http://bugs.mysql.com/bug.php?id=68759

DROP TABLE IF EXISTS t_inno;
CREATE TABLE t_inno (pk INT PRIMARY KEY, t_key TIME, t TIME, KEY(t_key)) ENGINE=InnoDB;
INSERT INTO t_inno VALUES (1,'12:12:12','12:12:12'),(2,'21:21:21','21:21:21');

SELECT * FROM t_inno WHERE t < 'z';
SELECT pk FROM t_inno WHERE t_key < 'z';
SELECT * FROM t_inno WHERE t_key < 'z';

MySQL [test]> DROP TABLE IF EXISTS t_inno;
Query OK, 0 rows affected (0.20 sec)

MySQL [test]> CREATE TABLE t_inno (pk INT PRIMARY KEY, t_key TIME, t TIME, KEY(t_key)) ENGINE=InnoDB;
Query OK, 0 rows affected (1.20 sec)

MySQL [test]> INSERT INTO t_inno VALUES (1,'12:12:12','12:12:12'),(2,'21:21:21','21:21:21');
Query OK, 2 rows affected (0.07 sec)
Records: 2 Duplicates: 0 Warnings: 0

MySQL [test]>
MySQL [test]> SELECT * FROM t_inno WHERE t < 'z';
--------------------

--------------------

--------------------
2 rows in set, 1 warning (0.00 sec)

MySQL [test]> SELECT pk FROM t_inno WHERE t_key < 'z';
----

----

----
2 rows in set, 2 warnings (0.00 sec)

MySQL [test]> SELECT * FROM t_inno WHERE t_key < 'z';
Empty set, 2 warnings (0.00 sec)

Possibly file later

MySQL [test]> select @@sql_mode;
------------------------

------------------------

------------------------
1 row in set (0.00 sec)

MySQL [test]> show create table t2;
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

MySQL [test]> select * from t2;
--------------------

--------------------

--------------------
2 rows in set (0.00 sec)

MySQL [test]> update t2 set i = u-1;
ERROR 1690 (22003): BIGINT UNSIGNED value is out of range in '(`test`.`t2`.`u` - 1)'
MySQL [test]>

Filed bug http://bugs.mysql.com/bug.php?id=69203 (Valgrind warnings and crash on select from an InnoDB table), for 5.7 revno 5216.
Test case:
CREATE TABLE t1 (pk INT PRIMARY KEY) ENGINE=InnoDB;
INSERT INTO t1 VALUES (10),(11);

SELECT * FROM t1;

1. End of test case

When run with --valgrind-mysqld under MTR, causes a valgrind warnings and a crash on BUILD/compile-pentium-debug-max-no-ndb

MySQL (and MariaDB) prints garbage in warning records:

2013-08-09 23:46:52 7f4dafeec740 InnoDB: Warning: Using innodb_additional_mem_pool_size is DEPRECATED. This option may be removed in future releases, together with the option innodb_use_sys_malloc and with the InnoDB's internal memory allocator.
2013-08-09 23:46:52 7f4dafeec740 InnoDB: Warning: Using innodb_locks_unsafe_for_binlog is DEPRECATED. This option may be removed in future releases. Please use READ COMMITTED transaction isolation level instead, see http://dev.mysql.com/doc/refman/10.0/en/set-transaction.html.

I think there was an upstream bug about it, but can't find it now, need to check later.

https://github.com/MySQLOnRocksDB/mysql-5.6/issues/70