bug#29189: 25.3; Dired does not work with binary filenames

[Eli Zaretskii]

Ping!  Ping!  Ping!

> Date: Fri, 01 Dec 2017 10:41:47 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: vianchielfaura@gmail.com, 29189@debbugs.gnu.org
> 
> Ping!  Ping!  I'd _really_ like to fix this for Emacs 26, but I'm
> bothered by the potential adverse consequences of making changes in
> such a central piece of code.
> 
> Still hoping to get comments from Handa-san.
> 
> > Date: Fri, 24 Nov 2017 10:52:19 +0200
> > From: Eli Zaretskii <eliz@gnu.org>
> > Cc: vianchielfaura@gmail.com, 29189@debbugs.gnu.org
> > 
> > Ping!  Kenichi, any comments on this issue or the proposed patch?
> > 
> > > Date: Mon, 20 Nov 2017 20:15:55 +0200
> > > From: Eli Zaretskii <eliz@gnu.org>
> > > Cc: vianchielfaura@gmail.com, 29189@debbugs.gnu.org
> > > 
> > > > From: Andreas Schwab <schwab@suse.de>
> > > > Cc: Kenichi Handa <handa@gnu.org>,  vianchielfaura@gmail.com,  
> > > > 29189@debbugs.gnu.org
> > > > Date: Mon, 20 Nov 2017 10:48:09 +0100
> > > > 
> > > > > +           /* Copy raw bytes in their 2-byte forms as single 
> > > > > characters.  */
> > > > > +           if (CHAR_BYTE8_HEAD_P (*src) && nbytes > 0)
> > > > > +             {
> > > > > +               c = STRING_CHAR_ADVANCE (src);
> > > > 
> > > > CHAR_BYTE8_HEAD_P and STRING_CHAR_ADVANCE are only valid for multibyte
> > > > strings.  I don't think it makes sense to use them for unibyte strings.
> > > 
> > > Right you are, thanks.  Updated patch below.
> > > 
> > > diff --git a/src/coding.c b/src/coding.c
> > > index d790ad0..ac55f87 100644
> > > --- a/src/coding.c
> > > +++ b/src/coding.c
> > > @@ -7423,10 +7423,23 @@ decode_coding (struct coding_system *coding)
> > >  
> > >     while (nbytes-- > 0)
> > >       {
> > > -       int c = *src++;
> > > +       int c;
> > >  
> > > -       if (c & 0x80)
> > > -         c = BYTE8_TO_CHAR (c);
> > > +       /* Copy raw bytes in their 2-byte forms from multibyte
> > > +          text as single characters.  */
> > > +       if (coding->src_multibyte
> > > +           && CHAR_BYTE8_HEAD_P (*src) && nbytes > 0)
> > > +         {
> > > +           c = STRING_CHAR_ADVANCE (src);
> > > +           nbytes--;
> > > +         }
> > > +       else
> > > +         {
> > > +           c = *src++;
> > > +
> > > +           if (c & 0x80)
> > > +             c = BYTE8_TO_CHAR (c);
> > > +         }
> > >         coding->charbuf[coding->charbuf_used++] = c;
> > >       }
> > >     produce_chars (coding, Qnil, 1);
> > > 
> > >