[HarfBuzz] harfbuzz: Branch 'master'

[Behdad Esfahbod]

 src/hb-aat-layout-morx-table.hh |    4 ++++
 1 file changed, 4 insertions(+)

New commits:
commit 0e5bcdef7fb592f986ad5b4e07b80d2efb5e3344
Author: Behdad Esfahbod <behdad at behdad.org>
Date:   Tue Oct 23 00:39:44 2018 -0700

    [morx] Clear stack upon underflow when acting ligatures

diff --git a/src/hb-aat-layout-morx-table.hh b/src/hb-aat-layout-morx-table.hh
index ddb444c2..3f5f29d1 100644
--- a/src/hb-aat-layout-morx-table.hh
+++ b/src/hb-aat-layout-morx-table.hh
@@ -402,7 +402,11 @@ struct LigatureSubtable
         do
 	{
 	  if (unlikely (!cursor))
+	  {
+	    /* Stack underflow.  Clear the stack. */
+	    match_length = 0;
 	    break;
+	  }
 
 	  buffer->move_to (match_positions[--cursor]);