Clamp shape-margin to zero

Source/core/layout/shapes/ShapeOutsideInfo.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 135 matching lines @@
     if (Shape* shape = m_shape.get())
         return *shape;
 
     TemporaryChange<bool> isInComputingShape(m_isComputingShape, true);
 
     const ComputedStyle& style = *m_renderer.style();
     ASSERT(m_renderer.containingBlock());
     const ComputedStyle& containingBlockStyle = *m_renderer.containingBlock()->style();
 
     WritingMode writingMode = containingBlockStyle.writingMode();
-    LayoutUnit maximumValue = m_renderer.containingBlock() ? m_renderer.containingBlock()->contentWidth() : LayoutUnit();
+    LayoutUnit maximumValue;
+    if (m_renderer.containingBlock() && m_renderer.containingBlock()->contentWidth() > 0)

[leviw_travelin_and_unemployed, 2015/04/14 21:12:31]

The contentWidth() is negative? That doesn't seem right... Why is this
happening? This seems like the wrong place for this fix.

+        maximumValue = m_renderer.containingBlock()->contentWidth();
     float margin = floatValueForLength(m_renderer.style()->shapeMargin(), maximumValue.toFloat());
 
     float shapeImageThreshold = style.shapeImageThreshold();
     ASSERT(style.shapeOutside());
     const ShapeValue& shapeValue = *style.shapeOutside();
 
     switch (shapeValue.type()) {
     case ShapeValue::Shape:
         ASSERT(shapeValue.shape());
         m_shape = Shape::createShape(shapeValue.shape(), m_referenceBoxLogicalSize, writingMode, margin);
@@ skipping 178 matching lines @@
 }
 
 FloatSize ShapeOutsideInfo::shapeToRendererSize(FloatSize size) const
 {
     if (!m_renderer.style()->isHorizontalWritingMode())
         return size.transposedSize();
     return size;
 }
 
 } // namespace blink