<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 - I found one more onbeforeunload event return value coercion edge case"
   href="https://bugs.webkit.org/show_bug.cgi?id=169789">169789</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>I found one more onbeforeunload event return value coercion edge case
          </td>
        </tr>

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

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

        <tr>
          <th>Version</th>
          <td>Safari Technology Preview
          </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 Events
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>d&#64;domenic.me
          </td>
        </tr></table>
      <p>
        <div>
        <pre>The newly-introduced test at <a href="http://w3c-test.org/html/browsers/browsing-the-web/unloading-documents/beforeunload-canceling.html">http://w3c-test.org/html/browsers/browsing-the-web/unloading-documents/beforeunload-canceling.html</a> named

<span class="quote">&gt; Returning false must not cancel the event, because it's coerced to the DOMString &quot;false&quot; which does not cancel CustomEvents: CustomEvent, cancelable</span >

does not pass in Safari Tech Preview 25. Everything else does (except the test &quot;Returning a string must not cancel the event: BeforeUnloadEvent with type &quot;click&quot;, cancelable&quot; which is fine since it's best if Safari doesn't implement createEvent(&quot;beforeunload&quot;); see <a href="https://github.com/whatwg/dom/issues/362">https://github.com/whatwg/dom/issues/362</a>.)</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>