MyRocks: parallel slave on a table without PK can stop with ER_KEY_NOT_FOUND

# Run with --mysqld=--plugin-load-add=ha_rocksdb --mysqld=--slave-parallel-threads=2 --repeat=20

--source include/have_binlog_format_row.inc

--source include/master-slave.inc

CREATE TABLE t1 (a INT) ENGINE=RocksDB;

INSERT INTO t1 VALUES (1),(2),(3),(4);

CREATE TABLE t2 (a INT) ENGINE=RocksDB SELECT * FROM t1;

INSERT INTO t2 VALUES (5),(6),(7),(8);

DELETE FROM t2;

--sync_slave_with_master

# Cleanup

--connection master

DROP TABLE t1, t2;

--source include/rpl_end.inc

2018-05-22 14:56:42 139894937147136 [ERROR] mysqld: Can't find record in 't2'

2018-05-22 14:56:42 139894937147136 [ERROR] Slave SQL: Could not execute Delete_rows_v1 event on table test.t2; Can't find record in 't2', Error_code: 1032; handler error HA_ERR_END_OF_FILE; the event's master log master-bin.000001, end_log_pos 1514, Gtid 0-1-5, Internal MariaDB error code: 1032

2018-05-22 14:56:42 139894937147136 [Warning] Slave: Can't find record in 't2' Error_code: 1032

2018-05-22 14:56:42 139894937147136 [ERROR] Error running query, slave SQL thread aborted. Fix the problem, and restart the slave SQL thread with "SLAVE START". We stopped at log 'master-bin.000001' position 1317