Bug#866507: accountsservice postinst script can cause hang if the dpkg output is captured

[Michael Schaller]

Package: accountsservice
Version: 0.6.43-1
Severity: normal

Dear Maintainer,

The accountsservice postinst maintainer script has this line:
[ -z "$pid" ] || /usr/lib/accountsservice/accounts-daemon & >/dev/null || true # will trigger through D-Bus activation

This line is problematic if a process captures the dpkg output as the spawned /usr/lib/accountsservice/accounts-daemon doesn't properly detach and hence the capturing process will never receive an EOF on dpkg's stdout/stderr.
To fix the problem the line in the accountsservice postinst maintainer script should be:
[ -z "$pid" ] || setsid /usr/lib/accountsservice/accounts-daemon >/dev/null 2>&1 </dev/null & || true # will trigger through D-Bus activation

Alternatively one can just remove the line as accounts-daemon will be started via D-Bus if needed (as the comment on that line already states).

Best,

Michael Schaller

-- System Information:
Debian Release: 9.0
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.9.0-3-amd64 (SMP w/12 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US: (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash
Init: systemd (via /run/systemd/system)

Versions of packages accountsservice depends on:
ii  dbus                   1.10.18-1
ii  init-system-helpers    1.48
ii  libaccountsservice0    0.6.43-1
ii  libc6                  2.24-11
ii  libglib2.0-0           2.50.3-2
ii  libpolkit-gobject-1-0  0.105-18

accountsservice recommends no packages.

Versions of packages accountsservice suggests:
pn  gnome-control-center  <none>

-- no debconf information