Description
If a SimpleAuthenticationPlugin is defined in the configuration without any users element, then when a client which does supply a username attempts to connect an NPE occurs in the broker.
E.g, defining broker config as:
<simpleAuthenticationPlugin anonymousAccessAllowed="true" />
And trying to log in, results in:
java.lang.NullPointerException at org.apache.activemq.security.SimpleAuthenticationBroker.addConnection(SimpleAuthenticationBroker.java:83) ... <snip>