SACK_NEWLOSS
((tp->t_rxtshift > 0) && (sack_changed == SACK_NEWLOSS))) &&
safe_ack = SEQ_GT(th->th_ack, tp->snd_una) && (sack_changed != SACK_NEWLOSS);
sack_changed = SACK_NEWLOSS;
sack_changed = SACK_NEWLOSS;
sack_changed = SACK_NEWLOSS;