I don't believe it matters much anymore, so I'm writing about a bug (or maybe a feature back then) in Google URL Shortener. As far as I tested today it's already taken care of.
In short, I think there was a chain-of-shortened-URLs bug, so to speak. On the release day or so I read about the URL shortener and tried it to see if how it was different from other shorteners. I liked the simple interface with some extra features like access stats and 2D matrix bar codes. Anyways, then it occured to me if it can shorten just any URL (well, even when they are descending people still call moving staircases an escalator...).
So an URL 'http://goo.gl/' is obviously shorter than URLs "shortened" by goo.gl. Unexpectedly goo.gl actually lengthened the URL, with a hash code:
Then I also wondered what would goo.gl return if a shortened URL by goo.gl itself, i.e. "was given. The result:
my days and responses: Google Translator Toolkit
As for goo.gl I don't know what's been going on, so I can't say if it was really a bug, but to me there were lessons learned:
- Try to find test cases carefully (and never think they are complete).
- Users might help you reporting bugs if you are little more friendly :)
Common sense, but really important...