From 46300eb42bea84017b51006f2a65f8c0336d9244 Mon Sep 17 00:00:00 2001
From: Andrea Marchesini <amarchesini@mozilla.com>
Date: Tue, 12 Sep 2017 11:57:26 +0200
Subject: [PATCH] Bug 1359017 - onmessageerror for MessagePort in case
 StructuredClone algorithm fails when deserializing, r=masayuki, r=smaug

---
 dom/base/nsGkAtomList.h            |  1 +
 dom/messagechannel/MessagePort.cpp | 19 +++++++++++++++++--
 dom/messagechannel/MessagePort.h   |  4 ++++
 dom/webidl/MessagePort.webidl      |  1 +
 4 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/dom/base/nsGkAtomList.h b/dom/base/nsGkAtomList.h
index 71e816617056..a03d99c038fe 100644
--- a/dom/base/nsGkAtomList.h
+++ b/dom/base/nsGkAtomList.h
@@ -920,6 +920,7 @@ GK_ATOM(onloadingerror, "onloadingerror")
 GK_ATOM(onpopstate, "onpopstate")
 GK_ATOM(only, "only")               // this one is not an event
 GK_ATOM(onmessage, "onmessage")
+GK_ATOM(onmessageerror, "onmessageerror")
 GK_ATOM(onmousedown, "onmousedown")
 GK_ATOM(onmouseenter, "onmouseenter")
 GK_ATOM(onmouseleave, "onmouseleave")
diff --git a/dom/messagechannel/MessagePort.cpp b/dom/messagechannel/MessagePort.cpp
index aaf3ef0ef373..fb249a3696ed 100644
--- a/dom/messagechannel/MessagePort.cpp
+++ b/dom/messagechannel/MessagePort.cpp
@@ -694,7 +694,7 @@ MessagePort::Entangled(nsTArray<ClonedMessageData>& aMessages)
   FallibleTArray<RefPtr<SharedMessagePortMessage>> data;
   if (NS_WARN_IF(!SharedMessagePortMessage::FromMessagesToSharedChild(aMessages,
                                                                       data))) {
-    // OOM, we cannot continue.
+    DispatchError();
     return;
   }
 
@@ -748,7 +748,7 @@ MessagePort::MessagesReceived(nsTArray<ClonedMessageData>& aMessages)
   FallibleTArray<RefPtr<SharedMessagePortMessage>> data;
   if (NS_WARN_IF(!SharedMessagePortMessage::FromMessagesToSharedChild(aMessages,
                                                                       data))) {
-    // OOM, We cannot continue.
+    DispatchError();
     return;
   }
 
@@ -1004,5 +1004,20 @@ MessagePort::ForceClose(const MessagePortIdentifier& aIdentifier)
   ForceCloseHelper::ForceClose(aIdentifier);
 }
 
+void
+MessagePort::DispatchError()
+{
+  MessageEventInit init;
+  init.mBubbles = false;
+  init.mCancelable = false;
+
+  RefPtr<Event> event =
+    MessageEvent::Constructor(this, NS_LITERAL_STRING("messageerror"), init);
+  event->SetTrusted(true);
+
+  bool dummy;
+  DispatchEvent(event, &dummy);
+}
+
 } // namespace dom
 } // namespace mozilla
diff --git a/dom/messagechannel/MessagePort.h b/dom/messagechannel/MessagePort.h
index 4ca51353dee8..00ad02a79004 100644
--- a/dom/messagechannel/MessagePort.h
+++ b/dom/messagechannel/MessagePort.h
@@ -74,6 +74,8 @@ class MessagePort final : public DOMEventTargetHelper
 
   void SetOnmessage(EventHandlerNonNull* aCallback);
 
+  IMPL_EVENT_HANDLER(messageerror)
+
   // Non WebIDL methods
 
   void UnshippedEntangle(MessagePort* aEntangledPort);
@@ -147,6 +149,8 @@ class MessagePort final : public DOMEventTargetHelper
   // Dispatch events from the Message Queue using a nsRunnable.
   void Dispatch();
 
+  void DispatchError();
+
   void StartDisentangling();
   void Disentangle();
 
diff --git a/dom/webidl/MessagePort.webidl b/dom/webidl/MessagePort.webidl
index 6495b5616de7..df19470742a9 100644
--- a/dom/webidl/MessagePort.webidl
+++ b/dom/webidl/MessagePort.webidl
@@ -17,5 +17,6 @@ interface MessagePort : EventTarget {
 
   // event handlers
   attribute EventHandler onmessage;
+  attribute EventHandler onmessageerror;
 };
 // MessagePort implements Transferable;