(vc-lookup-triple): Yield nil, not "", if NAME is nil.

Otherwise vc-revert-buffer fails with SCCS.

diff --git a/lisp/vc.el b/lisp/vc.el
index 896e126d17894fdc68b45e6e69eb025c5d12de3a..ed2040a2609b37ff8e4d3070d0f44dbefaf86d9e 100644 (file)
--- a/lisp/vc.el
+++ b/lisp/vc.el
@@ -1038,7 +1038,7 @@ on a buffer attached to the file named in the current Dired buffer line."
 (defun vc-lookup-triple (file name)
   ;; Return the numeric version corresponding to a named snapshot of file
   ;; If name is nil or a version number string it's just passed through
-  (cond ((null name) "")
+  (cond ((null name) name)
        ((let ((firstchar (aref name 0)))
           (and (>= firstchar ?0) (<= firstchar ?9)))
         name)