Bug 1532156 - correct marker-start for closed paths so it is the average of the start and end angles i.e. the same as marker-end r=dholbert

dom/svg/SVGPathData.cpp

@@ -757,6 +757,7 @@ void SVGPathData::GetMarkerPositioningData(nsTArray<SVGMark>* aMarks) const {
   // info on current [sub]path (reset every M command):
   Point pathStart(0.0, 0.0);
   float pathStartAngle = 0.0f;
+  uint32_t pathStartIndex = 0;
 
   // info on previous segment:
   uint16_t prevSegType = PATHSEG_UNKNOWN;
@@ -788,6 +789,7 @@ void SVGPathData::GetMarkerPositioningData(nsTArray<SVGMark>* aMarks) const {
           segEnd = segStart + Point(mData[i], mData[i + 1]);
         }
         pathStart = segEnd;
+        pathStartIndex = aMarks->Length();
         // If authors are going to specify multiple consecutive moveto commands
         // with markers, me might as well make the angle do something useful:
         segStartAngle = segEndAngle = AngleOfVector(segEnd, segStart);
@@ -1042,8 +1044,7 @@ void SVGPathData::GetMarkerPositioningData(nsTArray<SVGMark>* aMarks) const {
     }
 
     if (segType == PATHSEG_CLOSEPATH && prevSegType != PATHSEG_CLOSEPATH) {
-      aMarks->LastElement().angle =
-          // aMarks->ElementAt(pathStartIndex).angle =
+      aMarks->LastElement().angle = aMarks->ElementAt(pathStartIndex).angle =
           SVGContentUtils::AngleBisect(segEndAngle, pathStartAngle);
     }
 

layout/reftests/svg/marker-orientation-05.svg

@@ -0,0 +1,20 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="100%" height="100%">
+    <defs>
+        <marker id="arrowAutoStartRev" orient="auto-start-reverse" markerUnits="userSpaceOnUse" overflow="visible">
+            <path d="M25,25 L0,0 L0,50 z" fill="lime" stroke="lime" stroke-width="2" />
+        </marker>
+        <marker id="arrowSW" orient="135" markerUnits="userSpaceOnUse" overflow="visible">
+            <path d="M25,25 L0,0 L0,50 z" fill="red"/>
+        </marker>
+        <marker id="arrowAuto" orient="auto" markerUnits="userSpaceOnUse" overflow="visible">
+            <path d="M25,25 L0,0 L0,50 z" fill="red"/>
+        </marker>
+     </defs>
+    <rect width="100%" height="100%" fill="lime" />
+    <path d="M 340,100 h50 v50 h-50 z" marker-start="url(#arrowSW)" fill="none"/>
+    <path d="M 340,100 h50 v50 h-50 z" marker-start="url(#arrowAutoStartRev)" fill="none"/>
+    <g transform="translate(0, 50)">
+      <path d="M 340,100 h50 v50 h-50 z" marker-start="url(#arrowAuto)" fill="none"/>
+      <path d="M 340,100 h50 v50 h-50 z" marker-end="url(#arrowAutoStartRev)" fill="none"/>
+    </g>
+</svg>

layout/reftests/svg/reftest.list

@@ -269,6 +269,7 @@ fuzzy-if(skiaContent,0-1,0-100) == marker-orientation-01.svg marker-orientation-
 fuzzy-if(skiaContent,0-1,0-5) == marker-orientation-02.svg marker-orientation-02-ref.svg
 == marker-orientation-03.svg pass.svg
 == marker-orientation-04.svg pass.svg
+== marker-orientation-05.svg pass.svg
 
 fuzzy(0-28,0-28) == mask-and-clipPath.html mask-and-clipPath-ref.html
 == mask-and-clipPath-2.svg pass.svg