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Fix compatibility problems with several fonts

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* src/sfnt.c (sfnt_lookup_glyph_8): Perform binary search
instead of combing through each group if the table is large.
(sfnt_read_simple_glyph): Avoid losing if the last byte of a
vector is identical to the last byte of the glyph data.
(sfnt_read_gvar_table): Don't overwrite gvar table data while
reading shared coordinates.
This commit is contained in:
Po Lu 2023-08-23 09:08:03 +08:00
parent 255b7e1a04
commit d2e8985b80
1 changed files with 45 additions and 19 deletions
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64
src/sfnt.c
View file

@ -1262,6 +1262,19 @@ sfnt_lookup_glyph_6 (sfnt_char character,
return format6->glyph_index_array[character - format6->first_code];
}
/* Compare the sfnt_char A with B's end code. Employed to bisect
through a format 8 or 12 table. */
static int
sfnt_compare_char (const void *a, const void *b)
{
struct sfnt_cmap_format_8_or_12_group *group;
group = (struct sfnt_cmap_format_8_or_12_group *) b;
return ((int) *((sfnt_char *) a)) - group->end_char_code;
}
/* Look up the glyph corresponding to CHARACTER in the format 8 cmap
FORMAT8. Return 0 if no glyph was found. */
@ -1270,10 +1283,35 @@ sfnt_lookup_glyph_8 (sfnt_char character,
struct sfnt_cmap_format_8 *format8)
{
uint32_t i;
struct sfnt_cmap_format_8_or_12_group *group;
if (character > 0xffffffff)
return 0;
if (format8->num_groups > 64)
{
/* This table is large, likely supplied by a CJK or similar
font. Perform a binary search. */
/* Find the group whose END_CHAR_CODE is greater than or equal
to CHARACTER. */
group = sfnt_bsearch_above (&character, format8->groups,
format8->num_groups,
sizeof format8->groups[0],
sfnt_compare_char);
if (group->start_char_code > character)
/* No glyph matches this group. */
return 0;
/* Otherwise, use this group to map the character to a
glyph. */
return (group->start_glyph_code
+ character
- group->start_char_code);
}
for (i = 0; i < format8->num_groups; ++i)
{
if (format8->groups[i].start_char_code <= character
@ -1286,19 +1324,6 @@ sfnt_lookup_glyph_8 (sfnt_char character,
return 0;
}
/* Compare the sfnt_char A with B's end code. Employed to bisect
through a format 12 table. */
static int
sfnt_compare_char (const void *a, const void *b)
{
struct sfnt_cmap_format_8_or_12_group *group;
group = (struct sfnt_cmap_format_8_or_12_group *) b;
return ((int) *((sfnt_char *) a)) - group->end_char_code;
}
/* Look up the glyph corresponding to CHARACTER in the format 12 cmap
FORMAT12. Return 0 if no glyph was found. */
@ -2009,7 +2034,7 @@ sfnt_read_simple_glyph (struct sfnt_glyph *glyph,
/* The next byte is a delta to apply to the previous
value. Make sure it is in bounds. */
if (vec_start + 1 >= glyf->glyphs + glyf->size)
if (vec_start + 1 > glyf->glyphs + glyf->size)
{
glyph->simple = NULL;
xfree (simple);
@ -2026,7 +2051,7 @@ sfnt_read_simple_glyph (struct sfnt_glyph *glyph,
/* The next word is a delta to apply to the previous value.
Make sure it is in bounds. */
if (vec_start + 2 >= glyf->glyphs + glyf->size)
if (vec_start + 2 > glyf->glyphs + glyf->size)
{
glyph->simple = NULL;
xfree (simple);
@ -2061,7 +2086,7 @@ sfnt_read_simple_glyph (struct sfnt_glyph *glyph,
/* The next byte is a delta to apply to the previous
value. Make sure it is in bounds. */
if (vec_start + 1 >= glyf->glyphs + glyf->size)
if (vec_start + 1 > glyf->glyphs + glyf->size)
{
glyph->simple = NULL;
xfree (simple);
@ -2078,7 +2103,7 @@ sfnt_read_simple_glyph (struct sfnt_glyph *glyph,
/* The next word is a delta to apply to the previous value.
Make sure it is in bounds. */
if (vec_start + 2 >= glyf->glyphs + glyf->size)
if (vec_start + 2 > glyf->glyphs + glyf->size)
{
glyph->simple = NULL;
xfree (simple);
@ -13184,7 +13209,8 @@ sfnt_read_gvar_table (int fd, struct sfnt_offset_subtable *subtable)
/* Start reading shared coordinates. */
gvar->global_coords = ((sfnt_f2dot14 *) ((char *) gvar + off_size));
gvar->global_coords = ((sfnt_f2dot14 *) ((char *) (gvar + 1)
+ off_size));
if (gvar->shared_coord_count)
{
@ -13199,7 +13225,7 @@ sfnt_read_gvar_table (int fd, struct sfnt_offset_subtable *subtable)
!= coordinate_size)
goto bail;
for (i = 0; i <= coordinate_size / sizeof *gvar->global_coords; ++i)
for (i = 0; i < coordinate_size / sizeof *gvar->global_coords; ++i)
sfnt_swap16 (&gvar->global_coords[i]);
}