bug#68958: [PATCH] Support bookmarking Xref results buffers

[Dmitry Gutov <dmitry@gutov.dev>]

On 12/02/2024 20:31, Juri Linkov wrote:
>>>>> I once tried to use 'revert-buffer-function' to restore
>>>>> xref buffers from the desktop, but abandoned the idea.
>>>>> Not because xref.el doesn't set 'revert-buffer-function'.
>>>>> But because it would take too much time to restore
>>>>> the desktop while it will rerun all saved xref buffers.
>>>>> OTOH, saving an xref bookmark makes more sense.
>>>>> And probably your patch will help to implement
>>>>> 'revert-buffer-function' for xref as well.
>>>> I don't think bookmark would save the whole buffer contents. Would it?
>>>> Otherwise, re-running the search(es) seems inevitable.
>>> Indeed, saving the buffer contents of transient buffers
>>> either to the bookmark or to the desktop makes no sense.
>>> So re-running the command is inevitable.
>>> But then I can't imagine how would it be possible
>>> to move point to its saved location when initially
>>> a restored buffer is empty before re-running the command.
>> As long as the search is performed synchronously, first you "revert" the
>> buffer and then move point. Right?
> Sorry, I forgot that xref is not asynchronous as rgrep.
> But this is not a problem: most of the time xref delay
> is negligible.  Still would not want to run it while
> restoring the desktop.  But from a bookmark is fine.

Desktop could use some deferring strategy - e.g. delaying the search 
until the buffer is shown.

Anyway, that's secondary to being able to restore such a buffer at all.