Fix resource management bug with replication=database.

robertmhaas · robertmhaas · commit 3e0d80fd8d3d · 2020-04-03T22:28:37.000-04:00
Commit 0d8c9c1 allowed BASE_BACKUP to acquire a ResourceOwner without a transaction so that the backup manifest functionality could use a BufFile, but it overlooked the fact that when a walsender is used with replication=database, it might have a transaction in progress, because in that mode, SQL and replication commands can be mixed. Try to fix things up so that the two cleanup mechanisms don't conflict. Per buildfarm member serinus, which triggered the problem when CREATE_REPLICATION_SLOT failed from inside a transaction. It passed on the subsequent run, so evidently the failure doesn't happen every time.
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
@@ -315,7 +315,13 @@ WalSndErrorCleanup(void)
 
 	replication_active = false;
 
-	WalSndResourceCleanup(false);
+	/*
+	 * If there is a transaction in progress, it will clean up our
+	 * ResourceOwner, but if a replication command set up a resource owner
+	 * without a transaction, we've got to clean that up now.
+	 */
+	if (!IsTransactionOrTransactionBlock())
+		WalSndResourceCleanup(false);
 
 	if (got_STOPPING || got_SIGUSR2)
 		proc_exit(0);
