emacs hangs on invalid unicode character

[Axel Liljencrantz <axel@liljencrantz.se>]

I've encountered a bug in emacs, that I wanted to share. I could not
find any mention of this issue in the mail archives. 

If running emacs in terminal (non-X) mode, pressing Meta and a multibyte
UFT character such as 'å' (the swedish character looking like an 'a'
with a circle above it), emacs hangs and takes up 100% CPU activity. 

AFAIK this only happens in UTF-8 locales. To reproduce this problem:

Set your OS to use a a Swedish keyboard layout.

Issue this in bash:

export LANG=en_US.UTF-8
emacs -nw

Now hold Meta and the key to the right of 'p' on your keyboard. 

emacs should now be hanged.


The sequence generated på pressing 'å' is -61 -91. The sequence
generated by Meta-å is 27, -61, -91. I think this bug works for any
multi-byte character.

I've encountered this bug on many different platforms, including this
one:

Version: emacs version 21.3.1 (shipped with Fedora Core 3)
Platform: i386
OS: Fedora Core 3
Locale: en_US.UTF-8


-- 
Axel Liljencrantz <axel@liljencrantz.se>