"Dan" == Dan Mick <dmick@utopia.west.sun.com> writes:
Ben> Basically, we need to deal with the case where a list is
Ben> configured for something like iso-8859-2, but a user sends a
Ben> message in iso-8859-1, or utf-8, etc. In these cases, we
Ben> can't just tack the footer on -- we'll get a garbage message!
Ben> We have to avoid adding a footer if the charsets mismatch; no
Ben> other way about it.
Dan> Why a garbage message? Why not just a (potentially) garbage
Dan> footer?Here's an example.
My Japanese terminal accepts EUC-JP and ISO-2022-JP only. If I displayed a Japanese ISO-2022-JP message with an illegal ISO-8859-1 footer on it, not only would it be a garbage footer, but any further output to the terminal AFTER the footer would be complete garbage, because the illegal 8-bit characters would "shift" my terminal into a special Japanese-only mode.
Basically, illegal footers can be worse than just illegal -- they can render the reader's terminal completely useless, requiring a total restart. This is not acceptable.
Dan> I'd be more concerned about what happened to the message,
Dan> since it's apparently sent in a language that can't be
Dan> understood by its audience.Why? You can set a list's default charset to Japanese, but often get messages in English, Chinese, or Korean. Adding a Japanese footer to these unconditionally without making the whole thing a MIME message with separate parts with their own charsets would break everyone's terminals.
Dan> There's something about the fullness of charset processing
Dan> that I don't grok. I think it has to do with design. Are
Dan> there design notes somewhere?I'm not exactly sure what you mean about fullness, but here's a little explanation from (gasp) Microsoft that covers 7-bit ASCII, 8-bit IBM PC-DOS characters, double-byte character sets like Japanese and Chinese, and Unicode:
http://www.microsoft.com/typography/unicode/cs.htm
Ben
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