Details
Urgent Description
In CASSANDRA-6135 we added cloneWithHigherVersion to ensure that if another thread added states to gossip while we were notifying we would increase our version to ensure the existing states wouldn't get shadowed. This however, was not entirely perfect since it's possible that after the clone, but before the addition another thread will insert an even newer state, thus shadowing the others. A common case (of this rare one) is when STATUS and TOKENS are added a bit later in SS.setGossipTokens, where something in another thread injects a new state (likely SEVERITY) just before the addition after the clone.