<window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
        title="Bug 386642 Crash [@ IsCanvasFrame] while opening context menu or changing styles">
<toolbarbutton type="menu" id="a">
<menupopup id="b"/>
</toolbarbutton>

<style xmlns="http://www.w3.org/1999/xhtml">
.one image {
display: -moz-box;
}
image{
display: none;
}

</style>
<script><![CDATA[
var gg=0;
function doe() {
  var a = document.getElementById('a');
  if (!a.hasAttribute('class')) {
    a.setAttribute('class', 'one');
  } else {
    a.removeAttribute('class');
  }
document.getElementById('b').hidePopup();
}

doe();
setInterval(doe, 200);
]]></script>
</window>