[cmap] Make null accelerator safe

Fixes https://github.com/harfbuzz/harfbuzz/issues/1146
This commit is contained in:
Behdad Esfahbod 2018-11-05 13:45:12 -05:00
parent f6fc5574d3
commit bb380ec183
1 changed files with 25 additions and 25 deletions

View File

@ -1016,40 +1016,35 @@ struct cmap
{
this->blob = hb_sanitize_context_t().reference_table<cmap> (face);
const cmap *table = this->blob->as<cmap> ();
const CmapSubtableFormat14 *subtable_uvs = nullptr;
bool symbol;
subtable = table->find_best_subtable (&symbol);
subtableZ = table->find_best_subtable (&symbol);
/* UVS subtable. */
if (!subtable_uvs)
subtable_uvsZ = &Null(CmapSubtableFormat14);
{
const CmapSubtable *st = table->find_subtable (0, 5);
if (st && st->u.format == 14)
subtable_uvs = &st->u.format14;
subtable_uvsZ = &st->u.format14;
}
/* Meh. */
if (!subtable_uvs) subtable_uvs = &Null(CmapSubtableFormat14);
this->subtable_uvs = subtable_uvs;
this->get_glyph_data = subtable;
this->get_glyph_data = subtableZ;
if (unlikely (symbol))
{
this->get_glyph_func = get_glyph_from_symbol<CmapSubtable>;
this->get_glyph_funcZ = get_glyph_from_symbol<CmapSubtable>;
} else {
switch (subtable->u.format) {
switch (subtableZ->u.format) {
/* Accelerate format 4 and format 12. */
default:
this->get_glyph_func = get_glyph_from<CmapSubtable>;
this->get_glyph_funcZ = get_glyph_from<CmapSubtable>;
break;
case 12:
this->get_glyph_func = get_glyph_from<CmapSubtableFormat12>;
this->get_glyph_funcZ = get_glyph_from<CmapSubtableFormat12>;
break;
case 4:
{
this->format4_accel.init (&subtable->u.format4);
this->format4_accel.init (&subtableZ->u.format4);
this->get_glyph_data = &this->format4_accel;
this->get_glyph_func = this->format4_accel.get_glyph_func;
this->get_glyph_funcZ = this->format4_accel.get_glyph_func;
}
break;
}
@ -1064,16 +1059,18 @@ struct cmap
inline bool get_nominal_glyph (hb_codepoint_t unicode,
hb_codepoint_t *glyph) const
{
return this->get_glyph_func (this->get_glyph_data, unicode, glyph);
if (unlikely (!this->get_glyph_funcZ)) return false;
return this->get_glyph_funcZ (this->get_glyph_data, unicode, glyph);
}
inline bool get_variation_glyph (hb_codepoint_t unicode,
hb_codepoint_t variation_selector,
hb_codepoint_t *glyph) const
{
switch (this->subtable_uvs->get_glyph_variant (unicode,
variation_selector,
glyph))
if (unlikely (!this->subtable_uvsZ)) return false;
switch (this->subtable_uvsZ->get_glyph_variant (unicode,
variation_selector,
glyph))
{
case GLYPH_VARIANT_NOT_FOUND: return false;
case GLYPH_VARIANT_FOUND: return true;
@ -1085,16 +1082,19 @@ struct cmap
inline void collect_unicodes (hb_set_t *out) const
{
subtable->collect_unicodes (out);
if (unlikely (!this->subtableZ)) return;
subtableZ->collect_unicodes (out);
}
inline void collect_variation_selectors (hb_set_t *out) const
{
subtable_uvs->collect_variation_selectors (out);
if (unlikely (!this->subtable_uvsZ)) return;
subtable_uvsZ->collect_variation_selectors (out);
}
inline void collect_variation_unicodes (hb_codepoint_t variation_selector,
hb_set_t *out) const
{
subtable_uvs->collect_variation_unicodes (variation_selector, out);
if (unlikely (!this->subtable_uvsZ)) return;
subtable_uvsZ->collect_variation_unicodes (variation_selector, out);
}
protected:
@ -1134,10 +1134,10 @@ struct cmap
}
private:
const CmapSubtable *subtable;
const CmapSubtableFormat14 *subtable_uvs;
const CmapSubtable *subtableZ;
const CmapSubtableFormat14 *subtable_uvsZ;
hb_cmap_get_glyph_func_t get_glyph_func;
hb_cmap_get_glyph_func_t get_glyph_funcZ;
const void *get_glyph_data;
CmapSubtableFormat4::accelerator_t format4_accel;