1 files changed, 21 insertions, 14 deletions
diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index e133eb6cb46..9121fa75fc0 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -33,10 +33,11 @@ use ipc_channel::ipc::{self, IpcSender};
 use ipc_channel::router::ROUTER;
 use js::conversions::ToJSValConvertible;
 use js::jsapi::{GCReason, Heap, JSAutoRealm, JSObject, StackFormat, JSPROP_ENUMERATE, JS_GC};
-use js::jsval::{JSVal, NullValue, UndefinedValue};
+use js::jsval::{NullValue, UndefinedValue};
 use js::rust::wrappers::JS_DefineProperty;
 use js::rust::{
     CustomAutoRooter, CustomAutoRooterGuard, HandleObject, HandleValue, MutableHandleObject,
+    MutableHandleValue,
 };
 use malloc_size_of::MallocSizeOf;
 use media::WindowGLContext;
@@ -697,22 +698,32 @@ impl WindowMethods for Window {
     }
 
     // https://html.spec.whatwg.org/multipage/#dom-opener
-    fn GetOpener(&self, cx: JSContext, in_realm_proof: InRealm) -> Fallible<JSVal> {
+    fn GetOpener(
+        &self,
+        cx: JSContext,
+        in_realm_proof: InRealm,
+        mut retval: MutableHandleValue,
+    ) -> Fallible<()> {
         // Step 1, Let current be this Window object's browsing context.
         let current = match self.window_proxy.get() {
             Some(proxy) => proxy,
             // Step 2, If current is null, then return null.
-            None => return Ok(NullValue()),
+            None => {
+                retval.set(NullValue());
+                return Ok(());
+            },
         };
         // Still step 2, since the window's BC is the associated doc's BC,
         // see https://html.spec.whatwg.org/multipage/#window-bc
         // and a doc's BC is null if it has been discarded.
         // see https://html.spec.whatwg.org/multipage/#concept-document-bc
         if current.is_browsing_context_discarded() {
-            return Ok(NullValue());
+            retval.set(NullValue());
+            return Ok(());
         }
         // Step 3 to 5.
-        Ok(current.opener(*cx, in_realm_proof))
+        current.opener(*cx, in_realm_proof, retval);
+        Ok(())
     }
 
     #[allow(unsafe_code)]
@@ -1388,17 +1399,12 @@ impl WindowMethods for Window {
 
     // https://dom.spec.whatwg.org/#dom-window-event
     #[allow(unsafe_code)]
-    fn Event(&self, cx: JSContext) -> JSVal {
-        rooted!(in(*cx) let mut rval = UndefinedValue());
+    fn Event(&self, cx: JSContext, rval: MutableHandleValue) {
         if let Some(ref event) = *self.current_event.borrow() {
             unsafe {
-                event
-                    .reflector()
-                    .get_jsobject()
-                    .to_jsval(*cx, rval.handle_mut());
+                event.reflector().get_jsobject().to_jsval(*cx, rval);
             }
         }
-        rval.get()
     }
 
     fn IsSecureContext(&self) -> bool {
@@ -1571,9 +1577,10 @@ impl WindowMethods for Window {
         cx: JSContext,
         value: HandleValue,
         options: RootedTraceableBox<StructuredSerializeOptions>,
-    ) -> Fallible<js::jsval::JSVal> {
+        retval: MutableHandleValue,
+    ) -> Fallible<()> {
         self.upcast::<GlobalScope>()
-            .structured_clone(cx, value, options)
+            .structured_clone(cx, value, options, retval)
     }
 }