Issue12541 - Add UserWarning for unquoted realms
diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py
index 6cc78ed..96bb8d7 100644
--- a/Lib/urllib/request.py
+++ b/Lib/urllib/request.py
@@ -934,6 +934,9 @@
                 mo = AbstractBasicAuthHandler.rx.search(authreq)
                 if mo:
                     scheme, quote, realm = mo.groups()
+                    if quote not in ['"',"'"]:
+                        warnings.warn("Basic Auth Realm was unquoted",
+                                      UserWarning, 2)
                     if scheme.lower() == 'basic':
                         response = self.retry_http_basic_auth(host, req, realm)
                         if response and response.code != 401: