rem: if (gtk_playlist_has_previous_mrl (totem->playlist) == FALSE)
add: if (totem_playing_dvd (totem) == FALSE && gtk_playlist_has_previous_mrl (totem->playlist) == FALSE)
context: totem_action_previous (Totem *totem){	char *mrl;	if (gtk_playlist_has_previous_mrl (totem->playlist) == FALSE)		return;	gtk_playlist_set_previous (totem->playlist);	update_buttons (totem);	mrl = gtk_playlist_get_current_mrl (totem->playlist);	totem_action_set_mrl (totem, mrl);	totem_action_play (totem, 0);	g_free (mrl);}