When making effective use of the message_received callback handler added with
QPID-5799, an unintended side-effect occurs regarding exception handling.
The user registers the message_recieved callback using set_message_received_handler and then only calls back into qpid.messaging when it was told to do so. As a result when a ConnectionError occurs it is not raised. This effectively deadlocks the receiver since it can't know to call into qpid.messaging.