tcp: huge rrset causes servfail (instead of useless tc bit)

src/knot/nameserver/internet.c

@@ -140,6 +140,9 @@ static int put_answer(knot_pkt_t *pkt, uint16_t type, struct query_data *qdata)
 		compr_hint = KNOT_COMPR_HINT_QNAME;
 	}
 
+	unsigned put_rr_flags = (qdata->param->proc_flags & NS_QUERY_LIMIT_SIZE) ?
+	                        KNOT_PF_NULL : KNOT_PF_NOTRUNC;
+
 	int ret = KNOT_EOK;
 	switch (type) {
 	case KNOT_RRTYPE_ANY: /* Append all RRSets. */ {
@@ -154,7 +157,7 @@ static int put_answer(knot_pkt_t *pkt, uint16_t type, struct query_data *qdata)
 		for (unsigned i = 0; i < qdata->node->rrset_count; ++i) {
 			rrset = node_rrset_at(qdata->node, i);
 			ret = process_query_put_rr(pkt, qdata, &rrset, NULL,
-			                           compr_hint, 0);
+			                           compr_hint, put_rr_flags);
 			if (ret != KNOT_EOK) {
 				break;
 			}
@@ -166,7 +169,7 @@ static int put_answer(knot_pkt_t *pkt, uint16_t type, struct query_data *qdata)
 		if (!knot_rrset_empty(&rrset)) {
 			knot_rrset_t rrsigs = node_rrset(qdata->node, KNOT_RRTYPE_RRSIG);
 			ret = process_query_put_rr(pkt, qdata, &rrset, &rrsigs,
-			                           compr_hint, 0);
+			                           compr_hint, put_rr_flags);
 		}
 		break;
 	}
@@ -367,7 +370,7 @@ static int name_found(knot_pkt_t *pkt, struct query_data *qdata)
 	uint16_t old_rrcount = pkt->rrset_count;
 	int ret = put_answer(pkt, qtype, qdata);
 	if (ret != KNOT_EOK) {
-		if (ret == KNOT_ESPACE) {
+		if (ret == KNOT_ESPACE && (qdata->param->proc_flags & NS_QUERY_LIMIT_SIZE)) {
 			return TRUNC;
 		} else {
 			return ERROR;