Fix executing invalidation messages generated by subtransactions during decoding.

This problem has been introduced by commit 272248a where we started
assigning the subtransactions to the top-level transaction when we mark
both the top-level transaction and its subtransactions as containing
catalog changes. After we assign subtransactions to the top-level
transaction, we were not allowed to execute any invalidations associated
with it when we decide to skip the transaction.

The reason to assign the subtransactions to the top-level transaction was
to avoid the assertion failure in AssertTXNLsnOrder() as they have the
same LSN when we sometimes start accumulating transaction changes for
partial transactions after the restart. Now that with commit 64ff0fe,
we skip this assertion check until we reach the LSN at which we start
decoding the contents of the transaction, so, there is no reason for such
an assignment anymore.

The assignment change was introduced in 15 and prior versions but this bug
doesn't exist in branches prior to 14 since we don't add invalidation
messages to subtransactions. We decided to backpatch through 11 for
consistency but not for 10 since its final release is near.

Reported-by: Kuroda Hayato
Author: Masahiko Sawada
Reviewed-by: Amit Kapila
Backpatch-through: 11
Discussion: https://postgr.es/m/TYAPR01MB58660803BCAA7849C8584AA4F57E9%40TYAPR01MB5866.jpnprd01.prod.outlook.com
Discussion: https://postgr.es/m/a89b46b6-0239-2fd5-71a9-b19b1f7a7145%40enterprisedb.com

Author: Amit Kapila

contrib/test_decoding/expected/catalog_change_snapshot.out

@@ -87,3 +87,48 @@ COMMIT
 stop    
 (1 row)
 
+
+starting permutation: s0_init s0_begin s0_savepoint s0_insert s1_checkpoint s1_get_changes s0_truncate s0_commit s0_begin s0_insert s1_checkpoint s1_get_changes s0_commit s1_get_changes
+step s0_init: SELECT 'init' FROM pg_create_logical_replication_slot('isolation_slot', 'test_decoding');
+?column?
+--------
+init    
+(1 row)
+
+step s0_begin: BEGIN;
+step s0_savepoint: SAVEPOINT sp1;
+step s0_insert: INSERT INTO tbl1 VALUES (1);
+step s1_checkpoint: CHECKPOINT;
+step s1_get_changes: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'skip-empty-xacts', '1', 'include-xids', '0');
+data
+----
+(0 rows)
+
+step s0_truncate: TRUNCATE tbl1;
+step s0_commit: COMMIT;
+step s0_begin: BEGIN;
+step s0_insert: INSERT INTO tbl1 VALUES (1);
+step s1_checkpoint: CHECKPOINT;
+step s1_get_changes: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'skip-empty-xacts', '1', 'include-xids', '0');
+data                                                         
+-------------------------------------------------------------
+BEGIN                                                        
+table public.tbl1: INSERT: val1[integer]:1 val2[integer]:null
+table public.tbl1: TRUNCATE: (no-flags)                      
+COMMIT                                                       
+(4 rows)
+
+step s0_commit: COMMIT;
+step s1_get_changes: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'skip-empty-xacts', '1', 'include-xids', '0');
+data                                                         
+-------------------------------------------------------------
+BEGIN                                                        
+table public.tbl1: INSERT: val1[integer]:1 val2[integer]:null
+COMMIT                                                       
+(3 rows)
+
+?column?
+--------
+stop    
+(1 row)
+

contrib/test_decoding/specs/catalog_change_snapshot.spec

@@ -53,3 +53,10 @@ permutation "s0_init" "s0_begin" "s0_savepoint" "s0_truncate" "s1_checkpoint" "s
 # transaction to do timetravel since one of its subtransactions has been marked as
 # containing catalog changes.
 permutation "s0_init" "s0_begin" "s0_savepoint" "s0_insert" "s1_checkpoint" "s1_get_changes" "s0_insert2" "s0_commit" "s0_begin" "s0_insert" "s1_checkpoint" "s1_get_changes" "s0_commit" "s1_get_changes"
+
+# The last decoding restarts from the first checkpoint and adds invalidation
+# messages generated by "s0_truncate" to the subtransaction. While
+# processing the commit record for the top-level transaction, we decide
+# to skip this xact but ensure that corresponding invalidation messages
+# get processed.
+permutation "s0_init" "s0_begin" "s0_savepoint" "s0_insert" "s1_checkpoint" "s1_get_changes" "s0_truncate" "s0_commit" "s0_begin" "s0_insert" "s1_checkpoint" "s1_get_changes" "s0_commit" "s1_get_changes"

src/backend/replication/logical/snapbuild.c

@@ -2120,9 +2120,6 @@ SnapBuildXidSetCatalogChanges(SnapBuild *builder, TransactionId xid, int subxcnt
 		ReorderBufferXidSetCatalogChanges(builder->reorder, xid, lsn);
 
 		for (int i = 0; i < subxcnt; i++)
-		{
-			ReorderBufferAssignChild(builder->reorder, xid, subxacts[i], lsn);
 			ReorderBufferXidSetCatalogChanges(builder->reorder, subxacts[i], lsn);
-		}
 	}
 }