Bukkit/CraftBukkit — pull request #896 by ScoreUnder (2012-10-03 02:39:59+00:00)
Title: Fix clientside sign blanking

(Copied from commit :P)
If a block break on a sign or mob spawner was cancelled, the client would
display an empty sign or a pig spawner in its place. This fixes that issue
by re-sending any additional tile-entity data whenever it re-sends a block
that is not known to not be a tile entity.