[gnome-settings-daemon] media-keys: Don't crash when there are no listeners

[Bastien Nocera <hadess src gnome org>]

commit 0760395d13348df88e742198ff3109d3f5d7a779
Author: Bastien Nocera <hadess hadess net>
Date:   Mon Nov 15 17:29:55 2010 +0000

    media-keys: Don't crash when there are no listeners
    
    No listening application means no application, and GVariant doesn't
    like NULL when it should be an empty string.

 plugins/media-keys/gsd-media-keys-manager.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/plugins/media-keys/gsd-media-keys-manager.c b/plugins/media-keys/gsd-media-keys-manager.c
index 1d6afd8..2cc9ce5 100644
--- a/plugins/media-keys/gsd-media-keys-manager.c
+++ b/plugins/media-keys/gsd-media-keys-manager.c
@@ -884,6 +884,8 @@ gsd_media_player_key_pressed (GsdMediaKeysManager *manager,
         gboolean    have_listeners;
         GError     *error = NULL;
 
+        g_return_val_if_fail (key != NULL, FALSE);
+
         g_debug ("Media key '%s' pressed", key);
 
         have_listeners = (manager->priv->media_players != NULL);
@@ -897,7 +899,7 @@ gsd_media_player_key_pressed (GsdMediaKeysManager *manager,
                                            GSD_MEDIA_KEYS_DBUS_PATH,
                                            GSD_MEDIA_KEYS_DBUS_NAME,
                                            "MediaPlayerKeyPressed",
-                                           g_variant_new ("(ss)", application, key),
+                                           g_variant_new ("(ss)", application ? application : "", key),
                                            &error) == FALSE) {
                 g_debug ("Error emitting signal: %s", error->message);
                 g_error_free (error);