identifying meta-key bound functions from last-command-char?

[Ken Manheimer]

in a recent emacs build a technique i've been using to deliberately fetch key bindings according to the last-command-char is failing for meta-modified keys.  the problem is that, for meta-modified keys,

  (characterp last-command-char) => nil

this breaks an approach like:

  (key-binding (char-to-string last-command-char))

i need some way to fetch bindings according to last-command-char for a special key handler that i use in overlays and, (for example) in allout.el allout-hotspot-key-handler, a pre-command-hook function.  though probably overly complicated, it has worked through the released emacs 22.  in the recent cvs build (23.0.60), i get an error:

  wrong-type-argument characterp 134217760

(that's for "\M- " meta space, but the same things happens for other meta keys.)  i'm failing to figure out how to translate the meta-modified key to something that i can use for key-binding, and presume i'm missing something obvious.  can someone steer me in the right direction?

(incidentally, i've  been unable to build todays HEAD checkout throughout the day:
  doc-view.el:770:43:Error: Wrong number of arguments: #[nil "\300\207" [(image-mode-window-get (quote page))] 1], 1
)
-- 
ken
http://myriadicity.net