Fix handling of word-spacing and nbsp for complex text

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 584 matching lines @@
         source = run.characters16();
     }
 
     *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 = spaceCharacter;
-        else if (Character::treatAsSpace(character))
+        else if (Character::treatAsSpace(character) && character != noBreakSpaceCharacter)
             character = spaceCharacter;
         else if (Character::treatAsZeroWidthSpaceInComplexScript(character))
             character = zeroWidthSpaceCharacter;
 
         U16_APPEND(destination, *destinationLength, length, character, error);
         ASSERT_UNUSED(error, !error);
     }
 }
 
 HarfBuzzShaper::HarfBuzzShaper(const Font* font, const TextRun& run)
@@ skipping 549 matching lines @@
 }
 
 float HarfBuzzShaper::adjustSpacing(ShapeResult::RunInfo* run, size_t glyphIndex, unsigned currentCharacterIndex, float& offset, float& totalAdvance)
 {
     float spacing = 0;
     UChar32 character = m_normalizedBuffer[currentCharacterIndex];
     if (m_letterSpacing && !Character::treatAsZeroWidthSpace(character))
         spacing += m_letterSpacing;
 
     bool treatAsSpace = Character::treatAsSpace(character);
-    if (treatAsSpace && currentCharacterIndex && (character != '\t' || !m_textRun.allowTabs()))
+    if (treatAsSpace && (currentCharacterIndex || character == noBreakSpaceCharacter) && (character != '\t' || !m_textRun.allowTabs()))

[pdr., 2015/08/22 02:29:46]

This change took me a while to understand, but I'm not sure a comment would even
help :/

         spacing += m_wordSpacingAdjustment;
 
     if (!m_expansionOpportunityCount)
         return spacing;
 
     if (treatAsSpace) {
         spacing += nextExpansionPerOpportunity();
         m_isAfterExpansion = true;
         return spacing;
     }
@@ skipping 28 matching lines @@
             return spacing;
     }
 
     // Don't need to check m_textRun.allowsTrailingExpansion() since it's covered by !m_expansionOpportunityCount above
     spacing += nextExpansionPerOpportunity();
     m_isAfterExpansion = true;
     return spacing;
 }
 
 } // namespace blink