ISO 8859 encoding detection and interpretation

Yoshiki Hayashi <yoshiki@xemacs.org>

The ISO 8859 coding systems currently allow and generate ISO 2022 charset designation sequences. This is contrary to most users' expectations, and a violation of the ISO 8859 standard. (ISO 2022 designation sequences may be used in the context of an ISO 8859 stream, but strictly speaking that ends the ISO 8859 coded character data element.)

Furthermore, the latin-iso8859-1 coding system is inconsistent, in that it doesn't recognize the ISO 2022 sequences. The various ISO 8859 coding systems should be made consistent.

Status

Although these changes are dear to Hrvoje's heart, and I know Yoshiki supports them, I reluctantly propose that ISO 8859 and 2022 decoder fixes be postponed until the following release cycle. Time is short and it definitely involves user-visible changes in semantics.

Yoshiki Hayashi and Stephen Turnbull are planning to do some work on the ISO 8559-X coding systems in response to Hrvoje's long-running complaints about decoding ISO 2022 escape sequences.

Yoshiki's coding work has not yet been started, although his design concept is quite clear. Steve's design is not yet complete and involves more far-reaching changes to the whole ISO 2022 encoding set.

Open bugs

None.

Other open issues

None.

Discussion

None.

Closed bugs

None.

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