SS_RESTORE_CURR
SS_RESTORE_CURR|SS_FORCE);
SS_RESTORE_CURR|SS_FORCE);
setsig(p, f, SS_RESTORE_CURR|SS_USER);
setsig(p, SIG_IGN, SS_RESTORE_CURR);
setsig(p, SIG_IGN, SS_RESTORE_CURR);
setsig(&sigtraps[SIGPIPE], SIG_DFL, SS_RESTORE_CURR);
case SS_RESTORE_CURR: /* leave things as they currently are */