Comment 7 for bug 1583624

I got the greeter working, but there are 2 other issues. The following assumes you are using the unity8 greeter to launch a unity7 session

if (seat-type == unity)
   The greeter loads, authenticates, a black screen is briefly shown, and the greeter comes back up. My theory here is that lightdm is trying to start unity7 on the same VT as the greeter, and this is making USC mad. I believe this will be fixed in USC in the future, but is there a work around we could have for the time being?

if (seat-type == xlocal)
   The log in /var/log/lightdm for the greeter is called (null)-greeter.log. I think this is because the code path taken doesn't call display_server_set_name in time. I used to know the answer to this, but I've since forgotten. I'm going to dig into this part further today, but if you have input, let me know.