<!DOCTYPE html>
<body>
	<p>This should not crash.</p>
	<script>
    	if (window.testRunner)
        	testRunner.dumpAsText();
    	const svgns = "http://www.w3.org/2000/svg";
    	let path = document.createElementNS(svgns, "path");
    	let pathSegList = path.pathSegList;
    	let pathSeg = path.createSVGPathSegCurvetoCubicSmoothAbs(0, 0, 1, 1);
    	pathSegList.insertItemBefore(pathSeg, 1);
    	path.setAttribute("d", "M 0 0");
    	pathSegList.insertItemBefore(pathSeg, 0);
	</script>
</body>