Set the fragment scripting mode based on the context document

Closes #12254.

Author: noamr

source

@@ -145705,9 +145705,12 @@ console.assert(container.firstChild instanceof SuperP);
    <li><p>Let <var>document</var> be a <code>Document</code> node whose <span
    data-x="concept-document-type">type</span> is "<code data-x="">html</code>".</p></li>
 
-   <li><p>If <var data-x="concept-frag-parse-context">context</var>'s <span>node document</span> is
-   in <span>quirks mode</span>, then set <var>document</var>'s <span
-   data-x="concept-document-mode">mode</span> to "<code data-x="">quirks</code>".</p></li>
+   <li><p>Let <var>contextDocument</var> be <var data-x="concept-frag-parse-context">context</var>'s
+   <span>node document</span>.</p></li>
+
+   <li><p>If <var>contextDocument</var> is in <span>quirks mode</span>, then set
+   <var>document</var>'s <span data-x="concept-document-mode">mode</span> to "<code
+   data-x="">quirks</code>".</p></li>
 
    <li><p>Otherwise, if <var data-x="concept-frag-parse-context">context</var>'s <span>node
    document</span> is in <span>limited-quirks mode</span>, then set <var>document</var>'s <span
@@ -145719,15 +145722,11 @@ console.assert(container.firstChild instanceof SuperP);
 
    <li><p>Create a new <span>HTML parser</span>, and associate it with <var>document</var>.</p></li>
 
-   <li>
-    <p>If <var>document</var>'s <span
-    data-x="concept-n-script">scripting is enabled</span>, then set the parser's
-    <span>scripting mode</span> to <var>scriptingMode</var>.</p>
+   <li><p>If <var>contextDocument</var>'s <span data-x="concept-n-script">scripting is
+   disabled</span>, then set <var>scriptingMode</var> to <span
+   data-x="scripting-mode-disabled">Disabled</span>.</p></li>
 
-    <p class="XXX">This appears broken, as the document created for fragment parsing does not have a
-    browsing context, which would make it parse <code>noscript</code> as if scripting was disabled.
-    See <a href="https://github.com/whatwg/html/issues/12254">issue #12254</a>.</p>
-   </li>
+   <li><p>Set the parser's <span>scripting mode</span> to <var>scriptingMode</var>.</p></li>
 
    <li>
     <p>Set the state of the <span>HTML parser</span>'s <span>tokenization</span> stage as