Bug 866411 - copy animation effects when cloning a use element r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D188886

dom/base/Document.cpp

@@ -1393,6 +1393,7 @@ Document::Document(const char* aContentType)
       mUserHasInteracted(false),
       mHasUserInteractionTimerScheduled(false),
       mShouldResistFingerprinting(false),
+      mCloningForSVGUse(false),
       mXMLDeclarationBits(0),
       mOnloadBlockCount(0),
       mWriteLevel(0),
@@ -13668,6 +13669,9 @@ void Document::ScheduleSVGUseElementShadowTreeUpdate(
 void Document::DoUpdateSVGUseElementShadowTrees() {
   MOZ_ASSERT(!mSVGUseElementsNeedingShadowTreeUpdate.IsEmpty());
 
+  MOZ_ASSERT(!mCloningForSVGUse);
+  mCloningForSVGUse = true;
+
   do {
     const auto useElementsToUpdate = ToTArray<nsTArray<RefPtr<SVGUseElement>>>(
         mSVGUseElementsNeedingShadowTreeUpdate);
@@ -13684,6 +13688,8 @@ void Document::DoUpdateSVGUseElementShadowTrees() {
       useElement->UpdateShadowTree();
     }
   } while (!mSVGUseElementsNeedingShadowTreeUpdate.IsEmpty());
+
+  mCloningForSVGUse = false;
 }
 
 void Document::NotifyMediaFeatureValuesChanged() {

dom/base/Document.h

@@ -3688,6 +3688,9 @@ class Document : public nsINode,
   bool UserHasInteracted() { return mUserHasInteracted; }
   void ResetUserInteractionTimer();
 
+  // Whether we're cloning the contents of an SVG use element.
+  bool CloningForSVGUse() const { return mCloningForSVGUse; }
+
   // This should be called when this document receives events which are likely
   // to be user interaction with the document, rather than the byproduct of
   // interaction with the browser (i.e. a keypress to scroll the view port,
@@ -4872,6 +4875,9 @@ class Document : public nsINode,
   // Whether we should resist fingerprinting.
   bool mShouldResistFingerprinting : 1;
 
+  // Whether we're cloning the contents of an SVG use element.
+  bool mCloningForSVGUse : 1;
+
   uint8_t mXMLDeclarationBits;
 
   // NOTE(emilio): Technically, this should be a StyleColorSchemeFlags, but we

dom/svg/SVGElement.cpp

@@ -206,7 +206,8 @@ nsresult SVGElement::CopyInnerTo(mozilla::dom::Element* aDest) {
 
   // If our destination is a print document, copy all the relevant length values
   // etc so that they match the state of the original node.
-  if (aDest->OwnerDoc()->IsStaticDocument()) {
+  if (aDest->OwnerDoc()->IsStaticDocument() ||
+      aDest->OwnerDoc()->CloningForSVGUse()) {
     LengthAttributesInfo lengthInfo = GetLengthInfo();
     dest->GetLengthInfo().CopyAllFrom(lengthInfo);
     if (SVGGeometryProperty::ElementMapsLengthsToStyle(this)) {

dom/svg/SVGUseElement.cpp

@@ -94,6 +94,9 @@ namespace SVGT = SVGGeometryProperty::Tags;
 
 void SVGUseElement::ProcessAttributeChange(int32_t aNamespaceID,
                                            nsAtom* aAttribute) {
+  if (OwnerDoc()->CloningForSVGUse()) {
+    return;
+  }
   if (aNamespaceID == kNameSpaceID_None) {
     if (aAttribute == nsGkAtoms::width || aAttribute == nsGkAtoms::height) {
       const bool hadValidDimensions = HasValidDimensions();
@@ -407,8 +410,7 @@ void SVGUseElement::UpdateShadowTree() {
   RefPtr<Element> newElement;
 
   auto UpdateShadowTree = mozilla::MakeScopeExit([&]() {
-    nsIContent* firstChild = shadow->GetFirstChild();
-    if (firstChild) {
+    if (nsIContent* firstChild = shadow->GetFirstChild()) {
       MOZ_ASSERT(!firstChild->GetNextSibling());
       shadow->RemoveChildNode(firstChild, /* aNotify = */ true);
     }

testing/web-platform/tests/svg/types/scripted/SVGGraphicsElement-clone.svg

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg"
+     xmlns:h="http://www.w3.org/1999/xhtml">
+  <title>cloning a SVGGraphicsElement</title>
+  <metadata>
+    <h:link rel="help" href="https://svgwg.org/svg2-draft/types.html#InterfaceSVGGraphicsElement"/>
+  </metadata>
+  <h:script src="/resources/testharness.js"/>
+  <h:script src="/resources/testharnessreport.js"/>
+
+  <rect id="r" x="10">
+    <set id="set" begin="indefinite" attributeName="x" to="20" dur="15ms" fill="freeze"/>
+  </rect>
+
+  <script><![CDATA[
+    let el = document.getElementById("r");
+    let set = document.getElementById("set");
+
+    test(function() {
+      let clone = el.cloneNode();
+      assert_equals(clone.x.animVal.value, clone.x.baseVal.value);
+    }, 'check animVal equals baseVal by default');
+
+    async_test(t => {
+      set.beginElement();
+      set.addEventListener("beginEvent", t.step_func_done(function () {
+        assert_approx_equals(el.x.animVal.value, 20, 0.001);
+        let clone = el.cloneNode();
+        assert_approx_equals(clone.x.animVal.value, 10, 0.001);
+      }));
+    }, 'check clone does not copy the animated value');
+  ]]></script>
+</svg>