Fix an issue where hit detection could fail on rect and ellipse shapes

Source/core/rendering/svg/RenderSVGEllipse.cpp

 /*
  * Copyright (C) 2012 Google, Inc.
  * 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.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 42 matching lines @@
     m_radii = FloatSize();
     m_usePathFallback = false;
 
     calculateRadiiAndCenter();
 
     // Spec: "A negative value is an error. A value of zero disables rendering of the element."
     if (m_radii.width() < 0 || m_radii.height() < 0)
         return;
 
     if (!m_radii.isEmpty()) {
-        // Fallback to RenderSVGShape if shape has a non-scaling stroke.
-        if (hasNonScalingStroke()) {
+        // Fallback to RenderSVGShape and path-based hit detection if the ellipse
+        // has a non-scaling or discontinuous stroke.
+        if (hasNonScalingStroke() || !hasContinuousStroke()) {
             RenderSVGShape::updateShapeFromElement();
             m_usePathFallback = true;
             return;
         }
     }
 
     m_fillBoundingBox = FloatRect(m_center.x() - m_radii.width(), m_center.y() - m_radii.height(), 2 * m_radii.width(), 2 * m_radii.height());
     m_strokeBoundingBox = m_fillBoundingBox;
     if (style()->svgStyle().hasStroke())
         m_strokeBoundingBox.inflate(strokeWidth() / 2);
@@ skipping 14 matching lines @@
 
     SVGEllipseElement& ellipse = toSVGEllipseElement(*element());
 
     SVGLengthContext lengthContext(&ellipse);
     m_radii = FloatSize(ellipse.rx()->currentValue()->value(lengthContext), ellipse.ry()->currentValue()->value(lengthContext));
     m_center = FloatPoint(ellipse.cx()->currentValue()->value(lengthContext), ellipse.cy()->currentValue()->value(lengthContext));
 }
 
 bool RenderSVGEllipse::shapeDependentStrokeContains(const FloatPoint& point)
 {
-    // The optimized contains code below does not support non-smooth strokes so we need
+    // The optimized code below does not support discontinuous strokes so we need
     // to fall back to RenderSVGShape::shapeDependentStrokeContains in these cases.
-    if (m_usePathFallback || !hasSmoothStroke()) {
+    if (m_usePathFallback || !hasContinuousStroke()) {
         if (!hasPath())
             RenderSVGShape::updateShapeFromElement();
         return RenderSVGShape::shapeDependentStrokeContains(point);
     }
 
     float halfStrokeWidth = strokeWidth() / 2;
     FloatPoint center = FloatPoint(m_center.x() - point.x(), m_center.y() - point.y());
 
     // This works by checking if the point satisfies the ellipse equation,
     // (x/rX)^2 + (y/rY)^2 <= 1, for the outer but not the inner stroke.
@@ skipping 14 matching lines @@
 
     FloatPoint center = FloatPoint(m_center.x() - point.x(), m_center.y() - point.y());
 
     // This works by checking if the point satisfies the ellipse equation.
     // (x/rX)^2 + (y/rY)^2 <= 1
     float xrX = center.x() / m_radii.width();
     float yrY = center.y() / m_radii.height();
     return xrX * xrX + yrY * yrY <= 1.0;
 }
 
+bool RenderSVGEllipse::hasContinuousStroke() const
+{
+    const SVGRenderStyle& svgStyle = style()->svgStyle();
+    return svgStyle.strokeDashArray()->isEmpty();
 }
+
+}