Markdown: problem when rendering source with prepending whitespace

In a template like this:
```
<pre class="pat-markdown">
    ${context/text}
</pre>
```

Where ``${context/text}`` outputs this:
```
    *This is markdown*
```

The rendered markdown is:
```
<pre class="pat-syntax-highlight" tabindex="0"><code data-inner="1">*This is markdown*</code></pre>
```

Instead of:
```
<p><em>This is markdown</em></p>
```