`lock table read`, then select on unlocked table, transaction will be rollback

[actiontech-bot]

Raised by: @FlyingMao Steps:

1. lock table sbtest1 read;
2. select * from sbtest2;
3. select * from sbtest2;
4. unlock tables;
5. select * from sbtest2; Returns: Error 1105（HY000）：MySQL Error Packet{Length=56,id=1}

Analysis: Data-node general log shows there is a rollback after first select.