Add obfuscation helper patch to assist update process.

By: md_5 <git@md-5.net>

CraftBukkit-Patches/0022-Prevent-NPE-in-CraftSign.patch

@@ -0,0 +1,36 @@
+From 497af5fb267959f215b8ac57de702065a48ae931 Mon Sep 17 00:00:00 2001
+From: md_5 <md_5@live.com.au>
+Date: Mon, 18 Mar 2013 20:01:44 +1100
+Subject: [PATCH] Prevent NPE in CraftSign
+
+This commit prevents the constructor of CraftSign throwing an NPE when it cannot get the sign tile entity. Instead it will fallback to a 4 empty lined sign, and not try to do anything to those lines on .update().
+
+diff --git a/src/main/java/org/bukkit/craftbukkit/block/CraftSign.java b/src/main/java/org/bukkit/craftbukkit/block/CraftSign.java
+index 77717d5..1533dd4 100644
+--- a/src/main/java/org/bukkit/craftbukkit/block/CraftSign.java
++++ b/src/main/java/org/bukkit/craftbukkit/block/CraftSign.java
+@@ -14,6 +14,12 @@ public class CraftSign extends CraftBlockState implements Sign {
+ 
+         CraftWorld world = (CraftWorld) block.getWorld();
+         sign = (TileEntitySign) world.getTileEntityAt(getX(), getY(), getZ());
++        // Spigot start
++        if (sign == null) {
++            lines = new String[]{"", "", "", ""};
++            return;
++        }
++        // Spigot end
+         lines = new String[sign.lines.length];
+         System.arraycopy(sign.lines, 0, lines, 0, lines.length);
+     }
+@@ -34,7 +40,7 @@ public class CraftSign extends CraftBlockState implements Sign {
+     public boolean update(boolean force, boolean applyPhysics) {
+         boolean result = super.update(force, applyPhysics);
+ 
+-        if (result) {
++        if (result && sign != null) { // Spigot, add null check
+             sign.lines = sanitizeLines(lines);
+             sign.update();
+         }
+-- 
+1.8.3.2
+