NPE observed in log while trying to reconnect a slave.
hudson.remoting.Channel$2#handle: Failed to execute command Pipe.EOF(19) (channel …)
java.lang.NullPointerException
	at hudson.remoting.ProxyWriter$EOF.execute(ProxyWriter.java:177)
	at hudson.remoting.Channel$2.handle(Channel.java:461)
	at hudson.remoting.SynchronousCommandTransport$ReaderThread.run(SynchronousCommandTransport.java:60)
hudson.remoting.Channel$2#handle: This command is created here
Command Pipe.EOF(19) created at
	at hudson.remoting.Command.<init>(Command.java:67)
	at hudson.remoting.Command.<init>(Command.java:50)
	at hudson.remoting.ProxyWriter$EOF.<init>(ProxyWriter.java:169)
	at hudson.remoting.ProxyWriter.close(ProxyWriter.java:124)
	at hudson.remoting.ProxyWriter.finalize(ProxyWriter.java:132)
	at java.lang.ref.Finalizer.invokeFinalizeMethod(Native Method)
	at java.lang.ref.Finalizer.runFinalizer(Finalizer.java:101)
	at java.lang.ref.Finalizer.access$100(Finalizer.java:32)
	at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:178)