This is a bit icky, but it's the easiest way to solve a problem
I've seen a few times, the latest case being
https://openqa.stg.fedoraproject.org/tests/1664 . In that test,
_console_wait_login logs in to tty1 as user, then uefi_
postinstall wants to switch to tty3 and log in as root. When
it does that, sometimes the check_screen loop in console_login
gets hit before the display has actually switched from tty1 to
tty3, so everything gets out of sync.
An alternative would be to have root_console check that it's
either logged in or at the correct tty before handing off to
console_login, but that starts duplicating stuff, and it breaks
in the case the target tty is logged in as a user and the login
prompt is no longer visible...