diff --git a/content/svg/content/src/SVGAnimatedPreserveAspectRatio.cpp b/content/svg/content/src/SVGAnimatedPreserveAspectRatio.cpp
index 429de200e13..73d88b9de0c 100644
--- a/content/svg/content/src/SVGAnimatedPreserveAspectRatio.cpp
+++ b/content/svg/content/src/SVGAnimatedPreserveAspectRatio.cpp
@@ -392,9 +392,9 @@ void
 SMILPreserveAspectRatio::ClearAnimValue()
 {
   if (mVal->mIsAnimated) {
-    mVal->SetAnimValue(PackPreserveAspectRatio(mVal->GetBaseValue()),
-                       mSVGElement);
     mVal->mIsAnimated = false;
+    mVal->mAnimVal = mVal->mBaseVal;
+    mSVGElement->DidAnimatePreserveAspectRatio();
   }
 }
 
diff --git a/content/svg/content/src/nsSVGAngle.cpp b/content/svg/content/src/nsSVGAngle.cpp
index 68979970836..364d96661ea 100644
--- a/content/svg/content/src/nsSVGAngle.cpp
+++ b/content/svg/content/src/nsSVGAngle.cpp
@@ -510,8 +510,10 @@ nsSVGAngle::SMILOrient::ClearAnimValue()
 {
   if (mAngle->mIsAnimated) {
     mOrientType->SetAnimValue(mOrientType->GetBaseValue());
-    mAngle->SetAnimValue(mAngle->mBaseVal, mAngle->mBaseValUnit, mSVGElement);
     mAngle->mIsAnimated = false;
+    mAngle->mAnimVal = mAngle->mBaseVal;
+    mAngle->mAnimValUnit = mAngle->mBaseValUnit;
+    mSVGElement->DidAnimateAngle(mAngle->mAttrEnum);
   }
 }
 
diff --git a/content/svg/content/src/nsSVGBoolean.cpp b/content/svg/content/src/nsSVGBoolean.cpp
index c31fca96e4d..1c65694c319 100644
--- a/content/svg/content/src/nsSVGBoolean.cpp
+++ b/content/svg/content/src/nsSVGBoolean.cpp
@@ -190,8 +190,9 @@ void
 nsSVGBoolean::SMILBool::ClearAnimValue()
 {
   if (mVal->mIsAnimated) {
-    mVal->SetAnimValue(mVal->mBaseVal, mSVGElement);
     mVal->mIsAnimated = false;
+    mVal->mAnimVal = mVal->mBaseVal;
+    mSVGElement->DidAnimateBoolean(mVal->mAttrEnum);
   }
 }
 
diff --git a/content/svg/content/src/nsSVGCircleElement.cpp b/content/svg/content/src/nsSVGCircleElement.cpp
index ddb9ec62d64..e194c77d5e6 100644
--- a/content/svg/content/src/nsSVGCircleElement.cpp
+++ b/content/svg/content/src/nsSVGCircleElement.cpp
@@ -67,6 +67,9 @@ public:
   NS_FORWARD_NSIDOMELEMENT(nsSVGCircleElementBase::)
   NS_FORWARD_NSIDOMSVGELEMENT(nsSVGCircleElementBase::)
 
+  // nsSVGSVGElement methods:
+  virtual bool HasValidDimensions() const;
+
   // nsSVGPathGeometryElement methods:
   virtual void ConstructPath(gfxContext *aCtx);
 
@@ -143,6 +146,13 @@ NS_IMETHODIMP nsSVGCircleElement::GetR(nsIDOMSVGAnimatedLength * *aR)
 //----------------------------------------------------------------------
 // nsSVGElement methods
 
+/* virtual */ bool
+nsSVGCircleElement::HasValidDimensions() const
+{
+  return mLengthAttributes[R].IsExplicitlySet() &&
+         mLengthAttributes[R].GetAnimValInSpecifiedUnits() > 0;
+}
+
 nsSVGElement::LengthAttributesInfo
 nsSVGCircleElement::GetLengthInfo()
 {
diff --git a/content/svg/content/src/nsSVGElement.h b/content/svg/content/src/nsSVGElement.h
index 680cbe71191..90989fefb55 100644
--- a/content/svg/content/src/nsSVGElement.h
+++ b/content/svg/content/src/nsSVGElement.h
@@ -195,6 +195,9 @@ public:
   bool NumberAttrAllowsPercentage(PRUint8 aAttrEnum) {
     return GetNumberInfo().mNumberInfo[aAttrEnum].mPercentagesAllowed;
   }
+  virtual bool HasValidDimensions() const {
+    return true;
+  }
   void SetLength(nsIAtom* aName, const nsSVGLength2 &aLength);
 
   nsAttrValue WillChangeLength(PRUint8 aAttrEnum);
diff --git a/content/svg/content/src/nsSVGEllipseElement.cpp b/content/svg/content/src/nsSVGEllipseElement.cpp
index 5183018da93..8bbabaaa011 100644
--- a/content/svg/content/src/nsSVGEllipseElement.cpp
+++ b/content/svg/content/src/nsSVGEllipseElement.cpp
@@ -68,6 +68,9 @@ public:
   NS_FORWARD_NSIDOMELEMENT(nsSVGEllipseElementBase::)
   NS_FORWARD_NSIDOMSVGELEMENT(nsSVGEllipseElementBase::)
 
+  // nsSVGSVGElement methods:
+  virtual bool HasValidDimensions() const;
+
   // nsSVGPathGeometryElement methods:
   virtual void ConstructPath(gfxContext *aCtx);
 
@@ -151,6 +154,15 @@ NS_IMETHODIMP nsSVGEllipseElement::GetRy(nsIDOMSVGAnimatedLength * *aRy)
 //----------------------------------------------------------------------
 // nsSVGElement methods
 
+/* virtual */ bool
+nsSVGEllipseElement::HasValidDimensions() const
+{
+  return mLengthAttributes[RX].IsExplicitlySet() &&
+         mLengthAttributes[RX].GetAnimValInSpecifiedUnits() > 0 &&
+         mLengthAttributes[RY].IsExplicitlySet() &&
+         mLengthAttributes[RY].GetAnimValInSpecifiedUnits() > 0;
+}
+
 nsSVGElement::LengthAttributesInfo
 nsSVGEllipseElement::GetLengthInfo()
 {
diff --git a/content/svg/content/src/nsSVGEnum.cpp b/content/svg/content/src/nsSVGEnum.cpp
index 3e5e5317dc6..a97167cc194 100644
--- a/content/svg/content/src/nsSVGEnum.cpp
+++ b/content/svg/content/src/nsSVGEnum.cpp
@@ -200,8 +200,9 @@ void
 nsSVGEnum::SMILEnum::ClearAnimValue()
 {
   if (mVal->mIsAnimated) {
-    mVal->SetAnimValue(mVal->mBaseVal, mSVGElement);
     mVal->mIsAnimated = false;
+    mVal->mAnimVal = mVal->mBaseVal;
+    mSVGElement->DidAnimateEnum(mVal->mAttrEnum);
   }
 }
 
diff --git a/content/svg/content/src/nsSVGFilterElement.cpp b/content/svg/content/src/nsSVGFilterElement.cpp
index 4c5ecff987a..fd96286554d 100644
--- a/content/svg/content/src/nsSVGFilterElement.cpp
+++ b/content/svg/content/src/nsSVGFilterElement.cpp
@@ -219,6 +219,15 @@ nsSVGFilterElement::Invalidate()
 //----------------------------------------------------------------------
 // nsSVGElement methods
 
+/* virtual */ bool
+nsSVGFilterElement::HasValidDimensions() const
+{
+  return (!mLengthAttributes[WIDTH].IsExplicitlySet() ||
+           mLengthAttributes[WIDTH].GetAnimValInSpecifiedUnits() > 0) &&
+         (!mLengthAttributes[HEIGHT].IsExplicitlySet() || 
+           mLengthAttributes[HEIGHT].GetAnimValInSpecifiedUnits() > 0);
+}
+
 nsSVGElement::LengthAttributesInfo
 nsSVGFilterElement::GetLengthInfo()
 {
diff --git a/content/svg/content/src/nsSVGFilterElement.h b/content/svg/content/src/nsSVGFilterElement.h
index 4d7f3018389..c761a3ca6d3 100644
--- a/content/svg/content/src/nsSVGFilterElement.h
+++ b/content/svg/content/src/nsSVGFilterElement.h
@@ -83,6 +83,9 @@ public:
   void Invalidate();
 
   virtual nsXPCClassInfo* GetClassInfo();
+
+  // nsSVGSVGElement methods:
+  virtual bool HasValidDimensions() const;
 protected:
 
   virtual LengthAttributesInfo GetLengthInfo();
diff --git a/content/svg/content/src/nsSVGFilters.cpp b/content/svg/content/src/nsSVGFilters.cpp
index c5d3ec86422..624be8b8da7 100644
--- a/content/svg/content/src/nsSVGFilters.cpp
+++ b/content/svg/content/src/nsSVGFilters.cpp
@@ -310,6 +310,15 @@ nsSVGFE::IsAttributeMapped(const nsIAtom* name) const
 //----------------------------------------------------------------------
 // nsSVGElement methods
 
+/* virtual */ bool
+nsSVGFE::HasValidDimensions() const
+{
+  return (!mLengthAttributes[WIDTH].IsExplicitlySet() ||
+           mLengthAttributes[WIDTH].GetAnimValInSpecifiedUnits() > 0) &&
+         (!mLengthAttributes[HEIGHT].IsExplicitlySet() || 
+           mLengthAttributes[HEIGHT].GetAnimValInSpecifiedUnits() > 0);
+}
+
 nsSVGElement::LengthAttributesInfo
 nsSVGFE::GetLengthInfo()
 {
diff --git a/content/svg/content/src/nsSVGFilters.h b/content/svg/content/src/nsSVGFilters.h
index 3f5a7b1536d..a433d89a6f6 100644
--- a/content/svg/content/src/nsSVGFilters.h
+++ b/content/svg/content/src/nsSVGFilters.h
@@ -158,6 +158,9 @@ public:
   // nsIContent interface
   NS_IMETHOD_(bool) IsAttributeMapped(const nsIAtom* aAttribute) const;
 
+  // nsSVGElement interface
+  virtual bool HasValidDimensions() const;
+
   virtual nsSVGString& GetResultImageName() = 0;
   // Return a list of all image names used as sources. Default is to
   // return no sources.
diff --git a/content/svg/content/src/nsSVGForeignObjectElement.cpp b/content/svg/content/src/nsSVGForeignObjectElement.cpp
index 4385a4a2830..c78b30ddf33 100644
--- a/content/svg/content/src/nsSVGForeignObjectElement.cpp
+++ b/content/svg/content/src/nsSVGForeignObjectElement.cpp
@@ -136,6 +136,15 @@ nsSVGForeignObjectElement::PrependLocalTransformsTo(const gfxMatrix &aMatrix,
   return toUserSpace * fromUserSpace;
 }
 
+/* virtual */ bool
+nsSVGForeignObjectElement::HasValidDimensions() const
+{
+  return mLengthAttributes[WIDTH].IsExplicitlySet() &&
+         mLengthAttributes[WIDTH].GetAnimValInSpecifiedUnits() > 0 &&
+         mLengthAttributes[HEIGHT].IsExplicitlySet() &&
+         mLengthAttributes[HEIGHT].GetAnimValInSpecifiedUnits() > 0;
+}
+
 //----------------------------------------------------------------------
 // nsIContent methods
 
diff --git a/content/svg/content/src/nsSVGForeignObjectElement.h b/content/svg/content/src/nsSVGForeignObjectElement.h
index d9794dbeffe..c18ca6575e7 100644
--- a/content/svg/content/src/nsSVGForeignObjectElement.h
+++ b/content/svg/content/src/nsSVGForeignObjectElement.h
@@ -71,6 +71,7 @@ public:
   // nsSVGElement specializations:
   virtual gfxMatrix PrependLocalTransformsTo(const gfxMatrix &aMatrix,
                       TransformTypes aWhich = eAllTransforms) const;
+  virtual bool HasValidDimensions() const;
 
   // nsIContent interface
   NS_IMETHOD_(bool) IsAttributeMapped(const nsIAtom* name) const;
diff --git a/content/svg/content/src/nsSVGImageElement.cpp b/content/svg/content/src/nsSVGImageElement.cpp
index b5582e41730..beaa47176ca 100644
--- a/content/svg/content/src/nsSVGImageElement.cpp
+++ b/content/svg/content/src/nsSVGImageElement.cpp
@@ -267,6 +267,15 @@ nsSVGImageElement::ConstructPath(gfxContext *aCtx)
 //----------------------------------------------------------------------
 // nsSVGElement methods
 
+/* virtual */ bool
+nsSVGImageElement::HasValidDimensions() const
+{
+  return mLengthAttributes[WIDTH].IsExplicitlySet() &&
+         mLengthAttributes[WIDTH].GetAnimValInSpecifiedUnits() > 0 &&
+         mLengthAttributes[HEIGHT].IsExplicitlySet() &&
+         mLengthAttributes[HEIGHT].GetAnimValInSpecifiedUnits() > 0;
+}
+
 nsSVGElement::LengthAttributesInfo
 nsSVGImageElement::GetLengthInfo()
 {
diff --git a/content/svg/content/src/nsSVGImageElement.h b/content/svg/content/src/nsSVGImageElement.h
index 663c9ac2e84..8aea8028775 100644
--- a/content/svg/content/src/nsSVGImageElement.h
+++ b/content/svg/content/src/nsSVGImageElement.h
@@ -90,6 +90,9 @@ public:
   // nsSVGPathGeometryElement methods:
   virtual void ConstructPath(gfxContext *aCtx);
 
+  // nsSVGSVGElement methods:
+  virtual bool HasValidDimensions() const;
+
   virtual nsresult Clone(nsINodeInfo *aNodeInfo, nsINode **aResult) const;
 
   nsresult CopyInnerTo(nsGenericElement* aDest) const;
diff --git a/content/svg/content/src/nsSVGInteger.cpp b/content/svg/content/src/nsSVGInteger.cpp
index 8a1f06dbb0d..c02165462c2 100644
--- a/content/svg/content/src/nsSVGInteger.cpp
+++ b/content/svg/content/src/nsSVGInteger.cpp
@@ -185,8 +185,9 @@ void
 nsSVGInteger::SMILInteger::ClearAnimValue()
 {
   if (mVal->mIsAnimated) {
-    mVal->SetAnimValue(mVal->mBaseVal, mSVGElement);
     mVal->mIsAnimated = false;
+    mVal->mAnimVal = mVal->mBaseVal;
+    mSVGElement->DidAnimateInteger(mVal->mAttrEnum);
   }
 }
 
diff --git a/content/svg/content/src/nsSVGIntegerPair.cpp b/content/svg/content/src/nsSVGIntegerPair.cpp
index dc35ada0e4e..f9417c61d0a 100644
--- a/content/svg/content/src/nsSVGIntegerPair.cpp
+++ b/content/svg/content/src/nsSVGIntegerPair.cpp
@@ -241,8 +241,10 @@ void
 nsSVGIntegerPair::SMILIntegerPair::ClearAnimValue()
 {
   if (mVal->mIsAnimated) {
-    mVal->SetAnimValue(mVal->mBaseVal, mSVGElement);
     mVal->mIsAnimated = false;
+    mVal->mAnimVal[0] = mVal->mBaseVal[0];
+    mVal->mAnimVal[1] = mVal->mBaseVal[1];
+    mSVGElement->DidAnimateIntegerPair(mVal->mAttrEnum);
   }
 }
 
diff --git a/content/svg/content/src/nsSVGLength2.cpp b/content/svg/content/src/nsSVGLength2.cpp
index 40301209dc0..da3c15465cc 100644
--- a/content/svg/content/src/nsSVGLength2.cpp
+++ b/content/svg/content/src/nsSVGLength2.cpp
@@ -570,8 +570,9 @@ void
 nsSVGLength2::SMILLength::ClearAnimValue()
 {
   if (mVal->mIsAnimated) {
-    mVal->SetAnimValueInSpecifiedUnits(mVal->mBaseVal, mSVGElement);
     mVal->mIsAnimated = false;
+    mVal->mAnimVal = mVal->mBaseVal;
+    mSVGElement->DidAnimateLength(mVal->mAttrEnum);
   }  
 }
 
diff --git a/content/svg/content/src/nsSVGMarkerElement.cpp b/content/svg/content/src/nsSVGMarkerElement.cpp
index 91c6e2950fc..e82830f7625 100644
--- a/content/svg/content/src/nsSVGMarkerElement.cpp
+++ b/content/svg/content/src/nsSVGMarkerElement.cpp
@@ -306,6 +306,15 @@ nsSVGMarkerElement::SetParentCoordCtxProvider(nsSVGSVGElement *aContext)
   mViewBoxToViewportTransform = nsnull;
 }
 
+/* virtual */ bool
+nsSVGMarkerElement::HasValidDimensions() const
+{
+  return (!mLengthAttributes[MARKERWIDTH].IsExplicitlySet() ||
+           mLengthAttributes[MARKERWIDTH].GetAnimValInSpecifiedUnits() > 0) &&
+         (!mLengthAttributes[MARKERHEIGHT].IsExplicitlySet() || 
+           mLengthAttributes[MARKERHEIGHT].GetAnimValInSpecifiedUnits() > 0);
+}
+
 nsSVGElement::LengthAttributesInfo
 nsSVGMarkerElement::GetLengthInfo()
 {
diff --git a/content/svg/content/src/nsSVGMarkerElement.h b/content/svg/content/src/nsSVGMarkerElement.h
index 8f53d281c0e..bbb930246df 100644
--- a/content/svg/content/src/nsSVGMarkerElement.h
+++ b/content/svg/content/src/nsSVGMarkerElement.h
@@ -133,6 +133,9 @@ public:
   virtual nsresult UnsetAttr(PRInt32 aNameSpaceID, nsIAtom* aAttribute,
                              bool aNotify);
 
+  // nsSVGSVGElement methods:
+  virtual bool HasValidDimensions() const;
+
   // public helpers
   gfxMatrix GetMarkerTransform(float aStrokeWidth,
                                float aX, float aY, float aAutoAngle);
diff --git a/content/svg/content/src/nsSVGMaskElement.cpp b/content/svg/content/src/nsSVGMaskElement.cpp
index 9ab4ba223e0..83a7ff760cf 100644
--- a/content/svg/content/src/nsSVGMaskElement.cpp
+++ b/content/svg/content/src/nsSVGMaskElement.cpp
@@ -136,6 +136,15 @@ NS_IMETHODIMP nsSVGMaskElement::GetHeight(nsIDOMSVGAnimatedLength * *aHeight)
 //----------------------------------------------------------------------
 // nsSVGElement methods
 
+/* virtual */ bool
+nsSVGMaskElement::HasValidDimensions() const
+{
+  return (!mLengthAttributes[WIDTH].IsExplicitlySet() ||
+           mLengthAttributes[WIDTH].GetAnimValInSpecifiedUnits() > 0) &&
+         (!mLengthAttributes[HEIGHT].IsExplicitlySet() || 
+           mLengthAttributes[HEIGHT].GetAnimValInSpecifiedUnits() > 0);
+}
+
 nsSVGElement::LengthAttributesInfo
 nsSVGMaskElement::GetLengthInfo()
 {
diff --git a/content/svg/content/src/nsSVGMaskElement.h b/content/svg/content/src/nsSVGMaskElement.h
index 7e286c3b98c..a21a02db143 100644
--- a/content/svg/content/src/nsSVGMaskElement.h
+++ b/content/svg/content/src/nsSVGMaskElement.h
@@ -76,6 +76,9 @@ public:
   NS_IMETHOD_(bool) IsAttributeMapped(const nsIAtom* aAttribute) const;
 
   virtual nsXPCClassInfo* GetClassInfo();
+
+  // nsSVGSVGElement methods:
+  virtual bool HasValidDimensions() const;
 protected:
 
   virtual LengthAttributesInfo GetLengthInfo();
diff --git a/content/svg/content/src/nsSVGNumber2.cpp b/content/svg/content/src/nsSVGNumber2.cpp
index 9cc4d64632a..48792f60c5a 100644
--- a/content/svg/content/src/nsSVGNumber2.cpp
+++ b/content/svg/content/src/nsSVGNumber2.cpp
@@ -227,8 +227,9 @@ void
 nsSVGNumber2::SMILNumber::ClearAnimValue()
 {
   if (mVal->mIsAnimated) {
-    mVal->SetAnimValue(mVal->mBaseVal, mSVGElement);
     mVal->mIsAnimated = false;
+    mVal->mAnimVal = mVal->mBaseVal;
+    mSVGElement->DidAnimateNumber(mVal->mAttrEnum);
   }
 }
 
diff --git a/content/svg/content/src/nsSVGNumberPair.cpp b/content/svg/content/src/nsSVGNumberPair.cpp
index 825704e0476..891c3450724 100644
--- a/content/svg/content/src/nsSVGNumberPair.cpp
+++ b/content/svg/content/src/nsSVGNumberPair.cpp
@@ -239,8 +239,10 @@ void
 nsSVGNumberPair::SMILNumberPair::ClearAnimValue()
 {
   if (mVal->mIsAnimated) {
-    mVal->SetAnimValue(mVal->mBaseVal, mSVGElement);
     mVal->mIsAnimated = false;
+    mVal->mAnimVal[0] = mVal->mBaseVal[0];
+    mVal->mAnimVal[1] = mVal->mBaseVal[1];
+    mSVGElement->DidAnimateNumberPair(mVal->mAttrEnum);
   }
 }
 
diff --git a/content/svg/content/src/nsSVGPatternElement.cpp b/content/svg/content/src/nsSVGPatternElement.cpp
index 658ee0de730..23267a43727 100644
--- a/content/svg/content/src/nsSVGPatternElement.cpp
+++ b/content/svg/content/src/nsSVGPatternElement.cpp
@@ -214,6 +214,15 @@ nsSVGPatternElement::GetAnimatedTransformList()
   return mPatternTransform;
 }
 
+/* virtual */ bool
+nsSVGPatternElement::HasValidDimensions() const
+{
+  return mLengthAttributes[WIDTH].IsExplicitlySet() &&
+         mLengthAttributes[WIDTH].GetAnimValInSpecifiedUnits() > 0 &&
+         mLengthAttributes[HEIGHT].IsExplicitlySet() &&
+         mLengthAttributes[HEIGHT].GetAnimValInSpecifiedUnits() > 0;
+}
+
 nsSVGElement::LengthAttributesInfo
 nsSVGPatternElement::GetLengthInfo()
 {
diff --git a/content/svg/content/src/nsSVGPatternElement.h b/content/svg/content/src/nsSVGPatternElement.h
index 59fbff8a0ce..f0fe6dcf57a 100644
--- a/content/svg/content/src/nsSVGPatternElement.h
+++ b/content/svg/content/src/nsSVGPatternElement.h
@@ -96,6 +96,9 @@ public:
 
   virtual nsXPCClassInfo* GetClassInfo();
 
+  // nsSVGSVGElement methods:
+  virtual bool HasValidDimensions() const;
+
   virtual mozilla::SVGAnimatedTransformList* GetAnimatedTransformList();
   virtual nsIAtom* GetTransformListAttrName() const {
     return nsGkAtoms::patternTransform;
diff --git a/content/svg/content/src/nsSVGRectElement.cpp b/content/svg/content/src/nsSVGRectElement.cpp
index 6494ef6f504..b392e562b9e 100644
--- a/content/svg/content/src/nsSVGRectElement.cpp
+++ b/content/svg/content/src/nsSVGRectElement.cpp
@@ -67,6 +67,9 @@ public:
   NS_FORWARD_NSIDOMELEMENT(nsSVGRectElementBase::)
   NS_FORWARD_NSIDOMSVGELEMENT(nsSVGRectElementBase::)
 
+  // nsSVGSVGElement methods:
+  virtual bool HasValidDimensions() const;
+
   // nsSVGPathGeometryElement methods:
   virtual void ConstructPath(gfxContext *aCtx);
 
@@ -164,6 +167,15 @@ NS_IMETHODIMP nsSVGRectElement::GetRy(nsIDOMSVGAnimatedLength * *aRy)
 //----------------------------------------------------------------------
 // nsSVGElement methods
 
+/* virtual */ bool
+nsSVGRectElement::HasValidDimensions() const
+{
+  return mLengthAttributes[WIDTH].IsExplicitlySet() &&
+         mLengthAttributes[WIDTH].GetAnimValInSpecifiedUnits() > 0 &&
+         mLengthAttributes[HEIGHT].IsExplicitlySet() &&
+         mLengthAttributes[HEIGHT].GetAnimValInSpecifiedUnits() > 0;
+}
+
 nsSVGElement::LengthAttributesInfo
 nsSVGRectElement::GetLengthInfo()
 {
diff --git a/content/svg/content/src/nsSVGSVGElement.cpp b/content/svg/content/src/nsSVGSVGElement.cpp
index eed270768a6..f038085a7b0 100644
--- a/content/svg/content/src/nsSVGSVGElement.cpp
+++ b/content/svg/content/src/nsSVGSVGElement.cpp
@@ -1189,6 +1189,16 @@ nsSVGSVGElement::GetLength(PRUint8 aCtxType)
   return 0;
 }
 
+void
+nsSVGSVGElement::SyncWidthOrHeight(nsIAtom* aName, nsSVGElement *aTarget) const
+{
+  NS_ASSERTION(aName == nsGkAtoms::width || aName == nsGkAtoms::height,
+               "The clue is in the function name");
+
+  PRUint32 index = *sLengthInfo[WIDTH].mName == aName ? WIDTH : HEIGHT;
+  aTarget->SetLength(aName, mLengthAttributes[index]);
+}
+
 //----------------------------------------------------------------------
 // nsSVGElement methods
 
@@ -1229,6 +1239,16 @@ nsSVGSVGElement::PrependLocalTransformsTo(const gfxMatrix &aMatrix,
   return GetViewBoxTransform() * aMatrix;
 }
 
+/* virtual */ bool
+nsSVGSVGElement::HasValidDimensions() const
+{
+  return !IsInner() ||
+    ((!mLengthAttributes[WIDTH].IsExplicitlySet() ||
+       mLengthAttributes[WIDTH].GetAnimValInSpecifiedUnits() > 0) &&
+     (!mLengthAttributes[HEIGHT].IsExplicitlySet() || 
+       mLengthAttributes[HEIGHT].GetAnimValInSpecifiedUnits() > 0));
+}
+
 nsSVGElement::LengthAttributesInfo
 nsSVGSVGElement::GetLengthInfo()
 {
diff --git a/content/svg/content/src/nsSVGSVGElement.h b/content/svg/content/src/nsSVGSVGElement.h
index 668de43e533..c4cb02cc0ac 100644
--- a/content/svg/content/src/nsSVGSVGElement.h
+++ b/content/svg/content/src/nsSVGSVGElement.h
@@ -188,9 +188,12 @@ public:
   // nsSVGElement specializations:
   virtual gfxMatrix PrependLocalTransformsTo(const gfxMatrix &aMatrix,
                       TransformTypes aWhich = eAllTransforms) const;
+  virtual bool HasValidDimensions() const;
  
   // nsSVGSVGElement methods:
   float GetLength(PRUint8 mCtxType);
+  // Copy our width or height to the target
+  void SyncWidthOrHeight(nsIAtom* aName, nsSVGElement *aTarget) const;
 
   // public helpers:
   gfxMatrix GetViewBoxTransform() const;
diff --git a/content/svg/content/src/nsSVGUseElement.cpp b/content/svg/content/src/nsSVGUseElement.cpp
index 458b8cc6124..e34524ecba4 100644
--- a/content/svg/content/src/nsSVGUseElement.cpp
+++ b/content/svg/content/src/nsSVGUseElement.cpp
@@ -40,7 +40,7 @@
 #include "nsIDOMSVGGElement.h"
 #include "nsGkAtoms.h"
 #include "nsIDOMDocument.h"
-#include "nsIDOMSVGSVGElement.h"
+#include "nsSVGSVGElement.h"
 #include "nsIDOMSVGSymbolElement.h"
 #include "nsIDocument.h"
 #include "nsIPresShell.h"
@@ -288,10 +288,6 @@ nsSVGUseElement::CreateAnonymousContent()
       tag != nsGkAtoms::use)
     return nsnull;
 
-  // Make sure the use attributes are valid
-  if (!HasValidDimensions())
-    return nsnull;
-
   // circular loop detection
 
   // check 1 - check if we're a document descendent of the target
@@ -299,8 +295,8 @@ nsSVGUseElement::CreateAnonymousContent()
     return nsnull;
 
   // check 2 - check if we're a clone, and if we already exist in the hierarchy
-  if (this->GetParent() && mOriginal) {
-    for (nsCOMPtr<nsIContent> content = this->GetParent();
+  if (GetParent() && mOriginal) {
+    for (nsCOMPtr<nsIContent> content = GetParent();
          content;
          content = content->GetParent()) {
       nsCOMPtr<nsIDOMSVGUseElement> useElement = do_QueryInterface(content);
@@ -407,43 +403,43 @@ nsSVGUseElement::DestroyAnonymousContent()
 //----------------------------------------------------------------------
 // implementation helpers
 
-bool nsSVGUseElement::HasValidDimensions()
-{
-  nsSVGSVGElement *ctx = GetCtx();
-
-  return (!mLengthAttributes[WIDTH].IsExplicitlySet() ||
-           mLengthAttributes[WIDTH].GetAnimValue(ctx) > 0) &&
-         (!mLengthAttributes[HEIGHT].IsExplicitlySet() || 
-           mLengthAttributes[HEIGHT].GetAnimValue(ctx) > 0);
-}
-
 void
-nsSVGUseElement::SyncWidthHeight(nsIAtom* aName)
+nsSVGUseElement::SyncWidthOrHeight(nsIAtom* aName)
 {
   NS_ASSERTION(aName == nsGkAtoms::width || aName == nsGkAtoms::height,
                "The clue is in the function name");
 
-  if (HasValidDimensions() == !mClone) {
-    TriggerReclone();
+  if (!mClone) {
     return;
   }
 
-  if (mClone) {
-    nsCOMPtr<nsIDOMSVGSymbolElement> symbol = do_QueryInterface(mClone);
-    nsCOMPtr<nsIDOMSVGSVGElement>    svg    = do_QueryInterface(mClone);
+  nsCOMPtr<nsIDOMSVGSymbolElement> symbol = do_QueryInterface(mClone);
+  nsCOMPtr<nsIDOMSVGSVGElement>    svg    = do_QueryInterface(mClone);
 
-    if (symbol || svg) {
-      PRUint32 index = *sLengthInfo[WIDTH].mName == aName ? WIDTH : HEIGHT;
-      if (mLengthAttributes[index].IsExplicitlySet()) {
-        static_cast<nsSVGElement*>(mClone.get())->
-          SetLength(aName, mLengthAttributes[index]);
-      } else {
-        // Our width/height attribute is now no longer explicitly set, so we
-        // need to revert the clone's width/height to the width/height of the
-        // content that's being cloned.
-        TriggerReclone();
-      }
+  if (symbol || svg) {
+    nsSVGElement *target = static_cast<nsSVGElement*>(mClone.get());
+    PRUint32 index = *sLengthInfo[WIDTH].mName == aName ? WIDTH : HEIGHT;
+
+    if (mLengthAttributes[index].IsExplicitlySet()) {
+      target->SetLength(aName, mLengthAttributes[index]);
+      return;
     }
+    if (svg) {
+      // Our width/height attribute is now no longer explicitly set, so we
+      // need to revert the clone's width/height to the width/height of the
+      // content that's being cloned.
+      nsSVGSVGElement* svgElement =
+        static_cast<nsSVGSVGElement*>(mSource.get());
+      svgElement->SyncWidthOrHeight(aName, target);
+      return;
+    }
+    // Our width/height attribute is now no longer explicitly set, so we
+    // need to set the value to 100%
+    nsSVGLength2 length;
+    length.Init(nsSVGUtils::XY, 0xff,
+                100, nsIDOMSVGLength::SVG_LENGTHTYPE_PERCENTAGE);
+    target->SetLength(aName, length);
+    return;
   }
 }
 
@@ -511,6 +507,15 @@ nsSVGUseElement::PrependLocalTransformsTo(const gfxMatrix &aMatrix,
   return toUserSpace * fromUserSpace;
 }
 
+/* virtual */ bool
+nsSVGUseElement::HasValidDimensions() const
+{
+  return (!mLengthAttributes[WIDTH].IsExplicitlySet() ||
+           mLengthAttributes[WIDTH].GetAnimValInSpecifiedUnits() > 0) &&
+         (!mLengthAttributes[HEIGHT].IsExplicitlySet() || 
+           mLengthAttributes[HEIGHT].GetAnimValInSpecifiedUnits() > 0);
+}
+
 nsSVGElement::LengthAttributesInfo
 nsSVGUseElement::GetLengthInfo()
 {
diff --git a/content/svg/content/src/nsSVGUseElement.h b/content/svg/content/src/nsSVGUseElement.h
index f9f4d43df13..dcc05e7d041 100644
--- a/content/svg/content/src/nsSVGUseElement.h
+++ b/content/svg/content/src/nsSVGUseElement.h
@@ -105,6 +105,7 @@ public:
   // nsSVGElement specializations:
   virtual gfxMatrix PrependLocalTransformsTo(const gfxMatrix &aMatrix,
                       TransformTypes aWhich = eAllTransforms) const;
+  virtual bool HasValidDimensions() const;
 
   // nsIContent interface
   virtual nsresult Clone(nsINodeInfo *aNodeInfo, nsINode **aResult) const;
@@ -130,8 +131,7 @@ protected:
   virtual LengthAttributesInfo GetLengthInfo();
   virtual StringAttributesInfo GetStringInfo();
 
-  bool HasValidDimensions();
-  void SyncWidthHeight(nsIAtom *aName);
+  void SyncWidthOrHeight(nsIAtom *aName);
   void LookupHref();
   void TriggerReclone();
   void UnlinkSource();
diff --git a/layout/reftests/svg/rect-04.svg b/layout/reftests/svg/rect-04.svg
new file mode 100644
index 00000000000..bac509417b8
--- /dev/null
+++ b/layout/reftests/svg/rect-04.svg
@@ -0,0 +1,18 @@
+<svg xmlns="http://www.w3.org/2000/svg"
+     xmlns:xlink="http://www.w3.org/1999/xlink">
+  <title>Test that a rect with no width/height does not display even with a filter</title>
+
+  <rect width="100%" height="100%" fill="lime"/>
+
+  <filter id="filter" filterUnits="userSpaceOnUse"
+          x="0" y="0" width="100%" height="100%">
+    <!-- data: URI is a 1x1 red GIF -->
+    <feImage preserveAspectRatio="xMidYMid slice"
+             style="image-rendering: optimizeSpeed;"
+             xlink:href="data:image/gif,GIF87a%01%00%01%00%80%01%00%FF%00%00%FF%FF%FF%2C%00%00%00%00%01%00%01%00%00%02%02D%01%00%3B">
+    </feImage>
+  </filter>
+
+  <rect filter="url(#filter)"/>
+
+</svg>
diff --git a/layout/reftests/svg/reftest.list b/layout/reftests/svg/reftest.list
index e33ce513a8a..867d7c09ca8 100644
--- a/layout/reftests/svg/reftest.list
+++ b/layout/reftests/svg/reftest.list
@@ -215,6 +215,7 @@ random-if(gtk2Widget) == objectBoundingBox-and-fePointLight-02.svg objectBoundin
 == rect-01.svg pass.svg
 == rect-02.svg pass.svg
 == rect-03.svg pass.svg
+== rect-04.svg pass.svg
 == rect-with-rx-and-ry-01.svg pass.svg
 == rect-with-rx-or-ry-01.svg rect-with-rx-or-ry-01-ref.svg
 == rootElement-null-01.svg pass.svg
diff --git a/layout/reftests/svg/smil/anim-feImage-preserveAspectRatio-01.svg b/layout/reftests/svg/smil/anim-feImage-preserveAspectRatio-01.svg
index 57ca1d9651b..13d3113a21f 100644
--- a/layout/reftests/svg/smil/anim-feImage-preserveAspectRatio-01.svg
+++ b/layout/reftests/svg/smil/anim-feImage-preserveAspectRatio-01.svg
@@ -26,6 +26,6 @@
   </filter>
 
   <rect width="100" height="20" fill="red"/>
-  <rect filter="url(#filter)"/>
+  <rect width="100" height="20" filter="url(#filter)"/>
 
 </svg>
diff --git a/layout/reftests/svg/smil/anim-use-length-02.svg b/layout/reftests/svg/smil/anim-use-length-02.svg
new file mode 100644
index 00000000000..a9d7390d887
--- /dev/null
+++ b/layout/reftests/svg/smil/anim-use-length-02.svg
@@ -0,0 +1,37 @@
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<svg xmlns="http://www.w3.org/2000/svg" 
+     xmlns:xlink="http://www.w3.org/1999/xlink"
+     class="reftest-wait">
+  <title>Test animation of the "width" &amp; "height" &lt;length&gt; attributes on the "use" element</title>
+  <script type="text/javascript">
+    function doTest() {
+      setTimeAndSnapshot(1, true);
+    }
+    window.addEventListener("MozReftestInvalidate", doTest, false);
+  </script>
+  <script xlink:href="smil-util.js" type="text/javascript"/>
+
+  <defs>
+    <g id="g1">
+      <rect width="100" height="50" fill="lime" />
+    </g>
+    <g id="g2">
+      <rect y="50" width="100" height="50" fill="lime" />
+    </g>
+  </defs>
+
+  <rect width="100%" height="100%" fill="lime"/>
+  <rect width="100" height="100" fill="red" />
+  <use xlink:href="#g1">
+    <set attributeName="width"
+      to="0" begin="0s" dur="0.5s"/>
+  </use>
+  <use xlink:href="#g2">
+    <set attributeName="height"
+      to="0" begin="0s" dur="0.5s"/>
+  </use>
+
+</svg>
diff --git a/layout/reftests/svg/smil/reftest.list b/layout/reftests/svg/smil/reftest.list
index b2896e4f364..a029ca4d4b8 100644
--- a/layout/reftests/svg/smil/reftest.list
+++ b/layout/reftests/svg/smil/reftest.list
@@ -95,6 +95,7 @@ fails == anim-fillcolor-1.svg      anim-standard-ref.svg # bug 436296
 == anim-length-reset-01.svg lime.svg
 == anim-nonpixel-length-reset-01.svg lime.svg
 == anim-use-length-01.svg lime.svg
+== anim-use-length-02.svg lime.svg
 
 # animate some <number> attributes:
 == anim-feComponentTransfer-01.svg lime.svg
diff --git a/layout/svg/base/src/nsSVGImageFrame.cpp b/layout/svg/base/src/nsSVGImageFrame.cpp
index b0930b26ca4..94fb8076d3d 100644
--- a/layout/svg/base/src/nsSVGImageFrame.cpp
+++ b/layout/svg/base/src/nsSVGImageFrame.cpp
@@ -320,8 +320,8 @@ nsSVGImageFrame::PaintSVG(nsSVGRenderState *aContext,
   float x, y, width, height;
   nsSVGImageElement *imgElem = static_cast<nsSVGImageElement*>(mContent);
   imgElem->GetAnimatedLengthValues(&x, &y, &width, &height, nsnull);
-  if (width <= 0 || height <= 0)
-    return NS_OK;
+  NS_ASSERTION(width >= 0 && height >= 0,
+               "Should only be painting things with valid width/height");
 
   if (!mImageContainer) {
     nsCOMPtr<imgIRequest> currentRequest;
diff --git a/layout/svg/base/src/nsSVGUseFrame.cpp b/layout/svg/base/src/nsSVGUseFrame.cpp
index 698aedd43ee..6554632c2dd 100644
--- a/layout/svg/base/src/nsSVGUseFrame.cpp
+++ b/layout/svg/base/src/nsSVGUseFrame.cpp
@@ -51,7 +51,10 @@ class nsSVGUseFrame : public nsSVGUseFrameBase,
   NS_NewSVGUseFrame(nsIPresShell* aPresShell, nsStyleContext* aContext);
 
 protected:
-  nsSVGUseFrame(nsStyleContext* aContext) : nsSVGUseFrameBase(aContext) {}
+  nsSVGUseFrame(nsStyleContext* aContext) :
+    nsSVGUseFrameBase(aContext),
+    mHasValidDimensions(true)
+  {}
 
 public:
   NS_DECL_QUERYFRAME
@@ -59,11 +62,9 @@ public:
 
   
   // nsIFrame interface:
-#ifdef DEBUG
   NS_IMETHOD Init(nsIContent*      aContent,
                   nsIFrame*        aParent,
                   nsIFrame*        aPrevInFlow);
-#endif
 
   NS_IMETHOD  AttributeChanged(PRInt32         aNameSpaceID,
                                nsIAtom*        aAttribute,
@@ -94,6 +95,9 @@ public:
   virtual nsresult CreateAnonymousContent(nsTArray<ContentInfo>& aElements);
   virtual void AppendAnonymousContentTo(nsBaseContentList& aElements,
                                         PRUint32 aFilter);
+
+private:
+  bool mHasValidDimensions;
 };
 
 //----------------------------------------------------------------------
@@ -123,18 +127,21 @@ NS_QUERYFRAME_TAIL_INHERITING(nsSVGUseFrameBase)
 //----------------------------------------------------------------------
 // nsIFrame methods:
 
-#ifdef DEBUG
 NS_IMETHODIMP
 nsSVGUseFrame::Init(nsIContent* aContent,
                     nsIFrame* aParent,
                     nsIFrame* aPrevInFlow)
 {
+#ifdef DEBUG
   nsCOMPtr<nsIDOMSVGUseElement> use = do_QueryInterface(aContent);
   NS_ASSERTION(use, "Content is not an SVG use!");
+#endif /* DEBUG */
+
+  mHasValidDimensions =
+    static_cast<nsSVGUseElement*>(aContent)->HasValidDimensions();
 
   return nsSVGUseFrameBase::Init(aContent, aParent, aPrevInFlow);
 }
-#endif /* DEBUG */
 
 NS_IMETHODIMP
 nsSVGUseFrame::AttributeChanged(PRInt32         aNameSpaceID,
@@ -150,7 +157,14 @@ nsSVGUseFrame::AttributeChanged(PRInt32         aNameSpaceID,
       nsSVGUtils::NotifyChildrenOfSVGChange(this, TRANSFORM_CHANGED);
     } else if (aAttribute == nsGkAtoms::width ||
                aAttribute == nsGkAtoms::height) {
-      static_cast<nsSVGUseElement*>(mContent)->SyncWidthHeight(aAttribute);
+      static_cast<nsSVGUseElement*>(mContent)->SyncWidthOrHeight(aAttribute);
+
+      if (mHasValidDimensions != 
+          static_cast<nsSVGUseElement*>(mContent)->HasValidDimensions()) {
+
+        mHasValidDimensions = !mHasValidDimensions;
+        nsSVGUtils::UpdateGraphic(this);
+      }
     }
   } else if (aNameSpaceID == kNameSpaceID_XLink &&
              aAttribute == nsGkAtoms::href) {
diff --git a/layout/svg/base/src/nsSVGUtils.cpp b/layout/svg/base/src/nsSVGUtils.cpp
index b2df85abe84..60dd7ead41a 100644
--- a/layout/svg/base/src/nsSVGUtils.cpp
+++ b/layout/svg/base/src/nsSVGUtils.cpp
@@ -1001,6 +1001,12 @@ nsSVGUtils::PaintFrameWithEffects(nsSVGRenderState *aContext,
   if (opacity == 0.0f)
     return;
 
+  const nsIContent* content = aFrame->GetContent();
+  if (content->IsSVG() &&
+      !static_cast<const nsSVGElement*>(content)->HasValidDimensions()) {
+    return;
+  }
+
   /* Properties are added lazily and may have been removed by a restyle,
      so make sure all applicable ones are set again. */
 
@@ -1159,9 +1165,9 @@ nsSVGUtils::HitTestChildren(nsIFrame *aFrame, const nsPoint &aPoint)
        current = current->GetPrevSibling()) {
     nsISVGChildFrame* SVGFrame = do_QueryFrame(current);
     if (SVGFrame) {
-       result = SVGFrame->GetFrameForPoint(aPoint);
-       if (result)
-         break;
+      result = SVGFrame->GetFrameForPoint(aPoint);
+      if (result)
+        break;
     }
   }
 
@@ -1393,13 +1399,18 @@ nsSVGUtils::GetBBox(nsIFrame *aFrame, PRUint32 aFlags)
       }
       svg = do_QueryFrame(aFrame);
     }
+    nsIContent* content = aFrame->GetContent();
+    if (content->IsSVG() &&
+        !static_cast<const nsSVGElement*>(content)->HasValidDimensions()) {
+      return bbox;
+    }
     gfxMatrix matrix;
     if (aFrame->GetType() == nsGkAtoms::svgForeignObjectFrame) {
       // The spec says getBBox "Returns the tight bounding box in *current user
       // space*". So we should really be doing this for all elements, but that
       // needs investigation to check that we won't break too much content.
-      NS_ABORT_IF_FALSE(aFrame->GetContent()->IsSVG(), "bad cast");
-      nsSVGElement *element = static_cast<nsSVGElement*>(aFrame->GetContent());
+      NS_ABORT_IF_FALSE(content->IsSVG(), "bad cast");
+      nsSVGElement *element = static_cast<nsSVGElement*>(content);
       matrix = element->PrependLocalTransformsTo(matrix,
                           nsSVGElement::eChildToUserSpace);
     }