[1.11.x] Fixed #27887 -- Fixed URLs check crash with namespaced URLs inside non-namespaced URLs.

Backport of b23d264046db1c8f58a174b9be27ee760341ba06 from master

1 files changed, 4 insertions, 1 deletions

diff --git a/django/core/checks/urls.py b/django/core/checks/urls.py
index ca21c62409..e1049167fd 100644
--- a/django/core/checks/urls.py
+++ b/django/core/checks/urls.py
@@ -63,7 +63,10 @@ def _load_all_namespaces(resolver, parents=()):
         if getattr(url, 'namespace', None) is not None
     ]
     for pattern in url_patterns:
-        current = parents + (getattr(pattern, 'namespace', ()),)
+        namespace = getattr(pattern, 'namespace', None)
+        current = parents
+        if namespace is not None:
+            current += (namespace,)
         namespaces.extend(_load_all_namespaces(pattern, current))
     return namespaces