From 7a21ea5464b61a8fcd43cd1b9b5f99c94687600a Mon Sep 17 00:00:00 2001
From: nessita <124304+nessita@users.noreply.github.com>
Date: Mon, 13 Nov 2023 05:35:57 -0300
Subject: [PATCH] [5.0.x] Fixed #34958 -- Fixed isolation of
 messages_tests.tests.TestLevelTags.test_lazy.

Backport of 1b56b24f81a2e64b4bd3059abad9b6fd0c801c66 from main
---
 tests/messages_tests/tests.py | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/tests/messages_tests/tests.py b/tests/messages_tests/tests.py
index 17eb8639e8..19aeee9a08 100644
--- a/tests/messages_tests/tests.py
+++ b/tests/messages_tests/tests.py
@@ -1,3 +1,5 @@
+import importlib
+import sys
 from unittest import mock
 
 from django.conf import settings
@@ -65,8 +67,13 @@ class TestLevelTags(SimpleTestCase):
         self.assertEqual(base.LEVEL_TAGS, self.message_tags)
 
     def test_lazy(self):
+        storage_base_import_path = "django.contrib.messages.storage.base"
+        in_use_base = sys.modules.pop(storage_base_import_path)
+        self.addCleanup(sys.modules.__setitem__, storage_base_import_path, in_use_base)
         # Don't use @override_settings to avoid calling the setting_changed
-        # signal.
+        # signal, but ensure that base.LEVEL_TAGS hasn't been read yet (this
+        # means that we need to ensure the `base` module is freshly imported).
+        base = importlib.import_module(storage_base_import_path)
         old_message_tags = getattr(settings, "MESSAGE_TAGS", None)
         settings.MESSAGE_TAGS = {constants.ERROR: "bad"}
         try: