Re: vc mode enhancement proposal

[Kevin Rodgers]

Neal Becker wrote:
> If I edit a version-controlled, hard-linked file, no backup is made (cause
> it's version-controlled), and the results is the editing does not break
> the hard link.
>
> Sometimes that's what I want.  Other times it's not.
>
> I don't know how to get emacs to break the hard link.

Does this do what you want:

(defun vc-backup-by-copying-when-linked ()
  "Set `vc-make-backup-files' according to the visited file.
If the visited file has multiple names, set the buffer-local value of
`vc-make-backup-files' to t.  See `backup-by-copying-when-linked'."
  (let ((real-file-name (file-chase-links buffer-file-name)))
    (when (> (file-nlinks real-file-name) 1)
      (set (make-local-variable 'vc-make-backup-files) t))))

(add-hook 'find-file-hook 'vc-backup-by-copying-when-linked)

> What I think we need is to add vc-make-backups-when-linked.

--
Kevin Rodgers
Denver, Colorado, USA