[issue21193] pow(a, b, c) should not raise TypeError when b is negative and c is provided

[Ned Deily]

Changes by Ned Deily <nad at acm.org>:


----------
nosy: +mark.dickinson
versions:  -Python 3.1, Python 3.2, Python 3.3

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue21193>
_______________________________________