Bug#863227: system-config-printer: applet.py does not exit with session

[Sergio Gelato]

I'm seeing this as well --- under Xfce.

I'm under the impression that applet.py is waiting for the DBus session bus
to exit, but my system has dbus-user-session installed and it's possible
that systemd is waiting for applet.py to exit before it will shut that down.
Indeed if I send a SIGTERM to the session dbus-daemon that's enough to make
applet.py exit.

I think that means applet.py needs some other (additional) way of being told
when to exit. How do other applications do it? XSMP?