From 93dc1ace2007fe7c1103ccda3d7bc13b4eb4352f Mon Sep 17 00:00:00 2001
From: Fujii Masao <fujii@postgresql.org>
Date: Mon, 6 Apr 2026 23:04:18 +0900
Subject: [PATCH] Release postmaster working memory context in slotsync worker

Child processes do not need the postmaster's working memory context and
normally release it at the start of their main entry point. However,
the slotsync worker forgot to do so.

This commit makes the slotsync worker release the postmaster's working
memory context at startup, preventing unintended use.

Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Tiancheng Ge <getiancheng_2012@163.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/CAHGQGwHO05JaUpgKF8FBDmPdBUJsK22axRRcgmAUc2Jyi8OK8g@mail.gmail.com
---
 src/backend/replication/logical/slotsync.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/backend/replication/logical/slotsync.c b/src/backend/replication/logical/slotsync.c
index d615ff8a81c..8b53bd3ac7f 100644
--- a/src/backend/replication/logical/slotsync.c
+++ b/src/backend/replication/logical/slotsync.c
@@ -1494,6 +1494,13 @@ ReplSlotSyncWorkerMain(const void *startup_data, size_t startup_data_len)
 
 	Assert(startup_data_len == 0);
 
+	/* Release postmaster's working memory context */
+	if (PostmasterContext)
+	{
+		MemoryContextDelete(PostmasterContext);
+		PostmasterContext = NULL;
+	}
+
 	init_ps_display(NULL);
 
 	Assert(GetProcessingMode() == InitProcessing);