bug#32034: 26.1; [PACTH] better xref-location-marker for imperfect file locations

[Eli Zaretskii <eliz@gnu.org>]

> From: João Távora <joaotavora@gmail.com>
> Cc: 32034@debbugs.gnu.org,  dgutov@yandex.ru
> Date: Mon, 02 Jul 2018 17:55:09 +0100
> 
> OK, let's give Dmitry time.  But, without trying to annoy you :-) there 
> are 3 parts to this:
> 
> 1. bug fix for when file doesn't exist (should error instead of making it)
> 2. bug fix for when file exists, but not location (it currently errors)
> 3. new feature, for robustness, search for id around landing point.
> 
> 1 and 2 were in my patch.  But now I'm assuming you want 1, 2 and 3 in
> emacs-26, in which case I'll try to base the id-searching bit from etags.

No.  I'm okay with your solution for 1 to go to emacs-26.  I had
reservations about your solution for 2, but now I understand it won't
affect the existing back-ends, so I'm okay with it on emacs-26, too
(but will probably suggest a clearer message text if Dmitry agrees
with the solution).

3 should indeed go to master.