Re: FYI: Set IFS in libtool for ash

[Gary V. Vaughan]

Hallo Ralf!

Ralf Wildenhues wrote:
> * Gary V. Vaughan wrote on Wed, Mar 16, 2005 at 03:40:29PM CET:
> >
> > I think keeping the intermediate variable is worthwhile.  Infact, ISTR 
> > having
> > used a \012\011\040 ordering to avoid accidental trailing whitespace 
> > cleanups
> > in the past (quite possibly dotted around the libtool source tree even 
> > now!).
> 
> $SP2NL, $NL2SP.
> 
> (am thinking, maybe I should use that in the pgi patch, looks much nicer).

That's not the same thing; All I meant is that because of trailing whitespace
stripping I have historically used (in your notation):

IFS='$
 ^I'$

>>If this patch is needed to address a known problem with ash, maybe it should
>>be submitted to the autoconf list too, for inclusion in AS_SHELL_SANITIZE?
> 
> Hmm.  ash does not sets IFS by default.  Why does it break?

That's very odd.  How can it do anything without IFS?  Do you mean that the
variable is not set, but the shell behaves as if it had a sensible whitespace
default?  All the more reason to push this upstream to autoconf IMHO.

> Hehe, you just pointed me toward something:  general.m4sh has:
> 
> | # Make sure IFS has a sensible default$
> | : ${IFS="$
> |  ^I"}$
> 
> (where $ is EOL and ^I is TAB).  This is _not_ sensible IMHO.  It really
> ought to be SPACE, TAB, NEWLINE, in exactly *that* order.

Is order significant (other than when addressing the ash bug you are working
on)?  Oh, wait, I see... during variable expansion, fields are separated by
$IFS[0].  Okay, I agree with you now.

> Thank you very much for pushing me towards a correct answer.
> 
> OK to apply this patch to remove my broken one and set IFS default
> sensibly?  Or should I rather set it unconditionally?

It is unconditional! ;-)

I agree with this patch.  Please apply.  This needs backporting to several
places that use my conditional `: ${IFS="...' breakage in branch-1-5 too.

Cheers,
        Gary.
-- 
Gary V. Vaughan      ())_.  address@hidden,gnu.org}
Research Scientist   ( '/   http://tkd.kicks-ass.net
GNU Hacker           / )=   http://www.gnu.org/software/libtool
Technical Author   `(_~)_   http://sources.redhat.com/autobook

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