Set charmap aggressively without all validations of `FT_Set_Charmap`
because we take it from the available array and only temporarily.
Even CMap Format 14 will gracefully return 0.
Add a check that the document content is actually contained within the
`SVG ` table. Without this check a malformed font may claim arbitrary
memory as its document content.
* src/sfnt/ttsvg.c (tt_face_load_svg): Take `numEntries` into account when
testing 'documentRecord' extents.
(find_doc): Rename `stream` to `document_records` for clarity.
(tt_face_load_svg_doc): Split `doc` from `doc_list` pointer for clarity.
Test that the document content is contained within the table.
Ensure minimum length of document before testing for gzip format.
Reported as
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=51812
* src/base/ftbitmap.c (FT_Bitmap_Copy): Flip the copy if its pitch
is trully opposite, zero is not a positive value.
(FT_Bitmap_Convert): Set negative pitch as needed, accept negative
alignment values.
Reusing target bitmaps for copying and converting is permitted. It is,
however, pointless to preserve their content before overwriting. Free-
malloc might be faster than realloc.
* src/base/ftbitmap.c (FT_Bitmap_Copy, FT_Bitmap_Convert): Free
an old buffer and create a new one.
* src/sfnt/ttcolr.c (tt_face_load_colr): If the version is determined to
be 1, then the table size has to be at least the size of the v1 header.
Also, for peeking the number of base glyphs and entries in the layer list,
ensure that the table is sufficiently long.
Fixes#1179. Original patch by Sergey Temnikov.
* src/truetype/ttgxvar.c (TT_Get_MM_Var): Reject retrieving master when
'fvar' values locally do not match with sanitized values from initialization
at `sfnt_init_face` time.
Reported as
https://bugs.chromium.org/p/chromium/issues/detail?id=1360295
Fixes#1178.
* src/sfnt/ttcolr.c (get_deltas_for_var_index_base): Set outer index to
0 and inner index to the delta index when retrieving deltas if the
`COLR` table has no delta set index map.
Fixes#1172.
* src/sfnt/sfobjs.c (sfnt_load_face): Tag font as Multiple Masters font if
`fvar` is present; do not require other tables to be present.
* src/truetype/ttgxvar.c (tt_set_mm_blend): Allow for a missing 'gvar' table
when setting variation coordinates. However, if a 'gvar' table is actually
present, do perform a sanity check and fail on malformedness.
(TT_Get_MM_Var): Don't assume 'fvar' needs 'gvar' or 'CFF2 tables in all
cases, which is an overly tight check.
This option uncomments FreeType configuration macro
`FT_CONFIG_OPTION_ERROR_STRINGS` to make function `FT_Error_String` return
meaningful error strings.
This option is off by default.
Anurag Thakur