[CSS Shapes] shape-margin in percentage units always computes to 0px

Source/core/rendering/shapes/ShapeInfo.cpp

 /*
  * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above
  *    copyright notice, this list of conditions and the following
  *    disclaimer.
@@ skipping 15 matching lines @@
  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/rendering/shapes/ShapeInfo.h"
 
 #include "core/rendering/RenderBlock.h"
 #include "core/rendering/RenderImage.h"
 
+#include "platform/LengthFunctions.h"
+
 namespace WebCore {
 
 template<class RenderType>
 void ShapeInfo<RenderType>::setReferenceBoxLogicalSize(LayoutSize newReferenceBoxLogicalSize)
 {
     bool isHorizontalWritingMode = this->styleForWritingMode()->isHorizontalWritingMode();
     switch (referenceBox()) {
     case MarginBox:
         if (isHorizontalWritingMode)
             newReferenceBoxLogicalSize.expand(m_renderer.marginWidth(), m_renderer.marginHeight());
@@ skipping 59 matching lines @@
     return LayoutRect(marginBoxOrigin, referenceBoxLogicalSize + marginBoxSizeDelta);
 }
 
 template<class RenderType>
 const Shape& ShapeInfo<RenderType>::computedShape() const
 {
     if (Shape* shape = m_shape.get())
         return *shape;
 
     WritingMode writingMode = this->styleForWritingMode()->writingMode();
-    Length margin = m_renderer.style()->shapeMargin();
+    LayoutUnit maximumValue = m_renderer.containingBlock() ? m_renderer.containingBlock()->contentWidth() : LayoutUnit();

[Bem Jones-Bey (adobe), 2014/04/04 23:03:53]

Isn't there an implicit conversion from LayoutUnit to float? If so, wouldn't
using 0.0f instead of LayoutUnit() here mean that you could store this in a
float and not need the explicit toFloat() below?

[leviw_travelin_and_unemployed, 2014/04/07 17:54:38]

We're actually working on killing the implicit conversions to/from LayoutUnits,
as they're quite prone to misuse.

+    float margin = floatValueForLength(m_renderer.style()->shapeMargin(), maximumValue.toFloat());
     float shapeImageThreshold = m_renderer.style()->shapeImageThreshold();
     const ShapeValue* shapeValue = this->shapeValue();
     ASSERT(shapeValue);
 
     switch (shapeValue->type()) {
     case ShapeValue::Shape:
         ASSERT(shapeValue->shape());
         m_shape = Shape::createShape(shapeValue->shape(), m_referenceBoxLogicalSize, writingMode, margin);
         break;
     case ShapeValue::Image: {
@@ skipping 118 matching lines @@
     case BoxMissing: break;
     }
 
     ASSERT_NOT_REACHED();
     return LayoutUnit();
 }
 
 template class ShapeInfo<RenderBlock>;
 template class ShapeInfo<RenderBox>;
 }