enclosed parentheses in markdown links not rendered properly in html

[rheewalt]

When given the following input:

[some link](www.foo.com?param=(null))

blackfriday converts that input into:

<p><a href="www.foo.com?param=(null">some link</a>)</p>

Visually this will look like some link) and the link url will be www.foo.com?param=(null

Expected behavior would be: some link