Users can't set a password using django-allauth

Users can't set a password using django-allauth

I'm using the latest Pypi django-allauth version and I have an issue when
setting a password for accounts created through a 3rd party provider e.g.
Facebook or Twitter.
When the user signs up everything works fine, but if he wants to set a
password to be also able to login with username & pass, then it seems that
the password has already been set because he's automatically redirected to
the change password page (and this only happens if the user already has an
usable pass).
So, my questions are: how is this "default password" calculated? Is this
an empty hashed string? How can I allow users actually set a password?
Now they can use the reset password option, but this may cause confusion
as the user hasn't already set it.