Refactoring C Code: Starting With an API

In my last post, I introduced a basic error handling mechanism for C API. The code I showed had a small memory leak in it. I love that fact about it, because it is hidden away and probably won’t show up very easily for production code until very late in the game. Here is the fix:
The problem was that I was freeing the error struct, but wasn’t freeing the actual error message. That is something that is very easy to miss, unfortunately. Especially as we assume that errors are rare. With that minor issue out of the way, let’s look at how we actually write the code. Here is the updated version of creating a connection, with proper error handling: