1 files changed, 60 insertions, 3 deletions

diff --git a/src/backend/access/nbtree/nbtsearch.c b/src/backend/access/nbtree/nbtsearch.c
index 51dca64e139..4c6fdcdd8aa 100644
--- a/src/backend/access/nbtree/nbtsearch.c
+++ b/src/backend/access/nbtree/nbtsearch.c
@@ -147,7 +147,7 @@ _bt_search(Relation rel, int keysz, ScanKey scankey, bool nextkey,
 		offnum = _bt_binsrch(rel, *bufP, keysz, scankey, nextkey);
 		itemid = PageGetItemId(page, offnum);
 		itup = (IndexTuple) PageGetItem(page, itemid);
-		blkno = ItemPointerGetBlockNumber(&(itup->t_tid));
+		blkno = BTreeInnerTupleGetDownLink(itup);
 		par_blkno = BufferGetBlockNumber(*bufP);
 
 		/*
@@ -163,7 +163,7 @@ _bt_search(Relation rel, int keysz, ScanKey scankey, bool nextkey,
 		new_stack = (BTStack) palloc(sizeof(BTStackData));
 		new_stack->bts_blkno = par_blkno;
 		new_stack->bts_offset = offnum;
-		memcpy(&new_stack->bts_btentry, itup, sizeof(IndexTupleData));
+		new_stack->bts_btentry = blkno;
 		new_stack->bts_parent = stack_in;
 
 		/* drop the read lock on the parent page, acquire one on the child */
@@ -437,6 +437,15 @@ _bt_compare(Relation rel,
 	int			i;
 
 	/*
+	 * Check tuple has correct number of attributes.
+	 */
+	if (unlikely(!_bt_check_natts(rel, page, offnum)))
+		ereport(ERROR,
+				(errcode(ERRCODE_INTERNAL_ERROR),
+				 errmsg("tuple has wrong number of attributes in index \"%s\"",
+						RelationGetRelationName(rel))));
+
+	/*
 	 * Force result ">" if target item is first data item on an internal page
 	 * --- see NOTE above.
 	 */
@@ -1833,7 +1842,7 @@ _bt_get_endpoint(Relation rel, uint32 level, bool rightmost,
 			offnum = P_FIRSTDATAKEY(opaque);
 
 		itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, offnum));
-		blkno = ItemPointerGetBlockNumber(&(itup->t_tid));
+		blkno = BTreeInnerTupleGetDownLink(itup);
 
 		buf = _bt_relandgetbuf(rel, buf, blkno, BT_READ);
 		page = BufferGetPage(buf);
@@ -1959,3 +1968,51 @@ _bt_initialize_more_data(BTScanOpaque so, ScanDirection dir)
 	so->numKilled = 0;			/* just paranoia */
 	so->markItemIndex = -1;		/* ditto */
 }
+
+/*
+ * Check if index tuple have appropriate number of attributes.
+ */
+bool
+_bt_check_natts(Relation index, Page page, OffsetNumber offnum)
+{
+	int16		natts = IndexRelationGetNumberOfAttributes(index);
+	int16		nkeyatts = IndexRelationGetNumberOfKeyAttributes(index);
+	ItemId		itemid;
+	IndexTuple	itup;
+	BTPageOpaque opaque = (BTPageOpaque) PageGetSpecialPointer(page);
+
+	/*
+	 * Assert that mask allocated for number of keys in index tuple can fit
+	 * maximum number of index keys.
+	 */
+	StaticAssertStmt(BT_N_KEYS_OFFSET_MASK >= INDEX_MAX_KEYS,
+					 "BT_N_KEYS_OFFSET_MASK can't fit INDEX_MAX_KEYS");
+
+	itemid = PageGetItemId(page, offnum);
+	itup = (IndexTuple) PageGetItem(page, itemid);
+
+	if (P_ISLEAF(opaque) && offnum >= P_FIRSTDATAKEY(opaque))
+	{
+		/*
+		 * Regular leaf tuples have as every index attributes
+		 */
+		return (BTreeTupGetNAtts(itup, index) == natts);
+	}
+	else if (!P_ISLEAF(opaque) && offnum == P_FIRSTDATAKEY(opaque))
+	{
+		/*
+		 * Leftmost tuples on non-leaf pages have no attributes, or haven't
+		 * INDEX_ALT_TID_MASK set in pg_upgraded indexes.
+		 */
+		return (BTreeTupGetNAtts(itup, index) == 0 ||
+				((itup->t_info & INDEX_ALT_TID_MASK) == 0));
+	}
+	else
+	{
+		/*
+		 * Pivot tuples stored in non-leaf pages and hikeys of leaf pages
+		 * contain only key attributes
+		 */
+		return (BTreeTupGetNAtts(itup, index) == nkeyatts);
+	}
+}