RACK_HAS_SYN
if (rsm->r_flags & RACK_HAS_SYN) {
rsm->r_flags &= ~RACK_HAS_SYN;
rsm->r_flags |= RACK_HAS_SYN;
if (nrsm->r_flags & RACK_HAS_SYN)
nrsm->r_flags &= ~RACK_HAS_SYN;
(rsm->r_flags & (RACK_HAS_SYN|RACK_HAS_FIN))),
rsm->r_flags |= RACK_HAS_SYN;