World can be null for sign conversion, fixes #886

Spigot-Server-Patches/Avoid-NPE-during-CraftBlockEntityState-load.patch

@@ -4,8 +4,21 @@ Date: Mon, 18 Sep 2017 13:38:40 -0700
 Subject: [PATCH] Avoid NPE during CraftBlockEntityState load
 
 
+diff --git a/src/main/java/net/minecraft/server/TileEntitySign.java b/src/main/java/net/minecraft/server/TileEntitySign.java
+index 54b719d91..3f2c5b2d5 100644
+--- a/src/main/java/net/minecraft/server/TileEntitySign.java
++++ b/src/main/java/net/minecraft/server/TileEntitySign.java
+@@ -0,0 +0,0 @@ public class TileEntitySign extends TileEntity {
+             }
+ 
+             public MinecraftServer C_() {
+-                return TileEntitySign.this.world.getMinecraftServer();
++                return MinecraftServer.getServer(); // Paper - world may be null
+             }
+         };
+ 
 diff --git a/src/main/java/org/bukkit/craftbukkit/block/CraftBlockEntityState.java b/src/main/java/org/bukkit/craftbukkit/block/CraftBlockEntityState.java
-index 266f87d7..22dcaea7 100644
+index 266f87d7f..22dcaea72 100644
 --- a/src/main/java/org/bukkit/craftbukkit/block/CraftBlockEntityState.java
 +++ b/src/main/java/org/bukkit/craftbukkit/block/CraftBlockEntityState.java
 @@ -0,0 +0,0 @@ public class CraftBlockEntityState<T extends TileEntity> extends CraftBlockState