Tweak mark-base attachment
Apparently a base glyph can also become an attached component of a
ligature if the ligature-forming lookup used IgnoreBase. This was
being confused with a non-first component of a MultipleSubst and
hence not matched for mark-attachment. Tweak test to fix.
Fixes https://github.com/behdad/harfbuzz/issues/543
diff --git a/src/hb-ot-layout-gpos-table.hh b/src/hb-ot-layout-gpos-table.hh
index 738ca8c..e45ce27 100644
--- a/src/hb-ot-layout-gpos-table.hh
+++ b/src/hb-ot-layout-gpos-table.hh
@@ -1087,7 +1087,9 @@
do {
if (!skippy_iter.prev ()) return_trace (false);
/* We only want to attach to the first of a MultipleSubst sequence. Reject others. */
- if (0 == _hb_glyph_info_get_lig_comp (&buffer->info[skippy_iter.idx])) break;
+ if (!_hb_glyph_info_multiplied (&buffer->info[skippy_iter.idx]) ||
+ 0 == _hb_glyph_info_get_lig_comp (&buffer->info[skippy_iter.idx]))
+ break;
skippy_iter.reject ();
} while (1);
