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From: Junio C Hamano <gitster@pobox•com>
To: Johannes Schindelin <johannes.schindelin@gmx•de>
Cc: git@vger•kernel.org, Johannes Sixt <j6t@kdbg•org>
Subject: Re: [PATCH] mingw: emulate write(2) that fails with a EPIPE
Date: Wed, 16 Dec 2015 10:35:32 -0800	[thread overview]
Message-ID: <xmqq7fkedyx7.fsf@gitster.mtv.corp.google.com> (raw)
In-Reply-To: <01da36219c18373f8507e19035e141d7e56b2d18.1450267413.git.johannes.schindelin@gmx.de> (Johannes Schindelin's message of "Wed, 16 Dec 2015 13:14:57 +0100 (CET)")

Johannes Schindelin <johannes.schindelin@gmx•de> writes:

> 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.

Makes sense.

>  int mingw_fflush(FILE *stream);
>  #define fflush mingw_fflush
>  
> +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
> +

It strikes me a bit strange to see this inlined compared to what
appears in the context.  Shouldn't the implementation be done in
compat/mingw.c like all others?

>  int mingw_access(const char *filename, int mode);
>  #undef access
>  #define access mingw_access

  reply	other threads:[~2015-12-16 18:35 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-16 12:14 [PATCH] mingw: emulate write(2) that fails with a EPIPE Johannes Schindelin
2015-12-16 18:35 ` Junio C Hamano [this message]
2015-12-17  9:39   ` Johannes Schindelin
2015-12-17 16:40     ` Junio C Hamano
2015-12-17 17:08       ` Johannes Schindelin
2015-12-16 19:47 ` Eric Sunshine
2015-12-16 20:36   ` Junio C Hamano
2015-12-17  9:37   ` Johannes Schindelin
2015-12-17 17:08 ` [PATCH v2] " Johannes Schindelin
2015-12-17 19:22   ` Junio C Hamano
2015-12-18 16:10     ` Johannes Schindelin
2015-12-18 20:57   ` Johannes Sixt
2015-12-21 16:59     ` Junio C Hamano

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