Challenge freezing on incorrect input #39101
Description
Describe your problem and how to reproduce it:
The Define the Head and Body of an HTML Document challenge freezes if you enter in code like
<!DOCTYPE html>
<html>
<head>
<title>The best page ever</title>
<head>
<body>
<h1>The best page ever</h1>
<p>Cat ipsum dolor sit amet, jump </p>
<body> <!-- this tag should be closing -->
</html>where the body tag is not closed. This is a common enough mistake and the freezing is not directly caused by the user code - it's how our tests interact with it.
Add a Link to the page with the problem:
The cause
The last test causes the problem, I think the regex gets stuck in a loop.