Merged revisions 75470 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/trunk

........
  r75470 | mark.dickinson | 2009-10-17 22:46:32 +0100 (Sat, 17 Oct 2009) | 1 line

  Protect against attempts to replace PyNumber_Add with PyNumber_InPlaceAdd in builtin sum
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Lib/test/test_builtin.py

@@ -1151,6 +1151,10 @@ class BuiltinTest(unittest.TestCase):
                 raise ValueError
         self.assertRaises(ValueError, sum, BadSeq())
 
+        empty = []
+        sum(([x] for x in range(10)), empty)
+        self.assertEqual(empty, [])
+
     def test_type(self):
         self.assertEqual(type(''),  type('123'))
         self.assertNotEqual(type(''), type(()))