Many young or new developers have sometimes hard to deal mind set. Imagine you are developing big product and you about to release it. And then QA found problem that must be fixed. Fix is small and it looks like it is affecting only really small area that can be easily tested. And there is temptation to fix it, test only that small area by R&D and release it. And I will show that there is no such thing as safe change.

But before I will go to example from my experience, I have to remind you, that any application has a lot of bugs. Even “hello world” application can have some bugs especially if it does use run-time library.