<!DOCTYPE HTML> <html> <!-- https://bugzilla.mozilla.org/show_bug.cgi?id=518777 --> <head> <title>Test for Bug 518777</title> <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script> <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/> <script> SimpleTest.waitForExplicitFinish(); function dotest() { var canvasWidth = 50; var canvasHeight = 50; var source = document.getElementById("source").contentWindow; rect = { left: 25, top: 25, width: canvasWidth, height: canvasHeight }; var canvas = SpecialPowers.snapshotRect(source, rect, "transparent"); var context = canvas.getContext("2d"); var data = context.getImageData(0, 0, canvasWidth, canvasHeight).data; var i; for (i = 0; i < data.length; i += 4) { if (data[i] != 0 || data[i + 1] != 0 || data[i + 2] != 255 || data[i + 3] != 255) break; } ok(i >= data.length, "all pixels blue"); SimpleTest.finish(); } </script> </head> <body> <p><a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=518777">Mozilla Bug 518777</a></p> <!-- iframe source is <html><body onload='window.scrollTo(0,99999999); document.documentElement.offsetWidth; window.parent.dotest();' style='background: rgb(0,0,255); width: 100px; height: 50100px;'></body></html> --> <iframe id="source" width="50" height="50" src="data:text/html,%3Chtml%3E%3Cbody%20onload%3D%27window.scrollTo%280%2C99999999%29%3B%20document.documentElement.offsetWidth%3B%20window.parent.dotest%28%29%3B%27%20style%3D%27background%3A%20rgb%280%2C0%2C255%29%3B%20width%3A%20100px%3B%20height%3A%2050100px%3B%27%3E%3C%2Fbody%3E%3C%2Fhtml%3E"></iframe> <pre id="test"> </pre> </body> </html>