Fixed #24147 -- Prevented managers leaking model during migrations

Thanks Tim Graham for the review.

1 files changed, 38 insertions, 0 deletions

diff --git a/tests/migrations/test_state.py b/tests/migrations/test_state.py
index e069649810..6410477b36 100644
--- a/tests/migrations/test_state.py
+++ b/tests/migrations/test_state.py
@@ -1,5 +1,6 @@
 from django.apps.registry import Apps
 from django.db import models
+from django.db.migrations.operations import RemoveField
 from django.db.migrations.state import ProjectState, ModelState, InvalidBasesError
 from django.test import TestCase
 
@@ -505,6 +506,43 @@ class StateTests(TestCase):
             ["id", "author"],
         )
 
+    def test_manager_refer_correct_model_version(self):
+        """
+        #24147 - Tests that managers refer to the correct version of a
+        historical model
+        """
+        project_state = ProjectState()
+        project_state.add_model(ModelState(
+            app_label="migrations",
+            name="Tag",
+            fields=[
+                ("id", models.AutoField(primary_key=True)),
+                ("hidden", models.BooleanField()),
+            ],
+            managers=[
+                ('food_mgr', FoodManager('a', 'b')),
+                ('food_qs', FoodQuerySet.as_manager()),
+            ]
+        ))
+
+        old_model = project_state.apps.get_model('migrations', 'tag')
+
+        new_state = project_state.clone()
+        operation = RemoveField("tag", "hidden")
+        operation.state_forwards("migrations", new_state)
+
+        new_model = new_state.apps.get_model('migrations', 'tag')
+
+        self.assertIsNot(old_model, new_model)
+        self.assertIs(old_model, old_model.food_mgr.model)
+        self.assertIs(old_model, old_model.food_qs.model)
+        self.assertIs(new_model, new_model.food_mgr.model)
+        self.assertIs(new_model, new_model.food_qs.model)
+        self.assertIsNot(old_model.food_mgr, new_model.food_mgr)
+        self.assertIsNot(old_model.food_qs, new_model.food_qs)
+        self.assertIsNot(old_model.food_mgr.model, new_model.food_mgr.model)
+        self.assertIsNot(old_model.food_qs.model, new_model.food_qs.model)
+
 
 class ModelStateTests(TestCase):
     def test_custom_model_base(self):