Single-space blank line evicts a list-item continuation

[numist]

- [r]:x\n\n\n l and - [r]:x\n\n \n l both produce

<ul>
<li>l</li>
</ul>

But the single-space blank line in - [r]:x\n\n \n l appears to break the list-item continuation, producing:

<ul>
<li></li>
</ul>
<p>l</p>