[freetype2] master aae8808: [sfnt] Protect against zero-size bitmaps (#46345).

[Werner LEMBERG]

branch: master
commit aae8808780d4b73cf51f80ba40c4b7b854ca1487
Author: Werner Lemberg <address@hidden>
Commit: Werner Lemberg <address@hidden>

    [sfnt] Protect against zero-size bitmaps (#46345).
    
    * src/sfnt/ttsbit.c (tt_sbit_decoder_load_bitmap): Check
    `glyph_size'.
---
 ChangeLog         |    7 +++++++
 src/sfnt/ttsbit.c |    3 ++-
 2 files changed, 9 insertions(+), 1 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 80b0b2f..fb612da 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2015-11-03  Werner Lemberg  <address@hidden>
+
+       [sfnt] Protect against zero-size bitmaps (#46345).
+
+       * src/sfnt/ttsbit.c (tt_sbit_decoder_load_bitmap): Check
+       `glyph_size'.
+
 2015-11-02  Nikolaus Waxweiler  <address@hidden>
 
        * src/autofit/afloader.c (af_loader_load_g): Implement emboldening.
diff --git a/src/sfnt/ttsbit.c b/src/sfnt/ttsbit.c
index c0540f3..acc18f0 100644
--- a/src/sfnt/ttsbit.c
+++ b/src/sfnt/ttsbit.c
@@ -1025,7 +1025,8 @@
 
 
     /* seek into the EBDT table now */
-    if ( glyph_start + glyph_size > decoder->ebdt_size )
+    if ( !glyph_size                                   ||
+         glyph_start + glyph_size > decoder->ebdt_size )
     {
       error = FT_THROW( Invalid_Argument );
       goto Exit;