1 files changed, 303 insertions, 149 deletions

diff --git a/src/3rdparty/harfbuzz-ng/src/hb-ot-shape.cc b/src/3rdparty/harfbuzz-ng/src/hb-ot-shape.cc
index 5d9a70cda2..90f596ae79 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-ot-shape.cc
+++ b/src/3rdparty/harfbuzz-ng/src/hb-ot-shape.cc
@@ -37,7 +37,7 @@
 #include "hb-shaper-impl.hh"
 
 #include "hb-ot-shape.hh"
-#include "hb-ot-shape-complex.hh"
+#include "hb-ot-shaper.hh"
 #include "hb-ot-shape-fallback.hh"
 #include "hb-ot-shape-normalize.hh"
 
@@ -47,6 +47,19 @@
 
 #include "hb-aat-layout.hh"
 
+static inline bool
+_hb_codepoint_is_regional_indicator (hb_codepoint_t u)
+{ return hb_in_range<hb_codepoint_t> (u, 0x1F1E6u, 0x1F1FFu); }
+
+#ifndef HB_NO_AAT_SHAPE
+static inline bool
+_hb_apply_morx (hb_face_t *face, const hb_segment_properties_t &props)
+{
+  /* https://github.com/harfbuzz/harfbuzz/issues/2124 */
+  return hb_aat_layout_has_substitution (face) &&
+	 (HB_DIRECTION_IS_HORIZONTAL (props.direction) || !hb_ot_layout_has_substitution (face));
+}
+#endif
 
 /**
  * SECTION:hb-ot-shape
@@ -63,40 +76,25 @@ hb_ot_shape_collect_features (hb_ot_shape_planner_t          *planner,
 			      const hb_feature_t             *user_features,
 			      unsigned int                    num_user_features);
 
-#ifndef HB_NO_AAT_SHAPE
-static inline bool
-_hb_apply_morx (hb_face_t *face)
-{
-  if (hb_options ().aat &&
-      hb_aat_layout_has_substitution (face))
-    return true;
-
-  /* Ignore empty GSUB tables. */
-  return (!hb_ot_layout_has_substitution (face) ||
-	  !hb_ot_layout_table_get_script_tags (face,
-					       HB_OT_TAG_GSUB,
-					       0, nullptr, nullptr)) &&
-	 hb_aat_layout_has_substitution (face);
-}
-#endif
-
 hb_ot_shape_planner_t::hb_ot_shape_planner_t (hb_face_t                     *face,
-					      const hb_segment_properties_t *props) :
+					      const hb_segment_properties_t &props) :
 						face (face),
-						props (*props),
-						map (face, props),
-						aat_map (face, props)
+						props (props),
+						map (face, props)
 #ifndef HB_NO_AAT_SHAPE
-						, apply_morx (_hb_apply_morx (face))
+						, apply_morx (_hb_apply_morx (face, props))
 #endif
 {
-  shaper = hb_ot_shape_complex_categorize (this);
+  shaper = hb_ot_shaper_categorize (this);
 
   script_zero_marks = shaper->zero_width_marks != HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE;
   script_fallback_mark_positioning = shaper->fallback_position;
 
-  if (apply_morx)
-    shaper = &_hb_ot_complex_shaper_default;
+#ifndef HB_NO_AAT_SHAPE
+  /* https://github.com/harfbuzz/harfbuzz/issues/1528 */
+  if (apply_morx && shaper != &_hb_ot_shaper_default)
+    shaper = &_hb_ot_shaper_dumber;
+#endif
 }
 
 void
@@ -106,10 +104,6 @@ hb_ot_shape_planner_t::compile (hb_ot_shape_plan_t           &plan,
   plan.props = props;
   plan.shaper = shaper;
   map.compile (plan.map, key);
-#ifndef HB_NO_AAT_SHAPE
-  if (apply_morx)
-    aat_map.compile (plan.aat_map);
-#endif
 
 #ifndef HB_NO_OT_SHAPE_FRACTIONS
   plan.frac_mask = plan.map.get_1_mask (HB_TAG ('f','r','a','c'));
@@ -119,6 +113,8 @@ hb_ot_shape_planner_t::compile (hb_ot_shape_plan_t           &plan,
 #endif
 
   plan.rtlm_mask = plan.map.get_1_mask (HB_TAG ('r','t','l','m'));
+  plan.has_vert = !!plan.map.get_1_mask (HB_TAG ('v','e','r','t'));
+
   hb_tag_t kern_tag = HB_DIRECTION_IS_HORIZONTAL (props.direction) ?
 		      HB_TAG ('k','e','r','n') : HB_TAG ('v','k','r','n');
 #ifndef HB_NO_OT_KERN
@@ -153,24 +149,26 @@ hb_ot_shape_planner_t::compile (hb_ot_shape_plan_t           &plan,
    * Decide who does positioning. GPOS, kerx, kern, or fallback.
    */
 
-  if (0)
-    ;
 #ifndef HB_NO_AAT_SHAPE
-  else if (hb_options ().aat && hb_aat_layout_has_positioning (face))
-    plan.apply_kerx = true;
+  bool has_kerx = hb_aat_layout_has_positioning (face);
+  bool has_gsub = !apply_morx && hb_ot_layout_has_substitution (face);
 #endif
-  else if (!apply_morx && !disable_gpos && hb_ot_layout_has_positioning (face))
-    plan.apply_gpos = true;
+  bool has_gpos = !disable_gpos && hb_ot_layout_has_positioning (face);
+  if (false)
+    ;
 #ifndef HB_NO_AAT_SHAPE
-  else if (hb_aat_layout_has_positioning (face))
+  /* Prefer GPOS over kerx if GSUB is present;
+   * https://github.com/harfbuzz/harfbuzz/issues/3008 */
+  else if (has_kerx && !(has_gsub && has_gpos))
     plan.apply_kerx = true;
 #endif
+  else if (has_gpos)
+    plan.apply_gpos = true;
 
-  if (!plan.apply_kerx && !has_gpos_kern)
+  if (!plan.apply_kerx && (!has_gpos_kern || !plan.apply_gpos))
   {
-    /* Apparently Apple applies kerx if GPOS kern was not applied. */
 #ifndef HB_NO_AAT_SHAPE
-    if (hb_aat_layout_has_positioning (face))
+    if (has_kerx)
       plan.apply_kerx = true;
     else
 #endif
@@ -180,6 +178,8 @@ hb_ot_shape_planner_t::compile (hb_ot_shape_plan_t           &plan,
 #endif
   }
 
+  plan.apply_fallback_kern = !(plan.apply_gpos || plan.apply_kerx || plan.apply_kern);
+
   plan.zero_marks = script_zero_marks &&
 		    !plan.apply_kerx &&
 		    (!plan.apply_kern
@@ -201,6 +201,12 @@ hb_ot_shape_planner_t::compile (hb_ot_shape_plan_t           &plan,
 				   script_fallback_mark_positioning;
 
 #ifndef HB_NO_AAT_SHAPE
+  /* If we're using morx shaping, we cancel mark position adjustment because
+     Apple Color Emoji assumes this will NOT be done when forming emoji sequences;
+     https://github.com/harfbuzz/harfbuzz/issues/2967. */
+  if (plan.apply_morx)
+    plan.adjust_mark_positioning_when_zeroing = false;
+
   /* Currently we always apply trak. */
   plan.apply_trak = plan.requested_tracking && hb_aat_layout_has_tracking (face);
 #endif
@@ -211,12 +217,9 @@ hb_ot_shape_plan_t::init0 (hb_face_t                     *face,
 			   const hb_shape_plan_key_t     *key)
 {
   map.init ();
-#ifndef HB_NO_AAT_SHAPE
-  aat_map.init ();
-#endif
 
   hb_ot_shape_planner_t planner (face,
-				 &key->props);
+				 key->props);
 
   hb_ot_shape_collect_features (&planner,
 				key->user_features,
@@ -228,7 +231,10 @@ hb_ot_shape_plan_t::init0 (hb_face_t                     *face,
   {
     data = shaper->data_create (this);
     if (unlikely (!data))
+    {
+      map.fini ();
       return false;
+    }
   }
 
   return true;
@@ -241,21 +247,13 @@ hb_ot_shape_plan_t::fini ()
     shaper->data_destroy (const_cast<void *> (data));
 
   map.fini ();
-#ifndef HB_NO_AAT_SHAPE
-  aat_map.fini ();
-#endif
 }
 
 void
 hb_ot_shape_plan_t::substitute (hb_font_t   *font,
 				hb_buffer_t *buffer) const
 {
-#ifndef HB_NO_AAT_SHAPE
-  if (unlikely (apply_morx))
-    hb_aat_layout_substitute (this, font, buffer);
-  else
-#endif
-    map.substitute (this, font, buffer);
+  map.substitute (this, font, buffer);
 }
 
 void
@@ -268,11 +266,12 @@ hb_ot_shape_plan_t::position (hb_font_t   *font,
   else if (this->apply_kerx)
     hb_aat_layout_position (this, font, buffer);
 #endif
+
 #ifndef HB_NO_OT_KERN
-  else if (this->apply_kern)
+  if (this->apply_kern)
     hb_ot_layout_kern (this, font, buffer);
 #endif
-  else
+  else if (this->apply_fallback_kern)
     _hb_ot_shape_fallback_kern (this, font, buffer);
 
 #ifndef HB_NO_AAT_SHAPE
@@ -308,16 +307,19 @@ horizontal_features[] =
 };
 
 static void
-hb_ot_shape_collect_features (hb_ot_shape_planner_t          *planner,
-			      const hb_feature_t             *user_features,
-			      unsigned int                    num_user_features)
+hb_ot_shape_collect_features (hb_ot_shape_planner_t *planner,
+			      const hb_feature_t    *user_features,
+			      unsigned int           num_user_features)
 {
   hb_ot_map_builder_t *map = &planner->map;
 
+  map->is_simple = true;
+
   map->enable_feature (HB_TAG('r','v','r','n'));
   map->add_gsub_pause (nullptr);
 
-  switch (planner->props.direction) {
+  switch (planner->props.direction)
+  {
     case HB_DIRECTION_LTR:
       map->enable_feature (HB_TAG ('l','t','r','a'));
       map->enable_feature (HB_TAG ('l','t','r','m'));
@@ -350,12 +352,17 @@ hb_ot_shape_collect_features (hb_ot_shape_planner_t          *planner,
   map->enable_feature (HB_TAG ('t','r','a','k'), F_HAS_FALLBACK);
 #endif
 
-  map->enable_feature (HB_TAG ('H','A','R','F'));
+  map->enable_feature (HB_TAG ('H','a','r','f')); /* Considered required. */
+  map->enable_feature (HB_TAG ('H','A','R','F')); /* Considered discretionary. */
 
   if (planner->shaper->collect_features)
+  {
+    map->is_simple = false;
     planner->shaper->collect_features (planner);
+  }
 
-  map->enable_feature (HB_TAG ('B','U','Z','Z'));
+  map->enable_feature (HB_TAG ('B','u','z','z')); /* Considered required. */
+  map->enable_feature (HB_TAG ('B','U','Z','Z')); /* Considered discretionary. */
 
   for (unsigned int i = 0; i < ARRAY_LENGTH (common_features); i++)
     map->add_feature (common_features[i]);
@@ -365,6 +372,10 @@ hb_ot_shape_collect_features (hb_ot_shape_planner_t          *planner,
       map->add_feature (horizontal_features[i]);
   else
   {
+    /* We only apply `vert` feature. See:
+     * https://github.com/harfbuzz/harfbuzz/commit/d71c0df2d17f4590d5611239577a6cb532c26528
+     * https://lists.freedesktop.org/archives/harfbuzz/2013-August/003490.html */
+
     /* We really want to find a 'vert' feature if there's any in the font, no
      * matter which script/langsys it is listed (or not) under.
      * See various bugs referenced from:
@@ -372,6 +383,8 @@ hb_ot_shape_collect_features (hb_ot_shape_planner_t          *planner,
     map->enable_feature (HB_TAG ('v','e','r','t'), F_GLOBAL_SEARCH);
   }
 
+  if (num_user_features)
+    map->is_simple = false;
   for (unsigned int i = 0; i < num_user_features; i++)
   {
     const hb_feature_t *feature = &user_features[i];
@@ -381,18 +394,6 @@ hb_ot_shape_collect_features (hb_ot_shape_planner_t          *planner,
 		      feature->value);
   }
 
-#ifndef HB_NO_AAT_SHAPE
-  if (planner->apply_morx)
-  {
-    hb_aat_map_builder_t *aat_map = &planner->aat_map;
-    for (unsigned int i = 0; i < num_user_features; i++)
-    {
-      const hb_feature_t *feature = &user_features[i];
-      aat_map->add_feature (feature->tag, feature->value);
-    }
-  }
-#endif
-
   if (planner->shaper->override_features)
     planner->shaper->override_features (planner);
 }
@@ -475,11 +476,28 @@ hb_set_unicode_props (hb_buffer_t *buffer)
   {
     _hb_glyph_info_set_unicode_props (&info[i], buffer);
 
+    unsigned gen_cat = _hb_glyph_info_get_general_category (&info[i]);
+    if (FLAG_UNSAFE (gen_cat) &
+	(FLAG (HB_UNICODE_GENERAL_CATEGORY_LOWERCASE_LETTER) |
+	 FLAG (HB_UNICODE_GENERAL_CATEGORY_UPPERCASE_LETTER) |
+	 FLAG (HB_UNICODE_GENERAL_CATEGORY_TITLECASE_LETTER) |
+	 FLAG (HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER) |
+	 FLAG (HB_UNICODE_GENERAL_CATEGORY_SPACE_SEPARATOR)))
+      continue;
+
     /* Marks are already set as continuation by the above line.
      * Handle Emoji_Modifier and ZWJ-continuation. */
-    if (unlikely (_hb_glyph_info_get_general_category (&info[i]) == HB_UNICODE_GENERAL_CATEGORY_MODIFIER_SYMBOL &&
+    if (unlikely (gen_cat == HB_UNICODE_GENERAL_CATEGORY_MODIFIER_SYMBOL &&
 		  hb_in_range<hb_codepoint_t> (info[i].codepoint, 0x1F3FBu, 0x1F3FFu)))
     {
+      _hb_glyph_info_set_continuation (&info[i]);
+    }
+    /* Regional_Indicators are hairy as hell...
+     * https://github.com/harfbuzz/harfbuzz/issues/2265 */
+    else if (unlikely (i && _hb_codepoint_is_regional_indicator (info[i].codepoint)))
+    {
+      if (_hb_codepoint_is_regional_indicator (info[i - 1].codepoint) &&
+	  !_hb_glyph_info_is_continuation (&info[i - 1]))
 	_hb_glyph_info_set_continuation (&info[i]);
     }
 #ifndef HB_NO_EMOJI_SEQUENCES
@@ -496,18 +514,20 @@ hb_set_unicode_props (hb_buffer_t *buffer)
     }
 #endif
     /* Or part of the Other_Grapheme_Extend that is not marks.
-     * As of Unicode 11 that is just:
+     * As of Unicode 15 that is just:
      *
      * 200C          ; Other_Grapheme_Extend # Cf       ZERO WIDTH NON-JOINER
      * FF9E..FF9F    ; Other_Grapheme_Extend # Lm   [2] HALFWIDTH KATAKANA VOICED SOUND MARK..HALFWIDTH KATAKANA SEMI-VOICED SOUND MARK
      * E0020..E007F  ; Other_Grapheme_Extend # Cf  [96] TAG SPACE..CANCEL TAG
      *
      * ZWNJ is special, we don't want to merge it as there's no need, and keeping
-     * it separate results in more granular clusters.  Ignore Katakana for now.
+     * it separate results in more granular clusters.
      * Tags are used for Emoji sub-region flag sequences:
      * https://github.com/harfbuzz/harfbuzz/issues/1556
+     * Katakana ones were requested:
+     * https://github.com/harfbuzz/harfbuzz/issues/3844
      */
-    else if (unlikely (hb_in_range<hb_codepoint_t> (info[i].codepoint, 0xE0020u, 0xE007Fu)))
+    else if (unlikely (hb_in_ranges<hb_codepoint_t> (info[i].codepoint, 0xFF9Eu, 0xFF9Fu, 0xE0020u, 0xE007Fu)))
       _hb_glyph_info_set_continuation (&info[i]);
   }
 }
@@ -536,10 +556,9 @@ hb_insert_dotted_circle (hb_buffer_t *buffer, hb_font_t *font)
   hb_glyph_info_t info = dottedcircle;
   info.cluster = buffer->cur().cluster;
   info.mask = buffer->cur().mask;
-  buffer->output_info (info);
-  while (buffer->idx < buffer->len && buffer->successful)
-    buffer->next_glyph ();
-  buffer->swap_buffers ();
+  (void) buffer->output_info (info);
+
+  buffer->sync ();
 }
 
 static void
@@ -562,6 +581,45 @@ hb_ensure_native_direction (hb_buffer_t *buffer)
   hb_direction_t direction = buffer->props.direction;
   hb_direction_t horiz_dir = hb_script_get_horizontal_direction (buffer->props.script);
 
+  /* Numeric runs in natively-RTL scripts are actually native-LTR, so we reset
+   * the horiz_dir if the run contains at least one decimal-number char, and no
+   * letter chars (ideally we should be checking for chars with strong
+   * directionality but hb-unicode currently lacks bidi categories).
+   *
+   * This allows digit sequences in Arabic etc to be shaped in "native"
+   * direction, so that features like ligatures will work as intended.
+   *
+   * https://github.com/harfbuzz/harfbuzz/issues/501
+   *
+   * Similar thing about Regional_Indicators; They are bidi=L, but Script=Common.
+   * If they are present in a run of natively-RTL text, they get assigned a script
+   * with natively RTL direction, which would result in wrong shaping if we
+   * assign such native RTL direction to them then. Detect that as well.
+   *
+   * https://github.com/harfbuzz/harfbuzz/issues/3314
+   */
+  if (unlikely (horiz_dir == HB_DIRECTION_RTL && direction == HB_DIRECTION_LTR))
+  {
+    bool found_number = false, found_letter = false, found_ri = false;
+    const auto* info = buffer->info;
+    const auto count = buffer->len;
+    for (unsigned i = 0; i < count; i++)
+    {
+      auto gc = _hb_glyph_info_get_general_category (&info[i]);
+      if (gc == HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
+	found_number = true;
+      else if (HB_UNICODE_GENERAL_CATEGORY_IS_LETTER (gc))
+      {
+	found_letter = true;
+	break;
+      }
+      else if (_hb_codepoint_is_regional_indicator (info[i].codepoint))
+	found_ri = true;
+    }
+    if ((found_number || found_ri) && !found_letter)
+      horiz_dir = HB_DIRECTION_LTR;
+  }
+
   /* TODO vertical:
    * The only BTT vertical script is Ogham, but it's not clear to me whether OpenType
    * Ogham fonts are supposed to be implemented BTT or not.  Need to research that
@@ -571,20 +629,7 @@ hb_ensure_native_direction (hb_buffer_t *buffer)
       (HB_DIRECTION_IS_VERTICAL   (direction) &&
        direction != HB_DIRECTION_TTB))
   {
-
-    if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS)
-      foreach_grapheme (buffer, start, end)
-      {
-	buffer->merge_clusters (start, end);
-	buffer->reverse_range (start, end);
-      }
-    else
-      foreach_grapheme (buffer, start, end)
-	/* form_clusters() merged clusters already, we don't merge. */
-	buffer->reverse_range (start, end);
-
-    buffer->reverse ();
-
+    _hb_ot_layout_reverse_graphemes (buffer);
     buffer->props.direction = HB_DIRECTION_REVERSE (buffer->props.direction);
   }
 }
@@ -594,25 +639,90 @@ hb_ensure_native_direction (hb_buffer_t *buffer)
  * Substitute
  */
 
-static inline void
-hb_ot_mirror_chars (const hb_ot_shape_context_t *c)
+#ifndef HB_NO_VERTICAL
+static hb_codepoint_t
+hb_vert_char_for (hb_codepoint_t u)
 {
-  if (HB_DIRECTION_IS_FORWARD (c->target_direction))
-    return;
+  switch (u >> 8)
+  {
+    case 0x20: switch (u) {
+      case 0x2013u: return 0xfe32u; // EN DASH
+      case 0x2014u: return 0xfe31u; // EM DASH
+      case 0x2025u: return 0xfe30u; // TWO DOT LEADER
+      case 0x2026u: return 0xfe19u; // HORIZONTAL ELLIPSIS
+    } break;
+    case 0x30: switch (u) {
+      case 0x3001u: return 0xfe11u; // IDEOGRAPHIC COMMA
+      case 0x3002u: return 0xfe12u; // IDEOGRAPHIC FULL STOP
+      case 0x3008u: return 0xfe3fu; // LEFT ANGLE BRACKET
+      case 0x3009u: return 0xfe40u; // RIGHT ANGLE BRACKET
+      case 0x300au: return 0xfe3du; // LEFT DOUBLE ANGLE BRACKET
+      case 0x300bu: return 0xfe3eu; // RIGHT DOUBLE ANGLE BRACKET
+      case 0x300cu: return 0xfe41u; // LEFT CORNER BRACKET
+      case 0x300du: return 0xfe42u; // RIGHT CORNER BRACKET
+      case 0x300eu: return 0xfe43u; // LEFT WHITE CORNER BRACKET
+      case 0x300fu: return 0xfe44u; // RIGHT WHITE CORNER BRACKET
+      case 0x3010u: return 0xfe3bu; // LEFT BLACK LENTICULAR BRACKET
+      case 0x3011u: return 0xfe3cu; // RIGHT BLACK LENTICULAR BRACKET
+      case 0x3014u: return 0xfe39u; // LEFT TORTOISE SHELL BRACKET
+      case 0x3015u: return 0xfe3au; // RIGHT TORTOISE SHELL BRACKET
+      case 0x3016u: return 0xfe17u; // LEFT WHITE LENTICULAR BRACKET
+      case 0x3017u: return 0xfe18u; // RIGHT WHITE LENTICULAR BRACKET
+    } break;
+    case 0xfe: switch (u) {
+      case 0xfe4fu: return 0xfe34u; // WAVY LOW LINE
+    } break;
+    case 0xff: switch (u) {
+      case 0xff01u: return 0xfe15u; // FULLWIDTH EXCLAMATION MARK
+      case 0xff08u: return 0xfe35u; // FULLWIDTH LEFT PARENTHESIS
+      case 0xff09u: return 0xfe36u; // FULLWIDTH RIGHT PARENTHESIS
+      case 0xff0cu: return 0xfe10u; // FULLWIDTH COMMA
+      case 0xff1au: return 0xfe13u; // FULLWIDTH COLON
+      case 0xff1bu: return 0xfe14u; // FULLWIDTH SEMICOLON
+      case 0xff1fu: return 0xfe16u; // FULLWIDTH QUESTION MARK
+      case 0xff3bu: return 0xfe47u; // FULLWIDTH LEFT SQUARE BRACKET
+      case 0xff3du: return 0xfe48u; // FULLWIDTH RIGHT SQUARE BRACKET
+      case 0xff3fu: return 0xfe33u; // FULLWIDTH LOW LINE
+      case 0xff5bu: return 0xfe37u; // FULLWIDTH LEFT CURLY BRACKET
+      case 0xff5du: return 0xfe38u; // FULLWIDTH RIGHT CURLY BRACKET
+    } break;
+  }
 
-  hb_buffer_t *buffer = c->buffer;
-  hb_unicode_funcs_t *unicode = buffer->unicode;
-  hb_mask_t rtlm_mask = c->plan->rtlm_mask;
+  return u;
+}
+#endif
 
+static inline void
+hb_ot_rotate_chars (const hb_ot_shape_context_t *c)
+{
+  hb_buffer_t *buffer = c->buffer;
   unsigned int count = buffer->len;
   hb_glyph_info_t *info = buffer->info;
-  for (unsigned int i = 0; i < count; i++) {
-    hb_codepoint_t codepoint = unicode->mirroring (info[i].codepoint);
-    if (likely (codepoint == info[i].codepoint || !c->font->has_glyph (codepoint)))
-      info[i].mask |= rtlm_mask;
-    else
-      info[i].codepoint = codepoint;
+
+  if (HB_DIRECTION_IS_BACKWARD (c->target_direction))
+  {
+    hb_unicode_funcs_t *unicode = buffer->unicode;
+    hb_mask_t rtlm_mask = c->plan->rtlm_mask;
+
+    for (unsigned int i = 0; i < count; i++) {
+      hb_codepoint_t codepoint = unicode->mirroring (info[i].codepoint);
+      if (unlikely (codepoint != info[i].codepoint && c->font->has_glyph (codepoint)))
+	info[i].codepoint = codepoint;
+      else
+	info[i].mask |= rtlm_mask;
+    }
+  }
+
+#ifndef HB_NO_VERTICAL
+  if (HB_DIRECTION_IS_VERTICAL (c->target_direction) && !c->plan->has_vert)
+  {
+    for (unsigned int i = 0; i < count; i++) {
+      hb_codepoint_t codepoint = hb_vert_char_for (info[i].codepoint);
+      if (unlikely (codepoint != info[i].codepoint && c->font->has_glyph (codepoint)))
+	info[i].codepoint = codepoint;
+    }
   }
+#endif
 }
 
 static inline void
@@ -655,6 +765,14 @@ hb_ot_shape_setup_masks_fraction (const hb_ot_shape_context_t *c)
 	     _hb_glyph_info_get_general_category (&info[end]) ==
 	     HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
 	end++;
+      if (start == i || end == i + 1)
+      {
+        if (start == i)
+	  buffer->unsafe_to_concat (start, start + 1);
+	if (end == i + 1)
+	  buffer->unsafe_to_concat (end - 1, end);
+	continue;
+      }
 
       buffer->unsafe_to_break (start, end);
 
@@ -693,7 +811,7 @@ hb_ot_shape_setup_masks (const hb_ot_shape_context_t *c)
   for (unsigned int i = 0; i < c->num_user_features; i++)
   {
     const hb_feature_t *feature = &c->user_features[i];
-    if (!(feature->start == 0 && feature->end == (unsigned int)-1)) {
+    if (!(feature->start == HB_FEATURE_GLOBAL_START && feature->end == HB_FEATURE_GLOBAL_END)) {
       unsigned int shift;
       hb_mask_t mask = map->get_mask (feature->tag, &shift);
       buffer->set_masks (feature->value << shift, mask, feature->start, feature->end);
@@ -741,7 +859,7 @@ hb_ot_hide_default_ignorables (hb_buffer_t *buffer,
     }
   }
   else
-    hb_ot_layout_delete_glyphs_inplace (buffer, _hb_glyph_info_is_default_ignorable);
+    buffer->delete_glyphs_inplace (_hb_glyph_info_is_default_ignorable);
 }
 
 
@@ -788,7 +906,7 @@ hb_ot_substitute_default (const hb_ot_shape_context_t *c)
 {
   hb_buffer_t *buffer = c->buffer;
 
-  hb_ot_mirror_chars (c);
+  hb_ot_rotate_chars (c);
 
   HB_BUFFER_ALLOCATE_VAR (buffer, glyph_index);
 
@@ -806,7 +924,7 @@ hb_ot_substitute_default (const hb_ot_shape_context_t *c)
 }
 
 static inline void
-hb_ot_substitute_complex (const hb_ot_shape_context_t *c)
+hb_ot_substitute_plan (const hb_ot_shape_context_t *c)
 {
   hb_buffer_t *buffer = c->buffer;
 
@@ -815,7 +933,13 @@ hb_ot_substitute_complex (const hb_ot_shape_context_t *c)
   if (c->plan->fallback_glyph_classes)
     hb_synthesize_glyph_classes (c->buffer);
 
-  c->plan->substitute (c->font, buffer);
+#ifndef HB_NO_AAT_SHAPE
+  if (unlikely (c->plan->apply_morx))
+    hb_aat_layout_substitute (c->plan, c->font, c->buffer,
+			      c->user_features, c->num_user_features);
+  else
+#endif
+    c->plan->substitute (c->font, buffer);
 }
 
 static inline void
@@ -825,20 +949,29 @@ hb_ot_substitute_pre (const hb_ot_shape_context_t *c)
 
   _hb_buffer_allocate_gsubgpos_vars (c->buffer);
 
-  hb_ot_substitute_complex (c);
+  hb_ot_substitute_plan (c);
+
+#ifndef HB_NO_AAT_SHAPE
+  if (c->plan->apply_morx && c->plan->apply_gpos)
+    hb_aat_layout_remove_deleted_glyphs (c->buffer);
+#endif
 }
 
 static inline void
 hb_ot_substitute_post (const hb_ot_shape_context_t *c)
 {
-  hb_ot_hide_default_ignorables (c->buffer, c->font);
 #ifndef HB_NO_AAT_SHAPE
-  if (c->plan->apply_morx)
+  if (c->plan->apply_morx && !c->plan->apply_gpos)
     hb_aat_layout_remove_deleted_glyphs (c->buffer);
 #endif
 
-  if (c->plan->shaper->postprocess_glyphs)
+  hb_ot_hide_default_ignorables (c->buffer, c->font);
+
+  if (c->plan->shaper->postprocess_glyphs &&
+    c->buffer->message(c->font, "start postprocess-glyphs")) {
     c->plan->shaper->postprocess_glyphs (c->plan, c->buffer, c->font);
+    (void) c->buffer->message(c->font, "end postprocess-glyphs");
+  }
 }
 
 
@@ -909,7 +1042,7 @@ hb_ot_position_default (const hb_ot_shape_context_t *c)
 }
 
 static inline void
-hb_ot_position_complex (const hb_ot_shape_context_t *c)
+hb_ot_position_plan (const hb_ot_shape_context_t *c)
 {
   unsigned int count = c->buffer->len;
   hb_glyph_info_t *info = c->buffer->info;
@@ -921,8 +1054,8 @@ hb_ot_position_complex (const hb_ot_shape_context_t *c)
    * direction is backward we don't shift and it will end up
    * hanging over the next glyph after the final reordering.
    *
-   * Note: If fallback positinoing happens, we don't care about
-   * this as it will be overriden.
+   * Note: If fallback positioning happens, we don't care about
+   * this as it will be overridden.
    */
   bool adjust_offsets_when_zeroing = c->plan->adjust_mark_positioning_when_zeroing &&
 				     HB_DIRECTION_IS_FORWARD (c->buffer->props.direction);
@@ -994,7 +1127,7 @@ hb_ot_position (const hb_ot_shape_context_t *c)
 
   hb_ot_position_default (c);
 
-  hb_ot_position_complex (c);
+  hb_ot_position_plan (c);
 
   if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction))
     hb_buffer_reverse (c->buffer);
@@ -1008,23 +1141,42 @@ hb_propagate_flags (hb_buffer_t *buffer)
   /* Propagate cluster-level glyph flags to be the same on all cluster glyphs.
    * Simplifies using them. */
 
-  if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_UNSAFE_TO_BREAK))
+  if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_GLYPH_FLAGS))
     return;
 
+  /* If we are producing SAFE_TO_INSERT_TATWEEL, then do two things:
+   *
+   * - If the places that the Arabic shaper marked as SAFE_TO_INSERT_TATWEEL,
+   *   are UNSAFE_TO_BREAK, then clear the SAFE_TO_INSERT_TATWEEL,
+   * - Any place that is SAFE_TO_INSERT_TATWEEL, is also now UNSAFE_TO_BREAK.
+   *
+   * We couldn't make this interaction earlier. It has to be done here.
+   */
+  bool flip_tatweel = buffer->flags & HB_BUFFER_FLAG_PRODUCE_SAFE_TO_INSERT_TATWEEL;
+
+  bool clear_concat = (buffer->flags & HB_BUFFER_FLAG_PRODUCE_UNSAFE_TO_CONCAT) == 0;
+
   hb_glyph_info_t *info = buffer->info;
 
   foreach_cluster (buffer, start, end)
   {
     unsigned int mask = 0;
     for (unsigned int i = start; i < end; i++)
-      if (info[i].mask & HB_GLYPH_FLAG_UNSAFE_TO_BREAK)
-      {
-	 mask = HB_GLYPH_FLAG_UNSAFE_TO_BREAK;
-	 break;
-      }
-    if (mask)
-      for (unsigned int i = start; i < end; i++)
-	info[i].mask |= mask;
+      mask |= info[i].mask & HB_GLYPH_FLAG_DEFINED;
+
+    if (flip_tatweel)
+    {
+      if (mask & HB_GLYPH_FLAG_UNSAFE_TO_BREAK)
+	mask &= ~HB_GLYPH_FLAG_SAFE_TO_INSERT_TATWEEL;
+      if (mask & HB_GLYPH_FLAG_SAFE_TO_INSERT_TATWEEL)
+	mask |= HB_GLYPH_FLAG_UNSAFE_TO_BREAK | HB_GLYPH_FLAG_UNSAFE_TO_CONCAT;
+    }
+
+    if (clear_concat)
+	mask &= ~HB_GLYPH_FLAG_UNSAFE_TO_CONCAT;
+
+    for (unsigned int i = start; i < end; i++)
+      info[i].mask = mask;
   }
 }
 
@@ -1033,26 +1185,11 @@ hb_propagate_flags (hb_buffer_t *buffer)
 static void
 hb_ot_shape_internal (hb_ot_shape_context_t *c)
 {
-  c->buffer->deallocate_var_all ();
-  c->buffer->scratch_flags = HB_BUFFER_SCRATCH_FLAG_DEFAULT;
-  if (likely (!hb_unsigned_mul_overflows (c->buffer->len, HB_BUFFER_MAX_LEN_FACTOR)))
-  {
-    c->buffer->max_len = hb_max (c->buffer->len * HB_BUFFER_MAX_LEN_FACTOR,
-			      (unsigned) HB_BUFFER_MAX_LEN_MIN);
-  }
-  if (likely (!hb_unsigned_mul_overflows (c->buffer->len, HB_BUFFER_MAX_OPS_FACTOR)))
-  {
-    c->buffer->max_ops = hb_max (c->buffer->len * HB_BUFFER_MAX_OPS_FACTOR,
-			      (unsigned) HB_BUFFER_MAX_OPS_MIN);
-  }
-
   /* Save the original direction, we use it later. */
   c->target_direction = c->buffer->props.direction;
 
   _hb_buffer_allocate_unicode_vars (c->buffer);
 
-  c->buffer->clear_output ();
-
   hb_ot_shape_initialize_masks (c);
   hb_set_unicode_props (c->buffer);
   hb_insert_dotted_circle (c->buffer, c->font);
@@ -1061,8 +1198,12 @@ hb_ot_shape_internal (hb_ot_shape_context_t *c)
 
   hb_ensure_native_direction (c->buffer);
 
-  if (c->plan->shaper->preprocess_text)
+  if (c->plan->shaper->preprocess_text &&
+      c->buffer->message(c->font, "start preprocess-text"))
+  {
     c->plan->shaper->preprocess_text (c->plan, c->buffer, c->font);
+    (void) c->buffer->message(c->font, "end preprocess-text");
+  }
 
   hb_ot_substitute_pre (c);
   hb_ot_position (c);
@@ -1074,9 +1215,7 @@ hb_ot_shape_internal (hb_ot_shape_context_t *c)
 
   c->buffer->props.direction = c->target_direction;
 
-  c->buffer->max_len = HB_BUFFER_MAX_LEN_DEFAULT;
-  c->buffer->max_ops = HB_BUFFER_MAX_OPS_DEFAULT;
-  c->buffer->deallocate_var_all ();
+  c->buffer->leave ();
 }
 
 
@@ -1096,6 +1235,12 @@ _hb_ot_shape (hb_shape_plan_t    *shape_plan,
 
 /**
  * hb_ot_shape_plan_collect_lookups:
+ * @shape_plan: #hb_shape_plan_t to query
+ * @table_tag: GSUB or GPOS
+ * @lookup_indexes: (out): The #hb_set_t set of lookups returned
+ *
+ * Computes the complete set of GSUB or GPOS lookups that are applicable
+ * under a given @shape_plan.
  *
  * Since: 0.9.7
  **/
@@ -1130,6 +1275,15 @@ add_char (hb_font_t          *font,
 
 /**
  * hb_ot_shape_glyphs_closure:
+ * @font: #hb_font_t to work upon
+ * @buffer: The input buffer to compute from
+ * @features: (array length=num_features): The features enabled on the buffer
+ * @num_features: The number of features enabled on the buffer
+ * @glyphs: (out): The #hb_set_t set of glyphs comprising the transitive closure of the query
+ *
+ * Computes the transitive closure of glyphs needed for a specified
+ * input buffer under the given font and feature list. The closure is
+ * computed as a set, not as a list.
  *
  * Since: 0.9.2
  **/