On 05/05/2012 05:18 AM, Eli Zaretskii wrote: > Diffutils 3.2 call xfreopen with its first argument NULL, expecting > the underlying reopen to handle this. However, the MS runtime does > not implement the Posix semantics of such a call,
POSIX says that such a call is implementation-defined, so technically,
mingw DOES implement the POSIX semantics (by defining that it is
unsupported). However, you are correct that it is annoying, and
something that gnulib could work around for easier coding.
> The following change fixes this:
>
> 2012-05-05 Eli Zaretskii <e...@gnu.org>
>
> * lib/freopen.c [_WIN32]: Include io.h and fcntl.h.
> (rpl_freopen) [_WIN32]: If the first argument is NULL, call
> _setmode to switch STREAM to either binary or text mode, as
> specified by MODE.
>
> --- lib/freopen.c~0 2011-09-02 01:35:11.000000000 +0300
> +++ lib/freopen.c 2012-05-05 13:46:36.389000000 +0300
> @@ -37,11 +37,23 @@ orig_freopen (const char *filename, cons
>
> #include <string.h>
>
> +#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
> +#include <io.h>
> +#include <fcntl.h>
> +#endif
> +
> FILE *
> rpl_freopen (const char *filename, const char *mode, FILE *stream)
> {
> #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
> - if (filename != NULL && strcmp (filename, "/dev/null") == 0)
> + if (filename == NULL)
> + {
> + if (strchr (mode, 'b'))
> + return _setmode (_fileno (stream), _O_BINARY) == -1 ? NULL : stream;
> + else
> + return _setmode (_fileno (stream), _O_TEXT) == -1 ? NULL : stream;
Shouldn't we be doing some sanity checking, as in ensuring that a
read-only stream is not being reopened with 'w', or a write-only stream
is not being reopened with 'r'? Also, shouldn't we be honoring 'w' vs.
'a' and adjusting the underlying fd's O_APPEND bit accordingly?
--
Eric Blake ebl...@redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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