GNU bug report logs -
#29935
26.0.90; copyright-update adds year in middle of buffer
Previous Next
Reported by: Stephen Leake <stephen_leake <at> stephe-leake.org>
Date: Mon, 1 Jan 2018 20:23:02 UTC
Severity: normal
Tags: unreproducible
Found in version 26.0.90
Done: Lars Ingebrigtsen <larsi <at> gnus.org>
Bug is archived. No further changes may be made.
Full log
Message #11 received at 29935 <at> debbugs.gnu.org (full text, mbox):
[Message part 1 (text/plain, inline)]
Here is a recipe for reproducing the bug in emacs-26.0.90 -Q:
Create a directory /tmp/test-copyright
Copy the attached file_1.c-save to that directory
Start emacs -Q
(require 'copyright)
(add-hook 'before-save-hook 'copyright-update)
(find-file "/tmp/test-copyright/file_1.c")
C-x 2
C-x o
C-end
;; insert '// changed line'
C-x b *Messages*
C-x o
C-x b *scratch*
C-x o
M-x save-some-buffers
!
y
C-x b file_1.c
This shows the bug: ', 2018' was inserted on the last line in file_1.c,
not the copyright line.
The fix in the patch given above is "include 'switch-to-buffer' in the
'save-excursion'"; it is not sufficient for this test case, although I
assume it is sufficient in other cases.
A discussion on emacs-devel starting at
https://lists.gnu.org/archive/html/emacs-devel/2018-01/msg00024.html
includes the suggestion to delete 'save-window-excursion'; that does not
fix this test case, and in addition it causes file_1.c to be not
displayed while asking about updating the copyright.
The root cause of the bug is that emacs saves a point for each buffer in
each window; when file_1.c is displayed in the lower window, point is
restored to where it was last displayed in that window; on the last
line.
The attached patch copyright.diff fixes this test case in a minimal way,
by saving the copyright-end point, and restoring it after displaying the
buffer. It also includes 'switch-to-buffer' in the 'save-exursion' to
address the other use cases.
The email thread mentioned above also discusses trying to preserve
frames as well, since switch-to-buffer can pop up a new frame with
certain user settings. This patch does not address that, since it is not
a regression in emacs 26. A more thorough redesign of this function, to
be cleaner and address restoring frames, is left for emacs 27.
--
-- Stephe
[file_1.c-save (application/octet-stream, attachment)]
[copyright.diff (text/x-patch, inline)]
--- a/lisp/emacs-lisp/copyright.el
+++ b/lisp/emacs-lisp/copyright.el
@@ -181,44 +181,54 @@ copyright-update-year
;; This uses the match-data from copyright-find-copyright/end.
(goto-char (match-end 1))
(copyright-find-end)
- (setq copyright-current-year (format-time-string "%Y"))
- (unless (string= (buffer-substring (- (match-end 3) 2) (match-end 3))
- (substring copyright-current-year -2))
- (if (or noquery
- (save-window-excursion
- (switch-to-buffer (current-buffer))
- ;; Fixes some point-moving oddness (bug#2209).
- (save-excursion
- (y-or-n-p (if replace
- (concat "Replace copyright year(s) by "
- copyright-current-year "? ")
- (concat "Add " copyright-current-year
- " to copyright? "))))))
- (if replace
- (replace-match copyright-current-year t t nil 3)
- (let ((size (save-excursion (skip-chars-backward "0-9"))))
- (if (and (eq (% (- (string-to-number copyright-current-year)
- (string-to-number (buffer-substring
- (+ (point) size)
- (point))))
- 100)
- 1)
- (or (eq (char-after (+ (point) size -1)) ?-)
- (eq (char-after (+ (point) size -2)) ?-)))
- ;; This is a range so just replace the end part.
- (delete-char size)
- ;; Insert a comma with the preferred number of spaces.
- (insert
- (save-excursion
- (if (re-search-backward "[0-9]\\( *, *\\)[0-9]"
- (line-beginning-position) t)
- (match-string 1)
- ", ")))
- ;; If people use the '91 '92 '93 scheme, do that as well.
- (if (eq (char-after (+ (point) size -3)) ?')
- (insert ?')))
- ;; Finally insert the new year.
- (insert (substring copyright-current-year size)))))))
+ (let ((copyright-end (point)))
+ (setq copyright-current-year (format-time-string "%Y"))
+ (unless (string= (buffer-substring (- (match-end 3) 2) (match-end 3))
+ (substring copyright-current-year -2))
+ (if (or noquery
+ ;; ‘switch-to-buffer’ can pop up a new frame, or use
+ ;; another window, so preserve the current window
+ ;; config.
+ (save-window-excursion
+ ;; Fixes some point-moving oddness (bug#2209, bug#29935).
+ (save-excursion
+ (switch-to-buffer (current-buffer))
+ ;; Ensure the copyright line is displayed;
+ ;; switch-to-buffer has moved point to where it was
+ ;; when this buffer was last displayed in this
+ ;; window.
+ (goto-char copyright-end)
+ (y-or-n-p (if replace
+ (concat "Replace copyright year(s) by "
+ copyright-current-year "? ")
+ (concat "Add " copyright-current-year
+ " to copyright? "))))))
+ (if replace
+ (replace-match copyright-current-year t t nil 3)
+ (let ((size (save-excursion (skip-chars-backward "0-9"))))
+ (if (and (eq (% (- (string-to-number copyright-current-year)
+ (string-to-number (buffer-substring
+ (+ (point) size)
+ (point))))
+ 100)
+ 1)
+ (or (eq (char-after (+ (point) size -1)) ?-)
+ (eq (char-after (+ (point) size -2)) ?-)))
+ ;; This is a range so just replace the end part.
+ (delete-char size)
+ ;; Insert a comma with the preferred number of spaces.
+ (insert
+ (save-excursion
+ (if (re-search-backward "[0-9]\\( *, *\\)[0-9]"
+ (line-beginning-position) t)
+ (match-string 1)
+ ", ")))
+ ;; If people use the '91 '92 '93 scheme, do that as well.
+ (if (eq (char-after (+ (point) size -3)) ?')
+ (insert ?')))
+ ;; Finally insert the new year.
+ (insert (substring copyright-current-year size))))
+ ))))
;;;###autoload
(defun copyright-update (&optional arg interactivep)
This bug report was last modified 4 years and 311 days ago.
Previous Next
GNU bug tracking system
Copyright (C) 1999 Darren O. Benham,
1997,2003 nCipher Corporation Ltd,
1994-97 Ian Jackson.