maybe_ok
if (n < 0 || !maybe_ok(pvt->res, bp, name_ok)) {
if (n < 0 || !maybe_ok(pvt->res, bp, name_ok)) {
if (n < 0 || !maybe_ok(pvt->res, tbuf, name_ok)) {
#define maybe_hnok(res, hn) maybe_ok((res), (hn), res_hnok)
#define maybe_dnok(res, dn) maybe_ok((res), (dn), res_dnok)