> I don't understand whether you are proposing to include the patch into Python as-is;

I think Richard is well aware of the constraints you specify and current patch was meant as a proof of concept; to show that all tests pass with such a change. Of course that's only my belief and we shall see what Richard has to say.

> That said, having maximum sharing when opnening files sounds fine to me.

Good to hear. However I started to wonder if we are ready for all consequences of this. For example taking into account what Richard noted in http://bugs.python.org/issue14243, specifically:

> Unfortunately using O_TEMPORARY is the only way allowed by msvcrt to
> get FILE_SHARE_DELETE, even though it also has the orthogonal effect
> of unlinking the file when all handles are closed.

forces programs which would like to open a file being opened at the same time by Python code (by means of built-in open() or os.open() with default arguments) to either use O_TEMPORARY when using msvcrt or to go low level and use CreateFile() Win32 API function with FILE_SHARE_DELETE flag. Are we ok with it?