bug#1106: last-coding-system-used may be nil in load-with-code-conversion

[Chong Yidong]

> Putting the following in one's .emacs causes Emacs to crash on
> startup:
> 
> (setq file-coding-system-alist nil)
> (load "/dev/null")
>
> This happens because mule.el wrongly assumes that
> last-coding-system-used cannot be null on line 84.
>
> In GNU Emacs 22.2.1 (i486-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
>  of 2008-09-05 on vernadsky, modified by Ubuntu

I can't reproduce the crash with Emacs 22.2.  Maybe it's due to a Debian
change?

Could you check if the crash happens with a vanille Emacs 22.2
downloaded from ftp://ftp.gnu.org/gnu/emacs/ ?

Also, does the crash happen with Emacs CVS (or the Debian emacs-snapshot
package)?

Thanks.