[issue8847] crash appending list and namedtuple

[STINNER Victor]

STINNER Victor added the comment:

When Python is compiled by Visual Studio 10 in PGUpdate mode, duplicated functions are merged to become the same unique function. The C code of wrap_binaryfunc() and wrap_binaryfunc_l() functions is the same and so both functions get the same address.

For "class List(list): pass", type_new() fills type->tp_as_number->nb_add to list_concat() because "d->d_base->wrapper == p->wrapper" is True whereas it should be False (wrap_binaryfunc vs wrap_binaryfunc_l).

A workaround is to use a different code for wrap_binaryfunc() and wrap_binaryfunc_l(). A real fix is to use something else than the address of the wrapper to check the type of the operator (left, right, or the 3rd type).

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nosy: +haypo

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue8847>
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