vc-rcs problem

[Markus Rost]

If an RCS registered file is not present, you can't check it out with
find-file anymore.  This is for the current CVS version.  The problem
is not present in 21.3.

Perform the following steps:

C-x C-f "x.el"  (find-file)

==> (New file)

C-x C-v C-v     (vc-next-action)

==> Buffer x.el modified; save it? (y or n) 

This question is somewhat strange, because I did not modify the buffer
by hand, but never mind.  Give answer "y".

==> Create RCS subdirectory? (yes or no) 

Give answer: "no" (it probably doesn't matter for the problem what you
answer here; maybe you are not prompted anyway.)

==> Registering /home/rost/x.el... done

C-x k RET (kill-buffer "x.el")

M-x delete-file x.el

C-x C-f "x.el"  (find-file)

You get an error:

==> vc-rcs-state-heuristic: Wrong type argument: stringp, nil

Here is the backtrace.

===Buffer *Backtrace*=======================================
Debugger entered--Lisp error: (wrong-type-argument stringp nil)
  string-match(".r-..-..-." nil)
  vc-rcs-state-heuristic("/home/rost/x.el")
  apply(vc-rcs-state-heuristic "/home/rost/x.el")
  vc-call-backend(RCS state-heuristic "/home/rost/x.el")
  vc-state("/home/rost/x.el")
  vc-default-mode-line-string(RCS "/home/rost/x.el")
  apply(vc-default-mode-line-string RCS "/home/rost/x.el")
  vc-call-backend(RCS mode-line-string "/home/rost/x.el")
  vc-mode-line("/home/rost/x.el")
  vc-find-file-hook()
  run-hooks(find-file-hook)
  after-find-file(t t)
  find-file-noselect-1(#<buffer x.el> "~/x.el" nil nil "~/x.el" nil)
  find-file-noselect("~/x.el" nil nil t)
  find-file("~/x.el" t)
  call-interactively(find-file)

============================================================