The NPE is caused by an inbound presence stanza without the 'from'
attribute set. The stacktrace of the NPE is:
FATAL EXCEPTION: Smack Cached Executor
Process: de.fhg.ivi.senetz.mobile.android.mbk.debug, PID: 13365
java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.Object.hashCode()' on a null object reference
at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:944)
at org.jivesoftware.smack.roster.Roster.getPresencesInternal(Roster.java:374)
at org.jivesoftware.smack.roster.Roster.getOrCreatePresencesInternal(Roster.java:388)
at org.jivesoftware.smack.roster.Roster.access$1100(Roster.java:94)
at org.jivesoftware.smack.roster.Roster$PresencePacketListener$1.run(Roster.java:1519)
at org.jivesoftware.smack.AsyncButOrdered$Handler.run(AsyncButOrdered.java:121)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
at java.lang.Thread.run(Thread.java:764)
Thanks to Marcel Heckel for reporting this.
Fixes SMACK-861.