[PATCH] python: fix error handling

[David Bremner]

On Sun, 22 Jan 2012 14:09:35 +0100, Justus Winter <4winter at informatik.uni-hamburg.de> wrote:
> Before 3434d1940 the return values of libnotmuch functions were
> declared as c_void_p and the code checking for errors compared the
> returned value to None, which is the ctypes equivalent of a NULL
> pointer.

Looks good to me as well. I pushed it to branch release. Could you make
a NEWS patch against branch release (i.e. start 0.11.1) ?

d