Comment # 30 on bug 939594 from Dominique Leuenberger

So far just some more 'prove' that the permissions are set and reset..

from the log file of test https://openqa.opensuse.org/tests/87357

>Oct 05 10:49:41 linux-3aux /usr/lib/gdm/gdm-x-session[1637]: (++) using VT number 7
>Oct 05 10:49:41 linux-3aux /usr/lib/gdm/gdm-x-session[1637]: (II) crw--w---- 1 bernhard tty 4, 7 Oct  5 10:49 /dev/tty7
>Oct 05 10:49:41 linux-3aux /usr/lib/gdm/gdm-x-session[1637]: (II) systemd-logind: took control of session /org/freedesktop/login1/session/_31

^^ systemd-logind DID correctly set the permission to bernhard.tty, as was to
be expected

[...]

>Oct 05 10:49:41 linux-3aux /usr/lib/gdm/gdm-x-session[1637]: (II) crw--w---- 1 root tty 4, 7 Oct  5 10:49 /dev/tty7
>Oct 05 10:49:41 linux-3aux /usr/lib/gdm/gdm-x-session[1637]: (EE)
>Oct 05 10:49:41 linux-3aux /usr/lib/gdm/gdm-x-session[1637]: Fatal server error:
>Oct 05 10:49:41 linux-3aux /usr/lib/gdm/gdm-x-session[1637]: (EE) xf86OpenConsole: Cannot open virtual console 7 (Permission denied)

^^ The permission has been reset to root.tty (breaking X' startup).

At this very moment, my efforts are actually showing that 'something' ==
'systemd'. The current theory is that the service type forking (as used by
display-manager.service) is causing this;

systemd seems to be calling chown_terminal in this case and this resetting the
permissions.