Error on preview if eww-auto-rename-buffer is t

[zealotrush]

Expected Behavior

1. Set eww-auto-rename-buffer to t.
2. Run markdown-live-preview-mode in a markdown buffer.

After that, a live preview of the markdown buffer should be displayed in a new window.

Actual Behavior

The live preview window does not appear. Following error is echoed.

markdown-live-preview-mode: Wrong type argument: stringp, nil

Steps to Reproduce

1. emacs -Q --load path/to/markdown-mode.el test-case.md
2. Evaluate: (customize-set-variable 'eww-auto-rename-buffer t)
3. In the markdown buffer, M-x, markdown-live-preview-mode

Backtrace

Debugger entered--Lisp error: (wrong-type-argument stringp nil)
  set-buffer(nil)
  (save-current-buffer (set-buffer output-buffer) (setq markdown-live-preview-source-buffer cur-buf) (add-hook 'kill-buffer-hook #'markdown-live-preview-remove-on-kill t t))
  (let ((output-buffer (funcall markdown-live-preview-window-function export-file))) (save-current-buffer (set-buffer output-buffer) (setq markdown-live-preview-source-buffer cur-buf) (add-hook 'kill-buffer-hook #'markdown-live-preview-remove-on-kill t t)) (save-current-buffer (set-buffer cur-buf) (setq markdown-live-preview-buffer output-buffer)))
  (progn (let ((output-buffer (funcall markdown-live-preview-window-function export-file))) (save-current-buffer (set-buffer output-buffer) (setq markdown-live-preview-source-buffer cur-buf) (add-hook 'kill-buffer-hook #'markdown-live-preview-remove-on-kill t t)) (save-current-buffer (set-buffer cur-buf) (setq markdown-live-preview-buffer output-buffer))))
  (unwind-protect (progn (let ((output-buffer (funcall markdown-live-preview-window-function export-file))) (save-current-buffer (set-buffer output-buffer) (setq markdown-live-preview-source-buffer cur-buf) (add-hook 'kill-buffer-hook #'markdown-live-preview-remove-on-kill t t)) (save-current-buffer (set-buffer cur-buf) (setq markdown-live-preview-buffer output-buffer)))) (set-window-configuration wconfig))
  (let ((wconfig (current-window-configuration))) (unwind-protect (progn (let ((output-buffer (funcall markdown-live-preview-window-function export-file))) (save-current-buffer (set-buffer output-buffer) (setq markdown-live-preview-source-buffer cur-buf) (add-hook 'kill-buffer-hook #'markdown-live-preview-remove-on-kill t t)) (save-current-buffer (set-buffer cur-buf) (setq markdown-live-preview-buffer output-buffer)))) (set-window-configuration wconfig)))
  (let* ((markdown-live-preview-currently-exporting t) (cur-buf (current-buffer)) (export-file (markdown-export filename)) (window-data (markdown-live-preview-window-serialize markdown-live-preview-buffer))) (let ((wconfig (current-window-configuration))) (unwind-protect (progn (let ((output-buffer (funcall markdown-live-preview-window-function export-file))) (save-current-buffer (set-buffer output-buffer) (setq markdown-live-preview-source-buffer cur-buf) (add-hook 'kill-buffer-hook #'markdown-live-preview-remove-on-kill t t)) (save-current-buffer (set-buffer cur-buf) (setq markdown-live-preview-buffer output-buffer)))) (set-window-configuration wconfig))) (save-current-buffer (set-buffer cur-buf) (mapc #'markdown-live-preview-window-deserialize window-data) (let ((buf (get-file-buffer export-file))) (if buf (progn (kill-buffer buf)))) (if (and export-file (file-exists-p export-file) (eq markdown-live-preview-delete-export 'delete-on-export)) (progn (delete-file export-file))) markdown-live-preview-buffer))
  (progn (let* ((markdown-live-preview-currently-exporting t) (cur-buf (current-buffer)) (export-file (markdown-export filename)) (window-data (markdown-live-preview-window-serialize markdown-live-preview-buffer))) (let ((wconfig (current-window-configuration))) (unwind-protect (progn (let ((output-buffer ...)) (save-current-buffer (set-buffer output-buffer) (setq markdown-live-preview-source-buffer cur-buf) (add-hook ... ... t t)) (save-current-buffer (set-buffer cur-buf) (setq markdown-live-preview-buffer output-buffer)))) (set-window-configuration wconfig))) (save-current-buffer (set-buffer cur-buf) (mapc #'markdown-live-preview-window-deserialize window-data) (let ((buf (get-file-buffer export-file))) (if buf (progn (kill-buffer buf)))) (if (and export-file (file-exists-p export-file) (eq markdown-live-preview-delete-export 'delete-on-export)) (progn (delete-file export-file))) markdown-live-preview-buffer)))
  (if filename (progn (let* ((markdown-live-preview-currently-exporting t) (cur-buf (current-buffer)) (export-file (markdown-export filename)) (window-data (markdown-live-preview-window-serialize markdown-live-preview-buffer))) (let ((wconfig (current-window-configuration))) (unwind-protect (progn (let (...) (save-current-buffer ... ... ...) (save-current-buffer ... ...))) (set-window-configuration wconfig))) (save-current-buffer (set-buffer cur-buf) (mapc #'markdown-live-preview-window-deserialize window-data) (let ((buf (get-file-buffer export-file))) (if buf (progn (kill-buffer buf)))) (if (and export-file (file-exists-p export-file) (eq markdown-live-preview-delete-export 'delete-on-export)) (progn (delete-file export-file))) markdown-live-preview-buffer))))
  (let ((filename (markdown-live-preview-get-filename))) (if filename (progn (let* ((markdown-live-preview-currently-exporting t) (cur-buf (current-buffer)) (export-file (markdown-export filename)) (window-data (markdown-live-preview-window-serialize markdown-live-preview-buffer))) (let ((wconfig (current-window-configuration))) (unwind-protect (progn (let ... ... ...)) (set-window-configuration wconfig))) (save-current-buffer (set-buffer cur-buf) (mapc #'markdown-live-preview-window-deserialize window-data) (let ((buf ...)) (if buf (progn ...))) (if (and export-file (file-exists-p export-file) (eq markdown-live-preview-delete-export ...)) (progn (delete-file export-file))) markdown-live-preview-buffer)))))
  markdown-live-preview-export()
  (markdown-display-buffer-other-window (markdown-live-preview-export))
  (if (markdown-live-preview-get-filename) (markdown-display-buffer-other-window (markdown-live-preview-export)) (markdown-live-preview-mode -1) (user-error "Buffer %s does not visit a file" (current-buffer)))
  (if markdown-live-preview-mode (if (markdown-live-preview-get-filename) (markdown-display-buffer-other-window (markdown-live-preview-export)) (markdown-live-preview-mode -1) (user-error "Buffer %s does not visit a file" (current-buffer))) (markdown-live-preview-remove))
  (let ((last-message (current-message))) (setq markdown-live-preview-mode (cond ((eq arg 'toggle) (not markdown-live-preview-mode)) ((and (numberp arg) (< arg 1)) nil) (t t))) (if (boundp 'local-minor-modes) (progn (setq local-minor-modes (delq 'markdown-live-preview-mode local-minor-modes)) (if markdown-live-preview-mode (progn (setq local-minor-modes (cons 'markdown-live-preview-mode local-minor-modes)))))) (if markdown-live-preview-mode (if (markdown-live-preview-get-filename) (markdown-display-buffer-other-window (markdown-live-preview-export)) (markdown-live-preview-mode -1) (user-error "Buffer %s does not visit a file" (current-buffer))) (markdown-live-preview-remove)) (run-hooks 'markdown-live-preview-mode-hook (if markdown-live-preview-mode 'markdown-live-preview-mode-on-hook 'markdown-live-preview-mode-off-hook)) (if (called-interactively-p 'any) (progn nil (if (and (current-message) (not (equal last-message (current-message)))) nil (let ((local " in current buffer")) (message "Markdown-Live-Preview mode %sabled%s" (if markdown-live-preview-mode "en" "dis") local))))))
  markdown-live-preview-mode(toggle)
  funcall-interactively(markdown-live-preview-mode toggle)
  command-execute(markdown-live-preview-mode)

Software Versions

• Markdown Mode: markdown-mode, version 2.6-alpha
• Emacs: GNU Emacs 30.0.50 (build 1, aarch64-apple-darwin22.1.0, NS appkit-2299.00 Version 13.0.1 (Build 22A400)) of 2022-12-05
• OS: macOS Ventura

[syohex]

@zealotrush How about #738 ?

BTW t is not valid value of eww-auto-rename-buffer. It accepts 'title, 'url or function. (However the implementation treats all non-nil values as well as 'title except `'url and function)

https://github.com/emacs-mirror/emacs/blob/abbb0faceaedea5369eba68c43e0b19dc861810f/lisp/net/eww.el#L182-L208

[zealotrush]

How about #738 ?

It fixes the error. But the EWW preview buffer does not update automatically. I have to do a manual eww-reload (g) to update the preview.

BTW t is not valid value of eww-auto-rename-buffer. It accepts 'title, 'url or function. (However the implementation treats all non-nil values as well as 'title except `'url and function)

Yes, you are right. Thanks for the reminder!

[syohex]

But the EWW preview buffer does not update automatically. I have to do a manual eww-reload (g) to update the preview.

Ah, if eww-auto-rename-buffer is non-nil, then eww creates new buffer every buffer updating. I'll tackle the issue this weekend.

[syohex]

@zealotrush I've updated eb3f3be. Please try it again.

[zealotrush]

I've updated eb3f3be. Please try it again.

Now it's completely fixed. Thanks!

[syohex]

Thanks for testing.