Potential bug in ZeroMQ Last Value Caching pattern

[gbr]

I've been tearing my hair over this and can only conclude that there's a bug in how subscribers register at a XPUB socket. It seems like the first subscriber acts as specified in the LVC example, but any subsequent subscriber doesn't. The problem is described at http://stackoverflow.com/questions/30864145/zmq-cant-subscribe-to-topic-last-value-caching.

I'd really appreciate if someone could take a look at this (there's also an example that demonstrates that it doesn't work).

Thanks.