Re: [PATCH] mingw: emulate write(2) that fails with a EPIPE

> On Windows, when writing to a pipe fails, errno is always
> EINVAL. However, Git expects it to be EPIPE.
>
> According to the documentation, there are two cases in which write()
> triggers EINVAL: the buffer is NULL, or the length is odd but the mode
> is 16-bit Unicode (the broken pipe is not mentioned as possible cause).
> Git never sets the file mode to anything but binary, therefore we know
> that errno should actually be EPIPE if it is EINVAL and the buffer is
> not NULL.
>
> See https://msdn.microsoft.com/en-us/library/1570wh78.aspx for more
> details.
>
> This works around t5571.11 failing with v2.6.4 on Windows.
>
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> ---
> diff --git a/compat/mingw.h b/compat/mingw.h
> @@ -210,6 +210,24 @@ FILE *mingw_freopen (const char *filename, const char *otype, FILE *stream);
> +static inline ssize_t mingw_write(int fd, const void *buf, size_t len)
> +{
> +       ssize_t result = write(fd, buf, len);
> +
> +       if (result < 0 && errno == EINVAL && buf) {

> +               /* check if fd is a pipe */
> +               HANDLE h = (HANDLE) _get_osfhandle(fd);
> +               if (GetFileType(h) == FILE_TYPE_PIPE)
> +                       errno = EPIPE;
> +               else
> +                       errno = EINVAL;

> +       }
> +
> +       return result;
> +}
> +
> +#define write mingw_write
> +
> --
> 2.6.3.windows.1.300.g1c25e49