Last year, at WUC 2008, I did a presentation called Common WebGUI Programming mistakes.  For the previous year, I kept track of everything that I found in the codebase that was wrong, dangerous, or that really bothered me.  Then I'd write up an example for it and ask people in the audience if they could tell what was wrong with it.  If they got it right, I had candy (and beer for Martin).

Examples ranged from dangerous references, to several mistakes people make with constructors (including guessing their names) to not making good SVN comments.  It sounded like people had fun, and I did, too.

I'm not repeating that talk in 2009, so as I find bad things I'm going to blog about them.  Some people may ask why I'd blog about bad things in the product that I work on.  The answer is simple, it's Open Source.   The mistakes are there for anyone to find, and to correct.  So why not expose them, talk about why they're bad, and then fix them!

First example follows.