Look for pylint comments disabling long lambda warnings

This allows long lambdas on a case-by-case basis.

CHANGELOG

diff --git a/CHANGELOG b/CHANGELOG
index 8e461a9..0a00c8c 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -12,6 +12,9 @@
   without wrapping. If not, then we split.
 - Check all of the elements of a tuple. Similarly to how arguments are
   analyzed. This allows tuples to be split more rationally.
+### Fixed
+- Attempt to determine if long lambdas are allowed. This can be done on a
+  case-by-case basis with a "pylint" disable comment.
 
 ## [0.21.0] 2018-03-18
 ### Added

yapf/yapflib/split_penalty.py

diff --git a/yapf/yapflib/split_penalty.py b/yapf/yapflib/split_penalty.py
index 9fae327..66f733f 100644
--- a/yapf/yapflib/split_penalty.py
+++ b/yapf/yapflib/split_penalty.py
@@ -13,6 +13,8 @@
 # limitations under the License.
 """Computation of split penalties before/between tokens."""
 
+import re
+
 from lib2to3 import pytree
 
 from yapf.yapflib import format_token
@@ -111,7 +113,15 @@
   def Visit_lambdef(self, node):  # pylint: disable=invalid-name
     # lambdef ::= 'lambda' [varargslist] ':' test
     # Loop over the lambda up to and including the colon.
-    if style.Get('ALLOW_MULTILINE_LAMBDAS'):
+    allow_multiline_lambdas = style.Get('ALLOW_MULTILINE_LAMBDAS')
+    if not allow_multiline_lambdas:
+      for child in node.children:
+        if pytree_utils.NodeName(child) == 'COMMENT':
+          if re.search(r'pylint:.*disable=.*\bg-long-lambda', child.value):
+            allow_multiline_lambdas = True
+            break
+
+    if allow_multiline_lambdas:
       _SetStronglyConnected(node)
     else:
       self._SetUnbreakableOnChildren(node)

yapftests/reformatter_buganizer_test.py

diff --git a/yapftests/reformatter_buganizer_test.py b/yapftests/reformatter_buganizer_test.py
index 0261798..5b50c28 100644
--- a/yapftests/reformatter_buganizer_test.py
+++ b/yapftests/reformatter_buganizer_test.py
@@ -28,6 +28,27 @@
   def setUpClass(cls):
     style.SetGlobalStyle(style.CreateChromiumStyle())
 
+  def testB37099651(self):
+    unformatted_code = """\
+_MEMCACHE = lazy.MakeLazy(
+    # pylint: disable=g-long-lambda
+    lambda: function.call.mem.clients(FLAGS.some_flag_thingy, default_namespace=_LAZY_MEM_NAMESPACE, allow_pickle=True)
+    # pylint: enable=g-long-lambda
+)
+"""
+    expected_formatted_code = """\
+_MEMCACHE = lazy.MakeLazy(
+    # pylint: disable=g-long-lambda
+    lambda: function.call.mem.clients(
+        FLAGS.some_flag_thingy,
+        default_namespace=_LAZY_MEM_NAMESPACE,
+        allow_pickle=True)
+    # pylint: enable=g-long-lambda
+)
+"""
+    uwlines = yapf_test_helper.ParseAndUnwrap(unformatted_code)
+    self.assertCodeEqual(expected_formatted_code, reformatter.Reformat(uwlines))
+
   def testB33228502(self):
     unformatted_code = """\
 def _():