missing font vs. illegal char

[Dan Jacobson]

$ { echo '-*-coding: utf-8-unix;-*-';
 wget -O - http://www.cl.cam.ac.uk/~mgk25/ucs/examples/UTF-8-test.txt;} > h.html
$ emacs h.html

I see the same rectangles for illegal characters that I do for missing
fonts in view-hello-file.

So emacs (21.4.1) doesn't distinguish the two cases. What would be
best is like firefox with the rectangles with the hex digits for
missing fonts... and diamonds with "?" for illegal chars.