Replication fails on updating a MEMORY table with an index using btree

--source include/master-slave.inc

--source include/have_binlog_format_row.inc

CREATE TABLE t1 (f1 VARCHAR(128), f2 VARCHAR(128), KEY (f2,f1) USING BTREE) ENGINE=MEMORY;

INSERT INTO t1 VALUES (NULL,'not'),('one',NULL),('two',NULL),('three','');

UPDATE t1 SET f2 = 'new';

--sync_slave_with_master

Last_Error	Could not execute Update_rows event on table test.t1; Can't find record in 't1', Error_code: 1032; handler error HA_ERR_KEY_NOT_FOUND; the event's master log master-bin.000001, end_log_pos 694