Only start logind if dbus is installed

This fixes the noisy startup failure in environments without D-BUS, such as LXC
containers or servers.

Part of #772700, does not yet address the auto-VT issue

debian/changelog

@@ -5,8 +5,11 @@ systemd (215-12) UNRELEASED; urgency=medium
     (Part of #776546)
   * Actually install udev's README.Debian when building for Debian.
     (Closes: #776546)
+  * Only start logind if dbus is installed. This fixes the noisy startup
+    failure in environments without dbus such as LXC containers or servers.
+    (part of #772700)
 
- -- Martin Pitt <martin.pitt@ubuntu.com>  Fri, 30 Jan 2015 15:56:22 +0100
+ -- Martin Pitt <mpitt@debian.org>  Fri, 30 Jan 2015 15:56:22 +0100
 
 systemd (215-11) unstable; urgency=medium
 

debian/patches/Only-start-logind-if-D-BUS-is-installed.patch

+From: Martin Pitt <martin.pitt@ubuntu.com>
+Date: Mon, 9 Feb 2015 10:53:43 +0100
+Subject: Only start logind if dbus is installed
+
+logind fails to start in environments without dbus, such as LXC containers or
+servers. Add a startup condition to avoid the very noisy startup failure.
+
+Part of #772700
+---
+ units/systemd-logind.service.in | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/units/systemd-logind.service.in b/units/systemd-logind.service.in
+index c6cbd1c..ef68aa0 100644
+--- a/units/systemd-logind.service.in
++++ b/units/systemd-logind.service.in
+@@ -12,6 +12,7 @@ Documentation=http://www.freedesktop.org/wiki/Software/systemd/logind
+ Documentation=http://www.freedesktop.org/wiki/Software/systemd/multiseat
+ Wants=user.slice
+ After=nss-user-lookup.target user.slice
++ConditionFileIsExecutable=/usr/bin/dbus-daemon
+ 
+ # Ask for the dbus socket. If running over kdbus, the socket will
+ # not be actually used.

debian/patches/series

@@ -182,3 +182,4 @@ udev-re-enable-mount-propagation-for-udevd.patch
 Add-env-variable-for-machine-ID-path.patch
 Prefer-etc-X11-default-display-manager-if-present.patch
 Fix-usr-remount-failure-for-split-usr.patch
+Only-start-logind-if-D-BUS-is-installed.patch