bug#5923: 23.1.95; minibuffer-message discards input events

[Drew Adams]

> > > Attached is the code I use for `C-u' in the minibuffer. I 
> > > hope it helps.
> > 
> > It does.
> > 
> > But to tell you the truth the handling of this-command-keys and
> > universal-argument prefix is much too delicate for me to 
> > understand it, so I'm not surprised it doesn't work quite right
> > if you mess with it in any non-trivial way.
> 
> Compare Emacs 22 (and earlier), where there is no bug.
> 
> The code was changed (C to Lisp, at least), and that 
> introduced the regression.

Also, the code I use is _identical_ to the original code in simple.el (Emacs 22
version), except that it also calls `minibuffer-message'. Is that really a
"non-trivial" change?

(And in Emacs 23, `last-command-event' is used instead of `last-command-char' -
that is the only difference I can see from the Emacs 22 code.)