set global innodb_file_per_table=on;
set global innodb_file_format='Barracuda';
CREATE TABLE t1(c1 INT NOT NULL, c2 INT, PRIMARY KEY(c1)) Engine=InnoDB;
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `c1` int(11) NOT NULL,
  `c2` int(11) DEFAULT NULL,
  PRIMARY KEY (`c1`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1
INSERT INTO t1 VALUES (1,1),(2,2),(3,3),(4,4),(5,5);
SET SESSION DEBUG='+d,ib_build_indexes_too_many_concurrent_trxs, ib_rename_indexes_too_many_concurrent_trxs, ib_drop_index_too_many_concurrent_trxs';
ALTER TABLE t1 ADD UNIQUE INDEX(c2);
ERROR HY000: Too many active concurrent transactions
SET SESSION DEBUG=DEFAULT;
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `c1` int(11) NOT NULL,
  `c2` int(11) DEFAULT NULL,
  PRIMARY KEY (`c1`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1
DROP TABLE t1;
CREATE TABLE bug13861218 (c1 INT NOT NULL, c2 INT NOT NULL, INDEX(c2))
ENGINE=InnoDB;
INSERT INTO bug13861218 VALUES (8, 0), (4, 0), (0, 0);
SET DEBUG='+d,ib_row_merge_buf_add_two';
CREATE UNIQUE INDEX ui ON bug13861218(c1);
SET DEBUG='-d,ib_row_merge_buf_add_two';
DROP TABLE bug13861218;
CREATE TABLE bug13861218 (c1 INT NOT NULL, c2 INT UNIQUE) ENGINE=InnoDB;
INSERT INTO bug13861218 VALUES (8, NULL), (4, NULL), (0, NULL);
SET DEBUG='+d,ib_row_merge_buf_add_two';
CREATE UNIQUE INDEX ui ON bug13861218(c1);
SET DEBUG='-d,ib_row_merge_buf_add_two';
DROP TABLE bug13861218;
set global innodb_file_per_table=1;
set global innodb_file_format=Antelope;
set global innodb_file_format_max=Antelope;