Re: [BUG]What does this mean:"Mention that multibyte characters

[Katsumi Yamaoka <yamaoka@jpl.org>]

>>>>> In <m2pt3ryt2b.fsf@yahoo.com.cn>
>>>>>	zrr <beijing_2008_gold@yahoo.com.cn> wrote:

>    I pressed 'E' to expire the artile, but the article still be
>    regarded as not expired.  There is no mark symbol appeared and no
>    highlight on the current line.

>>>>> In <b9yd5zhrl1u.fsf@jpl.org> Katsumi Yamaoka wrote:

> I'll fix it within a couple of days and, if possible,...

I've fixed it in both the Gnus trunk and the v5-10 branch.  It
will help not only Emacs 22 users but also Russian users,
Ukrainian users and much more.

There are two ways that gnus-update-summary-mark-positions
inserts a dummy mark in a multibyte buffer.  Which of them is
used depends on the value of gnus-summary-line-format.

(insert ?\200)
(insert (format "%c" ?\200))

In order to look for the position of a line where it is inserted,
the recent gnus-update-summary-mark-positions searched for the
string:

(mm-string-as-multibyte "\200")

I noticed those three strings will differ by the language
environment and the version of Emacs.  The following form shows
how they are different.

(with-temp-buffer
  (set-buffer-multibyte t)
  (insert ?\200
	  (format "%c" ?\200))
  (list
   (car (split-char (char-after (point-min))))
   (car (split-char (char-after (1+ (point-min)))))
   (car (split-char (string-to-char (string-as-multibyte "\200"))))))

In the Russian language environment, it returns as follows:

;; Emacs 21.3.50
(eight-bit-control mule-unicode-2500-33ff eight-bit-control)
;; Emacs 22.0.0
(iso-8859-1 iso-8859-1 eight-bit)

Even in the English language environment, Emacs 22.0.0 returns:

(iso-8859-1 iso-8859-1 eight-bit)

Those are the cause of the problem which troubled Tang and Derek.

> I'll also summarize how string-(as|make|to)-multibyte works.

I'll try translation of Kenichi Handa's advice next time.

By the way, I'm not sure whether Juri Linkov's similar changes
for the other places don't cause similar problems.