`persp-state-load` Fails to Cleanup Temp Perspective Buffers

[CHANTXU64]

Problem Description

After upgrading to the latest version of perspective.el (20250215.1550), calling persp-state-load creates a temporary perspective with a random name that is not fully cleaned up. This results in:

1. The temporary perspective lingering after restoration.
2. Errors like persp-forget-buffer: Buried buffer [buffer-name] found in window... due to uncleaned buffers.

Regression Note: Rolling back to version 2.19 resolves the issue, confirming a regression in newer versions.

---

Steps to Reproduce

1. Open Emacs and enable persp-mode.
2. Create multiple perspectives with open buffers (e.g., "Work" with buffers a.el, b.el).
3. Save state with M-x persp-state-save.
4. Restart Emacs and load the state with M-x persp-state-load.
5. Observe:
   • A temporary perspective (e.g., 8a3f12) appears.
   • *Messages* shows persp-forget-buffer errors.
   • The "Work" perspective has a.el and b.el
   • The "8a3f12" perspective has b.el
   • The temporary perspective cannot be deleted.

---

Environment

• Emacs Version: 29.4
• OS: macOS 15.3
• Perspective Version: 20250215.1550

[gcv]

I can’t reproduce this. Do you have any more details on the persp-forget-buffer errors?

Edit 1: What kinds of buffers did you have open when you ran persp-state-save? Can you try with only text files open before the save (i.e. .el source files are fine)?

Edit 2: Is it possible that you’re trying to open a state file that has become somehow stale? I’ve run into this bug before, and it had something to do with incompatibilities between the saved perspective state and the installed version of perspective. That said — this shouldn’t have happened with the changes since 2.19.

[CHANTXU64]

I deleted the file saved by persp-state-save and retried, but the result was the same. The results of using the latest version are as follows:

• save file:

#s(persp--state-complete ("/Users/chantxu/.emacs.d/lisp/init-basic.el" "/Users/chantxu/.emacs.d/elpa/perspective-20250215.1550/perspective.el") (#s(persp--state-frame-v2 #s(hash-table size 65 test equal rehash-size 1.5 rehash-threshold 0.8125 data ("main" #s(persp--state-single ("perspective.el" "init-basic.el") (((min-height . 4) (min-width . 10) (min-height-ignore . 4) (min-width-ignore . 4) (min-height-safe . 1) (min-width-safe . 2) (min-pixel-height . 72) (min-pixel-width . 80) (min-pixel-height-ignore . 72) (min-pixel-width-ignore . 32) (min-pixel-height-safe . 18) (min-pixel-width-safe . 16)) leaf (pixel-width . 736) (pixel-height . 810) (total-width . 92) (total-height . 45) (normal-height . 1.0) (normal-width . 1.0) (buffer "init-basic.el" (selected . t) (hscroll . 0) (fringes 8 8 nil nil) (margins nil) (scroll-bars nil 0 t nil 0 t nil) (vscroll . 0) (dedicated) (point . 10062) (start . 8989)) (prev-buffers ("perspective.el" 26705 27038) ("init-basic.el" 8989 10062) ("*scratch*" 1 145)))))) ("main") nil)))

• *Messages*:

progn: Buried buffer init-basic.el found in window #<window 13 on init-basic.el>, but it shouldn’t

• Ibuffer:

 MRL Name                    Size Mode             Filename/Process
 --- ----                    ---- ----             ----------------
[ Default ]
 *%  *Messages*              1154 Messages         
     init-basic.el          25026 ELisp/l          ~/.emacs.d/lisp/init-basic.el
 *   *scratch*                  0 Fundamental      
     perspective.el         99444 ELisp/l          ~/.emacs.d/elpa/perspective-20250215.1550/perspective.el
 *   *helm buffers*            83 Hmm              

     5 buffers             125707                  2 files, no processes

• 4c7683ea temp space - helm buffer:

  • init-basic.el

• main space - helm buffer:

  • init-basic.el
  • *scratch*
  • perspective.el
  • *Messages*

• my config:

(use-package perspective
  :init
  (defvar user-persp-file
    (expand-file-name ".cache/persp-sessions" user-emacs-directory))
  (setq persp-state-default-file user-persp-file)
  (setq persp-suppress-no-prefix-key-warning t)
  :config
  (setq switch-to-prev-buffer-skip
    (lambda (win buff bury-or-kill)
      (not (persp-is-current-buffer buff))))
  (setq persp-sort 'created)
  (setq persp-show-modestring 'header)
  (with-eval-after-load "perspective"
    (add-hook 'after-init-hook
      (lambda ()
        (savehist-mode)
        (if (file-exists-p user-persp-file)
            (persp-state-load user-persp-file)
          (persp-mode 1)))))
  (add-hook 'kill-emacs-hook #'persp-state-save))

[gcv]

Thank you for the detailed report. This is indeed a break introduced by #215, though it only shows up when switch-to-prev-buffer-skip is in play. I'm not sure why. There's some fragile buffer activation and reactivation code in play (written in 2020-2021) that tried (and mostly succeeded!) to prevent buffers from leaking into other perspectives as a result of getting deleted or buried. persp-state-load failed because reactivation had a hard error when it thought a buffer was buried but it was not. It appears that this is actually possible with switch-to-prev-buffer-skip. For now, I commented out the error check.

81d790e

It should fix the persp-state-load problem, but I wonder what else might break. The change should hit MELPA in a couple of hours, please let me know what you find.

@blahgeek: Could you please check if the buffer list behavior you expect still works? Particularly after a Perspective state save and load? Also, please keep an eye for any strangeness in buffer lists after switching perspectives.

[blahgeek]

I tried the newest master version, my expected buffer list behavior still works. I don't use state and load feature though. I will keep an eye on the behavior on future usage. Thanks.

[CHANTXU64]

Thank you. I tested the latest version, created 3 Spaces, and the behavior remained normal after Save and Load. The Helm Buffer List also showed no anomalies after switching Spaces.

[gcv]

Please reopen if anything.