R4INCACHEPURGE
if (mtime_changed && !(rp->r_flags & R4INCACHEPURGE)) {
rp->r_flags |= R4INCACHEPURGE;
if ((rp->r_flags & R4INCACHEPURGE) && cachepurge_set) {
rp->r_flags &= ~R4INCACHEPURGE;
while (rp->r_flags & R4INCACHEPURGE) {