[issue-983] querying history, convert to instance, chase foreign key on history_date

Author: jeking3

simple_history/models.py

@@ -673,7 +673,7 @@ def get_queryset(self, **hints) -> QuerySet:
                 None,
             )
             if history and histmgr:
-                return histmgr.as_of(history._as_of)
+                return histmgr.as_of(getattr(history, "_as_of", history.history_date))
         return super().get_queryset(**hints)
 
 
@@ -708,7 +708,9 @@ def get_queryset(self):
                         None,
                     )
                     if history and histmgr:
-                        queryset = histmgr.as_of(history._as_of)
+                        queryset = histmgr.as_of(
+                            getattr(history, "_as_of", history.history_date)
+                        )
                     else:
                         queryset = super().get_queryset()
                     return self._apply_rel_filters(queryset)

simple_history/tests/tests/test_models.py

@@ -2012,3 +2012,16 @@ def test_historic_to_historic(self):
             to_historic(ot1), TestOrganizationWithHistory.history.model
         )
         self.assertIsNone(to_historic(org))
+
+        # test querying directly from the history table and converting
+        # to an instance, it should chase the foreign key properly
+        # in this case if _as_of is not present we use the history_date
+        # https://github.com/jazzband/django-simple-history/issues/983
+        pt1h = TestHistoricParticipanToHistoricOrganization.history.all()[0]
+        pt1i = pt1h.instance
+        self.assertEqual(pt1i.organization.name, "modified")
+        pt1h = TestHistoricParticipanToHistoricOrganization.history.all().order_by(
+            "history_date"
+        )[0]
+        pt1i = pt1h.instance
+        self.assertEqual(pt1i.organization.name, "original")