* vc-hooks.el (vc-stay-local-p, vc-state, vc-working-revision):

Add an optional argument for the backend, use it instead of
calling vc-backend.
(vc-mode-line): Add an optional argument for the backend.  Pass
the backend to vc-state and vc-working-revision.  Move code for
special handling for vc-state being a buffer to ...

* vc-rcs.el (vc-rcs-find-file-hook):
* vc-sccs.el (vc-sccs-find-file-hook): ... here.  New functions.

* vc-svn.el (vc-svn-state, vc-svn-dir-status, vc-svn-checkout)
(vc-svn-print-log, vc-svn-diff): Pass 'SVN to vc-state,
vc-stay-local-p and vc-mode-line calls.

* vc-cvs.el (vc-cvs-state, vc-cvs-checkout, vc-cvs-print-log)
(vc-cvs-diff, vc-cvs-annotate-command)
(vc-cvs-make-version-backups-p, vc-cvs-stay-local-p)
(vc-cvs-dir-status): Pass 'CVS to vc-state, vc-stay-local-p and
vc-mode-line calls.

* vc.el (vc-deduce-fileset): Use vc-deduce-fileset instead of
direct comparison.
(vc-next-action, vc-transfer-file, vc-rename-file): Also pass the
backend when calling vc-mode-line.
(vc-register): Do not create a closure for calling the vc register
function, call it directly.

1 files changed, 7 insertions, 0 deletions

diff --git a/lisp/vc-rcs.el b/lisp/vc-rcs.el
index 5b35ad0e1cc..0a5ebe42eec 100644
--- a/lisp/vc-rcs.el
+++ b/lisp/vc-rcs.el
@@ -828,6 +828,13 @@ systime, or nil if there is none.  Also, reposition point."
   ;; Just move the master file (using vc-rcs-master-templates).
   (vc-rename-master (vc-name old) new vc-rcs-master-templates))
 
+(defun vc-rcs-find-file-hook ()
+  ;; If the file is locked by some other user, make
+  ;; the buffer read-only.  Like this, even root
+  ;; cannot modify a file that someone else has locked.
+  (stringp (vc-state buffer-file-name 'RCS))
+  (setq buffer-read-only t))
+
 
 ;;;
 ;;; Internal functions