Tools/TestWebKitAPI/Tests/WebKitCocoa/duplicate-completion-handler-calls.html - WebKit - Git at Google

 <!DOCTYPE html>
 <form action="about:blank"></form>
 <script>
     alert("alert");
     confirm("confirm");
     prompt("prompt");
     window.indexedDB.open("DuplicateCompletionHandlerCallsDatabase");
     document.forms[0].submit();
 </script>
	<!DOCTYPE html>
	<form action="about:blank"></form>
	<script>
	alert("alert");
	confirm("confirm");
	prompt("prompt");
	window.indexedDB.open("DuplicateCompletionHandlerCallsDatabase");
	document.forms[0].submit();
	</script>