In Google Chrome in version 19 the solution from @spliter stopped working. As @johnnymire pointed out, history.state in Chrome 19 exists, but it’s null.
My workaround is to add window.history.state !== null into checking if state exists in window.history:
var popped = ('state' in window.history && window.history.state !== null), initialURL = location.href;
I tested it in all major browsers and in Chrome versions 19 and 18. It looks like it works.