Fixed #12644 - Allow overriding the admin user creation form based on r12216. Thanks, minmax.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12265 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/auth/admin.py

@@ -62,11 +62,11 @@ class UserAdmin(admin.ModelAdmin):
         Use special form during user creation
         """
         defaults = {}
-        if not obj:
-            defaults = {
-                'form': UserCreationForm,
-                'fields': ['username'],
-            }
+        if obj is None:
+            defaults.update({
+                'form': self.add_form,
+                'fields': admin.util.flatten_fieldsets(self.add_fieldsets),
+            })
         defaults.update(kwargs)
         return super(UserAdmin, self).get_form(request, obj, **defaults)