Eli Zaretskii <eliz@gnu.org> writes:

> As for when we can't pop up a new window: would it be okay to reuse
> the current window only in that (hopefully, rare) case?

We could do that (I kinda like it) but it's actually harder to
implement, I think. We'd have to precisely control the order of
display-buffer fallbacks or repeat somewhere else the logic of
split-window-sensibly. I'd leave this for an implementation on master.

>> > As for quitting the XREF buffer when it's no longer needed: how about
>> > 'q', like other similar modes do, or some variety thereof?  "C-u RET"
>> > is too odd, almost outlandish in Emacs.
>> 
>> ’q’ is already taken by ’quit-window’ in *xref* buffers. It quits the
>> window and does nothing else. I’m looking for a command that quits *and*
>> goes to the target.
>
> How about 'Q'?

OK. I used 'Q'. And added 'TAB'. Because it's a bit what happens in
completion, which also selects and quits the transient completions
window.

I can take 'TAB' out, if you think it's a too high profile a key for
something like this.

> The problem with binding this "quit and go to reference" function to
> RET is that it is unlike any other similar feature we have: RET
> usually selects the item, but does not quit any windows.

I see. Well, I really don't have any strong arguments against that,
other than my feeling that, because *xref* is such a suprise window,
even unexpected, that criteria would somehow not apply here.  Or rather
it is superseeded by a superior mandate to not clutter the user's
windows with unexpected cruft.  As I mentioned, xref is rooted in SLIME,
and I believe (but I might be mistaken now), it used to work like that
in that program.

Anyway, I'm happy with the new command.

>> It’s a bugfix, so emacs-26.
>
> I'd need to see the patches in their last incarnation (if you already
> posted them, and nothing needs to be changed, a URL will be
> appreciated).  In general, this changes user-visible behavior in
> non-trivial ways, so it's borderline between a bugfix and a new
> feature.  But if the patches are small and simple enough, I guess they
> could be okay for emacs-26.

Let's hope they are. Attached are 4 patches. The 2 first are part of the
bugfix. Number 3 is the new xref-quit-and-goto-xref and number 4 are
documentation changes to the .texi manual (also fixed a small bug there)
and NEWS.