Interesting scenario:

1. click pushState button, to pushState title1.html
2. click "go to this URL" button, to go to title2.html
3. If the browser has a bfcache, close the tab and open it again so the previous page won't get restored from bfcache on the back navigation below
4. Clik "go back" in title2.html, to navigate to title1.html
5. Clik "go back" in title1.html, to navigate to pushState.html.. but it stays in the title1.html