jenkinsci/jenkins — pull request #579 by JoelJ (2012-09-26 21:32:06+00:00)
Title: Fixing ClassCastException

casting the toArray result will sometimes cause ClassCastExceptions.
i.e.:
Caused by: java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to [Ljava.lang.String;
at hudson.security.WhoAmI.getAuthorities(WhoAmI.java:65)