NF_NODEST
n->n_flags &= ~NF_NODEST;
if (from->n_flags & (NF_NODEST|NF_MARK|NF_ACYCLIC))
if ((*np)->n_flags & (NF_MARK|NF_ACYCLIC|NF_NODEST))
(*np)->n_flags |= NF_NODEST;