commit 06cfe3f7369684fc05fa16da7f6778350f8bcba5
author Khaled Hosny <khaledhosny@eglug.org> Wed May 17 21:32:47 2017 +0300
committer Behdad Esfahbod <behdad@behdad.org> Wed May 17 11:32:47 2017 -0700
tree 833c0536a38aa09ca6fdf2155e38307810d69672
parent 1817221620dce713aae67352568ebcc231ab9512

Do not skip TAG characters in glyph substitution (#487)

Hide them like Mongolian Free Variation Selectors instead.

Fixes https://github.com/behdad/harfbuzz/issues/463

src/hb-ot-layout-private.hh

diff --git a/src/hb-ot-layout-private.hh b/src/hb-ot-layout-private.hh
index 071a439..b476339 100644
--- a/src/hb-ot-layout-private.hh
+++ b/src/hb-ot-layout-private.hh
@@ -240,7 +240,8 @@
 enum hb_unicode_props_flags_t {
   UPROPS_MASK_GEN_CAT	= 0x001Fu,
   UPROPS_MASK_IGNORABLE	= 0x0020u,
-  UPROPS_MASK_FVS	= 0x0040u, /* MONGOLIAN FREE VARIATION SELECTOR 1..3 */
+  UPROPS_MASK_HIDDEN	= 0x0040u, /* MONGOLIAN FREE VARIATION SELECTOR 1..3,
+                                    * or TAG characters */
 
   /* If GEN_CAT=FORMAT, top byte masks: */
   UPROPS_MASK_Cf_ZWJ	= 0x0100u,
@@ -273,7 +274,11 @@
        * Fixes:
        * https://github.com/behdad/harfbuzz/issues/234
        */
-      if (unlikely (hb_in_range (u, 0x180Bu, 0x180Du))) props |= UPROPS_MASK_FVS;
+      if (unlikely (hb_in_range (u, 0x180Bu, 0x180Du))) props |= UPROPS_MASK_HIDDEN;
+      /* TAG characters need similar treatment. Fixes:
+       * https://github.com/behdad/harfbuzz/issues/463
+       */
+      if (unlikely (hb_in_range (u, 0xE0020u, 0xE007Fu))) props |= UPROPS_MASK_HIDDEN;
     }
     else if (unlikely (HB_UNICODE_GENERAL_CATEGORY_IS_NON_ENCLOSING_MARK_OR_MODIFIER_SYMBOL (gen_cat)))
     {
@@ -373,9 +378,9 @@
 	 !_hb_glyph_info_ligated (info);
 }
 static inline hb_bool_t
-_hb_glyph_info_is_default_ignorable_and_not_fvs (const hb_glyph_info_t *info)
+_hb_glyph_info_is_default_ignorable_and_not_hidden (const hb_glyph_info_t *info)
 {
-  return ((info->unicode_props() & (UPROPS_MASK_IGNORABLE|UPROPS_MASK_FVS))
+  return ((info->unicode_props() & (UPROPS_MASK_IGNORABLE|UPROPS_MASK_HIDDEN))
 	  == UPROPS_MASK_IGNORABLE) &&
 	 !_hb_glyph_info_ligated (info);
 }