Explicitly set text direction for TextRuns

Source/platform/fonts/harfbuzz/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 524 matching lines @@
         m_features.append(feature);
     }
 }
 
 bool HarfBuzzShaper::shape(GlyphBuffer* glyphBuffer)
 {
     if (!collectHarfBuzzRuns())
         return false;
 
     m_totalWidth = 0;
-    // WebKit doesn't set direction when calulating widths. Leave the direction setting to
-    // HarfBuzz when we are calculating widths (except when directionalOverride() is set).
-    if (!shapeHarfBuzzRuns(glyphBuffer || m_run.directionalOverride()))
+    if (!shapeHarfBuzzRuns())
         return false;
 
     if (!RuntimeEnabledFeatures::subpixelFontScalingEnabled())
         m_totalWidth = roundf(m_totalWidth);
 
     if (glyphBuffer && !fillGlyphBuffer(glyphBuffer))
         return false;
 
     return true;
 }
@@ skipping 69 matching lines @@
 
 static const uint16_t* toUint16(const UChar* src)
 {
     // FIXME: This relies on undefined behavior however it works on the
     // current versions of all compilers we care about and avoids making
     // a copy of the string.
     COMPILE_ASSERT(sizeof(UChar) == sizeof(uint16_t), UChar_is_the_same_size_as_uint16_t);
     return reinterpret_cast<const uint16_t*>(src);
 }
 
-bool HarfBuzzShaper::shapeHarfBuzzRuns(bool shouldSetDirection)
+bool HarfBuzzShaper::shapeHarfBuzzRuns()
 {
     HarfBuzzScopedPtr<hb_buffer_t> harfBuzzBuffer(hb_buffer_create(), hb_buffer_destroy);
 
     hb_buffer_set_unicode_funcs(harfBuzzBuffer.get(), hb_icu_get_unicode_funcs());
     HarfBuzzRunCache& runCache = harfBuzzRunCache();
 
     for (unsigned i = 0; i < m_harfBuzzRuns.size(); ++i) {
         unsigned runIndex = m_run.rtl() ? m_harfBuzzRuns.size() - i - 1 : i;
         HarfBuzzRun* currentRun = m_harfBuzzRuns[runIndex].get();
         const SimpleFontData* currentFontData = currentRun->fontData();
         if (currentFontData->isSVGFont())
             return false;
 
         FontPlatformData* platformData = const_cast<FontPlatformData*>(&currentFontData->platformData());
         HarfBuzzFace* face = platformData->harfBuzzFace();
         if (!face)
             return false;
 
         hb_buffer_set_script(harfBuzzBuffer.get(), currentRun->script());
-        if (shouldSetDirection)
-            hb_buffer_set_direction(harfBuzzBuffer.get(), currentRun->rtl() ? HB_DIRECTION_RTL : HB_DIRECTION_LTR);
-        else
-            // Leaving direction to HarfBuzz to guess is *really* bad, but will do for now.
-            hb_buffer_guess_segment_properties(harfBuzzBuffer.get());
+        hb_buffer_set_direction(harfBuzzBuffer.get(), currentRun->rtl() ? HB_DIRECTION_RTL : HB_DIRECTION_LTR);
 
         hb_segment_properties_t props;
         hb_buffer_get_segment_properties(harfBuzzBuffer.get(), &props);
 
         const UChar* src = m_normalizedBuffer.get() + currentRun->startIndex();
         std::wstring key(src, src + currentRun->numCharacters());
 
         CachedShapingResults* cachedResults = runCache.find(key);
         if (cachedResults) {
             if (cachedResults->dir == props.direction && cachedResults->font == *m_font) {
@@ skipping 214 matching lines @@
     if (!foundToX)
         toX = m_run.rtl() ? 0 : m_totalWidth;
 
     // Using floorf() and roundf() as the same as mac port.
     if (fromX < toX)
         return FloatRect(floorf(point.x() + fromX), point.y(), roundf(toX - fromX), height);
     return FloatRect(floorf(point.x() + toX), point.y(), roundf(fromX - toX), height);
 }
 
 } // namespace WebCore