[whatwg] WA1: <style> element content model

[fantasai]

# For styling languages that consist of pure text, user agents must use a
# concatenation of the contents of all the text nodes and CDATA nodes that are
# direct children of the style  element (ignoring any other nodes such as
# comments or elements), in tree order.

This does not give the intended behavior in the following two HTML documents:

  HTML document:

   <style type="text/css">
      .foo { content: "<foo></foo>" }
   </style>

  HTML document:

   <style type="text/css">
   <!--
      .foo { color: blue }
   -->
   </style>

# For XML-based styling languages, user agents must use all the children
# nodes of the style element as the style.

Are HTML documents allowed to use such XML-based styling languages in
the <style> element as well?

~fantasai