Created attachment 273525 [details] testcase See testcase. The xbl anonymous html element is editable, because it has a contenteditable attribute. I'm not sure if it's wise to let anonymous content be editable. It doesn't seem a good idea to me. The data url xbl in question is: <bindings xmlns="http://www.mozilla.org/xbl"> <binding id="a" inheritstyle="false"> <content><children/> <div xmlns="http://www.w3.org/1999/xhtml" style="border: 1px solid black;" contenteditable="true">anonymous div</div></content> </binding></bindings>
See also bug 401993, "ASSERTION: GetCurrentDoc should have returned a doc" with contenteditable and XBL.