bug#32194: [PATCH] Use Gnulib regex for lib-src

[Eli Zaretskii <eliz@gnu.org>]

> From: Paul Eggert <eggert@cs.ucla.edu>
> Cc: 32194@debbugs.gnu.org
> Date: Tue, 31 Jul 2018 11:21:38 -0700

I've not yet read the patch, will do soon.  But one aspect puzzles me:

> > 2. Do we really need to rename src/regex.c?  We could have 2 regex.c in
> >     separate directories, couldn't we?  If possible, I'd prefer not to
> >     rename files, as that makes VCS forensics more complicated.
> 
> Renaming src/regex.h works around problems with having two include files 
> src/regex.h and lib/regex.h that fight each other. I tried not renaming 
> src/regex.h at first, and then ran into problems and gave up; although I 
> surely could get it to work eventually, I figured that we'd continue to 
> have ongoing problems and so it would be better to bite the bullet.

I'm definitely missing something here, because I don't understand why
would these headers "fight" each other.  I thought that using

  #include "regex.h"

in src/regex.c should avoid any such "fights".  But since you no doubt
know about this feature, I wonder what did I miss that would prevent
that from working in this case.

Thanks.