Re: Please help me test this on MS-Windows

[Óscar Fuentes]

Matt Armstrong <matt@rfc20.org> writes:

> Can somebody with access to an MS-Windows machine help me test the code
> below?
>
> Evaling this in *scratch* suffices.  `unlock-buffer' should signal an
> error.  It does on POSIX-like systems.  I'm 99% sure it will on
> MS-Windows too, but I'd like to confirm, as well as see the specific
> error thrown.  Emacs 27 or 28 is fine.
>
> (let* ((dir (file-name-as-directory
>              (make-temp-file "unlock-test" t)))
>        (name (concat dir "a"))
>        (lockname-as-directory (file-name-as-directory (concat dir ".#a")))
>        (spoiler-name (concat lockname-as-directory "spoiler")))
>   (unwind-protect
>       (progn
>         ;; Create a file named DIR/.#a/spoiler, then attempt to unlock a
>         ;; buffer named DIR/a.  `unlock-buffer' should signal a file-error.
>         (make-directory lockname-as-directory)
>         (with-temp-file spoiler-name
>           (insert "Hello, World!"))
>         (with-temp-buffer
>           (set-buffer-modified-p t)
>           (let ((buffer-file-name name)
>                 (buffer-file-truename name))
>             (unlock-buffer))))
>    (delete-directory dir t nil)))

emacs -Q

GNU Emacs 27.1 (build 1, i686-w64-mingw32) of 2020-11-19

Debugger entered--Lisp error: (file-error "Unlocking file" #("Permission 
denied" 0 17 (charset windows-1252)) 
"c:/Users/Oscar/AppData/Local/Temp/unlock-testxeeb8...")
  unlock-buffer()
  (let ((buffer-file-name name) (buffer-file-truename name)) (unlock-buffer))
  (progn (set-buffer-modified-p t) (let ((buffer-file-name name) 
(buffer-file-truename name)) (unlock-buffer)))
  (unwind-protect (progn (set-buffer-modified-p t) (let ((buffer-file-name 
name) (buffer-file-truename name)) (unlock-buffer))) (and (buffer-name 
temp-buffer) (kill-buffer temp-buffer)))
  (save-current-buffer (set-buffer temp-buffer) (unwind-protect (progn 
(set-buffer-modified-p t) (let ((buffer-file-name name) (buffer-file-truename 
name)) (unlock-buffer))) (and (buffer-name temp-buffer) (kill-buffer 
temp-buffer))))
  (let ((temp-buffer (generate-new-buffer " *temp*"))) (save-current-buffer 
(set-buffer temp-buffer) (unwind-protect (progn (set-buffer-modified-p t) (let 
((buffer-file-name name) (buffer-file-truename name)) (unlock-buffer))) (and 
(buffer-name temp-buffer) (kill-buffer temp-buffer)))))
  (progn (make-directory lockname-as-directory) (let ((temp-file spoiler-name) 
(temp-buffer (generate-new-buffer " *temp file*"))) (unwind-protect (prog1 
(save-current-buffer (set-buffer temp-buffer) (insert "Hello, World!")) 
(save-current-buffer (set-buffer temp-buffer) (write-region nil nil temp-file 
nil 0))) (and (buffer-name temp-buffer) (kill-buffer temp-buffer)))) (let 
((temp-buffer (generate-new-buffer " *temp*"))) (save-current-buffer 
(set-buffer temp-buffer) (unwind-protect (progn (set-buffer-modified-p t) (let 
((buffer-file-name name) (buffer-file-truename name)) (unlock-buffer))) (and 
(buffer-name temp-buffer) (kill-buffer temp-buffer))))))
  (unwind-protect (progn (make-directory lockname-as-directory) (let 
((temp-file spoiler-name) (temp-buffer (generate-new-buffer " *temp file*"))) 
(unwind-protect (prog1 (save-current-buffer (set-buffer temp-buffer) (insert 
"Hello, World!")) (save-current-buffer (set-buffer temp-buffer) (write-region 
nil nil temp-file nil 0))) (and (buffer-name temp-buffer) (kill-buffer 
temp-buffer)))) (let ((temp-buffer (generate-new-buffer " *temp*"))) 
(save-current-buffer (set-buffer temp-buffer) (unwind-protect (progn 
(set-buffer-modified-p t) (let (... ...) (unlock-buffer))) (and (buffer-name 
temp-buffer) (kill-buffer temp-buffer)))))) (delete-directory dir t nil))
  (let* ((dir (file-name-as-directory (make-temp-file "unlock-test" t))) (name 
(concat dir "a")) (lockname-as-directory (file-name-as-directory (concat dir 
".#a"))) (spoiler-name (concat lockname-as-directory "spoiler"))) 
(unwind-protect (progn (make-directory lockname-as-directory) (let ((temp-file 
spoiler-name) (temp-buffer (generate-new-buffer " *temp file*"))) 
(unwind-protect (prog1 (save-current-buffer (set-buffer temp-buffer) (insert 
"Hello, World!")) (save-current-buffer (set-buffer temp-buffer) (write-region 
nil nil temp-file nil 0))) (and (buffer-name temp-buffer) (kill-buffer 
temp-buffer)))) (let ((temp-buffer (generate-new-buffer " *temp*"))) 
(save-current-buffer (set-buffer temp-buffer) (unwind-protect (progn 
(set-buffer-modified-p t) (let ... ...)) (and (buffer-name temp-buffer) 
(kill-buffer temp-buffer)))))) (delete-directory dir t nil)))
  (progn (let* ((dir (file-name-as-directory (make-temp-file "unlock-test" t))) 
(name (concat dir "a")) (lockname-as-directory (file-name-as-directory (concat 
dir ".#a"))) (spoiler-name (concat lockname-as-directory "spoiler"))) 
(unwind-protect (progn (make-directory lockname-as-directory) (let ((temp-file 
spoiler-name) (temp-buffer (generate-new-buffer " *temp file*"))) 
(unwind-protect (prog1 (save-current-buffer ... ...) (save-current-buffer ... 
...)) (and (buffer-name temp-buffer) (kill-buffer temp-buffer)))) (let 
((temp-buffer (generate-new-buffer " *temp*"))) (save-current-buffer 
(set-buffer temp-buffer) (unwind-protect (progn ... ...) (and ... ...))))) 
(delete-directory dir t nil))))
  eval((progn (let* ((dir (file-name-as-directory (make-temp-file "unlock-test" 
t))) (name (concat dir "a")) (lockname-as-directory (file-name-as-directory 
(concat dir ".#a"))) (spoiler-name (concat lockname-as-directory "spoiler"))) 
(unwind-protect (progn (make-directory lockname-as-directory) (let ((temp-file 
spoiler-name) (temp-buffer ...)) (unwind-protect (prog1 ... ...) (and ... 
...))) (let ((temp-buffer ...)) (save-current-buffer (set-buffer temp-buffer) 
(unwind-protect ... ...)))) (delete-directory dir t nil)))) t)
  elisp--eval-last-sexp(nil)
  eval-last-sexp(nil)
  funcall-interactively(eval-last-sexp nil)
  call-interactively(eval-last-sexp nil nil)
  command-execute(eval-last-sexp)