26885 2014-09-22 17:35:26 +0000 Drop JIS X 212 from ISO-2022-JP 2014-11-04 14:22:33 +0000 1 1 1 Unclassified WHATWG Encoding unspecified All All RESOLVED FIXED P2 normal Unsorted 1 jshin annevk hsivonen jsbell mike pub-w3 smontagu travil VYV03354 www-international sideshowbarker+encodingspec oldest_to_newest 111937 0 jshin 2014-09-22 17:35:26 +0000 EUC-JP in the encoding spec does not support JIS X 212 even though the formal definition of EUC-JP does include it. OTOH, ISO-2022-JP in the encoding spec does support JIS X 212 to my surprise. Is there a reason to support JIS X 212 in ISO-2022-JP? It's not a part of the original ISO-2022-JP (RFC 1468 : https://www.ietf.org/rfc/rfc1468.txt). It's added later in RFC 1554, but I don't think it's widely used. Blink has never supported ISO-2022-JP-2 with JIS X 212. It only supports the original ISO-2022-JP. Supporting JIS X 212 adds ~ 50kB to our build and I'd rather avoid it. 111965 1 annevk 2014-09-22 18:05:32 +0000 Per bug 19939 comment 5 IE probably does not support this either. 111994 2 VYV03354 2014-09-23 00:46:26 +0000 (In reply to Jungshik Shin from comment #0) > EUC-JP in the encoding spec does not support JIS X 212 even though the > formal definition of EUC-JP does include it. Actually the EUC-JP decoder in the encoding spec DOES support JIS X 212. https://encoding.spec.whatwg.org/#euc-jp-decoder > If lead and byte are both in the range 0xA1 to 0xFE, set code point to the index code point for (lead − 0xA1) × 94 + byte − 0xA1 in index jis0208 if the euc-jp jis0212 flag is unset and in index jis0212 otherwise. Did Chrome drop support for decoding JIS X 212 in the EUC-JP decoder? 112064 3 jshin 2014-09-24 05:58:27 +0000 oops. Recently making Blink's Shift-JIS aligned with the encoding spec, I forgot that EUC-JP does support JIS X 212 when converting to Unicode (decoding). Blink's EUC-JP was aligned with the encoding spec and does support JIS X 212 when decoding. 112071 4 annevk 2014-09-24 09:26:16 +0000 It sounds like this is INVALID. 112087 5 jshin 2014-09-24 17:24:15 +0000 Well, the way ICU's ISO-2022-JP-2 implementation is written, the JIS X 212 table is not shared with EUC-JP converter. Unless I change the ICU to share JIS X 212 table, Blink has to live with the build size increase of tens of kBs. In addition, I have to change it unidirectional (decoding only). These are doable, but it's not clear if there's any user-benefits other than being compliant to the current spec. With "ISO-2022-JP" label, Blink (Chrome, Opera) and Safari do not support JIS X 212. They never did (except that I don't know whether the old Opera ever did). With "ISO-2022-JP-1" (or ISO-2022-JP-2) label, Blink and Safari do support JIS X 212 in both directions. Needless to say, virtually nobody uses 'ISO-2022-JP-[12]' in charset declaration. So, it does not count. MSIE does not support JIS X 212 either in ISO-2022-JP. That leaves only Firefox supporting JIS X 212 in ISO-2022-JP at the moment. 112163 6 annevk 2014-09-25 07:55:06 +0000 Jungshik, thanks for explaining further. I take it Blink will stop supporting "ISO-2022-JP-1" and "ISO-2022-JP-2"? Masatoshi, Henri, Simon, would we be okay with dropping 212 support from ISO-2022-JP in Gecko? 112173 7 VYV03354 2014-09-25 14:23:48 +0000 Gecko's ISO-2022-JP decoder has JIS X 0212 support mainly because of Thunderbird. 112176 8 hsivonen 2014-09-25 16:19:45 +0000 (In reply to Jungshik Shin from comment #5) > MSIE does not support JIS X 212 either in ISO-2022-JP. > > That leaves only Firefox supporting JIS X 212 in ISO-2022-JP at the moment. In that case, I think we should remove the ISO-2022-JP-2 aspects of the ISO-2022-JP implementation in Firefox (mozilla-central) and leave it to Thunderbird to support ISO-2022-JP-2 if deemed necessary (should be discoverable via telemetry). (The ISO-2022-JP-2 aspecs involve other weird stuff like a nested GB18030 decoder and a nested EUC-KR decoder.) 112342 9 smontagu 2014-09-28 09:10:40 +0000 The nested decoders in Gecko's ISO-2022-JP-2 implementation, weird as they may be, are there to avoid the same duplication of mapping tables that Jungshik wants to avoid in Blink. Ideally I agree that we want to remove ISO-2022-JP-2 support (not just JIS X 212) from Firefox and from Encoding, though retaining support in Thunderbird, if desired, will be more complicated than other encodings that we've removed. 112344 10 annevk 2014-09-28 10:48:16 +0000 As far as I know removing iso-2022-jp entirely is a nonstarter. It does seem however that Firefox' implementation is sufficiently special it will not be copied by others and that therefore the specification should not follow it. 114485 11 annevk 2014-11-04 14:22:33 +0000 https://github.com/whatwg/encoding/commit/5a2029026a013a1b9fd871f261dfa4059c96d746