[issue20437] Use Py_CLEAR to safe clear attributes

[Serhiy Storchaka]

Changes by Serhiy Storchaka <storchaka at gmail.com>:


Added file: http://bugs.python.org/file33796/py_clear-2.7.patch

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue20437>
_______________________________________