https://bugs.winehq.org/show_bug.cgi?id=48293
--- Comment #10 from Alexandre Julliard julliard@winehq.org --- I guess the empty domain for some reason takes longer to resolve on your machine. You can probably try +winsock or +dnsapi traces to figure out why.
The previous version would return the hostname as domain name if the real domain name was empty, but I don't think we want to continue doing that. It's not what Windows does either.