[subset] drop hint tables if so flagged. Still need to dump glyf instructions.

src/hb-subset-plan.cc

@@ -191,6 +191,7 @@ hb_subset_plan_create (hb_face_t           *face,
   plan->gids_to_retain_sorted.init();
   plan->source = hb_face_reference (face);
   plan->dest = hb_subset_face_create ();
+  plan->drop_hints = input->drop_hints;
 
   _populate_codepoints (input->unicodes, plan->codepoints);
   _populate_gids_to_retain (face,

src/hb-subset-plan.hh

@@ -37,6 +37,8 @@ struct hb_subset_plan_t {
   hb_object_header_t header;
   ASSERT_POD ();
 
+  hb_bool_t drop_hints;
+
   // TODO(Q1) actual map, drop this crap
   // Look at me ma, I'm a poor mans map codepoint : new gid
   // codepoints is sorted and aligned with gids_to_retain.

src/hb-subset-private.hh

@@ -43,7 +43,7 @@ struct hb_subset_input_t {
   hb_set_t *unicodes;
   hb_set_t *glyphs;
 
-  hb_bool_t retain_hints;
+  hb_bool_t drop_hints;
   /* TODO
    *
    * features

src/hb-subset.cc

@@ -268,9 +268,16 @@ _subset_table (hb_subset_plan_t *plan,
 }
 
 static bool
-_should_drop_table(hb_tag_t tag)
+_should_drop_table(hb_subset_plan_t *plan, hb_tag_t tag)
 {
     switch (tag) {
+      case HB_TAG ('c', 'v', 'a', 'r'): /* hint table, fallthrough */
+      case HB_TAG ('c', 'v', 't', ' '): /* hint table, fallthrough */
+      case HB_TAG ('f', 'p', 'g', 'm'): /* hint table, fallthrough */
+      case HB_TAG ('p', 'r', 'e', 'p'): /* hint table, fallthrough */
+      case HB_TAG ('h', 'd', 'm', 'x'): /* hint table, fallthrough */
+      case HB_TAG ('V', 'D', 'M', 'X'): /* hint table, fallthrough */
+        return plan->drop_hints;
       case HB_TAG ('G', 'D', 'E', 'F'): /* temporary */
       case HB_TAG ('G', 'P', 'O', 'S'): /* temporary */
       case HB_TAG ('G', 'S', 'U', 'B'): /* temporary */
@@ -307,7 +314,7 @@ hb_subset (hb_face_t *source,
     for (unsigned int i = 0; i < count; i++)
     {
       hb_tag_t tag = table_tags[i];
-      if (_should_drop_table(tag))
+      if (_should_drop_table(plan, tag))
       {
         DEBUG_MSG(SUBSET, nullptr, "drop %c%c%c%c", HB_UNTAG(tag));
         continue;

util/hb-subset.cc

@@ -90,7 +90,7 @@ struct subset_consumer_t
 
   void finish (const font_options_t *font_opts)
   {
-    input->retain_hints = subset_options.hinting;
+    input->drop_hints = subset_options.drop_hints;
 
     hb_subset_profile_t *subset_profile = hb_subset_profile_create();
     hb_face_t *face = hb_font_get_face (font);

util/options.cc

@@ -992,7 +992,7 @@ subset_options_t::add_options (option_parser_t *parser)
 {
   GOptionEntry entries[] =
   {
-    {"hinting", 0, 0, G_OPTION_ARG_NONE,  &this->hinting,   "Whether to retain or drop hints",   nullptr},
+    {"no-hinting", 0, 0, G_OPTION_ARG_NONE,  &this->drop_hints,   "Whether to drop hints",   nullptr},
     {nullptr}
   };
   parser->add_group (entries,

util/options.hh

@@ -653,14 +653,14 @@ struct subset_options_t : option_group_t
 {
   subset_options_t (option_parser_t *parser)
   {
-    hinting = true;
+    drop_hints = false;
 
     add_options (parser);
   }
 
   void add_options (option_parser_t *parser);
 
-  hb_bool_t hinting;
+  hb_bool_t drop_hints;
 };
 
 /* fallback implementation for scalbn()/scalbnf() for pre-2013 MSVC */