c65a9c4d2e
The Next and Sign In buttons are disabled when the username/password field is empty. However, the user can still bypass this button by pressing the enter key, leading to some odd glitches with the log in for 'Not Listed?' users. This is easy to fix by simply not progressing to the next screen when the button is disabled. https://bugzilla.gnome.org/show_bug.cgi?id=746180