whenever network connectivity changes, polari reconnects to the open rooms. Because of the connectivity change, the nickname is already taken for this chat. Now polari adds an underscore to the nick like it is common practice. All fine so far.

However, if this occurs multiple times, each time polari reconnects, one ADDITIONAL underscore is added, which results in a very long trail of underscores after the original nickname.

Instead, polari should test if the original nickname is still available and use it if so.