[gnome-screensaver] gnome-screensaver-command: don't activate screensaver for --query

[Ray Strode <halfline src gnome org>]

commit a37f531e5ba968bea445e82dbc418d8b7ced219c
Author: Ray Strode <rstrode redhat com>
Date:   Tue Oct 19 13:55:19 2010 -0400

    gnome-screensaver-command: don't activate screensaver for --query
    
    Now that gnome-screensaver is auto activated, we need to take care
    not to activate it for --query (since --query is supposed to query
    if gnome-screensaver is running, not start it).
    
    https://bugzilla.gnome.org/show_bug.cgi?id=629740

 src/gnome-screensaver-command.c |   21 +++++++++++++++++++++
 1 files changed, 21 insertions(+), 0 deletions(-)
---
diff --git a/src/gnome-screensaver-command.c b/src/gnome-screensaver-command.c
index e94a7cb..dfc6a62 100644
--- a/src/gnome-screensaver-command.c
+++ b/src/gnome-screensaver-command.c
@@ -270,6 +270,22 @@ oom:
 }
 
 static gboolean
+screensaver_is_running (DBusConnection *connection)
+{
+        DBusError               error;
+        gboolean                exists;
+
+        g_return_val_if_fail (connection != NULL, FALSE);
+
+        dbus_error_init (&error);
+        exists = dbus_bus_name_has_owner (connection, GS_SERVICE, &error);
+        if (dbus_error_is_set (&error))
+                dbus_error_free (&error);
+
+        return exists;
+}
+
+static gboolean
 do_command (DBusConnection *connection)
 {
         DBusMessage *reply;
@@ -284,6 +300,11 @@ do_command (DBusConnection *connection)
                 DBusMessageIter array;
                 dbus_bool_t     v;
 
+                if (!screensaver_is_running (connection)) {
+                        g_message ("Screensaver is not running!");
+                        goto done;
+                }
+
                 reply = screensaver_send_message_void (connection, "GetActive", TRUE);
                 if (! reply) {
                         g_message ("Did not receive a reply from the screensaver.");