[subset-plan] Simplify no_subset_tables allocation

src/hb-subset-plan.cc

@@ -848,7 +848,7 @@ hb_subset_plan_create_or_fail (hb_face_t	 *face,
   plan->layout_scripts = *input->sets.layout_scripts;
   plan->glyphs_requested = hb_set_copy (input->sets.glyphs);
   plan->drop_tables = *input->sets.drop_tables;
-  plan->no_subset_tables = hb_set_copy (input->sets.no_subset_tables);
+  plan->no_subset_tables = *input->sets.no_subset_tables;
   plan->source = hb_face_reference (face);
   plan->dest = hb_face_builder_create ();
 

src/hb-subset-plan.hh

@@ -50,7 +50,6 @@ struct hb_subset_plan_t
   {
     hb_set_destroy (unicodes);
     hb_set_destroy (glyphs_requested);
-    hb_set_destroy (no_subset_tables);
     hb_face_destroy (source);
     hb_face_destroy (dest);
     hb_map_destroy (codepoint_to_glyph);
@@ -110,7 +109,7 @@ struct hb_subset_plan_t
   hb_set_t *glyphs_requested;
 
   // Tables which should not be processed, just pass them through.
-  hb_set_t *no_subset_tables;
+  hb_set_t no_subset_tables;
 
   // Tables which should be dropped.
   hb_set_t drop_tables;

src/hb-subset.cc

@@ -168,11 +168,11 @@ _get_table_tags (const hb_subset_plan_t* plan,
       hb_concat (
           + hb_array (known_tables)
           | hb_filter ([&] (hb_tag_t tag) {
-            return !_table_is_empty (plan->source, tag) && !plan->no_subset_tables->has (tag);
+            return !_table_is_empty (plan->source, tag) && !plan->no_subset_tables.has (tag);
           })
           | hb_map ([] (hb_tag_t tag) -> hb_tag_t { return tag; }),
 
-          plan->no_subset_tables->iter ()
+          plan->no_subset_tables.iter ()
           | hb_filter([&] (hb_tag_t tag) {
             return !_table_is_empty (plan->source, tag);
           }));
@@ -424,7 +424,7 @@ _subset_table (hb_subset_plan_t *plan,
 	       hb_vector_t<char> &buf,
 	       hb_tag_t tag)
 {
-  if (plan->no_subset_tables->has (tag)) {
+  if (plan->no_subset_tables.has (tag)) {
     return _passthrough (plan, tag);
   }