The Tor Browser / file revision

 function test() {

   waitForExplicitFinish();

   var htmlContent = "data:text/html, <iframe src='data:text/html,text text'></iframe>";

   gBrowser.addEventListener("pageshow", onPageShow, false);

   gBrowser.loadURI(htmlContent);

 }

 function onPageShow() {

     gBrowser.removeEventListener("pageshow", onPageShow, false);

     var frame = content.frames[0];

     var sel = frame.getSelection();

     var range = frame.document.createRange();

     var tn = frame.document.body.childNodes[0];

     range.setStart(tn , 4);

     range.setEnd(tn , 5);

     sel.addRange(range);

     frame.focus();

     document.popupNode = frame.document.body;

     var contentAreaContextMenu = document.getElementById("contentAreaContextMenu");

     var contextMenu = new nsContextMenu(contentAreaContextMenu);

     ok(document.getElementById("frame-sep").hidden, "'frame-sep' should be hidden if the selection contains only spaces");

     finish();

 }