CREATE TABLE t1 (a INT NOT NULL) ENGINE=InnoDB STATS_PERSISTENT=0;
connect ddl,localhost,root;
SET DEBUG_SYNC='after_trx_committed_in_memory SIGNAL stuck WAIT_FOR ever';
ALTER TABLE t1 ADD PRIMARY KEY(a);
connection default;
SET DEBUG_SYNC='now WAIT_FOR stuck';
SET GLOBAL innodb_log_checkpoint_now=ON;
# restart
disconnect ddl;
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` int(11) NOT NULL,
  PRIMARY KEY (`a`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci STATS_PERSISTENT=0
SELECT * FROM t1;
a
DROP TABLE t1;
InnoDB		0 transactions not purged