X-Git-Url: http://git.chise.org/gitweb/?p=chise%2Fxemacs-chise.git.1;a=blobdiff_plain;f=lisp%2Ffiles.el;h=4d9562d7e1eace095289eec24bcad52e7b640f92;hp=8116b071106d1e1b54e1c5c9c942b06d60080f70;hb=dbf2768f7b146e97e37a27316f70bb313f1acf15;hpb=042cabb13b0419d8aa5cfac9e087d78730d1dbc7 diff --git a/lisp/files.el b/lisp/files.el index 8116b07..4d9562d 100644 --- a/lisp/files.el +++ b/lisp/files.el @@ -376,7 +376,8 @@ and ignores this variable." (let ((name (copy-sequence filename)) (start 0)) ;; leave ':' if part of drive specifier - (if (eq (aref name 1) ?:) + (if (and (> (length name) 1) + (eq (aref name 1) ?:)) (setq start 2)) ;; destructively replace invalid filename characters with ! (while (string-match "[?*:<>|\"\000-\037]" name start) @@ -2641,7 +2642,9 @@ which are the arguments that `revert-buffer' received.") (defvar revert-buffer-insert-file-contents-function nil "Function to use to insert contents when reverting this buffer. Gets two args, first the nominal file name to use, -and second, t if reading the auto-save file.") +and second, t if reading the auto-save file. +If the current buffer contents are to be discarded, the function must do +so itself.") (defvar before-revert-hook nil "Normal hook for `revert-buffer' to run before reverting. @@ -2666,10 +2669,10 @@ This undoes all changes since the file was visited or saved. With a prefix argument, offer to revert from latest auto-save file, if that is more recent than the visited file. -This command also works for special buffers that contain text which -doesn't come from a file, but reflects some other data base instead: -for example, Dired buffers and buffer-list buffers. In these cases, -it reconstructs the buffer contents from the appropriate data base. +This command also refreshes certain special buffers that contain text +which doesn't come from a file, but reflects some other data base +instead: for example, Dired buffers and buffer-list buffers. This is +implemented by having the modes set `revert-buffer-function'. When called from Lisp, the first argument is IGNORE-AUTO; only offer to revert from the auto-save file when this is nil. Note that the @@ -2681,13 +2684,17 @@ Optional second argument NOCONFIRM means don't ask for confirmation at all. Optional third argument PRESERVE-MODES non-nil means don't alter -the files modes. Normally we reinitialize them using `normal-mode'. +the buffer's modes. Otherwise, reinitialize them using `normal-mode'. If the value of `revert-buffer-function' is non-nil, it is called to do all the work for this command. Otherwise, the hooks `before-revert-hook' and `after-revert-hook' are run at the beginning and the end, and if `revert-buffer-insert-file-contents-function' is -non-nil, it is called instead of rereading visited file contents." +non-nil, it is called instead of rereading visited file contents. + +If the buffer-modified flag is nil, and we are not reverting from an +auto-save file, then compare the contents of the buffer and the file. +Revert only if they differ." ;; I admit it's odd to reverse the sense of the prefix argument, but ;; there is a lot of code out there which assumes that the first @@ -2699,6 +2706,8 @@ non-nil, it is called instead of rereading visited file contents." (if revert-buffer-function (funcall revert-buffer-function ignore-auto noconfirm) (let* ((opoint (point)) + (newbuf nil) + (delay-prompt nil) (auto-save-p (and (not ignore-auto) (recent-auto-save-p) buffer-auto-save-file-name @@ -2716,58 +2725,111 @@ non-nil, it is called instead of rereading visited file contents." (dolist (rx revert-without-query found) (when (string-match rx file-name) (setq found t))))) + ;; If we will call revert-buffer-internal, delay prompting + (and (not auto-save-p) + (not (buffer-modified-p)) + (setq delay-prompt t)) (yes-or-no-p (format "Revert buffer from file %s? " file-name))) (run-hooks 'before-revert-hook) - ;; If file was backed up but has changed since, - ;; we should make another backup. - (and (not auto-save-p) - (not (verify-visited-file-modtime (current-buffer))) - (setq buffer-backed-up nil)) - ;; Get rid of all undo records for this buffer. - (or (eq buffer-undo-list t) - (setq buffer-undo-list nil)) - ;; Effectively copy the after-revert-hook status, - ;; since after-find-file will clobber it. - (let ((global-hook (default-value 'after-revert-hook)) - (local-hook-p (local-variable-p 'after-revert-hook - (current-buffer))) - (local-hook (and (local-variable-p 'after-revert-hook - (current-buffer)) - after-revert-hook))) - (let (buffer-read-only - ;; Don't make undo records for the reversion. - (buffer-undo-list t)) - (if revert-buffer-insert-file-contents-function - (funcall revert-buffer-insert-file-contents-function - file-name auto-save-p) - (if (not (file-exists-p file-name)) - (error "File %s no longer exists!" file-name)) - ;; Bind buffer-file-name to nil - ;; so that we don't try to lock the file. - (let ((buffer-file-name nil)) - (or auto-save-p - (unlock-buffer))) - (widen) - (insert-file-contents file-name (not auto-save-p) - nil nil t))) - (goto-char (min opoint (point-max))) - ;; Recompute the truename in case changes in symlinks - ;; have changed the truename. - ;XEmacs: already done by insert-file-contents - ;;(setq buffer-file-truename - ;;(abbreviate-file-name (file-truename buffer-file-name))) - (after-find-file nil nil t t preserve-modes) - ;; Run after-revert-hook as it was before we reverted. - (setq-default revert-buffer-internal-hook global-hook) - (if local-hook-p - (progn - (make-local-variable 'revert-buffer-internal-hook) - (setq revert-buffer-internal-hook local-hook)) - (kill-local-variable 'revert-buffer-internal-hook)) - (run-hooks 'revert-buffer-internal-hook)) + (cond ((or auto-save-p + (buffer-modified-p) + ;; Do we need to do expensive reversion? Compare ... + (and (setq newbuf (revert-buffer-internal + file-name)) + ;; ... and if different, prompt + (or noconfirm + (and delay-prompt + (yes-or-no-p + (format "Revert buffer from file %s? " + file-name)))))) + ;; If file was backed up but has changed since, + ;; we should make another backup. + (and (not auto-save-p) + (not (verify-visited-file-modtime (current-buffer))) + (setq buffer-backed-up nil)) + ;; Get rid of all undo records for this buffer. + (or (eq buffer-undo-list t) + (setq buffer-undo-list nil)) + ;; Effectively copy the after-revert-hook status, + ;; since after-find-file will clobber it. + (let ((global-hook (default-value 'after-revert-hook)) + (local-hook-p (local-variable-p 'after-revert-hook + (current-buffer))) + (local-hook (and (local-variable-p 'after-revert-hook + (current-buffer)) + after-revert-hook))) + (let (buffer-read-only + ;; Don't make undo records for the reversion. + (buffer-undo-list t)) + (if revert-buffer-insert-file-contents-function + (funcall revert-buffer-insert-file-contents-function + file-name auto-save-p) + (if (not (file-exists-p file-name)) + (error "File %s no longer exists!" file-name)) + ;; Bind buffer-file-name to nil + ;; so that we don't try to lock the file. + (let ((buffer-file-name nil)) + (or auto-save-p + (unlock-buffer))) + (widen) + (insert-file-contents file-name (not auto-save-p) + nil nil t))) + (goto-char (min opoint (point-max))) + ;; Recompute the truename in case changes in symlinks + ;; have changed the truename. + ;;XEmacs: already done by insert-file-contents + ;;(setq buffer-file-truename + ;;(abbreviate-file-name (file-truename buffer-file-name))) + (after-find-file nil nil t t preserve-modes) + ;; Run after-revert-hook as it was before we reverted. + (setq-default revert-buffer-internal-hook global-hook) + (if local-hook-p + (progn + (make-local-variable 'revert-buffer-internal-hook) + (setq revert-buffer-internal-hook local-hook)) + (kill-local-variable 'revert-buffer-internal-hook)) + (run-hooks 'revert-buffer-internal-hook))) + ((null newbuf) + ;; The resultant buffer is identical, alter + ;; modtime, update mods and exit + (set-visited-file-modtime) + (after-find-file nil nil t t t)) + (t t)) t))))) +;; #### something like `revert-buffer-compare-with-file' is a better name +;; #### why is the argument optional? +(defun revert-buffer-internal (&optional file-name) + "Read contents of FILE-NAME into a buffer, and compare to current buffer. +Return nil if identical, and the new buffer if different." + + (let* ((newbuf (get-buffer-create " *revert*")) + bmin bmax) + (save-excursion + (set-buffer newbuf) + (let (buffer-read-only + (buffer-undo-list t) + after-change-function + after-change-functions + before-change-function + before-change-functions) + (if revert-buffer-insert-file-contents-function + (funcall revert-buffer-insert-file-contents-function + file-name nil) + (if (not (file-exists-p file-name)) + (error "File %s no longer exists!" file-name)) + (widen) + (insert-file-contents file-name nil nil nil t) + (setq bmin (point-min) + bmax (point-max))))) + (if (not (and (eq bmin (point-min)) + (eq bmax (point-max)) + (eq (compare-buffer-substrings + newbuf bmin bmax (current-buffer) bmin bmax) 0))) + newbuf + (and (kill-buffer newbuf) nil)))) + (defun recover-file (file) "Visit file FILE, but get contents from its last auto-save file." ;; Actually putting the file name in the minibuffer should be used