commit a08900b721fc8c5e26215dabe62c4124985d434d
author Garret Rieger <grieger@google.com> Tue May 04 16:48:41 2021 -0700
committer Behdad Esfahbod <behdad@behdad.org> Mon May 10 15:33:54 2021 -0600
tree 90babb33b188048e77fe5349322270d914db2265
parent b54d9b695a17afb86f022084e12d72bb4a199673

[subset] fix failing colrv0 subsetting when font has composite glyphs.

Composite glyph collection was happening along side colrv0 glyph collection which meant it was possible to miss grabbing the component glyphs for a glyph added by colrv0.

src/hb-subset-plan.cc

diff --git a/src/hb-subset-plan.cc b/src/hb-subset-plan.cc
index dfb0d42..90161c5 100644
--- a/src/hb-subset-plan.cc
+++ b/src/hb-subset-plan.cc
@@ -254,18 +254,26 @@
 #endif
   _remove_invalid_gids (plan->_glyphset_gsub, plan->source->get_num_glyphs ());
 
+  // Collect all glyphs referenced by COLRv0
+  hb_set_t* cur_glyphset = plan->_glyphset_gsub;
+  hb_set_t glyphset_colrv0;
+  if (colr.is_valid ())
+  {
+    glyphset_colrv0.union_ (cur_glyphset);
+    for (hb_codepoint_t gid : cur_glyphset->iter ())
+      colr.closure_glyphs (gid, &glyphset_colrv0);
+    cur_glyphset = &glyphset_colrv0;
+  }
+
   // Populate a full set of glyphs to retain by adding all referenced
   // composite glyphs.
-  hb_codepoint_t gid = HB_SET_VALUE_INVALID;
-  while (plan->_glyphset_gsub->next (&gid))
+  for (hb_codepoint_t gid : cur_glyphset->iter ())
   {
     glyf.add_gid_and_children (gid, plan->_glyphset);
 #ifndef HB_NO_SUBSET_CFF
     if (cff.is_valid ())
       _add_cff_seac_components (cff, gid, plan->_glyphset);
 #endif
-    if (colr.is_valid ())
-      colr.closure_glyphs (gid, plan->_glyphset);
   }
 
   _remove_invalid_gids (plan->_glyphset, plan->source->get_num_glyphs ());