Issue only appears on IBM JDK 6, it appears to result from IBM JDK 6 using apache harmony and hitting this bug: https://issues.apache.org/jira/browse/HARMONY-4229
Verified in EAP 6.4.7.CP.CR2. Due to bug in Apache Harmony with IBM JDK 1.6 [1] expected role with '/' character is still not assigned to user. However fix of this BZ causes that authentication can proceed and does not fail with IllegalArgumentException (caused by Apache Harmony bug). [1] https://issues.apache.org/jira/browse/HARMONY-4229
Retroactively bulk-closing issues from released EAP 6.4 cumulative patches.