Re: Looking through multibyte_char_to_unibyte

[Eli Zaretskii]

> Date: Sun, 22 Jun 2014 20:20:30 +0300
> From: Eli Zaretskii <address@hidden>
> Cc: address@hidden, address@hidden
> 
> > Date: Sun, 22 Jun 2014 21:09:19 +0400
> > From: Dmitry Antipov <address@hidden>
> > Cc: Kenichi Handa <address@hidden>
> > 
> > int
> > multibyte_char_to_unibyte (int c)
> > {
> >    if (c < 0x80)
> >      return c;
> >    if (((c) > 0x3FFF7F))
> >      return (((c) > 0x3FFF7F) ? (c) - 0x3FFF00 : multibyte_char_to_unibyte 
> > (c));
> >    return (c & 0xFF);
> > }
> > 
> > Is this a subtle trick which I just can't understand and explain, or 
> > something
> > is really wrong with this?
> 
> What do you think this function intends to do?  IOW, how would you go
> about "converting a multibyte character to unibyte", something that is
> not possible in principle?

Wait, you probably asked about the recursive call to
multibyte_char_to_unibyte, is that right?  If so, that branch is never
taken, and will be optimized away by any reasonable compiler.