bug#19466: 25.0.50; xref-find-def doesn't find C functions

[martin rudalics]

> "current" would be good, but "while finding xrefs" is iffy: we actually try 
to ignore instances of buffers being current while we display them (see xref--inhibit-mark-selected).

In any case please stick to the "`current' is a predicate for buffers
and `selected' is a predicate for windows and frames" convention.

>> And for `xref-quit' I'd describe the standard behavior first and the
>> KILL behavior afterwards.
>
> Would you like to suggest a specific wording?

I'll try to as soon as I know what it does.  Usually the "If optional
argument KILL is non-nil ..." idiom should appear after describing the
normal behavior.

>> Also I'm not sure it it's just cosmetics but
>> shouldn't the
>>
>>      (pcase-dolist (`(,buf . ,win) history)
>>        (when (and (window-live-p win)
>>                   (eq buf (window-buffer win)))
>>          (quit-window nil win)))
>>
>> precede the
>>
>>      (when kill
>>        (let ((xref--inhibit-mark-selected t)
>>              kill-buffer-query-functions)
>>          (dolist (buf xref--temporary-buffers)
>>            (unless (buffer-local-value 'xref--selected buf)
>>              (kill-buffer buf)))
>>          (setq xref--temporary-buffers nil)))
>>
>> part?
>
> Probably, but there's likely not much difference at the moment. xref
> doesn't pop any new windows,

... well, it did so here all the time ...

> so we shouldn't miss on deleting those when quitting temporary buffers.

Are you sure?  Suppose `xref-show-location-at-point' reused a window
showing a buffer A for showing a buffer B instead.  Now `xref-quit'
would kill B which should again show A instead.  But here you rely on
`kill-buffer' (that is `replace-buffer-in-windows') DTRT.

>> I can't test it currently because I always get
>>
>> Debugger entered--Lisp error: (args-out-of-range "" 0)
>>    help-function-arglist(#[257 "\300\207" ["(No location)"] 2 "(No
>> location)\n\n(fn ##)"] preserve-names)
>>    eieio--defmethod(xref-location-group nil xref-bogus-location #[257
>> "\300\207" ["(No location)"] 2 "(No location)\n\n(fn ##)"])
>
> I'm sure Someone(tm) will fix that right away. :)

For some value of "right away" :)

>>  > xref-goto-xref calls xref-quit without the KILL argument, so the
>> temporary buffers are not cleared if you make a choice and press RET.
>>
>> You can redisplay the *xref* buffer and provide the KILL there.
>
> You mean, for the user to switch to the buried xref buffer, then press C-u q? 
That's quite a few keypresses.

Then you probably want the KILL argument for `xref-goto-xref' too.

>>  >> previous-/next-history-element
>>  >
>>  > Not sure what these are.
>>
>> Something like typing M-. doing something else and typing M-. again.  At
>> this time up/down should get you the next/previous history elements of
>> your xref searches.
>
> You mean in the current interface? I'm confused.

When xref prompts me with

Find definitions of:

I'd expect to be able to browse my history of definitions I tried or
succeeded to find.

> With xref, we already sorta have both as features (C-u M-x 
xref-find-definitions and M-x xref-find-apropos).

OK.  They all work well in my gdb buffer.  So it shouldn't be too hard.

martin