[Python-Dev] Preserving the blamelist

[Tim Peters]

[Neal Norwitz]
> ...
> I'm concerned about the negative ref leak in test_contextlib.  I
> wonder if this was a result of PJE's fix for generators?

I don't know, but if you do

while 1:
    test_contextlib.test_main()
    gc.collect()

under a debug build it eventually (> 500 iterations) crashes with

    Fatal Python error: deallocating None

That's a pretty good clue ;-)  The

	Py_XDECREF(gen->gi_frame);

in gen_dealloc() is on the call stack at the time, and cyclic gc is active.