Nick Andryshak <nandryshak@gmail.com> writes:

> See this Stack Exchange question: 
>
> http://emacs.stackexchange.com/questions/7443/mouse-problem-in-org-mode-export-window
>
> The asker is trying to use the mouse wheel to scroll the
> org-export-dispatch window. org-export-dispatch is using the built-in
> function read-char-exclusive, which in turn calls read_filtered_event
> with the parameter error_nonascii set to 0. Unlike read-char, which
> will throw an error upon receiving a mouse event, read-char-exclusive
> just keeps retrying, and eventually the echo area will become full of
> mouse event names.

Yes, I've always wondered what the point of that was.  Test case:

M-: (read-char-exclusive "foo: ")
<mouse-1>

After waiting a bit, the echo area will say: