Allow / character in username,password fields in _PROXY envvars. (#23973)

diff --git a/Lib/test/test_urllib2.py b/Lib/test/test_urllib2.py
index 12ad6ae..9db23e6 100644
--- a/Lib/test/test_urllib2.py
+++ b/Lib/test/test_urllib2.py
@@ -1851,9 +1851,17 @@ def test_parse_proxy(self):
              ('ftp', 'joe', 'password', 'proxy.example.com')),
             # Test for no trailing '/' case
             ('http://joe:password@proxy.example.com',
-             ('http', 'joe', 'password', 'proxy.example.com'))
+             ('http', 'joe', 'password', 'proxy.example.com')),
+            # Testcases with '/' character in username, password
+            ('http://user/name:password@localhost:22',
+             ('http', 'user/name', 'password', 'localhost:22')),
+            ('http://username:pass/word@localhost:22',
+             ('http', 'username', 'pass/word', 'localhost:22')),
+            ('http://user/name:pass/word@localhost:22',
+             ('http', 'user/name', 'pass/word', 'localhost:22')),
         ]
 
+
         for tc, expected in parse_proxy_test_cases:
             self.assertEqual(_parse_proxy(tc), expected)