MyISAM wrong server status flags

created after CONJ-948

Synchronous connectors can rely on OK_Packet/EOF_Packet server status's SERVER_STATUS_IN_TRANS flag that explicitly indicate if a transaction is currently active.

Java connector use that information to avoid issuing a rollback/commit command, skipping the command if there is no transaction.

Problem concerns only MyISAM that never set SERVER_STATUS_IN_TRANS flag. Still there is some case when there is some kind of lock : ( example from serg: )

create table t1 (a int)  engine=myisam;

insert t1 values (1);

and in another

drop table t1;

this DROP TABLE will wait until the transaction ends.

• either MyISAM should return SERVER_STATUS_IN_TRANS flag, so connector know there is really a commit to be issued.
• either MyISAM doesn't set any lock. (It may be just an issue : for some metadata locks are taken on the object name, before the table is opened, before we know it's a MyISAM table.)

Either way is ok.

(Another solution would be to always issue a COMMIT/ROLLBACK statement when there is no need, but that would degrade performance dramatically for some application. For example when connections are given back to pools, pools generally issues a connection.rollback() to ensure connection state, and there is lots of application where that command would represent 25% of the commands)