C-u <scroll-bar-event> fails.

[Alan Mackenzie]

Emacs "21.1" under X (KDE or Ratpoison window managers)
Emacs 21.2 under Microsoft Windows 2000

Enable the vertical scroll-bar with M-x scroll-bar-mode

Enter C-u (or any other prefix-arg thingy) followed by a mouse-click in
the scroll-bar (in, say, the above-handle area).  I would expect the
prefix arg to be ignored and the window to be scrolled (almost) a
screenful.

Instead, Emacs bleeps, displaying (under X) "vertical-scroll-bar mouse-1"
very briefly in the echo-area.  The window DOESN'T get scrolled.


CONJECTURE:  In the function universal-argument-other-key (in simple.el),
the key-sequence is pushed onto unread-command-events unchanged.

In an analogous situation in isearch-other-meta-char (in isearch.el),
pseudo keypresses such as 'vertical-scroll-bar are removed from the
key-sequence when the latter is pushed back onto unread-command-events.
This works, in that clicking in the scroll bar both exits the search and
scrolls.

It could well be that universal-argument-other-key ought to discard the
likes of 'vertical-scroll-bar too.  (I have tried amending this function
along these lines, but failed to get it to work.)

-- 
Alan Mackenzie (Munich, Germany)
acm@muc.de