[PATCH] msvcrt: Fix fscanf return when EOF is immediately after an end of line.

[Erich E. Hoover]

Wow, thanks Piotr!

Are you sure you were testing against msvcr90?  I just ran a couple
tries against the testbot and I see it doing what we expect on
msvcr120, but msvcr90 it's giving 0 (
https://testbot.winehq.org/JobDetails.pl?Key=57997 ).  I'll go through
and establish exactly what version they fixed this in, but I want to
make sure that there isn't something weird going on with msvcr90.

Best,
Erich

On Fri, Oct 18, 2019 at 12:45 PM Piotr Caban <piotr.caban at gmail.com> wrote:
>
> Hi Erich,
>
> I've done some testing and here's what I found:
>   - swscanf in msvcrt returns 0 as you have described
>   - swscanf in msvcr90 returns WEOF
>   - __stdio_common_vswscanf in ucrtbase returns WEOF
>
> It looks like there's a bug/backward compatibility code in native
> msvcrt.dll. It would be good to do some more testing on different
> *wscanf functions in msvcrt.
>
> I guess that the way to go is to:
>   - add swscanf tests in msvcrt (you can use L"" there)
>   - add swscanf tests in one of the newer dlls
>   - make the implementation change specific to newer versions of C-runtime
>
> Hope it helps,
> Piotr
>
> On 10/18/19 5:40 PM, Erich E. Hoover wrote:
> > Hi Piotr,
> >
> > I just ran the widecharstring case on the testbot (
> > https://testbot.winehq.org/JobDetails.pl?Key=57989 ) and that seems to
> > return 0 instead of WEOF...  Are you alright with just adding this
> > test to demonstrate that it doesn't work the same way?  Failing test:
> > ===
> >      buffer[0] = ' ';
> >      buffer[1] = '\t';
> >      buffer[2] = '\n';
> >      buffer[3] = '\n';
> >      buffer[4] = 0;
> >      ret = swscanf(buffer, formats, results);
> >      ok( ret == (short)WEOF, "ret = %d\n", ret );
> > ===
> >
> > Best,
> > Erich
> >
> > On Fri, Oct 18, 2019 at 3:49 AM Piotr Caban <piotr.caban at gmail.com> wrote:
> >>
> >> Hi Erich,
> >>
> >> On 10/17/19 5:41 PM, Erich E. Hoover wrote:
> >>> +                    /* if we have reached the EOF and output nothing then report EOF */
> >>> +                    if (nch==_EOF_  && rd==0 && st==0) {
> >> _UNLOCK_FILE_(file);
> >>> +                        return _EOF_RET;
> >>> +                    }
> >>
> >> Please also update the widecharstring case.
> >>
> >>> +    fp = fopen(file_name, "wb");
> >>> +    ok(fp, "fp = %p\n", fp);
> >> This cause compilation warning.
> >>
> >> Thanks,
> >> Piotr
>