commit ce5a67127223e99ffdbf9cb697537c689e2fe364
Author: Vincent Untz <vuntz@gnome.org>
Date:   Tue Sep 25 10:55:31 2012 +0200

    Fix same seat detection if built with systemd, but not booted with it
    
    If we haven't booted with systemd, then we can only assume it's always
    the same seat.
    
    Based on patch by Takashi Iwai <tiwai@suse.com>.
    
    https://bugzilla.novell.com/show_bug.cgi?id=769570

diff --git a/configure.ac b/configure.ac
index 994fd1a..93c715e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -145,7 +145,7 @@ AC_SUBST(LIBATASMART_CFLAGS)
 AC_SUBST(LIBATASMART_LIBS)
 
 PKG_CHECK_MODULES(LIBSYSTEMD_LOGIN,
-                  [libsystemd-login >= 44],
+                  [libsystemd-login >= 44 libsystemd-daemon],
                   have_libsystemd_login=yes,
                   have_libsystemd_login=no)
 AM_CONDITIONAL(HAVE_LIBSYSTEMD_LOGIN, test x$have_libsystemd_login = xyes)
diff --git a/src/udisksdaemonutil.c b/src/udisksdaemonutil.c
index ef925f5..69cd8a5 100644
--- a/src/udisksdaemonutil.c
+++ b/src/udisksdaemonutil.c
@@ -42,6 +42,7 @@
 #include "udiskslinuxdriveobject.h"
 
 #if defined(HAVE_LIBSYSTEMD_LOGIN)
+#include <systemd/sd-daemon.h>
 #include <systemd/sd-login.h>
 #endif
 
@@ -1021,6 +1022,10 @@ udisks_daemon_util_on_same_seat (UDisksDaemon          *daemon,
   UDisksObject *drive_object = NULL;
   UDisksDrive *drive = NULL;
 
+  /* if we haven't booted with systemd, assume it's always the same seat */
+  if (sd_booted () <= 0)
+    return TRUE;
+
   if (UDISKS_IS_LINUX_BLOCK_OBJECT (object))
     {
       UDisksLinuxBlockObject *linux_block_object;