Bug#810941: "systemctl stop gdm3" leaves session for Debian-gdm user (user-113.slice) running

[Josh Triplett]

Package: gdm3
Version: 3.18.2-1
Severity: normal

Recently (not sure when this changed), running "systemctl stop gdm3" no
longer stops all gdm3-related processes; it leaves portions of the
greeter session running under "user-113.slice", running as the
Debian-gdm user.

This breaks "systemctl restart gdm3" and similar mechanisms.  Currently,
to fully restart gdm3, I have to stop gdm3, stop user-113.slice, and
then start gdm3 again.

-- System Information:
Debian Release: stretch/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.3.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages gdm3 depends on:
ii  accountsservice                       0.6.40-3
ii  adduser                               3.113+nmu3
ii  dconf-cli                             0.24.0-2
ii  dconf-gsettings-backend               0.24.0-2
ii  debconf [debconf-2.0]                 1.5.58
ii  gir1.2-gdm-1.0                        3.18.2-1
ii  gnome-session [x-session-manager]     3.18.1.2-1
ii  gnome-session-bin                     3.18.1.2-1
ii  gnome-settings-daemon                 3.18.2-1
ii  gnome-shell                           3.18.3-2
ii  gnome-terminal [x-terminal-emulator]  3.18.2-1
ii  gsettings-desktop-schemas             3.18.1-1
ii  libaccountsservice0                   0.6.40-3
ii  libaudit1                             1:2.4.5-1
ii  libc6                                 2.21-6
ii  libcanberra-gtk3-0                    0.30-2.1
ii  libcanberra0                          0.30-2.1
ii  libgdk-pixbuf2.0-0                    2.32.3-1
ii  libgdm1                               3.18.2-1
ii  libglib2.0-0                          2.46.2-3
ii  libglib2.0-bin                        2.46.2-3
ii  libgtk-3-0                            3.18.6-1
ii  libpam-modules                        1.1.8-3.2
ii  libpam-runtime                        1.1.8-3.2
ii  libpam-systemd                        228-4
ii  libpam0g                              1.1.8-3.2
ii  librsvg2-common                       2.40.13-1
ii  libselinux1                           2.4-3
ii  libsystemd0                           228-4
ii  libwrap0                              7.6.q-25
ii  libx11-6                              2:1.6.3-1
ii  libxau6                               1:1.0.8-1
ii  libxdmcp6                             1:1.1.2-1
ii  lsb-base                              9.20160110
ii  metacity [x-window-manager]           1:3.18.1-1
ii  mutter [x-window-manager]             3.18.2-1
ii  policykit-1                           0.105-14
ii  ucf                                   3.0031
ii  x11-common                            1:7.7+12
ii  x11-xserver-utils                     7.7+5

Versions of packages gdm3 recommends:
ii  at-spi2-core    2.18.3-3
ii  desktop-base    8.0.2
ii  x11-xkb-utils   7.7+2
pn  xserver-xephyr  <none>
ii  xserver-xorg    1:7.7+12
ii  zenity          3.18.1.1-1

Versions of packages gdm3 suggests:
ii  gnome-orca            3.18.2-1
ii  libpam-gnome-keyring  3.18.3-1

-- Configuration Files:
/etc/gdm3/daemon.conf changed:
[daemon]
AutomaticLoginEnable = true
AutomaticLogin = josh
[security]
[xdmcp]
[greeter]
[chooser]
[debug]


-- debconf information:
  gdm3/daemon_name: /usr/sbin/gdm3
* shared/default-x-display-manager: gdm3