Re: Coding system robustness?

[David Kastrup <dak@gnu.org>]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> I'd like to know whether coding systems in general are supposed to be
>> robust, meaning that decoding some random byte string into the coding
>> system and reencoding it is guaranteed to deliver the same byte string
>> again?
>
> AFAIK, (encode-coding-string (decode-coding-string STR 'foo) 'foo)
> should always return STR, otherwise it's a bug.  With the
> introduction of eight-bit-*, this should be true of "all"
> coding-systems in Emacs-21, although IIRC some bugs were found in
> this area and fixed in Emacs-CVS (maybe for utf-8), but my memory is
> fuzzy.

Ok, that means I'll go for it.  I _know_ that XEmacs 21.4 is not
robust in that manner, and maybe I'll provide some customizable
workaround variable you can set to "raw-text" if necessary.  But if
you ask the XEmacs developers' opinion, they'll tell you that you are
mad to use mule-ucs in XEmacs 21.4, anyway.  Not that they could offer
any alternatives right now.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum