Comment # 3 on bug 939452 from Neil Rickert

Created attachment 649465 [details]
Output of "journalctl -b" as requested

Yes, the problem still occurs with Beta1.

I followed your request, except that I uncommented "Enable=true" in the "debug"
section.  I assume that was what you really wanted.

I have two computers, sharing the same keyboard,video,mouse with a KVM switch. 
One is an older Dell running opensuse 13.2.  The other is a Lenovo ThinkServer
TS140 running Leap 42.1 Beta1.

After the change to custom.conf (and to /etc/sysconfig/displaymanager to set
"gdm"), I rebooted.

First login was as user "rickert" to Plasma 5.
I toggled the KVM switch (twice, to go to the Dell then back to the Lenovo).  I
could see that "gdm" was restarting.
I again toggled the KVM switch (just on the GDM login screen).  This one now
seems to be okay.
Next login was as user "support" to "icewm".  I toggled the KVM switch (twice
again), and could see "gdm" was restarting.

Final login was to user "rickert" to Plasma 5 to collect the output from
"journalctl -b" to a file for attaching.