gecko-dev/layout/mathml/crashtests/654928-1.html

зеркало из https://github.com/mozilla/gecko-dev.git
<html>
  <math><maction selection="2">A<mo>B</mo></maction></math>
</html>
	`<html>`
	`<math><maction selection="2">A<mo>B</mo></maction></math>`
	`</html>`