23.0.60; scroll-up gives something between error and message

["Lennart Borgman (gmail)" <lennart.borgman@gmail.com>]

There is something strange with the error handling in scroll-up. When 
calling (scroll-up 1) in an empty buffer execution of the function 
calling it stopped and a message is given. However there is no error 
generated.

To see this start from

    emacs -Q

and evaluate the following function and run it:

(defun test-scroll ()
   (interactive)
   (setq debug-on-error t)
   (let* ((buffer-name "test-scroll")
         (buffer (get-buffer buffer-name)))
     (when buffer (kill-buffer buffer))
     (setq buffer (get-buffer-create buffer-name))
     (switch-to-buffer buffer)
     (message "here 1") (sit-for 2)
     (scroll-up 1)
     (message "here 2") (sit-for 2)
     ))



In GNU Emacs 23.0.60.1 (i386-mingw-nt5.1.2600)
  of 2008-03-21
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (3.4) --no-opt --cflags 
-Ic:/g/include -fno-crossjumping'