Paper/CraftBukkit-Patches/0029-Prevent-NPE-in-CraftSign.patch

From 8fa12a2dc27cf3f73af9301b2e20beaa5d438be9 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 1647100..43c4434 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
             for(int i = 0; i < 4; i++) {
                 if(lines[i] != null) {
                     sign.lines[i] = lines[i];
-- 
1.8.2.1