File: //usr/share/doc/libjs-excanvas/examples/testcases/overflow.html
<!DOCTYPE html>
<html>
<head>
<title>Overflow Test</title>
<style>
body {
text-align: center
}
</style>
<!--[if IE]><script type="text/javascript" src="../excanvas.js"></script><![endif]-->
<script>
window.onload = function() {
var ctx = document.getElementById('c').getContext('2d');
ctx.fillStyle = 'blue';
ctx.fillRect(-50, -50, 100, 100);
ctx.fillStyle = 'green';
ctx.fillRect(50, 50, 100, 100);
ctx.strokeStyle = 'black';
ctx.strokeRect(0, 0, 100, 100);
};
</script>
</head>
<body>
<canvas id=c width=100 height=100></canvas>
<p>This tests if content gets cropped if painting outside the canvas.</p>
</body>
</html>