UPDATE always returns "0 rows affected"

Build tested: 1.4.0-1

engine commit:
1f47534

MariaDB [mytest]> select * from t2;
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1 row in set (0.012 sec)

MariaDB [mytest]> update t2 set c1=6;
Query OK, 0 rows affected (0.325 sec)
Rows matched: 0 Changed: 0 Warnings: 0

MariaDB [mytest]> select * from t2;
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------

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1 row in set (0.009 sec)

MariaDB [mytest]> select count from orders;
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count

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1 row in set (0.097 sec)

MariaDB [mytest]> update orders set o_orderkey = 1;
Query OK, 0 rows affected (2.565 sec)
Rows matched: 0 Changed: 0 Warnings: 0

MariaDB [mytest]> select count from orders where o_orderkey = 1;
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count

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1 row in set (0.127 sec)