LayoutTests/fast/canvas/access-zero-sized-canvas.html

This test ensures that accessing the context of a zero sized canvas does not crash.
<canvas id="canvas" width="0" height="0"></canvas><br />
<script>
if (window.layoutTestController)
    layoutTestController.dumpAsText();

var context = document.getElementById("canvas").getContext("2d");
context.fillStyle = "green";

</script>