<!DOCTYPE html> <html lang="en"> <meta charset="utf-8"> <title>Moving a layer in a box with a rounded clip shouldn't invalidate.</title> <style> #outer { position: absolute; top: 50px; left: 50px; width: 300px; height: 200px; background-color: #DDD; overflow: hidden; border-radius: 10px; } #animatedLeft { position: absolute; top: 50px; left: 40px; box-model: border-box; border: 1px solid lime; width: 100px; height: 100px; } </style> <body> <div id="outer"> <div id="animatedLeft" class="reftest-no-paint"></div> </div> <script> var animatedLeft = document.getElementById("animatedLeft"); function doTest() { animatedLeft.style.left = "100px"; document.documentElement.removeAttribute("class"); } // Layerize #animatedLeft animatedLeft.offsetLeft; animatedLeft.style.left = "60px"; animatedLeft.offsetLeft; animatedLeft.style.left = "40px"; animatedLeft.offsetLeft; document.addEventListener("MozReftestInvalidate", doTest); </script>