[freetype2] master 7e1b39f: [truetype] Fix UBSan warnings on adding offsets to nullptr.

[Werner LEMBERG]

branch: master
commit 7e1b39f6cd1f8e14d45592c9b192ade643d8d9de
Author: Werner Lemberg <address@hidden>
Commit: Werner Lemberg <address@hidden>

    [truetype] Fix UBSan warnings on adding offsets to nullptr.
    
    Reported as
    
      https://bugs.chromium.org/p/chromium/issues/detail?id=1032152
    
    * src/truetype/ttinterp.c (Ins_FDEF, Ins_IDEF): Use `FT_OFFSET'.
---
 ChangeLog               | 10 ++++++++++
 src/truetype/ttinterp.c |  4 ++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 720a38c..a93b43d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2019-12-16  Werner Lemberg  <address@hidden>
+
+       [truetype] Fix UBSan warnings on adding offsets to nullptr.
+
+       Reported as
+
+         https://bugs.chromium.org/p/chromium/issues/detail?id=1032152
+
+       * src/truetype/ttinterp.c (Ins_FDEF, Ins_IDEF): Use `FT_OFFSET'.
+
 2019-12-14  Werner Lemberg  <address@hidden>
 
        [truetype] Fix integer overflow.
diff --git a/src/truetype/ttinterp.c b/src/truetype/ttinterp.c
index 7d021eb..369c7b5 100644
--- a/src/truetype/ttinterp.c
+++ b/src/truetype/ttinterp.c
@@ -3718,7 +3718,7 @@
     /* We will then parse the current table.                       */
 
     rec   = exc->FDefs;
-    limit = rec + exc->numFDefs;
+    limit = FT_OFFSET( rec, exc->numFDefs );
     n     = (FT_ULong)args[0];
 
     for ( ; rec < limit; rec++ )
@@ -4150,7 +4150,7 @@
     /*  First of all, look for the same function in our table */
 
     def   = exc->IDefs;
-    limit = def + exc->numIDefs;
+    limit = FT_OFFSET( def, exc->numIDefs );
 
     for ( ; def < limit; def++ )
       if ( def->opc == (FT_ULong)args[0] )