Hash collision security issue

Lib/test/test_sys.py

 # -*- coding: iso-8859-1 -*-
 import unittest, test.support
 import sys, io, os
 import struct
 import subprocess
 import textwrap
 
 # count the number of test runs, used to create unique
 # strings to intern in test_intern()
 numruns = 0
@@ skipping 433 matching lines @@
     def test_sys_flags(self):
         self.assertTrue(sys.flags)
         attrs = ("debug", "division_warning",
                  "inspect", "interactive", "optimize", "dont_write_bytecode",
                  "no_user_site", "no_site", "ignore_environment", "verbose",
                  "bytes_warning", "hash_randomization")
         for attr in attrs:
             self.assertTrue(hasattr(sys.flags, attr), attr)
             self.assertEqual(type(getattr(sys.flags, attr)), int, attr)
         self.assertTrue(repr(sys.flags))
-        self.assertEqual(len(sys.flags), len(attrs))
+        # NOTE: len(sys.flags) is #flags - 1 in 3.1 for backwards compatibility
+        self.assertEqual(len(sys.flags), len(attrs) - 1)
 
     def test_clear_type_cache(self):
         sys._clear_type_cache()
 
     def test_ioencoding(self):
         env = dict(os.environ)
 
         # Test character: cent sign, encoded as 0x4A (ASCII J) in CP424,
         # not representable in ASCII.
 
@@ skipping 316 matching lines @@
         try:
             raise TypeError
         except TypeError:
             tb = sys.exc_info()[2]
             # traceback
             if tb != None:
                 check(tb, size(h + '2P2i'))
         # symtable entry
         # XXX
         # sys.flags
-        check(sys.flags, size(vh) + self.P * len(sys.flags))
+        # NOTE: len(sys.flags) is #flags - 1 in 3.1 for backwards compatibility
+        check(sys.flags, size(vh) + self.P * (len(sys.flags) + 1))
 
     def test_getfilesystemencoding(self):
         import codecs
 
         def check_fsencoding(fs_encoding):
             if sys.platform == 'darwin':
                 self.assertEqual(fs_encoding, 'utf-8')
             elif fs_encoding is None:
                 return
             codecs.lookup(fs_encoding)
@@ skipping 28 matching lines @@
         try:
             self.assertRaises(LookupError, sys.setfilesystemencoding, "xxx")
         finally:
             sys.setfilesystemencoding(old)
 
 def test_main():
     test.support.run_unittest(SysModuleTest, SizeofTest)
 
 if __name__ == "__main__":
     test_main()