AD while-loop conversion bug.

[zfnmxt]

At the moment, while loops are transformed into a for-loop with a if-then-else for the body, which does an iteration of the original loop if the original condition on the while loop holds and otherwise simply returns the current loop variable(s). This isn't quite correct: we should return the current loop variables(s) if the original condition has ever been met.

[athas]

Do we have a test for this?

[zfnmxt]

No, but I'll make one when I fix it (tonight or tomorrow).

[zfnmxt]

I see now why you've asked about a test--this isn't actually a bug (and hence I cannot construct a test for it). I thought it might be an issue due to the bound annotations but if the while-loop's stopping condition ever holds (when it is checked) then it must continue to hold because it'll simply return the current loop variables without modification.