Update bundled HarfBuzz copy to 0.9.39

Change-Id: I48d130a1639fef3b8ec2de5622848eb56fadc1c7 Reviewed-by: Lars Knoll <lars.knoll@digia.com>
author: Konstantin Ritt <ritt.ks@gmail.com> 2015-03-06 20:09:52 +0400
committer: Konstantin Ritt <ritt.ks@gmail.com> 2015-03-11 21:47:19 +0000
commit: b50e52ed162edbd857b8bb6f4d7d7639f6df119c (patch)
tree: 1fe2cc5bbf3a53eb99b3d6834fef12fdb9a1e40c
parent: 6ca406d43d63d4c6503f2213b6c8cf0f25f6af5e (diff)
22 files changed, 704 insertions, 639 deletions
diff --git a/src/3rdparty/harfbuzz-ng/NEWS b/src/3rdparty/harfbuzz-ng/NEWS
index 3a33bdf5cb..dbbfbba195 100644
--- a/src/3rdparty/harfbuzz-ng/NEWS
+++ b/src/3rdparty/harfbuzz-ng/NEWS
@@ -1,3 +1,13 @@
+Overview of changes leading to 0.9.39
+Wednesday, March 4, 2015
+=====================================
+
+- Critical hb-coretext fixes.
+- Optimizations and refactoring; no functional change
+  expected.
+- Misc build fixes.
+
+
 Overview of changes leading to 0.9.38
 Friday, January 23, 2015
 =====================================
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-buffer.cc b/src/3rdparty/harfbuzz-ng/src/hb-buffer.cc
index 0500aa23ce..942177cbd0 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-buffer.cc
+++ b/src/3rdparty/harfbuzz-ng/src/hb-buffer.cc
@@ -454,7 +454,7 @@ hb_buffer_t::reverse_range (unsigned int start,
     info[j] = t;
   }
 
-  if (pos) {
+  if (have_positions) {
     for (i = start, j = end - 1; i < j; i++, j--) {
       hb_glyph_position_t t;
 
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-open-file-private.hh b/src/3rdparty/harfbuzz-ng/src/hb-open-file-private.hh
index 7500c32f15..178bc7ccb8 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-open-file-private.hh
+++ b/src/3rdparty/harfbuzz-ng/src/hb-open-file-private.hh
@@ -53,7 +53,8 @@ struct TTCHeader;
 
 typedef struct TableRecord
 {
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this));
   }
@@ -102,7 +103,8 @@ typedef struct OffsetTable
   }
 
   public:
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) && c->check_array (tables, TableRecord::static_size, numTables));
   }
@@ -130,7 +132,8 @@ struct TTCHeaderVersion1
   inline unsigned int get_face_count (void) const { return table.len; }
   inline const OpenTypeFontFace& get_face (unsigned int i) const { return this+table[i]; }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (table.sanitize (c, this));
   }
@@ -169,7 +172,8 @@ struct TTCHeader
     }
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     if (unlikely (!u.header.version.sanitize (c))) return TRACE_RETURN (false);
     switch (u.header.version.major) {
@@ -233,7 +237,8 @@ struct OpenTypeFontFile
     }
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     if (unlikely (!u.tag.sanitize (c))) return TRACE_RETURN (false);
     switch (u.tag) {
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-open-type-private.hh b/src/3rdparty/harfbuzz-ng/src/hb-open-type-private.hh
index 477d9e28b2..75a0f568d1 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-open-type-private.hh
+++ b/src/3rdparty/harfbuzz-ng/src/hb-open-type-private.hh
@@ -179,10 +179,13 @@ struct hb_sanitize_context_t
   inline const char *get_name (void) { return "SANITIZE"; }
   static const unsigned int max_debug_depth = HB_DEBUG_SANITIZE;
   typedef bool return_t;
+  template <typename T, typename F>
+  inline bool may_dispatch (const T *obj, const F *format)
+  { return format->sanitize (this); }
   template <typename T>
   inline return_t dispatch (const T &obj) { return obj.sanitize (this); }
   static return_t default_return_value (void) { return true; }
-  bool stop_sublookup_iteration (const return_t r HB_UNUSED) const { return false; }
+  bool stop_sublookup_iteration (const return_t r) const { return !r; }
 
   inline void init (hb_blob_t *b)
   {
@@ -270,9 +273,9 @@ struct hb_sanitize_context_t
   }
 
   template <typename Type, typename ValueType>
-  inline bool try_set (Type *obj, const ValueType &v) {
+  inline bool try_set (const Type *obj, const ValueType &v) {
     if (this->may_edit (obj, obj->static_size)) {
-      obj->set (v);
+      const_cast<Type *> (obj)->set (v);
       return true;
     }
     return false;
@@ -546,12 +549,6 @@ struct BEInt<Type, 2>
     return (v[0] <<  8)
          + (v[1]      );
   }
-  inline bool operator == (const BEInt<Type, 2>& o) const
-  {
-    return v[0] == o.v[0]
-        && v[1] == o.v[1];
-  }
-  inline bool operator != (const BEInt<Type, 2>& o) const { return !(*this == o); }
   private: uint8_t v[2];
 };
 template <typename Type>
@@ -570,13 +567,6 @@ struct BEInt<Type, 3>
          + (v[1] <<  8)
          + (v[2]      );
   }
-  inline bool operator == (const BEInt<Type, 3>& o) const
-  {
-    return v[0] == o.v[0]
-        && v[1] == o.v[1]
-        && v[2] == o.v[2];
-  }
-  inline bool operator != (const BEInt<Type, 3>& o) const { return !(*this == o); }
   private: uint8_t v[3];
 };
 template <typename Type>
@@ -597,14 +587,6 @@ struct BEInt<Type, 4>
          + (v[2] <<  8)
          + (v[3]      );
   }
-  inline bool operator == (const BEInt<Type, 4>& o) const
-  {
-    return v[0] == o.v[0]
-        && v[1] == o.v[1]
-        && v[2] == o.v[2]
-        && v[3] == o.v[3];
-  }
-  inline bool operator != (const BEInt<Type, 4>& o) const { return !(*this == o); }
   private: uint8_t v[4];
 };
 
@@ -614,12 +596,19 @@ struct IntType
 {
   inline void set (Type i) { v.set (i); }
   inline operator Type(void) const { return v; }
-  inline bool operator == (const IntType<Type,Size> &o) const { return v == o.v; }
-  inline bool operator != (const IntType<Type,Size> &o) const { return v != o.v; }
+  inline bool operator == (const IntType<Type,Size> &o) const { return (Type) v == (Type) o.v; }
+  inline bool operator != (const IntType<Type,Size> &o) const { return !(*this == o); }
   static inline int cmp (const IntType<Type,Size> *a, const IntType<Type,Size> *b) { return b->cmp (*a); }
-  inline int cmp (IntType<Type,Size> va) const { Type a = va; Type b = v; return a < b ? -1 : a == b ? 0 : +1; }
-  inline int cmp (Type a) const { Type b = v; return a < b ? -1 : a == b ? 0 : +1; }
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline int cmp (Type a) const
+  {
+    Type b = v;
+    if (sizeof (Type) < sizeof (int))
+      return (int) a - (int) b;
+    else
+      return a < b ? -1 : a == b ? 0 : +1;
+  }
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (likely (c->check_struct (this)));
   }
@@ -646,7 +635,8 @@ typedef USHORT UFWORD;
  * 1904. The value is represented as a signed 64-bit integer. */
 struct LONGDATETIME
 {
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (likely (c->check_struct (this)));
   }
@@ -670,7 +660,10 @@ struct Tag : ULONG
 DEFINE_NULL_DATA (Tag, "    ");
 
 /* Glyph index number, same as uint16 (length = 16 bits) */
-typedef USHORT GlyphID;
+struct GlyphID : USHORT {
+  static inline int cmp (const GlyphID *a, const GlyphID *b) { return b->USHORT::cmp (*a); }
+  inline int cmp (hb_codepoint_t a) const { return (int) a - (int) *this; }
+};
 
 /* Script/language-system/feature index */
 struct Index : USHORT {
@@ -719,7 +712,8 @@ struct FixedVersion
 {
   inline uint32_t to_int (void) const { return (major << 16) + minor; }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this));
   }
@@ -747,33 +741,35 @@ struct OffsetTo : Offset<OffsetType>
     return StructAtOffset<Type> (base, offset);
   }
 
-  inline Type& serialize (hb_serialize_context_t *c, void *base)
+  inline Type& serialize (hb_serialize_context_t *c, const void *base)
   {
     Type *t = c->start_embed<Type> ();
     this->set ((char *) t - (char *) base); /* TODO(serialize) Overflow? */
     return *t;
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c, void *base) {
+  inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
     TRACE_SANITIZE (this);
     if (unlikely (!c->check_struct (this))) return TRACE_RETURN (false);
     unsigned int offset = *this;
     if (unlikely (!offset)) return TRACE_RETURN (true);
-    Type &obj = StructAtOffset<Type> (base, offset);
+    const Type &obj = StructAtOffset<Type> (base, offset);
     return TRACE_RETURN (likely (obj.sanitize (c)) || neuter (c));
   }
   template <typename T>
-  inline bool sanitize (hb_sanitize_context_t *c, void *base, T user_data) {
+  inline bool sanitize (hb_sanitize_context_t *c, const void *base, T user_data) const
+  {
     TRACE_SANITIZE (this);
     if (unlikely (!c->check_struct (this))) return TRACE_RETURN (false);
     unsigned int offset = *this;
     if (unlikely (!offset)) return TRACE_RETURN (true);
-    Type &obj = StructAtOffset<Type> (base, offset);
+    const Type &obj = StructAtOffset<Type> (base, offset);
     return TRACE_RETURN (likely (obj.sanitize (c, user_data)) || neuter (c));
   }
 
   /* Set the offset to Null */
-  inline bool neuter (hb_sanitize_context_t *c) {
+  inline bool neuter (hb_sanitize_context_t *c) const {
     return c->try_set (this, 0);
   }
   DEFINE_SIZE_STATIC (sizeof(OffsetType));
@@ -838,7 +834,8 @@ struct ArrayOf
     return TRACE_RETURN (true);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     if (unlikely (!sanitize_shallow (c))) return TRACE_RETURN (false);
 
@@ -853,7 +850,8 @@ struct ArrayOf
 
     return TRACE_RETURN (true);
   }
-  inline bool sanitize (hb_sanitize_context_t *c, void *base) {
+  inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
     TRACE_SANITIZE (this);
     if (unlikely (!sanitize_shallow (c))) return TRACE_RETURN (false);
     unsigned int count = len;
@@ -863,7 +861,8 @@ struct ArrayOf
     return TRACE_RETURN (true);
   }
   template <typename T>
-  inline bool sanitize (hb_sanitize_context_t *c, void *base, T user_data) {
+  inline bool sanitize (hb_sanitize_context_t *c, const void *base, T user_data) const
+  {
     TRACE_SANITIZE (this);
     if (unlikely (!sanitize_shallow (c))) return TRACE_RETURN (false);
     unsigned int count = len;
@@ -884,7 +883,8 @@ struct ArrayOf
   }
 
   private:
-  inline bool sanitize_shallow (hb_sanitize_context_t *c) {
+  inline bool sanitize_shallow (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) && c->check_array (this, Type::static_size, len));
   }
@@ -910,12 +910,14 @@ struct OffsetListOf : OffsetArrayOf<Type>
     return this+this->array[i];
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (OffsetArrayOf<Type>::sanitize (c, this));
   }
   template <typename T>
-  inline bool sanitize (hb_sanitize_context_t *c, T user_data) {
+  inline bool sanitize (hb_sanitize_context_t *c, T user_data) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (OffsetArrayOf<Type>::sanitize (c, this, user_data));
   }
@@ -949,12 +951,14 @@ struct HeadlessArrayOf
     return TRACE_RETURN (true);
   }
 
-  inline bool sanitize_shallow (hb_sanitize_context_t *c) {
+  inline bool sanitize_shallow (hb_sanitize_context_t *c) const
+  {
     return c->check_struct (this)
 	&& c->check_array (this, Type::static_size, len);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     if (unlikely (!sanitize_shallow (c))) return TRACE_RETURN (false);
 
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-ot-cmap-table.hh b/src/3rdparty/harfbuzz-ng/src/hb-ot-cmap-table.hh
index d53141157d..0482312553 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-ot-cmap-table.hh
+++ b/src/3rdparty/harfbuzz-ng/src/hb-ot-cmap-table.hh
@@ -51,7 +51,8 @@ struct CmapSubtableFormat0
     return true;
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this));
   }
@@ -125,7 +126,7 @@ struct CmapSubtableFormat4
     return true;
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c)
+  inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
     if (unlikely (!c->check_struct (this)))
@@ -183,7 +184,8 @@ struct CmapSubtableLongGroup
     return 0;
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this));
   }
@@ -210,7 +212,8 @@ struct CmapSubtableTrimmed
     return true;
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) && glyphIdArray.sanitize (c));
   }
@@ -242,7 +245,8 @@ struct CmapSubtableLongSegmented
     return true;
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) && groups.sanitize (c));
   }
@@ -288,7 +292,8 @@ struct UnicodeValueRange
     return 0;
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this));
   }
@@ -309,7 +314,8 @@ struct UVSMapping
     return unicodeValue.cmp (codepoint);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this));
   }
@@ -348,7 +354,8 @@ struct VariationSelectorRecord
     return varSelector.cmp (variation_selector);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c, void *base) {
+  inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) &&
 			 defaultUVS.sanitize (c, base) &&
@@ -373,7 +380,8 @@ struct CmapSubtableFormat14
     return record[record.bsearch(variation_selector)].get_glyph (codepoint, glyph, this);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) &&
 			 record.sanitize (c, this));
@@ -418,7 +426,8 @@ struct CmapSubtable
     }
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
     switch (u.format) {
@@ -461,7 +470,8 @@ struct EncodingRecord
     return 0;
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c, void *base) {
+  inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) &&
 			 subtable.sanitize (c, base));
@@ -496,7 +506,8 @@ struct cmap
     return &(this+encodingRecord[result].subtable);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) &&
 			 likely (version == 0) &&
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-ot-head-table.hh b/src/3rdparty/harfbuzz-ng/src/hb-ot-head-table.hh
index ec4e8c9d45..268f133408 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-ot-head-table.hh
+++ b/src/3rdparty/harfbuzz-ng/src/hb-ot-head-table.hh
@@ -45,13 +45,15 @@ struct head
 {
   static const hb_tag_t tableTag	= HB_OT_TAG_head;
 
-  inline unsigned int get_upem (void) const {
+  inline unsigned int get_upem (void) const
+  {
     unsigned int upem = unitsPerEm;
     /* If no valid head table found, assume 1000, which matches typical Type1 usage. */
     return 16 <= upem && upem <= 16384 ? upem : 1000;
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) && likely (version.major == 1));
   }
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-ot-hhea-table.hh b/src/3rdparty/harfbuzz-ng/src/hb-ot-hhea-table.hh
index edc0e29cbf..992fe55202 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-ot-hhea-table.hh
+++ b/src/3rdparty/harfbuzz-ng/src/hb-ot-hhea-table.hh
@@ -49,7 +49,8 @@ struct _hea
   static const hb_tag_t hheaTag	= HB_OT_TAG_hhea;
   static const hb_tag_t vheaTag	= HB_OT_TAG_vhea;
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) && likely (version.major == 1));
   }
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-ot-hmtx-table.hh b/src/3rdparty/harfbuzz-ng/src/hb-ot-hmtx-table.hh
index 317854ce7f..a0e3855a84 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-ot-hmtx-table.hh
+++ b/src/3rdparty/harfbuzz-ng/src/hb-ot-hmtx-table.hh
@@ -57,7 +57,8 @@ struct _mtx
   static const hb_tag_t hmtxTag	= HB_OT_TAG_hmtx;
   static const hb_tag_t vmtxTag	= HB_OT_TAG_vmtx;
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     /* We don't check for anything specific here.  The users of the
      * struct do all the hard work... */
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-common-private.hh b/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-common-private.hh
index abd063c896..3db7f57ab4 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-common-private.hh
+++ b/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-common-private.hh
@@ -37,6 +37,12 @@
 namespace OT {
 
 
+#define TRACE_DISPATCH(this, format) \
+	hb_auto_trace_t<context_t::max_debug_depth, typename context_t::return_t> trace \
+	(&c->debug_depth, c->get_name (), this, HB_FUNC, \
+	 "format %d", (int) format);
+
+
 #define NOT_COVERED		((unsigned int) -1)
 #define MAX_NESTING_LEVEL	8
 #define MAX_CONTEXT_LENGTH	64
@@ -63,9 +69,10 @@ struct Record
 
   struct sanitize_closure_t {
     hb_tag_t tag;
-    void *list_base;
+    const void *list_base;
   };
-  inline bool sanitize (hb_sanitize_context_t *c, void *base) {
+  inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
     TRACE_SANITIZE (this);
     const sanitize_closure_t closure = {tag, base};
     return TRACE_RETURN (c->check_struct (this) && offset.sanitize (c, base, &closure));
@@ -121,7 +128,8 @@ struct RecordListOf : RecordArrayOf<Type>
   inline const Type& operator [] (unsigned int i) const
   { return this+RecordArrayOf<Type>::operator [](i).offset; }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (RecordArrayOf<Type>::sanitize (c, this));
   }
@@ -134,7 +142,8 @@ struct RangeRecord
     return g < start ? -1 : g <= end ? 0 : +1 ;
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this));
   }
@@ -199,7 +208,8 @@ struct LangSys
   }
 
   inline bool sanitize (hb_sanitize_context_t *c,
-			const Record<LangSys>::sanitize_closure_t * = NULL) {
+			const Record<LangSys>::sanitize_closure_t * = NULL) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) && featureIndex.sanitize (c));
   }
@@ -238,7 +248,8 @@ struct Script
   inline const LangSys& get_default_lang_sys (void) const { return this+defaultLangSys; }
 
   inline bool sanitize (hb_sanitize_context_t *c,
-			const Record<Script>::sanitize_closure_t * = NULL) {
+			const Record<Script>::sanitize_closure_t * = NULL) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (defaultLangSys.sanitize (c, this) && langSys.sanitize (c, this));
   }
@@ -260,7 +271,8 @@ typedef RecordListOf<Script> ScriptList;
 /* http://www.microsoft.com/typography/otspec/features_pt.htm#size */
 struct FeatureParamsSize
 {
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     if (unlikely (!c->check_struct (this))) return TRACE_RETURN (false);
 
@@ -371,7 +383,8 @@ struct FeatureParamsSize
 /* http://www.microsoft.com/typography/otspec/features_pt.htm#ssxx */
 struct FeatureParamsStylisticSet
 {
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     /* Right now minorVersion is at zero.  Which means, any table supports
      * the uiNameID field. */
@@ -404,7 +417,8 @@ struct FeatureParamsStylisticSet
 /* http://www.microsoft.com/typography/otspec/features_ae.htm#cv01-cv99 */
 struct FeatureParamsCharacterVariants
 {
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) &&
 			 characters.sanitize (c));
@@ -444,7 +458,8 @@ struct FeatureParamsCharacterVariants
 
 struct FeatureParams
 {
-  inline bool sanitize (hb_sanitize_context_t *c, hb_tag_t tag) {
+  inline bool sanitize (hb_sanitize_context_t *c, hb_tag_t tag) const
+  {
     TRACE_SANITIZE (this);
     if (tag == HB_TAG ('s','i','z','e'))
       return TRACE_RETURN (u.size.sanitize (c));
@@ -486,7 +501,8 @@ struct Feature
   { return this+featureParams; }
 
   inline bool sanitize (hb_sanitize_context_t *c,
-			const Record<Feature>::sanitize_closure_t *closure) {
+			const Record<Feature>::sanitize_closure_t *closure) const
+  {
     TRACE_SANITIZE (this);
     if (unlikely (!(c->check_struct (this) && lookupIndex.sanitize (c))))
       return TRACE_RETURN (false);
@@ -561,6 +577,17 @@ struct Lookup
 {
   inline unsigned int get_subtable_count (void) const { return subTable.len; }
 
+  template <typename SubTableType>
+  inline const SubTableType& get_subtable (unsigned int i) const
+  { return this+CastR<OffsetArrayOf<SubTableType> > (subTable)[i]; }
+
+  template <typename SubTableType>
+  inline const OffsetArrayOf<SubTableType>& get_subtables (void) const
+  { return CastR<OffsetArrayOf<SubTableType> > (subTable); }
+  template <typename SubTableType>
+  inline OffsetArrayOf<SubTableType>& get_subtables (void)
+  { return CastR<OffsetArrayOf<SubTableType> > (subTable); }
+
   inline unsigned int get_type (void) const { return lookupType; }
 
   /* lookup_props is a 32-bit integer where the lower 16-bit is LookupFlag and
@@ -577,6 +604,20 @@ struct Lookup
     return flag;
   }
 
+  template <typename SubTableType, typename context_t>
+  inline typename context_t::return_t dispatch (context_t *c) const
+  {
+    unsigned int lookup_type = get_type ();
+    TRACE_DISPATCH (this, lookup_type);
+    unsigned int count = get_subtable_count ();
+    for (unsigned int i = 0; i < count; i++) {
+      typename context_t::return_t r = get_subtable<SubTableType> (i).dispatch (c, lookup_type);
+      if (c->stop_sublookup_iteration (r))
+        return TRACE_RETURN (r);
+    }
+    return TRACE_RETURN (c->default_return_value ());
+  }
+
   inline bool serialize (hb_serialize_context_t *c,
 			 unsigned int lookup_type,
 			 uint32_t lookup_props,
@@ -595,18 +636,20 @@ struct Lookup
     return TRACE_RETURN (true);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     /* Real sanitize of the subtables is done by GSUB/GPOS/... */
     if (!(c->check_struct (this) && subTable.sanitize (c))) return TRACE_RETURN (false);
     if (lookupFlag & LookupFlag::UseMarkFilteringSet)
     {
-      USHORT &markFilteringSet = StructAfter<USHORT> (subTable);
+      const USHORT &markFilteringSet = StructAfter<USHORT> (subTable);
       if (!markFilteringSet.sanitize (c)) return TRACE_RETURN (false);
     }
     return TRACE_RETURN (true);
   }
 
+  private:
   USHORT	lookupType;		/* Different enumerations for GSUB and GPOS */
   USHORT	lookupFlag;		/* Lookup qualifiers */
   ArrayOf<Offset<> >
@@ -651,7 +694,8 @@ struct CoverageFormat1
     return TRACE_RETURN (true);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (glyphArray.sanitize (c));
   }
@@ -737,7 +781,8 @@ struct CoverageFormat2
     return TRACE_RETURN (true);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (rangeRecord.sanitize (c));
   }
@@ -832,7 +877,8 @@ struct Coverage
     }
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
     switch (u.format) {
@@ -938,12 +984,14 @@ struct ClassDefFormat1
   private:
   inline unsigned int get_class (hb_codepoint_t glyph_id) const
   {
-    if (unlikely ((unsigned int) (glyph_id - startGlyph) < classValue.len))
-      return classValue[glyph_id - startGlyph];
+    unsigned int i = (unsigned int) (glyph_id - startGlyph);
+    if (unlikely (i < classValue.len))
+      return classValue[i];
     return 0;
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) && classValue.sanitize (c));
   }
@@ -994,12 +1042,13 @@ struct ClassDefFormat2
   inline unsigned int get_class (hb_codepoint_t glyph_id) const
   {
     int i = rangeRecord.bsearch (glyph_id);
-    if (i != -1)
+    if (unlikely (i != -1))
       return rangeRecord[i].value;
     return 0;
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (rangeRecord.sanitize (c));
   }
@@ -1056,7 +1105,8 @@ struct ClassDef
     }
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
     switch (u.format) {
@@ -1148,7 +1198,8 @@ struct Device
     return USHORT::static_size * (4 + ((endSize - startSize) >> (4 - f)));
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) && c->check_range (this, this->get_size ()));
   }
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-gdef-table.hh b/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-gdef-table.hh
index 84a5e797c6..7a6c04d170 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-gdef-table.hh
+++ b/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-gdef-table.hh
@@ -71,7 +71,8 @@ struct AttachList
     return points.len;
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (coverage.sanitize (c, this) && attachPoint.sanitize (c, this));
   }
@@ -101,7 +102,8 @@ struct CaretValueFormat1
     return HB_DIRECTION_IS_HORIZONTAL (direction) ? font->em_scale_x (coordinate) : font->em_scale_y (coordinate);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this));
   }
@@ -127,7 +129,8 @@ struct CaretValueFormat2
       return 0;
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this));
   }
@@ -150,7 +153,8 @@ struct CaretValueFormat3
            font->em_scale_y (coordinate) + (this+deviceTable).get_y_delta (font);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) && deviceTable.sanitize (c, this));
   }
@@ -178,7 +182,8 @@ struct CaretValue
     }
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
     switch (u.format) {
@@ -219,7 +224,8 @@ struct LigGlyph
     return carets.len;
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (carets.sanitize (c, this));
   }
@@ -253,7 +259,8 @@ struct LigCaretList
     return lig_glyph.get_lig_carets (font, direction, glyph_id, start_offset, caret_count, caret_array);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (coverage.sanitize (c, this) && ligGlyph.sanitize (c, this));
   }
@@ -275,7 +282,8 @@ struct MarkGlyphSetsFormat1
   inline bool covers (unsigned int set_index, hb_codepoint_t glyph_id) const
   { return (this+coverage[set_index]).get_coverage (glyph_id) != NOT_COVERED; }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (coverage.sanitize (c, this));
   }
@@ -299,7 +307,8 @@ struct MarkGlyphSets
     }
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
     switch (u.format) {
@@ -364,7 +373,8 @@ struct GDEF
   inline bool mark_set_covers (unsigned int set_index, hb_codepoint_t glyph_id) const
   { return version.to_int () >= 0x00010002u && (this+markGlyphSetsDef[0]).covers (set_index, glyph_id); }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (version.sanitize (c) &&
 			 likely (version.major == 1) &&
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-gpos-table.hh b/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-gpos-table.hh
index f7fef5273a..d88f7876e0 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-gpos-table.hh
+++ b/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-gpos-table.hh
@@ -146,7 +146,8 @@ struct ValueFormat : USHORT
   }
 
   private:
-  inline bool sanitize_value_devices (hb_sanitize_context_t *c, void *base, Value *values) {
+  inline bool sanitize_value_devices (hb_sanitize_context_t *c, const void *base, const Value *values) const
+  {
     unsigned int format = *this;
 
     if (format & xPlacement) values++;
@@ -177,12 +178,14 @@ struct ValueFormat : USHORT
     return (format & devices) != 0;
   }
 
-  inline bool sanitize_value (hb_sanitize_context_t *c, void *base, Value *values) {
+  inline bool sanitize_value (hb_sanitize_context_t *c, const void *base, const Value *values) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_range (values, get_size ()) && (!has_device () || sanitize_value_devices (c, base, values)));
   }
 
-  inline bool sanitize_values (hb_sanitize_context_t *c, void *base, Value *values, unsigned int count) {
+  inline bool sanitize_values (hb_sanitize_context_t *c, const void *base, const Value *values, unsigned int count) const
+  {
     TRACE_SANITIZE (this);
     unsigned int len = get_len ();
 
@@ -200,7 +203,8 @@ struct ValueFormat : USHORT
   }
 
   /* Just sanitize referenced Device tables.  Doesn't check the values themselves. */
-  inline bool sanitize_values_stride_unsafe (hb_sanitize_context_t *c, void *base, Value *values, unsigned int count, unsigned int stride) {
+  inline bool sanitize_values_stride_unsafe (hb_sanitize_context_t *c, const void *base, const Value *values, unsigned int count, unsigned int stride) const
+  {
     TRACE_SANITIZE (this);
 
     if (!has_device ()) return TRACE_RETURN (true);
@@ -225,7 +229,8 @@ struct AnchorFormat1
       *y = font->em_scale_y (yCoordinate);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this));
   }
@@ -254,7 +259,8 @@ struct AnchorFormat2
       *y = ret && y_ppem ? cy : font->em_scale_y (yCoordinate);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this));
   }
@@ -282,7 +288,8 @@ struct AnchorFormat3
 	*y += (this+yDeviceTable).get_x_delta (font);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) && xDeviceTable.sanitize (c, this) && yDeviceTable.sanitize (c, this));
   }
@@ -317,7 +324,8 @@ struct Anchor
     }
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
     switch (u.format) {
@@ -349,7 +357,8 @@ struct AnchorMatrix
     return this+matrixZ[row * cols + col];
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c, unsigned int cols) {
+  inline bool sanitize (hb_sanitize_context_t *c, unsigned int cols) const
+  {
     TRACE_SANITIZE (this);
     if (!c->check_struct (this)) return TRACE_RETURN (false);
     if (unlikely (rows > 0 && cols >= ((unsigned int) -1) / rows)) return TRACE_RETURN (false);
@@ -374,7 +383,8 @@ struct MarkRecord
 {
   friend struct MarkArray;
 
-  inline bool sanitize (hb_sanitize_context_t *c, void *base) {
+  inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) && markAnchor.sanitize (c, base));
   }
@@ -421,7 +431,8 @@ struct MarkArray : ArrayOf<MarkRecord>	/* Array of MarkRecords--in Coverage orde
     return TRACE_RETURN (true);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (ArrayOf<MarkRecord>::sanitize (c, this));
   }
@@ -457,9 +468,12 @@ struct SinglePosFormat1
     return TRACE_RETURN (true);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
-    return TRACE_RETURN (c->check_struct (this) && coverage.sanitize (c, this) && valueFormat.sanitize_value (c, this, values));
+    return TRACE_RETURN (c->check_struct (this)
+        && coverage.sanitize (c, this)
+	&& valueFormat.sanitize_value (c, this, values));
   }
 
   protected:
@@ -506,9 +520,12 @@ struct SinglePosFormat2
     return TRACE_RETURN (true);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
-    return TRACE_RETURN (c->check_struct (this) && coverage.sanitize (c, this) && valueFormat.sanitize_values (c, this, values, valueCount));
+    return TRACE_RETURN (c->check_struct (this)
+	&& coverage.sanitize (c, this)
+	&& valueFormat.sanitize_values (c, this, values, valueCount));
   }
 
   protected:
@@ -531,6 +548,7 @@ struct SinglePos
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this, u.format);
+    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
     switch (u.format) {
     case 1: return TRACE_RETURN (c->dispatch (u.format1));
     case 2: return TRACE_RETURN (c->dispatch (u.format2));
@@ -538,16 +556,6 @@ struct SinglePos
     }
   }
 
-  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));
-    default:return TRACE_RETURN (true);
-    }
-  }
-
   protected:
   union {
   USHORT		format;		/* Format identifier */
@@ -636,19 +644,20 @@ struct PairSet
   }
 
   struct sanitize_closure_t {
-    void *base;
-    ValueFormat *valueFormats;
+    const void *base;
+    const ValueFormat *valueFormats;
     unsigned int len1; /* valueFormats[0].get_len() */
     unsigned int stride; /* 1 + len1 + len2 */
   };
 
-  inline bool sanitize (hb_sanitize_context_t *c, const sanitize_closure_t *closure) {
+  inline bool sanitize (hb_sanitize_context_t *c, const sanitize_closure_t *closure) const
+  {
     TRACE_SANITIZE (this);
     if (!(c->check_struct (this)
        && c->check_array (arrayZ, USHORT::static_size * closure->stride, len))) return TRACE_RETURN (false);
 
     unsigned int count = len;
-    PairValueRecord *record = CastP<PairValueRecord> (arrayZ);
+    const PairValueRecord *record = CastP<PairValueRecord> (arrayZ);
     return TRACE_RETURN (closure->valueFormats[0].sanitize_values_stride_unsafe (c, closure->base, &record->values[0], count, closure->stride)
 		      && closure->valueFormats[1].sanitize_values_stride_unsafe (c, closure->base, &record->values[closure->len1], count, closure->stride));
   }
@@ -681,18 +690,18 @@ struct PairPosFormat1
   {
     TRACE_APPLY (this);
     hb_buffer_t *buffer = c->buffer;
-    hb_apply_context_t::skipping_forward_iterator_t skippy_iter (c, buffer->idx, 1);
-    if (skippy_iter.has_no_chance ()) return TRACE_RETURN (false);
-
     unsigned int index = (this+coverage).get_coverage  (buffer->cur().codepoint);
     if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
 
+    hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
+    skippy_iter.reset (buffer->idx, 1);
     if (!skippy_iter.next ()) return TRACE_RETURN (false);
 
     return TRACE_RETURN ((this+pairSet[index]).apply (c, &valueFormat1, skippy_iter.idx));
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
 
     unsigned int len1 = valueFormat1.get_len ();
@@ -752,12 +761,11 @@ struct PairPosFormat2
   {
     TRACE_APPLY (this);
     hb_buffer_t *buffer = c->buffer;
-    hb_apply_context_t::skipping_forward_iterator_t skippy_iter (c, buffer->idx, 1);
-    if (skippy_iter.has_no_chance ()) return TRACE_RETURN (false);
-
     unsigned int index = (this+coverage).get_coverage  (buffer->cur().codepoint);
     if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
 
+    hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
+    skippy_iter.reset (buffer->idx, 1);
     if (!skippy_iter.next ()) return TRACE_RETURN (false);
 
     unsigned int len1 = valueFormat1.get_len ();
@@ -781,7 +789,8 @@ struct PairPosFormat2
     return TRACE_RETURN (true);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     if (!(c->check_struct (this)
        && coverage.sanitize (c, this)
@@ -834,6 +843,7 @@ struct PairPos
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this, u.format);
+    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
     switch (u.format) {
     case 1: return TRACE_RETURN (c->dispatch (u.format1));
     case 2: return TRACE_RETURN (c->dispatch (u.format2));
@@ -841,16 +851,6 @@ struct PairPos
     }
   }
 
-  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));
-    default:return TRACE_RETURN (true);
-    }
-  }
-
   protected:
   union {
   USHORT		format;		/* Format identifier */
@@ -864,7 +864,8 @@ struct EntryExitRecord
 {
   friend struct CursivePosFormat1;
 
-  inline bool sanitize (hb_sanitize_context_t *c, void *base) {
+  inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (entryAnchor.sanitize (c, base) && exitAnchor.sanitize (c, base));
   }
@@ -903,12 +904,11 @@ struct CursivePosFormat1
     /* We don't handle mark glyphs here. */
     if (unlikely (_hb_glyph_info_is_mark (&buffer->cur()))) return TRACE_RETURN (false);
 
-    hb_apply_context_t::skipping_forward_iterator_t skippy_iter (c, buffer->idx, 1);
-    if (skippy_iter.has_no_chance ()) return TRACE_RETURN (false);
-
     const EntryExitRecord &this_record = entryExitRecord[(this+coverage).get_coverage  (buffer->cur().codepoint)];
     if (!this_record.exitAnchor) return TRACE_RETURN (false);
 
+    hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
+    skippy_iter.reset (buffer->idx, 1);
     if (!skippy_iter.next ()) return TRACE_RETURN (false);
 
     const EntryExitRecord &next_record = entryExitRecord[(this+coverage).get_coverage  (buffer->info[skippy_iter.idx].codepoint)];
@@ -978,7 +978,8 @@ struct CursivePosFormat1
     return TRACE_RETURN (true);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (coverage.sanitize (c, this) && entryExitRecord.sanitize (c, this));
   }
@@ -1001,21 +1002,13 @@ struct CursivePos
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this, u.format);
+    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
     switch (u.format) {
     case 1: return TRACE_RETURN (c->dispatch (u.format1));
     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));
-    default:return TRACE_RETURN (true);
-    }
-  }
-
   protected:
   union {
   USHORT		format;		/* Format identifier */
@@ -1051,7 +1044,8 @@ struct MarkBasePosFormat1
     if (likely (mark_index == NOT_COVERED)) return TRACE_RETURN (false);
 
     /* now we search backwards for a non-mark glyph */
-    hb_apply_context_t::skipping_backward_iterator_t skippy_iter (c, buffer->idx, 1);
+    hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
+    skippy_iter.reset (buffer->idx, 1);
     skippy_iter.set_lookup_props (LookupFlag::IgnoreMarks);
     do {
       if (!skippy_iter.prev ()) return TRACE_RETURN (false);
@@ -1069,7 +1063,8 @@ struct MarkBasePosFormat1
     return TRACE_RETURN ((this+markArray).apply (c, mark_index, base_index, this+baseArray, classCount, skippy_iter.idx));
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) && markCoverage.sanitize (c, this) && baseCoverage.sanitize (c, this) &&
 			 markArray.sanitize (c, this) && baseArray.sanitize (c, this, (unsigned int) classCount));
@@ -1100,21 +1095,13 @@ struct MarkBasePos
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this, u.format);
+    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
     switch (u.format) {
     case 1: return TRACE_RETURN (c->dispatch (u.format1));
     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));
-    default:return TRACE_RETURN (true);
-    }
-  }
-
   protected:
   union {
   USHORT		format;		/* Format identifier */
@@ -1155,7 +1142,8 @@ struct MarkLigPosFormat1
     if (likely (mark_index == NOT_COVERED)) return TRACE_RETURN (false);
 
     /* now we search backwards for a non-mark glyph */
-    hb_apply_context_t::skipping_backward_iterator_t skippy_iter (c, buffer->idx, 1);
+    hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
+    skippy_iter.reset (buffer->idx, 1);
     skippy_iter.set_lookup_props (LookupFlag::IgnoreMarks);
     if (!skippy_iter.prev ()) return TRACE_RETURN (false);
 
@@ -1189,7 +1177,8 @@ struct MarkLigPosFormat1
     return TRACE_RETURN ((this+markArray).apply (c, mark_index, comp_index, lig_attach, classCount, j));
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) && markCoverage.sanitize (c, this) && ligatureCoverage.sanitize (c, this) &&
 			 markArray.sanitize (c, this) && ligatureArray.sanitize (c, this, (unsigned int) classCount));
@@ -1221,21 +1210,13 @@ struct MarkLigPos
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this, u.format);
+    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
     switch (u.format) {
     case 1: return TRACE_RETURN (c->dispatch (u.format1));
     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));
-    default:return TRACE_RETURN (true);
-    }
-  }
-
   protected:
   union {
   USHORT		format;		/* Format identifier */
@@ -1271,7 +1252,8 @@ struct MarkMarkPosFormat1
     if (likely (mark1_index == NOT_COVERED)) return TRACE_RETURN (false);
 
     /* now we search backwards for a suitable mark glyph until a non-mark glyph */
-    hb_apply_context_t::skipping_backward_iterator_t skippy_iter (c, buffer->idx, 1);
+    hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
+    skippy_iter.reset (buffer->idx, 1);
     skippy_iter.set_lookup_props (c->lookup_props & ~LookupFlag::IgnoreFlags);
     if (!skippy_iter.prev ()) return TRACE_RETURN (false);
 
@@ -1306,7 +1288,8 @@ struct MarkMarkPosFormat1
     return TRACE_RETURN ((this+mark1Array).apply (c, mark1_index, mark2_index, this+mark2Array, classCount, j));
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) && mark1Coverage.sanitize (c, this) &&
 			 mark2Coverage.sanitize (c, this) && mark1Array.sanitize (c, this)
@@ -1340,21 +1323,13 @@ struct MarkMarkPos
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this, u.format);
+    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
     switch (u.format) {
     case 1: return TRACE_RETURN (c->dispatch (u.format1));
     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));
-    default:return TRACE_RETURN (true);
-    }
-  }
-
   protected:
   union {
   USHORT		format;		/* Format identifier */
@@ -1399,6 +1374,8 @@ struct PosLookupSubTable
   inline typename context_t::return_t dispatch (context_t *c, unsigned int lookup_type) const
   {
     TRACE_DISPATCH (this, lookup_type);
+    /* The sub_format passed to may_dispatch is unnecessary but harmless. */
+    if (unlikely (!c->may_dispatch (this, &u.sub_format))) TRACE_RETURN (c->default_return_value ());
     switch (lookup_type) {
     case Single:		return TRACE_RETURN (u.single.dispatch (c));
     case Pair:			return TRACE_RETURN (u.pair.dispatch (c));
@@ -1413,29 +1390,9 @@ struct PosLookupSubTable
     }
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c, unsigned int lookup_type) {
-    TRACE_SANITIZE (this);
-    if (!u.header.sub_format.sanitize (c))
-      return TRACE_RETURN (false);
-    switch (lookup_type) {
-    case Single:		return TRACE_RETURN (u.single.sanitize (c));
-    case Pair:			return TRACE_RETURN (u.pair.sanitize (c));
-    case Cursive:		return TRACE_RETURN (u.cursive.sanitize (c));
-    case MarkBase:		return TRACE_RETURN (u.markBase.sanitize (c));
-    case MarkLig:		return TRACE_RETURN (u.markLig.sanitize (c));
-    case MarkMark:		return TRACE_RETURN (u.markMark.sanitize (c));
-    case Context:		return TRACE_RETURN (u.context.sanitize (c));
-    case ChainContext:		return TRACE_RETURN (u.chainContext.sanitize (c));
-    case Extension:		return TRACE_RETURN (u.extension.sanitize (c));
-    default:			return TRACE_RETURN (true);
-    }
-  }
-
   protected:
   union {
-  struct {
-    USHORT		sub_format;
-  } header;
+  USHORT		sub_format;
   SinglePos		single;
   PairPos		pair;
   CursivePos		cursive;
@@ -1447,48 +1404,37 @@ struct PosLookupSubTable
   ExtensionPos		extension;
   } u;
   public:
-  DEFINE_SIZE_UNION (2, header.sub_format);
+  DEFINE_SIZE_UNION (2, sub_format);
 };
 
 
 struct PosLookup : Lookup
 {
   inline const PosLookupSubTable& get_subtable (unsigned int i) const
-  { return this+CastR<OffsetArrayOf<PosLookupSubTable> > (subTable)[i]; }
+  { return Lookup::get_subtable<PosLookupSubTable> (i); }
 
   inline bool is_reverse (void) const
   {
     return false;
   }
 
+  inline bool apply (hb_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+    return TRACE_RETURN (dispatch (c));
+  }
+
   inline hb_collect_glyphs_context_t::return_t collect_glyphs (hb_collect_glyphs_context_t *c) const
   {
     TRACE_COLLECT_GLYPHS (this);
-    c->set_recurse_func (NULL);
     return TRACE_RETURN (dispatch (c));
   }
 
   template <typename set_t>
   inline void add_coverage (set_t *glyphs) const
   {
-    hb_get_coverage_context_t c;
-    const Coverage *last = NULL;
-    unsigned int count = get_subtable_count ();
-    for (unsigned int i = 0; i < count; i++) {
-      const Coverage *coverage = &get_subtable (i).dispatch (&c, get_type ());
-      if (coverage != last) {
-        coverage->add_coverage (glyphs);
-        last = coverage;
-      }
-    }
-  }
-
-  inline bool apply_once (hb_apply_context_t *c) const
-  {
-    TRACE_APPLY (this);
-    if (!c->check_glyph_property (&c->buffer->cur(), c->lookup_props))
-      return TRACE_RETURN (false);
-    return TRACE_RETURN (dispatch (c));
+    hb_add_coverage_context_t<set_t> c (glyphs);
+    dispatch (&c);
   }
 
   static bool apply_recurse_func (hb_apply_context_t *c, unsigned int lookup_index);
@@ -1498,23 +1444,14 @@ struct PosLookup : Lookup
 
   template <typename context_t>
   inline typename context_t::return_t dispatch (context_t *c) const
-  {
-    unsigned int lookup_type = get_type ();
-    TRACE_DISPATCH (this, lookup_type);
-    unsigned int count = get_subtable_count ();
-    for (unsigned int i = 0; i < count; i++) {
-      typename context_t::return_t r = get_subtable (i).dispatch (c, lookup_type);
-      if (c->stop_sublookup_iteration (r))
-        return TRACE_RETURN (r);
-    }
-    return TRACE_RETURN (c->default_return_value ());
-  }
+  { return Lookup::dispatch<PosLookupSubTable> (c); }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     if (unlikely (!Lookup::sanitize (c))) return TRACE_RETURN (false);
-    OffsetArrayOf<PosLookupSubTable> &list = CastR<OffsetArrayOf<PosLookupSubTable> > (subTable);
-    return TRACE_RETURN (list.sanitize (c, this, get_type ()));
+    const OffsetArrayOf<PosLookupSubTable> &list = get_subtables<PosLookupSubTable> ();
+    return TRACE_RETURN (dispatch (c));
   }
 };
 
@@ -1534,10 +1471,11 @@ struct GPOS : GSUBGPOS
   static inline void position_start (hb_font_t *font, hb_buffer_t *buffer);
   static inline void position_finish (hb_font_t *font, hb_buffer_t *buffer);
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     if (unlikely (!GSUBGPOS::sanitize (c))) return TRACE_RETURN (false);
-    OffsetTo<PosLookupList> &list = CastR<OffsetTo<PosLookupList> > (lookupList);
+    const OffsetTo<PosLookupList> &list = CastR<OffsetTo<PosLookupList> > (lookupList);
     return TRACE_RETURN (list.sanitize (c, this));
   }
   public:
@@ -1632,8 +1570,8 @@ template <typename context_t>
   const PosLookup &l = gpos.get_lookup (lookup_index);
   unsigned int saved_lookup_props = c->lookup_props;
   c->set_lookup (l);
-  bool ret = l.apply_once (c);
-  c->lookup_props = saved_lookup_props;
+  bool ret = l.dispatch (c);
+  c->set_lookup_props (saved_lookup_props);
   return ret;
 }
 
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-gsub-table.hh b/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-gsub-table.hh
index 5d67be0ec0..ebe4c9ec4e 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-gsub-table.hh
+++ b/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-gsub-table.hh
@@ -97,7 +97,8 @@ struct SingleSubstFormat1
     return TRACE_RETURN (true);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (coverage.sanitize (c, this) && deltaGlyphID.sanitize (c));
   }
@@ -173,7 +174,8 @@ struct SingleSubstFormat2
     return TRACE_RETURN (true);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (coverage.sanitize (c, this) && substitute.sanitize (c));
   }
@@ -223,6 +225,7 @@ struct SingleSubst
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this, u.format);
+    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
     switch (u.format) {
     case 1: return TRACE_RETURN (c->dispatch (u.format1));
     case 2: return TRACE_RETURN (c->dispatch (u.format2));
@@ -230,16 +233,6 @@ struct SingleSubst
     }
   }
 
-  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));
-    default:return TRACE_RETURN (true);
-    }
-  }
-
   protected:
   union {
   USHORT		format;		/* Format identifier */
@@ -312,7 +305,8 @@ struct Sequence
     return TRACE_RETURN (true);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (substitute.sanitize (c));
   }
@@ -384,7 +378,8 @@ struct MultipleSubstFormat1
     return TRACE_RETURN (true);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (coverage.sanitize (c, this) && sequence.sanitize (c, this));
   }
@@ -423,21 +418,13 @@ struct MultipleSubst
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this, u.format);
+    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
     switch (u.format) {
     case 1: return TRACE_RETURN (c->dispatch (u.format1));
     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));
-    default:return TRACE_RETURN (true);
-    }
-  }
-
   protected:
   union {
   USHORT		format;		/* Format identifier */
@@ -535,7 +522,8 @@ struct AlternateSubstFormat1
     return TRACE_RETURN (true);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (coverage.sanitize (c, this) && alternateSet.sanitize (c, this));
   }
@@ -574,21 +562,13 @@ struct AlternateSubst
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this, u.format);
+    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
     switch (u.format) {
     case 1: return TRACE_RETURN (c->dispatch (u.format1));
     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));
-    default:return TRACE_RETURN (true);
-    }
-  }
-
   protected:
   union {
   USHORT		format;		/* Format identifier */
@@ -686,7 +666,8 @@ struct Ligature
   }
 
   public:
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (ligGlyph.sanitize (c) && component.sanitize (c));
   }
@@ -764,7 +745,8 @@ struct LigatureSet
     return TRACE_RETURN (true);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (ligature.sanitize (c, this));
   }
@@ -848,7 +830,8 @@ struct LigatureSubstFormat1
     return TRACE_RETURN (true);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (coverage.sanitize (c, this) && ligatureSet.sanitize (c, this));
   }
@@ -890,21 +873,13 @@ struct LigatureSubst
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this, u.format);
+    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
     switch (u.format) {
     case 1: return TRACE_RETURN (c->dispatch (u.format1));
     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));
-    default:return TRACE_RETURN (true);
-    }
-  }
-
   protected:
   union {
   USHORT		format;		/* Format identifier */
@@ -1017,14 +992,15 @@ struct ReverseChainSingleSubstFormat1
     return TRACE_RETURN (false);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     if (!(coverage.sanitize (c, this) && backtrack.sanitize (c, this)))
       return TRACE_RETURN (false);
-    OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
+    const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
     if (!lookahead.sanitize (c, this))
       return TRACE_RETURN (false);
-    ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
+    const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
     return TRACE_RETURN (substitute.sanitize (c));
   }
 
@@ -1054,21 +1030,13 @@ struct ReverseChainSingleSubst
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this, u.format);
+    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
     switch (u.format) {
     case 1: return TRACE_RETURN (c->dispatch (u.format1));
     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));
-    default:return TRACE_RETURN (true);
-    }
-  }
-
   protected:
   union {
   USHORT				format;		/* Format identifier */
@@ -1101,6 +1069,8 @@ struct SubstLookupSubTable
   inline typename context_t::return_t dispatch (context_t *c, unsigned int lookup_type) const
   {
     TRACE_DISPATCH (this, lookup_type);
+    /* The sub_format passed to may_dispatch is unnecessary but harmless. */
+    if (unlikely (!c->may_dispatch (this, &u.sub_format))) TRACE_RETURN (c->default_return_value ());
     switch (lookup_type) {
     case Single:		return TRACE_RETURN (u.single.dispatch (c));
     case Multiple:		return TRACE_RETURN (u.multiple.dispatch (c));
@@ -1114,28 +1084,9 @@ struct SubstLookupSubTable
     }
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c, unsigned int lookup_type) {
-    TRACE_SANITIZE (this);
-    if (!u.header.sub_format.sanitize (c))
-      return TRACE_RETURN (false);
-    switch (lookup_type) {
-    case Single:		return TRACE_RETURN (u.single.sanitize (c));
-    case Multiple:		return TRACE_RETURN (u.multiple.sanitize (c));
-    case Alternate:		return TRACE_RETURN (u.alternate.sanitize (c));
-    case Ligature:		return TRACE_RETURN (u.ligature.sanitize (c));
-    case Context:		return TRACE_RETURN (u.context.sanitize (c));
-    case ChainContext:		return TRACE_RETURN (u.chainContext.sanitize (c));
-    case Extension:		return TRACE_RETURN (u.extension.sanitize (c));
-    case ReverseChainSingle:	return TRACE_RETURN (u.reverseChainContextSingle.sanitize (c));
-    default:			return TRACE_RETURN (true);
-    }
-  }
-
   protected:
   union {
-  struct {
-    USHORT			sub_format;
-  } header;
+  USHORT			sub_format;
   SingleSubst			single;
   MultipleSubst			multiple;
   AlternateSubst		alternate;
@@ -1146,14 +1097,14 @@ struct SubstLookupSubTable
   ReverseChainSingleSubst	reverseChainContextSingle;
   } u;
   public:
-  DEFINE_SIZE_UNION (2, header.sub_format);
+  DEFINE_SIZE_UNION (2, sub_format);
 };
 
 
 struct SubstLookup : Lookup
 {
   inline const SubstLookupSubTable& get_subtable (unsigned int i) const
-  { return this+CastR<OffsetArrayOf<SubstLookupSubTable> > (subTable)[i]; }
+  { return Lookup::get_subtable<SubstLookupSubTable> (i); }
 
   inline static bool lookup_type_is_reverse (unsigned int lookup_type)
   { return lookup_type == SubstLookupSubTable::ReverseChainSingle; }
@@ -1166,6 +1117,12 @@ struct SubstLookup : Lookup
     return lookup_type_is_reverse (type);
   }
 
+  inline bool apply (hb_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+    return TRACE_RETURN (dispatch (c));
+  }
+
   inline hb_closure_context_t::return_t closure (hb_closure_context_t *c) const
   {
     TRACE_CLOSURE (this);
@@ -1183,39 +1140,24 @@ struct SubstLookup : Lookup
   template <typename set_t>
   inline void add_coverage (set_t *glyphs) const
   {
-    hb_get_coverage_context_t c;
-    const Coverage *last = NULL;
-    unsigned int count = get_subtable_count ();
-    for (unsigned int i = 0; i < count; i++) {
-      const Coverage *coverage = &get_subtable (i).dispatch (&c, get_type ());
-      if (coverage != last) {
-        coverage->add_coverage (glyphs);
-        last = coverage;
-      }
-    }
+    hb_add_coverage_context_t<set_t> c (glyphs);
+    dispatch (&c);
   }
 
-  inline bool would_apply (hb_would_apply_context_t *c, const hb_set_digest_t *digest) const
+  inline bool would_apply (hb_would_apply_context_t *c,
+			   const hb_ot_layout_lookup_accelerator_t *accel) const
   {
     TRACE_WOULD_APPLY (this);
     if (unlikely (!c->len))  return TRACE_RETURN (false);
-    if (!digest->may_have (c->glyphs[0]))  return TRACE_RETURN (false);
+    if (!accel->may_have (c->glyphs[0]))  return TRACE_RETURN (false);
       return TRACE_RETURN (dispatch (c));
   }
 
-  inline bool apply_once (hb_apply_context_t *c) const
-  {
-    TRACE_APPLY (this);
-    if (!c->check_glyph_property (&c->buffer->cur(), c->lookup_props))
-      return TRACE_RETURN (false);
-    return TRACE_RETURN (dispatch (c));
-  }
-
   static bool apply_recurse_func (hb_apply_context_t *c, unsigned int lookup_index);
 
   inline SubstLookupSubTable& serialize_subtable (hb_serialize_context_t *c,
 						  unsigned int i)
-  { return CastR<OffsetArrayOf<SubstLookupSubTable> > (subTable)[i].serialize (c, this); }
+  { return get_subtables<SubstLookupSubTable> ()[i].serialize (c, this); }
 
   inline bool serialize_single (hb_serialize_context_t *c,
 				uint32_t lookup_props,
@@ -1274,24 +1216,14 @@ struct SubstLookup : Lookup
 
   template <typename context_t>
   inline typename context_t::return_t dispatch (context_t *c) const
-  {
-    unsigned int lookup_type = get_type ();
-    TRACE_DISPATCH (this, lookup_type);
-    unsigned int count = get_subtable_count ();
-    for (unsigned int i = 0; i < count; i++) {
-      typename context_t::return_t r = get_subtable (i).dispatch (c, lookup_type);
-      if (c->stop_sublookup_iteration (r))
-        return TRACE_RETURN (r);
-    }
-    return TRACE_RETURN (c->default_return_value ());
-  }
+  { return Lookup::dispatch<SubstLookupSubTable> (c); }
 
-  inline bool sanitize (hb_sanitize_context_t *c)
+  inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
     if (unlikely (!Lookup::sanitize (c))) return TRACE_RETURN (false);
-    OffsetArrayOf<SubstLookupSubTable> &list = CastR<OffsetArrayOf<SubstLookupSubTable> > (subTable);
-    if (unlikely (!list.sanitize (c, this, get_type ()))) return TRACE_RETURN (false);
+    const OffsetArrayOf<SubstLookupSubTable> &list = get_subtables<SubstLookupSubTable> ();
+    if (unlikely (!dispatch (c))) return TRACE_RETURN (false);
 
     if (unlikely (get_type () == SubstLookupSubTable::Extension))
     {
@@ -1324,10 +1256,11 @@ struct GSUB : GSUBGPOS
   static inline void substitute_start (hb_font_t *font, hb_buffer_t *buffer);
   static inline void substitute_finish (hb_font_t *font, hb_buffer_t *buffer);
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     if (unlikely (!GSUBGPOS::sanitize (c))) return TRACE_RETURN (false);
-    OffsetTo<SubstLookupList> &list = CastR<OffsetTo<SubstLookupList> > (lookupList);
+    const OffsetTo<SubstLookupList> &list = CastR<OffsetTo<SubstLookupList> > (lookupList);
     return TRACE_RETURN (list.sanitize (c, this));
   }
   public:
@@ -1362,7 +1295,7 @@ GSUB::substitute_finish (hb_font_t *font HB_UNUSED, hb_buffer_t *buffer HB_UNUSE
 {
   unsigned int type = get_type ();
   if (unlikely (type == SubstLookupSubTable::Extension))
-    return CastR<ExtensionSubst> (get_subtable<SubstLookupSubTable>()).is_reverse ();
+    return CastR<ExtensionSubst> (get_subtable<LookupSubTable>()).is_reverse ();
   return SubstLookup::lookup_type_is_reverse (type);
 }
 
@@ -1380,8 +1313,8 @@ template <typename context_t>
   const SubstLookup &l = gsub.get_lookup (lookup_index);
   unsigned int saved_lookup_props = c->lookup_props;
   c->set_lookup (l);
-  bool ret = l.apply_once (c);
-  c->lookup_props = saved_lookup_props;
+  bool ret = l.dispatch (c);
+  c->set_lookup_props (saved_lookup_props);
   return ret;
 }
 
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-gsubgpos-private.hh b/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-gsubgpos-private.hh
index 57fc1e05f7..cbc6840bc8 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-gsubgpos-private.hh
+++ b/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-gsubgpos-private.hh
@@ -37,12 +37,6 @@
 namespace OT {
 
 
-
-#define TRACE_DISPATCH(this, format) \
-	hb_auto_trace_t<context_t::max_debug_depth, typename context_t::return_t> trace \
-	(&c->debug_depth, c->get_name (), this, HB_FUNC, \
-	 "format %d", (int) format);
-
 #ifndef HB_DEBUG_CLOSURE
 #define HB_DEBUG_CLOSURE (HB_DEBUG+0)
 #endif
@@ -58,6 +52,8 @@ struct hb_closure_context_t
   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, typename F>
+  inline bool may_dispatch (const T *obj, const F *format) { return true; }
   template <typename T>
   inline return_t dispatch (const T &obj) { obj.closure (this); return HB_VOID; }
   static return_t default_return_value (void) { return HB_VOID; }
@@ -107,6 +103,8 @@ 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, typename F>
+  inline bool may_dispatch (const T *obj, const F *format) { return true; }
   template <typename T>
   inline return_t dispatch (const T &obj) { return obj.would_apply (this); }
   static return_t default_return_value (void) { return false; }
@@ -146,6 +144,8 @@ struct hb_collect_glyphs_context_t
   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, typename F>
+  inline bool may_dispatch (const T *obj, const F *format) { return true; }
   template <typename T>
   inline return_t dispatch (const T &obj) { obj.collect_glyphs (this); return HB_VOID; }
   static return_t default_return_value (void) { return HB_VOID; }
@@ -232,18 +232,28 @@ struct hb_collect_glyphs_context_t
 #define HB_DEBUG_GET_COVERAGE (HB_DEBUG+0)
 #endif
 
-struct hb_get_coverage_context_t
+template <typename set_t>
+struct hb_add_coverage_context_t
 {
   inline const char *get_name (void) { return "GET_COVERAGE"; }
   static const unsigned int max_debug_depth = HB_DEBUG_GET_COVERAGE;
   typedef const Coverage &return_t;
+  template <typename T, typename F>
+  inline bool may_dispatch (const T *obj, const F *format) { return true; }
   template <typename T>
   inline return_t dispatch (const T &obj) { return obj.get_coverage (); }
   static return_t default_return_value (void) { return Null(Coverage); }
+  bool stop_sublookup_iteration (return_t r) const
+  {
+    r.add_coverage (set);
+    return false;
+  }
 
-  hb_get_coverage_context_t (void) :
+  hb_add_coverage_context_t (set_t *set_) :
+			    set (set_),
 			    debug_depth (0) {}
 
+  set_t *set;
   unsigned int debug_depth;
 };
 
@@ -260,61 +270,6 @@ struct hb_get_coverage_context_t
 
 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 dispatch (const T &obj) { return obj.apply (this); }
-  static return_t default_return_value (void) { return false; }
-  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;
-  const GDEF &gdef;
-  bool has_glyph_classes;
-  unsigned int debug_depth;
-
-
-  hb_apply_context_t (unsigned int table_index_,
-		      hb_font_t *font_,
-		      hb_buffer_t *buffer_) :
-			table_index (table_index_),
-			font (font_), face (font->face), buffer (buffer_),
-			direction (buffer_->props.direction),
-			lookup_mask (1),
-			auto_zwj (true),
-			recurse_func (NULL),
-			nesting_level_left (MAX_NESTING_LEVEL),
-			lookup_props (0),
-			gdef (*hb_ot_layout_from_face (face)->gdef),
-			has_glyph_classes (gdef.has_glyph_classes ()),
-			debug_depth (0) {}
-
-  inline void set_lookup_mask (hb_mask_t mask) { lookup_mask = mask; }
-  inline void set_auto_zwj (bool auto_zwj_) { auto_zwj = auto_zwj_; }
-  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 matcher_t (void) :
@@ -390,29 +345,24 @@ struct hb_apply_context_t
     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)
+  struct skipping_iterator_t
+  {
+    inline void init (hb_apply_context_t *c_, bool context_match = false)
     {
+      c = c_;
+      match_glyph_data = NULL,
+      matcher.set_match_func (NULL, NULL);
       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);
+      matcher.set_mask (context_match ? -1 : c->lookup_mask);
+    }
+    inline void set_lookup_props (unsigned int lookup_props)
+    {
+      matcher.set_lookup_props (lookup_props);
     }
-    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[])
@@ -421,12 +371,21 @@ struct hb_apply_context_t
       match_glyph_data = glyph_data;
     }
 
-    inline bool has_no_chance (void) const { return unlikely (num_items && idx + num_items >= end); }
+    inline void reset (unsigned int start_index_,
+		       unsigned int num_items_)
+    {
+      idx = start_index_;
+      num_items = num_items_;
+      end = c->buffer->len;
+      matcher.set_syllable (start_index_ == c->buffer->idx ? c->buffer->cur().syllable () : 0);
+    }
+
     inline void reject (void) { num_items++; match_glyph_data--; }
+
     inline bool next (void)
     {
       assert (num_items > 0);
-      while (!has_no_chance ())
+      while (idx + num_items < end)
       {
 	idx++;
 	const hb_glyph_info_t &info = c->buffer->info[idx];
@@ -450,53 +409,10 @@ struct hb_apply_context_t
       }
       return false;
     }
-
-    unsigned int idx;
-    protected:
-    hb_apply_context_t *c;
-    matcher_t matcher;
-    const USHORT *match_glyph_data;
-
-    unsigned int num_items;
-    unsigned int end;
-  };
-
-  struct skipping_backward_iterator_t
-  {
-    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);
-      while (!has_no_chance ())
+      while (idx >= num_items)
       {
 	idx--;
 	const hb_glyph_info_t &info = c->buffer->out_info[idx];
@@ -528,8 +444,75 @@ struct hb_apply_context_t
     const USHORT *match_glyph_data;
 
     unsigned int num_items;
+    unsigned int end;
   };
 
+
+  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, typename F>
+  inline bool may_dispatch (const T *obj, const F *format) { return true; }
+  template <typename T>
+  inline return_t dispatch (const T &obj) { return obj.apply (this); }
+  static return_t default_return_value (void) { return false; }
+  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;
+  const GDEF &gdef;
+  bool has_glyph_classes;
+  skipping_iterator_t iter_input, iter_context;
+  unsigned int debug_depth;
+
+
+  hb_apply_context_t (unsigned int table_index_,
+		      hb_font_t *font_,
+		      hb_buffer_t *buffer_) :
+			table_index (table_index_),
+			font (font_), face (font->face), buffer (buffer_),
+			direction (buffer_->props.direction),
+			lookup_mask (1),
+			auto_zwj (true),
+			recurse_func (NULL),
+			nesting_level_left (MAX_NESTING_LEVEL),
+			lookup_props (0),
+			gdef (*hb_ot_layout_from_face (face)->gdef),
+			has_glyph_classes (gdef.has_glyph_classes ()),
+			iter_input (),
+			iter_context (),
+			debug_depth (0) {}
+
+  inline void set_lookup_mask (hb_mask_t mask) { lookup_mask = mask; }
+  inline void set_auto_zwj (bool auto_zwj_) { auto_zwj = auto_zwj_; }
+  inline void set_recurse_func (recurse_func_t func) { recurse_func = func; }
+  inline void set_lookup (const Lookup &l) { set_lookup_props (l.get_props ()); }
+  inline void set_lookup_props (unsigned int lookup_props_)
+  {
+    lookup_props = lookup_props_;
+    iter_input.init (this, false);
+    iter_context.init (this, true);
+  }
+
   inline bool
   match_properties_mark (hb_codepoint_t  glyph,
 			 unsigned int    glyph_props,
@@ -741,9 +724,9 @@ static inline bool match_input (hb_apply_context_t *c,
 
   hb_buffer_t *buffer = c->buffer;
 
-  hb_apply_context_t::skipping_forward_iterator_t skippy_iter (c, buffer->idx, count - 1);
+  hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
+  skippy_iter.reset (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:
@@ -910,9 +893,9 @@ static inline bool match_backtrack (hb_apply_context_t *c,
 {
   TRACE_APPLY (NULL);
 
-  hb_apply_context_t::skipping_backward_iterator_t skippy_iter (c, c->buffer->backtrack_len (), count, true);
+  hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_context;
+  skippy_iter.reset (c->buffer->backtrack_len (), count);
   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 ())
@@ -930,9 +913,9 @@ static inline bool match_lookahead (hb_apply_context_t *c,
 {
   TRACE_APPLY (NULL);
 
-  hb_apply_context_t::skipping_forward_iterator_t skippy_iter (c, c->buffer->idx + offset - 1, count, true);
+  hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_context;
+  skippy_iter.reset (c->buffer->idx + offset - 1, count);
   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 ())
@@ -945,7 +928,8 @@ static inline bool match_lookahead (hb_apply_context_t *c,
 
 struct LookupRecord
 {
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this));
   }
@@ -1168,7 +1152,8 @@ struct Rule
   }
 
   public:
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return inputCount.sanitize (c)
 	&& lookupCount.sanitize (c)
@@ -1232,7 +1217,8 @@ struct RuleSet
     return TRACE_RETURN (false);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (rule.sanitize (c, this));
   }
@@ -1314,7 +1300,8 @@ struct ContextFormat1
     return TRACE_RETURN (rule_set.apply (c, lookup_context));
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (coverage.sanitize (c, this) && ruleSet.sanitize (c, this));
   }
@@ -1406,7 +1393,8 @@ struct ContextFormat2
     return TRACE_RETURN (rule_set.apply (c, lookup_context));
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (coverage.sanitize (c, this) && classDef.sanitize (c, this) && ruleSet.sanitize (c, this));
   }
@@ -1494,7 +1482,8 @@ struct ContextFormat3
     return TRACE_RETURN (context_apply_lookup (c, glyphCount, (const USHORT *) (coverageZ + 1), lookupCount, lookupRecord, lookup_context));
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     if (!c->check_struct (this)) return TRACE_RETURN (false);
     unsigned int count = glyphCount;
@@ -1502,7 +1491,7 @@ struct ContextFormat3
     if (!c->check_array (coverageZ, coverageZ[0].static_size, count)) return TRACE_RETURN (false);
     for (unsigned int i = 0; i < count; i++)
       if (!coverageZ[i].sanitize (c, this)) return TRACE_RETURN (false);
-    LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * count);
+    const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * count);
     return TRACE_RETURN (c->check_array (lookupRecord, lookupRecord[0].static_size, lookupCount));
   }
 
@@ -1526,6 +1515,7 @@ struct Context
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this, u.format);
+    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
     switch (u.format) {
     case 1: return TRACE_RETURN (c->dispatch (u.format1));
     case 2: return TRACE_RETURN (c->dispatch (u.format2));
@@ -1534,17 +1524,6 @@ struct Context
     }
   }
 
-  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));
-    case 3: return TRACE_RETURN (u.format3.sanitize (c));
-    default:return TRACE_RETURN (true);
-    }
-  }
-
   protected:
   union {
   USHORT		format;		/* Format identifier */
@@ -1726,14 +1705,15 @@ struct ChainRule
 						     lookup.array, lookup_context));
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     if (!backtrack.sanitize (c)) return TRACE_RETURN (false);
-    HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
+    const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
     if (!input.sanitize (c)) return TRACE_RETURN (false);
-    ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
+    const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
     if (!lookahead.sanitize (c)) return TRACE_RETURN (false);
-    ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
+    const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
     return TRACE_RETURN (lookup.sanitize (c));
   }
 
@@ -1795,7 +1775,8 @@ struct ChainRuleSet
     return TRACE_RETURN (false);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (rule.sanitize (c, this));
   }
@@ -1874,7 +1855,8 @@ struct ChainContextFormat1
     return TRACE_RETURN (rule_set.apply (c, lookup_context));
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (coverage.sanitize (c, this) && ruleSet.sanitize (c, this));
   }
@@ -1984,7 +1966,8 @@ struct ChainContextFormat2
     return TRACE_RETURN (rule_set.apply (c, lookup_context));
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (coverage.sanitize (c, this) && backtrackClassDef.sanitize (c, this) &&
 			 inputClassDef.sanitize (c, this) && lookaheadClassDef.sanitize (c, this) &&
@@ -2105,15 +2088,16 @@ struct ChainContextFormat3
 						     lookup.len, lookup.array, lookup_context));
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     if (!backtrack.sanitize (c, this)) return TRACE_RETURN (false);
-    OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
+    const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
     if (!input.sanitize (c, this)) return TRACE_RETURN (false);
     if (!input.len) return TRACE_RETURN (false); /* To be consistent with Context. */
-    OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
+    const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
     if (!lookahead.sanitize (c, this)) return TRACE_RETURN (false);
-    ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
+    const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
     return TRACE_RETURN (lookup.sanitize (c));
   }
 
@@ -2144,6 +2128,7 @@ struct ChainContext
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this, u.format);
+    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
     switch (u.format) {
     case 1: return TRACE_RETURN (c->dispatch (u.format1));
     case 2: return TRACE_RETURN (c->dispatch (u.format2));
@@ -2152,17 +2137,6 @@ struct ChainContext
     }
   }
 
-  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));
-    case 3: return TRACE_RETURN (u.format3.sanitize (c));
-    default:return TRACE_RETURN (true);
-    }
-  }
-
   protected:
   union {
   USHORT		format;	/* Format identifier */
@@ -2173,14 +2147,32 @@ struct ChainContext
 };
 
 
+template <typename T>
 struct ExtensionFormat1
 {
   inline unsigned int get_type (void) const { return extensionLookupType; }
-  inline unsigned int get_offset (void) const { return extensionOffset; }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  template <typename X>
+  inline const X& get_subtable (void) const
+  {
+    unsigned int offset = extensionOffset;
+    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 dispatch (context_t *c) const
+  {
+    TRACE_DISPATCH (this, format);
+    if (unlikely (!c->may_dispatch (this, this))) TRACE_RETURN (c->default_return_value ());
+    return get_subtable<typename T::LookupSubTable> ().dispatch (c, get_type ());
+  }
+
+  /* This is called from may_dispatch() above with hb_sanitize_context_t. */
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
-    return TRACE_RETURN (c->check_struct (this));
+    return TRACE_RETURN (c->check_struct (this) && extensionOffset != 0);
   }
 
   protected:
@@ -2204,49 +2196,30 @@ struct Extension
     default:return 0;
     }
   }
-  inline unsigned int get_offset (void) const
-  {
-    switch (u.format) {
-    case 1: return u.format1.get_offset ();
-    default:return 0;
-    }
-  }
-
   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);
+    switch (u.format) {
+    case 1: return u.format1.template get_subtable<typename T::LookupSubTable> ();
+    default:return Null(typename T::LookupSubTable);
+    }
   }
 
   template <typename context_t>
   inline typename context_t::return_t dispatch (context_t *c) const
   {
-    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);
+    TRACE_DISPATCH (this, u.format);
+    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
     switch (u.format) {
-    case 1: return TRACE_RETURN (u.format1.sanitize (c));
-    default:return TRACE_RETURN (true);
+    case 1: return TRACE_RETURN (u.format1.dispatch (c));
+    default:return TRACE_RETURN (c->default_return_value ());
     }
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
-    TRACE_SANITIZE (this);
-    if (!sanitize_self (c)) return TRACE_RETURN (false);
-    unsigned int offset = get_offset ();
-    if (unlikely (!offset)) return TRACE_RETURN (true);
-    return TRACE_RETURN (StructAtOffset<typename T::LookupSubTable> (this, offset).sanitize (c, get_type ()));
-  }
-
   protected:
   union {
   USHORT		format;		/* Format identifier */
-  ExtensionFormat1	format1;
+  ExtensionFormat1<T>	format1;
   } u;
 };
 
@@ -2291,7 +2264,8 @@ struct GSUBGPOS
   inline const Lookup& get_lookup (unsigned int i) const
   { return (this+lookupList)[i]; }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (version.sanitize (c) && likely (version.major == 1) &&
 			 scriptList.sanitize (c, this) &&
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-jstf-table.hh b/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-jstf-table.hh
index 67a6df5b42..739dfd9106 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-jstf-table.hh
+++ b/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-jstf-table.hh
@@ -54,7 +54,8 @@ typedef OffsetListOf<PosLookup> JstfMax;
 
 struct JstfPriority
 {
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) &&
 			 shrinkageEnableGSUB.sanitize (c, this) &&
@@ -123,7 +124,8 @@ struct JstfPriority
 struct JstfLangSys : OffsetListOf<JstfPriority>
 {
   inline bool sanitize (hb_sanitize_context_t *c,
-			const Record<JstfLangSys>::sanitize_closure_t * = NULL) {
+			const Record<JstfLangSys>::sanitize_closure_t * = NULL) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (OffsetListOf<JstfPriority>::sanitize (c));
   }
@@ -163,7 +165,8 @@ struct JstfScript
   inline const JstfLangSys& get_default_lang_sys (void) const { return this+defaultLangSys; }
 
   inline bool sanitize (hb_sanitize_context_t *c,
-			const Record<JstfScript>::sanitize_closure_t * = NULL) {
+			const Record<JstfScript>::sanitize_closure_t * = NULL) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (extenderGlyphs.sanitize (c, this) &&
 			 defaultLangSys.sanitize (c, this) &&
@@ -206,7 +209,8 @@ struct JSTF
   inline bool find_script_index (hb_tag_t tag, unsigned int *index) const
   { return scriptList.find_index (tag, index); }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (version.sanitize (c) && likely (version.major == 1) &&
 			 scriptList.sanitize (c, this));
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-private.hh b/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-private.hh
index 3f7c858d1c..47fecd216d 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-private.hh
+++ b/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-private.hh
@@ -130,6 +130,11 @@ struct hb_ot_layout_lookup_accelerator_t
   {
   }
 
+  inline bool may_have (hb_codepoint_t g) const {
+    return digest.may_have (g);
+  }
+
+  private:
   hb_set_digest_t digest;
 };
 
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-ot-layout.cc b/src/3rdparty/harfbuzz-ng/src/hb-ot-layout.cc
index 602b94ecd6..b1e69e89f4 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-ot-layout.cc
+++ b/src/3rdparty/harfbuzz-ng/src/hb-ot-layout.cc
@@ -699,7 +699,7 @@ hb_ot_layout_lookup_would_substitute_fast (hb_face_t            *face,
 
   const OT::SubstLookup& l = hb_ot_layout_from_face (face)->gsub->get_lookup (lookup_index);
 
-  return l.would_apply (&c, &hb_ot_layout_from_face (face)->gsub_accels[lookup_index].digest);
+  return l.would_apply (&c, &hb_ot_layout_from_face (face)->gsub_accels[lookup_index]);
 }
 
 void
@@ -829,26 +829,83 @@ struct GPOSProxy
 };
 
 
-template <typename Lookup>
-static inline bool apply_once (OT::hb_apply_context_t *c,
-			       const Lookup &lookup)
+template <typename Obj>
+static inline bool
+apply_forward (OT::hb_apply_context_t *c,
+	       const Obj &obj,
+	       const hb_ot_layout_lookup_accelerator_t &accel)
 {
-  if (!c->check_glyph_property (&c->buffer->cur(), c->lookup_props))
-    return false;
-  return lookup.dispatch (c);
+  bool ret = false;
+  hb_buffer_t *buffer = c->buffer;
+  while (buffer->idx < buffer->len)
+  {
+    if (accel.may_have (buffer->cur().codepoint) &&
+	(buffer->cur().mask & c->lookup_mask) &&
+	c->check_glyph_property (&buffer->cur(), c->lookup_props) &&
+	obj.apply (c))
+      ret = true;
+    else
+      buffer->next_glyph ();
+  }
+  return ret;
 }
 
-template <typename Proxy>
+template <typename Obj>
 static inline bool
+apply_backward (OT::hb_apply_context_t *c,
+		const Obj &obj,
+		const hb_ot_layout_lookup_accelerator_t &accel)
+{
+  bool ret = false;
+  hb_buffer_t *buffer = c->buffer;
+  do
+  {
+    if (accel.may_have (buffer->cur().codepoint) &&
+	(buffer->cur().mask & c->lookup_mask) &&
+	c->check_glyph_property (&buffer->cur(), c->lookup_props) &&
+	obj.apply (c))
+      ret = true;
+    /* The reverse lookup doesn't "advance" cursor (for good reason). */
+    buffer->idx--;
+
+  }
+  while ((int) buffer->idx >= 0);
+  return ret;
+}
+
+struct hb_apply_forward_context_t
+{
+  inline const char *get_name (void) { return "APPLY_FORWARD"; }
+  static const unsigned int max_debug_depth = HB_DEBUG_APPLY;
+  typedef bool return_t;
+  template <typename T, typename F>
+  inline bool may_dispatch (const T *obj, const F *format) { return true; }
+  template <typename T>
+  inline return_t dispatch (const T &obj) { return apply_forward (c, obj, accel); }
+  static return_t default_return_value (void) { return false; }
+  bool stop_sublookup_iteration (return_t r HB_UNUSED) const { return true; }
+
+  hb_apply_forward_context_t (OT::hb_apply_context_t *c_,
+			      const hb_ot_layout_lookup_accelerator_t &accel_) :
+				c (c_),
+				accel (accel_),
+				debug_depth (0) {}
+
+  OT::hb_apply_context_t *c;
+  const hb_ot_layout_lookup_accelerator_t &accel;
+  unsigned int debug_depth;
+};
+
+template <typename Proxy>
+static inline void
 apply_string (OT::hb_apply_context_t *c,
 	      const typename Proxy::Lookup &lookup,
 	      const hb_ot_layout_lookup_accelerator_t &accel)
 {
-  bool ret = false;
   hb_buffer_t *buffer = c->buffer;
 
   if (unlikely (!buffer->len || !c->lookup_mask))
-    return false;
+    return;
 
   c->set_lookup (lookup);
 
@@ -859,21 +916,20 @@ apply_string (OT::hb_apply_context_t *c,
       buffer->clear_output ();
     buffer->idx = 0;
 
-    while (buffer->idx < buffer->len)
+    bool ret;
+    if (lookup.get_subtable_count () == 1)
     {
-      if (accel.digest.may_have (buffer->cur().codepoint) &&
-	  (buffer->cur().mask & c->lookup_mask) &&
-	  apply_once (c, lookup))
-	ret = true;
-      else
-	buffer->next_glyph ();
+      hb_apply_forward_context_t c_forward (c, accel);
+      ret = lookup.dispatch (&c_forward);
     }
+    else
+      ret = apply_forward (c, lookup, accel);
     if (ret)
     {
       if (!Proxy::inplace)
 	buffer->swap_buffers ();
       else
-        assert (!buffer->has_separate_output ());
+	assert (!buffer->has_separate_output ());
     }
   }
   else
@@ -882,20 +938,9 @@ apply_string (OT::hb_apply_context_t *c,
     if (Proxy::table_index == 0)
       buffer->remove_output ();
     buffer->idx = buffer->len - 1;
-    do
-    {
-      if (accel.digest.may_have (buffer->cur().codepoint) &&
-	  (buffer->cur().mask & c->lookup_mask) &&
-	  apply_once (c, lookup))
-	ret = true;
-      /* The reverse lookup doesn't "advance" cursor (for good reason). */
-      buffer->idx--;
 
-    }
-    while ((int) buffer->idx >= 0);
+    apply_backward (c, lookup, accel);
   }
-
-  return ret;
 }
 
 template <typename Proxy>
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-ot-maxp-table.hh b/src/3rdparty/harfbuzz-ng/src/hb-ot-maxp-table.hh
index b1f832852d..0d9a0fa1d8 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-ot-maxp-table.hh
+++ b/src/3rdparty/harfbuzz-ng/src/hb-ot-maxp-table.hh
@@ -43,11 +43,13 @@ struct maxp
 {
   static const hb_tag_t tableTag	= HB_OT_TAG_maxp;
 
-  inline unsigned int get_num_glyphs (void) const {
+  inline unsigned int get_num_glyphs (void) const
+  {
     return numGlyphs;
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) &&
 			 likely (version.major == 1 || (version.major == 0 && version.minor == 0x5000u)));
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-ot-name-table.hh b/src/3rdparty/harfbuzz-ng/src/hb-ot-name-table.hh
index 31d9fac7e2..21450c6138 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-ot-name-table.hh
+++ b/src/3rdparty/harfbuzz-ng/src/hb-ot-name-table.hh
@@ -56,7 +56,8 @@ struct NameRecord
     return 0;
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c, void *base) {
+  inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
     TRACE_SANITIZE (this);
     /* We can check from base all the way up to the end of string... */
     return TRACE_RETURN (c->check_struct (this) && c->check_range ((char *) base, (unsigned int) length + offset));
@@ -101,7 +102,7 @@ struct name
   inline unsigned int get_size (void) const
   { return min_size + count * nameRecord[0].min_size; }
 
-  inline bool sanitize_records (hb_sanitize_context_t *c) {
+  inline bool sanitize_records (hb_sanitize_context_t *c) const {
     TRACE_SANITIZE (this);
     char *string_pool = (char *) this + stringOffset;
     unsigned int _count = count;
@@ -110,7 +111,8 @@ struct name
     return TRACE_RETURN (true);
   }
 
-  inline bool sanitize (hb_sanitize_context_t *c) {
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this) &&
 			 likely (format == 0 || format == 1) &&
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-ot-shape-fallback.cc b/src/3rdparty/harfbuzz-ng/src/hb-ot-shape-fallback.cc
index 80d7da82f3..53274b502a 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-ot-shape-fallback.cc
+++ b/src/3rdparty/harfbuzz-ng/src/hb-ot-shape-fallback.cc
@@ -441,13 +441,15 @@ _hb_ot_shape_fallback_kern (const hb_ot_shape_plan_t *plan,
   OT::hb_apply_context_t c (1, font, buffer);
   c.set_lookup_mask (plan->kern_mask);
   c.set_lookup_props (OT::LookupFlag::IgnoreMarks);
+  OT::hb_apply_context_t::skipping_iterator_t &skippy_iter = c.iter_input;
+  skippy_iter.init (&c);
 
   unsigned int count = buffer->len;
   hb_glyph_info_t *info = buffer->info;
   hb_glyph_position_t *pos = buffer->pos;
   for (unsigned int idx = 0; idx < count;)
   {
-    OT::hb_apply_context_t::skipping_forward_iterator_t skippy_iter (&c, idx, 1);
+    skippy_iter.reset (idx, 1);
     if (!skippy_iter.next ())
     {
       idx++;
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-private.hh b/src/3rdparty/harfbuzz-ng/src/hb-private.hh
index cfe77f1606..06b24a80f8 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-private.hh
+++ b/src/3rdparty/harfbuzz-ng/src/hb-private.hh
@@ -573,6 +573,30 @@ _hb_debug (unsigned int level,
 #define DEBUG_LEVEL_ENABLED(WHAT, LEVEL) (_hb_debug ((LEVEL), HB_DEBUG_##WHAT))
 #define DEBUG_ENABLED(WHAT) (DEBUG_LEVEL_ENABLED (WHAT, 0))
 
+static inline void
+_hb_print_func (const char *func)
+{
+  if (func)
+  {
+    unsigned int func_len = strlen (func);
+    /* Skip "static" */
+    if (0 == strncmp (func, "static ", 7))
+      func += 7;
+    /* Skip "typename" */
+    if (0 == strncmp (func, "typename ", 9))
+      func += 9;
+    /* Skip return type */
+    const char *space = strchr (func, ' ');
+    if (space)
+      func = space + 1;
+    /* Skip parameter list */
+    const char *paren = strchr (func, '(');
+    if (paren)
+      func_len = paren - func;
+    fprintf (stderr, "%.*s", func_len, func);
+  }
+}
+
 template <int max_level> static inline void
 _hb_debug_msg_va (const char *what,
 		  const void *obj,
@@ -618,27 +642,13 @@ _hb_debug_msg_va (const char *what,
   } else
     fprintf (stderr, "   " VRBAR LBAR);
 
-  if (func)
-  {
-    unsigned int func_len = strlen (func);
-#ifndef HB_DEBUG_VERBOSE
-    /* Skip "typename" */
-    if (0 == strncmp (func, "typename ", 9))
-      func += 9;
-    /* Skip return type */
-    const char *space = strchr (func, ' ');
-    if (space)
-      func = space + 1;
-    /* Skip parameter list */
-    const char *paren = strchr (func, '(');
-    if (paren)
-      func_len = paren - func;
-#endif
-    fprintf (stderr, "%.*s: ", func_len, func);
-  }
+  _hb_print_func (func);
 
   if (message)
+  {
+    fprintf (stderr, ": ");
     vfprintf (stderr, message, ap);
+  }
 
   fprintf (stderr, "\n");
 }
@@ -810,7 +820,7 @@ hb_in_range (T u, T lo, T hi)
   /* The sizeof() is here to force template instantiation.
    * I'm sure there are better ways to do this but can't think of
    * one right now.  Declaring a variable won't work as HB_UNUSED
-   * is unsable on some platforms and unused types are less likely
+   * is unusable on some platforms and unused types are less likely
    * to generate a warning than unused variables. */
   ASSERT_STATIC (sizeof (hb_assert_unsigned_t<T>) >= 0);
 
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-set-private.hh b/src/3rdparty/harfbuzz-ng/src/hb-set-private.hh
index 59e8f4559f..acba4e946b 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-set-private.hh
+++ b/src/3rdparty/harfbuzz-ng/src/hb-set-private.hh
@@ -145,6 +145,8 @@ typedef hb_set_digest_combiner_t
 
 struct hb_set_t
 {
+  friend struct hb_frozen_set_t;
+
   hb_object_header_t header;
   ASSERT_POD ();
   bool in_error;
@@ -326,7 +328,7 @@ struct hb_set_t
   static  const hb_codepoint_t INVALID = HB_SET_VALUE_INVALID;
 
   elt_t &elt (hb_codepoint_t g) { return elts[g >> SHIFT]; }
-  elt_t elt (hb_codepoint_t g) const { return elts[g >> SHIFT]; }
+  elt_t const &elt (hb_codepoint_t g) const { return elts[g >> SHIFT]; }
   elt_t mask (hb_codepoint_t g) const { return elt_t (1) << (g & MASK); }
 
   elt_t elts[ELTS]; /* XXX 8kb */
@@ -335,6 +337,59 @@ struct hb_set_t
   ASSERT_STATIC (sizeof (elt_t) * 8 * ELTS > MAX_G);
 };
 
+struct hb_frozen_set_t
+{
+  static const unsigned int SHIFT = hb_set_t::SHIFT;
+  static const unsigned int BITS = hb_set_t::BITS;
+  static const unsigned int MASK = hb_set_t::MASK;
+  typedef hb_set_t::elt_t elt_t;
+
+  inline void init (const hb_set_t &set)
+  {
+    start = count = 0;
+    elts = NULL;
+
+    unsigned int max = set.get_max ();
+    if (max == set.INVALID)
+      return;
+    unsigned int min = set.get_min ();
+    const elt_t &min_elt = set.elt (min);
+    const elt_t &max_elt = set.elt (max);
+
+    start = min & ~MASK;
+    count = max - start + 1;
+    unsigned int num_elts = (count + BITS - 1) / BITS;
+    unsigned int elts_size = num_elts * sizeof (elt_t);
+    elts = (elt_t *) malloc (elts_size);
+    if (unlikely (!elts))
+    {
+      start = count = 0;
+      return;
+    }
+    memcpy (elts, &min_elt, elts_size);
+  }
+
+  inline void fini (void)
+  {
+    if (elts)
+      free (elts);
+  }
+
+  inline bool has (hb_codepoint_t g) const
+  {
+    /* hb_codepoint_t is unsigned. */
+    g -= start;
+    if (unlikely (g > count)) return false;
+    return !!(elt (g) & mask (g));
+  }
+
+  elt_t const &elt (hb_codepoint_t g) const { return elts[g >> SHIFT]; }
+  elt_t mask (hb_codepoint_t g) const { return elt_t (1) << (g & MASK); }
+
+  private:
+  hb_codepoint_t start, count;
+  elt_t *elts;
+};
 
 
 #endif /* HB_SET_PRIVATE_HH */
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-version.h b/src/3rdparty/harfbuzz-ng/src/hb-version.h
index b9f8a057c9..eacdc598d9 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-version.h
+++ b/src/3rdparty/harfbuzz-ng/src/hb-version.h
@@ -38,9 +38,9 @@ HB_BEGIN_DECLS
 
 #define HB_VERSION_MAJOR 0
 #define HB_VERSION_MINOR 9
-#define HB_VERSION_MICRO 38
+#define HB_VERSION_MICRO 39
 
-#define HB_VERSION_STRING "0.9.38"
+#define HB_VERSION_STRING "0.9.39"
 
 #define HB_VERSION_ATLEAST(major,minor,micro) \
 	((major)*10000+(minor)*100+(micro) <= \
author	Konstantin Ritt <ritt.ks@gmail.com>	2015-03-06 20:09:52 +0400
committer	Konstantin Ritt <ritt.ks@gmail.com>	2015-03-11 21:47:19 +0000
commit	b50e52ed162edbd857b8bb6f4d7d7639f6df119c (patch)
tree	1fe2cc5bbf3a53eb99b3d6834fef12fdb9a1e40c
parent	6ca406d43d63d4c6503f2213b6c8cf0f25f6af5e (diff)