[LightDM] Two configuration issues with lightdm in Ubuntu 14.04 LTS Trusty

[b.king at surrey.ac.uk]

Hi Folks

We've got a couple of configuration issues with lightdm on Ubuntu 14.04
LTS Trusty and I wonder if any of you can help us:

Multiple VT’s

If you lock your screen, it can spawn a new greeter on VT8 – this
doesn’t seem to always happen, I haven’t worked out exactly what
situations cause this.  Usually, when it locks after a session idle
timeout, it just shows screensaver, manually asking it to lock gives you
a greeter in VT8.  I’ve not checked if logging in with a second account,
then locking that continues into VT9.

We would like to have only one GUI VT7 for our labs, either disabling
lock screen or auto-logging them out after ~15 mins.

Login session selection

Related to your own ~/.dmrc, the default set
in /etc/lightdm/lightdm.conf and /var/cache/lightdm/dmrc/$USER.dmrc
which seems to be created after first login

Defaults can get mixed up and simply not log you in.  I have noticed
this going from my trusty desktop in the office to a precise lab machine
– looks like it works after the first failed attempt without changing
anything (I guess it picks up the created lightdm cache .dmrc file)

Hope this is clear enough for you to see the problem, let me know if you
want some more investigation from our end.

Thanks for any help you can provide.

Regards, Bevis.