Incorrect enum values returned when using union after "create as select"

MariaDB [(none)]> create database d1;

Query OK, 1 row affected (0.00 sec)

MariaDB [(none)]> use d1;

Database changed

MariaDB [d1]> create table t1 (e enum('one', 'two'));

Query OK, 0 rows affected (0.75 sec)

MariaDB [d1]> insert into t1 values ('one');

Query OK, 1 row affected (0.40 sec)

MariaDB [d1]> create table t2 (e enum('one', 'two')) as select * from t1;

Query OK, 1 row affected (0.78 sec)

Records: 1  Duplicates: 0  Warnings: 0

MariaDB [d1]> select * from t2;

+------+

| e    |

+------+

| one  |

+------+

1 row in set (0.01 sec)

MariaDB [d1]> select * from t2 union all select * from t2;

+------+

| e    |

+------+

| o    |

| o    |

+------+

2 rows in set (0.00 sec)

MariaDB [d1]> alter table t2 engine MyISAM;

Query OK, 1 row affected (0.91 sec)                

Records: 1  Duplicates: 0  Warnings: 0

MariaDB [d1]> select * from t2 union all select * from t2;

+------+

| e    |

+------+

| one  |

| one  |

+------+

2 rows in set (0.00 sec)

MariaDB [d1]> 

--- a/sql/sql_table.cc

+++ b/sql/sql_table.cc

@@ -3144,7 +3144,7 @@ mysql_prepare_create_table(THD *thd, HA_CREATE_INFO *create_info,

          sql_field->charset=           (dup_field->charset ?

                                         dup_field->charset :

                                         create_info->default_table_charset);

-         sql_field->length=            dup_field->char_length;

+         sql_field->length=            dup_field->length;

           sql_field->pack_length=      dup_field->pack_length;

           sql_field->key_length=       dup_field->key_length;

          sql_field->decimals=          dup_field->decimals;