linux: hack around arabic advances in harfbuzz

third_party/harfbuzz/src/harfbuzz-arabic.c

 /*
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  *
  * This is part of HarfBuzz, an OpenType Layout engine 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
  * all copies of this software.
@@ skipping 1089 matching lines @@
 /* #### stil missing: identify invalid character combinations */
 HB_Bool HB_ArabicShape(HB_ShaperItem *item)
 {
     int slen;
     HB_Bool haveGlyphs;
     HB_STACKARRAY(HB_UChar16, shapedChars, item->item.length);
 
     assert(item->item.script == HB_Script_Arabic || item->item.script == HB_Script_Syriac
            || item->item.script == HB_Script_Nko);
 
+    item->shaperFlags |= HB_ShaperFlag_ArabicHack;

[agl, 2010/01/15 10:21:57]

Since this code is scheduled for demolition soon(ish) anyway, it's probably
moot, but I would call this ..._ForceMarksToZeroWidth or something. LGTM either
way.

 #ifndef NO_OPENTYPE
 
     if (HB_SelectScript(item, item->item.script == HB_Script_Arabic ? arabic_features : syriac_features)) {
         HB_Bool ot_ok;
         if (arabicSyriacOpenTypeShape(item, &ot_ok))
             return TRUE;
         if (ot_ok)
             return FALSE;
             /* fall through to the non OT code*/
     }
@@ skipping 15 matching lines @@
     HB_FREE_STACKARRAY(shapedChars);
 
     if (!haveGlyphs)
         return FALSE;
 
     HB_HeuristicPosition(item);
     return TRUE;
 }