Message 101900 - Python tracker

I have written a small patch, that solves the problem, but is disgusting. Could anyone tell me, how I can get some default encoding from Python internals (I have no idea where to look) and return it inside _PyUnicode_AsStringAndSize? Anyway, now when the error happens inside input, it raises an Exception properly. So now I only need to know, how to correct the bug in an elegant fashion.