Bukkit/CraftBukkit — pull request #792 by imjake9 (2012-06-13 06:48:57+00:00)
Title: Don't send a player kick message when the message is empty. Fixes BUKKIT-1789.

This simply prevents a blank line from being sent to clients when the disconnect message of a PlayerKickEvent is set to an empty String. This is consistent with behavior for PlayerQuitEvent.

Link to ticket:
https://bukkit.atlassian.net/browse/BUKKIT-1789