bug#23224: 25.0.92; Can xref-find-references work without a "project"?

[Eli Zaretskii <eliz@gnu.org>]

> From: Dmitry Gutov <dgutov@yandex.ru>
> Date: Wed, 6 Apr 2016 03:18:09 +0300
> 
> On 04/05/2016 06:23 PM, Eli Zaretskii wrote:
> 
> > +   (let* ((pr (project-current t nil 'noerror))
> > +          (roots (ignore-errors (project-roots pr)))
> > +          (eroots (ignore-errors (project-external-roots pr))))
> > +     ;; If we didn't find any project files in PR, default to PR
> > +     ;; itself as the project's single root.
> > +     (if (and (null roots) (null eroots))
> > +         (setq roots (list (expand-file-name pr))))
> > +     (append roots eroots))))
> 
> I'm going to assume you're teasing here. :)

A little bit.

> See the counter-proposal below, it should provide a more universal 
> benefit along the same line of reasoning. Unless we come upon situations 
> where we *do* want to abort with an error after asking the user for a 
> project and not finding a "real" one.

I don't know anything about project.el and its users, so I wasn't sure
such a change won't break something.  But if you say it's okay, I'll
stop worrying.

> If 'transient' doesn't sound great, alternative suggestions welcome.

"ad-hoc"?

Please go ahead and push.  Thanks.