When create a new account on wmf wikis you will automatically redirect to the returnto page.
A success message (welcomecreation-msg) must be shown, so new users will see, that the account is created successfully has worked.
Silent login is okay, but silent signup/account creation is bad.
Fill this in CentralAuth, because it works on my test wiki. But it can also be a config thing.
Version: unspecified
Severity: normal
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=52834