Re: Comparing binary files with Diff 3.2 compiled with MinGW

[Bruno Haible]

Eli Zaretskii wrote:
> At some point between Diffutils 2.8.7 and 2.9, the code that handles
> binary files was removed from io.c.  The changes below resurrect the
> correct behavior.  To accomplish this, I needed to add the binary-io
> module, and make changes there as well.

I can't comment on the rationale of the diffutils/src/io.c change in
http://git.savannah.gnu.org/gitweb/?p=diffutils.git;a=commitdiff;h=91b8605708cf2d7c49679a46a80b4039167da2cd

But regarding <binary-io.h>, I am unhappy about another macro UNSET_BINARY.
If you need
  1. to reset the value to O_TEXT,
  2. to get the previous value in return,
then I would suggest to use a function

  int setmode (int fd, int o_mode);

exactly like in Cygwin, so that no code is needed on Cygwin.

If we had the chance to design a new API would prefer

  bool set_binary_mode (int fd, bool binary);

but this interface would have no significant advantage over the well-known
Cygwin one.

> --- lib/binary-io.h~1 2012-05-12 17:31:43.639250000 +0300
> +++ lib/binary-io.h   2012-05-12 18:19:53.842375000 +0300

> -# if defined __EMX__ || defined __DJGPP__ || defined __CYGWIN__
> +# if defined __EMX__ || defined __DJGPP__ || defined __CYGWIN__ || defined 
> _WIN32
>  #  include <io.h> /* declares setmode() */
>  # else
>  #  define setmode _setmode

This change is wrong. The MSVC headers don't unconditionally declare
'setmode' and 'fileno'.

And, please, for consistency with the other codes, use
"defined _WIN32 || defined __WIN32__", not just "defined _WIN32".

Bruno