Why isn't MarkdownSharp encoding my HTML?

In my mind, one of the bigger goals of Markdown is to prevent the user from typing potentially malformed HTML directly.

Well that isn't exactly working for me in MarkdownSharp.

This example works properly when you have the extra line break immediately after "abc"... enter image description here

But when that line break isn't there, I think it should still be HtmlEncoded, but that isn't happening here... enter image description here

Behind the scenes, the rendered markup is coming from an iframe. And this is the code behind it...

<% 
var md = new MarkdownSharp.Markdown();
%>
<%= md.Transform(Request.Form[0]) %>

Surely I must be missing something. Oh, and I am using v1.13 (the latest version as of this writing).

EDIT (this is a test for StackOverflow's implementation)

abc

this shouldn't be red

Solution

Since it became clear that the StackOverflow implementation contains quite a few customizations that could be time consuming to test and figure out, I decided to go another direction.

I created my own simplified markup language that's a subset of Markdown. The open-source project is at http://ultralight.codeplex.com/ and you can see a working example at http://www.bucketsoft.com/ultralight/

The project is a complete ASP.NET MVC solution with a Javascript editor. And unlike MarkdownSharp, safe HTML is guaranteed. The Javascript parser is used both client-side and server-side to guarantee consistent markup (special thanks to the Jurassic Javascript compiler). It's a beautiful thing to only have to maintain one codebase for that parser.

Although the project is still in beta, I'm using it on my own site already and it seems to be working well so far.