bug#51993: 29.0.50; [PATCH] Killing emacsclient terminal with `server-stop-automatically' doesn't prompt to save files

[Jim Porter <jporterbugs@gmail.com>]

On 10/19/2022 11:23 PM, Eli Zaretskii wrote:
>> Date: Wed, 19 Oct 2022 20:14:38 -0700
>> Cc: larsi@gnus.org, 51993@debbugs.gnu.org, gregory@heytings.org
>> From: Jim Porter <jporterbugs@gmail.com>
>>
>>     a) if this is not the last client, behave the same as Emacs 28:
>> prompt to save files specified when starting "emacsclient", and then
>> delete that client.
>>
>>     b) if this *is* the last client, prompt the user to save everything
>> (as with 'save-buffers-kill-emacs'), and then delete the client + kill
>> the Emacs daemon.
> 
> You mean, in b), instead of just deleting the frame and leaving the
> daemon run, you want to shut down Emacs in its entirety, as if the
> user invoked kill-emacs?  I'm okay with that as an optional behavior,
> although I myself won't use it, as it's too dangerous.

Almost. I'd like it to be as if the user invoked 
'save-buffers-kill-emacs'; that is, before killing Emacs, prompt the 
user about everything[1] that might be lost by killing Emacs.

This already exists as an option -- (server-stop-automatically 
'delete-frame)[2], but I also find the current behavior too dangerous. 
My original message outlines one of the problems with the current 
implementation: it changes the behavior of (a) in my description above.

>   $ emacs -Q --daemon
>   $ emacsclient -a "" -c foo.txt
>   $ emacsclient -a "" -c bar.txt
> 
>   ;; In the first client frame:
>   foobar ;; Insert some text
>   C-x C-c
>   ;; Emacs prompts "Save file /path/to/foo.txt?..."
> 
> Now try the above, but call `(server-stop-automatically 'delete-frame)' first (or replace `delete-frame' with `kill-terminal'; it doesn't matter). In this case, Emacs doesn't prompt to save the file.

As mentioned earlier in this bug, I'm open to providing a patch to 
support options beyond the one I suggested (quoted at the beginning of 
this message), but I want to be sure we agree on what the options should 
look like so that I'm not breaking Gregory's (or anyone else's) 
preferred behavior here.

(Of course, all of this would remain opt-in. I don't want to change the 
default behavior here, since it would break years of established precedent.)

[1] Well, everything that Emacs usually asks about in a non-daemon 
configuration, anyway.

[2] It's not hooked up to Customize, though I don't think that would be 
too hard to do.