1 files changed, 5 insertions, 1 deletions
diff --git a/WebCore/dom/MessagePort.h b/WebCore/dom/MessagePort.h
index 0ab0f50..ae1eb22 100644
--- a/WebCore/dom/MessagePort.h
+++ b/WebCore/dom/MessagePort.h
@@ -103,7 +103,10 @@ namespace WebCore {
         // Returns null otherwise.
         // NOTE: This is used solely to enable a GC optimization. Some platforms may not be able to determine ownership of the remote port (since it may live cross-process) - those platforms may always return null.
         MessagePort* locallyEntangledPort();
-        bool isEntangled() { return m_entangledChannel; }
+        // A port starts out its life entangled, and remains entangled until it is closed or is cloned.
+        bool isEntangled() { return !m_closed && !isCloned(); }
+        // A port is cloned if its entangled channel has been removed and sent to a new owner via postMessage().
+        bool isCloned() { return !m_entangledChannel; }
 
     private:
         MessagePort(ScriptExecutionContext&);
@@ -116,6 +119,7 @@ namespace WebCore {
         OwnPtr<MessagePortChannel> m_entangledChannel;
 
         bool m_started;
+        bool m_closed;
 
         ScriptExecutionContext* m_scriptExecutionContext;
         EventTargetData m_eventTargetData;