Admin Log-in, When using "Use email as username" the username related settings shouldn't be applied

• Bug
• Conflict of two features (each works well independently)
• Developer Training
• Easy for Newbie Dev

At tiki-admin.php?page=login , Username, when I enable "Use email as username" some username settings are now hidden (meaning not in use) but they are still applied.

Minimum length
Maximum length
(And may be "Force lowercase")

I created an instance to test and reproduce.
You need to "really" register a user, not using the admin user to create new users.

How to reproduce :

1. Go to Admin, Control Panels and switch to "Advanced" (to see advanced preferences)
2. Go to log-in : tiki-admin.php?page=login, Registration & Log in
3. Enable : Users can register
4. Disable : Validate new user registrations by email (we don't want to validate email)
5. Go to : Username and set "Maximum length" to 6
6. Apply (save)
7. Use a different browser (check you are not logged), go to the Tiki and register a new user
8. Try to input more than 6 characters for the username, you will see this error:
   
9. Go back to your previous browser (logged as admin), log-in : tiki-admin.php?page=login, Username
10. Enable "Use email as username" option
    The parameters Minimum length, Maximum length, (And may be "Force lowercase") will be hidden has not relevant anymore.
11. Go back to your different browser (check you are not logged)
12. Create a new user with an email for login (obviously longer than 6 characters).
    You won't see an error on focus
13. Submit your registration and you will see the error:
    

In general, when a parent is disabled, children options and parameters should be kept but not applied.
This is critical when children parameters are hidden (accordion).

In this case, if I disabled "Use email as username", the parameters Minimum length, Maximum length
(And may be "Force lowercase") should not be applied (but kept).

This bug has been demonstrated on show2.tiki.org

Please demonstrate your bug on show2.tiki.org

This bug has been demonstrated on show.tikiwiki.org

Please demonstrate your bug on show.tikiwiki.org