Re: Using iso-8859-15 with Emacs21 & Gnus

[ShengHuo ZHU <zsh@cs.rochester.edu>]

Florian Weimer <fw@deneb.enyo.de> writes:

> ShengHuo ZHU <zsh@cs.rochester.edu> writes:
>
>>> because the standard utf-8.el can deal with ISO-8859-1, but not
>>> ISO-8859-15.
>>
>> That's the problem of utf-8.el.
>
> It completely breaks UTF-8 support for Gnus using Emacs 21.  If you
> reply to a UTF-8 message, chances are good that it contains ISO-8859-1
> characters, and if I understand your code correctly, these characters
> are mapped to ISO-8859-15, so the reply cannot be encoded using UTF-8
> by Emacs.

The point is that if a message contains ISO-8859-15, Gnus converts
ISO-8859-1 to ISO-8859-15.

The cases are that if a message contains

1. no ISO-8859-15 chars, no conversion. Fine for utf-8.el.

2. some inconvertible ISO-8859-15 chars (e.g. euro sign), convert
   ISO-8859-1 to ISO-8859-15. No harm, utf-8.el can't encode it either
   way.  

3. no inconvertible ISO-8859-15 chars, convert ISO-8859-1 to
   ISO-8859-15. It would be better to convert them to ISO-8859-1. But
   this case doesn't happen much. Why users input ISO-8859-15 chars if
   they can do it with ISO-8859-1 chars?

To autodetect the case 3 will lose the efficiency.

ShengHuo