On killing the client, ask the user about killing the server too

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### New features
 
+* [#1184](https://github.com/clojure-emacs/cider/pull/1184): When the user kills the repl buffer, CIDER will offer to kill the nrepl buffer and process too. Also, when the client (repl) process dies, the server (nrepl) process is killed too.
 * [#1182](https://github.com/clojure-emacs/cider/pull/1182): New command `cider-browse-instrumented-defs`, displays a buffer listing all defitions currently instrumented by the debugger.
 * [#1182](https://github.com/clojure-emacs/cider/pull/1182): Definitions currently instrumented by the debugger are marked with a red box in the source buffer.
 * [#1174](https://github.com/clojure-emacs/cider/pull/1174): New command `cider-run`, runs the project's `-main` function.

nrepl-client.el

@@ -626,8 +626,9 @@ older requests with \"done\" status."
 Display MESSAGE and if the process is closed kill the
 process buffer and run the hook `nrepl-disconnected-hook'."
   (message "nREPL: Connection closed (%s)" message)
-  (if (equal (process-status process) 'closed)
-      (run-hooks 'nrepl-disconnected-hook)))
+  (when (equal (process-status process) 'closed)
+    (run-hooks 'nrepl-disconnected-hook)
+    (nrepl--maybe-kill-server-buffer 'process-only)))
 
 
 ;;; Network
@@ -721,6 +722,19 @@ If NO-ERROR is non-nil, show messages instead of throwing an error."
 
 ;;; Client: Process Handling
 
+(defun nrepl--maybe-kill-server-buffer (&optional process-only)
+  "Kill the `nrepl-server-buffer' and its process, subject to user confirmation.
+If PROCESS-ONLY is non-nil, don't kill the buffer and don't ask for
+confirmation."
+  (when (and (buffer-live-p nrepl-server-buffer)
+             (or process-only
+                 (y-or-n-p "Also kill server process and buffer? ")))
+    (let ((proc (get-buffer-process nrepl-server-buffer)))
+      (when (process-live-p proc)
+        (kill-process proc))
+      (unless process-only
+        (kill-buffer nrepl-server-buffer)))))
+
 ;; `nrepl-start-client-process' is called from `nrepl-server-filter'. It
 ;; starts the client process described by `nrepl-client-filter' and
 ;; `nrepl-client-sentinel'.
@@ -748,6 +762,7 @@ process."
 
     (with-current-buffer client-buf
       (-when-let (server-buf (and server-proc (process-buffer server-proc)))
+        (add-hook 'kill-buffer-hook #'nrepl--maybe-kill-server-buffer 'append 'local)
         (setq nrepl-project-dir (buffer-local-value 'nrepl-project-dir server-buf)
               nrepl-server-buffer server-buf))
       (setq nrepl-endpoint `(,host ,port)