Re: charset=macintosh

[Simon Josefsson <jas@extundo.com>]

Jesper Harder <harder@myrealbox.com> writes:

> Simon Josefsson <jas@extundo.com> writes:
>
>> For articles without MIME tags, in groups not in g-g-c-a, it would be
>> nice if Gnus could guess better -- like trying to UTF-8 decode it,
>> which typically only fails when data wasn't UTF-8 encoded, and then go
>> on and try other encodings.  Emacs' decoding functions behave a little
>> strange, but onces fixed Gnus should be able to do this.
>
> Currently they're not good enough, IMHO.  Here's an example:
>
> (detect-coding-string (encode-coding-string "dk.test.utf8-æøå" 'utf-8))
>
> => (iso-latin-1 iso-latin-1 raw-text japanese-shift-jis 
>     chinese-big5 no-conversion mule-utf-8)
>
> The correct answer is last in the list.

Doesn't that function use the preference order configured by the user?
For me, who runs emacs in a UTF-8 locale, it returns mule-utf-8 first.
Released emacs versions have incomplete UTF-8 support (see PROBLEMS)
and UTF-8 have a very low priority so any potential bug aren't
triggered unless they, err, really must be triggered.  This is
reasonable, I think.

I've asked on emacs-devel that emacs in CVS (both 21.3 and HEAD),
which supposedly has complete Unicode support, since the PROBLEMS
entry is removed, should prefer UTF-8 more often.  This would be the
best solution IMHO, as Gnus wouldn't have to contain magic charset
prioritizing code.  It also seems like a reasonable solution, assuming
the Unicode stuff actually is working.

The simplest would probably be that people who likes Unicode run emacs
in a UTF-8 locale though, then they would not have any of these
problems.

Your RFC quote was interesting though, I think it suggests that Gnus
should downgrade UTF-8 to ISO-8859-X whenever possible, even if the
user uses a UTF-8 locale, since ISO-8859-X is more widely supported.
That would probably be a contentious decision though: What if a
Japanese user, in a UTF-8 locale, enters text that happens to be
downgradable to ISO-8859-1?  Downgrading in this case is probably
never a good idea.  OTOH if this situation is purely hypothetical, it
doesn't matter if downgrading happens.