bug#33005: 27.0.50; Data loss with Gnus registry

[Eric Abrahamsen <eric@ericabrahamsen.net>]

Michael Heerdegen <michael_heerdegen@web.de> writes:

> Eric Abrahamsen <eric@ericabrahamsen.net> writes:
>
>> People are expected to use `gnus-mock-start' to start it, which does
>> "emacs -Q" internally.
>
> Ah, I remember.
>
>> The only requirement is that the emacs be run
>> from a build directory, and not an installation.
>
> I tried it from my normal Emacs session and got this:
>
> Debugger entered--Lisp error: (buffer-read-only #<buffer .newsrc.eld>)
>   replace-match("/tmp/emacs-gnus-mock-738lXO" t)
>   gnus-mock-start()
>   funcall-interactively(gnus-mock-start)
>   call-interactively(gnus-mock-start record nil)
>   command-execute(gnus-mock-start record)
>
> Is that because it is an installed Emacs, or something else?  Should I
> investigate?

Man, who would have guessed this would be so difficult... I have no idea
why a data file that ships with the package would become read-only.
I suppose I could wrap that in `inhibit-read-only', but if it's read
only for a reason that will only fail later down the line. Can you check
two things, and then I'll give up for now?

1. Put a breakpoint or edebug or otherwise slow the function down, and
after the data directory has been copied to /tmp, make sure that it
belongs to your user and you have the right permissions?

2. Try this version of gnus-mock-start and see if it works:

(defun gnus-mock-start ()
  (interactive)
  (let ((mock-tmp-dir (make-temp-file "emacs-gnus-mock-" t)))
    (condition-case-unless-debug err
	(let ((init-file (expand-file-name "init.el" mock-tmp-dir)))
	  (with-temp-buffer
	    (let ((standard-output (current-buffer))
		  (print-circle nil))
	      (prin1
	       `(setq gnus-home-directory ,mock-tmp-dir
		      init-file-user "mockturtle"
		      sendmail-program
		      ,(expand-file-name gnus-mock-sendmail-program
					 mock-tmp-dir)
		      message-directory ,mock-tmp-dir
		      gnus-startup-file
		      ,(expand-file-name ".newsrc" mock-tmp-dir)
		      gnus-init-file
		      ,(expand-file-name ".gnus.el" mock-tmp-dir)
		      nndraft-directory
		      ,(expand-file-name "drafts/" mock-tmp-dir)
		      gnus-agent-directory
		      ,(expand-file-name "agent/" mock-tmp-dir)
		      gnus-directory
		      ,(expand-file-name "News/" mock-tmp-dir)))
	      (princ "\n\n")
	      ;; Constant that can be checked if we need to know it's a mock
	      ;; session.
	      (prin1 '(defconst gnus-mock-p t))
	      (princ "\n")
	      ;; Constant for use in `gnus-mock-reload', which is defined in
	      ;; the .gnus.el startup file.
 	      (prin1 `(defconst gnus-mock-data-dir ,gnus-mock-data-dir))
	      (when gnus-mock-cleanup-p
		(princ "\n")
		(prin1 `(add-hook 'kill-emacs-hook
				  (lambda () (delete-directory
					      ,mock-tmp-dir t)))))
	      (when gnus-mock-use-images
		(princ "\n")
		(prin1 `(add-to-list 'load-path
				     ,(format "%s/data" mock-tmp-dir))))
	      (write-file init-file)))
	  ;; Put our data and config in place.
	  (copy-directory
	   gnus-mock-data-dir
	   (file-name-as-directory mock-tmp-dir) nil nil t)
	  ;; Git doesn't let us commit empty directories, so create our
	  ;; necessary empty maildir bits, and draft directories.
	  (mapc (lambda (path) (make-directory path t))
		(mapcar (lambda (dir)
			  (format "%s/test/%s" mock-tmp-dir dir))
			'("Welcome/new" "Welcome/tmp" "Welcome/.nnmaildir/marks"
			  "incoming/tmp" "incoming/new" "incoming/cur"
			  "incoming/.nnmaildir/marks" "incoming/.nnmaildir/nov"
			  "mails/tmp" "mails/new" "mails/.nnmaildir/marks")))
	  (make-directory (format "%s/drafts/drafts" mock-tmp-dir) t)
	  (make-directory (format "%s/drafts/queue" mock-tmp-dir))
	  ;; Possibly insert additional config.
	  (when gnus-mock-init-file
	    (with-temp-buffer
	      (insert-file-contents gnus-mock-init-file)
	      (append-to-file
	       (point-min) (point-max) init-file)))
	  (when gnus-mock-gnus-file
	    (with-temp-buffer
	      (insert-file-contents gnus-mock-gnus-file)
	      (append-to-file
	       (point-min) (point-max)
	       (expand-file-name ".gnus.el" mock-tmp-dir))))
	  ;; Possibly add an nnimap server.
	  (when gnus-mock-dovecot-imap-program
	    (with-temp-buffer
	      (insert "\n\n")
	      (prin1
	       `(add-to-list
		 'gnus-secondary-select-methods
		 (quote (nnimap
			 "Mocky"
			 (nnimap-stream shell)
			 (nnimap-shell-program
			  ,(concat
			    gnus-mock-dovecot-imap-program
			    (format " -o mail_location=maildir:%s/imapmail/mail"
				    mock-tmp-dir))))))
	       (current-buffer))
	      (append-to-file
	       (point-min) (point-max)
	       (expand-file-name ".gnus.el" mock-tmp-dir))))
	  ;; There are absolute paths in the .newsrc.eld file, so doctor
	  ;; that file.
	  (let ((inhibit-read-only t))
	   (with-current-buffer (find-file-noselect
				 (expand-file-name ".newsrc.eld" mock-tmp-dir))
	     (while (re-search-forward "REPLACE_ME" (point-max) t)
	       (replace-match mock-tmp-dir t))
	     (when gnus-mock-dovecot-imap-program
	       (goto-char (point-max))
	       (insert "\n\n")
	       (prin1
		'(setq
		  gnus-newsrc-alist
		  (append
		   gnus-newsrc-alist
		   '(("nnimap+Mocky:INBOX" 3 nil ((unexist) (seen (1 . 32)))
		      "nnimap:Mocky" ((modseq . "33") (uidvalidity . "1541087103")
				      (active 1 . 32)
				      (permanent-flags %Answered %Flagged %Deleted
						       %Seen %Draft %*)))
		     ("nnimap+Mocky:emacs-devel" 3 nil ((unexist 0))
		      "nnimap:Mocky" ((modseq . "21") (uidvalidity . "1541087104")
				      (active 0 . 20)
				      (permanent-flags %Answered %Flagged %Deleted
						       %Seen %Draft %*)))
		     ("nnimap+Mocky:\320\237\321\200\320\270\320\262\320\265\321\202\320\274\320\270\321\200"
		      3 nil ((unexist) (seen 1))
		      "nnimap:Mocky" ((modseq . "2") (uidvalidity . "1541087105")
				      (active 1 . 1)
				      (permanent-flags %Answered %Flagged %Deleted
						       %Seen %Draft %*))))))
		(current-buffer)))
	     (basic-save-buffer)))
	  (let ((default-directory
		  (expand-file-name
		   "lisp/gnus"
		   (file-name-as-directory
		    (expand-file-name "../.."
				      gnus-mock-emacs-program)))))
	    (make-process :name "gnus-mock" :buffer nil
			  :command (list gnus-mock-emacs-program
					 "-Q" "--load" init-file)
			  :stderr "*gnus mock errors*")))
      (error (when (and gnus-mock-cleanup-p
			(file-exists-p mock-tmp-dir))
	       (delete-directory mock-tmp-dir t))
	     (signal (car err) (cdr err))))))