From 7c3593f81724d0c7a2ee2f90797db0e705adc859 Mon Sep 17 00:00:00 2001 From: Tino Calancha Date: Sun, 6 Aug 2017 13:05:16 +0900 Subject: [PATCH] dired-revert: save line numbers instead of positions Positions might change if the length of one dired header line changes; this happen, for instance, if we add new files. Instead, line numbers are invariant under shrinks/enlargements of the file header. https://lists.gnu.org/archive/html/emacs-devel/2017-07/msg01092.html * lisp/dired.el (dired-save-positions): Save the line numbers at point. (dired-restore-positions): Use forward-line to restore the original position (Bug#27968). * test/lisp/dired-tests.el (dired-test-bug27968): Add test. --- lisp/dired.el | 24 +++++++++++++-------- test/lisp/dired-tests.el | 46 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 61 insertions(+), 9 deletions(-) diff --git a/lisp/dired.el b/lisp/dired.el index 24759c6c9bd..d04bd6fe037 100644 --- a/lisp/dired.el +++ b/lisp/dired.el @@ -1444,18 +1444,22 @@ ARG and NOCONFIRM, passed from `revert-buffer', are ignored." The positions have the form (BUFFER-POSITION WINDOW-POSITIONS). BUFFER-POSITION is the point position in the current Dired buffer. -It has the form (BUFFER DIRED-FILENAME BUFFER-POINT). +It has the form (BUFFER DIRED-FILENAME BUFFER-LINE-NUMBER). WINDOW-POSITIONS are current positions in all windows displaying this dired buffer. The window positions have the form (WINDOW -DIRED-FILENAME WINDOW-POINT)." +DIRED-FILENAME WINDOW-LINE-NUMBER). + +We store line numbers instead of point positions because the header +lines might change as well: when this happen the line number doesn't +change; the point does." (list - (list (current-buffer) (dired-get-filename nil t) (point)) + (list (current-buffer) (dired-get-filename nil t) (line-number-at-pos)) (mapcar (lambda (w) - (list w - (with-selected-window w - (dired-get-filename nil t)) - (window-point w))) + (with-selected-window w + (list w + (dired-get-filename nil t) + (line-number-at-pos (window-point w))))) (get-buffer-window-list nil 0 t)))) (defun dired-restore-positions (positions) @@ -1464,7 +1468,8 @@ DIRED-FILENAME WINDOW-POINT)." (buffer (nth 0 buf-file-pos))) (unless (and (nth 1 buf-file-pos) (dired-goto-file (nth 1 buf-file-pos))) - (goto-char (nth 2 buf-file-pos)) + (goto-char (point-min)) + (forward-line (1- (nth 2 buf-file-pos))) (dired-move-to-filename)) (dolist (win-file-pos (nth 1 positions)) ;; Ensure that window still displays the original buffer. @@ -1472,7 +1477,8 @@ DIRED-FILENAME WINDOW-POINT)." (with-selected-window (nth 0 win-file-pos) (unless (and (nth 1 win-file-pos) (dired-goto-file (nth 1 win-file-pos))) - (goto-char (nth 2 win-file-pos)) + (goto-char (point-min)) + (forward-line (1- (nth 2 win-file-pos))) (dired-move-to-filename))))))) (defun dired-remember-marks (beg end) diff --git a/test/lisp/dired-tests.el b/test/lisp/dired-tests.el index b14bbc63609..105a79f0014 100644 --- a/test/lisp/dired-tests.el +++ b/test/lisp/dired-tests.el @@ -308,5 +308,51 @@ (should (eq 2 (current-column)))) (dired-hide-details-mode orig)))) +(ert-deftest dired-test-bug27968 () + "Test for http://debbugs.gnu.org/27968 ." + (let* ((top-dir (make-temp-file "top-dir" t)) + (subdir (expand-file-name "subdir" top-dir)) + (header-len-fn (lambda () + (save-excursion + (goto-char 1) + (forward-line 1) + (- (point-at-eol) (point))))) + orig-len len diff pos line-nb) + (make-directory subdir 'parents) + (unwind-protect + (with-current-buffer (dired-noselect subdir) + (setq orig-len (funcall header-len-fn) + pos (point) + line-nb (line-number-at-pos)) + ;; Bug arises when the header line changes its length; this may + ;; happen if the used space has changed: for instance, with the + ;; creation of additional files. + (make-directory "subdir" t) + (dired-revert) + ;; Change the header line. + (save-excursion + (goto-char 1) + (forward-line 1) + (let ((inhibit-read-only t)) + (delete-region (point) (point-at-eol)) + (insert " test-bug27968"))) + (setq len (funcall header-len-fn) + diff (- len orig-len)) + (should-not (zerop diff)) ; Header length has changed. + ;; If diff > 0, then the point moves back. + ;; If diff < 0, then the point moves forward. + ;; If diff = 0, then the point doesn't move. + ;; Sometimes this point movement causes + ;; line-nb != (line-number-at-pos pos), so that we get + ;; an unexpected file at point if we store buffer points. + ;; Note that the line number before/after revert + ;; doesn't change. + (should (= line-nb + (line-number-at-pos) + (line-number-at-pos (+ pos diff)))) + ;; After revert, the point must be in 'subdir' line. + (should (equal "subdir" (dired-get-filename 'local t)))) + (delete-directory top-dir t)))) + (provide 'dired-tests) ;; dired-tests.el ends here -- 2.39.5