Code review comment for lp:~songofacandy/bzr/fix-524560

> INADA Naoki wrote:
> > I've found open with mode="wbN" is enough.
> > mode 'N' means NOINHERIT on win32 and ignored on Linux.
> >
> > Should I remove osutils.open and add 'N' flag directly?
>
> If that works, I would recommend it. But we need to make sure that it
> doesn't cause problems with Python 2.4.
>
> John
> =:->

I confirmed that glibc doesn't use 'N' for mode so it just ignore the 'N'.
But I don't know about other libc. (on Solaris, FreeBSD, MacOS, etc...)
So I think using 'N' only on win32 is safe.

Python 2.4 uses msvcrt71 (VC++2003?) and msdn doesn't document 'N' mode
and O_NOINHERIT. But os module in Python 2.4 have O_NOINHERIT so fcntl.h in
VC++2003 should have O_NOINHERIT.
I don't know the file is inherited to child process or not.
But I installed Python 2.4 and ``open('foo', 'wbN').write('foo')`` just works.