Fix pointer-events:all when stroke="none"

Source/core/layout/svg/LayoutSVGPath.cpp

Index: Source/core/layout/svg/LayoutSVGPath.cpp
diff --git a/Source/core/layout/svg/LayoutSVGPath.cpp b/Source/core/layout/svg/LayoutSVGPath.cpp
index 85ea5a85b2df52b05536d168bc94521cd4733453..82ad61dc58b2d52738cb9705f215bbb0389bb24a 100644
--- a/Source/core/layout/svg/LayoutSVGPath.cpp
+++ b/Source/core/layout/svg/LayoutSVGPath.cpp
@@ -35,6 +35,8 @@
 #include "core/layout/svg/SVGSubpathData.h"
 #include "core/svg/SVGGraphicsElement.h"
 
+#include <cmath>

[fs, 2015/03/31 14:53:59]

(I think it's pretty common to just pull in wtf/MathExtras.h for this, but I
don't particularly mind either way.)

+
 namespace blink {
 
 LayoutSVGPath::LayoutSVGPath(SVGGraphicsElement* node)
@@ -55,6 +57,40 @@ void LayoutSVGPath::updateShapeFromElement()
     m_strokeBoundingBox = calculateUpdatedStrokeBoundingBox();
 }
 
+FloatRect LayoutSVGPath::hitTestStrokeBoundingBox() const
+{
+    const SVGLayoutStyle& svgStyle = style()->svgStyle();
+    if (svgStyle.hasStroke())
+        return m_strokeBoundingBox;
+
+    FloatRect result = m_fillBoundingBox;
+    const float strokeWidth = this->strokeWidth();
+
+    if (svgStyle.joinStyle() == MiterJoin) {

[fs, 2015/03/31 14:54:00]

Could you pull this out into a helper?

http://dev.w3.org/fxtf/css-masking-1/#compute-stroke-bounding-box might be worth
looking at and implementing for this (also contains adjustment for square caps).

(Could probably also reference crbug.com/435097 which is sort of related.)

+        // We need to consider the miterlimit, because the would-be stroke
+        // bounding box could extend outward quite far at a sharp angle along
+        // the path.
+        //
+        // Per http://www.w3.org/TR/SVG/painting.html#StrokeMiterlimitProperty
+        // the maximum miterLength is:
+        //     stroke-width * miterlimit
+        // Inflate the result by the maximum of that amount and half the
+        // stroke-width.
+        //
+        // Note that because the miterLength is the distance between the outer
+        // tip and the inner corner of the miter, this technically overshoots
+        // a bit.
+        result.inflate(std::max(strokeWidth * svgStyle.strokeMiterLimit(), strokeWidth / 2));
+    } else {
+        result.inflate(strokeWidth / 2);
+    }
+
+    for (size_t i = 0; i < m_zeroLengthLinecapLocations.size(); ++i)
+        result.unite(zeroLengthSubpathRect(m_zeroLengthLinecapLocations[i], strokeWidth));
+
+    return result;
+}
+
 FloatRect LayoutSVGPath::calculateUpdatedStrokeBoundingBox() const
 {
     FloatRect strokeBoundingBox = m_strokeBoundingBox;
@@ -78,9 +114,9 @@ bool LayoutSVGPath::shapeDependentStrokeContains(const FloatPoint& point)
         return true;
 
     const SVGLayoutStyle& svgStyle = style()->svgStyle();
+    const float strokeWidth = this->strokeWidth();
     for (size_t i = 0; i < m_zeroLengthLinecapLocations.size(); ++i) {
         ASSERT(svgStyle.hasStroke());
-        float strokeWidth = this->strokeWidth();
         if (svgStyle.capStyle() == SquareCap) {
             if (zeroLengthSubpathRect(m_zeroLengthLinecapLocations[i], strokeWidth).contains(point))
                 return true;