main.union fails sporadically in buildbot

main.union                               [ fail ]

        Test ended at 2014-11-23 07:36:46

CURRENT_TEST: main.union

--- C:/bzr/bb-win32/win64-release/build/mysql-test/r/union.result	2014-11-22 11:33:13.342289000 -0800

+++ C:\bzr\bb-win32\win64-release\build\mysql-test\r\union.reject	2014-11-23 07:36:45.650723800 -0800

@@ -1598,8 +1598,8 @@

 SELECT * FROM t1 UNION SELECT * FROM t1

 ORDER BY MATCH(a) AGAINST ('+abc' IN BOOLEAN MODE);

 a

-1

 2

+1

 # Should not crash

 (SELECT * FROM t1) UNION (SELECT * FROM t1)

 ORDER BY MATCH(a) AGAINST ('+abc' IN BOOLEAN MODE);

mysqltest: Result content mismatch