Fix sesman-restart regression issue with SIGHUP handling in server

CHANGELOG.md

@@ -11,6 +11,7 @@
 - [#3341](https://github.com/clojure-emacs/cider/issues/3341): Escape clojure-cli args on MS-Windows on non powershell invocations.
 - [#3353](https://github.com/clojure-emacs/cider/issues/3353): Fix regression which caused new connections to prompt for reusing dead REPLs.
 - [#3355](https://github.com/clojure-emacs/cider/pull/3355): Fix `cider-mode` disabling itself after a disconnect when `cider-auto-mode` is set to nil.
+- [#3362](https://github.com/clojure-emacs/cider/issues/3362): Fix `sesman-restart` regression issue.
 
 ### Changes
 

nrepl-client.el

@@ -1191,8 +1191,9 @@ up."
 (declare-function cider--close-connection "cider-connection")
 (defun nrepl-server-sentinel (process event)
   "Handle nREPL server PROCESS EVENT.
-On a fatal EVENT, attempt to close any open client connections, and signal
-an `error' if the nREPL PROCESS exited because it couldn't start up."
+If the nREPL PROCESS failed to initiate and encountered a fatal EVENT
+signal, raise an 'error'.  Additionally, if the EVENT signal is SIGHUP,
+close any existing client connections."
   ;; only interested on fatal signals.
   (when (not (process-live-p process))
     (emacs-bug-46284/when-27.1-windows-nt
@@ -1212,8 +1213,10 @@ an `error' if the nREPL PROCESS exited because it couldn't start up."
                                   (eq (buffer-local-value 'nrepl-server-buffer b)
                                       server-buffer))
                                 (buffer-list))))
-      ;; close any known open client connections
-      (mapc #'cider--close-connection clients)
+
+      ;; see https://github.com/clojure-emacs/cider/pull/3333
+      (when (string-match-p "^hangup" event)
+        (mapc #'cider--close-connection clients))
 
       (if (process-get process :cider--nrepl-server-ready)
           (progn

test/cider-tests.el

@@ -668,6 +668,36 @@
             ;; kill server
             (delete-process (get-buffer-process client-buffer))))))))
 
+(describe "sesman"
+  (it "can restart session"
+    (with-temp-buffer
+      (let* ((server-process (nrepl-start-mock-server-process))
+             (server-buffer (process-buffer server-process)))
+        ;; wait for the connection to be established
+        (nrepl-tests-poll-until (local-variable-p 'nrepl-endpoint server-buffer) 5)
+        (let ((client-buffer (cider-connect-sibling-clj
+                              `(:repl-buffer ,(current-buffer))
+                              server-buffer))
+              (endpoint-bef)
+              (endpoint-aft))
+          (expect (buffer-local-value 'cider-repl-type client-buffer)
+                  :to-equal 'clj)
+
+          (with-current-buffer (cider-current-repl)
+            (setq endpoint-bef nrepl-endpoint))
+
+          (sesman-restart)
+          ;; wait until a new server is brought up, i.e. the port has
+          ;; changed. It will throw if it doesn't.
+          (nrepl-tests-poll-until (when-let ((repl (cider-current-repl)))
+                                    (with-current-buffer repl
+                                      (setq endpoint-aft nrepl-endpoint)
+                                      ;; (message ":endpoints %S %S" endpoint-bef endpoint-aft)
+                                      (not (= (plist-get endpoint-bef :port) (plist-get endpoint-aft :port)))))
+                                  5)
+          ;; kill server
+          (delete-process (get-buffer-process client-buffer)))))))
+
 (provide 'cider-tests)
 
 ;;; cider-tests.el ends here

test/nrepl-server-mock.el

@@ -31,15 +31,17 @@
 (require 'nrepl-client)
 (require 'nrepl-tests-utils "test/utils/nrepl-tests-utils")
 (require 'queue)
+(require 'cl)
 
 (defun nrepl-server-mock-filter (proc output)
   "Handle the nREPL message found in OUTPUT sent by the client
 PROC. Minimal implementation, just enough for fulfilling clients' testing
 requirements."
-  (mock/log! ":mock.filter/output %s :msg %s" proc output)
+  ;; (mock/log! ":mock.filter/output %s :msg %s" proc output)
 
   (condition-case error-details
       (let* ((msg (queue-dequeue (cdr (nrepl-bdecode output))))
+             (_ (mock/log! ":mock.filter/msg :in %S" msg))
              (response (pcase msg
                          (`(dict "op" "clone" "id" ,id)
                           `(dict "id" ,id
@@ -48,10 +50,20 @@ requirements."
 			         "new-session" "a-new-session"))
 
                          (`(dict "op" "describe" "session" ,session "id" ,id)
+                          `(dict "id" ,id "session" ,session "status"
+			         ("done")))
+                         ;; Eval op can include other fields in addition to the
+                         ;; code, we only need the signature and the session and
+                         ;; id fields at the end.
+                         (`(dict "op" "eval" "code" ,_code . ,rest)
+                          (cl-destructuring-bind (_ session _ id) (seq-drop rest (- (seq-length rest) 4))
+                            `(dict "id" ,id "session" ,session "status"
+			           ("done"))))
+                         (`(dict "op" "close" "session" ,session "id" ,id)
                           `(dict "id" ,id "session" ,session "status"
 			         ("done"))))))
 
-        (mock/log! ":mock.filter/msg :in %s :out %s" msg response)
+        (mock/log! ":mock.filter/msg :out %S" response)
         (if (not response)
             (progn
               (mock/log! ":mock.filter/unsupported-msg :in %s :msg %s"