Re: [PATCH] bind_textdomain_codeset: don't return failure unless encoding isn't UTF-8

[Rich Felker <dalias@libc.org>]

On Fri, Dec 16, 2016 at 10:59:54PM -0500, Rich Felker wrote:
> On Sat, Dec 03, 2016 at 09:04:42PM -0600, Laine Gholson wrote:
> > returning null broke a vlc media player built with gettext support
> 
> > >From 2f79aa294db5d9230ad71298e3de4b5561b441be Mon Sep 17 00:00:00 2001
> > From: Laine Gholson <laine.gholson@gmail.com>
> > Date: Wed, 9 Nov 2016 20:19:00 -0600
> > Subject: [PATCH] bind_textdomain_codeset: don't return failure unless encoding isn't UTF-8
> > 
> > VLC isn't happy when bind_textdomain_codeset returns NULL
> > ---
> >  src/locale/bind_textdomain_codeset.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/src/locale/bind_textdomain_codeset.c b/src/locale/bind_textdomain_codeset.c
> > index 5ebfd5e..e5f3f52 100644
> > --- a/src/locale/bind_textdomain_codeset.c
> > +++ b/src/locale/bind_textdomain_codeset.c
> > @@ -5,7 +5,9 @@
> >  
> >  char *bind_textdomain_codeset(const char *domainname, const char *codeset)
> >  {
> > -	if (codeset && strcasecmp(codeset, "UTF-8"))
> > +	if (codeset && ((strcasecmp(codeset, "UTF-8") == 0) || (strcasecmp(codeset, "UTF8") == 0))) {
> > +		return "UTF-8";
> > +	} else if (codeset)
> >  		errno = EINVAL;
> >  	return NULL;
> >  }
> > -- 
> > 2.10.2
> 
> I think this needs some more thought. The documentation of the API is
> that a null pointer argument/result means "the locale's character
> encoding", and that the default is null; presumably even when the
> locale's codeset is "foo", null (default) and "foo" are still
> different states.
> 
> I don't actually like that, and don't think we should copy it --
> especially since, now that we also have a C locale with "ASCII" as the
> codeset, we _can't_ provide a codeset matching the locale in all cases
> -- but I also don't think it's right for the return value (null or
> "UTF-8") to depend on the argument rather than on the "previous state"
> like it's documented to.
> 
> There seem to be two possible reasonable behaviors:
> 
> 1. Diverge from the GNU behavior and treat textdomains as always-bound
>    to "UTF-8", regardless of whether bind_textdomain_codeset has been
>    called. The function would then return a null pointer with EINVAL
>    set for strings other than "UTF-8"/"UTF8", and would return "UTF-8"
>    for a valid or null-pointer argument.
> 
> 2. Keep a 1-bit state for each textdomain reflecting whether its
>    nominally in "default" mode or "UTF-8" mode. Either way the
>    original UTF-8 string would be returned; the only point of the
>    state would be providing a return value for bind_textdomain_codeset
>    that reflects how it was previously called.
> 
> Being that 2 is gratuitous complexity to do something stupid and
> meaningless, I'd lean towards 1, but I don't want to break anything
> that works. Does this seem safe to do?

Ping. Anyone else have thoughts on this?

Rich