Publish Exception on Broker

What steps will reproduce the problem?
1. Start Moquette Broker in application or as single application
2. Publish a message on topic 'log' as retained (mostly QoS 2)
3. Close Broker and start again. 
4. Publish a message on 'log'. 
5. See error

What is the expected output? What do you see instead?
I expect no error and correct publishing, but this is not quarenteed. 
I got this stacktrace:
21295 [NioProcessor-2] INFO  SERVER LOG  - SENT: HeapBuffer[pos=0 lim=0 cap=0: 
empty]
21297 [pool-3-thread-1] ERROR SimpleMessaging  - 
java.lang.NullPointerException
    at org.dna.mqtt.moquette.messaging.spi.impl.SimpleMessaging.notify(SimpleMessaging.java:503)
    at org.dna.mqtt.moquette.messaging.spi.impl.SimpleMessaging.publish2Subscribers(SimpleMessaging.java:369)
    at org.dna.mqtt.moquette.messaging.spi.impl.SimpleMessaging.processPubRel(SimpleMessaging.java:303)
    at org.dna.mqtt.moquette.messaging.spi.impl.SimpleMessaging.onEvent(SimpleMessaging.java:184)
    at org.dna.mqtt.moquette.messaging.spi.impl.SimpleMessaging.onEvent(SimpleMessaging.java:39)
    at com.lmax.disruptor.BatchEventProcessor.run(BatchEventProcessor.java:113)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
    at java.util.concurrent.FutureTask.run(FutureTask.java:166)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:722)

What version of the product are you using? On what operating system?
moquette-broker-0.1-jar-with-dependencies.jar    Self contained broker jar v0.1  
Sep 17

Please provide any additional information below.
I have a linux system. Run the broker only on localhost. Publishing 
applications are mosquitto_pub and Java applications with Paho MQTT Java 
Library.
Original issue reported on code.google.com by andreslo...@gmail.com on 25 Feb 2013 at 8:52
maydemirx / moquette-mqtt

Publish Exception on Broker #8
