849601.html (760B)
1 <!DOCTYPE html> 2 <html> 3 <head> 4 <meta charset="UTF-8"> 5 <script> 6 7 function addEmptyMutationObserver() 8 { 9 var m = new MutationObserver(function () {}); 10 var e = document.createElement('i'); 11 m.observe(e, { childList: true }); 12 } 13 14 function addPointlessMutationListener() 15 { 16 var a = document.createElementNS("http://www.w3.org/1999/xhtml", "div"); 17 a.appendChild(document.createTextNode("1")); 18 19 function f() { 20 window.removeEventListener("DOMSubtreeModified", f); 21 a.insertAdjacentHTML("afterBegin", "<span></span>"); 22 }; 23 24 window.addEventListener("DOMSubtreeModified", f); 25 } 26 27 function boom() 28 { 29 addEmptyMutationObserver(); 30 addPointlessMutationListener(); 31 document.body.outerHTML = ""; 32 } 33 34 </script> 35 </head> 36 37 <body onload="boom();"></body> 38 </html>