[css3-cascade] Try to define the processing model of imported stylesheets.

Author: tabatkins

css3-cascade/Overview.html

@@ -135,6 +135,10 @@ <h2 class="no-num no-toc" id=table-of-contents> Table of contents</h2>
 
    <li><a href="#at-import"><span class=secno>2. </span> Importing style
     sheets: the ‘<code class=css>@import</code>’ rule</a>
+    <ul class=toc>
+     <li><a href="#import-content-type"><span class=secno>2.1. </span>
+      Content-Type of imported stylesheets</a>
+    </ul>
 
    <li><a href="#shorthand"><span class=secno>3. </span> Shorthand
     Properties</a>
@@ -282,10 +286,47 @@ <h2 id=at-import><span class=secno>2. </span> Importing style sheets: the
    Media Queries specification <a href="#MEDIAQ"
    rel=biblioentry>[MEDIAQ]<!--{{!MEDIAQ}}--></a>.
 
+  <h3 id=import-content-type><span class=secno>2.1. </span> Content-Type of
+   imported stylesheets</h3>
+
   <p> In the absence of any media queries, the import is unconditional.
    Specifying ‘<a href="#all"><code class=css>all</code></a>’ for the
    medium has the same effect.
 
+  <p> The processing of imported stylesheets depends on the actual type of
+   the linked resource. If the resource does not have <a
+   href="http://www.whatwg.org/specs/web-apps/current-work/multipage/fetching-resources.html#content-type">Content-Type
+   metadata</a>, or the host document is in <a
+   href="http://www.whatwg.org/specs/web-apps/current-work/multipage/infrastructure.html#quirks-mode">quirks
+   mode</a> and has the <a
+   href="http://www.whatwg.org/specs/web-apps/current-work/multipage/origin-0.html#same-origin">
+   sameorigin</a> as the imported stylesheet, the type of the linked resource
+   is <code>text/css</code>. Otherwise, the type is determined from its <a
+   href="http://www.whatwg.org/specs/web-apps/current-work/multipage/fetching-resources.html#content-type">Content-Type
+   metadata</a>.
+
+  <p> If the linked resource's type is <code>text/css</code>, it must be
+   interpreted as a CSS stylesheet. Otherwise, if the resource's type denotes
+   a type of stylesheet that the user agent understands, it must be
+   interpreted as defined by that type. Otherwise, the resource must not be
+   interpreted as a stylesheet. The stylesheet keyword may be used with link
+   elements. This keyword creates an external resource link that contributes
+   to the styling processing model. The specified resource is a resource that
+   describes how to present the document. Exactly how the resource is to be
+   processed depends on the actual type of the resource. If the alternate
+   keyword is also specified on the link element, then the link is an
+   alternative stylesheet; in this case, the title attribute must be
+   specified on the link element, with a non-empty value. The default type
+   for resources given by the stylesheet keyword is text/css. The appropriate
+   time to obtain the resource is when the external resource link is created
+   or when its element is inserted into a document, whichever happens last.
+   If the resource is an alternative stylesheet then the user agent may defer
+   obtaining the resource until it is part of the preferred style sheet set.
+   [CSSOM] Quirk: If the document has been set to quirks mode, has the same
+   origin as the URL of the external resource, and the Content-Type metadata
+   of the external resource is not a supported style sheet type, the user
+   agent must instead assume it to be text/css.
+
   <h2 id=shorthand><span class=secno>3. </span> Shorthand Properties</h2>
 
   <p> Some properties are <dfn id=shorthand-properties>shorthand

css3-cascade/Overview.src.html

@@ -123,11 +123,43 @@ <h2 id="at-import">
 		The full syntax of the expressions after the URL 
 		is defined by the Media Queries specification [[!MEDIAQ]].
 
+<h3 id='import-content-type'>
+Content-Type of imported stylesheets</h3>
+
 	<p>
 		In the absence of any media queries, 
 		the import is unconditional. 
 		Specifying ''all'' for the medium has the same effect.
 
+	<p>
+		The processing of imported stylesheets depends on the actual type of the linked resource.
+		If the resource does not have <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/fetching-resources.html#content-type">Content-Type metadata</a>,
+		or the host document is in <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/infrastructure.html#quirks-mode">quirks mode</a> 
+		and has the <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/origin-0.html#same-origin"> sameorigin</a> as the imported stylesheet,
+		the type of the linked resource is <code>text/css</code>.
+		Otherwise, the type is determined from its <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/fetching-resources.html#content-type">Content-Type metadata</a>.
+
+	<p>
+		If the linked resource's type is <code>text/css</code>,
+		it must be interpreted as a CSS stylesheet.
+		Otherwise, if the resource's type denotes a type of stylesheet that the user agent understands,
+		it must be interpreted as defined by that type.
+		Otherwise, the resource must not be interpreted as a stylesheet.
+
+
+
+The stylesheet keyword may be used with link elements. This keyword creates an external resource link that contributes to the styling processing model.
+
+The specified resource is a resource that describes how to present the document. Exactly how the resource is to be processed depends on the actual type of the resource.
+
+If the alternate keyword is also specified on the link element, then the link is an alternative stylesheet; in this case, the title attribute must be specified on the link element, with a non-empty value.
+
+The default type for resources given by the stylesheet keyword is text/css.
+
+The appropriate time to obtain the resource is when the external resource link is created or when its element is inserted into a document, whichever happens last. If the resource is an alternative stylesheet then the user agent may defer obtaining the resource until it is part of the preferred style sheet set. [CSSOM]
+
+Quirk: If the document has been set to quirks mode, has the same origin as the URL of the external resource, and the Content-Type metadata of the external resource is not a supported style sheet type, the user agent must instead assume it to be text/css.
+
 
 <h2 id='shorthand'>
 Shorthand Properties</h2>