WebVTT DOM construction rules and class=""

hi

"HTMLElement nodes created as part of the mapping described above must  
have their namespaceURI set to the HTML namespace, and must have a class  
attribute set to the string obtained by concatenating all the classes that  
apply to the corresponding WebVTT Internal Node Object, each separated  
 from the next by a single U+0020 SPACE character."
http://dev.w3.org/html5/webvtt/#webvtt-cue-text-dom-construction-rules

This says that all elements must have a class attribute, even if it  
doesn't have any classes. That seems undesirable. If no classes apply to  
the WebVTT internal Node Object, the DOM node should have no class  
attribute.

(I'm happy with <v> objects always having a title="" attribute in the DOM,  
since that makes it possible to distinguish <c> and <v>.)

-- 
Simon Pieters
Opera Software