Merge WebKit at r61871: Initial merge by git.

Change-Id: I6cff43abca9cc4782e088a469ad4f03f166a65d5

19 files changed, 146 insertions, 102 deletions

diff --git a/WebCore/mathml/MathMLElement.cpp b/WebCore/mathml/MathMLElement.cpp
index b84616f..b93ff9f 100644
--- a/WebCore/mathml/MathMLElement.cpp
+++ b/WebCore/mathml/MathMLElement.cpp
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2009 Alex Milowski (alex@milowski.com). All rights reserved.
+ * Copyright (C) 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -37,20 +38,14 @@ namespace WebCore {
 using namespace MathMLNames;
     
 MathMLElement::MathMLElement(const QualifiedName& tagName, Document* document)
-    : StyledElement(tagName, document, CreateStyledElementZeroRefCount)
+    : StyledElement(tagName, document, CreateStyledElement)
 {
 }
     
 PassRefPtr<MathMLElement> MathMLElement::create(const QualifiedName& tagName, Document* document)
 {
-    return new MathMLElement(tagName, document);
+    return adoptRef(new MathMLElement(tagName, document));
 }
-
-RenderObject* MathMLElement::createRenderer(RenderArena*, RenderStyle* style)
-{
-    return RenderObject::createObject(this, style);
-}
-    
     
 }
 
diff --git a/WebCore/mathml/MathMLElement.h b/WebCore/mathml/MathMLElement.h
index 2fa322f..46cd7fd 100644
--- a/WebCore/mathml/MathMLElement.h
+++ b/WebCore/mathml/MathMLElement.h
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2009 Alex Milowski (alex@milowski.com). All rights reserved.
+ * Copyright (C) 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -30,18 +31,16 @@
 #include "StyledElement.h"
 
 namespace WebCore {
-    
+
 class MathMLElement : public StyledElement {
 public:
     static PassRefPtr<MathMLElement> create(const QualifiedName& tagName, Document*);
-    
-    virtual bool isMathMLElement() const { return true; }
-    
-    virtual RenderObject* createRenderer(RenderArena*, RenderStyle*);
-    
+
 protected:
     MathMLElement(const QualifiedName& tagName, Document*);
-    
+
+private:    
+    virtual bool isMathMLElement() const { return true; }
 };
     
 }
diff --git a/WebCore/mathml/MathMLInlineContainerElement.cpp b/WebCore/mathml/MathMLInlineContainerElement.cpp
index c5fcac9..efc9f8c 100644
--- a/WebCore/mathml/MathMLInlineContainerElement.cpp
+++ b/WebCore/mathml/MathMLInlineContainerElement.cpp
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2009 Alex Milowski (alex@milowski.com). All rights reserved.
+ * Copyright (C) 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -32,7 +33,6 @@
 #include "MathMLNames.h"
 #include "RenderMathMLBlock.h"
 #include "RenderMathMLFraction.h"
-#include "RenderMathMLMath.h"
 #include "RenderMathMLRoot.h"
 #include "RenderMathMLRow.h"
 #include "RenderMathMLSquareRoot.h"
@@ -50,16 +50,14 @@ MathMLInlineContainerElement::MathMLInlineContainerElement(const QualifiedName&
 
 PassRefPtr<MathMLInlineContainerElement> MathMLInlineContainerElement::create(const QualifiedName& tagName, Document* document)
 {
-    return new MathMLInlineContainerElement(tagName, document);
+    return adoptRef(new MathMLInlineContainerElement(tagName, document));
 }
 
-RenderObject* MathMLInlineContainerElement::createRenderer(RenderArena *arena, RenderStyle* style)
+RenderObject* MathMLInlineContainerElement::createRenderer(RenderArena* arena, RenderStyle* style)
 {
-    RenderObject* object = 0;
+    RenderObject* object;
     if (hasLocalName(MathMLNames::mrowTag))
         object = new (arena) RenderMathMLRow(this);
-    else if (hasLocalName(MathMLNames::mathTag))
-        object = new (arena) RenderMathMLMath(this);
     else if (hasLocalName(MathMLNames::msubTag))
         object = new (arena) RenderMathMLSubSup(this);
     else if (hasLocalName(MathMLNames::msupTag))
@@ -83,9 +81,7 @@ RenderObject* MathMLInlineContainerElement::createRenderer(RenderArena *arena, R
     object->setStyle(style);
     return object;
 }
-    
-    
+
 }
 
 #endif // ENABLE(MATHML)
-
diff --git a/WebCore/mathml/MathMLInlineContainerElement.h b/WebCore/mathml/MathMLInlineContainerElement.h
index dc78dc4..4e80e36 100644
--- a/WebCore/mathml/MathMLInlineContainerElement.h
+++ b/WebCore/mathml/MathMLInlineContainerElement.h
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2009 Alex Milowski (alex@milowski.com). All rights reserved.
+ * Copyright (C) 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -35,11 +36,11 @@ class MathMLInlineContainerElement : public MathMLElement {
 public:
     static PassRefPtr<MathMLInlineContainerElement> create(const QualifiedName& tagName, Document*);
 
-    virtual RenderObject* createRenderer(RenderArena*, RenderStyle*);
-
 protected:
     MathMLInlineContainerElement(const QualifiedName& tagName, Document*);
 
+private:
+    virtual RenderObject* createRenderer(RenderArena*, RenderStyle*);
 };
     
 }
diff --git a/WebCore/mathml/MathMLMathElement.cpp b/WebCore/mathml/MathMLMathElement.cpp
index bd3b797..1b6b18d 100644
--- a/WebCore/mathml/MathMLMathElement.cpp
+++ b/WebCore/mathml/MathMLMathElement.cpp
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2009 Alex Milowski (alex@milowski.com). All rights reserved.
+ * Copyright (C) 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -29,21 +30,25 @@
 
 #include "MathMLMathElement.h"
 
-#include "MathMLNames.h"
-#include "RenderObject.h"
+#include "RenderMathMLMath.h"
 
 namespace WebCore {
-    
-using namespace MathMLNames;
 
-MathMLMathElement::MathMLMathElement(const QualifiedName& tagName, Document* document)
+inline MathMLMathElement::MathMLMathElement(const QualifiedName& tagName, Document* document)
     : MathMLInlineContainerElement(tagName, document)
 {
 }
 
 PassRefPtr<MathMLMathElement> MathMLMathElement::create(const QualifiedName& tagName, Document* document)
 {
-    return new MathMLMathElement(tagName, document);
+    return adoptRef(new MathMLMathElement(tagName, document));
+}
+
+RenderObject* MathMLMathElement::createRenderer(RenderArena* arena, RenderStyle* style)
+{
+    RenderMathMLMath* renderer = new (arena) RenderMathMLMath(this);
+    renderer->setStyle(style);
+    return renderer;
 }
 
 }
diff --git a/WebCore/mathml/MathMLMathElement.h b/WebCore/mathml/MathMLMathElement.h
index e784524..d31d548 100644
--- a/WebCore/mathml/MathMLMathElement.h
+++ b/WebCore/mathml/MathMLMathElement.h
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2009 Alex Milowski (alex@milowski.com). All rights reserved.
+ * Copyright (C) 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -30,14 +31,15 @@
 #include "MathMLInlineContainerElement.h"
 
 namespace WebCore {
-    
+
 class MathMLMathElement : public MathMLInlineContainerElement {
 public:
     static PassRefPtr<MathMLMathElement> create(const QualifiedName& tagName, Document*);
-    
-protected:
+
+private:
     MathMLMathElement(const QualifiedName& tagName, Document*);
-    
+
+    virtual RenderObject* createRenderer(RenderArena*, RenderStyle*);
 };
     
 }
diff --git a/WebCore/mathml/MathMLTextElement.cpp b/WebCore/mathml/MathMLTextElement.cpp
index 6f6bcbc..4135d6c 100644
--- a/WebCore/mathml/MathMLTextElement.cpp
+++ b/WebCore/mathml/MathMLTextElement.cpp
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2009 Alex Milowski (alex@milowski.com). All rights reserved.
+ * Copyright (C) 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -36,14 +37,14 @@ namespace WebCore {
     
 using namespace MathMLNames;
 
-MathMLTextElement::MathMLTextElement(const QualifiedName& tagName, Document* document)
+inline MathMLTextElement::MathMLTextElement(const QualifiedName& tagName, Document* document)
     : MathMLElement(tagName, document)
 {
 }
 
 PassRefPtr<MathMLTextElement> MathMLTextElement::create(const QualifiedName& tagName, Document* document)
 {
-    return new MathMLTextElement(tagName, document);
+    return adoptRef(new MathMLTextElement(tagName, document));
 }
 
 RenderObject* MathMLTextElement::createRenderer(RenderArena* arena, RenderStyle* style)
@@ -54,11 +55,9 @@ RenderObject* MathMLTextElement::createRenderer(RenderArena* arena, RenderStyle*
         return object;
     }
 
-    return RenderObject::createObject(this, style);
+    return MathMLElement::createRenderer(arena, style);
 }
 
-    
 }
 
 #endif // ENABLE(MATHML)
-
diff --git a/WebCore/mathml/MathMLTextElement.h b/WebCore/mathml/MathMLTextElement.h
index e647bfa..3af93d5 100644
--- a/WebCore/mathml/MathMLTextElement.h
+++ b/WebCore/mathml/MathMLTextElement.h
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2009 Alex Milowski (alex@milowski.com). All rights reserved.
+ * Copyright (C) 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -35,11 +36,10 @@ class MathMLTextElement : public MathMLElement {
 public:
     static PassRefPtr<MathMLTextElement> create(const QualifiedName& tagName, Document*);
 
-    virtual RenderObject* createRenderer(RenderArena*, RenderStyle*);
-    
-protected:
+private:
     MathMLTextElement(const QualifiedName& tagName, Document*);
-    
+
+    virtual RenderObject* createRenderer(RenderArena*, RenderStyle*);
 };
     
 }
diff --git a/WebCore/mathml/RenderMathMLBlock.cpp b/WebCore/mathml/RenderMathMLBlock.cpp
index a897ff5..ef94893 100644
--- a/WebCore/mathml/RenderMathMLBlock.cpp
+++ b/WebCore/mathml/RenderMathMLBlock.cpp
@@ -96,6 +96,12 @@ void RenderMathMLBlock::paint(PaintInfo& info, int tx, int ty)
     info.context->drawLine(IntPoint(tx, ty + offsetHeight()), IntPoint(tx + offsetWidth(), ty + offsetHeight()));
     info.context->drawLine(IntPoint(tx, ty), IntPoint(tx, ty + offsetHeight()));
     
+    int topStart = paddingTop();
+    
+    info.context->setStrokeColor(Color(0, 255, 0), sRGBColorSpace);
+    
+    info.context->drawLine(IntPoint(tx, ty + topStart), IntPoint(tx + offsetWidth(), ty + topStart));
+    
     int baseline = baselinePosition(true);
     
     info.context->setStrokeColor(Color(255, 0, 0), sRGBColorSpace);
diff --git a/WebCore/mathml/RenderMathMLFraction.cpp b/WebCore/mathml/RenderMathMLFraction.cpp
index 3399e55..811c230 100644
--- a/WebCore/mathml/RenderMathMLFraction.cpp
+++ b/WebCore/mathml/RenderMathMLFraction.cpp
@@ -127,14 +127,6 @@ void RenderMathMLFraction::layout()
     if (lastChild() && lastChild()->isRenderBlock())
         m_lineThickness = m_lineThickness * ceil(gFractionBarWidth * style()->fontSize());
     
-    if (previousSibling() && previousSibling()->isRenderBlock()) {
-        RenderBlock* sibling = toRenderBlock(previousSibling());
-        verticalAlignCompute(sibling);
-    } else if (nextSibling() && nextSibling()->isRenderBlock()) {
-        RenderBlock* sibling = toRenderBlock(nextSibling());
-        verticalAlignCompute(sibling);
-    }
-
     RenderBlock::layout();
     
     // The row layout can affect the numerator/denominator width.
@@ -183,21 +175,15 @@ void RenderMathMLFraction::paint(PaintInfo& info, int tx, int ty)
     info.context->restore();
 }
 
-void RenderMathMLFraction::verticalAlignCompute(RenderBlock* sibling)
-{
-    if (sibling->isRenderMathMLBlock()) {
-        RenderMathMLBlock* op = toRenderMathMLBlock(sibling);
-        style()->setVerticalAlign(LENGTH);
-        int verticalShift = static_cast<int>(ceil(gFractionAlignment * op->offsetHeight() + 0.5 * lastChild()->style()->borderTopWidth()));
-        style()->setVerticalAlignLength(Length(verticalShift, Fixed));
-    }
-}
-
 int RenderMathMLFraction::baselinePosition(bool firstLine, bool isRootLineBox) const
 {
     if (firstChild()->isRenderMathMLBlock()) {
         RenderMathMLBlock* numerator = toRenderMathMLBlock(firstChild());
-        return numerator->offsetHeight();
+        // FIXME: the baseline should adjust so the fraction line aligns
+        // relative certain operators (e.g. aligns with the horizontal
+        // stroke of the plus).  1/3 of the current font size is just
+        // a good guess.
+        return numerator->offsetHeight() + style()->fontSize() / 3;
     }
     return RenderBlock::baselinePosition(firstLine, isRootLineBox);
 }
diff --git a/WebCore/mathml/RenderMathMLFraction.h b/WebCore/mathml/RenderMathMLFraction.h
index 30162ac..c8c1cb8 100644
--- a/WebCore/mathml/RenderMathMLFraction.h
+++ b/WebCore/mathml/RenderMathMLFraction.h
@@ -43,7 +43,6 @@ public:
 protected:
     virtual void layout();
 private:
-    void verticalAlignCompute(RenderBlock*);
     int m_lineThickness;
 };
 
diff --git a/WebCore/mathml/RenderMathMLOperator.cpp b/WebCore/mathml/RenderMathMLOperator.cpp
index 1ab3409..911c5d2 100644
--- a/WebCore/mathml/RenderMathMLOperator.cpp
+++ b/WebCore/mathml/RenderMathMLOperator.cpp
@@ -56,11 +56,14 @@ bool RenderMathMLOperator::isChildAllowed(RenderObject*, RenderStyle*) const
     return false;
 }
 
+static const float gOperatorSpacer = 0.1;
+static const float gOperatorExpansion = 1.2;
+
 void  RenderMathMLOperator::stretchToHeight(int height)
 {
     if (height == m_stretchHeight)
         return;
-    m_stretchHeight = height;
+    m_stretchHeight = static_cast<int>(height * gOperatorExpansion);
     
     updateBoxModelInfoFromStyle();
     setNeedsLayoutAndPrefWidthsRecalc();
@@ -110,6 +113,7 @@ static const int gMinimumStretchHeight = 24;
 static const int gGlyphHeight = 10;
 static const int gMiddleGlyphTopAdjust = -2;
 static const int gBottomGlyphTopAdjust = -4;
+static const float gMinimumRatioForStretch = 0.10;
 
 void RenderMathMLOperator::updateFromElement()
 {
@@ -161,15 +165,16 @@ void RenderMathMLOperator::updateFromElement()
     
     // We only stretch character if the stretch height is larger than a minimum size (e.g. 24px).
     bool shouldStretch = isStretchy && m_stretchHeight>gMinimumStretchHeight;
+    m_isCentered = true;
     
     // Either stretch is disabled or we don't have a stretchable character over the minimum height
     if (stretchDisabled || !shouldStretch) {
         m_isStacked = false;
-        RenderBlock* container = new (renderArena()) RenderBlock(node());
+        RenderBlock* container = new (renderArena()) RenderMathMLBlock(node());
         
         RefPtr<RenderStyle> newStyle = RenderStyle::create();
         newStyle->inheritFrom(style());
-        newStyle->setDisplay(BLOCK);
+        newStyle->setDisplay(INLINE_BLOCK);
 
         // Check for a stretchable character that is under the minimum height and use the
         // font size to adjust the glyph size.
@@ -181,9 +186,20 @@ void RenderMathMLOperator::updateFromElement()
             desc->setComputedSize(m_stretchHeight);
             newStyle->setFontDescription(*desc);
             newStyle->font().update(newStyle->font().fontSelector());
+            newStyle->setVerticalAlign(BASELINE);
+            m_isCentered = false;
+        } else {
+            int topPad = (m_stretchHeight - currentFontSize) / 2;
+            
+            if (topPad / static_cast<float>(m_stretchHeight) > gMinimumRatioForStretch) {
+                newStyle->setVerticalAlign(TOP);
+                newStyle->setPaddingTop(Length(topPad, Fixed));
+            } else {
+                m_isCentered = false;
+                newStyle->setVerticalAlign(BASELINE);
+            }
         }
         
-        newStyle->setVerticalAlign(BASELINE);
         container->setStyle(newStyle.release());
         addChild(container);
      
@@ -196,7 +212,9 @@ void RenderMathMLOperator::updateFromElement()
                 text = new (renderArena()) RenderText(node(), StringImpl::create(mo->textContent().characters(), mo->textContent().length()));
         // If we can't figure out the text, leave it blank.
         if (text) {
-            text->setStyle(container->style());
+            RefPtr<RenderStyle> textStyle = RenderStyle::create();
+            textStyle->inheritFrom(container->style());
+            text->setStyle(textStyle.release());
             container->addChild(text);
         }
     } else {
@@ -296,7 +314,7 @@ RefPtr<RenderStyle> RenderMathMLOperator::createStackableStyle(int size, int top
 
 RenderBlock* RenderMathMLOperator::createGlyph(UChar glyph, int size, int charRelative, int topRelative)
 {
-    RenderBlock* container = new (renderArena()) RenderBlock(node());
+    RenderBlock* container = new (renderArena()) RenderMathMLBlock(node());
     container->setStyle(createStackableStyle(size, topRelative).release());
     addChild(container);
     RenderBlock* parent = container;
@@ -320,7 +338,11 @@ RenderBlock* RenderMathMLOperator::createGlyph(UChar glyph, int size, int charRe
 
 int RenderMathMLOperator::baselinePosition(bool firstLine, bool isRootLineBox) const
 {
-    return !m_isStacked && firstChild() ? firstChild()->baselinePosition(firstLine, isRootLineBox) : offsetHeight();
+    if (m_isStacked)
+        return m_stretchHeight * 2 / 3 - (m_stretchHeight - static_cast<int>(m_stretchHeight / gOperatorExpansion)) / 2;
+    if (m_isCentered && firstChild()) 
+        return firstChild()->baselinePosition(firstLine, isRootLineBox);
+    return RenderBlock::baselinePosition(firstLine, isRootLineBox);
 }
 
 }
diff --git a/WebCore/mathml/RenderMathMLOperator.h b/WebCore/mathml/RenderMathMLOperator.h
index 6566dd7..cc183c3 100644
--- a/WebCore/mathml/RenderMathMLOperator.h
+++ b/WebCore/mathml/RenderMathMLOperator.h
@@ -50,6 +50,7 @@ protected:
 private:
     int m_stretchHeight;
     bool m_isStacked;
+    bool m_isCentered;
     UChar m_operator;
 };
 
diff --git a/WebCore/mathml/RenderMathMLRoot.cpp b/WebCore/mathml/RenderMathMLRoot.cpp
index 23e3519..c624539 100644
--- a/WebCore/mathml/RenderMathMLRoot.cpp
+++ b/WebCore/mathml/RenderMathMLRoot.cpp
@@ -97,6 +97,9 @@ void RenderMathMLRoot::paint(PaintInfo& info, int tx, int ty)
 {
     RenderMathMLBlock::paint(info , tx , ty);
     
+    if (info.context->paintingDisabled())
+        return;
+    
     tx += x();
     ty += y();
     
@@ -145,7 +148,7 @@ void RenderMathMLRoot::paint(PaintInfo& info, int tx, int ty)
     
     info.context->setStrokeThickness(gRadicalLineThickness * style()->fontSize());
     info.context->setStrokeStyle(SolidStroke);
-    info.context->setStrokeColor(style()->color(), sRGBColorSpace);
+    info.context->setStrokeColor(style()->visitedDependentColor(CSSPropertyColor), sRGBColorSpace);
     info.context->setLineJoin(MiterJoin);
     info.context->setMiterLimit(style()->fontSize());
     
@@ -204,8 +207,7 @@ void RenderMathMLRoot::layout()
     int maxHeight = toRenderBoxModelObject(lastChild())->offsetHeight();
     
     RenderObject* current = lastChild()->firstChild();
-    
-    toRenderMathMLBlock(current)->style()->setVerticalAlign(BASELINE);
+    current->style()->setVerticalAlign(BASELINE);
     
     if (!maxHeight)
         maxHeight = style()->fontSize();
@@ -238,9 +240,11 @@ void RenderMathMLRoot::layout()
     setNeedsLayoutAndPrefWidthsRecalc();
     markContainingBlocksForLayout();
     RenderBlock::layout();
-    
+
     indexBox->style()->setBottom(Length(radicalHeight + style()->paddingBottom().value(), Fixed));
-    
+
+    // Now that we've potentially changed its position, we need layout the index again.
+    indexBox->setNeedsLayoutAndPrefWidthsRecalc();
     indexBox->layout();
 }
     
diff --git a/WebCore/mathml/RenderMathMLRow.cpp b/WebCore/mathml/RenderMathMLRow.cpp
index 1bb656f..acbfb9d 100644
--- a/WebCore/mathml/RenderMathMLRow.cpp
+++ b/WebCore/mathml/RenderMathMLRow.cpp
@@ -69,9 +69,6 @@ void RenderMathMLRow::layout()
     // Calculate the maximum height of the row without the operators.
     int maxHeight = nonOperatorHeight();
     
-    // Set the maximum height of the row for intermediate layouts.
-    style()->setHeight(Length(maxHeight, Fixed));
-
     // Notify contained operators they may need to re-layout their stretched operators.
     // We need to keep track of the number of children and operators because a row of
     // operators needs some special handling.
@@ -141,16 +138,24 @@ void RenderMathMLRow::layout()
                 maxHeight = box->offsetHeight();
         }
     }
-
-    // Set the maximum height of the row based on the calculations.
-    style()->setHeight(Length(maxHeight, Fixed));
     
-    // Do the final layout by calling our parent's layout again.
+    // Mark outself as needing layout and do the final layout of the row.
     setNeedsLayoutAndPrefWidthsRecalc();
     markContainingBlocksForLayout();
     RenderBlock::layout();
-}
+}    
 
+int RenderMathMLRow::baselinePosition(bool firstLine, bool isRootLineBox) const
+{
+    if (firstChild() && firstChild()->isRenderMathMLBlock()) {
+        RenderMathMLBlock* block = toRenderMathMLBlock(firstChild());
+        if (block->isRenderMathMLOperator())
+            return block->baselinePosition(firstLine, isRootLineBox);
+    }
+    
+    return RenderBlock::baselinePosition(firstLine, isRootLineBox);
+}
+    
 }
 
 #endif // ENABLE(MATHML)
diff --git a/WebCore/mathml/RenderMathMLRow.h b/WebCore/mathml/RenderMathMLRow.h
index a88b212..83c6832 100644
--- a/WebCore/mathml/RenderMathMLRow.h
+++ b/WebCore/mathml/RenderMathMLRow.h
@@ -37,6 +37,7 @@ public:
     RenderMathMLRow(Node* container);
     virtual bool isRenderMathMLRow() const { return true; }
     virtual int nonOperatorHeight() const;
+    virtual int baselinePosition(bool , bool) const;    
 protected:
     virtual void layout();
 };
diff --git a/WebCore/mathml/RenderMathMLSquareRoot.cpp b/WebCore/mathml/RenderMathMLSquareRoot.cpp
index fc0a16d..6802176 100644
--- a/WebCore/mathml/RenderMathMLSquareRoot.cpp
+++ b/WebCore/mathml/RenderMathMLSquareRoot.cpp
@@ -69,6 +69,9 @@ void RenderMathMLSquareRoot::paint(PaintInfo& info, int tx, int ty)
 {
     RenderMathMLBlock::paint(info, tx, ty);
    
+    if (info.context->paintingDisabled())
+        return;
+    
     tx += x();
     ty += y();
 
@@ -114,7 +117,7 @@ void RenderMathMLSquareRoot::paint(PaintInfo& info, int tx, int ty)
     
     info.context->setStrokeThickness(gRadicalLineThickness * style()->fontSize());
     info.context->setStrokeStyle(SolidStroke);
-    info.context->setStrokeColor(style()->color(), sRGBColorSpace);
+    info.context->setStrokeColor(style()->visitedDependentColor(CSSPropertyColor), sRGBColorSpace);
     info.context->setLineJoin(MiterJoin);
     info.context->setMiterLimit(style()->fontSize());
     
diff --git a/WebCore/mathml/RenderMathMLSubSup.cpp b/WebCore/mathml/RenderMathMLSubSup.cpp
index 3124ac9..af25980 100644
--- a/WebCore/mathml/RenderMathMLSubSup.cpp
+++ b/WebCore/mathml/RenderMathMLSubSup.cpp
@@ -72,7 +72,7 @@ void RenderMathMLSubSup::addChild(RenderObject* child, RenderObject* beforeChild
                 RefPtr<RenderStyle> scriptsStyle = RenderStyle::create();
                 scriptsStyle->inheritFrom(style());
                 scriptsStyle->setDisplay(INLINE_BLOCK);
-                scriptsStyle->setVerticalAlign(MIDDLE);
+                scriptsStyle->setVerticalAlign(TOP);
                 scriptsStyle->setMarginLeft(Length(gSubsupScriptMargin, Fixed));
                 scriptsStyle->setTextAlign(LEFT);
                 m_scripts->setStyle(scriptsStyle.release());
@@ -95,7 +95,7 @@ void RenderMathMLSubSup::addChild(RenderObject* child, RenderObject* beforeChild
         RefPtr<RenderStyle> wrapperStyle = RenderStyle::create();
         wrapperStyle->inheritFrom(style());
         wrapperStyle->setDisplay(INLINE_BLOCK);
-        wrapperStyle->setVerticalAlign(MIDDLE);
+        wrapperStyle->setVerticalAlign(TOP);
         wrapper->setStyle(wrapperStyle.release());
         RenderMathMLBlock::addChild(wrapper, beforeChild);
         wrapper->addChild(child);
@@ -141,21 +141,32 @@ int RenderMathMLSubSup::nonOperatorHeight() const
 
 void RenderMathMLSubSup::layout() 
 {
+    if (firstChild()) {
+        firstChild()->setNeedsLayoutAndPrefWidthsRecalc();
+        firstChild()->markContainingBlocksForLayout();
+    }
+    if (m_scripts) {
+        m_scripts->setNeedsLayoutAndPrefWidthsRecalc();
+        m_scripts->markContainingBlocksForLayout();
+    }
     RenderBlock::layout();
     
     if (m_kind == SubSup) {
-        int width = 0;
-        RenderObject* current = firstChild();
-        while (current) {
-            width += getBoxModelObjectWidth(current);
-            current = current->nextSibling();
+        RenderObject* base = firstChild();
+        if (base) {
+            int maxHeight = 0;
+            RenderObject* current = base->firstChild();
+            while (current) {
+                int height = getBoxModelObjectHeight(current);
+                if (height > maxHeight)
+                    maxHeight = height;
+                current = current->nextSibling();
+            }
+            int heightDiff = (m_scripts->offsetHeight() - maxHeight) / 2;
+            if (heightDiff < 0) 
+                heightDiff = 0;
+            base->style()->setMarginTop(Length(heightDiff, Fixed));
         }
-        width++;
-        // 1 + margin of scripts
-        if (m_scripts) 
-            width += gSubsupScriptMargin;
-        style()->setWidth(Length(width, Fixed));
-
         setNeedsLayoutAndPrefWidthsRecalc();
         markContainingBlocksForLayout();
         RenderBlock::layout();
@@ -181,7 +192,10 @@ int RenderMathMLSubSup::baselinePosition(bool firstLine, bool isRootLineBox) con
                 RenderBoxModelObject* box = toRenderBoxModelObject(base);
                 topAdjust = (m_scripts->offsetHeight() - box->offsetHeight()) / 2;
             }
-            return topAdjust + (base ? base->baselinePosition(firstLine, isRootLineBox) : 0) + 4;
+            // FIXME: The last bit of this calculation should be more exact.  Why is the 2-3px scaled for zoom necessary?
+            // The baseline is top spacing of the base + the baseline of the base + adjusted space for zoom
+            float zoomFactor = style()->effectiveZoom();
+            return topAdjust + base->baselinePosition(firstLine, isRootLineBox) + static_cast<int>((zoomFactor > 1.25 ? 2 : 3) * zoomFactor);
         }
         break;
     case Sup:
diff --git a/WebCore/mathml/RenderMathMLUnderOver.cpp b/WebCore/mathml/RenderMathMLUnderOver.cpp
index 514b872..ad32d59 100644
--- a/WebCore/mathml/RenderMathMLUnderOver.cpp
+++ b/WebCore/mathml/RenderMathMLUnderOver.cpp
@@ -234,7 +234,7 @@ void RenderMathMLUnderOver::layout()
     RenderBlock::layout();
 }
 
-int RenderMathMLUnderOver::baselinePosition(bool, bool) const
+int RenderMathMLUnderOver::baselinePosition(bool firstLine, bool isRootLineBox) const
 {
     int baseline = 0;
     RenderObject* current = 0;
@@ -247,9 +247,12 @@ int RenderMathMLUnderOver::baselinePosition(bool, bool) const
         if (current) {
             // actual base
             RenderObject* base = current->firstChild();
-            baseline += base->baselinePosition(true);
+            baseline += base->baselinePosition(firstLine, isRootLineBox);
             // added the negative top margin
             baseline += current->style()->marginTop().value();
+            // FIXME: Where is the extra 2-3px adjusted for zoom coming from?
+            float zoomFactor = style()->effectiveZoom();
+            baseline += static_cast<int>((zoomFactor > 1.25 ? 2 : 3) * zoomFactor);
         }
         break;
     case Under:
@@ -257,6 +260,9 @@ int RenderMathMLUnderOver::baselinePosition(bool, bool) const
         if (current) {
             RenderObject* base = current->firstChild();
             baseline += base->baselinePosition(true);
+            // FIXME: Where is the extra 2-3px adjusted for zoom coming from?
+            float zoomFactor = style()->effectiveZoom();
+            baseline += static_cast<int>((zoomFactor > 1.25 ? 2 : 3) * zoomFactor);
         }
     }
     return baseline;