Issue #665761: functools.reduce() will no longer mask exceptions other

than TypeError raised by the iterator argument.  Also added a test to
check that zip() already behaves similarly.

Lib/test/test_builtin.py

@@ -1234,6 +1234,7 @@ class BuiltinTest(unittest.TestCase):
         class G:
             pass
         self.assertRaises(TypeError, zip, a, G())
+        self.assertRaises(RuntimeError, zip, a, TestFailingIter())
 
         # Make sure zip doesn't try to allocate a billion elements for the
         # result list when one of its arguments doesn't say how long it is.