Package: emacs
Version: 24.3

(Also in current trunk.)

emacs -Q
M-x list-packages RET

Select "ascii-art-to-unicode"

Scroll down the description past the part that says "M-x aa2u RET".
The buffer is completely messed up at this point, showing raw
characters instead of the unicode box that you see if you visit the raw
source file for the package. See attached image.