From 17b04a15806d8e8b4cc3013244f4837c02d6baf4 Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Tue, 6 May 2014 15:14:51 +0300
Subject: [PATCH] Fix use of free in walsender error handling after a sysid
 mismatch.

Found via valgrind. The bug exists since the introduction of the walsender,
so backpatch to 9.0.

Andres Freund
---
 src/backend/replication/libpqwalreceiver/libpqwalreceiver.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
index 979b66b300a..5340ed064cf 100644
--- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
+++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -135,6 +135,7 @@ libpqrcv_connect(char *conninfo, XLogRecPtr startpoint)
 			 GetSystemIdentifier());
 	if (strcmp(primary_sysid, standby_sysid) != 0)
 	{
+		primary_sysid = pstrdup(primary_sysid);
 		PQclear(res);
 		ereport(ERROR,
 				(errmsg("database system identifier differs between the primary and standby"),