}
/* Update SACK list if need be */
- if (tcp_opts_sack_permitted (&tc->rcv_opts))
+ if (tcp_opts_sack_permitted (&tc->rcv_opts) && vec_len (tc->snd_sacks))
{
/* Remove SACK blocks that have been delivered */
tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);