mathml/crashtests/mozilla/1435015.html - external/github.com/web-platform-tests/wpt - Git at Google

 <!doctype html>
 <style>
   div { display: contents; }
 </style>
 <math></math>
 <script>
   let div = document.createElementNS('http://www.w3.org/1998/Math/MathML', 'div');
   document.querySelector('math').appendChild(div);
 </script>
	<!doctype html>
	<style>
	div { display: contents; }
	</style>
	<math></math>
	<script>
	let div = document.createElementNS('http://www.w3.org/1998/Math/MathML', 'div');
	document.querySelector('math').appendChild(div);
	</script>