HTML comments containing three backticks

HTML comments containing three backticks seems to break the Markdown parser somehow. In the minimal example below, --- can no longer start a new slide (but treated as a horizontal line instead):

<!DOCTYPE html>
<html>
<head>
  <title>My Problem</title>
  <meta charset="utf-8">
</head>

<body>

<textarea id="source">
## Tags

&lt;!-- ``` --&gt;

---

## Studies

&lt;!-- ``` --&gt;
</textarea>

<script src="https://remarkjs.com/downloads/remark-latest.min.js"></script>
<script>var slideshow = remark.create();
</script>
</body>
</html>

Output:

Originally reported at https://github.com/yihui/xaringan/issues/52

gnab / remark

HTML comments containing three backticks #433