From 6e81fb936680797368272ebdee9dbfbbb41e257a Mon Sep 17 00:00:00 2001
From: Maksim Melnikov <m.melnikov@postgrespro.ru>
Date: Fri, 30 Jan 2026 11:27:24 +0300
Subject: [PATCH] pg_query_state code should be stable to the struct LOCKTAG
 extension.

LOCKTAG is used in hash calculations, so if new field is added to
LOCKTAG and this field is not initialized in pg_query_state internals,
as the result, the hashcode of LOCKTAG will have different values for
two independent calculations.
---
 pg_query_state.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pg_query_state.c b/pg_query_state.c
index 739a44e..a5e6fb9 100644
--- a/pg_query_state.c
+++ b/pg_query_state.c
@@ -419,6 +419,7 @@ void
 LockShmem(LOCKTAG *tag, uint32 key)
 {
 	LockAcquireResult result;
+	memset(tag, 0, sizeof(LOCKTAG));
 	tag->locktag_field1 = PG_QS_MODULE_KEY;
 	tag->locktag_field2 = key;
 	tag->locktag_field3 = 0;