This tests a bug when copying HTML markup inside <pre> tags. When pasted, this content would appear as the rendered form of that markup.
You should see markup in the editable region below. See <rdar://5027857>.
| <pre>
|   contenteditable="true"
|   id="pre"
|   "<input type='button'>foo<br>bar<b>baz</b><#selection-caret>"