[CSS Shapes] Normalize margin box size

Source/core/layout/shapes/ShapeOutsideInfo.cpp

Index: Source/core/layout/shapes/ShapeOutsideInfo.cpp
diff --git a/Source/core/layout/shapes/ShapeOutsideInfo.cpp b/Source/core/layout/shapes/ShapeOutsideInfo.cpp
index 8e2f81d369b722b9b5020478835df591fe79ed71..a1535ed73ef62c7735280198626278db5c0c1eb9 100644
--- a/Source/core/layout/shapes/ShapeOutsideInfo.cpp
+++ b/Source/core/layout/shapes/ShapeOutsideInfo.cpp
@@ -56,6 +56,10 @@ void ShapeOutsideInfo::setReferenceBoxLogicalSize(LayoutSize newReferenceBoxLogi
             newReferenceBoxLogicalSize.expand(m_renderer.marginWidth(), m_renderer.marginHeight());
         else
             newReferenceBoxLogicalSize.expand(m_renderer.marginHeight(), m_renderer.marginWidth());
+        if (newReferenceBoxLogicalSize.isEmpty()) {

[bjonesbe, 2015/03/16 22:26:34]

Sorry I missed this earlier, but in this case you could just set
newReferenceBoxLogicalSize to LayoutSize(), as I don't think there's any
situation where one of the dimensions can have a 0 length and still be able to
create a shape with an extent.

+            newReferenceBoxLogicalSize.setWidth(newReferenceBoxLogicalSize.width().clamp(0.0));
+            newReferenceBoxLogicalSize.setHeight(newReferenceBoxLogicalSize.height().clamp(0.0));
+        }
         break;
     case BorderBox:
         break;
@@ -287,7 +291,7 @@ ShapeOutsideDeltas ShapeOutsideInfo::computeDeltasForContainingBlockLine(const L
 
     if (isShapeDirty() || !m_shapeOutsideDeltas.isForLine(borderBoxLineTop, lineHeight)) {
         LayoutUnit referenceBoxLineTop = borderBoxLineTop - logicalTopOffset();
-        LayoutUnit floatMarginBoxWidth = containingBlock.logicalWidthForFloat(&floatingObject);
+        LayoutUnit floatMarginBoxWidth = containingBlock.logicalWidthForFloat(&floatingObject).abs();

[bjonesbe, 2015/03/16 22:26:34]

This one also needs to clamp to 0, as a float with negative width has no float
area.

 
         if (computedShape().lineOverlapsShapeMarginBounds(referenceBoxLineTop, lineHeight)) {
             LineSegment segment = computedShape().getExcludedInterval((borderBoxLineTop - logicalTopOffset()), std::min(lineHeight, shapeLogicalBottom() - borderBoxLineTop));