cvs head bb_boxc question

in cvs head bb_boxc.c fn int route_incoming_to_boxc(Msg *msg)
{

I commented two lines out
    for(i = 0; i < list_len(smsbox_list); i++) {
 bc = list_get(smsbox_list, (i+b) % len);

  //      if (bc->boxc_id != NULL || bc->routable == 0)
***
  //          bc = NULL;
***

        if (bc != NULL && max_incoming_sms_qlength > 0 &&
            list_len(bc->incoming) > max_incoming_sms_qlength) {
            full_found = 1;
            bc = NULL;
        }

        if ((bc != NULL && best != NULL && bc->load < best->load) ||
             (bc != NULL && best == NULL)) {
     best = bc;
        }
    }


I was getting smsbox_list empty!
those two lines didn't make sense to me, can anyone explain this part of
code ?