Fix two truncation bugs in harfbuzz-indic shaper.

third_party/harfbuzz/chromium.patch

 diff --git a/contrib/harfbuzz-unicode.c b/contrib/harfbuzz-unicode.c
 index 049e0ca..86458d0 100644
 --- a/contrib/harfbuzz-unicode.c
 +++ b/contrib/harfbuzz-unicode.c
 @@ -120,7 +120,6 @@ hb_utf16_script_run_next(unsigned *num_code_points, HB_ScriptItem *output,
          current_script = script;
          continue;
        } else if (script == HB_Script_Inherited) {
 -        current_script = script;
          continue;
@@ skipping 16 matching lines @@
 --- a/src/harfbuzz-arabic.c
 +++ b/src/harfbuzz-arabic.c
 @@ -1107,6 +1107,7 @@ HB_Bool HB_ArabicShape(HB_ShaperItem *item)
      assert(item->item.script == HB_Script_Arabic || item->item.script == HB_Script_Syriac
             || item->item.script == HB_Script_Nko);
  
 +    item->shaperFlags |= HB_ShaperFlag_ForceMarksToZeroWidth;
  #ifndef NO_OPENTYPE
  
      if (HB_SelectScript(item, item->item.script == HB_Script_Arabic ? arabic_features : syriac_features)) {
-diff --git a/src/harfbuzz-gpos.c b/src/harfbuzz-gpos.c
-index a216005..7bd3b3b 100644
---- a/src/harfbuzz-gpos.c
-+++ b/src/harfbuzz-gpos.c
-@@ -3012,6 +3012,9 @@ static HB_Error  Lookup_MarkMarkPos( GPOS_Instance*    gpi,
-     j--;
-   }
- 
-+  if ( i > buffer->in_pos )
-+    return HB_Err_Not_Covered;
-+
-   error = _HB_OPEN_Coverage_Index( &mmp->Mark2Coverage, IN_GLYPH( j ),
-                          &mark2_index );
-   if ( error )
 diff --git a/src/harfbuzz-shaper.cpp b/src/harfbuzz-shaper.cpp
 index ce4d4ac..5999e08 100644
 --- a/src/harfbuzz-shaper.cpp
 +++ b/src/harfbuzz-shaper.cpp
 @@ -430,8 +430,6 @@ void HB_HeuristicSetGlyphAttributes(HB_ShaperItem *item)
  
      // ### zeroWidth and justification are missing here!!!!!
  
 -    assert(item->num_glyphs <= length);
 -
@@ skipping 66 matching lines @@
      HB_ShaperFlag_NoKerning = 1,
 -    HB_ShaperFlag_UseDesignMetrics = 2
 +    HB_ShaperFlag_UseDesignMetrics = 1 << 1,
 +    /* Arabic vowels in some fonts (Times New Roman, at least) have
 +       non-zero advances, when they should be zero.  Setting this shaper
 +       flag causes us to zero out the advances for mark glyphs. */
 +    HB_ShaperFlag_ForceMarksToZeroWidth = 1 << 2
  } HB_ShaperFlag;
  
  /* 
-diff --git a/src/harfbuzz-tibetan.c b/src/harfbuzz-tibetan.c
-index bfa31b1..847ac52 100644
---- a/src/harfbuzz-tibetan.c
-+++ b/src/harfbuzz-tibetan.c
-@@ -90,7 +90,7 @@ static const unsigned char tibetanForm[0x80] = {
- 
- 
- #define tibetan_form(c) \
--    (TibetanForm)tibetanForm[c - 0x0f40]
-+    ((c) >= 0x0f40 && (c) <= 0x0fc0 ? (TibetanForm)tibetanForm[(c) - 0x0f40] : TibetanOther)
- 
- static const HB_OpenTypeFeature tibetan_features[] = {
-     { HB_MAKE_TAG('c', 'c', 'm', 'p'), CcmpProperty },