Similar thing happened with me too. In that dream, code was scrolling by, fast. Then it stopped abruptly, and one line grabbed my whole mental focus. And it was a bug! Next day I checked the application I was working at that time, and indeed it was there. Probably I have noticed it before, just forget about it.
I'm should be more amazed at how I can wake up with a bugfix to make in the middle of 1500 LOC from the day or days before. It's something of a once-or-twice-the-month event, and tends to pass by without me paying much attention.
