Provide the source window as part of postMessage events.

components/script/dom/messageevent.rs

@@ -7,24 +7,27 @@ use crate::dom::bindings::codegen::Bindings::MessageEventBinding;
 use crate::dom::bindings::codegen::Bindings::MessageEventBinding::MessageEventMethods;
 use crate::dom::bindings::error::Fallible;
 use crate::dom::bindings::inheritance::Castable;
-use crate::dom::bindings::reflector::reflect_dom_object;
-use crate::dom::bindings::root::DomRoot;
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject};
+use crate::dom::bindings::root::{Dom, DomRoot};
 use crate::dom::bindings::str::DOMString;
 use crate::dom::bindings::trace::RootedTraceableBox;
 use crate::dom::event::Event;
 use crate::dom::eventtarget::EventTarget;
 use crate::dom::globalscope::GlobalScope;
+use crate::dom::windowproxy::WindowProxy;
 use dom_struct::dom_struct;
-use js::jsapi::{Heap, JSContext};
+use js::jsapi::{Heap, JSContext, JSObject};
 use js::jsval::JSVal;
 use js::rust::HandleValue;
 use servo_atoms::Atom;
+use std::ptr::NonNull;
 
 #[dom_struct]
 pub struct MessageEvent {
     event: Event,
     data: Heap<JSVal>,
     origin: DOMString,
+    source: Option<Dom<WindowProxy>>,
     lastEventId: DOMString,
 }
 
@@ -34,6 +37,7 @@ impl MessageEvent {
             global,
             HandleValue::undefined(),
             DOMString::new(),
+            None,
             DOMString::new(),
         )
     }
@@ -42,12 +46,14 @@ impl MessageEvent {
         global: &GlobalScope,
         data: HandleValue,
         origin: DOMString,
+        source: Option<&WindowProxy>,
         lastEventId: DOMString,
     ) -> DomRoot<MessageEvent> {
         let ev = Box::new(MessageEvent {
             event: Event::new_inherited(),
             data: Heap::default(),
             origin: origin,
+            source: source.map(Dom::from_ref),
             lastEventId: lastEventId,
         });
         let ev = reflect_dom_object(ev, global, MessageEventBinding::Wrap);
@@ -63,9 +69,10 @@ impl MessageEvent {
         cancelable: bool,
         data: HandleValue,
         origin: DOMString,
+        source: Option<&WindowProxy>,
         lastEventId: DOMString,
     ) -> DomRoot<MessageEvent> {
-        let ev = MessageEvent::new_initialized(global, data, origin, lastEventId);
+        let ev = MessageEvent::new_initialized(global, data, origin, source, lastEventId);
         {
             let event = ev.upcast::<Event>();
             event.init_event(type_, bubbles, cancelable);
@@ -78,6 +85,10 @@ impl MessageEvent {
         type_: DOMString,
         init: RootedTraceableBox<MessageEventBinding::MessageEventInit>,
     ) -> Fallible<DomRoot<MessageEvent>> {
+        let source = init
+            .source
+            .as_ref()
+            .and_then(|inner| inner.as_ref().map(|source| source.window_proxy()));
         let ev = MessageEvent::new(
             global,
             Atom::from(type_),
@@ -85,6 +96,7 @@ impl MessageEvent {
             init.parent.cancelable,
             init.data.handle(),
             init.origin.clone(),
+            source.as_ref().map(|source| &**source),
             init.lastEventId.clone(),
         );
         Ok(ev)
@@ -97,6 +109,7 @@ impl MessageEvent {
         scope: &GlobalScope,
         message: HandleValue,
         origin: Option<&str>,
+        source: Option<&WindowProxy>,
     ) {
         let messageevent = MessageEvent::new(
             scope,
@@ -105,6 +118,7 @@ impl MessageEvent {
             false,
             message,
             DOMString::from(origin.unwrap_or("")),
+            source,
             DOMString::new(),
         );
         messageevent.upcast::<Event>().fire(target);
@@ -123,6 +137,14 @@ impl MessageEventMethods for MessageEvent {
         self.origin.clone()
     }
 
+    // https://html.spec.whatwg.org/multipage/#dom-messageevent-source
+    #[allow(unsafe_code)]
+    unsafe fn GetSource(&self, _cx: *mut JSContext) -> Option<NonNull<JSObject>> {
+        self.source
+            .as_ref()
+            .and_then(|source| NonNull::new(source.reflector().get_jsobject().get()))
+    }
+
     // https://html.spec.whatwg.org/multipage/#dom-messageevent-lasteventid
     fn LastEventId(&self) -> DOMString {
         self.lastEventId.clone()