<!DOCTYPE HTML> <html> <body onload="test();"> <script> function test() { // Test that calling pushState() with a state object which calls // history.back() doesn't crash. We need to make sure that there's at least // one entry in the history before we do anything else. history.pushState(null, ""); x = {}; x.toJSON = { history.back(); return "{a:1}"; }; history.pushState(x, ""); } </script> </body> </html>