LP:671340 - Diverging results in with mrr_sort_keys=ON|OFF and join_cache_level=5

The following query

SELECT table2.pk , table1.col_int_key
FROM t2 AS table1 JOIN
( t1 AS table2 JOIN t2 AS table3 ON table3.col_varchar_nokey = table2.col_varchar_key )
ON table3.pk > table2.col_varchar_nokey
ORDER BY table1.pk ;

returns less rows with mrr_sort_keys=OFF in maria-5.3-mwl128-dsmrr-cpk and different rows in maria-5.3-dsmrr-cpk . engine_condition_pushdown can be OFF, so it is not a duplicate of bug #670417