28259 2015-03-22 00:07:33 +0000 [webvtt] Normalization and string identity issues [I18N-ISSUE-425] 2015-11-25 16:06:45 +0000 1 1 1 Unclassified TextTracks CG WebVTT unspecified PC All VERIFIED FIXED widereview P2 normal --- 1 silviapfeiffer1 dave.null addison philipj silviapfeiffer1 singer www-international zcorpan public-texttracks oldest_to_newest 118771 0 silviapfeiffer1 2015-03-22 00:07:33 +0000 Feedback by Addison Phillips from W3C I18N group: http://lists.w3.org/Archives/Public/public-tt/2015Mar/0058.html I18N comment: https://www.w3.org/International/track/issues/425 http://www.w3.org/TR/webvtt1/#webvtt-file-structure Various constructs such as 'cue identifier' are described as being: -- ...any sequence of one or more characters not containing the substring "-->"... -- The document makes understood that this is a sequence of Unicode characters. However, it leaves open the question of whether different Unicode character sequences that represent the same semantic string identifier (see: Charmod [1] and Charmod-Norm [2]) are considered "the same" or not. As currently written, different UTF-8 byte sequences are considered distinct. We would suggest that identifiers that use distinct code point sequences are considered distinct (that is, that you are what we call a "non-normalizing Specification"), which suggests that you include at least a health warning about the dangers of using different character sequences. [1] http://www.w3.org/TR/charmod/ [2] http://www.w3.org/TR/charmod-norm/ Particularly: http://www.w3.org/TR/charmod-norm/#formal-language and http://www.w3.org/TR/charmod-norm/#non-normalizing 119716 1 zcorpan 2015-04-21 08:16:40 +0000 I agree with the comment. It doesn't only apply to cue identifiers (also e.g. voices, classes, cue data, etc.). Maybe we can add a new subsection under Conformance? [[ Unicode normalization This specification does not normalize Unicode text as part of its processing requirements. Example: A cue with the identifier consisting of the character U+212B ANGSTROM SIGN will not match a selector targeting a cue with an ID consisting of the character U+00C5 LATIN CAPITAL LETTER A WITH RING ABOVE. ]] 120810 2 silviapfeiffer1 2015-06-08 12:17:06 +0000 I've prepared https://github.com/w3c/webvtt/pull/195 122290 3 addison 2015-07-27 01:11:32 +0000 The text in the pull has the right intention, but it has a serious flaw in it. It says: -- This specification requires that Unicode text must not be normalized. -- I think you mean to say something more like: -- Implementations of this specification MUST NOT normalize Unicode text during processing. -- 122449 4 philipj 2015-08-04 11:59:15 +0000 https://github.com/w3c/webvtt/pull/195 was merged on June 10, are any further changes needed? 122527 5 silviapfeiffer1 2015-08-09 09:55:24 +0000 I've made the change suggested by Addison, see https://github.com/w3c/webvtt/pull/207 123424 6 silviapfeiffer1 2015-10-01 20:56:12 +0000 Merged https://github.com/whatwg/webvtt/pull/207 124275 7 addison 2015-11-23 18:37:35 +0000 Satisfied by this change.