LP:665669 - Result differences on query re-execution

The following RQG command line

perl runall.pl -queries=1M --duration=300 --threads=1 --seed=time --reporter=Deadlock,Backtrace,ErrorLog --validator=Transformer --mysqld=optimizer_switch=join_cache_hashed=off --notnull --engine=InnoDB --mysqld=join_cache_level=6 --mysqld=-join_buffer_size=10K --grammar=conf/optimizer/outer_join.yy --gendata=conf/optimizer/outer_join.zz --queries=100000000 --basedir=/home/philips/bzr/maria-5.3 --seed=1287834481 --views --valgrind --duration=9000

reports a sporadic result difference in the following query:

1. 2010-10-23T22:14:20 Original query: SELECT SQL_SMALL_RESULT table1 . `col_int` AS field1 , table2 . `col_int` AS field2 , table1 . `col_int` AS field3 , table1 . `col_int` AS field4 , table2 . `pk` AS field5 , table1 . `pk` AS field6 FROM vV_0 AS table1 RIGHT JOIN EE AS table2 LEFT JOIN vZ_0 AS table3 ON table2 . `col_int_key` = table3 . `pk` ON table1 . `pk` = table3 . `pk` LEFT JOIN vR_0 AS table4 ON table3 . `pk` = table4 . `col_int` WHERE table4 . `pk` <> 3 HAVING field3 <> 8 ORDER BY field1 DESC , field1 DESC , field2 failed transformation with Transformer DisableChosenPlan

1. 2010-10-23T22:14:20 Transformed query: /* GenTest::Transform::DisableChosenPlan / SET @switch_saved = @@optimizer_switch;; SET SESSION optimizer_switch='join_cache_bka=off';; SELECT SQL_SMALL_RESULT table1 . `col_int` AS field1 , table2 . `col_int` AS field2 , table1 . `col_int` AS field3 , table1 . `col_int` AS field4 , table2 . `pk` AS field5 , table1 . `pk` AS field6 FROM vV_0 AS table1 RIGHT JOIN EE AS table2 LEFT JOIN vZ_0 AS table3 ON table2 . `col_int_key` = table3 . `pk` ON table1 . `pk` = table3 . `pk` LEFT JOIN vR_0 AS table4 ON table3 . `pk` = table4 . `col_int` WHERE table4 . `pk` <> 3 HAVING field3 <> 8 ORDER BY field1 DESC , field1 DESC , field2 / TRANSFORM_OUTCOME_UNORDERED_MATCH */ ;; SET SESSION optimizer_switch=@switch_saved

Unfortunately the failure does not repeat when the query is executed again or is run standalone as an MTR test case. Valgrind also does not report anything.