From 1c68f8f7bd50ab1ef0b8a08b5b6e8d80646259a6 Mon Sep 17 00:00:00 2001
From: passwdwasforgotten <809389860@qq.com>
Date: Mon, 15 Sep 2025 15:57:59 +0800
Subject: [PATCH] Fix: missing validation for tids when index's deduplicate is
 on

In the '_bt_validate_tid' method, the IndexTuple 'ituple' is not
deformed when processing the posting tuple, resulting in
missing validation for certain TIDs.
---
 src/backend/access/nbtree/nbtree.c | 32 +++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c
index 7c3563024db..5dc783846cb 100644
--- a/src/backend/access/nbtree/nbtree.c
+++ b/src/backend/access/nbtree/nbtree.c
@@ -223,7 +223,37 @@ _bt_validate_tid(Relation irel, ItemPointer h_tid)
 			{
 				itup = (IndexTuple) PageGetItem(page,
 												PageGetItemId(page, offnum));
-				if (ItemPointerEquals(&itup->t_tid, h_tid))
+				if(BTreeTupleIsPosting(itup))
+				{
+					ItemPointer current;
+					for (int i = 0; i < BTreeTupleGetNPosting(itup); i++)
+					{
+
+						current = BTreeTupleGetPostingN(itup, i);
+
+						if (ItemPointerEquals(current, h_tid) )
+						{
+							Form_pg_attribute key_att = TupleDescAttr(RelationGetDescr(irel), 0);
+							Oid key = InvalidOid;
+							bool isnull;
+							if (key_att->atttypid == OIDOID)
+							{
+								key = DatumGetInt32(
+										index_getattr(itup, 1, RelationGetDescr(irel), &isnull));
+								elog(ERROR, "found tid (%d,%d), %s (%d) already in index (%s)",
+									ItemPointerGetBlockNumber(h_tid), ItemPointerGetOffsetNumber(h_tid),
+									NameStr(key_att->attname), key, RelationGetRelationName(irel));
+							}
+							else
+							{
+								elog(ERROR, "found tid (%d,%d) already in index (%s)",
+									ItemPointerGetBlockNumber(h_tid), ItemPointerGetOffsetNumber(h_tid),
+									RelationGetRelationName(irel));
+							}
+						}
+					}
+				}
+				else if (ItemPointerEquals(&itup->t_tid, h_tid))
 				{
 					Form_pg_attribute key_att = TupleDescAttr(RelationGetDescr(irel), 0);
 					Oid key = InvalidOid;