Tracking Down a Tricky Problem
I just finished spending a good hour tracking down a nasty little problem with the logic I had for creating new instruments on the fly. The problem turned out to really be me, and my preconceived notions about what the problem really was, but that's typically the case. The underlying problem was that I was thinking that the first new message for an instrument wasn't creating the underlying, but in fact, it was. That explained why I was seeing no errors.
No… the real problem was that I wasn't properly handling the case when I found it. It was made, but then the next time, I tried to find it, and it was missing - or so the code thought. In reality, I had failed to really detect that I'd found it, and act accordingly.
It's almost a coding standard in my mind now - For every 'if' statement, there had better be an 'else' clause. It would have saved me this headache, and when I saw it, it was clear that I was missing the else, and what to put in it when the value wasn't NULL.
Glad that's over. It was painful.