diff options
Diffstat (limited to 'lisp')
| -rw-r--r-- | lisp/ChangeLog | 6 | ||||
| -rw-r--r-- | lisp/files.el | 35 |
2 files changed, 36 insertions, 5 deletions
diff --git a/lisp/ChangeLog b/lisp/ChangeLog index 40d8cda4d2f..9d6089d8b1d 100644 --- a/lisp/ChangeLog +++ b/lisp/ChangeLog @@ -1,3 +1,9 @@ +2008-11-27 Karl Fogel <kfogel@red-bean.com> + + * files.el (break-hardlink-on-save): New variable. + (basic-save-buffer-2): Honor new variable break-hardlink-on-save. + (file-precious-flag): Mention it in doc string. + 2008-11-29 Miles Bader <miles@gnu.org> * minibuffer.el (minibuffer-confirm-exit-commands): New variable. diff --git a/lisp/files.el b/lisp/files.el index a071e2bb435..bbda5cf3b46 100644 --- a/lisp/files.el +++ b/lisp/files.el @@ -243,10 +243,29 @@ breaks any hard links between it and other files. This feature is advisory: for example, if the directory in which the file is being saved is not writeable, Emacs may ignore a non-nil value -of `file-precious-flag' and write directly into the file." +of `file-precious-flag' and write directly into the file. + +See also: `break-hardlink-on-save'." :type 'boolean :group 'backup) +(defcustom break-hardlink-on-save nil + "Non-nil means when saving a file that exists under several names +(i.e., has multiple hardlinks), break the hardlink associated with +`buffer-file-name' and write to a new file, so that the other +instances of the file are not affected by the save. + +If `buffer-file-name' refers to a symlink, do not break the symlink. + +Unlike `file-precious-flag', `break-hardlink-on-save' is not advisory. +For example, if the directory in which a file is being saved is not +itself writeable, then error instead of saving in some +hardlink-nonbreaking way. + +See also `backup-by-copying' and `backup-by-copying-when-linked'." + :type 'boolean + :group 'files) + (defcustom version-control nil "Control use of version numbers for backup files. When t, make numeric backup versions unconditionally. @@ -4164,10 +4183,16 @@ Before and after saving the buffer, this function runs (error "Attempt to save to a file which you aren't allowed to write")))))) (or buffer-backed-up (setq setmodes (backup-buffer))) - (let ((dir (file-name-directory buffer-file-name))) - (if (and file-precious-flag - (file-writable-p dir)) - ;; If file is precious, write temp name, then rename it. + (let* ((dir (file-name-directory buffer-file-name)) + (dir-writable (file-writable-p dir))) + (if (or (and file-precious-flag dir-writable) + (and break-hardlink-on-save + (> (file-nlinks buffer-file-name) 1) + (or dir-writable + (error (concat (format + "Directory %s write-protected; " dir) + "cannot break hardlink when saving"))))) + ;; Write temp name, then rename it. ;; This requires write access to the containing dir, ;; which is why we don't try it if we don't have that access. (let ((realname buffer-file-name) |