Bug 463064 - Use covered region to minimise foreignObject painting r+sr=roc

layout/reftests/svg/foreignObject-02-ref.svg

@@ -0,0 +1,20 @@
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/licenses/publicdomain/
+-->
+<svg xmlns="http://www.w3.org/2000/svg" version="1.1"
+     xmlns:html="http://www.w3.org/1999/xhtml"
+     xmlns:xlink="http://www.w3.org/1999/xlink">
+  <title>Testing that foreignobject works in filters</title>
+  <foreignObject id="fo1" x="150" y="50" width="50" height="50">
+    <html:div style="width:100%; height:100%; background:lime;">
+    </html:div>
+  </foreignObject>
+  <foreignObject id="fo2" x="150" y="150" width="50" height="50" filter="url(#f1)">
+    <html:div style="width:100%; height:100%; background:lime;">
+    </html:div>
+  </foreignObject>
+  <filter id="f1" x="0" y="0" width="100%" height="100%">
+    <feOffset/>
+  </filter>
+</svg>

layout/reftests/svg/foreignObject-02.svg

@@ -0,0 +1,31 @@
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/licenses/publicdomain/
+-->
+<svg xmlns="http://www.w3.org/2000/svg" version="1.1"
+     xmlns:html="http://www.w3.org/1999/xhtml"
+     xmlns:xlink="http://www.w3.org/1999/xlink" onload="m();">
+  <title>Testing that foreignobject works in filters</title>
+  <foreignObject id="fo1" x="50" y="50" width="50" height="50">
+    <html:div style="width:100%; height:100%; background:lime;">
+    </html:div>
+  </foreignObject>
+  <foreignObject id="fo2" x="50" y="150" width="50" height="50" filter="url(#f1)">
+    <html:div style="width:100%; height:100%; background:lime;">
+    </html:div>
+  </foreignObject>
+  <filter id="f1" x="0" y="0" width="100%" height="100%">
+    <feOffset/>
+  </filter>
+  <script>
+		function m() {
+		var svgns = "http://www.w3.org/2000/svg";
+
+		var fo1 = document.getElementById("fo1");
+		fo1.setAttribute("x", "150");
+
+		var fo2 = document.getElementById("fo2");
+		fo2.setAttribute("x", "150");
+		}
+  </script>
+</svg>

layout/reftests/svg/reftest.list

@@ -54,6 +54,7 @@ include moz-only/reftest.list
 == filter-foreignObject-01.svg pass.svg
 == filter-translated-01.svg filter-translated-01-ref.svg
 == foreignObject-01.svg pass.svg
+== foreignObject-02.svg foreignObject-02-ref.svg
 == foreignObject-ancestor-style-change-01.svg foreignObject-ancestor-style-change-01-ref.svg
 == foreignObject-change-transform-01.svg pass.svg
 == foreignObject-display-01.svg pass.svg

layout/svg/base/src/nsSVGForeignObjectFrame.cpp

@@ -265,6 +265,18 @@ nsSVGForeignObjectFrame::PaintSVG(nsSVGRenderState *aContext,
     return NS_ERROR_FAILURE;
   }
 
+  /* Check if we need to draw anything. */
+  if (aDirtyRect) {
+    gfxRect extent = matrix.TransformBounds(
+                       gfxRect(kid->GetRect().x, kid->GetRect().y, 
+                               kid->GetRect().width, kid->GetRect().height));
+    extent.RoundOut();
+    nsIntRect rect;
+    if (NS_SUCCEEDED(nsSVGUtils::GfxRectToIntRect(extent, &rect)) &&
+        !aDirtyRect->Intersects(rect))
+      return NS_OK;
+  }
+
   gfxContext *gfx = aContext->GetGfxContext();
 
   gfx->Save();