Missing socketpair initialization in client library

[zanettea]

In mosquitto_reinitialise the socketpairR/W should be initialized as invalid as mosq->sock is, since, otherwise, if the function returns because the client id is missing or invalid, socketpairs still are valid handles (namely 0) and a further call to moquitto_destroy could try to close them causing unexpected behaviors in the hosting application.

[ralight]

Thank you, this is a good find. I've now fixed it in the fixes branch.

[ralight]

Sorry, we just overlapped on fixing it!

[zanettea]

Np, thanks for the lighting fast fix :)