From
http://mail.gnome.org/archives/gtk-devel-list/2001-August/msg00080.html:

My comment was:

Let's:

 * Always specify O_BINARY on platforms where it matters

 * Keep in mind the future possibility of something like:
   g_io_channel_set_newline_format (channel, "\r\n");

   This becomes most useful when we add encoding autodetection
   to glib - planned for a future version. Then we 
   can add newline detection like that, and get the effect
   of something similar to Emacs's newline handling. Emacs,
   when it reads a file, autodetects the newline format
   as part of encoding detection, so you get an encoding
   like EUC-JP-DOS, manipulates newlines internally as
   '\n' then uses the same newline format when writing
   out the file.
  
I think it is a good trait if the DOS and Unix versions of a
program by default produce identical output files. 

And not specifying O_BINARY corrupts encodings such UTF-16.

If we add the functionality to do read/write conversions
of newlines, it should happen on the UTF-8 side of the 
conversion, and should be cross-platform.

I believe this was decided upon, and we'll consider the
fact that Win32 doesn't specify O_BINARY here simply
an implementation bug.

since

2001-09-21  Hans Breuer  <hans@breuer.org>

	* glib/giowin32.c (g_io_channel_new_file) : always open
	in binary mode

resolved.

Fixed by Hans Breuer on 2001-09-21.