IPv6 related NPE in ServiceInfoImpl.getHostAddresses()

[bubbleguuum]

jmdns version: 3.5.6.

I've got a few automated crash reports with this stack trace, with getHostAddress() called in a ServiceListener.serviceResolved() callback:

Caused by: java.lang.NullPointerException
at javax.jmdns.impl.ServiceInfoImpl.getHostAddresses(ServiceInfoImpl.java:420)
at javax.jmdns.impl.ServiceInfoImpl.getHostAddress(ServiceInfoImpl.java:404)

looking at getHostAddresses():

 @Override
    public String[] getHostAddresses() {
        Inet4Address[] ip4Aaddresses = this.getInet4Addresses();
        Inet6Address[] ip6Aaddresses = this.getInet6Addresses();
        String[] names = new String[ip4Aaddresses.length + ip6Aaddresses.length];
        for (int i = 0; i < ip4Aaddresses.length; i++) {
            names[i] = ip4Aaddresses[i].getHostAddress();
        }
        for (int i = 0; i < ip6Aaddresses.length; i++) {
            names[i + ip4Aaddresses.length] = "[" + ip6Aaddresses[i].getHostAddress() + "]";    
        }
        return names;
    }

line 420 is:

names[i + ip4Aaddresses.length] = "[" + ip6Aaddresses[i].getHostAddress() + "]";    

The only possible thing null on that line is ip6Aaddresses[i].
So I suppose getInet6Addresses() can return an Inet6Address[] where some elements are null.

I have not checked if v3.5.8 would fix this issue but I doubt it.
Anyway, since my program does not make use of ipv6 at all, I worked-around this issue issue calling ServiceInfoImpl.getInet4Address().getHostAddress().
Still it would be nice to get the bottom line of that NPE.

[ViToni]

Error is also present with v3.5.8.

[usnasoft]

This issue is probably retated to issue "ipv6 #260"

[ViToni]

It is not in my case as it happened on Java 8 which is not mentioned in the JDK bug.

[kaikreuzer]

If anyone is able to reproduce/debug it and provide a PR, I'm happy to merge it and do a new patch release.