From 98ac01d3b3deb7c7f5411f6f25c6e7588d84b5f9 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Mon, 1 Oct 2018 12:10:00 +0200
Subject: [PATCH] [morx] Break out if buffer gets into error

Was getting stuck not making progress somehow.
---
 src/hb-aat-layout-common.hh     | 2 ++
 src/hb-aat-layout-morx-table.hh | 4 ++++
 2 files changed, 6 insertions(+)

diff --git a/src/hb-aat-layout-common.hh b/src/hb-aat-layout-common.hh
index 052aad7fc..b0faa1db5 100644
--- a/src/hb-aat-layout-common.hh
+++ b/src/hb-aat-layout-common.hh
@@ -585,6 +585,8 @@ struct StateTableDriver
       if (unlikely (!c->transition (this, entry)))
         break;
 
+      if (unlikely (!buffer->successful)) return;
+
       last_was_dont_advance = (entry->flags & context_t::DontAdvance) && buffer->max_ops-- > 0;
 
       state = entry->newState;
diff --git a/src/hb-aat-layout-morx-table.hh b/src/hb-aat-layout-morx-table.hh
index 60d05e61a..c58e6744d 100644
--- a/src/hb-aat-layout-morx-table.hh
+++ b/src/hb-aat-layout-morx-table.hh
@@ -886,6 +886,8 @@ struct Chain
 
       (void) c->buffer->message (c->font, "end chain subtable %d", c->lookup_index);
 
+      if (unlikely (!c->buffer->successful)) return;
+
     skip:
       subtable = &StructAfter<ChainSubtable> (*subtable);
       c->set_lookup_index (c->lookup_index + 1);
@@ -942,12 +944,14 @@ struct morx
 
   inline void apply (hb_aat_apply_context_t *c) const
   {
+    if (unlikely (!c->buffer->successful)) return;
     c->set_lookup_index (0);
     const Chain *chain = &firstChain;
     unsigned int count = chainCount;
     for (unsigned int i = 0; i < count; i++)
     {
       chain->apply (c);
+      if (unlikely (!c->buffer->successful)) return;
       chain = &StructAfter<Chain> (*chain);
     }
   }