Bug#897221: Session logout doesn't TERMinate all processes

[Didier 'OdyX' Raboud <odyx@debian.org>]

Package: sddm
Version: 0.17.0-1
Severity: important
Tags: upstream

I routinely run two sessions in parallel (pro & private); and I noticed that
sddm (which I assume is handling the logind session) doesn't coherently
TERMinate (or KILL after some delay) processes from a logged-out session.

Some of these consume ressources (akonadiserver is the usual culprit), but more
importantly; keeping these alive will  break subsequent sessions for the same
user (plasma, akonadi, etc).

Running:
	# loginctl terminate-user <zombie>
circumvents the issue, but that should really be done by the login manager.

Please tell me if there's something I can do to help here.

Cheers,
OdyX

-- System Information:
Debian Release: buster/sid
  APT prefers buildd-unstable
  APT policy: (990, 'buildd-unstable'), (500, 'unstable-debug'), (500, 'oldstable-proposed-updates'), (500, 'unstable'), (500, 'testing'), (500, 'stable'), (100, 'experimental'), (1, 'experimental-debug')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.15.0-3-amd64 (SMP w/4 CPU cores)
Locale: LANG=fr_CH.UTF-8, LC_CTYPE=fr_CH.UTF-8 (charmap=UTF-8), LANGUAGE=fr_CH:fr (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages sddm depends on:
ii  adduser                 3.117
ii  debconf [debconf-2.0]   1.5.66
ii  libc6                   2.27-3
ii  libgcc1                 1:8-20180425-1
ii  libpam0g                1.1.8-3.7
ii  libqt5core5a            5.10.1+dfsg-5
ii  libqt5dbus5             5.10.1+dfsg-5
ii  libqt5gui5              5.10.1+dfsg-5
ii  libqt5network5          5.10.1+dfsg-5
ii  libqt5qml5              5.10.1-4
ii  libqt5quick5            5.10.1-4
ii  libstdc++6              8-20180425-1
ii  libsystemd0             238-4
ii  libxcb-xkb1             1.13-1
ii  libxcb1                 1.13-1
ii  qml-module-qtquick2     5.10.1-4
ii  x11-common              1:7.7+19
ii  xserver-xorg [xserver]  1:7.7+19
ii  xvfb [xserver]          2:1.19.6-1

Versions of packages sddm recommends:
ii  libpam-systemd                  238-4
ii  sddm-theme-breeze [sddm-theme]  4:5.12.4-1

Versions of packages sddm suggests:
ii  libpam-kwallet5           5.12.1-1
pn  qtvirtualkeyboard-plugin  <none>

-- debconf information:
  sddm/daemon_name: /usr/bin/sddm
* shared/default-x-display-manager: sddm