HeapTupleHeaderAdjustCmax made the incorrect assumption that the raw

command id is the cmin, when it can in fact be a combo cid. That made rows
incorrectly invisible to a transaction where a tuple was deleted by multiple
aborted subtransactions.

Report and patch Karl Schnaitter. Back-patch to 8.3, where combo cids was
introduced.

src/backend/utils/time/combocid.c

@@ -34,7 +34,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/time/combocid.c,v 1.4 2008/01/01 19:45:55 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/time/combocid.c,v 1.5 2008/09/01 18:52:45 heikki Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -155,7 +155,7 @@ HeapTupleHeaderAdjustCmax(HeapTupleHeader tup,
 	if (!(tup->t_infomask & HEAP_XMIN_COMMITTED) &&
 		TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(tup)))
 	{
-		CommandId	cmin = HeapTupleHeaderGetRawCommandId(tup);
+		CommandId	cmin = HeapTupleHeaderGetCmin(tup);
 
 		*cmax = GetComboCommandId(cmin, *cmax);
 		*iscombo = true;