mandatory semantic checks for axfr and ixfr transfer

src/knot/nameserver/axfr.c

@@ -323,6 +323,16 @@ static int axfr_answer_finalize(struct answer_data *adata)
 		return rc;
 	}
 
+	err_handler_t handler;
+	err_handler_init(&handler);
+	rc = zone_do_sem_checks(proc->contents, false, &handler);
+	err_handler_log_errors(&handler);
+	err_handler_deinit(&handler);
+
+	if (rc != KNOT_EOK) {
+		return rc;
+	}
+
 	/* Switch contents. */
 	zone_t *zone = adata->param->zone;
 	zone_contents_t *old_contents =

src/knot/nameserver/ixfr.c

@@ -389,12 +389,15 @@ static int ixfrin_finalize(struct answer_data *adata)
 		return ret;
 	}
 
-	err_handler_t err_handler;
-	err_handler_init(&err_handler);
-	ret = zone_do_sem_checks(new_contents, 0, &err_handler, NULL, NULL);
+	err_handler_t handler;
+	err_handler_init(&handler);
+	ret = zone_do_sem_checks(new_contents, false, &handler);
+	err_handler_log_errors(&handler);
+	err_handler_deinit(&handler);
+
 	if (ret != KNOT_EOK) {
 		IXFRIN_LOG(LOG_WARNING, "failed to apply changes to zone (%s)",
-		           knot_strerror(KNOT_ESEMCHECK));
+		           knot_strerror(ret));
 		update_rollback(&a_ctx);
 		update_free_zone(&new_contents);
 		return ret;