From 7b2563acc064586b674f68abd4eebd11b568e76b Mon Sep 17 00:00:00 2001
From: Jim Porter <jporterbugs@gmail.com>
Date: Sun, 9 Oct 2022 14:50:06 -0700
Subject: [PATCH 2/2] [WIP] Add hooks before/after deleting Emacs clients

* lisp/server.el (server-before-delete-client-functions)
(server-after-delete-client-functions): New defcustoms.
(server-delete-client): New argument ARG.  Handle 'nowait' value for
PROC.  Run the above hooks.
(server-save-buffers-kill-terminal): Extract buffer-saving code from
here...
(server-save-some-buffers): ... to this new function.
---
 lisp/server.el | 78 +++++++++++++++++++++++++++++++++-----------------
 1 file changed, 51 insertions(+), 27 deletions(-)

diff --git a/lisp/server.el b/lisp/server.el
index 5034a8e8c6..c1a64d6f32 100644
--- a/lisp/server.el
+++ b/lisp/server.el
@@ -191,6 +191,18 @@ server-done-hook
   "Hook run when done editing a buffer for the Emacs server."
   :type 'hook)
 
+;;;###autoload
+(defcustom server-before-delete-client-functions '(server-save-some-buffers)
+  "Functions to run before deleting an Emacs client.
+The functions are run with two arguments: the client process
+being deleted and an arg indicating whether to silently save."
+  :type 'hook)
+
+(defcustom server-after-delete-client-functions nil
+  "Functions to run after deleting an Emacs client.
+Functions are run with one argument: the client process just deleted."
+  :type 'hook)
+
 (defvar server-process nil
   "The current server process.")
 
@@ -318,13 +330,25 @@ server-with-environment
                  process-environment)))
        (progn ,@body))))
 
-(defun server-delete-client (proc &optional noframe)
+(defun server-delete-client (proc &optional noframe arg)
   "Delete PROC, including its buffers, terminals and frames.
 If NOFRAME is non-nil, let the frames live.
 Updates `server-clients'."
   (server-log (concat "server-delete-client" (if noframe " noframe")) proc)
-  ;; Force a new lookup of client (prevents infinite recursion).
-  (when (memq proc server-clients)
+  (cond
+   ((eq proc 'nowait)
+    (run-hook-with-args-until-success
+     'server-before-delete-client-functions proc arg)
+    (if (cdr (frame-list))
+	(delete-frame)
+      ;; If we're the last frame standing, kill Emacs.
+      (kill-emacs arg))
+    (run-hook-with-args 'server-after-delete-client-functions proc))
+
+   ;; Force a new lookup of client (prevents infinite recursion).
+   ((memq proc server-clients)
+    (run-hook-with-args-until-success
+     'server-before-delete-client-functions proc arg)
     (let ((buffers (process-get proc 'buffers)))
 
       ;; Kill the client's buffers.
@@ -373,7 +397,8 @@ server-delete-client
       (if (eq (process-status proc) 'open)
 	  (delete-process proc))
 
-      (server-log "Deleted" proc))))
+      (server-log "Deleted" proc)
+      (run-hook-with-args 'server-after-delete-client-functions proc)))))
 
 (defvar server-log-time-function #'current-time-string
   "Function to generate timestamps for `server-buffer'.")
@@ -1738,29 +1763,28 @@ server-save-buffers-kill-terminal
 
 If emacsclient was started with a list of filenames to edit, then
 only these files will be asked to be saved."
-  (if server-stop-automatically
-      (server-stop-automatically--handle-delete-frame (selected-frame))
-    (let ((proc (frame-parameter nil 'client)))
-      (cond ((eq proc 'nowait)
-	     ;; Nowait frames have no client buffer list.
-	     (if (cdr (frame-list))
-	         (progn (save-some-buffers arg)
-		        (delete-frame))
-	       ;; If we're the last frame standing, kill Emacs.
-	       (save-buffers-kill-emacs arg)))
-	    ((processp proc)
-	     (let ((buffers (process-get proc 'buffers)))
-	       (save-some-buffers
-	        arg (if buffers
-                        ;; Only files from emacsclient file list.
-		        (lambda () (memq (current-buffer) buffers))
-                      ;; No emacsclient file list: don't override
-                      ;; `save-some-buffers-default-predicate' (unless
-                      ;; ARG is non-nil), since we're not killing
-                      ;; Emacs (unlike `save-buffers-kill-emacs').
-		      (and arg t)))
-	       (server-delete-client proc)))
-	    (t (error "Invalid client frame"))))))
+  (let ((proc (frame-parameter nil 'client)))
+    (unless (or (eq proc 'nowait)
+                (processp proc))
+      (error "Invalid client frame"))
+    (server-delete-client proc nil arg)))
+
+(defun server-save-some-buffers (proc arg)
+  "Save buffers associated with PROC.
+A non-nil ARG means save all without questions (see
+`save-some-buffers')."
+  (if (eq proc 'nowait)
+      (save-some-buffers arg)
+    (let ((buffers (process-get proc 'buffers)))
+      (save-some-buffers
+       arg (if buffers
+               ;; Only files from emacsclient file list.
+	       (lambda () (memq (current-buffer) buffers))
+             ;; No emacsclient file list: don't override
+             ;; `save-some-buffers-default-predicate' (unless ARG is
+             ;; non-nil), since we're not killing Emacs (unlike
+             ;; `save-buffers-kill-emacs').
+	     (and arg t))))))
 
 (defun server-stop-automatically--handle-delete-frame (frame)
   "Handle deletion of FRAME when `server-stop-automatically' is used."
-- 
2.25.1