Variable: backup-by-copying-when-privileged-mismatch
backup-by-copying-when-privileged-mismatch is a customizable variable
defined in files.el.gz.
Value
200
Documentation
Non-nil means create backups by copying to preserve a privileged owner.
Renaming may still be used (subject to control of other variables)
when it would not result in changing the owner of the file or if the
user id and group id of the file are both greater than the value of
this variable. This is useful when low-numbered uid's and gid's are
used for special system users (such as root) that must maintain
ownership of certain files.
This variable is relevant only if backup-by-copying and
backup-by-copying-when-mismatch are nil.
Probably introduced at or before Emacs version 21.1.
Source Code
;; Defined in /usr/src/emacs/lisp/files.el.gz
(defcustom backup-by-copying-when-privileged-mismatch 200
"Non-nil means create backups by copying to preserve a privileged owner.
Renaming may still be used (subject to control of other variables)
when it would not result in changing the owner of the file or if the
user id and group id of the file are both greater than the value of
this variable. This is useful when low-numbered uid's and gid's are
used for special system users (such as root) that must maintain
ownership of certain files.
This variable is relevant only if `backup-by-copying' and
`backup-by-copying-when-mismatch' are nil."
:type '(choice (const nil) integer)
:group 'backup)