SpigotMC/Spigot-Server — pull request #73 by ams2990 (2014-01-17 19:07:27+00:00)
Title: Fix Piston Event Behavior

Please see [CraftBukkit#1305](https://github.com/Bukkit/CraftBukkit/pull/1305). This change contains two fixes: it prevents BlockPistonExtendEvent from firing twice and cancels the piston extension or retraction when the event is cancelled.