Roll HarfBuzz to 1.4.1

third_party/harfbuzz-ng/src/hb-ot-shape-complex-use.cc

 /*
  * Copyright © 2015  Mozilla Foundation.
  * Copyright © 2015  Google, Inc.
  *
  *  This is part of HarfBuzz, a text shaping library.
  *
  * Permission is hereby granted, without written agreement and without
  * license or royalty fees, to use, copy, modify, and distribute this
  * software and its documentation for any purpose, provided that the
  * above copyright notice and the following two paragraphs appear in
@@ skipping 541 matching lines @@
 
   /* Zero syllables now... */
   unsigned int count = buffer->len;
   for (unsigned int i = 0; i < count; i++)
     info[i].syllable() = 0;
 
   HB_BUFFER_DEALLOCATE_VAR (buffer, use_category);
 }
 
 static bool
+decompose_use (const hb_ot_shape_normalize_context_t *c,
+                hb_codepoint_t  ab,
+                hb_codepoint_t *a,
+                hb_codepoint_t *b)
+{
+  switch (ab)
+  {
+    /* Chakma:
+     * Special case where the Unicode decomp gives matras in the wrong order
+     * for cluster validation.
+     */
+    case 0x1112Eu : *a = 0x11127u; *b= 0x11131u; return true;
+    case 0x1112Fu : *a = 0x11127u; *b= 0x11132u; return true;
+
+    /*
+     * Decompose split matras that don't have Unicode decompositions.
+     */
+
+    /* Limbu */
+    case 0x1925u  : *a = 0x1920u; *b= 0x1923u; return true;
+    case 0x1926u  : *a = 0x1920u; *b= 0x1924u; return true;
+
+    /* Balinese */
+    case 0x1B3Cu  : *a = 0x1B42u; *b= 0x1B3Cu; return true;
+
+#if 0
+    /* Lepcha */
+    case 0x1C29u  : *a = no decomp, -> LEFT; return true;
+
+    /* Javanese */
+    case 0xA9C0u  : *a = no decomp, -> RIGHT; return true;
+
+    /* Sharada */
+    case 0x111BFu  : *a = no decomp, -> ABOVE; return true;
+#endif
+  }
+
+  return (bool) c->unicode->decompose (ab, a, b);
+}
+
+static bool
 compose_use (const hb_ot_shape_normalize_context_t *c,
              hb_codepoint_t  a,
              hb_codepoint_t  b,
              hb_codepoint_t *ab)
 {
   /* Avoid recomposing split matras. */
   if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (c->unicode->general_category (a)))
     return false;
 
   return (bool)c->unicode->compose (a, b, ab);
 }
 
 
 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_use =
 {
   "use",
   collect_features_use,
   NULL, /* override_features */
   data_create_use,
   data_destroy_use,
   NULL, /* preprocess_text */
   NULL, /* postprocess_glyphs */
   HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT,
-  NULL, /* decompose */
+  decompose_use,
   compose_use,
   setup_masks_use,
+  NULL, /* disable_otl */
   HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY,
   false, /* fallback_position */
 };