Refs #30324 -- Forced utf-8 encoding when loading templates for the technical 404 debug and congrats page.

django/views/debug.py

@@ -497,7 +497,7 @@ def technical_404_response(request, exception):
             module = obj.__module__
             caller = '%s.%s' % (module, caller)
 
-    with Path(CURRENT_DIR, 'templates', 'technical_404.html').open() as fh:
+    with Path(CURRENT_DIR, 'templates', 'technical_404.html').open(encoding='utf-8') as fh:
         t = DEBUG_ENGINE.from_string(fh.read())
     c = Context({
         'urlconf': urlconf,
@@ -514,7 +514,7 @@ def technical_404_response(request, exception):
 
 def default_urlconf(request):
     """Create an empty URLconf 404 error response."""
-    with Path(CURRENT_DIR, 'templates', 'default_urlconf.html').open() as fh:
+    with Path(CURRENT_DIR, 'templates', 'default_urlconf.html').open(encoding='utf-8') as fh:
         t = DEBUG_ENGINE.from_string(fh.read())
     c = Context({
         'version': get_docs_version(),

tests/view_tests/tests/test_debug.py

@@ -224,6 +224,19 @@ class DebugViewTests(SimpleTestCase):
             status_code=404
         )
 
+    def test_template_encoding(self):
+        """
+        The templates are loaded directly, not via a template loader, and
+        should be opened as utf-8 charset as is the default specified on
+        template engines.
+        """
+        with mock.patch.object(DebugPath, 'open') as m:
+            default_urlconf(None)
+            m.assert_called_once_with(encoding='utf-8')
+            m.reset_mock()
+            technical_404_response(mock.MagicMock(), mock.Mock())
+            m.assert_called_once_with(encoding='utf-8')
+
 
 class DebugViewQueriesAllowedTests(SimpleTestCase):
     # May need a query to initialize MySQL connection