[sfnt] Improve handling for buggy variation fonts.

Reported as

  https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=738

* src/sfnt/sfobjs.c (sfnt_init_face): While setting number of
instances to zero for `CFF' fonts table, ensure that there is no `glyf'
present also (which gets priority).
This commit is contained in:
Werner Lemberg 2017-03-07 17:27:58 +01:00
parent 27fee7f8c6
commit 7793097442
2 changed files with 17 additions and 4 deletions

View File

@ -1,3 +1,15 @@
2017-03-07 Werner Lemberg <wl@gnu.org>
[sfnt] Improve handling for buggy variation fonts.
Reported as
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=738
* src/sfnt/sfobjs.c (sfnt_init_face): While setting number of
instances to zero for `CFF' fonts table, ensure that there is no `glyf'
present also (which gets priority).
2017-03-06 Werner Lemberg <wl@gnu.org>
[sfnt, truetype] Always provide default instance.

View File

@ -999,10 +999,6 @@
else
face->variation_support |= TT_FACE_FLAG_VAR_FVAR;
/* we don't support Multiple Master CFFs yet */
if ( !face->goto_table( face, TTAG_CFF, stream, 0 ) )
num_instances = 0;
/*
* As documented in the OpenType specification, an entry for the
* default instance may be omitted in the named instance table. In
@ -1062,6 +1058,11 @@
FT_FREE( default_values );
FT_FREE( instance_values );
/* we don't support Multiple Master CFFs yet */
if ( face->goto_table( face, TTAG_glyf, stream, 0 ) &&
!face->goto_table( face, TTAG_CFF, stream, 0 ) )
num_instances = 0;
/* instance indices in `face_instance_index' start with index 1, */
/* thus `>' and not `>=' */
if ( instance_index > num_instances )