From: Michael Paquier <michael@paquier.xyz>
Date: Sat, 27 Dec 2025 08:23:54 +0000 (+0900)
Subject: Fix pg_stat_get_backend_activity() to use multi-byte truncated result
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c48829ed8308e9e1767e5ce4d883996348af5b68;p=thirdparty%2Fpostgresql.git

Fix pg_stat_get_backend_activity() to use multi-byte truncated result

pg_stat_get_backend_activity() calls pgstat_clip_activity() to ensure
that the reported query string is correctly truncated when it finishes
with an incomplete multi-byte sequence.  However, the result returned by
the function was not what pgstat_clip_activity() generated, but the
non-truncated, original, contents from PgBackendStatus.st_activity_raw.

Oversight in 54b6cd589ac2, so backpatch all the way down.

Author: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/CAEoWx2mDzwc48q2EK9tSXS6iJMJ35wvxNQnHX+rXjy5VgLvJQw@mail.gmail.com
Backpatch-through: 14
---

diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index 05e7a048075..200daceee04 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -762,7 +762,7 @@ pg_stat_get_backend_activity(PG_FUNCTION_ARGS)
 		activity = beentry->st_activity_raw;
 
 	clipped_activity = pgstat_clip_activity(activity);
-	ret = cstring_to_text(activity);
+	ret = cstring_to_text(clipped_activity);
 	pfree(clipped_activity);
 
 	PG_RETURN_TEXT_P(ret);