Roll HarfBuzz to 1.4.6

third_party/harfbuzz-ng/src/hb-ot-map-private.hh

 /*
  * Copyright © 2009,2010  Red Hat, Inc.
  * Copyright © 2010,2011,2012,2013  Google, Inc.
  *
  *  This is part of HarfBuzz, a text shaping library.
  *
  * Permission is hereby granted, without written agreement and without
  * license or royalty fees, to use, copy, modify, and distribute this
  * software and its documentation for any purpose, provided that the
  * above copyright notice and the following two paragraphs appear in
@@ skipping 95 matching lines @@
   inline void get_stage_lookups (unsigned int table_index, unsigned int stage,
                                  const struct lookup_map_t **plookups, unsigned int *lookup_count) const {
     if (unlikely (stage == (unsigned int) -1)) {
       *plookups = NULL;
       *lookup_count = 0;
       return;
     }
     assert (stage <= stages[table_index].len);
     unsigned int start = stage ? stages[table_index][stage - 1].last_lookup : 0;
     unsigned int end   = stage < stages[table_index].len ? stages[table_index][stage].last_lookup : lookups[table_index].len;
-    *plookups = &lookups[table_index][start];
+    *plookups = end == start ? NULL : &lookups[table_index][start];
     *lookup_count = end - start;
   }
 
   HB_INTERNAL void collect_lookups (unsigned int table_index, hb_set_t *lookups) const;
   template <typename Proxy>
   HB_INTERNAL inline void apply (const Proxy &proxy,
                                  const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
   HB_INTERNAL void substitute (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
   HB_INTERNAL void position (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
 
@@ skipping 103 matching lines @@
   private:
 
   unsigned int current_stage[2]; /* GSUB/GPOS */
   hb_prealloced_array_t<feature_info_t, 32> feature_infos;
   hb_prealloced_array_t<stage_info_t, 8> stages[2]; /* GSUB/GPOS */
 };
 
 
 
 #endif /* HB_OT_MAP_PRIVATE_HH */