Bug #339 myisam_max_sort_file_size and myisam_max_extra_sort_file can't be set high

Description:
Values for myisam_sort_file_size and myisam_extra_sort_file size can't
be set to above 4G at server startup:

mysql> show variables like "myisam%";
+---------------------------------+------------+
| Variable_name                   | Value      |
+---------------------------------+------------+
| myisam_max_extra_sort_file_size | 4294967295 |
| myisam_max_sort_file_size       | 4293918720 |
| myisam_recover_options          | OFF        |
| myisam_sort_buffer_size         | 134217728  |
+---------------------------------+------------+
4 rows in set (0.00 sec)

This is from server started with myisam_max_sort_file_size=100G
myisam_max_sort_file_size=100G

On other hand you can set them higher with SET option:
mysql> set myisam_max_sort_file_size=100000000000;
Query OK, 0 rows affected (0.00 sec)

mysql> show variables like "myisam%";
+---------------------------------+--------------+
| Variable_name                   | Value        |
+---------------------------------+--------------+
| myisam_max_extra_sort_file_size | 4294967295   |
| myisam_max_sort_file_size       | 100000000000 |
| myisam_recover_options          | OFF          |
| myisam_sort_buffer_size         | 134217728    |
+---------------------------------+--------------+
4 rows in set (0.00 sec)

How to repeat:
start mysqld with myisam_max_sort_file_size more than 4G.

Thank you for your bug report. This issue has been fixed in the latest
development tree for that product. You can find more information about
accessing our development trees at 
    http://www.mysql.com/doc/en/Installing_source_tree.html