Roll harfbuzz-ng 3b8fd9c48f4bde368bf2d465c148b9743a9216ee

third_party/harfbuzz-ng/src/hb-unicode.cc

Index: third_party/harfbuzz-ng/src/hb-unicode.cc
diff --git a/third_party/harfbuzz-ng/src/hb-unicode.cc b/third_party/harfbuzz-ng/src/hb-unicode.cc
index 4b285c5e1ca4ae03bd55876becf98d86293787ae..f2fbebbac2f8d4f52de4f467497371acd7961ee1 100644
--- a/third_party/harfbuzz-ng/src/hb-unicode.cc
+++ b/third_party/harfbuzz-ng/src/hb-unicode.cc
@@ -85,7 +85,6 @@ hb_unicode_compose_nil (hb_unicode_funcs_t *ufuncs    HB_UNUSED,
 			hb_codepoint_t     *ab        HB_UNUSED,
 			void               *user_data HB_UNUSED)
 {
-  /* TODO handle Hangul jamo here? */
   return FALSE;
 }
 
@@ -96,7 +95,6 @@ hb_unicode_decompose_nil (hb_unicode_funcs_t *ufuncs    HB_UNUSED,
 			  hb_codepoint_t     *b         HB_UNUSED,
 			  void               *user_data HB_UNUSED)
 {
-  /* TODO handle Hangul jamo here? */
   return FALSE;
 }
 
@@ -271,3 +269,58 @@ hb_unicode_decompose (hb_unicode_funcs_t *ufuncs,
   return ufuncs->func.decompose (ufuncs, ab, a, b, ufuncs->user_data.decompose);
 }
 
+
+
+unsigned int
+_hb_unicode_modified_combining_class (hb_unicode_funcs_t *ufuncs,
+				      hb_codepoint_t      unicode)
+{
+  int c = hb_unicode_combining_class (ufuncs, unicode);
+
+  if (unlikely (hb_in_range<int> (c, 27, 33)))
+  {
+    /* Modify the combining-class to suit Arabic better.  See:
+     * http://unicode.org/faq/normalization.html#8
+     * http://unicode.org/faq/normalization.html#9
+     */
+    c = c == 33 ? 27 : c + 1;
+  }
+  else if (unlikely (hb_in_range<int> (c, 10, 25)))
+  {
+    /* The equivalent fix for Hebrew is more complex.
+     *
+     * We permute the "fixed-position" classes 10-25 into the order
+     * described in the SBL Hebrew manual:
+     *
+     * http://www.sbl-site.org/Fonts/SBLHebrewUserManual1.5x.pdf
+     *
+     * (as recommended by:
+     *  http://forum.fontlab.com/archive-old-microsoft-volt-group/vista-and-diacritic-ordering-t6751.0.html)
+     *
+     * More details here:
+     * https://bugzilla.mozilla.org/show_bug.cgi?id=662055
+     */
+    static const int permuted_hebrew_classes[25 - 10 + 1] = {
+      /* 10 sheva */        22,
+      /* 11 hataf segol */  15,
+      /* 12 hataf patah */  16,
+      /* 13 hataf qamats */ 17,
+      /* 14 hiriq */        23,
+      /* 15 tsere */        18,
+      /* 16 segol */        19,
+      /* 17 patah */        20,
+      /* 18 qamats */       21,
+      /* 19 holam */        14,
+      /* 20 qubuts */       24,
+      /* 21 dagesh */       12,
+      /* 22 meteg */        25,
+      /* 23 rafe */         13,
+      /* 24 shin dot */     10,
+      /* 25 sin dot */      11,
+    };
+    c = permuted_hebrew_classes[c - 10];
+  }
+
+  return c;
+}
+