This question already has an answer here:
A piece of markdown like this:
I was trying to do something with [this website], but it didn't work. How do I fix it? : //example.com "Home - http://example.com, this website's tagline."
I was trying to do something with http://example.com, this website's tagline">this website, but it didn't work. How do I fix it?
As you can see, the HTML tag is closed just before the url string.
This is probably caused by the automatic link identifier being invoked everywhere, instead of just in the main post body. It's not invoked in places such as blockquotes (see above), inline code (e.g.
http://example.com) or the URL part of a link (i.e. this doesn't link to
<a>http://example.com</a>), so this seems like it could be fixed without rewriting the whole codebase.