zone: fix double free when loading zone with journal

src/knot/updates/apply.c

@@ -378,7 +378,7 @@ int apply_replace_soa(apply_ctx_t *ctx, changeset_t *chset)
 
 	// Check for SOA with proper serial but different rdata.
 	if (node_rrtype_exists(contents->apex, KNOT_RRTYPE_SOA)) {
-		return KNOT_EINVAL;
+		return KNOT_EZONEINVAL;
 	}
 
 	return apply_add_rr(ctx, chset->soa_to);
@@ -483,17 +483,11 @@ int apply_changesets_directly(apply_ctx_t *ctx, list_t *chsets)
 	WALK_LIST(set, *chsets) {
 		int ret = apply_single(ctx, set);
 		if (ret != KNOT_EOK) {
-			update_rollback(ctx);
 			return ret;
 		}
 	}
 
-	int ret = zone_contents_adjust_full(ctx->contents);
-	if (ret != KNOT_EOK) {
-		update_rollback(ctx);
-	}
-
-	return ret;
+	return zone_contents_adjust_full(ctx->contents);
 }
 
 int apply_changeset_directly(apply_ctx_t *ctx, changeset_t *ch)

src/knot/updates/apply.h

@@ -129,6 +129,8 @@ int apply_changeset(apply_ctx_t *ctx, zone_t *zone, changeset_t *ch,
 /*!
  * \brief Applies changesets directly to the zone, without copying it.
  *
+ * \warning Modified zone is in inconsitent state after error and should be freed.
+ *
  * \param ctx     Apply context.
  * \param chsets  List of changesets to be applied to the zone.
  *

src/knot/zone/zone-load.c

@@ -136,7 +136,7 @@ int zone_load_journal(conf_t *conf, zone_t *zone, zone_contents_t *contents)
 		log_zone_info(zone->name, "changes from journal applied %u -> %u",
 		              serial, zone_contents_serial(contents));
 	} else {
-		log_zone_error(zone->name, "changes from journal applied %u -> %u (%s)",
+		log_zone_error(zone->name, "failed to apply journal changes %u -> %u (%s)",
 		               serial, zone_contents_serial(contents),
 		               knot_strerror(ret));
 	}

src/knot/zone/zone-load.h

@@ -42,6 +42,8 @@ int zone_load_check(conf_t *conf, zone_contents_t *contents);
 /*!
  * \brief Update zone contents from the journal.
  *
+ * \warning If error, the zone is in inconsitent state and should be freed.
+ *
  * \param conf
  * \param zone
  * \param contents