From [#1919] conversation:
I can't change "Display Name" on my https://sourceforge.net/auth/prefs/ prefrences page. After changing the "Display Name" field I see Error Display Name cannot be empty. I neither can change "Email format" combo value. Same error. Is this related?
With the SF integration (e.g. auth.method != local) the display name field should be hidden (and not required on form validation). Not sure what the problem with Email format might be.
To test, log in and go to your auth/prefs page. Make sure the display name field does not display and you can save your email format preference successfully.
Looks good, merged to dev.