Getting some interesting results, as you can see in the attached pictures, with the following html that does not seem to render properly in the Sun’s render engine:
As for the “Sun’s render engine”, this is the single worst piece of crap in the whole Swing API, the culprit’s real name is javax.swing.text.html.HTMLEditorKit.
So yes, you can blame Sun (Oracle?) for that, because every living implementation of a html editor in Java suffers from its numerous bugs, and it has never been properly fixed!