[libvirt] [PATCH 3/3] m4: Check for rl_completion_quote_character

[Andrea Bolognani]

On Mon, 2018-01-15 at 16:36 +0100, Michal Privoznik wrote:
> > So, one way to solve this once and for all would be to:
> > 
> >   * try looking up readline through pkg-config. If that works,
> >     then we already know we're compiling against a recent
> >     readline version and everything will work;
> 
> I just found out that this will not work - even though there is
> readline.pc.in in the readline repo, they are lacking rule to install
> the .pc file. So nobody ships that. For instance, on my rawhide box:
> 
> [root at fedora ~]# rpm -q readline
> readline-7.0-5.fc26.x86_64
> [root at fedora ~]# rpm -ql readline | grep \.pc
> [root at fedora ~]#

Ouch.

(Note the .pc file would be in the readline-devel package, not in
the runtime one. Still, I've checked on my Rawhide guest and it's
not there.)

At least FreeBSD ships it, though:

  # pkg list readline | grep pc$
  /usr/local/libdata/pkgconfig/readline.pc

Not sure about brew. Not having access to a macOS box is really
annoying in this kind of scenario.

> >   * if readline's pkg-config file is not available, try linking
> >     against it the old way. This will succeed on oldish versions
> >     like the one shipped with CentOS but fail because of missing
> >     functions on macOS.
> 
> I should have commented earlier too - what good it is to switch to
> pkg-config if we're keeping the old way of detecting the library (with
> this patch included) anyway?

We wouldn't need to include this patch: we could just assume
a readline new enough to provide a .pc file contains all the
functionality we need.

> Therefore I think we should merge this patch and switch to pkg-config
> later (when distros have it).

Well, we're running out of time for 4.0.0 anyway, so

  Reviewed-by: Andrea Bolognani <abologna at redhat.com>

to your patch and let's work on a better solution, assuming one
is even possible, later :)

-- 
Andrea Bolognani / Red Hat / Virtualization