Partition merges when using topology hints can cause null pointers and leave the system in an unstable state

Caused by: java.lang.NullPointerException
	at org.infinispan.distribution.DistributionManagerImpl.informRehashOnJoin(DistributionManagerImpl.java:475)
	at org.infinispan.commands.control.RehashControlCommand.perform(RehashControlCommand.java:134)
	at org.infinispan.remoting.InboundInvocationHandlerImpl.handleInternal(InboundInvocationHandlerImpl.java:145)
	at org.infinispan.remoting.InboundInvocationHandlerImpl.handleWithWaitForBlocks(InboundInvocationHandlerImpl.java:159)
	at org.infinispan.remoting.InboundInvocationHandlerImpl.handleWithRetry(InboundInvocationHandlerImpl.java:249)
	at org.infinispan.remoting.InboundInvocationHandlerImpl.handle(InboundInvocationHandlerImpl.java:131)
	at org.infinispan.remoting.transport.jgroups.CommandAwareRpcDispatcher.executeCommand(CommandAwareRpcDispatcher.java:159)
	at org.infinispan.remoting.transport.jgroups.CommandAwareRpcDispatcher.handle(CommandAwareRpcDispatcher.java:144)
	at org.jgroups.blocks.RequestCorrelator.handleRequest(RequestCorrelator.java:577)
	at org.jgroups.blocks.RequestCorrelator.receiveMessage(RequestCorrelator.java:488)
	at org.jgroups.blocks.RequestCorrelator.receive(RequestCorrelator.java:364)

Caused by: java.lang.NullPointerException
    at org.infinispan.distribution.DistributionManagerImpl.rehash(DistributionManagerImpl.java:283)
    at org.infinispan.distribution.DistributionManagerImpl$ViewChangeListener.handleViewChange(DistributionManagerImpl.java:563) 
    at sun.reflect.GeneratedMethodAccessor482.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.infinispan.notifications.AbstractListenerImpl$ListenerInvocation$1.run(AbstractListenerImpl.java:175)