Index: Lib/test/test_urllib.py
===================================================================
--- Lib/test/test_urllib.py	(revision 76700)
+++ Lib/test/test_urllib.py	(working copy)
@@ -8,6 +8,7 @@
 import unittest
 from test import support
 import os
+import random
 import tempfile
 
 def hexescape(char):
@@ -525,6 +526,13 @@
         self.assertEqual(expect, result,
                          "using quote_plus(): %r != %r" % (expect, result))
 
+    def test_quote_leak(self):
+        # bug 5596 - highlight the refleak in the internal _safe_quoters cache
+        safe = ''.join(chr(random.randrange(128)) for i in '123456')
+        text = 'abcdefghijklmnopqrstuvwxyz'
+        result = urllib.parse.quote(text, safe=safe)
+        self.assertEqual(result, text)
+
 class UnquotingTests(unittest.TestCase):
     """Tests for unquote() and unquote_plus()
 
Index: Lib/urllib/parse.py
===================================================================
--- Lib/urllib/parse.py	(revision 76700)
+++ Lib/urllib/parse.py	(working copy)
@@ -41,8 +41,9 @@
 _parse_cache = {}
 
 def clear_cache():
-    """Clear the parse cache."""
+    """Clear the parse cache and the quoters cache."""
     _parse_cache.clear()
+    _safe_quoters.clear()
 
 
 class ResultMixin(object):