Bug 647914 - Horizontal and vertical SVG paths are omitted from bbox calculations if they have siblings. r=jwatt

content/svg/content/test/bbox-helper.svg

@@ -6,4 +6,12 @@
   <text id="b" x="20" y="20">b</text>
   <text id="a" x="20" y="30">a</text>
   <text id="y" x="20" y="40">y</text>
+  <g id="v">
+    <circle cx="100" cy="50" r="5"/>
+    <path d="M 100,100 L 100,200"/>
+  </g>
+  <g id="h">
+    <circle cx="200" cy="50" r="5"/>
+    <path d="M 200,100 L 300,100"/>
+  </g>
 </svg>

content/svg/content/test/test_bbox.xhtml

@@ -42,6 +42,8 @@ function run()
   checkBBox("f", 0, 0, 100, 100);
   checkBBoxHeight("a", "b");
   checkBBoxHeight("a", "y");
+  checkBBox("v", 95, 45, 10, 155);
+  checkBBox("h", 195, 45, 105, 55);
   
   SimpleTest.finish();
 }

layout/svg/base/src/nsSVGContainerFrame.cpp

@@ -265,7 +265,8 @@ nsSVGDisplayContainerFrame::GetBBoxContribution(
   const gfxMatrix &aToBBoxUserspace,
   PRUint32 aFlags)
 {
-  gfxRect bboxUnion(0.0, 0.0, 0.0, 0.0);
+  gfxRect bboxUnion;
+  bool firstChild = true;
 
   nsIFrame* kid = mFrames.FirstChild();
   while (kid) {
@@ -277,8 +278,16 @@ nsSVGDisplayContainerFrame::GetBBoxContribution(
         transform = static_cast<nsSVGElement*>(content)->
                       PrependLocalTransformTo(aToBBoxUserspace);
       }
-      bboxUnion =
-        bboxUnion.Union(svgKid->GetBBoxContribution(transform, aFlags));
+      // We need to include zero width/height vertical/horizontal lines, so we have
+      // to use UnionEdges, but we must special case the first bbox so that we don't
+      // include the initial gfxRect(0,0,0,0).
+      gfxRect childBBox = svgKid->GetBBoxContribution(transform, aFlags);
+      if (firstChild) {
+        bboxUnion = childBBox;
+        firstChild = false;
+        continue;
+      }
+      bboxUnion = bboxUnion.UnionEdges(childBBox);
     }
     kid = kid->GetNextSibling();
   }

layout/svg/base/src/nsSVGMarkerFrame.cpp

@@ -203,14 +203,15 @@ nsSVGMarkerFrame::GetMarkBBoxContribution(const gfxMatrix &aToBBoxUserspace,
   mY = aMark->y;
   mAutoAngle = aMark->angle;
 
-  gfxRect bbox;
-
   gfxMatrix markerTM =
     content->GetMarkerTransform(mStrokeWidth, mX, mY, mAutoAngle);
   gfxMatrix viewBoxTM = content->GetViewBoxTransform();
 
   gfxMatrix tm = viewBoxTM * markerTM * aToBBoxUserspace;
 
+  gfxRect bbox;
+  bool firstChild = true;
+
   for (nsIFrame* kid = mFrames.FirstChild();
        kid;
        kid = kid->GetNextSibling()) {
@@ -219,7 +220,17 @@ nsSVGMarkerFrame::GetMarkBBoxContribution(const gfxMatrix &aToBBoxUserspace,
       // When we're being called to obtain the invalidation area, we need to
       // pass down all the flags so that stroke is included. However, once DOM
       // getBBox() accepts flags, maybe we should strip some of those here?
-      bbox.UnionRect(bbox, child->GetBBoxContribution(tm, aFlags));
+
+      // We need to include zero width/height vertical/horizontal lines, so we have
+      // to use UnionEdges, but we must special case the first bbox so that we don't
+      // include the initial gfxRect(0,0,0,0).
+      gfxRect childBBox = child->GetBBoxContribution(tm, aFlags);
+      if (firstChild) {
+        bbox = childBBox;
+        firstChild = false;
+        continue;
+      }
+      bbox = bbox.UnionEdges(childBBox);
     }
   }