pos;
+	int len = 0;
+
+	assert(ancestor_out && our_out && their_out && index && path);
+
+	*ancestor_out = NULL;
+	*our_out = NULL;
+	*their_out = NULL;
+
+	if (git_index_find(&pos, index, path) < 0)
+		return GIT_ENOTFOUND;
+
+	if ((len = index_conflict__get_byindex(
+		ancestor_out, our_out, their_out, index, pos)) < 0)
+		return len;
+	else if (len == 0)
+		return GIT_ENOTFOUND;
+
+	return 0;
+}
+
+static int index_conflict_remove(git_index *index, const char *path)
+{
+	size_t pos = 0;
+	git_index_entry *conflict_entry;
+	int error = 0;
+
+	if (path != NULL && git_index_find(&pos, index, path) < 0)
+		return GIT_ENOTFOUND;
+
+	while ((conflict_entry = git_vector_get(&index->entries, pos)) != NULL) {
+
+		if (path != NULL &&
+			index->entries_cmp_path(conflict_entry->path, path) != 0)
+			break;
+
+		if (GIT_IDXENTRY_STAGE(conflict_entry) == 0) {
+			pos++;
+			continue;
+		}
+
+		if ((error = index_remove_entry(index, pos)) < 0)
+			break;
+	}
+
+	return error;
+}
+
+int git_index_conflict_remove(git_index *index, const char *path)
+{
+	assert(index && path);
+	return index_conflict_remove(index, path);
+}
+
+int git_index_conflict_cleanup(git_index *index)
+{
+	assert(index);
+	return index_conflict_remove(index, NULL);
+}
+
+int git_index_has_conflicts(const git_index *index)
+{
+	size_t i;
+	git_index_entry *entry;
+
+	assert(index);
+
+	git_vector_foreach(&index->entries, i, entry) {
+		if (GIT_IDXENTRY_STAGE(entry) > 0)
+			return 1;
+	}
+
+	return 0;
+}
+
+int git_index_conflict_iterator_new(
+	git_index_conflict_iterator **iterator_out,
+	git_index *index)
+{
+	git_index_conflict_iterator *it = NULL;
+
+	assert(iterator_out && index);
+
+	it = git__calloc(1, sizeof(git_index_conflict_iterator));
+	GITERR_CHECK_ALLOC(it);
+
+	it->index = index;
+
+	*iterator_out = it;
+	return 0;
+}
+
+int git_index_conflict_next(
+	const git_index_entry **ancestor_out,
+	const git_index_entry **our_out,
+	const git_index_entry **their_out,
+	git_index_conflict_iterator *iterator)
+{
+	const git_index_entry *entry;
+	int len;
+
+	assert(ancestor_out && our_out && their_out && iterator);
+
+	*ancestor_out = NULL;
+	*our_out = NULL;
+	*their_out = NULL;
+
+	while (iterator->cur < iterator->index->entries.length) {
+		entry = git_index_get_byindex(iterator->index, iterator->cur);
+
+		if (git_index_entry_is_conflict(entry)) {
+			if ((len = index_conflict__get_byindex(
+				ancestor_out,
+				our_out,
+				their_out,
+				iterator->index,
+				iterator->cur)) < 0)
+				return len;
+
+			iterator->cur += len;
+			return 0;
+		}
+
+		iterator->cur++;
+	}
+
+	return GIT_ITEROVER;
+}
+
+void git_index_conflict_iterator_free(git_index_conflict_iterator *iterator)
+{
+	if (iterator == NULL)
+		return;
+
+	git__free(iterator);
+}
+
+size_t git_index_name_entrycount(git_index *index)
+{
+	assert(index);
+	return index->names.length;
+}
+
+const git_index_name_entry *git_index_name_get_byindex(
+	git_index *index, size_t n)
+{
+	assert(index);
+
+	git_vector_sort(&index->names);
+	return git_vector_get(&index->names, n);
+}
+
+static void index_name_entry_free(git_index_name_entry *ne)
+{
+	if (!ne)
+		return;
+	git__free(ne->ancestor);
+	git__free(ne->ours);
+	git__free(ne->theirs);
+	git__free(ne);
+}
+
+int git_index_name_add(git_index *index,
+	const char *ancestor, const char *ours, const char *theirs)
+{
+	git_index_name_entry *conflict_name;
+
+	assert((ancestor && ours) || (ancestor && theirs) || (ours && theirs));
+
+	conflict_name = git__calloc(1, sizeof(git_index_name_entry));
+	GITERR_CHECK_ALLOC(conflict_name);
+
+	if ((ancestor && !(conflict_name->ancestor = git__strdup(ancestor))) ||
+		(ours     && !(conflict_name->ours     = git__strdup(ours))) ||
+		(theirs   && !(conflict_name->theirs   = git__strdup(theirs))) ||
+		git_vector_insert(&index->names, conflict_name) < 0)
+	{
+		index_name_entry_free(conflict_name);
+		return -1;
+	}
+
+	return 0;
+}
+
+void git_index_name_clear(git_index *index)
+{
+	size_t i;
+	git_index_name_entry *conflict_name;
+
+	assert(index);
+
+	git_vector_foreach(&index->names, i, conflict_name)
+		index_name_entry_free(conflict_name);
+
+	git_vector_clear(&index->names);
+}
+
+size_t git_index_reuc_entrycount(git_index *index)
+{
+	assert(index);
+	return index->reuc.length;
+}
+
+static int index_reuc_on_dup(void **old, void *new)
+{
+	index_entry_reuc_free(*old);
+	*old = new;
+	return GIT_EEXISTS;
+}
+
+static int index_reuc_insert(
+	git_index *index,
+	git_index_reuc_entry *reuc)
+{
+	int res;
+
+	assert(index && reuc && reuc->path != NULL);
+	assert(git_vector_is_sorted(&index->reuc));
+
+	res = git_vector_insert_sorted(&index->reuc, reuc, &index_reuc_on_dup);
+	return res == GIT_EEXISTS ? 0 : res;
+}
+
+int git_index_reuc_add(git_index *index, const char *path,
+	int ancestor_mode, const git_oid *ancestor_oid,
+	int our_mode, const git_oid *our_oid,
+	int their_mode, const git_oid *their_oid)
+{
+	git_index_reuc_entry *reuc = NULL;
+	int error = 0;
+
+	assert(index && path);
+
+	if ((error = index_entry_reuc_init(&reuc, path, ancestor_mode,
+			ancestor_oid, our_mode, our_oid, their_mode, their_oid)) < 0 ||
+		(error = index_reuc_insert(index, reuc)) < 0)
+		index_entry_reuc_free(reuc);
+
+	return error;
+}
+
+int git_index_reuc_find(size_t *at_pos, git_index *index, const char *path)
+{
+	return git_vector_bsearch2(at_pos, &index->reuc, index->reuc_search, path);
+}
+
+const git_index_reuc_entry *git_index_reuc_get_bypath(
+	git_index *index, const char *path)
+{
+	size_t pos;
+	assert(index && path);
+
+	if (!index->reuc.length)
+		return NULL;
+
+	assert(git_vector_is_sorted(&index->reuc));
+
+	if (git_index_reuc_find(&pos, index, path) < 0)
+		return NULL;
+
+	return git_vector_get(&index->reuc, pos);
+}
+
+const git_index_reuc_entry *git_index_reuc_get_byindex(
+	git_index *index, size_t n)
+{
+	assert(index);
+	assert(git_vector_is_sorted(&index->reuc));
+
+	return git_vector_get(&index->reuc, n);
+}
+
+int git_index_reuc_remove(git_index *index, size_t position)
+{
+	int error;
+	git_index_reuc_entry *reuc;
+
+	assert(git_vector_is_sorted(&index->reuc));
+
+	reuc = git_vector_get(&index->reuc, position);
+	error = git_vector_remove(&index->reuc, position);
+
+	if (!error)
+		index_entry_reuc_free(reuc);
+
+	return error;
+}
+
+void git_index_reuc_clear(git_index *index)
+{
+	size_t i;
+
+	assert(index);
+
+	for (i = 0; i < index->reuc.length; ++i)
+		index_entry_reuc_free(git__swap(index->reuc.contents[i], NULL));
+
+	git_vector_clear(&index->reuc);
+}
+
+static int index_error_invalid(const char *message)
+{
+	giterr_set(GITERR_INDEX, "invalid data in index - %s", message);
+	return -1;
+}
+
+static int read_reuc(git_index *index, const char *buffer, size_t size)
+{
+	const char *endptr;
+	size_t len;
+	int i;
+
+	/* If called multiple times, the vector might already be initialized */
+	if (index->reuc._alloc_size == 0 &&
+		git_vector_init(&index->reuc, 16, reuc_cmp) < 0)
+		return -1;
+
+	while (size) {
+		git_index_reuc_entry *lost;
+
+		len = p_strnlen(buffer, size) + 1;
+		if (size <= len)
+			return index_error_invalid("reading reuc entries");
+
+		lost = reuc_entry_alloc(buffer);
+		GITERR_CHECK_ALLOC(lost);
+
+		size -= len;
+		buffer += len;
+
+		/* read 3 ASCII octal numbers for stage entries */
+		for (i = 0; i < 3; i++) {
+			int64_t tmp;
+
+			if (git__strtol64(&tmp, buffer, &endptr, 8) < 0 ||
+				!endptr || endptr == buffer || *endptr ||
+				tmp < 0 || tmp > UINT32_MAX) {
+				index_entry_reuc_free(lost);
+				return index_error_invalid("reading reuc entry stage");
+			}
+
+			lost->mode[i] = (uint32_t)tmp;
+
+			len = (endptr + 1) - buffer;
+			if (size <= len) {
+				index_entry_reuc_free(lost);
+				return index_error_invalid("reading reuc entry stage");
+			}
+
+			size -= len;
+			buffer += len;
+		}
+
+		/* read up to 3 OIDs for stage entries */
+		for (i = 0; i < 3; i++) {
+			if (!lost->mode[i])
+				continue;
+			if (size < 20) {
+				index_entry_reuc_free(lost);
+				return index_error_invalid("reading reuc entry oid");
+			}
+
+			git_oid_fromraw(&lost->oid[i], (const unsigned char *) buffer);
+			size -= 20;
+			buffer += 20;
+		}
+
+		/* entry was read successfully - insert into reuc vector */
+		if (git_vector_insert(&index->reuc, lost) < 0)
+			return -1;
+	}
+
+	/* entries are guaranteed to be sorted on-disk */
+	git_vector_set_sorted(&index->reuc, true);
+
+	return 0;
+}
+
+
+static int read_conflict_names(git_index *index, const char *buffer, size_t size)
+{
+	size_t len;
+
+	/* This gets called multiple times, the vector might already be initialized */
+	if (index->names._alloc_size == 0 &&
+		git_vector_init(&index->names, 16, conflict_name_cmp) < 0)
+		return -1;
+
+#define read_conflict_name(ptr) \
+	len = p_strnlen(buffer, size) + 1; \
+	if (size < len) { \
+		index_error_invalid("reading conflict name entries"); \
+		goto out_err; \
+	} \
+	if (len == 1) \
+		ptr = NULL; \
+	else { \
+		ptr = git__malloc(len); \
+		GITERR_CHECK_ALLOC(ptr); \
+		memcpy(ptr, buffer, len); \
+	} \
+	\
+	buffer += len; \
+	size -= len;
+
+	while (size) {
+		git_index_name_entry *conflict_name = git__calloc(1, sizeof(git_index_name_entry));
+		GITERR_CHECK_ALLOC(conflict_name);
+
+		read_conflict_name(conflict_name->ancestor);
+		read_conflict_name(conflict_name->ours);
+		read_conflict_name(conflict_name->theirs);
+
+		if (git_vector_insert(&index->names, conflict_name) < 0)
+			goto out_err;
+
+		continue;
+
+out_err:
+		git__free(conflict_name->ancestor);
+		git__free(conflict_name->ours);
+		git__free(conflict_name->theirs);
+		git__free(conflict_name);
+		return -1;
+	}
+
+#undef read_conflict_name
+
+	/* entries are guaranteed to be sorted on-disk */
+	git_vector_set_sorted(&index->names, true);
+
+	return 0;
+}
+
+static size_t index_entry_size(size_t path_len, size_t varint_len, uint32_t flags)
+{
+	if (varint_len) {
+		if (flags & GIT_IDXENTRY_EXTENDED)
+			return offsetof(struct entry_long, path) + path_len + 1 + varint_len;
+		else
+			return offsetof(struct entry_short, path) + path_len + 1 + varint_len;
+	} else {
+#define entry_size(type,len) ((offsetof(type, path) + (len) + 8) & ~7)
+		if (flags & GIT_IDXENTRY_EXTENDED)
+			return entry_size(struct entry_long, path_len);
+		else
+			return entry_size(struct entry_short, path_len);
+#undef entry_size
+	}
+}
+
+static int read_entry(
+	git_index_entry **out,
+	size_t *out_size,
+	git_index *index,
+	const void *buffer,
+	size_t buffer_size,
+	const char *last)
+{
+	size_t path_length, entry_size;
+	const char *path_ptr;
+	struct entry_short source;
+	git_index_entry entry = {{0}};
+	bool compressed = index->version >= INDEX_VERSION_NUMBER_COMP;
+	char *tmp_path = NULL;
+
+	if (INDEX_FOOTER_SIZE + minimal_entry_size > buffer_size)
+		return -1;
+
+	/* buffer is not guaranteed to be aligned */
+	memcpy(&source, buffer, sizeof(struct entry_short));
+
+	entry.ctime.seconds = (git_time_t)ntohl(source.ctime.seconds);
+	entry.ctime.nanoseconds = ntohl(source.ctime.nanoseconds);
+	entry.mtime.seconds = (git_time_t)ntohl(source.mtime.seconds);
+	entry.mtime.nanoseconds = ntohl(source.mtime.nanoseconds);
+	entry.dev = ntohl(source.dev);
+	entry.ino = ntohl(source.ino);
+	entry.mode = ntohl(source.mode);
+	entry.uid = ntohl(source.uid);
+	entry.gid = ntohl(source.gid);
+	entry.file_size = ntohl(source.file_size);
+	git_oid_cpy(&entry.id, &source.oid);
+	entry.flags = ntohs(source.flags);
+
+	if (entry.flags & GIT_IDXENTRY_EXTENDED) {
+		uint16_t flags_raw;
+		size_t flags_offset;
+
+		flags_offset = offsetof(struct entry_long, flags_extended);
+		memcpy(&flags_raw, (const char *) buffer + flags_offset,
+			sizeof(flags_raw));
+		flags_raw = ntohs(flags_raw);
+
+		memcpy(&entry.flags_extended, &flags_raw, sizeof(flags_raw));
+		path_ptr = (const char *) buffer + offsetof(struct entry_long, path);
+	} else
+		path_ptr = (const char *) buffer + offsetof(struct entry_short, path);
+
+	if (!compressed) {
+		path_length = entry.flags & GIT_IDXENTRY_NAMEMASK;
+
+		/* if this is a very long string, we must find its
+		 * real length without overflowing */
+		if (path_length == 0xFFF) {
+			const char *path_end;
+
+			path_end = memchr(path_ptr, '\0', buffer_size);
+			if (path_end == NULL)
+				return -1;
+
+			path_length = path_end - path_ptr;
+		}
+
+		entry_size = index_entry_size(path_length, 0, entry.flags);
+		entry.path = (char *)path_ptr;
+	} else {
+		size_t varint_len, last_len, prefix_len, suffix_len, path_len;
+		uintmax_t strip_len;
+
+		strip_len = git_decode_varint((const unsigned char *)path_ptr, &varint_len);
+		last_len = strlen(last);
+
+		if (varint_len == 0 || last_len < strip_len)
+			return index_error_invalid("incorrect prefix length");
+
+		prefix_len = last_len - strip_len;
+		suffix_len = strlen(path_ptr + varint_len);
+
+		GITERR_CHECK_ALLOC_ADD(&path_len, prefix_len, suffix_len);
+		GITERR_CHECK_ALLOC_ADD(&path_len, path_len, 1);
+
+		if (path_len > GIT_PATH_MAX)
+			return index_error_invalid("unreasonable path length");
+
+		tmp_path = git__malloc(path_len);
+		GITERR_CHECK_ALLOC(tmp_path);
+
+		memcpy(tmp_path, last, prefix_len);
+		memcpy(tmp_path + prefix_len, path_ptr + varint_len, suffix_len + 1);
+		entry_size = index_entry_size(suffix_len, varint_len, entry.flags);
+		entry.path = tmp_path;
+	}
+
+	if (entry_size == 0)
+		return -1;
+
+	if (INDEX_FOOTER_SIZE + entry_size > buffer_size)
+		return -1;
+
+	if (index_entry_dup(out, index, &entry) < 0) {
+		git__free(tmp_path);
+		return -1;
+	}
+
+	git__free(tmp_path);
+	*out_size = entry_size;
+	return 0;
+}
+
+static int read_header(struct index_header *dest, const void *buffer)
+{
+	const struct index_header *source = buffer;
+
+	dest->signature = ntohl(source->signature);
+	if (dest->signature != INDEX_HEADER_SIG)
+		return index_error_invalid("incorrect header signature");
+
+	dest->version = ntohl(source->version);
+	if (dest->version < INDEX_VERSION_NUMBER_LB ||
+		dest->version > INDEX_VERSION_NUMBER_UB)
+		return index_error_invalid("incorrect header version");
+
+	dest->entry_count = ntohl(source->entry_count);
+	return 0;
+}
+
+static size_t read_extension(git_index *index, const char *buffer, size_t buffer_size)
+{
+	struct index_extension dest;
+	size_t total_size;
+
+	/* buffer is not guaranteed to be aligned */
+	memcpy(&dest, buffer, sizeof(struct index_extension));
+	dest.extension_size = ntohl(dest.extension_size);
+
+	total_size = dest.extension_size + sizeof(struct index_extension);
+
+	if (dest.extension_size > total_size ||
+		buffer_size < total_size ||
+		buffer_size - total_size < INDEX_FOOTER_SIZE)
+		return 0;
+
+	/* optional extension */
+	if (dest.signature[0] >= 'A' && dest.signature[0] <= 'Z') {
+		/* tree cache */
+		if (memcmp(dest.signature, INDEX_EXT_TREECACHE_SIG, 4) == 0) {
+			if (git_tree_cache_read(&index->tree, buffer + 8, dest.extension_size, &index->tree_pool) < 0)
+				return 0;
+		} else if (memcmp(dest.signature, INDEX_EXT_UNMERGED_SIG, 4) == 0) {
+			if (read_reuc(index, buffer + 8, dest.extension_size) < 0)
+				return 0;
+		} else if (memcmp(dest.signature, INDEX_EXT_CONFLICT_NAME_SIG, 4) == 0) {
+			if (read_conflict_names(index, buffer + 8, dest.extension_size) < 0)
+				return 0;
+		}
+		/* else, unsupported extension. We cannot parse this, but we can skip
+		 * it by returning `total_size */
+	} else {
+		/* we cannot handle non-ignorable extensions;
+		 * in fact they aren't even defined in the standard */
+		return 0;
+	}
+
+	return total_size;
+}
+
+static int parse_index(git_index *index, const char *buffer, size_t buffer_size)
+{
+	int error = 0;
+	unsigned int i;
+	struct index_header header = { 0 };
+	git_oid checksum_calculated, checksum_expected;
+	const char *last = NULL;
+	const char *empty = "";
+
+#define seek_forward(_increase) { \
+	if (_increase >= buffer_size) { \
+		error = index_error_invalid("ran out of data while parsing"); \
+		goto done; } \
+	buffer += _increase; \
+	buffer_size -= _increase;\
+}
+
+	if (buffer_size < INDEX_HEADER_SIZE + INDEX_FOOTER_SIZE)
+		return index_error_invalid("insufficient buffer space");
+
+	/* Precalculate the SHA1 of the files's contents -- we'll match it to
+	 * the provided SHA1 in the footer */
+	git_hash_buf(&checksum_calculated, buffer, buffer_size - INDEX_FOOTER_SIZE);
+
+	/* Parse header */
+	if ((error = read_header(&header, buffer)) < 0)
+		return error;
+
+	index->version = header.version;
+	if (index->version >= INDEX_VERSION_NUMBER_COMP)
+		last = empty;
+
+	seek_forward(INDEX_HEADER_SIZE);
+
+	assert(!index->entries.length);
+
+	if (index->ignore_case)
+		git_idxmap_icase_resize((khash_t(idxicase) *) index->entries_map, header.entry_count);
+	else
+		git_idxmap_resize(index->entries_map, header.entry_count);
+
+	/* Parse all the entries */
+	for (i = 0; i < header.entry_count && buffer_size > INDEX_FOOTER_SIZE; ++i) {
+		git_index_entry *entry = NULL;
+		size_t entry_size;
+
+		if ((error = read_entry(&entry, &entry_size, index, buffer, buffer_size, last)) < 0) {
+			error = index_error_invalid("invalid entry");
+			goto done;
+		}
+
+		if ((error = git_vector_insert(&index->entries, entry)) < 0) {
+			index_entry_free(entry);
+			goto done;
+		}
+
+		INSERT_IN_MAP(index, entry, &error);
+
+		if (error < 0) {
+			index_entry_free(entry);
+			goto done;
+		}
+		error = 0;
+
+		if (index->version >= INDEX_VERSION_NUMBER_COMP)
+			last = entry->path;
+
+		seek_forward(entry_size);
+	}
+
+	if (i != header.entry_count) {
+		error = index_error_invalid("header entries changed while parsing");
+		goto done;
+	}
+
+	/* There's still space for some extensions! */
+	while (buffer_size > INDEX_FOOTER_SIZE) {
+		size_t extension_size;
+
+		extension_size = read_extension(index, buffer, buffer_size);
+
+		/* see if we have read any bytes from the extension */
+		if (extension_size == 0) {
+			error = index_error_invalid("extension is truncated");
+			goto done;
+		}
+
+		seek_forward(extension_size);
+	}
+
+	if (buffer_size != INDEX_FOOTER_SIZE) {
+		error = index_error_invalid(
+			"buffer size does not match index footer size");
+		goto done;
+	}
+
+	/* 160-bit SHA-1 over the content of the index file before this checksum. */
+	git_oid_fromraw(&checksum_expected, (const unsigned char *)buffer);
+
+	if (git_oid__cmp(&checksum_calculated, &checksum_expected) != 0) {
+		error = index_error_invalid(
+			"calculated checksum does not match expected");
+		goto done;
+	}
+
+	git_oid_cpy(&index->checksum, &checksum_calculated);
+
+#undef seek_forward
+
+	/* Entries are stored case-sensitively on disk, so re-sort now if
+	 * in-memory index is supposed to be case-insensitive
+	 */
+	git_vector_set_sorted(&index->entries, !index->ignore_case);
+	git_vector_sort(&index->entries);
+
+done:
+	return error;
+}
+
+static bool is_index_extended(git_index *index)
+{
+	size_t i, extended;
+	git_index_entry *entry;
+
+	extended = 0;
+
+	git_vector_foreach(&index->entries, i, entry) {
+		entry->flags &= ~GIT_IDXENTRY_EXTENDED;
+		if (entry->flags_extended & GIT_IDXENTRY_EXTENDED_FLAGS) {
+			extended++;
+			entry->flags |= GIT_IDXENTRY_EXTENDED;
+		}
+	}
+
+	return (extended > 0);
+}
+
+static int write_disk_entry(git_filebuf *file, git_index_entry *entry, const char *last)
+{
+	void *mem = NULL;
+	struct entry_short *ondisk;
+	size_t path_len, disk_size;
+	int varint_len = 0;
+	char *path;
+	const char *path_start = entry->path;
+	size_t same_len = 0;
+
+	path_len = ((struct entry_internal *)entry)->pathlen;
+
+	if (last) {
+		const char *last_c = last;
+
+		while (*path_start == *last_c) {
+			if (!*path_start || !*last_c)
+				break;
+			++path_start;
+			++last_c;
+			++same_len;
+		}
+		path_len -= same_len;
+		varint_len = git_encode_varint(NULL, 0, same_len);
+	}
+
+	disk_size = index_entry_size(path_len, varint_len, entry->flags);
+
+	if (git_filebuf_reserve(file, &mem, disk_size) < 0)
+		return -1;
+
+	ondisk = (struct entry_short *)mem;
+
+	memset(ondisk, 0x0, disk_size);
+
+	/**
+	 * Yes, we have to truncate.
+	 *
+	 * The on-disk format for Index entries clearly defines
+	 * the time and size fields to be 4 bytes each -- so even if
+	 * we store these values with 8 bytes on-memory, they must
+	 * be truncated to 4 bytes before writing to disk.
+	 *
+	 * In 2038 I will be either too dead or too rich to care about this
+	 */
+	ondisk->ctime.seconds = htonl((uint32_t)entry->ctime.seconds);
+	ondisk->mtime.seconds = htonl((uint32_t)entry->mtime.seconds);
+	ondisk->ctime.nanoseconds = htonl(entry->ctime.nanoseconds);
+	ondisk->mtime.nanoseconds = htonl(entry->mtime.nanoseconds);
+	ondisk->dev = htonl(entry->dev);
+	ondisk->ino = htonl(entry->ino);
+	ondisk->mode = htonl(entry->mode);
+	ondisk->uid = htonl(entry->uid);
+	ondisk->gid = htonl(entry->gid);
+	ondisk->file_size = htonl((uint32_t)entry->file_size);
+
+	git_oid_cpy(&ondisk->oid, &entry->id);
+
+	ondisk->flags = htons(entry->flags);
+
+	if (entry->flags & GIT_IDXENTRY_EXTENDED) {
+		struct entry_long *ondisk_ext;
+		ondisk_ext = (struct entry_long *)ondisk;
+		ondisk_ext->flags_extended = htons(entry->flags_extended &
+			GIT_IDXENTRY_EXTENDED_FLAGS);
+		path = ondisk_ext->path;
+		disk_size -= offsetof(struct entry_long, path);
+	} else {
+		path = ondisk->path;
+		disk_size -= offsetof(struct entry_short, path);
+	}
+
+	if (last) {
+		varint_len = git_encode_varint((unsigned char *) path,
+					  disk_size, same_len);
+		assert(varint_len > 0);
+		path += varint_len;
+		disk_size -= varint_len;
+
+		/*
+		 * If using path compression, we are not allowed
+		 * to have additional trailing NULs.
+		 */
+		assert(disk_size == path_len + 1);
+	} else {
+		/*
+		 * If no path compression is used, we do have
+		 * NULs as padding. As such, simply assert that
+		 * we have enough space left to write the path.
+		 */
+		assert(disk_size > path_len);
+	}
+
+	memcpy(path, path_start, path_len + 1);
+
+	return 0;
+}
+
+static int write_entries(git_index *index, git_filebuf *file)
+{
+	int error = 0;
+	size_t i;
+	git_vector case_sorted, *entries;
+	git_index_entry *entry;
+	const char *last = NULL;
+
+	/* If index->entries is sorted case-insensitively, then we need
+	 * to re-sort it case-sensitively before writing */
+	if (index->ignore_case) {
+		git_vector_dup(&case_sorted, &index->entries, git_index_entry_cmp);
+		git_vector_sort(&case_sorted);
+		entries = &case_sorted;
+	} else {
+		entries = &index->entries;
+	}
+
+	if (index->version >= INDEX_VERSION_NUMBER_COMP)
+		last = "";
+
+	git_vector_foreach(entries, i, entry) {
+		if ((error = write_disk_entry(file, entry, last)) < 0)
+			break;
+		if (index->version >= INDEX_VERSION_NUMBER_COMP)
+			last = entry->path;
+	}
+
+	if (index->ignore_case)
+		git_vector_free(&case_sorted);
+
+	return error;
+}
+
+static int write_extension(git_filebuf *file, struct index_extension *header, git_buf *data)
+{
+	struct index_extension ondisk;
+
+	memset(&ondisk, 0x0, sizeof(struct index_extension));
+	memcpy(&ondisk, header, 4);
+	ondisk.extension_size = htonl(header->extension_size);
+
+	git_filebuf_write(file, &ondisk, sizeof(struct index_extension));
+	return git_filebuf_write(file, data->ptr, data->size);
+}
+
+static int create_name_extension_data(git_buf *name_buf, git_index_name_entry *conflict_name)
+{
+	int error = 0;
+
+	if (conflict_name->ancestor == NULL)
+		error = git_buf_put(name_buf, "\0", 1);
+	else
+		error = git_buf_put(name_buf, conflict_name->ancestor, strlen(conflict_name->ancestor) + 1);
+
+	if (error != 0)
+		goto on_error;
+
+	if (conflict_name->ours == NULL)
+		error = git_buf_put(name_buf, "\0", 1);
+	else
+		error = git_buf_put(name_buf, conflict_name->ours, strlen(conflict_name->ours) + 1);
+
+	if (error != 0)
+		goto on_error;
+
+	if (conflict_name->theirs == NULL)
+		error = git_buf_put(name_buf, "\0", 1);
+	else
+		error = git_buf_put(name_buf, conflict_name->theirs, strlen(conflict_name->theirs) + 1);
+
+on_error:
+	return error;
+}
+
+static int write_name_extension(git_index *index, git_filebuf *file)
+{
+	git_buf name_buf = GIT_BUF_INIT;
+	git_vector *out = &index->names;
+	git_index_name_entry *conflict_name;
+	struct index_extension extension;
+	size_t i;
+	int error = 0;
+
+	git_vector_foreach(out, i, conflict_name) {
+		if ((error = create_name_extension_data(&name_buf, conflict_name)) < 0)
+			goto done;
+	}
+
+	memset(&extension, 0x0, sizeof(struct index_extension));
+	memcpy(&extension.signature, INDEX_EXT_CONFLICT_NAME_SIG, 4);
+	extension.extension_size = (uint32_t)name_buf.size;
+
+	error = write_extension(file, &extension, &name_buf);
+
+	git_buf_free(&name_buf);
+
+done:
+	return error;
+}
+
+static int create_reuc_extension_data(git_buf *reuc_buf, git_index_reuc_entry *reuc)
+{
+	int i;
+	int error = 0;
+
+	if ((error = git_buf_put(reuc_buf, reuc->path, strlen(reuc->path) + 1)) < 0)
+		return error;
+
+	for (i = 0; i < 3; i++) {
+		if ((error = git_buf_printf(reuc_buf, "%o", reuc->mode[i])) < 0 ||
+			(error = git_buf_put(reuc_buf, "\0", 1)) < 0)
+			return error;
+	}
+
+	for (i = 0; i < 3; i++) {
+		if (reuc->mode[i] && (error = git_buf_put(reuc_buf, (char *)&reuc->oid[i].id, GIT_OID_RAWSZ)) < 0)
+			return error;
+	}
+
+	return 0;
+}
+
+static int write_reuc_extension(git_index *index, git_filebuf *file)
+{
+	git_buf reuc_buf = GIT_BUF_INIT;
+	git_vector *out = &index->reuc;
+	git_index_reuc_entry *reuc;
+	struct index_extension extension;
+	size_t i;
+	int error = 0;
+
+	git_vector_foreach(out, i, reuc) {
+		if ((error = create_reuc_extension_data(&reuc_buf, reuc)) < 0)
+			goto done;
+	}
+
+	memset(&extension, 0x0, sizeof(struct index_extension));
+	memcpy(&extension.signature, INDEX_EXT_UNMERGED_SIG, 4);
+	extension.extension_size = (uint32_t)reuc_buf.size;
+
+	error = write_extension(file, &extension, &reuc_buf);
+
+	git_buf_free(&reuc_buf);
+
+done:
+	return error;
+}
+
+static int write_tree_extension(git_index *index, git_filebuf *file)
+{
+	struct index_extension extension;
+	git_buf buf = GIT_BUF_INIT;
+	int error;
+
+	if (index->tree == NULL)
+		return 0;
+
+	if ((error = git_tree_cache_write(&buf, index->tree)) < 0)
+		return error;
+
+	memset(&extension, 0x0, sizeof(struct index_extension));
+	memcpy(&extension.signature, INDEX_EXT_TREECACHE_SIG, 4);
+	extension.extension_size = (uint32_t)buf.size;
+
+	error = write_extension(file, &extension, &buf);
+
+	git_buf_free(&buf);
+
+	return error;
+}
+
+static void clear_uptodate(git_index *index)
+{
+	git_index_entry *entry;
+	size_t i;
+
+	git_vector_foreach(&index->entries, i, entry)
+		entry->flags_extended &= ~GIT_IDXENTRY_UPTODATE;
+}
+
+static int write_index(git_oid *checksum, git_index *index, git_filebuf *file)
+{
+	git_oid hash_final;
+	struct index_header header;
+	bool is_extended;
+	uint32_t index_version_number;
+
+	assert(index && file);
+
+	if (index->version <= INDEX_VERSION_NUMBER_EXT)  {
+		is_extended = is_index_extended(index);
+		index_version_number = is_extended ? INDEX_VERSION_NUMBER_EXT : INDEX_VERSION_NUMBER_LB;
+	} else {
+		index_version_number = index->version;
+	}
+
+	header.signature = htonl(INDEX_HEADER_SIG);
+	header.version = htonl(index_version_number);
+	header.entry_count = htonl((uint32_t)index->entries.length);
+
+	if (git_filebuf_write(file, &header, sizeof(struct index_header)) < 0)
+		return -1;
+
+	if (write_entries(index, file) < 0)
+		return -1;
+
+	/* write the tree cache extension */
+	if (index->tree != NULL && write_tree_extension(index, file) < 0)
+		return -1;
+
+	/* write the rename conflict extension */
+	if (index->names.length > 0 && write_name_extension(index, file) < 0)
+		return -1;
+
+	/* write the reuc extension */
+	if (index->reuc.length > 0 && write_reuc_extension(index, file) < 0)
+		return -1;
+
+	/* get out the hash for all the contents we've appended to the file */
+	git_filebuf_hash(&hash_final, file);
+	git_oid_cpy(checksum, &hash_final);
+
+	/* write it at the end of the file */
+	if (git_filebuf_write(file, hash_final.id, GIT_OID_RAWSZ) < 0)
+		return -1;
+
+	/* file entries are no longer up to date */
+	clear_uptodate(index);
+
+	return 0;
+}
+
+int git_index_entry_stage(const git_index_entry *entry)
+{
+	return GIT_IDXENTRY_STAGE(entry);
+}
+
+int git_index_entry_is_conflict(const git_index_entry *entry)
+{
+	return (GIT_IDXENTRY_STAGE(entry) > 0);
+}
+
+typedef struct read_tree_data {
+	git_index *index;
+	git_vector *old_entries;
+	git_vector *new_entries;
+	git_vector_cmp entry_cmp;
+	git_tree_cache *tree;
+} read_tree_data;
+
+static int read_tree_cb(
+	const char *root, const git_tree_entry *tentry, void *payload)
+{
+	read_tree_data *data = payload;
+	git_index_entry *entry = NULL, *old_entry;
+	git_buf path = GIT_BUF_INIT;
+	size_t pos;
+
+	if (git_tree_entry__is_tree(tentry))
+		return 0;
+
+	if (git_buf_joinpath(&path, root, tentry->filename) < 0)
+		return -1;
+
+	if (index_entry_create(&entry, INDEX_OWNER(data->index), path.ptr, NULL, false) < 0)
+		return -1;
+
+	entry->mode = tentry->attr;
+	git_oid_cpy(&entry->id, git_tree_entry_id(tentry));
+
+	/* look for corresponding old entry and copy data to new entry */
+	if (data->old_entries != NULL &&
+		!index_find_in_entries(
+			&pos, data->old_entries, data->entry_cmp, path.ptr, 0, 0) &&
+		(old_entry = git_vector_get(data->old_entries, pos)) != NULL &&
+		entry->mode == old_entry->mode &&
+		git_oid_equal(&entry->id, &old_entry->id))
+	{
+		index_entry_cpy(entry, old_entry);
+		entry->flags_extended = 0;
+	}
+
+	index_entry_adjust_namemask(entry, path.size);
+	git_buf_free(&path);
+
+	if (git_vector_insert(data->new_entries, entry) < 0) {
+		index_entry_free(entry);
+		return -1;
+	}
+
+	return 0;
+}
+
+int git_index_read_tree(git_index *index, const git_tree *tree)
+{
+	int error = 0;
+	git_vector entries = GIT_VECTOR_INIT;
+	git_idxmap *entries_map;
+	read_tree_data data;
+	size_t i;
+	git_index_entry *e;
+
+	if (git_idxmap_alloc(&entries_map) < 0)
+		return -1;
+
+	git_vector_set_cmp(&entries, index->entries._cmp); /* match sort */
+
+	data.index = index;
+	data.old_entries = &index->entries;
+	data.new_entries = &entries;
+	data.entry_cmp   = index->entries_search;
+
+	index->tree = NULL;
+	git_pool_clear(&index->tree_pool);
+
+	git_vector_sort(&index->entries);
+
+	if ((error = git_tree_walk(tree, GIT_TREEWALK_POST, read_tree_cb, &data)) < 0)
+		goto cleanup;
+
+	if (index->ignore_case)
+		git_idxmap_icase_resize((khash_t(idxicase) *) entries_map, entries.length);
+	else
+		git_idxmap_resize(entries_map, entries.length);
+
+	git_vector_foreach(&entries, i, e) {
+		INSERT_IN_MAP_EX(index, entries_map, e, &error);
+
+		if (error < 0) {
+			giterr_set(GITERR_INDEX, "failed to insert entry into map");
+			return error;
+		}
+	}
+
+	error = 0;
+
+	git_vector_sort(&entries);
+
+	if ((error = git_index_clear(index)) < 0) {
+		/* well, this isn't good */;
+	} else {
+		git_vector_swap(&entries, &index->entries);
+		entries_map = git__swap(index->entries_map, entries_map);
+	}
+
+cleanup:
+	git_vector_free(&entries);
+	git_idxmap_free(entries_map);
+	if (error < 0)
+		return error;
+
+	error = git_tree_cache_read_tree(&index->tree, tree, &index->tree_pool);
+
+	return error;
+}
+
+static int git_index_read_iterator(
+	git_index *index,
+	git_iterator *new_iterator,
+	size_t new_length_hint)
+{
+	git_vector new_entries = GIT_VECTOR_INIT,
+		remove_entries = GIT_VECTOR_INIT;
+	git_idxmap *new_entries_map = NULL;
+	git_iterator *index_iterator = NULL;
+	git_iterator_options opts = GIT_ITERATOR_OPTIONS_INIT;
+	const git_index_entry *old_entry, *new_entry;
+	git_index_entry *entry;
+	size_t i;
+	int error;
+
+	assert((new_iterator->flags & GIT_ITERATOR_DONT_IGNORE_CASE));
+
+	if ((error = git_vector_init(&new_entries, new_length_hint, index->entries._cmp)) < 0 ||
+		(error = git_vector_init(&remove_entries, index->entries.length, NULL)) < 0 ||
+		(error = git_idxmap_alloc(&new_entries_map)) < 0)
+		goto done;
+
+	if (index->ignore_case && new_length_hint)
+		git_idxmap_icase_resize((khash_t(idxicase) *) new_entries_map, new_length_hint);
+	else if (new_length_hint)
+		git_idxmap_resize(new_entries_map, new_length_hint);
+
+	opts.flags = GIT_ITERATOR_DONT_IGNORE_CASE |
+		GIT_ITERATOR_INCLUDE_CONFLICTS;
+
+	if ((error = git_iterator_for_index(&index_iterator,
+			git_index_owner(index), index, &opts)) < 0 ||
+		((error = git_iterator_current(&old_entry, index_iterator)) < 0 &&
+			error != GIT_ITEROVER) ||
+		((error = git_iterator_current(&new_entry, new_iterator)) < 0 &&
+			error != GIT_ITEROVER))
+		goto done;
+
+	while (true) {
+		git_index_entry
+			*dup_entry = NULL,
+			*add_entry = NULL,
+			*remove_entry = NULL;
+		int diff;
+
+		error = 0;
+
+		if (old_entry && new_entry)
+			diff = git_index_entry_cmp(old_entry, new_entry);
+		else if (!old_entry && new_entry)
+			diff = 1;
+		else if (old_entry && !new_entry)
+			diff = -1;
+		else
+			break;
+
+		if (diff < 0) {
+			remove_entry = (git_index_entry *)old_entry;
+		} else if (diff > 0) {
+			dup_entry = (git_index_entry *)new_entry;
+		} else {
+			/* Path and stage are equal, if the OID is equal, keep it to
+			 * keep the stat cache data.
+			 */
+			if (git_oid_equal(&old_entry->id, &new_entry->id) &&
+				old_entry->mode == new_entry->mode) {
+				add_entry = (git_index_entry *)old_entry;
+			} else {
+				dup_entry = (git_index_entry *)new_entry;
+				remove_entry = (git_index_entry *)old_entry;
+			}
+		}
+
+		if (dup_entry) {
+			if ((error = index_entry_dup_nocache(&add_entry, index, dup_entry)) < 0)
+				goto done;
+
+			index_entry_adjust_namemask(add_entry,
+				((struct entry_internal *)add_entry)->pathlen);
+		}
+
+		/* invalidate this path in the tree cache if this is new (to
+		 * invalidate the parent trees)
+		 */
+		if (dup_entry && !remove_entry && index->tree)
+			git_tree_cache_invalidate_path(index->tree, dup_entry->path);
+
+		if (add_entry) {
+			if ((error = git_vector_insert(&new_entries, add_entry)) == 0)
+				INSERT_IN_MAP_EX(index, new_entries_map, add_entry, &error);
+		}
+
+		if (remove_entry && error >= 0)
+			error = git_vector_insert(&remove_entries, remove_entry);
+
+		if (error < 0) {
+			giterr_set(GITERR_INDEX, "failed to insert entry");
+			goto done;
+		}
+
+		if (diff <= 0) {
+			if ((error = git_iterator_advance(&old_entry, index_iterator)) < 0 &&
+				error != GIT_ITEROVER)
+				goto done;
+		}
+
+		if (diff >= 0) {
+			if ((error = git_iterator_advance(&new_entry, new_iterator)) < 0 &&
+				error != GIT_ITEROVER)
+				goto done;
+		}
+	}
+
+	git_index_name_clear(index);
+	git_index_reuc_clear(index);
+
+	git_vector_swap(&new_entries, &index->entries);
+	new_entries_map = git__swap(index->entries_map, new_entries_map);
+
+	git_vector_foreach(&remove_entries, i, entry) {
+		if (index->tree)
+			git_tree_cache_invalidate_path(index->tree, entry->path);
+
+		index_entry_free(entry);
+	}
+
+	clear_uptodate(index);
+
+	error = 0;
+
+done:
+	git_idxmap_free(new_entries_map);
+	git_vector_free(&new_entries);
+	git_vector_free(&remove_entries);
+	git_iterator_free(index_iterator);
+	return error;
+}
+
+int git_index_read_index(
+	git_index *index,
+	const git_index *new_index)
+{
+	git_iterator *new_iterator = NULL;
+	git_iterator_options opts = GIT_ITERATOR_OPTIONS_INIT;
+	int error;
+
+	opts.flags = GIT_ITERATOR_DONT_IGNORE_CASE |
+		GIT_ITERATOR_INCLUDE_CONFLICTS;
+
+	if ((error = git_iterator_for_index(&new_iterator,
+		git_index_owner(new_index), (git_index *)new_index, &opts)) < 0 ||
+		(error = git_index_read_iterator(index, new_iterator,
+		new_index->entries.length)) < 0)
+		goto done;
+
+done:
+	git_iterator_free(new_iterator);
+	return error;
+}
+
+git_repository *git_index_owner(const git_index *index)
+{
+	return INDEX_OWNER(index);
+}
+
+enum {
+	INDEX_ACTION_NONE = 0,
+	INDEX_ACTION_UPDATE = 1,
+	INDEX_ACTION_REMOVE = 2,
+	INDEX_ACTION_ADDALL = 3,
+};
+
+int git_index_add_all(
+	git_index *index,
+	const git_strarray *paths,
+	unsigned int flags,
+	git_index_matched_path_cb cb,
+	void *payload)
+{
+	int error;
+	git_repository *repo;
+	git_iterator *wditer = NULL;
+	git_pathspec ps;
+	bool no_fnmatch = (flags & GIT_INDEX_ADD_DISABLE_PATHSPEC_MATCH) != 0;
+
+	assert(index);
+
+	repo = INDEX_OWNER(index);
+	if ((error = git_repository__ensure_not_bare(repo, "index add all")) < 0)
+		return error;
+
+	if ((error = git_pathspec__init(&ps, paths)) < 0)
+		return error;
+
+	/* optionally check that pathspec doesn't mention any ignored files */
+	if ((flags & GIT_INDEX_ADD_CHECK_PATHSPEC) != 0 &&
+		(flags & GIT_INDEX_ADD_FORCE) == 0 &&
+		(error = git_ignore__check_pathspec_for_exact_ignores(
+			repo, &ps.pathspec, no_fnmatch)) < 0)
+		goto cleanup;
+
+	error = index_apply_to_wd_diff(index, INDEX_ACTION_ADDALL, paths, flags, cb, payload);
+
+	if (error)
+		giterr_set_after_callback(error);
+
+cleanup:
+	git_iterator_free(wditer);
+	git_pathspec__clear(&ps);
+
+	return error;
+}
+
+struct foreach_diff_data {
+	git_index *index;
+	const git_pathspec *pathspec;
+	unsigned int flags;
+	git_index_matched_path_cb cb;
+	void *payload;
+};
+
+static int apply_each_file(const git_diff_delta *delta, float progress, void *payload)
+{
+	struct foreach_diff_data *data = payload;
+	const char *match, *path;
+	int error = 0;
+
+	GIT_UNUSED(progress);
+
+	path = delta->old_file.path;
+
+	/* We only want those which match the pathspecs */
+	if (!git_pathspec__match(
+		    &data->pathspec->pathspec, path, false, (bool)data->index->ignore_case,
+		    &match, NULL))
+		return 0;
+
+	if (data->cb)
+		error = data->cb(path, match, data->payload);
+
+	if (error > 0) /* skip this entry */
+		return 0;
+	if (error < 0) /* actual error */
+		return error;
+
+	/* If the workdir item does not exist, remove it from the index. */
+	if ((delta->new_file.flags & GIT_DIFF_FLAG_EXISTS) == 0)
+		error = git_index_remove_bypath(data->index, path);
+	else
+		error = git_index_add_bypath(data->index, delta->new_file.path);
+
+	return error;
+}
+
+static int index_apply_to_wd_diff(git_index *index, int action, const git_strarray *paths,
+				  unsigned int flags,
+				  git_index_matched_path_cb cb, void *payload)
+{
+	int error;
+	git_diff *diff;
+	git_pathspec ps;
+	git_repository *repo;
+	git_diff_options opts = GIT_DIFF_OPTIONS_INIT;
+	struct foreach_diff_data data = {
+		index,
+		NULL,
+		flags,
+		cb,
+		payload,
+	};
+
+	assert(index);
+	assert(action == INDEX_ACTION_UPDATE || action == INDEX_ACTION_ADDALL);
+
+	repo = INDEX_OWNER(index);
+
+	if (!repo) {
+		return create_index_error(-1,
+			"cannot run update; the index is not backed up by a repository.");
+	}
+
+	/*
+	 * We do the matching ourselves intead of passing the list to
+	 * diff because we want to tell the callback which one
+	 * matched, which we do not know if we ask diff to filter for us.
+	 */
+	if ((error = git_pathspec__init(&ps, paths)) < 0)
+		return error;
+
+	opts.flags = GIT_DIFF_INCLUDE_TYPECHANGE;
+	if (action == INDEX_ACTION_ADDALL) {
+		opts.flags |= GIT_DIFF_INCLUDE_UNTRACKED |
+			GIT_DIFF_RECURSE_UNTRACKED_DIRS;
+
+		if (flags == GIT_INDEX_ADD_FORCE)
+			opts.flags |= GIT_DIFF_INCLUDE_IGNORED;
+	}
+
+	if ((error = git_diff_index_to_workdir(&diff, repo, index, &opts)) < 0)
+		goto cleanup;
+
+	data.pathspec = &ps;
+	error = git_diff_foreach(diff, apply_each_file, NULL, NULL, NULL, &data);
+	git_diff_free(diff);
+
+	if (error) /* make sure error is set if callback stopped iteration */
+		giterr_set_after_callback(error);
+
+cleanup:
+	git_pathspec__clear(&ps);
+	return error;
+}
+
+static int index_apply_to_all(
+	git_index *index,
+	int action,
+	const git_strarray *paths,
+	git_index_matched_path_cb cb,
+	void *payload)
+{
+	int error = 0;
+	size_t i;
+	git_pathspec ps;
+	const char *match;
+	git_buf path = GIT_BUF_INIT;
+
+	assert(index);
+
+	if ((error = git_pathspec__init(&ps, paths)) < 0)
+		return error;
+
+	git_vector_sort(&index->entries);
+
+	for (i = 0; !error && i < index->entries.length; ++i) {
+		git_index_entry *entry = git_vector_get(&index->entries, i);
+
+		/* check if path actually matches */
+		if (!git_pathspec__match(
+				&ps.pathspec, entry->path, false, (bool)index->ignore_case,
+				&match, NULL))
+			continue;
+
+		/* issue notification callback if requested */
+		if (cb && (error = cb(entry->path, match, payload)) != 0) {
+			if (error > 0) { /* return > 0 means skip this one */
+				error = 0;
+				continue;
+			}
+			if (error < 0)   /* return < 0 means abort */
+				break;
+		}
+
+		/* index manipulation may alter entry, so don't depend on it */
+		if ((error = git_buf_sets(&path, entry->path)) < 0)
+			break;
+
+		switch (action) {
+		case INDEX_ACTION_NONE:
+			break;
+		case INDEX_ACTION_UPDATE:
+			error = git_index_add_bypath(index, path.ptr);
+
+			if (error == GIT_ENOTFOUND) {
+				giterr_clear();
+
+				error = git_index_remove_bypath(index, path.ptr);
+
+				if (!error) /* back up foreach if we removed this */
+					i--;
+			}
+			break;
+		case INDEX_ACTION_REMOVE:
+			if (!(error = git_index_remove_bypath(index, path.ptr)))
+				i--; /* back up foreach if we removed this */
+			break;
+		default:
+			giterr_set(GITERR_INVALID, "unknown index action %d", action);
+			error = -1;
+			break;
+		}
+	}
+
+	git_buf_free(&path);
+	git_pathspec__clear(&ps);
+
+	return error;
+}
+
+int git_index_remove_all(
+	git_index *index,
+	const git_strarray *pathspec,
+	git_index_matched_path_cb cb,
+	void *payload)
+{
+	int error = index_apply_to_all(
+		index, INDEX_ACTION_REMOVE, pathspec, cb, payload);
+
+	if (error) /* make sure error is set if callback stopped iteration */
+		giterr_set_after_callback(error);
+
+	return error;
+}
+
+int git_index_update_all(
+	git_index *index,
+	const git_strarray *pathspec,
+	git_index_matched_path_cb cb,
+	void *payload)
+{
+	int error = index_apply_to_wd_diff(index, INDEX_ACTION_UPDATE, pathspec, 0, cb, payload);
+	if (error) /* make sure error is set if callback stopped iteration */
+		giterr_set_after_callback(error);
+
+	return error;
+}
+
+int git_index_snapshot_new(git_vector *snap, git_index *index)
+{
+	int error;
+
+	GIT_REFCOUNT_INC(index);
+
+	git_atomic_inc(&index->readers);
+	git_vector_sort(&index->entries);
+
+	error = git_vector_dup(snap, &index->entries, index->entries._cmp);
+
+	if (error < 0)
+		git_index_free(index);
+
+	return error;
+}
+
+void git_index_snapshot_release(git_vector *snap, git_index *index)
+{
+	git_vector_free(snap);
+
+	git_atomic_dec(&index->readers);
+
+	git_index_free(index);
+}
+
+int git_index_snapshot_find(
+	size_t *out, git_vector *entries, git_vector_cmp entry_srch,
+	const char *path, size_t path_len, int stage)
+{
+	return index_find_in_entries(out, entries, entry_srch, path, path_len, stage);
+}
+
+int git_indexwriter_init(
+	git_indexwriter *writer,
+	git_index *index)
+{
+	int error;
+
+	GIT_REFCOUNT_INC(index);
+
+	writer->index = index;
+
+	if (!index->index_file_path)
+		return create_index_error(-1,
+			"failed to write index: The index is in-memory only");
+
+	if ((error = git_filebuf_open(
+		&writer->file, index->index_file_path, GIT_FILEBUF_HASH_CONTENTS, GIT_INDEX_FILE_MODE)) < 0) {
+
+		if (error == GIT_ELOCKED)
+			giterr_set(GITERR_INDEX, "the index is locked; this might be due to a concurrent or crashed process");
+
+		return error;
+	}
+
+	writer->should_write = 1;
+
+	return 0;
+}
+
+int git_indexwriter_init_for_operation(
+	git_indexwriter *writer,
+	git_repository *repo,
+	unsigned int *checkout_strategy)
+{
+	git_index *index;
+	int error;
+
+	if ((error = git_repository_index__weakptr(&index, repo)) < 0 ||
+		(error = git_indexwriter_init(writer, index)) < 0)
+		return error;
+
+	writer->should_write = (*checkout_strategy & GIT_CHECKOUT_DONT_WRITE_INDEX) == 0;
+	*checkout_strategy |= GIT_CHECKOUT_DONT_WRITE_INDEX;
+
+	return 0;
+}
+
+int git_indexwriter_commit(git_indexwriter *writer)
+{
+	int error;
+	git_oid checksum = {{ 0 }};
+
+	if (!writer->should_write)
+		return 0;
+
+	git_vector_sort(&writer->index->entries);
+	git_vector_sort(&writer->index->reuc);
+
+	if ((error = write_index(&checksum, writer->index, &writer->file)) < 0) {
+		git_indexwriter_cleanup(writer);
+		return error;
+	}
+
+	if ((error = git_filebuf_commit(&writer->file)) < 0)
+		return error;
+
+	if ((error = git_futils_filestamp_check(
+		&writer->index->stamp, writer->index->index_file_path)) < 0) {
+		giterr_set(GITERR_OS, "could not read index timestamp");
+		return -1;
+	}
+
+	writer->index->on_disk = 1;
+	git_oid_cpy(&writer->index->checksum, &checksum);
+
+	git_index_free(writer->index);
+	writer->index = NULL;
+
+	return 0;
+}
+
+void git_indexwriter_cleanup(git_indexwriter *writer)
+{
+	git_filebuf_cleanup(&writer->file);
+
+	git_index_free(writer->index);
+	writer->index = NULL;
+}

vendor/libgit2-sys/libgit2/src/index.h

diff --git a/vendor/libgit2-sys/libgit2/src/index.h b/vendor/libgit2-sys/libgit2/src/index.h
new file mode 100644
index 0000000..0f1c095
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/index.h
@@ -0,0 +1,175 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_index_h__
+#define INCLUDE_index_h__
+
+#include "common.h"
+
+#include "fileops.h"
+#include "filebuf.h"
+#include "vector.h"
+#include "idxmap.h"
+#include "tree-cache.h"
+#include "git2/odb.h"
+#include "git2/index.h"
+
+#define GIT_INDEX_FILE "index"
+#define GIT_INDEX_FILE_MODE 0666
+
+struct git_index {
+	git_refcount rc;
+
+	char *index_file_path;
+	git_futils_filestamp stamp;
+	git_oid checksum;   /* checksum at the end of the file */
+
+	git_vector entries;
+	git_idxmap *entries_map;
+
+	git_vector deleted; /* deleted entries if readers > 0 */
+	git_atomic readers; /* number of active iterators */
+
+	unsigned int on_disk:1;
+	unsigned int ignore_case:1;
+	unsigned int distrust_filemode:1;
+	unsigned int no_symlinks:1;
+
+	git_tree_cache *tree;
+	git_pool tree_pool;
+
+	git_vector names;
+	git_vector reuc;
+
+	git_vector_cmp entries_cmp_path;
+	git_vector_cmp entries_search;
+	git_vector_cmp entries_search_path;
+	git_vector_cmp reuc_search;
+
+	unsigned int version;
+};
+
+struct git_index_conflict_iterator {
+	git_index *index;
+	size_t cur;
+};
+
+extern void git_index_entry__init_from_stat(
+	git_index_entry *entry, struct stat *st, bool trust_mode);
+
+/* Index entry comparison functions for array sorting */
+extern int git_index_entry_cmp(const void *a, const void *b);
+extern int git_index_entry_icmp(const void *a, const void *b);
+
+/* Index entry search functions for search using a search spec */
+extern int git_index_entry_srch(const void *a, const void *b);
+extern int git_index_entry_isrch(const void *a, const void *b);
+
+/* Index time handling functions */
+GIT_INLINE(bool) git_index_time_eq(const git_index_time *one, const git_index_time *two)
+{
+	if (one->seconds != two->seconds)
+		return false;
+
+#ifdef GIT_USE_NSEC
+	if (one->nanoseconds != two->nanoseconds)
+		return false;
+#endif
+
+	return true;
+}
+
+/*
+ * Test if the given index time is newer than the given existing index entry.
+ * If the timestamps are exactly equivalent, then the given index time is
+ * considered "racily newer" than the existing index entry.
+ */
+GIT_INLINE(bool) git_index_entry_newer_than_index(
+	const git_index_entry *entry, git_index *index)
+{
+	/* If we never read the index, we can't have this race either */
+	if (!index || index->stamp.mtime.tv_sec == 0)
+		return false;
+
+	/* If the timestamp is the same or newer than the index, it's racy */
+#if defined(GIT_USE_NSEC)
+	if ((int32_t)index->stamp.mtime.tv_sec < entry->mtime.seconds)
+		return true;
+	else if ((int32_t)index->stamp.mtime.tv_sec > entry->mtime.seconds)
+		return false;
+	else
+		return (uint32_t)index->stamp.mtime.tv_nsec <= entry->mtime.nanoseconds;
+#else
+	return ((int32_t)index->stamp.mtime.tv_sec) <= entry->mtime.seconds;
+#endif
+}
+
+/* Search index for `path`, returning GIT_ENOTFOUND if it does not exist
+ * (but not setting an error message).
+ *
+ * `at_pos` is set to the position where it is or would be inserted.
+ * Pass `path_len` as strlen of path or 0 to call strlen internally.
+ */
+extern int git_index__find_pos(
+	size_t *at_pos, git_index *index, const char *path, size_t path_len, int stage);
+
+extern int git_index__fill(git_index *index, const git_vector *source_entries);
+
+extern void git_index__set_ignore_case(git_index *index, bool ignore_case);
+
+extern unsigned int git_index__create_mode(unsigned int mode);
+
+GIT_INLINE(const git_futils_filestamp *) git_index__filestamp(git_index *index)
+{
+   return &index->stamp;
+}
+
+extern int git_index__changed_relative_to(git_index *index, const git_oid *checksum);
+
+/* Copy the current entries vector *and* increment the index refcount.
+ * Call `git_index__release_snapshot` when done.
+ */
+extern int git_index_snapshot_new(git_vector *snap, git_index *index);
+extern void git_index_snapshot_release(git_vector *snap, git_index *index);
+
+/* Allow searching in a snapshot; entries must already be sorted! */
+extern int git_index_snapshot_find(
+	size_t *at_pos, git_vector *snap, git_vector_cmp entry_srch,
+	const char *path, size_t path_len, int stage);
+
+/* Replace an index with a new index */
+int git_index_read_index(git_index *index, const git_index *new_index);
+
+typedef struct {
+	git_index *index;
+	git_filebuf file;
+	unsigned int should_write:1;
+} git_indexwriter;
+
+#define GIT_INDEXWRITER_INIT { NULL, GIT_FILEBUF_INIT }
+
+/* Lock the index for eventual writing. */
+extern int git_indexwriter_init(git_indexwriter *writer, git_index *index);
+
+/* Lock the index for eventual writing by a repository operation: a merge,
+ * revert, cherry-pick or a rebase.  Note that the given checkout strategy
+ * will be updated for the operation's use so that checkout will not write
+ * the index.
+ */
+extern int git_indexwriter_init_for_operation(
+	git_indexwriter *writer,
+	git_repository *repo,
+	unsigned int *checkout_strategy);
+
+/* Write the index and unlock it. */
+extern int git_indexwriter_commit(git_indexwriter *writer);
+
+/* Cleanup an index writing session, unlocking the file (if it is still
+ * locked and freeing any data structures.
+ */
+extern void git_indexwriter_cleanup(git_indexwriter *writer);
+
+#endif

vendor/libgit2-sys/libgit2/src/indexer.c

diff --git a/vendor/libgit2-sys/libgit2/src/indexer.c b/vendor/libgit2-sys/libgit2/src/indexer.c
new file mode 100644
index 0000000..c0976f2
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/indexer.c
@@ -0,0 +1,1166 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "indexer.h"
+
+#include "git2/indexer.h"
+#include "git2/object.h"
+
+#include "pack.h"
+#include "mwindow.h"
+#include "posix.h"
+#include "pack.h"
+#include "filebuf.h"
+#include "oid.h"
+#include "oidmap.h"
+#include "zstream.h"
+#include "object.h"
+
+extern git_mutex git__mwindow_mutex;
+
+#define UINT31_MAX (0x7FFFFFFF)
+
+struct entry {
+	git_oid oid;
+	uint32_t crc;
+	uint32_t offset;
+	uint64_t offset_long;
+};
+
+struct git_indexer {
+	unsigned int parsed_header :1,
+		pack_committed :1,
+		have_stream :1,
+		have_delta :1,
+		do_fsync :1;
+	struct git_pack_header hdr;
+	struct git_pack_file *pack;
+	unsigned int mode;
+	git_off_t off;
+	git_off_t entry_start;
+	git_packfile_stream stream;
+	size_t nr_objects;
+	git_vector objects;
+	git_vector deltas;
+	unsigned int fanout[256];
+	git_hash_ctx hash_ctx;
+	git_oid hash;
+	git_transfer_progress_cb progress_cb;
+	void *progress_payload;
+	char objbuf[8*1024];
+
+	/* Needed to look up objects which we want to inject to fix a thin pack */
+	git_odb *odb;
+
+	/* Fields for calculating the packfile trailer (hash of everything before it) */
+	char inbuf[GIT_OID_RAWSZ];
+	size_t inbuf_len;
+	git_hash_ctx trailer;
+};
+
+struct delta_info {
+	git_off_t delta_off;
+};
+
+const git_oid *git_indexer_hash(const git_indexer *idx)
+{
+	return &idx->hash;
+}
+
+static int parse_header(struct git_pack_header *hdr, struct git_pack_file *pack)
+{
+	int error;
+	git_map map;
+
+	if ((error = p_mmap(&map, sizeof(*hdr), GIT_PROT_READ, GIT_MAP_SHARED, pack->mwf.fd, 0)) < 0)
+		return error;
+
+	memcpy(hdr, map.data, sizeof(*hdr));
+	p_munmap(&map);
+
+	/* Verify we recognize this pack file format. */
+	if (hdr->hdr_signature != ntohl(PACK_SIGNATURE)) {
+		giterr_set(GITERR_INDEXER, "wrong pack signature");
+		return -1;
+	}
+
+	if (!pack_version_ok(hdr->hdr_version)) {
+		giterr_set(GITERR_INDEXER, "wrong pack version");
+		return -1;
+	}
+
+	return 0;
+}
+
+static int objects_cmp(const void *a, const void *b)
+{
+	const struct entry *entrya = a;
+	const struct entry *entryb = b;
+
+	return git_oid__cmp(&entrya->oid, &entryb->oid);
+}
+
+int git_indexer_new(
+		git_indexer **out,
+		const char *prefix,
+		unsigned int mode,
+		git_odb *odb,
+		git_transfer_progress_cb progress_cb,
+		void *progress_payload)
+{
+	git_indexer *idx;
+	git_buf path = GIT_BUF_INIT, tmp_path = GIT_BUF_INIT;
+	static const char suff[] = "/pack";
+	int error, fd = -1;
+
+	idx = git__calloc(1, sizeof(git_indexer));
+	GITERR_CHECK_ALLOC(idx);
+	idx->odb = odb;
+	idx->progress_cb = progress_cb;
+	idx->progress_payload = progress_payload;
+	idx->mode = mode ? mode : GIT_PACK_FILE_MODE;
+	git_hash_ctx_init(&idx->hash_ctx);
+	git_hash_ctx_init(&idx->trailer);
+
+	if (git_repository__fsync_gitdir)
+		idx->do_fsync = 1;
+
+	error = git_buf_joinpath(&path, prefix, suff);
+	if (error < 0)
+		goto cleanup;
+
+	fd = git_futils_mktmp(&tmp_path, git_buf_cstr(&path), idx->mode);
+	git_buf_free(&path);
+	if (fd < 0)
+		goto cleanup;
+
+	error = git_packfile_alloc(&idx->pack, git_buf_cstr(&tmp_path));
+	git_buf_free(&tmp_path);
+
+	if (error < 0)
+		goto cleanup;
+
+	idx->pack->mwf.fd = fd;
+	if ((error = git_mwindow_file_register(&idx->pack->mwf)) < 0)
+		goto cleanup;
+
+	*out = idx;
+	return 0;
+
+cleanup:
+	if (fd != -1)
+		p_close(fd);
+
+	if (git_buf_len(&tmp_path) > 0)
+		p_unlink(git_buf_cstr(&tmp_path));
+
+	if (idx->pack != NULL)
+		p_unlink(idx->pack->pack_name);
+
+	git_buf_free(&path);
+	git_buf_free(&tmp_path);
+	git__free(idx);
+	return -1;
+}
+
+void git_indexer__set_fsync(git_indexer *idx, int do_fsync)
+{
+	idx->do_fsync = !!do_fsync;
+}
+
+/* Try to store the delta so we can try to resolve it later */
+static int store_delta(git_indexer *idx)
+{
+	struct delta_info *delta;
+
+	delta = git__calloc(1, sizeof(struct delta_info));
+	GITERR_CHECK_ALLOC(delta);
+	delta->delta_off = idx->entry_start;
+
+	if (git_vector_insert(&idx->deltas, delta) < 0)
+		return -1;
+
+	return 0;
+}
+
+static int hash_header(git_hash_ctx *ctx, git_off_t len, git_otype type)
+{
+	char buffer[64];
+	size_t hdrlen;
+	int error;
+
+	if ((error = git_odb__format_object_header(&hdrlen,
+		buffer, sizeof(buffer), (size_t)len, type)) < 0)
+		return error;
+
+	return git_hash_update(ctx, buffer, hdrlen);
+}
+
+static int hash_object_stream(git_indexer*idx, git_packfile_stream *stream)
+{
+	ssize_t read;
+
+	assert(idx && stream);
+
+	do {
+		if ((read = git_packfile_stream_read(stream, idx->objbuf, sizeof(idx->objbuf))) < 0)
+			break;
+
+		git_hash_update(&idx->hash_ctx, idx->objbuf, read);
+	} while (read > 0);
+
+	if (read < 0)
+		return (int)read;
+
+	return 0;
+}
+
+/* In order to create the packfile stream, we need to skip over the delta base description */
+static int advance_delta_offset(git_indexer *idx, git_otype type)
+{
+	git_mwindow *w = NULL;
+
+	assert(type == GIT_OBJ_REF_DELTA || type == GIT_OBJ_OFS_DELTA);
+
+	if (type == GIT_OBJ_REF_DELTA) {
+		idx->off += GIT_OID_RAWSZ;
+	} else {
+		git_off_t base_off = get_delta_base(idx->pack, &w, &idx->off, type, idx->entry_start);
+		git_mwindow_close(&w);
+		if (base_off < 0)
+			return (int)base_off;
+	}
+
+	return 0;
+}
+
+/* Read from the stream and discard any output */
+static int read_object_stream(git_indexer *idx, git_packfile_stream *stream)
+{
+	ssize_t read;
+
+	assert(stream);
+
+	do {
+		read = git_packfile_stream_read(stream, idx->objbuf, sizeof(idx->objbuf));
+	} while (read > 0);
+
+	if (read < 0)
+		return (int)read;
+
+	return 0;
+}
+
+static int crc_object(uint32_t *crc_out, git_mwindow_file *mwf, git_off_t start, git_off_t size)
+{
+	void *ptr;
+	uint32_t crc;
+	unsigned int left, len;
+	git_mwindow *w = NULL;
+
+	crc = crc32(0L, Z_NULL, 0);
+	while (size) {
+		ptr = git_mwindow_open(mwf, &w, start, (size_t)size, &left);
+		if (ptr == NULL)
+			return -1;
+
+		len = min(left, (unsigned int)size);
+		crc = crc32(crc, ptr, len);
+		size -= len;
+		start += len;
+		git_mwindow_close(&w);
+	}
+
+	*crc_out = htonl(crc);
+	return 0;
+}
+
+static int store_object(git_indexer *idx)
+{
+	int i, error;
+	khiter_t k;
+	git_oid oid;
+	struct entry *entry;
+	git_off_t entry_size;
+	struct git_pack_entry *pentry;
+	git_off_t entry_start = idx->entry_start;
+
+	entry = git__calloc(1, sizeof(*entry));
+	GITERR_CHECK_ALLOC(entry);
+
+	pentry = git__calloc(1, sizeof(struct git_pack_entry));
+	GITERR_CHECK_ALLOC(pentry);
+
+	git_hash_final(&oid, &idx->hash_ctx);
+	entry_size = idx->off - entry_start;
+	if (entry_start > UINT31_MAX) {
+		entry->offset = UINT32_MAX;
+		entry->offset_long = entry_start;
+	} else {
+		entry->offset = (uint32_t)entry_start;
+	}
+
+	git_oid_cpy(&pentry->sha1, &oid);
+	pentry->offset = entry_start;
+
+	k = git_oidmap_put(idx->pack->idx_cache, &pentry->sha1, &error);
+	if (error == -1) {
+		git__free(pentry);
+		giterr_set_oom();
+		goto on_error;
+	}
+
+	if (error == 0) {
+		giterr_set(GITERR_INDEXER, "duplicate object %s found in pack", git_oid_tostr_s(&pentry->sha1));
+		git__free(pentry);
+		goto on_error;
+	}
+
+
+	git_oidmap_set_value_at(idx->pack->idx_cache, k, pentry);
+
+	git_oid_cpy(&entry->oid, &oid);
+
+	if (crc_object(&entry->crc, &idx->pack->mwf, entry_start, entry_size) < 0)
+		goto on_error;
+
+	/* Add the object to the list */
+	if (git_vector_insert(&idx->objects, entry) < 0)
+		goto on_error;
+
+	for (i = oid.id[0]; i < 256; ++i) {
+		idx->fanout[i]++;
+	}
+
+	return 0;
+
+on_error:
+	git__free(entry);
+
+	return -1;
+}
+
+GIT_INLINE(bool) has_entry(git_indexer *idx, git_oid *id)
+{
+	return git_oidmap_exists(idx->pack->idx_cache, id);
+}
+
+static int save_entry(git_indexer *idx, struct entry *entry, struct git_pack_entry *pentry, git_off_t entry_start)
+{
+	int i, error;
+	khiter_t k;
+
+	if (entry_start > UINT31_MAX) {
+		entry->offset = UINT32_MAX;
+		entry->offset_long = entry_start;
+	} else {
+		entry->offset = (uint32_t)entry_start;
+	}
+
+	pentry->offset = entry_start;
+	k = git_oidmap_put(idx->pack->idx_cache, &pentry->sha1, &error);
+
+	if (error <= 0) {
+		giterr_set(GITERR_INDEXER, "cannot insert object into pack");
+		return -1;
+	}
+
+	git_oidmap_set_value_at(idx->pack->idx_cache, k, pentry);
+
+	/* Add the object to the list */
+	if (git_vector_insert(&idx->objects, entry) < 0)
+		return -1;
+
+	for (i = entry->oid.id[0]; i < 256; ++i) {
+		idx->fanout[i]++;
+	}
+
+	return 0;
+}
+
+static int hash_and_save(git_indexer *idx, git_rawobj *obj, git_off_t entry_start)
+{
+	git_oid oid;
+	size_t entry_size;
+	struct entry *entry;
+	struct git_pack_entry *pentry = NULL;
+
+	entry = git__calloc(1, sizeof(*entry));
+	GITERR_CHECK_ALLOC(entry);
+
+	if (git_odb__hashobj(&oid, obj) < 0) {
+		giterr_set(GITERR_INDEXER, "failed to hash object");
+		goto on_error;
+	}
+
+	pentry = git__calloc(1, sizeof(struct git_pack_entry));
+	GITERR_CHECK_ALLOC(pentry);
+
+	git_oid_cpy(&pentry->sha1, &oid);
+	git_oid_cpy(&entry->oid, &oid);
+	entry->crc = crc32(0L, Z_NULL, 0);
+
+	entry_size = (size_t)(idx->off - entry_start);
+	if (crc_object(&entry->crc, &idx->pack->mwf, entry_start, entry_size) < 0)
+		goto on_error;
+
+	return save_entry(idx, entry, pentry, entry_start);
+
+on_error:
+	git__free(pentry);
+	git__free(entry);
+	git__free(obj->data);
+	return -1;
+}
+
+static int do_progress_callback(git_indexer *idx, git_transfer_progress *stats)
+{
+	if (idx->progress_cb)
+		return giterr_set_after_callback_function(
+			idx->progress_cb(stats, idx->progress_payload),
+			"indexer progress");
+	return 0;
+}
+
+/* Hash everything but the last 20B of input */
+static void hash_partially(git_indexer *idx, const uint8_t *data, size_t size)
+{
+	size_t to_expell, to_keep;
+
+	if (size == 0)
+		return;
+
+	/* Easy case, dump the buffer and the data minus the last 20 bytes */
+	if (size >= GIT_OID_RAWSZ) {
+		git_hash_update(&idx->trailer, idx->inbuf, idx->inbuf_len);
+		git_hash_update(&idx->trailer, data, size - GIT_OID_RAWSZ);
+
+		data += size - GIT_OID_RAWSZ;
+		memcpy(idx->inbuf, data, GIT_OID_RAWSZ);
+		idx->inbuf_len = GIT_OID_RAWSZ;
+		return;
+	}
+
+	/* We can just append */
+	if (idx->inbuf_len + size <= GIT_OID_RAWSZ) {
+		memcpy(idx->inbuf + idx->inbuf_len, data, size);
+		idx->inbuf_len += size;
+		return;
+	}
+
+	/* We need to partially drain the buffer and then append */
+	to_keep   = GIT_OID_RAWSZ - size;
+	to_expell = idx->inbuf_len - to_keep;
+
+	git_hash_update(&idx->trailer, idx->inbuf, to_expell);
+
+	memmove(idx->inbuf, idx->inbuf + to_expell, to_keep);
+	memcpy(idx->inbuf + to_keep, data, size);
+	idx->inbuf_len += size - to_expell;
+}
+
+static int write_at(git_indexer *idx, const void *data, git_off_t offset, size_t size)
+{
+	git_file fd = idx->pack->mwf.fd;
+	size_t mmap_alignment;
+	size_t page_offset;
+	git_off_t page_start;
+	unsigned char *map_data;
+	git_map map;
+	int error;
+
+	assert(data && size);
+
+	if ((error = git__mmap_alignment(&mmap_alignment)) < 0)
+		return error;
+
+	/* the offset needs to be at the mmap boundary for the platform */
+	page_offset = offset % mmap_alignment;
+	page_start = offset - page_offset;
+
+	if ((error = p_mmap(&map, page_offset + size, GIT_PROT_WRITE, GIT_MAP_SHARED, fd, page_start)) < 0)
+		return error;
+
+	map_data = (unsigned char *)map.data;
+	memcpy(map_data + page_offset, data, size);
+	p_munmap(&map);
+
+	return 0;
+}
+
+static int append_to_pack(git_indexer *idx, const void *data, size_t size)
+{
+	git_off_t new_size;
+	size_t mmap_alignment;
+	size_t page_offset;
+	git_off_t page_start;
+	git_off_t current_size = idx->pack->mwf.size;
+	int fd = idx->pack->mwf.fd;
+	int error;
+
+	if (!size)
+		return 0;
+
+	if ((error = git__mmap_alignment(&mmap_alignment)) < 0)
+		return error;
+
+	/* Write a single byte to force the file system to allocate space now or
+	 * report an error, since we can't report errors when writing using mmap.
+	 * Round the size up to the nearest page so that we only need to perform file
+	 * I/O when we add a page, instead of whenever we write even a single byte. */
+	new_size = current_size + size;
+	page_offset = new_size % mmap_alignment;
+	page_start = new_size - page_offset;
+
+	if (p_lseek(fd, page_start + mmap_alignment - 1, SEEK_SET) < 0 ||
+	    p_write(idx->pack->mwf.fd, data, 1) < 0) {
+		giterr_set(GITERR_OS, "cannot extend packfile '%s'", idx->pack->pack_name);
+		return -1;
+	}
+
+	return write_at(idx, data, idx->pack->mwf.size, size);
+}
+
+int git_indexer_append(git_indexer *idx, const void *data, size_t size, git_transfer_progress *stats)
+{
+	int error = -1;
+	size_t processed;
+	struct git_pack_header *hdr = &idx->hdr;
+	git_mwindow_file *mwf = &idx->pack->mwf;
+
+	assert(idx && data && stats);
+
+	processed = stats->indexed_objects;
+
+	if ((error = append_to_pack(idx, data, size)) < 0)
+		return error;
+
+	hash_partially(idx, data, (int)size);
+
+	/* Make sure we set the new size of the pack */
+	idx->pack->mwf.size += size;
+
+	if (!idx->parsed_header) {
+		unsigned int total_objects;
+
+		if ((unsigned)idx->pack->mwf.size < sizeof(struct git_pack_header))
+			return 0;
+
+		if ((error = parse_header(&idx->hdr, idx->pack)) < 0)
+			return error;
+
+		idx->parsed_header = 1;
+		idx->nr_objects = ntohl(hdr->hdr_entries);
+		idx->off = sizeof(struct git_pack_header);
+
+		/* for now, limit to 2^32 objects */
+		assert(idx->nr_objects == (size_t)((unsigned int)idx->nr_objects));
+		if (idx->nr_objects == (size_t)((unsigned int)idx->nr_objects))
+			total_objects = (unsigned int)idx->nr_objects;
+		else
+			total_objects = UINT_MAX;
+
+		idx->pack->idx_cache = git_oidmap_alloc();
+		GITERR_CHECK_ALLOC(idx->pack->idx_cache);
+
+		idx->pack->has_cache = 1;
+		if (git_vector_init(&idx->objects, total_objects, objects_cmp) < 0)
+			return -1;
+
+		if (git_vector_init(&idx->deltas, total_objects / 2, NULL) < 0)
+			return -1;
+
+		stats->received_objects = 0;
+		stats->local_objects = 0;
+		stats->total_deltas = 0;
+		stats->indexed_deltas = 0;
+		processed = stats->indexed_objects = 0;
+		stats->total_objects = total_objects;
+
+		if ((error = do_progress_callback(idx, stats)) != 0)
+			return error;
+	}
+
+	/* Now that we have data in the pack, let's try to parse it */
+
+	/* As the file grows any windows we try to use will be out of date */
+	git_mwindow_free_all(mwf);
+
+	while (processed < idx->nr_objects) {
+		git_packfile_stream *stream = &idx->stream;
+		git_off_t entry_start = idx->off;
+		size_t entry_size;
+		git_otype type;
+		git_mwindow *w = NULL;
+
+		if (idx->pack->mwf.size <= idx->off + 20)
+			return 0;
+
+		if (!idx->have_stream) {
+			error = git_packfile_unpack_header(&entry_size, &type, mwf, &w, &idx->off);
+			if (error == GIT_EBUFS) {
+				idx->off = entry_start;
+				return 0;
+			}
+			if (error < 0)
+				goto on_error;
+
+			git_mwindow_close(&w);
+			idx->entry_start = entry_start;
+			git_hash_init(&idx->hash_ctx);
+
+			if (type == GIT_OBJ_REF_DELTA || type == GIT_OBJ_OFS_DELTA) {
+				error = advance_delta_offset(idx, type);
+				if (error == GIT_EBUFS) {
+					idx->off = entry_start;
+					return 0;
+				}
+				if (error < 0)
+					goto on_error;
+
+				idx->have_delta = 1;
+			} else {
+				idx->have_delta = 0;
+
+				error = hash_header(&idx->hash_ctx, entry_size, type);
+				if (error < 0)
+					goto on_error;
+			}
+
+			idx->have_stream = 1;
+
+			error = git_packfile_stream_open(stream, idx->pack, idx->off);
+			if (error < 0)
+				goto on_error;
+		}
+
+		if (idx->have_delta) {
+			error = read_object_stream(idx, stream);
+		} else {
+			error = hash_object_stream(idx, stream);
+		}
+
+		idx->off = stream->curpos;
+		if (error == GIT_EBUFS)
+			return 0;
+
+		/* We want to free the stream reasorces no matter what here */
+		idx->have_stream = 0;
+		git_packfile_stream_free(stream);
+
+		if (error < 0)
+			goto on_error;
+
+		if (idx->have_delta) {
+			error = store_delta(idx);
+		} else {
+			error = store_object(idx);
+		}
+
+		if (error < 0)
+			goto on_error;
+
+		if (!idx->have_delta) {
+			stats->indexed_objects = (unsigned int)++processed;
+		}
+		stats->received_objects++;
+
+		if ((error = do_progress_callback(idx, stats)) != 0)
+			goto on_error;
+	}
+
+	return 0;
+
+on_error:
+	git_mwindow_free_all(mwf);
+	return error;
+}
+
+static int index_path(git_buf *path, git_indexer *idx, const char *suffix)
+{
+	const char prefix[] = "pack-";
+	size_t slash = (size_t)path->size;
+
+	/* search backwards for '/' */
+	while (slash > 0 && path->ptr[slash - 1] != '/')
+		slash--;
+
+	if (git_buf_grow(path, slash + 1 + strlen(prefix) +
+					 GIT_OID_HEXSZ + strlen(suffix) + 1) < 0)
+		return -1;
+
+	git_buf_truncate(path, slash);
+	git_buf_puts(path, prefix);
+	git_oid_fmt(path->ptr + git_buf_len(path), &idx->hash);
+	path->size += GIT_OID_HEXSZ;
+	git_buf_puts(path, suffix);
+
+	return git_buf_oom(path) ? -1 : 0;
+}
+
+/**
+ * Rewind the packfile by the trailer, as we might need to fix the
+ * packfile by injecting objects at the tail and must overwrite it.
+ */
+static void seek_back_trailer(git_indexer *idx)
+{
+	idx->pack->mwf.size -= GIT_OID_RAWSZ;
+	git_mwindow_free_all(&idx->pack->mwf);
+}
+
+static int inject_object(git_indexer *idx, git_oid *id)
+{
+	git_odb_object *obj;
+	struct entry *entry;
+	struct git_pack_entry *pentry = NULL;
+	git_oid foo = {{0}};
+	unsigned char hdr[64];
+	git_buf buf = GIT_BUF_INIT;
+	git_off_t entry_start;
+	const void *data;
+	size_t len, hdr_len;
+	int error;
+
+	seek_back_trailer(idx);
+	entry_start = idx->pack->mwf.size;
+
+	if (git_odb_read(&obj, idx->odb, id) < 0) {
+		giterr_set(GITERR_INDEXER, "missing delta bases");
+		return -1;
+	}
+
+	data = git_odb_object_data(obj);
+	len = git_odb_object_size(obj);
+
+	entry = git__calloc(1, sizeof(*entry));
+	GITERR_CHECK_ALLOC(entry);
+
+	entry->crc = crc32(0L, Z_NULL, 0);
+
+	/* Write out the object header */
+	hdr_len = git_packfile__object_header(hdr, len, git_odb_object_type(obj));
+	if ((error = append_to_pack(idx, hdr, hdr_len)) < 0)
+		goto cleanup;
+
+	idx->pack->mwf.size += hdr_len;
+	entry->crc = crc32(entry->crc, hdr, (uInt)hdr_len);
+
+	if ((error = git_zstream_deflatebuf(&buf, data, len)) < 0)
+		goto cleanup;
+
+	/* And then the compressed object */
+	if ((error = append_to_pack(idx, buf.ptr, buf.size)) < 0)
+		goto cleanup;
+
+	idx->pack->mwf.size += buf.size;
+	entry->crc = htonl(crc32(entry->crc, (unsigned char *)buf.ptr, (uInt)buf.size));
+	git_buf_free(&buf);
+
+	/* Write a fake trailer so the pack functions play ball */
+
+	if ((error = append_to_pack(idx, &foo, GIT_OID_RAWSZ)) < 0)
+		goto cleanup;
+
+	idx->pack->mwf.size += GIT_OID_RAWSZ;
+
+	pentry = git__calloc(1, sizeof(struct git_pack_entry));
+	GITERR_CHECK_ALLOC(pentry);
+
+	git_oid_cpy(&pentry->sha1, id);
+	git_oid_cpy(&entry->oid, id);
+	idx->off = entry_start + hdr_len + len;
+
+	error = save_entry(idx, entry, pentry, entry_start);
+
+cleanup:
+	if (error) {
+		git__free(entry);
+		git__free(pentry);
+	}
+
+	git_odb_object_free(obj);
+	return error;
+}
+
+static int fix_thin_pack(git_indexer *idx, git_transfer_progress *stats)
+{
+	int error, found_ref_delta = 0;
+	unsigned int i;
+	struct delta_info *delta;
+	size_t size;
+	git_otype type;
+	git_mwindow *w = NULL;
+	git_off_t curpos = 0;
+	unsigned char *base_info;
+	unsigned int left = 0;
+	git_oid base;
+
+	assert(git_vector_length(&idx->deltas) > 0);
+
+	if (idx->odb == NULL) {
+		giterr_set(GITERR_INDEXER, "cannot fix a thin pack without an ODB");
+		return -1;
+	}
+
+	/* Loop until we find the first REF delta */
+	git_vector_foreach(&idx->deltas, i, delta) {
+		if (!delta)
+			continue;
+
+		curpos = delta->delta_off;
+		error = git_packfile_unpack_header(&size, &type, &idx->pack->mwf, &w, &curpos);
+		if (error < 0)
+			return error;
+
+		if (type == GIT_OBJ_REF_DELTA) {
+			found_ref_delta = 1;
+			break;
+		}
+	}
+
+	if (!found_ref_delta) {
+		giterr_set(GITERR_INDEXER, "no REF_DELTA found, cannot inject object");
+		return -1;
+	}
+
+	/* curpos now points to the base information, which is an OID */
+	base_info = git_mwindow_open(&idx->pack->mwf, &w, curpos, GIT_OID_RAWSZ, &left);
+	if (base_info == NULL) {
+		giterr_set(GITERR_INDEXER, "failed to map delta information");
+		return -1;
+	}
+
+	git_oid_fromraw(&base, base_info);
+	git_mwindow_close(&w);
+
+	if (has_entry(idx, &base))
+		return 0;
+
+	if (inject_object(idx, &base) < 0)
+		return -1;
+
+	stats->local_objects++;
+
+	return 0;
+}
+
+static int resolve_deltas(git_indexer *idx, git_transfer_progress *stats)
+{
+	unsigned int i;
+	int error;
+	struct delta_info *delta;
+	int progressed = 0, non_null = 0, progress_cb_result;
+
+	while (idx->deltas.length > 0) {
+		progressed = 0;
+		non_null = 0;
+		git_vector_foreach(&idx->deltas, i, delta) {
+			git_rawobj obj = {NULL};
+
+			if (!delta)
+				continue;
+
+			non_null = 1;
+			idx->off = delta->delta_off;
+			if ((error = git_packfile_unpack(&obj, idx->pack, &idx->off)) < 0) {
+				if (error == GIT_PASSTHROUGH) {
+					/* We have not seen the base object, we'll try again later. */
+					continue;
+				}
+				return -1;
+			}
+
+			if (hash_and_save(idx, &obj, delta->delta_off) < 0)
+				continue;
+
+			git__free(obj.data);
+			stats->indexed_objects++;
+			stats->indexed_deltas++;
+			progressed = 1;
+			if ((progress_cb_result = do_progress_callback(idx, stats)) < 0)
+				return progress_cb_result;
+
+			/* remove from the list */
+			git_vector_set(NULL, &idx->deltas, i, NULL);
+			git__free(delta);
+		}
+
+		/* if none were actually set, we're done */
+		if (!non_null)
+			break;
+
+		if (!progressed && (fix_thin_pack(idx, stats) < 0)) {
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+static int update_header_and_rehash(git_indexer *idx, git_transfer_progress *stats)
+{
+	void *ptr;
+	size_t chunk = 1024*1024;
+	git_off_t hashed = 0;
+	git_mwindow *w = NULL;
+	git_mwindow_file *mwf;
+	unsigned int left;
+
+	mwf = &idx->pack->mwf;
+
+	git_hash_init(&idx->trailer);
+
+
+	/* Update the header to include the numer of local objects we injected */
+	idx->hdr.hdr_entries = htonl(stats->total_objects + stats->local_objects);
+	if (write_at(idx, &idx->hdr, 0, sizeof(struct git_pack_header)) < 0)
+		return -1;
+
+	/*
+	 * We now use the same technique as before to determine the
+	 * hash. We keep reading up to the end and let
+	 * hash_partially() keep the existing trailer out of the
+	 * calculation.
+	 */
+	git_mwindow_free_all(mwf);
+	idx->inbuf_len = 0;
+	while (hashed < mwf->size) {
+		ptr = git_mwindow_open(mwf, &w, hashed, chunk, &left);
+		if (ptr == NULL)
+			return -1;
+
+		hash_partially(idx, ptr, left);
+		hashed += left;
+
+		git_mwindow_close(&w);
+	}
+
+	return 0;
+}
+
+int git_indexer_commit(git_indexer *idx, git_transfer_progress *stats)
+{
+	git_mwindow *w = NULL;
+	unsigned int i, long_offsets = 0, left;
+	int error;
+	struct git_pack_idx_header hdr;
+	git_buf filename = GIT_BUF_INIT;
+	struct entry *entry;
+	git_oid trailer_hash, file_hash;
+	git_filebuf index_file = {0};
+	void *packfile_trailer;
+
+	if (!idx->parsed_header) {
+		giterr_set(GITERR_INDEXER, "incomplete pack header");
+		return -1;
+	}
+
+	/* Test for this before resolve_deltas(), as it plays with idx->off */
+	if (idx->off + 20 < idx->pack->mwf.size) {
+		giterr_set(GITERR_INDEXER, "unexpected data at the end of the pack");
+		return -1;
+	}
+	if (idx->off + 20 > idx->pack->mwf.size) {
+		giterr_set(GITERR_INDEXER, "missing trailer at the end of the pack");
+		return -1;
+	}
+
+	packfile_trailer = git_mwindow_open(&idx->pack->mwf, &w, idx->pack->mwf.size - GIT_OID_RAWSZ, GIT_OID_RAWSZ, &left);
+	if (packfile_trailer == NULL) {
+		git_mwindow_close(&w);
+		goto on_error;
+	}
+
+	/* Compare the packfile trailer as it was sent to us and what we calculated */
+	git_oid_fromraw(&file_hash, packfile_trailer);
+	git_mwindow_close(&w);
+
+	git_hash_final(&trailer_hash, &idx->trailer);
+	if (git_oid_cmp(&file_hash, &trailer_hash)) {
+		giterr_set(GITERR_INDEXER, "packfile trailer mismatch");
+		return -1;
+	}
+
+	/* Freeze the number of deltas */
+	stats->total_deltas = stats->total_objects - stats->indexed_objects;
+
+	if ((error = resolve_deltas(idx, stats)) < 0)
+		return error;
+
+	if (stats->indexed_objects != stats->total_objects) {
+		giterr_set(GITERR_INDEXER, "early EOF");
+		return -1;
+	}
+
+	if (stats->local_objects > 0) {
+		if (update_header_and_rehash(idx, stats) < 0)
+			return -1;
+
+		git_hash_final(&trailer_hash, &idx->trailer);
+		write_at(idx, &trailer_hash, idx->pack->mwf.size - GIT_OID_RAWSZ, GIT_OID_RAWSZ);
+	}
+
+	git_vector_sort(&idx->objects);
+
+	/* Use the trailer hash as the pack file name to ensure
+	 * files with different contents have different names */
+	git_oid_cpy(&idx->hash, &trailer_hash);
+
+	git_buf_sets(&filename, idx->pack->pack_name);
+	git_buf_shorten(&filename, strlen("pack"));
+	git_buf_puts(&filename, "idx");
+	if (git_buf_oom(&filename))
+		return -1;
+
+	if (git_filebuf_open(&index_file, filename.ptr,
+		GIT_FILEBUF_HASH_CONTENTS |
+		(idx->do_fsync ? GIT_FILEBUF_FSYNC : 0),
+		idx->mode) < 0)
+		goto on_error;
+
+	/* Write out the header */
+	hdr.idx_signature = htonl(PACK_IDX_SIGNATURE);
+	hdr.idx_version = htonl(2);
+	git_filebuf_write(&index_file, &hdr, sizeof(hdr));
+
+	/* Write out the fanout table */
+	for (i = 0; i < 256; ++i) {
+		uint32_t n = htonl(idx->fanout[i]);
+		git_filebuf_write(&index_file, &n, sizeof(n));
+	}
+
+	/* Write out the object names (SHA-1 hashes) */
+	git_vector_foreach(&idx->objects, i, entry) {
+		git_filebuf_write(&index_file, &entry->oid, sizeof(git_oid));
+	}
+
+	/* Write out the CRC32 values */
+	git_vector_foreach(&idx->objects, i, entry) {
+		git_filebuf_write(&index_file, &entry->crc, sizeof(uint32_t));
+	}
+
+	/* Write out the offsets */
+	git_vector_foreach(&idx->objects, i, entry) {
+		uint32_t n;
+
+		if (entry->offset == UINT32_MAX)
+			n = htonl(0x80000000 | long_offsets++);
+		else
+			n = htonl(entry->offset);
+
+		git_filebuf_write(&index_file, &n, sizeof(uint32_t));
+	}
+
+	/* Write out the long offsets */
+	git_vector_foreach(&idx->objects, i, entry) {
+		uint32_t split[2];
+
+		if (entry->offset != UINT32_MAX)
+			continue;
+
+		split[0] = htonl(entry->offset_long >> 32);
+		split[1] = htonl(entry->offset_long & 0xffffffff);
+
+		git_filebuf_write(&index_file, &split, sizeof(uint32_t) * 2);
+	}
+
+	/* Write out the packfile trailer to the index */
+	if (git_filebuf_write(&index_file, &trailer_hash, GIT_OID_RAWSZ) < 0)
+		goto on_error;
+
+	/* Write out the hash of the idx */
+	if (git_filebuf_hash(&trailer_hash, &index_file) < 0)
+		goto on_error;
+
+	git_filebuf_write(&index_file, &trailer_hash, sizeof(git_oid));
+
+	/* Figure out what the final name should be */
+	if (index_path(&filename, idx, ".idx") < 0)
+		goto on_error;
+
+	/* Commit file */
+	if (git_filebuf_commit_at(&index_file, filename.ptr) < 0)
+		goto on_error;
+
+	git_mwindow_free_all(&idx->pack->mwf);
+
+	/* Truncate file to undo rounding up to next page_size in append_to_pack */
+	if (p_ftruncate(idx->pack->mwf.fd, idx->pack->mwf.size) < 0) {
+		giterr_set(GITERR_OS, "failed to truncate pack file '%s'", idx->pack->pack_name);
+		return -1;
+	}
+
+	if (idx->do_fsync && p_fsync(idx->pack->mwf.fd) < 0) {
+		giterr_set(GITERR_OS, "failed to fsync packfile");
+		goto on_error;
+	}
+
+	/* We need to close the descriptor here so Windows doesn't choke on commit_at */
+	if (p_close(idx->pack->mwf.fd) < 0) {
+		giterr_set(GITERR_OS, "failed to close packfile");
+		goto on_error;
+	}
+
+	idx->pack->mwf.fd = -1;
+
+	if (index_path(&filename, idx, ".pack") < 0)
+		goto on_error;
+
+	/* And don't forget to rename the packfile to its new place. */
+	if (p_rename(idx->pack->pack_name, git_buf_cstr(&filename)) < 0)
+		goto on_error;
+
+	/* And fsync the parent directory if we're asked to. */
+	if (idx->do_fsync &&
+		git_futils_fsync_parent(git_buf_cstr(&filename)) < 0)
+		goto on_error;
+
+	idx->pack_committed = 1;
+
+	git_buf_free(&filename);
+	return 0;
+
+on_error:
+	git_mwindow_free_all(&idx->pack->mwf);
+	git_filebuf_cleanup(&index_file);
+	git_buf_free(&filename);
+	return -1;
+}
+
+void git_indexer_free(git_indexer *idx)
+{
+	if (idx == NULL)
+		return;
+
+	if (idx->have_stream)
+		git_packfile_stream_free(&idx->stream);
+
+	git_vector_free_deep(&idx->objects);
+
+	if (idx->pack->idx_cache) {
+		struct git_pack_entry *pentry;
+		git_oidmap_foreach_value(idx->pack->idx_cache, pentry, {
+			git__free(pentry);
+		});
+
+		git_oidmap_free(idx->pack->idx_cache);
+	}
+
+	git_vector_free_deep(&idx->deltas);
+
+	if (!git_mutex_lock(&git__mwindow_mutex)) {
+		if (!idx->pack_committed)
+			git_packfile_close(idx->pack, true);
+
+		git_packfile_free(idx->pack);
+		git_mutex_unlock(&git__mwindow_mutex);
+	}
+
+	git_hash_ctx_cleanup(&idx->trailer);
+	git_hash_ctx_cleanup(&idx->hash_ctx);
+	git__free(idx);
+}

vendor/libgit2-sys/libgit2/src/indexer.h

diff --git a/vendor/libgit2-sys/libgit2/src/indexer.h b/vendor/libgit2-sys/libgit2/src/indexer.h
new file mode 100644
index 0000000..8ee6115
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/indexer.h
@@ -0,0 +1,16 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_indexer_h__
+#define INCLUDE_indexer_h__
+
+#include "common.h"
+
+#include "git2/indexer.h"
+
+extern void git_indexer__set_fsync(git_indexer *idx, int do_fsync);
+
+#endif

vendor/libgit2-sys/libgit2/src/integer.h

diff --git a/vendor/libgit2-sys/libgit2/src/integer.h b/vendor/libgit2-sys/libgit2/src/integer.h
new file mode 100644
index 0000000..30528db
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/integer.h
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_integer_h__
+#define INCLUDE_integer_h__
+
+/** @return true if p fits into the range of a size_t */
+GIT_INLINE(int) git__is_sizet(git_off_t p)
+{
+	size_t r = (size_t)p;
+	return p == (git_off_t)r;
+}
+
+/** @return true if p fits into the range of an ssize_t */
+GIT_INLINE(int) git__is_ssizet(size_t p)
+{
+	ssize_t r = (ssize_t)p;
+	return p == (size_t)r;
+}
+
+/** @return true if p fits into the range of a uint32_t */
+GIT_INLINE(int) git__is_uint32(size_t p)
+{
+	uint32_t r = (uint32_t)p;
+	return p == (size_t)r;
+}
+
+/** @return true if p fits into the range of an unsigned long */
+GIT_INLINE(int) git__is_ulong(git_off_t p)
+{
+	unsigned long r = (unsigned long)p;
+	return p == (git_off_t)r;
+}
+
+/** @return true if p fits into the range of an int */
+GIT_INLINE(int) git__is_int(long long p)
+{
+	int r = (int)p;
+	return p == (long long)r;
+}
+
+/**
+ * Sets `one + two` into `out`, unless the arithmetic would overflow.
+ * @return true if the result fits in a `uint64_t`, false on overflow.
+ */
+GIT_INLINE(bool) git__add_uint64_overflow(uint64_t *out, uint64_t one, uint64_t two)
+{
+	if (UINT64_MAX - one < two)
+		return true;
+	*out = one + two;
+	return false;
+}
+
+/* Use clang/gcc compiler intrinsics whenever possible */
+#if (SIZE_MAX == ULONG_MAX) && __has_builtin(__builtin_uaddl_overflow)
+# define git__add_sizet_overflow(out, one, two) \
+	__builtin_uaddl_overflow(one, two, out)
+# define git__multiply_sizet_overflow(out, one, two) \
+	__builtin_umull_overflow(one, two, out)
+#elif (SIZE_MAX == UINT_MAX) && __has_builtin(__builtin_uadd_overflow)
+# define git__add_sizet_overflow(out, one, two) \
+	__builtin_uadd_overflow(one, two, out)
+# define git__multiply_sizet_overflow(out, one, two) \
+	__builtin_umul_overflow(one, two, out)
+#else
+
+/**
+ * Sets `one + two` into `out`, unless the arithmetic would overflow.
+ * @return true if the result fits in a `size_t`, false on overflow.
+ */
+GIT_INLINE(bool) git__add_sizet_overflow(size_t *out, size_t one, size_t two)
+{
+	if (SIZE_MAX - one < two)
+		return true;
+	*out = one + two;
+	return false;
+}
+
+/**
+ * Sets `one * two` into `out`, unless the arithmetic would overflow.
+ * @return true if the result fits in a `size_t`, false on overflow.
+ */
+GIT_INLINE(bool) git__multiply_sizet_overflow(size_t *out, size_t one, size_t two)
+{
+	if (one && SIZE_MAX / one < two)
+		return true;
+	*out = one * two;
+	return false;
+}
+
+#endif
+
+#endif

vendor/libgit2-sys/libgit2/src/iterator.c

diff --git a/vendor/libgit2-sys/libgit2/src/iterator.c b/vendor/libgit2-sys/libgit2/src/iterator.c
new file mode 100644
index 0000000..ff075ce
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/iterator.c
@@ -0,0 +1,2347 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "iterator.h"
+
+#include "tree.h"
+#include "index.h"
+
+#define GIT_ITERATOR_FIRST_ACCESS   (1 << 15)
+#define GIT_ITERATOR_HONOR_IGNORES  (1 << 16)
+#define GIT_ITERATOR_IGNORE_DOT_GIT (1 << 17)
+
+#define iterator__flag(I,F) ((((git_iterator *)(I))->flags & GIT_ITERATOR_ ## F) != 0)
+#define iterator__ignore_case(I)       iterator__flag(I,IGNORE_CASE)
+#define iterator__include_trees(I)     iterator__flag(I,INCLUDE_TREES)
+#define iterator__dont_autoexpand(I)   iterator__flag(I,DONT_AUTOEXPAND)
+#define iterator__do_autoexpand(I)    !iterator__flag(I,DONT_AUTOEXPAND)
+#define iterator__include_conflicts(I) iterator__flag(I,INCLUDE_CONFLICTS)
+#define iterator__has_been_accessed(I) iterator__flag(I,FIRST_ACCESS)
+#define iterator__honor_ignores(I)     iterator__flag(I,HONOR_IGNORES)
+#define iterator__ignore_dot_git(I)    iterator__flag(I,IGNORE_DOT_GIT)
+#define iterator__descend_symlinks(I)  iterator__flag(I,DESCEND_SYMLINKS)
+
+
+static void iterator_set_ignore_case(git_iterator *iter, bool ignore_case)
+{
+	if (ignore_case)
+		iter->flags |= GIT_ITERATOR_IGNORE_CASE;
+	else
+		iter->flags &= ~GIT_ITERATOR_IGNORE_CASE;
+
+	iter->strcomp = ignore_case ? git__strcasecmp : git__strcmp;
+	iter->strncomp = ignore_case ? git__strncasecmp : git__strncmp;
+	iter->prefixcomp = ignore_case ? git__prefixcmp_icase : git__prefixcmp;
+	iter->entry_srch = ignore_case ? git_index_entry_isrch : git_index_entry_srch;
+
+	git_vector_set_cmp(&iter->pathlist, (git_vector_cmp)iter->strcomp);
+}
+
+static int iterator_range_init(
+	git_iterator *iter, const char *start, const char *end)
+{
+	if (start && *start) {
+		iter->start = git__strdup(start);
+		GITERR_CHECK_ALLOC(iter->start);
+
+		iter->start_len = strlen(iter->start);
+	}
+
+	if (end && *end) {
+		iter->end = git__strdup(end);
+		GITERR_CHECK_ALLOC(iter->end);
+
+		iter->end_len = strlen(iter->end);
+	}
+
+	iter->started = (iter->start == NULL);
+	iter->ended = false;
+
+	return 0;
+}
+
+static void iterator_range_free(git_iterator *iter)
+{
+	if (iter->start) {
+		git__free(iter->start);
+		iter->start = NULL;
+		iter->start_len = 0;
+	}
+
+	if (iter->end) {
+		git__free(iter->end);
+		iter->end = NULL;
+		iter->end_len = 0;
+	}
+}
+
+static int iterator_reset_range(
+	git_iterator *iter, const char *start, const char *end)
+{
+	iterator_range_free(iter);
+	return iterator_range_init(iter, start, end);
+}
+
+static int iterator_pathlist_init(git_iterator *iter, git_strarray *pathlist)
+{
+	size_t i;
+
+	if (git_vector_init(&iter->pathlist, pathlist->count, NULL) < 0)
+		return -1;
+
+	for (i = 0; i < pathlist->count; i++) {
+		if (!pathlist->strings[i])
+			continue;
+
+		if (git_vector_insert(&iter->pathlist, pathlist->strings[i]) < 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+static int iterator_init_common(
+	git_iterator *iter,
+	git_repository *repo,
+	git_index *index,
+	git_iterator_options *given_opts)
+{
+	static git_iterator_options default_opts = GIT_ITERATOR_OPTIONS_INIT;
+	git_iterator_options *options = given_opts ? given_opts : &default_opts;
+	bool ignore_case;
+	int precompose;
+	int error;
+
+	iter->repo = repo;
+	iter->index = index;
+	iter->flags = options->flags;
+
+	if ((iter->flags & GIT_ITERATOR_IGNORE_CASE) != 0) {
+		ignore_case = true;
+	} else if ((iter->flags & GIT_ITERATOR_DONT_IGNORE_CASE) != 0) {
+		ignore_case = false;
+	} else if (repo) {
+		git_index *index;
+
+		if ((error = git_repository_index__weakptr(&index, iter->repo)) < 0)
+			return error;
+
+		ignore_case = !!index->ignore_case;
+
+		if (ignore_case == 1)
+			iter->flags |= GIT_ITERATOR_IGNORE_CASE;
+		else
+			iter->flags |= GIT_ITERATOR_DONT_IGNORE_CASE;
+	} else {
+		ignore_case = false;
+	}
+
+	/* try to look up precompose and set flag if appropriate */
+	if (repo &&
+		(iter->flags & GIT_ITERATOR_PRECOMPOSE_UNICODE) == 0 &&
+		(iter->flags & GIT_ITERATOR_DONT_PRECOMPOSE_UNICODE) == 0) {
+
+		if (git_repository__cvar(&precompose, repo, GIT_CVAR_PRECOMPOSE) < 0)
+			giterr_clear();
+		else if (precompose)
+			iter->flags |= GIT_ITERATOR_PRECOMPOSE_UNICODE;
+	}
+
+	if ((iter->flags & GIT_ITERATOR_DONT_AUTOEXPAND))
+		iter->flags |= GIT_ITERATOR_INCLUDE_TREES;
+
+	if ((error = iterator_range_init(iter, options->start, options->end)) < 0 ||
+		(error = iterator_pathlist_init(iter, &options->pathlist)) < 0)
+		return error;
+
+	iterator_set_ignore_case(iter, ignore_case);
+	return 0;
+}
+
+static void iterator_clear(git_iterator *iter)
+{
+	iter->started = false;
+	iter->ended = false;
+	iter->stat_calls = 0;
+	iter->pathlist_walk_idx = 0;
+	iter->flags &= ~GIT_ITERATOR_FIRST_ACCESS;
+}
+
+GIT_INLINE(bool) iterator_has_started(
+	git_iterator *iter, const char *path, bool is_submodule)
+{
+	size_t path_len;
+
+	if (iter->start == NULL || iter->started == true)
+		return true;
+
+	/* the starting path is generally a prefix - we have started once we
+	 * are prefixed by this path
+	 */
+	iter->started = (iter->prefixcomp(path, iter->start) >= 0);
+
+	if (iter->started)
+		return true;
+
+	path_len = strlen(path);
+
+	/* if, however, we are a submodule, then we support `start` being
+	 * suffixed with a `/` for crazy legacy reasons.  match `submod`
+	 * with a start path of `submod/`.
+	 */
+	if (is_submodule && iter->start_len && path_len == iter->start_len - 1 &&
+		iter->start[iter->start_len-1] == '/')
+		return true;
+
+	/* if, however, our current path is a directory, and our starting path
+	 * is _beneath_ that directory, then recurse into the directory (even
+	 * though we have not yet "started")
+	 */
+	if (path_len > 0 && path[path_len-1] == '/' &&
+		iter->strncomp(path, iter->start, path_len) == 0)
+		return true;
+
+	return false;
+}
+
+GIT_INLINE(bool) iterator_has_ended(git_iterator *iter, const char *path)
+{
+	if (iter->end == NULL)
+		return false;
+	else if (iter->ended)
+		return true;
+
+	iter->ended = (iter->prefixcomp(path, iter->end) > 0);
+	return iter->ended;
+}
+
+/* walker for the index and tree iterator that allows it to walk the sorted
+ * pathlist entries alongside sorted iterator entries.
+ */
+static bool iterator_pathlist_next_is(git_iterator *iter, const char *path)
+{
+	char *p;
+	size_t path_len, p_len, cmp_len, i;
+	int cmp;
+
+	if (iter->pathlist.length == 0)
+		return true;
+
+	git_vector_sort(&iter->pathlist);
+
+	path_len = strlen(path);
+
+	/* for comparison, drop the trailing slash on the current '/' */
+	if (path_len && path[path_len-1] == '/')
+		path_len--;
+
+	for (i = iter->pathlist_walk_idx; i < iter->pathlist.length; i++) {
+		p = iter->pathlist.contents[i];
+		p_len = strlen(p);
+
+		if (p_len && p[p_len-1] == '/')
+			p_len--;
+
+		cmp_len = min(path_len, p_len);
+
+		/* see if the pathlist entry is a prefix of this path */
+		cmp = iter->strncomp(p, path, cmp_len);
+
+		/* prefix match - see if there's an exact match, or if we were
+		 * given a path that matches the directory
+		 */
+		if (cmp == 0) {
+			/* if this pathlist entry is not suffixed with a '/' then
+			 * it matches a path that is a file or a directory.
+			 * (eg, pathlist = "foo" and path is "foo" or "foo/" or
+			 * "foo/something")
+			 */
+			if (p[cmp_len] == '\0' &&
+				(path[cmp_len] == '\0' || path[cmp_len] == '/'))
+				return true;
+
+			/* if this pathlist entry _is_ suffixed with a '/' then
+			 * it matches only paths that are directories.
+			 * (eg, pathlist = "foo/" and path is "foo/" or "foo/something")
+			 */
+			if (p[cmp_len] == '/' && path[cmp_len] == '/')
+				return true;
+		}
+
+		/* this pathlist entry sorts before the given path, try the next */
+		else if (cmp < 0) {
+			iter->pathlist_walk_idx++;
+			continue;
+		}
+
+		/* this pathlist sorts after the given path, no match. */
+		else if (cmp > 0) {
+			break;
+		}
+	}
+
+	return false;
+}
+
+typedef enum {
+	ITERATOR_PATHLIST_NONE = 0,
+	ITERATOR_PATHLIST_IS_FILE = 1,
+	ITERATOR_PATHLIST_IS_DIR = 2,
+	ITERATOR_PATHLIST_IS_PARENT = 3,
+	ITERATOR_PATHLIST_FULL = 4,
+} iterator_pathlist_search_t;
+
+static iterator_pathlist_search_t iterator_pathlist_search(
+	git_iterator *iter, const char *path, size_t path_len)
+{
+	const char *p;
+	size_t idx;
+	int error;
+
+	if (iter->pathlist.length == 0)
+		return ITERATOR_PATHLIST_FULL;
+
+	git_vector_sort(&iter->pathlist);
+
+	error = git_vector_bsearch2(&idx, &iter->pathlist,
+		(git_vector_cmp)iter->strcomp, path);
+
+	/* the given path was found in the pathlist.  since the pathlist only
+	 * matches directories when they're suffixed with a '/', analyze the
+	 * path string to determine whether it's a directory or not.
+	 */
+	if (error == 0) {
+		if (path_len && path[path_len-1] == '/')
+			return ITERATOR_PATHLIST_IS_DIR;
+
+		return ITERATOR_PATHLIST_IS_FILE;
+	}
+
+	/* at this point, the path we're examining may be a directory (though we
+	 * don't know that yet, since we're avoiding a stat unless it's necessary)
+	 * so walk the pathlist looking for the given path with a '/' after it,
+	 */
+	while ((p = git_vector_get(&iter->pathlist, idx)) != NULL) {
+		if (iter->prefixcomp(p, path) != 0)
+			break;
+
+		/* an exact match would have been matched by the bsearch above */
+		assert(p[path_len]);
+
+		/* is this a literal directory entry (eg `foo/`) or a file beneath */
+		if (p[path_len] == '/') {
+			return (p[path_len+1] == '\0') ?
+				ITERATOR_PATHLIST_IS_DIR :
+				ITERATOR_PATHLIST_IS_PARENT;
+		}
+
+		if (p[path_len] > '/')
+			break;
+
+		idx++;
+	}
+
+	return ITERATOR_PATHLIST_NONE;
+}
+
+/* Empty iterator */
+
+static int empty_iterator_noop(const git_index_entry **e, git_iterator *i)
+{
+	GIT_UNUSED(i);
+
+	if (e)
+		*e = NULL;
+
+	return GIT_ITEROVER;
+}
+
+static int empty_iterator_advance_over(
+	const git_index_entry **e,
+	git_iterator_status_t *s,
+	git_iterator *i)
+{
+	*s = GIT_ITERATOR_STATUS_EMPTY;
+	return empty_iterator_noop(e, i);
+}
+
+static int empty_iterator_reset(git_iterator *i)
+{
+	GIT_UNUSED(i);
+	return 0;
+}
+
+static void empty_iterator_free(git_iterator *i)
+{
+	GIT_UNUSED(i);
+}
+
+typedef struct {
+	git_iterator base;
+	git_iterator_callbacks cb;
+} empty_iterator;
+
+int git_iterator_for_nothing(
+	git_iterator **out,
+	git_iterator_options *options)
+{
+	empty_iterator *iter;
+
+	static git_iterator_callbacks callbacks = {
+		empty_iterator_noop,
+		empty_iterator_noop,
+		empty_iterator_noop,
+		empty_iterator_advance_over,
+		empty_iterator_reset,
+		empty_iterator_free
+	};
+
+	*out = NULL;
+
+	iter = git__calloc(1, sizeof(empty_iterator));
+	GITERR_CHECK_ALLOC(iter);
+
+	iter->base.type = GIT_ITERATOR_TYPE_EMPTY;
+	iter->base.cb = &callbacks;
+	iter->base.flags = options->flags;
+
+	*out = &iter->base;
+	return 0;
+}
+
+/* Tree iterator */
+
+typedef struct {
+	git_tree_entry *tree_entry;
+	const char *parent_path;
+} tree_iterator_entry;
+
+typedef struct {
+	git_tree *tree;
+
+	/* path to this particular frame (folder) */
+	git_buf path;
+
+	/* a sorted list of the entries for this frame (folder), these are
+	 * actually pointers to the iterator's entry pool.
+	 */
+	git_vector entries;
+	tree_iterator_entry *current;
+
+	size_t next_idx;
+
+	/* on case insensitive iterations, we also have an array of other
+	 * paths that were case insensitively equal to this one, and their
+	 * tree objects.  we have coalesced the tree entries into this frame.
+	 * a child `tree_iterator_entry` will contain a pointer to its actual
+	 * parent path.
+	 */
+	git_vector similar_trees;
+	git_array_t(git_buf) similar_paths;
+} tree_iterator_frame;
+
+typedef struct {
+	git_iterator base;
+	git_tree *root;
+	git_array_t(tree_iterator_frame) frames;
+
+	git_index_entry entry;
+	git_buf entry_path;
+
+	/* a pool of entries to reduce the number of allocations */
+	git_pool entry_pool;
+} tree_iterator;
+
+GIT_INLINE(tree_iterator_frame *) tree_iterator_parent_frame(
+	tree_iterator *iter)
+{
+	return iter->frames.size > 1 ?
+		&iter->frames.ptr[iter->frames.size-2] : NULL;
+}
+
+GIT_INLINE(tree_iterator_frame *) tree_iterator_current_frame(
+	tree_iterator *iter)
+{
+	return iter->frames.size ? &iter->frames.ptr[iter->frames.size-1] : NULL;
+}
+
+GIT_INLINE(int) tree_entry_cmp(
+	const git_tree_entry *a, const git_tree_entry *b, bool icase)
+{
+	return git_path_cmp(
+		a->filename, a->filename_len, a->attr == GIT_FILEMODE_TREE,
+		b->filename, b->filename_len, b->attr == GIT_FILEMODE_TREE,
+		icase ? git__strncasecmp : git__strncmp);
+}
+
+GIT_INLINE(int) tree_iterator_entry_cmp(const void *ptr_a, const void *ptr_b)
+{
+	const tree_iterator_entry *a = (const tree_iterator_entry *)ptr_a;
+	const tree_iterator_entry *b = (const tree_iterator_entry *)ptr_b;
+
+	return tree_entry_cmp(a->tree_entry, b->tree_entry, false);
+}
+
+GIT_INLINE(int) tree_iterator_entry_cmp_icase(
+	const void *ptr_a, const void *ptr_b)
+{
+	const tree_iterator_entry *a = (const tree_iterator_entry *)ptr_a;
+	const tree_iterator_entry *b = (const tree_iterator_entry *)ptr_b;
+
+	return tree_entry_cmp(a->tree_entry, b->tree_entry, true);
+}
+
+static int tree_iterator_entry_sort_icase(const void *ptr_a, const void *ptr_b)
+{
+	const tree_iterator_entry *a = (const tree_iterator_entry *)ptr_a;
+	const tree_iterator_entry *b = (const tree_iterator_entry *)ptr_b;
+
+	int c = tree_entry_cmp(a->tree_entry, b->tree_entry, true);
+
+	/* stabilize the sort order for filenames that are (case insensitively)
+	 * the same by examining the parent path (case sensitively) before
+	 * falling back to a case sensitive sort of the filename.
+	 */
+	if (!c && a->parent_path != b->parent_path)
+		c = git__strcmp(a->parent_path, b->parent_path);
+
+	if (!c)
+		c = tree_entry_cmp(a->tree_entry, b->tree_entry, false);
+
+	return c;
+}
+
+static int tree_iterator_compute_path(
+	git_buf *out,
+	tree_iterator_entry *entry)
+{
+	git_buf_clear(out);
+
+	if (entry->parent_path)
+		git_buf_joinpath(out, entry->parent_path, entry->tree_entry->filename);
+	else
+		git_buf_puts(out, entry->tree_entry->filename);
+
+	if (git_tree_entry__is_tree(entry->tree_entry))
+		git_buf_putc(out, '/');
+
+	if (git_buf_oom(out))
+		return -1;
+
+	return 0;
+}
+
+static int tree_iterator_frame_init(
+	tree_iterator *iter,
+	git_tree *tree,
+	tree_iterator_entry *frame_entry)
+{
+	tree_iterator_frame *new_frame = NULL;
+	tree_iterator_entry *new_entry;
+	git_tree *dup = NULL;
+	git_tree_entry *tree_entry;
+	git_vector_cmp cmp;
+	size_t i;
+	int error = 0;
+
+	new_frame = git_array_alloc(iter->frames);
+	GITERR_CHECK_ALLOC(new_frame);
+
+	memset(new_frame, 0, sizeof(tree_iterator_frame));
+
+	if ((error = git_tree_dup(&dup, tree)) < 0)
+		goto done;
+
+	memset(new_frame, 0x0, sizeof(tree_iterator_frame));
+	new_frame->tree = dup;
+
+	if (frame_entry &&
+		(error = tree_iterator_compute_path(&new_frame->path, frame_entry)) < 0)
+		goto done;
+
+	cmp = iterator__ignore_case(&iter->base) ?
+		tree_iterator_entry_sort_icase : NULL;
+
+	if ((error = git_vector_init(
+		&new_frame->entries, dup->entries.size, cmp)) < 0)
+		goto done;
+
+	git_array_foreach(dup->entries, i, tree_entry) {
+		new_entry = git_pool_malloc(&iter->entry_pool, 1);
+		GITERR_CHECK_ALLOC(new_entry);
+
+		new_entry->tree_entry = tree_entry;
+		new_entry->parent_path = new_frame->path.ptr;
+
+		if ((error = git_vector_insert(&new_frame->entries, new_entry)) < 0)
+			goto done;
+	}
+
+	git_vector_set_sorted(&new_frame->entries,
+		!iterator__ignore_case(&iter->base));
+
+done:
+	if (error < 0) {
+		git_tree_free(dup);
+		git_array_pop(iter->frames);
+	}
+
+	return error;
+}
+
+GIT_INLINE(tree_iterator_entry *) tree_iterator_current_entry(
+	tree_iterator_frame *frame)
+{
+	return frame->current;
+}
+
+GIT_INLINE(int) tree_iterator_frame_push_neighbors(
+	tree_iterator *iter,
+	tree_iterator_frame *parent_frame,
+	tree_iterator_frame *frame,
+	const char *filename)
+{
+	tree_iterator_entry *entry, *new_entry;
+	git_tree *tree = NULL;
+	git_tree_entry *tree_entry;
+	git_buf *path;
+	size_t new_size, i;
+	int error = 0;
+
+	while (parent_frame->next_idx < parent_frame->entries.length) {
+		entry = parent_frame->entries.contents[parent_frame->next_idx];
+
+		if (strcasecmp(filename, entry->tree_entry->filename) != 0)
+			break;
+
+		if ((error = git_tree_lookup(&tree,
+			iter->base.repo, entry->tree_entry->oid)) < 0)
+			break;
+
+		if (git_vector_insert(&parent_frame->similar_trees, tree) < 0)
+			break;
+
+		path = git_array_alloc(parent_frame->similar_paths);
+		GITERR_CHECK_ALLOC(path);
+
+		memset(path, 0, sizeof(git_buf));
+
+		if ((error = tree_iterator_compute_path(path, entry)) < 0)
+			break;
+
+		GITERR_CHECK_ALLOC_ADD(&new_size,
+			frame->entries.length, tree->entries.size);
+		git_vector_size_hint(&frame->entries, new_size);
+
+		git_array_foreach(tree->entries, i, tree_entry) {
+			new_entry = git_pool_malloc(&iter->entry_pool, 1);
+			GITERR_CHECK_ALLOC(new_entry);
+
+			new_entry->tree_entry = tree_entry;
+			new_entry->parent_path = path->ptr;
+
+			if ((error = git_vector_insert(&frame->entries, new_entry)) < 0)
+				break;
+		}
+
+		if (error)
+			break;
+
+		parent_frame->next_idx++;
+	}
+
+	return error;
+}
+
+GIT_INLINE(int) tree_iterator_frame_push(
+	tree_iterator *iter, tree_iterator_entry *entry)
+{
+	tree_iterator_frame *parent_frame, *frame;
+	git_tree *tree = NULL;
+	int error;
+
+	if ((error = git_tree_lookup(&tree,
+			iter->base.repo, entry->tree_entry->oid)) < 0 ||
+		(error = tree_iterator_frame_init(iter, tree, entry)) < 0)
+		goto done;
+
+	parent_frame = tree_iterator_parent_frame(iter);
+	frame = tree_iterator_current_frame(iter);
+
+	/* if we're case insensitive, then we may have another directory that
+	 * is (case insensitively) equal to this one.  coalesce those children
+	 * into this tree.
+	 */
+	if (iterator__ignore_case(&iter->base))
+		error = tree_iterator_frame_push_neighbors(iter,
+			parent_frame, frame, entry->tree_entry->filename);
+
+done:
+	git_tree_free(tree);
+	return error;
+}
+
+static void tree_iterator_frame_pop(tree_iterator *iter)
+{
+	tree_iterator_frame *frame;
+	git_buf *buf = NULL;
+	git_tree *tree;
+	size_t i;
+
+	assert(iter->frames.size);
+
+	frame = git_array_pop(iter->frames);
+
+	git_vector_free(&frame->entries);
+	git_tree_free(frame->tree);
+
+	do {
+		buf = git_array_pop(frame->similar_paths);
+		git_buf_free(buf);
+	} while (buf != NULL);
+
+	git_array_clear(frame->similar_paths);
+
+	git_vector_foreach(&frame->similar_trees, i, tree)
+		git_tree_free(tree);
+
+	git_vector_free(&frame->similar_trees);
+
+	git_buf_free(&frame->path);
+}
+
+static int tree_iterator_current(
+	const git_index_entry **out, git_iterator *i)
+{
+	tree_iterator *iter = (tree_iterator *)i;
+
+	if (!iterator__has_been_accessed(i))
+		return iter->base.cb->advance(out, i);
+
+	if (!iter->frames.size) {
+		*out = NULL;
+		return GIT_ITEROVER;
+	}
+
+	*out = &iter->entry;
+	return 0;
+}
+
+static void tree_iterator_set_current(
+	tree_iterator *iter,
+	tree_iterator_frame *frame,
+	tree_iterator_entry *entry)
+{
+	git_tree_entry *tree_entry = entry->tree_entry;
+
+	frame->current = entry;
+
+	memset(&iter->entry, 0x0, sizeof(git_index_entry));
+
+	iter->entry.mode = tree_entry->attr;
+	iter->entry.path = iter->entry_path.ptr;
+	git_oid_cpy(&iter->entry.id, tree_entry->oid);
+}
+
+static int tree_iterator_advance(const git_index_entry **out, git_iterator *i)
+{
+	tree_iterator *iter = (tree_iterator *)i;
+	int error = 0;
+
+	iter->base.flags |= GIT_ITERATOR_FIRST_ACCESS;
+
+	/* examine tree entries until we find the next one to return */
+	while (true) {
+		tree_iterator_entry *prev_entry, *entry;
+		tree_iterator_frame *frame;
+		bool is_tree;
+
+		if ((frame = tree_iterator_current_frame(iter)) == NULL) {
+			error = GIT_ITEROVER;
+			break;
+		}
+
+		/* no more entries in this frame.  pop the frame out */
+		if (frame->next_idx == frame->entries.length) {
+			tree_iterator_frame_pop(iter);
+			continue;
+		}
+
+		/* we may have coalesced the contents of case-insensitively same-named
+		 * directories, so do the sort now.
+		 */
+		if (frame->next_idx == 0 && !git_vector_is_sorted(&frame->entries))
+			git_vector_sort(&frame->entries);
+
+		/* we have more entries in the current frame, that's our next entry */
+		prev_entry = tree_iterator_current_entry(frame);
+		entry = frame->entries.contents[frame->next_idx];
+		frame->next_idx++;
+
+		/* we can have collisions when iterating case insensitively.  (eg,
+		 * 'A/a' and 'a/A').  squash this one if it's already been seen.
+		 */
+		if (iterator__ignore_case(&iter->base) &&
+			prev_entry &&
+			tree_iterator_entry_cmp_icase(prev_entry, entry) == 0)
+			continue;
+
+		if ((error = tree_iterator_compute_path(&iter->entry_path, entry)) < 0)
+			break;
+
+		/* if this path is before our start, advance over this entry */
+		if (!iterator_has_started(&iter->base, iter->entry_path.ptr, false))
+			continue;
+
+		/* if this path is after our end, stop */
+		if (iterator_has_ended(&iter->base, iter->entry_path.ptr)) {
+			error = GIT_ITEROVER;
+			break;
+		}
+
+		/* if we have a list of paths we're interested in, examine it */
+		if (!iterator_pathlist_next_is(&iter->base, iter->entry_path.ptr))
+			continue;
+
+		is_tree = git_tree_entry__is_tree(entry->tree_entry);
+
+		/* if we are *not* including trees then advance over this entry */
+		if (is_tree && !iterator__include_trees(iter)) {
+
+			/* if we've found a tree (and are not returning it to the caller)
+			 * and we are autoexpanding, then we want to return the first
+			 * child.  push the new directory and advance.
+			 */
+			if (iterator__do_autoexpand(iter)) {
+				if ((error = tree_iterator_frame_push(iter, entry)) < 0)
+					break;
+			}
+
+			continue;
+		}
+
+		tree_iterator_set_current(iter, frame, entry);
+
+		/* if we are autoexpanding, then push this as a new frame, so that
+		 * the next call to `advance` will dive into this directory.
+		 */
+		if (is_tree && iterator__do_autoexpand(iter))
+			error = tree_iterator_frame_push(iter, entry);
+
+		break;
+	}
+
+	if (out)
+		*out = (error == 0) ? &iter->entry : NULL;
+
+	return error;
+}
+
+static int tree_iterator_advance_into(
+	const git_index_entry **out, git_iterator *i)
+{
+	tree_iterator *iter = (tree_iterator *)i;
+    tree_iterator_frame *frame;
+	tree_iterator_entry *prev_entry;
+	int error;
+
+	if (out)
+		*out = NULL;
+
+	if ((frame = tree_iterator_current_frame(iter)) == NULL)
+		return GIT_ITEROVER;
+
+	/* get the last seen entry */
+	prev_entry = tree_iterator_current_entry(frame);
+
+	/* it's legal to call advance_into when auto-expand is on.  in this case,
+	 * we will have pushed a new (empty) frame on to the stack for this
+	 * new directory.  since it's empty, its current_entry should be null.
+	 */
+	assert(iterator__do_autoexpand(i) ^ (prev_entry != NULL));
+
+	if (prev_entry) {
+		if (!git_tree_entry__is_tree(prev_entry->tree_entry))
+			return 0;
+
+		if ((error = tree_iterator_frame_push(iter, prev_entry)) < 0)
+			return error;
+	}
+
+	/* we've advanced into the directory in question, let advance
+	 * find the first entry
+	 */
+	return tree_iterator_advance(out, i);
+}
+
+static int tree_iterator_advance_over(
+	const git_index_entry **out,
+	git_iterator_status_t *status,
+	git_iterator *i)
+{
+	*status = GIT_ITERATOR_STATUS_NORMAL;
+	return git_iterator_advance(out, i);
+}
+
+static void tree_iterator_clear(tree_iterator *iter)
+{
+	while (iter->frames.size)
+		tree_iterator_frame_pop(iter);
+
+	git_array_clear(iter->frames);
+
+	git_pool_clear(&iter->entry_pool);
+	git_buf_clear(&iter->entry_path);
+
+	iterator_clear(&iter->base);
+}
+
+static int tree_iterator_init(tree_iterator *iter)
+{
+	int error;
+
+	git_pool_init(&iter->entry_pool, sizeof(tree_iterator_entry));
+
+	if ((error = tree_iterator_frame_init(iter, iter->root, NULL)) < 0)
+		return error;
+
+	iter->base.flags &= ~GIT_ITERATOR_FIRST_ACCESS;
+
+	return 0;
+}
+
+static int tree_iterator_reset(git_iterator *i)
+{
+	tree_iterator *iter = (tree_iterator *)i;
+
+	tree_iterator_clear(iter);
+	return tree_iterator_init(iter);
+}
+
+static void tree_iterator_free(git_iterator *i)
+{
+	tree_iterator *iter = (tree_iterator *)i;
+
+	tree_iterator_clear(iter);
+
+	git_tree_free(iter->root);
+	git_buf_free(&iter->entry_path);
+}
+
+int git_iterator_for_tree(
+	git_iterator **out,
+	git_tree *tree,
+	git_iterator_options *options)
+{
+	tree_iterator *iter;
+	int error;
+
+	static git_iterator_callbacks callbacks = {
+		tree_iterator_current,
+		tree_iterator_advance,
+		tree_iterator_advance_into,
+		tree_iterator_advance_over,
+		tree_iterator_reset,
+		tree_iterator_free
+	};
+
+	*out = NULL;
+
+	if (tree == NULL)
+		return git_iterator_for_nothing(out, options);
+
+	iter = git__calloc(1, sizeof(tree_iterator));
+	GITERR_CHECK_ALLOC(iter);
+
+	iter->base.type = GIT_ITERATOR_TYPE_TREE;
+	iter->base.cb = &callbacks;
+
+	if ((error = iterator_init_common(&iter->base,
+			git_tree_owner(tree), NULL, options)) < 0 ||
+		(error = git_tree_dup(&iter->root, tree)) < 0 ||
+		(error = tree_iterator_init(iter)) < 0)
+		goto on_error;
+
+	*out = &iter->base;
+	return 0;
+
+on_error:
+	git_iterator_free(&iter->base);
+	return error;
+}
+
+int git_iterator_current_tree_entry(
+	const git_tree_entry **tree_entry, git_iterator *i)
+{
+	tree_iterator *iter;
+	tree_iterator_frame *frame;
+	tree_iterator_entry *entry;
+
+	assert(i->type == GIT_ITERATOR_TYPE_TREE);
+
+	iter = (tree_iterator *)i;
+
+	frame = tree_iterator_current_frame(iter);
+	entry = tree_iterator_current_entry(frame);
+
+	*tree_entry = entry->tree_entry;
+	return 0;
+}
+
+int git_iterator_current_parent_tree(
+	const git_tree **parent_tree, git_iterator *i, size_t depth)
+{
+	tree_iterator *iter;
+	tree_iterator_frame *frame;
+
+	assert(i->type == GIT_ITERATOR_TYPE_TREE);
+
+	iter = (tree_iterator *)i;
+
+	assert(depth < iter->frames.size);
+	frame = &iter->frames.ptr[iter->frames.size-depth-1];
+
+	*parent_tree = frame->tree;
+	return 0;
+}
+
+/* Filesystem iterator */
+
+typedef struct {
+	struct stat st;
+	size_t path_len;
+	iterator_pathlist_search_t match;
+	char path[GIT_FLEX_ARRAY];
+} filesystem_iterator_entry;
+
+typedef struct {
+	git_vector entries;
+	git_pool entry_pool;
+	size_t next_idx;
+
+	size_t path_len;
+	int is_ignored;
+} filesystem_iterator_frame;
+
+typedef struct {
+	git_iterator base;
+	char *root;
+	size_t root_len;
+
+	unsigned int dirload_flags;
+
+	git_tree *tree;
+	git_index *index;
+	git_vector index_snapshot;
+
+	git_array_t(filesystem_iterator_frame) frames;
+	git_ignores ignores;
+
+	/* info about the current entry */
+	git_index_entry entry;
+	git_buf current_path;
+	int current_is_ignored;
+
+	/* temporary buffer for advance_over */
+	git_buf tmp_buf;
+} filesystem_iterator;
+
+
+GIT_INLINE(filesystem_iterator_frame *) filesystem_iterator_parent_frame(
+	filesystem_iterator *iter)
+{
+	return iter->frames.size > 1 ?
+		&iter->frames.ptr[iter->frames.size-2] : NULL;
+}
+
+GIT_INLINE(filesystem_iterator_frame *) filesystem_iterator_current_frame(
+	filesystem_iterator *iter)
+{
+	return iter->frames.size ? &iter->frames.ptr[iter->frames.size-1] : NULL;
+}
+
+GIT_INLINE(filesystem_iterator_entry *) filesystem_iterator_current_entry(
+	filesystem_iterator_frame *frame)
+{
+	return frame->next_idx == 0 ?
+		NULL : frame->entries.contents[frame->next_idx-1];
+}
+
+static int filesystem_iterator_entry_cmp(const void *_a, const void *_b)
+{
+	const filesystem_iterator_entry *a = (const filesystem_iterator_entry *)_a;
+	const filesystem_iterator_entry *b = (const filesystem_iterator_entry *)_b;
+
+	return git__strcmp(a->path, b->path);
+}
+
+static int filesystem_iterator_entry_cmp_icase(const void *_a, const void *_b)
+{
+	const filesystem_iterator_entry *a = (const filesystem_iterator_entry *)_a;
+	const filesystem_iterator_entry *b = (const filesystem_iterator_entry *)_b;
+
+	return git__strcasecmp(a->path, b->path);
+}
+
+#define FILESYSTEM_MAX_DEPTH 100
+
+/**
+ * Figure out if an entry is a submodule.
+ *
+ * We consider it a submodule if the path is listed as a submodule in
+ * either the tree or the index.
+ */
+static int filesystem_iterator_is_submodule(
+	bool *out, filesystem_iterator *iter, const char *path, size_t path_len)
+{
+	bool is_submodule = false;
+	int error;
+
+	*out = false;
+
+	/* first see if this path is a submodule in HEAD */
+	if (iter->tree) {
+		git_tree_entry *entry;
+
+		error = git_tree_entry_bypath(&entry, iter->tree, path);
+
+		if (error < 0 && error != GIT_ENOTFOUND)
+			return error;
+
+		if (!error) {
+			is_submodule = (entry->attr == GIT_FILEMODE_COMMIT);
+			git_tree_entry_free(entry);
+		}
+	}
+
+	if (!is_submodule && iter->base.index) {
+		size_t pos;
+
+		error = git_index_snapshot_find(&pos,
+			&iter->index_snapshot, iter->base.entry_srch, path, path_len, 0);
+
+		if (error < 0 && error != GIT_ENOTFOUND)
+			return error;
+
+		if (!error) {
+			git_index_entry *e = git_vector_get(&iter->index_snapshot, pos);
+			is_submodule = (e->mode == GIT_FILEMODE_COMMIT);
+		}
+	}
+
+	*out = is_submodule;
+	return 0;
+}
+
+static void filesystem_iterator_frame_push_ignores(
+	filesystem_iterator *iter,
+	filesystem_iterator_entry *frame_entry,
+	filesystem_iterator_frame *new_frame)
+{
+	filesystem_iterator_frame *previous_frame;
+	const char *path = frame_entry ? frame_entry->path : "";
+
+	if (!iterator__honor_ignores(&iter->base))
+		return;
+
+	if (git_ignore__lookup(&new_frame->is_ignored,
+			&iter->ignores, path, GIT_DIR_FLAG_TRUE) < 0) {
+		giterr_clear();
+		new_frame->is_ignored = GIT_IGNORE_NOTFOUND;
+	}
+
+	/* if this is not the top level directory... */
+	if (frame_entry) {
+		const char *relative_path;
+
+		previous_frame = filesystem_iterator_parent_frame(iter);
+
+		/* push new ignores for files in this directory */
+		relative_path = frame_entry->path + previous_frame->path_len;
+
+		/* inherit ignored from parent if no rule specified */
+		if (new_frame->is_ignored <= GIT_IGNORE_NOTFOUND)
+			new_frame->is_ignored = previous_frame->is_ignored;
+
+		git_ignore__push_dir(&iter->ignores, relative_path);
+	}
+}
+
+static void filesystem_iterator_frame_pop_ignores(
+	filesystem_iterator *iter)
+{
+	if (iterator__honor_ignores(&iter->base))
+		git_ignore__pop_dir(&iter->ignores);
+}
+
+GIT_INLINE(bool) filesystem_iterator_examine_path(
+	bool *is_dir_out,
+	iterator_pathlist_search_t *match_out,
+	filesystem_iterator *iter,
+	filesystem_iterator_entry *frame_entry,
+	const char *path,
+	size_t path_len)
+{
+	bool is_dir = 0;
+	iterator_pathlist_search_t match = ITERATOR_PATHLIST_FULL;
+
+	*is_dir_out = false;
+	*match_out = ITERATOR_PATHLIST_NONE;
+
+	if (iter->base.start_len) {
+		int cmp = iter->base.strncomp(path, iter->base.start, path_len);
+
+		/* we haven't stat'ed `path` yet, so we don't yet know if it's a
+		 * directory or not.  special case if the current path may be a
+		 * directory that matches the start prefix.
+		 */
+		if (cmp == 0) {
+			if (iter->base.start[path_len] == '/')
+				is_dir = true;
+
+			else if (iter->base.start[path_len] != '\0')
+				cmp = -1;
+		}
+
+		if (cmp < 0)
+			return false;
+	}
+
+	if (iter->base.end_len) {
+		int cmp = iter->base.strncomp(path, iter->base.end, iter->base.end_len);
+
+		if (cmp > 0)
+			return false;
+	}
+
+	/* if we have a pathlist that we're limiting to, examine this path now
+	 * to avoid a `stat` if we're not interested in the path.
+	 */
+	if (iter->base.pathlist.length) {
+		/* if our parent was explicitly included, so too are we */
+		if (frame_entry && frame_entry->match != ITERATOR_PATHLIST_IS_PARENT)
+			match = ITERATOR_PATHLIST_FULL;
+		else
+			match = iterator_pathlist_search(&iter->base, path, path_len);
+
+		if (match == ITERATOR_PATHLIST_NONE)
+			return false;
+
+		/* Ensure that the pathlist entry lines up with what we expected */
+		if (match == ITERATOR_PATHLIST_IS_DIR ||
+			match == ITERATOR_PATHLIST_IS_PARENT)
+			is_dir = true;
+	}
+
+	*is_dir_out = is_dir;
+	*match_out = match;
+	return true;
+}
+
+GIT_INLINE(bool) filesystem_iterator_is_dot_git(
+	filesystem_iterator *iter, const char *path, size_t path_len)
+{
+	size_t len;
+
+	if (!iterator__ignore_dot_git(&iter->base))
+		return false;
+
+	if ((len = path_len) < 4)
+		return false;
+
+	if (path[len - 1] == '/')
+		len--;
+
+	if (git__tolower(path[len - 1]) != 't' ||
+		git__tolower(path[len - 2]) != 'i' ||
+		git__tolower(path[len - 3]) != 'g' ||
+		git__tolower(path[len - 4]) != '.')
+		return false;
+
+	return (len == 4 || path[len - 5] == '/');
+}
+
+static filesystem_iterator_entry *filesystem_iterator_entry_init(
+	filesystem_iterator_frame *frame,
+	const char *path,
+	size_t path_len,
+	struct stat *statbuf,
+	iterator_pathlist_search_t pathlist_match)
+{
+	filesystem_iterator_entry *entry;
+	size_t entry_size;
+
+	/* Make sure to append two bytes, one for the path's null
+	 * termination, one for a possible trailing '/' for folders.
+	 */
+	if (GIT_ADD_SIZET_OVERFLOW(&entry_size,
+			sizeof(filesystem_iterator_entry), path_len) ||
+		GIT_ADD_SIZET_OVERFLOW(&entry_size, entry_size, 2) ||
+		(entry = git_pool_malloc(&frame->entry_pool, entry_size)) == NULL)
+		return NULL;
+
+	entry->path_len = path_len;
+	entry->match = pathlist_match;
+	memcpy(entry->path, path, path_len);
+	memcpy(&entry->st, statbuf, sizeof(struct stat));
+
+	/* Suffix directory paths with a '/' */
+	if (S_ISDIR(entry->st.st_mode))
+		entry->path[entry->path_len++] = '/';
+
+	entry->path[entry->path_len] = '\0';
+
+	return entry;
+}
+
+static int filesystem_iterator_frame_push(
+	filesystem_iterator *iter,
+	filesystem_iterator_entry *frame_entry)
+{
+	filesystem_iterator_frame *new_frame = NULL;
+	git_path_diriter diriter = GIT_PATH_DIRITER_INIT;
+	git_buf root = GIT_BUF_INIT;
+	const char *path;
+	filesystem_iterator_entry *entry;
+	struct stat statbuf;
+	size_t path_len;
+	int error;
+
+	if (iter->frames.size == FILESYSTEM_MAX_DEPTH) {
+		giterr_set(GITERR_REPOSITORY,
+			"directory nesting too deep (%"PRIuZ")", iter->frames.size);
+		return -1;
+	}
+
+	new_frame = git_array_alloc(iter->frames);
+	GITERR_CHECK_ALLOC(new_frame);
+
+	memset(new_frame, 0, sizeof(filesystem_iterator_frame));
+
+	if (frame_entry)
+		git_buf_joinpath(&root, iter->root, frame_entry->path);
+	else
+		git_buf_puts(&root, iter->root);
+
+	if (git_buf_oom(&root)) {
+		error = -1;
+		goto done;
+	}
+
+	new_frame->path_len = frame_entry ? frame_entry->path_len : 0;
+
+	/* Any error here is equivalent to the dir not existing, skip over it */
+	if ((error = git_path_diriter_init(
+			&diriter, root.ptr, iter->dirload_flags)) < 0) {
+		error = GIT_ENOTFOUND;
+		goto done;
+	}
+
+	if ((error = git_vector_init(&new_frame->entries, 64,
+			iterator__ignore_case(&iter->base) ?
+			filesystem_iterator_entry_cmp_icase :
+			filesystem_iterator_entry_cmp)) < 0)
+		goto done;
+
+	git_pool_init(&new_frame->entry_pool, 1);
+
+	/* check if this directory is ignored */
+	filesystem_iterator_frame_push_ignores(iter, frame_entry, new_frame);
+
+	while ((error = git_path_diriter_next(&diriter)) == 0) {
+		iterator_pathlist_search_t pathlist_match = ITERATOR_PATHLIST_FULL;
+		bool dir_expected = false;
+
+		if ((error = git_path_diriter_fullpath(&path, &path_len, &diriter)) < 0)
+			goto done;
+
+		assert(path_len > iter->root_len);
+
+		/* remove the prefix if requested */
+		path += iter->root_len;
+		path_len -= iter->root_len;
+
+		/* examine start / end and the pathlist to see if this path is in it.
+		 * note that since we haven't yet stat'ed the path, we cannot know
+		 * whether it's a directory yet or not, so this can give us an
+		 * expected type (S_IFDIR or S_IFREG) that we should examine)
+		 */
+		if (!filesystem_iterator_examine_path(&dir_expected, &pathlist_match,
+			iter, frame_entry, path, path_len))
+			continue;
+
+		/* TODO: don't need to stat if assume unchanged for this path and
+		 * we have an index, we can just copy the data out of it.
+		 */
+
+		if ((error = git_path_diriter_stat(&statbuf, &diriter)) < 0) {
+			/* file was removed between readdir and lstat */
+			if (error == GIT_ENOTFOUND)
+				continue;
+
+			/* treat the file as unreadable */
+			memset(&statbuf, 0, sizeof(statbuf));
+			statbuf.st_mode = GIT_FILEMODE_UNREADABLE;
+
+			error = 0;
+		}
+
+		iter->base.stat_calls++;
+
+		/* Ignore wacky things in the filesystem */
+		if (!S_ISDIR(statbuf.st_mode) &&
+			!S_ISREG(statbuf.st_mode) &&
+			!S_ISLNK(statbuf.st_mode) &&
+			statbuf.st_mode != GIT_FILEMODE_UNREADABLE)
+			continue;
+
+		if (filesystem_iterator_is_dot_git(iter, path, path_len))
+			continue;
+
+		/* convert submodules to GITLINK and remove trailing slashes */
+		if (S_ISDIR(statbuf.st_mode)) {
+			bool submodule = false;
+
+			if ((error = filesystem_iterator_is_submodule(&submodule,
+					iter, path, path_len)) < 0)
+				goto done;
+
+			if (submodule)
+				statbuf.st_mode = GIT_FILEMODE_COMMIT;
+		}
+
+		/* Ensure that the pathlist entry lines up with what we expected */
+		else if (dir_expected)
+			continue;
+
+		entry = filesystem_iterator_entry_init(new_frame,
+			path, path_len, &statbuf, pathlist_match);
+		GITERR_CHECK_ALLOC(entry);
+
+		git_vector_insert(&new_frame->entries, entry);
+	}
+
+	if (error == GIT_ITEROVER)
+		error = 0;
+
+	/* sort now that directory suffix is added */
+	git_vector_sort(&new_frame->entries);
+
+done:
+	if (error < 0)
+		git_array_pop(iter->frames);
+
+	git_buf_free(&root);
+	git_path_diriter_free(&diriter);
+	return error;
+}
+
+GIT_INLINE(void) filesystem_iterator_frame_pop(filesystem_iterator *iter)
+{
+	filesystem_iterator_frame *frame;
+
+	assert(iter->frames.size);
+
+	frame = git_array_pop(iter->frames);
+	filesystem_iterator_frame_pop_ignores(iter);
+
+	git_pool_clear(&frame->entry_pool);
+	git_vector_free(&frame->entries);
+}
+
+static void filesystem_iterator_set_current(
+	filesystem_iterator *iter,
+	filesystem_iterator_entry *entry)
+{
+	iter->entry.ctime.seconds = entry->st.st_ctime;
+	iter->entry.mtime.seconds = entry->st.st_mtime;
+
+#if defined(GIT_USE_NSEC)	
+	iter->entry.ctime.nanoseconds = entry->st.st_ctime_nsec;
+	iter->entry.mtime.nanoseconds = entry->st.st_mtime_nsec;
+#else
+	iter->entry.ctime.nanoseconds = 0;
+	iter->entry.mtime.nanoseconds = 0;
+#endif
+
+	iter->entry.dev = entry->st.st_dev;
+	iter->entry.ino = entry->st.st_ino;
+	iter->entry.mode = git_futils_canonical_mode(entry->st.st_mode);
+	iter->entry.uid = entry->st.st_uid;
+	iter->entry.gid = entry->st.st_gid;
+	iter->entry.file_size = entry->st.st_size;
+
+	iter->entry.path = entry->path;
+
+	iter->current_is_ignored = GIT_IGNORE_UNCHECKED;
+}
+
+static int filesystem_iterator_current(
+	const git_index_entry **out, git_iterator *i)
+{
+	filesystem_iterator *iter = (filesystem_iterator *)i;
+
+	if (!iterator__has_been_accessed(i))
+		return iter->base.cb->advance(out, i);
+
+	if (!iter->frames.size) {
+		*out = NULL;
+		return GIT_ITEROVER;
+	}
+
+	*out = &iter->entry;
+	return 0;
+}
+
+static int filesystem_iterator_is_dir(
+	bool *is_dir,
+	const filesystem_iterator *iter,
+	const filesystem_iterator_entry *entry)
+{
+	struct stat st;
+	git_buf fullpath = GIT_BUF_INIT;
+	int error = 0;
+
+	if (S_ISDIR(entry->st.st_mode)) {
+		*is_dir = 1;
+		goto done;
+	}
+
+	if (!iterator__descend_symlinks(iter) || !S_ISLNK(entry->st.st_mode)) {
+		*is_dir = 0;
+		goto done;
+	}
+
+	if ((error = git_buf_joinpath(&fullpath, iter->root, entry->path)) < 0 ||
+		(error = p_stat(fullpath.ptr, &st)) < 0)
+		goto done;
+
+	*is_dir = S_ISDIR(st.st_mode);
+
+done:
+	git_buf_free(&fullpath);
+	return error;
+}
+
+static int filesystem_iterator_advance(
+	const git_index_entry **out, git_iterator *i)
+{
+	filesystem_iterator *iter = (filesystem_iterator *)i;
+	bool is_dir;
+	int error = 0;
+
+	iter->base.flags |= GIT_ITERATOR_FIRST_ACCESS;
+
+	/* examine filesystem entries until we find the next one to return */
+	while (true) {
+		filesystem_iterator_frame *frame;
+		filesystem_iterator_entry *entry;
+
+		if ((frame = filesystem_iterator_current_frame(iter)) == NULL) {
+			error = GIT_ITEROVER;
+			break;
+		}
+
+		/* no more entries in this frame.  pop the frame out */
+		if (frame->next_idx == frame->entries.length) {
+			filesystem_iterator_frame_pop(iter);
+			continue;
+		}
+
+		/* we have more entries in the current frame, that's our next entry */
+		entry = frame->entries.contents[frame->next_idx];
+		frame->next_idx++;
+
+		if ((error = filesystem_iterator_is_dir(&is_dir, iter, entry)) < 0)
+			break;
+
+		if (is_dir) {
+			if (iterator__do_autoexpand(iter)) {
+				error = filesystem_iterator_frame_push(iter, entry);
+
+				/* may get GIT_ENOTFOUND due to races or permission problems
+				 * that we want to quietly swallow
+				 */
+				if (error == GIT_ENOTFOUND)
+					continue;
+				else if (error < 0)
+					break;
+			}
+
+			if (!iterator__include_trees(iter))
+				continue;
+		}
+
+		filesystem_iterator_set_current(iter, entry);
+		break;
+	}
+
+	if (out)
+		*out = (error == 0) ? &iter->entry : NULL;
+
+	return error;
+}
+
+static int filesystem_iterator_advance_into(
+	const git_index_entry **out, git_iterator *i)
+{
+	filesystem_iterator *iter = (filesystem_iterator *)i;
+	filesystem_iterator_frame *frame;
+	filesystem_iterator_entry *prev_entry;
+	int error;
+
+	if (out)
+		*out = NULL;
+
+	if ((frame = filesystem_iterator_current_frame(iter)) == NULL)
+		return GIT_ITEROVER;
+
+	/* get the last seen entry */
+	prev_entry = filesystem_iterator_current_entry(frame);
+
+	/* it's legal to call advance_into when auto-expand is on.  in this case,
+	 * we will have pushed a new (empty) frame on to the stack for this
+	 * new directory.  since it's empty, its current_entry should be null.
+	 */
+	assert(iterator__do_autoexpand(i) ^ (prev_entry != NULL));
+
+	if (prev_entry) {
+		if (prev_entry->st.st_mode != GIT_FILEMODE_COMMIT &&
+			!S_ISDIR(prev_entry->st.st_mode))
+			return 0;
+
+		if ((error = filesystem_iterator_frame_push(iter, prev_entry)) < 0)
+			return error;
+	}
+
+	/* we've advanced into the directory in question, let advance
+	 * find the first entry
+	 */
+	return filesystem_iterator_advance(out, i);
+}
+
+int git_iterator_current_workdir_path(git_buf **out, git_iterator *i)
+{
+	filesystem_iterator *iter = (filesystem_iterator *)i;
+	const git_index_entry *entry;
+
+	if (i->type != GIT_ITERATOR_TYPE_FS &&
+		i->type != GIT_ITERATOR_TYPE_WORKDIR) {
+		*out = NULL;
+		return 0;
+	}
+
+	git_buf_truncate(&iter->current_path, iter->root_len);
+
+	if (git_iterator_current(&entry, i) < 0 ||
+		git_buf_puts(&iter->current_path, entry->path) < 0)
+		return -1;
+
+	*out = &iter->current_path;
+	return 0;
+}
+
+GIT_INLINE(git_dir_flag) entry_dir_flag(git_index_entry *entry)
+{
+#if defined(GIT_WIN32) && !defined(__MINGW32__)
+	return (entry && entry->mode) ?
+		(S_ISDIR(entry->mode) ? GIT_DIR_FLAG_TRUE : GIT_DIR_FLAG_FALSE) :
+		GIT_DIR_FLAG_UNKNOWN;
+#else
+	GIT_UNUSED(entry);
+	return GIT_DIR_FLAG_UNKNOWN;
+#endif
+}
+
+static void filesystem_iterator_update_ignored(filesystem_iterator *iter)
+{
+	filesystem_iterator_frame *frame;
+	git_dir_flag dir_flag = entry_dir_flag(&iter->entry);
+
+	if (git_ignore__lookup(&iter->current_is_ignored,
+			&iter->ignores, iter->entry.path, dir_flag) < 0) {
+		giterr_clear();
+		iter->current_is_ignored = GIT_IGNORE_NOTFOUND;
+	}
+
+	/* use ignore from containing frame stack */
+	if (iter->current_is_ignored <= GIT_IGNORE_NOTFOUND) {
+		frame = filesystem_iterator_current_frame(iter);
+		iter->current_is_ignored = frame->is_ignored;
+	}
+}
+
+GIT_INLINE(bool) filesystem_iterator_current_is_ignored(
+	filesystem_iterator *iter)
+{
+	if (iter->current_is_ignored == GIT_IGNORE_UNCHECKED)
+		filesystem_iterator_update_ignored(iter);
+
+	return (iter->current_is_ignored == GIT_IGNORE_TRUE);
+}
+
+bool git_iterator_current_is_ignored(git_iterator *i)
+{
+	if (i->type != GIT_ITERATOR_TYPE_WORKDIR)
+		return false;
+
+	return filesystem_iterator_current_is_ignored((filesystem_iterator *)i);
+}
+
+bool git_iterator_current_tree_is_ignored(git_iterator *i)
+{
+	filesystem_iterator *iter = (filesystem_iterator *)i;
+	filesystem_iterator_frame *frame;
+
+	if (i->type != GIT_ITERATOR_TYPE_WORKDIR)
+		return false;
+
+	frame = filesystem_iterator_current_frame(iter);
+	return (frame->is_ignored == GIT_IGNORE_TRUE);
+}
+
+static int filesystem_iterator_advance_over(
+	const git_index_entry **out,
+	git_iterator_status_t *status,
+	git_iterator *i)
+{
+	filesystem_iterator *iter = (filesystem_iterator *)i;
+	filesystem_iterator_frame *current_frame;
+	filesystem_iterator_entry *current_entry;
+	const git_index_entry *entry = NULL;
+	const char *base;
+	int error = 0;
+
+	*out = NULL;
+	*status = GIT_ITERATOR_STATUS_NORMAL;
+
+	assert(iterator__has_been_accessed(i));
+
+	current_frame = filesystem_iterator_current_frame(iter);
+	assert(current_frame);
+	current_entry = filesystem_iterator_current_entry(current_frame);
+	assert(current_entry);
+
+	if ((error = git_iterator_current(&entry, i)) < 0)
+		return error;
+
+	if (!S_ISDIR(entry->mode)) {
+		if (filesystem_iterator_current_is_ignored(iter))
+			*status = GIT_ITERATOR_STATUS_IGNORED;
+
+		return filesystem_iterator_advance(out, i);
+	}
+
+	git_buf_clear(&iter->tmp_buf);
+	if ((error = git_buf_puts(&iter->tmp_buf, entry->path)) < 0)
+		return error;
+
+	base = iter->tmp_buf.ptr;
+
+	/* scan inside the directory looking for files.  if we find nothing,
+	 * we will remain EMPTY.  if we find any ignored item, upgrade EMPTY to
+	 * IGNORED.  if we find a real actual item, upgrade all the way to NORMAL
+	 * and then stop.
+	 *
+	 * however, if we're here looking for a pathlist item (but are not
+	 * actually in the pathlist ourselves) then start at FILTERED instead of
+	 * EMPTY.  callers then know that this path was not something they asked
+	 * about.
+	 */
+	*status = current_entry->match == ITERATOR_PATHLIST_IS_PARENT ?
+		GIT_ITERATOR_STATUS_FILTERED : GIT_ITERATOR_STATUS_EMPTY;
+
+	while (entry && !iter->base.prefixcomp(entry->path, base)) {
+		if (filesystem_iterator_current_is_ignored(iter)) {
+			/* if we found an explicitly ignored item, then update from
+			 * EMPTY to IGNORED
+			 */
+			*status = GIT_ITERATOR_STATUS_IGNORED;
+		} else if (S_ISDIR(entry->mode)) {
+			error = filesystem_iterator_advance_into(&entry, i);
+
+			if (!error)
+				continue;
+
+			/* this directory disappeared, ignore it */
+			else if (error == GIT_ENOTFOUND)
+				error = 0;
+
+			/* a real error occurred */
+			else
+				break;
+		} else {
+			/* we found a non-ignored item, treat parent as untracked */
+			*status = GIT_ITERATOR_STATUS_NORMAL;
+			break;
+		}
+
+		if ((error = git_iterator_advance(&entry, i)) < 0)
+			break;
+	}
+
+	/* wrap up scan back to base directory */
+	while (entry && !iter->base.prefixcomp(entry->path, base)) {
+		if ((error = git_iterator_advance(&entry, i)) < 0)
+			break;
+	}
+
+	if (!error)
+		*out = entry;
+
+	return error;
+}
+
+static void filesystem_iterator_clear(filesystem_iterator *iter)
+{
+	while (iter->frames.size)
+		filesystem_iterator_frame_pop(iter);
+
+	git_array_clear(iter->frames);
+	git_ignore__free(&iter->ignores);
+
+	git_buf_free(&iter->tmp_buf);
+
+	iterator_clear(&iter->base);
+}
+
+static int filesystem_iterator_init(filesystem_iterator *iter)
+{
+	int error;
+
+	if (iterator__honor_ignores(&iter->base) &&
+		(error = git_ignore__for_path(iter->base.repo,
+			".gitignore", &iter->ignores)) < 0)
+		return error;
+
+	if ((error = filesystem_iterator_frame_push(iter, NULL)) < 0)
+		return error;
+
+	iter->base.flags &= ~GIT_ITERATOR_FIRST_ACCESS;
+
+	return 0;
+}
+
+static int filesystem_iterator_reset(git_iterator *i)
+{
+	filesystem_iterator *iter = (filesystem_iterator *)i;
+
+	filesystem_iterator_clear(iter);
+	return filesystem_iterator_init(iter);
+}
+
+static void filesystem_iterator_free(git_iterator *i)
+{
+	filesystem_iterator *iter = (filesystem_iterator *)i;
+	git__free(iter->root);
+	git_buf_free(&iter->current_path);
+	git_tree_free(iter->tree);
+	if (iter->index)
+		git_index_snapshot_release(&iter->index_snapshot, iter->index);
+	filesystem_iterator_clear(iter);
+}
+
+static int iterator_for_filesystem(
+	git_iterator **out,
+	git_repository *repo,
+	const char *root,
+	git_index *index,
+	git_tree *tree,
+	git_iterator_type_t type,
+	git_iterator_options *options)
+{
+	filesystem_iterator *iter;
+	size_t root_len;
+	int error;
+
+	static git_iterator_callbacks callbacks = {
+		filesystem_iterator_current,
+		filesystem_iterator_advance,
+		filesystem_iterator_advance_into,
+		filesystem_iterator_advance_over,
+		filesystem_iterator_reset,
+		filesystem_iterator_free
+	};
+
+	*out = NULL;
+
+	if (root == NULL)
+		return git_iterator_for_nothing(out, options);
+
+	iter = git__calloc(1, sizeof(filesystem_iterator));
+	GITERR_CHECK_ALLOC(iter);
+
+	iter->base.type = type;
+	iter->base.cb = &callbacks;
+
+	root_len = strlen(root);
+
+	iter->root = git__malloc(root_len+2);
+	GITERR_CHECK_ALLOC(iter->root);
+
+	memcpy(iter->root, root, root_len);
+
+	if (root_len == 0 || root[root_len-1] != '/') {
+		iter->root[root_len] = '/';
+		root_len++;
+	}
+	iter->root[root_len] = '\0';
+	iter->root_len = root_len;
+
+	if ((error = git_buf_puts(&iter->current_path, iter->root)) < 0)
+		goto on_error;
+
+	if ((error = iterator_init_common(&iter->base, repo, index, options)) < 0)
+		goto on_error;
+
+	if (tree && (error = git_tree_dup(&iter->tree, tree)) < 0)
+		goto on_error;
+
+	if (index &&
+		(error = git_index_snapshot_new(&iter->index_snapshot, index)) < 0)
+		goto on_error;
+
+	iter->index = index;
+	iter->dirload_flags =
+		(iterator__ignore_case(&iter->base) ? GIT_PATH_DIR_IGNORE_CASE : 0) |
+		(iterator__flag(&iter->base, PRECOMPOSE_UNICODE) ?
+			 GIT_PATH_DIR_PRECOMPOSE_UNICODE : 0);
+
+	if ((error = filesystem_iterator_init(iter)) < 0)
+		goto on_error;
+
+	*out = &iter->base;
+	return 0;
+
+on_error:
+	git_iterator_free(&iter->base);
+	return error;
+}
+
+int git_iterator_for_filesystem(
+	git_iterator **out,
+	const char *root,
+	git_iterator_options *options)
+{
+	return iterator_for_filesystem(out,
+		NULL, root, NULL, NULL, GIT_ITERATOR_TYPE_FS, options);
+}
+
+int git_iterator_for_workdir_ext(
+	git_iterator **out,
+	git_repository *repo,
+	const char *repo_workdir,
+	git_index *index,
+	git_tree *tree,
+	git_iterator_options *given_opts)
+{
+	git_iterator_options options = GIT_ITERATOR_OPTIONS_INIT;
+
+	if (!repo_workdir) {
+		if (git_repository__ensure_not_bare(repo, "scan working directory") < 0)
+			return GIT_EBAREREPO;
+
+		repo_workdir = git_repository_workdir(repo);
+	}
+
+	/* upgrade to a workdir iterator, adding necessary internal flags */
+	if (given_opts)
+		memcpy(&options, given_opts, sizeof(git_iterator_options));
+
+	options.flags |= GIT_ITERATOR_HONOR_IGNORES |
+		GIT_ITERATOR_IGNORE_DOT_GIT;
+
+	return iterator_for_filesystem(out,
+		repo, repo_workdir, index, tree, GIT_ITERATOR_TYPE_WORKDIR, &options);
+}
+
+
+/* Index iterator */
+
+
+typedef struct {
+	git_iterator base;
+	git_vector entries;
+	size_t next_idx;
+
+	/* the pseudotree entry */
+	git_index_entry tree_entry;
+	git_buf tree_buf;
+	bool skip_tree;
+
+	const git_index_entry *entry;
+} index_iterator;
+
+static int index_iterator_current(
+	const git_index_entry **out, git_iterator *i)
+{
+	index_iterator *iter = (index_iterator *)i;
+
+	if (!iterator__has_been_accessed(i))
+		return iter->base.cb->advance(out, i);
+
+	if (iter->entry == NULL) {
+		*out = NULL;
+		return GIT_ITEROVER;
+	}
+
+	*out = iter->entry;
+	return 0;
+}
+
+static bool index_iterator_create_pseudotree(
+	const git_index_entry **out,
+	index_iterator *iter,
+	const char *path)
+{
+	const char *prev_path, *relative_path, *dirsep;
+	size_t common_len;
+
+	prev_path = iter->entry ? iter->entry->path : "";
+
+	/* determine if the new path is in a different directory from the old */
+	common_len = git_path_common_dirlen(prev_path, path);
+	relative_path = path + common_len;
+
+	if ((dirsep = strchr(relative_path, '/')) == NULL)
+		return false;
+
+	git_buf_clear(&iter->tree_buf);
+	git_buf_put(&iter->tree_buf, path, (dirsep - path) + 1);
+
+	iter->tree_entry.mode = GIT_FILEMODE_TREE;
+	iter->tree_entry.path = iter->tree_buf.ptr;
+
+	*out = &iter->tree_entry;
+	return true;
+}
+
+static int index_iterator_skip_pseudotree(index_iterator *iter)
+{
+	assert(iterator__has_been_accessed(&iter->base));
+	assert(S_ISDIR(iter->entry->mode));
+
+	while (true) {
+		const git_index_entry *next_entry = NULL;
+
+		if (++iter->next_idx >= iter->entries.length)
+			return GIT_ITEROVER;
+
+		next_entry = iter->entries.contents[iter->next_idx];
+
+		if (iter->base.strncomp(iter->tree_buf.ptr, next_entry->path,
+			iter->tree_buf.size) != 0)
+			break;
+	}
+
+	iter->skip_tree = false;
+	return 0;
+}
+
+static int index_iterator_advance(
+	const git_index_entry **out, git_iterator *i)
+{
+	index_iterator *iter = (index_iterator *)i;
+	const git_index_entry *entry = NULL;
+	bool is_submodule;
+	int error = 0;
+
+	iter->base.flags |= GIT_ITERATOR_FIRST_ACCESS;
+
+	while (true) {
+		if (iter->next_idx >= iter->entries.length) {
+			error = GIT_ITEROVER;
+			break;
+		}
+
+		/* we were not asked to expand this pseudotree.  advance over it. */
+		if (iter->skip_tree) {
+			index_iterator_skip_pseudotree(iter);
+			continue;
+		}
+
+		entry = iter->entries.contents[iter->next_idx];
+		is_submodule = S_ISGITLINK(entry->mode);
+
+		if (!iterator_has_started(&iter->base, entry->path, is_submodule)) {
+			iter->next_idx++;
+			continue;
+		}
+
+		if (iterator_has_ended(&iter->base, entry->path)) {
+			error = GIT_ITEROVER;
+			break;
+		}
+
+		/* if we have a list of paths we're interested in, examine it */
+		if (!iterator_pathlist_next_is(&iter->base, entry->path)) {
+			iter->next_idx++;
+			continue;
+		}
+
+		/* if this is a conflict, skip it unless we're including conflicts */
+		if (git_index_entry_is_conflict(entry) &&
+			!iterator__include_conflicts(&iter->base)) {
+			iter->next_idx++;
+			continue;
+		}
+
+		/* we've found what will be our next _file_ entry.  but if we are
+		 * returning trees entries, we may need to return a pseudotree
+		 * entry that will contain this.  don't advance over this entry,
+		 * though, we still need to return it on the next `advance`.
+		 */
+		if (iterator__include_trees(&iter->base) &&
+			index_iterator_create_pseudotree(&entry, iter, entry->path)) {
+
+			/* Note whether this pseudo tree should be expanded or not */
+			iter->skip_tree = iterator__dont_autoexpand(&iter->base);
+			break;
+		}
+
+		iter->next_idx++;
+		break;
+	}
+
+	iter->entry = (error == 0) ? entry : NULL;
+
+	if (out)
+		*out = iter->entry;
+
+	return error;
+}
+
+static int index_iterator_advance_into(
+	const git_index_entry **out, git_iterator *i)
+{
+	index_iterator *iter = (index_iterator *)i;
+
+	if (! S_ISDIR(iter->tree_entry.mode)) {
+		if (out)
+			*out = NULL;
+
+		return 0;
+	}
+
+	iter->skip_tree = false;
+	return index_iterator_advance(out, i);
+}
+
+static int index_iterator_advance_over(
+	const git_index_entry **out,
+	git_iterator_status_t *status,
+	git_iterator *i)
+{
+	index_iterator *iter = (index_iterator *)i;
+	const git_index_entry *entry;
+	int error;
+
+	if ((error = index_iterator_current(&entry, i)) < 0)
+		return error;
+
+	if (S_ISDIR(entry->mode))
+		index_iterator_skip_pseudotree(iter);
+
+	*status = GIT_ITERATOR_STATUS_NORMAL;
+	return index_iterator_advance(out, i);
+}
+
+static void index_iterator_clear(index_iterator *iter)
+{
+	iterator_clear(&iter->base);
+}
+
+static int index_iterator_init(index_iterator *iter)
+{
+	iter->base.flags &= ~GIT_ITERATOR_FIRST_ACCESS;
+	iter->next_idx = 0;
+	iter->skip_tree = false;
+	return 0;
+}
+
+static int index_iterator_reset(git_iterator *i)
+{
+	index_iterator *iter = (index_iterator *)i;
+
+	index_iterator_clear(iter);
+	return index_iterator_init(iter);
+}
+
+static void index_iterator_free(git_iterator *i)
+{
+	index_iterator *iter = (index_iterator *)i;
+
+	git_index_snapshot_release(&iter->entries, iter->base.index);
+	git_buf_free(&iter->tree_buf);
+}
+
+int git_iterator_for_index(
+	git_iterator **out,
+	git_repository *repo,
+	git_index  *index,
+	git_iterator_options *options)
+{
+	index_iterator *iter;
+	int error;
+
+	static git_iterator_callbacks callbacks = {
+		index_iterator_current,
+		index_iterator_advance,
+		index_iterator_advance_into,
+		index_iterator_advance_over,
+		index_iterator_reset,
+		index_iterator_free
+	};
+
+	*out = NULL;
+
+	if (index == NULL)
+		return git_iterator_for_nothing(out, options);
+
+	iter = git__calloc(1, sizeof(index_iterator));
+	GITERR_CHECK_ALLOC(iter);
+
+	iter->base.type = GIT_ITERATOR_TYPE_INDEX;
+	iter->base.cb = &callbacks;
+
+	if ((error = iterator_init_common(&iter->base, repo, index, options)) < 0 ||
+		(error = git_index_snapshot_new(&iter->entries, index)) < 0 ||
+		(error = index_iterator_init(iter)) < 0)
+		goto on_error;
+
+	git_vector_set_cmp(&iter->entries, iterator__ignore_case(&iter->base) ?
+		git_index_entry_icmp : git_index_entry_cmp);
+	git_vector_sort(&iter->entries);
+
+	*out = &iter->base;
+	return 0;
+
+on_error:
+	git_iterator_free(&iter->base);
+	return error;
+}
+
+
+/* Iterator API */
+
+int git_iterator_reset_range(
+	git_iterator *i, const char *start, const char *end)
+{
+	if (iterator_reset_range(i, start, end) < 0)
+		return -1;
+
+	return i->cb->reset(i);
+}
+
+void git_iterator_set_ignore_case(git_iterator *i, bool ignore_case)
+{
+	assert(!iterator__has_been_accessed(i));
+	iterator_set_ignore_case(i, ignore_case);
+}
+
+void git_iterator_free(git_iterator *iter)
+{
+	if (iter == NULL)
+		return;
+
+	iter->cb->free(iter);
+
+	git_vector_free(&iter->pathlist);
+	git__free(iter->start);
+	git__free(iter->end);
+
+	memset(iter, 0, sizeof(*iter));
+
+	git__free(iter);
+}
+
+int git_iterator_walk(
+	git_iterator **iterators,
+	size_t cnt,
+	git_iterator_walk_cb cb,
+	void *data)
+{
+	const git_index_entry **iterator_item;	/* next in each iterator */
+	const git_index_entry **cur_items;		/* current path in each iter */
+	const git_index_entry *first_match;
+	size_t i, j;
+	int error = 0;
+
+	iterator_item = git__calloc(cnt, sizeof(git_index_entry *));
+	cur_items = git__calloc(cnt, sizeof(git_index_entry *));
+
+	GITERR_CHECK_ALLOC(iterator_item);
+	GITERR_CHECK_ALLOC(cur_items);
+
+	/* Set up the iterators */
+	for (i = 0; i < cnt; i++) {
+		error = git_iterator_current(&iterator_item[i], iterators[i]);
+
+		if (error < 0 && error != GIT_ITEROVER)
+			goto done;
+	}
+
+	while (true) {
+		for (i = 0; i < cnt; i++)
+			cur_items[i] = NULL;
+
+		first_match = NULL;
+
+		/* Find the next path(s) to consume from each iterator */
+		for (i = 0; i < cnt; i++) {
+			if (iterator_item[i] == NULL)
+				continue;
+
+			if (first_match == NULL) {
+				first_match = iterator_item[i];
+				cur_items[i] = iterator_item[i];
+			} else {
+				int path_diff = git_index_entry_cmp(iterator_item[i], first_match);
+
+				if (path_diff < 0) {
+					/* Found an index entry that sorts before the one we're
+					 * looking at.  Forget that we've seen the other and
+					 * look at the other iterators for this path.
+					 */
+					for (j = 0; j < i; j++)
+						cur_items[j] = NULL;
+
+					first_match = iterator_item[i];
+					cur_items[i] = iterator_item[i];
+				} else if (path_diff == 0) {
+					cur_items[i] = iterator_item[i];
+				}
+			}
+		}
+
+		if (first_match == NULL)
+			break;
+
+		if ((error = cb(cur_items, data)) != 0)
+			goto done;
+
+		/* Advance each iterator that participated */
+		for (i = 0; i < cnt; i++) {
+			if (cur_items[i] == NULL)
+				continue;
+
+			error = git_iterator_advance(&iterator_item[i], iterators[i]);
+
+			if (error < 0 && error != GIT_ITEROVER)
+				goto done;
+		}
+	}
+
+done:
+	git__free((git_index_entry **)iterator_item);
+	git__free((git_index_entry **)cur_items);
+
+	if (error == GIT_ITEROVER)
+		error = 0;
+
+	return error;
+}

vendor/libgit2-sys/libgit2/src/iterator.h

diff --git a/vendor/libgit2-sys/libgit2/src/iterator.h b/vendor/libgit2-sys/libgit2/src/iterator.h
new file mode 100644
index 0000000..a6497d8
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/iterator.h
@@ -0,0 +1,307 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_iterator_h__
+#define INCLUDE_iterator_h__
+
+#include "common.h"
+
+#include "git2/index.h"
+#include "vector.h"
+#include "buffer.h"
+#include "ignore.h"
+
+typedef struct git_iterator git_iterator;
+
+typedef enum {
+	GIT_ITERATOR_TYPE_EMPTY = 0,
+	GIT_ITERATOR_TYPE_TREE = 1,
+	GIT_ITERATOR_TYPE_INDEX = 2,
+	GIT_ITERATOR_TYPE_WORKDIR = 3,
+	GIT_ITERATOR_TYPE_FS = 4,
+} git_iterator_type_t;
+
+typedef enum {
+	/** ignore case for entry sort order */
+	GIT_ITERATOR_IGNORE_CASE = (1u << 0),
+	/** force case sensitivity for entry sort order */
+	GIT_ITERATOR_DONT_IGNORE_CASE = (1u << 1),
+	/** return tree items in addition to blob items */
+	GIT_ITERATOR_INCLUDE_TREES    = (1u << 2),
+	/** don't flatten trees, requiring advance_into (implies INCLUDE_TREES) */
+	GIT_ITERATOR_DONT_AUTOEXPAND  = (1u << 3),
+	/** convert precomposed unicode to decomposed unicode */
+	GIT_ITERATOR_PRECOMPOSE_UNICODE = (1u << 4),
+	/** never convert precomposed unicode to decomposed unicode */
+	GIT_ITERATOR_DONT_PRECOMPOSE_UNICODE = (1u << 5),
+	/** include conflicts */
+	GIT_ITERATOR_INCLUDE_CONFLICTS = (1u << 6),
+	/** descend into symlinked directories */
+	GIT_ITERATOR_DESCEND_SYMLINKS = (1u << 7),
+} git_iterator_flag_t;
+
+typedef enum {
+	GIT_ITERATOR_STATUS_NORMAL = 0,
+	GIT_ITERATOR_STATUS_IGNORED = 1,
+	GIT_ITERATOR_STATUS_EMPTY = 2,
+	GIT_ITERATOR_STATUS_FILTERED = 3
+} git_iterator_status_t;
+
+typedef struct {
+	const char *start;
+	const char *end;
+
+	/* paths to include in the iterator (literal).  if set, any paths not
+	 * listed here will be excluded from iteration.
+	 */
+	git_strarray pathlist;
+
+	/* flags, from above */
+	unsigned int flags;
+} git_iterator_options;
+
+#define GIT_ITERATOR_OPTIONS_INIT {0}
+
+typedef struct {
+	int (*current)(const git_index_entry **, git_iterator *);
+	int (*advance)(const git_index_entry **, git_iterator *);
+	int (*advance_into)(const git_index_entry **, git_iterator *);
+	int (*advance_over)(
+		const git_index_entry **, git_iterator_status_t *, git_iterator *);
+	int (*reset)(git_iterator *);
+	void (*free)(git_iterator *);
+} git_iterator_callbacks;
+
+struct git_iterator {
+	git_iterator_type_t type;
+	git_iterator_callbacks *cb;
+
+	git_repository *repo;
+	git_index *index;
+
+	char *start;
+	size_t start_len;
+
+	char *end;
+	size_t end_len;
+
+	bool started;
+	bool ended;
+	git_vector pathlist;
+	size_t pathlist_walk_idx;
+	int (*strcomp)(const char *a, const char *b);
+	int (*strncomp)(const char *a, const char *b, size_t n);
+	int (*prefixcomp)(const char *str, const char *prefix);
+	int (*entry_srch)(const void *key, const void *array_member);
+	size_t stat_calls;
+	unsigned int flags;
+};
+
+extern int git_iterator_for_nothing(
+	git_iterator **out,
+	git_iterator_options *options);
+
+/* tree iterators will match the ignore_case value from the index of the
+ * repository, unless you override with a non-zero flag value
+ */
+extern int git_iterator_for_tree(
+	git_iterator **out,
+	git_tree *tree,
+	git_iterator_options *options);
+
+/* index iterators will take the ignore_case value from the index; the
+ * ignore_case flags are not used
+ */
+extern int git_iterator_for_index(
+	git_iterator **out,
+	git_repository *repo,
+	git_index *index,
+	git_iterator_options *options);
+
+extern int git_iterator_for_workdir_ext(
+	git_iterator **out,
+	git_repository *repo,
+	const char *repo_workdir,
+	git_index *index,
+	git_tree *tree,
+	git_iterator_options *options);
+
+/* workdir iterators will match the ignore_case value from the index of the
+ * repository, unless you override with a non-zero flag value
+ */
+GIT_INLINE(int) git_iterator_for_workdir(
+	git_iterator **out,
+	git_repository *repo,
+	git_index *index,
+	git_tree *tree,
+	git_iterator_options *options)
+{
+	return git_iterator_for_workdir_ext(out, repo, NULL, index, tree, options);
+}
+
+/* for filesystem iterators, you have to explicitly pass in the ignore_case
+ * behavior that you desire
+ */
+extern int git_iterator_for_filesystem(
+	git_iterator **out,
+	const char *root,
+	git_iterator_options *options);
+
+extern void git_iterator_free(git_iterator *iter);
+
+/* Return a git_index_entry structure for the current value the iterator
+ * is looking at or NULL if the iterator is at the end.
+ *
+ * The entry may noy be fully populated.  Tree iterators will only have a
+ * value mode, OID, and path.  Workdir iterators will not have an OID (but
+ * you can use `git_iterator_current_oid()` to calculate it on demand).
+ *
+ * You do not need to free the entry.  It is still "owned" by the iterator.
+ * Once you call `git_iterator_advance()` then the old entry is no longer
+ * guaranteed to be valid - it may be freed or just overwritten in place.
+ */
+GIT_INLINE(int) git_iterator_current(
+	const git_index_entry **entry, git_iterator *iter)
+{
+	return iter->cb->current(entry, iter);
+}
+
+/**
+ * Advance to the next item for the iterator.
+ *
+ * If GIT_ITERATOR_INCLUDE_TREES is set, this may be a tree item.  If
+ * GIT_ITERATOR_DONT_AUTOEXPAND is set, calling this again when on a tree
+ * item will skip over all the items under that tree.
+ */
+GIT_INLINE(int) git_iterator_advance(
+	const git_index_entry **entry, git_iterator *iter)
+{
+	return iter->cb->advance(entry, iter);
+}
+
+/**
+ * Iterate into a tree item (when GIT_ITERATOR_DONT_AUTOEXPAND is set).
+ *
+ * git_iterator_advance() steps through all items being iterated over
+ * (either with or without trees, depending on GIT_ITERATOR_INCLUDE_TREES),
+ * but if GIT_ITERATOR_DONT_AUTOEXPAND is set, it will skip to the next
+ * sibling of a tree instead of going to the first child of the tree.  In
+ * that case, use this function to advance to the first child of the tree.
+ *
+ * If the current item is not a tree, this is a no-op.
+ *
+ * For filesystem and working directory iterators, a tree (i.e. directory)
+ * can be empty.  In that case, this function returns GIT_ENOTFOUND and
+ * does not advance.  That can't happen for tree and index iterators.
+ */
+GIT_INLINE(int) git_iterator_advance_into(
+	const git_index_entry **entry, git_iterator *iter)
+{
+	return iter->cb->advance_into(entry, iter);
+}
+
+/* Advance over a directory and check if it contains no files or just
+ * ignored files.
+ *
+ * In a tree or the index, all directories will contain files, but in the
+ * working directory it is possible to have an empty directory tree or a
+ * tree that only contains ignored files.  Many Git operations treat these
+ * cases specially.  This advances over a directory (presumably an
+ * untracked directory) but checks during the scan if there are any files
+ * and any non-ignored files.
+ */
+GIT_INLINE(int) git_iterator_advance_over(
+	const git_index_entry **entry,
+	git_iterator_status_t *status,
+	git_iterator *iter)
+{
+	return iter->cb->advance_over(entry, status, iter);
+}
+
+/**
+ * Go back to the start of the iteration.
+ */
+GIT_INLINE(int) git_iterator_reset(git_iterator *iter)
+{
+	return iter->cb->reset(iter);
+}
+
+/**
+ * Go back to the start of the iteration after updating the `start` and
+ * `end` pathname boundaries of the iteration.
+ */
+extern int git_iterator_reset_range(
+	git_iterator *iter, const char *start, const char *end);
+
+GIT_INLINE(git_iterator_type_t) git_iterator_type(git_iterator *iter)
+{
+	return iter->type;
+}
+
+GIT_INLINE(git_repository *) git_iterator_owner(git_iterator *iter)
+{
+	return iter->repo;
+}
+
+GIT_INLINE(git_index *) git_iterator_index(git_iterator *iter)
+{
+	return iter->index;
+}
+
+GIT_INLINE(git_iterator_flag_t) git_iterator_flags(git_iterator *iter)
+{
+	return iter->flags;
+}
+
+GIT_INLINE(bool) git_iterator_ignore_case(git_iterator *iter)
+{
+	return ((iter->flags & GIT_ITERATOR_IGNORE_CASE) != 0);
+}
+
+extern void git_iterator_set_ignore_case(
+	git_iterator *iter, bool ignore_case);
+
+extern int git_iterator_current_tree_entry(
+	const git_tree_entry **entry_out, git_iterator *iter);
+
+extern int git_iterator_current_parent_tree(
+	const git_tree **tree_out, git_iterator *iter, size_t depth);
+
+extern bool git_iterator_current_is_ignored(git_iterator *iter);
+
+extern bool git_iterator_current_tree_is_ignored(git_iterator *iter);
+
+/**
+ * Get full path of the current item from a workdir iterator.  This will
+ * return NULL for a non-workdir iterator.  The git_buf is still owned by
+ * the iterator; this is exposed just for efficiency.
+ */
+extern int git_iterator_current_workdir_path(
+	git_buf **path, git_iterator *iter);
+
+/**
+ * Retrieve the index stored in the iterator.
+ *
+ * Only implemented for the workdir and index iterators.
+ */
+extern git_index *git_iterator_index(git_iterator *iter);
+
+typedef int (*git_iterator_walk_cb)(
+	const git_index_entry **entries,
+	void *data);
+
+/**
+ * Walk the given iterators in lock-step.  The given callback will be
+ * called for each unique path, with the index entry in each iterator
+ * (or NULL if the given iterator does not contain that path).
+ */
+extern int git_iterator_walk(
+	git_iterator **iterators,
+	size_t cnt,
+	git_iterator_walk_cb cb,
+	void *data);
+
+#endif

vendor/libgit2-sys/libgit2/src/khash.h

diff --git a/vendor/libgit2-sys/libgit2/src/khash.h b/vendor/libgit2-sys/libgit2/src/khash.h
new file mode 100644
index 0000000..71eb583
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/khash.h
@@ -0,0 +1,622 @@
+/* The MIT License
+
+   Copyright (c) 2008, 2009, 2011 by Attractive Chaos <attractor@live.co.uk>
+
+   Permission is hereby granted, free of charge, to any person obtaining
+   a copy of this software and associated documentation files (the
+   "Software"), to deal in the Software without restriction, including
+   without limitation the rights to use, copy, modify, merge, publish,
+   distribute, sublicense, and/or sell copies of the Software, and to
+   permit persons to whom the Software is furnished to do so, subject to
+   the following conditions:
+
+   The above copyright notice and this permission notice shall be
+   included in all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+   BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+   ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+   CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+   SOFTWARE.
+*/
+
+/*
+  An example:
+
+#include "khash.h"
+KHASH_MAP_INIT_INT(32, char)
+int main() {
+	int ret, is_missing;
+	khiter_t k;
+	khash_t(32) *h = kh_init(32);
+	k = kh_put(32, h, 5, &ret);
+	kh_value(h, k) = 10;
+	k = kh_get(32, h, 10);
+	is_missing = (k == kh_end(h));
+	k = kh_get(32, h, 5);
+	kh_del(32, h, k);
+	for (k = kh_begin(h); k != kh_end(h); ++k)
+		if (kh_exist(h, k)) kh_value(h, k) = 1;
+	kh_destroy(32, h);
+	return 0;
+}
+*/
+
+/*
+  2013-05-02 (0.2.8):
+
+	* Use quadratic probing. When the capacity is power of 2, stepping function
+	  i*(i+1)/2 guarantees to traverse each bucket. It is better than double
+	  hashing on cache performance and is more robust than linear probing.
+
+	  In theory, double hashing should be more robust than quadratic probing.
+	  However, my implementation is probably not for large hash tables, because
+	  the second hash function is closely tied to the first hash function,
+	  which reduce the effectiveness of double hashing.
+
+	Reference: http://research.cs.vt.edu/AVresearch/hashing/quadratic.php
+
+  2011-12-29 (0.2.7):
+
+    * Minor code clean up; no actual effect.
+
+  2011-09-16 (0.2.6):
+
+	* The capacity is a power of 2. This seems to dramatically improve the
+	  speed for simple keys. Thank Zilong Tan for the suggestion. Reference:
+
+	   - http://code.google.com/p/ulib/
+	   - http://nothings.org/computer/judy/
+
+	* Allow to optionally use linear probing which usually has better
+	  performance for random input. Double hashing is still the default as it
+	  is more robust to certain non-random input.
+
+	* Added Wang's integer hash function (not used by default). This hash
+	  function is more robust to certain non-random input.
+
+  2011-02-14 (0.2.5):
+
+    * Allow to declare global functions.
+
+  2009-09-26 (0.2.4):
+
+    * Improve portability
+
+  2008-09-19 (0.2.3):
+
+	* Corrected the example
+	* Improved interfaces
+
+  2008-09-11 (0.2.2):
+
+	* Improved speed a little in kh_put()
+
+  2008-09-10 (0.2.1):
+
+	* Added kh_clear()
+	* Fixed a compiling error
+
+  2008-09-02 (0.2.0):
+
+	* Changed to token concatenation which increases flexibility.
+
+  2008-08-31 (0.1.2):
+
+	* Fixed a bug in kh_get(), which has not been tested previously.
+
+  2008-08-31 (0.1.1):
+
+	* Added destructor
+*/
+
+
+#ifndef __AC_KHASH_H
+#define __AC_KHASH_H
+
+/*!
+  @header
+
+  Generic hash table library.
+ */
+
+#define AC_VERSION_KHASH_H "0.2.8"
+
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+
+/* compiler specific configuration */
+
+#if UINT_MAX == 0xffffffffu
+typedef unsigned int khint32_t;
+#elif ULONG_MAX == 0xffffffffu
+typedef unsigned long khint32_t;
+#endif
+
+#if ULONG_MAX == ULLONG_MAX
+typedef unsigned long khint64_t;
+#else
+typedef unsigned long long khint64_t;
+#endif
+
+#ifndef kh_inline
+#ifdef _MSC_VER
+#define kh_inline __inline
+#else
+#define kh_inline inline
+#endif
+#endif /* kh_inline */
+
+typedef khint32_t khint_t;
+typedef khint_t khiter_t;
+
+#define __ac_isempty(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&2)
+#define __ac_isdel(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&1)
+#define __ac_iseither(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&3)
+#define __ac_set_isdel_false(flag, i) (flag[i>>4]&=~(1ul<<((i&0xfU)<<1)))
+#define __ac_set_isempty_false(flag, i) (flag[i>>4]&=~(2ul<<((i&0xfU)<<1)))
+#define __ac_set_isboth_false(flag, i) (flag[i>>4]&=~(3ul<<((i&0xfU)<<1)))
+#define __ac_set_isdel_true(flag, i) (flag[i>>4]|=1ul<<((i&0xfU)<<1))
+
+#define __ac_fsize(m) ((m) < 16? 1 : (m)>>4)
+
+#ifndef kroundup32
+#define kroundup32(x) (--(x), (x)|=(x)>>1, (x)|=(x)>>2, (x)|=(x)>>4, (x)|=(x)>>8, (x)|=(x)>>16, ++(x))
+#endif
+
+#ifndef kcalloc
+#define kcalloc(N,Z) calloc(N,Z)
+#endif
+#ifndef kmalloc
+#define kmalloc(Z) malloc(Z)
+#endif
+#ifndef krealloc
+#define krealloc(P,Z) realloc(P,Z)
+#endif
+#ifndef kreallocarray
+#define kreallocarray(P,N,Z) ((SIZE_MAX - N < Z) ? NULL : krealloc(P, (N*Z)))
+#endif
+#ifndef kfree
+#define kfree(P) free(P)
+#endif
+
+static const double __ac_HASH_UPPER = 0.77;
+
+#define __KHASH_TYPE(name, khkey_t, khval_t) \
+	typedef struct kh_##name##_s { \
+		khint_t n_buckets, size, n_occupied, upper_bound; \
+		khint32_t *flags; \
+		khkey_t *keys; \
+		khval_t *vals; \
+	} kh_##name##_t;
+
+#define __KHASH_PROTOTYPES(name, khkey_t, khval_t)	 					\
+	extern kh_##name##_t *kh_init_##name(void);							\
+	extern void kh_destroy_##name(kh_##name##_t *h);					\
+	extern void kh_clear_##name(kh_##name##_t *h);						\
+	extern khint_t kh_get_##name(const kh_##name##_t *h, khkey_t key); 	\
+	extern int kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets); \
+	extern khint_t kh_put_##name(kh_##name##_t *h, khkey_t key, int *ret); \
+	extern void kh_del_##name(kh_##name##_t *h, khint_t x);
+
+#define __KHASH_IMPL(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \
+	SCOPE kh_##name##_t *kh_init_##name(void) {							\
+		return (kh_##name##_t*)kcalloc(1, sizeof(kh_##name##_t));		\
+	}																	\
+	SCOPE void kh_destroy_##name(kh_##name##_t *h)						\
+	{																	\
+		if (h) {														\
+			kfree((void *)h->keys); kfree(h->flags);					\
+			kfree((void *)h->vals);										\
+			kfree(h);													\
+		}																\
+	}																	\
+	SCOPE void kh_clear_##name(kh_##name##_t *h)						\
+	{																	\
+		if (h && h->flags) {											\
+			memset(h->flags, 0xaa, __ac_fsize(h->n_buckets) * sizeof(khint32_t)); \
+			h->size = h->n_occupied = 0;								\
+		}																\
+	}																	\
+	SCOPE khint_t kh_get_##name(const kh_##name##_t *h, khkey_t key) 	\
+	{																	\
+		if (h->n_buckets) {												\
+			khint_t k, i, last, mask, step = 0; \
+			mask = h->n_buckets - 1;									\
+			k = __hash_func(key); i = k & mask;							\
+			last = i; \
+			while (!__ac_isempty(h->flags, i) && (__ac_isdel(h->flags, i) || !__hash_equal(h->keys[i], key))) { \
+				i = (i + (++step)) & mask; \
+				if (i == last) return h->n_buckets;						\
+			}															\
+			return __ac_iseither(h->flags, i)? h->n_buckets : i;		\
+		} else return 0;												\
+	}																	\
+	SCOPE int kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets) \
+	{ /* This function uses 0.25*n_buckets bytes of working space instead of [sizeof(key_t+val_t)+.25]*n_buckets. */ \
+		khint32_t *new_flags = 0;										\
+		khint_t j = 1;													\
+		{																\
+			kroundup32(new_n_buckets); 									\
+			if (new_n_buckets < 4) new_n_buckets = 4;					\
+			if (h->size >= (khint_t)(new_n_buckets * __ac_HASH_UPPER + 0.5)) j = 0;	/* requested size is too small */ \
+			else { /* hash table size to be changed (shrink or expand); rehash */ \
+				new_flags = (khint32_t*)kreallocarray(NULL, __ac_fsize(new_n_buckets), sizeof(khint32_t)); \
+				if (!new_flags) return -1;								\
+				memset(new_flags, 0xaa, __ac_fsize(new_n_buckets) * sizeof(khint32_t)); \
+				if (h->n_buckets < new_n_buckets) {	/* expand */		\
+					khkey_t *new_keys = (khkey_t*)kreallocarray((void *)h->keys, new_n_buckets, sizeof(khkey_t)); \
+					if (!new_keys) { kfree(new_flags); return -1; }		\
+					h->keys = new_keys;									\
+					if (kh_is_map) {									\
+						khval_t *new_vals = (khval_t*)kreallocarray((void *)h->vals, new_n_buckets, sizeof(khval_t)); \
+						if (!new_vals) { kfree(new_flags); return -1; }	\
+						h->vals = new_vals;								\
+					}													\
+				} /* otherwise shrink */								\
+			}															\
+		}																\
+		if (j) { /* rehashing is needed */								\
+			for (j = 0; j != h->n_buckets; ++j) {						\
+				if (__ac_iseither(h->flags, j) == 0) {					\
+					khkey_t key = h->keys[j];							\
+					khval_t val;										\
+					khint_t new_mask;									\
+					new_mask = new_n_buckets - 1; 						\
+					if (kh_is_map) val = h->vals[j];					\
+					__ac_set_isdel_true(h->flags, j);					\
+					while (1) { /* kick-out process; sort of like in Cuckoo hashing */ \
+						khint_t k, i, step = 0; \
+						k = __hash_func(key);							\
+						i = k & new_mask;								\
+						while (!__ac_isempty(new_flags, i)) i = (i + (++step)) & new_mask; \
+						__ac_set_isempty_false(new_flags, i);			\
+						if (i < h->n_buckets && __ac_iseither(h->flags, i) == 0) { /* kick out the existing element */ \
+							{ khkey_t tmp = h->keys[i]; h->keys[i] = key; key = tmp; } \
+							if (kh_is_map) { khval_t tmp = h->vals[i]; h->vals[i] = val; val = tmp; } \
+							__ac_set_isdel_true(h->flags, i); /* mark it as deleted in the old hash table */ \
+						} else { /* write the element and jump out of the loop */ \
+							h->keys[i] = key;							\
+							if (kh_is_map) h->vals[i] = val;			\
+							break;										\
+						}												\
+					}													\
+				}														\
+			}															\
+			if (h->n_buckets > new_n_buckets) { /* shrink the hash table */ \
+				h->keys = (khkey_t*)kreallocarray((void *)h->keys, new_n_buckets, sizeof(khkey_t)); \
+				if (kh_is_map) h->vals = (khval_t*)kreallocarray((void *)h->vals, new_n_buckets, sizeof(khval_t)); \
+			}															\
+			kfree(h->flags); /* free the working space */				\
+			h->flags = new_flags;										\
+			h->n_buckets = new_n_buckets;								\
+			h->n_occupied = h->size;									\
+			h->upper_bound = (khint_t)(h->n_buckets * __ac_HASH_UPPER + 0.5); \
+		}																\
+		return 0;														\
+	}																	\
+	SCOPE khint_t kh_put_##name(kh_##name##_t *h, khkey_t key, int *ret) \
+	{																	\
+		khint_t x;														\
+		if (h->n_occupied >= h->upper_bound) { /* update the hash table */ \
+			if (h->n_buckets > (h->size<<1)) {							\
+				if (kh_resize_##name(h, h->n_buckets - 1) < 0) { /* clear "deleted" elements */ \
+					*ret = -1; return h->n_buckets;						\
+				}														\
+			} else if (kh_resize_##name(h, h->n_buckets + 1) < 0) { /* expand the hash table */ \
+				*ret = -1; return h->n_buckets;							\
+			}															\
+		} /* TODO: to implement automatically shrinking; resize() already support shrinking */ \
+		{																\
+			khint_t k, i, site, last, mask = h->n_buckets - 1, step = 0; \
+			x = site = h->n_buckets; k = __hash_func(key); i = k & mask; \
+			if (__ac_isempty(h->flags, i)) x = i; /* for speed up */	\
+			else {														\
+				last = i; \
+				while (!__ac_isempty(h->flags, i) && (__ac_isdel(h->flags, i) || !__hash_equal(h->keys[i], key))) { \
+					if (__ac_isdel(h->flags, i)) site = i;				\
+					i = (i + (++step)) & mask; \
+					if (i == last) { x = site; break; }					\
+				}														\
+				if (x == h->n_buckets) {								\
+					if (__ac_isempty(h->flags, i) && site != h->n_buckets) x = site; \
+					else x = i;											\
+				}														\
+			}															\
+		}																\
+		if (__ac_isempty(h->flags, x)) { /* not present at all */		\
+			h->keys[x] = key;											\
+			__ac_set_isboth_false(h->flags, x);							\
+			++h->size; ++h->n_occupied;									\
+			*ret = 1;													\
+		} else if (__ac_isdel(h->flags, x)) { /* deleted */				\
+			h->keys[x] = key;											\
+			__ac_set_isboth_false(h->flags, x);							\
+			++h->size;													\
+			*ret = 2;													\
+		} else *ret = 0; /* Don't touch h->keys[x] if present and not deleted */ \
+		return x;														\
+	}																	\
+	SCOPE void kh_del_##name(kh_##name##_t *h, khint_t x)				\
+	{																	\
+		if (x != h->n_buckets && !__ac_iseither(h->flags, x)) {			\
+			__ac_set_isdel_true(h->flags, x);							\
+			--h->size;													\
+		}																\
+	}
+
+#define KHASH_DECLARE(name, khkey_t, khval_t)		 					\
+	__KHASH_TYPE(name, khkey_t, khval_t) 								\
+	__KHASH_PROTOTYPES(name, khkey_t, khval_t)
+
+#define KHASH_INIT2(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \
+	__KHASH_TYPE(name, khkey_t, khval_t) 								\
+	__KHASH_IMPL(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal)
+
+#define KHASH_INIT(name, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \
+	KHASH_INIT2(name, static kh_inline, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal)
+
+/* --- BEGIN OF HASH FUNCTIONS --- */
+
+/*! @function
+  @abstract     Integer hash function
+  @param  key   The integer [khint32_t]
+  @return       The hash value [khint_t]
+ */
+#define kh_int_hash_func(key) (khint32_t)(key)
+/*! @function
+  @abstract     Integer comparison function
+ */
+#define kh_int_hash_equal(a, b) ((a) == (b))
+/*! @function
+  @abstract     64-bit integer hash function
+  @param  key   The integer [khint64_t]
+  @return       The hash value [khint_t]
+ */
+#define kh_int64_hash_func(key) (khint32_t)((key)>>33^(key)^(key)<<11)
+/*! @function
+  @abstract     64-bit integer comparison function
+ */
+#define kh_int64_hash_equal(a, b) ((a) == (b))
+/*! @function
+  @abstract     const char* hash function
+  @param  s     Pointer to a null terminated string
+  @return       The hash value
+ */
+static kh_inline khint_t __ac_X31_hash_string(const char *s)
+{
+	khint_t h = (khint_t)*s;
+	if (h) for (++s ; *s; ++s) h = (h << 5) - h + (khint_t)*s;
+	return h;
+}
+/*! @function
+  @abstract     Another interface to const char* hash function
+  @param  key   Pointer to a null terminated string [const char*]
+  @return       The hash value [khint_t]
+ */
+#define kh_str_hash_func(key) __ac_X31_hash_string(key)
+/*! @function
+  @abstract     Const char* comparison function
+ */
+#define kh_str_hash_equal(a, b) (strcmp(a, b) == 0)
+
+static kh_inline khint_t __ac_Wang_hash(khint_t key)
+{
+    key += ~(key << 15);
+    key ^=  (key >> 10);
+    key +=  (key << 3);
+    key ^=  (key >> 6);
+    key += ~(key << 11);
+    key ^=  (key >> 16);
+    return key;
+}
+#define kh_int_hash_func2(k) __ac_Wang_hash((khint_t)key)
+
+/* --- END OF HASH FUNCTIONS --- */
+
+/* Other convenient macros... */
+
+/*!
+  @abstract Type of the hash table.
+  @param  name  Name of the hash table [symbol]
+ */
+#define khash_t(name) kh_##name##_t
+
+/*! @function
+  @abstract     Initiate a hash table.
+  @param  name  Name of the hash table [symbol]
+  @return       Pointer to the hash table [khash_t(name)*]
+ */
+#define kh_init(name) kh_init_##name()
+
+/*! @function
+  @abstract     Destroy a hash table.
+  @param  name  Name of the hash table [symbol]
+  @param  h     Pointer to the hash table [khash_t(name)*]
+ */
+#define kh_destroy(name, h) kh_destroy_##name(h)
+
+/*! @function
+  @abstract     Reset a hash table without deallocating memory.
+  @param  name  Name of the hash table [symbol]
+  @param  h     Pointer to the hash table [khash_t(name)*]
+ */
+#define kh_clear(name, h) kh_clear_##name(h)
+
+/*! @function
+  @abstract     Resize a hash table.
+  @param  name  Name of the hash table [symbol]
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @param  s     New size [khint_t]
+ */
+#define kh_resize(name, h, s) kh_resize_##name(h, s)
+
+/*! @function
+  @abstract     Insert a key to the hash table.
+  @param  name  Name of the hash table [symbol]
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @param  k     Key [type of keys]
+  @param  r     Extra return code: -1 if the operation failed;
+                0 if the key is present in the hash table;
+                1 if the bucket is empty (never used); 2 if the element in
+				the bucket has been deleted [int*]
+  @return       Iterator to the inserted element [khint_t]
+ */
+#define kh_put(name, h, k, r) kh_put_##name(h, k, r)
+
+/*! @function
+  @abstract     Retrieve a key from the hash table.
+  @param  name  Name of the hash table [symbol]
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @param  k     Key [type of keys]
+  @return       Iterator to the found element, or kh_end(h) if the element is absent [khint_t]
+ */
+#define kh_get(name, h, k) kh_get_##name(h, k)
+
+/*! @function
+  @abstract     Remove a key from the hash table.
+  @param  name  Name of the hash table [symbol]
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @param  k     Iterator to the element to be deleted [khint_t]
+ */
+#define kh_del(name, h, k) kh_del_##name(h, k)
+
+/*! @function
+  @abstract     Test whether a bucket contains data.
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @param  x     Iterator to the bucket [khint_t]
+  @return       1 if containing data; 0 otherwise [int]
+ */
+#define kh_exist(h, x) (!__ac_iseither((h)->flags, (x)))
+
+/*! @function
+  @abstract     Get key given an iterator
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @param  x     Iterator to the bucket [khint_t]
+  @return       Key [type of keys]
+ */
+#define kh_key(h, x) ((h)->keys[x])
+
+/*! @function
+  @abstract     Get value given an iterator
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @param  x     Iterator to the bucket [khint_t]
+  @return       Value [type of values]
+  @discussion   For hash sets, calling this results in segfault.
+ */
+#define kh_val(h, x) ((h)->vals[x])
+
+/*! @function
+  @abstract     Alias of kh_val()
+ */
+#define kh_value(h, x) ((h)->vals[x])
+
+/*! @function
+  @abstract     Get the start iterator
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @return       The start iterator [khint_t]
+ */
+#define kh_begin(h) (khint_t)(0)
+
+/*! @function
+  @abstract     Get the end iterator
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @return       The end iterator [khint_t]
+ */
+#define kh_end(h) ((h)->n_buckets)
+
+/*! @function
+  @abstract     Get the number of elements in the hash table
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @return       Number of elements in the hash table [khint_t]
+ */
+#define kh_size(h) ((h)->size)
+
+/*! @function
+  @abstract     Get the number of buckets in the hash table
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @return       Number of buckets in the hash table [khint_t]
+ */
+#define kh_n_buckets(h) ((h)->n_buckets)
+
+/*! @function
+  @abstract     Iterate over the entries in the hash table
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @param  kvar  Variable to which key will be assigned
+  @param  vvar  Variable to which value will be assigned
+  @param  code  Block of code to execute
+ */
+#define kh_foreach(h, kvar, vvar, code) { khint_t __i;		\
+	for (__i = kh_begin(h); __i != kh_end(h); ++__i) {		\
+		if (!kh_exist(h,__i)) continue;						\
+		(kvar) = kh_key(h,__i);								\
+		(vvar) = kh_val(h,__i);								\
+		code;												\
+	} }
+
+/*! @function
+  @abstract     Iterate over the values in the hash table
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @param  vvar  Variable to which value will be assigned
+  @param  code  Block of code to execute
+ */
+#define kh_foreach_value(h, vvar, code) { khint_t __i;		\
+	for (__i = kh_begin(h); __i != kh_end(h); ++__i) {		\
+		if (!kh_exist(h,__i)) continue;						\
+		(vvar) = kh_val(h,__i);								\
+		code;												\
+	} }
+
+/* More conenient interfaces */
+
+/*! @function
+  @abstract     Instantiate a hash set containing integer keys
+  @param  name  Name of the hash table [symbol]
+ */
+#define KHASH_SET_INIT_INT(name)										\
+	KHASH_INIT(name, khint32_t, char, 0, kh_int_hash_func, kh_int_hash_equal)
+
+/*! @function
+  @abstract     Instantiate a hash map containing integer keys
+  @param  name  Name of the hash table [symbol]
+  @param  khval_t  Type of values [type]
+ */
+#define KHASH_MAP_INIT_INT(name, khval_t)								\
+	KHASH_INIT(name, khint32_t, khval_t, 1, kh_int_hash_func, kh_int_hash_equal)
+
+/*! @function
+  @abstract     Instantiate a hash map containing 64-bit integer keys
+  @param  name  Name of the hash table [symbol]
+ */
+#define KHASH_SET_INIT_INT64(name)										\
+	KHASH_INIT(name, khint64_t, char, 0, kh_int64_hash_func, kh_int64_hash_equal)
+
+/*! @function
+  @abstract     Instantiate a hash map containing 64-bit integer keys
+  @param  name  Name of the hash table [symbol]
+  @param  khval_t  Type of values [type]
+ */
+#define KHASH_MAP_INIT_INT64(name, khval_t)								\
+	KHASH_INIT(name, khint64_t, khval_t, 1, kh_int64_hash_func, kh_int64_hash_equal)
+
+typedef const char *kh_cstr_t;
+/*! @function
+  @abstract     Instantiate a hash map containing const char* keys
+  @param  name  Name of the hash table [symbol]
+ */
+#define KHASH_SET_INIT_STR(name)										\
+	KHASH_INIT(name, kh_cstr_t, char, 0, kh_str_hash_func, kh_str_hash_equal)
+
+/*! @function
+  @abstract     Instantiate a hash map containing const char* keys
+  @param  name  Name of the hash table [symbol]
+  @param  khval_t  Type of values [type]
+ */
+#define KHASH_MAP_INIT_STR(name, khval_t)								\
+	KHASH_INIT(name, kh_cstr_t, khval_t, 1, kh_str_hash_func, kh_str_hash_equal)
+
+#endif /* __AC_KHASH_H */

vendor/libgit2-sys/libgit2/src/map.h

diff --git a/vendor/libgit2-sys/libgit2/src/map.h b/vendor/libgit2-sys/libgit2/src/map.h
new file mode 100644
index 0000000..2009c3a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/map.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_map_h__
+#define INCLUDE_map_h__
+
+#include "common.h"
+
+
+/* p_mmap() prot values */
+#define GIT_PROT_NONE 0x0
+#define GIT_PROT_READ 0x1
+#define GIT_PROT_WRITE 0x2
+#define GIT_PROT_EXEC 0x4
+
+/* git__mmmap() flags values */
+#define GIT_MAP_FILE	0
+#define GIT_MAP_SHARED 1
+#define GIT_MAP_PRIVATE 2
+#define GIT_MAP_TYPE	0xf
+#define GIT_MAP_FIXED	0x10
+
+#ifdef __amigaos4__
+#define MAP_FAILED 0
+#endif
+
+typedef struct { /* memory mapped buffer	*/
+	void *data; /* data bytes			*/
+	size_t len; /* data length			*/
+#ifdef GIT_WIN32
+	HANDLE fmh; /* file mapping handle */
+#endif
+} git_map;
+
+#define GIT_MMAP_VALIDATE(out, len, prot, flags) do { \
+	assert(out != NULL && len > 0); \
+	assert((prot & GIT_PROT_WRITE) || (prot & GIT_PROT_READ)); \
+	assert((flags & GIT_MAP_FIXED) == 0); } while (0)
+
+extern int p_mmap(git_map *out, size_t len, int prot, int flags, int fd, git_off_t offset);
+extern int p_munmap(git_map *map);
+
+#endif

vendor/libgit2-sys/libgit2/src/merge.c

diff --git a/vendor/libgit2-sys/libgit2/src/merge.c b/vendor/libgit2-sys/libgit2/src/merge.c
new file mode 100644
index 0000000..6c98d13
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/merge.c
@@ -0,0 +1,3326 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "merge.h"
+
+#include "posix.h"
+#include "buffer.h"
+#include "repository.h"
+#include "revwalk.h"
+#include "commit_list.h"
+#include "path.h"
+#include "refs.h"
+#include "object.h"
+#include "iterator.h"
+#include "refs.h"
+#include "diff.h"
+#include "diff_generate.h"
+#include "diff_tform.h"
+#include "checkout.h"
+#include "tree.h"
+#include "blob.h"
+#include "oid.h"
+#include "index.h"
+#include "filebuf.h"
+#include "config.h"
+#include "oidarray.h"
+#include "annotated_commit.h"
+#include "commit.h"
+#include "oidarray.h"
+#include "merge_driver.h"
+#include "oidmap.h"
+#include "array.h"
+
+#include "git2/types.h"
+#include "git2/repository.h"
+#include "git2/object.h"
+#include "git2/commit.h"
+#include "git2/merge.h"
+#include "git2/refs.h"
+#include "git2/reset.h"
+#include "git2/checkout.h"
+#include "git2/signature.h"
+#include "git2/config.h"
+#include "git2/tree.h"
+#include "git2/oidarray.h"
+#include "git2/annotated_commit.h"
+#include "git2/sys/index.h"
+#include "git2/sys/hashsig.h"
+
+#define GIT_MERGE_INDEX_ENTRY_EXISTS(X)	((X).mode != 0)
+#define GIT_MERGE_INDEX_ENTRY_ISFILE(X) S_ISREG((X).mode)
+
+
+typedef enum {
+	TREE_IDX_ANCESTOR = 0,
+	TREE_IDX_OURS = 1,
+	TREE_IDX_THEIRS = 2
+} merge_tree_index_t;
+
+/* Tracks D/F conflicts */
+struct merge_diff_df_data {
+	const char *df_path;
+	const char *prev_path;
+	git_merge_diff *prev_conflict;
+};
+
+/* Merge base computation */
+
+int merge_bases_many(git_commit_list **out, git_revwalk **walk_out, git_repository *repo, size_t length, const git_oid input_array[])
+{
+	git_revwalk *walk = NULL;
+	git_vector list;
+	git_commit_list *result = NULL;
+	git_commit_list_node *commit;
+	int error = -1;
+	unsigned int i;
+
+	if (length < 2) {
+		giterr_set(GITERR_INVALID, "at least two commits are required to find an ancestor");
+		return -1;
+	}
+
+	if (git_vector_init(&list, length - 1, NULL) < 0)
+		return -1;
+
+	if (git_revwalk_new(&walk, repo) < 0)
+		goto on_error;
+
+	for (i = 1; i < length; i++) {
+		commit = git_revwalk__commit_lookup(walk, &input_array[i]);
+		if (commit == NULL)
+			goto on_error;
+
+		git_vector_insert(&list, commit);
+	}
+
+	commit = git_revwalk__commit_lookup(walk, &input_array[0]);
+	if (commit == NULL)
+		goto on_error;
+
+	if (git_merge__bases_many(&result, walk, commit, &list) < 0)
+		goto on_error;
+
+	if (!result) {
+		giterr_set(GITERR_MERGE, "no merge base found");
+		error = GIT_ENOTFOUND;
+		goto on_error;
+	}
+
+	*out = result;
+	*walk_out = walk;
+
+	git_vector_free(&list);
+	return 0;
+
+on_error:
+	git_vector_free(&list);
+	git_revwalk_free(walk);
+	return error;
+}
+
+int git_merge_base_many(git_oid *out, git_repository *repo, size_t length, const git_oid input_array[])
+{
+	git_revwalk *walk;
+	git_commit_list *result = NULL;
+	int error = 0;
+
+	assert(out && repo && input_array);
+
+	if ((error = merge_bases_many(&result, &walk, repo, length, input_array)) < 0)
+		return error;
+
+	git_oid_cpy(out, &result->item->oid);
+
+	git_commit_list_free(&result);
+	git_revwalk_free(walk);
+
+	return 0;
+}
+
+int git_merge_bases_many(git_oidarray *out, git_repository *repo, size_t length, const git_oid input_array[])
+{
+	git_revwalk *walk;
+	git_commit_list *list, *result = NULL;
+	int error = 0;
+	git_array_oid_t array;
+
+	assert(out && repo && input_array);
+
+	if ((error = merge_bases_many(&result, &walk, repo, length, input_array)) < 0)
+		return error;
+
+	git_array_init(array);
+
+	list = result;
+	while (list) {
+		git_oid *id = git_array_alloc(array);
+		if (id == NULL) {
+			error = -1;
+			goto cleanup;
+		}
+
+		git_oid_cpy(id, &list->item->oid);
+		list = list->next;
+	}
+
+	git_oidarray__from_array(out, &array);
+
+cleanup:
+	git_commit_list_free(&result);
+	git_revwalk_free(walk);
+
+	return error;
+}
+
+int git_merge_base_octopus(git_oid *out, git_repository *repo, size_t length, const git_oid input_array[])
+{
+	git_oid result;
+	unsigned int i;
+	int error = -1;
+
+	assert(out && repo && input_array);
+
+	if (length < 2) {
+		giterr_set(GITERR_INVALID, "at least two commits are required to find an ancestor");
+		return -1;
+	}
+
+	result = input_array[0];
+	for (i = 1; i < length; i++) {
+		error = git_merge_base(&result, repo, &result, &input_array[i]);
+		if (error < 0)
+			return error;
+	}
+
+	*out = result;
+
+	return 0;
+}
+
+static int merge_bases(git_commit_list **out, git_revwalk **walk_out, git_repository *repo, const git_oid *one, const git_oid *two)
+{
+	git_revwalk *walk;
+	git_vector list;
+	git_commit_list *result = NULL;
+	git_commit_list_node *commit;
+	void *contents[1];
+
+	if (git_revwalk_new(&walk, repo) < 0)
+		return -1;
+
+	commit = git_revwalk__commit_lookup(walk, two);
+	if (commit == NULL)
+		goto on_error;
+
+	/* This is just one value, so we can do it on the stack */
+	memset(&list, 0x0, sizeof(git_vector));
+	contents[0] = commit;
+	list.length = 1;
+	list.contents = contents;
+
+	commit = git_revwalk__commit_lookup(walk, one);
+	if (commit == NULL)
+		goto on_error;
+
+	if (git_merge__bases_many(&result, walk, commit, &list) < 0)
+		goto on_error;
+
+	if (!result) {
+		git_revwalk_free(walk);
+		giterr_set(GITERR_MERGE, "no merge base found");
+		return GIT_ENOTFOUND;
+	}
+
+	*out = result;
+	*walk_out = walk;
+
+	return 0;
+
+on_error:
+	git_revwalk_free(walk);
+	return -1;
+
+}
+
+int git_merge_base(git_oid *out, git_repository *repo, const git_oid *one, const git_oid *two)
+{
+	int error;
+	git_revwalk *walk;
+	git_commit_list *result;
+
+	if ((error = merge_bases(&result, &walk, repo, one, two)) < 0)
+		return error;
+
+	git_oid_cpy(out, &result->item->oid);
+	git_commit_list_free(&result);
+	git_revwalk_free(walk);
+
+	return 0;
+}
+
+int git_merge_bases(git_oidarray *out, git_repository *repo, const git_oid *one, const git_oid *two)
+{
+	int error;
+	git_revwalk *walk;
+	git_commit_list *result, *list;
+	git_array_oid_t array;
+
+	git_array_init(array);
+
+	if ((error = merge_bases(&result, &walk, repo, one, two)) < 0)
+		return error;
+
+	list = result;
+	while (list) {
+		git_oid *id = git_array_alloc(array);
+		if (id == NULL)
+			goto on_error;
+
+		git_oid_cpy(id, &list->item->oid);
+		list = list->next;
+	}
+
+	git_oidarray__from_array(out, &array);
+	git_commit_list_free(&result);
+	git_revwalk_free(walk);
+
+	return 0;
+
+on_error:
+	git_commit_list_free(&result);
+	git_revwalk_free(walk);
+	return -1;
+}
+
+static int interesting(git_pqueue *list)
+{
+	size_t i;
+
+	for (i = 0; i < git_pqueue_size(list); i++) {
+		git_commit_list_node *commit = git_pqueue_get(list, i);
+		if ((commit->flags & STALE) == 0)
+			return 1;
+	}
+
+	return 0;
+}
+
+static void clear_commit_marks_1(git_commit_list **plist,
+		git_commit_list_node *commit, unsigned int mark)
+{
+	while (commit) {
+		unsigned int i;
+
+		if (!(mark & commit->flags))
+			return;
+
+		commit->flags &= ~mark;
+
+		for (i = 1; i < commit->out_degree; i++) {
+			git_commit_list_node *p = commit->parents[i];
+			git_commit_list_insert(p, plist);
+		}
+
+		commit = commit->out_degree ? commit->parents[0] : NULL;
+	}
+}
+
+static void clear_commit_marks_many(git_vector *commits, unsigned int mark)
+{
+	git_commit_list *list = NULL;
+	git_commit_list_node *c;
+	unsigned int i;
+
+	git_vector_foreach(commits, i, c) {
+		git_commit_list_insert(c, &list);
+	}
+
+	while (list)
+		clear_commit_marks_1(&list, git_commit_list_pop(&list), mark);
+}
+
+static void clear_commit_marks(git_commit_list_node *commit, unsigned int mark)
+{
+	git_commit_list *list = NULL;
+	git_commit_list_insert(commit, &list);
+	while (list)
+		clear_commit_marks_1(&list, git_commit_list_pop(&list), mark);
+}
+
+static int paint_down_to_common(
+	git_commit_list **out, git_revwalk *walk, git_commit_list_node *one, git_vector *twos)
+{
+	git_pqueue list;
+	git_commit_list *result = NULL;
+	git_commit_list_node *two;
+
+	int error;
+	unsigned int i;
+
+	if (git_pqueue_init(&list, 0, twos->length * 2, git_commit_list_time_cmp) < 0)
+		return -1;
+
+	one->flags |= PARENT1;
+	if (git_pqueue_insert(&list, one) < 0)
+		return -1;
+
+	git_vector_foreach(twos, i, two) {
+		if (git_commit_list_parse(walk, two) < 0)
+			return -1;
+
+		two->flags |= PARENT2;
+
+		if (git_pqueue_insert(&list, two) < 0)
+			return -1;
+	}
+
+	/* as long as there are non-STALE commits */
+	while (interesting(&list)) {
+		git_commit_list_node *commit = git_pqueue_pop(&list);
+		int flags;
+
+		if (commit == NULL)
+			break;
+
+		flags = commit->flags & (PARENT1 | PARENT2 | STALE);
+		if (flags == (PARENT1 | PARENT2)) {
+			if (!(commit->flags & RESULT)) {
+				commit->flags |= RESULT;
+				if (git_commit_list_insert(commit, &result) == NULL)
+					return -1;
+			}
+			/* we mark the parents of a merge stale */
+			flags |= STALE;
+		}
+
+		for (i = 0; i < commit->out_degree; i++) {
+			git_commit_list_node *p = commit->parents[i];
+			if ((p->flags & flags) == flags)
+				continue;
+
+			if ((error = git_commit_list_parse(walk, p)) < 0)
+				return error;
+
+			p->flags |= flags;
+			if (git_pqueue_insert(&list, p) < 0)
+				return -1;
+		}
+	}
+
+	git_pqueue_free(&list);
+	*out = result;
+	return 0;
+}
+
+static int remove_redundant(git_revwalk *walk, git_vector *commits)
+{
+	git_vector work = GIT_VECTOR_INIT;
+	unsigned char *redundant;
+	unsigned int *filled_index;
+	unsigned int i, j;
+	int error = 0;
+
+	redundant = git__calloc(commits->length, 1);
+	GITERR_CHECK_ALLOC(redundant);
+	filled_index = git__calloc((commits->length - 1), sizeof(unsigned int));
+	GITERR_CHECK_ALLOC(filled_index);
+
+	for (i = 0; i < commits->length; ++i) {
+		if ((error = git_commit_list_parse(walk, commits->contents[i])) < 0)
+			goto done;
+	}
+
+	for (i = 0; i < commits->length; ++i) {
+		git_commit_list *common = NULL;
+		git_commit_list_node *commit = commits->contents[i];
+
+		if (redundant[i])
+			continue;
+
+		git_vector_clear(&work);
+
+		for (j = 0; j < commits->length; j++) {
+			if (i == j || redundant[j])
+				continue;
+
+			filled_index[work.length] = j;
+			if ((error = git_vector_insert(&work, commits->contents[j])) < 0)
+				goto done;
+		}
+
+		error = paint_down_to_common(&common, walk, commit, &work);
+		if (error < 0)
+			goto done;
+
+		if (commit->flags & PARENT2)
+			redundant[i] = 1;
+
+		for (j = 0; j < work.length; j++) {
+			git_commit_list_node *w = work.contents[j];
+			if (w->flags & PARENT1)
+				redundant[filled_index[j]] = 1;
+		}
+
+		clear_commit_marks(commit, ALL_FLAGS);
+		clear_commit_marks_many(&work, ALL_FLAGS);
+
+		git_commit_list_free(&common);
+	}
+
+	for (i = 0; i < commits->length; ++i) {
+		if (redundant[i])
+			commits->contents[i] = NULL;
+	}
+
+done:
+	git__free(redundant);
+	git__free(filled_index);
+	git_vector_free(&work);
+	return error;
+}
+
+int git_merge__bases_many(git_commit_list **out, git_revwalk *walk, git_commit_list_node *one, git_vector *twos)
+{
+	int error;
+	unsigned int i;
+	git_commit_list_node *two;
+	git_commit_list *result = NULL, *tmp = NULL;
+
+	/* If there's only the one commit, there can be no merge bases */
+	if (twos->length == 0) {
+		*out = NULL;
+		return 0;
+	}
+
+	/* if the commit is repeated, we have a our merge base already */
+	git_vector_foreach(twos, i, two) {
+		if (one == two)
+			return git_commit_list_insert(one, out) ? 0 : -1;
+	}
+
+	if (git_commit_list_parse(walk, one) < 0)
+		return -1;
+
+	error = paint_down_to_common(&result, walk, one, twos);
+	if (error < 0)
+		return error;
+
+	/* filter out any stale commits in the results */
+	tmp = result;
+	result = NULL;
+
+	while (tmp) {
+		git_commit_list_node *c = git_commit_list_pop(&tmp);
+		if (!(c->flags & STALE))
+			if (git_commit_list_insert_by_date(c, &result) == NULL)
+				return -1;
+	}
+
+	/*
+	 * more than one merge base -- see if there are redundant merge
+	 * bases and remove them
+	 */
+	if (result && result->next) {
+		git_vector redundant = GIT_VECTOR_INIT;
+
+		while (result)
+			git_vector_insert(&redundant, git_commit_list_pop(&result));
+
+		clear_commit_marks(one, ALL_FLAGS);
+		clear_commit_marks_many(twos, ALL_FLAGS);
+
+		if ((error = remove_redundant(walk, &redundant)) < 0) {
+			git_vector_free(&redundant);
+			return error;
+		}
+
+		git_vector_foreach(&redundant, i, two) {
+			if (two != NULL)
+				git_commit_list_insert_by_date(two, &result);
+		}
+
+		git_vector_free(&redundant);
+	}
+
+	*out = result;
+	return 0;
+}
+
+int git_repository_mergehead_foreach(
+	git_repository *repo,
+	git_repository_mergehead_foreach_cb cb,
+	void *payload)
+{
+	git_buf merge_head_path = GIT_BUF_INIT, merge_head_file = GIT_BUF_INIT;
+	char *buffer, *line;
+	size_t line_num = 1;
+	git_oid oid;
+	int error = 0;
+
+	assert(repo && cb);
+
+	if ((error = git_buf_joinpath(&merge_head_path, repo->gitdir,
+		GIT_MERGE_HEAD_FILE)) < 0)
+		return error;
+
+	if ((error = git_futils_readbuffer(&merge_head_file,
+		git_buf_cstr(&merge_head_path))) < 0)
+		goto cleanup;
+
+	buffer = merge_head_file.ptr;
+
+	while ((line = git__strsep(&buffer, "\n")) != NULL) {
+		if (strlen(line) != GIT_OID_HEXSZ) {
+			giterr_set(GITERR_INVALID, "unable to parse OID - invalid length");
+			error = -1;
+			goto cleanup;
+		}
+
+		if ((error = git_oid_fromstr(&oid, line)) < 0)
+			goto cleanup;
+
+		if ((error = cb(&oid, payload)) != 0) {
+			giterr_set_after_callback(error);
+			goto cleanup;
+		}
+
+		++line_num;
+	}
+
+	if (*buffer) {
+		giterr_set(GITERR_MERGE, "no EOL at line %"PRIuZ, line_num);
+		error = -1;
+		goto cleanup;
+	}
+
+cleanup:
+	git_buf_free(&merge_head_path);
+	git_buf_free(&merge_head_file);
+
+	return error;
+}
+
+GIT_INLINE(int) index_entry_cmp(const git_index_entry *a, const git_index_entry *b)
+{
+	int value = 0;
+
+	if (a->path == NULL)
+		return (b->path == NULL) ? 0 : 1;
+
+	if ((value = a->mode - b->mode) == 0 &&
+		(value = git_oid__cmp(&a->id, &b->id)) == 0)
+		value = strcmp(a->path, b->path);
+
+	return value;
+}
+
+/* Conflict resolution */
+
+static int merge_conflict_resolve_trivial(
+	int *resolved,
+	git_merge_diff_list *diff_list,
+	const git_merge_diff *conflict)
+{
+	int ours_empty, theirs_empty;
+	int ours_changed, theirs_changed, ours_theirs_differ;
+	git_index_entry const *result = NULL;
+	int error = 0;
+
+	assert(resolved && diff_list && conflict);
+
+	*resolved = 0;
+
+	if (conflict->type == GIT_MERGE_DIFF_DIRECTORY_FILE ||
+		conflict->type == GIT_MERGE_DIFF_RENAMED_ADDED)
+		return 0;
+
+	if (conflict->our_status == GIT_DELTA_RENAMED ||
+		conflict->their_status == GIT_DELTA_RENAMED)
+		return 0;
+
+	ours_empty = !GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->our_entry);
+	theirs_empty = !GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->their_entry);
+
+	ours_changed = (conflict->our_status != GIT_DELTA_UNMODIFIED);
+	theirs_changed = (conflict->their_status != GIT_DELTA_UNMODIFIED);
+	ours_theirs_differ = ours_changed && theirs_changed &&
+		index_entry_cmp(&conflict->our_entry, &conflict->their_entry);
+
+	/*
+	 * Note: with only one ancestor, some cases are not distinct:
+	 *
+	 * 16: ancest:anc1/anc2, head:anc1, remote:anc2 = result:no merge
+	 * 3: ancest:(empty)^, head:head, remote:(empty) = result:no merge
+	 * 2: ancest:(empty)^, head:(empty), remote:remote = result:no merge
+	 *
+	 * Note that the two cases that take D/F conflicts into account
+	 * specifically do not need to be explicitly tested, as D/F conflicts
+	 * would fail the *empty* test:
+	 *
+	 * 3ALT: ancest:(empty)+, head:head, remote:*empty* = result:head
+	 * 2ALT: ancest:(empty)+, head:*empty*, remote:remote = result:remote
+	 *
+	 * Note that many of these cases need not be explicitly tested, as
+	 * they simply degrade to "all different" cases (eg, 11):
+	 *
+	 * 4: ancest:(empty)^, head:head, remote:remote = result:no merge
+	 * 7: ancest:ancest+, head:(empty), remote:remote = result:no merge
+	 * 9: ancest:ancest+, head:head, remote:(empty) = result:no merge
+	 * 11: ancest:ancest+, head:head, remote:remote = result:no merge
+	 */
+
+	/* 5ALT: ancest:*, head:head, remote:head = result:head */
+	if (ours_changed && !ours_empty && !ours_theirs_differ)
+		result = &conflict->our_entry;
+	/* 6: ancest:ancest+, head:(empty), remote:(empty) = result:no merge */
+	else if (ours_changed && ours_empty && theirs_empty)
+		*resolved = 0;
+	/* 8: ancest:ancest^, head:(empty), remote:ancest = result:no merge */
+	else if (ours_empty && !theirs_changed)
+		*resolved = 0;
+	/* 10: ancest:ancest^, head:ancest, remote:(empty) = result:no merge */
+	else if (!ours_changed && theirs_empty)
+		*resolved = 0;
+	/* 13: ancest:ancest+, head:head, remote:ancest = result:head */
+	else if (ours_changed && !theirs_changed)
+		result = &conflict->our_entry;
+	/* 14: ancest:ancest+, head:ancest, remote:remote = result:remote */
+	else if (!ours_changed && theirs_changed)
+		result = &conflict->their_entry;
+	else
+		*resolved = 0;
+
+	if (result != NULL &&
+		GIT_MERGE_INDEX_ENTRY_EXISTS(*result) &&
+		(error = git_vector_insert(&diff_list->staged, (void *)result)) >= 0)
+		*resolved = 1;
+
+	/* Note: trivial resolution does not update the REUC. */
+
+	return error;
+}
+
+static int merge_conflict_resolve_one_removed(
+	int *resolved,
+	git_merge_diff_list *diff_list,
+	const git_merge_diff *conflict)
+{
+	int ours_empty, theirs_empty;
+	int ours_changed, theirs_changed;
+	int error = 0;
+
+	assert(resolved && diff_list && conflict);
+
+	*resolved = 0;
+
+	if (conflict->type == GIT_MERGE_DIFF_DIRECTORY_FILE ||
+		conflict->type == GIT_MERGE_DIFF_RENAMED_ADDED)
+		return 0;
+
+	ours_empty = !GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->our_entry);
+	theirs_empty = !GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->their_entry);
+
+	ours_changed = (conflict->our_status != GIT_DELTA_UNMODIFIED);
+	theirs_changed = (conflict->their_status != GIT_DELTA_UNMODIFIED);
+
+	/* Removed in both */
+	if (ours_changed && ours_empty && theirs_empty)
+		*resolved = 1;
+	/* Removed in ours */
+	else if (ours_empty && !theirs_changed)
+		*resolved = 1;
+	/* Removed in theirs */
+	else if (!ours_changed && theirs_empty)
+		*resolved = 1;
+
+	if (*resolved)
+		git_vector_insert(&diff_list->resolved, (git_merge_diff *)conflict);
+
+	return error;
+}
+
+static int merge_conflict_resolve_one_renamed(
+	int *resolved,
+	git_merge_diff_list *diff_list,
+	const git_merge_diff *conflict)
+{
+	int ours_renamed, theirs_renamed;
+	int ours_changed, theirs_changed;
+	git_index_entry *merged;
+	int error = 0;
+
+	assert(resolved && diff_list && conflict);
+
+	*resolved = 0;
+
+	if (!GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->our_entry) ||
+		!GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->their_entry))
+		return 0;
+
+	ours_renamed = (conflict->our_status == GIT_DELTA_RENAMED);
+	theirs_renamed = (conflict->their_status == GIT_DELTA_RENAMED);
+
+	if (!ours_renamed && !theirs_renamed)
+		return 0;
+
+	/* Reject one file in a 2->1 conflict */
+	if (conflict->type == GIT_MERGE_DIFF_BOTH_RENAMED_2_TO_1 ||
+		conflict->type == GIT_MERGE_DIFF_BOTH_RENAMED_1_TO_2 ||
+		conflict->type == GIT_MERGE_DIFF_RENAMED_ADDED)
+		return 0;
+
+	ours_changed = (git_oid__cmp(&conflict->ancestor_entry.id, &conflict->our_entry.id) != 0);
+	theirs_changed = (git_oid__cmp(&conflict->ancestor_entry.id, &conflict->their_entry.id) != 0);
+
+	/* if both are modified (and not to a common target) require a merge */
+	if (ours_changed && theirs_changed &&
+		git_oid__cmp(&conflict->our_entry.id, &conflict->their_entry.id) != 0)
+		return 0;
+
+	if ((merged = git_pool_malloc(&diff_list->pool, sizeof(git_index_entry))) == NULL)
+		return -1;
+
+	if (ours_changed)
+		memcpy(merged, &conflict->our_entry, sizeof(git_index_entry));
+	else
+		memcpy(merged, &conflict->their_entry, sizeof(git_index_entry));
+
+	if (ours_renamed)
+		merged->path = conflict->our_entry.path;
+	else
+		merged->path = conflict->their_entry.path;
+
+	*resolved = 1;
+
+	git_vector_insert(&diff_list->staged, merged);
+	git_vector_insert(&diff_list->resolved, (git_merge_diff *)conflict);
+
+	return error;
+}
+
+static bool merge_conflict_can_resolve_contents(
+	const git_merge_diff *conflict)
+{
+	if (!GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->our_entry) ||
+		!GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->their_entry))
+		return false;
+
+	/* Reject D/F conflicts */
+	if (conflict->type == GIT_MERGE_DIFF_DIRECTORY_FILE)
+		return false;
+
+	/* Reject submodules. */
+	if (S_ISGITLINK(conflict->ancestor_entry.mode) ||
+		S_ISGITLINK(conflict->our_entry.mode) ||
+		S_ISGITLINK(conflict->their_entry.mode))
+		return false;
+
+	/* Reject link/file conflicts. */
+	if ((S_ISLNK(conflict->ancestor_entry.mode) ^
+			S_ISLNK(conflict->our_entry.mode)) ||
+		(S_ISLNK(conflict->ancestor_entry.mode) ^
+			S_ISLNK(conflict->their_entry.mode)))
+		return false;
+
+	/* Reject name conflicts */
+	if (conflict->type == GIT_MERGE_DIFF_BOTH_RENAMED_2_TO_1 ||
+		conflict->type == GIT_MERGE_DIFF_RENAMED_ADDED)
+		return false;
+
+	if ((conflict->our_status & GIT_DELTA_RENAMED) == GIT_DELTA_RENAMED &&
+		(conflict->their_status & GIT_DELTA_RENAMED) == GIT_DELTA_RENAMED &&
+		strcmp(conflict->ancestor_entry.path, conflict->their_entry.path) != 0)
+		return false;
+
+	return true;
+}
+
+static int merge_conflict_invoke_driver(
+	git_index_entry **out,
+	const char *name,
+	git_merge_driver *driver,
+	git_merge_diff_list *diff_list,
+	git_merge_driver_source *src)
+{
+	git_index_entry *result;
+	git_buf buf = GIT_BUF_INIT;
+	const char *path;
+	uint32_t mode;
+	git_odb *odb = NULL;
+	git_oid oid;
+	int error;
+
+	*out = NULL;
+
+	if ((error = driver->apply(driver, &path, &mode, &buf, name, src)) < 0 ||
+		(error = git_repository_odb(&odb, src->repo)) < 0 ||
+		(error = git_odb_write(&oid, odb, buf.ptr, buf.size, GIT_OBJ_BLOB)) < 0)
+		goto done;
+
+	result = git_pool_mallocz(&diff_list->pool, sizeof(git_index_entry));
+	GITERR_CHECK_ALLOC(result);
+
+	git_oid_cpy(&result->id, &oid);
+	result->mode = mode;
+	result->file_size = buf.size;
+
+	result->path = git_pool_strdup(&diff_list->pool, path);
+	GITERR_CHECK_ALLOC(result->path);
+
+	*out = result;
+
+done:
+	git_buf_free(&buf);
+	git_odb_free(odb);
+
+	return error;
+}
+
+static int merge_conflict_resolve_contents(
+	int *resolved,
+	git_merge_diff_list *diff_list,
+	const git_merge_diff *conflict,
+	const git_merge_options *merge_opts,
+	const git_merge_file_options *file_opts)
+{
+	git_merge_driver_source source = {0};
+	git_merge_file_result result = {0};
+	git_merge_driver *driver;
+	git_merge_driver__builtin builtin = {{0}};
+	git_index_entry *merge_result;
+	git_odb *odb = NULL;
+	const char *name;
+	bool fallback = false;
+	int error;
+
+	assert(resolved && diff_list && conflict);
+
+	*resolved = 0;
+
+	if (!merge_conflict_can_resolve_contents(conflict))
+		return 0;
+
+	source.repo = diff_list->repo;
+	source.default_driver = merge_opts->default_driver;
+	source.file_opts = file_opts;
+	source.ancestor = GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->ancestor_entry) ?
+		&conflict->ancestor_entry : NULL;
+	source.ours = GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->our_entry) ?
+		&conflict->our_entry : NULL;
+	source.theirs = GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->their_entry) ?
+		&conflict->their_entry : NULL;
+
+	if (file_opts->favor != GIT_MERGE_FILE_FAVOR_NORMAL) {
+		/* if the user requested a particular type of resolution (via the
+		 * favor flag) then let that override the gitattributes and use
+		 * the builtin driver.
+		 */
+		name = "text";
+		builtin.base.apply = git_merge_driver__builtin_apply;
+		builtin.favor = file_opts->favor;
+
+		driver = &builtin.base;
+	} else {
+		/* find the merge driver for this file */
+		if ((error = git_merge_driver_for_source(&name, &driver, &source)) < 0)
+			goto done;
+
+		if (driver == NULL)
+			fallback = true;
+	}
+
+	if (driver) {
+		error = merge_conflict_invoke_driver(&merge_result, name, driver,
+			diff_list, &source);
+
+		if (error == GIT_PASSTHROUGH)
+			fallback = true;
+	}
+
+	if (fallback) {
+		error = merge_conflict_invoke_driver(&merge_result, "text",
+			&git_merge_driver__text.base, diff_list, &source);
+	}
+
+	if (error < 0) {
+		if (error == GIT_EMERGECONFLICT)
+			error = 0;
+
+		goto done;
+	}
+
+	git_vector_insert(&diff_list->staged, merge_result);
+	git_vector_insert(&diff_list->resolved, (git_merge_diff *)conflict);
+
+	*resolved = 1;
+
+done:
+	git_merge_file_result_free(&result);
+	git_odb_free(odb);
+
+	return error;
+}
+
+static int merge_conflict_resolve(
+	int *out,
+	git_merge_diff_list *diff_list,
+	const git_merge_diff *conflict,
+	const git_merge_options *merge_opts,
+	const git_merge_file_options *file_opts)
+{
+	int resolved = 0;
+	int error = 0;
+
+	*out = 0;
+
+	if ((error = merge_conflict_resolve_trivial(
+			&resolved, diff_list, conflict)) < 0)
+		goto done;
+
+	if (!resolved && (error = merge_conflict_resolve_one_removed(
+			&resolved, diff_list, conflict)) < 0)
+		goto done;
+
+	if (!resolved && (error = merge_conflict_resolve_one_renamed(
+			&resolved, diff_list, conflict)) < 0)
+		goto done;
+
+	if (!resolved && (error = merge_conflict_resolve_contents(
+			&resolved, diff_list, conflict, merge_opts, file_opts)) < 0)
+		goto done;
+
+	*out = resolved;
+
+done:
+	return error;
+}
+
+/* Rename detection and coalescing */
+
+struct merge_diff_similarity {
+	unsigned char similarity;
+	size_t other_idx;
+};
+
+static int index_entry_similarity_calc(
+	void **out,
+	git_repository *repo,
+	git_index_entry *entry,
+	const git_merge_options *opts)
+{
+	git_blob *blob;
+	git_diff_file diff_file = {{{0}}};
+	git_off_t blobsize;
+	int error;
+
+	*out = NULL;
+
+	if ((error = git_blob_lookup(&blob, repo, &entry->id)) < 0)
+		return error;
+
+	git_oid_cpy(&diff_file.id, &entry->id);
+	diff_file.path = entry->path;
+	diff_file.size = entry->file_size;
+	diff_file.mode = entry->mode;
+	diff_file.flags = 0;
+
+	blobsize = git_blob_rawsize(blob);
+
+	/* file too big for rename processing */
+	if (!git__is_sizet(blobsize))
+		return 0;
+
+	error = opts->metric->buffer_signature(out, &diff_file,
+		git_blob_rawcontent(blob), (size_t)blobsize,
+		opts->metric->payload);
+
+	git_blob_free(blob);
+
+	return error;
+}
+
+static int index_entry_similarity_inexact(
+	git_repository *repo,
+	git_index_entry *a,
+	size_t a_idx,
+	git_index_entry *b,
+	size_t b_idx,
+	void **cache,
+	const git_merge_options *opts)
+{
+	int score = 0;
+	int error = 0;
+
+	if (!GIT_MODE_ISBLOB(a->mode) || !GIT_MODE_ISBLOB(b->mode))
+		return 0;
+
+	/* update signature cache if needed */
+	if (!cache[a_idx] && (error = index_entry_similarity_calc(&cache[a_idx], repo, a, opts)) < 0)
+		return error;
+	if (!cache[b_idx] && (error = index_entry_similarity_calc(&cache[b_idx], repo, b, opts)) < 0)
+		return error;
+
+	/* some metrics may not wish to process this file (too big / too small) */
+	if (!cache[a_idx] || !cache[b_idx])
+		return 0;
+
+	/* compare signatures */
+	if (opts->metric->similarity(
+		&score, cache[a_idx], cache[b_idx], opts->metric->payload) < 0)
+		return -1;
+
+	/* clip score */
+	if (score < 0)
+		score = 0;
+	else if (score > 100)
+		score = 100;
+
+	return score;
+}
+
+/* Tracks deletes by oid for merge_diff_mark_similarity_exact().  This is a
+* non-shrinking queue where next_pos is the next position to dequeue. 
+*/
+typedef struct {
+	git_array_t(size_t) arr;
+	size_t next_pos;
+	size_t first_entry;
+} deletes_by_oid_queue;
+
+static void deletes_by_oid_free(git_oidmap *map) {
+	deletes_by_oid_queue *queue;
+
+	if (!map)
+		return;
+
+	git_oidmap_foreach_value(map, queue, {
+		git_array_clear(queue->arr);
+	});
+	git_oidmap_free(map);
+}
+
+static int deletes_by_oid_enqueue(git_oidmap *map, git_pool* pool, const git_oid *id, size_t idx) {
+	khint_t pos;
+	deletes_by_oid_queue *queue;
+	size_t *array_entry;
+	int error;
+
+	pos = git_oidmap_lookup_index(map, id);
+	if (!git_oidmap_valid_index(map, pos)) {
+		queue = git_pool_malloc(pool, sizeof(deletes_by_oid_queue));
+		GITERR_CHECK_ALLOC(queue);
+
+		git_array_init(queue->arr);
+		queue->next_pos = 0;
+		queue->first_entry = idx;
+
+		git_oidmap_insert(map, id, queue, &error);
+		if (error < 0)
+			return -1;
+	} else {
+		queue = git_oidmap_value_at(map, pos);
+		array_entry = git_array_alloc(queue->arr);
+		GITERR_CHECK_ALLOC(array_entry);
+		*array_entry = idx;
+	}
+
+	return 0;
+}
+
+static int deletes_by_oid_dequeue(size_t *idx, git_oidmap *map, const git_oid *id) {
+	khint_t pos;
+	deletes_by_oid_queue *queue;
+	size_t *array_entry;
+
+	pos = git_oidmap_lookup_index(map, id);
+
+	if (!git_oidmap_valid_index(map, pos))
+		return GIT_ENOTFOUND;
+
+	queue = git_oidmap_value_at(map, pos);
+	
+	if (queue->next_pos == 0) {
+		*idx = queue->first_entry;
+	} else {
+		array_entry = git_array_get(queue->arr, queue->next_pos - 1);
+		if (array_entry == NULL)
+			return GIT_ENOTFOUND;
+
+		*idx = *array_entry;
+	}
+
+	queue->next_pos++;
+	return 0;
+}
+
+static int merge_diff_mark_similarity_exact(
+	git_merge_diff_list *diff_list,
+	struct merge_diff_similarity *similarity_ours,
+	struct merge_diff_similarity *similarity_theirs)
+{
+	size_t i, j;
+	git_merge_diff *conflict_src, *conflict_tgt;
+	git_oidmap *ours_deletes_by_oid = NULL, *theirs_deletes_by_oid = NULL;
+	int error = 0;
+
+	if (!(ours_deletes_by_oid = git_oidmap_alloc()) ||
+		!(theirs_deletes_by_oid = git_oidmap_alloc())) {
+		error = -1;
+		goto done;
+	}
+
+	/* Build a map of object ids to conflicts */
+	git_vector_foreach(&diff_list->conflicts, i, conflict_src) {
+		/* Items can be the source of a rename iff they have an item in the
+		* ancestor slot and lack an item in the ours or theirs slot. */
+		if (!GIT_MERGE_INDEX_ENTRY_EXISTS(conflict_src->ancestor_entry))
+			continue;
+
+		if (!GIT_MERGE_INDEX_ENTRY_EXISTS(conflict_src->our_entry)) {
+			error = deletes_by_oid_enqueue(ours_deletes_by_oid, &diff_list->pool, &conflict_src->ancestor_entry.id, i);
+			if (error < 0)
+				goto done;
+		}
+
+		if (!GIT_MERGE_INDEX_ENTRY_EXISTS(conflict_src->their_entry)) {
+			error = deletes_by_oid_enqueue(theirs_deletes_by_oid, &diff_list->pool, &conflict_src->ancestor_entry.id, i);
+			if (error < 0)
+				goto done;
+		}
+	}
+
+	git_vector_foreach(&diff_list->conflicts, j, conflict_tgt) {
+		if (GIT_MERGE_INDEX_ENTRY_EXISTS(conflict_tgt->ancestor_entry))
+			continue;
+
+		if (GIT_MERGE_INDEX_ENTRY_EXISTS(conflict_tgt->our_entry)) {
+			if (deletes_by_oid_dequeue(&i, ours_deletes_by_oid, &conflict_tgt->our_entry.id) == 0) {
+				similarity_ours[i].similarity = 100;
+				similarity_ours[i].other_idx = j;
+
+				similarity_ours[j].similarity = 100;
+				similarity_ours[j].other_idx = i;
+			}
+		}
+
+		if (GIT_MERGE_INDEX_ENTRY_EXISTS(conflict_tgt->their_entry)) {
+			if (deletes_by_oid_dequeue(&i, theirs_deletes_by_oid, &conflict_tgt->their_entry.id) == 0) {
+				similarity_theirs[i].similarity = 100;
+				similarity_theirs[i].other_idx = j;
+
+				similarity_theirs[j].similarity = 100;
+				similarity_theirs[j].other_idx = i;
+			}
+		}
+	}
+
+done:
+	deletes_by_oid_free(ours_deletes_by_oid);
+	deletes_by_oid_free(theirs_deletes_by_oid);
+
+	return error;
+}
+
+static int merge_diff_mark_similarity_inexact(
+	git_repository *repo,
+	git_merge_diff_list *diff_list,
+	struct merge_diff_similarity *similarity_ours,
+	struct merge_diff_similarity *similarity_theirs,
+	void **cache,
+	const git_merge_options *opts)
+{
+	size_t i, j;
+	git_merge_diff *conflict_src, *conflict_tgt;
+	int similarity;
+
+	git_vector_foreach(&diff_list->conflicts, i, conflict_src) {
+		/* Items can be the source of a rename iff they have an item in the
+		 * ancestor slot and lack an item in the ours or theirs slot. */
+		if (!GIT_MERGE_INDEX_ENTRY_EXISTS(conflict_src->ancestor_entry) ||
+			(GIT_MERGE_INDEX_ENTRY_EXISTS(conflict_src->our_entry) &&
+			 GIT_MERGE_INDEX_ENTRY_EXISTS(conflict_src->their_entry)))
+			continue;
+
+		git_vector_foreach(&diff_list->conflicts, j, conflict_tgt) {
+			size_t our_idx = diff_list->conflicts.length + j;
+			size_t their_idx = (diff_list->conflicts.length * 2) + j;
+
+			if (GIT_MERGE_INDEX_ENTRY_EXISTS(conflict_tgt->ancestor_entry))
+				continue;
+
+			if (GIT_MERGE_INDEX_ENTRY_EXISTS(conflict_tgt->our_entry) &&
+				!GIT_MERGE_INDEX_ENTRY_EXISTS(conflict_src->our_entry)) {
+				similarity = index_entry_similarity_inexact(repo, &conflict_src->ancestor_entry, i, &conflict_tgt->our_entry, our_idx, cache, opts);
+
+				if (similarity == GIT_EBUFS)
+					continue;
+				else if (similarity < 0)
+					return similarity;
+
+				if (similarity > similarity_ours[i].similarity &&
+					similarity > similarity_ours[j].similarity) {
+					/* Clear previous best similarity */
+					if (similarity_ours[i].similarity > 0)
+						similarity_ours[similarity_ours[i].other_idx].similarity = 0;
+
+					if (similarity_ours[j].similarity > 0)
+						similarity_ours[similarity_ours[j].other_idx].similarity = 0;
+
+					similarity_ours[i].similarity = similarity;
+					similarity_ours[i].other_idx = j;
+
+					similarity_ours[j].similarity = similarity;
+					similarity_ours[j].other_idx = i;
+				}
+			}
+
+			if (GIT_MERGE_INDEX_ENTRY_EXISTS(conflict_tgt->their_entry) &&
+				!GIT_MERGE_INDEX_ENTRY_EXISTS(conflict_src->their_entry)) {
+				similarity = index_entry_similarity_inexact(repo, &conflict_src->ancestor_entry, i, &conflict_tgt->their_entry, their_idx, cache, opts);
+
+				if (similarity > similarity_theirs[i].similarity &&
+					similarity > similarity_theirs[j].similarity) {
+					/* Clear previous best similarity */
+					if (similarity_theirs[i].similarity > 0)
+						similarity_theirs[similarity_theirs[i].other_idx].similarity = 0;
+
+					if (similarity_theirs[j].similarity > 0)
+						similarity_theirs[similarity_theirs[j].other_idx].similarity = 0;
+
+					similarity_theirs[i].similarity = similarity;
+					similarity_theirs[i].other_idx = j;
+
+					similarity_theirs[j].similarity = similarity;
+					similarity_theirs[j].other_idx = i;
+				}
+			}
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Rename conflicts:
+ *
+ *      Ancestor   Ours   Theirs
+ *
+ * 0a   A          A      A        No rename
+ *  b   A          A*     A        No rename (ours was rewritten)
+ *  c   A          A      A*       No rename (theirs rewritten)
+ * 1a   A          A      B[A]     Rename or rename/edit
+ *  b   A          B[A]   A        (automergeable)
+ * 2    A          B[A]   B[A]     Both renamed (automergeable)
+ * 3a   A          B[A]            Rename/delete
+ *  b   A                 B[A]      (same)
+ * 4a   A          B[A]   B        Rename/add [B~ours B~theirs]
+ *  b   A          B      B[A]      (same)
+ * 5    A          B[A]   C[A]     Both renamed ("1 -> 2")
+ * 6    A          C[A]            Both renamed ("2 -> 1")
+ *      B                 C[B]     [C~ours C~theirs]    (automergeable)
+ */
+static void merge_diff_mark_rename_conflict(
+	git_merge_diff_list *diff_list,
+	struct merge_diff_similarity *similarity_ours,
+	bool ours_renamed,
+	size_t ours_source_idx,
+	struct merge_diff_similarity *similarity_theirs,
+	bool theirs_renamed,
+	size_t theirs_source_idx,
+	git_merge_diff *target,
+	const git_merge_options *opts)
+{
+	git_merge_diff *ours_source = NULL, *theirs_source = NULL;
+
+	if (ours_renamed)
+		ours_source = diff_list->conflicts.contents[ours_source_idx];
+
+	if (theirs_renamed)
+		theirs_source = diff_list->conflicts.contents[theirs_source_idx];
+
+	/* Detect 2->1 conflicts */
+	if (ours_renamed && theirs_renamed) {
+		/* Both renamed to the same target name. */
+		if (ours_source_idx == theirs_source_idx)
+			ours_source->type = GIT_MERGE_DIFF_BOTH_RENAMED;
+		else {
+			ours_source->type = GIT_MERGE_DIFF_BOTH_RENAMED_2_TO_1;
+			theirs_source->type = GIT_MERGE_DIFF_BOTH_RENAMED_2_TO_1;
+		}
+	} else if (ours_renamed) {
+		/* If our source was also renamed in theirs, this is a 1->2 */
+		if (similarity_theirs[ours_source_idx].similarity >= opts->rename_threshold)
+			ours_source->type = GIT_MERGE_DIFF_BOTH_RENAMED_1_TO_2;
+
+		else if (GIT_MERGE_INDEX_ENTRY_EXISTS(target->their_entry)) {
+			ours_source->type = GIT_MERGE_DIFF_RENAMED_ADDED;
+			target->type = GIT_MERGE_DIFF_RENAMED_ADDED;
+		}
+
+		else if (!GIT_MERGE_INDEX_ENTRY_EXISTS(ours_source->their_entry))
+			ours_source->type = GIT_MERGE_DIFF_RENAMED_DELETED;
+
+		else if (ours_source->type == GIT_MERGE_DIFF_MODIFIED_DELETED)
+			ours_source->type = GIT_MERGE_DIFF_RENAMED_MODIFIED;
+	} else if (theirs_renamed) {
+		/* If their source was also renamed in ours, this is a 1->2 */
+		if (similarity_ours[theirs_source_idx].similarity >= opts->rename_threshold)
+			theirs_source->type = GIT_MERGE_DIFF_BOTH_RENAMED_1_TO_2;
+
+		else if (GIT_MERGE_INDEX_ENTRY_EXISTS(target->our_entry)) {
+			theirs_source->type = GIT_MERGE_DIFF_RENAMED_ADDED;
+			target->type = GIT_MERGE_DIFF_RENAMED_ADDED;
+		}
+
+		else if (!GIT_MERGE_INDEX_ENTRY_EXISTS(theirs_source->our_entry))
+			theirs_source->type = GIT_MERGE_DIFF_RENAMED_DELETED;
+
+		else if (theirs_source->type == GIT_MERGE_DIFF_MODIFIED_DELETED)
+			theirs_source->type = GIT_MERGE_DIFF_RENAMED_MODIFIED;
+	}
+}
+
+GIT_INLINE(void) merge_diff_coalesce_rename(
+	git_index_entry *source_entry,
+	git_delta_t *source_status,
+	git_index_entry *target_entry,
+	git_delta_t *target_status)
+{
+	/* Coalesce the rename target into the rename source. */
+	memcpy(source_entry, target_entry, sizeof(git_index_entry));
+	*source_status = GIT_DELTA_RENAMED;
+
+	memset(target_entry, 0x0, sizeof(git_index_entry));
+	*target_status = GIT_DELTA_UNMODIFIED;
+}
+
+static void merge_diff_list_coalesce_renames(
+	git_merge_diff_list *diff_list,
+	struct merge_diff_similarity *similarity_ours,
+	struct merge_diff_similarity *similarity_theirs,
+	const git_merge_options *opts)
+{
+	size_t i;
+	bool ours_renamed = 0, theirs_renamed = 0;
+	size_t ours_source_idx = 0, theirs_source_idx = 0;
+	git_merge_diff *ours_source, *theirs_source, *target;
+
+	for (i = 0; i < diff_list->conflicts.length; i++) {
+		target = diff_list->conflicts.contents[i];
+
+		ours_renamed = 0;
+		theirs_renamed = 0;
+
+		if (GIT_MERGE_INDEX_ENTRY_EXISTS(target->our_entry) &&
+			similarity_ours[i].similarity >= opts->rename_threshold) {
+			ours_source_idx = similarity_ours[i].other_idx;
+
+			ours_source = diff_list->conflicts.contents[ours_source_idx];
+
+			merge_diff_coalesce_rename(
+				&ours_source->our_entry,
+				&ours_source->our_status,
+				&target->our_entry,
+				&target->our_status);
+
+			similarity_ours[ours_source_idx].similarity = 0;
+			similarity_ours[i].similarity = 0;
+
+			ours_renamed = 1;
+		}
+
+		/* insufficient to determine direction */
+		if (GIT_MERGE_INDEX_ENTRY_EXISTS(target->their_entry) &&
+			similarity_theirs[i].similarity >= opts->rename_threshold) {
+			theirs_source_idx = similarity_theirs[i].other_idx;
+
+			theirs_source = diff_list->conflicts.contents[theirs_source_idx];
+
+			merge_diff_coalesce_rename(
+				&theirs_source->their_entry,
+				&theirs_source->their_status,
+				&target->their_entry,
+				&target->their_status);
+
+			similarity_theirs[theirs_source_idx].similarity = 0;
+			similarity_theirs[i].similarity = 0;
+
+			theirs_renamed = 1;
+		}
+
+		merge_diff_mark_rename_conflict(diff_list,
+			similarity_ours, ours_renamed, ours_source_idx,
+			similarity_theirs, theirs_renamed, theirs_source_idx,
+			target, opts);
+	}
+}
+
+static int merge_diff_empty(const git_vector *conflicts, size_t idx, void *p)
+{
+	git_merge_diff *conflict = conflicts->contents[idx];
+
+	GIT_UNUSED(p);
+
+	return (!GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->ancestor_entry) &&
+		!GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->our_entry) &&
+		!GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->their_entry));
+}
+
+static void merge_diff_list_count_candidates(
+	git_merge_diff_list *diff_list,
+	size_t *src_count,
+	size_t *tgt_count)
+{
+	git_merge_diff *entry;
+	size_t i;
+
+	*src_count = 0;
+	*tgt_count = 0;
+
+	git_vector_foreach(&diff_list->conflicts, i, entry) {
+		if (GIT_MERGE_INDEX_ENTRY_EXISTS(entry->ancestor_entry) &&
+			(!GIT_MERGE_INDEX_ENTRY_EXISTS(entry->our_entry) ||
+			!GIT_MERGE_INDEX_ENTRY_EXISTS(entry->their_entry)))
+			(*src_count)++;
+		else if (!GIT_MERGE_INDEX_ENTRY_EXISTS(entry->ancestor_entry))
+			(*tgt_count)++;
+	}
+}
+
+int git_merge_diff_list__find_renames(
+	git_repository *repo,
+	git_merge_diff_list *diff_list,
+	const git_merge_options *opts)
+{
+	struct merge_diff_similarity *similarity_ours, *similarity_theirs;
+	void **cache = NULL;
+	size_t cache_size = 0;
+	size_t src_count, tgt_count, i;
+	int error = 0;
+
+	assert(diff_list && opts);
+
+	if ((opts->flags & GIT_MERGE_FIND_RENAMES) == 0)
+		return 0;
+
+	similarity_ours = git__calloc(diff_list->conflicts.length,
+		sizeof(struct merge_diff_similarity));
+	GITERR_CHECK_ALLOC(similarity_ours);
+
+	similarity_theirs = git__calloc(diff_list->conflicts.length,
+		sizeof(struct merge_diff_similarity));
+	GITERR_CHECK_ALLOC(similarity_theirs);
+
+	/* Calculate similarity between items that were deleted from the ancestor
+	 * and added in the other branch.
+	 */
+	if ((error = merge_diff_mark_similarity_exact(diff_list, similarity_ours, similarity_theirs)) < 0)
+		goto done;
+
+	if (opts->rename_threshold < 100 && diff_list->conflicts.length <= opts->target_limit) {
+		GITERR_CHECK_ALLOC_MULTIPLY(&cache_size, diff_list->conflicts.length, 3);
+		cache = git__calloc(cache_size, sizeof(void *));
+		GITERR_CHECK_ALLOC(cache);
+
+		merge_diff_list_count_candidates(diff_list, &src_count, &tgt_count);
+
+		if (src_count > opts->target_limit || tgt_count > opts->target_limit) {
+			/* TODO: report! */
+		} else {
+			if ((error = merge_diff_mark_similarity_inexact(
+				repo, diff_list, similarity_ours, similarity_theirs, cache, opts)) < 0)
+				goto done;
+		}
+	}
+
+	/* For entries that are appropriately similar, merge the new name's entry
+	 * into the old name.
+	 */
+	merge_diff_list_coalesce_renames(diff_list, similarity_ours, similarity_theirs, opts);
+
+	/* And remove any entries that were merged and are now empty. */
+	git_vector_remove_matching(&diff_list->conflicts, merge_diff_empty, NULL);
+
+done:
+	if (cache != NULL) {
+		for (i = 0; i < cache_size; ++i) {
+			if (cache[i] != NULL)
+				opts->metric->free_signature(cache[i], opts->metric->payload);
+		}
+
+		git__free(cache);
+	}
+
+	git__free(similarity_ours);
+	git__free(similarity_theirs);
+
+	return error;
+}
+
+/* Directory/file conflict handling */
+
+GIT_INLINE(const char *) merge_diff_path(
+	const git_merge_diff *conflict)
+{
+	if (GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->ancestor_entry))
+		return conflict->ancestor_entry.path;
+	else if (GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->our_entry))
+		return conflict->our_entry.path;
+	else if (GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->their_entry))
+		return conflict->their_entry.path;
+
+	return NULL;
+}
+
+GIT_INLINE(bool) merge_diff_any_side_added_or_modified(
+	const git_merge_diff *conflict)
+{
+	if (conflict->our_status == GIT_DELTA_ADDED ||
+		conflict->our_status == GIT_DELTA_MODIFIED ||
+		conflict->their_status == GIT_DELTA_ADDED ||
+		conflict->their_status == GIT_DELTA_MODIFIED)
+		return true;
+
+	return false;
+}
+
+GIT_INLINE(bool) path_is_prefixed(const char *parent, const char *child)
+{
+	size_t child_len = strlen(child);
+	size_t parent_len = strlen(parent);
+
+	if (child_len < parent_len ||
+		strncmp(parent, child, parent_len) != 0)
+		return 0;
+
+	return (child[parent_len] == '/');
+}
+
+GIT_INLINE(int) merge_diff_detect_df_conflict(
+	struct merge_diff_df_data *df_data,
+	git_merge_diff *conflict)
+{
+	const char *cur_path = merge_diff_path(conflict);
+
+	/* Determine if this is a D/F conflict or the child of one */
+	if (df_data->df_path &&
+		path_is_prefixed(df_data->df_path, cur_path))
+		conflict->type = GIT_MERGE_DIFF_DF_CHILD;
+	else if(df_data->df_path)
+		df_data->df_path = NULL;
+	else if (df_data->prev_path &&
+		merge_diff_any_side_added_or_modified(df_data->prev_conflict) &&
+		merge_diff_any_side_added_or_modified(conflict) &&
+		path_is_prefixed(df_data->prev_path, cur_path)) {
+		conflict->type = GIT_MERGE_DIFF_DF_CHILD;
+
+		df_data->prev_conflict->type = GIT_MERGE_DIFF_DIRECTORY_FILE;
+		df_data->df_path = df_data->prev_path;
+	}
+
+	df_data->prev_path = cur_path;
+	df_data->prev_conflict = conflict;
+
+	return 0;
+}
+
+/* Conflict handling */
+
+GIT_INLINE(int) merge_diff_detect_type(
+	git_merge_diff *conflict)
+{
+	if (conflict->our_status == GIT_DELTA_ADDED &&
+		conflict->their_status == GIT_DELTA_ADDED)
+		conflict->type = GIT_MERGE_DIFF_BOTH_ADDED;
+	else if (conflict->our_status == GIT_DELTA_MODIFIED &&
+			 conflict->their_status == GIT_DELTA_MODIFIED)
+		conflict->type = GIT_MERGE_DIFF_BOTH_MODIFIED;
+	else if (conflict->our_status == GIT_DELTA_DELETED &&
+			 conflict->their_status == GIT_DELTA_DELETED)
+		conflict->type = GIT_MERGE_DIFF_BOTH_DELETED;
+	else if (conflict->our_status == GIT_DELTA_MODIFIED &&
+			 conflict->their_status == GIT_DELTA_DELETED)
+		conflict->type = GIT_MERGE_DIFF_MODIFIED_DELETED;
+	else if (conflict->our_status == GIT_DELTA_DELETED &&
+			 conflict->their_status == GIT_DELTA_MODIFIED)
+		conflict->type = GIT_MERGE_DIFF_MODIFIED_DELETED;
+	else
+		conflict->type = GIT_MERGE_DIFF_NONE;
+
+	return 0;
+}
+
+GIT_INLINE(int) index_entry_dup_pool(
+	git_index_entry *out,
+	git_pool *pool,
+	const git_index_entry *src)
+{
+	if (src != NULL) {
+		memcpy(out, src, sizeof(git_index_entry));
+		if ((out->path = git_pool_strdup(pool, src->path)) == NULL)
+			return -1;
+	}
+
+	return 0;
+}
+
+GIT_INLINE(int) merge_delta_type_from_index_entries(
+	const git_index_entry *ancestor,
+	const git_index_entry *other)
+{
+	if (ancestor == NULL && other == NULL)
+		return GIT_DELTA_UNMODIFIED;
+	else if (ancestor == NULL && other != NULL)
+		return GIT_DELTA_ADDED;
+	else if (ancestor != NULL && other == NULL)
+		return GIT_DELTA_DELETED;
+	else if (S_ISDIR(ancestor->mode) ^ S_ISDIR(other->mode))
+		return GIT_DELTA_TYPECHANGE;
+	else if(S_ISLNK(ancestor->mode) ^ S_ISLNK(other->mode))
+		return GIT_DELTA_TYPECHANGE;
+	else if (git_oid__cmp(&ancestor->id, &other->id) ||
+			 ancestor->mode != other->mode)
+		return GIT_DELTA_MODIFIED;
+
+	return GIT_DELTA_UNMODIFIED;
+}
+
+static git_merge_diff *merge_diff_from_index_entries(
+	git_merge_diff_list *diff_list,
+	const git_index_entry **entries)
+{
+	git_merge_diff *conflict;
+	git_pool *pool = &diff_list->pool;
+
+	if ((conflict = git_pool_mallocz(pool, sizeof(git_merge_diff))) == NULL)
+		return NULL;
+
+	if (index_entry_dup_pool(&conflict->ancestor_entry, pool, entries[TREE_IDX_ANCESTOR]) < 0 ||
+		index_entry_dup_pool(&conflict->our_entry, pool, entries[TREE_IDX_OURS]) < 0 ||
+		index_entry_dup_pool(&conflict->their_entry, pool, entries[TREE_IDX_THEIRS]) < 0)
+		return NULL;
+
+	conflict->our_status = merge_delta_type_from_index_entries(
+		entries[TREE_IDX_ANCESTOR], entries[TREE_IDX_OURS]);
+	conflict->their_status = merge_delta_type_from_index_entries(
+		entries[TREE_IDX_ANCESTOR], entries[TREE_IDX_THEIRS]);
+
+	return conflict;
+}
+
+/* Merge trees */
+
+static int merge_diff_list_insert_conflict(
+	git_merge_diff_list *diff_list,
+	struct merge_diff_df_data *merge_df_data,
+	const git_index_entry *tree_items[3])
+{
+	git_merge_diff *conflict;
+
+	if ((conflict = merge_diff_from_index_entries(diff_list, tree_items)) == NULL ||
+		merge_diff_detect_type(conflict) < 0 ||
+		merge_diff_detect_df_conflict(merge_df_data, conflict) < 0 ||
+		git_vector_insert(&diff_list->conflicts, conflict) < 0)
+		return -1;
+
+	return 0;
+}
+
+static int merge_diff_list_insert_unmodified(
+	git_merge_diff_list *diff_list,
+	const git_index_entry *tree_items[3])
+{
+	int error = 0;
+	git_index_entry *entry;
+
+	entry = git_pool_malloc(&diff_list->pool, sizeof(git_index_entry));
+	GITERR_CHECK_ALLOC(entry);
+
+	if ((error = index_entry_dup_pool(entry, &diff_list->pool, tree_items[0])) >= 0)
+		error = git_vector_insert(&diff_list->staged, entry);
+
+	return error;
+}
+
+struct merge_diff_find_data {
+	git_merge_diff_list *diff_list;
+	struct merge_diff_df_data df_data;
+};
+
+static int queue_difference(const git_index_entry **entries, void *data)
+{
+	struct merge_diff_find_data *find_data = data;
+	bool item_modified = false;
+	size_t i;
+
+	if (!entries[0] || !entries[1] || !entries[2]) {
+		item_modified = true;
+	} else {
+		for (i = 1; i < 3; i++) {
+			if (index_entry_cmp(entries[0], entries[i]) != 0) {
+				item_modified = true;
+				break;
+			}
+		}
+	}
+
+	return item_modified ?
+		merge_diff_list_insert_conflict(
+			find_data->diff_list, &find_data->df_data, entries) :
+		merge_diff_list_insert_unmodified(find_data->diff_list, entries);
+}
+
+int git_merge_diff_list__find_differences(
+	git_merge_diff_list *diff_list,
+	git_iterator *ancestor_iter,
+	git_iterator *our_iter,
+	git_iterator *their_iter)
+{
+	git_iterator *iterators[3] = { ancestor_iter, our_iter, their_iter };
+	struct merge_diff_find_data find_data = { diff_list };
+
+	return git_iterator_walk(iterators, 3, queue_difference, &find_data);
+}
+
+git_merge_diff_list *git_merge_diff_list__alloc(git_repository *repo)
+{
+	git_merge_diff_list *diff_list = git__calloc(1, sizeof(git_merge_diff_list));
+
+	if (diff_list == NULL)
+		return NULL;
+
+	diff_list->repo = repo;
+
+	git_pool_init(&diff_list->pool, 1);
+
+	if (git_vector_init(&diff_list->staged, 0, NULL) < 0 ||
+		git_vector_init(&diff_list->conflicts, 0, NULL) < 0 ||
+		git_vector_init(&diff_list->resolved, 0, NULL) < 0) {
+		git_merge_diff_list__free(diff_list);
+		return NULL;
+	}
+
+	return diff_list;
+}
+
+void git_merge_diff_list__free(git_merge_diff_list *diff_list)
+{
+	if (!diff_list)
+		return;
+
+	git_vector_free(&diff_list->staged);
+	git_vector_free(&diff_list->conflicts);
+	git_vector_free(&diff_list->resolved);
+	git_pool_clear(&diff_list->pool);
+	git__free(diff_list);
+}
+
+static int merge_normalize_opts(
+	git_repository *repo,
+	git_merge_options *opts,
+	const git_merge_options *given)
+{
+	git_config *cfg = NULL;
+	git_config_entry *entry = NULL;
+	int error = 0;
+
+	assert(repo && opts);
+
+	if ((error = git_repository_config__weakptr(&cfg, repo)) < 0)
+		return error;
+
+	if (given != NULL) {
+		memcpy(opts, given, sizeof(git_merge_options));
+	} else {
+		git_merge_options init = GIT_MERGE_OPTIONS_INIT;
+		memcpy(opts, &init, sizeof(init));
+	}
+
+	if ((opts->flags & GIT_MERGE_FIND_RENAMES) && !opts->rename_threshold)
+		opts->rename_threshold = GIT_MERGE_DEFAULT_RENAME_THRESHOLD;
+
+	if (given && given->default_driver) {
+		opts->default_driver = git__strdup(given->default_driver);
+		GITERR_CHECK_ALLOC(opts->default_driver);
+	} else {
+		error = git_config_get_entry(&entry, cfg, "merge.default");
+
+		if (error == 0) {
+			opts->default_driver = git__strdup(entry->value);
+			GITERR_CHECK_ALLOC(opts->default_driver);
+		} else if (error == GIT_ENOTFOUND) {
+			error = 0;
+		} else {
+			goto done;
+		}
+	}
+
+	if (!opts->target_limit) {
+		int limit = git_config__get_int_force(cfg, "merge.renamelimit", 0);
+
+		if (!limit)
+			limit = git_config__get_int_force(cfg, "diff.renamelimit", 0);
+
+		opts->target_limit = (limit <= 0) ?
+			GIT_MERGE_DEFAULT_TARGET_LIMIT : (unsigned int)limit;
+	}
+
+	/* assign the internal metric with whitespace flag as payload */
+	if (!opts->metric) {
+		opts->metric = git__malloc(sizeof(git_diff_similarity_metric));
+		GITERR_CHECK_ALLOC(opts->metric);
+
+		opts->metric->file_signature = git_diff_find_similar__hashsig_for_file;
+		opts->metric->buffer_signature = git_diff_find_similar__hashsig_for_buf;
+		opts->metric->free_signature = git_diff_find_similar__hashsig_free;
+		opts->metric->similarity = git_diff_find_similar__calc_similarity;
+		opts->metric->payload = (void *)GIT_HASHSIG_SMART_WHITESPACE;
+	}
+
+done:
+	git_config_entry_free(entry);
+	return error;
+}
+
+
+static int merge_index_insert_reuc(
+	git_index *index,
+	size_t idx,
+	const git_index_entry *entry)
+{
+	const git_index_reuc_entry *reuc;
+	int mode[3] = { 0, 0, 0 };
+	git_oid const *oid[3] = { NULL, NULL, NULL };
+	size_t i;
+
+	if (!GIT_MERGE_INDEX_ENTRY_EXISTS(*entry))
+		return 0;
+
+	if ((reuc = git_index_reuc_get_bypath(index, entry->path)) != NULL) {
+		for (i = 0; i < 3; i++) {
+			mode[i] = reuc->mode[i];
+			oid[i] = &reuc->oid[i];
+		}
+	}
+
+	mode[idx] = entry->mode;
+	oid[idx] = &entry->id;
+
+	return git_index_reuc_add(index, entry->path,
+		mode[0], oid[0], mode[1], oid[1], mode[2], oid[2]);
+}
+
+static int index_update_reuc(git_index *index, git_merge_diff_list *diff_list)
+{
+	int error;
+	size_t i;
+	git_merge_diff *conflict;
+
+	/* Add each entry in the resolved conflict to the REUC independently, since
+	 * the paths may differ due to renames. */
+	git_vector_foreach(&diff_list->resolved, i, conflict) {
+		const git_index_entry *ancestor =
+			GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->ancestor_entry) ?
+			&conflict->ancestor_entry : NULL;
+
+		const git_index_entry *ours =
+			GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->our_entry) ?
+			&conflict->our_entry : NULL;
+
+		const git_index_entry *theirs =
+			GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->their_entry) ?
+			&conflict->their_entry : NULL;
+
+		if (ancestor != NULL &&
+			(error = merge_index_insert_reuc(index, TREE_IDX_ANCESTOR, ancestor)) < 0)
+			return error;
+
+		if (ours != NULL &&
+			(error = merge_index_insert_reuc(index, TREE_IDX_OURS, ours)) < 0)
+			return error;
+
+		if (theirs != NULL &&
+			(error = merge_index_insert_reuc(index, TREE_IDX_THEIRS, theirs)) < 0)
+			return error;
+	}
+
+	return 0;
+}
+
+static int index_from_diff_list(git_index **out,
+	git_merge_diff_list *diff_list, bool skip_reuc)
+{
+	git_index *index;
+	size_t i;
+	git_merge_diff *conflict;
+	int error = 0;
+
+	*out = NULL;
+
+	if ((error = git_index_new(&index)) < 0)
+		return error;
+
+	if ((error = git_index__fill(index, &diff_list->staged)) < 0)
+		goto on_error;
+
+	git_vector_foreach(&diff_list->conflicts, i, conflict) {
+		const git_index_entry *ancestor =
+			GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->ancestor_entry) ?
+			&conflict->ancestor_entry : NULL;
+
+		const git_index_entry *ours =
+			GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->our_entry) ?
+			&conflict->our_entry : NULL;
+
+		const git_index_entry *theirs =
+			GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->their_entry) ?
+			&conflict->their_entry : NULL;
+
+		if ((error = git_index_conflict_add(index, ancestor, ours, theirs)) < 0)
+			goto on_error;
+	}
+
+	/* Add each rename entry to the rename portion of the index. */
+	git_vector_foreach(&diff_list->conflicts, i, conflict) {
+		const char *ancestor_path, *our_path, *their_path;
+
+		if (!GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->ancestor_entry))
+			continue;
+
+		ancestor_path = conflict->ancestor_entry.path;
+
+		our_path =
+			GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->our_entry) ?
+			conflict->our_entry.path : NULL;
+
+		their_path =
+			GIT_MERGE_INDEX_ENTRY_EXISTS(conflict->their_entry) ?
+			conflict->their_entry.path : NULL;
+
+		if ((our_path && strcmp(ancestor_path, our_path) != 0) ||
+			(their_path && strcmp(ancestor_path, their_path) != 0)) {
+			if ((error = git_index_name_add(index, ancestor_path, our_path, their_path)) < 0)
+				goto on_error;
+		}
+	}
+
+	if (!skip_reuc) {
+		if ((error = index_update_reuc(index, diff_list)) < 0)
+			goto on_error;
+	}
+
+	*out = index;
+	return 0;
+
+on_error:
+	git_index_free(index);
+	return error;
+}
+
+static git_iterator *iterator_given_or_empty(git_iterator **empty, git_iterator *given)
+{
+	git_iterator_options opts = GIT_ITERATOR_OPTIONS_INIT;
+
+	if (given)
+		return given;
+
+	opts.flags = GIT_ITERATOR_DONT_IGNORE_CASE;
+
+	if (git_iterator_for_nothing(empty, &opts) < 0)
+		return NULL;
+
+	return *empty;
+}
+
+int git_merge__iterators(
+	git_index **out,
+	git_repository *repo,
+	git_iterator *ancestor_iter,
+	git_iterator *our_iter,
+	git_iterator *theirs_iter,
+	const git_merge_options *given_opts)
+{
+	git_iterator *empty_ancestor = NULL,
+		*empty_ours = NULL,
+		*empty_theirs = NULL;
+	git_merge_diff_list *diff_list;
+	git_merge_options opts;
+	git_merge_file_options file_opts = GIT_MERGE_FILE_OPTIONS_INIT;
+	git_merge_diff *conflict;
+	git_vector changes;
+	size_t i;
+	int error = 0;
+
+	assert(out && repo);
+
+	*out = NULL;
+
+	GITERR_CHECK_VERSION(
+		given_opts, GIT_MERGE_OPTIONS_VERSION, "git_merge_options");
+
+	if ((error = merge_normalize_opts(repo, &opts, given_opts)) < 0)
+		return error;
+
+	file_opts.favor = opts.file_favor;
+	file_opts.flags = opts.file_flags;
+
+	/* use the git-inspired labels when virtual base building */
+	if (opts.flags & GIT_MERGE__VIRTUAL_BASE) {
+		file_opts.ancestor_label = "merged common ancestors";
+		file_opts.our_label = "Temporary merge branch 1";
+		file_opts.their_label = "Temporary merge branch 2";
+		file_opts.flags |= GIT_MERGE_FILE_FAVOR__CONFLICTED;
+		file_opts.marker_size = GIT_MERGE_CONFLICT_MARKER_SIZE + 2;
+	}
+
+	diff_list = git_merge_diff_list__alloc(repo);
+	GITERR_CHECK_ALLOC(diff_list);
+
+	ancestor_iter = iterator_given_or_empty(&empty_ancestor, ancestor_iter);
+	our_iter = iterator_given_or_empty(&empty_ours, our_iter);
+	theirs_iter = iterator_given_or_empty(&empty_theirs, theirs_iter);
+
+	if ((error = git_merge_diff_list__find_differences(
+			diff_list, ancestor_iter, our_iter, theirs_iter)) < 0 ||
+		(error = git_merge_diff_list__find_renames(repo, diff_list, &opts)) < 0)
+		goto done;
+
+	memcpy(&changes, &diff_list->conflicts, sizeof(git_vector));
+	git_vector_clear(&diff_list->conflicts);
+
+	git_vector_foreach(&changes, i, conflict) {
+		int resolved = 0;
+
+		if ((error = merge_conflict_resolve(
+			&resolved, diff_list, conflict, &opts, &file_opts)) < 0)
+			goto done;
+
+		if (!resolved) {
+			if ((opts.flags & GIT_MERGE_FAIL_ON_CONFLICT)) {
+				giterr_set(GITERR_MERGE, "merge conflicts exist");
+				error = GIT_EMERGECONFLICT;
+				goto done;
+			}
+
+			git_vector_insert(&diff_list->conflicts, conflict);
+		}
+	}
+
+	error = index_from_diff_list(out, diff_list,
+		(opts.flags & GIT_MERGE_SKIP_REUC));
+
+done:
+	if (!given_opts || !given_opts->metric)
+		git__free(opts.metric);
+
+	git__free((char *)opts.default_driver);
+
+	git_merge_diff_list__free(diff_list);
+	git_iterator_free(empty_ancestor);
+	git_iterator_free(empty_ours);
+	git_iterator_free(empty_theirs);
+
+	return error;
+}
+
+int git_merge_trees(
+	git_index **out,
+	git_repository *repo,
+	const git_tree *ancestor_tree,
+	const git_tree *our_tree,
+	const git_tree *their_tree,
+	const git_merge_options *merge_opts)
+{
+	git_iterator *ancestor_iter = NULL, *our_iter = NULL, *their_iter = NULL;
+	git_iterator_options iter_opts = GIT_ITERATOR_OPTIONS_INIT;
+	int error;
+
+	assert(out && repo);
+
+	/* if one side is treesame to the ancestor, take the other side */
+	if (ancestor_tree && merge_opts && (merge_opts->flags & GIT_MERGE_SKIP_REUC)) {
+		const git_tree *result = NULL;
+		const git_oid *ancestor_tree_id = git_tree_id(ancestor_tree);
+
+		if (our_tree && !git_oid_cmp(ancestor_tree_id, git_tree_id(our_tree)))
+			result = their_tree;
+		else if (their_tree && !git_oid_cmp(ancestor_tree_id, git_tree_id(their_tree)))
+			result = our_tree;
+
+		if (result) {
+			if ((error = git_index_new(out)) == 0)
+    			error = git_index_read_tree(*out, result);
+
+			return error;
+		}
+	}
+
+	iter_opts.flags = GIT_ITERATOR_DONT_IGNORE_CASE;
+
+	if ((error = git_iterator_for_tree(
+			&ancestor_iter, (git_tree *)ancestor_tree, &iter_opts)) < 0 ||
+		(error = git_iterator_for_tree(
+			&our_iter, (git_tree *)our_tree, &iter_opts)) < 0 ||
+		(error = git_iterator_for_tree(
+			&their_iter, (git_tree *)their_tree, &iter_opts)) < 0)
+		goto done;
+
+	error = git_merge__iterators(
+		out, repo, ancestor_iter, our_iter, their_iter, merge_opts);
+
+done:
+	git_iterator_free(ancestor_iter);
+	git_iterator_free(our_iter);
+	git_iterator_free(their_iter);
+
+	return error;
+}
+
+static int merge_annotated_commits(
+	git_index **index_out,
+	git_annotated_commit **base_out,
+	git_repository *repo,
+	git_annotated_commit *our_commit,
+	git_annotated_commit *their_commit,
+	size_t recursion_level,
+	const git_merge_options *opts);
+
+GIT_INLINE(int) insert_head_ids(
+	git_array_oid_t *ids,
+	const git_annotated_commit *annotated_commit)
+{
+	git_oid *id;
+	size_t i;
+
+	if (annotated_commit->type == GIT_ANNOTATED_COMMIT_REAL) {
+		id = git_array_alloc(*ids);
+		GITERR_CHECK_ALLOC(id);
+
+		git_oid_cpy(id, git_commit_id(annotated_commit->commit));
+	} else {
+		for (i = 0; i < annotated_commit->parents.size; i++) {
+			id = git_array_alloc(*ids);
+			GITERR_CHECK_ALLOC(id);
+
+			git_oid_cpy(id, &annotated_commit->parents.ptr[i]);
+		}
+	}
+
+	return 0;
+}
+
+static int create_virtual_base(
+	git_annotated_commit **out,
+	git_repository *repo,
+	git_annotated_commit *one,
+	git_annotated_commit *two,
+	const git_merge_options *opts,
+	size_t recursion_level)
+{
+	git_annotated_commit *result = NULL;
+	git_index *index = NULL;
+	git_merge_options virtual_opts = GIT_MERGE_OPTIONS_INIT;
+
+	/* Conflicts in the merge base creation do not propagate to conflicts
+	 * in the result; the conflicted base will act as the common ancestor.
+	 */
+	if (opts)
+		memcpy(&virtual_opts, opts, sizeof(git_merge_options));
+
+	virtual_opts.flags &= ~GIT_MERGE_FAIL_ON_CONFLICT;
+	virtual_opts.flags |= GIT_MERGE__VIRTUAL_BASE;
+
+	if ((merge_annotated_commits(&index, NULL, repo, one, two,
+			recursion_level + 1, &virtual_opts)) < 0)
+		return -1;
+
+	result = git__calloc(1, sizeof(git_annotated_commit));
+	GITERR_CHECK_ALLOC(result);
+	result->type = GIT_ANNOTATED_COMMIT_VIRTUAL;
+	result->index = index;
+
+	insert_head_ids(&result->parents, one);
+	insert_head_ids(&result->parents, two);
+
+	*out = result;
+	return 0;
+}
+
+static int compute_base(
+	git_annotated_commit **out,
+	git_repository *repo,
+	const git_annotated_commit *one,
+	const git_annotated_commit *two,
+	const git_merge_options *given_opts,
+	size_t recursion_level)
+{
+	git_array_oid_t head_ids = GIT_ARRAY_INIT;
+	git_oidarray bases = {0};
+	git_annotated_commit *base = NULL, *other = NULL, *new_base = NULL;
+	git_merge_options opts = GIT_MERGE_OPTIONS_INIT;
+	size_t i, base_count;
+	int error;
+
+	*out = NULL;
+
+	if (given_opts)
+		memcpy(&opts, given_opts, sizeof(git_merge_options));
+
+	/* With more than two commits, merge_bases_many finds the base of
+	 * the first commit and a hypothetical merge of the others. Since
+	 * "one" may itself be a virtual commit, which insert_head_ids
+	 * substitutes multiple ancestors for, it needs to be added
+	 * after "two" which is always a single real commit.
+	 */
+	if ((error = insert_head_ids(&head_ids, two)) < 0 ||
+		(error = insert_head_ids(&head_ids, one)) < 0 ||
+		(error = git_merge_bases_many(&bases, repo,
+			head_ids.size, head_ids.ptr)) < 0)
+		goto done;
+
+	base_count = (opts.flags & GIT_MERGE_NO_RECURSIVE) ? 0 : bases.count;
+
+	if (base_count)
+		git_oidarray__reverse(&bases);
+
+	if ((error = git_annotated_commit_lookup(&base, repo, &bases.ids[0])) < 0)
+		goto done;
+
+	for (i = 1; i < base_count; i++) {
+		recursion_level++;
+
+		if (opts.recursion_limit && recursion_level > opts.recursion_limit)
+			break;
+
+		if ((error = git_annotated_commit_lookup(&other, repo,
+				&bases.ids[i])) < 0 ||
+			(error = create_virtual_base(&new_base, repo, base, other, &opts,
+				recursion_level)) < 0)
+			goto done;
+
+		git_annotated_commit_free(base);
+		git_annotated_commit_free(other);
+
+		base = new_base;
+		new_base = NULL;
+		other = NULL;
+	}
+
+done:
+	if (error == 0)
+		*out = base;
+	else
+		git_annotated_commit_free(base);
+
+	git_annotated_commit_free(other);
+	git_annotated_commit_free(new_base);
+	git_oidarray_free(&bases);
+	git_array_clear(head_ids);
+	return error;
+}
+
+static int iterator_for_annotated_commit(
+	git_iterator **out,
+	git_annotated_commit *commit)
+{
+	git_iterator_options opts = GIT_ITERATOR_OPTIONS_INIT;
+	int error;
+
+	opts.flags = GIT_ITERATOR_DONT_IGNORE_CASE;
+
+	if (commit == NULL) {
+		error = git_iterator_for_nothing(out, &opts);
+	} else if (commit->type == GIT_ANNOTATED_COMMIT_VIRTUAL) {
+		error = git_iterator_for_index(out, git_index_owner(commit->index), commit->index, &opts);
+	} else {
+		if (!commit->tree &&
+			(error = git_commit_tree(&commit->tree, commit->commit)) < 0)
+			goto done;
+
+		error = git_iterator_for_tree(out, commit->tree, &opts);
+	}
+
+done:
+	return error;
+}
+
+static int merge_annotated_commits(
+	git_index **index_out,
+	git_annotated_commit **base_out,
+	git_repository *repo,
+	git_annotated_commit *ours,
+	git_annotated_commit *theirs,
+	size_t recursion_level,
+	const git_merge_options *opts)
+{
+	git_annotated_commit *base = NULL;
+	git_iterator *base_iter = NULL, *our_iter = NULL, *their_iter = NULL;
+	int error;
+
+	if ((error = compute_base(&base, repo, ours, theirs, opts,
+		recursion_level)) < 0) {
+
+		if (error != GIT_ENOTFOUND)
+			goto done;
+
+		giterr_clear();
+	}
+
+	if ((error = iterator_for_annotated_commit(&base_iter, base)) < 0 ||
+		(error = iterator_for_annotated_commit(&our_iter, ours)) < 0 ||
+		(error = iterator_for_annotated_commit(&their_iter, theirs)) < 0 ||
+		(error = git_merge__iterators(index_out, repo, base_iter, our_iter,
+			their_iter, opts)) < 0)
+		goto done;
+
+	if (base_out) {
+		*base_out = base;
+		base = NULL;
+	}
+
+done:
+	git_annotated_commit_free(base);
+	git_iterator_free(base_iter);
+	git_iterator_free(our_iter);
+	git_iterator_free(their_iter);
+	return error;
+}
+
+
+int git_merge_commits(
+	git_index **out,
+	git_repository *repo,
+	const git_commit *our_commit,
+	const git_commit *their_commit,
+	const git_merge_options *opts)
+{
+	git_annotated_commit *ours = NULL, *theirs = NULL, *base = NULL;
+	int error = 0;
+
+	if ((error = git_annotated_commit_from_commit(&ours, (git_commit *)our_commit)) < 0 ||
+		(error = git_annotated_commit_from_commit(&theirs, (git_commit *)their_commit)) < 0)
+		goto done;
+
+	error = merge_annotated_commits(out, &base, repo, ours, theirs, 0, opts);
+
+done:
+	git_annotated_commit_free(ours);
+	git_annotated_commit_free(theirs);
+	git_annotated_commit_free(base);
+	return error;
+}
+
+/* Merge setup / cleanup */
+
+static int write_merge_head(
+	git_repository *repo,
+	const git_annotated_commit *heads[],
+	size_t heads_len)
+{
+	git_filebuf file = GIT_FILEBUF_INIT;
+	git_buf file_path = GIT_BUF_INIT;
+	size_t i;
+	int error = 0;
+
+	assert(repo && heads);
+
+	if ((error = git_buf_joinpath(&file_path, repo->gitdir, GIT_MERGE_HEAD_FILE)) < 0 ||
+		(error = git_filebuf_open(&file, file_path.ptr, GIT_FILEBUF_FORCE, GIT_MERGE_FILE_MODE)) < 0)
+		goto cleanup;
+
+	for (i = 0; i < heads_len; i++) {
+		if ((error = git_filebuf_printf(&file, "%s\n", heads[i]->id_str)) < 0)
+			goto cleanup;
+	}
+
+	error = git_filebuf_commit(&file);
+
+cleanup:
+	if (error < 0)
+		git_filebuf_cleanup(&file);
+
+	git_buf_free(&file_path);
+
+	return error;
+}
+
+static int write_merge_mode(git_repository *repo)
+{
+	git_filebuf file = GIT_FILEBUF_INIT;
+	git_buf file_path = GIT_BUF_INIT;
+	int error = 0;
+
+	assert(repo);
+
+	if ((error = git_buf_joinpath(&file_path, repo->gitdir, GIT_MERGE_MODE_FILE)) < 0 ||
+		(error = git_filebuf_open(&file, file_path.ptr, GIT_FILEBUF_FORCE, GIT_MERGE_FILE_MODE)) < 0)
+		goto cleanup;
+
+	if ((error = git_filebuf_write(&file, "no-ff", 5)) < 0)
+		goto cleanup;
+
+	error = git_filebuf_commit(&file);
+
+cleanup:
+	if (error < 0)
+		git_filebuf_cleanup(&file);
+
+	git_buf_free(&file_path);
+
+	return error;
+}
+
+struct merge_msg_entry {
+	const git_annotated_commit *merge_head;
+	bool written;
+};
+
+static int msg_entry_is_branch(
+	const struct merge_msg_entry *entry,
+	git_vector *entries)
+{
+	GIT_UNUSED(entries);
+
+	return (entry->written == 0 &&
+		entry->merge_head->remote_url == NULL &&
+		entry->merge_head->ref_name != NULL &&
+		git__strncmp(GIT_REFS_HEADS_DIR, entry->merge_head->ref_name, strlen(GIT_REFS_HEADS_DIR)) == 0);
+}
+
+static int msg_entry_is_tracking(
+	const struct merge_msg_entry *entry,
+	git_vector *entries)
+{
+	GIT_UNUSED(entries);
+
+	return (entry->written == 0 &&
+		entry->merge_head->remote_url == NULL &&
+		entry->merge_head->ref_name != NULL &&
+		git__strncmp(GIT_REFS_REMOTES_DIR, entry->merge_head->ref_name, strlen(GIT_REFS_REMOTES_DIR)) == 0);
+}
+
+static int msg_entry_is_tag(
+	const struct merge_msg_entry *entry,
+	git_vector *entries)
+{
+	GIT_UNUSED(entries);
+
+	return (entry->written == 0 &&
+		entry->merge_head->remote_url == NULL &&
+		entry->merge_head->ref_name != NULL &&
+		git__strncmp(GIT_REFS_TAGS_DIR, entry->merge_head->ref_name, strlen(GIT_REFS_TAGS_DIR)) == 0);
+}
+
+static int msg_entry_is_remote(
+	const struct merge_msg_entry *entry,
+	git_vector *entries)
+{
+	if (entry->written == 0 &&
+		entry->merge_head->remote_url != NULL &&
+		entry->merge_head->ref_name != NULL &&
+		git__strncmp(GIT_REFS_HEADS_DIR, entry->merge_head->ref_name, strlen(GIT_REFS_HEADS_DIR)) == 0)
+	{
+		struct merge_msg_entry *existing;
+
+		/* Match only branches from the same remote */
+		if (entries->length == 0)
+			return 1;
+
+		existing = git_vector_get(entries, 0);
+
+		return (git__strcmp(existing->merge_head->remote_url,
+			entry->merge_head->remote_url) == 0);
+	}
+
+	return 0;
+}
+
+static int msg_entry_is_oid(
+	const struct merge_msg_entry *merge_msg_entry)
+{
+	return (merge_msg_entry->written == 0 &&
+		merge_msg_entry->merge_head->ref_name == NULL &&
+		merge_msg_entry->merge_head->remote_url == NULL);
+}
+
+static int merge_msg_entry_written(
+	const struct merge_msg_entry *merge_msg_entry)
+{
+	return (merge_msg_entry->written == 1);
+}
+
+static int merge_msg_entries(
+	git_vector *v,
+	const struct merge_msg_entry *entries,
+	size_t len,
+	int (*match)(const struct merge_msg_entry *entry, git_vector *entries))
+{
+	size_t i;
+	int matches, total = 0;
+
+	git_vector_clear(v);
+
+	for (i = 0; i < len; i++) {
+		if ((matches = match(&entries[i], v)) < 0)
+			return matches;
+		else if (!matches)
+			continue;
+
+		git_vector_insert(v, (struct merge_msg_entry *)&entries[i]);
+		total++;
+	}
+
+	return total;
+}
+
+static int merge_msg_write_entries(
+	git_filebuf *file,
+	git_vector *entries,
+	const char *item_name,
+	const char *item_plural_name,
+	size_t ref_name_skip,
+	const char *source,
+	char sep)
+{
+	struct merge_msg_entry *entry;
+	size_t i;
+	int error = 0;
+
+	if (entries->length == 0)
+		return 0;
+
+	if (sep && (error = git_filebuf_printf(file, "%c ", sep)) < 0)
+		goto done;
+
+	if ((error = git_filebuf_printf(file, "%s ",
+		(entries->length == 1) ? item_name : item_plural_name)) < 0)
+		goto done;
+
+	git_vector_foreach(entries, i, entry) {
+		if (i > 0 &&
+			(error = git_filebuf_printf(file, "%s", (i == entries->length - 1) ? " and " : ", ")) < 0)
+			goto done;
+
+		if ((error = git_filebuf_printf(file, "'%s'", entry->merge_head->ref_name + ref_name_skip)) < 0)
+			goto done;
+
+		entry->written = 1;
+	}
+
+	if (source)
+		error = git_filebuf_printf(file, " of %s", source);
+
+done:
+	return error;
+}
+
+static int merge_msg_write_branches(
+	git_filebuf *file,
+	git_vector *entries,
+	char sep)
+{
+	return merge_msg_write_entries(file, entries,
+		"branch", "branches", strlen(GIT_REFS_HEADS_DIR), NULL, sep);
+}
+
+static int merge_msg_write_tracking(
+	git_filebuf *file,
+	git_vector *entries,
+	char sep)
+{
+	return merge_msg_write_entries(file, entries,
+		"remote-tracking branch", "remote-tracking branches", 0, NULL, sep);
+}
+
+static int merge_msg_write_tags(
+	git_filebuf *file,
+	git_vector *entries,
+	char sep)
+{
+	return merge_msg_write_entries(file, entries,
+		"tag", "tags", strlen(GIT_REFS_TAGS_DIR), NULL, sep);
+}
+
+static int merge_msg_write_remotes(
+	git_filebuf *file,
+	git_vector *entries,
+	char sep)
+{
+	const char *source;
+
+	if (entries->length == 0)
+		return 0;
+
+	source = ((struct merge_msg_entry *)entries->contents[0])->merge_head->remote_url;
+
+	return merge_msg_write_entries(file, entries,
+		"branch", "branches", strlen(GIT_REFS_HEADS_DIR), source, sep);
+}
+
+static int write_merge_msg(
+	git_repository *repo,
+	const git_annotated_commit *heads[],
+	size_t heads_len)
+{
+	git_filebuf file = GIT_FILEBUF_INIT;
+	git_buf file_path = GIT_BUF_INIT;
+	struct merge_msg_entry *entries;
+	git_vector matching = GIT_VECTOR_INIT;
+	size_t i;
+	char sep = 0;
+	int error = 0;
+
+	assert(repo && heads);
+
+	entries = git__calloc(heads_len, sizeof(struct merge_msg_entry));
+	GITERR_CHECK_ALLOC(entries);
+
+	if (git_vector_init(&matching, heads_len, NULL) < 0) {
+		git__free(entries);
+		return -1;
+	}
+
+	for (i = 0; i < heads_len; i++)
+		entries[i].merge_head = heads[i];
+
+	if ((error = git_buf_joinpath(&file_path, repo->gitdir, GIT_MERGE_MSG_FILE)) < 0 ||
+		(error = git_filebuf_open(&file, file_path.ptr, GIT_FILEBUF_FORCE, GIT_MERGE_FILE_MODE)) < 0 ||
+		(error = git_filebuf_write(&file, "Merge ", 6)) < 0)
+		goto cleanup;
+
+	/*
+	 * This is to emulate the format of MERGE_MSG by core git.
+	 *
+	 * Core git will write all the commits specified by OID, in the order
+	 * provided, until the first named branch or tag is reached, at which
+	 * point all branches will be written in the order provided, then all
+	 * tags, then all remote tracking branches and finally all commits that
+	 * were specified by OID that were not already written.
+	 *
+	 * Yes.  Really.
+	 */
+	for (i = 0; i < heads_len; i++) {
+		if (!msg_entry_is_oid(&entries[i]))
+			break;
+
+		if ((error = git_filebuf_printf(&file,
+			"%scommit '%s'", (i > 0) ? "; " : "",
+			entries[i].merge_head->id_str)) < 0)
+			goto cleanup;
+
+		entries[i].written = 1;
+	}
+
+	if (i)
+		sep = ';';
+
+	if ((error = merge_msg_entries(&matching, entries, heads_len, msg_entry_is_branch)) < 0 ||
+		(error = merge_msg_write_branches(&file, &matching, sep)) < 0)
+		goto cleanup;
+
+	if (matching.length)
+		sep =',';
+
+	if ((error = merge_msg_entries(&matching, entries, heads_len, msg_entry_is_tracking)) < 0 ||
+		(error = merge_msg_write_tracking(&file, &matching, sep)) < 0)
+		goto cleanup;
+
+	if (matching.length)
+		sep =',';
+
+	if ((error = merge_msg_entries(&matching, entries, heads_len, msg_entry_is_tag)) < 0 ||
+		(error = merge_msg_write_tags(&file, &matching, sep)) < 0)
+		goto cleanup;
+
+	if (matching.length)
+		sep =',';
+
+	/* We should never be called with multiple remote branches, but handle
+	 * it in case we are... */
+	while ((error = merge_msg_entries(&matching, entries, heads_len, msg_entry_is_remote)) > 0) {
+		if ((error = merge_msg_write_remotes(&file, &matching, sep)) < 0)
+			goto cleanup;
+
+		if (matching.length)
+			sep =',';
+	}
+
+	if (error < 0)
+		goto cleanup;
+
+	for (i = 0; i < heads_len; i++) {
+		if (merge_msg_entry_written(&entries[i]))
+			continue;
+
+		if ((error = git_filebuf_printf(&file, "; commit '%s'",
+			entries[i].merge_head->id_str)) < 0)
+			goto cleanup;
+	}
+
+	if ((error = git_filebuf_printf(&file, "\n")) < 0 ||
+		(error = git_filebuf_commit(&file)) < 0)
+		goto cleanup;
+
+cleanup:
+	if (error < 0)
+		git_filebuf_cleanup(&file);
+
+	git_buf_free(&file_path);
+
+	git_vector_free(&matching);
+	git__free(entries);
+
+	return error;
+}
+
+int git_merge__setup(
+	git_repository *repo,
+	const git_annotated_commit *our_head,
+	const git_annotated_commit *heads[],
+	size_t heads_len)
+{
+	int error = 0;
+
+	assert (repo && our_head && heads);
+
+	if ((error = git_repository__set_orig_head(repo, git_annotated_commit_id(our_head))) == 0 &&
+		(error = write_merge_head(repo, heads, heads_len)) == 0 &&
+		(error = write_merge_mode(repo)) == 0) {
+		error = write_merge_msg(repo, heads, heads_len);
+	}
+
+	return error;
+}
+
+/* Merge branches */
+
+static int merge_ancestor_head(
+	git_annotated_commit **ancestor_head,
+	git_repository *repo,
+	const git_annotated_commit *our_head,
+	const git_annotated_commit **their_heads,
+	size_t their_heads_len)
+{
+	git_oid *oids, ancestor_oid;
+	size_t i, alloc_len;
+	int error = 0;
+
+	assert(repo && our_head && their_heads);
+
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, their_heads_len, 1);
+	oids = git__calloc(alloc_len, sizeof(git_oid));
+	GITERR_CHECK_ALLOC(oids);
+
+	git_oid_cpy(&oids[0], git_commit_id(our_head->commit));
+
+	for (i = 0; i < their_heads_len; i++)
+		git_oid_cpy(&oids[i + 1], git_annotated_commit_id(their_heads[i]));
+
+	if ((error = git_merge_base_many(&ancestor_oid, repo, their_heads_len + 1, oids)) < 0)
+		goto on_error;
+
+	error = git_annotated_commit_lookup(ancestor_head, repo, &ancestor_oid);
+
+on_error:
+	git__free(oids);
+	return error;
+}
+
+const char *merge_their_label(const char *branchname)
+{
+	const char *slash;
+
+	if ((slash = strrchr(branchname, '/')) == NULL)
+		return branchname;
+
+	if (*(slash+1) == '\0')
+		return "theirs";
+
+	return slash+1;
+}
+
+static int merge_normalize_checkout_opts(
+	git_checkout_options *out,
+	git_repository *repo,
+	const git_checkout_options *given_checkout_opts,
+	unsigned int checkout_strategy,
+	git_annotated_commit *ancestor,
+	const git_annotated_commit *our_head,
+	const git_annotated_commit **their_heads,
+	size_t their_heads_len)
+{
+	git_checkout_options default_checkout_opts = GIT_CHECKOUT_OPTIONS_INIT;
+	int error = 0;
+
+	GIT_UNUSED(repo);
+
+	if (given_checkout_opts != NULL)
+		memcpy(out, given_checkout_opts, sizeof(git_checkout_options));
+	else
+		memcpy(out, &default_checkout_opts, sizeof(git_checkout_options));
+
+	out->checkout_strategy = checkout_strategy;
+
+	if (!out->ancestor_label) {
+		if (ancestor && ancestor->type == GIT_ANNOTATED_COMMIT_REAL)
+			out->ancestor_label = git_commit_summary(ancestor->commit);
+		else if (ancestor)
+			out->ancestor_label = "merged common ancestors";
+		else
+			out->ancestor_label = "empty base";
+	}
+
+	if (!out->our_label) {
+		if (our_head && our_head->ref_name)
+			out->our_label = our_head->ref_name;
+		else
+			out->our_label = "ours";
+	}
+
+	if (!out->their_label) {
+		if (their_heads_len == 1 && their_heads[0]->ref_name)
+			out->their_label = merge_their_label(their_heads[0]->ref_name);
+		else if (their_heads_len == 1)
+			out->their_label = their_heads[0]->id_str;
+		else
+			out->their_label = "theirs";
+	}
+
+	return error;
+}
+
+static int merge_check_index(size_t *conflicts, git_repository *repo, git_index *index_new, git_vector *merged_paths)
+{
+	git_tree *head_tree = NULL;
+	git_index *index_repo = NULL;
+	git_iterator *iter_repo = NULL, *iter_new = NULL;
+	git_iterator_options iter_opts = GIT_ITERATOR_OPTIONS_INIT;
+	git_diff *staged_diff_list = NULL, *index_diff_list = NULL;
+	git_diff_delta *delta;
+	git_diff_options opts = GIT_DIFF_OPTIONS_INIT;
+	git_vector staged_paths = GIT_VECTOR_INIT;
+	size_t i;
+	int error = 0;
+
+	GIT_UNUSED(merged_paths);
+
+	*conflicts = 0;
+
+	/* No staged changes may exist unless the change staged is identical to
+	 * the result of the merge.  This allows one to apply to merge manually,
+	 * then run merge.  Any other staged change would be overwritten by
+	 * a reset merge.
+	 */
+	if ((error = git_repository_head_tree(&head_tree, repo)) < 0 ||
+		(error = git_repository_index(&index_repo, repo)) < 0 ||
+		(error = git_diff_tree_to_index(&staged_diff_list, repo, head_tree, index_repo, &opts)) < 0)
+		goto done;
+
+	if (staged_diff_list->deltas.length == 0)
+		goto done;
+
+	git_vector_foreach(&staged_diff_list->deltas, i, delta) {
+		if ((error = git_vector_insert(&staged_paths, (char *)delta->new_file.path)) < 0)
+			goto done;
+	}
+
+	iter_opts.flags = GIT_ITERATOR_DONT_IGNORE_CASE;
+	iter_opts.pathlist.strings = (char **)staged_paths.contents;
+	iter_opts.pathlist.count = staged_paths.length;
+
+	if ((error = git_iterator_for_index(&iter_repo, repo, index_repo, &iter_opts)) < 0 ||
+		(error = git_iterator_for_index(&iter_new, repo, index_new, &iter_opts)) < 0 ||
+		(error = git_diff__from_iterators(&index_diff_list, repo, iter_repo, iter_new, &opts)) < 0)
+		goto done;
+
+	*conflicts = index_diff_list->deltas.length;
+
+done:
+	git_tree_free(head_tree);
+	git_index_free(index_repo);
+	git_iterator_free(iter_repo);
+	git_iterator_free(iter_new);
+	git_diff_free(staged_diff_list);
+	git_diff_free(index_diff_list);
+	git_vector_free(&staged_paths);
+
+	return error;
+}
+
+static int merge_check_workdir(size_t *conflicts, git_repository *repo, git_index *index_new, git_vector *merged_paths)
+{
+	git_diff *wd_diff_list = NULL;
+	git_diff_options opts = GIT_DIFF_OPTIONS_INIT;
+	int error = 0;
+
+	GIT_UNUSED(index_new);
+
+	*conflicts = 0;
+
+	/* We need to have merged at least 1 file for the possibility to exist to
+	 * have conflicts with the workdir. Passing 0 as the pathspec count paramter
+	 * will consider all files in the working directory, that is, we may detect
+	 * a conflict if there were untracked files in the workdir prior to starting
+	 * the merge. This typically happens when cherry-picking a commmit whose
+	 * changes have already been applied.
+	 */
+	if (merged_paths->length == 0)
+		return 0;
+
+	opts.flags |= GIT_DIFF_INCLUDE_UNTRACKED;
+
+	/* Workdir changes may exist iff they do not conflict with changes that
+	 * will be applied by the merge (including conflicts).  Ensure that there
+	 * are no changes in the workdir to these paths.
+	 */
+	opts.flags |= GIT_DIFF_DISABLE_PATHSPEC_MATCH;
+	opts.pathspec.count = merged_paths->length;
+	opts.pathspec.strings = (char **)merged_paths->contents;
+	opts.ignore_submodules = GIT_SUBMODULE_IGNORE_ALL;
+
+	if ((error = git_diff_index_to_workdir(&wd_diff_list, repo, NULL, &opts)) < 0)
+		goto done;
+
+	*conflicts = wd_diff_list->deltas.length;
+
+done:
+	git_diff_free(wd_diff_list);
+
+	return error;
+}
+
+int git_merge__check_result(git_repository *repo, git_index *index_new)
+{
+	git_tree *head_tree = NULL;
+	git_iterator *iter_head = NULL, *iter_new = NULL;
+	git_iterator_options iter_opts = GIT_ITERATOR_OPTIONS_INIT;
+	git_diff *merged_list = NULL;
+	git_diff_options opts = GIT_DIFF_OPTIONS_INIT;
+	git_diff_delta *delta;
+	git_vector paths = GIT_VECTOR_INIT;
+	size_t i, index_conflicts = 0, wd_conflicts = 0, conflicts;
+	const git_index_entry *e;
+	int error = 0;
+
+	iter_opts.flags = GIT_ITERATOR_DONT_IGNORE_CASE;
+
+	if ((error = git_repository_head_tree(&head_tree, repo)) < 0 ||
+		(error = git_iterator_for_tree(&iter_head, head_tree, &iter_opts)) < 0 ||
+		(error = git_iterator_for_index(&iter_new, repo, index_new, &iter_opts)) < 0 ||
+		(error = git_diff__from_iterators(&merged_list, repo, iter_head, iter_new, &opts)) < 0)
+		goto done;
+
+	git_vector_foreach(&merged_list->deltas, i, delta) {
+		if ((error = git_vector_insert(&paths, (char *)delta->new_file.path)) < 0)
+			goto done;
+	}
+
+	for (i = 0; i < git_index_entrycount(index_new); i++) {
+		e = git_index_get_byindex(index_new, i);
+
+		if (git_index_entry_is_conflict(e) &&
+			(git_vector_last(&paths) == NULL ||
+			strcmp(git_vector_last(&paths), e->path) != 0)) {
+
+			if ((error = git_vector_insert(&paths, (char *)e->path)) < 0)
+				goto done;
+		}
+	}
+
+	/* Make sure the index and workdir state do not prevent merging */
+	if ((error = merge_check_index(&index_conflicts, repo, index_new, &paths)) < 0 ||
+		(error = merge_check_workdir(&wd_conflicts, repo, index_new, &paths)) < 0)
+		goto done;
+
+	if ((conflicts = index_conflicts + wd_conflicts) > 0) {
+		giterr_set(GITERR_MERGE, "%" PRIuZ " uncommitted change%s would be overwritten by merge",
+			conflicts, (conflicts != 1) ? "s" : "");
+		error = GIT_ECONFLICT;
+	}
+
+done:
+	git_vector_free(&paths);
+	git_tree_free(head_tree);
+	git_iterator_free(iter_head);
+	git_iterator_free(iter_new);
+	git_diff_free(merged_list);
+
+	return error;
+}
+
+int git_merge__append_conflicts_to_merge_msg(
+	git_repository *repo,
+	git_index *index)
+{
+	git_filebuf file = GIT_FILEBUF_INIT;
+	git_buf file_path = GIT_BUF_INIT;
+	const char *last = NULL;
+	size_t i;
+	int error;
+
+	if (!git_index_has_conflicts(index))
+		return 0;
+
+	if ((error = git_buf_joinpath(&file_path, repo->gitdir, GIT_MERGE_MSG_FILE)) < 0 ||
+		(error = git_filebuf_open(&file, file_path.ptr, GIT_FILEBUF_APPEND, GIT_MERGE_FILE_MODE)) < 0)
+		goto cleanup;
+
+	git_filebuf_printf(&file, "\nConflicts:\n");
+
+	for (i = 0; i < git_index_entrycount(index); i++) {
+		const git_index_entry *e = git_index_get_byindex(index, i);
+
+		if (!git_index_entry_is_conflict(e))
+			continue;
+
+		if (last == NULL || strcmp(e->path, last) != 0)
+			git_filebuf_printf(&file, "\t%s\n", e->path);
+
+		last = e->path;
+	}
+
+	error = git_filebuf_commit(&file);
+
+cleanup:
+	if (error < 0)
+		git_filebuf_cleanup(&file);
+
+	git_buf_free(&file_path);
+
+	return error;
+}
+
+static int merge_state_cleanup(git_repository *repo)
+{
+	const char *state_files[] = {
+		GIT_MERGE_HEAD_FILE,
+		GIT_MERGE_MODE_FILE,
+		GIT_MERGE_MSG_FILE,
+	};
+
+	return git_repository__cleanup_files(repo, state_files, ARRAY_SIZE(state_files));
+}
+
+static int merge_heads(
+	git_annotated_commit **ancestor_head_out,
+	git_annotated_commit **our_head_out,
+	git_repository *repo,
+	const git_annotated_commit **their_heads,
+	size_t their_heads_len)
+{
+	git_annotated_commit *ancestor_head = NULL, *our_head = NULL;
+	git_reference *our_ref = NULL;
+	int error = 0;
+
+	*ancestor_head_out = NULL;
+	*our_head_out = NULL;
+
+	if ((error = git_repository__ensure_not_bare(repo, "merge")) < 0)
+		goto done;
+
+	if ((error = git_reference_lookup(&our_ref, repo, GIT_HEAD_FILE)) < 0 ||
+		(error = git_annotated_commit_from_ref(&our_head, repo, our_ref)) < 0)
+		goto done;
+
+	if ((error = merge_ancestor_head(&ancestor_head, repo, our_head, their_heads, their_heads_len)) < 0) {
+		if (error != GIT_ENOTFOUND)
+			goto done;
+
+		giterr_clear();
+		error = 0;
+	}
+
+	*ancestor_head_out = ancestor_head;
+	*our_head_out = our_head;
+
+done:
+	if (error < 0) {
+		git_annotated_commit_free(ancestor_head);
+		git_annotated_commit_free(our_head);
+	}
+
+	git_reference_free(our_ref);
+
+	return error;
+}
+
+static int merge_preference(git_merge_preference_t *out, git_repository *repo)
+{
+	git_config *config;
+	const char *value;
+	int bool_value, error = 0;
+
+	*out = GIT_MERGE_PREFERENCE_NONE;
+
+	if ((error = git_repository_config_snapshot(&config, repo)) < 0)
+		goto done;
+
+	if ((error = git_config_get_string(&value, config, "merge.ff")) < 0) {
+		if (error == GIT_ENOTFOUND) {
+			giterr_clear();
+			error = 0;
+		}
+
+		goto done;
+	}
+
+	if (git_config_parse_bool(&bool_value, value) == 0) {
+		if (!bool_value)
+			*out |= GIT_MERGE_PREFERENCE_NO_FASTFORWARD;
+	} else {
+		if (strcasecmp(value, "only") == 0)
+			*out |= GIT_MERGE_PREFERENCE_FASTFORWARD_ONLY;
+	}
+
+done:
+	git_config_free(config);
+	return error;
+}
+
+int git_merge_analysis(
+	git_merge_analysis_t *analysis_out,
+	git_merge_preference_t *preference_out,
+	git_repository *repo,
+	const git_annotated_commit **their_heads,
+	size_t their_heads_len)
+{
+	git_annotated_commit *ancestor_head = NULL, *our_head = NULL;
+	int error = 0;
+
+	assert(analysis_out && preference_out && repo && their_heads);
+
+	if (their_heads_len != 1) {
+		giterr_set(GITERR_MERGE, "can only merge a single branch");
+		error = -1;
+		goto done;
+	}
+
+	*analysis_out = GIT_MERGE_ANALYSIS_NONE;
+
+	if ((error = merge_preference(preference_out, repo)) < 0)
+		goto done;
+
+	if (git_repository_head_unborn(repo)) {
+		*analysis_out |= GIT_MERGE_ANALYSIS_FASTFORWARD | GIT_MERGE_ANALYSIS_UNBORN;
+		goto done;
+	}
+
+	if ((error = merge_heads(&ancestor_head, &our_head, repo, their_heads, their_heads_len)) < 0)
+		goto done;
+
+	/* We're up-to-date if we're trying to merge our own common ancestor. */
+	if (ancestor_head && git_oid_equal(
+		git_annotated_commit_id(ancestor_head), git_annotated_commit_id(their_heads[0])))
+		*analysis_out |= GIT_MERGE_ANALYSIS_UP_TO_DATE;
+
+	/* We're fastforwardable if we're our own common ancestor. */
+	else if (ancestor_head && git_oid_equal(
+		git_annotated_commit_id(ancestor_head), git_annotated_commit_id(our_head)))
+		*analysis_out |= GIT_MERGE_ANALYSIS_FASTFORWARD | GIT_MERGE_ANALYSIS_NORMAL;
+
+	/* Otherwise, just a normal merge is possible. */
+	else
+		*analysis_out |= GIT_MERGE_ANALYSIS_NORMAL;
+
+done:
+	git_annotated_commit_free(ancestor_head);
+	git_annotated_commit_free(our_head);
+	return error;
+}
+
+int git_merge(
+	git_repository *repo,
+	const git_annotated_commit **their_heads,
+	size_t their_heads_len,
+	const git_merge_options *merge_opts,
+	const git_checkout_options *given_checkout_opts)
+{
+	git_reference *our_ref = NULL;
+	git_checkout_options checkout_opts;
+	git_annotated_commit *our_head = NULL, *base = NULL;
+	git_index *index = NULL;
+	git_indexwriter indexwriter = GIT_INDEXWRITER_INIT;
+	unsigned int checkout_strategy;
+	int error = 0;
+
+	assert(repo && their_heads);
+
+	if (their_heads_len != 1) {
+		giterr_set(GITERR_MERGE, "can only merge a single branch");
+		return -1;
+	}
+
+	if ((error = git_repository__ensure_not_bare(repo, "merge")) < 0)
+		goto done;
+
+	checkout_strategy = given_checkout_opts ?
+		given_checkout_opts->checkout_strategy :
+		GIT_CHECKOUT_SAFE;
+
+	if ((error = git_indexwriter_init_for_operation(&indexwriter, repo,
+		&checkout_strategy)) < 0)
+		goto done;
+
+	/* Write the merge setup files to the repository. */
+	if ((error = git_annotated_commit_from_head(&our_head, repo)) < 0 ||
+		(error = git_merge__setup(repo, our_head, their_heads,
+			their_heads_len)) < 0)
+		goto done;
+
+	/* TODO: octopus */
+
+	if ((error = merge_annotated_commits(&index, &base, repo, our_head,
+			(git_annotated_commit *)their_heads[0], 0, merge_opts)) < 0 ||
+		(error = git_merge__check_result(repo, index)) < 0 ||
+		(error = git_merge__append_conflicts_to_merge_msg(repo, index)) < 0)
+		goto done;
+
+	/* check out the merge results */
+
+	if ((error = merge_normalize_checkout_opts(&checkout_opts, repo,
+			given_checkout_opts, checkout_strategy,
+			base, our_head, their_heads, their_heads_len)) < 0 ||
+		(error = git_checkout_index(repo, index, &checkout_opts)) < 0)
+		goto done;
+
+	error = git_indexwriter_commit(&indexwriter);
+
+done:
+	if (error < 0)
+		merge_state_cleanup(repo);
+
+	git_indexwriter_cleanup(&indexwriter);
+	git_index_free(index);
+	git_annotated_commit_free(our_head);
+	git_annotated_commit_free(base);
+	git_reference_free(our_ref);
+
+	return error;
+}
+
+int git_merge_init_options(git_merge_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_merge_options, GIT_MERGE_OPTIONS_INIT);
+	return 0;
+}
+
+int git_merge_file_init_input(git_merge_file_input *input, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		input, version, git_merge_file_input, GIT_MERGE_FILE_INPUT_INIT);
+	return 0;
+}
+
+int git_merge_file_init_options(
+	git_merge_file_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_merge_file_options, GIT_MERGE_FILE_OPTIONS_INIT);
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/merge.h

diff --git a/vendor/libgit2-sys/libgit2/src/merge.h b/vendor/libgit2-sys/libgit2/src/merge.h
new file mode 100644
index 0000000..173a1b4
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/merge.h
@@ -0,0 +1,216 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_merge_h__
+#define INCLUDE_merge_h__
+
+#include "common.h"
+
+#include "vector.h"
+#include "commit_list.h"
+#include "pool.h"
+#include "iterator.h"
+
+#include "git2/types.h"
+#include "git2/merge.h"
+#include "git2/sys/merge.h"
+
+#define GIT_MERGE_MSG_FILE		"MERGE_MSG"
+#define GIT_MERGE_MODE_FILE		"MERGE_MODE"
+#define GIT_MERGE_FILE_MODE		0666
+
+#define GIT_MERGE_DEFAULT_RENAME_THRESHOLD	50
+#define GIT_MERGE_DEFAULT_TARGET_LIMIT		1000
+
+
+/** Internal merge flags. */
+enum {
+	/** The merge is for a virtual base in a recursive merge. */
+	GIT_MERGE__VIRTUAL_BASE = (1 << 31),
+};
+
+enum {
+	/** Accept the conflict file, staging it as the merge result. */
+	GIT_MERGE_FILE_FAVOR__CONFLICTED = 4,
+};
+
+
+/** Types of changes when files are merged from branch to branch. */
+typedef enum {
+	/* No conflict - a change only occurs in one branch. */
+	GIT_MERGE_DIFF_NONE = 0,
+
+	/* Occurs when a file is modified in both branches. */
+	GIT_MERGE_DIFF_BOTH_MODIFIED = (1 << 0),
+
+	/* Occurs when a file is added in both branches. */
+	GIT_MERGE_DIFF_BOTH_ADDED = (1 << 1),
+
+	/* Occurs when a file is deleted in both branches. */
+	GIT_MERGE_DIFF_BOTH_DELETED = (1 << 2),
+
+	/* Occurs when a file is modified in one branch and deleted in the other. */
+	GIT_MERGE_DIFF_MODIFIED_DELETED = (1 << 3),
+
+	/* Occurs when a file is renamed in one branch and modified in the other. */
+	GIT_MERGE_DIFF_RENAMED_MODIFIED = (1 << 4),
+
+	/* Occurs when a file is renamed in one branch and deleted in the other. */
+	GIT_MERGE_DIFF_RENAMED_DELETED = (1 << 5),
+
+	/* Occurs when a file is renamed in one branch and a file with the same
+	 * name is added in the other.  Eg, A->B and new file B.  Core git calls
+	 * this a "rename/delete". */
+	GIT_MERGE_DIFF_RENAMED_ADDED = (1 << 6),
+
+	/* Occurs when both a file is renamed to the same name in the ours and
+	 * theirs branches.  Eg, A->B and A->B in both.  Automergeable. */
+	GIT_MERGE_DIFF_BOTH_RENAMED = (1 << 7),
+
+	/* Occurs when a file is renamed to different names in the ours and theirs
+	 * branches.  Eg, A->B and A->C. */
+	GIT_MERGE_DIFF_BOTH_RENAMED_1_TO_2 = (1 << 8),
+
+	/* Occurs when two files are renamed to the same name in the ours and
+	 * theirs branches.  Eg, A->C and B->C. */
+	GIT_MERGE_DIFF_BOTH_RENAMED_2_TO_1 = (1 << 9),
+
+	/* Occurs when an item at a path in one branch is a directory, and an
+	 * item at the same path in a different branch is a file. */
+	GIT_MERGE_DIFF_DIRECTORY_FILE = (1 << 10),
+
+	/* The child of a folder that is in a directory/file conflict. */
+	GIT_MERGE_DIFF_DF_CHILD = (1 << 11),
+} git_merge_diff_type_t;
+
+typedef struct {
+	git_repository *repo;
+	git_pool pool;
+
+	/* Vector of git_index_entry that represent the merged items that
+	 * have been staged, either because only one side changed, or because
+	 * the two changes were non-conflicting and mergeable.  These items
+	 * will be written as staged entries in the main index.
+	 */
+	git_vector staged;
+
+	/* Vector of git_merge_diff entries that represent the conflicts that
+	 * have not been automerged.  These items will be written to high-stage
+	 * entries in the main index.
+	 */
+	git_vector conflicts;
+
+	/* Vector of git_merge_diff that have been automerged.  These items
+	 * will be written to the REUC when the index is produced.
+	 */
+	git_vector resolved;
+} git_merge_diff_list;
+
+/**
+ * Description of changes to one file across three trees.
+ */
+typedef struct {
+	git_merge_diff_type_t type;
+
+	git_index_entry ancestor_entry;
+
+	git_index_entry our_entry;
+	git_delta_t our_status;
+
+	git_index_entry their_entry;
+	git_delta_t their_status;
+
+} git_merge_diff;
+
+int git_merge__bases_many(
+	git_commit_list **out,
+	git_revwalk *walk,
+	git_commit_list_node *one,
+	git_vector *twos);
+
+/*
+ * Three-way tree differencing
+ */
+
+git_merge_diff_list *git_merge_diff_list__alloc(git_repository *repo);
+
+int git_merge_diff_list__find_differences(
+	git_merge_diff_list *merge_diff_list,
+	git_iterator *ancestor_iterator,
+	git_iterator *ours_iter,
+	git_iterator *theirs_iter);
+
+int git_merge_diff_list__find_renames(git_repository *repo, git_merge_diff_list *merge_diff_list, const git_merge_options *opts);
+
+void git_merge_diff_list__free(git_merge_diff_list *diff_list);
+
+/* Merge metadata setup */
+
+int git_merge__setup(
+	git_repository *repo,
+	const git_annotated_commit *our_head,
+	const git_annotated_commit *heads[],
+	size_t heads_len);
+
+int git_merge__iterators(
+	git_index **out,
+	git_repository *repo,
+	git_iterator *ancestor_iter,
+	git_iterator *our_iter,
+	git_iterator *their_iter,
+	const git_merge_options *given_opts);
+
+int git_merge__check_result(git_repository *repo, git_index *index_new);
+
+int git_merge__append_conflicts_to_merge_msg(git_repository *repo, git_index *index);
+
+/* Merge files */
+
+GIT_INLINE(const char *) git_merge_file__best_path(
+	const char *ancestor,
+	const char *ours,
+	const char *theirs)
+{
+	if (!ancestor) {
+		if (ours && theirs && strcmp(ours, theirs) == 0)
+			return ours;
+
+		return NULL;
+	}
+
+	if (ours && strcmp(ancestor, ours) == 0)
+		return theirs;
+	else if(theirs && strcmp(ancestor, theirs) == 0)
+		return ours;
+
+	return NULL;
+}
+
+GIT_INLINE(uint32_t) git_merge_file__best_mode(
+	uint32_t ancestor, uint32_t ours, uint32_t theirs)
+{
+	/*
+	 * If ancestor didn't exist and either ours or theirs is executable,
+	 * assume executable.  Otherwise, if any mode changed from the ancestor,
+	 * use that one.
+	 */
+	if (!ancestor) {
+		if (ours == GIT_FILEMODE_BLOB_EXECUTABLE ||
+			theirs == GIT_FILEMODE_BLOB_EXECUTABLE)
+			return GIT_FILEMODE_BLOB_EXECUTABLE;
+
+		return GIT_FILEMODE_BLOB;
+	} else if (ours && theirs) {
+		if (ancestor == ours)
+			return theirs;
+
+		return ours;
+	}
+
+	return 0;
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/merge_driver.c

diff --git a/vendor/libgit2-sys/libgit2/src/merge_driver.c b/vendor/libgit2-sys/libgit2/src/merge_driver.c
new file mode 100644
index 0000000..ea4bd27
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/merge_driver.c
@@ -0,0 +1,426 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "merge_driver.h"
+
+#include "vector.h"
+#include "global.h"
+#include "merge.h"
+#include "git2/merge.h"
+#include "git2/sys/merge.h"
+
+static const char *merge_driver_name__text = "text";
+static const char *merge_driver_name__union = "union";
+static const char *merge_driver_name__binary = "binary";
+
+struct merge_driver_registry {
+	git_rwlock lock;
+	git_vector drivers;
+};
+
+typedef struct {
+	git_merge_driver *driver;
+	int initialized;
+	char name[GIT_FLEX_ARRAY];
+} git_merge_driver_entry;
+
+static struct merge_driver_registry merge_driver_registry;
+
+static void git_merge_driver_global_shutdown(void);
+
+const git_repository* git_merge_driver_source_repo(const git_merge_driver_source *src)
+{
+	assert(src);
+	return src->repo;
+}
+
+const git_index_entry* git_merge_driver_source_ancestor(const git_merge_driver_source *src)
+{
+	assert(src);
+	return src->ancestor;
+}
+
+const git_index_entry* git_merge_driver_source_ours(const git_merge_driver_source *src)
+{
+	assert(src);
+	return src->ours;
+}
+
+const git_index_entry* git_merge_driver_source_theirs(const git_merge_driver_source *src)
+{
+	assert(src);
+	return src->theirs;
+}
+
+const git_merge_file_options* git_merge_driver_source_file_options(const git_merge_driver_source *src)
+{
+	assert(src);
+	return src->file_opts;
+}
+
+int git_merge_driver__builtin_apply(
+	git_merge_driver *self,
+	const char **path_out,
+	uint32_t *mode_out,
+	git_buf *merged_out,
+	const char *filter_name,
+	const git_merge_driver_source *src)
+{
+	git_merge_driver__builtin *driver = (git_merge_driver__builtin *)self;
+	git_merge_file_options file_opts = GIT_MERGE_FILE_OPTIONS_INIT;
+	git_merge_file_result result = {0};
+	int error;
+
+	GIT_UNUSED(filter_name);
+
+	if (src->file_opts)
+		memcpy(&file_opts, src->file_opts, sizeof(git_merge_file_options));
+
+	if (driver->favor)
+		file_opts.favor = driver->favor;
+
+	if ((error = git_merge_file_from_index(&result, src->repo,
+		src->ancestor, src->ours, src->theirs, &file_opts)) < 0)
+		goto done;
+
+	if (!result.automergeable &&
+		!(file_opts.flags & GIT_MERGE_FILE_FAVOR__CONFLICTED)) {
+		error = GIT_EMERGECONFLICT;
+		goto done;
+	}
+
+	*path_out = git_merge_file__best_path(
+		src->ancestor ? src->ancestor->path : NULL,
+		src->ours ? src->ours->path : NULL,
+		src->theirs ? src->theirs->path : NULL);
+
+	*mode_out = git_merge_file__best_mode(
+		src->ancestor ? src->ancestor->mode : 0,
+		src->ours ? src->ours->mode : 0,
+		src->theirs ? src->theirs->mode : 0);
+
+	merged_out->ptr = (char *)result.ptr;
+	merged_out->size = result.len;
+	merged_out->asize = result.len;
+	result.ptr = NULL;
+
+done:
+	git_merge_file_result_free(&result);
+	return error;
+}
+
+static int merge_driver_binary_apply(
+	git_merge_driver *self,
+	const char **path_out,
+	uint32_t *mode_out,
+	git_buf *merged_out,
+	const char *filter_name,
+	const git_merge_driver_source *src)
+{
+	GIT_UNUSED(self);
+	GIT_UNUSED(path_out);
+	GIT_UNUSED(mode_out);
+	GIT_UNUSED(merged_out);
+	GIT_UNUSED(filter_name);
+	GIT_UNUSED(src);
+
+	return GIT_EMERGECONFLICT;
+}
+
+static int merge_driver_entry_cmp(const void *a, const void *b)
+{
+	const git_merge_driver_entry *entry_a = a;
+	const git_merge_driver_entry *entry_b = b;
+
+	return strcmp(entry_a->name, entry_b->name);
+}
+
+static int merge_driver_entry_search(const void *a, const void *b)
+{
+	const char *name_a = a;
+	const git_merge_driver_entry *entry_b = b;
+
+	return strcmp(name_a, entry_b->name);
+}
+
+git_merge_driver__builtin git_merge_driver__text = {
+	{
+		GIT_MERGE_DRIVER_VERSION,
+		NULL,
+		NULL,
+		git_merge_driver__builtin_apply,
+	},
+	GIT_MERGE_FILE_FAVOR_NORMAL
+};
+
+git_merge_driver__builtin git_merge_driver__union = {
+	{
+		GIT_MERGE_DRIVER_VERSION,
+		NULL,
+		NULL,
+		git_merge_driver__builtin_apply,
+	},
+	GIT_MERGE_FILE_FAVOR_UNION
+};
+
+git_merge_driver git_merge_driver__binary = {
+	GIT_MERGE_DRIVER_VERSION,
+	NULL,
+	NULL,
+	merge_driver_binary_apply
+};
+
+/* Note: callers must lock the registry before calling this function */
+static int merge_driver_registry_insert(
+	const char *name, git_merge_driver *driver)
+{
+	git_merge_driver_entry *entry;
+
+	entry = git__calloc(1, sizeof(git_merge_driver_entry) + strlen(name) + 1);
+	GITERR_CHECK_ALLOC(entry);
+
+	strcpy(entry->name, name);
+	entry->driver = driver;
+
+	return git_vector_insert_sorted(
+		&merge_driver_registry.drivers, entry, NULL);
+}
+
+int git_merge_driver_global_init(void)
+{
+	int error;
+
+	if (git_rwlock_init(&merge_driver_registry.lock) < 0)
+		return -1;
+
+	if ((error = git_vector_init(&merge_driver_registry.drivers, 3,
+		merge_driver_entry_cmp)) < 0)
+		goto done;
+
+	if ((error = merge_driver_registry_insert(
+			merge_driver_name__text, &git_merge_driver__text.base)) < 0 ||
+		(error = merge_driver_registry_insert(
+			merge_driver_name__union, &git_merge_driver__union.base)) < 0 ||
+		(error = merge_driver_registry_insert(
+			merge_driver_name__binary, &git_merge_driver__binary)) < 0)
+		goto done;
+
+	git__on_shutdown(git_merge_driver_global_shutdown);
+
+done:
+	if (error < 0)
+		git_vector_free_deep(&merge_driver_registry.drivers);
+
+	return error;
+}
+
+static void git_merge_driver_global_shutdown(void)
+{
+	git_merge_driver_entry *entry;
+	size_t i;
+
+	if (git_rwlock_wrlock(&merge_driver_registry.lock) < 0)
+		return;
+
+	git_vector_foreach(&merge_driver_registry.drivers, i, entry) {
+		if (entry->driver->shutdown)
+			entry->driver->shutdown(entry->driver);
+
+		git__free(entry);
+	}
+
+	git_vector_free(&merge_driver_registry.drivers);
+
+	git_rwlock_wrunlock(&merge_driver_registry.lock);
+	git_rwlock_free(&merge_driver_registry.lock);
+}
+
+/* Note: callers must lock the registry before calling this function */
+static int merge_driver_registry_find(size_t *pos, const char *name)
+{
+	return git_vector_search2(pos, &merge_driver_registry.drivers,
+		merge_driver_entry_search, name);
+}
+
+/* Note: callers must lock the registry before calling this function */
+static git_merge_driver_entry *merge_driver_registry_lookup(
+	size_t *pos, const char *name)
+{
+	git_merge_driver_entry *entry = NULL;
+
+	if (!merge_driver_registry_find(pos, name))
+		entry = git_vector_get(&merge_driver_registry.drivers, *pos);
+
+	return entry;
+}
+
+int git_merge_driver_register(const char *name, git_merge_driver *driver)
+{
+	int error;
+
+	assert(name && driver);
+
+	if (git_rwlock_wrlock(&merge_driver_registry.lock) < 0) {
+		giterr_set(GITERR_OS, "failed to lock merge driver registry");
+		return -1;
+	}
+
+	if (!merge_driver_registry_find(NULL, name)) {
+		giterr_set(GITERR_MERGE, "attempt to reregister existing driver '%s'",
+			name);
+		error = GIT_EEXISTS;
+		goto done;
+	}
+
+	error = merge_driver_registry_insert(name, driver);
+
+done:
+	git_rwlock_wrunlock(&merge_driver_registry.lock);
+	return error;
+}
+
+int git_merge_driver_unregister(const char *name)
+{
+	git_merge_driver_entry *entry;
+	size_t pos;
+	int error = 0;
+
+	if (git_rwlock_wrlock(&merge_driver_registry.lock) < 0) {
+		giterr_set(GITERR_OS, "failed to lock merge driver registry");
+		return -1;
+	}
+
+	if ((entry = merge_driver_registry_lookup(&pos, name)) == NULL) {
+		giterr_set(GITERR_MERGE, "cannot find merge driver '%s' to unregister",
+			name);
+		error = GIT_ENOTFOUND;
+		goto done;
+	}
+
+	git_vector_remove(&merge_driver_registry.drivers, pos);
+
+	if (entry->initialized && entry->driver->shutdown) {
+		entry->driver->shutdown(entry->driver);
+		entry->initialized = false;
+	}
+
+	git__free(entry);
+
+done:
+	git_rwlock_wrunlock(&merge_driver_registry.lock);
+	return error;
+}
+
+git_merge_driver *git_merge_driver_lookup(const char *name)
+{
+	git_merge_driver_entry *entry;
+	size_t pos;
+	int error;
+
+	/* If we've decided the merge driver to use internally - and not
+	 * based on user configuration (in merge_driver_name_for_path)
+	 * then we can use a hardcoded name to compare instead of bothering
+	 * to take a lock and look it up in the vector.
+	 */
+	if (name == merge_driver_name__text)
+		return &git_merge_driver__text.base;
+	else if (name == merge_driver_name__binary)
+		return &git_merge_driver__binary;
+
+	if (git_rwlock_rdlock(&merge_driver_registry.lock) < 0) {
+		giterr_set(GITERR_OS, "failed to lock merge driver registry");
+		return NULL;
+	}
+
+	entry = merge_driver_registry_lookup(&pos, name);
+
+	git_rwlock_rdunlock(&merge_driver_registry.lock);
+
+	if (entry == NULL) {
+		giterr_set(GITERR_MERGE, "cannot use an unregistered filter");
+		return NULL;
+	}
+
+	if (!entry->initialized) {
+		if (entry->driver->initialize &&
+			(error = entry->driver->initialize(entry->driver)) < 0)
+			return NULL;
+
+		entry->initialized = 1;
+	}
+
+	return entry->driver;
+}
+
+static int merge_driver_name_for_path(
+	const char **out,
+	git_repository *repo,
+	const char *path,
+	const char *default_driver)
+{
+	const char *value;
+	int error;
+
+	*out = NULL;
+
+	if ((error = git_attr_get(&value, repo, 0, path, "merge")) < 0)
+		return error;
+
+	/* set: use the built-in 3-way merge driver ("text") */
+	if (GIT_ATTR_TRUE(value))
+		*out = merge_driver_name__text;
+
+	/* unset: do not merge ("binary") */
+	else if (GIT_ATTR_FALSE(value))
+		*out = merge_driver_name__binary;
+
+	else if (GIT_ATTR_UNSPECIFIED(value) && default_driver)
+		*out = default_driver;
+
+	else if (GIT_ATTR_UNSPECIFIED(value))
+		*out = merge_driver_name__text;
+
+	else
+		*out = value;
+
+	return 0;
+}
+
+
+GIT_INLINE(git_merge_driver *) merge_driver_lookup_with_wildcard(
+	const char *name)
+{
+	git_merge_driver *driver = git_merge_driver_lookup(name);
+
+	if (driver == NULL)
+		driver = git_merge_driver_lookup("*");
+
+	return driver;
+}
+
+int git_merge_driver_for_source(
+	const char **name_out,
+	git_merge_driver **driver_out,
+	const git_merge_driver_source *src)
+{
+	const char *path, *driver_name;
+	int error = 0;
+
+	path = git_merge_file__best_path(
+		src->ancestor ? src->ancestor->path : NULL,
+		src->ours ? src->ours->path : NULL,
+		src->theirs ? src->theirs->path : NULL);
+
+	if ((error = merge_driver_name_for_path(
+			&driver_name, src->repo, path, src->default_driver)) < 0)
+		return error;
+
+	*name_out = driver_name;
+	*driver_out = merge_driver_lookup_with_wildcard(driver_name);
+	return error;
+}
+

vendor/libgit2-sys/libgit2/src/merge_driver.h

diff --git a/vendor/libgit2-sys/libgit2/src/merge_driver.h b/vendor/libgit2-sys/libgit2/src/merge_driver.h
new file mode 100644
index 0000000..6b7da52
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/merge_driver.h
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_merge_driver_h__
+#define INCLUDE_merge_driver_h__
+
+#include "common.h"
+
+#include "git2/merge.h"
+#include "git2/index.h"
+#include "git2/sys/merge.h"
+
+struct git_merge_driver_source {
+	git_repository *repo;
+	const char *default_driver;
+	const git_merge_file_options *file_opts;
+
+	const git_index_entry *ancestor;
+	const git_index_entry *ours;
+	const git_index_entry *theirs;
+};
+
+typedef struct git_merge_driver__builtin {
+	git_merge_driver base;
+	git_merge_file_favor_t favor;
+} git_merge_driver__builtin;
+
+extern int git_merge_driver_global_init(void);
+
+extern int git_merge_driver_for_path(
+	char **name_out,
+	git_merge_driver **driver_out,
+	git_repository *repo,
+	const char *path);
+
+/* Merge driver configuration */
+extern int git_merge_driver_for_source(
+	const char **name_out,
+	git_merge_driver **driver_out,
+	const git_merge_driver_source *src);
+
+extern int git_merge_driver__builtin_apply(
+	git_merge_driver *self,
+	const char **path_out,
+	uint32_t *mode_out,
+	git_buf *merged_out,
+	const char *filter_name,
+	const git_merge_driver_source *src);
+
+/* Merge driver for text files, performs a standard three-way merge */
+extern git_merge_driver__builtin git_merge_driver__text;
+
+/* Merge driver for union-style merging */
+extern git_merge_driver__builtin git_merge_driver__union;
+
+/* Merge driver for unmergeable (binary) files: always produces conflicts */
+extern git_merge_driver git_merge_driver__binary;
+
+#endif

vendor/libgit2-sys/libgit2/src/merge_file.c

diff --git a/vendor/libgit2-sys/libgit2/src/merge_file.c b/vendor/libgit2-sys/libgit2/src/merge_file.c
new file mode 100644
index 0000000..a36c198
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/merge_file.c
@@ -0,0 +1,311 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "repository.h"
+#include "posix.h"
+#include "fileops.h"
+#include "index.h"
+#include "diff_xdiff.h"
+#include "merge.h"
+
+#include "git2/repository.h"
+#include "git2/object.h"
+#include "git2/index.h"
+#include "git2/merge.h"
+
+#include "xdiff/xdiff.h"
+
+/* only examine the first 8000 bytes for binaryness.
+ * https://github.com/git/git/blob/77bd3ea9f54f1584147b594abc04c26ca516d987/xdiff-interface.c#L197
+ */
+#define GIT_MERGE_FILE_BINARY_SIZE 8000
+
+#define GIT_MERGE_FILE_SIDE_EXISTS(X)	((X)->mode != 0)
+
+int git_merge_file__input_from_index(
+	git_merge_file_input *input_out,
+	git_odb_object **odb_object_out,
+	git_odb *odb,
+	const git_index_entry *entry)
+{
+	int error = 0;
+
+	assert(input_out && odb_object_out && odb && entry);
+
+	if ((error = git_odb_read(odb_object_out, odb, &entry->id)) < 0)
+		goto done;
+
+	input_out->path = entry->path;
+	input_out->mode = entry->mode;
+	input_out->ptr = (char *)git_odb_object_data(*odb_object_out);
+	input_out->size = git_odb_object_size(*odb_object_out);
+
+done:
+	return error;
+}
+
+static void merge_file_normalize_opts(
+	git_merge_file_options *out,
+	const git_merge_file_options *given_opts)
+{
+	if (given_opts)
+		memcpy(out, given_opts, sizeof(git_merge_file_options));
+	else {
+		git_merge_file_options default_opts = GIT_MERGE_FILE_OPTIONS_INIT;
+		memcpy(out, &default_opts, sizeof(git_merge_file_options));
+	}
+}
+
+static int merge_file__xdiff(
+	git_merge_file_result *out,
+	const git_merge_file_input *ancestor,
+	const git_merge_file_input *ours,
+	const git_merge_file_input *theirs,
+	const git_merge_file_options *given_opts)
+{
+	xmparam_t xmparam;
+	mmfile_t ancestor_mmfile = {0}, our_mmfile = {0}, their_mmfile = {0};
+	mmbuffer_t mmbuffer;
+	git_merge_file_options options = GIT_MERGE_FILE_OPTIONS_INIT;
+	const char *path;
+	int xdl_result;
+	int error = 0;
+
+	memset(out, 0x0, sizeof(git_merge_file_result));
+
+	merge_file_normalize_opts(&options, given_opts);
+
+	memset(&xmparam, 0x0, sizeof(xmparam_t));
+
+	if (ancestor) {
+		xmparam.ancestor = (options.ancestor_label) ?
+			options.ancestor_label : ancestor->path;
+		ancestor_mmfile.ptr = (char *)ancestor->ptr;
+		ancestor_mmfile.size = ancestor->size;
+	}
+
+	xmparam.file1 = (options.our_label) ?
+		options.our_label : ours->path;
+	our_mmfile.ptr = (char *)ours->ptr;
+	our_mmfile.size = ours->size;
+
+	xmparam.file2 = (options.their_label) ?
+		options.their_label : theirs->path;
+	their_mmfile.ptr = (char *)theirs->ptr;
+	their_mmfile.size = theirs->size;
+
+	if (options.favor == GIT_MERGE_FILE_FAVOR_OURS)
+		xmparam.favor = XDL_MERGE_FAVOR_OURS;
+	else if (options.favor == GIT_MERGE_FILE_FAVOR_THEIRS)
+		xmparam.favor = XDL_MERGE_FAVOR_THEIRS;
+	else if (options.favor == GIT_MERGE_FILE_FAVOR_UNION)
+		xmparam.favor = XDL_MERGE_FAVOR_UNION;
+
+	xmparam.level = (options.flags & GIT_MERGE_FILE_SIMPLIFY_ALNUM) ?
+		XDL_MERGE_ZEALOUS_ALNUM : XDL_MERGE_ZEALOUS;
+
+	if (options.flags & GIT_MERGE_FILE_STYLE_DIFF3)
+		xmparam.style = XDL_MERGE_DIFF3;
+
+	if (options.flags & GIT_MERGE_FILE_IGNORE_WHITESPACE)
+		xmparam.xpp.flags |= XDF_IGNORE_WHITESPACE;
+	if (options.flags & GIT_MERGE_FILE_IGNORE_WHITESPACE_CHANGE)
+		xmparam.xpp.flags |= XDF_IGNORE_WHITESPACE_CHANGE;
+	if (options.flags & GIT_MERGE_FILE_IGNORE_WHITESPACE_EOL)
+		xmparam.xpp.flags |= XDF_IGNORE_WHITESPACE_AT_EOL;
+
+	if (options.flags & GIT_MERGE_FILE_DIFF_PATIENCE)
+		xmparam.xpp.flags |= XDF_PATIENCE_DIFF;
+
+	if (options.flags & GIT_MERGE_FILE_DIFF_MINIMAL)
+		xmparam.xpp.flags |= XDF_NEED_MINIMAL;
+
+	xmparam.marker_size = options.marker_size;
+
+	if ((xdl_result = xdl_merge(&ancestor_mmfile, &our_mmfile,
+		&their_mmfile, &xmparam, &mmbuffer)) < 0) {
+		giterr_set(GITERR_MERGE, "failed to merge files");
+		error = -1;
+		goto done;
+	}
+
+	path = git_merge_file__best_path(
+		ancestor ? ancestor->path : NULL,
+		ours->path,
+		theirs->path);
+
+	if (path != NULL && (out->path = git__strdup(path)) == NULL) {
+		error = -1;
+		goto done;
+	}
+
+	out->automergeable = (xdl_result == 0);
+	out->ptr = (const char *)mmbuffer.ptr;
+	out->len = mmbuffer.size;
+	out->mode = git_merge_file__best_mode(
+		ancestor ? ancestor->mode : 0,
+		ours->mode,
+		theirs->mode);
+
+done:
+	if (error < 0)
+		git_merge_file_result_free(out);
+
+	return error;
+}
+
+static bool merge_file__is_binary(const git_merge_file_input *file)
+{
+	size_t len = file ? file->size : 0;
+
+	if (len > GIT_XDIFF_MAX_SIZE)
+		return true;
+	if (len > GIT_MERGE_FILE_BINARY_SIZE)
+		len = GIT_MERGE_FILE_BINARY_SIZE;
+
+	return len ? (memchr(file->ptr, 0, len) != NULL) : false;
+}
+
+static int merge_file__binary(
+	git_merge_file_result *out,
+	const git_merge_file_input *ours,
+	const git_merge_file_input *theirs,
+	const git_merge_file_options *given_opts)
+{
+	const git_merge_file_input *favored = NULL;
+
+	memset(out, 0x0, sizeof(git_merge_file_result));
+
+	if (given_opts && given_opts->favor == GIT_MERGE_FILE_FAVOR_OURS)
+		favored = ours;
+	else if (given_opts && given_opts->favor == GIT_MERGE_FILE_FAVOR_THEIRS)
+		favored = theirs;
+	else
+		goto done;
+
+	if ((out->path = git__strdup(favored->path)) == NULL ||
+		(out->ptr = git__malloc(favored->size)) == NULL)
+		goto done;
+
+	memcpy((char *)out->ptr, favored->ptr, favored->size);
+	out->len = favored->size;
+	out->mode = favored->mode;
+	out->automergeable = 1;
+
+done:
+	return 0;
+}
+
+static int merge_file__from_inputs(
+	git_merge_file_result *out,
+	const git_merge_file_input *ancestor,
+	const git_merge_file_input *ours,
+	const git_merge_file_input *theirs,
+	const git_merge_file_options *given_opts)
+{
+	if (merge_file__is_binary(ancestor) ||
+		merge_file__is_binary(ours) ||
+		merge_file__is_binary(theirs))
+		return merge_file__binary(out, ours, theirs, given_opts);
+
+	return merge_file__xdiff(out, ancestor, ours, theirs, given_opts);
+}
+
+static git_merge_file_input *git_merge_file__normalize_inputs(
+	git_merge_file_input *out,
+	const git_merge_file_input *given)
+{
+	memcpy(out, given, sizeof(git_merge_file_input));
+
+	if (!out->path)
+		out->path = "file.txt";
+
+	if (!out->mode)
+		out->mode = 0100644;
+
+	return out;
+}
+
+int git_merge_file(
+	git_merge_file_result *out,
+	const git_merge_file_input *ancestor,
+	const git_merge_file_input *ours,
+	const git_merge_file_input *theirs,
+	const git_merge_file_options *options)
+{
+	git_merge_file_input inputs[3] = { {0} };
+
+	assert(out && ours && theirs);
+
+	memset(out, 0x0, sizeof(git_merge_file_result));
+
+	if (ancestor)
+		ancestor = git_merge_file__normalize_inputs(&inputs[0], ancestor);
+
+	ours = git_merge_file__normalize_inputs(&inputs[1], ours);
+	theirs = git_merge_file__normalize_inputs(&inputs[2], theirs);
+
+	return merge_file__from_inputs(out, ancestor, ours, theirs, options);
+}
+
+int git_merge_file_from_index(
+	git_merge_file_result *out,
+	git_repository *repo,
+	const git_index_entry *ancestor,
+	const git_index_entry *ours,
+	const git_index_entry *theirs,
+	const git_merge_file_options *options)
+{
+	git_merge_file_input *ancestor_ptr = NULL,
+		ancestor_input = {0}, our_input = {0}, their_input = {0};
+	git_odb *odb = NULL;
+	git_odb_object *odb_object[3] = { 0 };
+	int error = 0;
+
+	assert(out && repo && ours && theirs);
+
+	memset(out, 0x0, sizeof(git_merge_file_result));
+
+	if ((error = git_repository_odb(&odb, repo)) < 0)
+		goto done;
+
+	if (ancestor) {
+		if ((error = git_merge_file__input_from_index(
+			&ancestor_input, &odb_object[0], odb, ancestor)) < 0)
+			goto done;
+
+		ancestor_ptr = &ancestor_input;
+	}
+
+	if ((error = git_merge_file__input_from_index(
+			&our_input, &odb_object[1], odb, ours)) < 0 ||
+		(error = git_merge_file__input_from_index(
+			&their_input, &odb_object[2], odb, theirs)) < 0)
+		goto done;
+
+	error = merge_file__from_inputs(out,
+		ancestor_ptr, &our_input, &their_input, options);
+
+done:
+	git_odb_object_free(odb_object[0]);
+	git_odb_object_free(odb_object[1]);
+	git_odb_object_free(odb_object[2]);
+	git_odb_free(odb);
+
+	return error;
+}
+
+void git_merge_file_result_free(git_merge_file_result *result)
+{
+	if (result == NULL)
+		return;
+
+	git__free((char *)result->path);
+	git__free((char *)result->ptr);
+}

vendor/libgit2-sys/libgit2/src/message.c

diff --git a/vendor/libgit2-sys/libgit2/src/message.c b/vendor/libgit2-sys/libgit2/src/message.c
new file mode 100644
index 0000000..6c5a237
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/message.c
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "message.h"
+
+static size_t line_length_without_trailing_spaces(const char *line, size_t len)
+{
+	while (len) {
+		unsigned char c = line[len - 1];
+		if (!git__isspace(c))
+			break;
+		len--;
+	}
+
+	return len;
+}
+
+/* Greatly inspired from git.git "stripspace" */
+/* see https://github.com/git/git/blob/497215d8811ac7b8955693ceaad0899ecd894ed2/builtin/stripspace.c#L4-67 */
+int git_message_prettify(git_buf *message_out, const char *message, int strip_comments, char comment_char)
+{
+	const size_t message_len = strlen(message);
+
+	int consecutive_empty_lines = 0;
+	size_t i, line_length, rtrimmed_line_length;
+	char *next_newline;
+
+	git_buf_sanitize(message_out);
+
+	for (i = 0; i < strlen(message); i += line_length) {
+		next_newline = memchr(message + i, '\n', message_len - i);
+
+		if (next_newline != NULL) {
+			line_length = next_newline - (message + i) + 1;
+		} else {
+			line_length = message_len - i;
+		}
+
+		if (strip_comments && line_length && message[i] == comment_char)
+			continue;
+
+		rtrimmed_line_length = line_length_without_trailing_spaces(message + i, line_length);
+
+		if (!rtrimmed_line_length) {
+			consecutive_empty_lines++;
+			continue;
+		}
+
+		if (consecutive_empty_lines > 0 && message_out->size > 0)
+			git_buf_putc(message_out, '\n');
+
+		consecutive_empty_lines = 0;
+		git_buf_put(message_out, message + i, rtrimmed_line_length);
+		git_buf_putc(message_out, '\n');
+	}
+
+	return git_buf_oom(message_out) ? -1 : 0;
+}

vendor/libgit2-sys/libgit2/src/message.h

diff --git a/vendor/libgit2-sys/libgit2/src/message.h b/vendor/libgit2-sys/libgit2/src/message.h
new file mode 100644
index 0000000..251727b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/message.h
@@ -0,0 +1,17 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_message_h__
+#define INCLUDE_message_h__
+
+#include "common.h"
+
+#include "git2/message.h"
+#include "buffer.h"
+
+int git_message__prettify(git_buf *message_out, const char *message, int strip_comments);
+
+#endif

vendor/libgit2-sys/libgit2/src/mwindow.c

diff --git a/vendor/libgit2-sys/libgit2/src/mwindow.c b/vendor/libgit2-sys/libgit2/src/mwindow.c
new file mode 100644
index 0000000..38d0352
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/mwindow.c
@@ -0,0 +1,427 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "mwindow.h"
+
+#include "vector.h"
+#include "fileops.h"
+#include "map.h"
+#include "global.h"
+#include "strmap.h"
+#include "pack.h"
+
+#define DEFAULT_WINDOW_SIZE \
+	(sizeof(void*) >= 8 \
+		? 1 * 1024 * 1024 * 1024 \
+		: 32 * 1024 * 1024)
+
+#define DEFAULT_MAPPED_LIMIT \
+	((1024 * 1024) * (sizeof(void*) >= 8 ? 8192ULL : 256UL))
+
+size_t git_mwindow__window_size = DEFAULT_WINDOW_SIZE;
+size_t git_mwindow__mapped_limit = DEFAULT_MAPPED_LIMIT;
+
+/* Whenever you want to read or modify this, grab git__mwindow_mutex */
+static git_mwindow_ctl mem_ctl;
+
+/* Global list of mwindow files, to open packs once across repos */
+git_strmap *git__pack_cache = NULL;
+
+static void git_mwindow_files_free(void)
+{
+	git_strmap *tmp = git__pack_cache;
+
+	git__pack_cache = NULL;
+	git_strmap_free(tmp);
+}
+
+int git_mwindow_global_init(void)
+{
+	assert(!git__pack_cache);
+
+	git__on_shutdown(git_mwindow_files_free);
+	return git_strmap_alloc(&git__pack_cache);
+}
+
+int git_mwindow_get_pack(struct git_pack_file **out, const char *path)
+{
+	int error;
+	char *packname;
+	git_strmap_iter pos;
+	struct git_pack_file *pack;
+
+	if ((error = git_packfile__name(&packname, path)) < 0)
+		return error;
+
+	if (git_mutex_lock(&git__mwindow_mutex) < 0) {
+		giterr_set(GITERR_OS, "failed to lock mwindow mutex");
+		return -1;
+	}
+
+	pos = git_strmap_lookup_index(git__pack_cache, packname);
+	git__free(packname);
+
+	if (git_strmap_valid_index(git__pack_cache, pos)) {
+		pack = git_strmap_value_at(git__pack_cache, pos);
+		git_atomic_inc(&pack->refcount);
+
+		git_mutex_unlock(&git__mwindow_mutex);
+		*out = pack;
+		return 0;
+	}
+
+	/* If we didn't find it, we need to create it */
+	if ((error = git_packfile_alloc(&pack, path)) < 0) {
+		git_mutex_unlock(&git__mwindow_mutex);
+		return error;
+	}
+
+	git_atomic_inc(&pack->refcount);
+
+	git_strmap_insert(git__pack_cache, pack->pack_name, pack, &error);
+	git_mutex_unlock(&git__mwindow_mutex);
+
+	if (error < 0) {
+		git_packfile_free(pack);
+		return -1;
+	}
+
+	*out = pack;
+	return 0;
+}
+
+void git_mwindow_put_pack(struct git_pack_file *pack)
+{
+	int count;
+	git_strmap_iter pos;
+
+	if (git_mutex_lock(&git__mwindow_mutex) < 0)
+		return;
+
+	/* put before get would be a corrupted state */
+	assert(git__pack_cache);
+
+	pos = git_strmap_lookup_index(git__pack_cache, pack->pack_name);
+	/* if we cannot find it, the state is corrupted */
+	assert(git_strmap_valid_index(git__pack_cache, pos));
+
+	count = git_atomic_dec(&pack->refcount);
+	if (count == 0) {
+		git_strmap_delete_at(git__pack_cache, pos);
+		git_packfile_free(pack);
+	}
+
+	git_mutex_unlock(&git__mwindow_mutex);
+	return;
+}
+
+void git_mwindow_free_all(git_mwindow_file *mwf)
+{
+	if (git_mutex_lock(&git__mwindow_mutex)) {
+		giterr_set(GITERR_THREAD, "unable to lock mwindow mutex");
+		return;
+	}
+
+	git_mwindow_free_all_locked(mwf);
+
+	git_mutex_unlock(&git__mwindow_mutex);
+}
+
+/*
+ * Free all the windows in a sequence, typically because we're done
+ * with the file
+ */
+void git_mwindow_free_all_locked(git_mwindow_file *mwf)
+{
+	git_mwindow_ctl *ctl = &mem_ctl;
+	size_t i;
+
+	/*
+	 * Remove these windows from the global list
+	 */
+	for (i = 0; i < ctl->windowfiles.length; ++i){
+		if (git_vector_get(&ctl->windowfiles, i) == mwf) {
+			git_vector_remove(&ctl->windowfiles, i);
+			break;
+		}
+	}
+
+	if (ctl->windowfiles.length == 0) {
+		git_vector_free(&ctl->windowfiles);
+		ctl->windowfiles.contents = NULL;
+	}
+
+	while (mwf->windows) {
+		git_mwindow *w = mwf->windows;
+		assert(w->inuse_cnt == 0);
+
+		ctl->mapped -= w->window_map.len;
+		ctl->open_windows--;
+
+		git_futils_mmap_free(&w->window_map);
+
+		mwf->windows = w->next;
+		git__free(w);
+	}
+}
+
+/*
+ * Check if a window 'win' contains the address 'offset'
+ */
+int git_mwindow_contains(git_mwindow *win, git_off_t offset)
+{
+	git_off_t win_off = win->offset;
+	return win_off <= offset
+		&& offset <= (git_off_t)(win_off + win->window_map.len);
+}
+
+/*
+ * Find the least-recently-used window in a file
+ */
+static void git_mwindow_scan_lru(
+	git_mwindow_file *mwf,
+	git_mwindow **lru_w,
+	git_mwindow **lru_l)
+{
+	git_mwindow *w, *w_l;
+
+	for (w_l = NULL, w = mwf->windows; w; w = w->next) {
+		if (!w->inuse_cnt) {
+			/*
+			 * If the current one is more recent than the last one,
+			 * store it in the output parameter. If lru_w is NULL,
+			 * it's the first loop, so store it as well.
+			 */
+			if (!*lru_w || w->last_used < (*lru_w)->last_used) {
+				*lru_w = w;
+				*lru_l = w_l;
+			}
+		}
+		w_l = w;
+	}
+}
+
+/*
+ * Close the least recently used window. You should check to see if
+ * the file descriptors need closing from time to time. Called under
+ * lock from new_window.
+ */
+static int git_mwindow_close_lru(git_mwindow_file *mwf)
+{
+	git_mwindow_ctl *ctl = &mem_ctl;
+	size_t i;
+	git_mwindow *lru_w = NULL, *lru_l = NULL, **list = &mwf->windows;
+
+	/* FIXME: Does this give us any advantage? */
+	if(mwf->windows)
+		git_mwindow_scan_lru(mwf, &lru_w, &lru_l);
+
+	for (i = 0; i < ctl->windowfiles.length; ++i) {
+		git_mwindow *last = lru_w;
+		git_mwindow_file *cur = git_vector_get(&ctl->windowfiles, i);
+		git_mwindow_scan_lru(cur, &lru_w, &lru_l);
+		if (lru_w != last)
+			list = &cur->windows;
+	}
+
+	if (!lru_w) {
+		giterr_set(GITERR_OS, "failed to close memory window; couldn't find LRU");
+		return -1;
+	}
+
+	ctl->mapped -= lru_w->window_map.len;
+	git_futils_mmap_free(&lru_w->window_map);
+
+	if (lru_l)
+		lru_l->next = lru_w->next;
+	else
+		*list = lru_w->next;
+
+	git__free(lru_w);
+	ctl->open_windows--;
+
+	return 0;
+}
+
+/* This gets called under lock from git_mwindow_open */
+static git_mwindow *new_window(
+	git_mwindow_file *mwf,
+	git_file fd,
+	git_off_t size,
+	git_off_t offset)
+{
+	git_mwindow_ctl *ctl = &mem_ctl;
+	size_t walign = git_mwindow__window_size / 2;
+	git_off_t len;
+	git_mwindow *w;
+
+	w = git__malloc(sizeof(*w));
+
+	if (w == NULL)
+		return NULL;
+
+	memset(w, 0x0, sizeof(*w));
+	w->offset = (offset / walign) * walign;
+
+	len = size - w->offset;
+	if (len > (git_off_t)git_mwindow__window_size)
+		len = (git_off_t)git_mwindow__window_size;
+
+	ctl->mapped += (size_t)len;
+
+	while (git_mwindow__mapped_limit < ctl->mapped &&
+			git_mwindow_close_lru(mwf) == 0) /* nop */;
+
+	/*
+	 * We treat `mapped_limit` as a soft limit. If we can't find a
+	 * window to close and are above the limit, we still mmap the new
+	 * window.
+	 */
+
+	if (git_futils_mmap_ro(&w->window_map, fd, w->offset, (size_t)len) < 0) {
+		/*
+		 * The first error might be down to memory fragmentation even if
+		 * we're below our soft limits, so free up what we can and try again.
+		 */
+
+		while (git_mwindow_close_lru(mwf) == 0)
+			/* nop */;
+
+		if (git_futils_mmap_ro(&w->window_map, fd, w->offset, (size_t)len) < 0) {
+			git__free(w);
+			return NULL;
+		}
+	}
+
+	ctl->mmap_calls++;
+	ctl->open_windows++;
+
+	if (ctl->mapped > ctl->peak_mapped)
+		ctl->peak_mapped = ctl->mapped;
+
+	if (ctl->open_windows > ctl->peak_open_windows)
+		ctl->peak_open_windows = ctl->open_windows;
+
+	return w;
+}
+
+/*
+ * Open a new window, closing the least recenty used until we have
+ * enough space. Don't forget to add it to your list
+ */
+unsigned char *git_mwindow_open(
+	git_mwindow_file *mwf,
+	git_mwindow **cursor,
+	git_off_t offset,
+	size_t extra,
+	unsigned int *left)
+{
+	git_mwindow_ctl *ctl = &mem_ctl;
+	git_mwindow *w = *cursor;
+
+	if (git_mutex_lock(&git__mwindow_mutex)) {
+		giterr_set(GITERR_THREAD, "unable to lock mwindow mutex");
+		return NULL;
+	}
+
+	if (!w || !(git_mwindow_contains(w, offset) && git_mwindow_contains(w, offset + extra))) {
+		if (w) {
+			w->inuse_cnt--;
+		}
+
+		for (w = mwf->windows; w; w = w->next) {
+			if (git_mwindow_contains(w, offset) &&
+				git_mwindow_contains(w, offset + extra))
+				break;
+		}
+
+		/*
+		 * If there isn't a suitable window, we need to create a new
+		 * one.
+		 */
+		if (!w) {
+			w = new_window(mwf, mwf->fd, mwf->size, offset);
+			if (w == NULL) {
+				git_mutex_unlock(&git__mwindow_mutex);
+				return NULL;
+			}
+			w->next = mwf->windows;
+			mwf->windows = w;
+		}
+	}
+
+	/* If we changed w, store it in the cursor */
+	if (w != *cursor) {
+		w->last_used = ctl->used_ctr++;
+		w->inuse_cnt++;
+		*cursor = w;
+	}
+
+	offset -= w->offset;
+
+	if (left)
+		*left = (unsigned int)(w->window_map.len - offset);
+
+	git_mutex_unlock(&git__mwindow_mutex);
+	return (unsigned char *) w->window_map.data + offset;
+}
+
+int git_mwindow_file_register(git_mwindow_file *mwf)
+{
+	git_mwindow_ctl *ctl = &mem_ctl;
+	int ret;
+
+	if (git_mutex_lock(&git__mwindow_mutex)) {
+		giterr_set(GITERR_THREAD, "unable to lock mwindow mutex");
+		return -1;
+	}
+
+	if (ctl->windowfiles.length == 0 &&
+	    git_vector_init(&ctl->windowfiles, 8, NULL) < 0) {
+		git_mutex_unlock(&git__mwindow_mutex);
+		return -1;
+	}
+
+	ret = git_vector_insert(&ctl->windowfiles, mwf);
+	git_mutex_unlock(&git__mwindow_mutex);
+
+	return ret;
+}
+
+void git_mwindow_file_deregister(git_mwindow_file *mwf)
+{
+	git_mwindow_ctl *ctl = &mem_ctl;
+	git_mwindow_file *cur;
+	size_t i;
+
+	if (git_mutex_lock(&git__mwindow_mutex))
+		return;
+
+	git_vector_foreach(&ctl->windowfiles, i, cur) {
+		if (cur == mwf) {
+			git_vector_remove(&ctl->windowfiles, i);
+			git_mutex_unlock(&git__mwindow_mutex);
+			return;
+		}
+	}
+	git_mutex_unlock(&git__mwindow_mutex);
+}
+
+void git_mwindow_close(git_mwindow **window)
+{
+	git_mwindow *w = *window;
+	if (w) {
+		if (git_mutex_lock(&git__mwindow_mutex)) {
+			giterr_set(GITERR_THREAD, "unable to lock mwindow mutex");
+			return;
+		}
+
+		w->inuse_cnt--;
+		git_mutex_unlock(&git__mwindow_mutex);
+		*window = NULL;
+	}
+}

vendor/libgit2-sys/libgit2/src/mwindow.h

diff --git a/vendor/libgit2-sys/libgit2/src/mwindow.h b/vendor/libgit2-sys/libgit2/src/mwindow.h
new file mode 100644
index 0000000..ea962d1
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/mwindow.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_mwindow__
+#define INCLUDE_mwindow__
+
+#include "common.h"
+
+#include "map.h"
+#include "vector.h"
+
+typedef struct git_mwindow {
+	struct git_mwindow *next;
+	git_map window_map;
+	git_off_t offset;
+	size_t last_used;
+	size_t inuse_cnt;
+} git_mwindow;
+
+typedef struct git_mwindow_file {
+	git_mwindow *windows;
+	int fd;
+	git_off_t size;
+} git_mwindow_file;
+
+typedef struct git_mwindow_ctl {
+	size_t mapped;
+	unsigned int open_windows;
+	unsigned int mmap_calls;
+	unsigned int peak_open_windows;
+	size_t peak_mapped;
+	size_t used_ctr;
+	git_vector windowfiles;
+} git_mwindow_ctl;
+
+int git_mwindow_contains(git_mwindow *win, git_off_t offset);
+void git_mwindow_free_all(git_mwindow_file *mwf); /* locks */
+void git_mwindow_free_all_locked(git_mwindow_file *mwf); /* run under lock */
+unsigned char *git_mwindow_open(git_mwindow_file *mwf, git_mwindow **cursor, git_off_t offset, size_t extra, unsigned int *left);
+int git_mwindow_file_register(git_mwindow_file *mwf);
+void git_mwindow_file_deregister(git_mwindow_file *mwf);
+void git_mwindow_close(git_mwindow **w_cursor);
+
+extern int git_mwindow_global_init(void);
+
+struct git_pack_file; /* just declaration to avoid cyclical includes */
+int git_mwindow_get_pack(struct git_pack_file **out, const char *path);
+void git_mwindow_put_pack(struct git_pack_file *pack);
+
+#endif

vendor/libgit2-sys/libgit2/src/netops.c

diff --git a/vendor/libgit2-sys/libgit2/src/netops.c b/vendor/libgit2-sys/libgit2/src/netops.c
new file mode 100644
index 0000000..fa20cba
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/netops.c
@@ -0,0 +1,301 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "netops.h"
+
+#include <ctype.h>
+#include "git2/errors.h"
+
+#include "posix.h"
+#include "buffer.h"
+#include "http_parser.h"
+#include "global.h"
+
+int gitno_recv(gitno_buffer *buf)
+{
+	return buf->recv(buf);
+}
+
+void gitno_buffer_setup_callback(
+	gitno_buffer *buf,
+	char *data,
+	size_t len,
+	int (*recv)(gitno_buffer *buf), void *cb_data)
+{
+	memset(data, 0x0, len);
+	buf->data = data;
+	buf->len = len;
+	buf->offset = 0;
+	buf->recv = recv;
+	buf->cb_data = cb_data;
+}
+
+static int recv_stream(gitno_buffer *buf)
+{
+	git_stream *io = (git_stream *) buf->cb_data;
+	int ret;
+
+	ret = git_stream_read(io, buf->data + buf->offset, buf->len - buf->offset);
+	if (ret < 0)
+		return -1;
+
+	buf->offset += ret;
+	return ret;
+}
+
+void gitno_buffer_setup_fromstream(git_stream *st, gitno_buffer *buf, char *data, size_t len)
+{
+	memset(data, 0x0, len);
+	buf->data = data;
+	buf->len = len;
+	buf->offset = 0;
+	buf->recv = recv_stream;
+	buf->cb_data = st;
+}
+
+/* Consume up to ptr and move the rest of the buffer to the beginning */
+void gitno_consume(gitno_buffer *buf, const char *ptr)
+{
+	size_t consumed;
+
+	assert(ptr - buf->data >= 0);
+	assert(ptr - buf->data <= (int) buf->len);
+
+	consumed = ptr - buf->data;
+
+	memmove(buf->data, ptr, buf->offset - consumed);
+	memset(buf->data + buf->offset, 0x0, buf->len - buf->offset);
+	buf->offset -= consumed;
+}
+
+/* Consume const bytes and move the rest of the buffer to the beginning */
+void gitno_consume_n(gitno_buffer *buf, size_t cons)
+{
+	memmove(buf->data, buf->data + cons, buf->len - buf->offset);
+	memset(buf->data + cons, 0x0, buf->len - buf->offset);
+	buf->offset -= cons;
+}
+
+/* Match host names according to RFC 2818 rules */
+int gitno__match_host(const char *pattern, const char *host)
+{
+	for (;;) {
+		char c = git__tolower(*pattern++);
+
+		if (c == '\0')
+			return *host ? -1 : 0;
+
+		if (c == '*') {
+			c = *pattern;
+			/* '*' at the end matches everything left */
+			if (c == '\0')
+				return 0;
+
+	/*
+	 * We've found a pattern, so move towards the next matching
+	 * char. The '.' is handled specially because wildcards aren't
+	 * allowed to cross subdomains.
+	 */
+
+			while(*host) {
+				char h = git__tolower(*host);
+				if (c == h)
+					return gitno__match_host(pattern, host++);
+				if (h == '.')
+					return gitno__match_host(pattern, host);
+				host++;
+			}
+			return -1;
+		}
+
+		if (c != git__tolower(*host++))
+			return -1;
+	}
+
+	return -1;
+}
+
+static const char *prefix_http = "http://";
+static const char *prefix_https = "https://";
+
+int gitno_connection_data_from_url(
+		gitno_connection_data *data,
+		const char *url,
+		const char *service_suffix)
+{
+	int error = -1;
+	const char *default_port = NULL, *path_search_start = NULL;
+	char *original_host = NULL;
+
+	/* service_suffix is optional */
+	assert(data && url);
+
+	/* Save these for comparison later */
+	original_host = data->host;
+	data->host = NULL;
+	gitno_connection_data_free_ptrs(data);
+
+	if (!git__prefixcmp(url, prefix_http)) {
+		path_search_start = url + strlen(prefix_http);
+		default_port = "80";
+
+		if (data->use_ssl) {
+			giterr_set(GITERR_NET, "redirect from HTTPS to HTTP is not allowed");
+			goto cleanup;
+		}
+	} else if (!git__prefixcmp(url, prefix_https)) {
+		path_search_start = url + strlen(prefix_https);
+		default_port = "443";
+		data->use_ssl = true;
+	} else if (url[0] == '/')
+		default_port = data->use_ssl ? "443" : "80";
+
+	if (!default_port) {
+		giterr_set(GITERR_NET, "unrecognized URL prefix");
+		goto cleanup;
+	}
+
+	error = gitno_extract_url_parts(
+		&data->host, &data->port, &data->path, &data->user, &data->pass,
+		url, default_port);
+
+	if (url[0] == '/') {
+		/* Relative redirect; reuse original host name and port */
+		path_search_start = url;
+		git__free(data->host);
+		data->host = original_host;
+		original_host = NULL;
+	}
+
+	if (!error) {
+		const char *path = strchr(path_search_start, '/');
+		size_t pathlen = strlen(path);
+		size_t suffixlen = service_suffix ? strlen(service_suffix) : 0;
+
+		if (suffixlen &&
+		    !memcmp(path + pathlen - suffixlen, service_suffix, suffixlen)) {
+			git__free(data->path);
+			data->path = git__strndup(path, pathlen - suffixlen);
+		} else {
+			git__free(data->path);
+			data->path = git__strdup(path);
+		}
+
+		/* Check for errors in the resulting data */
+		if (original_host && url[0] != '/' && strcmp(original_host, data->host)) {
+			giterr_set(GITERR_NET, "cross host redirect not allowed");
+			error = -1;
+		}
+	}
+
+cleanup:
+	if (original_host) git__free(original_host);
+	return error;
+}
+
+void gitno_connection_data_free_ptrs(gitno_connection_data *d)
+{
+	git__free(d->host); d->host = NULL;
+	git__free(d->port); d->port = NULL;
+	git__free(d->path); d->path = NULL;
+	git__free(d->user); d->user = NULL;
+	git__free(d->pass); d->pass = NULL;
+}
+
+int gitno_extract_url_parts(
+	char **host_out,
+	char **port_out,
+	char **path_out,
+	char **username_out,
+	char **password_out,
+	const char *url,
+	const char *default_port)
+{
+	struct http_parser_url u = {0};
+	bool has_host, has_port, has_path, has_userinfo;
+	git_buf host = GIT_BUF_INIT,
+		port = GIT_BUF_INIT,
+		path = GIT_BUF_INIT,
+		username = GIT_BUF_INIT,
+		password = GIT_BUF_INIT;
+	int error = 0;
+
+	if (http_parser_parse_url(url, strlen(url), false, &u)) {
+		giterr_set(GITERR_NET, "malformed URL '%s'", url);
+		error = GIT_EINVALIDSPEC;
+		goto done;
+	}
+
+	has_host = !!(u.field_set & (1 << UF_HOST));
+	has_port = !!(u.field_set & (1 << UF_PORT));
+	has_path = !!(u.field_set & (1 << UF_PATH));
+	has_userinfo = !!(u.field_set & (1 << UF_USERINFO));
+
+	if (has_host) {
+		const char *url_host = url + u.field_data[UF_HOST].off;
+		size_t url_host_len = u.field_data[UF_HOST].len;
+		git_buf_decode_percent(&host, url_host, url_host_len);
+	}
+
+	if (has_port) {
+		const char *url_port = url + u.field_data[UF_PORT].off;
+		size_t url_port_len = u.field_data[UF_PORT].len;
+		git_buf_put(&port, url_port, url_port_len);
+	} else {
+		git_buf_puts(&port, default_port);
+	}
+
+	if (has_path && path_out) {
+		const char *url_path = url + u.field_data[UF_PATH].off;
+		size_t url_path_len = u.field_data[UF_PATH].len;
+		git_buf_decode_percent(&path, url_path, url_path_len);
+	} else if (path_out) {
+		giterr_set(GITERR_NET, "invalid url, missing path");
+		error = GIT_EINVALIDSPEC;
+		goto done;
+	}
+
+	if (has_userinfo) {
+		const char *url_userinfo = url + u.field_data[UF_USERINFO].off;
+		size_t url_userinfo_len = u.field_data[UF_USERINFO].len;
+		const char *colon = memchr(url_userinfo, ':', url_userinfo_len);
+
+		if (colon) {
+			const char *url_username = url_userinfo;
+			size_t url_username_len = colon - url_userinfo;
+			const char *url_password = colon + 1;
+			size_t url_password_len = url_userinfo_len - (url_username_len + 1);
+
+			git_buf_decode_percent(&username, url_username, url_username_len);
+			git_buf_decode_percent(&password, url_password, url_password_len);
+		} else {
+			git_buf_decode_percent(&username, url_userinfo, url_userinfo_len);
+		}
+	}
+
+	if (git_buf_oom(&host) ||
+		git_buf_oom(&port) ||
+		git_buf_oom(&path) ||
+		git_buf_oom(&username) ||
+		git_buf_oom(&password))
+		return -1;
+
+	*host_out = git_buf_detach(&host);
+	*port_out = git_buf_detach(&port);
+	if (path_out)
+		*path_out = git_buf_detach(&path);
+	*username_out = git_buf_detach(&username);
+	*password_out = git_buf_detach(&password);
+
+done:
+	git_buf_free(&host);
+	git_buf_free(&port);
+	git_buf_free(&path);
+	git_buf_free(&username);
+	git_buf_free(&password);
+	return error;
+}

vendor/libgit2-sys/libgit2/src/netops.h

diff --git a/vendor/libgit2-sys/libgit2/src/netops.h b/vendor/libgit2-sys/libgit2/src/netops.h
new file mode 100644
index 0000000..75fd9a5
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/netops.h
@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_netops_h__
+#define INCLUDE_netops_h__
+
+#include "common.h"
+
+#include "posix.h"
+#include "stream.h"
+
+#ifdef GIT_OPENSSL
+# include <openssl/ssl.h>
+#endif
+
+typedef struct gitno_ssl {
+#ifdef GIT_OPENSSL
+	SSL *ssl;
+#else
+	size_t dummy;
+#endif
+} gitno_ssl;
+
+/* Represents a socket that may or may not be using SSL */
+typedef struct gitno_socket {
+	GIT_SOCKET socket;
+	gitno_ssl ssl;
+} gitno_socket;
+
+typedef struct gitno_buffer {
+	char *data;
+	size_t len;
+	size_t offset;
+	int (*recv)(struct gitno_buffer *buffer);
+	void *cb_data;
+} gitno_buffer;
+
+/* Flags to gitno_connect */
+enum {
+	/* Attempt to create an SSL connection. */
+	GITNO_CONNECT_SSL = 1,
+};
+
+/**
+ * Check if the name in a cert matches the wanted hostname
+ *
+ * Check if a pattern from a certificate matches the hostname we
+ * wanted to connect to according to RFC2818 rules (which specifies
+ * HTTP over TLS). Mainly, an asterisk matches anything, but is
+ * limited to a single url component.
+ *
+ * Note that this does not set an error message. It expects the user
+ * to provide the message for the user.
+ */
+int gitno__match_host(const char *pattern, const char *host);
+
+void gitno_buffer_setup_fromstream(git_stream *st, gitno_buffer *buf, char *data, size_t len);
+void gitno_buffer_setup_callback(gitno_buffer *buf, char *data, size_t len, int (*recv)(gitno_buffer *buf), void *cb_data);
+int gitno_recv(gitno_buffer *buf);
+
+void gitno_consume(gitno_buffer *buf, const char *ptr);
+void gitno_consume_n(gitno_buffer *buf, size_t cons);
+
+typedef struct gitno_connection_data {
+	char *host;
+	char *port;
+	char *path;
+	char *user;
+	char *pass;
+	bool use_ssl;
+} gitno_connection_data;
+
+/*
+ * This replaces all the pointers in `data` with freshly-allocated strings,
+ * that the caller is responsible for freeing.
+ * `gitno_connection_data_free_ptrs` is good for this.
+ */
+
+int gitno_connection_data_from_url(
+		gitno_connection_data *data,
+		const char *url,
+		const char *service_suffix);
+
+/* This frees all the pointers IN the struct, but not the struct itself. */
+void gitno_connection_data_free_ptrs(gitno_connection_data *data);
+
+int gitno_extract_url_parts(
+		char **host,
+		char **port,
+		char **path,
+		char **username,
+		char **password,
+		const char *url,
+		const char *default_port);
+
+#endif

vendor/libgit2-sys/libgit2/src/notes.c

diff --git a/vendor/libgit2-sys/libgit2/src/notes.c b/vendor/libgit2-sys/libgit2/src/notes.c
new file mode 100644
index 0000000..f63ef36
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/notes.c
@@ -0,0 +1,810 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "notes.h"
+
+#include "git2.h"
+#include "refs.h"
+#include "config.h"
+#include "iterator.h"
+#include "signature.h"
+
+static int note_error_notfound(void)
+{
+	giterr_set(GITERR_INVALID, "note could not be found");
+	return GIT_ENOTFOUND;
+}
+
+static int find_subtree_in_current_level(
+	git_tree **out,
+	git_repository *repo,
+	git_tree *parent,
+	const char *annotated_object_sha,
+	int fanout)
+{
+	size_t i;
+	const git_tree_entry *entry;
+
+	*out = NULL;
+
+	if (parent == NULL)
+		return note_error_notfound();
+
+	for (i = 0; i < git_tree_entrycount(parent); i++) {
+		entry = git_tree_entry_byindex(parent, i);
+
+		if (!git__ishex(git_tree_entry_name(entry)))
+			continue;
+
+		if (S_ISDIR(git_tree_entry_filemode(entry))
+			&& strlen(git_tree_entry_name(entry)) == 2
+			&& !strncmp(git_tree_entry_name(entry), annotated_object_sha + fanout, 2))
+			return git_tree_lookup(out, repo, git_tree_entry_id(entry));
+
+		/* Not a DIR, so do we have an already existing blob? */
+		if (!strcmp(git_tree_entry_name(entry), annotated_object_sha + fanout))
+			return GIT_EEXISTS;
+	}
+
+	return note_error_notfound();
+}
+
+static int find_subtree_r(git_tree **out, git_tree *root,
+			git_repository *repo, const char *target, int *fanout)
+{
+	int error;
+	git_tree *subtree = NULL;
+
+	*out = NULL;
+
+	error = find_subtree_in_current_level(&subtree, repo, root, target, *fanout);
+	if (error == GIT_EEXISTS)
+		return git_tree_lookup(out, repo, git_tree_id(root));
+
+	if (error < 0)
+		return error;
+
+	*fanout += 2;
+	error = find_subtree_r(out, subtree, repo, target, fanout);
+	git_tree_free(subtree);
+
+	return error;
+}
+
+static int find_blob(git_oid *blob, git_tree *tree, const char *target)
+{
+	size_t i;
+	const git_tree_entry *entry;
+
+	for (i=0; i<git_tree_entrycount(tree); i++) {
+		entry = git_tree_entry_byindex(tree, i);
+
+		if (!strcmp(git_tree_entry_name(entry), target)) {
+			/* found matching note object - return */
+
+			git_oid_cpy(blob, git_tree_entry_id(entry));
+			return 0;
+		}
+	}
+
+	return note_error_notfound();
+}
+
+static int tree_write(
+	git_tree **out,
+	git_repository *repo,
+	git_tree *source_tree,
+	const git_oid *object_oid,
+	const char *treeentry_name,
+	unsigned int attributes)
+{
+	int error;
+	git_treebuilder *tb = NULL;
+	const git_tree_entry *entry;
+	git_oid tree_oid;
+
+	if ((error = git_treebuilder_new(&tb, repo, source_tree)) < 0)
+		goto cleanup;
+
+	if (object_oid) {
+		if ((error = git_treebuilder_insert(
+				&entry, tb, treeentry_name, object_oid, attributes)) < 0)
+			goto cleanup;
+	} else {
+		if ((error = git_treebuilder_remove(tb, treeentry_name)) < 0)
+			goto cleanup;
+	}
+
+	if ((error = git_treebuilder_write(&tree_oid, tb)) < 0)
+		goto cleanup;
+
+	error = git_tree_lookup(out, repo, &tree_oid);
+
+cleanup:
+	git_treebuilder_free(tb);
+	return error;
+}
+
+static int manipulate_note_in_tree_r(
+	git_tree **out,
+	git_repository *repo,
+	git_tree *parent,
+	git_oid *note_oid,
+	const char *annotated_object_sha,
+	int fanout,
+	int (*note_exists_cb)(
+		git_tree **out,
+		git_repository *repo,
+		git_tree *parent,
+		git_oid *note_oid,
+		const char *annotated_object_sha,
+		int fanout,
+		int current_error),
+	int (*note_notfound_cb)(
+		git_tree **out,
+		git_repository *repo,
+		git_tree *parent,
+		git_oid *note_oid,
+		const char *annotated_object_sha,
+		int fanout,
+		int current_error))
+{
+	int error;
+	git_tree *subtree = NULL, *new = NULL;
+	char subtree_name[3];
+
+	error = find_subtree_in_current_level(
+		&subtree, repo, parent, annotated_object_sha, fanout);
+
+	if (error == GIT_EEXISTS) {
+		error = note_exists_cb(
+			out, repo, parent, note_oid, annotated_object_sha, fanout, error);
+		goto cleanup;
+	}
+
+	if (error == GIT_ENOTFOUND) {
+		error = note_notfound_cb(
+			out, repo, parent, note_oid, annotated_object_sha, fanout, error);
+		goto cleanup;
+	}
+
+	if (error < 0)
+		goto cleanup;
+
+	/* An existing fanout has been found, let's dig deeper */
+	error = manipulate_note_in_tree_r(
+		&new, repo, subtree, note_oid, annotated_object_sha,
+		fanout + 2, note_exists_cb, note_notfound_cb);
+
+	if (error < 0)
+		goto cleanup;
+
+	strncpy(subtree_name, annotated_object_sha + fanout, 2);
+	subtree_name[2] = '\0';
+
+	error = tree_write(out, repo, parent, git_tree_id(new),
+			   subtree_name, GIT_FILEMODE_TREE);
+
+
+cleanup:
+	git_tree_free(new);
+	git_tree_free(subtree);
+	return error;
+}
+
+static int remove_note_in_tree_eexists_cb(
+	git_tree **out,
+	git_repository *repo,
+	git_tree *parent,
+	git_oid *note_oid,
+	const char *annotated_object_sha,
+	int fanout,
+	int current_error)
+{
+	GIT_UNUSED(note_oid);
+	GIT_UNUSED(current_error);
+
+	return tree_write(out, repo, parent, NULL, annotated_object_sha + fanout, 0);
+}
+
+static int remove_note_in_tree_enotfound_cb(
+	git_tree **out,
+	git_repository *repo,
+	git_tree *parent,
+	git_oid *note_oid,
+	const char *annotated_object_sha,
+	int fanout,
+	int current_error)
+{
+	GIT_UNUSED(out);
+	GIT_UNUSED(repo);
+	GIT_UNUSED(parent);
+	GIT_UNUSED(note_oid);
+	GIT_UNUSED(fanout);
+
+	giterr_set(GITERR_REPOSITORY, "object '%s' has no note", annotated_object_sha);
+	return current_error;
+}
+
+static int insert_note_in_tree_eexists_cb(git_tree **out,
+	git_repository *repo,
+	git_tree *parent,
+	git_oid *note_oid,
+	const char *annotated_object_sha,
+	int fanout,
+	int current_error)
+{
+	GIT_UNUSED(out);
+	GIT_UNUSED(repo);
+	GIT_UNUSED(parent);
+	GIT_UNUSED(note_oid);
+	GIT_UNUSED(fanout);
+
+	giterr_set(GITERR_REPOSITORY, "note for '%s' exists already", annotated_object_sha);
+	return current_error;
+}
+
+static int insert_note_in_tree_enotfound_cb(git_tree **out,
+	git_repository *repo,
+	git_tree *parent,
+	git_oid *note_oid,
+	const char *annotated_object_sha,
+	int fanout,
+	int current_error)
+{
+	GIT_UNUSED(current_error);
+
+	/* No existing fanout at this level, insert in place */
+	return tree_write(
+		out,
+		repo,
+		parent,
+		note_oid,
+		annotated_object_sha + fanout,
+		GIT_FILEMODE_BLOB);
+}
+
+static int note_write(
+	git_oid *notes_commit_out,
+	git_oid *notes_blob_out,
+	git_repository *repo,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *notes_ref,
+	const char *note,
+	git_tree *commit_tree,
+	const char *target,
+	git_commit **parents,
+	int allow_note_overwrite)
+{
+	int error;
+	git_oid oid;
+	git_tree *tree = NULL;
+
+	// TODO: should we apply filters?
+	/* create note object */
+	if ((error = git_blob_create_frombuffer(&oid, repo, note, strlen(note))) < 0)
+		goto cleanup;
+
+	if ((error = manipulate_note_in_tree_r(
+		&tree, repo, commit_tree, &oid, target, 0,
+		allow_note_overwrite ? insert_note_in_tree_enotfound_cb : insert_note_in_tree_eexists_cb,
+		insert_note_in_tree_enotfound_cb)) < 0)
+		goto cleanup;
+
+	if (notes_blob_out)
+		git_oid_cpy(notes_blob_out, &oid);
+
+
+	error = git_commit_create(&oid, repo, notes_ref, author, committer,
+				  NULL, GIT_NOTES_DEFAULT_MSG_ADD,
+				  tree, *parents == NULL ? 0 : 1, (const git_commit **) parents);
+
+	if (notes_commit_out)
+		git_oid_cpy(notes_commit_out, &oid);
+
+cleanup:
+	git_tree_free(tree);
+	return error;
+}
+
+static int note_new(
+	git_note **out,
+	git_oid *note_oid,
+	git_commit *commit,
+	git_blob *blob)
+{
+	git_note *note = NULL;
+
+	note = git__malloc(sizeof(git_note));
+	GITERR_CHECK_ALLOC(note);
+
+	git_oid_cpy(&note->id, note_oid);
+
+	if (git_signature_dup(&note->author, git_commit_author(commit)) < 0 ||
+		git_signature_dup(&note->committer, git_commit_committer(commit)) < 0)
+		return -1;
+
+	note->message = git__strndup(git_blob_rawcontent(blob), git_blob_rawsize(blob));
+	GITERR_CHECK_ALLOC(note->message);
+
+	*out = note;
+	return 0;
+}
+
+static int note_lookup(
+	git_note **out,
+	git_repository *repo,
+	git_commit *commit,
+	git_tree *tree,
+	const char *target)
+{
+	int error, fanout = 0;
+	git_oid oid;
+	git_blob *blob = NULL;
+	git_note *note = NULL;
+	git_tree *subtree = NULL;
+
+	if ((error = find_subtree_r(&subtree, tree, repo, target, &fanout)) < 0)
+		goto cleanup;
+
+	if ((error = find_blob(&oid, subtree, target + fanout)) < 0)
+		goto cleanup;
+
+	if ((error = git_blob_lookup(&blob, repo, &oid)) < 0)
+		goto cleanup;
+
+	if ((error = note_new(&note, &oid, commit, blob)) < 0)
+		goto cleanup;
+
+	*out = note;
+
+cleanup:
+	git_tree_free(subtree);
+	git_blob_free(blob);
+	return error;
+}
+
+static int note_remove(
+		git_oid *notes_commit_out,
+		git_repository *repo,
+		const git_signature *author, const git_signature *committer,
+		const char *notes_ref, git_tree *tree,
+		const char *target, git_commit **parents)
+{
+	int error;
+	git_tree *tree_after_removal = NULL;
+	git_oid oid;
+
+	if ((error = manipulate_note_in_tree_r(
+		&tree_after_removal, repo, tree, NULL, target, 0,
+		remove_note_in_tree_eexists_cb, remove_note_in_tree_enotfound_cb)) < 0)
+		goto cleanup;
+
+	error = git_commit_create(&oid, repo, notes_ref, author, committer,
+	  NULL, GIT_NOTES_DEFAULT_MSG_RM,
+	  tree_after_removal,
+	  *parents == NULL ? 0 : 1,
+	  (const git_commit **) parents);
+
+	if (error < 0)
+		goto cleanup;
+
+	if (notes_commit_out)
+		git_oid_cpy(notes_commit_out, &oid);
+
+cleanup:
+	git_tree_free(tree_after_removal);
+	return error;
+}
+
+static int note_get_default_ref(char **out, git_repository *repo)
+{
+	git_config *cfg;
+	int ret = git_repository_config__weakptr(&cfg, repo);
+
+	*out = (ret != 0) ? NULL : git_config__get_string_force(
+		cfg, "core.notesref", GIT_NOTES_DEFAULT_REF);
+
+	return ret;
+}
+
+static int normalize_namespace(char **out, git_repository *repo, const char *notes_ref)
+{
+	if (notes_ref) {
+		*out = git__strdup(notes_ref);
+		GITERR_CHECK_ALLOC(*out);
+		return 0;
+	}
+
+	return note_get_default_ref(out, repo);
+}
+
+static int retrieve_note_commit(
+	git_commit **commit_out,
+	char **notes_ref_out,
+	git_repository *repo,
+	const char *notes_ref)
+{
+	int error;
+	git_oid oid;
+
+	if ((error = normalize_namespace(notes_ref_out, repo, notes_ref)) < 0)
+		return error;
+
+	if ((error = git_reference_name_to_id(&oid, repo, *notes_ref_out)) < 0)
+		return error;
+
+	if (git_commit_lookup(commit_out, repo, &oid) < 0)
+		return error;
+
+	return 0;
+}
+
+int git_note_commit_read(
+	git_note **out,
+	git_repository *repo,
+	git_commit *notes_commit,
+	const git_oid *oid)
+{
+	int error;
+	git_tree *tree = NULL;
+	char target[GIT_OID_HEXSZ + 1];
+
+	git_oid_tostr(target, sizeof(target), oid);
+
+	if ((error = git_commit_tree(&tree, notes_commit)) < 0)
+		goto cleanup;
+
+	error = note_lookup(out, repo, notes_commit, tree, target);
+
+cleanup:
+	git_tree_free(tree);
+	return error;
+}
+
+int git_note_read(git_note **out, git_repository *repo,
+		  const char *notes_ref_in, const git_oid *oid)
+{
+	int error;
+	char *notes_ref = NULL;
+	git_commit *commit = NULL;
+
+	error = retrieve_note_commit(&commit, &notes_ref, repo, notes_ref_in);
+
+	if (error < 0)
+		goto cleanup;
+
+	error = git_note_commit_read(out, repo, commit, oid);
+
+cleanup:
+	git__free(notes_ref);
+	git_commit_free(commit);
+	return error;
+}
+
+int git_note_commit_create(
+	git_oid *notes_commit_out,
+	git_oid *notes_blob_out,
+	git_repository *repo,
+	git_commit *parent,
+	const git_signature *author,
+	const git_signature *committer,
+	const git_oid *oid,
+	const char *note,
+	int allow_note_overwrite)
+{
+	int error;
+	git_tree *tree = NULL;
+	char target[GIT_OID_HEXSZ + 1];
+
+	git_oid_tostr(target, sizeof(target), oid);
+
+	if (parent != NULL && (error = git_commit_tree(&tree, parent)) < 0)
+		goto cleanup;
+
+	error = note_write(notes_commit_out, notes_blob_out, repo, author,
+			committer, NULL, note, tree, target, &parent, allow_note_overwrite);
+
+	if (error < 0)
+		goto cleanup;
+
+cleanup:
+	git_tree_free(tree);
+	return error;
+}
+
+int git_note_create(
+	git_oid *out,
+	git_repository *repo,
+	const char *notes_ref_in,
+	const git_signature *author,
+	const git_signature *committer,
+	const git_oid *oid,
+	const char *note,
+	int allow_note_overwrite)
+{
+	int error;
+	char *notes_ref = NULL;
+	git_commit *existing_notes_commit = NULL;
+	git_reference *ref = NULL;
+	git_oid notes_blob_oid, notes_commit_oid;
+
+	error = retrieve_note_commit(&existing_notes_commit, &notes_ref,
+			repo, notes_ref_in);
+
+	if (error < 0 && error != GIT_ENOTFOUND)
+		goto cleanup;
+
+	error = git_note_commit_create(&notes_commit_oid,
+			&notes_blob_oid,
+			repo, existing_notes_commit, author,
+			committer, oid, note,
+			allow_note_overwrite);
+	if (error < 0)
+		goto cleanup;
+
+	error = git_reference_create(&ref, repo, notes_ref,
+				&notes_commit_oid, 1, NULL);
+
+	if (out != NULL)
+		git_oid_cpy(out, &notes_blob_oid);
+
+cleanup:
+	git__free(notes_ref);
+	git_commit_free(existing_notes_commit);
+	git_reference_free(ref);
+	return error;
+}
+
+int git_note_commit_remove(
+		git_oid *notes_commit_out,
+		git_repository *repo,
+		git_commit *notes_commit,
+		const git_signature *author,
+		const git_signature *committer,
+		const git_oid *oid)
+{
+	int error;
+	git_tree *tree = NULL;
+	char target[GIT_OID_HEXSZ + 1];
+
+	git_oid_tostr(target, sizeof(target), oid);
+
+	if ((error = git_commit_tree(&tree, notes_commit)) < 0)
+		goto cleanup;
+
+	error = note_remove(notes_commit_out,
+		repo, author, committer, NULL, tree, target, &notes_commit);
+
+cleanup:
+	git_tree_free(tree);
+	return error;
+}
+
+int git_note_remove(git_repository *repo, const char *notes_ref_in,
+		const git_signature *author, const git_signature *committer,
+		const git_oid *oid)
+{
+	int error;
+	char *notes_ref_target = NULL;
+	git_commit *existing_notes_commit = NULL;
+	git_oid new_notes_commit;
+	git_reference *notes_ref = NULL;
+
+	error = retrieve_note_commit(&existing_notes_commit, &notes_ref_target,
+			repo, notes_ref_in);
+
+	if (error < 0)
+		goto cleanup;
+
+	error = git_note_commit_remove(&new_notes_commit, repo,
+			existing_notes_commit, author, committer, oid);
+	if (error < 0)
+		goto cleanup;
+
+	error = git_reference_create(&notes_ref, repo, notes_ref_target,
+			&new_notes_commit, 1, NULL);
+
+cleanup:
+	git__free(notes_ref_target);
+	git_reference_free(notes_ref);
+	git_commit_free(existing_notes_commit);
+	return error;
+}
+
+int git_note_default_ref(git_buf *out, git_repository *repo)
+{
+	char *default_ref;
+	int error;
+
+	assert(out && repo);
+
+	git_buf_sanitize(out);
+
+	if ((error = note_get_default_ref(&default_ref, repo)) < 0)
+		return error;
+
+	git_buf_attach(out, default_ref, strlen(default_ref));
+	return 0;
+}
+
+const git_signature *git_note_committer(const git_note *note)
+{
+	assert(note);
+	return note->committer;
+}
+
+const git_signature *git_note_author(const git_note *note)
+{
+	assert(note);
+	return note->author;
+}
+
+const char * git_note_message(const git_note *note)
+{
+	assert(note);
+	return note->message;
+}
+
+const git_oid * git_note_id(const git_note *note)
+{
+	assert(note);
+	return &note->id;
+}
+
+void git_note_free(git_note *note)
+{
+	if (note == NULL)
+		return;
+
+	git_signature_free(note->committer);
+	git_signature_free(note->author);
+	git__free(note->message);
+	git__free(note);
+}
+
+static int process_entry_path(
+	const char* entry_path,
+	git_oid *annotated_object_id)
+{
+	int error = 0;
+	size_t i = 0, j = 0, len;
+	git_buf buf = GIT_BUF_INIT;
+
+	if ((error = git_buf_puts(&buf, entry_path)) < 0)
+		goto cleanup;
+
+	len = git_buf_len(&buf);
+
+	while (i < len) {
+		if (buf.ptr[i] == '/') {
+			i++;
+			continue;
+		}
+
+		if (git__fromhex(buf.ptr[i]) < 0) {
+			/* This is not a note entry */
+			goto cleanup;
+		}
+
+		if (i != j)
+			buf.ptr[j] = buf.ptr[i];
+
+		i++;
+		j++;
+	}
+
+	buf.ptr[j] = '\0';
+	buf.size = j;
+
+	if (j != GIT_OID_HEXSZ) {
+		/* This is not a note entry */
+		goto cleanup;
+	}
+
+	error = git_oid_fromstr(annotated_object_id, buf.ptr);
+
+cleanup:
+	git_buf_free(&buf);
+	return error;
+}
+
+int git_note_foreach(
+	git_repository *repo,
+	const char *notes_ref,
+	git_note_foreach_cb note_cb,
+	void *payload)
+{
+	int error;
+	git_note_iterator *iter = NULL;
+	git_oid note_id, annotated_id;
+
+	if ((error = git_note_iterator_new(&iter, repo, notes_ref)) < 0)
+		return error;
+
+	while (!(error = git_note_next(&note_id, &annotated_id, iter))) {
+		if ((error = note_cb(&note_id, &annotated_id, payload)) != 0) {
+			giterr_set_after_callback(error);
+			break;
+		}
+	}
+
+	if (error == GIT_ITEROVER)
+		error = 0;
+
+	git_note_iterator_free(iter);
+	return error;
+}
+
+void git_note_iterator_free(git_note_iterator *it)
+{
+	if (it == NULL)
+		return;
+
+	git_iterator_free(it);
+}
+
+int git_note_commit_iterator_new(
+	git_note_iterator **it,
+	git_commit *notes_commit)
+{
+	int error;
+	git_tree *tree;
+
+	if ((error = git_commit_tree(&tree, notes_commit)) < 0)
+		goto cleanup;
+
+	if ((error = git_iterator_for_tree(it, tree, NULL)) < 0)
+		git_iterator_free(*it);
+
+cleanup:
+	git_tree_free(tree);
+
+	return error;
+}
+
+int git_note_iterator_new(
+	git_note_iterator **it,
+	git_repository *repo,
+	const char *notes_ref_in)
+{
+	int error;
+	git_commit *commit = NULL;
+	char *notes_ref;
+
+	error = retrieve_note_commit(&commit, &notes_ref, repo, notes_ref_in);
+	if (error < 0)
+		goto cleanup;
+
+	error = git_note_commit_iterator_new(it, commit);
+
+cleanup:
+	git__free(notes_ref);
+	git_commit_free(commit);
+
+	return error;
+}
+
+int git_note_next(
+	git_oid* note_id,
+	git_oid* annotated_id,
+	git_note_iterator *it)
+{
+	int error;
+	const git_index_entry *item;
+
+	if ((error = git_iterator_current(&item, it)) < 0)
+		return error;
+
+	git_oid_cpy(note_id, &item->id);
+
+	if (!(error = process_entry_path(item->path, annotated_id)))
+		git_iterator_advance(NULL, it);
+
+	return error;
+}

vendor/libgit2-sys/libgit2/src/notes.h

diff --git a/vendor/libgit2-sys/libgit2/src/notes.h b/vendor/libgit2-sys/libgit2/src/notes.h
new file mode 100644
index 0000000..2168e45
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/notes.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_note_h__
+#define INCLUDE_note_h__
+
+#include "common.h"
+
+#include "git2/oid.h"
+#include "git2/types.h"
+
+#define GIT_NOTES_DEFAULT_REF "refs/notes/commits"
+
+#define GIT_NOTES_DEFAULT_MSG_ADD \
+	"Notes added by 'git_note_create' from libgit2"
+
+#define GIT_NOTES_DEFAULT_MSG_RM \
+	"Notes removed by 'git_note_remove' from libgit2"
+
+struct git_note {
+	git_oid id;
+
+	git_signature *author;
+	git_signature *committer;
+
+	char *message;
+};
+
+#endif

vendor/libgit2-sys/libgit2/src/object.c

diff --git a/vendor/libgit2-sys/libgit2/src/object.c b/vendor/libgit2-sys/libgit2/src/object.c
new file mode 100644
index 0000000..48f5613
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/object.c
@@ -0,0 +1,501 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "object.h"
+
+#include "git2/object.h"
+
+#include "repository.h"
+
+#include "commit.h"
+#include "tree.h"
+#include "blob.h"
+#include "oid.h"
+#include "tag.h"
+
+bool git_object__strict_input_validation = true;
+
+typedef struct {
+	const char	*str;	/* type name string */
+	size_t		size;	/* size in bytes of the object structure */
+
+	int  (*parse)(void *self, git_odb_object *obj);
+	void (*free)(void *self);
+} git_object_def;
+
+static git_object_def git_objects_table[] = {
+	/* 0 = GIT_OBJ__EXT1 */
+	{ "", 0, NULL, NULL },
+
+	/* 1 = GIT_OBJ_COMMIT */
+	{ "commit", sizeof(git_commit), git_commit__parse, git_commit__free },
+
+	/* 2 = GIT_OBJ_TREE */
+	{ "tree", sizeof(git_tree), git_tree__parse, git_tree__free },
+
+	/* 3 = GIT_OBJ_BLOB */
+	{ "blob", sizeof(git_blob), git_blob__parse, git_blob__free },
+
+	/* 4 = GIT_OBJ_TAG */
+	{ "tag", sizeof(git_tag), git_tag__parse, git_tag__free },
+
+	/* 5 = GIT_OBJ__EXT2 */
+	{ "", 0, NULL, NULL },
+	/* 6 = GIT_OBJ_OFS_DELTA */
+	{ "OFS_DELTA", 0, NULL, NULL },
+	/* 7 = GIT_OBJ_REF_DELTA */
+	{ "REF_DELTA", 0, NULL, NULL },
+};
+
+int git_object__from_odb_object(
+	git_object **object_out,
+	git_repository *repo,
+	git_odb_object *odb_obj,
+	git_otype type)
+{
+	int error;
+	size_t object_size;
+	git_object_def *def;
+	git_object *object = NULL;
+
+	assert(object_out);
+	*object_out = NULL;
+
+	/* Validate type match */
+	if (type != GIT_OBJ_ANY && type != odb_obj->cached.type) {
+		giterr_set(GITERR_INVALID,
+			"the requested type does not match the type in the ODB");
+		return GIT_ENOTFOUND;
+	}
+
+	if ((object_size = git_object__size(odb_obj->cached.type)) == 0) {
+		giterr_set(GITERR_INVALID, "the requested type is invalid");
+		return GIT_ENOTFOUND;
+	}
+
+	/* Allocate and initialize base object */
+	object = git__calloc(1, object_size);
+	GITERR_CHECK_ALLOC(object);
+
+	git_oid_cpy(&object->cached.oid, &odb_obj->cached.oid);
+	object->cached.type = odb_obj->cached.type;
+	object->cached.size = odb_obj->cached.size;
+	object->repo = repo;
+
+	/* Parse raw object data */
+	def = &git_objects_table[odb_obj->cached.type];
+	assert(def->free && def->parse);
+
+	if ((error = def->parse(object, odb_obj)) < 0)
+		def->free(object);
+	else
+		*object_out = git_cache_store_parsed(&repo->objects, object);
+
+	return error;
+}
+
+void git_object__free(void *obj)
+{
+	git_otype type = ((git_object *)obj)->cached.type;
+
+	if (type < 0 || ((size_t)type) >= ARRAY_SIZE(git_objects_table) ||
+		!git_objects_table[type].free)
+		git__free(obj);
+	else
+		git_objects_table[type].free(obj);
+}
+
+int git_object_lookup_prefix(
+	git_object **object_out,
+	git_repository *repo,
+	const git_oid *id,
+	size_t len,
+	git_otype type)
+{
+	git_object *object = NULL;
+	git_odb *odb = NULL;
+	git_odb_object *odb_obj = NULL;
+	int error = 0;
+
+	assert(repo && object_out && id);
+
+	if (len < GIT_OID_MINPREFIXLEN) {
+		giterr_set(GITERR_OBJECT, "ambiguous lookup - OID prefix is too short");
+		return GIT_EAMBIGUOUS;
+	}
+
+	error = git_repository_odb__weakptr(&odb, repo);
+	if (error < 0)
+		return error;
+
+	if (len > GIT_OID_HEXSZ)
+		len = GIT_OID_HEXSZ;
+
+	if (len == GIT_OID_HEXSZ) {
+		git_cached_obj *cached = NULL;
+
+		/* We want to match the full id : we can first look up in the cache,
+		 * since there is no need to check for non ambiguousity
+		 */
+		cached = git_cache_get_any(&repo->objects, id);
+		if (cached != NULL) {
+			if (cached->flags == GIT_CACHE_STORE_PARSED) {
+				object = (git_object *)cached;
+
+				if (type != GIT_OBJ_ANY && type != object->cached.type) {
+					git_object_free(object);
+					giterr_set(GITERR_INVALID,
+						"the requested type does not match the type in ODB");
+					return GIT_ENOTFOUND;
+				}
+
+				*object_out = object;
+				return 0;
+			} else if (cached->flags == GIT_CACHE_STORE_RAW) {
+				odb_obj = (git_odb_object *)cached;
+			} else {
+				assert(!"Wrong caching type in the global object cache");
+			}
+		} else {
+			/* Object was not found in the cache, let's explore the backends.
+			 * We could just use git_odb_read_unique_short_oid,
+			 * it is the same cost for packed and loose object backends,
+			 * but it may be much more costly for sqlite and hiredis.
+			 */
+			error = git_odb_read(&odb_obj, odb, id);
+		}
+	} else {
+		git_oid short_oid = {{ 0 }};
+
+		git_oid__cpy_prefix(&short_oid, id, len);
+
+		/* If len < GIT_OID_HEXSZ (a strict short oid was given), we have
+		 * 2 options :
+		 * - We always search in the cache first. If we find that short oid is
+		 *	ambiguous, we can stop. But in all the other cases, we must then
+		 *	explore all the backends (to find an object if there was match,
+		 *	or to check that oid is not ambiguous if we have found 1 match in
+		 *	the cache)
+		 * - We never explore the cache, go right to exploring the backends
+		 * We chose the latter : we explore directly the backends.
+		 */
+		error = git_odb_read_prefix(&odb_obj, odb, &short_oid, len);
+	}
+
+	if (error < 0)
+		return error;
+
+	error = git_object__from_odb_object(object_out, repo, odb_obj, type);
+
+	git_odb_object_free(odb_obj);
+
+	return error;
+}
+
+int git_object_lookup(git_object **object_out, git_repository *repo, const git_oid *id, git_otype type) {
+	return git_object_lookup_prefix(object_out, repo, id, GIT_OID_HEXSZ, type);
+}
+
+void git_object_free(git_object *object)
+{
+	if (object == NULL)
+		return;
+
+	git_cached_obj_decref(object);
+}
+
+const git_oid *git_object_id(const git_object *obj)
+{
+	assert(obj);
+	return &obj->cached.oid;
+}
+
+git_otype git_object_type(const git_object *obj)
+{
+	assert(obj);
+	return obj->cached.type;
+}
+
+git_repository *git_object_owner(const git_object *obj)
+{
+	assert(obj);
+	return obj->repo;
+}
+
+const char *git_object_type2string(git_otype type)
+{
+	if (type < 0 || ((size_t) type) >= ARRAY_SIZE(git_objects_table))
+		return "";
+
+	return git_objects_table[type].str;
+}
+
+git_otype git_object_string2type(const char *str)
+{
+	if (!str)
+		return GIT_OBJ_BAD;
+
+	return git_object_stringn2type(str, strlen(str));
+}
+
+git_otype git_object_stringn2type(const char *str, size_t len)
+{
+	size_t i;
+
+	if (!str || !len || !*str)
+		return GIT_OBJ_BAD;
+
+	for (i = 0; i < ARRAY_SIZE(git_objects_table); i++)
+		if (*git_objects_table[i].str &&
+			!git__prefixncmp(str, len, git_objects_table[i].str))
+			return (git_otype)i;
+
+	return GIT_OBJ_BAD;
+}
+
+int git_object_typeisloose(git_otype type)
+{
+	if (type < 0 || ((size_t) type) >= ARRAY_SIZE(git_objects_table))
+		return 0;
+
+	return (git_objects_table[type].size > 0) ? 1 : 0;
+}
+
+size_t git_object__size(git_otype type)
+{
+	if (type < 0 || ((size_t) type) >= ARRAY_SIZE(git_objects_table))
+		return 0;
+
+	return git_objects_table[type].size;
+}
+
+static int dereference_object(git_object **dereferenced, git_object *obj)
+{
+	git_otype type = git_object_type(obj);
+
+	switch (type) {
+	case GIT_OBJ_COMMIT:
+		return git_commit_tree((git_tree **)dereferenced, (git_commit*)obj);
+
+	case GIT_OBJ_TAG:
+		return git_tag_target(dereferenced, (git_tag*)obj);
+
+	case GIT_OBJ_BLOB:
+	case GIT_OBJ_TREE:
+		return GIT_EPEEL;
+
+	default:
+		return GIT_EINVALIDSPEC;
+	}
+}
+
+static int peel_error(int error, const git_oid *oid, git_otype type)
+{
+	const char *type_name;
+	char hex_oid[GIT_OID_HEXSZ + 1];
+
+	type_name = git_object_type2string(type);
+
+	git_oid_fmt(hex_oid, oid);
+	hex_oid[GIT_OID_HEXSZ] = '\0';
+
+	giterr_set(GITERR_OBJECT, "the git_object of id '%s' can not be "
+		"successfully peeled into a %s (git_otype=%i).", hex_oid, type_name, type);
+
+	return error;
+}
+
+static int check_type_combination(git_otype type, git_otype target)
+{
+	if (type == target)
+		return 0;
+
+	switch (type) {
+	case GIT_OBJ_BLOB:
+	case GIT_OBJ_TREE:
+		/* a blob or tree can never be peeled to anything but themselves */
+		return GIT_EINVALIDSPEC;
+		break;
+	case GIT_OBJ_COMMIT:
+		/* a commit can only be peeled to a tree */
+		if (target != GIT_OBJ_TREE && target != GIT_OBJ_ANY)
+			return GIT_EINVALIDSPEC;
+		break;
+	case GIT_OBJ_TAG:
+		/* a tag may point to anything, so we let anything through */
+		break;
+	default:
+		return GIT_EINVALIDSPEC;
+	}
+
+	return 0;
+}
+
+int git_object_peel(
+	git_object **peeled,
+	const git_object *object,
+	git_otype target_type)
+{
+	git_object *source, *deref = NULL;
+	int error;
+
+	assert(object && peeled);
+
+	assert(target_type == GIT_OBJ_TAG ||
+		target_type == GIT_OBJ_COMMIT ||
+		target_type == GIT_OBJ_TREE ||
+		target_type == GIT_OBJ_BLOB ||
+		target_type == GIT_OBJ_ANY);
+
+	if ((error = check_type_combination(git_object_type(object), target_type)) < 0)
+		return peel_error(error, git_object_id(object), target_type);
+
+	if (git_object_type(object) == target_type)
+		return git_object_dup(peeled, (git_object *)object);
+
+	source = (git_object *)object;
+
+	while (!(error = dereference_object(&deref, source))) {
+
+		if (source != object)
+			git_object_free(source);
+
+		if (git_object_type(deref) == target_type) {
+			*peeled = deref;
+			return 0;
+		}
+
+		if (target_type == GIT_OBJ_ANY &&
+			git_object_type(deref) != git_object_type(object))
+		{
+			*peeled = deref;
+			return 0;
+		}
+
+		source = deref;
+		deref = NULL;
+	}
+
+	if (source != object)
+		git_object_free(source);
+
+	git_object_free(deref);
+
+	if (error)
+		error = peel_error(error, git_object_id(object), target_type);
+
+	return error;
+}
+
+int git_object_dup(git_object **dest, git_object *source)
+{
+	git_cached_obj_incref(source);
+	*dest = source;
+	return 0;
+}
+
+int git_object_lookup_bypath(
+		git_object **out,
+		const git_object *treeish,
+		const char *path,
+		git_otype type)
+{
+	int error = -1;
+	git_tree *tree = NULL;
+	git_tree_entry *entry = NULL;
+
+	assert(out && treeish && path);
+
+	if ((error = git_object_peel((git_object**)&tree, treeish, GIT_OBJ_TREE)) < 0 ||
+		 (error = git_tree_entry_bypath(&entry, tree, path)) < 0)
+	{
+		goto cleanup;
+	}
+
+	if (type != GIT_OBJ_ANY && git_tree_entry_type(entry) != type)
+	{
+		giterr_set(GITERR_OBJECT,
+				"object at path '%s' is not of the asked-for type %d",
+				path, type);
+		error = GIT_EINVALIDSPEC;
+		goto cleanup;
+	}
+
+	error = git_tree_entry_to_object(out, git_object_owner(treeish), entry);
+
+cleanup:
+	git_tree_entry_free(entry);
+	git_tree_free(tree);
+	return error;
+}
+
+int git_object_short_id(git_buf *out, const git_object *obj)
+{
+	git_repository *repo;
+	int len = GIT_ABBREV_DEFAULT, error;
+	git_oid id = {{0}};
+	git_odb *odb;
+
+	assert(out && obj);
+
+	git_buf_sanitize(out);
+	repo = git_object_owner(obj);
+
+	if ((error = git_repository__cvar(&len, repo, GIT_CVAR_ABBREV)) < 0)
+		return error;
+
+	if ((error = git_repository_odb(&odb, repo)) < 0)
+		return error;
+
+	while (len < GIT_OID_HEXSZ) {
+		/* set up short oid */
+		memcpy(&id.id, &obj->cached.oid.id, (len + 1) / 2);
+		if (len & 1)
+			id.id[len / 2] &= 0xf0;
+
+		error = git_odb_exists_prefix(NULL, odb, &id, len);
+		if (error != GIT_EAMBIGUOUS)
+			break;
+
+		giterr_clear();
+		len++;
+	}
+
+	if (!error && !(error = git_buf_grow(out, len + 1))) {
+		git_oid_tostr(out->ptr, len + 1, &id);
+		out->size = len;
+	}
+
+	git_odb_free(odb);
+
+	return error;
+}
+
+bool git_object__is_valid(
+	git_repository *repo, const git_oid *id, git_otype expected_type)
+{
+	git_odb *odb;
+	git_otype actual_type;
+	size_t len;
+	int error;
+
+	if (!git_object__strict_input_validation)
+		return true;
+
+	if ((error = git_repository_odb__weakptr(&odb, repo)) < 0 ||
+		(error = git_odb_read_header(&len, &actual_type, odb, id)) < 0)
+		return false;
+
+	if (expected_type != GIT_OBJ_ANY && expected_type != actual_type) {
+		giterr_set(GITERR_INVALID,
+			"the requested type does not match the type in the ODB");
+		return false;
+	}
+
+	return true;
+}
+

vendor/libgit2-sys/libgit2/src/object.h

diff --git a/vendor/libgit2-sys/libgit2/src/object.h b/vendor/libgit2-sys/libgit2/src/object.h
new file mode 100644
index 0000000..e46c9ca
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/object.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_object_h__
+#define INCLUDE_object_h__
+
+#include "common.h"
+
+#include "repository.h"
+
+extern bool git_object__strict_input_validation;
+
+/** Base git object for inheritance */
+struct git_object {
+	git_cached_obj cached;
+	git_repository *repo;
+};
+
+/* fully free the object; internal method, DO NOT EXPORT */
+void git_object__free(void *object);
+
+int git_object__from_odb_object(
+	git_object **object_out,
+	git_repository *repo,
+	git_odb_object *odb_obj,
+	git_otype type);
+
+int git_object__resolve_to_type(git_object **obj, git_otype type);
+
+git_otype git_object_stringn2type(const char *str, size_t len);
+
+int git_oid__parse(git_oid *oid, const char **buffer_out, const char *buffer_end, const char *header);
+
+void git_oid__writebuf(git_buf *buf, const char *header, const git_oid *oid);
+
+bool git_object__is_valid(
+	git_repository *repo, const git_oid *id, git_otype expected_type);
+
+GIT_INLINE(git_otype) git_object__type_from_filemode(git_filemode_t mode)
+{
+	switch (mode) {
+	case GIT_FILEMODE_TREE:
+		return GIT_OBJ_TREE;
+	case GIT_FILEMODE_COMMIT:
+		return GIT_OBJ_COMMIT;
+	case GIT_FILEMODE_BLOB:
+	case GIT_FILEMODE_BLOB_EXECUTABLE:
+	case GIT_FILEMODE_LINK:
+		return GIT_OBJ_BLOB;
+	default:
+		return GIT_OBJ_BAD;
+	}
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/object_api.c

diff --git a/vendor/libgit2-sys/libgit2/src/object_api.c b/vendor/libgit2-sys/libgit2/src/object_api.c
new file mode 100644
index 0000000..75efa4d
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/object_api.c
@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "git2/object.h"
+
+#include "repository.h"
+#include "commit.h"
+#include "tree.h"
+#include "blob.h"
+#include "tag.h"
+
+/**
+ * Commit
+ */
+int git_commit_lookup(git_commit **out, git_repository *repo, const git_oid *id)
+{
+	return git_object_lookup((git_object **)out, repo, id, GIT_OBJ_COMMIT);
+}
+
+int git_commit_lookup_prefix(git_commit **out, git_repository *repo, const git_oid *id, size_t len)
+{
+	return git_object_lookup_prefix((git_object **)out, repo, id, len, GIT_OBJ_COMMIT);
+}
+
+void git_commit_free(git_commit *obj)
+{
+	git_object_free((git_object *)obj);
+}
+
+const git_oid *git_commit_id(const git_commit *obj)
+{
+	return git_object_id((const git_object *)obj);
+}
+
+git_repository *git_commit_owner(const git_commit *obj)
+{
+	return git_object_owner((const git_object *)obj);
+}
+
+int git_commit_dup(git_commit **out, git_commit *obj)
+{
+	return git_object_dup((git_object **)out, (git_object *)obj);
+}
+
+/**
+ * Tree
+ */
+int git_tree_lookup(git_tree **out, git_repository *repo, const git_oid *id)
+{
+	return git_object_lookup((git_object **)out, repo, id, GIT_OBJ_TREE);
+}
+
+int git_tree_lookup_prefix(git_tree **out, git_repository *repo, const git_oid *id, size_t len)
+{
+	return git_object_lookup_prefix((git_object **)out, repo, id, len, GIT_OBJ_TREE);
+}
+
+void git_tree_free(git_tree *obj)
+{
+	git_object_free((git_object *)obj);
+}
+
+const git_oid *git_tree_id(const git_tree *obj)
+{
+	return git_object_id((const git_object *)obj);
+}
+
+git_repository *git_tree_owner(const git_tree *obj)
+{
+	return git_object_owner((const git_object *)obj);
+}
+
+int git_tree_dup(git_tree **out, git_tree *obj)
+{
+	return git_object_dup((git_object **)out, (git_object *)obj);
+}
+
+/**
+ * Tag
+ */
+int git_tag_lookup(git_tag **out, git_repository *repo, const git_oid *id)
+{
+	return git_object_lookup((git_object **)out, repo, id, GIT_OBJ_TAG);
+}
+
+int git_tag_lookup_prefix(git_tag **out, git_repository *repo, const git_oid *id, size_t len)
+{
+	return git_object_lookup_prefix((git_object **)out, repo, id, len, GIT_OBJ_TAG);
+}
+
+void git_tag_free(git_tag *obj)
+{
+	git_object_free((git_object *)obj);
+}
+
+const git_oid *git_tag_id(const git_tag *obj)
+{
+	return git_object_id((const git_object *)obj);
+}
+
+git_repository *git_tag_owner(const git_tag *obj)
+{
+	return git_object_owner((const git_object *)obj);
+}
+
+int git_tag_dup(git_tag **out, git_tag *obj)
+{
+	return git_object_dup((git_object **)out, (git_object *)obj);
+}
+
+/**
+ * Blob
+ */
+int git_blob_lookup(git_blob **out, git_repository *repo, const git_oid *id)
+{
+	return git_object_lookup((git_object **)out, repo, id, GIT_OBJ_BLOB);
+}
+
+int git_blob_lookup_prefix(git_blob **out, git_repository *repo, const git_oid *id, size_t len)
+{
+	return git_object_lookup_prefix((git_object **)out, repo, id, len, GIT_OBJ_BLOB);
+}
+
+void git_blob_free(git_blob *obj)
+{
+	git_object_free((git_object *)obj);
+}
+
+const git_oid *git_blob_id(const git_blob *obj)
+{
+	return git_object_id((const git_object *)obj);
+}
+
+git_repository *git_blob_owner(const git_blob *obj)
+{
+	return git_object_owner((const git_object *)obj);
+}
+
+int git_blob_dup(git_blob **out, git_blob *obj)
+{
+	return git_object_dup((git_object **)out, (git_object *)obj);
+}

vendor/libgit2-sys/libgit2/src/odb.c

diff --git a/vendor/libgit2-sys/libgit2/src/odb.c b/vendor/libgit2-sys/libgit2/src/odb.c
new file mode 100644
index 0000000..ef9c875
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/odb.c
@@ -0,0 +1,1564 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "odb.h"
+
+#include <zlib.h>
+#include "git2/object.h"
+#include "git2/sys/odb_backend.h"
+#include "fileops.h"
+#include "hash.h"
+#include "delta.h"
+#include "filter.h"
+#include "repository.h"
+
+#include "git2/odb_backend.h"
+#include "git2/oid.h"
+#include "git2/oidarray.h"
+
+#define GIT_ALTERNATES_FILE "info/alternates"
+
+/*
+ * We work under the assumption that most objects for long-running
+ * operations will be packed
+ */
+#define GIT_LOOSE_PRIORITY 1
+#define GIT_PACKED_PRIORITY 2
+
+#define GIT_ALTERNATES_MAX_DEPTH 5
+
+bool git_odb__strict_hash_verification = true;
+
+typedef struct
+{
+	git_odb_backend *backend;
+	int priority;
+	bool is_alternate;
+	ino_t disk_inode;
+} backend_internal;
+
+static git_cache *odb_cache(git_odb *odb)
+{
+	if (odb->rc.owner != NULL) {
+		git_repository *owner = odb->rc.owner;
+		return &owner->objects;
+	}
+
+	return &odb->own_cache;
+}
+
+static int odb_otype_fast(git_otype *type_p, git_odb *db, const git_oid *id);
+static int load_alternates(git_odb *odb, const char *objects_dir, int alternate_depth);
+static int error_null_oid(int error, const char *message);
+
+static git_otype odb_hardcoded_type(const git_oid *id)
+{
+	static git_oid empty_tree = {{ 0x4b, 0x82, 0x5d, 0xc6, 0x42, 0xcb, 0x6e, 0xb9, 0xa0, 0x60,
+					   0xe5, 0x4b, 0xf8, 0xd6, 0x92, 0x88, 0xfb, 0xee, 0x49, 0x04 }};
+
+	if (!git_oid_cmp(id, &empty_tree))
+		return GIT_OBJ_TREE;
+
+	return GIT_OBJ_BAD;
+}
+
+static int odb_read_hardcoded(bool *found, git_rawobj *raw, const git_oid *id)
+{
+	git_otype type;
+
+	*found = false;
+
+	if ((type = odb_hardcoded_type(id)) == GIT_OBJ_BAD)
+		return 0;
+
+	raw->type = type;
+	raw->len = 0;
+	raw->data = git__calloc(1, sizeof(uint8_t));
+	GITERR_CHECK_ALLOC(raw->data);
+
+	*found = true;
+	return 0;
+}
+
+int git_odb__format_object_header(
+	size_t *written,
+	char *hdr,
+	size_t hdr_size,
+	git_off_t obj_len,
+	git_otype obj_type)
+{
+	const char *type_str = git_object_type2string(obj_type);
+	int hdr_max = (hdr_size > INT_MAX-2) ? (INT_MAX-2) : (int)hdr_size;
+	int len;
+
+	len = p_snprintf(hdr, hdr_max, "%s %lld", type_str, (long long)obj_len);
+
+	if (len < 0 || len >= hdr_max) {
+		giterr_set(GITERR_OS, "object header creation failed");
+		return -1;
+	}
+
+	*written = (size_t)(len + 1);
+	return 0;
+}
+
+int git_odb__hashobj(git_oid *id, git_rawobj *obj)
+{
+	git_buf_vec vec[2];
+	char header[64];
+	size_t hdrlen;
+	int error;
+
+	assert(id && obj);
+
+	if (!git_object_typeisloose(obj->type)) {
+		giterr_set(GITERR_INVALID, "invalid object type");
+		return -1;
+	}
+
+	if (!obj->data && obj->len != 0) {
+		giterr_set(GITERR_INVALID, "invalid object");
+		return -1;
+	}
+
+	if ((error = git_odb__format_object_header(&hdrlen,
+		header, sizeof(header), obj->len, obj->type)) < 0)
+		return error;
+
+	vec[0].data = header;
+	vec[0].len = hdrlen;
+	vec[1].data = obj->data;
+	vec[1].len = obj->len;
+
+	return git_hash_vec(id, vec, 2);
+}
+
+
+static git_odb_object *odb_object__alloc(const git_oid *oid, git_rawobj *source)
+{
+	git_odb_object *object = git__calloc(1, sizeof(git_odb_object));
+
+	if (object != NULL) {
+		git_oid_cpy(&object->cached.oid, oid);
+		object->cached.type = source->type;
+		object->cached.size = source->len;
+		object->buffer      = source->data;
+	}
+
+	return object;
+}
+
+void git_odb_object__free(void *object)
+{
+	if (object != NULL) {
+		git__free(((git_odb_object *)object)->buffer);
+		git__free(object);
+	}
+}
+
+const git_oid *git_odb_object_id(git_odb_object *object)
+{
+	return &object->cached.oid;
+}
+
+const void *git_odb_object_data(git_odb_object *object)
+{
+	return object->buffer;
+}
+
+size_t git_odb_object_size(git_odb_object *object)
+{
+	return object->cached.size;
+}
+
+git_otype git_odb_object_type(git_odb_object *object)
+{
+	return object->cached.type;
+}
+
+int git_odb_object_dup(git_odb_object **dest, git_odb_object *source)
+{
+	git_cached_obj_incref(source);
+	*dest = source;
+	return 0;
+}
+
+void git_odb_object_free(git_odb_object *object)
+{
+	if (object == NULL)
+		return;
+
+	git_cached_obj_decref(object);
+}
+
+int git_odb__hashfd(git_oid *out, git_file fd, size_t size, git_otype type)
+{
+	size_t hdr_len;
+	char hdr[64], buffer[FILEIO_BUFSIZE];
+	git_hash_ctx ctx;
+	ssize_t read_len = 0;
+	int error = 0;
+
+	if (!git_object_typeisloose(type)) {
+		giterr_set(GITERR_INVALID, "invalid object type for hash");
+		return -1;
+	}
+
+	if ((error = git_hash_ctx_init(&ctx)) < 0)
+		return error;
+
+	if ((error = git_odb__format_object_header(&hdr_len, hdr,
+		sizeof(hdr), size, type)) < 0)
+		goto done;
+
+	if ((error = git_hash_update(&ctx, hdr, hdr_len)) < 0)
+		goto done;
+
+	while (size > 0 && (read_len = p_read(fd, buffer, sizeof(buffer))) > 0) {
+		if ((error = git_hash_update(&ctx, buffer, read_len)) < 0)
+			goto done;
+
+		size -= read_len;
+	}
+
+	/* If p_read returned an error code, the read obviously failed.
+	 * If size is not zero, the file was truncated after we originally
+	 * stat'd it, so we consider this a read failure too */
+	if (read_len < 0 || size > 0) {
+		giterr_set(GITERR_OS, "error reading file for hashing");
+		error = -1;
+
+		goto done;
+	}
+
+	error = git_hash_final(out, &ctx);
+
+done:
+	git_hash_ctx_cleanup(&ctx);
+	return error;
+}
+
+int git_odb__hashfd_filtered(
+	git_oid *out, git_file fd, size_t size, git_otype type, git_filter_list *fl)
+{
+	int error;
+	git_buf raw = GIT_BUF_INIT;
+
+	if (!fl)
+		return git_odb__hashfd(out, fd, size, type);
+
+	/* size of data is used in header, so we have to read the whole file
+	 * into memory to apply filters before beginning to calculate the hash
+	 */
+
+	if (!(error = git_futils_readbuffer_fd(&raw, fd, size))) {
+		git_buf post = GIT_BUF_INIT;
+
+		error = git_filter_list_apply_to_data(&post, fl, &raw);
+
+		git_buf_free(&raw);
+
+		if (!error)
+			error = git_odb_hash(out, post.ptr, post.size, type);
+
+		git_buf_free(&post);
+	}
+
+	return error;
+}
+
+int git_odb__hashlink(git_oid *out, const char *path)
+{
+	struct stat st;
+	int size;
+	int result;
+
+	if (git_path_lstat(path, &st) < 0)
+		return -1;
+
+	if (!git__is_int(st.st_size) || (int)st.st_size < 0) {
+		giterr_set(GITERR_FILESYSTEM, "file size overflow for 32-bit systems");
+		return -1;
+	}
+
+	size = (int)st.st_size;
+
+	if (S_ISLNK(st.st_mode)) {
+		char *link_data;
+		int read_len;
+		size_t alloc_size;
+
+		GITERR_CHECK_ALLOC_ADD(&alloc_size, size, 1);
+		link_data = git__malloc(alloc_size);
+		GITERR_CHECK_ALLOC(link_data);
+
+		read_len = p_readlink(path, link_data, size);
+		link_data[size] = '\0';
+		if (read_len != size) {
+			giterr_set(GITERR_OS, "failed to read symlink data for '%s'", path);
+			git__free(link_data);
+			return -1;
+		}
+
+		result = git_odb_hash(out, link_data, size, GIT_OBJ_BLOB);
+		git__free(link_data);
+	} else {
+		int fd = git_futils_open_ro(path);
+		if (fd < 0)
+			return -1;
+		result = git_odb__hashfd(out, fd, size, GIT_OBJ_BLOB);
+		p_close(fd);
+	}
+
+	return result;
+}
+
+int git_odb_hashfile(git_oid *out, const char *path, git_otype type)
+{
+	git_off_t size;
+	int result, fd = git_futils_open_ro(path);
+	if (fd < 0)
+		return fd;
+
+	if ((size = git_futils_filesize(fd)) < 0 || !git__is_sizet(size)) {
+		giterr_set(GITERR_OS, "file size overflow for 32-bit systems");
+		p_close(fd);
+		return -1;
+	}
+
+	result = git_odb__hashfd(out, fd, (size_t)size, type);
+	p_close(fd);
+	return result;
+}
+
+int git_odb_hash(git_oid *id, const void *data, size_t len, git_otype type)
+{
+	git_rawobj raw;
+
+	assert(id);
+
+	raw.data = (void *)data;
+	raw.len = len;
+	raw.type = type;
+
+	return git_odb__hashobj(id, &raw);
+}
+
+/**
+ * FAKE WSTREAM
+ */
+
+typedef struct {
+	git_odb_stream stream;
+	char *buffer;
+	size_t size, written;
+	git_otype type;
+} fake_wstream;
+
+static int fake_wstream__fwrite(git_odb_stream *_stream, const git_oid *oid)
+{
+	fake_wstream *stream = (fake_wstream *)_stream;
+	return _stream->backend->write(_stream->backend, oid, stream->buffer, stream->size, stream->type);
+}
+
+static int fake_wstream__write(git_odb_stream *_stream, const char *data, size_t len)
+{
+	fake_wstream *stream = (fake_wstream *)_stream;
+
+	assert(stream->written + len <= stream->size);
+
+	memcpy(stream->buffer + stream->written, data, len);
+	stream->written += len;
+	return 0;
+}
+
+static void fake_wstream__free(git_odb_stream *_stream)
+{
+	fake_wstream *stream = (fake_wstream *)_stream;
+
+	git__free(stream->buffer);
+	git__free(stream);
+}
+
+static int init_fake_wstream(git_odb_stream **stream_p, git_odb_backend *backend, git_off_t size, git_otype type)
+{
+	fake_wstream *stream;
+
+	if (!git__is_ssizet(size)) {
+		giterr_set(GITERR_ODB, "object size too large to keep in memory");
+		return -1;
+	}
+
+	stream = git__calloc(1, sizeof(fake_wstream));
+	GITERR_CHECK_ALLOC(stream);
+
+	stream->size = size;
+	stream->type = type;
+	stream->buffer = git__malloc(size);
+	if (stream->buffer == NULL) {
+		git__free(stream);
+		return -1;
+	}
+
+	stream->stream.backend = backend;
+	stream->stream.read = NULL; /* read only */
+	stream->stream.write = &fake_wstream__write;
+	stream->stream.finalize_write = &fake_wstream__fwrite;
+	stream->stream.free = &fake_wstream__free;
+	stream->stream.mode = GIT_STREAM_WRONLY;
+
+	*stream_p = (git_odb_stream *)stream;
+	return 0;
+}
+
+/***********************************************************
+ *
+ * OBJECT DATABASE PUBLIC API
+ *
+ * Public calls for the ODB functionality
+ *
+ ***********************************************************/
+
+static int backend_sort_cmp(const void *a, const void *b)
+{
+	const backend_internal *backend_a = (const backend_internal *)(a);
+	const backend_internal *backend_b = (const backend_internal *)(b);
+
+	if (backend_b->priority == backend_a->priority) {
+		if (backend_a->is_alternate)
+			return -1;
+		if (backend_b->is_alternate)
+			return 1;
+		return 0;
+	}
+	return (backend_b->priority - backend_a->priority);
+}
+
+int git_odb_new(git_odb **out)
+{
+	git_odb *db = git__calloc(1, sizeof(*db));
+	GITERR_CHECK_ALLOC(db);
+
+	if (git_cache_init(&db->own_cache) < 0 ||
+		git_vector_init(&db->backends, 4, backend_sort_cmp) < 0) {
+		git__free(db);
+		return -1;
+	}
+
+	*out = db;
+	GIT_REFCOUNT_INC(db);
+	return 0;
+}
+
+static int add_backend_internal(
+	git_odb *odb, git_odb_backend *backend,
+	int priority, bool is_alternate, ino_t disk_inode)
+{
+	backend_internal *internal;
+
+	assert(odb && backend);
+
+	GITERR_CHECK_VERSION(backend, GIT_ODB_BACKEND_VERSION, "git_odb_backend");
+
+	/* Check if the backend is already owned by another ODB */
+	assert(!backend->odb || backend->odb == odb);
+
+	internal = git__malloc(sizeof(backend_internal));
+	GITERR_CHECK_ALLOC(internal);
+
+	internal->backend = backend;
+	internal->priority = priority;
+	internal->is_alternate = is_alternate;
+	internal->disk_inode = disk_inode;
+
+	if (git_vector_insert(&odb->backends, internal) < 0) {
+		git__free(internal);
+		return -1;
+	}
+
+	git_vector_sort(&odb->backends);
+	internal->backend->odb = odb;
+	return 0;
+}
+
+int git_odb_add_backend(git_odb *odb, git_odb_backend *backend, int priority)
+{
+	return add_backend_internal(odb, backend, priority, false, 0);
+}
+
+int git_odb_add_alternate(git_odb *odb, git_odb_backend *backend, int priority)
+{
+	return add_backend_internal(odb, backend, priority, true, 0);
+}
+
+size_t git_odb_num_backends(git_odb *odb)
+{
+	assert(odb);
+	return odb->backends.length;
+}
+
+static int git_odb__error_unsupported_in_backend(const char *action)
+{
+	giterr_set(GITERR_ODB,
+		"cannot %s - unsupported in the loaded odb backends", action);
+	return -1;
+}
+
+
+int git_odb_get_backend(git_odb_backend **out, git_odb *odb, size_t pos)
+{
+	backend_internal *internal;
+
+	assert(out && odb);
+	internal = git_vector_get(&odb->backends, pos);
+
+	if (internal && internal->backend) {
+		*out = internal->backend;
+		return 0;
+	}
+
+	giterr_set(GITERR_ODB, "no ODB backend loaded at index %" PRIuZ, pos);
+	return GIT_ENOTFOUND;
+}
+
+int git_odb__add_default_backends(
+	git_odb *db, const char *objects_dir,
+	bool as_alternates, int alternate_depth)
+{
+	size_t i;
+	struct stat st;
+	ino_t inode;
+	git_odb_backend *loose, *packed;
+
+	/* TODO: inodes are not really relevant on Win32, so we need to find
+	 * a cross-platform workaround for this */
+#ifdef GIT_WIN32
+	GIT_UNUSED(i);
+	GIT_UNUSED(st);
+
+	inode = 0;
+#else
+	if (p_stat(objects_dir, &st) < 0) {
+		if (as_alternates)
+			return 0;
+
+		giterr_set(GITERR_ODB, "failed to load object database in '%s'", objects_dir);
+		return -1;
+	}
+
+	inode = st.st_ino;
+
+	for (i = 0; i < db->backends.length; ++i) {
+		backend_internal *backend = git_vector_get(&db->backends, i);
+		if (backend->disk_inode == inode)
+			return 0;
+	}
+#endif
+
+	/* add the loose object backend */
+	if (git_odb_backend_loose(&loose, objects_dir, -1, db->do_fsync, 0, 0) < 0 ||
+		add_backend_internal(db, loose, GIT_LOOSE_PRIORITY, as_alternates, inode) < 0)
+		return -1;
+
+	/* add the packed file backend */
+	if (git_odb_backend_pack(&packed, objects_dir) < 0 ||
+		add_backend_internal(db, packed, GIT_PACKED_PRIORITY, as_alternates, inode) < 0)
+		return -1;
+
+	return load_alternates(db, objects_dir, alternate_depth);
+}
+
+static int load_alternates(git_odb *odb, const char *objects_dir, int alternate_depth)
+{
+	git_buf alternates_path = GIT_BUF_INIT;
+	git_buf alternates_buf = GIT_BUF_INIT;
+	char *buffer;
+	const char *alternate;
+	int result = 0;
+
+	/* Git reports an error, we just ignore anything deeper */
+	if (alternate_depth > GIT_ALTERNATES_MAX_DEPTH)
+		return 0;
+
+	if (git_buf_joinpath(&alternates_path, objects_dir, GIT_ALTERNATES_FILE) < 0)
+		return -1;
+
+	if (git_path_exists(alternates_path.ptr) == false) {
+		git_buf_free(&alternates_path);
+		return 0;
+	}
+
+	if (git_futils_readbuffer(&alternates_buf, alternates_path.ptr) < 0) {
+		git_buf_free(&alternates_path);
+		return -1;
+	}
+
+	buffer = (char *)alternates_buf.ptr;
+
+	/* add each alternate as a new backend; one alternate per line */
+	while ((alternate = git__strtok(&buffer, "\r\n")) != NULL) {
+		if (*alternate == '\0' || *alternate == '#')
+			continue;
+
+		/*
+		 * Relative path: build based on the current `objects`
+		 * folder. However, relative paths are only allowed in
+		 * the current repository.
+		 */
+		if (*alternate == '.' && !alternate_depth) {
+			if ((result = git_buf_joinpath(&alternates_path, objects_dir, alternate)) < 0)
+				break;
+			alternate = git_buf_cstr(&alternates_path);
+		}
+
+		if ((result = git_odb__add_default_backends(odb, alternate, true, alternate_depth + 1)) < 0)
+			break;
+	}
+
+	git_buf_free(&alternates_path);
+	git_buf_free(&alternates_buf);
+
+	return result;
+}
+
+int git_odb_add_disk_alternate(git_odb *odb, const char *path)
+{
+	return git_odb__add_default_backends(odb, path, true, 0);
+}
+
+int git_odb_open(git_odb **out, const char *objects_dir)
+{
+	git_odb *db;
+
+	assert(out && objects_dir);
+
+	*out = NULL;
+
+	if (git_odb_new(&db) < 0)
+		return -1;
+
+	if (git_odb__add_default_backends(db, objects_dir, 0, 0) < 0) {
+		git_odb_free(db);
+		return -1;
+	}
+
+	*out = db;
+	return 0;
+}
+
+int git_odb__set_caps(git_odb *odb, int caps)
+{
+	if (caps == GIT_ODB_CAP_FROM_OWNER) {
+		git_repository *repo = odb->rc.owner;
+		int val;
+
+		if (!repo) {
+			giterr_set(GITERR_ODB, "cannot access repository to set odb caps");
+			return -1;
+		}
+
+		if (!git_repository__cvar(&val, repo, GIT_CVAR_FSYNCOBJECTFILES))
+			odb->do_fsync = !!val;
+	}
+
+	return 0;
+}
+
+static void odb_free(git_odb *db)
+{
+	size_t i;
+
+	for (i = 0; i < db->backends.length; ++i) {
+		backend_internal *internal = git_vector_get(&db->backends, i);
+		git_odb_backend *backend = internal->backend;
+
+		backend->free(backend);
+
+		git__free(internal);
+	}
+
+	git_vector_free(&db->backends);
+	git_cache_free(&db->own_cache);
+
+	git__memzero(db, sizeof(*db));
+	git__free(db);
+}
+
+void git_odb_free(git_odb *db)
+{
+	if (db == NULL)
+		return;
+
+	GIT_REFCOUNT_DEC(db, odb_free);
+}
+
+static int odb_exists_1(
+	git_odb *db,
+	const git_oid *id,
+	bool only_refreshed)
+{
+	size_t i;
+	bool found = false;
+
+	for (i = 0; i < db->backends.length && !found; ++i) {
+		backend_internal *internal = git_vector_get(&db->backends, i);
+		git_odb_backend *b = internal->backend;
+
+		if (only_refreshed && !b->refresh)
+			continue;
+
+		if (b->exists != NULL)
+			found = (bool)b->exists(b, id);
+	}
+
+	return (int)found;
+}
+
+static int odb_freshen_1(
+	git_odb *db,
+	const git_oid *id,
+	bool only_refreshed)
+{
+	size_t i;
+	bool found = false;
+
+	for (i = 0; i < db->backends.length && !found; ++i) {
+		backend_internal *internal = git_vector_get(&db->backends, i);
+		git_odb_backend *b = internal->backend;
+
+		if (only_refreshed && !b->refresh)
+			continue;
+
+		if (b->freshen != NULL)
+			found = !b->freshen(b, id);
+		else if (b->exists != NULL)
+			found = b->exists(b, id);
+	}
+
+	return (int)found;
+}
+
+int git_odb__freshen(git_odb *db, const git_oid *id)
+{
+	assert(db && id);
+
+	if (odb_freshen_1(db, id, false))
+		return 1;
+
+	if (!git_odb_refresh(db))
+		return odb_freshen_1(db, id, true);
+
+	/* Failed to refresh, hence not found */
+	return 0;
+}
+
+int git_odb_exists(git_odb *db, const git_oid *id)
+{
+	git_odb_object *object;
+
+	assert(db && id);
+
+	if (git_oid_iszero(id))
+		return 0;
+
+	if ((object = git_cache_get_raw(odb_cache(db), id)) != NULL) {
+		git_odb_object_free(object);
+		return 1;
+	}
+
+	if (odb_exists_1(db, id, false))
+		return 1;
+
+	if (!git_odb_refresh(db))
+		return odb_exists_1(db, id, true);
+
+	/* Failed to refresh, hence not found */
+	return 0;
+}
+
+static int odb_exists_prefix_1(git_oid *out, git_odb *db,
+	const git_oid *key, size_t len, bool only_refreshed)
+{
+	size_t i;
+	int error = GIT_ENOTFOUND, num_found = 0;
+	git_oid last_found = {{0}}, found;
+
+	for (i = 0; i < db->backends.length; ++i) {
+		backend_internal *internal = git_vector_get(&db->backends, i);
+		git_odb_backend *b = internal->backend;
+
+		if (only_refreshed && !b->refresh)
+			continue;
+
+		if (!b->exists_prefix)
+			continue;
+
+		error = b->exists_prefix(&found, b, key, len);
+		if (error == GIT_ENOTFOUND || error == GIT_PASSTHROUGH)
+			continue;
+		if (error)
+			return error;
+
+		/* make sure found item doesn't introduce ambiguity */
+		if (num_found) {
+			if (git_oid__cmp(&last_found, &found))
+				return git_odb__error_ambiguous("multiple matches for prefix");
+		} else {
+			git_oid_cpy(&last_found, &found);
+			num_found++;
+		}
+	}
+
+	if (!num_found)
+		return GIT_ENOTFOUND;
+
+	if (out)
+		git_oid_cpy(out, &last_found);
+
+	return 0;
+}
+
+int git_odb_exists_prefix(
+	git_oid *out, git_odb *db, const git_oid *short_id, size_t len)
+{
+	int error;
+	git_oid key = {{0}};
+
+	assert(db && short_id);
+
+	if (len < GIT_OID_MINPREFIXLEN)
+		return git_odb__error_ambiguous("prefix length too short");
+
+	if (len >= GIT_OID_HEXSZ) {
+		if (git_odb_exists(db, short_id)) {
+			if (out)
+				git_oid_cpy(out, short_id);
+			return 0;
+		} else {
+			return git_odb__error_notfound(
+				"no match for id prefix", short_id, len);
+		}
+	}
+
+	git_oid__cpy_prefix(&key, short_id, len);
+
+	error = odb_exists_prefix_1(out, db, &key, len, false);
+
+	if (error == GIT_ENOTFOUND && !git_odb_refresh(db))
+		error = odb_exists_prefix_1(out, db, &key, len, true);
+
+	if (error == GIT_ENOTFOUND)
+		return git_odb__error_notfound("no match for id prefix", &key, len);
+
+	return error;
+}
+
+int git_odb_expand_ids(
+	git_odb *db,
+	git_odb_expand_id *ids,
+	size_t count)
+{
+	size_t i;
+
+	assert(db && ids);
+
+	for (i = 0; i < count; i++) {
+		git_odb_expand_id *query = &ids[i];
+		int error = GIT_EAMBIGUOUS;
+
+		if (!query->type)
+			query->type = GIT_OBJ_ANY;
+
+		/* if we have a short OID, expand it first */
+		if (query->length >= GIT_OID_MINPREFIXLEN && query->length < GIT_OID_HEXSZ) {
+			git_oid actual_id;
+
+			error = odb_exists_prefix_1(&actual_id, db, &query->id, query->length, false);
+			if (!error) {
+				git_oid_cpy(&query->id, &actual_id);
+				query->length = GIT_OID_HEXSZ;
+			}
+		}
+
+		/*
+		 * now we ought to have a 40-char OID, either because we've expanded it
+		 * or because the user passed a full OID. Ensure its type is right.
+		 */
+		if (query->length >= GIT_OID_HEXSZ) {
+			git_otype actual_type;
+
+			error = odb_otype_fast(&actual_type, db, &query->id);
+			if (!error) {
+				if (query->type != GIT_OBJ_ANY && query->type != actual_type)
+					error = GIT_ENOTFOUND;
+				else
+					query->type = actual_type;
+			}
+		}
+
+		switch (error) {
+		/* no errors, so we've successfully expanded the OID */
+		case 0:
+			continue;
+
+		/* the object is missing or ambiguous */
+		case GIT_ENOTFOUND:
+		case GIT_EAMBIGUOUS:
+			memset(&query->id, 0, sizeof(git_oid));
+			query->length = 0;
+			query->type = 0;
+			break;
+
+		/* something went very wrong with the ODB; bail hard */
+		default:
+			return error;
+		}
+	}
+
+	giterr_clear();
+	return 0;
+}
+
+int git_odb_read_header(size_t *len_p, git_otype *type_p, git_odb *db, const git_oid *id)
+{
+	int error;
+	git_odb_object *object;
+
+	error = git_odb__read_header_or_object(&object, len_p, type_p, db, id);
+
+	if (object)
+		git_odb_object_free(object);
+
+	return error;
+}
+
+static int odb_read_header_1(
+	size_t *len_p, git_otype *type_p, git_odb *db,
+	const git_oid *id, bool only_refreshed)
+{
+	size_t i;
+	git_otype ht;
+	bool passthrough = false;
+	int error;
+
+	if (!only_refreshed && (ht = odb_hardcoded_type(id)) != GIT_OBJ_BAD) {
+		*type_p = ht;
+		*len_p = 0;
+		return 0;
+	}
+
+	for (i = 0; i < db->backends.length; ++i) {
+		backend_internal *internal = git_vector_get(&db->backends, i);
+		git_odb_backend *b = internal->backend;
+
+		if (only_refreshed && !b->refresh)
+			continue;
+
+		if (!b->read_header) {
+			passthrough = true;
+			continue;
+		}
+
+		error = b->read_header(len_p, type_p, b, id);
+
+		switch (error) {
+		case GIT_PASSTHROUGH:
+			passthrough = true;
+			break;
+		case GIT_ENOTFOUND:
+			break;
+		default:
+			return error;
+		}
+	}
+
+	return passthrough ? GIT_PASSTHROUGH : GIT_ENOTFOUND;
+}
+
+int git_odb__read_header_or_object(
+	git_odb_object **out, size_t *len_p, git_otype *type_p,
+	git_odb *db, const git_oid *id)
+{
+	int error = GIT_ENOTFOUND;
+	git_odb_object *object;
+
+	assert(db && id && out && len_p && type_p);
+
+	*out = NULL;
+
+	if (git_oid_iszero(id))
+		return error_null_oid(GIT_ENOTFOUND, "cannot read object");
+
+	if ((object = git_cache_get_raw(odb_cache(db), id)) != NULL) {
+		*len_p = object->cached.size;
+		*type_p = object->cached.type;
+		*out = object;
+		return 0;
+	}
+
+	error = odb_read_header_1(len_p, type_p, db, id, false);
+
+	if (error == GIT_ENOTFOUND && !git_odb_refresh(db))
+		error = odb_read_header_1(len_p, type_p, db, id, true);
+
+	if (error == GIT_ENOTFOUND)
+		return git_odb__error_notfound("cannot read header for", id, GIT_OID_HEXSZ);
+
+	/* we found the header; return early */
+	if (!error)
+		return 0;
+
+	if (error == GIT_PASSTHROUGH) {
+		/*
+		 * no backend has header-reading functionality
+		 * so try using `git_odb_read` instead
+		 */
+		error = git_odb_read(&object, db, id);
+		if (!error) {
+			*len_p = object->cached.size;
+			*type_p = object->cached.type;
+			*out = object;
+		}
+	}
+
+	return error;
+}
+
+static int odb_read_1(git_odb_object **out, git_odb *db, const git_oid *id,
+		bool only_refreshed)
+{
+	size_t i;
+	git_rawobj raw;
+	git_odb_object *object;
+	git_oid hashed;
+	bool found = false;
+	int error = 0;
+
+	if (!only_refreshed) {
+		if ((error = odb_read_hardcoded(&found, &raw, id)) < 0)
+			return error;
+	}
+
+	for (i = 0; i < db->backends.length && !found; ++i) {
+		backend_internal *internal = git_vector_get(&db->backends, i);
+		git_odb_backend *b = internal->backend;
+
+		if (only_refreshed && !b->refresh)
+			continue;
+
+		if (b->read != NULL) {
+			error = b->read(&raw.data, &raw.len, &raw.type, b, id);
+			if (error == GIT_PASSTHROUGH || error == GIT_ENOTFOUND)
+				continue;
+
+			if (error < 0)
+				return error;
+
+			found = true;
+		}
+	}
+
+	if (!found)
+		return GIT_ENOTFOUND;
+
+	if (git_odb__strict_hash_verification) {
+		if ((error = git_odb_hash(&hashed, raw.data, raw.len, raw.type)) < 0)
+			goto out;
+
+		if (!git_oid_equal(id, &hashed)) {
+			error = git_odb__error_mismatch(id, &hashed);
+			goto out;
+		}
+	}
+
+	giterr_clear();
+	if ((object = odb_object__alloc(id, &raw)) == NULL) {
+		error = -1;
+		goto out;
+	}
+
+	*out = git_cache_store_raw(odb_cache(db), object);
+
+out:
+	if (error)
+		git__free(raw.data);
+	return error;
+}
+
+int git_odb_read(git_odb_object **out, git_odb *db, const git_oid *id)
+{
+	int error;
+
+	assert(out && db && id);
+
+	if (git_oid_iszero(id))
+		return error_null_oid(GIT_ENOTFOUND, "cannot read object");
+
+	*out = git_cache_get_raw(odb_cache(db), id);
+	if (*out != NULL)
+		return 0;
+
+	error = odb_read_1(out, db, id, false);
+
+	if (error == GIT_ENOTFOUND && !git_odb_refresh(db))
+		error = odb_read_1(out, db, id, true);
+
+	if (error == GIT_ENOTFOUND)
+		return git_odb__error_notfound("no match for id", id, GIT_OID_HEXSZ);
+
+	return error;
+}
+
+static int odb_otype_fast(git_otype *type_p, git_odb *db, const git_oid *id)
+{
+	git_odb_object *object;
+	size_t _unused;
+	int error;
+
+	if (git_oid_iszero(id))
+		return error_null_oid(GIT_ENOTFOUND, "cannot get object type");
+
+	if ((object = git_cache_get_raw(odb_cache(db), id)) != NULL) {
+		*type_p = object->cached.type;
+		return 0;
+	}
+
+	error = odb_read_header_1(&_unused, type_p, db, id, false);
+
+	if (error == GIT_PASSTHROUGH) {
+		error = odb_read_1(&object, db, id, false);
+		if (!error)
+			*type_p = object->cached.type;
+		git_odb_object_free(object);
+	}
+
+	return error;
+}
+
+static int read_prefix_1(git_odb_object **out, git_odb *db,
+		const git_oid *key, size_t len, bool only_refreshed)
+{
+	size_t i;
+	int error = 0;
+	git_oid found_full_oid = {{0}};
+	git_rawobj raw = {0};
+	void *data = NULL;
+	bool found = false;
+	git_odb_object *object;
+
+	for (i = 0; i < db->backends.length; ++i) {
+		backend_internal *internal = git_vector_get(&db->backends, i);
+		git_odb_backend *b = internal->backend;
+
+		if (only_refreshed && !b->refresh)
+			continue;
+
+		if (b->read_prefix != NULL) {
+			git_oid full_oid;
+			error = b->read_prefix(&full_oid, &raw.data, &raw.len, &raw.type, b, key, len);
+
+			if (error == GIT_ENOTFOUND || error == GIT_PASSTHROUGH) {
+				error = 0;
+				continue;
+			}
+
+			if (error)
+				goto out;
+
+			git__free(data);
+			data = raw.data;
+
+			if (found && git_oid__cmp(&full_oid, &found_full_oid)) {
+				git_buf buf = GIT_BUF_INIT;
+
+				git_buf_printf(&buf, "multiple matches for prefix: %s",
+					git_oid_tostr_s(&full_oid));
+				git_buf_printf(&buf, " %s",
+					git_oid_tostr_s(&found_full_oid));
+
+				error = git_odb__error_ambiguous(buf.ptr);
+				git_buf_free(&buf);
+				goto out;
+			}
+
+			found_full_oid = full_oid;
+			found = true;
+		}
+	}
+
+	if (!found)
+		return GIT_ENOTFOUND;
+
+	if (git_odb__strict_hash_verification) {
+		git_oid hash;
+
+		if ((error = git_odb_hash(&hash, raw.data, raw.len, raw.type)) < 0)
+			goto out;
+
+		if (!git_oid_equal(&found_full_oid, &hash)) {
+			error = git_odb__error_mismatch(&found_full_oid, &hash);
+			goto out;
+		}
+	}
+
+	if ((object = odb_object__alloc(&found_full_oid, &raw)) == NULL) {
+		error = -1;
+		goto out;
+	}
+
+	*out = git_cache_store_raw(odb_cache(db), object);
+
+out:
+	if (error)
+		git__free(raw.data);
+
+	return error;
+}
+
+int git_odb_read_prefix(
+	git_odb_object **out, git_odb *db, const git_oid *short_id, size_t len)
+{
+	git_oid key = {{0}};
+	int error;
+
+	assert(out && db);
+
+	if (len < GIT_OID_MINPREFIXLEN)
+		return git_odb__error_ambiguous("prefix length too short");
+
+	if (len > GIT_OID_HEXSZ)
+		len = GIT_OID_HEXSZ;
+
+	if (len == GIT_OID_HEXSZ) {
+		*out = git_cache_get_raw(odb_cache(db), short_id);
+		if (*out != NULL)
+			return 0;
+	}
+
+	git_oid__cpy_prefix(&key, short_id, len);
+
+	error = read_prefix_1(out, db, &key, len, false);
+
+	if (error == GIT_ENOTFOUND && !git_odb_refresh(db))
+		error = read_prefix_1(out, db, &key, len, true);
+
+	if (error == GIT_ENOTFOUND)
+		return git_odb__error_notfound("no match for prefix", &key, len);
+
+	return error;
+}
+
+int git_odb_foreach(git_odb *db, git_odb_foreach_cb cb, void *payload)
+{
+	unsigned int i;
+	backend_internal *internal;
+
+	git_vector_foreach(&db->backends, i, internal) {
+		git_odb_backend *b = internal->backend;
+		int error = b->foreach(b, cb, payload);
+		if (error < 0)
+			return error;
+	}
+
+	return 0;
+}
+
+int git_odb_write(
+	git_oid *oid, git_odb *db, const void *data, size_t len, git_otype type)
+{
+	size_t i;
+	int error = GIT_ERROR;
+	git_odb_stream *stream;
+
+	assert(oid && db);
+
+	git_odb_hash(oid, data, len, type);
+
+	if (git_oid_iszero(oid))
+		return error_null_oid(GIT_EINVALID, "cannot write object");
+
+	if (git_odb__freshen(db, oid))
+		return 0;
+
+	for (i = 0; i < db->backends.length && error < 0; ++i) {
+		backend_internal *internal = git_vector_get(&db->backends, i);
+		git_odb_backend *b = internal->backend;
+
+		/* we don't write in alternates! */
+		if (internal->is_alternate)
+			continue;
+
+		if (b->write != NULL)
+			error = b->write(b, oid, data, len, type);
+	}
+
+	if (!error || error == GIT_PASSTHROUGH)
+		return 0;
+
+	/* if no backends were able to write the object directly, we try a
+	 * streaming write to the backends; just write the whole object into the
+	 * stream in one push
+	 */
+	if ((error = git_odb_open_wstream(&stream, db, len, type)) != 0)
+		return error;
+
+	stream->write(stream, data, len);
+	error = stream->finalize_write(stream, oid);
+	git_odb_stream_free(stream);
+
+	return error;
+}
+
+static int hash_header(git_hash_ctx *ctx, git_off_t size, git_otype type)
+{
+	char header[64];
+	size_t hdrlen;
+	int error;
+
+	 if ((error = git_odb__format_object_header(&hdrlen,
+		header, sizeof(header), size, type)) < 0)
+		return error;
+
+	return git_hash_update(ctx, header, hdrlen);
+}
+
+int git_odb_open_wstream(
+	git_odb_stream **stream, git_odb *db, git_off_t size, git_otype type)
+{
+	size_t i, writes = 0;
+	int error = GIT_ERROR;
+	git_hash_ctx *ctx = NULL;
+
+	assert(stream && db);
+
+	for (i = 0; i < db->backends.length && error < 0; ++i) {
+		backend_internal *internal = git_vector_get(&db->backends, i);
+		git_odb_backend *b = internal->backend;
+
+		/* we don't write in alternates! */
+		if (internal->is_alternate)
+			continue;
+
+		if (b->writestream != NULL) {
+			++writes;
+			error = b->writestream(stream, b, size, type);
+		} else if (b->write != NULL) {
+			++writes;
+			error = init_fake_wstream(stream, b, size, type);
+		}
+	}
+
+	if (error < 0) {
+		if (error == GIT_PASSTHROUGH)
+			error = 0;
+		else if (!writes)
+			error = git_odb__error_unsupported_in_backend("write object");
+
+		goto done;
+	}
+
+	ctx = git__malloc(sizeof(git_hash_ctx));
+	GITERR_CHECK_ALLOC(ctx);
+
+	if ((error = git_hash_ctx_init(ctx)) < 0 ||
+		(error = hash_header(ctx, size, type)) < 0)
+		goto done;
+
+	(*stream)->hash_ctx = ctx;
+	(*stream)->declared_size = size;
+	(*stream)->received_bytes = 0;
+
+done:
+	if (error)
+		git__free(ctx);
+	return error;
+}
+
+static int git_odb_stream__invalid_length(
+	const git_odb_stream *stream,
+	const char *action)
+{
+	giterr_set(GITERR_ODB,
+		"cannot %s - "
+		"Invalid length. %"PRIdZ" was expected. The "
+		"total size of the received chunks amounts to %"PRIdZ".",
+		action, stream->declared_size, stream->received_bytes);
+
+	return -1;
+}
+
+int git_odb_stream_write(git_odb_stream *stream, const char *buffer, size_t len)
+{
+	git_hash_update(stream->hash_ctx, buffer, len);
+
+	stream->received_bytes += len;
+
+	if (stream->received_bytes > stream->declared_size)
+		return git_odb_stream__invalid_length(stream,
+			"stream_write()");
+
+	return stream->write(stream, buffer, len);
+}
+
+int git_odb_stream_finalize_write(git_oid *out, git_odb_stream *stream)
+{
+	if (stream->received_bytes != stream->declared_size)
+		return git_odb_stream__invalid_length(stream,
+			"stream_finalize_write()");
+
+	git_hash_final(out, stream->hash_ctx);
+
+	if (git_odb__freshen(stream->backend->odb, out))
+		return 0;
+
+	return stream->finalize_write(stream, out);
+}
+
+int git_odb_stream_read(git_odb_stream *stream, char *buffer, size_t len)
+{
+	return stream->read(stream, buffer, len);
+}
+
+void git_odb_stream_free(git_odb_stream *stream)
+{
+	if (stream == NULL)
+		return;
+
+	git_hash_ctx_cleanup(stream->hash_ctx);
+	git__free(stream->hash_ctx);
+	stream->free(stream);
+}
+
+int git_odb_open_rstream(
+	git_odb_stream **stream,
+	size_t *len,
+	git_otype *type,
+	git_odb *db,
+	const git_oid *oid)
+{
+	size_t i, reads = 0;
+	int error = GIT_ERROR;
+
+	assert(stream && db);
+
+	for (i = 0; i < db->backends.length && error < 0; ++i) {
+		backend_internal *internal = git_vector_get(&db->backends, i);
+		git_odb_backend *b = internal->backend;
+
+		if (b->readstream != NULL) {
+			++reads;
+			error = b->readstream(stream, len, type, b, oid);
+		}
+	}
+
+	if (error == GIT_PASSTHROUGH)
+		error = 0;
+	if (error < 0 && !reads)
+		error = git_odb__error_unsupported_in_backend("read object streamed");
+
+	return error;
+}
+
+int git_odb_write_pack(struct git_odb_writepack **out, git_odb *db, git_transfer_progress_cb progress_cb, void *progress_payload)
+{
+	size_t i, writes = 0;
+	int error = GIT_ERROR;
+
+	assert(out && db);
+
+	for (i = 0; i < db->backends.length && error < 0; ++i) {
+		backend_internal *internal = git_vector_get(&db->backends, i);
+		git_odb_backend *b = internal->backend;
+
+		/* we don't write in alternates! */
+		if (internal->is_alternate)
+			continue;
+
+		if (b->writepack != NULL) {
+			++writes;
+			error = b->writepack(out, b, db, progress_cb, progress_payload);
+		}
+	}
+
+	if (error == GIT_PASSTHROUGH)
+		error = 0;
+	if (error < 0 && !writes)
+		error = git_odb__error_unsupported_in_backend("write pack");
+
+	return error;
+}
+
+void *git_odb_backend_malloc(git_odb_backend *backend, size_t len)
+{
+	GIT_UNUSED(backend);
+	return git__malloc(len);
+}
+
+int git_odb_refresh(struct git_odb *db)
+{
+	size_t i;
+	assert(db);
+
+	for (i = 0; i < db->backends.length; ++i) {
+		backend_internal *internal = git_vector_get(&db->backends, i);
+		git_odb_backend *b = internal->backend;
+
+		if (b->refresh != NULL) {
+			int error = b->refresh(b);
+			if (error < 0)
+				return error;
+		}
+	}
+
+	return 0;
+}
+
+int git_odb__error_mismatch(const git_oid *expected, const git_oid *actual)
+{
+	char expected_oid[GIT_OID_HEXSZ + 1], actual_oid[GIT_OID_HEXSZ + 1];
+
+	git_oid_tostr(expected_oid, sizeof(expected_oid), expected);
+	git_oid_tostr(actual_oid, sizeof(actual_oid), actual);
+
+	giterr_set(GITERR_ODB, "object hash mismatch - expected %s but got %s",
+		expected_oid, actual_oid);
+
+	return GIT_EMISMATCH;
+}
+
+int git_odb__error_notfound(
+	const char *message, const git_oid *oid, size_t oid_len)
+{
+	if (oid != NULL) {
+		char oid_str[GIT_OID_HEXSZ + 1];
+		git_oid_tostr(oid_str, oid_len+1, oid);
+		giterr_set(GITERR_ODB, "object not found - %s (%.*s)",
+			message, (int) oid_len, oid_str);
+	} else
+		giterr_set(GITERR_ODB, "object not found - %s", message);
+
+	return GIT_ENOTFOUND;
+}
+
+static int error_null_oid(int error, const char *message)
+{
+	giterr_set(GITERR_ODB, "odb: %s: null OID cannot exist", message);
+	return error;
+}
+
+int git_odb__error_ambiguous(const char *message)
+{
+	giterr_set(GITERR_ODB, "ambiguous SHA1 prefix - %s", message);
+	return GIT_EAMBIGUOUS;
+}
+
+int git_odb_init_backend(git_odb_backend *backend, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		backend, version, git_odb_backend, GIT_ODB_BACKEND_INIT);
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/odb.h

diff --git a/vendor/libgit2-sys/libgit2/src/odb.h b/vendor/libgit2-sys/libgit2/src/odb.h
new file mode 100644
index 0000000..b354108
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/odb.h
@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_odb_h__
+#define INCLUDE_odb_h__
+
+#include "common.h"
+
+#include "git2/odb.h"
+#include "git2/oid.h"
+#include "git2/types.h"
+
+#include "vector.h"
+#include "cache.h"
+#include "posix.h"
+#include "filter.h"
+
+#define GIT_OBJECTS_DIR "objects/"
+#define GIT_OBJECT_DIR_MODE 0777
+#define GIT_OBJECT_FILE_MODE 0444
+
+extern bool git_odb__strict_hash_verification;
+
+/* DO NOT EXPORT */
+typedef struct {
+	void *data;			/**< Raw, decompressed object data. */
+	size_t len;			/**< Total number of bytes in data. */
+	git_otype type;		/**< Type of this object. */
+} git_rawobj;
+
+/* EXPORT */
+struct git_odb_object {
+	git_cached_obj cached;
+	void *buffer;
+};
+
+/* EXPORT */
+struct git_odb {
+	git_refcount rc;
+	git_vector backends;
+	git_cache own_cache;
+	unsigned int do_fsync :1;
+};
+
+typedef enum {
+	GIT_ODB_CAP_FROM_OWNER = -1,
+} git_odb_cap_t;
+
+/*
+ * Set the capabilities for the object database.
+ */
+int git_odb__set_caps(git_odb *odb, int caps);
+
+/*
+ * Add the default loose and packed backends for a database.
+ */
+int git_odb__add_default_backends(
+	git_odb *db, const char *objects_dir,
+	bool as_alternates, int alternate_depth);
+
+/*
+ * Hash a git_rawobj internally.
+ * The `git_rawobj` is supposed to be previously initialized
+ */
+int git_odb__hashobj(git_oid *id, git_rawobj *obj);
+
+/*
+ * Format the object header such as it would appear in the on-disk object
+ */
+int git_odb__format_object_header(size_t *out_len, char *hdr, size_t hdr_size, git_off_t obj_len, git_otype obj_type);
+/*
+ * Hash an open file descriptor.
+ * This is a performance call when the contents of a fd need to be hashed,
+ * but the fd is already open and we have the size of the contents.
+ *
+ * Saves us some `stat` calls.
+ *
+ * The fd is never closed, not even on error. It must be opened and closed
+ * by the caller
+ */
+int git_odb__hashfd(git_oid *out, git_file fd, size_t size, git_otype type);
+
+/*
+ * Hash an open file descriptor applying an array of filters
+ * Acts just like git_odb__hashfd with the addition of filters...
+ */
+int git_odb__hashfd_filtered(
+	git_oid *out, git_file fd, size_t len, git_otype type, git_filter_list *fl);
+
+/*
+ * Hash a `path`, assuming it could be a POSIX symlink: if the path is a
+ * symlink, then the raw contents of the symlink will be hashed. Otherwise,
+ * this will fallback to `git_odb__hashfd`.
+ *
+ * The hash type for this call is always `GIT_OBJ_BLOB` because symlinks may
+ * only point to blobs.
+ */
+int git_odb__hashlink(git_oid *out, const char *path);
+
+/**
+ * Generate a GIT_EMISMATCH error for the ODB.
+ */
+int git_odb__error_mismatch(
+	const git_oid *expected, const git_oid *actual);
+
+/*
+ * Generate a GIT_ENOTFOUND error for the ODB.
+ */
+int git_odb__error_notfound(
+	const char *message, const git_oid *oid, size_t oid_len);
+
+/*
+ * Generate a GIT_EAMBIGUOUS error for the ODB.
+ */
+int git_odb__error_ambiguous(const char *message);
+
+/*
+ * Attempt to read object header or just return whole object if it could
+ * not be read.
+ */
+int git_odb__read_header_or_object(
+	git_odb_object **out, size_t *len_p, git_otype *type_p,
+	git_odb *db, const git_oid *id);
+
+/* freshen an entry in the object database */
+int git_odb__freshen(git_odb *db, const git_oid *id);
+
+/* fully free the object; internal method, DO NOT EXPORT */
+void git_odb_object__free(void *object);
+
+#endif

vendor/libgit2-sys/libgit2/src/odb_loose.c

diff --git a/vendor/libgit2-sys/libgit2/src/odb_loose.c b/vendor/libgit2-sys/libgit2/src/odb_loose.c
new file mode 100644
index 0000000..470421e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/odb_loose.c
@@ -0,0 +1,1161 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include <zlib.h>
+#include "git2/object.h"
+#include "git2/sys/odb_backend.h"
+#include "fileops.h"
+#include "hash.h"
+#include "odb.h"
+#include "delta.h"
+#include "filebuf.h"
+#include "object.h"
+#include "zstream.h"
+
+#include "git2/odb_backend.h"
+#include "git2/types.h"
+
+/* maximum possible header length */
+#define MAX_HEADER_LEN 64
+
+typedef struct { /* object header data */
+	git_otype type; /* object type */
+	size_t	size; /* object size */
+} obj_hdr;
+
+typedef struct {
+	git_odb_stream stream;
+	git_filebuf fbuf;
+} loose_writestream;
+
+typedef struct {
+	git_odb_stream stream;
+	git_map map;
+	char start[MAX_HEADER_LEN];
+	size_t start_len;
+	size_t start_read;
+	git_zstream zstream;
+} loose_readstream;
+
+typedef struct loose_backend {
+	git_odb_backend parent;
+
+	int object_zlib_level; /** loose object zlib compression level. */
+	int fsync_object_files; /** loose object file fsync flag. */
+	mode_t object_file_mode;
+	mode_t object_dir_mode;
+
+	size_t objects_dirlen;
+	char objects_dir[GIT_FLEX_ARRAY];
+} loose_backend;
+
+/* State structure for exploring directories,
+ * in order to locate objects matching a short oid.
+ */
+typedef struct {
+	size_t dir_len;
+	unsigned char short_oid[GIT_OID_HEXSZ]; /* hex formatted oid to match */
+	size_t short_oid_len;
+	int found;				/* number of matching
+						 * objects already found */
+	unsigned char res_oid[GIT_OID_HEXSZ];	/* hex formatted oid of
+						 * the object found */
+} loose_locate_object_state;
+
+
+/***********************************************************
+ *
+ * MISCELLANEOUS HELPER FUNCTIONS
+ *
+ ***********************************************************/
+
+static int object_file_name(
+	git_buf *name, const loose_backend *be, const git_oid *id)
+{
+	size_t alloclen;
+
+	/* expand length for object root + 40 hex sha1 chars + 2 * '/' + '\0' */
+	GITERR_CHECK_ALLOC_ADD(&alloclen, be->objects_dirlen, GIT_OID_HEXSZ);
+	GITERR_CHECK_ALLOC_ADD(&alloclen, alloclen, 3);
+	if (git_buf_grow(name, alloclen) < 0)
+		return -1;
+
+	git_buf_set(name, be->objects_dir, be->objects_dirlen);
+	git_path_to_dir(name);
+
+	/* loose object filename: aa/aaa... (41 bytes) */
+	git_oid_pathfmt(name->ptr + name->size, id);
+	name->size += GIT_OID_HEXSZ + 1;
+	name->ptr[name->size] = '\0';
+
+	return 0;
+}
+
+static int object_mkdir(const git_buf *name, const loose_backend *be)
+{
+	return git_futils_mkdir_relative(
+		name->ptr + be->objects_dirlen, be->objects_dir, be->object_dir_mode,
+		GIT_MKDIR_PATH | GIT_MKDIR_SKIP_LAST | GIT_MKDIR_VERIFY_DIR, NULL);
+}
+
+static int parse_header_packlike(
+	obj_hdr *out, size_t *out_len, const unsigned char *data, size_t len)
+{
+	unsigned long c;
+	size_t shift, size, used = 0;
+
+	if (len == 0)
+		goto on_error;
+
+	c = data[used++];
+	out->type = (c >> 4) & 7;
+
+	size = c & 15;
+	shift = 4;
+	while (c & 0x80) {
+		if (len <= used)
+			goto on_error;
+
+		if (sizeof(size_t) * 8 <= shift)
+			goto on_error;
+
+		c = data[used++];
+		size += (c & 0x7f) << shift;
+		shift += 7;
+	}
+
+	out->size = size;
+
+	if (out_len)
+		*out_len = used;
+
+	return 0;
+
+on_error:
+	giterr_set(GITERR_OBJECT, "failed to parse loose object: invalid header");
+	return -1;
+}
+
+static int parse_header(
+	obj_hdr *out,
+       	size_t *out_len,
+	const unsigned char *_data,
+	size_t data_len)
+{
+	const char *data = (char *)_data;
+	size_t i, typename_len, size_idx, size_len;
+	int64_t size;
+
+	*out_len = 0;
+
+	/* find the object type name */
+	for (i = 0, typename_len = 0; i < data_len; i++, typename_len++) {
+		if (data[i] == ' ')
+			break;
+	}
+
+	if (typename_len == data_len)
+		goto on_error;
+
+	out->type = git_object_stringn2type(data, typename_len);
+
+	size_idx = typename_len + 1;
+	for (i = size_idx, size_len = 0; i < data_len; i++, size_len++) {
+		if (data[i] == '\0')
+			break;
+	}
+
+	if (i == data_len)
+		goto on_error;
+
+	if (git__strntol64(&size, &data[size_idx], size_len, NULL, 10) < 0 ||
+		size < 0)
+		goto on_error;
+
+	if ((uint64_t)size > SIZE_MAX) {
+		giterr_set(GITERR_OBJECT, "object is larger than available memory");
+		return -1;
+	}
+
+	out->size = size;
+
+	if (GIT_ADD_SIZET_OVERFLOW(out_len, i, 1))
+		goto on_error;
+
+	return 0;
+
+on_error:
+	giterr_set(GITERR_OBJECT, "failed to parse loose object: invalid header");
+	return -1;
+}
+
+static int is_zlib_compressed_data(unsigned char *data, size_t data_len)
+{
+	unsigned int w;
+
+	if (data_len < 2)
+		return 0;
+
+	w = ((unsigned int)(data[0]) << 8) + data[1];
+	return (data[0] & 0x8F) == 0x08 && !(w % 31);
+}
+
+/***********************************************************
+ *
+ * ODB OBJECT READING & WRITING
+ *
+ * Backend for the public API; read headers and full objects
+ * from the ODB. Write raw data to the ODB.
+ *
+ ***********************************************************/
+
+
+/*
+ * At one point, there was a loose object format that was intended to
+ * mimic the format used in pack-files. This was to allow easy copying
+ * of loose object data into packs. This format is no longer used, but
+ * we must still read it.
+ */
+static int read_loose_packlike(git_rawobj *out, git_buf *obj)
+{
+	git_buf body = GIT_BUF_INIT;
+	const unsigned char *obj_data;
+	obj_hdr hdr;
+	size_t obj_len, head_len, alloc_size;
+	int error;
+
+	obj_data = (unsigned char *)obj->ptr;
+	obj_len = obj->size;
+
+	/*
+	 * read the object header, which is an (uncompressed)
+	 * binary encoding of the object type and size.
+	 */
+	if ((error = parse_header_packlike(&hdr, &head_len, obj_data, obj_len)) < 0)
+		goto done;
+
+	if (!git_object_typeisloose(hdr.type) || head_len > obj_len) {
+		giterr_set(GITERR_ODB, "failed to inflate loose object");
+		error = -1;
+		goto done;
+	}
+
+	obj_data += head_len;
+	obj_len -= head_len;
+
+	/*
+	 * allocate a buffer and inflate the data into it
+	 */
+	if (GIT_ADD_SIZET_OVERFLOW(&alloc_size, hdr.size, 1) ||
+		git_buf_init(&body, alloc_size) < 0) {
+		error = -1;
+		goto done;
+	}
+
+	if ((error = git_zstream_inflatebuf(&body, obj_data, obj_len)) < 0)
+		goto done;
+
+	out->len = hdr.size;
+	out->type = hdr.type;
+	out->data = git_buf_detach(&body);
+
+done:
+	git_buf_free(&body);
+	return error;
+}
+
+static int read_loose_standard(git_rawobj *out, git_buf *obj)
+{
+	git_zstream zstream = GIT_ZSTREAM_INIT;
+	unsigned char head[MAX_HEADER_LEN], *body = NULL;
+	size_t decompressed, head_len, body_len, alloc_size;
+	obj_hdr hdr;
+	int error;
+
+	if ((error = git_zstream_init(&zstream, GIT_ZSTREAM_INFLATE)) < 0 ||
+		(error = git_zstream_set_input(&zstream, git_buf_cstr(obj), git_buf_len(obj))) < 0)
+		goto done;
+
+	decompressed = sizeof(head);
+
+	/*
+	 * inflate the initial part of the compressed buffer in order to
+	 * parse the header; read the largest header possible, then push the
+	 * remainder into the body buffer.
+	 */
+	if ((error = git_zstream_get_output(head, &decompressed, &zstream)) < 0 ||
+		(error = parse_header(&hdr, &head_len, head, decompressed)) < 0)
+		goto done;
+
+	if (!git_object_typeisloose(hdr.type)) {
+		giterr_set(GITERR_ODB, "failed to inflate disk object");
+		error = -1;
+		goto done;
+	}
+
+	/*
+	 * allocate a buffer and inflate the object data into it
+	 * (including the initial sequence in the head buffer).
+	 */
+	if (GIT_ADD_SIZET_OVERFLOW(&alloc_size, hdr.size, 1) ||
+		(body = git__malloc(alloc_size)) == NULL) {
+		error = -1;
+		goto done;
+	}
+
+	assert(decompressed >= head_len);
+	body_len = decompressed - head_len;
+
+	if (body_len)
+		memcpy(body, head + head_len, body_len);
+
+	decompressed = hdr.size - body_len;
+	if ((error = git_zstream_get_output(body + body_len, &decompressed, &zstream)) < 0)
+		goto done;
+
+	if (!git_zstream_done(&zstream)) {
+		giterr_set(GITERR_ZLIB, "failed to finish zlib inflation: stream aborted prematurely");
+		error = -1;
+		goto done;
+	}
+
+	body[hdr.size] = '\0';
+
+	out->data = body;
+	out->len = hdr.size;
+	out->type = hdr.type;
+
+done:
+	if (error < 0)
+		git__free(body);
+
+	git_zstream_free(&zstream);
+	return error;
+}
+
+static int read_loose(git_rawobj *out, git_buf *loc)
+{
+	int error;
+	git_buf obj = GIT_BUF_INIT;
+
+	assert(out && loc);
+
+	if (git_buf_oom(loc))
+		return -1;
+
+	out->data = NULL;
+	out->len = 0;
+	out->type = GIT_OBJ_BAD;
+
+	if ((error = git_futils_readbuffer(&obj, loc->ptr)) < 0)
+		goto done;
+
+	if (!is_zlib_compressed_data((unsigned char *)obj.ptr, obj.size))
+		error = read_loose_packlike(out, &obj);
+	else
+		error = read_loose_standard(out, &obj);
+
+done:
+	git_buf_free(&obj);
+	return error;
+}
+
+static int read_header_loose_packlike(
+	git_rawobj *out, const unsigned char *data, size_t len)
+{
+	obj_hdr hdr;
+	size_t header_len;
+	int error;
+
+	if ((error = parse_header_packlike(&hdr, &header_len, data, len)) < 0)
+		return error;
+
+	out->len = hdr.size;
+	out->type = hdr.type;
+
+	return error;
+}
+
+static int read_header_loose_standard(
+	git_rawobj *out, const unsigned char *data, size_t len)
+{
+	git_zstream zs = GIT_ZSTREAM_INIT;
+	obj_hdr hdr;
+	unsigned char inflated[MAX_HEADER_LEN];
+	size_t header_len, inflated_len = sizeof(inflated);
+	int error;
+
+	if ((error = git_zstream_init(&zs, GIT_ZSTREAM_INFLATE)) < 0 ||
+		(error = git_zstream_set_input(&zs, data, len)) < 0 ||
+		(error = git_zstream_get_output_chunk(inflated, &inflated_len, &zs)) < 0 ||
+		(error = parse_header(&hdr, &header_len, inflated, inflated_len)) < 0)
+		goto done;
+
+	out->len = hdr.size;
+	out->type = hdr.type;
+
+done:
+	git_zstream_free(&zs);
+	return error;
+}
+
+static int read_header_loose(git_rawobj *out, git_buf *loc)
+{
+	unsigned char obj[1024];
+	int fd, obj_len, error;
+
+	assert(out && loc);
+
+	if (git_buf_oom(loc))
+		return -1;
+
+	out->data = NULL;
+
+	if ((error = fd = git_futils_open_ro(loc->ptr)) < 0 ||
+		(error = obj_len = p_read(fd, obj, sizeof(obj))) < 0)
+		goto done;
+
+	if (!is_zlib_compressed_data(obj, (size_t)obj_len))
+		error = read_header_loose_packlike(out, obj, (size_t)obj_len);
+	else
+		error = read_header_loose_standard(out, obj, (size_t)obj_len);
+
+	if (!error && !git_object_typeisloose(out->type)) {
+		giterr_set(GITERR_ZLIB, "failed to read loose object header");
+		error = -1;
+		goto done;
+	}
+
+done:
+	if (fd >= 0)
+		p_close(fd);
+	return error;
+}
+
+static int locate_object(
+	git_buf *object_location,
+	loose_backend *backend,
+	const git_oid *oid)
+{
+	int error = object_file_name(object_location, backend, oid);
+
+	if (!error && !git_path_exists(object_location->ptr))
+		return GIT_ENOTFOUND;
+
+	return error;
+}
+
+/* Explore an entry of a directory and see if it matches a short oid */
+static int fn_locate_object_short_oid(void *state, git_buf *pathbuf) {
+	loose_locate_object_state *sstate = (loose_locate_object_state *)state;
+
+	if (git_buf_len(pathbuf) - sstate->dir_len != GIT_OID_HEXSZ - 2) {
+		/* Entry cannot be an object. Continue to next entry */
+		return 0;
+	}
+
+	if (git_path_isdir(pathbuf->ptr) == false) {
+		/* We are already in the directory matching the 2 first hex characters,
+		 * compare the first ncmp characters of the oids */
+		if (!memcmp(sstate->short_oid + 2,
+			(unsigned char *)pathbuf->ptr + sstate->dir_len,
+			sstate->short_oid_len - 2)) {
+
+			if (!sstate->found) {
+				sstate->res_oid[0] = sstate->short_oid[0];
+				sstate->res_oid[1] = sstate->short_oid[1];
+				memcpy(sstate->res_oid+2, pathbuf->ptr+sstate->dir_len, GIT_OID_HEXSZ-2);
+			}
+			sstate->found++;
+		}
+	}
+
+	if (sstate->found > 1)
+		return GIT_EAMBIGUOUS;
+
+	return 0;
+}
+
+/* Locate an object matching a given short oid */
+static int locate_object_short_oid(
+	git_buf *object_location,
+	git_oid *res_oid,
+	loose_backend *backend,
+	const git_oid *short_oid,
+	size_t len)
+{
+	char *objects_dir = backend->objects_dir;
+	size_t dir_len = strlen(objects_dir), alloc_len;
+	loose_locate_object_state state;
+	int error;
+
+	/* prealloc memory for OBJ_DIR/xx/xx..38x..xx */
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, dir_len, GIT_OID_HEXSZ);
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, 3);
+	if (git_buf_grow(object_location, alloc_len) < 0)
+		return -1;
+
+	git_buf_set(object_location, objects_dir, dir_len);
+	git_path_to_dir(object_location);
+
+	/* save adjusted position at end of dir so it can be restored later */
+	dir_len = git_buf_len(object_location);
+
+	/* Convert raw oid to hex formatted oid */
+	git_oid_fmt((char *)state.short_oid, short_oid);
+
+	/* Explore OBJ_DIR/xx/ where xx is the beginning of hex formatted short oid */
+	if (git_buf_put(object_location, (char *)state.short_oid, 3) < 0)
+		return -1;
+	object_location->ptr[object_location->size - 1] = '/';
+
+	/* Check that directory exists */
+	if (git_path_isdir(object_location->ptr) == false)
+		return git_odb__error_notfound("no matching loose object for prefix",
+			short_oid, len);
+
+	state.dir_len = git_buf_len(object_location);
+	state.short_oid_len = len;
+	state.found = 0;
+
+	/* Explore directory to find a unique object matching short_oid */
+	error = git_path_direach(
+		object_location, 0, fn_locate_object_short_oid, &state);
+	if (error < 0 && error != GIT_EAMBIGUOUS)
+		return error;
+
+	if (!state.found)
+		return git_odb__error_notfound("no matching loose object for prefix",
+			short_oid, len);
+
+	if (state.found > 1)
+		return git_odb__error_ambiguous("multiple matches in loose objects");
+
+	/* Convert obtained hex formatted oid to raw */
+	error = git_oid_fromstr(res_oid, (char *)state.res_oid);
+	if (error)
+		return error;
+
+	/* Update the location according to the oid obtained */
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, dir_len, GIT_OID_HEXSZ);
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, 2);
+
+	git_buf_truncate(object_location, dir_len);
+	if (git_buf_grow(object_location, alloc_len) < 0)
+		return -1;
+
+	git_oid_pathfmt(object_location->ptr + dir_len, res_oid);
+
+	object_location->size += GIT_OID_HEXSZ + 1;
+	object_location->ptr[object_location->size] = '\0';
+
+	return 0;
+}
+
+
+
+
+
+
+
+
+
+/***********************************************************
+ *
+ * LOOSE BACKEND PUBLIC API
+ *
+ * Implement the git_odb_backend API calls
+ *
+ ***********************************************************/
+
+static int loose_backend__read_header(size_t *len_p, git_otype *type_p, git_odb_backend *backend, const git_oid *oid)
+{
+	git_buf object_path = GIT_BUF_INIT;
+	git_rawobj raw;
+	int error;
+
+	assert(backend && oid);
+
+	raw.len = 0;
+	raw.type = GIT_OBJ_BAD;
+
+	if (locate_object(&object_path, (loose_backend *)backend, oid) < 0) {
+		error = git_odb__error_notfound("no matching loose object",
+			oid, GIT_OID_HEXSZ);
+	} else if ((error = read_header_loose(&raw, &object_path)) == 0) {
+		*len_p = raw.len;
+		*type_p = raw.type;
+	}
+
+	git_buf_free(&object_path);
+
+	return error;
+}
+
+static int loose_backend__read(void **buffer_p, size_t *len_p, git_otype *type_p, git_odb_backend *backend, const git_oid *oid)
+{
+	git_buf object_path = GIT_BUF_INIT;
+	git_rawobj raw;
+	int error = 0;
+
+	assert(backend && oid);
+
+	if (locate_object(&object_path, (loose_backend *)backend, oid) < 0) {
+		error = git_odb__error_notfound("no matching loose object",
+			oid, GIT_OID_HEXSZ);
+	} else if ((error = read_loose(&raw, &object_path)) == 0) {
+		*buffer_p = raw.data;
+		*len_p = raw.len;
+		*type_p = raw.type;
+	}
+
+	git_buf_free(&object_path);
+
+	return error;
+}
+
+static int loose_backend__read_prefix(
+	git_oid *out_oid,
+	void **buffer_p,
+	size_t *len_p,
+	git_otype *type_p,
+	git_odb_backend *backend,
+	const git_oid *short_oid,
+	size_t len)
+{
+	int error = 0;
+
+	assert(len >= GIT_OID_MINPREFIXLEN && len <= GIT_OID_HEXSZ);
+
+	if (len == GIT_OID_HEXSZ) {
+		/* We can fall back to regular read method */
+		error = loose_backend__read(buffer_p, len_p, type_p, backend, short_oid);
+		if (!error)
+			git_oid_cpy(out_oid, short_oid);
+	} else {
+		git_buf object_path = GIT_BUF_INIT;
+		git_rawobj raw;
+
+		assert(backend && short_oid);
+
+		if ((error = locate_object_short_oid(&object_path, out_oid,
+				(loose_backend *)backend, short_oid, len)) == 0 &&
+			(error = read_loose(&raw, &object_path)) == 0)
+		{
+			*buffer_p = raw.data;
+			*len_p = raw.len;
+			*type_p = raw.type;
+		}
+
+		git_buf_free(&object_path);
+	}
+
+	return error;
+}
+
+static int loose_backend__exists(git_odb_backend *backend, const git_oid *oid)
+{
+	git_buf object_path = GIT_BUF_INIT;
+	int error;
+
+	assert(backend && oid);
+
+	error = locate_object(&object_path, (loose_backend *)backend, oid);
+
+	git_buf_free(&object_path);
+
+	return !error;
+}
+
+static int loose_backend__exists_prefix(
+	git_oid *out, git_odb_backend *backend, const git_oid *short_id, size_t len)
+{
+	git_buf object_path = GIT_BUF_INIT;
+	int error;
+
+	assert(backend && out && short_id && len >= GIT_OID_MINPREFIXLEN);
+
+	error = locate_object_short_oid(
+		&object_path, out, (loose_backend *)backend, short_id, len);
+
+	git_buf_free(&object_path);
+
+	return error;
+}
+
+struct foreach_state {
+	size_t dir_len;
+	git_odb_foreach_cb cb;
+	void *data;
+};
+
+GIT_INLINE(int) filename_to_oid(git_oid *oid, const char *ptr)
+{
+	int v, i = 0;
+	if (strlen(ptr) != GIT_OID_HEXSZ+1)
+		return -1;
+
+	if (ptr[2] != '/') {
+		return -1;
+	}
+
+	v = (git__fromhex(ptr[i]) << 4) | git__fromhex(ptr[i+1]);
+	if (v < 0)
+		return -1;
+
+	oid->id[0] = (unsigned char) v;
+
+	ptr += 3;
+	for (i = 0; i < 38; i += 2) {
+		v = (git__fromhex(ptr[i]) << 4) | git__fromhex(ptr[i + 1]);
+		if (v < 0)
+			return -1;
+
+		oid->id[1 + i/2] = (unsigned char) v;
+	}
+
+	return 0;
+}
+
+static int foreach_object_dir_cb(void *_state, git_buf *path)
+{
+	git_oid oid;
+	struct foreach_state *state = (struct foreach_state *) _state;
+
+	if (filename_to_oid(&oid, path->ptr + state->dir_len) < 0)
+		return 0;
+
+	return giterr_set_after_callback_function(
+		state->cb(&oid, state->data), "git_odb_foreach");
+}
+
+static int foreach_cb(void *_state, git_buf *path)
+{
+	struct foreach_state *state = (struct foreach_state *) _state;
+
+	/* non-dir is some stray file, ignore it */
+	if (!git_path_isdir(git_buf_cstr(path)))
+		return 0;
+
+	return git_path_direach(path, 0, foreach_object_dir_cb, state);
+}
+
+static int loose_backend__foreach(git_odb_backend *_backend, git_odb_foreach_cb cb, void *data)
+{
+	char *objects_dir;
+	int error;
+	git_buf buf = GIT_BUF_INIT;
+	struct foreach_state state;
+	loose_backend *backend = (loose_backend *) _backend;
+
+	assert(backend && cb);
+
+	objects_dir = backend->objects_dir;
+
+	git_buf_sets(&buf, objects_dir);
+	git_path_to_dir(&buf);
+	if (git_buf_oom(&buf))
+		return -1;
+
+	memset(&state, 0, sizeof(state));
+	state.cb = cb;
+	state.data = data;
+	state.dir_len = git_buf_len(&buf);
+
+	error = git_path_direach(&buf, 0, foreach_cb, &state);
+
+	git_buf_free(&buf);
+
+	return error;
+}
+
+static int loose_backend__writestream_finalize(git_odb_stream *_stream, const git_oid *oid)
+{
+	loose_writestream *stream = (loose_writestream *)_stream;
+	loose_backend *backend = (loose_backend *)_stream->backend;
+	git_buf final_path = GIT_BUF_INIT;
+	int error = 0;
+
+	if (object_file_name(&final_path, backend, oid) < 0 ||
+		object_mkdir(&final_path, backend) < 0)
+		error = -1;
+	else
+		error = git_filebuf_commit_at(
+			&stream->fbuf, final_path.ptr);
+
+	git_buf_free(&final_path);
+
+	return error;
+}
+
+static int loose_backend__writestream_write(git_odb_stream *_stream, const char *data, size_t len)
+{
+	loose_writestream *stream = (loose_writestream *)_stream;
+	return git_filebuf_write(&stream->fbuf, data, len);
+}
+
+static void loose_backend__writestream_free(git_odb_stream *_stream)
+{
+	loose_writestream *stream = (loose_writestream *)_stream;
+
+	git_filebuf_cleanup(&stream->fbuf);
+	git__free(stream);
+}
+
+static int filebuf_flags(loose_backend *backend)
+{
+	int flags = GIT_FILEBUF_TEMPORARY |
+		(backend->object_zlib_level << GIT_FILEBUF_DEFLATE_SHIFT);
+
+	if (backend->fsync_object_files || git_repository__fsync_gitdir)
+		flags |= GIT_FILEBUF_FSYNC;
+
+	return flags;
+}
+
+static int loose_backend__writestream(git_odb_stream **stream_out, git_odb_backend *_backend, git_off_t length, git_otype type)
+{
+	loose_backend *backend;
+	loose_writestream *stream = NULL;
+	char hdr[MAX_HEADER_LEN];
+	git_buf tmp_path = GIT_BUF_INIT;
+	size_t hdrlen;
+	int error;
+
+	assert(_backend && length >= 0);
+
+	backend = (loose_backend *)_backend;
+	*stream_out = NULL;
+
+	if ((error = git_odb__format_object_header(&hdrlen,
+		hdr, sizeof(hdr), length, type)) < 0)
+		return error;
+
+	stream = git__calloc(1, sizeof(loose_writestream));
+	GITERR_CHECK_ALLOC(stream);
+
+	stream->stream.backend = _backend;
+	stream->stream.read = NULL; /* read only */
+	stream->stream.write = &loose_backend__writestream_write;
+	stream->stream.finalize_write = &loose_backend__writestream_finalize;
+	stream->stream.free = &loose_backend__writestream_free;
+	stream->stream.mode = GIT_STREAM_WRONLY;
+
+	if (git_buf_joinpath(&tmp_path, backend->objects_dir, "tmp_object") < 0 ||
+		git_filebuf_open(&stream->fbuf, tmp_path.ptr, filebuf_flags(backend),
+			backend->object_file_mode) < 0 ||
+		stream->stream.write((git_odb_stream *)stream, hdr, hdrlen) < 0)
+	{
+		git_filebuf_cleanup(&stream->fbuf);
+		git__free(stream);
+		stream = NULL;
+	}
+	git_buf_free(&tmp_path);
+	*stream_out = (git_odb_stream *)stream;
+
+	return !stream ? -1 : 0;
+}
+
+static int loose_backend__readstream_read(
+	git_odb_stream *_stream,
+	char *buffer,
+	size_t buffer_len)
+{
+	loose_readstream *stream = (loose_readstream *)_stream;
+	size_t start_remain = stream->start_len - stream->start_read;
+	int total = 0, error;
+
+	/*
+	 * if we read more than just the header in the initial read, play
+	 * that back for the caller.
+	 */
+	if (start_remain && buffer_len) {
+		size_t chunk = min(start_remain, buffer_len);
+		memcpy(buffer, stream->start + stream->start_read, chunk);
+
+		buffer += chunk;
+		stream->start_read += chunk;
+
+		total += chunk;
+		buffer_len -= chunk;
+	}
+
+	if (buffer_len) {
+		size_t chunk = min(buffer_len, INT_MAX);
+
+		if ((error = git_zstream_get_output(buffer, &chunk, &stream->zstream)) < 0)
+			return error;
+
+		total += chunk;
+	}
+
+	return total;
+}
+
+static void loose_backend__readstream_free(git_odb_stream *_stream)
+{
+	loose_readstream *stream = (loose_readstream *)_stream;
+
+	git_futils_mmap_free(&stream->map);
+	git_zstream_free(&stream->zstream);
+	git__free(stream);
+}
+
+static int loose_backend__readstream_packlike(
+	obj_hdr *hdr,
+	loose_readstream *stream)
+{
+	const unsigned char *data;
+	size_t data_len, head_len;
+	int error;
+
+	data = stream->map.data;
+	data_len = stream->map.len;
+
+	/*
+	 * read the object header, which is an (uncompressed)
+	 * binary encoding of the object type and size.
+	 */
+	if ((error = parse_header_packlike(hdr, &head_len, data, data_len)) < 0)
+		return error;
+
+	if (!git_object_typeisloose(hdr->type)) {
+		giterr_set(GITERR_ODB, "failed to inflate loose object");
+		return -1;
+	}
+
+	return git_zstream_set_input(&stream->zstream,
+		data + head_len, data_len - head_len);
+}
+
+static int loose_backend__readstream_standard(
+	obj_hdr *hdr,
+	loose_readstream *stream)
+{
+	unsigned char head[MAX_HEADER_LEN];
+	size_t init, head_len;
+	int error;
+
+	if ((error = git_zstream_set_input(&stream->zstream,
+			stream->map.data, stream->map.len)) < 0)
+		return error;
+
+	init = sizeof(head);
+
+	/*
+	 * inflate the initial part of the compressed buffer in order to
+	 * parse the header; read the largest header possible, then store
+	 * it in the `start` field of the stream object.
+	 */
+	if ((error = git_zstream_get_output(head, &init, &stream->zstream)) < 0 ||
+		(error = parse_header(hdr, &head_len, head, init)) < 0)
+		return error;
+
+	if (!git_object_typeisloose(hdr->type)) {
+		giterr_set(GITERR_ODB, "failed to inflate disk object");
+		return -1;
+	}
+
+	if (init > head_len) {
+		stream->start_len = init - head_len;
+		memcpy(stream->start, head + head_len, init - head_len);
+	}
+
+	return 0;
+}
+
+static int loose_backend__readstream(
+	git_odb_stream **stream_out,
+	size_t *len_out,
+	git_otype *type_out,
+	git_odb_backend *_backend,
+	const git_oid *oid)
+{
+	loose_backend *backend;
+	loose_readstream *stream = NULL;
+	git_hash_ctx *hash_ctx = NULL;
+	git_buf object_path = GIT_BUF_INIT;
+	obj_hdr hdr;
+	int error = 0;
+
+	assert(stream_out && len_out && type_out && _backend && oid);
+
+	backend = (loose_backend *)_backend;
+	*stream_out = NULL;
+	*len_out = 0;
+	*type_out = GIT_OBJ_BAD;
+
+	if (locate_object(&object_path, backend, oid) < 0) {
+		error = git_odb__error_notfound("no matching loose object",
+			oid, GIT_OID_HEXSZ);
+		goto done;
+	}
+
+	stream = git__calloc(1, sizeof(loose_readstream));
+	GITERR_CHECK_ALLOC(stream);
+
+	hash_ctx = git__malloc(sizeof(git_hash_ctx));
+	GITERR_CHECK_ALLOC(hash_ctx);
+
+	if ((error = git_hash_ctx_init(hash_ctx)) < 0 ||
+		(error = git_futils_mmap_ro_file(&stream->map, object_path.ptr)) < 0 ||
+		(error = git_zstream_init(&stream->zstream, GIT_ZSTREAM_INFLATE)) < 0)
+		goto done;
+
+	/* check for a packlike loose object */
+	if (!is_zlib_compressed_data(stream->map.data, stream->map.len))
+		error = loose_backend__readstream_packlike(&hdr, stream);
+	else
+		error = loose_backend__readstream_standard(&hdr, stream);
+
+	if (error < 0)
+		goto done;
+
+	stream->stream.backend = _backend;
+	stream->stream.hash_ctx = hash_ctx;
+	stream->stream.read = &loose_backend__readstream_read;
+	stream->stream.free = &loose_backend__readstream_free;
+
+	*stream_out = (git_odb_stream *)stream;
+	*len_out = hdr.size;
+	*type_out = hdr.type;
+
+done:
+	if (error < 0) {
+		git_futils_mmap_free(&stream->map);
+		git_zstream_free(&stream->zstream);
+		git_hash_ctx_cleanup(hash_ctx);
+		git__free(hash_ctx);
+		git__free(stream);
+	}
+
+	git_buf_free(&object_path);
+	return error;
+}
+
+static int loose_backend__write(git_odb_backend *_backend, const git_oid *oid, const void *data, size_t len, git_otype type)
+{
+	int error = 0;
+	git_buf final_path = GIT_BUF_INIT;
+	char header[MAX_HEADER_LEN];
+	size_t header_len;
+	git_filebuf fbuf = GIT_FILEBUF_INIT;
+	loose_backend *backend;
+
+	backend = (loose_backend *)_backend;
+
+	/* prepare the header for the file */
+	if ((error = git_odb__format_object_header(&header_len,
+		header, sizeof(header), len, type)) < 0)
+		goto cleanup;
+
+	if (git_buf_joinpath(&final_path, backend->objects_dir, "tmp_object") < 0 ||
+		git_filebuf_open(&fbuf, final_path.ptr, filebuf_flags(backend),
+			backend->object_file_mode) < 0)
+	{
+		error = -1;
+		goto cleanup;
+	}
+
+	git_filebuf_write(&fbuf, header, header_len);
+	git_filebuf_write(&fbuf, data, len);
+
+	if (object_file_name(&final_path, backend, oid) < 0 ||
+		object_mkdir(&final_path, backend) < 0 ||
+		git_filebuf_commit_at(&fbuf, final_path.ptr) < 0)
+		error = -1;
+
+cleanup:
+	if (error < 0)
+		git_filebuf_cleanup(&fbuf);
+	git_buf_free(&final_path);
+	return error;
+}
+
+static int loose_backend__freshen(
+	git_odb_backend *_backend,
+	const git_oid *oid)
+{
+	loose_backend *backend = (loose_backend *)_backend;
+	git_buf path = GIT_BUF_INIT;
+	int error;
+
+	if (object_file_name(&path, backend, oid) < 0)
+		return -1;
+
+	error = git_futils_touch(path.ptr, NULL);
+	git_buf_free(&path);
+
+	return error;
+}
+
+static void loose_backend__free(git_odb_backend *_backend)
+{
+	loose_backend *backend;
+	assert(_backend);
+	backend = (loose_backend *)_backend;
+
+	git__free(backend);
+}
+
+int git_odb_backend_loose(
+	git_odb_backend **backend_out,
+	const char *objects_dir,
+	int compression_level,
+	int do_fsync,
+	unsigned int dir_mode,
+	unsigned int file_mode)
+{
+	loose_backend *backend;
+	size_t objects_dirlen, alloclen;
+
+	assert(backend_out && objects_dir);
+
+	objects_dirlen = strlen(objects_dir);
+
+	GITERR_CHECK_ALLOC_ADD(&alloclen, sizeof(loose_backend), objects_dirlen);
+	GITERR_CHECK_ALLOC_ADD(&alloclen, alloclen, 2);
+	backend = git__calloc(1, alloclen);
+	GITERR_CHECK_ALLOC(backend);
+
+	backend->parent.version = GIT_ODB_BACKEND_VERSION;
+	backend->objects_dirlen = objects_dirlen;
+	memcpy(backend->objects_dir, objects_dir, objects_dirlen);
+	if (backend->objects_dir[backend->objects_dirlen - 1] != '/')
+		backend->objects_dir[backend->objects_dirlen++] = '/';
+
+	if (compression_level < 0)
+		compression_level = Z_BEST_SPEED;
+
+	if (dir_mode == 0)
+		dir_mode = GIT_OBJECT_DIR_MODE;
+
+	if (file_mode == 0)
+		file_mode = GIT_OBJECT_FILE_MODE;
+
+	backend->object_zlib_level = compression_level;
+	backend->fsync_object_files = do_fsync;
+	backend->object_dir_mode = dir_mode;
+	backend->object_file_mode = file_mode;
+
+	backend->parent.read = &loose_backend__read;
+	backend->parent.write = &loose_backend__write;
+	backend->parent.read_prefix = &loose_backend__read_prefix;
+	backend->parent.read_header = &loose_backend__read_header;
+	backend->parent.writestream = &loose_backend__writestream;
+	backend->parent.readstream = &loose_backend__readstream;
+	backend->parent.exists = &loose_backend__exists;
+	backend->parent.exists_prefix = &loose_backend__exists_prefix;
+	backend->parent.foreach = &loose_backend__foreach;
+	backend->parent.freshen = &loose_backend__freshen;
+	backend->parent.free = &loose_backend__free;
+
+	*backend_out = (git_odb_backend *)backend;
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/odb_mempack.c

diff --git a/vendor/libgit2-sys/libgit2/src/odb_mempack.c b/vendor/libgit2-sys/libgit2/src/odb_mempack.c
new file mode 100644
index 0000000..e351d4d
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/odb_mempack.c
@@ -0,0 +1,185 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "git2/object.h"
+#include "git2/sys/odb_backend.h"
+#include "git2/sys/mempack.h"
+#include "fileops.h"
+#include "hash.h"
+#include "odb.h"
+#include "array.h"
+#include "oidmap.h"
+
+#include "git2/odb_backend.h"
+#include "git2/types.h"
+#include "git2/pack.h"
+
+struct memobject {
+	git_oid oid;
+	size_t len;
+	git_otype type;
+	char data[GIT_FLEX_ARRAY];
+};
+
+struct memory_packer_db {
+	git_odb_backend parent;
+	git_oidmap *objects;
+	git_array_t(struct memobject *) commits;
+};
+
+static int impl__write(git_odb_backend *_backend, const git_oid *oid, const void *data, size_t len, git_otype type)
+{
+	struct memory_packer_db *db = (struct memory_packer_db *)_backend;
+	struct memobject *obj = NULL; 
+	khiter_t pos;
+	size_t alloc_len;
+	int rval;
+
+	pos = git_oidmap_put(db->objects, oid, &rval);
+	if (rval < 0)
+		return -1;
+
+	if (rval == 0)
+		return 0;
+
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, sizeof(struct memobject), len);
+	obj = git__malloc(alloc_len);
+	GITERR_CHECK_ALLOC(obj);
+
+	memcpy(obj->data, data, len);
+	git_oid_cpy(&obj->oid, oid);
+	obj->len = len;
+	obj->type = type;
+
+	git_oidmap_set_key_at(db->objects, pos, &obj->oid);
+	git_oidmap_set_value_at(db->objects, pos, obj);
+
+	if (type == GIT_OBJ_COMMIT) {
+		struct memobject **store = git_array_alloc(db->commits);
+		GITERR_CHECK_ALLOC(store);
+		*store = obj;
+	}
+
+	return 0;
+}
+
+static int impl__exists(git_odb_backend *backend, const git_oid *oid)
+{
+	struct memory_packer_db *db = (struct memory_packer_db *)backend;
+
+	return git_oidmap_exists(db->objects, oid);
+}
+
+static int impl__read(void **buffer_p, size_t *len_p, git_otype *type_p, git_odb_backend *backend, const git_oid *oid)
+{
+	struct memory_packer_db *db = (struct memory_packer_db *)backend;
+	struct memobject *obj = NULL;
+	khiter_t pos;
+
+	pos = git_oidmap_lookup_index(db->objects, oid);
+	if (!git_oidmap_valid_index(db->objects, pos))
+		return GIT_ENOTFOUND;
+
+	obj = git_oidmap_value_at(db->objects, pos);
+
+	*len_p = obj->len;
+	*type_p = obj->type;
+	*buffer_p = git__malloc(obj->len);
+	GITERR_CHECK_ALLOC(*buffer_p);
+
+	memcpy(*buffer_p, obj->data, obj->len);
+	return 0;
+}
+
+static int impl__read_header(size_t *len_p, git_otype *type_p, git_odb_backend *backend, const git_oid *oid)
+{
+	struct memory_packer_db *db = (struct memory_packer_db *)backend;
+	struct memobject *obj = NULL;
+	khiter_t pos;
+
+	pos = git_oidmap_lookup_index(db->objects, oid);
+	if (!git_oidmap_valid_index(db->objects, pos))
+		return GIT_ENOTFOUND;
+
+	obj = git_oidmap_value_at(db->objects, pos);
+
+	*len_p = obj->len;
+	*type_p = obj->type;
+	return 0;
+}
+
+int git_mempack_dump(git_buf *pack, git_repository *repo, git_odb_backend *_backend)
+{
+	struct memory_packer_db *db = (struct memory_packer_db *)_backend;
+	git_packbuilder *packbuilder;
+	uint32_t i;
+	int err = -1;
+
+	if (git_packbuilder_new(&packbuilder, repo) < 0)
+		return -1;
+
+	for (i = 0; i < db->commits.size; ++i) {
+		struct memobject *commit = db->commits.ptr[i];
+
+		err = git_packbuilder_insert_commit(packbuilder, &commit->oid);
+		if (err < 0)
+			goto cleanup;
+	}
+
+	err = git_packbuilder_write_buf(pack, packbuilder);
+
+cleanup:
+	git_packbuilder_free(packbuilder);
+	return err;
+}
+
+void git_mempack_reset(git_odb_backend *_backend)
+{
+	struct memory_packer_db *db = (struct memory_packer_db *)_backend;
+	struct memobject *object = NULL;
+
+	git_oidmap_foreach_value(db->objects, object, {
+		git__free(object);
+	});
+
+	git_array_clear(db->commits);
+
+	git_oidmap_clear(db->objects);
+}
+
+static void impl__free(git_odb_backend *_backend)
+{
+	struct memory_packer_db *db = (struct memory_packer_db *)_backend;
+
+	git_mempack_reset(_backend);
+	git_oidmap_free(db->objects);
+	git__free(db);
+}
+
+int git_mempack_new(git_odb_backend **out)
+{
+	struct memory_packer_db *db;
+
+	assert(out);
+
+	db = git__calloc(1, sizeof(struct memory_packer_db));
+	GITERR_CHECK_ALLOC(db);
+
+	db->objects = git_oidmap_alloc();
+
+	db->parent.version = GIT_ODB_BACKEND_VERSION;
+	db->parent.read = &impl__read;
+	db->parent.write = &impl__write;
+	db->parent.read_header = &impl__read_header;
+	db->parent.exists = &impl__exists;
+	db->parent.free = &impl__free;
+
+	*out = (git_odb_backend *)db;
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/odb_pack.c

diff --git a/vendor/libgit2-sys/libgit2/src/odb_pack.c b/vendor/libgit2-sys/libgit2/src/odb_pack.c
new file mode 100644
index 0000000..20aff53
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/odb_pack.c
@@ -0,0 +1,641 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include <zlib.h>
+#include "git2/repository.h"
+#include "git2/indexer.h"
+#include "git2/sys/odb_backend.h"
+#include "fileops.h"
+#include "hash.h"
+#include "odb.h"
+#include "delta.h"
+#include "sha1_lookup.h"
+#include "mwindow.h"
+#include "pack.h"
+
+#include "git2/odb_backend.h"
+
+/* re-freshen pack files no more than every 2 seconds */
+#define FRESHEN_FREQUENCY 2
+
+struct pack_backend {
+	git_odb_backend parent;
+	git_vector packs;
+	struct git_pack_file *last_found;
+	char *pack_folder;
+};
+
+struct pack_writepack {
+	struct git_odb_writepack parent;
+	git_indexer *indexer;
+};
+
+/**
+ * The wonderful tale of a Packed Object lookup query
+ * ===================================================
+ *	A riveting and epic story of epicness and ASCII
+ *			art, presented by yours truly,
+ *				Sir Vicent of Marti
+ *
+ *
+ *	Chapter 1: Once upon a time...
+ *	Initialization of the Pack Backend
+ *	--------------------------------------------------
+ *
+ *	# git_odb_backend_pack
+ *	| Creates the pack backend structure, initializes the
+ *	| callback pointers to our default read() and exist() methods,
+ *	| and tries to preload all the known packfiles in the ODB.
+ * |
+ *	|-# packfile_load_all
+ *	 | Tries to find the `pack` folder, if it exists. ODBs without
+ *	 | a pack folder are ignored altogether. If there's a `pack` folder
+ *	 | we run a `dirent` callback through every file in the pack folder
+ *	 | to find our packfiles. The packfiles are then sorted according
+ *	 | to a sorting callback.
+ * 	 |
+ *	 |-# packfile_load__cb
+ *	 | | This callback is called from `dirent` with every single file
+ *	 | | inside the pack folder. We find the packs by actually locating
+ *	 | | their index (ends in ".idx"). From that index, we verify that
+ *	 | | the corresponding packfile exists and is valid, and if so, we
+ *	| | add it to the pack list.
+ *	 | |
+ *	 | |-# packfile_check
+ *	 |		Make sure that there's a packfile to back this index, and store
+ *	 |		some very basic information regarding the packfile itself,
+ *	 |		such as the full path, the size, and the modification time.
+ *	 |		We don't actually open the packfile to check for internal consistency.
+ *	|
+ *	|-# packfile_sort__cb
+ *		Sort all the preloaded packs according to some specific criteria:
+ *		we prioritize the "newer" packs because it's more likely they
+ *		contain the objects we are looking for, and we prioritize local
+ *		packs over remote ones.
+ *
+ *
+ *
+ *	Chapter 2: To be, or not to be...
+ *	A standard packed `exist` query for an OID
+ *	--------------------------------------------------
+ *
+ * # pack_backend__exists
+ * | Check if the given SHA1 oid exists in any of the packs
+ * | that have been loaded for our ODB.
+ * |
+ * |-# pack_entry_find
+ *	| Iterate through all the packs that have been preloaded
+ *	| (starting by the pack where the latest object was found)
+ *	| to try to find the OID in one of them.
+ *	|
+ *	|-# pack_entry_find1
+ *		| Check the index of an individual pack to see if the SHA1
+ *		| OID can be found. If we can find the offset to that SHA1
+ *		| inside of the index, that means the object is contained
+ *		| inside of the packfile and we can stop searching.
+ *		| Before returning, we verify that the packfile behing the
+ *		| index we are searching still exists on disk.
+ *		|
+ *		|-# pack_entry_find_offset
+ *		| | Mmap the actual index file to disk if it hasn't been opened
+ *		| | yet, and run a binary search through it to find the OID.
+ *		| | See <http://book.git-scm.com/7_the_packfile.html> for specifics
+ *		| | on the Packfile Index format and how do we find entries in it.
+ *		| |
+ *		| |-# pack_index_open
+ *		|	| Guess the name of the index based on the full path to the
+ *		|	| packfile, open it and verify its contents. Only if the index
+ *		|	| has not been opened already.
+ *		|	|
+ *		|	|-# pack_index_check
+ *		|		Mmap the index file and do a quick run through the header
+ *		|		to guess the index version (right now we support v1 and v2),
+ *		|		and to verify that the size of the index makes sense.
+ *		|
+ *		|-# packfile_open
+ *			See `packfile_open` in Chapter 3
+ *
+ *
+ *
+ *	Chapter 3: The neverending story...
+ *	A standard packed `lookup` query for an OID
+ *	--------------------------------------------------
+ *	TODO
+ *
+ */
+
+
+/***********************************************************
+ *
+ * FORWARD DECLARATIONS
+ *
+ ***********************************************************/
+
+static int packfile_sort__cb(const void *a_, const void *b_);
+
+static int packfile_load__cb(void *_data, git_buf *path);
+
+static int pack_entry_find(struct git_pack_entry *e,
+	struct pack_backend *backend, const git_oid *oid);
+
+/* Can find the offset of an object given
+ * a prefix of an identifier.
+ * Sets GIT_EAMBIGUOUS if short oid is ambiguous.
+ * This method assumes that len is between
+ * GIT_OID_MINPREFIXLEN and GIT_OID_HEXSZ.
+ */
+static int pack_entry_find_prefix(
+	struct git_pack_entry *e,
+	struct pack_backend *backend,
+	const git_oid *short_oid,
+	size_t len);
+
+
+
+/***********************************************************
+ *
+ * PACK WINDOW MANAGEMENT
+ *
+ ***********************************************************/
+
+static int packfile_sort__cb(const void *a_, const void *b_)
+{
+	const struct git_pack_file *a = a_;
+	const struct git_pack_file *b = b_;
+	int st;
+
+	/*
+	 * Local packs tend to contain objects specific to our
+	 * variant of the project than remote ones. In addition,
+	 * remote ones could be on a network mounted filesystem.
+	 * Favor local ones for these reasons.
+	 */
+	st = a->pack_local - b->pack_local;
+	if (st)
+		return -st;
+
+	/*
+	 * Younger packs tend to contain more recent objects,
+	 * and more recent objects tend to get accessed more
+	 * often.
+	 */
+	if (a->mtime < b->mtime)
+		return 1;
+	else if (a->mtime == b->mtime)
+		return 0;
+
+	return -1;
+}
+
+
+static int packfile_load__cb(void *data, git_buf *path)
+{
+	struct pack_backend *backend = data;
+	struct git_pack_file *pack;
+	const char *path_str = git_buf_cstr(path);
+	size_t i, cmp_len = git_buf_len(path);
+	int error;
+
+	if (cmp_len <= strlen(".idx") || git__suffixcmp(path_str, ".idx") != 0)
+		return 0; /* not an index */
+
+	cmp_len -= strlen(".idx");
+
+	for (i = 0; i < backend->packs.length; ++i) {
+		struct git_pack_file *p = git_vector_get(&backend->packs, i);
+
+		if (memcmp(p->pack_name, path_str, cmp_len) == 0)
+			return 0;
+	}
+
+	error = git_mwindow_get_pack(&pack, path->ptr);
+
+	/* ignore missing .pack file as git does */
+	if (error == GIT_ENOTFOUND) {
+		giterr_clear();
+		return 0;
+	}
+
+	if (!error)
+		error = git_vector_insert(&backend->packs, pack);
+
+	return error;
+
+}
+
+static int pack_entry_find_inner(
+	struct git_pack_entry *e,
+	struct pack_backend *backend,
+	const git_oid *oid,
+	struct git_pack_file *last_found)
+{
+	size_t i;
+
+	if (last_found &&
+		git_pack_entry_find(e, last_found, oid, GIT_OID_HEXSZ) == 0)
+		return 0;
+
+	for (i = 0; i < backend->packs.length; ++i) {
+		struct git_pack_file *p;
+
+		p = git_vector_get(&backend->packs, i);
+		if (p == last_found)
+			continue;
+
+		if (git_pack_entry_find(e, p, oid, GIT_OID_HEXSZ) == 0) {
+			backend->last_found = p;
+			return 0;
+		}
+	}
+
+	return -1;
+}
+
+static int pack_entry_find(struct git_pack_entry *e, struct pack_backend *backend, const git_oid *oid)
+{
+	struct git_pack_file *last_found = backend->last_found;
+
+	if (backend->last_found &&
+		git_pack_entry_find(e, backend->last_found, oid, GIT_OID_HEXSZ) == 0)
+		return 0;
+
+	if (!pack_entry_find_inner(e, backend, oid, last_found))
+		return 0;
+
+	return git_odb__error_notfound(
+		"failed to find pack entry", oid, GIT_OID_HEXSZ);
+}
+
+static int pack_entry_find_prefix(
+	struct git_pack_entry *e,
+	struct pack_backend *backend,
+	const git_oid *short_oid,
+	size_t len)
+{
+	int error;
+	size_t i;
+	git_oid found_full_oid = {{0}};
+	bool found = false;
+	struct git_pack_file *last_found = backend->last_found;
+
+	if (last_found) {
+		error = git_pack_entry_find(e, last_found, short_oid, len);
+		if (error == GIT_EAMBIGUOUS)
+			return error;
+		if (!error) {
+			git_oid_cpy(&found_full_oid, &e->sha1);
+			found = true;
+		}
+	}
+
+	for (i = 0; i < backend->packs.length; ++i) {
+		struct git_pack_file *p;
+
+		p = git_vector_get(&backend->packs, i);
+		if (p == last_found)
+			continue;
+
+		error = git_pack_entry_find(e, p, short_oid, len);
+		if (error == GIT_EAMBIGUOUS)
+			return error;
+		if (!error) {
+			if (found && git_oid_cmp(&e->sha1, &found_full_oid))
+				return git_odb__error_ambiguous("found multiple pack entries");
+			git_oid_cpy(&found_full_oid, &e->sha1);
+			found = true;
+			backend->last_found = p;
+		}
+	}
+
+	if (!found)
+		return git_odb__error_notfound("no matching pack entry for prefix",
+			short_oid, len);
+	else
+		return 0;
+}
+
+
+/***********************************************************
+ *
+ * PACKED BACKEND PUBLIC API
+ *
+ * Implement the git_odb_backend API calls
+ *
+ ***********************************************************/
+static int pack_backend__refresh(git_odb_backend *backend_)
+{
+	int error;
+	struct stat st;
+	git_buf path = GIT_BUF_INIT;
+	struct pack_backend *backend = (struct pack_backend *)backend_;
+
+	if (backend->pack_folder == NULL)
+		return 0;
+
+	if (p_stat(backend->pack_folder, &st) < 0 || !S_ISDIR(st.st_mode))
+		return git_odb__error_notfound("failed to refresh packfiles", NULL, 0);
+
+	git_buf_sets(&path, backend->pack_folder);
+
+	/* reload all packs */
+	error = git_path_direach(&path, 0, packfile_load__cb, backend);
+
+	git_buf_free(&path);
+	git_vector_sort(&backend->packs);
+
+	return error;
+}
+
+static int pack_backend__read_header(
+	size_t *len_p, git_otype *type_p,
+	struct git_odb_backend *backend, const git_oid *oid)
+{
+	struct git_pack_entry e;
+	int error;
+
+	assert(len_p && type_p && backend && oid);
+
+	if ((error = pack_entry_find(&e, (struct pack_backend *)backend, oid)) < 0)
+		return error;
+
+	return git_packfile_resolve_header(len_p, type_p, e.p, e.offset);
+}
+
+static int pack_backend__freshen(
+	git_odb_backend *backend, const git_oid *oid)
+{
+	struct git_pack_entry e;
+	time_t now;
+	int error;
+
+	if ((error = pack_entry_find(&e, (struct pack_backend *)backend, oid)) < 0)
+		return error;
+
+	now = time(NULL);
+
+	if (e.p->last_freshen > now - FRESHEN_FREQUENCY)
+		return 0;
+
+	if ((error = git_futils_touch(e.p->pack_name, &now)) < 0)
+		return error;
+
+	e.p->last_freshen = now;
+	return 0;
+}
+
+static int pack_backend__read(
+	void **buffer_p, size_t *len_p, git_otype *type_p,
+	git_odb_backend *backend, const git_oid *oid)
+{
+	struct git_pack_entry e;
+	git_rawobj raw = {NULL};
+	int error;
+
+	if ((error = pack_entry_find(&e, (struct pack_backend *)backend, oid)) < 0 ||
+		(error = git_packfile_unpack(&raw, e.p, &e.offset)) < 0)
+		return error;
+
+	*buffer_p = raw.data;
+	*len_p = raw.len;
+	*type_p = raw.type;
+
+	return 0;
+}
+
+static int pack_backend__read_prefix(
+	git_oid *out_oid,
+	void **buffer_p,
+	size_t *len_p,
+	git_otype *type_p,
+	git_odb_backend *backend,
+	const git_oid *short_oid,
+	size_t len)
+{
+	int error = 0;
+
+	if (len < GIT_OID_MINPREFIXLEN)
+		error = git_odb__error_ambiguous("prefix length too short");
+
+	else if (len >= GIT_OID_HEXSZ) {
+		/* We can fall back to regular read method */
+		error = pack_backend__read(buffer_p, len_p, type_p, backend, short_oid);
+		if (!error)
+			git_oid_cpy(out_oid, short_oid);
+	} else {
+		struct git_pack_entry e;
+		git_rawobj raw = {NULL};
+
+		if ((error = pack_entry_find_prefix(
+				&e, (struct pack_backend *)backend, short_oid, len)) == 0 &&
+			(error = git_packfile_unpack(&raw, e.p, &e.offset)) == 0)
+		{
+			*buffer_p = raw.data;
+			*len_p = raw.len;
+			*type_p = raw.type;
+			git_oid_cpy(out_oid, &e.sha1);
+		}
+	}
+
+	return error;
+}
+
+static int pack_backend__exists(git_odb_backend *backend, const git_oid *oid)
+{
+	struct git_pack_entry e;
+	return pack_entry_find(&e, (struct pack_backend *)backend, oid) == 0;
+}
+
+static int pack_backend__exists_prefix(
+	git_oid *out, git_odb_backend *backend, const git_oid *short_id, size_t len)
+{
+	int error;
+	struct pack_backend *pb = (struct pack_backend *)backend;
+	struct git_pack_entry e = {0};
+
+	error = pack_entry_find_prefix(&e, pb, short_id, len);
+	git_oid_cpy(out, &e.sha1);
+	return error;
+}
+
+static int pack_backend__foreach(git_odb_backend *_backend, git_odb_foreach_cb cb, void *data)
+{
+	int error;
+	struct git_pack_file *p;
+	struct pack_backend *backend;
+	unsigned int i;
+
+	assert(_backend && cb);
+	backend = (struct pack_backend *)_backend;
+
+	/* Make sure we know about the packfiles */
+	if ((error = pack_backend__refresh(_backend)) < 0)
+		return error;
+
+	git_vector_foreach(&backend->packs, i, p) {
+		if ((error = git_pack_foreach_entry(p, cb, data)) < 0)
+			return error;
+	}
+
+	return 0;
+}
+
+static int pack_backend__writepack_append(struct git_odb_writepack *_writepack, const void *data, size_t size, git_transfer_progress *stats)
+{
+	struct pack_writepack *writepack = (struct pack_writepack *)_writepack;
+
+	assert(writepack);
+
+	return git_indexer_append(writepack->indexer, data, size, stats);
+}
+
+static int pack_backend__writepack_commit(struct git_odb_writepack *_writepack, git_transfer_progress *stats)
+{
+	struct pack_writepack *writepack = (struct pack_writepack *)_writepack;
+
+	assert(writepack);
+
+	return git_indexer_commit(writepack->indexer, stats);
+}
+
+static void pack_backend__writepack_free(struct git_odb_writepack *_writepack)
+{
+	struct pack_writepack *writepack = (struct pack_writepack *)_writepack;
+
+	assert(writepack);
+
+	git_indexer_free(writepack->indexer);
+	git__free(writepack);
+}
+
+static int pack_backend__writepack(struct git_odb_writepack **out,
+	git_odb_backend *_backend,
+        git_odb *odb,
+	git_transfer_progress_cb progress_cb,
+	void *progress_payload)
+{
+	struct pack_backend *backend;
+	struct pack_writepack *writepack;
+
+	assert(out && _backend);
+
+	*out = NULL;
+
+	backend = (struct pack_backend *)_backend;
+
+	writepack = git__calloc(1, sizeof(struct pack_writepack));
+	GITERR_CHECK_ALLOC(writepack);
+
+	if (git_indexer_new(&writepack->indexer,
+		backend->pack_folder, 0, odb, progress_cb, progress_payload) < 0) {
+		git__free(writepack);
+		return -1;
+	}
+
+	writepack->parent.backend = _backend;
+	writepack->parent.append = pack_backend__writepack_append;
+	writepack->parent.commit = pack_backend__writepack_commit;
+	writepack->parent.free = pack_backend__writepack_free;
+
+	*out = (git_odb_writepack *)writepack;
+
+	return 0;
+}
+
+static void pack_backend__free(git_odb_backend *_backend)
+{
+	struct pack_backend *backend;
+	size_t i;
+
+	assert(_backend);
+
+	backend = (struct pack_backend *)_backend;
+
+	for (i = 0; i < backend->packs.length; ++i) {
+		struct git_pack_file *p = git_vector_get(&backend->packs, i);
+		git_mwindow_put_pack(p);
+	}
+
+	git_vector_free(&backend->packs);
+	git__free(backend->pack_folder);
+	git__free(backend);
+}
+
+static int pack_backend__alloc(struct pack_backend **out, size_t initial_size)
+{
+	struct pack_backend *backend = git__calloc(1, sizeof(struct pack_backend));
+	GITERR_CHECK_ALLOC(backend);
+
+	if (git_vector_init(&backend->packs, initial_size, packfile_sort__cb) < 0) {
+		git__free(backend);
+		return -1;
+	}
+
+	backend->parent.version = GIT_ODB_BACKEND_VERSION;
+
+	backend->parent.read = &pack_backend__read;
+	backend->parent.read_prefix = &pack_backend__read_prefix;
+	backend->parent.read_header = &pack_backend__read_header;
+	backend->parent.exists = &pack_backend__exists;
+	backend->parent.exists_prefix = &pack_backend__exists_prefix;
+	backend->parent.refresh = &pack_backend__refresh;
+	backend->parent.foreach = &pack_backend__foreach;
+	backend->parent.writepack = &pack_backend__writepack;
+	backend->parent.freshen = &pack_backend__freshen;
+	backend->parent.free = &pack_backend__free;
+
+	*out = backend;
+	return 0;
+}
+
+int git_odb_backend_one_pack(git_odb_backend **backend_out, const char *idx)
+{
+	struct pack_backend *backend = NULL;
+	struct git_pack_file *packfile = NULL;
+
+	if (pack_backend__alloc(&backend, 1) < 0)
+		return -1;
+
+	if (git_mwindow_get_pack(&packfile, idx) < 0 ||
+		git_vector_insert(&backend->packs, packfile) < 0)
+	{
+		pack_backend__free((git_odb_backend *)backend);
+		return -1;
+	}
+
+	*backend_out = (git_odb_backend *)backend;
+	return 0;
+}
+
+int git_odb_backend_pack(git_odb_backend **backend_out, const char *objects_dir)
+{
+	int error = 0;
+	struct pack_backend *backend = NULL;
+	git_buf path = GIT_BUF_INIT;
+
+	if (pack_backend__alloc(&backend, 8) < 0)
+		return -1;
+
+	if (!(error = git_buf_joinpath(&path, objects_dir, "pack")) &&
+		git_path_isdir(git_buf_cstr(&path)))
+	{
+		backend->pack_folder = git_buf_detach(&path);
+		error = pack_backend__refresh((git_odb_backend *)backend);
+	}
+
+	if (error < 0) {
+		pack_backend__free((git_odb_backend *)backend);
+		backend = NULL;
+	}
+
+	*backend_out = (git_odb_backend *)backend;
+
+	git_buf_free(&path);
+
+	return error;
+}

vendor/libgit2-sys/libgit2/src/offmap.c

diff --git a/vendor/libgit2-sys/libgit2/src/offmap.c b/vendor/libgit2-sys/libgit2/src/offmap.c
new file mode 100644
index 0000000..ab66496
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/offmap.c
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "offmap.h"
+
+__KHASH_IMPL(off, static kh_inline, git_off_t, void *, 1, kh_int64_hash_func, kh_int64_hash_equal)
+
+git_offmap *git_offmap_alloc(void)
+{
+	return kh_init(off);
+}
+
+void git_offmap_free(git_offmap *map)
+{
+	kh_destroy(off, map);
+}
+
+void git_offmap_clear(git_offmap *map)
+{
+	kh_clear(off, map);
+}
+
+size_t git_offmap_num_entries(git_offmap *map)
+{
+	return kh_size(map);
+}
+
+size_t git_offmap_lookup_index(git_offmap *map, const git_off_t key)
+{
+	return kh_get(off, map, key);
+}
+
+int git_offmap_valid_index(git_offmap *map, size_t idx)
+{
+	return idx != kh_end(map);
+}
+
+int git_offmap_exists(git_offmap *map, const git_off_t key)
+{
+	return kh_get(off, map, key) != kh_end(map);
+}
+
+void *git_offmap_value_at(git_offmap *map, size_t idx)
+{
+	return kh_val(map, idx);
+}
+
+void git_offmap_set_value_at(git_offmap *map, size_t idx, void *value)
+{
+	kh_val(map, idx) = value;
+}
+
+void git_offmap_delete_at(git_offmap *map, size_t idx)
+{
+	kh_del(off, map, idx);
+}
+
+int git_offmap_put(git_offmap *map, const git_off_t key, int *err)
+{
+	return kh_put(off, map, key, err);
+}
+
+void git_offmap_insert(git_offmap *map, const git_off_t key, void *value, int *rval)
+{
+	khiter_t idx = kh_put(off, map, key, rval);
+
+	if ((*rval) >= 0) {
+		if ((*rval) == 0)
+			kh_key(map, idx) = key;
+		kh_val(map, idx) = value;
+	}
+}
+
+void git_offmap_delete(git_offmap *map, const git_off_t key)
+{
+	khiter_t idx = git_offmap_lookup_index(map, key);
+	if (git_offmap_valid_index(map, idx))
+		git_offmap_delete_at(map, idx);
+}

vendor/libgit2-sys/libgit2/src/offmap.h

diff --git a/vendor/libgit2-sys/libgit2/src/offmap.h b/vendor/libgit2-sys/libgit2/src/offmap.h
new file mode 100644
index 0000000..0b0896b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/offmap.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2012 the libgit2 contributors
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_offmap_h__
+#define INCLUDE_offmap_h__
+
+#include "common.h"
+
+#include "git2/types.h"
+
+#define kmalloc git__malloc
+#define kcalloc git__calloc
+#define krealloc git__realloc
+#define kreallocarray git__reallocarray
+#define kfree git__free
+#include "khash.h"
+
+__KHASH_TYPE(off, git_off_t, void *)
+typedef khash_t(off) git_offmap;
+
+git_offmap *git_offmap_alloc(void);
+void git_offmap_free(git_offmap *map);
+void git_offmap_clear(git_offmap *map);
+
+size_t git_offmap_num_entries(git_offmap *map);
+
+size_t git_offmap_lookup_index(git_offmap *map, const git_off_t key);
+int git_offmap_valid_index(git_offmap *map, size_t idx);
+
+int git_offmap_exists(git_offmap *map, const git_off_t key);
+
+void *git_offmap_value_at(git_offmap *map, size_t idx);
+void git_offmap_set_value_at(git_offmap *map, size_t idx, void *value);
+void git_offmap_delete_at(git_offmap *map, size_t idx);
+
+int git_offmap_put(git_offmap *map, const git_off_t key, int *err);
+void git_offmap_insert(git_offmap *map, const git_off_t key, void *value, int *rval);
+void git_offmap_delete(git_offmap *map, const git_off_t key);
+
+#define git_offmap_foreach		kh_foreach
+#define git_offmap_foreach_value	kh_foreach_value
+
+#endif

vendor/libgit2-sys/libgit2/src/oid.c

diff --git a/vendor/libgit2-sys/libgit2/src/oid.c b/vendor/libgit2-sys/libgit2/src/oid.c
new file mode 100644
index 0000000..0c63abb
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/oid.c
@@ -0,0 +1,442 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "oid.h"
+
+#include "git2/oid.h"
+#include "repository.h"
+#include "global.h"
+#include <string.h>
+#include <limits.h>
+
+static char to_hex[] = "0123456789abcdef";
+
+static int oid_error_invalid(const char *msg)
+{
+	giterr_set(GITERR_INVALID, "unable to parse OID - %s", msg);
+	return -1;
+}
+
+int git_oid_fromstrn(git_oid *out, const char *str, size_t length)
+{
+	size_t p;
+	int v;
+
+	assert(out && str);
+
+	if (!length)
+		return oid_error_invalid("too short");
+
+	if (length > GIT_OID_HEXSZ)
+		return oid_error_invalid("too long");
+
+	memset(out->id, 0, GIT_OID_RAWSZ);
+
+	for (p = 0; p < length; p++) {
+		v = git__fromhex(str[p]);
+		if (v < 0)
+			return oid_error_invalid("contains invalid characters");
+
+		out->id[p / 2] |= (unsigned char)(v << (p % 2 ? 0 : 4));
+	}
+
+	return 0;
+}
+
+int git_oid_fromstrp(git_oid *out, const char *str)
+{
+	return git_oid_fromstrn(out, str, strlen(str));
+}
+
+int git_oid_fromstr(git_oid *out, const char *str)
+{
+	return git_oid_fromstrn(out, str, GIT_OID_HEXSZ);
+}
+
+GIT_INLINE(char) *fmt_one(char *str, unsigned int val)
+{
+	*str++ = to_hex[val >> 4];
+	*str++ = to_hex[val & 0xf];
+	return str;
+}
+
+void git_oid_nfmt(char *str, size_t n, const git_oid *oid)
+{
+	size_t i, max_i;
+
+	if (!oid) {
+		memset(str, 0, n);
+		return;
+	}
+	if (n > GIT_OID_HEXSZ) {
+		memset(&str[GIT_OID_HEXSZ], 0, n - GIT_OID_HEXSZ);
+		n = GIT_OID_HEXSZ;
+	}
+
+	max_i = n / 2;
+
+	for (i = 0; i < max_i; i++)
+		str = fmt_one(str, oid->id[i]);
+
+	if (n & 1)
+		*str++ = to_hex[oid->id[i] >> 4];
+}
+
+void git_oid_fmt(char *str, const git_oid *oid)
+{
+	git_oid_nfmt(str, GIT_OID_HEXSZ, oid);
+}
+
+void git_oid_pathfmt(char *str, const git_oid *oid)
+{
+	size_t i;
+
+	str = fmt_one(str, oid->id[0]);
+	*str++ = '/';
+	for (i = 1; i < sizeof(oid->id); i++)
+		str = fmt_one(str, oid->id[i]);
+}
+
+char *git_oid_tostr_s(const git_oid *oid)
+{
+	char *str = GIT_GLOBAL->oid_fmt;
+	git_oid_nfmt(str, GIT_OID_HEXSZ + 1, oid);
+	return str;
+}
+
+char *git_oid_allocfmt(const git_oid *oid)
+{
+	char *str = git__malloc(GIT_OID_HEXSZ + 1);
+	if (!str)
+		return NULL;
+	git_oid_nfmt(str, GIT_OID_HEXSZ + 1, oid);
+	return str;
+}
+
+char *git_oid_tostr(char *out, size_t n, const git_oid *oid)
+{
+	if (!out || n == 0)
+		return "";
+
+	if (n > GIT_OID_HEXSZ + 1)
+		n = GIT_OID_HEXSZ + 1;
+
+	git_oid_nfmt(out, n - 1, oid); /* allow room for terminating NUL */
+	out[n - 1] = '\0';
+
+	return out;
+}
+
+int git_oid__parse(
+	git_oid *oid, const char **buffer_out,
+	const char *buffer_end, const char *header)
+{
+	const size_t sha_len = GIT_OID_HEXSZ;
+	const size_t header_len = strlen(header);
+
+	const char *buffer = *buffer_out;
+
+	if (buffer + (header_len + sha_len + 1) > buffer_end)
+		return -1;
+
+	if (memcmp(buffer, header, header_len) != 0)
+		return -1;
+
+	if (buffer[header_len + sha_len] != '\n')
+		return -1;
+
+	if (git_oid_fromstr(oid, buffer + header_len) < 0)
+		return -1;
+
+	*buffer_out = buffer + (header_len + sha_len + 1);
+
+	return 0;
+}
+
+void git_oid__writebuf(git_buf *buf, const char *header, const git_oid *oid)
+{
+	char hex_oid[GIT_OID_HEXSZ];
+
+	git_oid_fmt(hex_oid, oid);
+	git_buf_puts(buf, header);
+	git_buf_put(buf, hex_oid, GIT_OID_HEXSZ);
+	git_buf_putc(buf, '\n');
+}
+
+void git_oid_fromraw(git_oid *out, const unsigned char *raw)
+{
+	memcpy(out->id, raw, sizeof(out->id));
+}
+
+void git_oid_cpy(git_oid *out, const git_oid *src)
+{
+	memcpy(out->id, src->id, sizeof(out->id));
+}
+
+int git_oid_cmp(const git_oid *a, const git_oid *b)
+{
+	return git_oid__cmp(a, b);
+}
+
+int git_oid_equal(const git_oid *a, const git_oid *b)
+{
+	return (git_oid__cmp(a, b) == 0);
+}
+
+int git_oid_ncmp(const git_oid *oid_a, const git_oid *oid_b, size_t len)
+{
+	const unsigned char *a = oid_a->id;
+	const unsigned char *b = oid_b->id;
+
+	if (len > GIT_OID_HEXSZ)
+		len = GIT_OID_HEXSZ;
+
+	while (len > 1) {
+		if (*a != *b)
+			return 1;
+		a++;
+		b++;
+		len -= 2;
+	};
+
+	if (len)
+		if ((*a ^ *b) & 0xf0)
+			return 1;
+
+	return 0;
+}
+
+int git_oid_strcmp(const git_oid *oid_a, const char *str)
+{
+	const unsigned char *a;
+	unsigned char strval;
+	int hexval;
+
+	for (a = oid_a->id; *str && (a - oid_a->id) < GIT_OID_RAWSZ; ++a) {
+		if ((hexval = git__fromhex(*str++)) < 0)
+			return -1;
+		strval = (unsigned char)(hexval << 4);
+		if (*str) {
+			if ((hexval = git__fromhex(*str++)) < 0)
+				return -1;
+			strval |= hexval;
+		}
+		if (*a != strval)
+			return (*a - strval);
+	}
+
+	return 0;
+}
+
+int git_oid_streq(const git_oid *oid_a, const char *str)
+{
+	return git_oid_strcmp(oid_a, str) == 0 ? 0 : -1;
+}
+
+int git_oid_iszero(const git_oid *oid_a)
+{
+	const unsigned char *a = oid_a->id;
+	unsigned int i;
+	for (i = 0; i < GIT_OID_RAWSZ; ++i, ++a)
+		if (*a != 0)
+			return 0;
+	return 1;
+}
+
+typedef short node_index;
+
+typedef union {
+	const char *tail;
+	node_index children[16];
+} trie_node;
+
+struct git_oid_shorten {
+	trie_node *nodes;
+	size_t node_count, size;
+	int min_length, full;
+};
+
+static int resize_trie(git_oid_shorten *self, size_t new_size)
+{
+	self->nodes = git__reallocarray(self->nodes, new_size, sizeof(trie_node));
+	GITERR_CHECK_ALLOC(self->nodes);
+
+	if (new_size > self->size) {
+		memset(&self->nodes[self->size], 0x0, (new_size - self->size) * sizeof(trie_node));
+	}
+
+	self->size = new_size;
+	return 0;
+}
+
+static trie_node *push_leaf(git_oid_shorten *os, node_index idx, int push_at, const char *oid)
+{
+	trie_node *node, *leaf;
+	node_index idx_leaf;
+
+	if (os->node_count >= os->size) {
+		if (resize_trie(os, os->size * 2) < 0)
+			return NULL;
+	}
+
+	idx_leaf = (node_index)os->node_count++;
+
+	if (os->node_count == SHRT_MAX) {
+		os->full = 1;
+        return NULL;
+    }
+
+	node = &os->nodes[idx];
+	node->children[push_at] = -idx_leaf;
+
+	leaf = &os->nodes[idx_leaf];
+	leaf->tail = oid;
+
+	return node;
+}
+
+git_oid_shorten *git_oid_shorten_new(size_t min_length)
+{
+	git_oid_shorten *os;
+
+	assert((size_t)((int)min_length) == min_length);
+
+	os = git__calloc(1, sizeof(git_oid_shorten));
+	if (os == NULL)
+		return NULL;
+
+	if (resize_trie(os, 16) < 0) {
+		git__free(os);
+		return NULL;
+	}
+
+	os->node_count = 1;
+	os->min_length = (int)min_length;
+
+	return os;
+}
+
+void git_oid_shorten_free(git_oid_shorten *os)
+{
+	if (os == NULL)
+		return;
+
+	git__free(os->nodes);
+	git__free(os);
+}
+
+
+/*
+ * What wizardry is this?
+ *
+ * This is just a memory-optimized trie: basically a very fancy
+ * 16-ary tree, which is used to store the prefixes of the OID
+ * strings.
+ *
+ * Read more: http://en.wikipedia.org/wiki/Trie
+ *
+ * Magic that happens in this method:
+ *
+ *	- Each node in the trie is an union, so it can work both as
+ *	a normal node, or as a leaf.
+ *
+ *	- Each normal node points to 16 children (one for each possible
+ *	character in the oid). This is *not* stored in an array of
+ *	pointers, because in a 64-bit arch this would be sucking
+ *	16*sizeof(void*) = 128 bytes of memory per node, which is
+ *	insane. What we do is store Node Indexes, and use these indexes
+ *	to look up each node in the om->index array. These indexes are
+ *	signed shorts, so this limits the amount of unique OIDs that
+ *	fit in the structure to about 20000 (assuming a more or less uniform
+ *	distribution).
+ *
+ *	- All the nodes in om->index array are stored contiguously in
+ *	memory, and each of them is 32 bytes, so we fit 2x nodes per
+ *	cache line. Convenient for speed.
+ *
+ *	- To differentiate the leafs from the normal nodes, we store all
+ *	the indexes towards a leaf as a negative index (indexes to normal
+ *	nodes are positives). When we find that one of the children for
+ *	a node has a negative value, that means it's going to be a leaf.
+ *	This reduces the amount of indexes we have by two, but also reduces
+ *	the size of each node by 1-4 bytes (the amount we would need to
+ *	add a `is_leaf` field): this is good because it allows the nodes
+ *	to fit cleanly in cache lines.
+ *
+ *	- Once we reach an empty children, instead of continuing to insert
+ *	new nodes for each remaining character of the OID, we store a pointer
+ *	to the tail in the leaf; if the leaf is reached again, we turn it
+ *	into a normal node and use the tail to create a new leaf.
+ *
+ *	This is a pretty good balance between performance and memory usage.
+ */
+int git_oid_shorten_add(git_oid_shorten *os, const char *text_oid)
+{
+	int i;
+	bool is_leaf;
+	node_index idx;
+
+	if (os->full) {
+		giterr_set(GITERR_INVALID, "unable to shorten OID - OID set full");
+		return -1;
+	}
+
+	if (text_oid == NULL)
+		return os->min_length;
+
+	idx = 0;
+	is_leaf = false;
+
+	for (i = 0; i < GIT_OID_HEXSZ; ++i) {
+		int c = git__fromhex(text_oid[i]);
+		trie_node *node;
+
+		if (c == -1) {
+			giterr_set(GITERR_INVALID, "unable to shorten OID - invalid hex value");
+			return -1;
+		}
+
+		node = &os->nodes[idx];
+
+		if (is_leaf) {
+			const char *tail;
+
+			tail = node->tail;
+			node->tail = NULL;
+
+			node = push_leaf(os, idx, git__fromhex(tail[0]), &tail[1]);
+			if (node == NULL) {
+				if (os->full)
+					giterr_set(GITERR_INVALID, "unable to shorten OID - OID set full");
+				return -1;
+			}
+		}
+
+		if (node->children[c] == 0) {
+			if (push_leaf(os, idx, c, &text_oid[i + 1]) == NULL) {
+				if (os->full)
+					giterr_set(GITERR_INVALID, "unable to shorten OID - OID set full");
+				return -1;
+			}
+			break;
+		}
+
+		idx = node->children[c];
+		is_leaf = false;
+
+		if (idx < 0) {
+			node->children[c] = idx = -idx;
+			is_leaf = true;
+		}
+	}
+
+	if (++i > os->min_length)
+		os->min_length = i;
+
+	return os->min_length;
+}
+

vendor/libgit2-sys/libgit2/src/oid.h

diff --git a/vendor/libgit2-sys/libgit2/src/oid.h b/vendor/libgit2-sys/libgit2/src/oid.h
new file mode 100644
index 0000000..84231ff
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/oid.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_oid_h__
+#define INCLUDE_oid_h__
+
+#include "common.h"
+
+#include "git2/oid.h"
+
+/**
+ * Format a git_oid into a newly allocated c-string.
+ *
+ * The c-string is owned by the caller and needs to be manually freed.
+ *
+ * @param id the oid structure to format
+ * @return the c-string; NULL if memory is exhausted. Caller must
+ *			deallocate the string with git__free().
+ */
+char *git_oid_allocfmt(const git_oid *id);
+
+GIT_INLINE(int) git_oid__hashcmp(const unsigned char *sha1, const unsigned char *sha2)
+{
+	return memcmp(sha1, sha2, GIT_OID_RAWSZ);
+}
+
+/*
+ * Compare two oid structures.
+ *
+ * @param a first oid structure.
+ * @param b second oid structure.
+ * @return <0, 0, >0 if a < b, a == b, a > b.
+ */
+GIT_INLINE(int) git_oid__cmp(const git_oid *a, const git_oid *b)
+{
+	return git_oid__hashcmp(a->id, b->id);
+}
+
+GIT_INLINE(void) git_oid__cpy_prefix(
+	git_oid *out, const git_oid *id, size_t len)
+{
+	memcpy(&out->id, id->id, (len + 1) / 2);
+
+	if (len & 1)
+		out->id[len / 2] &= 0xF0;
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/oidarray.c

diff --git a/vendor/libgit2-sys/libgit2/src/oidarray.c b/vendor/libgit2-sys/libgit2/src/oidarray.c
new file mode 100644
index 0000000..e70e9dd
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/oidarray.c
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "oidarray.h"
+
+#include "git2/oidarray.h"
+#include "array.h"
+
+void git_oidarray_free(git_oidarray *arr)
+{
+	git__free(arr->ids);
+}
+
+void git_oidarray__from_array(git_oidarray *arr, git_array_oid_t *array)
+{
+	arr->count = array->size;
+	arr->ids = array->ptr;
+}
+
+void git_oidarray__reverse(git_oidarray *arr)
+{
+	size_t i;
+	git_oid tmp;
+
+	for (i = 0; i < arr->count / 2; i++) {
+		git_oid_cpy(&tmp, &arr->ids[i]);
+		git_oid_cpy(&arr->ids[i], &arr->ids[(arr->count-1)-i]);
+		git_oid_cpy(&arr->ids[(arr->count-1)-i], &tmp);
+	}
+}

vendor/libgit2-sys/libgit2/src/oidarray.h

diff --git a/vendor/libgit2-sys/libgit2/src/oidarray.h b/vendor/libgit2-sys/libgit2/src/oidarray.h
new file mode 100644
index 0000000..eed3a10
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/oidarray.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_oidarray_h__
+#define INCLUDE_oidarray_h__
+
+#include "common.h"
+
+#include "git2/oidarray.h"
+#include "array.h"
+
+typedef git_array_t(git_oid) git_array_oid_t;
+
+extern void git_oidarray__reverse(git_oidarray *arr);
+extern void git_oidarray__from_array(git_oidarray *arr, git_array_oid_t *array);
+
+#endif

vendor/libgit2-sys/libgit2/src/oidmap.c

diff --git a/vendor/libgit2-sys/libgit2/src/oidmap.c b/vendor/libgit2-sys/libgit2/src/oidmap.c
new file mode 100644
index 0000000..5f156a1
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/oidmap.c
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "oidmap.h"
+
+GIT_INLINE(khint_t) git_oidmap_hash(const git_oid *oid)
+{
+	khint_t h;
+	memcpy(&h, oid, sizeof(khint_t));
+	return h;
+}
+
+__KHASH_IMPL(oid, static kh_inline, const git_oid *, void *, 1, git_oidmap_hash, git_oid_equal)
+
+git_oidmap *git_oidmap_alloc()
+{
+	return kh_init(oid);
+}
+
+void git_oidmap_free(git_oidmap *map)
+{
+	kh_destroy(oid, map);
+}
+
+void git_oidmap_clear(git_oidmap *map)
+{
+	kh_clear(oid, map);
+}
+
+size_t git_oidmap_size(git_oidmap *map)
+{
+	return kh_size(map);
+}
+
+size_t git_oidmap_lookup_index(git_oidmap *map, const git_oid *key)
+{
+	return kh_get(oid, map, key);
+}
+
+int git_oidmap_valid_index(git_oidmap *map, size_t idx)
+{
+	return idx != kh_end(map);
+}
+
+int git_oidmap_exists(git_oidmap *map, const git_oid *key)
+{
+	return kh_get(oid, map, key) != kh_end(map);
+}
+
+int git_oidmap_has_data(git_oidmap *map, size_t idx)
+{
+	return kh_exist(map, idx);
+}
+
+const git_oid *git_oidmap_key(git_oidmap *map, size_t idx)
+{
+	return kh_key(map, idx);
+}
+
+void git_oidmap_set_key_at(git_oidmap *map, size_t idx, git_oid *key)
+{
+	kh_key(map, idx) = key;
+}
+
+void *git_oidmap_value_at(git_oidmap *map, size_t idx)
+{
+	return kh_val(map, idx);
+}
+
+void git_oidmap_set_value_at(git_oidmap *map, size_t idx, void *value)
+{
+	kh_val(map, idx) = value;
+}
+
+void git_oidmap_delete_at(git_oidmap *map, size_t idx)
+{
+	kh_del(oid, map, idx);
+}
+
+int git_oidmap_put(git_oidmap *map, const git_oid *key, int *err)
+{
+	return kh_put(oid, map, key, err);
+}
+
+void git_oidmap_insert(git_oidmap *map, const git_oid *key, void *value, int *rval)
+{
+	khiter_t idx = kh_put(oid, map, key, rval);
+
+	if ((*rval) >= 0) {
+		if ((*rval) == 0)
+			kh_key(map, idx) = key;
+		kh_val(map, idx) = value;
+	}
+}
+
+void git_oidmap_delete(git_oidmap *map, const git_oid *key)
+{
+	khiter_t idx = git_oidmap_lookup_index(map, key);
+	if (git_oidmap_valid_index(map, idx))
+		git_oidmap_delete_at(map, idx);
+}

vendor/libgit2-sys/libgit2/src/oidmap.h

diff --git a/vendor/libgit2-sys/libgit2/src/oidmap.h b/vendor/libgit2-sys/libgit2/src/oidmap.h
new file mode 100644
index 0000000..49f129e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/oidmap.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_oidmap_h__
+#define INCLUDE_oidmap_h__
+
+#include "common.h"
+
+#include "git2/oid.h"
+
+#define kmalloc git__malloc
+#define kcalloc git__calloc
+#define krealloc git__realloc
+#define kreallocarray git__reallocarray
+#define kfree git__free
+#include "khash.h"
+
+__KHASH_TYPE(oid, const git_oid *, void *)
+typedef khash_t(oid) git_oidmap;
+
+git_oidmap *git_oidmap_alloc(void);
+void git_oidmap_free(git_oidmap *map);
+void git_oidmap_clear(git_oidmap *map);
+
+size_t git_oidmap_size(git_oidmap *map);
+
+size_t git_oidmap_lookup_index(git_oidmap *map, const git_oid *key);
+int git_oidmap_valid_index(git_oidmap *map, size_t idx);
+
+int git_oidmap_exists(git_oidmap *map, const git_oid *key);
+int git_oidmap_has_data(git_oidmap *map, size_t idx);
+
+const git_oid *git_oidmap_key(git_oidmap *map, size_t idx);
+void git_oidmap_set_key_at(git_oidmap *map, size_t idx, git_oid *key);
+void *git_oidmap_value_at(git_oidmap *map, size_t idx);
+void git_oidmap_set_value_at(git_oidmap *map, size_t idx, void *value);
+void git_oidmap_delete_at(git_oidmap *map, size_t idx);
+
+int git_oidmap_put(git_oidmap *map, const git_oid *key, int *err);
+void git_oidmap_insert(git_oidmap *map, const git_oid *key, void *value, int *rval);
+void git_oidmap_delete(git_oidmap *map, const git_oid *key);
+
+#define git_oidmap_foreach_value kh_foreach_value
+
+#define git_oidmap_begin	kh_begin
+#define git_oidmap_end		kh_end
+
+#endif

vendor/libgit2-sys/libgit2/src/pack-objects.c

diff --git a/vendor/libgit2-sys/libgit2/src/pack-objects.c b/vendor/libgit2-sys/libgit2/src/pack-objects.c
new file mode 100644
index 0000000..e924514
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/pack-objects.c
@@ -0,0 +1,1789 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "pack-objects.h"
+
+#include "zstream.h"
+#include "delta.h"
+#include "iterator.h"
+#include "netops.h"
+#include "pack.h"
+#include "thread-utils.h"
+#include "tree.h"
+#include "util.h"
+#include "revwalk.h"
+#include "commit_list.h"
+
+#include "git2/pack.h"
+#include "git2/commit.h"
+#include "git2/tag.h"
+#include "git2/indexer.h"
+#include "git2/config.h"
+
+struct unpacked {
+	git_pobject *object;
+	void *data;
+	struct git_delta_index *index;
+	size_t depth;
+};
+
+struct tree_walk_context {
+	git_packbuilder *pb;
+	git_buf buf;
+};
+
+struct pack_write_context {
+	git_indexer *indexer;
+	git_transfer_progress *stats;
+};
+
+#ifdef GIT_THREADS
+
+#define GIT_PACKBUILDER__MUTEX_OP(pb, mtx, op) do { \
+		int result = git_mutex_##op(&(pb)->mtx); \
+		assert(!result); \
+		GIT_UNUSED(result); \
+	} while (0)
+
+#else
+
+#define GIT_PACKBUILDER__MUTEX_OP(pb,mtx,op) GIT_UNUSED(pb)
+
+#endif /* GIT_THREADS */
+
+#define git_packbuilder__cache_lock(pb) GIT_PACKBUILDER__MUTEX_OP(pb, cache_mutex, lock)
+#define git_packbuilder__cache_unlock(pb) GIT_PACKBUILDER__MUTEX_OP(pb, cache_mutex, unlock)
+#define git_packbuilder__progress_lock(pb) GIT_PACKBUILDER__MUTEX_OP(pb, progress_mutex, lock)
+#define git_packbuilder__progress_unlock(pb) GIT_PACKBUILDER__MUTEX_OP(pb, progress_mutex, unlock)
+
+/* The minimal interval between progress updates (in seconds). */
+#define MIN_PROGRESS_UPDATE_INTERVAL 0.5
+
+/* Size of the buffer to feed to zlib */
+#define COMPRESS_BUFLEN (1024 * 1024)
+
+static unsigned name_hash(const char *name)
+{
+	unsigned c, hash = 0;
+
+	if (!name)
+		return 0;
+
+	/*
+	 * This effectively just creates a sortable number from the
+	 * last sixteen non-whitespace characters. Last characters
+	 * count "most", so things that end in ".c" sort together.
+	 */
+	while ((c = *name++) != 0) {
+		if (git__isspace(c))
+			continue;
+		hash = (hash >> 2) + (c << 24);
+	}
+	return hash;
+}
+
+static int packbuilder_config(git_packbuilder *pb)
+{
+	git_config *config;
+	int ret = 0;
+	int64_t val;
+
+	if ((ret = git_repository_config_snapshot(&config, pb->repo)) < 0)
+		return ret;
+
+#define config_get(KEY,DST,DFLT) do { \
+	ret = git_config_get_int64(&val, config, KEY); \
+	if (!ret) { \
+		if (!git__is_sizet(val)) { \
+			giterr_set(GITERR_CONFIG, \
+				"configuration value '%s' is too large", KEY); \
+			ret = -1; \
+			goto out; \
+		} \
+		(DST) = (size_t)val; \
+	} else if (ret == GIT_ENOTFOUND) { \
+	    (DST) = (DFLT); \
+	    ret = 0; \
+	} else if (ret < 0) goto out; } while (0)
+
+	config_get("pack.deltaCacheSize", pb->max_delta_cache_size,
+		   GIT_PACK_DELTA_CACHE_SIZE);
+	config_get("pack.deltaCacheLimit", pb->cache_max_small_delta_size,
+		   GIT_PACK_DELTA_CACHE_LIMIT);
+	config_get("pack.deltaCacheSize", pb->big_file_threshold,
+		   GIT_PACK_BIG_FILE_THRESHOLD);
+	config_get("pack.windowMemory", pb->window_memory_limit, 0);
+
+#undef config_get
+
+out:
+	git_config_free(config);
+
+	return ret;
+}
+
+int git_packbuilder_new(git_packbuilder **out, git_repository *repo)
+{
+	git_packbuilder *pb;
+
+	*out = NULL;
+
+	pb = git__calloc(1, sizeof(*pb));
+	GITERR_CHECK_ALLOC(pb);
+
+	pb->object_ix = git_oidmap_alloc();
+	if (!pb->object_ix)
+		goto on_error;
+
+	pb->walk_objects = git_oidmap_alloc();
+	if (!pb->walk_objects)
+		goto on_error;
+
+	git_pool_init(&pb->object_pool, sizeof(git_walk_object));
+
+	pb->repo = repo;
+	pb->nr_threads = 1; /* do not spawn any thread by default */
+
+	if (git_hash_ctx_init(&pb->ctx) < 0 ||
+		git_zstream_init(&pb->zstream, GIT_ZSTREAM_DEFLATE) < 0 ||
+		git_repository_odb(&pb->odb, repo) < 0 ||
+		packbuilder_config(pb) < 0)
+		goto on_error;
+
+#ifdef GIT_THREADS
+
+	if (git_mutex_init(&pb->cache_mutex) ||
+		git_mutex_init(&pb->progress_mutex) ||
+		git_cond_init(&pb->progress_cond))
+	{
+		giterr_set(GITERR_OS, "failed to initialize packbuilder mutex");
+		goto on_error;
+	}
+
+#endif
+
+	*out = pb;
+	return 0;
+
+on_error:
+	git_packbuilder_free(pb);
+	return -1;
+}
+
+unsigned int git_packbuilder_set_threads(git_packbuilder *pb, unsigned int n)
+{
+	assert(pb);
+
+#ifdef GIT_THREADS
+	pb->nr_threads = n;
+#else
+	GIT_UNUSED(n);
+	assert(1 == pb->nr_threads);
+#endif
+
+	return pb->nr_threads;
+}
+
+static void rehash(git_packbuilder *pb)
+{
+	git_pobject *po;
+	khiter_t pos;
+	size_t i;
+	int ret;
+
+	git_oidmap_clear(pb->object_ix);
+	for (i = 0, po = pb->object_list; i < pb->nr_objects; i++, po++) {
+		pos = git_oidmap_put(pb->object_ix, &po->id, &ret);
+		git_oidmap_set_value_at(pb->object_ix, pos, po);
+	}
+}
+
+int git_packbuilder_insert(git_packbuilder *pb, const git_oid *oid,
+			   const char *name)
+{
+	git_pobject *po;
+	khiter_t pos;
+	size_t newsize;
+	int ret;
+
+	assert(pb && oid);
+
+	/* If the object already exists in the hash table, then we don't
+	 * have any work to do */
+	if (git_oidmap_exists(pb->object_ix, oid))
+		return 0;
+
+	if (pb->nr_objects >= pb->nr_alloc) {
+		GITERR_CHECK_ALLOC_ADD(&newsize, pb->nr_alloc, 1024);
+		GITERR_CHECK_ALLOC_MULTIPLY(&newsize, newsize, 3 / 2);
+
+		if (!git__is_uint32(newsize)) {
+			giterr_set(GITERR_NOMEMORY, "packfile too large to fit in memory.");
+			return -1;
+		}
+
+		pb->nr_alloc = newsize;
+
+		pb->object_list = git__reallocarray(pb->object_list,
+			pb->nr_alloc, sizeof(*po));
+		GITERR_CHECK_ALLOC(pb->object_list);
+		rehash(pb);
+	}
+
+	po = pb->object_list + pb->nr_objects;
+	memset(po, 0x0, sizeof(*po));
+
+	if ((ret = git_odb_read_header(&po->size, &po->type, pb->odb, oid)) < 0)
+		return ret;
+
+	pb->nr_objects++;
+	git_oid_cpy(&po->id, oid);
+	po->hash = name_hash(name);
+
+	pos = git_oidmap_put(pb->object_ix, &po->id, &ret);
+	if (ret < 0) {
+		giterr_set_oom();
+		return ret;
+	}
+	assert(ret != 0);
+	git_oidmap_set_value_at(pb->object_ix, pos, po);
+
+	pb->done = false;
+
+	if (pb->progress_cb) {
+		double current_time = git__timer();
+		double elapsed = current_time - pb->last_progress_report_time;
+
+		if (elapsed >= MIN_PROGRESS_UPDATE_INTERVAL) {
+			pb->last_progress_report_time = current_time;
+
+			ret = pb->progress_cb(
+				GIT_PACKBUILDER_ADDING_OBJECTS,
+				pb->nr_objects, 0, pb->progress_cb_payload);
+
+			if (ret)
+				return giterr_set_after_callback(ret);
+		}
+	}
+
+	return 0;
+}
+
+static int get_delta(void **out, git_odb *odb, git_pobject *po)
+{
+	git_odb_object *src = NULL, *trg = NULL;
+	size_t delta_size;
+	void *delta_buf;
+	int error;
+
+	*out = NULL;
+
+	if (git_odb_read(&src, odb, &po->delta->id) < 0 ||
+	    git_odb_read(&trg, odb, &po->id) < 0)
+		goto on_error;
+
+	error = git_delta(&delta_buf, &delta_size,
+		git_odb_object_data(src), git_odb_object_size(src),
+		git_odb_object_data(trg), git_odb_object_size(trg),
+		0);
+
+	if (error < 0 && error != GIT_EBUFS)
+		goto on_error;
+
+	if (error == GIT_EBUFS || delta_size != po->delta_size) {
+		giterr_set(GITERR_INVALID, "delta size changed");
+		goto on_error;
+	}
+
+	*out = delta_buf;
+
+	git_odb_object_free(src);
+	git_odb_object_free(trg);
+	return 0;
+
+on_error:
+	git_odb_object_free(src);
+	git_odb_object_free(trg);
+	return -1;
+}
+
+static int write_object(
+	git_packbuilder *pb,
+	git_pobject *po,
+	int (*write_cb)(void *buf, size_t size, void *cb_data),
+	void *cb_data)
+{
+	git_odb_object *obj = NULL;
+	git_otype type;
+	unsigned char hdr[10], *zbuf = NULL;
+	void *data = NULL;
+	size_t hdr_len, zbuf_len = COMPRESS_BUFLEN, data_len;
+	int error;
+
+	/*
+	 * If we have a delta base, let's use the delta to save space.
+	 * Otherwise load the whole object. 'data' ends up pointing to
+	 * whatever data we want to put into the packfile.
+	 */
+	if (po->delta) {
+		if (po->delta_data)
+			data = po->delta_data;
+		else if ((error = get_delta(&data, pb->odb, po)) < 0)
+				goto done;
+
+		data_len = po->delta_size;
+		type = GIT_OBJ_REF_DELTA;
+	} else {
+		if ((error = git_odb_read(&obj, pb->odb, &po->id)) < 0)
+			goto done;
+
+		data = (void *)git_odb_object_data(obj);
+		data_len = git_odb_object_size(obj);
+		type = git_odb_object_type(obj);
+	}
+
+	/* Write header */
+	hdr_len = git_packfile__object_header(hdr, data_len, type);
+
+	if ((error = write_cb(hdr, hdr_len, cb_data)) < 0 ||
+		(error = git_hash_update(&pb->ctx, hdr, hdr_len)) < 0)
+		goto done;
+
+	if (type == GIT_OBJ_REF_DELTA) {
+		if ((error = write_cb(po->delta->id.id, GIT_OID_RAWSZ, cb_data)) < 0 ||
+			(error = git_hash_update(&pb->ctx, po->delta->id.id, GIT_OID_RAWSZ)) < 0)
+			goto done;
+	}
+
+	/* Write data */
+	if (po->z_delta_size) {
+		data_len = po->z_delta_size;
+
+		if ((error = write_cb(data, data_len, cb_data)) < 0 ||
+			(error = git_hash_update(&pb->ctx, data, data_len)) < 0)
+			goto done;
+	} else {
+		zbuf = git__malloc(zbuf_len);
+		GITERR_CHECK_ALLOC(zbuf);
+
+		git_zstream_reset(&pb->zstream);
+		git_zstream_set_input(&pb->zstream, data, data_len);
+
+		while (!git_zstream_done(&pb->zstream)) {
+			if ((error = git_zstream_get_output(zbuf, &zbuf_len, &pb->zstream)) < 0 ||
+				(error = write_cb(zbuf, zbuf_len, cb_data)) < 0 ||
+				(error = git_hash_update(&pb->ctx, zbuf, zbuf_len)) < 0)
+				goto done;
+
+			zbuf_len = COMPRESS_BUFLEN; /* reuse buffer */
+		}
+	}
+
+	/*
+	 * If po->delta is true, data is a delta and it is our
+	 * responsibility to free it (otherwise it's a git_object's
+	 * data). We set po->delta_data to NULL in case we got the
+	 * data from there instead of get_delta(). If we didn't,
+	 * there's no harm.
+	 */
+	if (po->delta) {
+		git__free(data);
+		po->delta_data = NULL;
+	}
+
+	pb->nr_written++;
+
+done:
+	git__free(zbuf);
+	git_odb_object_free(obj);
+	return error;
+}
+
+enum write_one_status {
+	WRITE_ONE_SKIP = -1, /* already written */
+	WRITE_ONE_BREAK = 0, /* writing this will bust the limit; not written */
+	WRITE_ONE_WRITTEN = 1, /* normal */
+	WRITE_ONE_RECURSIVE = 2 /* already scheduled to be written */
+};
+
+static int write_one(
+	enum write_one_status *status,
+	git_packbuilder *pb,
+	git_pobject *po,
+	int (*write_cb)(void *buf, size_t size, void *cb_data),
+	void *cb_data)
+{
+	int error;
+
+	if (po->recursing) {
+		*status = WRITE_ONE_RECURSIVE;
+		return 0;
+	} else if (po->written) {
+		*status = WRITE_ONE_SKIP;
+		return 0;
+	}
+
+	if (po->delta) {
+		po->recursing = 1;
+
+		if ((error = write_one(status, pb, po->delta, write_cb, cb_data)) < 0)
+			return error;
+
+		/* we cannot depend on this one */
+		if (*status == WRITE_ONE_RECURSIVE)
+			po->delta = NULL;
+	}
+
+	*status = WRITE_ONE_WRITTEN;
+	po->written = 1;
+	po->recursing = 0;
+
+	return write_object(pb, po, write_cb, cb_data);
+}
+
+GIT_INLINE(void) add_to_write_order(git_pobject **wo, size_t *endp,
+	git_pobject *po)
+{
+	if (po->filled)
+		return;
+	wo[(*endp)++] = po;
+	po->filled = 1;
+}
+
+static void add_descendants_to_write_order(git_pobject **wo, size_t *endp,
+	git_pobject *po)
+{
+	int add_to_order = 1;
+	while (po) {
+		if (add_to_order) {
+			git_pobject *s;
+			/* add this node... */
+			add_to_write_order(wo, endp, po);
+			/* all its siblings... */
+			for (s = po->delta_sibling; s; s = s->delta_sibling) {
+				add_to_write_order(wo, endp, s);
+			}
+		}
+		/* drop down a level to add left subtree nodes if possible */
+		if (po->delta_child) {
+			add_to_order = 1;
+			po = po->delta_child;
+		} else {
+			add_to_order = 0;
+			/* our sibling might have some children, it is next */
+			if (po->delta_sibling) {
+				po = po->delta_sibling;
+				continue;
+			}
+			/* go back to our parent node */
+			po = po->delta;
+			while (po && !po->delta_sibling) {
+				/* we're on the right side of a subtree, keep
+				 * going up until we can go right again */
+				po = po->delta;
+			}
+			if (!po) {
+				/* done- we hit our original root node */
+				return;
+			}
+			/* pass it off to sibling at this level */
+			po = po->delta_sibling;
+		}
+	};
+}
+
+static void add_family_to_write_order(git_pobject **wo, size_t *endp,
+	git_pobject *po)
+{
+	git_pobject *root;
+
+	for (root = po; root->delta; root = root->delta)
+		; /* nothing */
+	add_descendants_to_write_order(wo, endp, root);
+}
+
+static int cb_tag_foreach(const char *name, git_oid *oid, void *data)
+{
+	git_packbuilder *pb = data;
+	git_pobject *po;
+	khiter_t pos;
+
+	GIT_UNUSED(name);
+
+	pos = git_oidmap_lookup_index(pb->object_ix, oid);
+	if (!git_oidmap_valid_index(pb->object_ix, pos))
+		return 0;
+
+	po = git_oidmap_value_at(pb->object_ix, pos);
+	po->tagged = 1;
+
+	/* TODO: peel objects */
+
+	return 0;
+}
+
+static git_pobject **compute_write_order(git_packbuilder *pb)
+{
+	size_t i, wo_end, last_untagged;
+	git_pobject **wo;
+
+	if ((wo = git__mallocarray(pb->nr_objects, sizeof(*wo))) == NULL)
+		return NULL;
+
+	for (i = 0; i < pb->nr_objects; i++) {
+		git_pobject *po = pb->object_list + i;
+		po->tagged = 0;
+		po->filled = 0;
+		po->delta_child = NULL;
+		po->delta_sibling = NULL;
+	}
+
+	/*
+	 * Fully connect delta_child/delta_sibling network.
+	 * Make sure delta_sibling is sorted in the original
+	 * recency order.
+	 */
+	for (i = pb->nr_objects; i > 0;) {
+		git_pobject *po = &pb->object_list[--i];
+		if (!po->delta)
+			continue;
+		/* Mark me as the first child */
+		po->delta_sibling = po->delta->delta_child;
+		po->delta->delta_child = po;
+	}
+
+	/*
+	 * Mark objects that are at the tip of tags.
+	 */
+	if (git_tag_foreach(pb->repo, &cb_tag_foreach, pb) < 0) {
+		git__free(wo);
+		return NULL;
+	}
+
+	/*
+	 * Give the objects in the original recency order until
+	 * we see a tagged tip.
+	 */
+	for (i = wo_end = 0; i < pb->nr_objects; i++) {
+		git_pobject *po = pb->object_list + i;
+		if (po->tagged)
+			break;
+		add_to_write_order(wo, &wo_end, po);
+	}
+	last_untagged = i;
+
+	/*
+	 * Then fill all the tagged tips.
+	 */
+	for (; i < pb->nr_objects; i++) {
+		git_pobject *po = pb->object_list + i;
+		if (po->tagged)
+			add_to_write_order(wo, &wo_end, po);
+	}
+
+	/*
+	 * And then all remaining commits and tags.
+	 */
+	for (i = last_untagged; i < pb->nr_objects; i++) {
+		git_pobject *po = pb->object_list + i;
+		if (po->type != GIT_OBJ_COMMIT &&
+		    po->type != GIT_OBJ_TAG)
+			continue;
+		add_to_write_order(wo, &wo_end, po);
+	}
+
+	/*
+	 * And then all the trees.
+	 */
+	for (i = last_untagged; i < pb->nr_objects; i++) {
+		git_pobject *po = pb->object_list + i;
+		if (po->type != GIT_OBJ_TREE)
+			continue;
+		add_to_write_order(wo, &wo_end, po);
+	}
+
+	/*
+	 * Finally all the rest in really tight order
+	 */
+	for (i = last_untagged; i < pb->nr_objects; i++) {
+		git_pobject *po = pb->object_list + i;
+		if (!po->filled)
+			add_family_to_write_order(wo, &wo_end, po);
+	}
+
+	if (wo_end != pb->nr_objects) {
+		git__free(wo);
+		giterr_set(GITERR_INVALID, "invalid write order");
+		return NULL;
+	}
+
+	return wo;
+}
+
+static int write_pack(git_packbuilder *pb,
+	int (*write_cb)(void *buf, size_t size, void *cb_data),
+	void *cb_data)
+{
+	git_pobject **write_order;
+	git_pobject *po;
+	enum write_one_status status;
+	struct git_pack_header ph;
+	git_oid entry_oid;
+	size_t i = 0;
+	int error = 0;
+
+	write_order = compute_write_order(pb);
+	if (write_order == NULL)
+		return -1;
+
+	if (!git__is_uint32(pb->nr_objects)) {
+		giterr_set(GITERR_INVALID, "too many objects");
+		return -1;
+	}
+
+	/* Write pack header */
+	ph.hdr_signature = htonl(PACK_SIGNATURE);
+	ph.hdr_version = htonl(PACK_VERSION);
+	ph.hdr_entries = htonl(pb->nr_objects);
+
+	if ((error = write_cb(&ph, sizeof(ph), cb_data)) < 0 ||
+		(error = git_hash_update(&pb->ctx, &ph, sizeof(ph))) < 0)
+		goto done;
+
+	pb->nr_remaining = pb->nr_objects;
+	do {
+		pb->nr_written = 0;
+		for ( ; i < pb->nr_objects; ++i) {
+			po = write_order[i];
+
+			if ((error = write_one(&status, pb, po, write_cb, cb_data)) < 0)
+				goto done;
+		}
+
+		pb->nr_remaining -= pb->nr_written;
+	} while (pb->nr_remaining && i < pb->nr_objects);
+
+	if ((error = git_hash_final(&entry_oid, &pb->ctx)) < 0)
+		goto done;
+
+	error = write_cb(entry_oid.id, GIT_OID_RAWSZ, cb_data);
+
+done:
+	/* if callback cancelled writing, we must still free delta_data */
+	for ( ; i < pb->nr_objects; ++i) {
+		po = write_order[i];
+		if (po->delta_data) {
+			git__free(po->delta_data);
+			po->delta_data = NULL;
+		}
+	}
+
+	git__free(write_order);
+	return error;
+}
+
+static int write_pack_buf(void *buf, size_t size, void *data)
+{
+	git_buf *b = (git_buf *)data;
+	return git_buf_put(b, buf, size);
+}
+
+static int type_size_sort(const void *_a, const void *_b)
+{
+	const git_pobject *a = (git_pobject *)_a;
+	const git_pobject *b = (git_pobject *)_b;
+
+	if (a->type > b->type)
+		return -1;
+	if (a->type < b->type)
+		return 1;
+	if (a->hash > b->hash)
+		return -1;
+	if (a->hash < b->hash)
+		return 1;
+	/*
+	 * TODO
+	 *
+	if (a->preferred_base > b->preferred_base)
+		return -1;
+	if (a->preferred_base < b->preferred_base)
+		return 1;
+	*/
+	if (a->size > b->size)
+		return -1;
+	if (a->size < b->size)
+		return 1;
+	return a < b ? -1 : (a > b); /* newest first */
+}
+
+static int delta_cacheable(
+	git_packbuilder *pb,
+	size_t src_size,
+	size_t trg_size,
+	size_t delta_size)
+{
+	size_t new_size;
+
+	if (git__add_sizet_overflow(&new_size, pb->delta_cache_size, delta_size))
+		return 0;
+
+	if (pb->max_delta_cache_size && new_size > pb->max_delta_cache_size)
+		return 0;
+
+	if (delta_size < pb->cache_max_small_delta_size)
+		return 1;
+
+	/* cache delta, if objects are large enough compared to delta size */
+	if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
+		return 1;
+
+	return 0;
+}
+
+static int try_delta(git_packbuilder *pb, struct unpacked *trg,
+		     struct unpacked *src, size_t max_depth,
+			 size_t *mem_usage, int *ret)
+{
+	git_pobject *trg_object = trg->object;
+	git_pobject *src_object = src->object;
+	git_odb_object *obj;
+	size_t trg_size, src_size, delta_size, sizediff, max_size, sz;
+	size_t ref_depth;
+	void *delta_buf;
+
+	/* Don't bother doing diffs between different types */
+	if (trg_object->type != src_object->type) {
+		*ret = -1;
+		return 0;
+	}
+
+	*ret = 0;
+
+	/* TODO: support reuse-delta */
+
+	/* Let's not bust the allowed depth. */
+	if (src->depth >= max_depth)
+		return 0;
+
+	/* Now some size filtering heuristics. */
+	trg_size = trg_object->size;
+	if (!trg_object->delta) {
+		max_size = trg_size/2 - 20;
+		ref_depth = 1;
+	} else {
+		max_size = trg_object->delta_size;
+		ref_depth = trg->depth;
+	}
+
+	max_size = (uint64_t)max_size * (max_depth - src->depth) /
+					(max_depth - ref_depth + 1);
+	if (max_size == 0)
+		return 0;
+
+	src_size = src_object->size;
+	sizediff = src_size < trg_size ? trg_size - src_size : 0;
+	if (sizediff >= max_size)
+		return 0;
+	if (trg_size < src_size / 32)
+		return 0;
+
+	/* Load data if not already done */
+	if (!trg->data) {
+		if (git_odb_read(&obj, pb->odb, &trg_object->id) < 0)
+			return -1;
+
+		sz = git_odb_object_size(obj);
+		trg->data = git__malloc(sz);
+		GITERR_CHECK_ALLOC(trg->data);
+		memcpy(trg->data, git_odb_object_data(obj), sz);
+
+		git_odb_object_free(obj);
+
+		if (sz != trg_size) {
+			giterr_set(GITERR_INVALID,
+				   "inconsistent target object length");
+			return -1;
+		}
+
+		*mem_usage += sz;
+	}
+	if (!src->data) {
+		size_t obj_sz;
+
+		if (git_odb_read(&obj, pb->odb, &src_object->id) < 0 ||
+			!git__is_ulong(obj_sz = git_odb_object_size(obj)))
+			return -1;
+
+		sz = obj_sz;
+		src->data = git__malloc(sz);
+		GITERR_CHECK_ALLOC(src->data);
+		memcpy(src->data, git_odb_object_data(obj), sz);
+
+		git_odb_object_free(obj);
+
+		if (sz != src_size) {
+			giterr_set(GITERR_INVALID,
+				   "inconsistent source object length");
+			return -1;
+		}
+
+		*mem_usage += sz;
+	}
+	if (!src->index) {
+		if (git_delta_index_init(&src->index, src->data, src_size) < 0)
+			return 0; /* suboptimal pack - out of memory */
+
+		*mem_usage += git_delta_index_size(src->index);
+	}
+
+	if (git_delta_create_from_index(&delta_buf, &delta_size, src->index, trg->data, trg_size,
+		max_size) < 0)
+		return 0;
+
+	if (trg_object->delta) {
+		/* Prefer only shallower same-sized deltas. */
+		if (delta_size == trg_object->delta_size &&
+		    src->depth + 1 >= trg->depth) {
+			git__free(delta_buf);
+			return 0;
+		}
+	}
+
+	git_packbuilder__cache_lock(pb);
+	if (trg_object->delta_data) {
+		git__free(trg_object->delta_data);
+		assert(pb->delta_cache_size >= trg_object->delta_size);
+		pb->delta_cache_size -= trg_object->delta_size;
+		trg_object->delta_data = NULL;
+	}
+	if (delta_cacheable(pb, src_size, trg_size, delta_size)) {
+		bool overflow = git__add_sizet_overflow(
+			&pb->delta_cache_size, pb->delta_cache_size, delta_size);
+
+		git_packbuilder__cache_unlock(pb);
+
+		if (overflow) {
+			git__free(delta_buf);
+			return -1;
+		}
+
+		trg_object->delta_data = git__realloc(delta_buf, delta_size);
+		GITERR_CHECK_ALLOC(trg_object->delta_data);
+	} else {
+		/* create delta when writing the pack */
+		git_packbuilder__cache_unlock(pb);
+		git__free(delta_buf);
+	}
+
+	trg_object->delta = src_object;
+	trg_object->delta_size = delta_size;
+	trg->depth = src->depth + 1;
+
+	*ret = 1;
+	return 0;
+}
+
+static size_t check_delta_limit(git_pobject *me, size_t n)
+{
+	git_pobject *child = me->delta_child;
+	size_t m = n;
+
+	while (child) {
+		size_t c = check_delta_limit(child, n + 1);
+		if (m < c)
+			m = c;
+		child = child->delta_sibling;
+	}
+	return m;
+}
+
+static size_t free_unpacked(struct unpacked *n)
+{
+	size_t freed_mem = 0;
+
+	if (n->index) {
+		freed_mem += git_delta_index_size(n->index);
+		git_delta_index_free(n->index);
+	}
+	n->index = NULL;
+
+	if (n->data) {
+		freed_mem += n->object->size;
+		git__free(n->data);
+		n->data = NULL;
+	}
+	n->object = NULL;
+	n->depth = 0;
+	return freed_mem;
+}
+
+static int report_delta_progress(
+	git_packbuilder *pb, uint32_t count, bool force)
+{
+	int ret;
+
+	if (pb->progress_cb) {
+		double current_time = git__timer();
+		double elapsed = current_time - pb->last_progress_report_time;
+
+		if (force || elapsed >= MIN_PROGRESS_UPDATE_INTERVAL) {
+			pb->last_progress_report_time = current_time;
+
+			ret = pb->progress_cb(
+				GIT_PACKBUILDER_DELTAFICATION,
+				count, pb->nr_objects, pb->progress_cb_payload);
+
+			if (ret)
+				return giterr_set_after_callback(ret);
+		}
+	}
+
+	return 0;
+}
+
+static int find_deltas(git_packbuilder *pb, git_pobject **list,
+	size_t *list_size, size_t window, size_t depth)
+{
+	git_pobject *po;
+	git_buf zbuf = GIT_BUF_INIT;
+	struct unpacked *array;
+	size_t idx = 0, count = 0;
+	size_t mem_usage = 0;
+	size_t i;
+	int error = -1;
+
+	array = git__calloc(window, sizeof(struct unpacked));
+	GITERR_CHECK_ALLOC(array);
+
+	for (;;) {
+		struct unpacked *n = array + idx;
+		size_t max_depth, j, best_base = SIZE_MAX;
+
+		git_packbuilder__progress_lock(pb);
+		if (!*list_size) {
+			git_packbuilder__progress_unlock(pb);
+			break;
+		}
+
+		pb->nr_deltified += 1;
+		report_delta_progress(pb, pb->nr_deltified, false);
+
+		po = *list++;
+		(*list_size)--;
+		git_packbuilder__progress_unlock(pb);
+
+		mem_usage -= free_unpacked(n);
+		n->object = po;
+
+		while (pb->window_memory_limit &&
+		       mem_usage > pb->window_memory_limit &&
+		       count > 1) {
+			size_t tail = (idx + window - count) % window;
+			mem_usage -= free_unpacked(array + tail);
+			count--;
+		}
+
+		/*
+		 * If the current object is at pack edge, take the depth the
+		 * objects that depend on the current object into account
+		 * otherwise they would become too deep.
+		 */
+		max_depth = depth;
+		if (po->delta_child) {
+			size_t delta_limit = check_delta_limit(po, 0);
+
+			if (delta_limit > max_depth)
+				goto next;
+
+			max_depth -= delta_limit;
+		}
+
+		j = window;
+		while (--j > 0) {
+			int ret;
+			size_t other_idx = idx + j;
+			struct unpacked *m;
+
+			if (other_idx >= window)
+				other_idx -= window;
+
+			m = array + other_idx;
+			if (!m->object)
+				break;
+
+			if (try_delta(pb, n, m, max_depth, &mem_usage, &ret) < 0)
+				goto on_error;
+			if (ret < 0)
+				break;
+			else if (ret > 0)
+				best_base = other_idx;
+		}
+
+		/*
+		 * If we decided to cache the delta data, then it is best
+		 * to compress it right away.  First because we have to do
+		 * it anyway, and doing it here while we're threaded will
+		 * save a lot of time in the non threaded write phase,
+		 * as well as allow for caching more deltas within
+		 * the same cache size limit.
+		 * ...
+		 * But only if not writing to stdout, since in that case
+		 * the network is most likely throttling writes anyway,
+		 * and therefore it is best to go to the write phase ASAP
+		 * instead, as we can afford spending more time compressing
+		 * between writes at that moment.
+		 */
+		if (po->delta_data) {
+			if (git_zstream_deflatebuf(&zbuf, po->delta_data, po->delta_size) < 0)
+				goto on_error;
+
+			git__free(po->delta_data);
+			po->delta_data = git__malloc(zbuf.size);
+			GITERR_CHECK_ALLOC(po->delta_data);
+
+			memcpy(po->delta_data, zbuf.ptr, zbuf.size);
+			po->z_delta_size = zbuf.size;
+			git_buf_clear(&zbuf);
+
+			git_packbuilder__cache_lock(pb);
+			pb->delta_cache_size -= po->delta_size;
+			pb->delta_cache_size += po->z_delta_size;
+			git_packbuilder__cache_unlock(pb);
+		}
+
+		/*
+		 * If we made n a delta, and if n is already at max
+		 * depth, leaving it in the window is pointless.  we
+		 * should evict it first.
+		 */
+		if (po->delta && max_depth <= n->depth)
+			continue;
+
+		/*
+		 * Move the best delta base up in the window, after the
+		 * currently deltified object, to keep it longer.  It will
+		 * be the first base object to be attempted next.
+		 */
+		if (po->delta) {
+			struct unpacked swap = array[best_base];
+			size_t dist = (window + idx - best_base) % window;
+			size_t dst = best_base;
+			while (dist--) {
+				size_t src = (dst + 1) % window;
+				array[dst] = array[src];
+				dst = src;
+			}
+			array[dst] = swap;
+		}
+
+		next:
+		idx++;
+		if (count + 1 < window)
+			count++;
+		if (idx >= window)
+			idx = 0;
+	}
+	error = 0;
+
+on_error:
+	for (i = 0; i < window; ++i) {
+		git__free(array[i].index);
+		git__free(array[i].data);
+	}
+	git__free(array);
+	git_buf_free(&zbuf);
+
+	return error;
+}
+
+#ifdef GIT_THREADS
+
+struct thread_params {
+	git_thread thread;
+	git_packbuilder *pb;
+
+	git_pobject **list;
+
+	git_cond cond;
+	git_mutex mutex;
+
+	size_t list_size;
+	size_t remaining;
+
+	size_t window;
+	size_t depth;
+	size_t working;
+	size_t data_ready;
+};
+
+static void *threaded_find_deltas(void *arg)
+{
+	struct thread_params *me = arg;
+
+	while (me->remaining) {
+		if (find_deltas(me->pb, me->list, &me->remaining,
+				me->window, me->depth) < 0) {
+			; /* TODO */
+		}
+
+		git_packbuilder__progress_lock(me->pb);
+		me->working = 0;
+		git_cond_signal(&me->pb->progress_cond);
+		git_packbuilder__progress_unlock(me->pb);
+
+		if (git_mutex_lock(&me->mutex)) {
+			giterr_set(GITERR_THREAD, "unable to lock packfile condition mutex");
+			return NULL;
+		}
+
+		while (!me->data_ready)
+			git_cond_wait(&me->cond, &me->mutex);
+
+		/*
+		 * We must not set ->data_ready before we wait on the
+		 * condition because the main thread may have set it to 1
+		 * before we get here. In order to be sure that new
+		 * work is available if we see 1 in ->data_ready, it
+		 * was initialized to 0 before this thread was spawned
+		 * and we reset it to 0 right away.
+		 */
+		me->data_ready = 0;
+		git_mutex_unlock(&me->mutex);
+	}
+	/* leave ->working 1 so that this doesn't get more work assigned */
+	return NULL;
+}
+
+static int ll_find_deltas(git_packbuilder *pb, git_pobject **list,
+			  size_t list_size, size_t window, size_t depth)
+{
+	struct thread_params *p;
+	size_t i;
+	int ret, active_threads = 0;
+
+	if (!pb->nr_threads)
+		pb->nr_threads = git_online_cpus();
+
+	if (pb->nr_threads <= 1) {
+		find_deltas(pb, list, &list_size, window, depth);
+		return 0;
+	}
+
+	p = git__mallocarray(pb->nr_threads, sizeof(*p));
+	GITERR_CHECK_ALLOC(p);
+
+	/* Partition the work among the threads */
+	for (i = 0; i < pb->nr_threads; ++i) {
+		size_t sub_size = list_size / (pb->nr_threads - i);
+
+		/* don't use too small segments or no deltas will be found */
+		if (sub_size < 2*window && i+1 < pb->nr_threads)
+			sub_size = 0;
+
+		p[i].pb = pb;
+		p[i].window = window;
+		p[i].depth = depth;
+		p[i].working = 1;
+		p[i].data_ready = 0;
+
+		/* try to split chunks on "path" boundaries */
+		while (sub_size && sub_size < list_size &&
+		       list[sub_size]->hash &&
+		       list[sub_size]->hash == list[sub_size-1]->hash)
+			sub_size++;
+
+		p[i].list = list;
+		p[i].list_size = sub_size;
+		p[i].remaining = sub_size;
+
+		list += sub_size;
+		list_size -= sub_size;
+	}
+
+	/* Start work threads */
+	for (i = 0; i < pb->nr_threads; ++i) {
+		if (!p[i].list_size)
+			continue;
+
+		git_mutex_init(&p[i].mutex);
+		git_cond_init(&p[i].cond);
+
+		ret = git_thread_create(&p[i].thread,
+					threaded_find_deltas, &p[i]);
+		if (ret) {
+			giterr_set(GITERR_THREAD, "unable to create thread");
+			return -1;
+		}
+		active_threads++;
+	}
+
+	/*
+	 * Now let's wait for work completion.  Each time a thread is done
+	 * with its work, we steal half of the remaining work from the
+	 * thread with the largest number of unprocessed objects and give
+	 * it to that newly idle thread.  This ensure good load balancing
+	 * until the remaining object list segments are simply too short
+	 * to be worth splitting anymore.
+	 */
+	while (active_threads) {
+		struct thread_params *target = NULL;
+		struct thread_params *victim = NULL;
+		size_t sub_size = 0;
+
+		/* Start by locating a thread that has transitioned its
+		 * 'working' flag from 1 -> 0. This indicates that it is
+		 * ready to receive more work using our work-stealing
+		 * algorithm. */
+		git_packbuilder__progress_lock(pb);
+		for (;;) {
+			for (i = 0; !target && i < pb->nr_threads; i++)
+				if (!p[i].working)
+					target = &p[i];
+			if (target)
+				break;
+			git_cond_wait(&pb->progress_cond, &pb->progress_mutex);
+		}
+
+		/* At this point we hold the progress lock and have located
+		 * a thread to receive more work. We still need to locate a
+		 * thread from which to steal work (the victim). */
+		for (i = 0; i < pb->nr_threads; i++)
+			if (p[i].remaining > 2*window &&
+			    (!victim || victim->remaining < p[i].remaining))
+				victim = &p[i];
+
+		if (victim) {
+			sub_size = victim->remaining / 2;
+			list = victim->list + victim->list_size - sub_size;
+			while (sub_size && list[0]->hash &&
+			       list[0]->hash == list[-1]->hash) {
+				list++;
+				sub_size--;
+			}
+			if (!sub_size) {
+				/*
+				 * It is possible for some "paths" to have
+				 * so many objects that no hash boundary
+				 * might be found.  Let's just steal the
+				 * exact half in that case.
+				 */
+				sub_size = victim->remaining / 2;
+				list -= sub_size;
+			}
+			target->list = list;
+			victim->list_size -= sub_size;
+			victim->remaining -= sub_size;
+		}
+		target->list_size = sub_size;
+		target->remaining = sub_size;
+		target->working = 1;
+		git_packbuilder__progress_unlock(pb);
+
+		if (git_mutex_lock(&target->mutex)) {
+			giterr_set(GITERR_THREAD, "unable to lock packfile condition mutex");
+			git__free(p);
+			return -1;
+		}
+
+		target->data_ready = 1;
+		git_cond_signal(&target->cond);
+		git_mutex_unlock(&target->mutex);
+
+		if (!sub_size) {
+			git_thread_join(&target->thread, NULL);
+			git_cond_free(&target->cond);
+			git_mutex_free(&target->mutex);
+			active_threads--;
+		}
+	}
+
+	git__free(p);
+	return 0;
+}
+
+#else
+#define ll_find_deltas(pb, l, ls, w, d) find_deltas(pb, l, &ls, w, d)
+#endif
+
+static int prepare_pack(git_packbuilder *pb)
+{
+	git_pobject **delta_list;
+	size_t i, n = 0;
+
+	if (pb->nr_objects == 0 || pb->done)
+		return 0; /* nothing to do */
+
+	/*
+	 * Although we do not report progress during deltafication, we
+	 * at least report that we are in the deltafication stage
+	 */
+	if (pb->progress_cb)
+			pb->progress_cb(GIT_PACKBUILDER_DELTAFICATION, 0, pb->nr_objects, pb->progress_cb_payload);
+
+	delta_list = git__mallocarray(pb->nr_objects, sizeof(*delta_list));
+	GITERR_CHECK_ALLOC(delta_list);
+
+	for (i = 0; i < pb->nr_objects; ++i) {
+		git_pobject *po = pb->object_list + i;
+
+		/* Make sure the item is within our size limits */
+		if (po->size < 50 || po->size > pb->big_file_threshold)
+			continue;
+
+		delta_list[n++] = po;
+	}
+
+	if (n > 1) {
+		git__tsort((void **)delta_list, n, type_size_sort);
+		if (ll_find_deltas(pb, delta_list, n,
+				   GIT_PACK_WINDOW + 1,
+				   GIT_PACK_DEPTH) < 0) {
+			git__free(delta_list);
+			return -1;
+		}
+	}
+
+	report_delta_progress(pb, pb->nr_objects, true);
+
+	pb->done = true;
+	git__free(delta_list);
+	return 0;
+}
+
+#define PREPARE_PACK if (prepare_pack(pb) < 0) { return -1; }
+
+int git_packbuilder_foreach(git_packbuilder *pb, int (*cb)(void *buf, size_t size, void *payload), void *payload)
+{
+	PREPARE_PACK;
+	return write_pack(pb, cb, payload);
+}
+
+int git_packbuilder_write_buf(git_buf *buf, git_packbuilder *pb)
+{
+	PREPARE_PACK;
+	git_buf_sanitize(buf);
+	return write_pack(pb, &write_pack_buf, buf);
+}
+
+static int write_cb(void *buf, size_t len, void *payload)
+{
+	struct pack_write_context *ctx = payload;
+	return git_indexer_append(ctx->indexer, buf, len, ctx->stats);
+}
+
+int git_packbuilder_write(
+	git_packbuilder *pb,
+	const char *path,
+	unsigned int mode,
+	git_transfer_progress_cb progress_cb,
+	void *progress_cb_payload)
+{
+	git_indexer *indexer;
+	git_transfer_progress stats;
+	struct pack_write_context ctx;
+	int t;
+
+	PREPARE_PACK;
+
+	if (git_indexer_new(
+		&indexer, path, mode, pb->odb, progress_cb, progress_cb_payload) < 0)
+		return -1;
+
+	if (!git_repository__cvar(&t, pb->repo, GIT_CVAR_FSYNCOBJECTFILES) && t)
+		git_indexer__set_fsync(indexer, 1);
+
+	ctx.indexer = indexer;
+	ctx.stats = &stats;
+
+	if (git_packbuilder_foreach(pb, write_cb, &ctx) < 0 ||
+		git_indexer_commit(indexer, &stats) < 0) {
+		git_indexer_free(indexer);
+		return -1;
+	}
+
+	git_oid_cpy(&pb->pack_oid, git_indexer_hash(indexer));
+
+	git_indexer_free(indexer);
+	return 0;
+}
+
+#undef PREPARE_PACK
+
+const git_oid *git_packbuilder_hash(git_packbuilder *pb)
+{
+	return &pb->pack_oid;
+}
+
+
+static int cb_tree_walk(
+	const char *root, const git_tree_entry *entry, void *payload)
+{
+	int error;
+	struct tree_walk_context *ctx = payload;
+
+	/* A commit inside a tree represents a submodule commit and should be skipped. */
+	if (git_tree_entry_type(entry) == GIT_OBJ_COMMIT)
+		return 0;
+
+	if (!(error = git_buf_sets(&ctx->buf, root)) &&
+		!(error = git_buf_puts(&ctx->buf, git_tree_entry_name(entry))))
+		error = git_packbuilder_insert(
+			ctx->pb, git_tree_entry_id(entry), git_buf_cstr(&ctx->buf));
+
+	return error;
+}
+
+int git_packbuilder_insert_commit(git_packbuilder *pb, const git_oid *oid)
+{
+	git_commit *commit;
+
+	if (git_commit_lookup(&commit, pb->repo, oid) < 0 ||
+		git_packbuilder_insert(pb, oid, NULL) < 0)
+		return -1;
+
+	if (git_packbuilder_insert_tree(pb, git_commit_tree_id(commit)) < 0)
+		return -1;
+
+	git_commit_free(commit);
+	return 0;
+}
+
+int git_packbuilder_insert_tree(git_packbuilder *pb, const git_oid *oid)
+{
+	int error;
+	git_tree *tree = NULL;
+	struct tree_walk_context context = { pb, GIT_BUF_INIT };
+
+	if (!(error = git_tree_lookup(&tree, pb->repo, oid)) &&
+	    !(error = git_packbuilder_insert(pb, oid, NULL)))
+		error = git_tree_walk(tree, GIT_TREEWALK_PRE, cb_tree_walk, &context);
+
+	git_tree_free(tree);
+	git_buf_free(&context.buf);
+	return error;
+}
+
+int git_packbuilder_insert_recur(git_packbuilder *pb, const git_oid *id, const char *name)
+{
+	git_object *obj;
+	int error;
+
+	assert(pb && id);
+
+	if ((error = git_object_lookup(&obj, pb->repo, id, GIT_OBJ_ANY)) < 0)
+		return error;
+
+	switch (git_object_type(obj)) {
+	case GIT_OBJ_BLOB:
+		error = git_packbuilder_insert(pb, id, name);
+		break;
+	case GIT_OBJ_TREE:
+		error = git_packbuilder_insert_tree(pb, id);
+		break;
+	case GIT_OBJ_COMMIT:
+		error = git_packbuilder_insert_commit(pb, id);
+		break;
+	case GIT_OBJ_TAG:
+		if ((error = git_packbuilder_insert(pb, id, name)) < 0)
+			goto cleanup;
+		error = git_packbuilder_insert_recur(pb, git_tag_target_id((git_tag *) obj), NULL);
+		break;
+
+	default:
+		giterr_set(GITERR_INVALID, "unknown object type");
+		error = -1;
+	}
+
+cleanup:
+	git_object_free(obj);
+	return error;
+}
+
+size_t git_packbuilder_object_count(git_packbuilder *pb)
+{
+	return pb->nr_objects;
+}
+
+size_t git_packbuilder_written(git_packbuilder *pb)
+{
+	return pb->nr_written;
+}
+
+int lookup_walk_object(git_walk_object **out, git_packbuilder *pb, const git_oid *id)
+{
+	git_walk_object *obj;
+
+	obj = git_pool_mallocz(&pb->object_pool, 1);
+	if (!obj) {
+		giterr_set_oom();
+		return -1;
+	}
+
+	git_oid_cpy(&obj->id, id);
+
+	*out = obj;
+	return 0;
+}
+
+static int retrieve_object(git_walk_object **out, git_packbuilder *pb, const git_oid *id)
+{
+	int error;
+	khiter_t pos;
+	git_walk_object *obj;
+
+	pos = git_oidmap_lookup_index(pb->walk_objects, id);
+	if (git_oidmap_valid_index(pb->walk_objects, pos)) {
+		obj = git_oidmap_value_at(pb->walk_objects, pos);
+	} else {
+		if ((error = lookup_walk_object(&obj, pb, id)) < 0)
+			return error;
+
+		git_oidmap_insert(pb->walk_objects, &obj->id, obj, &error);
+	}
+
+	*out = obj;
+	return 0;
+}
+
+static int mark_blob_uninteresting(git_packbuilder *pb, const git_oid *id)
+{
+	int error;
+	git_walk_object *obj;
+
+	if ((error = retrieve_object(&obj, pb, id)) < 0)
+		return error;
+
+	obj->uninteresting = 1;
+
+	return 0;
+}
+
+static int mark_tree_uninteresting(git_packbuilder *pb, const git_oid *id)
+{
+	git_walk_object *obj;
+	git_tree *tree;
+	int error;
+	size_t i;
+
+	if ((error = retrieve_object(&obj, pb, id)) < 0)
+		return error;
+
+	if (obj->uninteresting)
+		return 0;
+
+	obj->uninteresting = 1;
+
+	if ((error = git_tree_lookup(&tree, pb->repo, id)) < 0)
+		return error;
+
+	for (i = 0; i < git_tree_entrycount(tree); i++) {
+		const git_tree_entry *entry = git_tree_entry_byindex(tree, i);
+		const git_oid *entry_id = git_tree_entry_id(entry);
+		switch (git_tree_entry_type(entry)) {
+		case GIT_OBJ_TREE:
+			if ((error = mark_tree_uninteresting(pb, entry_id)) < 0)
+				goto cleanup;
+			break;
+		case GIT_OBJ_BLOB:
+			if ((error = mark_blob_uninteresting(pb, entry_id)) < 0)
+				goto cleanup;
+			break;
+		default:
+			/* it's a submodule or something unknown, we don't want it */
+			;
+		}
+	}
+
+cleanup:
+	git_tree_free(tree);
+	return error;
+}
+
+/*
+ * Mark the edges of the graph uninteresting. Since we start from a
+ * git_revwalk, the commits are already uninteresting, but we need to
+ * mark the trees and blobs.
+ */
+static int mark_edges_uninteresting(git_packbuilder *pb, git_commit_list *commits)
+{
+	int error;
+	git_commit_list *list;
+	git_commit *commit;
+
+	for (list = commits; list; list = list->next) {
+		if (!list->item->uninteresting)
+			continue;
+
+		if ((error = git_commit_lookup(&commit, pb->repo, &list->item->oid)) < 0)
+			return error;
+
+		error = mark_tree_uninteresting(pb, git_commit_tree_id(commit));
+		git_commit_free(commit);
+
+		if (error < 0)
+			return error;
+	}
+
+	return 0;
+}
+
+int insert_tree(git_packbuilder *pb, git_tree *tree)
+{
+	size_t i;
+	int error;
+	git_tree *subtree;
+	git_walk_object *obj;
+	const char *name;
+
+	if ((error = retrieve_object(&obj, pb, git_tree_id(tree))) < 0)
+		return error;
+
+	if (obj->seen || obj->uninteresting)
+		return 0;
+
+	obj->seen = 1;
+
+	if ((error = git_packbuilder_insert(pb, &obj->id, NULL)))
+		return error;
+
+	for (i = 0; i < git_tree_entrycount(tree); i++) {
+		const git_tree_entry *entry = git_tree_entry_byindex(tree, i);
+		const git_oid *entry_id = git_tree_entry_id(entry);
+		switch (git_tree_entry_type(entry)) {
+		case GIT_OBJ_TREE:
+			if ((error = git_tree_lookup(&subtree, pb->repo, entry_id)) < 0)
+				return error;
+
+			error = insert_tree(pb, subtree);
+			git_tree_free(subtree);
+
+			if (error < 0)
+				return error;
+
+			break;
+		case GIT_OBJ_BLOB:
+			if ((error = retrieve_object(&obj, pb, git_tree_id(tree))) < 0)
+				return error;
+			if (obj->uninteresting)
+				continue;
+			name = git_tree_entry_name(entry);
+			if ((error = git_packbuilder_insert(pb, entry_id, name)) < 0)
+				return error;
+			break;
+		default:
+			/* it's a submodule or something unknown, we don't want it */
+			;
+		}
+	}
+
+
+	return error;
+}
+
+int insert_commit(git_packbuilder *pb, git_walk_object *obj)
+{
+	int error;
+	git_commit *commit = NULL;
+	git_tree *tree = NULL;
+
+	obj->seen = 1;
+
+	if ((error = git_packbuilder_insert(pb, &obj->id, NULL)) < 0)
+		return error;
+
+	if ((error = git_commit_lookup(&commit, pb->repo, &obj->id)) < 0)
+		return error;
+
+	if ((error = git_tree_lookup(&tree, pb->repo, git_commit_tree_id(commit))) < 0)
+		goto cleanup;
+
+	if ((error = insert_tree(pb, tree)) < 0)
+		goto cleanup;
+
+cleanup:
+	git_commit_free(commit);
+	git_tree_free(tree);
+	return error;
+}
+
+int git_packbuilder_insert_walk(git_packbuilder *pb, git_revwalk *walk)
+{
+	int error;
+	git_oid id;
+	git_walk_object *obj;
+
+	assert(pb && walk);
+
+	if ((error = mark_edges_uninteresting(pb, walk->user_input)) < 0)
+		return error;
+
+	/*
+	 * TODO: git marks the parents of the edges
+	 * uninteresting. This may provide a speed advantage, but does
+	 * seem to assume the remote does not have a single-commit
+	 * history on the other end.
+	 */
+
+	/* walk down each tree up to the blobs and insert them, stopping when uninteresting */
+	while ((error = git_revwalk_next(&id, walk)) == 0) {
+		if ((error = retrieve_object(&obj, pb, &id)) < 0)
+			return error;
+
+		if (obj->seen || obj->uninteresting)
+			continue;
+
+		if ((error = insert_commit(pb, obj)) < 0)
+			return error;
+	}
+
+	if (error == GIT_ITEROVER)
+		error = 0;
+
+	return error;
+}
+
+int git_packbuilder_set_callbacks(git_packbuilder *pb, git_packbuilder_progress progress_cb, void *progress_cb_payload)
+{
+	if (!pb)
+		return -1;
+
+	pb->progress_cb = progress_cb;
+	pb->progress_cb_payload = progress_cb_payload;
+
+	return 0;
+}
+
+void git_packbuilder_free(git_packbuilder *pb)
+{
+	if (pb == NULL)
+		return;
+
+#ifdef GIT_THREADS
+
+	git_mutex_free(&pb->cache_mutex);
+	git_mutex_free(&pb->progress_mutex);
+	git_cond_free(&pb->progress_cond);
+
+#endif
+
+	if (pb->odb)
+		git_odb_free(pb->odb);
+
+	if (pb->object_ix)
+		git_oidmap_free(pb->object_ix);
+
+	if (pb->object_list)
+		git__free(pb->object_list);
+
+	git_oidmap_free(pb->walk_objects);
+	git_pool_clear(&pb->object_pool);
+
+	git_hash_ctx_cleanup(&pb->ctx);
+	git_zstream_free(&pb->zstream);
+
+	git__free(pb);
+}

vendor/libgit2-sys/libgit2/src/pack-objects.h

diff --git a/vendor/libgit2-sys/libgit2/src/pack-objects.h b/vendor/libgit2-sys/libgit2/src/pack-objects.h
new file mode 100644
index 0000000..c9cd577
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/pack-objects.h
@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_pack_objects_h__
+#define INCLUDE_pack_objects_h__
+
+#include "common.h"
+
+#include "buffer.h"
+#include "hash.h"
+#include "oidmap.h"
+#include "netops.h"
+#include "zstream.h"
+#include "pool.h"
+#include "indexer.h"
+
+#include "git2/oid.h"
+#include "git2/pack.h"
+
+#define GIT_PACK_WINDOW 10 /* number of objects to possibly delta against */
+#define GIT_PACK_DEPTH 50 /* max delta depth */
+#define GIT_PACK_DELTA_CACHE_SIZE (256 * 1024 * 1024)
+#define GIT_PACK_DELTA_CACHE_LIMIT 1000
+#define GIT_PACK_BIG_FILE_THRESHOLD (512 * 1024 * 1024)
+
+typedef struct git_pobject {
+	git_oid id;
+	git_otype type;
+	git_off_t offset;
+
+	size_t size;
+
+	unsigned int hash; /* name hint hash */
+
+	struct git_pobject *delta; /* delta base object */
+	struct git_pobject *delta_child; /* deltified objects who bases me */
+	struct git_pobject *delta_sibling; /* other deltified objects
+					    * who uses the same base as
+					    * me */
+
+	void *delta_data;
+	size_t delta_size;
+	size_t z_delta_size;
+
+	int written:1,
+	    recursing:1,
+	    tagged:1,
+	    filled:1;
+} git_pobject;
+
+typedef struct {
+	git_oid id;
+	unsigned int uninteresting:1,
+		seen:1;
+} git_walk_object;
+
+struct git_packbuilder {
+	git_repository *repo; /* associated repository */
+	git_odb *odb; /* associated object database */
+
+	git_hash_ctx ctx;
+	git_zstream zstream;
+
+	uint32_t nr_objects,
+		nr_deltified,
+		nr_written,
+		nr_remaining;
+
+	size_t nr_alloc;
+
+	git_pobject *object_list;
+
+	git_oidmap *object_ix;
+
+	git_oidmap *walk_objects;
+	git_pool object_pool;
+
+	git_oid pack_oid; /* hash of written pack */
+
+	/* synchronization objects */
+	git_mutex cache_mutex;
+	git_mutex progress_mutex;
+	git_cond progress_cond;
+
+	/* configs */
+	size_t delta_cache_size;
+	size_t max_delta_cache_size;
+	size_t cache_max_small_delta_size;
+	size_t big_file_threshold;
+	size_t window_memory_limit;
+
+	unsigned int nr_threads; /* nr of threads to use */
+
+	git_packbuilder_progress progress_cb;
+	void *progress_cb_payload;
+	double last_progress_report_time; /* the time progress was last reported */
+
+	bool done;
+};
+
+int git_packbuilder_write_buf(git_buf *buf, git_packbuilder *pb);
+
+#endif

vendor/libgit2-sys/libgit2/src/pack.c

diff --git a/vendor/libgit2-sys/libgit2/src/pack.c b/vendor/libgit2-sys/libgit2/src/pack.c
new file mode 100644
index 0000000..9ed3ec1
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/pack.c
@@ -0,0 +1,1408 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "pack.h"
+
+#include "odb.h"
+#include "delta.h"
+#include "sha1_lookup.h"
+#include "mwindow.h"
+#include "fileops.h"
+#include "oid.h"
+
+#include <zlib.h>
+
+static int packfile_open(struct git_pack_file *p);
+static git_off_t nth_packed_object_offset(const struct git_pack_file *p, uint32_t n);
+static int packfile_unpack_compressed(
+		git_rawobj *obj,
+		struct git_pack_file *p,
+		git_mwindow **w_curs,
+		git_off_t *curpos,
+		size_t size,
+		git_otype type);
+
+/* Can find the offset of an object given
+ * a prefix of an identifier.
+ * Throws GIT_EAMBIGUOUSOIDPREFIX if short oid
+ * is ambiguous within the pack.
+ * This method assumes that len is between
+ * GIT_OID_MINPREFIXLEN and GIT_OID_HEXSZ.
+ */
+static int pack_entry_find_offset(
+		git_off_t *offset_out,
+		git_oid *found_oid,
+		struct git_pack_file *p,
+		const git_oid *short_oid,
+		size_t len);
+
+static int packfile_error(const char *message)
+{
+	giterr_set(GITERR_ODB, "invalid pack file - %s", message);
+	return -1;
+}
+
+/********************
+ * Delta base cache
+ ********************/
+
+static git_pack_cache_entry *new_cache_object(git_rawobj *source)
+{
+	git_pack_cache_entry *e = git__calloc(1, sizeof(git_pack_cache_entry));
+	if (!e)
+		return NULL;
+
+	git_atomic_inc(&e->refcount);
+	memcpy(&e->raw, source, sizeof(git_rawobj));
+
+	return e;
+}
+
+static void free_cache_object(void *o)
+{
+	git_pack_cache_entry *e = (git_pack_cache_entry *)o;
+
+	if (e != NULL) {
+		assert(e->refcount.val == 0);
+		git__free(e->raw.data);
+		git__free(e);
+	}
+}
+
+static void cache_free(git_pack_cache *cache)
+{
+	git_pack_cache_entry *entry;
+
+	if (cache->entries) {
+		git_offmap_foreach_value(cache->entries, entry, {
+			free_cache_object(entry);
+		});
+
+		git_offmap_free(cache->entries);
+		cache->entries = NULL;
+	}
+}
+
+static int cache_init(git_pack_cache *cache)
+{
+	cache->entries = git_offmap_alloc();
+	GITERR_CHECK_ALLOC(cache->entries);
+
+	cache->memory_limit = GIT_PACK_CACHE_MEMORY_LIMIT;
+
+	if (git_mutex_init(&cache->lock)) {
+		giterr_set(GITERR_OS, "failed to initialize pack cache mutex");
+
+		git__free(cache->entries);
+		cache->entries = NULL;
+
+		return -1;
+	}
+
+	return 0;
+}
+
+static git_pack_cache_entry *cache_get(git_pack_cache *cache, git_off_t offset)
+{
+	khiter_t k;
+	git_pack_cache_entry *entry = NULL;
+
+	if (git_mutex_lock(&cache->lock) < 0)
+		return NULL;
+
+	k = git_offmap_lookup_index(cache->entries, offset);
+	if (git_offmap_valid_index(cache->entries, k)) { /* found it */
+		entry = git_offmap_value_at(cache->entries, k);
+		git_atomic_inc(&entry->refcount);
+		entry->last_usage = cache->use_ctr++;
+	}
+	git_mutex_unlock(&cache->lock);
+
+	return entry;
+}
+
+/* Run with the cache lock held */
+static void free_lowest_entry(git_pack_cache *cache)
+{
+	git_off_t offset;
+	git_pack_cache_entry *entry;
+
+	git_offmap_foreach(cache->entries, offset, entry, {
+		if (entry && entry->refcount.val == 0) {
+			cache->memory_used -= entry->raw.len;
+			git_offmap_delete(cache->entries, offset);
+			free_cache_object(entry);
+		}
+	});
+}
+
+static int cache_add(
+		git_pack_cache_entry **cached_out,
+		git_pack_cache *cache,
+		git_rawobj *base,
+		git_off_t offset)
+{
+	git_pack_cache_entry *entry;
+	int error, exists = 0;
+	khiter_t k;
+
+	if (base->len > GIT_PACK_CACHE_SIZE_LIMIT)
+		return -1;
+
+	entry = new_cache_object(base);
+	if (entry) {
+		if (git_mutex_lock(&cache->lock) < 0) {
+			giterr_set(GITERR_OS, "failed to lock cache");
+			git__free(entry);
+			return -1;
+		}
+		/* Add it to the cache if nobody else has */
+		exists = git_offmap_exists(cache->entries, offset);
+		if (!exists) {
+			while (cache->memory_used + base->len > cache->memory_limit)
+				free_lowest_entry(cache);
+
+			k = git_offmap_put(cache->entries, offset, &error);
+			assert(error != 0);
+			git_offmap_set_value_at(cache->entries, k, entry);
+			cache->memory_used += entry->raw.len;
+
+			*cached_out = entry;
+		}
+		git_mutex_unlock(&cache->lock);
+		/* Somebody beat us to adding it into the cache */
+		if (exists) {
+			git__free(entry);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+/***********************************************************
+ *
+ * PACK INDEX METHODS
+ *
+ ***********************************************************/
+
+static void pack_index_free(struct git_pack_file *p)
+{
+	if (p->oids) {
+		git__free(p->oids);
+		p->oids = NULL;
+	}
+	if (p->index_map.data) {
+		git_futils_mmap_free(&p->index_map);
+		p->index_map.data = NULL;
+	}
+}
+
+static int pack_index_check(const char *path, struct git_pack_file *p)
+{
+	struct git_pack_idx_header *hdr;
+	uint32_t version, nr, i, *index;
+	void *idx_map;
+	size_t idx_size;
+	struct stat st;
+	int error;
+	/* TODO: properly open the file without access time using O_NOATIME */
+	git_file fd = git_futils_open_ro(path);
+	if (fd < 0)
+		return fd;
+
+	if (p_fstat(fd, &st) < 0) {
+		p_close(fd);
+		giterr_set(GITERR_OS, "unable to stat pack index '%s'", path);
+		return -1;
+	}
+
+	if (!S_ISREG(st.st_mode) ||
+		!git__is_sizet(st.st_size) ||
+		(idx_size = (size_t)st.st_size) < 4 * 256 + 20 + 20)
+	{
+		p_close(fd);
+		giterr_set(GITERR_ODB, "invalid pack index '%s'", path);
+		return -1;
+	}
+
+	error = git_futils_mmap_ro(&p->index_map, fd, 0, idx_size);
+
+	p_close(fd);
+
+	if (error < 0)
+		return error;
+
+	hdr = idx_map = p->index_map.data;
+
+	if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
+		version = ntohl(hdr->idx_version);
+
+		if (version < 2 || version > 2) {
+			git_futils_mmap_free(&p->index_map);
+			return packfile_error("unsupported index version");
+		}
+
+	} else
+		version = 1;
+
+	nr = 0;
+	index = idx_map;
+
+	if (version > 1)
+		index += 2; /* skip index header */
+
+	for (i = 0; i < 256; i++) {
+		uint32_t n = ntohl(index[i]);
+		if (n < nr) {
+			git_futils_mmap_free(&p->index_map);
+			return packfile_error("index is non-monotonic");
+		}
+		nr = n;
+	}
+
+	if (version == 1) {
+		/*
+		 * Total size:
+		 * - 256 index entries 4 bytes each
+		 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
+		 * - 20-byte SHA1 of the packfile
+		 * - 20-byte SHA1 file checksum
+		 */
+		if (idx_size != 4*256 + nr * 24 + 20 + 20) {
+			git_futils_mmap_free(&p->index_map);
+			return packfile_error("index is corrupted");
+		}
+	} else if (version == 2) {
+		/*
+		 * Minimum size:
+		 * - 8 bytes of header
+		 * - 256 index entries 4 bytes each
+		 * - 20-byte sha1 entry * nr
+		 * - 4-byte crc entry * nr
+		 * - 4-byte offset entry * nr
+		 * - 20-byte SHA1 of the packfile
+		 * - 20-byte SHA1 file checksum
+		 * And after the 4-byte offset table might be a
+		 * variable sized table containing 8-byte entries
+		 * for offsets larger than 2^31.
+		 */
+		unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
+		unsigned long max_size = min_size;
+
+		if (nr)
+			max_size += (nr - 1)*8;
+
+		if (idx_size < min_size || idx_size > max_size) {
+			git_futils_mmap_free(&p->index_map);
+			return packfile_error("wrong index size");
+		}
+	}
+
+	p->num_objects = nr;
+	p->index_version = version;
+	return 0;
+}
+
+static int pack_index_open(struct git_pack_file *p)
+{
+	int error = 0;
+	size_t name_len;
+	git_buf idx_name;
+
+	if (p->index_version > -1)
+		return 0;
+
+	name_len = strlen(p->pack_name);
+	assert(name_len > strlen(".pack")); /* checked by git_pack_file alloc */
+
+	if (git_buf_init(&idx_name, name_len) < 0)
+		return -1;
+
+	git_buf_put(&idx_name, p->pack_name, name_len - strlen(".pack"));
+	git_buf_puts(&idx_name, ".idx");
+	if (git_buf_oom(&idx_name)) {
+		git_buf_free(&idx_name);
+		return -1;
+	}
+
+	if ((error = git_mutex_lock(&p->lock)) < 0) {
+		git_buf_free(&idx_name);
+		return error;
+	}
+
+	if (p->index_version == -1)
+		error = pack_index_check(idx_name.ptr, p);
+
+	git_buf_free(&idx_name);
+
+	git_mutex_unlock(&p->lock);
+
+	return error;
+}
+
+static unsigned char *pack_window_open(
+		struct git_pack_file *p,
+		git_mwindow **w_cursor,
+		git_off_t offset,
+		unsigned int *left)
+{
+	if (p->mwf.fd == -1 && packfile_open(p) < 0)
+		return NULL;
+
+	/* Since packfiles end in a hash of their content and it's
+	 * pointless to ask for an offset into the middle of that
+	 * hash, and the pack_window_contains function above wouldn't match
+	 * don't allow an offset too close to the end of the file.
+	 *
+	 * Don't allow a negative offset, as that means we've wrapped
+	 * around.
+	 */
+	if (offset > (p->mwf.size - 20))
+		return NULL;
+	if (offset < 0)
+		return NULL;
+
+	return git_mwindow_open(&p->mwf, w_cursor, offset, 20, left);
+ }
+
+/*
+ * The per-object header is a pretty dense thing, which is
+ *  - first byte: low four bits are "size",
+ *    then three bits of "type",
+ *    with the high bit being "size continues".
+ *  - each byte afterwards: low seven bits are size continuation,
+ *    with the high bit being "size continues"
+ */
+size_t git_packfile__object_header(unsigned char *hdr, size_t size, git_otype type)
+{
+	unsigned char *hdr_base;
+	unsigned char c;
+
+	assert(type >= GIT_OBJ_COMMIT && type <= GIT_OBJ_REF_DELTA);
+
+	/* TODO: add support for chunked objects; see git.git 6c0d19b1 */
+
+	c = (unsigned char)((type << 4) | (size & 15));
+	size >>= 4;
+	hdr_base = hdr;
+
+	while (size) {
+		*hdr++ = c | 0x80;
+		c = size & 0x7f;
+		size >>= 7;
+	}
+	*hdr++ = c;
+
+	return (hdr - hdr_base);
+}
+
+
+static int packfile_unpack_header1(
+		unsigned long *usedp,
+		size_t *sizep,
+		git_otype *type,
+		const unsigned char *buf,
+		unsigned long len)
+{
+	unsigned shift;
+	unsigned long size, c;
+	unsigned long used = 0;
+
+	c = buf[used++];
+	*type = (c >> 4) & 7;
+	size = c & 15;
+	shift = 4;
+	while (c & 0x80) {
+		if (len <= used) {
+			giterr_set(GITERR_ODB, "buffer too small");
+			return GIT_EBUFS;
+		}
+
+		if (bitsizeof(long) <= shift) {
+			*usedp = 0;
+			giterr_set(GITERR_ODB, "packfile corrupted");
+			return -1;
+		}
+
+		c = buf[used++];
+		size += (c & 0x7f) << shift;
+		shift += 7;
+	}
+
+	*sizep = (size_t)size;
+	*usedp = used;
+	return 0;
+}
+
+int git_packfile_unpack_header(
+		size_t *size_p,
+		git_otype *type_p,
+		git_mwindow_file *mwf,
+		git_mwindow **w_curs,
+		git_off_t *curpos)
+{
+	unsigned char *base;
+	unsigned int left;
+	unsigned long used;
+	int ret;
+
+	/* pack_window_open() assures us we have [base, base + 20) available
+	 * as a range that we can look at at. (Its actually the hash
+	 * size that is assured.) With our object header encoding
+	 * the maximum deflated object size is 2^137, which is just
+	 * insane, so we know won't exceed what we have been given.
+	 */
+/*	base = pack_window_open(p, w_curs, *curpos, &left); */
+	base = git_mwindow_open(mwf, w_curs, *curpos, 20, &left);
+	if (base == NULL)
+		return GIT_EBUFS;
+
+	ret = packfile_unpack_header1(&used, size_p, type_p, base, left);
+	git_mwindow_close(w_curs);
+	if (ret == GIT_EBUFS)
+		return ret;
+	else if (ret < 0)
+		return packfile_error("header length is zero");
+
+	*curpos += used;
+	return 0;
+}
+
+int git_packfile_resolve_header(
+		size_t *size_p,
+		git_otype *type_p,
+		struct git_pack_file *p,
+		git_off_t offset)
+{
+	git_mwindow *w_curs = NULL;
+	git_off_t curpos = offset;
+	size_t size;
+	git_otype type;
+	git_off_t base_offset;
+	int error;
+
+	error = git_packfile_unpack_header(&size, &type, &p->mwf, &w_curs, &curpos);
+	if (error < 0)
+		return error;
+
+	if (type == GIT_OBJ_OFS_DELTA || type == GIT_OBJ_REF_DELTA) {
+		size_t base_size;
+		git_packfile_stream stream;
+
+		base_offset = get_delta_base(p, &w_curs, &curpos, type, offset);
+		git_mwindow_close(&w_curs);
+		if ((error = git_packfile_stream_open(&stream, p, curpos)) < 0)
+			return error;
+		error = git_delta_read_header_fromstream(&base_size, size_p, &stream);
+		git_packfile_stream_free(&stream);
+		if (error < 0)
+			return error;
+	} else {
+		*size_p = size;
+		base_offset = 0;
+	}
+
+	while (type == GIT_OBJ_OFS_DELTA || type == GIT_OBJ_REF_DELTA) {
+		curpos = base_offset;
+		error = git_packfile_unpack_header(&size, &type, &p->mwf, &w_curs, &curpos);
+		if (error < 0)
+			return error;
+		if (type != GIT_OBJ_OFS_DELTA && type != GIT_OBJ_REF_DELTA)
+			break;
+		base_offset = get_delta_base(p, &w_curs, &curpos, type, base_offset);
+		git_mwindow_close(&w_curs);
+	}
+	*type_p = type;
+
+	return error;
+}
+
+#define SMALL_STACK_SIZE 64
+
+/**
+ * Generate the chain of dependencies which we need to get to the
+ * object at `off`. `chain` is used a stack, popping gives the right
+ * order to apply deltas on. If an object is found in the pack's base
+ * cache, we stop calculating there.
+ */
+static int pack_dependency_chain(git_dependency_chain *chain_out,
+				 git_pack_cache_entry **cached_out, git_off_t *cached_off,
+				 struct pack_chain_elem *small_stack, size_t *stack_sz,
+				 struct git_pack_file *p, git_off_t obj_offset)
+{
+	git_dependency_chain chain = GIT_ARRAY_INIT;
+	git_mwindow *w_curs = NULL;
+	git_off_t curpos = obj_offset, base_offset;
+	int error = 0, use_heap = 0;
+	size_t size, elem_pos;
+	git_otype type;
+
+	elem_pos = 0;
+	while (true) {
+		struct pack_chain_elem *elem;
+		git_pack_cache_entry *cached = NULL;
+
+		/* if we have a base cached, we can stop here instead */
+		if ((cached = cache_get(&p->bases, obj_offset)) != NULL) {
+			*cached_out = cached;
+			*cached_off = obj_offset;
+			break;
+		}
+
+		/* if we run out of space on the small stack, use the array */
+		if (elem_pos == SMALL_STACK_SIZE) {
+			git_array_init_to_size(chain, elem_pos);
+			GITERR_CHECK_ARRAY(chain);
+			memcpy(chain.ptr, small_stack, elem_pos * sizeof(struct pack_chain_elem));
+			chain.size = elem_pos;
+			use_heap = 1;
+		}
+
+		curpos = obj_offset;
+		if (!use_heap) {
+			elem = &small_stack[elem_pos];
+		} else {
+			elem = git_array_alloc(chain);
+			if (!elem) {
+				error = -1;
+				goto on_error;
+			}
+		}
+
+		elem->base_key = obj_offset;
+
+		error = git_packfile_unpack_header(&size, &type, &p->mwf, &w_curs, &curpos);
+
+		if (error < 0)
+			goto on_error;
+
+		elem->offset = curpos;
+		elem->size = size;
+		elem->type = type;
+		elem->base_key = obj_offset;
+
+		if (type != GIT_OBJ_OFS_DELTA && type != GIT_OBJ_REF_DELTA)
+			break;
+
+		base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
+		git_mwindow_close(&w_curs);
+
+		if (base_offset == 0) {
+			error = packfile_error("delta offset is zero");
+			goto on_error;
+		}
+		if (base_offset < 0) { /* must actually be an error code */
+			error = (int)base_offset;
+			goto on_error;
+		}
+
+		/* we need to pass the pos *after* the delta-base bit */
+		elem->offset = curpos;
+
+		/* go through the loop again, but with the new object */
+		obj_offset = base_offset;
+		elem_pos++;
+	}
+
+	
+	*stack_sz = elem_pos + 1;
+	*chain_out = chain;
+	return error;
+
+on_error:
+	git_array_clear(chain);
+	return error;
+}
+
+int git_packfile_unpack(
+	git_rawobj *obj,
+	struct git_pack_file *p,
+	git_off_t *obj_offset)
+{
+	git_mwindow *w_curs = NULL;
+	git_off_t curpos = *obj_offset;
+	int error, free_base = 0;
+	git_dependency_chain chain = GIT_ARRAY_INIT;
+	struct pack_chain_elem *elem = NULL, *stack;
+	git_pack_cache_entry *cached = NULL;
+	struct pack_chain_elem small_stack[SMALL_STACK_SIZE];
+	size_t stack_size = 0, elem_pos, alloclen;
+	git_otype base_type;
+
+	/*
+	 * TODO: optionally check the CRC on the packfile
+	 */
+
+	error = pack_dependency_chain(&chain, &cached, obj_offset, small_stack, &stack_size, p, *obj_offset);
+	if (error < 0)
+		return error;
+
+	obj->data = NULL;
+	obj->len = 0;
+	obj->type = GIT_OBJ_BAD;
+
+	/* let's point to the right stack */
+	stack = chain.ptr ? chain.ptr : small_stack;
+
+	elem_pos = stack_size;
+	if (cached) {
+		memcpy(obj, &cached->raw, sizeof(git_rawobj));
+		base_type = obj->type;
+		elem_pos--;	/* stack_size includes the base, which isn't actually there */
+	} else {
+		elem = &stack[--elem_pos];
+		base_type = elem->type;
+	}
+
+	switch (base_type) {
+	case GIT_OBJ_COMMIT:
+	case GIT_OBJ_TREE:
+	case GIT_OBJ_BLOB:
+	case GIT_OBJ_TAG:
+		if (!cached) {
+			curpos = elem->offset;
+			error = packfile_unpack_compressed(obj, p, &w_curs, &curpos, elem->size, elem->type);
+			git_mwindow_close(&w_curs);
+			base_type = elem->type;
+		}
+		if (error < 0)
+			goto cleanup;
+		break;
+	case GIT_OBJ_OFS_DELTA:
+	case GIT_OBJ_REF_DELTA:
+		error = packfile_error("dependency chain ends in a delta");
+		goto cleanup;
+	default:
+		error = packfile_error("invalid packfile type in header");
+		goto cleanup;
+	}
+
+	/*
+	 * Finding the object we want a cached base element is
+	 * problematic, as we need to make sure we don't accidentally
+	 * give the caller the cached object, which it would then feel
+	 * free to free, so we need to copy the data.
+	 */
+	if (cached && stack_size == 1) {
+		void *data = obj->data;
+
+		GITERR_CHECK_ALLOC_ADD(&alloclen, obj->len, 1);
+		obj->data = git__malloc(alloclen);
+		GITERR_CHECK_ALLOC(obj->data);
+
+		memcpy(obj->data, data, obj->len + 1);
+		git_atomic_dec(&cached->refcount);
+		goto cleanup;
+	}
+
+	/* we now apply each consecutive delta until we run out */
+	while (elem_pos > 0 && !error) {
+		git_rawobj base, delta;
+
+		/*
+		 * We can now try to add the base to the cache, as
+		 * long as it's not already the cached one.
+		 */
+		if (!cached)
+			free_base = !!cache_add(&cached, &p->bases, obj, elem->base_key);
+
+		elem = &stack[elem_pos - 1];
+		curpos = elem->offset;
+		error = packfile_unpack_compressed(&delta, p, &w_curs, &curpos, elem->size, elem->type);
+		git_mwindow_close(&w_curs);
+
+		if (error < 0) {
+			/* We have transferred ownership of the data to the cache. */
+			obj->data = NULL;
+			break;
+		}
+
+		/* the current object becomes the new base, on which we apply the delta */
+		base = *obj;
+		obj->data = NULL;
+		obj->len = 0;
+		obj->type = GIT_OBJ_BAD;
+
+		error = git_delta_apply(&obj->data, &obj->len, base.data, base.len, delta.data, delta.len);
+		obj->type = base_type;
+
+		/*
+		 * We usually don't want to free the base at this
+		 * point, as we put it into the cache in the previous
+		 * iteration. free_base lets us know that we got the
+		 * base object directly from the packfile, so we can free it.
+		 */
+		git__free(delta.data);
+		if (free_base) {
+			free_base = 0;
+			git__free(base.data);
+		}
+
+		if (cached) {
+			git_atomic_dec(&cached->refcount);
+			cached = NULL;
+		}
+
+		if (error < 0)
+			break;
+
+		elem_pos--;
+	}
+
+cleanup:
+	if (error < 0) {
+		git__free(obj->data);
+		if (cached)
+			git_atomic_dec(&cached->refcount);
+	}
+
+	if (elem)
+		*obj_offset = curpos;
+
+	git_array_clear(chain);
+	return error;
+}
+
+static void *use_git_alloc(void *opaq, unsigned int count, unsigned int size)
+{
+	GIT_UNUSED(opaq);
+	return git__calloc(count, size);
+}
+
+static void use_git_free(void *opaq, void *ptr)
+{
+	GIT_UNUSED(opaq);
+	git__free(ptr);
+}
+
+int git_packfile_stream_open(git_packfile_stream *obj, struct git_pack_file *p, git_off_t curpos)
+{
+	int st;
+
+	memset(obj, 0, sizeof(git_packfile_stream));
+	obj->curpos = curpos;
+	obj->p = p;
+	obj->zstream.zalloc = use_git_alloc;
+	obj->zstream.zfree = use_git_free;
+	obj->zstream.next_in = Z_NULL;
+	obj->zstream.next_out = Z_NULL;
+	st = inflateInit(&obj->zstream);
+	if (st != Z_OK) {
+		giterr_set(GITERR_ZLIB, "failed to init packfile stream");
+		return -1;
+	}
+
+	return 0;
+}
+
+ssize_t git_packfile_stream_read(git_packfile_stream *obj, void *buffer, size_t len)
+{
+	unsigned char *in;
+	size_t written;
+	int st;
+
+	if (obj->done)
+		return 0;
+
+	in = pack_window_open(obj->p, &obj->mw, obj->curpos, &obj->zstream.avail_in);
+	if (in == NULL)
+		return GIT_EBUFS;
+
+	obj->zstream.next_out = buffer;
+	obj->zstream.avail_out = (unsigned int)len;
+	obj->zstream.next_in = in;
+
+	st = inflate(&obj->zstream, Z_SYNC_FLUSH);
+	git_mwindow_close(&obj->mw);
+
+	obj->curpos += obj->zstream.next_in - in;
+	written = len - obj->zstream.avail_out;
+
+	if (st != Z_OK && st != Z_STREAM_END) {
+		giterr_set(GITERR_ZLIB, "error reading from the zlib stream");
+		return -1;
+	}
+
+	if (st == Z_STREAM_END)
+		obj->done = 1;
+
+
+	/* If we didn't write anything out but we're not done, we need more data */
+	if (!written && st != Z_STREAM_END)
+		return GIT_EBUFS;
+
+	return written;
+
+}
+
+void git_packfile_stream_free(git_packfile_stream *obj)
+{
+	inflateEnd(&obj->zstream);
+}
+
+static int packfile_unpack_compressed(
+	git_rawobj *obj,
+	struct git_pack_file *p,
+	git_mwindow **w_curs,
+	git_off_t *curpos,
+	size_t size,
+	git_otype type)
+{
+	size_t buf_size;
+	int st;
+	z_stream stream;
+	unsigned char *buffer, *in;
+
+	GITERR_CHECK_ALLOC_ADD(&buf_size, size, 1);
+	buffer = git__calloc(1, buf_size);
+	GITERR_CHECK_ALLOC(buffer);
+
+	memset(&stream, 0, sizeof(stream));
+	stream.next_out = buffer;
+	stream.avail_out = (uInt)buf_size;
+	stream.zalloc = use_git_alloc;
+	stream.zfree = use_git_free;
+
+	st = inflateInit(&stream);
+	if (st != Z_OK) {
+		git__free(buffer);
+		giterr_set(GITERR_ZLIB, "failed to init zlib stream on unpack");
+
+		return -1;
+	}
+
+	do {
+		in = pack_window_open(p, w_curs, *curpos, &stream.avail_in);
+		stream.next_in = in;
+		st = inflate(&stream, Z_FINISH);
+		git_mwindow_close(w_curs);
+
+		if (!stream.avail_out)
+			break; /* the payload is larger than it should be */
+
+		if (st == Z_BUF_ERROR && in == NULL) {
+			inflateEnd(&stream);
+			git__free(buffer);
+			return GIT_EBUFS;
+		}
+
+		*curpos += stream.next_in - in;
+	} while (st == Z_OK || st == Z_BUF_ERROR);
+
+	inflateEnd(&stream);
+
+	if ((st != Z_STREAM_END) || stream.total_out != size) {
+		git__free(buffer);
+		giterr_set(GITERR_ZLIB, "error inflating zlib stream");
+		return -1;
+	}
+
+	obj->type = type;
+	obj->len = size;
+	obj->data = buffer;
+	return 0;
+}
+
+/*
+ * curpos is where the data starts, delta_obj_offset is the where the
+ * header starts
+ */
+git_off_t get_delta_base(
+	struct git_pack_file *p,
+	git_mwindow **w_curs,
+	git_off_t *curpos,
+	git_otype type,
+	git_off_t delta_obj_offset)
+{
+	unsigned int left = 0;
+	unsigned char *base_info;
+	git_off_t base_offset;
+	git_oid unused;
+
+	base_info = pack_window_open(p, w_curs, *curpos, &left);
+	/* Assumption: the only reason this would fail is because the file is too small */
+	if (base_info == NULL)
+		return GIT_EBUFS;
+	/* pack_window_open() assured us we have [base_info, base_info + 20)
+	 * as a range that we can look at without walking off the
+	 * end of the mapped window. Its actually the hash size
+	 * that is assured. An OFS_DELTA longer than the hash size
+	 * is stupid, as then a REF_DELTA would be smaller to store.
+	 */
+	if (type == GIT_OBJ_OFS_DELTA) {
+		unsigned used = 0;
+		unsigned char c = base_info[used++];
+		size_t unsigned_base_offset = c & 127;
+		while (c & 128) {
+			if (left <= used)
+				return GIT_EBUFS;
+			unsigned_base_offset += 1;
+			if (!unsigned_base_offset || MSB(unsigned_base_offset, 7))
+				return 0; /* overflow */
+			c = base_info[used++];
+			unsigned_base_offset = (unsigned_base_offset << 7) + (c & 127);
+		}
+		if (unsigned_base_offset == 0 || (size_t)delta_obj_offset <= unsigned_base_offset)
+			return 0; /* out of bound */
+		base_offset = delta_obj_offset - unsigned_base_offset;
+		*curpos += used;
+	} else if (type == GIT_OBJ_REF_DELTA) {
+		/* If we have the cooperative cache, search in it first */
+		if (p->has_cache) {
+			khiter_t k;
+			git_oid oid;
+
+			git_oid_fromraw(&oid, base_info);
+			k = git_oidmap_lookup_index(p->idx_cache, &oid);
+			if (git_oidmap_valid_index(p->idx_cache, k)) {
+				*curpos += 20;
+				return ((struct git_pack_entry *)git_oidmap_value_at(p->idx_cache, k))->offset;
+			} else {
+				/* If we're building an index, don't try to find the pack
+				 * entry; we just haven't seen it yet.  We'll make
+				 * progress again in the next loop.
+				 */
+				return GIT_PASSTHROUGH;
+			}
+		}
+
+		/* The base entry _must_ be in the same pack */
+		if (pack_entry_find_offset(&base_offset, &unused, p, (git_oid *)base_info, GIT_OID_HEXSZ) < 0)
+			return packfile_error("base entry delta is not in the same pack");
+		*curpos += 20;
+	} else
+		return 0;
+
+	return base_offset;
+}
+
+/***********************************************************
+ *
+ * PACKFILE METHODS
+ *
+ ***********************************************************/
+
+void git_packfile_close(struct git_pack_file *p, bool unlink_packfile)
+{
+	if (p->mwf.fd >= 0) {
+		git_mwindow_free_all_locked(&p->mwf);
+		p_close(p->mwf.fd);
+		p->mwf.fd = -1;
+	}
+
+	if (unlink_packfile)
+		p_unlink(p->pack_name);
+}
+
+void git_packfile_free(struct git_pack_file *p)
+{
+	if (!p)
+		return;
+
+	cache_free(&p->bases);
+
+	git_packfile_close(p, false);
+
+	pack_index_free(p);
+
+	git__free(p->bad_object_sha1);
+
+	git_mutex_free(&p->lock);
+	git_mutex_free(&p->bases.lock);
+	git__free(p);
+}
+
+static int packfile_open(struct git_pack_file *p)
+{
+	struct stat st;
+	struct git_pack_header hdr;
+	git_oid sha1;
+	unsigned char *idx_sha1;
+
+	if (p->index_version == -1 && pack_index_open(p) < 0)
+		return git_odb__error_notfound("failed to open packfile", NULL, 0);
+
+	/* if mwf opened by another thread, return now */
+	if (git_mutex_lock(&p->lock) < 0)
+		return packfile_error("failed to get lock for open");
+
+	if (p->mwf.fd >= 0) {
+		git_mutex_unlock(&p->lock);
+		return 0;
+	}
+
+	/* TODO: open with noatime */
+	p->mwf.fd = git_futils_open_ro(p->pack_name);
+	if (p->mwf.fd < 0)
+		goto cleanup;
+
+	if (p_fstat(p->mwf.fd, &st) < 0 ||
+		git_mwindow_file_register(&p->mwf) < 0)
+		goto cleanup;
+
+	/* If we created the struct before we had the pack we lack size. */
+	if (!p->mwf.size) {
+		if (!S_ISREG(st.st_mode))
+			goto cleanup;
+		p->mwf.size = (git_off_t)st.st_size;
+	} else if (p->mwf.size != st.st_size)
+		goto cleanup;
+
+#if 0
+	/* We leave these file descriptors open with sliding mmap;
+	 * there is no point keeping them open across exec(), though.
+	 */
+	fd_flag = fcntl(p->mwf.fd, F_GETFD, 0);
+	if (fd_flag < 0)
+		goto cleanup;
+
+	fd_flag |= FD_CLOEXEC;
+	if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
+		goto cleanup;
+#endif
+
+	/* Verify we recognize this pack file format. */
+	if (p_read(p->mwf.fd, &hdr, sizeof(hdr)) < 0 ||
+		hdr.hdr_signature != htonl(PACK_SIGNATURE) ||
+		!pack_version_ok(hdr.hdr_version))
+		goto cleanup;
+
+	/* Verify the pack matches its index. */
+	if (p->num_objects != ntohl(hdr.hdr_entries) ||
+		p_lseek(p->mwf.fd, p->mwf.size - GIT_OID_RAWSZ, SEEK_SET) == -1 ||
+		p_read(p->mwf.fd, sha1.id, GIT_OID_RAWSZ) < 0)
+		goto cleanup;
+
+	idx_sha1 = ((unsigned char *)p->index_map.data) + p->index_map.len - 40;
+
+	if (git_oid__cmp(&sha1, (git_oid *)idx_sha1) != 0)
+		goto cleanup;
+
+	git_mutex_unlock(&p->lock);
+	return 0;
+
+cleanup:
+	giterr_set(GITERR_OS, "invalid packfile '%s'", p->pack_name);
+
+	if (p->mwf.fd >= 0)
+		p_close(p->mwf.fd);
+	p->mwf.fd = -1;
+
+	git_mutex_unlock(&p->lock);
+
+	return -1;
+}
+
+int git_packfile__name(char **out, const char *path)
+{
+	size_t path_len;
+	git_buf buf = GIT_BUF_INIT;
+
+	path_len = strlen(path);
+
+	if (path_len < strlen(".idx"))
+		return git_odb__error_notfound("invalid packfile path", NULL, 0);
+
+	if (git_buf_printf(&buf, "%.*s.pack", (int)(path_len - strlen(".idx")), path) < 0)
+		return -1;
+
+	*out = git_buf_detach(&buf);
+	return 0;
+}
+
+int git_packfile_alloc(struct git_pack_file **pack_out, const char *path)
+{
+	struct stat st;
+	struct git_pack_file *p;
+	size_t path_len = path ? strlen(path) : 0, alloc_len;
+
+	*pack_out = NULL;
+
+	if (path_len < strlen(".idx"))
+		return git_odb__error_notfound("invalid packfile path", NULL, 0);
+
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, sizeof(*p), path_len);
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, 2);
+
+	p = git__calloc(1, alloc_len);
+	GITERR_CHECK_ALLOC(p);
+
+	memcpy(p->pack_name, path, path_len + 1);
+
+	/*
+	 * Make sure a corresponding .pack file exists and that
+	 * the index looks sane.
+	 */
+	if (git__suffixcmp(path, ".idx") == 0) {
+		size_t root_len = path_len - strlen(".idx");
+
+		memcpy(p->pack_name + root_len, ".keep", sizeof(".keep"));
+		if (git_path_exists(p->pack_name) == true)
+			p->pack_keep = 1;
+
+		memcpy(p->pack_name + root_len, ".pack", sizeof(".pack"));
+	}
+
+	if (p_stat(p->pack_name, &st) < 0 || !S_ISREG(st.st_mode)) {
+		git__free(p);
+		return git_odb__error_notfound("packfile not found", NULL, 0);
+	}
+
+	/* ok, it looks sane as far as we can check without
+	 * actually mapping the pack file.
+	 */
+	p->mwf.fd = -1;
+	p->mwf.size = st.st_size;
+	p->pack_local = 1;
+	p->mtime = (git_time_t)st.st_mtime;
+	p->index_version = -1;
+
+	if (git_mutex_init(&p->lock)) {
+		giterr_set(GITERR_OS, "failed to initialize packfile mutex");
+		git__free(p);
+		return -1;
+	}
+
+	if (cache_init(&p->bases) < 0) {
+		git__free(p);
+		return -1;
+	}
+
+	*pack_out = p;
+
+	return 0;
+}
+
+/***********************************************************
+ *
+ * PACKFILE ENTRY SEARCH INTERNALS
+ *
+ ***********************************************************/
+
+static git_off_t nth_packed_object_offset(const struct git_pack_file *p, uint32_t n)
+{
+	const unsigned char *index = p->index_map.data;
+	const unsigned char *end = index + p->index_map.len;
+	index += 4 * 256;
+	if (p->index_version == 1) {
+		return ntohl(*((uint32_t *)(index + 24 * n)));
+	} else {
+		uint32_t off;
+		index += 8 + p->num_objects * (20 + 4);
+		off = ntohl(*((uint32_t *)(index + 4 * n)));
+		if (!(off & 0x80000000))
+			return off;
+		index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
+
+		/* Make sure we're not being sent out of bounds */
+		if (index >= end - 8)
+			return -1;
+
+		return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
+					ntohl(*((uint32_t *)(index + 4)));
+	}
+}
+
+static int git__memcmp4(const void *a, const void *b) {
+	return memcmp(a, b, 4);
+}
+
+int git_pack_foreach_entry(
+	struct git_pack_file *p,
+	git_odb_foreach_cb cb,
+	void *data)
+{
+	const unsigned char *index = p->index_map.data, *current;
+	uint32_t i;
+	int error = 0;
+
+	if (index == NULL) {
+		if ((error = pack_index_open(p)) < 0)
+			return error;
+
+		assert(p->index_map.data);
+
+		index = p->index_map.data;
+	}
+
+	if (p->index_version > 1) {
+		index += 8;
+	}
+
+	index += 4 * 256;
+
+	if (p->oids == NULL) {
+		git_vector offsets, oids;
+
+		if ((error = git_vector_init(&oids, p->num_objects, NULL)))
+			return error;
+
+		if ((error = git_vector_init(&offsets, p->num_objects, git__memcmp4)))
+			return error;
+
+		if (p->index_version > 1) {
+			const unsigned char *off = index + 24 * p->num_objects;
+			for (i = 0; i < p->num_objects; i++)
+				git_vector_insert(&offsets, (void*)&off[4 * i]);
+			git_vector_sort(&offsets);
+			git_vector_foreach(&offsets, i, current)
+				git_vector_insert(&oids, (void*)&index[5 * (current - off)]);
+		} else {
+			for (i = 0; i < p->num_objects; i++)
+				git_vector_insert(&offsets, (void*)&index[24 * i]);
+			git_vector_sort(&offsets);
+			git_vector_foreach(&offsets, i, current)
+				git_vector_insert(&oids, (void*)&current[4]);
+		}
+
+		git_vector_free(&offsets);
+		p->oids = (git_oid **)git_vector_detach(NULL, NULL, &oids);
+	}
+
+	for (i = 0; i < p->num_objects; i++)
+		if ((error = cb(p->oids[i], data)) != 0)
+			return giterr_set_after_callback(error);
+
+	return error;
+}
+
+static int pack_entry_find_offset(
+	git_off_t *offset_out,
+	git_oid *found_oid,
+	struct git_pack_file *p,
+	const git_oid *short_oid,
+	size_t len)
+{
+	const uint32_t *level1_ofs;
+	const unsigned char *index;
+	unsigned hi, lo, stride;
+	int pos, found = 0;
+	git_off_t offset;
+	const unsigned char *current = 0;
+
+	*offset_out = 0;
+
+	if (p->index_version == -1) {
+		int error;
+
+		if ((error = pack_index_open(p)) < 0)
+			return error;
+		assert(p->index_map.data);
+	}
+
+	index = p->index_map.data;
+	level1_ofs = p->index_map.data;
+
+	if (p->index_version > 1) {
+		level1_ofs += 2;
+		index += 8;
+	}
+
+	index += 4 * 256;
+	hi = ntohl(level1_ofs[(int)short_oid->id[0]]);
+	lo = ((short_oid->id[0] == 0x0) ? 0 : ntohl(level1_ofs[(int)short_oid->id[0] - 1]));
+
+	if (p->index_version > 1) {
+		stride = 20;
+	} else {
+		stride = 24;
+		index += 4;
+	}
+
+#ifdef INDEX_DEBUG_LOOKUP
+	printf("%02x%02x%02x... lo %u hi %u nr %d\n",
+		short_oid->id[0], short_oid->id[1], short_oid->id[2], lo, hi, p->num_objects);
+#endif
+
+	pos = sha1_position(index, stride, lo, hi, short_oid->id);
+
+	if (pos >= 0) {
+		/* An object matching exactly the oid was found */
+		found = 1;
+		current = index + pos * stride;
+	} else {
+		/* No object was found */
+		/* pos refers to the object with the "closest" oid to short_oid */
+		pos = - 1 - pos;
+		if (pos < (int)p->num_objects) {
+			current = index + pos * stride;
+
+			if (!git_oid_ncmp(short_oid, (const git_oid *)current, len))
+				found = 1;
+		}
+	}
+
+	if (found && len != GIT_OID_HEXSZ && pos + 1 < (int)p->num_objects) {
+		/* Check for ambiguousity */
+		const unsigned char *next = current + stride;
+
+		if (!git_oid_ncmp(short_oid, (const git_oid *)next, len)) {
+			found = 2;
+		}
+	}
+
+	if (!found)
+		return git_odb__error_notfound("failed to find offset for pack entry", short_oid, len);
+	if (found > 1)
+		return git_odb__error_ambiguous("found multiple offsets for pack entry");
+
+	if ((offset = nth_packed_object_offset(p, pos)) < 0) {
+		giterr_set(GITERR_ODB, "packfile index is corrupt");
+		return -1;
+	}
+
+	*offset_out = offset;
+	git_oid_fromraw(found_oid, current);
+
+#ifdef INDEX_DEBUG_LOOKUP
+	{
+		unsigned char hex_sha1[GIT_OID_HEXSZ + 1];
+		git_oid_fmt(hex_sha1, found_oid);
+		hex_sha1[GIT_OID_HEXSZ] = '\0';
+		printf("found lo=%d %s\n", lo, hex_sha1);
+	}
+#endif
+
+	return 0;
+}
+
+int git_pack_entry_find(
+		struct git_pack_entry *e,
+		struct git_pack_file *p,
+		const git_oid *short_oid,
+		size_t len)
+{
+	git_off_t offset;
+	git_oid found_oid;
+	int error;
+
+	assert(p);
+
+	if (len == GIT_OID_HEXSZ && p->num_bad_objects) {
+		unsigned i;
+		for (i = 0; i < p->num_bad_objects; i++)
+			if (git_oid__cmp(short_oid, &p->bad_object_sha1[i]) == 0)
+				return packfile_error("bad object found in packfile");
+	}
+
+	error = pack_entry_find_offset(&offset, &found_oid, p, short_oid, len);
+	if (error < 0)
+		return error;
+
+	/* we found a unique entry in the index;
+	 * make sure the packfile backing the index
+	 * still exists on disk */
+	if (p->mwf.fd == -1 && (error = packfile_open(p)) < 0)
+		return error;
+
+	e->offset = offset;
+	e->p = p;
+
+	git_oid_cpy(&e->sha1, &found_oid);
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/pack.h

diff --git a/vendor/libgit2-sys/libgit2/src/pack.h b/vendor/libgit2-sys/libgit2/src/pack.h
new file mode 100644
index 0000000..c0ca74f
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/pack.h
@@ -0,0 +1,167 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_pack_h__
+#define INCLUDE_pack_h__
+
+#include "common.h"
+
+#include <zlib.h>
+
+#include "git2/oid.h"
+
+#include "map.h"
+#include "mwindow.h"
+#include "odb.h"
+#include "oidmap.h"
+#include "array.h"
+
+#define GIT_PACK_FILE_MODE 0444
+
+#define PACK_SIGNATURE 0x5041434b	/* "PACK" */
+#define PACK_VERSION 2
+#define pack_version_ok(v) ((v) == htonl(2) || (v) == htonl(3))
+struct git_pack_header {
+	uint32_t hdr_signature;
+	uint32_t hdr_version;
+	uint32_t hdr_entries;
+};
+
+/*
+ * The first four bytes of index formats later than version 1 should
+ * start with this signature, as all older git binaries would find this
+ * value illegal and abort reading the file.
+ *
+ * This is the case because the number of objects in a packfile
+ * cannot exceed 1,431,660,000 as every object would need at least
+ * 3 bytes of data and the overall packfile cannot exceed 4 GiB with
+ * version 1 of the index file due to the offsets limited to 32 bits.
+ * Clearly the signature exceeds this maximum.
+ *
+ * Very old git binaries will also compare the first 4 bytes to the
+ * next 4 bytes in the index and abort with a "non-monotonic index"
+ * error if the second 4 byte word is smaller than the first 4
+ * byte word. This would be true in the proposed future index
+ * format as idx_signature would be greater than idx_version.
+ */
+
+#define PACK_IDX_SIGNATURE 0xff744f63	/* "\377tOc" */
+
+struct git_pack_idx_header {
+	uint32_t idx_signature;
+	uint32_t idx_version;
+};
+
+typedef struct git_pack_cache_entry {
+	size_t last_usage; /* enough? */
+	git_atomic refcount;
+	git_rawobj raw;
+} git_pack_cache_entry;
+
+struct pack_chain_elem {
+	git_off_t base_key;
+	git_off_t offset;
+	size_t size;
+	git_otype type;
+};
+
+typedef git_array_t(struct pack_chain_elem) git_dependency_chain;
+
+#include "offmap.h"
+#include "oidmap.h"
+
+#define GIT_PACK_CACHE_MEMORY_LIMIT 16 * 1024 * 1024
+#define GIT_PACK_CACHE_SIZE_LIMIT 1024 * 1024 /* don't bother caching anything over 1MB */
+
+typedef struct {
+	size_t memory_used;
+	size_t memory_limit;
+	size_t use_ctr;
+	git_mutex lock;
+	git_offmap *entries;
+} git_pack_cache;
+
+struct git_pack_file {
+	git_mwindow_file mwf;
+	git_map index_map;
+	git_mutex lock; /* protect updates to mwf and index_map */
+	git_atomic refcount;
+
+	uint32_t num_objects;
+	uint32_t num_bad_objects;
+	git_oid *bad_object_sha1; /* array of git_oid */
+
+	int index_version;
+	git_time_t mtime;
+	unsigned pack_local:1, pack_keep:1, has_cache:1;
+	git_oidmap *idx_cache;
+	git_oid **oids;
+
+	git_pack_cache bases; /* delta base cache */
+
+	time_t last_freshen; /* last time the packfile was freshened */
+
+	/* something like ".git/objects/pack/xxxxx.pack" */
+	char pack_name[GIT_FLEX_ARRAY]; /* more */
+};
+
+struct git_pack_entry {
+	git_off_t offset;
+	git_oid sha1;
+	struct git_pack_file *p;
+};
+
+typedef struct git_packfile_stream {
+	git_off_t curpos;
+	int done;
+	z_stream zstream;
+	struct git_pack_file *p;
+	git_mwindow *mw;
+} git_packfile_stream;
+
+size_t git_packfile__object_header(unsigned char *hdr, size_t size, git_otype type);
+
+int git_packfile__name(char **out, const char *path);
+
+int git_packfile_unpack_header(
+		size_t *size_p,
+		git_otype *type_p,
+		git_mwindow_file *mwf,
+		git_mwindow **w_curs,
+		git_off_t *curpos);
+
+int git_packfile_resolve_header(
+		size_t *size_p,
+		git_otype *type_p,
+		struct git_pack_file *p,
+		git_off_t offset);
+
+int git_packfile_unpack(git_rawobj *obj, struct git_pack_file *p, git_off_t *obj_offset);
+
+int git_packfile_stream_open(git_packfile_stream *obj, struct git_pack_file *p, git_off_t curpos);
+ssize_t git_packfile_stream_read(git_packfile_stream *obj, void *buffer, size_t len);
+void git_packfile_stream_free(git_packfile_stream *obj);
+
+git_off_t get_delta_base(struct git_pack_file *p, git_mwindow **w_curs,
+		git_off_t *curpos, git_otype type,
+		git_off_t delta_obj_offset);
+
+void git_packfile_close(struct git_pack_file *p, bool unlink_packfile);
+void git_packfile_free(struct git_pack_file *p);
+int git_packfile_alloc(struct git_pack_file **pack_out, const char *path);
+
+int git_pack_entry_find(
+		struct git_pack_entry *e,
+		struct git_pack_file *p,
+		const git_oid *short_oid,
+		size_t len);
+int git_pack_foreach_entry(
+		struct git_pack_file *p,
+		git_odb_foreach_cb cb,
+		void *data);
+
+#endif

vendor/libgit2-sys/libgit2/src/parse.c

diff --git a/vendor/libgit2-sys/libgit2/src/parse.c b/vendor/libgit2-sys/libgit2/src/parse.c
new file mode 100644
index 0000000..6b8902c
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/parse.c
@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#include "parse.h"
+
+int git_parse_ctx_init(git_parse_ctx *ctx, const char *content, size_t content_len)
+{
+	if (content_len)
+		ctx->content = content;
+	else
+		ctx->content = NULL;
+
+	ctx->content_len = content_len;
+	ctx->remain = ctx->content;
+	ctx->remain_len = ctx->content_len;
+	ctx->line = ctx->remain;
+	ctx->line_len = git__linenlen(ctx->line, ctx->remain_len);
+	ctx->line_num = 1;
+
+	return 0;
+}
+
+void git_parse_ctx_clear(git_parse_ctx *ctx)
+{
+	memset(ctx, 0, sizeof(*ctx));
+}
+
+void git_parse_advance_line(git_parse_ctx *ctx)
+{
+	ctx->line += ctx->line_len;
+	ctx->remain_len -= ctx->line_len;
+	ctx->line_len = git__linenlen(ctx->line, ctx->remain_len);
+	ctx->line_num++;
+}
+
+void git_parse_advance_chars(git_parse_ctx *ctx, size_t char_cnt)
+{
+	ctx->line += char_cnt;
+	ctx->remain_len -= char_cnt;
+	ctx->line_len -= char_cnt;
+}
+
+int git_parse_advance_expected(
+	git_parse_ctx *ctx,
+	const char *expected,
+	size_t expected_len)
+{
+	if (ctx->line_len < expected_len)
+		return -1;
+
+	if (memcmp(ctx->line, expected, expected_len) != 0)
+		return -1;
+
+	git_parse_advance_chars(ctx, expected_len);
+	return 0;
+}
+
+int git_parse_advance_ws(git_parse_ctx *ctx)
+{
+	int ret = -1;
+
+	while (ctx->line_len > 0 &&
+		ctx->line[0] != '\n' &&
+		git__isspace(ctx->line[0])) {
+		ctx->line++;
+		ctx->line_len--;
+		ctx->remain_len--;
+		ret = 0;
+	}
+
+	return ret;
+}
+
+int git_parse_advance_nl(git_parse_ctx *ctx)
+{
+	if (ctx->line_len != 1 || ctx->line[0] != '\n')
+		return -1;
+
+	git_parse_advance_line(ctx);
+	return 0;
+}
+
+int git_parse_advance_digit(int64_t *out, git_parse_ctx *ctx, int base)
+{
+	const char *end;
+	int ret;
+
+	if (ctx->line_len < 1 || !git__isdigit(ctx->line[0]))
+		return -1;
+
+	if ((ret = git__strntol64(out, ctx->line, ctx->line_len, &end, base)) < 0)
+		return -1;
+
+	git_parse_advance_chars(ctx, (end - ctx->line));
+	return 0;
+}
+
+int git_parse_peek(char *out, git_parse_ctx *ctx, int flags)
+{
+	size_t remain = ctx->line_len;
+	const char *ptr = ctx->line;
+
+	while (remain) {
+		char c = *ptr;
+
+		if ((flags & GIT_PARSE_PEEK_SKIP_WHITESPACE) &&
+		    git__isspace(c)) {
+			remain--;
+			ptr++;
+			continue;
+		}
+
+		*out = c;
+		return 0;
+	}
+
+	return -1;
+}

vendor/libgit2-sys/libgit2/src/parse.h

diff --git a/vendor/libgit2-sys/libgit2/src/parse.h b/vendor/libgit2-sys/libgit2/src/parse.h
new file mode 100644
index 0000000..46897e3
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/parse.h
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_parse_h__
+#define INCLUDE_parse_h__
+
+#include "common.h"
+
+typedef struct {
+	/* Original content buffer */
+	const char *content;
+	size_t content_len;
+
+	/* The remaining (unparsed) buffer */
+	const char *remain;
+	size_t remain_len;
+
+	const char *line;
+	size_t line_len;
+	size_t line_num;
+} git_parse_ctx;
+
+int git_parse_ctx_init(git_parse_ctx *ctx, const char *content, size_t content_len);
+void git_parse_ctx_clear(git_parse_ctx *ctx);
+
+#define git_parse_err(...) \
+	( giterr_set(GITERR_PATCH, __VA_ARGS__), -1 )
+
+#define git_parse_ctx_contains_s(ctx, str) \
+	git_parse_ctx_contains(ctx, str, sizeof(str) - 1)
+
+GIT_INLINE(bool) git_parse_ctx_contains(
+	git_parse_ctx *ctx, const char *str, size_t len)
+{
+	return (ctx->line_len >= len && memcmp(ctx->line, str, len) == 0);
+}
+
+void git_parse_advance_line(git_parse_ctx *ctx);
+void git_parse_advance_chars(git_parse_ctx *ctx, size_t char_cnt);
+int git_parse_advance_expected(
+	git_parse_ctx *ctx,
+	const char *expected,
+	size_t expected_len);
+
+#define git_parse_advance_expected_str(ctx, str) \
+	git_parse_advance_expected(ctx, str, strlen(str))
+
+int git_parse_advance_ws(git_parse_ctx *ctx);
+int git_parse_advance_nl(git_parse_ctx *ctx);
+int git_parse_advance_digit(int64_t *out, git_parse_ctx *ctx, int base);
+
+enum GIT_PARSE_PEEK_FLAGS {
+	GIT_PARSE_PEEK_SKIP_WHITESPACE = (1 << 0)
+};
+
+int git_parse_peek(char *out, git_parse_ctx *ctx, int flags);
+
+#endif

vendor/libgit2-sys/libgit2/src/patch.c

diff --git a/vendor/libgit2-sys/libgit2/src/patch.c b/vendor/libgit2-sys/libgit2/src/patch.c
new file mode 100644
index 0000000..5e32951
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/patch.c
@@ -0,0 +1,223 @@
+/*
+* Copyright (C) the libgit2 contributors. All rights reserved.
+*
+* This file is part of libgit2, distributed under the GNU GPL v2 with
+* a Linking Exception. For full terms see the included COPYING file.
+*/
+
+#include "patch.h"
+
+#include "git2/patch.h"
+#include "diff.h"
+
+int git_patch__invoke_callbacks(
+	git_patch *patch,
+	git_diff_file_cb file_cb,
+	git_diff_binary_cb binary_cb,
+	git_diff_hunk_cb hunk_cb,
+	git_diff_line_cb line_cb,
+	void *payload)
+{
+	int error = 0;
+	uint32_t i, j;
+
+	if (file_cb)
+		error = file_cb(patch->delta, 0, payload);
+
+	if (error)
+		return error;
+
+	if ((patch->delta->flags & GIT_DIFF_FLAG_BINARY) != 0) {
+		if (binary_cb)
+			error = binary_cb(patch->delta, &patch->binary, payload);
+
+		return error;
+	}
+
+	if (!hunk_cb && !line_cb)
+		return error;
+
+	for (i = 0; !error && i < git_array_size(patch->hunks); ++i) {
+		git_patch_hunk *h = git_array_get(patch->hunks, i);
+
+		if (hunk_cb)
+			error = hunk_cb(patch->delta, &h->hunk, payload);
+
+		if (!line_cb)
+			continue;
+
+		for (j = 0; !error && j < h->line_count; ++j) {
+			git_diff_line *l =
+				git_array_get(patch->lines, h->line_start + j);
+
+			error = line_cb(patch->delta, &h->hunk, l, payload);
+		}
+	}
+
+	return error;
+}
+
+size_t git_patch_size(
+	git_patch *patch,
+	int include_context,
+	int include_hunk_headers,
+	int include_file_headers)
+{
+	size_t out;
+
+	assert(patch);
+
+	out = patch->content_size;
+
+	if (!include_context)
+		out -= patch->context_size;
+
+	if (include_hunk_headers)
+		out += patch->header_size;
+
+	if (include_file_headers) {
+		git_buf file_header = GIT_BUF_INIT;
+
+		if (git_diff_delta__format_file_header(
+			&file_header, patch->delta, NULL, NULL, 0) < 0)
+			giterr_clear();
+		else
+			out += git_buf_len(&file_header);
+
+		git_buf_free(&file_header);
+	}
+
+	return out;
+}
+
+int git_patch_line_stats(
+	size_t *total_ctxt,
+	size_t *total_adds,
+	size_t *total_dels,
+	const git_patch *patch)
+{
+	size_t totals[3], idx;
+
+	memset(totals, 0, sizeof(totals));
+
+	for (idx = 0; idx < git_array_size(patch->lines); ++idx) {
+		git_diff_line *line = git_array_get(patch->lines, idx);
+		if (!line)
+			continue;
+
+		switch (line->origin) {
+		case GIT_DIFF_LINE_CONTEXT:  totals[0]++; break;
+		case GIT_DIFF_LINE_ADDITION: totals[1]++; break;
+		case GIT_DIFF_LINE_DELETION: totals[2]++; break;
+		default:
+			/* diff --stat and --numstat don't count EOFNL marks because
+			* they will always be paired with a ADDITION or DELETION line.
+			*/
+			break;
+		}
+	}
+
+	if (total_ctxt)
+		*total_ctxt = totals[0];
+	if (total_adds)
+		*total_adds = totals[1];
+	if (total_dels)
+		*total_dels = totals[2];
+
+	return 0;
+}
+
+const git_diff_delta *git_patch_get_delta(const git_patch *patch)
+{
+	assert(patch);
+	return patch->delta;
+}
+
+size_t git_patch_num_hunks(const git_patch *patch)
+{
+	assert(patch);
+	return git_array_size(patch->hunks);
+}
+
+static int patch_error_outofrange(const char *thing)
+{
+	giterr_set(GITERR_INVALID, "patch %s index out of range", thing);
+	return GIT_ENOTFOUND;
+}
+
+int git_patch_get_hunk(
+	const git_diff_hunk **out,
+	size_t *lines_in_hunk,
+	git_patch *patch,
+	size_t hunk_idx)
+{
+	git_patch_hunk *hunk;
+	assert(patch);
+
+	hunk = git_array_get(patch->hunks, hunk_idx);
+
+	if (!hunk) {
+		if (out) *out = NULL;
+		if (lines_in_hunk) *lines_in_hunk = 0;
+		return patch_error_outofrange("hunk");
+	}
+
+	if (out) *out = &hunk->hunk;
+	if (lines_in_hunk) *lines_in_hunk = hunk->line_count;
+	return 0;
+}
+
+int git_patch_num_lines_in_hunk(const git_patch *patch, size_t hunk_idx)
+{
+	git_patch_hunk *hunk;
+	assert(patch);
+
+	if (!(hunk = git_array_get(patch->hunks, hunk_idx)))
+		return patch_error_outofrange("hunk");
+	return (int)hunk->line_count;
+}
+
+int git_patch_get_line_in_hunk(
+	const git_diff_line **out,
+	git_patch *patch,
+	size_t hunk_idx,
+	size_t line_of_hunk)
+{
+	git_patch_hunk *hunk;
+	git_diff_line *line;
+
+	assert(patch);
+
+	if (!(hunk = git_array_get(patch->hunks, hunk_idx))) {
+		if (out) *out = NULL;
+		return patch_error_outofrange("hunk");
+	}
+
+	if (line_of_hunk >= hunk->line_count ||
+		!(line = git_array_get(
+			patch->lines, hunk->line_start + line_of_hunk))) {
+		if (out) *out = NULL;
+		return patch_error_outofrange("line");
+	}
+
+	if (out) *out = line;
+	return 0;
+}
+
+int git_patch_from_diff(git_patch **out, git_diff *diff, size_t idx)
+{
+	assert(out && diff && diff->patch_fn);
+	return diff->patch_fn(out, diff, idx);
+}
+
+static void git_patch__free(git_patch *patch)
+{
+	if (patch->free_fn)
+		patch->free_fn(patch);
+}
+
+void git_patch_free(git_patch *patch)
+{
+	if (patch)
+		GIT_REFCOUNT_DEC(patch, git_patch__free);
+}

vendor/libgit2-sys/libgit2/src/patch.h

diff --git a/vendor/libgit2-sys/libgit2/src/patch.h b/vendor/libgit2-sys/libgit2/src/patch.h
new file mode 100644
index 0000000..156d131
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/patch.h
@@ -0,0 +1,68 @@
+/*
+* Copyright (C) the libgit2 contributors. All rights reserved.
+*
+* This file is part of libgit2, distributed under the GNU GPL v2 with
+* a Linking Exception. For full terms see the included COPYING file.
+*/
+#ifndef INCLUDE_patch_h__
+#define INCLUDE_patch_h__
+
+#include "common.h"
+
+#include "git2/patch.h"
+#include "array.h"
+
+/* cached information about a hunk in a patch */
+typedef struct git_patch_hunk {
+	git_diff_hunk hunk;
+	size_t line_start;
+	size_t line_count;
+} git_patch_hunk;
+
+struct git_patch {
+	git_refcount rc;
+
+	git_repository *repo; /* may be null */
+
+	git_diff_options diff_opts;
+
+	git_diff_delta *delta;
+	git_diff_binary binary;
+	git_array_t(git_patch_hunk) hunks;
+	git_array_t(git_diff_line) lines;
+
+	size_t header_size;
+	size_t content_size;
+	size_t context_size;
+
+	void (*free_fn)(git_patch *patch);
+};
+
+extern int git_patch__invoke_callbacks(
+	git_patch *patch,
+	git_diff_file_cb file_cb,
+	git_diff_binary_cb binary_cb,
+	git_diff_hunk_cb hunk_cb,
+	git_diff_line_cb line_cb,
+	void *payload);
+
+extern int git_patch_line_stats(
+	size_t *total_ctxt,
+	size_t *total_adds,
+	size_t *total_dels,
+	const git_patch *patch);
+
+/** Options for parsing patch files. */
+typedef struct {
+	/**
+	 * The length of the prefix (in path segments) for the filenames.
+	 * This prefix will be removed when looking for files.  The default is 1.
+	 */
+	uint32_t prefix_len;
+} git_patch_options;
+
+#define GIT_PATCH_OPTIONS_INIT { 1 }
+
+extern void git_patch_free(git_patch *patch);
+
+#endif

vendor/libgit2-sys/libgit2/src/patch_generate.c

diff --git a/vendor/libgit2-sys/libgit2/src/patch_generate.c b/vendor/libgit2-sys/libgit2/src/patch_generate.c
new file mode 100644
index 0000000..29cda8b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/patch_generate.c
@@ -0,0 +1,901 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "patch_generate.h"
+
+#include "git2/blob.h"
+#include "diff.h"
+#include "diff_generate.h"
+#include "diff_file.h"
+#include "diff_driver.h"
+#include "diff_xdiff.h"
+#include "delta.h"
+#include "zstream.h"
+#include "fileops.h"
+
+static void diff_output_init(
+	git_patch_generated_output *, const git_diff_options *, git_diff_file_cb,
+	git_diff_binary_cb, git_diff_hunk_cb, git_diff_line_cb, void*);
+
+static void diff_output_to_patch(
+	git_patch_generated_output *, git_patch_generated *);
+
+static void patch_generated_free(git_patch *p)
+{
+	git_patch_generated *patch = (git_patch_generated *)p;
+
+	git_array_clear(patch->base.lines);
+	git_array_clear(patch->base.hunks);
+
+	git__free((char *)patch->base.binary.old_file.data);
+	git__free((char *)patch->base.binary.new_file.data);
+
+	git_diff_file_content__clear(&patch->ofile);
+	git_diff_file_content__clear(&patch->nfile);
+
+	git_diff_free(patch->diff); /* decrements refcount */
+	patch->diff = NULL;
+
+	git_pool_clear(&patch->flattened);
+
+	git__free((char *)patch->base.diff_opts.old_prefix);
+	git__free((char *)patch->base.diff_opts.new_prefix);
+
+	if (patch->flags & GIT_PATCH_GENERATED_ALLOCATED)
+		git__free(patch);
+}
+
+static void patch_generated_update_binary(git_patch_generated *patch)
+{
+	if ((patch->base.delta->flags & DIFF_FLAGS_KNOWN_BINARY) != 0)
+		return;
+
+	if ((patch->ofile.file->flags & GIT_DIFF_FLAG_BINARY) != 0 ||
+		(patch->nfile.file->flags & GIT_DIFF_FLAG_BINARY) != 0)
+		patch->base.delta->flags |= GIT_DIFF_FLAG_BINARY;
+
+	else if (patch->ofile.file->size > GIT_XDIFF_MAX_SIZE ||
+		patch->nfile.file->size > GIT_XDIFF_MAX_SIZE)
+		patch->base.delta->flags |= GIT_DIFF_FLAG_BINARY;
+
+	else if ((patch->ofile.file->flags & DIFF_FLAGS_NOT_BINARY) != 0 &&
+		(patch->nfile.file->flags & DIFF_FLAGS_NOT_BINARY) != 0)
+		patch->base.delta->flags |= GIT_DIFF_FLAG_NOT_BINARY;
+}
+
+static void patch_generated_init_common(git_patch_generated *patch)
+{
+	patch->base.free_fn = patch_generated_free;
+
+	patch_generated_update_binary(patch);
+
+	patch->flags |= GIT_PATCH_GENERATED_INITIALIZED;
+
+	if (patch->diff)
+		git_diff_addref(patch->diff);
+}
+
+static int patch_generated_normalize_options(
+	git_diff_options *out,
+	const git_diff_options *opts)
+{
+	if (opts) {
+		GITERR_CHECK_VERSION(opts, GIT_DIFF_OPTIONS_VERSION, "git_diff_options");
+		memcpy(out, opts, sizeof(git_diff_options));
+	} else {
+		git_diff_options default_opts = GIT_DIFF_OPTIONS_INIT;
+		memcpy(out, &default_opts, sizeof(git_diff_options));
+	}
+
+	out->old_prefix = opts && opts->old_prefix ?
+		git__strdup(opts->old_prefix) :
+		git__strdup(DIFF_OLD_PREFIX_DEFAULT);
+
+	out->new_prefix = opts && opts->new_prefix ?
+		git__strdup(opts->new_prefix) :
+		git__strdup(DIFF_NEW_PREFIX_DEFAULT);
+
+	GITERR_CHECK_ALLOC(out->old_prefix);
+	GITERR_CHECK_ALLOC(out->new_prefix);
+
+	return 0;
+}
+
+static int patch_generated_init(
+	git_patch_generated *patch, git_diff *diff, size_t delta_index)
+{
+	int error = 0;
+
+	memset(patch, 0, sizeof(*patch));
+
+	patch->diff = diff;
+	patch->base.repo = diff->repo;
+	patch->base.delta = git_vector_get(&diff->deltas, delta_index);
+	patch->delta_index = delta_index;
+
+	if ((error = patch_generated_normalize_options(
+			&patch->base.diff_opts, &diff->opts)) < 0 ||
+		(error = git_diff_file_content__init_from_diff(
+			&patch->ofile, diff, patch->base.delta, true)) < 0 ||
+		(error = git_diff_file_content__init_from_diff(
+			&patch->nfile, diff, patch->base.delta, false)) < 0)
+		return error;
+
+	patch_generated_init_common(patch);
+
+	return 0;
+}
+
+static int patch_generated_alloc_from_diff(
+	git_patch_generated **out, git_diff *diff, size_t delta_index)
+{
+	int error;
+	git_patch_generated *patch = git__calloc(1, sizeof(git_patch_generated));
+	GITERR_CHECK_ALLOC(patch);
+
+	if (!(error = patch_generated_init(patch, diff, delta_index))) {
+		patch->flags |= GIT_PATCH_GENERATED_ALLOCATED;
+		GIT_REFCOUNT_INC(&patch->base);
+	} else {
+		git__free(patch);
+		patch = NULL;
+	}
+
+	*out = patch;
+	return error;
+}
+
+GIT_INLINE(bool) should_skip_binary(git_patch_generated *patch, git_diff_file *file)
+{
+	if ((patch->base.diff_opts.flags & GIT_DIFF_SHOW_BINARY) != 0)
+		return false;
+
+	return (file->flags & GIT_DIFF_FLAG_BINARY) != 0;
+}
+
+static bool patch_generated_diffable(git_patch_generated *patch)
+{
+	size_t olen, nlen;
+
+	if (patch->base.delta->status == GIT_DELTA_UNMODIFIED)
+		return false;
+
+	/* if we've determined this to be binary (and we are not showing binary
+	 * data) then we have skipped loading the map data.  instead, query the
+	 * file data itself.
+	 */
+	if ((patch->base.delta->flags & GIT_DIFF_FLAG_BINARY) != 0 &&
+		(patch->base.diff_opts.flags & GIT_DIFF_SHOW_BINARY) == 0) {
+		olen = (size_t)patch->ofile.file->size;
+		nlen = (size_t)patch->nfile.file->size;
+	} else {
+		olen = patch->ofile.map.len;
+		nlen = patch->nfile.map.len;
+	}
+
+	/* if both sides are empty, files are identical */
+	if (!olen && !nlen)
+		return false;
+
+	/* otherwise, check the file sizes and the oid */
+	return (olen != nlen ||
+		!git_oid_equal(&patch->ofile.file->id, &patch->nfile.file->id));
+}
+
+static int patch_generated_load(git_patch_generated *patch, git_patch_generated_output *output)
+{
+	int error = 0;
+	bool incomplete_data;
+
+	if ((patch->flags & GIT_PATCH_GENERATED_LOADED) != 0)
+		return 0;
+
+	/* if no hunk and data callbacks and user doesn't care if data looks
+	 * binary, then there is no need to actually load the data
+	 */
+	if ((patch->ofile.opts_flags & GIT_DIFF_SKIP_BINARY_CHECK) != 0 &&
+		output && !output->binary_cb && !output->hunk_cb && !output->data_cb)
+		return 0;
+
+	incomplete_data =
+		(((patch->ofile.flags & GIT_DIFF_FLAG__NO_DATA) != 0 ||
+		  (patch->ofile.file->flags & GIT_DIFF_FLAG_VALID_ID) != 0) &&
+		 ((patch->nfile.flags & GIT_DIFF_FLAG__NO_DATA) != 0 ||
+		  (patch->nfile.file->flags & GIT_DIFF_FLAG_VALID_ID) != 0));
+
+	if ((error = git_diff_file_content__load(
+			&patch->ofile, &patch->base.diff_opts)) < 0 ||
+		should_skip_binary(patch, patch->ofile.file))
+		goto cleanup;
+	if ((error = git_diff_file_content__load(
+			&patch->nfile, &patch->base.diff_opts)) < 0 ||
+		should_skip_binary(patch, patch->nfile.file))
+		goto cleanup;
+
+	/* if previously missing an oid, and now that we have it the two sides
+	 * are the same (and not submodules), update MODIFIED -> UNMODIFIED
+	 */
+	if (incomplete_data &&
+		patch->ofile.file->mode == patch->nfile.file->mode &&
+		patch->ofile.file->mode != GIT_FILEMODE_COMMIT &&
+		git_oid_equal(&patch->ofile.file->id, &patch->nfile.file->id) &&
+		patch->base.delta->status == GIT_DELTA_MODIFIED) /* not RENAMED/COPIED! */
+		patch->base.delta->status = GIT_DELTA_UNMODIFIED;
+
+cleanup:
+	patch_generated_update_binary(patch);
+
+	if (!error) {
+		if (patch_generated_diffable(patch))
+			patch->flags |= GIT_PATCH_GENERATED_DIFFABLE;
+
+		patch->flags |= GIT_PATCH_GENERATED_LOADED;
+	}
+
+	return error;
+}
+
+static int patch_generated_invoke_file_callback(
+	git_patch_generated *patch, git_patch_generated_output *output)
+{
+	float progress = patch->diff ?
+		((float)patch->delta_index / patch->diff->deltas.length) : 1.0f;
+
+	if (!output->file_cb)
+		return 0;
+
+	return giterr_set_after_callback_function(
+		output->file_cb(patch->base.delta, progress, output->payload),
+		"git_patch");
+}
+
+static int create_binary(
+	git_diff_binary_t *out_type,
+	char **out_data,
+	size_t *out_datalen,
+	size_t *out_inflatedlen,
+	const char *a_data,
+	size_t a_datalen,
+	const char *b_data,
+	size_t b_datalen)
+{
+	git_buf deflate = GIT_BUF_INIT, delta = GIT_BUF_INIT;
+	size_t delta_data_len = 0;
+	int error;
+
+	/* The git_delta function accepts unsigned long only */
+	if (!git__is_ulong(a_datalen) || !git__is_ulong(b_datalen))
+		return GIT_EBUFS;
+
+	if ((error = git_zstream_deflatebuf(&deflate, b_data, b_datalen)) < 0)
+		goto done;
+
+	/* The git_delta function accepts unsigned long only */
+	if (!git__is_ulong(deflate.size)) {
+		error = GIT_EBUFS;
+		goto done;
+	}
+
+	if (a_datalen && b_datalen) {
+		void *delta_data;
+
+		error = git_delta(&delta_data, &delta_data_len,
+			a_data, a_datalen,
+			b_data, b_datalen,
+			deflate.size);
+
+		if (error == 0) {
+			error = git_zstream_deflatebuf(
+				&delta, delta_data, delta_data_len);
+
+			git__free(delta_data);
+		} else if (error == GIT_EBUFS) {
+			error = 0;
+		}
+
+		if (error < 0)
+			goto done;
+	}
+
+	if (delta.size && delta.size < deflate.size) {
+		*out_type = GIT_DIFF_BINARY_DELTA;
+		*out_datalen = delta.size;
+		*out_data = git_buf_detach(&delta);
+		*out_inflatedlen = delta_data_len;
+	} else {
+		*out_type = GIT_DIFF_BINARY_LITERAL;
+		*out_datalen = deflate.size;
+		*out_data = git_buf_detach(&deflate);
+		*out_inflatedlen = b_datalen;
+	}
+
+done:
+	git_buf_free(&deflate);
+	git_buf_free(&delta);
+
+	return error;
+}
+
+static int diff_binary(git_patch_generated_output *output, git_patch_generated *patch)
+{
+	git_diff_binary binary = {0};
+	const char *old_data = patch->ofile.map.data;
+	const char *new_data = patch->nfile.map.data;
+	size_t old_len = patch->ofile.map.len,
+		new_len = patch->nfile.map.len;
+	int error;
+
+	/* Only load contents if the user actually wants to diff
+	 * binary files. */
+	if (patch->base.diff_opts.flags & GIT_DIFF_SHOW_BINARY) {
+		binary.contains_data = 1;
+
+		/* Create the old->new delta (as the "new" side of the patch),
+		 * and the new->old delta (as the "old" side)
+		 */
+		if ((error = create_binary(&binary.old_file.type,
+				(char **)&binary.old_file.data,
+				&binary.old_file.datalen,
+				&binary.old_file.inflatedlen,
+				new_data, new_len, old_data, old_len)) < 0 ||
+			(error = create_binary(&binary.new_file.type,
+				(char **)&binary.new_file.data,
+				&binary.new_file.datalen,
+				&binary.new_file.inflatedlen,
+				old_data, old_len, new_data, new_len)) < 0)
+			return error;
+	}
+
+	error = giterr_set_after_callback_function(
+		output->binary_cb(patch->base.delta, &binary, output->payload),
+		"git_patch");
+
+	git__free((char *) binary.old_file.data);
+	git__free((char *) binary.new_file.data);
+
+	return error;
+}
+
+static int patch_generated_create(
+	git_patch_generated *patch,
+	git_patch_generated_output *output)
+{
+	int error = 0;
+
+	if ((patch->flags & GIT_PATCH_GENERATED_DIFFED) != 0)
+		return 0;
+
+	/* if we are not looking at the binary or text data, don't do the diff */
+	if (!output->binary_cb && !output->hunk_cb && !output->data_cb)
+		return 0;
+
+	if ((patch->flags & GIT_PATCH_GENERATED_LOADED) == 0 &&
+		(error = patch_generated_load(patch, output)) < 0)
+		return error;
+
+	if ((patch->flags & GIT_PATCH_GENERATED_DIFFABLE) == 0)
+		return 0;
+
+	if ((patch->base.delta->flags & GIT_DIFF_FLAG_BINARY) != 0) {
+		if (output->binary_cb)
+			error = diff_binary(output, patch);
+	}
+	else {
+		if (output->diff_cb)
+			error = output->diff_cb(output, patch);
+	}
+
+	patch->flags |= GIT_PATCH_GENERATED_DIFFED;
+	return error;
+}
+
+static int diff_required(git_diff *diff, const char *action)
+{
+	if (diff)
+		return 0;
+	giterr_set(GITERR_INVALID, "must provide valid diff to %s", action);
+	return -1;
+}
+
+typedef struct {
+	git_patch_generated patch;
+	git_diff_delta delta;
+	char paths[GIT_FLEX_ARRAY];
+} patch_generated_with_delta;
+
+static int diff_single_generate(patch_generated_with_delta *pd, git_xdiff_output *xo)
+{
+	int error = 0;
+	git_patch_generated *patch = &pd->patch;
+	bool has_old = ((patch->ofile.flags & GIT_DIFF_FLAG__NO_DATA) == 0);
+	bool has_new = ((patch->nfile.flags & GIT_DIFF_FLAG__NO_DATA) == 0);
+
+	pd->delta.status = has_new ?
+		(has_old ? GIT_DELTA_MODIFIED : GIT_DELTA_ADDED) :
+		(has_old ? GIT_DELTA_DELETED : GIT_DELTA_UNTRACKED);
+
+	if (git_oid_equal(&patch->nfile.file->id, &patch->ofile.file->id))
+		pd->delta.status = GIT_DELTA_UNMODIFIED;
+
+	patch->base.delta = &pd->delta;
+
+	patch_generated_init_common(patch);
+
+	if (pd->delta.status == GIT_DELTA_UNMODIFIED &&
+		!(patch->ofile.opts_flags & GIT_DIFF_INCLUDE_UNMODIFIED)) {
+
+		/* Even empty patches are flagged as binary, and even though
+		 * there's no difference, we flag this as "containing data"
+		 * (the data is known to be empty, as opposed to wholly unknown).
+		 */
+		if (patch->base.diff_opts.flags & GIT_DIFF_SHOW_BINARY)
+			patch->base.binary.contains_data = 1;
+
+		return error;
+	}
+
+	error = patch_generated_invoke_file_callback(patch, (git_patch_generated_output *)xo);
+
+	if (!error)
+		error = patch_generated_create(patch, (git_patch_generated_output *)xo);
+
+	return error;
+}
+
+static int patch_generated_from_sources(
+	patch_generated_with_delta *pd,
+	git_xdiff_output *xo,
+	git_diff_file_content_src *oldsrc,
+	git_diff_file_content_src *newsrc,
+	const git_diff_options *opts)
+{
+	int error = 0;
+	git_repository *repo =
+		oldsrc->blob ? git_blob_owner(oldsrc->blob) :
+		newsrc->blob ? git_blob_owner(newsrc->blob) : NULL;
+	git_diff_file *lfile = &pd->delta.old_file, *rfile = &pd->delta.new_file;
+	git_diff_file_content *ldata = &pd->patch.ofile, *rdata = &pd->patch.nfile;
+
+	if ((error = patch_generated_normalize_options(&pd->patch.base.diff_opts, opts)) < 0)
+		return error;
+
+	if (opts && (opts->flags & GIT_DIFF_REVERSE) != 0) {
+		void *tmp = lfile; lfile = rfile; rfile = tmp;
+		tmp = ldata; ldata = rdata; rdata = tmp;
+	}
+
+	pd->patch.base.delta = &pd->delta;
+
+	if (!oldsrc->as_path) {
+		if (newsrc->as_path)
+			oldsrc->as_path = newsrc->as_path;
+		else
+			oldsrc->as_path = newsrc->as_path = "file";
+	}
+	else if (!newsrc->as_path)
+		newsrc->as_path = oldsrc->as_path;
+
+	lfile->path = oldsrc->as_path;
+	rfile->path = newsrc->as_path;
+
+	if ((error = git_diff_file_content__init_from_src(
+			ldata, repo, opts, oldsrc, lfile)) < 0 ||
+		(error = git_diff_file_content__init_from_src(
+			rdata, repo, opts, newsrc, rfile)) < 0)
+		return error;
+
+	return diff_single_generate(pd, xo);
+}
+
+static int patch_generated_with_delta_alloc(
+	patch_generated_with_delta **out,
+	const char **old_path,
+	const char **new_path)
+{
+	patch_generated_with_delta *pd;
+	size_t old_len = *old_path ? strlen(*old_path) : 0;
+	size_t new_len = *new_path ? strlen(*new_path) : 0;
+	size_t alloc_len;
+
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, sizeof(*pd), old_len);
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, new_len);
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, 2);
+
+	*out = pd = git__calloc(1, alloc_len);
+	GITERR_CHECK_ALLOC(pd);
+
+	pd->patch.flags = GIT_PATCH_GENERATED_ALLOCATED;
+
+	if (*old_path) {
+		memcpy(&pd->paths[0], *old_path, old_len);
+		*old_path = &pd->paths[0];
+	} else if (*new_path)
+		*old_path = &pd->paths[old_len + 1];
+
+	if (*new_path) {
+		memcpy(&pd->paths[old_len + 1], *new_path, new_len);
+		*new_path = &pd->paths[old_len + 1];
+	} else if (*old_path)
+		*new_path = &pd->paths[0];
+
+	return 0;
+}
+
+static int diff_from_sources(
+	git_diff_file_content_src *oldsrc,
+	git_diff_file_content_src *newsrc,
+	const git_diff_options *opts,
+	git_diff_file_cb file_cb,
+	git_diff_binary_cb binary_cb,
+	git_diff_hunk_cb hunk_cb,
+	git_diff_line_cb data_cb,
+	void *payload)
+{
+	int error = 0;
+	patch_generated_with_delta pd;
+	git_xdiff_output xo;
+
+	memset(&xo, 0, sizeof(xo));
+	diff_output_init(
+		&xo.output, opts, file_cb, binary_cb, hunk_cb, data_cb, payload);
+	git_xdiff_init(&xo, opts);
+
+	memset(&pd, 0, sizeof(pd));
+
+	error = patch_generated_from_sources(&pd, &xo, oldsrc, newsrc, opts);
+
+	git_patch_free(&pd.patch.base);
+
+	return error;
+}
+
+static int patch_from_sources(
+	git_patch **out,
+	git_diff_file_content_src *oldsrc,
+	git_diff_file_content_src *newsrc,
+	const git_diff_options *opts)
+{
+	int error = 0;
+	patch_generated_with_delta *pd;
+	git_xdiff_output xo;
+
+	assert(out);
+	*out = NULL;
+
+	if ((error = patch_generated_with_delta_alloc(
+			&pd, &oldsrc->as_path, &newsrc->as_path)) < 0)
+		return error;
+
+	memset(&xo, 0, sizeof(xo));
+	diff_output_to_patch(&xo.output, &pd->patch);
+	git_xdiff_init(&xo, opts);
+
+	if (!(error = patch_generated_from_sources(pd, &xo, oldsrc, newsrc, opts)))
+		*out = (git_patch *)pd;
+	else
+		git_patch_free((git_patch *)pd);
+
+	return error;
+}
+
+int git_diff_blobs(
+	const git_blob *old_blob,
+	const char *old_path,
+	const git_blob *new_blob,
+	const char *new_path,
+	const git_diff_options *opts,
+	git_diff_file_cb file_cb,
+	git_diff_binary_cb binary_cb,
+	git_diff_hunk_cb hunk_cb,
+	git_diff_line_cb data_cb,
+	void *payload)
+{
+	git_diff_file_content_src osrc =
+		GIT_DIFF_FILE_CONTENT_SRC__BLOB(old_blob, old_path);
+	git_diff_file_content_src nsrc =
+		GIT_DIFF_FILE_CONTENT_SRC__BLOB(new_blob, new_path);
+	return diff_from_sources(
+		&osrc, &nsrc, opts, file_cb, binary_cb, hunk_cb, data_cb, payload);
+}
+
+int git_patch_from_blobs(
+	git_patch **out,
+	const git_blob *old_blob,
+	const char *old_path,
+	const git_blob *new_blob,
+	const char *new_path,
+	const git_diff_options *opts)
+{
+	git_diff_file_content_src osrc =
+		GIT_DIFF_FILE_CONTENT_SRC__BLOB(old_blob, old_path);
+	git_diff_file_content_src nsrc =
+		GIT_DIFF_FILE_CONTENT_SRC__BLOB(new_blob, new_path);
+	return patch_from_sources(out, &osrc, &nsrc, opts);
+}
+
+int git_diff_blob_to_buffer(
+	const git_blob *old_blob,
+	const char *old_path,
+	const char *buf,
+	size_t buflen,
+	const char *buf_path,
+	const git_diff_options *opts,
+	git_diff_file_cb file_cb,
+	git_diff_binary_cb binary_cb,
+	git_diff_hunk_cb hunk_cb,
+	git_diff_line_cb data_cb,
+	void *payload)
+{
+	git_diff_file_content_src osrc =
+		GIT_DIFF_FILE_CONTENT_SRC__BLOB(old_blob, old_path);
+	git_diff_file_content_src nsrc =
+		GIT_DIFF_FILE_CONTENT_SRC__BUF(buf, buflen, buf_path);
+	return diff_from_sources(
+		&osrc, &nsrc, opts, file_cb, binary_cb, hunk_cb, data_cb, payload);
+}
+
+int git_patch_from_blob_and_buffer(
+	git_patch **out,
+	const git_blob *old_blob,
+	const char *old_path,
+	const void *buf,
+	size_t buflen,
+	const char *buf_path,
+	const git_diff_options *opts)
+{
+	git_diff_file_content_src osrc =
+		GIT_DIFF_FILE_CONTENT_SRC__BLOB(old_blob, old_path);
+	git_diff_file_content_src nsrc =
+		GIT_DIFF_FILE_CONTENT_SRC__BUF(buf, buflen, buf_path);
+	return patch_from_sources(out, &osrc, &nsrc, opts);
+}
+
+int git_diff_buffers(
+	const void *old_buf,
+	size_t old_len,
+	const char *old_path,
+	const void *new_buf,
+	size_t new_len,
+	const char *new_path,
+	const git_diff_options *opts,
+	git_diff_file_cb file_cb,
+	git_diff_binary_cb binary_cb,
+	git_diff_hunk_cb hunk_cb,
+	git_diff_line_cb data_cb,
+	void *payload)
+{
+	git_diff_file_content_src osrc =
+		GIT_DIFF_FILE_CONTENT_SRC__BUF(old_buf, old_len, old_path);
+	git_diff_file_content_src nsrc =
+		GIT_DIFF_FILE_CONTENT_SRC__BUF(new_buf, new_len, new_path);
+	return diff_from_sources(
+		&osrc, &nsrc, opts, file_cb, binary_cb, hunk_cb, data_cb, payload);
+}
+
+int git_patch_from_buffers(
+	git_patch **out,
+	const void *old_buf,
+	size_t old_len,
+	const char *old_path,
+	const void *new_buf,
+	size_t new_len,
+	const char *new_path,
+	const git_diff_options *opts)
+{
+	git_diff_file_content_src osrc =
+		GIT_DIFF_FILE_CONTENT_SRC__BUF(old_buf, old_len, old_path);
+	git_diff_file_content_src nsrc =
+		GIT_DIFF_FILE_CONTENT_SRC__BUF(new_buf, new_len, new_path);
+	return patch_from_sources(out, &osrc, &nsrc, opts);
+}
+
+int git_patch_generated_from_diff(
+	git_patch **patch_ptr, git_diff *diff, size_t idx)
+{
+	int error = 0;
+	git_xdiff_output xo;
+	git_diff_delta *delta = NULL;
+	git_patch_generated *patch = NULL;
+
+	if (patch_ptr) *patch_ptr = NULL;
+
+	if (diff_required(diff, "git_patch_from_diff") < 0)
+		return -1;
+
+	delta = git_vector_get(&diff->deltas, idx);
+	if (!delta) {
+		giterr_set(GITERR_INVALID, "index out of range for delta in diff");
+		return GIT_ENOTFOUND;
+	}
+
+	if (git_diff_delta__should_skip(&diff->opts, delta))
+		return 0;
+
+	/* don't load the patch data unless we need it for binary check */
+	if (!patch_ptr &&
+		((delta->flags & DIFF_FLAGS_KNOWN_BINARY) != 0 ||
+		 (diff->opts.flags & GIT_DIFF_SKIP_BINARY_CHECK) != 0))
+		return 0;
+
+	if ((error = patch_generated_alloc_from_diff(&patch, diff, idx)) < 0)
+		return error;
+
+	memset(&xo, 0, sizeof(xo));
+	diff_output_to_patch(&xo.output, patch);
+	git_xdiff_init(&xo, &diff->opts);
+
+	error = patch_generated_invoke_file_callback(patch, &xo.output);
+
+	if (!error)
+		error = patch_generated_create(patch, &xo.output);
+
+	if (!error) {
+		/* TODO: if cumulative diff size is < 0.5 total size, flatten patch */
+		/* TODO: and unload the file content */
+	}
+
+	if (error || !patch_ptr)
+		git_patch_free(&patch->base);
+	else
+		*patch_ptr = &patch->base;
+
+	return error;
+}
+
+git_diff_driver *git_patch_generated_driver(git_patch_generated *patch)
+{
+	/* ofile driver is representative for whole patch */
+	return patch->ofile.driver;
+}
+
+void git_patch_generated_old_data(
+	char **ptr, size_t *len, git_patch_generated *patch)
+{
+	*ptr = patch->ofile.map.data;
+	*len = patch->ofile.map.len;
+}
+
+void git_patch_generated_new_data(
+	char **ptr, size_t *len, git_patch_generated *patch)
+{
+	*ptr = patch->nfile.map.data;
+	*len = patch->nfile.map.len;
+}
+
+static int patch_generated_file_cb(
+	const git_diff_delta *delta,
+	float progress,
+	void *payload)
+{
+	GIT_UNUSED(delta); GIT_UNUSED(progress); GIT_UNUSED(payload);
+	return 0;
+}
+
+static int patch_generated_binary_cb(
+	const git_diff_delta *delta,
+	const git_diff_binary *binary,
+	void *payload)
+{
+	git_patch *patch = payload;
+
+	GIT_UNUSED(delta);
+
+	memcpy(&patch->binary, binary, sizeof(git_diff_binary));
+
+	if (binary->old_file.data) {
+		patch->binary.old_file.data = git__malloc(binary->old_file.datalen);
+		GITERR_CHECK_ALLOC(patch->binary.old_file.data);
+
+		memcpy((char *)patch->binary.old_file.data,
+			binary->old_file.data, binary->old_file.datalen);
+	}
+
+	if (binary->new_file.data) {
+		patch->binary.new_file.data = git__malloc(binary->new_file.datalen);
+		GITERR_CHECK_ALLOC(patch->binary.new_file.data);
+
+		memcpy((char *)patch->binary.new_file.data,
+			binary->new_file.data, binary->new_file.datalen);
+	}
+
+	return 0;
+}
+
+static int git_patch_hunk_cb(
+	const git_diff_delta *delta,
+	const git_diff_hunk *hunk_,
+	void *payload)
+{
+	git_patch_generated  *patch = payload;
+	git_patch_hunk *hunk;
+
+	GIT_UNUSED(delta);
+
+	hunk = git_array_alloc(patch->base.hunks);
+	GITERR_CHECK_ALLOC(hunk);
+
+	memcpy(&hunk->hunk, hunk_, sizeof(hunk->hunk));
+
+	patch->base.header_size += hunk_->header_len;
+
+	hunk->line_start = git_array_size(patch->base.lines);
+	hunk->line_count = 0;
+
+	return 0;
+}
+
+static int patch_generated_line_cb(
+	const git_diff_delta *delta,
+	const git_diff_hunk *hunk_,
+	const git_diff_line *line_,
+	void *payload)
+{
+	git_patch_generated  *patch = payload;
+	git_patch_hunk *hunk;
+	git_diff_line   *line;
+
+	GIT_UNUSED(delta);
+	GIT_UNUSED(hunk_);
+
+	hunk = git_array_last(patch->base.hunks);
+	assert(hunk); /* programmer error if no hunk is available */
+
+	line = git_array_alloc(patch->base.lines);
+	GITERR_CHECK_ALLOC(line);
+
+	memcpy(line, line_, sizeof(*line));
+
+	/* do some bookkeeping so we can provide old/new line numbers */
+
+	patch->base.content_size += line->content_len;
+
+	if (line->origin == GIT_DIFF_LINE_ADDITION ||
+		line->origin == GIT_DIFF_LINE_DELETION)
+		patch->base.content_size += 1;
+	else if (line->origin == GIT_DIFF_LINE_CONTEXT) {
+		patch->base.content_size += 1;
+		patch->base.context_size += line->content_len + 1;
+	} else if (line->origin == GIT_DIFF_LINE_CONTEXT_EOFNL)
+		patch->base.context_size += line->content_len;
+
+	hunk->line_count++;
+
+	return 0;
+}
+
+static void diff_output_init(
+	git_patch_generated_output *out,
+	const git_diff_options *opts,
+	git_diff_file_cb file_cb,
+	git_diff_binary_cb binary_cb,
+	git_diff_hunk_cb hunk_cb,
+	git_diff_line_cb data_cb,
+	void *payload)
+{
+	GIT_UNUSED(opts);
+
+	memset(out, 0, sizeof(*out));
+
+	out->file_cb = file_cb;
+	out->binary_cb = binary_cb;
+	out->hunk_cb = hunk_cb;
+	out->data_cb = data_cb;
+	out->payload = payload;
+}
+
+static void diff_output_to_patch(
+	git_patch_generated_output *out, git_patch_generated *patch)
+{
+	diff_output_init(
+		out,
+		NULL,
+		patch_generated_file_cb,
+		patch_generated_binary_cb,
+		git_patch_hunk_cb,
+		patch_generated_line_cb,
+		patch);
+}

vendor/libgit2-sys/libgit2/src/patch_generate.h

diff --git a/vendor/libgit2-sys/libgit2/src/patch_generate.h b/vendor/libgit2-sys/libgit2/src/patch_generate.h
new file mode 100644
index 0000000..20f78cb
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/patch_generate.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_patch_generate_h__
+#define INCLUDE_patch_generate_h__
+
+#include "common.h"
+
+#include "diff.h"
+#include "diff_file.h"
+#include "patch.h"
+
+enum {
+	GIT_PATCH_GENERATED_ALLOCATED = (1 << 0),
+	GIT_PATCH_GENERATED_INITIALIZED = (1 << 1),
+	GIT_PATCH_GENERATED_LOADED = (1 << 2),
+	/* the two sides are different */
+	GIT_PATCH_GENERATED_DIFFABLE = (1 << 3),
+	/* the difference between the two sides has been computed */
+	GIT_PATCH_GENERATED_DIFFED = (1 << 4),
+	GIT_PATCH_GENERATED_FLATTENED = (1 << 5),
+};
+
+struct git_patch_generated {
+	struct git_patch base;
+
+	git_diff *diff; /* for refcount purposes, maybe NULL for blob diffs */
+	size_t delta_index;
+	git_diff_file_content ofile;
+	git_diff_file_content nfile;
+	uint32_t flags;
+	git_pool flattened;
+};
+
+typedef struct git_patch_generated git_patch_generated;
+
+extern git_diff_driver *git_patch_generated_driver(git_patch_generated *);
+
+extern void git_patch_generated_old_data(
+	char **, size_t *, git_patch_generated *);
+extern void git_patch_generated_new_data(
+	char **, size_t *, git_patch_generated *);
+extern int git_patch_generated_from_diff(
+	git_patch **, git_diff *, size_t);
+
+typedef struct git_patch_generated_output git_patch_generated_output;
+
+struct git_patch_generated_output {
+	/* these callbacks are issued with the diff data */
+	git_diff_file_cb file_cb;
+	git_diff_binary_cb binary_cb;
+	git_diff_hunk_cb hunk_cb;
+	git_diff_line_cb data_cb;
+	void *payload;
+
+	/* this records the actual error in cases where it may be obscured */
+	int error;
+
+	/* this callback is used to do the diff and drive the other callbacks.
+	 * see diff_xdiff.h for how to use this in practice for now.
+	 */
+	int (*diff_cb)(git_patch_generated_output *output,
+		git_patch_generated *patch);
+};
+
+#endif

vendor/libgit2-sys/libgit2/src/patch_parse.c

diff --git a/vendor/libgit2-sys/libgit2/src/patch_parse.c b/vendor/libgit2-sys/libgit2/src/patch_parse.c
new file mode 100644
index 0000000..acdd45e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/patch_parse.c
@@ -0,0 +1,1149 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "patch_parse.h"
+
+#include "git2/patch.h"
+#include "patch.h"
+#include "diff_parse.h"
+#include "path.h"
+
+typedef struct {
+	git_patch base;
+
+	git_patch_parse_ctx *ctx;
+
+	/* the paths from the `diff --git` header, these will be used if this is not
+	 * a rename (and rename paths are specified) or if no `+++`/`---` line specify
+	 * the paths.
+	 */
+	char *header_old_path, *header_new_path;
+
+	/* renamed paths are precise and are not prefixed */
+	char *rename_old_path, *rename_new_path;
+
+	/* the paths given in `---` and `+++` lines */
+	char *old_path, *new_path;
+
+	/* the prefixes from the old/new paths */
+	char *old_prefix, *new_prefix;
+} git_patch_parsed;
+
+static int header_path_len(git_patch_parse_ctx *ctx)
+{
+	bool inquote = 0;
+	bool quoted = git_parse_ctx_contains_s(&ctx->parse_ctx, "\"");
+	size_t len;
+
+	for (len = quoted; len < ctx->parse_ctx.line_len; len++) {
+		if (!quoted && git__isspace(ctx->parse_ctx.line[len]))
+			break;
+		else if (quoted && !inquote && ctx->parse_ctx.line[len] == '"') {
+			len++;
+			break;
+		}
+
+		inquote = (!inquote && ctx->parse_ctx.line[len] == '\\');
+	}
+
+	return len;
+}
+
+static int parse_header_path_buf(git_buf *path, git_patch_parse_ctx *ctx, size_t path_len)
+{
+	int error;
+
+	if ((error = git_buf_put(path, ctx->parse_ctx.line, path_len)) < 0)
+		goto done;
+
+	git_parse_advance_chars(&ctx->parse_ctx, path_len);
+
+	git_buf_rtrim(path);
+
+	if (path->size > 0 && path->ptr[0] == '"')
+		error = git_buf_unquote(path);
+
+	if (error < 0)
+		goto done;
+
+	git_path_squash_slashes(path);
+
+done:
+	return error;
+}
+
+static int parse_header_path(char **out, git_patch_parse_ctx *ctx)
+{
+	git_buf path = GIT_BUF_INIT;
+	int error = parse_header_path_buf(&path, ctx, header_path_len(ctx));
+
+	*out = git_buf_detach(&path);
+
+	return error;
+}
+
+static int parse_header_git_oldpath(
+	git_patch_parsed *patch, git_patch_parse_ctx *ctx)
+{
+	git_buf old_path = GIT_BUF_INIT;
+	int error;
+
+	if ((error = parse_header_path_buf(&old_path, ctx, ctx->parse_ctx.line_len - 1)) <  0)
+		goto out;
+
+	patch->old_path = git_buf_detach(&old_path);
+
+out:
+	git_buf_free(&old_path);
+	return error;
+}
+
+static int parse_header_git_newpath(
+	git_patch_parsed *patch, git_patch_parse_ctx *ctx)
+{
+	git_buf new_path = GIT_BUF_INIT;
+	int error;
+
+	if ((error = parse_header_path_buf(&new_path, ctx, ctx->parse_ctx.line_len - 1)) <  0)
+		goto out;
+
+	patch->new_path = git_buf_detach(&new_path);
+
+out:
+	git_buf_free(&new_path);
+	return error;
+}
+
+static int parse_header_mode(uint16_t *mode, git_patch_parse_ctx *ctx)
+{
+	int64_t m;
+
+	if ((git_parse_advance_digit(&m, &ctx->parse_ctx, 8)) < 0)
+		return git_parse_err("invalid file mode at line %"PRIuZ, ctx->parse_ctx.line_num);
+
+	if (m > UINT16_MAX)
+		return -1;
+
+	*mode = (uint16_t)m;
+
+	return 0;
+}
+
+static int parse_header_oid(
+	git_oid *oid,
+	uint16_t *oid_len,
+	git_patch_parse_ctx *ctx)
+{
+	size_t len;
+
+	for (len = 0; len < ctx->parse_ctx.line_len && len < GIT_OID_HEXSZ; len++) {
+		if (!git__isxdigit(ctx->parse_ctx.line[len]))
+			break;
+	}
+
+	if (len < GIT_OID_MINPREFIXLEN || len > GIT_OID_HEXSZ ||
+		git_oid_fromstrn(oid, ctx->parse_ctx.line, len) < 0)
+		return git_parse_err("invalid hex formatted object id at line %"PRIuZ,
+			ctx->parse_ctx.line_num);
+
+	git_parse_advance_chars(&ctx->parse_ctx, len);
+
+	*oid_len = (uint16_t)len;
+
+	return 0;
+}
+
+static int parse_header_git_index(
+	git_patch_parsed *patch, git_patch_parse_ctx *ctx)
+{
+	char c;
+
+	if (parse_header_oid(&patch->base.delta->old_file.id,
+			&patch->base.delta->old_file.id_abbrev, ctx) < 0 ||
+		git_parse_advance_expected_str(&ctx->parse_ctx, "..") < 0 ||
+		parse_header_oid(&patch->base.delta->new_file.id,
+			&patch->base.delta->new_file.id_abbrev, ctx) < 0)
+		return -1;
+
+	if (git_parse_peek(&c, &ctx->parse_ctx, 0) == 0 && c == ' ') {
+		uint16_t mode;
+
+		git_parse_advance_chars(&ctx->parse_ctx, 1);
+
+		if (parse_header_mode(&mode, ctx) < 0)
+			return -1;
+
+		if (!patch->base.delta->new_file.mode)
+			patch->base.delta->new_file.mode = mode;
+
+		if (!patch->base.delta->old_file.mode)
+			patch->base.delta->old_file.mode = mode;
+	}
+
+	return 0;
+}
+
+static int parse_header_git_oldmode(
+	git_patch_parsed *patch, git_patch_parse_ctx *ctx)
+{
+	return parse_header_mode(&patch->base.delta->old_file.mode, ctx);
+}
+
+static int parse_header_git_newmode(
+	git_patch_parsed *patch, git_patch_parse_ctx *ctx)
+{
+	return parse_header_mode(&patch->base.delta->new_file.mode, ctx);
+}
+
+static int parse_header_git_deletedfilemode(
+	git_patch_parsed *patch,
+	git_patch_parse_ctx *ctx)
+{
+	git__free((char *)patch->base.delta->old_file.path);
+
+	patch->base.delta->old_file.path = NULL;
+	patch->base.delta->status = GIT_DELTA_DELETED;
+	patch->base.delta->nfiles = 1;
+
+	return parse_header_mode(&patch->base.delta->old_file.mode, ctx);
+}
+
+static int parse_header_git_newfilemode(
+	git_patch_parsed *patch,
+	git_patch_parse_ctx *ctx)
+{
+	git__free((char *)patch->base.delta->new_file.path);
+
+	patch->base.delta->new_file.path = NULL;
+	patch->base.delta->status = GIT_DELTA_ADDED;
+	patch->base.delta->nfiles = 1;
+
+	return parse_header_mode(&patch->base.delta->new_file.mode, ctx);
+}
+
+static int parse_header_rename(
+	char **out,
+	git_patch_parse_ctx *ctx)
+{
+	git_buf path = GIT_BUF_INIT;
+
+	if (parse_header_path_buf(&path, ctx, header_path_len(ctx)) < 0)
+		return -1;
+
+	/* Note: the `rename from` and `rename to` lines include the literal
+	 * filename.  They do *not* include the prefix.  (Who needs consistency?)
+	 */
+	*out = git_buf_detach(&path);
+	return 0;
+}
+
+static int parse_header_renamefrom(
+	git_patch_parsed *patch, git_patch_parse_ctx *ctx)
+{
+	patch->base.delta->status = GIT_DELTA_RENAMED;
+	return parse_header_rename(&patch->rename_old_path, ctx);
+}
+
+static int parse_header_renameto(
+	git_patch_parsed *patch, git_patch_parse_ctx *ctx)
+{
+	patch->base.delta->status = GIT_DELTA_RENAMED;
+	return parse_header_rename(&patch->rename_new_path, ctx);
+}
+
+static int parse_header_copyfrom(
+	git_patch_parsed *patch, git_patch_parse_ctx *ctx)
+{
+	patch->base.delta->status = GIT_DELTA_COPIED;
+	return parse_header_rename(&patch->rename_old_path, ctx);
+}
+
+static int parse_header_copyto(
+	git_patch_parsed *patch, git_patch_parse_ctx *ctx)
+{
+	patch->base.delta->status = GIT_DELTA_COPIED;
+	return parse_header_rename(&patch->rename_new_path, ctx);
+}
+
+static int parse_header_percent(uint16_t *out, git_patch_parse_ctx *ctx)
+{
+	int64_t val;
+
+	if (git_parse_advance_digit(&val, &ctx->parse_ctx, 10) < 0)
+		return -1;
+
+	if (git_parse_advance_expected_str(&ctx->parse_ctx, "%") < 0)
+		return -1;
+
+	if (val < 0 || val > 100)
+		return -1;
+
+	*out = val;
+	return 0;
+}
+
+static int parse_header_similarity(
+	git_patch_parsed *patch, git_patch_parse_ctx *ctx)
+{
+	if (parse_header_percent(&patch->base.delta->similarity, ctx) < 0)
+		return git_parse_err("invalid similarity percentage at line %"PRIuZ,
+			ctx->parse_ctx.line_num);
+
+	return 0;
+}
+
+static int parse_header_dissimilarity(
+	git_patch_parsed *patch, git_patch_parse_ctx *ctx)
+{
+	uint16_t dissimilarity;
+
+	if (parse_header_percent(&dissimilarity, ctx) < 0)
+		return git_parse_err("invalid similarity percentage at line %"PRIuZ,
+			ctx->parse_ctx.line_num);
+
+	patch->base.delta->similarity = 100 - dissimilarity;
+
+	return 0;
+}
+
+static int parse_header_start(git_patch_parsed *patch, git_patch_parse_ctx *ctx)
+{
+	if (parse_header_path(&patch->header_old_path, ctx) < 0)
+		return git_parse_err("corrupt old path in git diff header at line %"PRIuZ,
+			ctx->parse_ctx.line_num);
+
+	if (git_parse_advance_ws(&ctx->parse_ctx) < 0 ||
+		parse_header_path(&patch->header_new_path, ctx) < 0)
+		return git_parse_err("corrupt new path in git diff header at line %"PRIuZ,
+			ctx->parse_ctx.line_num);
+
+	/*
+	 * We cannot expect to be able to always parse paths correctly at this
+	 * point. Due to the possibility of unquoted names, whitespaces in
+	 * filenames and custom prefixes we have to allow that, though, and just
+	 * proceeed here. We then hope for the "---" and "+++" lines to fix that
+	 * for us.
+	 */
+	if (!git_parse_ctx_contains(&ctx->parse_ctx, "\n", 1)) {
+		git_parse_advance_chars(&ctx->parse_ctx, ctx->parse_ctx.line_len - 1);
+
+		git__free(patch->header_old_path);
+		patch->header_old_path = NULL;
+		git__free(patch->header_new_path);
+		patch->header_new_path = NULL;
+	}
+
+	return 0;
+}
+
+typedef enum {
+	STATE_START,
+
+	STATE_DIFF,
+	STATE_FILEMODE,
+	STATE_MODE,
+	STATE_INDEX,
+	STATE_PATH,
+
+	STATE_SIMILARITY,
+	STATE_RENAME,
+	STATE_COPY,
+
+	STATE_END,
+} parse_header_state;
+
+typedef struct {
+	const char *str;
+	parse_header_state expected_state;
+	parse_header_state next_state;
+	int(*fn)(git_patch_parsed *, git_patch_parse_ctx *);
+} parse_header_transition;
+
+static const parse_header_transition transitions[] = {
+	/* Start */
+	{ "diff --git "         , STATE_START,      STATE_DIFF,       parse_header_start },
+
+	{ "deleted file mode "  , STATE_DIFF,       STATE_FILEMODE,   parse_header_git_deletedfilemode },
+	{ "new file mode "      , STATE_DIFF,       STATE_FILEMODE,   parse_header_git_newfilemode },
+	{ "old mode "           , STATE_DIFF,       STATE_MODE,       parse_header_git_oldmode },
+	{ "new mode "           , STATE_MODE,       STATE_END,        parse_header_git_newmode },
+
+	{ "index "              , STATE_FILEMODE,   STATE_INDEX,      parse_header_git_index },
+	{ "index "              , STATE_DIFF,       STATE_INDEX,      parse_header_git_index },
+	{ "index "              , STATE_END,        STATE_INDEX,      parse_header_git_index },
+
+	{ "--- "                , STATE_INDEX,      STATE_PATH,       parse_header_git_oldpath },
+	{ "+++ "                , STATE_PATH,       STATE_END,        parse_header_git_newpath },
+	{ "GIT binary patch"    , STATE_INDEX,      STATE_END,        NULL },
+	{ "Binary files "       , STATE_INDEX,      STATE_END,        NULL },
+
+	{ "similarity index "   , STATE_DIFF,       STATE_SIMILARITY, parse_header_similarity },
+	{ "dissimilarity index ", STATE_DIFF,       STATE_SIMILARITY, parse_header_dissimilarity },
+	{ "rename from "        , STATE_SIMILARITY, STATE_RENAME,     parse_header_renamefrom },
+	{ "rename old "         , STATE_SIMILARITY, STATE_RENAME,     parse_header_renamefrom },
+	{ "copy from "          , STATE_SIMILARITY, STATE_COPY,       parse_header_copyfrom },
+	{ "rename to "          , STATE_RENAME,     STATE_END,        parse_header_renameto },
+	{ "rename new "         , STATE_RENAME,     STATE_END,        parse_header_renameto },
+	{ "copy to "            , STATE_COPY,       STATE_END,        parse_header_copyto },
+
+	/* Next patch */
+	{ "diff --git "         , STATE_END,        0,                NULL },
+	{ "@@ -"                , STATE_END,        0,                NULL },
+	{ "-- "                 , STATE_END,        0,                NULL },
+};
+
+static int parse_header_git(
+	git_patch_parsed *patch,
+	git_patch_parse_ctx *ctx)
+{
+	size_t i;
+	int error = 0;
+	parse_header_state state = STATE_START;
+
+	/* Parse remaining header lines */
+	for (; ctx->parse_ctx.remain_len > 0; git_parse_advance_line(&ctx->parse_ctx)) {
+		bool found = false;
+
+		if (ctx->parse_ctx.line_len == 0 || ctx->parse_ctx.line[ctx->parse_ctx.line_len - 1] != '\n')
+			break;
+
+		for (i = 0; i < ARRAY_SIZE(transitions); i++) {
+			const parse_header_transition *transition = &transitions[i];
+			size_t op_len = strlen(transition->str);
+
+			if (transition->expected_state != state ||
+			    git__prefixcmp(ctx->parse_ctx.line, transition->str) != 0)
+				continue;
+
+			state = transition->next_state;
+
+			/* Do not advance if this is the patch separator */
+			if (transition->fn == NULL)
+				goto done;
+
+			git_parse_advance_chars(&ctx->parse_ctx, op_len);
+
+			if ((error = transition->fn(patch, ctx)) < 0)
+				goto done;
+
+			git_parse_advance_ws(&ctx->parse_ctx);
+
+			if (git_parse_advance_expected_str(&ctx->parse_ctx, "\n") < 0 ||
+			    ctx->parse_ctx.line_len > 0) {
+				error = git_parse_err("trailing data at line %"PRIuZ, ctx->parse_ctx.line_num);
+				goto done;
+			}
+
+			found = true;
+			break;
+		}
+
+		if (!found) {
+			error = git_parse_err("invalid patch header at line %"PRIuZ,
+				ctx->parse_ctx.line_num);
+			goto done;
+		}
+	}
+
+	if (state != STATE_END) {
+		error = git_parse_err("unexpected header line %"PRIuZ, ctx->parse_ctx.line_num);
+		goto done;
+	}
+
+done:
+	return error;
+}
+
+static int parse_number(git_off_t *out, git_patch_parse_ctx *ctx)
+{
+	const char *end;
+	int64_t num;
+
+	if (!git__isdigit(ctx->parse_ctx.line[0]))
+		return -1;
+
+	if (git__strntol64(&num, ctx->parse_ctx.line, ctx->parse_ctx.line_len, &end, 10) < 0)
+		return -1;
+
+	if (num < 0)
+		return -1;
+
+	*out = num;
+	git_parse_advance_chars(&ctx->parse_ctx, (end - ctx->parse_ctx.line));
+
+	return 0;
+}
+
+static int parse_int(int *out, git_patch_parse_ctx *ctx)
+{
+	git_off_t num;
+
+	if (git_parse_advance_digit(&num, &ctx->parse_ctx, 10) < 0 || !git__is_int(num))
+		return -1;
+
+	*out = (int)num;
+	return 0;
+}
+
+static int parse_hunk_header(
+	git_patch_hunk *hunk,
+	git_patch_parse_ctx *ctx)
+{
+	const char *header_start = ctx->parse_ctx.line;
+	char c;
+
+	hunk->hunk.old_lines = 1;
+	hunk->hunk.new_lines = 1;
+
+	if (git_parse_advance_expected_str(&ctx->parse_ctx, "@@ -") < 0 ||
+		parse_int(&hunk->hunk.old_start, ctx) < 0)
+		goto fail;
+
+	if (git_parse_peek(&c, &ctx->parse_ctx, 0) == 0 && c == ',') {
+		if (git_parse_advance_expected_str(&ctx->parse_ctx, ",") < 0 ||
+			parse_int(&hunk->hunk.old_lines, ctx) < 0)
+			goto fail;
+	}
+
+	if (git_parse_advance_expected_str(&ctx->parse_ctx, " +") < 0 ||
+		parse_int(&hunk->hunk.new_start, ctx) < 0)
+		goto fail;
+
+	if (git_parse_peek(&c, &ctx->parse_ctx, 0) == 0 && c == ',') {
+		if (git_parse_advance_expected_str(&ctx->parse_ctx, ",") < 0 ||
+			parse_int(&hunk->hunk.new_lines, ctx) < 0)
+			goto fail;
+	}
+
+	if (git_parse_advance_expected_str(&ctx->parse_ctx, " @@") < 0)
+		goto fail;
+
+	git_parse_advance_line(&ctx->parse_ctx);
+
+	if (!hunk->hunk.old_lines && !hunk->hunk.new_lines)
+		goto fail;
+
+	hunk->hunk.header_len = ctx->parse_ctx.line - header_start;
+	if (hunk->hunk.header_len > (GIT_DIFF_HUNK_HEADER_SIZE - 1))
+		return git_parse_err("oversized patch hunk header at line %"PRIuZ,
+			ctx->parse_ctx.line_num);
+
+	memcpy(hunk->hunk.header, header_start, hunk->hunk.header_len);
+	hunk->hunk.header[hunk->hunk.header_len] = '\0';
+
+	return 0;
+
+fail:
+	giterr_set(GITERR_PATCH, "invalid patch hunk header at line %"PRIuZ,
+		ctx->parse_ctx.line_num);
+	return -1;
+}
+
+static int parse_hunk_body(
+	git_patch_parsed *patch,
+	git_patch_hunk *hunk,
+	git_patch_parse_ctx *ctx)
+{
+	git_diff_line *line;
+	int error = 0;
+
+	int oldlines = hunk->hunk.old_lines;
+	int newlines = hunk->hunk.new_lines;
+
+	for (;
+		ctx->parse_ctx.remain_len > 1 &&
+		(oldlines || newlines) &&
+		!git_parse_ctx_contains_s(&ctx->parse_ctx, "@@ -");
+		git_parse_advance_line(&ctx->parse_ctx)) {
+
+		char c;
+		int origin;
+		int prefix = 1;
+
+		if (ctx->parse_ctx.line_len == 0 || ctx->parse_ctx.line[ctx->parse_ctx.line_len - 1] != '\n') {
+			error = git_parse_err("invalid patch instruction at line %"PRIuZ,
+				ctx->parse_ctx.line_num);
+			goto done;
+		}
+
+		git_parse_peek(&c, &ctx->parse_ctx, 0);
+
+		switch (c) {
+		case '\n':
+			prefix = 0;
+			/* fall through */
+
+		case ' ':
+			origin = GIT_DIFF_LINE_CONTEXT;
+			oldlines--;
+			newlines--;
+			break;
+
+		case '-':
+			origin = GIT_DIFF_LINE_DELETION;
+			oldlines--;
+			break;
+
+		case '+':
+			origin = GIT_DIFF_LINE_ADDITION;
+			newlines--;
+			break;
+
+		default:
+			error = git_parse_err("invalid patch hunk at line %"PRIuZ, ctx->parse_ctx.line_num);
+			goto done;
+		}
+
+		line = git_array_alloc(patch->base.lines);
+		GITERR_CHECK_ALLOC(line);
+
+		memset(line, 0x0, sizeof(git_diff_line));
+
+		line->content = ctx->parse_ctx.line + prefix;
+		line->content_len = ctx->parse_ctx.line_len - prefix;
+		line->content_offset = ctx->parse_ctx.content_len - ctx->parse_ctx.remain_len;
+		line->origin = origin;
+
+		hunk->line_count++;
+	}
+
+	if (oldlines || newlines) {
+		error = git_parse_err(
+			"invalid patch hunk, expected %d old lines and %d new lines",
+			hunk->hunk.old_lines, hunk->hunk.new_lines);
+		goto done;
+	}
+
+	/* Handle "\ No newline at end of file".  Only expect the leading
+	 * backslash, though, because the rest of the string could be
+	 * localized.  Because `diff` optimizes for the case where you
+	 * want to apply the patch by hand.
+	 */
+	if (git_parse_ctx_contains_s(&ctx->parse_ctx, "\\ ") &&
+		git_array_size(patch->base.lines) > 0) {
+
+		line = git_array_get(patch->base.lines, git_array_size(patch->base.lines) - 1);
+
+		if (line->content_len < 1) {
+			error = git_parse_err("cannot trim trailing newline of empty line");
+			goto done;
+		}
+
+		line->content_len--;
+
+		git_parse_advance_line(&ctx->parse_ctx);
+	}
+
+done:
+	return error;
+}
+
+static int parse_patch_header(
+	git_patch_parsed *patch,
+	git_patch_parse_ctx *ctx)
+{
+	int error = 0;
+
+	for (; ctx->parse_ctx.remain_len > 0; git_parse_advance_line(&ctx->parse_ctx)) {
+		/* This line is too short to be a patch header. */
+		if (ctx->parse_ctx.line_len < 6)
+			continue;
+
+		/* This might be a hunk header without a patch header, provide a
+		 * sensible error message. */
+		if (git_parse_ctx_contains_s(&ctx->parse_ctx, "@@ -")) {
+			size_t line_num = ctx->parse_ctx.line_num;
+			git_patch_hunk hunk;
+
+			/* If this cannot be parsed as a hunk header, it's just leading
+			* noise, continue.
+			*/
+			if (parse_hunk_header(&hunk, ctx) < 0) {
+				giterr_clear();
+				continue;
+			}
+
+			error = git_parse_err("invalid hunk header outside patch at line %"PRIuZ,
+				line_num);
+			goto done;
+		}
+
+		/* This buffer is too short to contain a patch. */
+		if (ctx->parse_ctx.remain_len < ctx->parse_ctx.line_len + 6)
+			break;
+
+		/* A proper git patch */
+		if (git_parse_ctx_contains_s(&ctx->parse_ctx, "diff --git ")) {
+			error = parse_header_git(patch, ctx);
+			goto done;
+		}
+
+		error = 0;
+		continue;
+	}
+
+	giterr_set(GITERR_PATCH, "no patch found");
+	error = GIT_ENOTFOUND;
+
+done:
+	return error;
+}
+
+static int parse_patch_binary_side(
+	git_diff_binary_file *binary,
+	git_patch_parse_ctx *ctx)
+{
+	git_diff_binary_t type = GIT_DIFF_BINARY_NONE;
+	git_buf base85 = GIT_BUF_INIT, decoded = GIT_BUF_INIT;
+	git_off_t len;
+	int error = 0;
+
+	if (git_parse_ctx_contains_s(&ctx->parse_ctx, "literal ")) {
+		type = GIT_DIFF_BINARY_LITERAL;
+		git_parse_advance_chars(&ctx->parse_ctx, 8);
+	} else if (git_parse_ctx_contains_s(&ctx->parse_ctx, "delta ")) {
+		type = GIT_DIFF_BINARY_DELTA;
+		git_parse_advance_chars(&ctx->parse_ctx, 6);
+	} else {
+		error = git_parse_err(
+			"unknown binary delta type at line %"PRIuZ, ctx->parse_ctx.line_num);
+		goto done;
+	}
+
+	if (git_parse_advance_digit(&len, &ctx->parse_ctx, 10) < 0 ||
+	    git_parse_advance_nl(&ctx->parse_ctx) < 0 || len < 0) {
+		error = git_parse_err("invalid binary size at line %"PRIuZ, ctx->parse_ctx.line_num);
+		goto done;
+	}
+
+	while (ctx->parse_ctx.line_len) {
+		char c;
+		size_t encoded_len, decoded_len = 0, decoded_orig = decoded.size;
+
+		git_parse_peek(&c, &ctx->parse_ctx, 0);
+
+		if (c == '\n')
+			break;
+		else if (c >= 'A' && c <= 'Z')
+			decoded_len = c - 'A' + 1;
+		else if (c >= 'a' && c <= 'z')
+			decoded_len = c - 'a' + (('z' - 'a') + 1) + 1;
+
+		if (!decoded_len) {
+			error = git_parse_err("invalid binary length at line %"PRIuZ, ctx->parse_ctx.line_num);
+			goto done;
+		}
+
+		git_parse_advance_chars(&ctx->parse_ctx, 1);
+
+		encoded_len = ((decoded_len / 4) + !!(decoded_len % 4)) * 5;
+
+		if (encoded_len > ctx->parse_ctx.line_len - 1) {
+			error = git_parse_err("truncated binary data at line %"PRIuZ, ctx->parse_ctx.line_num);
+			goto done;
+		}
+
+		if ((error = git_buf_decode_base85(
+			&decoded, ctx->parse_ctx.line, encoded_len, decoded_len)) < 0)
+			goto done;
+
+		if (decoded.size - decoded_orig != decoded_len) {
+			error = git_parse_err("truncated binary data at line %"PRIuZ, ctx->parse_ctx.line_num);
+			goto done;
+		}
+
+		git_parse_advance_chars(&ctx->parse_ctx, encoded_len);
+
+		if (git_parse_advance_nl(&ctx->parse_ctx) < 0) {
+			error = git_parse_err("trailing data at line %"PRIuZ, ctx->parse_ctx.line_num);
+			goto done;
+		}
+	}
+
+	binary->type = type;
+	binary->inflatedlen = (size_t)len;
+	binary->datalen = decoded.size;
+	binary->data = git_buf_detach(&decoded);
+
+done:
+	git_buf_free(&base85);
+	git_buf_free(&decoded);
+	return error;
+}
+
+static int parse_patch_binary(
+	git_patch_parsed *patch,
+	git_patch_parse_ctx *ctx)
+{
+	int error;
+
+	if (git_parse_advance_expected_str(&ctx->parse_ctx, "GIT binary patch") < 0 ||
+		git_parse_advance_nl(&ctx->parse_ctx) < 0)
+		return git_parse_err("corrupt git binary header at line %"PRIuZ, ctx->parse_ctx.line_num);
+
+	/* parse old->new binary diff */
+	if ((error = parse_patch_binary_side(
+			&patch->base.binary.new_file, ctx)) < 0)
+		return error;
+
+	if (git_parse_advance_nl(&ctx->parse_ctx) < 0)
+		return git_parse_err("corrupt git binary separator at line %"PRIuZ,
+			ctx->parse_ctx.line_num);
+
+	/* parse new->old binary diff */
+	if ((error = parse_patch_binary_side(
+			&patch->base.binary.old_file, ctx)) < 0)
+		return error;
+
+	if (git_parse_advance_nl(&ctx->parse_ctx) < 0)
+		return git_parse_err("corrupt git binary patch separator at line %"PRIuZ,
+			ctx->parse_ctx.line_num);
+
+	patch->base.binary.contains_data = 1;
+	patch->base.delta->flags |= GIT_DIFF_FLAG_BINARY;
+	return 0;
+}
+
+static int parse_patch_binary_nodata(
+	git_patch_parsed *patch,
+	git_patch_parse_ctx *ctx)
+{
+	if (git_parse_advance_expected_str(&ctx->parse_ctx, "Binary files ") < 0 ||
+		git_parse_advance_expected_str(&ctx->parse_ctx, patch->header_old_path) < 0 ||
+		git_parse_advance_expected_str(&ctx->parse_ctx, " and ") < 0 ||
+		git_parse_advance_expected_str(&ctx->parse_ctx, patch->header_new_path) < 0 ||
+		git_parse_advance_expected_str(&ctx->parse_ctx, " differ") < 0 ||
+		git_parse_advance_nl(&ctx->parse_ctx) < 0)
+		return git_parse_err("corrupt git binary header at line %"PRIuZ, ctx->parse_ctx.line_num);
+
+	patch->base.binary.contains_data = 0;
+	patch->base.delta->flags |= GIT_DIFF_FLAG_BINARY;
+	return 0;
+}
+
+static int parse_patch_hunks(
+	git_patch_parsed *patch,
+	git_patch_parse_ctx *ctx)
+{
+	git_patch_hunk *hunk;
+	int error = 0;
+
+	while (git_parse_ctx_contains_s(&ctx->parse_ctx, "@@ -")) {
+		hunk = git_array_alloc(patch->base.hunks);
+		GITERR_CHECK_ALLOC(hunk);
+
+		memset(hunk, 0, sizeof(git_patch_hunk));
+
+		hunk->line_start = git_array_size(patch->base.lines);
+		hunk->line_count = 0;
+
+		if ((error = parse_hunk_header(hunk, ctx)) < 0 ||
+			(error = parse_hunk_body(patch, hunk, ctx)) < 0)
+			goto done;
+	}
+
+	patch->base.delta->flags |= GIT_DIFF_FLAG_NOT_BINARY;
+
+done:
+	return error;
+}
+
+static int parse_patch_body(
+	git_patch_parsed *patch, git_patch_parse_ctx *ctx)
+{
+	if (git_parse_ctx_contains_s(&ctx->parse_ctx, "GIT binary patch"))
+		return parse_patch_binary(patch, ctx);
+	else if (git_parse_ctx_contains_s(&ctx->parse_ctx, "Binary files "))
+		return parse_patch_binary_nodata(patch, ctx);
+	else
+		return parse_patch_hunks(patch, ctx);
+}
+
+int check_header_names(
+	const char *one,
+	const char *two,
+	const char *old_or_new,
+	bool two_null)
+{
+	if (!one || !two)
+		return 0;
+
+	if (two_null && strcmp(two, "/dev/null") != 0)
+		return git_parse_err("expected %s path of '/dev/null'", old_or_new);
+
+	else if (!two_null && strcmp(one, two) != 0)
+		return git_parse_err("mismatched %s path names", old_or_new);
+
+	return 0;
+}
+
+static int check_prefix(
+	char **out,
+	size_t *out_len,
+	git_patch_parsed *patch,
+	const char *path_start)
+{
+	const char *path = path_start;
+	size_t prefix_len = patch->ctx->opts.prefix_len;
+	size_t remain_len = prefix_len;
+
+	*out = NULL;
+	*out_len = 0;
+
+	if (prefix_len == 0)
+		goto done;
+
+	/* leading slashes do not count as part of the prefix in git apply */
+	while (*path == '/')
+		path++;
+
+	while (*path && remain_len) {
+		if (*path == '/')
+			remain_len--;
+
+		path++;
+	}
+
+	if (remain_len || !*path)
+		return git_parse_err(
+			"header filename does not contain %"PRIuZ" path components",
+			prefix_len);
+
+done:
+	*out_len = (path - path_start);
+	*out = git__strndup(path_start, *out_len);
+
+	return (*out == NULL) ? -1 : 0;
+}
+
+static int check_filenames(git_patch_parsed *patch)
+{
+	const char *prefixed_new, *prefixed_old;
+	size_t old_prefixlen = 0, new_prefixlen = 0;
+	bool added = (patch->base.delta->status == GIT_DELTA_ADDED);
+	bool deleted = (patch->base.delta->status == GIT_DELTA_DELETED);
+
+	if (patch->old_path && !patch->new_path)
+		return git_parse_err("missing new path");
+
+	if (!patch->old_path && patch->new_path)
+		return git_parse_err("missing old path");
+
+	/* Ensure (non-renamed) paths match */
+	if (check_header_names(
+			patch->header_old_path, patch->old_path, "old", added) < 0 ||
+		check_header_names(
+			patch->header_new_path, patch->new_path, "new", deleted) < 0)
+		return -1;
+
+	prefixed_old = (!added && patch->old_path) ? patch->old_path :
+		patch->header_old_path;
+	prefixed_new = (!deleted && patch->new_path) ? patch->new_path :
+		patch->header_new_path;
+
+	if (check_prefix(
+			&patch->old_prefix, &old_prefixlen, patch, prefixed_old) < 0 ||
+		check_prefix(
+			&patch->new_prefix, &new_prefixlen, patch, prefixed_new) < 0)
+		return -1;
+
+	/* Prefer the rename filenames as they are unambiguous and unprefixed */
+	if (patch->rename_old_path)
+		patch->base.delta->old_file.path = patch->rename_old_path;
+	else
+		patch->base.delta->old_file.path = prefixed_old + old_prefixlen;
+
+	if (patch->rename_new_path)
+		patch->base.delta->new_file.path = patch->rename_new_path;
+	else
+		patch->base.delta->new_file.path = prefixed_new + new_prefixlen;
+
+	if (!patch->base.delta->old_file.path &&
+		!patch->base.delta->new_file.path)
+		return git_parse_err("git diff header lacks old / new paths");
+
+	return 0;
+}
+
+static int check_patch(git_patch_parsed *patch)
+{
+	git_diff_delta *delta = patch->base.delta;
+
+	if (check_filenames(patch) < 0)
+		return -1;
+
+	if (delta->old_file.path &&
+			delta->status != GIT_DELTA_DELETED &&
+			!delta->new_file.mode)
+		delta->new_file.mode = delta->old_file.mode;
+
+	if (delta->status == GIT_DELTA_MODIFIED &&
+			!(delta->flags & GIT_DIFF_FLAG_BINARY) &&
+			delta->new_file.mode == delta->old_file.mode &&
+			git_array_size(patch->base.hunks) == 0)
+		return git_parse_err("patch with no hunks");
+
+	if (delta->status == GIT_DELTA_ADDED) {
+		memset(&delta->old_file.id, 0x0, sizeof(git_oid));
+		delta->old_file.id_abbrev = 0;
+	}
+
+	if (delta->status == GIT_DELTA_DELETED) {
+		memset(&delta->new_file.id, 0x0, sizeof(git_oid));
+		delta->new_file.id_abbrev = 0;
+	}
+
+	return 0;
+}
+
+git_patch_parse_ctx *git_patch_parse_ctx_init(
+	const char *content,
+	size_t content_len,
+	const git_patch_options *opts)
+{
+	git_patch_parse_ctx *ctx;
+	git_patch_options default_opts = GIT_PATCH_OPTIONS_INIT;
+
+	if ((ctx = git__calloc(1, sizeof(git_patch_parse_ctx))) == NULL)
+		return NULL;
+
+	if ((git_parse_ctx_init(&ctx->parse_ctx, content, content_len)) < 0) {
+		git__free(ctx);
+		return NULL;
+	}
+
+	if (opts)
+		memcpy(&ctx->opts, opts, sizeof(git_patch_options));
+	else
+		memcpy(&ctx->opts, &default_opts, sizeof(git_patch_options));
+
+	GIT_REFCOUNT_INC(ctx);
+	return ctx;
+}
+
+static void patch_parse_ctx_free(git_patch_parse_ctx *ctx)
+{
+	if (!ctx)
+		return;
+
+	git_parse_ctx_clear(&ctx->parse_ctx);
+	git__free(ctx);
+}
+
+void git_patch_parse_ctx_free(git_patch_parse_ctx *ctx)
+{
+	GIT_REFCOUNT_DEC(ctx, patch_parse_ctx_free);
+}
+
+int git_patch_parsed_from_diff(git_patch **out, git_diff *d, size_t idx)
+{
+	git_diff_parsed *diff = (git_diff_parsed *)d;
+	git_patch *p;
+
+	if ((p = git_vector_get(&diff->patches, idx)) == NULL)
+		return -1;
+
+	GIT_REFCOUNT_INC(p);
+	*out = p;
+
+	return 0;
+}
+
+static void patch_parsed__free(git_patch *p)
+{
+	git_patch_parsed *patch = (git_patch_parsed *)p;
+
+	if (!patch)
+		return;
+
+	git_patch_parse_ctx_free(patch->ctx);
+
+	git__free((char *)patch->base.binary.old_file.data);
+	git__free((char *)patch->base.binary.new_file.data);
+	git_array_clear(patch->base.hunks);
+	git_array_clear(patch->base.lines);
+	git__free(patch->base.delta);
+
+	git__free(patch->old_prefix);
+	git__free(patch->new_prefix);
+	git__free(patch->header_old_path);
+	git__free(patch->header_new_path);
+	git__free(patch->rename_old_path);
+	git__free(patch->rename_new_path);
+	git__free(patch->old_path);
+	git__free(patch->new_path);
+	git__free(patch);
+}
+
+int git_patch_parse(
+	git_patch **out,
+	git_patch_parse_ctx *ctx)
+{
+	git_patch_parsed *patch;
+	size_t start, used;
+	int error = 0;
+
+	assert(out && ctx);
+
+	*out = NULL;
+
+	patch = git__calloc(1, sizeof(git_patch_parsed));
+	GITERR_CHECK_ALLOC(patch);
+
+	patch->ctx = ctx;
+	GIT_REFCOUNT_INC(patch->ctx);
+
+	patch->base.free_fn = patch_parsed__free;
+
+	patch->base.delta = git__calloc(1, sizeof(git_diff_delta));
+	GITERR_CHECK_ALLOC(patch->base.delta);
+
+	patch->base.delta->status = GIT_DELTA_MODIFIED;
+	patch->base.delta->nfiles = 2;
+
+	start = ctx->parse_ctx.remain_len;
+
+	if ((error = parse_patch_header(patch, ctx)) < 0 ||
+		(error = parse_patch_body(patch, ctx)) < 0 ||
+		(error = check_patch(patch)) < 0)
+		goto done;
+
+	used = start - ctx->parse_ctx.remain_len;
+	ctx->parse_ctx.remain += used;
+
+	patch->base.diff_opts.old_prefix = patch->old_prefix;
+	patch->base.diff_opts.new_prefix = patch->new_prefix;
+	patch->base.diff_opts.flags |= GIT_DIFF_SHOW_BINARY;
+
+	GIT_REFCOUNT_INC(&patch->base);
+	*out = &patch->base;
+
+done:
+	if (error < 0)
+		patch_parsed__free(&patch->base);
+
+	return error;
+}
+
+int git_patch_from_buffer(
+	git_patch **out,
+	const char *content,
+	size_t content_len,
+	const git_patch_options *opts)
+{
+	git_patch_parse_ctx *ctx;
+	int error;
+
+	ctx = git_patch_parse_ctx_init(content, content_len, opts);
+	GITERR_CHECK_ALLOC(ctx);
+
+	error = git_patch_parse(out, ctx);
+
+	git_patch_parse_ctx_free(ctx);
+	return error;
+}
+

vendor/libgit2-sys/libgit2/src/patch_parse.h

diff --git a/vendor/libgit2-sys/libgit2/src/patch_parse.h b/vendor/libgit2-sys/libgit2/src/patch_parse.h
new file mode 100644
index 0000000..140629d
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/patch_parse.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_patch_parse_h__
+#define INCLUDE_patch_parse_h__
+
+#include "common.h"
+
+#include "parse.h"
+#include "patch.h"
+
+typedef struct {
+	git_refcount rc;
+
+	git_patch_options opts;
+
+	git_parse_ctx parse_ctx;
+} git_patch_parse_ctx;
+
+extern git_patch_parse_ctx *git_patch_parse_ctx_init(
+	const char *content,
+	size_t content_len,
+	const git_patch_options *opts);
+
+extern void git_patch_parse_ctx_free(git_patch_parse_ctx *ctx);
+
+/**
+ * Create a patch for a single file from the contents of a patch buffer.
+ *
+ * @param out The patch to be created
+ * @param contents The contents of a patch file
+ * @param contents_len The length of the patch file
+ * @param opts The git_patch_options
+ * @return 0 on success, <0 on failure.
+ */
+extern int git_patch_from_buffer(
+	git_patch **out,
+	const char *contents,
+	size_t contents_len,
+	const git_patch_options *opts);
+
+extern int git_patch_parse(
+	git_patch **out,
+	git_patch_parse_ctx *ctx);
+
+extern int git_patch_parsed_from_diff(git_patch **, git_diff *, size_t);
+
+#endif

vendor/libgit2-sys/libgit2/src/path.c

diff --git a/vendor/libgit2-sys/libgit2/src/path.c b/vendor/libgit2-sys/libgit2/src/path.c
new file mode 100644
index 0000000..58a5aaf
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/path.c
@@ -0,0 +1,1935 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "path.h"
+
+#include "posix.h"
+#include "repository.h"
+#ifdef GIT_WIN32
+#include "win32/posix.h"
+#include "win32/w32_buffer.h"
+#include "win32/w32_util.h"
+#include "win32/version.h"
+#else
+#include <dirent.h>
+#endif
+#include <stdio.h>
+#include <ctype.h>
+
+#define LOOKS_LIKE_DRIVE_PREFIX(S) (git__isalpha((S)[0]) && (S)[1] == ':')
+
+#ifdef GIT_WIN32
+static bool looks_like_network_computer_name(const char *path, int pos)
+{
+	if (pos < 3)
+		return false;
+
+	if (path[0] != '/' || path[1] != '/')
+		return false;
+
+	while (pos-- > 2) {
+		if (path[pos] == '/')
+			return false;
+	}
+
+	return true;
+}
+#endif
+
+/*
+ * Based on the Android implementation, BSD licensed.
+ * http://android.git.kernel.org/
+ *
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in
+ *   the documentation and/or other materials provided with the
+ *   distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * AS IS AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+int git_path_basename_r(git_buf *buffer, const char *path)
+{
+	const char *endp, *startp;
+	int len, result;
+
+	/* Empty or NULL string gets treated as "." */
+	if (path == NULL || *path == '\0') {
+		startp = ".";
+		len		= 1;
+		goto Exit;
+	}
+
+	/* Strip trailing slashes */
+	endp = path + strlen(path) - 1;
+	while (endp > path && *endp == '/')
+		endp--;
+
+	/* All slashes becomes "/" */
+	if (endp == path && *endp == '/') {
+		startp = "/";
+		len	= 1;
+		goto Exit;
+	}
+
+	/* Find the start of the base */
+	startp = endp;
+	while (startp > path && *(startp - 1) != '/')
+		startp--;
+
+	/* Cast is safe because max path < max int */
+	len = (int)(endp - startp + 1);
+
+Exit:
+	result = len;
+
+	if (buffer != NULL && git_buf_set(buffer, startp, len) < 0)
+		return -1;
+
+	return result;
+}
+
+/*
+ * Determine if the path is a Windows prefix and, if so, returns
+ * its actual lentgh. If it is not a prefix, returns -1.
+ */
+static int win32_prefix_length(const char *path, int len)
+{
+#ifndef GIT_WIN32
+	GIT_UNUSED(path);
+	GIT_UNUSED(len);
+#else
+	/*
+	 * Mimic unix behavior where '/.git' returns '/': 'C:/.git' will return
+	 * 'C:/' here
+	 */
+	if (len == 2 && LOOKS_LIKE_DRIVE_PREFIX(path))
+		return 2;
+
+	/*
+	 * Similarly checks if we're dealing with a network computer name
+	 * '//computername/.git' will return '//computername/'
+	 */
+	if (looks_like_network_computer_name(path, len))
+		return len;
+#endif
+
+	return -1;
+}
+
+/*
+ * Based on the Android implementation, BSD licensed.
+ * Check http://android.git.kernel.org/
+ */
+int git_path_dirname_r(git_buf *buffer, const char *path)
+{
+	const char *endp;
+	int is_prefix = 0, len;
+
+	/* Empty or NULL string gets treated as "." */
+	if (path == NULL || *path == '\0') {
+		path = ".";
+		len = 1;
+		goto Exit;
+	}
+
+	/* Strip trailing slashes */
+	endp = path + strlen(path) - 1;
+	while (endp > path && *endp == '/')
+		endp--;
+
+	if ((len = win32_prefix_length(path, endp - path + 1)) > 0) {
+		is_prefix = 1;
+		goto Exit;
+	}
+
+	/* Find the start of the dir */
+	while (endp > path && *endp != '/')
+		endp--;
+
+	/* Either the dir is "/" or there are no slashes */
+	if (endp == path) {
+		path = (*endp == '/') ? "/" : ".";
+		len = 1;
+		goto Exit;
+	}
+
+	do {
+		endp--;
+	} while (endp > path && *endp == '/');
+
+	if ((len = win32_prefix_length(path, endp - path + 1)) > 0) {
+		is_prefix = 1;
+		goto Exit;
+	}
+
+	/* Cast is safe because max path < max int */
+	len = (int)(endp - path + 1);
+
+Exit:
+	if (buffer) {
+		if (git_buf_set(buffer, path, len) < 0)
+			return -1;
+		if (is_prefix && git_buf_putc(buffer, '/') < 0)
+			return -1;
+	}
+
+	return len;
+}
+
+
+char *git_path_dirname(const char *path)
+{
+	git_buf buf = GIT_BUF_INIT;
+	char *dirname;
+
+	git_path_dirname_r(&buf, path);
+	dirname = git_buf_detach(&buf);
+	git_buf_free(&buf); /* avoid memleak if error occurs */
+
+	return dirname;
+}
+
+char *git_path_basename(const char *path)
+{
+	git_buf buf = GIT_BUF_INIT;
+	char *basename;
+
+	git_path_basename_r(&buf, path);
+	basename = git_buf_detach(&buf);
+	git_buf_free(&buf); /* avoid memleak if error occurs */
+
+	return basename;
+}
+
+size_t git_path_basename_offset(git_buf *buffer)
+{
+	ssize_t slash;
+
+	if (!buffer || buffer->size <= 0)
+		return 0;
+
+	slash = git_buf_rfind_next(buffer, '/');
+
+	if (slash >= 0 && buffer->ptr[slash] == '/')
+		return (size_t)(slash + 1);
+
+	return 0;
+}
+
+const char *git_path_topdir(const char *path)
+{
+	size_t len;
+	ssize_t i;
+
+	assert(path);
+	len = strlen(path);
+
+	if (!len || path[len - 1] != '/')
+		return NULL;
+
+	for (i = (ssize_t)len - 2; i >= 0; --i)
+		if (path[i] == '/')
+			break;
+
+	return &path[i + 1];
+}
+
+int git_path_root(const char *path)
+{
+	int offset = 0;
+
+	/* Does the root of the path look like a windows drive ? */
+	if (LOOKS_LIKE_DRIVE_PREFIX(path))
+		offset += 2;
+
+#ifdef GIT_WIN32
+	/* Are we dealing with a windows network path? */
+	else if ((path[0] == '/' && path[1] == '/' && path[2] != '/') ||
+		(path[0] == '\\' && path[1] == '\\' && path[2] != '\\'))
+	{
+		offset += 2;
+
+		/* Skip the computer name segment */
+		while (path[offset] && path[offset] != '/' && path[offset] != '\\')
+			offset++;
+	}
+#endif
+
+	if (path[offset] == '/' || path[offset] == '\\')
+		return offset;
+
+	return -1;	/* Not a real error - signals that path is not rooted */
+}
+
+void git_path_trim_slashes(git_buf *path)
+{
+	int ceiling = git_path_root(path->ptr) + 1;
+	assert(ceiling >= 0);
+
+	while (path->size > (size_t)ceiling) {
+		if (path->ptr[path->size-1] != '/')
+			break;
+
+		path->ptr[path->size-1] = '\0';
+		path->size--;
+	}
+}
+
+int git_path_join_unrooted(
+	git_buf *path_out, const char *path, const char *base, ssize_t *root_at)
+{
+	ssize_t root;
+
+	assert(path && path_out);
+
+	root = (ssize_t)git_path_root(path);
+
+	if (base != NULL && root < 0) {
+		if (git_buf_joinpath(path_out, base, path) < 0)
+			return -1;
+
+		root = (ssize_t)strlen(base);
+	} else {
+		if (git_buf_sets(path_out, path) < 0)
+			return -1;
+
+		if (root < 0)
+			root = 0;
+		else if (base)
+			git_path_equal_or_prefixed(base, path, &root);
+	}
+
+	if (root_at)
+		*root_at = root;
+
+	return 0;
+}
+
+void git_path_squash_slashes(git_buf *path)
+{
+	char *p, *q;
+
+	if (path->size == 0)
+		return;
+
+	for (p = path->ptr, q = path->ptr; *q; p++, q++) {
+		*p = *q;
+
+		while (*q == '/' && *(q+1) == '/') {
+			path->size--;
+			q++;
+		}
+	}
+
+	*p = '\0';
+}
+
+int git_path_prettify(git_buf *path_out, const char *path, const char *base)
+{
+	char buf[GIT_PATH_MAX];
+
+	assert(path && path_out);
+
+	/* construct path if needed */
+	if (base != NULL && git_path_root(path) < 0) {
+		if (git_buf_joinpath(path_out, base, path) < 0)
+			return -1;
+		path = path_out->ptr;
+	}
+
+	if (p_realpath(path, buf) == NULL) {
+		/* giterr_set resets the errno when dealing with a GITERR_OS kind of error */
+		int error = (errno == ENOENT || errno == ENOTDIR) ? GIT_ENOTFOUND : -1;
+		giterr_set(GITERR_OS, "failed to resolve path '%s'", path);
+
+		git_buf_clear(path_out);
+
+		return error;
+	}
+
+	return git_buf_sets(path_out, buf);
+}
+
+int git_path_prettify_dir(git_buf *path_out, const char *path, const char *base)
+{
+	int error = git_path_prettify(path_out, path, base);
+	return (error < 0) ? error : git_path_to_dir(path_out);
+}
+
+int git_path_to_dir(git_buf *path)
+{
+	if (path->asize > 0 &&
+		git_buf_len(path) > 0 &&
+		path->ptr[git_buf_len(path) - 1] != '/')
+		git_buf_putc(path, '/');
+
+	return git_buf_oom(path) ? -1 : 0;
+}
+
+void git_path_string_to_dir(char* path, size_t size)
+{
+	size_t end = strlen(path);
+
+	if (end && path[end - 1] != '/' && end < size) {
+		path[end] = '/';
+		path[end + 1] = '\0';
+	}
+}
+
+int git__percent_decode(git_buf *decoded_out, const char *input)
+{
+	int len, hi, lo, i;
+	assert(decoded_out && input);
+
+	len = (int)strlen(input);
+	git_buf_clear(decoded_out);
+
+	for(i = 0; i < len; i++)
+	{
+		char c = input[i];
+
+		if (c != '%')
+			goto append;
+
+		if (i >= len - 2)
+			goto append;
+
+		hi = git__fromhex(input[i + 1]);
+		lo = git__fromhex(input[i + 2]);
+
+		if (hi < 0 || lo < 0)
+			goto append;
+
+		c = (char)(hi << 4 | lo);
+		i += 2;
+
+append:
+		if (git_buf_putc(decoded_out, c) < 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+static int error_invalid_local_file_uri(const char *uri)
+{
+	giterr_set(GITERR_CONFIG, "'%s' is not a valid local file URI", uri);
+	return -1;
+}
+
+static int local_file_url_prefixlen(const char *file_url)
+{
+	int len = -1;
+
+	if (git__prefixcmp(file_url, "file://") == 0) {
+		if (file_url[7] == '/')
+			len = 8;
+		else if (git__prefixcmp(file_url + 7, "localhost/") == 0)
+			len = 17;
+	}
+
+	return len;
+}
+
+bool git_path_is_local_file_url(const char *file_url)
+{
+	return (local_file_url_prefixlen(file_url) > 0);
+}
+
+int git_path_fromurl(git_buf *local_path_out, const char *file_url)
+{
+	int offset;
+
+	assert(local_path_out && file_url);
+
+	if ((offset = local_file_url_prefixlen(file_url)) < 0 ||
+		file_url[offset] == '\0' || file_url[offset] == '/')
+		return error_invalid_local_file_uri(file_url);
+
+#ifndef GIT_WIN32
+	offset--;	/* A *nix absolute path starts with a forward slash */
+#endif
+
+	git_buf_clear(local_path_out);
+	return git__percent_decode(local_path_out, file_url + offset);
+}
+
+int git_path_walk_up(
+	git_buf *path,
+	const char *ceiling,
+	int (*cb)(void *data, const char *),
+	void *data)
+{
+	int error = 0;
+	git_buf iter;
+	ssize_t stop = 0, scan;
+	char oldc = '\0';
+
+	assert(path && cb);
+
+	if (ceiling != NULL) {
+		if (git__prefixcmp(path->ptr, ceiling) == 0)
+			stop = (ssize_t)strlen(ceiling);
+		else
+			stop = git_buf_len(path);
+	}
+	scan = git_buf_len(path);
+
+	/* empty path: yield only once */
+	if (!scan) {
+		error = cb(data, "");
+		if (error)
+			giterr_set_after_callback(error);
+		return error;
+	}
+
+	iter.ptr = path->ptr;
+	iter.size = git_buf_len(path);
+	iter.asize = path->asize;
+
+	while (scan >= stop) {
+		error = cb(data, iter.ptr);
+		iter.ptr[scan] = oldc;
+
+		if (error) {
+			giterr_set_after_callback(error);
+			break;
+		}
+
+		scan = git_buf_rfind_next(&iter, '/');
+		if (scan >= 0) {
+			scan++;
+			oldc = iter.ptr[scan];
+			iter.size = scan;
+			iter.ptr[scan] = '\0';
+		}
+	}
+
+	if (scan >= 0)
+		iter.ptr[scan] = oldc;
+
+	/* relative path: yield for the last component */
+	if (!error && stop == 0 && iter.ptr[0] != '/') {
+		error = cb(data, "");
+		if (error)
+			giterr_set_after_callback(error);
+	}
+
+	return error;
+}
+
+bool git_path_exists(const char *path)
+{
+	assert(path);
+	return p_access(path, F_OK) == 0;
+}
+
+bool git_path_isdir(const char *path)
+{
+	struct stat st;
+	if (p_stat(path, &st) < 0)
+		return false;
+
+	return S_ISDIR(st.st_mode) != 0;
+}
+
+bool git_path_isfile(const char *path)
+{
+	struct stat st;
+
+	assert(path);
+	if (p_stat(path, &st) < 0)
+		return false;
+
+	return S_ISREG(st.st_mode) != 0;
+}
+
+bool git_path_islink(const char *path)
+{
+	struct stat st;
+
+	assert(path);
+	if (p_lstat(path, &st) < 0)
+		return false;
+
+	return S_ISLNK(st.st_mode) != 0;
+}
+
+#ifdef GIT_WIN32
+
+bool git_path_is_empty_dir(const char *path)
+{
+	git_win32_path filter_w;
+	bool empty = false;
+
+	if (git_win32__findfirstfile_filter(filter_w, path)) {
+		WIN32_FIND_DATAW findData;
+		HANDLE hFind = FindFirstFileW(filter_w, &findData);
+
+		/* FindFirstFile will fail if there are no children to the given
+		 * path, which can happen if the given path is a file (and obviously
+		 * has no children) or if the given path is an empty mount point.
+		 * (Most directories have at least directory entries '.' and '..',
+		 * but ridiculously another volume mounted in another drive letter's
+		 * path space do not, and thus have nothing to enumerate.)  If
+		 * FindFirstFile fails, check if this is a directory-like thing
+		 * (a mount point).
+		 */
+		if (hFind == INVALID_HANDLE_VALUE)
+			return git_path_isdir(path);
+
+		/* If the find handle was created successfully, then it's a directory */
+		empty = true;
+
+		do {
+			/* Allow the enumeration to return . and .. and still be considered
+			 * empty. In the special case of drive roots (i.e. C:\) where . and
+			 * .. do not occur, we can still consider the path to be an empty
+			 * directory if there's nothing there. */
+			if (!git_path_is_dot_or_dotdotW(findData.cFileName)) {
+				empty = false;
+				break;
+			}
+		} while (FindNextFileW(hFind, &findData));
+
+		FindClose(hFind);
+	}
+
+	return empty;
+}
+
+#else
+
+static int path_found_entry(void *payload, git_buf *path)
+{
+	GIT_UNUSED(payload);
+	return !git_path_is_dot_or_dotdot(path->ptr);
+}
+
+bool git_path_is_empty_dir(const char *path)
+{
+	int error;
+	git_buf dir = GIT_BUF_INIT;
+
+	if (!git_path_isdir(path))
+		return false;
+
+	if ((error = git_buf_sets(&dir, path)) != 0)
+		giterr_clear();
+	else
+		error = git_path_direach(&dir, 0, path_found_entry, NULL);
+
+	git_buf_free(&dir);
+
+	return !error;
+}
+
+#endif
+
+int git_path_set_error(int errno_value, const char *path, const char *action)
+{
+	switch (errno_value) {
+	case ENOENT:
+	case ENOTDIR:
+		giterr_set(GITERR_OS, "could not find '%s' to %s", path, action);
+		return GIT_ENOTFOUND;
+
+	case EINVAL:
+	case ENAMETOOLONG:
+		giterr_set(GITERR_OS, "invalid path for filesystem '%s'", path);
+		return GIT_EINVALIDSPEC;
+
+	case EEXIST:
+		giterr_set(GITERR_OS, "failed %s - '%s' already exists", action, path);
+		return GIT_EEXISTS;
+
+	case EACCES:
+		giterr_set(GITERR_OS, "failed %s - '%s' is locked", action, path);
+		return GIT_ELOCKED;
+
+	default:
+		giterr_set(GITERR_OS, "could not %s '%s'", action, path);
+		return -1;
+	}
+}
+
+int git_path_lstat(const char *path, struct stat *st)
+{
+	if (p_lstat(path, st) == 0)
+		return 0;
+
+	return git_path_set_error(errno, path, "stat");
+}
+
+static bool _check_dir_contents(
+	git_buf *dir,
+	const char *sub,
+	bool (*predicate)(const char *))
+{
+	bool result;
+	size_t dir_size = git_buf_len(dir);
+	size_t sub_size = strlen(sub);
+	size_t alloc_size;
+
+	/* leave base valid even if we could not make space for subdir */
+	if (GIT_ADD_SIZET_OVERFLOW(&alloc_size, dir_size, sub_size) ||
+		GIT_ADD_SIZET_OVERFLOW(&alloc_size, alloc_size, 2) ||
+		git_buf_try_grow(dir, alloc_size, false) < 0)
+		return false;
+
+	/* save excursion */
+	if (git_buf_joinpath(dir, dir->ptr, sub) < 0)
+		return false;
+
+	result = predicate(dir->ptr);
+
+	/* restore path */
+	git_buf_truncate(dir, dir_size);
+	return result;
+}
+
+bool git_path_contains(git_buf *dir, const char *item)
+{
+	return _check_dir_contents(dir, item, &git_path_exists);
+}
+
+bool git_path_contains_dir(git_buf *base, const char *subdir)
+{
+	return _check_dir_contents(base, subdir, &git_path_isdir);
+}
+
+bool git_path_contains_file(git_buf *base, const char *file)
+{
+	return _check_dir_contents(base, file, &git_path_isfile);
+}
+
+int git_path_find_dir(git_buf *dir, const char *path, const char *base)
+{
+	int error = git_path_join_unrooted(dir, path, base, NULL);
+
+	if (!error) {
+		char buf[GIT_PATH_MAX];
+		if (p_realpath(dir->ptr, buf) != NULL)
+			error = git_buf_sets(dir, buf);
+	}
+
+	/* call dirname if this is not a directory */
+	if (!error) /* && git_path_isdir(dir->ptr) == false) */
+		error = (git_path_dirname_r(dir, dir->ptr) < 0) ? -1 : 0;
+
+	if (!error)
+		error = git_path_to_dir(dir);
+
+	return error;
+}
+
+int git_path_resolve_relative(git_buf *path, size_t ceiling)
+{
+	char *base, *to, *from, *next;
+	size_t len;
+
+	GITERR_CHECK_ALLOC_BUF(path);
+
+	if (ceiling > path->size)
+		ceiling = path->size;
+
+	/* recognize drive prefixes, etc. that should not be backed over */
+	if (ceiling == 0)
+		ceiling = git_path_root(path->ptr) + 1;
+
+	/* recognize URL prefixes that should not be backed over */
+	if (ceiling == 0) {
+		for (next = path->ptr; *next && git__isalpha(*next); ++next);
+		if (next[0] == ':' && next[1] == '/' && next[2] == '/')
+			ceiling = (next + 3) - path->ptr;
+	}
+
+	base = to = from = path->ptr + ceiling;
+
+	while (*from) {
+		for (next = from; *next && *next != '/'; ++next);
+
+		len = next - from;
+
+		if (len == 1 && from[0] == '.')
+			/* do nothing with singleton dot */;
+
+		else if (len == 2 && from[0] == '.' && from[1] == '.') {
+			/* error out if trying to up one from a hard base */
+			if (to == base && ceiling != 0) {
+				giterr_set(GITERR_INVALID,
+					"cannot strip root component off url");
+				return -1;
+			}
+
+			/* no more path segments to strip,
+			 * use '../' as a new base path */
+			if (to == base) {
+				if (*next == '/')
+					len++;
+
+				if (to != from)
+					memmove(to, from, len);
+
+				to += len;
+				/* this is now the base, can't back up from a
+				 * relative prefix */
+				base = to;
+			} else {
+				/* back up a path segment */
+				while (to > base && to[-1] == '/') to--;
+				while (to > base && to[-1] != '/') to--;
+			}
+		} else {
+			if (*next == '/' && *from != '/')
+				len++;
+
+			if (to != from)
+				memmove(to, from, len);
+
+			to += len;
+		}
+
+		from += len;
+
+		while (*from == '/') from++;
+	}
+
+	*to = '\0';
+
+	path->size = to - path->ptr;
+
+	return 0;
+}
+
+int git_path_apply_relative(git_buf *target, const char *relpath)
+{
+	return git_buf_joinpath(target, git_buf_cstr(target), relpath) ||
+	    git_path_resolve_relative(target, 0);
+}
+
+int git_path_cmp(
+	const char *name1, size_t len1, int isdir1,
+	const char *name2, size_t len2, int isdir2,
+	int (*compare)(const char *, const char *, size_t))
+{
+	unsigned char c1, c2;
+	size_t len = len1 < len2 ? len1 : len2;
+	int cmp;
+
+	cmp = compare(name1, name2, len);
+	if (cmp)
+		return cmp;
+
+	c1 = name1[len];
+	c2 = name2[len];
+
+	if (c1 == '\0' && isdir1)
+		c1 = '/';
+
+	if (c2 == '\0' && isdir2)
+		c2 = '/';
+
+	return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
+}
+
+size_t git_path_common_dirlen(const char *one, const char *two)
+{
+	const char *p, *q, *dirsep = NULL;
+
+	for (p = one, q = two; *p && *q; p++, q++) {
+		if (*p == '/' && *q == '/')
+			dirsep = p;
+		else if (*p != *q)
+			break;
+	}
+
+	return dirsep ? (dirsep - one) + 1 : 0;
+}
+
+int git_path_make_relative(git_buf *path, const char *parent)
+{
+	const char *p, *q, *p_dirsep, *q_dirsep;
+	size_t plen = path->size, newlen, alloclen, depth = 1, i, offset;
+
+	for (p_dirsep = p = path->ptr, q_dirsep = q = parent; *p && *q; p++, q++) {
+		if (*p == '/' && *q == '/') {
+			p_dirsep = p;
+			q_dirsep = q;
+		}
+		else if (*p != *q)
+			break;
+	}
+
+	/* need at least 1 common path segment */
+	if ((p_dirsep == path->ptr || q_dirsep == parent) &&
+		(*p_dirsep != '/' || *q_dirsep != '/')) {
+		giterr_set(GITERR_INVALID,
+			"%s is not a parent of %s", parent, path->ptr);
+		return GIT_ENOTFOUND;
+	}
+
+	if (*p == '/' && !*q)
+		p++;
+	else if (!*p && *q == '/')
+		q++;
+	else if (!*p && !*q)
+		return git_buf_clear(path), 0;
+	else {
+		p = p_dirsep + 1;
+		q = q_dirsep + 1;
+	}
+
+	plen -= (p - path->ptr);
+
+	if (!*q)
+		return git_buf_set(path, p, plen);
+
+	for (; (q = strchr(q, '/')) && *(q + 1); q++)
+		depth++;
+
+	GITERR_CHECK_ALLOC_MULTIPLY(&newlen, depth, 3);
+	GITERR_CHECK_ALLOC_ADD(&newlen, newlen, plen);
+
+	GITERR_CHECK_ALLOC_ADD(&alloclen, newlen, 1);
+
+	/* save the offset as we might realllocate the pointer */
+	offset = p - path->ptr;
+	if (git_buf_try_grow(path, alloclen, 1) < 0)
+		return -1;
+	p = path->ptr + offset;
+
+	memmove(path->ptr + (depth * 3), p, plen + 1);
+
+	for (i = 0; i < depth; i++)
+		memcpy(path->ptr + (i * 3), "../", 3);
+
+	path->size = newlen;
+	return 0;
+}
+
+bool git_path_has_non_ascii(const char *path, size_t pathlen)
+{
+	const uint8_t *scan = (const uint8_t *)path, *end;
+
+	for (end = scan + pathlen; scan < end; ++scan)
+		if (*scan & 0x80)
+			return true;
+
+	return false;
+}
+
+#ifdef GIT_USE_ICONV
+
+int git_path_iconv_init_precompose(git_path_iconv_t *ic)
+{
+	git_buf_init(&ic->buf, 0);
+	ic->map = iconv_open(GIT_PATH_REPO_ENCODING, GIT_PATH_NATIVE_ENCODING);
+	return 0;
+}
+
+void git_path_iconv_clear(git_path_iconv_t *ic)
+{
+	if (ic) {
+		if (ic->map != (iconv_t)-1)
+			iconv_close(ic->map);
+		git_buf_free(&ic->buf);
+	}
+}
+
+int git_path_iconv(git_path_iconv_t *ic, const char **in, size_t *inlen)
+{
+	char *nfd = (char*)*in, *nfc;
+	size_t nfdlen = *inlen, nfclen, wantlen = nfdlen, alloclen, rv;
+	int retry = 1;
+
+	if (!ic || ic->map == (iconv_t)-1 ||
+		!git_path_has_non_ascii(*in, *inlen))
+		return 0;
+
+	git_buf_clear(&ic->buf);
+
+	while (1) {
+		GITERR_CHECK_ALLOC_ADD(&alloclen, wantlen, 1);
+		if (git_buf_grow(&ic->buf, alloclen) < 0)
+			return -1;
+
+		nfc    = ic->buf.ptr   + ic->buf.size;
+		nfclen = ic->buf.asize - ic->buf.size;
+
+		rv = iconv(ic->map, &nfd, &nfdlen, &nfc, &nfclen);
+
+		ic->buf.size = (nfc - ic->buf.ptr);
+
+		if (rv != (size_t)-1)
+			break;
+
+		/* if we cannot convert the data (probably because iconv thinks
+		 * it is not valid UTF-8 source data), then use original data
+		 */
+		if (errno != E2BIG)
+			return 0;
+
+		/* make space for 2x the remaining data to be converted
+		 * (with per retry overhead to avoid infinite loops)
+		 */
+		wantlen = ic->buf.size + max(nfclen, nfdlen) * 2 + (size_t)(retry * 4);
+
+		if (retry++ > 4)
+			goto fail;
+	}
+
+	ic->buf.ptr[ic->buf.size] = '\0';
+
+	*in    = ic->buf.ptr;
+	*inlen = ic->buf.size;
+
+	return 0;
+
+fail:
+	giterr_set(GITERR_OS, "unable to convert unicode path data");
+	return -1;
+}
+
+static const char *nfc_file = "\xC3\x85\x73\x74\x72\xC3\xB6\x6D.XXXXXX";
+static const char *nfd_file = "\x41\xCC\x8A\x73\x74\x72\x6F\xCC\x88\x6D.XXXXXX";
+
+/* Check if the platform is decomposing unicode data for us.  We will
+ * emulate core Git and prefer to use precomposed unicode data internally
+ * on these platforms, composing the decomposed unicode on the fly.
+ *
+ * This mainly happens on the Mac where HDFS stores filenames as
+ * decomposed unicode.  Even on VFAT and SAMBA file systems, the Mac will
+ * return decomposed unicode from readdir() even when the actual
+ * filesystem is storing precomposed unicode.
+ */
+bool git_path_does_fs_decompose_unicode(const char *root)
+{
+	git_buf path = GIT_BUF_INIT;
+	int fd;
+	bool found_decomposed = false;
+	char tmp[6];
+
+	/* Create a file using a precomposed path and then try to find it
+	 * using the decomposed name.  If the lookup fails, then we will mark
+	 * that we should precompose unicode for this repository.
+	 */
+	if (git_buf_joinpath(&path, root, nfc_file) < 0 ||
+		(fd = p_mkstemp(path.ptr)) < 0)
+		goto done;
+	p_close(fd);
+
+	/* record trailing digits generated by mkstemp */
+	memcpy(tmp, path.ptr + path.size - sizeof(tmp), sizeof(tmp));
+
+	/* try to look up as NFD path */
+	if (git_buf_joinpath(&path, root, nfd_file) < 0)
+		goto done;
+	memcpy(path.ptr + path.size - sizeof(tmp), tmp, sizeof(tmp));
+
+	found_decomposed = git_path_exists(path.ptr);
+
+	/* remove temporary file (using original precomposed path) */
+	if (git_buf_joinpath(&path, root, nfc_file) < 0)
+		goto done;
+	memcpy(path.ptr + path.size - sizeof(tmp), tmp, sizeof(tmp));
+
+	(void)p_unlink(path.ptr);
+
+done:
+	git_buf_free(&path);
+	return found_decomposed;
+}
+
+#else
+
+bool git_path_does_fs_decompose_unicode(const char *root)
+{
+	GIT_UNUSED(root);
+	return false;
+}
+
+#endif
+
+#if defined(__sun) || defined(__GNU__)
+typedef char path_dirent_data[sizeof(struct dirent) + FILENAME_MAX + 1];
+#else
+typedef struct dirent path_dirent_data;
+#endif
+
+int git_path_direach(
+	git_buf *path,
+	uint32_t flags,
+	int (*fn)(void *, git_buf *),
+	void *arg)
+{
+	int error = 0;
+	ssize_t wd_len;
+	DIR *dir;
+	struct dirent *de;
+
+#ifdef GIT_USE_ICONV
+	git_path_iconv_t ic = GIT_PATH_ICONV_INIT;
+#endif
+
+	GIT_UNUSED(flags);
+
+	if (git_path_to_dir(path) < 0)
+		return -1;
+
+	wd_len = git_buf_len(path);
+
+	if ((dir = opendir(path->ptr)) == NULL) {
+		giterr_set(GITERR_OS, "failed to open directory '%s'", path->ptr);
+		if (errno == ENOENT)
+			return GIT_ENOTFOUND;
+
+		return -1;
+	}
+
+#ifdef GIT_USE_ICONV
+	if ((flags & GIT_PATH_DIR_PRECOMPOSE_UNICODE) != 0)
+		(void)git_path_iconv_init_precompose(&ic);
+#endif
+
+	while ((de = readdir(dir)) != NULL) {
+		const char *de_path = de->d_name;
+		size_t de_len = strlen(de_path);
+
+		if (git_path_is_dot_or_dotdot(de_path))
+			continue;
+
+#ifdef GIT_USE_ICONV
+		if ((error = git_path_iconv(&ic, &de_path, &de_len)) < 0)
+			break;
+#endif
+
+		if ((error = git_buf_put(path, de_path, de_len)) < 0)
+			break;
+
+		giterr_clear();
+		error = fn(arg, path);
+
+		git_buf_truncate(path, wd_len); /* restore path */
+
+		/* Only set our own error if the callback did not set one already */
+		if (error != 0) {
+			if (!giterr_last())
+				giterr_set_after_callback(error);
+
+			break;
+		}
+	}
+
+	closedir(dir);
+
+#ifdef GIT_USE_ICONV
+	git_path_iconv_clear(&ic);
+#endif
+
+	return error;
+}
+
+#if defined(GIT_WIN32) && !defined(__MINGW32__)
+
+/* Using _FIND_FIRST_EX_LARGE_FETCH may increase performance in Windows 7
+ * and better.
+ */
+#ifndef FIND_FIRST_EX_LARGE_FETCH
+# define FIND_FIRST_EX_LARGE_FETCH 2
+#endif
+
+int git_path_diriter_init(
+	git_path_diriter *diriter,
+	const char *path,
+	unsigned int flags)
+{
+	git_win32_path path_filter;
+
+	static int is_win7_or_later = -1;
+	if (is_win7_or_later < 0)
+		is_win7_or_later = git_has_win32_version(6, 1, 0);
+
+	assert(diriter && path);
+
+	memset(diriter, 0, sizeof(git_path_diriter));
+	diriter->handle = INVALID_HANDLE_VALUE;
+
+	if (git_buf_puts(&diriter->path_utf8, path) < 0)
+		return -1;
+
+	git_path_trim_slashes(&diriter->path_utf8);
+
+	if (diriter->path_utf8.size == 0) {
+		giterr_set(GITERR_FILESYSTEM, "could not open directory '%s'", path);
+		return -1;
+	}
+
+	if ((diriter->parent_len = git_win32_path_from_utf8(diriter->path, diriter->path_utf8.ptr)) < 0 ||
+			!git_win32__findfirstfile_filter(path_filter, diriter->path_utf8.ptr)) {
+		giterr_set(GITERR_OS, "could not parse the directory path '%s'", path);
+		return -1;
+	}
+
+	diriter->handle = FindFirstFileExW(
+		path_filter,
+		is_win7_or_later ? FindExInfoBasic : FindExInfoStandard,
+		&diriter->current,
+		FindExSearchNameMatch,
+		NULL,
+		is_win7_or_later ? FIND_FIRST_EX_LARGE_FETCH : 0);
+
+	if (diriter->handle == INVALID_HANDLE_VALUE) {
+		giterr_set(GITERR_OS, "could not open directory '%s'", path);
+		return -1;
+	}
+
+	diriter->parent_utf8_len = diriter->path_utf8.size;
+	diriter->flags = flags;
+	return 0;
+}
+
+static int diriter_update_paths(git_path_diriter *diriter)
+{
+	size_t filename_len, path_len;
+
+	filename_len = wcslen(diriter->current.cFileName);
+
+	if (GIT_ADD_SIZET_OVERFLOW(&path_len, diriter->parent_len, filename_len) ||
+		GIT_ADD_SIZET_OVERFLOW(&path_len, path_len, 2))
+		return -1;
+
+	if (path_len > GIT_WIN_PATH_UTF16) {
+		giterr_set(GITERR_FILESYSTEM,
+			"invalid path '%.*ls\\%ls' (path too long)",
+			diriter->parent_len, diriter->path, diriter->current.cFileName);
+		return -1;
+	}
+
+	diriter->path[diriter->parent_len] = L'\\';
+	memcpy(&diriter->path[diriter->parent_len+1],
+		diriter->current.cFileName, filename_len * sizeof(wchar_t));
+	diriter->path[path_len-1] = L'\0';
+
+	git_buf_truncate(&diriter->path_utf8, diriter->parent_utf8_len);
+
+	if (diriter->parent_utf8_len > 0 &&
+		diriter->path_utf8.ptr[diriter->parent_utf8_len-1] != '/')
+		git_buf_putc(&diriter->path_utf8, '/');
+
+	git_buf_put_w(&diriter->path_utf8, diriter->current.cFileName, filename_len);
+
+	if (git_buf_oom(&diriter->path_utf8))
+		return -1;
+
+	return 0;
+}
+
+int git_path_diriter_next(git_path_diriter *diriter)
+{
+	bool skip_dot = !(diriter->flags & GIT_PATH_DIR_INCLUDE_DOT_AND_DOTDOT);
+
+	do {
+		/* Our first time through, we already have the data from
+		 * FindFirstFileW.  Use it, otherwise get the next file.
+		 */
+		if (!diriter->needs_next)
+			diriter->needs_next = 1;
+		else if (!FindNextFileW(diriter->handle, &diriter->current))
+			return GIT_ITEROVER;
+	} while (skip_dot && git_path_is_dot_or_dotdotW(diriter->current.cFileName));
+
+	if (diriter_update_paths(diriter) < 0)
+		return -1;
+
+	return 0;
+}
+
+int git_path_diriter_filename(
+	const char **out,
+	size_t *out_len,
+	git_path_diriter *diriter)
+{
+	assert(out && out_len && diriter);
+
+	assert(diriter->path_utf8.size > diriter->parent_utf8_len);
+
+	*out = &diriter->path_utf8.ptr[diriter->parent_utf8_len+1];
+	*out_len = diriter->path_utf8.size - diriter->parent_utf8_len - 1;
+	return 0;
+}
+
+int git_path_diriter_fullpath(
+	const char **out,
+	size_t *out_len,
+	git_path_diriter *diriter)
+{
+	assert(out && out_len && diriter);
+
+	*out = diriter->path_utf8.ptr;
+	*out_len = diriter->path_utf8.size;
+	return 0;
+}
+
+int git_path_diriter_stat(struct stat *out, git_path_diriter *diriter)
+{
+	assert(out && diriter);
+
+	return git_win32__file_attribute_to_stat(out,
+		(WIN32_FILE_ATTRIBUTE_DATA *)&diriter->current,
+		diriter->path);
+}
+
+void git_path_diriter_free(git_path_diriter *diriter)
+{
+	if (diriter == NULL)
+		return;
+
+	git_buf_free(&diriter->path_utf8);
+
+	if (diriter->handle != INVALID_HANDLE_VALUE) {
+		FindClose(diriter->handle);
+		diriter->handle = INVALID_HANDLE_VALUE;
+	}
+}
+
+#else
+
+int git_path_diriter_init(
+	git_path_diriter *diriter,
+	const char *path,
+	unsigned int flags)
+{
+	assert(diriter && path);
+
+	memset(diriter, 0, sizeof(git_path_diriter));
+
+	if (git_buf_puts(&diriter->path, path) < 0)
+		return -1;
+
+	git_path_trim_slashes(&diriter->path);
+
+	if (diriter->path.size == 0) {
+		giterr_set(GITERR_FILESYSTEM, "could not open directory '%s'", path);
+		return -1;
+	}
+
+	if ((diriter->dir = opendir(diriter->path.ptr)) == NULL) {
+		git_buf_free(&diriter->path);
+
+		giterr_set(GITERR_OS, "failed to open directory '%s'", path);
+		return -1;
+	}
+
+#ifdef GIT_USE_ICONV
+	if ((flags & GIT_PATH_DIR_PRECOMPOSE_UNICODE) != 0)
+		(void)git_path_iconv_init_precompose(&diriter->ic);
+#endif
+
+	diriter->parent_len = diriter->path.size;
+	diriter->flags = flags;
+
+	return 0;
+}
+
+int git_path_diriter_next(git_path_diriter *diriter)
+{
+	struct dirent *de;
+	const char *filename;
+	size_t filename_len;
+	bool skip_dot = !(diriter->flags & GIT_PATH_DIR_INCLUDE_DOT_AND_DOTDOT);
+	int error = 0;
+
+	assert(diriter);
+
+	errno = 0;
+
+	do {
+		if ((de = readdir(diriter->dir)) == NULL) {
+			if (!errno)
+				return GIT_ITEROVER;
+
+			giterr_set(GITERR_OS,
+				"could not read directory '%s'", diriter->path.ptr);
+			return -1;
+		}
+	} while (skip_dot && git_path_is_dot_or_dotdot(de->d_name));
+
+	filename = de->d_name;
+	filename_len = strlen(filename);
+
+#ifdef GIT_USE_ICONV
+	if ((diriter->flags & GIT_PATH_DIR_PRECOMPOSE_UNICODE) != 0 &&
+		(error = git_path_iconv(&diriter->ic, &filename, &filename_len)) < 0)
+		return error;
+#endif
+
+	git_buf_truncate(&diriter->path, diriter->parent_len);
+
+	if (diriter->parent_len > 0 &&
+		diriter->path.ptr[diriter->parent_len-1] != '/')
+		git_buf_putc(&diriter->path, '/');
+
+	git_buf_put(&diriter->path, filename, filename_len);
+
+	if (git_buf_oom(&diriter->path))
+		return -1;
+
+	return error;
+}
+
+int git_path_diriter_filename(
+	const char **out,
+	size_t *out_len,
+	git_path_diriter *diriter)
+{
+	assert(out && out_len && diriter);
+
+	assert(diriter->path.size > diriter->parent_len);
+
+	*out = &diriter->path.ptr[diriter->parent_len+1];
+	*out_len = diriter->path.size - diriter->parent_len - 1;
+	return 0;
+}
+
+int git_path_diriter_fullpath(
+	const char **out,
+	size_t *out_len,
+	git_path_diriter *diriter)
+{
+	assert(out && out_len && diriter);
+
+	*out = diriter->path.ptr;
+	*out_len = diriter->path.size;
+	return 0;
+}
+
+int git_path_diriter_stat(struct stat *out, git_path_diriter *diriter)
+{
+	assert(out && diriter);
+
+	return git_path_lstat(diriter->path.ptr, out);
+}
+
+void git_path_diriter_free(git_path_diriter *diriter)
+{
+	if (diriter == NULL)
+		return;
+
+	if (diriter->dir) {
+		closedir(diriter->dir);
+		diriter->dir = NULL;
+	}
+
+#ifdef GIT_USE_ICONV
+	git_path_iconv_clear(&diriter->ic);
+#endif
+
+	git_buf_free(&diriter->path);
+}
+
+#endif
+
+int git_path_dirload(
+	git_vector *contents,
+	const char *path,
+	size_t prefix_len,
+	uint32_t flags)
+{
+	git_path_diriter iter = GIT_PATH_DIRITER_INIT;
+	const char *name;
+	size_t name_len;
+	char *dup;
+	int error;
+
+	assert(contents && path);
+
+	if ((error = git_path_diriter_init(&iter, path, flags)) < 0)
+		return error;
+
+	while ((error = git_path_diriter_next(&iter)) == 0) {
+		if ((error = git_path_diriter_fullpath(&name, &name_len, &iter)) < 0)
+			break;
+
+		assert(name_len > prefix_len);
+
+		dup = git__strndup(name + prefix_len, name_len - prefix_len);
+		GITERR_CHECK_ALLOC(dup);
+
+		if ((error = git_vector_insert(contents, dup)) < 0)
+			break;
+	}
+
+	if (error == GIT_ITEROVER)
+		error = 0;
+
+	git_path_diriter_free(&iter);
+	return error;
+}
+
+int git_path_from_url_or_path(git_buf *local_path_out, const char *url_or_path)
+{
+	if (git_path_is_local_file_url(url_or_path))
+		return git_path_fromurl(local_path_out, url_or_path);
+	else
+		return git_buf_sets(local_path_out, url_or_path);
+}
+
+/* Reject paths like AUX or COM1, or those versions that end in a dot or
+ * colon.  ("AUX." or "AUX:")
+ */
+GIT_INLINE(bool) verify_dospath(
+	const char *component,
+	size_t len,
+	const char dospath[3],
+	bool trailing_num)
+{
+	size_t last = trailing_num ? 4 : 3;
+
+	if (len < last || git__strncasecmp(component, dospath, 3) != 0)
+		return true;
+
+	if (trailing_num && (component[3] < '1' || component[3] > '9'))
+		return true;
+
+	return (len > last &&
+		component[last] != '.' &&
+		component[last] != ':');
+}
+
+static int32_t next_hfs_char(const char **in, size_t *len)
+{
+	while (*len) {
+		int32_t codepoint;
+		int cp_len = git__utf8_iterate((const uint8_t *)(*in), (int)(*len), &codepoint);
+		if (cp_len < 0)
+			return -1;
+
+		(*in) += cp_len;
+		(*len) -= cp_len;
+
+		/* these code points are ignored completely */
+		switch (codepoint) {
+		case 0x200c: /* ZERO WIDTH NON-JOINER */
+		case 0x200d: /* ZERO WIDTH JOINER */
+		case 0x200e: /* LEFT-TO-RIGHT MARK */
+		case 0x200f: /* RIGHT-TO-LEFT MARK */
+		case 0x202a: /* LEFT-TO-RIGHT EMBEDDING */
+		case 0x202b: /* RIGHT-TO-LEFT EMBEDDING */
+		case 0x202c: /* POP DIRECTIONAL FORMATTING */
+		case 0x202d: /* LEFT-TO-RIGHT OVERRIDE */
+		case 0x202e: /* RIGHT-TO-LEFT OVERRIDE */
+		case 0x206a: /* INHIBIT SYMMETRIC SWAPPING */
+		case 0x206b: /* ACTIVATE SYMMETRIC SWAPPING */
+		case 0x206c: /* INHIBIT ARABIC FORM SHAPING */
+		case 0x206d: /* ACTIVATE ARABIC FORM SHAPING */
+		case 0x206e: /* NATIONAL DIGIT SHAPES */
+		case 0x206f: /* NOMINAL DIGIT SHAPES */
+		case 0xfeff: /* ZERO WIDTH NO-BREAK SPACE */
+			continue;
+		}
+
+		/* fold into lowercase -- this will only fold characters in
+		 * the ASCII range, which is perfectly fine, because the
+		 * git folder name can only be composed of ascii characters
+		 */
+		return git__tolower(codepoint);
+	}
+	return 0; /* NULL byte -- end of string */
+}
+
+static bool verify_dotgit_hfs_generic(const char *path, size_t len, const char *needle, size_t needle_len)
+{
+	size_t i;
+	char c;
+
+	if (next_hfs_char(&path, &len) != '.')
+		return true;
+
+	for (i = 0; i < needle_len; i++) {
+		c = next_hfs_char(&path, &len);
+		if (c != needle[i])
+			return true;
+	}
+
+	if (next_hfs_char(&path, &len) != '\0')
+		return true;
+
+	return false;
+}
+
+static bool verify_dotgit_hfs(const char *path, size_t len)
+{
+	return verify_dotgit_hfs_generic(path, len, "git", CONST_STRLEN("git"));
+}
+
+GIT_INLINE(bool) verify_dotgit_ntfs(git_repository *repo, const char *path, size_t len)
+{
+	git_buf *reserved = git_repository__reserved_names_win32;
+	size_t reserved_len = git_repository__reserved_names_win32_len;
+	size_t start = 0, i;
+
+	if (repo)
+		git_repository__reserved_names(&reserved, &reserved_len, repo, true);
+
+	for (i = 0; i < reserved_len; i++) {
+		git_buf *r = &reserved[i];
+
+		if (len >= r->size &&
+			strncasecmp(path, r->ptr, r->size) == 0) {
+			start = r->size;
+			break;
+		}
+	}
+
+	if (!start)
+		return true;
+
+	/* Reject paths like ".git\" */
+	if (path[start] == '\\')
+		return false;
+
+	/* Reject paths like '.git ' or '.git.' */
+	for (i = start; i < len; i++) {
+		if (path[i] != ' ' && path[i] != '.')
+			return true;
+	}
+
+	return false;
+}
+
+GIT_INLINE(bool) only_spaces_and_dots(const char *path)
+{
+	const char *c = path;
+
+	for (;; c++) {
+		if (*c == '\0')
+			return true;
+		if (*c != ' ' && *c != '.')
+			return false;
+	}
+
+	return true;
+}
+
+GIT_INLINE(bool) verify_dotgit_ntfs_generic(const char *name, size_t len, const char *dotgit_name, size_t dotgit_len, const char *shortname_pfix)
+{
+	int i, saw_tilde;
+
+	if (name[0] == '.' && len >= dotgit_len &&
+	    !strncasecmp(name + 1, dotgit_name, dotgit_len)) {
+		return !only_spaces_and_dots(name + dotgit_len + 1);
+	}
+
+	/* Detect the basic NTFS shortname with the first six chars */
+	if (!strncasecmp(name, dotgit_name, 6) && name[6] == '~' &&
+	    name[7] >= '1' && name[7] <= '4')
+		return !only_spaces_and_dots(name + 8);
+
+	/* Catch fallback names */
+	for (i = 0, saw_tilde = 0; i < 8; i++) {
+		if (name[i] == '\0') {
+			return true;
+		} else if (saw_tilde) {
+			if (name[i] < '0' || name[i] > '9')
+				return true;
+		} else if (name[i] == '~') {
+			if (name[i+1] < '1' || name[i+1]  > '9')
+				return true;
+			saw_tilde = 1;
+		} else if (i >= 6) {
+			return true;
+		} else if (name[i] < 0) {
+			return true;
+		} else if (git__tolower(name[i]) != shortname_pfix[i]) {
+			return true;
+		}
+	}
+
+	return !only_spaces_and_dots(name + i);
+}
+
+GIT_INLINE(bool) verify_char(unsigned char c, unsigned int flags)
+{
+	if ((flags & GIT_PATH_REJECT_BACKSLASH) && c == '\\')
+		return false;
+
+	if ((flags & GIT_PATH_REJECT_SLASH) && c == '/')
+		return false;
+
+	if (flags & GIT_PATH_REJECT_NT_CHARS) {
+		if (c < 32)
+			return false;
+
+		switch (c) {
+		case '<':
+		case '>':
+		case ':':
+		case '"':
+		case '|':
+		case '?':
+		case '*':
+			return false;
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Return the length of the common prefix between str and prefix, comparing them
+ * case-insensitively (must be ASCII to match).
+ */
+GIT_INLINE(size_t) common_prefix_icase(const char *str, size_t len, const char *prefix)
+{
+	size_t count = 0;
+
+	while (len >0 && tolower(*str) == tolower(*prefix)) {
+		count++;
+		str++;
+		prefix++;
+		len--;
+	}
+
+	return count;
+}
+
+/*
+ * We fundamentally don't like some paths when dealing with user-inputted
+ * strings (in checkout or ref names): we don't want dot or dot-dot
+ * anywhere, we want to avoid writing weird paths on Windows that can't
+ * be handled by tools that use the non-\\?\ APIs, we don't want slashes
+ * or double slashes at the end of paths that can make them ambiguous.
+ *
+ * For checkout, we don't want to recurse into ".git" either.
+ */
+static bool verify_component(
+	git_repository *repo,
+	const char *component,
+	size_t len,
+	uint16_t mode,
+	unsigned int flags)
+{
+	if (len == 0)
+		return false;
+
+	if ((flags & GIT_PATH_REJECT_TRAVERSAL) &&
+		len == 1 && component[0] == '.')
+		return false;
+
+	if ((flags & GIT_PATH_REJECT_TRAVERSAL) &&
+		len == 2 && component[0] == '.' && component[1] == '.')
+		return false;
+
+	if ((flags & GIT_PATH_REJECT_TRAILING_DOT) && component[len-1] == '.')
+		return false;
+
+	if ((flags & GIT_PATH_REJECT_TRAILING_SPACE) && component[len-1] == ' ')
+		return false;
+
+	if ((flags & GIT_PATH_REJECT_TRAILING_COLON) && component[len-1] == ':')
+		return false;
+
+	if (flags & GIT_PATH_REJECT_DOS_PATHS) {
+		if (!verify_dospath(component, len, "CON", false) ||
+			!verify_dospath(component, len, "PRN", false) ||
+			!verify_dospath(component, len, "AUX", false) ||
+			!verify_dospath(component, len, "NUL", false) ||
+			!verify_dospath(component, len, "COM", true)  ||
+			!verify_dospath(component, len, "LPT", true))
+			return false;
+	}
+
+	if (flags & GIT_PATH_REJECT_DOT_GIT_HFS) {
+		if (!verify_dotgit_hfs(component, len))
+			return false;
+		if (S_ISLNK(mode) && git_path_is_hfs_dotgit_modules(component, len))
+			return false;
+	}
+
+	if (flags & GIT_PATH_REJECT_DOT_GIT_NTFS) {
+		if (!verify_dotgit_ntfs(repo, component, len))
+			return false;
+		if (S_ISLNK(mode) && git_path_is_ntfs_dotgit_modules(component, len))
+			return false;
+	}
+
+	/* don't bother rerunning the `.git` test if we ran the HFS or NTFS
+	 * specific tests, they would have already rejected `.git`.
+	 */
+	if ((flags & GIT_PATH_REJECT_DOT_GIT_HFS) == 0 &&
+	    (flags & GIT_PATH_REJECT_DOT_GIT_NTFS) == 0 &&
+	    (flags & GIT_PATH_REJECT_DOT_GIT_LITERAL)) {
+		if (len >= 4 &&
+		    component[0] == '.' &&
+		    (component[1] == 'g' || component[1] == 'G') &&
+		    (component[2] == 'i' || component[2] == 'I') &&
+		    (component[3] == 't' || component[3] == 'T')) {
+			if (len == 4)
+				return false;
+
+			if (S_ISLNK(mode) && common_prefix_icase(component, len, ".gitmodules") == len)
+				return false;
+		}
+	    }
+
+	return true;
+}
+
+GIT_INLINE(unsigned int) dotgit_flags(
+	git_repository *repo,
+	unsigned int flags)
+{
+	int protectHFS = 0, protectNTFS = 0;
+	int error = 0;
+
+	flags |= GIT_PATH_REJECT_DOT_GIT_LITERAL;
+
+#ifdef __APPLE__
+	protectHFS = 1;
+#endif
+
+#ifdef GIT_WIN32
+	protectNTFS = 1;
+#endif
+
+	if (repo && !protectHFS)
+		error = git_repository__cvar(&protectHFS, repo, GIT_CVAR_PROTECTHFS);
+	if (!error && protectHFS)
+		flags |= GIT_PATH_REJECT_DOT_GIT_HFS;
+
+	if (repo && !protectNTFS)
+		error = git_repository__cvar(&protectNTFS, repo, GIT_CVAR_PROTECTNTFS);
+	if (!error && protectNTFS)
+		flags |= GIT_PATH_REJECT_DOT_GIT_NTFS;
+
+	return flags;
+}
+
+bool git_path_isvalid(
+	git_repository *repo,
+	const char *path,
+	uint16_t mode,
+	unsigned int flags)
+{
+	const char *start, *c;
+
+	/* Upgrade the ".git" checks based on platform */
+	if ((flags & GIT_PATH_REJECT_DOT_GIT))
+		flags = dotgit_flags(repo, flags);
+
+	for (start = c = path; *c; c++) {
+		if (!verify_char(*c, flags))
+			return false;
+
+		if (*c == '/') {
+			if (!verify_component(repo, start, (c - start), mode, flags))
+				return false;
+
+			start = c+1;
+		}
+	}
+
+	return verify_component(repo, start, (c - start), mode, flags);
+}
+
+int git_path_normalize_slashes(git_buf *out, const char *path)
+{
+	int error;
+	char *p;
+
+	if ((error = git_buf_puts(out, path)) < 0)
+		return error;
+
+	for (p = out->ptr; *p; p++) {
+		if (*p == '\\')
+			*p = '/';
+	}
+
+	return 0;
+}
+
+static int verify_dotgit_generic(const char *name, size_t len, const char *dotgit_name, size_t dotgit_len, const char *shortname_pfix)
+{
+	if (!verify_dotgit_ntfs_generic(name, len, dotgit_name, dotgit_len, shortname_pfix))
+		return false;
+
+	return verify_dotgit_hfs_generic(name, len, dotgit_name, dotgit_len);
+}
+
+int git_path_is_ntfs_dotgit_modules(const char *name, size_t len)
+{
+	return !verify_dotgit_ntfs_generic(name, len, "gitmodules", CONST_STRLEN("gitmodules"), "gi7eba");
+}
+
+int git_path_is_hfs_dotgit_modules(const char *name, size_t len)
+{
+	return !verify_dotgit_hfs_generic(name, len, "gitmodules", CONST_STRLEN("gitmodules"));
+}
+
+int git_path_is_dotgit_modules(const char *name, size_t len)
+{
+	if (git_path_is_hfs_dotgit_modules(name, len))
+		return 1;
+
+	return git_path_is_ntfs_dotgit_modules(name, len);
+}
+
+int git_path_is_ntfs_dotgit_ignore(const char *name, size_t len)
+{
+	return !verify_dotgit_ntfs_generic(name, len, "gitignore", CONST_STRLEN("gitignore"), "gi250a");
+}
+
+int git_path_is_hfs_dotgit_ignore(const char *name, size_t len)
+{
+	return !verify_dotgit_hfs_generic(name, len, "gitignore", CONST_STRLEN("gitignore"));
+}
+
+int git_path_is_dotgit_ignore(const char *name, size_t len)
+{
+	if (git_path_is_hfs_dotgit_ignore(name, len))
+		return 1;
+
+	return git_path_is_ntfs_dotgit_ignore(name, len);
+}
+
+int git_path_is_hfs_dotgit_attributes(const char *name, size_t len)
+{
+	return !verify_dotgit_hfs_generic(name, len, "gitattributes", CONST_STRLEN("gitattributes"));
+}
+
+int git_path_is_ntfs_dotgit_attributes(const char *name, size_t len)
+{
+	return !verify_dotgit_ntfs_generic(name, len, "gitattributes", CONST_STRLEN("gitattributes"), "gi7d29");
+}
+
+int git_path_is_dotgit_attributes(const char *name, size_t len)
+{
+	if (git_path_is_hfs_dotgit_attributes(name, len))
+		return 1;
+
+	return git_path_is_ntfs_dotgit_attributes(name, len);
+}

vendor/libgit2-sys/libgit2/src/path.h

diff --git a/vendor/libgit2-sys/libgit2/src/path.h b/vendor/libgit2-sys/libgit2/src/path.h
new file mode 100644
index 0000000..fd515c8
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/path.h
@@ -0,0 +1,720 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_path_h__
+#define INCLUDE_path_h__
+
+#include "common.h"
+
+#include "posix.h"
+#include "buffer.h"
+#include "vector.h"
+
+/**
+ * Path manipulation utils
+ *
+ * These are path utilities that munge paths without actually
+ * looking at the real filesystem.
+ */
+
+/*
+ * The dirname() function shall take a pointer to a character string
+ * that contains a pathname, and return a pointer to a string that is a
+ * pathname of the parent directory of that file. Trailing '/' characters
+ * in the path are not counted as part of the path.
+ *
+ * If path does not contain a '/', then dirname() shall return a pointer to
+ * the string ".". If path is a null pointer or points to an empty string,
+ * dirname() shall return a pointer to the string "." .
+ *
+ * The `git_path_dirname` implementation is thread safe. The returned
+ * string must be manually free'd.
+ *
+ * The `git_path_dirname_r` implementation writes the dirname to a `git_buf`
+ * if the buffer pointer is not NULL.
+ * It returns an error code < 0 if there is an allocation error, otherwise
+ * the length of the dirname (which will be > 0).
+ */
+extern char *git_path_dirname(const char *path);
+extern int git_path_dirname_r(git_buf *buffer, const char *path);
+
+/*
+ * This function returns the basename of the file, which is the last
+ * part of its full name given by fname, with the drive letter and
+ * leading directories stripped off. For example, the basename of
+ * c:/foo/bar/file.ext is file.ext, and the basename of a:foo is foo.
+ *
+ * Trailing slashes and backslashes are significant: the basename of
+ * c:/foo/bar/ is an empty string after the rightmost slash.
+ *
+ * The `git_path_basename` implementation is thread safe. The returned
+ * string must be manually free'd.
+ *
+ * The `git_path_basename_r` implementation writes the basename to a `git_buf`.
+ * It returns an error code < 0 if there is an allocation error, otherwise
+ * the length of the basename (which will be >= 0).
+ */
+extern char *git_path_basename(const char *path);
+extern int git_path_basename_r(git_buf *buffer, const char *path);
+
+/* Return the offset of the start of the basename.  Unlike the other
+ * basename functions, this returns 0 if the path is empty.
+ */
+extern size_t git_path_basename_offset(git_buf *buffer);
+
+extern const char *git_path_topdir(const char *path);
+
+/**
+ * Find offset to root of path if path has one.
+ *
+ * This will return a number >= 0 which is the offset to the start of the
+ * path, if the path is rooted (i.e. "/rooted/path" returns 0 and
+ * "c:/windows/rooted/path" returns 2).  If the path is not rooted, this
+ * returns -1.
+ */
+extern int git_path_root(const char *path);
+
+/**
+ * Ensure path has a trailing '/'.
+ */
+extern int git_path_to_dir(git_buf *path);
+
+/**
+ * Ensure string has a trailing '/' if there is space for it.
+ */
+extern void git_path_string_to_dir(char* path, size_t size);
+
+/**
+ * Taken from git.git; returns nonzero if the given path is "." or "..".
+ */
+GIT_INLINE(int) git_path_is_dot_or_dotdot(const char *name)
+{
+	return (name[0] == '.' &&
+			  (name[1] == '\0' ||
+				(name[1] == '.' && name[2] == '\0')));
+}
+
+#ifdef GIT_WIN32
+GIT_INLINE(int) git_path_is_dot_or_dotdotW(const wchar_t *name)
+{
+	return (name[0] == L'.' &&
+			  (name[1] == L'\0' ||
+				(name[1] == L'.' && name[2] == L'\0')));
+}
+
+#define git_path_is_absolute(p) \
+	(git__isalpha((p)[0]) && (p)[1] == ':' && ((p)[2] == '\\' || (p)[2] == '/'))
+
+#define git_path_is_dirsep(p) \
+	((p) == '/' || (p) == '\\')
+
+/**
+ * Convert backslashes in path to forward slashes.
+ */
+GIT_INLINE(void) git_path_mkposix(char *path)
+{
+	while (*path) {
+		if (*path == '\\')
+			*path = '/';
+
+		path++;
+	}
+}
+#else
+#	define git_path_mkposix(p) /* blank */
+
+#define git_path_is_absolute(p) \
+	((p)[0] == '/')
+
+#define git_path_is_dirsep(p) \
+	((p) == '/')
+
+#endif
+
+/**
+ * Check if string is a relative path (i.e. starts with "./" or "../")
+ */
+GIT_INLINE(int) git_path_is_relative(const char *p)
+{
+	return (p[0] == '.' && (p[1] == '/' || (p[1] == '.' && p[2] == '/')));
+}
+
+/**
+ * Check if string is at end of path segment (i.e. looking at '/' or '\0')
+ */
+GIT_INLINE(int) git_path_at_end_of_segment(const char *p)
+{
+	return !*p || *p == '/';
+}
+
+extern int git__percent_decode(git_buf *decoded_out, const char *input);
+
+/**
+ * Extract path from file:// URL.
+ */
+extern int git_path_fromurl(git_buf *local_path_out, const char *file_url);
+
+
+/**
+ * Path filesystem utils
+ *
+ * These are path utilities that actually access the filesystem.
+ */
+
+/**
+ * Check if a file exists and can be accessed.
+ * @return true or false
+ */
+extern bool git_path_exists(const char *path);
+
+/**
+ * Check if the given path points to a directory.
+ * @return true or false
+ */
+extern bool git_path_isdir(const char *path);
+
+/**
+ * Check if the given path points to a regular file.
+ * @return true or false
+ */
+extern bool git_path_isfile(const char *path);
+
+/**
+ * Check if the given path points to a symbolic link.
+ * @return true or false
+ */
+extern bool git_path_islink(const char *path);
+
+/**
+ * Check if the given path is a directory, and is empty.
+ */
+extern bool git_path_is_empty_dir(const char *path);
+
+/**
+ * Stat a file and/or link and set error if needed.
+ */
+extern int git_path_lstat(const char *path, struct stat *st);
+
+/**
+ * Check if the parent directory contains the item.
+ *
+ * @param dir Directory to check.
+ * @param item Item that might be in the directory.
+ * @return 0 if item exists in directory, <0 otherwise.
+ */
+extern bool git_path_contains(git_buf *dir, const char *item);
+
+/**
+ * Check if the given path contains the given subdirectory.
+ *
+ * @param parent Directory path that might contain subdir
+ * @param subdir Subdirectory name to look for in parent
+ * @return true if subdirectory exists, false otherwise.
+ */
+extern bool git_path_contains_dir(git_buf *parent, const char *subdir);
+
+/**
+ * Determine the common directory length between two paths, including
+ * the final path separator.  For example, given paths 'a/b/c/1.txt
+ * and 'a/b/c/d/2.txt', the common directory is 'a/b/c/', and this
+ * will return the length of the string 'a/b/c/', which is 6.
+ *
+ * @param one The first path
+ * @param two The second path
+ * @return The length of the common directory
+ */
+extern size_t git_path_common_dirlen(const char *one, const char *two);
+
+/**
+ * Make the path relative to the given parent path.
+ *
+ * @param path The path to make relative
+ * @param parent The parent path to make path relative to
+ * @return 0 if path was made relative, GIT_ENOTFOUND
+ *         if there was not common root between the paths,
+ *         or <0.
+ */
+extern int git_path_make_relative(git_buf *path, const char *parent);
+
+/**
+ * Check if the given path contains the given file.
+ *
+ * @param dir Directory path that might contain file
+ * @param file File name to look for in parent
+ * @return true if file exists, false otherwise.
+ */
+extern bool git_path_contains_file(git_buf *dir, const char *file);
+
+/**
+ * Prepend base to unrooted path or just copy path over.
+ *
+ * This will optionally return the index into the path where the "root"
+ * is, either the end of the base directory prefix or the path root.
+ */
+extern int git_path_join_unrooted(
+	git_buf *path_out, const char *path, const char *base, ssize_t *root_at);
+
+/**
+ * Removes multiple occurrences of '/' in a row, squashing them into a
+ * single '/'.
+ */
+extern void git_path_squash_slashes(git_buf *path);
+
+/**
+ * Clean up path, prepending base if it is not already rooted.
+ */
+extern int git_path_prettify(git_buf *path_out, const char *path, const char *base);
+
+/**
+ * Clean up path, prepending base if it is not already rooted and
+ * appending a slash.
+ */
+extern int git_path_prettify_dir(git_buf *path_out, const char *path, const char *base);
+
+/**
+ * Get a directory from a path.
+ *
+ * If path is a directory, this acts like `git_path_prettify_dir`
+ * (cleaning up path and appending a '/').  If path is a normal file,
+ * this prettifies it, then removed the filename a la dirname and
+ * appends the trailing '/'.  If the path does not exist, it is
+ * treated like a regular filename.
+ */
+extern int git_path_find_dir(git_buf *dir, const char *path, const char *base);
+
+/**
+ * Resolve relative references within a path.
+ *
+ * This eliminates "./" and "../" relative references inside a path,
+ * as well as condensing multiple slashes into single ones.  It will
+ * not touch the path before the "ceiling" length.
+ *
+ * Additionally, this will recognize an "c:/" drive prefix or a "xyz://" URL
+ * prefix and not touch that part of the path.
+ */
+extern int git_path_resolve_relative(git_buf *path, size_t ceiling);
+
+/**
+ * Apply a relative path to base path.
+ *
+ * Note that the base path could be a filename or a URL and this
+ * should still work.  The relative path is walked segment by segment
+ * with three rules: series of slashes will be condensed to a single
+ * slash, "." will be eaten with no change, and ".." will remove a
+ * segment from the base path.
+ */
+extern int git_path_apply_relative(git_buf *target, const char *relpath);
+
+enum {
+	GIT_PATH_DIR_IGNORE_CASE = (1u << 0),
+	GIT_PATH_DIR_PRECOMPOSE_UNICODE = (1u << 1),
+	GIT_PATH_DIR_INCLUDE_DOT_AND_DOTDOT = (1u << 2),
+};
+
+/**
+ * Walk each directory entry, except '.' and '..', calling fn(state).
+ *
+ * @param pathbuf Buffer the function reads the initial directory
+ * 		path from, and updates with each successive entry's name.
+ * @param flags Combination of GIT_PATH_DIR flags.
+ * @param callback Callback for each entry. Passed the `payload` and each
+ *		successive path inside the directory as a full path.  This may
+ *		safely append text to the pathbuf if needed.  Return non-zero to
+ *		cancel iteration (and return value will be propagated back).
+ * @param payload Passed to callback as first argument.
+ * @return 0 on success or error code from OS error or from callback
+ */
+extern int git_path_direach(
+	git_buf *pathbuf,
+	uint32_t flags,
+	int (*callback)(void *payload, git_buf *path),
+	void *payload);
+
+/**
+ * Sort function to order two paths
+ */
+extern int git_path_cmp(
+	const char *name1, size_t len1, int isdir1,
+	const char *name2, size_t len2, int isdir2,
+	int (*compare)(const char *, const char *, size_t));
+
+/**
+ * Invoke callback up path directory by directory until the ceiling is
+ * reached (inclusive of a final call at the root_path).
+ *
+ * Returning anything other than 0 from the callback function
+ * will stop the iteration and propagate the error to the caller.
+ *
+ * @param pathbuf Buffer the function reads the directory from and
+ *		and updates with each successive name.
+ * @param ceiling Prefix of path at which to stop walking up.  If NULL,
+ *		this will walk all the way up to the root.  If not a prefix of
+ *		pathbuf, the callback will be invoked a single time on the
+ *		original input path.
+ * @param callback Function to invoke on each path.  Passed the `payload`
+ *		and the buffer containing the current path.  The path should not
+ *		be modified in any way. Return non-zero to stop iteration.
+ * @param payload Passed to fn as the first ath.
+ */
+extern int git_path_walk_up(
+	git_buf *pathbuf,
+	const char *ceiling,
+	int (*callback)(void *payload, const char *path),
+	void *payload);
+
+
+enum { GIT_PATH_NOTEQUAL = 0, GIT_PATH_EQUAL = 1, GIT_PATH_PREFIX = 2 };
+
+/*
+ * Determines if a path is equal to or potentially a child of another.
+ * @param parent The possible parent
+ * @param child The possible child
+ */
+GIT_INLINE(int) git_path_equal_or_prefixed(
+	const char *parent,
+	const char *child,
+	ssize_t *prefixlen)
+{
+	const char *p = parent, *c = child;
+	int lastslash = 0;
+
+	while (*p && *c) {
+		lastslash = (*p == '/');
+
+		if (*p++ != *c++)
+			return GIT_PATH_NOTEQUAL;
+	}
+
+	if (*p != '\0')
+		return GIT_PATH_NOTEQUAL;
+
+	if (*c == '\0') {
+		if (prefixlen)
+			*prefixlen = p - parent;
+
+		return GIT_PATH_EQUAL;
+	}
+
+	if (*c == '/' || lastslash) {
+		if (prefixlen)
+			*prefixlen = (p - parent) - lastslash;
+
+		return GIT_PATH_PREFIX;
+	}
+
+	return GIT_PATH_NOTEQUAL;
+}
+
+/* translate errno to libgit2 error code and set error message */
+extern int git_path_set_error(
+	int errno_value, const char *path, const char *action);
+
+/* check if non-ascii characters are present in filename */
+extern bool git_path_has_non_ascii(const char *path, size_t pathlen);
+
+#define GIT_PATH_REPO_ENCODING "UTF-8"
+
+#ifdef __APPLE__
+#define GIT_PATH_NATIVE_ENCODING "UTF-8-MAC"
+#else
+#define GIT_PATH_NATIVE_ENCODING "UTF-8"
+#endif
+
+#ifdef GIT_USE_ICONV
+
+#include <iconv.h>
+
+typedef struct {
+	iconv_t map;
+	git_buf buf;
+} git_path_iconv_t;
+
+#define GIT_PATH_ICONV_INIT { (iconv_t)-1, GIT_BUF_INIT }
+
+/* Init iconv data for converting decomposed UTF-8 to precomposed */
+extern int git_path_iconv_init_precompose(git_path_iconv_t *ic);
+
+/* Clear allocated iconv data */
+extern void git_path_iconv_clear(git_path_iconv_t *ic);
+
+/*
+ * Rewrite `in` buffer using iconv map if necessary, replacing `in`
+ * pointer internal iconv buffer if rewrite happened.  The `in` pointer
+ * will be left unchanged if no rewrite was needed.
+ */
+extern int git_path_iconv(git_path_iconv_t *ic, const char **in, size_t *inlen);
+
+#endif /* GIT_USE_ICONV */
+
+extern bool git_path_does_fs_decompose_unicode(const char *root);
+
+
+typedef struct git_path_diriter git_path_diriter;
+
+#if defined(GIT_WIN32) && !defined(__MINGW32__)
+
+struct git_path_diriter
+{
+	git_win32_path path;
+	size_t parent_len;
+
+	git_buf path_utf8;
+	size_t parent_utf8_len;
+
+	HANDLE handle;
+
+	unsigned int flags;
+
+	WIN32_FIND_DATAW current;
+	unsigned int needs_next;
+};
+
+#define GIT_PATH_DIRITER_INIT { {0}, 0, GIT_BUF_INIT, 0, INVALID_HANDLE_VALUE }
+
+#else
+
+struct git_path_diriter
+{
+	git_buf path;
+	size_t parent_len;
+
+	unsigned int flags;
+
+	DIR *dir;
+
+#ifdef GIT_USE_ICONV
+	git_path_iconv_t ic;
+#endif
+};
+
+#define GIT_PATH_DIRITER_INIT { GIT_BUF_INIT }
+
+#endif
+
+/**
+ * Initialize a directory iterator.
+ *
+ * @param diriter Pointer to a diriter structure that will be setup.
+ * @param path The path that will be iterated over
+ * @param flags Directory reader flags
+ * @return 0 or an error code
+ */
+extern int git_path_diriter_init(
+	git_path_diriter *diriter,
+	const char *path,
+	unsigned int flags);
+
+/**
+ * Advance the directory iterator.  Will return GIT_ITEROVER when
+ * the iteration has completed successfully.
+ *
+ * @param diriter The directory iterator
+ * @return 0, GIT_ITEROVER, or an error code
+ */
+extern int git_path_diriter_next(git_path_diriter *diriter);
+
+/**
+ * Returns the file name of the current item in the iterator.
+ *
+ * @param out Pointer to store the path in
+ * @param out_len Pointer to store the length of the path in
+ * @param diriter The directory iterator
+ * @return 0 or an error code
+ */
+extern int git_path_diriter_filename(
+	const char **out,
+	size_t *out_len,
+	git_path_diriter *diriter);
+
+/**
+ * Returns the full path of the current item in the iterator; that
+ * is the current filename plus the path of the directory that the
+ * iterator was constructed with.
+ *
+ * @param out Pointer to store the path in
+ * @param out_len Pointer to store the length of the path in
+ * @param diriter The directory iterator
+ * @return 0 or an error code
+ */
+extern int git_path_diriter_fullpath(
+	const char **out,
+	size_t *out_len,
+	git_path_diriter *diriter);
+
+/**
+ * Performs an `lstat` on the current item in the iterator.
+ *
+ * @param out Pointer to store the stat data in
+ * @param diriter The directory iterator
+ * @return 0 or an error code
+ */
+extern int git_path_diriter_stat(struct stat *out, git_path_diriter *diriter);
+
+/**
+ * Closes the directory iterator.
+ *
+ * @param diriter The directory iterator
+ */
+extern void git_path_diriter_free(git_path_diriter *diriter);
+
+/**
+ * Load all directory entries (except '.' and '..') into a vector.
+ *
+ * For cases where `git_path_direach()` is not appropriate, this
+ * allows you to load the filenames in a directory into a vector
+ * of strings. That vector can then be sorted, iterated, or whatever.
+ * Remember to free alloc of the allocated strings when you are done.
+ *
+ * @param contents Vector to fill with directory entry names.
+ * @param path The directory to read from.
+ * @param prefix_len When inserting entries, the trailing part of path
+ * 		will be prefixed after this length.  I.e. given path "/a/b" and
+ * 		prefix_len 3, the entries will look like "b/e1", "b/e2", etc.
+ * @param flags Combination of GIT_PATH_DIR flags.
+ */
+extern int git_path_dirload(
+	git_vector *contents,
+	const char *path,
+	size_t prefix_len,
+	uint32_t flags);
+
+
+/* Used for paths to repositories on the filesystem */
+extern bool git_path_is_local_file_url(const char *file_url);
+extern int git_path_from_url_or_path(git_buf *local_path_out, const char *url_or_path);
+
+/* Flags to determine path validity in `git_path_isvalid` */
+#define GIT_PATH_REJECT_TRAVERSAL          (1 << 0)
+#define GIT_PATH_REJECT_DOT_GIT            (1 << 1)
+#define GIT_PATH_REJECT_SLASH              (1 << 2)
+#define GIT_PATH_REJECT_BACKSLASH          (1 << 3)
+#define GIT_PATH_REJECT_TRAILING_DOT       (1 << 4)
+#define GIT_PATH_REJECT_TRAILING_SPACE     (1 << 5)
+#define GIT_PATH_REJECT_TRAILING_COLON     (1 << 6)
+#define GIT_PATH_REJECT_DOS_PATHS          (1 << 7)
+#define GIT_PATH_REJECT_NT_CHARS           (1 << 8)
+#define GIT_PATH_REJECT_DOT_GIT_LITERAL    (1 << 9)
+#define GIT_PATH_REJECT_DOT_GIT_HFS        (1 << 10)
+#define GIT_PATH_REJECT_DOT_GIT_NTFS       (1 << 11)
+
+/* Default path safety for writing files to disk: since we use the
+ * Win32 "File Namespace" APIs ("\\?\") we need to protect from
+ * paths that the normal Win32 APIs would not write.
+ */
+#ifdef GIT_WIN32
+# define GIT_PATH_REJECT_FILESYSTEM_DEFAULTS \
+	GIT_PATH_REJECT_TRAVERSAL | \
+	GIT_PATH_REJECT_BACKSLASH | \
+	GIT_PATH_REJECT_TRAILING_DOT | \
+	GIT_PATH_REJECT_TRAILING_SPACE | \
+	GIT_PATH_REJECT_TRAILING_COLON | \
+	GIT_PATH_REJECT_DOS_PATHS | \
+	GIT_PATH_REJECT_NT_CHARS
+#else
+# define GIT_PATH_REJECT_FILESYSTEM_DEFAULTS \
+	GIT_PATH_REJECT_TRAVERSAL
+#endif
+
+ /* Paths that should never be written into the working directory. */
+#define GIT_PATH_REJECT_WORKDIR_DEFAULTS \
+	GIT_PATH_REJECT_FILESYSTEM_DEFAULTS | GIT_PATH_REJECT_DOT_GIT
+
+/* Paths that should never be written to the index. */
+#define GIT_PATH_REJECT_INDEX_DEFAULTS \
+	GIT_PATH_REJECT_TRAVERSAL | GIT_PATH_REJECT_DOT_GIT
+
+/*
+ * Determine whether a path is a valid git path or not - this must not contain
+ * a '.' or '..' component, or a component that is ".git" (in any case).
+ *
+ * `repo` is optional.  If specified, it will be used to determine the short
+ * path name to reject (if `GIT_PATH_REJECT_DOS_SHORTNAME` is specified),
+ * in addition to the default of "git~1".
+ */
+extern bool git_path_isvalid(
+	git_repository *repo,
+	const char *path,
+	uint16_t mode,
+	unsigned int flags);
+
+/**
+ * Convert any backslashes into slashes
+ */
+int git_path_normalize_slashes(git_buf *out, const char *path);
+
+/**
+ * Check whether a path component corresponds to a .gitmodules file
+ *
+ * @param name the path component to check
+ * @param len the length of `name`
+ */
+extern int git_path_is_dotgit_modules(const char *name, size_t len);
+
+/**
+ * Check whether a path component corresponds to a .gitmodules file in NTFS
+ *
+ * @param name the path component to check
+ * @param len the length of `name`
+ */
+extern int git_path_is_ntfs_dotgit_modules(const char *name, size_t len);
+
+/**
+ * Check whether a path component corresponds to a .gitmodules file in HFS+
+ *
+ * @param name the path component to check
+ * @param len the length of `name`
+ */
+extern int git_path_is_hfs_dotgit_modules(const char *name, size_t len);
+
+/**
+ * Check whether a path component corresponds to a .gitignore file
+ *
+ * @param name the path component to check
+ * @param len the length of `name`
+ */
+extern int git_path_is_dotgit_ignore(const char *name, size_t len);
+
+/**
+ * Check whether a path component corresponds to a .gitignore file in NTFS
+ *
+ * @param name the path component to check
+ * @param len the length of `name`
+ */
+extern int git_path_is_ntfs_dotgit_ignore(const char *name, size_t len);
+
+/**
+ * Check whether a path component corresponds to a .gitignore file in HFS+
+ *
+ * @param name the path component to check
+ * @param len the length of `name`
+ */
+extern int git_path_is_hfs_dotgit_ignore(const char *name, size_t len);
+
+/**
+ * Check whether a path component corresponds to a .gitignore file
+ *
+ * @param name the path component to check
+ * @param len the length of `name`
+ */
+extern int git_path_is_dotgit_attributes(const char *name, size_t len);
+
+/**
+ * Check whether a path component corresponds to a .gitattributes file in NTFS
+ *
+ * @param name the path component to check
+ * @param len the length of `name`
+ */
+extern int git_path_is_ntfs_dotgit_attributes(const char *name, size_t len);
+
+/**
+ * Check whether a path component corresponds to a .gitattributes file in HFS+
+ *
+ * @param name the path component to check
+ * @param len the length of `name`
+ */
+extern int git_path_is_hfs_dotgit_attributes(const char *name, size_t len);
+
+#endif

vendor/libgit2-sys/libgit2/src/pathspec.c

diff --git a/vendor/libgit2-sys/libgit2/src/pathspec.c b/vendor/libgit2-sys/libgit2/src/pathspec.c
new file mode 100644
index 0000000..998b6fb
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/pathspec.c
@@ -0,0 +1,721 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "pathspec.h"
+
+#include "git2/pathspec.h"
+#include "git2/diff.h"
+#include "buf_text.h"
+#include "attr_file.h"
+#include "iterator.h"
+#include "repository.h"
+#include "index.h"
+#include "bitvec.h"
+#include "diff.h"
+
+/* what is the common non-wildcard prefix for all items in the pathspec */
+char *git_pathspec_prefix(const git_strarray *pathspec)
+{
+	git_buf prefix = GIT_BUF_INIT;
+	const char *scan;
+
+	if (!pathspec || !pathspec->count ||
+		git_buf_text_common_prefix(&prefix, pathspec) < 0)
+		return NULL;
+
+	/* diff prefix will only be leading non-wildcards */
+	for (scan = prefix.ptr; *scan; ++scan) {
+		if (git__iswildcard(*scan) &&
+			(scan == prefix.ptr || (*(scan - 1) != '\\')))
+			break;
+	}
+	git_buf_truncate(&prefix, scan - prefix.ptr);
+
+	if (prefix.size <= 0) {
+		git_buf_free(&prefix);
+		return NULL;
+	}
+
+	git_buf_text_unescape(&prefix);
+
+	return git_buf_detach(&prefix);
+}
+
+/* is there anything in the spec that needs to be filtered on */
+bool git_pathspec_is_empty(const git_strarray *pathspec)
+{
+	size_t i;
+
+	if (pathspec == NULL)
+		return true;
+
+	for (i = 0; i < pathspec->count; ++i) {
+		const char *str = pathspec->strings[i];
+
+		if (str && str[0])
+			return false;
+	}
+
+	return true;
+}
+
+/* build a vector of fnmatch patterns to evaluate efficiently */
+int git_pathspec__vinit(
+	git_vector *vspec, const git_strarray *strspec, git_pool *strpool)
+{
+	size_t i;
+
+	memset(vspec, 0, sizeof(*vspec));
+
+	if (git_pathspec_is_empty(strspec))
+		return 0;
+
+	if (git_vector_init(vspec, strspec->count, NULL) < 0)
+		return -1;
+
+	for (i = 0; i < strspec->count; ++i) {
+		int ret;
+		const char *pattern = strspec->strings[i];
+		git_attr_fnmatch *match = git__calloc(1, sizeof(git_attr_fnmatch));
+		if (!match)
+			return -1;
+
+		match->flags = GIT_ATTR_FNMATCH_ALLOWSPACE |
+			GIT_ATTR_FNMATCH_ALLOWNEG | GIT_ATTR_FNMATCH_NOLEADINGDIR;
+
+		ret = git_attr_fnmatch__parse(match, strpool, NULL, &pattern);
+		if (ret == GIT_ENOTFOUND) {
+			git__free(match);
+			continue;
+		} else if (ret < 0) {
+			git__free(match);
+			return ret;
+		}
+
+		if (git_vector_insert(vspec, match) < 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+/* free data from the pathspec vector */
+void git_pathspec__vfree(git_vector *vspec)
+{
+	git_vector_free_deep(vspec);
+}
+
+struct pathspec_match_context {
+	int fnmatch_flags;
+	int (*strcomp)(const char *, const char *);
+	int (*strncomp)(const char *, const char *, size_t);
+};
+
+static void pathspec_match_context_init(
+	struct pathspec_match_context *ctxt,
+	bool disable_fnmatch,
+	bool casefold)
+{
+	if (disable_fnmatch)
+		ctxt->fnmatch_flags = -1;
+	else if (casefold)
+		ctxt->fnmatch_flags = FNM_CASEFOLD;
+	else
+		ctxt->fnmatch_flags = 0;
+
+	if (casefold) {
+		ctxt->strcomp  = git__strcasecmp;
+		ctxt->strncomp = git__strncasecmp;
+	} else {
+		ctxt->strcomp  = git__strcmp;
+		ctxt->strncomp = git__strncmp;
+	}
+}
+
+static int pathspec_match_one(
+	const git_attr_fnmatch *match,
+	struct pathspec_match_context *ctxt,
+	const char *path)
+{
+	int result = (match->flags & GIT_ATTR_FNMATCH_MATCH_ALL) ? 0 : FNM_NOMATCH;
+
+	if (result == FNM_NOMATCH)
+		result = ctxt->strcomp(match->pattern, path) ? FNM_NOMATCH : 0;
+
+	if (ctxt->fnmatch_flags >= 0 && result == FNM_NOMATCH)
+		result = p_fnmatch(match->pattern, path, ctxt->fnmatch_flags);
+
+	/* if we didn't match, look for exact dirname prefix match */
+	if (result == FNM_NOMATCH &&
+		(match->flags & GIT_ATTR_FNMATCH_HASWILD) == 0 &&
+		ctxt->strncomp(path, match->pattern, match->length) == 0 &&
+		path[match->length] == '/')
+		result = 0;
+
+	/* if we didn't match and this is a negative match, check for exact
+	 * match of filename with leading '!'
+	 */
+	if (result == FNM_NOMATCH &&
+		(match->flags & GIT_ATTR_FNMATCH_NEGATIVE) != 0 &&
+		*path == '!' &&
+		ctxt->strncomp(path + 1, match->pattern, match->length) == 0 &&
+		(!path[match->length + 1] || path[match->length + 1] == '/'))
+		return 1;
+
+	if (result == 0)
+		return (match->flags & GIT_ATTR_FNMATCH_NEGATIVE) ? 0 : 1;
+	return -1;
+}
+
+static int git_pathspec__match_at(
+	size_t *matched_at,
+	const git_vector *vspec,
+	struct pathspec_match_context *ctxt,
+	const char *path0,
+	const char *path1)
+{
+	int result = GIT_ENOTFOUND;
+	size_t i = 0;
+	const git_attr_fnmatch *match;
+
+	git_vector_foreach(vspec, i, match) {
+		if (path0 && (result = pathspec_match_one(match, ctxt, path0)) >= 0)
+			break;
+		if (path1 && (result = pathspec_match_one(match, ctxt, path1)) >= 0)
+			break;
+	}
+
+	*matched_at = i;
+	return result;
+}
+
+/* match a path against the vectorized pathspec */
+bool git_pathspec__match(
+	const git_vector *vspec,
+	const char *path,
+	bool disable_fnmatch,
+	bool casefold,
+	const char **matched_pathspec,
+	size_t *matched_at)
+{
+	int result;
+	size_t pos;
+	struct pathspec_match_context ctxt;
+
+	if (matched_pathspec)
+		*matched_pathspec = NULL;
+	if (matched_at)
+		*matched_at = GIT_PATHSPEC_NOMATCH;
+
+	if (!vspec || !vspec->length)
+		return true;
+
+	pathspec_match_context_init(&ctxt, disable_fnmatch, casefold);
+
+	result = git_pathspec__match_at(&pos, vspec, &ctxt, path, NULL);
+	if (result >= 0) {
+		if (matched_pathspec) {
+			const git_attr_fnmatch *match = git_vector_get(vspec, pos);
+			*matched_pathspec = match->pattern;
+		}
+
+		if (matched_at)
+			*matched_at = pos;
+	}
+
+	return (result > 0);
+}
+
+
+int git_pathspec__init(git_pathspec *ps, const git_strarray *paths)
+{
+	int error = 0;
+
+	memset(ps, 0, sizeof(*ps));
+
+	ps->prefix = git_pathspec_prefix(paths);
+	git_pool_init(&ps->pool, 1);
+
+	if ((error = git_pathspec__vinit(&ps->pathspec, paths, &ps->pool)) < 0)
+		git_pathspec__clear(ps);
+
+	return error;
+}
+
+void git_pathspec__clear(git_pathspec *ps)
+{
+	git__free(ps->prefix);
+	git_pathspec__vfree(&ps->pathspec);
+	git_pool_clear(&ps->pool);
+	memset(ps, 0, sizeof(*ps));
+}
+
+int git_pathspec_new(git_pathspec **out, const git_strarray *pathspec)
+{
+	int error = 0;
+	git_pathspec *ps = git__malloc(sizeof(git_pathspec));
+	GITERR_CHECK_ALLOC(ps);
+
+	if ((error = git_pathspec__init(ps, pathspec)) < 0) {
+		git__free(ps);
+		return error;
+	}
+
+	GIT_REFCOUNT_INC(ps);
+	*out = ps;
+	return 0;
+}
+
+static void pathspec_free(git_pathspec *ps)
+{
+	git_pathspec__clear(ps);
+	git__free(ps);
+}
+
+void git_pathspec_free(git_pathspec *ps)
+{
+	if (!ps)
+		return;
+	GIT_REFCOUNT_DEC(ps, pathspec_free);
+}
+
+int git_pathspec_matches_path(
+	const git_pathspec *ps, uint32_t flags, const char *path)
+{
+	bool no_fnmatch = (flags & GIT_PATHSPEC_NO_GLOB) != 0;
+	bool casefold =  (flags & GIT_PATHSPEC_IGNORE_CASE) != 0;
+
+	assert(ps && path);
+
+	return (0 != git_pathspec__match(
+		&ps->pathspec, path, no_fnmatch, casefold, NULL, NULL));
+}
+
+static void pathspec_match_free(git_pathspec_match_list *m)
+{
+	if (!m)
+		return;
+
+	git_pathspec_free(m->pathspec);
+	m->pathspec = NULL;
+
+	git_array_clear(m->matches);
+	git_array_clear(m->failures);
+	git_pool_clear(&m->pool);
+	git__free(m);
+}
+
+static git_pathspec_match_list *pathspec_match_alloc(
+	git_pathspec *ps, int datatype)
+{
+	git_pathspec_match_list *m = git__calloc(1, sizeof(git_pathspec_match_list));
+	if (!m)
+		return NULL;
+
+	git_pool_init(&m->pool, 1);
+
+	/* need to keep reference to pathspec and increment refcount because
+	 * failures array stores pointers to the pattern strings of the
+	 * pathspec that had no matches
+	 */
+	GIT_REFCOUNT_INC(ps);
+	m->pathspec = ps;
+	m->datatype = datatype;
+
+	return m;
+}
+
+GIT_INLINE(size_t) pathspec_mark_pattern(git_bitvec *used, size_t pos)
+{
+	if (!git_bitvec_get(used, pos)) {
+		git_bitvec_set(used, pos, true);
+		return 1;
+	}
+
+	return 0;
+}
+
+static size_t pathspec_mark_remaining(
+	git_bitvec *used,
+	git_vector *patterns,
+	struct pathspec_match_context *ctxt,
+	size_t start,
+	const char *path0,
+	const char *path1)
+{
+	size_t count = 0;
+
+	if (path1 == path0)
+		path1 = NULL;
+
+	for (; start < patterns->length; ++start) {
+		const git_attr_fnmatch *pat = git_vector_get(patterns, start);
+
+		if (git_bitvec_get(used, start))
+			continue;
+
+		if (path0 && pathspec_match_one(pat, ctxt, path0) > 0)
+			count += pathspec_mark_pattern(used, start);
+		else if (path1 && pathspec_match_one(pat, ctxt, path1) > 0)
+			count += pathspec_mark_pattern(used, start);
+	}
+
+	return count;
+}
+
+static int pathspec_build_failure_array(
+	git_pathspec_string_array_t *failures,
+	git_vector *patterns,
+	git_bitvec *used,
+	git_pool *pool)
+{
+	size_t pos;
+	char **failed;
+	const git_attr_fnmatch *pat;
+
+	for (pos = 0; pos < patterns->length; ++pos) {
+		if (git_bitvec_get(used, pos))
+			continue;
+
+		if ((failed = git_array_alloc(*failures)) == NULL)
+			return -1;
+
+		pat = git_vector_get(patterns, pos);
+
+		if ((*failed = git_pool_strdup(pool, pat->pattern)) == NULL)
+			return -1;
+	}
+
+	return 0;
+}
+
+static int pathspec_match_from_iterator(
+	git_pathspec_match_list **out,
+	git_iterator *iter,
+	uint32_t flags,
+	git_pathspec *ps)
+{
+	int error = 0;
+	git_pathspec_match_list *m = NULL;
+	const git_index_entry *entry = NULL;
+	struct pathspec_match_context ctxt;
+	git_vector *patterns = &ps->pathspec;
+	bool find_failures = out && (flags & GIT_PATHSPEC_FIND_FAILURES) != 0;
+	bool failures_only = !out || (flags & GIT_PATHSPEC_FAILURES_ONLY) != 0;
+	size_t pos, used_ct = 0, found_files = 0;
+	git_index *index = NULL;
+	git_bitvec used_patterns;
+	char **file;
+
+	if (git_bitvec_init(&used_patterns, patterns->length) < 0)
+		return -1;
+
+	if (out) {
+		*out = m = pathspec_match_alloc(ps, PATHSPEC_DATATYPE_STRINGS);
+		GITERR_CHECK_ALLOC(m);
+	}
+
+	if ((error = git_iterator_reset_range(iter, ps->prefix, ps->prefix)) < 0)
+		goto done;
+
+	if (git_iterator_type(iter) == GIT_ITERATOR_TYPE_WORKDIR &&
+		(error = git_repository_index__weakptr(
+			&index, git_iterator_owner(iter))) < 0)
+		goto done;
+
+	pathspec_match_context_init(
+		&ctxt, (flags & GIT_PATHSPEC_NO_GLOB) != 0,
+		git_iterator_ignore_case(iter));
+
+	while (!(error = git_iterator_advance(&entry, iter))) {
+		/* search for match with entry->path */
+		int result = git_pathspec__match_at(
+			&pos, patterns, &ctxt, entry->path, NULL);
+
+		/* no matches for this path */
+		if (result < 0)
+			continue;
+
+		/* if result was a negative pattern match, then don't list file */
+		if (!result) {
+			used_ct += pathspec_mark_pattern(&used_patterns, pos);
+			continue;
+		}
+
+		/* check if path is ignored and untracked */
+		if (index != NULL &&
+			git_iterator_current_is_ignored(iter) &&
+			git_index__find_pos(NULL, index, entry->path, 0, GIT_INDEX_STAGE_ANY) < 0)
+			continue;
+
+		/* mark the matched pattern as used */
+		used_ct += pathspec_mark_pattern(&used_patterns, pos);
+		++found_files;
+
+		/* if find_failures is on, check if any later patterns also match */
+		if (find_failures && used_ct < patterns->length)
+			used_ct += pathspec_mark_remaining(
+				&used_patterns, patterns, &ctxt, pos + 1, entry->path, NULL);
+
+		/* if only looking at failures, exit early or just continue */
+		if (failures_only || !out) {
+			if (used_ct == patterns->length)
+				break;
+			continue;
+		}
+
+		/* insert matched path into matches array */
+		if ((file = (char **)git_array_alloc(m->matches)) == NULL ||
+			(*file = git_pool_strdup(&m->pool, entry->path)) == NULL) {
+			error = -1;
+			goto done;
+		}
+	}
+
+	if (error < 0 && error != GIT_ITEROVER)
+		goto done;
+	error = 0;
+
+	/* insert patterns that had no matches into failures array */
+	if (find_failures && used_ct < patterns->length &&
+		(error = pathspec_build_failure_array(
+			&m->failures, patterns, &used_patterns, &m->pool)) < 0)
+		goto done;
+
+	/* if every pattern failed to match, then we have failed */
+	if ((flags & GIT_PATHSPEC_NO_MATCH_ERROR) != 0 && !found_files) {
+		giterr_set(GITERR_INVALID, "no matching files were found");
+		error = GIT_ENOTFOUND;
+	}
+
+done:
+	git_bitvec_free(&used_patterns);
+
+	if (error < 0) {
+		pathspec_match_free(m);
+		if (out) *out = NULL;
+	}
+
+	return error;
+}
+
+static git_iterator_flag_t pathspec_match_iter_flags(uint32_t flags)
+{
+	git_iterator_flag_t f = 0;
+
+	if ((flags & GIT_PATHSPEC_IGNORE_CASE) != 0)
+		f |= GIT_ITERATOR_IGNORE_CASE;
+	else if ((flags & GIT_PATHSPEC_USE_CASE) != 0)
+		f |= GIT_ITERATOR_DONT_IGNORE_CASE;
+
+	return f;
+}
+
+int git_pathspec_match_workdir(
+	git_pathspec_match_list **out,
+	git_repository *repo,
+	uint32_t flags,
+	git_pathspec *ps)
+{
+	git_iterator *iter;
+	git_iterator_options iter_opts = GIT_ITERATOR_OPTIONS_INIT;
+	int error = 0;
+
+	assert(repo);
+
+	iter_opts.flags = pathspec_match_iter_flags(flags);
+
+	if (!(error = git_iterator_for_workdir(&iter, repo, NULL, NULL, &iter_opts))) {
+		error = pathspec_match_from_iterator(out, iter, flags, ps);
+		git_iterator_free(iter);
+	}
+
+	return error;
+}
+
+int git_pathspec_match_index(
+	git_pathspec_match_list **out,
+	git_index *index,
+	uint32_t flags,
+	git_pathspec *ps)
+{
+	git_iterator *iter;
+	git_iterator_options iter_opts = GIT_ITERATOR_OPTIONS_INIT;
+	int error = 0;
+
+	assert(index);
+
+	iter_opts.flags = pathspec_match_iter_flags(flags);
+
+	if (!(error = git_iterator_for_index(&iter, git_index_owner(index), index, &iter_opts))) {
+		error = pathspec_match_from_iterator(out, iter, flags, ps);
+		git_iterator_free(iter);
+	}
+
+	return error;
+}
+
+int git_pathspec_match_tree(
+	git_pathspec_match_list **out,
+	git_tree *tree,
+	uint32_t flags,
+	git_pathspec *ps)
+{
+	git_iterator *iter;
+	git_iterator_options iter_opts = GIT_ITERATOR_OPTIONS_INIT;
+	int error = 0;
+
+	assert(tree);
+
+	iter_opts.flags = pathspec_match_iter_flags(flags);
+
+	if (!(error = git_iterator_for_tree(&iter, tree, &iter_opts))) {
+		error = pathspec_match_from_iterator(out, iter, flags, ps);
+		git_iterator_free(iter);
+	}
+
+	return error;
+}
+
+int git_pathspec_match_diff(
+	git_pathspec_match_list **out,
+	git_diff *diff,
+	uint32_t flags,
+	git_pathspec *ps)
+{
+	int error = 0;
+	git_pathspec_match_list *m = NULL;
+	struct pathspec_match_context ctxt;
+	git_vector *patterns = &ps->pathspec;
+	bool find_failures = out && (flags & GIT_PATHSPEC_FIND_FAILURES) != 0;
+	bool failures_only = !out || (flags & GIT_PATHSPEC_FAILURES_ONLY) != 0;
+	size_t i, pos, used_ct = 0, found_deltas = 0;
+	const git_diff_delta *delta, **match;
+	git_bitvec used_patterns;
+
+	assert(diff);
+
+	if (git_bitvec_init(&used_patterns, patterns->length) < 0)
+		return -1;
+
+	if (out) {
+		*out = m = pathspec_match_alloc(ps, PATHSPEC_DATATYPE_DIFF);
+		GITERR_CHECK_ALLOC(m);
+	}
+
+	pathspec_match_context_init(
+		&ctxt, (flags & GIT_PATHSPEC_NO_GLOB) != 0,
+		git_diff_is_sorted_icase(diff));
+
+	git_vector_foreach(&diff->deltas, i, delta) {
+		/* search for match with delta */
+		int result = git_pathspec__match_at(
+			&pos, patterns, &ctxt, delta->old_file.path, delta->new_file.path);
+
+		/* no matches for this path */
+		if (result < 0)
+			continue;
+
+		/* mark the matched pattern as used */
+		used_ct += pathspec_mark_pattern(&used_patterns, pos);
+
+		/* if result was a negative pattern match, then don't list file */
+		if (!result)
+			continue;
+
+		++found_deltas;
+
+		/* if find_failures is on, check if any later patterns also match */
+		if (find_failures && used_ct < patterns->length)
+			used_ct += pathspec_mark_remaining(
+				&used_patterns, patterns, &ctxt, pos + 1,
+				delta->old_file.path, delta->new_file.path);
+
+		/* if only looking at failures, exit early or just continue */
+		if (failures_only || !out) {
+			if (used_ct == patterns->length)
+				break;
+			continue;
+		}
+
+		/* insert matched delta into matches array */
+		if (!(match = (const git_diff_delta **)git_array_alloc(m->matches))) {
+			error = -1;
+			goto done;
+		} else {
+			*match = delta;
+		}
+	}
+
+	/* insert patterns that had no matches into failures array */
+	if (find_failures && used_ct < patterns->length &&
+		(error = pathspec_build_failure_array(
+			&m->failures, patterns, &used_patterns, &m->pool)) < 0)
+		goto done;
+
+	/* if every pattern failed to match, then we have failed */
+	if ((flags & GIT_PATHSPEC_NO_MATCH_ERROR) != 0 && !found_deltas) {
+		giterr_set(GITERR_INVALID, "no matching deltas were found");
+		error = GIT_ENOTFOUND;
+	}
+
+done:
+	git_bitvec_free(&used_patterns);
+
+	if (error < 0) {
+		pathspec_match_free(m);
+		if (out) *out = NULL;
+	}
+
+	return error;
+}
+
+void git_pathspec_match_list_free(git_pathspec_match_list *m)
+{
+	if (m)
+		pathspec_match_free(m);
+}
+
+size_t git_pathspec_match_list_entrycount(
+	const git_pathspec_match_list *m)
+{
+	return m ? git_array_size(m->matches) : 0;
+}
+
+const char *git_pathspec_match_list_entry(
+	const git_pathspec_match_list *m, size_t pos)
+{
+	if (!m || m->datatype != PATHSPEC_DATATYPE_STRINGS ||
+		!git_array_valid_index(m->matches, pos))
+		return NULL;
+
+	return *((const char **)git_array_get(m->matches, pos));
+}
+
+const git_diff_delta *git_pathspec_match_list_diff_entry(
+	const git_pathspec_match_list *m, size_t pos)
+{
+	if (!m || m->datatype != PATHSPEC_DATATYPE_DIFF ||
+		!git_array_valid_index(m->matches, pos))
+		return NULL;
+
+	return *((const git_diff_delta **)git_array_get(m->matches, pos));
+}
+
+size_t git_pathspec_match_list_failed_entrycount(
+	const git_pathspec_match_list *m)
+{
+	return m ? git_array_size(m->failures) : 0;
+}
+
+const char * git_pathspec_match_list_failed_entry(
+	const git_pathspec_match_list *m, size_t pos)
+{
+	char **entry = m ? git_array_get(m->failures, pos) : NULL;
+
+	return entry ? *entry : NULL;
+}

vendor/libgit2-sys/libgit2/src/pathspec.h

diff --git a/vendor/libgit2-sys/libgit2/src/pathspec.h b/vendor/libgit2-sys/libgit2/src/pathspec.h
new file mode 100644
index 0000000..c4d1a83
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/pathspec.h
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_pathspec_h__
+#define INCLUDE_pathspec_h__
+
+#include "common.h"
+
+#include "git2/pathspec.h"
+#include "buffer.h"
+#include "vector.h"
+#include "pool.h"
+#include "array.h"
+
+/* public compiled pathspec */
+struct git_pathspec {
+	git_refcount rc;
+	char *prefix;
+	git_vector pathspec;
+	git_pool pool;
+};
+
+enum {
+	PATHSPEC_DATATYPE_STRINGS = 0,
+	PATHSPEC_DATATYPE_DIFF = 1,
+};
+
+typedef git_array_t(char *) git_pathspec_string_array_t;
+
+/* public interface to pathspec matching */
+struct git_pathspec_match_list {
+	git_pathspec *pathspec;
+	git_array_t(void *) matches;
+	git_pathspec_string_array_t failures;
+	git_pool pool;
+	int datatype;
+};
+
+/* what is the common non-wildcard prefix for all items in the pathspec */
+extern char *git_pathspec_prefix(const git_strarray *pathspec);
+
+/* is there anything in the spec that needs to be filtered on */
+extern bool git_pathspec_is_empty(const git_strarray *pathspec);
+
+/* build a vector of fnmatch patterns to evaluate efficiently */
+extern int git_pathspec__vinit(
+	git_vector *vspec, const git_strarray *strspec, git_pool *strpool);
+
+/* free data from the pathspec vector */
+extern void git_pathspec__vfree(git_vector *vspec);
+
+#define GIT_PATHSPEC_NOMATCH ((size_t)-1)
+
+/*
+ * Match a path against the vectorized pathspec.
+ * The matched pathspec is passed back into the `matched_pathspec` parameter,
+ * unless it is passed as NULL by the caller.
+ */
+extern bool git_pathspec__match(
+	const git_vector *vspec,
+	const char *path,
+	bool disable_fnmatch,
+	bool casefold,
+	const char **matched_pathspec,
+	size_t *matched_at);
+
+/* easy pathspec setup */
+
+extern int git_pathspec__init(git_pathspec *ps, const git_strarray *paths);
+
+extern void git_pathspec__clear(git_pathspec *ps);
+
+#endif

vendor/libgit2-sys/libgit2/src/pool.c

diff --git a/vendor/libgit2-sys/libgit2/src/pool.c b/vendor/libgit2-sys/libgit2/src/pool.c
new file mode 100644
index 0000000..c0efe9c
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/pool.c
@@ -0,0 +1,244 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "pool.h"
+
+#include "posix.h"
+#ifndef GIT_WIN32
+#include <unistd.h>
+#endif
+
+struct git_pool_page {
+	git_pool_page *next;
+	uint32_t size;
+	uint32_t avail;
+	GIT_ALIGN(char data[GIT_FLEX_ARRAY], 8);
+};
+
+static void *pool_alloc_page(git_pool *pool, uint32_t size);
+
+uint32_t git_pool__system_page_size(void)
+{
+	static uint32_t size = 0;
+
+	if (!size) {
+		size_t page_size;
+		if (git__page_size(&page_size) < 0)
+			page_size = 4096;
+		/* allow space for malloc overhead */
+		size = page_size - (2 * sizeof(void *)) - sizeof(git_pool_page);
+	}
+
+	return size;
+}
+
+#ifndef GIT_DEBUG_POOL
+void git_pool_init(git_pool *pool, uint32_t item_size)
+{
+	assert(pool);
+	assert(item_size >= 1);
+
+	memset(pool, 0, sizeof(git_pool));
+	pool->item_size = item_size;
+	pool->page_size = git_pool__system_page_size();
+}
+
+void git_pool_clear(git_pool *pool)
+{
+	git_pool_page *scan, *next;
+
+	for (scan = pool->pages; scan != NULL; scan = next) {
+		next = scan->next;
+		git__free(scan);
+	}
+
+	pool->pages = NULL;
+}
+
+static void *pool_alloc_page(git_pool *pool, uint32_t size)
+{
+	git_pool_page *page;
+	const uint32_t new_page_size = (size <= pool->page_size) ? pool->page_size : size;
+	size_t alloc_size;
+
+	if (GIT_ADD_SIZET_OVERFLOW(&alloc_size, new_page_size, sizeof(git_pool_page)) ||
+		!(page = git__malloc(alloc_size)))
+		return NULL;
+
+	page->size = new_page_size;
+	page->avail = new_page_size - size;
+	page->next = pool->pages;
+
+	pool->pages = page;
+
+	return page->data;
+}
+
+static void *pool_alloc(git_pool *pool, uint32_t size)
+{
+	git_pool_page *page = pool->pages;
+	void *ptr = NULL;
+
+	if (!page || page->avail < size)
+		return pool_alloc_page(pool, size);
+
+	ptr = &page->data[page->size - page->avail];
+	page->avail -= size;
+
+	return ptr;
+}
+
+uint32_t git_pool__open_pages(git_pool *pool)
+{
+	uint32_t ct = 0;
+	git_pool_page *scan;
+	for (scan = pool->pages; scan != NULL; scan = scan->next) ct++;
+	return ct;
+}
+
+bool git_pool__ptr_in_pool(git_pool *pool, void *ptr)
+{
+	git_pool_page *scan;
+	for (scan = pool->pages; scan != NULL; scan = scan->next)
+		if ((void *)scan->data <= ptr &&
+			(void *)(((char *)scan->data) + scan->size) > ptr)
+			return true;
+	return false;
+}
+
+#else
+
+static int git_pool__ptr_cmp(const void * a, const void * b)
+{
+	if(a > b) {
+		return 1;
+	}
+	if(a < b) {
+		return -1;
+	}
+	else {
+		return 0;
+	}
+}
+
+void git_pool_init(git_pool *pool, uint32_t item_size)
+{
+	assert(pool);
+	assert(item_size >= 1);
+
+	memset(pool, 0, sizeof(git_pool));
+	pool->item_size = item_size;
+	pool->page_size = git_pool__system_page_size();
+	git_vector_init(&pool->allocations, 100, git_pool__ptr_cmp);
+}
+
+void git_pool_clear(git_pool *pool)
+{
+	git_vector_free_deep(&pool->allocations);
+}
+
+static void *pool_alloc(git_pool *pool, uint32_t size) {
+	void *ptr = NULL;
+	if((ptr = git__malloc(size)) == NULL) {
+		return NULL;
+	}
+	git_vector_insert_sorted(&pool->allocations, ptr, NULL);
+	return ptr;
+}
+
+bool git_pool__ptr_in_pool(git_pool *pool, void *ptr)
+{
+	size_t pos;
+	return git_vector_bsearch(&pos, &pool->allocations, ptr) != GIT_ENOTFOUND;
+}
+#endif
+
+void git_pool_swap(git_pool *a, git_pool *b)
+{
+	git_pool temp;
+
+	if (a == b)
+		return;
+
+	memcpy(&temp, a, sizeof(temp));
+	memcpy(a, b, sizeof(temp));
+	memcpy(b, &temp, sizeof(temp));
+}
+
+static uint32_t alloc_size(git_pool *pool, uint32_t count)
+{
+	const uint32_t align = sizeof(void *) - 1;
+
+	if (pool->item_size > 1) {
+		const uint32_t item_size = (pool->item_size + align) & ~align;
+		return item_size * count;
+	}
+
+	return (count + align) & ~align;
+}
+
+void *git_pool_malloc(git_pool *pool, uint32_t items)
+{
+	return pool_alloc(pool, alloc_size(pool, items));
+}
+
+void *git_pool_mallocz(git_pool *pool, uint32_t items)
+{
+	const uint32_t size = alloc_size(pool, items);
+	void *ptr = pool_alloc(pool, size);
+	if (ptr)
+		memset(ptr, 0x0, size);
+	return ptr;
+}
+
+char *git_pool_strndup(git_pool *pool, const char *str, size_t n)
+{
+	char *ptr = NULL;
+
+	assert(pool && str && pool->item_size == sizeof(char));
+
+	if ((uint32_t)(n + 1) < n)
+		return NULL;
+
+	if ((ptr = git_pool_malloc(pool, (uint32_t)(n + 1))) != NULL) {
+		memcpy(ptr, str, n);
+		ptr[n] = '\0';
+	}
+
+	return ptr;
+}
+
+char *git_pool_strdup(git_pool *pool, const char *str)
+{
+	assert(pool && str && pool->item_size == sizeof(char));
+	return git_pool_strndup(pool, str, strlen(str));
+}
+
+char *git_pool_strdup_safe(git_pool *pool, const char *str)
+{
+	return str ? git_pool_strdup(pool, str) : NULL;
+}
+
+char *git_pool_strcat(git_pool *pool, const char *a, const char *b)
+{
+	void *ptr;
+	size_t len_a, len_b;
+
+	assert(pool && pool->item_size == sizeof(char));
+
+	len_a = a ? strlen(a) : 0;
+	len_b = b ? strlen(b) : 0;
+
+	if ((ptr = git_pool_malloc(pool, (uint32_t)(len_a + len_b + 1))) != NULL) {
+		if (len_a)
+			memcpy(ptr, a, len_a);
+		if (len_b)
+			memcpy(((char *)ptr) + len_a, b, len_b);
+		*(((char *)ptr) + len_a + len_b) = '\0';
+	}
+	return ptr;
+}

vendor/libgit2-sys/libgit2/src/pool.h

diff --git a/vendor/libgit2-sys/libgit2/src/pool.h b/vendor/libgit2-sys/libgit2/src/pool.h
new file mode 100644
index 0000000..92ddf99
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/pool.h
@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_pool_h__
+#define INCLUDE_pool_h__
+
+#include "common.h"
+
+#include "vector.h"
+
+typedef struct git_pool_page git_pool_page;
+
+#ifndef GIT_DEBUG_POOL
+/**
+ * Chunked allocator.
+ *
+ * A `git_pool` can be used when you want to cheaply allocate
+ * multiple items of the same type and are willing to free them
+ * all together with a single call.  The two most common cases
+ * are a set of fixed size items (such as lots of OIDs) or a
+ * bunch of strings.
+ *
+ * Internally, a `git_pool` allocates pages of memory and then
+ * deals out blocks from the trailing unused portion of each page.
+ * The pages guarantee that the number of actual allocations done
+ * will be much smaller than the number of items needed.
+ *
+ * For examples of how to set up a `git_pool` see `git_pool_init`.
+ */
+typedef struct {
+	git_pool_page *pages; /* allocated pages */
+	uint32_t item_size;  /* size of single alloc unit in bytes */
+	uint32_t page_size;  /* size of page in bytes */
+} git_pool;
+
+#define GIT_POOL_INIT { NULL, 0, 0 }
+
+#else
+
+/**
+ * Debug chunked allocator.
+ *
+ * Acts just like `git_pool` but instead of actually pooling allocations it
+ * passes them through to `git__malloc`. This makes it possible to easily debug
+ * systems that use `git_pool` using valgrind.
+ *
+ * In order to track allocations during the lifetime of the pool we use a
+ * `git_vector`. When the pool is deallocated everything in the vector is
+ * freed.
+ *
+ * `API is exactly the same as the standard `git_pool` with one exception.
+ * Since we aren't allocating pages to hand out in chunks we can't easily
+ * implement `git_pool__open_pages`.
+ */
+typedef struct {
+	git_vector allocations;
+	uint32_t item_size;
+	uint32_t page_size;
+} git_pool;
+
+#define GIT_POOL_INIT { GIT_VECTOR_INIT, 0, 0 }
+
+#endif
+
+/**
+ * Initialize a pool.
+ *
+ * To allocation strings, use like this:
+ *
+ *     git_pool_init(&string_pool, 1);
+ *     my_string = git_pool_strdup(&string_pool, your_string);
+ *
+ * To allocate items of fixed size, use like this:
+ *
+ *     git_pool_init(&pool, sizeof(item));
+ *     my_item = git_pool_malloc(&pool, 1);
+ *
+ * Of course, you can use this in other ways, but those are the
+ * two most common patterns.
+ */
+extern void git_pool_init(git_pool *pool, uint32_t item_size);
+
+/**
+ * Free all items in pool
+ */
+extern void git_pool_clear(git_pool *pool);
+
+/**
+ * Swap two pools with one another
+ */
+extern void git_pool_swap(git_pool *a, git_pool *b);
+
+/**
+ * Allocate space for one or more items from a pool.
+ */
+extern void *git_pool_malloc(git_pool *pool, uint32_t items);
+extern void *git_pool_mallocz(git_pool *pool, uint32_t items);
+
+/**
+ * Allocate space and duplicate string data into it.
+ *
+ * This is allowed only for pools with item_size == sizeof(char)
+ */
+extern char *git_pool_strndup(git_pool *pool, const char *str, size_t n);
+
+/**
+ * Allocate space and duplicate a string into it.
+ *
+ * This is allowed only for pools with item_size == sizeof(char)
+ */
+extern char *git_pool_strdup(git_pool *pool, const char *str);
+
+/**
+ * Allocate space and duplicate a string into it, NULL is no error.
+ *
+ * This is allowed only for pools with item_size == sizeof(char)
+ */
+extern char *git_pool_strdup_safe(git_pool *pool, const char *str);
+
+/**
+ * Allocate space for the concatenation of two strings.
+ *
+ * This is allowed only for pools with item_size == sizeof(char)
+ */
+extern char *git_pool_strcat(git_pool *pool, const char *a, const char *b);
+
+/*
+ * Misc utilities
+ */
+#ifndef GIT_DEBUG_POOL
+extern uint32_t git_pool__open_pages(git_pool *pool);
+#endif
+extern bool git_pool__ptr_in_pool(git_pool *pool, void *ptr);
+
+#endif

vendor/libgit2-sys/libgit2/src/posix.c

diff --git a/vendor/libgit2-sys/libgit2/src/posix.c b/vendor/libgit2-sys/libgit2/src/posix.c
new file mode 100644
index 0000000..6e7985e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/posix.c
@@ -0,0 +1,272 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "posix.h"
+
+#include "path.h"
+#include <stdio.h>
+#include <ctype.h>
+
+size_t p_fsync__cnt = 0;
+
+#ifndef GIT_WIN32
+
+#ifdef NO_ADDRINFO
+
+int p_getaddrinfo(
+	const char *host,
+	const char *port,
+	struct addrinfo *hints,
+	struct addrinfo **info)
+{
+	struct addrinfo *ainfo, *ai;
+	int p = 0;
+
+	GIT_UNUSED(hints);
+
+	if ((ainfo = malloc(sizeof(struct addrinfo))) == NULL)
+		return -1;
+
+	if ((ainfo->ai_hostent = gethostbyname(host)) == NULL) {
+		free(ainfo);
+		return -2;
+	}
+
+	ainfo->ai_servent = getservbyname(port, 0);
+
+	if (ainfo->ai_servent)
+		ainfo->ai_port = ainfo->ai_servent->s_port;
+	else
+		ainfo->ai_port = htons(atol(port));
+
+	memcpy(&ainfo->ai_addr_in.sin_addr,
+			ainfo->ai_hostent->h_addr_list[0],
+			ainfo->ai_hostent->h_length);
+
+	ainfo->ai_protocol = 0;
+	ainfo->ai_socktype = hints->ai_socktype;
+	ainfo->ai_family = ainfo->ai_hostent->h_addrtype;
+	ainfo->ai_addr_in.sin_family = ainfo->ai_family;
+	ainfo->ai_addr_in.sin_port = ainfo->ai_port;
+	ainfo->ai_addr = (struct addrinfo *)&ainfo->ai_addr_in;
+	ainfo->ai_addrlen = sizeof(struct sockaddr_in);
+
+	*info = ainfo;
+
+	if (ainfo->ai_hostent->h_addr_list[1] == NULL) {
+		ainfo->ai_next = NULL;
+		return 0;
+	}
+
+	ai = ainfo;
+
+	for (p = 1; ainfo->ai_hostent->h_addr_list[p] != NULL; p++) {
+		if (!(ai->ai_next = malloc(sizeof(struct addrinfo)))) {
+			p_freeaddrinfo(ainfo);
+			return -1;
+		}
+		memcpy(ai->ai_next, ainfo, sizeof(struct addrinfo));
+		memcpy(&ai->ai_next->ai_addr_in.sin_addr,
+			ainfo->ai_hostent->h_addr_list[p],
+			ainfo->ai_hostent->h_length);
+		ai->ai_next->ai_addr = (struct addrinfo *)&ai->ai_next->ai_addr_in;
+		ai = ai->ai_next;
+	}
+
+	ai->ai_next = NULL;
+	return 0;
+}
+
+void p_freeaddrinfo(struct addrinfo *info)
+{
+	struct addrinfo *p, *next;
+
+	p = info;
+
+	while(p != NULL) {
+		next = p->ai_next;
+		free(p);
+		p = next;
+	}
+}
+
+const char *p_gai_strerror(int ret)
+{
+	switch(ret) {
+	case -1: return "Out of memory"; break;
+	case -2: return "Address lookup failed"; break;
+	default: return "Unknown error"; break;
+	}
+}
+
+#endif /* NO_ADDRINFO */
+
+int p_open(const char *path, volatile int flags, ...)
+{
+	mode_t mode = 0;
+
+	if (flags & O_CREAT) {
+		va_list arg_list;
+
+		va_start(arg_list, flags);
+		mode = (mode_t)va_arg(arg_list, int);
+		va_end(arg_list);
+	}
+
+	return open(path, flags | O_BINARY | O_CLOEXEC, mode);
+}
+
+int p_creat(const char *path, mode_t mode)
+{
+	return open(path, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_CLOEXEC, mode);
+}
+
+int p_getcwd(char *buffer_out, size_t size)
+{
+	char *cwd_buffer;
+
+	assert(buffer_out && size > 0);
+
+	cwd_buffer = getcwd(buffer_out, size);
+
+	if (cwd_buffer == NULL)
+		return -1;
+
+	git_path_mkposix(buffer_out);
+	git_path_string_to_dir(buffer_out, size); /* append trailing slash */
+
+	return 0;
+}
+
+int p_rename(const char *from, const char *to)
+{
+	if (!link(from, to)) {
+		p_unlink(from);
+		return 0;
+	}
+
+	if (!rename(from, to))
+		return 0;
+
+	return -1;
+}
+
+#endif /* GIT_WIN32 */
+
+ssize_t p_read(git_file fd, void *buf, size_t cnt)
+{
+	char *b = buf;
+
+	if (!git__is_ssizet(cnt)) {
+#ifdef GIT_WIN32
+		SetLastError(ERROR_INVALID_PARAMETER);
+#endif
+		errno = EINVAL;
+		return -1;
+	}
+
+	while (cnt) {
+		ssize_t r;
+#ifdef GIT_WIN32
+		r = read(fd, b, cnt > INT_MAX ? INT_MAX : (unsigned int)cnt);
+#else
+		r = read(fd, b, cnt);
+#endif
+		if (r < 0) {
+			if (errno == EINTR || errno == EAGAIN)
+				continue;
+			return -1;
+		}
+		if (!r)
+			break;
+		cnt -= r;
+		b += r;
+	}
+	return (b - (char *)buf);
+}
+
+int p_write(git_file fd, const void *buf, size_t cnt)
+{
+	const char *b = buf;
+
+	while (cnt) {
+		ssize_t r;
+#ifdef GIT_WIN32
+		assert((size_t)((unsigned int)cnt) == cnt);
+		r = write(fd, b, (unsigned int)cnt);
+#else
+		r = write(fd, b, cnt);
+#endif
+		if (r < 0) {
+			if (errno == EINTR || GIT_ISBLOCKED(errno))
+				continue;
+			return -1;
+		}
+		if (!r) {
+			errno = EPIPE;
+			return -1;
+		}
+		cnt -= r;
+		b += r;
+	}
+	return 0;
+}
+
+#ifdef NO_MMAP
+
+#include "map.h"
+
+int git__page_size(size_t *page_size)
+{
+	/* dummy; here we don't need any alignment anyway */
+	*page_size = 4096;
+	return 0;
+}
+
+int git__mmap_alignment(size_t *alignment)
+{
+	/* dummy; here we don't need any alignment anyway */
+	*alignment = 4096;
+	return 0;
+}
+
+
+int p_mmap(git_map *out, size_t len, int prot, int flags, int fd, git_off_t offset)
+{
+	GIT_MMAP_VALIDATE(out, len, prot, flags);
+
+	out->data = NULL;
+	out->len = 0;
+
+	if ((prot & GIT_PROT_WRITE) && ((flags & GIT_MAP_TYPE) == GIT_MAP_SHARED)) {
+		giterr_set(GITERR_OS, "trying to map shared-writeable");
+		return -1;
+	}
+
+	out->data = malloc(len);
+	GITERR_CHECK_ALLOC(out->data);
+
+	if (!git__is_ssizet(len) ||
+		(p_lseek(fd, offset, SEEK_SET) < 0) ||
+		(p_read(fd, out->data, len) != (ssize_t)len)) {
+		giterr_set(GITERR_OS, "mmap emulation failed");
+		return -1;
+	}
+
+	out->len = len;
+	return 0;
+}
+
+int p_munmap(git_map *map)
+{
+	assert(map != NULL);
+	free(map->data);
+
+	return 0;
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/posix.h

diff --git a/vendor/libgit2-sys/libgit2/src/posix.h b/vendor/libgit2-sys/libgit2/src/posix.h
new file mode 100644
index 0000000..2934f24
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/posix.h
@@ -0,0 +1,175 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_posix_h__
+#define INCLUDE_posix_h__
+
+#include "common.h"
+
+#include <fcntl.h>
+#include <time.h>
+#include "fnmatch.h"
+
+/* stat: file mode type testing macros */
+#ifndef S_IFGITLINK
+#define S_IFGITLINK 0160000
+#define S_ISGITLINK(m) (((m) & S_IFMT) == S_IFGITLINK)
+#endif
+
+#ifndef S_IFLNK
+#define S_IFLNK 0120000
+#undef _S_IFLNK
+#define _S_IFLNK S_IFLNK
+#endif
+
+#ifndef S_IWUSR
+#define S_IWUSR 00200
+#endif
+
+#ifndef S_IXUSR
+#define S_IXUSR 00100
+#endif
+
+#ifndef S_ISLNK
+#define S_ISLNK(m) (((m) & _S_IFMT) == _S_IFLNK)
+#endif
+
+#ifndef S_ISDIR
+#define S_ISDIR(m) (((m) & _S_IFMT) == _S_IFDIR)
+#endif
+
+#ifndef S_ISREG
+#define S_ISREG(m) (((m) & _S_IFMT) == _S_IFREG)
+#endif
+
+#ifndef S_ISFIFO
+#define S_ISFIFO(m) (((m) & _S_IFMT) == _S_IFIFO)
+#endif
+
+/* if S_ISGID is not defined, then don't try to set it */
+#ifndef S_ISGID
+#define S_ISGID 0
+#endif
+
+#ifndef O_BINARY
+#define O_BINARY 0
+#endif
+#ifndef O_CLOEXEC
+#define O_CLOEXEC 0
+#endif
+#ifndef SOCK_CLOEXEC
+#define SOCK_CLOEXEC 0
+#endif
+
+/* access() mode parameter #defines	*/
+#ifndef F_OK
+#define F_OK 0 /* existence check */
+#endif
+#ifndef W_OK
+#define W_OK 2 /* write mode check */
+#endif
+#ifndef R_OK
+#define R_OK 4 /* read mode check */
+#endif
+
+/* Determine whether an errno value indicates that a read or write failed
+ * because the descriptor is blocked.
+ */
+#if defined(EWOULDBLOCK)
+#define GIT_ISBLOCKED(e) ((e) == EAGAIN || (e) == EWOULDBLOCK)
+#else
+#define GIT_ISBLOCKED(e) ((e) == EAGAIN)
+#endif
+
+/* define some standard errnos that the runtime may be missing.  for example,
+ * mingw lacks EAFNOSUPPORT. */
+#ifndef EAFNOSUPPORT
+#define EAFNOSUPPORT (INT_MAX-1)
+#endif
+
+typedef int git_file;
+
+/**
+ * Standard POSIX Methods
+ *
+ * All the methods starting with the `p_` prefix are
+ * direct ports of the standard POSIX methods.
+ *
+ * Some of the methods are slightly wrapped to provide
+ * saner defaults. Some of these methods are emulated
+ * in Windows platforms.
+ *
+ * Use your manpages to check the docs on these.
+ */
+
+extern ssize_t p_read(git_file fd, void *buf, size_t cnt);
+extern int p_write(git_file fd, const void *buf, size_t cnt);
+
+#define p_close(fd) close(fd)
+#define p_umask(m) umask(m)
+
+extern int p_open(const char *path, int flags, ...);
+extern int p_creat(const char *path, mode_t mode);
+extern int p_getcwd(char *buffer_out, size_t size);
+extern int p_rename(const char *from, const char *to);
+
+extern int git__page_size(size_t *page_size);
+extern int git__mmap_alignment(size_t *page_size);
+
+/* The number of times `p_fsync` has been called.  Note that this is for
+ * test code only; it it not necessarily thread-safe and should not be
+ * relied upon in production.
+ */
+extern size_t p_fsync__cnt;
+
+/**
+ * Platform-dependent methods
+ */
+#ifdef GIT_WIN32
+#	include "win32/posix.h"
+#else
+#	include "unix/posix.h"
+#endif
+
+#include "strnlen.h"
+
+#ifdef NO_READDIR_R
+GIT_INLINE(int) p_readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result)
+{
+	GIT_UNUSED(entry);
+	*result = readdir(dirp);
+	return 0;
+}
+#else /* NO_READDIR_R */
+#	define p_readdir_r(d,e,r) readdir_r(d,e,r)
+#endif
+
+#ifdef NO_ADDRINFO
+#	include <netdb.h>
+struct addrinfo {
+	struct hostent *ai_hostent;
+	struct servent *ai_servent;
+	struct sockaddr_in ai_addr_in;
+	struct sockaddr *ai_addr;
+	size_t ai_addrlen;
+	int ai_family;
+	int ai_socktype;
+	int ai_protocol;
+	long ai_port;
+	struct addrinfo *ai_next;
+};
+
+extern int p_getaddrinfo(const char *host, const char *port,
+	struct addrinfo *hints, struct addrinfo **info);
+extern void p_freeaddrinfo(struct addrinfo *info);
+extern const char *p_gai_strerror(int ret);
+#else
+#	define p_getaddrinfo(a, b, c, d) getaddrinfo(a, b, c, d)
+#	define p_freeaddrinfo(a) freeaddrinfo(a)
+#	define p_gai_strerror(c) gai_strerror(c)
+#endif /* NO_ADDRINFO */
+
+#endif

vendor/libgit2-sys/libgit2/src/pqueue.c

diff --git a/vendor/libgit2-sys/libgit2/src/pqueue.c b/vendor/libgit2-sys/libgit2/src/pqueue.c
new file mode 100644
index 0000000..3820e99
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/pqueue.c
@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "pqueue.h"
+
+#include "util.h"
+
+#define PQUEUE_LCHILD_OF(I) (((I)<<1)+1)
+#define PQUEUE_RCHILD_OF(I) (((I)<<1)+2)
+#define PQUEUE_PARENT_OF(I) (((I)-1)>>1)
+
+int git_pqueue_init(
+	git_pqueue *pq,
+	uint32_t flags,
+	size_t init_size,
+	git_vector_cmp cmp)
+{
+	int error = git_vector_init(pq, init_size, cmp);
+
+	if (!error) {
+		/* mix in our flags */
+		pq->flags |= flags;
+
+		/* if fixed size heap, pretend vector is exactly init_size elements */
+		if ((flags & GIT_PQUEUE_FIXED_SIZE) && init_size > 0)
+			pq->_alloc_size = init_size;
+	}
+
+	return error;
+}
+
+static void pqueue_up(git_pqueue *pq, size_t el)
+{
+	size_t parent_el = PQUEUE_PARENT_OF(el);
+	void *kid = git_vector_get(pq, el);
+
+	while (el > 0) {
+		void *parent = pq->contents[parent_el];
+
+		if (pq->_cmp(parent, kid) <= 0)
+			break;
+
+		pq->contents[el] = parent;
+
+		el = parent_el;
+		parent_el = PQUEUE_PARENT_OF(el);
+	}
+
+	pq->contents[el] = kid;
+}
+
+static void pqueue_down(git_pqueue *pq, size_t el)
+{
+	void *parent = git_vector_get(pq, el), *kid, *rkid;
+
+	while (1) {
+		size_t kid_el = PQUEUE_LCHILD_OF(el);
+
+		if ((kid = git_vector_get(pq, kid_el)) == NULL)
+			break;
+
+		if ((rkid = git_vector_get(pq, kid_el + 1)) != NULL &&
+			pq->_cmp(kid, rkid) > 0) {
+			kid    = rkid;
+			kid_el += 1;
+		}
+
+		if (pq->_cmp(parent, kid) <= 0)
+			break;
+
+		pq->contents[el] = kid;
+		el = kid_el;
+	}
+
+	pq->contents[el] = parent;
+}
+
+int git_pqueue_insert(git_pqueue *pq, void *item)
+{
+	int error = 0;
+
+	/* if heap is full, pop the top element if new one should replace it */
+	if ((pq->flags & GIT_PQUEUE_FIXED_SIZE) != 0 &&
+		pq->length >= pq->_alloc_size)
+	{
+		/* skip this item if below min item in heap or if
+		 * we do not have a comparison function */
+		if (!pq->_cmp || pq->_cmp(item, git_vector_get(pq, 0)) <= 0)
+			return 0;
+		/* otherwise remove the min item before inserting new */
+		(void)git_pqueue_pop(pq);
+	}
+
+	if (!(error = git_vector_insert(pq, item)) && pq->_cmp)
+		pqueue_up(pq, pq->length - 1);
+
+	return error;
+}
+
+void *git_pqueue_pop(git_pqueue *pq)
+{
+	void *rval;
+
+	if (!pq->_cmp) {
+		rval = git_vector_last(pq);
+	} else {
+		rval = git_pqueue_get(pq, 0);
+	}
+
+	if (git_pqueue_size(pq) > 1 && pq->_cmp) {
+		/* move last item to top of heap, shrink, and push item down */
+		pq->contents[0] = git_vector_last(pq);
+		git_vector_pop(pq);
+		pqueue_down(pq, 0);
+	} else {
+		/* all we need to do is shrink the heap in this case */
+		git_vector_pop(pq);
+	}
+
+	return rval;
+}

vendor/libgit2-sys/libgit2/src/pqueue.h

diff --git a/vendor/libgit2-sys/libgit2/src/pqueue.h b/vendor/libgit2-sys/libgit2/src/pqueue.h
new file mode 100644
index 0000000..c0a6cd4
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/pqueue.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) the libgit2 contributors.  All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_pqueue_h__
+#define INCLUDE_pqueue_h__
+
+#include "common.h"
+
+#include "vector.h"
+
+typedef git_vector git_pqueue;
+
+enum {
+	/* flag meaning: don't grow heap, keep highest values only */
+	GIT_PQUEUE_FIXED_SIZE = (GIT_VECTOR_FLAG_MAX << 1),
+};
+
+/**
+ * Initialize priority queue
+ *
+ * @param pq The priority queue struct to initialize
+ * @param flags Flags (see above) to control queue behavior
+ * @param init_size The initial queue size
+ * @param cmp The entry priority comparison function
+ * @return 0 on success, <0 on error
+ */
+extern int git_pqueue_init(
+	git_pqueue *pq,
+	uint32_t flags,
+	size_t init_size,
+	git_vector_cmp cmp);
+
+#define git_pqueue_free  git_vector_free
+#define git_pqueue_clear git_vector_clear
+#define git_pqueue_size  git_vector_length
+#define git_pqueue_get   git_vector_get
+#define git_pqueue_reverse git_vector_reverse
+
+/**
+ * Insert a new item into the queue
+ *
+ * @param pq The priority queue
+ * @param item Pointer to the item data
+ * @return 0 on success, <0 on failure
+ */
+extern int git_pqueue_insert(git_pqueue *pq, void *item);
+
+/**
+ * Remove the top item in the priority queue
+ *
+ * @param pq The priority queue
+ * @return item from heap on success, NULL if queue is empty
+ */
+extern void *git_pqueue_pop(git_pqueue *pq);
+
+#endif

vendor/libgit2-sys/libgit2/src/proxy.c

diff --git a/vendor/libgit2-sys/libgit2/src/proxy.c b/vendor/libgit2-sys/libgit2/src/proxy.c
new file mode 100644
index 0000000..9bc2c7f
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/proxy.c
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "proxy.h"
+
+#include "git2/proxy.h"
+
+int git_proxy_init_options(git_proxy_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_proxy_options, GIT_PROXY_OPTIONS_INIT);
+	return 0;
+}
+
+int git_proxy_options_dup(git_proxy_options *tgt, const git_proxy_options *src)
+{
+	if (!src) {
+		git_proxy_init_options(tgt, GIT_PROXY_OPTIONS_VERSION);
+		return 0;
+	}
+
+	memcpy(tgt, src, sizeof(git_proxy_options));
+	if (src->url) {
+		tgt->url = git__strdup(src->url);
+		GITERR_CHECK_ALLOC(tgt->url);
+	}
+
+	return 0;
+}
+
+void git_proxy_options_clear(git_proxy_options *opts)
+{
+	git__free((char *) opts->url);
+	opts->url = NULL;
+}

vendor/libgit2-sys/libgit2/src/proxy.h

diff --git a/vendor/libgit2-sys/libgit2/src/proxy.h b/vendor/libgit2-sys/libgit2/src/proxy.h
new file mode 100644
index 0000000..f8b5c4b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/proxy.h
@@ -0,0 +1,17 @@
+/*
+* Copyright (C) the libgit2 contributors. All rights reserved.
+*
+* This file is part of libgit2, distributed under the GNU GPL v2 with
+* a Linking Exception. For full terms see the included COPYING file.
+*/
+#ifndef INCLUDE_proxy_h__
+#define INCLUDE_proxy_h__
+
+#include "common.h"
+
+#include "git2/proxy.h"
+
+extern int git_proxy_options_dup(git_proxy_options *tgt, const git_proxy_options *src);
+extern void git_proxy_options_clear(git_proxy_options *opts);
+
+#endif

vendor/libgit2-sys/libgit2/src/push.c

diff --git a/vendor/libgit2-sys/libgit2/src/push.c b/vendor/libgit2-sys/libgit2/src/push.c
new file mode 100644
index 0000000..85b683e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/push.c
@@ -0,0 +1,554 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "push.h"
+
+#include "git2.h"
+
+#include "pack.h"
+#include "pack-objects.h"
+#include "remote.h"
+#include "vector.h"
+#include "tree.h"
+
+static int push_spec_rref_cmp(const void *a, const void *b)
+{
+	const push_spec *push_spec_a = a, *push_spec_b = b;
+
+	return strcmp(push_spec_a->refspec.dst, push_spec_b->refspec.dst);
+}
+
+static int push_status_ref_cmp(const void *a, const void *b)
+{
+	const push_status *push_status_a = a, *push_status_b = b;
+
+	return strcmp(push_status_a->ref, push_status_b->ref);
+}
+
+int git_push_new(git_push **out, git_remote *remote)
+{
+	git_push *p;
+
+	*out = NULL;
+
+	p = git__calloc(1, sizeof(*p));
+	GITERR_CHECK_ALLOC(p);
+
+	p->repo = remote->repo;
+	p->remote = remote;
+	p->report_status = 1;
+	p->pb_parallelism = 1;
+
+	if (git_vector_init(&p->specs, 0, push_spec_rref_cmp) < 0) {
+		git__free(p);
+		return -1;
+	}
+
+	if (git_vector_init(&p->status, 0, push_status_ref_cmp) < 0) {
+		git_vector_free(&p->specs);
+		git__free(p);
+		return -1;
+	}
+
+	if (git_vector_init(&p->updates, 0, NULL) < 0) {
+		git_vector_free(&p->status);
+		git_vector_free(&p->specs);
+		git__free(p);
+		return -1;
+	}
+
+	*out = p;
+	return 0;
+}
+
+int git_push_set_options(git_push *push, const git_push_options *opts)
+{
+	if (!push || !opts)
+		return -1;
+
+	GITERR_CHECK_VERSION(opts, GIT_PUSH_OPTIONS_VERSION, "git_push_options");
+
+	push->pb_parallelism = opts->pb_parallelism;
+	push->custom_headers = &opts->custom_headers;
+
+	return 0;
+}
+
+static void free_refspec(push_spec *spec)
+{
+	if (spec == NULL)
+		return;
+
+	git_refspec__free(&spec->refspec);
+	git__free(spec);
+}
+
+static int check_rref(char *ref)
+{
+	if (git__prefixcmp(ref, "refs/")) {
+		giterr_set(GITERR_INVALID, "not a valid reference '%s'", ref);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int check_lref(git_push *push, char *ref)
+{
+	/* lref must be resolvable to an existing object */
+	git_object *obj;
+	int error = git_revparse_single(&obj, push->repo, ref);
+	git_object_free(obj);
+
+	if (!error)
+		return 0;
+
+	if (error == GIT_ENOTFOUND)
+		giterr_set(GITERR_REFERENCE,
+			"src refspec '%s' does not match any existing object", ref);
+	else
+		giterr_set(GITERR_INVALID, "not a valid reference '%s'", ref);
+	return -1;
+}
+
+static int parse_refspec(git_push *push, push_spec **spec, const char *str)
+{
+	push_spec *s;
+
+	*spec = NULL;
+
+	s = git__calloc(1, sizeof(*s));
+	GITERR_CHECK_ALLOC(s);
+
+	if (git_refspec__parse(&s->refspec, str, false) < 0) {
+		giterr_set(GITERR_INVALID, "invalid refspec %s", str);
+		goto on_error;
+	}
+
+	if (s->refspec.src && s->refspec.src[0] != '\0' &&
+	    check_lref(push, s->refspec.src) < 0) {
+		goto on_error;
+	}
+
+	if (check_rref(s->refspec.dst) < 0)
+		goto on_error;
+
+	*spec = s;
+	return 0;
+
+on_error:
+	free_refspec(s);
+	return -1;
+}
+
+int git_push_add_refspec(git_push *push, const char *refspec)
+{
+	push_spec *spec;
+
+	if (parse_refspec(push, &spec, refspec) < 0 ||
+	    git_vector_insert(&push->specs, spec) < 0)
+		return -1;
+
+	return 0;
+}
+
+int git_push_update_tips(git_push *push, const git_remote_callbacks *callbacks)
+{
+	git_buf remote_ref_name = GIT_BUF_INIT;
+	size_t i, j;
+	git_refspec *fetch_spec;
+	push_spec *push_spec = NULL;
+	git_reference *remote_ref;
+	push_status *status;
+	int error = 0;
+
+	git_vector_foreach(&push->status, i, status) {
+		int fire_callback = 1;
+
+		/* Skip unsuccessful updates which have non-empty messages */
+		if (status->msg)
+			continue;
+
+		/* Find the corresponding remote ref */
+		fetch_spec = git_remote__matching_refspec(push->remote, status->ref);
+		if (!fetch_spec)
+			continue;
+
+		/* Clear the buffer which can be dirty from previous iteration */
+		git_buf_clear(&remote_ref_name);
+
+		if ((error = git_refspec_transform(&remote_ref_name, fetch_spec, status->ref)) < 0)
+			goto on_error;
+
+		/* Find matching  push ref spec */
+		git_vector_foreach(&push->specs, j, push_spec) {
+			if (!strcmp(push_spec->refspec.dst, status->ref))
+				break;
+		}
+
+		/* Could not find the corresponding push ref spec for this push update */
+		if (j == push->specs.length)
+			continue;
+
+		/* Update the remote ref */
+		if (git_oid_iszero(&push_spec->loid)) {
+			error = git_reference_lookup(&remote_ref, push->remote->repo, git_buf_cstr(&remote_ref_name));
+
+			if (error >= 0) {
+				error = git_reference_delete(remote_ref);
+				git_reference_free(remote_ref);
+			}
+		} else {
+			error = git_reference_create(NULL, push->remote->repo,
+						git_buf_cstr(&remote_ref_name), &push_spec->loid, 1,
+						"update by push");
+		}
+
+		if (error < 0) {
+			if (error != GIT_ENOTFOUND)
+				goto on_error;
+
+			giterr_clear();
+			fire_callback = 0;
+		}
+
+		if (fire_callback && callbacks && callbacks->update_tips) {
+			error = callbacks->update_tips(git_buf_cstr(&remote_ref_name),
+						&push_spec->roid, &push_spec->loid, callbacks->payload);
+
+			if (error < 0)
+				goto on_error;
+		}
+	}
+
+	error = 0;
+
+on_error:
+	git_buf_free(&remote_ref_name);
+	return error;
+}
+
+/**
+ * Insert all tags until we find a non-tag object, which is returned
+ * in `out`.
+ */
+static int enqueue_tag(git_object **out, git_push *push, git_oid *id)
+{
+	git_object *obj = NULL, *target = NULL;
+	int error;
+
+	if ((error = git_object_lookup(&obj, push->repo, id, GIT_OBJ_TAG)) < 0)
+		return error;
+
+	while (git_object_type(obj) == GIT_OBJ_TAG) {
+		if ((error = git_packbuilder_insert(push->pb, git_object_id(obj), NULL)) < 0)
+			break;
+
+		if ((error = git_tag_target(&target, (git_tag *) obj)) < 0)
+			break;
+
+		git_object_free(obj);
+		obj = target;
+	}
+
+	if (error < 0)
+		git_object_free(obj);
+	else
+		*out = obj;
+
+	return error;
+}
+
+static int queue_objects(git_push *push)
+{
+	git_remote_head *head;
+	push_spec *spec;
+	git_revwalk *rw;
+	unsigned int i;
+	int error = -1;
+
+	if (git_revwalk_new(&rw, push->repo) < 0)
+		return -1;
+
+	git_revwalk_sorting(rw, GIT_SORT_TIME);
+
+	git_vector_foreach(&push->specs, i, spec) {
+		git_otype type;
+		size_t size;
+
+		if (git_oid_iszero(&spec->loid))
+			/*
+			 * Delete reference on remote side;
+			 * nothing to do here.
+			 */
+			continue;
+
+		if (git_oid_equal(&spec->loid, &spec->roid))
+			continue; /* up-to-date */
+
+		if (git_odb_read_header(&size, &type, push->repo->_odb, &spec->loid) < 0)
+			goto on_error;
+
+		if (type == GIT_OBJ_TAG) {
+			git_object *target;
+
+			if ((error = enqueue_tag(&target, push, &spec->loid)) < 0)
+				goto on_error;
+
+			if (git_object_type(target) == GIT_OBJ_COMMIT) {
+				if (git_revwalk_push(rw, git_object_id(target)) < 0) {
+					git_object_free(target);
+					goto on_error;
+				}
+			} else {
+				if (git_packbuilder_insert(
+					push->pb, git_object_id(target), NULL) < 0) {
+					git_object_free(target);
+					goto on_error;
+				}
+			}
+			git_object_free(target);
+		} else if (git_revwalk_push(rw, &spec->loid) < 0)
+			goto on_error;
+
+		if (!spec->refspec.force) {
+			git_oid base;
+
+			if (git_oid_iszero(&spec->roid))
+				continue;
+
+			if (!git_odb_exists(push->repo->_odb, &spec->roid)) {
+				giterr_set(GITERR_REFERENCE, 
+					"cannot push because a reference that you are trying to update on the remote contains commits that are not present locally.");
+				error = GIT_ENONFASTFORWARD;
+				goto on_error;
+			}
+
+			error = git_merge_base(&base, push->repo,
+					       &spec->loid, &spec->roid);
+
+			if (error == GIT_ENOTFOUND ||
+				(!error && !git_oid_equal(&base, &spec->roid))) {
+				giterr_set(GITERR_REFERENCE,
+					"cannot push non-fastforwardable reference");
+				error = GIT_ENONFASTFORWARD;
+				goto on_error;
+			}
+
+			if (error < 0)
+				goto on_error;
+		}
+	}
+
+	git_vector_foreach(&push->remote->refs, i, head) {
+		if (git_oid_iszero(&head->oid))
+			continue;
+
+		/* TODO */
+		git_revwalk_hide(rw, &head->oid);
+	}
+
+	error = git_packbuilder_insert_walk(push->pb, rw);
+
+on_error:
+	git_revwalk_free(rw);
+	return error;
+}
+
+static int add_update(git_push *push, push_spec *spec)
+{
+	git_push_update *u = git__calloc(1, sizeof(git_push_update));
+	GITERR_CHECK_ALLOC(u);
+
+	u->src_refname = git__strdup(spec->refspec.src);
+	GITERR_CHECK_ALLOC(u->src_refname);
+
+	u->dst_refname = git__strdup(spec->refspec.dst);
+	GITERR_CHECK_ALLOC(u->dst_refname);
+
+	git_oid_cpy(&u->src, &spec->roid);
+	git_oid_cpy(&u->dst, &spec->loid);
+
+	return git_vector_insert(&push->updates, u);
+}
+
+static int calculate_work(git_push *push)
+{
+	git_remote_head *head;
+	push_spec *spec;
+	unsigned int i, j;
+
+	/* Update local and remote oids*/
+
+	git_vector_foreach(&push->specs, i, spec) {
+		if (spec->refspec.src && spec->refspec.src[0]!= '\0') {
+			/* This is a create or update.  Local ref must exist. */
+			if (git_reference_name_to_id(
+					&spec->loid, push->repo, spec->refspec.src) < 0) {
+				giterr_set(GITERR_REFERENCE, "no such reference '%s'", spec->refspec.src);
+				return -1;
+			}
+		}
+
+		/* Remote ref may or may not (e.g. during create) already exist. */
+		git_vector_foreach(&push->remote->refs, j, head) {
+			if (!strcmp(spec->refspec.dst, head->name)) {
+				git_oid_cpy(&spec->roid, &head->oid);
+				break;
+			}
+		}
+
+		if (add_update(push, spec) < 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+static int do_push(git_push *push, const git_remote_callbacks *callbacks)
+{
+	int error = 0;
+	git_transport *transport = push->remote->transport;
+
+	if (!transport->push) {
+		giterr_set(GITERR_NET, "remote transport doesn't support push");
+		error = -1;
+		goto on_error;
+	}
+
+	/*
+	 * A pack-file MUST be sent if either create or update command
+	 * is used, even if the server already has all the necessary
+	 * objects.  In this case the client MUST send an empty pack-file.
+	 */
+
+	if ((error = git_packbuilder_new(&push->pb, push->repo)) < 0)
+		goto on_error;
+
+	git_packbuilder_set_threads(push->pb, push->pb_parallelism);
+
+	if (callbacks && callbacks->pack_progress)
+		if ((error = git_packbuilder_set_callbacks(push->pb, callbacks->pack_progress, callbacks->payload)) < 0)
+			goto on_error;
+
+	if ((error = calculate_work(push)) < 0)
+		goto on_error;
+
+	if (callbacks && callbacks->push_negotiation &&
+	    (error = callbacks->push_negotiation((const git_push_update **) push->updates.contents,
+					  push->updates.length, callbacks->payload)) < 0)
+	    goto on_error;
+
+	if ((error = queue_objects(push)) < 0 ||
+	    (error = transport->push(transport, push, callbacks)) < 0)
+		goto on_error;
+
+on_error:
+	git_packbuilder_free(push->pb);
+	return error;
+}
+
+static int filter_refs(git_remote *remote)
+{
+	const git_remote_head **heads;
+	size_t heads_len, i;
+
+	git_vector_clear(&remote->refs);
+
+	if (git_remote_ls(&heads, &heads_len, remote) < 0)
+		return -1;
+
+	for (i = 0; i < heads_len; i++) {
+		if (git_vector_insert(&remote->refs, (void *)heads[i]) < 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+int git_push_finish(git_push *push, const git_remote_callbacks *callbacks)
+{
+	int error;
+
+	if (!git_remote_connected(push->remote) &&
+	    (error = git_remote_connect(push->remote, GIT_DIRECTION_PUSH, callbacks, NULL, push->custom_headers)) < 0)
+		return error;
+
+	if ((error = filter_refs(push->remote)) < 0 ||
+	    (error = do_push(push, callbacks)) < 0)
+		return error;
+
+	if (!push->unpack_ok) {
+		error = -1;
+		giterr_set(GITERR_NET, "unpacking the sent packfile failed on the remote");
+	}
+
+	return error;
+}
+
+int git_push_status_foreach(git_push *push,
+		int (*cb)(const char *ref, const char *msg, void *data),
+		void *data)
+{
+	push_status *status;
+	unsigned int i;
+
+	git_vector_foreach(&push->status, i, status) {
+		int error = cb(status->ref, status->msg, data);
+		if (error)
+			return giterr_set_after_callback(error);
+	}
+
+	return 0;
+}
+
+void git_push_status_free(push_status *status)
+{
+	if (status == NULL)
+		return;
+
+	git__free(status->msg);
+	git__free(status->ref);
+	git__free(status);
+}
+
+void git_push_free(git_push *push)
+{
+	push_spec *spec;
+	push_status *status;
+	git_push_update *update;
+	unsigned int i;
+
+	if (push == NULL)
+		return;
+
+	git_vector_foreach(&push->specs, i, spec) {
+		free_refspec(spec);
+	}
+	git_vector_free(&push->specs);
+
+	git_vector_foreach(&push->status, i, status) {
+		git_push_status_free(status);
+	}
+	git_vector_free(&push->status);
+
+	git_vector_foreach(&push->updates, i, update) {
+		git__free(update->src_refname);
+		git__free(update->dst_refname);
+		git__free(update);
+	}
+	git_vector_free(&push->updates);
+
+	git__free(push);
+}
+
+int git_push_init_options(git_push_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_push_options, GIT_PUSH_OPTIONS_INIT);
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/push.h

diff --git a/vendor/libgit2-sys/libgit2/src/push.h b/vendor/libgit2-sys/libgit2/src/push.h
new file mode 100644
index 0000000..31ac436
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/push.h
@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_push_h__
+#define INCLUDE_push_h__
+
+#include "common.h"
+
+#include "git2.h"
+#include "refspec.h"
+
+typedef struct push_spec {
+	struct git_refspec refspec;
+
+	git_oid loid;
+	git_oid roid;
+} push_spec;
+
+typedef struct push_status {
+	bool ok;
+
+	char *ref;
+	char *msg;
+} push_status;
+
+struct git_push {
+	git_repository *repo;
+	git_packbuilder *pb;
+	git_remote *remote;
+	git_vector specs;
+	git_vector updates;
+	bool report_status;
+
+	/* report-status */
+	bool unpack_ok;
+	git_vector status;
+
+	/* options */
+	unsigned pb_parallelism;
+	const git_strarray *custom_headers;
+};
+
+/**
+ * Free the given push status object
+ *
+ * @param status The push status object
+ */
+void git_push_status_free(push_status *status);
+
+/**
+ * Create a new push object
+ *
+ * @param out New push object
+ * @param remote Remote instance
+ *
+ * @return 0 or an error code
+ */
+int git_push_new(git_push **out, git_remote *remote);
+
+/**
+ * Set options on a push object
+ *
+ * @param push The push object
+ * @param opts The options to set on the push object
+ *
+ * @return 0 or an error code
+ */
+int git_push_set_options(
+	git_push *push,
+	const git_push_options *opts);
+
+/**
+ * Add a refspec to be pushed
+ *
+ * @param push The push object
+ * @param refspec Refspec string
+ *
+ * @return 0 or an error code
+ */
+int git_push_add_refspec(git_push *push, const char *refspec);
+
+/**
+ * Update remote tips after a push
+ *
+ * @param push The push object
+ * @param callbacks the callbacks to use for this connection
+ *
+ * @return 0 or an error code
+ */
+int git_push_update_tips(git_push *push, const git_remote_callbacks *callbacks);
+
+/**
+ * Perform the push
+ *
+ * This function will return an error in case of a protocol error or
+ * the server being unable to unpack the data we sent.
+ *
+ * The return value does not reflect whether the server accepted or
+ * refused any reference updates. Use `git_push_status_foreach()` in
+ * order to find out which updates were accepted or rejected.
+ *
+ * @param push The push object
+ * @param callbacks the callbacks to use for this connection
+ *
+ * @return 0 or an error code
+ */
+int git_push_finish(git_push *push, const git_remote_callbacks *callbacks);
+
+/**
+ * Invoke callback `cb' on each status entry
+ *
+ * For each of the updated references, we receive a status report in the
+ * form of `ok refs/heads/master` or `ng refs/heads/master <msg>`.
+ * `msg != NULL` means the reference has not been updated for the given
+ * reason.
+ *
+ * Return a non-zero value from the callback to stop the loop.
+ *
+ * @param push The push object
+ * @param cb The callback to call on each object
+ * @param data The payload passed to the callback
+ *
+ * @return 0 on success, non-zero callback return value, or error code
+ */
+int git_push_status_foreach(git_push *push,
+			int (*cb)(const char *ref, const char *msg, void *data),
+			void *data);
+
+/**
+ * Free the given push object
+ *
+ * @param push The push object
+ */
+void git_push_free(git_push *push);
+
+#endif

vendor/libgit2-sys/libgit2/src/rebase.c

diff --git a/vendor/libgit2-sys/libgit2/src/rebase.c b/vendor/libgit2-sys/libgit2/src/rebase.c
new file mode 100644
index 0000000..f1cb22f
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/rebase.c
@@ -0,0 +1,1364 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "buffer.h"
+#include "repository.h"
+#include "posix.h"
+#include "filebuf.h"
+#include "merge.h"
+#include "array.h"
+#include "config.h"
+#include "annotated_commit.h"
+#include "index.h"
+
+#include <git2/types.h>
+#include <git2/annotated_commit.h>
+#include <git2/rebase.h>
+#include <git2/commit.h>
+#include <git2/reset.h>
+#include <git2/revwalk.h>
+#include <git2/notes.h>
+
+#define REBASE_APPLY_DIR    "rebase-apply"
+#define REBASE_MERGE_DIR    "rebase-merge"
+
+#define HEAD_NAME_FILE      "head-name"
+#define ORIG_HEAD_FILE      "orig-head"
+#define HEAD_FILE           "head"
+#define ONTO_FILE           "onto"
+#define ONTO_NAME_FILE      "onto_name"
+#define QUIET_FILE          "quiet"
+
+#define MSGNUM_FILE         "msgnum"
+#define END_FILE            "end"
+#define CMT_FILE_FMT        "cmt.%" PRIuZ
+#define CURRENT_FILE        "current"
+#define REWRITTEN_FILE      "rewritten"
+
+#define ORIG_DETACHED_HEAD  "detached HEAD"
+
+#define NOTES_DEFAULT_REF   NULL
+
+#define REBASE_DIR_MODE     0777
+#define REBASE_FILE_MODE    0666
+
+typedef enum {
+	GIT_REBASE_TYPE_NONE = 0,
+	GIT_REBASE_TYPE_APPLY = 1,
+	GIT_REBASE_TYPE_MERGE = 2,
+	GIT_REBASE_TYPE_INTERACTIVE = 3,
+} git_rebase_type_t;
+
+struct git_rebase {
+	git_repository *repo;
+
+	git_rebase_options options;
+
+	git_rebase_type_t type;
+	char *state_path;
+
+	int head_detached : 1,
+		inmemory : 1,
+		quiet : 1,
+		started : 1;
+
+	git_array_t(git_rebase_operation) operations;
+	size_t current;
+
+	/* Used by in-memory rebase */
+	git_index *index;
+	git_commit *last_commit;
+
+	/* Used by regular (not in-memory) merge-style rebase */
+	git_oid orig_head_id;
+	char *orig_head_name;
+
+	git_oid onto_id;
+	char *onto_name;
+};
+
+#define GIT_REBASE_STATE_INIT {0}
+
+static int rebase_state_type(
+	git_rebase_type_t *type_out,
+	char **path_out,
+	git_repository *repo)
+{
+	git_buf path = GIT_BUF_INIT;
+	git_rebase_type_t type = GIT_REBASE_TYPE_NONE;
+
+	if (git_buf_joinpath(&path, repo->gitdir, REBASE_APPLY_DIR) < 0)
+		return -1;
+
+	if (git_path_isdir(git_buf_cstr(&path))) {
+		type = GIT_REBASE_TYPE_APPLY;
+		goto done;
+	}
+
+	git_buf_clear(&path);
+	if (git_buf_joinpath(&path, repo->gitdir, REBASE_MERGE_DIR) < 0)
+		return -1;
+
+	if (git_path_isdir(git_buf_cstr(&path))) {
+		type = GIT_REBASE_TYPE_MERGE;
+		goto done;
+	}
+
+done:
+	*type_out = type;
+
+	if (type != GIT_REBASE_TYPE_NONE && path_out)
+		*path_out = git_buf_detach(&path);
+
+	git_buf_free(&path);
+
+	return 0;
+}
+
+GIT_INLINE(int) rebase_readfile(
+	git_buf *out,
+	git_buf *state_path,
+	const char *filename)
+{
+	size_t state_path_len = state_path->size;
+	int error;
+
+	git_buf_clear(out);
+
+	if ((error = git_buf_joinpath(state_path, state_path->ptr, filename)) < 0 ||
+		(error = git_futils_readbuffer(out, state_path->ptr)) < 0)
+		goto done;
+
+	git_buf_rtrim(out);
+
+done:
+	git_buf_truncate(state_path, state_path_len);
+	return error;
+}
+
+GIT_INLINE(int) rebase_readint(
+	size_t *out, git_buf *asc_out, git_buf *state_path, const char *filename)
+{
+	int32_t num;
+	const char *eol;
+	int error = 0;
+
+	if ((error = rebase_readfile(asc_out, state_path, filename)) < 0)
+		return error;
+
+	if (git__strtol32(&num, asc_out->ptr, &eol, 10) < 0 || num < 0 || *eol) {
+		giterr_set(GITERR_REBASE, "the file '%s' contains an invalid numeric value", filename);
+		return -1;
+	}
+
+	*out = (size_t) num;
+
+	return 0;
+}
+
+GIT_INLINE(int) rebase_readoid(
+	git_oid *out, git_buf *str_out, git_buf *state_path, const char *filename)
+{
+	int error;
+
+	if ((error = rebase_readfile(str_out, state_path, filename)) < 0)
+		return error;
+
+	if (str_out->size != GIT_OID_HEXSZ || git_oid_fromstr(out, str_out->ptr) < 0) {
+		giterr_set(GITERR_REBASE, "the file '%s' contains an invalid object ID", filename);
+		return -1;
+	}
+
+	return 0;
+}
+
+static git_rebase_operation *rebase_operation_alloc(
+	git_rebase *rebase,
+	git_rebase_operation_t type,
+	git_oid *id,
+	const char *exec)
+{
+	git_rebase_operation *operation;
+
+	assert((type == GIT_REBASE_OPERATION_EXEC) == !id);
+	assert((type == GIT_REBASE_OPERATION_EXEC) == !!exec);
+
+	if ((operation = git_array_alloc(rebase->operations)) == NULL)
+		return NULL;
+
+	operation->type = type;
+	git_oid_cpy((git_oid *)&operation->id, id);
+	operation->exec = exec;
+
+	return operation;
+}
+
+static int rebase_open_merge(git_rebase *rebase)
+{
+	git_buf state_path = GIT_BUF_INIT, buf = GIT_BUF_INIT, cmt = GIT_BUF_INIT;
+	git_oid id;
+	git_rebase_operation *operation;
+	size_t i, msgnum = 0, end;
+	int error;
+
+	if ((error = git_buf_puts(&state_path, rebase->state_path)) < 0)
+		goto done;
+
+	/* Read 'msgnum' if it exists (otherwise, let msgnum = 0) */
+	if ((error = rebase_readint(&msgnum, &buf, &state_path, MSGNUM_FILE)) < 0 &&
+		error != GIT_ENOTFOUND)
+		goto done;
+
+	if (msgnum) {
+		rebase->started = 1;
+		rebase->current = msgnum - 1;
+	}
+
+	/* Read 'end' */
+	if ((error = rebase_readint(&end, &buf, &state_path, END_FILE)) < 0)
+		goto done;
+
+	/* Read 'current' if it exists */
+	if ((error = rebase_readoid(&id, &buf, &state_path, CURRENT_FILE)) < 0 &&
+		error != GIT_ENOTFOUND)
+		goto done;
+
+	/* Read cmt.* */
+	git_array_init_to_size(rebase->operations, end);
+	GITERR_CHECK_ARRAY(rebase->operations);
+
+	for (i = 0; i < end; i++) {
+		git_buf_clear(&cmt);
+
+		if ((error = git_buf_printf(&cmt, "cmt.%" PRIuZ, (i+1))) < 0 ||
+			(error = rebase_readoid(&id, &buf, &state_path, cmt.ptr)) < 0)
+			goto done;
+
+		operation = rebase_operation_alloc(rebase, GIT_REBASE_OPERATION_PICK, &id, NULL);
+		GITERR_CHECK_ALLOC(operation);
+	}
+
+	/* Read 'onto_name' */
+	if ((error = rebase_readfile(&buf, &state_path, ONTO_NAME_FILE)) < 0)
+		goto done;
+
+	rebase->onto_name = git_buf_detach(&buf);
+
+done:
+	git_buf_free(&cmt);
+	git_buf_free(&state_path);
+	git_buf_free(&buf);
+
+	return error;
+}
+
+static int rebase_alloc(git_rebase **out, const git_rebase_options *rebase_opts)
+{
+	git_rebase *rebase = git__calloc(1, sizeof(git_rebase));
+	GITERR_CHECK_ALLOC(rebase);
+
+	*out = NULL;
+
+	if (rebase_opts)
+		memcpy(&rebase->options, rebase_opts, sizeof(git_rebase_options));
+	else
+		git_rebase_init_options(&rebase->options, GIT_REBASE_OPTIONS_VERSION);
+
+	if (rebase_opts && rebase_opts->rewrite_notes_ref) {
+		rebase->options.rewrite_notes_ref = git__strdup(rebase_opts->rewrite_notes_ref);
+		GITERR_CHECK_ALLOC(rebase->options.rewrite_notes_ref);
+	}
+
+	*out = rebase;
+
+	return 0;
+}
+
+static int rebase_check_versions(const git_rebase_options *given_opts)
+{
+	GITERR_CHECK_VERSION(given_opts, GIT_REBASE_OPTIONS_VERSION, "git_rebase_options");
+
+	if (given_opts)
+		GITERR_CHECK_VERSION(&given_opts->checkout_options, GIT_CHECKOUT_OPTIONS_VERSION, "git_checkout_options");
+
+	return 0;
+}
+
+int git_rebase_open(
+	git_rebase **out,
+	git_repository *repo,
+	const git_rebase_options *given_opts)
+{
+	git_rebase *rebase;
+	git_buf path = GIT_BUF_INIT, orig_head_name = GIT_BUF_INIT,
+		orig_head_id = GIT_BUF_INIT, onto_id = GIT_BUF_INIT;
+	int state_path_len, error;
+
+	assert(repo);
+
+	if ((error = rebase_check_versions(given_opts)) < 0)
+		return error;
+
+	if (rebase_alloc(&rebase, given_opts) < 0)
+		return -1;
+
+	rebase->repo = repo;
+
+	if ((error = rebase_state_type(&rebase->type, &rebase->state_path, repo)) < 0)
+		goto done;
+
+	if (rebase->type == GIT_REBASE_TYPE_NONE) {
+		giterr_set(GITERR_REBASE, "there is no rebase in progress");
+		error = GIT_ENOTFOUND;
+		goto done;
+	}
+
+	if ((error = git_buf_puts(&path, rebase->state_path)) < 0)
+		goto done;
+
+	state_path_len = git_buf_len(&path);
+
+	if ((error = git_buf_joinpath(&path, path.ptr, HEAD_NAME_FILE)) < 0 ||
+		(error = git_futils_readbuffer(&orig_head_name, path.ptr)) < 0)
+		goto done;
+
+	git_buf_rtrim(&orig_head_name);
+
+	if (strcmp(ORIG_DETACHED_HEAD, orig_head_name.ptr) == 0)
+		rebase->head_detached = 1;
+
+	git_buf_truncate(&path, state_path_len);
+
+	if ((error = git_buf_joinpath(&path, path.ptr, ORIG_HEAD_FILE)) < 0)
+		goto done;
+
+	if (!git_path_isfile(path.ptr)) {
+		/* Previous versions of git.git used 'head' here; support that. */
+		git_buf_truncate(&path, state_path_len);
+
+		if ((error = git_buf_joinpath(&path, path.ptr, HEAD_FILE)) < 0)
+			goto done;
+	}
+
+	if ((error = git_futils_readbuffer(&orig_head_id, path.ptr)) < 0)
+		goto done;
+
+	git_buf_rtrim(&orig_head_id);
+
+	if ((error = git_oid_fromstr(&rebase->orig_head_id, orig_head_id.ptr)) < 0)
+		goto done;
+
+	git_buf_truncate(&path, state_path_len);
+
+	if ((error = git_buf_joinpath(&path, path.ptr, ONTO_FILE)) < 0 ||
+		(error = git_futils_readbuffer(&onto_id, path.ptr)) < 0)
+		goto done;
+
+	git_buf_rtrim(&onto_id);
+
+	if ((error = git_oid_fromstr(&rebase->onto_id, onto_id.ptr)) < 0)
+		goto done;
+
+	if (!rebase->head_detached)
+		rebase->orig_head_name = git_buf_detach(&orig_head_name);
+
+	switch (rebase->type) {
+	case GIT_REBASE_TYPE_INTERACTIVE:
+		giterr_set(GITERR_REBASE, "interactive rebase is not supported");
+		error = -1;
+		break;
+	case GIT_REBASE_TYPE_MERGE:
+		error = rebase_open_merge(rebase);
+		break;
+	case GIT_REBASE_TYPE_APPLY:
+		giterr_set(GITERR_REBASE, "patch application rebase is not supported");
+		error = -1;
+		break;
+	default:
+		abort();
+	}
+
+done:
+	if (error == 0)
+		*out = rebase;
+	else
+		git_rebase_free(rebase);
+
+	git_buf_free(&path);
+	git_buf_free(&orig_head_name);
+	git_buf_free(&orig_head_id);
+	git_buf_free(&onto_id);
+	return error;
+}
+
+static int rebase_cleanup(git_rebase *rebase)
+{
+	if (!rebase || rebase->inmemory)
+		return 0;
+
+	return git_path_isdir(rebase->state_path) ?
+		git_futils_rmdir_r(rebase->state_path, NULL, GIT_RMDIR_REMOVE_FILES) :
+		0;
+}
+
+static int rebase_setupfile(git_rebase *rebase, const char *filename, int flags, const char *fmt, ...)
+{
+	git_buf path = GIT_BUF_INIT,
+		contents = GIT_BUF_INIT;
+	va_list ap;
+	int error;
+
+	va_start(ap, fmt);
+	git_buf_vprintf(&contents, fmt, ap);
+	va_end(ap);
+
+	if ((error = git_buf_joinpath(&path, rebase->state_path, filename)) == 0)
+		error = git_futils_writebuffer(&contents, path.ptr, flags, REBASE_FILE_MODE);
+
+	git_buf_free(&path);
+	git_buf_free(&contents);
+
+	return error;
+}
+
+static const char *rebase_onto_name(const git_annotated_commit *onto)
+{
+	if (onto->ref_name && git__strncmp(onto->ref_name, "refs/heads/", 11) == 0)
+		return onto->ref_name + 11;
+	else if (onto->ref_name)
+		return onto->ref_name;
+	else
+		return onto->id_str;
+}
+
+static int rebase_setupfiles_merge(git_rebase *rebase)
+{
+	git_buf commit_filename = GIT_BUF_INIT;
+	char id_str[GIT_OID_HEXSZ];
+	git_rebase_operation *operation;
+	size_t i;
+	int error = 0;
+
+	if ((error = rebase_setupfile(rebase, END_FILE, 0, "%" PRIuZ "\n", git_array_size(rebase->operations))) < 0 ||
+		(error = rebase_setupfile(rebase, ONTO_NAME_FILE, 0, "%s\n", rebase->onto_name)) < 0)
+		goto done;
+
+	for (i = 0; i < git_array_size(rebase->operations); i++) {
+		operation = git_array_get(rebase->operations, i);
+
+		git_buf_clear(&commit_filename);
+		git_buf_printf(&commit_filename, CMT_FILE_FMT, i+1);
+
+		git_oid_fmt(id_str, &operation->id);
+
+		if ((error = rebase_setupfile(rebase, commit_filename.ptr, 0,
+				"%.*s\n", GIT_OID_HEXSZ, id_str)) < 0)
+			goto done;
+	}
+
+done:
+	git_buf_free(&commit_filename);
+	return error;
+}
+
+static int rebase_setupfiles(git_rebase *rebase)
+{
+	char onto[GIT_OID_HEXSZ], orig_head[GIT_OID_HEXSZ];
+	const char *orig_head_name;
+
+	git_oid_fmt(onto, &rebase->onto_id);
+	git_oid_fmt(orig_head, &rebase->orig_head_id);
+
+	if (p_mkdir(rebase->state_path, REBASE_DIR_MODE) < 0) {
+		giterr_set(GITERR_OS, "failed to create rebase directory '%s'", rebase->state_path);
+		return -1;
+	}
+
+	orig_head_name = rebase->head_detached ? ORIG_DETACHED_HEAD :
+		rebase->orig_head_name;
+
+	if (git_repository__set_orig_head(rebase->repo, &rebase->orig_head_id) < 0 ||
+		rebase_setupfile(rebase, HEAD_NAME_FILE, 0, "%s\n", orig_head_name) < 0 ||
+		rebase_setupfile(rebase, ONTO_FILE, 0, "%.*s\n", GIT_OID_HEXSZ, onto) < 0 ||
+		rebase_setupfile(rebase, ORIG_HEAD_FILE, 0, "%.*s\n", GIT_OID_HEXSZ, orig_head) < 0 ||
+		rebase_setupfile(rebase, QUIET_FILE, 0, rebase->quiet ? "t\n" : "\n") < 0)
+		return -1;
+
+	return rebase_setupfiles_merge(rebase);
+}
+
+int git_rebase_init_options(git_rebase_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_rebase_options, GIT_REBASE_OPTIONS_INIT);
+	return 0;
+}
+
+static int rebase_ensure_not_in_progress(git_repository *repo)
+{
+	int error;
+	git_rebase_type_t type;
+
+	if ((error = rebase_state_type(&type, NULL, repo)) < 0)
+		return error;
+
+	if (type != GIT_REBASE_TYPE_NONE) {
+		giterr_set(GITERR_REBASE, "there is an existing rebase in progress");
+		return -1;
+	}
+
+	return 0;
+}
+
+static int rebase_ensure_not_dirty(
+	git_repository *repo,
+	bool check_index,
+	bool check_workdir,
+	int fail_with)
+{
+	git_tree *head = NULL;
+	git_index *index = NULL;
+	git_diff *diff = NULL;
+	int error = 0;
+
+	if (check_index) {
+		if ((error = git_repository_head_tree(&head, repo)) < 0 ||
+			(error = git_repository_index(&index, repo)) < 0 ||
+			(error = git_diff_tree_to_index(&diff, repo, head, index, NULL)) < 0)
+			goto done;
+
+		if (git_diff_num_deltas(diff) > 0) {
+			giterr_set(GITERR_REBASE, "uncommitted changes exist in index");
+			error = fail_with;
+			goto done;
+		}
+
+		git_diff_free(diff);
+		diff = NULL;
+	}
+
+	if (check_workdir) {
+		git_diff_options diff_opts = GIT_DIFF_OPTIONS_INIT;
+		diff_opts.ignore_submodules = GIT_SUBMODULE_IGNORE_UNTRACKED;
+		if ((error = git_diff_index_to_workdir(&diff, repo, index, &diff_opts)) < 0)
+			goto done;
+
+		if (git_diff_num_deltas(diff) > 0) {
+			giterr_set(GITERR_REBASE, "unstaged changes exist in workdir");
+			error = fail_with;
+			goto done;
+		}
+	}
+
+done:
+	git_diff_free(diff);
+	git_index_free(index);
+	git_tree_free(head);
+
+	return error;
+}
+
+static int rebase_init_operations(
+	git_rebase *rebase,
+	git_repository *repo,
+	const git_annotated_commit *branch,
+	const git_annotated_commit *upstream,
+	const git_annotated_commit *onto)
+{
+	git_revwalk *revwalk = NULL;
+	git_commit *commit;
+	git_oid id;
+	bool merge;
+	git_rebase_operation *operation;
+	int error;
+
+	if (!upstream)
+		upstream = onto;
+
+	if ((error = git_revwalk_new(&revwalk, rebase->repo)) < 0 ||
+		(error = git_revwalk_push(revwalk, git_annotated_commit_id(branch))) < 0 ||
+		(error = git_revwalk_hide(revwalk, git_annotated_commit_id(upstream))) < 0)
+		goto done;
+
+	git_revwalk_sorting(revwalk, GIT_SORT_REVERSE);
+
+	while ((error = git_revwalk_next(&id, revwalk)) == 0) {
+		if ((error = git_commit_lookup(&commit, repo, &id)) < 0)
+			goto done;
+
+		merge = (git_commit_parentcount(commit) > 1);
+		git_commit_free(commit);
+
+		if (merge)
+			continue;
+
+		operation = rebase_operation_alloc(rebase, GIT_REBASE_OPERATION_PICK, &id, NULL);
+		GITERR_CHECK_ALLOC(operation);
+	}
+
+	error = 0;
+
+done:
+	git_revwalk_free(revwalk);
+	return error;
+}
+
+static int rebase_init_merge(
+	git_rebase *rebase,
+	git_repository *repo,
+	const git_annotated_commit *branch,
+	const git_annotated_commit *upstream,
+	const git_annotated_commit *onto)
+{
+	git_reference *head_ref = NULL;
+	git_commit *onto_commit = NULL;
+	git_buf reflog = GIT_BUF_INIT;
+	git_buf state_path = GIT_BUF_INIT;
+	int error;
+
+	GIT_UNUSED(upstream);
+
+	if ((error = git_buf_joinpath(&state_path, repo->gitdir, REBASE_MERGE_DIR)) < 0)
+		goto done;
+
+	rebase->state_path = git_buf_detach(&state_path);
+	GITERR_CHECK_ALLOC(rebase->state_path);
+
+	if (branch->ref_name && strcmp(branch->ref_name, "HEAD")) {
+		rebase->orig_head_name = git__strdup(branch->ref_name);
+		GITERR_CHECK_ALLOC(rebase->orig_head_name);
+	} else {
+		rebase->head_detached = 1;
+	}
+
+	rebase->onto_name = git__strdup(rebase_onto_name(onto));
+	GITERR_CHECK_ALLOC(rebase->onto_name);
+
+	rebase->quiet = rebase->options.quiet;
+
+	git_oid_cpy(&rebase->orig_head_id, git_annotated_commit_id(branch));
+	git_oid_cpy(&rebase->onto_id, git_annotated_commit_id(onto));
+
+	if ((error = rebase_setupfiles(rebase)) < 0 ||
+		(error = git_buf_printf(&reflog,
+			"rebase: checkout %s", rebase_onto_name(onto))) < 0 ||
+		(error = git_commit_lookup(
+			&onto_commit, repo, git_annotated_commit_id(onto))) < 0 ||
+		(error = git_checkout_tree(repo,
+			(git_object *)onto_commit, &rebase->options.checkout_options)) < 0 ||
+		(error = git_reference_create(&head_ref, repo, GIT_HEAD_FILE,
+			git_annotated_commit_id(onto), 1, reflog.ptr)) < 0)
+		goto done;
+
+done:
+	git_reference_free(head_ref);
+	git_commit_free(onto_commit);
+	git_buf_free(&reflog);
+	git_buf_free(&state_path);
+
+	return error;
+}
+
+static int rebase_init_inmemory(
+	git_rebase *rebase,
+	git_repository *repo,
+	const git_annotated_commit *branch,
+	const git_annotated_commit *upstream,
+	const git_annotated_commit *onto)
+{
+	GIT_UNUSED(branch);
+	GIT_UNUSED(upstream);
+
+	return git_commit_lookup(
+		&rebase->last_commit, repo, git_annotated_commit_id(onto));
+}
+
+int git_rebase_init(
+	git_rebase **out,
+	git_repository *repo,
+	const git_annotated_commit *branch,
+	const git_annotated_commit *upstream,
+	const git_annotated_commit *onto,
+	const git_rebase_options *given_opts)
+{
+	git_rebase *rebase = NULL;
+	git_annotated_commit *head_branch = NULL;
+	git_reference *head_ref = NULL;
+	bool inmemory = (given_opts && given_opts->inmemory);
+	int error;
+
+	assert(repo && (upstream || onto));
+
+	*out = NULL;
+
+	if (!onto)
+		onto = upstream;
+
+	if ((error = rebase_check_versions(given_opts)) < 0)
+		goto done;
+
+	if (!inmemory) {
+		if ((error = git_repository__ensure_not_bare(repo, "rebase")) < 0 ||
+			(error = rebase_ensure_not_in_progress(repo)) < 0 ||
+			(error = rebase_ensure_not_dirty(repo, true, true, GIT_ERROR)) < 0)
+			goto done;
+	}
+
+	if (!branch) {
+		if ((error = git_repository_head(&head_ref, repo)) < 0 ||
+			(error = git_annotated_commit_from_ref(&head_branch, repo, head_ref)) < 0)
+			goto done;
+
+		branch = head_branch;
+	}
+
+	if (rebase_alloc(&rebase, given_opts) < 0)
+		return -1;
+
+	rebase->repo = repo;
+	rebase->inmemory = inmemory;
+	rebase->type = GIT_REBASE_TYPE_MERGE;
+
+	if ((error = rebase_init_operations(rebase, repo, branch, upstream, onto)) < 0)
+		goto done;
+
+	if (inmemory)
+		error = rebase_init_inmemory(rebase, repo, branch, upstream, onto);
+	else
+		error = rebase_init_merge(rebase, repo, branch ,upstream, onto);
+
+	if (error == 0)
+		*out = rebase;
+
+done:
+	git_reference_free(head_ref);
+	git_annotated_commit_free(head_branch);
+
+	if (error < 0) {
+		rebase_cleanup(rebase);
+		git_rebase_free(rebase);
+	}
+
+	return error;
+}
+
+static void normalize_checkout_options_for_apply(
+	git_checkout_options *checkout_opts,
+	git_rebase *rebase,
+	git_commit *current_commit)
+{
+	memcpy(checkout_opts, &rebase->options.checkout_options, sizeof(git_checkout_options));
+
+	if (!checkout_opts->ancestor_label)
+		checkout_opts->ancestor_label = "ancestor";
+
+	if (rebase->type == GIT_REBASE_TYPE_MERGE) {
+		if (!checkout_opts->our_label)
+			checkout_opts->our_label = rebase->onto_name;
+
+		if (!checkout_opts->their_label)
+			checkout_opts->their_label = git_commit_summary(current_commit);
+	} else {
+		abort();
+	}
+}
+
+GIT_INLINE(int) rebase_movenext(git_rebase *rebase)
+{
+	size_t next = rebase->started ? rebase->current + 1 : 0;
+
+	if (next == git_array_size(rebase->operations))
+		return GIT_ITEROVER;
+
+	rebase->started = 1;
+	rebase->current = next;
+
+	return 0;
+}
+
+static int rebase_next_merge(
+	git_rebase_operation **out,
+	git_rebase *rebase)
+{
+	git_buf path = GIT_BUF_INIT;
+	git_commit *current_commit = NULL, *parent_commit = NULL;
+	git_tree *current_tree = NULL, *head_tree = NULL, *parent_tree = NULL;
+	git_index *index = NULL;
+	git_indexwriter indexwriter = GIT_INDEXWRITER_INIT;
+	git_rebase_operation *operation;
+	git_checkout_options checkout_opts;
+	char current_idstr[GIT_OID_HEXSZ];
+	unsigned int parent_count;
+	int error;
+
+	*out = NULL;
+
+	operation = git_array_get(rebase->operations, rebase->current);
+
+	if ((error = git_commit_lookup(&current_commit, rebase->repo, &operation->id)) < 0 ||
+		(error = git_commit_tree(&current_tree, current_commit)) < 0 ||
+		(error = git_repository_head_tree(&head_tree, rebase->repo)) < 0)
+		goto done;
+
+	if ((parent_count = git_commit_parentcount(current_commit)) > 1) {
+		giterr_set(GITERR_REBASE, "cannot rebase a merge commit");
+		error = -1;
+		goto done;
+	} else if (parent_count) {
+		if ((error = git_commit_parent(&parent_commit, current_commit, 0)) < 0 ||
+			(error = git_commit_tree(&parent_tree, parent_commit)) < 0)
+			goto done;
+	}
+
+	git_oid_fmt(current_idstr, &operation->id);
+
+	normalize_checkout_options_for_apply(&checkout_opts, rebase, current_commit);
+
+	if ((error = git_indexwriter_init_for_operation(&indexwriter, rebase->repo, &checkout_opts.checkout_strategy)) < 0 ||
+		(error = rebase_setupfile(rebase, MSGNUM_FILE, 0, "%" PRIuZ "\n", rebase->current+1)) < 0 ||
+		(error = rebase_setupfile(rebase, CURRENT_FILE, 0, "%.*s\n", GIT_OID_HEXSZ, current_idstr)) < 0 ||
+		(error = git_merge_trees(&index, rebase->repo, parent_tree, head_tree, current_tree, &rebase->options.merge_options)) < 0 ||
+		(error = git_merge__check_result(rebase->repo, index)) < 0 ||
+		(error = git_checkout_index(rebase->repo, index, &checkout_opts)) < 0 ||
+		(error = git_indexwriter_commit(&indexwriter)) < 0)
+		goto done;
+
+	*out = operation;
+
+done:
+	git_indexwriter_cleanup(&indexwriter);
+	git_index_free(index);
+	git_tree_free(current_tree);
+	git_tree_free(head_tree);
+	git_tree_free(parent_tree);
+	git_commit_free(parent_commit);
+	git_commit_free(current_commit);
+	git_buf_free(&path);
+
+	return error;
+}
+
+static int rebase_next_inmemory(
+	git_rebase_operation **out,
+	git_rebase *rebase)
+{
+	git_commit *current_commit = NULL, *parent_commit = NULL;
+	git_tree *current_tree = NULL, *head_tree = NULL, *parent_tree = NULL;
+	git_rebase_operation *operation;
+	git_index *index = NULL;
+	unsigned int parent_count;
+	int error;
+
+	*out = NULL;
+
+	operation = git_array_get(rebase->operations, rebase->current);
+
+	if ((error = git_commit_lookup(&current_commit, rebase->repo, &operation->id)) < 0 ||
+		(error = git_commit_tree(&current_tree, current_commit)) < 0)
+		goto done;
+
+	if ((parent_count = git_commit_parentcount(current_commit)) > 1) {
+		giterr_set(GITERR_REBASE, "cannot rebase a merge commit");
+		error = -1;
+		goto done;
+	} else if (parent_count) {
+		if ((error = git_commit_parent(&parent_commit, current_commit, 0)) < 0 ||
+			(error = git_commit_tree(&parent_tree, parent_commit)) < 0)
+			goto done;
+	}
+
+	if ((error = git_commit_tree(&head_tree, rebase->last_commit)) < 0 ||
+		(error = git_merge_trees(&index, rebase->repo, parent_tree, head_tree, current_tree, &rebase->options.merge_options)) < 0)
+		goto done;
+
+	if (!rebase->index) {
+		rebase->index = index;
+		index = NULL;
+	} else {
+		if ((error = git_index_read_index(rebase->index, index)) < 0)
+			goto done;
+	}
+
+	*out = operation;
+
+done:
+	git_commit_free(current_commit);
+	git_commit_free(parent_commit);
+	git_tree_free(current_tree);
+	git_tree_free(head_tree);
+	git_tree_free(parent_tree);
+	git_index_free(index);
+
+	return error;
+}
+
+int git_rebase_next(
+	git_rebase_operation **out,
+	git_rebase *rebase)
+{
+	int error;
+
+	assert(out && rebase);
+
+	if ((error = rebase_movenext(rebase)) < 0)
+		return error;
+
+	if (rebase->inmemory)
+		error = rebase_next_inmemory(out, rebase);
+	else if (rebase->type == GIT_REBASE_TYPE_MERGE)
+		error = rebase_next_merge(out, rebase);
+	else
+		abort();
+
+	return error;
+}
+
+int git_rebase_inmemory_index(
+	git_index **out,
+	git_rebase *rebase)
+{
+	assert(out && rebase && rebase->index);
+
+	GIT_REFCOUNT_INC(rebase->index);
+	*out = rebase->index;
+
+	return 0;
+}
+
+static int rebase_commit__create(
+	git_commit **out,
+	git_rebase *rebase,
+	git_index *index,
+	git_commit *parent_commit,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message)
+{
+	git_rebase_operation *operation;
+	git_commit *current_commit = NULL, *commit = NULL;
+	git_tree *parent_tree = NULL, *tree = NULL;
+	git_oid tree_id, commit_id;
+	int error;
+
+	operation = git_array_get(rebase->operations, rebase->current);
+
+	if (git_index_has_conflicts(index)) {
+		giterr_set(GITERR_REBASE, "conflicts have not been resolved");
+		error = GIT_EUNMERGED;
+		goto done;
+	}
+
+	if ((error = git_commit_lookup(&current_commit, rebase->repo, &operation->id)) < 0 ||
+		(error = git_commit_tree(&parent_tree, parent_commit)) < 0 ||
+		(error = git_index_write_tree_to(&tree_id, index, rebase->repo)) < 0 ||
+		(error = git_tree_lookup(&tree, rebase->repo, &tree_id)) < 0)
+		goto done;
+
+	if (git_oid_equal(&tree_id, git_tree_id(parent_tree))) {
+		giterr_set(GITERR_REBASE, "this patch has already been applied");
+		error = GIT_EAPPLIED;
+		goto done;
+	}
+
+	if (!author)
+		author = git_commit_author(current_commit);
+
+	if (!message) {
+		message_encoding = git_commit_message_encoding(current_commit);
+		message = git_commit_message(current_commit);
+	}
+
+	if ((error = git_commit_create(&commit_id, rebase->repo, NULL, author,
+		committer, message_encoding, message, tree, 1,
+		(const git_commit **)&parent_commit)) < 0 ||
+		(error = git_commit_lookup(&commit, rebase->repo, &commit_id)) < 0)
+		goto done;
+
+	*out = commit;
+
+done:
+	if (error < 0)
+		git_commit_free(commit);
+
+	git_commit_free(current_commit);
+	git_tree_free(parent_tree);
+	git_tree_free(tree);
+
+	return error;
+}
+
+static int rebase_commit_merge(
+	git_oid *commit_id,
+	git_rebase *rebase,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message)
+{
+	git_rebase_operation *operation;
+	git_reference *head = NULL;
+	git_commit *head_commit = NULL, *commit = NULL;
+	git_index *index = NULL;
+	char old_idstr[GIT_OID_HEXSZ], new_idstr[GIT_OID_HEXSZ];
+	int error;
+
+	operation = git_array_get(rebase->operations, rebase->current);
+	assert(operation);
+
+	if ((error = rebase_ensure_not_dirty(rebase->repo, false, true, GIT_EUNMERGED)) < 0 ||
+		(error = git_repository_head(&head, rebase->repo)) < 0 ||
+		(error = git_reference_peel((git_object **)&head_commit, head, GIT_OBJ_COMMIT)) < 0 ||
+		(error = git_repository_index(&index, rebase->repo)) < 0 ||
+		(error = rebase_commit__create(&commit, rebase, index, head_commit,
+			author, committer, message_encoding, message)) < 0 ||
+		(error = git_reference__update_for_commit(
+			rebase->repo, NULL, "HEAD", git_commit_id(commit), "rebase")) < 0)
+		goto done;
+
+	git_oid_fmt(old_idstr, &operation->id);
+	git_oid_fmt(new_idstr, git_commit_id(commit));
+
+	if ((error = rebase_setupfile(rebase, REWRITTEN_FILE, O_CREAT|O_WRONLY|O_APPEND,
+		"%.*s %.*s\n", GIT_OID_HEXSZ, old_idstr, GIT_OID_HEXSZ, new_idstr)) < 0)
+		goto done;
+
+	git_oid_cpy(commit_id, git_commit_id(commit));
+
+done:
+	git_index_free(index);
+	git_reference_free(head);
+	git_commit_free(head_commit);
+	git_commit_free(commit);
+	return error;
+}
+
+static int rebase_commit_inmemory(
+	git_oid *commit_id,
+	git_rebase *rebase,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message)
+{
+	git_commit *commit = NULL;
+	int error = 0;
+
+	assert(rebase->index);
+	assert(rebase->last_commit);
+	assert(rebase->current < rebase->operations.size);
+
+	if ((error = rebase_commit__create(&commit, rebase, rebase->index,
+		rebase->last_commit, author, committer, message_encoding, message)) < 0)
+		goto done;
+
+	git_commit_free(rebase->last_commit);
+	rebase->last_commit = commit;
+
+	git_oid_cpy(commit_id, git_commit_id(commit));
+
+done:
+	if (error < 0)
+		git_commit_free(commit);
+
+	return error;
+}
+
+int git_rebase_commit(
+	git_oid *id,
+	git_rebase *rebase,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message)
+{
+	int error;
+
+	assert(rebase && committer);
+
+	if (rebase->inmemory)
+		error = rebase_commit_inmemory(
+			id, rebase, author, committer, message_encoding, message);
+	else if (rebase->type == GIT_REBASE_TYPE_MERGE)
+		error = rebase_commit_merge(
+			id, rebase, author, committer, message_encoding, message);
+	else
+		abort();
+
+	return error;
+}
+
+int git_rebase_abort(git_rebase *rebase)
+{
+	git_reference *orig_head_ref = NULL;
+	git_commit *orig_head_commit = NULL;
+	int error;
+
+	assert(rebase);
+
+	if (rebase->inmemory)
+		return 0;
+
+	error = rebase->head_detached ?
+		git_reference_create(&orig_head_ref, rebase->repo, GIT_HEAD_FILE,
+			 &rebase->orig_head_id, 1, "rebase: aborting") :
+		git_reference_symbolic_create(
+			&orig_head_ref, rebase->repo, GIT_HEAD_FILE, rebase->orig_head_name, 1,
+			"rebase: aborting");
+
+	if (error < 0)
+		goto done;
+
+	if ((error = git_commit_lookup(
+			&orig_head_commit, rebase->repo, &rebase->orig_head_id)) < 0 ||
+		(error = git_reset(rebase->repo, (git_object *)orig_head_commit,
+			GIT_RESET_HARD, &rebase->options.checkout_options)) < 0)
+		goto done;
+
+	error = rebase_cleanup(rebase);
+
+done:
+	git_commit_free(orig_head_commit);
+	git_reference_free(orig_head_ref);
+
+	return error;
+}
+
+static int notes_ref_lookup(git_buf *out, git_rebase *rebase)
+{
+	git_config *config = NULL;
+	int do_rewrite, error;
+
+	if (rebase->options.rewrite_notes_ref) {
+		git_buf_attach_notowned(out,
+			rebase->options.rewrite_notes_ref,
+			strlen(rebase->options.rewrite_notes_ref));
+		return 0;
+	}
+
+	if ((error = git_repository_config(&config, rebase->repo)) < 0 ||
+		(error = git_config_get_bool(&do_rewrite, config, "notes.rewrite.rebase")) < 0) {
+
+		if (error != GIT_ENOTFOUND)
+			goto done;
+
+		giterr_clear();
+		do_rewrite = 1;
+	}
+
+	error = do_rewrite ?
+		git_config_get_string_buf(out, config, "notes.rewriteref") :
+		GIT_ENOTFOUND;
+
+done:
+	git_config_free(config);
+	return error;
+}
+
+static int rebase_copy_note(
+	git_rebase *rebase,
+	const char *notes_ref,
+	git_oid *from,
+	git_oid *to,
+	const git_signature *committer)
+{
+	git_note *note = NULL;
+	git_oid note_id;
+	git_signature *who = NULL;
+	int error;
+
+	if ((error = git_note_read(&note, rebase->repo, notes_ref, from)) < 0) {
+		if (error == GIT_ENOTFOUND) {
+			giterr_clear();
+			error = 0;
+		}
+
+		goto done;
+	}
+
+	if (!committer) {
+		if((error = git_signature_default(&who, rebase->repo)) < 0) {
+			if (error != GIT_ENOTFOUND ||
+				(error = git_signature_now(&who, "unknown", "unknown")) < 0)
+				goto done;
+
+			giterr_clear();
+		}
+
+		committer = who;
+	}
+
+	error = git_note_create(&note_id, rebase->repo, notes_ref,
+		git_note_author(note), committer, to, git_note_message(note), 0);
+
+done:
+	git_note_free(note);
+	git_signature_free(who);
+
+	return error;
+}
+
+static int rebase_copy_notes(
+	git_rebase *rebase,
+	const git_signature *committer)
+{
+	git_buf path = GIT_BUF_INIT, rewritten = GIT_BUF_INIT, notes_ref = GIT_BUF_INIT;
+	char *pair_list, *fromstr, *tostr, *end;
+	git_oid from, to;
+	unsigned int linenum = 1;
+	int error = 0;
+
+	if ((error = notes_ref_lookup(&notes_ref, rebase)) < 0) {
+		if (error == GIT_ENOTFOUND) {
+			giterr_clear();
+			error = 0;
+		}
+
+		goto done;
+	}
+
+	if ((error = git_buf_joinpath(&path, rebase->state_path, REWRITTEN_FILE)) < 0 ||
+		(error = git_futils_readbuffer(&rewritten, path.ptr)) < 0)
+		goto done;
+
+	pair_list = rewritten.ptr;
+
+	while (*pair_list) {
+		fromstr = pair_list;
+
+		if ((end = strchr(fromstr, '\n')) == NULL)
+			goto on_error;
+
+		pair_list = end+1;
+		*end = '\0';
+
+		if ((end = strchr(fromstr, ' ')) == NULL)
+			goto on_error;
+
+		tostr = end+1;
+		*end = '\0';
+
+		if (strlen(fromstr) != GIT_OID_HEXSZ ||
+			strlen(tostr) != GIT_OID_HEXSZ ||
+			git_oid_fromstr(&from, fromstr) < 0 ||
+			git_oid_fromstr(&to, tostr) < 0)
+			goto on_error;
+
+		if ((error = rebase_copy_note(rebase, notes_ref.ptr, &from, &to, committer)) < 0)
+			goto done;
+
+		linenum++;
+	}
+
+	goto done;
+
+on_error:
+	giterr_set(GITERR_REBASE, "invalid rewritten file at line %d", linenum);
+	error = -1;
+
+done:
+	git_buf_free(&rewritten);
+	git_buf_free(&path);
+	git_buf_free(&notes_ref);
+
+	return error;
+}
+
+static int return_to_orig_head(git_rebase *rebase)
+{
+	git_reference *terminal_ref = NULL, *branch_ref = NULL, *head_ref = NULL;
+	git_commit *terminal_commit = NULL;
+	git_buf branch_msg = GIT_BUF_INIT, head_msg = GIT_BUF_INIT;
+	char onto[GIT_OID_HEXSZ];
+	int error = 0;
+
+	git_oid_fmt(onto, &rebase->onto_id);
+
+	if ((error = git_buf_printf(&branch_msg,
+			"rebase finished: %s onto %.*s",
+			rebase->orig_head_name, GIT_OID_HEXSZ, onto)) == 0 &&
+		(error = git_buf_printf(&head_msg,
+			"rebase finished: returning to %s",
+			rebase->orig_head_name)) == 0 &&
+		(error = git_repository_head(&terminal_ref, rebase->repo)) == 0 &&
+		(error = git_reference_peel((git_object **)&terminal_commit,
+			terminal_ref, GIT_OBJ_COMMIT)) == 0 &&
+		(error = git_reference_create_matching(&branch_ref,
+			rebase->repo, rebase->orig_head_name,
+			git_commit_id(terminal_commit), 1,
+			&rebase->orig_head_id, branch_msg.ptr)) == 0)
+		error = git_reference_symbolic_create(&head_ref,
+			rebase->repo, GIT_HEAD_FILE, rebase->orig_head_name, 1,
+			head_msg.ptr);
+
+	git_buf_free(&head_msg);
+	git_buf_free(&branch_msg);
+	git_commit_free(terminal_commit);
+	git_reference_free(head_ref);
+	git_reference_free(branch_ref);
+	git_reference_free(terminal_ref);
+
+	return error;
+}
+
+int git_rebase_finish(
+	git_rebase *rebase,
+	const git_signature *signature)
+{
+	int error = 0;
+
+	assert(rebase);
+
+	if (rebase->inmemory)
+		return 0;
+
+	if (!rebase->head_detached)
+		error = return_to_orig_head(rebase);
+
+	if (error == 0 && (error = rebase_copy_notes(rebase, signature)) == 0)
+		error = rebase_cleanup(rebase);
+
+	return error;
+}
+
+size_t git_rebase_operation_entrycount(git_rebase *rebase)
+{
+	assert(rebase);
+
+	return git_array_size(rebase->operations);
+}
+
+size_t git_rebase_operation_current(git_rebase *rebase)
+{
+	assert(rebase);
+
+	return rebase->started ? rebase->current : GIT_REBASE_NO_OPERATION;
+}
+
+git_rebase_operation *git_rebase_operation_byindex(git_rebase *rebase, size_t idx)
+{
+	assert(rebase);
+
+	return git_array_get(rebase->operations, idx);
+}
+
+void git_rebase_free(git_rebase *rebase)
+{
+	if (rebase == NULL)
+		return;
+
+	git_index_free(rebase->index);
+	git_commit_free(rebase->last_commit);
+	git__free(rebase->onto_name);
+	git__free(rebase->orig_head_name);
+	git__free(rebase->state_path);
+	git_array_clear(rebase->operations);
+	git__free((char *)rebase->options.rewrite_notes_ref);
+	git__free(rebase);
+}

vendor/libgit2-sys/libgit2/src/refdb.c

diff --git a/vendor/libgit2-sys/libgit2/src/refdb.c b/vendor/libgit2-sys/libgit2/src/refdb.c
new file mode 100644
index 0000000..c162a15
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/refdb.c
@@ -0,0 +1,260 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "refdb.h"
+
+#include "git2/object.h"
+#include "git2/refs.h"
+#include "git2/refdb.h"
+#include "git2/sys/refdb_backend.h"
+
+#include "hash.h"
+#include "refs.h"
+#include "reflog.h"
+#include "posix.h"
+
+int git_refdb_new(git_refdb **out, git_repository *repo)
+{
+	git_refdb *db;
+
+	assert(out && repo);
+
+	db = git__calloc(1, sizeof(*db));
+	GITERR_CHECK_ALLOC(db);
+
+	db->repo = repo;
+
+	*out = db;
+	GIT_REFCOUNT_INC(db);
+	return 0;
+}
+
+int git_refdb_open(git_refdb **out, git_repository *repo)
+{
+	git_refdb *db;
+	git_refdb_backend *dir;
+
+	assert(out && repo);
+
+	*out = NULL;
+
+	if (git_refdb_new(&db, repo) < 0)
+		return -1;
+
+	/* Add the default (filesystem) backend */
+	if (git_refdb_backend_fs(&dir, repo) < 0) {
+		git_refdb_free(db);
+		return -1;
+	}
+
+	db->repo = repo;
+	db->backend = dir;
+
+	*out = db;
+	return 0;
+}
+
+static void refdb_free_backend(git_refdb *db)
+{
+	if (db->backend)
+		db->backend->free(db->backend);
+}
+
+int git_refdb_set_backend(git_refdb *db, git_refdb_backend *backend)
+{
+	refdb_free_backend(db);
+	db->backend = backend;
+
+	return 0;
+}
+
+int git_refdb_compress(git_refdb *db)
+{
+	assert(db);
+
+	if (db->backend->compress)
+		return db->backend->compress(db->backend);
+
+	return 0;
+}
+
+void git_refdb__free(git_refdb *db)
+{
+	refdb_free_backend(db);
+	git__memzero(db, sizeof(*db));
+	git__free(db);
+}
+
+void git_refdb_free(git_refdb *db)
+{
+	if (db == NULL)
+		return;
+
+	GIT_REFCOUNT_DEC(db, git_refdb__free);
+}
+
+int git_refdb_exists(int *exists, git_refdb *refdb, const char *ref_name)
+{
+	assert(exists && refdb && refdb->backend);
+
+	return refdb->backend->exists(exists, refdb->backend, ref_name);
+}
+
+int git_refdb_lookup(git_reference **out, git_refdb *db, const char *ref_name)
+{
+	git_reference *ref;
+	int error;
+
+	assert(db && db->backend && out && ref_name);
+
+	error = db->backend->lookup(&ref, db->backend, ref_name);
+	if (error < 0)
+		return error;
+
+	GIT_REFCOUNT_INC(db);
+	ref->db = db;
+
+	*out = ref;
+	return 0;
+}
+
+int git_refdb_iterator(git_reference_iterator **out, git_refdb *db, const char *glob)
+{
+	int error;
+
+	if (!db->backend || !db->backend->iterator) {
+		giterr_set(GITERR_REFERENCE, "this backend doesn't support iterators");
+		return -1;
+	}
+
+	if ((error = db->backend->iterator(out, db->backend, glob)) < 0)
+		return error;
+
+	GIT_REFCOUNT_INC(db);
+	(*out)->db = db;
+
+	return 0;
+}
+
+int git_refdb_iterator_next(git_reference **out, git_reference_iterator *iter)
+{
+	int error;
+
+	if ((error = iter->next(out, iter)) < 0)
+		return error;
+
+	GIT_REFCOUNT_INC(iter->db);
+	(*out)->db = iter->db;
+
+	return 0;
+}
+
+int git_refdb_iterator_next_name(const char **out, git_reference_iterator *iter)
+{
+	return iter->next_name(out, iter);
+}
+
+void git_refdb_iterator_free(git_reference_iterator *iter)
+{
+	GIT_REFCOUNT_DEC(iter->db, git_refdb__free);
+	iter->free(iter);
+}
+
+int git_refdb_write(git_refdb *db, git_reference *ref, int force, const git_signature *who, const char *message, const git_oid *old_id, const char *old_target)
+{
+	assert(db && db->backend);
+
+	GIT_REFCOUNT_INC(db);
+	ref->db = db;
+
+	return db->backend->write(db->backend, ref, force, who, message, old_id, old_target);
+}
+
+int git_refdb_rename(
+	git_reference **out,
+	git_refdb *db,
+	const char *old_name,
+	const char *new_name,
+	int force,
+	const git_signature *who,
+	const char *message)
+{
+	int error;
+
+	assert(db && db->backend);
+	error = db->backend->rename(out, db->backend, old_name, new_name, force, who, message);
+	if (error < 0)
+		return error;
+
+	if (out) {
+		GIT_REFCOUNT_INC(db);
+		(*out)->db = db;
+	}
+
+	return 0;
+}
+
+int git_refdb_delete(struct git_refdb *db, const char *ref_name, const git_oid *old_id, const char *old_target)
+{
+	assert(db && db->backend);
+	return db->backend->del(db->backend, ref_name, old_id, old_target);
+}
+
+int git_refdb_reflog_read(git_reflog **out, git_refdb *db,  const char *name)
+{
+	int error;
+
+	assert(db && db->backend);
+
+	if ((error = db->backend->reflog_read(out, db->backend, name)) < 0)
+		return error;
+
+	GIT_REFCOUNT_INC(db);
+	(*out)->db = db;
+
+	return 0;
+}
+
+int git_refdb_has_log(git_refdb *db, const char *refname)
+{
+	assert(db && refname);
+
+	return db->backend->has_log(db->backend, refname);
+}
+
+int git_refdb_ensure_log(git_refdb *db, const char *refname)
+{
+	assert(db && refname);
+
+	return db->backend->ensure_log(db->backend, refname);
+}
+
+int git_refdb_init_backend(git_refdb_backend *backend, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		backend, version, git_refdb_backend, GIT_REFDB_BACKEND_INIT);
+	return 0;
+}
+
+int git_refdb_lock(void **payload, git_refdb *db, const char *refname)
+{
+	assert(payload && db && refname);
+
+	if (!db->backend->lock) {
+		giterr_set(GITERR_REFERENCE, "backend does not support locking");
+		return -1;
+	}
+
+	return db->backend->lock(payload, db->backend, refname);
+}
+
+int git_refdb_unlock(git_refdb *db, void *payload, int success, int update_reflog, const git_reference *ref, const git_signature *sig, const char *message)
+{
+	assert(db);
+
+	return db->backend->unlock(db->backend, payload, success, update_reflog, ref, sig, message);
+}

vendor/libgit2-sys/libgit2/src/refdb.h

diff --git a/vendor/libgit2-sys/libgit2/src/refdb.h b/vendor/libgit2-sys/libgit2/src/refdb.h
new file mode 100644
index 0000000..2d4ec75
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/refdb.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_refdb_h__
+#define INCLUDE_refdb_h__
+
+#include "common.h"
+
+#include "git2/refdb.h"
+#include "repository.h"
+
+struct git_refdb {
+	git_refcount rc;
+	git_repository *repo;
+	git_refdb_backend *backend;
+};
+
+void git_refdb__free(git_refdb *db);
+
+int git_refdb_exists(
+	int *exists,
+	git_refdb *refdb,
+	const char *ref_name);
+
+int git_refdb_lookup(
+	git_reference **out,
+	git_refdb *refdb,
+	const char *ref_name);
+
+int git_refdb_rename(
+	git_reference **out,
+	git_refdb *db,
+	const char *old_name,
+	const char *new_name,
+	int force,
+	const git_signature *who,
+	const char *message);
+
+int git_refdb_iterator(git_reference_iterator **out, git_refdb *db, const char *glob);
+int git_refdb_iterator_next(git_reference **out, git_reference_iterator *iter);
+int git_refdb_iterator_next_name(const char **out, git_reference_iterator *iter);
+void git_refdb_iterator_free(git_reference_iterator *iter);
+
+int git_refdb_write(git_refdb *refdb, git_reference *ref, int force, const git_signature *who, const char *message, const git_oid *old_id, const char *old_target);
+int git_refdb_delete(git_refdb *refdb, const char *ref_name, const git_oid *old_id, const char *old_target);
+
+int git_refdb_reflog_read(git_reflog **out, git_refdb *db,  const char *name);
+int git_refdb_reflog_write(git_reflog *reflog);
+
+int git_refdb_has_log(git_refdb *db, const char *refname);
+int git_refdb_ensure_log(git_refdb *refdb, const char *refname);
+
+int git_refdb_lock(void **payload, git_refdb *db, const char *refname);
+int git_refdb_unlock(git_refdb *db, void *payload, int success, int update_reflog, const git_reference *ref, const git_signature *sig, const char *message);
+
+#endif

vendor/libgit2-sys/libgit2/src/refdb_fs.c

diff --git a/vendor/libgit2-sys/libgit2/src/refdb_fs.c b/vendor/libgit2-sys/libgit2/src/refdb_fs.c
new file mode 100644
index 0000000..9db6281
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/refdb_fs.c
@@ -0,0 +1,2095 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "refdb_fs.h"
+
+#include "refs.h"
+#include "hash.h"
+#include "repository.h"
+#include "fileops.h"
+#include "filebuf.h"
+#include "pack.h"
+#include "reflog.h"
+#include "refdb.h"
+#include "iterator.h"
+#include "sortedcache.h"
+#include "signature.h"
+
+#include <git2/tag.h>
+#include <git2/object.h>
+#include <git2/refdb.h>
+#include <git2/branch.h>
+#include <git2/sys/refdb_backend.h>
+#include <git2/sys/refs.h>
+#include <git2/sys/reflog.h>
+
+#define DEFAULT_NESTING_LEVEL	5
+#define MAX_NESTING_LEVEL		10
+
+enum {
+	PACKREF_HAS_PEEL = 1,
+	PACKREF_WAS_LOOSE = 2,
+	PACKREF_CANNOT_PEEL = 4,
+	PACKREF_SHADOWED = 8,
+};
+
+enum {
+	PEELING_NONE = 0,
+	PEELING_STANDARD,
+	PEELING_FULL
+};
+
+struct packref {
+	git_oid oid;
+	git_oid peel;
+	char flags;
+	char name[GIT_FLEX_ARRAY];
+};
+
+typedef struct refdb_fs_backend {
+	git_refdb_backend parent;
+
+	git_repository *repo;
+	/* path to git directory */
+	char *gitpath;
+	/* path to common objects' directory */
+	char *commonpath;
+
+	git_sortedcache *refcache;
+	int peeling_mode;
+	git_iterator_flag_t iterator_flags;
+	uint32_t direach_flags;
+	int fsync;
+} refdb_fs_backend;
+
+static int refdb_reflog_fs__delete(git_refdb_backend *_backend, const char *name);
+
+static int packref_cmp(const void *a_, const void *b_)
+{
+	const struct packref *a = a_, *b = b_;
+	return strcmp(a->name, b->name);
+}
+
+static int packed_reload(refdb_fs_backend *backend)
+{
+	int error;
+	git_buf packedrefs = GIT_BUF_INIT;
+	char *scan, *eof, *eol;
+
+	if (!backend->gitpath)
+		return 0;
+
+	error = git_sortedcache_lockandload(backend->refcache, &packedrefs);
+
+	/*
+	 * If we can't find the packed-refs, clear table and return.
+	 * Any other error just gets passed through.
+	 * If no error, and file wasn't changed, just return.
+	 * Anything else means we need to refresh the packed refs.
+	 */
+	if (error <= 0) {
+		if (error == GIT_ENOTFOUND) {
+			git_sortedcache_clear(backend->refcache, true);
+			giterr_clear();
+			error = 0;
+		}
+		return error;
+	}
+
+	/* At this point, refresh the packed refs from the loaded buffer. */
+
+	git_sortedcache_clear(backend->refcache, false);
+
+	scan = (char *)packedrefs.ptr;
+	eof  = scan + packedrefs.size;
+
+	backend->peeling_mode = PEELING_NONE;
+
+	if (*scan == '#') {
+		static const char *traits_header = "# pack-refs with: ";
+
+		if (git__prefixcmp(scan, traits_header) == 0) {
+			scan += strlen(traits_header);
+			eol = strchr(scan, '\n');
+
+			if (!eol)
+				goto parse_failed;
+			*eol = '\0';
+
+			if (strstr(scan, " fully-peeled ") != NULL) {
+				backend->peeling_mode = PEELING_FULL;
+			} else if (strstr(scan, " peeled ") != NULL) {
+				backend->peeling_mode = PEELING_STANDARD;
+			}
+
+			scan = eol + 1;
+		}
+	}
+
+	while (scan < eof && *scan == '#') {
+		if (!(eol = strchr(scan, '\n')))
+			goto parse_failed;
+		scan = eol + 1;
+	}
+
+	while (scan < eof) {
+		struct packref *ref;
+		git_oid oid;
+
+		/* parse "<OID> <refname>\n" */
+
+		if (git_oid_fromstr(&oid, scan) < 0)
+			goto parse_failed;
+		scan += GIT_OID_HEXSZ;
+
+		if (*scan++ != ' ')
+			goto parse_failed;
+		if (!(eol = strchr(scan, '\n')))
+			goto parse_failed;
+		*eol = '\0';
+		if (eol[-1] == '\r')
+			eol[-1] = '\0';
+
+		if (git_sortedcache_upsert((void **)&ref, backend->refcache, scan) < 0)
+			goto parse_failed;
+		scan = eol + 1;
+
+		git_oid_cpy(&ref->oid, &oid);
+
+		/* look for optional "^<OID>\n" */
+
+		if (*scan == '^') {
+			if (git_oid_fromstr(&oid, scan + 1) < 0)
+				goto parse_failed;
+			scan += GIT_OID_HEXSZ + 1;
+
+			if (scan < eof) {
+				if (!(eol = strchr(scan, '\n')))
+					goto parse_failed;
+				scan = eol + 1;
+			}
+
+			git_oid_cpy(&ref->peel, &oid);
+			ref->flags |= PACKREF_HAS_PEEL;
+		}
+		else if (backend->peeling_mode == PEELING_FULL ||
+				(backend->peeling_mode == PEELING_STANDARD &&
+				 git__prefixcmp(ref->name, GIT_REFS_TAGS_DIR) == 0))
+			ref->flags |= PACKREF_CANNOT_PEEL;
+	}
+
+	git_sortedcache_wunlock(backend->refcache);
+	git_buf_free(&packedrefs);
+
+	return 0;
+
+parse_failed:
+	giterr_set(GITERR_REFERENCE, "corrupted packed references file");
+
+	git_sortedcache_clear(backend->refcache, false);
+	git_sortedcache_wunlock(backend->refcache);
+	git_buf_free(&packedrefs);
+
+	return -1;
+}
+
+static int loose_parse_oid(
+	git_oid *oid, const char *filename, git_buf *file_content)
+{
+	const char *str = git_buf_cstr(file_content);
+
+	if (git_buf_len(file_content) < GIT_OID_HEXSZ)
+		goto corrupted;
+
+	/* we need to get 40 OID characters from the file */
+	if (git_oid_fromstr(oid, str) < 0)
+		goto corrupted;
+
+	/* If the file is longer than 40 chars, the 41st must be a space */
+	str += GIT_OID_HEXSZ;
+	if (*str == '\0' || git__isspace(*str))
+		return 0;
+
+corrupted:
+	giterr_set(GITERR_REFERENCE, "corrupted loose reference file: %s", filename);
+	return -1;
+}
+
+static int loose_readbuffer(git_buf *buf, const char *base, const char *path)
+{
+	int error;
+
+	/* build full path to file */
+	if ((error = git_buf_joinpath(buf, base, path)) < 0 ||
+		(error = git_futils_readbuffer(buf, buf->ptr)) < 0)
+		git_buf_free(buf);
+
+	return error;
+}
+
+static int loose_lookup_to_packfile(refdb_fs_backend *backend, const char *name)
+{
+	int error = 0;
+	git_buf ref_file = GIT_BUF_INIT;
+	struct packref *ref = NULL;
+	git_oid oid;
+
+	/* if we fail to load the loose reference, assume someone changed
+	 * the filesystem under us and skip it...
+	 */
+	if (loose_readbuffer(&ref_file, backend->gitpath, name) < 0) {
+		giterr_clear();
+		goto done;
+	}
+
+	/* skip symbolic refs */
+	if (!git__prefixcmp(git_buf_cstr(&ref_file), GIT_SYMREF))
+		goto done;
+
+	/* parse OID from file */
+	if ((error = loose_parse_oid(&oid, name, &ref_file)) < 0)
+		goto done;
+
+	git_sortedcache_wlock(backend->refcache);
+
+	if (!(error = git_sortedcache_upsert(
+			(void **)&ref, backend->refcache, name))) {
+
+		git_oid_cpy(&ref->oid, &oid);
+		ref->flags = PACKREF_WAS_LOOSE;
+	}
+
+	git_sortedcache_wunlock(backend->refcache);
+
+done:
+	git_buf_free(&ref_file);
+	return error;
+}
+
+static int _dirent_loose_load(void *payload, git_buf *full_path)
+{
+	refdb_fs_backend *backend = payload;
+	const char *file_path;
+
+	if (git__suffixcmp(full_path->ptr, ".lock") == 0)
+		return 0;
+
+	if (git_path_isdir(full_path->ptr)) {
+		int error = git_path_direach(
+			full_path, backend->direach_flags, _dirent_loose_load, backend);
+		/* Race with the filesystem, ignore it */
+		if (error == GIT_ENOTFOUND) {
+			giterr_clear();
+			return 0;
+		}
+
+		return error;
+	}
+
+	file_path = full_path->ptr + strlen(backend->gitpath);
+
+	return loose_lookup_to_packfile(backend, file_path);
+}
+
+/*
+ * Load all the loose references from the repository
+ * into the in-memory Packfile, and build a vector with
+ * all the references so it can be written back to
+ * disk.
+ */
+static int packed_loadloose(refdb_fs_backend *backend)
+{
+	int error;
+	git_buf refs_path = GIT_BUF_INIT;
+
+	if (git_buf_joinpath(&refs_path, backend->gitpath, GIT_REFS_DIR) < 0)
+		return -1;
+
+	/*
+	 * Load all the loose files from disk into the Packfile table.
+	 * This will overwrite any old packed entries with their
+	 * updated loose versions
+	 */
+	error = git_path_direach(
+		&refs_path, backend->direach_flags, _dirent_loose_load, backend);
+
+	git_buf_free(&refs_path);
+
+	return error;
+}
+
+static int refdb_fs_backend__exists(
+	int *exists,
+	git_refdb_backend *_backend,
+	const char *ref_name)
+{
+	refdb_fs_backend *backend = (refdb_fs_backend *)_backend;
+	git_buf ref_path = GIT_BUF_INIT;
+	int error;
+
+	assert(backend);
+
+	if ((error = packed_reload(backend)) < 0 ||
+		(error = git_buf_joinpath(&ref_path, backend->gitpath, ref_name)) < 0)
+		return error;
+
+	*exists = git_path_isfile(ref_path.ptr) ||
+		(git_sortedcache_lookup(backend->refcache, ref_name) != NULL);
+
+	git_buf_free(&ref_path);
+	return 0;
+}
+
+static const char *loose_parse_symbolic(git_buf *file_content)
+{
+	const unsigned int header_len = (unsigned int)strlen(GIT_SYMREF);
+	const char *refname_start;
+
+	refname_start = (const char *)file_content->ptr;
+
+	if (git_buf_len(file_content) < header_len + 1) {
+		giterr_set(GITERR_REFERENCE, "corrupted loose reference file");
+		return NULL;
+	}
+
+	/*
+	 * Assume we have already checked for the header
+	 * before calling this function
+	 */
+	refname_start += header_len;
+
+	return refname_start;
+}
+
+/*
+ * Returns whether a reference is stored per worktree or not.
+ * Per-worktree references are:
+ *
+ * - all pseudorefs, e.g. HEAD and MERGE_HEAD
+ * - all references stored inside of "refs/bisect/"
+ */
+static bool is_per_worktree_ref(const char *ref_name)
+{
+	return git__prefixcmp(ref_name, "refs/") != 0 ||
+	    git__prefixcmp(ref_name, "refs/bisect/") == 0;
+}
+
+static int loose_lookup(
+	git_reference **out,
+	refdb_fs_backend *backend,
+	const char *ref_name)
+{
+	git_buf ref_file = GIT_BUF_INIT;
+	int error = 0;
+	const char *ref_dir;
+
+	if (out)
+		*out = NULL;
+
+	if (is_per_worktree_ref(ref_name))
+		ref_dir = backend->gitpath;
+	else
+		ref_dir = backend->commonpath;
+
+	if ((error = loose_readbuffer(&ref_file, ref_dir, ref_name)) < 0)
+		/* cannot read loose ref file - gah */;
+	else if (git__prefixcmp(git_buf_cstr(&ref_file), GIT_SYMREF) == 0) {
+		const char *target;
+
+		git_buf_rtrim(&ref_file);
+
+		if (!(target = loose_parse_symbolic(&ref_file)))
+			error = -1;
+		else if (out != NULL)
+			*out = git_reference__alloc_symbolic(ref_name, target);
+	} else {
+		git_oid oid;
+
+		if (!(error = loose_parse_oid(&oid, ref_name, &ref_file)) &&
+			out != NULL)
+			*out = git_reference__alloc(ref_name, &oid, NULL);
+	}
+
+	git_buf_free(&ref_file);
+	return error;
+}
+
+static int ref_error_notfound(const char *name)
+{
+	giterr_set(GITERR_REFERENCE, "reference '%s' not found", name);
+	return GIT_ENOTFOUND;
+}
+
+static int packed_lookup(
+	git_reference **out,
+	refdb_fs_backend *backend,
+	const char *ref_name)
+{
+	int error = 0;
+	struct packref *entry;
+
+	if ((error = packed_reload(backend)) < 0)
+		return error;
+
+	if (git_sortedcache_rlock(backend->refcache) < 0)
+		return -1;
+
+	entry = git_sortedcache_lookup(backend->refcache, ref_name);
+	if (!entry) {
+		error = ref_error_notfound(ref_name);
+	} else {
+		*out = git_reference__alloc(ref_name, &entry->oid, &entry->peel);
+		if (!*out)
+			error = -1;
+	}
+
+	git_sortedcache_runlock(backend->refcache);
+
+	return error;
+}
+
+static int refdb_fs_backend__lookup(
+	git_reference **out,
+	git_refdb_backend *_backend,
+	const char *ref_name)
+{
+	refdb_fs_backend *backend = (refdb_fs_backend *)_backend;
+	int error;
+
+	assert(backend);
+
+	if (!(error = loose_lookup(out, backend, ref_name)))
+		return 0;
+
+	/* only try to lookup this reference on the packfile if it
+	 * wasn't found on the loose refs; not if there was a critical error */
+	if (error == GIT_ENOTFOUND) {
+		giterr_clear();
+		error = packed_lookup(out, backend, ref_name);
+	}
+
+	return error;
+}
+
+typedef struct {
+	git_reference_iterator parent;
+
+	char *glob;
+
+	git_pool pool;
+	git_vector loose;
+
+	git_sortedcache *cache;
+	size_t loose_pos;
+	size_t packed_pos;
+} refdb_fs_iter;
+
+static void refdb_fs_backend__iterator_free(git_reference_iterator *_iter)
+{
+	refdb_fs_iter *iter = (refdb_fs_iter *) _iter;
+
+	git_vector_free(&iter->loose);
+	git_pool_clear(&iter->pool);
+	git_sortedcache_free(iter->cache);
+	git__free(iter);
+}
+
+static int iter_load_loose_paths(refdb_fs_backend *backend, refdb_fs_iter *iter)
+{
+	int error = 0;
+	git_buf path = GIT_BUF_INIT;
+	git_iterator *fsit = NULL;
+	git_iterator_options fsit_opts = GIT_ITERATOR_OPTIONS_INIT;
+	const git_index_entry *entry = NULL;
+	const char *ref_prefix = GIT_REFS_DIR;
+	size_t ref_prefix_len = strlen(ref_prefix);
+
+	if (!backend->commonpath) /* do nothing if no commonpath for loose refs */
+		return 0;
+
+	fsit_opts.flags = backend->iterator_flags;
+
+	if (iter->glob) {
+		const char *last_sep = NULL;
+		const char *pos;
+		for (pos = iter->glob; *pos; ++pos) {
+			switch (*pos) {
+			case '?':
+			case '*':
+			case '[':
+			case '\\':
+				break;
+			case '/':
+				last_sep = pos;
+				/* FALLTHROUGH */
+			default:
+				continue;
+			}
+			break;
+		}
+		if (last_sep) {
+			ref_prefix = iter->glob;
+			ref_prefix_len = (last_sep - ref_prefix) + 1;
+		}
+	}
+
+	if ((error = git_buf_printf(&path, "%s/", backend->commonpath)) < 0 ||
+		(error = git_buf_put(&path, ref_prefix, ref_prefix_len)) < 0 ||
+		(error = git_iterator_for_filesystem(&fsit, path.ptr, &fsit_opts)) < 0) {
+		git_buf_free(&path);
+		return error;
+	}
+
+	error = git_buf_sets(&path, ref_prefix);
+
+	while (!error && !git_iterator_advance(&entry, fsit)) {
+		const char *ref_name;
+		struct packref *ref;
+		char *ref_dup;
+
+		git_buf_truncate(&path, ref_prefix_len);
+		git_buf_puts(&path, entry->path);
+		ref_name = git_buf_cstr(&path);
+
+		if (git__suffixcmp(ref_name, ".lock") == 0 ||
+			(iter->glob && p_fnmatch(iter->glob, ref_name, 0) != 0))
+			continue;
+
+		git_sortedcache_rlock(backend->refcache);
+		ref = git_sortedcache_lookup(backend->refcache, ref_name);
+		if (ref)
+			ref->flags |= PACKREF_SHADOWED;
+		git_sortedcache_runlock(backend->refcache);
+
+		ref_dup = git_pool_strdup(&iter->pool, ref_name);
+		if (!ref_dup)
+			error = -1;
+		else
+			error = git_vector_insert(&iter->loose, ref_dup);
+	}
+
+	git_iterator_free(fsit);
+	git_buf_free(&path);
+
+	return error;
+}
+
+static int refdb_fs_backend__iterator_next(
+	git_reference **out, git_reference_iterator *_iter)
+{
+	int error = GIT_ITEROVER;
+	refdb_fs_iter *iter = (refdb_fs_iter *)_iter;
+	refdb_fs_backend *backend = (refdb_fs_backend *)iter->parent.db->backend;
+	struct packref *ref;
+
+	while (iter->loose_pos < iter->loose.length) {
+		const char *path = git_vector_get(&iter->loose, iter->loose_pos++);
+
+		if (loose_lookup(out, backend, path) == 0)
+			return 0;
+
+		giterr_clear();
+	}
+
+	if (!iter->cache) {
+		if ((error = git_sortedcache_copy(&iter->cache, backend->refcache, 1, NULL, NULL)) < 0)
+			return error;
+	}
+
+	error = GIT_ITEROVER;
+	while (iter->packed_pos < git_sortedcache_entrycount(iter->cache)) {
+		ref = git_sortedcache_entry(iter->cache, iter->packed_pos++);
+		if (!ref) /* stop now if another thread deleted refs and we past end */
+			break;
+
+		if (ref->flags & PACKREF_SHADOWED)
+			continue;
+		if (iter->glob && p_fnmatch(iter->glob, ref->name, 0) != 0)
+			continue;
+
+		*out = git_reference__alloc(ref->name, &ref->oid, &ref->peel);
+		error = (*out != NULL) ? 0 : -1;
+		break;
+	}
+
+	return error;
+}
+
+static int refdb_fs_backend__iterator_next_name(
+	const char **out, git_reference_iterator *_iter)
+{
+	int error = GIT_ITEROVER;
+	refdb_fs_iter *iter = (refdb_fs_iter *)_iter;
+	refdb_fs_backend *backend = (refdb_fs_backend *)iter->parent.db->backend;
+	struct packref *ref;
+
+	while (iter->loose_pos < iter->loose.length) {
+		const char *path = git_vector_get(&iter->loose, iter->loose_pos++);
+
+		if (loose_lookup(NULL, backend, path) == 0) {
+			*out = path;
+			return 0;
+		}
+
+		giterr_clear();
+	}
+
+	if (!iter->cache) {
+		if ((error = git_sortedcache_copy(&iter->cache, backend->refcache, 1, NULL, NULL)) < 0)
+			return error;
+	}
+
+	error = GIT_ITEROVER;
+	while (iter->packed_pos < git_sortedcache_entrycount(iter->cache)) {
+		ref = git_sortedcache_entry(iter->cache, iter->packed_pos++);
+		if (!ref) /* stop now if another thread deleted refs and we past end */
+			break;
+
+		if (ref->flags & PACKREF_SHADOWED)
+			continue;
+		if (iter->glob && p_fnmatch(iter->glob, ref->name, 0) != 0)
+			continue;
+
+		*out = ref->name;
+		error = 0;
+		break;
+	}
+
+	return error;
+}
+
+static int refdb_fs_backend__iterator(
+	git_reference_iterator **out, git_refdb_backend *_backend, const char *glob)
+{
+	int error;
+	refdb_fs_iter *iter;
+	refdb_fs_backend *backend = (refdb_fs_backend *)_backend;
+
+	assert(backend);
+
+	if ((error = packed_reload(backend)) < 0)
+		return error;
+
+	iter = git__calloc(1, sizeof(refdb_fs_iter));
+	GITERR_CHECK_ALLOC(iter);
+
+	git_pool_init(&iter->pool, 1);
+
+	if (git_vector_init(&iter->loose, 8, NULL) < 0)
+		goto fail;
+
+	if (glob != NULL &&
+		(iter->glob = git_pool_strdup(&iter->pool, glob)) == NULL)
+		goto fail;
+
+	iter->parent.next = refdb_fs_backend__iterator_next;
+	iter->parent.next_name = refdb_fs_backend__iterator_next_name;
+	iter->parent.free = refdb_fs_backend__iterator_free;
+
+	if (iter_load_loose_paths(backend, iter) < 0)
+		goto fail;
+
+	*out = (git_reference_iterator *)iter;
+	return 0;
+
+fail:
+	refdb_fs_backend__iterator_free((git_reference_iterator *)iter);
+	return -1;
+}
+
+static bool ref_is_available(
+	const char *old_ref, const char *new_ref, const char *this_ref)
+{
+	if (old_ref == NULL || strcmp(old_ref, this_ref)) {
+		size_t reflen = strlen(this_ref);
+		size_t newlen = strlen(new_ref);
+		size_t cmplen = reflen < newlen ? reflen : newlen;
+		const char *lead = reflen < newlen ? new_ref : this_ref;
+
+		if (!strncmp(new_ref, this_ref, cmplen) && lead[cmplen] == '/') {
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static int reference_path_available(
+	refdb_fs_backend *backend,
+	const char *new_ref,
+	const char* old_ref,
+	int force)
+{
+	size_t i;
+	int error;
+
+	if ((error = packed_reload(backend)) < 0)
+		return error;
+
+	if (!force) {
+		int exists;
+
+		if ((error = refdb_fs_backend__exists(
+			&exists, (git_refdb_backend *)backend, new_ref)) < 0) {
+			return error;
+		}
+
+		if (exists) {
+			giterr_set(GITERR_REFERENCE,
+				"failed to write reference '%s': a reference with "
+				"that name already exists.", new_ref);
+			return GIT_EEXISTS;
+		}
+	}
+
+	git_sortedcache_rlock(backend->refcache);
+
+	for (i = 0; i < git_sortedcache_entrycount(backend->refcache); ++i) {
+		struct packref *ref = git_sortedcache_entry(backend->refcache, i);
+
+		if (ref && !ref_is_available(old_ref, new_ref, ref->name)) {
+			git_sortedcache_runlock(backend->refcache);
+			giterr_set(GITERR_REFERENCE,
+				"path to reference '%s' collides with existing one", new_ref);
+			return -1;
+		}
+	}
+
+	git_sortedcache_runlock(backend->refcache);
+	return 0;
+}
+
+static int loose_lock(git_filebuf *file, refdb_fs_backend *backend, const char *name)
+{
+	int error, filebuf_flags;
+	git_buf ref_path = GIT_BUF_INIT;
+	const char *basedir;
+
+	assert(file && backend && name);
+
+	if (!git_path_isvalid(backend->repo, name, 0, GIT_PATH_REJECT_FILESYSTEM_DEFAULTS)) {
+		giterr_set(GITERR_INVALID, "invalid reference name '%s'", name);
+		return GIT_EINVALIDSPEC;
+	}
+
+	if (is_per_worktree_ref(name))
+		basedir = backend->gitpath;
+	else
+		basedir = backend->commonpath;
+
+	/* Remove a possibly existing empty directory hierarchy
+	 * which name would collide with the reference name
+	 */
+	if ((error = git_futils_rmdir_r(name, basedir, GIT_RMDIR_SKIP_NONEMPTY)) < 0)
+		return error;
+
+	if (git_buf_joinpath(&ref_path, basedir, name) < 0)
+		return -1;
+
+	filebuf_flags = GIT_FILEBUF_FORCE;
+	if (backend->fsync)
+		filebuf_flags |= GIT_FILEBUF_FSYNC;
+
+	error = git_filebuf_open(file, ref_path.ptr, filebuf_flags, GIT_REFS_FILE_MODE);
+
+	if (error == GIT_EDIRECTORY)
+		giterr_set(GITERR_REFERENCE, "cannot lock ref '%s', there are refs beneath that folder", name);
+
+	git_buf_free(&ref_path);
+	return error;
+}
+
+static int loose_commit(git_filebuf *file, const git_reference *ref)
+{
+	assert(file && ref);
+
+	if (ref->type == GIT_REF_OID) {
+		char oid[GIT_OID_HEXSZ + 1];
+		git_oid_nfmt(oid, sizeof(oid), &ref->target.oid);
+
+		git_filebuf_printf(file, "%s\n", oid);
+	} else if (ref->type == GIT_REF_SYMBOLIC) {
+		git_filebuf_printf(file, GIT_SYMREF "%s\n", ref->target.symbolic);
+	} else {
+		assert(0); /* don't let this happen */
+	}
+
+	return git_filebuf_commit(file);
+}
+
+static int refdb_fs_backend__lock(void **out, git_refdb_backend *_backend, const char *refname)
+{
+	int error;
+	git_filebuf *lock;
+	refdb_fs_backend *backend = (refdb_fs_backend *) _backend;
+
+	lock = git__calloc(1, sizeof(git_filebuf));
+	GITERR_CHECK_ALLOC(lock);
+
+	if ((error = loose_lock(lock, backend, refname)) < 0) {
+		git__free(lock);
+		return error;
+	}
+
+	*out = lock;
+	return 0;
+}
+
+static int refdb_fs_backend__write_tail(
+	git_refdb_backend *_backend,
+	const git_reference *ref,
+	git_filebuf *file,
+	int update_reflog,
+	const git_signature *who,
+	const char *message,
+	const git_oid *old_id,
+	const char *old_target);
+
+static int refdb_fs_backend__delete_tail(
+	git_refdb_backend *_backend,
+	git_filebuf *file,
+	const char *ref_name,
+	const git_oid *old_id, const char *old_target);
+
+static int refdb_fs_backend__unlock(git_refdb_backend *backend, void *payload, int success, int update_reflog,
+				    const git_reference *ref, const git_signature *sig, const char *message)
+{
+	git_filebuf *lock = (git_filebuf *) payload;
+	int error = 0;
+
+	if (success == 2)
+		error = refdb_fs_backend__delete_tail(backend, lock, ref->name, NULL, NULL);
+	else if (success)
+		error = refdb_fs_backend__write_tail(backend, ref, lock, update_reflog, sig, message, NULL, NULL);
+	else
+		git_filebuf_cleanup(lock);
+
+	git__free(lock);
+	return error;
+}
+
+/*
+ * Find out what object this reference resolves to.
+ *
+ * For references that point to a 'big' tag (e.g. an
+ * actual tag object on the repository), we need to
+ * cache on the packfile the OID of the object to
+ * which that 'big tag' is pointing to.
+ */
+static int packed_find_peel(refdb_fs_backend *backend, struct packref *ref)
+{
+	git_object *object;
+
+	if (ref->flags & PACKREF_HAS_PEEL || ref->flags & PACKREF_CANNOT_PEEL)
+		return 0;
+
+	/*
+	 * Find the tagged object in the repository
+	 */
+	if (git_object_lookup(&object, backend->repo, &ref->oid, GIT_OBJ_ANY) < 0)
+		return -1;
+
+	/*
+	 * If the tagged object is a Tag object, we need to resolve it;
+	 * if the ref is actually a 'weak' ref, we don't need to resolve
+	 * anything.
+	 */
+	if (git_object_type(object) == GIT_OBJ_TAG) {
+		git_tag *tag = (git_tag *)object;
+
+		/*
+		 * Find the object pointed at by this tag
+		 */
+		git_oid_cpy(&ref->peel, git_tag_target_id(tag));
+		ref->flags |= PACKREF_HAS_PEEL;
+
+		/*
+		 * The reference has now cached the resolved OID, and is
+		 * marked at such. When written to the packfile, it'll be
+		 * accompanied by this resolved oid
+		 */
+	}
+
+	git_object_free(object);
+	return 0;
+}
+
+/*
+ * Write a single reference into a packfile
+ */
+static int packed_write_ref(struct packref *ref, git_filebuf *file)
+{
+	char oid[GIT_OID_HEXSZ + 1];
+	git_oid_nfmt(oid, sizeof(oid), &ref->oid);
+
+	/*
+	 * For references that peel to an object in the repo, we must
+	 * write the resulting peel on a separate line, e.g.
+	 *
+	 *	6fa8a902cc1d18527e1355773c86721945475d37 refs/tags/libgit2-0.4
+	 *	^2ec0cb7959b0bf965d54f95453f5b4b34e8d3100
+	 *
+	 * This obviously only applies to tags.
+	 * The required peels have already been loaded into `ref->peel_target`.
+	 */
+	if (ref->flags & PACKREF_HAS_PEEL) {
+		char peel[GIT_OID_HEXSZ + 1];
+		git_oid_nfmt(peel, sizeof(peel), &ref->peel);
+
+		if (git_filebuf_printf(file, "%s %s\n^%s\n", oid, ref->name, peel) < 0)
+			return -1;
+	} else {
+		if (git_filebuf_printf(file, "%s %s\n", oid, ref->name) < 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+/*
+ * Remove all loose references
+ *
+ * Once we have successfully written a packfile,
+ * all the loose references that were packed must be
+ * removed from disk.
+ *
+ * This is a dangerous method; make sure the packfile
+ * is well-written, because we are destructing references
+ * here otherwise.
+ */
+static int packed_remove_loose(refdb_fs_backend *backend)
+{
+	size_t i;
+	git_filebuf lock = GIT_FILEBUF_INIT;
+	git_buf ref_content = GIT_BUF_INIT;
+	int error = 0;
+
+	/* backend->refcache is already locked when this is called */
+
+	for (i = 0; i < git_sortedcache_entrycount(backend->refcache); ++i) {
+		struct packref *ref = git_sortedcache_entry(backend->refcache, i);
+		git_oid current_id;
+
+		if (!ref || !(ref->flags & PACKREF_WAS_LOOSE))
+			continue;
+
+		git_filebuf_cleanup(&lock);
+
+		/* We need to stop anybody from updating the ref while we try to do a safe delete */
+		error = loose_lock(&lock, backend, ref->name);
+		/* If someone else is updating it, let them do it */
+		if (error == GIT_EEXISTS || error == GIT_ENOTFOUND)
+			continue;
+
+		if (error < 0) {
+			git_buf_free(&ref_content);
+			giterr_set(GITERR_REFERENCE, "failed to lock loose reference '%s'", ref->name);
+			return error;
+		}
+
+		error = git_futils_readbuffer(&ref_content, lock.path_original);
+		/* Someone else beat us to cleaning up the ref, let's simply continue */
+		if (error == GIT_ENOTFOUND)
+			continue;
+
+		/* This became a symref between us packing and trying to delete it, so ignore it */
+		if (!git__prefixcmp(ref_content.ptr, GIT_SYMREF))
+			continue;
+
+		/* Figure out the current id; if we find a bad ref file, skip it so we can do the rest */
+		if (loose_parse_oid(&current_id, lock.path_original, &ref_content) < 0)
+			continue;
+
+		/* If the ref moved since we packed it, we must not delete it */
+		if (!git_oid_equal(&current_id, &ref->oid))
+			continue;
+
+		/*
+		 * if we fail to remove a single file, this is *not* good,
+		 * but we should keep going and remove as many as possible.
+		 * If we fail to remove, the ref is still in the old state, so
+		 * we haven't lost information.
+		 */
+		p_unlink(lock.path_original);
+	}
+
+	git_buf_free(&ref_content);
+	git_filebuf_cleanup(&lock);
+	return 0;
+}
+
+/*
+ * Write all the contents in the in-memory packfile to disk.
+ */
+static int packed_write(refdb_fs_backend *backend)
+{
+	git_sortedcache *refcache = backend->refcache;
+	git_filebuf pack_file = GIT_FILEBUF_INIT;
+	int error, open_flags = 0;
+	size_t i;
+
+	/* lock the cache to updates while we do this */
+	if ((error = git_sortedcache_wlock(refcache)) < 0)
+		return error;
+
+	if (backend->fsync)
+		open_flags = GIT_FILEBUF_FSYNC;
+
+	/* Open the file! */
+	if ((error = git_filebuf_open(&pack_file, git_sortedcache_path(refcache), open_flags, GIT_PACKEDREFS_FILE_MODE)) < 0)
+		goto fail;
+
+	/* Packfiles have a header... apparently
+	 * This is in fact not required, but we might as well print it
+	 * just for kicks */
+	if ((error = git_filebuf_printf(&pack_file, "%s\n", GIT_PACKEDREFS_HEADER)) < 0)
+		goto fail;
+
+	for (i = 0; i < git_sortedcache_entrycount(refcache); ++i) {
+		struct packref *ref = git_sortedcache_entry(refcache, i);
+		assert(ref);
+
+		if ((error = packed_find_peel(backend, ref)) < 0)
+			goto fail;
+
+		if ((error = packed_write_ref(ref, &pack_file)) < 0)
+			goto fail;
+	}
+
+	/* if we've written all the references properly, we can commit
+	 * the packfile to make the changes effective */
+	if ((error = git_filebuf_commit(&pack_file)) < 0)
+		goto fail;
+
+	/* when and only when the packfile has been properly written,
+	 * we can go ahead and remove the loose refs */
+	if ((error = packed_remove_loose(backend)) < 0)
+		goto fail;
+
+	git_sortedcache_updated(refcache);
+	git_sortedcache_wunlock(refcache);
+
+	/* we're good now */
+	return 0;
+
+fail:
+	git_filebuf_cleanup(&pack_file);
+	git_sortedcache_wunlock(refcache);
+
+	return error;
+}
+
+static int reflog_append(refdb_fs_backend *backend, const git_reference *ref, const git_oid *old, const git_oid *new, const git_signature *author, const char *message);
+static int has_reflog(git_repository *repo, const char *name);
+
+/* We only write if it's under heads/, remotes/ or notes/ or if it already has a log */
+static int should_write_reflog(int *write, git_repository *repo, const char *name)
+{
+	int error, logall;
+
+	error = git_repository__cvar(&logall, repo, GIT_CVAR_LOGALLREFUPDATES);
+	if (error < 0)
+		return error;
+
+	/* Defaults to the opposite of the repo being bare */
+	if (logall == GIT_LOGALLREFUPDATES_UNSET)
+		logall = !git_repository_is_bare(repo);
+
+	if (!logall) {
+		*write = 0;
+	} else if (has_reflog(repo, name)) {
+		*write = 1;
+	} else if (!git__prefixcmp(name, GIT_REFS_HEADS_DIR) ||
+		   !git__strcmp(name, GIT_HEAD_FILE) ||
+		   !git__prefixcmp(name, GIT_REFS_REMOTES_DIR) ||
+		   !git__prefixcmp(name, GIT_REFS_NOTES_DIR)) {
+		*write = 1;
+	} else {
+		*write = 0;
+	}
+
+	return 0;
+}
+
+static int cmp_old_ref(int *cmp, git_refdb_backend *backend, const char *name,
+	const git_oid *old_id, const char *old_target)
+{
+	int error = 0;
+	git_reference *old_ref = NULL;
+
+	*cmp = 0;
+	/* It "matches" if there is no old value to compare against */
+	if (!old_id && !old_target)
+		return 0;
+
+	if ((error = refdb_fs_backend__lookup(&old_ref, backend, name)) < 0)
+		goto out;
+
+	/* If the types don't match, there's no way the values do */
+	if (old_id && old_ref->type != GIT_REF_OID) {
+		*cmp = -1;
+		goto out;
+	}
+	if (old_target && old_ref->type != GIT_REF_SYMBOLIC) {
+		*cmp = 1;
+		goto out;
+	}
+
+	if (old_id && old_ref->type == GIT_REF_OID)
+		*cmp = git_oid_cmp(old_id, &old_ref->target.oid);
+
+	if (old_target && old_ref->type == GIT_REF_SYMBOLIC)
+		*cmp = git__strcmp(old_target, old_ref->target.symbolic);
+
+out:
+	git_reference_free(old_ref);
+
+	return error;
+}
+
+/*
+ * The git.git comment regarding this, for your viewing pleasure:
+ *
+ * Special hack: If a branch is updated directly and HEAD
+ * points to it (may happen on the remote side of a push
+ * for example) then logically the HEAD reflog should be
+ * updated too.
+ * A generic solution implies reverse symref information,
+ * but finding all symrefs pointing to the given branch
+ * would be rather costly for this rare event (the direct
+ * update of a branch) to be worth it.  So let's cheat and
+ * check with HEAD only which should cover 99% of all usage
+ * scenarios (even 100% of the default ones).
+ */
+static int maybe_append_head(refdb_fs_backend *backend, const git_reference *ref, const git_signature *who, const char *message)
+{
+	int error;
+	git_oid old_id;
+	git_reference *tmp = NULL, *head = NULL, *peeled = NULL;
+	const char *name;
+
+	if (ref->type == GIT_REF_SYMBOLIC)
+		return 0;
+
+	/* if we can't resolve, we use {0}*40 as old id */
+	if (git_reference_name_to_id(&old_id, backend->repo, ref->name) < 0)
+		memset(&old_id, 0, sizeof(old_id));
+
+	if ((error = git_reference_lookup(&head, backend->repo, GIT_HEAD_FILE)) < 0)
+		return error;
+
+	if (git_reference_type(head) == GIT_REF_OID)
+		goto cleanup;
+
+	if ((error = git_reference_lookup(&tmp, backend->repo, GIT_HEAD_FILE)) < 0)
+		goto cleanup;
+
+	/* Go down the symref chain until we find the branch */
+	while (git_reference_type(tmp) == GIT_REF_SYMBOLIC) {
+		error = git_reference_lookup(&peeled, backend->repo, git_reference_symbolic_target(tmp));
+		if (error < 0)
+			break;
+
+		git_reference_free(tmp);
+		tmp = peeled;
+	}
+
+	if (error == GIT_ENOTFOUND) {
+		error = 0;
+		name = git_reference_symbolic_target(tmp);
+	} else if (error < 0) {
+		goto cleanup;
+	} else {
+		name = git_reference_name(tmp);
+	}
+
+	if (strcmp(name, ref->name))
+		goto cleanup;
+
+	error = reflog_append(backend, head, &old_id, git_reference_target(ref), who, message);
+
+cleanup:
+	git_reference_free(tmp);
+	git_reference_free(head);
+	return error;
+}
+
+static int refdb_fs_backend__write(
+	git_refdb_backend *_backend,
+	const git_reference *ref,
+	int force,
+	const git_signature *who,
+	const char *message,
+	const git_oid *old_id,
+	const char *old_target)
+{
+	refdb_fs_backend *backend = (refdb_fs_backend *)_backend;
+	git_filebuf file = GIT_FILEBUF_INIT;
+	int error = 0;
+
+	assert(backend);
+
+	if ((error = reference_path_available(backend, ref->name, NULL, force)) < 0)
+		return error;
+
+	/* We need to perform the reflog append and old value check under the ref's lock */
+	if ((error = loose_lock(&file, backend, ref->name)) < 0)
+		return error;
+
+	return refdb_fs_backend__write_tail(_backend, ref, &file, true, who, message, old_id, old_target);
+}
+
+static int refdb_fs_backend__write_tail(
+	git_refdb_backend *_backend,
+	const git_reference *ref,
+	git_filebuf *file,
+	int update_reflog,
+	const git_signature *who,
+	const char *message,
+	const git_oid *old_id,
+	const char *old_target)
+{
+	refdb_fs_backend *backend = (refdb_fs_backend *)_backend;
+	int error = 0, cmp = 0, should_write;
+	const char *new_target = NULL;
+	const git_oid *new_id = NULL;
+
+	if ((error = cmp_old_ref(&cmp, _backend, ref->name, old_id, old_target)) < 0)
+		goto on_error;
+
+	if (cmp) {
+		giterr_set(GITERR_REFERENCE, "old reference value does not match");
+		error = GIT_EMODIFIED;
+		goto on_error;
+	}
+
+	if (ref->type == GIT_REF_SYMBOLIC)
+		new_target = ref->target.symbolic;
+	else
+		new_id = &ref->target.oid;
+
+	error = cmp_old_ref(&cmp, _backend, ref->name, new_id, new_target);
+	if (error < 0 && error != GIT_ENOTFOUND)
+		goto on_error;
+
+	/* Don't update if we have the same value */
+	if (!error && !cmp) {
+		error = 0;
+		goto on_error; /* not really error */
+	}
+
+	if (update_reflog) {
+		if ((error = should_write_reflog(&should_write, backend->repo, ref->name)) < 0)
+			goto on_error;
+
+		if (should_write) {
+			if ((error = reflog_append(backend, ref, NULL, NULL, who, message)) < 0)
+				goto on_error;
+			if ((error = maybe_append_head(backend, ref, who, message)) < 0)
+				goto on_error;
+		}
+	}
+
+	return loose_commit(file, ref);
+
+on_error:
+        git_filebuf_cleanup(file);
+        return error;
+}
+
+static int refdb_fs_backend__delete(
+	git_refdb_backend *_backend,
+	const char *ref_name,
+	const git_oid *old_id, const char *old_target)
+{
+	refdb_fs_backend *backend = (refdb_fs_backend *)_backend;
+	git_filebuf file = GIT_FILEBUF_INIT;
+	int error = 0;
+
+	assert(backend && ref_name);
+
+	if ((error = loose_lock(&file, backend, ref_name)) < 0)
+		return error;
+
+	if ((error = refdb_reflog_fs__delete(_backend, ref_name)) < 0) {
+		git_filebuf_cleanup(&file);
+		return error;
+	}
+
+	return refdb_fs_backend__delete_tail(_backend, &file, ref_name, old_id, old_target);
+}
+
+static int refdb_fs_backend__delete_tail(
+	git_refdb_backend *_backend,
+	git_filebuf *file,
+	const char *ref_name,
+	const git_oid *old_id, const char *old_target)
+{
+	refdb_fs_backend *backend = (refdb_fs_backend *)_backend;
+	git_buf loose_path = GIT_BUF_INIT;
+	size_t pack_pos;
+	int error = 0, cmp = 0;
+	bool loose_deleted = 0;
+
+	error = cmp_old_ref(&cmp, _backend, ref_name, old_id, old_target);
+	if (error < 0)
+		goto cleanup;
+
+	if (cmp) {
+		giterr_set(GITERR_REFERENCE, "old reference value does not match");
+		error = GIT_EMODIFIED;
+		goto cleanup;
+	}
+
+	/* If a loose reference exists, remove it from the filesystem */
+	if (git_buf_joinpath(&loose_path, backend->commonpath, ref_name) < 0)
+		return -1;
+
+
+	error = p_unlink(loose_path.ptr);
+	if (error < 0 && errno == ENOENT)
+		error = 0;
+	else if (error < 0)
+		goto cleanup;
+	else if (error == 0)
+		loose_deleted = 1;
+
+	if ((error = packed_reload(backend)) < 0)
+		goto cleanup;
+
+	/* If a packed reference exists, remove it from the packfile and repack */
+	if ((error = git_sortedcache_wlock(backend->refcache)) < 0)
+		goto cleanup;
+
+	if (!(error = git_sortedcache_lookup_index(
+			&pack_pos, backend->refcache, ref_name)))
+		error = git_sortedcache_remove(backend->refcache, pack_pos);
+
+	git_sortedcache_wunlock(backend->refcache);
+
+	if (error == GIT_ENOTFOUND) {
+		error = loose_deleted ? 0 : ref_error_notfound(ref_name);
+		goto cleanup;
+	}
+
+	error = packed_write(backend);
+
+cleanup:
+	git_buf_free(&loose_path);
+	git_filebuf_cleanup(file);
+
+	return error;
+}
+
+static int refdb_reflog_fs__rename(git_refdb_backend *_backend, const char *old_name, const char *new_name);
+
+static int refdb_fs_backend__rename(
+	git_reference **out,
+	git_refdb_backend *_backend,
+	const char *old_name,
+	const char *new_name,
+	int force,
+	const git_signature *who,
+	const char *message)
+{
+	refdb_fs_backend *backend = (refdb_fs_backend *)_backend;
+	git_reference *old, *new;
+	git_filebuf file = GIT_FILEBUF_INIT;
+	int error;
+
+	assert(backend);
+
+	if ((error = reference_path_available(
+			backend, new_name, old_name, force)) < 0 ||
+		(error = refdb_fs_backend__lookup(&old, _backend, old_name)) < 0)
+		return error;
+
+	if ((error = refdb_fs_backend__delete(_backend, old_name, NULL, NULL)) < 0) {
+		git_reference_free(old);
+		return error;
+	}
+
+	new = git_reference__set_name(old, new_name);
+	if (!new) {
+		git_reference_free(old);
+		return -1;
+	}
+
+	if ((error = loose_lock(&file, backend, new->name)) < 0) {
+		git_reference_free(new);
+		return error;
+	}
+
+	/* Try to rename the refog; it's ok if the old doesn't exist */
+	error = refdb_reflog_fs__rename(_backend, old_name, new_name);
+	if (((error == 0) || (error == GIT_ENOTFOUND)) &&
+	    ((error = reflog_append(backend, new, git_reference_target(new), NULL, who, message)) < 0)) {
+		git_reference_free(new);
+		git_filebuf_cleanup(&file);
+		return error;
+	}
+
+	if (error < 0) {
+		git_reference_free(new);
+		git_filebuf_cleanup(&file);
+		return error;
+	}
+
+
+	if ((error = loose_commit(&file, new)) < 0 || out == NULL) {
+		git_reference_free(new);
+		return error;
+	}
+
+	*out = new;
+	return 0;
+}
+
+static int refdb_fs_backend__compress(git_refdb_backend *_backend)
+{
+	int error;
+	refdb_fs_backend *backend = (refdb_fs_backend *)_backend;
+
+	assert(backend);
+
+	if ((error = packed_reload(backend)) < 0 || /* load the existing packfile */
+	    (error = packed_loadloose(backend)) < 0 || /* add all the loose refs */
+	    (error = packed_write(backend)) < 0) /* write back to disk */
+		return error;
+
+	return 0;
+}
+
+static void refdb_fs_backend__free(git_refdb_backend *_backend)
+{
+	refdb_fs_backend *backend = (refdb_fs_backend *)_backend;
+
+	assert(backend);
+
+	git_sortedcache_free(backend->refcache);
+	git__free(backend->gitpath);
+	git__free(backend->commonpath);
+	git__free(backend);
+}
+
+static char *setup_namespace(git_repository *repo, const char *in)
+{
+	git_buf path = GIT_BUF_INIT;
+	char *parts, *start, *end, *out = NULL;
+
+	if (!in)
+		goto done;
+
+	git_buf_puts(&path, in);
+
+	/* if the repo is not namespaced, nothing else to do */
+	if (repo->namespace == NULL) {
+		out = git_buf_detach(&path);
+		goto done;
+	}
+
+	parts = end = git__strdup(repo->namespace);
+	if (parts == NULL)
+		goto done;
+
+	/*
+	 * From `man gitnamespaces`:
+	 *  namespaces which include a / will expand to a hierarchy
+	 *  of namespaces; for example, GIT_NAMESPACE=foo/bar will store
+	 *  refs under refs/namespaces/foo/refs/namespaces/bar/
+	 */
+	while ((start = git__strsep(&end, "/")) != NULL)
+		git_buf_printf(&path, "refs/namespaces/%s/", start);
+
+	git_buf_printf(&path, "refs/namespaces/%s/refs", end);
+	git__free(parts);
+
+	/* Make sure that the folder with the namespace exists */
+	if (git_futils_mkdir_relative(git_buf_cstr(&path), in, 0777,
+			GIT_MKDIR_PATH, NULL) < 0)
+		goto done;
+
+	/* Return root of the namespaced gitpath, i.e. without the trailing '/refs' */
+	git_buf_rtruncate_at_char(&path, '/');
+	out = git_buf_detach(&path);
+
+done:
+	git_buf_free(&path);
+	return out;
+}
+
+static int reflog_alloc(git_reflog **reflog, const char *name)
+{
+	git_reflog *log;
+
+	*reflog = NULL;
+
+	log = git__calloc(1, sizeof(git_reflog));
+	GITERR_CHECK_ALLOC(log);
+
+	log->ref_name = git__strdup(name);
+	GITERR_CHECK_ALLOC(log->ref_name);
+
+	if (git_vector_init(&log->entries, 0, NULL) < 0) {
+		git__free(log->ref_name);
+		git__free(log);
+		return -1;
+	}
+
+	*reflog = log;
+
+	return 0;
+}
+
+static int reflog_parse(git_reflog *log, const char *buf, size_t buf_size)
+{
+	const char *ptr;
+	git_reflog_entry *entry;
+
+#define seek_forward(_increase) do { \
+	if (_increase >= buf_size) { \
+		giterr_set(GITERR_INVALID, "ran out of data while parsing reflog"); \
+		goto fail; \
+	} \
+	buf += _increase; \
+	buf_size -= _increase; \
+	} while (0)
+
+	while (buf_size > GIT_REFLOG_SIZE_MIN) {
+		entry = git__calloc(1, sizeof(git_reflog_entry));
+		GITERR_CHECK_ALLOC(entry);
+
+		entry->committer = git__calloc(1, sizeof(git_signature));
+		GITERR_CHECK_ALLOC(entry->committer);
+
+		if (git_oid_fromstrn(&entry->oid_old, buf, GIT_OID_HEXSZ) < 0)
+			goto fail;
+		seek_forward(GIT_OID_HEXSZ + 1);
+
+		if (git_oid_fromstrn(&entry->oid_cur, buf, GIT_OID_HEXSZ) < 0)
+			goto fail;
+		seek_forward(GIT_OID_HEXSZ + 1);
+
+		ptr = buf;
+
+		/* Seek forward to the end of the signature. */
+		while (*buf && *buf != '\t' && *buf != '\n')
+			seek_forward(1);
+
+		if (git_signature__parse(entry->committer, &ptr, buf + 1, NULL, *buf) < 0)
+			goto fail;
+
+		if (*buf == '\t') {
+			/* We got a message. Read everything till we reach LF. */
+			seek_forward(1);
+			ptr = buf;
+
+			while (*buf && *buf != '\n')
+				seek_forward(1);
+
+			entry->msg = git__strndup(ptr, buf - ptr);
+			GITERR_CHECK_ALLOC(entry->msg);
+		} else
+			entry->msg = NULL;
+
+		while (*buf && *buf == '\n' && buf_size > 1)
+			seek_forward(1);
+
+		if (git_vector_insert(&log->entries, entry) < 0)
+			goto fail;
+	}
+
+	return 0;
+
+#undef seek_forward
+
+fail:
+	git_reflog_entry__free(entry);
+
+	return -1;
+}
+
+static int create_new_reflog_file(const char *filepath)
+{
+	int fd, error;
+
+	if ((error = git_futils_mkpath2file(filepath, GIT_REFLOG_DIR_MODE)) < 0)
+		return error;
+
+	if ((fd = p_open(filepath,
+			O_WRONLY | O_CREAT,
+			GIT_REFLOG_FILE_MODE)) < 0)
+		return -1;
+
+	return p_close(fd);
+}
+
+GIT_INLINE(int) retrieve_reflog_path(git_buf *path, git_repository *repo, const char *name)
+{
+	if (strcmp(name, GIT_HEAD_FILE) == 0)
+		return git_buf_join3(path, '/', repo->gitdir, GIT_REFLOG_DIR, name);
+	return git_buf_join3(path, '/', repo->commondir, GIT_REFLOG_DIR, name);
+}
+
+static int refdb_reflog_fs__ensure_log(git_refdb_backend *_backend, const char *name)
+{
+	refdb_fs_backend *backend;
+	git_repository *repo;
+	git_buf path = GIT_BUF_INIT;
+	int error;
+
+	assert(_backend && name);
+
+	backend = (refdb_fs_backend *) _backend;
+	repo = backend->repo;
+
+	if ((error = retrieve_reflog_path(&path, repo, name)) < 0)
+		return error;
+
+	error = create_new_reflog_file(git_buf_cstr(&path));
+	git_buf_free(&path);
+
+	return error;
+}
+
+static int has_reflog(git_repository *repo, const char *name)
+{
+	int ret = 0;
+	git_buf path = GIT_BUF_INIT;
+
+	if (retrieve_reflog_path(&path, repo, name) < 0)
+		goto cleanup;
+
+	ret = git_path_isfile(git_buf_cstr(&path));
+
+cleanup:
+	git_buf_free(&path);
+	return ret;
+}
+
+static int refdb_reflog_fs__has_log(git_refdb_backend *_backend, const char *name)
+{
+	refdb_fs_backend *backend;
+
+	assert(_backend && name);
+
+	backend = (refdb_fs_backend *) _backend;
+
+	return has_reflog(backend->repo, name);
+}
+
+static int refdb_reflog_fs__read(git_reflog **out, git_refdb_backend *_backend, const char *name)
+{
+	int error = -1;
+	git_buf log_path = GIT_BUF_INIT;
+	git_buf log_file = GIT_BUF_INIT;
+	git_reflog *log = NULL;
+	git_repository *repo;
+	refdb_fs_backend *backend;
+
+	assert(out && _backend && name);
+
+	backend = (refdb_fs_backend *) _backend;
+	repo = backend->repo;
+
+	if (reflog_alloc(&log, name) < 0)
+		return -1;
+
+	if (retrieve_reflog_path(&log_path, repo, name) < 0)
+		goto cleanup;
+
+	error = git_futils_readbuffer(&log_file, git_buf_cstr(&log_path));
+	if (error < 0 && error != GIT_ENOTFOUND)
+		goto cleanup;
+
+	if ((error == GIT_ENOTFOUND) &&
+		((error = create_new_reflog_file(git_buf_cstr(&log_path))) < 0))
+		goto cleanup;
+ 
+	if ((error = reflog_parse(log,
+		git_buf_cstr(&log_file), git_buf_len(&log_file))) < 0)
+		goto cleanup;
+
+	*out = log;
+	goto success;
+
+cleanup:
+	git_reflog_free(log);
+
+success:
+	git_buf_free(&log_file);
+	git_buf_free(&log_path);
+
+	return error;
+}
+
+static int serialize_reflog_entry(
+	git_buf *buf,
+	const git_oid *oid_old,
+	const git_oid *oid_new,
+	const git_signature *committer,
+	const char *msg)
+{
+	char raw_old[GIT_OID_HEXSZ+1];
+	char raw_new[GIT_OID_HEXSZ+1];
+
+	git_oid_tostr(raw_old, GIT_OID_HEXSZ+1, oid_old);
+	git_oid_tostr(raw_new, GIT_OID_HEXSZ+1, oid_new);
+
+	git_buf_clear(buf);
+
+	git_buf_puts(buf, raw_old);
+	git_buf_putc(buf, ' ');
+	git_buf_puts(buf, raw_new);
+
+	git_signature__writebuf(buf, " ", committer);
+
+	/* drop trailing LF */
+	git_buf_rtrim(buf);
+
+	if (msg) {
+		git_buf_putc(buf, '\t');
+		git_buf_puts(buf, msg);
+	}
+
+	git_buf_putc(buf, '\n');
+
+	return git_buf_oom(buf);
+}
+
+static int lock_reflog(git_filebuf *file, refdb_fs_backend *backend, const char *refname)
+{
+	git_repository *repo;
+	git_buf log_path = GIT_BUF_INIT;
+	int error;
+
+	repo = backend->repo;
+
+	if (!git_path_isvalid(backend->repo, refname, 0, GIT_PATH_REJECT_FILESYSTEM_DEFAULTS)) {
+		giterr_set(GITERR_INVALID, "invalid reference name '%s'", refname);
+		return GIT_EINVALIDSPEC;
+	}
+
+	if (retrieve_reflog_path(&log_path, repo, refname) < 0)
+		return -1;
+
+	if (!git_path_isfile(git_buf_cstr(&log_path))) {
+		giterr_set(GITERR_INVALID,
+			"log file for reference '%s' doesn't exist", refname);
+		error = -1;
+		goto cleanup;
+	}
+
+	error = git_filebuf_open(file, git_buf_cstr(&log_path), 0, GIT_REFLOG_FILE_MODE);
+
+cleanup:
+	git_buf_free(&log_path);
+
+	return error;
+}
+
+static int refdb_reflog_fs__write(git_refdb_backend *_backend, git_reflog *reflog)
+{
+	int error = -1;
+	unsigned int i;
+	git_reflog_entry *entry;
+	refdb_fs_backend *backend;
+	git_buf log = GIT_BUF_INIT;
+	git_filebuf fbuf = GIT_FILEBUF_INIT;
+
+	assert(_backend && reflog);
+
+	backend = (refdb_fs_backend *) _backend;
+
+	if ((error = lock_reflog(&fbuf, backend, reflog->ref_name)) < 0)
+		return -1;
+
+	git_vector_foreach(&reflog->entries, i, entry) {
+		if (serialize_reflog_entry(&log, &(entry->oid_old), &(entry->oid_cur), entry->committer, entry->msg) < 0)
+			goto cleanup;
+
+		if ((error = git_filebuf_write(&fbuf, log.ptr, log.size)) < 0)
+			goto cleanup;
+	}
+
+	error = git_filebuf_commit(&fbuf);
+	goto success;
+
+cleanup:
+	git_filebuf_cleanup(&fbuf);
+
+success:
+	git_buf_free(&log);
+
+	return error;
+}
+
+/* Append to the reflog, must be called under reference lock */
+static int reflog_append(refdb_fs_backend *backend, const git_reference *ref, const git_oid *old, const git_oid *new, const git_signature *who, const char *message)
+{
+	int error, is_symbolic, open_flags;
+	git_oid old_id = {{0}}, new_id = {{0}};
+	git_buf buf = GIT_BUF_INIT, path = GIT_BUF_INIT;
+	git_repository *repo = backend->repo;
+
+	is_symbolic = ref->type == GIT_REF_SYMBOLIC;
+
+	/* "normal" symbolic updates do not write */
+	if (is_symbolic &&
+	    strcmp(ref->name, GIT_HEAD_FILE) &&
+	    !(old && new))
+		return 0;
+
+	/* From here on is_symoblic also means that it's HEAD */
+
+	if (old) {
+		git_oid_cpy(&old_id, old);
+	} else {
+		error = git_reference_name_to_id(&old_id, repo, ref->name);
+		if (error < 0 && error != GIT_ENOTFOUND)
+			return error;
+	}
+
+	if (new) {
+		git_oid_cpy(&new_id, new);
+	} else {
+		if (!is_symbolic) {
+			git_oid_cpy(&new_id, git_reference_target(ref));
+		} else {
+			error = git_reference_name_to_id(&new_id, repo, git_reference_symbolic_target(ref));
+			if (error < 0 && error != GIT_ENOTFOUND)
+				return error;
+			/* detaching HEAD does not create an entry */
+			if (error == GIT_ENOTFOUND)
+				return 0;
+
+			giterr_clear();
+		}
+	}
+
+	if ((error = serialize_reflog_entry(&buf, &old_id, &new_id, who, message)) < 0)
+		goto cleanup;
+
+	if ((error = retrieve_reflog_path(&path, repo, ref->name)) < 0)
+		goto cleanup;
+
+	if (((error = git_futils_mkpath2file(git_buf_cstr(&path), 0777)) < 0) &&
+	    (error != GIT_EEXISTS)) {
+		goto cleanup;
+	}
+
+	/* If the new branch matches part of the namespace of a previously deleted branch,
+	 * there maybe an obsolete/unused directory (or directory hierarchy) in the way.
+	 */
+	if (git_path_isdir(git_buf_cstr(&path))) {
+		if ((error = git_futils_rmdir_r(git_buf_cstr(&path), NULL, GIT_RMDIR_SKIP_NONEMPTY)) < 0) {
+			if (error == GIT_ENOTFOUND)
+				error = 0;
+		} else if (git_path_isdir(git_buf_cstr(&path))) {
+			giterr_set(GITERR_REFERENCE, "cannot create reflog at '%s', there are reflogs beneath that folder",
+				ref->name);
+			error = GIT_EDIRECTORY;
+		}
+
+		if (error != 0)
+			goto cleanup;
+	}
+
+	open_flags = O_WRONLY | O_CREAT | O_APPEND;
+
+	if (backend->fsync)
+		open_flags |= O_FSYNC;
+
+	error = git_futils_writebuffer(&buf, git_buf_cstr(&path), open_flags, GIT_REFLOG_FILE_MODE);
+
+cleanup:
+	git_buf_free(&buf);
+	git_buf_free(&path);
+
+	return error;
+}
+
+static int refdb_reflog_fs__rename(git_refdb_backend *_backend, const char *old_name, const char *new_name)
+{
+	int error = 0, fd;
+	git_buf old_path = GIT_BUF_INIT;
+	git_buf new_path = GIT_BUF_INIT;
+	git_buf temp_path = GIT_BUF_INIT;
+	git_buf normalized = GIT_BUF_INIT;
+	git_repository *repo;
+	refdb_fs_backend *backend;
+
+	assert(_backend && old_name && new_name);
+
+	backend = (refdb_fs_backend *) _backend;
+	repo = backend->repo;
+
+	if ((error = git_reference__normalize_name(
+		&normalized, new_name, GIT_REF_FORMAT_ALLOW_ONELEVEL)) < 0)
+			return error;
+
+	if (git_buf_joinpath(&temp_path, repo->gitdir, GIT_REFLOG_DIR) < 0)
+		return -1;
+
+	if (git_buf_joinpath(&old_path, git_buf_cstr(&temp_path), old_name) < 0)
+		return -1;
+
+	if (git_buf_joinpath(&new_path, git_buf_cstr(&temp_path), git_buf_cstr(&normalized)) < 0)
+		return -1;
+
+	if (!git_path_exists(git_buf_cstr(&old_path))) {
+		error = GIT_ENOTFOUND;
+		goto cleanup;
+	}
+
+	/*
+	 * Move the reflog to a temporary place. This two-phase renaming is required
+	 * in order to cope with funny renaming use cases when one tries to move a reference
+	 * to a partially colliding namespace:
+	 *  - a/b -> a/b/c
+	 *  - a/b/c/d -> a/b/c
+	 */
+	if (git_buf_joinpath(&temp_path, git_buf_cstr(&temp_path), "temp_reflog") < 0)
+		return -1;
+
+	if ((fd = git_futils_mktmp(&temp_path, git_buf_cstr(&temp_path), GIT_REFLOG_FILE_MODE)) < 0) {
+		error = -1;
+		goto cleanup;
+	}
+
+	p_close(fd);
+
+	if (p_rename(git_buf_cstr(&old_path), git_buf_cstr(&temp_path)) < 0) {
+		giterr_set(GITERR_OS, "failed to rename reflog for %s", new_name);
+		error = -1;
+		goto cleanup;
+	}
+
+	if (git_path_isdir(git_buf_cstr(&new_path)) && 
+		(git_futils_rmdir_r(git_buf_cstr(&new_path), NULL, GIT_RMDIR_SKIP_NONEMPTY) < 0)) {
+		error = -1;
+		goto cleanup;
+	}
+
+	if (git_futils_mkpath2file(git_buf_cstr(&new_path), GIT_REFLOG_DIR_MODE) < 0) {
+		error = -1;
+		goto cleanup;
+	}
+
+	if (p_rename(git_buf_cstr(&temp_path), git_buf_cstr(&new_path)) < 0) {
+		giterr_set(GITERR_OS, "failed to rename reflog for %s", new_name);
+		error = -1;
+	}
+
+cleanup:
+	git_buf_free(&temp_path);
+	git_buf_free(&old_path);
+	git_buf_free(&new_path);
+	git_buf_free(&normalized);
+
+	return error;
+}
+
+static int refdb_reflog_fs__delete(git_refdb_backend *_backend, const char *name)
+{
+	int error;
+	git_buf path = GIT_BUF_INIT;
+
+	git_repository *repo;
+	refdb_fs_backend *backend;
+
+	assert(_backend && name);
+
+	backend = (refdb_fs_backend *) _backend;
+	repo = backend->repo;
+
+	error = retrieve_reflog_path(&path, repo, name);
+
+	if (!error && git_path_exists(path.ptr))
+		error = p_unlink(path.ptr);
+
+	git_buf_free(&path);
+
+	return error;
+
+}
+
+int git_refdb_backend_fs(
+	git_refdb_backend **backend_out,
+	git_repository *repository)
+{
+	int t = 0;
+	git_buf gitpath = GIT_BUF_INIT;
+	refdb_fs_backend *backend;
+
+	backend = git__calloc(1, sizeof(refdb_fs_backend));
+	GITERR_CHECK_ALLOC(backend);
+
+	backend->repo = repository;
+
+	if (repository->gitdir) {
+		backend->gitpath = setup_namespace(repository, repository->gitdir);
+
+		if (backend->gitpath == NULL)
+			goto fail;
+	}
+
+	if (repository->commondir) {
+		backend->commonpath = setup_namespace(repository, repository->commondir);
+
+		if (backend->commonpath == NULL)
+			goto fail;
+	}
+
+	if (git_buf_joinpath(&gitpath, backend->commonpath, GIT_PACKEDREFS_FILE) < 0 ||
+		git_sortedcache_new(
+			&backend->refcache, offsetof(struct packref, name),
+			NULL, NULL, packref_cmp, git_buf_cstr(&gitpath)) < 0)
+		goto fail;
+
+	git_buf_free(&gitpath);
+
+	if (!git_repository__cvar(&t, backend->repo, GIT_CVAR_IGNORECASE) && t) {
+		backend->iterator_flags |= GIT_ITERATOR_IGNORE_CASE;
+		backend->direach_flags  |= GIT_PATH_DIR_IGNORE_CASE;
+	}
+	if (!git_repository__cvar(&t, backend->repo, GIT_CVAR_PRECOMPOSE) && t) {
+		backend->iterator_flags |= GIT_ITERATOR_PRECOMPOSE_UNICODE;
+		backend->direach_flags  |= GIT_PATH_DIR_PRECOMPOSE_UNICODE;
+	}
+	if ((!git_repository__cvar(&t, backend->repo, GIT_CVAR_FSYNCOBJECTFILES) && t) ||
+		git_repository__fsync_gitdir)
+		backend->fsync = 1;
+	backend->iterator_flags |= GIT_ITERATOR_DESCEND_SYMLINKS;
+
+	backend->parent.exists = &refdb_fs_backend__exists;
+	backend->parent.lookup = &refdb_fs_backend__lookup;
+	backend->parent.iterator = &refdb_fs_backend__iterator;
+	backend->parent.write = &refdb_fs_backend__write;
+	backend->parent.del = &refdb_fs_backend__delete;
+	backend->parent.rename = &refdb_fs_backend__rename;
+	backend->parent.compress = &refdb_fs_backend__compress;
+	backend->parent.lock = &refdb_fs_backend__lock;
+	backend->parent.unlock = &refdb_fs_backend__unlock;
+	backend->parent.has_log = &refdb_reflog_fs__has_log;
+	backend->parent.ensure_log = &refdb_reflog_fs__ensure_log;
+	backend->parent.free = &refdb_fs_backend__free;
+	backend->parent.reflog_read = &refdb_reflog_fs__read;
+	backend->parent.reflog_write = &refdb_reflog_fs__write;
+	backend->parent.reflog_rename = &refdb_reflog_fs__rename;
+	backend->parent.reflog_delete = &refdb_reflog_fs__delete;
+
+	*backend_out = (git_refdb_backend *)backend;
+	return 0;
+
+fail:
+	git_buf_free(&gitpath);
+	git__free(backend->gitpath);
+	git__free(backend->commonpath);
+	git__free(backend);
+	return -1;
+}

vendor/libgit2-sys/libgit2/src/refdb_fs.h

diff --git a/vendor/libgit2-sys/libgit2/src/refdb_fs.h b/vendor/libgit2-sys/libgit2/src/refdb_fs.h
new file mode 100644
index 0000000..0c84814
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/refdb_fs.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_refdb_fs_h__
+#define INCLUDE_refdb_fs_h__
+
+#include "common.h"
+
+#include "strmap.h"
+
+typedef struct {
+	git_strmap *packfile;
+	time_t packfile_time;
+} git_refcache;
+
+#endif

vendor/libgit2-sys/libgit2/src/reflog.c

diff --git a/vendor/libgit2-sys/libgit2/src/reflog.c b/vendor/libgit2-sys/libgit2/src/reflog.c
new file mode 100644
index 0000000..9389992
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/reflog.c
@@ -0,0 +1,233 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "reflog.h"
+
+#include "repository.h"
+#include "filebuf.h"
+#include "signature.h"
+#include "refdb.h"
+
+#include <git2/sys/refdb_backend.h>
+
+git_reflog_entry *git_reflog_entry__alloc(void)
+{
+	return git__calloc(1, sizeof(git_reflog_entry));
+}
+
+void git_reflog_entry__free(git_reflog_entry *entry)
+{
+	git_signature_free(entry->committer);
+
+	git__free(entry->msg);
+	git__free(entry);
+}
+
+void git_reflog_free(git_reflog *reflog)
+{
+	size_t i;
+	git_reflog_entry *entry;
+
+	if (reflog == NULL)
+		return;
+
+	if (reflog->db)
+		GIT_REFCOUNT_DEC(reflog->db, git_refdb__free);
+
+	for (i=0; i < reflog->entries.length; i++) {
+		entry = git_vector_get(&reflog->entries, i);
+
+		git_reflog_entry__free(entry);
+	}
+
+	git_vector_free(&reflog->entries);
+	git__free(reflog->ref_name);
+	git__free(reflog);
+}
+
+int git_reflog_read(git_reflog **reflog, git_repository *repo,  const char *name)
+{
+	git_refdb *refdb;
+	int error;
+
+	assert(reflog && repo && name);
+
+	if ((error = git_repository_refdb__weakptr(&refdb, repo)) < 0)
+		return error;
+
+	return git_refdb_reflog_read(reflog, refdb, name);
+}
+
+int git_reflog_write(git_reflog *reflog)
+{
+	git_refdb *db;
+
+	assert(reflog && reflog->db);
+
+	db = reflog->db;
+	return db->backend->reflog_write(db->backend, reflog);
+}
+
+int git_reflog_append(git_reflog *reflog, const git_oid *new_oid, const git_signature *committer, const char *msg)
+{
+	git_reflog_entry *entry;
+	const git_reflog_entry *previous;
+	const char *newline;
+
+	assert(reflog && new_oid && committer);
+
+	entry = git__calloc(1, sizeof(git_reflog_entry));
+	GITERR_CHECK_ALLOC(entry);
+
+	if ((git_signature_dup(&entry->committer, committer)) < 0)
+		goto cleanup;
+
+	if (msg != NULL) {
+		if ((entry->msg = git__strdup(msg)) == NULL)
+			goto cleanup;
+
+		newline = strchr(msg, '\n');
+
+		if (newline) {
+			if (newline[1] != '\0') {
+				giterr_set(GITERR_INVALID, "reflog message cannot contain newline");
+				goto cleanup;
+			}
+
+			entry->msg[newline - msg] = '\0';
+		}
+	}
+
+	previous = git_reflog_entry_byindex(reflog, 0);
+
+	if (previous == NULL)
+		git_oid_fromstr(&entry->oid_old, GIT_OID_HEX_ZERO);
+	else
+		git_oid_cpy(&entry->oid_old, &previous->oid_cur);
+
+	git_oid_cpy(&entry->oid_cur, new_oid);
+
+	if (git_vector_insert(&reflog->entries, entry) < 0)
+		goto cleanup;
+
+	return 0;
+
+cleanup:
+	git_reflog_entry__free(entry);
+	return -1;
+}
+
+int git_reflog_rename(git_repository *repo, const char *old_name, const char *new_name)
+{
+	git_refdb *refdb;
+	int error;
+
+	if ((error = git_repository_refdb__weakptr(&refdb, repo)) < 0)
+		return -1;
+
+	return refdb->backend->reflog_rename(refdb->backend, old_name, new_name);
+}
+
+int git_reflog_delete(git_repository *repo, const char *name)
+{
+	git_refdb *refdb;
+	int error;
+
+	if ((error = git_repository_refdb__weakptr(&refdb, repo)) < 0)
+		return -1;
+
+	return refdb->backend->reflog_delete(refdb->backend, name);
+}
+
+size_t git_reflog_entrycount(git_reflog *reflog)
+{
+	assert(reflog);
+	return reflog->entries.length;
+}
+
+const git_reflog_entry * git_reflog_entry_byindex(const git_reflog *reflog, size_t idx)
+{
+	assert(reflog);
+
+	if (idx >= reflog->entries.length)
+		return NULL;
+
+	return git_vector_get(
+		&reflog->entries, reflog_inverse_index(idx, reflog->entries.length));
+}
+
+const git_oid * git_reflog_entry_id_old(const git_reflog_entry *entry)
+{
+	assert(entry);
+	return &entry->oid_old;
+}
+
+const git_oid * git_reflog_entry_id_new(const git_reflog_entry *entry)
+{
+	assert(entry);
+	return &entry->oid_cur;
+}
+
+const git_signature * git_reflog_entry_committer(const git_reflog_entry *entry)
+{
+	assert(entry);
+	return entry->committer;
+}
+
+const char * git_reflog_entry_message(const git_reflog_entry *entry)
+{
+	assert(entry);
+	return entry->msg;
+}
+
+int git_reflog_drop(git_reflog *reflog, size_t idx, int rewrite_previous_entry)
+{
+	size_t entrycount;
+	git_reflog_entry *entry, *previous;
+
+	entrycount = git_reflog_entrycount(reflog);
+
+	entry = (git_reflog_entry *)git_reflog_entry_byindex(reflog, idx);
+
+	if (entry == NULL) {
+		giterr_set(GITERR_REFERENCE, "no reflog entry at index %"PRIuZ, idx);
+		return GIT_ENOTFOUND;
+	}
+
+	git_reflog_entry__free(entry);
+
+	if (git_vector_remove(
+			&reflog->entries, reflog_inverse_index(idx, entrycount)) < 0)
+		return -1;
+
+	if (!rewrite_previous_entry)
+		return 0;
+
+	/* No need to rewrite anything when removing the most recent entry */
+	if (idx == 0)
+		return 0;
+
+	/* Have the latest entry just been dropped? */
+	if (entrycount == 1)
+		return 0;
+
+	entry = (git_reflog_entry *)git_reflog_entry_byindex(reflog, idx - 1);
+
+	/* If the oldest entry has just been removed... */
+	if (idx == entrycount - 1) {
+		/* ...clear the oid_old member of the "new" oldest entry */
+		if (git_oid_fromstr(&entry->oid_old, GIT_OID_HEX_ZERO) < 0)
+			return -1;
+
+		return 0;
+	}
+
+	previous = (git_reflog_entry *)git_reflog_entry_byindex(reflog, idx);
+	git_oid_cpy(&entry->oid_old, &previous->oid_cur);
+
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/reflog.h

diff --git a/vendor/libgit2-sys/libgit2/src/reflog.h b/vendor/libgit2-sys/libgit2/src/reflog.h
new file mode 100644
index 0000000..8c38959
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/reflog.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_reflog_h__
+#define INCLUDE_reflog_h__
+
+#include "common.h"
+
+#include "git2/reflog.h"
+#include "vector.h"
+
+#define GIT_REFLOG_DIR "logs/"
+#define GIT_REFLOG_DIR_MODE 0777
+#define GIT_REFLOG_FILE_MODE 0666
+
+#define GIT_REFLOG_SIZE_MIN (2*GIT_OID_HEXSZ+2+17)
+
+struct git_reflog_entry {
+	git_oid oid_old;
+	git_oid oid_cur;
+
+	git_signature *committer;
+
+	char *msg;
+};
+
+struct git_reflog {
+	git_refdb *db;
+	char *ref_name;
+	git_vector entries;
+};
+
+GIT_INLINE(size_t) reflog_inverse_index(size_t idx, size_t total)
+{
+	return (total - 1) - idx;
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/refs.c

diff --git a/vendor/libgit2-sys/libgit2/src/refs.c b/vendor/libgit2-sys/libgit2/src/refs.c
new file mode 100644
index 0000000..c429683
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/refs.c
@@ -0,0 +1,1432 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "refs.h"
+
+#include "hash.h"
+#include "repository.h"
+#include "fileops.h"
+#include "filebuf.h"
+#include "pack.h"
+#include "reflog.h"
+#include "refdb.h"
+
+#include <git2/tag.h>
+#include <git2/object.h>
+#include <git2/oid.h>
+#include <git2/branch.h>
+#include <git2/refs.h>
+#include <git2/refdb.h>
+#include <git2/sys/refs.h>
+#include <git2/signature.h>
+#include <git2/commit.h>
+
+bool git_reference__enable_symbolic_ref_target_validation = true;
+
+#define DEFAULT_NESTING_LEVEL	5
+#define MAX_NESTING_LEVEL		10
+
+enum {
+	GIT_PACKREF_HAS_PEEL = 1,
+	GIT_PACKREF_WAS_LOOSE = 2
+};
+
+static git_reference *alloc_ref(const char *name)
+{
+	git_reference *ref = NULL;
+	size_t namelen = strlen(name), reflen;
+
+	if (!GIT_ADD_SIZET_OVERFLOW(&reflen, sizeof(git_reference), namelen) &&
+		!GIT_ADD_SIZET_OVERFLOW(&reflen, reflen, 1) &&
+		(ref = git__calloc(1, reflen)) != NULL)
+		memcpy(ref->name, name, namelen + 1);
+
+	return ref;
+}
+
+git_reference *git_reference__alloc_symbolic(
+	const char *name, const char *target)
+{
+	git_reference *ref;
+
+	assert(name && target);
+
+	ref = alloc_ref(name);
+	if (!ref)
+		return NULL;
+
+	ref->type = GIT_REF_SYMBOLIC;
+
+	if ((ref->target.symbolic = git__strdup(target)) == NULL) {
+		git__free(ref);
+		return NULL;
+	}
+
+	return ref;
+}
+
+git_reference *git_reference__alloc(
+	const char *name,
+	const git_oid *oid,
+	const git_oid *peel)
+{
+	git_reference *ref;
+
+	assert(name && oid);
+
+	ref = alloc_ref(name);
+	if (!ref)
+		return NULL;
+
+	ref->type = GIT_REF_OID;
+	git_oid_cpy(&ref->target.oid, oid);
+
+	if (peel != NULL)
+		git_oid_cpy(&ref->peel, peel);
+
+	return ref;
+}
+
+git_reference *git_reference__set_name(
+	git_reference *ref, const char *name)
+{
+	size_t namelen = strlen(name);
+	size_t reflen;
+	git_reference *rewrite = NULL;
+
+	if (!GIT_ADD_SIZET_OVERFLOW(&reflen, sizeof(git_reference), namelen) &&
+		!GIT_ADD_SIZET_OVERFLOW(&reflen, reflen, 1) &&
+		(rewrite = git__realloc(ref, reflen)) != NULL)
+		memcpy(rewrite->name, name, namelen + 1);
+
+	return rewrite;
+}
+
+int git_reference_dup(git_reference **dest, git_reference *source)
+{
+	if (source->type == GIT_REF_SYMBOLIC)
+		*dest = git_reference__alloc_symbolic(source->name, source->target.symbolic);
+	else
+		*dest = git_reference__alloc(source->name, &source->target.oid, &source->peel);
+
+	GITERR_CHECK_ALLOC(*dest);
+
+	(*dest)->db = source->db;
+	GIT_REFCOUNT_INC((*dest)->db);
+
+	return 0;
+}
+
+void git_reference_free(git_reference *reference)
+{
+	if (reference == NULL)
+		return;
+
+	if (reference->type == GIT_REF_SYMBOLIC)
+		git__free(reference->target.symbolic);
+
+	if (reference->db)
+		GIT_REFCOUNT_DEC(reference->db, git_refdb__free);
+
+	git__free(reference);
+}
+
+int git_reference_delete(git_reference *ref)
+{
+	const git_oid *old_id = NULL;
+	const char *old_target = NULL;
+
+	if (ref->type == GIT_REF_OID)
+		old_id = &ref->target.oid;
+	else
+		old_target = ref->target.symbolic;
+
+	return git_refdb_delete(ref->db, ref->name, old_id, old_target);
+}
+
+int git_reference_remove(git_repository *repo, const char *name)
+{
+	git_refdb *db;
+	int error;
+
+	if ((error = git_repository_refdb__weakptr(&db, repo)) < 0)
+		return error;
+
+	return git_refdb_delete(db, name, NULL, NULL);
+}
+
+int git_reference_lookup(git_reference **ref_out,
+	git_repository *repo, const char *name)
+{
+	return git_reference_lookup_resolved(ref_out, repo, name, 0);
+}
+
+int git_reference_name_to_id(
+	git_oid *out, git_repository *repo, const char *name)
+{
+	int error;
+	git_reference *ref;
+
+	if ((error = git_reference_lookup_resolved(&ref, repo, name, -1)) < 0)
+		return error;
+
+	git_oid_cpy(out, git_reference_target(ref));
+	git_reference_free(ref);
+	return 0;
+}
+
+static int reference_normalize_for_repo(
+	git_refname_t out,
+	git_repository *repo,
+	const char *name,
+	bool validate)
+{
+	int precompose;
+	unsigned int flags = GIT_REF_FORMAT_ALLOW_ONELEVEL;
+
+	if (!git_repository__cvar(&precompose, repo, GIT_CVAR_PRECOMPOSE) &&
+		precompose)
+		flags |= GIT_REF_FORMAT__PRECOMPOSE_UNICODE;
+
+	if (!validate)
+		flags |= GIT_REF_FORMAT__VALIDATION_DISABLE;
+
+	return git_reference_normalize_name(out, GIT_REFNAME_MAX, name, flags);
+}
+
+int git_reference_lookup_resolved(
+	git_reference **ref_out,
+	git_repository *repo,
+	const char *name,
+	int max_nesting)
+{
+	git_refname_t scan_name;
+	git_ref_t scan_type;
+	int error = 0, nesting;
+	git_reference *ref = NULL;
+	git_refdb *refdb;
+
+	assert(ref_out && repo && name);
+
+	*ref_out = NULL;
+
+	if (max_nesting > MAX_NESTING_LEVEL)
+		max_nesting = MAX_NESTING_LEVEL;
+	else if (max_nesting < 0)
+		max_nesting = DEFAULT_NESTING_LEVEL;
+
+	scan_type = GIT_REF_SYMBOLIC;
+
+	if ((error = reference_normalize_for_repo(scan_name, repo, name, true)) < 0)
+		return error;
+
+	if ((error = git_repository_refdb__weakptr(&refdb, repo)) < 0)
+		return error;
+
+	for (nesting = max_nesting;
+		 nesting >= 0 && scan_type == GIT_REF_SYMBOLIC;
+		 nesting--)
+	{
+		if (nesting != max_nesting) {
+			strncpy(scan_name, ref->target.symbolic, sizeof(scan_name));
+			git_reference_free(ref);
+		}
+
+		if ((error = git_refdb_lookup(&ref, refdb, scan_name)) < 0)
+			return error;
+
+		scan_type = ref->type;
+	}
+
+	if (scan_type != GIT_REF_OID && max_nesting != 0) {
+		giterr_set(GITERR_REFERENCE,
+			"cannot resolve reference (>%u levels deep)", max_nesting);
+		git_reference_free(ref);
+		return -1;
+	}
+
+	*ref_out = ref;
+	return 0;
+}
+
+int git_reference__read_head(
+	git_reference **out,
+	git_repository *repo,
+	const char *path)
+{
+	git_buf reference = GIT_BUF_INIT;
+	char *name = NULL;
+	int error;
+
+	if ((error = git_futils_readbuffer(&reference, path)) < 0)
+		goto out;
+	git_buf_rtrim(&reference);
+
+	if (git__strncmp(reference.ptr, GIT_SYMREF, strlen(GIT_SYMREF)) == 0) {
+		git_buf_consume(&reference, reference.ptr + strlen(GIT_SYMREF));
+
+		name = git_path_basename(path);
+
+		if ((*out = git_reference__alloc_symbolic(name, reference.ptr)) == NULL) {
+			error = -1;
+			goto out;
+		}
+	} else {
+		if ((error = git_reference_lookup(out, repo, reference.ptr)) < 0)
+			goto out;
+	}
+
+out:
+	git__free(name);
+	git_buf_free(&reference);
+
+	return error;
+}
+
+int git_reference_dwim(git_reference **out, git_repository *repo, const char *refname)
+{
+	int error = 0, i;
+	bool fallbackmode = true, foundvalid = false;
+	git_reference *ref;
+	git_buf refnamebuf = GIT_BUF_INIT, name = GIT_BUF_INIT;
+
+	static const char* formatters[] = {
+		"%s",
+		GIT_REFS_DIR "%s",
+		GIT_REFS_TAGS_DIR "%s",
+		GIT_REFS_HEADS_DIR "%s",
+		GIT_REFS_REMOTES_DIR "%s",
+		GIT_REFS_REMOTES_DIR "%s/" GIT_HEAD_FILE,
+		NULL
+	};
+
+	if (*refname)
+		git_buf_puts(&name, refname);
+	else {
+		git_buf_puts(&name, GIT_HEAD_FILE);
+		fallbackmode = false;
+	}
+
+	for (i = 0; formatters[i] && (fallbackmode || i == 0); i++) {
+
+		git_buf_clear(&refnamebuf);
+
+		if ((error = git_buf_printf(&refnamebuf, formatters[i], git_buf_cstr(&name))) < 0)
+			goto cleanup;
+
+		if (!git_reference_is_valid_name(git_buf_cstr(&refnamebuf))) {
+			error = GIT_EINVALIDSPEC;
+			continue;
+		}
+		foundvalid = true;
+
+		error = git_reference_lookup_resolved(&ref, repo, git_buf_cstr(&refnamebuf), -1);
+
+		if (!error) {
+			*out = ref;
+			error = 0;
+			goto cleanup;
+		}
+
+		if (error != GIT_ENOTFOUND)
+			goto cleanup;
+	}
+
+cleanup:
+	if (error && !foundvalid) {
+		/* never found a valid reference name */
+		giterr_set(GITERR_REFERENCE,
+			"could not use '%s' as valid reference name", git_buf_cstr(&name));
+	}
+
+	if (error == GIT_ENOTFOUND)
+		giterr_set(GITERR_REFERENCE, "no reference found for shorthand '%s'", refname);
+
+	git_buf_free(&name);
+	git_buf_free(&refnamebuf);
+	return error;
+}
+
+/**
+ * Getters
+ */
+git_ref_t git_reference_type(const git_reference *ref)
+{
+	assert(ref);
+	return ref->type;
+}
+
+const char *git_reference_name(const git_reference *ref)
+{
+	assert(ref);
+	return ref->name;
+}
+
+git_repository *git_reference_owner(const git_reference *ref)
+{
+	assert(ref);
+	return ref->db->repo;
+}
+
+const git_oid *git_reference_target(const git_reference *ref)
+{
+	assert(ref);
+
+	if (ref->type != GIT_REF_OID)
+		return NULL;
+
+	return &ref->target.oid;
+}
+
+const git_oid *git_reference_target_peel(const git_reference *ref)
+{
+	assert(ref);
+
+	if (ref->type != GIT_REF_OID || git_oid_iszero(&ref->peel))
+		return NULL;
+
+	return &ref->peel;
+}
+
+const char *git_reference_symbolic_target(const git_reference *ref)
+{
+	assert(ref);
+
+	if (ref->type != GIT_REF_SYMBOLIC)
+		return NULL;
+
+	return ref->target.symbolic;
+}
+
+static int reference__create(
+	git_reference **ref_out,
+	git_repository *repo,
+	const char *name,
+	const git_oid *oid,
+	const char *symbolic,
+	int force,
+	const git_signature *signature,
+	const char *log_message,
+	const git_oid *old_id,
+	const char *old_target)
+{
+	git_refname_t normalized;
+	git_refdb *refdb;
+	git_reference *ref = NULL;
+	int error = 0;
+
+	assert(repo && name);
+	assert(symbolic || signature);
+
+	if (ref_out)
+		*ref_out = NULL;
+
+	error = reference_normalize_for_repo(normalized, repo, name, true);
+	if (error < 0)
+		return error;
+
+	error = git_repository_refdb__weakptr(&refdb, repo);
+	if (error < 0)
+		return error;
+
+	if (oid != NULL) {
+		assert(symbolic == NULL);
+
+		if (!git_object__is_valid(repo, oid, GIT_OBJ_ANY)) {
+			giterr_set(GITERR_REFERENCE,
+				"target OID for the reference doesn't exist on the repository");
+			return -1;
+		}
+
+		ref = git_reference__alloc(normalized, oid, NULL);
+	} else {
+		git_refname_t normalized_target;
+
+		error = reference_normalize_for_repo(normalized_target, repo,
+			symbolic, git_reference__enable_symbolic_ref_target_validation);
+
+		if (error < 0)
+			return error;
+
+		ref = git_reference__alloc_symbolic(normalized, normalized_target);
+	}
+
+	GITERR_CHECK_ALLOC(ref);
+
+	if ((error = git_refdb_write(refdb, ref, force, signature, log_message, old_id, old_target)) < 0) {
+		git_reference_free(ref);
+		return error;
+	}
+
+	if (ref_out == NULL)
+		git_reference_free(ref);
+	else
+		*ref_out = ref;
+
+	return 0;
+}
+
+int configured_ident(git_signature **out, const git_repository *repo)
+{
+	if (repo->ident_name && repo->ident_email)
+		return git_signature_now(out, repo->ident_name, repo->ident_email);
+
+	/* if not configured let us fall-through to the next method  */
+	return -1;
+}
+
+int git_reference__log_signature(git_signature **out, git_repository *repo)
+{
+	int error;
+	git_signature *who;
+
+	if(((error = configured_ident(&who, repo)) < 0) &&
+	   ((error = git_signature_default(&who, repo)) < 0) &&
+	   ((error = git_signature_now(&who, "unknown", "unknown")) < 0))
+		return error;
+
+	*out = who;
+	return 0;
+}
+
+int git_reference_create_matching(
+	git_reference **ref_out,
+	git_repository *repo,
+	const char *name,
+	const git_oid *id,
+	int force,
+	const git_oid *old_id,
+	const char *log_message)
+
+{
+	int error;
+	git_signature *who = NULL;
+
+	assert(id);
+
+	if ((error = git_reference__log_signature(&who, repo)) < 0)
+		return error;
+
+	error = reference__create(
+		ref_out, repo, name, id, NULL, force, who, log_message, old_id, NULL);
+
+	git_signature_free(who);
+	return error;
+}
+
+int git_reference_create(
+	git_reference **ref_out,
+	git_repository *repo,
+	const char *name,
+	const git_oid *id,
+	int force,
+	const char *log_message)
+{
+        return git_reference_create_matching(ref_out, repo, name, id, force, NULL, log_message);
+}
+
+int git_reference_symbolic_create_matching(
+	git_reference **ref_out,
+	git_repository *repo,
+	const char *name,
+	const char *target,
+	int force,
+	const char *old_target,
+	const char *log_message)
+{
+	int error;
+	git_signature *who = NULL;
+
+	assert(target);
+
+	if ((error = git_reference__log_signature(&who, repo)) < 0)
+		return error;
+
+	error = reference__create(
+		ref_out, repo, name, NULL, target, force, who, log_message, NULL, old_target);
+
+	git_signature_free(who);
+	return error;
+}
+
+int git_reference_symbolic_create(
+	git_reference **ref_out,
+	git_repository *repo,
+	const char *name,
+	const char *target,
+	int force,
+	const char *log_message)
+{
+	return git_reference_symbolic_create_matching(ref_out, repo, name, target, force, NULL, log_message);
+}
+
+static int ensure_is_an_updatable_direct_reference(git_reference *ref)
+{
+	if (ref->type == GIT_REF_OID)
+		return 0;
+
+	giterr_set(GITERR_REFERENCE, "cannot set OID on symbolic reference");
+	return -1;
+}
+
+int git_reference_set_target(
+	git_reference **out,
+	git_reference *ref,
+	const git_oid *id,
+	const char *log_message)
+{
+	int error;
+	git_repository *repo;
+
+	assert(out && ref && id);
+
+	repo = ref->db->repo;
+
+	if ((error = ensure_is_an_updatable_direct_reference(ref)) < 0)
+		return error;
+
+	return git_reference_create_matching(out, repo, ref->name, id, 1, &ref->target.oid, log_message);
+}
+
+static int ensure_is_an_updatable_symbolic_reference(git_reference *ref)
+{
+	if (ref->type == GIT_REF_SYMBOLIC)
+		return 0;
+
+	giterr_set(GITERR_REFERENCE, "cannot set symbolic target on a direct reference");
+	return -1;
+}
+
+int git_reference_symbolic_set_target(
+	git_reference **out,
+	git_reference *ref,
+	const char *target,
+	const char *log_message)
+{
+	int error;
+
+	assert(out && ref && target);
+
+	if ((error = ensure_is_an_updatable_symbolic_reference(ref)) < 0)
+		return error;
+
+	return git_reference_symbolic_create_matching(
+		out, ref->db->repo, ref->name, target, 1, ref->target.symbolic, log_message);
+}
+
+typedef struct {
+    const char *old_name;
+    git_refname_t new_name;
+} rename_cb_data;
+
+static int update_wt_heads(git_repository *repo, const char *path, void *payload)
+{
+	rename_cb_data *data = (rename_cb_data *) payload;
+	git_reference *head = NULL;
+	char *gitdir = NULL;
+	int error;
+
+	if ((error = git_reference__read_head(&head, repo, path)) < 0) {
+		giterr_set(GITERR_REFERENCE, "could not read HEAD when renaming references");
+		goto out;
+	}
+
+	if ((gitdir = git_path_dirname(path)) == NULL) {
+		error = -1;
+		goto out;
+	}
+
+	if (git_reference_type(head) != GIT_REF_SYMBOLIC ||
+	    git__strcmp(head->target.symbolic, data->old_name) != 0) {
+		error = 0;
+		goto out;
+	}
+
+	/* Update HEAD it was pointing to the reference being renamed */
+	if ((error = git_repository_create_head(gitdir, data->new_name)) < 0) {
+		giterr_set(GITERR_REFERENCE, "failed to update HEAD after renaming reference");
+		goto out;
+	}
+
+out:
+	git_reference_free(head);
+	git__free(gitdir);
+
+	return error;
+}
+
+static int reference__rename(git_reference **out, git_reference *ref, const char *new_name, int force,
+				 const git_signature *signature, const char *message)
+{
+	git_repository *repo;
+	git_refname_t normalized;
+	bool should_head_be_updated = false;
+	int error = 0;
+
+	assert(ref && new_name && signature);
+
+	repo = git_reference_owner(ref);
+
+	if ((error = reference_normalize_for_repo(
+		normalized, repo, new_name, true)) < 0)
+		return error;
+
+	/* Check if we have to update HEAD. */
+	if ((error = git_branch_is_head(ref)) < 0)
+		return error;
+
+	should_head_be_updated = (error > 0);
+
+	if ((error = git_refdb_rename(out, ref->db, ref->name, normalized, force, signature, message)) < 0)
+		return error;
+
+	/* Update HEAD if it was pointing to the reference being renamed */
+	if (should_head_be_updated) {
+		error = git_repository_set_head(ref->db->repo, normalized);
+	} else {
+		rename_cb_data payload;
+		payload.old_name = ref->name;
+		memcpy(&payload.new_name, &normalized, sizeof(normalized));
+
+		error = git_repository_foreach_head(repo, update_wt_heads, &payload);
+	}
+
+	return error;
+}
+
+
+int git_reference_rename(
+	git_reference **out,
+	git_reference *ref,
+	const char *new_name,
+	int force,
+	const char *log_message)
+{
+	git_signature *who;
+	int error;
+
+	if ((error = git_reference__log_signature(&who, ref->db->repo)) < 0)
+		return error;
+
+	error = reference__rename(out, ref, new_name, force, who, log_message);
+	git_signature_free(who);
+
+	return error;
+}
+
+int git_reference_resolve(git_reference **ref_out, const git_reference *ref)
+{
+	switch (git_reference_type(ref)) {
+	case GIT_REF_OID:
+		return git_reference_lookup(ref_out, ref->db->repo, ref->name);
+
+	case GIT_REF_SYMBOLIC:
+		return git_reference_lookup_resolved(ref_out, ref->db->repo, ref->target.symbolic, -1);
+
+	default:
+		giterr_set(GITERR_REFERENCE, "invalid reference");
+		return -1;
+	}
+}
+
+int git_reference_foreach(
+	git_repository *repo,
+	git_reference_foreach_cb callback,
+	void *payload)
+{
+	git_reference_iterator *iter;
+	git_reference *ref;
+	int error;
+
+	if ((error = git_reference_iterator_new(&iter, repo)) < 0)
+		return error;
+
+	while (!(error = git_reference_next(&ref, iter))) {
+		if ((error = callback(ref, payload)) != 0) {
+			giterr_set_after_callback(error);
+			break;
+		}
+	}
+
+	if (error == GIT_ITEROVER)
+		error = 0;
+
+	git_reference_iterator_free(iter);
+	return error;
+}
+
+int git_reference_foreach_name(
+	git_repository *repo,
+	git_reference_foreach_name_cb callback,
+	void *payload)
+{
+	git_reference_iterator *iter;
+	const char *refname;
+	int error;
+
+	if ((error = git_reference_iterator_new(&iter, repo)) < 0)
+		return error;
+
+	while (!(error = git_reference_next_name(&refname, iter))) {
+		if ((error = callback(refname, payload)) != 0) {
+			giterr_set_after_callback(error);
+			break;
+		}
+	}
+
+	if (error == GIT_ITEROVER)
+		error = 0;
+
+	git_reference_iterator_free(iter);
+	return error;
+}
+
+int git_reference_foreach_glob(
+	git_repository *repo,
+	const char *glob,
+	git_reference_foreach_name_cb callback,
+	void *payload)
+{
+	git_reference_iterator *iter;
+	const char *refname;
+	int error;
+
+	if ((error = git_reference_iterator_glob_new(&iter, repo, glob)) < 0)
+		return error;
+
+	while (!(error = git_reference_next_name(&refname, iter))) {
+		if ((error = callback(refname, payload)) != 0) {
+			giterr_set_after_callback(error);
+			break;
+		}
+	}
+
+	if (error == GIT_ITEROVER)
+		error = 0;
+
+	git_reference_iterator_free(iter);
+	return error;
+}
+
+int git_reference_iterator_new(git_reference_iterator **out, git_repository *repo)
+{
+	git_refdb *refdb;
+
+	if (git_repository_refdb__weakptr(&refdb, repo) < 0)
+		return -1;
+
+	return git_refdb_iterator(out, refdb, NULL);
+}
+
+int git_reference_iterator_glob_new(
+	git_reference_iterator **out, git_repository *repo, const char *glob)
+{
+	git_refdb *refdb;
+
+	if (git_repository_refdb__weakptr(&refdb, repo) < 0)
+		return -1;
+
+	return git_refdb_iterator(out, refdb, glob);
+}
+
+int git_reference_next(git_reference **out, git_reference_iterator *iter)
+{
+	return git_refdb_iterator_next(out, iter);
+}
+
+int git_reference_next_name(const char **out, git_reference_iterator *iter)
+{
+	return git_refdb_iterator_next_name(out, iter);
+}
+
+void git_reference_iterator_free(git_reference_iterator *iter)
+{
+	if (iter == NULL)
+		return;
+
+	git_refdb_iterator_free(iter);
+}
+
+static int cb__reflist_add(const char *ref, void *data)
+{
+	char *name = git__strdup(ref);
+	GITERR_CHECK_ALLOC(name);
+	return git_vector_insert((git_vector *)data, name);
+}
+
+int git_reference_list(
+	git_strarray *array,
+	git_repository *repo)
+{
+	git_vector ref_list;
+
+	assert(array && repo);
+
+	array->strings = NULL;
+	array->count = 0;
+
+	if (git_vector_init(&ref_list, 8, NULL) < 0)
+		return -1;
+
+	if (git_reference_foreach_name(
+			repo, &cb__reflist_add, (void *)&ref_list) < 0) {
+		git_vector_free(&ref_list);
+		return -1;
+	}
+
+	array->strings = (char **)git_vector_detach(&array->count, NULL, &ref_list);
+
+	return 0;
+}
+
+static int is_valid_ref_char(char ch)
+{
+	if ((unsigned) ch <= ' ')
+		return 0;
+
+	switch (ch) {
+	case '~':
+	case '^':
+	case ':':
+	case '\\':
+	case '?':
+	case '[':
+	case '*':
+		return 0;
+	default:
+		return 1;
+	}
+}
+
+static int ensure_segment_validity(const char *name)
+{
+	const char *current = name;
+	char prev = '\0';
+	const int lock_len = (int)strlen(GIT_FILELOCK_EXTENSION);
+	int segment_len;
+
+	if (*current == '.')
+		return -1; /* Refname starts with "." */
+
+	for (current = name; ; current++) {
+		if (*current == '\0' || *current == '/')
+			break;
+
+		if (!is_valid_ref_char(*current))
+			return -1; /* Illegal character in refname */
+
+		if (prev == '.' && *current == '.')
+			return -1; /* Refname contains ".." */
+
+		if (prev == '@' && *current == '{')
+			return -1; /* Refname contains "@{" */
+
+		prev = *current;
+	}
+
+	segment_len = (int)(current - name);
+
+	/* A refname component can not end with ".lock" */
+	if (segment_len >= lock_len &&
+		!memcmp(current - lock_len, GIT_FILELOCK_EXTENSION, lock_len))
+			return -1;
+
+	return segment_len;
+}
+
+static bool is_all_caps_and_underscore(const char *name, size_t len)
+{
+	size_t i;
+	char c;
+
+	assert(name && len > 0);
+
+	for (i = 0; i < len; i++)
+	{
+		c = name[i];
+		if ((c < 'A' || c > 'Z') && c != '_')
+			return false;
+	}
+
+	if (*name == '_' || name[len - 1] == '_')
+		return false;
+
+	return true;
+}
+
+/* Inspired from https://github.com/git/git/blob/f06d47e7e0d9db709ee204ed13a8a7486149f494/refs.c#L36-100 */
+int git_reference__normalize_name(
+	git_buf *buf,
+	const char *name,
+	unsigned int flags)
+{
+	const char *current;
+	int segment_len, segments_count = 0, error = GIT_EINVALIDSPEC;
+	unsigned int process_flags;
+	bool normalize = (buf != NULL);
+	bool validate = (flags & GIT_REF_FORMAT__VALIDATION_DISABLE) == 0;
+
+#ifdef GIT_USE_ICONV
+	git_path_iconv_t ic = GIT_PATH_ICONV_INIT;
+#endif
+
+	assert(name);
+
+	process_flags = flags;
+	current = (char *)name;
+
+	if (validate && *current == '/')
+		goto cleanup;
+
+	if (normalize)
+		git_buf_clear(buf);
+
+#ifdef GIT_USE_ICONV
+	if ((flags & GIT_REF_FORMAT__PRECOMPOSE_UNICODE) != 0) {
+		size_t namelen = strlen(current);
+		if ((error = git_path_iconv_init_precompose(&ic)) < 0 ||
+			(error = git_path_iconv(&ic, &current, &namelen)) < 0)
+			goto cleanup;
+		error = GIT_EINVALIDSPEC;
+	}
+#endif
+
+	if (!validate) {
+		git_buf_sets(buf, current);
+
+		error = git_buf_oom(buf) ? -1 : 0;
+		goto cleanup;
+	}
+
+	while (true) {
+		segment_len = ensure_segment_validity(current);
+		if (segment_len < 0) {
+			if ((process_flags & GIT_REF_FORMAT_REFSPEC_PATTERN) &&
+					current[0] == '*' &&
+					(current[1] == '\0' || current[1] == '/')) {
+				/* Accept one wildcard as a full refname component. */
+				process_flags &= ~GIT_REF_FORMAT_REFSPEC_PATTERN;
+				segment_len = 1;
+			} else
+				goto cleanup;
+		}
+
+		if (segment_len > 0) {
+			if (normalize) {
+				size_t cur_len = git_buf_len(buf);
+
+				git_buf_joinpath(buf, git_buf_cstr(buf), current);
+				git_buf_truncate(buf,
+					cur_len + segment_len + (segments_count ? 1 : 0));
+
+				if (git_buf_oom(buf)) {
+					error = -1;
+					goto cleanup;
+				}
+			}
+
+			segments_count++;
+		}
+
+		/* No empty segment is allowed when not normalizing */
+		if (segment_len == 0 && !normalize)
+			goto cleanup;
+
+		if (current[segment_len] == '\0')
+			break;
+
+		current += segment_len + 1;
+	}
+
+	/* A refname can not be empty */
+	if (segment_len == 0 && segments_count == 0)
+		goto cleanup;
+
+	/* A refname can not end with "." */
+	if (current[segment_len - 1] == '.')
+		goto cleanup;
+
+	/* A refname can not end with "/" */
+	if (current[segment_len - 1] == '/')
+		goto cleanup;
+
+	if ((segments_count == 1 ) && !(flags & GIT_REF_FORMAT_ALLOW_ONELEVEL))
+		goto cleanup;
+
+	if ((segments_count == 1 ) &&
+	    !(flags & GIT_REF_FORMAT_REFSPEC_SHORTHAND) &&
+		!(is_all_caps_and_underscore(name, (size_t)segment_len) ||
+			((flags & GIT_REF_FORMAT_REFSPEC_PATTERN) && !strcmp("*", name))))
+			goto cleanup;
+
+	if ((segments_count > 1)
+		&& (is_all_caps_and_underscore(name, strchr(name, '/') - name)))
+			goto cleanup;
+
+	error = 0;
+
+cleanup:
+	if (error == GIT_EINVALIDSPEC)
+		giterr_set(
+			GITERR_REFERENCE,
+			"the given reference name '%s' is not valid", name);
+
+	if (error && normalize)
+		git_buf_free(buf);
+
+#ifdef GIT_USE_ICONV
+	git_path_iconv_clear(&ic);
+#endif
+
+	return error;
+}
+
+int git_reference_normalize_name(
+	char *buffer_out,
+	size_t buffer_size,
+	const char *name,
+	unsigned int flags)
+{
+	git_buf buf = GIT_BUF_INIT;
+	int error;
+
+	if ((error = git_reference__normalize_name(&buf, name, flags)) < 0)
+		goto cleanup;
+
+	if (git_buf_len(&buf) > buffer_size - 1) {
+		giterr_set(
+		GITERR_REFERENCE,
+		"the provided buffer is too short to hold the normalization of '%s'", name);
+		error = GIT_EBUFS;
+		goto cleanup;
+	}
+
+	git_buf_copy_cstr(buffer_out, buffer_size, &buf);
+
+	error = 0;
+
+cleanup:
+	git_buf_free(&buf);
+	return error;
+}
+
+#define GIT_REF_TYPEMASK (GIT_REF_OID | GIT_REF_SYMBOLIC)
+
+int git_reference_cmp(
+	const git_reference *ref1,
+	const git_reference *ref2)
+{
+	git_ref_t type1, type2;
+	assert(ref1 && ref2);
+
+	type1 = git_reference_type(ref1);
+	type2 = git_reference_type(ref2);
+
+	/* let's put symbolic refs before OIDs */
+	if (type1 != type2)
+		return (type1 == GIT_REF_SYMBOLIC) ? -1 : 1;
+
+	if (type1 == GIT_REF_SYMBOLIC)
+		return strcmp(ref1->target.symbolic, ref2->target.symbolic);
+
+	return git_oid__cmp(&ref1->target.oid, &ref2->target.oid);
+}
+
+/**
+ * Get the end of a chain of references. If the final one is not
+ * found, we return the reference just before that.
+ */
+static int get_terminal(git_reference **out, git_repository *repo, const char *ref_name, int nesting)
+{
+	git_reference *ref;
+	int error = 0;
+
+	if (nesting > MAX_NESTING_LEVEL) {
+		giterr_set(GITERR_REFERENCE, "reference chain too deep (%d)", nesting);
+		return GIT_ENOTFOUND;
+	}
+
+	/* set to NULL to let the caller know that they're at the end of the chain */
+	if ((error = git_reference_lookup(&ref, repo, ref_name)) < 0) {
+		*out = NULL;
+		return error;
+	}
+
+	if (git_reference_type(ref) == GIT_REF_OID) {
+		*out = ref;
+		error = 0;
+	} else {
+		error = get_terminal(out, repo, git_reference_symbolic_target(ref), nesting + 1);
+		if (error == GIT_ENOTFOUND && !*out)
+			*out = ref;
+		else
+			git_reference_free(ref);
+	}
+
+	return error;
+}
+
+/*
+ * Starting with the reference given by `ref_name`, follows symbolic
+ * references until a direct reference is found and updated the OID
+ * on that direct reference to `oid`.
+ */
+int git_reference__update_terminal(
+	git_repository *repo,
+	const char *ref_name,
+	const git_oid *oid,
+	const git_signature *sig,
+	const char *log_message)
+{
+	git_reference *ref = NULL, *ref2 = NULL;
+	git_signature *who = NULL;
+	const git_signature *to_use;
+	int error = 0;
+
+	if (!sig && (error = git_reference__log_signature(&who, repo)) < 0)
+		return error;
+
+	to_use = sig ? sig : who;
+	error = get_terminal(&ref, repo, ref_name, 0);
+
+	/* found a dangling symref */
+	if (error == GIT_ENOTFOUND && ref) {
+		assert(git_reference_type(ref) == GIT_REF_SYMBOLIC);
+		giterr_clear();
+		error = reference__create(&ref2, repo, ref->target.symbolic, oid, NULL, 0, to_use,
+					  log_message, NULL, NULL);
+	} else if (error == GIT_ENOTFOUND) {
+		giterr_clear();
+		error = reference__create(&ref2, repo, ref_name, oid, NULL, 0, to_use,
+					  log_message, NULL, NULL);
+	}  else if (error == 0) {
+		assert(git_reference_type(ref) == GIT_REF_OID);
+		error = reference__create(&ref2, repo, ref->name, oid, NULL, 1, to_use,
+					  log_message, &ref->target.oid, NULL);
+	}
+
+	git_reference_free(ref2);
+	git_reference_free(ref);
+	git_signature_free(who);
+	return error;
+}
+
+static const char *commit_type(const git_commit *commit)
+{
+	unsigned int count = git_commit_parentcount(commit);
+
+	if (count >= 2)
+		return " (merge)";
+	else if (count == 0)
+		return " (initial)";
+	else
+		return "";
+}
+
+int git_reference__update_for_commit(
+	git_repository *repo,
+	git_reference *ref,
+	const char *ref_name,
+	const git_oid *id,
+	const char *operation)
+{
+	git_reference *ref_new = NULL;
+	git_commit *commit = NULL;
+	git_buf reflog_msg = GIT_BUF_INIT;
+	const git_signature *who;
+	int error;
+
+	if ((error = git_commit_lookup(&commit, repo, id)) < 0 ||
+		(error = git_buf_printf(&reflog_msg, "%s%s: %s",
+			operation ? operation : "commit",
+			commit_type(commit),
+			git_commit_summary(commit))) < 0)
+		goto done;
+
+	who = git_commit_committer(commit);
+
+	if (ref) {
+		if ((error = ensure_is_an_updatable_direct_reference(ref)) < 0)
+			return error;
+
+		error = reference__create(&ref_new, repo, ref->name, id, NULL, 1, who,
+					  git_buf_cstr(&reflog_msg), &ref->target.oid, NULL);
+	}
+	else
+		error = git_reference__update_terminal(
+			repo, ref_name, id, who, git_buf_cstr(&reflog_msg));
+
+done:
+	git_reference_free(ref_new);
+	git_buf_free(&reflog_msg);
+	git_commit_free(commit);
+	return error;
+}
+
+int git_reference_has_log(git_repository *repo, const char *refname)
+{
+	int error;
+	git_refdb *refdb;
+
+	assert(repo && refname);
+
+	if ((error = git_repository_refdb__weakptr(&refdb, repo)) < 0)
+		return error;
+
+	return git_refdb_has_log(refdb, refname);
+}
+
+int git_reference_ensure_log(git_repository *repo, const char *refname)
+{
+	int error;
+	git_refdb *refdb;
+
+	assert(repo && refname);
+
+	if ((error = git_repository_refdb__weakptr(&refdb, repo)) < 0)
+		return error;
+
+	return git_refdb_ensure_log(refdb, refname);
+}
+
+int git_reference__is_branch(const char *ref_name)
+{
+	return git__prefixcmp(ref_name, GIT_REFS_HEADS_DIR) == 0;
+}
+
+int git_reference_is_branch(const git_reference *ref)
+{
+	assert(ref);
+	return git_reference__is_branch(ref->name);
+}
+
+int git_reference__is_remote(const char *ref_name)
+{
+	return git__prefixcmp(ref_name, GIT_REFS_REMOTES_DIR) == 0;
+}
+
+int git_reference_is_remote(const git_reference *ref)
+{
+	assert(ref);
+	return git_reference__is_remote(ref->name);
+}
+
+int git_reference__is_tag(const char *ref_name)
+{
+	return git__prefixcmp(ref_name, GIT_REFS_TAGS_DIR) == 0;
+}
+
+int git_reference_is_tag(const git_reference *ref)
+{
+	assert(ref);
+	return git_reference__is_tag(ref->name);
+}
+
+int git_reference__is_note(const char *ref_name)
+{
+	return git__prefixcmp(ref_name, GIT_REFS_NOTES_DIR) == 0;
+}
+
+int git_reference_is_note(const git_reference *ref)
+{
+	assert(ref);
+	return git_reference__is_note(ref->name);
+}
+
+static int peel_error(int error, git_reference *ref, const char* msg)
+{
+	giterr_set(
+		GITERR_INVALID,
+		"the reference '%s' cannot be peeled - %s", git_reference_name(ref), msg);
+	return error;
+}
+
+int git_reference_peel(
+	git_object **peeled,
+	git_reference *ref,
+	git_otype target_type)
+{
+	git_reference *resolved = NULL;
+	git_object *target = NULL;
+	int error;
+
+	assert(ref);
+
+	if (ref->type == GIT_REF_OID) {
+		resolved = ref;
+	} else {
+		if ((error = git_reference_resolve(&resolved, ref)) < 0)
+			return peel_error(error, ref, "Cannot resolve reference");
+	}
+
+	/*
+	 * If we try to peel an object to a tag, we cannot use
+	 * the fully peeled object, as that will always resolve
+	 * to a commit. So we only want to use the peeled value
+	 * if it is not zero and the target is not a tag.
+	 */
+	if (target_type != GIT_OBJ_TAG && !git_oid_iszero(&resolved->peel)) {
+		error = git_object_lookup(&target,
+			git_reference_owner(ref), &resolved->peel, GIT_OBJ_ANY);
+	} else {
+		error = git_object_lookup(&target,
+			git_reference_owner(ref), &resolved->target.oid, GIT_OBJ_ANY);
+	}
+
+	if (error < 0) {
+		peel_error(error, ref, "Cannot retrieve reference target");
+		goto cleanup;
+	}
+
+	if (target_type == GIT_OBJ_ANY && git_object_type(target) != GIT_OBJ_TAG)
+		error = git_object_dup(peeled, target);
+	else
+		error = git_object_peel(peeled, target, target_type);
+
+cleanup:
+	git_object_free(target);
+
+	if (resolved != ref)
+		git_reference_free(resolved);
+
+	return error;
+}
+
+int git_reference__is_valid_name(const char *refname, unsigned int flags)
+{
+	if (git_reference__normalize_name(NULL, refname, flags) < 0) {
+		giterr_clear();
+		return false;
+	}
+
+	return true;
+}
+
+int git_reference_is_valid_name(const char *refname)
+{
+	return git_reference__is_valid_name(refname, GIT_REF_FORMAT_ALLOW_ONELEVEL);
+}
+
+const char *git_reference__shorthand(const char *name)
+{
+	if (!git__prefixcmp(name, GIT_REFS_HEADS_DIR))
+		return name + strlen(GIT_REFS_HEADS_DIR);
+	else if (!git__prefixcmp(name, GIT_REFS_TAGS_DIR))
+		return name + strlen(GIT_REFS_TAGS_DIR);
+	else if (!git__prefixcmp(name, GIT_REFS_REMOTES_DIR))
+		return name + strlen(GIT_REFS_REMOTES_DIR);
+	else if (!git__prefixcmp(name, GIT_REFS_DIR))
+		return name + strlen(GIT_REFS_DIR);
+
+	/* No shorthands are avaiable, so just return the name */
+	return name;
+}
+
+const char *git_reference_shorthand(const git_reference *ref)
+{
+	return git_reference__shorthand(ref->name);
+}

vendor/libgit2-sys/libgit2/src/refs.h

diff --git a/vendor/libgit2-sys/libgit2/src/refs.h b/vendor/libgit2-sys/libgit2/src/refs.h
new file mode 100644
index 0000000..84daf8b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/refs.h
@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_refs_h__
+#define INCLUDE_refs_h__
+
+#include "common.h"
+
+#include "git2/oid.h"
+#include "git2/refs.h"
+#include "git2/refdb.h"
+#include "strmap.h"
+#include "buffer.h"
+#include "oid.h"
+
+extern bool git_reference__enable_symbolic_ref_target_validation;
+
+#define GIT_REFS_DIR "refs/"
+#define GIT_REFS_HEADS_DIR GIT_REFS_DIR "heads/"
+#define GIT_REFS_TAGS_DIR GIT_REFS_DIR "tags/"
+#define GIT_REFS_REMOTES_DIR GIT_REFS_DIR "remotes/"
+#define GIT_REFS_NOTES_DIR GIT_REFS_DIR "notes/"
+#define GIT_REFS_DIR_MODE 0777
+#define GIT_REFS_FILE_MODE 0666
+
+#define GIT_RENAMED_REF_FILE GIT_REFS_DIR "RENAMED-REF"
+
+#define GIT_SYMREF "ref: "
+#define GIT_PACKEDREFS_FILE "packed-refs"
+#define GIT_PACKEDREFS_HEADER "# pack-refs with: peeled fully-peeled sorted "
+#define GIT_PACKEDREFS_FILE_MODE 0666
+
+#define GIT_HEAD_FILE "HEAD"
+#define GIT_ORIG_HEAD_FILE "ORIG_HEAD"
+#define GIT_FETCH_HEAD_FILE "FETCH_HEAD"
+#define GIT_MERGE_HEAD_FILE "MERGE_HEAD"
+#define GIT_REVERT_HEAD_FILE "REVERT_HEAD"
+#define GIT_CHERRYPICK_HEAD_FILE "CHERRY_PICK_HEAD"
+#define GIT_BISECT_LOG_FILE "BISECT_LOG"
+#define GIT_REBASE_MERGE_DIR "rebase-merge/"
+#define GIT_REBASE_MERGE_INTERACTIVE_FILE GIT_REBASE_MERGE_DIR "interactive"
+#define GIT_REBASE_APPLY_DIR "rebase-apply/"
+#define GIT_REBASE_APPLY_REBASING_FILE GIT_REBASE_APPLY_DIR "rebasing"
+#define GIT_REBASE_APPLY_APPLYING_FILE GIT_REBASE_APPLY_DIR "applying"
+#define GIT_REFS_HEADS_MASTER_FILE GIT_REFS_HEADS_DIR "master"
+
+#define GIT_SEQUENCER_DIR "sequencer/"
+#define GIT_SEQUENCER_HEAD_FILE GIT_SEQUENCER_DIR "head"
+#define GIT_SEQUENCER_OPTIONS_FILE GIT_SEQUENCER_DIR "options"
+#define GIT_SEQUENCER_TODO_FILE GIT_SEQUENCER_DIR "todo"
+
+#define GIT_STASH_FILE "stash"
+#define GIT_REFS_STASH_FILE GIT_REFS_DIR GIT_STASH_FILE
+
+#define GIT_REF_FORMAT__PRECOMPOSE_UNICODE	(1u << 16)
+#define GIT_REF_FORMAT__VALIDATION_DISABLE	(1u << 15)
+
+#define GIT_REFNAME_MAX 1024
+
+typedef char git_refname_t[GIT_REFNAME_MAX];
+
+struct git_reference {
+	git_refdb *db;
+	git_ref_t type;
+
+	union {
+		git_oid oid;
+		char *symbolic;
+	} target;
+
+	git_oid peel;
+	char name[GIT_FLEX_ARRAY];
+};
+
+git_reference *git_reference__set_name(git_reference *ref, const char *name);
+
+int git_reference__normalize_name(git_buf *buf, const char *name, unsigned int flags);
+int git_reference__update_terminal(git_repository *repo, const char *ref_name, const git_oid *oid, const git_signature *sig, const char *log_message);
+int git_reference__is_valid_name(const char *refname, unsigned int flags);
+int git_reference__is_branch(const char *ref_name);
+int git_reference__is_remote(const char *ref_name);
+int git_reference__is_tag(const char *ref_name);
+const char *git_reference__shorthand(const char *name);
+
+/**
+ * Lookup a reference by name and try to resolve to an OID.
+ *
+ * You can control how many dereferences this will attempt to resolve the
+ * reference with the `max_deref` parameter, or pass -1 to use a sane
+ * default.  If you pass 0 for `max_deref`, this will not attempt to resolve
+ * the reference.  For any value of `max_deref` other than 0, not
+ * successfully resolving the reference will be reported as an error.
+
+ * The generated reference must be freed by the user.
+ *
+ * @param reference_out Pointer to the looked-up reference
+ * @param repo The repository to look up the reference
+ * @param name The long name for the reference (e.g. HEAD, ref/heads/master, refs/tags/v0.1.0, ...)
+ * @param max_deref Maximum number of dereferences to make of symbolic refs, 0 means simple lookup, < 0 means use default reasonable value
+ * @return 0 on success or < 0 on error; not being able to resolve the reference is an error unless 0 was passed for max_deref
+ */
+int git_reference_lookup_resolved(
+	git_reference **reference_out,
+	git_repository *repo,
+	const char *name,
+	int max_deref);
+
+/**
+ * Read reference from a file.
+ *
+ * This function will read in the file at `path`. If it is a
+ * symref, it will return a new unresolved symbolic reference
+ * with the given name pointing to the reference pointed to by
+ * the file. If it is not a symbolic reference, it will return
+ * the resolved reference.
+ *
+ * Note that because the refdb is not involved for symbolic references, they
+ * won't be owned, hence you should either not make the returned reference
+ * 'externally visible', or perform the lookup before returning it to the user.
+ */
+int git_reference__read_head(
+	git_reference **out,
+	git_repository *repo,
+	const char *path);
+
+int git_reference__log_signature(git_signature **out, git_repository *repo);
+
+/** Update a reference after a commit. */
+int git_reference__update_for_commit(
+	git_repository *repo,
+	git_reference *ref,
+	const char *ref_name,
+	const git_oid *id,
+	const char *operation);
+
+#endif

vendor/libgit2-sys/libgit2/src/refspec.c

diff --git a/vendor/libgit2-sys/libgit2/src/refspec.c b/vendor/libgit2-sys/libgit2/src/refspec.c
new file mode 100644
index 0000000..943a9c7
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/refspec.c
@@ -0,0 +1,370 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "refspec.h"
+
+#include "git2/errors.h"
+
+#include "util.h"
+#include "posix.h"
+#include "refs.h"
+#include "vector.h"
+
+int git_refspec__parse(git_refspec *refspec, const char *input, bool is_fetch)
+{
+	// Ported from https://github.com/git/git/blob/f06d47e7e0d9db709ee204ed13a8a7486149f494/remote.c#L518-636
+
+	size_t llen;
+	int is_glob = 0;
+	const char *lhs, *rhs;
+	int flags;
+
+	assert(refspec && input);
+
+	memset(refspec, 0x0, sizeof(git_refspec));
+	refspec->push = !is_fetch;
+
+	lhs = input;
+	if (*lhs == '+') {
+		refspec->force = 1;
+		lhs++;
+	}
+
+	rhs = strrchr(lhs, ':');
+
+	/*
+	 * Before going on, special case ":" (or "+:") as a refspec
+	 * for matching refs.
+	 */
+	if (!is_fetch && rhs == lhs && rhs[1] == '\0') {
+		refspec->matching = 1;
+		refspec->string = git__strdup(input);
+		GITERR_CHECK_ALLOC(refspec->string);
+		refspec->src = git__strdup("");
+		GITERR_CHECK_ALLOC(refspec->src);
+		refspec->dst = git__strdup("");
+		GITERR_CHECK_ALLOC(refspec->dst);
+		return 0;
+	}
+
+	if (rhs) {
+		size_t rlen = strlen(++rhs);
+		if (rlen || !is_fetch) {
+			is_glob = (1 <= rlen && strchr(rhs, '*'));
+			refspec->dst = git__strndup(rhs, rlen);
+		}
+	}
+
+	llen = (rhs ? (size_t)(rhs - lhs - 1) : strlen(lhs));
+	if (1 <= llen && memchr(lhs, '*', llen)) {
+		if ((rhs && !is_glob) || (!rhs && is_fetch))
+			goto invalid;
+		is_glob = 1;
+	} else if (rhs && is_glob)
+		goto invalid;
+
+	refspec->pattern = is_glob;
+	refspec->src = git__strndup(lhs, llen);
+	flags = GIT_REF_FORMAT_ALLOW_ONELEVEL | GIT_REF_FORMAT_REFSPEC_SHORTHAND
+		| (is_glob ? GIT_REF_FORMAT_REFSPEC_PATTERN : 0);
+
+	if (is_fetch) {
+		/*
+			* LHS
+			* - empty is allowed; it means HEAD.
+			* - otherwise it must be a valid looking ref.
+			*/
+		if (!*refspec->src)
+			; /* empty is ok */
+		else if (!git_reference__is_valid_name(refspec->src, flags))
+			goto invalid;
+		/*
+			* RHS
+			* - missing is ok, and is same as empty.
+			* - empty is ok; it means not to store.
+			* - otherwise it must be a valid looking ref.
+			*/
+		if (!refspec->dst)
+			; /* ok */
+		else if (!*refspec->dst)
+			; /* ok */
+		else if (!git_reference__is_valid_name(refspec->dst, flags))
+			goto invalid;
+	} else {
+		/*
+			* LHS
+			* - empty is allowed; it means delete.
+			* - when wildcarded, it must be a valid looking ref.
+			* - otherwise, it must be an extended SHA-1, but
+			*   there is no existing way to validate this.
+			*/
+		if (!*refspec->src)
+			; /* empty is ok */
+		else if (is_glob) {
+			if (!git_reference__is_valid_name(refspec->src, flags))
+				goto invalid;
+		}
+		else {
+			; /* anything goes, for now */
+		}
+		/*
+			* RHS
+			* - missing is allowed, but LHS then must be a
+			*   valid looking ref.
+			* - empty is not allowed.
+			* - otherwise it must be a valid looking ref.
+			*/
+		if (!refspec->dst) {
+			if (!git_reference__is_valid_name(refspec->src, flags))
+				goto invalid;
+		} else if (!*refspec->dst) {
+			goto invalid;
+		} else {
+			if (!git_reference__is_valid_name(refspec->dst, flags))
+				goto invalid;
+		}
+
+		/* if the RHS is empty, then it's a copy of the LHS */
+		if (!refspec->dst) {
+			refspec->dst = git__strdup(refspec->src);
+			GITERR_CHECK_ALLOC(refspec->dst);
+		}
+	}
+
+	refspec->string = git__strdup(input);
+	GITERR_CHECK_ALLOC(refspec->string);
+
+	return 0;
+
+ invalid:
+        giterr_set(
+                GITERR_INVALID,
+                "'%s' is not a valid refspec.", input);
+        git_refspec__free(refspec);
+	return -1;
+}
+
+void git_refspec__free(git_refspec *refspec)
+{
+	if (refspec == NULL)
+		return;
+
+	git__free(refspec->src);
+	git__free(refspec->dst);
+	git__free(refspec->string);
+
+	memset(refspec, 0x0, sizeof(git_refspec));
+}
+
+const char *git_refspec_src(const git_refspec *refspec)
+{
+	return refspec == NULL ? NULL : refspec->src;
+}
+
+const char *git_refspec_dst(const git_refspec *refspec)
+{
+	return refspec == NULL ? NULL : refspec->dst;
+}
+
+const char *git_refspec_string(const git_refspec *refspec)
+{
+	return refspec == NULL ? NULL : refspec->string;
+}
+
+int git_refspec_force(const git_refspec *refspec)
+{
+	assert(refspec);
+
+	return refspec->force;
+}
+
+int git_refspec_src_matches(const git_refspec *refspec, const char *refname)
+{
+	if (refspec == NULL || refspec->src == NULL)
+		return false;
+
+	return (p_fnmatch(refspec->src, refname, 0) == 0);
+}
+
+int git_refspec_dst_matches(const git_refspec *refspec, const char *refname)
+{
+	if (refspec == NULL || refspec->dst == NULL)
+		return false;
+
+	return (p_fnmatch(refspec->dst, refname, 0) == 0);
+}
+
+static int refspec_transform(
+	git_buf *out, const char *from, const char *to, const char *name)
+{
+	const char *from_star, *to_star;
+	const char *name_slash, *from_slash;
+	size_t replacement_len, star_offset;
+
+	git_buf_sanitize(out);
+	git_buf_clear(out);
+
+	/*
+	 * There are two parts to each side of a refspec, the bit
+	 * before the star and the bit after it. The star can be in
+	 * the middle of the pattern, so we need to look at each bit
+	 * individually.
+	 */
+	from_star = strchr(from, '*');
+	to_star = strchr(to, '*');
+
+	assert(from_star && to_star);
+
+	/* star offset, both in 'from' and in 'name' */
+	star_offset = from_star - from;
+
+	/* the first half is copied over */
+	git_buf_put(out, to, to_star - to);
+
+	/* then we copy over the replacement, from the star's offset to the next slash in 'name' */
+	name_slash = strchr(name + star_offset, '/');
+	if (!name_slash)
+		name_slash = strrchr(name, '\0');
+
+	/* if there is no slash after the star in 'from', we want to copy everything over */
+	from_slash = strchr(from + star_offset, '/');
+	if (!from_slash)
+		name_slash = strrchr(name, '\0');
+
+	replacement_len = (name_slash - name) - star_offset;
+	git_buf_put(out, name + star_offset, replacement_len);
+
+	return git_buf_puts(out, to_star + 1);
+}
+
+int git_refspec_transform(git_buf *out, const git_refspec *spec, const char *name)
+{
+	assert(out && spec && name);
+	git_buf_sanitize(out);
+
+	if (!git_refspec_src_matches(spec, name)) {
+		giterr_set(GITERR_INVALID, "ref '%s' doesn't match the source", name);
+		return -1;
+	}
+
+	if (!spec->pattern)
+		return git_buf_puts(out, spec->dst);
+
+	return refspec_transform(out, spec->src, spec->dst, name);
+}
+
+int git_refspec_rtransform(git_buf *out, const git_refspec *spec, const char *name)
+{
+	assert(out && spec && name);
+	git_buf_sanitize(out);
+
+	if (!git_refspec_dst_matches(spec, name)) {
+		giterr_set(GITERR_INVALID, "ref '%s' doesn't match the destination", name);
+		return -1;
+	}
+
+	if (!spec->pattern)
+		return git_buf_puts(out, spec->src);
+
+	return refspec_transform(out, spec->dst, spec->src, name);
+}
+
+int git_refspec__serialize(git_buf *out, const git_refspec *refspec)
+{
+	if (refspec->force)
+		git_buf_putc(out, '+');
+
+	git_buf_printf(out, "%s:%s",
+		refspec->src != NULL ? refspec->src : "",
+		refspec->dst != NULL ? refspec->dst : "");
+
+	return git_buf_oom(out) == false;
+}
+
+int git_refspec_is_wildcard(const git_refspec *spec)
+{
+	assert(spec && spec->src);
+
+	return (spec->src[strlen(spec->src) - 1] == '*');
+}
+
+git_direction git_refspec_direction(const git_refspec *spec)
+{
+	assert(spec);
+
+	return spec->push;
+}
+
+int git_refspec__dwim_one(git_vector *out, git_refspec *spec, git_vector *refs)
+{
+	git_buf buf = GIT_BUF_INIT;
+	size_t j, pos;
+	git_remote_head key;
+	git_refspec *cur;
+
+	const char* formatters[] = {
+		GIT_REFS_DIR "%s",
+		GIT_REFS_TAGS_DIR "%s",
+		GIT_REFS_HEADS_DIR "%s",
+		NULL
+	};
+
+	assert(out && spec && refs);
+
+	cur = git__calloc(1, sizeof(git_refspec));
+	GITERR_CHECK_ALLOC(cur);
+
+	cur->force = spec->force;
+	cur->push = spec->push;
+	cur->pattern = spec->pattern;
+	cur->matching = spec->matching;
+	cur->string = git__strdup(spec->string);
+
+	/* shorthand on the lhs */
+	if (git__prefixcmp(spec->src, GIT_REFS_DIR)) {
+		for (j = 0; formatters[j]; j++) {
+			git_buf_clear(&buf);
+			git_buf_printf(&buf, formatters[j], spec->src);
+			GITERR_CHECK_ALLOC_BUF(&buf);
+
+			key.name = (char *) git_buf_cstr(&buf);
+			if (!git_vector_search(&pos, refs, &key)) {
+				/* we found something to match the shorthand, set src to that */
+				cur->src = git_buf_detach(&buf);
+			}
+		}
+	}
+
+	/* No shorthands found, copy over the name */
+	if (cur->src == NULL && spec->src != NULL) {
+		cur->src = git__strdup(spec->src);
+		GITERR_CHECK_ALLOC(cur->src);
+	}
+
+	if (spec->dst && git__prefixcmp(spec->dst, GIT_REFS_DIR)) {
+		/* if it starts with "remotes" then we just prepend "refs/" */
+		if (!git__prefixcmp(spec->dst, "remotes/")) {
+			git_buf_puts(&buf, GIT_REFS_DIR);
+		} else {
+			git_buf_puts(&buf, GIT_REFS_HEADS_DIR);
+		}
+
+		git_buf_puts(&buf, spec->dst);
+		GITERR_CHECK_ALLOC_BUF(&buf);
+
+		cur->dst = git_buf_detach(&buf);
+	}
+
+	git_buf_free(&buf);
+
+	if (cur->dst == NULL && spec->dst != NULL) {
+		cur->dst = git__strdup(spec->dst);
+		GITERR_CHECK_ALLOC(cur->dst);
+	}
+
+	return git_vector_insert(out, cur);
+}

vendor/libgit2-sys/libgit2/src/refspec.h

diff --git a/vendor/libgit2-sys/libgit2/src/refspec.h b/vendor/libgit2-sys/libgit2/src/refspec.h
new file mode 100644
index 0000000..fd2d8b3
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/refspec.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_refspec_h__
+#define INCLUDE_refspec_h__
+
+#include "common.h"
+
+#include "git2/refspec.h"
+#include "buffer.h"
+#include "vector.h"
+
+struct git_refspec {
+	char *string;
+	char *src;
+	char *dst;
+	unsigned int force :1,
+		push : 1,
+		pattern :1,
+		matching :1;
+};
+
+#define GIT_REFSPEC_TAGS "refs/tags/*:refs/tags/*"
+
+int git_refspec__parse(
+	struct git_refspec *refspec,
+	const char *str,
+	bool is_fetch);
+
+void git_refspec__free(git_refspec *refspec);
+
+int git_refspec__serialize(git_buf *out, const git_refspec *refspec);
+
+/**
+ * Determines if a refspec is a wildcard refspec.
+ *
+ * @param spec the refspec
+ * @return 1 if the refspec is a wildcard, 0 otherwise
+ */
+int git_refspec_is_wildcard(const git_refspec *spec);
+
+/**
+ * DWIM `spec` with `refs` existing on the remote, append the dwim'ed
+ * result in `out`.
+ */
+int git_refspec__dwim_one(git_vector *out, git_refspec *spec, git_vector *refs);
+
+#endif

vendor/libgit2-sys/libgit2/src/remote.c

diff --git a/vendor/libgit2-sys/libgit2/src/remote.c b/vendor/libgit2-sys/libgit2/src/remote.c
new file mode 100644
index 0000000..d8a6b99
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/remote.c
@@ -0,0 +1,2537 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "remote.h"
+
+#include "git2/config.h"
+#include "git2/types.h"
+#include "git2/oid.h"
+#include "git2/net.h"
+
+#include "config.h"
+#include "repository.h"
+#include "fetch.h"
+#include "refs.h"
+#include "refspec.h"
+#include "fetchhead.h"
+#include "push.h"
+
+#define CONFIG_URL_FMT "remote.%s.url"
+#define CONFIG_PUSHURL_FMT "remote.%s.pushurl"
+#define CONFIG_FETCH_FMT "remote.%s.fetch"
+#define CONFIG_PUSH_FMT "remote.%s.push"
+#define CONFIG_TAGOPT_FMT "remote.%s.tagopt"
+
+static int dwim_refspecs(git_vector *out, git_vector *refspecs, git_vector *refs);
+static int lookup_remote_prune_config(git_remote *remote, git_config *config, const char *name);
+char *apply_insteadof(git_config *config, const char *url, int direction);
+
+static int add_refspec_to(git_vector *vector, const char *string, bool is_fetch)
+{
+	git_refspec *spec;
+
+	spec = git__calloc(1, sizeof(git_refspec));
+	GITERR_CHECK_ALLOC(spec);
+
+	if (git_refspec__parse(spec, string, is_fetch) < 0) {
+		git__free(spec);
+		return -1;
+	}
+
+	spec->push = !is_fetch;
+	if (git_vector_insert(vector, spec) < 0) {
+		git_refspec__free(spec);
+		git__free(spec);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int add_refspec(git_remote *remote, const char *string, bool is_fetch)
+{
+	return add_refspec_to(&remote->refspecs, string, is_fetch);
+}
+
+static int download_tags_value(git_remote *remote, git_config *cfg)
+{
+	git_config_entry *ce;
+	git_buf buf = GIT_BUF_INIT;
+	int error;
+
+	if (git_buf_printf(&buf, "remote.%s.tagopt", remote->name) < 0)
+		return -1;
+
+	error = git_config__lookup_entry(&ce, cfg, git_buf_cstr(&buf), false);
+	git_buf_free(&buf);
+
+	if (!error && ce && ce->value) {
+		if (!strcmp(ce->value, "--no-tags"))
+			remote->download_tags = GIT_REMOTE_DOWNLOAD_TAGS_NONE;
+		else if (!strcmp(ce->value, "--tags"))
+			remote->download_tags = GIT_REMOTE_DOWNLOAD_TAGS_ALL;
+	}
+
+	git_config_entry_free(ce);
+	return error;
+}
+
+static int ensure_remote_name_is_valid(const char *name)
+{
+	int error = 0;
+
+	if (!git_remote_is_valid_name(name)) {
+		giterr_set(
+			GITERR_CONFIG,
+			"'%s' is not a valid remote name.", name ? name : "(null)");
+		error = GIT_EINVALIDSPEC;
+	}
+
+	return error;
+}
+
+static int write_add_refspec(git_repository *repo, const char *name, const char *refspec, bool fetch)
+{
+	git_config *cfg;
+	git_buf var = GIT_BUF_INIT;
+	git_refspec spec;
+	const char *fmt;
+	int error;
+
+	if ((error = git_repository_config__weakptr(&cfg, repo)) < 0)
+	    return error;
+
+	fmt = fetch ? CONFIG_FETCH_FMT : CONFIG_PUSH_FMT;
+
+	if ((error = ensure_remote_name_is_valid(name)) < 0)
+		return error;
+
+	if ((error = git_refspec__parse(&spec, refspec, fetch)) < 0) {
+		if (giterr_last()->klass != GITERR_NOMEMORY)
+			error = GIT_EINVALIDSPEC;
+
+		return error;
+	}
+
+	git_refspec__free(&spec);
+
+	if ((error = git_buf_printf(&var, fmt, name)) < 0)
+		return error;
+
+	/*
+	 * "$^" is a unmatcheable regexp: it will not match anything at all, so
+	 * all values will be considered new and we will not replace any
+	 * present value.
+	 */
+	if ((error = git_config_set_multivar(cfg, var.ptr, "$^", refspec)) < 0) {
+		goto cleanup;
+	}
+
+cleanup:
+	git_buf_free(&var);
+	return 0;
+}
+
+#if 0
+/* We could export this as a helper */
+static int get_check_cert(int *out, git_repository *repo)
+{
+	git_config *cfg;
+	const char *val;
+	int error = 0;
+
+	assert(out && repo);
+
+	/* By default, we *DO* want to verify the certificate. */
+	*out = 1;
+
+	/* Go through the possible sources for SSL verification settings, from
+	 * most specific to least specific. */
+
+	/* GIT_SSL_NO_VERIFY environment variable */
+	if ((val = p_getenv("GIT_SSL_NO_VERIFY")) != NULL)
+		return git_config_parse_bool(out, val);
+
+	/* http.sslVerify config setting */
+	if ((error = git_repository_config__weakptr(&cfg, repo)) < 0)
+		return error;
+
+	*out = git_config__get_bool_force(cfg, "http.sslverify", 1);
+	return 0;
+}
+#endif
+
+static int canonicalize_url(git_buf *out, const char *in)
+{
+	if (in == NULL || strlen(in) == 0) {
+		giterr_set(GITERR_INVALID, "cannot set empty URL");
+		return GIT_EINVALIDSPEC;
+	}
+
+#ifdef GIT_WIN32
+	/* Given a UNC path like \\server\path, we need to convert this
+	 * to //server/path for compatibility with core git.
+	 */
+	if (in[0] == '\\' && in[1] == '\\' &&
+		(git__isalpha(in[2]) || git__isdigit(in[2]))) {
+		const char *c;
+		for (c = in; *c; c++)
+			git_buf_putc(out, *c == '\\' ? '/' : *c);
+
+		return git_buf_oom(out) ? -1 : 0;
+	}
+#endif
+
+	return git_buf_puts(out, in);
+}
+
+static int create_internal(git_remote **out, git_repository *repo, const char *name, const char *url, const char *fetch)
+{
+	git_remote *remote;
+	git_config *config_ro = NULL, *config_rw;
+	git_buf canonical_url = GIT_BUF_INIT;
+	git_buf var = GIT_BUF_INIT;
+	int error = -1;
+
+	/* repo, name, and fetch are optional */
+	assert(out && url);
+
+	if (repo && (error = git_repository_config_snapshot(&config_ro, repo)) < 0)
+		return error;
+
+	remote = git__calloc(1, sizeof(git_remote));
+	GITERR_CHECK_ALLOC(remote);
+
+	remote->repo = repo;
+
+	if ((error = git_vector_init(&remote->refs, 32, NULL)) < 0 ||
+		(error = canonicalize_url(&canonical_url, url)) < 0)
+		goto on_error;
+
+	if (repo) {
+		remote->url = apply_insteadof(config_ro, canonical_url.ptr, GIT_DIRECTION_FETCH);
+	} else {
+		remote->url = git__strdup(canonical_url.ptr);
+	}
+	GITERR_CHECK_ALLOC(remote->url);
+
+	if (name != NULL) {
+		remote->name = git__strdup(name);
+		GITERR_CHECK_ALLOC(remote->name);
+
+		if ((error = git_buf_printf(&var, CONFIG_URL_FMT, name)) < 0)
+			goto on_error;
+
+		if (repo &&
+			((error = git_repository_config__weakptr(&config_rw, repo)) < 0 ||
+			(error = git_config_set_string(config_rw, var.ptr, canonical_url.ptr)) < 0))
+			goto on_error;
+	}
+
+	if (fetch != NULL) {
+		if ((error = add_refspec(remote, fetch, true)) < 0)
+			goto on_error;
+
+		/* only write for non-anonymous remotes */
+		if (repo && name && (error = write_add_refspec(repo, name, fetch, true)) < 0)
+			goto on_error;
+
+		if (repo && (error = lookup_remote_prune_config(remote, config_ro, name)) < 0)
+			goto on_error;
+
+		/* Move the data over to where the matching functions can find them */
+		if ((error = dwim_refspecs(&remote->active_refspecs, &remote->refspecs, &remote->refs)) < 0)
+			goto on_error;
+	}
+
+	/* A remote without a name doesn't download tags */
+	if (!name)
+		remote->download_tags = GIT_REMOTE_DOWNLOAD_TAGS_NONE;
+	else
+		remote->download_tags = GIT_REMOTE_DOWNLOAD_TAGS_AUTO;
+
+
+	git_buf_free(&var);
+
+	*out = remote;
+	error = 0;
+
+on_error:
+	if (error)
+		git_remote_free(remote);
+
+	git_config_free(config_ro);
+	git_buf_free(&canonical_url);
+	git_buf_free(&var);
+	return error;
+}
+
+static int ensure_remote_doesnot_exist(git_repository *repo, const char *name)
+{
+	int error;
+	git_remote *remote;
+
+	error = git_remote_lookup(&remote, repo, name);
+
+	if (error == GIT_ENOTFOUND)
+		return 0;
+
+	if (error < 0)
+		return error;
+
+	git_remote_free(remote);
+
+	giterr_set(
+		GITERR_CONFIG,
+		"remote '%s' already exists", name);
+
+	return GIT_EEXISTS;
+}
+
+
+int git_remote_create(git_remote **out, git_repository *repo, const char *name, const char *url)
+{
+	git_buf buf = GIT_BUF_INIT;
+	int error;
+
+	if (git_buf_printf(&buf, "+refs/heads/*:refs/remotes/%s/*", name) < 0)
+		return -1;
+
+	error = git_remote_create_with_fetchspec(out, repo, name, url, git_buf_cstr(&buf));
+	git_buf_free(&buf);
+
+	return error;
+}
+
+int git_remote_create_with_fetchspec(git_remote **out, git_repository *repo, const char *name, const char *url, const char *fetch)
+{
+	git_remote *remote = NULL;
+	int error;
+
+	if ((error = ensure_remote_name_is_valid(name)) < 0)
+		return error;
+
+	if ((error = ensure_remote_doesnot_exist(repo, name)) < 0)
+		return error;
+
+	if (create_internal(&remote, repo, name, url, fetch) < 0)
+		goto on_error;
+
+	*out = remote;
+
+	return 0;
+
+on_error:
+	git_remote_free(remote);
+	return -1;
+}
+
+int git_remote_create_anonymous(git_remote **out, git_repository *repo, const char *url)
+{
+	return create_internal(out, repo, NULL, url, NULL);
+}
+
+int git_remote_create_detached(git_remote **out, const char *url)
+{
+	return create_internal(out, NULL, NULL, url, NULL);
+}
+
+int git_remote_dup(git_remote **dest, git_remote *source)
+{
+	size_t i;
+	int error = 0;
+	git_refspec *spec;
+	git_remote *remote = git__calloc(1, sizeof(git_remote));
+	GITERR_CHECK_ALLOC(remote);
+
+	if (source->name != NULL) {
+		remote->name = git__strdup(source->name);
+		GITERR_CHECK_ALLOC(remote->name);
+	}
+
+	if (source->url != NULL) {
+		remote->url = git__strdup(source->url);
+		GITERR_CHECK_ALLOC(remote->url);
+	}
+
+	if (source->pushurl != NULL) {
+		remote->pushurl = git__strdup(source->pushurl);
+		GITERR_CHECK_ALLOC(remote->pushurl);
+	}
+
+	remote->repo = source->repo;
+	remote->download_tags = source->download_tags;
+	remote->prune_refs = source->prune_refs;
+
+	if (git_vector_init(&remote->refs, 32, NULL) < 0 ||
+	    git_vector_init(&remote->refspecs, 2, NULL) < 0 ||
+	    git_vector_init(&remote->active_refspecs, 2, NULL) < 0) {
+		error = -1;
+		goto cleanup;
+	}
+
+	git_vector_foreach(&source->refspecs, i, spec) {
+		if ((error = add_refspec(remote, spec->string, !spec->push)) < 0)
+			goto cleanup;
+	}
+
+	*dest = remote;
+
+cleanup:
+
+	if (error < 0)
+		git__free(remote);
+
+	return error;
+}
+
+struct refspec_cb_data {
+	git_remote *remote;
+	int fetch;
+};
+
+static int refspec_cb(const git_config_entry *entry, void *payload)
+{
+	struct refspec_cb_data *data = (struct refspec_cb_data *)payload;
+	return add_refspec(data->remote, entry->value, data->fetch);
+}
+
+static int get_optional_config(
+	bool *found, git_config *config, git_buf *buf,
+	git_config_foreach_cb cb, void *payload)
+{
+	int error = 0;
+	const char *key = git_buf_cstr(buf);
+
+	if (git_buf_oom(buf))
+		return -1;
+
+	if (cb != NULL)
+		error = git_config_get_multivar_foreach(config, key, NULL, cb, payload);
+	else
+		error = git_config_get_string(payload, config, key);
+
+	if (found)
+		*found = !error;
+
+	if (error == GIT_ENOTFOUND) {
+		giterr_clear();
+		error = 0;
+	}
+
+	return error;
+}
+
+int git_remote_lookup(git_remote **out, git_repository *repo, const char *name)
+{
+	git_remote *remote;
+	git_buf buf = GIT_BUF_INIT;
+	const char *val;
+	int error = 0;
+	git_config *config;
+	struct refspec_cb_data data = { NULL };
+	bool optional_setting_found = false, found;
+
+	assert(out && repo && name);
+
+	if ((error = ensure_remote_name_is_valid(name)) < 0)
+		return error;
+
+	if ((error = git_repository_config_snapshot(&config, repo)) < 0)
+		return error;
+
+	remote = git__calloc(1, sizeof(git_remote));
+	GITERR_CHECK_ALLOC(remote);
+
+	remote->name = git__strdup(name);
+	GITERR_CHECK_ALLOC(remote->name);
+
+	if (git_vector_init(&remote->refs, 32, NULL) < 0 ||
+	    git_vector_init(&remote->refspecs, 2, NULL) < 0 ||
+	    git_vector_init(&remote->passive_refspecs, 2, NULL) < 0 ||
+	    git_vector_init(&remote->active_refspecs, 2, NULL) < 0) {
+		error = -1;
+		goto cleanup;
+	}
+
+	if ((error = git_buf_printf(&buf, "remote.%s.url", name)) < 0)
+		goto cleanup;
+
+	if ((error = get_optional_config(&found, config, &buf, NULL, (void *)&val)) < 0)
+		goto cleanup;
+
+	optional_setting_found |= found;
+
+	remote->repo = repo;
+	remote->download_tags = GIT_REMOTE_DOWNLOAD_TAGS_AUTO;
+
+	if (found && strlen(val) > 0) {
+		remote->url = apply_insteadof(config, val, GIT_DIRECTION_FETCH);
+		GITERR_CHECK_ALLOC(remote->url);
+	}
+
+	val = NULL;
+	git_buf_clear(&buf);
+	git_buf_printf(&buf, "remote.%s.pushurl", name);
+
+	if ((error = get_optional_config(&found, config, &buf, NULL, (void *)&val)) < 0)
+		goto cleanup;
+
+	optional_setting_found |= found;
+
+	if (!optional_setting_found) {
+		error = GIT_ENOTFOUND;
+		giterr_set(GITERR_CONFIG, "remote '%s' does not exist", name);
+		goto cleanup;
+	}
+
+	if (found && strlen(val) > 0) {
+		remote->pushurl = apply_insteadof(config, val, GIT_DIRECTION_PUSH);
+		GITERR_CHECK_ALLOC(remote->pushurl);
+	}
+
+	data.remote = remote;
+	data.fetch = true;
+
+	git_buf_clear(&buf);
+	git_buf_printf(&buf, "remote.%s.fetch", name);
+
+	if ((error = get_optional_config(NULL, config, &buf, refspec_cb, &data)) < 0)
+		goto cleanup;
+
+	data.fetch = false;
+	git_buf_clear(&buf);
+	git_buf_printf(&buf, "remote.%s.push", name);
+
+	if ((error = get_optional_config(NULL, config, &buf, refspec_cb, &data)) < 0)
+		goto cleanup;
+
+	if (download_tags_value(remote, config) < 0)
+		goto cleanup;
+
+	if ((error = lookup_remote_prune_config(remote, config, name)) < 0)
+		goto cleanup;
+
+	/* Move the data over to where the matching functions can find them */
+	if ((error = dwim_refspecs(&remote->active_refspecs, &remote->refspecs, &remote->refs)) < 0)
+		goto cleanup;
+
+	*out = remote;
+
+cleanup:
+	git_config_free(config);
+	git_buf_free(&buf);
+
+	if (error < 0)
+		git_remote_free(remote);
+
+	return error;
+}
+
+static int lookup_remote_prune_config(git_remote *remote, git_config *config, const char *name)
+{
+	git_buf buf = GIT_BUF_INIT;
+	int error = 0;
+
+	git_buf_printf(&buf, "remote.%s.prune", name);
+
+	if ((error = git_config_get_bool(&remote->prune_refs, config, git_buf_cstr(&buf))) < 0) {
+		if (error == GIT_ENOTFOUND) {
+			giterr_clear();
+
+			if ((error = git_config_get_bool(&remote->prune_refs, config, "fetch.prune")) < 0) {
+				if (error == GIT_ENOTFOUND) {
+					giterr_clear();
+					error = 0;
+				}
+			}
+		}
+	}
+
+	git_buf_free(&buf);
+	return error;
+}
+
+const char *git_remote_name(const git_remote *remote)
+{
+	assert(remote);
+	return remote->name;
+}
+
+git_repository *git_remote_owner(const git_remote *remote)
+{
+	assert(remote);
+	return remote->repo;
+}
+
+const char *git_remote_url(const git_remote *remote)
+{
+	assert(remote);
+	return remote->url;
+}
+
+static int set_url(git_repository *repo, const char *remote, const char *pattern, const char *url)
+{
+	git_config *cfg;
+	git_buf buf = GIT_BUF_INIT, canonical_url = GIT_BUF_INIT;
+	int error;
+
+	assert(repo && remote);
+
+	if ((error = ensure_remote_name_is_valid(remote)) < 0)
+		return error;
+
+	if ((error = git_repository_config__weakptr(&cfg, repo)) < 0)
+		return error;
+
+	if ((error = git_buf_printf(&buf, pattern, remote)) < 0)
+		return error;
+
+	if (url) {
+		if ((error = canonicalize_url(&canonical_url, url)) < 0)
+			goto cleanup;
+
+		error = git_config_set_string(cfg, buf.ptr, url);
+	} else {
+		error = git_config_delete_entry(cfg, buf.ptr);
+	}
+
+cleanup:
+	git_buf_free(&canonical_url);
+	git_buf_free(&buf);
+
+	return error;
+}
+
+int git_remote_set_url(git_repository *repo, const char *remote, const char *url)
+{
+	return set_url(repo, remote, CONFIG_URL_FMT, url);
+}
+
+const char *git_remote_pushurl(const git_remote *remote)
+{
+	assert(remote);
+	return remote->pushurl;
+}
+
+int git_remote_set_pushurl(git_repository *repo, const char *remote, const char* url)
+{
+	return set_url(repo, remote, CONFIG_PUSHURL_FMT, url);
+}
+
+const char* git_remote__urlfordirection(git_remote *remote, int direction)
+{
+	assert(remote);
+
+	assert(direction == GIT_DIRECTION_FETCH || direction == GIT_DIRECTION_PUSH);
+
+	if (direction == GIT_DIRECTION_FETCH) {
+		return remote->url;
+	}
+
+	if (direction == GIT_DIRECTION_PUSH) {
+		return remote->pushurl ? remote->pushurl : remote->url;
+	}
+
+	return NULL;
+}
+
+int set_transport_callbacks(git_transport *t, const git_remote_callbacks *cbs)
+{
+	if (!t->set_callbacks || !cbs)
+		return 0;
+
+	return t->set_callbacks(t, cbs->sideband_progress, NULL,
+				cbs->certificate_check, cbs->payload);
+}
+
+static int set_transport_custom_headers(git_transport *t, const git_strarray *custom_headers)
+{
+	if (!t->set_custom_headers)
+		return 0;
+
+	return t->set_custom_headers(t, custom_headers);
+}
+
+int git_remote_connect(git_remote *remote, git_direction direction, const git_remote_callbacks *callbacks, const git_proxy_options *proxy, const git_strarray *custom_headers)
+{
+	git_transport *t;
+	const char *url;
+	int flags = GIT_TRANSPORTFLAGS_NONE;
+	int error;
+	void *payload = NULL;
+	git_cred_acquire_cb credentials = NULL;
+	git_transport_cb transport = NULL;
+
+	assert(remote);
+
+	if (callbacks) {
+		GITERR_CHECK_VERSION(callbacks, GIT_REMOTE_CALLBACKS_VERSION, "git_remote_callbacks");
+		credentials = callbacks->credentials;
+		transport   = callbacks->transport;
+		payload     = callbacks->payload;
+	}
+
+	if (proxy)
+		GITERR_CHECK_VERSION(proxy, GIT_PROXY_OPTIONS_VERSION, "git_proxy_options");
+
+	t = remote->transport;
+
+	url = git_remote__urlfordirection(remote, direction);
+	if (url == NULL) {
+		giterr_set(GITERR_INVALID,
+			"Malformed remote '%s' - missing %s URL",
+			remote->name ? remote->name : "(anonymous)",
+			direction == GIT_DIRECTION_FETCH ? "fetch" : "push");
+		return -1;
+	}
+
+	/* If we don't have a transport object yet, and the caller specified a
+	 * custom transport factory, use that */
+	if (!t && transport &&
+		(error = transport(&t, remote, payload)) < 0)
+		return error;
+
+	/* If we still don't have a transport, then use the global
+	 * transport registrations which map URI schemes to transport factories */
+	if (!t && (error = git_transport_new(&t, remote, url)) < 0)
+		return error;
+
+	if ((error = set_transport_custom_headers(t, custom_headers)) != 0)
+		goto on_error;
+
+	if ((error = set_transport_callbacks(t, callbacks)) < 0 ||
+	    (error = t->connect(t, url, credentials, payload, proxy, direction, flags)) != 0)
+		goto on_error;
+
+	remote->transport = t;
+
+	return 0;
+
+on_error:
+	t->free(t);
+
+	if (t == remote->transport)
+		remote->transport = NULL;
+
+	return error;
+}
+
+int git_remote_ls(const git_remote_head ***out, size_t *size, git_remote *remote)
+{
+	assert(remote);
+
+	if (!remote->transport) {
+		giterr_set(GITERR_NET, "this remote has never connected");
+		return -1;
+	}
+
+	return remote->transport->ls(out, size, remote->transport);
+}
+
+int git_remote__get_http_proxy(git_remote *remote, bool use_ssl, char **proxy_url)
+{
+	git_config *cfg;
+	git_config_entry *ce = NULL;
+	git_buf val = GIT_BUF_INIT;
+	int error;
+
+	assert(remote);
+
+	if (!proxy_url || !remote->repo)
+		return -1;
+
+	*proxy_url = NULL;
+
+	if ((error = git_repository_config__weakptr(&cfg, remote->repo)) < 0)
+		return error;
+
+	/* Go through the possible sources for proxy configuration, from most specific
+	 * to least specific. */
+
+	/* remote.<name>.proxy config setting */
+	if (remote->name && remote->name[0]) {
+		git_buf buf = GIT_BUF_INIT;
+
+		if ((error = git_buf_printf(&buf, "remote.%s.proxy", remote->name)) < 0)
+			return error;
+
+		error = git_config__lookup_entry(&ce, cfg, git_buf_cstr(&buf), false);
+		git_buf_free(&buf);
+
+		if (error < 0)
+			return error;
+
+		if (ce && ce->value) {
+			*proxy_url = git__strdup(ce->value);
+			goto found;
+		}
+	}
+
+	/* http.proxy config setting */
+	if ((error = git_config__lookup_entry(&ce, cfg, "http.proxy", false)) < 0)
+		return error;
+
+	if (ce && ce->value) {
+		*proxy_url = git__strdup(ce->value);
+		goto found;
+	}
+
+	/* http_proxy / https_proxy environment variables */
+	error = git__getenv(&val, use_ssl ? "https_proxy" : "http_proxy");
+
+	/* try uppercase environment variables */
+	if (error == GIT_ENOTFOUND)
+		error = git__getenv(&val, use_ssl ? "HTTPS_PROXY" : "HTTP_PROXY");
+
+	if (error < 0) {
+		if (error == GIT_ENOTFOUND) {
+			giterr_clear();
+			error = 0;
+		}
+
+		return error;
+	}
+
+	*proxy_url = git_buf_detach(&val);
+
+found:
+	GITERR_CHECK_ALLOC(*proxy_url);
+	git_config_entry_free(ce);
+
+	return 0;
+}
+
+/* DWIM `refspecs` based on `refs` and append the output to `out` */
+static int dwim_refspecs(git_vector *out, git_vector *refspecs, git_vector *refs)
+{
+	size_t i;
+	git_refspec *spec;
+
+	git_vector_foreach(refspecs, i, spec) {
+		if (git_refspec__dwim_one(out, spec, refs) < 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+static void free_refspecs(git_vector *vec)
+{
+	size_t i;
+	git_refspec *spec;
+
+	git_vector_foreach(vec, i, spec) {
+		git_refspec__free(spec);
+		git__free(spec);
+	}
+
+	git_vector_clear(vec);
+}
+
+static int remote_head_cmp(const void *_a, const void *_b)
+{
+	const git_remote_head *a = (git_remote_head *) _a;
+	const git_remote_head *b = (git_remote_head *) _b;
+
+	return git__strcmp_cb(a->name, b->name);
+}
+
+static int ls_to_vector(git_vector *out, git_remote *remote)
+{
+	git_remote_head **heads;
+	size_t heads_len, i;
+
+	if (git_remote_ls((const git_remote_head ***)&heads, &heads_len, remote) < 0)
+		return -1;
+
+	if (git_vector_init(out, heads_len, remote_head_cmp) < 0)
+		return -1;
+
+	for (i = 0; i < heads_len; i++) {
+		if (git_vector_insert(out, heads[i]) < 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+int git_remote_download(git_remote *remote, const git_strarray *refspecs, const git_fetch_options *opts)
+{
+	int error = -1;
+	size_t i;
+	git_vector *to_active, specs = GIT_VECTOR_INIT, refs = GIT_VECTOR_INIT;
+	const git_remote_callbacks *cbs = NULL;
+	const git_strarray *custom_headers = NULL;
+	const git_proxy_options *proxy = NULL;
+
+	assert(remote);
+
+	if (!remote->repo) {
+		giterr_set(GITERR_INVALID, "cannot download detached remote");
+		return -1;
+	}
+
+	if (opts) {
+		GITERR_CHECK_VERSION(&opts->callbacks, GIT_REMOTE_CALLBACKS_VERSION, "git_remote_callbacks");
+		cbs = &opts->callbacks;
+		custom_headers = &opts->custom_headers;
+		GITERR_CHECK_VERSION(&opts->proxy_opts, GIT_PROXY_OPTIONS_VERSION, "git_proxy_options");
+		proxy = &opts->proxy_opts;
+	}
+
+	if (!git_remote_connected(remote) &&
+	    (error = git_remote_connect(remote, GIT_DIRECTION_FETCH, cbs, proxy, custom_headers)) < 0)
+		goto on_error;
+
+	if (ls_to_vector(&refs, remote) < 0)
+		return -1;
+
+	if ((git_vector_init(&specs, 0, NULL)) < 0)
+		goto on_error;
+
+	remote->passed_refspecs = 0;
+	if (!refspecs || !refspecs->count) {
+		to_active = &remote->refspecs;
+	} else {
+		for (i = 0; i < refspecs->count; i++) {
+			if ((error = add_refspec_to(&specs, refspecs->strings[i], true)) < 0)
+				goto on_error;
+		}
+
+		to_active = &specs;
+		remote->passed_refspecs = 1;
+	}
+
+	free_refspecs(&remote->passive_refspecs);
+	if ((error = dwim_refspecs(&remote->passive_refspecs, &remote->refspecs, &refs)) < 0)
+		goto on_error;
+
+	free_refspecs(&remote->active_refspecs);
+	error = dwim_refspecs(&remote->active_refspecs, to_active, &refs);
+
+	git_vector_free(&refs);
+	free_refspecs(&specs);
+	git_vector_free(&specs);
+
+	if (error < 0)
+		return error;
+
+	if (remote->push) {
+		git_push_free(remote->push);
+		remote->push = NULL;
+	}
+
+	if ((error = git_fetch_negotiate(remote, opts)) < 0)
+		return error;
+
+	return git_fetch_download_pack(remote, cbs);
+
+on_error:
+	git_vector_free(&refs);
+	free_refspecs(&specs);
+	git_vector_free(&specs);
+	return error;
+}
+
+int git_remote_fetch(
+		git_remote *remote,
+		const git_strarray *refspecs,
+		const git_fetch_options *opts,
+		const char *reflog_message)
+{
+	int error, update_fetchhead = 1;
+	git_remote_autotag_option_t tagopt = remote->download_tags;
+	bool prune = false;
+	git_buf reflog_msg_buf = GIT_BUF_INIT;
+	const git_remote_callbacks *cbs = NULL;
+	const git_strarray *custom_headers = NULL;
+	const git_proxy_options *proxy = NULL;
+
+	if (opts) {
+		GITERR_CHECK_VERSION(&opts->callbacks, GIT_REMOTE_CALLBACKS_VERSION, "git_remote_callbacks");
+		cbs = &opts->callbacks;
+		custom_headers = &opts->custom_headers;
+		update_fetchhead = opts->update_fetchhead;
+		tagopt = opts->download_tags;
+		GITERR_CHECK_VERSION(&opts->proxy_opts, GIT_PROXY_OPTIONS_VERSION, "git_proxy_options");
+		proxy = &opts->proxy_opts;
+	}
+
+	/* Connect and download everything */
+	if ((error = git_remote_connect(remote, GIT_DIRECTION_FETCH, cbs, proxy, custom_headers)) != 0)
+		return error;
+
+	error = git_remote_download(remote, refspecs, opts);
+
+	/* We don't need to be connected anymore */
+	git_remote_disconnect(remote);
+
+	/* If the download failed, return the error */
+	if (error != 0)
+		return error;
+
+	/* Default reflog message */
+	if (reflog_message)
+		git_buf_sets(&reflog_msg_buf, reflog_message);
+	else {
+		git_buf_printf(&reflog_msg_buf, "fetch %s",
+				remote->name ? remote->name : remote->url);
+	}
+
+	/* Create "remote/foo" branches for all remote branches */
+	error = git_remote_update_tips(remote, cbs, update_fetchhead, tagopt, git_buf_cstr(&reflog_msg_buf));
+	git_buf_free(&reflog_msg_buf);
+	if (error < 0)
+		return error;
+
+	if (opts && opts->prune == GIT_FETCH_PRUNE)
+		prune = true;
+	else if (opts && opts->prune == GIT_FETCH_PRUNE_UNSPECIFIED && remote->prune_refs)
+		prune = true;
+	else if (opts && opts->prune == GIT_FETCH_NO_PRUNE)
+		prune = false;
+	else
+		prune = remote->prune_refs;
+
+	if (prune)
+		error = git_remote_prune(remote, cbs);
+
+	return error;
+}
+
+static int remote_head_for_fetchspec_src(git_remote_head **out, git_vector *update_heads, const char *fetchspec_src)
+{
+	unsigned int i;
+	git_remote_head *remote_ref;
+
+	assert(update_heads && fetchspec_src);
+
+	*out = NULL;
+
+	git_vector_foreach(update_heads, i, remote_ref) {
+		if (strcmp(remote_ref->name, fetchspec_src) == 0) {
+			*out = remote_ref;
+			break;
+		}
+	}
+
+	return 0;
+}
+
+static int ref_to_update(int *update, git_buf *remote_name, git_remote *remote, git_refspec *spec, const char *ref_name)
+{
+	int error = 0;
+	git_repository *repo;
+	git_buf upstream_remote = GIT_BUF_INIT;
+	git_buf upstream_name = GIT_BUF_INIT;
+
+	repo = git_remote_owner(remote);
+
+	if ((!git_reference__is_branch(ref_name)) ||
+	    !git_remote_name(remote) ||
+	    (error = git_branch_upstream_remote(&upstream_remote, repo, ref_name) < 0) ||
+	    git__strcmp(git_remote_name(remote), git_buf_cstr(&upstream_remote)) ||
+	    (error = git_branch_upstream_name(&upstream_name, repo, ref_name)) < 0 ||
+	    !git_refspec_dst_matches(spec, git_buf_cstr(&upstream_name)) ||
+	    (error = git_refspec_rtransform(remote_name, spec, upstream_name.ptr)) < 0) {
+		/* Not an error if there is no upstream */
+		if (error == GIT_ENOTFOUND) {
+			giterr_clear();
+			error = 0;
+		}
+
+		*update = 0;
+	} else {
+		*update = 1;
+	}
+
+	git_buf_free(&upstream_remote);
+	git_buf_free(&upstream_name);
+	return error;
+}
+
+static int remote_head_for_ref(git_remote_head **out, git_remote *remote, git_refspec *spec, git_vector *update_heads, git_reference *ref)
+{
+	git_reference *resolved_ref = NULL;
+	git_buf remote_name = GIT_BUF_INIT;
+	git_config *config = NULL;
+	const char *ref_name;
+	int error = 0, update;
+
+	assert(out && spec && ref);
+
+	*out = NULL;
+
+	error = git_reference_resolve(&resolved_ref, ref);
+
+	/* If we're in an unborn branch, let's pretend nothing happened */
+	if (error == GIT_ENOTFOUND && git_reference_type(ref) == GIT_REF_SYMBOLIC) {
+		ref_name = git_reference_symbolic_target(ref);
+		error = 0;
+	} else {
+		ref_name = git_reference_name(resolved_ref);
+	}
+
+	if ((error = ref_to_update(&update, &remote_name, remote, spec, ref_name)) < 0)
+		goto cleanup;
+
+	if (update)
+		error = remote_head_for_fetchspec_src(out, update_heads, git_buf_cstr(&remote_name));
+
+cleanup:
+	git_buf_free(&remote_name);
+	git_reference_free(resolved_ref);
+	git_config_free(config);
+	return error;
+}
+
+static int git_remote_write_fetchhead(git_remote *remote, git_refspec *spec, git_vector *update_heads)
+{
+	git_reference *head_ref = NULL;
+	git_fetchhead_ref *fetchhead_ref;
+	git_remote_head *remote_ref, *merge_remote_ref;
+	git_vector fetchhead_refs;
+	bool include_all_fetchheads;
+	unsigned int i = 0;
+	int error = 0;
+
+	assert(remote);
+
+	/* no heads, nothing to do */
+	if (update_heads->length == 0)
+		return 0;
+
+	if (git_vector_init(&fetchhead_refs, update_heads->length, git_fetchhead_ref_cmp) < 0)
+		return -1;
+
+	/* Iff refspec is * (but not subdir slash star), include tags */
+	include_all_fetchheads = (strcmp(GIT_REFS_HEADS_DIR "*", git_refspec_src(spec)) == 0);
+
+	/* Determine what to merge: if refspec was a wildcard, just use HEAD */
+	if (git_refspec_is_wildcard(spec)) {
+		if ((error = git_reference_lookup(&head_ref, remote->repo, GIT_HEAD_FILE)) < 0 ||
+			(error = remote_head_for_ref(&merge_remote_ref, remote, spec, update_heads, head_ref)) < 0)
+				goto cleanup;
+	} else {
+		/* If we're fetching a single refspec, that's the only thing that should be in FETCH_HEAD. */
+		if ((error = remote_head_for_fetchspec_src(&merge_remote_ref, update_heads, git_refspec_src(spec))) < 0)
+			goto cleanup;
+	}
+
+	/* Create the FETCH_HEAD file */
+	git_vector_foreach(update_heads, i, remote_ref) {
+		int merge_this_fetchhead = (merge_remote_ref == remote_ref);
+
+		if (!include_all_fetchheads &&
+			!git_refspec_src_matches(spec, remote_ref->name) &&
+			!merge_this_fetchhead)
+			continue;
+
+		if (git_fetchhead_ref_create(&fetchhead_ref,
+			&remote_ref->oid,
+			merge_this_fetchhead,
+			remote_ref->name,
+			git_remote_url(remote)) < 0)
+			goto cleanup;
+
+		if (git_vector_insert(&fetchhead_refs, fetchhead_ref) < 0)
+			goto cleanup;
+	}
+
+	git_fetchhead_write(remote->repo, &fetchhead_refs);
+
+cleanup:
+	for (i = 0; i < fetchhead_refs.length; ++i)
+		git_fetchhead_ref_free(fetchhead_refs.contents[i]);
+
+	git_vector_free(&fetchhead_refs);
+	git_reference_free(head_ref);
+
+	return error;
+}
+
+/**
+ * Generate a list of candidates for pruning by getting a list of
+ * references which match the rhs of an active refspec.
+ */
+static int prune_candidates(git_vector *candidates, git_remote *remote)
+{
+	git_strarray arr = { 0 };
+	size_t i;
+	int error;
+
+	if ((error = git_reference_list(&arr, remote->repo)) < 0)
+		return error;
+
+	for (i = 0; i < arr.count; i++) {
+		const char *refname = arr.strings[i];
+		char *refname_dup;
+
+		if (!git_remote__matching_dst_refspec(remote, refname))
+			continue;
+
+		refname_dup = git__strdup(refname);
+		GITERR_CHECK_ALLOC(refname_dup);
+
+		if ((error = git_vector_insert(candidates, refname_dup)) < 0)
+			goto out;
+	}
+
+out:
+	git_strarray_free(&arr);
+	return error;
+}
+
+static int find_head(const void *_a, const void *_b)
+{
+	git_remote_head *a = (git_remote_head *) _a;
+	git_remote_head *b = (git_remote_head *) _b;
+
+	return strcmp(a->name, b->name);
+}
+
+int git_remote_prune(git_remote *remote, const git_remote_callbacks *callbacks)
+{
+	size_t i, j;
+	git_vector remote_refs = GIT_VECTOR_INIT;
+	git_vector candidates = GIT_VECTOR_INIT;
+	const git_refspec *spec;
+	const char *refname;
+	int error;
+	git_oid zero_id = {{ 0 }};
+
+	if (callbacks)
+		GITERR_CHECK_VERSION(callbacks, GIT_REMOTE_CALLBACKS_VERSION, "git_remote_callbacks");
+
+	if ((error = ls_to_vector(&remote_refs, remote)) < 0)
+		goto cleanup;
+
+	git_vector_set_cmp(&remote_refs, find_head);
+
+	if ((error = prune_candidates(&candidates, remote)) < 0)
+		goto cleanup;
+
+	/*
+	 * Remove those entries from the candidate list for which we
+	 * can find a remote reference in at least one refspec.
+	 */
+	git_vector_foreach(&candidates, i, refname) {
+		git_vector_foreach(&remote->active_refspecs, j, spec) {
+			git_buf buf = GIT_BUF_INIT;
+			size_t pos;
+			char *src_name;
+			git_remote_head key = {0};
+
+			if (!git_refspec_dst_matches(spec, refname))
+				continue;
+
+			if ((error = git_refspec_rtransform(&buf, spec, refname)) < 0)
+				goto cleanup;
+
+			key.name = (char *) git_buf_cstr(&buf);
+			error = git_vector_search(&pos, &remote_refs, &key);
+			git_buf_free(&buf);
+
+			if (error < 0 && error != GIT_ENOTFOUND)
+				goto cleanup;
+
+			if (error == GIT_ENOTFOUND)
+				continue;
+
+			/* if we did find a source, remove it from the candiates */
+			if ((error = git_vector_set((void **) &src_name, &candidates, i, NULL)) < 0)
+				goto cleanup;
+
+			git__free(src_name);
+			break;
+		}
+	}
+
+	/*
+	 * For those candidates still left in the list, we need to
+	 * remove them. We do not remove symrefs, as those are for
+	 * stuff like origin/HEAD which will never match, but we do
+	 * not want to remove them.
+	 */
+	git_vector_foreach(&candidates, i, refname) {
+		git_reference *ref;
+		git_oid id;
+
+		if (refname == NULL)
+			continue;
+
+		error = git_reference_lookup(&ref, remote->repo, refname);
+		/* as we want it gone, let's not consider this an error */
+		if (error == GIT_ENOTFOUND)
+			continue;
+
+		if (error < 0)
+			goto cleanup;
+
+		if (git_reference_type(ref) == GIT_REF_SYMBOLIC) {
+			git_reference_free(ref);
+			continue;
+		}
+
+		git_oid_cpy(&id, git_reference_target(ref));
+		error = git_reference_delete(ref);
+		git_reference_free(ref);
+		if (error < 0)
+			goto cleanup;
+
+		if (callbacks && callbacks->update_tips)
+			error = callbacks->update_tips(refname, &id, &zero_id, callbacks->payload);
+
+		if (error < 0)
+			goto cleanup;
+	}
+
+cleanup:
+	git_vector_free(&remote_refs);
+	git_vector_free_deep(&candidates);
+	return error;
+}
+
+static int update_tips_for_spec(
+		git_remote *remote,
+		const git_remote_callbacks *callbacks,
+		int update_fetchhead,
+		git_remote_autotag_option_t tagopt,
+		git_refspec *spec,
+		git_vector *refs,
+		const char *log_message)
+{
+	int error = 0, autotag;
+	unsigned int i = 0;
+	git_buf refname = GIT_BUF_INIT;
+	git_oid old;
+	git_odb *odb;
+	git_remote_head *head;
+	git_reference *ref;
+	git_refspec tagspec;
+	git_vector update_heads;
+
+	assert(remote);
+
+	if (git_repository_odb__weakptr(&odb, remote->repo) < 0)
+		return -1;
+
+	if (git_refspec__parse(&tagspec, GIT_REFSPEC_TAGS, true) < 0)
+		return -1;
+
+	/* Make a copy of the transport's refs */
+	if (git_vector_init(&update_heads, 16, NULL) < 0)
+		return -1;
+
+	for (; i < refs->length; ++i) {
+		head = git_vector_get(refs, i);
+		autotag = 0;
+		git_buf_clear(&refname);
+
+		/* Ignore malformed ref names (which also saves us from tag^{} */
+		if (!git_reference_is_valid_name(head->name))
+			continue;
+
+		/* If we have a tag, see if the auto-follow rules say to update it */
+		if (git_refspec_src_matches(&tagspec, head->name)) {
+			if (tagopt != GIT_REMOTE_DOWNLOAD_TAGS_NONE) {
+
+				if (tagopt == GIT_REMOTE_DOWNLOAD_TAGS_AUTO)
+					autotag = 1;
+
+				git_buf_clear(&refname);
+				if (git_buf_puts(&refname, head->name) < 0)
+					goto on_error;
+			}
+		}
+
+		/* If we didn't want to auto-follow the tag, check if the refspec matches */
+		if (!autotag && git_refspec_src_matches(spec, head->name)) {
+			if (spec->dst) {
+				if (git_refspec_transform(&refname, spec, head->name) < 0)
+					goto on_error;
+			} else {
+				/*
+				 * no rhs mans store it in FETCH_HEAD, even if we don't
+				 update anything else.
+				 */
+				if ((error = git_vector_insert(&update_heads, head)) < 0)
+					goto on_error;
+
+				continue;
+			}
+		}
+
+		/* If we still don't have a refname, we don't want it */
+		if (git_buf_len(&refname) == 0) {
+			continue;
+		}
+
+		/* In autotag mode, only create tags for objects already in db */
+		if (autotag && !git_odb_exists(odb, &head->oid))
+			continue;
+
+		if (!autotag && git_vector_insert(&update_heads, head) < 0)
+			goto on_error;
+
+		error = git_reference_name_to_id(&old, remote->repo, refname.ptr);
+		if (error < 0 && error != GIT_ENOTFOUND)
+			goto on_error;
+
+		if (error == GIT_ENOTFOUND) {
+			memset(&old, 0, GIT_OID_RAWSZ);
+
+			if (autotag && git_vector_insert(&update_heads, head) < 0)
+				goto on_error;
+		}
+
+		if (!git_oid__cmp(&old, &head->oid))
+			continue;
+
+		/* In autotag mode, don't overwrite any locally-existing tags */
+		error = git_reference_create(&ref, remote->repo, refname.ptr, &head->oid, !autotag, 
+				log_message);
+
+		if (error == GIT_EEXISTS)
+			continue;
+
+		if (error < 0)
+			goto on_error;
+
+		git_reference_free(ref);
+
+		if (callbacks && callbacks->update_tips != NULL) {
+			if (callbacks->update_tips(refname.ptr, &old, &head->oid, callbacks->payload) < 0)
+				goto on_error;
+		}
+	}
+
+	if (update_fetchhead &&
+	    (error = git_remote_write_fetchhead(remote, spec, &update_heads)) < 0)
+		goto on_error;
+
+	git_vector_free(&update_heads);
+	git_refspec__free(&tagspec);
+	git_buf_free(&refname);
+	return 0;
+
+on_error:
+	git_vector_free(&update_heads);
+	git_refspec__free(&tagspec);
+	git_buf_free(&refname);
+	return -1;
+
+}
+
+/**
+ * Iteration over the three vectors, with a pause whenever we find a match
+ *
+ * On each stop, we store the iteration stat in the inout i,j,k
+ * parameters, and return the currently matching passive refspec as
+ * well as the head which we matched.
+ */
+static int next_head(const git_remote *remote, git_vector *refs,
+		     git_refspec **out_spec, git_remote_head **out_head,
+		     size_t *out_i, size_t *out_j, size_t *out_k)
+{
+	const git_vector *active, *passive;
+	git_remote_head *head;
+	git_refspec *spec, *passive_spec;
+	size_t i, j, k;
+
+	active = &remote->active_refspecs;
+	passive = &remote->passive_refspecs;
+
+	i = *out_i;
+	j = *out_j;
+	k = *out_k;
+
+	for (; i < refs->length; i++) {
+		head = git_vector_get(refs, i);
+
+		if (!git_reference_is_valid_name(head->name))
+			continue;
+
+		for (; j < active->length; j++) {
+			spec = git_vector_get(active, j);
+
+			if (!git_refspec_src_matches(spec, head->name))
+				continue;
+
+			for (; k < passive->length; k++) {
+				passive_spec = git_vector_get(passive, k);
+
+				if (!git_refspec_src_matches(passive_spec, head->name))
+				    continue;
+
+				*out_spec = passive_spec;
+				*out_head = head;
+				*out_i = i;
+				*out_j = j;
+				*out_k = k + 1;
+				return 0;
+
+			}
+			k = 0;
+		}
+		j = 0;
+	}
+
+	return GIT_ITEROVER;
+}
+
+static int opportunistic_updates(const git_remote *remote, const git_remote_callbacks *callbacks,
+				 git_vector *refs, const char *msg)
+{
+	size_t i, j, k;
+	git_refspec *spec;
+	git_remote_head *head;
+	git_reference *ref;
+	git_buf refname = GIT_BUF_INIT;
+	int error = 0;
+
+	i = j = k = 0;
+
+	while ((error = next_head(remote, refs, &spec, &head, &i, &j, &k)) == 0) {
+		git_oid old = {{ 0 }};
+		/*
+		 * If we got here, there is a refspec which was used
+		 * for fetching which matches the source of one of the
+		 * passive refspecs, so we should update that
+		 * remote-tracking branch, but not add it to
+		 * FETCH_HEAD
+		 */
+
+		git_buf_clear(&refname);
+		if ((error = git_refspec_transform(&refname, spec, head->name)) < 0)
+			goto cleanup;
+
+		error = git_reference_name_to_id(&old, remote->repo, refname.ptr);
+		if (error < 0 && error != GIT_ENOTFOUND)
+			goto cleanup;
+
+		if (!git_oid_cmp(&old, &head->oid))
+			continue;
+
+		/* If we did find a current reference, make sure we haven't lost a race */
+		if (error)
+			error = git_reference_create(&ref, remote->repo, refname.ptr, &head->oid, true, msg);
+		else
+			error = git_reference_create_matching(&ref, remote->repo, refname.ptr, &head->oid, true, &old, msg);
+		git_reference_free(ref);
+		if (error < 0)
+			goto cleanup;
+
+		if (callbacks && callbacks->update_tips != NULL) {
+			if (callbacks->update_tips(refname.ptr, &old, &head->oid, callbacks->payload) < 0)
+				goto cleanup;
+		}
+	}
+
+	if (error == GIT_ITEROVER)
+		error = 0;
+
+cleanup:
+	git_buf_free(&refname);
+	return error;
+}
+
+static int truncate_fetch_head(const char *gitdir)
+{
+	git_buf path = GIT_BUF_INIT;
+	int error;
+
+	if ((error = git_buf_joinpath(&path, gitdir, GIT_FETCH_HEAD_FILE)) < 0)
+		return error;
+
+	error = git_futils_truncate(path.ptr, GIT_REFS_FILE_MODE);
+	git_buf_free(&path);
+
+	return error;
+}
+
+int git_remote_update_tips(
+		git_remote *remote,
+		const git_remote_callbacks *callbacks,
+		int update_fetchhead,
+		git_remote_autotag_option_t download_tags,
+		const char *reflog_message)
+{
+	git_refspec *spec, tagspec;
+	git_vector refs = GIT_VECTOR_INIT;
+	git_remote_autotag_option_t tagopt;
+	int error;
+	size_t i;
+
+	/* push has its own logic hidden away in the push object */
+	if (remote->push) {
+		return git_push_update_tips(remote->push, callbacks);
+	}
+
+	if (git_refspec__parse(&tagspec, GIT_REFSPEC_TAGS, true) < 0)
+		return -1;
+
+
+	if ((error = ls_to_vector(&refs, remote)) < 0)
+		goto out;
+
+	if (download_tags == GIT_REMOTE_DOWNLOAD_TAGS_UNSPECIFIED)
+		tagopt = remote->download_tags;
+	else
+		tagopt = download_tags;
+
+	if ((error = truncate_fetch_head(git_repository_path(remote->repo))) < 0)
+		goto out;
+
+	if (tagopt == GIT_REMOTE_DOWNLOAD_TAGS_ALL) {
+		if ((error = update_tips_for_spec(remote, callbacks, update_fetchhead, tagopt, &tagspec, &refs, reflog_message)) < 0)
+			goto out;
+	}
+
+	git_vector_foreach(&remote->active_refspecs, i, spec) {
+		if (spec->push)
+			continue;
+
+		if ((error = update_tips_for_spec(remote, callbacks, update_fetchhead, tagopt, spec, &refs, reflog_message)) < 0)
+			goto out;
+	}
+
+	/* only try to do opportunisitic updates if the refpec lists differ */
+	if (remote->passed_refspecs)
+		error = opportunistic_updates(remote, callbacks, &refs, reflog_message);
+
+out:
+	git_vector_free(&refs);
+	git_refspec__free(&tagspec);
+	return error;
+}
+
+int git_remote_connected(const git_remote *remote)
+{
+	assert(remote);
+
+	if (!remote->transport || !remote->transport->is_connected)
+		return 0;
+
+	/* Ask the transport if it's connected. */
+	return remote->transport->is_connected(remote->transport);
+}
+
+void git_remote_stop(git_remote *remote)
+{
+	assert(remote);
+
+	if (remote->transport && remote->transport->cancel)
+		remote->transport->cancel(remote->transport);
+}
+
+void git_remote_disconnect(git_remote *remote)
+{
+	assert(remote);
+
+	if (git_remote_connected(remote))
+		remote->transport->close(remote->transport);
+}
+
+void git_remote_free(git_remote *remote)
+{
+	if (remote == NULL)
+		return;
+
+	if (remote->transport != NULL) {
+		git_remote_disconnect(remote);
+
+		remote->transport->free(remote->transport);
+		remote->transport = NULL;
+	}
+
+	git_vector_free(&remote->refs);
+
+	free_refspecs(&remote->refspecs);
+	git_vector_free(&remote->refspecs);
+
+	free_refspecs(&remote->active_refspecs);
+	git_vector_free(&remote->active_refspecs);
+
+	free_refspecs(&remote->passive_refspecs);
+	git_vector_free(&remote->passive_refspecs);
+
+	git_push_free(remote->push);
+	git__free(remote->url);
+	git__free(remote->pushurl);
+	git__free(remote->name);
+	git__free(remote);
+}
+
+static int remote_list_cb(const git_config_entry *entry, void *payload)
+{
+	git_vector *list = payload;
+	const char *name = entry->name + strlen("remote.");
+	size_t namelen = strlen(name);
+	char *remote_name;
+
+	/* we know name matches "remote.<stuff>.(push)?url" */
+
+	if (!strcmp(&name[namelen - 4], ".url"))
+		remote_name = git__strndup(name, namelen - 4); /* strip ".url" */
+	else
+		remote_name = git__strndup(name, namelen - 8); /* strip ".pushurl" */
+	GITERR_CHECK_ALLOC(remote_name);
+
+	return git_vector_insert(list, remote_name);
+}
+
+int git_remote_list(git_strarray *remotes_list, git_repository *repo)
+{
+	int error;
+	git_config *cfg;
+	git_vector list = GIT_VECTOR_INIT;
+
+	if ((error = git_repository_config__weakptr(&cfg, repo)) < 0)
+		return error;
+
+	if ((error = git_vector_init(&list, 4, git__strcmp_cb)) < 0)
+		return error;
+
+	error = git_config_foreach_match(
+		cfg, "^remote\\..*\\.(push)?url$", remote_list_cb, &list);
+
+	if (error < 0) {
+		git_vector_free_deep(&list);
+		return error;
+	}
+
+	git_vector_uniq(&list, git__free);
+
+	remotes_list->strings =
+		(char **)git_vector_detach(&remotes_list->count, NULL, &list);
+
+	return 0;
+}
+
+const git_transfer_progress* git_remote_stats(git_remote *remote)
+{
+	assert(remote);
+	return &remote->stats;
+}
+
+git_remote_autotag_option_t git_remote_autotag(const git_remote *remote)
+{
+	return remote->download_tags;
+}
+
+int git_remote_set_autotag(git_repository *repo, const char *remote, git_remote_autotag_option_t value)
+{
+	git_buf var = GIT_BUF_INIT;
+	git_config *config;
+	int error;
+
+	assert(repo && remote);
+
+	if ((error = ensure_remote_name_is_valid(remote)) < 0)
+		return error;
+
+	if ((error = git_repository_config__weakptr(&config, repo)) < 0)
+		return error;
+
+	if ((error = git_buf_printf(&var, CONFIG_TAGOPT_FMT, remote)))
+		return error;
+
+	switch (value) {
+	case GIT_REMOTE_DOWNLOAD_TAGS_NONE:
+		error = git_config_set_string(config, var.ptr, "--no-tags");
+		break;
+	case GIT_REMOTE_DOWNLOAD_TAGS_ALL:
+		error = git_config_set_string(config, var.ptr, "--tags");
+		break;
+	case GIT_REMOTE_DOWNLOAD_TAGS_AUTO:
+		error = git_config_delete_entry(config, var.ptr);
+		if (error == GIT_ENOTFOUND)
+			error = 0;
+		break;
+	default:
+		giterr_set(GITERR_INVALID, "invalid value for the tagopt setting");
+		error = -1;
+	}
+
+	git_buf_free(&var);
+	return error;
+}
+
+int git_remote_prune_refs(const git_remote *remote)
+{
+	return remote->prune_refs;
+}
+
+static int rename_remote_config_section(
+	git_repository *repo,
+	const char *old_name,
+	const char *new_name)
+{
+	git_buf old_section_name = GIT_BUF_INIT,
+		new_section_name = GIT_BUF_INIT;
+	int error = -1;
+
+	if (git_buf_printf(&old_section_name, "remote.%s", old_name) < 0)
+		goto cleanup;
+
+	if (new_name &&
+		(git_buf_printf(&new_section_name, "remote.%s", new_name) < 0))
+			goto cleanup;
+
+	error = git_config_rename_section(
+		repo,
+		git_buf_cstr(&old_section_name),
+		new_name ? git_buf_cstr(&new_section_name) : NULL);
+
+cleanup:
+	git_buf_free(&old_section_name);
+	git_buf_free(&new_section_name);
+
+	return error;
+}
+
+struct update_data {
+	git_config *config;
+	const char *old_remote_name;
+	const char *new_remote_name;
+};
+
+static int update_config_entries_cb(
+	const git_config_entry *entry,
+	void *payload)
+{
+	struct update_data *data = (struct update_data *)payload;
+
+	if (strcmp(entry->value, data->old_remote_name))
+		return 0;
+
+	return git_config_set_string(
+		data->config, entry->name, data->new_remote_name);
+}
+
+static int update_branch_remote_config_entry(
+	git_repository *repo,
+	const char *old_name,
+	const char *new_name)
+{
+	int error;
+	struct update_data data = { NULL };
+
+	if ((error = git_repository_config__weakptr(&data.config, repo)) < 0)
+		return error;
+
+	data.old_remote_name = old_name;
+	data.new_remote_name = new_name;
+
+	return git_config_foreach_match(
+		data.config, "branch\\..+\\.remote", update_config_entries_cb, &data);
+}
+
+static int rename_one_remote_reference(
+	git_reference *reference_in,
+	const char *old_remote_name,
+	const char *new_remote_name)
+{
+	int error;
+	git_reference *ref = NULL, *dummy = NULL;
+	git_buf namespace = GIT_BUF_INIT, old_namespace = GIT_BUF_INIT;
+	git_buf new_name = GIT_BUF_INIT;
+	git_buf log_message = GIT_BUF_INIT;
+	size_t pfx_len;
+	const char *target;
+
+	if ((error = git_buf_printf(&namespace, GIT_REFS_REMOTES_DIR "%s/", new_remote_name)) < 0)
+		return error;
+
+	pfx_len = strlen(GIT_REFS_REMOTES_DIR) + strlen(old_remote_name) + 1;
+	git_buf_puts(&new_name, namespace.ptr);
+	if ((error = git_buf_puts(&new_name, git_reference_name(reference_in) + pfx_len)) < 0)
+		goto cleanup;
+
+	if ((error = git_buf_printf(&log_message,
+					"renamed remote %s to %s",
+					old_remote_name, new_remote_name)) < 0)
+		goto cleanup;
+
+	if ((error = git_reference_rename(&ref, reference_in, git_buf_cstr(&new_name), 1,
+					  git_buf_cstr(&log_message))) < 0)
+		goto cleanup;
+
+	if (git_reference_type(ref) != GIT_REF_SYMBOLIC)
+		goto cleanup;
+
+	/* Handle refs like origin/HEAD -> origin/master */
+	target = git_reference_symbolic_target(ref);
+	if ((error = git_buf_printf(&old_namespace, GIT_REFS_REMOTES_DIR "%s/", old_remote_name)) < 0)
+		goto cleanup;
+
+	if (git__prefixcmp(target, old_namespace.ptr))
+		goto cleanup;
+
+	git_buf_clear(&new_name);
+	git_buf_puts(&new_name, namespace.ptr);
+	if ((error = git_buf_puts(&new_name, target + pfx_len)) < 0)
+		goto cleanup;
+
+	error = git_reference_symbolic_set_target(&dummy, ref, git_buf_cstr(&new_name),
+						  git_buf_cstr(&log_message));
+
+	git_reference_free(dummy);
+
+cleanup:
+	git_reference_free(reference_in);
+	git_reference_free(ref);
+	git_buf_free(&namespace);
+	git_buf_free(&old_namespace);
+	git_buf_free(&new_name);
+	git_buf_free(&log_message);
+	return error;
+}
+
+static int rename_remote_references(
+	git_repository *repo,
+	const char *old_name,
+	const char *new_name)
+{
+	int error;
+	git_buf buf = GIT_BUF_INIT;
+	git_reference *ref;
+	git_reference_iterator *iter;
+
+	if ((error = git_buf_printf(&buf, GIT_REFS_REMOTES_DIR "%s/*", old_name)) < 0)
+		return error;
+
+	error = git_reference_iterator_glob_new(&iter, repo, git_buf_cstr(&buf));
+	git_buf_free(&buf);
+
+	if (error < 0)
+		return error;
+
+	while ((error = git_reference_next(&ref, iter)) == 0) {
+		if ((error = rename_one_remote_reference(ref, old_name, new_name)) < 0)
+			break;
+	}
+
+	git_reference_iterator_free(iter);
+
+	return (error == GIT_ITEROVER) ? 0 : error;
+}
+
+static int rename_fetch_refspecs(git_vector *problems, git_remote *remote, const char *new_name)
+{
+	git_config *config;
+	git_buf base = GIT_BUF_INIT, var = GIT_BUF_INIT, val = GIT_BUF_INIT;
+	const git_refspec *spec;
+	size_t i;
+	int error = 0;
+
+	if ((error = git_repository_config__weakptr(&config, remote->repo)) < 0)
+		return error;
+
+	if ((error = git_vector_init(problems, 1, NULL)) < 0)
+		return error;
+
+	if ((error = git_buf_printf(
+			&base, "+refs/heads/*:refs/remotes/%s/*", remote->name)) < 0)
+		return error;
+
+	git_vector_foreach(&remote->refspecs, i, spec) {
+		if (spec->push)
+			continue;
+
+		/* Does the dst part of the refspec follow the expected format? */
+		if (strcmp(git_buf_cstr(&base), spec->string)) {
+			char *dup;
+
+			dup = git__strdup(spec->string);
+			GITERR_CHECK_ALLOC(dup);
+
+			if ((error = git_vector_insert(problems, dup)) < 0)
+				break;
+
+			continue;
+		}
+
+		/* If we do want to move it to the new section */
+
+		git_buf_clear(&val);
+		git_buf_clear(&var);
+
+		if (git_buf_printf(
+				&val, "+refs/heads/*:refs/remotes/%s/*", new_name) < 0 ||
+			git_buf_printf(&var, "remote.%s.fetch", new_name) < 0)
+		{
+			error = -1;
+			break;
+		}
+
+		if ((error = git_config_set_string(
+				config, git_buf_cstr(&var), git_buf_cstr(&val))) < 0)
+			break;
+	}
+
+	git_buf_free(&base);
+	git_buf_free(&var);
+	git_buf_free(&val);
+
+	if (error < 0) {
+		char *str;
+		git_vector_foreach(problems, i, str)
+			git__free(str);
+
+		git_vector_free(problems);
+	}
+
+	return error;
+}
+
+int git_remote_rename(git_strarray *out, git_repository *repo, const char *name, const char *new_name)
+{
+	int error;
+	git_vector problem_refspecs = GIT_VECTOR_INIT;
+	git_remote *remote = NULL;
+
+	assert(out && repo && name && new_name);
+
+	if ((error = git_remote_lookup(&remote, repo, name)) < 0)
+		return error;
+
+	if ((error = ensure_remote_name_is_valid(new_name)) < 0)
+		goto cleanup;
+
+	if ((error = ensure_remote_doesnot_exist(repo, new_name)) < 0)
+		goto cleanup;
+
+	if ((error = rename_remote_config_section(repo, name, new_name)) < 0)
+		goto cleanup;
+
+	if ((error = update_branch_remote_config_entry(repo, name, new_name)) < 0)
+		goto cleanup;
+
+	if ((error = rename_remote_references(repo, name, new_name)) < 0)
+		goto cleanup;
+
+	if ((error = rename_fetch_refspecs(&problem_refspecs, remote, new_name)) < 0)
+		goto cleanup;
+
+	out->count = problem_refspecs.length;
+	out->strings = (char **) problem_refspecs.contents;
+
+cleanup:
+	if (error < 0)
+		git_vector_free(&problem_refspecs);
+
+	git_remote_free(remote);
+	return error;
+}
+
+int git_remote_is_valid_name(
+	const char *remote_name)
+{
+	git_buf buf = GIT_BUF_INIT;
+	git_refspec refspec;
+	int error = -1;
+
+	if (!remote_name || *remote_name == '\0')
+		return 0;
+
+	git_buf_printf(&buf, "refs/heads/test:refs/remotes/%s/test", remote_name);
+	error = git_refspec__parse(&refspec, git_buf_cstr(&buf), true);
+
+	git_buf_free(&buf);
+	git_refspec__free(&refspec);
+
+	giterr_clear();
+	return error == 0;
+}
+
+git_refspec *git_remote__matching_refspec(git_remote *remote, const char *refname)
+{
+	git_refspec *spec;
+	size_t i;
+
+	git_vector_foreach(&remote->active_refspecs, i, spec) {
+		if (spec->push)
+			continue;
+
+		if (git_refspec_src_matches(spec, refname))
+			return spec;
+	}
+
+	return NULL;
+}
+
+git_refspec *git_remote__matching_dst_refspec(git_remote *remote, const char *refname)
+{
+	git_refspec *spec;
+	size_t i;
+
+	git_vector_foreach(&remote->active_refspecs, i, spec) {
+		if (spec->push)
+			continue;
+
+		if (git_refspec_dst_matches(spec, refname))
+			return spec;
+	}
+
+	return NULL;
+}
+
+int git_remote_add_fetch(git_repository *repo, const char *remote, const char *refspec)
+{
+	return write_add_refspec(repo, remote, refspec, true);
+}
+
+int git_remote_add_push(git_repository *repo, const char *remote, const char *refspec)
+{
+	return write_add_refspec(repo, remote, refspec, false);
+}
+
+static int copy_refspecs(git_strarray *array, const git_remote *remote, unsigned int push)
+{
+	size_t i;
+	git_vector refspecs;
+	git_refspec *spec;
+	char *dup;
+
+	if (git_vector_init(&refspecs, remote->refspecs.length, NULL) < 0)
+		return -1;
+
+	git_vector_foreach(&remote->refspecs, i, spec) {
+		if (spec->push != push)
+			continue;
+
+		if ((dup = git__strdup(spec->string)) == NULL)
+			goto on_error;
+
+		if (git_vector_insert(&refspecs, dup) < 0) {
+			git__free(dup);
+			goto on_error;
+		}
+	}
+
+	array->strings = (char **)refspecs.contents;
+	array->count = refspecs.length;
+
+	return 0;
+
+on_error:
+	git_vector_free_deep(&refspecs);
+
+	return -1;
+}
+
+int git_remote_get_fetch_refspecs(git_strarray *array, const git_remote *remote)
+{
+	return copy_refspecs(array, remote, false);
+}
+
+int git_remote_get_push_refspecs(git_strarray *array, const git_remote *remote)
+{
+	return copy_refspecs(array, remote, true);
+}
+
+size_t git_remote_refspec_count(const git_remote *remote)
+{
+	return remote->refspecs.length;
+}
+
+const git_refspec *git_remote_get_refspec(const git_remote *remote, size_t n)
+{
+	return git_vector_get(&remote->refspecs, n);
+}
+
+int git_remote_init_callbacks(git_remote_callbacks *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_remote_callbacks, GIT_REMOTE_CALLBACKS_INIT);
+	return 0;
+}
+
+/* asserts a branch.<foo>.remote format */
+static const char *name_offset(size_t *len_out, const char *name)
+{
+	size_t prefix_len;
+	const char *dot;
+
+	prefix_len = strlen("remote.");
+	dot = strchr(name + prefix_len, '.');
+
+	assert(dot);
+
+	*len_out = dot - name - prefix_len;
+	return name + prefix_len;
+}
+
+static int remove_branch_config_related_entries(
+	git_repository *repo,
+	const char *remote_name)
+{
+	int error;
+	git_config *config;
+	git_config_entry *entry;
+	git_config_iterator *iter;
+	git_buf buf = GIT_BUF_INIT;
+
+	if ((error = git_repository_config__weakptr(&config, repo)) < 0)
+		return error;
+
+	if ((error = git_config_iterator_glob_new(&iter, config, "branch\\..+\\.remote")) < 0)
+		return error;
+
+	/* find any branches with us as upstream and remove that config */
+	while ((error = git_config_next(&entry, iter)) == 0) {
+		const char *branch;
+		size_t branch_len;
+
+		if (strcmp(remote_name, entry->value))
+			continue;
+
+		branch = name_offset(&branch_len, entry->name);
+
+		git_buf_clear(&buf);
+		if (git_buf_printf(&buf, "branch.%.*s.merge", (int)branch_len, branch) < 0)
+			break;
+
+		if ((error = git_config_delete_entry(config, git_buf_cstr(&buf))) < 0) {
+			if (error != GIT_ENOTFOUND)
+				break;
+			giterr_clear();
+		}
+
+		git_buf_clear(&buf);
+		if (git_buf_printf(&buf, "branch.%.*s.remote", (int)branch_len, branch) < 0)
+			break;
+
+		if ((error = git_config_delete_entry(config, git_buf_cstr(&buf))) < 0) {
+			if (error != GIT_ENOTFOUND)
+				break;
+			giterr_clear();
+		}
+	}
+
+	if (error == GIT_ITEROVER)
+		error = 0;
+
+	git_buf_free(&buf);
+	git_config_iterator_free(iter);
+	return error;
+}
+
+static int remove_refs(git_repository *repo, const git_refspec *spec)
+{
+	git_reference_iterator *iter = NULL;
+	git_vector refs;
+	const char *name;
+	char *dup;
+	int error;
+	size_t i;
+
+	if ((error = git_vector_init(&refs, 8, NULL)) < 0)
+		return error;
+
+	if ((error = git_reference_iterator_new(&iter, repo)) < 0)
+		goto cleanup;
+
+	while ((error = git_reference_next_name(&name, iter)) == 0) {
+		if (!git_refspec_dst_matches(spec, name))
+			continue;
+
+		dup = git__strdup(name);
+		if (!dup) {
+			error = -1;
+			goto cleanup;
+		}
+
+		if ((error = git_vector_insert(&refs, dup)) < 0)
+			goto cleanup;
+	}
+	if (error == GIT_ITEROVER)
+		error = 0;
+	if (error < 0)
+		goto cleanup;
+
+	git_vector_foreach(&refs, i, name) {
+		if ((error = git_reference_remove(repo, name)) < 0)
+			break;
+	}
+
+cleanup:
+	git_reference_iterator_free(iter);
+	git_vector_foreach(&refs, i, dup) {
+		git__free(dup);
+	}
+	git_vector_free(&refs);
+	return error;
+}
+
+static int remove_remote_tracking(git_repository *repo, const char *remote_name)
+{
+	git_remote *remote;
+	int error;
+	size_t i, count;
+
+	/* we want to use what's on the config, regardless of changes to the instance in memory */
+	if ((error = git_remote_lookup(&remote, repo, remote_name)) < 0)
+		return error;
+
+	count = git_remote_refspec_count(remote);
+	for (i = 0; i < count; i++) {
+		const git_refspec *refspec = git_remote_get_refspec(remote, i);
+
+		/* shouldn't ever actually happen */
+		if (refspec == NULL)
+			continue;
+
+		if ((error = remove_refs(repo, refspec)) < 0)
+			break;
+	}
+
+	git_remote_free(remote);
+	return error;
+}
+
+int git_remote_delete(git_repository *repo, const char *name)
+{
+	int error;
+
+	assert(repo && name);
+
+	if ((error = remove_branch_config_related_entries(repo, name)) < 0 ||
+	    (error = remove_remote_tracking(repo, name)) < 0 ||
+	    (error = rename_remote_config_section(repo, name, NULL)) < 0)
+		return error;
+
+	return 0;
+}
+
+int git_remote_default_branch(git_buf *out, git_remote *remote)
+{
+	const git_remote_head **heads;
+	const git_remote_head *guess = NULL;
+	const git_oid *head_id;
+	size_t heads_len, i;
+	int error;
+
+	assert(out);
+
+	if ((error = git_remote_ls(&heads, &heads_len, remote)) < 0)
+		return error;
+
+	if (heads_len == 0)
+		return GIT_ENOTFOUND;
+
+	if (strcmp(heads[0]->name, GIT_HEAD_FILE))
+		return GIT_ENOTFOUND;
+
+	git_buf_sanitize(out);
+	/* the first one must be HEAD so if that has the symref info, we're done */
+	if (heads[0]->symref_target)
+		return git_buf_puts(out, heads[0]->symref_target);
+
+	/*
+	 * If there's no symref information, we have to look over them
+	 * and guess. We return the first match unless the master
+	 * branch is a candidate. Then we return the master branch.
+	 */
+	head_id = &heads[0]->oid;
+
+	for (i = 1; i < heads_len; i++) {
+		if (git_oid_cmp(head_id, &heads[i]->oid))
+			continue;
+
+		if (git__prefixcmp(heads[i]->name, GIT_REFS_HEADS_DIR))
+			continue;
+
+		if (!guess) {
+			guess = heads[i];
+			continue;
+		}
+
+		if (!git__strcmp(GIT_REFS_HEADS_MASTER_FILE, heads[i]->name)) {
+			guess = heads[i];
+			break;
+		}
+	}
+
+	if (!guess)
+		return GIT_ENOTFOUND;
+
+	return git_buf_puts(out, guess->name);
+}
+
+int git_remote_upload(git_remote *remote, const git_strarray *refspecs, const git_push_options *opts)
+{
+	size_t i;
+	int error;
+	git_push *push;
+	git_refspec *spec;
+	const git_remote_callbacks *cbs = NULL;
+	const git_strarray *custom_headers = NULL;
+	const git_proxy_options *proxy = NULL;
+
+	assert(remote);
+
+	if (!remote->repo) {
+		giterr_set(GITERR_INVALID, "cannot download detached remote");
+		return -1;
+	}
+
+	if (opts) {
+		cbs = &opts->callbacks;
+		custom_headers = &opts->custom_headers;
+		proxy = &opts->proxy_opts;
+	}
+
+	if (!git_remote_connected(remote) &&
+	    (error = git_remote_connect(remote, GIT_DIRECTION_PUSH, cbs, proxy, custom_headers)) < 0)
+		goto cleanup;
+
+	free_refspecs(&remote->active_refspecs);
+	if ((error = dwim_refspecs(&remote->active_refspecs, &remote->refspecs, &remote->refs)) < 0)
+		goto cleanup;
+
+	if (remote->push) {
+		git_push_free(remote->push);
+		remote->push = NULL;
+	}
+
+	if ((error = git_push_new(&remote->push, remote)) < 0)
+		return error;
+
+	push = remote->push;
+
+	if (opts && (error = git_push_set_options(push, opts)) < 0)
+		goto cleanup;
+
+	if (refspecs && refspecs->count > 0) {
+		for (i = 0; i < refspecs->count; i++) {
+			if ((error = git_push_add_refspec(push, refspecs->strings[i])) < 0)
+				goto cleanup;
+		}
+	} else {
+		git_vector_foreach(&remote->refspecs, i, spec) {
+			if (!spec->push)
+				continue;
+			if ((error = git_push_add_refspec(push, spec->string)) < 0)
+				goto cleanup;
+		}
+	}
+
+	if ((error = git_push_finish(push, cbs)) < 0)
+		goto cleanup;
+
+	if (cbs && cbs->push_update_reference &&
+	    (error = git_push_status_foreach(push, cbs->push_update_reference, cbs->payload)) < 0)
+		goto cleanup;
+
+cleanup:
+	return error;
+}
+
+int git_remote_push(git_remote *remote, const git_strarray *refspecs, const git_push_options *opts)
+{
+	int error;
+	const git_remote_callbacks *cbs = NULL;
+	const git_strarray *custom_headers = NULL;
+	const git_proxy_options *proxy = NULL;
+
+	assert(remote);
+
+	if (!remote->repo) {
+		giterr_set(GITERR_INVALID, "cannot download detached remote");
+		return -1;
+	}
+
+	if (opts) {
+		GITERR_CHECK_VERSION(&opts->callbacks, GIT_REMOTE_CALLBACKS_VERSION, "git_remote_callbacks");
+		cbs = &opts->callbacks;
+		custom_headers = &opts->custom_headers;
+		GITERR_CHECK_VERSION(&opts->proxy_opts, GIT_PROXY_OPTIONS_VERSION, "git_proxy_options");
+		proxy = &opts->proxy_opts;
+	}
+
+	assert(remote);
+
+	if ((error = git_remote_connect(remote, GIT_DIRECTION_PUSH, cbs, proxy, custom_headers)) < 0)
+		return error;
+
+	if ((error = git_remote_upload(remote, refspecs, opts)) < 0)
+		return error;
+
+	error = git_remote_update_tips(remote, cbs, 0, 0, NULL);
+
+	git_remote_disconnect(remote);
+	return error;
+}
+
+#define PREFIX "url"
+#define SUFFIX_FETCH "insteadof"
+#define SUFFIX_PUSH "pushinsteadof"
+
+char *apply_insteadof(git_config *config, const char *url, int direction)
+{
+	size_t match_length, prefix_length, suffix_length;
+	char *replacement = NULL;
+	const char *regexp;
+
+	git_buf result = GIT_BUF_INIT;
+	git_config_entry *entry;
+	git_config_iterator *iter;
+
+	assert(config);
+	assert(url);
+	assert(direction == GIT_DIRECTION_FETCH || direction == GIT_DIRECTION_PUSH);
+
+	/* Add 1 to prefix/suffix length due to the additional escaped dot */
+	prefix_length = strlen(PREFIX) + 1;
+	if (direction == GIT_DIRECTION_FETCH) {
+		regexp = PREFIX "\\..*\\." SUFFIX_FETCH;
+		suffix_length = strlen(SUFFIX_FETCH) + 1;
+	} else {
+		regexp = PREFIX "\\..*\\." SUFFIX_PUSH;
+		suffix_length = strlen(SUFFIX_PUSH) + 1;
+	}
+
+	if (git_config_iterator_glob_new(&iter, config, regexp) < 0)
+		return NULL;
+
+	match_length = 0;
+	while (git_config_next(&entry, iter) == 0) {
+		size_t n, replacement_length;
+
+		/* Check if entry value is a prefix of URL */
+		if (git__prefixcmp(url, entry->value))
+			continue;
+		/* Check if entry value is longer than previous
+		 * prefixes */
+		if ((n = strlen(entry->value)) <= match_length)
+			continue;
+
+		git__free(replacement);
+		match_length = n;
+
+		/* Cut off prefix and suffix of the value */
+		replacement_length =
+		    strlen(entry->name) - (prefix_length + suffix_length);
+		replacement = git__strndup(entry->name + prefix_length,
+				replacement_length);
+	}
+
+	git_config_iterator_free(iter);
+
+	if (match_length == 0)
+		return git__strdup(url);
+
+	git_buf_printf(&result, "%s%s", replacement, url + match_length);
+
+	git__free(replacement);
+
+	return result.ptr;
+}

vendor/libgit2-sys/libgit2/src/remote.h

diff --git a/vendor/libgit2-sys/libgit2/src/remote.h b/vendor/libgit2-sys/libgit2/src/remote.h
new file mode 100644
index 0000000..a94481f
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/remote.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_remote_h__
+#define INCLUDE_remote_h__
+
+#include "common.h"
+
+#include "git2/remote.h"
+#include "git2/transport.h"
+#include "git2/sys/transport.h"
+
+#include "refspec.h"
+#include "vector.h"
+
+#define GIT_REMOTE_ORIGIN "origin"
+
+struct git_remote {
+	char *name;
+	char *url;
+	char *pushurl;
+	git_vector refs;
+	git_vector refspecs;
+	git_vector active_refspecs;
+	git_vector passive_refspecs;
+	git_transport *transport;
+	git_repository *repo;
+	git_push *push;
+	git_transfer_progress stats;
+	unsigned int need_pack;
+	git_remote_autotag_option_t download_tags;
+	int prune_refs;
+	int passed_refspecs;
+};
+
+const char* git_remote__urlfordirection(struct git_remote *remote, int direction);
+int git_remote__get_http_proxy(git_remote *remote, bool use_ssl, char **proxy_url);
+
+git_refspec *git_remote__matching_refspec(git_remote *remote, const char *refname);
+git_refspec *git_remote__matching_dst_refspec(git_remote *remote, const char *refname);
+
+#endif

vendor/libgit2-sys/libgit2/src/repo_template.h

diff --git a/vendor/libgit2-sys/libgit2/src/repo_template.h b/vendor/libgit2-sys/libgit2/src/repo_template.h
new file mode 100644
index 0000000..099279a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/repo_template.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_repo_template_h__
+#define INCLUDE_repo_template_h__
+
+#define GIT_OBJECTS_INFO_DIR GIT_OBJECTS_DIR "info/"
+#define GIT_OBJECTS_PACK_DIR GIT_OBJECTS_DIR "pack/"
+
+#define GIT_HOOKS_DIR "hooks/"
+#define GIT_HOOKS_DIR_MODE 0777
+
+#define GIT_HOOKS_README_FILE GIT_HOOKS_DIR "README.sample"
+#define GIT_HOOKS_README_MODE 0777
+#define GIT_HOOKS_README_CONTENT \
+"#!/bin/sh\n"\
+"#\n"\
+"# Place appropriately named executable hook scripts into this directory\n"\
+"# to intercept various actions that git takes.  See `git help hooks` for\n"\
+"# more information.\n"
+
+#define GIT_INFO_DIR "info/"
+#define GIT_INFO_DIR_MODE 0777
+
+#define GIT_INFO_EXCLUDE_FILE GIT_INFO_DIR "exclude"
+#define GIT_INFO_EXCLUDE_MODE 0666
+#define GIT_INFO_EXCLUDE_CONTENT \
+"# File patterns to ignore; see `git help ignore` for more information.\n"\
+"# Lines that start with '#' are comments.\n"
+
+#define GIT_DESC_FILE "description"
+#define GIT_DESC_MODE 0666
+#define GIT_DESC_CONTENT \
+"Unnamed repository; edit this file 'description' to name the repository.\n"
+
+typedef struct {
+	const char *path;
+	mode_t mode;
+	const char *content;
+} repo_template_item;
+
+static repo_template_item repo_template[] = {
+	{ GIT_OBJECTS_INFO_DIR, GIT_OBJECT_DIR_MODE, NULL }, /* '/objects/info/' */
+	{ GIT_OBJECTS_PACK_DIR, GIT_OBJECT_DIR_MODE, NULL }, /* '/objects/pack/' */
+	{ GIT_REFS_HEADS_DIR, GIT_REFS_DIR_MODE, NULL },     /* '/refs/heads/' */
+	{ GIT_REFS_TAGS_DIR, GIT_REFS_DIR_MODE, NULL },      /* '/refs/tags/' */
+	{ GIT_HOOKS_DIR, GIT_HOOKS_DIR_MODE, NULL },         /* '/hooks/' */
+	{ GIT_INFO_DIR, GIT_INFO_DIR_MODE, NULL },           /* '/info/' */
+	{ GIT_DESC_FILE, GIT_DESC_MODE, GIT_DESC_CONTENT },
+	{ GIT_HOOKS_README_FILE, GIT_HOOKS_README_MODE, GIT_HOOKS_README_CONTENT },
+	{ GIT_INFO_EXCLUDE_FILE, GIT_INFO_EXCLUDE_MODE, GIT_INFO_EXCLUDE_CONTENT },
+	{ NULL, 0, NULL }
+};
+
+#endif

vendor/libgit2-sys/libgit2/src/repository.c

diff --git a/vendor/libgit2-sys/libgit2/src/repository.c b/vendor/libgit2-sys/libgit2/src/repository.c
new file mode 100644
index 0000000..3c89879
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/repository.c
@@ -0,0 +1,2892 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "repository.h"
+
+#include <ctype.h>
+
+#include "git2/object.h"
+#include "git2/sys/repository.h"
+
+#include "common.h"
+#include "commit.h"
+#include "tag.h"
+#include "blob.h"
+#include "fileops.h"
+#include "sysdir.h"
+#include "filebuf.h"
+#include "index.h"
+#include "config.h"
+#include "refs.h"
+#include "filter.h"
+#include "odb.h"
+#include "refdb.h"
+#include "remote.h"
+#include "merge.h"
+#include "diff_driver.h"
+#include "annotated_commit.h"
+#include "submodule.h"
+#include "worktree.h"
+
+#include "strmap.h"
+
+#ifdef GIT_WIN32
+# include "win32/w32_util.h"
+#endif
+
+bool git_repository__fsync_gitdir = false;
+
+static const struct {
+    git_repository_item_t parent;
+    const char *name;
+    bool directory;
+} items[] = {
+	{ GIT_REPOSITORY_ITEM_GITDIR, NULL, true },
+	{ GIT_REPOSITORY_ITEM_WORKDIR, NULL, true },
+	{ GIT_REPOSITORY_ITEM_COMMONDIR, NULL, true },
+	{ GIT_REPOSITORY_ITEM_GITDIR, "index", false },
+	{ GIT_REPOSITORY_ITEM_COMMONDIR, "objects", true },
+	{ GIT_REPOSITORY_ITEM_COMMONDIR, "refs", true },
+	{ GIT_REPOSITORY_ITEM_COMMONDIR, "packed-refs", false },
+	{ GIT_REPOSITORY_ITEM_COMMONDIR, "remotes", true },
+	{ GIT_REPOSITORY_ITEM_COMMONDIR, "config", false },
+	{ GIT_REPOSITORY_ITEM_COMMONDIR, "info", true },
+	{ GIT_REPOSITORY_ITEM_COMMONDIR, "hooks", true },
+	{ GIT_REPOSITORY_ITEM_COMMONDIR, "logs", true },
+	{ GIT_REPOSITORY_ITEM_GITDIR, "modules", true },
+	{ GIT_REPOSITORY_ITEM_COMMONDIR, "worktrees", true }
+};
+
+static int check_repositoryformatversion(git_config *config);
+
+#define GIT_COMMONDIR_FILE "commondir"
+#define GIT_GITDIR_FILE "gitdir"
+
+#define GIT_FILE_CONTENT_PREFIX "gitdir:"
+
+#define GIT_BRANCH_MASTER "master"
+
+#define GIT_REPO_VERSION 0
+
+git_buf git_repository__reserved_names_win32[] = {
+	{ DOT_GIT, 0, CONST_STRLEN(DOT_GIT) },
+	{ GIT_DIR_SHORTNAME, 0, CONST_STRLEN(GIT_DIR_SHORTNAME) }
+};
+size_t git_repository__reserved_names_win32_len = 2;
+
+git_buf git_repository__reserved_names_posix[] = {
+	{ DOT_GIT, 0, CONST_STRLEN(DOT_GIT) },
+};
+size_t git_repository__reserved_names_posix_len = 1;
+
+static void set_odb(git_repository *repo, git_odb *odb)
+{
+	if (odb) {
+		GIT_REFCOUNT_OWN(odb, repo);
+		GIT_REFCOUNT_INC(odb);
+	}
+
+	if ((odb = git__swap(repo->_odb, odb)) != NULL) {
+		GIT_REFCOUNT_OWN(odb, NULL);
+		git_odb_free(odb);
+	}
+}
+
+static void set_refdb(git_repository *repo, git_refdb *refdb)
+{
+	if (refdb) {
+		GIT_REFCOUNT_OWN(refdb, repo);
+		GIT_REFCOUNT_INC(refdb);
+	}
+
+	if ((refdb = git__swap(repo->_refdb, refdb)) != NULL) {
+		GIT_REFCOUNT_OWN(refdb, NULL);
+		git_refdb_free(refdb);
+	}
+}
+
+static void set_config(git_repository *repo, git_config *config)
+{
+	if (config) {
+		GIT_REFCOUNT_OWN(config, repo);
+		GIT_REFCOUNT_INC(config);
+	}
+
+	if ((config = git__swap(repo->_config, config)) != NULL) {
+		GIT_REFCOUNT_OWN(config, NULL);
+		git_config_free(config);
+	}
+
+	git_repository__cvar_cache_clear(repo);
+}
+
+static void set_index(git_repository *repo, git_index *index)
+{
+	if (index) {
+		GIT_REFCOUNT_OWN(index, repo);
+		GIT_REFCOUNT_INC(index);
+	}
+
+	if ((index = git__swap(repo->_index, index)) != NULL) {
+		GIT_REFCOUNT_OWN(index, NULL);
+		git_index_free(index);
+	}
+}
+
+void git_repository__cleanup(git_repository *repo)
+{
+	assert(repo);
+
+	git_repository_submodule_cache_clear(repo);
+	git_cache_clear(&repo->objects);
+	git_attr_cache_flush(repo);
+
+	set_config(repo, NULL);
+	set_index(repo, NULL);
+	set_odb(repo, NULL);
+	set_refdb(repo, NULL);
+}
+
+void git_repository_free(git_repository *repo)
+{
+	size_t i;
+
+	if (repo == NULL)
+		return;
+
+	git_repository__cleanup(repo);
+
+	git_cache_free(&repo->objects);
+
+	git_diff_driver_registry_free(repo->diff_drivers);
+	repo->diff_drivers = NULL;
+
+	for (i = 0; i < repo->reserved_names.size; i++)
+		git_buf_free(git_array_get(repo->reserved_names, i));
+	git_array_clear(repo->reserved_names);
+
+	git__free(repo->gitlink);
+	git__free(repo->gitdir);
+	git__free(repo->commondir);
+	git__free(repo->workdir);
+	git__free(repo->namespace);
+	git__free(repo->ident_name);
+	git__free(repo->ident_email);
+
+	git__memzero(repo, sizeof(*repo));
+	git__free(repo);
+}
+
+/*
+ * Git repository open methods
+ *
+ * Open a repository object from its path
+ */
+static bool valid_repository_path(git_buf *repository_path, git_buf *common_path)
+{
+	/* Check if we have a separate commondir (e.g. we have a
+	 * worktree) */
+	if (git_path_contains_file(repository_path, GIT_COMMONDIR_FILE)) {
+		git_buf common_link  = GIT_BUF_INIT;
+		git_buf_joinpath(&common_link, repository_path->ptr, GIT_COMMONDIR_FILE);
+
+		git_futils_readbuffer(&common_link, common_link.ptr);
+		git_buf_rtrim(&common_link);
+
+		if (git_path_is_relative(common_link.ptr)) {
+			git_buf_joinpath(common_path, repository_path->ptr, common_link.ptr);
+		} else {
+			git_buf_swap(common_path, &common_link);
+		}
+
+		git_buf_free(&common_link);
+	}
+	else {
+		git_buf_set(common_path, repository_path->ptr, repository_path->size);
+	}
+
+	/* Make sure the commondir path always has a trailing * slash */
+	if (git_buf_rfind(common_path, '/') != (ssize_t)common_path->size - 1)
+		git_buf_putc(common_path, '/');
+
+	/* Ensure HEAD file exists */
+	if (git_path_contains_file(repository_path, GIT_HEAD_FILE) == false)
+		return false;
+
+	/* Check files in common dir */
+	if (git_path_contains_dir(common_path, GIT_OBJECTS_DIR) == false)
+		return false;
+	if (git_path_contains_dir(common_path, GIT_REFS_DIR) == false)
+		return false;
+
+	return true;
+}
+
+static git_repository *repository_alloc(void)
+{
+	git_repository *repo = git__calloc(1, sizeof(git_repository));
+
+	if (repo == NULL ||
+		git_cache_init(&repo->objects) < 0)
+		goto on_error;
+
+	git_array_init_to_size(repo->reserved_names, 4);
+	if (!repo->reserved_names.ptr)
+		goto on_error;
+
+	/* set all the entries in the cvar cache to `unset` */
+	git_repository__cvar_cache_clear(repo);
+
+	return repo;
+
+on_error:
+	if (repo)
+		git_cache_free(&repo->objects);
+
+	git__free(repo);
+	return NULL;
+}
+
+int git_repository_new(git_repository **out)
+{
+	git_repository *repo;
+
+	*out = repo = repository_alloc();
+	GITERR_CHECK_ALLOC(repo);
+
+	repo->is_bare = 1;
+	repo->is_worktree = 0;
+
+	return 0;
+}
+
+static int load_config_data(git_repository *repo, const git_config *config)
+{
+	int is_bare;
+
+	int err = git_config_get_bool(&is_bare, config, "core.bare");
+	if (err < 0 && err != GIT_ENOTFOUND)
+		return err;
+
+	/* Try to figure out if it's bare, default to non-bare if it's not set */
+	if (err != GIT_ENOTFOUND)
+		repo->is_bare = is_bare && !repo->is_worktree;
+	else
+		repo->is_bare = 0;
+
+	return 0;
+}
+
+static int load_workdir(git_repository *repo, git_config *config, git_buf *parent_path)
+{
+	int error;
+	git_config_entry *ce;
+	git_buf worktree = GIT_BUF_INIT;
+	git_buf path = GIT_BUF_INIT;
+
+	if (repo->is_bare)
+		return 0;
+
+	if ((error = git_config__lookup_entry(
+			&ce, config, "core.worktree", false)) < 0)
+		return error;
+
+	if (repo->is_worktree) {
+		char *gitlink = git_worktree__read_link(repo->gitdir, GIT_GITDIR_FILE);
+		if (!gitlink) {
+			error = -1;
+			goto cleanup;
+		}
+
+		git_buf_attach(&worktree, gitlink, 0);
+
+		if ((git_path_dirname_r(&worktree, worktree.ptr)) < 0 ||
+		    git_path_to_dir(&worktree) < 0) {
+			error = -1;
+			goto cleanup;
+		}
+
+		repo->workdir = git_buf_detach(&worktree);
+	}
+	else if (ce && ce->value) {
+		if ((error = git_path_prettify_dir(
+				&worktree, ce->value, repo->gitdir)) < 0)
+			goto cleanup;
+
+		repo->workdir = git_buf_detach(&worktree);
+	}
+	else if (parent_path && git_path_isdir(parent_path->ptr))
+		repo->workdir = git_buf_detach(parent_path);
+	else {
+		if (git_path_dirname_r(&worktree, repo->gitdir) < 0 ||
+		    git_path_to_dir(&worktree) < 0) {
+			error = -1;
+			goto cleanup;
+		}
+
+		repo->workdir = git_buf_detach(&worktree);
+	}
+
+	GITERR_CHECK_ALLOC(repo->workdir);
+cleanup:
+	git_buf_free(&path);
+	git_config_entry_free(ce);
+	return error;
+}
+
+/*
+ * This function returns furthest offset into path where a ceiling dir
+ * is found, so we can stop processing the path at that point.
+ *
+ * Note: converting this to use git_bufs instead of GIT_PATH_MAX buffers on
+ * the stack could remove directories name limits, but at the cost of doing
+ * repeated malloc/frees inside the loop below, so let's not do it now.
+ */
+static size_t find_ceiling_dir_offset(
+	const char *path,
+	const char *ceiling_directories)
+{
+	char buf[GIT_PATH_MAX + 1];
+	char buf2[GIT_PATH_MAX + 1];
+	const char *ceil, *sep;
+	size_t len, max_len = 0, min_len;
+
+	assert(path);
+
+	min_len = (size_t)(git_path_root(path) + 1);
+
+	if (ceiling_directories == NULL || min_len == 0)
+		return min_len;
+
+	for (sep = ceil = ceiling_directories; *sep; ceil = sep + 1) {
+		for (sep = ceil; *sep && *sep != GIT_PATH_LIST_SEPARATOR; sep++);
+		len = sep - ceil;
+
+		if (len == 0 || len >= sizeof(buf) || git_path_root(ceil) == -1)
+			continue;
+
+		strncpy(buf, ceil, len);
+		buf[len] = '\0';
+
+		if (p_realpath(buf, buf2) == NULL)
+			continue;
+
+		len = strlen(buf2);
+		if (len > 0 && buf2[len-1] == '/')
+			buf[--len] = '\0';
+
+		if (!strncmp(path, buf2, len) &&
+			(path[len] == '/' || !path[len]) &&
+			len > max_len)
+		{
+			max_len = len;
+		}
+	}
+
+	return (max_len <= min_len ? min_len : max_len);
+}
+
+/*
+ * Read the contents of `file_path` and set `path_out` to the repo dir that
+ * it points to.  Before calling, set `path_out` to the base directory that
+ * should be used if the contents of `file_path` are a relative path.
+ */
+static int read_gitfile(git_buf *path_out, const char *file_path)
+{
+	int     error = 0;
+	git_buf file = GIT_BUF_INIT;
+	size_t  prefix_len = strlen(GIT_FILE_CONTENT_PREFIX);
+
+	assert(path_out && file_path);
+
+	if (git_futils_readbuffer(&file, file_path) < 0)
+		return -1;
+
+	git_buf_rtrim(&file);
+	/* apparently on Windows, some people use backslashes in paths */
+	git_path_mkposix(file.ptr);
+
+	if (git_buf_len(&file) <= prefix_len ||
+		memcmp(git_buf_cstr(&file), GIT_FILE_CONTENT_PREFIX, prefix_len) != 0)
+	{
+		giterr_set(GITERR_REPOSITORY,
+			"the `.git` file at '%s' is malformed", file_path);
+		error = -1;
+	}
+	else if ((error = git_path_dirname_r(path_out, file_path)) >= 0) {
+		const char *gitlink = git_buf_cstr(&file) + prefix_len;
+		while (*gitlink && git__isspace(*gitlink)) gitlink++;
+
+		error = git_path_prettify_dir(
+			path_out, gitlink, git_buf_cstr(path_out));
+	}
+
+	git_buf_free(&file);
+	return error;
+}
+
+static int find_repo(
+	git_buf *gitdir_path,
+	git_buf *workdir_path,
+	git_buf *gitlink_path,
+	git_buf *commondir_path,
+	const char *start_path,
+	uint32_t flags,
+	const char *ceiling_dirs)
+{
+	int error;
+	git_buf path = GIT_BUF_INIT;
+	git_buf repo_link = GIT_BUF_INIT;
+	git_buf common_link = GIT_BUF_INIT;
+	struct stat st;
+	dev_t initial_device = 0;
+	int min_iterations;
+	bool in_dot_git;
+	size_t ceiling_offset = 0;
+
+	git_buf_clear(gitdir_path);
+
+	error = git_path_prettify(&path, start_path, NULL);
+	if (error < 0)
+		return error;
+
+	/* in_dot_git toggles each loop:
+	 * /a/b/c/.git, /a/b/c, /a/b/.git, /a/b, /a/.git, /a
+	 * With GIT_REPOSITORY_OPEN_BARE or GIT_REPOSITORY_OPEN_NO_DOTGIT, we
+	 * assume we started with /a/b/c.git and don't append .git the first
+	 * time through.
+	 * min_iterations indicates the number of iterations left before going
+	 * further counts as a search. */
+	if (flags & (GIT_REPOSITORY_OPEN_BARE | GIT_REPOSITORY_OPEN_NO_DOTGIT)) {
+		in_dot_git = true;
+		min_iterations = 1;
+	} else {
+		in_dot_git = false;
+		min_iterations = 2;
+	}
+
+	for (;;) {
+		if (!(flags & GIT_REPOSITORY_OPEN_NO_DOTGIT)) {
+			if (!in_dot_git) {
+				error = git_buf_joinpath(&path, path.ptr, DOT_GIT);
+				if (error < 0)
+					break;
+			}
+			in_dot_git = !in_dot_git;
+		}
+
+		if (p_stat(path.ptr, &st) == 0) {
+			/* check that we have not crossed device boundaries */
+			if (initial_device == 0)
+				initial_device = st.st_dev;
+			else if (st.st_dev != initial_device &&
+				 !(flags & GIT_REPOSITORY_OPEN_CROSS_FS))
+				break;
+
+			if (S_ISDIR(st.st_mode)) {
+				if (valid_repository_path(&path, &common_link)) {
+					git_path_to_dir(&path);
+					git_buf_set(gitdir_path, path.ptr, path.size);
+
+					if (gitlink_path)
+						git_buf_attach(gitlink_path,
+							git_worktree__read_link(path.ptr, GIT_GITDIR_FILE), 0);
+					if (commondir_path)
+						git_buf_swap(&common_link, commondir_path);
+
+					break;
+				}
+			}
+			else if (S_ISREG(st.st_mode) && git__suffixcmp(path.ptr, "/" DOT_GIT) == 0) {
+				error = read_gitfile(&repo_link, path.ptr);
+				if (error < 0)
+					break;
+				if (valid_repository_path(&repo_link, &common_link)) {
+					git_buf_swap(gitdir_path, &repo_link);
+
+					if (gitlink_path)
+						error = git_buf_put(gitlink_path, path.ptr, path.size);
+					if (commondir_path)
+						git_buf_swap(&common_link, commondir_path);
+				}
+				break;
+			}
+		}
+
+		/* Move up one directory. If we're in_dot_git, we'll search the
+		 * parent itself next. If we're !in_dot_git, we'll search .git
+		 * in the parent directory next (added at the top of the loop). */
+		if (git_path_dirname_r(&path, path.ptr) < 0) {
+			error = -1;
+			break;
+		}
+
+		/* Once we've checked the directory (and .git if applicable),
+		 * find the ceiling for a search. */
+		if (min_iterations && (--min_iterations == 0))
+			ceiling_offset = find_ceiling_dir_offset(path.ptr, ceiling_dirs);
+
+		/* Check if we should stop searching here. */
+		if (min_iterations == 0
+		    && (path.ptr[ceiling_offset] == 0
+			|| (flags & GIT_REPOSITORY_OPEN_NO_SEARCH)))
+			break;
+	}
+
+	if (!error && workdir_path && !(flags & GIT_REPOSITORY_OPEN_BARE)) {
+		if (!git_buf_len(gitdir_path))
+			git_buf_clear(workdir_path);
+		else {
+			git_path_dirname_r(workdir_path, path.ptr);
+			git_path_to_dir(workdir_path);
+		}
+		if (git_buf_oom(workdir_path))
+			return -1;
+	}
+
+	/* If we didn't find the repository, and we don't have any other error
+	 * to report, report that. */
+	if (!git_buf_len(gitdir_path) && !error) {
+		giterr_set(GITERR_REPOSITORY,
+			"could not find repository from '%s'", start_path);
+		error = GIT_ENOTFOUND;
+	}
+
+	git_buf_free(&path);
+	git_buf_free(&repo_link);
+	git_buf_free(&common_link);
+	return error;
+}
+
+int git_repository_open_bare(
+	git_repository **repo_ptr,
+	const char *bare_path)
+{
+	int error;
+	git_buf path = GIT_BUF_INIT, common_path = GIT_BUF_INIT;
+	git_repository *repo = NULL;
+
+	if ((error = git_path_prettify_dir(&path, bare_path, NULL)) < 0)
+		return error;
+
+	if (!valid_repository_path(&path, &common_path)) {
+		git_buf_free(&path);
+		git_buf_free(&common_path);
+		giterr_set(GITERR_REPOSITORY, "path is not a repository: %s", bare_path);
+		return GIT_ENOTFOUND;
+	}
+
+	repo = repository_alloc();
+	GITERR_CHECK_ALLOC(repo);
+
+	repo->gitdir = git_buf_detach(&path);
+	GITERR_CHECK_ALLOC(repo->gitdir);
+	repo->commondir = git_buf_detach(&common_path);
+	GITERR_CHECK_ALLOC(repo->commondir);
+
+	/* of course we're bare! */
+	repo->is_bare = 1;
+	repo->is_worktree = 0;
+	repo->workdir = NULL;
+
+	*repo_ptr = repo;
+	return 0;
+}
+
+static int _git_repository_open_ext_from_env(
+	git_repository **out,
+	const char *start_path)
+{
+	git_repository *repo = NULL;
+	git_index *index = NULL;
+	git_odb *odb = NULL;
+	git_buf dir_buf = GIT_BUF_INIT;
+	git_buf ceiling_dirs_buf = GIT_BUF_INIT;
+	git_buf across_fs_buf = GIT_BUF_INIT;
+	git_buf index_file_buf = GIT_BUF_INIT;
+	git_buf namespace_buf = GIT_BUF_INIT;
+	git_buf object_dir_buf = GIT_BUF_INIT;
+	git_buf alts_buf = GIT_BUF_INIT;
+	git_buf work_tree_buf = GIT_BUF_INIT;
+	git_buf common_dir_buf = GIT_BUF_INIT;
+	const char *ceiling_dirs = NULL;
+	unsigned flags = 0;
+	int error;
+
+	if (!start_path) {
+		error = git__getenv(&dir_buf, "GIT_DIR");
+		if (error == GIT_ENOTFOUND) {
+			giterr_clear();
+			start_path = ".";
+		} else if (error < 0)
+			goto error;
+		else {
+			start_path = git_buf_cstr(&dir_buf);
+			flags |= GIT_REPOSITORY_OPEN_NO_SEARCH;
+			flags |= GIT_REPOSITORY_OPEN_NO_DOTGIT;
+		}
+	}
+
+	error = git__getenv(&ceiling_dirs_buf, "GIT_CEILING_DIRECTORIES");
+	if (error == GIT_ENOTFOUND)
+		giterr_clear();
+	else if (error < 0)
+		goto error;
+	else
+		ceiling_dirs = git_buf_cstr(&ceiling_dirs_buf);
+
+	error = git__getenv(&across_fs_buf, "GIT_DISCOVERY_ACROSS_FILESYSTEM");
+	if (error == GIT_ENOTFOUND)
+		giterr_clear();
+	else if (error < 0)
+		goto error;
+	else {
+		int across_fs = 0;
+		error = git_config_parse_bool(&across_fs, git_buf_cstr(&across_fs_buf));
+		if (error < 0)
+			goto error;
+		if (across_fs)
+			flags |= GIT_REPOSITORY_OPEN_CROSS_FS;
+	}
+
+	error = git__getenv(&index_file_buf, "GIT_INDEX_FILE");
+	if (error == GIT_ENOTFOUND)
+		giterr_clear();
+	else if (error < 0)
+		goto error;
+	else {
+		error = git_index_open(&index, git_buf_cstr(&index_file_buf));
+		if (error < 0)
+			goto error;
+	}
+
+	error = git__getenv(&namespace_buf, "GIT_NAMESPACE");
+	if (error == GIT_ENOTFOUND)
+		giterr_clear();
+	else if (error < 0)
+		goto error;
+
+	error = git__getenv(&object_dir_buf, "GIT_OBJECT_DIRECTORY");
+	if (error == GIT_ENOTFOUND)
+		giterr_clear();
+	else if (error < 0)
+		goto error;
+	else {
+		error = git_odb_open(&odb, git_buf_cstr(&object_dir_buf));
+		if (error < 0)
+			goto error;
+	}
+
+	error = git__getenv(&work_tree_buf, "GIT_WORK_TREE");
+	if (error == GIT_ENOTFOUND)
+		giterr_clear();
+	else if (error < 0)
+		goto error;
+	else {
+		giterr_set(GITERR_INVALID, "GIT_WORK_TREE unimplemented");
+		error = GIT_ERROR;
+		goto error;
+	}
+
+	error = git__getenv(&work_tree_buf, "GIT_COMMON_DIR");
+	if (error == GIT_ENOTFOUND)
+		giterr_clear();
+	else if (error < 0)
+		goto error;
+	else {
+		giterr_set(GITERR_INVALID, "GIT_COMMON_DIR unimplemented");
+		error = GIT_ERROR;
+		goto error;
+	}
+
+	error = git_repository_open_ext(&repo, start_path, flags, ceiling_dirs);
+	if (error < 0)
+		goto error;
+
+	if (odb)
+		git_repository_set_odb(repo, odb);
+
+	error = git__getenv(&alts_buf, "GIT_ALTERNATE_OBJECT_DIRECTORIES");
+	if (error == GIT_ENOTFOUND) {
+		giterr_clear();
+		error = 0;
+	} else if (error < 0)
+		goto error;
+        else {
+		const char *end;
+		char *alt, *sep;
+		if (!odb) {
+			error = git_repository_odb(&odb, repo);
+			if (error < 0)
+				goto error;
+		}
+
+		end = git_buf_cstr(&alts_buf) + git_buf_len(&alts_buf);
+		for (sep = alt = alts_buf.ptr; sep != end; alt = sep+1) {
+			for (sep = alt; *sep && *sep != GIT_PATH_LIST_SEPARATOR; sep++)
+				;
+			if (*sep)
+				*sep = '\0';
+			error = git_odb_add_disk_alternate(odb, alt);
+			if (error < 0)
+				goto error;
+		}
+	}
+
+	if (git_buf_len(&namespace_buf)) {
+		error = git_repository_set_namespace(repo, git_buf_cstr(&namespace_buf));
+		if (error < 0)
+			goto error;
+	}
+
+	git_repository_set_index(repo, index);
+
+	if (out) {
+		*out = repo;
+		goto success;
+	}
+error:
+	git_repository_free(repo);
+success:
+	git_odb_free(odb);
+	git_index_free(index);
+	git_buf_free(&common_dir_buf);
+	git_buf_free(&work_tree_buf);
+	git_buf_free(&alts_buf);
+	git_buf_free(&object_dir_buf);
+	git_buf_free(&namespace_buf);
+	git_buf_free(&index_file_buf);
+	git_buf_free(&across_fs_buf);
+	git_buf_free(&ceiling_dirs_buf);
+	git_buf_free(&dir_buf);
+	return error;
+}
+
+static int repo_is_worktree(unsigned *out, const git_repository *repo)
+{
+	git_buf gitdir_link = GIT_BUF_INIT;
+	int error;
+
+	/* Worktrees cannot have the same commondir and gitdir */
+	if (repo->commondir && repo->gitdir
+	    && !strcmp(repo->commondir, repo->gitdir)) {
+		*out = 0;
+		return 0;
+	}
+
+	if ((error = git_buf_joinpath(&gitdir_link, repo->gitdir, "gitdir")) < 0)
+		return -1;
+
+	/* A 'gitdir' file inside a git directory is currently
+	 * only used when the repository is a working tree. */
+	*out = !!git_path_exists(gitdir_link.ptr);
+
+	git_buf_free(&gitdir_link);
+	return error;
+}
+
+int git_repository_open_ext(
+	git_repository **repo_ptr,
+	const char *start_path,
+	unsigned int flags,
+	const char *ceiling_dirs)
+{
+	int error;
+	unsigned is_worktree;
+	git_buf gitdir = GIT_BUF_INIT, workdir = GIT_BUF_INIT,
+		gitlink = GIT_BUF_INIT, commondir = GIT_BUF_INIT;
+	git_repository *repo;
+	git_config *config = NULL;
+
+	if (flags & GIT_REPOSITORY_OPEN_FROM_ENV)
+		return _git_repository_open_ext_from_env(repo_ptr, start_path);
+
+	if (repo_ptr)
+		*repo_ptr = NULL;
+
+	error = find_repo(
+		&gitdir, &workdir, &gitlink, &commondir, start_path, flags, ceiling_dirs);
+
+	if (error < 0 || !repo_ptr)
+		return error;
+
+	repo = repository_alloc();
+	GITERR_CHECK_ALLOC(repo);
+
+	repo->gitdir = git_buf_detach(&gitdir);
+	GITERR_CHECK_ALLOC(repo->gitdir);
+
+	if (gitlink.size) {
+		repo->gitlink = git_buf_detach(&gitlink);
+		GITERR_CHECK_ALLOC(repo->gitlink);
+	}
+	if (commondir.size) {
+		repo->commondir = git_buf_detach(&commondir);
+		GITERR_CHECK_ALLOC(repo->commondir);
+	}
+
+	if ((error = repo_is_worktree(&is_worktree, repo)) < 0)
+		goto cleanup;
+	repo->is_worktree = is_worktree;
+
+	/*
+	 * We'd like to have the config, but git doesn't particularly
+	 * care if it's not there, so we need to deal with that.
+	 */
+
+	error = git_repository_config_snapshot(&config, repo);
+	if (error < 0 && error != GIT_ENOTFOUND)
+		goto cleanup;
+
+	if (config && (error = check_repositoryformatversion(config)) < 0)
+		goto cleanup;
+
+	if ((flags & GIT_REPOSITORY_OPEN_BARE) != 0)
+		repo->is_bare = 1;
+	else {
+
+		if (config &&
+		    ((error = load_config_data(repo, config)) < 0 ||
+		     (error = load_workdir(repo, config, &workdir)) < 0))
+			goto cleanup;
+	}
+
+cleanup:
+	git_buf_free(&gitdir);
+	git_buf_free(&workdir);
+	git_config_free(config);
+
+	if (error < 0)
+		git_repository_free(repo);
+	else
+		*repo_ptr = repo;
+
+	return error;
+}
+
+int git_repository_open(git_repository **repo_out, const char *path)
+{
+	return git_repository_open_ext(
+		repo_out, path, GIT_REPOSITORY_OPEN_NO_SEARCH, NULL);
+}
+
+int git_repository_open_from_worktree(git_repository **repo_out, git_worktree *wt)
+{
+	git_buf path = GIT_BUF_INIT;
+	git_repository *repo = NULL;
+	int len, err;
+
+	assert(repo_out && wt);
+
+	*repo_out = NULL;
+	len = strlen(wt->gitlink_path);
+
+	if (len <= 4 || strcasecmp(wt->gitlink_path + len - 4, ".git")) {
+		err = -1;
+		goto out;
+	}
+
+	if ((err = git_buf_set(&path, wt->gitlink_path, len - 4)) < 0)
+		goto out;
+
+	if ((err = git_repository_open(&repo, path.ptr)) < 0)
+		goto out;
+
+	*repo_out = repo;
+
+out:
+	git_buf_free(&path);
+
+	return err;
+}
+
+int git_repository_wrap_odb(git_repository **repo_out, git_odb *odb)
+{
+	git_repository *repo;
+
+	repo = repository_alloc();
+	GITERR_CHECK_ALLOC(repo);
+
+	git_repository_set_odb(repo, odb);
+	*repo_out = repo;
+
+	return 0;
+}
+
+int git_repository_discover(
+	git_buf *out,
+	const char *start_path,
+	int across_fs,
+	const char *ceiling_dirs)
+{
+	uint32_t flags = across_fs ? GIT_REPOSITORY_OPEN_CROSS_FS : 0;
+
+	assert(start_path);
+
+	git_buf_sanitize(out);
+
+	return find_repo(out, NULL, NULL, NULL, start_path, flags, ceiling_dirs);
+}
+
+static int load_config(
+	git_config **out,
+	git_repository *repo,
+	const char *global_config_path,
+	const char *xdg_config_path,
+	const char *system_config_path,
+	const char *programdata_path)
+{
+	int error;
+	git_buf config_path = GIT_BUF_INIT;
+	git_config *cfg = NULL;
+
+	assert(repo && out);
+
+	if ((error = git_config_new(&cfg)) < 0)
+		return error;
+
+	if ((error = git_repository_item_path(&config_path, repo, GIT_REPOSITORY_ITEM_CONFIG)) == 0)
+		error = git_config_add_file_ondisk(cfg, config_path.ptr, GIT_CONFIG_LEVEL_LOCAL, repo, 0);
+
+	if (error && error != GIT_ENOTFOUND)
+		goto on_error;
+
+	git_buf_free(&config_path);
+
+	if (global_config_path != NULL &&
+		(error = git_config_add_file_ondisk(
+			cfg, global_config_path, GIT_CONFIG_LEVEL_GLOBAL, repo, 0)) < 0 &&
+		error != GIT_ENOTFOUND)
+		goto on_error;
+
+	if (xdg_config_path != NULL &&
+		(error = git_config_add_file_ondisk(
+			cfg, xdg_config_path, GIT_CONFIG_LEVEL_XDG, repo, 0)) < 0 &&
+		error != GIT_ENOTFOUND)
+		goto on_error;
+
+	if (system_config_path != NULL &&
+		(error = git_config_add_file_ondisk(
+			cfg, system_config_path, GIT_CONFIG_LEVEL_SYSTEM, repo, 0)) < 0 &&
+		error != GIT_ENOTFOUND)
+		goto on_error;
+
+	if (programdata_path != NULL &&
+		(error = git_config_add_file_ondisk(
+			cfg, programdata_path, GIT_CONFIG_LEVEL_PROGRAMDATA, repo, 0)) < 0 &&
+		error != GIT_ENOTFOUND)
+		goto on_error;
+
+	giterr_clear(); /* clear any lingering ENOTFOUND errors */
+
+	*out = cfg;
+	return 0;
+
+on_error:
+	git_buf_free(&config_path);
+	git_config_free(cfg);
+	*out = NULL;
+	return error;
+}
+
+static const char *path_unless_empty(git_buf *buf)
+{
+	return git_buf_len(buf) > 0 ? git_buf_cstr(buf) : NULL;
+}
+
+int git_repository_config__weakptr(git_config **out, git_repository *repo)
+{
+	int error = 0;
+
+	if (repo->_config == NULL) {
+		git_buf global_buf = GIT_BUF_INIT;
+		git_buf xdg_buf = GIT_BUF_INIT;
+		git_buf system_buf = GIT_BUF_INIT;
+		git_buf programdata_buf = GIT_BUF_INIT;
+		git_config *config;
+
+		git_config_find_global(&global_buf);
+		git_config_find_xdg(&xdg_buf);
+		git_config_find_system(&system_buf);
+		git_config_find_programdata(&programdata_buf);
+
+		/* If there is no global file, open a backend for it anyway */
+		if (git_buf_len(&global_buf) == 0)
+			git_config__global_location(&global_buf);
+
+		error = load_config(
+			&config, repo,
+			path_unless_empty(&global_buf),
+			path_unless_empty(&xdg_buf),
+			path_unless_empty(&system_buf),
+			path_unless_empty(&programdata_buf));
+		if (!error) {
+			GIT_REFCOUNT_OWN(config, repo);
+
+			config = git__compare_and_swap(&repo->_config, NULL, config);
+			if (config != NULL) {
+				GIT_REFCOUNT_OWN(config, NULL);
+				git_config_free(config);
+			}
+		}
+
+		git_buf_free(&global_buf);
+		git_buf_free(&xdg_buf);
+		git_buf_free(&system_buf);
+		git_buf_free(&programdata_buf);
+	}
+
+	*out = repo->_config;
+	return error;
+}
+
+int git_repository_config(git_config **out, git_repository *repo)
+{
+	if (git_repository_config__weakptr(out, repo) < 0)
+		return -1;
+
+	GIT_REFCOUNT_INC(*out);
+	return 0;
+}
+
+int git_repository_config_snapshot(git_config **out, git_repository *repo)
+{
+	int error;
+	git_config *weak;
+
+	if ((error = git_repository_config__weakptr(&weak, repo)) < 0)
+		return error;
+
+	return git_config_snapshot(out, weak);
+}
+
+void git_repository_set_config(git_repository *repo, git_config *config)
+{
+	assert(repo && config);
+	set_config(repo, config);
+}
+
+int git_repository_odb__weakptr(git_odb **out, git_repository *repo)
+{
+	int error = 0;
+
+	assert(repo && out);
+
+	if (repo->_odb == NULL) {
+		git_buf odb_path = GIT_BUF_INIT;
+		git_odb *odb;
+
+		if ((error = git_repository_item_path(&odb_path, repo,
+				GIT_REPOSITORY_ITEM_OBJECTS)) < 0 ||
+			(error = git_odb_new(&odb)) < 0)
+			return error;
+
+		GIT_REFCOUNT_OWN(odb, repo);
+
+		if ((error = git_odb__set_caps(odb, GIT_ODB_CAP_FROM_OWNER)) < 0 ||
+			(error = git_odb__add_default_backends(odb, odb_path.ptr, 0, 0)) < 0) {
+			git_odb_free(odb);
+			return error;
+		}
+
+		odb = git__compare_and_swap(&repo->_odb, NULL, odb);
+		if (odb != NULL) {
+			GIT_REFCOUNT_OWN(odb, NULL);
+			git_odb_free(odb);
+		}
+
+		git_buf_free(&odb_path);
+	}
+
+	*out = repo->_odb;
+	return error;
+}
+
+int git_repository_odb(git_odb **out, git_repository *repo)
+{
+	if (git_repository_odb__weakptr(out, repo) < 0)
+		return -1;
+
+	GIT_REFCOUNT_INC(*out);
+	return 0;
+}
+
+void git_repository_set_odb(git_repository *repo, git_odb *odb)
+{
+	assert(repo && odb);
+	set_odb(repo, odb);
+}
+
+int git_repository_refdb__weakptr(git_refdb **out, git_repository *repo)
+{
+	int error = 0;
+
+	assert(out && repo);
+
+	if (repo->_refdb == NULL) {
+		git_refdb *refdb;
+
+		error = git_refdb_open(&refdb, repo);
+		if (!error) {
+			GIT_REFCOUNT_OWN(refdb, repo);
+
+			refdb = git__compare_and_swap(&repo->_refdb, NULL, refdb);
+			if (refdb != NULL) {
+				GIT_REFCOUNT_OWN(refdb, NULL);
+				git_refdb_free(refdb);
+			}
+		}
+	}
+
+	*out = repo->_refdb;
+	return error;
+}
+
+int git_repository_refdb(git_refdb **out, git_repository *repo)
+{
+	if (git_repository_refdb__weakptr(out, repo) < 0)
+		return -1;
+
+	GIT_REFCOUNT_INC(*out);
+	return 0;
+}
+
+void git_repository_set_refdb(git_repository *repo, git_refdb *refdb)
+{
+	assert(repo && refdb);
+	set_refdb(repo, refdb);
+}
+
+int git_repository_index__weakptr(git_index **out, git_repository *repo)
+{
+	int error = 0;
+
+	assert(out && repo);
+
+	if (repo->_index == NULL) {
+		git_buf index_path = GIT_BUF_INIT;
+		git_index *index;
+
+		if ((error = git_buf_joinpath(&index_path, repo->gitdir, GIT_INDEX_FILE)) < 0)
+			return error;
+
+		error = git_index_open(&index, index_path.ptr);
+		if (!error) {
+			GIT_REFCOUNT_OWN(index, repo);
+
+			index = git__compare_and_swap(&repo->_index, NULL, index);
+			if (index != NULL) {
+				GIT_REFCOUNT_OWN(index, NULL);
+				git_index_free(index);
+			}
+
+			error = git_index_set_caps(repo->_index, GIT_INDEXCAP_FROM_OWNER);
+		}
+
+		git_buf_free(&index_path);
+	}
+
+	*out = repo->_index;
+	return error;
+}
+
+int git_repository_index(git_index **out, git_repository *repo)
+{
+	if (git_repository_index__weakptr(out, repo) < 0)
+		return -1;
+
+	GIT_REFCOUNT_INC(*out);
+	return 0;
+}
+
+void git_repository_set_index(git_repository *repo, git_index *index)
+{
+	assert(repo);
+	set_index(repo, index);
+}
+
+int git_repository_set_namespace(git_repository *repo, const char *namespace)
+{
+	git__free(repo->namespace);
+
+	if (namespace == NULL) {
+		repo->namespace = NULL;
+		return 0;
+	}
+
+	return (repo->namespace = git__strdup(namespace)) ? 0 : -1;
+}
+
+const char *git_repository_get_namespace(git_repository *repo)
+{
+	return repo->namespace;
+}
+
+#ifdef GIT_WIN32
+static int reserved_names_add8dot3(git_repository *repo, const char *path)
+{
+	char *name = git_win32_path_8dot3_name(path);
+	const char *def = GIT_DIR_SHORTNAME;
+	const char *def_dot_git = DOT_GIT;
+	size_t name_len, def_len = CONST_STRLEN(GIT_DIR_SHORTNAME);
+	size_t def_dot_git_len = CONST_STRLEN(DOT_GIT);
+	git_buf *buf;
+
+	if (!name)
+		return 0;
+
+	name_len = strlen(name);
+
+	if ((name_len == def_len && memcmp(name, def, def_len) == 0) ||
+		(name_len == def_dot_git_len && memcmp(name, def_dot_git, def_dot_git_len) == 0)) {
+		git__free(name);
+		return 0;
+	}
+
+	if ((buf = git_array_alloc(repo->reserved_names)) == NULL)
+		return -1;
+
+	git_buf_attach(buf, name, name_len);
+	return true;
+}
+
+bool git_repository__reserved_names(
+	git_buf **out, size_t *outlen, git_repository *repo, bool include_ntfs)
+{
+	GIT_UNUSED(include_ntfs);
+
+	if (repo->reserved_names.size == 0) {
+		git_buf *buf;
+		size_t i;
+
+		/* Add the static defaults */
+		for (i = 0; i < git_repository__reserved_names_win32_len; i++) {
+			if ((buf = git_array_alloc(repo->reserved_names)) == NULL)
+				goto on_error;
+
+			buf->ptr = git_repository__reserved_names_win32[i].ptr;
+			buf->size = git_repository__reserved_names_win32[i].size;
+		}
+
+		/* Try to add any repo-specific reserved names - the gitlink file
+		 * within a submodule or the repository (if the repository directory
+		 * is beneath the workdir).  These are typically `.git`, but should
+		 * be protected in case they are not.  Note, repo and workdir paths
+		 * are always prettified to end in `/`, so a prefixcmp is safe.
+		 */
+		if (!repo->is_bare) {
+			int (*prefixcmp)(const char *, const char *);
+			int error, ignorecase;
+
+			error = git_repository__cvar(
+				&ignorecase, repo, GIT_CVAR_IGNORECASE);
+			prefixcmp = (error || ignorecase) ? git__prefixcmp_icase :
+				git__prefixcmp;
+
+			if (repo->gitlink &&
+				reserved_names_add8dot3(repo, repo->gitlink) < 0)
+				goto on_error;
+
+			if (repo->gitdir &&
+				prefixcmp(repo->gitdir, repo->workdir) == 0 &&
+				reserved_names_add8dot3(repo, repo->gitdir) < 0)
+				goto on_error;
+		}
+	}
+
+	*out = repo->reserved_names.ptr;
+	*outlen = repo->reserved_names.size;
+
+	return true;
+
+	/* Always give good defaults, even on OOM */
+on_error:
+	*out = git_repository__reserved_names_win32;
+	*outlen = git_repository__reserved_names_win32_len;
+
+	return false;
+}
+#else
+bool git_repository__reserved_names(
+	git_buf **out, size_t *outlen, git_repository *repo, bool include_ntfs)
+{
+	GIT_UNUSED(repo);
+
+	if (include_ntfs) {
+		*out = git_repository__reserved_names_win32;
+		*outlen = git_repository__reserved_names_win32_len;
+	} else {
+		*out = git_repository__reserved_names_posix;
+		*outlen = git_repository__reserved_names_posix_len;
+	}
+
+	return true;
+}
+#endif
+
+static int check_repositoryformatversion(git_config *config)
+{
+	int version, error;
+
+	error = git_config_get_int32(&version, config, "core.repositoryformatversion");
+	/* git ignores this if the config variable isn't there */
+	if (error == GIT_ENOTFOUND)
+		return 0;
+
+	if (error < 0)
+		return -1;
+
+	if (GIT_REPO_VERSION < version) {
+		giterr_set(GITERR_REPOSITORY,
+			"unsupported repository version %d. Only versions up to %d are supported.",
+			version, GIT_REPO_VERSION);
+		return -1;
+	}
+
+	return 0;
+}
+
+int git_repository_create_head(const char *git_dir, const char *ref_name)
+{
+	git_buf ref_path = GIT_BUF_INIT;
+	git_filebuf ref = GIT_FILEBUF_INIT;
+	const char *fmt;
+
+	if (git_buf_joinpath(&ref_path, git_dir, GIT_HEAD_FILE) < 0 ||
+		git_filebuf_open(&ref, ref_path.ptr, 0, GIT_REFS_FILE_MODE) < 0)
+		goto fail;
+
+	if (!ref_name)
+		ref_name = GIT_BRANCH_MASTER;
+
+	if (git__prefixcmp(ref_name, GIT_REFS_DIR) == 0)
+		fmt = "ref: %s\n";
+	else
+		fmt = "ref: " GIT_REFS_HEADS_DIR "%s\n";
+
+	if (git_filebuf_printf(&ref, fmt, ref_name) < 0 ||
+		git_filebuf_commit(&ref) < 0)
+		goto fail;
+
+	git_buf_free(&ref_path);
+	return 0;
+
+fail:
+	git_buf_free(&ref_path);
+	git_filebuf_cleanup(&ref);
+	return -1;
+}
+
+static bool is_chmod_supported(const char *file_path)
+{
+	struct stat st1, st2;
+
+	if (p_stat(file_path, &st1) < 0)
+		return false;
+
+	if (p_chmod(file_path, st1.st_mode ^ S_IXUSR) < 0)
+		return false;
+
+	if (p_stat(file_path, &st2) < 0)
+		return false;
+
+	return (st1.st_mode != st2.st_mode);
+}
+
+static bool is_filesystem_case_insensitive(const char *gitdir_path)
+{
+	git_buf path = GIT_BUF_INIT;
+	int is_insensitive = -1;
+
+	if (!git_buf_joinpath(&path, gitdir_path, "CoNfIg"))
+		is_insensitive = git_path_exists(git_buf_cstr(&path));
+
+	git_buf_free(&path);
+	return is_insensitive;
+}
+
+static bool are_symlinks_supported(const char *wd_path)
+{
+	git_buf path = GIT_BUF_INIT;
+	int fd;
+	struct stat st;
+	int symlinks_supported = -1;
+
+	if ((fd = git_futils_mktmp(&path, wd_path, 0666)) < 0 ||
+		p_close(fd) < 0 ||
+		p_unlink(path.ptr) < 0 ||
+		p_symlink("testing", path.ptr) < 0 ||
+		p_lstat(path.ptr, &st) < 0)
+		symlinks_supported = false;
+	else
+		symlinks_supported = (S_ISLNK(st.st_mode) != 0);
+
+	(void)p_unlink(path.ptr);
+	git_buf_free(&path);
+
+	return symlinks_supported;
+}
+
+static int create_empty_file(const char *path, mode_t mode)
+{
+	int fd;
+
+	if ((fd = p_creat(path, mode)) < 0) {
+		giterr_set(GITERR_OS, "error while creating '%s'", path);
+		return -1;
+	}
+
+	if (p_close(fd) < 0) {
+		giterr_set(GITERR_OS, "error while closing '%s'", path);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int repo_local_config(
+	git_config **out,
+	git_buf *config_dir,
+	git_repository *repo,
+	const char *repo_dir)
+{
+	int error = 0;
+	git_config *parent;
+	const char *cfg_path;
+
+	if (git_buf_joinpath(config_dir, repo_dir, GIT_CONFIG_FILENAME_INREPO) < 0)
+		return -1;
+	cfg_path = git_buf_cstr(config_dir);
+
+	/* make LOCAL config if missing */
+	if (!git_path_isfile(cfg_path) &&
+		(error = create_empty_file(cfg_path, GIT_CONFIG_FILE_MODE)) < 0)
+		return error;
+
+	/* if no repo, just open that file directly */
+	if (!repo)
+		return git_config_open_ondisk(out, cfg_path);
+
+	/* otherwise, open parent config and get that level */
+	if ((error = git_repository_config__weakptr(&parent, repo)) < 0)
+		return error;
+
+	if (git_config_open_level(out, parent, GIT_CONFIG_LEVEL_LOCAL) < 0) {
+		giterr_clear();
+
+		if (!(error = git_config_add_file_ondisk(
+				parent, cfg_path, GIT_CONFIG_LEVEL_LOCAL, repo, false)))
+			error = git_config_open_level(out, parent, GIT_CONFIG_LEVEL_LOCAL);
+	}
+
+	git_config_free(parent);
+
+	return error;
+}
+
+static int repo_init_fs_configs(
+	git_config *cfg,
+	const char *cfg_path,
+	const char *repo_dir,
+	const char *work_dir,
+	bool update_ignorecase)
+{
+	int error = 0;
+
+	if (!work_dir)
+		work_dir = repo_dir;
+
+	if ((error = git_config_set_bool(
+			cfg, "core.filemode", is_chmod_supported(cfg_path))) < 0)
+		return error;
+
+	if (!are_symlinks_supported(work_dir)) {
+		if ((error = git_config_set_bool(cfg, "core.symlinks", false)) < 0)
+			return error;
+	} else if (git_config_delete_entry(cfg, "core.symlinks") < 0)
+		giterr_clear();
+
+	if (update_ignorecase) {
+		if (is_filesystem_case_insensitive(repo_dir)) {
+			if ((error = git_config_set_bool(cfg, "core.ignorecase", true)) < 0)
+				return error;
+		} else if (git_config_delete_entry(cfg, "core.ignorecase") < 0)
+			giterr_clear();
+	}
+
+#ifdef GIT_USE_ICONV
+	if ((error = git_config_set_bool(
+			cfg, "core.precomposeunicode",
+			git_path_does_fs_decompose_unicode(work_dir))) < 0)
+		return error;
+	/* on non-iconv platforms, don't even set core.precomposeunicode */
+#endif
+
+	return 0;
+}
+
+static int repo_init_config(
+	const char *repo_dir,
+	const char *work_dir,
+	uint32_t flags,
+	uint32_t mode)
+{
+	int error = 0;
+	git_buf cfg_path = GIT_BUF_INIT, worktree_path = GIT_BUF_INIT;
+	git_config *config = NULL;
+	bool is_bare = ((flags & GIT_REPOSITORY_INIT_BARE) != 0);
+	bool is_reinit = ((flags & GIT_REPOSITORY_INIT__IS_REINIT) != 0);
+
+	if ((error = repo_local_config(&config, &cfg_path, NULL, repo_dir)) < 0)
+		goto cleanup;
+
+	if (is_reinit && (error = check_repositoryformatversion(config)) < 0)
+		goto cleanup;
+
+#define SET_REPO_CONFIG(TYPE, NAME, VAL) do { \
+	if ((error = git_config_set_##TYPE(config, NAME, VAL)) < 0) \
+		goto cleanup; } while (0)
+
+	SET_REPO_CONFIG(bool, "core.bare", is_bare);
+	SET_REPO_CONFIG(int32, "core.repositoryformatversion", GIT_REPO_VERSION);
+
+	if ((error = repo_init_fs_configs(
+			config, cfg_path.ptr, repo_dir, work_dir, !is_reinit)) < 0)
+		goto cleanup;
+
+	if (!is_bare) {
+		SET_REPO_CONFIG(bool, "core.logallrefupdates", true);
+
+		if (!(flags & GIT_REPOSITORY_INIT__NATURAL_WD)) {
+			if ((error = git_buf_sets(&worktree_path, work_dir)) < 0)
+				goto cleanup;
+
+			if ((flags & GIT_REPOSITORY_INIT_RELATIVE_GITLINK))
+				if ((error = git_path_make_relative(&worktree_path, repo_dir)) < 0)
+					goto cleanup;
+
+			SET_REPO_CONFIG(string, "core.worktree", worktree_path.ptr);
+		} else if (is_reinit) {
+			if (git_config_delete_entry(config, "core.worktree") < 0)
+				giterr_clear();
+		}
+	}
+
+	if (mode == GIT_REPOSITORY_INIT_SHARED_GROUP) {
+		SET_REPO_CONFIG(int32, "core.sharedrepository", 1);
+		SET_REPO_CONFIG(bool, "receive.denyNonFastforwards", true);
+	}
+	else if (mode == GIT_REPOSITORY_INIT_SHARED_ALL) {
+		SET_REPO_CONFIG(int32, "core.sharedrepository", 2);
+		SET_REPO_CONFIG(bool, "receive.denyNonFastforwards", true);
+	}
+
+cleanup:
+	git_buf_free(&cfg_path);
+	git_buf_free(&worktree_path);
+	git_config_free(config);
+
+	return error;
+}
+
+static int repo_reinit_submodule_fs(git_submodule *sm, const char *n, void *p)
+{
+	git_repository *smrepo = NULL;
+	GIT_UNUSED(n); GIT_UNUSED(p);
+
+	if (git_submodule_open(&smrepo, sm) < 0 ||
+		git_repository_reinit_filesystem(smrepo, true) < 0)
+		giterr_clear();
+	git_repository_free(smrepo);
+
+	return 0;
+}
+
+int git_repository_reinit_filesystem(git_repository *repo, int recurse)
+{
+	int error = 0;
+	git_buf path = GIT_BUF_INIT;
+	git_config *config = NULL;
+	const char *repo_dir = git_repository_path(repo);
+
+	if (!(error = repo_local_config(&config, &path, repo, repo_dir)))
+		error = repo_init_fs_configs(
+			config, path.ptr, repo_dir, git_repository_workdir(repo), true);
+
+	git_config_free(config);
+	git_buf_free(&path);
+
+	git_repository__cvar_cache_clear(repo);
+
+	if (!repo->is_bare && recurse)
+		(void)git_submodule_foreach(repo, repo_reinit_submodule_fs, NULL);
+
+	return error;
+}
+
+static int repo_write_template(
+	const char *git_dir,
+	bool allow_overwrite,
+	const char *file,
+	mode_t mode,
+	bool hidden,
+	const char *content)
+{
+	git_buf path = GIT_BUF_INIT;
+	int fd, error = 0, flags;
+
+	if (git_buf_joinpath(&path, git_dir, file) < 0)
+		return -1;
+
+	if (allow_overwrite)
+		flags = O_WRONLY | O_CREAT | O_TRUNC;
+	else
+		flags = O_WRONLY | O_CREAT | O_EXCL;
+
+	fd = p_open(git_buf_cstr(&path), flags, mode);
+
+	if (fd >= 0) {
+		error = p_write(fd, content, strlen(content));
+
+		p_close(fd);
+	}
+	else if (errno != EEXIST)
+		error = fd;
+
+#ifdef GIT_WIN32
+	if (!error && hidden) {
+		if (git_win32__set_hidden(path.ptr, true) < 0)
+			error = -1;
+	}
+#else
+	GIT_UNUSED(hidden);
+#endif
+
+	git_buf_free(&path);
+
+	if (error)
+		giterr_set(GITERR_OS,
+			"failed to initialize repository with template '%s'", file);
+
+	return error;
+}
+
+static int repo_write_gitlink(
+	const char *in_dir, const char *to_repo, bool use_relative_path)
+{
+	int error;
+	git_buf buf = GIT_BUF_INIT;
+	git_buf path_to_repo = GIT_BUF_INIT;
+	struct stat st;
+
+	git_path_dirname_r(&buf, to_repo);
+	git_path_to_dir(&buf);
+	if (git_buf_oom(&buf))
+		return -1;
+
+	/* don't write gitlink to natural workdir */
+	if (git__suffixcmp(to_repo, "/" DOT_GIT "/") == 0 &&
+		strcmp(in_dir, buf.ptr) == 0)
+	{
+		error = GIT_PASSTHROUGH;
+		goto cleanup;
+	}
+
+	if ((error = git_buf_joinpath(&buf, in_dir, DOT_GIT)) < 0)
+		goto cleanup;
+
+	if (!p_stat(buf.ptr, &st) && !S_ISREG(st.st_mode)) {
+		giterr_set(GITERR_REPOSITORY,
+			"cannot overwrite gitlink file into path '%s'", in_dir);
+		error = GIT_EEXISTS;
+		goto cleanup;
+	}
+
+	git_buf_clear(&buf);
+
+	error = git_buf_sets(&path_to_repo, to_repo);
+
+	if (!error && use_relative_path)
+		error = git_path_make_relative(&path_to_repo, in_dir);
+
+	if (!error)
+		error = git_buf_join(&buf, ' ', GIT_FILE_CONTENT_PREFIX, path_to_repo.ptr);
+
+	if (!error)
+		error = repo_write_template(in_dir, true, DOT_GIT, 0666, true, buf.ptr);
+
+cleanup:
+	git_buf_free(&buf);
+	git_buf_free(&path_to_repo);
+	return error;
+}
+
+static mode_t pick_dir_mode(git_repository_init_options *opts)
+{
+	if (opts->mode == GIT_REPOSITORY_INIT_SHARED_UMASK)
+		return 0777;
+	if (opts->mode == GIT_REPOSITORY_INIT_SHARED_GROUP)
+		return (0775 | S_ISGID);
+	if (opts->mode == GIT_REPOSITORY_INIT_SHARED_ALL)
+		return (0777 | S_ISGID);
+	return opts->mode;
+}
+
+#include "repo_template.h"
+
+static int repo_init_structure(
+	const char *repo_dir,
+	const char *work_dir,
+	git_repository_init_options *opts)
+{
+	int error = 0;
+	repo_template_item *tpl;
+	bool external_tpl =
+		((opts->flags & GIT_REPOSITORY_INIT_EXTERNAL_TEMPLATE) != 0);
+	mode_t dmode = pick_dir_mode(opts);
+	bool chmod = opts->mode != GIT_REPOSITORY_INIT_SHARED_UMASK;
+
+	/* Hide the ".git" directory */
+#ifdef GIT_WIN32
+	if ((opts->flags & GIT_REPOSITORY_INIT__HAS_DOTGIT) != 0) {
+		if (git_win32__set_hidden(repo_dir, true) < 0) {
+			giterr_set(GITERR_OS,
+				"failed to mark Git repository folder as hidden");
+			return -1;
+		}
+	}
+#endif
+
+	/* Create the .git gitlink if appropriate */
+	if ((opts->flags & GIT_REPOSITORY_INIT_BARE) == 0 &&
+		(opts->flags & GIT_REPOSITORY_INIT__NATURAL_WD) == 0)
+	{
+		if (repo_write_gitlink(work_dir, repo_dir, opts->flags & GIT_REPOSITORY_INIT_RELATIVE_GITLINK) < 0)
+			return -1;
+	}
+
+	/* Copy external template if requested */
+	if (external_tpl) {
+		git_config *cfg = NULL;
+		const char *tdir = NULL;
+		bool default_template = false;
+		git_buf template_buf = GIT_BUF_INIT;
+
+		if (opts->template_path)
+			tdir = opts->template_path;
+		else if ((error = git_config_open_default(&cfg)) >= 0) {
+			if (!git_config_get_path(&template_buf, cfg, "init.templatedir"))
+				tdir = template_buf.ptr;
+			giterr_clear();
+		}
+
+		if (!tdir) {
+			if (!(error = git_sysdir_find_template_dir(&template_buf)))
+				tdir = template_buf.ptr;
+			default_template = true;
+		}
+
+		/*
+		 * If tdir was the empty string, treat it like tdir was a path to an
+		 * empty directory (so, don't do any copying). This is the behavior
+		 * that git(1) exhibits, although it doesn't seem to be officially
+		 * documented.
+		 */
+		if (tdir && git__strcmp(tdir, "") != 0) {
+			uint32_t cpflags = GIT_CPDIR_COPY_SYMLINKS |
+				GIT_CPDIR_SIMPLE_TO_MODE |
+				GIT_CPDIR_COPY_DOTFILES;
+			if (opts->mode != GIT_REPOSITORY_INIT_SHARED_UMASK)
+					cpflags |= GIT_CPDIR_CHMOD_DIRS;
+			error = git_futils_cp_r(tdir, repo_dir, cpflags, dmode);
+		}
+
+		git_buf_free(&template_buf);
+		git_config_free(cfg);
+
+		if (error < 0) {
+			if (!default_template)
+				return error;
+
+			/* if template was default, ignore error and use internal */
+			giterr_clear();
+			external_tpl = false;
+			error = 0;
+		}
+	}
+
+	/* Copy internal template
+	 * - always ensure existence of dirs
+	 * - only create files if no external template was specified
+	 */
+	for (tpl = repo_template; !error && tpl->path; ++tpl) {
+		if (!tpl->content) {
+			uint32_t mkdir_flags = GIT_MKDIR_PATH;
+			if (chmod)
+				mkdir_flags |= GIT_MKDIR_CHMOD;
+
+			error = git_futils_mkdir_relative(
+				tpl->path, repo_dir, dmode, mkdir_flags, NULL);
+		}
+		else if (!external_tpl) {
+			const char *content = tpl->content;
+
+			if (opts->description && strcmp(tpl->path, GIT_DESC_FILE) == 0)
+				content = opts->description;
+
+			error = repo_write_template(
+				repo_dir, false, tpl->path, tpl->mode, false, content);
+		}
+	}
+
+	return error;
+}
+
+static int mkdir_parent(git_buf *buf, uint32_t mode, bool skip2)
+{
+	/* When making parent directories during repository initialization
+	 * don't try to set gid or grant world write access
+	 */
+	return git_futils_mkdir(
+		buf->ptr, mode & ~(S_ISGID | 0002),
+		GIT_MKDIR_PATH | GIT_MKDIR_VERIFY_DIR |
+		(skip2 ? GIT_MKDIR_SKIP_LAST2 : GIT_MKDIR_SKIP_LAST));
+}
+
+static int repo_init_directories(
+	git_buf *repo_path,
+	git_buf *wd_path,
+	const char *given_repo,
+	git_repository_init_options *opts)
+{
+	int error = 0;
+	bool is_bare, add_dotgit, has_dotgit, natural_wd;
+	mode_t dirmode;
+
+	/* There are three possible rules for what we are allowed to create:
+	 * - MKPATH means anything we need
+	 * - MKDIR means just the .git directory and its parent and the workdir
+	 * - Neither means only the .git directory can be created
+	 *
+	 * There are 5 "segments" of path that we might need to deal with:
+	 * 1. The .git directory
+	 * 2. The parent of the .git directory
+	 * 3. Everything above the parent of the .git directory
+	 * 4. The working directory (often the same as #2)
+	 * 5. Everything above the working directory (often the same as #3)
+	 *
+	 * For all directories created, we start with the init_mode value for
+	 * permissions and then strip off bits in some cases:
+	 *
+	 * For MKPATH, we create #3 (and #5) paths without S_ISGID or S_IWOTH
+	 * For MKPATH and MKDIR, we create #2 (and #4) without S_ISGID
+	 * For all rules, we create #1 using the untouched init_mode
+	 */
+
+	/* set up repo path */
+
+	is_bare = ((opts->flags & GIT_REPOSITORY_INIT_BARE) != 0);
+
+	add_dotgit =
+		(opts->flags & GIT_REPOSITORY_INIT_NO_DOTGIT_DIR) == 0 &&
+		!is_bare &&
+		git__suffixcmp(given_repo, "/" DOT_GIT) != 0 &&
+		git__suffixcmp(given_repo, "/" GIT_DIR) != 0;
+
+	if (git_buf_joinpath(repo_path, given_repo, add_dotgit ? GIT_DIR : "") < 0)
+		return -1;
+
+	has_dotgit = (git__suffixcmp(repo_path->ptr, "/" GIT_DIR) == 0);
+	if (has_dotgit)
+		opts->flags |= GIT_REPOSITORY_INIT__HAS_DOTGIT;
+
+	/* set up workdir path */
+
+	if (!is_bare) {
+		if (opts->workdir_path) {
+			if (git_path_join_unrooted(
+					wd_path, opts->workdir_path, repo_path->ptr, NULL) < 0)
+				return -1;
+		} else if (has_dotgit) {
+			if (git_path_dirname_r(wd_path, repo_path->ptr) < 0)
+				return -1;
+		} else {
+			giterr_set(GITERR_REPOSITORY, "cannot pick working directory"
+				" for non-bare repository that isn't a '.git' directory");
+			return -1;
+		}
+
+		if (git_path_to_dir(wd_path) < 0)
+			return -1;
+	} else {
+		git_buf_clear(wd_path);
+	}
+
+	natural_wd =
+		has_dotgit &&
+		wd_path->size > 0 &&
+		wd_path->size + strlen(GIT_DIR) == repo_path->size &&
+		memcmp(repo_path->ptr, wd_path->ptr, wd_path->size) == 0;
+	if (natural_wd)
+		opts->flags |= GIT_REPOSITORY_INIT__NATURAL_WD;
+
+	/* create directories as needed / requested */
+
+	dirmode = pick_dir_mode(opts);
+
+	if ((opts->flags & GIT_REPOSITORY_INIT_MKPATH) != 0) {
+		/* create path #5 */
+		if (wd_path->size > 0 &&
+			(error = mkdir_parent(wd_path, dirmode, false)) < 0)
+			return error;
+
+		/* create path #3 (if not the same as #5) */
+		if (!natural_wd &&
+			(error = mkdir_parent(repo_path, dirmode, has_dotgit)) < 0)
+			return error;
+	}
+
+	if ((opts->flags & GIT_REPOSITORY_INIT_MKDIR) != 0 ||
+		(opts->flags & GIT_REPOSITORY_INIT_MKPATH) != 0)
+	{
+		/* create path #4 */
+		if (wd_path->size > 0 &&
+			(error = git_futils_mkdir(
+				wd_path->ptr, dirmode & ~S_ISGID,
+				GIT_MKDIR_VERIFY_DIR)) < 0)
+			return error;
+
+		/* create path #2 (if not the same as #4) */
+		if (!natural_wd &&
+			(error = git_futils_mkdir(
+				repo_path->ptr, dirmode & ~S_ISGID,
+				GIT_MKDIR_VERIFY_DIR | GIT_MKDIR_SKIP_LAST)) < 0)
+			return error;
+	}
+
+	if ((opts->flags & GIT_REPOSITORY_INIT_MKDIR) != 0 ||
+		(opts->flags & GIT_REPOSITORY_INIT_MKPATH) != 0 ||
+		has_dotgit)
+	{
+		/* create path #1 */
+		error = git_futils_mkdir(repo_path->ptr, dirmode,
+			GIT_MKDIR_VERIFY_DIR | ((dirmode & S_ISGID) ? GIT_MKDIR_CHMOD : 0));
+	}
+
+	/* prettify both directories now that they are created */
+
+	if (!error) {
+		error = git_path_prettify_dir(repo_path, repo_path->ptr, NULL);
+
+		if (!error && wd_path->size > 0)
+			error = git_path_prettify_dir(wd_path, wd_path->ptr, NULL);
+	}
+
+	return error;
+}
+
+static int repo_init_create_origin(git_repository *repo, const char *url)
+{
+	int error;
+	git_remote *remote;
+
+	if (!(error = git_remote_create(&remote, repo, GIT_REMOTE_ORIGIN, url))) {
+		git_remote_free(remote);
+	}
+
+	return error;
+}
+
+int git_repository_init(
+	git_repository **repo_out, const char *path, unsigned is_bare)
+{
+	git_repository_init_options opts = GIT_REPOSITORY_INIT_OPTIONS_INIT;
+
+	opts.flags = GIT_REPOSITORY_INIT_MKPATH; /* don't love this default */
+	if (is_bare)
+		opts.flags |= GIT_REPOSITORY_INIT_BARE;
+
+	return git_repository_init_ext(repo_out, path, &opts);
+}
+
+int git_repository_init_ext(
+	git_repository **out,
+	const char *given_repo,
+	git_repository_init_options *opts)
+{
+	int error;
+	git_buf repo_path = GIT_BUF_INIT, wd_path = GIT_BUF_INIT,
+		common_path = GIT_BUF_INIT;
+	const char *wd;
+
+	assert(out && given_repo && opts);
+
+	GITERR_CHECK_VERSION(opts, GIT_REPOSITORY_INIT_OPTIONS_VERSION, "git_repository_init_options");
+
+	error = repo_init_directories(&repo_path, &wd_path, given_repo, opts);
+	if (error < 0)
+		goto cleanup;
+
+	wd = (opts->flags & GIT_REPOSITORY_INIT_BARE) ? NULL : git_buf_cstr(&wd_path);
+	if (valid_repository_path(&repo_path, &common_path)) {
+
+		if ((opts->flags & GIT_REPOSITORY_INIT_NO_REINIT) != 0) {
+			giterr_set(GITERR_REPOSITORY,
+				"attempt to reinitialize '%s'", given_repo);
+			error = GIT_EEXISTS;
+			goto cleanup;
+		}
+
+		opts->flags |= GIT_REPOSITORY_INIT__IS_REINIT;
+
+		error = repo_init_config(
+			repo_path.ptr, wd, opts->flags, opts->mode);
+
+		/* TODO: reinitialize the templates */
+	}
+	else {
+		if (!(error = repo_init_structure(
+				repo_path.ptr, wd, opts)) &&
+			!(error = repo_init_config(
+				repo_path.ptr, wd, opts->flags, opts->mode)))
+			error = git_repository_create_head(
+				repo_path.ptr, opts->initial_head);
+	}
+	if (error < 0)
+		goto cleanup;
+
+	error = git_repository_open(out, repo_path.ptr);
+
+	if (!error && opts->origin_url)
+		error = repo_init_create_origin(*out, opts->origin_url);
+
+cleanup:
+	git_buf_free(&common_path);
+	git_buf_free(&repo_path);
+	git_buf_free(&wd_path);
+
+	return error;
+}
+
+int git_repository_head_detached(git_repository *repo)
+{
+	git_reference *ref;
+	git_odb *odb = NULL;
+	int exists;
+
+	if (git_repository_odb__weakptr(&odb, repo) < 0)
+		return -1;
+
+	if (git_reference_lookup(&ref, repo, GIT_HEAD_FILE) < 0)
+		return -1;
+
+	if (git_reference_type(ref) == GIT_REF_SYMBOLIC) {
+		git_reference_free(ref);
+		return 0;
+	}
+
+	exists = git_odb_exists(odb, git_reference_target(ref));
+
+	git_reference_free(ref);
+	return exists;
+}
+
+static int get_worktree_file_path(git_buf *out, git_repository *repo, const char *worktree, const char *file)
+{
+	git_buf_clear(out);
+	return git_buf_printf(out, "%s/worktrees/%s/%s", repo->commondir, worktree, file);
+}
+
+int git_repository_head_detached_for_worktree(git_repository *repo, const char *name)
+{
+	git_reference *ref = NULL;
+	int error;
+
+	assert(repo && name);
+
+	if ((error = git_repository_head_for_worktree(&ref, repo, name)) < 0)
+		goto out;
+
+	error = (git_reference_type(ref) != GIT_REF_SYMBOLIC);
+out:
+	git_reference_free(ref);
+
+	return error;
+}
+
+int git_repository_head(git_reference **head_out, git_repository *repo)
+{
+	git_reference *head;
+	int error;
+
+	if ((error = git_reference_lookup(&head, repo, GIT_HEAD_FILE)) < 0)
+		return error;
+
+	if (git_reference_type(head) == GIT_REF_OID) {
+		*head_out = head;
+		return 0;
+	}
+
+	error = git_reference_lookup_resolved(head_out, repo, git_reference_symbolic_target(head), -1);
+	git_reference_free(head);
+
+	return error == GIT_ENOTFOUND ? GIT_EUNBORNBRANCH : error;
+}
+
+int git_repository_head_for_worktree(git_reference **out, git_repository *repo, const char *name)
+{
+	git_buf path = GIT_BUF_INIT;
+	git_reference *head = NULL;
+	int error;
+
+	assert(out && repo && name);
+
+	*out = NULL;
+
+	if ((error = get_worktree_file_path(&path, repo, name, GIT_HEAD_FILE)) < 0 ||
+	    (error = git_reference__read_head(&head, repo, path.ptr)) < 0)
+		goto out;
+
+	if (git_reference_type(head) != GIT_REF_OID) {
+		git_reference *resolved;
+
+		error = git_reference_lookup_resolved(&resolved, repo, git_reference_symbolic_target(head), -1);
+		git_reference_free(head);
+		head = resolved;
+	}
+
+	*out = head;
+
+out:
+	if (error)
+		git_reference_free(head);
+
+	git_buf_free(&path);
+
+	return error;
+}
+
+int git_repository_foreach_head(git_repository *repo, git_repository_foreach_head_cb cb, void *payload)
+{
+	git_strarray worktrees = GIT_VECTOR_INIT;
+	git_buf path = GIT_BUF_INIT;
+	int error;
+	size_t i;
+
+	/* Execute callback for HEAD of commondir */
+	if ((error = git_buf_joinpath(&path, repo->commondir, GIT_HEAD_FILE)) < 0 ||
+	    (error = cb(repo, path.ptr, payload) != 0))
+		goto out;
+
+	if ((error = git_worktree_list(&worktrees, repo)) < 0) {
+		error = 0;
+		goto out;
+	}
+
+	/* Execute callback for all worktree HEADs */
+	for (i = 0; i < worktrees.count; i++) {
+		if (get_worktree_file_path(&path, repo, worktrees.strings[i], GIT_HEAD_FILE) < 0)
+			continue;
+
+		if ((error = cb(repo, path.ptr, payload)) != 0)
+			goto out;
+	}
+
+out:
+	git_buf_free(&path);
+	git_strarray_free(&worktrees);
+	return error;
+}
+
+int git_repository_head_unborn(git_repository *repo)
+{
+	git_reference *ref = NULL;
+	int error;
+
+	error = git_repository_head(&ref, repo);
+	git_reference_free(ref);
+
+	if (error == GIT_EUNBORNBRANCH) {
+		giterr_clear();
+		return 1;
+	}
+
+	if (error < 0)
+		return -1;
+
+	return 0;
+}
+
+static int at_least_one_cb(const char *refname, void *payload)
+{
+	GIT_UNUSED(refname);
+	GIT_UNUSED(payload);
+	return GIT_PASSTHROUGH;
+}
+
+static int repo_contains_no_reference(git_repository *repo)
+{
+	int error = git_reference_foreach_name(repo, &at_least_one_cb, NULL);
+
+	if (error == GIT_PASSTHROUGH)
+		return 0;
+
+	if (!error)
+		return 1;
+
+	return error;
+}
+
+int git_repository_is_empty(git_repository *repo)
+{
+	git_reference *head = NULL;
+	int is_empty = 0;
+
+	if (git_reference_lookup(&head, repo, GIT_HEAD_FILE) < 0)
+		return -1;
+
+	if (git_reference_type(head) == GIT_REF_SYMBOLIC)
+		is_empty =
+			(strcmp(git_reference_symbolic_target(head),
+					GIT_REFS_HEADS_DIR "master") == 0) &&
+			repo_contains_no_reference(repo);
+
+	git_reference_free(head);
+
+	return is_empty;
+}
+
+int git_repository_item_path(git_buf *out, const git_repository *repo, git_repository_item_t item)
+{
+	const char *parent;
+
+	switch (items[item].parent) {
+		case GIT_REPOSITORY_ITEM_GITDIR:
+			parent = git_repository_path(repo);
+			break;
+		case GIT_REPOSITORY_ITEM_WORKDIR:
+			parent = git_repository_workdir(repo);
+			break;
+		case GIT_REPOSITORY_ITEM_COMMONDIR:
+			parent = git_repository_commondir(repo);
+			break;
+		default:
+			giterr_set(GITERR_INVALID, "invalid item directory");
+			return -1;
+	}
+
+	if (parent == NULL) {
+		giterr_set(GITERR_INVALID, "path cannot exist in repository");
+		return GIT_ENOTFOUND;
+	}
+
+	if (git_buf_sets(out, parent) < 0)
+		return -1;
+
+	if (items[item].name) {
+		if (git_buf_joinpath(out, parent, items[item].name) < 0)
+			return -1;
+	}
+
+	if (items[item].directory) {
+		if (git_path_to_dir(out) < 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+const char *git_repository_path(const git_repository *repo)
+{
+	assert(repo);
+	return repo->gitdir;
+}
+
+const char *git_repository_workdir(const git_repository *repo)
+{
+	assert(repo);
+
+	if (repo->is_bare)
+		return NULL;
+
+	return repo->workdir;
+}
+
+const char *git_repository_commondir(const git_repository *repo)
+{
+	assert(repo);
+	return repo->commondir;
+}
+
+int git_repository_set_workdir(
+	git_repository *repo, const char *workdir, int update_gitlink)
+{
+	int error = 0;
+	git_buf path = GIT_BUF_INIT;
+
+	assert(repo && workdir);
+
+	if (git_path_prettify_dir(&path, workdir, NULL) < 0)
+		return -1;
+
+	if (repo->workdir && strcmp(repo->workdir, path.ptr) == 0)
+		return 0;
+
+	if (update_gitlink) {
+		git_config *config;
+
+		if (git_repository_config__weakptr(&config, repo) < 0)
+			return -1;
+
+		error = repo_write_gitlink(path.ptr, git_repository_path(repo), false);
+
+		/* passthrough error means gitlink is unnecessary */
+		if (error == GIT_PASSTHROUGH)
+			error = git_config_delete_entry(config, "core.worktree");
+		else if (!error)
+			error = git_config_set_string(config, "core.worktree", path.ptr);
+
+		if (!error)
+			error = git_config_set_bool(config, "core.bare", false);
+	}
+
+	if (!error) {
+		char *old_workdir = repo->workdir;
+
+		repo->workdir = git_buf_detach(&path);
+		repo->is_bare = 0;
+
+		git__free(old_workdir);
+	}
+
+	return error;
+}
+
+int git_repository_is_bare(const git_repository *repo)
+{
+	assert(repo);
+	return repo->is_bare;
+}
+
+int git_repository_is_worktree(const git_repository *repo)
+{
+	assert(repo);
+	return repo->is_worktree;
+}
+
+int git_repository_set_bare(git_repository *repo)
+{
+	int error;
+	git_config *config;
+
+	assert(repo);
+
+	if (repo->is_bare)
+		return 0;
+
+	if ((error = git_repository_config__weakptr(&config, repo)) < 0)
+		return error;
+
+	if ((error = git_config_set_bool(config, "core.bare", true)) < 0)
+		return error;
+
+	if ((error = git_config__update_entry(config, "core.worktree", NULL, true, true)) < 0)
+		return error;
+
+	git__free(repo->workdir);
+	repo->workdir = NULL;
+	repo->is_bare = 1;
+
+	return 0;
+}
+
+int git_repository_head_tree(git_tree **tree, git_repository *repo)
+{
+	git_reference *head;
+	git_object *obj;
+	int error;
+
+	if ((error = git_repository_head(&head, repo)) < 0)
+		return error;
+
+	if ((error = git_reference_peel(&obj, head, GIT_OBJ_TREE)) < 0)
+		goto cleanup;
+
+	*tree = (git_tree *)obj;
+
+cleanup:
+	git_reference_free(head);
+	return error;
+}
+
+int git_repository__set_orig_head(git_repository *repo, const git_oid *orig_head)
+{
+	git_filebuf file = GIT_FILEBUF_INIT;
+	git_buf file_path = GIT_BUF_INIT;
+	char orig_head_str[GIT_OID_HEXSZ];
+	int error = 0;
+
+	git_oid_fmt(orig_head_str, orig_head);
+
+	if ((error = git_buf_joinpath(&file_path, repo->gitdir, GIT_ORIG_HEAD_FILE)) == 0 &&
+		(error = git_filebuf_open(&file, file_path.ptr, GIT_FILEBUF_FORCE, GIT_MERGE_FILE_MODE)) == 0 &&
+		(error = git_filebuf_printf(&file, "%.*s\n", GIT_OID_HEXSZ, orig_head_str)) == 0)
+		error = git_filebuf_commit(&file);
+
+	if (error < 0)
+		git_filebuf_cleanup(&file);
+
+	git_buf_free(&file_path);
+
+	return error;
+}
+
+int git_repository_message(git_buf *out, git_repository *repo)
+{
+	git_buf path = GIT_BUF_INIT;
+	struct stat st;
+	int error;
+
+	git_buf_sanitize(out);
+
+	if (git_buf_joinpath(&path, repo->gitdir, GIT_MERGE_MSG_FILE) < 0)
+		return -1;
+
+	if ((error = p_stat(git_buf_cstr(&path), &st)) < 0) {
+		if (errno == ENOENT)
+			error = GIT_ENOTFOUND;
+		giterr_set(GITERR_OS, "could not access message file");
+	} else {
+		error = git_futils_readbuffer(out, git_buf_cstr(&path));
+	}
+
+	git_buf_free(&path);
+
+	return error;
+}
+
+int git_repository_message_remove(git_repository *repo)
+{
+	git_buf path = GIT_BUF_INIT;
+	int error;
+
+	if (git_buf_joinpath(&path, repo->gitdir, GIT_MERGE_MSG_FILE) < 0)
+		return -1;
+
+	error = p_unlink(git_buf_cstr(&path));
+	git_buf_free(&path);
+
+	return error;
+}
+
+int git_repository_hashfile(
+	git_oid *out,
+	git_repository *repo,
+	const char *path,
+	git_otype type,
+	const char *as_path)
+{
+	int error;
+	git_filter_list *fl = NULL;
+	git_file fd = -1;
+	git_off_t len;
+	git_buf full_path = GIT_BUF_INIT;
+
+	assert(out && path && repo); /* as_path can be NULL */
+
+	/* At some point, it would be nice if repo could be NULL to just
+	 * apply filter rules defined in system and global files, but for
+	 * now that is not possible because git_filters_load() needs it.
+	 */
+
+	error = git_path_join_unrooted(
+		&full_path, path, git_repository_workdir(repo), NULL);
+	if (error < 0)
+		return error;
+
+	if (!as_path)
+		as_path = path;
+
+	/* passing empty string for "as_path" indicated --no-filters */
+	if (strlen(as_path) > 0) {
+		error = git_filter_list_load(
+			&fl, repo, NULL, as_path,
+			GIT_FILTER_TO_ODB, GIT_FILTER_DEFAULT);
+		if (error < 0)
+			return error;
+	} else {
+		error = 0;
+	}
+
+	/* at this point, error is a count of the number of loaded filters */
+
+	fd = git_futils_open_ro(full_path.ptr);
+	if (fd < 0) {
+		error = fd;
+		goto cleanup;
+	}
+
+	len = git_futils_filesize(fd);
+	if (len < 0) {
+		error = (int)len;
+		goto cleanup;
+	}
+
+	if (!git__is_sizet(len)) {
+		giterr_set(GITERR_OS, "file size overflow for 32-bit systems");
+		error = -1;
+		goto cleanup;
+	}
+
+	error = git_odb__hashfd_filtered(out, fd, (size_t)len, type, fl);
+
+cleanup:
+	if (fd >= 0)
+		p_close(fd);
+	git_filter_list_free(fl);
+	git_buf_free(&full_path);
+
+	return error;
+}
+
+static int checkout_message(git_buf *out, git_reference *old, const char *new)
+{
+	git_buf_puts(out, "checkout: moving from ");
+
+	if (git_reference_type(old) == GIT_REF_SYMBOLIC)
+		git_buf_puts(out, git_reference__shorthand(git_reference_symbolic_target(old)));
+	else
+		git_buf_puts(out, git_oid_tostr_s(git_reference_target(old)));
+
+	git_buf_puts(out, " to ");
+
+	if (git_reference__is_branch(new) ||
+		git_reference__is_tag(new) ||
+		git_reference__is_remote(new))
+		git_buf_puts(out, git_reference__shorthand(new));
+	else
+		git_buf_puts(out, new);
+
+	if (git_buf_oom(out))
+		return -1;
+
+	return 0;
+}
+
+static int detach(git_repository *repo, const git_oid *id, const char *new)
+{
+	int error;
+	git_buf log_message = GIT_BUF_INIT;
+	git_object *object = NULL, *peeled = NULL;
+	git_reference *new_head = NULL, *current = NULL;
+
+	assert(repo && id);
+
+	if ((error = git_reference_lookup(&current, repo, GIT_HEAD_FILE)) < 0)
+		return error;
+
+	if ((error = git_object_lookup(&object, repo, id, GIT_OBJ_ANY)) < 0)
+		goto cleanup;
+
+	if ((error = git_object_peel(&peeled, object, GIT_OBJ_COMMIT)) < 0)
+		goto cleanup;
+
+	if (new == NULL)
+		new = git_oid_tostr_s(git_object_id(peeled));
+
+	if ((error = checkout_message(&log_message, current, new)) < 0)
+		goto cleanup;
+
+	error = git_reference_create(&new_head, repo, GIT_HEAD_FILE, git_object_id(peeled), true, git_buf_cstr(&log_message));
+
+cleanup:
+	git_buf_free(&log_message);
+	git_object_free(object);
+	git_object_free(peeled);
+	git_reference_free(current);
+	git_reference_free(new_head);
+	return error;
+}
+
+int git_repository_set_head(
+	git_repository* repo,
+	const char* refname)
+{
+	git_reference *ref = NULL, *current = NULL, *new_head = NULL;
+	git_buf log_message = GIT_BUF_INIT;
+	int error;
+
+	assert(repo && refname);
+
+	if ((error = git_reference_lookup(&current, repo, GIT_HEAD_FILE)) < 0)
+		return error;
+
+	if ((error = checkout_message(&log_message, current, refname)) < 0)
+		goto cleanup;
+
+	error = git_reference_lookup(&ref, repo, refname);
+	if (error < 0 && error != GIT_ENOTFOUND)
+		goto cleanup;
+
+	if (ref && current->type == GIT_REF_SYMBOLIC && git__strcmp(current->target.symbolic, ref->name) &&
+	    git_reference_is_branch(ref) && git_branch_is_checked_out(ref)) {
+		giterr_set(GITERR_REPOSITORY, "cannot set HEAD to reference '%s' as it is the current HEAD "
+			"of a linked repository.", git_reference_name(ref));
+		error = -1;
+		goto cleanup;
+	}
+
+	if (!error) {
+		if (git_reference_is_branch(ref)) {
+			error = git_reference_symbolic_create(&new_head, repo, GIT_HEAD_FILE,
+					git_reference_name(ref), true, git_buf_cstr(&log_message));
+		} else {
+			error = detach(repo, git_reference_target(ref),
+				git_reference_is_tag(ref) || git_reference_is_remote(ref) ? refname : NULL);
+		}
+	} else if (git_reference__is_branch(refname)) {
+		error = git_reference_symbolic_create(&new_head, repo, GIT_HEAD_FILE, refname,
+				true, git_buf_cstr(&log_message));
+	}
+
+cleanup:
+	git_buf_free(&log_message);
+	git_reference_free(current);
+	git_reference_free(ref);
+	git_reference_free(new_head);
+	return error;
+}
+
+int git_repository_set_head_detached(
+	git_repository* repo,
+	const git_oid* commitish)
+{
+	return detach(repo, commitish, NULL);
+}
+
+int git_repository_set_head_detached_from_annotated(
+	git_repository *repo,
+	const git_annotated_commit *commitish)
+{
+	assert(repo && commitish);
+
+	return detach(repo, git_annotated_commit_id(commitish), commitish->description);
+}
+
+int git_repository_detach_head(git_repository* repo)
+{
+	git_reference *old_head = NULL,	*new_head = NULL, *current = NULL;
+	git_object *object = NULL;
+	git_buf log_message = GIT_BUF_INIT;
+	int error;
+
+	assert(repo);
+
+	if ((error = git_reference_lookup(&current, repo, GIT_HEAD_FILE)) < 0)
+		return error;
+
+	if ((error = git_repository_head(&old_head, repo)) < 0)
+		goto cleanup;
+
+	if ((error = git_object_lookup(&object, repo, git_reference_target(old_head), GIT_OBJ_COMMIT)) < 0)
+		goto cleanup;
+
+	if ((error = checkout_message(&log_message, current, git_oid_tostr_s(git_object_id(object)))) < 0)
+		goto cleanup;
+
+	error = git_reference_create(&new_head, repo, GIT_HEAD_FILE, git_reference_target(old_head),
+			1, git_buf_cstr(&log_message));
+
+cleanup:
+	git_buf_free(&log_message);
+	git_object_free(object);
+	git_reference_free(old_head);
+	git_reference_free(new_head);
+	git_reference_free(current);
+	return error;
+}
+
+/**
+ * Loosely ported from git.git
+ * https://github.com/git/git/blob/master/contrib/completion/git-prompt.sh#L198-289
+ */
+int git_repository_state(git_repository *repo)
+{
+	git_buf repo_path = GIT_BUF_INIT;
+	int state = GIT_REPOSITORY_STATE_NONE;
+
+	assert(repo);
+
+	if (git_buf_puts(&repo_path, repo->gitdir) < 0)
+		return -1;
+
+	if (git_path_contains_file(&repo_path, GIT_REBASE_MERGE_INTERACTIVE_FILE))
+		state = GIT_REPOSITORY_STATE_REBASE_INTERACTIVE;
+	else if (git_path_contains_dir(&repo_path, GIT_REBASE_MERGE_DIR))
+		state = GIT_REPOSITORY_STATE_REBASE_MERGE;
+	else if (git_path_contains_file(&repo_path, GIT_REBASE_APPLY_REBASING_FILE))
+		state = GIT_REPOSITORY_STATE_REBASE;
+	else if (git_path_contains_file(&repo_path, GIT_REBASE_APPLY_APPLYING_FILE))
+		state = GIT_REPOSITORY_STATE_APPLY_MAILBOX;
+	else if (git_path_contains_dir(&repo_path, GIT_REBASE_APPLY_DIR))
+		state = GIT_REPOSITORY_STATE_APPLY_MAILBOX_OR_REBASE;
+	else if (git_path_contains_file(&repo_path, GIT_MERGE_HEAD_FILE))
+		state = GIT_REPOSITORY_STATE_MERGE;
+	else if (git_path_contains_file(&repo_path, GIT_REVERT_HEAD_FILE)) {
+		state = GIT_REPOSITORY_STATE_REVERT;
+		if (git_path_contains_file(&repo_path, GIT_SEQUENCER_TODO_FILE)) {
+			state = GIT_REPOSITORY_STATE_REVERT_SEQUENCE;
+		}
+	} else if (git_path_contains_file(&repo_path, GIT_CHERRYPICK_HEAD_FILE)) {
+		state = GIT_REPOSITORY_STATE_CHERRYPICK;
+		if (git_path_contains_file(&repo_path, GIT_SEQUENCER_TODO_FILE)) {
+			state = GIT_REPOSITORY_STATE_CHERRYPICK_SEQUENCE;
+		}
+	} else if (git_path_contains_file(&repo_path, GIT_BISECT_LOG_FILE))
+		state = GIT_REPOSITORY_STATE_BISECT;
+
+	git_buf_free(&repo_path);
+	return state;
+}
+
+int git_repository__cleanup_files(
+	git_repository *repo, const char *files[], size_t files_len)
+{
+	git_buf buf = GIT_BUF_INIT;
+	size_t i;
+	int error;
+
+	for (error = 0, i = 0; !error && i < files_len; ++i) {
+		const char *path;
+
+		if (git_buf_joinpath(&buf, repo->gitdir, files[i]) < 0)
+			return -1;
+
+		path = git_buf_cstr(&buf);
+
+		if (git_path_isfile(path)) {
+			error = p_unlink(path);
+		} else if (git_path_isdir(path)) {
+			error = git_futils_rmdir_r(path, NULL,
+				GIT_RMDIR_REMOVE_FILES | GIT_RMDIR_REMOVE_BLOCKERS);
+		}
+
+		git_buf_clear(&buf);
+	}
+
+	git_buf_free(&buf);
+	return error;
+}
+
+static const char *state_files[] = {
+	GIT_MERGE_HEAD_FILE,
+	GIT_MERGE_MODE_FILE,
+	GIT_MERGE_MSG_FILE,
+	GIT_REVERT_HEAD_FILE,
+	GIT_CHERRYPICK_HEAD_FILE,
+	GIT_BISECT_LOG_FILE,
+	GIT_REBASE_MERGE_DIR,
+	GIT_REBASE_APPLY_DIR,
+	GIT_SEQUENCER_DIR,
+};
+
+int git_repository_state_cleanup(git_repository *repo)
+{
+	assert(repo);
+
+	return git_repository__cleanup_files(repo, state_files, ARRAY_SIZE(state_files));
+}
+
+int git_repository_is_shallow(git_repository *repo)
+{
+	git_buf path = GIT_BUF_INIT;
+	struct stat st;
+	int error;
+
+	if ((error = git_buf_joinpath(&path, repo->gitdir, "shallow")) < 0)
+		return error;
+
+	error = git_path_lstat(path.ptr, &st);
+	git_buf_free(&path);
+
+	if (error == GIT_ENOTFOUND) {
+		giterr_clear();
+		return 0;
+	}
+
+	if (error < 0)
+		return error;
+	return st.st_size == 0 ? 0 : 1;
+}
+
+int git_repository_init_init_options(
+	git_repository_init_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_repository_init_options,
+		GIT_REPOSITORY_INIT_OPTIONS_INIT);
+	return 0;
+}
+
+int git_repository_ident(const char **name, const char **email, const git_repository *repo)
+{
+	*name = repo->ident_name;
+	*email = repo->ident_email;
+
+	return 0;
+}
+
+int git_repository_set_ident(git_repository *repo, const char *name, const char *email)
+{
+	char *tmp_name = NULL, *tmp_email = NULL;
+
+	if (name) {
+		tmp_name = git__strdup(name);
+		GITERR_CHECK_ALLOC(tmp_name);
+	}
+
+	if (email) {
+		tmp_email = git__strdup(email);
+		GITERR_CHECK_ALLOC(tmp_email);
+	}
+
+	tmp_name = git__swap(repo->ident_name, tmp_name);
+	tmp_email = git__swap(repo->ident_email, tmp_email);
+
+	git__free(tmp_name);
+	git__free(tmp_email);
+
+	return 0;
+}
+
+int git_repository_submodule_cache_all(git_repository *repo)
+{
+	int error;
+
+	assert(repo);
+
+	if ((error = git_strmap_alloc(&repo->submodule_cache)))
+		return error;
+
+	error = git_submodule__map(repo, repo->submodule_cache);
+	return error;
+}
+
+int git_repository_submodule_cache_clear(git_repository *repo)
+{
+	git_submodule *sm;
+	assert(repo);
+	if (repo->submodule_cache == NULL) {
+		return 0;
+	}
+	git_strmap_foreach_value(repo->submodule_cache, sm, {
+		git_submodule_free(sm);
+	});
+	git_strmap_free(repo->submodule_cache);
+	repo->submodule_cache = 0;
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/repository.h

diff --git a/vendor/libgit2-sys/libgit2/src/repository.h b/vendor/libgit2-sys/libgit2/src/repository.h
new file mode 100644
index 0000000..fd6400c
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/repository.h
@@ -0,0 +1,246 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_repository_h__
+#define INCLUDE_repository_h__
+
+#include "common.h"
+
+#include "git2/common.h"
+#include "git2/oid.h"
+#include "git2/odb.h"
+#include "git2/repository.h"
+#include "git2/object.h"
+#include "git2/config.h"
+
+#include "array.h"
+#include "cache.h"
+#include "refs.h"
+#include "buffer.h"
+#include "object.h"
+#include "attrcache.h"
+#include "submodule.h"
+#include "diff_driver.h"
+
+#define DOT_GIT ".git"
+#define GIT_DIR DOT_GIT "/"
+#define GIT_DIR_MODE 0755
+#define GIT_BARE_DIR_MODE 0777
+
+/* Default DOS-compatible 8.3 "short name" for a git repository, "GIT~1" */
+#define GIT_DIR_SHORTNAME "GIT~1"
+
+extern bool git_repository__fsync_gitdir;
+
+/** Cvar cache identifiers */
+typedef enum {
+	GIT_CVAR_AUTO_CRLF = 0, /* core.autocrlf */
+	GIT_CVAR_EOL,           /* core.eol */
+	GIT_CVAR_SYMLINKS,      /* core.symlinks */
+	GIT_CVAR_IGNORECASE,    /* core.ignorecase */
+	GIT_CVAR_FILEMODE,      /* core.filemode */
+	GIT_CVAR_IGNORESTAT,    /* core.ignorestat */
+	GIT_CVAR_TRUSTCTIME,    /* core.trustctime */
+	GIT_CVAR_ABBREV,        /* core.abbrev */
+	GIT_CVAR_PRECOMPOSE,    /* core.precomposeunicode */
+	GIT_CVAR_SAFE_CRLF,		/* core.safecrlf */
+	GIT_CVAR_LOGALLREFUPDATES, /* core.logallrefupdates */
+	GIT_CVAR_PROTECTHFS,    /* core.protectHFS */
+	GIT_CVAR_PROTECTNTFS,   /* core.protectNTFS */
+	GIT_CVAR_FSYNCOBJECTFILES, /* core.fsyncObjectFiles */
+	GIT_CVAR_CACHE_MAX
+} git_cvar_cached;
+
+/**
+ * CVAR value enumerations
+ *
+ * These are the values that are actually stored in the cvar cache, instead
+ * of their string equivalents. These values are internal and symbolic;
+ * make sure that none of them is set to `-1`, since that is the unique
+ * identifier for "not cached"
+ */
+typedef enum {
+	/* The value hasn't been loaded from the cache yet */
+	GIT_CVAR_NOT_CACHED = -1,
+
+	/* core.safecrlf: false, 'fail', 'warn' */
+	GIT_SAFE_CRLF_FALSE = 0,
+	GIT_SAFE_CRLF_FAIL = 1,
+	GIT_SAFE_CRLF_WARN = 2,
+
+	/* core.autocrlf: false, true, 'input; */
+	GIT_AUTO_CRLF_FALSE = 0,
+	GIT_AUTO_CRLF_TRUE = 1,
+	GIT_AUTO_CRLF_INPUT = 2,
+	GIT_AUTO_CRLF_DEFAULT = GIT_AUTO_CRLF_FALSE,
+
+	/* core.eol: unset, 'crlf', 'lf', 'native' */
+	GIT_EOL_UNSET = 0,
+	GIT_EOL_CRLF = 1,
+	GIT_EOL_LF = 2,
+#ifdef GIT_WIN32
+	GIT_EOL_NATIVE = GIT_EOL_CRLF,
+#else
+	GIT_EOL_NATIVE = GIT_EOL_LF,
+#endif
+	GIT_EOL_DEFAULT = GIT_EOL_NATIVE,
+
+	/* core.symlinks: bool */
+	GIT_SYMLINKS_DEFAULT = GIT_CVAR_TRUE,
+	/* core.ignorecase */
+	GIT_IGNORECASE_DEFAULT = GIT_CVAR_FALSE,
+	/* core.filemode */
+	GIT_FILEMODE_DEFAULT = GIT_CVAR_TRUE,
+	/* core.ignorestat */
+	GIT_IGNORESTAT_DEFAULT = GIT_CVAR_FALSE,
+	/* core.trustctime */
+	GIT_TRUSTCTIME_DEFAULT = GIT_CVAR_TRUE,
+	/* core.abbrev */
+	GIT_ABBREV_DEFAULT = 7,
+	/* core.precomposeunicode */
+	GIT_PRECOMPOSE_DEFAULT = GIT_CVAR_FALSE,
+	/* core.safecrlf */
+	GIT_SAFE_CRLF_DEFAULT = GIT_CVAR_FALSE,
+	/* core.logallrefupdates */
+	GIT_LOGALLREFUPDATES_UNSET = 2,
+	GIT_LOGALLREFUPDATES_DEFAULT = GIT_LOGALLREFUPDATES_UNSET,
+	/* core.protectHFS */
+	GIT_PROTECTHFS_DEFAULT = GIT_CVAR_FALSE,
+	/* core.protectNTFS */
+	GIT_PROTECTNTFS_DEFAULT = GIT_CVAR_FALSE,
+	/* core.fsyncObjectFiles */
+	GIT_FSYNCOBJECTFILES_DEFAULT = GIT_CVAR_FALSE,
+} git_cvar_value;
+
+/* internal repository init flags */
+enum {
+	GIT_REPOSITORY_INIT__HAS_DOTGIT = (1u << 16),
+	GIT_REPOSITORY_INIT__NATURAL_WD = (1u << 17),
+	GIT_REPOSITORY_INIT__IS_REINIT  = (1u << 18),
+};
+
+/** Internal structure for repository object */
+struct git_repository {
+	git_odb *_odb;
+	git_refdb *_refdb;
+	git_config *_config;
+	git_index *_index;
+
+	git_cache objects;
+	git_attr_cache *attrcache;
+	git_diff_driver_registry *diff_drivers;
+
+	char *gitlink;
+	char *gitdir;
+	char *commondir;
+	char *workdir;
+	char *namespace;
+
+	char *ident_name;
+	char *ident_email;
+
+	git_array_t(git_buf) reserved_names;
+
+	unsigned is_bare:1;
+	unsigned is_worktree:1;
+
+	unsigned int lru_counter;
+
+	git_atomic attr_session_key;
+
+	git_cvar_value cvar_cache[GIT_CVAR_CACHE_MAX];
+	git_strmap *submodule_cache;
+};
+
+GIT_INLINE(git_attr_cache *) git_repository_attr_cache(git_repository *repo)
+{
+	return repo->attrcache;
+}
+
+int git_repository_head_tree(git_tree **tree, git_repository *repo);
+int git_repository_create_head(const char *git_dir, const char *ref_name);
+
+/*
+ * Called for each HEAD.
+ *
+ * Can return either 0, causing the iteration over HEADs to
+ * continue, or a non-0 value causing the iteration to abort. The
+ * return value is passed back to the caller of
+ * `git_repository_foreach_head`
+ */
+typedef int (*git_repository_foreach_head_cb)(git_repository *repo, const char *path, void *payload);
+
+/*
+ * Iterate over repository and all worktree HEADs.
+ *
+ * This function will be called for the repository HEAD and for
+ * all HEADS of linked worktrees. For each HEAD, the callback is
+ * executed with the given payload. The return value equals the
+ * return value of the last executed callback function.
+ */
+int git_repository_foreach_head(git_repository *repo, git_repository_foreach_head_cb cb, void *payload);
+
+/*
+ * Weak pointers to repository internals.
+ *
+ * The returned pointers do not need to be freed. Do not keep
+ * permanent references to these (i.e. between API calls), since they may
+ * become invalidated if the user replaces a repository internal.
+ */
+int git_repository_config__weakptr(git_config **out, git_repository *repo);
+int git_repository_odb__weakptr(git_odb **out, git_repository *repo);
+int git_repository_refdb__weakptr(git_refdb **out, git_repository *repo);
+int git_repository_index__weakptr(git_index **out, git_repository *repo);
+
+/*
+ * CVAR cache
+ *
+ * Efficient access to the most used config variables of a repository.
+ * The cache is cleared every time the config backend is replaced.
+ */
+int git_repository__cvar(int *out, git_repository *repo, git_cvar_cached cvar);
+void git_repository__cvar_cache_clear(git_repository *repo);
+
+GIT_INLINE(int) git_repository__ensure_not_bare(
+	git_repository *repo,
+	const char *operation_name)
+{
+	if (!git_repository_is_bare(repo))
+		return 0;
+
+	giterr_set(
+		GITERR_REPOSITORY,
+		"cannot %s. This operation is not allowed against bare repositories.",
+		operation_name);
+
+	return GIT_EBAREREPO;
+}
+
+int git_repository__set_orig_head(git_repository *repo, const git_oid *orig_head);
+
+int git_repository__cleanup_files(git_repository *repo, const char *files[], size_t files_len);
+
+/* The default "reserved names" for a repository */
+extern git_buf git_repository__reserved_names_win32[];
+extern size_t git_repository__reserved_names_win32_len;
+
+extern git_buf git_repository__reserved_names_posix[];
+extern size_t git_repository__reserved_names_posix_len;
+
+/*
+ * Gets any "reserved names" in the repository.  This will return paths
+ * that should not be allowed in the repository (like ".git") to avoid
+ * conflicting with the repository path, or with alternate mechanisms to
+ * the repository path (eg, "GIT~1").  Every attempt will be made to look
+ * up all possible reserved names - if there was a conflict for the shortname
+ * GIT~1, for example, this function will try to look up the alternate
+ * shortname.  If that fails, this function returns false, but out and outlen
+ * will still be populated with good defaults.
+ */
+bool git_repository__reserved_names(
+	git_buf **out, size_t *outlen, git_repository *repo, bool include_ntfs);
+
+#endif

vendor/libgit2-sys/libgit2/src/reset.c

diff --git a/vendor/libgit2-sys/libgit2/src/reset.c b/vendor/libgit2-sys/libgit2/src/reset.c
new file mode 100644
index 0000000..2159681
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/reset.c
@@ -0,0 +1,200 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "commit.h"
+#include "tag.h"
+#include "merge.h"
+#include "diff.h"
+#include "annotated_commit.h"
+#include "git2/reset.h"
+#include "git2/checkout.h"
+#include "git2/merge.h"
+#include "git2/refs.h"
+
+#define ERROR_MSG "Cannot perform reset"
+
+int git_reset_default(
+	git_repository *repo,
+	const git_object *target,
+	const git_strarray* pathspecs)
+{
+	git_object *commit = NULL;
+	git_tree *tree = NULL;
+	git_diff *diff = NULL;
+	git_diff_options opts = GIT_DIFF_OPTIONS_INIT;
+	size_t i, max_i;
+	git_index_entry entry;
+	int error;
+	git_index *index = NULL;
+
+	assert(pathspecs != NULL && pathspecs->count > 0);
+
+	memset(&entry, 0, sizeof(git_index_entry));
+
+	if ((error = git_repository_index(&index, repo)) < 0)
+		goto cleanup;
+
+	if (target) {
+		if (git_object_owner(target) != repo) {
+			giterr_set(GITERR_OBJECT,
+				"%s_default - The given target does not belong to this repository.", ERROR_MSG);
+			return -1;
+		}
+
+		if ((error = git_object_peel(&commit, target, GIT_OBJ_COMMIT)) < 0 ||
+			(error = git_commit_tree(&tree, (git_commit *)commit)) < 0)
+			goto cleanup;
+	}
+
+	opts.pathspec = *pathspecs;
+	opts.flags = GIT_DIFF_REVERSE;
+
+	if ((error = git_diff_tree_to_index(
+		&diff, repo, tree, index, &opts)) < 0)
+			goto cleanup;
+
+	for (i = 0, max_i = git_diff_num_deltas(diff); i < max_i; ++i) {
+		const git_diff_delta *delta = git_diff_get_delta(diff, i);
+
+		assert(delta->status == GIT_DELTA_ADDED ||
+			delta->status == GIT_DELTA_MODIFIED ||
+			delta->status == GIT_DELTA_CONFLICTED ||
+			delta->status == GIT_DELTA_DELETED);
+
+		error = git_index_conflict_remove(index, delta->old_file.path);
+		if (error < 0) {
+			if (delta->status == GIT_DELTA_ADDED && error == GIT_ENOTFOUND)
+				giterr_clear();
+			else
+				goto cleanup;
+		}
+
+		if (delta->status == GIT_DELTA_DELETED) {
+			if ((error = git_index_remove(index, delta->old_file.path, 0)) < 0)
+				goto cleanup;
+		} else {
+			entry.mode = delta->new_file.mode;
+			git_oid_cpy(&entry.id, &delta->new_file.id);
+			entry.path = (char *)delta->new_file.path;
+
+			if ((error = git_index_add(index, &entry)) < 0)
+				goto cleanup;
+		}
+	}
+
+	error = git_index_write(index);
+
+cleanup:
+	git_object_free(commit);
+	git_tree_free(tree);
+	git_index_free(index);
+	git_diff_free(diff);
+
+	return error;
+}
+
+static int reset(
+	git_repository *repo,
+	const git_object *target,
+	const char *to,
+	git_reset_t reset_type,
+	const git_checkout_options *checkout_opts)
+{
+	git_object *commit = NULL;
+	git_index *index = NULL;
+	git_tree *tree = NULL;
+	int error = 0;
+	git_checkout_options opts = GIT_CHECKOUT_OPTIONS_INIT;
+	git_buf log_message = GIT_BUF_INIT;
+
+	assert(repo && target);
+
+	if (checkout_opts)
+		opts = *checkout_opts;
+
+	if (git_object_owner(target) != repo) {
+		giterr_set(GITERR_OBJECT,
+			"%s - The given target does not belong to this repository.", ERROR_MSG);
+		return -1;
+	}
+
+	if (reset_type != GIT_RESET_SOFT &&
+		(error = git_repository__ensure_not_bare(repo,
+			reset_type == GIT_RESET_MIXED ? "reset mixed" : "reset hard")) < 0)
+		return error;
+
+	if ((error = git_object_peel(&commit, target, GIT_OBJ_COMMIT)) < 0 ||
+		(error = git_repository_index(&index, repo)) < 0 ||
+		(error = git_commit_tree(&tree, (git_commit *)commit)) < 0)
+		goto cleanup;
+
+	if (reset_type == GIT_RESET_SOFT &&
+		(git_repository_state(repo) == GIT_REPOSITORY_STATE_MERGE ||
+		 git_index_has_conflicts(index)))
+	{
+		giterr_set(GITERR_OBJECT, "%s (soft) in the middle of a merge", ERROR_MSG);
+		error = GIT_EUNMERGED;
+		goto cleanup;
+	}
+
+	if ((error = git_buf_printf(&log_message, "reset: moving to %s", to)) < 0)
+		return error;
+
+	if (reset_type == GIT_RESET_HARD) {
+		/* overwrite working directory with the new tree */
+		opts.checkout_strategy = GIT_CHECKOUT_FORCE;
+
+		if ((error = git_checkout_tree(repo, (git_object *)tree, &opts)) < 0)
+			goto cleanup;
+	}
+
+	/* move HEAD to the new target */
+	if ((error = git_reference__update_terminal(repo, GIT_HEAD_FILE,
+		git_object_id(commit), NULL, git_buf_cstr(&log_message))) < 0)
+		goto cleanup;
+
+	if (reset_type > GIT_RESET_SOFT) {
+		/* reset index to the target content */
+
+		if ((error = git_index_read_tree(index, tree)) < 0 ||
+			(error = git_index_write(index)) < 0)
+			goto cleanup;
+
+		if ((error = git_repository_state_cleanup(repo)) < 0) {
+			giterr_set(GITERR_INDEX, "%s - failed to clean up merge data", ERROR_MSG);
+			goto cleanup;
+		}
+	}
+
+cleanup:
+	git_object_free(commit);
+	git_index_free(index);
+	git_tree_free(tree);
+	git_buf_free(&log_message);
+
+	return error;
+}
+
+int git_reset(
+	git_repository *repo,
+	const git_object *target,
+	git_reset_t reset_type,
+	const git_checkout_options *checkout_opts)
+{
+	return reset(repo, target, git_oid_tostr_s(git_object_id(target)), reset_type, checkout_opts);
+}
+
+int git_reset_from_annotated(
+	git_repository *repo,
+	const git_annotated_commit *commit,
+	git_reset_t reset_type,
+	const git_checkout_options *checkout_opts)
+{
+	return reset(repo, (git_object *) commit->commit, commit->description, reset_type, checkout_opts);
+}

vendor/libgit2-sys/libgit2/src/revert.c

diff --git a/vendor/libgit2-sys/libgit2/src/revert.c b/vendor/libgit2-sys/libgit2/src/revert.c
new file mode 100644
index 0000000..54f6d48
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/revert.c
@@ -0,0 +1,232 @@
+/*
+* Copyright (C) the libgit2 contributors. All rights reserved.
+*
+* This file is part of libgit2, distributed under the GNU GPL v2 with
+* a Linking Exception. For full terms see the included COPYING file.
+*/
+
+#include "common.h"
+
+#include "repository.h"
+#include "filebuf.h"
+#include "merge.h"
+#include "index.h"
+
+#include "git2/types.h"
+#include "git2/merge.h"
+#include "git2/revert.h"
+#include "git2/commit.h"
+#include "git2/sys/commit.h"
+
+#define GIT_REVERT_FILE_MODE		0666
+
+static int write_revert_head(
+	git_repository *repo,
+	const char *commit_oidstr)
+{
+	git_filebuf file = GIT_FILEBUF_INIT;
+	git_buf file_path = GIT_BUF_INIT;
+	int error = 0;
+
+	if ((error = git_buf_joinpath(&file_path, repo->gitdir, GIT_REVERT_HEAD_FILE)) >= 0 &&
+		(error = git_filebuf_open(&file, file_path.ptr, GIT_FILEBUF_FORCE, GIT_REVERT_FILE_MODE)) >= 0 &&
+		(error = git_filebuf_printf(&file, "%s\n", commit_oidstr)) >= 0)
+		error = git_filebuf_commit(&file);
+
+	if (error < 0)
+		git_filebuf_cleanup(&file);
+
+	git_buf_free(&file_path);
+
+	return error;
+}
+
+static int write_merge_msg(
+	git_repository *repo,
+	const char *commit_oidstr,
+	const char *commit_msgline)
+{
+	git_filebuf file = GIT_FILEBUF_INIT;
+	git_buf file_path = GIT_BUF_INIT;
+	int error = 0;
+
+	if ((error = git_buf_joinpath(&file_path, repo->gitdir, GIT_MERGE_MSG_FILE)) < 0 ||
+		(error = git_filebuf_open(&file, file_path.ptr, GIT_FILEBUF_FORCE, GIT_REVERT_FILE_MODE)) < 0 ||
+		(error = git_filebuf_printf(&file, "Revert \"%s\"\n\nThis reverts commit %s.\n",
+		commit_msgline, commit_oidstr)) < 0)
+		goto cleanup;
+
+	error = git_filebuf_commit(&file);
+
+cleanup:
+	if (error < 0)
+		git_filebuf_cleanup(&file);
+
+	git_buf_free(&file_path);
+
+	return error;
+}
+
+static int revert_normalize_opts(
+	git_repository *repo,
+	git_revert_options *opts,
+	const git_revert_options *given,
+	const char *their_label)
+{
+	int error = 0;
+	unsigned int default_checkout_strategy = GIT_CHECKOUT_SAFE |
+		GIT_CHECKOUT_ALLOW_CONFLICTS;
+
+	GIT_UNUSED(repo);
+
+	if (given != NULL)
+		memcpy(opts, given, sizeof(git_revert_options));
+	else {
+		git_revert_options default_opts = GIT_REVERT_OPTIONS_INIT;
+		memcpy(opts, &default_opts, sizeof(git_revert_options));
+	}
+
+	if (!opts->checkout_opts.checkout_strategy)
+		opts->checkout_opts.checkout_strategy = default_checkout_strategy;
+
+	if (!opts->checkout_opts.our_label)
+		opts->checkout_opts.our_label = "HEAD";
+
+	if (!opts->checkout_opts.their_label)
+		opts->checkout_opts.their_label = their_label;
+
+	return error;
+}
+
+static int revert_state_cleanup(git_repository *repo)
+{
+	const char *state_files[] = { GIT_REVERT_HEAD_FILE, GIT_MERGE_MSG_FILE };
+
+	return git_repository__cleanup_files(repo, state_files, ARRAY_SIZE(state_files));
+}
+
+static int revert_seterr(git_commit *commit, const char *fmt)
+{
+	char commit_oidstr[GIT_OID_HEXSZ + 1];
+
+	git_oid_fmt(commit_oidstr, git_commit_id(commit));
+	commit_oidstr[GIT_OID_HEXSZ] = '\0';
+
+	giterr_set(GITERR_REVERT, fmt, commit_oidstr);
+
+	return -1;
+}
+
+int git_revert_commit(
+	git_index **out,
+	git_repository *repo,
+	git_commit *revert_commit,
+	git_commit *our_commit,
+	unsigned int mainline,
+	const git_merge_options *merge_opts)
+{
+	git_commit *parent_commit = NULL;
+	git_tree *parent_tree = NULL, *our_tree = NULL, *revert_tree = NULL;
+	int parent = 0, error = 0;
+
+	assert(out && repo && revert_commit && our_commit);
+
+	if (git_commit_parentcount(revert_commit) > 1) {
+		if (!mainline)
+			return revert_seterr(revert_commit,
+				"mainline branch is not specified but %s is a merge commit");
+
+		parent = mainline;
+	} else {
+		if (mainline)
+			return revert_seterr(revert_commit,
+				"mainline branch specified but %s is not a merge commit");
+
+		parent = git_commit_parentcount(revert_commit);
+	}
+
+	if (parent &&
+		((error = git_commit_parent(&parent_commit, revert_commit, (parent - 1))) < 0 ||
+		(error = git_commit_tree(&parent_tree, parent_commit)) < 0))
+		goto done;
+
+	if ((error = git_commit_tree(&revert_tree, revert_commit)) < 0 ||
+		(error = git_commit_tree(&our_tree, our_commit)) < 0)
+		goto done;
+
+	error = git_merge_trees(out, repo, revert_tree, our_tree, parent_tree, merge_opts);
+
+done:
+	git_tree_free(parent_tree);
+	git_tree_free(our_tree);
+	git_tree_free(revert_tree);
+	git_commit_free(parent_commit);
+
+	return error;
+}
+
+int git_revert(
+	git_repository *repo,
+	git_commit *commit,
+	const git_revert_options *given_opts)
+{
+	git_revert_options opts;
+	git_reference *our_ref = NULL;
+	git_commit *our_commit = NULL;
+	char commit_oidstr[GIT_OID_HEXSZ + 1];
+	const char *commit_msg;
+	git_buf their_label = GIT_BUF_INIT;
+	git_index *index = NULL;
+	git_indexwriter indexwriter = GIT_INDEXWRITER_INIT;
+	int error;
+
+	assert(repo && commit);
+
+	GITERR_CHECK_VERSION(given_opts, GIT_REVERT_OPTIONS_VERSION, "git_revert_options");
+
+	if ((error = git_repository__ensure_not_bare(repo, "revert")) < 0)
+		return error;
+
+	git_oid_fmt(commit_oidstr, git_commit_id(commit));
+	commit_oidstr[GIT_OID_HEXSZ] = '\0';
+
+	if ((commit_msg = git_commit_summary(commit)) == NULL) {
+		error = -1;
+		goto on_error;
+	}
+
+	if ((error = git_buf_printf(&their_label, "parent of %.7s... %s", commit_oidstr, commit_msg)) < 0 ||
+		(error = revert_normalize_opts(repo, &opts, given_opts, git_buf_cstr(&their_label))) < 0 ||
+		(error = git_indexwriter_init_for_operation(&indexwriter, repo, &opts.checkout_opts.checkout_strategy)) < 0 ||
+		(error = write_revert_head(repo, commit_oidstr)) < 0 ||
+		(error = write_merge_msg(repo, commit_oidstr, commit_msg)) < 0 ||
+		(error = git_repository_head(&our_ref, repo)) < 0 ||
+		(error = git_reference_peel((git_object **)&our_commit, our_ref, GIT_OBJ_COMMIT)) < 0 ||
+		(error = git_revert_commit(&index, repo, commit, our_commit, opts.mainline, &opts.merge_opts)) < 0 ||
+		(error = git_merge__check_result(repo, index)) < 0 ||
+		(error = git_merge__append_conflicts_to_merge_msg(repo, index)) < 0 ||
+		(error = git_checkout_index(repo, index, &opts.checkout_opts)) < 0 ||
+		(error = git_indexwriter_commit(&indexwriter)) < 0)
+		goto on_error;
+
+	goto done;
+
+on_error:
+	revert_state_cleanup(repo);
+
+done:
+	git_indexwriter_cleanup(&indexwriter);
+	git_index_free(index);
+	git_commit_free(our_commit);
+	git_reference_free(our_ref);
+	git_buf_free(&their_label);
+
+	return error;
+}
+
+int git_revert_init_options(git_revert_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_revert_options, GIT_REVERT_OPTIONS_INIT);
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/revparse.c

diff --git a/vendor/libgit2-sys/libgit2/src/revparse.c b/vendor/libgit2-sys/libgit2/src/revparse.c
new file mode 100644
index 0000000..7cb22f4
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/revparse.c
@@ -0,0 +1,930 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include <assert.h>
+
+#include "buffer.h"
+#include "tree.h"
+#include "refdb.h"
+
+#include "git2.h"
+
+static int maybe_sha_or_abbrev(git_object** out, git_repository *repo, const char *spec, size_t speclen)
+{
+	git_oid oid;
+
+	if (git_oid_fromstrn(&oid, spec, speclen) < 0)
+		return GIT_ENOTFOUND;
+
+	return git_object_lookup_prefix(out, repo, &oid, speclen, GIT_OBJ_ANY);
+}
+
+static int maybe_sha(git_object** out, git_repository *repo, const char *spec)
+{
+	size_t speclen = strlen(spec);
+
+	if (speclen != GIT_OID_HEXSZ)
+		return GIT_ENOTFOUND;
+
+	return maybe_sha_or_abbrev(out, repo, spec, speclen);
+}
+
+static int maybe_abbrev(git_object** out, git_repository *repo, const char *spec)
+{
+	size_t speclen = strlen(spec);
+
+	return maybe_sha_or_abbrev(out, repo, spec, speclen);
+}
+
+static int build_regex(regex_t *regex, const char *pattern)
+{
+	int error;
+
+	if (*pattern == '\0') {
+		giterr_set(GITERR_REGEX, "empty pattern");
+		return GIT_EINVALIDSPEC;
+	}
+
+	error = p_regcomp(regex, pattern, REG_EXTENDED);
+	if (!error)
+		return 0;
+
+	error = giterr_set_regex(regex, error);
+
+	regfree(regex);
+
+	return error;
+}
+
+static int maybe_describe(git_object**out, git_repository *repo, const char *spec)
+{
+	const char *substr;
+	int error;
+	regex_t regex;
+
+	substr = strstr(spec, "-g");
+
+	if (substr == NULL)
+		return GIT_ENOTFOUND;
+
+	if (build_regex(&regex, ".+-[0-9]+-g[0-9a-fA-F]+") < 0)
+		return -1;
+
+	error = regexec(&regex, spec, 0, NULL, 0);
+	regfree(&regex);
+
+	if (error)
+		return GIT_ENOTFOUND;
+
+	return maybe_abbrev(out, repo, substr+2);
+}
+
+static int revparse_lookup_object(
+	git_object **object_out,
+	git_reference **reference_out,
+	git_repository *repo,
+	const char *spec)
+{
+	int error;
+	git_reference *ref;
+
+	if ((error = maybe_sha(object_out, repo, spec)) != GIT_ENOTFOUND)
+		return error;
+
+	error = git_reference_dwim(&ref, repo, spec);
+	if (!error) {
+
+		error = git_object_lookup(
+			object_out, repo, git_reference_target(ref), GIT_OBJ_ANY);
+
+		if (!error)
+			*reference_out = ref;
+
+		return error;
+	}
+
+	if (error != GIT_ENOTFOUND)
+		return error;
+
+	if ((strlen(spec) < GIT_OID_HEXSZ) &&
+		((error = maybe_abbrev(object_out, repo, spec)) != GIT_ENOTFOUND))
+			return error;
+
+	if ((error = maybe_describe(object_out, repo, spec)) != GIT_ENOTFOUND)
+		return error;
+
+	giterr_set(GITERR_REFERENCE, "revspec '%s' not found", spec);
+	return GIT_ENOTFOUND;
+}
+
+static int try_parse_numeric(int *n, const char *curly_braces_content)
+{
+	int32_t content;
+	const char *end_ptr;
+
+	if (git__strtol32(&content, curly_braces_content, &end_ptr, 10) < 0)
+		return -1;
+
+	if (*end_ptr != '\0')
+		return -1;
+
+	*n = (int)content;
+	return 0;
+}
+
+static int retrieve_previously_checked_out_branch_or_revision(git_object **out, git_reference **base_ref, git_repository *repo, const char *identifier, size_t position)
+{
+	git_reference *ref = NULL;
+	git_reflog *reflog = NULL;
+	regex_t preg;
+	int error = -1;
+	size_t i, numentries, cur;
+	const git_reflog_entry *entry;
+	const char *msg;
+	regmatch_t regexmatches[2];
+	git_buf buf = GIT_BUF_INIT;
+
+	cur = position;
+
+	if (*identifier != '\0' || *base_ref != NULL)
+		return GIT_EINVALIDSPEC;
+
+	if (build_regex(&preg, "checkout: moving from (.*) to .*") < 0)
+		return -1;
+
+	if (git_reference_lookup(&ref, repo, GIT_HEAD_FILE) < 0)
+		goto cleanup;
+
+	if (git_reflog_read(&reflog, repo, GIT_HEAD_FILE) < 0)
+		goto cleanup;
+
+	numentries  = git_reflog_entrycount(reflog);
+
+	for (i = 0; i < numentries; i++) {
+		entry = git_reflog_entry_byindex(reflog, i);
+		msg = git_reflog_entry_message(entry);
+		if (!msg)
+			continue;
+
+		if (regexec(&preg, msg, 2, regexmatches, 0))
+			continue;
+
+		cur--;
+
+		if (cur > 0)
+			continue;
+
+		git_buf_put(&buf, msg+regexmatches[1].rm_so, regexmatches[1].rm_eo - regexmatches[1].rm_so);
+
+		if ((error = git_reference_dwim(base_ref, repo, git_buf_cstr(&buf))) == 0)
+			goto cleanup;
+
+		if (error < 0 && error != GIT_ENOTFOUND)
+			goto cleanup;
+
+		error = maybe_abbrev(out, repo, git_buf_cstr(&buf));
+
+		goto cleanup;
+	}
+
+	error = GIT_ENOTFOUND;
+
+cleanup:
+	git_reference_free(ref);
+	git_buf_free(&buf);
+	regfree(&preg);
+	git_reflog_free(reflog);
+	return error;
+}
+
+static int retrieve_oid_from_reflog(git_oid *oid, git_reference *ref, size_t identifier)
+{
+	git_reflog *reflog;
+	size_t numentries;
+	const git_reflog_entry *entry;
+	bool search_by_pos = (identifier <= 100000000);
+
+	if (git_reflog_read(&reflog, git_reference_owner(ref), git_reference_name(ref)) < 0)
+		return -1;
+
+	numentries = git_reflog_entrycount(reflog);
+
+	if (search_by_pos) {
+		if (numentries < identifier + 1)
+			goto notfound;
+
+		entry = git_reflog_entry_byindex(reflog, identifier);
+		git_oid_cpy(oid, git_reflog_entry_id_new(entry));
+	} else {
+		size_t i;
+		git_time commit_time;
+
+		for (i = 0; i < numentries; i++) {
+			entry = git_reflog_entry_byindex(reflog, i);
+			commit_time = git_reflog_entry_committer(entry)->when;
+
+			if (commit_time.time > (git_time_t)identifier)
+				continue;
+
+			git_oid_cpy(oid, git_reflog_entry_id_new(entry));
+			break;
+		}
+
+		if (i == numentries)
+			goto notfound;
+	}
+
+	git_reflog_free(reflog);
+	return 0;
+
+notfound:
+	giterr_set(
+		GITERR_REFERENCE,
+		"reflog for '%s' has only %"PRIuZ" entries, asked for %"PRIuZ,
+		git_reference_name(ref), numentries, identifier);
+
+	git_reflog_free(reflog);
+	return GIT_ENOTFOUND;
+}
+
+static int retrieve_revobject_from_reflog(git_object **out, git_reference **base_ref, git_repository *repo, const char *identifier, size_t position)
+{
+	git_reference *ref;
+	git_oid oid;
+	int error = -1;
+
+	if (*base_ref == NULL) {
+		if ((error = git_reference_dwim(&ref, repo, identifier)) < 0)
+			return error;
+	} else {
+		ref = *base_ref;
+		*base_ref = NULL;
+	}
+
+	if (position == 0) {
+		error = git_object_lookup(out, repo, git_reference_target(ref), GIT_OBJ_ANY);
+		goto cleanup;
+	}
+
+	if ((error = retrieve_oid_from_reflog(&oid, ref, position)) < 0)
+		goto cleanup;
+
+	error = git_object_lookup(out, repo, &oid, GIT_OBJ_ANY);
+
+cleanup:
+	git_reference_free(ref);
+	return error;
+}
+
+static int retrieve_remote_tracking_reference(git_reference **base_ref, const char *identifier, git_repository *repo)
+{
+	git_reference *tracking, *ref;
+	int error = -1;
+
+	if (*base_ref == NULL) {
+		if ((error = git_reference_dwim(&ref, repo, identifier)) < 0)
+			return error;
+	} else {
+		ref = *base_ref;
+		*base_ref = NULL;
+	}
+
+	if (!git_reference_is_branch(ref)) {
+		error = GIT_EINVALIDSPEC;
+		goto cleanup;
+	}
+
+	if ((error = git_branch_upstream(&tracking, ref)) < 0)
+		goto cleanup;
+
+	*base_ref = tracking;
+
+cleanup:
+	git_reference_free(ref);
+	return error;
+}
+
+static int handle_at_syntax(git_object **out, git_reference **ref, const char *spec, size_t identifier_len, git_repository* repo, const char *curly_braces_content)
+{
+	bool is_numeric;
+	int parsed = 0, error = -1;
+	git_buf identifier = GIT_BUF_INIT;
+	git_time_t timestamp;
+
+	assert(*out == NULL);
+
+	if (git_buf_put(&identifier, spec, identifier_len) < 0)
+		return -1;
+
+	is_numeric = !try_parse_numeric(&parsed, curly_braces_content);
+
+	if (*curly_braces_content == '-' && (!is_numeric || parsed == 0)) {
+		error = GIT_EINVALIDSPEC;
+		goto cleanup;
+	}
+
+	if (is_numeric) {
+		if (parsed < 0)
+			error = retrieve_previously_checked_out_branch_or_revision(out, ref, repo, git_buf_cstr(&identifier), -parsed);
+		else
+			error = retrieve_revobject_from_reflog(out, ref, repo, git_buf_cstr(&identifier), parsed);
+
+		goto cleanup;
+	}
+
+	if (!strcmp(curly_braces_content, "u") || !strcmp(curly_braces_content, "upstream")) {
+		error = retrieve_remote_tracking_reference(ref, git_buf_cstr(&identifier), repo);
+
+		goto cleanup;
+	}
+
+	if (git__date_parse(&timestamp, curly_braces_content) < 0)
+		goto cleanup;
+
+	error = retrieve_revobject_from_reflog(out, ref, repo, git_buf_cstr(&identifier), (size_t)timestamp);
+
+cleanup:
+	git_buf_free(&identifier);
+	return error;
+}
+
+static git_otype parse_obj_type(const char *str)
+{
+	if (!strcmp(str, "commit"))
+		return GIT_OBJ_COMMIT;
+
+	if (!strcmp(str, "tree"))
+		return GIT_OBJ_TREE;
+
+	if (!strcmp(str, "blob"))
+		return GIT_OBJ_BLOB;
+
+	if (!strcmp(str, "tag"))
+		return GIT_OBJ_TAG;
+
+	return GIT_OBJ_BAD;
+}
+
+static int dereference_to_non_tag(git_object **out, git_object *obj)
+{
+	if (git_object_type(obj) == GIT_OBJ_TAG)
+		return git_tag_peel(out, (git_tag *)obj);
+
+	return git_object_dup(out, obj);
+}
+
+static int handle_caret_parent_syntax(git_object **out, git_object *obj, int n)
+{
+	git_object *temp_commit = NULL;
+	int error;
+
+	if ((error = git_object_peel(&temp_commit, obj, GIT_OBJ_COMMIT)) < 0)
+		return (error == GIT_EAMBIGUOUS || error == GIT_ENOTFOUND) ?
+			GIT_EINVALIDSPEC : error;
+
+	if (n == 0) {
+		*out = temp_commit;
+		return 0;
+	}
+
+	error = git_commit_parent((git_commit **)out, (git_commit*)temp_commit, n - 1);
+
+	git_object_free(temp_commit);
+	return error;
+}
+
+static int handle_linear_syntax(git_object **out, git_object *obj, int n)
+{
+	git_object *temp_commit = NULL;
+	int error;
+
+	if ((error = git_object_peel(&temp_commit, obj, GIT_OBJ_COMMIT)) < 0)
+		return (error == GIT_EAMBIGUOUS || error == GIT_ENOTFOUND) ?
+			GIT_EINVALIDSPEC : error;
+
+	error = git_commit_nth_gen_ancestor((git_commit **)out, (git_commit*)temp_commit, n);
+
+	git_object_free(temp_commit);
+	return error;
+}
+
+static int handle_colon_syntax(
+	git_object **out,
+	git_object *obj,
+	const char *path)
+{
+	git_object *tree;
+	int error = -1;
+	git_tree_entry *entry = NULL;
+
+	if ((error = git_object_peel(&tree, obj, GIT_OBJ_TREE)) < 0)
+		return error == GIT_ENOTFOUND ? GIT_EINVALIDSPEC : error;
+
+	if (*path == '\0') {
+		*out = tree;
+		return 0;
+	}
+
+	/*
+	 * TODO: Handle the relative path syntax
+	 * (:./relative/path and :../relative/path)
+	 */
+	if ((error = git_tree_entry_bypath(&entry, (git_tree *)tree, path)) < 0)
+		goto cleanup;
+
+	error = git_tree_entry_to_object(out, git_object_owner(tree), entry);
+
+cleanup:
+	git_tree_entry_free(entry);
+	git_object_free(tree);
+
+	return error;
+}
+
+static int walk_and_search(git_object **out, git_revwalk *walk, regex_t *regex)
+{
+	int error;
+	git_oid oid;
+	git_object *obj;
+
+	while (!(error = git_revwalk_next(&oid, walk))) {
+
+		error = git_object_lookup(&obj, git_revwalk_repository(walk), &oid, GIT_OBJ_COMMIT);
+		if ((error < 0) && (error != GIT_ENOTFOUND))
+			return -1;
+
+		if (!regexec(regex, git_commit_message((git_commit*)obj), 0, NULL, 0)) {
+			*out = obj;
+			return 0;
+		}
+
+		git_object_free(obj);
+	}
+
+	if (error < 0 && error == GIT_ITEROVER)
+		error = GIT_ENOTFOUND;
+
+	return error;
+}
+
+static int handle_grep_syntax(git_object **out, git_repository *repo, const git_oid *spec_oid, const char *pattern)
+{
+	regex_t preg;
+	git_revwalk *walk = NULL;
+	int error;
+
+	if ((error = build_regex(&preg, pattern)) < 0)
+		return error;
+
+	if ((error = git_revwalk_new(&walk, repo)) < 0)
+		goto cleanup;
+
+	git_revwalk_sorting(walk, GIT_SORT_TIME);
+
+	if (spec_oid == NULL) {
+		if ((error = git_revwalk_push_glob(walk, "refs/*")) < 0)
+			goto cleanup;
+	} else if ((error = git_revwalk_push(walk, spec_oid)) < 0)
+			goto cleanup;
+
+	error = walk_and_search(out, walk, &preg);
+
+cleanup:
+	regfree(&preg);
+	git_revwalk_free(walk);
+
+	return error;
+}
+
+static int handle_caret_curly_syntax(git_object **out, git_object *obj, const char *curly_braces_content)
+{
+	git_otype expected_type;
+
+	if (*curly_braces_content == '\0')
+		return dereference_to_non_tag(out, obj);
+
+	if (*curly_braces_content == '/')
+		return handle_grep_syntax(out, git_object_owner(obj), git_object_id(obj), curly_braces_content + 1);
+
+	expected_type = parse_obj_type(curly_braces_content);
+
+	if (expected_type == GIT_OBJ_BAD)
+		return GIT_EINVALIDSPEC;
+
+	return git_object_peel(out, obj, expected_type);
+}
+
+static int extract_curly_braces_content(git_buf *buf, const char *spec, size_t *pos)
+{
+	git_buf_clear(buf);
+
+	assert(spec[*pos] == '^' || spec[*pos] == '@');
+
+	(*pos)++;
+
+	if (spec[*pos] == '\0' || spec[*pos] != '{')
+		return GIT_EINVALIDSPEC;
+
+	(*pos)++;
+
+	while (spec[*pos] != '}') {
+		if (spec[*pos] == '\0')
+			return GIT_EINVALIDSPEC;
+
+		git_buf_putc(buf, spec[(*pos)++]);
+	}
+
+	(*pos)++;
+
+	return 0;
+}
+
+static int extract_path(git_buf *buf, const char *spec, size_t *pos)
+{
+	git_buf_clear(buf);
+
+	assert(spec[*pos] == ':');
+
+	(*pos)++;
+
+	if (git_buf_puts(buf, spec + *pos) < 0)
+		return -1;
+
+	*pos += git_buf_len(buf);
+
+	return 0;
+}
+
+static int extract_how_many(int *n, const char *spec, size_t *pos)
+{
+	const char *end_ptr;
+	int parsed, accumulated;
+	char kind = spec[*pos];
+
+	assert(spec[*pos] == '^' || spec[*pos] == '~');
+
+	accumulated = 0;
+
+	do {
+		do {
+			(*pos)++;
+			accumulated++;
+		} while (spec[(*pos)] == kind && kind == '~');
+
+		if (git__isdigit(spec[*pos])) {
+			if (git__strtol32(&parsed, spec + *pos, &end_ptr, 10) < 0)
+				return GIT_EINVALIDSPEC;
+
+			accumulated += (parsed - 1);
+			*pos = end_ptr - spec;
+		}
+
+	} 	while (spec[(*pos)] == kind && kind == '~');
+
+	*n = accumulated;
+
+	return 0;
+}
+
+static int object_from_reference(git_object **object, git_reference *reference)
+{
+	git_reference *resolved = NULL;
+	int error;
+
+	if (git_reference_resolve(&resolved, reference) < 0)
+		return -1;
+
+	error = git_object_lookup(object, reference->db->repo, git_reference_target(resolved), GIT_OBJ_ANY);
+	git_reference_free(resolved);
+
+	return error;
+}
+
+static int ensure_base_rev_loaded(git_object **object, git_reference **reference, const char *spec, size_t identifier_len, git_repository *repo, bool allow_empty_identifier)
+{
+	int error;
+	git_buf identifier = GIT_BUF_INIT;
+
+	if (*object != NULL)
+		return 0;
+
+	if (*reference != NULL)
+		return object_from_reference(object, *reference);
+
+	if (!allow_empty_identifier && identifier_len == 0)
+		return GIT_EINVALIDSPEC;
+
+	if (git_buf_put(&identifier, spec, identifier_len) < 0)
+		return -1;
+
+	error = revparse_lookup_object(object, reference, repo, git_buf_cstr(&identifier));
+	git_buf_free(&identifier);
+
+	return error;
+}
+
+static int ensure_base_rev_is_not_known_yet(git_object *object)
+{
+	if (object == NULL)
+		return 0;
+
+	return GIT_EINVALIDSPEC;
+}
+
+static bool any_left_hand_identifier(git_object *object, git_reference *reference, size_t identifier_len)
+{
+	if (object != NULL)
+		return true;
+
+	if (reference != NULL)
+		return true;
+
+	if (identifier_len > 0)
+		return true;
+
+	return false;
+}
+
+static int ensure_left_hand_identifier_is_not_known_yet(git_object *object, git_reference *reference)
+{
+	if (!ensure_base_rev_is_not_known_yet(object) && reference == NULL)
+		return 0;
+
+	return GIT_EINVALIDSPEC;
+}
+
+int revparse__ext(
+	git_object **object_out,
+	git_reference **reference_out,
+	size_t *identifier_len_out,
+	git_repository *repo,
+	const char *spec)
+{
+	size_t pos = 0, identifier_len = 0;
+	int error = -1, n;
+	git_buf buf = GIT_BUF_INIT;
+
+	git_reference *reference = NULL;
+	git_object *base_rev = NULL;
+
+	bool should_return_reference = true;
+
+	assert(object_out && reference_out && repo && spec);
+
+	*object_out = NULL;
+	*reference_out = NULL;
+
+	while (spec[pos]) {
+		switch (spec[pos]) {
+		case '^':
+			should_return_reference = false;
+
+			if ((error = ensure_base_rev_loaded(&base_rev, &reference, spec, identifier_len, repo, false)) < 0)
+				goto cleanup;
+
+			if (spec[pos+1] == '{') {
+				git_object *temp_object = NULL;
+
+				if ((error = extract_curly_braces_content(&buf, spec, &pos)) < 0)
+					goto cleanup;
+
+				if ((error = handle_caret_curly_syntax(&temp_object, base_rev, git_buf_cstr(&buf))) < 0)
+					goto cleanup;
+
+				git_object_free(base_rev);
+				base_rev = temp_object;
+			} else {
+				git_object *temp_object = NULL;
+
+				if ((error = extract_how_many(&n, spec, &pos)) < 0)
+					goto cleanup;
+
+				if ((error = handle_caret_parent_syntax(&temp_object, base_rev, n)) < 0)
+					goto cleanup;
+
+				git_object_free(base_rev);
+				base_rev = temp_object;
+			}
+			break;
+
+		case '~':
+		{
+			git_object *temp_object = NULL;
+
+			should_return_reference = false;
+
+			if ((error = extract_how_many(&n, spec, &pos)) < 0)
+				goto cleanup;
+
+			if ((error = ensure_base_rev_loaded(&base_rev, &reference, spec, identifier_len, repo, false)) < 0)
+				goto cleanup;
+
+			if ((error = handle_linear_syntax(&temp_object, base_rev, n)) < 0)
+				goto cleanup;
+
+			git_object_free(base_rev);
+			base_rev = temp_object;
+			break;
+		}
+
+		case ':':
+		{
+			git_object *temp_object = NULL;
+
+			should_return_reference = false;
+
+			if ((error = extract_path(&buf, spec, &pos)) < 0)
+				goto cleanup;
+
+			if (any_left_hand_identifier(base_rev, reference, identifier_len)) {
+				if ((error = ensure_base_rev_loaded(&base_rev, &reference, spec, identifier_len, repo, true)) < 0)
+					goto cleanup;
+
+				if ((error = handle_colon_syntax(&temp_object, base_rev, git_buf_cstr(&buf))) < 0)
+					goto cleanup;
+			} else {
+				if (*git_buf_cstr(&buf) == '/') {
+					if ((error = handle_grep_syntax(&temp_object, repo, NULL, git_buf_cstr(&buf) + 1)) < 0)
+						goto cleanup;
+				} else {
+
+					/*
+					 * TODO: support merge-stage path lookup (":2:Makefile")
+					 * and plain index blob lookup (:i-am/a/blob)
+					 */
+					giterr_set(GITERR_INVALID, "unimplemented");
+					error = GIT_ERROR;
+					goto cleanup;
+				}
+			}
+
+			git_object_free(base_rev);
+			base_rev = temp_object;
+			break;
+		}
+
+		case '@':
+			if (spec[pos+1] == '{') {
+				git_object *temp_object = NULL;
+
+				if ((error = extract_curly_braces_content(&buf, spec, &pos)) < 0)
+					goto cleanup;
+
+				if ((error = ensure_base_rev_is_not_known_yet(base_rev)) < 0)
+					goto cleanup;
+
+				if ((error = handle_at_syntax(&temp_object, &reference, spec, identifier_len, repo, git_buf_cstr(&buf))) < 0)
+					goto cleanup;
+
+				if (temp_object != NULL)
+					base_rev = temp_object;
+				break;
+			}
+			/* fall through */
+
+		default:
+			if ((error = ensure_left_hand_identifier_is_not_known_yet(base_rev, reference)) < 0)
+				goto cleanup;
+
+			pos++;
+			identifier_len++;
+		}
+	}
+
+	if ((error = ensure_base_rev_loaded(&base_rev, &reference, spec, identifier_len, repo, false)) < 0)
+		goto cleanup;
+
+	if (!should_return_reference) {
+		git_reference_free(reference);
+		reference = NULL;
+	}
+
+	*object_out = base_rev;
+	*reference_out = reference;
+	*identifier_len_out = identifier_len;
+	error = 0;
+
+cleanup:
+	if (error) {
+		if (error == GIT_EINVALIDSPEC)
+			giterr_set(GITERR_INVALID,
+				"failed to parse revision specifier - Invalid pattern '%s'", spec);
+
+		git_object_free(base_rev);
+		git_reference_free(reference);
+	}
+
+	git_buf_free(&buf);
+	return error;
+}
+
+int git_revparse_ext(
+	git_object **object_out,
+	git_reference **reference_out,
+	git_repository *repo,
+	const char *spec)
+{
+	int error;
+	size_t identifier_len;
+	git_object *obj = NULL;
+	git_reference *ref = NULL;
+
+	if ((error = revparse__ext(&obj, &ref, &identifier_len, repo, spec)) < 0)
+		goto cleanup;
+
+	*object_out = obj;
+	*reference_out = ref;
+	GIT_UNUSED(identifier_len);
+
+	return 0;
+
+cleanup:
+	git_object_free(obj);
+	git_reference_free(ref);
+	return error;
+}
+
+int git_revparse_single(git_object **out, git_repository *repo, const char *spec)
+{
+	int error;
+	git_object *obj = NULL;
+	git_reference *ref = NULL;
+
+	*out = NULL;
+
+	if ((error = git_revparse_ext(&obj, &ref, repo, spec)) < 0)
+		goto cleanup;
+
+	git_reference_free(ref);
+
+	*out = obj;
+
+	return 0;
+
+cleanup:
+	git_object_free(obj);
+	git_reference_free(ref);
+	return error;
+}
+
+int git_revparse(
+	git_revspec *revspec,
+	git_repository *repo,
+	const char *spec)
+{
+	const char *dotdot;
+	int error = 0;
+
+	assert(revspec && repo && spec);
+
+	memset(revspec, 0x0, sizeof(*revspec));
+
+	if ((dotdot = strstr(spec, "..")) != NULL) {
+		char *lstr;
+		const char *rstr;
+		revspec->flags = GIT_REVPARSE_RANGE;
+
+		/*
+		 * Following git.git, don't allow '..' because it makes command line
+		 * arguments which can be either paths or revisions ambiguous when the
+		 * path is almost certainly intended. The empty range '...' is still
+		 * allowed.
+		 */
+		if (!git__strcmp(spec, "..")) {
+			giterr_set(GITERR_INVALID, "Invalid pattern '..'");
+			return GIT_EINVALIDSPEC;
+		}
+
+		lstr = git__substrdup(spec, dotdot - spec);
+		rstr = dotdot + 2;
+		if (dotdot[2] == '.') {
+			revspec->flags |= GIT_REVPARSE_MERGE_BASE;
+			rstr++;
+		}
+
+		error = git_revparse_single(
+			&revspec->from,
+			repo,
+			*lstr == '\0' ? "HEAD" : lstr);
+
+		if (!error) {
+			error = git_revparse_single(
+				&revspec->to,
+				repo,
+				*rstr == '\0' ? "HEAD" : rstr);
+		}
+
+		git__free((void*)lstr);
+	} else {
+		revspec->flags = GIT_REVPARSE_SINGLE;
+		error = git_revparse_single(&revspec->from, repo, spec);
+	}
+
+	return error;
+}

vendor/libgit2-sys/libgit2/src/revwalk.c

diff --git a/vendor/libgit2-sys/libgit2/src/revwalk.c b/vendor/libgit2-sys/libgit2/src/revwalk.c
new file mode 100644
index 0000000..eb228a5
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/revwalk.c
@@ -0,0 +1,731 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "revwalk.h"
+
+#include "commit.h"
+#include "odb.h"
+#include "pool.h"
+
+#include "git2/revparse.h"
+#include "merge.h"
+#include "vector.h"
+
+git_commit_list_node *git_revwalk__commit_lookup(
+	git_revwalk *walk, const git_oid *oid)
+{
+	git_commit_list_node *commit;
+	khiter_t pos;
+	int ret;
+
+	/* lookup and reserve space if not already present */
+	pos = git_oidmap_lookup_index(walk->commits, oid);
+	if (git_oidmap_valid_index(walk->commits, pos))
+		return git_oidmap_value_at(walk->commits, pos);
+
+	commit = git_commit_list_alloc_node(walk);
+	if (commit == NULL)
+		return NULL;
+
+	git_oid_cpy(&commit->oid, oid);
+
+	pos = git_oidmap_put(walk->commits, &commit->oid, &ret);
+	assert(ret != 0);
+	git_oidmap_set_value_at(walk->commits, pos, commit);
+
+	return commit;
+}
+
+static int push_commit(git_revwalk *walk, const git_oid *oid, int uninteresting, int from_glob)
+{
+	git_oid commit_id;
+	int error;
+	git_object *obj, *oobj;
+	git_commit_list_node *commit;
+	git_commit_list *list;
+
+	if ((error = git_object_lookup(&oobj, walk->repo, oid, GIT_OBJ_ANY)) < 0)
+		return error;
+
+	error = git_object_peel(&obj, oobj, GIT_OBJ_COMMIT);
+	git_object_free(oobj);
+
+	if (error == GIT_ENOTFOUND || error == GIT_EINVALIDSPEC || error == GIT_EPEEL) {
+		/* If this comes from e.g. push_glob("tags"), ignore this */
+		if (from_glob)
+			return 0;
+
+		giterr_set(GITERR_INVALID, "object is not a committish");
+		return -1;
+	}
+	if (error < 0)
+		return error;
+
+	git_oid_cpy(&commit_id, git_object_id(obj));
+	git_object_free(obj);
+
+	commit = git_revwalk__commit_lookup(walk, &commit_id);
+	if (commit == NULL)
+		return -1; /* error already reported by failed lookup */
+
+	/* A previous hide already told us we don't want this commit  */
+	if (commit->uninteresting)
+		return 0;
+
+	if (uninteresting)
+		walk->did_hide = 1;
+	else
+		walk->did_push = 1;
+
+	commit->uninteresting = uninteresting;
+	list = walk->user_input;
+	if (git_commit_list_insert(commit, &list) == NULL) {
+		giterr_set_oom();
+		return -1;
+	}
+
+	walk->user_input = list;
+
+	return 0;
+}
+
+int git_revwalk_push(git_revwalk *walk, const git_oid *oid)
+{
+	assert(walk && oid);
+	return push_commit(walk, oid, 0, false);
+}
+
+
+int git_revwalk_hide(git_revwalk *walk, const git_oid *oid)
+{
+	assert(walk && oid);
+	return push_commit(walk, oid, 1, false);
+}
+
+static int push_ref(git_revwalk *walk, const char *refname, int hide, int from_glob)
+{
+	git_oid oid;
+
+	if (git_reference_name_to_id(&oid, walk->repo, refname) < 0)
+		return -1;
+
+	return push_commit(walk, &oid, hide, from_glob);
+}
+
+static int push_glob(git_revwalk *walk, const char *glob, int hide)
+{
+	int error = 0;
+	git_buf buf = GIT_BUF_INIT;
+	git_reference *ref;
+	git_reference_iterator *iter;
+	size_t wildcard;
+
+	assert(walk && glob);
+
+	/* refs/ is implied if not given in the glob */
+	if (git__prefixcmp(glob, GIT_REFS_DIR) != 0)
+		git_buf_joinpath(&buf, GIT_REFS_DIR, glob);
+	else
+		git_buf_puts(&buf, glob);
+	GITERR_CHECK_ALLOC_BUF(&buf);
+
+	/* If no '?', '*' or '[' exist, we append '/ *' to the glob */
+	wildcard = strcspn(glob, "?*[");
+	if (!glob[wildcard])
+		git_buf_put(&buf, "/*", 2);
+
+	if ((error = git_reference_iterator_glob_new(&iter, walk->repo, buf.ptr)) < 0)
+		goto out;
+
+	while ((error = git_reference_next(&ref, iter)) == 0) {
+		error = push_ref(walk, git_reference_name(ref), hide, true);
+		git_reference_free(ref);
+		if (error < 0)
+			break;
+	}
+	git_reference_iterator_free(iter);
+
+	if (error == GIT_ITEROVER)
+		error = 0;
+out:
+	git_buf_free(&buf);
+	return error;
+}
+
+int git_revwalk_push_glob(git_revwalk *walk, const char *glob)
+{
+	assert(walk && glob);
+	return push_glob(walk, glob, 0);
+}
+
+int git_revwalk_hide_glob(git_revwalk *walk, const char *glob)
+{
+	assert(walk && glob);
+	return push_glob(walk, glob, 1);
+}
+
+int git_revwalk_push_head(git_revwalk *walk)
+{
+	assert(walk);
+	return push_ref(walk, GIT_HEAD_FILE, 0, false);
+}
+
+int git_revwalk_hide_head(git_revwalk *walk)
+{
+	assert(walk);
+	return push_ref(walk, GIT_HEAD_FILE, 1, false);
+}
+
+int git_revwalk_push_ref(git_revwalk *walk, const char *refname)
+{
+	assert(walk && refname);
+	return push_ref(walk, refname, 0, false);
+}
+
+int git_revwalk_push_range(git_revwalk *walk, const char *range)
+{
+	git_revspec revspec;
+	int error = 0;
+
+	if ((error = git_revparse(&revspec, walk->repo, range)))
+		return error;
+
+	if (revspec.flags & GIT_REVPARSE_MERGE_BASE) {
+		/* TODO: support "<commit>...<commit>" */
+		giterr_set(GITERR_INVALID, "symmetric differences not implemented in revwalk");
+		return GIT_EINVALIDSPEC;
+	}
+
+	if ((error = push_commit(walk, git_object_id(revspec.from), 1, false)))
+		goto out;
+
+	error = push_commit(walk, git_object_id(revspec.to), 0, false);
+
+out:
+	git_object_free(revspec.from);
+	git_object_free(revspec.to);
+	return error;
+}
+
+int git_revwalk_hide_ref(git_revwalk *walk, const char *refname)
+{
+	assert(walk && refname);
+	return push_ref(walk, refname, 1, false);
+}
+
+static int revwalk_enqueue_timesort(git_revwalk *walk, git_commit_list_node *commit)
+{
+	return git_pqueue_insert(&walk->iterator_time, commit);
+}
+
+static int revwalk_enqueue_unsorted(git_revwalk *walk, git_commit_list_node *commit)
+{
+	return git_commit_list_insert(commit, &walk->iterator_rand) ? 0 : -1;
+}
+
+static int revwalk_next_timesort(git_commit_list_node **object_out, git_revwalk *walk)
+{
+	git_commit_list_node *next;
+
+	while ((next = git_pqueue_pop(&walk->iterator_time)) != NULL) {
+		/* Some commits might become uninteresting after being added to the list */
+		if (!next->uninteresting) {
+			*object_out = next;
+			return 0;
+		}
+	}
+
+	giterr_clear();
+	return GIT_ITEROVER;
+}
+
+static int revwalk_next_unsorted(git_commit_list_node **object_out, git_revwalk *walk)
+{
+	git_commit_list_node *next;
+
+	while ((next = git_commit_list_pop(&walk->iterator_rand)) != NULL) {
+		/* Some commits might become uninteresting after being added to the list */
+		if (!next->uninteresting) {
+			*object_out = next;
+			return 0;
+		}
+	}
+
+	giterr_clear();
+	return GIT_ITEROVER;
+}
+
+static int revwalk_next_toposort(git_commit_list_node **object_out, git_revwalk *walk)
+{
+	git_commit_list_node *next;
+
+	while ((next = git_commit_list_pop(&walk->iterator_topo)) != NULL) {
+		/* Some commits might become uninteresting after being added to the list */
+		if (!next->uninteresting) {
+			*object_out = next;
+			return 0;
+		}
+	}
+
+	giterr_clear();
+	return GIT_ITEROVER;
+}
+
+static int revwalk_next_reverse(git_commit_list_node **object_out, git_revwalk *walk)
+{
+	*object_out = git_commit_list_pop(&walk->iterator_reverse);
+	return *object_out ? 0 : GIT_ITEROVER;
+}
+
+static void mark_parents_uninteresting(git_commit_list_node *commit)
+{
+	unsigned short i;
+	git_commit_list *parents = NULL;
+
+	for (i = 0; i < commit->out_degree; i++)
+		git_commit_list_insert(commit->parents[i], &parents);
+
+
+	while (parents) {
+		commit = git_commit_list_pop(&parents);
+
+		while (commit) {
+			if (commit->uninteresting)
+				break;
+
+			commit->uninteresting = 1;
+			/*
+			 * If we've reached this commit some other way
+			 * already, we need to mark its parents uninteresting
+			 * as well.
+			 */
+			if (!commit->parents)
+				break;
+
+			for (i = 0; i < commit->out_degree; i++)
+				git_commit_list_insert(commit->parents[i], &parents);
+			commit = commit->parents[0];
+		}
+	}
+}
+
+static int add_parents_to_list(git_revwalk *walk, git_commit_list_node *commit, git_commit_list **list)
+{
+	unsigned short i;
+	int error;
+
+	if (commit->added)
+		return 0;
+
+	commit->added = 1;
+
+	/*
+	 * Go full on in the uninteresting case as we want to include
+	 * as many of these as we can.
+	 *
+	 * Usually we haven't parsed the parent of a parent, but if we
+	 * have it we reached it via other means so we want to mark
+	 * its parents recursively too.
+	 */
+	if (commit->uninteresting) {
+		for (i = 0; i < commit->out_degree; i++) {
+			git_commit_list_node *p = commit->parents[i];
+			p->uninteresting = 1;
+
+			/* git does it gently here, but we don't like missing objects */
+			if ((error = git_commit_list_parse(walk, p)) < 0)
+				return error;
+
+			if (p->parents)
+				mark_parents_uninteresting(p);
+
+			p->seen = 1;
+			git_commit_list_insert_by_date(p, list);
+		}
+
+		return 0;
+	}
+
+	/*
+	 * Now on to what we do if the commit is indeed
+	 * interesting. Here we do want things like first-parent take
+	 * effect as this is what we'll be showing.
+	 */
+	for (i = 0; i < commit->out_degree; i++) {
+		git_commit_list_node *p = commit->parents[i];
+
+		if ((error = git_commit_list_parse(walk, p)) < 0)
+			return error;
+
+		if (walk->hide_cb && walk->hide_cb(&p->oid, walk->hide_cb_payload))
+			continue;
+
+		if (!p->seen) {
+			p->seen = 1;
+			git_commit_list_insert_by_date(p, list);
+		}
+
+		if (walk->first_parent)
+			break;
+	}
+	return 0;
+}
+
+/* How many unintersting commits we want to look at after we run out of interesting ones */
+#define SLOP 5
+
+static int still_interesting(git_commit_list *list, int64_t time, int slop)
+{
+	/* The empty list is pretty boring */
+	if (!list)
+		return 0;
+
+	for (; list; list = list->next) {
+		/*
+		 * If the destination list has commits with an earlier date than
+		 * our source or if it still contains interesting commits we
+		 * want to continue looking.
+		 */
+		if (!list->item->uninteresting || list->item->time > time)
+			return SLOP;
+	}
+
+	/* Everything's uninteresting, reduce the count */
+	return slop - 1;
+}
+
+static int limit_list(git_commit_list **out, git_revwalk *walk, git_commit_list *commits)
+{
+	int error, slop = SLOP;
+	int64_t time = ~0ll;
+	git_commit_list *list = commits;
+	git_commit_list *newlist = NULL;
+	git_commit_list **p = &newlist;
+
+	while (list) {
+		git_commit_list_node *commit = git_commit_list_pop(&list);
+
+		if ((error = add_parents_to_list(walk, commit, &list)) < 0)
+			return error;
+
+		if (commit->uninteresting) {
+			mark_parents_uninteresting(commit);
+
+			slop = still_interesting(list, time, slop);
+			if (slop)
+				continue;
+
+			break;
+		}
+
+		if (!commit->uninteresting && walk->hide_cb && walk->hide_cb(&commit->oid, walk->hide_cb_payload))
+				continue;
+
+		time = commit->time;
+		p = &git_commit_list_insert(commit, p)->next;
+	}
+
+	git_commit_list_free(&list);
+	*out = newlist;
+	return 0;
+}
+
+static int sort_in_topological_order(git_commit_list **out, git_revwalk *walk, git_commit_list *list)
+{
+	git_commit_list *ll = NULL, *newlist, **pptr;
+	git_commit_list_node *next;
+	git_pqueue queue;
+	git_vector_cmp queue_cmp = NULL;
+	unsigned short i;
+	int error;
+
+	if (walk->sorting & GIT_SORT_TIME)
+		queue_cmp = git_commit_list_time_cmp;
+
+	if ((error = git_pqueue_init(&queue, 0, 8, queue_cmp)))
+		return error;
+
+	/*
+	 * Start by resetting the in-degree to 1 for the commits in
+	 * our list. We want to go through this list again, so we
+	 * store it in the commit list as we extract it from the lower
+	 * machinery.
+	 */
+	for (ll = list; ll; ll = ll->next) {
+		ll->item->in_degree = 1;
+	}
+
+	/*
+	 * Count up how many children each commit has. We limit
+	 * ourselves to those commits in the original list (in-degree
+	 * of 1) avoiding setting it for any parent that was hidden.
+	 */
+	for(ll = list; ll; ll = ll->next) {
+		for (i = 0; i < ll->item->out_degree; ++i) {
+			git_commit_list_node *parent = ll->item->parents[i];
+			if (parent->in_degree)
+				parent->in_degree++;
+		}
+	}
+
+	/*
+	 * Now we find the tips i.e. those not reachable from any other node
+	 * i.e. those which still have an in-degree of 1.
+	 */
+	for(ll = list; ll; ll = ll->next) {
+		if (ll->item->in_degree == 1) {
+			if ((error = git_pqueue_insert(&queue, ll->item)))
+				goto cleanup;
+		}
+	}
+
+	/*
+	 * We need to output the tips in the order that they came out of the
+	 * traversal, so if we're not doing time-sorting, we need to reverse the
+	 * pqueue in order to get them to come out as we inserted them.
+	 */
+	if ((walk->sorting & GIT_SORT_TIME) == 0)
+		git_pqueue_reverse(&queue);
+
+
+	pptr = &newlist;
+	newlist = NULL;
+	while ((next = git_pqueue_pop(&queue)) != NULL) {
+		for (i = 0; i < next->out_degree; ++i) {
+			git_commit_list_node *parent = next->parents[i];
+			if (parent->in_degree == 0)
+				continue;
+
+			if (--parent->in_degree == 1) {
+				if ((error = git_pqueue_insert(&queue, parent)))
+					goto cleanup;
+			}
+		}
+
+		/* All the children of 'item' have been emitted (since we got to it via the priority queue) */
+		next->in_degree = 0;
+
+		pptr = &git_commit_list_insert(next, pptr)->next;
+	}
+
+	*out = newlist;
+	error = 0;
+
+cleanup:
+	git_pqueue_free(&queue);
+	return error;
+}
+
+static int prepare_walk(git_revwalk *walk)
+{
+	int error;
+	git_commit_list *list, *commits = NULL;
+	git_commit_list_node *next;
+
+	/* If there were no pushes, we know that the walk is already over */
+	if (!walk->did_push) {
+		giterr_clear();
+		return GIT_ITEROVER;
+	}
+
+	for (list = walk->user_input; list; list = list->next) {
+		git_commit_list_node *commit = list->item;
+		if ((error = git_commit_list_parse(walk, commit)) < 0)
+			return error;
+
+		if (commit->uninteresting)
+			mark_parents_uninteresting(commit);
+
+		if (!commit->seen) {
+			commit->seen = 1;
+			git_commit_list_insert(commit, &commits);
+		}
+	}
+
+	if ((error = limit_list(&commits, walk, commits)) < 0)
+		return error;
+
+	if (walk->sorting & GIT_SORT_TOPOLOGICAL) {
+		error = sort_in_topological_order(&walk->iterator_topo, walk, commits);
+		git_commit_list_free(&commits);
+
+		if (error < 0)
+			return error;
+
+		walk->get_next = &revwalk_next_toposort;
+	} else if (walk->sorting & GIT_SORT_TIME) {
+		for (list = commits; list && !error; list = list->next)
+			error = walk->enqueue(walk, list->item);
+
+		git_commit_list_free(&commits);
+
+		if (error < 0)
+			return error;
+	} else {
+		walk->iterator_rand = commits;
+		walk->get_next = revwalk_next_unsorted;
+	}
+
+	if (walk->sorting & GIT_SORT_REVERSE) {
+
+		while ((error = walk->get_next(&next, walk)) == 0)
+			if (git_commit_list_insert(next, &walk->iterator_reverse) == NULL)
+				return -1;
+
+		if (error != GIT_ITEROVER)
+			return error;
+
+		walk->get_next = &revwalk_next_reverse;
+	}
+
+	walk->walking = 1;
+	return 0;
+}
+
+
+int git_revwalk_new(git_revwalk **revwalk_out, git_repository *repo)
+{
+	git_revwalk *walk = git__calloc(1, sizeof(git_revwalk));
+	GITERR_CHECK_ALLOC(walk);
+
+	walk->commits = git_oidmap_alloc();
+	GITERR_CHECK_ALLOC(walk->commits);
+
+	if (git_pqueue_init(&walk->iterator_time, 0, 8, git_commit_list_time_cmp) < 0)
+		return -1;
+
+	git_pool_init(&walk->commit_pool, COMMIT_ALLOC);
+	walk->get_next = &revwalk_next_unsorted;
+	walk->enqueue = &revwalk_enqueue_unsorted;
+
+	walk->repo = repo;
+
+	if (git_repository_odb(&walk->odb, repo) < 0) {
+		git_revwalk_free(walk);
+		return -1;
+	}
+
+	*revwalk_out = walk;
+	return 0;
+}
+
+void git_revwalk_free(git_revwalk *walk)
+{
+	if (walk == NULL)
+		return;
+
+	git_revwalk_reset(walk);
+	git_odb_free(walk->odb);
+
+	git_oidmap_free(walk->commits);
+	git_pool_clear(&walk->commit_pool);
+	git_pqueue_free(&walk->iterator_time);
+	git__free(walk);
+}
+
+git_repository *git_revwalk_repository(git_revwalk *walk)
+{
+	assert(walk);
+	return walk->repo;
+}
+
+void git_revwalk_sorting(git_revwalk *walk, unsigned int sort_mode)
+{
+	assert(walk);
+
+	if (walk->walking)
+		git_revwalk_reset(walk);
+
+	walk->sorting = sort_mode;
+
+	if (walk->sorting & GIT_SORT_TIME) {
+		walk->get_next = &revwalk_next_timesort;
+		walk->enqueue = &revwalk_enqueue_timesort;
+	} else {
+		walk->get_next = &revwalk_next_unsorted;
+		walk->enqueue = &revwalk_enqueue_unsorted;
+	}
+}
+
+void git_revwalk_simplify_first_parent(git_revwalk *walk)
+{
+	walk->first_parent = 1;
+}
+
+int git_revwalk_next(git_oid *oid, git_revwalk *walk)
+{
+	int error;
+	git_commit_list_node *next;
+
+	assert(walk && oid);
+
+	if (!walk->walking) {
+		if ((error = prepare_walk(walk)) < 0)
+			return error;
+	}
+
+	error = walk->get_next(&next, walk);
+
+	if (error == GIT_ITEROVER) {
+		git_revwalk_reset(walk);
+		giterr_clear();
+		return GIT_ITEROVER;
+	}
+
+	if (!error)
+		git_oid_cpy(oid, &next->oid);
+
+	return error;
+}
+
+void git_revwalk_reset(git_revwalk *walk)
+{
+	git_commit_list_node *commit;
+
+	assert(walk);
+
+	git_oidmap_foreach_value(walk->commits, commit, {
+		commit->seen = 0;
+		commit->in_degree = 0;
+		commit->topo_delay = 0;
+		commit->uninteresting = 0;
+		commit->added = 0;
+		commit->flags = 0;
+		});
+
+	git_pqueue_clear(&walk->iterator_time);
+	git_commit_list_free(&walk->iterator_topo);
+	git_commit_list_free(&walk->iterator_rand);
+	git_commit_list_free(&walk->iterator_reverse);
+	git_commit_list_free(&walk->user_input);
+	walk->first_parent = 0;
+	walk->walking = 0;
+	walk->did_push = walk->did_hide = 0;
+}
+
+int git_revwalk_add_hide_cb(
+	git_revwalk *walk,
+	git_revwalk_hide_cb hide_cb,
+	void *payload)
+{
+	assert(walk);
+
+	if (walk->walking)
+		git_revwalk_reset(walk);
+
+	if (walk->hide_cb) {
+		/* There is already a callback added */
+		giterr_set(GITERR_INVALID, "there is already a callback added to hide commits in revwalk");
+		return -1;
+	}
+
+	walk->hide_cb = hide_cb;
+	walk->hide_cb_payload = payload;
+
+	return 0;
+}
+

vendor/libgit2-sys/libgit2/src/revwalk.h

diff --git a/vendor/libgit2-sys/libgit2/src/revwalk.h b/vendor/libgit2-sys/libgit2/src/revwalk.h
new file mode 100644
index 0000000..578328b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/revwalk.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_revwalk_h__
+#define INCLUDE_revwalk_h__
+
+#include "common.h"
+
+#include "git2/revwalk.h"
+#include "oidmap.h"
+#include "commit_list.h"
+#include "pqueue.h"
+#include "pool.h"
+#include "vector.h"
+
+#include "oidmap.h"
+
+struct git_revwalk {
+	git_repository *repo;
+	git_odb *odb;
+
+	git_oidmap *commits;
+	git_pool commit_pool;
+
+	git_commit_list *iterator_topo;
+	git_commit_list *iterator_rand;
+	git_commit_list *iterator_reverse;
+	git_pqueue iterator_time;
+
+	int (*get_next)(git_commit_list_node **, git_revwalk *);
+	int (*enqueue)(git_revwalk *, git_commit_list_node *);
+
+	unsigned walking:1,
+		first_parent: 1,
+		did_hide: 1,
+		did_push: 1;
+	unsigned int sorting;
+
+	/* the pushes and hides */
+	git_commit_list *user_input;
+
+	/* hide callback */
+	git_revwalk_hide_cb hide_cb;
+	void *hide_cb_payload;
+};
+
+git_commit_list_node *git_revwalk__commit_lookup(git_revwalk *walk, const git_oid *oid);
+
+#endif

vendor/libgit2-sys/libgit2/src/settings.c

diff --git a/vendor/libgit2-sys/libgit2/src/settings.c b/vendor/libgit2-sys/libgit2/src/settings.c
new file mode 100644
index 0000000..f6bc5b2
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/settings.c
@@ -0,0 +1,272 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#ifdef GIT_OPENSSL
+# include <openssl/err.h>
+#endif
+
+#ifdef GIT_MBEDTLS
+# include <mbedtls/error.h>
+#endif
+
+#include <git2.h>
+#include "sysdir.h"
+#include "cache.h"
+#include "global.h"
+#include "object.h"
+#include "odb.h"
+#include "refs.h"
+#include "transports/smart.h"
+#include "streams/openssl.h"
+#include "streams/mbedtls.h"
+
+void git_libgit2_version(int *major, int *minor, int *rev)
+{
+	*major = LIBGIT2_VER_MAJOR;
+	*minor = LIBGIT2_VER_MINOR;
+	*rev = LIBGIT2_VER_REVISION;
+}
+
+int git_libgit2_features(void)
+{
+	return 0
+#ifdef GIT_THREADS
+		| GIT_FEATURE_THREADS
+#endif
+#ifdef GIT_HTTPS
+		| GIT_FEATURE_HTTPS
+#endif
+#if defined(GIT_SSH)
+		| GIT_FEATURE_SSH
+#endif
+#if defined(GIT_USE_NSEC)
+		| GIT_FEATURE_NSEC
+#endif
+	;
+}
+
+/* Declarations for tuneable settings */
+extern size_t git_mwindow__window_size;
+extern size_t git_mwindow__mapped_limit;
+
+static int config_level_to_sysdir(int config_level)
+{
+	int val = -1;
+
+	switch (config_level) {
+	case GIT_CONFIG_LEVEL_SYSTEM:
+		val = GIT_SYSDIR_SYSTEM;
+		break;
+	case GIT_CONFIG_LEVEL_XDG:
+		val = GIT_SYSDIR_XDG;
+		break;
+	case GIT_CONFIG_LEVEL_GLOBAL:
+		val = GIT_SYSDIR_GLOBAL;
+		break;
+	case GIT_CONFIG_LEVEL_PROGRAMDATA:
+		val = GIT_SYSDIR_PROGRAMDATA;
+		break;
+	default:
+		giterr_set(
+			GITERR_INVALID, "invalid config path selector %d", config_level);
+	}
+
+	return val;
+}
+
+extern char *git__user_agent;
+extern char *git__ssl_ciphers;
+
+const char *git_libgit2__user_agent(void)
+{
+	return git__user_agent;
+}
+
+const char *git_libgit2__ssl_ciphers(void)
+{
+	return git__ssl_ciphers;
+}
+
+int git_libgit2_opts(int key, ...)
+{
+	int error = 0;
+	va_list ap;
+
+	va_start(ap, key);
+
+	switch (key) {
+	case GIT_OPT_SET_MWINDOW_SIZE:
+		git_mwindow__window_size = va_arg(ap, size_t);
+		break;
+
+	case GIT_OPT_GET_MWINDOW_SIZE:
+		*(va_arg(ap, size_t *)) = git_mwindow__window_size;
+		break;
+
+	case GIT_OPT_SET_MWINDOW_MAPPED_LIMIT:
+		git_mwindow__mapped_limit = va_arg(ap, size_t);
+		break;
+
+	case GIT_OPT_GET_MWINDOW_MAPPED_LIMIT:
+		*(va_arg(ap, size_t *)) = git_mwindow__mapped_limit;
+		break;
+
+	case GIT_OPT_GET_SEARCH_PATH:
+		if ((error = config_level_to_sysdir(va_arg(ap, int))) >= 0) {
+			git_buf *out = va_arg(ap, git_buf *);
+			const git_buf *tmp;
+
+			git_buf_sanitize(out);
+			if ((error = git_sysdir_get(&tmp, error)) < 0)
+				break;
+
+			error = git_buf_sets(out, tmp->ptr);
+		}
+		break;
+
+	case GIT_OPT_SET_SEARCH_PATH:
+		if ((error = config_level_to_sysdir(va_arg(ap, int))) >= 0)
+			error = git_sysdir_set(error, va_arg(ap, const char *));
+		break;
+
+	case GIT_OPT_SET_CACHE_OBJECT_LIMIT:
+		{
+			git_otype type = (git_otype)va_arg(ap, int);
+			size_t size = va_arg(ap, size_t);
+			error = git_cache_set_max_object_size(type, size);
+			break;
+		}
+
+	case GIT_OPT_SET_CACHE_MAX_SIZE:
+		git_cache__max_storage = va_arg(ap, ssize_t);
+		break;
+
+	case GIT_OPT_ENABLE_CACHING:
+		git_cache__enabled = (va_arg(ap, int) != 0);
+		break;
+
+	case GIT_OPT_GET_CACHED_MEMORY:
+		*(va_arg(ap, ssize_t *)) = git_cache__current_storage.val;
+		*(va_arg(ap, ssize_t *)) = git_cache__max_storage;
+		break;
+
+	case GIT_OPT_GET_TEMPLATE_PATH:
+		{
+			git_buf *out = va_arg(ap, git_buf *);
+			const git_buf *tmp;
+
+			git_buf_sanitize(out);
+			if ((error = git_sysdir_get(&tmp, GIT_SYSDIR_TEMPLATE)) < 0)
+				break;
+
+			error = git_buf_sets(out, tmp->ptr);
+		}
+		break;
+
+	case GIT_OPT_SET_TEMPLATE_PATH:
+		error = git_sysdir_set(GIT_SYSDIR_TEMPLATE, va_arg(ap, const char *));
+		break;
+
+	case GIT_OPT_SET_SSL_CERT_LOCATIONS:
+#ifdef GIT_OPENSSL
+		{
+			const char *file = va_arg(ap, const char *);
+			const char *path = va_arg(ap, const char *);
+			error = git_openssl__set_cert_location(file, path);
+		}
+#elif defined(GIT_MBEDTLS)
+		{
+			const char *file = va_arg(ap, const char *);
+			const char *path = va_arg(ap, const char *);
+			if (file)
+				error = git_mbedtls__set_cert_location(file, 0);
+			if (error && path)
+				error = git_mbedtls__set_cert_location(path, 1);
+		}
+#else
+		giterr_set(GITERR_SSL, "TLS backend doesn't support certificate locations");
+		error = -1;
+#endif
+		break;
+	case GIT_OPT_SET_USER_AGENT:
+		git__free(git__user_agent);
+		git__user_agent = git__strdup(va_arg(ap, const char *));
+		if (!git__user_agent) {
+			giterr_set_oom();
+			error = -1;
+		}
+
+		break;
+
+	case GIT_OPT_ENABLE_STRICT_OBJECT_CREATION:
+		git_object__strict_input_validation = (va_arg(ap, int) != 0);
+		break;
+
+	case GIT_OPT_ENABLE_STRICT_SYMBOLIC_REF_CREATION:
+		git_reference__enable_symbolic_ref_target_validation = (va_arg(ap, int) != 0);
+		break;
+
+	case GIT_OPT_SET_SSL_CIPHERS:
+#if (GIT_OPENSSL || GIT_MBEDTLS)
+		{
+			git__free(git__ssl_ciphers);
+			git__ssl_ciphers = git__strdup(va_arg(ap, const char *));
+			if (!git__ssl_ciphers) {
+				giterr_set_oom();
+				error = -1;
+			}
+		}
+#else
+		giterr_set(GITERR_SSL, "TLS backend doesn't support custom ciphers");
+		error = -1;
+#endif
+		break;
+
+	case GIT_OPT_GET_USER_AGENT:
+		{
+			git_buf *out = va_arg(ap, git_buf *);
+			git_buf_sanitize(out);
+			error = git_buf_sets(out, git__user_agent);
+		}
+		break;
+
+	case GIT_OPT_ENABLE_OFS_DELTA:
+		git_smart__ofs_delta_enabled = (va_arg(ap, int) != 0);
+		break;
+
+	case GIT_OPT_ENABLE_FSYNC_GITDIR:
+		git_repository__fsync_gitdir = (va_arg(ap, int) != 0);
+		break;
+
+	case GIT_OPT_GET_WINDOWS_SHAREMODE:
+#ifdef GIT_WIN32
+		*(va_arg(ap, unsigned long *)) = git_win32__createfile_sharemode;
+#endif
+		break;
+
+	case GIT_OPT_SET_WINDOWS_SHAREMODE:
+#ifdef GIT_WIN32
+		git_win32__createfile_sharemode = va_arg(ap, unsigned long);
+#endif
+		break;
+
+	case GIT_OPT_ENABLE_STRICT_HASH_VERIFICATION:
+		git_odb__strict_hash_verification = (va_arg(ap, int) != 0);
+		break;
+
+	default:
+		giterr_set(GITERR_INVALID, "invalid option key");
+		error = -1;
+	}
+
+	va_end(ap);
+
+	return error;
+}
+

vendor/libgit2-sys/libgit2/src/sha1_lookup.c

diff --git a/vendor/libgit2-sys/libgit2/src/sha1_lookup.c b/vendor/libgit2-sys/libgit2/src/sha1_lookup.c
new file mode 100644
index 0000000..14fcb40
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/sha1_lookup.c
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "sha1_lookup.h"
+
+#include <stdio.h>
+
+#include "oid.h"
+
+int sha1_position(const void *table,
+			size_t stride,
+			unsigned lo, unsigned hi,
+			const unsigned char *key)
+{
+	const unsigned char *base = table;
+
+	while (lo < hi) {
+		unsigned mi = (lo + hi) / 2;
+		int cmp = git_oid__hashcmp(base + mi * stride, key);
+
+		if (!cmp)
+			return mi;
+
+		if (cmp > 0)
+			hi = mi;
+		else
+			lo = mi+1;
+	}
+
+	return -((int)lo)-1;
+}

vendor/libgit2-sys/libgit2/src/sha1_lookup.h

diff --git a/vendor/libgit2-sys/libgit2/src/sha1_lookup.h b/vendor/libgit2-sys/libgit2/src/sha1_lookup.h
new file mode 100644
index 0000000..841ea5b22
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/sha1_lookup.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sha1_lookup_h__
+#define INCLUDE_sha1_lookup_h__
+
+#include "common.h"
+
+#include <stdlib.h>
+
+int sha1_position(const void *table,
+			size_t stride,
+			unsigned lo, unsigned hi,
+			const unsigned char *key);
+
+#endif

vendor/libgit2-sys/libgit2/src/signature.c

diff --git a/vendor/libgit2-sys/libgit2/src/signature.c b/vendor/libgit2-sys/libgit2/src/signature.c
new file mode 100644
index 0000000..cd68523
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/signature.c
@@ -0,0 +1,330 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "signature.h"
+
+#include "repository.h"
+#include "git2/common.h"
+#include "posix.h"
+
+void git_signature_free(git_signature *sig)
+{
+	if (sig == NULL)
+		return;
+
+	git__free(sig->name);
+	sig->name = NULL;
+	git__free(sig->email);
+	sig->email = NULL;
+	git__free(sig);
+}
+
+static int signature_error(const char *msg)
+{
+	giterr_set(GITERR_INVALID, "failed to parse signature - %s", msg);
+	return -1;
+}
+
+static bool contains_angle_brackets(const char *input)
+{
+	return strchr(input, '<') != NULL || strchr(input, '>') != NULL;
+}
+
+static bool is_crud(unsigned char c)
+{
+	return  c <= 32  ||
+		c == '.' ||
+		c == ',' ||
+		c == ':' ||
+		c == ';' ||
+		c == '<' ||
+		c == '>' ||
+		c == '"' ||
+		c == '\\' ||
+		c == '\'';
+}
+
+static char *extract_trimmed(const char *ptr, size_t len)
+{
+	while (len && is_crud((unsigned char)ptr[0])) {
+		ptr++; len--;
+	}
+
+	while (len && is_crud((unsigned char)ptr[len - 1])) {
+		len--;
+	}
+
+	return git__substrdup(ptr, len);
+}
+
+int git_signature_new(git_signature **sig_out, const char *name, const char *email, git_time_t time, int offset)
+{
+	git_signature *p = NULL;
+
+	assert(name && email);
+
+	*sig_out = NULL;
+
+	if (contains_angle_brackets(name) ||
+		contains_angle_brackets(email)) {
+		return signature_error(
+			"Neither `name` nor `email` should contain angle brackets chars.");
+	}
+
+	p = git__calloc(1, sizeof(git_signature));
+	GITERR_CHECK_ALLOC(p);
+
+	p->name = extract_trimmed(name, strlen(name));
+	GITERR_CHECK_ALLOC(p->name);
+	p->email = extract_trimmed(email, strlen(email));
+	GITERR_CHECK_ALLOC(p->email);
+
+	if (p->name[0] == '\0' || p->email[0] == '\0') {
+		git_signature_free(p);
+		return signature_error("Signature cannot have an empty name or email");
+	}
+
+	p->when.time = time;
+	p->when.offset = offset;
+	p->when.sign = (offset < 0) ? '-' : '+';
+
+	*sig_out = p;
+	return 0;
+}
+
+int git_signature_dup(git_signature **dest, const git_signature *source)
+{
+	git_signature *signature;
+
+	if (source == NULL)
+		return 0;
+
+	signature = git__calloc(1, sizeof(git_signature));
+	GITERR_CHECK_ALLOC(signature);
+
+	signature->name = git__strdup(source->name);
+	GITERR_CHECK_ALLOC(signature->name);
+
+	signature->email = git__strdup(source->email);
+	GITERR_CHECK_ALLOC(signature->email);
+
+	signature->when.time = source->when.time;
+	signature->when.offset = source->when.offset;
+	signature->when.sign = source->when.sign;
+
+	*dest = signature;
+
+	return 0;
+}
+
+int git_signature__pdup(git_signature **dest, const git_signature *source, git_pool *pool)
+{
+	git_signature *signature;
+
+	if (source == NULL)
+		return 0;
+
+	signature = git_pool_mallocz(pool, sizeof(git_signature));
+	GITERR_CHECK_ALLOC(signature);
+
+	signature->name = git_pool_strdup(pool, source->name);
+	GITERR_CHECK_ALLOC(signature->name);
+
+	signature->email = git_pool_strdup(pool, source->email);
+	GITERR_CHECK_ALLOC(signature->email);
+
+	signature->when.time = source->when.time;
+	signature->when.offset = source->when.offset;
+	signature->when.sign = source->when.sign;
+
+	*dest = signature;
+
+	return 0;
+}
+
+int git_signature_now(git_signature **sig_out, const char *name, const char *email)
+{
+	time_t now;
+	time_t offset;
+	struct tm *utc_tm;
+	git_signature *sig;
+	struct tm _utc;
+
+	*sig_out = NULL;
+
+	/*
+	 * Get the current time as seconds since the epoch and
+	 * transform that into a tm struct containing the time at
+	 * UTC. Give that to mktime which considers it a local time
+	 * (tm_isdst = -1 asks it to take DST into account) and gives
+	 * us that time as seconds since the epoch. The difference
+	 * between its return value and 'now' is our offset to UTC.
+	 */
+	time(&now);
+	utc_tm = p_gmtime_r(&now, &_utc);
+	utc_tm->tm_isdst = -1;
+	offset = (time_t)difftime(now, mktime(utc_tm));
+	offset /= 60;
+
+	if (git_signature_new(&sig, name, email, now, (int)offset) < 0)
+		return -1;
+
+	*sig_out = sig;
+
+	return 0;
+}
+
+int git_signature_default(git_signature **out, git_repository *repo)
+{
+	int error;
+	git_config *cfg;
+	const char *user_name, *user_email;
+
+	if ((error = git_repository_config_snapshot(&cfg, repo)) < 0)
+		return error;
+
+	if (!(error = git_config_get_string(&user_name, cfg, "user.name")) &&
+		!(error = git_config_get_string(&user_email, cfg, "user.email")))
+		error = git_signature_now(out, user_name, user_email);
+
+	git_config_free(cfg);
+	return error;
+}
+
+int git_signature__parse(git_signature *sig, const char **buffer_out,
+		const char *buffer_end, const char *header, char ender)
+{
+	const char *buffer = *buffer_out;
+	const char *email_start, *email_end;
+
+	memset(sig, 0, sizeof(git_signature));
+
+	if (ender &&
+		(buffer_end = memchr(buffer, ender, buffer_end - buffer)) == NULL)
+		return signature_error("no newline given");
+
+	if (header) {
+		const size_t header_len = strlen(header);
+
+		if (buffer + header_len >= buffer_end || memcmp(buffer, header, header_len) != 0)
+			return signature_error("expected prefix doesn't match actual");
+
+		buffer += header_len;
+	}
+
+	email_start = git__memrchr(buffer, '<', buffer_end - buffer);
+	email_end = git__memrchr(buffer, '>', buffer_end - buffer);
+
+	if (!email_start || !email_end || email_end <= email_start)
+		return signature_error("malformed e-mail");
+
+	email_start += 1;
+	sig->name = extract_trimmed(buffer, email_start - buffer - 1);
+	sig->email = extract_trimmed(email_start, email_end - email_start);
+
+	/* Do we even have a time at the end of the signature? */
+	if (email_end + 2 < buffer_end) {
+		const char *time_start = email_end + 2;
+		const char *time_end;
+
+		if (git__strtol64(&sig->when.time, time_start, &time_end, 10) < 0) {
+			git__free(sig->name);
+			git__free(sig->email);
+			sig->name = sig->email = NULL;
+			return signature_error("invalid Unix timestamp");
+		}
+
+		/* do we have a timezone? */
+		if (time_end + 1 < buffer_end) {
+			int offset, hours, mins;
+			const char *tz_start, *tz_end;
+
+			tz_start = time_end + 1;
+
+			if ((tz_start[0] != '-' && tz_start[0] != '+') ||
+				git__strtol32(&offset, tz_start + 1, &tz_end, 10) < 0) {
+				//malformed timezone, just assume it's zero
+				offset = 0;
+			}
+
+			hours = offset / 100;
+			mins = offset % 100;
+
+			/*
+			 * only store timezone if it's not overflowing;
+			 * see http://www.worldtimezone.com/faq.html
+			 */
+			if (hours <= 14 && mins <= 59) {
+				sig->when.offset = (hours * 60) + mins;
+				sig->when.sign = tz_start[0];
+				if (tz_start[0] == '-')
+					sig->when.offset = -sig->when.offset;
+			}
+		}
+	}
+
+	*buffer_out = buffer_end + 1;
+	return 0;
+}
+
+int git_signature_from_buffer(git_signature **out, const char *buf)
+{
+	git_signature *sig;
+	const char *buf_end;
+	int error;
+
+	assert(out && buf);
+
+	*out = NULL;
+
+	sig = git__calloc(1, sizeof(git_signature));
+	GITERR_CHECK_ALLOC(sig);
+
+	buf_end = buf + strlen(buf);
+	error = git_signature__parse(sig, &buf, buf_end, NULL, '\0');
+
+	if (error)
+		git__free(sig);
+	else
+		*out = sig;
+
+	return error;
+}
+
+void git_signature__writebuf(git_buf *buf, const char *header, const git_signature *sig)
+{
+	int offset, hours, mins;
+	char sign;
+
+	assert(buf && sig);
+
+	offset = sig->when.offset;
+	sign = (sig->when.offset < 0 || sig->when.sign == '-') ? '-' : '+';
+
+	if (offset < 0)
+		offset = -offset;
+
+	hours = offset / 60;
+	mins = offset % 60;
+
+	git_buf_printf(buf, "%s%s <%s> %u %c%02d%02d\n",
+			header ? header : "", sig->name, sig->email,
+			(unsigned)sig->when.time, sign, hours, mins);
+}
+
+bool git_signature__equal(const git_signature *one, const git_signature *two)
+{
+	assert(one && two);
+
+	return
+		git__strcmp(one->name, two->name) == 0 &&
+		git__strcmp(one->email, two->email) == 0 &&
+		one->when.time == two->when.time &&
+		one->when.offset == two->when.offset &&
+		one->when.sign == two->when.sign;
+}
+

vendor/libgit2-sys/libgit2/src/signature.h

diff --git a/vendor/libgit2-sys/libgit2/src/signature.h b/vendor/libgit2-sys/libgit2/src/signature.h
new file mode 100644
index 0000000..40d7c54
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/signature.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_signature_h__
+#define INCLUDE_signature_h__
+
+#include "common.h"
+
+#include "git2/common.h"
+#include "git2/signature.h"
+#include "repository.h"
+#include <time.h>
+
+int git_signature__parse(git_signature *sig, const char **buffer_out, const char *buffer_end, const char *header, char ender);
+void git_signature__writebuf(git_buf *buf, const char *header, const git_signature *sig);
+bool git_signature__equal(const git_signature *one, const git_signature *two);
+
+int git_signature__pdup(git_signature **dest, const git_signature *source, git_pool *pool);
+
+#endif

vendor/libgit2-sys/libgit2/src/sortedcache.c

diff --git a/vendor/libgit2-sys/libgit2/src/sortedcache.c b/vendor/libgit2-sys/libgit2/src/sortedcache.c
new file mode 100644
index 0000000..76672d9
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/sortedcache.c
@@ -0,0 +1,395 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "sortedcache.h"
+
+int git_sortedcache_new(
+	git_sortedcache **out,
+	size_t item_path_offset,
+	git_sortedcache_free_item_fn free_item,
+	void *free_item_payload,
+	git_vector_cmp item_cmp,
+	const char *path)
+{
+	git_sortedcache *sc;
+	size_t pathlen, alloclen;
+
+	pathlen = path ? strlen(path) : 0;
+
+	GITERR_CHECK_ALLOC_ADD(&alloclen, sizeof(git_sortedcache), pathlen);
+	GITERR_CHECK_ALLOC_ADD(&alloclen, alloclen, 1);
+	sc = git__calloc(1, alloclen);
+	GITERR_CHECK_ALLOC(sc);
+
+	git_pool_init(&sc->pool, 1);
+
+	if (git_vector_init(&sc->items, 4, item_cmp) < 0 ||
+		git_strmap_alloc(&sc->map) < 0)
+		goto fail;
+
+	if (git_rwlock_init(&sc->lock)) {
+		giterr_set(GITERR_OS, "failed to initialize lock");
+		goto fail;
+	}
+
+	sc->item_path_offset  = item_path_offset;
+	sc->free_item         = free_item;
+	sc->free_item_payload = free_item_payload;
+	GIT_REFCOUNT_INC(sc);
+	if (pathlen)
+		memcpy(sc->path, path, pathlen);
+
+	*out = sc;
+	return 0;
+
+fail:
+	git_strmap_free(sc->map);
+	git_vector_free(&sc->items);
+	git_pool_clear(&sc->pool);
+	git__free(sc);
+	return -1;
+}
+
+void git_sortedcache_incref(git_sortedcache *sc)
+{
+	GIT_REFCOUNT_INC(sc);
+}
+
+const char *git_sortedcache_path(git_sortedcache *sc)
+{
+	return sc->path;
+}
+
+static void sortedcache_clear(git_sortedcache *sc)
+{
+	git_strmap_clear(sc->map);
+
+	if (sc->free_item) {
+		size_t i;
+		void *item;
+
+		git_vector_foreach(&sc->items, i, item) {
+			sc->free_item(sc->free_item_payload, item);
+		}
+	}
+
+	git_vector_clear(&sc->items);
+
+	git_pool_clear(&sc->pool);
+}
+
+static void sortedcache_free(git_sortedcache *sc)
+{
+	/* acquire write lock to make sure everyone else is done */
+	if (git_sortedcache_wlock(sc) < 0)
+		return;
+
+	sortedcache_clear(sc);
+	git_vector_free(&sc->items);
+	git_strmap_free(sc->map);
+
+	git_sortedcache_wunlock(sc);
+
+	git_rwlock_free(&sc->lock);
+	git__free(sc);
+}
+
+void git_sortedcache_free(git_sortedcache *sc)
+{
+	if (!sc)
+		return;
+	GIT_REFCOUNT_DEC(sc, sortedcache_free);
+}
+
+static int sortedcache_copy_item(void *payload, void *tgt_item, void *src_item)
+{
+	git_sortedcache *sc = payload;
+	/* path will already have been copied by upsert */
+	memcpy(tgt_item, src_item, sc->item_path_offset);
+	return 0;
+}
+
+/* copy a sorted cache */
+int git_sortedcache_copy(
+	git_sortedcache **out,
+	git_sortedcache *src,
+	bool lock,
+	int (*copy_item)(void *payload, void *tgt_item, void *src_item),
+	void *payload)
+{
+	int error = 0;
+	git_sortedcache *tgt;
+	size_t i;
+	void *src_item, *tgt_item;
+
+	/* just use memcpy if no special copy fn is passed in */
+	if (!copy_item) {
+		copy_item = sortedcache_copy_item;
+		payload   = src;
+	}
+
+	if ((error = git_sortedcache_new(
+			&tgt, src->item_path_offset,
+			src->free_item, src->free_item_payload,
+			src->items._cmp, src->path)) < 0)
+		return error;
+
+	if (lock && git_sortedcache_rlock(src) < 0) {
+		git_sortedcache_free(tgt);
+		return -1;
+	}
+
+	git_vector_foreach(&src->items, i, src_item) {
+		char *path = ((char *)src_item) + src->item_path_offset;
+
+		if ((error = git_sortedcache_upsert(&tgt_item, tgt, path)) < 0 ||
+			(error = copy_item(payload, tgt_item, src_item)) < 0)
+			break;
+	}
+
+	if (lock)
+		git_sortedcache_runlock(src);
+	if (error)
+		git_sortedcache_free(tgt);
+
+	*out = !error ? tgt : NULL;
+
+	return error;
+}
+
+/* lock sortedcache while making modifications */
+int git_sortedcache_wlock(git_sortedcache *sc)
+{
+	GIT_UNUSED(sc); /* prevent warning when compiled w/o threads */
+
+	if (git_rwlock_wrlock(&sc->lock) < 0) {
+		giterr_set(GITERR_OS, "unable to acquire write lock on cache");
+		return -1;
+	}
+	return 0;
+}
+
+/* unlock sorted cache when done with modifications */
+void git_sortedcache_wunlock(git_sortedcache *sc)
+{
+	git_vector_sort(&sc->items);
+	git_rwlock_wrunlock(&sc->lock);
+}
+
+/* lock sortedcache for read */
+int git_sortedcache_rlock(git_sortedcache *sc)
+{
+	GIT_UNUSED(sc); /* prevent warning when compiled w/o threads */
+
+	if (git_rwlock_rdlock(&sc->lock) < 0) {
+		giterr_set(GITERR_OS, "unable to acquire read lock on cache");
+		return -1;
+	}
+	return 0;
+}
+
+/* unlock sorted cache when done reading */
+void git_sortedcache_runlock(git_sortedcache *sc)
+{
+	GIT_UNUSED(sc); /* prevent warning when compiled w/o threads */
+	git_rwlock_rdunlock(&sc->lock);
+}
+
+/* if the file has changed, lock cache and load file contents into buf;
+ * returns <0 on error, >0 if file has not changed
+ */
+int git_sortedcache_lockandload(git_sortedcache *sc, git_buf *buf)
+{
+	int error, fd;
+	struct stat st;
+
+	if ((error = git_sortedcache_wlock(sc)) < 0)
+		return error;
+
+	if ((error = git_futils_filestamp_check(&sc->stamp, sc->path)) <= 0)
+		goto unlock;
+
+	if ((fd = git_futils_open_ro(sc->path)) < 0) {
+		error = fd;
+		goto unlock;
+	}
+
+	if (p_fstat(fd, &st) < 0) {
+		giterr_set(GITERR_OS, "failed to stat file");
+		error = -1;
+		(void)p_close(fd);
+		goto unlock;
+	}
+
+	if (!git__is_sizet(st.st_size)) {
+		giterr_set(GITERR_INVALID, "unable to load file larger than size_t");
+		error = -1;
+		(void)p_close(fd);
+		goto unlock;
+	}
+
+	if (buf)
+		error = git_futils_readbuffer_fd(buf, fd, (size_t)st.st_size);
+
+	(void)p_close(fd);
+
+	if (error < 0)
+		goto unlock;
+
+	return 1; /* return 1 -> file needs reload and was successfully loaded */
+
+unlock:
+	git_sortedcache_wunlock(sc);
+	return error;
+}
+
+void git_sortedcache_updated(git_sortedcache *sc)
+{
+	/* update filestamp to latest value */
+	git_futils_filestamp_check(&sc->stamp, sc->path);
+}
+
+/* release all items in sorted cache */
+int git_sortedcache_clear(git_sortedcache *sc, bool wlock)
+{
+	if (wlock && git_sortedcache_wlock(sc) < 0)
+		return -1;
+
+	sortedcache_clear(sc);
+
+	if (wlock)
+		git_sortedcache_wunlock(sc);
+
+	return 0;
+}
+
+/* find and/or insert item, returning pointer to item data */
+int git_sortedcache_upsert(void **out, git_sortedcache *sc, const char *key)
+{
+	int error = 0;
+	khiter_t pos;
+	void *item;
+	size_t keylen, itemlen;
+	char *item_key;
+
+	pos = git_strmap_lookup_index(sc->map, key);
+	if (git_strmap_valid_index(sc->map, pos)) {
+		item = git_strmap_value_at(sc->map, pos);
+		goto done;
+	}
+
+	keylen  = strlen(key);
+	itemlen = sc->item_path_offset + keylen + 1;
+	itemlen = (itemlen + 7) & ~7;
+
+	if ((item = git_pool_mallocz(&sc->pool, (uint32_t)itemlen)) == NULL) {
+		/* don't use GITERR_CHECK_ALLOC b/c of lock */
+		error = -1;
+		goto done;
+	}
+
+	/* one strange thing is that even if the vector or hash table insert
+	 * fail, there is no way to free the pool item so we just abandon it
+	 */
+
+	item_key = ((char *)item) + sc->item_path_offset;
+	memcpy(item_key, key, keylen);
+
+	pos = git_strmap_put(sc->map, item_key, &error);
+	if (error < 0)
+		goto done;
+
+	if (!error)
+		git_strmap_set_key_at(sc->map, pos, item_key);
+	git_strmap_set_value_at(sc->map, pos, item);
+
+	error = git_vector_insert(&sc->items, item);
+	if (error < 0)
+		git_strmap_delete_at(sc->map, pos);
+
+done:
+	if (out)
+		*out = !error ? item : NULL;
+	return error;
+}
+
+/* lookup item by key */
+void *git_sortedcache_lookup(const git_sortedcache *sc, const char *key)
+{
+	khiter_t pos = git_strmap_lookup_index(sc->map, key);
+	if (git_strmap_valid_index(sc->map, pos))
+		return git_strmap_value_at(sc->map, pos);
+	return NULL;
+}
+
+/* find out how many items are in the cache */
+size_t git_sortedcache_entrycount(const git_sortedcache *sc)
+{
+	return git_vector_length(&sc->items);
+}
+
+/* lookup item by index */
+void *git_sortedcache_entry(git_sortedcache *sc, size_t pos)
+{
+	/* make sure the items are sorted so this gets the correct item */
+	if (!git_vector_is_sorted(&sc->items))
+		git_vector_sort(&sc->items);
+
+	return git_vector_get(&sc->items, pos);
+}
+
+/* helper struct so bsearch callback can know offset + key value for cmp */
+struct sortedcache_magic_key {
+	size_t offset;
+	const char *key;
+};
+
+static int sortedcache_magic_cmp(const void *key, const void *value)
+{
+	const struct sortedcache_magic_key *magic = key;
+	const char *value_key = ((const char *)value) + magic->offset;
+	return strcmp(magic->key, value_key);
+}
+
+/* lookup index of item by key */
+int git_sortedcache_lookup_index(
+	size_t *out, git_sortedcache *sc, const char *key)
+{
+	struct sortedcache_magic_key magic;
+
+	magic.offset = sc->item_path_offset;
+	magic.key    = key;
+
+	return git_vector_bsearch2(out, &sc->items, sortedcache_magic_cmp, &magic);
+}
+
+/* remove entry from cache */
+int git_sortedcache_remove(git_sortedcache *sc, size_t pos)
+{
+	char *item;
+	khiter_t mappos;
+
+	/* because of pool allocation, this can't actually remove the item,
+	 * but we can remove it from the items vector and the hash table.
+	 */
+
+	if ((item = git_vector_get(&sc->items, pos)) == NULL) {
+		giterr_set(GITERR_INVALID, "removing item out of range");
+		return GIT_ENOTFOUND;
+	}
+
+	(void)git_vector_remove(&sc->items, pos);
+
+	mappos = git_strmap_lookup_index(sc->map, item + sc->item_path_offset);
+	git_strmap_delete_at(sc->map, mappos);
+
+	if (sc->free_item)
+		sc->free_item(sc->free_item_payload, item);
+
+	return 0;
+}
+

vendor/libgit2-sys/libgit2/src/sortedcache.h

diff --git a/vendor/libgit2-sys/libgit2/src/sortedcache.h b/vendor/libgit2-sys/libgit2/src/sortedcache.h
new file mode 100644
index 0000000..a53ff48
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/sortedcache.h
@@ -0,0 +1,180 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sorted_cache_h__
+#define INCLUDE_sorted_cache_h__
+
+#include "common.h"
+
+#include "util.h"
+#include "fileops.h"
+#include "vector.h"
+#include "thread-utils.h"
+#include "pool.h"
+#include "strmap.h"
+
+#include <stddef.h>
+
+/*
+ * The purpose of this data structure is to cache the parsed contents of a
+ * file (a.k.a. the backing file) where each item in the file can be
+ * identified by a key string and you want to both look them up by name
+ * and traverse them in sorted order.  Each item is assumed to itself end
+ * in a GIT_FLEX_ARRAY.
+ */
+
+typedef void (*git_sortedcache_free_item_fn)(void *payload, void *item);
+
+typedef struct {
+	git_refcount rc;
+	git_rwlock   lock;
+	size_t       item_path_offset;
+	git_sortedcache_free_item_fn free_item;
+	void         *free_item_payload;
+	git_pool     pool;
+	git_vector   items;
+	git_strmap   *map;
+	git_futils_filestamp stamp;
+	char         path[GIT_FLEX_ARRAY];
+} git_sortedcache;
+
+/* Create a new sortedcache
+ *
+ * Even though every sortedcache stores items with a GIT_FLEX_ARRAY at
+ * the end containing their key string, you have to provide the item_cmp
+ * sorting function because the sorting function doesn't get a payload
+ * and therefore can't know the offset to the item key string. :-(
+ *
+ * @param out The allocated git_sortedcache
+ * @param item_path_offset Offset to the GIT_FLEX_ARRAY item key in the
+ *        struct - use offsetof(struct mine, key-field) to get this
+ * @param free_item Optional callback to free each item
+ * @param free_item_payload Optional payload passed to free_item callback
+ * @param item_cmp Compare the keys of two items
+ * @param path The path to the backing store file for this cache; this
+ *        may be NULL.  The cache makes it easy to load this and check
+ *        if it has been modified since the last load and/or write.
+ */
+int git_sortedcache_new(
+	git_sortedcache **out,
+	size_t item_path_offset, /* use offsetof(struct, path-field) macro */
+	git_sortedcache_free_item_fn free_item,
+	void *free_item_payload,
+	git_vector_cmp item_cmp,
+	const char *path);
+
+/* Copy a sorted cache
+ *
+ * - `copy_item` can be NULL to just use memcpy
+ * - if `lock`, grabs read lock on `src` during copy and releases after
+ */
+int git_sortedcache_copy(
+	git_sortedcache **out,
+	git_sortedcache *src,
+	bool lock,
+	int (*copy_item)(void *payload, void *tgt_item, void *src_item),
+	void *payload);
+
+/* Free sorted cache (first calling `free_item` callbacks)
+ *
+ * Don't call on a locked collection - it may acquire a write lock
+ */
+void git_sortedcache_free(git_sortedcache *sc);
+
+/* Increment reference count - balance with call to free */
+void git_sortedcache_incref(git_sortedcache *sc);
+
+/* Get the pathname associated with this cache at creation time */
+const char *git_sortedcache_path(git_sortedcache *sc);
+
+/*
+ * CACHE WRITE FUNCTIONS
+ *
+ * The following functions require you to have a writer lock to make the
+ * modification.  Some of the functions take a `wlock` parameter and
+ * will optionally lock and unlock for you if that is passed as true.
+ *
+ */
+
+/* Lock sortedcache for write */
+int git_sortedcache_wlock(git_sortedcache *sc);
+
+/* Unlock sorted cache when done with write */
+void git_sortedcache_wunlock(git_sortedcache *sc);
+
+/* Lock cache and load backing file into a buffer.
+ *
+ * This grabs a write lock on the cache then looks at the modification
+ * time and size of the file on disk.
+ *
+ * If the file appears to have changed, this loads the file contents into
+ * the buffer and returns a positive value leaving the cache locked - the
+ * caller should parse the file content, update the cache as needed, then
+ * release the lock.  NOTE: In this case, the caller MUST unlock the cache.
+ *
+ * If the file appears to be unchanged, then this automatically releases
+ * the lock on the cache, clears the buffer, and returns 0.
+ *
+ * @return 0 if up-to-date, 1 if out-of-date, <0 on error
+ */
+int git_sortedcache_lockandload(git_sortedcache *sc, git_buf *buf);
+
+/* Refresh file timestamp after write completes
+ * You should already be holding the write lock when you call this.
+ */
+void git_sortedcache_updated(git_sortedcache *sc);
+
+/* Release all items in sorted cache
+ *
+ * If `wlock` is true, grabs write lock and releases when done, otherwise
+ * you should already be holding a write lock when you call this.
+ */
+int git_sortedcache_clear(git_sortedcache *sc, bool wlock);
+
+/* Find and/or insert item, returning pointer to item data.
+ * You should already be holding the write lock when you call this.
+ */
+int git_sortedcache_upsert(
+	void **out, git_sortedcache *sc, const char *key);
+
+/* Removes entry at pos from cache
+ * You should already be holding the write lock when you call this.
+ */
+int git_sortedcache_remove(git_sortedcache *sc, size_t pos);
+
+/*
+ * CACHE READ FUNCTIONS
+ *
+ * The following functions access items in the cache.  To prevent the
+ * results from being invalidated before they can be used, you should be
+ * holding either a read lock or a write lock when using these functions.
+ *
+ */
+
+/* Lock sortedcache for read */
+int git_sortedcache_rlock(git_sortedcache *sc);
+
+/* Unlock sorted cache when done with read */
+void git_sortedcache_runlock(git_sortedcache *sc);
+
+/* Lookup item by key - returns NULL if not found */
+void *git_sortedcache_lookup(const git_sortedcache *sc, const char *key);
+
+/* Get how many items are in the cache
+ *
+ * You can call this function without holding a lock, but be aware
+ * that it may change before you use it.
+ */
+size_t git_sortedcache_entrycount(const git_sortedcache *sc);
+
+/* Lookup item by index - returns NULL if out of range */
+void *git_sortedcache_entry(git_sortedcache *sc, size_t pos);
+
+/* Lookup index of item by key - returns GIT_ENOTFOUND if not found */
+int git_sortedcache_lookup_index(
+	size_t *out, git_sortedcache *sc, const char *key);
+
+#endif

vendor/libgit2-sys/libgit2/src/stash.c

diff --git a/vendor/libgit2-sys/libgit2/src/stash.c b/vendor/libgit2-sys/libgit2/src/stash.c
new file mode 100644
index 0000000..4b7e92a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/stash.c
@@ -0,0 +1,1078 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "repository.h"
+#include "commit.h"
+#include "message.h"
+#include "tree.h"
+#include "reflog.h"
+#include "git2/diff.h"
+#include "git2/stash.h"
+#include "git2/status.h"
+#include "git2/checkout.h"
+#include "git2/index.h"
+#include "git2/transaction.h"
+#include "git2/merge.h"
+#include "index.h"
+#include "signature.h"
+#include "iterator.h"
+#include "merge.h"
+#include "diff.h"
+#include "diff_generate.h"
+
+static int create_error(int error, const char *msg)
+{
+	giterr_set(GITERR_STASH, "cannot stash changes - %s", msg);
+	return error;
+}
+
+static int retrieve_head(git_reference **out, git_repository *repo)
+{
+	int error = git_repository_head(out, repo);
+
+	if (error == GIT_EUNBORNBRANCH)
+		return create_error(error, "you do not have the initial commit yet.");
+
+	return error;
+}
+
+static int append_abbreviated_oid(git_buf *out, const git_oid *b_commit)
+{
+	char *formatted_oid;
+
+	formatted_oid = git_oid_allocfmt(b_commit);
+	GITERR_CHECK_ALLOC(formatted_oid);
+
+	git_buf_put(out, formatted_oid, 7);
+	git__free(formatted_oid);
+
+	return git_buf_oom(out) ? -1 : 0;
+}
+
+static int append_commit_description(git_buf *out, git_commit* commit)
+{
+	const char *summary = git_commit_summary(commit);
+	GITERR_CHECK_ALLOC(summary);
+
+	if (append_abbreviated_oid(out, git_commit_id(commit)) < 0)
+		return -1;
+
+	git_buf_putc(out, ' ');
+	git_buf_puts(out, summary);
+	git_buf_putc(out, '\n');
+
+	return git_buf_oom(out) ? -1 : 0;
+}
+
+static int retrieve_base_commit_and_message(
+	git_commit **b_commit,
+	git_buf *stash_message,
+	git_repository *repo)
+{
+	git_reference *head = NULL;
+	int error;
+
+	if ((error = retrieve_head(&head, repo)) < 0)
+		return error;
+
+	if (strcmp("HEAD", git_reference_name(head)) == 0)
+		error = git_buf_puts(stash_message, "(no branch): ");
+	else
+		error = git_buf_printf(
+			stash_message,
+			"%s: ",
+			git_reference_name(head) + strlen(GIT_REFS_HEADS_DIR));
+	if (error < 0)
+		goto cleanup;
+
+	if ((error = git_commit_lookup(
+			 b_commit, repo, git_reference_target(head))) < 0)
+		goto cleanup;
+
+	if ((error = append_commit_description(stash_message, *b_commit)) < 0)
+		goto cleanup;
+
+cleanup:
+	git_reference_free(head);
+	return error;
+}
+
+static int build_tree_from_index(git_tree **out, git_index *index)
+{
+	int error;
+	git_oid i_tree_oid;
+
+	if ((error = git_index_write_tree(&i_tree_oid, index)) < 0)
+		return error;
+
+	return git_tree_lookup(out, git_index_owner(index), &i_tree_oid);
+}
+
+static int commit_index(
+	git_commit **i_commit,
+	git_index *index,
+	const git_signature *stasher,
+	const char *message,
+	const git_commit *parent)
+{
+	git_tree *i_tree = NULL;
+	git_oid i_commit_oid;
+	git_buf msg = GIT_BUF_INIT;
+	int error;
+
+	if ((error = build_tree_from_index(&i_tree, index)) < 0)
+		goto cleanup;
+
+	if ((error = git_buf_printf(&msg, "index on %s\n", message)) < 0)
+		goto cleanup;
+
+	if ((error = git_commit_create(
+		&i_commit_oid,
+		git_index_owner(index),
+		NULL,
+		stasher,
+		stasher,
+		NULL,
+		git_buf_cstr(&msg),
+		i_tree,
+		1,
+		&parent)) < 0)
+		goto cleanup;
+
+	error = git_commit_lookup(i_commit, git_index_owner(index), &i_commit_oid);
+
+cleanup:
+	git_tree_free(i_tree);
+	git_buf_free(&msg);
+	return error;
+}
+
+struct stash_update_rules {
+	bool include_changed;
+	bool include_untracked;
+	bool include_ignored;
+};
+
+static int stash_update_index_from_diff(
+	git_index *index,
+	const git_diff *diff,
+	struct stash_update_rules *data)
+{
+	int error = 0;
+	size_t d, max_d = git_diff_num_deltas(diff);
+
+	for (d = 0; !error && d < max_d; ++d) {
+		const char *add_path = NULL;
+		const git_diff_delta *delta = git_diff_get_delta(diff, d);
+
+		switch (delta->status) {
+		case GIT_DELTA_IGNORED:
+			if (data->include_ignored)
+				add_path = delta->new_file.path;
+			break;
+
+		case GIT_DELTA_UNTRACKED:
+			if (data->include_untracked &&
+				delta->new_file.mode != GIT_FILEMODE_TREE)
+				add_path = delta->new_file.path;
+			break;
+
+		case GIT_DELTA_ADDED:
+		case GIT_DELTA_MODIFIED:
+			if (data->include_changed)
+				add_path = delta->new_file.path;
+			break;
+
+		case GIT_DELTA_DELETED:
+			if (data->include_changed &&
+				!git_index_find(NULL, index, delta->old_file.path))
+				error = git_index_remove(index, delta->old_file.path, 0);
+			break;
+
+		default:
+			/* Unimplemented */
+			giterr_set(
+				GITERR_INVALID,
+				"cannot update index. Unimplemented status (%d)",
+				delta->status);
+			return -1;
+		}
+
+		if (add_path != NULL)
+			error = git_index_add_bypath(index, add_path);
+	}
+
+	return error;
+}
+
+static int build_untracked_tree(
+	git_tree **tree_out,
+	git_index *index,
+	git_commit *i_commit,
+	uint32_t flags)
+{
+	git_tree *i_tree = NULL;
+	git_diff *diff = NULL;
+	git_diff_options opts = GIT_DIFF_OPTIONS_INIT;
+	struct stash_update_rules data = {0};
+	int error;
+
+	git_index_clear(index);
+
+	if (flags & GIT_STASH_INCLUDE_UNTRACKED) {
+		opts.flags |= GIT_DIFF_INCLUDE_UNTRACKED |
+			GIT_DIFF_RECURSE_UNTRACKED_DIRS;
+		data.include_untracked = true;
+	}
+
+	if (flags & GIT_STASH_INCLUDE_IGNORED) {
+		opts.flags |= GIT_DIFF_INCLUDE_IGNORED |
+			GIT_DIFF_RECURSE_IGNORED_DIRS;
+		data.include_ignored = true;
+	}
+
+	if ((error = git_commit_tree(&i_tree, i_commit)) < 0)
+		goto cleanup;
+
+	if ((error = git_diff_tree_to_workdir(
+			&diff, git_index_owner(index), i_tree, &opts)) < 0)
+		goto cleanup;
+
+	if ((error = stash_update_index_from_diff(index, diff, &data)) < 0)
+		goto cleanup;
+
+	error = build_tree_from_index(tree_out, index);
+
+cleanup:
+	git_diff_free(diff);
+	git_tree_free(i_tree);
+	return error;
+}
+
+static int commit_untracked(
+	git_commit **u_commit,
+	git_index *index,
+	const git_signature *stasher,
+	const char *message,
+	git_commit *i_commit,
+	uint32_t flags)
+{
+	git_tree *u_tree = NULL;
+	git_oid u_commit_oid;
+	git_buf msg = GIT_BUF_INIT;
+	int error;
+
+	if ((error = build_untracked_tree(&u_tree, index, i_commit, flags)) < 0)
+		goto cleanup;
+
+	if ((error = git_buf_printf(&msg, "untracked files on %s\n", message)) < 0)
+		goto cleanup;
+
+	if ((error = git_commit_create(
+		&u_commit_oid,
+		git_index_owner(index),
+		NULL,
+		stasher,
+		stasher,
+		NULL,
+		git_buf_cstr(&msg),
+		u_tree,
+		0,
+		NULL)) < 0)
+		goto cleanup;
+
+	error = git_commit_lookup(u_commit, git_index_owner(index), &u_commit_oid);
+
+cleanup:
+	git_tree_free(u_tree);
+	git_buf_free(&msg);
+	return error;
+}
+
+static git_diff_delta *stash_delta_merge(
+	const git_diff_delta *a,
+	const git_diff_delta *b,
+	git_pool *pool)
+{
+	/* Special case for stash: if a file is deleted in the index, but exists
+	 * in the working tree, we need to stash the workdir copy for the workdir.
+	 */
+	if (a->status == GIT_DELTA_DELETED && b->status == GIT_DELTA_UNTRACKED) {
+		git_diff_delta *dup = git_diff__delta_dup(b, pool);
+
+		if (dup)
+			dup->status = GIT_DELTA_MODIFIED;
+		return dup;
+	}
+
+	return git_diff__merge_like_cgit(a, b, pool);
+}
+
+static int build_workdir_tree(
+	git_tree **tree_out,
+	git_index *index,
+	git_commit *b_commit)
+{
+	git_repository *repo = git_index_owner(index);
+	git_tree *b_tree = NULL;
+	git_diff *diff = NULL, *idx_to_wd = NULL;
+	git_diff_options opts = GIT_DIFF_OPTIONS_INIT;
+	struct stash_update_rules data = {0};
+	int error;
+
+	opts.flags = GIT_DIFF_IGNORE_SUBMODULES | GIT_DIFF_INCLUDE_UNTRACKED;
+
+	if ((error = git_commit_tree(&b_tree, b_commit)) < 0)
+		goto cleanup;
+
+	if ((error = git_diff_tree_to_index(&diff, repo, b_tree, index, &opts)) < 0 ||
+		(error = git_diff_index_to_workdir(&idx_to_wd, repo, index, &opts)) < 0 ||
+		(error = git_diff__merge(diff, idx_to_wd, stash_delta_merge)) < 0)
+		goto cleanup;
+
+	data.include_changed = true;
+
+	if ((error = stash_update_index_from_diff(index, diff, &data)) < 0)
+		goto cleanup;
+
+	error = build_tree_from_index(tree_out, index);
+
+cleanup:
+	git_diff_free(idx_to_wd);
+	git_diff_free(diff);
+	git_tree_free(b_tree);
+
+	return error;
+}
+
+static int commit_worktree(
+	git_oid *w_commit_oid,
+	git_index *index,
+	const git_signature *stasher,
+	const char *message,
+	git_commit *i_commit,
+	git_commit *b_commit,
+	git_commit *u_commit)
+{
+	int error = 0;
+	git_tree *w_tree = NULL, *i_tree = NULL;
+	const git_commit *parents[] = {	NULL, NULL,	NULL };
+
+	parents[0] = b_commit;
+	parents[1] = i_commit;
+	parents[2] = u_commit;
+
+	if ((error = git_commit_tree(&i_tree, i_commit)) < 0)
+		goto cleanup;
+
+	if ((error = git_index_read_tree(index, i_tree)) < 0)
+		goto cleanup;
+
+	if ((error = build_workdir_tree(&w_tree, index, b_commit)) < 0)
+		goto cleanup;
+
+	error = git_commit_create(
+		w_commit_oid,
+		git_index_owner(index),
+		NULL,
+		stasher,
+		stasher,
+		NULL,
+		message,
+		w_tree,
+		u_commit ? 3 : 2,
+		parents);
+
+cleanup:
+	git_tree_free(i_tree);
+	git_tree_free(w_tree);
+	return error;
+}
+
+static int prepare_worktree_commit_message(
+	git_buf* msg,
+	const char *user_message)
+{
+	git_buf buf = GIT_BUF_INIT;
+	int error;
+
+	if ((error = git_buf_set(&buf, git_buf_cstr(msg), git_buf_len(msg))) < 0)
+		return error;
+
+	git_buf_clear(msg);
+
+	if (!user_message)
+		git_buf_printf(msg, "WIP on %s", git_buf_cstr(&buf));
+	else {
+		const char *colon;
+
+		if ((colon = strchr(git_buf_cstr(&buf), ':')) == NULL)
+			goto cleanup;
+
+		git_buf_puts(msg, "On ");
+		git_buf_put(msg, git_buf_cstr(&buf), colon - buf.ptr);
+		git_buf_printf(msg, ": %s\n", user_message);
+	}
+
+	error = (git_buf_oom(msg) || git_buf_oom(&buf)) ? -1 : 0;
+
+cleanup:
+	git_buf_free(&buf);
+
+	return error;
+}
+
+static int update_reflog(
+	git_oid *w_commit_oid,
+	git_repository *repo,
+	const char *message)
+{
+	git_reference *stash;
+	int error;
+
+	if ((error = git_reference_ensure_log(repo, GIT_REFS_STASH_FILE)) < 0)
+		return error;
+
+	error = git_reference_create(&stash, repo, GIT_REFS_STASH_FILE, w_commit_oid, 1, message);
+
+	git_reference_free(stash);
+
+	return error;
+}
+
+static int is_dirty_cb(const char *path, unsigned int status, void *payload)
+{
+	GIT_UNUSED(path);
+	GIT_UNUSED(status);
+	GIT_UNUSED(payload);
+
+	return GIT_PASSTHROUGH;
+}
+
+static int ensure_there_are_changes_to_stash(
+	git_repository *repo,
+	bool include_untracked_files,
+	bool include_ignored_files)
+{
+	int error;
+	git_status_options opts = GIT_STATUS_OPTIONS_INIT;
+
+	opts.show  = GIT_STATUS_SHOW_INDEX_AND_WORKDIR;
+	opts.flags = GIT_STATUS_OPT_EXCLUDE_SUBMODULES;
+
+	if (include_untracked_files)
+		opts.flags |= GIT_STATUS_OPT_INCLUDE_UNTRACKED |
+			GIT_STATUS_OPT_RECURSE_UNTRACKED_DIRS;
+
+	if (include_ignored_files)
+		opts.flags |= GIT_STATUS_OPT_INCLUDE_IGNORED |
+			GIT_STATUS_OPT_RECURSE_IGNORED_DIRS;
+
+	error = git_status_foreach_ext(repo, &opts, is_dirty_cb, NULL);
+
+	if (error == GIT_PASSTHROUGH)
+		return 0;
+
+	if (!error)
+		return create_error(GIT_ENOTFOUND, "there is nothing to stash.");
+
+	return error;
+}
+
+static int reset_index_and_workdir(
+	git_repository *repo,
+	git_commit *commit,
+	bool remove_untracked,
+	bool remove_ignored)
+{
+	git_checkout_options opts = GIT_CHECKOUT_OPTIONS_INIT;
+
+	opts.checkout_strategy = GIT_CHECKOUT_FORCE;
+
+	if (remove_untracked)
+		opts.checkout_strategy |= GIT_CHECKOUT_REMOVE_UNTRACKED;
+
+	if (remove_ignored)
+		opts.checkout_strategy |= GIT_CHECKOUT_REMOVE_IGNORED;
+
+	return git_checkout_tree(repo, (git_object *)commit, &opts);
+}
+
+int git_stash_save(
+	git_oid *out,
+	git_repository *repo,
+	const git_signature *stasher,
+	const char *message,
+	uint32_t flags)
+{
+	git_index *index = NULL;
+	git_commit *b_commit = NULL, *i_commit = NULL, *u_commit = NULL;
+	git_buf msg = GIT_BUF_INIT;
+	int error;
+
+	assert(out && repo && stasher);
+
+	if ((error = git_repository__ensure_not_bare(repo, "stash save")) < 0)
+		return error;
+
+	if ((error = retrieve_base_commit_and_message(&b_commit, &msg, repo)) < 0)
+		goto cleanup;
+
+	if ((error = ensure_there_are_changes_to_stash(
+		repo,
+		(flags & GIT_STASH_INCLUDE_UNTRACKED) != 0,
+		(flags & GIT_STASH_INCLUDE_IGNORED) != 0)) < 0)
+		goto cleanup;
+
+	if ((error = git_repository_index(&index, repo)) < 0)
+		goto cleanup;
+
+	if ((error = commit_index(
+			&i_commit, index, stasher, git_buf_cstr(&msg), b_commit)) < 0)
+		goto cleanup;
+
+	if ((flags & (GIT_STASH_INCLUDE_UNTRACKED | GIT_STASH_INCLUDE_IGNORED)) &&
+		(error = commit_untracked(
+			&u_commit, index, stasher, git_buf_cstr(&msg),
+			i_commit, flags)) < 0)
+		goto cleanup;
+
+	if ((error = prepare_worktree_commit_message(&msg, message)) < 0)
+		goto cleanup;
+
+	if ((error = commit_worktree(
+			out, index, stasher, git_buf_cstr(&msg),
+			i_commit, b_commit, u_commit)) < 0)
+		goto cleanup;
+
+	git_buf_rtrim(&msg);
+
+	if ((error = update_reflog(out, repo, git_buf_cstr(&msg))) < 0)
+		goto cleanup;
+
+	if ((error = reset_index_and_workdir(
+		repo,
+		((flags & GIT_STASH_KEEP_INDEX) != 0) ? i_commit : b_commit,
+		(flags & GIT_STASH_INCLUDE_UNTRACKED) != 0,
+		(flags & GIT_STASH_INCLUDE_IGNORED) != 0)) < 0)
+		goto cleanup;
+
+cleanup:
+
+	git_buf_free(&msg);
+	git_commit_free(i_commit);
+	git_commit_free(b_commit);
+	git_commit_free(u_commit);
+	git_index_free(index);
+
+	return error;
+}
+
+static int retrieve_stash_commit(
+	git_commit **commit,
+	git_repository *repo,
+	size_t index)
+{
+	git_reference *stash = NULL;
+	git_reflog *reflog = NULL;
+	int error;
+	size_t max;
+	const git_reflog_entry *entry;
+
+	if ((error = git_reference_lookup(&stash, repo, GIT_REFS_STASH_FILE)) < 0)
+		goto cleanup;
+
+	if ((error = git_reflog_read(&reflog, repo, GIT_REFS_STASH_FILE)) < 0)
+		goto cleanup;
+
+	max = git_reflog_entrycount(reflog);
+	if (!max || index > max - 1) {
+		error = GIT_ENOTFOUND;
+		giterr_set(GITERR_STASH, "no stashed state at position %" PRIuZ, index);
+		goto cleanup;
+	}
+
+	entry = git_reflog_entry_byindex(reflog, index);
+	if ((error = git_commit_lookup(commit, repo, git_reflog_entry_id_new(entry))) < 0)
+		goto cleanup;
+
+cleanup:
+	git_reference_free(stash);
+	git_reflog_free(reflog);
+	return error;
+}
+
+static int retrieve_stash_trees(
+	git_tree **out_stash_tree,
+	git_tree **out_base_tree,
+	git_tree **out_index_tree,
+	git_tree **out_index_parent_tree,
+	git_tree **out_untracked_tree,
+	git_commit *stash_commit)
+{
+	git_tree *stash_tree = NULL;
+	git_commit *base_commit = NULL;
+	git_tree *base_tree = NULL;
+	git_commit *index_commit = NULL;
+	git_tree *index_tree = NULL;
+	git_commit *index_parent_commit = NULL;
+	git_tree *index_parent_tree = NULL;
+	git_commit *untracked_commit = NULL;
+	git_tree *untracked_tree = NULL;
+	int error;
+
+	if ((error = git_commit_tree(&stash_tree, stash_commit)) < 0)
+		goto cleanup;
+
+	if ((error = git_commit_parent(&base_commit, stash_commit, 0)) < 0)
+		goto cleanup;
+	if ((error = git_commit_tree(&base_tree, base_commit)) < 0)
+		goto cleanup;
+
+	if ((error = git_commit_parent(&index_commit, stash_commit, 1)) < 0)
+		goto cleanup;
+	if ((error = git_commit_tree(&index_tree, index_commit)) < 0)
+		goto cleanup;
+
+	if ((error = git_commit_parent(&index_parent_commit, index_commit, 0)) < 0)
+		goto cleanup;
+	if ((error = git_commit_tree(&index_parent_tree, index_parent_commit)) < 0)
+		goto cleanup;
+
+	if (git_commit_parentcount(stash_commit) == 3) {
+		if ((error = git_commit_parent(&untracked_commit, stash_commit, 2)) < 0)
+			goto cleanup;
+		if ((error = git_commit_tree(&untracked_tree, untracked_commit)) < 0)
+			goto cleanup;
+	}
+
+	*out_stash_tree = stash_tree;
+	*out_base_tree = base_tree;
+	*out_index_tree = index_tree;
+	*out_index_parent_tree = index_parent_tree;
+	*out_untracked_tree = untracked_tree;
+
+cleanup:
+	git_commit_free(untracked_commit);
+	git_commit_free(index_parent_commit);
+	git_commit_free(index_commit);
+	git_commit_free(base_commit);
+	if (error < 0) {
+		git_tree_free(stash_tree);
+		git_tree_free(base_tree);
+		git_tree_free(index_tree);
+		git_tree_free(index_parent_tree);
+		git_tree_free(untracked_tree);
+	}
+	return error;
+}
+
+static int merge_indexes(
+	git_index **out,
+	git_repository *repo,
+	git_tree *ancestor_tree,
+	git_index *ours_index,
+	git_index *theirs_index)
+{
+	git_iterator *ancestor = NULL, *ours = NULL, *theirs = NULL;
+	git_iterator_options iter_opts = GIT_ITERATOR_OPTIONS_INIT;
+	int error;
+
+	iter_opts.flags = GIT_ITERATOR_DONT_IGNORE_CASE;
+
+	if ((error = git_iterator_for_tree(&ancestor, ancestor_tree, &iter_opts)) < 0 ||
+		(error = git_iterator_for_index(&ours, repo, ours_index, &iter_opts)) < 0 ||
+		(error = git_iterator_for_index(&theirs, repo, theirs_index, &iter_opts)) < 0)
+		goto done;
+
+	error = git_merge__iterators(out, repo, ancestor, ours, theirs, NULL);
+
+done:
+	git_iterator_free(ancestor);
+	git_iterator_free(ours);
+	git_iterator_free(theirs);
+	return error;
+}
+
+static int merge_index_and_tree(
+	git_index **out,
+	git_repository *repo,
+	git_tree *ancestor_tree,
+	git_index *ours_index,
+	git_tree *theirs_tree)
+{
+	git_iterator *ancestor = NULL, *ours = NULL, *theirs = NULL;
+	git_iterator_options iter_opts = GIT_ITERATOR_OPTIONS_INIT;
+	int error;
+
+	iter_opts.flags = GIT_ITERATOR_DONT_IGNORE_CASE;
+
+	if ((error = git_iterator_for_tree(&ancestor, ancestor_tree, &iter_opts)) < 0 ||
+		(error = git_iterator_for_index(&ours, repo, ours_index, &iter_opts)) < 0 ||
+		(error = git_iterator_for_tree(&theirs, theirs_tree, &iter_opts)) < 0)
+		goto done;
+
+	error = git_merge__iterators(out, repo, ancestor, ours, theirs, NULL);
+
+done:
+	git_iterator_free(ancestor);
+	git_iterator_free(ours);
+	git_iterator_free(theirs);
+	return error;
+}
+
+static void normalize_apply_options(
+	git_stash_apply_options *opts,
+	const git_stash_apply_options *given_apply_opts)
+{
+	if (given_apply_opts != NULL) {
+		memcpy(opts, given_apply_opts, sizeof(git_stash_apply_options));
+	} else {
+		git_stash_apply_options default_apply_opts = GIT_STASH_APPLY_OPTIONS_INIT;
+		memcpy(opts, &default_apply_opts, sizeof(git_stash_apply_options));
+	}
+
+	if (!opts->checkout_options.our_label)
+		opts->checkout_options.our_label = "Updated upstream";
+
+	if (!opts->checkout_options.their_label)
+		opts->checkout_options.their_label = "Stashed changes";
+}
+
+int git_stash_apply_init_options(git_stash_apply_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_stash_apply_options, GIT_STASH_APPLY_OPTIONS_INIT);
+	return 0;
+}
+
+#define NOTIFY_PROGRESS(opts, progress_type)				\
+	do {								\
+		if ((opts).progress_cb &&				\
+		    (error = (opts).progress_cb((progress_type), (opts).progress_payload))) { \
+			error = (error < 0) ? error : -1;		\
+			goto cleanup;					\
+		}							\
+	} while(false);
+
+static int ensure_clean_index(git_repository *repo, git_index *index)
+{
+	git_tree *head_tree = NULL;
+	git_diff *index_diff = NULL;
+	int error = 0;
+
+	if ((error = git_repository_head_tree(&head_tree, repo)) < 0 ||
+		(error = git_diff_tree_to_index(
+			&index_diff, repo, head_tree, index, NULL)) < 0)
+		goto done;
+
+	if (git_diff_num_deltas(index_diff) > 0) {
+		giterr_set(GITERR_STASH, "%" PRIuZ " uncommitted changes exist in the index",
+			git_diff_num_deltas(index_diff));
+		error = GIT_EUNCOMMITTED;
+	}
+
+done:
+	git_diff_free(index_diff);
+	git_tree_free(head_tree);
+	return error;
+}
+
+static int stage_new_file(const git_index_entry **entries, void *data)
+{
+	git_index *index = data;
+
+	if(entries[0] == NULL)
+		return git_index_add(index, entries[1]);
+	else
+		return git_index_add(index, entries[0]);
+}
+
+static int stage_new_files(
+	git_index **out,
+	git_tree *parent_tree,
+	git_tree *tree)
+{
+	git_iterator *iterators[2] = { NULL, NULL };
+	git_iterator_options iterator_options = GIT_ITERATOR_OPTIONS_INIT;
+	git_index *index = NULL;
+	int error;
+
+	if ((error = git_index_new(&index)) < 0 ||
+		(error = git_iterator_for_tree(
+			&iterators[0], parent_tree, &iterator_options)) < 0 ||
+		(error = git_iterator_for_tree(
+			&iterators[1], tree, &iterator_options)) < 0)
+		goto done;
+
+	error = git_iterator_walk(iterators, 2, stage_new_file, index);
+
+done:
+	if (error < 0)
+		git_index_free(index);
+	else
+		*out = index;
+
+	git_iterator_free(iterators[0]);
+	git_iterator_free(iterators[1]);
+
+	return error;
+}
+
+int git_stash_apply(
+	git_repository *repo,
+	size_t index,
+	const git_stash_apply_options *given_opts)
+{
+	git_stash_apply_options opts;
+	unsigned int checkout_strategy;
+	git_commit *stash_commit = NULL;
+	git_tree *stash_tree = NULL;
+	git_tree *stash_parent_tree = NULL;
+	git_tree *index_tree = NULL;
+	git_tree *index_parent_tree = NULL;
+	git_tree *untracked_tree = NULL;
+	git_index *stash_adds = NULL;
+	git_index *repo_index = NULL;
+	git_index *unstashed_index = NULL;
+	git_index *modified_index = NULL;
+	git_index *untracked_index = NULL;
+	int error;
+
+	GITERR_CHECK_VERSION(given_opts, GIT_STASH_APPLY_OPTIONS_VERSION, "git_stash_apply_options");
+
+	normalize_apply_options(&opts, given_opts);
+	checkout_strategy = opts.checkout_options.checkout_strategy;
+
+	NOTIFY_PROGRESS(opts, GIT_STASH_APPLY_PROGRESS_LOADING_STASH);
+
+	/* Retrieve commit corresponding to the given stash */
+	if ((error = retrieve_stash_commit(&stash_commit, repo, index)) < 0)
+		goto cleanup;
+
+	/* Retrieve all trees in the stash */
+	if ((error = retrieve_stash_trees(
+			&stash_tree, &stash_parent_tree, &index_tree,
+			&index_parent_tree, &untracked_tree, stash_commit)) < 0)
+		goto cleanup;
+
+	/* Load repo index */
+	if ((error = git_repository_index(&repo_index, repo)) < 0)
+		goto cleanup;
+
+	NOTIFY_PROGRESS(opts, GIT_STASH_APPLY_PROGRESS_ANALYZE_INDEX);
+
+	if ((error = ensure_clean_index(repo, repo_index)) < 0)
+		goto cleanup;
+
+	/* Restore index if required */
+	if ((opts.flags & GIT_STASH_APPLY_REINSTATE_INDEX) &&
+		git_oid_cmp(git_tree_id(stash_parent_tree), git_tree_id(index_tree))) {
+
+		if ((error = merge_index_and_tree(
+				&unstashed_index, repo, index_parent_tree, repo_index, index_tree)) < 0)
+			goto cleanup;
+
+		if (git_index_has_conflicts(unstashed_index)) {
+			error = GIT_ECONFLICT;
+			goto cleanup;
+		}
+
+	/* Otherwise, stage any new files in the stash tree.  (Note: their
+	 * previously unstaged contents are staged, not the previously staged.)
+	 */
+	} else if ((opts.flags & GIT_STASH_APPLY_REINSTATE_INDEX) == 0) {
+		if ((error = stage_new_files(
+				&stash_adds, stash_parent_tree, stash_tree)) < 0 ||
+			(error = merge_indexes(
+				&unstashed_index, repo, stash_parent_tree, repo_index, stash_adds)) < 0)
+			goto cleanup;
+	}
+
+	NOTIFY_PROGRESS(opts, GIT_STASH_APPLY_PROGRESS_ANALYZE_MODIFIED);
+
+	/* Restore modified files in workdir */
+	if ((error = merge_index_and_tree(
+			&modified_index, repo, stash_parent_tree, repo_index, stash_tree)) < 0)
+		goto cleanup;
+
+	/* If applicable, restore untracked / ignored files in workdir */
+	if (untracked_tree) {
+		NOTIFY_PROGRESS(opts, GIT_STASH_APPLY_PROGRESS_ANALYZE_UNTRACKED);
+
+		if ((error = merge_index_and_tree(&untracked_index, repo, NULL, repo_index, untracked_tree)) < 0)
+			goto cleanup;
+	}
+
+	if (untracked_index) {
+		opts.checkout_options.checkout_strategy |= GIT_CHECKOUT_DONT_UPDATE_INDEX;
+
+		NOTIFY_PROGRESS(opts, GIT_STASH_APPLY_PROGRESS_CHECKOUT_UNTRACKED);
+
+		if ((error = git_checkout_index(repo, untracked_index, &opts.checkout_options)) < 0)
+			goto cleanup;
+
+		opts.checkout_options.checkout_strategy = checkout_strategy;
+	}
+
+
+	/* If there are conflicts in the modified index, then we need to actually
+	 * check that out as the repo's index.  Otherwise, we don't update the
+	 * index.
+	 */
+
+	if (!git_index_has_conflicts(modified_index))
+		opts.checkout_options.checkout_strategy |= GIT_CHECKOUT_DONT_UPDATE_INDEX;
+
+	/* Check out the modified index using the existing repo index as baseline,
+	 * so that existing modifications in the index can be rewritten even when
+	 * checking out safely.
+	 */
+	opts.checkout_options.baseline_index = repo_index;
+
+	NOTIFY_PROGRESS(opts, GIT_STASH_APPLY_PROGRESS_CHECKOUT_MODIFIED);
+
+	if ((error = git_checkout_index(repo, modified_index, &opts.checkout_options)) < 0)
+		goto cleanup;
+
+	if (unstashed_index && !git_index_has_conflicts(modified_index)) {
+		if ((error = git_index_read_index(repo_index, unstashed_index)) < 0)
+			goto cleanup;
+	}
+
+	NOTIFY_PROGRESS(opts, GIT_STASH_APPLY_PROGRESS_DONE);
+
+	error = git_index_write(repo_index);
+
+cleanup:
+	git_index_free(untracked_index);
+	git_index_free(modified_index);
+	git_index_free(unstashed_index);
+	git_index_free(stash_adds);
+	git_index_free(repo_index);
+	git_tree_free(untracked_tree);
+	git_tree_free(index_parent_tree);
+	git_tree_free(index_tree);
+	git_tree_free(stash_parent_tree);
+	git_tree_free(stash_tree);
+	git_commit_free(stash_commit);
+	return error;
+}
+
+int git_stash_foreach(
+	git_repository *repo,
+	git_stash_cb callback,
+	void *payload)
+{
+	git_reference *stash;
+	git_reflog *reflog = NULL;
+	int error;
+	size_t i, max;
+	const git_reflog_entry *entry;
+
+	error = git_reference_lookup(&stash, repo, GIT_REFS_STASH_FILE);
+	if (error == GIT_ENOTFOUND) {
+		giterr_clear();
+		return 0;
+	}
+	if (error < 0)
+		goto cleanup;
+
+	if ((error = git_reflog_read(&reflog, repo, GIT_REFS_STASH_FILE)) < 0)
+		goto cleanup;
+
+	max = git_reflog_entrycount(reflog);
+	for (i = 0; i < max; i++) {
+		entry = git_reflog_entry_byindex(reflog, i);
+
+		error = callback(i,
+			git_reflog_entry_message(entry),
+			git_reflog_entry_id_new(entry),
+			payload);
+
+		if (error) {
+			giterr_set_after_callback(error);
+			break;
+		}
+	}
+
+cleanup:
+	git_reference_free(stash);
+	git_reflog_free(reflog);
+	return error;
+}
+
+int git_stash_drop(
+	git_repository *repo,
+	size_t index)
+{
+	git_transaction *tx;
+	git_reference *stash = NULL;
+	git_reflog *reflog = NULL;
+	size_t max;
+	int error;
+
+	if ((error = git_transaction_new(&tx, repo)) < 0)
+		return error;
+
+	if ((error = git_transaction_lock_ref(tx, GIT_REFS_STASH_FILE)) < 0)
+		goto cleanup;
+
+	if ((error = git_reference_lookup(&stash, repo, GIT_REFS_STASH_FILE)) < 0)
+		goto cleanup;
+
+	if ((error = git_reflog_read(&reflog, repo, GIT_REFS_STASH_FILE)) < 0)
+		goto cleanup;
+
+	max = git_reflog_entrycount(reflog);
+
+	if (!max || index > max - 1) {
+		error = GIT_ENOTFOUND;
+		giterr_set(GITERR_STASH, "no stashed state at position %" PRIuZ, index);
+		goto cleanup;
+	}
+
+	if ((error = git_reflog_drop(reflog, index, true)) < 0)
+		goto cleanup;
+
+	if ((error = git_transaction_set_reflog(tx, GIT_REFS_STASH_FILE, reflog)) < 0)
+		goto cleanup;
+
+	if (max == 1) {
+		if ((error = git_transaction_remove(tx, GIT_REFS_STASH_FILE)) < 0)
+			goto cleanup;
+	} else if (index == 0) {
+		const git_reflog_entry *entry;
+
+		entry = git_reflog_entry_byindex(reflog, 0);
+		if ((error = git_transaction_set_target(tx, GIT_REFS_STASH_FILE, &entry->oid_cur, NULL, NULL)) < 0)
+			goto cleanup;
+	}
+
+	error = git_transaction_commit(tx);
+
+cleanup:
+	git_reference_free(stash);
+	git_transaction_free(tx);
+	git_reflog_free(reflog);
+	return error;
+}
+
+int git_stash_pop(
+	git_repository *repo,
+	size_t index,
+	const git_stash_apply_options *options)
+{
+	int error;
+
+	if ((error = git_stash_apply(repo, index, options)) < 0)
+		return error;
+
+	return git_stash_drop(repo, index);
+}

vendor/libgit2-sys/libgit2/src/status.c

diff --git a/vendor/libgit2-sys/libgit2/src/status.c b/vendor/libgit2-sys/libgit2/src/status.c
new file mode 100644
index 0000000..f547bd4
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/status.c
@@ -0,0 +1,570 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "status.h"
+
+#include "git2.h"
+#include "fileops.h"
+#include "hash.h"
+#include "vector.h"
+#include "tree.h"
+#include "git2/status.h"
+#include "repository.h"
+#include "ignore.h"
+#include "index.h"
+
+#include "git2/diff.h"
+#include "diff.h"
+#include "diff_generate.h"
+
+static unsigned int index_delta2status(const git_diff_delta *head2idx)
+{
+	git_status_t st = GIT_STATUS_CURRENT;
+
+	switch (head2idx->status) {
+	case GIT_DELTA_ADDED:
+	case GIT_DELTA_COPIED:
+		st = GIT_STATUS_INDEX_NEW;
+		break;
+	case GIT_DELTA_DELETED:
+		st = GIT_STATUS_INDEX_DELETED;
+		break;
+	case GIT_DELTA_MODIFIED:
+		st = GIT_STATUS_INDEX_MODIFIED;
+		break;
+	case GIT_DELTA_RENAMED:
+		st = GIT_STATUS_INDEX_RENAMED;
+
+		if (!git_oid_equal(&head2idx->old_file.id, &head2idx->new_file.id))
+			st |= GIT_STATUS_INDEX_MODIFIED;
+		break;
+	case GIT_DELTA_TYPECHANGE:
+		st = GIT_STATUS_INDEX_TYPECHANGE;
+		break;
+	case GIT_DELTA_CONFLICTED:
+		st = GIT_STATUS_CONFLICTED;
+		break;
+	default:
+		break;
+	}
+
+	return st;
+}
+
+static unsigned int workdir_delta2status(
+	git_diff *diff, git_diff_delta *idx2wd)
+{
+	git_status_t st = GIT_STATUS_CURRENT;
+
+	switch (idx2wd->status) {
+	case GIT_DELTA_ADDED:
+	case GIT_DELTA_COPIED:
+	case GIT_DELTA_UNTRACKED:
+		st = GIT_STATUS_WT_NEW;
+		break;
+	case GIT_DELTA_UNREADABLE:
+		st = GIT_STATUS_WT_UNREADABLE;
+		break;
+	case GIT_DELTA_DELETED:
+		st = GIT_STATUS_WT_DELETED;
+		break;
+	case GIT_DELTA_MODIFIED:
+		st = GIT_STATUS_WT_MODIFIED;
+		break;
+	case GIT_DELTA_IGNORED:
+		st = GIT_STATUS_IGNORED;
+		break;
+	case GIT_DELTA_RENAMED:
+		st = GIT_STATUS_WT_RENAMED;
+
+		if (!git_oid_equal(&idx2wd->old_file.id, &idx2wd->new_file.id)) {
+			/* if OIDs don't match, we might need to calculate them now to
+			 * discern between RENAMED vs RENAMED+MODIFED
+			 */
+			if (git_oid_iszero(&idx2wd->old_file.id) &&
+				diff->old_src == GIT_ITERATOR_TYPE_WORKDIR &&
+				!git_diff__oid_for_file(
+					&idx2wd->old_file.id, diff, idx2wd->old_file.path,
+					idx2wd->old_file.mode, idx2wd->old_file.size))
+			idx2wd->old_file.flags |= GIT_DIFF_FLAG_VALID_ID;
+
+			if (git_oid_iszero(&idx2wd->new_file.id) &&
+				diff->new_src == GIT_ITERATOR_TYPE_WORKDIR &&
+				!git_diff__oid_for_file(
+					&idx2wd->new_file.id, diff, idx2wd->new_file.path,
+					idx2wd->new_file.mode, idx2wd->new_file.size))
+				idx2wd->new_file.flags |= GIT_DIFF_FLAG_VALID_ID;
+
+			if (!git_oid_equal(&idx2wd->old_file.id, &idx2wd->new_file.id))
+				st |= GIT_STATUS_WT_MODIFIED;
+		}
+		break;
+	case GIT_DELTA_TYPECHANGE:
+		st = GIT_STATUS_WT_TYPECHANGE;
+		break;
+	case GIT_DELTA_CONFLICTED:
+		st = GIT_STATUS_CONFLICTED;
+		break;
+	default:
+		break;
+	}
+
+	return st;
+}
+
+static bool status_is_included(
+	git_status_list *status,
+	git_diff_delta *head2idx,
+	git_diff_delta *idx2wd)
+{
+	if (!(status->opts.flags & GIT_STATUS_OPT_EXCLUDE_SUBMODULES))
+		return 1;
+
+	/* if excluding submodules and this is a submodule everywhere */
+	if (head2idx) {
+		if (head2idx->status != GIT_DELTA_ADDED &&
+			head2idx->old_file.mode != GIT_FILEMODE_COMMIT)
+			return 1;
+		if (head2idx->status != GIT_DELTA_DELETED &&
+			head2idx->new_file.mode != GIT_FILEMODE_COMMIT)
+			return 1;
+	}
+	if (idx2wd) {
+		if (idx2wd->status != GIT_DELTA_ADDED &&
+			idx2wd->old_file.mode != GIT_FILEMODE_COMMIT)
+			return 1;
+		if (idx2wd->status != GIT_DELTA_DELETED &&
+			idx2wd->new_file.mode != GIT_FILEMODE_COMMIT)
+			return 1;
+	}
+
+	/* only get here if every valid mode is GIT_FILEMODE_COMMIT */
+	return 0;
+}
+
+static git_status_t status_compute(
+	git_status_list *status,
+	git_diff_delta *head2idx,
+	git_diff_delta *idx2wd)
+{
+	git_status_t st = GIT_STATUS_CURRENT;
+
+	if (head2idx)
+		st |= index_delta2status(head2idx);
+
+	if (idx2wd)
+		st |= workdir_delta2status(status->idx2wd, idx2wd);
+
+	return st;
+}
+
+static int status_collect(
+	git_diff_delta *head2idx,
+	git_diff_delta *idx2wd,
+	void *payload)
+{
+	git_status_list *status = payload;
+	git_status_entry *status_entry;
+
+	if (!status_is_included(status, head2idx, idx2wd))
+		return 0;
+
+	status_entry = git__malloc(sizeof(git_status_entry));
+	GITERR_CHECK_ALLOC(status_entry);
+
+	status_entry->status = status_compute(status, head2idx, idx2wd);
+	status_entry->head_to_index = head2idx;
+	status_entry->index_to_workdir = idx2wd;
+
+	return git_vector_insert(&status->paired, status_entry);
+}
+
+GIT_INLINE(int) status_entry_cmp_base(
+	const void *a,
+	const void *b,
+	int (*strcomp)(const char *a, const char *b))
+{
+	const git_status_entry *entry_a = a;
+	const git_status_entry *entry_b = b;
+	const git_diff_delta *delta_a, *delta_b;
+
+	delta_a = entry_a->index_to_workdir ? entry_a->index_to_workdir :
+		entry_a->head_to_index;
+	delta_b = entry_b->index_to_workdir ? entry_b->index_to_workdir :
+		entry_b->head_to_index;
+
+	if (!delta_a && delta_b)
+		return -1;
+	if (delta_a && !delta_b)
+		return 1;
+	if (!delta_a && !delta_b)
+		return 0;
+
+	return strcomp(delta_a->new_file.path, delta_b->new_file.path);
+}
+
+static int status_entry_icmp(const void *a, const void *b)
+{
+	return status_entry_cmp_base(a, b, git__strcasecmp);
+}
+
+static int status_entry_cmp(const void *a, const void *b)
+{
+	return status_entry_cmp_base(a, b, git__strcmp);
+}
+
+static git_status_list *git_status_list_alloc(git_index *index)
+{
+	git_status_list *status = NULL;
+	int (*entrycmp)(const void *a, const void *b);
+
+	if (!(status = git__calloc(1, sizeof(git_status_list))))
+		return NULL;
+
+	entrycmp = index->ignore_case ? status_entry_icmp : status_entry_cmp;
+
+	if (git_vector_init(&status->paired, 0, entrycmp) < 0) {
+		git__free(status);
+		return NULL;
+	}
+
+	return status;
+}
+
+static int status_validate_options(const git_status_options *opts)
+{
+	if (!opts)
+		return 0;
+
+	GITERR_CHECK_VERSION(opts, GIT_STATUS_OPTIONS_VERSION, "git_status_options");
+
+	if (opts->show > GIT_STATUS_SHOW_WORKDIR_ONLY) {
+		giterr_set(GITERR_INVALID, "unknown status 'show' option");
+		return -1;
+	}
+
+	if ((opts->flags & GIT_STATUS_OPT_NO_REFRESH) != 0 &&
+		(opts->flags & GIT_STATUS_OPT_UPDATE_INDEX) != 0) {
+		giterr_set(GITERR_INVALID, "updating index from status "
+			"is not allowed when index refresh is disabled");
+		return -1;
+	}
+
+	return 0;
+}
+
+int git_status_list_new(
+	git_status_list **out,
+	git_repository *repo,
+	const git_status_options *opts)
+{
+	git_index *index = NULL;
+	git_status_list *status = NULL;
+	git_diff_options diffopt = GIT_DIFF_OPTIONS_INIT;
+	git_diff_find_options findopt = GIT_DIFF_FIND_OPTIONS_INIT;
+	git_tree *head = NULL;
+	git_status_show_t show =
+		opts ? opts->show : GIT_STATUS_SHOW_INDEX_AND_WORKDIR;
+	int error = 0;
+	unsigned int flags = opts ? opts->flags : GIT_STATUS_OPT_DEFAULTS;
+
+	*out = NULL;
+
+	if (status_validate_options(opts) < 0)
+		return -1;
+
+	if ((error = git_repository__ensure_not_bare(repo, "status")) < 0 ||
+		(error = git_repository_index(&index, repo)) < 0)
+		return error;
+	
+	if (opts != NULL && opts->baseline != NULL) {
+		head = opts->baseline;
+	} else {
+		/* if there is no HEAD, that's okay - we'll make an empty iterator */
+		if ((error = git_repository_head_tree(&head, repo)) < 0) {
+			if (error != GIT_ENOTFOUND && error != GIT_EUNBORNBRANCH)
+				goto done;
+			giterr_clear();
+		}
+	}
+
+	/* refresh index from disk unless prevented */
+	if ((flags & GIT_STATUS_OPT_NO_REFRESH) == 0 &&
+		git_index_read(index, false) < 0)
+		giterr_clear();
+
+	status = git_status_list_alloc(index);
+	GITERR_CHECK_ALLOC(status);
+
+	if (opts) {
+		memcpy(&status->opts, opts, sizeof(git_status_options));
+		memcpy(&diffopt.pathspec, &opts->pathspec, sizeof(diffopt.pathspec));
+	}
+
+	diffopt.flags = GIT_DIFF_INCLUDE_TYPECHANGE;
+	findopt.flags = GIT_DIFF_FIND_FOR_UNTRACKED;
+
+	if ((flags & GIT_STATUS_OPT_INCLUDE_UNTRACKED) != 0)
+		diffopt.flags = diffopt.flags | GIT_DIFF_INCLUDE_UNTRACKED;
+	if ((flags & GIT_STATUS_OPT_INCLUDE_IGNORED) != 0)
+		diffopt.flags = diffopt.flags | GIT_DIFF_INCLUDE_IGNORED;
+	if ((flags & GIT_STATUS_OPT_INCLUDE_UNMODIFIED) != 0)
+		diffopt.flags = diffopt.flags | GIT_DIFF_INCLUDE_UNMODIFIED;
+	if ((flags & GIT_STATUS_OPT_RECURSE_UNTRACKED_DIRS) != 0)
+		diffopt.flags = diffopt.flags | GIT_DIFF_RECURSE_UNTRACKED_DIRS;
+	if ((flags & GIT_STATUS_OPT_DISABLE_PATHSPEC_MATCH) != 0)
+		diffopt.flags = diffopt.flags | GIT_DIFF_DISABLE_PATHSPEC_MATCH;
+	if ((flags & GIT_STATUS_OPT_RECURSE_IGNORED_DIRS) != 0)
+		diffopt.flags = diffopt.flags | GIT_DIFF_RECURSE_IGNORED_DIRS;
+	if ((flags & GIT_STATUS_OPT_EXCLUDE_SUBMODULES) != 0)
+		diffopt.flags = diffopt.flags | GIT_DIFF_IGNORE_SUBMODULES;
+	if ((flags & GIT_STATUS_OPT_UPDATE_INDEX) != 0)
+		diffopt.flags = diffopt.flags | GIT_DIFF_UPDATE_INDEX;
+	if ((flags & GIT_STATUS_OPT_INCLUDE_UNREADABLE) != 0)
+		diffopt.flags = diffopt.flags | GIT_DIFF_INCLUDE_UNREADABLE;
+	if ((flags & GIT_STATUS_OPT_INCLUDE_UNREADABLE_AS_UNTRACKED) != 0)
+		diffopt.flags = diffopt.flags | GIT_DIFF_INCLUDE_UNREADABLE_AS_UNTRACKED;
+
+	if ((flags & GIT_STATUS_OPT_RENAMES_FROM_REWRITES) != 0)
+		findopt.flags = findopt.flags |
+			GIT_DIFF_FIND_AND_BREAK_REWRITES |
+			GIT_DIFF_FIND_RENAMES_FROM_REWRITES |
+			GIT_DIFF_BREAK_REWRITES_FOR_RENAMES_ONLY;
+
+	if (show != GIT_STATUS_SHOW_WORKDIR_ONLY) {
+		if ((error = git_diff_tree_to_index(
+				&status->head2idx, repo, head, index, &diffopt)) < 0)
+			goto done;
+
+		if ((flags & GIT_STATUS_OPT_RENAMES_HEAD_TO_INDEX) != 0 &&
+			(error = git_diff_find_similar(status->head2idx, &findopt)) < 0)
+			goto done;
+	}
+
+	if (show != GIT_STATUS_SHOW_INDEX_ONLY) {
+		if ((error = git_diff_index_to_workdir(
+				&status->idx2wd, repo, index, &diffopt)) < 0) {
+			goto done;
+		}
+
+		if ((flags & GIT_STATUS_OPT_RENAMES_INDEX_TO_WORKDIR) != 0 &&
+			(error = git_diff_find_similar(status->idx2wd, &findopt)) < 0)
+			goto done;
+	}
+
+	error = git_diff__paired_foreach(
+		status->head2idx, status->idx2wd, status_collect, status);
+	if (error < 0)
+		goto done;
+
+	if (flags & GIT_STATUS_OPT_SORT_CASE_SENSITIVELY)
+		git_vector_set_cmp(&status->paired, status_entry_cmp);
+	if (flags & GIT_STATUS_OPT_SORT_CASE_INSENSITIVELY)
+		git_vector_set_cmp(&status->paired, status_entry_icmp);
+
+	if ((flags &
+		 (GIT_STATUS_OPT_RENAMES_HEAD_TO_INDEX |
+		  GIT_STATUS_OPT_RENAMES_INDEX_TO_WORKDIR |
+		  GIT_STATUS_OPT_SORT_CASE_SENSITIVELY |
+		  GIT_STATUS_OPT_SORT_CASE_INSENSITIVELY)) != 0)
+		git_vector_sort(&status->paired);
+
+done:
+	if (error < 0) {
+		git_status_list_free(status);
+		status = NULL;
+	}
+
+	*out = status;
+
+	if (opts == NULL || opts->baseline != head)
+		git_tree_free(head);
+	git_index_free(index);
+
+	return error;
+}
+
+size_t git_status_list_entrycount(git_status_list *status)
+{
+	assert(status);
+
+	return status->paired.length;
+}
+
+const git_status_entry *git_status_byindex(git_status_list *status, size_t i)
+{
+	assert(status);
+
+	return git_vector_get(&status->paired, i);
+}
+
+void git_status_list_free(git_status_list *status)
+{
+	if (status == NULL)
+		return;
+
+	git_diff_free(status->head2idx);
+	git_diff_free(status->idx2wd);
+
+	git_vector_free_deep(&status->paired);
+
+	git__memzero(status, sizeof(*status));
+	git__free(status);
+}
+
+int git_status_foreach_ext(
+	git_repository *repo,
+	const git_status_options *opts,
+	git_status_cb cb,
+	void *payload)
+{
+	git_status_list *status;
+	const git_status_entry *status_entry;
+	size_t i;
+	int error = 0;
+
+	if ((error = git_status_list_new(&status, repo, opts)) < 0) {
+		return error;
+	}
+
+	git_vector_foreach(&status->paired, i, status_entry) {
+		const char *path = status_entry->head_to_index ?
+			status_entry->head_to_index->old_file.path :
+			status_entry->index_to_workdir->old_file.path;
+
+		if ((error = cb(path, status_entry->status, payload)) != 0) {
+			giterr_set_after_callback(error);
+			break;
+		}
+	}
+
+	git_status_list_free(status);
+
+	return error;
+}
+
+int git_status_foreach(git_repository *repo, git_status_cb cb, void *payload)
+{
+	return git_status_foreach_ext(repo, NULL, cb, payload);
+}
+
+struct status_file_info {
+	char *expected;
+	unsigned int count;
+	unsigned int status;
+	int fnm_flags;
+	int ambiguous;
+};
+
+static int get_one_status(const char *path, unsigned int status, void *data)
+{
+	struct status_file_info *sfi = data;
+	int (*strcomp)(const char *a, const char *b);
+
+	sfi->count++;
+	sfi->status = status;
+
+	strcomp = (sfi->fnm_flags & FNM_CASEFOLD) ? git__strcasecmp : git__strcmp;
+
+	if (sfi->count > 1 ||
+		(strcomp(sfi->expected, path) != 0 &&
+		 p_fnmatch(sfi->expected, path, sfi->fnm_flags) != 0))
+	{
+		sfi->ambiguous = true;
+		return GIT_EAMBIGUOUS; /* giterr_set will be done by caller */
+	}
+
+	return 0;
+}
+
+int git_status_file(
+	unsigned int *status_flags,
+	git_repository *repo,
+	const char *path)
+{
+	int error;
+	git_status_options opts = GIT_STATUS_OPTIONS_INIT;
+	struct status_file_info sfi = {0};
+	git_index *index;
+
+	assert(status_flags && repo && path);
+
+	if ((error = git_repository_index__weakptr(&index, repo)) < 0)
+		return error;
+
+	if ((sfi.expected = git__strdup(path)) == NULL)
+		return -1;
+	if (index->ignore_case)
+		sfi.fnm_flags = FNM_CASEFOLD;
+
+	opts.show = GIT_STATUS_SHOW_INDEX_AND_WORKDIR;
+	opts.flags = GIT_STATUS_OPT_INCLUDE_IGNORED |
+		GIT_STATUS_OPT_RECURSE_IGNORED_DIRS |
+		GIT_STATUS_OPT_INCLUDE_UNTRACKED |
+		GIT_STATUS_OPT_RECURSE_UNTRACKED_DIRS |
+		GIT_STATUS_OPT_INCLUDE_UNMODIFIED |
+		GIT_STATUS_OPT_DISABLE_PATHSPEC_MATCH;
+	opts.pathspec.count = 1;
+	opts.pathspec.strings = &sfi.expected;
+
+	error = git_status_foreach_ext(repo, &opts, get_one_status, &sfi);
+
+	if (error < 0 && sfi.ambiguous) {
+		giterr_set(GITERR_INVALID,
+			"ambiguous path '%s' given to git_status_file", sfi.expected);
+		error = GIT_EAMBIGUOUS;
+	}
+
+	if (!error && !sfi.count) {
+		giterr_set(GITERR_INVALID,
+			"attempt to get status of nonexistent file '%s'", path);
+		error = GIT_ENOTFOUND;
+	}
+
+	*status_flags = sfi.status;
+
+	git__free(sfi.expected);
+
+	return error;
+}
+
+int git_status_should_ignore(
+	int *ignored,
+	git_repository *repo,
+	const char *path)
+{
+	return git_ignore_path_is_ignored(ignored, repo, path);
+}
+
+int git_status_init_options(git_status_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_status_options, GIT_STATUS_OPTIONS_INIT);
+	return 0;
+}
+
+int git_status_list_get_perfdata(
+	git_diff_perfdata *out, const git_status_list *status)
+{
+	assert(out);
+	GITERR_CHECK_VERSION(out, GIT_DIFF_PERFDATA_VERSION, "git_diff_perfdata");
+
+	out->stat_calls = 0;
+	out->oid_calculations = 0;
+
+	if (status->head2idx) {
+		out->stat_calls += status->head2idx->perf.stat_calls;
+		out->oid_calculations += status->head2idx->perf.oid_calculations;
+	}
+	if (status->idx2wd) {
+		out->stat_calls += status->idx2wd->perf.stat_calls;
+		out->oid_calculations += status->idx2wd->perf.oid_calculations;
+	}
+
+	return 0;
+}
+

vendor/libgit2-sys/libgit2/src/status.h

diff --git a/vendor/libgit2-sys/libgit2/src/status.h b/vendor/libgit2-sys/libgit2/src/status.h
new file mode 100644
index 0000000..907479a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/status.h
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_status_h__
+#define INCLUDE_status_h__
+
+#include "common.h"
+
+#include "diff.h"
+#include "git2/status.h"
+#include "git2/diff.h"
+
+struct git_status_list {
+	git_status_options opts;
+
+	git_diff *head2idx;
+	git_diff *idx2wd;
+
+	git_vector paired;
+};
+
+#endif

vendor/libgit2-sys/libgit2/src/stream.h

diff --git a/vendor/libgit2-sys/libgit2/src/stream.h b/vendor/libgit2-sys/libgit2/src/stream.h
new file mode 100644
index 0000000..d354775
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/stream.h
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_stream_h__
+#define INCLUDE_stream_h__
+
+#include "common.h"
+#include "git2/sys/stream.h"
+
+GIT_INLINE(int) git_stream_connect(git_stream *st)
+{
+	return st->connect(st);
+}
+
+GIT_INLINE(int) git_stream_is_encrypted(git_stream *st)
+{
+	return st->encrypted;
+}
+
+GIT_INLINE(int) git_stream_certificate(git_cert **out, git_stream *st)
+{
+	if (!st->encrypted) {
+		giterr_set(GITERR_INVALID, "an unencrypted stream does not have a certificate");
+		return -1;
+	}
+
+	return st->certificate(out, st);
+}
+
+GIT_INLINE(int) git_stream_supports_proxy(git_stream *st)
+{
+	return st->proxy_support;
+}
+
+GIT_INLINE(int) git_stream_set_proxy(git_stream *st, const git_proxy_options *proxy_opts)
+{
+	if (!st->proxy_support) {
+		giterr_set(GITERR_INVALID, "proxy not supported on this stream");
+		return -1;
+	}
+
+	return st->set_proxy(st, proxy_opts);
+}
+
+GIT_INLINE(ssize_t) git_stream_read(git_stream *st, void *data, size_t len)
+{
+	return st->read(st, data, len);
+}
+
+GIT_INLINE(ssize_t) git_stream_write(git_stream *st, const char *data, size_t len, int flags)
+{
+	return st->write(st, data, len, flags);
+}
+
+GIT_INLINE(int) git_stream_close(git_stream *st)
+{
+	return st->close(st);
+}
+
+GIT_INLINE(void) git_stream_free(git_stream *st)
+{
+	if (!st)
+		return;
+
+	st->free(st);
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/streams/curl.c

diff --git a/vendor/libgit2-sys/libgit2/src/streams/curl.c b/vendor/libgit2-sys/libgit2/src/streams/curl.c
new file mode 100644
index 0000000..ee13be1
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/streams/curl.c
@@ -0,0 +1,385 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "streams/curl.h"
+
+#ifdef GIT_CURL
+
+#include <curl/curl.h>
+
+#include "stream.h"
+#include "git2/transport.h"
+#include "buffer.h"
+#include "global.h"
+#include "vector.h"
+#include "proxy.h"
+
+/* This is for backwards compatibility with curl<7.45.0. */
+#ifndef CURLINFO_ACTIVESOCKET
+# define CURLINFO_ACTIVESOCKET CURLINFO_LASTSOCKET
+# define GIT_CURL_BADSOCKET -1
+# define git_activesocket_t long
+#else
+# define GIT_CURL_BADSOCKET CURL_SOCKET_BAD
+# define git_activesocket_t curl_socket_t
+#endif
+
+typedef struct {
+	git_stream parent;
+	CURL *handle;
+	curl_socket_t socket;
+	char curl_error[CURL_ERROR_SIZE + 1];
+	git_cert_x509 cert_info;
+	git_strarray cert_info_strings;
+	git_proxy_options proxy;
+	git_cred *proxy_cred;
+} curl_stream;
+
+int git_curl_stream_global_init(void)
+{
+	if (curl_global_init(CURL_GLOBAL_ALL) != 0) {
+		giterr_set(GITERR_NET, "could not initialize curl");
+		return -1;
+	}
+
+	/* `curl_global_cleanup` is provided by libcurl */
+	git__on_shutdown(curl_global_cleanup);
+	return 0;
+}
+
+static int seterr_curl(curl_stream *s)
+{
+	giterr_set(GITERR_NET, "curl error: %s\n", s->curl_error);
+	return -1;
+}
+
+GIT_INLINE(int) error_no_credentials(void)
+{
+	giterr_set(GITERR_NET, "proxy authentication required, but no callback provided");
+	return GIT_EAUTH;
+}
+
+static int apply_proxy_creds(curl_stream *s)
+{
+	CURLcode res;
+	git_cred_userpass_plaintext *userpass;
+
+	if (!s->proxy_cred)
+		return GIT_ENOTFOUND;
+
+	userpass = (git_cred_userpass_plaintext *) s->proxy_cred;
+	if ((res = curl_easy_setopt(s->handle, CURLOPT_PROXYUSERNAME, userpass->username)) != CURLE_OK)
+		return seterr_curl(s);
+	if ((res = curl_easy_setopt(s->handle, CURLOPT_PROXYPASSWORD, userpass->password)) != CURLE_OK)
+		return seterr_curl(s);
+
+	return 0;
+}
+
+static int ask_and_apply_proxy_creds(curl_stream *s)
+{
+	int error;
+	git_proxy_options *opts = &s->proxy;
+
+	if (!opts->credentials)
+		return error_no_credentials();
+
+	/* TODO: see if PROXYAUTH_AVAIL helps us here */
+	git_cred_free(s->proxy_cred);
+	s->proxy_cred = NULL;
+	giterr_clear();
+	error = opts->credentials(&s->proxy_cred, opts->url, NULL, GIT_CREDTYPE_USERPASS_PLAINTEXT, opts->payload);
+	if (error == GIT_PASSTHROUGH)
+		return error_no_credentials();
+	if (error < 0) {
+		if (!giterr_last())
+			giterr_set(GITERR_NET, "proxy authentication was aborted by the user");
+		return error;
+	}
+
+	if (s->proxy_cred->credtype != GIT_CREDTYPE_USERPASS_PLAINTEXT) {
+		giterr_set(GITERR_NET, "credentials callback returned invalid credential type");
+		return -1;
+	}
+
+	return apply_proxy_creds(s);
+}
+
+static int curls_connect(git_stream *stream)
+{
+	curl_stream *s = (curl_stream *) stream;
+	git_activesocket_t sockextr;
+	long connect_last = 0;
+	int failed_cert = 0, error;
+	bool retry_connect;
+	CURLcode res;
+
+	/* Apply any credentials we've already established */
+	error = apply_proxy_creds(s);
+	if (error < 0 && error != GIT_ENOTFOUND)
+		return seterr_curl(s);
+
+	do {
+		retry_connect = 0;
+		res = curl_easy_perform(s->handle);
+
+		curl_easy_getinfo(s->handle, CURLINFO_HTTP_CONNECTCODE, &connect_last);
+
+		/* HTTP 407 Proxy Authentication Required */
+		if (connect_last == 407) {
+			if ((error = ask_and_apply_proxy_creds(s)) < 0)
+				return error;
+
+			retry_connect = true;
+		}
+	} while (retry_connect);
+
+	if (res != CURLE_OK && res != CURLE_PEER_FAILED_VERIFICATION)
+		return seterr_curl(s);
+	if (res == CURLE_PEER_FAILED_VERIFICATION)
+		failed_cert = 1;
+
+	if ((res = curl_easy_getinfo(s->handle, CURLINFO_ACTIVESOCKET, &sockextr)) != CURLE_OK) {
+		return seterr_curl(s);
+	}
+
+	if (sockextr == GIT_CURL_BADSOCKET) {
+		giterr_set(GITERR_NET, "curl socket is no longer valid");
+		return -1;
+	}
+
+	s->socket = sockextr;
+
+	if (s->parent.encrypted && failed_cert)
+		return GIT_ECERTIFICATE;
+
+	return 0;
+}
+
+static int curls_certificate(git_cert **out, git_stream *stream)
+{
+	int error;
+	CURLcode res;
+	struct curl_slist *slist;
+	struct curl_certinfo *certinfo;
+	git_vector strings = GIT_VECTOR_INIT;
+	curl_stream *s = (curl_stream *) stream;
+
+	if ((res = curl_easy_getinfo(s->handle, CURLINFO_CERTINFO, &certinfo)) != CURLE_OK)
+		return seterr_curl(s);
+
+	/* No information is available, can happen with SecureTransport */
+	if (certinfo->num_of_certs == 0) {
+		s->cert_info.parent.cert_type = GIT_CERT_NONE;
+		s->cert_info.data             = NULL;
+		s->cert_info.len              = 0;
+		return 0;
+	}
+
+	if ((error = git_vector_init(&strings, 8, NULL)) < 0)
+		return error;
+
+	for (slist = certinfo->certinfo[0]; slist; slist = slist->next) {
+		char *str = git__strdup(slist->data);
+		GITERR_CHECK_ALLOC(str);
+		git_vector_insert(&strings, str);
+	}
+
+	/* Copy the contents of the vector into a strarray so we can expose them */
+	s->cert_info_strings.strings = (char **) strings.contents;
+	s->cert_info_strings.count   = strings.length;
+
+	s->cert_info.parent.cert_type = GIT_CERT_STRARRAY;
+	s->cert_info.data             = &s->cert_info_strings;
+	s->cert_info.len              = strings.length;
+
+	*out = &s->cert_info.parent;
+
+	return 0;
+}
+
+static int curls_set_proxy(git_stream *stream, const git_proxy_options *proxy_opts)
+{
+	int error;
+	CURLcode res;
+	curl_stream *s = (curl_stream *) stream;
+
+	git_proxy_options_clear(&s->proxy);
+	if ((error = git_proxy_options_dup(&s->proxy, proxy_opts)) < 0)
+		return error;
+
+	if ((res = curl_easy_setopt(s->handle, CURLOPT_PROXY, s->proxy.url)) != CURLE_OK)
+		return seterr_curl(s);
+
+	if ((res = curl_easy_setopt(s->handle, CURLOPT_PROXYAUTH, CURLAUTH_ANY)) != CURLE_OK)
+		return seterr_curl(s);
+
+	return 0;
+}
+
+static int wait_for(curl_socket_t fd, bool reading)
+{
+	int ret;
+	fd_set infd, outfd, errfd;
+
+	FD_ZERO(&infd);
+	FD_ZERO(&outfd);
+	FD_ZERO(&errfd);
+
+	assert(fd >= 0);
+	FD_SET(fd, &errfd);
+	if (reading)
+		FD_SET(fd, &infd);
+	else
+		FD_SET(fd, &outfd);
+
+	if ((ret = select(fd + 1, &infd, &outfd, &errfd, NULL)) < 0) {
+		giterr_set(GITERR_OS, "error in select");
+		return -1;
+	}
+
+	return 0;
+}
+
+static ssize_t curls_write(git_stream *stream, const char *data, size_t len, int flags)
+{
+	int error;
+	size_t off = 0, sent;
+	CURLcode res;
+	curl_stream *s = (curl_stream *) stream;
+
+	GIT_UNUSED(flags);
+
+	do {
+		if ((error = wait_for(s->socket, false)) < 0)
+			return error;
+
+		res = curl_easy_send(s->handle, data + off, len - off, &sent);
+		if (res == CURLE_OK)
+			off += sent;
+	} while ((res == CURLE_OK || res == CURLE_AGAIN) && off < len);
+
+	if (res != CURLE_OK)
+		return seterr_curl(s);
+
+	return len;
+}
+
+static ssize_t curls_read(git_stream *stream, void *data, size_t len)
+{
+	int error;
+	size_t read;
+	CURLcode res;
+	curl_stream *s = (curl_stream *) stream;
+
+	do {
+		if ((error = wait_for(s->socket, true)) < 0)
+			return error;
+
+		res = curl_easy_recv(s->handle, data, len, &read);
+	} while (res == CURLE_AGAIN);
+
+	if (res != CURLE_OK)
+		return seterr_curl(s);
+
+	return read;
+}
+
+static int curls_close(git_stream *stream)
+{
+	curl_stream *s = (curl_stream *) stream;
+
+	if (!s->handle)
+		return 0;
+
+	curl_easy_cleanup(s->handle);
+	s->handle = NULL;
+	s->socket = 0;
+
+	return 0;
+}
+
+static void curls_free(git_stream *stream)
+{
+	curl_stream *s = (curl_stream *) stream;
+
+	curls_close(stream);
+	git_strarray_free(&s->cert_info_strings);
+	git_proxy_options_clear(&s->proxy);
+	git_cred_free(s->proxy_cred);
+	git__free(s);
+}
+
+int git_curl_stream_new(git_stream **out, const char *host, const char *port)
+{
+	curl_stream *st;
+	CURL *handle;
+	int iport = 0, error;
+
+	st = git__calloc(1, sizeof(curl_stream));
+	GITERR_CHECK_ALLOC(st);
+
+	handle = curl_easy_init();
+	if (handle == NULL) {
+		giterr_set(GITERR_NET, "failed to create curl handle");
+		git__free(st);
+		return -1;
+	}
+
+	if ((error = git__strtol32(&iport, port, NULL, 10)) < 0) {
+		git__free(st);
+		return error;
+	}
+
+	curl_easy_setopt(handle, CURLOPT_URL, host);
+	curl_easy_setopt(handle, CURLOPT_ERRORBUFFER, st->curl_error);
+	curl_easy_setopt(handle, CURLOPT_PORT, iport);
+	curl_easy_setopt(handle, CURLOPT_CONNECT_ONLY, 1);
+	curl_easy_setopt(handle, CURLOPT_SSL_VERIFYPEER, 1);
+	curl_easy_setopt(handle, CURLOPT_CERTINFO, 1);
+	curl_easy_setopt(handle, CURLOPT_HTTPPROXYTUNNEL, 1);
+	curl_easy_setopt(handle, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
+
+	/* curl_easy_setopt(handle, CURLOPT_VERBOSE, 1); */
+
+	st->parent.version = GIT_STREAM_VERSION;
+	st->parent.encrypted = 0; /* we don't encrypt ourselves */
+	st->parent.proxy_support = 1;
+	st->parent.connect = curls_connect;
+	st->parent.certificate = curls_certificate;
+	st->parent.set_proxy = curls_set_proxy;
+	st->parent.read = curls_read;
+	st->parent.write = curls_write;
+	st->parent.close = curls_close;
+	st->parent.free = curls_free;
+	st->handle = handle;
+
+	*out = (git_stream *) st;
+	return 0;
+}
+
+#else
+
+#include "stream.h"
+
+int git_curl_stream_global_init(void)
+{
+	return 0;
+}
+
+int git_curl_stream_new(git_stream **out, const char *host, const char *port)
+{
+	GIT_UNUSED(out);
+	GIT_UNUSED(host);
+	GIT_UNUSED(port);
+
+	giterr_set(GITERR_NET, "curl is not supported in this version");
+	return -1;
+}
+
+
+#endif

vendor/libgit2-sys/libgit2/src/streams/curl.h

diff --git a/vendor/libgit2-sys/libgit2/src/streams/curl.h b/vendor/libgit2-sys/libgit2/src/streams/curl.h
new file mode 100644
index 0000000..511cd89
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/streams/curl.h
@@ -0,0 +1,17 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_streams_curl_h__
+#define INCLUDE_streams_curl_h__
+
+#include "common.h"
+
+#include "git2/sys/stream.h"
+
+extern int git_curl_stream_global_init(void);
+extern int git_curl_stream_new(git_stream **out, const char *host, const char *port);
+
+#endif

vendor/libgit2-sys/libgit2/src/streams/mbedtls.c

diff --git a/vendor/libgit2-sys/libgit2/src/streams/mbedtls.c b/vendor/libgit2-sys/libgit2/src/streams/mbedtls.c
new file mode 100644
index 0000000..0a49a36
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/streams/mbedtls.c
@@ -0,0 +1,452 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "streams/mbedtls.h"
+
+#ifdef GIT_MBEDTLS
+
+#include <ctype.h>
+
+#include "global.h"
+#include "stream.h"
+#include "streams/socket.h"
+#include "netops.h"
+#include "git2/transport.h"
+#include "util.h"
+
+#ifdef GIT_CURL
+# include "streams/curl.h"
+#endif
+
+#ifndef GIT_DEFAULT_CERT_LOCATION
+#define GIT_DEFAULT_CERT_LOCATION NULL
+#endif
+
+#include <mbedtls/config.h>
+#include <mbedtls/ssl.h>
+#include <mbedtls/error.h>
+#include <mbedtls/entropy.h>
+#include <mbedtls/ctr_drbg.h>
+
+mbedtls_ssl_config *git__ssl_conf;
+mbedtls_entropy_context *mbedtls_entropy;
+
+#define GIT_SSL_DEFAULT_CIPHERS "TLS-ECDHE-ECDSA-WITH-AES-128-GCM-SHA256:TLS-ECDHE-RSA-WITH-AES-128-GCM-SHA256:TLS-ECDHE-ECDSA-WITH-AES-256-GCM-SHA384:TLS-ECDHE-RSA-WITH-AES-256-GCM-SHA384:TLS-DHE-RSA-WITH-AES-128-GCM-SHA256:TLS-DHE-DSS-WITH-AES-128-GCM-SHA256:TLS-DHE-RSA-WITH-AES-256-GCM-SHA384:TLS-DHE-DSS-WITH-AES-256-GCM-SHA384:TLS-ECDHE-ECDSA-WITH-AES-128-CBC-SHA256:TLS-ECDHE-RSA-WITH-AES-128-CBC-SHA256:TLS-ECDHE-ECDSA-WITH-AES-128-CBC-SHA:TLS-ECDHE-RSA-WITH-AES-128-CBC-SHA:TLS-ECDHE-ECDSA-WITH-AES-256-CBC-SHA384:TLS-ECDHE-RSA-WITH-AES-256-CBC-SHA384:TLS-ECDHE-ECDSA-WITH-AES-256-CBC-SHA:TLS-ECDHE-RSA-WITH-AES-256-CBC-SHA:TLS-DHE-RSA-WITH-AES-128-CBC-SHA256:TLS-DHE-RSA-WITH-AES-256-CBC-SHA256:TLS-DHE-RSA-WITH-AES-128-CBC-SHA:TLS-DHE-RSA-WITH-AES-256-CBC-SHA:TLS-DHE-DSS-WITH-AES-128-CBC-SHA256:TLS-DHE-DSS-WITH-AES-256-CBC-SHA256:TLS-DHE-DSS-WITH-AES-128-CBC-SHA:TLS-DHE-DSS-WITH-AES-256-CBC-SHA:TLS-RSA-WITH-AES-128-GCM-SHA256:TLS-RSA-WITH-AES-256-GCM-SHA384:TLS-RSA-WITH-AES-128-CBC-SHA256:TLS-RSA-WITH-AES-256-CBC-SHA256:TLS-RSA-WITH-AES-128-CBC-SHA:TLS-RSA-WITH-AES-256-CBC-SHA"
+#define GIT_SSL_DEFAULT_CIPHERS_COUNT 30
+
+/**
+ * This function aims to clean-up the SSL context which
+ * we allocated.
+ */
+static void shutdown_ssl(void)
+{
+	if (git__ssl_conf) {
+		mbedtls_x509_crt_free(git__ssl_conf->ca_chain);
+		git__free(git__ssl_conf->ca_chain);
+		mbedtls_ctr_drbg_free(git__ssl_conf->p_rng);
+		git__free(git__ssl_conf->p_rng);
+		mbedtls_ssl_config_free(git__ssl_conf);
+		git__free(git__ssl_conf);
+		git__ssl_conf = NULL;
+	}
+	if (mbedtls_entropy) {
+		mbedtls_entropy_free(mbedtls_entropy);
+		git__free(mbedtls_entropy);
+		mbedtls_entropy = NULL;
+	}
+}
+
+int git_mbedtls__set_cert_location(const char *path, int is_dir);
+
+int git_mbedtls_stream_global_init(void)
+{
+	int loaded = 0;
+	char *crtpath = GIT_DEFAULT_CERT_LOCATION;
+	struct stat statbuf;
+	mbedtls_ctr_drbg_context *ctr_drbg = NULL;
+
+	int *ciphers_list = NULL;
+	int ciphers_known = 0;
+	char *cipher_name = NULL;
+	char *cipher_string = NULL;
+	char *cipher_string_tmp = NULL;
+
+	mbedtls_x509_crt *cacert = NULL;
+
+	git__ssl_conf = git__malloc(sizeof(mbedtls_ssl_config));
+	mbedtls_ssl_config_init(git__ssl_conf);
+	if (mbedtls_ssl_config_defaults(git__ssl_conf,
+		                            MBEDTLS_SSL_IS_CLIENT,
+		                            MBEDTLS_SSL_TRANSPORT_STREAM,
+		                            MBEDTLS_SSL_PRESET_DEFAULT) != 0) {
+		giterr_set(GITERR_SSL, "failed to initialize mbedTLS");
+		goto cleanup;
+	}
+
+	/* configure TLSv1 */
+	mbedtls_ssl_conf_min_version(git__ssl_conf, MBEDTLS_SSL_MAJOR_VERSION_3, MBEDTLS_SSL_MINOR_VERSION_0);
+
+	/* verify_server_cert is responsible for making the check.
+	 * OPTIONAL because REQUIRED drops the certificate as soon as the check
+	 * is made, so we can never see the certificate and override it. */
+	mbedtls_ssl_conf_authmode(git__ssl_conf, MBEDTLS_SSL_VERIFY_OPTIONAL);
+
+	/* set the list of allowed ciphersuites */
+	ciphers_list = calloc(GIT_SSL_DEFAULT_CIPHERS_COUNT, sizeof(int));
+	ciphers_known = 0;
+	cipher_string = cipher_string_tmp = git__strdup(GIT_SSL_DEFAULT_CIPHERS);
+	while ((cipher_name = git__strtok(&cipher_string_tmp, ":")) != NULL) {
+		int cipherid = mbedtls_ssl_get_ciphersuite_id(cipher_name);
+		if (cipherid == 0) continue;
+
+		ciphers_list[ciphers_known++] = cipherid;
+	}
+	git__free(cipher_string);
+
+	if (!ciphers_known) {
+		giterr_set(GITERR_SSL, "no cipher could be enabled");
+		goto cleanup;
+	}
+	mbedtls_ssl_conf_ciphersuites(git__ssl_conf, ciphers_list);
+
+	/* Seeding the random number generator */
+	mbedtls_entropy = git__malloc(sizeof(mbedtls_entropy_context));
+	mbedtls_entropy_init(mbedtls_entropy);
+
+	ctr_drbg = git__malloc(sizeof(mbedtls_ctr_drbg_context));
+	mbedtls_ctr_drbg_init(ctr_drbg);
+	if (mbedtls_ctr_drbg_seed(ctr_drbg,
+		                      mbedtls_entropy_func,
+		                      mbedtls_entropy, NULL, 0) != 0) {
+		giterr_set(GITERR_SSL, "failed to initialize mbedTLS entropy pool");
+		goto cleanup;
+	}
+
+	mbedtls_ssl_conf_rng(git__ssl_conf, mbedtls_ctr_drbg_random, ctr_drbg);
+
+	/* load default certificates */
+	if (crtpath != NULL && stat(crtpath, &statbuf) == 0 && S_ISREG(statbuf.st_mode))
+		loaded = (git_mbedtls__set_cert_location(crtpath, 0) == 0);
+	if (!loaded && crtpath != NULL && stat(crtpath, &statbuf) == 0 && S_ISDIR(statbuf.st_mode))
+		loaded = (git_mbedtls__set_cert_location(crtpath, 1) == 0);
+
+	git__on_shutdown(shutdown_ssl);
+
+	return 0;
+
+cleanup:
+	mbedtls_x509_crt_free(cacert);
+	git__free(cacert);
+	mbedtls_ctr_drbg_free(ctr_drbg);
+	git__free(ctr_drbg);
+	mbedtls_ssl_config_free(git__ssl_conf);
+	git__free(git__ssl_conf);
+	git__ssl_conf = NULL;
+
+	return -1;
+}
+
+mbedtls_ssl_config *git__ssl_conf;
+
+static int bio_read(void *b, unsigned char *buf, size_t len)
+{
+	git_stream *io = (git_stream *) b;
+	return (int) git_stream_read(io, buf, len);
+}
+
+static int bio_write(void *b, const unsigned char *buf, size_t len)
+{
+	git_stream *io = (git_stream *) b;
+	return (int) git_stream_write(io, (const char *)buf, len, 0);
+}
+
+static int ssl_set_error(mbedtls_ssl_context *ssl, int error)
+{
+	char errbuf[512];
+	int ret = -1;
+
+	assert(error != MBEDTLS_ERR_SSL_WANT_READ);
+	assert(error != MBEDTLS_ERR_SSL_WANT_WRITE);
+
+	if (error != 0)
+		mbedtls_strerror( error, errbuf, 512 );
+
+	switch(error) {
+		case 0:
+		giterr_set(GITERR_SSL, "SSL error: unknown error");
+		break;
+
+	case MBEDTLS_ERR_X509_CERT_VERIFY_FAILED:
+		giterr_set(GITERR_SSL, "SSL error: %#04x [%x] - %s", error, ssl->session_negotiate->verify_result, errbuf);
+		ret = GIT_ECERTIFICATE;
+		break;
+
+	default:
+		giterr_set(GITERR_SSL, "SSL error: %#04x - %s", error, errbuf);
+	}
+
+	return ret;
+}
+
+static int ssl_teardown(mbedtls_ssl_context *ssl)
+{
+	int ret = 0;
+
+	ret = mbedtls_ssl_close_notify(ssl);
+	if (ret < 0)
+		ret = ssl_set_error(ssl, ret);
+
+	mbedtls_ssl_free(ssl);
+	return ret;
+}
+
+static int verify_server_cert(mbedtls_ssl_context *ssl)
+{
+	int ret = -1;
+
+	if ((ret = mbedtls_ssl_get_verify_result(ssl)) != 0) {
+		char vrfy_buf[512];
+		int len = mbedtls_x509_crt_verify_info(vrfy_buf, sizeof(vrfy_buf), "", ret);
+		if (len >= 1) vrfy_buf[len - 1] = '\0'; /* Remove trailing \n */
+		giterr_set(GITERR_SSL, "the SSL certificate is invalid: %#04x - %s", ret, vrfy_buf);
+		return GIT_ECERTIFICATE;
+	}
+
+	return 0;
+}
+
+typedef struct {
+	git_stream parent;
+	git_stream *io;
+	bool connected;
+	char *host;
+	mbedtls_ssl_context *ssl;
+	git_cert_x509 cert_info;
+} mbedtls_stream;
+
+
+int mbedtls_connect(git_stream *stream)
+{
+	int ret;
+	mbedtls_stream *st = (mbedtls_stream *) stream;
+
+	if ((ret = git_stream_connect(st->io)) < 0)
+		return ret;
+
+	st->connected = true;
+
+	mbedtls_ssl_set_hostname(st->ssl, st->host);
+
+	mbedtls_ssl_set_bio(st->ssl, st->io, bio_write, bio_read, NULL);
+
+	if ((ret = mbedtls_ssl_handshake(st->ssl)) != 0)
+		return ssl_set_error(st->ssl, ret);
+
+	return verify_server_cert(st->ssl);
+}
+
+int mbedtls_certificate(git_cert **out, git_stream *stream)
+{
+	unsigned char *encoded_cert;
+	mbedtls_stream *st = (mbedtls_stream *) stream;
+
+	const mbedtls_x509_crt *cert = mbedtls_ssl_get_peer_cert(st->ssl);
+	if (!cert) {
+		giterr_set(GITERR_SSL, "the server did not provide a certificate");
+		return -1;
+	}
+
+	/* Retrieve the length of the certificate first */
+	if (cert->raw.len == 0) {
+		giterr_set(GITERR_NET, "failed to retrieve certificate information");
+		return -1;
+	}
+
+	encoded_cert = git__malloc(cert->raw.len);
+	GITERR_CHECK_ALLOC(encoded_cert);
+	memcpy(encoded_cert, cert->raw.p, cert->raw.len);
+
+	st->cert_info.parent.cert_type = GIT_CERT_X509;
+	st->cert_info.data = encoded_cert;
+	st->cert_info.len = cert->raw.len;
+
+	*out = &st->cert_info.parent;
+
+	return 0;
+}
+
+static int mbedtls_set_proxy(git_stream *stream, const git_proxy_options *proxy_options)
+{
+	mbedtls_stream *st = (mbedtls_stream *) stream;
+
+	return git_stream_set_proxy(st->io, proxy_options);
+}
+
+ssize_t mbedtls_stream_write(git_stream *stream, const char *data, size_t len, int flags)
+{
+	size_t read = 0;
+	mbedtls_stream *st = (mbedtls_stream *) stream;
+
+	GIT_UNUSED(flags);
+
+	do {
+		int error = mbedtls_ssl_write(st->ssl, (const unsigned char *)data + read, len - read);
+		if (error <= 0) {
+			return ssl_set_error(st->ssl, error);
+		}
+		read += error;
+	} while (read < len);
+
+	return read;
+}
+
+ssize_t mbedtls_stream_read(git_stream *stream, void *data, size_t len)
+{
+	mbedtls_stream *st = (mbedtls_stream *) stream;
+	int ret;
+
+	if ((ret = mbedtls_ssl_read(st->ssl, (unsigned char *)data, len)) <= 0)
+		ssl_set_error(st->ssl, ret);
+
+	return ret;
+}
+
+int mbedtls_stream_close(git_stream *stream)
+{
+	mbedtls_stream *st = (mbedtls_stream *) stream;
+	int ret = 0;
+
+	if (st->connected && (ret = ssl_teardown(st->ssl)) != 0)
+		return -1;
+
+	st->connected = false;
+
+	return git_stream_close(st->io);
+}
+
+void mbedtls_stream_free(git_stream *stream)
+{
+	mbedtls_stream *st = (mbedtls_stream *) stream;
+
+	git__free(st->host);
+	git__free(st->cert_info.data);
+	git_stream_free(st->io);
+	git__free(st->ssl);
+	git__free(st);
+}
+
+int git_mbedtls_stream_new(git_stream **out, const char *host, const char *port)
+{
+	int error;
+	mbedtls_stream *st;
+
+	st = git__calloc(1, sizeof(mbedtls_stream));
+	GITERR_CHECK_ALLOC(st);
+
+#ifdef GIT_CURL
+	error = git_curl_stream_new(&st->io, host, port);
+#else
+	error = git_socket_stream_new(&st->io, host, port);
+#endif
+
+	if (error < 0)
+		goto out_err;
+
+	st->ssl = git__malloc(sizeof(mbedtls_ssl_context));
+	GITERR_CHECK_ALLOC(st->ssl);
+	mbedtls_ssl_init(st->ssl);
+	if (mbedtls_ssl_setup(st->ssl, git__ssl_conf)) {
+		giterr_set(GITERR_SSL, "failed to create ssl object");
+		error = -1;
+		goto out_err;
+	}
+
+	st->host = git__strdup(host);
+	GITERR_CHECK_ALLOC(st->host);
+
+	st->parent.version = GIT_STREAM_VERSION;
+	st->parent.encrypted = 1;
+	st->parent.proxy_support = git_stream_supports_proxy(st->io);
+	st->parent.connect = mbedtls_connect;
+	st->parent.certificate = mbedtls_certificate;
+	st->parent.set_proxy = mbedtls_set_proxy;
+	st->parent.read = mbedtls_stream_read;
+	st->parent.write = mbedtls_stream_write;
+	st->parent.close = mbedtls_stream_close;
+	st->parent.free = mbedtls_stream_free;
+
+	*out = (git_stream *) st;
+	return 0;
+
+out_err:
+	mbedtls_ssl_free(st->ssl);
+	git_stream_free(st->io);
+	git__free(st);
+
+	return error;
+}
+
+int git_mbedtls__set_cert_location(const char *path, int is_dir)
+{
+	int ret = 0;
+	char errbuf[512];
+	mbedtls_x509_crt *cacert;
+
+	assert(path != NULL);
+
+	cacert = git__malloc(sizeof(mbedtls_x509_crt));
+	mbedtls_x509_crt_init(cacert);
+	if (is_dir) {
+		ret = mbedtls_x509_crt_parse_path(cacert, path);
+	} else {
+		ret = mbedtls_x509_crt_parse_file(cacert, path);
+	}
+	/* mbedtls_x509_crt_parse_path returns the number of invalid certs on success */
+	if (ret < 0) {
+		mbedtls_x509_crt_free(cacert);
+		git__free(cacert);
+		mbedtls_strerror( ret, errbuf, 512 );
+		giterr_set(GITERR_SSL, "failed to load CA certificates: %#04x - %s", ret, errbuf);
+		return -1;
+	}
+
+	mbedtls_x509_crt_free(git__ssl_conf->ca_chain);
+	git__free(git__ssl_conf->ca_chain);
+	mbedtls_ssl_conf_ca_chain(git__ssl_conf, cacert, NULL);
+
+	return 0;
+}
+
+#else
+
+#include "stream.h"
+
+int git_mbedtls_stream_global_init(void)
+{
+	return 0;
+}
+
+int git_mbedtls_stream_new(git_stream **out, const char *host, const char *port)
+{
+	GIT_UNUSED(out);
+	GIT_UNUSED(host);
+	GIT_UNUSED(port);
+
+	giterr_set(GITERR_SSL, "mbedTLS is not supported in this version");
+	return -1;
+}
+
+int git_mbedtls__set_cert_location(const char *path, int is_dir)
+{
+	GIT_UNUSED(path);
+	GIT_UNUSED(is_dir);
+
+	giterr_set(GITERR_SSL, "mbedTLS is not supported in this version");
+	return -1;
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/streams/mbedtls.h

diff --git a/vendor/libgit2-sys/libgit2/src/streams/mbedtls.h b/vendor/libgit2-sys/libgit2/src/streams/mbedtls.h
new file mode 100644
index 0000000..7283698
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/streams/mbedtls.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_steams_mbedtls_h__
+#define INCLUDE_steams_mbedtls_h__
+
+#include "common.h"
+
+#include "git2/sys/stream.h"
+
+extern int git_mbedtls_stream_global_init(void);
+
+extern int git_mbedtls_stream_new(git_stream **out, const char *host, const char *port);
+
+extern int git_mbedtls__set_cert_location(const char *path, int is_dir);
+
+#endif

vendor/libgit2-sys/libgit2/src/streams/openssl.c

diff --git a/vendor/libgit2-sys/libgit2/src/streams/openssl.c b/vendor/libgit2-sys/libgit2/src/streams/openssl.c
new file mode 100644
index 0000000..103e45f
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/streams/openssl.c
@@ -0,0 +1,798 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "streams/openssl.h"
+
+#ifdef GIT_OPENSSL
+
+#include <ctype.h>
+
+#include "global.h"
+#include "posix.h"
+#include "stream.h"
+#include "streams/socket.h"
+#include "netops.h"
+#include "git2/transport.h"
+#include "git2/sys/openssl.h"
+
+#ifdef GIT_CURL
+# include "streams/curl.h"
+#endif
+
+#ifndef GIT_WIN32
+# include <sys/types.h>
+# include <sys/socket.h>
+# include <netinet/in.h>
+#endif
+
+#include <openssl/ssl.h>
+#include <openssl/err.h>
+#include <openssl/x509v3.h>
+#include <openssl/bio.h>
+
+SSL_CTX *git__ssl_ctx;
+
+#define GIT_SSL_DEFAULT_CIPHERS "ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:DHE-DSS-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA:DHE-DSS-AES128-SHA256:DHE-DSS-AES256-SHA256:DHE-DSS-AES128-SHA:DHE-DSS-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA"
+
+#if (defined(OPENSSL_VERSION_NUMBER) && OPENSSL_VERSION_NUMBER < 0x10100000L) || \
+     (defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER < 0x20700000L)
+# define OPENSSL_LEGACY_API
+#endif
+
+/*
+ * OpenSSL 1.1 made BIO opaque so we have to use functions to interact with it
+ * which do not exist in previous versions. We define these inline functions so
+ * we can program against the interface instead of littering the implementation
+ * with ifdefs. We do the same for OPENSSL_init_ssl.
+ */
+#if defined(OPENSSL_LEGACY_API)
+static int OPENSSL_init_ssl(int opts, void *settings)
+{
+	GIT_UNUSED(opts);
+	GIT_UNUSED(settings);
+	SSL_load_error_strings();
+	OpenSSL_add_ssl_algorithms();
+	return 0;
+}
+
+static BIO_METHOD* BIO_meth_new(int type, const char *name)
+{
+	BIO_METHOD *meth = git__calloc(1, sizeof(BIO_METHOD));
+	if (!meth) {
+		return NULL;
+	}
+
+	meth->type = type;
+	meth->name = name;
+
+	return meth;
+}
+
+static void BIO_meth_free(BIO_METHOD *biom)
+{
+	git__free(biom);
+}
+
+static int BIO_meth_set_write(BIO_METHOD *biom, int (*write) (BIO *, const char *, int))
+{
+	biom->bwrite = write;
+	return 1;
+}
+
+static int BIO_meth_set_read(BIO_METHOD *biom, int (*read) (BIO *, char *, int))
+{
+	biom->bread = read;
+	return 1;
+}
+
+static int BIO_meth_set_puts(BIO_METHOD *biom, int (*puts) (BIO *, const char *))
+{
+	biom->bputs = puts;
+	return 1;
+}
+
+static int BIO_meth_set_gets(BIO_METHOD *biom, int (*gets) (BIO *, char *, int))
+
+{
+	biom->bgets = gets;
+	return 1;
+}
+
+static int BIO_meth_set_ctrl(BIO_METHOD *biom, long (*ctrl) (BIO *, int, long, void *))
+{
+	biom->ctrl = ctrl;
+	return 1;
+}
+
+static int BIO_meth_set_create(BIO_METHOD *biom, int (*create) (BIO *))
+{
+	biom->create = create;
+	return 1;
+}
+
+static int BIO_meth_set_destroy(BIO_METHOD *biom, int (*destroy) (BIO *))
+{
+	biom->destroy = destroy;
+	return 1;
+}
+
+static int BIO_get_new_index(void)
+{
+	/* This exists as of 1.1 so before we'd just have 0 */
+	return 0;
+}
+
+static void BIO_set_init(BIO *b, int init)
+{
+	b->init = init;
+}
+
+static void BIO_set_data(BIO *a, void *ptr)
+{
+	a->ptr = ptr;
+}
+
+static void *BIO_get_data(BIO *a)
+{
+	return a->ptr;
+}
+
+static const unsigned char *ASN1_STRING_get0_data(const ASN1_STRING *x)
+{
+	return ASN1_STRING_data((ASN1_STRING *)x);
+}
+
+# if defined(GIT_THREADS)
+static git_mutex *openssl_locks;
+
+static void openssl_locking_function(
+	int mode, int n, const char *file, int line)
+{
+	int lock;
+
+	GIT_UNUSED(file);
+	GIT_UNUSED(line);
+
+	lock = mode & CRYPTO_LOCK;
+
+	if (lock) {
+		git_mutex_lock(&openssl_locks[n]);
+	} else {
+		git_mutex_unlock(&openssl_locks[n]);
+	}
+}
+
+static void shutdown_ssl_locking(void)
+{
+	int num_locks, i;
+
+	num_locks = CRYPTO_num_locks();
+	CRYPTO_set_locking_callback(NULL);
+
+	for (i = 0; i < num_locks; ++i)
+		git_mutex_free(&openssl_locks[i]);
+	git__free(openssl_locks);
+}
+# endif /* GIT_THREADS */
+#endif /* OPENSSL_LEGACY_API */
+
+static BIO_METHOD *git_stream_bio_method;
+static int init_bio_method(void);
+
+/**
+ * This function aims to clean-up the SSL context which
+ * we allocated.
+ */
+static void shutdown_ssl(void)
+{
+	if (git_stream_bio_method) {
+		BIO_meth_free(git_stream_bio_method);
+		git_stream_bio_method = NULL;
+	}
+
+	if (git__ssl_ctx) {
+		SSL_CTX_free(git__ssl_ctx);
+		git__ssl_ctx = NULL;
+	}
+}
+
+int git_openssl_stream_global_init(void)
+{
+	long ssl_opts = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3;
+	const char *ciphers = git_libgit2__ssl_ciphers();
+
+	/* Older OpenSSL and MacOS OpenSSL doesn't have this */
+#ifdef SSL_OP_NO_COMPRESSION
+	ssl_opts |= SSL_OP_NO_COMPRESSION;
+#endif
+
+	OPENSSL_init_ssl(0, NULL);
+
+	/*
+	 * Load SSLv{2,3} and TLSv1 so that we can talk with servers
+	 * which use the SSL hellos, which are often used for
+	 * compatibility. We then disable SSL so we only allow OpenSSL
+	 * to speak TLSv1 to perform the encryption itself.
+	 */
+	git__ssl_ctx = SSL_CTX_new(SSLv23_method());
+	SSL_CTX_set_options(git__ssl_ctx, ssl_opts);
+	SSL_CTX_set_mode(git__ssl_ctx, SSL_MODE_AUTO_RETRY);
+	SSL_CTX_set_verify(git__ssl_ctx, SSL_VERIFY_NONE, NULL);
+	if (!SSL_CTX_set_default_verify_paths(git__ssl_ctx)) {
+		SSL_CTX_free(git__ssl_ctx);
+		git__ssl_ctx = NULL;
+		return -1;
+	}
+
+	if (!ciphers) {
+		ciphers = GIT_SSL_DEFAULT_CIPHERS;
+	}
+
+	if(!SSL_CTX_set_cipher_list(git__ssl_ctx, ciphers)) {
+		SSL_CTX_free(git__ssl_ctx);
+		git__ssl_ctx = NULL;
+		return -1;
+	}
+
+	if (init_bio_method() < 0) {
+		SSL_CTX_free(git__ssl_ctx);
+		git__ssl_ctx = NULL;
+		return -1;
+	}
+
+	git__on_shutdown(shutdown_ssl);
+
+	return 0;
+}
+
+#if defined(GIT_THREADS) && defined(OPENSSL_LEGACY_API)
+static void threadid_cb(CRYPTO_THREADID *threadid)
+{
+	GIT_UNUSED(threadid);
+	CRYPTO_THREADID_set_numeric(threadid, git_thread_currentid());
+}
+#endif
+
+int git_openssl_set_locking(void)
+{
+#if defined(GIT_THREADS) && defined(OPENSSL_LEGACY_API)
+	int num_locks, i;
+
+	CRYPTO_THREADID_set_callback(threadid_cb);
+
+	num_locks = CRYPTO_num_locks();
+	openssl_locks = git__calloc(num_locks, sizeof(git_mutex));
+	GITERR_CHECK_ALLOC(openssl_locks);
+
+	for (i = 0; i < num_locks; i++) {
+		if (git_mutex_init(&openssl_locks[i]) != 0) {
+			giterr_set(GITERR_SSL, "failed to initialize openssl locks");
+			return -1;
+		}
+	}
+
+	CRYPTO_set_locking_callback(openssl_locking_function);
+	git__on_shutdown(shutdown_ssl_locking);
+	return 0;
+#elif !defined(OPENSSL_LEGACY_API)
+	return 0;
+#else
+	giterr_set(GITERR_THREAD, "libgit2 was not built with threads");
+	return -1;
+#endif
+}
+
+
+static int bio_create(BIO *b)
+{
+	BIO_set_init(b, 1);
+	BIO_set_data(b, NULL);
+
+	return 1;
+}
+
+static int bio_destroy(BIO *b)
+{
+	if (!b)
+		return 0;
+
+	BIO_set_data(b, NULL);
+
+	return 1;
+}
+
+static int bio_read(BIO *b, char *buf, int len)
+{
+	git_stream *io = (git_stream *) BIO_get_data(b);
+
+	return (int) git_stream_read(io, buf, len);
+}
+
+static int bio_write(BIO *b, const char *buf, int len)
+{
+	git_stream *io = (git_stream *) BIO_get_data(b);
+
+	return (int) git_stream_write(io, buf, len, 0);
+}
+
+static long bio_ctrl(BIO *b, int cmd, long num, void *ptr)
+{
+	GIT_UNUSED(b);
+	GIT_UNUSED(num);
+	GIT_UNUSED(ptr);
+
+	if (cmd == BIO_CTRL_FLUSH)
+		return 1;
+
+	return 0;
+}
+
+static int bio_gets(BIO *b, char *buf, int len)
+{
+	GIT_UNUSED(b);
+	GIT_UNUSED(buf);
+	GIT_UNUSED(len);
+	return -1;
+}
+
+static int bio_puts(BIO *b, const char *str)
+{
+	return bio_write(b, str, strlen(str));
+}
+
+static int init_bio_method(void)
+{
+	/* Set up the BIO_METHOD we use for wrapping our own stream implementations */
+	git_stream_bio_method = BIO_meth_new(BIO_TYPE_SOURCE_SINK | BIO_get_new_index(), "git_stream");
+	GITERR_CHECK_ALLOC(git_stream_bio_method);
+
+	BIO_meth_set_write(git_stream_bio_method, bio_write);
+	BIO_meth_set_read(git_stream_bio_method, bio_read);
+	BIO_meth_set_puts(git_stream_bio_method, bio_puts);
+	BIO_meth_set_gets(git_stream_bio_method, bio_gets);
+	BIO_meth_set_ctrl(git_stream_bio_method, bio_ctrl);
+	BIO_meth_set_create(git_stream_bio_method, bio_create);
+	BIO_meth_set_destroy(git_stream_bio_method, bio_destroy);
+
+	return 0;
+}
+
+static int ssl_set_error(SSL *ssl, int error)
+{
+	int err;
+	unsigned long e;
+
+	err = SSL_get_error(ssl, error);
+
+	assert(err != SSL_ERROR_WANT_READ);
+	assert(err != SSL_ERROR_WANT_WRITE);
+
+	switch (err) {
+	case SSL_ERROR_WANT_CONNECT:
+	case SSL_ERROR_WANT_ACCEPT:
+		giterr_set(GITERR_NET, "SSL error: connection failure");
+		break;
+	case SSL_ERROR_WANT_X509_LOOKUP:
+		giterr_set(GITERR_NET, "SSL error: x509 error");
+		break;
+	case SSL_ERROR_SYSCALL:
+		e = ERR_get_error();
+		if (e > 0) {
+			char errmsg[256];
+			ERR_error_string_n(e, errmsg, sizeof(errmsg));
+			giterr_set(GITERR_NET, "SSL error: %s", errmsg);
+			break;
+		} else if (error < 0) {
+			giterr_set(GITERR_OS, "SSL error: syscall failure");
+			break;
+		}
+		giterr_set(GITERR_NET, "SSL error: received early EOF");
+		return GIT_EEOF;
+		break;
+	case SSL_ERROR_SSL:
+	{
+		char errmsg[256];
+		e = ERR_get_error();
+		ERR_error_string_n(e, errmsg, sizeof(errmsg));
+		giterr_set(GITERR_NET, "SSL error: %s", errmsg);
+		break;
+	}
+	case SSL_ERROR_NONE:
+	case SSL_ERROR_ZERO_RETURN:
+	default:
+		giterr_set(GITERR_NET, "SSL error: unknown error");
+		break;
+	}
+	return -1;
+}
+
+static int ssl_teardown(SSL *ssl)
+{
+	int ret;
+
+	ret = SSL_shutdown(ssl);
+	if (ret < 0)
+		ret = ssl_set_error(ssl, ret);
+	else
+		ret = 0;
+
+	return ret;
+}
+
+static int check_host_name(const char *name, const char *host)
+{
+	if (!strcasecmp(name, host))
+		return 0;
+
+	if (gitno__match_host(name, host) < 0)
+		return -1;
+
+	return 0;
+}
+
+static int verify_server_cert(SSL *ssl, const char *host)
+{
+	X509 *cert = NULL;
+	X509_NAME *peer_name;
+	ASN1_STRING *str;
+	unsigned char *peer_cn = NULL;
+	int matched = -1, type = GEN_DNS;
+	GENERAL_NAMES *alts;
+	struct in6_addr addr6;
+	struct in_addr addr4;
+	void *addr = NULL;
+	int i = -1, j, error = 0;
+
+	if (SSL_get_verify_result(ssl) != X509_V_OK) {
+		giterr_set(GITERR_SSL, "the SSL certificate is invalid");
+		return GIT_ECERTIFICATE;
+	}
+
+	/* Try to parse the host as an IP address to see if it is */
+	if (p_inet_pton(AF_INET, host, &addr4)) {
+		type = GEN_IPADD;
+		addr = &addr4;
+	} else {
+		if (p_inet_pton(AF_INET6, host, &addr6)) {
+			type = GEN_IPADD;
+			addr = &addr6;
+		}
+	}
+
+
+	cert = SSL_get_peer_certificate(ssl);
+	if (!cert) {
+		error = -1;
+		giterr_set(GITERR_SSL, "the server did not provide a certificate");
+		goto cleanup;
+	}
+
+	/* Check the alternative names */
+	alts = X509_get_ext_d2i(cert, NID_subject_alt_name, NULL, NULL);
+	if (alts) {
+		int num;
+
+		num = sk_GENERAL_NAME_num(alts);
+		for (i = 0; i < num && matched != 1; i++) {
+			const GENERAL_NAME *gn = sk_GENERAL_NAME_value(alts, i);
+			const char *name = (char *) ASN1_STRING_get0_data(gn->d.ia5);
+			size_t namelen = (size_t) ASN1_STRING_length(gn->d.ia5);
+
+			/* Skip any names of a type we're not looking for */
+			if (gn->type != type)
+				continue;
+
+			if (type == GEN_DNS) {
+				/* If it contains embedded NULs, don't even try */
+				if (memchr(name, '\0', namelen))
+					continue;
+
+				if (check_host_name(name, host) < 0)
+					matched = 0;
+				else
+					matched = 1;
+			} else if (type == GEN_IPADD) {
+				/* Here name isn't so much a name but a binary representation of the IP */
+				matched = addr && !!memcmp(name, addr, namelen);
+			}
+		}
+	}
+	GENERAL_NAMES_free(alts);
+
+	if (matched == 0)
+		goto cert_fail_name;
+
+	if (matched == 1) {
+		goto cleanup;
+	}
+
+	/* If no alternative names are available, check the common name */
+	peer_name = X509_get_subject_name(cert);
+	if (peer_name == NULL)
+		goto on_error;
+
+	if (peer_name) {
+		/* Get the index of the last CN entry */
+		while ((j = X509_NAME_get_index_by_NID(peer_name, NID_commonName, i)) >= 0)
+			i = j;
+	}
+
+	if (i < 0)
+		goto on_error;
+
+	str = X509_NAME_ENTRY_get_data(X509_NAME_get_entry(peer_name, i));
+	if (str == NULL)
+		goto on_error;
+
+	/* Work around a bug in OpenSSL whereby ASN1_STRING_to_UTF8 fails if it's already in utf-8 */
+	if (ASN1_STRING_type(str) == V_ASN1_UTF8STRING) {
+		int size = ASN1_STRING_length(str);
+
+		if (size > 0) {
+			peer_cn = OPENSSL_malloc(size + 1);
+			GITERR_CHECK_ALLOC(peer_cn);
+			memcpy(peer_cn, ASN1_STRING_get0_data(str), size);
+			peer_cn[size] = '\0';
+		} else {
+			goto cert_fail_name;
+		}
+	} else {
+		int size = ASN1_STRING_to_UTF8(&peer_cn, str);
+		GITERR_CHECK_ALLOC(peer_cn);
+		if (memchr(peer_cn, '\0', size))
+			goto cert_fail_name;
+	}
+
+	if (check_host_name((char *)peer_cn, host) < 0)
+		goto cert_fail_name;
+
+	goto cleanup;
+
+cert_fail_name:
+	error = GIT_ECERTIFICATE;
+	giterr_set(GITERR_SSL, "hostname does not match certificate");
+	goto cleanup;
+
+on_error:
+	error = ssl_set_error(ssl, 0);
+	goto cleanup;
+
+cleanup:
+	X509_free(cert);
+	OPENSSL_free(peer_cn);
+	return error;
+}
+
+typedef struct {
+	git_stream parent;
+	git_stream *io;
+	bool connected;
+	char *host;
+	SSL *ssl;
+	git_cert_x509 cert_info;
+} openssl_stream;
+
+int openssl_close(git_stream *stream);
+
+int openssl_connect(git_stream *stream)
+{
+	int ret;
+	BIO *bio;
+	openssl_stream *st = (openssl_stream *) stream;
+
+	if ((ret = git_stream_connect(st->io)) < 0)
+		return ret;
+
+	st->connected = true;
+
+	bio = BIO_new(git_stream_bio_method);
+	GITERR_CHECK_ALLOC(bio);
+
+	BIO_set_data(bio, st->io);
+	SSL_set_bio(st->ssl, bio, bio);
+
+	/* specify the host in case SNI is needed */
+#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
+	SSL_set_tlsext_host_name(st->ssl, st->host);
+#endif
+
+	if ((ret = SSL_connect(st->ssl)) <= 0)
+		return ssl_set_error(st->ssl, ret);
+
+	return verify_server_cert(st->ssl, st->host);
+}
+
+int openssl_certificate(git_cert **out, git_stream *stream)
+{
+	openssl_stream *st = (openssl_stream *) stream;
+	int len;
+	X509 *cert = SSL_get_peer_certificate(st->ssl);
+	unsigned char *guard, *encoded_cert;
+
+	/* Retrieve the length of the certificate first */
+	len = i2d_X509(cert, NULL);
+	if (len < 0) {
+		giterr_set(GITERR_NET, "failed to retrieve certificate information");
+		return -1;
+	}
+
+	encoded_cert = git__malloc(len);
+	GITERR_CHECK_ALLOC(encoded_cert);
+	/* i2d_X509 makes 'guard' point to just after the data */
+	guard = encoded_cert;
+
+	len = i2d_X509(cert, &guard);
+	if (len < 0) {
+		git__free(encoded_cert);
+		giterr_set(GITERR_NET, "failed to retrieve certificate information");
+		return -1;
+	}
+
+	st->cert_info.parent.cert_type = GIT_CERT_X509;
+	st->cert_info.data = encoded_cert;
+	st->cert_info.len = len;
+
+	*out = &st->cert_info.parent;
+
+	return 0;
+}
+
+static int openssl_set_proxy(git_stream *stream, const git_proxy_options *proxy_opts)
+{
+	openssl_stream *st = (openssl_stream *) stream;
+
+	return git_stream_set_proxy(st->io, proxy_opts);
+}
+
+ssize_t openssl_write(git_stream *stream, const char *data, size_t len, int flags)
+{
+	openssl_stream *st = (openssl_stream *) stream;
+	int ret;
+
+	GIT_UNUSED(flags);
+
+	if ((ret = SSL_write(st->ssl, data, len)) <= 0) {
+		return ssl_set_error(st->ssl, ret);
+	}
+
+	return ret;
+}
+
+ssize_t openssl_read(git_stream *stream, void *data, size_t len)
+{
+	openssl_stream *st = (openssl_stream *) stream;
+	int ret;
+
+	if ((ret = SSL_read(st->ssl, data, len)) <= 0)
+		return ssl_set_error(st->ssl, ret);
+
+	return ret;
+}
+
+int openssl_close(git_stream *stream)
+{
+	openssl_stream *st = (openssl_stream *) stream;
+	int ret;
+
+	if (st->connected && (ret = ssl_teardown(st->ssl)) < 0)
+		return -1;
+
+	st->connected = false;
+
+	return git_stream_close(st->io);
+}
+
+void openssl_free(git_stream *stream)
+{
+	openssl_stream *st = (openssl_stream *) stream;
+
+	SSL_free(st->ssl);
+	git__free(st->host);
+	git__free(st->cert_info.data);
+	git_stream_free(st->io);
+	git__free(st);
+}
+
+int git_openssl_stream_new(git_stream **out, const char *host, const char *port)
+{
+	int error;
+	openssl_stream *st;
+
+	st = git__calloc(1, sizeof(openssl_stream));
+	GITERR_CHECK_ALLOC(st);
+
+	st->io = NULL;
+#ifdef GIT_CURL
+	error = git_curl_stream_new(&st->io, host, port);
+#else
+	error = git_socket_stream_new(&st->io, host, port);
+#endif
+
+	if (error < 0)
+		goto out_err;
+
+	st->ssl = SSL_new(git__ssl_ctx);
+	if (st->ssl == NULL) {
+		giterr_set(GITERR_SSL, "failed to create ssl object");
+		error = -1;
+		goto out_err;
+	}
+
+	st->host = git__strdup(host);
+	GITERR_CHECK_ALLOC(st->host);
+
+	st->parent.version = GIT_STREAM_VERSION;
+	st->parent.encrypted = 1;
+	st->parent.proxy_support = git_stream_supports_proxy(st->io);
+	st->parent.connect = openssl_connect;
+	st->parent.certificate = openssl_certificate;
+	st->parent.set_proxy = openssl_set_proxy;
+	st->parent.read = openssl_read;
+	st->parent.write = openssl_write;
+	st->parent.close = openssl_close;
+	st->parent.free = openssl_free;
+
+	*out = (git_stream *) st;
+	return 0;
+
+out_err:
+	git_stream_free(st->io);
+	git__free(st);
+
+	return error;
+}
+
+int git_openssl__set_cert_location(const char *file, const char *path)
+{
+	if (SSL_CTX_load_verify_locations(git__ssl_ctx, file, path) == 0) {
+		char errmsg[256];
+
+		ERR_error_string_n(ERR_get_error(), errmsg, sizeof(errmsg));
+		giterr_set(GITERR_SSL, "OpenSSL error: failed to load certificates: %s",
+			errmsg);
+
+		return -1;
+	}
+	return 0;
+}
+
+#else
+
+#include "stream.h"
+#include "git2/sys/openssl.h"
+
+int git_openssl_stream_global_init(void)
+{
+	return 0;
+}
+
+int git_openssl_set_locking(void)
+{
+	giterr_set(GITERR_SSL, "libgit2 was not built with OpenSSL support");
+	return -1;
+}
+
+int git_openssl_stream_new(git_stream **out, const char *host, const char *port)
+{
+	GIT_UNUSED(out);
+	GIT_UNUSED(host);
+	GIT_UNUSED(port);
+
+	giterr_set(GITERR_SSL, "openssl is not supported in this version");
+	return -1;
+}
+
+int git_openssl__set_cert_location(const char *file, const char *path)
+{
+	GIT_UNUSED(file);
+	GIT_UNUSED(path);
+
+	giterr_set(GITERR_SSL, "openssl is not supported in this version");
+	return -1;
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/streams/openssl.h

diff --git a/vendor/libgit2-sys/libgit2/src/streams/openssl.h b/vendor/libgit2-sys/libgit2/src/streams/openssl.h
new file mode 100644
index 0000000..496d7ef
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/streams/openssl.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_streams_openssl_h__
+#define INCLUDE_streams_openssl_h__
+
+#include "common.h"
+
+#include "git2/sys/stream.h"
+
+extern int git_openssl_stream_global_init(void);
+
+extern int git_openssl_stream_new(git_stream **out, const char *host, const char *port);
+
+extern int git_openssl__set_cert_location(const char *file, const char *path);
+
+#endif

vendor/libgit2-sys/libgit2/src/streams/socket.c

diff --git a/vendor/libgit2-sys/libgit2/src/streams/socket.c b/vendor/libgit2-sys/libgit2/src/streams/socket.c
new file mode 100644
index 0000000..0c6073b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/streams/socket.c
@@ -0,0 +1,210 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "streams/socket.h"
+
+#include "posix.h"
+#include "netops.h"
+#include "stream.h"
+
+#ifndef _WIN32
+#	include <sys/types.h>
+#	include <sys/socket.h>
+#	include <sys/select.h>
+#	include <sys/time.h>
+#	include <netdb.h>
+#	include <netinet/in.h>
+#       include <arpa/inet.h>
+#else
+#	include <winsock2.h>
+#	include <ws2tcpip.h>
+#	ifdef _MSC_VER
+#		pragma comment(lib, "ws2_32")
+#	endif
+#endif
+
+#ifdef GIT_WIN32
+static void net_set_error(const char *str)
+{
+	int error = WSAGetLastError();
+	char * win32_error = git_win32_get_error_message(error);
+
+	if (win32_error) {
+		giterr_set(GITERR_NET, "%s: %s", str, win32_error);
+		git__free(win32_error);
+	} else {
+		giterr_set(GITERR_NET, str);
+	}
+}
+#else
+static void net_set_error(const char *str)
+{
+	giterr_set(GITERR_NET, "%s: %s", str, strerror(errno));
+}
+#endif
+
+static int close_socket(GIT_SOCKET s)
+{
+	if (s == INVALID_SOCKET)
+		return 0;
+
+#ifdef GIT_WIN32
+	if (SOCKET_ERROR == closesocket(s))
+		return -1;
+
+	if (0 != WSACleanup()) {
+		giterr_set(GITERR_OS, "winsock cleanup failed");
+		return -1;
+	}
+
+	return 0;
+#else
+	return close(s);
+#endif
+
+}
+
+int socket_connect(git_stream *stream)
+{
+	struct addrinfo *info = NULL, *p;
+	struct addrinfo hints;
+	git_socket_stream *st = (git_socket_stream *) stream;
+	GIT_SOCKET s = INVALID_SOCKET;
+	int ret;
+
+#ifdef GIT_WIN32
+	/* on win32, the WSA context needs to be initialized
+	 * before any socket calls can be performed */
+	WSADATA wsd;
+
+	if (WSAStartup(MAKEWORD(2,2), &wsd) != 0) {
+		giterr_set(GITERR_OS, "winsock init failed");
+		return -1;
+	}
+
+	if (LOBYTE(wsd.wVersion) != 2 || HIBYTE(wsd.wVersion) != 2) {
+		WSACleanup();
+		giterr_set(GITERR_OS, "winsock init failed");
+		return -1;
+	}
+#endif
+
+	memset(&hints, 0x0, sizeof(struct addrinfo));
+	hints.ai_socktype = SOCK_STREAM;
+	hints.ai_family = AF_UNSPEC;
+
+	if ((ret = p_getaddrinfo(st->host, st->port, &hints, &info)) != 0) {
+		giterr_set(GITERR_NET,
+			   "failed to resolve address for %s: %s", st->host, p_gai_strerror(ret));
+		return -1;
+	}
+
+	for (p = info; p != NULL; p = p->ai_next) {
+		s = socket(p->ai_family, p->ai_socktype | SOCK_CLOEXEC, p->ai_protocol);
+
+		if (s == INVALID_SOCKET)
+			continue;
+
+		if (connect(s, p->ai_addr, (socklen_t)p->ai_addrlen) == 0)
+			break;
+
+		/* If we can't connect, try the next one */
+		close_socket(s);
+		s = INVALID_SOCKET;
+	}
+
+	/* Oops, we couldn't connect to any address */
+	if (s == INVALID_SOCKET && p == NULL) {
+		giterr_set(GITERR_OS, "failed to connect to %s", st->host);
+		p_freeaddrinfo(info);
+		return -1;
+	}
+
+	st->s = s;
+	p_freeaddrinfo(info);
+	return 0;
+}
+
+ssize_t socket_write(git_stream *stream, const char *data, size_t len, int flags)
+{
+	ssize_t ret;
+	size_t off = 0;
+	git_socket_stream *st = (git_socket_stream *) stream;
+
+	while (off < len) {
+		errno = 0;
+		ret = p_send(st->s, data + off, len - off, flags);
+		if (ret < 0) {
+			net_set_error("Error sending data");
+			return -1;
+		}
+
+		off += ret;
+	}
+
+	return off;
+}
+
+ssize_t socket_read(git_stream *stream, void *data, size_t len)
+{
+	ssize_t ret;
+	git_socket_stream *st = (git_socket_stream *) stream;
+
+	if ((ret = p_recv(st->s, data, len, 0)) < 0)
+		net_set_error("Error receiving socket data");
+
+	return ret;
+}
+
+int socket_close(git_stream *stream)
+{
+	git_socket_stream *st = (git_socket_stream *) stream;
+	int error;
+
+	error = close_socket(st->s);
+	st->s = INVALID_SOCKET;
+
+	return error;
+}
+
+void socket_free(git_stream *stream)
+{
+	git_socket_stream *st = (git_socket_stream *) stream;
+
+	git__free(st->host);
+	git__free(st->port);
+	git__free(st);
+}
+
+int git_socket_stream_new(git_stream **out, const char *host, const char *port)
+{
+	git_socket_stream *st;
+
+	assert(out && host);
+
+	st = git__calloc(1, sizeof(git_socket_stream));
+	GITERR_CHECK_ALLOC(st);
+
+	st->host = git__strdup(host);
+	GITERR_CHECK_ALLOC(st->host);
+
+	if (port) {
+		st->port = git__strdup(port);
+		GITERR_CHECK_ALLOC(st->port);
+	}
+
+	st->parent.version = GIT_STREAM_VERSION;
+	st->parent.connect = socket_connect;
+	st->parent.write = socket_write;
+	st->parent.read = socket_read;
+	st->parent.close = socket_close;
+	st->parent.free = socket_free;
+	st->s = INVALID_SOCKET;
+
+	*out = (git_stream *) st;
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/streams/socket.h

diff --git a/vendor/libgit2-sys/libgit2/src/streams/socket.h b/vendor/libgit2-sys/libgit2/src/streams/socket.h
new file mode 100644
index 0000000..3235f31
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/streams/socket.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_streams_socket_h__
+#define INCLUDE_streams_socket_h__
+
+#include "common.h"
+
+#include "netops.h"
+
+typedef struct {
+	git_stream parent;
+	char *host;
+	char *port;
+	GIT_SOCKET s;
+} git_socket_stream;
+
+extern int git_socket_stream_new(git_stream **out, const char *host, const char *port);
+
+#endif

vendor/libgit2-sys/libgit2/src/streams/stransport.c

diff --git a/vendor/libgit2-sys/libgit2/src/streams/stransport.c b/vendor/libgit2-sys/libgit2/src/streams/stransport.c
new file mode 100644
index 0000000..cca17bb
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/streams/stransport.c
@@ -0,0 +1,298 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "streams/stransport.h"
+
+#ifdef GIT_SECURE_TRANSPORT
+
+#include <CoreFoundation/CoreFoundation.h>
+#include <Security/SecureTransport.h>
+#include <Security/SecCertificate.h>
+
+#include "git2/transport.h"
+
+#include "streams/socket.h"
+#include "streams/curl.h"
+
+static int stransport_error(OSStatus ret)
+{
+	CFStringRef message;
+
+	if (ret == noErr || ret == errSSLClosedGraceful) {
+		giterr_clear();
+		return 0;
+	}
+
+#if !TARGET_OS_IPHONE
+	message = SecCopyErrorMessageString(ret, NULL);
+	GITERR_CHECK_ALLOC(message);
+
+	giterr_set(GITERR_NET, "SecureTransport error: %s", CFStringGetCStringPtr(message, kCFStringEncodingUTF8));
+	CFRelease(message);
+#else
+    giterr_set(GITERR_NET, "SecureTransport error: OSStatus %d", (unsigned int)ret);
+    GIT_UNUSED(message);
+#endif
+
+	return -1;
+}
+
+typedef struct {
+	git_stream parent;
+	git_stream *io;
+	SSLContextRef ctx;
+	CFDataRef der_data;
+	git_cert_x509 cert_info;
+} stransport_stream;
+
+static int stransport_connect(git_stream *stream)
+{
+	stransport_stream *st = (stransport_stream *) stream;
+	int error;
+	SecTrustRef trust = NULL;
+	SecTrustResultType sec_res;
+	OSStatus ret;
+
+	if ((error = git_stream_connect(st->io)) < 0)
+		return error;
+
+	ret = SSLHandshake(st->ctx);
+	if (ret != errSSLServerAuthCompleted) {
+		giterr_set(GITERR_SSL, "unexpected return value from ssl handshake %d", ret);
+		return -1;
+	}
+
+	if ((ret = SSLCopyPeerTrust(st->ctx, &trust)) != noErr)
+		goto on_error;
+
+	if (!trust)
+		return GIT_ECERTIFICATE;
+
+	if ((ret = SecTrustEvaluate(trust, &sec_res)) != noErr)
+		goto on_error;
+
+	CFRelease(trust);
+
+	if (sec_res == kSecTrustResultInvalid || sec_res == kSecTrustResultOtherError) {
+		giterr_set(GITERR_SSL, "internal security trust error");
+		return -1;
+	}
+
+	if (sec_res == kSecTrustResultDeny || sec_res == kSecTrustResultRecoverableTrustFailure ||
+	    sec_res == kSecTrustResultFatalTrustFailure) {
+		giterr_set(GITERR_SSL, "untrusted connection error");
+		return GIT_ECERTIFICATE;
+	}
+
+	return 0;
+
+on_error:
+	if (trust)
+		CFRelease(trust);
+
+	return stransport_error(ret);
+}
+
+static int stransport_certificate(git_cert **out, git_stream *stream)
+{
+	stransport_stream *st = (stransport_stream *) stream;
+	SecTrustRef trust = NULL;
+	SecCertificateRef sec_cert;
+	OSStatus ret;
+
+	if ((ret = SSLCopyPeerTrust(st->ctx, &trust)) != noErr)
+		return stransport_error(ret);
+
+	sec_cert = SecTrustGetCertificateAtIndex(trust, 0);
+	st->der_data = SecCertificateCopyData(sec_cert);
+	CFRelease(trust);
+
+	if (st->der_data == NULL) {
+		giterr_set(GITERR_SSL, "retrieved invalid certificate data");
+		return -1;
+	}
+
+	st->cert_info.parent.cert_type = GIT_CERT_X509;
+	st->cert_info.data = (void *) CFDataGetBytePtr(st->der_data);
+	st->cert_info.len = CFDataGetLength(st->der_data);
+
+	*out = (git_cert *)&st->cert_info;
+	return 0;
+}
+
+static int stransport_set_proxy(
+	git_stream *stream,
+	const git_proxy_options *proxy_opts)
+{
+	stransport_stream *st = (stransport_stream *) stream;
+
+	return git_stream_set_proxy(st->io, proxy_opts);
+}
+
+/*
+ * Contrary to typical network IO callbacks, Secure Transport write callback is
+ * expected to write *all* passed data, not just as much as it can, and any
+ * other case would be considered a failure.
+ *
+ * This behavior is actually not specified in the Apple documentation, but is
+ * required for things to work correctly (and incidentally, that's also how
+ * Apple implements it in its projects at opensource.apple.com).
+ *
+ * Libgit2 streams happen to already have this very behavior so this is just
+ * passthrough.
+ */
+static OSStatus write_cb(SSLConnectionRef conn, const void *data, size_t *len)
+{
+	git_stream *io = (git_stream *) conn;
+
+	if (git_stream_write(io, data, *len, 0) < 0) {
+		return -36; /* "ioErr" from MacErrors.h which is not available on iOS */
+	}
+
+	return noErr;
+}
+
+static ssize_t stransport_write(git_stream *stream, const char *data, size_t len, int flags)
+{
+	stransport_stream *st = (stransport_stream *) stream;
+	size_t data_len, processed;
+	OSStatus ret;
+
+	GIT_UNUSED(flags);
+
+	data_len = len;
+	if ((ret = SSLWrite(st->ctx, data, data_len, &processed)) != noErr)
+		return stransport_error(ret);
+
+	return processed;
+}
+
+/*
+ * Contrary to typical network IO callbacks, Secure Transport read callback is
+ * expected to read *exactly* the requested number of bytes, not just as much
+ * as it can, and any other case would be considered a failure.
+ *
+ * This behavior is actually not specified in the Apple documentation, but is
+ * required for things to work correctly (and incidentally, that's also how
+ * Apple implements it in its projects at opensource.apple.com).
+ */
+static OSStatus read_cb(SSLConnectionRef conn, void *data, size_t *len)
+{
+	git_stream *io = (git_stream *) conn;
+	OSStatus error = noErr;
+	size_t off = 0;
+	ssize_t ret;
+
+	do {
+		ret = git_stream_read(io, data + off, *len - off);
+		if (ret < 0) {
+			error = -36; /* "ioErr" from MacErrors.h which is not available on iOS */
+			break;
+		}
+		if (ret == 0) {
+			error = errSSLClosedGraceful;
+			break;
+		}
+
+		off += ret;
+	} while (off < *len);
+
+	*len = off;
+	return error;
+}
+
+static ssize_t stransport_read(git_stream *stream, void *data, size_t len)
+{
+	stransport_stream *st = (stransport_stream *) stream;
+	size_t processed;
+	OSStatus ret;
+
+	if ((ret = SSLRead(st->ctx, data, len, &processed)) != noErr)
+		return stransport_error(ret);
+
+	return processed;
+}
+
+static int stransport_close(git_stream *stream)
+{
+	stransport_stream *st = (stransport_stream *) stream;
+	OSStatus ret;
+
+	ret = SSLClose(st->ctx);
+	if (ret != noErr && ret != errSSLClosedGraceful)
+		return stransport_error(ret);
+
+	return git_stream_close(st->io);
+}
+
+static void stransport_free(git_stream *stream)
+{
+	stransport_stream *st = (stransport_stream *) stream;
+
+	git_stream_free(st->io);
+	CFRelease(st->ctx);
+	if (st->der_data)
+		CFRelease(st->der_data);
+	git__free(st);
+}
+
+int git_stransport_stream_new(git_stream **out, const char *host, const char *port)
+{
+	stransport_stream *st;
+	int error;
+	OSStatus ret;
+
+	assert(out && host);
+
+	st = git__calloc(1, sizeof(stransport_stream));
+	GITERR_CHECK_ALLOC(st);
+
+#ifdef GIT_CURL
+	error = git_curl_stream_new(&st->io, host, port);
+#else
+	error = git_socket_stream_new(&st->io, host, port);
+#endif
+
+	if (error < 0){
+		git__free(st);
+		return error;
+	}
+
+	st->ctx = SSLCreateContext(NULL, kSSLClientSide, kSSLStreamType);
+	if (!st->ctx) {
+		giterr_set(GITERR_NET, "failed to create SSL context");
+		git__free(st);
+		return -1;
+	}
+
+	if ((ret = SSLSetIOFuncs(st->ctx, read_cb, write_cb)) != noErr ||
+	    (ret = SSLSetConnection(st->ctx, st->io)) != noErr ||
+	    (ret = SSLSetSessionOption(st->ctx, kSSLSessionOptionBreakOnServerAuth, true)) != noErr ||
+	    (ret = SSLSetProtocolVersionMin(st->ctx, kTLSProtocol1)) != noErr ||
+	    (ret = SSLSetProtocolVersionMax(st->ctx, kTLSProtocol12)) != noErr ||
+	    (ret = SSLSetPeerDomainName(st->ctx, host, strlen(host))) != noErr) {
+		CFRelease(st->ctx);
+		git__free(st);
+		return stransport_error(ret);
+	}
+
+	st->parent.version = GIT_STREAM_VERSION;
+	st->parent.encrypted = 1;
+	st->parent.proxy_support = git_stream_supports_proxy(st->io);
+	st->parent.connect = stransport_connect;
+	st->parent.certificate = stransport_certificate;
+	st->parent.set_proxy = stransport_set_proxy;
+	st->parent.read = stransport_read;
+	st->parent.write = stransport_write;
+	st->parent.close = stransport_close;
+	st->parent.free = stransport_free;
+
+	*out = (git_stream *) st;
+	return 0;
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/streams/stransport.h

diff --git a/vendor/libgit2-sys/libgit2/src/streams/stransport.h b/vendor/libgit2-sys/libgit2/src/streams/stransport.h
new file mode 100644
index 0000000..4c02d07
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/streams/stransport.h
@@ -0,0 +1,16 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_streams_stransport_h__
+#define INCLUDE_streams_stransport_h__
+
+#include "common.h"
+
+#include "git2/sys/stream.h"
+
+extern int git_stransport_stream_new(git_stream **out, const char *host, const char *port);
+
+#endif

vendor/libgit2-sys/libgit2/src/streams/tls.c

diff --git a/vendor/libgit2-sys/libgit2/src/streams/tls.c b/vendor/libgit2-sys/libgit2/src/streams/tls.c
new file mode 100644
index 0000000..1bcb0d9
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/streams/tls.c
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "streams/tls.h"
+
+#include "git2/errors.h"
+
+#include "streams/mbedtls.h"
+#include "streams/openssl.h"
+#include "streams/stransport.h"
+
+static git_stream_cb tls_ctor;
+
+int git_stream_register_tls(git_stream_cb ctor)
+{
+	tls_ctor = ctor;
+
+	return 0;
+}
+
+int git_tls_stream_new(git_stream **out, const char *host, const char *port)
+{
+
+	if (tls_ctor)
+		return tls_ctor(out, host, port);
+
+#ifdef GIT_SECURE_TRANSPORT
+	return git_stransport_stream_new(out, host, port);
+#elif defined(GIT_OPENSSL)
+	return git_openssl_stream_new(out, host, port);
+#elif defined(GIT_MBEDTLS)
+	return git_mbedtls_stream_new(out, host, port);
+#else
+	GIT_UNUSED(out);
+	GIT_UNUSED(host);
+	GIT_UNUSED(port);
+
+	giterr_set(GITERR_SSL, "there is no TLS stream available");
+	return -1;
+#endif
+}

vendor/libgit2-sys/libgit2/src/streams/tls.h

diff --git a/vendor/libgit2-sys/libgit2/src/streams/tls.h b/vendor/libgit2-sys/libgit2/src/streams/tls.h
new file mode 100644
index 0000000..6d110e8
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/streams/tls.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_streams_tls_h__
+#define INCLUDE_streams_tls_h__
+
+#include "common.h"
+
+#include "git2/sys/stream.h"
+
+/**
+ * Create a TLS stream with the most appropriate backend available for
+ * the current platform.
+ *
+ * This allows us to ask for a SecureTransport or OpenSSL stream
+ * according to being on general Unix vs OS X.
+ */
+extern int git_tls_stream_new(git_stream **out, const char *host, const char *port);
+
+#endif

vendor/libgit2-sys/libgit2/src/strmap.c

diff --git a/vendor/libgit2-sys/libgit2/src/strmap.c b/vendor/libgit2-sys/libgit2/src/strmap.c
new file mode 100644
index 0000000..de6826d
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/strmap.c
@@ -0,0 +1,127 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "strmap.h"
+
+__KHASH_IMPL(str, static kh_inline, const char *, void *, 1, kh_str_hash_func, kh_str_hash_equal)
+
+int git_strmap_alloc(git_strmap **map)
+{
+	if ((*map = kh_init(str)) == NULL) {
+		giterr_set_oom();
+		return -1;
+	}
+
+	return 0;
+}
+
+void git_strmap_free(git_strmap *map)
+{
+	kh_destroy(str, map);
+}
+
+void git_strmap_clear(git_strmap *map)
+{
+	kh_clear(str, map);
+}
+
+size_t git_strmap_num_entries(git_strmap *map)
+{
+	return kh_size(map);
+}
+
+size_t git_strmap_lookup_index(git_strmap *map, const char *key)
+{
+	return kh_get(str, map, key);
+}
+
+int git_strmap_valid_index(git_strmap *map, size_t idx)
+{
+	return idx != kh_end(map);
+}
+
+int git_strmap_exists(git_strmap *map, const char *key)
+{
+	return kh_get(str, map, key) != kh_end(map);
+}
+
+int git_strmap_has_data(git_strmap *map, size_t idx)
+{
+	return kh_exist(map, idx);
+}
+
+const char *git_strmap_key(git_strmap *map, size_t idx)
+{
+	return kh_key(map, idx);
+}
+
+void git_strmap_set_key_at(git_strmap *map, size_t idx, char *key)
+{
+	kh_val(map, idx) = key;
+}
+
+void *git_strmap_value_at(git_strmap *map, size_t idx)
+{
+	return kh_val(map, idx);
+}
+
+void git_strmap_set_value_at(git_strmap *map, size_t idx, void *value)
+{
+	kh_val(map, idx) = value;
+}
+
+void git_strmap_delete_at(git_strmap *map, size_t idx)
+{
+	kh_del(str, map, idx);
+}
+
+int git_strmap_put(git_strmap *map, const char *key, int *err)
+{
+	return kh_put(str, map, key, err);
+}
+
+void git_strmap_insert(git_strmap *map, const char *key, void *value, int *rval)
+{
+	khiter_t idx = kh_put(str, map, key, rval);
+
+	if ((*rval) >= 0) {
+		if ((*rval) == 0)
+			kh_key(map, idx) = key;
+		kh_val(map, idx) = value;
+	}
+}
+
+void git_strmap_delete(git_strmap *map, const char *key)
+{
+	khiter_t idx = git_strmap_lookup_index(map, key);
+	if (git_strmap_valid_index(map, idx))
+		git_strmap_delete_at(map, idx);
+}
+
+int git_strmap_next(
+	void **data,
+	git_strmap_iter* iter,
+	git_strmap *map)
+{
+	if (!map)
+		return GIT_ERROR;
+
+	while (*iter != git_strmap_end(map)) {
+		if (!(git_strmap_has_data(map, *iter))) {
+			++(*iter);
+			continue;
+		}
+
+		*data = git_strmap_value_at(map, *iter);
+
+		++(*iter);
+
+		return GIT_OK;
+	}
+
+	return GIT_ITEROVER;
+}

vendor/libgit2-sys/libgit2/src/strmap.h

diff --git a/vendor/libgit2-sys/libgit2/src/strmap.h b/vendor/libgit2-sys/libgit2/src/strmap.h
new file mode 100644
index 0000000..802b924
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/strmap.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_strmap_h__
+#define INCLUDE_strmap_h__
+
+#include "common.h"
+
+#define kmalloc git__malloc
+#define kcalloc git__calloc
+#define krealloc git__realloc
+#define kreallocarray git__reallocarray
+#define kfree git__free
+#include "khash.h"
+
+__KHASH_TYPE(str, const char *, void *)
+typedef khash_t(str) git_strmap;
+typedef khiter_t git_strmap_iter;
+
+int git_strmap_alloc(git_strmap **map);
+void git_strmap_free(git_strmap *map);
+void git_strmap_clear(git_strmap *map);
+
+size_t git_strmap_num_entries(git_strmap *map);
+
+size_t git_strmap_lookup_index(git_strmap *map, const char *key);
+int git_strmap_valid_index(git_strmap *map, size_t idx);
+
+int git_strmap_exists(git_strmap *map, const char *key);
+int git_strmap_has_data(git_strmap *map, size_t idx);
+
+const char *git_strmap_key(git_strmap *map, size_t idx);
+void git_strmap_set_key_at(git_strmap *map, size_t idx, char *key);
+void *git_strmap_value_at(git_strmap *map, size_t idx);
+void git_strmap_set_value_at(git_strmap *map, size_t idx, void *value);
+void git_strmap_delete_at(git_strmap *map, size_t idx);
+
+int git_strmap_put(git_strmap *map, const char *key, int *err);
+void git_strmap_insert(git_strmap *map, const char *key, void *value, int *rval);
+void git_strmap_delete(git_strmap *map, const char *key);
+
+#define git_strmap_foreach		kh_foreach
+#define git_strmap_foreach_value	kh_foreach_value
+
+#define git_strmap_begin		kh_begin
+#define git_strmap_end		kh_end
+
+int git_strmap_next(
+	void **data,
+	git_strmap_iter* iter,
+	git_strmap *map);
+
+#endif

vendor/libgit2-sys/libgit2/src/strnlen.h

diff --git a/vendor/libgit2-sys/libgit2/src/strnlen.h b/vendor/libgit2-sys/libgit2/src/strnlen.h
new file mode 100644
index 0000000..eecfe3c
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/strnlen.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_strlen_h__
+#define INCLUDE_strlen_h__
+
+#if defined(__MINGW32__) || defined(__sun) || defined(__APPLE__) || defined(__MidnightBSD__) ||\
+	(defined(_MSC_VER) && _MSC_VER < 1500)
+#   define NO_STRNLEN
+#endif
+
+#ifdef NO_STRNLEN
+GIT_INLINE(size_t) p_strnlen(const char *s, size_t maxlen) {
+	const char *end = memchr(s, 0, maxlen);
+	return end ? (size_t)(end - s) : maxlen;
+}
+#else
+#   define p_strnlen strnlen
+#endif
+
+#endif

vendor/libgit2-sys/libgit2/src/submodule.c

diff --git a/vendor/libgit2-sys/libgit2/src/submodule.c b/vendor/libgit2-sys/libgit2/src/submodule.c
new file mode 100644
index 0000000..b927b17
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/submodule.c
@@ -0,0 +1,2283 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "submodule.h"
+
+#include "git2/config.h"
+#include "git2/sys/config.h"
+#include "git2/types.h"
+#include "git2/index.h"
+#include "buffer.h"
+#include "buf_text.h"
+#include "vector.h"
+#include "posix.h"
+#include "config_file.h"
+#include "config.h"
+#include "repository.h"
+#include "tree.h"
+#include "iterator.h"
+#include "path.h"
+#include "index.h"
+#include "worktree.h"
+
+#define GIT_MODULES_FILE ".gitmodules"
+
+static git_cvar_map _sm_update_map[] = {
+	{GIT_CVAR_STRING, "checkout", GIT_SUBMODULE_UPDATE_CHECKOUT},
+	{GIT_CVAR_STRING, "rebase", GIT_SUBMODULE_UPDATE_REBASE},
+	{GIT_CVAR_STRING, "merge", GIT_SUBMODULE_UPDATE_MERGE},
+	{GIT_CVAR_STRING, "none", GIT_SUBMODULE_UPDATE_NONE},
+	{GIT_CVAR_FALSE, NULL, GIT_SUBMODULE_UPDATE_NONE},
+	{GIT_CVAR_TRUE, NULL, GIT_SUBMODULE_UPDATE_CHECKOUT},
+};
+
+static git_cvar_map _sm_ignore_map[] = {
+	{GIT_CVAR_STRING, "none", GIT_SUBMODULE_IGNORE_NONE},
+	{GIT_CVAR_STRING, "untracked", GIT_SUBMODULE_IGNORE_UNTRACKED},
+	{GIT_CVAR_STRING, "dirty", GIT_SUBMODULE_IGNORE_DIRTY},
+	{GIT_CVAR_STRING, "all", GIT_SUBMODULE_IGNORE_ALL},
+	{GIT_CVAR_FALSE, NULL, GIT_SUBMODULE_IGNORE_NONE},
+	{GIT_CVAR_TRUE, NULL, GIT_SUBMODULE_IGNORE_ALL},
+};
+
+static git_cvar_map _sm_recurse_map[] = {
+	{GIT_CVAR_STRING, "on-demand", GIT_SUBMODULE_RECURSE_ONDEMAND},
+	{GIT_CVAR_FALSE, NULL, GIT_SUBMODULE_RECURSE_NO},
+	{GIT_CVAR_TRUE, NULL, GIT_SUBMODULE_RECURSE_YES},
+};
+
+enum {
+	CACHE_OK = 0,
+	CACHE_REFRESH = 1,
+	CACHE_FLUSH = 2
+};
+enum {
+	GITMODULES_EXISTING = 0,
+	GITMODULES_CREATE = 1,
+};
+
+static kh_inline khint_t str_hash_no_trailing_slash(const char *s)
+{
+	khint_t h;
+
+	for (h = 0; *s; ++s)
+		if (s[1] != '\0' || *s != '/')
+			h = (h << 5) - h + *s;
+
+	return h;
+}
+
+static kh_inline int str_equal_no_trailing_slash(const char *a, const char *b)
+{
+	size_t alen = a ? strlen(a) : 0;
+	size_t blen = b ? strlen(b) : 0;
+
+	if (alen > 0 && a[alen - 1] == '/')
+		alen--;
+	if (blen > 0 && b[blen - 1] == '/')
+		blen--;
+
+	return (alen == 0 && blen == 0) ||
+		(alen == blen && strncmp(a, b, alen) == 0);
+}
+
+__KHASH_IMPL(
+	str, static kh_inline, const char *, void *, 1,
+	str_hash_no_trailing_slash, str_equal_no_trailing_slash)
+
+static int submodule_alloc(git_submodule **out, git_repository *repo, const char *name);
+static git_config_backend *open_gitmodules(git_repository *repo, int gitmod);
+static int gitmodules_snapshot(git_config **snap, git_repository *repo);
+static int get_url_base(git_buf *url, git_repository *repo);
+static int lookup_head_remote_key(git_buf *remote_key, git_repository *repo);
+static int lookup_default_remote(git_remote **remote, git_repository *repo);
+static int submodule_load_each(const git_config_entry *entry, void *payload);
+static int submodule_read_config(git_submodule *sm, git_config *cfg);
+static int submodule_load_from_wd_lite(git_submodule *);
+static void submodule_get_index_status(unsigned int *, git_submodule *);
+static void submodule_get_wd_status(unsigned int *, git_submodule *, git_repository *, git_submodule_ignore_t);
+static void submodule_update_from_index_entry(git_submodule *sm, const git_index_entry *ie);
+static void submodule_update_from_head_data(git_submodule *sm, mode_t mode, const git_oid *id);
+
+static int submodule_cmp(const void *a, const void *b)
+{
+	return strcmp(((git_submodule *)a)->name, ((git_submodule *)b)->name);
+}
+
+static int submodule_config_key_trunc_puts(git_buf *key, const char *suffix)
+{
+	ssize_t idx = git_buf_rfind(key, '.');
+	git_buf_truncate(key, (size_t)(idx + 1));
+	return git_buf_puts(key, suffix);
+}
+
+/*
+ * PUBLIC APIS
+ */
+
+static void submodule_set_lookup_error(int error, const char *name)
+{
+	if (!error)
+		return;
+
+	giterr_set(GITERR_SUBMODULE, (error == GIT_ENOTFOUND) ?
+		"no submodule named '%s'" :
+		"submodule '%s' has not been added yet", name);
+}
+
+typedef struct {
+	const char *path;
+	char *name;
+} fbp_data;
+
+static int find_by_path(const git_config_entry *entry, void *payload)
+{
+	fbp_data *data = payload;
+
+	if (!strcmp(entry->value, data->path)) {
+		const char *fdot, *ldot;
+		fdot = strchr(entry->name, '.');
+		ldot = strrchr(entry->name, '.');
+		data->name = git__strndup(fdot + 1, ldot - fdot - 1);
+		GITERR_CHECK_ALLOC(data->name);
+	}
+
+	return 0;
+}
+
+/*
+ * Checks to see if the submodule shares its name with a file or directory that
+ * already exists on the index. If so, the submodule cannot be added.
+ */
+static int is_path_occupied(bool *occupied, git_repository *repo, const char *path)
+{
+	int error = 0;
+	git_index *index;
+	git_buf dir = GIT_BUF_INIT;
+	*occupied = false;
+
+	if ((error = git_repository_index__weakptr(&index, repo)) < 0)
+		goto out;
+
+	if ((error = git_index_find(NULL, index, path)) != GIT_ENOTFOUND) {
+		if (!error) {
+			giterr_set(GITERR_SUBMODULE,
+				"File '%s' already exists in the index", path);
+			*occupied = true;
+		}
+		goto out;
+	}
+
+	if ((error = git_buf_sets(&dir, path)) < 0)
+		goto out;
+
+	if ((error = git_path_to_dir(&dir)) < 0)
+		goto out;
+
+	if ((error = git_index_find_prefix(NULL, index, dir.ptr)) != GIT_ENOTFOUND) {
+		if (!error) {
+			giterr_set(GITERR_SUBMODULE,
+				"Directory '%s' already exists in the index", path);
+			*occupied = true;
+		}
+		goto out;
+	}
+
+	error = 0;
+
+out:
+	git_buf_free(&dir);
+	return error;
+}
+
+/**
+ * Release the name map returned by 'load_submodule_names'.
+ */
+static void free_submodule_names(git_strmap *names)
+{
+	git_buf *name = 0;
+	if (names == NULL)
+		return;
+	git_strmap_foreach_value(names, name, {
+		git__free(name);
+	});
+	git_strmap_free(names);
+	return;
+}
+
+/**
+ * Map submodule paths to names.
+ * TODO: for some use-cases, this might need case-folding on a
+ * case-insensitive filesystem
+ */
+static int load_submodule_names(git_strmap *out, git_repository *repo, git_config *cfg)
+{
+	const char *key = "submodule\\..*\\.path";
+	git_config_iterator *iter;
+	git_config_entry *entry;
+	git_buf buf = GIT_BUF_INIT;
+	int rval, isvalid;
+	int error = 0;
+
+	if ((error = git_config_iterator_glob_new(&iter, cfg, key)) < 0)
+		return error;
+
+	while (git_config_next(&entry, iter) == 0) {
+		const char *fdot, *ldot;
+		fdot = strchr(entry->name, '.');
+		ldot = strrchr(entry->name, '.');
+
+		git_buf_clear(&buf);
+		git_buf_put(&buf, fdot + 1, ldot - fdot - 1);
+		isvalid = git_submodule_name_is_valid(repo, buf.ptr, 0);
+		if (isvalid < 0) {
+			error = isvalid;
+			goto out;
+		}
+		if (!isvalid)
+			continue;
+
+		git_strmap_insert(out, entry->value, git_buf_detach(&buf), &rval);
+		if (rval < 0) {
+			giterr_set(GITERR_NOMEMORY, "error inserting submodule into hash table");
+			return -1;
+		}
+	}
+	if (error == GIT_ITEROVER)
+		error = 0;
+
+out:
+	git_buf_free(&buf);
+	git_config_iterator_free(iter);
+	return error;
+}
+
+int git_submodule_lookup(
+	git_submodule **out, /* NULL if user only wants to test existence */
+	git_repository *repo,
+	const char *name)    /* trailing slash is allowed */
+{
+	int error;
+	unsigned int location;
+	git_submodule *sm;
+
+	assert(repo && name);
+
+	if (repo->is_bare) {
+		giterr_set(GITERR_SUBMODULE, "cannot get submodules without a working tree");
+		return -1;
+	}
+
+	if (repo->submodule_cache != NULL) {
+		khiter_t pos = git_strmap_lookup_index(repo->submodule_cache, name);
+		if (git_strmap_valid_index(repo->submodule_cache, pos)) {
+			if (out) {
+				*out = git_strmap_value_at(repo->submodule_cache, pos);
+				GIT_REFCOUNT_INC(*out);
+			}
+			return 0;
+		}
+	}
+
+	if ((error = submodule_alloc(&sm, repo, name)) < 0)
+		return error;
+
+	if ((error = git_submodule_reload(sm, false)) < 0) {
+		git_submodule_free(sm);
+		return error;
+	}
+
+	if ((error = git_submodule_location(&location, sm)) < 0) {
+		git_submodule_free(sm);
+		return error;
+	}
+
+	/* If it's not configured or we're looking by path  */
+	if (location == 0 || location == GIT_SUBMODULE_STATUS_IN_WD) {
+		git_config_backend *mods;
+		const char *pattern = "submodule\\..*\\.path";
+		git_buf path = GIT_BUF_INIT;
+		fbp_data data = { NULL, NULL };
+
+		git_buf_puts(&path, name);
+		while (path.ptr[path.size-1] == '/') {
+			path.ptr[--path.size] = '\0';
+		}
+		data.path = path.ptr;
+
+		mods = open_gitmodules(repo, GITMODULES_EXISTING);
+
+		if (mods)
+			error = git_config_file_foreach_match(mods, pattern, find_by_path, &data);
+
+		git_config_file_free(mods);
+
+		if (error < 0) {
+			git_submodule_free(sm);
+			git_buf_free(&path);
+			return error;
+		}
+
+		if (data.name) {
+			git__free(sm->name);
+			sm->name = data.name;
+			sm->path = git_buf_detach(&path);
+
+			/* Try to load again with the right name */
+			if ((error = git_submodule_reload(sm, false)) < 0) {
+				git_submodule_free(sm);
+				return error;
+			}
+		}
+
+		git_buf_free(&path);
+	}
+
+	if ((error = git_submodule_location(&location, sm)) < 0) {
+		git_submodule_free(sm);
+		return error;
+	}
+
+	/* If we still haven't found it, do the WD check */
+	if (location == 0 || location == GIT_SUBMODULE_STATUS_IN_WD) {
+		git_submodule_free(sm);
+		error = GIT_ENOTFOUND;
+
+		/* If it's not configured, we still check if there's a repo at the path */
+		if (git_repository_workdir(repo)) {
+			git_buf path = GIT_BUF_INIT;
+			if (git_buf_join3(&path,
+					  '/', git_repository_workdir(repo), name, DOT_GIT) < 0)
+				return -1;
+
+			if (git_path_exists(path.ptr))
+				error = GIT_EEXISTS;
+
+			git_buf_free(&path);
+		}
+
+		submodule_set_lookup_error(error, name);
+		return error;
+	}
+
+	if (out)
+		*out = sm;
+	else
+		git_submodule_free(sm);
+
+	return 0;
+}
+
+int git_submodule_name_is_valid(git_repository *repo, const char *name, int flags)
+{
+	git_buf buf = GIT_BUF_INIT;
+	int error, isvalid;
+
+	if (flags == 0)
+		flags = GIT_PATH_REJECT_FILESYSTEM_DEFAULTS;
+
+	/* Avoid allocating a new string if we can avoid it */
+	if (strchr(name, '\\') != NULL) {
+		if ((error = git_path_normalize_slashes(&buf, name)) < 0)
+			return error;
+	} else {
+		git_buf_attach_notowned(&buf, name, strlen(name));
+	}
+
+	isvalid =  git_path_isvalid(repo, buf.ptr, 0, flags);
+	git_buf_free(&buf);
+
+	return isvalid;
+}
+
+static void submodule_free_dup(void *sm)
+{
+	git_submodule_free(sm);
+}
+
+static int submodule_get_or_create(git_submodule **out, git_repository *repo, git_strmap *map, const char *name)
+{
+	int error = 0;
+	khiter_t pos;
+	git_submodule *sm = NULL;
+
+	pos = git_strmap_lookup_index(map, name);
+	if (git_strmap_valid_index(map, pos)) {
+		sm = git_strmap_value_at(map, pos);
+		goto done;
+	}
+
+	/* if the submodule doesn't exist yet in the map, create it */
+	if ((error = submodule_alloc(&sm, repo, name)) < 0)
+		return error;
+
+	pos = git_strmap_put(map, sm->name, &error);
+	/* nobody can beat us to adding it */
+	assert(error != 0);
+	if (error < 0) {
+		git_submodule_free(sm);
+		return error;
+	}
+
+	git_strmap_set_value_at(map, pos, sm);
+
+done:
+	GIT_REFCOUNT_INC(sm);
+	*out = sm;
+	return 0;
+}
+
+static int submodules_from_index(git_strmap *map, git_index *idx, git_config *cfg)
+{
+	int error;
+	git_iterator *i = NULL;
+	const git_index_entry *entry;
+	git_strmap *names = 0;
+
+	git_strmap_alloc(&names);
+	if ((error = load_submodule_names(names, git_index_owner(idx), cfg)))
+		goto done;
+
+	if ((error = git_iterator_for_index(&i, git_index_owner(idx), idx, NULL)) < 0)
+		goto done;
+
+	while (!(error = git_iterator_advance(&entry, i))) {
+		khiter_t pos = git_strmap_lookup_index(map, entry->path);
+		git_submodule *sm;
+
+		if (git_strmap_valid_index(map, pos)) {
+			sm = git_strmap_value_at(map, pos);
+
+			if (S_ISGITLINK(entry->mode))
+				submodule_update_from_index_entry(sm, entry);
+			else
+				sm->flags |= GIT_SUBMODULE_STATUS__INDEX_NOT_SUBMODULE;
+		} else if (S_ISGITLINK(entry->mode)) {
+			khiter_t name_pos;
+			const char *name;
+
+			name_pos = git_strmap_lookup_index(names, entry->path);
+			if (git_strmap_valid_index(names, name_pos)) {
+				name = git_strmap_value_at(names, name_pos);
+			} else {
+				name = entry->path;
+			}
+
+			if (!submodule_get_or_create(&sm, git_index_owner(idx), map, name)) {
+				submodule_update_from_index_entry(sm, entry);
+				git_submodule_free(sm);
+			}
+		}
+	}
+
+	if (error == GIT_ITEROVER)
+		error = 0;
+
+done:
+	git_iterator_free(i);
+	free_submodule_names(names);
+
+	return error;
+}
+
+static int submodules_from_head(git_strmap *map, git_tree *head, git_config *cfg)
+{
+	int error;
+	git_iterator *i = NULL;
+	const git_index_entry *entry;
+	git_strmap *names = 0;
+	git_strmap_alloc(&names);
+	if ((error = load_submodule_names(names, git_tree_owner(head), cfg)))
+		goto done;
+
+	if ((error = git_iterator_for_tree(&i, head, NULL)) < 0)
+		goto done;
+
+	while (!(error = git_iterator_advance(&entry, i))) {
+		khiter_t pos = git_strmap_lookup_index(map, entry->path);
+		git_submodule *sm;
+
+		if (git_strmap_valid_index(map, pos)) {
+			sm = git_strmap_value_at(map, pos);
+
+			if (S_ISGITLINK(entry->mode))
+				submodule_update_from_head_data(sm, entry->mode, &entry->id);
+			else
+				sm->flags |= GIT_SUBMODULE_STATUS__HEAD_NOT_SUBMODULE;
+		} else if (S_ISGITLINK(entry->mode)) {
+			khiter_t name_pos;
+			const char *name;
+
+			name_pos = git_strmap_lookup_index(names, entry->path);
+			if (git_strmap_valid_index(names, name_pos)) {
+				name = git_strmap_value_at(names, name_pos);
+			} else {
+				name = entry->path;
+			}
+
+			if (!submodule_get_or_create(&sm, git_tree_owner(head), map, name)) {
+				submodule_update_from_head_data(
+					sm, entry->mode, &entry->id);
+				git_submodule_free(sm);
+			}
+		}
+	}
+
+	if (error == GIT_ITEROVER)
+		error = 0;
+
+done:
+	git_iterator_free(i);
+	free_submodule_names(names);
+
+	return error;
+}
+
+/* If have_sm is true, sm is populated, otherwise map an repo are. */
+typedef struct {
+	git_config *mods;
+	git_strmap *map;
+	git_repository *repo;
+} lfc_data;
+
+int git_submodule__map(git_repository *repo, git_strmap *map)
+{
+	int error = 0;
+	git_index *idx = NULL;
+	git_tree *head = NULL;
+	const char *wd = NULL;
+	git_buf path = GIT_BUF_INIT;
+	git_submodule *sm;
+	git_config *mods = NULL;
+	uint32_t mask;
+
+	assert(repo && map);
+
+	/* get sources that we will need to check */
+	if (git_repository_index(&idx, repo) < 0)
+		giterr_clear();
+	if (git_repository_head_tree(&head, repo) < 0)
+		giterr_clear();
+
+	wd = git_repository_workdir(repo);
+	if (wd && (error = git_buf_joinpath(&path, wd, GIT_MODULES_FILE)) < 0)
+		goto cleanup;
+
+	/* clear submodule flags that are to be refreshed */
+	mask = 0;
+	mask |= GIT_SUBMODULE_STATUS_IN_INDEX |
+		GIT_SUBMODULE_STATUS__INDEX_FLAGS |
+		GIT_SUBMODULE_STATUS__INDEX_OID_VALID |
+		GIT_SUBMODULE_STATUS__INDEX_MULTIPLE_ENTRIES;
+
+	mask |= GIT_SUBMODULE_STATUS_IN_HEAD |
+		GIT_SUBMODULE_STATUS__HEAD_OID_VALID;
+	mask |= GIT_SUBMODULE_STATUS_IN_CONFIG;
+	if (mask != 0)
+		mask |= GIT_SUBMODULE_STATUS_IN_WD |
+			GIT_SUBMODULE_STATUS__WD_SCANNED |
+			GIT_SUBMODULE_STATUS__WD_FLAGS |
+			GIT_SUBMODULE_STATUS__WD_OID_VALID;
+
+	/* add submodule information from .gitmodules */
+	if (wd) {
+		lfc_data data = { 0 };
+		data.map = map;
+		data.repo = repo;
+
+		if ((error = gitmodules_snapshot(&mods, repo)) < 0) {
+			if (error == GIT_ENOTFOUND)
+				error = 0;
+			goto cleanup;
+		}
+
+		data.mods = mods;
+		if ((error = git_config_foreach(
+			    mods, submodule_load_each, &data)) < 0)
+			goto cleanup;
+	}
+	/* add back submodule information from index */
+	if (mods && idx) {
+		if ((error = submodules_from_index(map, idx, mods)) < 0)
+			goto cleanup;
+	}
+	/* add submodule information from HEAD */
+	if (mods && head) {
+		if ((error = submodules_from_head(map, head, mods)) < 0)
+			goto cleanup;
+	}
+	/* shallow scan submodules in work tree as needed */
+	if (wd && mask != 0) {
+		git_strmap_foreach_value(map, sm, {
+				submodule_load_from_wd_lite(sm);
+			});
+	}
+
+cleanup:
+	git_config_free(mods);
+	/* TODO: if we got an error, mark submodule config as invalid? */
+	git_index_free(idx);
+	git_tree_free(head);
+	git_buf_free(&path);
+	return error;
+}
+
+int git_submodule_foreach(
+	git_repository *repo,
+	git_submodule_cb callback,
+	void *payload)
+{
+	git_vector snapshot = GIT_VECTOR_INIT;
+	git_strmap *submodules;
+	git_submodule *sm;
+	int error;
+	size_t i;
+
+	if (repo->is_bare) {
+		giterr_set(GITERR_SUBMODULE, "cannot get submodules without a working tree");
+		return -1;
+	}
+
+	if ((error = git_strmap_alloc(&submodules)) < 0)
+		return error;
+
+	if ((error = git_submodule__map(repo, submodules)) < 0)
+		goto done;
+
+	if (!(error = git_vector_init(
+			&snapshot, git_strmap_num_entries(submodules), submodule_cmp))) {
+
+		git_strmap_foreach_value(submodules, sm, {
+			if ((error = git_vector_insert(&snapshot, sm)) < 0)
+				break;
+			GIT_REFCOUNT_INC(sm);
+		});
+	}
+
+	if (error < 0)
+		goto done;
+
+	git_vector_uniq(&snapshot, submodule_free_dup);
+
+	git_vector_foreach(&snapshot, i, sm) {
+		if ((error = callback(sm, sm->name, payload)) != 0) {
+			giterr_set_after_callback(error);
+			break;
+		}
+	}
+
+done:
+	git_vector_foreach(&snapshot, i, sm)
+		git_submodule_free(sm);
+	git_vector_free(&snapshot);
+
+	git_strmap_foreach_value(submodules, sm, {
+		git_submodule_free(sm);
+	});
+	git_strmap_free(submodules);
+
+	return error;
+}
+
+static int submodule_repo_init(
+	git_repository **out,
+	git_repository *parent_repo,
+	const char *path,
+	const char *url,
+	bool use_gitlink)
+{
+	int error = 0;
+	git_buf workdir = GIT_BUF_INIT, repodir = GIT_BUF_INIT;
+	git_repository_init_options initopt = GIT_REPOSITORY_INIT_OPTIONS_INIT;
+	git_repository *subrepo = NULL;
+
+	error = git_buf_joinpath(&workdir, git_repository_workdir(parent_repo), path);
+	if (error < 0)
+		goto cleanup;
+
+	initopt.flags = GIT_REPOSITORY_INIT_MKPATH | GIT_REPOSITORY_INIT_NO_REINIT;
+	initopt.origin_url = url;
+
+	/* init submodule repository and add origin remote as needed */
+
+	/* New style: sub-repo goes in <repo-dir>/modules/<name>/ with a
+	 * gitlink in the sub-repo workdir directory to that repository
+	 *
+	 * Old style: sub-repo goes directly into repo/<name>/.git/
+	 */
+	 if (use_gitlink) {
+		error = git_repository_item_path(&repodir, parent_repo, GIT_REPOSITORY_ITEM_MODULES);
+		if (error < 0)
+			goto cleanup;
+		error = git_buf_joinpath(&repodir, repodir.ptr, path);
+		if (error < 0)
+			goto cleanup;
+
+		initopt.workdir_path = workdir.ptr;
+		initopt.flags |=
+			GIT_REPOSITORY_INIT_NO_DOTGIT_DIR |
+			GIT_REPOSITORY_INIT_RELATIVE_GITLINK;
+
+		error = git_repository_init_ext(&subrepo, repodir.ptr, &initopt);
+	} else
+		error = git_repository_init_ext(&subrepo, workdir.ptr, &initopt);
+
+cleanup:
+	git_buf_free(&workdir);
+	git_buf_free(&repodir);
+
+	*out = subrepo;
+
+	return error;
+}
+
+int git_submodule_add_setup(
+	git_submodule **out,
+	git_repository *repo,
+	const char *url,
+	const char *path,
+	int use_gitlink)
+{
+	int error = 0;
+	git_config_backend *mods = NULL;
+	git_submodule *sm = NULL;
+	git_buf name = GIT_BUF_INIT, real_url = GIT_BUF_INIT;
+	git_repository *subrepo = NULL;
+	bool path_occupied;
+
+	assert(repo && url && path);
+
+	/* see if there is already an entry for this submodule */
+
+	if (git_submodule_lookup(NULL, repo, path) < 0)
+		giterr_clear();
+	else {
+		giterr_set(GITERR_SUBMODULE,
+			"attempt to add submodule '%s' that already exists", path);
+		return GIT_EEXISTS;
+	}
+
+	/* validate and normalize path */
+
+	if (git__prefixcmp(path, git_repository_workdir(repo)) == 0)
+		path += strlen(git_repository_workdir(repo));
+
+	if (git_path_root(path) >= 0) {
+		giterr_set(GITERR_SUBMODULE, "submodule path must be a relative path");
+		error = -1;
+		goto cleanup;
+	}
+
+	if ((error = is_path_occupied(&path_occupied, repo, path)) < 0)
+		goto cleanup;
+
+	if (path_occupied) {
+		error = GIT_EEXISTS;
+		goto cleanup;
+	}
+
+	/* update .gitmodules */
+
+	if (!(mods = open_gitmodules(repo, GITMODULES_CREATE))) {
+		giterr_set(GITERR_SUBMODULE,
+			"adding submodules to a bare repository is not supported");
+		return -1;
+	}
+
+	if ((error = git_buf_printf(&name, "submodule.%s.path", path)) < 0 ||
+		(error = git_config_file_set_string(mods, name.ptr, path)) < 0)
+		goto cleanup;
+
+	if ((error = submodule_config_key_trunc_puts(&name, "url")) < 0 ||
+		(error = git_config_file_set_string(mods, name.ptr, url)) < 0)
+		goto cleanup;
+
+	git_buf_clear(&name);
+
+	/* init submodule repository and add origin remote as needed */
+
+	error = git_buf_joinpath(&name, git_repository_workdir(repo), path);
+	if (error < 0)
+		goto cleanup;
+
+	/* if the repo does not already exist, then init a new repo and add it.
+	 * Otherwise, just add the existing repo.
+	 */
+	if (!(git_path_exists(name.ptr) &&
+		git_path_contains(&name, DOT_GIT))) {
+
+		/* resolve the actual URL to use */
+		if ((error = git_submodule_resolve_url(&real_url, repo, url)) < 0)
+			goto cleanup;
+
+		 if ((error = submodule_repo_init(&subrepo, repo, path, real_url.ptr, use_gitlink)) < 0)
+			goto cleanup;
+	}
+
+	if ((error = git_submodule_lookup(&sm, repo, path)) < 0)
+		goto cleanup;
+
+	error = git_submodule_init(sm, false);
+
+cleanup:
+	if (error && sm) {
+		git_submodule_free(sm);
+		sm = NULL;
+	}
+	if (out != NULL)
+		*out = sm;
+
+	git_config_file_free(mods);
+	git_repository_free(subrepo);
+	git_buf_free(&real_url);
+	git_buf_free(&name);
+
+	return error;
+}
+
+int git_submodule_repo_init(
+	git_repository **out,
+	const git_submodule *sm,
+	int use_gitlink)
+{
+	int error;
+	git_repository *sub_repo = NULL;
+	const char *configured_url;
+	git_config *cfg = NULL;
+	git_buf buf = GIT_BUF_INIT;
+
+	assert(out && sm);
+
+	/* get the configured remote url of the submodule */
+	if ((error = git_buf_printf(&buf, "submodule.%s.url", sm->name)) < 0 ||
+		(error = git_repository_config_snapshot(&cfg, sm->repo)) < 0 ||
+		(error = git_config_get_string(&configured_url, cfg, buf.ptr)) < 0 ||
+		(error = submodule_repo_init(&sub_repo, sm->repo, sm->path, configured_url, use_gitlink)) < 0)
+		goto done;
+
+	*out = sub_repo;
+
+done:
+	git_config_free(cfg);
+	git_buf_free(&buf);
+	return error;
+}
+
+int git_submodule_add_finalize(git_submodule *sm)
+{
+	int error;
+	git_index *index;
+
+	assert(sm);
+
+	if ((error = git_repository_index__weakptr(&index, sm->repo)) < 0 ||
+		(error = git_index_add_bypath(index, GIT_MODULES_FILE)) < 0)
+		return error;
+
+	return git_submodule_add_to_index(sm, true);
+}
+
+int git_submodule_add_to_index(git_submodule *sm, int write_index)
+{
+	int error;
+	git_repository *sm_repo = NULL;
+	git_index *index;
+	git_buf path = GIT_BUF_INIT;
+	git_commit *head;
+	git_index_entry entry;
+	struct stat st;
+
+	assert(sm);
+
+	/* force reload of wd OID by git_submodule_open */
+	sm->flags = sm->flags & ~GIT_SUBMODULE_STATUS__WD_OID_VALID;
+
+	if ((error = git_repository_index__weakptr(&index, sm->repo)) < 0 ||
+		(error = git_buf_joinpath(
+			&path, git_repository_workdir(sm->repo), sm->path)) < 0 ||
+		(error = git_submodule_open(&sm_repo, sm)) < 0)
+		goto cleanup;
+
+	/* read stat information for submodule working directory */
+	if (p_stat(path.ptr, &st) < 0) {
+		giterr_set(GITERR_SUBMODULE,
+			"cannot add submodule without working directory");
+		error = -1;
+		goto cleanup;
+	}
+
+	memset(&entry, 0, sizeof(entry));
+	entry.path = sm->path;
+	git_index_entry__init_from_stat(
+		&entry, &st, !(git_index_caps(index) & GIT_INDEXCAP_NO_FILEMODE));
+
+	/* calling git_submodule_open will have set sm->wd_oid if possible */
+	if ((sm->flags & GIT_SUBMODULE_STATUS__WD_OID_VALID) == 0) {
+		giterr_set(GITERR_SUBMODULE,
+			"cannot add submodule without HEAD to index");
+		error = -1;
+		goto cleanup;
+	}
+	git_oid_cpy(&entry.id, &sm->wd_oid);
+
+	if ((error = git_commit_lookup(&head, sm_repo, &sm->wd_oid)) < 0)
+		goto cleanup;
+
+	entry.ctime.seconds = (int32_t)git_commit_time(head);
+	entry.ctime.nanoseconds = 0;
+	entry.mtime.seconds = (int32_t)git_commit_time(head);
+	entry.mtime.nanoseconds = 0;
+
+	git_commit_free(head);
+
+	/* add it */
+	error = git_index_add(index, &entry);
+
+	/* write it, if requested */
+	if (!error && write_index) {
+		error = git_index_write(index);
+
+		if (!error)
+			git_oid_cpy(&sm->index_oid, &sm->wd_oid);
+	}
+
+cleanup:
+	git_repository_free(sm_repo);
+	git_buf_free(&path);
+	return error;
+}
+
+const char *git_submodule_update_to_str(git_submodule_update_t update)
+{
+	int i;
+	for (i = 0; i < (int)ARRAY_SIZE(_sm_update_map); ++i)
+		if (_sm_update_map[i].map_value == (int)update)
+			return _sm_update_map[i].str_match;
+	return NULL;
+}
+
+git_repository *git_submodule_owner(git_submodule *submodule)
+{
+	assert(submodule);
+	return submodule->repo;
+}
+
+const char *git_submodule_name(git_submodule *submodule)
+{
+	assert(submodule);
+	return submodule->name;
+}
+
+const char *git_submodule_path(git_submodule *submodule)
+{
+	assert(submodule);
+	return submodule->path;
+}
+
+const char *git_submodule_url(git_submodule *submodule)
+{
+	assert(submodule);
+	return submodule->url;
+}
+
+int git_submodule_resolve_url(git_buf *out, git_repository *repo, const char *url)
+{
+	int error = 0;
+	git_buf normalized = GIT_BUF_INIT;
+
+	assert(out && repo && url);
+
+	git_buf_sanitize(out);
+
+	/* We do this in all platforms in case someone on Windows created the .gitmodules */
+	if (strchr(url, '\\')) {
+		if ((error = git_path_normalize_slashes(&normalized, url)) < 0)
+			return error;
+
+		url = normalized.ptr;
+	}
+
+
+	if (git_path_is_relative(url)) {
+		if (!(error = get_url_base(out, repo)))
+			error = git_path_apply_relative(out, url);
+	} else if (strchr(url, ':') != NULL || url[0] == '/') {
+		error = git_buf_sets(out, url);
+	} else {
+		giterr_set(GITERR_SUBMODULE, "invalid format for submodule URL");
+		error = -1;
+	}
+
+	git_buf_free(&normalized);
+	return error;
+}
+
+static int write_var(git_repository *repo, const char *name, const char *var, const char *val)
+{
+	git_buf key = GIT_BUF_INIT;
+	git_config_backend *mods;
+	int error;
+
+	mods = open_gitmodules(repo, GITMODULES_CREATE);
+	if (!mods)
+		return -1;
+
+	if ((error = git_buf_printf(&key, "submodule.%s.%s", name, var)) < 0)
+		goto cleanup;
+
+	if (val)
+		error = git_config_file_set_string(mods, key.ptr, val);
+	else
+		error = git_config_file_delete(mods, key.ptr);
+
+	git_buf_free(&key);
+
+cleanup:
+	git_config_file_free(mods);
+	return error;
+}
+
+static int write_mapped_var(git_repository *repo, const char *name, git_cvar_map *maps, size_t nmaps, const char *var, int ival)
+{
+	git_cvar_t type;
+	const char *val;
+
+	if (git_config_lookup_map_enum(&type, &val, maps, nmaps, ival) < 0) {
+		giterr_set(GITERR_SUBMODULE, "invalid value for %s", var);
+		return -1;
+	}
+
+	if (type == GIT_CVAR_TRUE)
+		val = "true";
+
+	return write_var(repo, name, var, val);
+}
+
+const char *git_submodule_branch(git_submodule *submodule)
+{
+	assert(submodule);
+	return submodule->branch;
+}
+
+int git_submodule_set_branch(git_repository *repo, const char *name, const char *branch)
+{
+
+	assert(repo && name);
+
+	return write_var(repo, name, "branch", branch);
+}
+
+int git_submodule_set_url(git_repository *repo, const char *name, const char *url)
+{
+	assert(repo && name && url);
+
+	return write_var(repo, name, "url", url);
+}
+
+const git_oid *git_submodule_index_id(git_submodule *submodule)
+{
+	assert(submodule);
+
+	if (submodule->flags & GIT_SUBMODULE_STATUS__INDEX_OID_VALID)
+		return &submodule->index_oid;
+	else
+		return NULL;
+}
+
+const git_oid *git_submodule_head_id(git_submodule *submodule)
+{
+	assert(submodule);
+
+	if (submodule->flags & GIT_SUBMODULE_STATUS__HEAD_OID_VALID)
+		return &submodule->head_oid;
+	else
+		return NULL;
+}
+
+const git_oid *git_submodule_wd_id(git_submodule *submodule)
+{
+	assert(submodule);
+
+	/* load unless we think we have a valid oid */
+	if (!(submodule->flags & GIT_SUBMODULE_STATUS__WD_OID_VALID)) {
+		git_repository *subrepo;
+
+		/* calling submodule open grabs the HEAD OID if possible */
+		if (!git_submodule_open_bare(&subrepo, submodule))
+			git_repository_free(subrepo);
+		else
+			giterr_clear();
+	}
+
+	if (submodule->flags & GIT_SUBMODULE_STATUS__WD_OID_VALID)
+		return &submodule->wd_oid;
+	else
+		return NULL;
+}
+
+git_submodule_ignore_t git_submodule_ignore(git_submodule *submodule)
+{
+	assert(submodule);
+	return (submodule->ignore < GIT_SUBMODULE_IGNORE_NONE) ?
+		GIT_SUBMODULE_IGNORE_NONE : submodule->ignore;
+}
+
+int git_submodule_set_ignore(git_repository *repo, const char *name, git_submodule_ignore_t ignore)
+{
+	assert(repo && name);
+
+	return write_mapped_var(repo, name, _sm_ignore_map, ARRAY_SIZE(_sm_ignore_map), "ignore", ignore);
+}
+
+git_submodule_update_t git_submodule_update_strategy(git_submodule *submodule)
+{
+	assert(submodule);
+	return (submodule->update < GIT_SUBMODULE_UPDATE_CHECKOUT) ?
+		GIT_SUBMODULE_UPDATE_CHECKOUT : submodule->update;
+}
+
+int git_submodule_set_update(git_repository *repo, const char *name, git_submodule_update_t update)
+{
+	assert(repo && name);
+
+	return write_mapped_var(repo, name, _sm_update_map, ARRAY_SIZE(_sm_update_map), "update", update);
+}
+
+git_submodule_recurse_t git_submodule_fetch_recurse_submodules(
+	git_submodule *submodule)
+{
+	assert(submodule);
+	return submodule->fetch_recurse;
+}
+
+int git_submodule_set_fetch_recurse_submodules(git_repository *repo, const char *name, git_submodule_recurse_t recurse)
+{
+	assert(repo && name);
+
+	return write_mapped_var(repo, name, _sm_recurse_map, ARRAY_SIZE(_sm_recurse_map), "fetchRecurseSubmodules", recurse);
+}
+
+static int submodule_repo_create(
+	git_repository **out,
+	git_repository *parent_repo,
+	const char *path)
+{
+	int error = 0;
+	git_buf workdir = GIT_BUF_INIT, repodir = GIT_BUF_INIT;
+	git_repository_init_options initopt = GIT_REPOSITORY_INIT_OPTIONS_INIT;
+	git_repository *subrepo = NULL;
+
+	initopt.flags =
+		GIT_REPOSITORY_INIT_MKPATH |
+		GIT_REPOSITORY_INIT_NO_REINIT |
+		GIT_REPOSITORY_INIT_NO_DOTGIT_DIR |
+		GIT_REPOSITORY_INIT_RELATIVE_GITLINK;
+
+	/* Workdir: path to sub-repo working directory */
+	error = git_buf_joinpath(&workdir, git_repository_workdir(parent_repo), path);
+	if (error < 0)
+		goto cleanup;
+
+	initopt.workdir_path = workdir.ptr;
+
+	/**
+	 * Repodir: path to the sub-repo. sub-repo goes in:
+	 * <repo-dir>/modules/<name>/ with a gitlink in the
+	 * sub-repo workdir directory to that repository.
+	 */
+	error = git_repository_item_path(&repodir, parent_repo, GIT_REPOSITORY_ITEM_MODULES);
+	if (error < 0)
+		goto cleanup;
+	error = git_buf_joinpath(&repodir, repodir.ptr, path);
+	if (error < 0)
+		goto cleanup;
+
+	error = git_repository_init_ext(&subrepo, repodir.ptr, &initopt);
+
+cleanup:
+	git_buf_free(&workdir);
+	git_buf_free(&repodir);
+
+	*out = subrepo;
+
+	return error;
+}
+
+/**
+ * Callback to override sub-repository creation when
+ * cloning a sub-repository.
+ */
+static int git_submodule_update_repo_init_cb(
+	git_repository **out,
+	const char *path,
+	int bare,
+	void *payload)
+{
+	git_submodule *sm;
+
+	GIT_UNUSED(bare);
+
+	sm = payload;
+
+	return submodule_repo_create(out, sm->repo, path);
+}
+
+int git_submodule_update_init_options(git_submodule_update_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_submodule_update_options, GIT_SUBMODULE_UPDATE_OPTIONS_INIT);
+	return 0;
+}
+
+int git_submodule_update(git_submodule *sm, int init, git_submodule_update_options *_update_options)
+{
+	int error;
+	unsigned int submodule_status;
+	git_config *config = NULL;
+	const char *submodule_url;
+	git_repository *sub_repo = NULL;
+	git_remote *remote = NULL;
+	git_object *target_commit = NULL;
+	git_buf buf = GIT_BUF_INIT;
+	git_submodule_update_options update_options = GIT_SUBMODULE_UPDATE_OPTIONS_INIT;
+	git_clone_options clone_options = GIT_CLONE_OPTIONS_INIT;
+
+	assert(sm);
+
+	if (_update_options)
+		memcpy(&update_options, _update_options, sizeof(git_submodule_update_options));
+
+	GITERR_CHECK_VERSION(&update_options, GIT_SUBMODULE_UPDATE_OPTIONS_VERSION, "git_submodule_update_options");
+
+	/* Copy over the remote callbacks */
+	memcpy(&clone_options.fetch_opts, &update_options.fetch_opts, sizeof(git_fetch_options));
+
+	/* Get the status of the submodule to determine if it is already initialized  */
+	if ((error = git_submodule_status(&submodule_status, sm->repo, sm->name, GIT_SUBMODULE_IGNORE_UNSPECIFIED)) < 0)
+		goto done;
+
+	/*
+	 * If submodule work dir is not already initialized, check to see
+	 * what we need to do (initialize, clone, return error...)
+	 */
+	if (submodule_status & GIT_SUBMODULE_STATUS_WD_UNINITIALIZED) {
+		/*
+		 * Work dir is not initialized, check to see if the submodule
+		 * info has been copied into .git/config
+		 */
+		if ((error = git_repository_config_snapshot(&config, sm->repo)) < 0 ||
+			(error = git_buf_printf(&buf, "submodule.%s.url", git_submodule_name(sm))) < 0)
+			goto done;
+
+		if ((error = git_config_get_string(&submodule_url, config, git_buf_cstr(&buf))) < 0) {
+			/*
+			 * If the error is not "not found" or if it is "not found" and we are not
+			 * initializing the submodule, then return error.
+			 */
+			if (error != GIT_ENOTFOUND)
+				goto done;
+
+			if (!init) {
+				giterr_set(GITERR_SUBMODULE, "submodule is not initialized");
+				error = GIT_ERROR;
+				goto done;
+			}
+
+			/* The submodule has not been initialized yet - initialize it now.*/
+			if ((error = git_submodule_init(sm, 0)) < 0)
+				goto done;
+
+			git_config_free(config);
+			config = NULL;
+
+			if ((error = git_repository_config_snapshot(&config, sm->repo)) < 0 ||
+				(error = git_config_get_string(&submodule_url, config, git_buf_cstr(&buf))) < 0)
+				goto done;
+		}
+
+		/** submodule is initialized - now clone it **/
+		/* override repo creation */
+		clone_options.repository_cb = git_submodule_update_repo_init_cb;
+		clone_options.repository_cb_payload = sm;
+
+		/*
+		 * Do not perform checkout as part of clone, instead we
+		 * will checkout the specific commit manually.
+		 */
+		clone_options.checkout_opts.checkout_strategy = GIT_CHECKOUT_NONE;
+
+		if ((error = git_clone(&sub_repo, submodule_url, sm->path, &clone_options)) < 0 ||
+			(error = git_repository_set_head_detached(sub_repo, git_submodule_index_id(sm))) < 0 ||
+			(error = git_checkout_head(sub_repo, &update_options.checkout_opts)) != 0)
+			goto done;
+	} else {
+		const git_oid *oid;
+
+		/**
+		 * Work dir is initialized - look up the commit in the parent repository's index,
+		 * update the workdir contents of the subrepository, and set the subrepository's
+		 * head to the new commit.
+		 */
+		if ((error = git_submodule_open(&sub_repo, sm)) < 0)
+			goto done;
+
+		if ((oid = git_submodule_index_id(sm)) == NULL) {
+			giterr_set(GITERR_SUBMODULE, "could not get ID of submodule in index");
+			error = -1;
+			goto done;
+		}
+
+		/* Look up the target commit in the submodule. */
+		if ((error = git_object_lookup(&target_commit, sub_repo, oid, GIT_OBJ_COMMIT)) < 0) {
+			/* If it isn't found then fetch and try again. */
+			if (error != GIT_ENOTFOUND || !update_options.allow_fetch ||
+				(error = lookup_default_remote(&remote, sub_repo)) < 0 ||
+				(error = git_remote_fetch(remote, NULL, &update_options.fetch_opts, NULL)) < 0 ||
+				(error = git_object_lookup(&target_commit, sub_repo, git_submodule_index_id(sm), GIT_OBJ_COMMIT)) < 0)
+				goto done;
+		}
+
+		if ((error = git_checkout_tree(sub_repo, target_commit, &update_options.checkout_opts)) != 0 ||
+			(error = git_repository_set_head_detached(sub_repo, git_submodule_index_id(sm))) < 0)
+			goto done;
+
+		/* Invalidate the wd flags as the workdir has been updated. */
+		sm->flags = sm->flags &
+			~(GIT_SUBMODULE_STATUS_IN_WD |
+		  	GIT_SUBMODULE_STATUS__WD_OID_VALID |
+		  	GIT_SUBMODULE_STATUS__WD_SCANNED);
+	}
+
+done:
+	git_buf_free(&buf);
+	git_config_free(config);
+	git_object_free(target_commit);
+	git_remote_free(remote);
+	git_repository_free(sub_repo);
+
+	return error;
+}
+
+int git_submodule_init(git_submodule *sm, int overwrite)
+{
+	int error;
+	const char *val;
+	git_buf key = GIT_BUF_INIT, effective_submodule_url = GIT_BUF_INIT;
+	git_config *cfg = NULL;
+
+	if (!sm->url) {
+		giterr_set(GITERR_SUBMODULE,
+			"no URL configured for submodule '%s'", sm->name);
+		return -1;
+	}
+
+	if ((error = git_repository_config(&cfg, sm->repo)) < 0)
+		return error;
+
+	/* write "submodule.NAME.url" */
+
+	if ((error = git_submodule_resolve_url(&effective_submodule_url, sm->repo, sm->url)) < 0 ||
+		(error = git_buf_printf(&key, "submodule.%s.url", sm->name)) < 0 ||
+		(error = git_config__update_entry(
+			cfg, key.ptr, effective_submodule_url.ptr, overwrite != 0, false)) < 0)
+		goto cleanup;
+
+	/* write "submodule.NAME.update" if not default */
+
+	val = (sm->update == GIT_SUBMODULE_UPDATE_CHECKOUT) ?
+		NULL : git_submodule_update_to_str(sm->update);
+
+	if ((error = git_buf_printf(&key, "submodule.%s.update", sm->name)) < 0 ||
+		(error = git_config__update_entry(
+			cfg, key.ptr, val, overwrite != 0, false)) < 0)
+		goto cleanup;
+
+	/* success */
+
+cleanup:
+	git_config_free(cfg);
+	git_buf_free(&key);
+	git_buf_free(&effective_submodule_url);
+
+	return error;
+}
+
+int git_submodule_sync(git_submodule *sm)
+{
+	int error = 0;
+	git_config *cfg = NULL;
+	git_buf key = GIT_BUF_INIT;
+	git_repository *smrepo = NULL;
+
+	if (!sm->url) {
+		giterr_set(GITERR_SUBMODULE,
+			"no URL configured for submodule '%s'", sm->name);
+		return -1;
+	}
+
+	/* copy URL over to config only if it already exists */
+
+	if (!(error = git_repository_config__weakptr(&cfg, sm->repo)) &&
+		!(error = git_buf_printf(&key, "submodule.%s.url", sm->name)))
+		error = git_config__update_entry(cfg, key.ptr, sm->url, true, true);
+
+	/* if submodule exists in the working directory, update remote url */
+
+	if (!error &&
+		(sm->flags & GIT_SUBMODULE_STATUS_IN_WD) != 0 &&
+		!(error = git_submodule_open(&smrepo, sm)))
+	{
+		git_buf remote_name = GIT_BUF_INIT;
+
+		if ((error = git_repository_config__weakptr(&cfg, smrepo)) < 0)
+			/* return error from reading submodule config */;
+		else if ((error = lookup_head_remote_key(&remote_name, smrepo)) < 0) {
+			giterr_clear();
+			error = git_buf_sets(&key, "remote.origin.url");
+		} else {
+			error = git_buf_join3(
+				&key, '.', "remote", remote_name.ptr, "url");
+			git_buf_free(&remote_name);
+		}
+
+		if (!error)
+			error = git_config__update_entry(cfg, key.ptr, sm->url, true, false);
+
+		git_repository_free(smrepo);
+	}
+
+	git_buf_free(&key);
+
+	return error;
+}
+
+static int git_submodule__open(
+	git_repository **subrepo, git_submodule *sm, bool bare)
+{
+	int error;
+	git_buf path = GIT_BUF_INIT;
+	unsigned int flags = GIT_REPOSITORY_OPEN_NO_SEARCH;
+	const char *wd;
+
+	assert(sm && subrepo);
+
+	if (git_repository__ensure_not_bare(
+			sm->repo, "open submodule repository") < 0)
+		return GIT_EBAREREPO;
+
+	wd = git_repository_workdir(sm->repo);
+
+	if (git_buf_joinpath(&path, wd, sm->path) < 0 ||
+		git_buf_joinpath(&path, path.ptr, DOT_GIT) < 0)
+		return -1;
+
+	sm->flags = sm->flags &
+		~(GIT_SUBMODULE_STATUS_IN_WD |
+		  GIT_SUBMODULE_STATUS__WD_OID_VALID |
+		  GIT_SUBMODULE_STATUS__WD_SCANNED);
+
+	if (bare)
+		flags |= GIT_REPOSITORY_OPEN_BARE;
+
+	error = git_repository_open_ext(subrepo, path.ptr, flags, wd);
+
+	/* if we opened the submodule successfully, grab HEAD OID, etc. */
+	if (!error) {
+		sm->flags |= GIT_SUBMODULE_STATUS_IN_WD |
+			GIT_SUBMODULE_STATUS__WD_SCANNED;
+
+		if (!git_reference_name_to_id(&sm->wd_oid, *subrepo, GIT_HEAD_FILE))
+			sm->flags |= GIT_SUBMODULE_STATUS__WD_OID_VALID;
+		else
+			giterr_clear();
+	} else if (git_path_exists(path.ptr)) {
+		sm->flags |= GIT_SUBMODULE_STATUS__WD_SCANNED |
+			GIT_SUBMODULE_STATUS_IN_WD;
+	} else {
+		git_buf_rtruncate_at_char(&path, '/'); /* remove "/.git" */
+
+		if (git_path_isdir(path.ptr))
+			sm->flags |= GIT_SUBMODULE_STATUS__WD_SCANNED;
+	}
+
+	git_buf_free(&path);
+
+	return error;
+}
+
+int git_submodule_open_bare(git_repository **subrepo, git_submodule *sm)
+{
+	return git_submodule__open(subrepo, sm, true);
+}
+
+int git_submodule_open(git_repository **subrepo, git_submodule *sm)
+{
+	return git_submodule__open(subrepo, sm, false);
+}
+
+static void submodule_update_from_index_entry(
+	git_submodule *sm, const git_index_entry *ie)
+{
+	bool already_found = (sm->flags & GIT_SUBMODULE_STATUS_IN_INDEX) != 0;
+
+	if (!S_ISGITLINK(ie->mode)) {
+		if (!already_found)
+			sm->flags |= GIT_SUBMODULE_STATUS__INDEX_NOT_SUBMODULE;
+	} else {
+		if (already_found)
+			sm->flags |= GIT_SUBMODULE_STATUS__INDEX_MULTIPLE_ENTRIES;
+		else
+			git_oid_cpy(&sm->index_oid, &ie->id);
+
+		sm->flags |= GIT_SUBMODULE_STATUS_IN_INDEX |
+			GIT_SUBMODULE_STATUS__INDEX_OID_VALID;
+	}
+}
+
+static int submodule_update_index(git_submodule *sm)
+{
+	git_index *index;
+	const git_index_entry *ie;
+
+	if (git_repository_index__weakptr(&index, sm->repo) < 0)
+		return -1;
+
+	sm->flags = sm->flags &
+		~(GIT_SUBMODULE_STATUS_IN_INDEX |
+		  GIT_SUBMODULE_STATUS__INDEX_OID_VALID);
+
+	if (!(ie = git_index_get_bypath(index, sm->path, 0)))
+		return 0;
+
+	submodule_update_from_index_entry(sm, ie);
+
+	return 0;
+}
+
+static void submodule_update_from_head_data(
+	git_submodule *sm, mode_t mode, const git_oid *id)
+{
+	if (!S_ISGITLINK(mode))
+		sm->flags |= GIT_SUBMODULE_STATUS__HEAD_NOT_SUBMODULE;
+	else {
+		git_oid_cpy(&sm->head_oid, id);
+
+		sm->flags |= GIT_SUBMODULE_STATUS_IN_HEAD |
+			GIT_SUBMODULE_STATUS__HEAD_OID_VALID;
+	}
+}
+
+static int submodule_update_head(git_submodule *submodule)
+{
+	git_tree *head = NULL;
+	git_tree_entry *te = NULL;
+
+	submodule->flags = submodule->flags &
+		~(GIT_SUBMODULE_STATUS_IN_HEAD |
+		  GIT_SUBMODULE_STATUS__HEAD_OID_VALID);
+
+	/* if we can't look up file in current head, then done */
+	if (git_repository_head_tree(&head, submodule->repo) < 0 ||
+		git_tree_entry_bypath(&te, head, submodule->path) < 0)
+		giterr_clear();
+	else
+		submodule_update_from_head_data(submodule, te->attr, git_tree_entry_id(te));
+
+	git_tree_entry_free(te);
+	git_tree_free(head);
+	return 0;
+}
+
+int git_submodule_reload(git_submodule *sm, int force)
+{
+	int error = 0, isvalid;
+	git_config *mods;
+
+	GIT_UNUSED(force);
+
+	assert(sm);
+
+	isvalid = git_submodule_name_is_valid(sm->repo, sm->name, 0);
+	if (isvalid <= 0) {
+		/* This should come with a warning, but we've no API for that */
+		return isvalid;
+	}
+
+	if (!git_repository_is_bare(sm->repo)) {
+		/* refresh config data */
+		if ((error = gitmodules_snapshot(&mods, sm->repo)) < 0 && error != GIT_ENOTFOUND)
+			return error;
+		if (mods != NULL) {
+			error = submodule_read_config(sm, mods);
+			git_config_free(mods);
+
+			if (error < 0)
+				return error;
+		}
+
+		/* refresh wd data */
+		sm->flags &=
+			~(GIT_SUBMODULE_STATUS_IN_WD |
+			  GIT_SUBMODULE_STATUS__WD_OID_VALID |
+			  GIT_SUBMODULE_STATUS__WD_FLAGS);
+
+		error = submodule_load_from_wd_lite(sm);
+	}
+
+	if (error == 0 && (error = submodule_update_index(sm)) == 0)
+		error = submodule_update_head(sm);
+
+	return error;
+}
+
+static void submodule_copy_oid_maybe(
+	git_oid *tgt, const git_oid *src, bool valid)
+{
+	if (tgt) {
+		if (valid)
+			memcpy(tgt, src, sizeof(*tgt));
+		else
+			memset(tgt, 0, sizeof(*tgt));
+	}
+}
+
+int git_submodule__status(
+	unsigned int *out_status,
+	git_oid *out_head_id,
+	git_oid *out_index_id,
+	git_oid *out_wd_id,
+	git_submodule *sm,
+	git_submodule_ignore_t ign)
+{
+	unsigned int status;
+	git_repository *smrepo = NULL;
+
+	if (ign == GIT_SUBMODULE_IGNORE_UNSPECIFIED)
+		ign = sm->ignore;
+
+	/* only return location info if ignore == all */
+	if (ign == GIT_SUBMODULE_IGNORE_ALL) {
+		*out_status = (sm->flags & GIT_SUBMODULE_STATUS__IN_FLAGS);
+		return 0;
+	}
+
+	/* If the user has requested caching submodule state, performing these
+	 * expensive operations (especially `submodule_update_head`, which is
+	 * bottlenecked on `git_repository_head_tree`) eliminates much of the
+	 * advantage.  We will, therefore, interpret the request for caching to
+	 * apply here to and skip them.
+	 */
+
+	if (sm->repo->submodule_cache == NULL) {
+		/* refresh the index OID */
+		if (submodule_update_index(sm) < 0)
+			return -1;
+
+		/* refresh the HEAD OID */
+		if (submodule_update_head(sm) < 0)
+			return -1;
+	}
+
+	/* for ignore == dirty, don't scan the working directory */
+	if (ign == GIT_SUBMODULE_IGNORE_DIRTY) {
+		/* git_submodule_open_bare will load WD OID data */
+		if (git_submodule_open_bare(&smrepo, sm) < 0)
+			giterr_clear();
+		else
+			git_repository_free(smrepo);
+		smrepo = NULL;
+	} else if (git_submodule_open(&smrepo, sm) < 0) {
+		giterr_clear();
+		smrepo = NULL;
+	}
+
+	status = GIT_SUBMODULE_STATUS__CLEAR_INTERNAL(sm->flags);
+
+	submodule_get_index_status(&status, sm);
+	submodule_get_wd_status(&status, sm, smrepo, ign);
+
+	git_repository_free(smrepo);
+
+	*out_status = status;
+
+	submodule_copy_oid_maybe(out_head_id, &sm->head_oid,
+		(sm->flags & GIT_SUBMODULE_STATUS__HEAD_OID_VALID) != 0);
+	submodule_copy_oid_maybe(out_index_id, &sm->index_oid,
+		(sm->flags & GIT_SUBMODULE_STATUS__INDEX_OID_VALID) != 0);
+	submodule_copy_oid_maybe(out_wd_id, &sm->wd_oid,
+		(sm->flags & GIT_SUBMODULE_STATUS__WD_OID_VALID) != 0);
+
+	return 0;
+}
+
+int git_submodule_status(unsigned int *status, git_repository *repo, const char *name, git_submodule_ignore_t ignore)
+{
+	git_submodule *sm;
+	int error;
+
+	assert(status && repo && name);
+
+	if ((error = git_submodule_lookup(&sm, repo, name)) < 0)
+		return error;
+
+	error = git_submodule__status(status, NULL, NULL, NULL, sm, ignore);
+	git_submodule_free(sm);
+
+	return error;
+}
+
+int git_submodule_location(unsigned int *location, git_submodule *sm)
+{
+	assert(location && sm);
+
+	return git_submodule__status(
+		location, NULL, NULL, NULL, sm, GIT_SUBMODULE_IGNORE_ALL);
+}
+
+/*
+ * INTERNAL FUNCTIONS
+ */
+
+static int submodule_alloc(
+	git_submodule **out, git_repository *repo, const char *name)
+{
+	size_t namelen;
+	git_submodule *sm;
+
+	if (!name || !(namelen = strlen(name))) {
+		giterr_set(GITERR_SUBMODULE, "invalid submodule name");
+		return -1;
+	}
+
+	sm = git__calloc(1, sizeof(git_submodule));
+	GITERR_CHECK_ALLOC(sm);
+
+	sm->name = sm->path = git__strdup(name);
+	if (!sm->name) {
+		git__free(sm);
+		return -1;
+	}
+
+	GIT_REFCOUNT_INC(sm);
+	sm->ignore = sm->ignore_default = GIT_SUBMODULE_IGNORE_NONE;
+	sm->update = sm->update_default = GIT_SUBMODULE_UPDATE_CHECKOUT;
+	sm->fetch_recurse = sm->fetch_recurse_default = GIT_SUBMODULE_RECURSE_NO;
+	sm->repo   = repo;
+	sm->branch = NULL;
+
+	*out = sm;
+	return 0;
+}
+
+static void submodule_release(git_submodule *sm)
+{
+	if (!sm)
+		return;
+
+	if (sm->repo) {
+		sm->repo = NULL;
+	}
+
+	if (sm->path != sm->name)
+		git__free(sm->path);
+	git__free(sm->name);
+	git__free(sm->url);
+	git__free(sm->branch);
+	git__memzero(sm, sizeof(*sm));
+	git__free(sm);
+}
+
+void git_submodule_free(git_submodule *sm)
+{
+	if (!sm)
+		return;
+	GIT_REFCOUNT_DEC(sm, submodule_release);
+}
+
+static int submodule_config_error(const char *property, const char *value)
+{
+	giterr_set(GITERR_INVALID,
+		"invalid value for submodule '%s' property: '%s'", property, value);
+	return -1;
+}
+
+int git_submodule_parse_ignore(git_submodule_ignore_t *out, const char *value)
+{
+	int val;
+
+	if (git_config_lookup_map_value(
+			&val, _sm_ignore_map, ARRAY_SIZE(_sm_ignore_map), value) < 0) {
+		*out = GIT_SUBMODULE_IGNORE_NONE;
+		return submodule_config_error("ignore", value);
+	}
+
+	*out = (git_submodule_ignore_t)val;
+	return 0;
+}
+
+int git_submodule_parse_update(git_submodule_update_t *out, const char *value)
+{
+	int val;
+
+	if (git_config_lookup_map_value(
+			&val, _sm_update_map, ARRAY_SIZE(_sm_update_map), value) < 0) {
+		*out = GIT_SUBMODULE_UPDATE_CHECKOUT;
+		return submodule_config_error("update", value);
+	}
+
+	*out = (git_submodule_update_t)val;
+	return 0;
+}
+
+int git_submodule_parse_recurse(git_submodule_recurse_t *out, const char *value)
+{
+	int val;
+
+	if (git_config_lookup_map_value(
+			&val, _sm_recurse_map, ARRAY_SIZE(_sm_recurse_map), value) < 0) {
+		*out = GIT_SUBMODULE_RECURSE_YES;
+		return submodule_config_error("recurse", value);
+	}
+
+	*out = (git_submodule_recurse_t)val;
+	return 0;
+}
+
+static int get_value(const char **out, git_config *cfg, git_buf *buf, const char *name, const char *field)
+{
+	int error;
+
+	git_buf_clear(buf);
+
+	if ((error = git_buf_printf(buf, "submodule.%s.%s", name, field)) < 0 ||
+	    (error = git_config_get_string(out, cfg, buf->ptr)) < 0)
+		return error;
+
+	return error;
+}
+
+static int submodule_read_config(git_submodule *sm, git_config *cfg)
+{
+	git_buf key = GIT_BUF_INIT;
+	const char *value;
+	int error, in_config = 0;
+
+	/*
+	 * TODO: Look up path in index and if it is present but not a GITLINK
+	 * then this should be deleted (at least to match git's behavior)
+	 */
+
+	if ((error = get_value(&value, cfg, &key, sm->name, "path")) == 0) {
+		in_config = 1;
+	/*
+	 * TODO: if case insensitive filesystem, then the following strcmp
+	 * should be strcasecmp
+	 */
+		if (strcmp(sm->name, value) != 0) {
+			if (sm->path != sm->name)
+				git__free(sm->path);
+			sm->path = git__strdup(value);
+			GITERR_CHECK_ALLOC(sm->path);
+		}
+	} else if (error != GIT_ENOTFOUND) {
+		goto cleanup;
+	}
+
+	if ((error = get_value(&value, cfg, &key, sm->name, "url")) == 0) {
+		in_config = 1;
+		sm->url = git__strdup(value);
+		GITERR_CHECK_ALLOC(sm->url);
+	} else if (error != GIT_ENOTFOUND) {
+		goto cleanup;
+	}
+
+	if ((error = get_value(&value, cfg, &key, sm->name, "branch")) == 0) {
+		in_config = 1;
+		sm->branch = git__strdup(value);
+		GITERR_CHECK_ALLOC(sm->branch);
+	} else if (error != GIT_ENOTFOUND) {
+		goto cleanup;
+	}
+
+	if ((error = get_value(&value, cfg, &key, sm->name, "update")) == 0) {
+		in_config = 1;
+		if ((error = git_submodule_parse_update(&sm->update, value)) < 0)
+			goto cleanup;
+		sm->update_default = sm->update;
+	} else if (error != GIT_ENOTFOUND) {
+		goto cleanup;
+	}
+
+	if ((error = get_value(&value, cfg, &key, sm->name, "fetchRecurseSubmodules")) == 0) {
+		in_config = 1;
+		if ((error = git_submodule_parse_recurse(&sm->fetch_recurse, value)) < 0)
+			goto cleanup;
+		sm->fetch_recurse_default = sm->fetch_recurse;
+	} else if (error != GIT_ENOTFOUND) {
+		goto cleanup;
+	}
+
+	if ((error = get_value(&value, cfg, &key, sm->name, "ignore")) == 0) {
+		in_config = 1;
+		if ((error = git_submodule_parse_ignore(&sm->ignore, value)) < 0)
+			goto cleanup;
+		sm->ignore_default = sm->ignore;
+	} else if (error != GIT_ENOTFOUND) {
+		goto cleanup;
+	}
+
+	if (in_config)
+		sm->flags |= GIT_SUBMODULE_STATUS_IN_CONFIG;
+
+	error = 0;
+
+cleanup:
+	git_buf_free(&key);
+	return error;
+}
+
+static int submodule_load_each(const git_config_entry *entry, void *payload)
+{
+	lfc_data *data = payload;
+	const char *namestart, *property;
+	git_strmap_iter pos;
+	git_strmap *map = data->map;
+	git_buf name = GIT_BUF_INIT;
+	git_submodule *sm;
+	int error, isvalid;
+
+	if (git__prefixcmp(entry->name, "submodule.") != 0)
+		return 0;
+
+	namestart = entry->name + strlen("submodule.");
+	property  = strrchr(namestart, '.');
+
+	if (!property || (property == namestart))
+		return 0;
+
+	property++;
+
+	if ((error = git_buf_set(&name, namestart, property - namestart -1)) < 0)
+		return error;
+
+	isvalid = git_submodule_name_is_valid(data->repo, name.ptr, 0);
+	if (isvalid <= 0) {
+		error = isvalid;
+		goto done;
+	}
+
+	/*
+	 * Now that we have the submodule's name, we can use that to
+	 * figure out whether it's in the map. If it's not, we create
+	 * a new submodule, load the config and insert it. If it's
+	 * already inserted, we've already loaded it, so we skip.
+	 */
+	pos = git_strmap_lookup_index(map, name.ptr);
+	if (git_strmap_valid_index(map, pos)) {
+		error = 0;
+		goto done;
+	}
+
+	if ((error = submodule_alloc(&sm, data->repo, name.ptr)) < 0)
+		goto done;
+
+	if ((error = submodule_read_config(sm, data->mods)) < 0) {
+		git_submodule_free(sm);
+		goto done;
+	}
+
+	git_strmap_insert(map, sm->name, sm, &error);
+	assert(error != 0);
+	if (error < 0)
+		goto done;
+
+	error = 0;
+
+done:
+	git_buf_free(&name);
+	return error;
+}
+
+static int submodule_load_from_wd_lite(git_submodule *sm)
+{
+	git_buf path = GIT_BUF_INIT;
+
+	if (git_buf_joinpath(&path, git_repository_workdir(sm->repo), sm->path) < 0)
+		return -1;
+
+	if (git_path_isdir(path.ptr))
+		sm->flags |= GIT_SUBMODULE_STATUS__WD_SCANNED;
+
+	if (git_path_contains(&path, DOT_GIT))
+		sm->flags |= GIT_SUBMODULE_STATUS_IN_WD;
+
+	git_buf_free(&path);
+	return 0;
+}
+
+/**
+ * Requests a snapshot of $WORK_TREE/.gitmodules.
+ *
+ * Returns GIT_ENOTFOUND in case no .gitmodules file exist
+ */
+static int gitmodules_snapshot(git_config **snap, git_repository *repo)
+{
+	const char *workdir = git_repository_workdir(repo);
+	git_config *mods = NULL;
+	git_buf path = GIT_BUF_INIT;
+	int error;
+
+	if (!workdir)
+		return GIT_ENOTFOUND;
+
+	if ((error = git_buf_joinpath(&path, workdir, GIT_MODULES_FILE)) < 0)
+		return error;
+
+	if ((error = git_config_open_ondisk(&mods, path.ptr)) < 0)
+		goto cleanup;
+
+	if ((error = git_config_snapshot(snap, mods)) < 0)
+		goto cleanup;
+
+	error = 0;
+
+cleanup:
+	if (mods)
+		git_config_free(mods);
+	git_buf_free(&path);
+
+	return error;
+}
+
+static git_config_backend *open_gitmodules(
+	git_repository *repo,
+	int okay_to_create)
+{
+	const char *workdir = git_repository_workdir(repo);
+	git_buf path = GIT_BUF_INIT;
+	git_config_backend *mods = NULL;
+
+	if (workdir != NULL) {
+		if (git_buf_joinpath(&path, workdir, GIT_MODULES_FILE) != 0)
+			return NULL;
+
+		if (okay_to_create || git_path_isfile(path.ptr)) {
+			/* git_config_file__ondisk should only fail if OOM */
+			if (git_config_file__ondisk(&mods, path.ptr) < 0)
+				mods = NULL;
+			/* open should only fail here if the file is malformed */
+			else if (git_config_file_open(mods, GIT_CONFIG_LEVEL_LOCAL, repo) < 0) {
+				git_config_file_free(mods);
+				mods = NULL;
+			}
+		}
+	}
+
+	git_buf_free(&path);
+
+	return mods;
+}
+
+/* Lookup name of remote of the local tracking branch HEAD points to */
+static int lookup_head_remote_key(git_buf *remote_name, git_repository *repo)
+{
+	int error;
+	git_reference *head = NULL;
+	git_buf upstream_name = GIT_BUF_INIT;
+
+	/* lookup and dereference HEAD */
+	if ((error = git_repository_head(&head, repo)) < 0)
+		return error;
+
+	/**
+	 * If head does not refer to a branch, then return
+	 * GIT_ENOTFOUND to indicate that we could not find
+	 * a remote key for the local tracking branch HEAD points to.
+	 **/
+	if (!git_reference_is_branch(head)) {
+		giterr_set(GITERR_INVALID,
+			"HEAD does not refer to a branch.");
+		error = GIT_ENOTFOUND;
+		goto done;
+	}
+
+	/* lookup remote tracking branch of HEAD */
+	if ((error = git_branch_upstream_name(
+		&upstream_name,
+		repo,
+		git_reference_name(head))) < 0)
+		goto done;
+
+	/* lookup remote of remote tracking branch */
+	if ((error = git_branch_remote_name(remote_name, repo, upstream_name.ptr)) < 0)
+		goto done;
+
+done:
+	git_buf_free(&upstream_name);
+	git_reference_free(head);
+
+	return error;
+}
+
+/* Lookup the remote of the local tracking branch HEAD points to */
+static int lookup_head_remote(git_remote **remote, git_repository *repo)
+{
+	int error;
+	git_buf remote_name = GIT_BUF_INIT;
+
+	/* lookup remote of remote tracking branch name */
+	if (!(error = lookup_head_remote_key(&remote_name, repo)))
+		error = git_remote_lookup(remote, repo, remote_name.ptr);
+
+	git_buf_free(&remote_name);
+
+	return error;
+}
+
+/* Lookup remote, either from HEAD or fall back on origin */
+static int lookup_default_remote(git_remote **remote, git_repository *repo)
+{
+	int error = lookup_head_remote(remote, repo);
+
+	/* if that failed, use 'origin' instead */
+	if (error == GIT_ENOTFOUND)
+		error = git_remote_lookup(remote, repo, "origin");
+
+	if (error == GIT_ENOTFOUND)
+		giterr_set(
+			GITERR_SUBMODULE,
+			"cannot get default remote for submodule - no local tracking "
+			"branch for HEAD and origin does not exist");
+
+	return error;
+}
+
+static int get_url_base(git_buf *url, git_repository *repo)
+{
+	int error;
+	git_worktree *wt = NULL;
+	git_remote *remote = NULL;
+
+	if ((error = lookup_default_remote(&remote, repo)) == 0) {
+		error = git_buf_sets(url, git_remote_url(remote));
+		goto out;
+	} else if (error != GIT_ENOTFOUND)
+		goto out;
+	else
+		giterr_clear();
+
+	/* if repository does not have a default remote, use workdir instead */
+	if (git_repository_is_worktree(repo)) {
+		if ((error = git_worktree_open_from_repository(&wt, repo)) < 0)
+			goto out;
+		error = git_buf_sets(url, wt->parent_path);
+	} else
+		error = git_buf_sets(url, git_repository_workdir(repo));
+
+out:
+	git_remote_free(remote);
+	git_worktree_free(wt);
+
+	return error;
+}
+
+static void submodule_get_index_status(unsigned int *status, git_submodule *sm)
+{
+	const git_oid *head_oid  = git_submodule_head_id(sm);
+	const git_oid *index_oid = git_submodule_index_id(sm);
+
+	*status = *status & ~GIT_SUBMODULE_STATUS__INDEX_FLAGS;
+
+	if (!head_oid) {
+		if (index_oid)
+			*status |= GIT_SUBMODULE_STATUS_INDEX_ADDED;
+	}
+	else if (!index_oid)
+		*status |= GIT_SUBMODULE_STATUS_INDEX_DELETED;
+	else if (!git_oid_equal(head_oid, index_oid))
+		*status |= GIT_SUBMODULE_STATUS_INDEX_MODIFIED;
+}
+
+
+static void submodule_get_wd_status(
+	unsigned int *status,
+	git_submodule *sm,
+	git_repository *sm_repo,
+	git_submodule_ignore_t ign)
+{
+	const git_oid *index_oid = git_submodule_index_id(sm);
+	const git_oid *wd_oid =
+		(sm->flags & GIT_SUBMODULE_STATUS__WD_OID_VALID) ? &sm->wd_oid : NULL;
+	git_tree *sm_head = NULL;
+	git_index *index = NULL;
+	git_diff_options opt = GIT_DIFF_OPTIONS_INIT;
+	git_diff *diff;
+
+	*status = *status & ~GIT_SUBMODULE_STATUS__WD_FLAGS;
+
+	if (!index_oid) {
+		if (wd_oid)
+			*status |= GIT_SUBMODULE_STATUS_WD_ADDED;
+	}
+	else if (!wd_oid) {
+		if ((sm->flags & GIT_SUBMODULE_STATUS__WD_SCANNED) != 0 &&
+			(sm->flags & GIT_SUBMODULE_STATUS_IN_WD) == 0)
+			*status |= GIT_SUBMODULE_STATUS_WD_UNINITIALIZED;
+		else
+			*status |= GIT_SUBMODULE_STATUS_WD_DELETED;
+	}
+	else if (!git_oid_equal(index_oid, wd_oid))
+		*status |= GIT_SUBMODULE_STATUS_WD_MODIFIED;
+
+	/* if we have no repo, then we're done */
+	if (!sm_repo)
+		return;
+
+	/* the diffs below could be optimized with an early termination
+	 * option to the git_diff functions, but for now this is sufficient
+	 * (and certainly no worse that what core git does).
+	 */
+
+	if (ign == GIT_SUBMODULE_IGNORE_NONE)
+		opt.flags |= GIT_DIFF_INCLUDE_UNTRACKED;
+
+	(void)git_repository_index__weakptr(&index, sm_repo);
+
+	/* if we don't have an unborn head, check diff with index */
+	if (git_repository_head_tree(&sm_head, sm_repo) < 0)
+		giterr_clear();
+	else {
+		/* perform head to index diff on submodule */
+		if (git_diff_tree_to_index(&diff, sm_repo, sm_head, index, &opt) < 0)
+			giterr_clear();
+		else {
+			if (git_diff_num_deltas(diff) > 0)
+				*status |= GIT_SUBMODULE_STATUS_WD_INDEX_MODIFIED;
+			git_diff_free(diff);
+			diff = NULL;
+		}
+
+		git_tree_free(sm_head);
+	}
+
+	/* perform index-to-workdir diff on submodule */
+	if (git_diff_index_to_workdir(&diff, sm_repo, index, &opt) < 0)
+		giterr_clear();
+	else {
+		size_t untracked =
+			git_diff_num_deltas_of_type(diff, GIT_DELTA_UNTRACKED);
+
+		if (untracked > 0)
+			*status |= GIT_SUBMODULE_STATUS_WD_UNTRACKED;
+
+		if (git_diff_num_deltas(diff) != untracked)
+			*status |= GIT_SUBMODULE_STATUS_WD_WD_MODIFIED;
+
+		git_diff_free(diff);
+		diff = NULL;
+	}
+}

vendor/libgit2-sys/libgit2/src/submodule.h

diff --git a/vendor/libgit2-sys/libgit2/src/submodule.h b/vendor/libgit2-sys/libgit2/src/submodule.h
new file mode 100644
index 0000000..91a4e12
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/submodule.h
@@ -0,0 +1,164 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_submodule_h__
+#define INCLUDE_submodule_h__
+
+#include "common.h"
+
+#include "git2/submodule.h"
+#include "git2/repository.h"
+#include "fileops.h"
+
+/* Notes:
+ *
+ * Submodule information can be in four places: the index, the config files
+ * (both .git/config and .gitmodules), the HEAD tree, and the working
+ * directory.
+ *
+ * In the index:
+ * - submodule is found by path
+ * - may be missing, present, or of the wrong type
+ * - will have an oid if present
+ *
+ * In the HEAD tree:
+ * - submodule is found by path
+ * - may be missing, present, or of the wrong type
+ * - will have an oid if present
+ *
+ * In the config files:
+ * - submodule is found by submodule "name" which is usually the path
+ * - may be missing or present
+ * - will have a name, path, url, and other properties
+ *
+ * In the working directory:
+ * - submodule is found by path
+ * - may be missing, an empty directory, a checked out directory,
+ *   or of the wrong type
+ * - if checked out, will have a HEAD oid
+ * - if checked out, will have git history that can be used to compare oids
+ * - if checked out, may have modified files and/or untracked files
+ */
+
+/**
+ * Description of submodule
+ *
+ * This record describes a submodule found in a repository.  There should be
+ * an entry for every submodule found in the HEAD and index, and for every
+ * submodule described in .gitmodules.  The fields are as follows:
+ *
+ * - `rc` tracks the refcount of how many hash table entries in the
+ *   git_submodule_cache there are for this submodule.  It only comes into
+ *   play if the name and path of the submodule differ.
+ *
+ * - `name` is the name of the submodule from .gitmodules.
+ * - `path` is the path to the submodule from the repo root.  It is almost
+ *    always the same as `name`.
+ * - `url` is the url for the submodule.
+ * - `update` is a git_submodule_update_t value - see gitmodules(5) update.
+ * - `update_default` is the update value from the config
+ * - `ignore` is a git_submodule_ignore_t value - see gitmodules(5) ignore.
+ * - `ignore_default` is the ignore value from the config
+ * - `fetch_recurse` is a git_submodule_recurse_t value - see gitmodules(5)
+ *    fetchRecurseSubmodules.
+ * - `fetch_recurse_default` is the recurse value from the config
+ *
+ * - `repo` is the parent repository that contains this submodule.
+ * - `flags` after for internal use, tracking where this submodule has been
+ *   found (head, index, config, workdir) and known status info, etc.
+ * - `head_oid` is the SHA1 for the submodule path in the repo HEAD.
+ * - `index_oid` is the SHA1 for the submodule recorded in the index.
+ * - `wd_oid` is the SHA1 for the HEAD of the checked out submodule.
+ *
+ * If the submodule has been added to .gitmodules but not yet git added,
+ * then the `index_oid` will be zero but still marked valid.  If the
+ * submodule has been deleted, but the delete has not been committed yet,
+ * then the `index_oid` will be set, but the `url` will be NULL.
+ */
+struct git_submodule {
+	git_refcount rc;
+
+	/* information from config */
+	char *name;
+	char *path; /* important: may just point to "name" string */
+	char *url;
+	char *branch;
+	git_submodule_update_t update;
+	git_submodule_update_t update_default;
+	git_submodule_ignore_t ignore;
+	git_submodule_ignore_t ignore_default;
+	git_submodule_recurse_t fetch_recurse;
+	git_submodule_recurse_t fetch_recurse_default;
+
+	/* internal information */
+	git_repository *repo;
+	uint32_t flags;
+	git_oid head_oid;
+	git_oid index_oid;
+	git_oid wd_oid;
+};
+
+/* Force revalidation of submodule data cache (alloc as needed) */
+extern int git_submodule_cache_refresh(git_repository *repo);
+
+/* Release all submodules */
+extern void git_submodule_cache_free(git_repository *repo);
+
+/* Additional flags on top of public GIT_SUBMODULE_STATUS values */
+enum {
+	GIT_SUBMODULE_STATUS__WD_SCANNED          = (1u << 20),
+	GIT_SUBMODULE_STATUS__HEAD_OID_VALID      = (1u << 21),
+	GIT_SUBMODULE_STATUS__INDEX_OID_VALID     = (1u << 22),
+	GIT_SUBMODULE_STATUS__WD_OID_VALID        = (1u << 23),
+	GIT_SUBMODULE_STATUS__HEAD_NOT_SUBMODULE  = (1u << 24),
+	GIT_SUBMODULE_STATUS__INDEX_NOT_SUBMODULE = (1u << 25),
+	GIT_SUBMODULE_STATUS__WD_NOT_SUBMODULE    = (1u << 26),
+	GIT_SUBMODULE_STATUS__INDEX_MULTIPLE_ENTRIES = (1u << 27),
+};
+
+#define GIT_SUBMODULE_STATUS__CLEAR_INTERNAL(S) \
+	((S) & ~(0xFFFFFFFFu << 20))
+
+/* Internal lookup does not attempt to refresh cached data */
+extern int git_submodule__lookup(
+	git_submodule **out, git_repository *repo, const char *path);
+
+/* Internal status fn returns status and optionally the various OIDs */
+extern int git_submodule__status(
+	unsigned int *out_status,
+	git_oid *out_head_id,
+	git_oid *out_index_id,
+	git_oid *out_wd_id,
+	git_submodule *sm,
+	git_submodule_ignore_t ign);
+
+/* Open submodule repository as bare repo for quick HEAD check, etc. */
+extern int git_submodule_open_bare(
+	git_repository **repo,
+	git_submodule *submodule);
+
+extern int git_submodule_parse_ignore(
+	git_submodule_ignore_t *out, const char *value);
+extern int git_submodule_parse_update(
+	git_submodule_update_t *out, const char *value);
+
+extern int git_submodule__map(
+	git_repository *repo,
+	git_strmap *map);
+
+/**
+ * Check whether a submodule's name is valid.
+ *
+ * Check the path against the path validity rules, either the filesystem
+ * defaults (like checkout does) or whichever you want to compare against.
+ *
+ * @param repo the repository which contains the submodule
+ * @param name the name to check
+ * @param flags the `GIT_PATH` flags to use for the check (0 to use filesystem defaults)
+ */
+extern int git_submodule_name_is_valid(git_repository *repo, const char *name, int flags);
+
+#endif

vendor/libgit2-sys/libgit2/src/sysdir.c

diff --git a/vendor/libgit2-sys/libgit2/src/sysdir.c b/vendor/libgit2-sys/libgit2/src/sysdir.c
new file mode 100644
index 0000000..509b23b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/sysdir.c
@@ -0,0 +1,355 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "sysdir.h"
+
+#include "global.h"
+#include "buffer.h"
+#include "path.h"
+#include <ctype.h>
+#if GIT_WIN32
+#include "win32/findfile.h"
+#else
+#include <unistd.h>
+#include <pwd.h>
+#endif
+
+static int git_sysdir_guess_programdata_dirs(git_buf *out)
+{
+#ifdef GIT_WIN32
+	return git_win32__find_programdata_dirs(out);
+#else
+	git_buf_clear(out);
+	return 0;
+#endif
+}
+
+static int git_sysdir_guess_system_dirs(git_buf *out)
+{
+#ifdef GIT_WIN32
+	return git_win32__find_system_dirs(out, L"etc\\");
+#else
+	return git_buf_sets(out, "/etc");
+#endif
+}
+
+#ifndef GIT_WIN32
+static int get_passwd_home(git_buf *out, uid_t uid)
+{
+	struct passwd pwd, *pwdptr;
+	char *buf = NULL;
+	long buflen;
+	int error;
+
+	assert(out);
+
+	if ((buflen = sysconf(_SC_GETPW_R_SIZE_MAX)) == -1)
+		buflen = 1024;
+
+	do {
+		buf = git__realloc(buf, buflen);
+		error = getpwuid_r(uid, &pwd, buf, buflen, &pwdptr);
+		buflen *= 2;
+	} while (error == ERANGE && buflen <= 8192);
+
+	if (error) {
+		giterr_set(GITERR_OS, "failed to get passwd entry");
+		goto out;
+	}
+
+	if (!pwdptr) {
+		giterr_set(GITERR_OS, "no passwd entry found for user");
+		goto out;
+	}
+
+	if ((error = git_buf_puts(out, pwdptr->pw_dir)) < 0)
+		goto out;
+
+out:
+	git__free(buf);
+	return error;
+}
+#endif
+
+static int git_sysdir_guess_global_dirs(git_buf *out)
+{
+#ifdef GIT_WIN32
+	return git_win32__find_global_dirs(out);
+#else
+	int error;
+	uid_t uid, euid;
+
+	uid = getuid();
+	euid = geteuid();
+
+	/*
+	 * In case we are running setuid, use the configuration
+	 * of the effective user.
+	 */
+	if (uid == euid)
+	    error = git__getenv(out, "HOME");
+	else
+	    error = get_passwd_home(out, euid);
+
+	if (error == GIT_ENOTFOUND) {
+		giterr_clear();
+		error = 0;
+	}
+
+	return error;
+#endif
+}
+
+static int git_sysdir_guess_xdg_dirs(git_buf *out)
+{
+#ifdef GIT_WIN32
+	return git_win32__find_xdg_dirs(out);
+#else
+	git_buf env = GIT_BUF_INIT;
+	int error;
+	uid_t uid, euid;
+
+	uid = getuid();
+	euid = geteuid();
+
+	/*
+	 * In case we are running setuid, only look up passwd
+	 * directory of the effective user.
+	 */
+	if (uid == euid) {
+		if ((error = git__getenv(&env, "XDG_CONFIG_HOME")) == 0)
+			error = git_buf_joinpath(out, env.ptr, "git");
+
+		if (error == GIT_ENOTFOUND && (error = git__getenv(&env, "HOME")) == 0)
+			error = git_buf_joinpath(out, env.ptr, ".config/git");
+	} else {
+		if ((error = get_passwd_home(&env, euid)) == 0)
+			error = git_buf_joinpath(out, env.ptr, ".config/git");
+	}
+
+	if (error == GIT_ENOTFOUND) {
+		giterr_clear();
+		error = 0;
+	}
+
+	git_buf_free(&env);
+	return error;
+#endif
+}
+
+static int git_sysdir_guess_template_dirs(git_buf *out)
+{
+#ifdef GIT_WIN32
+	return git_win32__find_system_dirs(out, L"share\\git-core\\templates");
+#else
+	return git_buf_sets(out, "/usr/share/git-core/templates");
+#endif
+}
+
+struct git_sysdir__dir {
+	git_buf buf;
+	int (*guess)(git_buf *out);
+};
+
+static struct git_sysdir__dir git_sysdir__dirs[] = {
+	{ GIT_BUF_INIT, git_sysdir_guess_system_dirs },
+	{ GIT_BUF_INIT, git_sysdir_guess_global_dirs },
+	{ GIT_BUF_INIT, git_sysdir_guess_xdg_dirs },
+	{ GIT_BUF_INIT, git_sysdir_guess_programdata_dirs },
+	{ GIT_BUF_INIT, git_sysdir_guess_template_dirs },
+};
+
+static void git_sysdir_global_shutdown(void)
+{
+	size_t i;
+
+	for (i = 0; i < ARRAY_SIZE(git_sysdir__dirs); ++i)
+		git_buf_free(&git_sysdir__dirs[i].buf);
+}
+
+int git_sysdir_global_init(void)
+{
+	size_t i;
+	int error = 0;
+
+	for (i = 0; !error && i < ARRAY_SIZE(git_sysdir__dirs); i++)
+		error = git_sysdir__dirs[i].guess(&git_sysdir__dirs[i].buf);
+
+	git__on_shutdown(git_sysdir_global_shutdown);
+
+	return error;
+}
+
+static int git_sysdir_check_selector(git_sysdir_t which)
+{
+	if (which < ARRAY_SIZE(git_sysdir__dirs))
+		return 0;
+
+	giterr_set(GITERR_INVALID, "config directory selector out of range");
+	return -1;
+}
+
+
+int git_sysdir_get(const git_buf **out, git_sysdir_t which)
+{
+	assert(out);
+
+	*out = NULL;
+
+	GITERR_CHECK_ERROR(git_sysdir_check_selector(which));
+
+	*out = &git_sysdir__dirs[which].buf;
+	return 0;
+}
+
+int git_sysdir_get_str(
+	char *out,
+	size_t outlen,
+	git_sysdir_t which)
+{
+	const git_buf *path = NULL;
+
+	GITERR_CHECK_ERROR(git_sysdir_check_selector(which));
+	GITERR_CHECK_ERROR(git_sysdir_get(&path, which));
+
+	if (!out || path->size >= outlen) {
+		giterr_set(GITERR_NOMEMORY, "buffer is too short for the path");
+		return GIT_EBUFS;
+	}
+
+	git_buf_copy_cstr(out, outlen, path);
+	return 0;
+}
+
+#define PATH_MAGIC "$PATH"
+
+int git_sysdir_set(git_sysdir_t which, const char *search_path)
+{
+	const char *expand_path = NULL;
+	git_buf merge = GIT_BUF_INIT;
+
+	GITERR_CHECK_ERROR(git_sysdir_check_selector(which));
+
+	if (search_path != NULL)
+		expand_path = strstr(search_path, PATH_MAGIC);
+
+	/* reset the default if this path has been cleared */
+	if (!search_path)
+		git_sysdir__dirs[which].guess(&git_sysdir__dirs[which].buf);
+
+	/* if $PATH is not referenced, then just set the path */
+	if (!expand_path) {
+		if (search_path)
+			git_buf_sets(&git_sysdir__dirs[which].buf, search_path);
+
+		goto done;
+	}
+
+	/* otherwise set to join(before $PATH, old value, after $PATH) */
+	if (expand_path > search_path)
+		git_buf_set(&merge, search_path, expand_path - search_path);
+
+	if (git_buf_len(&git_sysdir__dirs[which].buf))
+		git_buf_join(&merge, GIT_PATH_LIST_SEPARATOR,
+			merge.ptr, git_sysdir__dirs[which].buf.ptr);
+
+	expand_path += strlen(PATH_MAGIC);
+	if (*expand_path)
+		git_buf_join(&merge, GIT_PATH_LIST_SEPARATOR, merge.ptr, expand_path);
+
+	git_buf_swap(&git_sysdir__dirs[which].buf, &merge);
+	git_buf_free(&merge);
+
+done:
+	if (git_buf_oom(&git_sysdir__dirs[which].buf))
+		return -1;
+
+	return 0;
+}
+
+static int git_sysdir_find_in_dirlist(
+	git_buf *path,
+	const char *name,
+	git_sysdir_t which,
+	const char *label)
+{
+	size_t len;
+	const char *scan, *next = NULL;
+	const git_buf *syspath;
+
+	GITERR_CHECK_ERROR(git_sysdir_get(&syspath, which));
+	if (!syspath || !git_buf_len(syspath))
+		goto done;
+
+	for (scan = git_buf_cstr(syspath); scan; scan = next) {
+		/* find unescaped separator or end of string */
+		for (next = scan; *next; ++next) {
+			if (*next == GIT_PATH_LIST_SEPARATOR &&
+				(next <= scan || next[-1] != '\\'))
+				break;
+		}
+
+		len = (size_t)(next - scan);
+		next = (*next ? next + 1 : NULL);
+		if (!len)
+			continue;
+
+		GITERR_CHECK_ERROR(git_buf_set(path, scan, len));
+		if (name)
+			GITERR_CHECK_ERROR(git_buf_joinpath(path, path->ptr, name));
+
+		if (git_path_exists(path->ptr))
+			return 0;
+	}
+
+done:
+	git_buf_free(path);
+	giterr_set(GITERR_OS, "the %s file '%s' doesn't exist", label, name);
+	return GIT_ENOTFOUND;
+}
+
+int git_sysdir_find_system_file(git_buf *path, const char *filename)
+{
+	return git_sysdir_find_in_dirlist(
+		path, filename, GIT_SYSDIR_SYSTEM, "system");
+}
+
+int git_sysdir_find_global_file(git_buf *path, const char *filename)
+{
+	return git_sysdir_find_in_dirlist(
+		path, filename, GIT_SYSDIR_GLOBAL, "global");
+}
+
+int git_sysdir_find_xdg_file(git_buf *path, const char *filename)
+{
+	return git_sysdir_find_in_dirlist(
+		path, filename, GIT_SYSDIR_XDG, "global/xdg");
+}
+
+int git_sysdir_find_programdata_file(git_buf *path, const char *filename)
+{
+	return git_sysdir_find_in_dirlist(
+		path, filename, GIT_SYSDIR_PROGRAMDATA, "ProgramData");
+}
+
+int git_sysdir_find_template_dir(git_buf *path)
+{
+	return git_sysdir_find_in_dirlist(
+		path, NULL, GIT_SYSDIR_TEMPLATE, "template");
+}
+
+int git_sysdir_expand_global_file(git_buf *path, const char *filename)
+{
+	int error;
+
+	if ((error = git_sysdir_find_global_file(path, NULL)) == 0) {
+		if (filename)
+			error = git_buf_joinpath(path, path->ptr, filename);
+	}
+
+	return error;
+}

vendor/libgit2-sys/libgit2/src/sysdir.h

diff --git a/vendor/libgit2-sys/libgit2/src/sysdir.h b/vendor/libgit2-sys/libgit2/src/sysdir.h
new file mode 100644
index 0000000..ce1b4dc
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/sysdir.h
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sysdir_h__
+#define INCLUDE_sysdir_h__
+
+#include "common.h"
+
+#include "posix.h"
+#include "buffer.h"
+
+/**
+ * Find a "global" file (i.e. one in a user's home directory).
+ *
+ * @param path buffer to write the full path into
+ * @param filename name of file to find in the home directory
+ * @return 0 if found, GIT_ENOTFOUND if not found, or -1 on other OS error
+ */
+extern int git_sysdir_find_global_file(git_buf *path, const char *filename);
+
+/**
+ * Find an "XDG" file (i.e. one in user's XDG config path).
+ *
+ * @param path buffer to write the full path into
+ * @param filename name of file to find in the home directory
+ * @return 0 if found, GIT_ENOTFOUND if not found, or -1 on other OS error
+ */
+extern int git_sysdir_find_xdg_file(git_buf *path, const char *filename);
+
+/**
+ * Find a "system" file (i.e. one shared for all users of the system).
+ *
+ * @param path buffer to write the full path into
+ * @param filename name of file to find in the home directory
+ * @return 0 if found, GIT_ENOTFOUND if not found, or -1 on other OS error
+ */
+extern int git_sysdir_find_system_file(git_buf *path, const char *filename);
+
+/**
+ * Find a "ProgramData" file (i.e. one in %PROGRAMDATA%)
+ *
+ * @param path buffer to write the full path into
+ * @param filename name of file to find in the ProgramData directory
+ * @return 0 if found, GIT_ENOTFOUND if not found, or -1 on other OS error
+ */
+extern int git_sysdir_find_programdata_file(git_buf *path, const char *filename);
+
+/**
+ * Find template directory.
+ *
+ * @param path buffer to write the full path into
+ * @return 0 if found, GIT_ENOTFOUND if not found, or -1 on other OS error
+ */
+extern int git_sysdir_find_template_dir(git_buf *path);
+
+/**
+ * Expand the name of a "global" file (i.e. one in a user's home
+ * directory).  Unlike `find_global_file` (above), this makes no
+ * attempt to check for the existence of the file, and is useful if
+ * you want the full path regardless of existence.
+ *
+ * @param path buffer to write the full path into
+ * @param filename name of file in the home directory
+ * @return 0 on success or -1 on error
+ */
+extern int git_sysdir_expand_global_file(git_buf *path, const char *filename);
+
+typedef enum {
+	GIT_SYSDIR_SYSTEM = 0,
+	GIT_SYSDIR_GLOBAL = 1,
+	GIT_SYSDIR_XDG    = 2,
+	GIT_SYSDIR_PROGRAMDATA = 3,
+	GIT_SYSDIR_TEMPLATE = 4,
+	GIT_SYSDIR__MAX   = 5,
+} git_sysdir_t;
+
+/**
+ * Configures global data for configuration file search paths.
+ *
+ * @return 0 on success, <0 on failure
+ */
+extern int git_sysdir_global_init(void);
+
+/**
+ * Get the search path for global/system/xdg files
+ *
+ * @param out pointer to git_buf containing search path
+ * @param which which list of paths to return
+ * @return 0 on success, <0 on failure
+ */
+extern int git_sysdir_get(const git_buf **out, git_sysdir_t which);
+
+/**
+ * Get search path into a preallocated buffer
+ *
+ * @param out String buffer to write into
+ * @param outlen Size of string buffer
+ * @param which Which search path to return
+ * @return 0 on success, GIT_EBUFS if out is too small, <0 on other failure
+ */
+
+extern int git_sysdir_get_str(char *out, size_t outlen, git_sysdir_t which);
+
+/**
+ * Set search paths for global/system/xdg files
+ *
+ * The first occurrence of the magic string "$PATH" in the new value will
+ * be replaced with the old value of the search path.
+ *
+ * @param which Which search path to modify
+ * @param paths New search path (separated by GIT_PATH_LIST_SEPARATOR)
+ * @return 0 on success, <0 on failure (allocation error)
+ */
+extern int git_sysdir_set(git_sysdir_t which, const char *paths);
+
+#endif

vendor/libgit2-sys/libgit2/src/tag.c

diff --git a/vendor/libgit2-sys/libgit2/src/tag.c b/vendor/libgit2-sys/libgit2/src/tag.c
new file mode 100644
index 0000000..445c3ff
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/tag.c
@@ -0,0 +1,517 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "tag.h"
+
+#include "commit.h"
+#include "signature.h"
+#include "message.h"
+#include "git2/object.h"
+#include "git2/repository.h"
+#include "git2/signature.h"
+#include "git2/odb_backend.h"
+
+void git_tag__free(void *_tag)
+{
+	git_tag *tag = _tag;
+	git_signature_free(tag->tagger);
+	git__free(tag->message);
+	git__free(tag->tag_name);
+	git__free(tag);
+}
+
+int git_tag_target(git_object **target, const git_tag *t)
+{
+	assert(t);
+	return git_object_lookup(target, t->object.repo, &t->target, t->type);
+}
+
+const git_oid *git_tag_target_id(const git_tag *t)
+{
+	assert(t);
+	return &t->target;
+}
+
+git_otype git_tag_target_type(const git_tag *t)
+{
+	assert(t);
+	return t->type;
+}
+
+const char *git_tag_name(const git_tag *t)
+{
+	assert(t);
+	return t->tag_name;
+}
+
+const git_signature *git_tag_tagger(const git_tag *t)
+{
+	return t->tagger;
+}
+
+const char *git_tag_message(const git_tag *t)
+{
+	assert(t);
+	return t->message;
+}
+
+static int tag_error(const char *str)
+{
+	giterr_set(GITERR_TAG, "failed to parse tag: %s", str);
+	return -1;
+}
+
+static int tag_parse(git_tag *tag, const char *buffer, const char *buffer_end)
+{
+	static const char *tag_types[] = {
+		NULL, "commit\n", "tree\n", "blob\n", "tag\n"
+	};
+
+	unsigned int i;
+	size_t text_len, alloc_len;
+	char *search;
+
+	if (git_oid__parse(&tag->target, &buffer, buffer_end, "object ") < 0)
+		return tag_error("object field invalid");
+
+	if (buffer + 5 >= buffer_end)
+		return tag_error("object too short");
+
+	if (memcmp(buffer, "type ", 5) != 0)
+		return tag_error("type field not found");
+	buffer += 5;
+
+	tag->type = GIT_OBJ_BAD;
+
+	for (i = 1; i < ARRAY_SIZE(tag_types); ++i) {
+		size_t type_length = strlen(tag_types[i]);
+
+		if (buffer + type_length >= buffer_end)
+			return tag_error("object too short");
+
+		if (memcmp(buffer, tag_types[i], type_length) == 0) {
+			tag->type = i;
+			buffer += type_length;
+			break;
+		}
+	}
+
+	if (tag->type == GIT_OBJ_BAD)
+		return tag_error("invalid object type");
+
+	if (buffer + 4 >= buffer_end)
+		return tag_error("object too short");
+
+	if (memcmp(buffer, "tag ", 4) != 0)
+		return tag_error("tag field not found");
+
+	buffer += 4;
+
+	search = memchr(buffer, '\n', buffer_end - buffer);
+	if (search == NULL)
+		return tag_error("object too short");
+
+	text_len = search - buffer;
+
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, text_len, 1);
+	tag->tag_name = git__malloc(alloc_len);
+	GITERR_CHECK_ALLOC(tag->tag_name);
+
+	memcpy(tag->tag_name, buffer, text_len);
+	tag->tag_name[text_len] = '\0';
+
+	buffer = search + 1;
+
+	tag->tagger = NULL;
+	if (buffer < buffer_end && *buffer != '\n') {
+		tag->tagger = git__malloc(sizeof(git_signature));
+		GITERR_CHECK_ALLOC(tag->tagger);
+
+		if (git_signature__parse(tag->tagger, &buffer, buffer_end, "tagger ", '\n') < 0)
+			return -1;
+	}
+
+	tag->message = NULL;
+	if (buffer < buffer_end) {
+		/* If we're not at the end of the header, search for it */
+		if( *buffer != '\n' ) {
+			search = strstr(buffer, "\n\n");
+			if (search)
+				buffer = search + 1;
+			else
+				return tag_error("tag contains no message");
+		}
+
+		text_len = buffer_end - ++buffer;
+
+		GITERR_CHECK_ALLOC_ADD(&alloc_len, text_len, 1);
+		tag->message = git__malloc(alloc_len);
+		GITERR_CHECK_ALLOC(tag->message);
+
+		memcpy(tag->message, buffer, text_len);
+		tag->message[text_len] = '\0';
+	}
+
+	return 0;
+}
+
+int git_tag__parse(void *_tag, git_odb_object *odb_obj)
+{
+	git_tag *tag = _tag;
+	const char *buffer = git_odb_object_data(odb_obj);
+	const char *buffer_end = buffer + git_odb_object_size(odb_obj);
+
+	return tag_parse(tag, buffer, buffer_end);
+}
+
+static int retrieve_tag_reference(
+	git_reference **tag_reference_out,
+	git_buf *ref_name_out,
+	git_repository *repo,
+	const char *tag_name)
+{
+	git_reference *tag_ref;
+	int error;
+
+	*tag_reference_out = NULL;
+
+	if (git_buf_joinpath(ref_name_out, GIT_REFS_TAGS_DIR, tag_name) < 0)
+		return -1;
+
+	error = git_reference_lookup(&tag_ref, repo, ref_name_out->ptr);
+	if (error < 0)
+		return error; /* Be it not foundo or corrupted */
+
+	*tag_reference_out = tag_ref;
+
+	return 0;
+}
+
+static int retrieve_tag_reference_oid(
+	git_oid *oid,
+	git_buf *ref_name_out,
+	git_repository *repo,
+	const char *tag_name)
+{
+	if (git_buf_joinpath(ref_name_out, GIT_REFS_TAGS_DIR, tag_name) < 0)
+		return -1;
+
+	return git_reference_name_to_id(oid, repo, ref_name_out->ptr);
+}
+
+static int write_tag_annotation(
+		git_oid *oid,
+		git_repository *repo,
+		const char *tag_name,
+		const git_object *target,
+		const git_signature *tagger,
+		const char *message)
+{
+	git_buf tag = GIT_BUF_INIT;
+	git_odb *odb;
+
+	git_oid__writebuf(&tag, "object ", git_object_id(target));
+	git_buf_printf(&tag, "type %s\n", git_object_type2string(git_object_type(target)));
+	git_buf_printf(&tag, "tag %s\n", tag_name);
+	git_signature__writebuf(&tag, "tagger ", tagger);
+	git_buf_putc(&tag, '\n');
+
+	if (git_buf_puts(&tag, message) < 0)
+		goto on_error;
+
+	if (git_repository_odb__weakptr(&odb, repo) < 0)
+		goto on_error;
+
+	if (git_odb_write(oid, odb, tag.ptr, tag.size, GIT_OBJ_TAG) < 0)
+		goto on_error;
+
+	git_buf_free(&tag);
+	return 0;
+
+on_error:
+	git_buf_free(&tag);
+	giterr_set(GITERR_OBJECT, "failed to create tag annotation");
+	return -1;
+}
+
+static int git_tag_create__internal(
+		git_oid *oid,
+		git_repository *repo,
+		const char *tag_name,
+		const git_object *target,
+		const git_signature *tagger,
+		const char *message,
+		int allow_ref_overwrite,
+		int create_tag_annotation)
+{
+	git_reference *new_ref = NULL;
+	git_buf ref_name = GIT_BUF_INIT;
+
+	int error;
+
+	assert(repo && tag_name && target);
+	assert(!create_tag_annotation || (tagger && message));
+
+	if (git_object_owner(target) != repo) {
+		giterr_set(GITERR_INVALID, "the given target does not belong to this repository");
+		return -1;
+	}
+
+	error = retrieve_tag_reference_oid(oid, &ref_name, repo, tag_name);
+	if (error < 0 && error != GIT_ENOTFOUND)
+		goto cleanup;
+
+	/** Ensure the tag name doesn't conflict with an already existing
+	 *	reference unless overwriting has explicitly been requested **/
+	if (error == 0 && !allow_ref_overwrite) {
+		git_buf_free(&ref_name);
+		giterr_set(GITERR_TAG, "tag already exists");
+		return GIT_EEXISTS;
+	}
+
+	if (create_tag_annotation) {
+		if (write_tag_annotation(oid, repo, tag_name, target, tagger, message) < 0)
+			return -1;
+	} else
+		git_oid_cpy(oid, git_object_id(target));
+
+	error = git_reference_create(&new_ref, repo, ref_name.ptr, oid, allow_ref_overwrite, NULL);
+
+cleanup:
+	git_reference_free(new_ref);
+	git_buf_free(&ref_name);
+	return error;
+}
+
+int git_tag_create(
+	git_oid *oid,
+	git_repository *repo,
+	const char *tag_name,
+	const git_object *target,
+	const git_signature *tagger,
+	const char *message,
+	int allow_ref_overwrite)
+{
+	return git_tag_create__internal(oid, repo, tag_name, target, tagger, message, allow_ref_overwrite, 1);
+}
+
+int git_tag_annotation_create(
+	git_oid *oid,
+	git_repository *repo,
+	const char *tag_name,
+	const git_object *target,
+	const git_signature *tagger,
+	const char *message)
+{
+	assert(oid && repo && tag_name && target && tagger && message);
+
+	return write_tag_annotation(oid, repo, tag_name, target, tagger, message);
+}
+
+int git_tag_create_lightweight(
+	git_oid *oid,
+	git_repository *repo,
+	const char *tag_name,
+	const git_object *target,
+	int allow_ref_overwrite)
+{
+	return git_tag_create__internal(oid, repo, tag_name, target, NULL, NULL, allow_ref_overwrite, 0);
+}
+
+int git_tag_create_frombuffer(git_oid *oid, git_repository *repo, const char *buffer, int allow_ref_overwrite)
+{
+	git_tag tag;
+	int error;
+	git_odb *odb;
+	git_odb_stream *stream;
+	git_odb_object *target_obj;
+
+	git_reference *new_ref = NULL;
+	git_buf ref_name = GIT_BUF_INIT;
+
+	assert(oid && buffer);
+
+	memset(&tag, 0, sizeof(tag));
+
+	if (git_repository_odb__weakptr(&odb, repo) < 0)
+		return -1;
+
+	/* validate the buffer */
+	if (tag_parse(&tag, buffer, buffer + strlen(buffer)) < 0)
+		return -1;
+
+	/* validate the target */
+	if (git_odb_read(&target_obj, odb, &tag.target) < 0)
+		goto on_error;
+
+	if (tag.type != target_obj->cached.type) {
+		giterr_set(GITERR_TAG, "the type for the given target is invalid");
+		goto on_error;
+	}
+
+	error = retrieve_tag_reference_oid(oid, &ref_name, repo, tag.tag_name);
+	if (error < 0 && error != GIT_ENOTFOUND)
+		goto on_error;
+
+	/* We don't need these objects after this */
+	git_signature_free(tag.tagger);
+	git__free(tag.tag_name);
+	git__free(tag.message);
+	git_odb_object_free(target_obj);
+
+	/** Ensure the tag name doesn't conflict with an already existing
+	 *	reference unless overwriting has explicitly been requested **/
+	if (error == 0 && !allow_ref_overwrite) {
+		giterr_set(GITERR_TAG, "tag already exists");
+		return GIT_EEXISTS;
+	}
+
+	/* write the buffer */
+	if ((error = git_odb_open_wstream(
+			&stream, odb, strlen(buffer), GIT_OBJ_TAG)) < 0)
+		return error;
+
+	if (!(error = git_odb_stream_write(stream, buffer, strlen(buffer))))
+		error = git_odb_stream_finalize_write(oid, stream);
+
+	git_odb_stream_free(stream);
+
+	if (error < 0) {
+		git_buf_free(&ref_name);
+		return error;
+	}
+
+	error = git_reference_create(
+		&new_ref, repo, ref_name.ptr, oid, allow_ref_overwrite, NULL);
+
+	git_reference_free(new_ref);
+	git_buf_free(&ref_name);
+
+	return error;
+
+on_error:
+	git_signature_free(tag.tagger);
+	git__free(tag.tag_name);
+	git__free(tag.message);
+	git_odb_object_free(target_obj);
+	return -1;
+}
+
+int git_tag_delete(git_repository *repo, const char *tag_name)
+{
+	git_reference *tag_ref;
+	git_buf ref_name = GIT_BUF_INIT;
+	int error;
+
+	error = retrieve_tag_reference(&tag_ref, &ref_name, repo, tag_name);
+
+	git_buf_free(&ref_name);
+
+	if (error < 0)
+		return error;
+
+	error = git_reference_delete(tag_ref);
+
+	git_reference_free(tag_ref);
+
+	return error;
+}
+
+typedef struct {
+	git_repository *repo;
+	git_tag_foreach_cb cb;
+	void *cb_data;
+} tag_cb_data;
+
+static int tags_cb(const char *ref, void *data)
+{
+	int error;
+	git_oid oid;
+	tag_cb_data *d = (tag_cb_data *)data;
+
+	if (git__prefixcmp(ref, GIT_REFS_TAGS_DIR) != 0)
+		return 0; /* no tag */
+
+	if (!(error = git_reference_name_to_id(&oid, d->repo, ref))) {
+		if ((error = d->cb(ref, &oid, d->cb_data)) != 0)
+			giterr_set_after_callback_function(error, "git_tag_foreach");
+	}
+
+	return error;
+}
+
+int git_tag_foreach(git_repository *repo, git_tag_foreach_cb cb, void *cb_data)
+{
+	tag_cb_data data;
+
+	assert(repo && cb);
+
+	data.cb = cb;
+	data.cb_data = cb_data;
+	data.repo = repo;
+
+	return git_reference_foreach_name(repo, &tags_cb, &data);
+}
+
+typedef struct {
+	git_vector *taglist;
+	const char *pattern;
+} tag_filter_data;
+
+#define GIT_REFS_TAGS_DIR_LEN strlen(GIT_REFS_TAGS_DIR)
+
+static int tag_list_cb(const char *tag_name, git_oid *oid, void *data)
+{
+	tag_filter_data *filter = (tag_filter_data *)data;
+	GIT_UNUSED(oid);
+
+	if (!*filter->pattern ||
+		p_fnmatch(filter->pattern, tag_name + GIT_REFS_TAGS_DIR_LEN, 0) == 0)
+	{
+		char *matched = git__strdup(tag_name + GIT_REFS_TAGS_DIR_LEN);
+		GITERR_CHECK_ALLOC(matched);
+
+		return git_vector_insert(filter->taglist, matched);
+	}
+
+	return 0;
+}
+
+int git_tag_list_match(git_strarray *tag_names, const char *pattern, git_repository *repo)
+{
+	int error;
+	tag_filter_data filter;
+	git_vector taglist;
+
+	assert(tag_names && repo && pattern);
+
+	if ((error = git_vector_init(&taglist, 8, NULL)) < 0)
+		return error;
+
+	filter.taglist = &taglist;
+	filter.pattern = pattern;
+
+	error = git_tag_foreach(repo, &tag_list_cb, (void *)&filter);
+
+	if (error < 0)
+		git_vector_free(&taglist);
+
+	tag_names->strings =
+		(char **)git_vector_detach(&tag_names->count, NULL, &taglist);
+
+	return 0;
+}
+
+int git_tag_list(git_strarray *tag_names, git_repository *repo)
+{
+	return git_tag_list_match(tag_names, "", repo);
+}
+
+int git_tag_peel(git_object **tag_target, const git_tag *tag)
+{
+	return git_object_peel(tag_target, (const git_object *)tag, GIT_OBJ_ANY);
+}

vendor/libgit2-sys/libgit2/src/tag.h

diff --git a/vendor/libgit2-sys/libgit2/src/tag.h b/vendor/libgit2-sys/libgit2/src/tag.h
new file mode 100644
index 0000000..8aae378
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/tag.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_tag_h__
+#define INCLUDE_tag_h__
+
+#include "common.h"
+
+#include "git2/tag.h"
+#include "repository.h"
+#include "odb.h"
+
+struct git_tag {
+	git_object object;
+
+	git_oid target;
+	git_otype type;
+
+	char *tag_name;
+	git_signature *tagger;
+	char *message;
+};
+
+void git_tag__free(void *tag);
+int git_tag__parse(void *tag, git_odb_object *obj);
+
+#endif

vendor/libgit2-sys/libgit2/src/thread-utils.c

diff --git a/vendor/libgit2-sys/libgit2/src/thread-utils.c b/vendor/libgit2-sys/libgit2/src/thread-utils.c
new file mode 100644
index 0000000..e5ec6a8
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/thread-utils.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+#include "thread-utils.h"
+
+#ifdef _WIN32
+#ifndef WIN32_LEAN_AND_MEAN
+#	define WIN32_LEAN_AND_MEAN
+#endif
+#	include <windows.h>
+#elif defined(hpux) || defined(__hpux) || defined(_hpux)
+#	include <sys/pstat.h>
+#endif
+
+/*
+ * By doing this in two steps we can at least get
+ * the function to be somewhat coherent, even
+ * with this disgusting nest of #ifdefs.
+ */
+#ifndef _SC_NPROCESSORS_ONLN
+#	ifdef _SC_NPROC_ONLN
+#		define _SC_NPROCESSORS_ONLN _SC_NPROC_ONLN
+#	elif defined _SC_CRAY_NCPU
+#		define _SC_NPROCESSORS_ONLN _SC_CRAY_NCPU
+#	endif
+#endif
+
+int git_online_cpus(void)
+{
+#ifdef _SC_NPROCESSORS_ONLN
+	long ncpus;
+#endif
+
+#ifdef _WIN32
+	SYSTEM_INFO info;
+	GetSystemInfo(&info);
+
+	if ((int)info.dwNumberOfProcessors > 0)
+		return (int)info.dwNumberOfProcessors;
+#elif defined(hpux) || defined(__hpux) || defined(_hpux)
+	struct pst_dynamic psd;
+
+	if (!pstat_getdynamic(&psd, sizeof(psd), (size_t)1, 0))
+		return (int)psd.psd_proc_cnt;
+#endif
+
+#ifdef _SC_NPROCESSORS_ONLN
+	if ((ncpus = (long)sysconf(_SC_NPROCESSORS_ONLN)) > 0)
+		return (int)ncpus;
+#endif
+
+	return 1;
+}

vendor/libgit2-sys/libgit2/src/thread-utils.h

diff --git a/vendor/libgit2-sys/libgit2/src/thread-utils.h b/vendor/libgit2-sys/libgit2/src/thread-utils.h
new file mode 100644
index 0000000..035de69
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/thread-utils.h
@@ -0,0 +1,246 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_thread_utils_h__
+#define INCLUDE_thread_utils_h__
+
+#if defined(__GNUC__) && defined(GIT_THREADS)
+# if (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 1))
+#  error Atomic primitives do not exist on this version of gcc; configure libgit2 with -DTHREADSAFE=OFF
+# endif
+#endif
+
+/* Common operations even if threading has been disabled */
+typedef struct {
+#if defined(GIT_WIN32)
+	volatile long val;
+#else
+	volatile int val;
+#endif
+} git_atomic;
+
+#ifdef GIT_ARCH_64
+
+typedef struct {
+#if defined(GIT_WIN32)
+	__int64 val;
+#else
+	int64_t val;
+#endif
+} git_atomic64;
+
+typedef git_atomic64 git_atomic_ssize;
+
+#define git_atomic_ssize_add git_atomic64_add
+
+#else
+
+typedef git_atomic git_atomic_ssize;
+
+#define git_atomic_ssize_add git_atomic_add
+
+#endif
+
+#ifdef GIT_THREADS
+
+#ifdef GIT_WIN32
+#   include "win32/thread.h"
+#else
+#   include "unix/pthread.h"
+#endif
+
+GIT_INLINE(void) git_atomic_set(git_atomic *a, int val)
+{
+#if defined(GIT_WIN32)
+	InterlockedExchange(&a->val, (LONG)val);
+#elif defined(__GNUC__)
+	__sync_lock_test_and_set(&a->val, val);
+#else
+#	error "Unsupported architecture for atomic operations"
+#endif
+}
+
+GIT_INLINE(int) git_atomic_inc(git_atomic *a)
+{
+#if defined(GIT_WIN32)
+	return InterlockedIncrement(&a->val);
+#elif defined(__GNUC__)
+	return __sync_add_and_fetch(&a->val, 1);
+#else
+#	error "Unsupported architecture for atomic operations"
+#endif
+}
+
+GIT_INLINE(int) git_atomic_add(git_atomic *a, int32_t addend)
+{
+#if defined(GIT_WIN32)
+	return InterlockedExchangeAdd(&a->val, addend);
+#elif defined(__GNUC__)
+	return __sync_add_and_fetch(&a->val, addend);
+#else
+#	error "Unsupported architecture for atomic operations"
+#endif
+}
+
+GIT_INLINE(int) git_atomic_dec(git_atomic *a)
+{
+#if defined(GIT_WIN32)
+	return InterlockedDecrement(&a->val);
+#elif defined(__GNUC__)
+	return __sync_sub_and_fetch(&a->val, 1);
+#else
+#	error "Unsupported architecture for atomic operations"
+#endif
+}
+
+GIT_INLINE(void *) git___compare_and_swap(
+	void * volatile *ptr, void *oldval, void *newval)
+{
+	volatile void *foundval;
+#if defined(GIT_WIN32)
+	foundval = InterlockedCompareExchangePointer((volatile PVOID *)ptr, newval, oldval);
+#elif defined(__GNUC__)
+	foundval = __sync_val_compare_and_swap(ptr, oldval, newval);
+#else
+#	error "Unsupported architecture for atomic operations"
+#endif
+	return (foundval == oldval) ? oldval : newval;
+}
+
+GIT_INLINE(volatile void *) git___swap(
+	void * volatile *ptr, void *newval)
+{
+#if defined(GIT_WIN32)
+	return InterlockedExchangePointer(ptr, newval);
+#else
+	return __sync_lock_test_and_set(ptr, newval);
+#endif
+}
+
+#ifdef GIT_ARCH_64
+
+GIT_INLINE(int64_t) git_atomic64_add(git_atomic64 *a, int64_t addend)
+{
+#if defined(GIT_WIN32)
+	return InterlockedExchangeAdd64(&a->val, addend);
+#elif defined(__GNUC__)
+	return __sync_add_and_fetch(&a->val, addend);
+#else
+#	error "Unsupported architecture for atomic operations"
+#endif
+}
+
+#endif
+
+#else
+
+#define git_thread unsigned int
+#define git_thread_create(thread, start_routine, arg) 0
+#define git_thread_join(id, status) (void)0
+
+/* Pthreads Mutex */
+#define git_mutex unsigned int
+GIT_INLINE(int) git_mutex_init(git_mutex *mutex) \
+	{ GIT_UNUSED(mutex); return 0; }
+GIT_INLINE(int) git_mutex_lock(git_mutex *mutex) \
+	{ GIT_UNUSED(mutex); return 0; }
+#define git_mutex_unlock(a) (void)0
+#define git_mutex_free(a) (void)0
+
+/* Pthreads condition vars */
+#define git_cond unsigned int
+#define git_cond_init(c, a)	(void)0
+#define git_cond_free(c) (void)0
+#define git_cond_wait(c, l)	(void)0
+#define git_cond_signal(c) (void)0
+#define git_cond_broadcast(c) (void)0
+
+/* Pthreads rwlock */
+#define git_rwlock unsigned int
+#define git_rwlock_init(a)		0
+#define git_rwlock_rdlock(a)	0
+#define git_rwlock_rdunlock(a)	(void)0
+#define git_rwlock_wrlock(a)	0
+#define git_rwlock_wrunlock(a)	(void)0
+#define git_rwlock_free(a)		(void)0
+#define GIT_RWLOCK_STATIC_INIT	0
+
+
+GIT_INLINE(void) git_atomic_set(git_atomic *a, int val)
+{
+	a->val = val;
+}
+
+GIT_INLINE(int) git_atomic_inc(git_atomic *a)
+{
+	return ++a->val;
+}
+
+GIT_INLINE(int) git_atomic_add(git_atomic *a, int32_t addend)
+{
+	a->val += addend;
+	return a->val;
+}
+
+GIT_INLINE(int) git_atomic_dec(git_atomic *a)
+{
+	return --a->val;
+}
+
+GIT_INLINE(void *) git___compare_and_swap(
+	void * volatile *ptr, void *oldval, void *newval)
+{
+	if (*ptr == oldval)
+		*ptr = newval;
+	else
+		oldval = newval;
+	return oldval;
+}
+
+GIT_INLINE(volatile void *) git___swap(
+	void * volatile *ptr, void *newval)
+{
+	volatile void *old = *ptr;
+	*ptr = newval;
+	return old;
+}
+
+#ifdef GIT_ARCH_64
+
+GIT_INLINE(int64_t) git_atomic64_add(git_atomic64 *a, int64_t addend)
+{
+	a->val += addend;
+	return a->val;
+}
+
+#endif
+
+#endif
+
+GIT_INLINE(int) git_atomic_get(git_atomic *a)
+{
+	return (int)a->val;
+}
+
+/* Atomically replace oldval with newval
+ * @return oldval if it was replaced or newval if it was not
+ */
+#define git__compare_and_swap(P,O,N) \
+	git___compare_and_swap((void * volatile *)P, O, N)
+
+#define git__swap(ptr, val) (void *)git___swap((void * volatile *)&ptr, val)
+
+extern int git_online_cpus(void);
+
+#if defined(GIT_THREADS) && defined(_MSC_VER)
+# define GIT_MEMORY_BARRIER MemoryBarrier()
+#elif defined(GIT_THREADS)
+# define GIT_MEMORY_BARRIER __sync_synchronize()
+#else
+# define GIT_MEMORY_BARRIER /* noop */
+#endif
+
+#endif

vendor/libgit2-sys/libgit2/src/trace.c

diff --git a/vendor/libgit2-sys/libgit2/src/trace.c b/vendor/libgit2-sys/libgit2/src/trace.c
new file mode 100644
index 0000000..080d1e8
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/trace.c
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "trace.h"
+
+#include "buffer.h"
+#include "global.h"
+#include "git2/trace.h"
+
+#ifdef GIT_TRACE
+
+struct git_trace_data git_trace__data = {0};
+
+#endif
+
+int git_trace_set(git_trace_level_t level, git_trace_callback callback)
+{
+#ifdef GIT_TRACE
+	assert(level == 0 || callback != NULL);
+
+	git_trace__data.level = level;
+	git_trace__data.callback = callback;
+	GIT_MEMORY_BARRIER;
+
+	return 0;
+#else
+	GIT_UNUSED(level);
+	GIT_UNUSED(callback);
+
+	giterr_set(GITERR_INVALID,
+		"this version of libgit2 was not built with tracing.");
+	return -1;
+#endif
+}

vendor/libgit2-sys/libgit2/src/trace.h

diff --git a/vendor/libgit2-sys/libgit2/src/trace.h b/vendor/libgit2-sys/libgit2/src/trace.h
new file mode 100644
index 0000000..4989440
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/trace.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_trace_h__
+#define INCLUDE_trace_h__
+
+#include "common.h"
+
+#include <git2/trace.h>
+#include "buffer.h"
+
+#ifdef GIT_TRACE
+
+struct git_trace_data {
+	git_trace_level_t level;
+	git_trace_callback callback;
+};
+
+extern struct git_trace_data git_trace__data;
+
+GIT_INLINE(void) git_trace__write_fmt(
+	git_trace_level_t level,
+	const char *fmt, ...)
+{
+	git_trace_callback callback = git_trace__data.callback;
+	git_buf message = GIT_BUF_INIT;
+	va_list ap;
+
+	va_start(ap, fmt);
+	git_buf_vprintf(&message, fmt, ap);
+	va_end(ap);
+
+	callback(level, git_buf_cstr(&message));
+
+	git_buf_free(&message);
+}
+
+#define git_trace_level()		(git_trace__data.level)
+#define git_trace(l, ...)		{ \
+									if (git_trace__data.level >= l && \
+										git_trace__data.callback != NULL) { \
+										git_trace__write_fmt(l, __VA_ARGS__); \
+									} \
+								}
+
+#else
+
+GIT_INLINE(void) git_trace__null(
+	git_trace_level_t level,
+	const char *fmt, ...)
+{
+	GIT_UNUSED(level);
+	GIT_UNUSED(fmt);
+}
+
+#define git_trace_level()		((void)0)
+#define git_trace			git_trace__null
+
+#endif
+
+#endif

vendor/libgit2-sys/libgit2/src/trailer.c

diff --git a/vendor/libgit2-sys/libgit2/src/trailer.c b/vendor/libgit2-sys/libgit2/src/trailer.c
new file mode 100644
index 0000000..24c8847
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/trailer.c
@@ -0,0 +1,416 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#include "array.h"
+#include "common.h"
+#include "git2/message.h"
+
+#include <stddef.h>
+#include <string.h>
+#include <ctype.h>
+
+#define COMMENT_LINE_CHAR '#'
+#define TRAILER_SEPARATORS ":"
+
+static const char *const git_generated_prefixes[] = {
+	"Signed-off-by: ",
+	"(cherry picked from commit ",
+	NULL
+};
+
+static int is_blank_line(const char *str)
+{
+	const char *s = str;
+	while (*s && *s != '\n' && isspace(*s))
+		s++;
+	return !*s || *s == '\n';
+}
+
+static const char *next_line(const char *str)
+{
+	const char *nl = strchr(str, '\n');
+
+	if (nl) {
+		return nl + 1;
+	} else {
+		// return pointer to the NUL terminator:
+		return str + strlen(str);
+	}
+}
+
+/*
+ * Return the position of the start of the last line. If len is 0, return -1.
+ */
+static int last_line(const char *buf, size_t len)
+{
+	int i;
+	if (len == 0)
+		return -1;
+	if (len == 1)
+		return 0;
+	/*
+	 * Skip the last character (in addition to the null terminator),
+	 * because if the last character is a newline, it is considered as part
+	 * of the last line anyway.
+	 */
+	i = len - 2;
+
+	for (; i >= 0; i--) {
+		if (buf[i] == '\n')
+			return i + 1;
+	}
+	return 0;
+}
+
+/*
+ * If the given line is of the form
+ * "<token><optional whitespace><separator>..." or "<separator>...", return the
+ * location of the separator. Otherwise, return -1.  The optional whitespace
+ * is allowed there primarily to allow things like "Bug #43" where <token> is
+ * "Bug" and <separator> is "#".
+ *
+ * The separator-starts-line case (in which this function returns 0) is
+ * distinguished from the non-well-formed-line case (in which this function
+ * returns -1) because some callers of this function need such a distinction.
+ */
+static int find_separator(const char *line, const char *separators)
+{
+	int whitespace_found = 0;
+	const char *c;
+	for (c = line; *c; c++) {
+		if (strchr(separators, *c))
+			return c - line;
+		if (!whitespace_found && (isalnum(*c) || *c == '-'))
+			continue;
+		if (c != line && (*c == ' ' || *c == '\t')) {
+			whitespace_found = 1;
+			continue;
+		}
+		break;
+	}
+	return -1;
+}
+
+/*
+ * Inspect the given string and determine the true "end" of the log message, in
+ * order to find where to put a new Signed-off-by: line.  Ignored are
+ * trailing comment lines and blank lines.  To support "git commit -s
+ * --amend" on an existing commit, we also ignore "Conflicts:".  To
+ * support "git commit -v", we truncate at cut lines.
+ *
+ * Returns the number of bytes from the tail to ignore, to be fed as
+ * the second parameter to append_signoff().
+ */
+static int ignore_non_trailer(const char *buf, size_t len)
+{
+	int boc = 0;
+	size_t bol = 0;
+	int in_old_conflicts_block = 0;
+	size_t cutoff = len;
+
+	while (bol < cutoff) {
+		const char *next_line = memchr(buf + bol, '\n', len - bol);
+
+		if (!next_line)
+			next_line = buf + len;
+		else
+			next_line++;
+
+		if (buf[bol] == COMMENT_LINE_CHAR || buf[bol] == '\n') {
+			/* is this the first of the run of comments? */
+			if (!boc)
+				boc = bol;
+			/* otherwise, it is just continuing */
+		} else if (git__prefixcmp(buf + bol, "Conflicts:\n") == 0) {
+			in_old_conflicts_block = 1;
+			if (!boc)
+				boc = bol;
+		} else if (in_old_conflicts_block && buf[bol] == '\t') {
+			; /* a pathname in the conflicts block */
+		} else if (boc) {
+			/* the previous was not trailing comment */
+			boc = 0;
+			in_old_conflicts_block = 0;
+		}
+		bol = next_line - buf;
+	}
+	return boc ? len - boc : len - cutoff;
+}
+
+/*
+ * Return the position of the start of the patch or the length of str if there
+ * is no patch in the message.
+ */
+static int find_patch_start(const char *str)
+{
+	const char *s;
+
+	for (s = str; *s; s = next_line(s)) {
+		if (git__prefixcmp(s, "---") == 0)
+			return s - str;
+	}
+
+	return s - str;
+}
+
+/*
+ * Return the position of the first trailer line or len if there are no
+ * trailers.
+ */
+static int find_trailer_start(const char *buf, size_t len)
+{
+	const char *s;
+	int end_of_title, l, only_spaces = 1;
+	int recognized_prefix = 0, trailer_lines = 0, non_trailer_lines = 0;
+	/*
+	 * Number of possible continuation lines encountered. This will be
+	 * reset to 0 if we encounter a trailer (since those lines are to be
+	 * considered continuations of that trailer), and added to
+	 * non_trailer_lines if we encounter a non-trailer (since those lines
+	 * are to be considered non-trailers).
+	 */
+	int possible_continuation_lines = 0;
+
+	/* The first paragraph is the title and cannot be trailers */
+	for (s = buf; s < buf + len; s = next_line(s)) {
+		if (s[0] == COMMENT_LINE_CHAR)
+			continue;
+		if (is_blank_line(s))
+			break;
+	}
+	end_of_title = s - buf;
+
+	/*
+	 * Get the start of the trailers by looking starting from the end for a
+	 * blank line before a set of non-blank lines that (i) are all
+	 * trailers, or (ii) contains at least one Git-generated trailer and
+	 * consists of at least 25% trailers.
+	 */
+	for (l = last_line(buf, len);
+	     l >= end_of_title;
+	     l = last_line(buf, l)) {
+		const char *bol = buf + l;
+		const char *const *p;
+		int separator_pos;
+
+		if (bol[0] == COMMENT_LINE_CHAR) {
+			non_trailer_lines += possible_continuation_lines;
+			possible_continuation_lines = 0;
+			continue;
+		}
+		if (is_blank_line(bol)) {
+			if (only_spaces)
+				continue;
+			non_trailer_lines += possible_continuation_lines;
+			if (recognized_prefix &&
+			    trailer_lines * 3 >= non_trailer_lines)
+				return next_line(bol) - buf;
+			else if (trailer_lines && !non_trailer_lines)
+				return next_line(bol) - buf;
+			return len;
+		}
+		only_spaces = 0;
+
+		for (p = git_generated_prefixes; *p; p++) {
+			if (git__prefixcmp(bol, *p) == 0) {
+				trailer_lines++;
+				possible_continuation_lines = 0;
+				recognized_prefix = 1;
+				goto continue_outer_loop;
+			}
+		}
+
+		separator_pos = find_separator(bol, TRAILER_SEPARATORS);
+		if (separator_pos >= 1 && !isspace(bol[0])) {
+			trailer_lines++;
+			possible_continuation_lines = 0;
+			if (recognized_prefix)
+				continue;
+		} else if (isspace(bol[0]))
+			possible_continuation_lines++;
+		else {
+			non_trailer_lines++;
+			non_trailer_lines += possible_continuation_lines;
+			possible_continuation_lines = 0;
+		}
+continue_outer_loop:
+		;
+	}
+
+	return len;
+}
+
+/* Return the position of the end of the trailers. */
+static int find_trailer_end(const char *buf, size_t len)
+{
+	return len - ignore_non_trailer(buf, len);
+}
+
+static char *extract_trailer_block(const char *message, size_t* len)
+{
+	size_t patch_start = find_patch_start(message);
+	size_t trailer_end = find_trailer_end(message, patch_start);
+	size_t trailer_start = find_trailer_start(message, trailer_end);
+
+	size_t trailer_len = trailer_end - trailer_start;
+
+	char *buffer = git__malloc(trailer_len + 1);
+	memcpy(buffer, message + trailer_start, trailer_len);
+	buffer[trailer_len] = 0;
+
+	*len = trailer_len;
+
+	return buffer;
+}
+
+enum trailer_state {
+	S_START = 0,
+	S_KEY = 1,
+	S_KEY_WS = 2,
+	S_SEP_WS = 3,
+	S_VALUE = 4,
+	S_VALUE_NL = 5,
+	S_VALUE_END = 6,
+	S_IGNORE = 7,
+};
+
+#define NEXT(st) { state = (st); ptr++; continue; }
+#define GOTO(st) { state = (st); continue; }
+
+typedef git_array_t(git_message_trailer) git_array_trailer_t;
+
+int git_message_trailers(git_message_trailer_array *trailer_arr, const char *message)
+{
+	enum trailer_state state = S_START;
+	int rc = 0;
+	char *ptr;
+	char *key = NULL;
+	char *value = NULL;
+	git_array_trailer_t arr = GIT_ARRAY_INIT;
+
+	size_t trailer_len;
+	char *trailer = extract_trailer_block(message, &trailer_len);
+
+	for (ptr = trailer;;) {
+		switch (state) {
+			case S_START: {
+				if (*ptr == 0) {
+					goto ret;
+				}
+
+				key = ptr;
+				GOTO(S_KEY);
+			}
+			case S_KEY: {
+				if (*ptr == 0) {
+					goto ret;
+				}
+
+				if (isalnum(*ptr) || *ptr == '-') {
+					// legal key character
+					NEXT(S_KEY);
+				}
+
+				if (*ptr == ' ' || *ptr == '\t') {
+					// optional whitespace before separator
+					*ptr = 0;
+					NEXT(S_KEY_WS);
+				}
+
+				if (strchr(TRAILER_SEPARATORS, *ptr)) {
+					*ptr = 0;
+					NEXT(S_SEP_WS);
+				}
+
+				// illegal character
+				GOTO(S_IGNORE);
+			}
+			case S_KEY_WS: {
+				if (*ptr == 0) {
+					goto ret;
+				}
+
+				if (*ptr == ' ' || *ptr == '\t') {
+					NEXT(S_KEY_WS);
+				}
+
+				if (strchr(TRAILER_SEPARATORS, *ptr)) {
+					NEXT(S_SEP_WS);
+				}
+
+				// illegal character
+				GOTO(S_IGNORE);
+			}
+			case S_SEP_WS: {
+				if (*ptr == 0) {
+					goto ret;
+				}
+
+				if (*ptr == ' ' || *ptr == '\t') {
+					NEXT(S_SEP_WS);
+				}
+
+				value = ptr;
+				NEXT(S_VALUE);
+			}
+			case S_VALUE: {
+				if (*ptr == 0) {
+					GOTO(S_VALUE_END);
+				}
+
+				if (*ptr == '\n') {
+					NEXT(S_VALUE_NL);
+				}
+
+				NEXT(S_VALUE);
+			}
+			case S_VALUE_NL: {
+				if (*ptr == ' ') {
+					// continuation;
+					NEXT(S_VALUE);
+				}
+
+				ptr[-1] = 0;
+				GOTO(S_VALUE_END);
+			}
+			case S_VALUE_END: {
+				git_message_trailer *t = git_array_alloc(arr);
+
+				t->key = key;
+				t->value = value;
+
+				key = NULL;
+				value = NULL;
+
+				GOTO(S_START);
+			}
+			case S_IGNORE: {
+				if (*ptr == 0) {
+					goto ret;
+				}
+
+				if (*ptr == '\n') {
+					NEXT(S_START);
+				}
+
+				NEXT(S_IGNORE);
+			}
+		}
+	}
+
+ret:
+	trailer_arr->_trailer_block = trailer;
+	trailer_arr->trailers = arr.ptr;
+	trailer_arr->count = arr.size;
+
+	return rc;
+}
+
+void git_message_trailer_array_free(git_message_trailer_array *arr)
+{
+	git__free(arr->_trailer_block);
+	git__free(arr->trailers);
+}

vendor/libgit2-sys/libgit2/src/transaction.c

diff --git a/vendor/libgit2-sys/libgit2/src/transaction.c b/vendor/libgit2-sys/libgit2/src/transaction.c
new file mode 100644
index 0000000..675023a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transaction.c
@@ -0,0 +1,382 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "transaction.h"
+
+#include "repository.h"
+#include "strmap.h"
+#include "refdb.h"
+#include "pool.h"
+#include "reflog.h"
+#include "signature.h"
+#include "config.h"
+
+#include "git2/transaction.h"
+#include "git2/signature.h"
+#include "git2/sys/refs.h"
+#include "git2/sys/refdb_backend.h"
+
+typedef enum {
+	TRANSACTION_NONE,
+	TRANSACTION_REFS,
+	TRANSACTION_CONFIG,
+} transaction_t;
+
+typedef struct {
+	const char *name;
+	void *payload;
+
+	git_ref_t ref_type;
+	union {
+		git_oid id;
+		char *symbolic;
+	} target;
+	git_reflog *reflog;
+
+	const char *message;
+	git_signature *sig;
+
+	unsigned int committed :1,
+		remove :1;
+} transaction_node;
+
+struct git_transaction {
+	transaction_t type;
+	git_repository *repo;
+	git_refdb *db;
+	git_config *cfg;
+
+	git_strmap *locks;
+	git_pool pool;
+};
+
+int git_transaction_config_new(git_transaction **out, git_config *cfg)
+{
+	git_transaction *tx;
+	assert(out && cfg);
+
+	tx = git__calloc(1, sizeof(git_transaction));
+	GITERR_CHECK_ALLOC(tx);
+
+	tx->type = TRANSACTION_CONFIG;
+	tx->cfg = cfg;
+	*out = tx;
+	return 0;
+}
+
+int git_transaction_new(git_transaction **out, git_repository *repo)
+{
+	int error;
+	git_pool pool;
+	git_transaction *tx = NULL;
+
+	assert(out && repo);
+
+	git_pool_init(&pool, 1);
+
+	tx = git_pool_mallocz(&pool, sizeof(git_transaction));
+	if (!tx) {
+		error = -1;
+		goto on_error;
+	}
+
+	if ((error = git_strmap_alloc(&tx->locks)) < 0) {
+		error = -1;
+		goto on_error;
+	}
+
+	if ((error = git_repository_refdb(&tx->db, repo)) < 0)
+		goto on_error;
+
+	tx->type = TRANSACTION_REFS;
+	memcpy(&tx->pool, &pool, sizeof(git_pool));
+	tx->repo = repo;
+	*out = tx;
+	return 0;
+
+on_error:
+	git_pool_clear(&pool);
+	return error;
+}
+
+int git_transaction_lock_ref(git_transaction *tx, const char *refname)
+{
+	int error;
+	transaction_node *node;
+
+	assert(tx && refname);
+
+	node = git_pool_mallocz(&tx->pool, sizeof(transaction_node));
+	GITERR_CHECK_ALLOC(node);
+
+	node->name = git_pool_strdup(&tx->pool, refname);
+	GITERR_CHECK_ALLOC(node->name);
+
+	if ((error = git_refdb_lock(&node->payload, tx->db, refname)) < 0)
+		return error;
+
+	git_strmap_insert(tx->locks, node->name, node, &error);
+	if (error < 0) 
+		goto cleanup;
+
+	return 0;
+
+cleanup:
+	git_refdb_unlock(tx->db, node->payload, false, false, NULL, NULL, NULL);
+
+	return error;
+}
+
+static int find_locked(transaction_node **out, git_transaction *tx, const char *refname)
+{
+	git_strmap_iter pos;
+	transaction_node *node;
+
+	pos = git_strmap_lookup_index(tx->locks, refname);
+	if (!git_strmap_valid_index(tx->locks, pos)) {
+		giterr_set(GITERR_REFERENCE, "the specified reference is not locked");
+		return GIT_ENOTFOUND;
+	}
+
+	node = git_strmap_value_at(tx->locks, pos);
+
+	*out = node;
+	return 0;
+}
+
+static int copy_common(transaction_node *node, git_transaction *tx, const git_signature *sig, const char *msg)
+{
+	if (sig && git_signature__pdup(&node->sig, sig, &tx->pool) < 0)
+		return -1;
+
+	if (!node->sig) {
+		git_signature *tmp;
+		int error;
+
+		if (git_reference__log_signature(&tmp, tx->repo) < 0)
+			return -1;
+
+		/* make sure the sig we use is in our pool */
+		error = git_signature__pdup(&node->sig, tmp, &tx->pool);
+		git_signature_free(tmp);
+		if (error < 0)
+			return error;
+	}
+
+	if (msg) {
+		node->message = git_pool_strdup(&tx->pool, msg);
+		GITERR_CHECK_ALLOC(node->message);
+	}
+
+	return 0;
+}
+
+int git_transaction_set_target(git_transaction *tx, const char *refname, const git_oid *target, const git_signature *sig, const char *msg)
+{
+	int error;
+	transaction_node *node;
+
+	assert(tx && refname && target);
+
+	if ((error = find_locked(&node, tx, refname)) < 0)
+		return error;
+
+	if ((error = copy_common(node, tx, sig, msg)) < 0)
+		return error;
+
+	git_oid_cpy(&node->target.id, target);
+	node->ref_type = GIT_REF_OID;
+
+	return 0;
+}
+
+int git_transaction_set_symbolic_target(git_transaction *tx, const char *refname, const char *target, const git_signature *sig, const char *msg)
+{
+	int error;
+	transaction_node *node;
+
+	assert(tx && refname && target);
+
+	if ((error = find_locked(&node, tx, refname)) < 0)
+		return error;
+
+	if ((error = copy_common(node, tx, sig, msg)) < 0)
+		return error;
+
+	node->target.symbolic = git_pool_strdup(&tx->pool, target);
+	GITERR_CHECK_ALLOC(node->target.symbolic);
+	node->ref_type = GIT_REF_SYMBOLIC;
+
+	return 0;
+}
+
+int git_transaction_remove(git_transaction *tx, const char *refname)
+{
+	int error;
+	transaction_node *node;
+
+	if ((error = find_locked(&node, tx, refname)) < 0)
+		return error;
+
+	node->remove = true;
+	node->ref_type = GIT_REF_OID; /* the id will be ignored */
+
+	return 0;
+}
+
+static int dup_reflog(git_reflog **out, const git_reflog *in, git_pool *pool)
+{
+	git_reflog *reflog;
+	git_reflog_entry *entries;
+	size_t len, i;
+
+	reflog = git_pool_mallocz(pool, sizeof(git_reflog));
+	GITERR_CHECK_ALLOC(reflog);
+
+	reflog->ref_name = git_pool_strdup(pool, in->ref_name);
+	GITERR_CHECK_ALLOC(reflog->ref_name);
+
+	len = in->entries.length;
+	reflog->entries.length = len;
+	reflog->entries.contents = git_pool_mallocz(pool, len * sizeof(void *));
+	GITERR_CHECK_ALLOC(reflog->entries.contents);
+
+	entries = git_pool_mallocz(pool, len * sizeof(git_reflog_entry));
+	GITERR_CHECK_ALLOC(entries);
+
+	for (i = 0; i < len; i++) {
+		const git_reflog_entry *src;
+		git_reflog_entry *tgt;
+
+		tgt = &entries[i];
+		reflog->entries.contents[i] = tgt;
+
+		src = git_vector_get(&in->entries, i);
+		git_oid_cpy(&tgt->oid_old, &src->oid_old);
+		git_oid_cpy(&tgt->oid_cur, &src->oid_cur);
+
+		tgt->msg = git_pool_strdup(pool, src->msg);
+		GITERR_CHECK_ALLOC(tgt->msg);
+
+		if (git_signature__pdup(&tgt->committer, src->committer, pool) < 0)
+			return -1;
+	}
+
+
+	*out = reflog;
+	return 0;
+}
+
+int git_transaction_set_reflog(git_transaction *tx, const char *refname, const git_reflog *reflog)
+{
+	int error;
+	transaction_node *node;
+
+	assert(tx && refname && reflog);
+
+	if ((error = find_locked(&node, tx, refname)) < 0)
+		return error;
+
+	if ((error = dup_reflog(&node->reflog, reflog, &tx->pool)) < 0)
+		return error;
+
+	return 0;
+}
+
+static int update_target(git_refdb *db, transaction_node *node)
+{
+	git_reference *ref;
+	int error, update_reflog;
+
+	if (node->ref_type == GIT_REF_OID) {
+		ref = git_reference__alloc(node->name, &node->target.id, NULL);
+	} else if (node->ref_type == GIT_REF_SYMBOLIC) {
+		ref = git_reference__alloc_symbolic(node->name, node->target.symbolic);
+	} else {
+		abort();
+	}
+
+	GITERR_CHECK_ALLOC(ref);
+	update_reflog = node->reflog == NULL;
+
+	if (node->remove) {
+		error =  git_refdb_unlock(db, node->payload, 2, false, ref, NULL, NULL);
+	} else if (node->ref_type == GIT_REF_OID) {
+		error = git_refdb_unlock(db, node->payload, true, update_reflog, ref, node->sig, node->message);
+	} else if (node->ref_type == GIT_REF_SYMBOLIC) {
+		error = git_refdb_unlock(db, node->payload, true, update_reflog, ref, node->sig, node->message);
+	} else {
+		abort();
+	}
+
+	git_reference_free(ref);
+	node->committed = true;
+
+	return error;
+}
+
+int git_transaction_commit(git_transaction *tx)
+{
+	transaction_node *node;
+	int error = 0;
+
+	assert(tx);
+
+	if (tx->type == TRANSACTION_CONFIG) {
+		error = git_config_unlock(tx->cfg, true);
+		tx->cfg = NULL;
+
+		return error;
+	}
+
+	git_strmap_foreach_value(tx->locks, node, {
+		if (node->reflog) {
+			if ((error = tx->db->backend->reflog_write(tx->db->backend, node->reflog)) < 0)
+				return error;
+		}
+
+		if (node->ref_type != GIT_REF_INVALID) {
+			if ((error = update_target(tx->db, node)) < 0)
+				return error;
+		}
+	});
+
+	return 0;
+}
+
+void git_transaction_free(git_transaction *tx)
+{
+	transaction_node *node;
+	git_pool pool;
+
+	assert(tx);
+
+	if (tx->type == TRANSACTION_CONFIG) {
+		if (tx->cfg) {
+			git_config_unlock(tx->cfg, false);
+			git_config_free(tx->cfg);
+		}
+
+		git__free(tx);
+		return;
+	}
+
+	/* start by unlocking the ones we've left hanging, if any */
+	git_strmap_foreach_value(tx->locks, node, {
+		if (node->committed)
+			continue;
+
+		git_refdb_unlock(tx->db, node->payload, false, false, NULL, NULL, NULL);
+	});
+
+	git_refdb_free(tx->db);
+	git_strmap_free(tx->locks);
+
+	/* tx is inside the pool, so we need to extract the data */
+	memcpy(&pool, &tx->pool, sizeof(git_pool));
+	git_pool_clear(&pool);
+}

vendor/libgit2-sys/libgit2/src/transaction.h

diff --git a/vendor/libgit2-sys/libgit2/src/transaction.h b/vendor/libgit2-sys/libgit2/src/transaction.h
new file mode 100644
index 0000000..780c068
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transaction.h
@@ -0,0 +1,14 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_transaction_h__
+#define INCLUDE_transaction_h__
+
+#include "common.h"
+
+int git_transaction_config_new(git_transaction **out, git_config *cfg);
+
+#endif

vendor/libgit2-sys/libgit2/src/transport.c

diff --git a/vendor/libgit2-sys/libgit2/src/transport.c b/vendor/libgit2-sys/libgit2/src/transport.c
new file mode 100644
index 0000000..f1e18b3
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transport.c
@@ -0,0 +1,222 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "git2/types.h"
+#include "git2/remote.h"
+#include "git2/net.h"
+#include "git2/transport.h"
+#include "git2/sys/transport.h"
+#include "path.h"
+
+typedef struct transport_definition {
+	char *prefix;
+	git_transport_cb fn;
+	void *param;
+} transport_definition;
+
+static git_smart_subtransport_definition http_subtransport_definition = { git_smart_subtransport_http, 1, NULL };
+static git_smart_subtransport_definition git_subtransport_definition = { git_smart_subtransport_git, 0, NULL };
+#ifdef GIT_SSH
+static git_smart_subtransport_definition ssh_subtransport_definition = { git_smart_subtransport_ssh, 0, NULL };
+#endif
+
+static transport_definition local_transport_definition = { "file://", git_transport_local, NULL };
+
+static transport_definition transports[] = {
+	{ "git://",   git_transport_smart, &git_subtransport_definition },
+	{ "http://",  git_transport_smart, &http_subtransport_definition },
+	{ "https://", git_transport_smart, &http_subtransport_definition },
+	{ "file://",  git_transport_local, NULL },
+#ifdef GIT_SSH
+	{ "ssh://",   git_transport_smart, &ssh_subtransport_definition },
+	{ "ssh+git://",   git_transport_smart, &ssh_subtransport_definition },
+	{ "git+ssh://",   git_transport_smart, &ssh_subtransport_definition },
+#endif
+	{ NULL, 0, 0 }
+};
+
+static git_vector custom_transports = GIT_VECTOR_INIT;
+
+#define GIT_TRANSPORT_COUNT (sizeof(transports)/sizeof(transports[0])) - 1
+
+static transport_definition * transport_find_by_url(const char *url)
+{
+	size_t i = 0;
+	transport_definition *d;
+
+	/* Find a user transport who wants to deal with this URI */
+	git_vector_foreach(&custom_transports, i, d) {
+		if (strncasecmp(url, d->prefix, strlen(d->prefix)) == 0) {
+			return d;
+		}
+	}
+
+	/* Find a system transport for this URI */
+	for (i = 0; i < GIT_TRANSPORT_COUNT; ++i) {
+		d = &transports[i];
+
+		if (strncasecmp(url, d->prefix, strlen(d->prefix)) == 0) {
+			return d;
+		}
+	}
+
+	return NULL;
+}
+
+static int transport_find_fn(
+	git_transport_cb *out,
+	const char *url,
+	void **param)
+{
+	transport_definition *definition = transport_find_by_url(url);
+
+#ifdef GIT_WIN32
+	/* On Windows, it might not be possible to discern between absolute local
+	 * and ssh paths - first check if this is a valid local path that points
+	 * to a directory and if so assume local path, else assume SSH */
+
+	/* Check to see if the path points to a file on the local file system */
+	if (!definition && git_path_exists(url) && git_path_isdir(url))
+		definition = &local_transport_definition;
+#endif
+
+	/* For other systems, perform the SSH check first, to avoid going to the
+	 * filesystem if it is not necessary */
+
+	/* It could be a SSH remote path. Check to see if there's a : */
+	if (!definition && strrchr(url, ':')) {
+		/* re-search transports again with ssh:// as url
+		 * so that we can find a third party ssh transport */
+		definition = transport_find_by_url("ssh://");
+	}
+
+#ifndef GIT_WIN32
+	/* Check to see if the path points to a file on the local file system */
+	if (!definition && git_path_exists(url) && git_path_isdir(url))
+		definition = &local_transport_definition;
+#endif
+
+	if (!definition)
+		return GIT_ENOTFOUND;
+
+	*out = definition->fn;
+	*param = definition->param;
+
+	return 0;
+}
+
+/**************
+ * Public API *
+ **************/
+
+int git_transport_new(git_transport **out, git_remote *owner, const char *url)
+{
+	git_transport_cb fn;
+	git_transport *transport;
+	void *param;
+	int error;
+
+	if ((error = transport_find_fn(&fn, url, &param)) == GIT_ENOTFOUND) {
+		giterr_set(GITERR_NET, "unsupported URL protocol");
+		return -1;
+	} else if (error < 0)
+		return error;
+
+	if ((error = fn(&transport, owner, param)) < 0)
+		return error;
+
+	GITERR_CHECK_VERSION(transport, GIT_TRANSPORT_VERSION, "git_transport");
+
+	*out = transport;
+
+	return 0;
+}
+
+int git_transport_register(
+	const char *scheme,
+	git_transport_cb cb,
+	void *param)
+{
+	git_buf prefix = GIT_BUF_INIT;
+	transport_definition *d, *definition = NULL;
+	size_t i;
+	int error = 0;
+
+	assert(scheme);
+	assert(cb);
+
+	if ((error = git_buf_printf(&prefix, "%s://", scheme)) < 0)
+		goto on_error;
+
+	git_vector_foreach(&custom_transports, i, d) {
+		if (strcasecmp(d->prefix, prefix.ptr) == 0) {
+			error = GIT_EEXISTS;
+			goto on_error;
+		}
+	}
+
+	definition = git__calloc(1, sizeof(transport_definition));
+	GITERR_CHECK_ALLOC(definition);
+
+	definition->prefix = git_buf_detach(&prefix);
+	definition->fn = cb;
+	definition->param = param;
+
+	if (git_vector_insert(&custom_transports, definition) < 0)
+		goto on_error;
+
+	return 0;
+
+on_error:
+	git_buf_free(&prefix);
+	git__free(definition);
+	return error;
+}
+
+int git_transport_unregister(const char *scheme)
+{
+	git_buf prefix = GIT_BUF_INIT;
+	transport_definition *d;
+	size_t i;
+	int error = 0;
+
+	assert(scheme);
+
+	if ((error = git_buf_printf(&prefix, "%s://", scheme)) < 0)
+		goto done;
+
+	git_vector_foreach(&custom_transports, i, d) {
+		if (strcasecmp(d->prefix, prefix.ptr) == 0) {
+			if ((error = git_vector_remove(&custom_transports, i)) < 0)
+				goto done;
+
+			git__free(d->prefix);
+			git__free(d);
+
+			if (!custom_transports.length)
+				git_vector_free(&custom_transports);
+
+			error = 0;
+			goto done;
+		}
+	}
+
+	error = GIT_ENOTFOUND;
+
+done:
+	git_buf_free(&prefix);
+	return error;
+}
+
+int git_transport_init(git_transport *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_transport, GIT_TRANSPORT_INIT);
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/transports/auth.c

diff --git a/vendor/libgit2-sys/libgit2/src/transports/auth.c b/vendor/libgit2-sys/libgit2/src/transports/auth.c
new file mode 100644
index 0000000..9597cc2
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transports/auth.c
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "auth.h"
+
+#include "git2.h"
+#include "buffer.h"
+
+static int basic_next_token(
+	git_buf *out, git_http_auth_context *ctx, git_cred *c)
+{
+	git_cred_userpass_plaintext *cred;
+	git_buf raw = GIT_BUF_INIT;
+	int error = -1;
+
+	GIT_UNUSED(ctx);
+
+	if (c->credtype != GIT_CREDTYPE_USERPASS_PLAINTEXT) {
+		giterr_set(GITERR_INVALID, "invalid credential type for basic auth");
+		goto on_error;
+	}
+
+	cred = (git_cred_userpass_plaintext *)c;
+
+	git_buf_printf(&raw, "%s:%s", cred->username, cred->password);
+
+	if (git_buf_oom(&raw) ||
+		git_buf_puts(out, "Authorization: Basic ") < 0 ||
+		git_buf_encode_base64(out, git_buf_cstr(&raw), raw.size) < 0 ||
+		git_buf_puts(out, "\r\n") < 0)
+		goto on_error;
+
+	error = 0;
+
+on_error:
+	if (raw.size)
+		git__memzero(raw.ptr, raw.size);
+
+	git_buf_free(&raw);
+	return error;
+}
+
+static git_http_auth_context basic_context = {
+	GIT_AUTHTYPE_BASIC,
+	GIT_CREDTYPE_USERPASS_PLAINTEXT,
+	NULL,
+	basic_next_token,
+	NULL
+};
+
+int git_http_auth_basic(
+	git_http_auth_context **out, const gitno_connection_data *connection_data)
+{
+	GIT_UNUSED(connection_data);
+
+	*out = &basic_context;
+	return 0;
+}
+
+int git_http_auth_dummy(
+	git_http_auth_context **out, const gitno_connection_data *connection_data)
+{
+	GIT_UNUSED(connection_data);
+
+	*out = NULL;
+	return 0;
+}
+

vendor/libgit2-sys/libgit2/src/transports/auth.h

diff --git a/vendor/libgit2-sys/libgit2/src/transports/auth.h b/vendor/libgit2-sys/libgit2/src/transports/auth.h
new file mode 100644
index 0000000..3b8b29e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transports/auth.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_transports_auth_h__
+#define INCLUDE_transports_auth_h__
+
+#include "common.h"
+
+#include "git2.h"
+#include "netops.h"
+
+typedef enum {
+	GIT_AUTHTYPE_BASIC = 1,
+	GIT_AUTHTYPE_NEGOTIATE = 2,
+} git_http_authtype_t;
+
+typedef struct git_http_auth_context git_http_auth_context;
+
+struct git_http_auth_context {
+	/** Type of scheme */
+	git_http_authtype_t type;
+
+	/** Supported credentials */
+	git_credtype_t credtypes;
+
+	/** Sets the challenge on the authentication context */
+	int (*set_challenge)(git_http_auth_context *ctx, const char *challenge);
+
+	/** Gets the next authentication token from the context */
+	int (*next_token)(git_buf *out, git_http_auth_context *ctx, git_cred *cred);
+
+	/** Frees the authentication context */
+	void (*free)(git_http_auth_context *ctx);
+};
+
+typedef struct {
+	/** Type of scheme */
+	git_http_authtype_t type;
+
+	/** Name of the scheme (as used in the Authorization header) */
+	const char *name;
+
+	/** Credential types this scheme supports */
+	git_credtype_t credtypes;
+
+	/** Function to initialize an authentication context */
+	int (*init_context)(
+		git_http_auth_context **out,
+		const gitno_connection_data *connection_data);
+} git_http_auth_scheme;
+
+int git_http_auth_dummy(
+	git_http_auth_context **out,
+	const gitno_connection_data *connection_data);
+
+int git_http_auth_basic(
+	git_http_auth_context **out,
+	const gitno_connection_data *connection_data);
+
+#endif

vendor/libgit2-sys/libgit2/src/transports/auth_negotiate.c

diff --git a/vendor/libgit2-sys/libgit2/src/transports/auth_negotiate.c b/vendor/libgit2-sys/libgit2/src/transports/auth_negotiate.c
new file mode 100644
index 0000000..c9bc304
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transports/auth_negotiate.c
@@ -0,0 +1,276 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "auth_negotiate.h"
+
+#ifdef GIT_GSSAPI
+
+#include "git2.h"
+#include "buffer.h"
+#include "auth.h"
+
+#include <gssapi.h>
+#include <krb5.h>
+
+static gss_OID_desc negotiate_oid_spnego =
+	{ 6, (void *) "\x2b\x06\x01\x05\x05\x02" };
+static gss_OID_desc negotiate_oid_krb5 =
+	{ 9, (void *) "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02" };
+
+static gss_OID negotiate_oids[] =
+	{ &negotiate_oid_spnego, &negotiate_oid_krb5, NULL };
+
+typedef struct {
+	git_http_auth_context parent;
+	unsigned configured : 1,
+		complete : 1;
+	git_buf target;
+	char *challenge;
+	gss_ctx_id_t gss_context;
+	gss_OID oid;
+} http_auth_negotiate_context;
+
+static void negotiate_err_set(
+	OM_uint32 status_major,
+	OM_uint32 status_minor,
+	const char *message)
+{
+	gss_buffer_desc buffer = GSS_C_EMPTY_BUFFER;
+	OM_uint32 status_display, context = 0;
+
+	if (gss_display_status(&status_display, status_major, GSS_C_GSS_CODE,
+		GSS_C_NO_OID, &context, &buffer) == GSS_S_COMPLETE) {
+		giterr_set(GITERR_NET, "%s: %.*s (%d.%d)",
+			message, (int)buffer.length, (const char *)buffer.value,
+			status_major, status_minor);
+		gss_release_buffer(&status_minor, &buffer);
+	} else {
+		giterr_set(GITERR_NET, "%s: unknown negotiate error (%d.%d)",
+			message, status_major, status_minor);
+	}
+}
+
+static int negotiate_set_challenge(
+	git_http_auth_context *c,
+	const char *challenge)
+{
+	http_auth_negotiate_context *ctx = (http_auth_negotiate_context *)c;
+
+	assert(ctx && ctx->configured && challenge);
+
+	git__free(ctx->challenge);
+
+	ctx->challenge = git__strdup(challenge);
+	GITERR_CHECK_ALLOC(ctx->challenge);
+
+	return 0;
+}
+
+static int negotiate_next_token(
+	git_buf *buf,
+	git_http_auth_context *c,
+	git_cred *cred)
+{
+	http_auth_negotiate_context *ctx = (http_auth_negotiate_context *)c;
+	OM_uint32 status_major, status_minor;
+	gss_buffer_desc target_buffer = GSS_C_EMPTY_BUFFER,
+		input_token = GSS_C_EMPTY_BUFFER,
+		output_token = GSS_C_EMPTY_BUFFER;
+	gss_buffer_t input_token_ptr = GSS_C_NO_BUFFER;
+	git_buf input_buf = GIT_BUF_INIT;
+	gss_name_t server = NULL;
+	gss_OID mech;
+	size_t challenge_len;
+	int error = 0;
+
+	assert(buf && ctx && ctx->configured && cred && cred->credtype == GIT_CREDTYPE_DEFAULT);
+
+	if (ctx->complete)
+		return 0;
+
+	target_buffer.value = (void *)ctx->target.ptr;
+	target_buffer.length = ctx->target.size;
+
+	status_major = gss_import_name(&status_minor, &target_buffer,
+		GSS_C_NT_HOSTBASED_SERVICE, &server);
+
+	if (GSS_ERROR(status_major)) {
+		negotiate_err_set(status_major, status_minor,
+			"Could not parse principal");
+		error = -1;
+		goto done;
+	}
+
+	challenge_len = ctx->challenge ? strlen(ctx->challenge) : 0;
+
+	if (challenge_len < 9) {
+		giterr_set(GITERR_NET, "no negotiate challenge sent from server");
+		error = -1;
+		goto done;
+	} else if (challenge_len > 9) {
+		if (git_buf_decode_base64(&input_buf,
+				ctx->challenge + 10, challenge_len - 10) < 0) {
+			giterr_set(GITERR_NET, "invalid negotiate challenge from server");
+			error = -1;
+			goto done;
+		}
+
+		input_token.value = input_buf.ptr;
+		input_token.length = input_buf.size;
+		input_token_ptr = &input_token;
+	} else if (ctx->gss_context != GSS_C_NO_CONTEXT) {
+		giterr_set(GITERR_NET, "could not restart authentication");
+		error = -1;
+		goto done;
+	}
+
+	mech = &negotiate_oid_spnego;
+
+	if (GSS_ERROR(status_major = gss_init_sec_context(
+		&status_minor,
+		GSS_C_NO_CREDENTIAL,
+		&ctx->gss_context,
+		server,
+		mech,
+		GSS_C_DELEG_FLAG | GSS_C_MUTUAL_FLAG,
+		GSS_C_INDEFINITE,
+		GSS_C_NO_CHANNEL_BINDINGS,
+		input_token_ptr,
+		NULL,
+		&output_token,
+		NULL,
+		NULL))) {
+		negotiate_err_set(status_major, status_minor, "Negotiate failure");
+		error = -1;
+		goto done;
+	}
+
+	/* This message merely told us auth was complete; we do not respond. */
+	if (status_major == GSS_S_COMPLETE) {
+		ctx->complete = 1;
+		goto done;
+	}
+
+	git_buf_puts(buf, "Authorization: Negotiate ");
+	git_buf_encode_base64(buf, output_token.value, output_token.length);
+	git_buf_puts(buf, "\r\n");
+
+	if (git_buf_oom(buf))
+		error = -1;
+
+done:
+	gss_release_name(&status_minor, &server);
+	gss_release_buffer(&status_minor, (gss_buffer_t) &output_token);
+	git_buf_free(&input_buf);
+	return error;
+}
+
+static void negotiate_context_free(git_http_auth_context *c)
+{
+	http_auth_negotiate_context *ctx = (http_auth_negotiate_context *)c;
+	OM_uint32 status_minor;
+
+	if (ctx->gss_context != GSS_C_NO_CONTEXT) {
+		gss_delete_sec_context(
+			&status_minor, &ctx->gss_context, GSS_C_NO_BUFFER);
+		ctx->gss_context = GSS_C_NO_CONTEXT;
+	}
+
+	git_buf_free(&ctx->target);
+
+	git__free(ctx->challenge);
+
+	ctx->configured = 0;
+	ctx->complete = 0;
+	ctx->oid = NULL;
+
+	git__free(ctx);
+}
+
+static int negotiate_init_context(
+	http_auth_negotiate_context *ctx,
+	const gitno_connection_data *connection_data)
+{
+	OM_uint32 status_major, status_minor;
+	gss_OID item, *oid;
+	gss_OID_set mechanism_list;
+	size_t i;
+
+	/* Query supported mechanisms looking for SPNEGO) */
+	if (GSS_ERROR(status_major =
+		gss_indicate_mechs(&status_minor, &mechanism_list))) {
+		negotiate_err_set(status_major, status_minor,
+			"could not query mechanisms");
+		return -1;
+	}
+
+	if (mechanism_list) {
+		for (oid = negotiate_oids; *oid; oid++) {
+			for (i = 0; i < mechanism_list->count; i++) {
+				item = &mechanism_list->elements[i];
+
+				if (item->length == (*oid)->length &&
+					memcmp(item->elements, (*oid)->elements, item->length) == 0) {
+					ctx->oid = *oid;
+					break;
+				}
+
+			}
+
+			if (ctx->oid)
+				break;
+		}
+	}
+
+	gss_release_oid_set(&status_minor, &mechanism_list);
+
+	if (!ctx->oid) {
+		giterr_set(GITERR_NET, "negotiate authentication is not supported");
+		return -1;
+	}
+
+	git_buf_puts(&ctx->target, "HTTP@");
+	git_buf_puts(&ctx->target, connection_data->host);
+
+	if (git_buf_oom(&ctx->target))
+		return -1;
+
+	ctx->gss_context = GSS_C_NO_CONTEXT;
+	ctx->configured = 1;
+
+	return 0;
+}
+
+int git_http_auth_negotiate(
+	git_http_auth_context **out,
+	const gitno_connection_data *connection_data)
+{
+	http_auth_negotiate_context *ctx;
+
+	*out = NULL;
+
+	ctx = git__calloc(1, sizeof(http_auth_negotiate_context));
+	GITERR_CHECK_ALLOC(ctx);
+
+	if (negotiate_init_context(ctx, connection_data) < 0) {
+		git__free(ctx);
+		return -1;
+	}
+
+	ctx->parent.type = GIT_AUTHTYPE_NEGOTIATE;
+	ctx->parent.credtypes = GIT_CREDTYPE_DEFAULT;
+	ctx->parent.set_challenge = negotiate_set_challenge;
+	ctx->parent.next_token = negotiate_next_token;
+	ctx->parent.free = negotiate_context_free;
+
+	*out = (git_http_auth_context *)ctx;
+
+	return 0;
+}
+
+#endif /* GIT_GSSAPI */
+

vendor/libgit2-sys/libgit2/src/transports/auth_negotiate.h

diff --git a/vendor/libgit2-sys/libgit2/src/transports/auth_negotiate.h b/vendor/libgit2-sys/libgit2/src/transports/auth_negotiate.h
new file mode 100644
index 0000000..15a528a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transports/auth_negotiate.h
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_transports_auth_negotiate_h__
+#define INCLUDE_transports_auth_negotiate_h__
+
+#include "common.h"
+#include "git2.h"
+#include "auth.h"
+
+#ifdef GIT_GSSAPI
+
+extern int git_http_auth_negotiate(
+	git_http_auth_context **out,
+	const gitno_connection_data *connection_data);
+
+#else
+
+#define git_http_auth_negotiate git_http_auth_dummy
+
+#endif /* GIT_GSSAPI */
+
+#endif

vendor/libgit2-sys/libgit2/src/transports/cred.c

diff --git a/vendor/libgit2-sys/libgit2/src/transports/cred.c b/vendor/libgit2-sys/libgit2/src/transports/cred.c
new file mode 100644
index 0000000..8055e2d
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transports/cred.c
@@ -0,0 +1,390 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "cred.h"
+
+#include "git2.h"
+#include "smart.h"
+#include "git2/cred_helpers.h"
+
+static int git_cred_ssh_key_type_new(
+	git_cred **cred,
+	const char *username,
+	const char *publickey,
+	const char *privatekey,
+	const char *passphrase,
+	git_credtype_t credtype);
+
+int git_cred_has_username(git_cred *cred)
+{
+	if (cred->credtype == GIT_CREDTYPE_DEFAULT)
+		return 0;
+
+	return 1;
+}
+
+const char *git_cred__username(git_cred *cred)
+{
+	switch (cred->credtype) {
+	case GIT_CREDTYPE_USERNAME:
+	{
+		git_cred_username *c = (git_cred_username *) cred;
+		return c->username;
+	}
+	case GIT_CREDTYPE_USERPASS_PLAINTEXT:
+	{
+		git_cred_userpass_plaintext *c = (git_cred_userpass_plaintext *) cred;
+		return c->username;
+	}
+	case GIT_CREDTYPE_SSH_KEY:
+	case GIT_CREDTYPE_SSH_MEMORY:
+	{
+		git_cred_ssh_key *c = (git_cred_ssh_key *) cred;
+		return c->username;
+	}
+	case GIT_CREDTYPE_SSH_CUSTOM:
+	{
+		git_cred_ssh_custom *c = (git_cred_ssh_custom *) cred;
+		return c->username;
+	}
+	case GIT_CREDTYPE_SSH_INTERACTIVE:
+	{
+		git_cred_ssh_interactive *c = (git_cred_ssh_interactive *) cred;
+		return c->username;
+	}
+
+	default:
+		return NULL;
+	}
+}
+
+static void plaintext_free(struct git_cred *cred)
+{
+	git_cred_userpass_plaintext *c = (git_cred_userpass_plaintext *)cred;
+
+	git__free(c->username);
+
+	/* Zero the memory which previously held the password */
+	if (c->password) {
+		size_t pass_len = strlen(c->password);
+		git__memzero(c->password, pass_len);
+		git__free(c->password);
+	}
+
+	git__free(c);
+}
+
+int git_cred_userpass_plaintext_new(
+	git_cred **cred,
+	const char *username,
+	const char *password)
+{
+	git_cred_userpass_plaintext *c;
+
+	assert(cred && username && password);
+
+	c = git__malloc(sizeof(git_cred_userpass_plaintext));
+	GITERR_CHECK_ALLOC(c);
+
+	c->parent.credtype = GIT_CREDTYPE_USERPASS_PLAINTEXT;
+	c->parent.free = plaintext_free;
+	c->username = git__strdup(username);
+
+	if (!c->username) {
+		git__free(c);
+		return -1;
+	}
+
+	c->password = git__strdup(password);
+
+	if (!c->password) {
+		git__free(c->username);
+		git__free(c);
+		return -1;
+	}
+
+	*cred = &c->parent;
+	return 0;
+}
+
+static void ssh_key_free(struct git_cred *cred)
+{
+	git_cred_ssh_key *c =
+		(git_cred_ssh_key *)cred;
+
+	git__free(c->username);
+
+	if (c->privatekey) {
+		/* Zero the memory which previously held the private key */
+		size_t key_len = strlen(c->privatekey);
+		git__memzero(c->privatekey, key_len);
+		git__free(c->privatekey);
+	}
+
+	if (c->passphrase) {
+		/* Zero the memory which previously held the passphrase */
+		size_t pass_len = strlen(c->passphrase);
+		git__memzero(c->passphrase, pass_len);
+		git__free(c->passphrase);
+	}
+
+	if (c->publickey) {
+		/* Zero the memory which previously held the public key */
+		size_t key_len = strlen(c->publickey);
+		git__memzero(c->publickey, key_len);
+		git__free(c->publickey);
+	}
+
+	git__free(c);
+}
+
+static void ssh_interactive_free(struct git_cred *cred)
+{
+	git_cred_ssh_interactive *c = (git_cred_ssh_interactive *)cred;
+
+	git__free(c->username);
+
+	git__free(c);
+}
+
+static void ssh_custom_free(struct git_cred *cred)
+{
+	git_cred_ssh_custom *c = (git_cred_ssh_custom *)cred;
+
+	git__free(c->username);
+
+	if (c->publickey) {
+		/* Zero the memory which previously held the publickey */
+		size_t key_len = strlen(c->publickey);
+		git__memzero(c->publickey, key_len);
+		git__free(c->publickey);
+	}
+
+	git__free(c);
+}
+
+static void default_free(struct git_cred *cred)
+{
+	git_cred_default *c = (git_cred_default *)cred;
+
+	git__free(c);
+}
+
+static void username_free(struct git_cred *cred)
+{
+	git__free(cred);
+}
+
+int git_cred_ssh_key_new(
+	git_cred **cred,
+	const char *username,
+	const char *publickey,
+	const char *privatekey,
+	const char *passphrase)
+{
+	return git_cred_ssh_key_type_new(
+		cred,
+		username,
+		publickey,
+		privatekey,
+		passphrase,
+		GIT_CREDTYPE_SSH_KEY);
+}
+
+int git_cred_ssh_key_memory_new(
+	git_cred **cred,
+	const char *username,
+	const char *publickey,
+	const char *privatekey,
+	const char *passphrase)
+{
+#ifdef GIT_SSH_MEMORY_CREDENTIALS
+	return git_cred_ssh_key_type_new(
+		cred,
+		username,
+		publickey,
+		privatekey,
+		passphrase,
+		GIT_CREDTYPE_SSH_MEMORY);
+#else
+	GIT_UNUSED(cred);
+	GIT_UNUSED(username);
+	GIT_UNUSED(publickey);
+	GIT_UNUSED(privatekey);
+	GIT_UNUSED(passphrase);
+
+	giterr_set(GITERR_INVALID,
+		"this version of libgit2 was not built with ssh memory credentials.");
+	return -1;
+#endif
+}
+
+static int git_cred_ssh_key_type_new(
+	git_cred **cred,
+	const char *username,
+	const char *publickey,
+	const char *privatekey,
+	const char *passphrase,
+	git_credtype_t credtype)
+{
+	git_cred_ssh_key *c;
+
+	assert(username && cred && privatekey);
+
+	c = git__calloc(1, sizeof(git_cred_ssh_key));
+	GITERR_CHECK_ALLOC(c);
+
+	c->parent.credtype = credtype;
+	c->parent.free = ssh_key_free;
+
+	c->username = git__strdup(username);
+	GITERR_CHECK_ALLOC(c->username);
+
+	c->privatekey = git__strdup(privatekey);
+	GITERR_CHECK_ALLOC(c->privatekey);
+
+	if (publickey) {
+		c->publickey = git__strdup(publickey);
+		GITERR_CHECK_ALLOC(c->publickey);
+	}
+
+	if (passphrase) {
+		c->passphrase = git__strdup(passphrase);
+		GITERR_CHECK_ALLOC(c->passphrase);
+	}
+
+	*cred = &c->parent;
+	return 0;
+}
+
+int git_cred_ssh_interactive_new(
+	git_cred **out,
+	const char *username,
+	git_cred_ssh_interactive_callback prompt_callback,
+	void *payload)
+{
+	git_cred_ssh_interactive *c;
+
+	assert(out && username && prompt_callback);
+
+	c = git__calloc(1, sizeof(git_cred_ssh_interactive));
+	GITERR_CHECK_ALLOC(c);
+
+	c->parent.credtype = GIT_CREDTYPE_SSH_INTERACTIVE;
+	c->parent.free = ssh_interactive_free;
+
+	c->username = git__strdup(username);
+	GITERR_CHECK_ALLOC(c->username);
+
+	c->prompt_callback = prompt_callback;
+	c->payload = payload;
+
+	*out = &c->parent;
+	return 0;
+}
+
+int git_cred_ssh_key_from_agent(git_cred **cred, const char *username) {
+	git_cred_ssh_key *c;
+
+	assert(username && cred);
+
+	c = git__calloc(1, sizeof(git_cred_ssh_key));
+	GITERR_CHECK_ALLOC(c);
+
+	c->parent.credtype = GIT_CREDTYPE_SSH_KEY;
+	c->parent.free = ssh_key_free;
+
+	c->username = git__strdup(username);
+	GITERR_CHECK_ALLOC(c->username);
+
+	c->privatekey = NULL;
+
+	*cred = &c->parent;
+	return 0;
+}
+
+int git_cred_ssh_custom_new(
+	git_cred **cred,
+	const char *username,
+	const char *publickey,
+	size_t publickey_len,
+	git_cred_sign_callback sign_callback,
+	void *payload)
+{
+	git_cred_ssh_custom *c;
+
+	assert(username && cred);
+
+	c = git__calloc(1, sizeof(git_cred_ssh_custom));
+	GITERR_CHECK_ALLOC(c);
+
+	c->parent.credtype = GIT_CREDTYPE_SSH_CUSTOM;
+	c->parent.free = ssh_custom_free;
+
+	c->username = git__strdup(username);
+	GITERR_CHECK_ALLOC(c->username);
+
+	if (publickey_len > 0) {
+		c->publickey = git__malloc(publickey_len);
+		GITERR_CHECK_ALLOC(c->publickey);
+
+		memcpy(c->publickey, publickey, publickey_len);
+	}
+
+	c->publickey_len = publickey_len;
+	c->sign_callback = sign_callback;
+	c->payload = payload;
+
+	*cred = &c->parent;
+	return 0;
+}
+
+int git_cred_default_new(git_cred **cred)
+{
+	git_cred_default *c;
+
+	assert(cred);
+
+	c = git__calloc(1, sizeof(git_cred_default));
+	GITERR_CHECK_ALLOC(c);
+
+	c->credtype = GIT_CREDTYPE_DEFAULT;
+	c->free = default_free;
+
+	*cred = c;
+	return 0;
+}
+
+int git_cred_username_new(git_cred **cred, const char *username)
+{
+	git_cred_username *c;
+	size_t len, allocsize;
+
+	assert(cred);
+
+	len = strlen(username);
+
+	GITERR_CHECK_ALLOC_ADD(&allocsize, sizeof(git_cred_username), len);
+	GITERR_CHECK_ALLOC_ADD(&allocsize, allocsize, 1);
+	c = git__malloc(allocsize);
+	GITERR_CHECK_ALLOC(c);
+
+	c->parent.credtype = GIT_CREDTYPE_USERNAME;
+	c->parent.free = username_free;
+	memcpy(c->username, username, len + 1);
+
+	*cred = (git_cred *) c;
+	return 0;
+}
+
+void git_cred_free(git_cred *cred)
+{
+	if (!cred)
+		return;
+
+	cred->free(cred);
+}

vendor/libgit2-sys/libgit2/src/transports/cred.h

diff --git a/vendor/libgit2-sys/libgit2/src/transports/cred.h b/vendor/libgit2-sys/libgit2/src/transports/cred.h
new file mode 100644
index 0000000..ed5821c
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transports/cred.h
@@ -0,0 +1,16 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_transports_cred_h__
+#define INCLUDE_transports_cred_h__
+
+#include "common.h"
+
+#include "git2/transport.h"
+
+const char *git_cred__username(git_cred *cred);
+
+#endif

vendor/libgit2-sys/libgit2/src/transports/cred_helpers.c

diff --git a/vendor/libgit2-sys/libgit2/src/transports/cred_helpers.c b/vendor/libgit2-sys/libgit2/src/transports/cred_helpers.c
new file mode 100644
index 0000000..fdc56b1
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transports/cred_helpers.c
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "git2/cred_helpers.h"
+
+int git_cred_userpass(
+		git_cred **cred,
+		const char *url,
+		const char *user_from_url,
+		unsigned int allowed_types,
+		void *payload)
+{
+	git_cred_userpass_payload *userpass = (git_cred_userpass_payload*)payload;
+	const char *effective_username = NULL;
+
+	GIT_UNUSED(url);
+
+	if (!userpass || !userpass->password) return -1;
+
+	/* Username resolution: a username can be passed with the URL, the
+	 * credentials payload, or both. Here's what we do.  Note that if we get
+	 * this far, we know that any password the url may contain has already
+	 * failed at least once, so we ignore it.
+	 *
+	 * |  Payload    |   URL    |   Used    |
+	 * +-------------+----------+-----------+
+	 * |    yes      |   no     |  payload  |
+	 * |    yes      |   yes    |  payload  |
+	 * |    no       |   yes    |  url      |
+	 * |    no       |   no     |  FAIL     |
+	 */
+	if (userpass->username)
+		effective_username = userpass->username;
+	else if (user_from_url)
+		effective_username = user_from_url;
+	else
+		return -1;
+
+	if (GIT_CREDTYPE_USERNAME & allowed_types)
+		return git_cred_username_new(cred, effective_username);
+
+	if ((GIT_CREDTYPE_USERPASS_PLAINTEXT & allowed_types) == 0 ||
+			git_cred_userpass_plaintext_new(cred, effective_username, userpass->password) < 0)
+		return -1;
+
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/transports/git.c

diff --git a/vendor/libgit2-sys/libgit2/src/transports/git.c b/vendor/libgit2-sys/libgit2/src/transports/git.c
new file mode 100644
index 0000000..94178f2
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transports/git.c
@@ -0,0 +1,370 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "git2.h"
+#include "buffer.h"
+#include "netops.h"
+#include "git2/sys/transport.h"
+#include "stream.h"
+#include "streams/socket.h"
+
+#define OWNING_SUBTRANSPORT(s) ((git_subtransport *)(s)->parent.subtransport)
+
+static const char prefix_git[] = "git://";
+static const char cmd_uploadpack[] = "git-upload-pack";
+static const char cmd_receivepack[] = "git-receive-pack";
+
+typedef struct {
+	git_smart_subtransport_stream parent;
+	git_stream *io;
+	const char *cmd;
+	char *url;
+	unsigned sent_command : 1;
+} git_proto_stream;
+
+typedef struct {
+	git_smart_subtransport parent;
+	git_transport *owner;
+	git_proto_stream *current_stream;
+} git_subtransport;
+
+/*
+ * Create a git protocol request.
+ *
+ * For example: 0035git-upload-pack /libgit2/libgit2\0host=github.com\0
+ */
+static int gen_proto(git_buf *request, const char *cmd, const char *url)
+{
+	char *delim, *repo;
+	char host[] = "host=";
+	size_t len;
+
+	delim = strchr(url, '/');
+	if (delim == NULL) {
+		giterr_set(GITERR_NET, "malformed URL");
+		return -1;
+	}
+
+	repo = delim;
+	if (repo[1] == '~')
+		++repo;
+
+	delim = strchr(url, ':');
+	if (delim == NULL)
+		delim = strchr(url, '/');
+
+	len = 4 + strlen(cmd) + 1 + strlen(repo) + 1 + strlen(host) + (delim - url) + 1;
+
+	git_buf_grow(request, len);
+	git_buf_printf(request, "%04x%s %s%c%s",
+		(unsigned int)(len & 0x0FFFF), cmd, repo, 0, host);
+	git_buf_put(request, url, delim - url);
+	git_buf_putc(request, '\0');
+
+	if (git_buf_oom(request))
+		return -1;
+
+	return 0;
+}
+
+static int send_command(git_proto_stream *s)
+{
+	int error;
+	git_buf request = GIT_BUF_INIT;
+
+	error = gen_proto(&request, s->cmd, s->url);
+	if (error < 0)
+		goto cleanup;
+
+	error = git_stream_write(s->io, request.ptr, request.size, 0);
+	if (error >= 0)
+		s->sent_command = 1;
+
+cleanup:
+	git_buf_free(&request);
+	return error;
+}
+
+static int git_proto_stream_read(
+	git_smart_subtransport_stream *stream,
+	char *buffer,
+	size_t buf_size,
+	size_t *bytes_read)
+{
+	int error;
+	git_proto_stream *s = (git_proto_stream *)stream;
+	gitno_buffer buf;
+
+	*bytes_read = 0;
+
+	if (!s->sent_command && (error = send_command(s)) < 0)
+		return error;
+
+	gitno_buffer_setup_fromstream(s->io, &buf, buffer, buf_size);
+
+	if ((error = gitno_recv(&buf)) < 0)
+		return error;
+
+	*bytes_read = buf.offset;
+
+	return 0;
+}
+
+static int git_proto_stream_write(
+	git_smart_subtransport_stream *stream,
+	const char *buffer,
+	size_t len)
+{
+	int error;
+	git_proto_stream *s = (git_proto_stream *)stream;
+
+	if (!s->sent_command && (error = send_command(s)) < 0)
+		return error;
+
+	return git_stream_write(s->io, buffer, len, 0);
+}
+
+static void git_proto_stream_free(git_smart_subtransport_stream *stream)
+{
+	git_proto_stream *s;
+	git_subtransport *t;
+
+	if (!stream)
+		return;
+
+	s = (git_proto_stream *)stream;
+	t = OWNING_SUBTRANSPORT(s);
+
+	t->current_stream = NULL;
+
+	git_stream_close(s->io);
+	git_stream_free(s->io);
+	git__free(s->url);
+	git__free(s);
+}
+
+static int git_proto_stream_alloc(
+	git_subtransport *t,
+	const char *url,
+	const char *cmd,
+	const char *host,
+	const char *port,
+	git_smart_subtransport_stream **stream)
+{
+	git_proto_stream *s;
+
+	if (!stream)
+		return -1;
+
+	s = git__calloc(1, sizeof(git_proto_stream));
+	GITERR_CHECK_ALLOC(s);
+
+	s->parent.subtransport = &t->parent;
+	s->parent.read = git_proto_stream_read;
+	s->parent.write = git_proto_stream_write;
+	s->parent.free = git_proto_stream_free;
+
+	s->cmd = cmd;
+	s->url = git__strdup(url);
+
+	if (!s->url) {
+		git__free(s);
+		return -1;
+	}
+
+	if ((git_socket_stream_new(&s->io, host, port)) < 0)
+		return -1;
+
+	GITERR_CHECK_VERSION(s->io, GIT_STREAM_VERSION, "git_stream");
+
+	*stream = &s->parent;
+	return 0;
+}
+
+static int _git_uploadpack_ls(
+	git_subtransport *t,
+	const char *url,
+	git_smart_subtransport_stream **stream)
+{
+	char *host=NULL, *port=NULL, *path=NULL, *user=NULL, *pass=NULL;
+	const char *stream_url = url;
+	git_proto_stream *s;
+	int error;
+
+	*stream = NULL;
+
+	if (!git__prefixcmp(url, prefix_git))
+		stream_url += strlen(prefix_git);
+
+	if ((error = gitno_extract_url_parts(&host, &port, &path, &user, &pass, url, GIT_DEFAULT_PORT)) < 0)
+		return error;
+
+	error = git_proto_stream_alloc(t, stream_url, cmd_uploadpack, host, port, stream);
+
+	git__free(host);
+	git__free(port);
+	git__free(path);
+	git__free(user);
+	git__free(pass);
+
+
+	if (error < 0) {
+		git_proto_stream_free(*stream);
+		return error;
+	}
+
+	s = (git_proto_stream *) *stream;
+	if ((error = git_stream_connect(s->io)) < 0) {
+		git_proto_stream_free(*stream);
+		return error;
+	}
+
+	t->current_stream = s;
+
+	return 0;
+}
+
+static int _git_uploadpack(
+	git_subtransport *t,
+	const char *url,
+	git_smart_subtransport_stream **stream)
+{
+	GIT_UNUSED(url);
+
+	if (t->current_stream) {
+		*stream = &t->current_stream->parent;
+		return 0;
+	}
+
+	giterr_set(GITERR_NET, "must call UPLOADPACK_LS before UPLOADPACK");
+	return -1;
+}
+
+static int _git_receivepack_ls(
+	git_subtransport *t,
+	const char *url,
+	git_smart_subtransport_stream **stream)
+{
+	char *host=NULL, *port=NULL, *path=NULL, *user=NULL, *pass=NULL;
+	const char *stream_url = url;
+	git_proto_stream *s;
+	int error;
+
+	*stream = NULL;
+	if (!git__prefixcmp(url, prefix_git))
+		stream_url += strlen(prefix_git);
+
+	if ((error = gitno_extract_url_parts(&host, &port, &path, &user, &pass, url, GIT_DEFAULT_PORT)) < 0)
+		return error;
+
+	error = git_proto_stream_alloc(t, stream_url, cmd_receivepack, host, port, stream);
+
+	git__free(host);
+	git__free(port);
+	git__free(path);
+	git__free(user);
+	git__free(pass);
+
+	if (error < 0) {
+		git_proto_stream_free(*stream);
+		return error;
+	}
+
+	s = (git_proto_stream *) *stream;
+
+	if ((error = git_stream_connect(s->io)) < 0)
+		return error;
+
+	t->current_stream = s;
+
+	return 0;
+}
+
+static int _git_receivepack(
+	git_subtransport *t,
+	const char *url,
+	git_smart_subtransport_stream **stream)
+{
+	GIT_UNUSED(url);
+
+	if (t->current_stream) {
+		*stream = &t->current_stream->parent;
+		return 0;
+	}
+
+	giterr_set(GITERR_NET, "must call RECEIVEPACK_LS before RECEIVEPACK");
+	return -1;
+}
+
+static int _git_action(
+	git_smart_subtransport_stream **stream,
+	git_smart_subtransport *subtransport,
+	const char *url,
+	git_smart_service_t action)
+{
+	git_subtransport *t = (git_subtransport *) subtransport;
+
+	switch (action) {
+		case GIT_SERVICE_UPLOADPACK_LS:
+			return _git_uploadpack_ls(t, url, stream);
+
+		case GIT_SERVICE_UPLOADPACK:
+			return _git_uploadpack(t, url, stream);
+
+		case GIT_SERVICE_RECEIVEPACK_LS:
+			return _git_receivepack_ls(t, url, stream);
+
+		case GIT_SERVICE_RECEIVEPACK:
+			return _git_receivepack(t, url, stream);
+	}
+
+	*stream = NULL;
+	return -1;
+}
+
+static int _git_close(git_smart_subtransport *subtransport)
+{
+	git_subtransport *t = (git_subtransport *) subtransport;
+
+	assert(!t->current_stream);
+
+	GIT_UNUSED(t);
+
+	return 0;
+}
+
+static void _git_free(git_smart_subtransport *subtransport)
+{
+	git_subtransport *t = (git_subtransport *) subtransport;
+
+	assert(!t->current_stream);
+
+	git__free(t);
+}
+
+int git_smart_subtransport_git(git_smart_subtransport **out, git_transport *owner, void *param)
+{
+	git_subtransport *t;
+
+	GIT_UNUSED(param);
+
+	if (!out)
+		return -1;
+
+	t = git__calloc(1, sizeof(git_subtransport));
+	GITERR_CHECK_ALLOC(t);
+
+	t->owner = owner;
+	t->parent.action = _git_action;
+	t->parent.close = _git_close;
+	t->parent.free = _git_free;
+
+	*out = (git_smart_subtransport *) t;
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/transports/http.c

diff --git a/vendor/libgit2-sys/libgit2/src/transports/http.c b/vendor/libgit2-sys/libgit2/src/transports/http.c
new file mode 100644
index 0000000..e051c8a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transports/http.c
@@ -0,0 +1,1105 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#ifndef GIT_WINHTTP
+
+#include "git2.h"
+#include "http_parser.h"
+#include "buffer.h"
+#include "netops.h"
+#include "global.h"
+#include "remote.h"
+#include "smart.h"
+#include "auth.h"
+#include "http.h"
+#include "auth_negotiate.h"
+#include "streams/tls.h"
+#include "streams/socket.h"
+#include "streams/curl.h"
+
+git_http_auth_scheme auth_schemes[] = {
+	{ GIT_AUTHTYPE_NEGOTIATE, "Negotiate", GIT_CREDTYPE_DEFAULT, git_http_auth_negotiate },
+	{ GIT_AUTHTYPE_BASIC, "Basic", GIT_CREDTYPE_USERPASS_PLAINTEXT, git_http_auth_basic },
+};
+
+static const char *upload_pack_service = "upload-pack";
+static const char *upload_pack_ls_service_url = "/info/refs?service=git-upload-pack";
+static const char *upload_pack_service_url = "/git-upload-pack";
+static const char *receive_pack_service = "receive-pack";
+static const char *receive_pack_ls_service_url = "/info/refs?service=git-receive-pack";
+static const char *receive_pack_service_url = "/git-receive-pack";
+static const char *get_verb = "GET";
+static const char *post_verb = "POST";
+
+#define OWNING_SUBTRANSPORT(s) ((http_subtransport *)(s)->parent.subtransport)
+
+#define PARSE_ERROR_GENERIC	-1
+#define PARSE_ERROR_REPLAY	-2
+/** Look at the user field */
+#define PARSE_ERROR_EXT         -3
+
+#define CHUNK_SIZE	4096
+
+enum last_cb {
+	NONE,
+	FIELD,
+	VALUE
+};
+
+typedef struct {
+	git_smart_subtransport_stream parent;
+	const char *service;
+	const char *service_url;
+	char *redirect_url;
+	const char *verb;
+	char *chunk_buffer;
+	unsigned chunk_buffer_len;
+	unsigned sent_request : 1,
+		received_response : 1,
+		chunked : 1,
+		redirect_count : 3;
+} http_stream;
+
+typedef struct {
+	git_smart_subtransport parent;
+	transport_smart *owner;
+	git_stream *io;
+	gitno_connection_data connection_data;
+	bool connected;
+
+	/* Parser structures */
+	http_parser parser;
+	http_parser_settings settings;
+	gitno_buffer parse_buffer;
+	git_buf parse_header_name;
+	git_buf parse_header_value;
+	char parse_buffer_data[NETIO_BUFSIZE];
+	char *content_type;
+	char *location;
+	git_vector www_authenticate;
+	enum last_cb last_cb;
+	int parse_error;
+	int error;
+	unsigned parse_finished : 1;
+
+	/* Authentication */
+	git_cred *cred;
+	git_cred *url_cred;
+	git_vector auth_contexts;
+} http_subtransport;
+
+typedef struct {
+	http_stream *s;
+	http_subtransport *t;
+
+	/* Target buffer details from read() */
+	char *buffer;
+	size_t buf_size;
+	size_t *bytes_read;
+} parser_context;
+
+static bool credtype_match(git_http_auth_scheme *scheme, void *data)
+{
+	unsigned int credtype = *(unsigned int *)data;
+
+	return !!(scheme->credtypes & credtype);
+}
+
+static bool challenge_match(git_http_auth_scheme *scheme, void *data)
+{
+	const char *scheme_name = scheme->name;
+	const char *challenge = (const char *)data;
+	size_t scheme_len;
+
+	scheme_len = strlen(scheme_name);
+	return (strncasecmp(challenge, scheme_name, scheme_len) == 0 &&
+		(challenge[scheme_len] == '\0' || challenge[scheme_len] == ' '));
+}
+
+static int auth_context_match(
+	git_http_auth_context **out,
+	http_subtransport *t,
+	bool (*scheme_match)(git_http_auth_scheme *scheme, void *data),
+	void *data)
+{
+	git_http_auth_scheme *scheme = NULL;
+	git_http_auth_context *context = NULL, *c;
+	size_t i;
+
+	*out = NULL;
+
+	for (i = 0; i < ARRAY_SIZE(auth_schemes); i++) {
+		if (scheme_match(&auth_schemes[i], data)) {
+			scheme = &auth_schemes[i];
+			break;
+		}
+	}
+
+	if (!scheme)
+		return 0;
+
+	/* See if authentication has already started for this scheme */
+	git_vector_foreach(&t->auth_contexts, i, c) {
+		if (c->type == scheme->type) {
+			context = c;
+			break;
+		}
+	}
+
+	if (!context) {
+		if (scheme->init_context(&context, &t->connection_data) < 0)
+			return -1;
+		else if (!context)
+			return 0;
+		else if (git_vector_insert(&t->auth_contexts, context) < 0)
+			return -1;
+	}
+
+	*out = context;
+
+	return 0;
+}
+
+static int apply_credentials(git_buf *buf, http_subtransport *t)
+{
+	git_cred *cred = t->cred;
+	git_http_auth_context *context;
+
+	/* Apply the credentials given to us in the URL */
+	if (!cred && t->connection_data.user && t->connection_data.pass) {
+		if (!t->url_cred &&
+			git_cred_userpass_plaintext_new(&t->url_cred,
+				t->connection_data.user, t->connection_data.pass) < 0)
+			return -1;
+
+		cred = t->url_cred;
+	}
+
+	if (!cred)
+		return 0;
+
+	/* Get or create a context for the best scheme for this cred type */
+	if (auth_context_match(&context, t, credtype_match, &cred->credtype) < 0)
+		return -1;
+
+	return context->next_token(buf, context, cred);
+}
+
+static int gen_request(
+	git_buf *buf,
+	http_stream *s,
+	size_t content_length)
+{
+	http_subtransport *t = OWNING_SUBTRANSPORT(s);
+	const char *path = t->connection_data.path ? t->connection_data.path : "/";
+	size_t i;
+
+	git_buf_printf(buf, "%s %s%s HTTP/1.1\r\n", s->verb, path, s->service_url);
+
+	git_buf_puts(buf, "User-Agent: ");
+	git_http__user_agent(buf);
+	git_buf_puts(buf, "\r\n");
+	git_buf_printf(buf, "Host: %s\r\n", t->connection_data.host);
+
+	if (s->chunked || content_length > 0) {
+		git_buf_printf(buf, "Accept: application/x-git-%s-result\r\n", s->service);
+		git_buf_printf(buf, "Content-Type: application/x-git-%s-request\r\n", s->service);
+
+		if (s->chunked)
+			git_buf_puts(buf, "Transfer-Encoding: chunked\r\n");
+		else
+			git_buf_printf(buf, "Content-Length: %"PRIuZ "\r\n", content_length);
+	} else
+		git_buf_puts(buf, "Accept: */*\r\n");
+
+	for (i = 0; i < t->owner->custom_headers.count; i++) {
+		if (t->owner->custom_headers.strings[i])
+			git_buf_printf(buf, "%s\r\n", t->owner->custom_headers.strings[i]);
+	}
+
+	/* Apply credentials to the request */
+	if (apply_credentials(buf, t) < 0)
+		return -1;
+
+	git_buf_puts(buf, "\r\n");
+
+	if (git_buf_oom(buf))
+		return -1;
+
+	return 0;
+}
+
+static int parse_authenticate_response(
+	git_vector *www_authenticate,
+	http_subtransport *t,
+	int *allowed_types)
+{
+	git_http_auth_context *context;
+	char *challenge;
+	size_t i;
+
+	git_vector_foreach(www_authenticate, i, challenge) {
+		if (auth_context_match(&context, t, challenge_match, challenge) < 0)
+			return -1;
+		else if (!context)
+			continue;
+
+		if (context->set_challenge &&
+			context->set_challenge(context, challenge) < 0)
+			return -1;
+
+		*allowed_types |= context->credtypes;
+	}
+
+	return 0;
+}
+
+static int on_header_ready(http_subtransport *t)
+{
+	git_buf *name = &t->parse_header_name;
+	git_buf *value = &t->parse_header_value;
+
+	if (!strcasecmp("Content-Type", git_buf_cstr(name))) {
+		if (!t->content_type) {
+			t->content_type = git__strdup(git_buf_cstr(value));
+			GITERR_CHECK_ALLOC(t->content_type);
+		}
+	}
+	else if (!strcasecmp("WWW-Authenticate", git_buf_cstr(name))) {
+		char *dup = git__strdup(git_buf_cstr(value));
+		GITERR_CHECK_ALLOC(dup);
+
+		git_vector_insert(&t->www_authenticate, dup);
+	}
+	else if (!strcasecmp("Location", git_buf_cstr(name))) {
+		if (!t->location) {
+			t->location = git__strdup(git_buf_cstr(value));
+			GITERR_CHECK_ALLOC(t->location);
+		}
+	}
+
+	return 0;
+}
+
+static int on_header_field(http_parser *parser, const char *str, size_t len)
+{
+	parser_context *ctx = (parser_context *) parser->data;
+	http_subtransport *t = ctx->t;
+
+	/* Both parse_header_name and parse_header_value are populated
+	 * and ready for consumption */
+	if (VALUE == t->last_cb)
+		if (on_header_ready(t) < 0)
+			return t->parse_error = PARSE_ERROR_GENERIC;
+
+	if (NONE == t->last_cb || VALUE == t->last_cb)
+		git_buf_clear(&t->parse_header_name);
+
+	if (git_buf_put(&t->parse_header_name, str, len) < 0)
+		return t->parse_error = PARSE_ERROR_GENERIC;
+
+	t->last_cb = FIELD;
+	return 0;
+}
+
+static int on_header_value(http_parser *parser, const char *str, size_t len)
+{
+	parser_context *ctx = (parser_context *) parser->data;
+	http_subtransport *t = ctx->t;
+
+	assert(NONE != t->last_cb);
+
+	if (FIELD == t->last_cb)
+		git_buf_clear(&t->parse_header_value);
+
+	if (git_buf_put(&t->parse_header_value, str, len) < 0)
+		return t->parse_error = PARSE_ERROR_GENERIC;
+
+	t->last_cb = VALUE;
+	return 0;
+}
+
+static int on_headers_complete(http_parser *parser)
+{
+	parser_context *ctx = (parser_context *) parser->data;
+	http_subtransport *t = ctx->t;
+	http_stream *s = ctx->s;
+	git_buf buf = GIT_BUF_INIT;
+	int error = 0, no_callback = 0, allowed_auth_types = 0;
+
+	/* Both parse_header_name and parse_header_value are populated
+	 * and ready for consumption. */
+	if (VALUE == t->last_cb)
+		if (on_header_ready(t) < 0)
+			return t->parse_error = PARSE_ERROR_GENERIC;
+
+	/* Capture authentication headers which may be a 401 (authentication
+	 * is not complete) or a 200 (simply informing us that auth *is*
+	 * complete.)
+	 */
+	if (parse_authenticate_response(&t->www_authenticate, t,
+			&allowed_auth_types) < 0)
+		return t->parse_error = PARSE_ERROR_GENERIC;
+
+	/* Check for an authentication failure. */
+	if (parser->status_code == 401 && get_verb == s->verb) {
+		if (!t->owner->cred_acquire_cb) {
+			no_callback = 1;
+		} else {
+			if (allowed_auth_types) {
+				if (t->cred) {
+					t->cred->free(t->cred);
+					t->cred = NULL;
+				}
+
+				error = t->owner->cred_acquire_cb(&t->cred,
+								  t->owner->url,
+								  t->connection_data.user,
+								  allowed_auth_types,
+								  t->owner->cred_acquire_payload);
+
+				if (error == GIT_PASSTHROUGH) {
+					no_callback = 1;
+				} else if (error < 0) {
+					t->error = error;
+					return t->parse_error = PARSE_ERROR_EXT;
+				} else {
+					assert(t->cred);
+
+					if (!(t->cred->credtype & allowed_auth_types)) {
+						giterr_set(GITERR_NET, "credentials callback returned an invalid cred type");
+						return t->parse_error = PARSE_ERROR_GENERIC;
+					}
+
+					/* Successfully acquired a credential. */
+					t->parse_error = PARSE_ERROR_REPLAY;
+					return 0;
+				}
+			}
+		}
+
+		if (no_callback) {
+			giterr_set(GITERR_NET, "authentication required but no callback set");
+			return t->parse_error = PARSE_ERROR_GENERIC;
+		}
+	}
+
+	/* Check for a redirect.
+	 * Right now we only permit a redirect to the same hostname. */
+	if ((parser->status_code == 301 ||
+	     parser->status_code == 302 ||
+	     (parser->status_code == 303 && get_verb == s->verb) ||
+	     parser->status_code == 307) &&
+	    t->location) {
+
+		if (s->redirect_count >= 7) {
+			giterr_set(GITERR_NET, "too many redirects");
+			return t->parse_error = PARSE_ERROR_GENERIC;
+		}
+
+		if (gitno_connection_data_from_url(&t->connection_data, t->location, s->service_url) < 0)
+			return t->parse_error = PARSE_ERROR_GENERIC;
+
+		/* Set the redirect URL on the stream. This is a transfer of
+		 * ownership of the memory. */
+		if (s->redirect_url)
+			git__free(s->redirect_url);
+
+		s->redirect_url = t->location;
+		t->location = NULL;
+
+		t->connected = 0;
+		s->redirect_count++;
+
+		t->parse_error = PARSE_ERROR_REPLAY;
+		return 0;
+	}
+
+	/* Check for a 200 HTTP status code. */
+	if (parser->status_code != 200) {
+		giterr_set(GITERR_NET,
+			"unexpected HTTP status code: %d",
+			parser->status_code);
+		return t->parse_error = PARSE_ERROR_GENERIC;
+	}
+
+	/* The response must contain a Content-Type header. */
+	if (!t->content_type) {
+		giterr_set(GITERR_NET, "no Content-Type header in response");
+		return t->parse_error = PARSE_ERROR_GENERIC;
+	}
+
+	/* The Content-Type header must match our expectation. */
+	if (get_verb == s->verb)
+		git_buf_printf(&buf,
+			"application/x-git-%s-advertisement",
+			ctx->s->service);
+	else
+		git_buf_printf(&buf,
+			"application/x-git-%s-result",
+			ctx->s->service);
+
+	if (git_buf_oom(&buf))
+		return t->parse_error = PARSE_ERROR_GENERIC;
+
+	if (strcmp(t->content_type, git_buf_cstr(&buf))) {
+		git_buf_free(&buf);
+		giterr_set(GITERR_NET,
+			"invalid Content-Type: %s",
+			t->content_type);
+		return t->parse_error = PARSE_ERROR_GENERIC;
+	}
+
+	git_buf_free(&buf);
+
+	return 0;
+}
+
+static int on_message_complete(http_parser *parser)
+{
+	parser_context *ctx = (parser_context *) parser->data;
+	http_subtransport *t = ctx->t;
+
+	t->parse_finished = 1;
+
+	return 0;
+}
+
+static int on_body_fill_buffer(http_parser *parser, const char *str, size_t len)
+{
+	parser_context *ctx = (parser_context *) parser->data;
+	http_subtransport *t = ctx->t;
+
+	/* If our goal is to replay the request (either an auth failure or
+	 * a redirect) then don't bother buffering since we're ignoring the
+	 * content anyway.
+	 */
+	if (t->parse_error == PARSE_ERROR_REPLAY)
+		return 0;
+
+	if (ctx->buf_size < len) {
+		giterr_set(GITERR_NET, "can't fit data in the buffer");
+		return t->parse_error = PARSE_ERROR_GENERIC;
+	}
+
+	memcpy(ctx->buffer, str, len);
+	*(ctx->bytes_read) += len;
+	ctx->buffer += len;
+	ctx->buf_size -= len;
+
+	return 0;
+}
+
+static void clear_parser_state(http_subtransport *t)
+{
+	http_parser_init(&t->parser, HTTP_RESPONSE);
+	gitno_buffer_setup_fromstream(t->io,
+		&t->parse_buffer,
+		t->parse_buffer_data,
+		sizeof(t->parse_buffer_data));
+
+	t->last_cb = NONE;
+	t->parse_error = 0;
+	t->parse_finished = 0;
+
+	git_buf_free(&t->parse_header_name);
+	git_buf_init(&t->parse_header_name, 0);
+
+	git_buf_free(&t->parse_header_value);
+	git_buf_init(&t->parse_header_value, 0);
+
+	git__free(t->content_type);
+	t->content_type = NULL;
+
+	git__free(t->location);
+	t->location = NULL;
+
+	git_vector_free_deep(&t->www_authenticate);
+}
+
+static int write_chunk(git_stream *io, const char *buffer, size_t len)
+{
+	git_buf buf = GIT_BUF_INIT;
+
+	/* Chunk header */
+	git_buf_printf(&buf, "%" PRIxZ "\r\n", len);
+
+	if (git_buf_oom(&buf))
+		return -1;
+
+	if (git_stream_write(io, buf.ptr, buf.size, 0) < 0) {
+		git_buf_free(&buf);
+		return -1;
+	}
+
+	git_buf_free(&buf);
+
+	/* Chunk body */
+	if (len > 0 && git_stream_write(io, buffer, len, 0) < 0)
+		return -1;
+
+	/* Chunk footer */
+	if (git_stream_write(io, "\r\n", 2, 0) < 0)
+		return -1;
+
+	return 0;
+}
+
+static int apply_proxy_config(http_subtransport *t)
+{
+	int error;
+	git_proxy_t proxy_type;
+
+	if (!git_stream_supports_proxy(t->io))
+		return 0;
+
+	proxy_type = t->owner->proxy.type;
+
+	if (proxy_type == GIT_PROXY_NONE)
+		return 0;
+
+	if (proxy_type == GIT_PROXY_AUTO) {
+		char *url;
+		git_proxy_options opts = GIT_PROXY_OPTIONS_INIT;
+
+		if ((error = git_remote__get_http_proxy(t->owner->owner, !!t->connection_data.use_ssl, &url)) < 0)
+			return error;
+
+		opts.credentials = t->owner->proxy.credentials;
+		opts.certificate_check = t->owner->proxy.certificate_check;
+		opts.payload = t->owner->proxy.payload;
+		opts.type = GIT_PROXY_SPECIFIED;
+		opts.url = url;
+		error = git_stream_set_proxy(t->io, &opts);
+		git__free(url);
+
+		return error;
+	}
+
+	return git_stream_set_proxy(t->io, &t->owner->proxy);
+}
+
+static int http_connect(http_subtransport *t)
+{
+	int error;
+
+	if (t->connected &&
+		http_should_keep_alive(&t->parser) &&
+		t->parse_finished)
+		return 0;
+
+	if (t->io) {
+		git_stream_close(t->io);
+		git_stream_free(t->io);
+		t->io = NULL;
+		t->connected = 0;
+	}
+
+	if (t->connection_data.use_ssl) {
+		error = git_tls_stream_new(&t->io, t->connection_data.host, t->connection_data.port);
+	} else {
+#ifdef GIT_CURL
+		error = git_curl_stream_new(&t->io, t->connection_data.host, t->connection_data.port);
+#else
+		error = git_socket_stream_new(&t->io,  t->connection_data.host, t->connection_data.port);
+#endif
+	}
+
+	if (error < 0)
+		return error;
+
+	GITERR_CHECK_VERSION(t->io, GIT_STREAM_VERSION, "git_stream");
+
+	apply_proxy_config(t);
+
+	error = git_stream_connect(t->io);
+
+	if ((!error || error == GIT_ECERTIFICATE) && t->owner->certificate_check_cb != NULL &&
+	    git_stream_is_encrypted(t->io)) {
+		git_cert *cert;
+		int is_valid = (error == GIT_OK);
+
+		if ((error = git_stream_certificate(&cert, t->io)) < 0)
+			return error;
+
+		giterr_clear();
+		error = t->owner->certificate_check_cb(cert, is_valid, t->connection_data.host, t->owner->message_cb_payload);
+
+		if (error < 0) {
+			if (!giterr_last())
+				giterr_set(GITERR_NET, "user cancelled certificate check");
+
+			return error;
+		}
+	}
+
+	if (error < 0)
+		return error;
+
+	t->connected = 1;
+	return 0;
+}
+
+static int http_stream_read(
+	git_smart_subtransport_stream *stream,
+	char *buffer,
+	size_t buf_size,
+	size_t *bytes_read)
+{
+	http_stream *s = (http_stream *)stream;
+	http_subtransport *t = OWNING_SUBTRANSPORT(s);
+	parser_context ctx;
+	size_t bytes_parsed;
+
+replay:
+	*bytes_read = 0;
+
+	assert(t->connected);
+
+	if (!s->sent_request) {
+		git_buf request = GIT_BUF_INIT;
+
+		clear_parser_state(t);
+
+		if (gen_request(&request, s, 0) < 0)
+			return -1;
+
+		if (git_stream_write(t->io, request.ptr, request.size, 0) < 0) {
+			git_buf_free(&request);
+			return -1;
+		}
+
+		git_buf_free(&request);
+
+		s->sent_request = 1;
+	}
+
+	if (!s->received_response) {
+		if (s->chunked) {
+			assert(s->verb == post_verb);
+
+			/* Flush, if necessary */
+			if (s->chunk_buffer_len > 0 &&
+				write_chunk(t->io, s->chunk_buffer, s->chunk_buffer_len) < 0)
+				return -1;
+
+			s->chunk_buffer_len = 0;
+
+			/* Write the final chunk. */
+			if (git_stream_write(t->io, "0\r\n\r\n", 5, 0) < 0)
+				return -1;
+		}
+
+		s->received_response = 1;
+	}
+
+	while (!*bytes_read && !t->parse_finished) {
+		size_t data_offset;
+		int error;
+
+		/*
+		 * Make the parse_buffer think it's as full of data as
+		 * the buffer, so it won't try to recv more data than
+		 * we can put into it.
+		 *
+		 * data_offset is the actual data offset from which we
+		 * should tell the parser to start reading.
+		 */
+		if (buf_size >= t->parse_buffer.len) {
+			t->parse_buffer.offset = 0;
+		} else {
+			t->parse_buffer.offset = t->parse_buffer.len - buf_size;
+		}
+
+		data_offset = t->parse_buffer.offset;
+
+		if (gitno_recv(&t->parse_buffer) < 0)
+			return -1;
+
+		/* This call to http_parser_execute will result in invocations of the
+		 * on_* family of callbacks. The most interesting of these is
+		 * on_body_fill_buffer, which is called when data is ready to be copied
+		 * into the target buffer. We need to marshal the buffer, buf_size, and
+		 * bytes_read parameters to this callback. */
+		ctx.t = t;
+		ctx.s = s;
+		ctx.buffer = buffer;
+		ctx.buf_size = buf_size;
+		ctx.bytes_read = bytes_read;
+
+		/* Set the context, call the parser, then unset the context. */
+		t->parser.data = &ctx;
+
+		bytes_parsed = http_parser_execute(&t->parser,
+			&t->settings,
+			t->parse_buffer.data + data_offset,
+			t->parse_buffer.offset - data_offset);
+
+		t->parser.data = NULL;
+
+		/* If there was a handled authentication failure, then parse_error
+		 * will have signaled us that we should replay the request. */
+		if (PARSE_ERROR_REPLAY == t->parse_error) {
+			s->sent_request = 0;
+
+			if ((error = http_connect(t)) < 0)
+				return error;
+
+			goto replay;
+		}
+
+		if (t->parse_error == PARSE_ERROR_EXT) {
+			return t->error;
+		}
+
+		if (t->parse_error < 0)
+			return -1;
+
+		if (bytes_parsed != t->parse_buffer.offset - data_offset) {
+			giterr_set(GITERR_NET,
+				"HTTP parser error: %s",
+				http_errno_description((enum http_errno)t->parser.http_errno));
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+static int http_stream_write_chunked(
+	git_smart_subtransport_stream *stream,
+	const char *buffer,
+	size_t len)
+{
+	http_stream *s = (http_stream *)stream;
+	http_subtransport *t = OWNING_SUBTRANSPORT(s);
+
+	assert(t->connected);
+
+	/* Send the request, if necessary */
+	if (!s->sent_request) {
+		git_buf request = GIT_BUF_INIT;
+
+		clear_parser_state(t);
+
+		if (gen_request(&request, s, 0) < 0)
+			return -1;
+
+		if (git_stream_write(t->io, request.ptr, request.size, 0) < 0) {
+			git_buf_free(&request);
+			return -1;
+		}
+
+		git_buf_free(&request);
+
+		s->sent_request = 1;
+	}
+
+	if (len > CHUNK_SIZE) {
+		/* Flush, if necessary */
+		if (s->chunk_buffer_len > 0) {
+			if (write_chunk(t->io, s->chunk_buffer, s->chunk_buffer_len) < 0)
+				return -1;
+
+			s->chunk_buffer_len = 0;
+		}
+
+		/* Write chunk directly */
+		if (write_chunk(t->io, buffer, len) < 0)
+			return -1;
+	}
+	else {
+		/* Append as much to the buffer as we can */
+		int count = min(CHUNK_SIZE - s->chunk_buffer_len, len);
+
+		if (!s->chunk_buffer)
+			s->chunk_buffer = git__malloc(CHUNK_SIZE);
+
+		memcpy(s->chunk_buffer + s->chunk_buffer_len, buffer, count);
+		s->chunk_buffer_len += count;
+		buffer += count;
+		len -= count;
+
+		/* Is the buffer full? If so, then flush */
+		if (CHUNK_SIZE == s->chunk_buffer_len) {
+			if (write_chunk(t->io, s->chunk_buffer, s->chunk_buffer_len) < 0)
+				return -1;
+
+			s->chunk_buffer_len = 0;
+
+			if (len > 0) {
+				memcpy(s->chunk_buffer, buffer, len);
+				s->chunk_buffer_len = len;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int http_stream_write_single(
+	git_smart_subtransport_stream *stream,
+	const char *buffer,
+	size_t len)
+{
+	http_stream *s = (http_stream *)stream;
+	http_subtransport *t = OWNING_SUBTRANSPORT(s);
+	git_buf request = GIT_BUF_INIT;
+
+	assert(t->connected);
+
+	if (s->sent_request) {
+		giterr_set(GITERR_NET, "subtransport configured for only one write");
+		return -1;
+	}
+
+	clear_parser_state(t);
+
+	if (gen_request(&request, s, len) < 0)
+		return -1;
+
+	if (git_stream_write(t->io, request.ptr, request.size, 0) < 0)
+		goto on_error;
+
+	if (len && git_stream_write(t->io, buffer, len, 0) < 0)
+		goto on_error;
+
+	git_buf_free(&request);
+	s->sent_request = 1;
+
+	return 0;
+
+on_error:
+	git_buf_free(&request);
+	return -1;
+}
+
+static void http_stream_free(git_smart_subtransport_stream *stream)
+{
+	http_stream *s = (http_stream *)stream;
+
+	if (s->chunk_buffer)
+		git__free(s->chunk_buffer);
+
+	if (s->redirect_url)
+		git__free(s->redirect_url);
+
+	git__free(s);
+}
+
+static int http_stream_alloc(http_subtransport *t,
+	git_smart_subtransport_stream **stream)
+{
+	http_stream *s;
+
+	if (!stream)
+		return -1;
+
+	s = git__calloc(sizeof(http_stream), 1);
+	GITERR_CHECK_ALLOC(s);
+
+	s->parent.subtransport = &t->parent;
+	s->parent.read = http_stream_read;
+	s->parent.write = http_stream_write_single;
+	s->parent.free = http_stream_free;
+
+	*stream = (git_smart_subtransport_stream *)s;
+	return 0;
+}
+
+static int http_uploadpack_ls(
+	http_subtransport *t,
+	git_smart_subtransport_stream **stream)
+{
+	http_stream *s;
+
+	if (http_stream_alloc(t, stream) < 0)
+		return -1;
+
+	s = (http_stream *)*stream;
+
+	s->service = upload_pack_service;
+	s->service_url = upload_pack_ls_service_url;
+	s->verb = get_verb;
+
+	return 0;
+}
+
+static int http_uploadpack(
+	http_subtransport *t,
+	git_smart_subtransport_stream **stream)
+{
+	http_stream *s;
+
+	if (http_stream_alloc(t, stream) < 0)
+		return -1;
+
+	s = (http_stream *)*stream;
+
+	s->service = upload_pack_service;
+	s->service_url = upload_pack_service_url;
+	s->verb = post_verb;
+
+	return 0;
+}
+
+static int http_receivepack_ls(
+	http_subtransport *t,
+	git_smart_subtransport_stream **stream)
+{
+	http_stream *s;
+
+	if (http_stream_alloc(t, stream) < 0)
+		return -1;
+
+	s = (http_stream *)*stream;
+
+	s->service = receive_pack_service;
+	s->service_url = receive_pack_ls_service_url;
+	s->verb = get_verb;
+
+	return 0;
+}
+
+static int http_receivepack(
+	http_subtransport *t,
+	git_smart_subtransport_stream **stream)
+{
+	http_stream *s;
+
+	if (http_stream_alloc(t, stream) < 0)
+		return -1;
+
+	s = (http_stream *)*stream;
+
+	/* Use Transfer-Encoding: chunked for this request */
+	s->chunked = 1;
+	s->parent.write = http_stream_write_chunked;
+
+	s->service = receive_pack_service;
+	s->service_url = receive_pack_service_url;
+	s->verb = post_verb;
+
+	return 0;
+}
+
+static int http_action(
+	git_smart_subtransport_stream **stream,
+	git_smart_subtransport *subtransport,
+	const char *url,
+	git_smart_service_t action)
+{
+	http_subtransport *t = (http_subtransport *)subtransport;
+	int ret;
+
+	if (!stream)
+		return -1;
+
+	if ((!t->connection_data.host || !t->connection_data.port || !t->connection_data.path) &&
+		 (ret = gitno_connection_data_from_url(&t->connection_data, url, NULL)) < 0)
+		return ret;
+
+	if ((ret = http_connect(t)) < 0)
+		return ret;
+
+	switch (action) {
+	case GIT_SERVICE_UPLOADPACK_LS:
+		return http_uploadpack_ls(t, stream);
+
+	case GIT_SERVICE_UPLOADPACK:
+		return http_uploadpack(t, stream);
+
+	case GIT_SERVICE_RECEIVEPACK_LS:
+		return http_receivepack_ls(t, stream);
+
+	case GIT_SERVICE_RECEIVEPACK:
+		return http_receivepack(t, stream);
+	}
+
+	*stream = NULL;
+	return -1;
+}
+
+static int http_close(git_smart_subtransport *subtransport)
+{
+	http_subtransport *t = (http_subtransport *) subtransport;
+	git_http_auth_context *context;
+	size_t i;
+
+	clear_parser_state(t);
+
+	t->connected = 0;
+
+	if (t->io) {
+		git_stream_close(t->io);
+		git_stream_free(t->io);
+		t->io = NULL;
+	}
+
+	if (t->cred) {
+		t->cred->free(t->cred);
+		t->cred = NULL;
+	}
+
+	if (t->url_cred) {
+		t->url_cred->free(t->url_cred);
+		t->url_cred = NULL;
+	}
+
+	git_vector_foreach(&t->auth_contexts, i, context) {
+		if (context->free)
+			context->free(context);
+	}
+
+	git_vector_clear(&t->auth_contexts);
+
+	gitno_connection_data_free_ptrs(&t->connection_data);
+	memset(&t->connection_data, 0x0, sizeof(gitno_connection_data));
+
+	return 0;
+}
+
+static void http_free(git_smart_subtransport *subtransport)
+{
+	http_subtransport *t = (http_subtransport *) subtransport;
+
+	http_close(subtransport);
+
+	git_vector_free(&t->auth_contexts);
+	git__free(t);
+}
+
+int git_smart_subtransport_http(git_smart_subtransport **out, git_transport *owner, void *param)
+{
+	http_subtransport *t;
+
+	GIT_UNUSED(param);
+
+	if (!out)
+		return -1;
+
+	t = git__calloc(sizeof(http_subtransport), 1);
+	GITERR_CHECK_ALLOC(t);
+
+	t->owner = (transport_smart *)owner;
+	t->parent.action = http_action;
+	t->parent.close = http_close;
+	t->parent.free = http_free;
+
+	t->settings.on_header_field = on_header_field;
+	t->settings.on_header_value = on_header_value;
+	t->settings.on_headers_complete = on_headers_complete;
+	t->settings.on_body = on_body_fill_buffer;
+	t->settings.on_message_complete = on_message_complete;
+
+	*out = (git_smart_subtransport *) t;
+	return 0;
+}
+
+#endif /* !GIT_WINHTTP */

vendor/libgit2-sys/libgit2/src/transports/http.h

diff --git a/vendor/libgit2-sys/libgit2/src/transports/http.h b/vendor/libgit2-sys/libgit2/src/transports/http.h
new file mode 100644
index 0000000..6c4ecc9
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transports/http.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_transports_http_h__
+#define INCLUDE_transports_http_h__
+
+#include "buffer.h"
+
+GIT_INLINE(int) git_http__user_agent(git_buf *buf)
+{
+	const char *ua = git_libgit2__user_agent();
+
+	if (!ua)
+		ua = "libgit2 " LIBGIT2_VERSION;
+
+	return git_buf_printf(buf, "git/2.0 (%s)", ua);
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/transports/local.c

diff --git a/vendor/libgit2-sys/libgit2/src/transports/local.c b/vendor/libgit2-sys/libgit2/src/transports/local.c
new file mode 100644
index 0000000..541c552
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transports/local.c
@@ -0,0 +1,746 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "git2/types.h"
+#include "git2/net.h"
+#include "git2/repository.h"
+#include "git2/object.h"
+#include "git2/tag.h"
+#include "git2/transport.h"
+#include "git2/revwalk.h"
+#include "git2/odb_backend.h"
+#include "git2/pack.h"
+#include "git2/commit.h"
+#include "git2/revparse.h"
+
+#include "pack-objects.h"
+#include "refs.h"
+#include "posix.h"
+#include "path.h"
+#include "buffer.h"
+#include "repository.h"
+#include "odb.h"
+#include "push.h"
+#include "remote.h"
+#include "proxy.h"
+
+typedef struct {
+	git_transport parent;
+	git_remote *owner;
+	char *url;
+	int direction;
+	int flags;
+	git_atomic cancelled;
+	git_repository *repo;
+	git_transport_message_cb progress_cb;
+	git_transport_message_cb error_cb;
+	void *message_cb_payload;
+	git_vector refs;
+	unsigned connected : 1,
+		have_refs : 1;
+} transport_local;
+
+static void free_head(git_remote_head *head)
+{
+	git__free(head->name);
+	git__free(head->symref_target);
+	git__free(head);
+}
+
+static void free_heads(git_vector *heads)
+{
+	git_remote_head *head;
+	size_t i;
+
+	git_vector_foreach(heads, i, head)
+		free_head(head);
+
+	git_vector_free(heads);
+}
+
+static int add_ref(transport_local *t, const char *name)
+{
+	const char peeled[] = "^{}";
+	git_reference *ref, *resolved;
+	git_remote_head *head;
+	git_oid obj_id;
+	git_object *obj = NULL, *target = NULL;
+	git_buf buf = GIT_BUF_INIT;
+	int error;
+
+	if ((error = git_reference_lookup(&ref, t->repo, name)) < 0)
+		return error;
+
+	error = git_reference_resolve(&resolved, ref);
+	if (error < 0) {
+		git_reference_free(ref);
+		if (!strcmp(name, GIT_HEAD_FILE) && error == GIT_ENOTFOUND) {
+			/* This is actually okay.  Empty repos often have a HEAD that
+			 * points to a nonexistent "refs/heads/master". */
+			giterr_clear();
+			return 0;
+		}
+		return error;
+	}
+
+	git_oid_cpy(&obj_id, git_reference_target(resolved));
+	git_reference_free(resolved);
+
+	head = git__calloc(1, sizeof(git_remote_head));
+	GITERR_CHECK_ALLOC(head);
+
+	head->name = git__strdup(name);
+	GITERR_CHECK_ALLOC(head->name);
+
+	git_oid_cpy(&head->oid, &obj_id);
+
+	if (git_reference_type(ref) == GIT_REF_SYMBOLIC) {
+		head->symref_target = git__strdup(git_reference_symbolic_target(ref));
+		GITERR_CHECK_ALLOC(head->symref_target);
+	}
+	git_reference_free(ref);
+
+	if ((error = git_vector_insert(&t->refs, head)) < 0) {
+		free_head(head);
+		return error;
+	}
+
+	/* If it's not a tag, we don't need to try to peel it */
+	if (git__prefixcmp(name, GIT_REFS_TAGS_DIR))
+		return 0;
+
+	if ((error = git_object_lookup(&obj, t->repo, &head->oid, GIT_OBJ_ANY)) < 0)
+		return error;
+
+	head = NULL;
+
+	/* If it's not an annotated tag, or if we're mocking
+	 * git-receive-pack, just get out */
+	if (git_object_type(obj) != GIT_OBJ_TAG ||
+		t->direction != GIT_DIRECTION_FETCH) {
+		git_object_free(obj);
+		return 0;
+	}
+
+	/* And if it's a tag, peel it, and add it to the list */
+	head = git__calloc(1, sizeof(git_remote_head));
+	GITERR_CHECK_ALLOC(head);
+
+	if (git_buf_join(&buf, 0, name, peeled) < 0) {
+		free_head(head);
+		return -1;
+	}
+	head->name = git_buf_detach(&buf);
+
+	if (!(error = git_tag_peel(&target, (git_tag *)obj))) {
+		git_oid_cpy(&head->oid, git_object_id(target));
+
+		if ((error = git_vector_insert(&t->refs, head)) < 0) {
+			free_head(head);
+		}
+	}
+
+	git_object_free(obj);
+	git_object_free(target);
+
+	return error;
+}
+
+static int store_refs(transport_local *t)
+{
+	size_t i;
+	git_remote_head *head;
+	git_strarray ref_names = {0};
+
+	assert(t);
+
+	if (git_reference_list(&ref_names, t->repo) < 0)
+		goto on_error;
+
+	/* Clear all heads we might have fetched in a previous connect */
+	git_vector_foreach(&t->refs, i, head) {
+		git__free(head->name);
+		git__free(head);
+	}
+
+	/* Clear the vector so we can reuse it */
+	git_vector_clear(&t->refs);
+
+	/* Sort the references first */
+	git__tsort((void **)ref_names.strings, ref_names.count, &git__strcmp_cb);
+
+	/* Add HEAD iff direction is fetch */
+	if (t->direction == GIT_DIRECTION_FETCH && add_ref(t, GIT_HEAD_FILE) < 0)
+		goto on_error;
+
+	for (i = 0; i < ref_names.count; ++i) {
+		if (add_ref(t, ref_names.strings[i]) < 0)
+			goto on_error;
+	}
+
+	t->have_refs = 1;
+	git_strarray_free(&ref_names);
+	return 0;
+
+on_error:
+	git_vector_free(&t->refs);
+	git_strarray_free(&ref_names);
+	return -1;
+}
+
+/*
+ * Try to open the url as a git directory. The direction doesn't
+ * matter in this case because we're calculating the heads ourselves.
+ */
+static int local_connect(
+	git_transport *transport,
+	const char *url,
+	git_cred_acquire_cb cred_acquire_cb,
+	void *cred_acquire_payload,
+	const git_proxy_options *proxy,
+	int direction, int flags)
+{
+	git_repository *repo;
+	int error;
+	transport_local *t = (transport_local *) transport;
+	const char *path;
+	git_buf buf = GIT_BUF_INIT;
+
+	GIT_UNUSED(cred_acquire_cb);
+	GIT_UNUSED(cred_acquire_payload);
+	GIT_UNUSED(proxy);
+
+	if (t->connected)
+		return 0;
+
+	free_heads(&t->refs);
+
+	t->url = git__strdup(url);
+	GITERR_CHECK_ALLOC(t->url);
+	t->direction = direction;
+	t->flags = flags;
+
+	/* 'url' may be a url or path; convert to a path */
+	if ((error = git_path_from_url_or_path(&buf, url)) < 0) {
+		git_buf_free(&buf);
+		return error;
+	}
+	path = git_buf_cstr(&buf);
+
+	error = git_repository_open(&repo, path);
+
+	git_buf_free(&buf);
+
+	if (error < 0)
+		return -1;
+
+	t->repo = repo;
+
+	if (store_refs(t) < 0)
+		return -1;
+
+	t->connected = 1;
+
+	return 0;
+}
+
+static int local_ls(const git_remote_head ***out, size_t *size, git_transport *transport)
+{
+	transport_local *t = (transport_local *)transport;
+
+	if (!t->have_refs) {
+		giterr_set(GITERR_NET, "the transport has not yet loaded the refs");
+		return -1;
+	}
+
+	*out = (const git_remote_head **)t->refs.contents;
+	*size = t->refs.length;
+
+	return 0;
+}
+
+static int local_negotiate_fetch(
+	git_transport *transport,
+	git_repository *repo,
+	const git_remote_head * const *refs,
+	size_t count)
+{
+	transport_local *t = (transport_local*)transport;
+	git_remote_head *rhead;
+	unsigned int i;
+
+	GIT_UNUSED(refs);
+	GIT_UNUSED(count);
+
+	/* Fill in the loids */
+	git_vector_foreach(&t->refs, i, rhead) {
+		git_object *obj;
+
+		int error = git_revparse_single(&obj, repo, rhead->name);
+		if (!error)
+			git_oid_cpy(&rhead->loid, git_object_id(obj));
+		else if (error != GIT_ENOTFOUND)
+			return error;
+		else
+			giterr_clear();
+		git_object_free(obj);
+	}
+
+	return 0;
+}
+
+static int local_push_update_remote_ref(
+	git_repository *remote_repo,
+	const char *lref,
+	const char *rref,
+	git_oid *loid,
+	git_oid *roid)
+{
+	int error;
+	git_reference *remote_ref = NULL;
+
+	/* check for lhs, if it's empty it means to delete */
+	if (lref[0] != '\0') {
+		/* Create or update a ref */
+		error = git_reference_create(NULL, remote_repo, rref, loid,
+					     !git_oid_iszero(roid), NULL);
+	} else {
+		/* Delete a ref */
+		if ((error = git_reference_lookup(&remote_ref, remote_repo, rref)) < 0) {
+			if (error == GIT_ENOTFOUND)
+				error = 0;
+			return error;
+		}
+
+		error = git_reference_delete(remote_ref);
+		git_reference_free(remote_ref);
+	}
+
+	return error;
+}
+
+static int transfer_to_push_transfer(const git_transfer_progress *stats, void *payload)
+{
+	const git_remote_callbacks *cbs = payload;
+
+	if (!cbs || !cbs->push_transfer_progress)
+		return 0;
+
+	return cbs->push_transfer_progress(stats->received_objects, stats->total_objects, stats->received_bytes,
+					   cbs->payload);
+}
+
+static int local_push(
+	git_transport *transport,
+	git_push *push,
+	const git_remote_callbacks *cbs)
+{
+	transport_local *t = (transport_local *)transport;
+	git_repository *remote_repo = NULL;
+	push_spec *spec;
+	char *url = NULL;
+	const char *path;
+	git_buf buf = GIT_BUF_INIT, odb_path = GIT_BUF_INIT;
+	int error;
+	size_t j;
+
+	GIT_UNUSED(cbs);
+
+	/* 'push->remote->url' may be a url or path; convert to a path */
+	if ((error = git_path_from_url_or_path(&buf, push->remote->url)) < 0) {
+		git_buf_free(&buf);
+		return error;
+	}
+	path = git_buf_cstr(&buf);
+
+	error = git_repository_open(&remote_repo, path);
+
+	git_buf_free(&buf);
+
+	if (error < 0)
+		return error;
+
+	/* We don't currently support pushing locally to non-bare repos. Proper
+	   non-bare repo push support would require checking configs to see if
+	   we should override the default 'don't let this happen' behavior.
+
+	   Note that this is only an issue when pushing to the current branch,
+	   but we forbid all pushes just in case */
+	if (!remote_repo->is_bare) {
+		error = GIT_EBAREREPO;
+		giterr_set(GITERR_INVALID, "local push doesn't (yet) support pushing to non-bare repos.");
+		goto on_error;
+	}
+
+	if ((error = git_repository_item_path(&odb_path, remote_repo, GIT_REPOSITORY_ITEM_OBJECTS)) < 0
+		|| (error = git_buf_joinpath(&odb_path, odb_path.ptr, "pack")) < 0)
+		goto on_error;
+
+	error = git_packbuilder_write(push->pb, odb_path.ptr, 0, transfer_to_push_transfer, (void *) cbs);
+	git_buf_free(&odb_path);
+
+	if (error < 0)
+		goto on_error;
+
+	push->unpack_ok = 1;
+
+	git_vector_foreach(&push->specs, j, spec) {
+		push_status *status;
+		const git_error *last;
+		char *ref = spec->refspec.dst;
+
+		status = git__calloc(1, sizeof(push_status));
+		if (!status)
+			goto on_error;
+
+		status->ref = git__strdup(ref);
+		if (!status->ref) {
+			git_push_status_free(status);
+			goto on_error;
+		}
+
+		error = local_push_update_remote_ref(remote_repo, spec->refspec.src, spec->refspec.dst,
+			&spec->loid, &spec->roid);
+
+		switch (error) {
+			case GIT_OK:
+				break;
+			case GIT_EINVALIDSPEC:
+				status->msg = git__strdup("funny refname");
+				break;
+			case GIT_ENOTFOUND:
+				status->msg = git__strdup("Remote branch not found to delete");
+				break;
+			default:
+				last = giterr_last();
+
+				if (last && last->message)
+					status->msg = git__strdup(last->message);
+				else
+					status->msg = git__strdup("Unspecified error encountered");
+				break;
+		}
+
+		/* failed to allocate memory for a status message */
+		if (error < 0 && !status->msg) {
+			git_push_status_free(status);
+			goto on_error;
+		}
+
+		/* failed to insert the ref update status */
+		if ((error = git_vector_insert(&push->status, status)) < 0) {
+			git_push_status_free(status);
+			goto on_error;
+		}
+	}
+
+	if (push->specs.length) {
+		int flags = t->flags;
+		url = git__strdup(t->url);
+
+		if (!url || t->parent.close(&t->parent) < 0 ||
+			t->parent.connect(&t->parent, url,
+			NULL, NULL, NULL, GIT_DIRECTION_PUSH, flags))
+			goto on_error;
+	}
+
+	error = 0;
+
+on_error:
+	git_repository_free(remote_repo);
+	git__free(url);
+
+	return error;
+}
+
+typedef struct foreach_data {
+	git_transfer_progress *stats;
+	git_transfer_progress_cb progress_cb;
+	void *progress_payload;
+	git_odb_writepack *writepack;
+} foreach_data;
+
+static int foreach_cb(void *buf, size_t len, void *payload)
+{
+	foreach_data *data = (foreach_data*)payload;
+
+	data->stats->received_bytes += len;
+	return data->writepack->append(data->writepack, buf, len, data->stats);
+}
+
+static const char *counting_objects_fmt = "Counting objects %d\r";
+static const char *compressing_objects_fmt = "Compressing objects: %.0f%% (%d/%d)";
+
+static int local_counting(int stage, unsigned int current, unsigned int total, void *payload)
+{
+	git_buf progress_info = GIT_BUF_INIT;
+	transport_local *t = payload;
+	int error;
+
+	if (!t->progress_cb)
+		return 0;
+
+	if (stage == GIT_PACKBUILDER_ADDING_OBJECTS) {
+		git_buf_printf(&progress_info, counting_objects_fmt, current);
+	} else if (stage == GIT_PACKBUILDER_DELTAFICATION) {
+		float perc = (((float) current) / total) * 100;
+		git_buf_printf(&progress_info, compressing_objects_fmt, perc, current, total);
+		if (current == total)
+			git_buf_printf(&progress_info, ", done\n");
+		else
+			git_buf_putc(&progress_info, '\r');
+
+	}
+
+	if (git_buf_oom(&progress_info))
+		return -1;
+
+	error = t->progress_cb(git_buf_cstr(&progress_info), git_buf_len(&progress_info), t->message_cb_payload);
+	git_buf_free(&progress_info);
+
+	return error;
+}
+
+static int foreach_reference_cb(git_reference *reference, void *payload)
+{
+	git_revwalk *walk = (git_revwalk *)payload;
+	int error;
+
+	if (git_reference_type(reference) != GIT_REF_OID) {
+		git_reference_free(reference);
+		return 0;
+	}
+
+	error = git_revwalk_hide(walk, git_reference_target(reference));
+	/* The reference is in the local repository, so the target may not
+	 * exist on the remote.  It also may not be a commit. */
+	if (error == GIT_ENOTFOUND || error == GITERR_INVALID) {
+		giterr_clear();
+		error = 0;
+	}
+
+	git_reference_free(reference);
+
+	return error;
+}
+
+static int local_download_pack(
+		git_transport *transport,
+		git_repository *repo,
+		git_transfer_progress *stats,
+		git_transfer_progress_cb progress_cb,
+		void *progress_payload)
+{
+	transport_local *t = (transport_local*)transport;
+	git_revwalk *walk = NULL;
+	git_remote_head *rhead;
+	unsigned int i;
+	int error = -1;
+	git_packbuilder *pack = NULL;
+	git_odb_writepack *writepack = NULL;
+	git_odb *odb = NULL;
+	git_buf progress_info = GIT_BUF_INIT;
+
+	if ((error = git_revwalk_new(&walk, t->repo)) < 0)
+		goto cleanup;
+	git_revwalk_sorting(walk, GIT_SORT_TIME);
+
+	if ((error = git_packbuilder_new(&pack, t->repo)) < 0)
+		goto cleanup;
+
+	git_packbuilder_set_callbacks(pack, local_counting, t);
+
+	stats->total_objects = 0;
+	stats->indexed_objects = 0;
+	stats->received_objects = 0;
+	stats->received_bytes = 0;
+
+	git_vector_foreach(&t->refs, i, rhead) {
+		git_object *obj;
+		if ((error = git_object_lookup(&obj, t->repo, &rhead->oid, GIT_OBJ_ANY)) < 0)
+			goto cleanup;
+
+		if (git_object_type(obj) == GIT_OBJ_COMMIT) {
+			/* Revwalker includes only wanted commits */
+			error = git_revwalk_push(walk, &rhead->oid);
+		} else {
+			/* Tag or some other wanted object. Add it on its own */
+			error = git_packbuilder_insert_recur(pack, &rhead->oid, rhead->name);
+		}
+		git_object_free(obj);
+		if (error < 0)
+			goto cleanup;
+	}
+
+	if ((error = git_reference_foreach(repo, foreach_reference_cb, walk)))
+		goto cleanup;
+
+	if ((error = git_packbuilder_insert_walk(pack, walk)))
+		goto cleanup;
+
+	if ((error = git_buf_printf(&progress_info, counting_objects_fmt, git_packbuilder_object_count(pack))) < 0)
+		goto cleanup;
+
+	if (t->progress_cb &&
+	    (error = t->progress_cb(git_buf_cstr(&progress_info), git_buf_len(&progress_info), t->message_cb_payload)) < 0)
+		goto cleanup;
+
+	/* Walk the objects, building a packfile */
+	if ((error = git_repository_odb__weakptr(&odb, repo)) < 0)
+		goto cleanup;
+
+	/* One last one with the newline */
+	git_buf_clear(&progress_info);
+	git_buf_printf(&progress_info, counting_objects_fmt, git_packbuilder_object_count(pack));
+	if ((error = git_buf_putc(&progress_info, '\n')) < 0)
+		goto cleanup;
+
+	if (t->progress_cb &&
+	    (error = t->progress_cb(git_buf_cstr(&progress_info), git_buf_len(&progress_info), t->message_cb_payload)) < 0)
+		goto cleanup;
+
+	if ((error = git_odb_write_pack(&writepack, odb, progress_cb, progress_payload)) != 0)
+		goto cleanup;
+
+	/* Write the data to the ODB */
+	{
+		foreach_data data = {0};
+		data.stats = stats;
+		data.progress_cb = progress_cb;
+		data.progress_payload = progress_payload;
+		data.writepack = writepack;
+
+		/* autodetect */
+		git_packbuilder_set_threads(pack, 0);
+
+		if ((error = git_packbuilder_foreach(pack, foreach_cb, &data)) != 0)
+			goto cleanup;
+	}
+
+	error = writepack->commit(writepack, stats);
+
+cleanup:
+	if (writepack) writepack->free(writepack);
+	git_buf_free(&progress_info);
+	git_packbuilder_free(pack);
+	git_revwalk_free(walk);
+	return error;
+}
+
+static int local_set_callbacks(
+	git_transport *transport,
+	git_transport_message_cb progress_cb,
+	git_transport_message_cb error_cb,
+	git_transport_certificate_check_cb certificate_check_cb,
+	void *message_cb_payload)
+{
+	transport_local *t = (transport_local *)transport;
+
+	GIT_UNUSED(certificate_check_cb);
+
+	t->progress_cb = progress_cb;
+	t->error_cb = error_cb;
+	t->message_cb_payload = message_cb_payload;
+
+	return 0;
+}
+
+static int local_is_connected(git_transport *transport)
+{
+	transport_local *t = (transport_local *)transport;
+
+	return t->connected;
+}
+
+static int local_read_flags(git_transport *transport, int *flags)
+{
+	transport_local *t = (transport_local *)transport;
+
+	*flags = t->flags;
+
+	return 0;
+}
+
+static void local_cancel(git_transport *transport)
+{
+	transport_local *t = (transport_local *)transport;
+
+	git_atomic_set(&t->cancelled, 1);
+}
+
+static int local_close(git_transport *transport)
+{
+	transport_local *t = (transport_local *)transport;
+
+	t->connected = 0;
+
+	if (t->repo) {
+		git_repository_free(t->repo);
+		t->repo = NULL;
+	}
+
+	if (t->url) {
+		git__free(t->url);
+		t->url = NULL;
+	}
+
+	return 0;
+}
+
+static void local_free(git_transport *transport)
+{
+	transport_local *t = (transport_local *)transport;
+
+	free_heads(&t->refs);
+
+	/* Close the transport, if it's still open. */
+	local_close(transport);
+
+	/* Free the transport */
+	git__free(t);
+}
+
+/**************
+ * Public API *
+ **************/
+
+int git_transport_local(git_transport **out, git_remote *owner, void *param)
+{
+	int error;
+	transport_local *t;
+
+	GIT_UNUSED(param);
+
+	t = git__calloc(1, sizeof(transport_local));
+	GITERR_CHECK_ALLOC(t);
+
+	t->parent.version = GIT_TRANSPORT_VERSION;
+	t->parent.set_callbacks = local_set_callbacks;
+	t->parent.connect = local_connect;
+	t->parent.negotiate_fetch = local_negotiate_fetch;
+	t->parent.download_pack = local_download_pack;
+	t->parent.push = local_push;
+	t->parent.close = local_close;
+	t->parent.free = local_free;
+	t->parent.ls = local_ls;
+	t->parent.is_connected = local_is_connected;
+	t->parent.read_flags = local_read_flags;
+	t->parent.cancel = local_cancel;
+
+	if ((error = git_vector_init(&t->refs, 0, NULL)) < 0) {
+		git__free(t);
+		return error;
+	}
+
+	t->owner = owner;
+
+	*out = (git_transport *) t;
+
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/transports/smart.c

diff --git a/vendor/libgit2-sys/libgit2/src/transports/smart.c b/vendor/libgit2-sys/libgit2/src/transports/smart.c
new file mode 100644
index 0000000..6d5d95f
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transports/smart.c
@@ -0,0 +1,528 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "smart.h"
+
+#include "git2.h"
+#include "refs.h"
+#include "refspec.h"
+#include "proxy.h"
+
+static int git_smart__recv_cb(gitno_buffer *buf)
+{
+	transport_smart *t = (transport_smart *) buf->cb_data;
+	size_t old_len, bytes_read;
+	int error;
+
+	assert(t->current_stream);
+
+	old_len = buf->offset;
+
+	if ((error = t->current_stream->read(t->current_stream, buf->data + buf->offset, buf->len - buf->offset, &bytes_read)) < 0)
+		return error;
+
+	buf->offset += bytes_read;
+
+	if (t->packetsize_cb && !t->cancelled.val) {
+		error = t->packetsize_cb(bytes_read, t->packetsize_payload);
+		if (error) {
+			git_atomic_set(&t->cancelled, 1);
+			return GIT_EUSER;
+		}
+	}
+
+	return (int)(buf->offset - old_len);
+}
+
+GIT_INLINE(int) git_smart__reset_stream(transport_smart *t, bool close_subtransport)
+{
+	if (t->current_stream) {
+		t->current_stream->free(t->current_stream);
+		t->current_stream = NULL;
+	}
+
+	if (close_subtransport &&
+		t->wrapped->close(t->wrapped) < 0)
+		return -1;
+
+	return 0;
+}
+
+static int git_smart__set_callbacks(
+	git_transport *transport,
+	git_transport_message_cb progress_cb,
+	git_transport_message_cb error_cb,
+	git_transport_certificate_check_cb certificate_check_cb,
+	void *message_cb_payload)
+{
+	transport_smart *t = (transport_smart *)transport;
+
+	t->progress_cb = progress_cb;
+	t->error_cb = error_cb;
+	t->certificate_check_cb = certificate_check_cb;
+	t->message_cb_payload = message_cb_payload;
+
+	return 0;
+}
+
+static int http_header_name_length(const char *http_header)
+{
+	const char *colon = strchr(http_header, ':');
+	if (!colon)
+		return 0;
+	return colon - http_header;
+}
+
+static bool is_malformed_http_header(const char *http_header)
+{
+	const char *c;
+	int name_len;
+
+	// Disallow \r and \n
+	c = strchr(http_header, '\r');
+	if (c)
+		return true;
+	c = strchr(http_header, '\n');
+	if (c)
+		return true;
+
+	// Require a header name followed by :
+	name_len = http_header_name_length(http_header);
+	if (name_len < 1)
+		return true;
+
+	return false;
+}
+
+static char *forbidden_custom_headers[] = {
+	"User-Agent",
+	"Host",
+	"Accept",
+	"Content-Type",
+	"Transfer-Encoding",
+	"Content-Length",
+};
+
+static bool is_forbidden_custom_header(const char *custom_header)
+{
+	unsigned long i;
+	int name_len = http_header_name_length(custom_header);
+
+	// Disallow headers that we set
+	for (i = 0; i < ARRAY_SIZE(forbidden_custom_headers); i++)
+		if (strncmp(forbidden_custom_headers[i], custom_header, name_len) == 0)
+			return true;
+
+	return false;
+}
+
+static int git_smart__set_custom_headers(
+	git_transport *transport,
+	const git_strarray *custom_headers)
+{
+	transport_smart *t = (transport_smart *)transport;
+	size_t i;
+
+	if (t->custom_headers.count)
+		git_strarray_free(&t->custom_headers);
+
+	if (!custom_headers)
+		return 0;
+
+	for (i = 0; i < custom_headers->count; i++) {
+		if (is_malformed_http_header(custom_headers->strings[i])) {
+			giterr_set(GITERR_INVALID, "custom HTTP header '%s' is malformed", custom_headers->strings[i]);
+			return -1;
+		}
+		if (is_forbidden_custom_header(custom_headers->strings[i])) {
+			giterr_set(GITERR_INVALID, "custom HTTP header '%s' is already set by libgit2", custom_headers->strings[i]);
+			return -1;
+		}
+	}
+
+	return git_strarray_copy(&t->custom_headers, custom_headers);
+}
+
+int git_smart__update_heads(transport_smart *t, git_vector *symrefs)
+{
+	size_t i;
+	git_pkt *pkt;
+
+	git_vector_clear(&t->heads);
+	git_vector_foreach(&t->refs, i, pkt) {
+		git_pkt_ref *ref = (git_pkt_ref *) pkt;
+		if (pkt->type != GIT_PKT_REF)
+			continue;
+
+		if (symrefs) {
+			git_refspec *spec;
+			git_buf buf = GIT_BUF_INIT;
+			size_t j;
+			int error = 0;
+
+			git_vector_foreach(symrefs, j, spec) {
+				git_buf_clear(&buf);
+				if (git_refspec_src_matches(spec, ref->head.name) &&
+				    !(error = git_refspec_transform(&buf, spec, ref->head.name)))
+					ref->head.symref_target = git_buf_detach(&buf);
+			}
+
+			git_buf_free(&buf);
+
+			if (error < 0)
+				return error;
+		}
+
+		if (git_vector_insert(&t->heads, &ref->head) < 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+static void free_symrefs(git_vector *symrefs)
+{
+	git_refspec *spec;
+	size_t i;
+
+	git_vector_foreach(symrefs, i, spec) {
+		git_refspec__free(spec);
+		git__free(spec);
+	}
+
+	git_vector_free(symrefs);
+}
+
+static int git_smart__connect(
+	git_transport *transport,
+	const char *url,
+	git_cred_acquire_cb cred_acquire_cb,
+	void *cred_acquire_payload,
+	const git_proxy_options *proxy,
+	int direction,
+	int flags)
+{
+	transport_smart *t = (transport_smart *)transport;
+	git_smart_subtransport_stream *stream;
+	int error;
+	git_pkt *pkt;
+	git_pkt_ref *first;
+	git_vector symrefs;
+	git_smart_service_t service;
+
+	if (git_smart__reset_stream(t, true) < 0)
+		return -1;
+
+	t->url = git__strdup(url);
+	GITERR_CHECK_ALLOC(t->url);
+
+	if (git_proxy_options_dup(&t->proxy, proxy) < 0)
+		return -1;
+
+	t->direction = direction;
+	t->flags = flags;
+	t->cred_acquire_cb = cred_acquire_cb;
+	t->cred_acquire_payload = cred_acquire_payload;
+
+	if (GIT_DIRECTION_FETCH == t->direction)
+		service = GIT_SERVICE_UPLOADPACK_LS;
+	else if (GIT_DIRECTION_PUSH == t->direction)
+		service = GIT_SERVICE_RECEIVEPACK_LS;
+	else {
+		giterr_set(GITERR_NET, "invalid direction");
+		return -1;
+	}
+
+	if ((error = t->wrapped->action(&stream, t->wrapped, t->url, service)) < 0)
+		return error;
+
+	/* Save off the current stream (i.e. socket) that we are working with */
+	t->current_stream = stream;
+
+	gitno_buffer_setup_callback(&t->buffer, t->buffer_data, sizeof(t->buffer_data), git_smart__recv_cb, t);
+
+	/* 2 flushes for RPC; 1 for stateful */
+	if ((error = git_smart__store_refs(t, t->rpc ? 2 : 1)) < 0)
+		return error;
+
+	/* Strip the comment packet for RPC */
+	if (t->rpc) {
+		pkt = (git_pkt *)git_vector_get(&t->refs, 0);
+
+		if (!pkt || GIT_PKT_COMMENT != pkt->type) {
+			giterr_set(GITERR_NET, "invalid response");
+			return -1;
+		} else {
+			/* Remove the comment pkt from the list */
+			git_vector_remove(&t->refs, 0);
+			git__free(pkt);
+		}
+	}
+
+	/* We now have loaded the refs. */
+	t->have_refs = 1;
+
+	first = (git_pkt_ref *)git_vector_get(&t->refs, 0);
+
+	if ((error = git_vector_init(&symrefs, 1, NULL)) < 0)
+		return error;
+
+	/* Detect capabilities */
+	if (git_smart__detect_caps(first, &t->caps, &symrefs) < 0)
+		return -1;
+
+	/* If the only ref in the list is capabilities^{} with OID_ZERO, remove it */
+	if (1 == t->refs.length && !strcmp(first->head.name, "capabilities^{}") &&
+		git_oid_iszero(&first->head.oid)) {
+		git_vector_clear(&t->refs);
+		git_pkt_free((git_pkt *)first);
+	}
+
+	/* Keep a list of heads for _ls */
+	git_smart__update_heads(t, &symrefs);
+
+	free_symrefs(&symrefs);
+
+	if (t->rpc && git_smart__reset_stream(t, false) < 0)
+		return -1;
+
+	/* We're now logically connected. */
+	t->connected = 1;
+
+	return 0;
+}
+
+static int git_smart__ls(const git_remote_head ***out, size_t *size, git_transport *transport)
+{
+	transport_smart *t = (transport_smart *)transport;
+
+	if (!t->have_refs) {
+		giterr_set(GITERR_NET, "the transport has not yet loaded the refs");
+		return -1;
+	}
+
+	*out = (const git_remote_head **) t->heads.contents;
+	*size = t->heads.length;
+
+	return 0;
+}
+
+int git_smart__negotiation_step(git_transport *transport, void *data, size_t len)
+{
+	transport_smart *t = (transport_smart *)transport;
+	git_smart_subtransport_stream *stream;
+	int error;
+
+	if (t->rpc && git_smart__reset_stream(t, false) < 0)
+		return -1;
+
+	if (GIT_DIRECTION_FETCH != t->direction) {
+		giterr_set(GITERR_NET, "this operation is only valid for fetch");
+		return -1;
+	}
+
+	if ((error = t->wrapped->action(&stream, t->wrapped, t->url, GIT_SERVICE_UPLOADPACK)) < 0)
+		return error;
+
+	/* If this is a stateful implementation, the stream we get back should be the same */
+	assert(t->rpc || t->current_stream == stream);
+
+	/* Save off the current stream (i.e. socket) that we are working with */
+	t->current_stream = stream;
+
+	if ((error = stream->write(stream, (const char *)data, len)) < 0)
+		return error;
+
+	gitno_buffer_setup_callback(&t->buffer, t->buffer_data, sizeof(t->buffer_data), git_smart__recv_cb, t);
+
+	return 0;
+}
+
+int git_smart__get_push_stream(transport_smart *t, git_smart_subtransport_stream **stream)
+{
+	int error;
+
+	if (t->rpc && git_smart__reset_stream(t, false) < 0)
+		return -1;
+
+	if (GIT_DIRECTION_PUSH != t->direction) {
+		giterr_set(GITERR_NET, "this operation is only valid for push");
+		return -1;
+	}
+
+	if ((error = t->wrapped->action(stream, t->wrapped, t->url, GIT_SERVICE_RECEIVEPACK)) < 0)
+		return error;
+
+	/* If this is a stateful implementation, the stream we get back should be the same */
+	assert(t->rpc || t->current_stream == *stream);
+
+	/* Save off the current stream (i.e. socket) that we are working with */
+	t->current_stream = *stream;
+
+	gitno_buffer_setup_callback(&t->buffer, t->buffer_data, sizeof(t->buffer_data), git_smart__recv_cb, t);
+
+	return 0;
+}
+
+static void git_smart__cancel(git_transport *transport)
+{
+	transport_smart *t = (transport_smart *)transport;
+
+	git_atomic_set(&t->cancelled, 1);
+}
+
+static int git_smart__is_connected(git_transport *transport)
+{
+	transport_smart *t = (transport_smart *)transport;
+
+	return t->connected;
+}
+
+static int git_smart__read_flags(git_transport *transport, int *flags)
+{
+	transport_smart *t = (transport_smart *)transport;
+
+	*flags = t->flags;
+
+	return 0;
+}
+
+static int git_smart__close(git_transport *transport)
+{
+	transport_smart *t = (transport_smart *)transport;
+	git_vector *common = &t->common;
+	unsigned int i;
+	git_pkt *p;
+	int ret;
+	git_smart_subtransport_stream *stream;
+	const char flush[] = "0000";
+
+	/*
+	 * If we're still connected at this point and not using RPC,
+	 * we should say goodbye by sending a flush, or git-daemon
+	 * will complain that we disconnected unexpectedly.
+	 */
+	if (t->connected && !t->rpc &&
+	    !t->wrapped->action(&stream, t->wrapped, t->url, GIT_SERVICE_UPLOADPACK)) {
+		t->current_stream->write(t->current_stream, flush, 4);
+	}
+
+	ret = git_smart__reset_stream(t, true);
+
+	git_vector_foreach(common, i, p)
+		git_pkt_free(p);
+
+	git_vector_free(common);
+
+	if (t->url) {
+		git__free(t->url);
+		t->url = NULL;
+	}
+
+	t->connected = 0;
+
+	return ret;
+}
+
+static void git_smart__free(git_transport *transport)
+{
+	transport_smart *t = (transport_smart *)transport;
+	git_vector *refs = &t->refs;
+	unsigned int i;
+	git_pkt *p;
+
+	/* Make sure that the current stream is closed, if we have one. */
+	git_smart__close(transport);
+
+	/* Free the subtransport */
+	t->wrapped->free(t->wrapped);
+
+	git_vector_free(&t->heads);
+	git_vector_foreach(refs, i, p)
+		git_pkt_free(p);
+
+	git_vector_free(refs);
+	git__free((char *)t->proxy.url);
+
+	git_strarray_free(&t->custom_headers);
+
+	git__free(t);
+}
+
+static int ref_name_cmp(const void *a, const void *b)
+{
+	const git_pkt_ref *ref_a = a, *ref_b = b;
+
+	return strcmp(ref_a->head.name, ref_b->head.name);
+}
+
+int git_transport_smart_certificate_check(git_transport *transport, git_cert *cert, int valid, const char *hostname)
+{
+	transport_smart *t = (transport_smart *)transport;
+
+	return t->certificate_check_cb(cert, valid, hostname, t->message_cb_payload);
+}
+
+int git_transport_smart_credentials(git_cred **out, git_transport *transport, const char *user, int methods)
+{
+	transport_smart *t = (transport_smart *)transport;
+
+	return t->cred_acquire_cb(out, t->url, user, methods, t->cred_acquire_payload);
+}
+
+int git_transport_smart_proxy_options(git_proxy_options *out, git_transport *transport)
+{
+	transport_smart *t = (transport_smart *) transport;
+	return git_proxy_options_dup(out, &t->proxy);
+}
+
+int git_transport_smart(git_transport **out, git_remote *owner, void *param)
+{
+	transport_smart *t;
+	git_smart_subtransport_definition *definition = (git_smart_subtransport_definition *)param;
+
+	if (!param)
+		return -1;
+
+	t = git__calloc(1, sizeof(transport_smart));
+	GITERR_CHECK_ALLOC(t);
+
+	t->parent.version = GIT_TRANSPORT_VERSION;
+	t->parent.set_callbacks = git_smart__set_callbacks;
+	t->parent.set_custom_headers = git_smart__set_custom_headers;
+	t->parent.connect = git_smart__connect;
+	t->parent.close = git_smart__close;
+	t->parent.free = git_smart__free;
+	t->parent.negotiate_fetch = git_smart__negotiate_fetch;
+	t->parent.download_pack = git_smart__download_pack;
+	t->parent.push = git_smart__push;
+	t->parent.ls = git_smart__ls;
+	t->parent.is_connected = git_smart__is_connected;
+	t->parent.read_flags = git_smart__read_flags;
+	t->parent.cancel = git_smart__cancel;
+
+	t->owner = owner;
+	t->rpc = definition->rpc;
+
+	if (git_vector_init(&t->refs, 16, ref_name_cmp) < 0) {
+		git__free(t);
+		return -1;
+	}
+
+	if (git_vector_init(&t->heads, 16, ref_name_cmp) < 0) {
+		git__free(t);
+		return -1;
+	}
+
+	if (definition->callback(&t->wrapped, &t->parent, definition->param) < 0) {
+		git__free(t);
+		return -1;
+	}
+
+	*out = (git_transport *) t;
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/transports/smart.h

diff --git a/vendor/libgit2-sys/libgit2/src/transports/smart.h b/vendor/libgit2-sys/libgit2/src/transports/smart.h
new file mode 100644
index 0000000..26bd64e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transports/smart.h
@@ -0,0 +1,200 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_transports_smart_h__
+#define INCLUDE_transports_smart_h__
+
+#include "common.h"
+
+#include "git2.h"
+#include "vector.h"
+#include "netops.h"
+#include "buffer.h"
+#include "push.h"
+#include "git2/sys/transport.h"
+
+#define GIT_SIDE_BAND_DATA     1
+#define GIT_SIDE_BAND_PROGRESS 2
+#define GIT_SIDE_BAND_ERROR    3
+
+#define GIT_CAP_OFS_DELTA "ofs-delta"
+#define GIT_CAP_MULTI_ACK "multi_ack"
+#define GIT_CAP_MULTI_ACK_DETAILED "multi_ack_detailed"
+#define GIT_CAP_SIDE_BAND "side-band"
+#define GIT_CAP_SIDE_BAND_64K "side-band-64k"
+#define GIT_CAP_INCLUDE_TAG "include-tag"
+#define GIT_CAP_DELETE_REFS "delete-refs"
+#define GIT_CAP_REPORT_STATUS "report-status"
+#define GIT_CAP_THIN_PACK "thin-pack"
+#define GIT_CAP_SYMREF "symref"
+
+extern bool git_smart__ofs_delta_enabled;
+
+typedef enum {
+	GIT_PKT_CMD,
+	GIT_PKT_FLUSH,
+	GIT_PKT_REF,
+	GIT_PKT_HAVE,
+	GIT_PKT_ACK,
+	GIT_PKT_NAK,
+	GIT_PKT_PACK,
+	GIT_PKT_COMMENT,
+	GIT_PKT_ERR,
+	GIT_PKT_DATA,
+	GIT_PKT_PROGRESS,
+	GIT_PKT_OK,
+	GIT_PKT_NG,
+	GIT_PKT_UNPACK,
+} git_pkt_type;
+
+/* Used for multi_ack and multi_ack_detailed */
+enum git_ack_status {
+	GIT_ACK_NONE,
+	GIT_ACK_CONTINUE,
+	GIT_ACK_COMMON,
+	GIT_ACK_READY
+};
+
+/* This would be a flush pkt */
+typedef struct {
+	git_pkt_type type;
+} git_pkt;
+
+struct git_pkt_cmd {
+	git_pkt_type type;
+	char *cmd;
+	char *path;
+	char *host;
+};
+
+/* This is a pkt-line with some info in it */
+typedef struct {
+	git_pkt_type type;
+	git_remote_head head;
+	char *capabilities;
+} git_pkt_ref;
+
+/* Useful later */
+typedef struct {
+	git_pkt_type type;
+	git_oid oid;
+	enum git_ack_status status;
+} git_pkt_ack;
+
+typedef struct {
+	git_pkt_type type;
+	char comment[GIT_FLEX_ARRAY];
+} git_pkt_comment;
+
+typedef struct {
+	git_pkt_type type;
+	int len;
+	char data[GIT_FLEX_ARRAY];
+} git_pkt_data;
+
+typedef git_pkt_data git_pkt_progress;
+
+typedef struct {
+	git_pkt_type type;
+	int len;
+	char error[GIT_FLEX_ARRAY];
+} git_pkt_err;
+
+typedef struct {
+	git_pkt_type type;
+	char *ref;
+} git_pkt_ok;
+
+typedef struct {
+	git_pkt_type type;
+	char *ref;
+	char *msg;
+} git_pkt_ng;
+
+typedef struct {
+	git_pkt_type type;
+	int unpack_ok;
+} git_pkt_unpack;
+
+typedef struct transport_smart_caps {
+	int common:1,
+		ofs_delta:1,
+		multi_ack: 1,
+		multi_ack_detailed: 1,
+		side_band:1,
+		side_band_64k:1,
+		include_tag:1,
+		delete_refs:1,
+		report_status:1,
+		thin_pack:1;
+} transport_smart_caps;
+
+typedef int (*packetsize_cb)(size_t received, void *payload);
+
+typedef struct {
+	git_transport parent;
+	git_remote *owner;
+	char *url;
+	git_cred_acquire_cb cred_acquire_cb;
+	void *cred_acquire_payload;
+	git_proxy_options proxy;
+	int direction;
+	int flags;
+	git_transport_message_cb progress_cb;
+	git_transport_message_cb error_cb;
+	git_transport_certificate_check_cb certificate_check_cb;
+	void *message_cb_payload;
+	git_strarray custom_headers;
+	git_smart_subtransport *wrapped;
+	git_smart_subtransport_stream *current_stream;
+	transport_smart_caps caps;
+	git_vector refs;
+	git_vector heads;
+	git_vector common;
+	git_atomic cancelled;
+	packetsize_cb packetsize_cb;
+	void *packetsize_payload;
+	unsigned rpc : 1,
+		have_refs : 1,
+		connected : 1;
+	gitno_buffer buffer;
+	char buffer_data[65536];
+} transport_smart;
+
+/* smart_protocol.c */
+int git_smart__store_refs(transport_smart *t, int flushes);
+int git_smart__detect_caps(git_pkt_ref *pkt, transport_smart_caps *caps, git_vector *symrefs);
+int git_smart__push(git_transport *transport, git_push *push, const git_remote_callbacks *cbs);
+
+int git_smart__negotiate_fetch(
+	git_transport *transport,
+	git_repository *repo,
+	const git_remote_head * const *refs,
+	size_t count);
+
+int git_smart__download_pack(
+	git_transport *transport,
+	git_repository *repo,
+	git_transfer_progress *stats,
+	git_transfer_progress_cb progress_cb,
+	void *progress_payload);
+
+/* smart.c */
+int git_smart__negotiation_step(git_transport *transport, void *data, size_t len);
+int git_smart__get_push_stream(transport_smart *t, git_smart_subtransport_stream **out);
+
+int git_smart__update_heads(transport_smart *t, git_vector *symrefs);
+
+/* smart_pkt.c */
+int git_pkt_parse_line(git_pkt **head, const char *line, const char **out, size_t len);
+int git_pkt_buffer_flush(git_buf *buf);
+int git_pkt_send_flush(GIT_SOCKET s);
+int git_pkt_buffer_done(git_buf *buf);
+int git_pkt_buffer_wants(const git_remote_head * const *refs, size_t count, transport_smart_caps *caps, git_buf *buf);
+int git_pkt_buffer_have(git_oid *oid, git_buf *buf);
+void git_pkt_free(git_pkt *pkt);
+
+#endif

vendor/libgit2-sys/libgit2/src/transports/smart_pkt.c

diff --git a/vendor/libgit2-sys/libgit2/src/transports/smart_pkt.c b/vendor/libgit2-sys/libgit2/src/transports/smart_pkt.c
new file mode 100644
index 0000000..a661dfe
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transports/smart_pkt.c
@@ -0,0 +1,618 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "git2/types.h"
+#include "git2/errors.h"
+#include "git2/refs.h"
+#include "git2/revwalk.h"
+
+#include "smart.h"
+#include "util.h"
+#include "netops.h"
+#include "posix.h"
+#include "buffer.h"
+
+#include <ctype.h>
+
+#define PKT_LEN_SIZE 4
+static const char pkt_done_str[] = "0009done\n";
+static const char pkt_flush_str[] = "0000";
+static const char pkt_have_prefix[] = "0032have ";
+static const char pkt_want_prefix[] = "0032want ";
+
+static int flush_pkt(git_pkt **out)
+{
+	git_pkt *pkt;
+
+	pkt = git__malloc(sizeof(git_pkt));
+	GITERR_CHECK_ALLOC(pkt);
+
+	pkt->type = GIT_PKT_FLUSH;
+	*out = pkt;
+
+	return 0;
+}
+
+/* the rest of the line will be useful for multi_ack and multi_ack_detailed */
+static int ack_pkt(git_pkt **out, const char *line, size_t len)
+{
+	git_pkt_ack *pkt;
+	GIT_UNUSED(line);
+	GIT_UNUSED(len);
+
+	pkt = git__calloc(1, sizeof(git_pkt_ack));
+	GITERR_CHECK_ALLOC(pkt);
+
+	pkt->type = GIT_PKT_ACK;
+	line += 3;
+	len -= 3;
+
+	if (len >= GIT_OID_HEXSZ) {
+		git_oid_fromstr(&pkt->oid, line + 1);
+		line += GIT_OID_HEXSZ + 1;
+		len -= GIT_OID_HEXSZ + 1;
+	}
+
+	if (len >= 7) {
+		if (!git__prefixcmp(line + 1, "continue"))
+			pkt->status = GIT_ACK_CONTINUE;
+		if (!git__prefixcmp(line + 1, "common"))
+			pkt->status = GIT_ACK_COMMON;
+		if (!git__prefixcmp(line + 1, "ready"))
+			pkt->status = GIT_ACK_READY;
+	}
+
+	*out = (git_pkt *) pkt;
+
+	return 0;
+}
+
+static int nak_pkt(git_pkt **out)
+{
+	git_pkt *pkt;
+
+	pkt = git__malloc(sizeof(git_pkt));
+	GITERR_CHECK_ALLOC(pkt);
+
+	pkt->type = GIT_PKT_NAK;
+	*out = pkt;
+
+	return 0;
+}
+
+static int pack_pkt(git_pkt **out)
+{
+	git_pkt *pkt;
+
+	pkt = git__malloc(sizeof(git_pkt));
+	GITERR_CHECK_ALLOC(pkt);
+
+	pkt->type = GIT_PKT_PACK;
+	*out = pkt;
+
+	return 0;
+}
+
+static int comment_pkt(git_pkt **out, const char *line, size_t len)
+{
+	git_pkt_comment *pkt;
+	size_t alloclen;
+
+	GITERR_CHECK_ALLOC_ADD(&alloclen, sizeof(git_pkt_comment), len);
+	GITERR_CHECK_ALLOC_ADD(&alloclen, alloclen, 1);
+	pkt = git__malloc(alloclen);
+	GITERR_CHECK_ALLOC(pkt);
+
+	pkt->type = GIT_PKT_COMMENT;
+	memcpy(pkt->comment, line, len);
+	pkt->comment[len] = '\0';
+
+	*out = (git_pkt *) pkt;
+
+	return 0;
+}
+
+static int err_pkt(git_pkt **out, const char *line, size_t len)
+{
+	git_pkt_err *pkt;
+	size_t alloclen;
+
+	/* Remove "ERR " from the line */
+	line += 4;
+	len -= 4;
+
+	GITERR_CHECK_ALLOC_ADD(&alloclen, sizeof(git_pkt_progress), len);
+	GITERR_CHECK_ALLOC_ADD(&alloclen, alloclen, 1);
+	pkt = git__malloc(alloclen);
+	GITERR_CHECK_ALLOC(pkt);
+
+	pkt->type = GIT_PKT_ERR;
+	pkt->len = (int)len;
+	memcpy(pkt->error, line, len);
+	pkt->error[len] = '\0';
+
+	*out = (git_pkt *) pkt;
+
+	return 0;
+}
+
+static int data_pkt(git_pkt **out, const char *line, size_t len)
+{
+	git_pkt_data *pkt;
+	size_t alloclen;
+
+	line++;
+	len--;
+
+	GITERR_CHECK_ALLOC_ADD(&alloclen, sizeof(git_pkt_progress), len);
+	pkt = git__malloc(alloclen);
+	GITERR_CHECK_ALLOC(pkt);
+
+	pkt->type = GIT_PKT_DATA;
+	pkt->len = (int) len;
+	memcpy(pkt->data, line, len);
+
+	*out = (git_pkt *) pkt;
+
+	return 0;
+}
+
+static int sideband_progress_pkt(git_pkt **out, const char *line, size_t len)
+{
+	git_pkt_progress *pkt;
+	size_t alloclen;
+
+	line++;
+	len--;
+
+	GITERR_CHECK_ALLOC_ADD(&alloclen, sizeof(git_pkt_progress), len);
+	pkt = git__malloc(alloclen);
+	GITERR_CHECK_ALLOC(pkt);
+
+	pkt->type = GIT_PKT_PROGRESS;
+	pkt->len = (int) len;
+	memcpy(pkt->data, line, len);
+
+	*out = (git_pkt *) pkt;
+
+	return 0;
+}
+
+static int sideband_error_pkt(git_pkt **out, const char *line, size_t len)
+{
+	git_pkt_err *pkt;
+	size_t alloc_len;
+
+	line++;
+	len--;
+
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, sizeof(git_pkt_err), len);
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, 1);
+	pkt = git__malloc(alloc_len);
+	GITERR_CHECK_ALLOC(pkt);
+
+	pkt->type = GIT_PKT_ERR;
+	pkt->len = (int)len;
+	memcpy(pkt->error, line, len);
+	pkt->error[len] = '\0';
+
+	*out = (git_pkt *)pkt;
+
+	return 0;
+}
+
+/*
+ * Parse an other-ref line.
+ */
+static int ref_pkt(git_pkt **out, const char *line, size_t len)
+{
+	int error;
+	git_pkt_ref *pkt;
+	size_t alloclen;
+
+	pkt = git__malloc(sizeof(git_pkt_ref));
+	GITERR_CHECK_ALLOC(pkt);
+
+	memset(pkt, 0x0, sizeof(git_pkt_ref));
+	pkt->type = GIT_PKT_REF;
+	if ((error = git_oid_fromstr(&pkt->head.oid, line)) < 0)
+		goto error_out;
+
+	/* Check for a bit of consistency */
+	if (line[GIT_OID_HEXSZ] != ' ') {
+		giterr_set(GITERR_NET, "error parsing pkt-line");
+		error = -1;
+		goto error_out;
+	}
+
+	/* Jump from the name */
+	line += GIT_OID_HEXSZ + 1;
+	len -= (GIT_OID_HEXSZ + 1);
+
+	if (line[len - 1] == '\n')
+		--len;
+
+	GITERR_CHECK_ALLOC_ADD(&alloclen, len, 1);
+	pkt->head.name = git__malloc(alloclen);
+	GITERR_CHECK_ALLOC(pkt->head.name);
+
+	memcpy(pkt->head.name, line, len);
+	pkt->head.name[len] = '\0';
+
+	if (strlen(pkt->head.name) < len) {
+		pkt->capabilities = strchr(pkt->head.name, '\0') + 1;
+	}
+
+	*out = (git_pkt *)pkt;
+	return 0;
+
+error_out:
+	git__free(pkt);
+	return error;
+}
+
+static int ok_pkt(git_pkt **out, const char *line, size_t len)
+{
+	git_pkt_ok *pkt;
+	const char *ptr;
+	size_t alloc_len;
+
+	pkt = git__malloc(sizeof(*pkt));
+	GITERR_CHECK_ALLOC(pkt);
+
+	pkt->type = GIT_PKT_OK;
+
+	line += 3; /* skip "ok " */
+	if (!(ptr = strchr(line, '\n'))) {
+		giterr_set(GITERR_NET, "invalid packet line");
+		git__free(pkt);
+		return -1;
+	}
+	len = ptr - line;
+
+	GITERR_CHECK_ALLOC_ADD(&alloc_len, len, 1);
+	pkt->ref = git__malloc(alloc_len);
+	GITERR_CHECK_ALLOC(pkt->ref);
+
+	memcpy(pkt->ref, line, len);
+	pkt->ref[len] = '\0';
+
+	*out = (git_pkt *)pkt;
+	return 0;
+}
+
+static int ng_pkt(git_pkt **out, const char *line, size_t len)
+{
+	git_pkt_ng *pkt;
+	const char *ptr;
+	size_t alloclen;
+
+	pkt = git__malloc(sizeof(*pkt));
+	GITERR_CHECK_ALLOC(pkt);
+
+	pkt->ref = NULL;
+	pkt->type = GIT_PKT_NG;
+
+	line += 3; /* skip "ng " */
+	if (!(ptr = strchr(line, ' ')))
+		goto out_err;
+	len = ptr - line;
+
+	GITERR_CHECK_ALLOC_ADD(&alloclen, len, 1);
+	pkt->ref = git__malloc(alloclen);
+	GITERR_CHECK_ALLOC(pkt->ref);
+
+	memcpy(pkt->ref, line, len);
+	pkt->ref[len] = '\0';
+
+	line = ptr + 1;
+	if (!(ptr = strchr(line, '\n')))
+		goto out_err;
+	len = ptr - line;
+
+	GITERR_CHECK_ALLOC_ADD(&alloclen, len, 1);
+	pkt->msg = git__malloc(alloclen);
+	GITERR_CHECK_ALLOC(pkt->msg);
+
+	memcpy(pkt->msg, line, len);
+	pkt->msg[len] = '\0';
+
+	*out = (git_pkt *)pkt;
+	return 0;
+
+out_err:
+	giterr_set(GITERR_NET, "invalid packet line");
+	git__free(pkt->ref);
+	git__free(pkt);
+	return -1;
+}
+
+static int unpack_pkt(git_pkt **out, const char *line, size_t len)
+{
+	git_pkt_unpack *pkt;
+
+	GIT_UNUSED(len);
+
+	pkt = git__malloc(sizeof(*pkt));
+	GITERR_CHECK_ALLOC(pkt);
+
+	pkt->type = GIT_PKT_UNPACK;
+	if (!git__prefixcmp(line, "unpack ok"))
+		pkt->unpack_ok = 1;
+	else
+		pkt->unpack_ok = 0;
+
+	*out = (git_pkt *)pkt;
+	return 0;
+}
+
+static int32_t parse_len(const char *line)
+{
+	char num[PKT_LEN_SIZE + 1];
+	int i, k, error;
+	int32_t len;
+	const char *num_end;
+
+	memcpy(num, line, PKT_LEN_SIZE);
+	num[PKT_LEN_SIZE] = '\0';
+
+	for (i = 0; i < PKT_LEN_SIZE; ++i) {
+		if (!isxdigit(num[i])) {
+			/* Make sure there are no special characters before passing to error message */
+			for (k = 0; k < PKT_LEN_SIZE; ++k) {
+				if(!isprint(num[k])) {
+					num[k] = '.';
+				}
+			}
+			
+			giterr_set(GITERR_NET, "invalid hex digit in length: '%s'", num);
+			return -1;
+		}
+	}
+
+	if ((error = git__strtol32(&len, num, &num_end, 16)) < 0)
+		return error;
+
+	return len;
+}
+
+/*
+ * As per the documentation, the syntax is:
+ *
+ * pkt-line	= data-pkt / flush-pkt
+ * data-pkt	= pkt-len pkt-payload
+ * pkt-len		= 4*(HEXDIG)
+ * pkt-payload = (pkt-len -4)*(OCTET)
+ * flush-pkt	= "0000"
+ *
+ * Which means that the first four bytes are the length of the line,
+ * in ASCII hexadecimal (including itself)
+ */
+
+int git_pkt_parse_line(
+	git_pkt **head, const char *line, const char **out, size_t bufflen)
+{
+	int ret;
+	int32_t len;
+
+	/* Not even enough for the length */
+	if (bufflen > 0 && bufflen < PKT_LEN_SIZE)
+		return GIT_EBUFS;
+
+	len = parse_len(line);
+	if (len < 0) {
+		/*
+		 * If we fail to parse the length, it might be because the
+		 * server is trying to send us the packfile already.
+		 */
+		if (bufflen >= 4 && !git__prefixcmp(line, "PACK")) {
+			giterr_clear();
+			*out = line;
+			return pack_pkt(head);
+		}
+
+		return (int)len;
+	}
+
+	/*
+	 * If we were given a buffer length, then make sure there is
+	 * enough in the buffer to satisfy this line
+	 */
+	if (bufflen > 0 && bufflen < (size_t)len)
+		return GIT_EBUFS;
+
+	/*
+	 * The length has to be exactly 0 in case of a flush
+	 * packet or greater than PKT_LEN_SIZE, as the decoded
+	 * length includes its own encoded length of four bytes.
+	 */
+	if (len != 0 && len < PKT_LEN_SIZE)
+		return GIT_ERROR;
+
+	line += PKT_LEN_SIZE;
+	/*
+	 * The Git protocol does not specify empty lines as part
+	 * of the protocol. Not knowing what to do with an empty
+	 * line, we should return an error upon hitting one.
+	 */
+	if (len == PKT_LEN_SIZE) {
+		giterr_set_str(GITERR_NET, "Invalid empty packet");
+		return GIT_ERROR;
+	}
+
+	if (len == 0) { /* Flush pkt */
+		*out = line;
+		return flush_pkt(head);
+	}
+
+	len -= PKT_LEN_SIZE; /* the encoded length includes its own size */
+
+	if (*line == GIT_SIDE_BAND_DATA)
+		ret = data_pkt(head, line, len);
+	else if (*line == GIT_SIDE_BAND_PROGRESS)
+		ret = sideband_progress_pkt(head, line, len);
+	else if (*line == GIT_SIDE_BAND_ERROR)
+		ret = sideband_error_pkt(head, line, len);
+	else if (!git__prefixcmp(line, "ACK"))
+		ret = ack_pkt(head, line, len);
+	else if (!git__prefixcmp(line, "NAK"))
+		ret = nak_pkt(head);
+	else if (!git__prefixcmp(line, "ERR "))
+		ret = err_pkt(head, line, len);
+	else if (*line == '#')
+		ret = comment_pkt(head, line, len);
+	else if (!git__prefixcmp(line, "ok"))
+		ret = ok_pkt(head, line, len);
+	else if (!git__prefixcmp(line, "ng"))
+		ret = ng_pkt(head, line, len);
+	else if (!git__prefixcmp(line, "unpack"))
+		ret = unpack_pkt(head, line, len);
+	else
+		ret = ref_pkt(head, line, len);
+
+	*out = line + len;
+
+	return ret;
+}
+
+void git_pkt_free(git_pkt *pkt)
+{
+	if (pkt->type == GIT_PKT_REF) {
+		git_pkt_ref *p = (git_pkt_ref *) pkt;
+		git__free(p->head.name);
+		git__free(p->head.symref_target);
+	}
+
+	if (pkt->type == GIT_PKT_OK) {
+		git_pkt_ok *p = (git_pkt_ok *) pkt;
+		git__free(p->ref);
+	}
+
+	if (pkt->type == GIT_PKT_NG) {
+		git_pkt_ng *p = (git_pkt_ng *) pkt;
+		git__free(p->ref);
+		git__free(p->msg);
+	}
+
+	git__free(pkt);
+}
+
+int git_pkt_buffer_flush(git_buf *buf)
+{
+	return git_buf_put(buf, pkt_flush_str, strlen(pkt_flush_str));
+}
+
+static int buffer_want_with_caps(const git_remote_head *head, transport_smart_caps *caps, git_buf *buf)
+{
+	git_buf str = GIT_BUF_INIT;
+	char oid[GIT_OID_HEXSZ +1] = {0};
+	size_t len;
+
+	/* Prefer multi_ack_detailed */
+	if (caps->multi_ack_detailed)
+		git_buf_puts(&str, GIT_CAP_MULTI_ACK_DETAILED " ");
+	else if (caps->multi_ack)
+		git_buf_puts(&str, GIT_CAP_MULTI_ACK " ");
+
+	/* Prefer side-band-64k if the server supports both */
+	if (caps->side_band_64k)
+		git_buf_printf(&str, "%s ", GIT_CAP_SIDE_BAND_64K);
+	else if (caps->side_band)
+		git_buf_printf(&str, "%s ", GIT_CAP_SIDE_BAND);
+
+	if (caps->include_tag)
+		git_buf_puts(&str, GIT_CAP_INCLUDE_TAG " ");
+
+	if (caps->thin_pack)
+		git_buf_puts(&str, GIT_CAP_THIN_PACK " ");
+
+	if (caps->ofs_delta)
+		git_buf_puts(&str, GIT_CAP_OFS_DELTA " ");
+
+	if (git_buf_oom(&str))
+		return -1;
+
+	len = strlen("XXXXwant ") + GIT_OID_HEXSZ + 1 /* NUL */ +
+		 git_buf_len(&str) + 1 /* LF */;
+
+	if (len > 0xffff) {
+		giterr_set(GITERR_NET,
+			"tried to produce packet with invalid length %" PRIuZ, len);
+		return -1;
+	}
+
+	git_buf_grow_by(buf, len);
+	git_oid_fmt(oid, &head->oid);
+	git_buf_printf(buf,
+		"%04xwant %s %s\n", (unsigned int)len, oid, git_buf_cstr(&str));
+	git_buf_free(&str);
+
+	GITERR_CHECK_ALLOC_BUF(buf);
+
+	return 0;
+}
+
+/*
+ * All "want" packets have the same length and format, so what we do
+ * is overwrite the OID each time.
+ */
+
+int git_pkt_buffer_wants(
+	const git_remote_head * const *refs,
+	size_t count,
+	transport_smart_caps *caps,
+	git_buf *buf)
+{
+	size_t i = 0;
+	const git_remote_head *head;
+
+	if (caps->common) {
+		for (; i < count; ++i) {
+			head = refs[i];
+			if (!head->local)
+				break;
+		}
+
+		if (buffer_want_with_caps(refs[i], caps, buf) < 0)
+			return -1;
+
+		i++;
+	}
+
+	for (; i < count; ++i) {
+		char oid[GIT_OID_HEXSZ];
+
+		head = refs[i];
+		if (head->local)
+			continue;
+
+		git_oid_fmt(oid, &head->oid);
+		git_buf_put(buf, pkt_want_prefix, strlen(pkt_want_prefix));
+		git_buf_put(buf, oid, GIT_OID_HEXSZ);
+		git_buf_putc(buf, '\n');
+		if (git_buf_oom(buf))
+			return -1;
+	}
+
+	return git_pkt_buffer_flush(buf);
+}
+
+int git_pkt_buffer_have(git_oid *oid, git_buf *buf)
+{
+	char oidhex[GIT_OID_HEXSZ + 1];
+
+	memset(oidhex, 0x0, sizeof(oidhex));
+	git_oid_fmt(oidhex, oid);
+	return git_buf_printf(buf, "%s%s\n", pkt_have_prefix, oidhex);
+}
+
+int git_pkt_buffer_done(git_buf *buf)
+{
+	return git_buf_puts(buf, pkt_done_str);
+}

vendor/libgit2-sys/libgit2/src/transports/smart_protocol.c

diff --git a/vendor/libgit2-sys/libgit2/src/transports/smart_protocol.c b/vendor/libgit2-sys/libgit2/src/transports/smart_protocol.c
new file mode 100644
index 0000000..ab52e04
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transports/smart_protocol.c
@@ -0,0 +1,1090 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "git2.h"
+#include "git2/odb_backend.h"
+
+#include "smart.h"
+#include "refs.h"
+#include "repository.h"
+#include "push.h"
+#include "pack-objects.h"
+#include "remote.h"
+#include "util.h"
+
+#define NETWORK_XFER_THRESHOLD (100*1024)
+/* The minimal interval between progress updates (in seconds). */
+#define MIN_PROGRESS_UPDATE_INTERVAL 0.5
+
+bool git_smart__ofs_delta_enabled = true;
+
+int git_smart__store_refs(transport_smart *t, int flushes)
+{
+	gitno_buffer *buf = &t->buffer;
+	git_vector *refs = &t->refs;
+	int error, flush = 0, recvd;
+	const char *line_end = NULL;
+	git_pkt *pkt = NULL;
+	size_t i;
+
+	/* Clear existing refs in case git_remote_connect() is called again
+	 * after git_remote_disconnect().
+	 */
+	git_vector_foreach(refs, i, pkt) {
+		git_pkt_free(pkt);
+	}
+	git_vector_clear(refs);
+	pkt = NULL;
+
+	do {
+		if (buf->offset > 0)
+			error = git_pkt_parse_line(&pkt, buf->data, &line_end, buf->offset);
+		else
+			error = GIT_EBUFS;
+
+		if (error < 0 && error != GIT_EBUFS)
+			return error;
+
+		if (error == GIT_EBUFS) {
+			if ((recvd = gitno_recv(buf)) < 0)
+				return recvd;
+
+			if (recvd == 0) {
+				giterr_set(GITERR_NET, "early EOF");
+				return GIT_EEOF;
+			}
+
+			continue;
+		}
+
+		gitno_consume(buf, line_end);
+		if (pkt->type == GIT_PKT_ERR) {
+			giterr_set(GITERR_NET, "remote error: %s", ((git_pkt_err *)pkt)->error);
+			git__free(pkt);
+			return -1;
+		}
+
+		if (pkt->type != GIT_PKT_FLUSH && git_vector_insert(refs, pkt) < 0)
+			return -1;
+
+		if (pkt->type == GIT_PKT_FLUSH) {
+			flush++;
+			git_pkt_free(pkt);
+		}
+	} while (flush < flushes);
+
+	return flush;
+}
+
+static int append_symref(const char **out, git_vector *symrefs, const char *ptr)
+{
+	int error;
+	const char *end;
+	git_buf buf = GIT_BUF_INIT;
+	git_refspec *mapping = NULL;
+
+	ptr += strlen(GIT_CAP_SYMREF);
+	if (*ptr != '=')
+		goto on_invalid;
+
+	ptr++;
+	if (!(end = strchr(ptr, ' ')) &&
+	    !(end = strchr(ptr, '\0')))
+		goto on_invalid;
+
+	if ((error = git_buf_put(&buf, ptr, end - ptr)) < 0)
+		return error;
+
+	/* symref mapping has refspec format */
+	mapping = git__calloc(1, sizeof(git_refspec));
+	GITERR_CHECK_ALLOC(mapping);
+
+	error = git_refspec__parse(mapping, git_buf_cstr(&buf), true);
+	git_buf_free(&buf);
+
+	/* if the error isn't OOM, then it's a parse error; let's use a nicer message */
+	if (error < 0) {
+		if (giterr_last()->klass != GITERR_NOMEMORY)
+			goto on_invalid;
+
+		git__free(mapping);
+		return error;
+	}
+
+	if ((error = git_vector_insert(symrefs, mapping)) < 0)
+		return error;
+
+	*out = end;
+	return 0;
+
+on_invalid:
+	giterr_set(GITERR_NET, "remote sent invalid symref");
+	git_refspec__free(mapping);
+	git__free(mapping);
+	return -1;
+}
+
+int git_smart__detect_caps(git_pkt_ref *pkt, transport_smart_caps *caps, git_vector *symrefs)
+{
+	const char *ptr;
+
+	/* No refs or capabilites, odd but not a problem */
+	if (pkt == NULL || pkt->capabilities == NULL)
+		return 0;
+
+	ptr = pkt->capabilities;
+	while (ptr != NULL && *ptr != '\0') {
+		if (*ptr == ' ')
+			ptr++;
+
+		if (git_smart__ofs_delta_enabled && !git__prefixcmp(ptr, GIT_CAP_OFS_DELTA)) {
+			caps->common = caps->ofs_delta = 1;
+			ptr += strlen(GIT_CAP_OFS_DELTA);
+			continue;
+		}
+
+		/* Keep multi_ack_detailed before multi_ack */
+		if (!git__prefixcmp(ptr, GIT_CAP_MULTI_ACK_DETAILED)) {
+			caps->common = caps->multi_ack_detailed = 1;
+			ptr += strlen(GIT_CAP_MULTI_ACK_DETAILED);
+			continue;
+		}
+
+		if (!git__prefixcmp(ptr, GIT_CAP_MULTI_ACK)) {
+			caps->common = caps->multi_ack = 1;
+			ptr += strlen(GIT_CAP_MULTI_ACK);
+			continue;
+		}
+
+		if (!git__prefixcmp(ptr, GIT_CAP_INCLUDE_TAG)) {
+			caps->common = caps->include_tag = 1;
+			ptr += strlen(GIT_CAP_INCLUDE_TAG);
+			continue;
+		}
+
+		/* Keep side-band check after side-band-64k */
+		if (!git__prefixcmp(ptr, GIT_CAP_SIDE_BAND_64K)) {
+			caps->common = caps->side_band_64k = 1;
+			ptr += strlen(GIT_CAP_SIDE_BAND_64K);
+			continue;
+		}
+
+		if (!git__prefixcmp(ptr, GIT_CAP_SIDE_BAND)) {
+			caps->common = caps->side_band = 1;
+			ptr += strlen(GIT_CAP_SIDE_BAND);
+			continue;
+		}
+
+		if (!git__prefixcmp(ptr, GIT_CAP_DELETE_REFS)) {
+			caps->common = caps->delete_refs = 1;
+			ptr += strlen(GIT_CAP_DELETE_REFS);
+			continue;
+		}
+
+		if (!git__prefixcmp(ptr, GIT_CAP_THIN_PACK)) {
+			caps->common = caps->thin_pack = 1;
+			ptr += strlen(GIT_CAP_THIN_PACK);
+			continue;
+		}
+
+		if (!git__prefixcmp(ptr, GIT_CAP_SYMREF)) {
+			int error;
+
+			if ((error = append_symref(&ptr, symrefs, ptr)) < 0)
+				return error;
+
+			continue;
+		}
+
+		/* We don't know this capability, so skip it */
+		ptr = strchr(ptr, ' ');
+	}
+
+	return 0;
+}
+
+static int recv_pkt(git_pkt **out_pkt, git_pkt_type *out_type, gitno_buffer *buf)
+{
+	const char *ptr = buf->data, *line_end = ptr;
+	git_pkt *pkt = NULL;
+	int error = 0, ret;
+
+	do {
+		if (buf->offset > 0)
+			error = git_pkt_parse_line(&pkt, ptr, &line_end, buf->offset);
+		else
+			error = GIT_EBUFS;
+
+		if (error == 0)
+			break; /* return the pkt */
+
+		if (error < 0 && error != GIT_EBUFS)
+			return error;
+
+		if ((ret = gitno_recv(buf)) < 0) {
+			return ret;
+		} else if (ret == 0) {
+			giterr_set(GITERR_NET, "early EOF");
+			return GIT_EEOF;
+		}
+	} while (error);
+
+	gitno_consume(buf, line_end);
+	if (out_type != NULL)
+		*out_type = pkt->type;
+	if (out_pkt != NULL)
+		*out_pkt = pkt;
+	else
+		git__free(pkt);
+
+	return error;
+}
+
+static int store_common(transport_smart *t)
+{
+	git_pkt *pkt = NULL;
+	gitno_buffer *buf = &t->buffer;
+	int error;
+
+	do {
+		if ((error = recv_pkt(&pkt, NULL, buf)) < 0)
+			return error;
+
+		if (pkt->type != GIT_PKT_ACK) {
+			git__free(pkt);
+			return 0;
+		}
+
+		if (git_vector_insert(&t->common, pkt) < 0) {
+			git__free(pkt);
+			return -1;
+		}
+	} while (1);
+
+	return 0;
+}
+
+static int fetch_setup_walk(git_revwalk **out, git_repository *repo)
+{
+	git_revwalk *walk = NULL;
+	git_strarray refs;
+	unsigned int i;
+	git_reference *ref = NULL;
+	int error;
+
+	if ((error = git_reference_list(&refs, repo)) < 0)
+		return error;
+
+	if ((error = git_revwalk_new(&walk, repo)) < 0)
+		return error;
+
+	git_revwalk_sorting(walk, GIT_SORT_TIME);
+
+	for (i = 0; i < refs.count; ++i) {
+		git_reference_free(ref);
+		ref = NULL;
+
+		/* No tags */
+		if (!git__prefixcmp(refs.strings[i], GIT_REFS_TAGS_DIR))
+			continue;
+
+		if ((error = git_reference_lookup(&ref, repo, refs.strings[i])) < 0)
+			goto on_error;
+
+		if (git_reference_type(ref) == GIT_REF_SYMBOLIC)
+			continue;
+
+		if ((error = git_revwalk_push(walk, git_reference_target(ref))) < 0)
+			goto on_error;
+	}
+
+	*out = walk;
+
+on_error:
+	if (error)
+		git_revwalk_free(walk);
+	git_reference_free(ref);
+	git_strarray_free(&refs);
+	return error;
+}
+
+static int wait_while_ack(gitno_buffer *buf)
+{
+	int error;
+	git_pkt_ack *pkt = NULL;
+
+	while (1) {
+		git__free(pkt);
+
+		if ((error = recv_pkt((git_pkt **)&pkt, NULL, buf)) < 0)
+			return error;
+
+		if (pkt->type == GIT_PKT_NAK)
+			break;
+
+		if (pkt->type == GIT_PKT_ACK &&
+		    (pkt->status != GIT_ACK_CONTINUE &&
+		     pkt->status != GIT_ACK_COMMON &&
+		     pkt->status != GIT_ACK_READY)) {
+			git__free(pkt);
+			return 0;
+		}
+	}
+
+	git__free(pkt);
+	return 0;
+}
+
+int git_smart__negotiate_fetch(git_transport *transport, git_repository *repo, const git_remote_head * const *wants, size_t count)
+{
+	transport_smart *t = (transport_smart *)transport;
+	gitno_buffer *buf = &t->buffer;
+	git_buf data = GIT_BUF_INIT;
+	git_revwalk *walk = NULL;
+	int error = -1;
+	git_pkt_type pkt_type;
+	unsigned int i;
+	git_oid oid;
+
+	if ((error = git_pkt_buffer_wants(wants, count, &t->caps, &data)) < 0)
+		return error;
+
+	if ((error = fetch_setup_walk(&walk, repo)) < 0)
+		goto on_error;
+
+	/*
+	 * Our support for ACK extensions is simply to parse them. On
+	 * the first ACK we will accept that as enough common
+	 * objects. We give up if we haven't found an answer in the
+	 * first 256 we send.
+	 */
+	i = 0;
+	while (i < 256) {
+		error = git_revwalk_next(&oid, walk);
+
+		if (error < 0) {
+			if (GIT_ITEROVER == error)
+				break;
+
+			goto on_error;
+		}
+
+		git_pkt_buffer_have(&oid, &data);
+		i++;
+		if (i % 20 == 0) {
+			if (t->cancelled.val) {
+				giterr_set(GITERR_NET, "The fetch was cancelled by the user");
+				error = GIT_EUSER;
+				goto on_error;
+			}
+
+			git_pkt_buffer_flush(&data);
+			if (git_buf_oom(&data)) {
+				error = -1;
+				goto on_error;
+			}
+
+			if ((error = git_smart__negotiation_step(&t->parent, data.ptr, data.size)) < 0)
+				goto on_error;
+
+			git_buf_clear(&data);
+			if (t->caps.multi_ack || t->caps.multi_ack_detailed) {
+				if ((error = store_common(t)) < 0)
+					goto on_error;
+			} else {
+				if ((error = recv_pkt(NULL, &pkt_type, buf)) < 0)
+					goto on_error;
+
+				if (pkt_type == GIT_PKT_ACK) {
+					break;
+				} else if (pkt_type == GIT_PKT_NAK) {
+					continue;
+				} else {
+					giterr_set(GITERR_NET, "Unexpected pkt type");
+					error = -1;
+					goto on_error;
+				}
+			}
+		}
+
+		if (t->common.length > 0)
+			break;
+
+		if (i % 20 == 0 && t->rpc) {
+			git_pkt_ack *pkt;
+			unsigned int j;
+
+			if ((error = git_pkt_buffer_wants(wants, count, &t->caps, &data)) < 0)
+				goto on_error;
+
+			git_vector_foreach(&t->common, j, pkt) {
+				if ((error = git_pkt_buffer_have(&pkt->oid, &data)) < 0)
+					goto on_error;
+			}
+
+			if (git_buf_oom(&data)) {
+				error = -1;
+				goto on_error;
+			}
+		}
+	}
+
+	/* Tell the other end that we're done negotiating */
+	if (t->rpc && t->common.length > 0) {
+		git_pkt_ack *pkt;
+		unsigned int j;
+
+		if ((error = git_pkt_buffer_wants(wants, count, &t->caps, &data)) < 0)
+			goto on_error;
+
+		git_vector_foreach(&t->common, j, pkt) {
+			if ((error = git_pkt_buffer_have(&pkt->oid, &data)) < 0)
+				goto on_error;
+		}
+
+		if (git_buf_oom(&data)) {
+			error = -1;
+			goto on_error;
+		}
+	}
+
+	if ((error = git_pkt_buffer_done(&data)) < 0)
+		goto on_error;
+
+	if (t->cancelled.val) {
+		giterr_set(GITERR_NET, "The fetch was cancelled by the user");
+		error = GIT_EUSER;
+		goto on_error;
+	}
+	if ((error = git_smart__negotiation_step(&t->parent, data.ptr, data.size)) < 0)
+		goto on_error;
+
+	git_buf_free(&data);
+	git_revwalk_free(walk);
+
+	/* Now let's eat up whatever the server gives us */
+	if (!t->caps.multi_ack && !t->caps.multi_ack_detailed) {
+		if ((error = recv_pkt(NULL, &pkt_type, buf)) < 0)
+			return error;
+
+		if (pkt_type != GIT_PKT_ACK && pkt_type != GIT_PKT_NAK) {
+			giterr_set(GITERR_NET, "Unexpected pkt type");
+			return -1;
+		}
+	} else {
+		error = wait_while_ack(buf);
+	}
+
+	return error;
+
+on_error:
+	git_revwalk_free(walk);
+	git_buf_free(&data);
+	return error;
+}
+
+static int no_sideband(transport_smart *t, struct git_odb_writepack *writepack, gitno_buffer *buf, git_transfer_progress *stats)
+{
+	int recvd;
+
+	do {
+		if (t->cancelled.val) {
+			giterr_set(GITERR_NET, "The fetch was cancelled by the user");
+			return GIT_EUSER;
+		}
+
+		if (writepack->append(writepack, buf->data, buf->offset, stats) < 0)
+			return -1;
+
+		gitno_consume_n(buf, buf->offset);
+
+		if ((recvd = gitno_recv(buf)) < 0)
+			return recvd;
+	} while(recvd > 0);
+
+	if (writepack->commit(writepack, stats) < 0)
+		return -1;
+
+	return 0;
+}
+
+struct network_packetsize_payload
+{
+	git_transfer_progress_cb callback;
+	void *payload;
+	git_transfer_progress *stats;
+	size_t last_fired_bytes;
+};
+
+static int network_packetsize(size_t received, void *payload)
+{
+	struct network_packetsize_payload *npp = (struct network_packetsize_payload*)payload;
+
+	/* Accumulate bytes */
+	npp->stats->received_bytes += received;
+
+	/* Fire notification if the threshold is reached */
+	if ((npp->stats->received_bytes - npp->last_fired_bytes) > NETWORK_XFER_THRESHOLD) {
+		npp->last_fired_bytes = npp->stats->received_bytes;
+
+		if (npp->callback(npp->stats, npp->payload))
+			return GIT_EUSER;
+	}
+
+	return 0;
+}
+
+int git_smart__download_pack(
+	git_transport *transport,
+	git_repository *repo,
+	git_transfer_progress *stats,
+	git_transfer_progress_cb transfer_progress_cb,
+	void *progress_payload)
+{
+	transport_smart *t = (transport_smart *)transport;
+	gitno_buffer *buf = &t->buffer;
+	git_odb *odb;
+	struct git_odb_writepack *writepack = NULL;
+	int error = 0;
+	struct network_packetsize_payload npp = {0};
+
+	memset(stats, 0, sizeof(git_transfer_progress));
+
+	if (transfer_progress_cb) {
+		npp.callback = transfer_progress_cb;
+		npp.payload = progress_payload;
+		npp.stats = stats;
+		t->packetsize_cb = &network_packetsize;
+		t->packetsize_payload = &npp;
+
+		/* We might have something in the buffer already from negotiate_fetch */
+		if (t->buffer.offset > 0 && !t->cancelled.val)
+			if (t->packetsize_cb(t->buffer.offset, t->packetsize_payload))
+				git_atomic_set(&t->cancelled, 1);
+	}
+
+	if ((error = git_repository_odb__weakptr(&odb, repo)) < 0 ||
+		((error = git_odb_write_pack(&writepack, odb, transfer_progress_cb, progress_payload)) != 0))
+		goto done;
+
+	/*
+	 * If the remote doesn't support the side-band, we can feed
+	 * the data directly to the pack writer. Otherwise, we need to
+	 * check which one belongs there.
+	 */
+	if (!t->caps.side_band && !t->caps.side_band_64k) {
+		error = no_sideband(t, writepack, buf, stats);
+		goto done;
+	}
+
+	do {
+		git_pkt *pkt = NULL;
+
+		/* Check cancellation before network call */
+		if (t->cancelled.val) {
+			giterr_clear();
+			error = GIT_EUSER;
+			goto done;
+		}
+
+		if ((error = recv_pkt(&pkt, NULL, buf)) >= 0) {
+			/* Check cancellation after network call */
+			if (t->cancelled.val) {
+				giterr_clear();
+				error = GIT_EUSER;
+			} else if (pkt->type == GIT_PKT_PROGRESS) {
+				if (t->progress_cb) {
+					git_pkt_progress *p = (git_pkt_progress *) pkt;
+					error = t->progress_cb(p->data, p->len, t->message_cb_payload);
+				}
+			} else if (pkt->type == GIT_PKT_DATA) {
+				git_pkt_data *p = (git_pkt_data *) pkt;
+
+				if (p->len)
+					error = writepack->append(writepack, p->data, p->len, stats);
+			} else if (pkt->type == GIT_PKT_FLUSH) {
+				/* A flush indicates the end of the packfile */
+				git__free(pkt);
+				break;
+			}
+		}
+
+		git__free(pkt);
+		if (error < 0)
+			goto done;
+
+	} while (1);
+
+	/*
+	 * Trailing execution of transfer_progress_cb, if necessary...
+	 * Only the callback through the npp datastructure currently
+	 * updates the last_fired_bytes value. It is possible that
+	 * progress has already been reported with the correct
+	 * "received_bytes" value, but until (if?) this is unified
+	 * then we will report progress again to be sure that the
+	 * correct last received_bytes value is reported.
+	 */
+	if (npp.callback && npp.stats->received_bytes > npp.last_fired_bytes) {
+		error = npp.callback(npp.stats, npp.payload);
+		if (error != 0)
+			goto done;
+	}
+
+	error = writepack->commit(writepack, stats);
+
+done:
+	if (writepack)
+		writepack->free(writepack);
+	if (transfer_progress_cb) {
+		t->packetsize_cb = NULL;
+		t->packetsize_payload = NULL;
+	}
+
+	return error;
+}
+
+static int gen_pktline(git_buf *buf, git_push *push)
+{
+	push_spec *spec;
+	size_t i, len;
+	char old_id[GIT_OID_HEXSZ+1], new_id[GIT_OID_HEXSZ+1];
+
+	old_id[GIT_OID_HEXSZ] = '\0'; new_id[GIT_OID_HEXSZ] = '\0';
+
+	git_vector_foreach(&push->specs, i, spec) {
+		len = 2*GIT_OID_HEXSZ + 7 + strlen(spec->refspec.dst);
+
+		if (i == 0) {
+			++len; /* '\0' */
+			if (push->report_status)
+				len += strlen(GIT_CAP_REPORT_STATUS) + 1;
+			len += strlen(GIT_CAP_SIDE_BAND_64K) + 1;
+		}
+
+		git_oid_fmt(old_id, &spec->roid);
+		git_oid_fmt(new_id, &spec->loid);
+
+		git_buf_printf(buf, "%04"PRIxZ"%s %s %s", len, old_id, new_id, spec->refspec.dst);
+
+		if (i == 0) {
+			git_buf_putc(buf, '\0');
+			/* Core git always starts their capabilities string with a space */
+			if (push->report_status) {
+				git_buf_putc(buf, ' ');
+				git_buf_printf(buf, GIT_CAP_REPORT_STATUS);
+			}
+			git_buf_putc(buf, ' ');
+			git_buf_printf(buf, GIT_CAP_SIDE_BAND_64K);
+		}
+
+		git_buf_putc(buf, '\n');
+	}
+
+	git_buf_puts(buf, "0000");
+	return git_buf_oom(buf) ? -1 : 0;
+}
+
+static int add_push_report_pkt(git_push *push, git_pkt *pkt)
+{
+	push_status *status;
+
+	switch (pkt->type) {
+		case GIT_PKT_OK:
+			status = git__calloc(1, sizeof(push_status));
+			GITERR_CHECK_ALLOC(status);
+			status->msg = NULL;
+			status->ref = git__strdup(((git_pkt_ok *)pkt)->ref);
+			if (!status->ref ||
+				git_vector_insert(&push->status, status) < 0) {
+				git_push_status_free(status);
+				return -1;
+			}
+			break;
+		case GIT_PKT_NG:
+			status = git__calloc(1, sizeof(push_status));
+			GITERR_CHECK_ALLOC(status);
+			status->ref = git__strdup(((git_pkt_ng *)pkt)->ref);
+			status->msg = git__strdup(((git_pkt_ng *)pkt)->msg);
+			if (!status->ref || !status->msg ||
+				git_vector_insert(&push->status, status) < 0) {
+				git_push_status_free(status);
+				return -1;
+			}
+			break;
+		case GIT_PKT_UNPACK:
+			push->unpack_ok = ((git_pkt_unpack *)pkt)->unpack_ok;
+			break;
+		case GIT_PKT_FLUSH:
+			return GIT_ITEROVER;
+		default:
+			giterr_set(GITERR_NET, "report-status: protocol error");
+			return -1;
+	}
+
+	return 0;
+}
+
+static int add_push_report_sideband_pkt(git_push *push, git_pkt_data *data_pkt, git_buf *data_pkt_buf)
+{
+	git_pkt *pkt;
+	const char *line, *line_end = NULL;
+	size_t line_len;
+	int error;
+	int reading_from_buf = data_pkt_buf->size > 0;
+
+	if (reading_from_buf) {
+		/* We had an existing partial packet, so add the new
+		 * packet to the buffer and parse the whole thing */
+		git_buf_put(data_pkt_buf, data_pkt->data, data_pkt->len);
+		line = data_pkt_buf->ptr;
+		line_len = data_pkt_buf->size;
+	}
+	else {
+		line = data_pkt->data;
+		line_len = data_pkt->len;
+	}
+
+	while (line_len > 0) {
+		error = git_pkt_parse_line(&pkt, line, &line_end, line_len);
+
+		if (error == GIT_EBUFS) {
+			/* Buffer the data when the inner packet is split
+			 * across multiple sideband packets */
+			if (!reading_from_buf)
+				git_buf_put(data_pkt_buf, line, line_len);
+			error = 0;
+			goto done;
+		}
+		else if (error < 0)
+			goto done;
+
+		/* Advance in the buffer */
+		line_len -= (line_end - line);
+		line = line_end;
+
+		error = add_push_report_pkt(push, pkt);
+
+		git_pkt_free(pkt);
+
+		if (error < 0 && error != GIT_ITEROVER)
+			goto done;
+	}
+
+	error = 0;
+
+done:
+	if (reading_from_buf)
+		git_buf_consume(data_pkt_buf, line_end);
+	return error;
+}
+
+static int parse_report(transport_smart *transport, git_push *push)
+{
+	git_pkt *pkt = NULL;
+	const char *line_end = NULL;
+	gitno_buffer *buf = &transport->buffer;
+	int error, recvd;
+	git_buf data_pkt_buf = GIT_BUF_INIT;
+
+	for (;;) {
+		if (buf->offset > 0)
+			error = git_pkt_parse_line(&pkt, buf->data,
+						   &line_end, buf->offset);
+		else
+			error = GIT_EBUFS;
+
+		if (error < 0 && error != GIT_EBUFS) {
+			error = -1;
+			goto done;
+		}
+
+		if (error == GIT_EBUFS) {
+			if ((recvd = gitno_recv(buf)) < 0) {
+				error = recvd;
+				goto done;
+			}
+
+			if (recvd == 0) {
+				giterr_set(GITERR_NET, "early EOF");
+				error = GIT_EEOF;
+				goto done;
+			}
+			continue;
+		}
+
+		gitno_consume(buf, line_end);
+
+		error = 0;
+
+		switch (pkt->type) {
+			case GIT_PKT_DATA:
+				/* This is a sideband packet which contains other packets */
+				error = add_push_report_sideband_pkt(push, (git_pkt_data *)pkt, &data_pkt_buf);
+				break;
+			case GIT_PKT_ERR:
+				giterr_set(GITERR_NET, "report-status: Error reported: %s",
+					((git_pkt_err *)pkt)->error);
+				error = -1;
+				break;
+			case GIT_PKT_PROGRESS:
+				if (transport->progress_cb) {
+					git_pkt_progress *p = (git_pkt_progress *) pkt;
+					error = transport->progress_cb(p->data, p->len, transport->message_cb_payload);
+				}
+				break;
+			default:
+				error = add_push_report_pkt(push, pkt);
+				break;
+		}
+
+		git_pkt_free(pkt);
+
+		/* add_push_report_pkt returns GIT_ITEROVER when it receives a flush */
+		if (error == GIT_ITEROVER) {
+			error = 0;
+			if (data_pkt_buf.size > 0) {
+				/* If there was data remaining in the pack data buffer,
+				 * then the server sent a partial pkt-line */
+				giterr_set(GITERR_NET, "Incomplete pack data pkt-line");
+				error = GIT_ERROR;
+			}
+			goto done;
+		}
+
+		if (error < 0) {
+			goto done;
+		}
+	}
+done:
+	git_buf_free(&data_pkt_buf);
+	return error;
+}
+
+static int add_ref_from_push_spec(git_vector *refs, push_spec *push_spec)
+{
+	git_pkt_ref *added = git__calloc(1, sizeof(git_pkt_ref));
+	GITERR_CHECK_ALLOC(added);
+
+	added->type = GIT_PKT_REF;
+	git_oid_cpy(&added->head.oid, &push_spec->loid);
+	added->head.name = git__strdup(push_spec->refspec.dst);
+
+	if (!added->head.name ||
+		git_vector_insert(refs, added) < 0) {
+		git_pkt_free((git_pkt *)added);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int update_refs_from_report(
+	git_vector *refs,
+	git_vector *push_specs,
+	git_vector *push_report)
+{
+	git_pkt_ref *ref;
+	push_spec *push_spec;
+	push_status *push_status;
+	size_t i, j, refs_len;
+	int cmp;
+
+	/* For each push spec we sent to the server, we should have
+	 * gotten back a status packet in the push report */
+	if (push_specs->length != push_report->length) {
+		giterr_set(GITERR_NET, "report-status: protocol error");
+		return -1;
+	}
+
+	/* We require that push_specs be sorted with push_spec_rref_cmp,
+	 * and that push_report be sorted with push_status_ref_cmp */
+	git_vector_sort(push_specs);
+	git_vector_sort(push_report);
+
+	git_vector_foreach(push_specs, i, push_spec) {
+		push_status = git_vector_get(push_report, i);
+
+		/* For each push spec we sent to the server, we should have
+		 * gotten back a status packet in the push report which matches */
+		if (strcmp(push_spec->refspec.dst, push_status->ref)) {
+			giterr_set(GITERR_NET, "report-status: protocol error");
+			return -1;
+		}
+	}
+
+	/* We require that refs be sorted with ref_name_cmp */
+	git_vector_sort(refs);
+	i = j = 0;
+	refs_len = refs->length;
+
+	/* Merge join push_specs with refs */
+	while (i < push_specs->length && j < refs_len) {
+		push_spec = git_vector_get(push_specs, i);
+		push_status = git_vector_get(push_report, i);
+		ref = git_vector_get(refs, j);
+
+		cmp = strcmp(push_spec->refspec.dst, ref->head.name);
+
+		/* Iterate appropriately */
+		if (cmp <= 0) i++;
+		if (cmp >= 0) j++;
+
+		/* Add case */
+		if (cmp < 0 &&
+			!push_status->msg &&
+			add_ref_from_push_spec(refs, push_spec) < 0)
+			return -1;
+
+		/* Update case, delete case */
+		if (cmp == 0 &&
+			!push_status->msg)
+			git_oid_cpy(&ref->head.oid, &push_spec->loid);
+	}
+
+	for (; i < push_specs->length; i++) {
+		push_spec = git_vector_get(push_specs, i);
+		push_status = git_vector_get(push_report, i);
+
+		/* Add case */
+		if (!push_status->msg &&
+			add_ref_from_push_spec(refs, push_spec) < 0)
+			return -1;
+	}
+
+	/* Remove any refs which we updated to have a zero OID. */
+	git_vector_rforeach(refs, i, ref) {
+		if (git_oid_iszero(&ref->head.oid)) {
+			git_vector_remove(refs, i);
+			git_pkt_free((git_pkt *)ref);
+		}
+	}
+
+	git_vector_sort(refs);
+
+	return 0;
+}
+
+struct push_packbuilder_payload
+{
+	git_smart_subtransport_stream *stream;
+	git_packbuilder *pb;
+	git_push_transfer_progress cb;
+	void *cb_payload;
+	size_t last_bytes;
+	double last_progress_report_time;
+};
+
+static int stream_thunk(void *buf, size_t size, void *data)
+{
+	int error = 0;
+	struct push_packbuilder_payload *payload = data;
+
+	if ((error = payload->stream->write(payload->stream, (const char *)buf, size)) < 0)
+		return error;
+
+	if (payload->cb) {
+		double current_time = git__timer();
+		payload->last_bytes += size;
+
+		if ((current_time - payload->last_progress_report_time) >= MIN_PROGRESS_UPDATE_INTERVAL) {
+			payload->last_progress_report_time = current_time;
+			error = payload->cb(payload->pb->nr_written, payload->pb->nr_objects, payload->last_bytes, payload->cb_payload);
+		}
+	}
+
+	return error;
+}
+
+int git_smart__push(git_transport *transport, git_push *push, const git_remote_callbacks *cbs)
+{
+	transport_smart *t = (transport_smart *)transport;
+	struct push_packbuilder_payload packbuilder_payload = {0};
+	git_buf pktline = GIT_BUF_INIT;
+	int error = 0, need_pack = 0;
+	push_spec *spec;
+	unsigned int i;
+
+	packbuilder_payload.pb = push->pb;
+
+	if (cbs && cbs->push_transfer_progress) {
+		packbuilder_payload.cb = cbs->push_transfer_progress;
+		packbuilder_payload.cb_payload = cbs->payload;
+	}
+
+#ifdef PUSH_DEBUG
+{
+	git_remote_head *head;
+	char hex[GIT_OID_HEXSZ+1]; hex[GIT_OID_HEXSZ] = '\0';
+
+	git_vector_foreach(&push->remote->refs, i, head) {
+		git_oid_fmt(hex, &head->oid);
+		fprintf(stderr, "%s (%s)\n", hex, head->name);
+	}
+
+	git_vector_foreach(&push->specs, i, spec) {
+		git_oid_fmt(hex, &spec->roid);
+		fprintf(stderr, "%s (%s) -> ", hex, spec->lref);
+		git_oid_fmt(hex, &spec->loid);
+		fprintf(stderr, "%s (%s)\n", hex, spec->rref ?
+			spec->rref : spec->lref);
+	}
+}
+#endif
+
+	/*
+	 * Figure out if we need to send a packfile; which is in all
+	 * cases except when we only send delete commands
+	 */
+	git_vector_foreach(&push->specs, i, spec) {
+		if (spec->refspec.src && spec->refspec.src[0] != '\0') {
+			need_pack = 1;
+			break;
+		}
+	}
+
+	if ((error = git_smart__get_push_stream(t, &packbuilder_payload.stream)) < 0 ||
+		(error = gen_pktline(&pktline, push)) < 0 ||
+		(error = packbuilder_payload.stream->write(packbuilder_payload.stream, git_buf_cstr(&pktline), git_buf_len(&pktline))) < 0)
+		goto done;
+
+	if (need_pack &&
+		(error = git_packbuilder_foreach(push->pb, &stream_thunk, &packbuilder_payload)) < 0)
+		goto done;
+
+	/* If we sent nothing or the server doesn't support report-status, then
+	 * we consider the pack to have been unpacked successfully */
+	if (!push->specs.length || !push->report_status)
+		push->unpack_ok = 1;
+	else if ((error = parse_report(t, push)) < 0)
+		goto done;
+
+	/* If progress is being reported write the final report */
+	if (cbs && cbs->push_transfer_progress) {
+		error = cbs->push_transfer_progress(
+					push->pb->nr_written,
+					push->pb->nr_objects,
+					packbuilder_payload.last_bytes,
+					cbs->payload);
+
+		if (error < 0)
+			goto done;
+	}
+
+	if (push->status.length) {
+		error = update_refs_from_report(&t->refs, &push->specs, &push->status);
+		if (error < 0)
+			goto done;
+
+		error = git_smart__update_heads(t, NULL);
+	}
+
+done:
+	git_buf_free(&pktline);
+	return error;
+}

vendor/libgit2-sys/libgit2/src/transports/ssh.c

diff --git a/vendor/libgit2-sys/libgit2/src/transports/ssh.c b/vendor/libgit2-sys/libgit2/src/transports/ssh.c
new file mode 100644
index 0000000..23c6433
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transports/ssh.c
@@ -0,0 +1,927 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "ssh.h"
+
+#ifdef GIT_SSH
+#include <libssh2.h>
+#endif
+
+#include "global.h"
+#include "git2.h"
+#include "buffer.h"
+#include "netops.h"
+#include "smart.h"
+#include "cred.h"
+#include "streams/socket.h"
+
+#ifdef GIT_SSH
+
+#define OWNING_SUBTRANSPORT(s) ((ssh_subtransport *)(s)->parent.subtransport)
+
+static const char *ssh_prefixes[] = { "ssh://", "ssh+git://", "git+ssh://" };
+
+static const char cmd_uploadpack[] = "git-upload-pack";
+static const char cmd_receivepack[] = "git-receive-pack";
+
+typedef struct {
+	git_smart_subtransport_stream parent;
+	git_stream *io;
+	LIBSSH2_SESSION *session;
+	LIBSSH2_CHANNEL *channel;
+	const char *cmd;
+	char *url;
+	unsigned sent_command : 1;
+} ssh_stream;
+
+typedef struct {
+	git_smart_subtransport parent;
+	transport_smart *owner;
+	ssh_stream *current_stream;
+	git_cred *cred;
+	char *cmd_uploadpack;
+	char *cmd_receivepack;
+} ssh_subtransport;
+
+static int list_auth_methods(int *out, LIBSSH2_SESSION *session, const char *username);
+
+static void ssh_error(LIBSSH2_SESSION *session, const char *errmsg)
+{
+	char *ssherr;
+	libssh2_session_last_error(session, &ssherr, NULL, 0);
+
+	giterr_set(GITERR_SSH, "%s: %s", errmsg, ssherr);
+}
+
+/*
+ * Create a git protocol request.
+ *
+ * For example: git-upload-pack '/libgit2/libgit2'
+ */
+static int gen_proto(git_buf *request, const char *cmd, const char *url)
+{
+	const char *repo;
+	int len;
+	size_t i;
+
+	for (i = 0; i < ARRAY_SIZE(ssh_prefixes); ++i) {
+		const char *p = ssh_prefixes[i];
+
+		if (!git__prefixcmp(url, p)) {
+			url = url + strlen(p);
+			repo = strchr(url, '/');
+			if (repo && repo[1] == '~')
+				++repo;
+
+			goto done;
+		}
+	}
+	repo = strchr(url, ':');
+	if (repo) repo++;
+
+done:
+	if (!repo) {
+		giterr_set(GITERR_NET, "malformed git protocol URL");
+		return -1;
+	}
+
+	len = strlen(cmd) + 1 /* Space */ + 1 /* Quote */ + strlen(repo) + 1 /* Quote */ + 1;
+
+	git_buf_grow(request, len);
+	git_buf_puts(request, cmd);
+	git_buf_puts(request, " '");
+	git_buf_decode_percent(request, repo, strlen(repo));
+	git_buf_puts(request, "'");
+
+	if (git_buf_oom(request))
+		return -1;
+
+	return 0;
+}
+
+static int send_command(ssh_stream *s)
+{
+	int error;
+	git_buf request = GIT_BUF_INIT;
+
+	error = gen_proto(&request, s->cmd, s->url);
+	if (error < 0)
+		goto cleanup;
+
+	error = libssh2_channel_exec(s->channel, request.ptr);
+	if (error < LIBSSH2_ERROR_NONE) {
+		ssh_error(s->session, "SSH could not execute request");
+		goto cleanup;
+	}
+
+	s->sent_command = 1;
+
+cleanup:
+	git_buf_free(&request);
+	return error;
+}
+
+static int ssh_stream_read(
+	git_smart_subtransport_stream *stream,
+	char *buffer,
+	size_t buf_size,
+	size_t *bytes_read)
+{
+	int rc;
+	ssh_stream *s = (ssh_stream *)stream;
+
+	*bytes_read = 0;
+
+	if (!s->sent_command && send_command(s) < 0)
+		return -1;
+
+	if ((rc = libssh2_channel_read(s->channel, buffer, buf_size)) < LIBSSH2_ERROR_NONE) {
+		ssh_error(s->session, "SSH could not read data");
+		return -1;
+	}
+
+	/*
+	 * If we can't get anything out of stdout, it's typically a
+	 * not-found error, so read from stderr and signal EOF on
+	 * stderr.
+	 */
+	if (rc == 0) {
+		if ((rc = libssh2_channel_read_stderr(s->channel, buffer, buf_size)) > 0) {
+			giterr_set(GITERR_SSH, "%*s", rc, buffer);
+			return GIT_EEOF;
+		} else if (rc < LIBSSH2_ERROR_NONE) {
+			ssh_error(s->session, "SSH could not read stderr");
+			return -1;
+		}
+	}
+
+
+	*bytes_read = rc;
+
+	return 0;
+}
+
+static int ssh_stream_write(
+	git_smart_subtransport_stream *stream,
+	const char *buffer,
+	size_t len)
+{
+	ssh_stream *s = (ssh_stream *)stream;
+	size_t off = 0;
+	ssize_t ret = 0;
+
+	if (!s->sent_command && send_command(s) < 0)
+		return -1;
+
+	do {
+		ret = libssh2_channel_write(s->channel, buffer + off, len - off);
+		if (ret < 0)
+			break;
+
+		off += ret;
+
+	} while (off < len);
+
+	if (ret < 0) {
+		ssh_error(s->session, "SSH could not write data");
+		return -1;
+	}
+
+	return 0;
+}
+
+static void ssh_stream_free(git_smart_subtransport_stream *stream)
+{
+	ssh_stream *s = (ssh_stream *)stream;
+	ssh_subtransport *t;
+
+	if (!stream)
+		return;
+
+	t = OWNING_SUBTRANSPORT(s);
+	t->current_stream = NULL;
+
+	if (s->channel) {
+		libssh2_channel_close(s->channel);
+		libssh2_channel_free(s->channel);
+		s->channel = NULL;
+	}
+
+	if (s->session) {
+		libssh2_session_disconnect(s->session, "closing transport");
+		libssh2_session_free(s->session);
+		s->session = NULL;
+	}
+
+	if (s->io) {
+		git_stream_close(s->io);
+		git_stream_free(s->io);
+		s->io = NULL;
+	}
+
+	git__free(s->url);
+	git__free(s);
+}
+
+static int ssh_stream_alloc(
+	ssh_subtransport *t,
+	const char *url,
+	const char *cmd,
+	git_smart_subtransport_stream **stream)
+{
+	ssh_stream *s;
+
+	assert(stream);
+
+	s = git__calloc(sizeof(ssh_stream), 1);
+	GITERR_CHECK_ALLOC(s);
+
+	s->parent.subtransport = &t->parent;
+	s->parent.read = ssh_stream_read;
+	s->parent.write = ssh_stream_write;
+	s->parent.free = ssh_stream_free;
+
+	s->cmd = cmd;
+
+	s->url = git__strdup(url);
+	if (!s->url) {
+		git__free(s);
+		return -1;
+	}
+
+	*stream = &s->parent;
+	return 0;
+}
+
+static int git_ssh_extract_url_parts(
+	char **host,
+	char **username,
+	const char *url)
+{
+	char *colon, *at;
+	const char *start;
+
+	colon = strchr(url, ':');
+
+
+	at = strchr(url, '@');
+	if (at) {
+		start = at + 1;
+		*username = git__substrdup(url, at - url);
+		GITERR_CHECK_ALLOC(*username);
+	} else {
+		start = url;
+		*username = NULL;
+	}
+
+	if (colon == NULL || (colon < start)) {
+		giterr_set(GITERR_NET, "malformed URL");
+		return -1;
+	}
+
+	*host = git__substrdup(start, colon - start);
+	GITERR_CHECK_ALLOC(*host);
+
+	return 0;
+}
+
+static int ssh_agent_auth(LIBSSH2_SESSION *session, git_cred_ssh_key *c) {
+	int rc = LIBSSH2_ERROR_NONE;
+
+	struct libssh2_agent_publickey *curr, *prev = NULL;
+
+	LIBSSH2_AGENT *agent = libssh2_agent_init(session);
+
+	if (agent == NULL)
+		return -1;
+
+	rc = libssh2_agent_connect(agent);
+
+	if (rc != LIBSSH2_ERROR_NONE)
+		goto shutdown;
+
+	rc = libssh2_agent_list_identities(agent);
+
+	if (rc != LIBSSH2_ERROR_NONE)
+		goto shutdown;
+
+	while (1) {
+		rc = libssh2_agent_get_identity(agent, &curr, prev);
+
+		if (rc < 0)
+			goto shutdown;
+
+		/* rc is set to 1 whenever the ssh agent ran out of keys to check.
+		 * Set the error code to authentication failure rather than erroring
+		 * out with an untranslatable error code.
+		 */
+		if (rc == 1) {
+			rc = LIBSSH2_ERROR_AUTHENTICATION_FAILED;
+			goto shutdown;
+		}
+
+		rc = libssh2_agent_userauth(agent, c->username, curr);
+
+		if (rc == 0)
+			break;
+
+		prev = curr;
+	}
+
+shutdown:
+
+	if (rc != LIBSSH2_ERROR_NONE)
+		ssh_error(session, "error authenticating");
+
+	libssh2_agent_disconnect(agent);
+	libssh2_agent_free(agent);
+
+	return rc;
+}
+
+static int _git_ssh_authenticate_session(
+	LIBSSH2_SESSION* session,
+	git_cred* cred)
+{
+	int rc;
+
+	do {
+		giterr_clear();
+		switch (cred->credtype) {
+		case GIT_CREDTYPE_USERPASS_PLAINTEXT: {
+			git_cred_userpass_plaintext *c = (git_cred_userpass_plaintext *)cred;
+			rc = libssh2_userauth_password(session, c->username, c->password);
+			break;
+		}
+		case GIT_CREDTYPE_SSH_KEY: {
+			git_cred_ssh_key *c = (git_cred_ssh_key *)cred;
+
+			if (c->privatekey)
+				rc = libssh2_userauth_publickey_fromfile(
+					session, c->username, c->publickey,
+					c->privatekey, c->passphrase);
+			else
+				rc = ssh_agent_auth(session, c);
+
+			break;
+		}
+		case GIT_CREDTYPE_SSH_CUSTOM: {
+			git_cred_ssh_custom *c = (git_cred_ssh_custom *)cred;
+
+			rc = libssh2_userauth_publickey(
+				session, c->username, (const unsigned char *)c->publickey,
+				c->publickey_len, c->sign_callback, &c->payload);
+			break;
+		}
+		case GIT_CREDTYPE_SSH_INTERACTIVE: {
+			void **abstract = libssh2_session_abstract(session);
+			git_cred_ssh_interactive *c = (git_cred_ssh_interactive *)cred;
+
+			/* ideally, we should be able to set this by calling
+			 * libssh2_session_init_ex() instead of libssh2_session_init().
+			 * libssh2's API is inconsistent here i.e. libssh2_userauth_publickey()
+			 * allows you to pass the `abstract` as part of the call, whereas
+			 * libssh2_userauth_keyboard_interactive() does not!
+			 *
+			 * The only way to set the `abstract` pointer is by calling
+			 * libssh2_session_abstract(), which will replace the existing
+			 * pointer as is done below. This is safe for now (at time of writing),
+			 * but may not be valid in future.
+			 */
+			*abstract = c->payload;
+
+			rc = libssh2_userauth_keyboard_interactive(
+				session, c->username, c->prompt_callback);
+			break;
+		}
+#ifdef GIT_SSH_MEMORY_CREDENTIALS
+		case GIT_CREDTYPE_SSH_MEMORY: {
+			git_cred_ssh_key *c = (git_cred_ssh_key *)cred;
+
+			assert(c->username);
+			assert(c->privatekey);
+
+			rc = libssh2_userauth_publickey_frommemory(
+				session,
+				c->username,
+				strlen(c->username),
+				c->publickey,
+				c->publickey ? strlen(c->publickey) : 0,
+				c->privatekey,
+				strlen(c->privatekey),
+				c->passphrase);
+			break;
+		}
+#endif
+		default:
+			rc = LIBSSH2_ERROR_AUTHENTICATION_FAILED;
+		}
+	} while (LIBSSH2_ERROR_EAGAIN == rc || LIBSSH2_ERROR_TIMEOUT == rc);
+
+	if (rc == LIBSSH2_ERROR_PASSWORD_EXPIRED ||
+		rc == LIBSSH2_ERROR_AUTHENTICATION_FAILED ||
+		rc == LIBSSH2_ERROR_PUBLICKEY_UNVERIFIED)
+			return GIT_EAUTH;
+
+	if (rc != LIBSSH2_ERROR_NONE) {
+		if (!giterr_last())
+			ssh_error(session, "Failed to authenticate SSH session");
+		return -1;
+	}
+
+	return 0;
+}
+
+static int request_creds(git_cred **out, ssh_subtransport *t, const char *user, int auth_methods)
+{
+	int error, no_callback = 0;
+	git_cred *cred = NULL;
+
+	if (!t->owner->cred_acquire_cb) {
+		no_callback = 1;
+	} else {
+		error = t->owner->cred_acquire_cb(&cred, t->owner->url, user, auth_methods,
+						  t->owner->cred_acquire_payload);
+
+		if (error == GIT_PASSTHROUGH)
+			no_callback = 1;
+		else if (error < 0)
+			return error;
+		else if (!cred) {
+			giterr_set(GITERR_SSH, "callback failed to initialize SSH credentials");
+			return -1;
+		}
+	}
+
+	if (no_callback) {
+		giterr_set(GITERR_SSH, "authentication required but no callback set");
+		return -1;
+	}
+
+	if (!(cred->credtype & auth_methods)) {
+		cred->free(cred);
+		giterr_set(GITERR_SSH, "callback returned unsupported credentials type");
+		return -1;
+	}
+
+	*out = cred;
+
+	return 0;
+}
+
+static int _git_ssh_session_create(
+	LIBSSH2_SESSION** session,
+	git_stream *io)
+{
+	int rc = 0;
+	LIBSSH2_SESSION* s;
+	git_socket_stream *socket = (git_socket_stream *) io;
+
+	assert(session);
+
+	s = libssh2_session_init();
+	if (!s) {
+		giterr_set(GITERR_NET, "failed to initialize SSH session");
+		return -1;
+	}
+
+	do {
+		rc = libssh2_session_handshake(s, socket->s);
+	} while (LIBSSH2_ERROR_EAGAIN == rc || LIBSSH2_ERROR_TIMEOUT == rc);
+
+	if (rc != LIBSSH2_ERROR_NONE) {
+		ssh_error(s, "failed to start SSH session");
+		libssh2_session_free(s);
+		return -1;
+	}
+
+	libssh2_session_set_blocking(s, 1);
+
+	*session = s;
+
+	return 0;
+}
+
+static int _git_ssh_setup_conn(
+	ssh_subtransport *t,
+	const char *url,
+	const char *cmd,
+	git_smart_subtransport_stream **stream)
+{
+	char *host=NULL, *port=NULL, *path=NULL, *user=NULL, *pass=NULL;
+	const char *default_port="22";
+	int auth_methods, error = 0;
+	size_t i;
+	ssh_stream *s;
+	git_cred *cred = NULL;
+	LIBSSH2_SESSION* session=NULL;
+	LIBSSH2_CHANNEL* channel=NULL;
+
+	t->current_stream = NULL;
+
+	*stream = NULL;
+	if (ssh_stream_alloc(t, url, cmd, stream) < 0)
+		return -1;
+
+	s = (ssh_stream *)*stream;
+	s->session = NULL;
+	s->channel = NULL;
+
+	for (i = 0; i < ARRAY_SIZE(ssh_prefixes); ++i) {
+		const char *p = ssh_prefixes[i];
+
+		if (!git__prefixcmp(url, p)) {
+			if ((error = gitno_extract_url_parts(&host, &port, &path, &user, &pass, url, default_port)) < 0)
+				goto done;
+
+			goto post_extract;
+		}
+	}
+	if ((error = git_ssh_extract_url_parts(&host, &user, url)) < 0)
+		goto done;
+	port = git__strdup(default_port);
+	GITERR_CHECK_ALLOC(port);
+
+post_extract:
+	if ((error = git_socket_stream_new(&s->io, host, port)) < 0 ||
+	    (error = git_stream_connect(s->io)) < 0)
+		goto done;
+
+	if ((error = _git_ssh_session_create(&session, s->io)) < 0)
+		goto done;
+
+	if (t->owner->certificate_check_cb != NULL) {
+		git_cert_hostkey cert = {{ 0 }}, *cert_ptr;
+		const char *key;
+
+		cert.parent.cert_type = GIT_CERT_HOSTKEY_LIBSSH2;
+
+		key = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_SHA1);
+		if (key != NULL) {
+			cert.type |= GIT_CERT_SSH_SHA1;
+			memcpy(&cert.hash_sha1, key, 20);
+		}
+
+		key = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_MD5);
+		if (key != NULL) {
+			cert.type |= GIT_CERT_SSH_MD5;
+			memcpy(&cert.hash_md5, key, 16);
+		}
+
+		if (cert.type == 0) {
+			giterr_set(GITERR_SSH, "unable to get the host key");
+			error = -1;
+			goto done;
+		}
+
+		/* We don't currently trust any hostkeys */
+		giterr_clear();
+
+		cert_ptr = &cert;
+
+		error = t->owner->certificate_check_cb((git_cert *) cert_ptr, 0, host, t->owner->message_cb_payload);
+		if (error < 0) {
+			if (!giterr_last())
+				giterr_set(GITERR_NET, "user cancelled hostkey check");
+
+			goto done;
+		}
+	}
+
+	/* we need the username to ask for auth methods */
+	if (!user) {
+		if ((error = request_creds(&cred, t, NULL, GIT_CREDTYPE_USERNAME)) < 0)
+			goto done;
+
+		user = git__strdup(((git_cred_username *) cred)->username);
+		cred->free(cred);
+		cred = NULL;
+		if (!user)
+			goto done;
+	} else if (user && pass) {
+		if ((error = git_cred_userpass_plaintext_new(&cred, user, pass)) < 0)
+			goto done;
+	}
+
+	if ((error = list_auth_methods(&auth_methods, session, user)) < 0)
+		goto done;
+
+	error = GIT_EAUTH;
+	/* if we already have something to try */
+	if (cred && auth_methods & cred->credtype)
+		error = _git_ssh_authenticate_session(session, cred);
+
+	while (error == GIT_EAUTH) {
+		if (cred) {
+			cred->free(cred);
+			cred = NULL;
+		}
+
+		if ((error = request_creds(&cred, t, user, auth_methods)) < 0)
+			goto done;
+
+		if (strcmp(user, git_cred__username(cred))) {
+			giterr_set(GITERR_SSH, "username does not match previous request");
+			error = -1;
+			goto done;
+		}
+
+		error = _git_ssh_authenticate_session(session, cred);
+	}
+
+	if (error < 0)
+		goto done;
+
+	channel = libssh2_channel_open_session(session);
+	if (!channel) {
+		error = -1;
+		ssh_error(session, "Failed to open SSH channel");
+		goto done;
+	}
+
+	libssh2_channel_set_blocking(channel, 1);
+
+	s->session = session;
+	s->channel = channel;
+
+	t->current_stream = s;
+
+done:
+	if (error < 0) {
+		ssh_stream_free(*stream);
+
+		if (session)
+			libssh2_session_free(session);
+	}
+
+	if (cred)
+		cred->free(cred);
+
+	git__free(host);
+	git__free(port);
+	git__free(path);
+	git__free(user);
+	git__free(pass);
+
+	return error;
+}
+
+static int ssh_uploadpack_ls(
+	ssh_subtransport *t,
+	const char *url,
+	git_smart_subtransport_stream **stream)
+{
+	const char *cmd = t->cmd_uploadpack ? t->cmd_uploadpack : cmd_uploadpack;
+
+	return _git_ssh_setup_conn(t, url, cmd, stream);
+}
+
+static int ssh_uploadpack(
+	ssh_subtransport *t,
+	const char *url,
+	git_smart_subtransport_stream **stream)
+{
+	GIT_UNUSED(url);
+
+	if (t->current_stream) {
+		*stream = &t->current_stream->parent;
+		return 0;
+	}
+
+	giterr_set(GITERR_NET, "must call UPLOADPACK_LS before UPLOADPACK");
+	return -1;
+}
+
+static int ssh_receivepack_ls(
+	ssh_subtransport *t,
+	const char *url,
+	git_smart_subtransport_stream **stream)
+{
+	const char *cmd = t->cmd_receivepack ? t->cmd_receivepack : cmd_receivepack;
+
+
+	return _git_ssh_setup_conn(t, url, cmd, stream);
+}
+
+static int ssh_receivepack(
+	ssh_subtransport *t,
+	const char *url,
+	git_smart_subtransport_stream **stream)
+{
+	GIT_UNUSED(url);
+
+	if (t->current_stream) {
+		*stream = &t->current_stream->parent;
+		return 0;
+	}
+
+	giterr_set(GITERR_NET, "must call RECEIVEPACK_LS before RECEIVEPACK");
+	return -1;
+}
+
+static int _ssh_action(
+	git_smart_subtransport_stream **stream,
+	git_smart_subtransport *subtransport,
+	const char *url,
+	git_smart_service_t action)
+{
+	ssh_subtransport *t = (ssh_subtransport *) subtransport;
+
+	switch (action) {
+		case GIT_SERVICE_UPLOADPACK_LS:
+			return ssh_uploadpack_ls(t, url, stream);
+
+		case GIT_SERVICE_UPLOADPACK:
+			return ssh_uploadpack(t, url, stream);
+
+		case GIT_SERVICE_RECEIVEPACK_LS:
+			return ssh_receivepack_ls(t, url, stream);
+
+		case GIT_SERVICE_RECEIVEPACK:
+			return ssh_receivepack(t, url, stream);
+	}
+
+	*stream = NULL;
+	return -1;
+}
+
+static int _ssh_close(git_smart_subtransport *subtransport)
+{
+	ssh_subtransport *t = (ssh_subtransport *) subtransport;
+
+	assert(!t->current_stream);
+
+	GIT_UNUSED(t);
+
+	return 0;
+}
+
+static void _ssh_free(git_smart_subtransport *subtransport)
+{
+	ssh_subtransport *t = (ssh_subtransport *) subtransport;
+
+	assert(!t->current_stream);
+
+	git__free(t->cmd_uploadpack);
+	git__free(t->cmd_receivepack);
+	git__free(t);
+}
+
+#define SSH_AUTH_PUBLICKEY "publickey"
+#define SSH_AUTH_PASSWORD "password"
+#define SSH_AUTH_KEYBOARD_INTERACTIVE "keyboard-interactive"
+
+static int list_auth_methods(int *out, LIBSSH2_SESSION *session, const char *username)
+{
+	const char *list, *ptr;
+
+	*out = 0;
+
+	list = libssh2_userauth_list(session, username, strlen(username));
+
+	/* either error, or the remote accepts NONE auth, which is bizarre, let's punt */
+	if (list == NULL && !libssh2_userauth_authenticated(session)) {
+		ssh_error(session, "Failed to retrieve list of SSH authentication methods");
+		return -1;
+	}
+
+	ptr = list;
+	while (ptr) {
+		if (*ptr == ',')
+			ptr++;
+
+		if (!git__prefixcmp(ptr, SSH_AUTH_PUBLICKEY)) {
+			*out |= GIT_CREDTYPE_SSH_KEY;
+			*out |= GIT_CREDTYPE_SSH_CUSTOM;
+#ifdef GIT_SSH_MEMORY_CREDENTIALS
+			*out |= GIT_CREDTYPE_SSH_MEMORY;
+#endif
+			ptr += strlen(SSH_AUTH_PUBLICKEY);
+			continue;
+		}
+
+		if (!git__prefixcmp(ptr, SSH_AUTH_PASSWORD)) {
+			*out |= GIT_CREDTYPE_USERPASS_PLAINTEXT;
+			ptr += strlen(SSH_AUTH_PASSWORD);
+			continue;
+		}
+
+		if (!git__prefixcmp(ptr, SSH_AUTH_KEYBOARD_INTERACTIVE)) {
+			*out |= GIT_CREDTYPE_SSH_INTERACTIVE;
+			ptr += strlen(SSH_AUTH_KEYBOARD_INTERACTIVE);
+			continue;
+		}
+
+		/* Skipt it if we don't know it */
+		ptr = strchr(ptr, ',');
+	}
+
+	return 0;
+}
+#endif
+
+int git_smart_subtransport_ssh(
+	git_smart_subtransport **out, git_transport *owner, void *param)
+{
+#ifdef GIT_SSH
+	ssh_subtransport *t;
+
+	assert(out);
+
+	GIT_UNUSED(param);
+
+	t = git__calloc(sizeof(ssh_subtransport), 1);
+	GITERR_CHECK_ALLOC(t);
+
+	t->owner = (transport_smart *)owner;
+	t->parent.action = _ssh_action;
+	t->parent.close = _ssh_close;
+	t->parent.free = _ssh_free;
+
+	*out = (git_smart_subtransport *) t;
+	return 0;
+#else
+	GIT_UNUSED(owner);
+	GIT_UNUSED(param);
+
+	assert(out);
+	*out = NULL;
+
+	giterr_set(GITERR_INVALID, "cannot create SSH transport. Library was built without SSH support");
+	return -1;
+#endif
+}
+
+int git_transport_ssh_with_paths(git_transport **out, git_remote *owner, void *payload)
+{
+#ifdef GIT_SSH
+	git_strarray *paths = (git_strarray *) payload;
+	git_transport *transport;
+	transport_smart *smart;
+	ssh_subtransport *t;
+	int error;
+	git_smart_subtransport_definition ssh_definition = {
+		git_smart_subtransport_ssh,
+		0, /* no RPC */
+		NULL,
+	};
+
+	if (paths->count != 2) {
+		giterr_set(GITERR_SSH, "invalid ssh paths, must be two strings");
+		return GIT_EINVALIDSPEC;
+	}
+
+	if ((error = git_transport_smart(&transport, owner, &ssh_definition)) < 0)
+		return error;
+
+	smart = (transport_smart *) transport;
+	t = (ssh_subtransport *) smart->wrapped;
+
+	t->cmd_uploadpack = git__strdup(paths->strings[0]);
+	GITERR_CHECK_ALLOC(t->cmd_uploadpack);
+	t->cmd_receivepack = git__strdup(paths->strings[1]);
+	GITERR_CHECK_ALLOC(t->cmd_receivepack);
+
+	*out = transport;
+	return 0;
+#else
+	GIT_UNUSED(owner);
+	GIT_UNUSED(payload);
+
+	assert(out);
+	*out = NULL;
+
+	giterr_set(GITERR_INVALID, "cannot create SSH transport. Library was built without SSH support");
+	return -1;
+#endif
+}
+
+#ifdef GIT_SSH
+static void shutdown_ssh(void)
+{
+    libssh2_exit();
+}
+#endif
+
+int git_transport_ssh_global_init(void)
+{
+#ifdef GIT_SSH
+	if (libssh2_init(0) < 0) {
+		giterr_set(GITERR_SSH, "unable to initialize libssh2");
+		return -1;
+	}
+
+	git__on_shutdown(shutdown_ssh);
+	return 0;
+
+#else
+
+	/* Nothing to initialize */
+	return 0;
+
+#endif
+}

vendor/libgit2-sys/libgit2/src/transports/ssh.h

diff --git a/vendor/libgit2-sys/libgit2/src/transports/ssh.h b/vendor/libgit2-sys/libgit2/src/transports/ssh.h
new file mode 100644
index 0000000..d3e741f
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transports/ssh.h
@@ -0,0 +1,14 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_transports_ssh_h__
+#define INCLUDE_transports_ssh_h__
+
+#include "common.h"
+
+int git_transport_ssh_global_init(void);
+
+#endif

vendor/libgit2-sys/libgit2/src/transports/winhttp.c

diff --git a/vendor/libgit2-sys/libgit2/src/transports/winhttp.c b/vendor/libgit2-sys/libgit2/src/transports/winhttp.c
new file mode 100644
index 0000000..e52d54b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/transports/winhttp.c
@@ -0,0 +1,1609 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#ifdef GIT_WINHTTP
+
+#include "git2.h"
+#include "git2/transport.h"
+#include "buffer.h"
+#include "posix.h"
+#include "netops.h"
+#include "smart.h"
+#include "remote.h"
+#include "repository.h"
+#include "global.h"
+#include "http.h"
+
+#include <wincrypt.h>
+#include <winhttp.h>
+
+/* For IInternetSecurityManager zone check */
+#include <objbase.h>
+#include <urlmon.h>
+
+#define WIDEN2(s) L ## s
+#define WIDEN(s) WIDEN2(s)
+
+#define MAX_CONTENT_TYPE_LEN	100
+#define WINHTTP_OPTION_PEERDIST_EXTENSION_STATE	109
+#define CACHED_POST_BODY_BUF_SIZE	4096
+#define UUID_LENGTH_CCH	32
+#define TIMEOUT_INFINITE -1
+#define DEFAULT_CONNECT_TIMEOUT 60000
+#ifndef WINHTTP_IGNORE_REQUEST_TOTAL_LENGTH
+#define WINHTTP_IGNORE_REQUEST_TOTAL_LENGTH 0
+#endif
+
+#ifndef WINHTTP_FLAG_SECURE_PROTOCOL_TLS_1_1
+# define WINHTTP_FLAG_SECURE_PROTOCOL_TLS1_1 0x00000200
+#endif
+
+#ifndef WINHTTP_FLAG_SECURE_PROTOCOL_TLS_1_2
+# define WINHTTP_FLAG_SECURE_PROTOCOL_TLS1_2 0x00000800
+#endif
+
+static const char *prefix_https = "https://";
+static const char *upload_pack_service = "upload-pack";
+static const char *upload_pack_ls_service_url = "/info/refs?service=git-upload-pack";
+static const char *upload_pack_service_url = "/git-upload-pack";
+static const char *receive_pack_service = "receive-pack";
+static const char *receive_pack_ls_service_url = "/info/refs?service=git-receive-pack";
+static const char *receive_pack_service_url = "/git-receive-pack";
+static const wchar_t *get_verb = L"GET";
+static const wchar_t *post_verb = L"POST";
+static const wchar_t *pragma_nocache = L"Pragma: no-cache";
+static const wchar_t *transfer_encoding = L"Transfer-Encoding: chunked";
+static const int no_check_cert_flags = SECURITY_FLAG_IGNORE_CERT_CN_INVALID |
+	SECURITY_FLAG_IGNORE_CERT_DATE_INVALID |
+	SECURITY_FLAG_IGNORE_UNKNOWN_CA;
+
+#if defined(__MINGW32__)
+static const CLSID CLSID_InternetSecurityManager_mingw =
+	{ 0x7B8A2D94, 0x0AC9, 0x11D1,
+	{ 0x89, 0x6C, 0x00, 0xC0, 0x4F, 0xB6, 0xBF, 0xC4 } };
+static const IID IID_IInternetSecurityManager_mingw =
+	{ 0x79EAC9EE, 0xBAF9, 0x11CE,
+	{ 0x8C, 0x82, 0x00, 0xAA, 0x00, 0x4B, 0xA9, 0x0B } };
+
+# define CLSID_InternetSecurityManager CLSID_InternetSecurityManager_mingw
+# define IID_IInternetSecurityManager IID_IInternetSecurityManager_mingw
+#endif
+
+#define OWNING_SUBTRANSPORT(s) ((winhttp_subtransport *)(s)->parent.subtransport)
+
+typedef enum {
+	GIT_WINHTTP_AUTH_BASIC = 1,
+	GIT_WINHTTP_AUTH_NTLM = 2,
+	GIT_WINHTTP_AUTH_NEGOTIATE = 4,
+	GIT_WINHTTP_AUTH_DIGEST = 8,
+} winhttp_authmechanism_t;
+
+typedef struct {
+	git_smart_subtransport_stream parent;
+	const char *service;
+	const char *service_url;
+	const wchar_t *verb;
+	HINTERNET request;
+	wchar_t *request_uri;
+	char *chunk_buffer;
+	unsigned chunk_buffer_len;
+	HANDLE post_body;
+	DWORD post_body_len;
+	unsigned sent_request : 1,
+		received_response : 1,
+		chunked : 1;
+} winhttp_stream;
+
+typedef struct {
+	git_smart_subtransport parent;
+	transport_smart *owner;
+	gitno_connection_data connection_data;
+	gitno_connection_data proxy_connection_data;
+	git_cred *cred;
+	git_cred *url_cred;
+	git_cred *proxy_cred;
+	int auth_mechanisms;
+	HINTERNET session;
+	HINTERNET connection;
+} winhttp_subtransport;
+
+static int _apply_userpass_credential(HINTERNET request, DWORD target, DWORD scheme, git_cred *cred)
+{
+	git_cred_userpass_plaintext *c = (git_cred_userpass_plaintext *)cred;
+	wchar_t *user, *pass;
+	int user_len = 0, pass_len = 0, error = 0;
+
+	if ((error = user_len = git__utf8_to_16_alloc(&user, c->username)) < 0)
+		goto done;
+
+	if ((error = pass_len = git__utf8_to_16_alloc(&pass, c->password)) < 0)
+		goto done;
+
+	if (!WinHttpSetCredentials(request, target, scheme, user, pass, NULL)) {
+		giterr_set(GITERR_OS, "failed to set credentials");
+		error = -1;
+	}
+
+done:
+	if (user_len > 0)
+		git__memzero(user, user_len * sizeof(wchar_t));
+
+	if (pass_len > 0)
+		git__memzero(pass, pass_len * sizeof(wchar_t));
+
+	git__free(user);
+	git__free(pass);
+
+	return error;
+}
+
+static int apply_userpass_credential_proxy(HINTERNET request, git_cred *cred, int mechanisms)
+{
+	if (GIT_WINHTTP_AUTH_DIGEST & mechanisms) {
+		return _apply_userpass_credential(request, WINHTTP_AUTH_TARGET_PROXY,
+			WINHTTP_AUTH_SCHEME_DIGEST, cred);
+	}
+
+	return _apply_userpass_credential(request, WINHTTP_AUTH_TARGET_PROXY,
+		WINHTTP_AUTH_SCHEME_BASIC, cred);
+}
+
+static int apply_userpass_credential(HINTERNET request, int mechanisms, git_cred *cred)
+{
+	DWORD native_scheme;
+
+	if ((mechanisms & GIT_WINHTTP_AUTH_NTLM) ||
+		(mechanisms & GIT_WINHTTP_AUTH_NEGOTIATE)) {
+		native_scheme = WINHTTP_AUTH_SCHEME_NTLM;
+	} else if (mechanisms & GIT_WINHTTP_AUTH_BASIC) {
+		native_scheme = WINHTTP_AUTH_SCHEME_BASIC;
+	} else {
+		giterr_set(GITERR_NET, "invalid authentication scheme");
+		return -1;
+	}
+
+	return _apply_userpass_credential(request, WINHTTP_AUTH_TARGET_SERVER,
+		native_scheme, cred);
+}
+
+static int apply_default_credentials(HINTERNET request, int mechanisms)
+{
+	/* Either the caller explicitly requested that default credentials be passed,
+	 * or our fallback credential callback was invoked and checked that the target
+	 * URI was in the appropriate Internet Explorer security zone. By setting this
+	 * flag, we guarantee that the credentials are delivered by WinHTTP. The default
+	 * is "medium" which applies to the intranet and sounds like it would correspond
+	 * to Internet Explorer security zones, but in fact does not. */
+	DWORD data = WINHTTP_AUTOLOGON_SECURITY_LEVEL_LOW;
+	DWORD native_scheme = 0;
+
+	if ((mechanisms & GIT_WINHTTP_AUTH_NTLM) != 0)
+		native_scheme |= WINHTTP_AUTH_SCHEME_NTLM;
+
+	if ((mechanisms & GIT_WINHTTP_AUTH_NEGOTIATE) != 0)
+		native_scheme |= WINHTTP_AUTH_SCHEME_NEGOTIATE;
+
+	if (!native_scheme) {
+		giterr_set(GITERR_NET, "invalid authentication scheme");
+		return -1;
+	}
+
+	if (!WinHttpSetOption(request, WINHTTP_OPTION_AUTOLOGON_POLICY, &data, sizeof(DWORD)))
+		return -1;
+
+	if (!WinHttpSetCredentials(request, WINHTTP_AUTH_TARGET_SERVER, native_scheme, NULL, NULL, NULL))
+		return -1;
+
+	return 0;
+}
+
+static int fallback_cred_acquire_cb(
+	git_cred **cred,
+	const char *url,
+	const char *username_from_url,
+	unsigned int allowed_types,
+	void *payload)
+{
+	int error = 1;
+
+	GIT_UNUSED(username_from_url);
+	GIT_UNUSED(payload);
+
+	/* If the target URI supports integrated Windows authentication
+	 * as an authentication mechanism */
+	if (GIT_CREDTYPE_DEFAULT & allowed_types) {
+		wchar_t *wide_url;
+
+		/* Convert URL to wide characters */
+		if (git__utf8_to_16_alloc(&wide_url, url) < 0) {
+			giterr_set(GITERR_OS, "failed to convert string to wide form");
+			return -1;
+		}
+
+		if (SUCCEEDED(CoInitializeEx(NULL, COINIT_MULTITHREADED))) {
+			IInternetSecurityManager* pISM;
+
+			/* And if the target URI is in the My Computer, Intranet, or Trusted zones */
+			if (SUCCEEDED(CoCreateInstance(&CLSID_InternetSecurityManager, NULL,
+				CLSCTX_ALL, &IID_IInternetSecurityManager, (void **)&pISM))) {
+				DWORD dwZone;
+
+				if (SUCCEEDED(pISM->lpVtbl->MapUrlToZone(pISM, wide_url, &dwZone, 0)) &&
+					(URLZONE_LOCAL_MACHINE == dwZone ||
+					URLZONE_INTRANET == dwZone ||
+					URLZONE_TRUSTED == dwZone)) {
+					git_cred *existing = *cred;
+
+					if (existing)
+						existing->free(existing);
+
+					/* Then use default Windows credentials to authenticate this request */
+					error = git_cred_default_new(cred);
+				}
+
+				pISM->lpVtbl->Release(pISM);
+			}
+
+			CoUninitialize();
+		}
+
+		git__free(wide_url);
+	}
+
+	return error;
+}
+
+static int certificate_check(winhttp_stream *s, int valid)
+{
+	int error;
+	winhttp_subtransport *t = OWNING_SUBTRANSPORT(s);
+	PCERT_CONTEXT cert_ctx;
+	DWORD cert_ctx_size = sizeof(cert_ctx);
+	git_cert_x509 cert;
+
+	/* If there is no override, we should fail if WinHTTP doesn't think it's fine */
+	if (t->owner->certificate_check_cb == NULL && !valid) {
+		if (!giterr_last())
+			giterr_set(GITERR_NET, "unknown certificate check failure");
+
+		return GIT_ECERTIFICATE;
+	}
+
+	if (t->owner->certificate_check_cb == NULL || !t->connection_data.use_ssl)
+		return 0;
+
+	if (!WinHttpQueryOption(s->request, WINHTTP_OPTION_SERVER_CERT_CONTEXT, &cert_ctx, &cert_ctx_size)) {
+		giterr_set(GITERR_OS, "failed to get server certificate");
+		return -1;
+	}
+
+	giterr_clear();
+	cert.parent.cert_type = GIT_CERT_X509;
+	cert.data = cert_ctx->pbCertEncoded;
+	cert.len = cert_ctx->cbCertEncoded;
+	error = t->owner->certificate_check_cb((git_cert *) &cert, valid, t->connection_data.host, t->owner->message_cb_payload);
+	CertFreeCertificateContext(cert_ctx);
+
+	if (error < 0 && !giterr_last())
+		giterr_set(GITERR_NET, "user cancelled certificate check");
+
+	return error;
+}
+
+static void winhttp_stream_close(winhttp_stream *s)
+{
+	if (s->chunk_buffer) {
+		git__free(s->chunk_buffer);
+		s->chunk_buffer = NULL;
+	}
+
+	if (s->post_body) {
+		CloseHandle(s->post_body);
+		s->post_body = NULL;
+	}
+
+	if (s->request_uri) {
+		git__free(s->request_uri);
+		s->request_uri = NULL;
+	}
+
+	if (s->request) {
+		WinHttpCloseHandle(s->request);
+		s->request = NULL;
+	}
+
+	s->sent_request = 0;
+}
+
+/**
+ * Extract the url and password from a URL. The outputs are pointers
+ * into the input.
+ */
+static int userpass_from_url(wchar_t **user, int *user_len,
+			     wchar_t **pass, int *pass_len,
+			     const wchar_t *url, int url_len)
+{
+	URL_COMPONENTS components = { 0 };
+
+	components.dwStructSize = sizeof(components);
+	/* These tell WinHttpCrackUrl that we're interested in the fields */
+	components.dwUserNameLength = 1;
+	components.dwPasswordLength = 1;
+
+	if (!WinHttpCrackUrl(url, url_len, 0, &components)) {
+		giterr_set(GITERR_OS, "failed to extract user/pass from url");
+		return -1;
+	}
+
+	*user     = components.lpszUserName;
+	*user_len = components.dwUserNameLength;
+	*pass     = components.lpszPassword;
+	*pass_len = components.dwPasswordLength;
+
+	return 0;
+}
+
+#define SCHEME_HTTP  "http://"
+#define SCHEME_HTTPS "https://"
+
+static int winhttp_stream_connect(winhttp_stream *s)
+{
+	winhttp_subtransport *t = OWNING_SUBTRANSPORT(s);
+	git_buf buf = GIT_BUF_INIT;
+	char *proxy_url = NULL;
+	wchar_t ct[MAX_CONTENT_TYPE_LEN];
+	LPCWSTR types[] = { L"*/*", NULL };
+	BOOL peerdist = FALSE;
+	int error = -1;
+	unsigned long disable_redirects = WINHTTP_DISABLE_REDIRECTS;
+	int default_timeout = TIMEOUT_INFINITE;
+	int default_connect_timeout = DEFAULT_CONNECT_TIMEOUT;
+	size_t i;
+	const git_proxy_options *proxy_opts;
+
+	/* Prepare URL */
+	git_buf_printf(&buf, "%s%s", t->connection_data.path, s->service_url);
+
+	if (git_buf_oom(&buf))
+		return -1;
+
+	/* Convert URL to wide characters */
+	if (git__utf8_to_16_alloc(&s->request_uri, git_buf_cstr(&buf)) < 0) {
+		giterr_set(GITERR_OS, "failed to convert string to wide form");
+		goto on_error;
+	}
+
+	/* Establish request */
+	s->request = WinHttpOpenRequest(
+			t->connection,
+			s->verb,
+			s->request_uri,
+			NULL,
+			WINHTTP_NO_REFERER,
+			types,
+			t->connection_data.use_ssl ? WINHTTP_FLAG_SECURE : 0);
+
+	if (!s->request) {
+		giterr_set(GITERR_OS, "failed to open request");
+		goto on_error;
+	}
+
+	if (!WinHttpSetTimeouts(s->request, default_timeout, default_connect_timeout, default_timeout, default_timeout)) {
+		giterr_set(GITERR_OS, "failed to set timeouts for WinHTTP");
+		goto on_error;
+	}
+
+	proxy_opts = &t->owner->proxy;
+	if (proxy_opts->type == GIT_PROXY_AUTO) {
+		/* Set proxy if necessary */
+		if (git_remote__get_http_proxy(t->owner->owner, !!t->connection_data.use_ssl, &proxy_url) < 0)
+			goto on_error;
+	}
+	else if (proxy_opts->type == GIT_PROXY_SPECIFIED) {
+		proxy_url = git__strdup(proxy_opts->url);
+		GITERR_CHECK_ALLOC(proxy_url);
+	}
+
+	if (proxy_url) {
+		git_buf processed_url = GIT_BUF_INIT;
+		WINHTTP_PROXY_INFO proxy_info;
+		wchar_t *proxy_wide;
+
+		if (!git__prefixcmp(proxy_url, SCHEME_HTTP)) {
+			t->proxy_connection_data.use_ssl = false;
+		} else if (!git__prefixcmp(proxy_url, SCHEME_HTTPS)) {
+			t->proxy_connection_data.use_ssl = true;
+		} else {
+			giterr_set(GITERR_NET, "invalid URL: '%s'", proxy_url);
+			return -1;
+		}
+
+		gitno_connection_data_free_ptrs(&t->proxy_connection_data);
+
+		if ((error = gitno_extract_url_parts(&t->proxy_connection_data.host, &t->proxy_connection_data.port, NULL,
+				&t->proxy_connection_data.user, &t->proxy_connection_data.pass, proxy_url, NULL)) < 0)
+			goto on_error;
+
+		if (t->proxy_connection_data.user && t->proxy_connection_data.pass) {
+			if (t->proxy_cred) {
+				t->proxy_cred->free(t->proxy_cred);
+			}
+
+			if ((error = git_cred_userpass_plaintext_new(&t->proxy_cred, t->proxy_connection_data.user, t->proxy_connection_data.pass)) < 0)
+				goto on_error;
+		}
+
+		if (t->proxy_connection_data.use_ssl)
+			git_buf_PUTS(&processed_url, SCHEME_HTTPS);
+		else
+			git_buf_PUTS(&processed_url, SCHEME_HTTP);
+
+		git_buf_puts(&processed_url, t->proxy_connection_data.host);
+		if (t->proxy_connection_data.port)
+			git_buf_printf(&processed_url, ":%s", t->proxy_connection_data.port);
+
+		if (git_buf_oom(&processed_url)) {
+			error = -1;
+			goto on_error;
+		}
+
+		/* Convert URL to wide characters */
+		error = git__utf8_to_16_alloc(&proxy_wide, processed_url.ptr);
+		git_buf_free(&processed_url);
+		if (error < 0)
+			goto on_error;
+
+		proxy_info.dwAccessType = WINHTTP_ACCESS_TYPE_NAMED_PROXY;
+		proxy_info.lpszProxy = proxy_wide;
+		proxy_info.lpszProxyBypass = NULL;
+
+		if (!WinHttpSetOption(s->request,
+			WINHTTP_OPTION_PROXY,
+			&proxy_info,
+			sizeof(WINHTTP_PROXY_INFO))) {
+			giterr_set(GITERR_OS, "failed to set proxy");
+			git__free(proxy_wide);
+			goto on_error;
+		}
+
+		git__free(proxy_wide);
+
+		if (t->proxy_cred) {
+			if (t->proxy_cred->credtype == GIT_CREDTYPE_USERPASS_PLAINTEXT) {
+				if ((error = apply_userpass_credential_proxy(s->request, t->proxy_cred, t->auth_mechanisms)) < 0)
+					goto on_error;
+			}
+		}
+
+	}
+
+	/* Disable WinHTTP redirects so we can handle them manually. Why, you ask?
+	 * http://social.msdn.microsoft.com/Forums/windowsdesktop/en-US/b2ff8879-ab9f-4218-8f09-16d25dff87ae
+	 */
+	if (!WinHttpSetOption(s->request,
+		WINHTTP_OPTION_DISABLE_FEATURE,
+		&disable_redirects,
+		sizeof(disable_redirects))) {
+			giterr_set(GITERR_OS, "failed to disable redirects");
+			goto on_error;
+	}
+
+	/* Strip unwanted headers (X-P2P-PeerDist, X-P2P-PeerDistEx) that WinHTTP
+	 * adds itself. This option may not be supported by the underlying
+	 * platform, so we do not error-check it */
+	WinHttpSetOption(s->request,
+		WINHTTP_OPTION_PEERDIST_EXTENSION_STATE,
+		&peerdist,
+		sizeof(peerdist));
+
+	/* Send Pragma: no-cache header */
+	if (!WinHttpAddRequestHeaders(s->request, pragma_nocache, (ULONG) -1L, WINHTTP_ADDREQ_FLAG_ADD)) {
+		giterr_set(GITERR_OS, "failed to add a header to the request");
+		goto on_error;
+	}
+
+	if (post_verb == s->verb) {
+		/* Send Content-Type and Accept headers -- only necessary on a POST */
+		git_buf_clear(&buf);
+		if (git_buf_printf(&buf,
+			"Content-Type: application/x-git-%s-request",
+			s->service) < 0)
+			goto on_error;
+
+		if (git__utf8_to_16(ct, MAX_CONTENT_TYPE_LEN, git_buf_cstr(&buf)) < 0) {
+			giterr_set(GITERR_OS, "failed to convert content-type to wide characters");
+			goto on_error;
+		}
+
+		if (!WinHttpAddRequestHeaders(s->request, ct, (ULONG)-1L,
+			WINHTTP_ADDREQ_FLAG_ADD | WINHTTP_ADDREQ_FLAG_REPLACE)) {
+			giterr_set(GITERR_OS, "failed to add a header to the request");
+			goto on_error;
+		}
+
+		git_buf_clear(&buf);
+		if (git_buf_printf(&buf,
+			"Accept: application/x-git-%s-result",
+			s->service) < 0)
+			goto on_error;
+
+		if (git__utf8_to_16(ct, MAX_CONTENT_TYPE_LEN, git_buf_cstr(&buf)) < 0) {
+			giterr_set(GITERR_OS, "failed to convert accept header to wide characters");
+			goto on_error;
+		}
+
+		if (!WinHttpAddRequestHeaders(s->request, ct, (ULONG)-1L,
+			WINHTTP_ADDREQ_FLAG_ADD | WINHTTP_ADDREQ_FLAG_REPLACE)) {
+			giterr_set(GITERR_OS, "failed to add a header to the request");
+			goto on_error;
+		}
+	}
+
+	for (i = 0; i < t->owner->custom_headers.count; i++) {
+		if (t->owner->custom_headers.strings[i]) {
+			git_buf_clear(&buf);
+			git_buf_puts(&buf, t->owner->custom_headers.strings[i]);
+			if (git__utf8_to_16(ct, MAX_CONTENT_TYPE_LEN, git_buf_cstr(&buf)) < 0) {
+				giterr_set(GITERR_OS, "failed to convert custom header to wide characters");
+				goto on_error;
+			}
+
+			if (!WinHttpAddRequestHeaders(s->request, ct, (ULONG)-1L,
+				WINHTTP_ADDREQ_FLAG_ADD | WINHTTP_ADDREQ_FLAG_REPLACE)) {
+				giterr_set(GITERR_OS, "failed to add a header to the request");
+				goto on_error;
+			}
+		}
+	}
+
+	/* If requested, disable certificate validation */
+	if (t->connection_data.use_ssl) {
+		int flags;
+
+		if (t->owner->parent.read_flags(&t->owner->parent, &flags) < 0)
+			goto on_error;
+	}
+
+	/* If we have a credential on the subtransport, apply it to the request */
+	if (t->cred &&
+		t->cred->credtype == GIT_CREDTYPE_USERPASS_PLAINTEXT &&
+		apply_userpass_credential(s->request, t->auth_mechanisms, t->cred) < 0)
+		goto on_error;
+	else if (t->cred &&
+		t->cred->credtype == GIT_CREDTYPE_DEFAULT &&
+		apply_default_credentials(s->request, t->auth_mechanisms) < 0)
+		goto on_error;
+
+	/* If no other credentials have been applied and the URL has username and
+	 * password, use those */
+	if (!t->cred && t->connection_data.user && t->connection_data.pass) {
+		if (!t->url_cred &&
+			git_cred_userpass_plaintext_new(&t->url_cred, t->connection_data.user, t->connection_data.pass) < 0)
+			goto on_error;
+		if (apply_userpass_credential(s->request, GIT_WINHTTP_AUTH_BASIC, t->url_cred) < 0)
+			goto on_error;
+	}
+
+	/* We've done everything up to calling WinHttpSendRequest. */
+
+	error = 0;
+
+on_error:
+	if (error < 0)
+		winhttp_stream_close(s);
+
+	git__free(proxy_url);
+	git_buf_free(&buf);
+	return error;
+}
+
+static int parse_unauthorized_response(
+	HINTERNET request,
+	int *allowed_types,
+	int *allowed_mechanisms)
+{
+	DWORD supported, first, target;
+
+	*allowed_types = 0;
+	*allowed_mechanisms = 0;
+
+	/* WinHttpQueryHeaders() must be called before WinHttpQueryAuthSchemes().
+	 * We can assume this was already done, since we know we are unauthorized.
+	 */
+	if (!WinHttpQueryAuthSchemes(request, &supported, &first, &target)) {
+		giterr_set(GITERR_OS, "failed to parse supported auth schemes");
+		return -1;
+	}
+
+	if (WINHTTP_AUTH_SCHEME_NTLM & supported) {
+		*allowed_types |= GIT_CREDTYPE_USERPASS_PLAINTEXT;
+		*allowed_types |= GIT_CREDTYPE_DEFAULT;
+		*allowed_mechanisms |= GIT_WINHTTP_AUTH_NTLM;
+	}
+
+	if (WINHTTP_AUTH_SCHEME_NEGOTIATE & supported) {
+		*allowed_types |= GIT_CREDTYPE_DEFAULT;
+		*allowed_mechanisms |= GIT_WINHTTP_AUTH_NEGOTIATE;
+	}
+
+	if (WINHTTP_AUTH_SCHEME_BASIC & supported) {
+		*allowed_types |= GIT_CREDTYPE_USERPASS_PLAINTEXT;
+		*allowed_mechanisms |= GIT_WINHTTP_AUTH_BASIC;
+	}
+
+	if (WINHTTP_AUTH_SCHEME_DIGEST & supported) {
+		*allowed_types |= GIT_CREDTYPE_USERPASS_PLAINTEXT;
+		*allowed_mechanisms |= GIT_WINHTTP_AUTH_DIGEST;
+	}
+
+	return 0;
+}
+
+static int write_chunk(HINTERNET request, const char *buffer, size_t len)
+{
+	DWORD bytes_written;
+	git_buf buf = GIT_BUF_INIT;
+
+	/* Chunk header */
+	git_buf_printf(&buf, "%X\r\n", len);
+
+	if (git_buf_oom(&buf))
+		return -1;
+
+	if (!WinHttpWriteData(request,
+		git_buf_cstr(&buf),	(DWORD)git_buf_len(&buf),
+		&bytes_written)) {
+		git_buf_free(&buf);
+		giterr_set(GITERR_OS, "failed to write chunk header");
+		return -1;
+	}
+
+	git_buf_free(&buf);
+
+	/* Chunk body */
+	if (!WinHttpWriteData(request,
+		buffer, (DWORD)len,
+		&bytes_written)) {
+		giterr_set(GITERR_OS, "failed to write chunk");
+		return -1;
+	}
+
+	/* Chunk footer */
+	if (!WinHttpWriteData(request,
+		"\r\n", 2,
+		&bytes_written)) {
+		giterr_set(GITERR_OS, "failed to write chunk footer");
+		return -1;
+	}
+
+	return 0;
+}
+
+static int winhttp_close_connection(winhttp_subtransport *t)
+{
+	int ret = 0;
+
+	if (t->connection) {
+		if (!WinHttpCloseHandle(t->connection)) {
+			giterr_set(GITERR_OS, "unable to close connection");
+			ret = -1;
+		}
+
+		t->connection = NULL;
+	}
+
+	if (t->session) {
+		if (!WinHttpCloseHandle(t->session)) {
+			giterr_set(GITERR_OS, "unable to close session");
+			ret = -1;
+		}
+
+		t->session = NULL;
+	}
+
+	return ret;
+}
+
+static void CALLBACK winhttp_status(
+	HINTERNET connection,
+	DWORD_PTR ctx,
+	DWORD code,
+	LPVOID info,
+	DWORD info_len)
+{
+	DWORD status;
+
+	if (code != WINHTTP_CALLBACK_STATUS_SECURE_FAILURE)
+		return;
+
+	status = *((DWORD *)info);
+
+	if ((status & WINHTTP_CALLBACK_STATUS_FLAG_CERT_CN_INVALID))
+		giterr_set(GITERR_NET, "SSL certificate issued for different common name");
+	else if ((status & WINHTTP_CALLBACK_STATUS_FLAG_CERT_DATE_INVALID))
+		giterr_set(GITERR_NET, "SSL certificate has expired");
+	else if ((status & WINHTTP_CALLBACK_STATUS_FLAG_INVALID_CA))
+		giterr_set(GITERR_NET, "SSL certificate signed by unknown CA");
+	else if ((status & WINHTTP_CALLBACK_STATUS_FLAG_INVALID_CERT))
+		giterr_set(GITERR_NET, "SSL certificate is invalid");
+	else if ((status & WINHTTP_CALLBACK_STATUS_FLAG_CERT_REV_FAILED))
+		giterr_set(GITERR_NET, "certificate revocation check failed");
+	else if ((status & WINHTTP_CALLBACK_STATUS_FLAG_CERT_REVOKED))
+		giterr_set(GITERR_NET, "SSL certificate was revoked");
+	else if ((status & WINHTTP_CALLBACK_STATUS_FLAG_SECURITY_CHANNEL_ERROR))
+		giterr_set(GITERR_NET, "security libraries could not be loaded");
+	else
+		giterr_set(GITERR_NET, "unknown security error %d", status);
+}
+
+static int winhttp_connect(
+	winhttp_subtransport *t)
+{
+	wchar_t *wide_host;
+	int32_t port;
+	wchar_t *wide_ua;
+	git_buf ua = GIT_BUF_INIT;
+	int error = -1;
+	int default_timeout = TIMEOUT_INFINITE;
+	int default_connect_timeout = DEFAULT_CONNECT_TIMEOUT;
+	DWORD protocols =
+		WINHTTP_FLAG_SECURE_PROTOCOL_TLS1 |
+		WINHTTP_FLAG_SECURE_PROTOCOL_TLS1_1 |
+		WINHTTP_FLAG_SECURE_PROTOCOL_TLS1_2;
+
+	t->session = NULL;
+	t->connection = NULL;
+
+	/* Prepare port */
+	if (git__strtol32(&port, t->connection_data.port, NULL, 10) < 0)
+		return -1;
+
+	/* Prepare host */
+	if (git__utf8_to_16_alloc(&wide_host, t->connection_data.host) < 0) {
+		giterr_set(GITERR_OS, "unable to convert host to wide characters");
+		return -1;
+	}
+
+
+	if ((error = git_http__user_agent(&ua)) < 0) {
+		git__free(wide_host);
+		return error;
+	}
+
+	if (git__utf8_to_16_alloc(&wide_ua, git_buf_cstr(&ua)) < 0) {
+		giterr_set(GITERR_OS, "unable to convert host to wide characters");
+		git__free(wide_host);
+		git_buf_free(&ua);
+		return -1;
+	}
+
+	git_buf_free(&ua);
+
+	/* Establish session */
+	t->session = WinHttpOpen(
+		wide_ua,
+		WINHTTP_ACCESS_TYPE_DEFAULT_PROXY,
+		WINHTTP_NO_PROXY_NAME,
+		WINHTTP_NO_PROXY_BYPASS,
+		0);
+
+	if (!t->session) {
+		giterr_set(GITERR_OS, "failed to init WinHTTP");
+		goto on_error;
+	}
+
+	/*
+	 * Do a best-effort attempt to enable TLS 1.2 but allow this to
+	 * fail; if TLS 1.2 support is not available for some reason,
+	 * ignore the failure (it will keep the default protocols).
+	 */
+	WinHttpSetOption(t->session,
+		WINHTTP_OPTION_SECURE_PROTOCOLS,
+		&protocols,
+		sizeof(protocols));
+
+	if (!WinHttpSetTimeouts(t->session, default_timeout, default_connect_timeout, default_timeout, default_timeout)) {
+		giterr_set(GITERR_OS, "failed to set timeouts for WinHTTP");
+		goto on_error;
+	}
+
+
+	/* Establish connection */
+	t->connection = WinHttpConnect(
+		t->session,
+		wide_host,
+		(INTERNET_PORT) port,
+		0);
+
+	if (!t->connection) {
+		giterr_set(GITERR_OS, "failed to connect to host");
+		goto on_error;
+	}
+
+	if (WinHttpSetStatusCallback(t->connection, winhttp_status, WINHTTP_CALLBACK_FLAG_SECURE_FAILURE, 0) == WINHTTP_INVALID_STATUS_CALLBACK) {
+		giterr_set(GITERR_OS, "failed to set status callback");
+		goto on_error;
+	}
+
+	error = 0;
+
+on_error:
+	if (error < 0)
+		winhttp_close_connection(t);
+
+	git__free(wide_host);
+	git__free(wide_ua);
+
+	return error;
+}
+
+static int do_send_request(winhttp_stream *s, size_t len, int ignore_length)
+{
+	if (ignore_length) {
+		if (!WinHttpSendRequest(s->request,
+			WINHTTP_NO_ADDITIONAL_HEADERS, 0,
+			WINHTTP_NO_REQUEST_DATA, 0,
+			WINHTTP_IGNORE_REQUEST_TOTAL_LENGTH, 0)) {
+			return -1;
+		}
+	} else {
+		if (!WinHttpSendRequest(s->request,
+			WINHTTP_NO_ADDITIONAL_HEADERS, 0,
+			WINHTTP_NO_REQUEST_DATA, 0,
+			len, 0)) {
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+static int send_request(winhttp_stream *s, size_t len, int ignore_length)
+{
+	int request_failed = 0, cert_valid = 1, error = 0;
+	DWORD ignore_flags;
+
+	giterr_clear();
+	if ((error = do_send_request(s, len, ignore_length)) < 0) {
+		if (GetLastError() != ERROR_WINHTTP_SECURE_FAILURE) {
+			giterr_set(GITERR_OS, "failed to send request");
+			return -1;
+		}
+
+		request_failed = 1;
+		cert_valid = 0;
+	}
+
+	giterr_clear();
+	if ((error = certificate_check(s, cert_valid)) < 0) {
+		if (!giterr_last())
+			giterr_set(GITERR_OS, "user cancelled certificate check");
+
+		return error;
+	}
+
+	/* if neither the request nor the certificate check returned errors, we're done */
+	if (!request_failed)
+		return 0;
+
+	ignore_flags = no_check_cert_flags;
+
+	if (!WinHttpSetOption(s->request, WINHTTP_OPTION_SECURITY_FLAGS, &ignore_flags, sizeof(ignore_flags))) {
+		giterr_set(GITERR_OS, "failed to set security options");
+		return -1;
+	}
+
+	if ((error = do_send_request(s, len, ignore_length)) < 0)
+		giterr_set(GITERR_OS, "failed to send request with unchecked certificate");
+
+	return error;
+}
+
+static int winhttp_stream_read(
+	git_smart_subtransport_stream *stream,
+	char *buffer,
+	size_t buf_size,
+	size_t *bytes_read)
+{
+	winhttp_stream *s = (winhttp_stream *)stream;
+	winhttp_subtransport *t = OWNING_SUBTRANSPORT(s);
+	DWORD dw_bytes_read;
+	char replay_count = 0;
+	int error;
+
+replay:
+	/* Enforce a reasonable cap on the number of replays */
+	if (++replay_count >= 7) {
+		giterr_set(GITERR_NET, "too many redirects or authentication replays");
+		return -1;
+	}
+
+	/* Connect if necessary */
+	if (!s->request && winhttp_stream_connect(s) < 0)
+		return -1;
+
+	if (!s->received_response) {
+		DWORD status_code, status_code_length, content_type_length, bytes_written;
+		char expected_content_type_8[MAX_CONTENT_TYPE_LEN];
+		wchar_t expected_content_type[MAX_CONTENT_TYPE_LEN], content_type[MAX_CONTENT_TYPE_LEN];
+
+		if (!s->sent_request) {
+
+			if ((error = send_request(s, s->post_body_len, 0)) < 0)
+				return error;
+
+			s->sent_request = 1;
+		}
+
+		if (s->chunked) {
+			assert(s->verb == post_verb);
+
+			/* Flush, if necessary */
+			if (s->chunk_buffer_len > 0 &&
+				write_chunk(s->request, s->chunk_buffer, s->chunk_buffer_len) < 0)
+				return -1;
+
+			s->chunk_buffer_len = 0;
+
+			/* Write the final chunk. */
+			if (!WinHttpWriteData(s->request,
+				"0\r\n\r\n", 5,
+				&bytes_written)) {
+				giterr_set(GITERR_OS, "failed to write final chunk");
+				return -1;
+			}
+		}
+		else if (s->post_body) {
+			char *buffer;
+			DWORD len = s->post_body_len, bytes_read;
+
+			if (INVALID_SET_FILE_POINTER == SetFilePointer(s->post_body,
+					0, 0, FILE_BEGIN) &&
+				NO_ERROR != GetLastError()) {
+				giterr_set(GITERR_OS, "failed to reset file pointer");
+				return -1;
+			}
+
+			buffer = git__malloc(CACHED_POST_BODY_BUF_SIZE);
+
+			while (len > 0) {
+				DWORD bytes_written;
+
+				if (!ReadFile(s->post_body, buffer,
+					min(CACHED_POST_BODY_BUF_SIZE, len),
+					&bytes_read, NULL) ||
+					!bytes_read) {
+					git__free(buffer);
+					giterr_set(GITERR_OS, "failed to read from temp file");
+					return -1;
+				}
+
+				if (!WinHttpWriteData(s->request, buffer,
+					bytes_read, &bytes_written)) {
+					git__free(buffer);
+					giterr_set(GITERR_OS, "failed to write data");
+					return -1;
+				}
+
+				len -= bytes_read;
+				assert(bytes_read == bytes_written);
+			}
+
+			git__free(buffer);
+
+			/* Eagerly close the temp file */
+			CloseHandle(s->post_body);
+			s->post_body = NULL;
+		}
+
+		if (!WinHttpReceiveResponse(s->request, 0)) {
+			giterr_set(GITERR_OS, "failed to receive response");
+			return -1;
+		}
+
+		/* Verify that we got a 200 back */
+		status_code_length = sizeof(status_code);
+
+		if (!WinHttpQueryHeaders(s->request,
+			WINHTTP_QUERY_STATUS_CODE | WINHTTP_QUERY_FLAG_NUMBER,
+			WINHTTP_HEADER_NAME_BY_INDEX,
+			&status_code, &status_code_length,
+			WINHTTP_NO_HEADER_INDEX)) {
+				giterr_set(GITERR_OS, "failed to retrieve status code");
+				return -1;
+		}
+
+		/* The implementation of WinHTTP prior to Windows 7 will not
+		 * redirect to an identical URI. Some Git hosters use self-redirects
+		 * as part of their DoS mitigation strategy. Check first to see if we
+		 * have a redirect status code, and that we haven't already streamed
+		 * a post body. (We can't replay a streamed POST.) */
+		if (!s->chunked &&
+			(HTTP_STATUS_MOVED == status_code ||
+			 HTTP_STATUS_REDIRECT == status_code ||
+			 (HTTP_STATUS_REDIRECT_METHOD == status_code &&
+			  get_verb == s->verb) ||
+			 HTTP_STATUS_REDIRECT_KEEP_VERB == status_code)) {
+
+			/* Check for Windows 7. This workaround is only necessary on
+			 * Windows Vista and earlier. Windows 7 is version 6.1. */
+			wchar_t *location;
+			DWORD location_length;
+			char *location8;
+
+			/* OK, fetch the Location header from the redirect. */
+			if (WinHttpQueryHeaders(s->request,
+				WINHTTP_QUERY_LOCATION,
+				WINHTTP_HEADER_NAME_BY_INDEX,
+				WINHTTP_NO_OUTPUT_BUFFER,
+				&location_length,
+				WINHTTP_NO_HEADER_INDEX) ||
+				GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
+				giterr_set(GITERR_OS, "failed to read Location header");
+				return -1;
+			}
+
+			location = git__malloc(location_length);
+			GITERR_CHECK_ALLOC(location);
+
+			if (!WinHttpQueryHeaders(s->request,
+				WINHTTP_QUERY_LOCATION,
+				WINHTTP_HEADER_NAME_BY_INDEX,
+				location,
+				&location_length,
+				WINHTTP_NO_HEADER_INDEX)) {
+				giterr_set(GITERR_OS, "failed to read Location header");
+				git__free(location);
+				return -1;
+			}
+
+			/* Convert the Location header to UTF-8 */
+			if (git__utf16_to_8_alloc(&location8, location) < 0) {
+				giterr_set(GITERR_OS, "failed to convert Location header to UTF-8");
+				git__free(location);
+				return -1;
+			}
+
+			git__free(location);
+
+			/* Replay the request */
+			winhttp_stream_close(s);
+
+			if (!git__prefixcmp_icase(location8, prefix_https)) {
+				/* Upgrade to secure connection; disconnect and start over */
+				if (gitno_connection_data_from_url(&t->connection_data, location8, s->service_url) < 0) {
+					git__free(location8);
+					return -1;
+				}
+
+				winhttp_close_connection(t);
+
+				if (winhttp_connect(t) < 0)
+					return -1;
+			}
+
+			git__free(location8);
+			goto replay;
+		}
+
+		/* Handle proxy authentication failures */
+		if (status_code == HTTP_STATUS_PROXY_AUTH_REQ) {
+			int allowed_types;
+
+			if (parse_unauthorized_response(s->request, &allowed_types, &t->auth_mechanisms) < 0)
+				return -1;
+
+			/* TODO: extract the username from the url, no payload? */
+			if (t->owner->proxy.credentials) {
+				int cred_error = 1;
+				cred_error = t->owner->proxy.credentials(&t->proxy_cred, t->owner->proxy.url, NULL, allowed_types, t->owner->proxy.payload);
+
+				if (cred_error < 0)
+					return cred_error;
+			}
+
+			winhttp_stream_close(s);
+			goto replay;
+		}
+
+		/* Handle authentication failures */
+		if (HTTP_STATUS_DENIED == status_code && get_verb == s->verb) {
+			int allowed_types;
+
+			if (parse_unauthorized_response(s->request, &allowed_types, &t->auth_mechanisms) < 0)
+				return -1;
+
+			if (allowed_types) {
+				int cred_error = 1;
+
+				git_cred_free(t->cred);
+				t->cred = NULL;
+				/* Start with the user-supplied credential callback, if present */
+				if (t->owner->cred_acquire_cb) {
+					cred_error = t->owner->cred_acquire_cb(&t->cred, t->owner->url,
+						t->connection_data.user, allowed_types,	t->owner->cred_acquire_payload);
+
+					/* Treat GIT_PASSTHROUGH as though git_cred_acquire_cb isn't set */
+					if (cred_error == GIT_PASSTHROUGH)
+						cred_error = 1;
+					else if (cred_error < 0)
+						return cred_error;
+				}
+
+				/* Invoke the fallback credentials acquisition callback if necessary */
+				if (cred_error > 0) {
+					cred_error = fallback_cred_acquire_cb(&t->cred, t->owner->url,
+						t->connection_data.user, allowed_types, NULL);
+
+					if (cred_error < 0)
+						return cred_error;
+				}
+
+				if (!cred_error) {
+					assert(t->cred);
+
+					winhttp_stream_close(s);
+
+					/* Successfully acquired a credential */
+					goto replay;
+				}
+			}
+		}
+
+		if (HTTP_STATUS_OK != status_code) {
+			giterr_set(GITERR_NET, "request failed with status code: %d", status_code);
+			return -1;
+		}
+
+		/* Verify that we got the correct content-type back */
+		if (post_verb == s->verb)
+			p_snprintf(expected_content_type_8, MAX_CONTENT_TYPE_LEN, "application/x-git-%s-result", s->service);
+		else
+			p_snprintf(expected_content_type_8, MAX_CONTENT_TYPE_LEN, "application/x-git-%s-advertisement", s->service);
+
+		if (git__utf8_to_16(expected_content_type, MAX_CONTENT_TYPE_LEN, expected_content_type_8) < 0) {
+			giterr_set(GITERR_OS, "failed to convert expected content-type to wide characters");
+			return -1;
+		}
+
+		content_type_length = sizeof(content_type);
+
+		if (!WinHttpQueryHeaders(s->request,
+			WINHTTP_QUERY_CONTENT_TYPE,
+			WINHTTP_HEADER_NAME_BY_INDEX,
+			&content_type, &content_type_length,
+			WINHTTP_NO_HEADER_INDEX)) {
+				giterr_set(GITERR_OS, "failed to retrieve response content-type");
+				return -1;
+		}
+
+		if (wcscmp(expected_content_type, content_type)) {
+			giterr_set(GITERR_NET, "received unexpected content-type");
+			return -1;
+		}
+
+		s->received_response = 1;
+	}
+
+	if (!WinHttpReadData(s->request,
+		(LPVOID)buffer,
+		(DWORD)buf_size,
+		&dw_bytes_read))
+	{
+		giterr_set(GITERR_OS, "failed to read data");
+		return -1;
+	}
+
+	*bytes_read = dw_bytes_read;
+
+	return 0;
+}
+
+static int winhttp_stream_write_single(
+	git_smart_subtransport_stream *stream,
+	const char *buffer,
+	size_t len)
+{
+	winhttp_stream *s = (winhttp_stream *)stream;
+	DWORD bytes_written;
+	int error;
+
+	if (!s->request && winhttp_stream_connect(s) < 0)
+		return -1;
+
+	/* This implementation of write permits only a single call. */
+	if (s->sent_request) {
+		giterr_set(GITERR_NET, "subtransport configured for only one write");
+		return -1;
+	}
+
+	if ((error = send_request(s, len, 0)) < 0)
+		return error;
+
+	s->sent_request = 1;
+
+	if (!WinHttpWriteData(s->request,
+			(LPCVOID)buffer,
+			(DWORD)len,
+			&bytes_written)) {
+		giterr_set(GITERR_OS, "failed to write data");
+		return -1;
+	}
+
+	assert((DWORD)len == bytes_written);
+
+	return 0;
+}
+
+static int put_uuid_string(LPWSTR buffer, size_t buffer_len_cch)
+{
+	UUID uuid;
+	RPC_STATUS status = UuidCreate(&uuid);
+	int result;
+
+	if (RPC_S_OK != status &&
+		RPC_S_UUID_LOCAL_ONLY != status &&
+		RPC_S_UUID_NO_ADDRESS != status) {
+		giterr_set(GITERR_NET, "unable to generate name for temp file");
+		return -1;
+	}
+
+	if (buffer_len_cch < UUID_LENGTH_CCH + 1) {
+		giterr_set(GITERR_NET, "buffer too small for name of temp file");
+		return -1;
+	}
+
+#if !defined(__MINGW32__) || defined(MINGW_HAS_SECURE_API)
+	result = swprintf_s(buffer, buffer_len_cch,
+#else
+	result = wsprintfW(buffer,
+#endif
+		L"%08x%04x%04x%02x%02x%02x%02x%02x%02x%02x%02x",
+		uuid.Data1, uuid.Data2, uuid.Data3,
+		uuid.Data4[0], uuid.Data4[1], uuid.Data4[2], uuid.Data4[3],
+		uuid.Data4[4], uuid.Data4[5], uuid.Data4[6], uuid.Data4[7]);
+
+	if (result < UUID_LENGTH_CCH) {
+		giterr_set(GITERR_OS, "unable to generate name for temp file");
+		return -1;
+	}
+
+	return 0;
+}
+
+static int get_temp_file(LPWSTR buffer, DWORD buffer_len_cch)
+{
+	size_t len;
+
+	if (!GetTempPathW(buffer_len_cch, buffer)) {
+		giterr_set(GITERR_OS, "failed to get temp path");
+		return -1;
+	}
+
+	len = wcslen(buffer);
+
+	if (buffer[len - 1] != '\\' && len < buffer_len_cch)
+		buffer[len++] = '\\';
+
+	if (put_uuid_string(&buffer[len], (size_t)buffer_len_cch - len) < 0)
+		return -1;
+
+	return 0;
+}
+
+static int winhttp_stream_write_buffered(
+	git_smart_subtransport_stream *stream,
+	const char *buffer,
+	size_t len)
+{
+	winhttp_stream *s = (winhttp_stream *)stream;
+	DWORD bytes_written;
+
+	if (!s->request && winhttp_stream_connect(s) < 0)
+		return -1;
+
+	/* Buffer the payload, using a temporary file so we delegate
+	 * memory management of the data to the operating system. */
+	if (!s->post_body) {
+		wchar_t temp_path[MAX_PATH + 1];
+
+		if (get_temp_file(temp_path, MAX_PATH + 1) < 0)
+			return -1;
+
+		s->post_body = CreateFileW(temp_path,
+			GENERIC_READ | GENERIC_WRITE,
+			FILE_SHARE_DELETE, NULL,
+			CREATE_NEW,
+			FILE_ATTRIBUTE_TEMPORARY | FILE_FLAG_DELETE_ON_CLOSE | FILE_FLAG_SEQUENTIAL_SCAN,
+			NULL);
+
+		if (INVALID_HANDLE_VALUE == s->post_body) {
+			s->post_body = NULL;
+			giterr_set(GITERR_OS, "failed to create temporary file");
+			return -1;
+		}
+	}
+
+	if (!WriteFile(s->post_body, buffer, (DWORD)len, &bytes_written, NULL)) {
+		giterr_set(GITERR_OS, "failed to write to temporary file");
+		return -1;
+	}
+
+	assert((DWORD)len == bytes_written);
+
+	s->post_body_len += bytes_written;
+
+	return 0;
+}
+
+static int winhttp_stream_write_chunked(
+	git_smart_subtransport_stream *stream,
+	const char *buffer,
+	size_t len)
+{
+	winhttp_stream *s = (winhttp_stream *)stream;
+	int error;
+
+	if (!s->request && winhttp_stream_connect(s) < 0)
+		return -1;
+
+	if (!s->sent_request) {
+		/* Send Transfer-Encoding: chunked header */
+		if (!WinHttpAddRequestHeaders(s->request,
+			transfer_encoding, (ULONG) -1L,
+			WINHTTP_ADDREQ_FLAG_ADD)) {
+			giterr_set(GITERR_OS, "failed to add a header to the request");
+			return -1;
+		}
+
+		if ((error = send_request(s, 0, 1)) < 0)
+			return error;
+
+		s->sent_request = 1;
+	}
+
+	if (len > CACHED_POST_BODY_BUF_SIZE) {
+		/* Flush, if necessary */
+		if (s->chunk_buffer_len > 0) {
+			if (write_chunk(s->request, s->chunk_buffer, s->chunk_buffer_len) < 0)
+				return -1;
+
+			s->chunk_buffer_len = 0;
+		}
+
+		/* Write chunk directly */
+		if (write_chunk(s->request, buffer, len) < 0)
+			return -1;
+	}
+	else {
+		/* Append as much to the buffer as we can */
+		int count = (int)min(CACHED_POST_BODY_BUF_SIZE - s->chunk_buffer_len, len);
+
+		if (!s->chunk_buffer)
+			s->chunk_buffer = git__malloc(CACHED_POST_BODY_BUF_SIZE);
+
+		memcpy(s->chunk_buffer + s->chunk_buffer_len, buffer, count);
+		s->chunk_buffer_len += count;
+		buffer += count;
+		len -= count;
+
+		/* Is the buffer full? If so, then flush */
+		if (CACHED_POST_BODY_BUF_SIZE == s->chunk_buffer_len) {
+			if (write_chunk(s->request, s->chunk_buffer, s->chunk_buffer_len) < 0)
+				return -1;
+
+			s->chunk_buffer_len = 0;
+
+			/* Is there any remaining data from the source? */
+			if (len > 0) {
+				memcpy(s->chunk_buffer, buffer, len);
+				s->chunk_buffer_len = (unsigned int)len;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static void winhttp_stream_free(git_smart_subtransport_stream *stream)
+{
+	winhttp_stream *s = (winhttp_stream *)stream;
+
+	winhttp_stream_close(s);
+	git__free(s);
+}
+
+static int winhttp_stream_alloc(winhttp_subtransport *t, winhttp_stream **stream)
+{
+	winhttp_stream *s;
+
+	if (!stream)
+		return -1;
+
+	s = git__calloc(1, sizeof(winhttp_stream));
+	GITERR_CHECK_ALLOC(s);
+
+	s->parent.subtransport = &t->parent;
+	s->parent.read = winhttp_stream_read;
+	s->parent.write = winhttp_stream_write_single;
+	s->parent.free = winhttp_stream_free;
+
+	*stream = s;
+
+	return 0;
+}
+
+static int winhttp_uploadpack_ls(
+	winhttp_subtransport *t,
+	winhttp_stream *s)
+{
+	GIT_UNUSED(t);
+
+	s->service = upload_pack_service;
+	s->service_url = upload_pack_ls_service_url;
+	s->verb = get_verb;
+
+	return 0;
+}
+
+static int winhttp_uploadpack(
+	winhttp_subtransport *t,
+	winhttp_stream *s)
+{
+	GIT_UNUSED(t);
+
+	s->service = upload_pack_service;
+	s->service_url = upload_pack_service_url;
+	s->verb = post_verb;
+
+	return 0;
+}
+
+static int winhttp_receivepack_ls(
+	winhttp_subtransport *t,
+	winhttp_stream *s)
+{
+	GIT_UNUSED(t);
+
+	s->service = receive_pack_service;
+	s->service_url = receive_pack_ls_service_url;
+	s->verb = get_verb;
+
+	return 0;
+}
+
+static int winhttp_receivepack(
+	winhttp_subtransport *t,
+	winhttp_stream *s)
+{
+	GIT_UNUSED(t);
+
+	/* WinHTTP only supports Transfer-Encoding: chunked
+	 * on Windows Vista (NT 6.0) and higher. */
+	s->chunked = git_has_win32_version(6, 0, 0);
+
+	if (s->chunked)
+		s->parent.write = winhttp_stream_write_chunked;
+	else
+		s->parent.write = winhttp_stream_write_buffered;
+
+	s->service = receive_pack_service;
+	s->service_url = receive_pack_service_url;
+	s->verb = post_verb;
+
+	return 0;
+}
+
+static int winhttp_action(
+	git_smart_subtransport_stream **stream,
+	git_smart_subtransport *subtransport,
+	const char *url,
+	git_smart_service_t action)
+{
+	winhttp_subtransport *t = (winhttp_subtransport *)subtransport;
+	winhttp_stream *s;
+	int ret = -1;
+
+	if (!t->connection)
+		if ((ret = gitno_connection_data_from_url(&t->connection_data, url, NULL)) < 0 ||
+			 (ret = winhttp_connect(t)) < 0)
+			return ret;
+
+	if (winhttp_stream_alloc(t, &s) < 0)
+		return -1;
+
+	if (!stream)
+		return -1;
+
+	switch (action)
+	{
+		case GIT_SERVICE_UPLOADPACK_LS:
+			ret = winhttp_uploadpack_ls(t, s);
+			break;
+
+		case GIT_SERVICE_UPLOADPACK:
+			ret = winhttp_uploadpack(t, s);
+			break;
+
+		case GIT_SERVICE_RECEIVEPACK_LS:
+			ret = winhttp_receivepack_ls(t, s);
+			break;
+
+		case GIT_SERVICE_RECEIVEPACK:
+			ret = winhttp_receivepack(t, s);
+			break;
+
+		default:
+			assert(0);
+	}
+
+	if (!ret)
+		*stream = &s->parent;
+
+	return ret;
+}
+
+static int winhttp_close(git_smart_subtransport *subtransport)
+{
+	winhttp_subtransport *t = (winhttp_subtransport *)subtransport;
+
+	gitno_connection_data_free_ptrs(&t->connection_data);
+	memset(&t->connection_data, 0x0, sizeof(gitno_connection_data));
+	gitno_connection_data_free_ptrs(&t->proxy_connection_data);
+	memset(&t->proxy_connection_data, 0x0, sizeof(gitno_connection_data));
+
+	if (t->cred) {
+		t->cred->free(t->cred);
+		t->cred = NULL;
+	}
+
+	if (t->proxy_cred) {
+		t->proxy_cred->free(t->proxy_cred);
+		t->proxy_cred = NULL;
+	}
+
+	if (t->url_cred) {
+		t->url_cred->free(t->url_cred);
+		t->url_cred = NULL;
+	}
+
+	return winhttp_close_connection(t);
+}
+
+static void winhttp_free(git_smart_subtransport *subtransport)
+{
+	winhttp_subtransport *t = (winhttp_subtransport *)subtransport;
+
+	winhttp_close(subtransport);
+
+	git__free(t);
+}
+
+int git_smart_subtransport_http(git_smart_subtransport **out, git_transport *owner, void *param)
+{
+	winhttp_subtransport *t;
+
+	GIT_UNUSED(param);
+
+	if (!out)
+		return -1;
+
+	t = git__calloc(1, sizeof(winhttp_subtransport));
+	GITERR_CHECK_ALLOC(t);
+
+	t->owner = (transport_smart *)owner;
+	t->parent.action = winhttp_action;
+	t->parent.close = winhttp_close;
+	t->parent.free = winhttp_free;
+
+	*out = (git_smart_subtransport *) t;
+	return 0;
+}
+
+#endif /* GIT_WINHTTP */

vendor/libgit2-sys/libgit2/src/tree-cache.c

diff --git a/vendor/libgit2-sys/libgit2/src/tree-cache.c b/vendor/libgit2-sys/libgit2/src/tree-cache.c
new file mode 100644
index 0000000..b331d22
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/tree-cache.c
@@ -0,0 +1,270 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "tree-cache.h"
+
+#include "pool.h"
+#include "tree.h"
+
+static git_tree_cache *find_child(
+	const git_tree_cache *tree, const char *path, const char *end)
+{
+	size_t i, dirlen = end ? (size_t)(end - path) : strlen(path);
+
+	for (i = 0; i < tree->children_count; ++i) {
+		git_tree_cache *child = tree->children[i];
+
+		if (child->namelen == dirlen && !memcmp(path, child->name, dirlen))
+			return child;
+	}
+
+	return NULL;
+}
+
+void git_tree_cache_invalidate_path(git_tree_cache *tree, const char *path)
+{
+	const char *ptr = path, *end;
+
+	if (tree == NULL)
+		return;
+
+	tree->entry_count = -1;
+
+	while (ptr != NULL) {
+		end = strchr(ptr, '/');
+
+		if (end == NULL) /* End of path */
+			break;
+
+		tree = find_child(tree, ptr, end);
+		if (tree == NULL) /* We don't have that tree */
+			return;
+
+		tree->entry_count = -1;
+		ptr = end + 1;
+	}
+}
+
+const git_tree_cache *git_tree_cache_get(const git_tree_cache *tree, const char *path)
+{
+	const char *ptr = path, *end;
+
+	if (tree == NULL) {
+		return NULL;
+	}
+
+	while (1) {
+		end = strchr(ptr, '/');
+
+		tree = find_child(tree, ptr, end);
+		if (tree == NULL) /* Can't find it */
+			return NULL;
+
+		if (end == NULL || *end + 1 == '\0')
+			return tree;
+
+		ptr = end + 1;
+	}
+}
+
+static int read_tree_internal(git_tree_cache **out,
+			      const char **buffer_in, const char *buffer_end,
+			      git_pool *pool)
+{
+	git_tree_cache *tree = NULL;
+	const char *name_start, *buffer;
+	int count;
+
+	buffer = name_start = *buffer_in;
+
+	if ((buffer = memchr(buffer, '\0', buffer_end - buffer)) == NULL)
+		goto corrupted;
+
+	if (++buffer >= buffer_end)
+		goto corrupted;
+
+	if (git_tree_cache_new(&tree, name_start, pool) < 0)
+		return -1;
+
+	/* Blank-terminated ASCII decimal number of entries in this tree */
+	if (git__strtol32(&count, buffer, &buffer, 10) < 0)
+		goto corrupted;
+
+	tree->entry_count = count;
+
+	if (*buffer != ' ' || ++buffer >= buffer_end)
+		goto corrupted;
+
+	 /* Number of children of the tree, newline-terminated */
+	if (git__strtol32(&count, buffer, &buffer, 10) < 0 || count < 0)
+		goto corrupted;
+
+	tree->children_count = count;
+
+	if (*buffer != '\n' || ++buffer > buffer_end)
+		goto corrupted;
+
+	/* The SHA1 is only there if it's not invalidated */
+	if (tree->entry_count >= 0) {
+		/* 160-bit SHA-1 for this tree and it's children */
+		if (buffer + GIT_OID_RAWSZ > buffer_end)
+			goto corrupted;
+
+		git_oid_fromraw(&tree->oid, (const unsigned char *)buffer);
+		buffer += GIT_OID_RAWSZ;
+	}
+
+	/* Parse children: */
+	if (tree->children_count > 0) {
+		unsigned int i;
+
+		tree->children = git_pool_malloc(pool, tree->children_count * sizeof(git_tree_cache *));
+		GITERR_CHECK_ALLOC(tree->children);
+
+		memset(tree->children, 0x0, tree->children_count * sizeof(git_tree_cache *));
+
+		for (i = 0; i < tree->children_count; ++i) {
+			if (read_tree_internal(&tree->children[i], &buffer, buffer_end, pool) < 0)
+				goto corrupted;
+		}
+	}
+
+	*buffer_in = buffer;
+	*out = tree;
+	return 0;
+
+ corrupted:
+	giterr_set(GITERR_INDEX, "corrupted TREE extension in index");
+	return -1;
+}
+
+int git_tree_cache_read(git_tree_cache **tree, const char *buffer, size_t buffer_size, git_pool *pool)
+{
+	const char *buffer_end = buffer + buffer_size;
+
+	if (read_tree_internal(tree, &buffer, buffer_end, pool) < 0)
+		return -1;
+
+	if (buffer < buffer_end) {
+		giterr_set(GITERR_INDEX, "corrupted TREE extension in index (unexpected trailing data)");
+		return -1;
+	}
+
+	return 0;
+}
+
+static int read_tree_recursive(git_tree_cache *cache, const git_tree *tree, git_pool *pool)
+{
+	git_repository *repo;
+	size_t i, j, nentries, ntrees;
+	int error;
+
+	repo = git_tree_owner(tree);
+
+	git_oid_cpy(&cache->oid, git_tree_id(tree));
+	nentries = git_tree_entrycount(tree);
+
+	/*
+	 * We make sure we know how many trees we need to allocate for
+	 * so we don't have to realloc and change the pointers for the
+	 * parents.
+	 */
+	ntrees = 0;
+	for (i = 0; i < nentries; i++) {
+		const git_tree_entry *entry;
+
+		entry = git_tree_entry_byindex(tree, i);
+		if (git_tree_entry_filemode(entry) == GIT_FILEMODE_TREE)
+			ntrees++;
+	}
+
+	cache->children_count = ntrees;
+	cache->children = git_pool_mallocz(pool, ntrees * sizeof(git_tree_cache *));
+	GITERR_CHECK_ALLOC(cache->children);
+
+	j = 0;
+	for (i = 0; i < nentries; i++) {
+		const git_tree_entry *entry;
+		git_tree *subtree;
+
+		entry = git_tree_entry_byindex(tree, i);
+		if (git_tree_entry_filemode(entry) != GIT_FILEMODE_TREE) {
+			cache->entry_count++;
+			continue;
+		}
+
+		if ((error = git_tree_cache_new(&cache->children[j], git_tree_entry_name(entry), pool)) < 0)
+			return error;
+
+		if ((error = git_tree_lookup(&subtree, repo, git_tree_entry_id(entry))) < 0)
+			return error;
+
+		error = read_tree_recursive(cache->children[j], subtree, pool);
+		git_tree_free(subtree);
+		cache->entry_count += cache->children[j]->entry_count;
+		j++;
+
+		if (error < 0)
+			return error;
+	}
+
+	return 0;
+}
+
+int git_tree_cache_read_tree(git_tree_cache **out, const git_tree *tree, git_pool *pool)
+{
+	int error;
+	git_tree_cache *cache;
+
+	if ((error = git_tree_cache_new(&cache, "", pool)) < 0)
+		return error;
+
+	if ((error = read_tree_recursive(cache, tree, pool)) < 0)
+		return error;
+
+	*out = cache;
+	return 0;
+}
+
+int git_tree_cache_new(git_tree_cache **out, const char *name, git_pool *pool)
+{
+	size_t name_len;
+	git_tree_cache *tree;
+
+	name_len = strlen(name);
+	tree = git_pool_malloc(pool, sizeof(git_tree_cache) + name_len + 1);
+	GITERR_CHECK_ALLOC(tree);
+
+	memset(tree, 0x0, sizeof(git_tree_cache));
+	/* NUL-terminated tree name */
+	tree->namelen = name_len;
+	memcpy(tree->name, name, name_len);
+	tree->name[name_len] = '\0';
+
+	*out = tree;
+	return 0;
+}
+
+static void write_tree(git_buf *out, git_tree_cache *tree)
+{
+	size_t i;
+
+	git_buf_printf(out, "%s%c%"PRIdZ" %"PRIuZ"\n", tree->name, 0, tree->entry_count, tree->children_count);
+
+	if (tree->entry_count != -1)
+		git_buf_put(out, (const char *) &tree->oid, GIT_OID_RAWSZ);
+
+	for (i = 0; i < tree->children_count; i++)
+		write_tree(out, tree->children[i]);
+}
+
+int git_tree_cache_write(git_buf *out, git_tree_cache *tree)
+{
+	write_tree(out, tree);
+
+	return git_buf_oom(out) ? -1 : 0;
+}

vendor/libgit2-sys/libgit2/src/tree-cache.h

diff --git a/vendor/libgit2-sys/libgit2/src/tree-cache.h b/vendor/libgit2-sys/libgit2/src/tree-cache.h
new file mode 100644
index 0000000..e02300e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/tree-cache.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_tree_cache_h__
+#define INCLUDE_tree_cache_h__
+
+#include "common.h"
+
+#include "pool.h"
+#include "buffer.h"
+#include "git2/oid.h"
+
+typedef struct git_tree_cache {
+	struct git_tree_cache **children;
+	size_t children_count;
+
+	ssize_t entry_count;
+	git_oid oid;
+	size_t namelen;
+	char name[GIT_FLEX_ARRAY];
+} git_tree_cache;
+
+int git_tree_cache_write(git_buf *out, git_tree_cache *tree);
+int git_tree_cache_read(git_tree_cache **tree, const char *buffer, size_t buffer_size, git_pool *pool);
+void git_tree_cache_invalidate_path(git_tree_cache *tree, const char *path);
+const git_tree_cache *git_tree_cache_get(const git_tree_cache *tree, const char *path);
+int git_tree_cache_new(git_tree_cache **out, const char *name, git_pool *pool);
+/**
+ * Read a tree as the root of the tree cache (like for `git read-tree`)
+ */
+int git_tree_cache_read_tree(git_tree_cache **out, const git_tree *tree, git_pool *pool);
+void git_tree_cache_free(git_tree_cache *tree);
+
+#endif

vendor/libgit2-sys/libgit2/src/tree.c

diff --git a/vendor/libgit2-sys/libgit2/src/tree.c b/vendor/libgit2-sys/libgit2/src/tree.c
new file mode 100644
index 0000000..1262297
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/tree.c
@@ -0,0 +1,1327 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "tree.h"
+
+#include "commit.h"
+#include "git2/repository.h"
+#include "git2/object.h"
+#include "fileops.h"
+#include "tree-cache.h"
+#include "index.h"
+
+#define DEFAULT_TREE_SIZE 16
+#define MAX_FILEMODE_BYTES 6
+
+#define TREE_ENTRY_CHECK_NAMELEN(n) \
+	if (n > UINT16_MAX) { giterr_set(GITERR_INVALID, "tree entry path too long"); }
+
+static bool valid_filemode(const int filemode)
+{
+	return (filemode == GIT_FILEMODE_TREE
+		|| filemode == GIT_FILEMODE_BLOB
+		|| filemode == GIT_FILEMODE_BLOB_EXECUTABLE
+		|| filemode == GIT_FILEMODE_LINK
+		|| filemode == GIT_FILEMODE_COMMIT);
+}
+
+GIT_INLINE(git_filemode_t) normalize_filemode(git_filemode_t filemode)
+{
+	/* Tree bits set, but it's not a commit */
+	if (GIT_MODE_TYPE(filemode) == GIT_FILEMODE_TREE)
+		return GIT_FILEMODE_TREE;
+
+	/* If any of the x bits are set */
+	if (GIT_PERMS_IS_EXEC(filemode))
+		return GIT_FILEMODE_BLOB_EXECUTABLE;
+
+	/* 16XXXX means commit */
+	if (GIT_MODE_TYPE(filemode) == GIT_FILEMODE_COMMIT)
+		return GIT_FILEMODE_COMMIT;
+
+	/* 12XXXX means symlink */
+	if (GIT_MODE_TYPE(filemode) == GIT_FILEMODE_LINK)
+		return GIT_FILEMODE_LINK;
+
+	/* Otherwise, return a blob */
+	return GIT_FILEMODE_BLOB;
+}
+
+static int valid_entry_name(git_repository *repo, const char *filename)
+{
+	return *filename != '\0' &&
+		git_path_isvalid(repo, filename, 0,
+		GIT_PATH_REJECT_TRAVERSAL | GIT_PATH_REJECT_DOT_GIT | GIT_PATH_REJECT_SLASH);
+}
+
+static int entry_sort_cmp(const void *a, const void *b)
+{
+	const git_tree_entry *e1 = (const git_tree_entry *)a;
+	const git_tree_entry *e2 = (const git_tree_entry *)b;
+
+	return git_path_cmp(
+		e1->filename, e1->filename_len, git_tree_entry__is_tree(e1),
+		e2->filename, e2->filename_len, git_tree_entry__is_tree(e2),
+		git__strncmp);
+}
+
+int git_tree_entry_cmp(const git_tree_entry *e1, const git_tree_entry *e2)
+{
+	return entry_sort_cmp(e1, e2);
+}
+
+int git_tree_entry_icmp(const git_tree_entry *e1, const git_tree_entry *e2)
+{
+	return git_path_cmp(
+		e1->filename, e1->filename_len, git_tree_entry__is_tree(e1),
+		e2->filename, e2->filename_len, git_tree_entry__is_tree(e2),
+		git__strncasecmp);
+}
+
+/**
+ * Allocate a new self-contained entry, with enough space after it to
+ * store the filename and the id.
+ */
+static git_tree_entry *alloc_entry(const char *filename, size_t filename_len, const git_oid *id)
+{
+	git_tree_entry *entry = NULL;
+	size_t tree_len;
+
+	TREE_ENTRY_CHECK_NAMELEN(filename_len);
+
+	if (GIT_ADD_SIZET_OVERFLOW(&tree_len, sizeof(git_tree_entry), filename_len) ||
+	    GIT_ADD_SIZET_OVERFLOW(&tree_len, tree_len, 1) ||
+	    GIT_ADD_SIZET_OVERFLOW(&tree_len, tree_len, GIT_OID_RAWSZ))
+		return NULL;
+
+	entry = git__calloc(1, tree_len);
+	if (!entry)
+		return NULL;
+
+	{
+		char *filename_ptr;
+		void *id_ptr;
+
+		filename_ptr = ((char *) entry) + sizeof(git_tree_entry);
+		memcpy(filename_ptr, filename, filename_len);
+		entry->filename = filename_ptr;
+
+		id_ptr = filename_ptr + filename_len + 1;
+		git_oid_cpy(id_ptr, id);
+		entry->oid = id_ptr;
+	}
+
+	entry->filename_len = (uint16_t)filename_len;
+
+	return entry;
+}
+
+struct tree_key_search {
+	const char *filename;
+	uint16_t filename_len;
+};
+
+static int homing_search_cmp(const void *key, const void *array_member)
+{
+	const struct tree_key_search *ksearch = key;
+	const git_tree_entry *entry = array_member;
+
+	const uint16_t len1 = ksearch->filename_len;
+	const uint16_t len2 = entry->filename_len;
+
+	return memcmp(
+		ksearch->filename,
+		entry->filename,
+		len1 < len2 ? len1 : len2
+	);
+}
+
+/*
+ * Search for an entry in a given tree.
+ *
+ * Note that this search is performed in two steps because
+ * of the way tree entries are sorted internally in git:
+ *
+ * Entries in a tree are not sorted alphabetically; two entries
+ * with the same root prefix will have different positions
+ * depending on whether they are folders (subtrees) or normal files.
+ *
+ * Consequently, it is not possible to find an entry on the tree
+ * with a binary search if you don't know whether the filename
+ * you're looking for is a folder or a normal file.
+ *
+ * To work around this, we first perform a homing binary search
+ * on the tree, using the minimal length root prefix of our filename.
+ * Once the comparisons for this homing search start becoming
+ * ambiguous because of folder vs file sorting, we look linearly
+ * around the area for our target file.
+ */
+static int tree_key_search(
+	size_t *at_pos,
+	const git_tree *tree,
+	const char *filename,
+	size_t filename_len)
+{
+	struct tree_key_search ksearch;
+	const git_tree_entry *entry;
+	size_t homing, i;
+
+	TREE_ENTRY_CHECK_NAMELEN(filename_len);
+
+	ksearch.filename = filename;
+	ksearch.filename_len = (uint16_t)filename_len;
+
+	/* Initial homing search; find an entry on the tree with
+	 * the same prefix as the filename we're looking for */
+
+	if (git_array_search(&homing,
+		tree->entries, &homing_search_cmp, &ksearch) < 0)
+		return GIT_ENOTFOUND; /* just a signal error; not passed back to user */
+
+	/* We found a common prefix. Look forward as long as
+	 * there are entries that share the common prefix */
+	for (i = homing; i < tree->entries.size; ++i) {
+		entry = git_array_get(tree->entries, i);
+
+		if (homing_search_cmp(&ksearch, entry) < 0)
+			break;
+
+		if (entry->filename_len == filename_len &&
+			memcmp(filename, entry->filename, filename_len) == 0) {
+			if (at_pos)
+				*at_pos = i;
+
+			return 0;
+		}
+	}
+
+	/* If we haven't found our filename yet, look backwards
+	 * too as long as we have entries with the same prefix */
+	if (homing > 0) {
+		i = homing - 1;
+
+		do {
+			entry = git_array_get(tree->entries, i);
+
+			if (homing_search_cmp(&ksearch, entry) > 0)
+				break;
+
+			if (entry->filename_len == filename_len &&
+				memcmp(filename, entry->filename, filename_len) == 0) {
+				if (at_pos)
+					*at_pos = i;
+
+				return 0;
+			}
+		} while (i-- > 0);
+	}
+
+	/* The filename doesn't exist at all */
+	return GIT_ENOTFOUND;
+}
+
+void git_tree_entry_free(git_tree_entry *entry)
+{
+	if (entry == NULL)
+		return;
+
+	git__free(entry);
+}
+
+int git_tree_entry_dup(git_tree_entry **dest, const git_tree_entry *source)
+{
+	git_tree_entry *cpy;
+
+	assert(source);
+
+	cpy = alloc_entry(source->filename, source->filename_len, source->oid);
+	if (cpy == NULL)
+		return -1;
+
+	cpy->attr = source->attr;
+
+	*dest = cpy;
+	return 0;
+}
+
+void git_tree__free(void *_tree)
+{
+	git_tree *tree = _tree;
+
+	git_odb_object_free(tree->odb_obj);
+	git_array_clear(tree->entries);
+	git__free(tree);
+}
+
+git_filemode_t git_tree_entry_filemode(const git_tree_entry *entry)
+{
+	return normalize_filemode(entry->attr);
+}
+
+git_filemode_t git_tree_entry_filemode_raw(const git_tree_entry *entry)
+{
+	return entry->attr;
+}
+
+const char *git_tree_entry_name(const git_tree_entry *entry)
+{
+	assert(entry);
+	return entry->filename;
+}
+
+const git_oid *git_tree_entry_id(const git_tree_entry *entry)
+{
+	assert(entry);
+	return entry->oid;
+}
+
+git_otype git_tree_entry_type(const git_tree_entry *entry)
+{
+	assert(entry);
+
+	if (S_ISGITLINK(entry->attr))
+		return GIT_OBJ_COMMIT;
+	else if (S_ISDIR(entry->attr))
+		return GIT_OBJ_TREE;
+	else
+		return GIT_OBJ_BLOB;
+}
+
+int git_tree_entry_to_object(
+	git_object **object_out,
+	git_repository *repo,
+	const git_tree_entry *entry)
+{
+	assert(entry && object_out);
+	return git_object_lookup(object_out, repo, entry->oid, GIT_OBJ_ANY);
+}
+
+static const git_tree_entry *entry_fromname(
+	const git_tree *tree, const char *name, size_t name_len)
+{
+	size_t idx;
+
+	if (tree_key_search(&idx, tree, name, name_len) < 0)
+		return NULL;
+
+	return git_array_get(tree->entries, idx);
+}
+
+const git_tree_entry *git_tree_entry_byname(
+	const git_tree *tree, const char *filename)
+{
+	assert(tree && filename);
+
+	return entry_fromname(tree, filename, strlen(filename));
+}
+
+const git_tree_entry *git_tree_entry_byindex(
+	const git_tree *tree, size_t idx)
+{
+	assert(tree);
+	return git_array_get(tree->entries, idx);
+}
+
+const git_tree_entry *git_tree_entry_byid(
+	const git_tree *tree, const git_oid *id)
+{
+	size_t i;
+	const git_tree_entry *e;
+
+	assert(tree);
+
+	git_array_foreach(tree->entries, i, e) {
+		if (memcmp(&e->oid->id, &id->id, sizeof(id->id)) == 0)
+			return e;
+	}
+
+	return NULL;
+}
+
+int git_tree__prefix_position(const git_tree *tree, const char *path)
+{
+	struct tree_key_search ksearch;
+	size_t at_pos, path_len;
+
+	if (!path)
+		return 0;
+
+	path_len = strlen(path);
+	TREE_ENTRY_CHECK_NAMELEN(path_len);
+
+	ksearch.filename = path;
+	ksearch.filename_len = (uint16_t)path_len;
+
+	/* Find tree entry with appropriate prefix */
+	git_array_search(
+		&at_pos, tree->entries, &homing_search_cmp, &ksearch);
+
+	for (; at_pos < tree->entries.size; ++at_pos) {
+		const git_tree_entry *entry = git_array_get(tree->entries, at_pos);
+		if (homing_search_cmp(&ksearch, entry) < 0)
+			break;
+	}
+
+	for (; at_pos > 0; --at_pos) {
+		const git_tree_entry *entry =
+			git_array_get(tree->entries, at_pos - 1);
+
+		if (homing_search_cmp(&ksearch, entry) > 0)
+			break;
+	}
+
+	return (int)at_pos;
+}
+
+size_t git_tree_entrycount(const git_tree *tree)
+{
+	assert(tree);
+	return tree->entries.size;
+}
+
+unsigned int git_treebuilder_entrycount(git_treebuilder *bld)
+{
+	assert(bld);
+
+	return git_strmap_num_entries(bld->map);
+}
+
+static int tree_error(const char *str, const char *path)
+{
+	if (path)
+		giterr_set(GITERR_TREE, "%s - %s", str, path);
+	else
+		giterr_set(GITERR_TREE, "%s", str);
+	return -1;
+}
+
+static int parse_mode(unsigned int *modep, const char *buffer, const char **buffer_out)
+{
+	unsigned char c;
+	unsigned int mode = 0;
+
+	if (*buffer == ' ')
+		return -1;
+
+	while ((c = *buffer++) != ' ') {
+		if (c < '0' || c > '7')
+			return -1;
+		mode = (mode << 3) + (c - '0');
+	}
+	*modep = mode;
+	*buffer_out = buffer;
+
+	return 0;
+}
+
+int git_tree__parse(void *_tree, git_odb_object *odb_obj)
+{
+	git_tree *tree = _tree;
+	const char *buffer;
+	const char *buffer_end;
+
+	if (git_odb_object_dup(&tree->odb_obj, odb_obj) < 0)
+		return -1;
+
+	buffer = git_odb_object_data(tree->odb_obj);
+	buffer_end = buffer + git_odb_object_size(tree->odb_obj);
+
+	git_array_init_to_size(tree->entries, DEFAULT_TREE_SIZE);
+	GITERR_CHECK_ARRAY(tree->entries);
+
+	while (buffer < buffer_end) {
+		git_tree_entry *entry;
+		size_t filename_len;
+		const char *nul;
+		unsigned int attr;
+
+		if (parse_mode(&attr, buffer, &buffer) < 0 || !buffer)
+			return tree_error("failed to parse tree: can't parse filemode", NULL);
+
+		if ((nul = memchr(buffer, 0, buffer_end - buffer)) == NULL)
+			return tree_error("failed to parse tree: object is corrupted", NULL);
+
+		if ((filename_len = nul - buffer) == 0)
+			return tree_error("failed to parse tree: can't parse filename", NULL);
+
+		if ((buffer_end - (nul + 1)) < GIT_OID_RAWSZ)
+			return tree_error("failed to parse tree: can't parse OID", NULL);
+
+		/* Allocate the entry */
+		{
+			entry = git_array_alloc(tree->entries);
+			GITERR_CHECK_ALLOC(entry);
+
+			entry->attr = attr;
+			entry->filename_len = filename_len;
+			entry->filename = buffer;
+			entry->oid = (git_oid *) ((char *) buffer + filename_len + 1);
+		}
+
+		buffer += filename_len + 1;
+		buffer += GIT_OID_RAWSZ;
+	}
+
+	return 0;
+}
+
+static size_t find_next_dir(const char *dirname, git_index *index, size_t start)
+{
+	size_t dirlen, i, entries = git_index_entrycount(index);
+
+	dirlen = strlen(dirname);
+	for (i = start; i < entries; ++i) {
+		const git_index_entry *entry = git_index_get_byindex(index, i);
+		if (strlen(entry->path) < dirlen ||
+		    memcmp(entry->path, dirname, dirlen) ||
+			(dirlen > 0 && entry->path[dirlen] != '/')) {
+			break;
+		}
+	}
+
+	return i;
+}
+
+static int append_entry(
+	git_treebuilder *bld,
+	const char *filename,
+	const git_oid *id,
+	git_filemode_t filemode)
+{
+	git_tree_entry *entry;
+	int error = 0;
+
+	if (!valid_entry_name(bld->repo, filename))
+		return tree_error("failed to insert entry: invalid name for a tree entry", filename);
+
+	if (git_oid_iszero(id))
+		return tree_error("failed to insert entry: invalid null OID for a tree entry", filename);
+
+	entry = alloc_entry(filename, strlen(filename), id);
+	GITERR_CHECK_ALLOC(entry);
+
+	entry->attr = (uint16_t)filemode;
+
+	git_strmap_insert(bld->map, entry->filename, entry, &error);
+	if (error < 0) {
+		git_tree_entry_free(entry);
+		giterr_set(GITERR_TREE, "failed to append entry %s to the tree builder", filename);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int write_tree(
+	git_oid *oid,
+	git_repository *repo,
+	git_index *index,
+	const char *dirname,
+	size_t start,
+	git_buf *shared_buf)
+{
+	git_treebuilder *bld = NULL;
+	size_t i, entries = git_index_entrycount(index);
+	int error;
+	size_t dirname_len = strlen(dirname);
+	const git_tree_cache *cache;
+
+	cache = git_tree_cache_get(index->tree, dirname);
+	if (cache != NULL && cache->entry_count >= 0){
+		git_oid_cpy(oid, &cache->oid);
+		return (int)find_next_dir(dirname, index, start);
+	}
+
+	if ((error = git_treebuilder_new(&bld, repo, NULL)) < 0 || bld == NULL)
+		return -1;
+
+	/*
+	 * This loop is unfortunate, but necessary. The index doesn't have
+	 * any directores, so we need to handle that manually, and we
+	 * need to keep track of the current position.
+	 */
+	for (i = start; i < entries; ++i) {
+		const git_index_entry *entry = git_index_get_byindex(index, i);
+		const char *filename, *next_slash;
+
+	/*
+	 * If we've left our (sub)tree, exit the loop and return. The
+	 * first check is an early out (and security for the
+	 * third). The second check is a simple prefix comparison. The
+	 * third check catches situations where there is a directory
+	 * win32/sys and a file win32mmap.c. Without it, the following
+	 * code believes there is a file win32/mmap.c
+	 */
+		if (strlen(entry->path) < dirname_len ||
+		    memcmp(entry->path, dirname, dirname_len) ||
+		    (dirname_len > 0 && entry->path[dirname_len] != '/')) {
+			break;
+		}
+
+		filename = entry->path + dirname_len;
+		if (*filename == '/')
+			filename++;
+		next_slash = strchr(filename, '/');
+		if (next_slash) {
+			git_oid sub_oid;
+			int written;
+			char *subdir, *last_comp;
+
+			subdir = git__strndup(entry->path, next_slash - entry->path);
+			GITERR_CHECK_ALLOC(subdir);
+
+			/* Write out the subtree */
+			written = write_tree(&sub_oid, repo, index, subdir, i, shared_buf);
+			if (written < 0) {
+				git__free(subdir);
+				goto on_error;
+			} else {
+				i = written - 1; /* -1 because of the loop increment */
+			}
+
+			/*
+			 * We need to figure out what we want toinsert
+			 * into this tree. If we're traversing
+			 * deps/zlib/, then we only want to write
+			 * 'zlib' into the tree.
+			 */
+			last_comp = strrchr(subdir, '/');
+			if (last_comp) {
+				last_comp++; /* Get rid of the '/' */
+			} else {
+				last_comp = subdir;
+			}
+
+			error = append_entry(bld, last_comp, &sub_oid, S_IFDIR);
+			git__free(subdir);
+			if (error < 0)
+				goto on_error;
+		} else {
+			error = append_entry(bld, filename, &entry->id, entry->mode);
+			if (error < 0)
+				goto on_error;
+		}
+	}
+
+	if (git_treebuilder_write_with_buffer(oid, bld, shared_buf) < 0)
+		goto on_error;
+
+	git_treebuilder_free(bld);
+	return (int)i;
+
+on_error:
+	git_treebuilder_free(bld);
+	return -1;
+}
+
+int git_tree__write_index(
+	git_oid *oid, git_index *index, git_repository *repo)
+{
+	int ret;
+	git_tree *tree;
+	git_buf shared_buf = GIT_BUF_INIT;
+	bool old_ignore_case = false;
+
+	assert(oid && index && repo);
+
+	if (git_index_has_conflicts(index)) {
+		giterr_set(GITERR_INDEX,
+			"cannot create a tree from a not fully merged index.");
+		return GIT_EUNMERGED;
+	}
+
+	if (index->tree != NULL && index->tree->entry_count >= 0) {
+		git_oid_cpy(oid, &index->tree->oid);
+		return 0;
+	}
+
+	/* The tree cache didn't help us; we'll have to write
+	 * out a tree. If the index is ignore_case, we must
+	 * make it case-sensitive for the duration of the tree-write
+	 * operation. */
+
+	if (index->ignore_case) {
+		old_ignore_case = true;
+		git_index__set_ignore_case(index, false);
+	}
+
+	ret = write_tree(oid, repo, index, "", 0, &shared_buf);
+	git_buf_free(&shared_buf);
+
+	if (old_ignore_case)
+		git_index__set_ignore_case(index, true);
+
+	index->tree = NULL;
+
+	if (ret < 0)
+		return ret;
+
+	git_pool_clear(&index->tree_pool);
+
+	if ((ret = git_tree_lookup(&tree, repo, oid)) < 0)
+		return ret;
+
+	/* Read the tree cache into the index */
+	ret = git_tree_cache_read_tree(&index->tree, tree, &index->tree_pool);
+	git_tree_free(tree);
+
+	return ret;
+}
+
+int git_treebuilder_new(
+	git_treebuilder **builder_p,
+	git_repository *repo,
+	const git_tree *source)
+{
+	git_treebuilder *bld;
+	size_t i;
+
+	assert(builder_p && repo);
+
+	bld = git__calloc(1, sizeof(git_treebuilder));
+	GITERR_CHECK_ALLOC(bld);
+
+	bld->repo = repo;
+
+	if (git_strmap_alloc(&bld->map) < 0) {
+		git__free(bld);
+		return -1;
+	}
+
+	if (source != NULL) {
+		git_tree_entry *entry_src;
+
+		git_array_foreach(source->entries, i, entry_src) {
+			if (append_entry(
+				bld, entry_src->filename,
+				entry_src->oid,
+				entry_src->attr) < 0)
+				goto on_error;
+		}
+	}
+
+	*builder_p = bld;
+	return 0;
+
+on_error:
+	git_treebuilder_free(bld);
+	return -1;
+}
+
+static git_otype otype_from_mode(git_filemode_t filemode)
+{
+	switch (filemode) {
+	case GIT_FILEMODE_TREE:
+		return GIT_OBJ_TREE;
+	case GIT_FILEMODE_COMMIT:
+		return GIT_OBJ_COMMIT;
+	default:
+		return GIT_OBJ_BLOB;
+	}
+}
+
+int git_treebuilder_insert(
+	const git_tree_entry **entry_out,
+	git_treebuilder *bld,
+	const char *filename,
+	const git_oid *id,
+	git_filemode_t filemode)
+{
+	git_tree_entry *entry;
+	int error;
+	git_strmap_iter pos;
+
+	assert(bld && id && filename);
+
+	if (!valid_filemode(filemode))
+		return tree_error("failed to insert entry: invalid filemode for file", filename);
+
+	if (!valid_entry_name(bld->repo, filename))
+		return tree_error("failed to insert entry: invalid name for a tree entry", filename);
+
+	if (git_oid_iszero(id))
+		return tree_error("failed to insert entry: invalid null OID", filename);
+
+	if (filemode != GIT_FILEMODE_COMMIT &&
+	    !git_object__is_valid(bld->repo, id, otype_from_mode(filemode)))
+		return tree_error("failed to insert entry: invalid object specified", filename);
+
+	pos = git_strmap_lookup_index(bld->map, filename);
+	if (git_strmap_valid_index(bld->map, pos)) {
+		entry = git_strmap_value_at(bld->map, pos);
+		git_oid_cpy((git_oid *) entry->oid, id);
+	} else {
+		entry = alloc_entry(filename, strlen(filename), id);
+		GITERR_CHECK_ALLOC(entry);
+
+		git_strmap_insert(bld->map, entry->filename, entry, &error);
+
+		if (error < 0) {
+			git_tree_entry_free(entry);
+			giterr_set(GITERR_TREE, "failed to insert %s", filename);
+			return -1;
+		}
+	}
+
+	entry->attr = filemode;
+
+	if (entry_out)
+		*entry_out = entry;
+
+	return 0;
+}
+
+static git_tree_entry *treebuilder_get(git_treebuilder *bld, const char *filename)
+{
+	git_tree_entry *entry = NULL;
+	git_strmap_iter pos;
+
+	assert(bld && filename);
+
+	pos = git_strmap_lookup_index(bld->map, filename);
+	if (git_strmap_valid_index(bld->map, pos))
+		entry = git_strmap_value_at(bld->map, pos);
+
+	return entry;
+}
+
+const git_tree_entry *git_treebuilder_get(git_treebuilder *bld, const char *filename)
+{
+	return treebuilder_get(bld, filename);
+}
+
+int git_treebuilder_remove(git_treebuilder *bld, const char *filename)
+{
+	git_tree_entry *entry = treebuilder_get(bld, filename);
+
+	if (entry == NULL)
+		return tree_error("failed to remove entry: file isn't in the tree", filename);
+
+	git_strmap_delete(bld->map, filename);
+	git_tree_entry_free(entry);
+
+	return 0;
+}
+
+int git_treebuilder_write(git_oid *oid, git_treebuilder *bld)
+{
+	int error;
+	git_buf buffer = GIT_BUF_INIT;
+
+	error = git_treebuilder_write_with_buffer(oid, bld, &buffer);
+
+	git_buf_free(&buffer);
+	return error;
+}
+
+int git_treebuilder_write_with_buffer(git_oid *oid, git_treebuilder *bld, git_buf *tree)
+{
+	int error = 0;
+	size_t i, entrycount;
+	git_odb *odb;
+	git_tree_entry *entry;
+	git_vector entries = GIT_VECTOR_INIT;
+
+	assert(bld);
+	assert(tree);
+
+	git_buf_clear(tree);
+
+	entrycount = git_strmap_num_entries(bld->map);
+	if ((error = git_vector_init(&entries, entrycount, entry_sort_cmp)) < 0)
+		goto out;
+
+	if (tree->asize == 0 &&
+	    (error = git_buf_grow(tree, entrycount * 72)) < 0)
+		goto out;
+
+	git_strmap_foreach_value(bld->map, entry, {
+		if ((error = git_vector_insert(&entries, entry)) < 0)
+			goto out;
+	});
+
+	git_vector_sort(&entries);
+
+	for (i = 0; i < entries.length && !error; ++i) {
+		entry = git_vector_get(&entries, i);
+
+		git_buf_printf(tree, "%o ", entry->attr);
+		git_buf_put(tree, entry->filename, entry->filename_len + 1);
+		git_buf_put(tree, (char *)entry->oid->id, GIT_OID_RAWSZ);
+
+		if (git_buf_oom(tree)) {
+			error = -1;
+			goto out;
+		}
+	}
+
+	if ((error = git_repository_odb__weakptr(&odb, bld->repo)) == 0)
+		error = git_odb_write(oid, odb, tree->ptr, tree->size, GIT_OBJ_TREE);
+
+out:
+	git_vector_free(&entries);
+
+	return error;
+}
+
+void git_treebuilder_filter(
+	git_treebuilder *bld,
+	git_treebuilder_filter_cb filter,
+	void *payload)
+{
+	const char *filename;
+	git_tree_entry *entry;
+
+	assert(bld && filter);
+
+	git_strmap_foreach(bld->map, filename, entry, {
+			if (filter(entry, payload)) {
+				git_strmap_delete(bld->map, filename);
+				git_tree_entry_free(entry);
+			}
+	});
+}
+
+void git_treebuilder_clear(git_treebuilder *bld)
+{
+	git_tree_entry *e;
+
+	assert(bld);
+
+	git_strmap_foreach_value(bld->map, e, git_tree_entry_free(e));
+	git_strmap_clear(bld->map);
+}
+
+void git_treebuilder_free(git_treebuilder *bld)
+{
+	if (bld == NULL)
+		return;
+
+	git_treebuilder_clear(bld);
+	git_strmap_free(bld->map);
+	git__free(bld);
+}
+
+static size_t subpath_len(const char *path)
+{
+	const char *slash_pos = strchr(path, '/');
+	if (slash_pos == NULL)
+		return strlen(path);
+
+	return slash_pos - path;
+}
+
+int git_tree_entry_bypath(
+	git_tree_entry **entry_out,
+	const git_tree *root,
+	const char *path)
+{
+	int error = 0;
+	git_tree *subtree;
+	const git_tree_entry *entry;
+	size_t filename_len;
+
+	/* Find how long is the current path component (i.e.
+	 * the filename between two slashes */
+	filename_len = subpath_len(path);
+
+	if (filename_len == 0) {
+		giterr_set(GITERR_TREE, "invalid tree path given");
+		return GIT_ENOTFOUND;
+	}
+
+	entry = entry_fromname(root, path, filename_len);
+
+	if (entry == NULL) {
+		giterr_set(GITERR_TREE,
+			   "the path '%.*s' does not exist in the given tree", (int) filename_len, path);
+		return GIT_ENOTFOUND;
+	}
+
+	switch (path[filename_len]) {
+	case '/':
+		/* If there are more components in the path...
+		 * then this entry *must* be a tree */
+		if (!git_tree_entry__is_tree(entry)) {
+			giterr_set(GITERR_TREE,
+				   "the path '%.*s' exists but is not a tree", (int) filename_len, path);
+			return GIT_ENOTFOUND;
+		}
+
+		/* If there's only a slash left in the path, we
+		 * return the current entry; otherwise, we keep
+		 * walking down the path */
+		if (path[filename_len + 1] != '\0')
+			break;
+		/* fall through */
+	case '\0':
+		/* If there are no more components in the path, return
+		 * this entry */
+		return git_tree_entry_dup(entry_out, entry);
+	}
+
+	if (git_tree_lookup(&subtree, root->object.repo, entry->oid) < 0)
+		return -1;
+
+	error = git_tree_entry_bypath(
+		entry_out,
+		subtree,
+		path + filename_len + 1
+	);
+
+	git_tree_free(subtree);
+	return error;
+}
+
+static int tree_walk(
+	const git_tree *tree,
+	git_treewalk_cb callback,
+	git_buf *path,
+	void *payload,
+	bool preorder)
+{
+	int error = 0;
+	size_t i;
+	const git_tree_entry *entry;
+
+	git_array_foreach(tree->entries, i, entry) {
+		if (preorder) {
+			error = callback(path->ptr, entry, payload);
+			if (error < 0) { /* negative value stops iteration */
+				giterr_set_after_callback_function(error, "git_tree_walk");
+				break;
+			}
+			if (error > 0) { /* positive value skips this entry */
+				error = 0;
+				continue;
+			}
+		}
+
+		if (git_tree_entry__is_tree(entry)) {
+			git_tree *subtree;
+			size_t path_len = git_buf_len(path);
+
+			error = git_tree_lookup(&subtree, tree->object.repo, entry->oid);
+			if (error < 0)
+				break;
+
+			/* append the next entry to the path */
+			git_buf_puts(path, entry->filename);
+			git_buf_putc(path, '/');
+
+			if (git_buf_oom(path))
+				error = -1;
+			else
+				error = tree_walk(subtree, callback, path, payload, preorder);
+
+			git_tree_free(subtree);
+			if (error != 0)
+				break;
+
+			git_buf_truncate(path, path_len);
+		}
+
+		if (!preorder) {
+			error = callback(path->ptr, entry, payload);
+			if (error < 0) { /* negative value stops iteration */
+				giterr_set_after_callback_function(error, "git_tree_walk");
+				break;
+			}
+			error = 0;
+		}
+	}
+
+	return error;
+}
+
+int git_tree_walk(
+	const git_tree *tree,
+	git_treewalk_mode mode,
+	git_treewalk_cb callback,
+	void *payload)
+{
+	int error = 0;
+	git_buf root_path = GIT_BUF_INIT;
+
+	if (mode != GIT_TREEWALK_POST && mode != GIT_TREEWALK_PRE) {
+		giterr_set(GITERR_INVALID, "invalid walking mode for tree walk");
+		return -1;
+	}
+
+	error = tree_walk(
+		tree, callback, &root_path, payload, (mode == GIT_TREEWALK_PRE));
+
+	git_buf_free(&root_path);
+
+	return error;
+}
+
+static int compare_entries(const void *_a, const void *_b)
+{
+	const git_tree_update *a = (git_tree_update *) _a;
+	const git_tree_update *b = (git_tree_update *) _b;
+
+	return strcmp(a->path, b->path);
+}
+
+static int on_dup_entry(void **old, void *new)
+{
+	GIT_UNUSED(old); GIT_UNUSED(new);
+
+	giterr_set(GITERR_TREE, "duplicate entries given for update");
+	return -1;
+}
+
+/*
+ * We keep the previous tree and the new one at each level of the
+ * stack. When we leave a level we're done with that tree and we can
+ * write it out to the odb.
+ */
+typedef struct {
+	git_treebuilder *bld;
+	git_tree *tree;
+	char *name;
+} tree_stack_entry;
+
+/** Count how many slashes (i.e. path components) there are in this string */
+GIT_INLINE(size_t) count_slashes(const char *path)
+{
+	size_t count = 0;
+	const char *slash;
+
+	while ((slash = strchr(path, '/')) != NULL) {
+		count++;
+		path = slash + 1;
+	}
+
+	return count;
+}
+
+static bool next_component(git_buf *out, const char *in)
+{
+	const char *slash = strchr(in, '/');
+
+	git_buf_clear(out);
+
+	if (slash)
+		git_buf_put(out, in, slash - in);
+
+	return !!slash;
+}
+
+static int create_popped_tree(tree_stack_entry *current, tree_stack_entry *popped, git_buf *component)
+{
+	int error;
+	git_oid new_tree;
+
+	git_tree_free(popped->tree);
+
+	/* If the tree would be empty, remove it from the one higher up */
+	if (git_treebuilder_entrycount(popped->bld) == 0) {
+		git_treebuilder_free(popped->bld);
+		error = git_treebuilder_remove(current->bld, popped->name);
+		git__free(popped->name);
+		return error;
+	}
+
+	error = git_treebuilder_write(&new_tree, popped->bld);
+	git_treebuilder_free(popped->bld);
+
+	if (error < 0) {
+		git__free(popped->name);
+		return error;
+	}
+
+	/* We've written out the tree, now we have to put the new value into its parent */
+	git_buf_clear(component);
+	git_buf_puts(component, popped->name);
+	git__free(popped->name);
+
+	GITERR_CHECK_ALLOC(component->ptr);
+
+	/* Error out if this would create a D/F conflict in this update */
+	if (current->tree) {
+		const git_tree_entry *to_replace;
+		to_replace = git_tree_entry_byname(current->tree, component->ptr);
+		if (to_replace && git_tree_entry_type(to_replace) != GIT_OBJ_TREE) {
+			giterr_set(GITERR_TREE, "D/F conflict when updating tree");
+			return -1;
+		}
+	}
+
+	return git_treebuilder_insert(NULL, current->bld, component->ptr, &new_tree, GIT_FILEMODE_TREE);
+}
+
+int git_tree_create_updated(git_oid *out, git_repository *repo, git_tree *baseline, size_t nupdates, const git_tree_update *updates)
+{
+	git_array_t(tree_stack_entry) stack = GIT_ARRAY_INIT;
+	tree_stack_entry *root_elem;
+	git_vector entries;
+	int error;
+	size_t i;
+	git_buf component = GIT_BUF_INIT;
+
+	if ((error = git_vector_init(&entries, nupdates, compare_entries)) < 0)
+		return error;
+
+	/* Sort the entries for treversal */
+	for (i = 0 ; i < nupdates; i++)	{
+		if ((error = git_vector_insert_sorted(&entries, (void *) &updates[i], on_dup_entry)) < 0)
+			goto cleanup;
+	}
+
+	root_elem = git_array_alloc(stack);
+	GITERR_CHECK_ALLOC(root_elem);
+	memset(root_elem, 0, sizeof(*root_elem));
+
+	if (baseline && (error = git_tree_dup(&root_elem->tree, baseline)) < 0)
+		goto cleanup;
+
+	if ((error = git_treebuilder_new(&root_elem->bld, repo, root_elem->tree)) < 0)
+		goto cleanup;
+
+	for (i = 0; i < nupdates; i++) {
+		const git_tree_update *last_update = i == 0 ? NULL : git_vector_get(&entries, i-1);
+		const git_tree_update *update = git_vector_get(&entries, i);
+		size_t common_prefix = 0, steps_up, j;
+		const char *path;
+
+		/* Figure out how much we need to change from the previous tree */
+		if (last_update)
+			common_prefix = git_path_common_dirlen(last_update->path, update->path);
+
+		/*
+		 * The entries are sorted, so when we find we're no
+		 * longer in the same directory, we need to abandon
+		 * the old tree (steps up) and dive down to the next
+		 * one.
+		 */
+		steps_up = last_update == NULL ? 0 : count_slashes(&last_update->path[common_prefix]);
+
+		for (j = 0; j < steps_up; j++) {
+			tree_stack_entry *current, *popped = git_array_pop(stack);
+			assert(popped);
+
+			current = git_array_last(stack);
+			assert(current);
+
+			if ((error = create_popped_tree(current, popped, &component)) < 0)
+				goto cleanup;
+		}
+
+		/* Now that we've created the trees we popped from the stack, let's go back down */
+		path = &update->path[common_prefix];
+		while (next_component(&component, path)) {
+			tree_stack_entry *last, *new_entry;
+			const git_tree_entry *entry;
+
+			last = git_array_last(stack);
+			entry = last->tree ? git_tree_entry_byname(last->tree, component.ptr) : NULL;
+			if (!entry)
+				entry = treebuilder_get(last->bld, component.ptr);
+
+			if (entry && git_tree_entry_type(entry) != GIT_OBJ_TREE) {
+				giterr_set(GITERR_TREE, "D/F conflict when updating tree");
+				error = -1;
+				goto cleanup;
+			}
+
+			new_entry = git_array_alloc(stack);
+			GITERR_CHECK_ALLOC(new_entry);
+			memset(new_entry, 0, sizeof(*new_entry));
+
+			new_entry->tree = NULL;
+			if (entry && (error = git_tree_lookup(&new_entry->tree, repo, git_tree_entry_id(entry))) < 0)
+				goto cleanup;
+
+			if ((error = git_treebuilder_new(&new_entry->bld, repo, new_entry->tree)) < 0)
+				goto cleanup;
+
+			new_entry->name = git__strdup(component.ptr);
+			GITERR_CHECK_ALLOC(new_entry->name);
+
+			/* Get to the start of the next component */
+			path += component.size + 1;
+		}
+
+		/* After all that, we're finally at the place where we want to perform the update */
+		switch (update->action) {
+			case GIT_TREE_UPDATE_UPSERT:
+			{
+				/* Make sure we're replacing something of the same type */
+				tree_stack_entry *last = git_array_last(stack);
+				char *basename = git_path_basename(update->path);
+				const git_tree_entry *e = git_treebuilder_get(last->bld, basename);
+				if (e && git_tree_entry_type(e) != git_object__type_from_filemode(update->filemode)) {
+					git__free(basename);
+					giterr_set(GITERR_TREE, "cannot replace '%s' with '%s' at '%s'",
+						   git_object_type2string(git_tree_entry_type(e)),
+						   git_object_type2string(git_object__type_from_filemode(update->filemode)),
+						   update->path);
+					error = -1;
+					goto cleanup;
+				}
+
+				error = git_treebuilder_insert(NULL, last->bld, basename, &update->id, update->filemode);
+				git__free(basename);
+				break;
+			}
+			case GIT_TREE_UPDATE_REMOVE:
+			{
+				char *basename = git_path_basename(update->path);
+				error = git_treebuilder_remove(git_array_last(stack)->bld, basename);
+				git__free(basename);
+				break;
+			}
+			default:
+				giterr_set(GITERR_TREE, "unknown action for update");
+				error = -1;
+				goto cleanup;
+		}
+
+		if (error < 0)
+			goto cleanup;
+	}
+
+	/* We're done, go up the stack again and write out the tree */
+	{
+		tree_stack_entry *current = NULL, *popped = NULL;
+		while ((popped = git_array_pop(stack)) != NULL) {
+			current = git_array_last(stack);
+			/* We've reached the top, current is the root tree */
+			if (!current)
+				break;
+
+			if ((error = create_popped_tree(current, popped, &component)) < 0)
+				goto cleanup;
+		}
+
+		/* Write out the root tree */
+		git__free(popped->name);
+		git_tree_free(popped->tree);
+
+		error = git_treebuilder_write(out, popped->bld);
+		git_treebuilder_free(popped->bld);
+		if (error < 0)
+			goto cleanup;
+	}
+
+cleanup:
+	{
+		tree_stack_entry *e;
+		while ((e = git_array_pop(stack)) != NULL) {
+			git_treebuilder_free(e->bld);
+			git_tree_free(e->tree);
+			git__free(e->name);
+		}
+	}
+
+	git_buf_free(&component);
+	git_array_clear(stack);
+	git_vector_free(&entries);
+	return error;
+}

vendor/libgit2-sys/libgit2/src/tree.h

diff --git a/vendor/libgit2-sys/libgit2/src/tree.h b/vendor/libgit2-sys/libgit2/src/tree.h
new file mode 100644
index 0000000..00f4b06
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/tree.h
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_tree_h__
+#define INCLUDE_tree_h__
+
+#include "common.h"
+
+#include "git2/tree.h"
+#include "repository.h"
+#include "odb.h"
+#include "vector.h"
+#include "strmap.h"
+#include "pool.h"
+
+struct git_tree_entry {
+	uint16_t attr;
+	uint16_t filename_len;
+	const git_oid *oid;
+	const char *filename;
+};
+
+struct git_tree {
+	git_object object;
+	git_odb_object *odb_obj;
+	git_array_t(git_tree_entry) entries;
+};
+
+struct git_treebuilder {
+	git_repository *repo;
+	git_strmap *map;
+};
+
+GIT_INLINE(bool) git_tree_entry__is_tree(const struct git_tree_entry *e)
+{
+	return (S_ISDIR(e->attr) && !S_ISGITLINK(e->attr));
+}
+
+extern int git_tree_entry_icmp(const git_tree_entry *e1, const git_tree_entry *e2);
+
+void git_tree__free(void *tree);
+int git_tree__parse(void *tree, git_odb_object *obj);
+
+/**
+ * Lookup the first position in the tree with a given prefix.
+ *
+ * @param tree a previously loaded tree.
+ * @param prefix the beginning of a path to find in the tree.
+ * @return index of the first item at or after the given prefix.
+ */
+int git_tree__prefix_position(const git_tree *tree, const char *prefix);
+
+
+/**
+ * Write a tree to the given repository
+ */
+int git_tree__write_index(
+	git_oid *oid, git_index *index, git_repository *repo);
+
+/**
+ * Obsolete mode kept for compatibility reasons
+ */
+#define GIT_FILEMODE_BLOB_GROUP_WRITABLE 0100664
+
+#endif

vendor/libgit2-sys/libgit2/src/tsort.c

diff --git a/vendor/libgit2-sys/libgit2/src/tsort.c b/vendor/libgit2-sys/libgit2/src/tsort.c
new file mode 100644
index 0000000..8d1ed97
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/tsort.c
@@ -0,0 +1,384 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+/**
+ * An array-of-pointers implementation of Python's Timsort
+ * Based on code by Christopher Swenson under the MIT license
+ *
+ * Copyright (c) 2010 Christopher Swenson
+ * Copyright (c) 2011 Vicent Marti
+ */
+
+#ifndef MAX
+#	define MAX(x,y) (((x) > (y) ? (x) : (y)))
+#endif
+
+#ifndef MIN
+#	define MIN(x,y) (((x) < (y) ? (x) : (y)))
+#endif
+
+static int binsearch(
+	void **dst, const void *x, size_t size, git__sort_r_cmp cmp, void *payload)
+{
+	int l, c, r;
+	void *lx, *cx;
+
+	assert(size > 0);
+
+	l = 0;
+	r = (int)size - 1;
+	c = r >> 1;
+	lx = dst[l];
+
+	/* check for beginning conditions */
+	if (cmp(x, lx, payload) < 0)
+		return 0;
+
+	else if (cmp(x, lx, payload) == 0) {
+		int i = 1;
+		while (cmp(x, dst[i], payload) == 0)
+			i++;
+		return i;
+	}
+
+	/* guaranteed not to be >= rx */
+	cx = dst[c];
+	while (1) {
+		const int val = cmp(x, cx, payload);
+		if (val < 0) {
+			if (c - l <= 1) return c;
+			r = c;
+		} else if (val > 0) {
+			if (r - c <= 1) return c + 1;
+			l = c;
+			lx = cx;
+		} else {
+			do {
+				cx = dst[++c];
+			} while (cmp(x, cx, payload) == 0);
+			return c;
+		}
+		c = l + ((r - l) >> 1);
+		cx = dst[c];
+	}
+}
+
+/* Binary insertion sort, but knowing that the first "start" entries are sorted. Used in timsort. */
+static void bisort(
+	void **dst, size_t start, size_t size, git__sort_r_cmp cmp, void *payload)
+{
+	size_t i;
+	void *x;
+	int location;
+
+	for (i = start; i < size; i++) {
+		int j;
+		/* If this entry is already correct, just move along */
+		if (cmp(dst[i - 1], dst[i], payload) <= 0)
+			continue;
+
+		/* Else we need to find the right place, shift everything over, and squeeze in */
+		x = dst[i];
+		location = binsearch(dst, x, i, cmp, payload);
+		for (j = (int)i - 1; j >= location; j--) {
+			dst[j + 1] = dst[j];
+		}
+		dst[location] = x;
+	}
+}
+
+
+/* timsort implementation, based on timsort.txt */
+struct tsort_run {
+	ssize_t start;
+	ssize_t length;
+};
+
+struct tsort_store {
+	size_t alloc;
+	git__sort_r_cmp cmp;
+	void *payload;
+	void **storage;
+};
+
+static void reverse_elements(void **dst, ssize_t start, ssize_t end)
+{
+	while (start < end) {
+		void *tmp = dst[start];
+		dst[start] = dst[end];
+		dst[end] = tmp;
+
+		start++;
+		end--;
+	}
+}
+
+static ssize_t count_run(
+	void **dst, ssize_t start, ssize_t size, struct tsort_store *store)
+{
+	ssize_t curr = start + 2;
+
+	if (size - start == 1)
+		return 1;
+
+	if (start >= size - 2) {
+		if (store->cmp(dst[size - 2], dst[size - 1], store->payload) > 0) {
+			void *tmp = dst[size - 1];
+			dst[size - 1] = dst[size - 2];
+			dst[size - 2] = tmp;
+		}
+
+		return 2;
+	}
+
+	if (store->cmp(dst[start], dst[start + 1], store->payload) <= 0) {
+		while (curr < size - 1 &&
+				store->cmp(dst[curr - 1], dst[curr], store->payload) <= 0)
+			curr++;
+
+		return curr - start;
+	} else {
+		while (curr < size - 1 &&
+				store->cmp(dst[curr - 1], dst[curr], store->payload) > 0)
+			curr++;
+
+		/* reverse in-place */
+		reverse_elements(dst, start, curr - 1);
+		return curr - start;
+	}
+}
+
+static size_t compute_minrun(size_t n)
+{
+	int r = 0;
+	while (n >= 64) {
+		r |= n & 1;
+		n >>= 1;
+	}
+	return n + r;
+}
+
+static int check_invariant(struct tsort_run *stack, ssize_t stack_curr)
+{
+	if (stack_curr < 2)
+		return 1;
+
+	else if (stack_curr == 2) {
+		const ssize_t A = stack[stack_curr - 2].length;
+		const ssize_t B = stack[stack_curr - 1].length;
+		return (A > B);
+	} else {
+		const ssize_t A = stack[stack_curr - 3].length;
+		const ssize_t B = stack[stack_curr - 2].length;
+		const ssize_t C = stack[stack_curr - 1].length;
+		return !((A <= B + C) || (B <= C));
+	}
+}
+
+static int resize(struct tsort_store *store, size_t new_size)
+{
+	if (store->alloc < new_size) {
+		void **tempstore;
+
+		tempstore = git__reallocarray(store->storage, new_size, sizeof(void *));
+
+		/**
+		 * Do not propagate on OOM; this will abort the sort and
+		 * leave the array unsorted, but no error code will be
+		 * raised
+		 */
+		if (tempstore == NULL)
+			return -1;
+
+		store->storage = tempstore;
+		store->alloc = new_size;
+	}
+
+	return 0;
+}
+
+static void merge(void **dst, const struct tsort_run *stack, ssize_t stack_curr, struct tsort_store *store)
+{
+	const ssize_t A = stack[stack_curr - 2].length;
+	const ssize_t B = stack[stack_curr - 1].length;
+	const ssize_t curr = stack[stack_curr - 2].start;
+
+	void **storage;
+	ssize_t i, j, k;
+
+	if (resize(store, MIN(A, B)) < 0)
+		return;
+
+	storage = store->storage;
+
+	/* left merge */
+	if (A < B) {
+		memcpy(storage, &dst[curr], A * sizeof(void *));
+		i = 0;
+		j = curr + A;
+
+		for (k = curr; k < curr + A + B; k++) {
+			if ((i < A) && (j < curr + A + B)) {
+				if (store->cmp(storage[i], dst[j], store->payload) <= 0)
+					dst[k] = storage[i++];
+				else
+					dst[k] = dst[j++];
+			} else if (i < A) {
+				dst[k] = storage[i++];
+			} else
+				dst[k] = dst[j++];
+		}
+	} else {
+		memcpy(storage, &dst[curr + A], B * sizeof(void *));
+		i = B - 1;
+		j = curr + A - 1;
+
+		for (k = curr + A + B - 1; k >= curr; k--) {
+			if ((i >= 0) && (j >= curr)) {
+				if (store->cmp(dst[j], storage[i], store->payload) > 0)
+					dst[k] = dst[j--];
+				else
+					dst[k] = storage[i--];
+			} else if (i >= 0)
+				dst[k] = storage[i--];
+			else
+				dst[k] = dst[j--];
+		}
+	}
+}
+
+static ssize_t collapse(void **dst, struct tsort_run *stack, ssize_t stack_curr, struct tsort_store *store, ssize_t size)
+{
+	ssize_t A, B, C;
+
+	while (1) {
+		/* if the stack only has one thing on it, we are done with the collapse */
+		if (stack_curr <= 1)
+			break;
+
+		/* if this is the last merge, just do it */
+		if ((stack_curr == 2) && (stack[0].length + stack[1].length == size)) {
+			merge(dst, stack, stack_curr, store);
+			stack[0].length += stack[1].length;
+			stack_curr--;
+			break;
+		}
+
+		/* check if the invariant is off for a stack of 2 elements */
+		else if ((stack_curr == 2) && (stack[0].length <= stack[1].length)) {
+			merge(dst, stack, stack_curr, store);
+			stack[0].length += stack[1].length;
+			stack_curr--;
+			break;
+		}
+		else if (stack_curr == 2)
+			break;
+
+		A = stack[stack_curr - 3].length;
+		B = stack[stack_curr - 2].length;
+		C = stack[stack_curr - 1].length;
+
+		/* check first invariant */
+		if (A <= B + C) {
+			if (A < C) {
+				merge(dst, stack, stack_curr - 1, store);
+				stack[stack_curr - 3].length += stack[stack_curr - 2].length;
+				stack[stack_curr - 2] = stack[stack_curr - 1];
+				stack_curr--;
+			} else {
+				merge(dst, stack, stack_curr, store);
+				stack[stack_curr - 2].length += stack[stack_curr - 1].length;
+				stack_curr--;
+			}
+		} else if (B <= C) {
+			merge(dst, stack, stack_curr, store);
+			stack[stack_curr - 2].length += stack[stack_curr - 1].length;
+			stack_curr--;
+		} else
+			break;
+	}
+
+	return stack_curr;
+}
+
+#define PUSH_NEXT() do {\
+	len = count_run(dst, curr, size, store);\
+	run = minrun;\
+	if (run > (ssize_t)size - curr) run = size - curr;\
+	if (run > len) {\
+		bisort(&dst[curr], len, run, cmp, payload);\
+		len = run;\
+	}\
+	run_stack[stack_curr].start = curr;\
+	run_stack[stack_curr++].length = len;\
+	curr += len;\
+	if (curr == (ssize_t)size) {\
+		/* finish up */ \
+		while (stack_curr > 1) { \
+			merge(dst, run_stack, stack_curr, store); \
+			run_stack[stack_curr - 2].length += run_stack[stack_curr - 1].length; \
+			stack_curr--; \
+		} \
+		if (store->storage != NULL) {\
+			git__free(store->storage);\
+			store->storage = NULL;\
+		}\
+		return;\
+	}\
+}\
+while (0)
+
+void git__tsort_r(
+	void **dst, size_t size, git__sort_r_cmp cmp, void *payload)
+{
+	struct tsort_store _store, *store = &_store;
+	struct tsort_run run_stack[128];
+
+	ssize_t stack_curr = 0;
+	ssize_t len, run;
+	ssize_t curr = 0;
+	ssize_t minrun;
+
+	if (size < 64) {
+		bisort(dst, 1, size, cmp, payload);
+		return;
+	}
+
+	/* compute the minimum run length */
+	minrun = (ssize_t)compute_minrun(size);
+
+	/* temporary storage for merges */
+	store->alloc = 0;
+	store->storage = NULL;
+	store->cmp = cmp;
+	store->payload = payload;
+
+	PUSH_NEXT();
+	PUSH_NEXT();
+	PUSH_NEXT();
+
+	while (1) {
+		if (!check_invariant(run_stack, stack_curr)) {
+			stack_curr = collapse(dst, run_stack, stack_curr, store, size);
+			continue;
+		}
+
+		PUSH_NEXT();
+	}
+}
+
+static int tsort_r_cmp(const void *a, const void *b, void *payload)
+{
+	return ((git__tsort_cmp)payload)(a, b);
+}
+
+void git__tsort(void **dst, size_t size, git__tsort_cmp cmp)
+{
+	git__tsort_r(dst, size, tsort_r_cmp, cmp);
+}

vendor/libgit2-sys/libgit2/src/unix/map.c

diff --git a/vendor/libgit2-sys/libgit2/src/unix/map.c b/vendor/libgit2-sys/libgit2/src/unix/map.c
new file mode 100644
index 0000000..8a07fcf
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/unix/map.c
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "git2/common.h"
+
+#if !defined(GIT_WIN32) && !defined(NO_MMAP)
+
+#include "map.h"
+#include <sys/mman.h>
+#include <unistd.h>
+#include <errno.h>
+
+int git__page_size(size_t *page_size)
+{
+	long sc_page_size = sysconf(_SC_PAGE_SIZE);
+	if (sc_page_size < 0) {
+		giterr_set(GITERR_OS, "can't determine system page size");
+		return -1;
+	}
+	*page_size = (size_t) sc_page_size;
+	return 0;
+}
+
+int git__mmap_alignment(size_t *alignment)
+{
+  return git__page_size(alignment);
+}
+
+int p_mmap(git_map *out, size_t len, int prot, int flags, int fd, git_off_t offset)
+{
+	int mprot = PROT_READ;
+	int mflag = 0;
+
+	GIT_MMAP_VALIDATE(out, len, prot, flags);
+
+	out->data = NULL;
+	out->len = 0;
+
+	if (prot & GIT_PROT_WRITE)
+		mprot |= PROT_WRITE;
+
+	if ((flags & GIT_MAP_TYPE) == GIT_MAP_SHARED)
+		mflag = MAP_SHARED;
+	else if ((flags & GIT_MAP_TYPE) == GIT_MAP_PRIVATE)
+		mflag = MAP_PRIVATE;
+	else
+		mflag = MAP_SHARED;
+
+	out->data = mmap(NULL, len, mprot, mflag, fd, offset);
+
+	if (!out->data || out->data == MAP_FAILED) {
+		giterr_set(GITERR_OS, "failed to mmap. Could not write data");
+		return -1;
+	}
+
+	out->len = len;
+
+	return 0;
+}
+
+int p_munmap(git_map *map)
+{
+	assert(map != NULL);
+	munmap(map->data, map->len);
+
+	return 0;
+}
+
+#endif
+

vendor/libgit2-sys/libgit2/src/unix/posix.h

diff --git a/vendor/libgit2-sys/libgit2/src/unix/posix.h b/vendor/libgit2-sys/libgit2/src/unix/posix.h
new file mode 100644
index 0000000..f2fffd5
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/unix/posix.h
@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_unix_posix_h__
+#define INCLUDE_unix_posix_h__
+
+#ifndef LIBGIT2_NO_FEATURES_H
+# include "git2/sys/features.h"
+#endif
+
+#include <stdio.h>
+#include <dirent.h>
+#include <sys/param.h>
+#include <sys/time.h>
+#include <sys/stat.h>
+
+typedef int GIT_SOCKET;
+#define INVALID_SOCKET -1
+
+#define p_lseek(f,n,w) lseek(f, n, w)
+#define p_fstat(f,b) fstat(f, b)
+#define p_lstat(p,b) lstat(p,b)
+#define p_stat(p,b) stat(p, b)
+
+#if defined(GIT_USE_STAT_MTIMESPEC)
+# define st_atime_nsec st_atimespec.tv_nsec
+# define st_mtime_nsec st_mtimespec.tv_nsec
+# define st_ctime_nsec st_ctimespec.tv_nsec
+#elif defined(GIT_USE_STAT_MTIM)
+# define st_atime_nsec st_atim.tv_nsec
+# define st_mtime_nsec st_mtim.tv_nsec
+# define st_ctime_nsec st_ctim.tv_nsec
+#elif !defined(GIT_USE_STAT_MTIME_NSEC) && defined(GIT_USE_NEC)
+# error GIT_USE_NSEC defined but unknown struct stat nanosecond type
+#endif
+
+#define p_utimes(f, t) utimes(f, t)
+
+#define p_readlink(a, b, c) readlink(a, b, c)
+#define p_symlink(o,n) symlink(o, n)
+#define p_link(o,n) link(o, n)
+#define p_unlink(p) unlink(p)
+#define p_mkdir(p,m) mkdir(p, m)
+extern char *p_realpath(const char *, char *);
+
+GIT_INLINE(int) p_fsync(int fd)
+{
+	p_fsync__cnt++;
+	return fsync(fd);
+}
+
+#define p_recv(s,b,l,f) recv(s,b,l,f)
+#define p_send(s,b,l,f) send(s,b,l,f)
+#define p_inet_pton(a, b, c) inet_pton(a, b, c)
+
+#define p_strcasecmp(s1, s2) strcasecmp(s1, s2)
+#define p_strncasecmp(s1, s2, c) strncasecmp(s1, s2, c)
+#define p_vsnprintf(b, c, f, a) vsnprintf(b, c, f, a)
+#define p_snprintf(b, c, ...) snprintf(b, c, __VA_ARGS__)
+#define p_mkstemp(p) mkstemp(p)
+#define p_chdir(p) chdir(p)
+#define p_chmod(p,m) chmod(p, m)
+#define p_rmdir(p) rmdir(p)
+#define p_access(p,m) access(p,m)
+#define p_ftruncate(fd, sz) ftruncate(fd, sz)
+
+/* see win32/posix.h for explanation about why this exists */
+#define p_lstat_posixly(p,b) lstat(p,b)
+
+#define p_localtime_r(c, r) localtime_r(c, r)
+#define p_gmtime_r(c, r) gmtime_r(c, r)
+
+#define p_timeval timeval
+
+#ifdef GIT_USE_FUTIMENS
+GIT_INLINE(int) p_futimes(int f, const struct p_timeval t[2])
+{
+	struct timespec s[2];
+	s[0].tv_sec = t[0].tv_sec;
+	s[0].tv_nsec = t[0].tv_usec * 1000;
+	s[1].tv_sec = t[1].tv_sec;
+	s[1].tv_nsec = t[1].tv_usec * 1000;
+	return futimens(f, s);
+}
+#else
+# define p_futimes futimes
+#endif
+
+#ifdef GIT_USE_REGCOMP_L
+#include <xlocale.h>
+GIT_INLINE(int) p_regcomp(regex_t *preg, const char *pattern, int cflags)
+{
+	return regcomp_l(preg, pattern, cflags, (locale_t) 0);
+}
+#else
+# define p_regcomp regcomp
+#endif
+
+#endif

vendor/libgit2-sys/libgit2/src/unix/pthread.h

diff --git a/vendor/libgit2-sys/libgit2/src/unix/pthread.h b/vendor/libgit2-sys/libgit2/src/unix/pthread.h
new file mode 100644
index 0000000..233561b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/unix/pthread.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_unix_pthread_h__
+#define INCLUDE_unix_pthread_h__
+
+typedef struct {
+	pthread_t thread;
+} git_thread;
+
+#define git_threads_init() (void)0
+#define git_thread_create(git_thread_ptr, start_routine, arg) \
+	pthread_create(&(git_thread_ptr)->thread, NULL, start_routine, arg)
+#define git_thread_join(git_thread_ptr, status) \
+	pthread_join((git_thread_ptr)->thread, status)
+#define git_thread_currentid() ((size_t)(pthread_self()))
+#define git_thread_exit(retval) pthread_exit(retval)
+
+/* Git Mutex */
+#define git_mutex pthread_mutex_t
+#define git_mutex_init(a)	pthread_mutex_init(a, NULL)
+#define git_mutex_lock(a)	pthread_mutex_lock(a)
+#define git_mutex_unlock(a)     pthread_mutex_unlock(a)
+#define git_mutex_free(a)	pthread_mutex_destroy(a)
+
+/* Git condition vars */
+#define git_cond pthread_cond_t
+#define git_cond_init(c)	pthread_cond_init(c, NULL)
+#define git_cond_free(c) 	pthread_cond_destroy(c)
+#define git_cond_wait(c, l)	pthread_cond_wait(c, l)
+#define git_cond_signal(c)	pthread_cond_signal(c)
+#define git_cond_broadcast(c)	pthread_cond_broadcast(c)
+
+/* Pthread (-ish) rwlock
+ *
+ * This differs from normal pthreads rwlocks in two ways:
+ * 1. Separate APIs for releasing read locks and write locks (as
+ *    opposed to the pure POSIX API which only has one unlock fn)
+ * 2. You should not use recursive read locks (i.e. grabbing a read
+ *    lock in a thread that already holds a read lock) because the
+ *    Windows implementation doesn't support it
+ */
+#define git_rwlock              pthread_rwlock_t
+#define git_rwlock_init(a)	pthread_rwlock_init(a, NULL)
+#define git_rwlock_rdlock(a)	pthread_rwlock_rdlock(a)
+#define git_rwlock_rdunlock(a)	pthread_rwlock_unlock(a)
+#define git_rwlock_wrlock(a)	pthread_rwlock_wrlock(a)
+#define git_rwlock_wrunlock(a)	pthread_rwlock_unlock(a)
+#define git_rwlock_free(a)	pthread_rwlock_destroy(a)
+#define GIT_RWLOCK_STATIC_INIT	PTHREAD_RWLOCK_INITIALIZER
+
+#endif

vendor/libgit2-sys/libgit2/src/unix/realpath.c

diff --git a/vendor/libgit2-sys/libgit2/src/unix/realpath.c b/vendor/libgit2-sys/libgit2/src/unix/realpath.c
new file mode 100644
index 0000000..893bac8
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/unix/realpath.c
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "git2/common.h"
+
+#ifndef GIT_WIN32
+
+#include <limits.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+char *p_realpath(const char *pathname, char *resolved)
+{
+	char *ret;
+	if ((ret = realpath(pathname, resolved)) == NULL)
+		return NULL;
+
+#ifdef __OpenBSD__
+	/* The OpenBSD realpath function behaves differently,
+	 * figure out if the file exists */
+	if (access(ret, F_OK) < 0)
+		ret = NULL;
+#endif
+	return ret;
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/userdiff.h

diff --git a/vendor/libgit2-sys/libgit2/src/userdiff.h b/vendor/libgit2-sys/libgit2/src/userdiff.h
new file mode 100644
index 0000000..91c1f42
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/userdiff.h
@@ -0,0 +1,208 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_userdiff_h__
+#define INCLUDE_userdiff_h__
+
+/*
+ * This file isolates the built in diff driver function name patterns.
+ * Most of these patterns are taken from Git (with permission from the
+ * original authors for relicensing to libgit2).
+ */
+
+typedef struct {
+	const char *name;
+	const char *fns;
+	const char *words;
+	int flags;
+} git_diff_driver_definition;
+
+#define WORD_DEFAULT "|[^[:space:]]|[\xc0-\xff][\x80-\xbf]+"
+
+/*
+ * These builtin driver definition macros have same signature as in core
+ * git userdiff.c so that the data can be extracted verbatim
+ */
+#define PATTERNS(NAME, FN_PATS, WORD_PAT) \
+	{ NAME, FN_PATS, WORD_PAT WORD_DEFAULT, 0 }
+#define IPATTERN(NAME, FN_PATS, WORD_PAT) \
+	{ NAME, FN_PATS, WORD_PAT WORD_DEFAULT, REG_ICASE }
+
+/*
+ * The table of diff driver patterns
+ *
+ * Function name patterns are a list of newline separated patterns that
+ * match a function declaration (i.e. the line you want in the hunk header),
+ * or a negative pattern prefixed with a '!' to reject a pattern (such as
+ * rejecting goto labels in C code).
+ *
+ * Word boundary patterns are just a simple pattern that will be OR'ed with
+ * the default value above (i.e. whitespace or non-ASCII characters).
+ */
+static git_diff_driver_definition builtin_defs[] = {
+
+IPATTERN("ada",
+	 "!^(.*[ \t])?(is[ \t]+new|renames|is[ \t]+separate)([ \t].*)?$\n"
+	 "!^[ \t]*with[ \t].*$\n"
+	 "^[ \t]*((procedure|function)[ \t]+.*)$\n"
+	 "^[ \t]*((package|protected|task)[ \t]+.*)$",
+	 /* -- */
+	 "[a-zA-Z][a-zA-Z0-9_]*"
+	 "|[-+]?[0-9][0-9#_.aAbBcCdDeEfF]*([eE][+-]?[0-9_]+)?"
+	 "|=>|\\.\\.|\\*\\*|:=|/=|>=|<=|<<|>>|<>"),
+
+IPATTERN("fortran",
+	 "!^([C*]|[ \t]*!)\n"
+	 "!^[ \t]*MODULE[ \t]+PROCEDURE[ \t]\n"
+	 "^[ \t]*((END[ \t]+)?(PROGRAM|MODULE|BLOCK[ \t]+DATA"
+		"|([^'\" \t]+[ \t]+)*(SUBROUTINE|FUNCTION))[ \t]+[A-Z].*)$",
+	 /* -- */
+	 "[a-zA-Z][a-zA-Z0-9_]*"
+	 "|\\.([Ee][Qq]|[Nn][Ee]|[Gg][TtEe]|[Ll][TtEe]|[Tt][Rr][Uu][Ee]|[Ff][Aa][Ll][Ss][Ee]|[Aa][Nn][Dd]|[Oo][Rr]|[Nn]?[Ee][Qq][Vv]|[Nn][Oo][Tt])\\."
+	 /* numbers and format statements like 2E14.4, or ES12.6, 9X.
+	  * Don't worry about format statements without leading digits since
+	  * they would have been matched above as a variable anyway. */
+	 "|[-+]?[0-9.]+([AaIiDdEeFfLlTtXx][Ss]?[-+]?[0-9.]*)?(_[a-zA-Z0-9][a-zA-Z0-9_]*)?"
+	 "|//|\\*\\*|::|[/<>=]="),
+
+PATTERNS("html", "^[ \t]*(<[Hh][1-6][ \t].*>.*)$",
+	 "[^<>= \t]+"),
+
+PATTERNS("java",
+	 "!^[ \t]*(catch|do|for|if|instanceof|new|return|switch|throw|while)\n"
+	 "^[ \t]*(([A-Za-z_][A-Za-z_0-9]*[ \t]+)+[A-Za-z_][A-Za-z_0-9]*[ \t]*\\([^;]*)$",
+	 /* -- */
+	 "[a-zA-Z_][a-zA-Z0-9_]*"
+	 "|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?"
+	 "|[-+*/<>%&^|=!]="
+	 "|--|\\+\\+|<<=?|>>>?=?|&&|\\|\\|"),
+
+PATTERNS("matlab",
+	 "^[[:space:]]*((classdef|function)[[:space:]].*)$|^%%[[:space:]].*$",
+	 "[a-zA-Z_][a-zA-Z0-9_]*|[-+0-9.e]+|[=~<>]=|\\.[*/\\^']|\\|\\||&&"),
+
+PATTERNS("objc",
+	 /* Negate C statements that can look like functions */
+	 "!^[ \t]*(do|for|if|else|return|switch|while)\n"
+	 /* Objective-C methods */
+	 "^[ \t]*([-+][ \t]*\\([ \t]*[A-Za-z_][A-Za-z_0-9* \t]*\\)[ \t]*[A-Za-z_].*)$\n"
+	 /* C functions */
+	 "^[ \t]*(([A-Za-z_][A-Za-z_0-9]*[ \t]+)+[A-Za-z_][A-Za-z_0-9]*[ \t]*\\([^;]*)$\n"
+	 /* Objective-C class/protocol definitions */
+	 "^(@(implementation|interface|protocol)[ \t].*)$",
+	 /* -- */
+	 "[a-zA-Z_][a-zA-Z0-9_]*"
+	 "|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?"
+	 "|[-+*/<>%&^|=!]=|--|\\+\\+|<<=?|>>=?|&&|\\|\\||::|->"),
+
+PATTERNS("pascal",
+	 "^(((class[ \t]+)?(procedure|function)|constructor|destructor|interface|"
+		"implementation|initialization|finalization)[ \t]*.*)$"
+	 "\n"
+	 "^(.*=[ \t]*(class|record).*)$",
+	 /* -- */
+	 "[a-zA-Z_][a-zA-Z0-9_]*"
+	 "|[-+0-9.e]+|0[xXbB]?[0-9a-fA-F]+"
+	 "|<>|<=|>=|:=|\\.\\."),
+
+PATTERNS("perl",
+	 "^package .*\n"
+	 "^sub [[:alnum:]_':]+[ \t]*"
+		"(\\([^)]*\\)[ \t]*)?" /* prototype */
+		/*
+		 * Attributes.  A regex can't count nested parentheses,
+		 * so just slurp up whatever we see, taking care not
+		 * to accept lines like "sub foo; # defined elsewhere".
+		 *
+		 * An attribute could contain a semicolon, but at that
+		 * point it seems reasonable enough to give up.
+		 */
+		"(:[^;#]*)?"
+		"(\\{[ \t]*)?" /* brace can come here or on the next line */
+		"(#.*)?$\n" /* comment */
+	 "^(BEGIN|END|INIT|CHECK|UNITCHECK|AUTOLOAD|DESTROY)[ \t]*"
+		"(\\{[ \t]*)?" /* brace can come here or on the next line */
+		"(#.*)?$\n"
+	 "^=head[0-9] .*",	/* POD */
+	 /* -- */
+	 "[[:alpha:]_'][[:alnum:]_']*"
+	 "|0[xb]?[0-9a-fA-F_]*"
+	 /* taking care not to interpret 3..5 as (3.)(.5) */
+	 "|[0-9a-fA-F_]+(\\.[0-9a-fA-F_]+)?([eE][-+]?[0-9_]+)?"
+	 "|=>|-[rwxoRWXOezsfdlpSugkbctTBMAC>]|~~|::"
+	 "|&&=|\\|\\|=|//=|\\*\\*="
+	 "|&&|\\|\\||//|\\+\\+|--|\\*\\*|\\.\\.\\.?"
+	 "|[-+*/%.^&<>=!|]="
+	 "|=~|!~"
+	 "|<<|<>|<=>|>>"),
+
+PATTERNS("python", "^[ \t]*((class|def)[ \t].*)$",
+	 /* -- */
+	 "[a-zA-Z_][a-zA-Z0-9_]*"
+	 "|[-+0-9.e]+[jJlL]?|0[xX]?[0-9a-fA-F]+[lL]?"
+	 "|[-+*/<>%&^|=!]=|//=?|<<=?|>>=?|\\*\\*=?"),
+
+PATTERNS("ruby", "^[ \t]*((class|module|def)[ \t].*)$",
+	 /* -- */
+	 "(@|@@|\\$)?[a-zA-Z_][a-zA-Z0-9_]*"
+	 "|[-+0-9.e]+|0[xXbB]?[0-9a-fA-F]+|\\?(\\\\C-)?(\\\\M-)?."
+	 "|//=?|[-+*/<>%&^|=!]=|<<=?|>>=?|===|\\.{1,3}|::|[!=]~"),
+
+PATTERNS("bibtex", "(@[a-zA-Z]{1,}[ \t]*\\{{0,1}[ \t]*[^ \t\"@',\\#}{~%]*).*$",
+	 "[={}\"]|[^={}\" \t]+"),
+
+PATTERNS("tex", "^(\\\\((sub)*section|chapter|part)\\*{0,1}\\{.*)$",
+	 "\\\\[a-zA-Z@]+|\\\\.|[a-zA-Z0-9\x80-\xff]+"),
+
+PATTERNS("cpp",
+	 /* Jump targets or access declarations */
+	 "!^[ \t]*[A-Za-z_][A-Za-z_0-9]*:[[:space:]]*($|/[/*])\n"
+	 /* functions/methods, variables, and compounds at top level */
+	 "^((::[[:space:]]*)?[A-Za-z_].*)$",
+	 /* -- */
+	 "[a-zA-Z_][a-zA-Z0-9_]*"
+	 "|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lLuU]*"
+	 "|[-+*/<>%&^|=!]=|--|\\+\\+|<<=?|>>=?|&&|\\|\\||::|->\\*?|\\.\\*"),
+
+PATTERNS("csharp",
+	 /* Keywords */
+	 "!^[ \t]*(do|while|for|if|else|instanceof|new|return|switch|case|throw|catch|using)\n"
+	 /* Methods and constructors */
+	 "^[ \t]*(((static|public|internal|private|protected|new|virtual|sealed|override|unsafe)[ \t]+)*[][<>@.~_[:alnum:]]+[ \t]+[<>@._[:alnum:]]+[ \t]*\\(.*\\))[ \t]*$\n"
+	 /* Properties */
+	 "^[ \t]*(((static|public|internal|private|protected|new|virtual|sealed|override|unsafe)[ \t]+)*[][<>@.~_[:alnum:]]+[ \t]+[@._[:alnum:]]+)[ \t]*$\n"
+	 /* Type definitions */
+	 "^[ \t]*(((static|public|internal|private|protected|new|unsafe|sealed|abstract|partial)[ \t]+)*(class|enum|interface|struct)[ \t]+.*)$\n"
+	 /* Namespace */
+	 "^[ \t]*(namespace[ \t]+.*)$",
+	 /* -- */
+	 "[a-zA-Z_][a-zA-Z0-9_]*"
+	 "|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?"
+	 "|[-+*/<>%&^|=!]=|--|\\+\\+|<<=?|>>=?|&&|\\|\\||::|->"),
+
+PATTERNS("php",
+	 "^[ \t]*(((public|private|protected|static|final)[ \t]+)*((class|function)[ \t].*))$",
+	 /* -- */
+	 "[a-zA-Z_][a-zA-Z0-9_]*"
+	 "|[-+0-9.e]+[fFlL]?|0[xX]?[0-9a-fA-F]+[lL]?"
+	 "|[-+*/<>%&^|=!]=|--|\\+\\+|<<=?|>>=?|&&|\\|\\||::|->"),
+
+PATTERNS("javascript",
+	 "([a-zA-Z_$][a-zA-Z0-9_$]*(\\.[a-zA-Z0-9_$]+)*[ \t]*=[ \t]*function([ \t][a-zA-Z_$][a-zA-Z0-9_$]*)?[^\\{]*)\n"
+	 "([a-zA-Z_$][a-zA-Z0-9_$]*[ \t]*:[ \t]*function([ \t][a-zA-Z_$][a-zA-Z0-9_$]*)?[^\\{]*)\n"
+	 "[^a-zA-Z0-9_\\$](function([ \t][a-zA-Z_$][a-zA-Z0-9_$]*)?[^\\{]*)",
+	 /* -- */
+	 "[a-zA-Z_][a-zA-Z0-9_]*"
+	 "|[-+0-9.e]+[fFlL]?|0[xX]?[0-9a-fA-F]+[lL]?"
+	 "|[-+*/<>%&^|=!]=|--|\\+\\+|<<=?|>>=?|&&|\\|\\||::|->"),
+};
+
+#undef IPATTERN
+#undef PATTERNS
+#undef WORD_DEFAULT
+
+#endif
+

vendor/libgit2-sys/libgit2/src/util.c

diff --git a/vendor/libgit2-sys/libgit2/src/util.c b/vendor/libgit2-sys/libgit2/src/util.c
new file mode 100644
index 0000000..bf778a9
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/util.c
@@ -0,0 +1,867 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "util.h"
+
+#include "common.h"
+
+#ifdef GIT_WIN32
+# include "win32/utf-conv.h"
+# include "win32/w32_buffer.h"
+
+# ifdef HAVE_QSORT_S
+#  include <search.h>
+# endif
+#endif
+
+#ifdef _MSC_VER
+# include <Shlwapi.h>
+#endif
+
+void git_strarray_free(git_strarray *array)
+{
+	size_t i;
+
+	if (array == NULL)
+		return;
+
+	for (i = 0; i < array->count; ++i)
+		git__free(array->strings[i]);
+
+	git__free(array->strings);
+
+	memset(array, 0, sizeof(*array));
+}
+
+int git_strarray_copy(git_strarray *tgt, const git_strarray *src)
+{
+	size_t i;
+
+	assert(tgt && src);
+
+	memset(tgt, 0, sizeof(*tgt));
+
+	if (!src->count)
+		return 0;
+
+	tgt->strings = git__calloc(src->count, sizeof(char *));
+	GITERR_CHECK_ALLOC(tgt->strings);
+
+	for (i = 0; i < src->count; ++i) {
+		if (!src->strings[i])
+			continue;
+
+		tgt->strings[tgt->count] = git__strdup(src->strings[i]);
+		if (!tgt->strings[tgt->count]) {
+			git_strarray_free(tgt);
+			memset(tgt, 0, sizeof(*tgt));
+			return -1;
+		}
+
+		tgt->count++;
+	}
+
+	return 0;
+}
+
+int git__strtol64(int64_t *result, const char *nptr, const char **endptr, int base)
+{
+
+	return git__strntol64(result, nptr, (size_t)-1, endptr, base);
+}
+
+int git__strntol64(int64_t *result, const char *nptr, size_t nptr_len, const char **endptr, int base)
+{
+	const char *p;
+	int64_t n, nn;
+	int c, ovfl, v, neg, ndig;
+
+	p = nptr;
+	neg = 0;
+	n = 0;
+	ndig = 0;
+	ovfl = 0;
+
+	/*
+	 * White space
+	 */
+	while (git__isspace(*p))
+		p++;
+
+	/*
+	 * Sign
+	 */
+	if (*p == '-' || *p == '+')
+		if (*p++ == '-')
+			neg = 1;
+
+	/*
+	 * Base
+	 */
+	if (base == 0) {
+		if (*p != '0')
+			base = 10;
+		else {
+			base = 8;
+			if (p[1] == 'x' || p[1] == 'X') {
+				p += 2;
+				base = 16;
+			}
+		}
+	} else if (base == 16 && *p == '0') {
+		if (p[1] == 'x' || p[1] == 'X')
+			p += 2;
+	} else if (base < 0 || 36 < base)
+		goto Return;
+
+	/*
+	 * Non-empty sequence of digits
+	 */
+	for (; nptr_len > 0; p++,ndig++,nptr_len--) {
+		c = *p;
+		v = base;
+		if ('0'<=c && c<='9')
+			v = c - '0';
+		else if ('a'<=c && c<='z')
+			v = c - 'a' + 10;
+		else if ('A'<=c && c<='Z')
+			v = c - 'A' + 10;
+		if (v >= base)
+			break;
+		nn = n * base + (neg ? -v : v);
+		if ((!neg && nn < n) || (neg && nn > n))
+			ovfl = 1;
+		n = nn;
+	}
+
+Return:
+	if (ndig == 0) {
+		giterr_set(GITERR_INVALID, "failed to convert string to long: not a number");
+		return -1;
+	}
+
+	if (endptr)
+		*endptr = p;
+
+	if (ovfl) {
+		giterr_set(GITERR_INVALID, "failed to convert string to long: overflow error");
+		return -1;
+	}
+
+	*result = n;
+	return 0;
+}
+
+int git__strtol32(int32_t *result, const char *nptr, const char **endptr, int base)
+{
+
+	return git__strntol32(result, nptr, (size_t)-1, endptr, base);
+}
+
+int git__strntol32(int32_t *result, const char *nptr, size_t nptr_len, const char **endptr, int base)
+{
+	int error;
+	int32_t tmp_int;
+	int64_t tmp_long;
+
+	if ((error = git__strntol64(&tmp_long, nptr, nptr_len, endptr, base)) < 0)
+		return error;
+
+	tmp_int = tmp_long & 0xFFFFFFFF;
+	if (tmp_int != tmp_long) {
+		giterr_set(GITERR_INVALID, "failed to convert: '%s' is too large", nptr);
+		return -1;
+	}
+
+	*result = tmp_int;
+
+	return error;
+}
+
+int git__strcmp(const char *a, const char *b)
+{
+	while (*a && *b && *a == *b)
+		++a, ++b;
+	return (int)(*(const unsigned char *)a) - (int)(*(const unsigned char *)b);
+}
+
+int git__strcasecmp(const char *a, const char *b)
+{
+	while (*a && *b && git__tolower(*a) == git__tolower(*b))
+		++a, ++b;
+	return ((unsigned char)git__tolower(*a) - (unsigned char)git__tolower(*b));
+}
+
+int git__strcasesort_cmp(const char *a, const char *b)
+{
+	int cmp = 0;
+
+	while (*a && *b) {
+		if (*a != *b) {
+			if (git__tolower(*a) != git__tolower(*b))
+				break;
+			/* use case in sort order even if not in equivalence */
+			if (!cmp)
+				cmp = (int)(*(const uint8_t *)a) - (int)(*(const uint8_t *)b);
+		}
+
+		++a, ++b;
+	}
+
+	if (*a || *b)
+		return (unsigned char)git__tolower(*a) - (unsigned char)git__tolower(*b);
+
+	return cmp;
+}
+
+int git__strncmp(const char *a, const char *b, size_t sz)
+{
+	while (sz && *a && *b && *a == *b)
+		--sz, ++a, ++b;
+	if (!sz)
+		return 0;
+	return (int)(*(const unsigned char *)a) - (int)(*(const unsigned char *)b);
+}
+
+int git__strncasecmp(const char *a, const char *b, size_t sz)
+{
+	int al, bl;
+
+	do {
+		al = (unsigned char)git__tolower(*a);
+		bl = (unsigned char)git__tolower(*b);
+		++a, ++b;
+	} while (--sz && al && al == bl);
+
+	return al - bl;
+}
+
+void git__strntolower(char *str, size_t len)
+{
+	size_t i;
+
+	for (i = 0; i < len; ++i) {
+		str[i] = (char)git__tolower(str[i]);
+	}
+}
+
+void git__strtolower(char *str)
+{
+	git__strntolower(str, strlen(str));
+}
+
+GIT_INLINE(int) prefixcmp(const char *str, size_t str_n, const char *prefix, bool icase)
+{
+	int s, p;
+
+	while (str_n--) {
+		s = (unsigned char)*str++;
+		p = (unsigned char)*prefix++;
+
+		if (icase) {
+			s = git__tolower(s);
+			p = git__tolower(p);
+		}
+
+		if (!p)
+			return 0;
+
+		if (s != p)
+			return s - p;
+	}
+
+	return (0 - *prefix);
+}
+
+int git__prefixcmp(const char *str, const char *prefix)
+{
+	return prefixcmp(str, SIZE_MAX, prefix, false);
+}
+
+int git__prefixncmp(const char *str, size_t str_n, const char *prefix)
+{
+	return prefixcmp(str, str_n, prefix, false);
+}
+
+int git__prefixcmp_icase(const char *str, const char *prefix)
+{
+	return prefixcmp(str, SIZE_MAX, prefix, true);
+}
+
+int git__prefixncmp_icase(const char *str, size_t str_n, const char *prefix)
+{
+	return prefixcmp(str, str_n, prefix, true);
+}
+
+int git__suffixcmp(const char *str, const char *suffix)
+{
+	size_t a = strlen(str);
+	size_t b = strlen(suffix);
+	if (a < b)
+		return -1;
+	return strcmp(str + (a - b), suffix);
+}
+
+char *git__strtok(char **end, const char *sep)
+{
+	char *ptr = *end;
+
+	while (*ptr && strchr(sep, *ptr))
+		++ptr;
+
+	if (*ptr) {
+		char *start = ptr;
+		*end = start + 1;
+
+		while (**end && !strchr(sep, **end))
+			++*end;
+
+		if (**end) {
+			**end = '\0';
+			++*end;
+		}
+
+		return start;
+	}
+
+	return NULL;
+}
+
+/* Similar to strtok, but does not collapse repeated tokens. */
+char *git__strsep(char **end, const char *sep)
+{
+	char *start = *end, *ptr = *end;
+
+	while (*ptr && !strchr(sep, *ptr))
+		++ptr;
+
+	if (*ptr) {
+		*end = ptr + 1;
+		*ptr = '\0';
+
+		return start;
+	}
+
+	return NULL;
+}
+
+size_t git__linenlen(const char *buffer, size_t buffer_len)
+{
+	char *nl = memchr(buffer, '\n', buffer_len);
+	return nl ? (size_t)(nl - buffer) + 1 : buffer_len;
+}
+
+void git__hexdump(const char *buffer, size_t len)
+{
+	static const size_t LINE_WIDTH = 16;
+
+	size_t line_count, last_line, i, j;
+	const char *line;
+
+	line_count = (len / LINE_WIDTH);
+	last_line = (len % LINE_WIDTH);
+
+	for (i = 0; i < line_count; ++i) {
+		line = buffer + (i * LINE_WIDTH);
+		for (j = 0; j < LINE_WIDTH; ++j, ++line)
+			printf("%02X ", (unsigned char)*line & 0xFF);
+
+		printf("| ");
+
+		line = buffer + (i * LINE_WIDTH);
+		for (j = 0; j < LINE_WIDTH; ++j, ++line)
+			printf("%c", (*line >= 32 && *line <= 126) ? *line : '.');
+
+		printf("\n");
+	}
+
+	if (last_line > 0) {
+
+		line = buffer + (line_count * LINE_WIDTH);
+		for (j = 0; j < last_line; ++j, ++line)
+			printf("%02X ", (unsigned char)*line & 0xFF);
+
+		for (j = 0; j < (LINE_WIDTH - last_line); ++j)
+			printf("	");
+
+		printf("| ");
+
+		line = buffer + (line_count * LINE_WIDTH);
+		for (j = 0; j < last_line; ++j, ++line)
+			printf("%c", (*line >= 32 && *line <= 126) ? *line : '.');
+
+		printf("\n");
+	}
+
+	printf("\n");
+}
+
+#ifdef GIT_LEGACY_HASH
+uint32_t git__hash(const void *key, int len, unsigned int seed)
+{
+	const uint32_t m = 0x5bd1e995;
+	const int r = 24;
+	uint32_t h = seed ^ len;
+
+	const unsigned char *data = (const unsigned char *)key;
+
+	while(len >= 4) {
+		uint32_t k = *(uint32_t *)data;
+
+		k *= m;
+		k ^= k >> r;
+		k *= m;
+
+		h *= m;
+		h ^= k;
+
+		data += 4;
+		len -= 4;
+	}
+
+	switch(len) {
+	case 3: h ^= data[2] << 16;
+	case 2: h ^= data[1] << 8;
+	case 1: h ^= data[0];
+			h *= m;
+	};
+
+	h ^= h >> 13;
+	h *= m;
+	h ^= h >> 15;
+
+	return h;
+}
+#else
+/*
+	Cross-platform version of Murmurhash3
+	http://code.google.com/p/smhasher/wiki/MurmurHash3
+	by Austin Appleby (aappleby@gmail.com)
+
+	This code is on the public domain.
+*/
+uint32_t git__hash(const void *key, int len, uint32_t seed)
+{
+
+#define MURMUR_BLOCK() {\
+	k1 *= c1; \
+	k1 = git__rotl(k1,11);\
+	k1 *= c2;\
+	h1 ^= k1;\
+	h1 = h1*3 + 0x52dce729;\
+	c1 = c1*5 + 0x7b7d159c;\
+	c2 = c2*5 + 0x6bce6396;\
+}
+
+	const uint8_t *data = (const uint8_t*)key;
+	const int nblocks = len / 4;
+
+	const uint32_t *blocks = (const uint32_t *)(data + nblocks * 4);
+	const uint8_t *tail = (const uint8_t *)(data + nblocks * 4);
+
+	uint32_t h1 = 0x971e137b ^ seed;
+	uint32_t k1;
+
+	uint32_t c1 = 0x95543787;
+	uint32_t c2 = 0x2ad7eb25;
+
+	int i;
+
+	for (i = -nblocks; i; i++) {
+		k1 = blocks[i];
+		MURMUR_BLOCK();
+	}
+
+	k1 = 0;
+
+	switch(len & 3) {
+	case 3: k1 ^= tail[2] << 16;
+		/* fall through */
+	case 2: k1 ^= tail[1] << 8;
+		/* fall through */
+	case 1: k1 ^= tail[0];
+		MURMUR_BLOCK();
+	}
+
+	h1 ^= len;
+	h1 ^= h1 >> 16;
+	h1 *= 0x85ebca6b;
+	h1 ^= h1 >> 13;
+	h1 *= 0xc2b2ae35;
+	h1 ^= h1 >> 16;
+
+	return h1;
+}
+#endif
+
+/**
+ * A modified `bsearch` from the BSD glibc.
+ *
+ * Copyright (c) 1990 Regents of the University of California.
+ * All rights reserved.
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. [rescinded 22 July 1999]
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+int git__bsearch(
+	void **array,
+	size_t array_len,
+	const void *key,
+	int (*compare)(const void *, const void *),
+	size_t *position)
+{
+	size_t lim;
+	int cmp = -1;
+	void **part, **base = array;
+
+	for (lim = array_len; lim != 0; lim >>= 1) {
+		part = base + (lim >> 1);
+		cmp = (*compare)(key, *part);
+		if (cmp == 0) {
+			base = part;
+			break;
+		}
+		if (cmp > 0) { /* key > p; take right partition */
+			base = part + 1;
+			lim--;
+		} /* else take left partition */
+	}
+
+	if (position)
+		*position = (base - array);
+
+	return (cmp == 0) ? 0 : GIT_ENOTFOUND;
+}
+
+int git__bsearch_r(
+	void **array,
+	size_t array_len,
+	const void *key,
+	int (*compare_r)(const void *, const void *, void *),
+	void *payload,
+	size_t *position)
+{
+	size_t lim;
+	int cmp = -1;
+	void **part, **base = array;
+
+	for (lim = array_len; lim != 0; lim >>= 1) {
+		part = base + (lim >> 1);
+		cmp = (*compare_r)(key, *part, payload);
+		if (cmp == 0) {
+			base = part;
+			break;
+		}
+		if (cmp > 0) { /* key > p; take right partition */
+			base = part + 1;
+			lim--;
+		} /* else take left partition */
+	}
+
+	if (position)
+		*position = (base - array);
+
+	return (cmp == 0) ? 0 : GIT_ENOTFOUND;
+}
+
+/**
+ * A strcmp wrapper
+ *
+ * We don't want direct pointers to the CRT on Windows, we may
+ * get stdcall conflicts.
+ */
+int git__strcmp_cb(const void *a, const void *b)
+{
+	return strcmp((const char *)a, (const char *)b);
+}
+
+int git__strcasecmp_cb(const void *a, const void *b)
+{
+	return strcasecmp((const char *)a, (const char *)b);
+}
+
+int git__parse_bool(int *out, const char *value)
+{
+	/* A missing value means true */
+	if (value == NULL ||
+		!strcasecmp(value, "true") ||
+		!strcasecmp(value, "yes") ||
+		!strcasecmp(value, "on")) {
+		*out = 1;
+		return 0;
+	}
+	if (!strcasecmp(value, "false") ||
+		!strcasecmp(value, "no") ||
+		!strcasecmp(value, "off") ||
+		value[0] == '\0') {
+		*out = 0;
+		return 0;
+	}
+
+	return -1;
+}
+
+size_t git__unescape(char *str)
+{
+	char *scan, *pos = str;
+
+	if (!str)
+		return 0;
+
+	for (scan = str; *scan; pos++, scan++) {
+		if (*scan == '\\' && *(scan + 1) != '\0')
+			scan++; /* skip '\' but include next char */
+		if (pos != scan)
+			*pos = *scan;
+	}
+
+	if (pos != scan) {
+		*pos = '\0';
+	}
+
+	return (pos - str);
+}
+
+#if defined(HAVE_QSORT_S) || (defined(HAVE_QSORT_R) && defined(BSD))
+typedef struct {
+	git__sort_r_cmp cmp;
+	void *payload;
+} git__qsort_r_glue;
+
+static int GIT_STDLIB_CALL git__qsort_r_glue_cmp(
+	void *payload, const void *a, const void *b)
+{
+	git__qsort_r_glue *glue = payload;
+	return glue->cmp(a, b, glue->payload);
+}
+#endif
+
+void git__qsort_r(
+	void *els, size_t nel, size_t elsize, git__sort_r_cmp cmp, void *payload)
+{
+#if defined(HAVE_QSORT_R) && defined(BSD)
+	git__qsort_r_glue glue = { cmp, payload };
+	qsort_r(els, nel, elsize, &glue, git__qsort_r_glue_cmp);
+#elif defined(HAVE_QSORT_R) && defined(__GLIBC__)
+	qsort_r(els, nel, elsize, cmp, payload);
+#elif defined(HAVE_QSORT_S)
+	git__qsort_r_glue glue = { cmp, payload };
+	qsort_s(els, nel, elsize, git__qsort_r_glue_cmp, &glue);
+#else
+	git__insertsort_r(els, nel, elsize, NULL, cmp, payload);
+#endif
+}
+
+void git__insertsort_r(
+	void *els, size_t nel, size_t elsize, void *swapel,
+	git__sort_r_cmp cmp, void *payload)
+{
+	uint8_t *base = els;
+	uint8_t *end = base + nel * elsize;
+	uint8_t *i, *j;
+	bool freeswap = !swapel;
+
+	if (freeswap)
+		swapel = git__malloc(elsize);
+
+	for (i = base + elsize; i < end; i += elsize)
+		for (j = i; j > base && cmp(j, j - elsize, payload) < 0; j -= elsize) {
+			memcpy(swapel, j, elsize);
+			memcpy(j, j - elsize, elsize);
+			memcpy(j - elsize, swapel, elsize);
+		}
+
+	if (freeswap)
+		git__free(swapel);
+}
+
+/*
+ * git__utf8_iterate is taken from the utf8proc project,
+ * http://www.public-software-group.org/utf8proc
+ *
+ * Copyright (c) 2009 Public Software Group e. V., Berlin, Germany
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the ""Software""),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+static const int8_t utf8proc_utf8class[256] = {
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+	2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+	3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+	4, 4, 4, 4, 4, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0
+};
+
+int git__utf8_charlen(const uint8_t *str, int str_len)
+{
+	int length, i;
+
+	length = utf8proc_utf8class[str[0]];
+	if (!length)
+		return -1;
+
+	if (str_len >= 0 && length > str_len)
+		return -str_len;
+
+	for (i = 1; i < length; i++) {
+		if ((str[i] & 0xC0) != 0x80)
+			return -i;
+	}
+
+	return length;
+}
+
+int git__utf8_iterate(const uint8_t *str, int str_len, int32_t *dst)
+{
+	int length;
+	int32_t uc = -1;
+
+	*dst = -1;
+	length = git__utf8_charlen(str, str_len);
+	if (length < 0)
+		return -1;
+
+	switch (length) {
+		case 1:
+			uc = str[0];
+			break;
+		case 2:
+			uc = ((str[0] & 0x1F) <<  6) + (str[1] & 0x3F);
+			if (uc < 0x80) uc = -1;
+			break;
+		case 3:
+			uc = ((str[0] & 0x0F) << 12) + ((str[1] & 0x3F) <<  6)
+				+ (str[2] & 0x3F);
+			if (uc < 0x800 || (uc >= 0xD800 && uc < 0xE000) ||
+					(uc >= 0xFDD0 && uc < 0xFDF0)) uc = -1;
+			break;
+		case 4:
+			uc = ((str[0] & 0x07) << 18) + ((str[1] & 0x3F) << 12)
+				+ ((str[2] & 0x3F) <<  6) + (str[3] & 0x3F);
+			if (uc < 0x10000 || uc >= 0x110000) uc = -1;
+			break;
+	}
+
+	if (uc < 0 || ((uc & 0xFFFF) >= 0xFFFE))
+		return -1;
+
+	*dst = uc;
+	return length;
+}
+
+double git_time_monotonic(void)
+{
+	return git__timer();
+}
+
+size_t git__utf8_valid_buf_length(const uint8_t *str, size_t str_len)
+{
+	size_t offset = 0;
+
+	while (offset < str_len) {
+		int length = git__utf8_charlen(str + offset, str_len - offset);
+
+		if (length < 0)
+			break;
+
+		offset += length;
+	}
+
+	return offset;
+}
+
+#ifdef GIT_WIN32
+int git__getenv(git_buf *out, const char *name)
+{
+	wchar_t *wide_name = NULL, *wide_value = NULL;
+	DWORD value_len;
+	int error = -1;
+
+	git_buf_clear(out);
+
+	if (git__utf8_to_16_alloc(&wide_name, name) < 0)
+		return -1;
+
+	if ((value_len = GetEnvironmentVariableW(wide_name, NULL, 0)) > 0) {
+		wide_value = git__malloc(value_len * sizeof(wchar_t));
+		GITERR_CHECK_ALLOC(wide_value);
+
+		value_len = GetEnvironmentVariableW(wide_name, wide_value, value_len);
+	}
+
+	if (value_len)
+		error = git_buf_put_w(out, wide_value, value_len);
+	else if (GetLastError() == ERROR_ENVVAR_NOT_FOUND)
+		error = GIT_ENOTFOUND;
+	else
+		giterr_set(GITERR_OS, "could not read environment variable '%s'", name);
+
+	git__free(wide_name);
+	git__free(wide_value);
+	return error;
+}
+#else
+int git__getenv(git_buf *out, const char *name)
+{
+	const char *val = getenv(name);
+
+	git_buf_clear(out);
+
+	if (!val)
+		return GIT_ENOTFOUND;
+
+	return git_buf_puts(out, val);
+}
+#endif

vendor/libgit2-sys/libgit2/src/util.h

diff --git a/vendor/libgit2-sys/libgit2/src/util.h b/vendor/libgit2-sys/libgit2/src/util.h
new file mode 100644
index 0000000..67ae4ef
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/util.h
@@ -0,0 +1,556 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_util_h__
+#define INCLUDE_util_h__
+
+#include "common.h"
+
+#ifndef GIT_WIN32
+# include <ctype.h>
+#endif
+
+#include "git2/buffer.h"
+
+#include "buffer.h"
+#include "common.h"
+#include "strnlen.h"
+#include "thread-utils.h"
+
+#define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
+#define bitsizeof(x) (CHAR_BIT * sizeof(x))
+#define MSB(x, bits) ((x) & (~0ULL << (bitsizeof(x) - (bits))))
+#ifndef min
+# define min(a,b) ((a) < (b) ? (a) : (b))
+#endif
+#ifndef max
+# define max(a,b) ((a) > (b) ? (a) : (b))
+#endif
+
+#define GIT_DATE_RFC2822_SZ  32
+
+/**
+ * Return the length of a constant string.
+ * We are aware that `strlen` performs the same task and is usually
+ * optimized away by the compiler, whilst being safer because it returns
+ * valid values when passed a pointer instead of a constant string; however
+ * this macro will transparently work with wide-char and single-char strings.
+ */
+#define CONST_STRLEN(x) ((sizeof(x)/sizeof(x[0])) - 1)
+
+#if defined(GIT_MSVC_CRTDBG)
+
+/* Enable MSVC CRTDBG memory leak reporting.
+ *
+ * We DO NOT use the "_CRTDBG_MAP_ALLOC" macro described in the MSVC
+ * documentation because all allocs/frees in libgit2 already go through
+ * the "git__" routines defined in this file.  Simply using the normal
+ * reporting mechanism causes all leaks to be attributed to a routine
+ * here in util.h (ie, the actual call to calloc()) rather than the
+ * caller of git__calloc().
+ *
+ * Therefore, we declare a set of "git__crtdbg__" routines to replace
+ * the corresponding "git__" routines and re-define the "git__" symbols
+ * as macros.  This allows us to get and report the file:line info of
+ * the real caller.
+ *
+ * We DO NOT replace the "git__free" routine because it needs to remain
+ * a function pointer because it is used as a function argument when
+ * setting up various structure "destructors".
+ *
+ * We also DO NOT use the "_CRTDBG_MAP_ALLOC" macro because it causes
+ * "free" to be remapped to "_free_dbg" and this causes problems for
+ * structures which define a field named "free".
+ *
+ * Finally, CRTDBG must be explicitly enabled and configured at program
+ * startup.  See tests/main.c for an example.
+ */
+
+#include "win32/w32_crtdbg_stacktrace.h"
+
+#define git__malloc(len)                      git__crtdbg__malloc(len, __FILE__, __LINE__)
+#define git__calloc(nelem, elsize)            git__crtdbg__calloc(nelem, elsize, __FILE__, __LINE__)
+#define git__strdup(str)                      git__crtdbg__strdup(str, __FILE__, __LINE__)
+#define git__strndup(str, n)                  git__crtdbg__strndup(str, n, __FILE__, __LINE__)
+#define git__substrdup(str, n)                git__crtdbg__substrdup(str, n, __FILE__, __LINE__)
+#define git__realloc(ptr, size)               git__crtdbg__realloc(ptr, size, __FILE__, __LINE__)
+#define git__reallocarray(ptr, nelem, elsize) git__crtdbg__reallocarray(ptr, nelem, elsize, __FILE__, __LINE__)
+#define git__mallocarray(nelem, elsize)       git__crtdbg__mallocarray(nelem, elsize, __FILE__, __LINE__)
+
+#else
+
+/*
+ * Custom memory allocation wrappers
+ * that set error code and error message
+ * on allocation failure
+ */
+GIT_INLINE(void *) git__malloc(size_t len)
+{
+	void *ptr = malloc(len);
+	if (!ptr) giterr_set_oom();
+	return ptr;
+}
+
+GIT_INLINE(void *) git__calloc(size_t nelem, size_t elsize)
+{
+	void *ptr = calloc(nelem, elsize);
+	if (!ptr) giterr_set_oom();
+	return ptr;
+}
+
+GIT_INLINE(char *) git__strdup(const char *str)
+{
+	char *ptr = strdup(str);
+	if (!ptr) giterr_set_oom();
+	return ptr;
+}
+
+GIT_INLINE(char *) git__strndup(const char *str, size_t n)
+{
+	size_t length = 0, alloclength;
+	char *ptr;
+
+	length = p_strnlen(str, n);
+
+	if (GIT_ADD_SIZET_OVERFLOW(&alloclength, length, 1) ||
+		!(ptr = git__malloc(alloclength)))
+		return NULL;
+
+	if (length)
+		memcpy(ptr, str, length);
+
+	ptr[length] = '\0';
+
+	return ptr;
+}
+
+/* NOTE: This doesn't do null or '\0' checking.  Watch those boundaries! */
+GIT_INLINE(char *) git__substrdup(const char *start, size_t n)
+{
+	char *ptr;
+	size_t alloclen;
+
+	if (GIT_ADD_SIZET_OVERFLOW(&alloclen, n, 1) ||
+		!(ptr = git__malloc(alloclen)))
+		return NULL;
+
+	memcpy(ptr, start, n);
+	ptr[n] = '\0';
+	return ptr;
+}
+
+GIT_INLINE(void *) git__realloc(void *ptr, size_t size)
+{
+	void *new_ptr = realloc(ptr, size);
+	if (!new_ptr) giterr_set_oom();
+	return new_ptr;
+}
+
+/**
+ * Similar to `git__realloc`, except that it is suitable for reallocing an
+ * array to a new number of elements of `nelem`, each of size `elsize`.
+ * The total size calculation is checked for overflow.
+ */
+GIT_INLINE(void *) git__reallocarray(void *ptr, size_t nelem, size_t elsize)
+{
+	size_t newsize;
+	return GIT_MULTIPLY_SIZET_OVERFLOW(&newsize, nelem, elsize) ?
+		NULL : realloc(ptr, newsize);
+}
+
+/**
+ * Similar to `git__calloc`, except that it does not zero memory.
+ */
+GIT_INLINE(void *) git__mallocarray(size_t nelem, size_t elsize)
+{
+	return git__reallocarray(NULL, nelem, elsize);
+}
+
+#endif /* !MSVC_CTRDBG */
+
+GIT_INLINE(void) git__free(void *ptr)
+{
+	free(ptr);
+}
+
+#define STRCMP_CASESELECT(IGNORE_CASE, STR1, STR2) \
+	((IGNORE_CASE) ? strcasecmp((STR1), (STR2)) : strcmp((STR1), (STR2)))
+
+#define CASESELECT(IGNORE_CASE, ICASE, CASE) \
+	((IGNORE_CASE) ? (ICASE) : (CASE))
+
+extern int git__prefixcmp(const char *str, const char *prefix);
+extern int git__prefixcmp_icase(const char *str, const char *prefix);
+extern int git__prefixncmp(const char *str, size_t str_n, const char *prefix);
+extern int git__prefixncmp_icase(const char *str, size_t str_n, const char *prefix);
+extern int git__suffixcmp(const char *str, const char *suffix);
+
+GIT_INLINE(int) git__signum(int val)
+{
+	return ((val > 0) - (val < 0));
+}
+
+extern int git__strtol32(int32_t *n, const char *buff, const char **end_buf, int base);
+extern int git__strntol32(int32_t *n, const char *buff, size_t buff_len, const char **end_buf, int base);
+extern int git__strtol64(int64_t *n, const char *buff, const char **end_buf, int base);
+extern int git__strntol64(int64_t *n, const char *buff, size_t buff_len, const char **end_buf, int base);
+
+
+extern void git__hexdump(const char *buffer, size_t n);
+extern uint32_t git__hash(const void *key, int len, uint32_t seed);
+
+/* 32-bit cross-platform rotl */
+#ifdef _MSC_VER /* use built-in method in MSVC */
+#	define git__rotl(v, s) (uint32_t)_rotl(v, s)
+#else /* use bitops in GCC; with o2 this gets optimized to a rotl instruction */
+#	define git__rotl(v, s) (uint32_t)(((uint32_t)(v) << (s)) | ((uint32_t)(v) >> (32 - (s))))
+#endif
+
+extern char *git__strtok(char **end, const char *sep);
+extern char *git__strsep(char **end, const char *sep);
+
+extern void git__strntolower(char *str, size_t len);
+extern void git__strtolower(char *str);
+
+#ifdef GIT_WIN32
+GIT_INLINE(int) git__tolower(int c)
+{
+	return (c >= 'A' && c <= 'Z') ? (c + 32) : c;
+}
+#else
+# define git__tolower(a) tolower(a)
+#endif
+
+extern size_t git__linenlen(const char *buffer, size_t buffer_len);
+
+GIT_INLINE(const char *) git__next_line(const char *s)
+{
+	while (*s && *s != '\n') s++;
+	while (*s == '\n' || *s == '\r') s++;
+	return s;
+}
+
+GIT_INLINE(const void *) git__memrchr(const void *s, int c, size_t n)
+{
+	const unsigned char *cp;
+
+	if (n != 0) {
+		cp = (unsigned char *)s + n;
+		do {
+			if (*(--cp) == (unsigned char)c)
+				return cp;
+		} while (--n != 0);
+	}
+
+	return NULL;
+}
+
+typedef int (*git__tsort_cmp)(const void *a, const void *b);
+
+extern void git__tsort(void **dst, size_t size, git__tsort_cmp cmp);
+
+typedef int (*git__sort_r_cmp)(const void *a, const void *b, void *payload);
+
+extern void git__tsort_r(
+	void **dst, size_t size, git__sort_r_cmp cmp, void *payload);
+
+extern void git__qsort_r(
+	void *els, size_t nel, size_t elsize, git__sort_r_cmp cmp, void *payload);
+
+extern void git__insertsort_r(
+	void *els, size_t nel, size_t elsize, void *swapel,
+	git__sort_r_cmp cmp, void *payload);
+
+/**
+ * @param position If non-NULL, this will be set to the position where the
+ * 		element is or would be inserted if not found.
+ * @return 0 if found; GIT_ENOTFOUND if not found
+ */
+extern int git__bsearch(
+	void **array,
+	size_t array_len,
+	const void *key,
+	int (*compare)(const void *key, const void *element),
+	size_t *position);
+
+extern int git__bsearch_r(
+	void **array,
+	size_t array_len,
+	const void *key,
+	int (*compare_r)(const void *key, const void *element, void *payload),
+	void *payload,
+	size_t *position);
+
+extern int git__strcmp_cb(const void *a, const void *b);
+extern int git__strcasecmp_cb(const void *a, const void *b);
+
+extern int git__strcmp(const char *a, const char *b);
+extern int git__strcasecmp(const char *a, const char *b);
+extern int git__strncmp(const char *a, const char *b, size_t sz);
+extern int git__strncasecmp(const char *a, const char *b, size_t sz);
+
+extern int git__strcasesort_cmp(const char *a, const char *b);
+
+typedef struct {
+	git_atomic refcount;
+	void *owner;
+} git_refcount;
+
+typedef void (*git_refcount_freeptr)(void *r);
+
+#define GIT_REFCOUNT_INC(r) { \
+	git_atomic_inc(&(r)->rc.refcount);	\
+}
+
+#define GIT_REFCOUNT_DEC(_r, do_free) { \
+	git_refcount *r = &(_r)->rc; \
+	int val = git_atomic_dec(&r->refcount); \
+	if (val <= 0 && r->owner == NULL) { do_free(_r); } \
+}
+
+#define GIT_REFCOUNT_OWN(r, o) { \
+	(r)->rc.owner = o; \
+}
+
+#define GIT_REFCOUNT_OWNER(r) ((r)->rc.owner)
+
+#define GIT_REFCOUNT_VAL(r) git_atomic_get((r)->rc.refcount)
+
+
+static signed char from_hex[] = {
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 00 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 10 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 20 */
+ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, /* 30 */
+-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 40 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 50 */
+-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 60 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 70 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 80 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 90 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* a0 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* b0 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* c0 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* d0 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* e0 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* f0 */
+};
+
+GIT_INLINE(int) git__fromhex(char h)
+{
+	return from_hex[(unsigned char) h];
+}
+
+GIT_INLINE(int) git__ishex(const char *str)
+{
+	unsigned i;
+	for (i=0; str[i] != '\0'; i++)
+		if (git__fromhex(str[i]) < 0)
+			return 0;
+	return 1;
+}
+
+GIT_INLINE(size_t) git__size_t_bitmask(size_t v)
+{
+	v--;
+	v |= v >> 1;
+	v |= v >> 2;
+	v |= v >> 4;
+	v |= v >> 8;
+	v |= v >> 16;
+
+	return v;
+}
+
+GIT_INLINE(size_t) git__size_t_powerof2(size_t v)
+{
+	return git__size_t_bitmask(v) + 1;
+}
+
+GIT_INLINE(bool) git__isupper(int c)
+{
+	return (c >= 'A' && c <= 'Z');
+}
+
+GIT_INLINE(bool) git__isalpha(int c)
+{
+	return ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'));
+}
+
+GIT_INLINE(bool) git__isdigit(int c)
+{
+	return (c >= '0' && c <= '9');
+}
+
+GIT_INLINE(bool) git__isspace(int c)
+{
+	return (c == ' ' || c == '\t' || c == '\n' || c == '\f' || c == '\r' || c == '\v');
+}
+
+GIT_INLINE(bool) git__isspace_nonlf(int c)
+{
+	return (c == ' ' || c == '\t' || c == '\f' || c == '\r' || c == '\v');
+}
+
+GIT_INLINE(bool) git__iswildcard(int c)
+{
+	return (c == '*' || c == '?' || c == '[');
+}
+
+GIT_INLINE(bool) git__isxdigit(int c)
+{
+	return ((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F'));
+}
+
+/*
+ * Parse a string value as a boolean, just like Core Git does.
+ *
+ * Valid values for true are: 'true', 'yes', 'on'
+ * Valid values for false are: 'false', 'no', 'off'
+ */
+extern int git__parse_bool(int *out, const char *value);
+
+/*
+ * Parse a string into a value as a git_time_t.
+ *
+ * Sample valid input:
+ * - "yesterday"
+ * - "July 17, 2003"
+ * - "2003-7-17 08:23"
+ */
+extern int git__date_parse(git_time_t *out, const char *date);
+
+/*
+ * Format a git_time as a RFC2822 string
+ *
+ * @param out buffer to store formatted date; a '\\0' terminator will automatically be added.
+ * @param len size of the buffer; should be atleast `GIT_DATE_RFC2822_SZ` in size;
+ * @param date the date to be formatted
+ * @return 0 if successful; -1 on error
+ */
+extern int git__date_rfc2822_fmt(char *out, size_t len, const git_time *date);
+
+/*
+ * Unescapes a string in-place.
+ *
+ * Edge cases behavior:
+ * - "jackie\" -> "jacky\"
+ * - "chan\\" -> "chan\"
+ */
+extern size_t git__unescape(char *str);
+
+/*
+ * Iterate through an UTF-8 string, yielding one
+ * codepoint at a time.
+ *
+ * @param str current position in the string
+ * @param str_len size left in the string; -1 if the string is NULL-terminated
+ * @param dst pointer where to store the current codepoint
+ * @return length in bytes of the read codepoint; -1 if the codepoint was invalid
+ */
+extern int git__utf8_iterate(const uint8_t *str, int str_len, int32_t *dst);
+
+/*
+ * Iterate through an UTF-8 string and stops after finding any invalid UTF-8
+ * codepoints.
+ *
+ * @param str string to scan
+ * @param str_len size of the string
+ * @return length in bytes of the string that contains valid data
+ */
+extern size_t git__utf8_valid_buf_length(const uint8_t *str, size_t str_len);
+
+/*
+ * Safely zero-out memory, making sure that the compiler
+ * doesn't optimize away the operation.
+ */
+GIT_INLINE(void) git__memzero(void *data, size_t size)
+{
+#ifdef _MSC_VER
+	SecureZeroMemory((PVOID)data, size);
+#else
+	volatile uint8_t *scan = (volatile uint8_t *)data;
+
+	while (size--)
+		*scan++ = 0x0;
+#endif
+}
+
+#ifdef GIT_WIN32
+
+GIT_INLINE(double) git__timer(void)
+{
+	/* We need the initial tick count to detect if the tick
+	 * count has rolled over. */
+	static DWORD initial_tick_count = 0;
+
+	/* GetTickCount returns the number of milliseconds that have
+	 * elapsed since the system was started. */
+	DWORD count = GetTickCount();
+
+	if(initial_tick_count == 0) {
+		initial_tick_count = count;
+	} else if (count < initial_tick_count) {
+		/* The tick count has rolled over - adjust for it. */
+		count = (0xFFFFFFFF - initial_tick_count) + count;
+	}
+
+	return (double) count / (double) 1000;
+}
+
+#elif __APPLE__
+
+#include <mach/mach_time.h>
+
+GIT_INLINE(double) git__timer(void)
+{
+   uint64_t time = mach_absolute_time();
+   static double scaling_factor = 0;
+
+   if (scaling_factor == 0) {
+       mach_timebase_info_data_t info;
+       (void)mach_timebase_info(&info);
+       scaling_factor = (double)info.numer / (double)info.denom;
+   }
+
+   return (double)time * scaling_factor / 1.0E9;
+}
+
+#elif defined(AMIGA)
+
+#include <proto/timer.h>
+
+GIT_INLINE(double) git__timer(void)
+{
+	struct TimeVal tv;
+	ITimer->GetUpTime(&tv);
+	return (double)tv.Seconds + (double)tv.Microseconds / 1.0E6;
+}
+
+#else
+
+#include <sys/time.h>
+
+GIT_INLINE(double) git__timer(void)
+{
+	struct timespec tp;
+
+	if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0) {
+		return (double) tp.tv_sec + (double) tp.tv_nsec / 1.0E9;
+	} else {
+		/* Fall back to using gettimeofday */
+		struct timeval tv;
+		struct timezone tz;
+		gettimeofday(&tv, &tz);
+		return (double)tv.tv_sec + (double)tv.tv_usec / 1.0E6;
+	}
+}
+
+#endif
+
+extern int git__getenv(git_buf *out, const char *name);
+
+#endif

vendor/libgit2-sys/libgit2/src/varint.c

diff --git a/vendor/libgit2-sys/libgit2/src/varint.c b/vendor/libgit2-sys/libgit2/src/varint.c
new file mode 100644
index 0000000..9ffc1d7
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/varint.c
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "varint.h"
+
+uintmax_t git_decode_varint(const unsigned char *bufp, size_t *varint_len)
+{
+	const unsigned char *buf = bufp;
+	unsigned char c = *buf++;
+	uintmax_t val = c & 127;
+	while (c & 128) {
+		val += 1;
+		if (!val || MSB(val, 7)) {
+			/* This is not a valid varint_len, so it signals
+			   the error */
+			*varint_len = 0;
+			return 0; /* overflow */
+		}
+		c = *buf++;
+		val = (val << 7) + (c & 127);
+	}
+	*varint_len = buf - bufp;
+	return val;
+}
+
+int git_encode_varint(unsigned char *buf, size_t bufsize, uintmax_t value)
+{
+	unsigned char varint[16];
+	unsigned pos = sizeof(varint) - 1;
+	varint[pos] = value & 127;
+	while (value >>= 7)
+		varint[--pos] = 128 | (--value & 127);
+	if (buf) {
+		if (bufsize < (sizeof(varint) - pos))
+			return -1;
+		memcpy(buf, varint + pos, sizeof(varint) - pos);
+	}
+	return sizeof(varint) - pos;
+}

vendor/libgit2-sys/libgit2/src/varint.h

diff --git a/vendor/libgit2-sys/libgit2/src/varint.h b/vendor/libgit2-sys/libgit2/src/varint.h
new file mode 100644
index 0000000..652e224
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/varint.h
@@ -0,0 +1,17 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_varint_h__
+#define INCLUDE_varint_h__
+
+#include "common.h"
+
+#include <stdint.h>
+
+extern int git_encode_varint(unsigned char *, size_t, uintmax_t);
+extern uintmax_t git_decode_varint(const unsigned char *, size_t *);
+
+#endif

vendor/libgit2-sys/libgit2/src/vector.c

diff --git a/vendor/libgit2-sys/libgit2/src/vector.c b/vendor/libgit2-sys/libgit2/src/vector.c
new file mode 100644
index 0000000..b12fa94
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/vector.c
@@ -0,0 +1,422 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "vector.h"
+
+#include "integer.h"
+
+/* In elements, not bytes */
+#define MIN_ALLOCSIZE	8
+
+GIT_INLINE(size_t) compute_new_size(git_vector *v)
+{
+	size_t new_size = v->_alloc_size;
+
+	/* Use a resize factor of 1.5, which is quick to compute using integer
+	 * instructions and less than the golden ratio (1.618...) */
+	if (new_size < MIN_ALLOCSIZE)
+		new_size = MIN_ALLOCSIZE;
+	else if (new_size <= (SIZE_MAX / 3) * 2)
+		new_size += new_size / 2;
+	else
+		new_size = SIZE_MAX;
+
+	return new_size;
+}
+
+GIT_INLINE(int) resize_vector(git_vector *v, size_t new_size)
+{
+	void *new_contents;
+
+	new_contents = git__reallocarray(v->contents, new_size, sizeof(void *));
+	GITERR_CHECK_ALLOC(new_contents);
+
+	v->_alloc_size = new_size;
+	v->contents = new_contents;
+
+	return 0;
+}
+
+int git_vector_size_hint(git_vector *v, size_t size_hint)
+{
+	if (v->_alloc_size >= size_hint)
+		return 0;
+	return resize_vector(v, size_hint);
+}
+
+int git_vector_dup(git_vector *v, const git_vector *src, git_vector_cmp cmp)
+{
+	size_t bytes;
+
+	assert(v && src);
+
+	GITERR_CHECK_ALLOC_MULTIPLY(&bytes, src->length, sizeof(void *));
+
+	v->_alloc_size = src->length;
+	v->_cmp = cmp ? cmp : src->_cmp;
+	v->length = src->length;
+	v->flags  = src->flags;
+	if (cmp != src->_cmp)
+		git_vector_set_sorted(v, 0);
+	v->contents = git__malloc(bytes);
+	GITERR_CHECK_ALLOC(v->contents);
+
+	memcpy(v->contents, src->contents, bytes);
+
+	return 0;
+}
+
+void git_vector_free(git_vector *v)
+{
+	assert(v);
+
+	git__free(v->contents);
+	v->contents = NULL;
+
+	v->length = 0;
+	v->_alloc_size = 0;
+}
+
+void git_vector_free_deep(git_vector *v)
+{
+	size_t i;
+
+	assert(v);
+
+	for (i = 0; i < v->length; ++i) {
+		git__free(v->contents[i]);
+		v->contents[i] = NULL;
+	}
+
+	git_vector_free(v);
+}
+
+int git_vector_init(git_vector *v, size_t initial_size, git_vector_cmp cmp)
+{
+	assert(v);
+
+	v->_alloc_size = 0;
+	v->_cmp = cmp;
+	v->length = 0;
+	v->flags = GIT_VECTOR_SORTED;
+	v->contents = NULL;
+
+	return resize_vector(v, max(initial_size, MIN_ALLOCSIZE));
+}
+
+void **git_vector_detach(size_t *size, size_t *asize, git_vector *v)
+{
+	void **data = v->contents;
+
+	if (size)
+		*size = v->length;
+	if (asize)
+		*asize = v->_alloc_size;
+
+	v->_alloc_size = 0;
+	v->length   = 0;
+	v->contents = NULL;
+
+	return data;
+}
+
+int git_vector_insert(git_vector *v, void *element)
+{
+	assert(v);
+
+	if (v->length >= v->_alloc_size &&
+		resize_vector(v, compute_new_size(v)) < 0)
+		return -1;
+
+	v->contents[v->length++] = element;
+
+	git_vector_set_sorted(v, v->length <= 1);
+
+	return 0;
+}
+
+int git_vector_insert_sorted(
+	git_vector *v, void *element, int (*on_dup)(void **old, void *new))
+{
+	int result;
+	size_t pos;
+
+	assert(v && v->_cmp);
+
+	if (!git_vector_is_sorted(v))
+		git_vector_sort(v);
+
+	if (v->length >= v->_alloc_size &&
+		resize_vector(v, compute_new_size(v)) < 0)
+		return -1;
+
+	/* If we find the element and have a duplicate handler callback,
+	 * invoke it.  If it returns non-zero, then cancel insert, otherwise
+	 * proceed with normal insert.
+	 */
+	if (!git__bsearch(v->contents, v->length, element, v->_cmp, &pos) &&
+		on_dup && (result = on_dup(&v->contents[pos], element)) < 0)
+		return result;
+
+	/* shift elements to the right */
+	if (pos < v->length)
+		memmove(v->contents + pos + 1, v->contents + pos,
+		        (v->length - pos) * sizeof(void *));
+
+	v->contents[pos] = element;
+	v->length++;
+
+	return 0;
+}
+
+void git_vector_sort(git_vector *v)
+{
+	assert(v);
+
+	if (git_vector_is_sorted(v) || !v->_cmp)
+		return;
+
+	if (v->length > 1)
+		git__tsort(v->contents, v->length, v->_cmp);
+	git_vector_set_sorted(v, 1);
+}
+
+int git_vector_bsearch2(
+	size_t *at_pos,
+	git_vector *v,
+	git_vector_cmp key_lookup,
+	const void *key)
+{
+	assert(v && key && key_lookup);
+
+	/* need comparison function to sort the vector */
+	if (!v->_cmp)
+		return -1;
+
+	git_vector_sort(v);
+
+	return git__bsearch(v->contents, v->length, key, key_lookup, at_pos);
+}
+
+int git_vector_search2(
+	size_t *at_pos, const git_vector *v, git_vector_cmp key_lookup, const void *key)
+{
+	size_t i;
+
+	assert(v && key && key_lookup);
+
+	for (i = 0; i < v->length; ++i) {
+		if (key_lookup(key, v->contents[i]) == 0) {
+			if (at_pos)
+				*at_pos = i;
+
+			return 0;
+		}
+	}
+
+	return GIT_ENOTFOUND;
+}
+
+static int strict_comparison(const void *a, const void *b)
+{
+	return (a == b) ? 0 : -1;
+}
+
+int git_vector_search(size_t *at_pos, const git_vector *v, const void *entry)
+{
+	return git_vector_search2(at_pos, v, v->_cmp ? v->_cmp : strict_comparison, entry);
+}
+
+int git_vector_remove(git_vector *v, size_t idx)
+{
+	size_t shift_count;
+
+	assert(v);
+
+	if (idx >= v->length)
+		return GIT_ENOTFOUND;
+
+	shift_count = v->length - idx - 1;
+
+	if (shift_count)
+		memmove(&v->contents[idx], &v->contents[idx + 1],
+			shift_count * sizeof(void *));
+
+	v->length--;
+	return 0;
+}
+
+void git_vector_pop(git_vector *v)
+{
+	if (v->length > 0)
+		v->length--;
+}
+
+void git_vector_uniq(git_vector *v, void  (*git_free_cb)(void *))
+{
+	git_vector_cmp cmp;
+	size_t i, j;
+
+	if (v->length <= 1)
+		return;
+
+	git_vector_sort(v);
+	cmp = v->_cmp ? v->_cmp : strict_comparison;
+
+	for (i = 0, j = 1 ; j < v->length; ++j)
+		if (!cmp(v->contents[i], v->contents[j])) {
+			if (git_free_cb)
+				git_free_cb(v->contents[i]);
+
+			v->contents[i] = v->contents[j];
+		} else
+			v->contents[++i] = v->contents[j];
+
+	v->length -= j - i - 1;
+}
+
+void git_vector_remove_matching(
+	git_vector *v,
+	int (*match)(const git_vector *v, size_t idx, void *payload),
+	void *payload)
+{
+	size_t i, j;
+
+	for (i = 0, j = 0; j < v->length; ++j) {
+		v->contents[i] = v->contents[j];
+
+		if (!match(v, i, payload))
+			i++;
+	}
+
+	v->length = i;
+}
+
+void git_vector_clear(git_vector *v)
+{
+	assert(v);
+	v->length = 0;
+	git_vector_set_sorted(v, 1);
+}
+
+void git_vector_swap(git_vector *a, git_vector *b)
+{
+	git_vector t;
+
+	assert(a && b);
+
+	if (a != b) {
+		memcpy(&t, a, sizeof(t));
+		memcpy(a, b, sizeof(t));
+		memcpy(b, &t, sizeof(t));
+	}
+}
+
+int git_vector_resize_to(git_vector *v, size_t new_length)
+{
+	if (new_length > v->_alloc_size &&
+		resize_vector(v, new_length) < 0)
+		return -1;
+
+	if (new_length > v->length)
+		memset(&v->contents[v->length], 0,
+			sizeof(void *) * (new_length - v->length));
+
+	v->length = new_length;
+
+	return 0;
+}
+
+int git_vector_insert_null(git_vector *v, size_t idx, size_t insert_len)
+{
+	size_t new_length;
+
+	assert(insert_len > 0 && idx <= v->length);
+
+	GITERR_CHECK_ALLOC_ADD(&new_length, v->length, insert_len);
+
+	if (new_length > v->_alloc_size && resize_vector(v, new_length) < 0)
+		return -1;
+
+	memmove(&v->contents[idx + insert_len], &v->contents[idx],
+		sizeof(void *) * (v->length - idx));
+	memset(&v->contents[idx], 0, sizeof(void *) * insert_len);
+
+	v->length = new_length;
+	return 0;
+}
+
+int git_vector_remove_range(git_vector *v, size_t idx, size_t remove_len)
+{
+	size_t new_length = v->length - remove_len;
+	size_t end_idx = 0;
+	
+	assert(remove_len > 0);
+
+	if (git__add_sizet_overflow(&end_idx, idx, remove_len))
+		assert(0);
+
+	assert(end_idx <= v->length);
+
+	if (end_idx < v->length)
+		memmove(&v->contents[idx], &v->contents[end_idx],
+			sizeof(void *) * (v->length - end_idx));
+
+	memset(&v->contents[new_length], 0, sizeof(void *) * remove_len);
+
+	v->length = new_length;
+	return 0;
+}
+
+int git_vector_set(void **old, git_vector *v, size_t position, void *value)
+{
+	if (position + 1 > v->length) {
+		if (git_vector_resize_to(v, position + 1) < 0)
+			return -1;
+	}
+
+	if (old != NULL)
+		*old = v->contents[position];
+
+	v->contents[position] = value;
+
+	return 0;
+}
+
+int git_vector_verify_sorted(const git_vector *v)
+{
+	size_t i;
+
+	if (!git_vector_is_sorted(v))
+		return -1;
+
+	for (i = 1; i < v->length; ++i) {
+		if (v->_cmp(v->contents[i - 1], v->contents[i]) > 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+void git_vector_reverse(git_vector *v)
+{
+	size_t a, b;
+
+	if (v->length == 0)
+		return;
+
+	a = 0;
+	b = v->length - 1;
+
+	while (a < b) {
+		void *tmp = v->contents[a];
+		v->contents[a] = v->contents[b];
+		v->contents[b] = tmp;
+		a++;
+		b--;
+	}
+}

vendor/libgit2-sys/libgit2/src/vector.h

diff --git a/vendor/libgit2-sys/libgit2/src/vector.h b/vendor/libgit2-sys/libgit2/src/vector.h
new file mode 100644
index 0000000..cc4c314
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/vector.h
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_vector_h__
+#define INCLUDE_vector_h__
+
+#include "common.h"
+
+typedef int (*git_vector_cmp)(const void *, const void *);
+
+enum {
+	GIT_VECTOR_SORTED = (1u << 0),
+	GIT_VECTOR_FLAG_MAX = (1u << 1),
+};
+
+typedef struct git_vector {
+	size_t _alloc_size;
+	git_vector_cmp _cmp;
+	void **contents;
+	size_t length;
+	uint32_t flags;
+} git_vector;
+
+#define GIT_VECTOR_INIT {0}
+
+int git_vector_init(git_vector *v, size_t initial_size, git_vector_cmp cmp);
+void git_vector_free(git_vector *v);
+void git_vector_free_deep(git_vector *v); /* free each entry and self */
+void git_vector_clear(git_vector *v);
+int git_vector_dup(git_vector *v, const git_vector *src, git_vector_cmp cmp);
+void git_vector_swap(git_vector *a, git_vector *b);
+int git_vector_size_hint(git_vector *v, size_t size_hint);
+
+void **git_vector_detach(size_t *size, size_t *asize, git_vector *v);
+
+void git_vector_sort(git_vector *v);
+
+/** Linear search for matching entry using internal comparison function */
+int git_vector_search(size_t *at_pos, const git_vector *v, const void *entry);
+
+/** Linear search for matching entry using explicit comparison function */
+int git_vector_search2(size_t *at_pos, const git_vector *v, git_vector_cmp cmp, const void *key);
+
+/**
+ * Binary search for matching entry using explicit comparison function that
+ * returns position where item would go if not found.
+ */
+int git_vector_bsearch2(
+	size_t *at_pos, git_vector *v, git_vector_cmp cmp, const void *key);
+
+/** Binary search for matching entry using internal comparison function */
+GIT_INLINE(int) git_vector_bsearch(size_t *at_pos, git_vector *v, const void *key)
+{
+	return git_vector_bsearch2(at_pos, v, v->_cmp, key);
+}
+
+GIT_INLINE(void *) git_vector_get(const git_vector *v, size_t position)
+{
+	return (position < v->length) ? v->contents[position] : NULL;
+}
+
+#define GIT_VECTOR_GET(V,I) ((I) < (V)->length ? (V)->contents[(I)] : NULL)
+
+GIT_INLINE(size_t) git_vector_length(const git_vector *v)
+{
+	return v->length;
+}
+
+GIT_INLINE(void *) git_vector_last(const git_vector *v)
+{
+	return (v->length > 0) ? git_vector_get(v, v->length - 1) : NULL;
+}
+
+#define git_vector_foreach(v, iter, elem)	\
+	for ((iter) = 0; (iter) < (v)->length && ((elem) = (v)->contents[(iter)], 1); (iter)++ )
+
+#define git_vector_rforeach(v, iter, elem)	\
+	for ((iter) = (v)->length - 1; (iter) < SIZE_MAX && ((elem) = (v)->contents[(iter)], 1); (iter)-- )
+
+int git_vector_insert(git_vector *v, void *element);
+int git_vector_insert_sorted(git_vector *v, void *element,
+	int (*on_dup)(void **old, void *new));
+int git_vector_remove(git_vector *v, size_t idx);
+void git_vector_pop(git_vector *v);
+void git_vector_uniq(git_vector *v, void  (*git_free_cb)(void *));
+
+void git_vector_remove_matching(
+	git_vector *v,
+	int (*match)(const git_vector *v, size_t idx, void *payload),
+	void *payload);
+
+int git_vector_resize_to(git_vector *v, size_t new_length);
+int git_vector_insert_null(git_vector *v, size_t idx, size_t insert_len);
+int git_vector_remove_range(git_vector *v, size_t idx, size_t remove_len);
+
+int git_vector_set(void **old, git_vector *v, size_t position, void *value);
+
+/** Check if vector is sorted */
+#define git_vector_is_sorted(V) (((V)->flags & GIT_VECTOR_SORTED) != 0)
+
+/** Directly set sorted state of vector */
+#define git_vector_set_sorted(V,S) do { \
+	(V)->flags = (S) ? ((V)->flags | GIT_VECTOR_SORTED) : \
+		((V)->flags & ~GIT_VECTOR_SORTED); } while (0)
+
+/** Set the comparison function used for sorting the vector */
+GIT_INLINE(void) git_vector_set_cmp(git_vector *v, git_vector_cmp cmp)
+{
+	if (cmp != v->_cmp) {
+		v->_cmp = cmp;
+		git_vector_set_sorted(v, 0);
+	}
+}
+
+/* Just use this in tests, not for realz. returns -1 if not sorted */
+int git_vector_verify_sorted(const git_vector *v);
+
+/**
+ * Reverse the vector in-place.
+ */
+void git_vector_reverse(git_vector *v);
+
+#endif

vendor/libgit2-sys/libgit2/src/win32/dir.c

diff --git a/vendor/libgit2-sys/libgit2/src/win32/dir.c b/vendor/libgit2-sys/libgit2/src/win32/dir.c
new file mode 100644
index 0000000..1d37874
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/dir.c
@@ -0,0 +1,122 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "dir.h"
+
+#define GIT__WIN32_NO_WRAP_DIR
+#include "posix.h"
+
+git__DIR *git__opendir(const char *dir)
+{
+	git_win32_path filter_w;
+	git__DIR *new = NULL;
+	size_t dirlen, alloclen;
+
+	if (!dir || !git_win32__findfirstfile_filter(filter_w, dir))
+		return NULL;
+
+	dirlen = strlen(dir);
+
+	if (GIT_ADD_SIZET_OVERFLOW(&alloclen, sizeof(*new), dirlen) ||
+		GIT_ADD_SIZET_OVERFLOW(&alloclen, alloclen, 1) ||
+		!(new = git__calloc(1, alloclen)))
+		return NULL;
+
+	memcpy(new->dir, dir, dirlen);
+
+	new->h = FindFirstFileW(filter_w, &new->f);
+
+	if (new->h == INVALID_HANDLE_VALUE) {
+		giterr_set(GITERR_OS, "could not open directory '%s'", dir);
+		git__free(new);
+		return NULL;
+	}
+
+	new->first = 1;
+	return new;
+}
+
+int git__readdir_ext(
+	git__DIR *d,
+	struct git__dirent *entry,
+	struct git__dirent **result,
+	int *is_dir)
+{
+	if (!d || !entry || !result || d->h == INVALID_HANDLE_VALUE)
+		return -1;
+
+	*result = NULL;
+
+	if (d->first)
+		d->first = 0;
+	else if (!FindNextFileW(d->h, &d->f)) {
+		if (GetLastError() == ERROR_NO_MORE_FILES)
+			return 0;
+		giterr_set(GITERR_OS, "could not read from directory '%s'", d->dir);
+		return -1;
+	}
+
+	/* Convert the path to UTF-8 */
+	if (git_win32_path_to_utf8(entry->d_name, d->f.cFileName) < 0)
+		return -1;
+
+	entry->d_ino = 0;
+
+	*result = entry;
+
+	if (is_dir != NULL)
+		*is_dir = ((d->f.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0);
+
+	return 0;
+}
+
+struct git__dirent *git__readdir(git__DIR *d)
+{
+	struct git__dirent *result;
+	if (git__readdir_ext(d, &d->entry, &result, NULL) < 0)
+		return NULL;
+	return result;
+}
+
+void git__rewinddir(git__DIR *d)
+{
+	git_win32_path filter_w;
+
+	if (!d)
+		return;
+
+	if (d->h != INVALID_HANDLE_VALUE) {
+		FindClose(d->h);
+		d->h = INVALID_HANDLE_VALUE;
+		d->first = 0;
+	}
+
+	if (!git_win32__findfirstfile_filter(filter_w, d->dir))
+		return;
+
+	d->h = FindFirstFileW(filter_w, &d->f);
+
+	if (d->h == INVALID_HANDLE_VALUE)
+		giterr_set(GITERR_OS, "could not open directory '%s'", d->dir);
+	else
+		d->first = 1;
+}
+
+int git__closedir(git__DIR *d)
+{
+	if (!d)
+		return 0;
+
+	if (d->h != INVALID_HANDLE_VALUE) {
+		FindClose(d->h);
+		d->h = INVALID_HANDLE_VALUE;
+	}
+
+	git__free(d);
+	return 0;
+}
+

vendor/libgit2-sys/libgit2/src/win32/dir.h

diff --git a/vendor/libgit2-sys/libgit2/src/win32/dir.h b/vendor/libgit2-sys/libgit2/src/win32/dir.h
new file mode 100644
index 0000000..acd6472
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/dir.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_win32_dir_h__
+#define INCLUDE_win32_dir_h__
+
+#include "common.h"
+
+#include "w32_util.h"
+
+struct git__dirent {
+	int d_ino;
+	git_win32_utf8_path d_name;
+};
+
+typedef struct {
+	HANDLE h;
+	WIN32_FIND_DATAW f;
+	struct git__dirent entry;
+	int first;
+	char dir[GIT_FLEX_ARRAY];
+} git__DIR;
+
+extern git__DIR *git__opendir(const char *);
+extern struct git__dirent *git__readdir(git__DIR *);
+extern int git__readdir_ext(
+	git__DIR *, struct git__dirent *, struct git__dirent **, int *);
+extern void git__rewinddir(git__DIR *);
+extern int git__closedir(git__DIR *);
+
+# ifndef GIT__WIN32_NO_WRAP_DIR
+#	define dirent git__dirent
+#	define DIR git__DIR
+#	define opendir	git__opendir
+#	define readdir	git__readdir
+#   define readdir_r(d,e,r) git__readdir_ext((d),(e),(r),NULL)
+#	define rewinddir git__rewinddir
+#	define closedir git__closedir
+# endif
+
+#endif

vendor/libgit2-sys/libgit2/src/win32/error.c

diff --git a/vendor/libgit2-sys/libgit2/src/win32/error.c b/vendor/libgit2-sys/libgit2/src/win32/error.c
new file mode 100644
index 0000000..3a52fb5
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/error.c
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "error.h"
+
+#include "utf-conv.h"
+
+#ifdef GIT_WINHTTP
+# include <winhttp.h>
+#endif
+
+char *git_win32_get_error_message(DWORD error_code)
+{
+	LPWSTR lpMsgBuf = NULL;
+	HMODULE hModule = NULL;
+	char *utf8_msg = NULL;
+	DWORD dwFlags =
+		FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_IGNORE_INSERTS;
+
+	if (!error_code)
+		return NULL;
+
+#ifdef GIT_WINHTTP
+	/* Errors raised by WinHTTP are not in the system resource table */
+	if (error_code >= WINHTTP_ERROR_BASE &&
+		error_code <= WINHTTP_ERROR_LAST)
+		hModule = GetModuleHandleW(L"winhttp");
+#endif
+
+	GIT_UNUSED(hModule);
+
+	if (hModule)
+		dwFlags |= FORMAT_MESSAGE_FROM_HMODULE;
+	else
+		dwFlags |= FORMAT_MESSAGE_FROM_SYSTEM;
+
+	if (FormatMessageW(dwFlags, hModule, error_code,
+		MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+		(LPWSTR)&lpMsgBuf, 0, NULL)) {
+		/* Convert the message to UTF-8. If this fails, we will
+		 * return NULL, which is a condition expected by the caller */
+		if (git__utf16_to_8_alloc(&utf8_msg, lpMsgBuf) < 0)
+			utf8_msg = NULL;
+
+		LocalFree(lpMsgBuf);
+	}
+
+	return utf8_msg;
+}

vendor/libgit2-sys/libgit2/src/win32/error.h

diff --git a/vendor/libgit2-sys/libgit2/src/win32/error.h b/vendor/libgit2-sys/libgit2/src/win32/error.h
new file mode 100644
index 0000000..9e81141
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/error.h
@@ -0,0 +1,15 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_win32_error_h__
+#define INCLUDE_win32_error_h__
+
+#include "common.h"
+
+extern char *git_win32_get_error_message(DWORD error_code);
+
+#endif

vendor/libgit2-sys/libgit2/src/win32/findfile.c

diff --git a/vendor/libgit2-sys/libgit2/src/win32/findfile.c b/vendor/libgit2-sys/libgit2/src/win32/findfile.c
new file mode 100644
index 0000000..d56aa1f
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/findfile.c
@@ -0,0 +1,228 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "findfile.h"
+
+#include "path_w32.h"
+#include "utf-conv.h"
+#include "path.h"
+
+#define REG_MSYSGIT_INSTALL_LOCAL L"SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall\\Git_is1"
+
+#ifndef _WIN64
+#define REG_MSYSGIT_INSTALL REG_MSYSGIT_INSTALL_LOCAL
+#else
+#define REG_MSYSGIT_INSTALL L"SOFTWARE\\Wow6432Node\\Microsoft\\Windows\\CurrentVersion\\Uninstall\\Git_is1"
+#endif
+
+typedef struct {
+	git_win32_path path;
+	DWORD len;
+} _findfile_path;
+
+static int git_win32__expand_path(_findfile_path *dest, const wchar_t *src)
+{
+	dest->len = ExpandEnvironmentStringsW(src, dest->path, ARRAY_SIZE(dest->path));
+
+	if (!dest->len || dest->len > ARRAY_SIZE(dest->path))
+		return -1;
+
+	return 0;
+}
+
+static int win32_path_to_8(git_buf *dest, const wchar_t *src)
+{
+	git_win32_utf8_path utf8_path;
+
+	if (git_win32_path_to_utf8(utf8_path, src) < 0) {
+		giterr_set(GITERR_OS, "unable to convert path to UTF-8");
+		return -1;
+	}
+
+	/* Convert backslashes to forward slashes */
+	git_path_mkposix(utf8_path);
+
+	return git_buf_sets(dest, utf8_path);
+}
+
+static wchar_t* win32_walkpath(wchar_t *path, wchar_t *buf, size_t buflen)
+{
+	wchar_t term, *base = path;
+
+	assert(path && buf && buflen);
+
+	term = (*path == L'"') ? *path++ : L';';
+
+	for (buflen--; *path && *path != term && buflen; buflen--)
+		*buf++ = *path++;
+
+	*buf = L'\0'; /* reserved a byte via initial subtract */
+
+	while (*path == term || *path == L';')
+		path++;
+
+	return (path != base) ? path : NULL;
+}
+
+static int win32_find_git_in_path(git_buf *buf, const wchar_t *gitexe, const wchar_t *subdir)
+{
+	wchar_t *env = _wgetenv(L"PATH"), lastch;
+	_findfile_path root;
+	size_t gitexe_len = wcslen(gitexe);
+
+	if (!env)
+		return -1;
+
+	while ((env = win32_walkpath(env, root.path, MAX_PATH-1)) && *root.path) {
+		root.len = (DWORD)wcslen(root.path);
+		lastch = root.path[root.len - 1];
+
+		/* ensure trailing slash (MAX_PATH-1 to walkpath guarantees space) */
+		if (lastch != L'/' && lastch != L'\\') {
+			root.path[root.len++] = L'\\';
+			root.path[root.len]   = L'\0';
+		}
+
+		if (root.len + gitexe_len >= MAX_PATH)
+			continue;
+		wcscpy(&root.path[root.len], gitexe);
+
+		if (_waccess(root.path, F_OK) == 0 && root.len > 5) {
+			/* replace "bin\\" or "cmd\\" with subdir */
+			wcscpy(&root.path[root.len - 4], subdir);
+
+			win32_path_to_8(buf, root.path);
+			return 0;
+		}
+	}
+
+	return GIT_ENOTFOUND;
+}
+
+static int win32_find_git_in_registry(
+	git_buf *buf, const HKEY hive, const wchar_t *key, const wchar_t *subdir)
+{
+	HKEY hKey;
+	int error = GIT_ENOTFOUND;
+
+	assert(buf);
+
+	if (!RegOpenKeyExW(hive, key, 0, KEY_READ, &hKey)) {
+		DWORD dwType, cbData;
+		git_win32_path path;
+
+		/* Ensure that the buffer is big enough to have the suffix attached
+		 * after we receive the result. */
+		cbData = (DWORD)(sizeof(path) - wcslen(subdir) * sizeof(wchar_t));
+
+		/* InstallLocation points to the root of the git directory */
+		if (!RegQueryValueExW(hKey, L"InstallLocation", NULL, &dwType, (LPBYTE)path, &cbData) &&
+			dwType == REG_SZ) {
+
+			/* Append the suffix */
+			wcscat(path, subdir);
+
+			/* Convert to UTF-8, with forward slashes, and output the path
+			 * to the provided buffer */
+			if (!win32_path_to_8(buf, path))
+				error = 0;
+		}
+
+		RegCloseKey(hKey);
+	}
+
+	return error;
+}
+
+static int win32_find_existing_dirs(
+	git_buf *out, const wchar_t *tmpl[])
+{
+	_findfile_path path16;
+	git_buf buf = GIT_BUF_INIT;
+
+	git_buf_clear(out);
+
+	for (; *tmpl != NULL; tmpl++) {
+		if (!git_win32__expand_path(&path16, *tmpl) &&
+			path16.path[0] != L'%' &&
+			!_waccess(path16.path, F_OK))
+		{
+			win32_path_to_8(&buf, path16.path);
+
+			if (buf.size)
+				git_buf_join(out, GIT_PATH_LIST_SEPARATOR, out->ptr, buf.ptr);
+		}
+	}
+
+	git_buf_free(&buf);
+
+	return (git_buf_oom(out) ? -1 : 0);
+}
+
+int git_win32__find_system_dirs(git_buf *out, const wchar_t *subdir)
+{
+	git_buf buf = GIT_BUF_INIT;
+
+	/* directories where git.exe & git.cmd are found */
+	if (!win32_find_git_in_path(&buf, L"git.exe", subdir) && buf.size)
+		git_buf_set(out, buf.ptr, buf.size);
+	else
+		git_buf_clear(out);
+
+	if (!win32_find_git_in_path(&buf, L"git.cmd", subdir) && buf.size)
+		git_buf_join(out, GIT_PATH_LIST_SEPARATOR, out->ptr, buf.ptr);
+
+	/* directories where git is installed according to registry */
+	if (!win32_find_git_in_registry(
+			&buf, HKEY_CURRENT_USER, REG_MSYSGIT_INSTALL_LOCAL, subdir) && buf.size)
+		git_buf_join(out, GIT_PATH_LIST_SEPARATOR, out->ptr, buf.ptr);
+
+	if (!win32_find_git_in_registry(
+			&buf, HKEY_LOCAL_MACHINE, REG_MSYSGIT_INSTALL, subdir) && buf.size)
+		git_buf_join(out, GIT_PATH_LIST_SEPARATOR, out->ptr, buf.ptr);
+
+	git_buf_free(&buf);
+
+	return (git_buf_oom(out) ? -1 : 0);
+}
+
+int git_win32__find_global_dirs(git_buf *out)
+{
+	static const wchar_t *global_tmpls[4] = {
+		L"%HOME%\\",
+		L"%HOMEDRIVE%%HOMEPATH%\\",
+		L"%USERPROFILE%\\",
+		NULL,
+	};
+
+	return win32_find_existing_dirs(out, global_tmpls);
+}
+
+int git_win32__find_xdg_dirs(git_buf *out)
+{
+	static const wchar_t *global_tmpls[7] = {
+		L"%XDG_CONFIG_HOME%\\git",
+		L"%APPDATA%\\git",
+		L"%LOCALAPPDATA%\\git",
+		L"%HOME%\\.config\\git",
+		L"%HOMEDRIVE%%HOMEPATH%\\.config\\git",
+		L"%USERPROFILE%\\.config\\git",
+		NULL,
+	};
+
+	return win32_find_existing_dirs(out, global_tmpls);
+}
+
+int git_win32__find_programdata_dirs(git_buf *out)
+{
+	static const wchar_t *programdata_tmpls[2] = {
+		L"%PROGRAMDATA%\\Git",
+		NULL,
+	};
+
+	return win32_find_existing_dirs(out, programdata_tmpls);
+}

vendor/libgit2-sys/libgit2/src/win32/findfile.h

diff --git a/vendor/libgit2-sys/libgit2/src/win32/findfile.h b/vendor/libgit2-sys/libgit2/src/win32/findfile.h
new file mode 100644
index 0000000..e7bcf94
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/findfile.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_win32_findfile_h__
+#define INCLUDE_win32_findfile_h__
+
+#include "common.h"
+
+extern int git_win32__find_system_dirs(git_buf *out, const wchar_t *subpath);
+extern int git_win32__find_global_dirs(git_buf *out);
+extern int git_win32__find_xdg_dirs(git_buf *out);
+extern int git_win32__find_programdata_dirs(git_buf *out);
+
+#endif
+

vendor/libgit2-sys/libgit2/src/win32/git2.rc

diff --git a/vendor/libgit2-sys/libgit2/src/win32/git2.rc b/vendor/libgit2-sys/libgit2/src/win32/git2.rc
new file mode 100644
index 0000000..3571bc6
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/git2.rc
@@ -0,0 +1,44 @@
+#include <winver.h>
+#include "../../include/git2/version.h"
+
+#ifndef LIBGIT2_FILENAME
+# define LIBGIT2_FILENAME "git2"
+#endif
+
+#ifndef LIBGIT2_COMMENTS
+# define LIBGIT2_COMMENTS "For more information visit http://libgit2.github.com/"
+#endif
+
+VS_VERSION_INFO		VERSIONINFO	MOVEABLE IMPURE LOADONCALL DISCARDABLE
+  FILEVERSION		LIBGIT2_VER_MAJOR,LIBGIT2_VER_MINOR,LIBGIT2_VER_REVISION,LIBGIT2_VER_PATCH
+  PRODUCTVERSION	LIBGIT2_VER_MAJOR,LIBGIT2_VER_MINOR,LIBGIT2_VER_REVISION,LIBGIT2_VER_PATCH
+  FILEFLAGSMASK		VS_FFI_FILEFLAGSMASK
+#ifdef _DEBUG
+  FILEFLAGS		VS_FF_DEBUG
+#else
+  FILEFLAGS		0
+#endif
+  FILEOS		VOS_NT_WINDOWS32
+  FILETYPE		VFT_DLL
+  FILESUBTYPE	VFT2_UNKNOWN
+BEGIN
+  BLOCK "StringFileInfo"
+  BEGIN
+    BLOCK "040904E4"
+    //language ID = U.S. English, char set = Windows, Multilingual
+    BEGIN
+      VALUE "FileDescription",	"libgit2 - the Git linkable library\0"
+      VALUE "FileVersion",	LIBGIT2_VERSION "\0"
+      VALUE "InternalName",	LIBGIT2_FILENAME ".dll\0"
+      VALUE "LegalCopyright",	"Copyright (C) the libgit2 contributors. All rights reserved.\0"
+      VALUE "OriginalFilename",	LIBGIT2_FILENAME ".dll\0"
+      VALUE "ProductName",	"libgit2\0"
+      VALUE "ProductVersion",	LIBGIT2_VERSION "\0"
+      VALUE "Comments",		LIBGIT2_COMMENTS "\0"
+    END
+  END
+  BLOCK "VarFileInfo"
+  BEGIN
+    VALUE "Translation", 0x0409, 1252
+  END
+END

vendor/libgit2-sys/libgit2/src/win32/map.c

diff --git a/vendor/libgit2-sys/libgit2/src/win32/map.c b/vendor/libgit2-sys/libgit2/src/win32/map.c
new file mode 100644
index 0000000..6a17aeb
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/map.c
@@ -0,0 +1,143 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "map.h"
+#include <errno.h>
+
+#ifndef NO_MMAP
+
+static DWORD get_page_size(void)
+{
+	static DWORD page_size;
+	SYSTEM_INFO sys;
+
+	if (!page_size) {
+		GetSystemInfo(&sys);
+		page_size = sys.dwPageSize;
+	}
+
+	return page_size;
+}
+
+static DWORD get_allocation_granularity(void)
+{
+	static DWORD granularity;
+	SYSTEM_INFO sys;
+
+	if (!granularity) {
+		GetSystemInfo(&sys);
+		granularity = sys.dwAllocationGranularity;
+	}
+
+	return granularity;
+}
+
+int git__page_size(size_t *page_size)
+{
+	*page_size = get_page_size();
+	return 0;
+}
+
+int git__mmap_alignment(size_t *page_size)
+{
+	*page_size = get_allocation_granularity();
+	return 0;
+}
+
+int p_mmap(git_map *out, size_t len, int prot, int flags, int fd, git_off_t offset)
+{
+	HANDLE fh = (HANDLE)_get_osfhandle(fd);
+	DWORD alignment = get_allocation_granularity();
+	DWORD fmap_prot = 0;
+	DWORD view_prot = 0;
+	DWORD off_low = 0;
+	DWORD off_hi = 0;
+	git_off_t page_start;
+	git_off_t page_offset;
+
+	GIT_MMAP_VALIDATE(out, len, prot, flags);
+
+	out->data = NULL;
+	out->len = 0;
+	out->fmh = NULL;
+
+	if (fh == INVALID_HANDLE_VALUE) {
+		errno = EBADF;
+		giterr_set(GITERR_OS, "failed to mmap. Invalid handle value");
+		return -1;
+	}
+
+	if (prot & GIT_PROT_WRITE)
+		fmap_prot |= PAGE_READWRITE;
+	else if (prot & GIT_PROT_READ)
+		fmap_prot |= PAGE_READONLY;
+
+	if (prot & GIT_PROT_WRITE)
+		view_prot |= FILE_MAP_WRITE;
+	if (prot & GIT_PROT_READ)
+		view_prot |= FILE_MAP_READ;
+
+	page_start = (offset / alignment) * alignment;
+	page_offset = offset - page_start;
+
+	if (page_offset != 0) { /* offset must be multiple of the allocation granularity */
+		errno = EINVAL;
+		giterr_set(GITERR_OS, "failed to mmap. Offset must be multiple of allocation granularity");
+		return -1;
+	}
+
+	out->fmh = CreateFileMapping(fh, NULL, fmap_prot, 0, 0, NULL);
+	if (!out->fmh || out->fmh == INVALID_HANDLE_VALUE) {
+		giterr_set(GITERR_OS, "failed to mmap. Invalid handle value");
+		out->fmh = NULL;
+		return -1;
+	}
+
+	assert(sizeof(git_off_t) == 8);
+
+	off_low = (DWORD)(page_start);
+	off_hi = (DWORD)(page_start >> 32);
+	out->data = MapViewOfFile(out->fmh, view_prot, off_hi, off_low, len);
+	if (!out->data) {
+		giterr_set(GITERR_OS, "failed to mmap. No data written");
+		CloseHandle(out->fmh);
+		out->fmh = NULL;
+		return -1;
+	}
+	out->len = len;
+
+	return 0;
+}
+
+int p_munmap(git_map *map)
+{
+	int error = 0;
+
+	assert(map != NULL);
+
+	if (map->data) {
+		if (!UnmapViewOfFile(map->data)) {
+			giterr_set(GITERR_OS, "failed to munmap. Could not unmap view of file");
+			error = -1;
+		}
+		map->data = NULL;
+	}
+
+	if (map->fmh) {
+		if (!CloseHandle(map->fmh)) {
+			giterr_set(GITERR_OS, "failed to munmap. Could not close handle");
+			error = -1;
+		}
+		map->fmh = NULL;
+	}
+
+	return error;
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/win32/mingw-compat.h

diff --git a/vendor/libgit2-sys/libgit2/src/win32/mingw-compat.h b/vendor/libgit2-sys/libgit2/src/win32/mingw-compat.h
new file mode 100644
index 0000000..aa2bef9
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/mingw-compat.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_win32_mingw_compat_h__
+#define INCLUDE_win32_mingw_compat_h__
+
+#if defined(__MINGW32__)
+
+#undef stat
+
+#if _WIN32_WINNT < 0x0600 && !defined(__MINGW64_VERSION_MAJOR)
+#undef MemoryBarrier
+void __mingworg_MemoryBarrier(void);
+#define MemoryBarrier __mingworg_MemoryBarrier
+#define VOLUME_NAME_DOS 0x0
+#endif
+
+#endif
+
+#endif

vendor/libgit2-sys/libgit2/src/win32/msvc-compat.h

diff --git a/vendor/libgit2-sys/libgit2/src/win32/msvc-compat.h b/vendor/libgit2-sys/libgit2/src/win32/msvc-compat.h
new file mode 100644
index 0000000..ea77820
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/msvc-compat.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_win32_msvc_compat_h__
+#define INCLUDE_win32_msvc_compat_h__
+
+#if defined(_MSC_VER)
+
+typedef unsigned short mode_t;
+typedef SSIZE_T ssize_t;
+
+#define strcasecmp(s1, s2) _stricmp(s1, s2)
+#define strncasecmp(s1, s2, c) _strnicmp(s1, s2, c)
+
+#endif
+
+#define GIT_STDLIB_CALL __cdecl
+
+#endif

vendor/libgit2-sys/libgit2/src/win32/path_w32.c

diff --git a/vendor/libgit2-sys/libgit2/src/win32/path_w32.c b/vendor/libgit2-sys/libgit2/src/win32/path_w32.c
new file mode 100644
index 0000000..5e24260
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/path_w32.c
@@ -0,0 +1,382 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "path_w32.h"
+
+#include "path.h"
+#include "utf-conv.h"
+#include "posix.h"
+#include "reparse.h"
+#include "dir.h"
+
+#define PATH__NT_NAMESPACE     L"\\\\?\\"
+#define PATH__NT_NAMESPACE_LEN 4
+
+#define PATH__ABSOLUTE_LEN     3
+
+#define path__is_nt_namespace(p) \
+	(((p)[0] == '\\' && (p)[1] == '\\' && (p)[2] == '?' && (p)[3] == '\\') || \
+	 ((p)[0] == '/' && (p)[1] == '/' && (p)[2] == '?' && (p)[3] == '/'))
+
+#define path__is_unc(p) \
+	(((p)[0] == '\\' && (p)[1] == '\\') || ((p)[0] == '/' && (p)[1] == '/'))
+
+GIT_INLINE(int) path__cwd(wchar_t *path, int size)
+{
+	int len;
+
+	if ((len = GetCurrentDirectoryW(size, path)) == 0) {
+		errno = GetLastError() == ERROR_ACCESS_DENIED ? EACCES : ENOENT;
+		return -1;
+	} else if (len > size) {
+		errno = ENAMETOOLONG;
+		return -1;
+	}
+
+	/* The Win32 APIs may return "\\?\" once you've used it first.
+	 * But it may not.  What a gloriously predictible API!
+	 */
+	if (wcsncmp(path, PATH__NT_NAMESPACE, PATH__NT_NAMESPACE_LEN))
+		return len;
+
+	len -= PATH__NT_NAMESPACE_LEN;
+
+	memmove(path, path + PATH__NT_NAMESPACE_LEN, sizeof(wchar_t) * len);
+	return len;
+}
+
+static wchar_t *path__skip_server(wchar_t *path)
+{
+	wchar_t *c;
+
+	for (c = path; *c; c++) {
+		if (git_path_is_dirsep(*c))
+			return c + 1;
+	}
+
+	return c;
+}
+
+static wchar_t *path__skip_prefix(wchar_t *path)
+{
+	if (path__is_nt_namespace(path)) {
+		path += PATH__NT_NAMESPACE_LEN;
+
+		if (wcsncmp(path, L"UNC\\", 4) == 0)
+			path = path__skip_server(path + 4);
+		else if (git_path_is_absolute(path))
+			path += PATH__ABSOLUTE_LEN;
+	} else if (git_path_is_absolute(path)) {
+		path += PATH__ABSOLUTE_LEN;
+	} else if (path__is_unc(path)) {
+		path = path__skip_server(path + 2);
+	}
+
+	return path;
+}
+
+int git_win32_path_canonicalize(git_win32_path path)
+{
+	wchar_t *base, *from, *to, *next;
+	size_t len;
+
+	base = to = path__skip_prefix(path);
+
+	/* Unposixify if the prefix */
+	for (from = path; from < to; from++) {
+		if (*from == L'/')
+			*from = L'\\';
+	}
+
+	while (*from) {
+		for (next = from; *next; ++next) {
+			if (*next == L'/') {
+				*next = L'\\';
+				break;
+			}
+
+			if (*next == L'\\')
+				break;
+		}
+
+		len = next - from;
+
+		if (len == 1 && from[0] == L'.')
+			/* do nothing with singleton dot */;
+
+		else if (len == 2 && from[0] == L'.' && from[1] == L'.') {
+			if (to == base) {
+				/* no more path segments to strip, eat the "../" */
+				if (*next == L'\\')
+					len++;
+
+				base = to;
+			} else {
+				/* back up a path segment */
+				while (to > base && to[-1] == L'\\') to--;
+				while (to > base && to[-1] != L'\\') to--;
+			}
+		} else {
+			if (*next == L'\\' && *from != L'\\')
+				len++;
+
+			if (to != from)
+				memmove(to, from, sizeof(wchar_t) * len);
+
+			to += len;
+		}
+
+		from += len;
+
+		while (*from == L'\\') from++;
+	}
+
+	/* Strip trailing backslashes */
+	while (to > base && to[-1] == L'\\') to--;
+
+	*to = L'\0';
+
+	return (to - path);
+}
+
+int git_win32_path__cwd(wchar_t *out, size_t len)
+{
+	int cwd_len;
+
+	if ((cwd_len = path__cwd(out, len)) < 0)
+		return -1;
+
+	/* UNC paths */
+	if (wcsncmp(L"\\\\", out, 2) == 0) {
+		/* Our buffer must be at least 5 characters larger than the
+		 * current working directory:  we swallow one of the leading
+		 * '\'s, but we we add a 'UNC' specifier to the path, plus
+		 * a trailing directory separator, plus a NUL.
+		 */
+		if (cwd_len > MAX_PATH - 4) {
+			errno = ENAMETOOLONG;
+			return -1;
+		}
+
+		memmove(out+2, out, sizeof(wchar_t) * cwd_len);
+		out[0] = L'U';
+		out[1] = L'N';
+		out[2] = L'C';
+
+		cwd_len += 2;
+	}
+
+	/* Our buffer must be at least 2 characters larger than the current
+	 * working directory.  (One character for the directory separator,
+	 * one for the null.
+	 */
+	else if (cwd_len > MAX_PATH - 2) {
+		errno = ENAMETOOLONG;
+		return -1;
+	}
+
+	return cwd_len;
+}
+
+int git_win32_path_from_utf8(git_win32_path out, const char *src)
+{
+	wchar_t *dest = out;
+
+	/* All win32 paths are in NT-prefixed format, beginning with "\\?\". */
+	memcpy(dest, PATH__NT_NAMESPACE, sizeof(wchar_t) * PATH__NT_NAMESPACE_LEN);
+	dest += PATH__NT_NAMESPACE_LEN;
+
+	/* See if this is an absolute path (beginning with a drive letter) */
+	if (git_path_is_absolute(src)) {
+		if (git__utf8_to_16(dest, MAX_PATH, src) < 0)
+			goto on_error;
+	}
+	/* File-prefixed NT-style paths beginning with \\?\ */
+	else if (path__is_nt_namespace(src)) {
+		/* Skip the NT prefix, the destination already contains it */
+		if (git__utf8_to_16(dest, MAX_PATH, src + PATH__NT_NAMESPACE_LEN) < 0)
+			goto on_error;
+	}
+	/* UNC paths */
+	else if (path__is_unc(src)) {
+		memcpy(dest, L"UNC\\", sizeof(wchar_t) * 4);
+		dest += 4;
+
+		/* Skip the leading "\\" */
+		if (git__utf8_to_16(dest, MAX_PATH - 2, src + 2) < 0)
+			goto on_error;
+	}
+	/* Absolute paths omitting the drive letter */
+	else if (src[0] == '\\' || src[0] == '/') {
+		if (path__cwd(dest, MAX_PATH) < 0)
+			goto on_error;
+
+		if (!git_path_is_absolute(dest)) {
+			errno = ENOENT;
+			goto on_error;
+		}
+
+		/* Skip the drive letter specification ("C:") */	
+		if (git__utf8_to_16(dest + 2, MAX_PATH - 2, src) < 0)
+			goto on_error;
+	}
+	/* Relative paths */
+	else {
+		int cwd_len;
+
+		if ((cwd_len = git_win32_path__cwd(dest, MAX_PATH)) < 0)
+			goto on_error;
+
+		dest[cwd_len++] = L'\\';
+
+		if (git__utf8_to_16(dest + cwd_len, MAX_PATH - cwd_len, src) < 0)
+			goto on_error;
+	}
+
+	return git_win32_path_canonicalize(out);
+
+on_error:
+	/* set windows error code so we can use its error message */
+	if (errno == ENAMETOOLONG)
+		SetLastError(ERROR_FILENAME_EXCED_RANGE);
+
+	return -1;
+}
+
+int git_win32_path_to_utf8(git_win32_utf8_path dest, const wchar_t *src)
+{
+	char *out = dest;
+	int len;
+
+	/* Strip NT namespacing "\\?\" */
+	if (path__is_nt_namespace(src)) {
+		src += 4;
+
+		/* "\\?\UNC\server\share" -> "\\server\share" */
+		if (wcsncmp(src, L"UNC\\", 4) == 0) {
+			src += 4;
+
+			memcpy(dest, "\\\\", 2);
+			out = dest + 2;
+		}
+	}
+
+	if ((len = git__utf16_to_8(out, GIT_WIN_PATH_UTF8, src)) < 0)
+		return len;
+
+	git_path_mkposix(dest);
+
+	return len;
+}
+
+char *git_win32_path_8dot3_name(const char *path)
+{
+	git_win32_path longpath, shortpath;
+	wchar_t *start;
+	char *shortname;
+	int len, namelen = 1;
+
+	if (git_win32_path_from_utf8(longpath, path) < 0)
+		return NULL;
+
+	len = GetShortPathNameW(longpath, shortpath, GIT_WIN_PATH_UTF16);
+
+	while (len && shortpath[len-1] == L'\\')
+		shortpath[--len] = L'\0';
+
+	if (len == 0 || len >= GIT_WIN_PATH_UTF16)
+		return NULL;
+
+	for (start = shortpath + (len - 1);
+		start > shortpath && *(start-1) != '/' && *(start-1) != '\\';
+		start--)
+		namelen++;
+
+	/* We may not have actually been given a short name.  But if we have,
+	 * it will be in the ASCII byte range, so we don't need to worry about
+	 * multi-byte sequences and can allocate naively.
+	 */
+	if (namelen > 12 || (shortname = git__malloc(namelen + 1)) == NULL)
+		return NULL;
+
+	if ((len = git__utf16_to_8(shortname, namelen + 1, start)) < 0)
+		return NULL;
+
+	return shortname;
+}
+
+static bool path_is_volume(wchar_t *target, size_t target_len)
+{
+	return (target_len && wcsncmp(target, L"\\??\\Volume{", 11) == 0);
+}
+
+/* On success, returns the length, in characters, of the path stored in dest.
+* On failure, returns a negative value. */
+int git_win32_path_readlink_w(git_win32_path dest, const git_win32_path path)
+{
+	BYTE buf[MAXIMUM_REPARSE_DATA_BUFFER_SIZE];
+	GIT_REPARSE_DATA_BUFFER *reparse_buf = (GIT_REPARSE_DATA_BUFFER *)buf;
+	HANDLE handle = NULL;
+	DWORD ioctl_ret;
+	wchar_t *target;
+	size_t target_len;
+
+	int error = -1;
+
+	handle = CreateFileW(path, GENERIC_READ,
+		FILE_SHARE_READ | FILE_SHARE_DELETE, NULL, OPEN_EXISTING,
+		FILE_FLAG_OPEN_REPARSE_POINT | FILE_FLAG_BACKUP_SEMANTICS, NULL);
+
+	if (handle == INVALID_HANDLE_VALUE) {
+		errno = ENOENT;
+		return -1;
+	}
+
+	if (!DeviceIoControl(handle, FSCTL_GET_REPARSE_POINT, NULL, 0,
+		reparse_buf, sizeof(buf), &ioctl_ret, NULL)) {
+		errno = EINVAL;
+		goto on_error;
+	}
+
+	switch (reparse_buf->ReparseTag) {
+	case IO_REPARSE_TAG_SYMLINK:
+		target = reparse_buf->SymbolicLinkReparseBuffer.PathBuffer +
+			(reparse_buf->SymbolicLinkReparseBuffer.SubstituteNameOffset / sizeof(WCHAR));
+		target_len = reparse_buf->SymbolicLinkReparseBuffer.SubstituteNameLength / sizeof(WCHAR);
+	break;
+	case IO_REPARSE_TAG_MOUNT_POINT:
+		target = reparse_buf->MountPointReparseBuffer.PathBuffer +
+			(reparse_buf->MountPointReparseBuffer.SubstituteNameOffset / sizeof(WCHAR));
+		target_len = reparse_buf->MountPointReparseBuffer.SubstituteNameLength / sizeof(WCHAR);
+	break;
+	default:
+		errno = EINVAL;
+		goto on_error;
+	}
+
+	if (path_is_volume(target, target_len)) {
+		/* This path is a reparse point that represents another volume mounted
+		* at this location, it is not a symbolic link our input was canonical.
+		*/
+		errno = EINVAL;
+		error = -1;
+	} else if (target_len) {
+		/* The path may need to have a prefix removed. */
+		target_len = git_win32__canonicalize_path(target, target_len);
+
+		/* Need one additional character in the target buffer
+		* for the terminating NULL. */
+		if (GIT_WIN_PATH_UTF16 > target_len) {
+			wcscpy(dest, target);
+			error = (int)target_len;
+		}
+	}
+
+on_error:
+	CloseHandle(handle);
+	return error;
+}

vendor/libgit2-sys/libgit2/src/win32/path_w32.h

diff --git a/vendor/libgit2-sys/libgit2/src/win32/path_w32.h b/vendor/libgit2-sys/libgit2/src/win32/path_w32.h
new file mode 100644
index 0000000..83ffd1f
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/path_w32.h
@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_win32_path_w32_h__
+#define INCLUDE_win32_path_w32_h__
+
+#include "common.h"
+
+#include "vector.h"
+
+/*
+ * Provides a large enough buffer to support Windows paths:  MAX_PATH is
+ * 260, corresponding to a maximum path length of 259 characters plus a
+ * NULL terminator.  Prefixing with "\\?\" adds 4 characters, but if the
+ * original was a UNC path, then we turn "\\server\share" into
+ * "\\?\UNC\server\share".  So we replace the first two characters with
+ * 8 characters, a net gain of 6, so the maximum length is MAX_PATH+6.
+ */
+#define GIT_WIN_PATH_UTF16		MAX_PATH+6
+
+/* Maximum size of a UTF-8 Win32 path.  We remove the "\\?\" or "\\?\UNC\"
+ * prefixes for presentation, bringing us back to 259 (non-NULL)
+ * characters.  UTF-8 does have 4-byte sequences, but they are encoded in
+ * UTF-16 using surrogate pairs, which takes up the space of two characters.
+ * Two characters in the range U+0800 -> U+FFFF take up more space in UTF-8
+ * (6 bytes) than one surrogate pair (4 bytes).
+ */
+#define GIT_WIN_PATH_UTF8		(259 * 3 + 1)
+
+/*
+ * The length of a Windows "shortname", for 8.3 compatibility.
+ */
+#define GIT_WIN_PATH_SHORTNAME  13
+
+/* Win32 path types */
+typedef wchar_t git_win32_path[GIT_WIN_PATH_UTF16];
+typedef char git_win32_utf8_path[GIT_WIN_PATH_UTF8];
+
+/**
+ * Create a Win32 path (in UCS-2 format) from a UTF-8 string.
+ *
+ * @param dest The buffer to receive the wide string.
+ * @param src The UTF-8 string to convert.
+ * @return The length of the wide string, in characters (not counting the NULL terminator), or < 0 for failure
+ */
+extern int git_win32_path_from_utf8(git_win32_path dest, const char *src);
+
+/**
+ * Canonicalize a Win32 UCS-2 path so that it is suitable for delivery to the
+ * Win32 APIs: remove multiple directory separators, squashing to a single one,
+ * strip trailing directory separators, ensure directory separators are all
+ * canonical (always backslashes, never forward slashes) and process any
+ * directory entries of '.' or '..'.
+ *
+ * This processes the buffer in place.
+ *
+ * @param path The buffer to process
+ * @return The new length of the buffer, in wchar_t's (not counting the NULL terminator)
+ */
+extern int git_win32_path_canonicalize(git_win32_path path);
+
+/**
+ * Create an internal format (posix-style) UTF-8 path from a Win32 UCS-2 path.
+ *
+ * @param dest The buffer to receive the UTF-8 string.
+ * @param src The wide string to convert.
+ * @return The length of the UTF-8 string, in bytes (not counting the NULL terminator), or < 0 for failure
+ */
+extern int git_win32_path_to_utf8(git_win32_utf8_path dest, const wchar_t *src);
+
+/**
+ * Get the short name for the terminal path component in the given path.
+ * For example, given "C:\Foo\Bar\Asdf.txt", this will return the short name
+ * for the file "Asdf.txt".
+ *
+ * @param path The given path in UTF-8
+ * @return The name of the shortname for the given path
+ */
+extern char *git_win32_path_8dot3_name(const char *path);
+
+extern int git_win32_path_readlink_w(git_win32_path dest, const git_win32_path path);
+
+#endif

vendor/libgit2-sys/libgit2/src/win32/posix.h

diff --git a/vendor/libgit2-sys/libgit2/src/win32/posix.h b/vendor/libgit2-sys/libgit2/src/win32/posix.h
new file mode 100644
index 0000000..d5ab2e8
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/posix.h
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_win32_posix_h__
+#define INCLUDE_win32_posix_h__
+
+#include "common.h"
+#include "../posix.h"
+#include "win32-compat.h"
+#include "path_w32.h"
+#include "utf-conv.h"
+#include "dir.h"
+
+extern unsigned long git_win32__createfile_sharemode;
+extern int git_win32__retries;
+
+typedef SOCKET GIT_SOCKET;
+
+#define p_lseek(f,n,w) _lseeki64(f, n, w)
+
+extern int p_fstat(int fd, struct stat *buf);
+extern int p_lstat(const char *file_name, struct stat *buf);
+extern int p_stat(const char* path, struct stat *buf);
+
+extern int p_utimes(const char *filename, const struct p_timeval times[2]);
+extern int p_futimes(int fd, const struct p_timeval times[2]);
+
+extern int p_readlink(const char *path, char *buf, size_t bufsiz);
+extern int p_symlink(const char *old, const char *new);
+extern int p_link(const char *old, const char *new);
+extern int p_unlink(const char *path);
+extern int p_mkdir(const char *path, mode_t mode);
+extern int p_fsync(int fd);
+extern char *p_realpath(const char *orig_path, char *buffer);
+
+extern int p_recv(GIT_SOCKET socket, void *buffer, size_t length, int flags);
+extern int p_send(GIT_SOCKET socket, const void *buffer, size_t length, int flags);
+extern int p_inet_pton(int af, const char* src, void* dst);
+
+extern int p_vsnprintf(char *buffer, size_t count, const char *format, va_list argptr);
+extern int p_snprintf(char *buffer, size_t count, const char *format, ...) GIT_FORMAT_PRINTF(3, 4);
+extern int p_mkstemp(char *tmp_path);
+extern int p_chdir(const char* path);
+extern int p_chmod(const char* path, mode_t mode);
+extern int p_rmdir(const char* path);
+extern int p_access(const char* path, mode_t mode);
+extern int p_ftruncate(int fd, git_off_t size);
+
+/* p_lstat is almost but not quite POSIX correct.  Specifically, the use of
+ * ENOTDIR is wrong, in that it does not mean precisely that a non-directory
+ * entry was encountered.  Making it correct is potentially expensive,
+ * however, so this is a separate version of p_lstat to use when correct
+ * POSIX ENOTDIR semantics is required.
+ */
+extern int p_lstat_posixly(const char *filename, struct stat *buf);
+
+extern struct tm * p_localtime_r(const time_t *timer, struct tm *result);
+extern struct tm * p_gmtime_r(const time_t *timer, struct tm *result);
+
+/* Use the bundled regcomp */
+#define p_regcomp regcomp
+
+#endif

vendor/libgit2-sys/libgit2/src/win32/posix_w32.c

diff --git a/vendor/libgit2-sys/libgit2/src/win32/posix_w32.c b/vendor/libgit2-sys/libgit2/src/win32/posix_w32.c
new file mode 100644
index 0000000..f51e1e5
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/posix_w32.c
@@ -0,0 +1,952 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+
+#include "../posix.h"
+#include "../fileops.h"
+#include "path.h"
+#include "path_w32.h"
+#include "utf-conv.h"
+#include "repository.h"
+#include "reparse.h"
+#include "global.h"
+#include "buffer.h"
+#include <errno.h>
+#include <io.h>
+#include <fcntl.h>
+#include <ws2tcpip.h>
+
+#ifndef FILE_NAME_NORMALIZED
+# define FILE_NAME_NORMALIZED 0
+#endif
+
+#ifndef IO_REPARSE_TAG_SYMLINK
+#define IO_REPARSE_TAG_SYMLINK (0xA000000CL)
+#endif
+
+/* Allowable mode bits on Win32.  Using mode bits that are not supported on
+ * Win32 (eg S_IRWXU) is generally ignored, but Wine warns loudly about it
+ * so we simply remove them.
+ */
+#define WIN32_MODE_MASK (_S_IREAD | _S_IWRITE)
+
+/* GetFinalPathNameByHandleW signature */
+typedef DWORD(WINAPI *PFGetFinalPathNameByHandleW)(HANDLE, LPWSTR, DWORD, DWORD);
+
+unsigned long git_win32__createfile_sharemode =
+ FILE_SHARE_READ | FILE_SHARE_WRITE;
+int git_win32__retries = 10;
+
+GIT_INLINE(void) set_errno(void)
+{
+	switch (GetLastError()) {
+	case ERROR_FILE_NOT_FOUND:
+	case ERROR_PATH_NOT_FOUND:
+	case ERROR_INVALID_DRIVE:
+	case ERROR_NO_MORE_FILES:
+	case ERROR_BAD_NETPATH:
+	case ERROR_BAD_NET_NAME:
+	case ERROR_BAD_PATHNAME:
+	case ERROR_FILENAME_EXCED_RANGE:
+		errno = ENOENT;
+		break;
+	case ERROR_BAD_ENVIRONMENT:
+		errno = E2BIG;
+		break;
+	case ERROR_BAD_FORMAT:
+	case ERROR_INVALID_STARTING_CODESEG:
+	case ERROR_INVALID_STACKSEG:
+	case ERROR_INVALID_MODULETYPE:
+	case ERROR_INVALID_EXE_SIGNATURE:
+	case ERROR_EXE_MARKED_INVALID:
+	case ERROR_BAD_EXE_FORMAT:
+	case ERROR_ITERATED_DATA_EXCEEDS_64k:
+	case ERROR_INVALID_MINALLOCSIZE:
+	case ERROR_DYNLINK_FROM_INVALID_RING:
+	case ERROR_IOPL_NOT_ENABLED:
+	case ERROR_INVALID_SEGDPL:
+	case ERROR_AUTODATASEG_EXCEEDS_64k:
+	case ERROR_RING2SEG_MUST_BE_MOVABLE:
+	case ERROR_RELOC_CHAIN_XEEDS_SEGLIM:
+	case ERROR_INFLOOP_IN_RELOC_CHAIN:
+		errno = ENOEXEC;
+		break;
+	case ERROR_INVALID_HANDLE:
+	case ERROR_INVALID_TARGET_HANDLE:
+	case ERROR_DIRECT_ACCESS_HANDLE:
+		errno = EBADF;
+		break;
+	case ERROR_WAIT_NO_CHILDREN:
+	case ERROR_CHILD_NOT_COMPLETE:
+		errno = ECHILD;
+		break;
+	case ERROR_NO_PROC_SLOTS:
+	case ERROR_MAX_THRDS_REACHED:
+	case ERROR_NESTING_NOT_ALLOWED:
+		errno = EAGAIN;
+		break;
+	case ERROR_ARENA_TRASHED:
+	case ERROR_NOT_ENOUGH_MEMORY:
+	case ERROR_INVALID_BLOCK:
+	case ERROR_NOT_ENOUGH_QUOTA:
+		errno = ENOMEM;
+		break;
+	case ERROR_ACCESS_DENIED:
+	case ERROR_CURRENT_DIRECTORY:
+	case ERROR_WRITE_PROTECT:
+	case ERROR_BAD_UNIT:
+	case ERROR_NOT_READY:
+	case ERROR_BAD_COMMAND:
+	case ERROR_CRC:
+	case ERROR_BAD_LENGTH:
+	case ERROR_SEEK:
+	case ERROR_NOT_DOS_DISK:
+	case ERROR_SECTOR_NOT_FOUND:
+	case ERROR_OUT_OF_PAPER:
+	case ERROR_WRITE_FAULT:
+	case ERROR_READ_FAULT:
+	case ERROR_GEN_FAILURE:
+	case ERROR_SHARING_VIOLATION:
+	case ERROR_LOCK_VIOLATION:
+	case ERROR_WRONG_DISK:
+	case ERROR_SHARING_BUFFER_EXCEEDED:
+	case ERROR_NETWORK_ACCESS_DENIED:
+	case ERROR_CANNOT_MAKE:
+	case ERROR_FAIL_I24:
+	case ERROR_DRIVE_LOCKED:
+	case ERROR_SEEK_ON_DEVICE:
+	case ERROR_NOT_LOCKED:
+	case ERROR_LOCK_FAILED:
+		errno = EACCES;
+		break;
+	case ERROR_FILE_EXISTS:
+	case ERROR_ALREADY_EXISTS:
+		errno = EEXIST;
+		break;
+	case ERROR_NOT_SAME_DEVICE:
+		errno = EXDEV;
+		break;
+	case ERROR_INVALID_FUNCTION:
+	case ERROR_INVALID_ACCESS:
+	case ERROR_INVALID_DATA:
+	case ERROR_INVALID_PARAMETER:
+	case ERROR_NEGATIVE_SEEK:
+		errno = EINVAL;
+		break;
+	case ERROR_TOO_MANY_OPEN_FILES:
+		errno = EMFILE;
+		break;
+	case ERROR_DISK_FULL:
+		errno = ENOSPC;
+		break;
+	case ERROR_BROKEN_PIPE:
+		errno = EPIPE;
+		break;
+	case ERROR_DIR_NOT_EMPTY:
+		errno = ENOTEMPTY;
+		break;
+	default:
+		errno = EINVAL;
+	}
+}
+
+GIT_INLINE(bool) last_error_retryable(void)
+{
+	int os_error = GetLastError();
+
+	return (os_error == ERROR_SHARING_VIOLATION ||
+		os_error == ERROR_ACCESS_DENIED);
+}
+
+#define do_with_retries(fn, remediation) \
+	do {                                                             \
+		int __retry, __ret;                                          \
+		for (__retry = git_win32__retries; __retry; __retry--) {     \
+			if ((__ret = (fn)) != GIT_RETRY)                         \
+				return __ret;                                        \
+			if (__retry > 1 && (__ret = (remediation)) != 0) {       \
+				if (__ret == GIT_RETRY)                              \
+					continue;                                        \
+				return __ret;                                        \
+			}                                                        \
+			Sleep(5);                                                \
+		}                                                            \
+		return -1;                                                   \
+	} while (0)                                                      \
+
+static int ensure_writable(wchar_t *path)
+{
+	DWORD attrs;
+
+	if ((attrs = GetFileAttributesW(path)) == INVALID_FILE_ATTRIBUTES)
+		goto on_error;
+
+	if ((attrs & FILE_ATTRIBUTE_READONLY) == 0)
+		return 0;
+
+	if (!SetFileAttributesW(path, (attrs & ~FILE_ATTRIBUTE_READONLY)))
+		goto on_error;
+
+	return GIT_RETRY;
+
+on_error:
+	set_errno();
+	return -1;
+}
+
+/**
+ * Truncate or extend file.
+ *
+ * We now take a "git_off_t" rather than "long" because
+ * files may be longer than 2Gb.
+ */
+int p_ftruncate(int fd, git_off_t size)
+{
+	if (size < 0) {
+		errno = EINVAL;
+		return -1;
+	}
+
+#if !defined(__MINGW32__) || defined(MINGW_HAS_SECURE_API)
+	return ((_chsize_s(fd, size) == 0) ? 0 : -1);
+#else
+	/* TODO MINGW32 Find a replacement for _chsize() that handles big files. */
+	if (size > INT32_MAX) {
+		errno = EFBIG;
+		return -1;
+	}
+	return _chsize(fd, (long)size);
+#endif
+}
+
+int p_mkdir(const char *path, mode_t mode)
+{
+	git_win32_path buf;
+
+	GIT_UNUSED(mode);
+
+	if (git_win32_path_from_utf8(buf, path) < 0)
+		return -1;
+
+	return _wmkdir(buf);
+}
+
+int p_link(const char *old, const char *new)
+{
+	GIT_UNUSED(old);
+	GIT_UNUSED(new);
+	errno = ENOSYS;
+	return -1;
+}
+
+GIT_INLINE(int) unlink_once(const wchar_t *path)
+{
+	if (DeleteFileW(path))
+		return 0;
+
+	if (last_error_retryable())
+		return GIT_RETRY;
+
+	set_errno();
+	return -1;
+}
+
+int p_unlink(const char *path)
+{
+	git_win32_path wpath;
+
+	if (git_win32_path_from_utf8(wpath, path) < 0)
+		return -1;
+
+	do_with_retries(unlink_once(wpath), ensure_writable(wpath));
+}
+
+int p_fsync(int fd)
+{
+	HANDLE fh = (HANDLE)_get_osfhandle(fd);
+
+	p_fsync__cnt++;
+
+	if (fh == INVALID_HANDLE_VALUE) {
+		errno = EBADF;
+		return -1;
+	}
+
+	if (!FlushFileBuffers(fh)) {
+		DWORD code = GetLastError();
+
+		if (code == ERROR_INVALID_HANDLE)
+			errno = EINVAL;
+		else
+			errno = EIO;
+
+		return -1;
+	}
+
+	return 0;
+}
+
+#define WIN32_IS_WSEP(CH) ((CH) == L'/' || (CH) == L'\\')
+
+static int lstat_w(
+	wchar_t *path,
+	struct stat *buf,
+	bool posix_enotdir)
+{
+	WIN32_FILE_ATTRIBUTE_DATA fdata;
+
+	if (GetFileAttributesExW(path, GetFileExInfoStandard, &fdata)) {
+		if (!buf)
+			return 0;
+
+		return git_win32__file_attribute_to_stat(buf, &fdata, path);
+	}
+
+	switch (GetLastError()) {
+	case ERROR_ACCESS_DENIED:
+		errno = EACCES;
+		break;
+	default:
+		errno = ENOENT;
+		break;
+	}
+
+	/* To match POSIX behavior, set ENOTDIR when any of the folders in the
+	 * file path is a regular file, otherwise set ENOENT.
+	 */
+	if (errno == ENOENT && posix_enotdir) {
+		size_t path_len = wcslen(path);
+
+		/* scan up path until we find an existing item */
+		while (1) {
+			DWORD attrs;
+
+			/* remove last directory component */
+			for (path_len--; path_len > 0 && !WIN32_IS_WSEP(path[path_len]); path_len--);
+
+			if (path_len <= 0)
+				break;
+
+			path[path_len] = L'\0';
+			attrs = GetFileAttributesW(path);
+
+			if (attrs != INVALID_FILE_ATTRIBUTES) {
+				if (!(attrs & FILE_ATTRIBUTE_DIRECTORY))
+					errno = ENOTDIR;
+				break;
+			}
+		}
+	}
+
+	return -1;
+}
+
+static int do_lstat(const char *path, struct stat *buf, bool posixly_correct)
+{
+	git_win32_path path_w;
+	int len;
+
+	if ((len = git_win32_path_from_utf8(path_w, path)) < 0)
+		return -1;
+
+	git_win32__path_trim_end(path_w, len);
+
+	return lstat_w(path_w, buf, posixly_correct);
+}
+
+int p_lstat(const char *filename, struct stat *buf)
+{
+	return do_lstat(filename, buf, false);
+}
+
+int p_lstat_posixly(const char *filename, struct stat *buf)
+{
+	return do_lstat(filename, buf, true);
+}
+
+int p_readlink(const char *path, char *buf, size_t bufsiz)
+{
+	git_win32_path path_w, target_w;
+	git_win32_utf8_path target;
+	int len;
+
+	/* readlink(2) does not NULL-terminate the string written
+	 * to the target buffer. Furthermore, the target buffer need
+	 * not be large enough to hold the entire result. A truncated
+	 * result should be written in this case. Since this truncation
+	 * could occur in the middle of the encoding of a code point,
+	 * we need to buffer the result on the stack. */
+
+	if (git_win32_path_from_utf8(path_w, path) < 0 ||
+		git_win32_path_readlink_w(target_w, path_w) < 0 ||
+		(len = git_win32_path_to_utf8(target, target_w)) < 0)
+		return -1;
+
+	bufsiz = min((size_t)len, bufsiz);
+	memcpy(buf, target, bufsiz);
+
+	return (int)bufsiz;
+}
+
+int p_symlink(const char *old, const char *new)
+{
+	/* Real symlinks on NTFS require admin privileges. Until this changes,
+	 * libgit2 just creates a text file with the link target in the contents.
+	 */
+	return git_futils_fake_symlink(old, new);
+}
+
+struct open_opts {
+	DWORD access;
+	DWORD sharing;
+	SECURITY_ATTRIBUTES security;
+	DWORD creation_disposition;
+	DWORD attributes;
+	int osf_flags;
+};
+
+GIT_INLINE(void) open_opts_from_posix(struct open_opts *opts, int flags, mode_t mode)
+{
+	memset(opts, 0, sizeof(struct open_opts));
+
+	switch (flags & (O_WRONLY | O_RDWR)) {
+	case O_WRONLY:
+		opts->access = GENERIC_WRITE;
+		break;
+	case O_RDWR:
+		opts->access = GENERIC_READ | GENERIC_WRITE;
+		break;
+	default:
+		opts->access = GENERIC_READ;
+		break;
+	}
+
+	opts->sharing = (DWORD)git_win32__createfile_sharemode;
+
+	switch (flags & (O_CREAT | O_TRUNC | O_EXCL)) {
+	case O_CREAT | O_EXCL:
+	case O_CREAT | O_TRUNC | O_EXCL:
+		opts->creation_disposition = CREATE_NEW;
+		break;
+	case O_CREAT | O_TRUNC:
+		opts->creation_disposition = CREATE_ALWAYS;
+		break;
+	case O_TRUNC:
+		opts->creation_disposition = TRUNCATE_EXISTING;
+		break;
+	case O_CREAT:
+		opts->creation_disposition = OPEN_ALWAYS;
+		break;
+	default:
+		opts->creation_disposition = OPEN_EXISTING;
+		break;
+	}
+
+	opts->attributes = ((flags & O_CREAT) && !(mode & S_IWRITE)) ?
+		FILE_ATTRIBUTE_READONLY : FILE_ATTRIBUTE_NORMAL;
+	opts->osf_flags = flags & (O_RDONLY | O_APPEND);
+
+	opts->security.nLength = sizeof(SECURITY_ATTRIBUTES);
+	opts->security.lpSecurityDescriptor = NULL;
+	opts->security.bInheritHandle = 0;
+}
+
+GIT_INLINE(int) open_once(
+	const wchar_t *path,
+	struct open_opts *opts)
+{
+	int fd;
+
+	HANDLE handle = CreateFileW(path, opts->access, opts->sharing,
+		&opts->security, opts->creation_disposition, opts->attributes, 0);
+
+	if (handle == INVALID_HANDLE_VALUE) {
+		if (last_error_retryable())
+			return GIT_RETRY;
+
+		set_errno();
+		return -1;
+	}
+
+	if ((fd = _open_osfhandle((intptr_t)handle, opts->osf_flags)) < 0)
+		CloseHandle(handle);
+
+	return fd;
+}
+
+int p_open(const char *path, int flags, ...)
+{
+	git_win32_path wpath;
+	mode_t mode = 0;
+	struct open_opts opts = {0};
+
+	if (git_win32_path_from_utf8(wpath, path) < 0)
+		return -1;
+
+	if (flags & O_CREAT) {
+		va_list arg_list;
+
+		va_start(arg_list, flags);
+		mode = (mode_t)va_arg(arg_list, int);
+		va_end(arg_list);
+	}
+
+	open_opts_from_posix(&opts, flags, mode);
+
+	do_with_retries(
+		open_once(wpath, &opts),
+		0);
+}
+
+int p_creat(const char *path, mode_t mode)
+{
+	return p_open(path, O_WRONLY | O_CREAT | O_TRUNC, mode);
+}
+
+int p_utimes(const char *path, const struct p_timeval times[2])
+{
+	git_win32_path wpath;
+	int fd, error;
+	DWORD attrs_orig, attrs_new = 0;
+	struct open_opts opts = { 0 };
+
+	if (git_win32_path_from_utf8(wpath, path) < 0)
+		return -1;
+
+	attrs_orig = GetFileAttributesW(wpath);
+
+	if (attrs_orig & FILE_ATTRIBUTE_READONLY) {
+		attrs_new = attrs_orig & ~FILE_ATTRIBUTE_READONLY;
+
+		if (!SetFileAttributesW(wpath, attrs_new)) {
+			giterr_set(GITERR_OS, "failed to set attributes");
+			return -1;
+		}
+	}
+
+	open_opts_from_posix(&opts, O_RDWR, 0);
+
+	if ((fd = open_once(wpath, &opts)) < 0) {
+		error = -1;
+		goto done;
+	}
+
+	error = p_futimes(fd, times);
+	close(fd);
+
+done:
+	if (attrs_orig != attrs_new) {
+		DWORD os_error = GetLastError();
+		SetFileAttributesW(wpath, attrs_orig);
+		SetLastError(os_error);
+	}
+
+	return error;
+}
+
+int p_futimes(int fd, const struct p_timeval times[2])
+{
+	HANDLE handle;
+	FILETIME atime = { 0 }, mtime = { 0 };
+
+	if (times == NULL) {
+		SYSTEMTIME st;
+
+		GetSystemTime(&st);
+		SystemTimeToFileTime(&st, &atime);
+		SystemTimeToFileTime(&st, &mtime);
+	}
+	else {
+		git_win32__timeval_to_filetime(&atime, times[0]);
+		git_win32__timeval_to_filetime(&mtime, times[1]);
+	}
+
+	if ((handle = (HANDLE)_get_osfhandle(fd)) == INVALID_HANDLE_VALUE)
+		return -1;
+
+	if (SetFileTime(handle, NULL, &atime, &mtime) == 0)
+		return -1;
+
+	return 0;
+}
+
+int p_getcwd(char *buffer_out, size_t size)
+{
+	git_win32_path buf;
+	wchar_t *cwd = _wgetcwd(buf, GIT_WIN_PATH_UTF16);
+
+	if (!cwd)
+		return -1;
+
+	/* Convert the working directory back to UTF-8 */
+	if (git__utf16_to_8(buffer_out, size, cwd) < 0) {
+		DWORD code = GetLastError();
+
+		if (code == ERROR_INSUFFICIENT_BUFFER)
+			errno = ERANGE;
+		else
+			errno = EINVAL;
+
+		return -1;
+	}
+
+	return 0;
+}
+
+/*
+ * Returns the address of the GetFinalPathNameByHandleW function.
+ * This function is available on Windows Vista and higher.
+ */
+static PFGetFinalPathNameByHandleW get_fpnbyhandle(void)
+{
+	static PFGetFinalPathNameByHandleW pFunc = NULL;
+	PFGetFinalPathNameByHandleW toReturn = pFunc;
+
+	if (!toReturn) {
+		HMODULE hModule = GetModuleHandleW(L"kernel32");
+
+		if (hModule)
+			toReturn = (PFGetFinalPathNameByHandleW)GetProcAddress(hModule, "GetFinalPathNameByHandleW");
+
+		pFunc = toReturn;
+	}
+
+	assert(toReturn);
+
+	return toReturn;
+}
+
+static int getfinalpath_w(
+	git_win32_path dest,
+	const wchar_t *path)
+{
+	PFGetFinalPathNameByHandleW pgfp = get_fpnbyhandle();
+	HANDLE hFile;
+	DWORD dwChars;
+
+	if (!pgfp)
+		return -1;
+
+	/* Use FILE_FLAG_BACKUP_SEMANTICS so we can open a directory. Do not
+	* specify FILE_FLAG_OPEN_REPARSE_POINT; we want to open a handle to the
+	* target of the link. */
+	hFile = CreateFileW(path, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_DELETE,
+		NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL);
+
+	if (INVALID_HANDLE_VALUE == hFile)
+		return -1;
+
+	/* Call GetFinalPathNameByHandle */
+	dwChars = pgfp(hFile, dest, GIT_WIN_PATH_UTF16, FILE_NAME_NORMALIZED);
+	CloseHandle(hFile);
+
+	if (!dwChars || dwChars >= GIT_WIN_PATH_UTF16)
+		return -1;
+
+	/* The path may be delivered to us with a prefix; canonicalize */
+	return (int)git_win32__canonicalize_path(dest, dwChars);
+}
+
+static int follow_and_lstat_link(git_win32_path path, struct stat* buf)
+{
+	git_win32_path target_w;
+
+	if (getfinalpath_w(target_w, path) < 0)
+		return -1;
+
+	return lstat_w(target_w, buf, false);
+}
+
+int p_fstat(int fd, struct stat *buf)
+{
+	BY_HANDLE_FILE_INFORMATION fhInfo;
+
+	HANDLE fh = (HANDLE)_get_osfhandle(fd);
+
+	if (fh == INVALID_HANDLE_VALUE ||
+		!GetFileInformationByHandle(fh, &fhInfo)) {
+		errno = EBADF;
+		return -1;
+	}
+
+	git_win32__file_information_to_stat(buf, &fhInfo);
+	return 0;
+}
+
+int p_stat(const char* path, struct stat* buf)
+{
+	git_win32_path path_w;
+	int len;
+
+	if ((len = git_win32_path_from_utf8(path_w, path)) < 0 ||
+		lstat_w(path_w, buf, false) < 0)
+		return -1;
+
+	/* The item is a symbolic link or mount point. No need to iterate
+	 * to follow multiple links; use GetFinalPathNameFromHandle. */
+	if (S_ISLNK(buf->st_mode))
+		return follow_and_lstat_link(path_w, buf);
+
+	return 0;
+}
+
+int p_chdir(const char* path)
+{
+	git_win32_path buf;
+
+	if (git_win32_path_from_utf8(buf, path) < 0)
+		return -1;
+
+	return _wchdir(buf);
+}
+
+int p_chmod(const char* path, mode_t mode)
+{
+	git_win32_path buf;
+
+	if (git_win32_path_from_utf8(buf, path) < 0)
+		return -1;
+
+	return _wchmod(buf, mode);
+}
+
+int p_rmdir(const char* path)
+{
+	git_win32_path buf;
+	int error;
+
+	if (git_win32_path_from_utf8(buf, path) < 0)
+		return -1;
+
+	error = _wrmdir(buf);
+
+	if (error == -1) {
+		switch (GetLastError()) {
+			/* _wrmdir() is documented to return EACCES if "A program has an open
+			 * handle to the directory."  This sounds like what everybody else calls
+			 * EBUSY.  Let's convert appropriate error codes.
+			 */
+			case ERROR_SHARING_VIOLATION:
+				errno = EBUSY;
+				break;
+
+			/* This error can be returned when trying to rmdir an extant file. */
+			case ERROR_DIRECTORY:
+				errno = ENOTDIR;
+				break;
+		}
+	}
+
+	return error;
+}
+
+char *p_realpath(const char *orig_path, char *buffer)
+{
+	git_win32_path orig_path_w, buffer_w;
+
+	if (git_win32_path_from_utf8(orig_path_w, orig_path) < 0)
+		return NULL;
+
+	/* Note that if the path provided is a relative path, then the current directory
+	 * is used to resolve the path -- which is a concurrency issue because the current
+	 * directory is a process-wide variable. */
+	if (!GetFullPathNameW(orig_path_w, GIT_WIN_PATH_UTF16, buffer_w, NULL)) {
+		if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)
+			errno = ENAMETOOLONG;
+		else
+			errno = EINVAL;
+
+		return NULL;
+	}
+
+	/* The path must exist. */
+	if (GetFileAttributesW(buffer_w) == INVALID_FILE_ATTRIBUTES) {
+		errno = ENOENT;
+		return NULL;
+	}
+
+	if (!buffer && !(buffer = git__malloc(GIT_WIN_PATH_UTF8))) {
+		errno = ENOMEM;
+		return NULL;
+	}
+
+	/* Convert the path to UTF-8. If the caller provided a buffer, then it
+	 * is assumed to be GIT_WIN_PATH_UTF8 characters in size. If it isn't,
+	 * then we may overflow. */
+	if (git_win32_path_to_utf8(buffer, buffer_w) < 0)
+		return NULL;
+
+	git_path_mkposix(buffer);
+
+	return buffer;
+}
+
+int p_vsnprintf(char *buffer, size_t count, const char *format, va_list argptr)
+{
+#if defined(_MSC_VER)
+	int len;
+
+	if (count == 0)
+		return _vscprintf(format, argptr);
+
+	#if _MSC_VER >= 1500
+	len = _vsnprintf_s(buffer, count, _TRUNCATE, format, argptr);
+	#else
+	len = _vsnprintf(buffer, count, format, argptr);
+	#endif
+
+	if (len < 0)
+		return _vscprintf(format, argptr);
+
+	return len;
+#else /* MinGW */
+	return vsnprintf(buffer, count, format, argptr);
+#endif
+}
+
+int p_snprintf(char *buffer, size_t count, const char *format, ...)
+{
+	va_list va;
+	int r;
+
+	va_start(va, format);
+	r = p_vsnprintf(buffer, count, format, va);
+	va_end(va);
+
+	return r;
+}
+
+/* TODO: wut? */
+int p_mkstemp(char *tmp_path)
+{
+#if defined(_MSC_VER) && _MSC_VER >= 1500
+	if (_mktemp_s(tmp_path, strlen(tmp_path) + 1) != 0)
+		return -1;
+#else
+	if (_mktemp(tmp_path) == NULL)
+		return -1;
+#endif
+
+	return p_open(tmp_path, O_RDWR | O_CREAT | O_EXCL, 0744); //-V536
+}
+
+int p_access(const char* path, mode_t mode)
+{
+	git_win32_path buf;
+
+	if (git_win32_path_from_utf8(buf, path) < 0)
+		return -1;
+
+	return _waccess(buf, mode & WIN32_MODE_MASK);
+}
+
+GIT_INLINE(int) rename_once(const wchar_t *from, const wchar_t *to)
+{
+	if (MoveFileExW(from, to, MOVEFILE_REPLACE_EXISTING | MOVEFILE_COPY_ALLOWED))
+		return 0;
+
+	if (last_error_retryable())
+		return GIT_RETRY;
+
+	set_errno();
+	return -1;
+}
+
+int p_rename(const char *from, const char *to)
+{
+	git_win32_path wfrom, wto;
+
+	if (git_win32_path_from_utf8(wfrom, from) < 0 ||
+		git_win32_path_from_utf8(wto, to) < 0)
+		return -1;
+
+	do_with_retries(rename_once(wfrom, wto), ensure_writable(wto));
+}
+
+int p_recv(GIT_SOCKET socket, void *buffer, size_t length, int flags)
+{
+	if ((size_t)((int)length) != length)
+		return -1; /* giterr_set will be done by caller */
+
+	return recv(socket, buffer, (int)length, flags);
+}
+
+int p_send(GIT_SOCKET socket, const void *buffer, size_t length, int flags)
+{
+	if ((size_t)((int)length) != length)
+		return -1; /* giterr_set will be done by caller */
+
+	return send(socket, buffer, (int)length, flags);
+}
+
+/**
+ * Borrowed from http://old.nabble.com/Porting-localtime_r-and-gmtime_r-td15282276.html
+ * On Win32, `gmtime_r` doesn't exist but `gmtime` is threadsafe, so we can use that
+ */
+struct tm *
+p_localtime_r (const time_t *timer, struct tm *result)
+{
+	struct tm *local_result;
+	local_result = localtime (timer);
+
+	if (local_result == NULL || result == NULL)
+		return NULL;
+
+	memcpy (result, local_result, sizeof (struct tm));
+	return result;
+}
+struct tm *
+p_gmtime_r (const time_t *timer, struct tm *result)
+{
+	struct tm *local_result;
+	local_result = gmtime (timer);
+
+	if (local_result == NULL || result == NULL)
+		return NULL;
+
+	memcpy (result, local_result, sizeof (struct tm));
+	return result;
+}
+
+int p_inet_pton(int af, const char *src, void *dst)
+{
+	struct sockaddr_storage sin;
+	void *addr;
+	int sin_len = sizeof(struct sockaddr_storage), addr_len;
+	int error = 0;
+
+	if (af == AF_INET) {
+		addr = &((struct sockaddr_in *)&sin)->sin_addr;
+		addr_len = sizeof(struct in_addr);
+	} else if (af == AF_INET6) {
+		addr = &((struct sockaddr_in6 *)&sin)->sin6_addr;
+		addr_len = sizeof(struct in6_addr);
+	} else {
+		errno = EAFNOSUPPORT;
+		return -1;
+	}
+
+	if ((error = WSAStringToAddressA((LPSTR)src, af, NULL, (LPSOCKADDR)&sin, &sin_len)) == 0) {
+		memcpy(dst, addr, addr_len);
+		return 1;
+	}
+
+	switch(WSAGetLastError()) {
+	case WSAEINVAL:
+		return 0;
+	case WSAEFAULT:
+		errno = ENOSPC;
+		return -1;
+	case WSA_NOT_ENOUGH_MEMORY:
+		errno = ENOMEM;
+		return -1;
+	}
+
+	errno = EINVAL;
+	return -1;
+}

vendor/libgit2-sys/libgit2/src/win32/precompiled.c

diff --git a/vendor/libgit2-sys/libgit2/src/win32/precompiled.c b/vendor/libgit2-sys/libgit2/src/win32/precompiled.c
new file mode 100644
index 0000000..5f656a4
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/precompiled.c
@@ -0,0 +1 @@
+#include "precompiled.h"

vendor/libgit2-sys/libgit2/src/win32/precompiled.h

diff --git a/vendor/libgit2-sys/libgit2/src/win32/precompiled.h b/vendor/libgit2-sys/libgit2/src/win32/precompiled.h
new file mode 100644
index 0000000..851a083
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/precompiled.h
@@ -0,0 +1,24 @@
+#include "common.h"
+
+#include <assert.h>
+#include <errno.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <time.h>
+#include <stdarg.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <regex.h>
+
+#include <io.h>
+#include <direct.h>
+#ifdef GIT_THREADS
+ #include "win32/thread.h"
+#endif
+
+#include "git2.h"

vendor/libgit2-sys/libgit2/src/win32/reparse.h

diff --git a/vendor/libgit2-sys/libgit2/src/win32/reparse.h b/vendor/libgit2-sys/libgit2/src/win32/reparse.h
new file mode 100644
index 0000000..5f7408a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/reparse.h
@@ -0,0 +1,57 @@
+/*
+* Copyright (C) the libgit2 contributors. All rights reserved.
+*
+* This file is part of libgit2, distributed under the GNU GPL v2 with
+* a Linking Exception. For full terms see the included COPYING file.
+*/
+
+#ifndef INCLUDE_win32_reparse_h__
+#define INCLUDE_win32_reparse_h__
+
+/* This structure is defined on MSDN at
+* http://msdn.microsoft.com/en-us/library/windows/hardware/ff552012(v=vs.85).aspx
+*
+* It was formerly included in the Windows 2000 SDK and remains defined in
+* MinGW, so we must define it with a silly name to avoid conflicting.
+*/
+typedef struct _GIT_REPARSE_DATA_BUFFER {
+	ULONG  ReparseTag;
+	USHORT ReparseDataLength;
+	USHORT Reserved;
+	union {
+		struct {
+			USHORT SubstituteNameOffset;
+			USHORT SubstituteNameLength;
+			USHORT PrintNameOffset;
+			USHORT PrintNameLength;
+			ULONG  Flags;
+			WCHAR  PathBuffer[1];
+		} SymbolicLinkReparseBuffer;
+		struct {
+			USHORT SubstituteNameOffset;
+			USHORT SubstituteNameLength;
+			USHORT PrintNameOffset;
+			USHORT PrintNameLength;
+			WCHAR  PathBuffer[1];
+		} MountPointReparseBuffer;
+		struct {
+			UCHAR DataBuffer[1];
+		} GenericReparseBuffer;
+	};
+} GIT_REPARSE_DATA_BUFFER;
+
+#define REPARSE_DATA_HEADER_SIZE			8
+#define REPARSE_DATA_MOUNTPOINT_HEADER_SIZE	8
+#define REPARSE_DATA_UNION_SIZE				12
+
+/* Missing in MinGW */
+#ifndef FSCTL_GET_REPARSE_POINT
+# define FSCTL_GET_REPARSE_POINT			0x000900a8
+#endif
+
+/* Missing in MinGW */
+#ifndef FSCTL_SET_REPARSE_POINT
+# define FSCTL_SET_REPARSE_POINT			0x000900a4
+#endif
+
+#endif

vendor/libgit2-sys/libgit2/src/win32/thread.c

diff --git a/vendor/libgit2-sys/libgit2/src/win32/thread.c b/vendor/libgit2-sys/libgit2/src/win32/thread.c
new file mode 100644
index 0000000..2d96005
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/thread.c
@@ -0,0 +1,258 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "thread.h"
+
+#include "../global.h"
+
+#define CLEAN_THREAD_EXIT 0x6F012842
+
+typedef void (WINAPI *win32_srwlock_fn)(GIT_SRWLOCK *);
+
+static win32_srwlock_fn win32_srwlock_initialize;
+static win32_srwlock_fn win32_srwlock_acquire_shared;
+static win32_srwlock_fn win32_srwlock_release_shared;
+static win32_srwlock_fn win32_srwlock_acquire_exclusive;
+static win32_srwlock_fn win32_srwlock_release_exclusive;
+
+/* The thread procedure stub used to invoke the caller's procedure
+ * and capture the return value for later collection. Windows will
+ * only hold a DWORD, but we need to be able to store an entire
+ * void pointer. This requires the indirection. */
+static DWORD WINAPI git_win32__threadproc(LPVOID lpParameter)
+{
+	git_thread *thread = lpParameter;
+
+	/* Set the current thread for `git_thread_exit` */
+	GIT_GLOBAL->current_thread = thread;
+
+	thread->result = thread->proc(thread->param);
+
+	git__free_tls_data();
+
+	return CLEAN_THREAD_EXIT;
+}
+
+int git_threads_init(void)
+{
+	HMODULE hModule = GetModuleHandleW(L"kernel32");
+
+	if (hModule) {
+		win32_srwlock_initialize = (win32_srwlock_fn)
+			GetProcAddress(hModule, "InitializeSRWLock");
+		win32_srwlock_acquire_shared = (win32_srwlock_fn)
+			GetProcAddress(hModule, "AcquireSRWLockShared");
+		win32_srwlock_release_shared = (win32_srwlock_fn)
+			GetProcAddress(hModule, "ReleaseSRWLockShared");
+		win32_srwlock_acquire_exclusive = (win32_srwlock_fn)
+			GetProcAddress(hModule, "AcquireSRWLockExclusive");
+		win32_srwlock_release_exclusive = (win32_srwlock_fn)
+			GetProcAddress(hModule, "ReleaseSRWLockExclusive");
+	}
+
+	return 0;
+}
+
+int git_thread_create(
+	git_thread *GIT_RESTRICT thread,
+	void *(*start_routine)(void*),
+	void *GIT_RESTRICT arg)
+{
+	thread->result = NULL;
+	thread->param = arg;
+	thread->proc = start_routine;
+	thread->thread = CreateThread(
+		NULL, 0, git_win32__threadproc, thread, 0, NULL);
+
+	return thread->thread ? 0 : -1;
+}
+
+int git_thread_join(
+	git_thread *thread,
+	void **value_ptr)
+{
+	DWORD exit;
+
+	if (WaitForSingleObject(thread->thread, INFINITE) != WAIT_OBJECT_0)
+		return -1;
+
+	if (!GetExitCodeThread(thread->thread, &exit)) {
+		CloseHandle(thread->thread);
+		return -1;
+	}
+
+	/* Check for the thread having exited uncleanly. If exit was unclean,
+	 * then we don't have a return value to give back to the caller. */
+	if (exit != CLEAN_THREAD_EXIT) {
+		assert(false);
+		thread->result = NULL;
+	}
+
+	if (value_ptr)
+		*value_ptr = thread->result;
+
+	CloseHandle(thread->thread);
+	return 0;
+}
+
+void git_thread_exit(void *value)
+{
+	assert(GIT_GLOBAL->current_thread);
+	GIT_GLOBAL->current_thread->result = value;
+
+	git__free_tls_data();
+
+	ExitThread(CLEAN_THREAD_EXIT);
+}
+
+size_t git_thread_currentid(void)
+{
+	return GetCurrentThreadId();
+}
+
+int git_mutex_init(git_mutex *GIT_RESTRICT mutex)
+{
+	InitializeCriticalSection(mutex);
+	return 0;
+}
+
+int git_mutex_free(git_mutex *mutex)
+{
+	DeleteCriticalSection(mutex);
+	return 0;
+}
+
+int git_mutex_lock(git_mutex *mutex)
+{
+	EnterCriticalSection(mutex);
+	return 0;
+}
+
+int git_mutex_unlock(git_mutex *mutex)
+{
+	LeaveCriticalSection(mutex);
+	return 0;
+}
+
+int git_cond_init(git_cond *cond)
+{
+	/* This is an auto-reset event. */
+	*cond = CreateEventW(NULL, FALSE, FALSE, NULL);
+	assert(*cond);
+
+	/* If we can't create the event, claim that the reason was out-of-memory.
+	 * The actual reason can be fetched with GetLastError(). */
+	return *cond ? 0 : ENOMEM;
+}
+
+int git_cond_free(git_cond *cond)
+{
+	BOOL closed;
+
+	if (!cond)
+		return EINVAL;
+
+	closed = CloseHandle(*cond);
+	assert(closed);
+	GIT_UNUSED(closed);
+
+	*cond = NULL;
+	return 0;
+}
+
+int git_cond_wait(git_cond *cond, git_mutex *mutex)
+{
+	int error;
+	DWORD wait_result;
+
+	if (!cond || !mutex)
+		return EINVAL;
+
+	/* The caller must be holding the mutex. */
+	error = git_mutex_unlock(mutex);
+
+	if (error)
+		return error;
+
+	wait_result = WaitForSingleObject(*cond, INFINITE);
+	assert(WAIT_OBJECT_0 == wait_result);
+	GIT_UNUSED(wait_result);
+
+	return git_mutex_lock(mutex);
+}
+
+int git_cond_signal(git_cond *cond)
+{
+	BOOL signaled;
+
+	if (!cond)
+		return EINVAL;
+
+	signaled = SetEvent(*cond);
+	assert(signaled);
+	GIT_UNUSED(signaled);
+
+	return 0;
+}
+
+int git_rwlock_init(git_rwlock *GIT_RESTRICT lock)
+{
+	if (win32_srwlock_initialize)
+		win32_srwlock_initialize(&lock->native.srwl);
+	else
+		InitializeCriticalSection(&lock->native.csec);
+
+	return 0;
+}
+
+int git_rwlock_rdlock(git_rwlock *lock)
+{
+	if (win32_srwlock_acquire_shared)
+		win32_srwlock_acquire_shared(&lock->native.srwl);
+	else
+		EnterCriticalSection(&lock->native.csec);
+
+	return 0;
+}
+
+int git_rwlock_rdunlock(git_rwlock *lock)
+{
+	if (win32_srwlock_release_shared)
+		win32_srwlock_release_shared(&lock->native.srwl);
+	else
+		LeaveCriticalSection(&lock->native.csec);
+
+	return 0;
+}
+
+int git_rwlock_wrlock(git_rwlock *lock)
+{
+	if (win32_srwlock_acquire_exclusive)
+		win32_srwlock_acquire_exclusive(&lock->native.srwl);
+	else
+		EnterCriticalSection(&lock->native.csec);
+
+	return 0;
+}
+
+int git_rwlock_wrunlock(git_rwlock *lock)
+{
+	if (win32_srwlock_release_exclusive)
+		win32_srwlock_release_exclusive(&lock->native.srwl);
+	else
+		LeaveCriticalSection(&lock->native.csec);
+
+	return 0;
+}
+
+int git_rwlock_free(git_rwlock *lock)
+{
+	if (!win32_srwlock_initialize)
+		DeleteCriticalSection(&lock->native.csec);
+	git__memzero(lock, sizeof(*lock));
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/win32/thread.h

diff --git a/vendor/libgit2-sys/libgit2/src/win32/thread.h b/vendor/libgit2-sys/libgit2/src/win32/thread.h
new file mode 100644
index 0000000..41cbf01
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/thread.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_win32_thread_h__
+#define INCLUDE_win32_thread_h__
+
+#include "common.h"
+
+#if defined (_MSC_VER)
+#	define GIT_RESTRICT __restrict
+#else
+#	define GIT_RESTRICT __restrict__
+#endif
+
+typedef struct {
+	HANDLE thread;
+	void *(*proc)(void *);
+	void *param;
+	void *result;
+} git_thread;
+
+typedef CRITICAL_SECTION git_mutex;
+typedef HANDLE git_cond;
+
+typedef struct { void *Ptr; } GIT_SRWLOCK;
+
+typedef struct {
+	union {
+		GIT_SRWLOCK srwl;
+		CRITICAL_SECTION csec;
+	} native;
+} git_rwlock;
+
+int git_threads_init(void);
+
+int git_thread_create(git_thread *GIT_RESTRICT,
+	void *(*) (void *),
+	void *GIT_RESTRICT);
+int git_thread_join(git_thread *, void **);
+size_t git_thread_currentid(void);
+void git_thread_exit(void *);
+
+int git_mutex_init(git_mutex *GIT_RESTRICT mutex);
+int git_mutex_free(git_mutex *);
+int git_mutex_lock(git_mutex *);
+int git_mutex_unlock(git_mutex *);
+
+int git_cond_init(git_cond *);
+int git_cond_free(git_cond *);
+int git_cond_wait(git_cond *, git_mutex *);
+int git_cond_signal(git_cond *);
+
+int git_rwlock_init(git_rwlock *GIT_RESTRICT lock);
+int git_rwlock_rdlock(git_rwlock *);
+int git_rwlock_rdunlock(git_rwlock *);
+int git_rwlock_wrlock(git_rwlock *);
+int git_rwlock_wrunlock(git_rwlock *);
+int git_rwlock_free(git_rwlock *);
+
+#endif

vendor/libgit2-sys/libgit2/src/win32/utf-conv.c

diff --git a/vendor/libgit2-sys/libgit2/src/win32/utf-conv.c b/vendor/libgit2-sys/libgit2/src/win32/utf-conv.c
new file mode 100644
index 0000000..4bde302
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/utf-conv.c
@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "utf-conv.h"
+
+GIT_INLINE(void) git__set_errno(void)
+{
+	if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)
+		errno = ENAMETOOLONG;
+	else
+		errno = EINVAL;
+}
+
+/**
+ * Converts a UTF-8 string to wide characters.
+ *
+ * @param dest The buffer to receive the wide string.
+ * @param dest_size The size of the buffer, in characters.
+ * @param src The UTF-8 string to convert.
+ * @return The length of the wide string, in characters (not counting the NULL terminator), or < 0 for failure
+ */
+int git__utf8_to_16(wchar_t *dest, size_t dest_size, const char *src)
+{
+	int len;
+
+	/* Length of -1 indicates NULL termination of the input string. Subtract 1 from the result to
+	* turn 0 into -1 (an error code) and to not count the NULL terminator as part of the string's
+	* length. MultiByteToWideChar never returns int's minvalue, so underflow is not possible */
+	if ((len = MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, src, -1, dest, (int)dest_size) - 1) < 0)
+		git__set_errno();
+
+	return len;
+}
+
+/**
+ * Converts a wide string to UTF-8.
+ *
+ * @param dest The buffer to receive the UTF-8 string.
+ * @param dest_size The size of the buffer, in bytes.
+ * @param src The wide string to convert.
+ * @return The length of the UTF-8 string, in bytes (not counting the NULL terminator), or < 0 for failure
+ */
+int git__utf16_to_8(char *dest, size_t dest_size, const wchar_t *src)
+{
+	int len;
+
+	/* Length of -1 indicates NULL termination of the input string. Subtract 1 from the result to
+	 * turn 0 into -1 (an error code) and to not count the NULL terminator as part of the string's
+	 * length. WideCharToMultiByte never returns int's minvalue, so underflow is not possible */
+	if ((len = WideCharToMultiByte(CP_UTF8, WC_ERR_INVALID_CHARS, src, -1, dest, (int)dest_size, NULL, NULL) - 1) < 0)
+		git__set_errno();
+
+	return len;
+}
+
+/**
+ * Converts a UTF-8 string to wide characters.
+ * Memory is allocated to hold the converted string.
+ * The caller is responsible for freeing the string with git__free.
+ *
+ * @param dest Receives a pointer to the wide string.
+ * @param src The UTF-8 string to convert.
+ * @return The length of the wide string, in characters (not counting the NULL terminator), or < 0 for failure
+ */
+int git__utf8_to_16_alloc(wchar_t **dest, const char *src)
+{
+	int utf16_size;
+
+	*dest = NULL;
+
+	/* Length of -1 indicates NULL termination of the input string */
+	utf16_size = MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, src, -1, NULL, 0);
+
+	if (!utf16_size) {
+		git__set_errno();
+		return -1;
+	}
+
+	if (!(*dest = git__mallocarray(utf16_size, sizeof(wchar_t)))) {
+		errno = ENOMEM;
+		return -1;
+	}
+
+	utf16_size = MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, src, -1, *dest, utf16_size);
+
+	if (!utf16_size) {
+		git__set_errno();
+
+		git__free(*dest);
+		*dest = NULL;
+	}
+
+	/* Subtract 1 from the result to turn 0 into -1 (an error code) and to not count the NULL
+	 * terminator as part of the string's length. MultiByteToWideChar never returns int's minvalue,
+	 * so underflow is not possible */
+	return utf16_size - 1;
+}
+
+/**
+ * Converts a wide string to UTF-8.
+ * Memory is allocated to hold the converted string.
+ * The caller is responsible for freeing the string with git__free.
+ *
+ * @param dest Receives a pointer to the UTF-8 string.
+ * @param src The wide string to convert.
+ * @return The length of the UTF-8 string, in bytes (not counting the NULL terminator), or < 0 for failure
+ */
+int git__utf16_to_8_alloc(char **dest, const wchar_t *src)
+{
+	int utf8_size;
+
+	*dest = NULL;
+
+	/* Length of -1 indicates NULL termination of the input string */
+	utf8_size = WideCharToMultiByte(CP_UTF8, WC_ERR_INVALID_CHARS, src, -1, NULL, 0, NULL, NULL);
+
+	if (!utf8_size) {
+		git__set_errno();
+		return -1;
+	}
+
+	*dest = git__malloc(utf8_size);
+
+	if (!*dest) {
+		errno = ENOMEM;
+		return -1;
+	}
+
+	utf8_size = WideCharToMultiByte(CP_UTF8, WC_ERR_INVALID_CHARS, src, -1, *dest, utf8_size, NULL, NULL);
+
+	if (!utf8_size) {
+		git__set_errno();
+
+		git__free(*dest);
+		*dest = NULL;
+	}
+
+	/* Subtract 1 from the result to turn 0 into -1 (an error code) and to not count the NULL
+	 * terminator as part of the string's length. MultiByteToWideChar never returns int's minvalue,
+	 * so underflow is not possible */
+	return utf8_size - 1;
+}

vendor/libgit2-sys/libgit2/src/win32/utf-conv.h

diff --git a/vendor/libgit2-sys/libgit2/src/win32/utf-conv.h b/vendor/libgit2-sys/libgit2/src/win32/utf-conv.h
new file mode 100644
index 0000000..6090a4b
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/utf-conv.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_win32_utf_conv_h__
+#define INCLUDE_win32_utf_conv_h__
+
+#include "common.h"
+
+#include <wchar.h>
+
+#ifndef WC_ERR_INVALID_CHARS
+# define WC_ERR_INVALID_CHARS	0x80
+#endif
+
+/**
+ * Converts a UTF-8 string to wide characters.
+ *
+ * @param dest The buffer to receive the wide string.
+ * @param dest_size The size of the buffer, in characters.
+ * @param src The UTF-8 string to convert.
+ * @return The length of the wide string, in characters (not counting the NULL terminator), or < 0 for failure
+ */
+int git__utf8_to_16(wchar_t *dest, size_t dest_size, const char *src);
+
+/**
+ * Converts a wide string to UTF-8.
+ *
+ * @param dest The buffer to receive the UTF-8 string.
+ * @param dest_size The size of the buffer, in bytes.
+ * @param src The wide string to convert.
+ * @return The length of the UTF-8 string, in bytes (not counting the NULL terminator), or < 0 for failure
+ */
+int git__utf16_to_8(char *dest, size_t dest_size, const wchar_t *src);
+
+/**
+ * Converts a UTF-8 string to wide characters.
+ * Memory is allocated to hold the converted string.
+ * The caller is responsible for freeing the string with git__free.
+ *
+ * @param dest Receives a pointer to the wide string.
+ * @param src The UTF-8 string to convert.
+ * @return The length of the wide string, in characters (not counting the NULL terminator), or < 0 for failure
+ */
+int git__utf8_to_16_alloc(wchar_t **dest, const char *src);
+
+/**
+ * Converts a wide string to UTF-8.
+ * Memory is allocated to hold the converted string.
+ * The caller is responsible for freeing the string with git__free.
+ *
+ * @param dest Receives a pointer to the UTF-8 string.
+ * @param src The wide string to convert.
+ * @return The length of the UTF-8 string, in bytes (not counting the NULL terminator), or < 0 for failure
+ */
+int git__utf16_to_8_alloc(char **dest, const wchar_t *src);
+
+#endif

vendor/libgit2-sys/libgit2/src/win32/version.h

diff --git a/vendor/libgit2-sys/libgit2/src/win32/version.h b/vendor/libgit2-sys/libgit2/src/win32/version.h
new file mode 100644
index 0000000..7966769
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/version.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_win32_version_h__
+#define INCLUDE_win32_version_h__
+
+#include <windows.h>
+
+GIT_INLINE(int) git_has_win32_version(int major, int minor, int service_pack)
+{
+	OSVERSIONINFOEX version_test = {0};
+	DWORD version_test_mask;
+	DWORDLONG version_condition_mask = 0;
+	
+	version_test.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);
+	version_test.dwMajorVersion = major;
+	version_test.dwMinorVersion = minor;
+	version_test.wServicePackMajor = (WORD)service_pack;
+	version_test.wServicePackMinor = 0;
+
+	version_test_mask = (VER_MAJORVERSION | VER_MINORVERSION | VER_SERVICEPACKMAJOR | VER_SERVICEPACKMINOR);
+
+	VER_SET_CONDITION(version_condition_mask, VER_MAJORVERSION, VER_GREATER_EQUAL);
+	VER_SET_CONDITION(version_condition_mask, VER_MINORVERSION, VER_GREATER_EQUAL);
+	VER_SET_CONDITION(version_condition_mask, VER_SERVICEPACKMAJOR, VER_GREATER_EQUAL);
+	VER_SET_CONDITION(version_condition_mask, VER_SERVICEPACKMINOR, VER_GREATER_EQUAL);
+
+	if (!VerifyVersionInfo(&version_test, version_test_mask, version_condition_mask))
+		return 0;
+
+	return 1;
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/win32/w32_buffer.c

diff --git a/vendor/libgit2-sys/libgit2/src/win32/w32_buffer.c b/vendor/libgit2-sys/libgit2/src/win32/w32_buffer.c
new file mode 100644
index 0000000..45c024d
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/w32_buffer.c
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "w32_buffer.h"
+
+#include "../buffer.h"
+#include "utf-conv.h"
+
+GIT_INLINE(int) handle_wc_error(void)
+{
+	if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)
+		errno = ENAMETOOLONG;
+	else
+		errno = EINVAL;
+
+	return -1;
+}
+
+int git_buf_put_w(git_buf *buf, const wchar_t *string_w, size_t len_w)
+{
+	int utf8_len, utf8_write_len;
+	size_t new_size;
+
+	if (!len_w)
+		return 0;
+
+	assert(string_w);
+
+	/* Measure the string necessary for conversion */
+	if ((utf8_len = WideCharToMultiByte(CP_UTF8, WC_ERR_INVALID_CHARS, string_w, len_w, NULL, 0, NULL, NULL)) == 0)
+		return 0;
+
+	assert(utf8_len > 0);
+
+	GITERR_CHECK_ALLOC_ADD(&new_size, buf->size, (size_t)utf8_len);
+	GITERR_CHECK_ALLOC_ADD(&new_size, new_size, 1);
+
+	if (git_buf_grow(buf, new_size) < 0)
+		return -1;
+
+	if ((utf8_write_len = WideCharToMultiByte(
+			CP_UTF8, WC_ERR_INVALID_CHARS, string_w, len_w, &buf->ptr[buf->size], utf8_len, NULL, NULL)) == 0)
+		return handle_wc_error();
+
+	assert(utf8_write_len == utf8_len);
+
+	buf->size += utf8_write_len;
+	buf->ptr[buf->size] = '\0';
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/win32/w32_buffer.h

diff --git a/vendor/libgit2-sys/libgit2/src/win32/w32_buffer.h b/vendor/libgit2-sys/libgit2/src/win32/w32_buffer.h
new file mode 100644
index 0000000..43298e4
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/w32_buffer.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_win32_w32_buffer_h__
+#define INCLUDE_win32_w32_buffer_h__
+
+#include "common.h"
+
+#include "../buffer.h"
+
+/**
+ * Convert a wide character string to UTF-8 and append the results to the
+ * buffer.
+ */
+int git_buf_put_w(git_buf *buf, const wchar_t *string_w, size_t len_w);
+
+#endif

vendor/libgit2-sys/libgit2/src/win32/w32_crtdbg_stacktrace.c

diff --git a/vendor/libgit2-sys/libgit2/src/win32/w32_crtdbg_stacktrace.c b/vendor/libgit2-sys/libgit2/src/win32/w32_crtdbg_stacktrace.c
new file mode 100644
index 0000000..7b3c3fb
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/w32_crtdbg_stacktrace.c
@@ -0,0 +1,344 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "w32_crtdbg_stacktrace.h"
+
+#if defined(GIT_MSVC_CRTDBG)
+#include "w32_stack.h"
+
+#define CRTDBG_STACKTRACE__UID_LEN (15)
+
+/**
+ * The stacktrace of an allocation can be distilled
+ * to a unique id based upon the stackframe pointers
+ * and ignoring any size arguments. We will use these
+ * UIDs as the (char const*) __FILE__ argument we
+ * give to the CRT malloc routines.
+ */
+typedef struct {
+	char uid[CRTDBG_STACKTRACE__UID_LEN + 1];
+} git_win32__crtdbg_stacktrace__uid;
+
+/**
+ * All mallocs with the same stacktrace will be de-duped
+ * and aggregated into this row.
+ */
+typedef struct {
+	git_win32__crtdbg_stacktrace__uid uid; /* must be first */
+	git_win32__stack__raw_data raw_data;
+	unsigned int count_allocs; /* times this alloc signature seen since init */
+	unsigned int count_allocs_at_last_checkpoint; /* times since last mark */
+	unsigned int transient_count_leaks; /* sum of leaks */
+} git_win32__crtdbg_stacktrace__row;
+
+static CRITICAL_SECTION g_crtdbg_stacktrace_cs;
+
+/**
+ * CRTDBG memory leak tracking takes a "char const * const file_name"
+ * and stores the pointer in the heap data (instead of allocing a copy
+ * for itself).  Normally, this is not a problem, since we usually pass
+ * in __FILE__.  But I'm going to lie to it and pass in the address of
+ * the UID in place of the file_name.  Also, I do not want to alloc the
+ * stacktrace data (because we are called from inside our alloc routines).
+ * Therefore, I'm creating a very large static pool array to store row
+ * data. This also eliminates the temptation to realloc it (and move the
+ * UID pointers).
+ *
+ * And to efficiently look for duplicates we need an index on the rows
+ * so we can bsearch it.  Again, without mallocing.
+ *
+ * If we observe more than MY_ROW_LIMIT unique malloc signatures, we
+ * fall through and use the traditional __FILE__ processing and don't
+ * try to de-dup them.  If your testing hits this limit, just increase
+ * it and try again.
+ */
+
+#define MY_ROW_LIMIT (1024 * 1024)
+static git_win32__crtdbg_stacktrace__row  g_cs_rows[MY_ROW_LIMIT];
+static git_win32__crtdbg_stacktrace__row *g_cs_index[MY_ROW_LIMIT];
+
+static unsigned int g_cs_end = MY_ROW_LIMIT;
+static unsigned int g_cs_ins = 0; /* insertion point == unique allocs seen */
+static unsigned int g_count_total_allocs = 0; /* number of allocs seen */
+static unsigned int g_transient_count_total_leaks = 0; /* number of total leaks */
+static unsigned int g_transient_count_dedup_leaks = 0; /* number of unique leaks */
+static bool g_limit_reached = false; /* had allocs after we filled row table */
+
+static unsigned int g_checkpoint_id = 0; /* to better label leak checkpoints */
+static bool g_transient_leaks_since_mark = false; /* payload for hook */
+
+/**
+ * Compare function for bsearch on g_cs_index table.
+ */
+static int row_cmp(const void *v1, const void *v2)
+{
+	git_win32__stack__raw_data *d1 = (git_win32__stack__raw_data*)v1;
+	git_win32__crtdbg_stacktrace__row *r2 = (git_win32__crtdbg_stacktrace__row *)v2;
+
+	return (git_win32__stack_compare(d1, &r2->raw_data));
+}
+
+/**
+ * Unique insert the new data into the row and index tables.
+ * We have to sort by the stackframe data itself, not the uid.
+ */
+static git_win32__crtdbg_stacktrace__row * insert_unique(
+	const git_win32__stack__raw_data *pdata)
+{
+	size_t pos;
+	if (git__bsearch(g_cs_index, g_cs_ins, pdata, row_cmp, &pos) < 0) {
+		/* Append new unique item to row table. */
+		memcpy(&g_cs_rows[g_cs_ins].raw_data, pdata, sizeof(*pdata));
+		sprintf(g_cs_rows[g_cs_ins].uid.uid, "##%08lx", g_cs_ins);
+
+		/* Insert pointer to it into the proper place in the index table. */
+		if (pos < g_cs_ins)
+			memmove(&g_cs_index[pos+1], &g_cs_index[pos], (g_cs_ins - pos)*sizeof(g_cs_index[0]));
+		g_cs_index[pos] = &g_cs_rows[g_cs_ins];
+
+		g_cs_ins++;
+	}
+
+	g_cs_index[pos]->count_allocs++;
+
+	return g_cs_index[pos];
+}
+
+/**
+ * Hook function to receive leak data from the CRT. (This includes
+ * both "<file_name>:(<line_number>)" data, but also each of the
+ * various headers and fields.
+ *
+ * Scan this for the special "##<pos>" UID forms that we substituted
+ * for the "<file_name>".  Map <pos> back to the row data and
+ * increment its leak count.
+ *
+ * See https://msdn.microsoft.com/en-us/library/74kabxyx.aspx
+ *
+ * We suppress the actual crtdbg output.
+ */
+static int __cdecl report_hook(int nRptType, char *szMsg, int *retVal)
+{
+	static int hook_result = TRUE; /* FALSE to get stock dump; TRUE to suppress. */
+	unsigned int pos;
+
+	*retVal = 0; /* do not invoke debugger */
+
+	if ((szMsg[0] != '#') || (szMsg[1] != '#'))
+		return hook_result;
+
+	if (sscanf(&szMsg[2], "%08lx", &pos) < 1)
+		return hook_result;
+	if (pos >= g_cs_ins)
+		return hook_result;
+
+	if (g_transient_leaks_since_mark) {
+		if (g_cs_rows[pos].count_allocs == g_cs_rows[pos].count_allocs_at_last_checkpoint)
+			return hook_result;
+	}
+
+	g_cs_rows[pos].transient_count_leaks++;
+
+	if (g_cs_rows[pos].transient_count_leaks == 1)
+		g_transient_count_dedup_leaks++;
+
+	g_transient_count_total_leaks++;
+
+	return hook_result;
+}
+
+/**
+ * Write leak data to all of the various places we need.
+ * We force the caller to sprintf() the message first
+ * because we want to avoid fprintf() because it allocs.
+ */
+static void my_output(const char *buf)
+{
+	fwrite(buf, strlen(buf), 1, stderr);
+	OutputDebugString(buf);
+}
+
+/**
+ * For each row with leaks, dump a stacktrace for it.
+ */
+static void dump_summary(const char *label)
+{
+	unsigned int k;
+	char buf[10 * 1024];
+
+	if (g_transient_count_total_leaks == 0)
+		return;
+
+	fflush(stdout);
+	fflush(stderr);
+	my_output("\n");
+
+	if (g_limit_reached) {
+		sprintf(buf,
+				"LEAK SUMMARY: de-dup row table[%d] filled. Increase MY_ROW_LIMIT.\n",
+				MY_ROW_LIMIT);
+		my_output(buf);
+	}
+
+	if (!label)
+		label = "";
+
+	if (g_transient_leaks_since_mark) {
+		sprintf(buf, "LEAK CHECKPOINT %d: leaks %d unique %d: %s\n",
+				g_checkpoint_id, g_transient_count_total_leaks, g_transient_count_dedup_leaks, label);
+		my_output(buf);
+	} else {
+		sprintf(buf, "LEAK SUMMARY: TOTAL leaks %d de-duped %d: %s\n",
+				g_transient_count_total_leaks, g_transient_count_dedup_leaks, label);
+		my_output(buf);
+	}
+	my_output("\n");
+
+	for (k = 0; k < g_cs_ins; k++) {
+		if (g_cs_rows[k].transient_count_leaks > 0) {
+			sprintf(buf, "LEAK: %s leaked %d of %d times:\n",
+					g_cs_rows[k].uid.uid,
+					g_cs_rows[k].transient_count_leaks,
+					g_cs_rows[k].count_allocs);
+			my_output(buf);
+
+			if (git_win32__stack_format(
+					buf, sizeof(buf), &g_cs_rows[k].raw_data,
+					NULL, NULL) >= 0) {
+				my_output(buf);
+			}
+
+			my_output("\n");
+		}
+	}
+
+	fflush(stderr);
+}
+
+void git_win32__crtdbg_stacktrace_init(void)
+{
+	InitializeCriticalSection(&g_crtdbg_stacktrace_cs);
+
+	EnterCriticalSection(&g_crtdbg_stacktrace_cs);
+
+	_CrtSetDbgFlag(_CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF);
+
+	_CrtSetReportMode(_CRT_ASSERT, _CRTDBG_MODE_DEBUG | _CRTDBG_MODE_FILE);
+	_CrtSetReportMode(_CRT_ERROR,  _CRTDBG_MODE_DEBUG | _CRTDBG_MODE_FILE);
+	_CrtSetReportMode(_CRT_WARN,   _CRTDBG_MODE_DEBUG | _CRTDBG_MODE_FILE);
+
+	_CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDERR);
+	_CrtSetReportFile(_CRT_ERROR,  _CRTDBG_FILE_STDERR);
+	_CrtSetReportFile(_CRT_WARN,   _CRTDBG_FILE_STDERR);
+
+	LeaveCriticalSection(&g_crtdbg_stacktrace_cs);
+}
+
+int git_win32__crtdbg_stacktrace__dump(
+	git_win32__crtdbg_stacktrace_options opt,
+	const char *label)
+{
+	_CRT_REPORT_HOOK old;
+	unsigned int k;
+	int r = 0;
+
+#define IS_BIT_SET(o,b) (((o) & (b)) != 0)
+
+	bool b_set_mark         = IS_BIT_SET(opt, GIT_WIN32__CRTDBG_STACKTRACE__SET_MARK);
+	bool b_leaks_since_mark = IS_BIT_SET(opt, GIT_WIN32__CRTDBG_STACKTRACE__LEAKS_SINCE_MARK);
+	bool b_leaks_total      = IS_BIT_SET(opt, GIT_WIN32__CRTDBG_STACKTRACE__LEAKS_TOTAL);
+	bool b_quiet            = IS_BIT_SET(opt, GIT_WIN32__CRTDBG_STACKTRACE__QUIET);
+
+	if (b_leaks_since_mark && b_leaks_total) {
+		giterr_set(GITERR_INVALID, "cannot combine LEAKS_SINCE_MARK and LEAKS_TOTAL.");
+		return GIT_ERROR;
+	}
+	if (!b_set_mark && !b_leaks_since_mark && !b_leaks_total) {
+		giterr_set(GITERR_INVALID, "nothing to do.");
+		return GIT_ERROR;
+	}
+
+	EnterCriticalSection(&g_crtdbg_stacktrace_cs);
+
+	if (b_leaks_since_mark || b_leaks_total) {
+		/* All variables with "transient" in the name are per-dump counters
+		 * and reset before each dump.  This lets us handle checkpoints.
+		 */
+		g_transient_count_total_leaks = 0;
+		g_transient_count_dedup_leaks = 0;
+		for (k = 0; k < g_cs_ins; k++) {
+			g_cs_rows[k].transient_count_leaks = 0;
+		}
+	}
+
+	g_transient_leaks_since_mark = b_leaks_since_mark;
+
+	old = _CrtSetReportHook(report_hook);
+	_CrtDumpMemoryLeaks();
+	_CrtSetReportHook(old);
+
+	if (b_leaks_since_mark || b_leaks_total) {
+		r = g_transient_count_dedup_leaks;
+
+		if (!b_quiet)
+			dump_summary(label);
+	}
+
+	if (b_set_mark) {
+		for (k = 0; k < g_cs_ins; k++) {
+			g_cs_rows[k].count_allocs_at_last_checkpoint = g_cs_rows[k].count_allocs;
+		}
+
+		g_checkpoint_id++;
+	}
+
+	LeaveCriticalSection(&g_crtdbg_stacktrace_cs);
+
+	return r;
+}
+
+void git_win32__crtdbg_stacktrace_cleanup(void)
+{
+	/* At shutdown/cleanup, dump cummulative leak info
+	 * with everything since startup.  This might generate
+	 * extra noise if the caller has been doing checkpoint
+	 * dumps, but it might also eliminate some false
+	 * positives for resources previously reported during
+	 * checkpoints.
+	 */
+	git_win32__crtdbg_stacktrace__dump(
+		GIT_WIN32__CRTDBG_STACKTRACE__LEAKS_TOTAL,
+		"CLEANUP");
+
+	DeleteCriticalSection(&g_crtdbg_stacktrace_cs);
+}
+
+const char *git_win32__crtdbg_stacktrace(int skip, const char *file)
+{
+	git_win32__stack__raw_data new_data;
+	git_win32__crtdbg_stacktrace__row *row;
+	const char * result = file;
+
+	if (git_win32__stack_capture(&new_data, skip+1) < 0)
+		return result;
+
+	EnterCriticalSection(&g_crtdbg_stacktrace_cs);
+
+	if (g_cs_ins < g_cs_end) {
+		row = insert_unique(&new_data);
+		result = row->uid.uid;
+	} else {
+		g_limit_reached = true;
+	}
+
+	g_count_total_allocs++;
+
+	LeaveCriticalSection(&g_crtdbg_stacktrace_cs);
+
+	return result;
+}
+#endif

vendor/libgit2-sys/libgit2/src/win32/w32_crtdbg_stacktrace.h

diff --git a/vendor/libgit2-sys/libgit2/src/win32/w32_crtdbg_stacktrace.h b/vendor/libgit2-sys/libgit2/src/win32/w32_crtdbg_stacktrace.h
new file mode 100644
index 0000000..3f58035
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/w32_crtdbg_stacktrace.h
@@ -0,0 +1,176 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_win32_w32_crtdbg_stacktrace_h__
+#define INCLUDE_win32_w32_crtdbg_stacktrace_h__
+
+#include "common.h"
+
+#if defined(GIT_MSVC_CRTDBG)
+
+#include <stdlib.h>
+#include <crtdbg.h>
+
+#include "git2/errors.h"
+#include "strnlen.h"
+
+/**
+ * Initialize our memory leak tracking and de-dup data structures.
+ * This should ONLY be called by git_libgit2_init().
+ */
+void git_win32__crtdbg_stacktrace_init(void);
+
+/**
+ * Shutdown our memory leak tracking and dump summary data.
+ * This should ONLY be called by git_libgit2_shutdown().
+ *
+ * We explicitly call _CrtDumpMemoryLeaks() during here so
+ * that we can compute summary data for the leaks. We print
+ * the stacktrace of each unique leak.
+ *
+ * This cleanup does not happen if the app calls exit()
+ * without calling the libgit2 shutdown code.
+ *
+ * This info we print here is independent of any automatic
+ * reporting during exit() caused by _CRTDBG_LEAK_CHECK_DF.
+ * Set it in your app if you also want traditional reporting.
+ */
+void git_win32__crtdbg_stacktrace_cleanup(void);
+
+/**
+ * Checkpoint options.
+ */
+typedef enum git_win32__crtdbg_stacktrace_options {
+	/**
+	 * Set checkpoint marker.
+	 */
+	GIT_WIN32__CRTDBG_STACKTRACE__SET_MARK         = (1 << 0),
+
+	/**
+	 * Dump leaks since last checkpoint marker.
+	 * May not be combined with __LEAKS_TOTAL.
+	 *
+	 * Note that this may generate false positives for global TLS
+	 * error state and other global caches that aren't cleaned up
+	 * until the thread/process terminates.  So when using this
+	 * around a region of interest, also check the final (at exit)
+	 * dump before digging into leaks reported here.
+	 */
+	GIT_WIN32__CRTDBG_STACKTRACE__LEAKS_SINCE_MARK = (1 << 1),
+
+	/**
+	 * Dump leaks since init.  May not be combined
+	 * with __LEAKS_SINCE_MARK.
+	 */
+	GIT_WIN32__CRTDBG_STACKTRACE__LEAKS_TOTAL      = (1 << 2),
+
+	/**
+	 * Suppress printing during dumps.
+	 * Just return leak count.
+	 */
+	GIT_WIN32__CRTDBG_STACKTRACE__QUIET            = (1 << 3),
+
+} git_win32__crtdbg_stacktrace_options;
+
+/**
+ * Checkpoint memory state and/or dump unique stack traces of
+ * current memory leaks.
+ *
+ * @return number of unique leaks (relative to requested starting
+ * point) or error.
+ */
+GIT_EXTERN(int) git_win32__crtdbg_stacktrace__dump(
+	git_win32__crtdbg_stacktrace_options opt,
+	const char *label);
+
+/**
+ * Construct stacktrace and append it to the global buffer.
+ * Return pointer to start of this string.  On any error or
+ * lack of buffer space, just return the given file buffer
+ * so it will behave as usual.
+ *
+ * This should ONLY be called by our internal memory allocations
+ * routines.
+ */
+const char *git_win32__crtdbg_stacktrace(int skip, const char *file);
+
+GIT_INLINE(void *) git__crtdbg__malloc(size_t len, const char *file, int line)
+{
+	void *ptr = _malloc_dbg(len, _NORMAL_BLOCK, git_win32__crtdbg_stacktrace(1,file), line);
+	if (!ptr) giterr_set_oom();
+	return ptr;
+}
+
+GIT_INLINE(void *) git__crtdbg__calloc(size_t nelem, size_t elsize, const char *file, int line)
+{
+	void *ptr = _calloc_dbg(nelem, elsize, _NORMAL_BLOCK, git_win32__crtdbg_stacktrace(1,file), line);
+	if (!ptr) giterr_set_oom();
+	return ptr;
+}
+
+GIT_INLINE(char *) git__crtdbg__strdup(const char *str, const char *file, int line)
+{
+	char *ptr = _strdup_dbg(str, _NORMAL_BLOCK, git_win32__crtdbg_stacktrace(1,file), line);
+	if (!ptr) giterr_set_oom();
+	return ptr;
+}
+
+GIT_INLINE(char *) git__crtdbg__strndup(const char *str, size_t n, const char *file, int line)
+{
+	size_t length = 0, alloclength;
+	char *ptr;
+
+	length = p_strnlen(str, n);
+
+	if (GIT_ADD_SIZET_OVERFLOW(&alloclength, length, 1) ||
+		!(ptr = git__crtdbg__malloc(alloclength, file, line)))
+		return NULL;
+
+	if (length)
+		memcpy(ptr, str, length);
+
+	ptr[length] = '\0';
+
+	return ptr;
+}
+
+GIT_INLINE(char *) git__crtdbg__substrdup(const char *start, size_t n, const char *file, int line)
+{
+	char *ptr;
+	size_t alloclen;
+
+	if (GIT_ADD_SIZET_OVERFLOW(&alloclen, n, 1) ||
+		!(ptr = git__crtdbg__malloc(alloclen, file, line)))
+		return NULL;
+
+	memcpy(ptr, start, n);
+	ptr[n] = '\0';
+	return ptr;
+}
+
+GIT_INLINE(void *) git__crtdbg__realloc(void *ptr, size_t size, const char *file, int line)
+{
+	void *new_ptr = _realloc_dbg(ptr, size, _NORMAL_BLOCK, git_win32__crtdbg_stacktrace(1,file), line);
+	if (!new_ptr) giterr_set_oom();
+	return new_ptr;
+}
+
+GIT_INLINE(void *) git__crtdbg__reallocarray(void *ptr, size_t nelem, size_t elsize, const char *file, int line)
+{
+	size_t newsize;
+
+	return GIT_MULTIPLY_SIZET_OVERFLOW(&newsize, nelem, elsize) ?
+		NULL : _realloc_dbg(ptr, newsize, _NORMAL_BLOCK, git_win32__crtdbg_stacktrace(1,file), line);
+}
+
+GIT_INLINE(void *) git__crtdbg__mallocarray(size_t nelem, size_t elsize, const char *file, int line)
+{
+	return git__crtdbg__reallocarray(NULL, nelem, elsize, file, line);
+}
+
+
+#endif
+#endif

vendor/libgit2-sys/libgit2/src/win32/w32_stack.c

diff --git a/vendor/libgit2-sys/libgit2/src/win32/w32_stack.c b/vendor/libgit2-sys/libgit2/src/win32/w32_stack.c
new file mode 100644
index 0000000..b40f9d2
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/w32_stack.c
@@ -0,0 +1,193 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "w32_stack.h"
+
+#if defined(GIT_MSVC_CRTDBG)
+#include "Windows.h"
+#include "Dbghelp.h"
+#include "win32/posix.h"
+#include "hash.h"
+
+/**
+ * This is supposedly defined in WinBase.h (from Windows.h) but there were linker issues.
+ */
+USHORT WINAPI RtlCaptureStackBackTrace(ULONG, ULONG, PVOID*, PULONG);
+
+static bool   g_win32_stack_initialized = false;
+static HANDLE g_win32_stack_process = INVALID_HANDLE_VALUE;
+static git_win32__stack__aux_cb_alloc  g_aux_cb_alloc  = NULL;
+static git_win32__stack__aux_cb_lookup g_aux_cb_lookup = NULL;
+
+int git_win32__stack__set_aux_cb(
+	git_win32__stack__aux_cb_alloc cb_alloc,
+	git_win32__stack__aux_cb_lookup cb_lookup)
+{
+	g_aux_cb_alloc = cb_alloc;
+	g_aux_cb_lookup = cb_lookup;
+
+	return 0;
+}
+
+void git_win32__stack_init(void)
+{
+	if (!g_win32_stack_initialized) {
+		g_win32_stack_process = GetCurrentProcess();
+		SymSetOptions(SYMOPT_LOAD_LINES);
+		SymInitialize(g_win32_stack_process, NULL, TRUE);
+		g_win32_stack_initialized = true;
+	}
+}
+
+void git_win32__stack_cleanup(void)
+{
+	if (g_win32_stack_initialized) {
+		SymCleanup(g_win32_stack_process);
+		g_win32_stack_process = INVALID_HANDLE_VALUE;
+		g_win32_stack_initialized = false;
+	}
+}
+
+int git_win32__stack_capture(git_win32__stack__raw_data *pdata, int skip)
+{
+	if (!g_win32_stack_initialized) {
+		giterr_set(GITERR_INVALID, "git_win32_stack not initialized.");
+		return GIT_ERROR;
+	}
+
+	memset(pdata, 0, sizeof(*pdata));
+	pdata->nr_frames = RtlCaptureStackBackTrace(
+		skip+1, GIT_WIN32__STACK__MAX_FRAMES, pdata->frames, NULL);
+
+	/* If an "aux" data provider was registered, ask it to capture
+	 * whatever data it needs and give us an "aux_id" to it so that
+	 * we can refer to it later when reporting.
+	 */
+	if (g_aux_cb_alloc)
+		(g_aux_cb_alloc)(&pdata->aux_id);
+
+	return 0;
+}
+
+int git_win32__stack_compare(
+	git_win32__stack__raw_data *d1,
+	git_win32__stack__raw_data *d2)
+{
+	return memcmp(d1, d2, sizeof(*d1));
+}
+
+int git_win32__stack_format(
+	char *pbuf, int buf_len,
+	const git_win32__stack__raw_data *pdata,
+	const char *prefix, const char *suffix)
+{
+#define MY_MAX_FILENAME 255
+
+	/* SYMBOL_INFO has char FileName[1] at the end.  The docs say to
+	 * to malloc it with extra space for your desired max filename.
+	 */
+	struct {
+		SYMBOL_INFO symbol;
+		char extra[MY_MAX_FILENAME + 1];
+	} s;
+
+	IMAGEHLP_LINE64 line;
+	int buf_used = 0;
+	unsigned int k;
+	char detail[MY_MAX_FILENAME * 2]; /* filename plus space for function name and formatting */
+	int detail_len;
+
+	if (!g_win32_stack_initialized) {
+		giterr_set(GITERR_INVALID, "git_win32_stack not initialized.");
+		return GIT_ERROR;
+	}
+
+	if (!prefix)
+		prefix = "\t";
+	if (!suffix)
+		suffix = "\n";
+
+	memset(pbuf, 0, buf_len);
+
+	memset(&s, 0, sizeof(s));
+	s.symbol.MaxNameLen = MY_MAX_FILENAME;
+	s.symbol.SizeOfStruct = sizeof(SYMBOL_INFO);
+
+	memset(&line, 0, sizeof(line));
+	line.SizeOfStruct = sizeof(IMAGEHLP_LINE64);
+
+	for (k=0; k < pdata->nr_frames; k++) {
+		DWORD64 frame_k = (DWORD64)pdata->frames[k];
+		DWORD dwUnused;
+
+		if (SymFromAddr(g_win32_stack_process, frame_k, 0, &s.symbol) &&
+			SymGetLineFromAddr64(g_win32_stack_process, frame_k, &dwUnused, &line)) {
+			const char *pslash;
+			const char *pfile;
+
+			pslash = strrchr(line.FileName, '\\');
+			pfile = ((pslash) ? (pslash+1) : line.FileName);
+			p_snprintf(detail, sizeof(detail), "%s%s:%d> %s%s",
+					   prefix, pfile, line.LineNumber, s.symbol.Name, suffix);
+		} else {
+			/* This happens when we cross into another module.
+			 * For example, in CLAR tests, this is typically
+			 * the CRT startup code.  Just print an unknown
+			 * frame and continue.
+			 */
+			p_snprintf(detail, sizeof(detail), "%s??%s", prefix, suffix);
+		}
+		detail_len = strlen(detail);
+
+		if (buf_len < (buf_used + detail_len + 1)) {
+			/* we don't have room for this frame in the buffer, so just stop. */
+			break;
+		}
+
+		memcpy(&pbuf[buf_used], detail, detail_len);
+		buf_used += detail_len;
+	}
+
+	/* "aux_id" 0 is reserved to mean no aux data. This is needed to handle
+	 * allocs that occur before the aux callbacks were registered.
+	 */
+	if (pdata->aux_id > 0) {
+		p_snprintf(detail, sizeof(detail), "%saux_id: %d%s",
+				   prefix, pdata->aux_id, suffix);
+		detail_len = strlen(detail);
+		if ((buf_used + detail_len + 1) < buf_len) {
+			memcpy(&pbuf[buf_used], detail, detail_len);
+			buf_used += detail_len;
+		}
+
+		/* If an "aux" data provider is still registered, ask it to append its detailed
+		 * data to the end of ours using the "aux_id" it gave us when this de-duped
+		 * item was created.
+		 */
+		if (g_aux_cb_lookup)
+			(g_aux_cb_lookup)(pdata->aux_id, &pbuf[buf_used], (buf_len - buf_used - 1));
+	}
+
+	return GIT_OK;
+}
+
+int git_win32__stack(
+	char * pbuf, int buf_len,
+	int skip,
+	const char *prefix, const char *suffix)
+{
+	git_win32__stack__raw_data data;
+	int error;
+
+	if ((error = git_win32__stack_capture(&data, skip)) < 0)
+		return error;
+	if ((error = git_win32__stack_format(pbuf, buf_len, &data, prefix, suffix)) < 0)
+		return error;
+	return 0;
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/win32/w32_stack.h

diff --git a/vendor/libgit2-sys/libgit2/src/win32/w32_stack.h b/vendor/libgit2-sys/libgit2/src/win32/w32_stack.h
new file mode 100644
index 0000000..5f0009e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/w32_stack.h
@@ -0,0 +1,140 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_win32_w32_stack_h__
+#define INCLUDE_win32_w32_stack_h__
+
+#include "common.h"
+
+#if defined(GIT_MSVC_CRTDBG)
+
+/**
+ * This type defines a callback to be used to augment a C stacktrace
+ * with "aux" data. This can be used, for example, to allow LibGit2Sharp
+ * (or other interpreted consumer libraries) to give us C# stacktrace
+ * data for the PInvoke.
+ *
+ * This callback will be called during crtdbg-instrumented allocs.
+ *
+ * @param aux_id [out] A returned "aux_id" representing a unique
+ * (de-duped at the C# layer) stacktrace.  "aux_id" 0 is reserved
+ * to mean no aux stacktrace data.
+ */
+typedef void (*git_win32__stack__aux_cb_alloc)(unsigned int *aux_id);
+
+/**
+ * This type defines a callback to be used to augment the output of
+ * a stacktrace.  This will be used to request the C# layer format
+ * the C# stacktrace associated with "aux_id" into the provided
+ * buffer.
+ *
+ * This callback will be called during leak reporting.
+ *
+ * @param aux_id The "aux_id" key associated with a stacktrace.
+ * @param aux_msg A buffer where a formatted message should be written.
+ * @param aux_msg_len The size of the buffer.
+ */
+typedef void (*git_win32__stack__aux_cb_lookup)(unsigned int aux_id, char *aux_msg, unsigned int aux_msg_len);
+
+/**
+ * Register an "aux" data provider to augment our C stacktrace data.
+ *
+ * This can be used, for example, to allow LibGit2Sharp (or other
+ * interpreted consumer libraries) to give us the C# stacktrace of
+ * the PInvoke.
+ *
+ * If you choose to use this feature, it should be registered during
+ * initialization and not changed for the duration of the process.
+ */
+GIT_EXTERN(int) git_win32__stack__set_aux_cb(
+	git_win32__stack__aux_cb_alloc cb_alloc,
+	git_win32__stack__aux_cb_lookup cb_lookup);
+
+/**
+ * Maximum number of stackframes to record for a
+ * single stacktrace.
+ */
+#define GIT_WIN32__STACK__MAX_FRAMES 30
+
+/**
+ * Wrapper containing the raw unprocessed stackframe
+ * data for a single stacktrace and any "aux_id".
+ *
+ * I put the aux_id first so leaks will be sorted by it.
+ * So, for example, if a specific callstack in C# leaks
+ * a repo handle, all of the pointers within the associated
+ * repo pointer will be grouped together.
+ */
+typedef struct {
+	unsigned int aux_id;
+	unsigned int nr_frames;
+	void *frames[GIT_WIN32__STACK__MAX_FRAMES];
+} git_win32__stack__raw_data;
+
+
+/**
+ * Load symbol table data.  This should be done in the primary
+ * thread at startup (under a lock if there are other threads
+ * active).
+ */
+void git_win32__stack_init(void);
+
+/**
+ * Cleanup symbol table data.  This should be done in the
+ * primary thead at shutdown (under a lock if there are other
+ * threads active).
+ */
+void git_win32__stack_cleanup(void);
+
+
+/**
+ * Capture raw stack trace data for the current process/thread.
+ *
+ * @param skip Number of initial frames to skip.  Pass 0 to
+ * begin with the caller of this routine. Pass 1 to begin
+ * with its caller.  And so on.
+ */
+int git_win32__stack_capture(git_win32__stack__raw_data *pdata, int skip);
+
+/**
+ * Compare 2 raw stacktraces with the usual -1,0,+1 result.
+ * This includes any "aux_id" values in the comparison, so that
+ * our de-dup is also "aux" context relative.
+ */
+int git_win32__stack_compare(
+	git_win32__stack__raw_data *d1,
+	git_win32__stack__raw_data *d2);
+
+/**
+ * Format raw stacktrace data into buffer WITHOUT using any mallocs.
+ *
+ * @param prefix String written before each frame; defaults to "\t".
+ * @param suffix String written after each frame; defaults to "\n".
+ */
+int git_win32__stack_format(
+	char *pbuf, int buf_len,
+	const git_win32__stack__raw_data *pdata,
+	const char *prefix, const char *suffix);
+
+/**
+ * Convenience routine to capture and format stacktrace into
+ * a buffer WITHOUT using any mallocs.  This is primarily a
+ * wrapper for testing.
+ *
+ * @param skip Number of initial frames to skip. Pass 0 to
+ * begin with the caller of this routine.  Pass 1 to begin
+ * with its caller.  And so on.
+ * @param prefix String written before each frame; defaults to "\t".
+ * @param suffix String written after each frame; defaults to "\n".
+ */
+int git_win32__stack(
+	char * pbuf, int buf_len,
+	int skip,
+	const char *prefix, const char *suffix);
+
+#endif /* GIT_MSVC_CRTDBG */
+#endif

vendor/libgit2-sys/libgit2/src/win32/w32_util.c

diff --git a/vendor/libgit2-sys/libgit2/src/win32/w32_util.c b/vendor/libgit2-sys/libgit2/src/win32/w32_util.c
new file mode 100644
index 0000000..b7b1ffa
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/w32_util.c
@@ -0,0 +1,163 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "w32_util.h"
+
+/**
+ * Creates a FindFirstFile(Ex) filter string from a UTF-8 path.
+ * The filter string enumerates all items in the directory.
+ *
+ * @param dest The buffer to receive the filter string.
+ * @param src The UTF-8 path of the directory to enumerate.
+ * @return True if the filter string was created successfully; false otherwise
+ */
+bool git_win32__findfirstfile_filter(git_win32_path dest, const char *src)
+{
+	static const wchar_t suffix[] = L"\\*";
+	int len = git_win32_path_from_utf8(dest, src);
+
+	/* Ensure the path was converted */
+	if (len < 0)
+		return false;
+
+	/* Ensure that the path does not end with a trailing slash,
+	 * because we're about to add one. Don't rely our trim_end
+	 * helper, because we want to remove the backslash even for
+	 * drive letter paths, in this case. */
+	if (len > 0 &&
+		(dest[len - 1] == L'/' || dest[len - 1] == L'\\')) {
+		dest[len - 1] = L'\0';
+		len--;
+	}
+
+	/* Ensure we have enough room to add the suffix */
+	if ((size_t)len >= GIT_WIN_PATH_UTF16 - CONST_STRLEN(suffix))
+		return false;
+
+	wcscat(dest, suffix);
+	return true;
+}
+
+/**
+ * Ensures the given path (file or folder) has the +H (hidden) attribute set.
+ *
+ * @param path The path which should receive the +H bit.
+ * @return 0 on success; -1 on failure
+ */
+int git_win32__set_hidden(const char *path, bool hidden)
+{
+	git_win32_path buf;
+	DWORD attrs, newattrs;
+
+	if (git_win32_path_from_utf8(buf, path) < 0)
+		return -1;
+
+	attrs = GetFileAttributesW(buf);
+
+	/* Ensure the path exists */
+	if (attrs == INVALID_FILE_ATTRIBUTES)
+		return -1;
+
+	if (hidden)
+		newattrs = attrs | FILE_ATTRIBUTE_HIDDEN;
+	else
+		newattrs = attrs & ~FILE_ATTRIBUTE_HIDDEN;
+
+	if (attrs != newattrs && !SetFileAttributesW(buf, newattrs)) {
+		giterr_set(GITERR_OS, "failed to %s hidden bit for '%s'",
+			hidden ? "set" : "unset", path);
+		return -1;
+	}
+
+	return 0;
+}
+
+int git_win32__hidden(bool *out, const char *path)
+{
+	git_win32_path buf;
+	DWORD attrs;
+
+	if (git_win32_path_from_utf8(buf, path) < 0)
+		return -1;
+
+	attrs = GetFileAttributesW(buf);
+
+	/* Ensure the path exists */
+	if (attrs == INVALID_FILE_ATTRIBUTES)
+		return -1;
+
+	*out = (attrs & FILE_ATTRIBUTE_HIDDEN) ? true : false;
+	return 0;
+}
+
+/**
+ * Removes any trailing backslashes from a path, except in the case of a drive
+ * letter path (C:\, D:\, etc.). This function cannot fail.
+ *
+ * @param path The path which should be trimmed.
+ * @return The length of the modified string (<= the input length)
+ */
+size_t git_win32__path_trim_end(wchar_t *str, size_t len)
+{
+	while (1) {
+		if (!len || str[len - 1] != L'\\')
+			break;
+
+		/* Don't trim backslashes from drive letter paths, which
+		 * are 3 characters long and of the form C:\, D:\, etc. */
+		if (len == 3 && git_win32__isalpha(str[0]) && str[1] == ':')
+			break;
+
+		len--;
+	}
+
+	str[len] = L'\0';
+
+	return len;
+}
+
+/**
+ * Removes any of the following namespace prefixes from a path,
+ * if found: "\??\", "\\?\", "\\?\UNC\". This function cannot fail.
+ *
+ * @param path The path which should be converted.
+ * @return The length of the modified string (<= the input length)
+ */
+size_t git_win32__canonicalize_path(wchar_t *str, size_t len)
+{
+	static const wchar_t dosdevices_prefix[] = L"\\\?\?\\";
+	static const wchar_t nt_prefix[] = L"\\\\?\\";
+	static const wchar_t unc_prefix[] = L"UNC\\";
+	size_t to_advance = 0;
+
+	/* "\??\" -- DOS Devices prefix */
+	if (len >= CONST_STRLEN(dosdevices_prefix) &&
+		!wcsncmp(str, dosdevices_prefix, CONST_STRLEN(dosdevices_prefix))) {
+		to_advance += CONST_STRLEN(dosdevices_prefix);
+		len -= CONST_STRLEN(dosdevices_prefix);
+	}
+	/* "\\?\" -- NT namespace prefix */
+	else if (len >= CONST_STRLEN(nt_prefix) &&
+		!wcsncmp(str, nt_prefix, CONST_STRLEN(nt_prefix))) {
+		to_advance += CONST_STRLEN(nt_prefix);
+		len -= CONST_STRLEN(nt_prefix);
+	}
+
+	/* "\??\UNC\", "\\?\UNC\" -- UNC prefix */
+	if (to_advance && len >= CONST_STRLEN(unc_prefix) &&
+		!wcsncmp(str + to_advance, unc_prefix, CONST_STRLEN(unc_prefix))) {
+		to_advance += CONST_STRLEN(unc_prefix);
+		len -= CONST_STRLEN(unc_prefix);
+	}
+
+	if (to_advance) {
+		memmove(str, str + to_advance, len * sizeof(wchar_t));
+		str[len] = L'\0';
+	}
+
+	return git_win32__path_trim_end(str, len);
+}

vendor/libgit2-sys/libgit2/src/win32/w32_util.h

diff --git a/vendor/libgit2-sys/libgit2/src/win32/w32_util.h b/vendor/libgit2-sys/libgit2/src/win32/w32_util.h
new file mode 100644
index 0000000..6531f47
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/w32_util.h
@@ -0,0 +1,188 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_win32_w32_util_h__
+#define INCLUDE_win32_w32_util_h__
+
+#include "common.h"
+
+#include "utf-conv.h"
+#include "posix.h"
+#include "path_w32.h"
+
+/*
+
+#include "common.h"
+#include "path.h"
+#include "path_w32.h"
+#include "utf-conv.h"
+#include "posix.h"
+#include "reparse.h"
+#include "dir.h"
+*/
+
+
+GIT_INLINE(bool) git_win32__isalpha(wchar_t c)
+{
+	return ((c >= L'A' && c <= L'Z') || (c >= L'a' && c <= L'z'));
+}
+
+/**
+ * Creates a FindFirstFile(Ex) filter string from a UTF-8 path.
+ * The filter string enumerates all items in the directory.
+ *
+ * @param dest The buffer to receive the filter string.
+ * @param src The UTF-8 path of the directory to enumerate.
+ * @return True if the filter string was created successfully; false otherwise
+ */
+bool git_win32__findfirstfile_filter(git_win32_path dest, const char *src);
+
+/**
+ * Ensures the given path (file or folder) has the +H (hidden) attribute set
+ * or unset.
+ *
+ * @param path The path that should receive the +H bit.
+ * @param hidden true to set +H, false to unset it
+ * @return 0 on success; -1 on failure
+ */
+extern int git_win32__set_hidden(const char *path, bool hidden);
+
+/**
+ * Determines if the given file or folder has the hidden attribute set.
+ * @param hidden pointer to store hidden value
+ * @param path The path that should be queried for hiddenness.
+ * @return 0 on success or an error code.
+ */
+extern int git_win32__hidden(bool *hidden, const char *path);
+
+/**
+ * Removes any trailing backslashes from a path, except in the case of a drive
+ * letter path (C:\, D:\, etc.). This function cannot fail.
+ *
+ * @param path The path which should be trimmed.
+ * @return The length of the modified string (<= the input length)
+ */
+size_t git_win32__path_trim_end(wchar_t *str, size_t len);
+
+/**
+ * Removes any of the following namespace prefixes from a path,
+ * if found: "\??\", "\\?\", "\\?\UNC\". This function cannot fail.
+ *
+ * @param path The path which should be converted.
+ * @return The length of the modified string (<= the input length)
+ */
+size_t git_win32__canonicalize_path(wchar_t *str, size_t len);
+
+/**
+ * Converts a FILETIME structure to a struct timespec.
+ *
+ * @param FILETIME A pointer to a FILETIME
+ * @param ts A pointer to the timespec structure to fill in
+ */
+GIT_INLINE(void) git_win32__filetime_to_timespec(
+	const FILETIME *ft,
+	struct timespec *ts)
+{
+	long long winTime = ((long long)ft->dwHighDateTime << 32) + ft->dwLowDateTime;
+	winTime -= 116444736000000000LL; /* Windows to Unix Epoch conversion */
+	ts->tv_sec = (time_t)(winTime / 10000000);
+#ifdef GIT_USE_NSEC
+	ts->tv_nsec = (winTime % 10000000) * 100;
+#else
+	ts->tv_nsec = 0;
+#endif
+}
+
+GIT_INLINE(void) git_win32__timeval_to_filetime(
+	FILETIME *ft, const struct p_timeval tv)
+{
+	long long ticks = (tv.tv_sec * 10000000LL) +
+		(tv.tv_usec * 10LL) + 116444736000000000LL;
+
+	ft->dwHighDateTime = ((ticks >> 32) & 0xffffffffLL);
+	ft->dwLowDateTime = (ticks & 0xffffffffLL);
+}
+
+GIT_INLINE(void) git_win32__stat_init(
+	struct stat *st,
+	DWORD dwFileAttributes,
+	DWORD nFileSizeHigh,
+	DWORD nFileSizeLow,
+	FILETIME ftCreationTime,
+	FILETIME ftLastAccessTime,
+	FILETIME ftLastWriteTime)
+{
+	mode_t mode = S_IREAD;
+
+	memset(st, 0, sizeof(struct stat));
+
+	if (dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
+		mode |= S_IFDIR;
+	else
+		mode |= S_IFREG;
+
+	if ((dwFileAttributes & FILE_ATTRIBUTE_READONLY) == 0)
+		mode |= S_IWRITE;
+
+	st->st_ino = 0;
+	st->st_gid = 0;
+	st->st_uid = 0;
+	st->st_nlink = 1;
+	st->st_mode = mode;
+	st->st_size = ((git_off_t)nFileSizeHigh << 32) + nFileSizeLow;
+	st->st_dev = _getdrive() - 1;
+	st->st_rdev = st->st_dev;
+	git_win32__filetime_to_timespec(&ftLastAccessTime, &(st->st_atim));
+	git_win32__filetime_to_timespec(&ftLastWriteTime, &(st->st_mtim));
+	git_win32__filetime_to_timespec(&ftCreationTime, &(st->st_ctim));
+}
+
+GIT_INLINE(void) git_win32__file_information_to_stat(
+	struct stat *st,
+	const BY_HANDLE_FILE_INFORMATION *fileinfo)
+{
+	git_win32__stat_init(st,
+		fileinfo->dwFileAttributes,
+		fileinfo->nFileSizeHigh,
+		fileinfo->nFileSizeLow,
+		fileinfo->ftCreationTime,
+		fileinfo->ftLastAccessTime,
+		fileinfo->ftLastWriteTime);
+}
+
+GIT_INLINE(int) git_win32__file_attribute_to_stat(
+	struct stat *st,
+	const WIN32_FILE_ATTRIBUTE_DATA *attrdata,
+	const wchar_t *path)
+{
+	git_win32__stat_init(st,
+		attrdata->dwFileAttributes,
+		attrdata->nFileSizeHigh,
+		attrdata->nFileSizeLow,
+		attrdata->ftCreationTime,
+		attrdata->ftLastAccessTime,
+		attrdata->ftLastWriteTime);
+
+	if (attrdata->dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT && path) {
+		git_win32_path target;
+
+		if (git_win32_path_readlink_w(target, path) >= 0) {
+			st->st_mode = (st->st_mode & ~S_IFMT) | S_IFLNK;
+
+			/* st_size gets the UTF-8 length of the target name, in bytes,
+			 * not counting the NULL terminator */
+			if ((st->st_size = git__utf16_to_8(NULL, 0, target)) < 0) {
+				giterr_set(GITERR_OS, "could not convert reparse point name for '%ls'", path);
+				return -1;
+			}
+		}
+	}
+
+	return 0;
+}
+
+#endif

vendor/libgit2-sys/libgit2/src/win32/win32-compat.h

diff --git a/vendor/libgit2-sys/libgit2/src/win32/win32-compat.h b/vendor/libgit2-sys/libgit2/src/win32/win32-compat.h
new file mode 100644
index 0000000..dee40a4
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/win32/win32-compat.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_win32_win32_compat_h__
+#define INCLUDE_win32_win32_compat_h__
+
+#include <stdint.h>
+#include <time.h>
+#include <wchar.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+typedef long suseconds_t;
+
+struct p_timeval {
+	time_t tv_sec;
+	suseconds_t tv_usec;
+};
+
+struct p_timespec {
+	time_t tv_sec;
+	long tv_nsec;
+};
+
+#define timespec p_timespec
+
+struct p_stat {
+	_dev_t st_dev;
+	_ino_t st_ino;
+	mode_t st_mode;
+	short st_nlink;
+	short st_uid;
+	short st_gid;
+	_dev_t st_rdev;
+	__int64 st_size;
+	struct timespec st_atim;
+	struct timespec st_mtim;
+	struct timespec st_ctim;
+#define st_atime st_atim.tv_sec
+#define st_mtime st_mtim.tv_sec
+#define st_ctime st_ctim.tv_sec
+#define st_atime_nsec st_atim.tv_nsec
+#define st_mtime_nsec st_mtim.tv_nsec
+#define st_ctime_nsec st_ctim.tv_nsec
+};
+
+#define stat p_stat
+
+#endif

vendor/libgit2-sys/libgit2/src/worktree.c

diff --git a/vendor/libgit2-sys/libgit2/src/worktree.c b/vendor/libgit2-sys/libgit2/src/worktree.c
new file mode 100644
index 0000000..48d3ef9
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/worktree.c
@@ -0,0 +1,588 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "worktree.h"
+
+#include "git2/branch.h"
+#include "git2/commit.h"
+#include "git2/worktree.h"
+
+#include "repository.h"
+
+static bool is_worktree_dir(const char *dir)
+{
+	git_buf buf = GIT_BUF_INIT;
+	int error;
+
+	if (git_buf_sets(&buf, dir) < 0)
+		return -1;
+
+	error = git_path_contains_file(&buf, "commondir")
+		&& git_path_contains_file(&buf, "gitdir")
+		&& git_path_contains_file(&buf, "HEAD");
+
+	git_buf_free(&buf);
+	return error;
+}
+
+int git_worktree_list(git_strarray *wts, git_repository *repo)
+{
+	git_vector worktrees = GIT_VECTOR_INIT;
+	git_buf path = GIT_BUF_INIT;
+	char *worktree;
+	unsigned i, len;
+	int error;
+
+	assert(wts && repo);
+
+	wts->count = 0;
+	wts->strings = NULL;
+
+	if ((error = git_buf_printf(&path, "%s/worktrees/", repo->commondir)) < 0)
+		goto exit;
+	if (!git_path_exists(path.ptr) || git_path_is_empty_dir(path.ptr))
+		goto exit;
+	if ((error = git_path_dirload(&worktrees, path.ptr, path.size, 0x0)) < 0)
+		goto exit;
+
+	len = path.size;
+
+	git_vector_foreach(&worktrees, i, worktree) {
+		git_buf_truncate(&path, len);
+		git_buf_puts(&path, worktree);
+
+		if (!is_worktree_dir(path.ptr)) {
+			git_vector_remove(&worktrees, i);
+			git__free(worktree);
+		}
+	}
+
+	wts->strings = (char **)git_vector_detach(&wts->count, NULL, &worktrees);
+
+exit:
+	git_buf_free(&path);
+
+	return error;
+}
+
+char *git_worktree__read_link(const char *base, const char *file)
+{
+	git_buf path = GIT_BUF_INIT, buf = GIT_BUF_INIT;
+
+	assert(base && file);
+
+	if (git_buf_joinpath(&path, base, file) < 0)
+		goto err;
+	if (git_futils_readbuffer(&buf, path.ptr) < 0)
+		goto err;
+	git_buf_free(&path);
+
+	git_buf_rtrim(&buf);
+
+	if (!git_path_is_relative(buf.ptr))
+		return git_buf_detach(&buf);
+
+	if (git_buf_sets(&path, base) < 0)
+		goto err;
+	if (git_path_apply_relative(&path, buf.ptr) < 0)
+		goto err;
+	git_buf_free(&buf);
+
+	return git_buf_detach(&path);
+
+err:
+	git_buf_free(&buf);
+	git_buf_free(&path);
+
+	return NULL;
+}
+
+static int write_wtfile(const char *base, const char *file, const git_buf *buf)
+{
+	git_buf path = GIT_BUF_INIT;
+	int err;
+
+	assert(base && file && buf);
+
+	if ((err = git_buf_joinpath(&path, base, file)) < 0)
+		goto out;
+
+	if ((err = git_futils_writebuffer(buf, path.ptr, O_CREAT|O_EXCL|O_WRONLY, 0644)) < 0)
+		goto out;
+
+out:
+	git_buf_free(&path);
+
+	return err;
+}
+
+static int open_worktree_dir(git_worktree **out, const char *parent, const char *dir, const char *name)
+{
+	git_buf gitdir = GIT_BUF_INIT;
+	git_worktree *wt = NULL;
+	int error = 0;
+
+	if (!is_worktree_dir(dir)) {
+		error = -1;
+		goto out;
+	}
+
+	if ((wt = git__calloc(1, sizeof(*wt))) == NULL) {
+		error = -1;
+		goto out;
+	}
+
+	if ((wt->name = git__strdup(name)) == NULL
+	    || (wt->commondir_path = git_worktree__read_link(dir, "commondir")) == NULL
+	    || (wt->gitlink_path = git_worktree__read_link(dir, "gitdir")) == NULL
+	    || (parent && (wt->parent_path = git__strdup(parent)) == NULL)
+	    || (wt->worktree_path = git_path_dirname(wt->gitlink_path)) == NULL) {
+		error = -1;
+		goto out;
+	}
+
+	if ((error = git_path_prettify_dir(&gitdir, dir, NULL)) < 0)
+		goto out;
+	wt->gitdir_path = git_buf_detach(&gitdir);
+
+	wt->locked = !!git_worktree_is_locked(NULL, wt);
+
+	*out = wt;
+
+out:
+	if (error)
+		git_worktree_free(wt);
+	git_buf_free(&gitdir);
+
+	return error;
+}
+
+int git_worktree_lookup(git_worktree **out, git_repository *repo, const char *name)
+{
+	git_buf path = GIT_BUF_INIT;
+	git_worktree *wt = NULL;
+	int error;
+
+	assert(repo && name);
+
+	*out = NULL;
+
+	if ((error = git_buf_printf(&path, "%s/worktrees/%s", repo->commondir, name)) < 0)
+		goto out;
+
+	if ((error = (open_worktree_dir(out, git_repository_workdir(repo), path.ptr, name))) < 0)
+		goto out;
+
+out:
+	git_buf_free(&path);
+
+	if (error)
+		git_worktree_free(wt);
+
+	return error;
+}
+
+int git_worktree_open_from_repository(git_worktree **out, git_repository *repo)
+{
+	git_buf parent = GIT_BUF_INIT;
+	const char *gitdir, *commondir;
+	char *name = NULL;
+	int error = 0;
+
+	if (!git_repository_is_worktree(repo)) {
+		giterr_set(GITERR_WORKTREE, "cannot open worktree of a non-worktree repo");
+		error = -1;
+		goto out;
+	}
+
+	gitdir = git_repository_path(repo);
+	commondir = git_repository_commondir(repo);
+
+	if ((error = git_path_prettify_dir(&parent, "..", commondir)) < 0)
+		goto out;
+
+	/* The name is defined by the last component in '.git/worktree/%s' */
+	name = git_path_basename(gitdir);
+
+	if ((error = open_worktree_dir(out, parent.ptr, gitdir, name)) < 0)
+		goto out;
+
+out:
+	git__free(name);
+	git_buf_free(&parent);
+
+	return error;
+}
+
+void git_worktree_free(git_worktree *wt)
+{
+	if (!wt)
+		return;
+
+	git__free(wt->commondir_path);
+	git__free(wt->worktree_path);
+	git__free(wt->gitlink_path);
+	git__free(wt->gitdir_path);
+	git__free(wt->parent_path);
+	git__free(wt->name);
+	git__free(wt);
+}
+
+int git_worktree_validate(const git_worktree *wt)
+{
+	git_buf buf = GIT_BUF_INIT;
+	int err = 0;
+
+	assert(wt);
+
+	git_buf_puts(&buf, wt->gitdir_path);
+	if (!is_worktree_dir(buf.ptr)) {
+		giterr_set(GITERR_WORKTREE,
+			"Worktree gitdir ('%s') is not valid",
+			wt->gitlink_path);
+		err = -1;
+		goto out;
+	}
+
+	if (!git_path_exists(wt->parent_path)) {
+		giterr_set(GITERR_WORKTREE,
+			"Worktree parent directory ('%s') does not exist ",
+			wt->parent_path);
+		err = -2;
+		goto out;
+	}
+
+	if (!git_path_exists(wt->commondir_path)) {
+		giterr_set(GITERR_WORKTREE,
+			"Worktree common directory ('%s') does not exist ",
+			wt->commondir_path);
+		err = -3;
+		goto out;
+	}
+
+out:
+	git_buf_free(&buf);
+
+	return err;
+}
+
+int git_worktree_add_init_options(git_worktree_add_options *opts,
+	unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(opts, version,
+		git_worktree_add_options, GIT_WORKTREE_ADD_OPTIONS_INIT);
+	return 0;
+}
+
+int git_worktree_add(git_worktree **out, git_repository *repo,
+	const char *name, const char *worktree,
+	const git_worktree_add_options *opts)
+{
+	git_buf gitdir = GIT_BUF_INIT, wddir = GIT_BUF_INIT, buf = GIT_BUF_INIT;
+	git_reference *ref = NULL, *head = NULL;
+	git_commit *commit = NULL;
+	git_repository *wt = NULL;
+	git_checkout_options coopts = GIT_CHECKOUT_OPTIONS_INIT;
+	git_worktree_add_options wtopts = GIT_WORKTREE_ADD_OPTIONS_INIT;
+	int err;
+
+	GITERR_CHECK_VERSION(
+		opts, GIT_WORKTREE_ADD_OPTIONS_VERSION, "git_worktree_add_options");
+
+	if (opts)
+		memcpy(&wtopts, opts, sizeof(wtopts));
+
+	assert(out && repo && name && worktree);
+
+	*out = NULL;
+
+	/* Create gitdir directory ".git/worktrees/<name>" */
+	if ((err = git_buf_joinpath(&gitdir, repo->commondir, "worktrees")) < 0)
+		goto out;
+	if (!git_path_exists(gitdir.ptr))
+		if ((err = git_futils_mkdir(gitdir.ptr, 0755, GIT_MKDIR_EXCL)) < 0)
+			goto out;
+	if ((err = git_buf_joinpath(&gitdir, gitdir.ptr, name)) < 0)
+		goto out;
+	if ((err = git_futils_mkdir(gitdir.ptr, 0755, GIT_MKDIR_EXCL)) < 0)
+		goto out;
+	if ((err = git_path_prettify_dir(&gitdir, gitdir.ptr, NULL)) < 0)
+		goto out;
+
+	/* Create worktree work dir */
+	if ((err = git_futils_mkdir(worktree, 0755, GIT_MKDIR_EXCL)) < 0)
+		goto out;
+	if ((err = git_path_prettify_dir(&wddir, worktree, NULL)) < 0)
+		goto out;
+
+	if (wtopts.lock) {
+		int fd;
+
+		if ((err = git_buf_joinpath(&buf, gitdir.ptr, "locked")) < 0)
+			goto out;
+
+		if ((fd = p_creat(buf.ptr, 0644)) < 0) {
+			err = fd;
+			goto out;
+		}
+
+		p_close(fd);
+		git_buf_clear(&buf);
+	}
+
+	/* Create worktree .git file */
+	if ((err = git_buf_printf(&buf, "gitdir: %s\n", gitdir.ptr)) < 0)
+		goto out;
+	if ((err = write_wtfile(wddir.ptr, ".git", &buf)) < 0)
+		goto out;
+
+	/* Create gitdir files */
+	if ((err = git_path_prettify_dir(&buf, repo->commondir, NULL) < 0)
+	    || (err = git_buf_putc(&buf, '\n')) < 0
+	    || (err = write_wtfile(gitdir.ptr, "commondir", &buf)) < 0)
+		goto out;
+	if ((err = git_buf_joinpath(&buf, wddir.ptr, ".git")) < 0
+	    || (err = git_buf_putc(&buf, '\n')) < 0
+	    || (err = write_wtfile(gitdir.ptr, "gitdir", &buf)) < 0)
+		goto out;
+
+	/* Set up worktree reference */
+	if (wtopts.ref) {
+		if (!git_reference_is_branch(wtopts.ref)) {
+			giterr_set(GITERR_WORKTREE, "reference is not a branch");
+			err = -1;
+			goto out;
+		}
+
+		if (git_branch_is_checked_out(wtopts.ref)) {
+			giterr_set(GITERR_WORKTREE, "reference is already checked out");
+			err = -1;
+			goto out;
+		}
+
+		if ((err = git_reference_dup(&ref, wtopts.ref)) < 0)
+			goto out;
+	} else {
+		if ((err = git_repository_head(&head, repo)) < 0)
+			goto out;
+		if ((err = git_commit_lookup(&commit, repo, &head->target.oid)) < 0)
+			goto out;
+		if ((err = git_branch_create(&ref, repo, name, commit, false)) < 0)
+			goto out;
+	}
+
+	/* Set worktree's HEAD */
+	if ((err = git_repository_create_head(gitdir.ptr, git_reference_name(ref))) < 0)
+		goto out;
+	if ((err = git_repository_open(&wt, wddir.ptr)) < 0)
+		goto out;
+
+	/* Checkout worktree's HEAD */
+	coopts.checkout_strategy = GIT_CHECKOUT_FORCE;
+	if ((err = git_checkout_head(wt, &coopts)) < 0)
+		goto out;
+
+	/* Load result */
+	if ((err = git_worktree_lookup(out, repo, name)) < 0)
+		goto out;
+
+out:
+	git_buf_free(&gitdir);
+	git_buf_free(&wddir);
+	git_buf_free(&buf);
+	git_reference_free(ref);
+	git_reference_free(head);
+	git_commit_free(commit);
+	git_repository_free(wt);
+
+	return err;
+}
+
+int git_worktree_lock(git_worktree *wt, const char *reason)
+{
+	git_buf buf = GIT_BUF_INIT, path = GIT_BUF_INIT;
+	int err;
+
+	assert(wt);
+
+	if ((err = git_worktree_is_locked(NULL, wt)) < 0)
+		goto out;
+
+	if ((err = git_buf_joinpath(&path, wt->gitdir_path, "locked")) < 0)
+		goto out;
+
+	if (reason)
+		git_buf_attach_notowned(&buf, reason, strlen(reason));
+
+	if ((err = git_futils_writebuffer(&buf, path.ptr, O_CREAT|O_EXCL|O_WRONLY, 0644)) < 0)
+		goto out;
+
+	wt->locked = 1;
+
+out:
+	git_buf_free(&path);
+
+	return err;
+}
+
+int git_worktree_unlock(git_worktree *wt)
+{
+	git_buf path = GIT_BUF_INIT;
+
+	assert(wt);
+
+	if (!git_worktree_is_locked(NULL, wt))
+		return 0;
+
+	if (git_buf_joinpath(&path, wt->gitdir_path, "locked") < 0)
+		return -1;
+
+	if (p_unlink(path.ptr) != 0) {
+		git_buf_free(&path);
+		return -1;
+	}
+
+	wt->locked = 0;
+
+	git_buf_free(&path);
+
+	return 0;
+}
+
+int git_worktree_is_locked(git_buf *reason, const git_worktree *wt)
+{
+	git_buf path = GIT_BUF_INIT;
+	int ret;
+
+	assert(wt);
+
+	if (reason)
+		git_buf_clear(reason);
+
+	if ((ret = git_buf_joinpath(&path, wt->gitdir_path, "locked")) < 0)
+		goto out;
+	if ((ret = git_path_exists(path.ptr)) && reason)
+		git_futils_readbuffer(reason, path.ptr);
+
+out:
+	git_buf_free(&path);
+
+	return ret;
+}
+
+const char *git_worktree_name(const git_worktree *wt)
+{
+	assert(wt);
+	return wt->name;
+}
+
+const char *git_worktree_path(const git_worktree *wt)
+{
+	assert(wt);
+	return wt->worktree_path;
+}
+
+int git_worktree_prune_init_options(
+	git_worktree_prune_options *opts,
+	unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(opts, version,
+		git_worktree_prune_options, GIT_WORKTREE_PRUNE_OPTIONS_INIT);
+	return 0;
+}
+
+int git_worktree_is_prunable(git_worktree *wt,
+	git_worktree_prune_options *opts)
+{
+	git_buf reason = GIT_BUF_INIT;
+	git_worktree_prune_options popts = GIT_WORKTREE_PRUNE_OPTIONS_INIT;
+
+	GITERR_CHECK_VERSION(
+		opts, GIT_WORKTREE_PRUNE_OPTIONS_VERSION,
+		"git_worktree_prune_options");
+
+	if (opts)
+		memcpy(&popts, opts, sizeof(popts));
+
+	if ((popts.flags & GIT_WORKTREE_PRUNE_LOCKED) == 0 &&
+		git_worktree_is_locked(&reason, wt))
+	{
+		if (!reason.size)
+			git_buf_attach_notowned(&reason, "no reason given", 15);
+		giterr_set(GITERR_WORKTREE, "Not pruning locked working tree: '%s'", reason.ptr);
+		git_buf_free(&reason);
+
+		return 0;
+	}
+
+	if ((popts.flags & GIT_WORKTREE_PRUNE_VALID) == 0 &&
+		git_worktree_validate(wt) == 0)
+	{
+		giterr_set(GITERR_WORKTREE, "Not pruning valid working tree");
+		return 0;
+	}
+
+	return 1;
+}
+
+int git_worktree_prune(git_worktree *wt,
+	git_worktree_prune_options *opts)
+{
+	git_worktree_prune_options popts = GIT_WORKTREE_PRUNE_OPTIONS_INIT;
+	git_buf path = GIT_BUF_INIT;
+	char *wtpath;
+	int err;
+
+	GITERR_CHECK_VERSION(
+		opts, GIT_WORKTREE_PRUNE_OPTIONS_VERSION,
+		"git_worktree_prune_options");
+
+	if (opts)
+		memcpy(&popts, opts, sizeof(popts));
+
+	if (!git_worktree_is_prunable(wt, &popts)) {
+		err = -1;
+		goto out;
+	}
+
+	/* Delete gitdir in parent repository */
+	if ((err = git_buf_printf(&path, "%s/worktrees/%s", wt->commondir_path, wt->name)) < 0)
+		goto out;
+	if (!git_path_exists(path.ptr))
+	{
+		giterr_set(GITERR_WORKTREE, "Worktree gitdir '%s' does not exist", path.ptr);
+		err = -1;
+		goto out;
+	}
+	if ((err = git_futils_rmdir_r(path.ptr, NULL, GIT_RMDIR_REMOVE_FILES)) < 0)
+		goto out;
+
+	/* Skip deletion of the actual working tree if it does
+	 * not exist or deletion was not requested */
+	if ((popts.flags & GIT_WORKTREE_PRUNE_WORKING_TREE) == 0 ||
+		!git_path_exists(wt->gitlink_path))
+	{
+		goto out;
+	}
+
+	if ((wtpath = git_path_dirname(wt->gitlink_path)) == NULL)
+		goto out;
+	git_buf_attach(&path, wtpath, 0);
+	if (!git_path_exists(path.ptr))
+	{
+		giterr_set(GITERR_WORKTREE, "Working tree '%s' does not exist", path.ptr);
+		err = -1;
+		goto out;
+	}
+	if ((err = git_futils_rmdir_r(path.ptr, NULL, GIT_RMDIR_REMOVE_FILES)) < 0)
+		goto out;
+
+out:
+	git_buf_free(&path);
+
+	return err;
+}

vendor/libgit2-sys/libgit2/src/worktree.h

diff --git a/vendor/libgit2-sys/libgit2/src/worktree.h b/vendor/libgit2-sys/libgit2/src/worktree.h
new file mode 100644
index 0000000..1d40c3a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/worktree.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_worktree_h__
+#define INCLUDE_worktree_h__
+
+#include "common.h"
+
+#include "git2/common.h"
+#include "git2/worktree.h"
+
+struct git_worktree {
+	/* Name of the working tree. This is the name of the
+	 * containing directory in the `$PARENT/.git/worktrees/`
+	 * directory. */
+	char *name;
+
+	/* Path to the where the worktree lives in the filesystem */
+	char *worktree_path;
+	/* Path to the .git file in the working tree's repository */
+	char *gitlink_path;
+	/* Path to the .git directory inside the parent's
+	 * worktrees directory */
+	char *gitdir_path;
+	/* Path to the common directory contained in the parent
+	 * repository */
+	char *commondir_path;
+	/* Path to the parent's working directory */
+	char *parent_path;
+
+	int locked:1;
+};
+
+char *git_worktree__read_link(const char *base, const char *file);
+
+#endif

vendor/libgit2-sys/libgit2/src/xdiff/xdiff.h

diff --git a/vendor/libgit2-sys/libgit2/src/xdiff/xdiff.h b/vendor/libgit2-sys/libgit2/src/xdiff/xdiff.h
new file mode 100644
index 0000000..5b13e77
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/xdiff/xdiff.h
@@ -0,0 +1,150 @@
+/*
+ *  LibXDiff by Davide Libenzi ( File Differential Library )
+ *  Copyright (C) 2003  Davide Libenzi
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, see
+ *  <http://www.gnu.org/licenses/>.
+ *
+ *  Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#if !defined(XDIFF_H)
+#define XDIFF_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* #ifdef __cplusplus */
+
+/* xpparm_t.flags */
+#define XDF_NEED_MINIMAL (1 << 0)
+
+#define XDF_IGNORE_WHITESPACE (1 << 1)
+#define XDF_IGNORE_WHITESPACE_CHANGE (1 << 2)
+#define XDF_IGNORE_WHITESPACE_AT_EOL (1 << 3)
+#define XDF_IGNORE_CR_AT_EOL (1 << 4)
+#define XDF_WHITESPACE_FLAGS (XDF_IGNORE_WHITESPACE | \
+			      XDF_IGNORE_WHITESPACE_CHANGE | \
+			      XDF_IGNORE_WHITESPACE_AT_EOL | \
+			      XDF_IGNORE_CR_AT_EOL)
+
+#define XDF_IGNORE_BLANK_LINES (1 << 7)
+
+#define XDF_PATIENCE_DIFF (1 << 14)
+#define XDF_HISTOGRAM_DIFF (1 << 15)
+#define XDF_DIFF_ALGORITHM_MASK (XDF_PATIENCE_DIFF | XDF_HISTOGRAM_DIFF)
+#define XDF_DIFF_ALG(x) ((x) & XDF_DIFF_ALGORITHM_MASK)
+
+#define XDF_INDENT_HEURISTIC (1 << 23)
+
+/* xdemitconf_t.flags */
+#define XDL_EMIT_FUNCNAMES (1 << 0)
+#define XDL_EMIT_FUNCCONTEXT (1 << 2)
+
+#define XDL_MMB_READONLY (1 << 0)
+
+#define XDL_MMF_ATOMIC (1 << 0)
+
+#define XDL_BDOP_INS 1
+#define XDL_BDOP_CPY 2
+#define XDL_BDOP_INSB 3
+
+/* merge simplification levels */
+#define XDL_MERGE_MINIMAL 0
+#define XDL_MERGE_EAGER 1
+#define XDL_MERGE_ZEALOUS 2
+#define XDL_MERGE_ZEALOUS_ALNUM 3
+
+/* merge favor modes */
+#define XDL_MERGE_FAVOR_OURS 1
+#define XDL_MERGE_FAVOR_THEIRS 2
+#define XDL_MERGE_FAVOR_UNION 3
+
+/* merge output styles */
+#define XDL_MERGE_DIFF3 1
+
+typedef struct s_mmfile {
+	char *ptr;
+	size_t size;
+} mmfile_t;
+
+typedef struct s_mmbuffer {
+	char *ptr;
+	size_t size;
+} mmbuffer_t;
+
+typedef struct s_xpparam {
+	unsigned long flags;
+
+	/* See Documentation/diff-options.txt. */
+	char **anchors;
+	size_t anchors_nr;
+} xpparam_t;
+
+typedef struct s_xdemitcb {
+	void *priv;
+	int (*outf)(void *, mmbuffer_t *, int);
+} xdemitcb_t;
+
+typedef long (*find_func_t)(const char *line, long line_len, char *buffer, long buffer_size, void *priv);
+
+typedef int (*xdl_emit_hunk_consume_func_t)(long start_a, long count_a,
+					    long start_b, long count_b,
+					    void *cb_data);
+
+typedef struct s_xdemitconf {
+	long ctxlen;
+	long interhunkctxlen;
+	unsigned long flags;
+	find_func_t find_func;
+	void *find_func_priv;
+	xdl_emit_hunk_consume_func_t hunk_func;
+} xdemitconf_t;
+
+typedef struct s_bdiffparam {
+	long bsize;
+} bdiffparam_t;
+
+
+#define xdl_malloc(x) git__malloc(x)
+#define xdl_free(ptr) git__free(ptr)
+#define xdl_realloc(ptr,x) git__realloc(ptr,x)
+
+void *xdl_mmfile_first(mmfile_t *mmf, long *size);
+long xdl_mmfile_size(mmfile_t *mmf);
+
+int xdl_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+	     xdemitconf_t const *xecfg, xdemitcb_t *ecb);
+
+typedef struct s_xmparam {
+	xpparam_t xpp;
+	int marker_size;
+	int level;
+	int favor;
+	int style;
+	const char *ancestor;	/* label for orig */
+	const char *file1;	/* label for mf1 */
+	const char *file2;	/* label for mf2 */
+} xmparam_t;
+
+#define DEFAULT_CONFLICT_MARKER_SIZE 7
+
+int xdl_merge(mmfile_t *orig, mmfile_t *mf1, mmfile_t *mf2,
+		xmparam_t const *xmp, mmbuffer_t *result);
+
+#ifdef __cplusplus
+}
+#endif /* #ifdef __cplusplus */
+
+#endif /* #if !defined(XDIFF_H) */

vendor/libgit2-sys/libgit2/src/xdiff/xdiffi.c

diff --git a/vendor/libgit2-sys/libgit2/src/xdiff/xdiffi.c b/vendor/libgit2-sys/libgit2/src/xdiff/xdiffi.c
new file mode 100644
index 0000000..3a71ef6
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/xdiff/xdiffi.c
@@ -0,0 +1,1060 @@
+/*
+ *  LibXDiff by Davide Libenzi ( File Differential Library )
+ *  Copyright (C) 2003	Davide Libenzi
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, see
+ *  <http://www.gnu.org/licenses/>.
+ *
+ *  Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#include "xinclude.h"
+#include "integer.h"
+
+
+#define XDL_MAX_COST_MIN 256
+#define XDL_HEUR_MIN_COST 256
+#define XDL_LINE_MAX (long)((1UL << (CHAR_BIT * sizeof(long) - 1)) - 1)
+#define XDL_SNAKE_CNT 20
+#define XDL_K_HEUR 4
+
+/** Declare a function as always inlined. */
+#if defined(_MSC_VER)
+# define XDL_INLINE(type) static __inline type
+#else
+# define XDL_INLINE(type) static inline type
+#endif
+
+typedef struct s_xdpsplit {
+	long i1, i2;
+	int min_lo, min_hi;
+} xdpsplit_t;
+
+
+
+
+static long xdl_split(unsigned long const *ha1, long off1, long lim1,
+		      unsigned long const *ha2, long off2, long lim2,
+		      long *kvdf, long *kvdb, int need_min, xdpsplit_t *spl,
+		      xdalgoenv_t *xenv);
+static xdchange_t *xdl_add_change(xdchange_t *xscr, long i1, long i2, long chg1, long chg2);
+
+
+
+
+
+/*
+ * See "An O(ND) Difference Algorithm and its Variations", by Eugene Myers.
+ * Basically considers a "box" (off1, off2, lim1, lim2) and scan from both
+ * the forward diagonal starting from (off1, off2) and the backward diagonal
+ * starting from (lim1, lim2). If the K values on the same diagonal crosses
+ * returns the furthest point of reach. We might end up having to expensive
+ * cases using this algorithm is full, so a little bit of heuristic is needed
+ * to cut the search and to return a suboptimal point.
+ */
+static long xdl_split(unsigned long const *ha1, long off1, long lim1,
+		      unsigned long const *ha2, long off2, long lim2,
+		      long *kvdf, long *kvdb, int need_min, xdpsplit_t *spl,
+		      xdalgoenv_t *xenv) {
+	long dmin = off1 - lim2, dmax = lim1 - off2;
+	long fmid = off1 - off2, bmid = lim1 - lim2;
+	long odd = (fmid - bmid) & 1;
+	long fmin = fmid, fmax = fmid;
+	long bmin = bmid, bmax = bmid;
+	long ec, d, i1, i2, prev1, best, dd, v, k;
+
+	/*
+	 * Set initial diagonal values for both forward and backward path.
+	 */
+	kvdf[fmid] = off1;
+	kvdb[bmid] = lim1;
+
+	for (ec = 1;; ec++) {
+		int got_snake = 0;
+
+		/*
+		 * We need to extent the diagonal "domain" by one. If the next
+		 * values exits the box boundaries we need to change it in the
+		 * opposite direction because (max - min) must be a power of two.
+		 * Also we initialize the external K value to -1 so that we can
+		 * avoid extra conditions check inside the core loop.
+		 */
+		if (fmin > dmin)
+			kvdf[--fmin - 1] = -1;
+		else
+			++fmin;
+		if (fmax < dmax)
+			kvdf[++fmax + 1] = -1;
+		else
+			--fmax;
+
+		for (d = fmax; d >= fmin; d -= 2) {
+			if (kvdf[d - 1] >= kvdf[d + 1])
+				i1 = kvdf[d - 1] + 1;
+			else
+				i1 = kvdf[d + 1];
+			prev1 = i1;
+			i2 = i1 - d;
+			for (; i1 < lim1 && i2 < lim2 && ha1[i1] == ha2[i2]; i1++, i2++);
+			if (i1 - prev1 > xenv->snake_cnt)
+				got_snake = 1;
+			kvdf[d] = i1;
+			if (odd && bmin <= d && d <= bmax && kvdb[d] <= i1) {
+				spl->i1 = i1;
+				spl->i2 = i2;
+				spl->min_lo = spl->min_hi = 1;
+				return ec;
+			}
+		}
+
+		/*
+		 * We need to extent the diagonal "domain" by one. If the next
+		 * values exits the box boundaries we need to change it in the
+		 * opposite direction because (max - min) must be a power of two.
+		 * Also we initialize the external K value to -1 so that we can
+		 * avoid extra conditions check inside the core loop.
+		 */
+		if (bmin > dmin)
+			kvdb[--bmin - 1] = XDL_LINE_MAX;
+		else
+			++bmin;
+		if (bmax < dmax)
+			kvdb[++bmax + 1] = XDL_LINE_MAX;
+		else
+			--bmax;
+
+		for (d = bmax; d >= bmin; d -= 2) {
+			if (kvdb[d - 1] < kvdb[d + 1])
+				i1 = kvdb[d - 1];
+			else
+				i1 = kvdb[d + 1] - 1;
+			prev1 = i1;
+			i2 = i1 - d;
+			for (; i1 > off1 && i2 > off2 && ha1[i1 - 1] == ha2[i2 - 1]; i1--, i2--);
+			if (prev1 - i1 > xenv->snake_cnt)
+				got_snake = 1;
+			kvdb[d] = i1;
+			if (!odd && fmin <= d && d <= fmax && i1 <= kvdf[d]) {
+				spl->i1 = i1;
+				spl->i2 = i2;
+				spl->min_lo = spl->min_hi = 1;
+				return ec;
+			}
+		}
+
+		if (need_min)
+			continue;
+
+		/*
+		 * If the edit cost is above the heuristic trigger and if
+		 * we got a good snake, we sample current diagonals to see
+		 * if some of the, have reached an "interesting" path. Our
+		 * measure is a function of the distance from the diagonal
+		 * corner (i1 + i2) penalized with the distance from the
+		 * mid diagonal itself. If this value is above the current
+		 * edit cost times a magic factor (XDL_K_HEUR) we consider
+		 * it interesting.
+		 */
+		if (got_snake && ec > xenv->heur_min) {
+			for (best = 0, d = fmax; d >= fmin; d -= 2) {
+				dd = d > fmid ? d - fmid: fmid - d;
+				i1 = kvdf[d];
+				i2 = i1 - d;
+				v = (i1 - off1) + (i2 - off2) - dd;
+
+				if (v > XDL_K_HEUR * ec && v > best &&
+				    off1 + xenv->snake_cnt <= i1 && i1 < lim1 &&
+				    off2 + xenv->snake_cnt <= i2 && i2 < lim2) {
+					for (k = 1; ha1[i1 - k] == ha2[i2 - k]; k++)
+						if (k == xenv->snake_cnt) {
+							best = v;
+							spl->i1 = i1;
+							spl->i2 = i2;
+							break;
+						}
+				}
+			}
+			if (best > 0) {
+				spl->min_lo = 1;
+				spl->min_hi = 0;
+				return ec;
+			}
+
+			for (best = 0, d = bmax; d >= bmin; d -= 2) {
+				dd = d > bmid ? d - bmid: bmid - d;
+				i1 = kvdb[d];
+				i2 = i1 - d;
+				v = (lim1 - i1) + (lim2 - i2) - dd;
+
+				if (v > XDL_K_HEUR * ec && v > best &&
+				    off1 < i1 && i1 <= lim1 - xenv->snake_cnt &&
+				    off2 < i2 && i2 <= lim2 - xenv->snake_cnt) {
+					for (k = 0; ha1[i1 + k] == ha2[i2 + k]; k++)
+						if (k == xenv->snake_cnt - 1) {
+							best = v;
+							spl->i1 = i1;
+							spl->i2 = i2;
+							break;
+						}
+				}
+			}
+			if (best > 0) {
+				spl->min_lo = 0;
+				spl->min_hi = 1;
+				return ec;
+			}
+		}
+
+		/*
+		 * Enough is enough. We spent too much time here and now we collect
+		 * the furthest reaching path using the (i1 + i2) measure.
+		 */
+		if (ec >= xenv->mxcost) {
+			long fbest, fbest1, bbest, bbest1;
+
+			fbest = fbest1 = -1;
+			for (d = fmax; d >= fmin; d -= 2) {
+				i1 = XDL_MIN(kvdf[d], lim1);
+				i2 = i1 - d;
+				if (lim2 < i2)
+					i1 = lim2 + d, i2 = lim2;
+				if (fbest < i1 + i2) {
+					fbest = i1 + i2;
+					fbest1 = i1;
+				}
+			}
+
+			bbest = bbest1 = XDL_LINE_MAX;
+			for (d = bmax; d >= bmin; d -= 2) {
+				i1 = XDL_MAX(off1, kvdb[d]);
+				i2 = i1 - d;
+				if (i2 < off2)
+					i1 = off2 + d, i2 = off2;
+				if (i1 + i2 < bbest) {
+					bbest = i1 + i2;
+					bbest1 = i1;
+				}
+			}
+
+			if ((lim1 + lim2) - bbest < fbest - (off1 + off2)) {
+				spl->i1 = fbest1;
+				spl->i2 = fbest - fbest1;
+				spl->min_lo = 1;
+				spl->min_hi = 0;
+			} else {
+				spl->i1 = bbest1;
+				spl->i2 = bbest - bbest1;
+				spl->min_lo = 0;
+				spl->min_hi = 1;
+			}
+			return ec;
+		}
+	}
+}
+
+
+/*
+ * Rule: "Divide et Impera". Recursively split the box in sub-boxes by calling
+ * the box splitting function. Note that the real job (marking changed lines)
+ * is done in the two boundary reaching checks.
+ */
+int xdl_recs_cmp(diffdata_t *dd1, long off1, long lim1,
+		 diffdata_t *dd2, long off2, long lim2,
+		 long *kvdf, long *kvdb, int need_min, xdalgoenv_t *xenv) {
+	unsigned long const *ha1 = dd1->ha, *ha2 = dd2->ha;
+
+	/*
+	 * Shrink the box by walking through each diagonal snake (SW and NE).
+	 */
+	for (; off1 < lim1 && off2 < lim2 && ha1[off1] == ha2[off2]; off1++, off2++);
+	for (; off1 < lim1 && off2 < lim2 && ha1[lim1 - 1] == ha2[lim2 - 1]; lim1--, lim2--);
+
+	/*
+	 * If one dimension is empty, then all records on the other one must
+	 * be obviously changed.
+	 */
+	if (off1 == lim1) {
+		char *rchg2 = dd2->rchg;
+		long *rindex2 = dd2->rindex;
+
+		for (; off2 < lim2; off2++)
+			rchg2[rindex2[off2]] = 1;
+	} else if (off2 == lim2) {
+		char *rchg1 = dd1->rchg;
+		long *rindex1 = dd1->rindex;
+
+		for (; off1 < lim1; off1++)
+			rchg1[rindex1[off1]] = 1;
+	} else {
+		xdpsplit_t spl;
+		spl.i1 = spl.i2 = 0;
+
+		/*
+		 * Divide ...
+		 */
+		if (xdl_split(ha1, off1, lim1, ha2, off2, lim2, kvdf, kvdb,
+			      need_min, &spl, xenv) < 0) {
+
+			return -1;
+		}
+
+		/*
+		 * ... et Impera.
+		 */
+		if (xdl_recs_cmp(dd1, off1, spl.i1, dd2, off2, spl.i2,
+				 kvdf, kvdb, spl.min_lo, xenv) < 0 ||
+		    xdl_recs_cmp(dd1, spl.i1, lim1, dd2, spl.i2, lim2,
+				 kvdf, kvdb, spl.min_hi, xenv) < 0) {
+
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+
+int xdl_do_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+		xdfenv_t *xe) {
+	size_t ndiags, allocsize;
+	long *kvd, *kvdf, *kvdb;
+	xdalgoenv_t xenv;
+	diffdata_t dd1, dd2;
+
+	if (XDF_DIFF_ALG(xpp->flags) == XDF_PATIENCE_DIFF)
+		return xdl_do_patience_diff(mf1, mf2, xpp, xe);
+
+	if (XDF_DIFF_ALG(xpp->flags) == XDF_HISTOGRAM_DIFF)
+		return xdl_do_histogram_diff(mf1, mf2, xpp, xe);
+
+	if (xdl_prepare_env(mf1, mf2, xpp, xe) < 0) {
+
+		return -1;
+	}
+
+	/*
+	 * Allocate and setup K vectors to be used by the differential algorithm.
+	 * One is to store the forward path and one to store the backward path.
+	 */
+	GITERR_CHECK_ALLOC_ADD3(&ndiags, xe->xdf1.nreff, xe->xdf2.nreff, 3);
+	GITERR_CHECK_ALLOC_MULTIPLY(&allocsize, ndiags, 2);
+	GITERR_CHECK_ALLOC_ADD(&allocsize, allocsize, 2);
+	GITERR_CHECK_ALLOC_MULTIPLY(&allocsize, allocsize, sizeof(long));
+
+	if (!(kvd = (long *) xdl_malloc(allocsize))) {
+		xdl_free_env(xe);
+		return -1;
+	}
+	kvdf = kvd;
+	kvdb = kvdf + ndiags;
+	kvdf += xe->xdf2.nreff + 1;
+	kvdb += xe->xdf2.nreff + 1;
+
+	xenv.mxcost = xdl_bogosqrt(ndiags);
+	if (xenv.mxcost < XDL_MAX_COST_MIN)
+		xenv.mxcost = XDL_MAX_COST_MIN;
+	xenv.snake_cnt = XDL_SNAKE_CNT;
+	xenv.heur_min = XDL_HEUR_MIN_COST;
+
+	dd1.nrec = xe->xdf1.nreff;
+	dd1.ha = xe->xdf1.ha;
+	dd1.rchg = xe->xdf1.rchg;
+	dd1.rindex = xe->xdf1.rindex;
+	dd2.nrec = xe->xdf2.nreff;
+	dd2.ha = xe->xdf2.ha;
+	dd2.rchg = xe->xdf2.rchg;
+	dd2.rindex = xe->xdf2.rindex;
+
+	if (xdl_recs_cmp(&dd1, 0, dd1.nrec, &dd2, 0, dd2.nrec,
+			 kvdf, kvdb, (xpp->flags & XDF_NEED_MINIMAL) != 0, &xenv) < 0) {
+
+		xdl_free(kvd);
+		xdl_free_env(xe);
+		return -1;
+	}
+
+	xdl_free(kvd);
+
+	return 0;
+}
+
+
+static xdchange_t *xdl_add_change(xdchange_t *xscr, long i1, long i2, long chg1, long chg2) {
+	xdchange_t *xch;
+
+	if (!(xch = (xdchange_t *) xdl_malloc(sizeof(xdchange_t))))
+		return NULL;
+
+	xch->next = xscr;
+	xch->i1 = i1;
+	xch->i2 = i2;
+	xch->chg1 = chg1;
+	xch->chg2 = chg2;
+	xch->ignore = 0;
+
+	return xch;
+}
+
+
+static int recs_match(xrecord_t *rec1, xrecord_t *rec2, long flags)
+{
+	return (rec1->ha == rec2->ha &&
+		xdl_recmatch(rec1->ptr, rec1->size,
+			     rec2->ptr, rec2->size,
+			     flags));
+}
+
+/*
+ * If a line is indented more than this, get_indent() just returns this value.
+ * This avoids having to do absurd amounts of work for data that are not
+ * human-readable text, and also ensures that the output of get_indent fits within
+ * an int.
+ */
+#define MAX_INDENT 200
+
+/*
+ * Return the amount of indentation of the specified line, treating TAB as 8
+ * columns. Return -1 if line is empty or contains only whitespace. Clamp the
+ * output value at MAX_INDENT.
+ */
+static int get_indent(xrecord_t *rec)
+{
+	long i;
+	int ret = 0;
+
+	for (i = 0; i < rec->size; i++) {
+		char c = rec->ptr[i];
+
+		if (!XDL_ISSPACE(c))
+			return ret;
+		else if (c == ' ')
+			ret += 1;
+		else if (c == '\t')
+			ret += 8 - ret % 8;
+		/* ignore other whitespace characters */
+
+		if (ret >= MAX_INDENT)
+			return MAX_INDENT;
+	}
+
+	/* The line contains only whitespace. */
+	return -1;
+}
+
+/*
+ * If more than this number of consecutive blank rows are found, just return this
+ * value. This avoids requiring O(N^2) work for pathological cases, and also
+ * ensures that the output of score_split fits in an int.
+ */
+#define MAX_BLANKS 20
+
+/* Characteristics measured about a hypothetical split position. */
+struct split_measurement {
+	/*
+	 * Is the split at the end of the file (aside from any blank lines)?
+	 */
+	int end_of_file;
+
+	/*
+	 * How much is the line immediately following the split indented (or -1 if
+	 * the line is blank):
+	 */
+	int indent;
+
+	/*
+	 * How many consecutive lines above the split are blank?
+	 */
+	int pre_blank;
+
+	/*
+	 * How much is the nearest non-blank line above the split indented (or -1
+	 * if there is no such line)?
+	 */
+	int pre_indent;
+
+	/*
+	 * How many lines after the line following the split are blank?
+	 */
+	int post_blank;
+
+	/*
+	 * How much is the nearest non-blank line after the line following the
+	 * split indented (or -1 if there is no such line)?
+	 */
+	int post_indent;
+};
+
+struct split_score {
+	/* The effective indent of this split (smaller is preferred). */
+	int effective_indent;
+
+	/* Penalty for this split (smaller is preferred). */
+	int penalty;
+};
+
+/*
+ * Fill m with information about a hypothetical split of xdf above line split.
+ */
+static void measure_split(const xdfile_t *xdf, long split,
+			  struct split_measurement *m)
+{
+	long i;
+
+	if (split >= xdf->nrec) {
+		m->end_of_file = 1;
+		m->indent = -1;
+	} else {
+		m->end_of_file = 0;
+		m->indent = get_indent(xdf->recs[split]);
+	}
+
+	m->pre_blank = 0;
+	m->pre_indent = -1;
+	for (i = split - 1; i >= 0; i--) {
+		m->pre_indent = get_indent(xdf->recs[i]);
+		if (m->pre_indent != -1)
+			break;
+		m->pre_blank += 1;
+		if (m->pre_blank == MAX_BLANKS) {
+			m->pre_indent = 0;
+			break;
+		}
+	}
+
+	m->post_blank = 0;
+	m->post_indent = -1;
+	for (i = split + 1; i < xdf->nrec; i++) {
+		m->post_indent = get_indent(xdf->recs[i]);
+		if (m->post_indent != -1)
+			break;
+		m->post_blank += 1;
+		if (m->post_blank == MAX_BLANKS) {
+			m->post_indent = 0;
+			break;
+		}
+	}
+}
+
+/*
+ * The empirically-determined weight factors used by score_split() below.
+ * Larger values means that the position is a less favorable place to split.
+ *
+ * Note that scores are only ever compared against each other, so multiplying
+ * all of these weight/penalty values by the same factor wouldn't change the
+ * heuristic's behavior. Still, we need to set that arbitrary scale *somehow*.
+ * In practice, these numbers are chosen to be large enough that they can be
+ * adjusted relative to each other with sufficient precision despite using
+ * integer math.
+ */
+
+/* Penalty if there are no non-blank lines before the split */
+#define START_OF_FILE_PENALTY 1
+
+/* Penalty if there are no non-blank lines after the split */
+#define END_OF_FILE_PENALTY 21
+
+/* Multiplier for the number of blank lines around the split */
+#define TOTAL_BLANK_WEIGHT (-30)
+
+/* Multiplier for the number of blank lines after the split */
+#define POST_BLANK_WEIGHT 6
+
+/*
+ * Penalties applied if the line is indented more than its predecessor
+ */
+#define RELATIVE_INDENT_PENALTY (-4)
+#define RELATIVE_INDENT_WITH_BLANK_PENALTY 10
+
+/*
+ * Penalties applied if the line is indented less than both its predecessor and
+ * its successor
+ */
+#define RELATIVE_OUTDENT_PENALTY 24
+#define RELATIVE_OUTDENT_WITH_BLANK_PENALTY 17
+
+/*
+ * Penalties applied if the line is indented less than its predecessor but not
+ * less than its successor
+ */
+#define RELATIVE_DEDENT_PENALTY 23
+#define RELATIVE_DEDENT_WITH_BLANK_PENALTY 17
+
+/*
+ * We only consider whether the sum of the effective indents for splits are
+ * less than (-1), equal to (0), or greater than (+1) each other. The resulting
+ * value is multiplied by the following weight and combined with the penalty to
+ * determine the better of two scores.
+ */
+#define INDENT_WEIGHT 60
+
+/*
+ * Compute a badness score for the hypothetical split whose measurements are
+ * stored in m. The weight factors were determined empirically using the tools and
+ * corpus described in
+ *
+ *     https://github.com/mhagger/diff-slider-tools
+ *
+ * Also see that project if you want to improve the weights based on, for example,
+ * a larger or more diverse corpus.
+ */
+static void score_add_split(const struct split_measurement *m, struct split_score *s)
+{
+	/*
+	 * A place to accumulate penalty factors (positive makes this index more
+	 * favored):
+	 */
+	int post_blank, total_blank, indent, any_blanks;
+
+	if (m->pre_indent == -1 && m->pre_blank == 0)
+		s->penalty += START_OF_FILE_PENALTY;
+
+	if (m->end_of_file)
+		s->penalty += END_OF_FILE_PENALTY;
+
+	/*
+	 * Set post_blank to the number of blank lines following the split,
+	 * including the line immediately after the split:
+	 */
+	post_blank = (m->indent == -1) ? 1 + m->post_blank : 0;
+	total_blank = m->pre_blank + post_blank;
+
+	/* Penalties based on nearby blank lines: */
+	s->penalty += TOTAL_BLANK_WEIGHT * total_blank;
+	s->penalty += POST_BLANK_WEIGHT * post_blank;
+
+	if (m->indent != -1)
+		indent = m->indent;
+	else
+		indent = m->post_indent;
+
+	any_blanks = (total_blank != 0);
+
+	/* Note that the effective indent is -1 at the end of the file: */
+	s->effective_indent += indent;
+
+	if (indent == -1) {
+		/* No additional adjustments needed. */
+	} else if (m->pre_indent == -1) {
+		/* No additional adjustments needed. */
+	} else if (indent > m->pre_indent) {
+		/*
+		 * The line is indented more than its predecessor.
+		 */
+		s->penalty += any_blanks ?
+			RELATIVE_INDENT_WITH_BLANK_PENALTY :
+			RELATIVE_INDENT_PENALTY;
+	} else if (indent == m->pre_indent) {
+		/*
+		 * The line has the same indentation level as its predecessor.
+		 * No additional adjustments needed.
+		 */
+	} else {
+		/*
+		 * The line is indented less than its predecessor. It could be
+		 * the block terminator of the previous block, but it could
+		 * also be the start of a new block (e.g., an "else" block, or
+		 * maybe the previous block didn't have a block terminator).
+		 * Try to distinguish those cases based on what comes next:
+		 */
+		if (m->post_indent != -1 && m->post_indent > indent) {
+			/*
+			 * The following line is indented more. So it is likely
+			 * that this line is the start of a block.
+			 */
+			s->penalty += any_blanks ?
+				RELATIVE_OUTDENT_WITH_BLANK_PENALTY :
+				RELATIVE_OUTDENT_PENALTY;
+		} else {
+			/*
+			 * That was probably the end of a block.
+			 */
+			s->penalty += any_blanks ?
+				RELATIVE_DEDENT_WITH_BLANK_PENALTY :
+				RELATIVE_DEDENT_PENALTY;
+		}
+	}
+}
+
+static int score_cmp(struct split_score *s1, struct split_score *s2)
+{
+	/* -1 if s1.effective_indent < s2->effective_indent, etc. */
+	int cmp_indents = ((s1->effective_indent > s2->effective_indent) -
+			   (s1->effective_indent < s2->effective_indent));
+
+	return INDENT_WEIGHT * cmp_indents + (s1->penalty - s2->penalty);
+}
+
+/*
+ * Represent a group of changed lines in an xdfile_t (i.e., a contiguous group
+ * of lines that was inserted or deleted from the corresponding version of the
+ * file). We consider there to be such a group at the beginning of the file, at
+ * the end of the file, and between any two unchanged lines, though most such
+ * groups will usually be empty.
+ *
+ * If the first line in a group is equal to the line following the group, then
+ * the group can be slid down. Similarly, if the last line in a group is equal
+ * to the line preceding the group, then the group can be slid up. See
+ * group_slide_down() and group_slide_up().
+ *
+ * Note that loops that are testing for changed lines in xdf->rchg do not need
+ * index bounding since the array is prepared with a zero at position -1 and N.
+ */
+struct xdlgroup {
+	/*
+	 * The index of the first changed line in the group, or the index of
+	 * the unchanged line above which the (empty) group is located.
+	 */
+	long start;
+
+	/*
+	 * The index of the first unchanged line after the group. For an empty
+	 * group, end is equal to start.
+	 */
+	long end;
+};
+
+/*
+ * Initialize g to point at the first group in xdf.
+ */
+static void group_init(xdfile_t *xdf, struct xdlgroup *g)
+{
+	g->start = g->end = 0;
+	while (xdf->rchg[g->end])
+		g->end++;
+}
+
+/*
+ * Move g to describe the next (possibly empty) group in xdf and return 0. If g
+ * is already at the end of the file, do nothing and return -1.
+ */
+XDL_INLINE(int) group_next(xdfile_t *xdf, struct xdlgroup *g)
+{
+	if (g->end == xdf->nrec)
+		return -1;
+
+	g->start = g->end + 1;
+	for (g->end = g->start; xdf->rchg[g->end]; g->end++)
+		;
+
+	return 0;
+}
+
+/*
+ * Move g to describe the previous (possibly empty) group in xdf and return 0.
+ * If g is already at the beginning of the file, do nothing and return -1.
+ */
+XDL_INLINE(int) group_previous(xdfile_t *xdf, struct xdlgroup *g)
+{
+	if (g->start == 0)
+		return -1;
+
+	g->end = g->start - 1;
+	for (g->start = g->end; xdf->rchg[g->start - 1]; g->start--)
+		;
+
+	return 0;
+}
+
+/*
+ * If g can be slid toward the end of the file, do so, and if it bumps into a
+ * following group, expand this group to include it. Return 0 on success or -1
+ * if g cannot be slid down.
+ */
+static int group_slide_down(xdfile_t *xdf, struct xdlgroup *g, long flags)
+{
+	if (g->end < xdf->nrec &&
+	    recs_match(xdf->recs[g->start], xdf->recs[g->end], flags)) {
+		xdf->rchg[g->start++] = 0;
+		xdf->rchg[g->end++] = 1;
+
+		while (xdf->rchg[g->end])
+			g->end++;
+
+		return 0;
+	} else {
+		return -1;
+	}
+}
+
+/*
+ * If g can be slid toward the beginning of the file, do so, and if it bumps
+ * into a previous group, expand this group to include it. Return 0 on success
+ * or -1 if g cannot be slid up.
+ */
+static int group_slide_up(xdfile_t *xdf, struct xdlgroup *g, long flags)
+{
+	if (g->start > 0 &&
+	    recs_match(xdf->recs[g->start - 1], xdf->recs[g->end - 1], flags)) {
+		xdf->rchg[--g->start] = 1;
+		xdf->rchg[--g->end] = 0;
+
+		while (xdf->rchg[g->start - 1])
+			g->start--;
+
+		return 0;
+	} else {
+		return -1;
+	}
+}
+
+static void xdl_bug(const char *msg)
+{
+	fprintf(stderr, "BUG: %s\n", msg);
+	exit(1);
+}
+
+/*
+ * Move back and forward change groups for a consistent and pretty diff output.
+ * This also helps in finding joinable change groups and reducing the diff
+ * size.
+ */
+int xdl_change_compact(xdfile_t *xdf, xdfile_t *xdfo, long flags) {
+	struct xdlgroup g, go;
+	long earliest_end, end_matching_other;
+	long groupsize;
+
+	group_init(xdf, &g);
+	group_init(xdfo, &go);
+
+	while (1) {
+		/* If the group is empty in the to-be-compacted file, skip it: */
+		if (g.end == g.start)
+			goto next;
+
+		/*
+		 * Now shift the change up and then down as far as possible in
+		 * each direction. If it bumps into any other changes, merge them.
+		 */
+		do {
+			groupsize = g.end - g.start;
+
+			/*
+			 * Keep track of the last "end" index that causes this
+			 * group to align with a group of changed lines in the
+			 * other file. -1 indicates that we haven't found such
+			 * a match yet:
+			 */
+			end_matching_other = -1;
+
+			/* Shift the group backward as much as possible: */
+			while (!group_slide_up(xdf, &g, flags))
+				if (group_previous(xdfo, &go))
+					xdl_bug("group sync broken sliding up");
+
+			/*
+			 * This is this highest that this group can be shifted.
+			 * Record its end index:
+			 */
+			earliest_end = g.end;
+
+			if (go.end > go.start)
+				end_matching_other = g.end;
+
+			/* Now shift the group forward as far as possible: */
+			while (1) {
+				if (group_slide_down(xdf, &g, flags))
+					break;
+				if (group_next(xdfo, &go))
+					xdl_bug("group sync broken sliding down");
+
+				if (go.end > go.start)
+					end_matching_other = g.end;
+			}
+		} while (groupsize != g.end - g.start);
+
+		/*
+		 * If the group can be shifted, then we can possibly use this
+		 * freedom to produce a more intuitive diff.
+		 *
+		 * The group is currently shifted as far down as possible, so the
+		 * heuristics below only have to handle upwards shifts.
+		 */
+
+		if (g.end == earliest_end) {
+			/* no shifting was possible */
+		} else if (end_matching_other != -1) {
+			/*
+			 * Move the possibly merged group of changes back to line
+			 * up with the last group of changes from the other file
+			 * that it can align with.
+			 */
+			while (go.end == go.start) {
+				if (group_slide_up(xdf, &g, flags))
+					xdl_bug("match disappeared");
+				if (group_previous(xdfo, &go))
+					xdl_bug("group sync broken sliding to match");
+			}
+		} else if (flags & XDF_INDENT_HEURISTIC) {
+			/*
+			 * Indent heuristic: a group of pure add/delete lines
+			 * implies two splits, one between the end of the "before"
+			 * context and the start of the group, and another between
+			 * the end of the group and the beginning of the "after"
+			 * context. Some splits are aesthetically better and some
+			 * are worse. We compute a badness "score" for each split,
+			 * and add the scores for the two splits to define a
+			 * "score" for each position that the group can be shifted
+			 * to. Then we pick the shift with the lowest score.
+			 */
+			long shift, best_shift = -1;
+			struct split_score best_score;
+
+			for (shift = earliest_end; shift <= g.end; shift++) {
+				struct split_measurement m;
+				struct split_score score = {0, 0};
+
+				measure_split(xdf, shift, &m);
+				score_add_split(&m, &score);
+				measure_split(xdf, shift - groupsize, &m);
+				score_add_split(&m, &score);
+				if (best_shift == -1 ||
+				    score_cmp(&score, &best_score) <= 0) {
+					best_score.effective_indent = score.effective_indent;
+					best_score.penalty = score.penalty;
+					best_shift = shift;
+				}
+			}
+
+			while (g.end > best_shift) {
+				if (group_slide_up(xdf, &g, flags))
+					xdl_bug("best shift unreached");
+				if (group_previous(xdfo, &go))
+					xdl_bug("group sync broken sliding to blank line");
+			}
+		}
+
+	next:
+		/* Move past the just-processed group: */
+		if (group_next(xdf, &g))
+			break;
+		if (group_next(xdfo, &go))
+			xdl_bug("group sync broken moving to next group");
+	}
+
+	if (!group_next(xdfo, &go))
+		xdl_bug("group sync broken at end of file");
+
+	return 0;
+}
+
+
+int xdl_build_script(xdfenv_t *xe, xdchange_t **xscr) {
+	xdchange_t *cscr = NULL, *xch;
+	char *rchg1 = xe->xdf1.rchg, *rchg2 = xe->xdf2.rchg;
+	long i1, i2, l1, l2;
+
+	/*
+	 * Trivial. Collects "groups" of changes and creates an edit script.
+	 */
+	for (i1 = xe->xdf1.nrec, i2 = xe->xdf2.nrec; i1 >= 0 || i2 >= 0; i1--, i2--)
+		if (rchg1[i1 - 1] || rchg2[i2 - 1]) {
+			for (l1 = i1; rchg1[i1 - 1]; i1--);
+			for (l2 = i2; rchg2[i2 - 1]; i2--);
+
+			if (!(xch = xdl_add_change(cscr, i1, i2, l1 - i1, l2 - i2))) {
+				xdl_free_script(cscr);
+				return -1;
+			}
+			cscr = xch;
+		}
+
+	*xscr = cscr;
+
+	return 0;
+}
+
+
+void xdl_free_script(xdchange_t *xscr) {
+	xdchange_t *xch;
+
+	while ((xch = xscr) != NULL) {
+		xscr = xscr->next;
+		xdl_free(xch);
+	}
+}
+
+static int xdl_call_hunk_func(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
+			      xdemitconf_t const *xecfg)
+{
+	xdchange_t *xch, *xche;
+
+	(void)xe;
+
+	for (xch = xscr; xch; xch = xche->next) {
+		xche = xdl_get_hunk(&xch, xecfg);
+		if (!xch)
+			break;
+		if (xecfg->hunk_func(xch->i1, xche->i1 + xche->chg1 - xch->i1,
+				     xch->i2, xche->i2 + xche->chg2 - xch->i2,
+				     ecb->priv) < 0)
+			return -1;
+	}
+	return 0;
+}
+
+static void xdl_mark_ignorable(xdchange_t *xscr, xdfenv_t *xe, long flags)
+{
+	xdchange_t *xch;
+
+	for (xch = xscr; xch; xch = xch->next) {
+		int ignore = 1;
+		xrecord_t **rec;
+		long i;
+
+		rec = &xe->xdf1.recs[xch->i1];
+		for (i = 0; i < xch->chg1 && ignore; i++)
+			ignore = xdl_blankline(rec[i]->ptr, rec[i]->size, flags);
+
+		rec = &xe->xdf2.recs[xch->i2];
+		for (i = 0; i < xch->chg2 && ignore; i++)
+			ignore = xdl_blankline(rec[i]->ptr, rec[i]->size, flags);
+
+		xch->ignore = ignore;
+	}
+}
+
+int xdl_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+	     xdemitconf_t const *xecfg, xdemitcb_t *ecb) {
+	xdchange_t *xscr;
+	xdfenv_t xe;
+	emit_func_t ef = xecfg->hunk_func ? xdl_call_hunk_func : xdl_emit_diff;
+
+	if (xdl_do_diff(mf1, mf2, xpp, &xe) < 0) {
+
+		return -1;
+	}
+	if (xdl_change_compact(&xe.xdf1, &xe.xdf2, xpp->flags) < 0 ||
+	    xdl_change_compact(&xe.xdf2, &xe.xdf1, xpp->flags) < 0 ||
+	    xdl_build_script(&xe, &xscr) < 0) {
+
+		xdl_free_env(&xe);
+		return -1;
+	}
+	if (xscr) {
+		if (xpp->flags & XDF_IGNORE_BLANK_LINES)
+			xdl_mark_ignorable(xscr, &xe, xpp->flags);
+
+		if (ef(&xe, xscr, ecb, xecfg) < 0) {
+
+			xdl_free_script(xscr);
+			xdl_free_env(&xe);
+			return -1;
+		}
+		xdl_free_script(xscr);
+	}
+	xdl_free_env(&xe);
+
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/xdiff/xdiffi.h

diff --git a/vendor/libgit2-sys/libgit2/src/xdiff/xdiffi.h b/vendor/libgit2-sys/libgit2/src/xdiff/xdiffi.h
new file mode 100644
index 0000000..8f1c7c8
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/xdiff/xdiffi.h
@@ -0,0 +1,64 @@
+/*
+ *  LibXDiff by Davide Libenzi ( File Differential Library )
+ *  Copyright (C) 2003  Davide Libenzi
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, see
+ *  <http://www.gnu.org/licenses/>.
+ *
+ *  Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#if !defined(XDIFFI_H)
+#define XDIFFI_H
+
+
+typedef struct s_diffdata {
+	long nrec;
+	unsigned long const *ha;
+	long *rindex;
+	char *rchg;
+} diffdata_t;
+
+typedef struct s_xdalgoenv {
+	long mxcost;
+	long snake_cnt;
+	long heur_min;
+} xdalgoenv_t;
+
+typedef struct s_xdchange {
+	struct s_xdchange *next;
+	long i1, i2;
+	long chg1, chg2;
+	int ignore;
+} xdchange_t;
+
+
+
+int xdl_recs_cmp(diffdata_t *dd1, long off1, long lim1,
+		 diffdata_t *dd2, long off2, long lim2,
+		 long *kvdf, long *kvdb, int need_min, xdalgoenv_t *xenv);
+int xdl_do_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+		xdfenv_t *xe);
+int xdl_change_compact(xdfile_t *xdf, xdfile_t *xdfo, long flags);
+int xdl_build_script(xdfenv_t *xe, xdchange_t **xscr);
+void xdl_free_script(xdchange_t *xscr);
+int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
+		  xdemitconf_t const *xecfg);
+int xdl_do_patience_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+		xdfenv_t *env);
+int xdl_do_histogram_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+		xdfenv_t *env);
+
+#endif /* #if !defined(XDIFFI_H) */

vendor/libgit2-sys/libgit2/src/xdiff/xemit.c

diff --git a/vendor/libgit2-sys/libgit2/src/xdiff/xemit.c b/vendor/libgit2-sys/libgit2/src/xdiff/xemit.c
new file mode 100644
index 0000000..0ffa655
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/xdiff/xemit.c
@@ -0,0 +1,314 @@
+/*
+ *  LibXDiff by Davide Libenzi ( File Differential Library )
+ *  Copyright (C) 2003	Davide Libenzi
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, see
+ *  <http://www.gnu.org/licenses/>.
+ *
+ *  Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#include "xinclude.h"
+
+static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec) {
+
+	*rec = xdf->recs[ri]->ptr;
+
+	return xdf->recs[ri]->size;
+}
+
+
+static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *ecb) {
+	long size, psize = (long)strlen(pre);
+	char const *rec;
+
+	size = xdl_get_rec(xdf, ri, &rec);
+	if (xdl_emit_diffrec(rec, size, pre, psize, ecb) < 0) {
+
+		return -1;
+	}
+
+	return 0;
+}
+
+
+/*
+ * Starting at the passed change atom, find the latest change atom to be included
+ * inside the differential hunk according to the specified configuration.
+ * Also advance xscr if the first changes must be discarded.
+ */
+xdchange_t *xdl_get_hunk(xdchange_t **xscr, xdemitconf_t const *xecfg)
+{
+	xdchange_t *xch, *xchp, *lxch;
+	long max_common = 2 * xecfg->ctxlen + xecfg->interhunkctxlen;
+	long max_ignorable = xecfg->ctxlen;
+	unsigned long ignored = 0; /* number of ignored blank lines */
+
+	/* remove ignorable changes that are too far before other changes */
+	for (xchp = *xscr; xchp && xchp->ignore; xchp = xchp->next) {
+		xch = xchp->next;
+
+		if (xch == NULL ||
+		    xch->i1 - (xchp->i1 + xchp->chg1) >= max_ignorable)
+			*xscr = xch;
+	}
+
+	if (*xscr == NULL)
+		return NULL;
+
+	lxch = *xscr;
+
+	for (xchp = *xscr, xch = xchp->next; xch; xchp = xch, xch = xch->next) {
+		long distance = xch->i1 - (xchp->i1 + xchp->chg1);
+		if (distance > max_common)
+			break;
+
+		if (distance < max_ignorable && (!xch->ignore || lxch == xchp)) {
+			lxch = xch;
+			ignored = 0;
+		} else if (distance < max_ignorable && xch->ignore) {
+			ignored += xch->chg2;
+		} else if (lxch != xchp &&
+			   xch->i1 + ignored - (lxch->i1 + lxch->chg1) > (unsigned long)max_common) {
+			break;
+		} else if (!xch->ignore) {
+			lxch = xch;
+			ignored = 0;
+		} else {
+			ignored += xch->chg2;
+		}
+	}
+
+	return lxch;
+}
+
+
+static long def_ff(const char *rec, long len, char *buf, long sz, void *priv)
+{
+	(void)priv;
+
+	if (len > 0 &&
+			(isalpha((unsigned char)*rec) || /* identifier? */
+			 *rec == '_' || /* also identifier? */
+			 *rec == '$')) { /* identifiers from VMS and other esoterico */
+		if (len > sz)
+			len = sz;
+		while (0 < len && isspace((unsigned char)rec[len - 1]))
+			len--;
+		memcpy(buf, rec, len);
+		return len;
+	}
+	return -1;
+}
+
+static long match_func_rec(xdfile_t *xdf, xdemitconf_t const *xecfg, long ri,
+			   char *buf, long sz)
+{
+	const char *rec;
+	long len = xdl_get_rec(xdf, ri, &rec);
+	if (!xecfg->find_func)
+		return def_ff(rec, len, buf, sz, xecfg->find_func_priv);
+	return xecfg->find_func(rec, len, buf, sz, xecfg->find_func_priv);
+}
+
+static int is_func_rec(xdfile_t *xdf, xdemitconf_t const *xecfg, long ri)
+{
+	char dummy[1];
+	return match_func_rec(xdf, xecfg, ri, dummy, sizeof(dummy)) >= 0;
+}
+
+struct func_line {
+	long len;
+	char buf[80];
+};
+
+static long get_func_line(xdfenv_t *xe, xdemitconf_t const *xecfg,
+			  struct func_line *func_line, long start, long limit)
+{
+	long l, size, step = (start > limit) ? -1 : 1;
+	char *buf, dummy[1];
+
+	buf = func_line ? func_line->buf : dummy;
+	size = func_line ? sizeof(func_line->buf) : sizeof(dummy);
+
+	for (l = start; l != limit && 0 <= l && l < xe->xdf1.nrec; l += step) {
+		long len = match_func_rec(&xe->xdf1, xecfg, l, buf, size);
+		if (len >= 0) {
+			if (func_line)
+				func_line->len = len;
+			return l;
+		}
+	}
+	return -1;
+}
+
+static int is_empty_rec(xdfile_t *xdf, long ri)
+{
+	const char *rec;
+	long len = xdl_get_rec(xdf, ri, &rec);
+
+	while (len > 0 && XDL_ISSPACE(*rec)) {
+		rec++;
+		len--;
+	}
+	return !len;
+}
+
+int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
+		  xdemitconf_t const *xecfg) {
+	long s1, s2, e1, e2, lctx;
+	xdchange_t *xch, *xche;
+	long funclineprev = -1;
+	struct func_line func_line = { 0 };
+
+	for (xch = xscr; xch; xch = xche->next) {
+		xche = xdl_get_hunk(&xch, xecfg);
+		if (!xch)
+			break;
+
+		s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
+		s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);
+
+		if (xecfg->flags & XDL_EMIT_FUNCCONTEXT) {
+			long fs1, i1 = xch->i1;
+
+			/* Appended chunk? */
+			if (i1 >= xe->xdf1.nrec) {
+				long i2 = xch->i2;
+
+				/*
+				 * We don't need additional context if
+				 * a whole function was added.
+				 */
+				while (i2 < xe->xdf2.nrec) {
+					if (is_func_rec(&xe->xdf2, xecfg, i2))
+						goto post_context_calculation;
+					i2++;
+				}
+
+				/*
+				 * Otherwise get more context from the
+				 * pre-image.
+				 */
+				i1 = xe->xdf1.nrec - 1;
+			}
+
+			fs1 = get_func_line(xe, xecfg, NULL, i1, -1);
+			while (fs1 > 0 && !is_empty_rec(&xe->xdf1, fs1 - 1) &&
+			       !is_func_rec(&xe->xdf1, xecfg, fs1 - 1))
+				fs1--;
+			if (fs1 < 0)
+				fs1 = 0;
+			if (fs1 < s1) {
+				s2 -= s1 - fs1;
+				s1 = fs1;
+			}
+		}
+
+ post_context_calculation:
+		lctx = xecfg->ctxlen;
+		lctx = XDL_MIN(lctx, xe->xdf1.nrec - (xche->i1 + xche->chg1));
+		lctx = XDL_MIN(lctx, xe->xdf2.nrec - (xche->i2 + xche->chg2));
+
+		e1 = xche->i1 + xche->chg1 + lctx;
+		e2 = xche->i2 + xche->chg2 + lctx;
+
+		if (xecfg->flags & XDL_EMIT_FUNCCONTEXT) {
+			long fe1 = get_func_line(xe, xecfg, NULL,
+						 xche->i1 + xche->chg1,
+						 xe->xdf1.nrec);
+			while (fe1 > 0 && is_empty_rec(&xe->xdf1, fe1 - 1))
+				fe1--;
+			if (fe1 < 0)
+				fe1 = xe->xdf1.nrec;
+			if (fe1 > e1) {
+				e2 += fe1 - e1;
+				e1 = fe1;
+			}
+
+			/*
+			 * Overlap with next change?  Then include it
+			 * in the current hunk and start over to find
+			 * its new end.
+			 */
+			if (xche->next) {
+				long l = XDL_MIN(xche->next->i1,
+						 xe->xdf1.nrec - 1);
+				if (l - xecfg->ctxlen <= e1 ||
+				    get_func_line(xe, xecfg, NULL, l, e1) < 0) {
+					xche = xche->next;
+					goto post_context_calculation;
+				}
+			}
+		}
+
+		/*
+		 * Emit current hunk header.
+		 */
+
+		if (xecfg->flags & XDL_EMIT_FUNCNAMES) {
+			get_func_line(xe, xecfg, &func_line,
+				      s1 - 1, funclineprev);
+			funclineprev = s1 - 1;
+		}
+		if (xdl_emit_hunk_hdr(s1 + 1, e1 - s1, s2 + 1, e2 - s2,
+				      func_line.buf, func_line.len, ecb) < 0)
+			return -1;
+
+		/*
+		 * Emit pre-context.
+		 */
+		for (; s2 < xch->i2; s2++)
+			if (xdl_emit_record(&xe->xdf2, s2, " ", ecb) < 0)
+				return -1;
+
+		for (s1 = xch->i1, s2 = xch->i2;; xch = xch->next) {
+			/*
+			 * Merge previous with current change atom.
+			 */
+			for (; s1 < xch->i1 && s2 < xch->i2; s1++, s2++)
+				if (xdl_emit_record(&xe->xdf2, s2, " ", ecb) < 0)
+					return -1;
+
+			/*
+			 * Removes lines from the first file.
+			 */
+			for (s1 = xch->i1; s1 < xch->i1 + xch->chg1; s1++)
+				if (xdl_emit_record(&xe->xdf1, s1, "-", ecb) < 0)
+					return -1;
+
+			/*
+			 * Adds lines from the second file.
+			 */
+			for (s2 = xch->i2; s2 < xch->i2 + xch->chg2; s2++)
+				if (xdl_emit_record(&xe->xdf2, s2, "+", ecb) < 0)
+					return -1;
+
+			if (xch == xche)
+				break;
+			s1 = xch->i1 + xch->chg1;
+			s2 = xch->i2 + xch->chg2;
+		}
+
+		/*
+		 * Emit post-context.
+		 */
+		for (s2 = xche->i2 + xche->chg2; s2 < e2; s2++)
+			if (xdl_emit_record(&xe->xdf2, s2, " ", ecb) < 0)
+				return -1;
+	}
+
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/xdiff/xemit.h

diff --git a/vendor/libgit2-sys/libgit2/src/xdiff/xemit.h b/vendor/libgit2-sys/libgit2/src/xdiff/xemit.h
new file mode 100644
index 0000000..1b9887e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/xdiff/xemit.h
@@ -0,0 +1,36 @@
+/*
+ *  LibXDiff by Davide Libenzi ( File Differential Library )
+ *  Copyright (C) 2003  Davide Libenzi
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, see
+ *  <http://www.gnu.org/licenses/>.
+ *
+ *  Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#if !defined(XEMIT_H)
+#define XEMIT_H
+
+
+typedef int (*emit_func_t)(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
+			   xdemitconf_t const *xecfg);
+
+xdchange_t *xdl_get_hunk(xdchange_t **xscr, xdemitconf_t const *xecfg);
+int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
+		  xdemitconf_t const *xecfg);
+
+
+
+#endif /* #if !defined(XEMIT_H) */

vendor/libgit2-sys/libgit2/src/xdiff/xhistogram.c

diff --git a/vendor/libgit2-sys/libgit2/src/xdiff/xhistogram.c b/vendor/libgit2-sys/libgit2/src/xdiff/xhistogram.c
new file mode 100644
index 0000000..ca8605e
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/xdiff/xhistogram.c
@@ -0,0 +1,372 @@
+/*
+ * Copyright (C) 2010, Google Inc.
+ * and other copyright owners as documented in JGit's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "xinclude.h"
+#include "xtypes.h"
+#include "xdiff.h"
+
+#define MAX_PTR	UINT_MAX
+#define MAX_CNT	UINT_MAX
+
+#define LINE_END(n) (line##n + count##n - 1)
+#define LINE_END_PTR(n) (*line##n + *count##n - 1)
+
+struct histindex {
+	struct record {
+		unsigned int ptr, cnt;
+		struct record *next;
+	} **records, /* an occurrence */
+	  **line_map; /* map of line to record chain */
+	chastore_t rcha;
+	unsigned int *next_ptrs;
+	unsigned int table_bits,
+		     records_size,
+		     line_map_size;
+
+	unsigned int max_chain_length,
+		     key_shift,
+		     ptr_shift;
+
+	unsigned int cnt,
+		     has_common;
+
+	xdfenv_t *env;
+	xpparam_t const *xpp;
+};
+
+struct region {
+	unsigned int begin1, end1;
+	unsigned int begin2, end2;
+};
+
+#define LINE_MAP(i, a) (i->line_map[(a) - i->ptr_shift])
+
+#define NEXT_PTR(index, ptr) \
+	(index->next_ptrs[(ptr) - index->ptr_shift])
+
+#define CNT(index, ptr) \
+	((LINE_MAP(index, ptr))->cnt)
+
+#define REC(env, s, l) \
+	(env->xdf##s.recs[l - 1])
+
+static int cmp_recs(xpparam_t const *xpp,
+	xrecord_t *r1, xrecord_t *r2)
+{
+	return r1->ha == r2->ha &&
+		xdl_recmatch(r1->ptr, r1->size, r2->ptr, r2->size,
+			    xpp->flags);
+}
+
+#define CMP_ENV(xpp, env, s1, l1, s2, l2) \
+	(cmp_recs(xpp, REC(env, s1, l1), REC(env, s2, l2)))
+
+#define CMP(i, s1, l1, s2, l2) \
+	(cmp_recs(i->xpp, REC(i->env, s1, l1), REC(i->env, s2, l2)))
+
+#define TABLE_HASH(index, side, line) \
+	XDL_HASHLONG((REC(index->env, side, line))->ha, index->table_bits)
+
+static int scanA(struct histindex *index, unsigned int line1, unsigned int count1)
+{
+	unsigned int ptr;
+	unsigned int tbl_idx;
+	unsigned int chain_len;
+	struct record **rec_chain, *rec;
+
+	for (ptr = LINE_END(1); line1 <= ptr; ptr--) {
+		tbl_idx = TABLE_HASH(index, 1, ptr);
+		rec_chain = index->records + tbl_idx;
+		rec = *rec_chain;
+
+		chain_len = 0;
+		while (rec) {
+			if (CMP(index, 1, rec->ptr, 1, ptr)) {
+				/*
+				 * ptr is identical to another element. Insert
+				 * it onto the front of the existing element
+				 * chain.
+				 */
+				NEXT_PTR(index, ptr) = rec->ptr;
+				rec->ptr = ptr;
+				/* cap rec->cnt at MAX_CNT */
+				rec->cnt = XDL_MIN(MAX_CNT, rec->cnt + 1);
+				LINE_MAP(index, ptr) = rec;
+				goto continue_scan;
+			}
+
+			rec = rec->next;
+			chain_len++;
+		}
+
+		if (chain_len == index->max_chain_length)
+			return -1;
+
+		/*
+		 * This is the first time we have ever seen this particular
+		 * element in the sequence. Construct a new chain for it.
+		 */
+		if (!(rec = xdl_cha_alloc(&index->rcha)))
+			return -1;
+		rec->ptr = ptr;
+		rec->cnt = 1;
+		rec->next = *rec_chain;
+		*rec_chain = rec;
+		LINE_MAP(index, ptr) = rec;
+
+continue_scan:
+		; /* no op */
+	}
+
+	return 0;
+}
+
+static int try_lcs(
+	struct histindex *index, struct region *lcs, unsigned int b_ptr,
+	unsigned int line1, unsigned int count1,
+	unsigned int line2, unsigned int count2)
+{
+	unsigned int b_next = b_ptr + 1;
+	struct record *rec = index->records[TABLE_HASH(index, 2, b_ptr)];
+	unsigned int as, ae, bs, be, np, rc;
+	int should_break;
+
+	for (; rec; rec = rec->next) {
+		if (rec->cnt > index->cnt) {
+			if (!index->has_common)
+				index->has_common = CMP(index, 1, rec->ptr, 2, b_ptr);
+			continue;
+		}
+
+		as = rec->ptr;
+		if (!CMP(index, 1, as, 2, b_ptr))
+			continue;
+
+		index->has_common = 1;
+		for (;;) {
+			should_break = 0;
+			np = NEXT_PTR(index, as);
+			bs = b_ptr;
+			ae = as;
+			be = bs;
+			rc = rec->cnt;
+
+			while (line1 < as && line2 < bs
+				&& CMP(index, 1, as - 1, 2, bs - 1)) {
+				as--;
+				bs--;
+				if (1 < rc)
+					rc = XDL_MIN(rc, CNT(index, as));
+			}
+			while (ae < LINE_END(1) && be < LINE_END(2)
+				&& CMP(index, 1, ae + 1, 2, be + 1)) {
+				ae++;
+				be++;
+				if (1 < rc)
+					rc = XDL_MIN(rc, CNT(index, ae));
+			}
+
+			if (b_next <= be)
+				b_next = be + 1;
+			if (lcs->end1 - lcs->begin1 < ae - as || rc < index->cnt) {
+				lcs->begin1 = as;
+				lcs->begin2 = bs;
+				lcs->end1 = ae;
+				lcs->end2 = be;
+				index->cnt = rc;
+			}
+
+			if (np == 0)
+				break;
+
+			while (np <= ae) {
+				np = NEXT_PTR(index, np);
+				if (np == 0) {
+					should_break = 1;
+					break;
+				}
+			}
+
+			if (should_break)
+				break;
+
+			as = np;
+		}
+	}
+	return b_next;
+}
+
+static int find_lcs(
+	struct histindex *index, struct region *lcs,
+	unsigned int line1, unsigned int count1,
+	unsigned int line2, unsigned int count2)
+{
+	unsigned int b_ptr;
+
+	if (scanA(index, line1, count1))
+		return -1;
+
+	index->cnt = index->max_chain_length + 1;
+
+	for (b_ptr = line2; b_ptr <= LINE_END(2); )
+		b_ptr = try_lcs(index, lcs, b_ptr, line1, count1, line2, count2);
+
+	return index->has_common && index->max_chain_length < index->cnt;
+}
+
+static int fall_back_to_classic_diff(struct histindex *index,
+		int line1, int count1, int line2, int count2)
+{
+	xpparam_t xpp;
+	xpp.flags = index->xpp->flags & ~XDF_DIFF_ALGORITHM_MASK;
+
+	return xdl_fall_back_diff(index->env, &xpp,
+				  line1, count1, line2, count2);
+}
+
+static int histogram_diff(
+	xpparam_t const *xpp, xdfenv_t *env,
+	unsigned int line1, unsigned int count1,
+	unsigned int line2, unsigned int count2)
+{
+	struct histindex index;
+	struct region lcs;
+	size_t sz;
+	int result = -1;
+
+	if (count1 <= 0 && count2 <= 0)
+		return 0;
+
+	if (LINE_END(1) >= MAX_PTR)
+		return -1;
+
+	if (!count1) {
+		while(count2--)
+			env->xdf2.rchg[line2++ - 1] = 1;
+		return 0;
+	} else if (!count2) {
+		while(count1--)
+			env->xdf1.rchg[line1++ - 1] = 1;
+		return 0;
+	}
+
+	memset(&index, 0, sizeof(index));
+
+	index.env = env;
+	index.xpp = xpp;
+
+	index.records = NULL;
+	index.line_map = NULL;
+	/* in case of early xdl_cha_free() */
+	index.rcha.head = NULL;
+
+	index.table_bits = xdl_hashbits(count1);
+	sz = index.records_size = 1 << index.table_bits;
+	GITERR_CHECK_ALLOC_MULTIPLY(&sz, sz, sizeof(struct record *));
+
+	if (!(index.records = (struct record **) xdl_malloc(sz)))
+		goto cleanup;
+	memset(index.records, 0, sz);
+
+	sz = index.line_map_size = count1;
+	sz *= sizeof(struct record *);
+	if (!(index.line_map = (struct record **) xdl_malloc(sz)))
+		goto cleanup;
+	memset(index.line_map, 0, sz);
+
+	sz = index.line_map_size;
+	sz *= sizeof(unsigned int);
+	if (!(index.next_ptrs = (unsigned int *) xdl_malloc(sz)))
+		goto cleanup;
+	memset(index.next_ptrs, 0, sz);
+
+	/* lines / 4 + 1 comes from xprepare.c:xdl_prepare_ctx() */
+	if (xdl_cha_init(&index.rcha, sizeof(struct record), count1 / 4 + 1) < 0)
+		goto cleanup;
+
+	index.ptr_shift = line1;
+	index.max_chain_length = 64;
+
+	memset(&lcs, 0, sizeof(lcs));
+	if (find_lcs(&index, &lcs, line1, count1, line2, count2))
+		result = fall_back_to_classic_diff(&index, line1, count1, line2, count2);
+	else {
+		if (lcs.begin1 == 0 && lcs.begin2 == 0) {
+			while (count1--)
+				env->xdf1.rchg[line1++ - 1] = 1;
+			while (count2--)
+				env->xdf2.rchg[line2++ - 1] = 1;
+			result = 0;
+		} else {
+			result = histogram_diff(xpp, env,
+						line1, lcs.begin1 - line1,
+						line2, lcs.begin2 - line2);
+			if (result)
+				goto cleanup;
+			result = histogram_diff(xpp, env,
+						lcs.end1 + 1, LINE_END(1) - lcs.end1,
+						lcs.end2 + 1, LINE_END(2) - lcs.end2);
+			if (result)
+				goto cleanup;
+		}
+	}
+
+cleanup:
+	xdl_free(index.records);
+	xdl_free(index.line_map);
+	xdl_free(index.next_ptrs);
+	xdl_cha_free(&index.rcha);
+
+	return result;
+}
+
+int xdl_do_histogram_diff(mmfile_t *file1, mmfile_t *file2,
+	xpparam_t const *xpp, xdfenv_t *env)
+{
+	if (xdl_prepare_env(file1, file2, xpp, env) < 0)
+		return -1;
+
+	return histogram_diff(xpp, env,
+		env->xdf1.dstart + 1, env->xdf1.dend - env->xdf1.dstart + 1,
+		env->xdf2.dstart + 1, env->xdf2.dend - env->xdf2.dstart + 1);
+}

vendor/libgit2-sys/libgit2/src/xdiff/xinclude.h

diff --git a/vendor/libgit2-sys/libgit2/src/xdiff/xinclude.h b/vendor/libgit2-sys/libgit2/src/xdiff/xinclude.h
new file mode 100644
index 0000000..068ce42
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/xdiff/xinclude.h
@@ -0,0 +1,47 @@
+/*
+ *  LibXDiff by Davide Libenzi ( File Differential Library )
+ *  Copyright (C) 2003  Davide Libenzi
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, see
+ *  <http://www.gnu.org/licenses/>.
+ *
+ *  Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#if !defined(XINCLUDE_H)
+#define XINCLUDE_H
+
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+
+#ifdef _WIN32
+#else
+#include <unistd.h>
+#endif
+
+#include "xmacros.h"
+#include "xdiff.h"
+#include "xtypes.h"
+#include "xutils.h"
+#include "xprepare.h"
+#include "xdiffi.h"
+#include "xemit.h"
+
+#include "common.h"
+
+#endif /* #if !defined(XINCLUDE_H) */

vendor/libgit2-sys/libgit2/src/xdiff/xmacros.h

diff --git a/vendor/libgit2-sys/libgit2/src/xdiff/xmacros.h b/vendor/libgit2-sys/libgit2/src/xdiff/xmacros.h
new file mode 100644
index 0000000..2809a28
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/xdiff/xmacros.h
@@ -0,0 +1,54 @@
+/*
+ *  LibXDiff by Davide Libenzi ( File Differential Library )
+ *  Copyright (C) 2003  Davide Libenzi
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, see
+ *  <http://www.gnu.org/licenses/>.
+ *
+ *  Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#if !defined(XMACROS_H)
+#define XMACROS_H
+
+
+
+
+#define XDL_MIN(a, b) ((a) < (b) ? (a): (b))
+#define XDL_MAX(a, b) ((a) > (b) ? (a): (b))
+#define XDL_ABS(v) ((v) >= 0 ? (v): -(v))
+#define XDL_ISDIGIT(c) ((c) >= '0' && (c) <= '9')
+#define XDL_ISSPACE(c) (isspace((unsigned char)(c)))
+#define XDL_ADDBITS(v,b)	((v) + ((v) >> (b)))
+#define XDL_MASKBITS(b)		((1UL << (b)) - 1)
+#define XDL_HASHLONG(v,b)	(XDL_ADDBITS((unsigned long)(v), b) & XDL_MASKBITS(b))
+#define XDL_PTRFREE(p) do { if (p) { xdl_free(p); (p) = NULL; } } while (0)
+#define XDL_LE32_PUT(p, v) \
+do { \
+	unsigned char *__p = (unsigned char *) (p); \
+	*__p++ = (unsigned char) (v); \
+	*__p++ = (unsigned char) ((v) >> 8); \
+	*__p++ = (unsigned char) ((v) >> 16); \
+	*__p = (unsigned char) ((v) >> 24); \
+} while (0)
+#define XDL_LE32_GET(p, v) \
+do { \
+	unsigned char const *__p = (unsigned char const *) (p); \
+	(v) = (unsigned long) __p[0] | ((unsigned long) __p[1]) << 8 | \
+		((unsigned long) __p[2]) << 16 | ((unsigned long) __p[3]) << 24; \
+} while (0)
+
+
+#endif /* #if !defined(XMACROS_H) */

vendor/libgit2-sys/libgit2/src/xdiff/xmerge.c

diff --git a/vendor/libgit2-sys/libgit2/src/xdiff/xmerge.c b/vendor/libgit2-sys/libgit2/src/xdiff/xmerge.c
new file mode 100644
index 0000000..6fec95a
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/xdiff/xmerge.c
@@ -0,0 +1,738 @@
+/*
+ *  LibXDiff by Davide Libenzi ( File Differential Library )
+ *  Copyright (C) 2003-2006 Davide Libenzi, Johannes E. Schindelin
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, see
+ *  <http://www.gnu.org/licenses/>.
+ *
+ *  Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#include "xinclude.h"
+
+typedef struct s_xdmerge {
+	struct s_xdmerge *next;
+	/*
+	 * 0 = conflict,
+	 * 1 = no conflict, take first,
+	 * 2 = no conflict, take second.
+	 * 3 = no conflict, take both.
+	 */
+	int mode;
+	/*
+	 * These point at the respective postimages.  E.g. <i1,chg1> is
+	 * how side #1 wants to change the common ancestor; if there is no
+	 * overlap, lines before i1 in the postimage of side #1 appear
+	 * in the merge result as a region touched by neither side.
+	 */
+	long i1, i2;
+	long chg1, chg2;
+	/*
+	 * These point at the preimage; of course there is just one
+	 * preimage, that is from the shared common ancestor.
+	 */
+	long i0;
+	long chg0;
+} xdmerge_t;
+
+static int xdl_append_merge(xdmerge_t **merge, int mode,
+			    long i0, long chg0,
+			    long i1, long chg1,
+			    long i2, long chg2)
+{
+	xdmerge_t *m = *merge;
+	if (m && (i1 <= m->i1 + m->chg1 || i2 <= m->i2 + m->chg2)) {
+		if (mode != m->mode)
+			m->mode = 0;
+		m->chg0 = i0 + chg0 - m->i0;
+		m->chg1 = i1 + chg1 - m->i1;
+		m->chg2 = i2 + chg2 - m->i2;
+	} else {
+		m = xdl_malloc(sizeof(xdmerge_t));
+		if (!m)
+			return -1;
+		m->next = NULL;
+		m->mode = mode;
+		m->i0 = i0;
+		m->chg0 = chg0;
+		m->i1 = i1;
+		m->chg1 = chg1;
+		m->i2 = i2;
+		m->chg2 = chg2;
+		if (*merge)
+			(*merge)->next = m;
+		*merge = m;
+	}
+	return 0;
+}
+
+static int xdl_cleanup_merge(xdmerge_t *c)
+{
+	int count = 0;
+	xdmerge_t *next_c;
+
+	/* were there conflicts? */
+	for (; c; c = next_c) {
+		if (c->mode == 0)
+			count++;
+		next_c = c->next;
+		free(c);
+	}
+	return count;
+}
+
+static int xdl_merge_cmp_lines(xdfenv_t *xe1, int i1, xdfenv_t *xe2, int i2,
+		int line_count, long flags)
+{
+	int i;
+	xrecord_t **rec1 = xe1->xdf2.recs + i1;
+	xrecord_t **rec2 = xe2->xdf2.recs + i2;
+
+	for (i = 0; i < line_count; i++) {
+		int result = xdl_recmatch(rec1[i]->ptr, rec1[i]->size,
+			rec2[i]->ptr, rec2[i]->size, flags);
+		if (!result)
+			return -1;
+	}
+	return 0;
+}
+
+static int xdl_recs_copy_0(size_t *out, int use_orig, xdfenv_t *xe, int i, int count, int needs_cr, int add_nl, char *dest)
+{
+	xrecord_t **recs;
+	size_t size = 0;
+
+	*out = 0;
+
+	recs = (use_orig ? xe->xdf1.recs : xe->xdf2.recs) + i;
+
+	if (count < 1)
+		return 0;
+
+	for (i = 0; i < count; ) {
+		if (dest)
+			memcpy(dest + size, recs[i]->ptr, recs[i]->size);
+
+		GITERR_CHECK_ALLOC_ADD(&size, size, recs[i++]->size);
+	}
+
+	if (add_nl) {
+		i = recs[count - 1]->size;
+		if (i == 0 || recs[count - 1]->ptr[i - 1] != '\n') {
+			if (needs_cr) {
+				if (dest)
+					dest[size] = '\r';
+				GITERR_CHECK_ALLOC_ADD(&size, size, 1);
+			}
+
+			if (dest)
+				dest[size] = '\n';
+
+			GITERR_CHECK_ALLOC_ADD(&size, size, 1);
+		}
+	}
+
+	*out = size;
+	return 0;
+}
+
+static int xdl_recs_copy(size_t *out, xdfenv_t *xe, int i, int count, int needs_cr, int add_nl, char *dest)
+{
+	return xdl_recs_copy_0(out, 0, xe, i, count, needs_cr, add_nl, dest);
+}
+
+static int xdl_orig_copy(size_t *out, xdfenv_t *xe, int i, int count, int needs_cr, int add_nl, char *dest)
+{
+	return xdl_recs_copy_0(out, 1, xe, i, count, needs_cr, add_nl, dest);
+}
+
+/*
+ * Returns 1 if the i'th line ends in CR/LF (if it is the last line and
+ * has no eol, the preceding line, if any), 0 if it ends in LF-only, and
+ * -1 if the line ending cannot be determined.
+ */
+static int is_eol_crlf(xdfile_t *file, int i)
+{
+	long size;
+
+	if (i < file->nrec - 1)
+		/* All lines before the last *must* end in LF */
+		return (size = file->recs[i]->size) > 1 &&
+			file->recs[i]->ptr[size - 2] == '\r';
+	if (!file->nrec)
+		/* Cannot determine eol style from empty file */
+		return -1;
+	if ((size = file->recs[i]->size) &&
+			file->recs[i]->ptr[size - 1] == '\n')
+		/* Last line; ends in LF; Is it CR/LF? */
+		return size > 1 &&
+			file->recs[i]->ptr[size - 2] == '\r';
+	if (!i)
+		/* The only line has no eol */
+		return -1;
+	/* Determine eol from second-to-last line */
+	return (size = file->recs[i - 1]->size) > 1 &&
+		file->recs[i - 1]->ptr[size - 2] == '\r';
+}
+
+static int is_cr_needed(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m)
+{
+	int needs_cr;
+
+	/* Match post-images' preceding, or first, lines' end-of-line style */
+	needs_cr = is_eol_crlf(&xe1->xdf2, m->i1 ? m->i1 - 1 : 0);
+	if (needs_cr)
+		needs_cr = is_eol_crlf(&xe2->xdf2, m->i2 ? m->i2 - 1 : 0);
+	/* Look at pre-image's first line, unless we already settled on LF */
+	if (needs_cr)
+		needs_cr = is_eol_crlf(&xe1->xdf1, 0);
+	/* If still undecided, use LF-only */
+	return needs_cr < 0 ? 0 : needs_cr;
+}
+
+static int fill_conflict_hunk(size_t *out, xdfenv_t *xe1, const char *name1,
+			      xdfenv_t *xe2, const char *name2,
+			      const char *name3,
+			      size_t size, int i, int style,
+			      xdmerge_t *m, char *dest, int marker_size)
+{
+	int marker1_size = (name1 ? (int)strlen(name1) + 1 : 0);
+	int marker2_size = (name2 ? (int)strlen(name2) + 1 : 0);
+	int marker3_size = (name3 ? (int)strlen(name3) + 1 : 0);
+	int needs_cr = is_cr_needed(xe1, xe2, m);
+	size_t copied;
+
+	*out = 0;
+
+	if (marker_size <= 0)
+		marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
+
+	/* Before conflicting part */
+	if (xdl_recs_copy(&copied, xe1, i, m->i1 - i, 0, 0,
+			      dest ? dest + size : NULL) < 0)
+		return -1;
+
+	GITERR_CHECK_ALLOC_ADD(&size, size, copied);
+
+	if (!dest) {
+		GITERR_CHECK_ALLOC_ADD5(&size, size, marker_size, 1, needs_cr,  marker1_size);
+	} else {
+		memset(dest + size, '<', marker_size);
+		size += marker_size;
+		if (marker1_size) {
+			dest[size] = ' ';
+			memcpy(dest + size + 1, name1, marker1_size - 1);
+			size += marker1_size;
+		}
+		if (needs_cr)
+			dest[size++] = '\r';
+		dest[size++] = '\n';
+	}
+
+	/* Postimage from side #1 */
+	if (xdl_recs_copy(&copied, xe1, m->i1, m->chg1, needs_cr, 1,
+			      dest ? dest + size : NULL) < 0)
+		return -1;
+
+	GITERR_CHECK_ALLOC_ADD(&size, size, copied);
+
+	if (style == XDL_MERGE_DIFF3) {
+		/* Shared preimage */
+		if (!dest) {
+			GITERR_CHECK_ALLOC_ADD5(&size, size, marker_size, 1, needs_cr, marker3_size);
+		} else {
+			memset(dest + size, '|', marker_size);
+			size += marker_size;
+			if (marker3_size) {
+				dest[size] = ' ';
+				memcpy(dest + size + 1, name3, marker3_size - 1);
+				size += marker3_size;
+			}
+			if (needs_cr)
+				dest[size++] = '\r';
+			dest[size++] = '\n';
+		}
+
+		if (xdl_orig_copy(&copied, xe1, m->i0, m->chg0, needs_cr, 1,
+				      dest ? dest + size : NULL) < 0)
+			return -1;
+		GITERR_CHECK_ALLOC_ADD(&size, size, copied);
+	}
+
+	if (!dest) {
+		GITERR_CHECK_ALLOC_ADD4(&size, size, marker_size, 1, needs_cr);
+	} else {
+		memset(dest + size, '=', marker_size);
+		size += marker_size;
+		if (needs_cr)
+			dest[size++] = '\r';
+		dest[size++] = '\n';
+	}
+
+	/* Postimage from side #2 */
+
+	if (xdl_recs_copy(&copied, xe2, m->i2, m->chg2, needs_cr, 1,
+			      dest ? dest + size : NULL) < 0)
+		return -1;
+	GITERR_CHECK_ALLOC_ADD(&size, size, copied);
+
+	if (!dest) {
+		GITERR_CHECK_ALLOC_ADD5(&size, size, marker_size, 1, needs_cr, marker2_size);
+	} else {
+		memset(dest + size, '>', marker_size);
+		size += marker_size;
+		if (marker2_size) {
+			dest[size] = ' ';
+			memcpy(dest + size + 1, name2, marker2_size - 1);
+			size += marker2_size;
+		}
+		if (needs_cr)
+			dest[size++] = '\r';
+		dest[size++] = '\n';
+	}
+
+	*out = size;
+	return 0;
+}
+
+static int xdl_fill_merge_buffer(size_t *out,
+				 xdfenv_t *xe1, const char *name1,
+				 xdfenv_t *xe2, const char *name2,
+				 const char *ancestor_name,
+				 int favor,
+				 xdmerge_t *m, char *dest, int style,
+				 int marker_size)
+{
+	size_t size, copied;
+	int i;
+
+	*out = 0;
+
+	for (size = i = 0; m; m = m->next) {
+		if (favor && !m->mode)
+			m->mode = favor;
+
+		if (m->mode == 0) {
+			if (fill_conflict_hunk(&size, xe1, name1, xe2, name2,
+						  ancestor_name,
+						  size, i, style, m, dest,
+						  marker_size) < 0)
+				return -1;
+		}
+		else if (m->mode & 3) {
+			/* Before conflicting part */
+			if (xdl_recs_copy(&copied, xe1, i, m->i1 - i, 0, 0,
+					      dest ? dest + size : NULL) < 0)
+				return -1;
+			GITERR_CHECK_ALLOC_ADD(&size, size, copied);
+
+			/* Postimage from side #1 */
+			if (m->mode & 1) {
+				int needs_cr = is_cr_needed(xe1, xe2, m);
+
+				if (xdl_recs_copy(&copied, xe1, m->i1, m->chg1, needs_cr, (m->mode & 2),
+						      dest ? dest + size : NULL) < 0)
+					return -1;
+				GITERR_CHECK_ALLOC_ADD(&size, size, copied);
+			}
+
+			/* Postimage from side #2 */
+			if (m->mode & 2) {
+				if (xdl_recs_copy(&copied, xe2, m->i2, m->chg2, 0, 0,
+						      dest ? dest + size : NULL) < 0)
+					return -1;
+				GITERR_CHECK_ALLOC_ADD(&size, size, copied);
+			}
+		} else
+			continue;
+		i = m->i1 + m->chg1;
+	}
+
+	if (xdl_recs_copy(&copied, xe1, i, xe1->xdf2.nrec - i, 0, 0,
+			      dest ? dest + size : NULL) < 0)
+		return -1;
+	GITERR_CHECK_ALLOC_ADD(&size, size, copied);
+
+	*out = size;
+	return 0;
+}
+
+/*
+ * Sometimes, changes are not quite identical, but differ in only a few
+ * lines. Try hard to show only these few lines as conflicting.
+ */
+static int xdl_refine_conflicts(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m,
+		xpparam_t const *xpp)
+{
+	for (; m; m = m->next) {
+		mmfile_t t1, t2;
+		xdfenv_t xe;
+		xdchange_t *xscr, *x;
+		int i1 = m->i1, i2 = m->i2;
+
+		/* let's handle just the conflicts */
+		if (m->mode)
+			continue;
+
+		/* no sense refining a conflict when one side is empty */
+		if (m->chg1 == 0 || m->chg2 == 0)
+			continue;
+
+		/*
+		 * This probably does not work outside git, since
+		 * we have a very simple mmfile structure.
+		 */
+		t1.ptr = (char *)xe1->xdf2.recs[m->i1]->ptr;
+		t1.size = xe1->xdf2.recs[m->i1 + m->chg1 - 1]->ptr
+			+ xe1->xdf2.recs[m->i1 + m->chg1 - 1]->size - t1.ptr;
+		t2.ptr = (char *)xe2->xdf2.recs[m->i2]->ptr;
+		t2.size = xe2->xdf2.recs[m->i2 + m->chg2 - 1]->ptr
+			+ xe2->xdf2.recs[m->i2 + m->chg2 - 1]->size - t2.ptr;
+		if (xdl_do_diff(&t1, &t2, xpp, &xe) < 0)
+			return -1;
+		if (xdl_change_compact(&xe.xdf1, &xe.xdf2, xpp->flags) < 0 ||
+		    xdl_change_compact(&xe.xdf2, &xe.xdf1, xpp->flags) < 0 ||
+		    xdl_build_script(&xe, &xscr) < 0) {
+			xdl_free_env(&xe);
+			return -1;
+		}
+		if (!xscr) {
+			/* If this happens, the changes are identical. */
+			xdl_free_env(&xe);
+			m->mode = 4;
+			continue;
+		}
+		x = xscr;
+		m->i1 = xscr->i1 + i1;
+		m->chg1 = xscr->chg1;
+		m->i2 = xscr->i2 + i2;
+		m->chg2 = xscr->chg2;
+		while (xscr->next) {
+			xdmerge_t *m2 = xdl_malloc(sizeof(xdmerge_t));
+			if (!m2) {
+				xdl_free_env(&xe);
+				xdl_free_script(x);
+				return -1;
+			}
+			xscr = xscr->next;
+			m2->next = m->next;
+			m->next = m2;
+			m = m2;
+			m->mode = 0;
+			m->i1 = xscr->i1 + i1;
+			m->chg1 = xscr->chg1;
+			m->i2 = xscr->i2 + i2;
+			m->chg2 = xscr->chg2;
+		}
+		xdl_free_env(&xe);
+		xdl_free_script(x);
+	}
+	return 0;
+}
+
+static int line_contains_alnum(const char *ptr, long size)
+{
+	while (size--)
+		if (isalnum((unsigned char)*(ptr++)))
+			return 1;
+	return 0;
+}
+
+static int lines_contain_alnum(xdfenv_t *xe, int i, int chg)
+{
+	for (; chg; chg--, i++)
+		if (line_contains_alnum(xe->xdf2.recs[i]->ptr,
+				xe->xdf2.recs[i]->size))
+			return 1;
+	return 0;
+}
+
+/*
+ * This function merges m and m->next, marking everything between those hunks
+ * as conflicting, too.
+ */
+static void xdl_merge_two_conflicts(xdmerge_t *m)
+{
+	xdmerge_t *next_m = m->next;
+	m->chg1 = next_m->i1 + next_m->chg1 - m->i1;
+	m->chg2 = next_m->i2 + next_m->chg2 - m->i2;
+	m->next = next_m->next;
+	free(next_m);
+}
+
+/*
+ * If there are less than 3 non-conflicting lines between conflicts,
+ * it appears simpler -- because it takes up less (or as many) lines --
+ * if the lines are moved into the conflicts.
+ */
+static int xdl_simplify_non_conflicts(xdfenv_t *xe1, xdmerge_t *m,
+				      int simplify_if_no_alnum)
+{
+	int result = 0;
+
+	if (!m)
+		return result;
+	for (;;) {
+		xdmerge_t *next_m = m->next;
+		int begin, end;
+
+		if (!next_m)
+			return result;
+
+		begin = m->i1 + m->chg1;
+		end = next_m->i1;
+
+		if (m->mode != 0 || next_m->mode != 0 ||
+		    (end - begin > 3 &&
+		     (!simplify_if_no_alnum ||
+		      lines_contain_alnum(xe1, begin, end - begin)))) {
+			m = next_m;
+		} else {
+			result++;
+			xdl_merge_two_conflicts(m);
+		}
+	}
+}
+
+/*
+ * level == 0: mark all overlapping changes as conflict
+ * level == 1: mark overlapping changes as conflict only if not identical
+ * level == 2: analyze non-identical changes for minimal conflict set
+ * level == 3: analyze non-identical changes for minimal conflict set, but
+ *             treat hunks not containing any letter or number as conflicting
+ *
+ * returns < 0 on error, == 0 for no conflicts, else number of conflicts
+ */
+static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1,
+		xdfenv_t *xe2, xdchange_t *xscr2,
+		xmparam_t const *xmp, mmbuffer_t *result)
+{
+	xdmerge_t *changes, *c;
+	xpparam_t const *xpp = &xmp->xpp;
+	const char *const ancestor_name = xmp->ancestor;
+	const char *const name1 = xmp->file1;
+	const char *const name2 = xmp->file2;
+	int i0, i1, i2, chg0, chg1, chg2;
+	int level = xmp->level;
+	int style = xmp->style;
+	int favor = xmp->favor;
+
+	if (style == XDL_MERGE_DIFF3) {
+		/*
+		 * "diff3 -m" output does not make sense for anything
+		 * more aggressive than XDL_MERGE_EAGER.
+		 */
+		if (XDL_MERGE_EAGER < level)
+			level = XDL_MERGE_EAGER;
+	}
+
+	c = changes = NULL;
+
+	while (xscr1 && xscr2) {
+		if (!changes)
+			changes = c;
+		if (xscr1->i1 + xscr1->chg1 < xscr2->i1) {
+			i0 = xscr1->i1;
+			i1 = xscr1->i2;
+			i2 = xscr2->i2 - xscr2->i1 + xscr1->i1;
+			chg0 = xscr1->chg1;
+			chg1 = xscr1->chg2;
+			chg2 = xscr1->chg1;
+			if (xdl_append_merge(&c, 1,
+					     i0, chg0, i1, chg1, i2, chg2)) {
+				xdl_cleanup_merge(changes);
+				return -1;
+			}
+			xscr1 = xscr1->next;
+			continue;
+		}
+		if (xscr2->i1 + xscr2->chg1 < xscr1->i1) {
+			i0 = xscr2->i1;
+			i1 = xscr1->i2 - xscr1->i1 + xscr2->i1;
+			i2 = xscr2->i2;
+			chg0 = xscr2->chg1;
+			chg1 = xscr2->chg1;
+			chg2 = xscr2->chg2;
+			if (xdl_append_merge(&c, 2,
+					     i0, chg0, i1, chg1, i2, chg2)) {
+				xdl_cleanup_merge(changes);
+				return -1;
+			}
+			xscr2 = xscr2->next;
+			continue;
+		}
+		if (level == XDL_MERGE_MINIMAL || xscr1->i1 != xscr2->i1 ||
+				xscr1->chg1 != xscr2->chg1 ||
+				xscr1->chg2 != xscr2->chg2 ||
+				xdl_merge_cmp_lines(xe1, xscr1->i2,
+					xe2, xscr2->i2,
+					xscr1->chg2, xpp->flags)) {
+			/* conflict */
+			int off = xscr1->i1 - xscr2->i1;
+			int ffo = off + xscr1->chg1 - xscr2->chg1;
+
+			i0 = xscr1->i1;
+			i1 = xscr1->i2;
+			i2 = xscr2->i2;
+			if (off > 0) {
+				i0 -= off;
+				i1 -= off;
+			}
+			else
+				i2 += off;
+			chg0 = xscr1->i1 + xscr1->chg1 - i0;
+			chg1 = xscr1->i2 + xscr1->chg2 - i1;
+			chg2 = xscr2->i2 + xscr2->chg2 - i2;
+			if (ffo < 0) {
+				chg0 -= ffo;
+				chg1 -= ffo;
+			} else
+				chg2 += ffo;
+			if (xdl_append_merge(&c, 0,
+					     i0, chg0, i1, chg1, i2, chg2)) {
+				xdl_cleanup_merge(changes);
+				return -1;
+			}
+		}
+
+		i1 = xscr1->i1 + xscr1->chg1;
+		i2 = xscr2->i1 + xscr2->chg1;
+
+		if (i1 >= i2)
+			xscr2 = xscr2->next;
+		if (i2 >= i1)
+			xscr1 = xscr1->next;
+	}
+	while (xscr1) {
+		if (!changes)
+			changes = c;
+		i0 = xscr1->i1;
+		i1 = xscr1->i2;
+		i2 = xscr1->i1 + xe2->xdf2.nrec - xe2->xdf1.nrec;
+		chg0 = xscr1->chg1;
+		chg1 = xscr1->chg2;
+		chg2 = xscr1->chg1;
+		if (xdl_append_merge(&c, 1,
+				     i0, chg0, i1, chg1, i2, chg2)) {
+			xdl_cleanup_merge(changes);
+			return -1;
+		}
+		xscr1 = xscr1->next;
+	}
+	while (xscr2) {
+		if (!changes)
+			changes = c;
+		i0 = xscr2->i1;
+		i1 = xscr2->i1 + xe1->xdf2.nrec - xe1->xdf1.nrec;
+		i2 = xscr2->i2;
+		chg0 = xscr2->chg1;
+		chg1 = xscr2->chg1;
+		chg2 = xscr2->chg2;
+		if (xdl_append_merge(&c, 2,
+				     i0, chg0, i1, chg1, i2, chg2)) {
+			xdl_cleanup_merge(changes);
+			return -1;
+		}
+		xscr2 = xscr2->next;
+	}
+	if (!changes)
+		changes = c;
+	/* refine conflicts */
+	if (XDL_MERGE_ZEALOUS <= level &&
+	    (xdl_refine_conflicts(xe1, xe2, changes, xpp) < 0 ||
+	     xdl_simplify_non_conflicts(xe1, changes,
+					XDL_MERGE_ZEALOUS < level) < 0)) {
+		xdl_cleanup_merge(changes);
+		return -1;
+	}
+	/* output */
+	if (result) {
+		int marker_size = xmp->marker_size;
+		size_t size;
+
+		if (xdl_fill_merge_buffer(&size, xe1, name1, xe2, name2,
+						 ancestor_name,
+						 favor, changes, NULL, style,
+						 marker_size) < 0)
+			return -1;
+
+		result->ptr = xdl_malloc(size);
+		if (!result->ptr) {
+			xdl_cleanup_merge(changes);
+			return -1;
+		}
+		result->size = size;
+		if (xdl_fill_merge_buffer(&size, xe1, name1, xe2, name2,
+				      ancestor_name, favor, changes,
+				      result->ptr, style, marker_size) < 0)
+			return -1;
+	}
+	return xdl_cleanup_merge(changes);
+}
+
+int xdl_merge(mmfile_t *orig, mmfile_t *mf1, mmfile_t *mf2,
+		xmparam_t const *xmp, mmbuffer_t *result)
+{
+	xdchange_t *xscr1, *xscr2;
+	xdfenv_t xe1, xe2;
+	int status;
+	xpparam_t const *xpp = &xmp->xpp;
+
+	result->ptr = NULL;
+	result->size = 0;
+
+	if (xdl_do_diff(orig, mf1, xpp, &xe1) < 0) {
+		return -1;
+	}
+	if (xdl_do_diff(orig, mf2, xpp, &xe2) < 0) {
+		xdl_free_env(&xe1);
+		return -1;
+	}
+	if (xdl_change_compact(&xe1.xdf1, &xe1.xdf2, xpp->flags) < 0 ||
+	    xdl_change_compact(&xe1.xdf2, &xe1.xdf1, xpp->flags) < 0 ||
+	    xdl_build_script(&xe1, &xscr1) < 0) {
+		xdl_free_env(&xe1);
+		return -1;
+	}
+	if (xdl_change_compact(&xe2.xdf1, &xe2.xdf2, xpp->flags) < 0 ||
+	    xdl_change_compact(&xe2.xdf2, &xe2.xdf1, xpp->flags) < 0 ||
+	    xdl_build_script(&xe2, &xscr2) < 0) {
+		xdl_free_script(xscr1);
+		xdl_free_env(&xe1);
+		xdl_free_env(&xe2);
+		return -1;
+	}
+	status = 0;
+	if (!xscr1) {
+		result->ptr = xdl_malloc(mf2->size);
+		memcpy(result->ptr, mf2->ptr, mf2->size);
+		result->size = mf2->size;
+	} else if (!xscr2) {
+		result->ptr = xdl_malloc(mf1->size);
+		memcpy(result->ptr, mf1->ptr, mf1->size);
+		result->size = mf1->size;
+	} else {
+		status = xdl_do_merge(&xe1, xscr1,
+				      &xe2, xscr2,
+				      xmp, result);
+	}
+	xdl_free_script(xscr1);
+	xdl_free_script(xscr2);
+
+	xdl_free_env(&xe1);
+	xdl_free_env(&xe2);
+
+	return status;
+}

vendor/libgit2-sys/libgit2/src/xdiff/xpatience.c

diff --git a/vendor/libgit2-sys/libgit2/src/xdiff/xpatience.c b/vendor/libgit2-sys/libgit2/src/xdiff/xpatience.c
new file mode 100644
index 0000000..cedf39c
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/xdiff/xpatience.c
@@ -0,0 +1,390 @@
+/*
+ *  LibXDiff by Davide Libenzi ( File Differential Library )
+ *  Copyright (C) 2003-2016 Davide Libenzi, Johannes E. Schindelin
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, see
+ *  <http://www.gnu.org/licenses/>.
+ *
+ *  Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+#include "xinclude.h"
+#include "xtypes.h"
+#include "xdiff.h"
+
+/*
+ * The basic idea of patience diff is to find lines that are unique in
+ * both files.  These are intuitively the ones that we want to see as
+ * common lines.
+ *
+ * The maximal ordered sequence of such line pairs (where ordered means
+ * that the order in the sequence agrees with the order of the lines in
+ * both files) naturally defines an initial set of common lines.
+ *
+ * Now, the algorithm tries to extend the set of common lines by growing
+ * the line ranges where the files have identical lines.
+ *
+ * Between those common lines, the patience diff algorithm is applied
+ * recursively, until no unique line pairs can be found; these line ranges
+ * are handled by the well-known Myers algorithm.
+ */
+
+#define NON_UNIQUE ULONG_MAX
+
+/*
+ * This is a hash mapping from line hash to line numbers in the first and
+ * second file.
+ */
+struct hashmap {
+	int nr, alloc;
+	struct entry {
+		unsigned long hash;
+		/*
+		 * 0 = unused entry, 1 = first line, 2 = second, etc.
+		 * line2 is NON_UNIQUE if the line is not unique
+		 * in either the first or the second file.
+		 */
+		unsigned long line1, line2;
+		/*
+		 * "next" & "previous" are used for the longest common
+		 * sequence;
+		 * initially, "next" reflects only the order in file1.
+		 */
+		struct entry *next, *previous;
+
+		/*
+		 * If 1, this entry can serve as an anchor. See
+		 * Documentation/diff-options.txt for more information.
+		 */
+		unsigned anchor : 1;
+	} *entries, *first, *last;
+	/* were common records found? */
+	unsigned long has_matches;
+	mmfile_t *file1, *file2;
+	xdfenv_t *env;
+	xpparam_t const *xpp;
+};
+
+static int is_anchor(xpparam_t const *xpp, const char *line)
+{
+	unsigned long i;
+	for (i = 0; i < xpp->anchors_nr; i++) {
+		if (!strncmp(line, xpp->anchors[i], strlen(xpp->anchors[i])))
+			return 1;
+	}
+	return 0;
+}
+
+/* The argument "pass" is 1 for the first file, 2 for the second. */
+static void insert_record(xpparam_t const *xpp, int line, struct hashmap *map,
+			  int pass)
+{
+	xrecord_t **records = pass == 1 ?
+		map->env->xdf1.recs : map->env->xdf2.recs;
+	xrecord_t *record = records[line - 1], *other;
+	/*
+	 * After xdl_prepare_env() (or more precisely, due to
+	 * xdl_classify_record()), the "ha" member of the records (AKA lines)
+	 * is _not_ the hash anymore, but a linearized version of it.  In
+	 * other words, the "ha" member is guaranteed to start with 0 and
+	 * the second record's ha can only be 0 or 1, etc.
+	 *
+	 * So we multiply ha by 2 in the hope that the hashing was
+	 * "unique enough".
+	 */
+	int index = (int)((record->ha << 1) % map->alloc);
+
+	while (map->entries[index].line1) {
+		other = map->env->xdf1.recs[map->entries[index].line1 - 1];
+		if (map->entries[index].hash != record->ha ||
+				!xdl_recmatch(record->ptr, record->size,
+					other->ptr, other->size,
+					map->xpp->flags)) {
+			if (++index >= map->alloc)
+				index = 0;
+			continue;
+		}
+		if (pass == 2)
+			map->has_matches = 1;
+		if (pass == 1 || map->entries[index].line2)
+			map->entries[index].line2 = NON_UNIQUE;
+		else
+			map->entries[index].line2 = line;
+		return;
+	}
+	if (pass == 2)
+		return;
+	map->entries[index].line1 = line;
+	map->entries[index].hash = record->ha;
+	map->entries[index].anchor = is_anchor(xpp, map->env->xdf1.recs[line - 1]->ptr);
+	if (!map->first)
+		map->first = map->entries + index;
+	if (map->last) {
+		map->last->next = map->entries + index;
+		map->entries[index].previous = map->last;
+	}
+	map->last = map->entries + index;
+	map->nr++;
+}
+
+/*
+ * This function has to be called for each recursion into the inter-hunk
+ * parts, as previously non-unique lines can become unique when being
+ * restricted to a smaller part of the files.
+ *
+ * It is assumed that env has been prepared using xdl_prepare().
+ */
+static int fill_hashmap(mmfile_t *file1, mmfile_t *file2,
+		xpparam_t const *xpp, xdfenv_t *env,
+		struct hashmap *result,
+		int line1, int count1, int line2, int count2)
+{
+	result->file1 = file1;
+	result->file2 = file2;
+	result->xpp = xpp;
+	result->env = env;
+
+	/* We know exactly how large we want the hash map */
+	result->alloc = count1 * 2;
+	result->entries = (struct entry *)
+		xdl_malloc(result->alloc * sizeof(struct entry));
+	if (!result->entries)
+		return -1;
+	memset(result->entries, 0, result->alloc * sizeof(struct entry));
+
+	/* First, fill with entries from the first file */
+	while (count1--)
+		insert_record(xpp, line1++, result, 1);
+
+	/* Then search for matches in the second file */
+	while (count2--)
+		insert_record(xpp, line2++, result, 2);
+
+	return 0;
+}
+
+/*
+ * Find the longest sequence with a smaller last element (meaning a smaller
+ * line2, as we construct the sequence with entries ordered by line1).
+ */
+static int binary_search(struct entry **sequence, int longest,
+		struct entry *entry)
+{
+	int left = -1, right = longest;
+
+	while (left + 1 < right) {
+		int middle = left + (right - left) / 2;
+		/* by construction, no two entries can be equal */
+		if (sequence[middle]->line2 > entry->line2)
+			right = middle;
+		else
+			left = middle;
+	}
+	/* return the index in "sequence", _not_ the sequence length */
+	return left;
+}
+
+/*
+ * The idea is to start with the list of common unique lines sorted by
+ * the order in file1.  For each of these pairs, the longest (partial)
+ * sequence whose last element's line2 is smaller is determined.
+ *
+ * For efficiency, the sequences are kept in a list containing exactly one
+ * item per sequence length: the sequence with the smallest last
+ * element (in terms of line2).
+ */
+static struct entry *find_longest_common_sequence(struct hashmap *map)
+{
+	struct entry **sequence = xdl_malloc(map->nr * sizeof(struct entry *));
+	int longest = 0, i;
+	struct entry *entry;
+
+	/*
+	 * If not -1, this entry in sequence must never be overridden.
+	 * Therefore, overriding entries before this has no effect, so
+	 * do not do that either.
+	 */
+	int anchor_i = -1;
+
+	for (entry = map->first; entry; entry = entry->next) {
+		if (!entry->line2 || entry->line2 == NON_UNIQUE)
+			continue;
+		i = binary_search(sequence, longest, entry);
+		entry->previous = i < 0 ? NULL : sequence[i];
+		++i;
+		if (i <= anchor_i)
+			continue;
+		sequence[i] = entry;
+		if (entry->anchor) {
+			anchor_i = i;
+			longest = anchor_i + 1;
+		} else if (i == longest) {
+			longest++;
+		}
+	}
+
+	/* No common unique lines were found */
+	if (!longest) {
+		xdl_free(sequence);
+		return NULL;
+	}
+
+	/* Iterate starting at the last element, adjusting the "next" members */
+	entry = sequence[longest - 1];
+	entry->next = NULL;
+	while (entry->previous) {
+		entry->previous->next = entry;
+		entry = entry->previous;
+	}
+	xdl_free(sequence);
+	return entry;
+}
+
+static int match(struct hashmap *map, int line1, int line2)
+{
+	xrecord_t *record1 = map->env->xdf1.recs[line1 - 1];
+	xrecord_t *record2 = map->env->xdf2.recs[line2 - 1];
+	return xdl_recmatch(record1->ptr, record1->size,
+		record2->ptr, record2->size, map->xpp->flags);
+}
+
+static int patience_diff(mmfile_t *file1, mmfile_t *file2,
+		xpparam_t const *xpp, xdfenv_t *env,
+		int line1, int count1, int line2, int count2);
+
+static int walk_common_sequence(struct hashmap *map, struct entry *first,
+		int line1, int count1, int line2, int count2)
+{
+	int end1 = line1 + count1, end2 = line2 + count2;
+	int next1, next2;
+
+	for (;;) {
+		/* Try to grow the line ranges of common lines */
+		if (first) {
+			next1 = first->line1;
+			next2 = first->line2;
+			while (next1 > line1 && next2 > line2 &&
+					match(map, next1 - 1, next2 - 1)) {
+				next1--;
+				next2--;
+			}
+		} else {
+			next1 = end1;
+			next2 = end2;
+		}
+		while (line1 < next1 && line2 < next2 &&
+				match(map, line1, line2)) {
+			line1++;
+			line2++;
+		}
+
+		/* Recurse */
+		if (next1 > line1 || next2 > line2) {
+			struct hashmap submap;
+
+			memset(&submap, 0, sizeof(submap));
+			if (patience_diff(map->file1, map->file2,
+					map->xpp, map->env,
+					line1, next1 - line1,
+					line2, next2 - line2))
+				return -1;
+		}
+
+		if (!first)
+			return 0;
+
+		while (first->next &&
+				first->next->line1 == first->line1 + 1 &&
+				first->next->line2 == first->line2 + 1)
+			first = first->next;
+
+		line1 = first->line1 + 1;
+		line2 = first->line2 + 1;
+
+		first = first->next;
+	}
+}
+
+static int fall_back_to_classic_diff(struct hashmap *map,
+		int line1, int count1, int line2, int count2)
+{
+	xpparam_t xpp;
+	xpp.flags = map->xpp->flags & ~XDF_DIFF_ALGORITHM_MASK;
+
+	return xdl_fall_back_diff(map->env, &xpp,
+				  line1, count1, line2, count2);
+}
+
+/*
+ * Recursively find the longest common sequence of unique lines,
+ * and if none was found, ask xdl_do_diff() to do the job.
+ *
+ * This function assumes that env was prepared with xdl_prepare_env().
+ */
+static int patience_diff(mmfile_t *file1, mmfile_t *file2,
+		xpparam_t const *xpp, xdfenv_t *env,
+		int line1, int count1, int line2, int count2)
+{
+	struct hashmap map;
+	struct entry *first;
+	int result = 0;
+
+	/* trivial case: one side is empty */
+	if (!count1) {
+		while(count2--)
+			env->xdf2.rchg[line2++ - 1] = 1;
+		return 0;
+	} else if (!count2) {
+		while(count1--)
+			env->xdf1.rchg[line1++ - 1] = 1;
+		return 0;
+	}
+
+	memset(&map, 0, sizeof(map));
+	if (fill_hashmap(file1, file2, xpp, env, &map,
+			line1, count1, line2, count2))
+		return -1;
+
+	/* are there any matching lines at all? */
+	if (!map.has_matches) {
+		while(count1--)
+			env->xdf1.rchg[line1++ - 1] = 1;
+		while(count2--)
+			env->xdf2.rchg[line2++ - 1] = 1;
+		xdl_free(map.entries);
+		return 0;
+	}
+
+	first = find_longest_common_sequence(&map);
+	if (first)
+		result = walk_common_sequence(&map, first,
+			line1, count1, line2, count2);
+	else
+		result = fall_back_to_classic_diff(&map,
+			line1, count1, line2, count2);
+
+	xdl_free(map.entries);
+	return result;
+}
+
+int xdl_do_patience_diff(mmfile_t *file1, mmfile_t *file2,
+		xpparam_t const *xpp, xdfenv_t *env)
+{
+	if (xdl_prepare_env(file1, file2, xpp, env) < 0)
+		return -1;
+
+	/* environment is cleaned up in xdl_diff() */
+	return patience_diff(file1, file2, xpp, env,
+			1, env->xdf1.nrec, 1, env->xdf2.nrec);
+}

vendor/libgit2-sys/libgit2/src/xdiff/xprepare.c

diff --git a/vendor/libgit2-sys/libgit2/src/xdiff/xprepare.c b/vendor/libgit2-sys/libgit2/src/xdiff/xprepare.c
new file mode 100644
index 0000000..abeb8fb
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/xdiff/xprepare.c
@@ -0,0 +1,483 @@
+/*
+ *  LibXDiff by Davide Libenzi ( File Differential Library )
+ *  Copyright (C) 2003  Davide Libenzi
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, see
+ *  <http://www.gnu.org/licenses/>.
+ *
+ *  Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#include "xinclude.h"
+
+
+#define XDL_KPDIS_RUN 4
+#define XDL_MAX_EQLIMIT 1024
+#define XDL_SIMSCAN_WINDOW 100
+#define XDL_GUESS_NLINES1 256
+#define XDL_GUESS_NLINES2 20
+
+
+typedef struct s_xdlclass {
+	struct s_xdlclass *next;
+	unsigned long ha;
+	char const *line;
+	long size;
+	long idx;
+	long len1, len2;
+} xdlclass_t;
+
+typedef struct s_xdlclassifier {
+	unsigned int hbits;
+	long hsize;
+	xdlclass_t **rchash;
+	chastore_t ncha;
+	xdlclass_t **rcrecs;
+	long alloc;
+	long count;
+	long flags;
+} xdlclassifier_t;
+
+
+
+
+static int xdl_init_classifier(xdlclassifier_t *cf, long size, long flags);
+static void xdl_free_classifier(xdlclassifier_t *cf);
+static int xdl_classify_record(unsigned int pass, xdlclassifier_t *cf, xrecord_t **rhash,
+			       unsigned int hbits, xrecord_t *rec);
+static int xdl_prepare_ctx(unsigned int pass, mmfile_t *mf, long narec, xpparam_t const *xpp,
+			   xdlclassifier_t *cf, xdfile_t *xdf);
+static void xdl_free_ctx(xdfile_t *xdf);
+static int xdl_clean_mmatch(char const *dis, long i, long s, long e);
+static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2);
+static int xdl_trim_ends(xdfile_t *xdf1, xdfile_t *xdf2);
+static int xdl_optimize_ctxs(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2);
+
+
+
+
+static int xdl_init_classifier(xdlclassifier_t *cf, long size, long flags) {
+	cf->flags = flags;
+
+	cf->hbits = xdl_hashbits((unsigned int) size);
+	cf->hsize = 1 << cf->hbits;
+
+	if (xdl_cha_init(&cf->ncha, sizeof(xdlclass_t), size / 4 + 1) < 0) {
+
+		return -1;
+	}
+	if (!(cf->rchash = (xdlclass_t **) xdl_malloc(cf->hsize * sizeof(xdlclass_t *)))) {
+
+		xdl_cha_free(&cf->ncha);
+		return -1;
+	}
+	memset(cf->rchash, 0, cf->hsize * sizeof(xdlclass_t *));
+
+	cf->alloc = size;
+	if (!(cf->rcrecs = (xdlclass_t **) xdl_malloc(cf->alloc * sizeof(xdlclass_t *)))) {
+
+		xdl_free(cf->rchash);
+		xdl_cha_free(&cf->ncha);
+		return -1;
+	}
+
+	cf->count = 0;
+
+	return 0;
+}
+
+
+static void xdl_free_classifier(xdlclassifier_t *cf) {
+
+	xdl_free(cf->rcrecs);
+	xdl_free(cf->rchash);
+	xdl_cha_free(&cf->ncha);
+}
+
+
+static int xdl_classify_record(unsigned int pass, xdlclassifier_t *cf, xrecord_t **rhash,
+			       unsigned int hbits, xrecord_t *rec) {
+	long hi;
+	char const *line;
+	xdlclass_t *rcrec;
+	xdlclass_t **rcrecs;
+
+	line = rec->ptr;
+	hi = (long) XDL_HASHLONG(rec->ha, cf->hbits);
+	for (rcrec = cf->rchash[hi]; rcrec; rcrec = rcrec->next)
+		if (rcrec->ha == rec->ha &&
+				xdl_recmatch(rcrec->line, rcrec->size,
+					rec->ptr, rec->size, cf->flags))
+			break;
+
+	if (!rcrec) {
+		if (!(rcrec = xdl_cha_alloc(&cf->ncha))) {
+
+			return -1;
+		}
+		rcrec->idx = cf->count++;
+		if (cf->count > cf->alloc) {
+			cf->alloc *= 2;
+			if (!(rcrecs = (xdlclass_t **) xdl_realloc(cf->rcrecs, cf->alloc * sizeof(xdlclass_t *)))) {
+
+				return -1;
+			}
+			cf->rcrecs = rcrecs;
+		}
+		cf->rcrecs[rcrec->idx] = rcrec;
+		rcrec->line = line;
+		rcrec->size = rec->size;
+		rcrec->ha = rec->ha;
+		rcrec->len1 = rcrec->len2 = 0;
+		rcrec->next = cf->rchash[hi];
+		cf->rchash[hi] = rcrec;
+	}
+
+	(pass == 1) ? rcrec->len1++ : rcrec->len2++;
+
+	rec->ha = (unsigned long) rcrec->idx;
+
+	hi = (long) XDL_HASHLONG(rec->ha, hbits);
+	rec->next = rhash[hi];
+	rhash[hi] = rec;
+
+	return 0;
+}
+
+
+static int xdl_prepare_ctx(unsigned int pass, mmfile_t *mf, long narec, xpparam_t const *xpp,
+			   xdlclassifier_t *cf, xdfile_t *xdf) {
+	unsigned int hbits;
+	long nrec, hsize, bsize;
+	unsigned long hav;
+	char const *blk, *cur, *top, *prev;
+	xrecord_t *crec;
+	xrecord_t **recs, **rrecs;
+	xrecord_t **rhash;
+	unsigned long *ha;
+	char *rchg;
+	long *rindex;
+
+	ha = NULL;
+	rindex = NULL;
+	rchg = NULL;
+	rhash = NULL;
+	recs = NULL;
+
+	if (xdl_cha_init(&xdf->rcha, sizeof(xrecord_t), narec / 4 + 1) < 0)
+		goto abort;
+	if (!(recs = (xrecord_t **) xdl_malloc(narec * sizeof(xrecord_t *))))
+		goto abort;
+
+	if (XDF_DIFF_ALG(xpp->flags) == XDF_HISTOGRAM_DIFF)
+		hbits = hsize = 0;
+	else {
+		hbits = xdl_hashbits((unsigned int) narec);
+		hsize = 1 << hbits;
+		if (!(rhash = (xrecord_t **) xdl_malloc(hsize * sizeof(xrecord_t *))))
+			goto abort;
+		memset(rhash, 0, hsize * sizeof(xrecord_t *));
+	}
+
+	nrec = 0;
+	if ((cur = blk = xdl_mmfile_first(mf, &bsize)) != NULL) {
+		for (top = blk + bsize; cur < top; ) {
+			prev = cur;
+			hav = xdl_hash_record(&cur, top, xpp->flags);
+			if (nrec >= narec) {
+				narec *= 2;
+				if (!(rrecs = (xrecord_t **) xdl_realloc(recs, narec * sizeof(xrecord_t *))))
+					goto abort;
+				recs = rrecs;
+			}
+			if (!(crec = xdl_cha_alloc(&xdf->rcha)))
+				goto abort;
+			crec->ptr = prev;
+			crec->size = (long) (cur - prev);
+			crec->ha = hav;
+			recs[nrec++] = crec;
+
+			if ((XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF) &&
+			    xdl_classify_record(pass, cf, rhash, hbits, crec) < 0)
+				goto abort;
+		}
+	}
+
+	if (!(rchg = (char *) xdl_malloc((nrec + 2) * sizeof(char))))
+		goto abort;
+	memset(rchg, 0, (nrec + 2) * sizeof(char));
+
+	if (!(rindex = (long *) xdl_malloc((nrec + 1) * sizeof(long))))
+		goto abort;
+	if (!(ha = (unsigned long *) xdl_malloc((nrec + 1) * sizeof(unsigned long))))
+		goto abort;
+
+	xdf->nrec = nrec;
+	xdf->recs = recs;
+	xdf->hbits = hbits;
+	xdf->rhash = rhash;
+	xdf->rchg = rchg + 1;
+	xdf->rindex = rindex;
+	xdf->nreff = 0;
+	xdf->ha = ha;
+	xdf->dstart = 0;
+	xdf->dend = nrec - 1;
+
+	return 0;
+
+abort:
+	xdl_free(ha);
+	xdl_free(rindex);
+	xdl_free(rchg);
+	xdl_free(rhash);
+	xdl_free(recs);
+	xdl_cha_free(&xdf->rcha);
+	return -1;
+}
+
+
+static void xdl_free_ctx(xdfile_t *xdf) {
+
+	xdl_free(xdf->rhash);
+	xdl_free(xdf->rindex);
+	xdl_free(xdf->rchg - 1);
+	xdl_free(xdf->ha);
+	xdl_free(xdf->recs);
+	xdl_cha_free(&xdf->rcha);
+}
+
+
+int xdl_prepare_env(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+		    xdfenv_t *xe) {
+	long enl1, enl2, sample;
+	xdlclassifier_t cf;
+
+	memset(&cf, 0, sizeof(cf));
+
+	/*
+	 * For histogram diff, we can afford a smaller sample size and
+	 * thus a poorer estimate of the number of lines, as the hash
+	 * table (rhash) won't be filled up/grown. The number of lines
+	 * (nrecs) will be updated correctly anyway by
+	 * xdl_prepare_ctx().
+	 */
+	sample = (XDF_DIFF_ALG(xpp->flags) == XDF_HISTOGRAM_DIFF
+		  ? XDL_GUESS_NLINES2 : XDL_GUESS_NLINES1);
+
+	enl1 = xdl_guess_lines(mf1, sample) + 1;
+	enl2 = xdl_guess_lines(mf2, sample) + 1;
+
+	if (XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF &&
+	    xdl_init_classifier(&cf, enl1 + enl2 + 1, xpp->flags) < 0)
+		return -1;
+
+	if (xdl_prepare_ctx(1, mf1, enl1, xpp, &cf, &xe->xdf1) < 0) {
+
+		xdl_free_classifier(&cf);
+		return -1;
+	}
+	if (xdl_prepare_ctx(2, mf2, enl2, xpp, &cf, &xe->xdf2) < 0) {
+
+		xdl_free_ctx(&xe->xdf1);
+		xdl_free_classifier(&cf);
+		return -1;
+	}
+
+	if ((XDF_DIFF_ALG(xpp->flags) != XDF_PATIENCE_DIFF) &&
+	    (XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF) &&
+	    xdl_optimize_ctxs(&cf, &xe->xdf1, &xe->xdf2) < 0) {
+
+		xdl_free_ctx(&xe->xdf2);
+		xdl_free_ctx(&xe->xdf1);
+		xdl_free_classifier(&cf);
+		return -1;
+	}
+
+	if (XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF)
+		xdl_free_classifier(&cf);
+
+	return 0;
+}
+
+
+void xdl_free_env(xdfenv_t *xe) {
+
+	xdl_free_ctx(&xe->xdf2);
+	xdl_free_ctx(&xe->xdf1);
+}
+
+
+static int xdl_clean_mmatch(char const *dis, long i, long s, long e) {
+	long r, rdis0, rpdis0, rdis1, rpdis1;
+
+	/*
+	 * Limits the window the is examined during the similar-lines
+	 * scan. The loops below stops when dis[i - r] == 1 (line that
+	 * has no match), but there are corner cases where the loop
+	 * proceed all the way to the extremities by causing huge
+	 * performance penalties in case of big files.
+	 */
+	if (i - s > XDL_SIMSCAN_WINDOW)
+		s = i - XDL_SIMSCAN_WINDOW;
+	if (e - i > XDL_SIMSCAN_WINDOW)
+		e = i + XDL_SIMSCAN_WINDOW;
+
+	/*
+	 * Scans the lines before 'i' to find a run of lines that either
+	 * have no match (dis[j] == 0) or have multiple matches (dis[j] > 1).
+	 * Note that we always call this function with dis[i] > 1, so the
+	 * current line (i) is already a multimatch line.
+	 */
+	for (r = 1, rdis0 = 0, rpdis0 = 1; (i - r) >= s; r++) {
+		if (!dis[i - r])
+			rdis0++;
+		else if (dis[i - r] == 2)
+			rpdis0++;
+		else
+			break;
+	}
+	/*
+	 * If the run before the line 'i' found only multimatch lines, we
+	 * return 0 and hence we don't make the current line (i) discarded.
+	 * We want to discard multimatch lines only when they appear in the
+	 * middle of runs with nomatch lines (dis[j] == 0).
+	 */
+	if (rdis0 == 0)
+		return 0;
+	for (r = 1, rdis1 = 0, rpdis1 = 1; (i + r) <= e; r++) {
+		if (!dis[i + r])
+			rdis1++;
+		else if (dis[i + r] == 2)
+			rpdis1++;
+		else
+			break;
+	}
+	/*
+	 * If the run after the line 'i' found only multimatch lines, we
+	 * return 0 and hence we don't make the current line (i) discarded.
+	 */
+	if (rdis1 == 0)
+		return 0;
+	rdis1 += rdis0;
+	rpdis1 += rpdis0;
+
+	return rpdis1 * XDL_KPDIS_RUN < (rpdis1 + rdis1);
+}
+
+
+/*
+ * Try to reduce the problem complexity, discard records that have no
+ * matches on the other file. Also, lines that have multiple matches
+ * might be potentially discarded if they happear in a run of discardable.
+ */
+static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2) {
+	long i, nm, nreff, mlim;
+	xrecord_t **recs;
+	xdlclass_t *rcrec;
+	char *dis, *dis1, *dis2;
+
+	if (!(dis = (char *) xdl_malloc(xdf1->nrec + xdf2->nrec + 2))) {
+
+		return -1;
+	}
+	memset(dis, 0, xdf1->nrec + xdf2->nrec + 2);
+	dis1 = dis;
+	dis2 = dis1 + xdf1->nrec + 1;
+
+	if ((mlim = xdl_bogosqrt(xdf1->nrec)) > XDL_MAX_EQLIMIT)
+		mlim = XDL_MAX_EQLIMIT;
+	for (i = xdf1->dstart, recs = &xdf1->recs[xdf1->dstart]; i <= xdf1->dend; i++, recs++) {
+		rcrec = cf->rcrecs[(*recs)->ha];
+		nm = rcrec ? rcrec->len2 : 0;
+		dis1[i] = (nm == 0) ? 0: (nm >= mlim) ? 2: 1;
+	}
+
+	if ((mlim = xdl_bogosqrt(xdf2->nrec)) > XDL_MAX_EQLIMIT)
+		mlim = XDL_MAX_EQLIMIT;
+	for (i = xdf2->dstart, recs = &xdf2->recs[xdf2->dstart]; i <= xdf2->dend; i++, recs++) {
+		rcrec = cf->rcrecs[(*recs)->ha];
+		nm = rcrec ? rcrec->len1 : 0;
+		dis2[i] = (nm == 0) ? 0: (nm >= mlim) ? 2: 1;
+	}
+
+	for (nreff = 0, i = xdf1->dstart, recs = &xdf1->recs[xdf1->dstart];
+	     i <= xdf1->dend; i++, recs++) {
+		if (dis1[i] == 1 ||
+		    (dis1[i] == 2 && !xdl_clean_mmatch(dis1, i, xdf1->dstart, xdf1->dend))) {
+			xdf1->rindex[nreff] = i;
+			xdf1->ha[nreff] = (*recs)->ha;
+			nreff++;
+		} else
+			xdf1->rchg[i] = 1;
+	}
+	xdf1->nreff = nreff;
+
+	for (nreff = 0, i = xdf2->dstart, recs = &xdf2->recs[xdf2->dstart];
+	     i <= xdf2->dend; i++, recs++) {
+		if (dis2[i] == 1 ||
+		    (dis2[i] == 2 && !xdl_clean_mmatch(dis2, i, xdf2->dstart, xdf2->dend))) {
+			xdf2->rindex[nreff] = i;
+			xdf2->ha[nreff] = (*recs)->ha;
+			nreff++;
+		} else
+			xdf2->rchg[i] = 1;
+	}
+	xdf2->nreff = nreff;
+
+	xdl_free(dis);
+
+	return 0;
+}
+
+
+/*
+ * Early trim initial and terminal matching records.
+ */
+static int xdl_trim_ends(xdfile_t *xdf1, xdfile_t *xdf2) {
+	long i, lim;
+	xrecord_t **recs1, **recs2;
+
+	recs1 = xdf1->recs;
+	recs2 = xdf2->recs;
+	for (i = 0, lim = XDL_MIN(xdf1->nrec, xdf2->nrec); i < lim;
+	     i++, recs1++, recs2++)
+		if ((*recs1)->ha != (*recs2)->ha)
+			break;
+
+	xdf1->dstart = xdf2->dstart = i;
+
+	recs1 = xdf1->recs + xdf1->nrec - 1;
+	recs2 = xdf2->recs + xdf2->nrec - 1;
+	for (lim -= i, i = 0; i < lim; i++, recs1--, recs2--)
+		if ((*recs1)->ha != (*recs2)->ha)
+			break;
+
+	xdf1->dend = xdf1->nrec - i - 1;
+	xdf2->dend = xdf2->nrec - i - 1;
+
+	return 0;
+}
+
+
+static int xdl_optimize_ctxs(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2) {
+
+	if (xdl_trim_ends(xdf1, xdf2) < 0 ||
+	    xdl_cleanup_records(cf, xdf1, xdf2) < 0) {
+
+		return -1;
+	}
+
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/xdiff/xprepare.h

diff --git a/vendor/libgit2-sys/libgit2/src/xdiff/xprepare.h b/vendor/libgit2-sys/libgit2/src/xdiff/xprepare.h
new file mode 100644
index 0000000..947d9fc
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/xdiff/xprepare.h
@@ -0,0 +1,34 @@
+/*
+ *  LibXDiff by Davide Libenzi ( File Differential Library )
+ *  Copyright (C) 2003  Davide Libenzi
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, see
+ *  <http://www.gnu.org/licenses/>.
+ *
+ *  Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#if !defined(XPREPARE_H)
+#define XPREPARE_H
+
+
+
+int xdl_prepare_env(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+		    xdfenv_t *xe);
+void xdl_free_env(xdfenv_t *xe);
+
+
+
+#endif /* #if !defined(XPREPARE_H) */

vendor/libgit2-sys/libgit2/src/xdiff/xtypes.h

diff --git a/vendor/libgit2-sys/libgit2/src/xdiff/xtypes.h b/vendor/libgit2-sys/libgit2/src/xdiff/xtypes.h
new file mode 100644
index 0000000..8442bd4
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/xdiff/xtypes.h
@@ -0,0 +1,67 @@
+/*
+ *  LibXDiff by Davide Libenzi ( File Differential Library )
+ *  Copyright (C) 2003  Davide Libenzi
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, see
+ *  <http://www.gnu.org/licenses/>.
+ *
+ *  Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#if !defined(XTYPES_H)
+#define XTYPES_H
+
+
+
+typedef struct s_chanode {
+	struct s_chanode *next;
+	long icurr;
+} chanode_t;
+
+typedef struct s_chastore {
+	chanode_t *head, *tail;
+	long isize, nsize;
+	chanode_t *ancur;
+	chanode_t *sncur;
+	long scurr;
+} chastore_t;
+
+typedef struct s_xrecord {
+	struct s_xrecord *next;
+	char const *ptr;
+	long size;
+	unsigned long ha;
+} xrecord_t;
+
+typedef struct s_xdfile {
+	chastore_t rcha;
+	long nrec;
+	unsigned int hbits;
+	xrecord_t **rhash;
+	long dstart, dend;
+	xrecord_t **recs;
+	char *rchg;
+	long *rindex;
+	long nreff;
+	unsigned long *ha;
+} xdfile_t;
+
+typedef struct s_xdfenv {
+	xdfile_t xdf1, xdf2;
+} xdfenv_t;
+
+
+
+#endif /* #if !defined(XTYPES_H) */

vendor/libgit2-sys/libgit2/src/xdiff/xutils.c

diff --git a/vendor/libgit2-sys/libgit2/src/xdiff/xutils.c b/vendor/libgit2-sys/libgit2/src/xdiff/xutils.c
new file mode 100644
index 0000000..17c9ae1
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/xdiff/xutils.c
@@ -0,0 +1,423 @@
+/*
+ *  LibXDiff by Davide Libenzi ( File Differential Library )
+ *  Copyright (C) 2003	Davide Libenzi
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, see
+ *  <http://www.gnu.org/licenses/>.
+ *
+ *  Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#include "xinclude.h"
+
+
+
+
+long xdl_bogosqrt(long n) {
+	long i;
+
+	/*
+	 * Classical integer square root approximation using shifts.
+	 */
+	for (i = 1; n > 0; n >>= 2)
+		i <<= 1;
+
+	return i;
+}
+
+
+int xdl_emit_diffrec(char const *rec, long size, char const *pre, long psize,
+		     xdemitcb_t *ecb) {
+	int i = 2;
+	mmbuffer_t mb[3];
+
+	mb[0].ptr = (char *) pre;
+	mb[0].size = psize;
+	mb[1].ptr = (char *) rec;
+	mb[1].size = size;
+	if (size > 0 && rec[size - 1] != '\n') {
+		mb[2].ptr = (char *) "\n\\ No newline at end of file\n";
+		mb[2].size = strlen(mb[2].ptr);
+		i++;
+	}
+	if (ecb->outf(ecb->priv, mb, i) < 0) {
+
+		return -1;
+	}
+
+	return 0;
+}
+
+void *xdl_mmfile_first(mmfile_t *mmf, long *size)
+{
+	*size = mmf->size;
+	return mmf->ptr;
+}
+
+
+long xdl_mmfile_size(mmfile_t *mmf)
+{
+	return mmf->size;
+}
+
+
+int xdl_cha_init(chastore_t *cha, long isize, long icount) {
+
+	cha->head = cha->tail = NULL;
+	cha->isize = isize;
+	cha->nsize = icount * isize;
+	cha->ancur = cha->sncur = NULL;
+	cha->scurr = 0;
+
+	return 0;
+}
+
+
+void xdl_cha_free(chastore_t *cha) {
+	chanode_t *cur, *tmp;
+
+	for (cur = cha->head; (tmp = cur) != NULL;) {
+		cur = cur->next;
+		xdl_free(tmp);
+	}
+}
+
+
+void *xdl_cha_alloc(chastore_t *cha) {
+	chanode_t *ancur;
+	void *data;
+
+	if (!(ancur = cha->ancur) || ancur->icurr == cha->nsize) {
+		if (!(ancur = (chanode_t *) xdl_malloc(sizeof(chanode_t) + cha->nsize))) {
+
+			return NULL;
+		}
+		ancur->icurr = 0;
+		ancur->next = NULL;
+		if (cha->tail)
+			cha->tail->next = ancur;
+		if (!cha->head)
+			cha->head = ancur;
+		cha->tail = ancur;
+		cha->ancur = ancur;
+	}
+
+	data = (char *) ancur + sizeof(chanode_t) + ancur->icurr;
+	ancur->icurr += cha->isize;
+
+	return data;
+}
+
+long xdl_guess_lines(mmfile_t *mf, long sample) {
+	long nl = 0, size, tsize = 0;
+	char const *data, *cur, *top;
+
+	if ((cur = data = xdl_mmfile_first(mf, &size)) != NULL) {
+		for (top = data + size; nl < sample && cur < top; ) {
+			nl++;
+			if (!(cur = memchr(cur, '\n', top - cur)))
+				cur = top;
+			else
+				cur++;
+		}
+		tsize += (long) (cur - data);
+	}
+
+	if (nl && tsize)
+		nl = xdl_mmfile_size(mf) / (tsize / nl);
+
+	return nl + 1;
+}
+
+int xdl_blankline(const char *line, long size, long flags)
+{
+	long i;
+
+	if (!(flags & XDF_WHITESPACE_FLAGS))
+		return (size <= 1);
+
+	for (i = 0; i < size && XDL_ISSPACE(line[i]); i++)
+		;
+
+	return (i == size);
+}
+
+/*
+ * Have we eaten everything on the line, except for an optional
+ * CR at the very end?
+ */
+static int ends_with_optional_cr(const char *l, long s, long i)
+{
+	int complete = s && l[s-1] == '\n';
+
+	if (complete)
+		s--;
+	if (s == i)
+		return 1;
+	/* do not ignore CR at the end of an incomplete line */
+	if (complete && s == i + 1 && l[i] == '\r')
+		return 1;
+	return 0;
+}
+
+int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags)
+{
+	int i1, i2;
+
+	if (s1 == s2 && !memcmp(l1, l2, s1))
+		return 1;
+	if (!(flags & XDF_WHITESPACE_FLAGS))
+		return 0;
+
+	i1 = 0;
+	i2 = 0;
+
+	/*
+	 * -w matches everything that matches with -b, and -b in turn
+	 * matches everything that matches with --ignore-space-at-eol,
+	 * which in turn matches everything that matches with --ignore-cr-at-eol.
+	 *
+	 * Each flavor of ignoring needs different logic to skip whitespaces
+	 * while we have both sides to compare.
+	 */
+	if (flags & XDF_IGNORE_WHITESPACE) {
+		goto skip_ws;
+		while (i1 < s1 && i2 < s2) {
+			if (l1[i1++] != l2[i2++])
+				return 0;
+		skip_ws:
+			while (i1 < s1 && XDL_ISSPACE(l1[i1]))
+				i1++;
+			while (i2 < s2 && XDL_ISSPACE(l2[i2]))
+				i2++;
+		}
+	} else if (flags & XDF_IGNORE_WHITESPACE_CHANGE) {
+		while (i1 < s1 && i2 < s2) {
+			if (XDL_ISSPACE(l1[i1]) && XDL_ISSPACE(l2[i2])) {
+				/* Skip matching spaces and try again */
+				while (i1 < s1 && XDL_ISSPACE(l1[i1]))
+					i1++;
+				while (i2 < s2 && XDL_ISSPACE(l2[i2]))
+					i2++;
+				continue;
+			}
+			if (l1[i1++] != l2[i2++])
+				return 0;
+		}
+	} else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL) {
+		while (i1 < s1 && i2 < s2 && l1[i1] == l2[i2]) {
+			i1++;
+			i2++;
+		}
+	} else if (flags & XDF_IGNORE_CR_AT_EOL) {
+		/* Find the first difference and see how the line ends */
+		while (i1 < s1 && i2 < s2 && l1[i1] == l2[i2]) {
+			i1++;
+			i2++;
+		}
+		return (ends_with_optional_cr(l1, s1, i1) &&
+			ends_with_optional_cr(l2, s2, i2));
+	}
+
+	/*
+	 * After running out of one side, the remaining side must have
+	 * nothing but whitespace for the lines to match.  Note that
+	 * ignore-whitespace-at-eol case may break out of the loop
+	 * while there still are characters remaining on both lines.
+	 */
+	if (i1 < s1) {
+		while (i1 < s1 && XDL_ISSPACE(l1[i1]))
+			i1++;
+		if (s1 != i1)
+			return 0;
+	}
+	if (i2 < s2) {
+		while (i2 < s2 && XDL_ISSPACE(l2[i2]))
+			i2++;
+		return (s2 == i2);
+	}
+	return 1;
+}
+
+static unsigned long xdl_hash_record_with_whitespace(char const **data,
+		char const *top, long flags) {
+	unsigned long ha = 5381;
+	char const *ptr = *data;
+	int cr_at_eol_only = (flags & XDF_WHITESPACE_FLAGS) == XDF_IGNORE_CR_AT_EOL;
+
+	for (; ptr < top && *ptr != '\n'; ptr++) {
+		if (cr_at_eol_only) {
+			/* do not ignore CR at the end of an incomplete line */
+			if (*ptr == '\r' &&
+			    (ptr + 1 < top && ptr[1] == '\n'))
+				continue;
+		}
+		else if (XDL_ISSPACE(*ptr)) {
+			const char *ptr2 = ptr;
+			int at_eol;
+			while (ptr + 1 < top && XDL_ISSPACE(ptr[1])
+					&& ptr[1] != '\n')
+				ptr++;
+			at_eol = (top <= ptr + 1 || ptr[1] == '\n');
+			if (flags & XDF_IGNORE_WHITESPACE)
+				; /* already handled */
+			else if (flags & XDF_IGNORE_WHITESPACE_CHANGE
+				 && !at_eol) {
+				ha += (ha << 5);
+				ha ^= (unsigned long) ' ';
+			}
+			else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL
+				 && !at_eol) {
+				while (ptr2 != ptr + 1) {
+					ha += (ha << 5);
+					ha ^= (unsigned long) *ptr2;
+					ptr2++;
+				}
+			}
+			continue;
+		}
+		ha += (ha << 5);
+		ha ^= (unsigned long) *ptr;
+	}
+	*data = ptr < top ? ptr + 1: ptr;
+
+	return ha;
+}
+
+unsigned long xdl_hash_record(char const **data, char const *top, long flags) {
+	unsigned long ha = 5381;
+	char const *ptr = *data;
+
+	if (flags & XDF_WHITESPACE_FLAGS)
+		return xdl_hash_record_with_whitespace(data, top, flags);
+
+	for (; ptr < top && *ptr != '\n'; ptr++) {
+		ha += (ha << 5);
+		ha ^= (unsigned long) *ptr;
+	}
+	*data = ptr < top ? ptr + 1: ptr;
+
+	return ha;
+}
+
+unsigned int xdl_hashbits(unsigned int size) {
+	unsigned int val = 1, bits = 0;
+
+	for (; val < size && bits < CHAR_BIT * sizeof(unsigned int); val <<= 1, bits++);
+	return bits ? bits: 1;
+}
+
+
+int xdl_num_out(char *out, long val) {
+	char *ptr, *str = out;
+	char buf[32];
+
+	ptr = buf + sizeof(buf) - 1;
+	*ptr = '\0';
+	if (val < 0) {
+		*--ptr = '-';
+		val = -val;
+	}
+	for (; val && ptr > buf; val /= 10)
+		*--ptr = "0123456789"[val % 10];
+	if (*ptr)
+		for (; *ptr; ptr++, str++)
+			*str = *ptr;
+	else
+		*str++ = '0';
+	*str = '\0';
+
+	return str - out;
+}
+
+int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2,
+		      const char *func, long funclen, xdemitcb_t *ecb) {
+	int nb = 0;
+	mmbuffer_t mb;
+	char buf[128];
+
+	memcpy(buf, "@@ -", 4);
+	nb += 4;
+
+	nb += xdl_num_out(buf + nb, c1 ? s1: s1 - 1);
+
+	if (c1 != 1) {
+		memcpy(buf + nb, ",", 1);
+		nb += 1;
+
+		nb += xdl_num_out(buf + nb, c1);
+	}
+
+	memcpy(buf + nb, " +", 2);
+	nb += 2;
+
+	nb += xdl_num_out(buf + nb, c2 ? s2: s2 - 1);
+
+	if (c2 != 1) {
+		memcpy(buf + nb, ",", 1);
+		nb += 1;
+
+		nb += xdl_num_out(buf + nb, c2);
+	}
+
+	memcpy(buf + nb, " @@", 3);
+	nb += 3;
+	if (func && funclen) {
+		buf[nb++] = ' ';
+		if (funclen > (long)(sizeof(buf) - nb - 1))
+			funclen = sizeof(buf) - nb - 1;
+		memcpy(buf + nb, func, funclen);
+		nb += funclen;
+	}
+	buf[nb++] = '\n';
+
+	mb.ptr = buf;
+	mb.size = nb;
+	if (ecb->outf(ecb->priv, &mb, 1) < 0)
+		return -1;
+
+	return 0;
+}
+
+int xdl_fall_back_diff(xdfenv_t *diff_env, xpparam_t const *xpp,
+		int line1, int count1, int line2, int count2)
+{
+	/*
+	 * This probably does not work outside Git, since
+	 * we have a very simple mmfile structure.
+	 *
+	 * Note: ideally, we would reuse the prepared environment, but
+	 * the libxdiff interface does not (yet) allow for diffing only
+	 * ranges of lines instead of the whole files.
+	 */
+	mmfile_t subfile1, subfile2;
+	xdfenv_t env;
+
+	subfile1.ptr = (char *)diff_env->xdf1.recs[line1 - 1]->ptr;
+	subfile1.size = diff_env->xdf1.recs[line1 + count1 - 2]->ptr +
+		diff_env->xdf1.recs[line1 + count1 - 2]->size - subfile1.ptr;
+	subfile2.ptr = (char *)diff_env->xdf2.recs[line2 - 1]->ptr;
+	subfile2.size = diff_env->xdf2.recs[line2 + count2 - 2]->ptr +
+		diff_env->xdf2.recs[line2 + count2 - 2]->size - subfile2.ptr;
+	if (xdl_do_diff(&subfile1, &subfile2, xpp, &env) < 0)
+		return -1;
+
+	memcpy(diff_env->xdf1.rchg + line1 - 1, env.xdf1.rchg, count1);
+	memcpy(diff_env->xdf2.rchg + line2 - 1, env.xdf2.rchg, count2);
+
+	xdl_free_env(&env);
+
+	return 0;
+}

vendor/libgit2-sys/libgit2/src/xdiff/xutils.h

diff --git a/vendor/libgit2-sys/libgit2/src/xdiff/xutils.h b/vendor/libgit2-sys/libgit2/src/xdiff/xutils.h
new file mode 100644
index 0000000..fba7bae
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/xdiff/xutils.h
@@ -0,0 +1,47 @@
+/*
+ *  LibXDiff by Davide Libenzi ( File Differential Library )
+ *  Copyright (C) 2003  Davide Libenzi
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, see
+ *  <http://www.gnu.org/licenses/>.
+ *
+ *  Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#if !defined(XUTILS_H)
+#define XUTILS_H
+
+
+
+long xdl_bogosqrt(long n);
+int xdl_emit_diffrec(char const *rec, long size, char const *pre, long psize,
+		     xdemitcb_t *ecb);
+int xdl_cha_init(chastore_t *cha, long isize, long icount);
+void xdl_cha_free(chastore_t *cha);
+void *xdl_cha_alloc(chastore_t *cha);
+long xdl_guess_lines(mmfile_t *mf, long sample);
+int xdl_blankline(const char *line, long size, long flags);
+int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags);
+unsigned long xdl_hash_record(char const **data, char const *top, long flags);
+unsigned int xdl_hashbits(unsigned int size);
+int xdl_num_out(char *out, long val);
+int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2,
+		      const char *func, long funclen, xdemitcb_t *ecb);
+int xdl_fall_back_diff(xdfenv_t *diff_env, xpparam_t const *xpp,
+		       int line1, int count1, int line2, int count2);
+
+
+
+#endif /* #if !defined(XUTILS_H) */

vendor/libgit2-sys/libgit2/src/zstream.c

diff --git a/vendor/libgit2-sys/libgit2/src/zstream.c b/vendor/libgit2-sys/libgit2/src/zstream.c
new file mode 100644
index 0000000..affa556
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/zstream.c
@@ -0,0 +1,205 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "zstream.h"
+
+#include <zlib.h>
+
+#include "buffer.h"
+
+#define ZSTREAM_BUFFER_SIZE (1024 * 1024)
+#define ZSTREAM_BUFFER_MIN_EXTRA 8
+
+GIT_INLINE(int) zstream_seterr(git_zstream *zs)
+{
+	switch (zs->zerr) {
+	case Z_OK:
+	case Z_STREAM_END:
+	case Z_BUF_ERROR: /* not fatal; we retry with a larger buffer */
+		return 0;
+	case Z_MEM_ERROR:
+		giterr_set_oom();
+		break;
+	default:
+		if (zs->z.msg)
+			giterr_set_str(GITERR_ZLIB, zs->z.msg);
+		else
+			giterr_set(GITERR_ZLIB, "unknown compression error");
+	}
+
+	return -1;
+}
+
+int git_zstream_init(git_zstream *zstream, git_zstream_t type)
+{
+	zstream->type = type;
+
+	if (zstream->type == GIT_ZSTREAM_INFLATE)
+		zstream->zerr = inflateInit(&zstream->z);
+	else
+		zstream->zerr = deflateInit(&zstream->z, Z_DEFAULT_COMPRESSION);
+	return zstream_seterr(zstream);
+}
+
+void git_zstream_free(git_zstream *zstream)
+{
+	if (zstream->type == GIT_ZSTREAM_INFLATE)
+		inflateEnd(&zstream->z);
+	else
+		deflateEnd(&zstream->z);
+}
+
+void git_zstream_reset(git_zstream *zstream)
+{
+	if (zstream->type == GIT_ZSTREAM_INFLATE)
+		inflateReset(&zstream->z);
+	else
+		deflateReset(&zstream->z);
+	zstream->in = NULL;
+	zstream->in_len = 0;
+	zstream->zerr = Z_STREAM_END;
+}
+
+int git_zstream_set_input(git_zstream *zstream, const void *in, size_t in_len)
+{
+	zstream->in = in;
+	zstream->in_len = in_len;
+	zstream->zerr = Z_OK;
+	return 0;
+}
+
+bool git_zstream_done(git_zstream *zstream)
+{
+	return (!zstream->in_len && zstream->zerr == Z_STREAM_END);
+}
+
+size_t git_zstream_suggest_output_len(git_zstream *zstream)
+{
+	if (zstream->in_len > ZSTREAM_BUFFER_SIZE)
+		return ZSTREAM_BUFFER_SIZE;
+	else if (zstream->in_len > ZSTREAM_BUFFER_MIN_EXTRA)
+		return zstream->in_len;
+	else
+		return ZSTREAM_BUFFER_MIN_EXTRA;
+}
+
+int git_zstream_get_output_chunk(
+	void *out, size_t *out_len, git_zstream *zstream)
+{
+	size_t in_queued, in_used, out_queued;
+
+	/* set up input data */
+	zstream->z.next_in = (Bytef *)zstream->in;
+
+	/* feed as much data to zlib as it can consume, at most UINT_MAX */
+	if (zstream->in_len > UINT_MAX) {
+		zstream->z.avail_in = UINT_MAX;
+		zstream->flush = Z_NO_FLUSH;
+	} else {
+		zstream->z.avail_in = (uInt)zstream->in_len;
+		zstream->flush = Z_FINISH;
+	}
+	in_queued = (size_t)zstream->z.avail_in;
+
+	/* set up output data */
+	zstream->z.next_out = out;
+	zstream->z.avail_out = (uInt)*out_len;
+
+	if ((size_t)zstream->z.avail_out != *out_len)
+		zstream->z.avail_out = UINT_MAX;
+	out_queued = (size_t)zstream->z.avail_out;
+
+	/* compress next chunk */
+	if (zstream->type == GIT_ZSTREAM_INFLATE)
+		zstream->zerr = inflate(&zstream->z, zstream->flush);
+	else
+		zstream->zerr = deflate(&zstream->z, zstream->flush);
+
+	if (zstream_seterr(zstream))
+		return -1;
+
+	in_used = (in_queued - zstream->z.avail_in);
+	zstream->in_len -= in_used;
+	zstream->in += in_used;
+
+	*out_len = (out_queued - zstream->z.avail_out);
+
+	return 0;
+}
+
+int git_zstream_get_output(void *out, size_t *out_len, git_zstream *zstream)
+{
+	size_t out_remain = *out_len;
+
+	if (zstream->in_len && zstream->zerr == Z_STREAM_END) {
+		giterr_set(GITERR_ZLIB, "zlib input had trailing garbage");
+		return -1;
+	}
+
+	while (out_remain > 0 && zstream->zerr != Z_STREAM_END) {
+		size_t out_written = out_remain;
+
+		if (git_zstream_get_output_chunk(out, &out_written, zstream) < 0)
+			return -1;
+
+		out_remain -= out_written;
+		out = ((char *)out) + out_written;
+	}
+
+	/* either we finished the input or we did not flush the data */
+	assert(zstream->in_len > 0 || zstream->flush == Z_FINISH);
+
+	/* set out_size to number of bytes actually written to output */
+	*out_len = *out_len - out_remain;
+
+	return 0;
+}
+
+static int zstream_buf(git_buf *out, const void *in, size_t in_len, git_zstream_t type)
+{
+	git_zstream zs = GIT_ZSTREAM_INIT;
+	int error = 0;
+
+	if ((error = git_zstream_init(&zs, type)) < 0)
+		return error;
+
+	if ((error = git_zstream_set_input(&zs, in, in_len)) < 0)
+		goto done;
+
+	while (!git_zstream_done(&zs)) {
+		size_t step = git_zstream_suggest_output_len(&zs), written;
+
+		if ((error = git_buf_grow_by(out, step)) < 0)
+			goto done;
+
+		written = out->asize - out->size;
+
+		if ((error = git_zstream_get_output(
+				out->ptr + out->size, &written, &zs)) < 0)
+			goto done;
+
+		out->size += written;
+	}
+
+	/* NULL terminate for consistency if possible */
+	if (out->size < out->asize)
+		out->ptr[out->size] = '\0';
+
+done:
+	git_zstream_free(&zs);
+	return error;
+}
+
+int git_zstream_deflatebuf(git_buf *out, const void *in, size_t in_len)
+{
+	return zstream_buf(out, in, in_len, GIT_ZSTREAM_DEFLATE);
+}
+
+int git_zstream_inflatebuf(git_buf *out, const void *in, size_t in_len)
+{
+	return zstream_buf(out, in, in_len, GIT_ZSTREAM_INFLATE);
+}

vendor/libgit2-sys/libgit2/src/zstream.h

diff --git a/vendor/libgit2-sys/libgit2/src/zstream.h b/vendor/libgit2-sys/libgit2/src/zstream.h
new file mode 100644
index 0000000..47ecc13
--- /dev/null
+++ b/vendor/libgit2-sys/libgit2/src/zstream.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_zstream_h__
+#define INCLUDE_zstream_h__
+
+#include "common.h"
+
+#include <zlib.h>
+
+#include "buffer.h"
+
+typedef enum {
+	GIT_ZSTREAM_INFLATE,
+	GIT_ZSTREAM_DEFLATE,
+} git_zstream_t;
+
+typedef struct {
+	z_stream z;
+	git_zstream_t type;
+	const char *in;
+	size_t in_len;
+	int flush;
+	int zerr;
+} git_zstream;
+
+#define GIT_ZSTREAM_INIT {{0}}
+
+int git_zstream_init(git_zstream *zstream, git_zstream_t type);
+void git_zstream_free(git_zstream *zstream);
+
+int git_zstream_set_input(git_zstream *zstream, const void *in, size_t in_len);
+
+size_t git_zstream_suggest_output_len(git_zstream *zstream);
+
+/* get as much output as is available in the input buffer */
+int git_zstream_get_output_chunk(
+	void *out, size_t *out_len, git_zstream *zstream);
+
+/* get all the output from the entire input buffer */
+int git_zstream_get_output(void *out, size_t *out_len, git_zstream *zstream);
+
+bool git_zstream_done(git_zstream *zstream);
+
+void git_zstream_reset(git_zstream *zstream);
+
+int git_zstream_deflatebuf(git_buf *out, const void *in, size_t in_len);
+int git_zstream_inflatebuf(git_buf *out, const void *in, size_t in_len);
+
+#endif