Bug 647687 - Fix filter SourceImage bounds. r=longsonr

layout/reftests/svg/filter-bounds-01.svg

@@ -0,0 +1,24 @@
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<svg xmlns="http://www.w3.org/2000/svg" version="1.1"
+     xmlns:xlink="http://www.w3.org/1999/xlink">
+
+  <title>Testcase for checking that filter bounds include stroke width</title>
+
+  <!-- From https://bugzilla.mozilla.org/show_bug.cgi?id=647687 -->
+
+  <defs>
+    <filter id="f1" filterUnits="userSpaceOnUse" x="150" y="150" width="200" height="200">
+      <feOffset in="SourceGraphic"/>
+    </filter>
+  </defs>
+
+  <rect height="100%" width="100%" fill="lime"/>
+
+  <rect x="150" y="150" height="200" width="200" fill="red"/>
+
+  <rect x="200" y="200" height="100" width="100" stroke-width="100"
+            fill="none" stroke="lime" filter="url(#f1)"/>
+</svg>

layout/reftests/svg/filter-bounds-02.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" version="1.1"
+     xmlns:xlink="http://www.w3.org/1999/xlink">
+
+  <title>Testcase for checking that filter bounds include stroke width</title>
+
+  <!-- From https://bugzilla.mozilla.org/show_bug.cgi?id=647687 -->
+
+  <defs>
+    <filter id="f1" filterUnits="objectBoundingBox">
+      <feFlood flood-color="red"/>
+    </filter>
+  </defs>
+
+  <rect height="100%" width="100%" fill="lime"/>
+
+  <polygon points="200,200 300,200 300,300 200,300" stroke-width="100"
+            fill="none" stroke="lime" filter="url(#f1)"/>
+
+  <rect x="150" y="150" height="200" width="200" fill="lime"/>
+
+</svg>

layout/reftests/svg/reftest.list

@@ -111,6 +111,8 @@ random == dynamic-use-nested-01.svg dynamic-use-nested-01-ref.svg # bug 467498
 == filter-basic-01.svg pass.svg
 == filter-basic-02.svg pass.svg
 == filter-basic-03.svg pass.svg
+== filter-bounds-01.svg pass.svg
+== filter-bounds-02.svg pass.svg
 == filter-foreignObject-01.svg pass.svg
 == filter-invalidation-01.svg pass.svg
 == filter-scaled-01.svg pass.svg

layout/svg/base/src/nsSVGFilterFrame.cpp

@@ -206,11 +206,19 @@ nsAutoFilterInstance::nsAutoFilterInstance(nsIFrame *aTarget,
     MapDeviceRectToFilterSpace(deviceToFilterSpace, filterRes, aDirtyOutputRect);
   nsIntRect dirtyInputRect =
     MapDeviceRectToFilterSpace(deviceToFilterSpace, filterRes, aDirtyInputRect);
+  nsIntRect targetBoundsDeviceSpace;
+  nsISVGChildFrame* svgTarget = do_QueryFrame(aTarget);
+  if (svgTarget) {
+    targetBoundsDeviceSpace.UnionRect(targetBoundsDeviceSpace,
+      svgTarget->GetCoveredRegion().ToOutsidePixels(aTarget->PresContext()->AppUnitsPerDevPixel()));
+  }
+  nsIntRect targetBoundsFilterSpace =
+    MapDeviceRectToFilterSpace(deviceToFilterSpace, filterRes, &targetBoundsDeviceSpace);
 
   // Setup instance data
   mInstance = new nsSVGFilterInstance(aTarget, aPaint, filter, bbox, filterRegion,
                                       nsIntSize(filterRes.width, filterRes.height),
-                                      filterToDeviceSpace,
+                                      filterToDeviceSpace, targetBoundsFilterSpace,
                                       dirtyOutputRect, dirtyInputRect,
                                       primitiveUnits);
 }

layout/svg/base/src/nsSVGFilterInstance.cpp

@@ -189,6 +189,7 @@ nsSVGFilterInstance::BuildSources()
   // Detect possible float->int overflow
   if (!gfxUtils::GfxRectToIntRect(sourceBounds, &sourceBoundsInt))
     return NS_ERROR_FAILURE;
+  sourceBoundsInt.UnionRect(sourceBoundsInt, mTargetBounds);
 
   mSourceColorAlpha.mResultBoundingBox = sourceBoundsInt;
   mSourceAlpha.mResultBoundingBox = sourceBoundsInt;

layout/svg/base/src/nsSVGFilterInstance.h

@@ -70,6 +70,7 @@ public:
                       const gfxRect& aFilterRect,
                       const nsIntSize& aFilterSpaceSize,
                       const gfxMatrix &aFilterSpaceToDeviceSpaceTransform,
+                      const nsIntRect& aTargetBounds,
                       const nsIntRect& aDirtyOutputRect,
                       const nsIntRect& aDirtyInputRect,
                       PRUint16 aPrimitiveUnits) :
@@ -80,6 +81,7 @@ public:
     mFilterSpaceToDeviceSpaceTransform(aFilterSpaceToDeviceSpaceTransform),
     mFilterRect(aFilterRect),
     mFilterSpaceSize(aFilterSpaceSize),
+    mTargetBounds(aTargetBounds),
     mDirtyOutputRect(aDirtyOutputRect),
     mDirtyInputRect(aDirtyInputRect),
     mSurfaceRect(nsIntPoint(0, 0), aFilterSpaceSize),
@@ -209,6 +211,8 @@ private:
   gfxMatrix               mFilterSpaceToDeviceSpaceTransform;
   gfxRect                 mFilterRect;
   nsIntSize               mFilterSpaceSize;
+  // Filter-space bounds of the target image (SourceAlpha/SourceGraphic)
+  nsIntRect               mTargetBounds;
   nsIntRect               mDirtyOutputRect;
   nsIntRect               mDirtyInputRect;
   nsIntRect               mSurfaceRect;