Bug 1137859 - stroke-dashoffset not respecting pathLength property. r=dholbert

--HG--
rename : layout/reftests/svg/stroke-dasharray-and-pathLength-01.svg => layout/reftests/svg/stroke-dashoffset-and-pathLength-01.svg

dom/svg/SVGContentUtils.cpp

@@ -76,6 +76,7 @@ GetStrokeDashData(SVGContentUtils::AutoStrokeOptions* aStrokeOptions,
 {
   size_t dashArrayLength;
   Float totalLengthOfDashes = 0.0, totalLengthOfGaps = 0.0;
+  Float pathScale = 1.0;
 
   if (aContextPaint && aStyleSVG->mStrokeDasharrayFromObject) {
     const FallibleTArray<gfxFloat>& dashSrc = aContextPaint->GetStrokeDashArray();
@@ -100,7 +101,6 @@ GetStrokeDashData(SVGContentUtils::AutoStrokeOptions* aStrokeOptions,
     if (dashArrayLength <= 0) {
       return eContinuousStroke;
     }
-    Float pathScale = 1.0;
     if (aElement->IsSVGElement(nsGkAtoms::path)) {
       pathScale = static_cast<SVGPathElement*>(aElement)->
         GetPathLengthScale(SVGPathElement::eForStroking);
@@ -161,7 +161,8 @@ GetStrokeDashData(SVGContentUtils::AutoStrokeOptions* aStrokeOptions,
     aStrokeOptions->mDashOffset = Float(aContextPaint->GetStrokeDashOffset());
   } else {
     aStrokeOptions->mDashOffset =
-      SVGContentUtils::CoordToFloat(aElement, aStyleSVG->mStrokeDashoffset);
+      SVGContentUtils::CoordToFloat(aElement, aStyleSVG->mStrokeDashoffset) *
+      pathScale;
   }
 
   return eDashedStroke;

layout/reftests/svg/reftest.list

@@ -338,6 +338,7 @@ HTTP(..) == text-scale-03.svg text-scale-03-ref.svg
 == stroke-dasharray-and-pathLength-01.svg pass.svg
 == stroke-dasharray-and-text-01.svg stroke-dasharray-and-text-01-ref.svg
 == stroke-dashoffset-01.svg pass.svg
+== stroke-dashoffset-and-pathLength-01.svg pass.svg
 == stroke-linecap-round-w-zero-length-segs-01.svg pass.svg
 == stroke-linecap-round-w-zero-length-segs-02.svg pass.svg
 == stroke-linecap-square-w-zero-length-segs-01.svg pass.svg

layout/reftests/svg/stroke-dashoffset-and-pathLength-01.svg

@@ -0,0 +1,25 @@
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<svg xmlns="http://www.w3.org/2000/svg">
+  <title>Test stroke-dashoffset with pathLength</title>
+  <!--
+    The path is much longer than 100 user units, so if the pathLength is not
+    factored into the stroke-dashoffset calculation, the stroke will be visible.
+    A correct implementation will see the first dash pushed off the end of the
+    path which will mean that the path does not display at all.
+  -->
+  <style>
+    path {
+      fill: none;
+      stroke-width: 5;
+      stroke: red;
+      stroke-dasharray: 100;
+      stroke-dashoffset: 100;
+    }
+  </style>
+  <rect width="100%" height="100%" fill="lime"/>
+
+  <path pathLength="100" d="M175,25 A150,150,0,1,1,175,325 A150,150,0,1,1,175,25"/>
+</svg>