Last modified: 2011-03-13 18:06:33 UTC
Besides of the fact that 32 chars is sometimes too low (see bug:2693), by checking for a byte size the maximum character count for usernames not using ASCII is reduced to one half or one third. (For example, usernames in cyrillic would have a maximum size of 16 chars.)
It's necessary to test the number of bytes rather than the number of characters since the database works with bytes ( user_name has a maximum of 255 bytes ) and not characters, closing as WONTFIX.