You can commit the changes to SVN if you like.
There is one requirement though, the login field must be invisible by default so that it is not shown in the interface if this function is not explicitley activated in the server settings on the email tab. Otherwise it might confuse the existing users.
Is that correct or do I have to change it to "SELECT login AS user" ?
I guess it has to be "SELECT login AS user", but I'am not 100% sure too.