ixfr: rewrite QTYPE for AXFR fallback

src/knot/nameserver/ixfr.c

@@ -567,6 +567,7 @@ int ixfr_query(knot_pkt_t *pkt, struct query_data *qdata)
 	int ret = KNOT_EOK;
 	struct timeval now = {0};
 	struct ixfr_proc *ixfr = (struct ixfr_proc*)qdata->ext;
+	knot_pkt_t *query = qdata->query;
 
 	/* If IXFR is disabled, respond with SOA. */
 	if (qdata->param->proc_flags & NS_QUERY_NO_IXFR) {
@@ -589,6 +590,10 @@ int ixfr_query(knot_pkt_t *pkt, struct query_data *qdata)
 		case KNOT_ERANGE:   /* No history -> AXFR. */
 		case KNOT_ENOENT:
 			IXFROUT_LOG(LOG_INFO, "Incomplete history, fallback to AXFR.");
+			knot_pkt_clear(pkt);
+			knot_pkt_put_question(pkt, knot_pkt_qname(query),
+			                      knot_pkt_qclass(query),
+			                      KNOT_RRTYPE_AXFR);
 			qdata->packet_type = KNOT_QUERY_AXFR; /* Solve as AXFR. */
 			return axfr_query_process(pkt, qdata);
 		default:            /* Server errors. */