AlexanderOMara · October 16, 2016 22:50
diff --git a/index.html b/index.html
 <!DOCTYPE html>
 <html>
 <head>
 <meta charset="utf-8" />
 <meta http-equiv="Content-Security-Policy" content="default-src 'self' 'unsafe-inline' stackoverflow.com;">
 <title>Are you logged in to Stack Overflow?</title>
 </head>
 <body>
 	<h1>Are you logged in to Stack Overflow?<h1>
 	<h2 id="answer">...<h2>
 <script>
 (function() {
 'use strict';
 // We allow without the www, not with, so that redirect will fail.
 var redir = 'http://www.stackoverflow.com';
 var notTimeout;
 var finished = false;
 var answer = document.getElementById('answer');
 window.addEventListener('securitypolicyviolation', function(e) {
 	// If the CSP error is the one expected, then an active session.
 	if (e.blockedURI.indexOf(redir) === 0) {
 		if (notTimeout) {
 			clearTimeout(notTimeout);
 		}
 		answer.textContent = 'Yes';
 		finished = true;
 	}
 }, true);
 function done() {
 	// Wait until the CSP error that follows is fired.
 	if (!finished) {
 		notTimeout = setTimeout(function() {
 			answer.textContent = 'No';
 		}, 100);
 	}
 }
 var img = document.createElement('img');
 img.addEventListener('load', done);
 img.addEventListener('error', done);
 img.src =
 	'https://stackoverflow.com/users/login?ssrc=head&returnurl=' +
 	encodeURIComponent(redir) +
 	'&_=' + Date.now();
 })();
 </script>
 </body>
 </html>
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8" />
	<meta http-equiv="Content-Security-Policy" content="default-src 'self' 'unsafe-inline' stackoverflow.com;">
	<title>Are you logged in to Stack Overflow?</title>
	</head>
	<body>
	<h1>Are you logged in to Stack Overflow?<h1>
	<h2 id="answer">...<h2>
	<script>
	(function() {
	'use strict';
	// We allow without the www, not with, so that redirect will fail.
	var redir = 'http://www.stackoverflow.com';
	var notTimeout;
	var finished = false;
	var answer = document.getElementById('answer');
	window.addEventListener('securitypolicyviolation', function(e) {
	// If the CSP error is the one expected, then an active session.
	if (e.blockedURI.indexOf(redir) === 0) {
	if (notTimeout) {
	clearTimeout(notTimeout);
	}
	answer.textContent = 'Yes';
	finished = true;
	}
	}, true);
	function done() {
	// Wait until the CSP error that follows is fired.
	if (!finished) {
	notTimeout = setTimeout(function() {
	answer.textContent = 'No';
	}, 100);
	}
	}
	var img = document.createElement('img');
	img.addEventListener('load', done);
	img.addEventListener('error', done);
	img.src =
	'https://stackoverflow.com/users/login?ssrc=head&returnurl=' +
	encodeURIComponent(redir) +
	'&_=' + Date.now();
	})();
	</script>
	</body>
	</html>