Re: [PATCH] include-next, warnings: support older autoconf

[Eric Blake]

On 07/26/2011 02:23 PM, Jim Meyering wrote:
> Stefano Lattarini wrote:
> > Hi Eric.  Hope you don't mind hearing a minor nit ...
> ...
> > > -       AS_VAR_SET([gl_next_header], ['<'gl_HEADER_NAME'>'])
> > > +       AS_VAR_SET(gl_next_header, ['<'gl_HEADER_NAME'>'])
> > IMHO you should add a comment here explaining why you are underquoting
> > (and thus implicitly stating that such underquoting is deliberate, not
> > a mistake); as in e.g.:
> >
> >      ...
> >      if test $gl_cv_have_include_next = yes; then
> >        dnl Autoconf 2.59 requires us to underquote here.
> >        AS_VAR_SET(gl_next_header, ['<'gl_HEADER_NAME'>'])
> >        ...
> >
> > And similarly for the other usages.
>
> I too was surprised not to see comments.
> I'd go even further and suggest to add a FIXME comment, so we'll
> know to revert this change once autoconf-2.59 is no longer supported.

Autoconf commit 25cb6b086 (2.61) was the first patch that made 
AS_VAR_SET properly expand $1 before inspecting it, although it wasn't 
until 2.64 that the interface was finally documented and declared 
stable.  So I'll add a comment that mentions 2.64 as the target prereq 
for a rewrite, to all 4 affected m4 files.

--
Eric Blake   address@hidden    +1-801-349-2682
Libvirt virtualization library http://libvirt.org