Bug 735280 - Part 2: Add pre-create to nsXPComponents. r=bholley

js/xpconnect/src/XPCComponents.cpp

@@ -4193,7 +4193,8 @@ NS_IMETHODIMP
 nsXPCComponents::GetHelperForLanguage(PRUint32 language,
                                       nsISupports **retval)
 {
-    *retval = nsnull;
+    *retval = static_cast<nsIXPCComponents*>(this);
+    NS_ADDREF(this);
     return NS_OK;
 }
 
@@ -4341,6 +4342,7 @@ nsXPCComponents::GetManager(nsIComponentManager * *aManager)
 #define                             XPC_MAP_WANT_NEWRESOLVE
 #define                             XPC_MAP_WANT_GETPROPERTY
 #define                             XPC_MAP_WANT_SETPROPERTY
+#define                             XPC_MAP_WANT_PRECREATE
 #define XPC_MAP_FLAGS               nsIXPCScriptable::ALLOW_PROP_MODS_DURING_RESOLVE
 #include "xpc_map_end.h" /* This will #undef the above */
 
@@ -4429,16 +4431,20 @@ nsXPCComponents::SetProperty(nsIXPConnectWrappedNative *wrapper,
 
 // static
 JSBool
-nsXPCComponents::AttachNewComponentsObject(XPCCallContext& ccx,
-                                           XPCWrappedNativeScope* aScope,
-                                           JSObject* aGlobal)
+nsXPCComponents::AttachComponentsObject(XPCCallContext& ccx,
+                                        XPCWrappedNativeScope* aScope,
+                                        JSObject* aGlobal)
 {
     if (!aGlobal)
         return false;
 
-    nsXPCComponents* components = new nsXPCComponents(aScope);
-    if (!components)
-        return false;
+    nsXPCComponents* components = aScope->GetComponents();
+    if (!components) {
+        components = new nsXPCComponents(aScope);
+        if (!components)
+            return false;
+        aScope->SetComponents(components);
+    }
 
     nsCOMPtr<nsIXPCComponents> cholder(components);
 
@@ -4454,8 +4460,6 @@ nsXPCComponents::AttachNewComponentsObject(XPCCallContext& ccx,
     if (!wrapper)
         return false;
 
-    aScope->SetComponents(components);
-
     jsid id = ccx.GetRuntime()->GetStringID(XPCJSRuntime::IDX_COMPONENTS);
     JSObject* obj;
 
@@ -4530,3 +4534,15 @@ nsXPCComponents::CanSetProperty(const nsIID * iid, const PRUnichar *propertyName
     *_retval = nsnull;
     return NS_OK;
 }
+
+NS_IMETHODIMP
+nsXPCComponents::PreCreate(nsISupports *nativeObj, JSContext *cx, JSObject *globalObj, JSObject **parentObj)
+{
+  // this should never happen
+  if (!mScope) {
+      NS_WARNING("mScope must not be null when nsXPCComponents::PreCreate is called");
+      return NS_ERROR_FAILURE;
+  }
+  *parentObj = mScope->GetGlobalJSObject();
+  return NS_OK;
+}

js/xpconnect/src/nsXPConnect.cpp

@@ -1020,7 +1020,7 @@ nsXPConnect::InitClasses(JSContext * aJSContext, JSObject * aGlobalJSObj)
 
     scope->RemoveWrappedNativeProtos();
 
-    if (!nsXPCComponents::AttachNewComponentsObject(ccx, scope, aGlobalJSObj))
+    if (!nsXPCComponents::AttachComponentsObject(ccx, scope, aGlobalJSObj))
         return UnexpectedFailure(NS_ERROR_FAILURE);
 
     if (XPCPerThreadData::IsMainThread(ccx)) {
@@ -1222,7 +1222,7 @@ nsXPConnect::InitClassesWithNewWrappedGlobal(JSContext * aJSContext,
 
     if (!(aFlags & nsIXPConnect::OMIT_COMPONENTS_OBJECT)) {
         // XPCCallContext gives us an active request needed to save/restore.
-        if (!nsXPCComponents::AttachNewComponentsObject(ccx, wrappedGlobal->GetScope(), global))
+        if (!nsXPCComponents::AttachComponentsObject(ccx, wrappedGlobal->GetScope(), global))
             return UnexpectedFailure(NS_ERROR_FAILURE);
 
         if (XPCPerThreadData::IsMainThread(ccx)) {

js/xpconnect/src/xpcprivate.h

@@ -3888,9 +3888,9 @@ public:
 
 public:
     static JSBool
-    AttachNewComponentsObject(XPCCallContext& ccx,
-                              XPCWrappedNativeScope* aScope,
-                              JSObject* aGlobal);
+    AttachComponentsObject(XPCCallContext& ccx,
+                           XPCWrappedNativeScope* aScope,
+                           JSObject* aGlobal);
 
     void SystemIsBeingShutDown() {ClearMembers();}