SpringBoot RSocketPortInfoApplicationContextInitializer can throw NPE

RSocket supports transports that do not require networking (rsocket-local-transport). As such, when I implementated RSocketServerFactory and RSocketServer, I returned null for RSocketServer.address() which leads to the exception below.

Caused by: java.lang.NullPointerException
    at org.springframework.boot.rsocket.context.RSocketPortInfoApplicationContextInitializer$Listener.onApplicationEvent(RSocketPortInfoApplicationContextInitializer.java:66)
    at org.springframework.boot.rsocket.context.RSocketPortInfoApplicationContextInitializer$Listener.onApplicationEvent(RSocketPortInfoApplicationContextInitializer.java:54)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:203)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:196)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:161)
    at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:426)
    at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:383)
    at org.springframework.boot.rsocket.context.RSocketServerBootstrap.start(RSocketServerBootstrap.java:53)
    at io.rsocket.routing.broker.spring.BrokerAutoConfiguration$BrokerRSocketServerBootstrap.start(BrokerAutoConfiguration.java:274)
    at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:178)
    ... 103 more

Comment From: wilkinsona

Thanks, @spencergibb!