Have UserChangeForm and UserCreationForm utilize get_user_model()

[ChocolateCookies]

While I was trying to re-use the creation form for the admin interface with my custom User model (derived from AbstractUser), I stumbled upon an issue, namely I couldn't re-use it. I might have thought of a solution, but it's probably not very elegant.

In contrib.auth.forms the model meta property for UserChangeForm is User, but in for example AuthenticationForm, the method get_user_model is utilized. Consequently I cannot use the form, because this class imports auth.User instead of my own User model. Is this on purpose, or would it be possible to extend AUTH_USER_MODEL to the creation and change forms?

I would say it is only possible if a custom User model is derived from AbstractUser, as opposed to AbstractBaseUser (​Like the Django docs suggest). AbstractUser guarantees the fields that these forms use (username, email), while AbstractBaseUser doesn't. Although that takes away a lot of the flexibility of specifying a custom User model, so maybe there's a middle ground somewhere.

contrib/auth/forms.py:

class UserChangeForm(forms.ModelForm):
...
    class Meta:
        model = User
...

[Baptiste Mispelon]

Correct me if I'm wrong, but I believe this is a duplicate of #19353.