CREATE TABLE ... SELECT can result in column type "null"

[Kristian Nielsen]

CREATE TABLE t1 ENGINE = INNODB AS SELECT IF(NULL IS NOT NULL, NULL, NULL);
SHOW CREATE TABLE t1;

Create Table: CREATE TABLE `t1` (
  `IF(NULL IS NOT NULL, NULL, NULL)` null DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1

Note the column type "null". This is not valid in CREATE TABLE, so for example
a mysqldump including such a table will not be able to re-create the table.

This is MySQL bug#54394: http://bugs.mysql.com/bug.php?id=54394