ansi-term seems to break with utf-8 in unicode-2 branch

[Rich Felker]

Here's a screenshot showing what I mean:

http://brightrain.aerifal.cx/~dalias/emacs-wcwidth/emacs-ansi-term-bug.png

The same effect is reproducible by cat'ing the attached text file
(with a screen width of 80 columns). Apparently it's counting bytes
instead of characters. Oddly, it works fine in emacs-21. Here are my
coding system settings (same on both versions):

; Force unix and utf-8
(setq inhibit-eol-conversion t)
(prefer-coding-system 'utf-8)
(setq locale-coding-system 'utf-8)
(set-terminal-coding-system 'utf-8)
(set-keyboard-coding-system 'utf-8)
(set-selection-coding-system 'utf-8)
(setq file-name-coding-system 'utf-8)
(setq coding-system-for-read 'utf-8)
(setq coding-system-for-write 'utf-8)

Testing with emacs -Q isn't very practical since UTF-8 won't be used
then anyway.

Even if this regression is fixed, I suspect there's also an issue with
ansi-term being unaware of character cell width for CJK-wide and
nonspacing characters. It was when trying to test for this bug that I
actually discovered the problem; I don't normally use emacs'
terminals.

Let me know if I can provide more information or if you have trouble
reproducing the problem.

~~Rich

foo.txt
Description: Text document