0002-Lock-subscription-when-altering-it.patch

From 005eeb820f4e0528513744136582c4489e2429e3 Mon Sep 17 00:00:00 2001
From: Petr Jelinek <pjmodos@pjmodos.net>
Date: Wed, 14 Jun 2017 08:14:20 +0200
Subject: [PATCH 2/2] Lock subscription when altering it

---
 src/backend/commands/subscriptioncmds.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index 14c8f3f..e0ec8ea 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -642,6 +642,13 @@ AlterSubscription(AlterSubscriptionStmt *stmt)
 					   stmt->subname);
 
 	subid = HeapTupleGetOid(tup);
+
+	/*
+	 * Lock the subscription so nobody else can do anything with it (including
+	 * the replication workers).
+	 */
+	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+
 	sub = GetSubscription(subid, false);
 
 	/* Form a new tuple. */
-- 
2.7.4