JGRP-2997 Util.parseCommaDelimitedHostsInto returns no addresses when…

[rhusar]

… called with StackType.Dual

https://redhat.atlassian.net/browse/JGRP-2997

[rhusar]

So, this fixes the dead code and conditions that can never be met (inet == null is always false).

However this is never called with StackType.Dual as org.jgroups.protocols.TCPPING#stack_type defaults to Dual BUT it gets overriden in TCPPING#init to specific stack.

[rhusar]

The context for this is jgroups-extras/jgroups-kubernetes#309 – Implement support for KUBE_PING to discover IPs for pods with multiple IPs/dualstack especially IPv6 matching the transport stack
– where I would want to do this without explicit configuration just by consulting the bind address of the transport:

boolean preferIPv6 = transport.getBindAddr() instanceof Inet6Address;

however, I am discovering issues with how Dual stack is being handled here in jgroups.

[belaban]

Removed the inner ports for-loop if add is false, applied manually