Change admin.py to use Django's registered User Model (#1177)

* Update admin.py to use django's get_user_model

Change the admin to properly integrate with custom user models

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* Updated CHANGES.rst for #1177

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Anders <[email protected]>

Author: 3 people

CHANGES.rst

@@ -8,6 +8,7 @@ Unreleased
 - Added feature to evaluate ``history`` model permissions explicitly when
   ``SIMPLE_HISTORY_ENFORCE_HISTORY_MODEL_PERMISSIONS`` is set to ``True``
   in ``settings`` (gh-1017).
+- Fixed ``SimpleHistoryAdmin`` not properly integrating with custom user models (gh-1177)
 
 3.3.0 (2023-03-08)
 ------------------

simple_history/admin.py

@@ -4,7 +4,7 @@
 from django.contrib import admin
 from django.contrib.admin import helpers
 from django.contrib.admin.utils import unquote
-from django.contrib.auth import get_permission_codename
+from django.contrib.auth import get_permission_codename, get_user_model
 from django.core.exceptions import PermissionDenied
 from django.shortcuts import get_object_or_404, render
 from django.urls import re_path, reverse
@@ -15,8 +15,6 @@
 
 from .utils import get_history_manager_for_model, get_history_model_for_model
 
-USER_NATURAL_KEY = tuple(key.lower() for key in settings.AUTH_USER_MODEL.split(".", 1))
-
 SIMPLE_HISTORY_EDIT = getattr(settings, "SIMPLE_HISTORY_EDIT", False)
 
 
@@ -72,9 +70,10 @@ def history_view(self, request, object_id, extra_context=None):
                 for list_entry in action_list:
                     setattr(list_entry, history_list_entry, value_for_entry(list_entry))
 
-        content_type = self.content_type_model_cls.objects.get_by_natural_key(
-            *USER_NATURAL_KEY
+        content_type = self.content_type_model_cls.objects.get_for_model(
+            get_user_model()
         )
+
         admin_user_view = "admin:{}_{}_change".format(
             content_type.app_label,
             content_type.model,