diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index 4020906..2dca6a9 100644
*** a/src/backend/access/heap/heapam.c
--- b/src/backend/access/heap/heapam.c
*************** simple_heap_insert(Relation relation, He
*** 2041,2050 ****
   * HeapTupleSelfUpdated, HeapTupleUpdated, or HeapTupleBeingUpdated
   * (the last only possible if wait == false).
   *
!  * In the failure cases, the routine returns the tuple's t_ctid and t_xmax.
!  * If t_ctid is the same as tid, the tuple was deleted; if different, the
!  * tuple was updated, and t_ctid is the location of the replacement tuple.
!  * (t_xmax is needed to verify that the replacement tuple matches.)
   */
  HTSU_Result
  heap_delete(Relation relation, ItemPointer tid,
--- 2041,2055 ----
   * HeapTupleSelfUpdated, HeapTupleUpdated, or HeapTupleBeingUpdated
   * (the last only possible if wait == false).
   *
!  * In case of a failure, the reason can be determined from the tuple's
!  * t_ctid and t_xmax values returned in ctid and update_xmax.
!  * If ctid is the same as otid and update_xmax is InvalidTransactionId the
!  * tupe was neither updated nor deleted, but is invisible to the crosscheck
!  * snapshot. If ctid equals otid and update_xmax is a valid transactionid,
!  * the tuple was deleted by the transaction in update_xmax.
!  * Otherwise, if ctid differes from otid, the tuple was updated and ctid is
!  * the location of the replacement tuple; update_xmax should in this case be
!  * used to verify that the replacement tuple matches.
   */
  HTSU_Result
  heap_delete(Relation relation, ItemPointer tid,
*************** l1:
*** 2175,2191 ****
  	{
  		/* Perform additional check for transaction-snapshot mode RI updates */
  		if (!HeapTupleSatisfiesVisibility(&tp, crosscheck, buffer))
  			result = HeapTupleUpdated;
  	}
  
  	if (result != HeapTupleMayBeUpdated)
  	{
  		Assert(result == HeapTupleSelfUpdated ||
  			   result == HeapTupleUpdated ||
  			   result == HeapTupleBeingUpdated);
- 		Assert(!(tp.t_data->t_infomask & HEAP_XMAX_INVALID));
  		*ctid = tp.t_data->t_ctid;
- 		*update_xmax = HeapTupleHeaderGetXmax(tp.t_data);
  		UnlockReleaseBuffer(buffer);
  		if (have_tuple_lock)
  			UnlockTuple(relation, &(tp.t_self), ExclusiveLock);
--- 2180,2203 ----
  	{
  		/* Perform additional check for transaction-snapshot mode RI updates */
  		if (!HeapTupleSatisfiesVisibility(&tp, crosscheck, buffer))
+ 		{
  			result = HeapTupleUpdated;
+ 			*update_xmax = InvalidTransactionId;
+ 		}
+ 	}
+ 	else if (result != HeapTupleMayBeUpdated)
+ 	{
+ 		Assert(!(tp.t_data->t_infomask & HEAP_XMAX_INVALID));
+ 		*update_xmax = HeapTupleHeaderGetXmax(tp.t_data);
  	}
+ 		
  
  	if (result != HeapTupleMayBeUpdated)
  	{
  		Assert(result == HeapTupleSelfUpdated ||
  			   result == HeapTupleUpdated ||
  			   result == HeapTupleBeingUpdated);
  		*ctid = tp.t_data->t_ctid;
  		UnlockReleaseBuffer(buffer);
  		if (have_tuple_lock)
  			UnlockTuple(relation, &(tp.t_self), ExclusiveLock);
*************** simple_heap_delete(Relation relation, It
*** 2363,2372 ****
   * update was done.  However, any TOAST changes in the new tuple's
   * data are not reflected into *newtup.
   *
!  * In the failure cases, the routine returns the tuple's t_ctid and t_xmax.
!  * If t_ctid is the same as otid, the tuple was deleted; if different, the
!  * tuple was updated, and t_ctid is the location of the replacement tuple.
!  * (t_xmax is needed to verify that the replacement tuple matches.)
   */
  HTSU_Result
  heap_update(Relation relation, ItemPointer otid, HeapTuple newtup,
--- 2375,2389 ----
   * update was done.  However, any TOAST changes in the new tuple's
   * data are not reflected into *newtup.
   *
!  * In case of a failure, the reason can be determined from the tuple's
!  * t_ctid and t_xmax values returned in ctid and update_xmax.
!  * If ctid is the same as otid and update_xmax is InvalidTransactionId the
!  * tupe was neither updated nor deleted, but is invisible to the crosscheck
!  * snapshot. If ctid equals otid and update_xmax is a valid transactionid,
!  * the tuple was deleted by the transaction in update_xmax.
!  * Otherwise, if ctid differes from otid, the tuple was updated and ctid is
!  * the location of the replacement tuple; update_xmax should in this case be
!  * used to verify that the replacement tuple matches.
   */
  HTSU_Result
  heap_update(Relation relation, ItemPointer otid, HeapTuple newtup,
*************** l2:
*** 2527,2533 ****
--- 2544,2558 ----
  	{
  		/* Perform additional check for transaction-snapshot mode RI updates */
  		if (!HeapTupleSatisfiesVisibility(&oldtup, crosscheck, buffer))
+ 		{
  			result = HeapTupleUpdated;
+ 			*update_xmax = InvalidTransactionId;
+ 		}
+ 	}
+ 	else if (result != HeapTupleMayBeUpdated)
+ 	{
+ 		Assert(!(oldtup.t_data->t_infomask & HEAP_XMAX_INVALID));
+ 		*update_xmax = HeapTupleHeaderGetXmax(oldtup.t_data);
  	}
  
  	if (result != HeapTupleMayBeUpdated)
*************** l2:
*** 2535,2543 ****
  		Assert(result == HeapTupleSelfUpdated ||
  			   result == HeapTupleUpdated ||
  			   result == HeapTupleBeingUpdated);
- 		Assert(!(oldtup.t_data->t_infomask & HEAP_XMAX_INVALID));
  		*ctid = oldtup.t_data->t_ctid;
- 		*update_xmax = HeapTupleHeaderGetXmax(oldtup.t_data);
  		UnlockReleaseBuffer(buffer);
  		if (have_tuple_lock)
  			UnlockTuple(relation, &(oldtup.t_self), ExclusiveLock);
--- 2560,2566 ----