From 0bde47a173dacd155da3f0715abfcba9455e0f17 Mon Sep 17 00:00:00 2001
From: John Driscoll <johnoliverdriscoll@gmail.com>
Date: Wed, 8 Aug 2012 00:42:18 -0700
Subject: [PATCH] Don't extend pistons until data is set. Fixes BUKKIT-2153

---
 src/main/java/net/minecraft/server/BlockPiston.java | 2 +-
 src/main/java/net/minecraft/server/Chunk.java       | 6 +++++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/main/java/net/minecraft/server/BlockPiston.java b/src/main/java/net/minecraft/server/BlockPiston.java
index 3bf3752ab8..2944eca761 100644
--- a/src/main/java/net/minecraft/server/BlockPiston.java
+++ b/src/main/java/net/minecraft/server/BlockPiston.java
@@ -55,7 +55,7 @@ public class BlockPiston extends Block {
 
     public void onPlace(World world, int i, int j, int k) {
         if (!world.isStatic && world.getTileEntity(i, j, k) == null) {
-            // this.l(world, i, j, k); // CraftBukkit - don't extend arm of piston that doesn't exist
+            this.l(world, i, j, k);
         }
     }
 
diff --git a/src/main/java/net/minecraft/server/Chunk.java b/src/main/java/net/minecraft/server/Chunk.java
index 31cdcd5547..192cd6f17b 100644
--- a/src/main/java/net/minecraft/server/Chunk.java
+++ b/src/main/java/net/minecraft/server/Chunk.java
@@ -417,7 +417,11 @@ public class Chunk {
 
                 if (l != 0) {
                     if (!this.world.isStatic) {
-                        Block.byId[l].onPlace(this.world, j2, j, k2);
+                        // CraftBukkit start - Don't extend piston until data is set
+                        if (!(Block.byId[l] instanceof BlockPiston) || i2 != 0) {
+                            Block.byId[l].onPlace(this.world, j2, j, k2);
+                        }
+                        // CraftBukkit end
                     }
 
                     if (Block.byId[l] instanceof BlockContainer) {