IIRC, there are several possible shortest legs in elapsed time (in each possible instance I can think of, there were two legs in or near the same city and one was the short duration leg (e.g., Delhi, Beijing, Moscow, Shanghai, etc.) In more recent seasons, it would be almost impossible to be certain as check in and departure times have been inconsistently provided on air, if at all.
The longest leg, IIRC, in duration was TAR 9 from Brotas, Brazil to Moscow, Russia, to Munich, Germany. It was an uberleg (which aren't used anymore) with the midpoint in Red Square.