Update harfbuzz-ng to 0.9.14 from 0.9.10

third_party/harfbuzz-ng/src/hb-ot-layout-gsubgpos-private.hh

 /*
  * Copyright © 2007,2008,2009,2010  Red Hat, Inc.
  * Copyright © 2010,2012  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 20 matching lines @@
 
 #include "hb-buffer-private.hh"
 #include "hb-ot-layout-gdef-table.hh"
 #include "hb-set-private.hh"
 
 
 namespace OT {
 
 
 
-#define TRACE_PROCESS(this) \
+#define TRACE_DISPATCH(this) \
         hb_auto_trace_t<context_t::max_debug_depth, typename context_t::return_t> trace \
         (&c->debug_depth, c->get_name (), this, HB_FUNC, \
          "");
 
 
 #ifndef HB_DEBUG_CLOSURE
 #define HB_DEBUG_CLOSURE (HB_DEBUG+0)
 #endif
 
 #define TRACE_CLOSURE(this) \
         hb_auto_trace_t<HB_DEBUG_CLOSURE, hb_void_t> trace \
         (&c->debug_depth, c->get_name (), this, HB_FUNC, \
          "");
 
 struct hb_closure_context_t
 {
   inline const char *get_name (void) { return "CLOSURE"; }
   static const unsigned int max_debug_depth = HB_DEBUG_CLOSURE;
   typedef hb_void_t return_t;
   typedef return_t (*recurse_func_t) (hb_closure_context_t *c, unsigned int lookup_index);
   template <typename T>
-  inline return_t process (const T &obj) { obj.closure (this); return HB_VOID; }
+  inline return_t dispatch (const T &obj) { obj.closure (this); return HB_VOID; }
   static return_t default_return_value (void) { return HB_VOID; }
-  bool stop_sublookup_iteration (const return_t r HB_UNUSED) const { return false; }
+  bool stop_sublookup_iteration (return_t r HB_UNUSED) const { return false; }
   return_t recurse (unsigned int lookup_index)
   {
     if (unlikely (nesting_level_left == 0 || !recurse_func))
       return default_return_value ();
 
     nesting_level_left--;
     recurse_func (this, lookup_index);
     nesting_level_left++;
     return HB_VOID;
   }
@@ skipping 26 matching lines @@
         hb_auto_trace_t<HB_DEBUG_WOULD_APPLY, bool> trace \
         (&c->debug_depth, c->get_name (), this, HB_FUNC, \
          "%d glyphs", c->len);
 
 struct hb_would_apply_context_t
 {
   inline const char *get_name (void) { return "WOULD_APPLY"; }
   static const unsigned int max_debug_depth = HB_DEBUG_WOULD_APPLY;
   typedef bool return_t;
   template <typename T>
-  inline return_t process (const T &obj) { return obj.would_apply (this); }
+  inline return_t dispatch (const T &obj) { return obj.would_apply (this); }
   static return_t default_return_value (void) { return false; }
-  bool stop_sublookup_iteration (const return_t r) const { return r; }
+  bool stop_sublookup_iteration (return_t r) const { return r; }
 
   hb_face_t *face;
   const hb_codepoint_t *glyphs;
   unsigned int len;
   bool zero_context;
   unsigned int debug_depth;
 
   hb_would_apply_context_t (hb_face_t *face_,
                             const hb_codepoint_t *glyphs_,
                             unsigned int len_,
@@ skipping 16 matching lines @@
         (&c->debug_depth, c->get_name (), this, HB_FUNC, \
          "");
 
 struct hb_collect_glyphs_context_t
 {
   inline const char *get_name (void) { return "COLLECT_GLYPHS"; }
   static const unsigned int max_debug_depth = HB_DEBUG_COLLECT_GLYPHS;
   typedef hb_void_t return_t;
   typedef return_t (*recurse_func_t) (hb_collect_glyphs_context_t *c, unsigned int lookup_index);
   template <typename T>
-  inline return_t process (const T &obj) { obj.collect_glyphs (this); return HB_VOID; }
+  inline return_t dispatch (const T &obj) { obj.collect_glyphs (this); return HB_VOID; }
   static return_t default_return_value (void) { return HB_VOID; }
-  bool stop_sublookup_iteration (const return_t r HB_UNUSED) const { return false; }
+  bool stop_sublookup_iteration (return_t r HB_UNUSED) const { return false; }
   return_t recurse (unsigned int lookup_index)
   {
     if (unlikely (nesting_level_left == 0 || !recurse_func))
       return default_return_value ();
 
     /* Note that GPOS sets recurse_func to NULL already, so it doesn't get
      * past the previous check.  For GSUB, we only want to collect the output
      * glyphs in the recursion.  If output is not requested, we can go home now. */
 
     if (output == hb_set_get_empty ())
@@ skipping 43 matching lines @@
 };
 
 
 
 struct hb_get_coverage_context_t
 {
   inline const char *get_name (void) { return "GET_COVERAGE"; }
   static const unsigned int max_debug_depth = 0;
   typedef const Coverage &return_t;
   template <typename T>
-  inline return_t process (const T &obj) { return obj.get_coverage (); }
+  inline return_t dispatch (const T &obj) { return obj.get_coverage (); }
   static return_t default_return_value (void) { return Null(Coverage); }
 
   hb_get_coverage_context_t (void) :
                             debug_depth (0) {}
 
   unsigned int debug_depth;
 };
 
 
 
 #ifndef HB_DEBUG_APPLY
 #define HB_DEBUG_APPLY (HB_DEBUG+0)
 #endif
 
 #define TRACE_APPLY(this) \
         hb_auto_trace_t<HB_DEBUG_APPLY, bool> trace \
         (&c->debug_depth, c->get_name (), this, HB_FUNC, \
          "idx %d codepoint %u", c->buffer->idx, c->buffer->cur().codepoint);
 
 struct hb_apply_context_t
 {
   inline const char *get_name (void) { return "APPLY"; }
   static const unsigned int max_debug_depth = HB_DEBUG_APPLY;
   typedef bool return_t;
   typedef return_t (*recurse_func_t) (hb_apply_context_t *c, unsigned int lookup_index);
   template <typename T>
-  inline return_t process (const T &obj) { return obj.apply (this); }
+  inline return_t dispatch (const T &obj) { return obj.apply (this); }
   static return_t default_return_value (void) { return false; }
-  bool stop_sublookup_iteration (const return_t r) const { return r; }
+  bool stop_sublookup_iteration (return_t r) const { return r; }
   return_t recurse (unsigned int lookup_index)
   {
     if (unlikely (nesting_level_left == 0 || !recurse_func))
       return default_return_value ();
 
     nesting_level_left--;
     bool ret = recurse_func (this, lookup_index);
     nesting_level_left++;
     return ret;
   }
 
+  unsigned int table_index; /* GSUB/GPOS */
   hb_font_t *font;
   hb_face_t *face;
   hb_buffer_t *buffer;
   hb_direction_t direction;
   hb_mask_t lookup_mask;
+  bool auto_zwj;
   recurse_func_t recurse_func;
   unsigned int nesting_level_left;
   unsigned int lookup_props;
-  unsigned int property; /* propety of first glyph */
   const GDEF &gdef;
   bool has_glyph_classes;
   unsigned int debug_depth;
 
 
-  hb_apply_context_t (hb_font_t *font_,
+  hb_apply_context_t (unsigned int table_index_,
+                      hb_font_t *font_,
                       hb_buffer_t *buffer_,
-                      hb_mask_t lookup_mask_) :
+                      hb_mask_t lookup_mask_,
+                      bool auto_zwj_) :
+                        table_index (table_index_),
                         font (font_), face (font->face), buffer (buffer_),
                         direction (buffer_->props.direction),
                         lookup_mask (lookup_mask_),
+                        auto_zwj (auto_zwj_),
                         recurse_func (NULL),
                         nesting_level_left (MAX_NESTING_LEVEL),
-                        lookup_props (0), property (0),
+                        lookup_props (0),
                         gdef (*hb_ot_layout_from_face (face)->gdef),
                         has_glyph_classes (gdef.has_glyph_classes ()),
                         debug_depth (0) {}
 
-  void set_recurse_func (recurse_func_t func) { recurse_func = func; }
-  void set_lookup_props (unsigned int lookup_props_) { lookup_props = lookup_props_; }
-  void set_lookup (const Lookup &l) { lookup_props = l.get_props (); }
-
-  struct mark_skipping_forward_iterator_t
+  inline void set_recurse_func (recurse_func_t func) { recurse_func = func; }
+  inline void set_lookup_props (unsigned int lookup_props_) { lookup_props = lookup_props_; }
+  inline void set_lookup (const Lookup &l) { lookup_props = l.get_props (); }
+
+  struct matcher_t
   {
-    inline mark_skipping_forward_iterator_t (hb_apply_context_t *c_,
-                                             unsigned int start_index_,
-                                             unsigned int num_items_,
-                                             bool context_match = false)
-    {
-      c = c_;
-      idx = start_index_;
-      num_items = num_items_;
-      mask = context_match ? -1 : c->lookup_mask;
-      syllable = context_match ? 0 : c->buffer->cur().syllable ();
-      end = c->buffer->len;
-    }
-    inline bool has_no_chance (void) const
-    {
-      return unlikely (num_items && idx + num_items >= end);
-    }
-    inline void reject (void)
-    {
-      num_items++;
-    }
-    inline bool next (unsigned int *property_out,
-                      unsigned int  lookup_props)
+    inline matcher_t (void) :
+             lookup_props (0),
+             ignore_zwnj (false),
+             ignore_zwj (false),
+             mask (-1),
+#define arg1(arg) (arg) /* Remove the macro to see why it's needed! */
+             syllable arg1(0),
+#undef arg1
+             match_func (NULL),
+             match_data (NULL) {};
+
+    typedef bool (*match_func_t) (hb_codepoint_t glyph_id, const USHORT &value, const void *data);
+
+    inline void set_ignore_zwnj (bool ignore_zwnj_) { ignore_zwnj = ignore_zwnj_; }
+    inline void set_ignore_zwj (bool ignore_zwj_) { ignore_zwj = ignore_zwj_; }
+    inline void set_lookup_props (unsigned int lookup_props_) { lookup_props = lookup_props_; }
+    inline void set_mask (hb_mask_t mask_) { mask = mask_; }
+    inline void set_syllable (uint8_t syllable_)  { syllable = syllable_; }
+    inline void set_match_func (match_func_t match_func_,
+                                const void *match_data_)
+    { match_func = match_func_; match_data = match_data_; }
+
+    enum may_match_t {
+      MATCH_NO,
+      MATCH_YES,
+      MATCH_MAYBE
+    };
+
+    inline may_match_t may_match (const hb_glyph_info_t &info,
+                                  const USHORT          *glyph_data) const
+    {
+      if (!(info.mask & mask) ||
+          (syllable && syllable != info.syllable ()))
+        return MATCH_NO;
+
+      if (match_func)
+        return match_func (info.codepoint, *glyph_data, match_data) ? MATCH_YES : MATCH_NO;
+
+      return MATCH_MAYBE;
+    }
+
+    enum may_skip_t {
+      SKIP_NO,
+      SKIP_YES,
+      SKIP_MAYBE
+    };
+
+    inline may_skip_t
+    may_skip (const hb_apply_context_t *c,
+              const hb_glyph_info_t    &info) const
+    {
+      unsigned int property;
+
+      property = info.glyph_props();
+
+      if (!c->match_properties (info.codepoint, property, lookup_props))
+        return SKIP_YES;
+
+      if (unlikely (_hb_glyph_info_is_default_ignorable (&info) &&
+                    (ignore_zwnj || !_hb_glyph_info_is_zwnj (&info)) &&
+                    (ignore_zwj || !_hb_glyph_info_is_zwj (&info)) &&
+                    !is_a_ligature (info)))
+        return SKIP_MAYBE;
+
+      return SKIP_NO;
+    }
+
+    protected:
+    unsigned int lookup_props;
+    bool ignore_zwnj;
+    bool ignore_zwj;
+    hb_mask_t mask;
+    uint8_t syllable;
+    match_func_t match_func;
+    const void *match_data;
+  };
+
+  struct skipping_forward_iterator_t
+  {
+    inline skipping_forward_iterator_t (hb_apply_context_t *c_,
+                                        unsigned int start_index_,
+                                        unsigned int num_items_,
+                                        bool context_match = false) :
+                                         idx (start_index_),
+                                         c (c_),
+                                         match_glyph_data (NULL),
+                                         num_items (num_items_),
+                                         end (c->buffer->len)
+    {
+      matcher.set_lookup_props (c->lookup_props);
+      /* Ignore ZWNJ if we are matching GSUB context, or matching GPOS. */
+      matcher.set_ignore_zwnj (context_match || c->table_index == 1);
+      /* Ignore ZWJ if we are matching GSUB context, or matching GPOS, or if asked to. */
+      matcher.set_ignore_zwj (context_match || c->table_index == 1 || c->auto_zwj);
+      if (!context_match)
+        matcher.set_mask (c->lookup_mask);
+      matcher.set_syllable (start_index_ == c->buffer->idx ? c->buffer->cur().syllable () : 0);
+    }
+    inline void set_lookup_props (unsigned int lookup_props) { matcher.set_lookup_props (lookup_props); }
+    inline void set_syllable (unsigned int syllable) { matcher.set_syllable (syllable); }
+    inline void set_match_func (matcher_t::match_func_t match_func,
+                                const void *match_data,
+                                const USHORT glyph_data[])
+    {
+      matcher.set_match_func (match_func, match_data);
+      match_glyph_data = glyph_data;
+    }
+
+    inline bool has_no_chance (void) const { return unlikely (num_items && idx + num_items >= end); }
+    inline void reject (void) { num_items++; match_glyph_data--; }
+    inline bool next (void)
     {
       assert (num_items > 0);
-      do
+      while (!has_no_chance ())
       {
-        if (has_no_chance ())
+        idx++;
+        const hb_glyph_info_t &info = c->buffer->info[idx];
+
+        matcher_t::may_skip_t skip = matcher.may_skip (c, info);
+        if (unlikely (skip == matcher_t::SKIP_YES))
+          continue;
+
+        matcher_t::may_match_t match = matcher.may_match (info, match_glyph_data);
+        if (match == matcher_t::MATCH_YES ||
+            (match == matcher_t::MATCH_MAYBE &&
+             skip == matcher_t::SKIP_NO))
+        {
+          num_items--;
+          match_glyph_data++;
+          return true;
+        }
+
+        if (skip == matcher_t::SKIP_NO)
           return false;
-        idx++;
-      } while (c->should_skip_mark (&c->buffer->info[idx], lookup_props, property_out));
-      num_items--;
-      return (c->buffer->info[idx].mask & mask) && (!syllable || syllable == c->buffer->info[idx].syllable ());
-    }
-    inline bool next (unsigned int *property_out = NULL)
-    {
-      return next (property_out, c->lookup_props);
+      }
+      return false;
     }
 
     unsigned int idx;
     protected:
     hb_apply_context_t *c;
+    matcher_t matcher;
+    const USHORT *match_glyph_data;
+
     unsigned int num_items;
-    hb_mask_t mask;
-    uint8_t syllable;
     unsigned int end;
   };
 
-  struct mark_skipping_backward_iterator_t
+  struct skipping_backward_iterator_t
   {
-    inline mark_skipping_backward_iterator_t (hb_apply_context_t *c_,
-                                              unsigned int start_index_,
-                                              unsigned int num_items_,
-                                              hb_mask_t mask_ = 0,
-                                              bool match_syllable_ = true)
-    {
-      c = c_;
-      idx = start_index_;
-      num_items = num_items_;
-      mask = mask_ ? mask_ : c->lookup_mask;
-      syllable = match_syllable_ ? c->buffer->cur().syllable () : 0;
-    }
-    inline bool has_no_chance (void) const
-    {
-      return unlikely (idx < num_items);
-    }
-    inline void reject (void)
-    {
-      num_items++;
-    }
-    inline bool prev (unsigned int *property_out,
-                      unsigned int  lookup_props)
+    inline skipping_backward_iterator_t (hb_apply_context_t *c_,
+                                         unsigned int start_index_,
+                                         unsigned int num_items_,
+                                         bool context_match = false) :
+                                          idx (start_index_),
+                                          c (c_),
+                                          match_glyph_data (NULL),
+                                          num_items (num_items_)
+    {
+      matcher.set_lookup_props (c->lookup_props);
+      /* Ignore ZWNJ if we are matching GSUB context, or matching GPOS. */
+      matcher.set_ignore_zwnj (context_match || c->table_index == 1);
+      /* Ignore ZWJ if we are matching GSUB context, or matching GPOS, or if asked to. */
+      matcher.set_ignore_zwj (context_match || c->table_index == 1 || c->auto_zwj);
+      if (!context_match)
+        matcher.set_mask (c->lookup_mask);
+      matcher.set_syllable (start_index_ == c->buffer->idx ? c->buffer->cur().syllable () : 0);
+    }
+    inline void set_lookup_props (unsigned int lookup_props) { matcher.set_lookup_props (lookup_props); }
+    inline void set_syllable (unsigned int syllable) { matcher.set_syllable (syllable); }
+    inline void set_match_func (matcher_t::match_func_t match_func,
+                                const void *match_data,
+                                const USHORT glyph_data[])
+    {
+      matcher.set_match_func (match_func, match_data);
+      match_glyph_data = glyph_data;
+    }
+
+    inline bool has_no_chance (void) const { return unlikely (idx < num_items); }
+    inline void reject (void) { num_items++; }
+    inline bool prev (void)
     {
       assert (num_items > 0);
-      do
+      while (!has_no_chance ())
       {
-        if (has_no_chance ())
+        idx--;
+        const hb_glyph_info_t &info = c->buffer->out_info[idx];
+
+        matcher_t::may_skip_t skip = matcher.may_skip (c, info);
+
+        if (unlikely (skip == matcher_t::SKIP_YES))
+          continue;
+
+        matcher_t::may_match_t match = matcher.may_match (info, match_glyph_data);
+        if (match == matcher_t::MATCH_YES ||
+            (match == matcher_t::MATCH_MAYBE &&
+             skip == matcher_t::SKIP_NO))
+        {
+          num_items--;
+          match_glyph_data++;
+          return true;
+        }
+
+        if (skip == matcher_t::SKIP_NO)
           return false;
-        idx--;
-      } while (c->should_skip_mark (&c->buffer->out_info[idx], lookup_props, property_out));
-      num_items--;
-      return (c->buffer->out_info[idx].mask & mask) && (!syllable || syllable == c->buffer->out_info[idx].syllable ());
-    }
-    inline bool prev (unsigned int *property_out = NULL)
-    {
-      return prev (property_out, c->lookup_props);
+      }
+      return false;
     }
 
     unsigned int idx;
     protected:
     hb_apply_context_t *c;
+    matcher_t matcher;
+    const USHORT *match_glyph_data;
+
     unsigned int num_items;
-    hb_mask_t mask;
-    uint8_t syllable;
   };
 
   inline bool
   match_properties_mark (hb_codepoint_t  glyph,
                          unsigned int    glyph_props,
                          unsigned int    lookup_props) const
   {
     /* If using mark filtering sets, the high short of
      * lookup_props has the set index.
      */
@@ skipping 22 matching lines @@
       return false;
 
     if (unlikely (glyph_props & HB_OT_LAYOUT_GLYPH_PROPS_MARK))
       return match_properties_mark (glyph, glyph_props, lookup_props);
 
     return true;
   }
 
   inline bool
   check_glyph_property (hb_glyph_info_t *info,
-                        unsigned int  lookup_props,
-                        unsigned int *property_out) const
+                        unsigned int  lookup_props) const
   {
     unsigned int property;
 
     property = info->glyph_props();
-    *property_out = property;
 
     return match_properties (info->codepoint, property, lookup_props);
   }
 
-  inline bool
-  should_skip_mark (hb_glyph_info_t *info,
-                   unsigned int  lookup_props,
-                   unsigned int *property_out) const
-  {
-    unsigned int property;
-
-    property = info->glyph_props();
-    if (property_out)
-      *property_out = property;
-
-    /* If it's a mark, skip it if we don't accept it. */
-    if (unlikely (property & HB_OT_LAYOUT_GLYPH_PROPS_MARK))
-      return !match_properties (info->codepoint, property, lookup_props);
-
-    /* If not a mark, don't skip. */
-    return false;
-  }
-
-
-  inline bool should_mark_skip_current_glyph (void) const
-  {
-    return should_skip_mark (&buffer->cur(), lookup_props, NULL);
-  }
-
   inline void set_class (hb_codepoint_t glyph_index, unsigned int class_guess) const
   {
     if (likely (has_glyph_classes))
       buffer->cur().glyph_props() = gdef.get_glyph_props (glyph_index);
     else if (class_guess)
       buffer->cur().glyph_props() = class_guess;
   }
 
   inline void output_glyph (hb_codepoint_t glyph_index,
                             unsigned int class_guess = 0) const
@@ skipping 123 matching lines @@
                                 unsigned int count, /* Including the first glyph (not matched) */
                                 const USHORT input[], /* Array of input values--start with second glyph */
                                 match_func_t match_func,
                                 const void *match_data,
                                 unsigned int *end_offset = NULL,
                                 bool *p_is_mark_ligature = NULL,
                                 unsigned int *p_total_component_count = NULL)
 {
   TRACE_APPLY (NULL);
 
-  hb_apply_context_t::mark_skipping_forward_iterator_t skippy_iter (c, c->buffer->idx, count - 1);
+  hb_apply_context_t::skipping_forward_iterator_t skippy_iter (c, c->buffer->idx, count - 1);
+  skippy_iter.set_match_func (match_func, match_data, input);
   if (skippy_iter.has_no_chance ()) return TRACE_RETURN (false);
 
   /*
    * This is perhaps the trickiest part of OpenType...  Remarks:
    *
    * - If all components of the ligature were marks, we call this a mark ligature.
    *
    * - If there is no GDEF, and the ligature is NOT a mark ligature, we categorize
    *   it as a ligature glyph.
    *
    * - Ligatures cannot be formed across glyphs attached to different components
    *   of previous ligatures.  Eg. the sequence is LAM,SHADDA,LAM,FATHA,HEH, and
    *   LAM,LAM,HEH form a ligature, leaving SHADDA,FATHA next to eachother.
    *   However, it would be wrong to ligate that SHADDA,FATHA sequence.o
    *   There is an exception to this: If a ligature tries ligating with marks that
    *   belong to it itself, go ahead, assuming that the font designer knows what
    *   they are doing (otherwise it can break Indic stuff when a matra wants to
    *   ligate with a conjunct...)
    */
 
-  bool is_mark_ligature = !!(c->property & HB_OT_LAYOUT_GLYPH_PROPS_MARK);
+  bool is_mark_ligature = !!(c->buffer->cur().glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MARK);
 
   unsigned int total_component_count = 0;
   total_component_count += get_lig_num_comps (c->buffer->cur());
 
   unsigned int first_lig_id = get_lig_id (c->buffer->cur());
   unsigned int first_lig_comp = get_lig_comp (c->buffer->cur());
 
   for (unsigned int i = 1; i < count; i++)
   {
-    unsigned int property;
-
-    if (!skippy_iter.next (&property)) return TRACE_RETURN (false);
-
-    if (likely (!match_func (c->buffer->info[skippy_iter.idx].codepoint, input[i - 1], match_data))) return TRACE_RETURN (false);
+    if (!skippy_iter.next ()) return TRACE_RETURN (false);
 
     unsigned int this_lig_id = get_lig_id (c->buffer->info[skippy_iter.idx]);
     unsigned int this_lig_comp = get_lig_comp (c->buffer->info[skippy_iter.idx]);
 
     if (first_lig_id && first_lig_comp) {
       /* If first component was attached to a previous ligature component,
        * all subsequent components should be attached to the same ligature
        * component, otherwise we shouldn't ligate them. */
       if (first_lig_id != this_lig_id || first_lig_comp != this_lig_comp)
         return TRACE_RETURN (false);
     } else {
       /* If first component was NOT attached to a previous ligature component,
        * all subsequent components should also NOT be attached to any ligature
        * component, unless they are attached to the first component itself! */
       if (this_lig_id && this_lig_comp && (this_lig_id != first_lig_id))
         return TRACE_RETURN (false);
     }
 
-    is_mark_ligature = is_mark_ligature && (property & HB_OT_LAYOUT_GLYPH_PROPS_MARK);
+    is_mark_ligature = is_mark_ligature && (c->buffer->info[skippy_iter.idx].glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MARK);
     total_component_count += get_lig_num_comps (c->buffer->info[skippy_iter.idx]);
   }
 
   if (end_offset)
     *end_offset = skippy_iter.idx - c->buffer->idx + 1;
 
   if (p_is_mark_ligature)
     *p_is_mark_ligature = is_mark_ligature;
 
   if (p_total_component_count)
     *p_total_component_count = total_component_count;
 
   return TRACE_RETURN (true);
 }
 static inline void ligate_input (hb_apply_context_t *c,
                                  unsigned int count, /* Including the first glyph (not matched) */
-                                 const USHORT input[] HB_UNUSED, /* Array of input values--start with second glyph */
+                                 const USHORT input[], /* Array of input values--start with second glyph */
+                                 match_func_t match_func,
+                                 const void *match_data,
                                  hb_codepoint_t lig_glyph,
-                                 match_func_t match_func HB_UNUSED,
-                                 const void *match_data HB_UNUSED,
                                  bool is_mark_ligature,
                                  unsigned int total_component_count)
 {
+  hb_apply_context_t::skipping_forward_iterator_t skippy_iter (c, c->buffer->idx, count - 1);
+  skippy_iter.set_match_func (match_func, match_data, input);
+  if (skippy_iter.has_no_chance ()) return;
+
   /*
    * - If it *is* a mark ligature, we don't allocate a new ligature id, and leave
    *   the ligature to keep its old ligature id.  This will allow it to attach to
    *   a base ligature in GPOS.  Eg. if the sequence is: LAM,LAM,SHADDA,FATHA,HEH,
    *   and LAM,LAM,HEH for a ligature, they will leave SHADDA and FATHA wit a
    *   ligature id and component value of 2.  Then if SHADDA,FATHA form a ligature
    *   later, we don't want them to lose their ligature id/component, otherwise
    *   GPOS will fail to correctly position the mark ligature on top of the
    *   LAM,LAM,HEH ligature.  See:
    *     https://bugzilla.gnome.org/show_bug.cgi?id=676343
@@ skipping 20 matching lines @@
   unsigned int last_lig_id = get_lig_id (c->buffer->cur());
   unsigned int last_num_components = get_lig_num_comps (c->buffer->cur());
   unsigned int components_so_far = last_num_components;
 
   if (!is_mark_ligature)
     set_lig_props_for_ligature (c->buffer->cur(), lig_id, total_component_count);
   c->replace_glyph (lig_glyph, klass);
 
   for (unsigned int i = 1; i < count; i++)
   {
-    while (c->should_mark_skip_current_glyph ())
+    if (!skippy_iter.next ()) return;
+
+    while (c->buffer->idx < skippy_iter.idx)
     {
       if (!is_mark_ligature) {
         unsigned int new_lig_comp = components_so_far - last_num_components +
                                     MIN (MAX (get_lig_comp (c->buffer->cur()), 1u), last_num_components);
         set_lig_props_for_mark (c->buffer->cur(), lig_id, new_lig_comp);
       }
       c->buffer->next_glyph ();
     }
 
     last_lig_id = get_lig_id (c->buffer->cur());
@@ skipping 18 matching lines @@
 }
 
 static inline bool match_backtrack (hb_apply_context_t *c,
                                     unsigned int count,
                                     const USHORT backtrack[],
                                     match_func_t match_func,
                                     const void *match_data)
 {
   TRACE_APPLY (NULL);
 
-  hb_apply_context_t::mark_skipping_backward_iterator_t skippy_iter (c, c->buffer->backtrack_len (), count, true);
-  if (skippy_iter.has_no_chance ())
-    return TRACE_RETURN (false);
+  hb_apply_context_t::skipping_backward_iterator_t skippy_iter (c, c->buffer->backtrack_len (), count, true);
+  skippy_iter.set_match_func (match_func, match_data, backtrack);
+  if (skippy_iter.has_no_chance ()) return TRACE_RETURN (false);
 
   for (unsigned int i = 0; i < count; i++)
-  {
     if (!skippy_iter.prev ())
       return TRACE_RETURN (false);
 
-    if (likely (!match_func (c->buffer->out_info[skippy_iter.idx].codepoint, backtrack[i], match_data)))
-      return TRACE_RETURN (false);
-  }
-
   return TRACE_RETURN (true);
 }
 
 static inline bool match_lookahead (hb_apply_context_t *c,
                                     unsigned int count,
                                     const USHORT lookahead[],
                                     match_func_t match_func,
                                     const void *match_data,
                                     unsigned int offset)
 {
   TRACE_APPLY (NULL);
 
-  hb_apply_context_t::mark_skipping_forward_iterator_t skippy_iter (c, c->buffer->idx + offset - 1, count, true);
-  if (skippy_iter.has_no_chance ())
-    return TRACE_RETURN (false);
+  hb_apply_context_t::skipping_forward_iterator_t skippy_iter (c, c->buffer->idx + offset - 1, count, true);
+  skippy_iter.set_match_func (match_func, match_data, lookahead);
+  if (skippy_iter.has_no_chance ()) return TRACE_RETURN (false);
 
   for (unsigned int i = 0; i < count; i++)
-  {
     if (!skippy_iter.next ())
       return TRACE_RETURN (false);
 
-    if (likely (!match_func (c->buffer->info[skippy_iter.idx].codepoint, lookahead[i], match_data)))
-      return TRACE_RETURN (false);
-  }
-
   return TRACE_RETURN (true);
 }
 
 
 
 struct LookupRecord
 {
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this));
@@ skipping 12 matching lines @@
 static inline void recurse_lookups (context_t *c,
                                     unsigned int lookupCount,
                                     const LookupRecord lookupRecord[] /* Array of LookupRecords--in design order */)
 {
   for (unsigned int i = 0; i < lookupCount; i++)
     c->recurse (lookupRecord->lookupListIndex);
 }
 
 static inline bool apply_lookup (hb_apply_context_t *c,
                                  unsigned int count, /* Including the first glyph */
+                                 const USHORT input[], /* Array of input values--start with second glyph */
+                                 match_func_t match_func,
+                                 const void *match_data,
                                  unsigned int lookupCount,
                                  const LookupRecord lookupRecord[] /* Array of LookupRecords--in design order */)
 {
   TRACE_APPLY (NULL);
 
   unsigned int end = c->buffer->len;
   if (unlikely (count == 0 || c->buffer->idx + count > end))
     return TRACE_RETURN (false);
 
   /* TODO We don't support lookupRecord arrays that are not increasing:
    *      Should be easy for in_place ones at least. */
 
   /* Note: If sublookup is reverse, it will underflow after the first loop
    * and we jump out of it.  Not entirely disastrous.  So we don't check
    * for reverse lookup here.
    */
-  for (unsigned int i = 0; i < count; /* NOP */)
+
+  hb_apply_context_t::skipping_forward_iterator_t skippy_iter (c, c->buffer->idx, count - 1);
+  skippy_iter.set_match_func (match_func, match_data, input);
+  uint8_t syllable = c->buffer->cur().syllable();
+
+  unsigned int i = 0;
+  if (lookupCount && 0 == lookupRecord->sequenceIndex)
   {
-    if (unlikely (c->buffer->idx == end))
-      return TRACE_RETURN (true);
-    while (c->should_mark_skip_current_glyph ())
+    unsigned int old_pos = c->buffer->idx;
+
+    /* Apply a lookup */
+    bool done = c->recurse (lookupRecord->lookupListIndex);
+
+    lookupRecord++;
+    lookupCount--;
+    /* Err, this is wrong if the lookup jumped over some glyphs */
+    i += c->buffer->idx - old_pos;
+
+    if (!done)
+      goto not_applied;
+    else
     {
-      /* No lookup applied for this index */
+      /* Reinitialize iterator. */
+      hb_apply_context_t::skipping_forward_iterator_t tmp (c, c->buffer->idx - 1, count - i);
+      tmp.set_syllable (syllable);
+      skippy_iter = tmp;
+    }
+  }
+  else
+  {
+  not_applied:
+    /* No lookup applied for this index */
+    c->buffer->next_glyph ();
+    i++;
+  }
+  while (i < count)
+  {
+    if (!skippy_iter.next ()) return TRACE_RETURN (true);
+    while (c->buffer->idx < skippy_iter.idx)
       c->buffer->next_glyph ();
-      if (unlikely (c->buffer->idx == end))
-        return TRACE_RETURN (true);
-    }
 
     if (lookupCount && i == lookupRecord->sequenceIndex)
     {
       unsigned int old_pos = c->buffer->idx;
 
       /* Apply a lookup */
       bool done = c->recurse (lookupRecord->lookupListIndex);
 
       lookupRecord++;
       lookupCount--;
       /* Err, this is wrong if the lookup jumped over some glyphs */
       i += c->buffer->idx - old_pos;
-      if (unlikely (c->buffer->idx == end))
-        return TRACE_RETURN (true);
 
       if (!done)
-        goto not_applied;
+        goto not_applied2;
+      else
+      {
+        /* Reinitialize iterator. */
+        hb_apply_context_t::skipping_forward_iterator_t tmp (c, c->buffer->idx - 1, count - i);
+        tmp.set_syllable (syllable);
+        skippy_iter = tmp;
+      }
     }
     else
     {
-    not_applied:
+    not_applied2:
       /* No lookup applied for this index */
       c->buffer->next_glyph ();
       i++;
     }
   }
 
   return TRACE_RETURN (true);
 }
 
 
@@ skipping 61 matching lines @@
                                          unsigned int inputCount, /* Including the first glyph (not matched) */
                                          const USHORT input[], /* Array of input values--start with second glyph */
                                          unsigned int lookupCount,
                                          const LookupRecord lookupRecord[],
                                          ContextApplyLookupContext &lookup_context)
 {
   return match_input (c,
                       inputCount, input,
                       lookup_context.funcs.match, lookup_context.match_data)
       && apply_lookup (c,
-                       inputCount,
+                       inputCount, input,
+                       lookup_context.funcs.match, lookup_context.match_data,
                        lookupCount, lookupRecord);
 }
 
 struct Rule
 {
   inline void closure (hb_closure_context_t *c, ContextClosureLookupContext &lookup_context) const
   {
     TRACE_CLOSURE (this);
     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (input, input[0].static_size * (inputCount ? inputCount - 1 : 0));
     context_closure_lookup (c,
@@ skipping 374 matching lines @@
                                          * table in glyph sequence order */
   LookupRecord  lookupRecordX[VAR];     /* Array of LookupRecords--in
                                          * design order */
   public:
   DEFINE_SIZE_ARRAY2 (6, coverage, lookupRecordX);
 };
 
 struct Context
 {
   template <typename context_t>
-  inline typename context_t::return_t process (context_t *c) const
+  inline typename context_t::return_t dispatch (context_t *c) const
   {
-    TRACE_PROCESS (this);
+    TRACE_DISPATCH (this);
     switch (u.format) {
-    case 1: return TRACE_RETURN (c->process (u.format1));
-    case 2: return TRACE_RETURN (c->process (u.format2));
-    case 3: return TRACE_RETURN (c->process (u.format3));
+    case 1: return TRACE_RETURN (c->dispatch (u.format1));
+    case 2: return TRACE_RETURN (c->dispatch (u.format2));
+    case 3: return TRACE_RETURN (c->dispatch (u.format3));
     default:return TRACE_RETURN (c->default_return_value ());
     }
   }
 
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
     switch (u.format) {
     case 1: return TRACE_RETURN (u.format1.sanitize (c));
     case 2: return TRACE_RETURN (u.format2.sanitize (c));
@@ skipping 114 matching lines @@
                       lookup_context.funcs.match, lookup_context.match_data[1],
                       &lookahead_offset)
       && match_backtrack (c,
                           backtrackCount, backtrack,
                           lookup_context.funcs.match, lookup_context.match_data[0])
       && match_lookahead (c,
                           lookaheadCount, lookahead,
                           lookup_context.funcs.match, lookup_context.match_data[2],
                           lookahead_offset)
       && apply_lookup (c,
-                       inputCount,
+                       inputCount, input,
+                       lookup_context.funcs.match, lookup_context.match_data[1],
                        lookupCount, lookupRecord);
 }
 
 struct ChainRule
 {
   inline void closure (hb_closure_context_t *c, ChainContextClosureLookupContext &lookup_context) const
   {
     TRACE_CLOSURE (this);
     const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
     const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
@@ skipping 453 matching lines @@
   ArrayOf<LookupRecord>
                 lookupX;                /* Array of LookupRecords--in
                                          * design order) */
   public:
   DEFINE_SIZE_MIN (10);
 };
 
 struct ChainContext
 {
   template <typename context_t>
-  inline typename context_t::return_t process (context_t *c) const
+  inline typename context_t::return_t dispatch (context_t *c) const
   {
-    TRACE_PROCESS (this);
+    TRACE_DISPATCH (this);
     switch (u.format) {
-    case 1: return TRACE_RETURN (c->process (u.format1));
-    case 2: return TRACE_RETURN (c->process (u.format2));
-    case 3: return TRACE_RETURN (c->process (u.format3));
+    case 1: return TRACE_RETURN (c->dispatch (u.format1));
+    case 2: return TRACE_RETURN (c->dispatch (u.format2));
+    case 3: return TRACE_RETURN (c->dispatch (u.format3));
     default:return TRACE_RETURN (c->default_return_value ());
     }
   }
 
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
     switch (u.format) {
     case 1: return TRACE_RETURN (u.format1.sanitize (c));
     case 2: return TRACE_RETURN (u.format2.sanitize (c));
@@ skipping 53 matching lines @@
 
   template <typename X>
   inline const X& get_subtable (void) const
   {
     unsigned int offset = get_offset ();
     if (unlikely (!offset)) return Null(typename T::LookupSubTable);
     return StructAtOffset<typename T::LookupSubTable> (this, offset);
   }
 
   template <typename context_t>
-  inline typename context_t::return_t process (context_t *c) const
+  inline typename context_t::return_t dispatch (context_t *c) const
   {
-    return get_subtable<typename T::LookupSubTable> ().process (c, get_type ());
+    return get_subtable<typename T::LookupSubTable> ().dispatch (c, get_type ());
   }
 
   inline bool sanitize_self (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
     switch (u.format) {
     case 1: return TRACE_RETURN (u.format1.sanitize (c));
     default:return TRACE_RETURN (true);
     }
   }
@@ skipping 73 matching lines @@
                 lookupList;     /* LookupList table */
   public:
   DEFINE_SIZE_STATIC (10);
 };
 
 
 } /* namespace OT */
 
 
 #endif /* HB_OT_LAYOUT_GSUBGPOS_PRIVATE_HH */