Bukkit/CraftBukkit — pull request #612 by mrapple (2011-12-30 05:00:02+00:00)
Title: Let the client know blocks still exist when break events are cancelled

This is the same method used previously in the code when a block is broken in the spawn radius and shouldn't break.

Fixes the annoying glitch where a block will not reappear for a few seconds after you have broken it, but the break (or left click interact) event was cancelled.