Zero marks by GDEF for Tibetan

See:
http://lists.freedesktop.org/archives/harfbuzz/2013-April/003101.html

src/hb-ot-layout-gsubgpos-private.hh

@@ -616,8 +616,8 @@ struct hb_apply_context_t
   }
 
   inline void _set_glyph_props (hb_codepoint_t glyph_index,
-			  unsigned int class_guess = 0,
-			  bool ligature = false) const
+				unsigned int class_guess = 0,
+				bool ligature = false) const
   {
     unsigned int add_in = _hb_glyph_info_get_glyph_props (&buffer->cur()) &
 			  HB_OT_LAYOUT_GLYPH_PROPS_PRESERVE;

src/hb-ot-shape-complex-arabic.cc

@@ -177,8 +177,6 @@ collect_features_arabic (hb_ot_shape_planner_t *plan)
    *
    * This also makes Arial Bold in Windows7 work.  See:
    * https://bugzilla.mozilla.org/show_bug.cgi?id=644184
-   *
-   * TODO: Add test cases for these two.
    */
 
   map->add_gsub_pause (nuke_joiners);
@@ -357,6 +355,12 @@ retry:
   arabic_fallback_plan_shape (fallback_plan, font, buffer);
 }
 
+static hb_ot_shape_zero_width_marks_t
+zero_width_marks_preference_arabic (const hb_segment_properties_t *props HB_UNUSED)
+{
+  return HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE;
+}
+
 
 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_arabic =
 {
@@ -370,6 +374,6 @@ const hb_ot_complex_shaper_t _hb_ot_complex_shaper_arabic =
   NULL, /* decompose */
   NULL, /* compose */
   setup_masks_arabic,
-  HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE,
+  zero_width_marks_preference_arabic,
   true, /* fallback_position */
 };

src/hb-ot-shape-complex-default.cc

@@ -203,6 +203,21 @@ compose_default (const hb_ot_shape_normalize_context_t *c,
   return found;
 }
 
+static hb_ot_shape_zero_width_marks_t
+zero_width_marks_preference_default (const hb_segment_properties_t *props)
+{
+  switch ((hb_tag_t) props->script)
+  {
+    /* Unicode-2.0 additions */
+    case HB_SCRIPT_TIBETAN:
+      return HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE;
+
+    default:
+      return HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE;
+  }
+}
+
+
 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_default =
 {
   "default",
@@ -215,6 +230,6 @@ const hb_ot_complex_shaper_t _hb_ot_complex_shaper_default =
   NULL, /* decompose */
   compose_default,
   NULL, /* setup_masks */
-  HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE,
+  zero_width_marks_preference_default,
   true, /* fallback_position */
 };

src/hb-ot-shape-complex-indic.cc

@@ -1791,6 +1791,12 @@ compose_indic (const hb_ot_shape_normalize_context_t *c,
   return c->unicode->compose (a, b, ab);
 }
 
+static hb_ot_shape_zero_width_marks_t
+zero_width_marks_preference_indic (const hb_segment_properties_t *props HB_UNUSED)
+{
+  return HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE;
+}
+
 
 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_indic =
 {
@@ -1804,6 +1810,6 @@ const hb_ot_complex_shaper_t _hb_ot_complex_shaper_indic =
   decompose_indic,
   compose_indic,
   setup_masks_indic,
-  HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE,
+  zero_width_marks_preference_indic,
   false, /* fallback_position */
 };

src/hb-ot-shape-complex-myanmar.cc

@@ -263,6 +263,12 @@ set_myanmar_properties (hb_glyph_info_t &info)
 
 
 
+static hb_ot_shape_normalization_mode_t
+normalization_preference_myanmar (const hb_segment_properties_t *props HB_UNUSED)
+{
+  return HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT;
+}
+
 static void
 setup_masks_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
 		   hb_buffer_t              *buffer,
@@ -519,11 +525,10 @@ final_reordering (const hb_ot_shape_plan_t *plan,
   HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_position);
 }
 
-
-static hb_ot_shape_normalization_mode_t
-normalization_preference_myanmar (const hb_segment_properties_t *props HB_UNUSED)
+static hb_ot_shape_zero_width_marks_t
+zero_width_marks_preference_myanmar (const hb_segment_properties_t *props HB_UNUSED)
 {
-  return HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT;
+  return HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY;
 }
 
 
@@ -539,6 +544,6 @@ const hb_ot_complex_shaper_t _hb_ot_complex_shaper_myanmar =
   NULL, /* decompose */
   NULL, /* compose */
   setup_masks_myanmar,
-  HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY,
+  zero_width_marks_preference_myanmar,
   false, /* fallback_position */
 };

src/hb-ot-shape-complex-private.hh

@@ -39,7 +39,7 @@
 #define complex_var_u8_1()	var2.u8[3]
 
 
-enum hb_ot_shape_zero_width_marks_type_t {
+enum hb_ot_shape_zero_width_marks_t {
   HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE,
 //  HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_EARLY,
   HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE,
@@ -140,7 +140,11 @@ struct hb_ot_complex_shaper_t
 		       hb_buffer_t              *buffer,
 		       hb_font_t                *font);
 
-  hb_ot_shape_zero_width_marks_type_t zero_width_marks;
+  /* zero_width_marks_preference()
+   * Called during shape().
+   */
+  hb_ot_shape_zero_width_marks_t
+  (*zero_width_marks_preference) (const hb_segment_properties_t *props);
 
   bool fallback_position;
 };

src/hb-ot-shape-complex-sea.cc

@@ -162,6 +162,12 @@ set_sea_properties (hb_glyph_info_t &info)
 }
 
 
+static hb_ot_shape_normalization_mode_t
+normalization_preference_sea (const hb_segment_properties_t *props HB_UNUSED)
+{
+  return HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT;
+}
+
 static void
 setup_masks_sea (const hb_ot_shape_plan_t *plan HB_UNUSED,
 		 hb_buffer_t              *buffer,
@@ -360,10 +366,10 @@ final_reordering (const hb_ot_shape_plan_t *plan,
 }
 
 
-static hb_ot_shape_normalization_mode_t
-normalization_preference_sea (const hb_segment_properties_t *props HB_UNUSED)
+static hb_ot_shape_zero_width_marks_t
+zero_width_marks_preference_sea (const hb_segment_properties_t *props HB_UNUSED)
 {
-  return HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT;
+  return HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE;
 }
 
 
@@ -379,6 +385,6 @@ const hb_ot_complex_shaper_t _hb_ot_complex_shaper_sea =
   NULL, /* decompose */
   NULL, /* compose */
   setup_masks_sea,
-  HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE,
+  zero_width_marks_preference_sea,
   false, /* fallback_position */
 };

src/hb-ot-shape-complex-thai.cc

@@ -361,6 +361,13 @@ preprocess_text_thai (const hb_ot_shape_plan_t *plan,
     do_thai_pua_shaping (plan, buffer, font);
 }
 
+static hb_ot_shape_zero_width_marks_t
+zero_width_marks_preference_thai (const hb_segment_properties_t *props HB_UNUSED)
+{
+  return HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE;
+}
+
+
 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_thai =
 {
   "thai",
@@ -373,6 +380,6 @@ const hb_ot_complex_shaper_t _hb_ot_complex_shaper_thai =
   NULL, /* decompose */
   NULL, /* compose */
   NULL, /* setup_masks */
-  HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE,
+  zero_width_marks_preference_thai,
   false,/* fallback_position */
 };

src/hb-ot-shape.cc

@@ -441,7 +441,7 @@ hb_ot_position_complex (hb_ot_shape_context_t *c)
   bool ret = false;
   unsigned int count = c->buffer->len;
 
-  switch (c->plan->shaper->zero_width_marks)
+  switch (c->plan->shaper->zero_width_marks_preference (&c->plan->props))
   {
     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY:
       zero_mark_widths_by_gdef (c->buffer);
@@ -483,7 +483,7 @@ hb_ot_position_complex (hb_ot_shape_context_t *c)
     ret = true;
   }
 
-  switch (c->plan->shaper->zero_width_marks)
+  switch (c->plan->shaper->zero_width_marks_preference (&c->plan->props))
   {
     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE:
       zero_mark_widths_by_unicode (c->buffer);