'agetty' as for a user name and passes it forward to 'login', but if 'login' fails to log in it will
ask for a new user name. And 'login' does not handle input in the same way as 'agetty'.

'login' should be able to ask for user names, and so should 'agetty', and they do not need
to behave the same way. But if 'login' is given a user name it should never as for a new one,
only for a new password and except the user to cancel using ^C or ^D if the username is
incorrect.