webrev: http://cr.openjdk.java.net/~sjiang/JDK-7120365/webrev.00/
The test is correct, it was implemented to verify the fix for bug 4911721, but in addition it detects luckily another problem within the method ServerNotifForwarder.snoopOnUnregister
The problem was that during a "for" cycle, the set list was modified by anther thread, the solution is to use a unmodifiable set.
This fix is important, it not only re-enables a test, but also fixes a concurrent modification bug in the jmx notification.
Shanliang
