[pango/unsupported-formats] fc: Don't return fonts with unsupported formats

[Matthias Clasen <matthiasc src gnome org>]

commit 2ea2975bc18cab07482e960d60a1afeb33cb12a6
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Aug 3 17:48:50 2019 -0400

    fc: Don't return fonts with unsupported formats
    
    Make pango_fontset_foreach skip fonts that
    in formats that harfbuzz doesn't support.

 pango/pangofc-fontmap.c | 59 ++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 46 insertions(+), 13 deletions(-)
---
diff --git a/pango/pangofc-fontmap.c b/pango/pangofc-fontmap.c
index 43ab7dbc..d5f17740 100644
--- a/pango/pangofc-fontmap.c
+++ b/pango/pangofc-fontmap.c
@@ -896,11 +896,16 @@ pango_fc_fontset_get_key (PangoFcFontset *fontset)
 }
 
 static PangoFont *
-pango_fc_fontset_load_next_font (PangoFcFontset *fontset)
+pango_fc_fontset_load_next_font (PangoFcFontset *fontset,
+                                 gboolean       *skipped)
 {
   FcPattern *pattern, *font_pattern;
   PangoFont *font;
   gboolean prepare;
+  FcResult res;
+  const char *s;
+
+  *skipped = FALSE;
 
   pattern = pango_fc_patterns_get_pattern (fontset->patterns);
   font_pattern = pango_fc_patterns_get_font_pattern (fontset->patterns,
@@ -917,9 +922,18 @@ pango_fc_fontset_load_next_font (PangoFcFontset *fontset)
        return NULL;
     }
 
-  font = pango_fc_font_map_new_font (fontset->key->fontmap,
-                                    fontset->key,
-                                    font_pattern);
+  res = FcPatternGetString (font_pattern, FC_FONTFORMAT, 0, (FcChar8 **)(void*)&s);
+  g_assert (res == FcResultMatch);
+  /* harfbuzz does not support these */
+  if (strcmp (s, "Type 1") == 0 || strcmp (s, "PCF") == 0)
+    {
+      *skipped = TRUE;
+      font = NULL;
+    }
+  else
+    font = pango_fc_font_map_new_font (fontset->key->fontmap,
+                                       fontset->key,
+                                       font_pattern);
 
   if (prepare)
     FcPatternDestroy (font_pattern);
@@ -929,14 +943,15 @@ pango_fc_fontset_load_next_font (PangoFcFontset *fontset)
 
 static PangoFont *
 pango_fc_fontset_get_font_at (PangoFcFontset *fontset,
-                             unsigned int i)
+                             unsigned int    i,
+                              gboolean       *has_more)
 {
   while (i >= fontset->fonts->len)
     {
-      PangoFont *font = pango_fc_fontset_load_next_font (fontset);
+      PangoFont *font = pango_fc_fontset_load_next_font (fontset, has_more);
       g_ptr_array_add (fontset->fonts, font);
       g_ptr_array_add (fontset->coverages, NULL);
-      if (!font)
+      if (!*has_more)
         return NULL;
     }
 
@@ -1013,13 +1028,21 @@ pango_fc_fontset_get_font (PangoFontset  *fontset,
   PangoCoverage *coverage;
   int result = -1;
   unsigned int i;
+  gboolean has_more;
 
-  for (i = 0;
-       pango_fc_fontset_get_font_at (fcfontset, i);
-       i++)
+  for (i = 0; TRUE; i++)
     {
+      font = pango_fc_fontset_get_font_at (fcfontset, i, &has_more);
       coverage = g_ptr_array_index (fcfontset->coverages, i);
 
+      if (font == NULL)
+        {
+          if (has_more)
+            continue;
+          else
+            break;
+        }
+
       if (coverage == NULL)
        {
          font = g_ptr_array_index (fcfontset->fonts, i);
@@ -1053,12 +1076,21 @@ pango_fc_fontset_foreach (PangoFontset           *fontset,
 {
   PangoFcFontset *fcfontset = PANGO_FC_FONTSET (fontset);
   PangoFont *font;
+  gboolean has_more;
   unsigned int i;
 
-  for (i = 0;
-       (font = pango_fc_fontset_get_font_at (fcfontset, i));
-       i++)
+  for (i = 0; TRUE; i++)
     {
+      font = pango_fc_fontset_get_font_at (fcfontset, i, &has_more);
+
+      if (font == NULL)
+        {
+          if (has_more)
+            continue;
+          else
+            break;
+        }
+
       if ((*func) (fontset, font, data))
        return;
     }
@@ -1360,6 +1392,7 @@ pango_fc_font_map_list_families (PangoFontMap      *fontmap,
          PangoFcFamily *temp_family;
 
          res = FcPatternGetString (fontset->fonts[i], FC_FONTFORMAT, 0, (FcChar8 **)(void*)&s);
+         g_assert (res == FcResultMatch);
           if (strcmp (s, "Type 1") == 0 || strcmp (s, "PCF") == 0)
             continue; /* harfbuzz does not support these */