How to check for valid richtext syntax?

[Noordfrees]

Is there a way to determine whether a string is valid Widelands richtext without actually rendering it?

Currently I'm testing it by rendering the text (UI::g_fh->render(my_text, 500);) and checking whether an exception is thrown.
This has several disadvantages: It's slow; it causes large memory leaks if there really are invalid tags (which can be expected to be the case quite often); and sometimes it prints masses of undesired logs and sometimes even segfaults if I pass extremely weird data. Is there a better way?

Background: In my https://github.com/Noordfrees/widelands/tree/addons-webserver branch, which is 99% complete, I'm just polishing the UI to write comments about add-ons, and it comes with a preview pane that shows the user what his text will look like:

If there is no way to check this, an alternative would be to implement a simple markdown-to-richtext converter that interprets the user's comment as markdown and generates guaranteed valid richtext… but I'd rather keep it simple :)
Or should I do this anyway, since markup is easier to write than Widelands richtext?

[frankystone]

Some people are struggling with markdown also. I guess this is one of the reasons why our wiki isn't updated regularly and github provides some markup buttons at the top of editboxes. A markdown-wlrichtext converter makes writing wlrichtext easier, but for some people it might be too complicated anyway.

To make it really easy for users i think there should be some markup-buttons on top of an editbox, like e.g. github has. In the long run this would also be useful for a scenario editor to apply wlrichtext to campaign windows or objectives.

For addon-comments i think wlrichtext it is not really needed. At least for now. I guess most comments will be of type:

Nice addon. What i don't like is xy... better make it like z.

The ability to apply newlines should be enough for now, imho.

[Noordfrees]

Unfortunately we need wlrichtext for the <br> tags, otherwise the entire text would appear on a single line. So we need to support the full RT scope there. It would also be good to allow smiley substitutions with image tags like on the homepage.
Markup buttons are a very good idea, will implement this :)