Bug 1404107 - Refactor: Move some reparenting complexity into XPConnect. r=mrbkap,r=bz

--HG--
extra : rebase_source : 817ef532b2fe67bc901339aa19d84bf571adfc71

dom/bindings/BindingUtils.cpp

@@ -2259,11 +2259,6 @@ ReparentWrapper(JSContext* aCx, JS::Handle<JSObject*> aObjArg, ErrorResult& aErr
     propertyHolder = nullptr;
   }
 
-  // Grab a reference to the chain of objects that carry aObj's Xray expando
-  // properties (from all compartments). Transplanting will blow this away;
-  // we'll restore it manually afterwards.
-  JS::Rooted<JSObject*> expandoChain(aCx, xpc::XrayUtils::GetExpandoChain(aObj));
-
   // We've set up |newobj|, so we make it own the native by setting its reserved
   // slot and nulling out the reserved slot of |obj|.
   //
@@ -2274,19 +2269,11 @@ ReparentWrapper(JSContext* aCx, JS::Handle<JSObject*> aObjArg, ErrorResult& aErr
                       js::GetReservedSlot(aObj, DOM_OBJECT_SLOT));
   js::SetReservedSlot(aObj, DOM_OBJECT_SLOT, JS::PrivateValue(nullptr));
 
-  aObj = xpc::TransplantObject(aCx, aObj, newobj);
+  aObj = xpc::TransplantObjectRetainingXrayExpandos(aCx, aObj, newobj);
   if (!aObj) {
     MOZ_CRASH();
   }
 
-  // Copy Xray expando properties to the new wrapper.
-  if (!xpc::XrayUtils::CloneExpandoChain(aCx, aObj, expandoChain)) {
-    // Failure here means some expandos were not copied over. The object graph
-    // and the Xray machinery are left in a consistent state, but mysteriously
-    // losing these expandos is too weird to allow.
-    MOZ_CRASH();
-  }
-
   nsWrapperCache* cache = nullptr;
   CallQueryInterface(native, &cache);
   bool preserving = cache->PreservingWrapper();

js/xpconnect/src/xpcpublic.h

@@ -77,6 +77,9 @@ private:
 JSObject*
 TransplantObject(JSContext* cx, JS::HandleObject origobj, JS::HandleObject target);
 
+JSObject*
+TransplantObjectRetainingXrayExpandos(JSContext* cx, JS::HandleObject origobj, JS::HandleObject target);
+
 bool IsContentXBLCompartment(JSCompartment* compartment);
 bool IsContentXBLScope(JS::Realm* realm);
 bool IsInContentXBLScope(JSObject* obj);

js/xpconnect/wrappers/WrapperFactory.cpp

@@ -682,6 +682,28 @@ TransplantObject(JSContext* cx, JS::HandleObject origobj, JS::HandleObject targe
     return newIdentity;
 }
 
+JSObject*
+TransplantObjectRetainingXrayExpandos(JSContext* cx, JS::HandleObject origobj,
+                                      JS::HandleObject target)
+{
+    // Save the chain of objects that carry origobj's Xray expando properties
+    // (from all compartments). TransplantObject will blow this away; we'll
+    // restore it manually afterwards.
+    RootedObject expandoChain(cx, GetXrayTraits(origobj)->getExpandoChain(origobj));
+
+    RootedObject newIdentity(cx, TransplantObject(cx, origobj, target));
+
+    // Copy Xray expando properties to the new wrapper.
+    if (!GetXrayTraits(newIdentity)->cloneExpandoChain(cx, newIdentity, expandoChain)) {
+        // Failure here means some expandos were not copied over. The object graph
+        // and the Xray machinery are left in a consistent state, but mysteriously
+        // losing these expandos is too weird to allow.
+        MOZ_CRASH();
+    }
+
+    return newIdentity;
+}
+
 nsIGlobalObject*
 NativeGlobal(JSObject* obj)
 {

js/xpconnect/wrappers/XrayWrapper.cpp

@@ -1299,18 +1299,6 @@ XrayTraits::getExpandoClass(JSContext* cx, HandleObject target) const
     return &DefaultXrayExpandoObjectClass;
 }
 
-namespace XrayUtils {
-JSObject* GetExpandoChain(HandleObject target)
-{
-    return GetXrayTraits(target)->getExpandoChain(target);
-}
-
-bool CloneExpandoChain(JSContext* cx, HandleObject dst, HandleObject srcChain)
-{
-    return GetXrayTraits(dst)->cloneExpandoChain(cx, dst, srcChain);
-}
-} // namespace XrayUtils
-
 static JSObject*
 GetHolder(JSObject* obj)
 {

js/xpconnect/wrappers/XrayWrapper.h

@@ -38,12 +38,6 @@ namespace XrayUtils {
 bool
 IsXPCWNHolderClass(const JSClass* clasp);
 
-JSObject*
-GetExpandoChain(JS::HandleObject target);
-
-bool
-CloneExpandoChain(JSContext* cx, JS::HandleObject dst, JS::HandleObject srcChain);
-
 bool
 IsTransparent(JSContext* cx, JS::HandleObject wrapper, JS::HandleId id);