Reusing dead REPL can sometimes lead to REPL being unusable

[OlegTheCat]

Expected behavior

Upon loading, the REPL is ready to use

Actual behavior

REPL becomes broken and is not editable.

Steps to reproduce the problem

1. Start a REPL.
2. Kill the corresponding nrepl buffer.
3. Now we have a REPL with a message *** Closed on ... *** -> in this buffer move a cursor to the begging of the buffer.
4. Start a new REPL and agree to reuse a dead REPL.

Environment & Version information

CIDER version information

;; CIDER 1.2.0 (Nice), nREPL 0.9.0
;; Clojure 1.10.3, Java 1.8.0_322

Lein / Clojure CLI version

Boot 2.8.3

Emacs version

GNU Emacs 27.2 (build 1, aarch64-apple-darwin21.3.0, NS appkit-2113.30 Version 12.2 (Build 21D49)) of 2022-02-09

Operating system

Mac OS 12.6 (M1 processor).

JDK distribution

openjdk version "1.8.0_322"

[benjamin-asdf]

I am killing dead repls instead and never regret it.

(defun mm/cleanup-cider-repls-and-do-not-reuse (&rest _)
  (let ((repls (seq-filter
		(lambda (b)
		  (with-current-buffer
		      b
		    (and (derived-mode-p
			  'cider-repl-mode)
			 (not (process-live-p
			       (get-buffer-process b))))))
		(buffer-list))))
    (mapc #'kill-buffer repls)
    '()))

(advice-add #'cider--choose-reusable-repl-buffer :override #'mm/cleanup-cider-repls-and-do-not-reuse)

[vemv]

I tried to repro this.

Reusing dead repls worked correctly for me.

It's probably because of the misc improvements we've had in this area.

Anyway, as of CIDER master, you can also set the new customization variable cider-reuse-dead-repls to nil.