bname needs to be a buffer name, not a filename.

diff --git a/lisp/vc.el b/lisp/vc.el
index 995bcc25692afdf697d6e33936707af16bf9f1a6..9757161b7add78e30131af029205e2cd504d65db 100644 (file)
--- a/lisp/vc.el
+++ b/lisp/vc.el
@@ -1553,7 +1553,7 @@ first backend that could register the file is used."
   (interactive "P")
   (when (and (null fname) (null buffer-file-name)) (error "No visited file"))
 
-  (let ((bname (if fname (get-file-buffer fname) buffer-file-name)))
+  (let ((bname (if fname (get-file-buffer fname) (current-buffer))))
     (unless fname (setq fname buffer-file-name))
     (when (vc-backend fname)
       (if (vc-registered fname)