<html>
    <head>
      <base href="https://bugs.webkit.org/" />
    </head>
    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - adoptNode() changes css class to lowercase for document loaded with XHR responseType = &quot;document&quot;"
   href="https://bugs.webkit.org/show_bug.cgi?id=159555">159555</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>adoptNode() changes css class to lowercase for document loaded with XHR responseType = &quot;document&quot;
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>WebKit
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>Safari 9
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>Unspecified
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>Unspecified
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>Normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>P2
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>HTML DOM
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>webkit-unassigned&#64;lists.webkit.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>theblueslate&#64;gmail.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>cdumez&#64;apple.com
          </td>
        </tr></table>
      <p>
        <div>
        <pre>For a full demonstration, see <a href="https://jsfiddle.net/theblueslate/wxo7zst5/2/">https://jsfiddle.net/theblueslate/wxo7zst5/2/</a>

I use XHR with responseType = &quot;document&quot; to load html fragments dynamically. To include them in the document, I use adoptNode(). However, if the XHR parsed document is from a document in quirks mode, and the contents contains a css class that includes an uppercase letter, then adoptNode() imports the element with the css class in lowercase.

importNode() doesn't have this problem, but is more heavyweight than adoptNode().

I can reproduce this problem on Safari 9.1.1 on El Capitan. I also have the same problem on iOS 9.3.2. This problem does not occur on Chrome 51 or IE11.</pre>
        </div>
      </p>
      <hr>
      <span>You are receiving this mail because:</span>
      
      <ul>
          <li>You are the assignee for the bug.</li>
      </ul>
    </body>
</html>