[Tobba_]

This is what happens when you don't have a QA department.

[bonzini]

This is something that you find through code review, not testing. Apart from regression testing, but that presupposes that you encountered the issue before.

[efdee]

Are you implying that Microsoft doesn't do QA?

[Tobba_]

If they do, whatever issues they're occupied with finding would call for an exorcism.