[jsr356] Possible NPE on close

[jfarcand]

java.lang.NullPointerException: null
at org.atmosphere.websocket.DefaultWebSocketProcessor.executeClose(DefaultWebSocketProcessor.java:675)
at org.atmosphere.websocket.DefaultWebSocketProcessor.close(DefaultWebSocketProcessor.java:626)
at org.atmosphere.container.JSR356Endpoint.onClose(JSR356Endpoint.java:268)
at org.apache.tomcat.websocket.WsSession.fireEndpointOnClose(WsSession.java:527)
at org.apache.tomcat.websocket.WsSession.onClose(WsSession.java:511)
at org.apache.tomcat.websocket.WsFrameBase.processDataControl(WsFrameBase.java:342)
at org.apache.tomcat.websocket.WsFrameBase.processData(WsFrameBase.java:284)
at org.apache.tomcat.websocket.WsFrameBase.processInputBuffer(WsFrameBase.java:130)
at org.apache.tomcat.websocket.server.WsFrameServer.onDataAvailable(WsFrameServer.java:60)
at org.apache.tomcat.websocket.server.WsHttpUpgradeHandler$WsReadListener.onDataAvailable(WsHttpUpgradeHandler.java:203)
at org.apache.coyote.http11.upgrade.AbstractServletInputStream.onDataAvailable(AbstractServletInputStream.java:198)
at org.apache.coyote.http11.upgrade.AbstractProcessor.upgradeDispatch(AbstractProcessor.java:96)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:654)
at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1558)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1515)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)