[webvtt] Issue: Support character escapes in classes (<c.foo&amp; bar>) marked as i18n

r12a has just labeled an issue for https://github.com/w3c/webvtt as 
"i18n":

== Support character escapes in classes (<c.foo&amp;bar>) ==
https://w3c.github.io/webvtt/#webvtt-start-tag-class-state

> WebVTT start tag class state
> Jump to the entry that matches the value of c:
> [...]
> Anything else
> Append c to buffer and jump to the step labeled next.

Should we support character escapes in classes?

```
<c.foo&amp;bar>
```

The class name above is parsed to `foo&amp;bar`, not `foo&bar`. i.e. 
the Selector to match it would be `::cue(.foo\&amp\;bar)` and not 
`::cue(.foo\&bar)`. I think this is a surprising and unnecessary, I 
don't see any problem with supporting escapes here as well as in the 
annotation (which is already supported).

The syntax disallows "&amp;" in classes (so the above is not valid):

https://w3c.github.io/webvtt/#webvtt-cue-span-start-tag

> WebVTT cue span start tag has a tag name and either requires or 
disallows an annotation, and consists of the following components, in 
the order given:

> A U+003C LESS-THAN SIGN character (&lt;).
> The tag name.
> Zero or more occurrences of the following sequence:
> U+002E FULL STOP character (.)
> One or more characters other than U+0009 CHARACTER TABULATION (tab) 
characters, U+000A LINE FEED (LF) characters, U+000D CARRIAGE RETURN 
(CR) characters, U+0020 SPACE characters, U+0026 AMPERSAND characters 
(&amp;), U+003C LESS-THAN SIGN characters (&lt;), U+003E GREATER-THAN 
SIGN characters (>), and U+002E FULL STOP characters (.), representing
 a class that describes the cue span’s significance.

See https://github.com/w3c/webvtt/issues/251

Received on Friday, 21 October 2016 10:12:20 UTC