Parsedown is parsing raw URLs as simple links

In Statamic 1.10.2, parsedown appears to be parsing a raw URL as a simple link.

Let's say you've got this randomly in your markdown:

http://foo.com

Parsedown will translate that into a simple link, just as if I'd used the |link variable modifier:

<a href="http://foo.com">http://foo.com</a>

Where that becomes a problem is that I can't seem to pass a URL as a variable to a partial anymore. Instead, it preprocesses the link, and then the partial outputs a doubly nested link like this:

<a href="<a href="http://foo.com">http://foo.com</a>">http://foo.com</a>

...which breaks everything.

Behavior returns to normal when I return to the standard markdown parser.

Am I doing it wrong?