control/media_descriptor.c: Set the media descriptor of the subitems.

src/control/media_descriptor.c

@@ -88,7 +88,10 @@ static void input_item_subitem_added( const vlc_event_t *p_event,
 
     /* Add this to our media list */
     if( !p_md->p_subitems )
+    {
         p_md->p_subitems = libvlc_media_list_new( p_md->p_libvlc_instance, NULL );
+        libvlc_media_list_set_media_descriptor( p_md->p_subitems, p_md, NULL );
+    }
     if( p_md->p_subitems )
     {
         libvlc_media_list_add_media_descriptor( p_md->p_subitems, p_md_child, NULL );