Fix T99872: Crash Loading Embedded Fonts - 3.3blender-v3.3-release

Ensure kerning cache exists when loading embedded fonts

---

When loading embedded fonts from memory the font->kerning_cache is not
created and so we get a crash if the font does support kerning.
This was not caught because the loading of packed fonts was not
actually doing anything in VSE until {523bc981cfee}.

We have since consolidated `blf_font_new` and `blf_font_new_from_mem`
into a single function so that they cannot get out of sync like this
any more.  So this fix is specific to Blender 3.3.  But we can add this
as a candidate for corrective release 3.2.3

Reviewed By: brecht

Maniphest Tasks: T99872

Differential Revision: https://developer.blender.org/D15704

1 files changed, 14 insertions, 3 deletions

diff --git a/source/blender/blenfont/intern/blf_font.c b/source/blender/blenfont/intern/blf_font.c
index 038e73cc928..07d19f307a2 100644
--- a/source/blender/blenfont/intern/blf_font.c
+++ b/source/blender/blenfont/intern/blf_font.c
@@ -1356,13 +1356,24 @@ FontBLF *blf_font_new_from_mem(const char *name, const unsigned char *mem, int m
     return NULL;
   }
 
+  font->name = BLI_strdup(name);
+  font->filepath = NULL;
+  blf_font_fill(font);
+
   if (FT_HAS_MULTIPLE_MASTERS(font->face)) {
     FT_Get_MM_Var(font->face, &(font->variations));
   }
 
-  font->name = BLI_strdup(name);
-  font->filepath = NULL;
-  blf_font_fill(font);
+  if (FT_HAS_KERNING(font->face)) {
+    /* Create kerning cache table and fill with value indicating "unset". */
+    font->kerning_cache = MEM_mallocN(sizeof(KerningCacheBLF), __func__);
+    for (uint i = 0; i < KERNING_CACHE_TABLE_SIZE; i++) {
+      for (uint j = 0; j < KERNING_CACHE_TABLE_SIZE; j++) {
+        font->kerning_cache->ascii_table[i][j] = KERNING_ENTRY_UNSET;
+      }
+    }
+  }
+
   return font;
 }