Fix incorrect style recalculation of text-decoration properties.

Source/core/rendering/style/RenderStyle.cpp

 /*
  * Copyright (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2011 Adobe Systems Incorporated. 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.
  *
@@ skipping 1306 matching lines @@
     }
 
     list->append(decoration);
 }
 
 void RenderStyle::applyTextDecorations()
 {
     if (textDecoration() == TextDecorationNone)
         return;
 
+    TextDecorationStyle style = textDecorationStyle();
+    StyleColor styleColor = visitedDependentDecorationStyleColor();
+
     int decorations = textDecoration();
 
     if (decorations & TextDecorationUnderline) {
         // To save memory, we don't use AppliedTextDecoration objects in the
-        // common case of a single underline.
-        if (!rareInheritedData->appliedTextDecorations)
+        // common case of a single simple underline.
+        AppliedTextDecoration underline(TextDecorationUnderline, style, styleColor);
+
+        if (!rareInheritedData->appliedTextDecorations && underline.isSimple())
             inherited_flags.m_textUnderline = true;
         else
-            addAppliedTextDecoration(AppliedTextDecoration(TextDecorationUnderline));
+            addAppliedTextDecoration(underline);
     }
     if (decorations & TextDecorationOverline)
-        addAppliedTextDecoration(AppliedTextDecoration(TextDecorationOverline));
+        addAppliedTextDecoration(AppliedTextDecoration(TextDecorationOverline, style, styleColor));
     if (decorations & TextDecorationLineThrough)
-        addAppliedTextDecoration(AppliedTextDecoration(TextDecorationLineThrough));
+        addAppliedTextDecoration(AppliedTextDecoration(TextDecorationLineThrough, style, styleColor));
 }
 
 void RenderStyle::clearAppliedTextDecorations()
 {
     inherited_flags.m_textUnderline = false;
 
     if (rareInheritedData->appliedTextDecorations)
         rareInheritedData.access()->appliedTextDecorations = nullptr;
 }
 
@@ skipping 67 matching lines @@
         const ShadowData& shadow = shadowList->shadows()[i];
         if (shadow.style() == Inset)
             continue;
         float blurAndSpread = shadow.blur() + shadow.spread();
 
         top = min<LayoutUnit>(top, shadow.y() - blurAndSpread);
         bottom = max<LayoutUnit>(bottom, shadow.y() + blurAndSpread);
     }
 }
 
-StyleColor RenderStyle::visitedDependentDecorationColor() const
+StyleColor RenderStyle::visitedDependentDecorationStyleColor() const
 {
-    // Text decoration color fallback is handled in RenderObject::decorationColor.
-    return insideLink() == InsideVisitedLink ? visitedLinkTextDecorationColor() : textDecorationColor();
+    bool isVisited = insideLink() == InsideVisitedLink;
+
+    StyleColor styleColor = isVisited ? visitedLinkTextDecorationColor() : textDecorationColor();
+
+    if (!styleColor.isCurrentColor())

[Julien - ping for review, 2014/05/19 10:30:18]

Shouldn't we also make sure that |styleColor| is not fully transparent here too?

[andersr, 2014/05/19 12:54:02]

Hmm, I don't think so, because then we would fall back to
strokeColor/fillColor/currentColor even when the author explicitly sets
'text-decoration-color: transparent'.

+        return styleColor;
+
+    if (textStrokeWidth()) {
+        // Prefer stroke color if possible, but not if it's fully transparent.
+        StyleColor textStrokeStyleColor = isVisited ? visitedLinkTextStrokeColor() : textStrokeColor();
+        if (!textStrokeStyleColor.isCurrentColor() && textStrokeStyleColor.color().alpha())
+            return textStrokeStyleColor;
+    }
+
+    return isVisited ? visitedLinkTextFillColor() : textFillColor();
+}
+
+Color RenderStyle::visitedDependentDecorationColor() const
+{
+    bool isVisited = insideLink() == InsideVisitedLink;
+    return visitedDependentDecorationStyleColor().resolve(isVisited ? visitedLinkColor() : color());
 }
 
 Color RenderStyle::colorIncludingFallback(int colorProperty, bool visitedLink) const
 {
     StyleColor result(StyleColor::currentColor());
     EBorderStyle borderStyle = BNONE;
     switch (colorProperty) {
     case CSSPropertyBackgroundColor:
         result = visitedLink ? visitedLinkBackgroundColor() : backgroundColor();
         break;
@@ skipping 279 matching lines @@
     // right
     radiiSum = radii.topRight().height() + radii.bottomRight().height();
     if (radiiSum > rect.height())
         factor = std::min(rect.height() / radiiSum, factor);
 
     ASSERT(factor <= 1);
     return factor;
 }
 
 } // namespace WebCore