[gnome-settings-daemon] media-keys: Fix crash when disabling plugin

[Bastien Nocera <hadess src gnome org>]

commit 6a81d4ad4c2a48b3ed034a111d4eb0740b7af1a5
Author: Bastien Nocera <hadess hadess net>
Date:   Mon May 26 14:26:17 2014 +0200

    media-keys: Fix crash when disabling plugin
    
    When the "active" plugin changes, or there are no keys captured yet,
    exit out of gsettings_changed_cb().

 plugins/media-keys/gsd-media-keys-manager.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/plugins/media-keys/gsd-media-keys-manager.c b/plugins/media-keys/gsd-media-keys-manager.c
index f237573..08c68d2 100644
--- a/plugins/media-keys/gsd-media-keys-manager.c
+++ b/plugins/media-keys/gsd-media-keys-manager.c
@@ -582,8 +582,14 @@ gsettings_changed_cb (GSettings           *settings,
         if (g_str_equal (settings_key, "max-screencast-length"))
                return;
 
+       /* Handled by the core */
+        if (g_str_equal (settings_key, "active"))
+                return;
 
         /* Find the key that was modified */
+        if (manager->priv->keys == NULL)
+                return;
+
         for (i = 0; i < manager->priv->keys->len; i++) {
                 MediaKey *key;