[subset] Fix memory leak caused by failure to cleanup glyf accelerator

src/hb-ot-glyf-table.hh

@@ -148,39 +148,49 @@ struct glyf
     glyf *glyf_prime = c->serializer->start_embed <glyf> ();
     if (unlikely (!glyf_prime)) return_trace (false);
 
-    OT::glyf::accelerator_t glyf;
-    glyf.init (c->plan->source);
-
     // Byte region(s) per glyph to output
     // unpadded, hints removed if so requested
     // If we fail to process a glyph we produce an empty (0-length) glyph
     hb_vector_t<SubsetGlyph> glyphs;
-    + hb_range (c->plan->num_output_glyphs ())
+    _populate_subset_glyphs (c->plan, &glyphs);
+
+    glyf_prime->serialize (c->serializer, hb_iter (glyphs), c->plan);
+
+    hb_vector_t<unsigned int> padded_offsets;
+    + hb_iter (glyphs)
+    | hb_map ([&] (const SubsetGlyph& _) { return _.padded_size(); })
+    | hb_sink (padded_offsets);
+
+    _add_loca_and_head (c->plan, hb_iter (padded_offsets));
+
+    return_trace (true);
+  }
+
+  template <typename SubsetGlyph>
+  void
+  _populate_subset_glyphs (const hb_subset_plan_t * plan,
+                           hb_vector_t<SubsetGlyph> * glyphs /* OUT */) const
+  {
+    OT::glyf::accelerator_t glyf;
+    glyf.init (plan->source);
+
+    + hb_range (plan->num_output_glyphs ())
     | hb_map ([&] (hb_codepoint_t new_gid) {
       SubsetGlyph subset_glyph;
       subset_glyph.new_gid = new_gid;
 
       // should never fail: all old gids should be mapped
-      if (!c->plan->old_gid_for_new_gid (new_gid, &subset_glyph.old_gid)) return subset_glyph;
+      if (!plan->old_gid_for_new_gid (new_gid, &subset_glyph.old_gid)) return subset_glyph;
 
       subset_glyph.source_glyph = glyf.bytes_for_glyph ((const char *) this, subset_glyph.old_gid);
-      if (c->plan->drop_hints) subset_glyph.drop_hints (glyf);
+      if (plan->drop_hints) subset_glyph.drop_hints (glyf);
       else subset_glyph.dest_start = subset_glyph.source_glyph;
 
       return subset_glyph;
     })
     | hb_sink (glyphs);
 
-    glyf_prime->serialize (c->serializer, hb_iter (glyphs), c->plan);
-
-    hb_vector_t<unsigned int> padded_offsets;
-    + hb_iter (glyphs)
-    | hb_map ([&] (const SubsetGlyph& _) { return _.padded_size(); })
-    | hb_sink (padded_offsets);
-
-    _add_loca_and_head (c->plan, hb_iter (padded_offsets));
-
-    return_trace (true);
+    glyf.fini();
   }
 
   static void