[SVG] Reject hit-test queries when the element has a singular transform

Source/core/rendering/svg/RenderSVGRoot.cpp

Index: Source/core/rendering/svg/RenderSVGRoot.cpp
diff --git a/Source/core/rendering/svg/RenderSVGRoot.cpp b/Source/core/rendering/svg/RenderSVGRoot.cpp
index c570efefd0ae8908dec836ab08c28cf22ffc16c6..6d554622faaed5e156de2f4ac828c7b9af446eee 100644
--- a/Source/core/rendering/svg/RenderSVGRoot.cpp
+++ b/Source/core/rendering/svg/RenderSVGRoot.cpp
@@ -425,14 +425,17 @@ bool RenderSVGRoot::nodeAtPoint(const HitTestRequest& request, HitTestResult& re
     // Only test SVG content if the point is in our content box.
     // FIXME: This should be an intersection when rect-based hit tests are supported by nodeAtFloatPoint.
     if (contentBoxRect().contains(pointInBorderBox)) {
-        FloatPoint localPoint = localToParentTransform().inverse().mapPoint(FloatPoint(pointInParent));
-
-        for (RenderObject* child = lastChild(); child; child = child->previousSibling()) {
-            // FIXME: nodeAtFloatPoint() doesn't handle rect-based hit tests yet.
-            if (child->nodeAtFloatPoint(request, result, localPoint, hitTestAction)) {
-                updateHitTestResult(result, pointInBorderBox);
-                if (!result.addNodeToRectBasedTestResult(child->node(), request, locationInContainer))
-                    return true;
+        const AffineTransform& localToParentTransform = this->localToParentTransform();
+        if (localToParentTransform.isInvertible()) {
+            FloatPoint localPoint = localToParentTransform.inverse().mapPoint(FloatPoint(pointInParent));
+
+            for (RenderObject* child = lastChild(); child; child = child->previousSibling()) {
+                // FIXME: nodeAtFloatPoint() doesn't handle rect-based hit tests yet.
+                if (child->nodeAtFloatPoint(request, result, localPoint, hitTestAction)) {
+                    updateHitTestResult(result, pointInBorderBox);
+                    if (!result.addNodeToRectBasedTestResult(child->node(), request, locationInContainer))
+                        return true;
+                }
             }
         }
     }