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backup-buffer minor reworking of internals

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* lisp/files.el (backup-buffer): Rework to avoid a couple of
unused locals inadvertently introduced in the previous change.
This commit is contained in:
Paul Eggert 2015-05-29 23:17:28 -07:00
parent ab27722721
commit b65be6c5de
1 changed files with 69 additions and 68 deletions
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137
lisp/files.el
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@ -4077,74 +4077,75 @@ on the original file; this means that the caller, after saving
the buffer, should change the extended attributes of the new file
to agree with the old attributes.
BACKUPNAME is the backup file name, which is the old file renamed."
(let (attributes real-file-name backup-info)
(when (and make-backup-files (not backup-inhibited) (not buffer-backed-up)
(setq attributes (file-attributes buffer-file-name))
(memq (aref (elt attributes 8) 0) '(?- ?l)))
;; If specified name is a symbolic link, chase it to the target.
;; This makes backups in the directory where the real file is.
(let* ((real-file-name (file-chase-links buffer-file-name))
(backup-info (find-backup-file-name real-file-name)))
(when backup-info
(let* ((backupname (car backup-info))
(targets (cdr backup-info))
(old-versions
;; If have old versions to maybe delete,
;; ask the user to confirm now, before doing anything.
;; But don't actually delete til later.
(and targets
(booleanp delete-old-versions)
(or delete-old-versions
(y-or-n-p
(format "Delete excess backup versions of %s? "
real-file-name)))
targets))
(modes (file-modes buffer-file-name))
(extended-attributes
(file-extended-attributes buffer-file-name))
(copy-when-priv-mismatch
backup-by-copying-when-privileged-mismatch)
(make-copy
(or file-precious-flag backup-by-copying
;; Don't rename a suid or sgid file.
(and modes (< 0 (logand modes #o6000)))
(not (file-writable-p
(file-name-directory real-file-name)))
(and backup-by-copying-when-linked
(< 1 (file-nlinks real-file-name)))
(and (or backup-by-copying-when-mismatch
(and (integerp copy-when-priv-mismatch)
(let ((attr (file-attributes real-file-name
'integer)))
(<= (nth 2 attr)
copy-when-priv-mismatch))))
(not (file-ownership-preserved-p real-file-name
t)))))
setmodes)
(condition-case ()
(progn
;; Actually make the backup file.
(if make-copy
(backup-buffer-copy real-file-name backupname
modes extended-attributes)
;; rename-file should delete old backup.
(rename-file real-file-name backupname t)
(setq setmodes (list modes extended-attributes
backupname)))
(setq buffer-backed-up t)
;; Now delete the old versions, if desired.
(dolist (old-version old-versions)
(delete-file old-version)))
(file-error nil))
;; If trouble writing the backup, write it in .emacs.d/%backup%.
(when (not buffer-backed-up)
(setq backupname (locate-user-emacs-file "%backup%~"))
(message "Cannot write backup file; backing up in %s" backupname)
(sleep-for 1)
(backup-buffer-copy real-file-name backupname
modes extended-attributes)
(setq buffer-backed-up t))
setmodes))))))
(when (and make-backup-files (not backup-inhibited) (not buffer-backed-up))
(let ((attributes (file-attributes buffer-file-name)))
(when (and attributes (memq (aref (elt attributes 8) 0) '(?- ?l)))
;; If specified name is a symbolic link, chase it to the target.
;; This makes backups in the directory where the real file is.
(let* ((real-file-name (file-chase-links buffer-file-name))
(backup-info (find-backup-file-name real-file-name)))
(when backup-info
(let* ((backupname (car backup-info))
(targets (cdr backup-info))
(old-versions
;; If have old versions to maybe delete,
;; ask the user to confirm now, before doing anything.
;; But don't actually delete til later.
(and targets
(booleanp delete-old-versions)
(or delete-old-versions
(y-or-n-p
(format "Delete excess backup versions of %s? "
real-file-name)))
targets))
(modes (file-modes buffer-file-name))
(extended-attributes
(file-extended-attributes buffer-file-name))
(copy-when-priv-mismatch
backup-by-copying-when-privileged-mismatch)
(make-copy
(or file-precious-flag backup-by-copying
;; Don't rename a suid or sgid file.
(and modes (< 0 (logand modes #o6000)))
(not (file-writable-p
(file-name-directory real-file-name)))
(and backup-by-copying-when-linked
(< 1 (file-nlinks real-file-name)))
(and (or backup-by-copying-when-mismatch
(and (integerp copy-when-priv-mismatch)
(let ((attr (file-attributes
real-file-name
'integer)))
(<= (nth 2 attr)
copy-when-priv-mismatch))))
(not (file-ownership-preserved-p real-file-name
t)))))
setmodes)
(condition-case ()
(progn
;; Actually make the backup file.
(if make-copy
(backup-buffer-copy real-file-name backupname
modes extended-attributes)
;; rename-file should delete old backup.
(rename-file real-file-name backupname t)
(setq setmodes (list modes extended-attributes
backupname)))
(setq buffer-backed-up t)
;; Now delete the old versions, if desired.
(dolist (old-version old-versions)
(delete-file old-version)))
(file-error nil))
;; If trouble writing the backup, write it in .emacs.d/%backup%.
(when (not buffer-backed-up)
(setq backupname (locate-user-emacs-file "%backup%~"))
(message "Cannot write backup file; backing up in %s"
backupname)
(sleep-for 1)
(backup-buffer-copy real-file-name backupname
modes extended-attributes)
(setq buffer-backed-up t))
setmodes)))))))
(defun backup-buffer-copy (from-name to-name modes extended-attributes)
;; Create temp files with strict access rights. It's easy to