Add disabled concept

source

@@ -54596,23 +54596,26 @@ interface <dfn interface>HTMLOptionElement</dfn> : <span>HTMLElement</span> {
   <var>option</var>:</p>
 
   <ol>
+   <li><p>Let <var>select</var> be <var>option</var>'s <span><code>option</code> element nearest
+   ancestor <code>select</code></span>.</p></li>
+
    <li>
     <p>If all of the following conditions are true:</p>
 
     <ul>
-     <li><p><var>option</var> has a non-null <span><code>option</code> element nearest ancestor
-     <code>select</code></span>;</p></li>
+     <li><p><var>select</var> is not null;</p></li>
 
-     <li><p><var>option</var>'s <span><code>option</code> element nearest ancestor
-     <code>select</code></span> does not have the <code
-     data-x="attr-select-multiple">multiple</code> attribute;</p></li>
+     <li><p><var>select</var> does not have the <code data-x="attr-select-multiple">multiple</code>
+     attribute;</p></li>
 
      <li><p><var>option</var>'s <span data-x="concept-option-selectedness">selectedness</span>
-     is true,</p></li>
+     is true;</p></li>
+
+     <li><p><var>select</var>'s <span>descendant <code>selectedcontent</code> elements</span> is not
+     empty;</p></li>
 
-     <li><p><var>option</var>'s <span><code>option</code> element nearest ancestor
-     <code>select</code></span>'s <span>descendant <code>selectedcontent</code> elements</span> is
-     not empty,</p></li>
+     <li><p>The first element in <var>select</var>'s <span>descendant <code>selectedcontent</code>
+     elements</span> is not <span data-x="selectedcontent-disabled">disabled</span>,</p></li>
     </ul>
 
     <p>then run <span>clone an option into a selectedcontent</span> given <var>option</var> and the
@@ -56321,6 +56324,10 @@ interface <dfn interface>HTMLSelectedContentElement</dfn> : <span>HTMLElement</s
   the <code>selectedcontent</code> is a <span>descendant</span> of the <code>select</code>'s first
   child <code>button</code>.</p>
 
+  <p>Every <code>selectedcontent</code> element has a <dfn
+  data-x="selectedcontent-disabled">disabled</dfn> state, which is a boolean, initially set to
+  false.</p>
+
   <p>To <dfn>clone an option into a selectedcontent</dfn>, given an <code>option</code> element
   <var>option</var> and a <code>selectedcontent</code> element <var>selectedcontent</var>:</p>
 
@@ -56367,15 +56374,29 @@ interface <dfn interface>HTMLSelectedContentElement</dfn> : <span>HTMLElement</s
 
    <li><p>Let <var>ancestor</var> be <var>selectedcontent</var>'s <span>parent</span>.</p></li>
 
+   <li><p>Set <var>selectedcontent</var>'s <span data-x="selectedcontent-disabled">disabled</span>
+   state to false.</p></li>
+
    <li>
-    <p><span>While</span> <var>nearestSelectAncestor</var> is null and <var>ancestor</var> is not
-    null:</p>
+    <p>For each <var>ancestor</var> of <var>selectedcontent</var>'s <span
+    data-x="ancestor">ancestors</span> in reverse <span>tree order</span>:</p>
 
     <ol>
-     <li><p>If <var>ancestor</var> is a <code>select</code> element, then set
-     <var>nearestSelectAncestor</var> to <var>ancestor</var>.</p></li>
+     <li>
+      <p>If <var>ancestor</var> is a <code>select</code> element, then:</p>
+
+      <ol>
+       <li><p>If <var>nearestAncestorSelect</var> is null, then set <var>nearestAncestorSelect</var>
+       to <var>select</var>.</p></li>
+
+       <li><p>Otherwise, set <var>selectedcontent</var>'s <span
+       data-x="selectedcontent-disabled">disabled</span> state to true.</p></li>
+      </ol>
+     </li>
 
-     <li><p>Set <var>ancestor</var> to <var>ancestor</var>'s <span>parent</span>.</p></li>
+     <li><p>If <var>ancestor</var> is an <code>option</code> element or a
+     <code>selectedcontent</code> element, then set <var>selectedcontent</var>'s <span
+     data-x="selectedcontent-disabled">disabled</span> state to true.</p></li>
     </ol>
    </li>
 
@@ -56386,7 +56407,8 @@ interface <dfn interface>HTMLSelectedContentElement</dfn> : <span>HTMLElement</s
    elements</span>.</p></li>
 
    <li>
-    <p>If <var>selectedcontent</var> is the first item in <var>nearestAncestorSelect</var>'s
+    <p>If <var>selectedcontent</var> is not <span data-x="selectedcontent-disabled">disabled</span>
+    and <var>selectedcontent</var> is the first item in <var>nearestAncestorSelect</var>'s
     <span>descendant <code>selectedcontent</code> elements</span>, then:</p>
 
     <ol>