[gnome-control-center] datetime: Don't crash when g-s-d is badly installed

[hadess src gnome org]

commit de278d3a857374a8f9cb8af3db211e9f87089049
Author: Bastien Nocera <hadess hadess net>
Date:   Wed Feb 2 11:42:31 2011 +0000

    datetime: Don't crash when g-s-d is badly installed
    
    And require a newer gnome-settings-daemon to avoid those problems.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=641232

 configure.ac                        |    2 +-
 panels/datetime/cc-datetime-panel.c |    6 ++++++
 2 files changed, 7 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index f2f0473..65fc2f1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -94,7 +94,7 @@ PKG_CHECK_MODULES(CAPPLET, $COMMON_MODULES)
 PKG_CHECK_MODULES(GNOMECC_SHELL, $COMMON_MODULES libgnome-menu gio-unix-2.0)
 PKG_CHECK_MODULES(DBUS, dbus-1 dbus-glib-1)
 PKG_CHECK_MODULES(GNOME_DESKTOP, gnome-desktop-3.0)
-PKG_CHECK_MODULES(GSD_DBUS, gnome-settings-daemon >= 2.91.2)
+PKG_CHECK_MODULES(GSD_DBUS, gnome-settings-daemon >= 2.91.9)
 PKG_CHECK_MODULES(GIO, gio-2.0 gio-unix-2.0)
 PKG_CHECK_MODULES(XML, libxml-2.0)
 PKG_CHECK_MODULES(UPOWER, upower-glib >= 0.9.1)
diff --git a/panels/datetime/cc-datetime-panel.c b/panels/datetime/cc-datetime-panel.c
index 03b6188..d980718 100644
--- a/panels/datetime/cc-datetime-panel.c
+++ b/panels/datetime/cc-datetime-panel.c
@@ -863,6 +863,12 @@ cc_date_time_panel_init (CcDateTimePanel *self)
 
   /* add the lock button */
   permission = polkit_permission_new_sync ("org.gnome.settingsdaemon.datetimemechanism.configure", NULL, NULL, NULL);
+  if (permission == NULL)
+    {
+      g_warning ("Your system does not have the '%s' PolicyKit files installed. Please check your installation",
+                 "org.gnome.settingsdaemon.datetimemechanism.configure");
+      return;
+    }
 
   /* DtLockButton takes ownership of the permission */
   lockbutton = dt_lock_button_new (permission);