Add m-esr52 at 52.6.0

1 files changed, 1369 insertions, 0 deletions

diff --git a/gfx/harfbuzz/src/hb-ot-layout-gsub-table.hh b/gfx/harfbuzz/src/hb-ot-layout-gsub-table.hh
new file mode 100644
index 000000000..66fcb3f3a
--- /dev/null
+++ b/gfx/harfbuzz/src/hb-ot-layout-gsub-table.hh
@@ -0,0 +1,1369 @@
+/*
+ * Copyright © 2007,2008,2009,2010  Red Hat, Inc.
+ * Copyright © 2010,2012,2013  Google, Inc.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Red Hat Author(s): Behdad Esfahbod
+ * Google Author(s): Behdad Esfahbod
+ */
+
+#ifndef HB_OT_LAYOUT_GSUB_TABLE_HH
+#define HB_OT_LAYOUT_GSUB_TABLE_HH
+
+#include "hb-ot-layout-gsubgpos-private.hh"
+
+
+namespace OT {
+
+
+struct SingleSubstFormat1
+{
+  inline void closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE (this);
+    Coverage::Iter iter;
+    for (iter.init (this+coverage); iter.more (); iter.next ())
+    {
+      /* TODO Switch to range-based API to work around malicious fonts.
+       * https://github.com/behdad/harfbuzz/issues/363 */
+      hb_codepoint_t glyph_id = iter.get_glyph ();
+      if (c->glyphs->has (glyph_id))
+	c->glyphs->add ((glyph_id + deltaGlyphID) & 0xFFFFu);
+    }
+  }
+
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    TRACE_COLLECT_GLYPHS (this);
+    Coverage::Iter iter;
+    for (iter.init (this+coverage); iter.more (); iter.next ())
+    {
+      /* TODO Switch to range-based API to work around malicious fonts.
+       * https://github.com/behdad/harfbuzz/issues/363 */
+      hb_codepoint_t glyph_id = iter.get_glyph ();
+      c->input->add (glyph_id);
+      c->output->add ((glyph_id + deltaGlyphID) & 0xFFFFu);
+    }
+  }
+
+  inline const Coverage &get_coverage (void) const
+  {
+    return this+coverage;
+  }
+
+  inline bool would_apply (hb_would_apply_context_t *c) const
+  {
+    TRACE_WOULD_APPLY (this);
+    return_trace (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
+  }
+
+  inline bool apply (hb_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+    hb_codepoint_t glyph_id = c->buffer->cur().codepoint;
+    unsigned int index = (this+coverage).get_coverage (glyph_id);
+    if (likely (index == NOT_COVERED)) return_trace (false);
+
+    /* According to the Adobe Annotated OpenType Suite, result is always
+     * limited to 16bit. */
+    glyph_id = (glyph_id + deltaGlyphID) & 0xFFFFu;
+    c->replace_glyph (glyph_id);
+
+    return_trace (true);
+  }
+
+  inline bool serialize (hb_serialize_context_t *c,
+			 Supplier<GlyphID> &glyphs,
+			 unsigned int num_glyphs,
+			 int delta)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (*this))) return_trace (false);
+    if (unlikely (!coverage.serialize (c, this).serialize (c, glyphs, num_glyphs))) return_trace (false);
+    deltaGlyphID.set (delta); /* TODO(serilaize) overflow? */
+    return_trace (true);
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (coverage.sanitize (c, this) && deltaGlyphID.sanitize (c));
+  }
+
+  protected:
+  USHORT	format;			/* Format identifier--format = 1 */
+  OffsetTo<Coverage>
+		coverage;		/* Offset to Coverage table--from
+					 * beginning of Substitution table */
+  SHORT		deltaGlyphID;		/* Add to original GlyphID to get
+					 * substitute GlyphID */
+  public:
+  DEFINE_SIZE_STATIC (6);
+};
+
+struct SingleSubstFormat2
+{
+  inline void closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE (this);
+    Coverage::Iter iter;
+    unsigned int count = substitute.len;
+    for (iter.init (this+coverage); iter.more (); iter.next ())
+    {
+      if (unlikely (iter.get_coverage () >= count))
+        break; /* Work around malicious fonts. https://github.com/behdad/harfbuzz/issues/363 */
+      if (c->glyphs->has (iter.get_glyph ()))
+	c->glyphs->add (substitute[iter.get_coverage ()]);
+    }
+  }
+
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    TRACE_COLLECT_GLYPHS (this);
+    Coverage::Iter iter;
+    unsigned int count = substitute.len;
+    for (iter.init (this+coverage); iter.more (); iter.next ())
+    {
+      if (unlikely (iter.get_coverage () >= count))
+        break; /* Work around malicious fonts. https://github.com/behdad/harfbuzz/issues/363 */
+      c->input->add (iter.get_glyph ());
+      c->output->add (substitute[iter.get_coverage ()]);
+    }
+  }
+
+  inline const Coverage &get_coverage (void) const
+  {
+    return this+coverage;
+  }
+
+  inline bool would_apply (hb_would_apply_context_t *c) const
+  {
+    TRACE_WOULD_APPLY (this);
+    return_trace (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
+  }
+
+  inline bool apply (hb_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+    hb_codepoint_t glyph_id = c->buffer->cur().codepoint;
+    unsigned int index = (this+coverage).get_coverage (glyph_id);
+    if (likely (index == NOT_COVERED)) return_trace (false);
+
+    if (unlikely (index >= substitute.len)) return_trace (false);
+
+    glyph_id = substitute[index];
+    c->replace_glyph (glyph_id);
+
+    return_trace (true);
+  }
+
+  inline bool serialize (hb_serialize_context_t *c,
+			 Supplier<GlyphID> &glyphs,
+			 Supplier<GlyphID> &substitutes,
+			 unsigned int num_glyphs)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (*this))) return_trace (false);
+    if (unlikely (!substitute.serialize (c, substitutes, num_glyphs))) return_trace (false);
+    if (unlikely (!coverage.serialize (c, this).serialize (c, glyphs, num_glyphs))) return_trace (false);
+    return_trace (true);
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (coverage.sanitize (c, this) && substitute.sanitize (c));
+  }
+
+  protected:
+  USHORT	format;			/* Format identifier--format = 2 */
+  OffsetTo<Coverage>
+		coverage;		/* Offset to Coverage table--from
+					 * beginning of Substitution table */
+  ArrayOf<GlyphID>
+		substitute;		/* Array of substitute
+					 * GlyphIDs--ordered by Coverage Index */
+  public:
+  DEFINE_SIZE_ARRAY (6, substitute);
+};
+
+struct SingleSubst
+{
+  inline bool serialize (hb_serialize_context_t *c,
+			 Supplier<GlyphID> &glyphs,
+			 Supplier<GlyphID> &substitutes,
+			 unsigned int num_glyphs)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (u.format))) return_trace (false);
+    unsigned int format = 2;
+    int delta = 0;
+    if (num_glyphs) {
+      format = 1;
+      /* TODO(serialize) check for wrap-around */
+      delta = substitutes[0] - glyphs[0];
+      for (unsigned int i = 1; i < num_glyphs; i++)
+	if (delta != substitutes[i] - glyphs[i]) {
+	  format = 2;
+	  break;
+	}
+    }
+    u.format.set (format);
+    switch (u.format) {
+    case 1: return_trace (u.format1.serialize (c, glyphs, num_glyphs, delta));
+    case 2: return_trace (u.format2.serialize (c, glyphs, substitutes, num_glyphs));
+    default:return_trace (false);
+    }
+  }
+
+  template <typename context_t>
+  inline typename context_t::return_t dispatch (context_t *c) const
+  {
+    TRACE_DISPATCH (this, u.format);
+    if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
+    switch (u.format) {
+    case 1: return_trace (c->dispatch (u.format1));
+    case 2: return_trace (c->dispatch (u.format2));
+    default:return_trace (c->default_return_value ());
+    }
+  }
+
+  protected:
+  union {
+  USHORT		format;		/* Format identifier */
+  SingleSubstFormat1	format1;
+  SingleSubstFormat2	format2;
+  } u;
+};
+
+
+struct Sequence
+{
+  inline void closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE (this);
+    unsigned int count = substitute.len;
+    for (unsigned int i = 0; i < count; i++)
+      c->glyphs->add (substitute[i]);
+  }
+
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    TRACE_COLLECT_GLYPHS (this);
+    unsigned int count = substitute.len;
+    for (unsigned int i = 0; i < count; i++)
+      c->output->add (substitute[i]);
+  }
+
+  inline bool apply (hb_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+    unsigned int count = substitute.len;
+
+    /* Special-case to make it in-place and not consider this
+     * as a "multiplied" substitution. */
+    if (unlikely (count == 1))
+    {
+      c->replace_glyph (substitute.array[0]);
+      return_trace (true);
+    }
+    /* Spec disallows this, but Uniscribe allows it.
+     * https://github.com/behdad/harfbuzz/issues/253 */
+    else if (unlikely (count == 0))
+    {
+      c->buffer->delete_glyph ();
+      return_trace (true);
+    }
+
+    unsigned int klass = _hb_glyph_info_is_ligature (&c->buffer->cur()) ?
+			 HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH : 0;
+
+    for (unsigned int i = 0; i < count; i++) {
+      _hb_glyph_info_set_lig_props_for_component (&c->buffer->cur(), i);
+      c->output_glyph_for_component (substitute.array[i], klass);
+    }
+    c->buffer->skip_glyph ();
+
+    return_trace (true);
+  }
+
+  inline bool serialize (hb_serialize_context_t *c,
+			 Supplier<GlyphID> &glyphs,
+			 unsigned int num_glyphs)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (*this))) return_trace (false);
+    if (unlikely (!substitute.serialize (c, glyphs, num_glyphs))) return_trace (false);
+    return_trace (true);
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (substitute.sanitize (c));
+  }
+
+  protected:
+  ArrayOf<GlyphID>
+		substitute;		/* String of GlyphIDs to substitute */
+  public:
+  DEFINE_SIZE_ARRAY (2, substitute);
+};
+
+struct MultipleSubstFormat1
+{
+  inline void closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE (this);
+    Coverage::Iter iter;
+    unsigned int count = sequence.len;
+    for (iter.init (this+coverage); iter.more (); iter.next ())
+    {
+      if (unlikely (iter.get_coverage () >= count))
+        break; /* Work around malicious fonts. https://github.com/behdad/harfbuzz/issues/363 */
+      if (c->glyphs->has (iter.get_glyph ()))
+	(this+sequence[iter.get_coverage ()]).closure (c);
+    }
+  }
+
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    TRACE_COLLECT_GLYPHS (this);
+    (this+coverage).add_coverage (c->input);
+    unsigned int count = sequence.len;
+    for (unsigned int i = 0; i < count; i++)
+	(this+sequence[i]).collect_glyphs (c);
+  }
+
+  inline const Coverage &get_coverage (void) const
+  {
+    return this+coverage;
+  }
+
+  inline bool would_apply (hb_would_apply_context_t *c) const
+  {
+    TRACE_WOULD_APPLY (this);
+    return_trace (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
+  }
+
+  inline bool apply (hb_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+
+    unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
+    if (likely (index == NOT_COVERED)) return_trace (false);
+
+    return_trace ((this+sequence[index]).apply (c));
+  }
+
+  inline bool serialize (hb_serialize_context_t *c,
+			 Supplier<GlyphID> &glyphs,
+			 Supplier<unsigned int> &substitute_len_list,
+			 unsigned int num_glyphs,
+			 Supplier<GlyphID> &substitute_glyphs_list)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (*this))) return_trace (false);
+    if (unlikely (!sequence.serialize (c, num_glyphs))) return_trace (false);
+    for (unsigned int i = 0; i < num_glyphs; i++)
+      if (unlikely (!sequence[i].serialize (c, this).serialize (c,
+								substitute_glyphs_list,
+								substitute_len_list[i]))) return_trace (false);
+    substitute_len_list.advance (num_glyphs);
+    if (unlikely (!coverage.serialize (c, this).serialize (c, glyphs, num_glyphs))) return_trace (false);
+    return_trace (true);
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (coverage.sanitize (c, this) && sequence.sanitize (c, this));
+  }
+
+  protected:
+  USHORT	format;			/* Format identifier--format = 1 */
+  OffsetTo<Coverage>
+		coverage;		/* Offset to Coverage table--from
+					 * beginning of Substitution table */
+  OffsetArrayOf<Sequence>
+		sequence;		/* Array of Sequence tables
+					 * ordered by Coverage Index */
+  public:
+  DEFINE_SIZE_ARRAY (6, sequence);
+};
+
+struct MultipleSubst
+{
+  inline bool serialize (hb_serialize_context_t *c,
+			 Supplier<GlyphID> &glyphs,
+			 Supplier<unsigned int> &substitute_len_list,
+			 unsigned int num_glyphs,
+			 Supplier<GlyphID> &substitute_glyphs_list)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (u.format))) return_trace (false);
+    unsigned int format = 1;
+    u.format.set (format);
+    switch (u.format) {
+    case 1: return_trace (u.format1.serialize (c, glyphs, substitute_len_list, num_glyphs, substitute_glyphs_list));
+    default:return_trace (false);
+    }
+  }
+
+  template <typename context_t>
+  inline typename context_t::return_t dispatch (context_t *c) const
+  {
+    TRACE_DISPATCH (this, u.format);
+    if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
+    switch (u.format) {
+    case 1: return_trace (c->dispatch (u.format1));
+    default:return_trace (c->default_return_value ());
+    }
+  }
+
+  protected:
+  union {
+  USHORT		format;		/* Format identifier */
+  MultipleSubstFormat1	format1;
+  } u;
+};
+
+
+typedef ArrayOf<GlyphID> AlternateSet;	/* Array of alternate GlyphIDs--in
+					 * arbitrary order */
+
+struct AlternateSubstFormat1
+{
+  inline void closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE (this);
+    Coverage::Iter iter;
+    unsigned int count = alternateSet.len;
+    for (iter.init (this+coverage); iter.more (); iter.next ())
+    {
+      if (unlikely (iter.get_coverage () >= count))
+        break; /* Work around malicious fonts. https://github.com/behdad/harfbuzz/issues/363 */
+      if (c->glyphs->has (iter.get_glyph ())) {
+	const AlternateSet &alt_set = this+alternateSet[iter.get_coverage ()];
+	unsigned int count = alt_set.len;
+	for (unsigned int i = 0; i < count; i++)
+	  c->glyphs->add (alt_set[i]);
+      }
+    }
+  }
+
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    TRACE_COLLECT_GLYPHS (this);
+    Coverage::Iter iter;
+    unsigned int count = alternateSet.len;
+    for (iter.init (this+coverage); iter.more (); iter.next ())
+    {
+      if (unlikely (iter.get_coverage () >= count))
+        break; /* Work around malicious fonts. https://github.com/behdad/harfbuzz/issues/363 */
+      c->input->add (iter.get_glyph ());
+      const AlternateSet &alt_set = this+alternateSet[iter.get_coverage ()];
+      unsigned int count = alt_set.len;
+      for (unsigned int i = 0; i < count; i++)
+	c->output->add (alt_set[i]);
+    }
+  }
+
+  inline const Coverage &get_coverage (void) const
+  {
+    return this+coverage;
+  }
+
+  inline bool would_apply (hb_would_apply_context_t *c) const
+  {
+    TRACE_WOULD_APPLY (this);
+    return_trace (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
+  }
+
+  inline bool apply (hb_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+    hb_codepoint_t glyph_id = c->buffer->cur().codepoint;
+
+    unsigned int index = (this+coverage).get_coverage (glyph_id);
+    if (likely (index == NOT_COVERED)) return_trace (false);
+
+    const AlternateSet &alt_set = this+alternateSet[index];
+
+    if (unlikely (!alt_set.len)) return_trace (false);
+
+    hb_mask_t glyph_mask = c->buffer->cur().mask;
+    hb_mask_t lookup_mask = c->lookup_mask;
+
+    /* Note: This breaks badly if two features enabled this lookup together. */
+    unsigned int shift = _hb_ctz (lookup_mask);
+    unsigned int alt_index = ((lookup_mask & glyph_mask) >> shift);
+
+    if (unlikely (alt_index > alt_set.len || alt_index == 0)) return_trace (false);
+
+    glyph_id = alt_set[alt_index - 1];
+
+    c->replace_glyph (glyph_id);
+
+    return_trace (true);
+  }
+
+  inline bool serialize (hb_serialize_context_t *c,
+			 Supplier<GlyphID> &glyphs,
+			 Supplier<unsigned int> &alternate_len_list,
+			 unsigned int num_glyphs,
+			 Supplier<GlyphID> &alternate_glyphs_list)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (*this))) return_trace (false);
+    if (unlikely (!alternateSet.serialize (c, num_glyphs))) return_trace (false);
+    for (unsigned int i = 0; i < num_glyphs; i++)
+      if (unlikely (!alternateSet[i].serialize (c, this).serialize (c,
+								    alternate_glyphs_list,
+								    alternate_len_list[i]))) return_trace (false);
+    alternate_len_list.advance (num_glyphs);
+    if (unlikely (!coverage.serialize (c, this).serialize (c, glyphs, num_glyphs))) return_trace (false);
+    return_trace (true);
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (coverage.sanitize (c, this) && alternateSet.sanitize (c, this));
+  }
+
+  protected:
+  USHORT	format;			/* Format identifier--format = 1 */
+  OffsetTo<Coverage>
+		coverage;		/* Offset to Coverage table--from
+					 * beginning of Substitution table */
+  OffsetArrayOf<AlternateSet>
+		alternateSet;		/* Array of AlternateSet tables
+					 * ordered by Coverage Index */
+  public:
+  DEFINE_SIZE_ARRAY (6, alternateSet);
+};
+
+struct AlternateSubst
+{
+  inline bool serialize (hb_serialize_context_t *c,
+			 Supplier<GlyphID> &glyphs,
+			 Supplier<unsigned int> &alternate_len_list,
+			 unsigned int num_glyphs,
+			 Supplier<GlyphID> &alternate_glyphs_list)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (u.format))) return_trace (false);
+    unsigned int format = 1;
+    u.format.set (format);
+    switch (u.format) {
+    case 1: return_trace (u.format1.serialize (c, glyphs, alternate_len_list, num_glyphs, alternate_glyphs_list));
+    default:return_trace (false);
+    }
+  }
+
+  template <typename context_t>
+  inline typename context_t::return_t dispatch (context_t *c) const
+  {
+    TRACE_DISPATCH (this, u.format);
+    if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
+    switch (u.format) {
+    case 1: return_trace (c->dispatch (u.format1));
+    default:return_trace (c->default_return_value ());
+    }
+  }
+
+  protected:
+  union {
+  USHORT		format;		/* Format identifier */
+  AlternateSubstFormat1	format1;
+  } u;
+};
+
+
+struct Ligature
+{
+  inline void closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE (this);
+    unsigned int count = component.len;
+    for (unsigned int i = 1; i < count; i++)
+      if (!c->glyphs->has (component[i]))
+        return;
+    c->glyphs->add (ligGlyph);
+  }
+
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    TRACE_COLLECT_GLYPHS (this);
+    unsigned int count = component.len;
+    for (unsigned int i = 1; i < count; i++)
+      c->input->add (component[i]);
+    c->output->add (ligGlyph);
+  }
+
+  inline bool would_apply (hb_would_apply_context_t *c) const
+  {
+    TRACE_WOULD_APPLY (this);
+    if (c->len != component.len)
+      return_trace (false);
+
+    for (unsigned int i = 1; i < c->len; i++)
+      if (likely (c->glyphs[i] != component[i]))
+	return_trace (false);
+
+    return_trace (true);
+  }
+
+  inline bool apply (hb_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+    unsigned int count = component.len;
+
+    if (unlikely (!count)) return_trace (false);
+
+    /* Special-case to make it in-place and not consider this
+     * as a "ligated" substitution. */
+    if (unlikely (count == 1))
+    {
+      c->replace_glyph (ligGlyph);
+      return_trace (true);
+    }
+
+    bool is_mark_ligature = false;
+    unsigned int total_component_count = 0;
+
+    unsigned int match_length = 0;
+    unsigned int match_positions[HB_MAX_CONTEXT_LENGTH];
+
+    if (likely (!match_input (c, count,
+			      &component[1],
+			      match_glyph,
+			      NULL,
+			      &match_length,
+			      match_positions,
+			      &is_mark_ligature,
+			      &total_component_count)))
+      return_trace (false);
+
+    ligate_input (c,
+		  count,
+		  match_positions,
+		  match_length,
+		  ligGlyph,
+		  is_mark_ligature,
+		  total_component_count);
+
+    return_trace (true);
+  }
+
+  inline bool serialize (hb_serialize_context_t *c,
+			 GlyphID ligature,
+			 Supplier<GlyphID> &components, /* Starting from second */
+			 unsigned int num_components /* Including first component */)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (*this))) return_trace (false);
+    ligGlyph = ligature;
+    if (unlikely (!component.serialize (c, components, num_components))) return_trace (false);
+    return_trace (true);
+  }
+
+  public:
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (ligGlyph.sanitize (c) && component.sanitize (c));
+  }
+
+  protected:
+  GlyphID	ligGlyph;		/* GlyphID of ligature to substitute */
+  HeadlessArrayOf<GlyphID>
+		component;		/* Array of component GlyphIDs--start
+					 * with the second  component--ordered
+					 * in writing direction */
+  public:
+  DEFINE_SIZE_ARRAY (4, component);
+};
+
+struct LigatureSet
+{
+  inline void closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE (this);
+    unsigned int num_ligs = ligature.len;
+    for (unsigned int i = 0; i < num_ligs; i++)
+      (this+ligature[i]).closure (c);
+  }
+
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    TRACE_COLLECT_GLYPHS (this);
+    unsigned int num_ligs = ligature.len;
+    for (unsigned int i = 0; i < num_ligs; i++)
+      (this+ligature[i]).collect_glyphs (c);
+  }
+
+  inline bool would_apply (hb_would_apply_context_t *c) const
+  {
+    TRACE_WOULD_APPLY (this);
+    unsigned int num_ligs = ligature.len;
+    for (unsigned int i = 0; i < num_ligs; i++)
+    {
+      const Ligature &lig = this+ligature[i];
+      if (lig.would_apply (c))
+        return_trace (true);
+    }
+    return_trace (false);
+  }
+
+  inline bool apply (hb_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+    unsigned int num_ligs = ligature.len;
+    for (unsigned int i = 0; i < num_ligs; i++)
+    {
+      const Ligature &lig = this+ligature[i];
+      if (lig.apply (c)) return_trace (true);
+    }
+
+    return_trace (false);
+  }
+
+  inline bool serialize (hb_serialize_context_t *c,
+			 Supplier<GlyphID> &ligatures,
+			 Supplier<unsigned int> &component_count_list,
+			 unsigned int num_ligatures,
+			 Supplier<GlyphID> &component_list /* Starting from second for each ligature */)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (*this))) return_trace (false);
+    if (unlikely (!ligature.serialize (c, num_ligatures))) return_trace (false);
+    for (unsigned int i = 0; i < num_ligatures; i++)
+      if (unlikely (!ligature[i].serialize (c, this).serialize (c,
+								ligatures[i],
+								component_list,
+								component_count_list[i]))) return_trace (false);
+    ligatures.advance (num_ligatures);
+    component_count_list.advance (num_ligatures);
+    return_trace (true);
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (ligature.sanitize (c, this));
+  }
+
+  protected:
+  OffsetArrayOf<Ligature>
+		ligature;		/* Array LigatureSet tables
+					 * ordered by preference */
+  public:
+  DEFINE_SIZE_ARRAY (2, ligature);
+};
+
+struct LigatureSubstFormat1
+{
+  inline void closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE (this);
+    Coverage::Iter iter;
+    unsigned int count = ligatureSet.len;
+    for (iter.init (this+coverage); iter.more (); iter.next ())
+    {
+      if (unlikely (iter.get_coverage () >= count))
+        break; /* Work around malicious fonts. https://github.com/behdad/harfbuzz/issues/363 */
+      if (c->glyphs->has (iter.get_glyph ()))
+	(this+ligatureSet[iter.get_coverage ()]).closure (c);
+    }
+  }
+
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    TRACE_COLLECT_GLYPHS (this);
+    Coverage::Iter iter;
+    unsigned int count = ligatureSet.len;
+    for (iter.init (this+coverage); iter.more (); iter.next ())
+    {
+      if (unlikely (iter.get_coverage () >= count))
+        break; /* Work around malicious fonts. https://github.com/behdad/harfbuzz/issues/363 */
+      c->input->add (iter.get_glyph ());
+      (this+ligatureSet[iter.get_coverage ()]).collect_glyphs (c);
+    }
+  }
+
+  inline const Coverage &get_coverage (void) const
+  {
+    return this+coverage;
+  }
+
+  inline bool would_apply (hb_would_apply_context_t *c) const
+  {
+    TRACE_WOULD_APPLY (this);
+    unsigned int index = (this+coverage).get_coverage (c->glyphs[0]);
+    if (likely (index == NOT_COVERED)) return_trace (false);
+
+    const LigatureSet &lig_set = this+ligatureSet[index];
+    return_trace (lig_set.would_apply (c));
+  }
+
+  inline bool apply (hb_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+    hb_codepoint_t glyph_id = c->buffer->cur().codepoint;
+
+    unsigned int index = (this+coverage).get_coverage (glyph_id);
+    if (likely (index == NOT_COVERED)) return_trace (false);
+
+    const LigatureSet &lig_set = this+ligatureSet[index];
+    return_trace (lig_set.apply (c));
+  }
+
+  inline bool serialize (hb_serialize_context_t *c,
+			 Supplier<GlyphID> &first_glyphs,
+			 Supplier<unsigned int> &ligature_per_first_glyph_count_list,
+			 unsigned int num_first_glyphs,
+			 Supplier<GlyphID> &ligatures_list,
+			 Supplier<unsigned int> &component_count_list,
+			 Supplier<GlyphID> &component_list /* Starting from second for each ligature */)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (*this))) return_trace (false);
+    if (unlikely (!ligatureSet.serialize (c, num_first_glyphs))) return_trace (false);
+    for (unsigned int i = 0; i < num_first_glyphs; i++)
+      if (unlikely (!ligatureSet[i].serialize (c, this).serialize (c,
+								   ligatures_list,
+								   component_count_list,
+								   ligature_per_first_glyph_count_list[i],
+								   component_list))) return_trace (false);
+    ligature_per_first_glyph_count_list.advance (num_first_glyphs);
+    if (unlikely (!coverage.serialize (c, this).serialize (c, first_glyphs, num_first_glyphs))) return_trace (false);
+    return_trace (true);
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (coverage.sanitize (c, this) && ligatureSet.sanitize (c, this));
+  }
+
+  protected:
+  USHORT	format;			/* Format identifier--format = 1 */
+  OffsetTo<Coverage>
+		coverage;		/* Offset to Coverage table--from
+					 * beginning of Substitution table */
+  OffsetArrayOf<LigatureSet>
+		ligatureSet;		/* Array LigatureSet tables
+					 * ordered by Coverage Index */
+  public:
+  DEFINE_SIZE_ARRAY (6, ligatureSet);
+};
+
+struct LigatureSubst
+{
+  inline bool serialize (hb_serialize_context_t *c,
+			 Supplier<GlyphID> &first_glyphs,
+			 Supplier<unsigned int> &ligature_per_first_glyph_count_list,
+			 unsigned int num_first_glyphs,
+			 Supplier<GlyphID> &ligatures_list,
+			 Supplier<unsigned int> &component_count_list,
+			 Supplier<GlyphID> &component_list /* Starting from second for each ligature */)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (u.format))) return_trace (false);
+    unsigned int format = 1;
+    u.format.set (format);
+    switch (u.format) {
+    case 1: return_trace (u.format1.serialize (c,
+					       first_glyphs,
+					       ligature_per_first_glyph_count_list,
+					       num_first_glyphs,
+					       ligatures_list,
+					       component_count_list,
+					       component_list));
+    default:return_trace (false);
+    }
+  }
+
+  template <typename context_t>
+  inline typename context_t::return_t dispatch (context_t *c) const
+  {
+    TRACE_DISPATCH (this, u.format);
+    if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
+    switch (u.format) {
+    case 1: return_trace (c->dispatch (u.format1));
+    default:return_trace (c->default_return_value ());
+    }
+  }
+
+  protected:
+  union {
+  USHORT		format;		/* Format identifier */
+  LigatureSubstFormat1	format1;
+  } u;
+};
+
+
+struct ContextSubst : Context {};
+
+struct ChainContextSubst : ChainContext {};
+
+struct ExtensionSubst : Extension<ExtensionSubst>
+{
+  typedef struct SubstLookupSubTable LookupSubTable;
+
+  inline bool is_reverse (void) const;
+};
+
+
+struct ReverseChainSingleSubstFormat1
+{
+  inline void closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE (this);
+    const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
+
+    unsigned int count;
+
+    count = backtrack.len;
+    for (unsigned int i = 0; i < count; i++)
+      if (!(this+backtrack[i]).intersects (c->glyphs))
+        return;
+
+    count = lookahead.len;
+    for (unsigned int i = 0; i < count; i++)
+      if (!(this+lookahead[i]).intersects (c->glyphs))
+        return;
+
+    const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
+    Coverage::Iter iter;
+    count = substitute.len;
+    for (iter.init (this+coverage); iter.more (); iter.next ())
+    {
+      if (unlikely (iter.get_coverage () >= count))
+        break; /* Work around malicious fonts. https://github.com/behdad/harfbuzz/issues/363 */
+      if (c->glyphs->has (iter.get_glyph ()))
+	c->glyphs->add (substitute[iter.get_coverage ()]);
+    }
+  }
+
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    TRACE_COLLECT_GLYPHS (this);
+
+    const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
+
+    unsigned int count;
+
+    (this+coverage).add_coverage (c->input);
+
+    count = backtrack.len;
+    for (unsigned int i = 0; i < count; i++)
+      (this+backtrack[i]).add_coverage (c->before);
+
+    count = lookahead.len;
+    for (unsigned int i = 0; i < count; i++)
+      (this+lookahead[i]).add_coverage (c->after);
+
+    const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
+    count = substitute.len;
+    for (unsigned int i = 0; i < count; i++)
+      c->output->add (substitute[i]);
+  }
+
+  inline const Coverage &get_coverage (void) const
+  {
+    return this+coverage;
+  }
+
+  inline bool would_apply (hb_would_apply_context_t *c) const
+  {
+    TRACE_WOULD_APPLY (this);
+    return_trace (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
+  }
+
+  inline bool apply (hb_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+    if (unlikely (c->nesting_level_left != HB_MAX_NESTING_LEVEL))
+      return_trace (false); /* No chaining to this type */
+
+    unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
+    if (likely (index == NOT_COVERED)) return_trace (false);
+
+    const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
+    const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
+
+    if (match_backtrack (c,
+			 backtrack.len, (USHORT *) backtrack.array,
+			 match_coverage, this) &&
+        match_lookahead (c,
+			 lookahead.len, (USHORT *) lookahead.array,
+			 match_coverage, this,
+			 1))
+    {
+      c->replace_glyph_inplace (substitute[index]);
+      /* Note: We DON'T decrease buffer->idx.  The main loop does it
+       * for us.  This is useful for preventing surprises if someone
+       * calls us through a Context lookup. */
+      return_trace (true);
+    }
+
+    return_trace (false);
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    if (!(coverage.sanitize (c, this) && backtrack.sanitize (c, this)))
+      return_trace (false);
+    const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
+    if (!lookahead.sanitize (c, this))
+      return_trace (false);
+    const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
+    return_trace (substitute.sanitize (c));
+  }
+
+  protected:
+  USHORT	format;			/* Format identifier--format = 1 */
+  OffsetTo<Coverage>
+		coverage;		/* Offset to Coverage table--from
+					 * beginning of table */
+  OffsetArrayOf<Coverage>
+		backtrack;		/* Array of coverage tables
+					 * in backtracking sequence, in  glyph
+					 * sequence order */
+  OffsetArrayOf<Coverage>
+		lookaheadX;		/* Array of coverage tables
+					 * in lookahead sequence, in glyph
+					 * sequence order */
+  ArrayOf<GlyphID>
+		substituteX;		/* Array of substitute
+					 * GlyphIDs--ordered by Coverage Index */
+  public:
+  DEFINE_SIZE_MIN (10);
+};
+
+struct ReverseChainSingleSubst
+{
+  template <typename context_t>
+  inline typename context_t::return_t dispatch (context_t *c) const
+  {
+    TRACE_DISPATCH (this, u.format);
+    if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
+    switch (u.format) {
+    case 1: return_trace (c->dispatch (u.format1));
+    default:return_trace (c->default_return_value ());
+    }
+  }
+
+  protected:
+  union {
+  USHORT				format;		/* Format identifier */
+  ReverseChainSingleSubstFormat1	format1;
+  } u;
+};
+
+
+
+/*
+ * SubstLookup
+ */
+
+struct SubstLookupSubTable
+{
+  friend struct SubstLookup;
+
+  enum Type {
+    Single		= 1,
+    Multiple		= 2,
+    Alternate		= 3,
+    Ligature		= 4,
+    Context		= 5,
+    ChainContext	= 6,
+    Extension		= 7,
+    ReverseChainSingle	= 8
+  };
+
+  template <typename context_t>
+  inline typename context_t::return_t dispatch (context_t *c, unsigned int lookup_type) const
+  {
+    TRACE_DISPATCH (this, lookup_type);
+    if (unlikely (!c->may_dispatch (this, &u.sub_format))) return_trace (c->no_dispatch_return_value ());
+    switch (lookup_type) {
+    case Single:		return_trace (u.single.dispatch (c));
+    case Multiple:		return_trace (u.multiple.dispatch (c));
+    case Alternate:		return_trace (u.alternate.dispatch (c));
+    case Ligature:		return_trace (u.ligature.dispatch (c));
+    case Context:		return_trace (u.context.dispatch (c));
+    case ChainContext:		return_trace (u.chainContext.dispatch (c));
+    case Extension:		return_trace (u.extension.dispatch (c));
+    case ReverseChainSingle:	return_trace (u.reverseChainContextSingle.dispatch (c));
+    default:			return_trace (c->default_return_value ());
+    }
+  }
+
+  protected:
+  union {
+  USHORT			sub_format;
+  SingleSubst			single;
+  MultipleSubst			multiple;
+  AlternateSubst		alternate;
+  LigatureSubst			ligature;
+  ContextSubst			context;
+  ChainContextSubst		chainContext;
+  ExtensionSubst		extension;
+  ReverseChainSingleSubst	reverseChainContextSingle;
+  } u;
+  public:
+  DEFINE_SIZE_UNION (2, sub_format);
+};
+
+
+struct SubstLookup : Lookup
+{
+  inline const SubstLookupSubTable& get_subtable (unsigned int i) const
+  { return Lookup::get_subtable<SubstLookupSubTable> (i); }
+
+  inline static bool lookup_type_is_reverse (unsigned int lookup_type)
+  { return lookup_type == SubstLookupSubTable::ReverseChainSingle; }
+
+  inline bool is_reverse (void) const
+  {
+    unsigned int type = get_type ();
+    if (unlikely (type == SubstLookupSubTable::Extension))
+      return CastR<ExtensionSubst> (get_subtable(0)).is_reverse ();
+    return lookup_type_is_reverse (type);
+  }
+
+  inline bool apply (hb_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+    return_trace (dispatch (c));
+  }
+
+  inline hb_closure_context_t::return_t closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE (this);
+    c->set_recurse_func (dispatch_recurse_func<hb_closure_context_t>);
+    return_trace (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 (dispatch_recurse_func<hb_collect_glyphs_context_t>);
+    return_trace (dispatch (c));
+  }
+
+  template <typename set_t>
+  inline void add_coverage (set_t *glyphs) const
+  {
+    hb_add_coverage_context_t<set_t> c (glyphs);
+    dispatch (&c);
+  }
+
+  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 (false);
+    if (!accel->may_have (c->glyphs[0]))  return_trace (false);
+      return_trace (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 get_subtables<SubstLookupSubTable> ()[i].serialize (c, this); }
+
+  inline bool serialize_single (hb_serialize_context_t *c,
+				uint32_t lookup_props,
+			        Supplier<GlyphID> &glyphs,
+			        Supplier<GlyphID> &substitutes,
+			        unsigned int num_glyphs)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!Lookup::serialize (c, SubstLookupSubTable::Single, lookup_props, 1))) return_trace (false);
+    return_trace (serialize_subtable (c, 0).u.single.serialize (c, glyphs, substitutes, num_glyphs));
+  }
+
+  inline bool serialize_multiple (hb_serialize_context_t *c,
+				  uint32_t lookup_props,
+				  Supplier<GlyphID> &glyphs,
+				  Supplier<unsigned int> &substitute_len_list,
+				  unsigned int num_glyphs,
+				  Supplier<GlyphID> &substitute_glyphs_list)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!Lookup::serialize (c, SubstLookupSubTable::Multiple, lookup_props, 1))) return_trace (false);
+    return_trace (serialize_subtable (c, 0).u.multiple.serialize (c,
+								  glyphs,
+								  substitute_len_list,
+								  num_glyphs,
+								  substitute_glyphs_list));
+  }
+
+  inline bool serialize_alternate (hb_serialize_context_t *c,
+				   uint32_t lookup_props,
+				   Supplier<GlyphID> &glyphs,
+				   Supplier<unsigned int> &alternate_len_list,
+				   unsigned int num_glyphs,
+				   Supplier<GlyphID> &alternate_glyphs_list)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!Lookup::serialize (c, SubstLookupSubTable::Alternate, lookup_props, 1))) return_trace (false);
+    return_trace (serialize_subtable (c, 0).u.alternate.serialize (c,
+								   glyphs,
+								   alternate_len_list,
+								   num_glyphs,
+								   alternate_glyphs_list));
+  }
+
+  inline bool serialize_ligature (hb_serialize_context_t *c,
+				  uint32_t lookup_props,
+				  Supplier<GlyphID> &first_glyphs,
+				  Supplier<unsigned int> &ligature_per_first_glyph_count_list,
+				  unsigned int num_first_glyphs,
+				  Supplier<GlyphID> &ligatures_list,
+				  Supplier<unsigned int> &component_count_list,
+				  Supplier<GlyphID> &component_list /* Starting from second for each ligature */)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!Lookup::serialize (c, SubstLookupSubTable::Ligature, lookup_props, 1))) return_trace (false);
+    return_trace (serialize_subtable (c, 0).u.ligature.serialize (c,
+								  first_glyphs,
+								  ligature_per_first_glyph_count_list,
+								  num_first_glyphs,
+								  ligatures_list,
+								  component_count_list,
+								  component_list));
+  }
+
+  template <typename context_t>
+  static inline typename context_t::return_t dispatch_recurse_func (context_t *c, unsigned int lookup_index);
+
+  template <typename context_t>
+  inline typename context_t::return_t dispatch (context_t *c) const
+  { return Lookup::dispatch<SubstLookupSubTable> (c); }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    if (unlikely (!Lookup::sanitize (c))) return_trace (false);
+    if (unlikely (!dispatch (c))) return_trace (false);
+
+    if (unlikely (get_type () == SubstLookupSubTable::Extension))
+    {
+      /* The spec says all subtables of an Extension lookup should
+       * have the same type.  This is specially important if one has
+       * a reverse type! */
+      unsigned int type = get_subtable (0).u.extension.get_type ();
+      unsigned int count = get_subtable_count ();
+      for (unsigned int i = 1; i < count; i++)
+        if (get_subtable (i).u.extension.get_type () != type)
+	  return_trace (false);
+    }
+    return_trace (true);
+  }
+};
+
+typedef OffsetListOf<SubstLookup> SubstLookupList;
+
+/*
+ * GSUB -- The Glyph Substitution Table
+ */
+
+struct GSUB : GSUBGPOS
+{
+  static const hb_tag_t tableTag	= HB_OT_TAG_GSUB;
+
+  inline const SubstLookup& get_lookup (unsigned int i) const
+  { return CastR<SubstLookup> (GSUBGPOS::get_lookup (i)); }
+
+  static inline void substitute_start (hb_font_t *font, hb_buffer_t *buffer);
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    if (unlikely (!GSUBGPOS::sanitize (c))) return_trace (false);
+    const OffsetTo<SubstLookupList> &list = CastR<OffsetTo<SubstLookupList> > (lookupList);
+    return_trace (list.sanitize (c, this));
+  }
+};
+
+
+void
+GSUB::substitute_start (hb_font_t *font, hb_buffer_t *buffer)
+{
+  _hb_buffer_assert_gsubgpos_vars (buffer);
+
+  const GDEF &gdef = *hb_ot_layout_from_face (font->face)->gdef;
+  unsigned int count = buffer->len;
+  for (unsigned int i = 0; i < count; i++)
+  {
+    _hb_glyph_info_set_glyph_props (&buffer->info[i], gdef.get_glyph_props (buffer->info[i].codepoint));
+    _hb_glyph_info_clear_lig_props (&buffer->info[i]);
+    buffer->info[i].syllable() = 0;
+  }
+}
+
+
+/* Out-of-class implementation for methods recursing */
+
+/*static*/ inline bool ExtensionSubst::is_reverse (void) const
+{
+  unsigned int type = get_type ();
+  if (unlikely (type == SubstLookupSubTable::Extension))
+    return CastR<ExtensionSubst> (get_subtable<LookupSubTable>()).is_reverse ();
+  return SubstLookup::lookup_type_is_reverse (type);
+}
+
+template <typename context_t>
+/*static*/ inline typename context_t::return_t SubstLookup::dispatch_recurse_func (context_t *c, unsigned int lookup_index)
+{
+  const GSUB &gsub = *(hb_ot_layout_from_face (c->face)->gsub);
+  const SubstLookup &l = gsub.get_lookup (lookup_index);
+  return l.dispatch (c);
+}
+
+/*static*/ inline bool SubstLookup::apply_recurse_func (hb_apply_context_t *c, unsigned int lookup_index)
+{
+  const GSUB &gsub = *(hb_ot_layout_from_face (c->face)->gsub);
+  const SubstLookup &l = gsub.get_lookup (lookup_index);
+  unsigned int saved_lookup_props = c->lookup_props;
+  unsigned int saved_lookup_index = c->lookup_index;
+  c->set_lookup_index (lookup_index);
+  c->set_lookup_props (l.get_props ());
+  bool ret = l.dispatch (c);
+  c->set_lookup_index (saved_lookup_index);
+  c->set_lookup_props (saved_lookup_props);
+  return ret;
+}
+
+
+} /* namespace OT */
+
+
+#endif /* HB_OT_LAYOUT_GSUB_TABLE_HH */