Advising functions and major-mode?

[Tyler Spivey]

Hello. I am trying to get this (simplified example) to work, and would
like to know what is happening.
(defadvice list-buffers (after test pre act)
(message "%s" major-mode))

Here is what I think should happen, and what is happening.
1. I have set pop-up-windows to nil.
2. When this advice runs, it should print "Buffer-menu-mode". Instead,
it prints the mode of whatever I was in before entering list-buffers.

Is this just a case of the buffer not changing before redisplay or
something like that runs, or have I uncovered a bug?
I've tried adding force-mode-line-update, force-window-update, and
redisplay to the advice before the message, but no luck.

I'm running GNU Emacs 23.0.60.1 (x86_64-unknown-linux-gnu, GTK+ Version
2.12.11) of 2008-09-27 on arch1.