It also asks for a password prior to attemting to connect in case the password is null, this alows host entries not to store the passwords on file like it has done so far.
NOTE: This is not yet the desired behaviour, ie, the daemon should simply complain if the authentication details are incomplete and the client should act accordingly. I had an issue with this though, I catched the errback the daemon was sending, asked the user for the password and re-tried to authenticate again. However, twisted always locked when I tried this. I'm investigating it.