RES_F_EDNS0ERR
if (n > 0 && (statp->_flags & RES_F_EDNS0ERR) == 0 &&
((oflags ^ statp->_flags) & RES_F_EDNS0ERR) != 0) {
statp->_flags |= RES_F_EDNS0ERR;
if (n > 0 && (statp->_flags & RES_F_EDNS0ERR) == 0 &&
((oflags ^ statp->_flags) & RES_F_EDNS0ERR) != 0) {
statp->_flags |= RES_F_EDNS0ERR;
statp->_flags |= RES_F_EDNS0ERR;