Merge 122883 - vertical-align: middle causes overflow with subpixel layout

Source/WebCore/rendering/RootInlineBox.cpp

 /*
  * Copyright (C) 2003, 2006, 2008 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 850 matching lines @@
 
         LineDirectionMode lineDirection = parent->isHorizontalWritingMode() ? HorizontalLine : VerticalLine;
 
         if (verticalAlign == SUB)
             verticalPosition += fontSize / 5 + 1;
         else if (verticalAlign == SUPER)
             verticalPosition -= fontSize / 3 + 1;
         else if (verticalAlign == TEXT_TOP)
             verticalPosition += renderer->baselinePosition(baselineType(), firstLine, lineDirection) - fontMetrics.ascent(baselineType());
         else if (verticalAlign == MIDDLE)
-            verticalPosition += -static_cast<int>(fontMetrics.xHeight() / 2) - renderer->lineHeight(firstLine, lineDirection) / 2 + renderer->baselinePosition(baselineType(), firstLine, lineDirection);
+            verticalPosition = (verticalPosition - static_cast<LayoutUnit>(fontMetrics.xHeight() / 2) - renderer->lineHeight(firstLine, lineDirection) / 2 + renderer->baselinePosition(baselineType(), firstLine, lineDirection)).round();
         else if (verticalAlign == TEXT_BOTTOM) {
             verticalPosition += fontMetrics.descent(baselineType());
             // lineHeight - baselinePosition is always 0 for replaced elements (except inline blocks), so don't bother wasting time in that case.
             if (!renderer->isReplaced() || renderer->isInlineBlockOrInlineTable())
                 verticalPosition -= (renderer->lineHeight(firstLine, lineDirection) - renderer->baselinePosition(baselineType(), firstLine, lineDirection));
         } else if (verticalAlign == BASELINE_MIDDLE)
             verticalPosition += -renderer->lineHeight(firstLine, lineDirection) / 2 + renderer->baselinePosition(baselineType(), firstLine, lineDirection);
         else if (verticalAlign == LENGTH)
             verticalPosition -= valueForLength(renderer->style()->verticalAlignLength(), renderer->lineHeight(firstLine, lineDirection), renderer->view());
     }
@@ skipping 92 matching lines @@
 }
 
 #ifndef NDEBUG
 const char* RootInlineBox::boxName() const
 {
     return "RootInlineBox";
 }
 #endif
 
 } // namespace WebCore