Re: HEAD: func_show_eval shell expansion issue

[Noah Misch]

On Thu, Aug 25, 2005 at 08:41:12AM +0200, Ralf Wildenhues wrote:
> * Noah Misch wrote on Thu, Aug 25, 2005 at 12:28:35AM CEST:
> > I wrote a goofy fix for this shortly after Gary and I finalized the current
> > implementation.  The problem seemed minor, so I did not contribute said 
> > goofy
> > fix at the time.
> 
> Care to contribute it now?

I'll discuss this under separate cover.

> There's one thing I still don't understand: before, we had a bunch of
>   $echo "$cmd"
>   $run eval "$cmd"
> 
> which we now replaced with func_show_eval, which does
> func_quote_for_expand only to have yet another eval in the echoing path.
> 
> Why not just drop func_quote_for_expand and the extra eval?
> (I'm pretty sure I'm overlooking something; it's that I'd like to know
> what I am overlooking.)

The hope was to expand parameters in the command for the user.

These threads provide some background:
http://lists.gnu.org/archive/html/libtool-patches/2004-10/msg00264.html
http://lists.gnu.org/archive/html/libtool/2004-10/msg00081.html

> *time passes* OK, this seems to break a lot of uses of func_show_eval.
> But _then_ I see a fundamental problem in the way we use func_show_eval:
> We pass it arguments with different levels of expanded-ness.  This is
> a subtle problem and needs to be fixed, IMHO.  Am I missing something?

What do you mean, different levels of expanded-ness?

> > This surprises me a lot.  All the relevant functionality is in general.m4sh,
> > and the diff between HEAD and branch-2-0 does not show anything that would
> > cause this behavior change.
> 
> The answer to this is trivial: func_show_eval is defined but not used at
> all in branch-2-0 ltmain.m4sh;  func_quote_for_expand is used only once.

Ah; that does explain it.

> > Perhaps $2 and $3 are empty at this call site in
> > branch-2-0, but not in HEAD, so the output is still wrong, but the 
> > difference
> > is less obvious?  Would you confirm?
> 
> That makes this question obsolete, right?

Yes.