Subject: bug#58909: 29.0.50; [PATCH] Deleting the last frame of an emacsclient doesn't ask to save

From: Jim Porter <[email-masked]>
Date: Wed, 2 Nov 2022 15:09:21 -0700

On 11/2/2022 1:09 PM, Eli Zaretskii wrote:
>> 'server-delete-client' is called in a bunch of spots, so at minimum, I'd
>> want to be extra-careful that prompting doesn't break one of those
>> cases.
> 
> Sorry, I meant server-handle-delete-frame.

Oh, ok. That would be easy then. But since your preference was to just 
leave things as they are, let's not make this change. I can adjust 
things locally without it.

>>>> If starting the server activates a minor mode, then Emacs can use a
>>>> minor-mode keymap for server-mode. [snip]
>>>
>>> I'm fine with doing that, but we must also make sure this mode is
>>> turned on when users invoke server-start interactively.
>>
>> I think that makes sense, and it should be fairly straightforward. I'll
>> work on a patch for this.
> 
> Thanks.

Ok, here's a patch for that. It just sets the 'server-mode' variable 
(and 'global-minor-modes' to be polite) inside 'server-start'. It would 
probably be more elegant if we could make 'server-start' just call 
'(server-mode)' (instead of the other way around like it is now), but I 
think it would be hard to do that while staying 100% compatible. Does 
this seem ok?

From 687f2ab4803c41f6a33280048243b0962816d2b5 Mon Sep 17 00:00:00 2001
From: Jim Porter <[email-masked]>
Date: Wed, 2 Nov 2022 09:22:43 -0700
Subject: [PATCH] Enable/disable 'server-mode' when starting/stopping the
 server

* lisp/server.el (server-mode-keymap): New keymap...
(server-mode): ... use it.
(server-start): Update the 'server-mode' variable (and sync to
'global-minor-modes') when starting/stopping the server.
---
 lisp/server.el | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/lisp/server.el b/lisp/server.el
index 90d97c1538..18548186b1 100644
--- a/lisp/server.el
+++ b/lisp/server.el
@@ -670,7 +670,6 @@ server-start
                             "/tmp/")
                  (ignore-errors
                    (delete-directory (file-name-directory server-file))))))
-         (setq server-mode nil) ;; already set by the minor mode code
          (display-warning
           'server
           (concat "Unable to start the Emacs server.\n"
@@ -688,7 +687,9 @@ server-start
       (if leave-dead
 	  (progn
 	    (unless (eq t leave-dead) (server-log (message "Server stopped")))
-	    (setq server-process nil))
+            (setq server-mode nil
+                  global-minor-modes (delq 'server-mode global-minor-modes)
+                  server-process nil))
 	;; Make sure there is a safe directory in which to place the socket.
 	(server-ensure-safe-dir server-dir)
 	(when server-process
@@ -728,6 +729,8 @@ server-start
 			       :plist '(:authenticated t)))))
 	  (unless server-process (error "Could not start server process"))
 	  (process-put server-process :server-file server-file)
+          (setq server-mode t)
+          (push 'server-mode global-minor-modes)
 	  (when server-use-tcp
 	    (let ((auth-key (server-get-auth-key)))
 	      (process-put server-process :auth-key auth-key)
@@ -796,6 +799,10 @@ server-running-p
 	t)
     (file-error nil)))
 
+;; This keymap is empty, but allows users to define keybindings to use
+;; when `server-mode' is active.
+(defvar-keymap server-mode-keymap)
+
 ;;;###autoload
 (define-minor-mode server-mode
   "Toggle Server mode.
@@ -805,6 +812,7 @@ server-mode
 `server-start' for details."
   :global t
   :version "22.1"
+  :keymap server-mode-keymap
   ;; Fixme: Should this check for an existing server socket and do
   ;; nothing if there is one (for multiple Emacs sessions)?
   (server-start (not server-mode)))
-- 
2.25.1