po-devs/pokemon-online — pull request #335 by Sulcata (2013-07-27 07:45:00+00:00)
Title: Fixed min damage bug, 5th gen can now have 0 damage

http://pokemon-online.eu/forums/showthread.php?21272-Minimum-damage-bug&p=298890&viewfull=1#post298890

Not sure what the behavior is for past gens, so that was left as is.