I agree that it's the logical behavior. But I think there's a difference between your examples and mine: in your examples, you are comparing two different statements, which have a definite execution order. In this case, you have a list, which does have a definite order -- in     %c=(%a, %b); the keys and values of %b come after the keys and values of %a. But the question is whether that order plays a predictable role in the conversion of the list into a hash.

Common sense says that it should. But common sense is not always a predictor of future behavior.