This test no longer leaks, and test_generators sufficiently tests it to

prevent unreported regression.

Lib/test/leakers/test_tee.py

-
-# Test case taken from test_generators
-# See http://mail.python.org/pipermail/python-dev/2005-November/058339.html
-
-from itertools import tee
-import gc
-
-def leak():
-    def inner():
-        def fib():
-            def yield_identity_forever(g):
-                while 1:
-                    yield g
-            def _fib():
-                for i in yield_identity_forever(head):
-                    yield i
-            head, tail, result = tee(_fib(), 3)
-            return result
-
-        x = fib()
-        x.next()
-    inner()
-    gc.collect() ; gc.collect()
-    # this is expected to return 0
-    return gc.collect()