Thor:
Thank you... I hadn't seen that little gem before. So the code was "auditable" but it sounds like, in the light of that revelation, we can add a fourth reason:-
4. Those charged with auditing the code find such an unholy mess they throw up their hands and give up.
I have had to update other people's code in the past and, on occasion, I find it so badly written that, rather then edit, I would rewrite from scratch for two reasons:-
- I simply can't trust the code to be bug free in any, let alone all, circumstances - in the context of the FADEC code read: "safe"
- I cannot be sure in any circumstances that any edit I might do to one section of the code might not cause the unpredictable failure of another module.
Interestingly enough a rewrite is exactly what the last line of what you quoted suggested. Unfortunately, that would probably have been impossible fiscally, practically and politically which is probably why it has been swept under the rug...