soa_rr_get_serial
data->newserial = soa_rr_get_serial(rr);
data->oldserial = soa_rr_get_serial(rr);
if(rr->type != TYPE_SOA && soa_rr_get_serial(rr) != data->newserial) {
if(rr->type != TYPE_SOA || soa_rr_get_serial(rr) != data->newserial) {
return soa_rr_get_serial(zone->soa_rrset->rrs[0]);