mroonga/storage.* tests fail on Fedora 28 with wrong result

mroonga/storage.index_multiple_column_range_partially_used_have_prefix_less_than w2 [ fail ]

        Test ended at 2018-05-22 23:23:31

CURRENT_TEST: mroonga/storage.index_multiple_column_range_partially_used_have_prefix_less_than

--- /usr/share/mysql-test/plugin/mroonga/mroonga/storage/r/index_multiple_column_range_partially_used_have_prefix_less_than.result	2018-05-22 20:29:32.000000000 +0000

+++ /dev/shm/var/2/log/index_multiple_column_range_partially_used_have_prefix_less_than.reject	2018-05-22 23:23:31.680620646 +0000

@@ -30,5 +30,4 @@

 WHERE score1 = 2 AND created_at < "2015-07-01 12:00:00"

        ORDER BY created_at DESC;

 id	score1	score2	created_at

-2	2	0	2015-07-01 00:00:00

 DROP TABLE items;

mysqltest: Result length mismatch

mroonga/storage.index_multiple_column_range_partially_used_have_prefix_less_than

mroonga/storage.index_multiple_column_range_all_used_less_than_or_equal

mroonga/storage.optimization_order_limit_optimized_datetime_less_than_or_equal

mroonga/storage.index_multiple_column_range_all_used_less_than

mroonga/storage.optimization_order_limit_optimized_datetime_less_than

mroonga/storage.index_multiple_column_range_partially_used_no_prefix_less_than_or_equal

mroonga/storage.index_multiple_column_range_partially_used_no_prefix_less_than

mroonga/storage.index_multiple_column_range_partially_used_have_prefix_less_than_or_equal