Check for Unicode in Font before ICU call

Source/platform/fonts/shaping/HarfBuzzShaper.cpp

 /*
  * Copyright (c) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 BlackBerry Limited. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 341 matching lines @@
     bool error = false;
     const UChar* source;
     String stringFor8BitRun;
     if (run.is8Bit()) {
         stringFor8BitRun = String::make16BitFrom8BitSource(run.characters8(), run.length());
         source = stringFor8BitRun.characters16();
     } else {
         source = run.characters16();
     }
 
+    // Convert to NFC form if the text has diacritical marks.
+    icu::UnicodeString normalizedString;
+    UErrorCode errorICU = U_ZERO_ERROR;
+
+    for (unsigned i = 0; i < (unsigned)run.length(); ++i) {

[eae, 2015/02/10 15:40:12]

Here and elsewhere, use static_cast instead of C-style casts.

[h.joshi, 2015/02/17 03:44:47]

Done.

+        UChar ch = source[i];

[eae, 2015/02/10 15:40:12]

Only used once, no need for local variable.

[h.joshi, 2015/02/17 03:44:47]

Done.

+        if (::ublock_getCode(ch) == UBLOCK_COMBINING_DIACRITICAL_MARKS) {
+            icu::Normalizer::normalize(icu::UnicodeString(source,
+                run.length()), UNORM_NFC, 0 /* no options */,
+                normalizedString, errorICU);
+            if (U_FAILURE(errorICU))
+                normalizedString.remove();
+            break;
+        }
+    }
+
+    if (normalizedString.isEmpty()) {
+        length = (unsigned)run.length();
+    } else {
+        length = (unsigned)normalizedString.length();
+        source = normalizedString.getBuffer();
+    }
+
     *destinationLength = 0;
     while (position < length) {
         UChar32 character;
         U16_NEXT(source, position, length, character);
         // Don't normalize tabs as they are not treated as spaces for word-end.
         if (run.normalizeSpace() && Character::isNormalizedCanvasSpaceCharacter(character))
             character = space;
         else if (Character::treatAsSpace(character) && character != characterTabulation)
             character = space;
         else if (Character::treatAsZeroWidthSpaceInComplexScript(character))
@@ skipping 185 matching lines @@
 }
 
 static inline int handleMultipleUChar(
     UChar32 character,
     unsigned clusterLength,
     const SimpleFontData* currentFontData,
     const UChar* currentCharacterPosition,
     const UChar* markCharactersEnd,
     const UChar* normalizedBufferEnd)
 {
+    ASSERT(currentFontData);
     if (U_GET_GC_MASK(character) & U_GC_M_MASK) {
+        /* If current font does not have Unicode, we should not go further.
+            Blink will fallback to some other font to display this Unicode.
+        */
+        if (!currentFontData->fontHasGlyphForCharacter(character))
+            return 0;
+
         int markLength = clusterLength;
         while (markCharactersEnd < normalizedBufferEnd) {
             UChar32 nextCharacter;
             int nextCharacterLength = 0;
             U16_NEXT(markCharactersEnd, nextCharacterLength, normalizedBufferEnd - markCharactersEnd, nextCharacter);
+            if (!currentFontData->fontHasGlyphForCharacter(nextCharacter))
+                return 0;
             if (!(U_GET_GC_MASK(nextCharacter) & U_GC_M_MASK))
                 break;
             markLength += nextCharacterLength;
             markCharactersEnd += nextCharacterLength;
         }
 
         if (currentFontData->canRenderCombiningCharacterSequence(currentCharacterPosition, markCharactersEnd - currentCharacterPosition)) {
             return markLength;
         }
     }
@@ skipping 617 matching lines @@
     // possibly invalid from, to arguments.
     if (!foundToX && !foundFromX)
         fromX = toX = 0;
 
     if (fromX < toX)
         return FloatRect(point.x() + fromX, point.y(), toX - fromX, height);
     return FloatRect(point.x() + toX, point.y(), fromX - toX, height);
 }
 
 } // namespace blink