Re: MPS: Win64 testers?

[Pip Cet <pipcet@protonmail.com>]

"Quang Kien Nguyen" <kien.n.quang@gmail.com> writes:

>> > As for the code in question, if I understand it correctly, the current
>> > Windows idiom would be simply (I assume _open_osfhandle clears the flag?):
>> >
>> > SetHandleInformation (GetStdHandle (STD_INPUT_HANDLE), HANDLE_FLAG_INHERIT,
>> > 0);
>>
>> I'm not sure you can do this without closing the stream, since the
>> program has already started by that time. And SetHandleInformation is
>> only available since Windows 2K, so we'd need to call it through a
>> function pointer.
> I think using the SetHandleInformation here should be appropriate.
> The implementation of _fdopen in ucrt is similar to Wine, it starts
> looking from ` _IOB_ENTRIES` (== 3) stream. Here is the extracted source
> code https://github.com/huangqinjin/ucrt/blob/master/stdio/stream.cpp#L12

Thanks!

> So, once we close the `stdin/out/err`, there's noone who get assigned
> back to those streams, and then the final close in `sys_dep.c` will fail
> for UCRT.

Indeed, that's what I'm seeing with wine, too.  BTW, the Wine issue has
been fixed and it now faithfully emulates the MSVCRT behavior when
pretending to be ancient Windows.

> I have tested with my own UCRT64 build of Emacs at
> https://github.com/kiennq/emacs-build/releases/tag/v31.276.20240805.2332f50,
> With the patch of
> https://github.com/kiennq/emacs-build/edit/main/patches/0001-init_winntproc-Use-SetHandleInformation-to-set-NOINH.patch

https://github.com/kiennq/emacs-build/blob/main/patches/0001-init_winntproc-Use-SetHandleInformation-to-set-NOINH.patch
is visible here.

> The SetHandleInformation returns no error even without streams being
> closed.

We still need to call it through a function pointer to support Windows
98/95, right?  And, of course, once we've done that, we need to find
testers for most or all Windows versions to verify the streams are
indeed not being inherited.

Would you be willing and able to help with that, maybe?

Pip