sr_srfpp
srp->sr_srfpp != &(srfp->srf_next)) {
*(srp->sr_srfpp) = srfp;
srp->sr_srfpp = &(srfp->srf_next);
srp->sr_srfpp == &(srfp->srf_next));
srfp = *(srp->sr_srfpp);
srp->sr_srfpp = &(srp->sr_srfp);
srp->sr_srfpp = &(srp->sr_srfp);
srp->sr_srfpp = NULL;
srp->sr_srfpp = NULL;