Bug#770615: mate-session-manager: Switching users don't work with MATE and Lightdm

[John Paul Adrian Glaubitz]

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On 11/25/2014 03:32 PM, Mike Gabriel wrote:
> After looking at mate-session-manager code, I am not even sure if
> this feature in relation to LightDM will be available for MATE
> 1.10. It definitely won't be in Debian jessie (MATE 1.8).

Actually, it might be easier than you would think.

The session-manager tries to start a new greeter using the
'gdmflexiserver' command which is not available on lightdm. However,
lightdm provides the command 'dm-tool' which allows to start a new
greeter using the following command:

	dm-tool switch-to-greeter

If you replace /usr/bin/gdmflexiserver with a simple bash script
as described here [1], you will be able to switch users from the
mate-screensaver lock screen using the "Switch User" button.

It works absolutely fine except that after the new user has logged
out, the new greeter session is not killed and the screen returns
back to the lightdm greeter instead of the lock screen of the
previously logged in user. Clicking "Cancel" in the new lightdm
greeter session doesn't help either.

In any case, to get this implemented into the code, we would need to
define LIGHTDM_FLEXISERVER_COMMAND in mate-session/gsm-manager.c as
"dm-tool" and LIGHTDM_FLEXISERVER_ARGS as "switch-to-greeter".

If we figured out how to kill the new lightdm greeter after the second
user has logged out or someone clicked "Cancel" in the new lightdm
greeter session, user switching would work as expected with lightdm.

Cheers,
Adrian

> [1]
https://wiki.archlinux.org/index.php/LightDM#User_switching_under_Xfce4

- -- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz at debian.org
`. `'   Freie Universitaet Berlin - glaubitz at physik.fu-berlin.de
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913
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