Fixed #28757 -- Allowed using contrib.auth forms without installing contrib.auth.

Also fixed #28608 -- Allowed UserCreationForm and UserChangeForm to
work with custom user models.

Thanks Sagar Chalise and Rômulo Collopy for reports, and Tim Graham
and Tim Martin for reviews.

docs/releases/2.1.txt

@@ -48,6 +48,10 @@ Minor features
 * :djadmin:`createsuperuser` now gives a prompt to allow bypassing the
   :setting:`AUTH_PASSWORD_VALIDATORS` checks.
 
+* :class:`~django.contrib.auth.forms.UserCreationForm` and
+  :class:`~django.contrib.auth.forms.UserChangeForm` no longer need to be
+  rewritten for a custom user model.
+
 :mod:`django.contrib.contenttypes`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

docs/topics/auth/customizing.txt

@@ -820,11 +820,20 @@ are working with.
 The following forms are compatible with any subclass of
 :class:`~django.contrib.auth.models.AbstractBaseUser`:
 
-* :class:`~django.contrib.auth.forms.AuthenticationForm`: Uses the username
-  field specified by :attr:`~models.CustomUser.USERNAME_FIELD`.
+* :class:`~django.contrib.auth.forms.AuthenticationForm`
 * :class:`~django.contrib.auth.forms.SetPasswordForm`
 * :class:`~django.contrib.auth.forms.PasswordChangeForm`
 * :class:`~django.contrib.auth.forms.AdminPasswordChangeForm`
+* :class:`~django.contrib.auth.forms.UserCreationForm`
+* :class:`~django.contrib.auth.forms.UserChangeForm`
+
+The forms that handle a username use the username field specified by
+:attr:`~models.CustomUser.USERNAME_FIELD`.
+
+.. versionchanged:: 2.1
+
+    In older versions, ``UserCreationForm`` and ``UserChangeForm`` need to be
+    rewritten to work with custom user models.
 
 The following forms make assumptions about the user model and can be used as-is
 if those assumptions are met:
@@ -835,25 +844,6 @@ if those assumptions are met:
   default) that can be used to identify the user and a boolean field named
   ``is_active`` to prevent password resets for inactive users.
 
-Finally, the following forms are tied to
-:class:`~django.contrib.auth.models.User` and need to be rewritten or extended
-to work with a custom user model:
-
-* :class:`~django.contrib.auth.forms.UserCreationForm`
-* :class:`~django.contrib.auth.forms.UserChangeForm`
-
-If your custom user model is a simple subclass of ``AbstractUser``, then you
-can extend these forms in this manner::
-
-    from django.contrib.auth.forms import UserCreationForm
-    from myapp.models import CustomUser
-
-    class CustomUserCreationForm(UserCreationForm):
-
-        class Meta(UserCreationForm.Meta):
-            model = CustomUser
-            fields = UserCreationForm.Meta.fields + ('custom_field',)
-
 Custom users and :mod:`django.contrib.admin`
 --------------------------------------------
 

docs/topics/auth/default.txt

@@ -1486,9 +1486,12 @@ provides several built-in forms located in :mod:`django.contrib.auth.forms`:
 
     A :class:`~django.forms.ModelForm` for creating a new user.
 
-    It has three fields: ``username`` (from the user model), ``password1``,
-    and ``password2``. It verifies that ``password1`` and ``password2`` match,
-    validates the password using
+    It has three fields: one named after the
+    :attr:`~django.contrib.auth.models.CustomUser.USERNAME_FIELD` from the
+    user model, and ``password1`` and ``password2``.
+
+    It verifies that ``password1`` and ``password2`` match, validates the
+    password using
     :func:`~django.contrib.auth.password_validation.validate_password`, and
     sets the user's password using
     :meth:`~django.contrib.auth.models.User.set_password()`.