I've created a page for testing and debugging our parser: http://meta.wikipedia.org/wiki/Parser_testing
It's far from complete, but anyone with a knowledge of our syntax can add to it and I hope it grows into something useful. So if you want to help debugging the software but don't know how, please contribute here.
There should be one section for each test. A test can consist of a variety of individual cases, all of which should be added first as <pre>..</pre>, then verbatim, so that the difference between user input and parser output can be seen.
One bug I noticed is that mixed lists seem to no longer work, unless I'm missing something. I also think that we shouldn't use stuff like "left" and "50px" as image alt text.
It's not always obvious what we *want* our behavior to be. Right now I'm assuming that everything the parser does is correct unless the result is really strange.
Kudos to Jens for the image caption parsing code, it seems to grok almost anything.
Regards,
Erik