Fix matching empty string

Author: barneygale

Lib/nturl2path.py

@@ -26,7 +26,7 @@ def url2pathname(url):
         # Skip past extra slash before UNC drive in URL path.
         url = url[1:]
     else:
-        if url[:1] == '/' and url[2:3] in ':|':
+        if url[:1] == '/' and url[2:3] in (':', '|'):
             # Skip past extra slash before DOS drive in URL path.
             url = url[1:]
         if url[1:2] == '|':

Lib/test/test_urllib.py

@@ -1484,6 +1484,7 @@ def test_pathname2url_nonascii(self):
                          'test specific to Windows pathnames.')
     def test_url2pathname_win(self):
         fn = urllib.request.url2pathname
+        self.assertEqual(fn('/'), '\\')
         self.assertEqual(fn('/C:/'), 'C:\\')
         self.assertEqual(fn("///C|"), 'C:')
         self.assertEqual(fn("///C:"), 'C:')