NullPointer in websocketsampler when closing websocket connection

[Steef Burghouts]

When the websocket sampler is configured with the option "websocket.thread.stop.policy=wsclose" the connection do actually close correctly the the reason "test thread finished". However for every connection close a nullpointer is raised as well within Jmeter:

2017-10-27 10:02:43,313 ERROR o.a.j.JMeter: Uncaught exception: 
java.lang.NullPointerException: null
    at eu.luminis.jmeter.wssampler.WebsocketSampler.threadFinished(WebsocketSampler.java:260) ~[JMeterWebSocketSamplers-mc.jar:?]
    at org.apache.jmeter.threads.JMeterThread$ThreadListenerTraverser.addNode(JMeterThread.java:685) ~[ApacheJMeter_core.jar:3.3 r1808647]
    at org.apache.jorphan.collections.HashTree.traverseInto(HashTree.java:996) ~[jorphan.jar:3.3 r1808647]
    at org.apache.jorphan.collections.HashTree.traverseInto(HashTree.java:997) ~[jorphan.jar:3.3 r1808647]
    at org.apache.jorphan.collections.HashTree.traverse(HashTree.java:978) ~[jorphan.jar:3.3 r1808647]
    at org.apache.jmeter.threads.JMeterThread.threadFinished(JMeterThread.java:657) ~[ApacheJMeter_core.jar:3.3 r1808647]
    at org.apache.jmeter.threads.JMeterThread.run(JMeterThread.java:311) ~[ApacheJMeter_core.jar:3.3 r1808647]
    at java.lang.Thread.run(Thread.java:745) [?:1.8.0_65]

[Peter Doornbosch]

Hi Steef,

Thanks for reporting. I guess you are using the "multiple connections" branch..... I could reproduce it and fixed it.

Regards Peter