auto merge of #4257 : johnathan79717/servo/4008, r=jdm

This is a fix for issue #4008.

2 files changed, 15 insertions, 4 deletions

diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index 8a4beae9dc4..174a43af664 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -47,6 +47,7 @@ use dom::htmltitleelement::HTMLTitleElement;
 use dom::location::Location;
 use dom::mouseevent::MouseEvent;
 use dom::keyboardevent::KeyboardEvent;
+use dom::messageevent::MessageEvent;
 use dom::node::{Node, ElementNodeTypeId, DocumentNodeTypeId, NodeHelpers};
 use dom::node::{CloneChildren, DoNotCloneChildren};
 use dom::nodelist::NodeList;
@@ -711,6 +712,8 @@ impl<'a> DocumentMethods for JSRef<'a, Document> {
                 global::Window(*window))),
             "keyboardevent" | "keyevents" => Ok(EventCast::from_temporary(
                 KeyboardEvent::new_uninitialized(*window))),
+            "messageevent" => Ok(EventCast::from_temporary(
+                MessageEvent::new_uninitialized(global::Window(*window)))),
             _ => Err(NotSupported)
         }
     }
diff --git a/components/script/dom/messageevent.rs b/components/script/dom/messageevent.rs
index f2540a4bb85..32842fd2897 100644
--- a/components/script/dom/messageevent.rs
+++ b/components/script/dom/messageevent.rs
@@ -16,7 +16,7 @@ use dom::eventtarget::{EventTarget, EventTargetHelpers};
 use servo_util::str::DOMString;
 
 use js::jsapi::JSContext;
-use js::jsval::JSVal;
+use js::jsval::{JSVal, UndefinedValue};
 
 #[dom_struct]
 pub struct MessageEvent {
@@ -43,13 +43,21 @@ impl MessageEvent {
         }
     }
 
+    pub fn new_uninitialized(global: GlobalRef) -> Temporary<MessageEvent> {
+        MessageEvent::new_initialized(global, UndefinedValue(), "".to_string(), "".to_string())
+    }
+
+    pub fn new_initialized(global: GlobalRef, data: JSVal, origin: DOMString, lastEventId: DOMString) -> Temporary<MessageEvent> {
+        reflect_dom_object(box MessageEvent::new_inherited(data, origin, lastEventId),
+        global,
+        MessageEventBinding::Wrap)
+    }
+
     pub fn new(global: GlobalRef, type_: DOMString,
                bubbles: bool, cancelable: bool,
                data: JSVal, origin: DOMString, lastEventId: DOMString)
                -> Temporary<MessageEvent> {
-        let ev = reflect_dom_object(box MessageEvent::new_inherited(data, origin, lastEventId),
-                                    global,
-                                    MessageEventBinding::Wrap).root();
+        let ev = MessageEvent::new_initialized(global, data, origin, lastEventId).root();
         let event: JSRef<Event> = EventCast::from_ref(*ev);
         event.InitEvent(type_, bubbles, cancelable);
         Temporary::from_rooted(*ev)