From: Alexander Korotkov <akorotkov@postgresql.org>
Date: Sat, 13 Jun 2026 23:49:05 +0000 (+0300)
Subject: amcheck: Use correct varlena size accessor in bt_normalize_tuple()
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=da1eff08a5bedc4bea9f75c8412d877c5619afc0;p=thirdparty%2Fpostgresql.git

amcheck: Use correct varlena size accessor in bt_normalize_tuple()

bt_normalize_tuple() uses VARSIZE() to get the size of varlena, even though
it's not yet known, that it has a 4-byte header.  Fix this by replacing a
accessor with a universal VARSIZE_ANY().

Backpatch to all supported versions.

Reported-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/7ckc7oka4bvafkf5bwlqs6ygrhlsbhz25ppozfch7zbuxcx3rf%40e4pr4oqenalc
Author: Andrey Borodin <x4mmm@yandex-team.ru>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
Backpatch-through: 14
---

diff --git a/contrib/amcheck/verify_nbtree.c b/contrib/amcheck/verify_nbtree.c
index a5c62f2cb5c..3ef2d66f826 100644
--- a/contrib/amcheck/verify_nbtree.c
+++ b/contrib/amcheck/verify_nbtree.c
@@ -2891,7 +2891,7 @@ bt_normalize_tuple(BtreeCheckState *state, IndexTuple itup)
 							ItemPointerGetOffsetNumber(&(itup->t_tid)),
 							RelationGetRelationName(state->rel))));
 		else if (!VARATT_IS_COMPRESSED(DatumGetPointer(normalized[i])) &&
-				 VARSIZE(DatumGetPointer(normalized[i])) > TOAST_INDEX_TARGET &&
+				 VARSIZE_ANY(DatumGetPointer(normalized[i])) > TOAST_INDEX_TARGET &&
 				 (att->attstorage == TYPSTORAGE_EXTENDED ||
 				  att->attstorage == TYPSTORAGE_MAIN))
 		{