From 84c6c4cd7612847326c7121f3b20a31cc846ef92 Mon Sep 17 00:00:00 2001
From: Michael Paquier <michael@paquier.xyz>
Date: Mon, 19 Jun 2023 14:22:13 +0900
Subject: [PATCH] Fix promotion with prepared transactions and the last partial
 segment

---
 src/backend/access/transam/xlog.c   | 107 +++++++++++++++-------------
 src/test/recovery/t/009_twophase.pl |   4 +-
 2 files changed, 59 insertions(+), 52 deletions(-)

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 6c2181ce8e..c72b6439a0 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -8016,6 +8016,62 @@ StartupXLOG(void)
 			CreateCheckPoint(CHECKPOINT_END_OF_RECOVERY | CHECKPOINT_IMMEDIATE);
 	}
 
+	/*
+	 * Preallocate additional log files, if wanted.
+	 */
+	PreallocXlogFiles(EndOfLog);
+
+	/*
+	 * Okay, we're officially UP.
+	 */
+	InRecovery = false;
+
+	/* start the archive_timeout timer and LSN running */
+	XLogCtl->lastSegSwitchTime = (pg_time_t) time(NULL);
+	XLogCtl->lastSegSwitchLSN = EndOfLog;
+
+	/* also initialize latestCompletedXid, to nextXid - 1 */
+	LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
+	ShmemVariableCache->latestCompletedXid = ShmemVariableCache->nextXid;
+	FullTransactionIdRetreat(&ShmemVariableCache->latestCompletedXid);
+	LWLockRelease(ProcArrayLock);
+
+	/*
+	 * Start up subtrans, if not already done for hot standby.  (commit
+	 * timestamps are started below, if necessary.)
+	 */
+	if (standbyState == STANDBY_DISABLED)
+		StartupSUBTRANS(oldestActiveXID);
+
+	/*
+	 * Perform end of recovery actions for any SLRUs that need it.
+	 */
+	TrimCLOG();
+	TrimMultiXact();
+
+	/*
+	 * Reload shared-memory state for prepared transactions.  This needs
+	 * to happen before renaming the last partial segment of the old
+	 * timeline as it may be possible that we have to recovery some
+	 * transactions from it.
+	 */
+	RecoverPreparedTransactions();
+
+	/* Shut down xlogreader */
+	if (readFile >= 0)
+	{
+		close(readFile);
+		readFile = -1;
+	}
+	XLogReaderFree(xlogreader);
+
+	/*
+	 * If any of the critical GUCs have changed, log them before we allow
+	 * backends to write WAL.
+	 */
+	LocalSetXLogInsertAllowed();
+	XLogReportParameters();
+
 	if (ArchiveRecoveryRequested)
 	{
 		/*
@@ -8097,57 +8153,6 @@ StartupXLOG(void)
 		}
 	}
 
-	/*
-	 * Preallocate additional log files, if wanted.
-	 */
-	PreallocXlogFiles(EndOfLog);
-
-	/*
-	 * Okay, we're officially UP.
-	 */
-	InRecovery = false;
-
-	/* start the archive_timeout timer and LSN running */
-	XLogCtl->lastSegSwitchTime = (pg_time_t) time(NULL);
-	XLogCtl->lastSegSwitchLSN = EndOfLog;
-
-	/* also initialize latestCompletedXid, to nextXid - 1 */
-	LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
-	ShmemVariableCache->latestCompletedXid = ShmemVariableCache->nextXid;
-	FullTransactionIdRetreat(&ShmemVariableCache->latestCompletedXid);
-	LWLockRelease(ProcArrayLock);
-
-	/*
-	 * Start up subtrans, if not already done for hot standby.  (commit
-	 * timestamps are started below, if necessary.)
-	 */
-	if (standbyState == STANDBY_DISABLED)
-		StartupSUBTRANS(oldestActiveXID);
-
-	/*
-	 * Perform end of recovery actions for any SLRUs that need it.
-	 */
-	TrimCLOG();
-	TrimMultiXact();
-
-	/* Reload shared-memory state for prepared transactions */
-	RecoverPreparedTransactions();
-
-	/* Shut down xlogreader */
-	if (readFile >= 0)
-	{
-		close(readFile);
-		readFile = -1;
-	}
-	XLogReaderFree(xlogreader);
-
-	/*
-	 * If any of the critical GUCs have changed, log them before we allow
-	 * backends to write WAL.
-	 */
-	LocalSetXLogInsertAllowed();
-	XLogReportParameters();
-
 	/*
 	 * Local WAL inserts enabled, so it's time to finish initialization of
 	 * commit timestamp.
diff --git a/src/test/recovery/t/009_twophase.pl b/src/test/recovery/t/009_twophase.pl
index 900d181788..5a4178cd46 100644
--- a/src/test/recovery/t/009_twophase.pl
+++ b/src/test/recovery/t/009_twophase.pl
@@ -32,7 +32,9 @@ sub configure_and_reload
 
 # Setup london node
 my $node_london = get_new_node("london");
-$node_london->init(allows_streaming => 1);
+# Archiving is used to force tests with .partial segment creations
+# done at the end of recovery.
+$node_london->init(allows_streaming => 1, has_archiving => 1);
 $node_london->append_conf(
 	'postgresql.conf', qq(
 	max_prepared_transactions = 10
-- 
2.40.1