From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Fri, 17 Jun 2016 20:50:11 -0400
Subject: [PATCH] Fix Old Sign Conversion

1) Sign loading code was trying to parse the JSON before the check for oldSign.
   That code could then skip the old sign converting code if it triggers a JSON parse exception.
2) New Mojang Schematic system has Tile Entities in the new converted format, but missing the Bukkit.isConverted flag
   This causes Igloos and such to render broken signs. We fix this by ignoring sign conversion for Defined Structures

diff --git a/src/main/java/net/minecraft/world/level/block/entity/BlockEntity.java b/src/main/java/net/minecraft/world/level/block/entity/BlockEntity.java
index 66ab4deedd177f507d170a61ceca4c3ebbac9adc..77645019c88d61dde28b7598d8a29b7d0c23c209 100644
--- a/src/main/java/net/minecraft/world/level/block/entity/BlockEntity.java
+++ b/src/main/java/net/minecraft/world/level/block/entity/BlockEntity.java
@@ -30,6 +30,7 @@ public abstract class BlockEntity implements net.minecraft.server.KeyedObject {
     public CraftPersistentDataContainer persistentDataContainer;
     // CraftBukkit end
     private static final Logger LOGGER = LogManager.getLogger();
+    public boolean isLoadingStructure = false; // Paper
     private final BlockEntityType<?> type;
     @Nullable
     protected Level level;
diff --git a/src/main/java/net/minecraft/world/level/block/entity/SignBlockEntity.java b/src/main/java/net/minecraft/world/level/block/entity/SignBlockEntity.java
index dbb59775422b80fb4b60a8cfd2c0bd81c1646e88..589fbdd5c86655244aa92a42e5f45747b5c5026e 100644
--- a/src/main/java/net/minecraft/world/level/block/entity/SignBlockEntity.java
+++ b/src/main/java/net/minecraft/world/level/block/entity/SignBlockEntity.java
@@ -95,7 +95,7 @@ public class SignBlockEntity extends BlockEntity implements CommandSource { // C
                 s = "\"\"";
             }
 
-            if (oldSign) {
+            if (oldSign && !this.isLoadingStructure) { // Paper - saved structures will be in the new format, but will not have isConverted
                 this.messages[i] = org.bukkit.craftbukkit.util.CraftChatMessage.fromString(s)[0];
                 continue;
             }
diff --git a/src/main/java/net/minecraft/world/level/levelgen/structure/templatesystem/StructureTemplate.java b/src/main/java/net/minecraft/world/level/levelgen/structure/templatesystem/StructureTemplate.java
index e396c3aede9ca22ec98e1bd25c7da35ed6406f4f..80d3787d9c07f8dd740c2e5979e1cc14891b8829 100644
--- a/src/main/java/net/minecraft/world/level/levelgen/structure/templatesystem/StructureTemplate.java
+++ b/src/main/java/net/minecraft/world/level/levelgen/structure/templatesystem/StructureTemplate.java
@@ -283,7 +283,9 @@ public class StructureTemplate {
                                         definedstructure_blockinfo.nbt.putLong("LootTableSeed", random.nextLong());
                                     }
 
+                                    tileentity.isLoadingStructure = true; // Paper
                                     tileentity.load(definedstructure_blockinfo.nbt);
+                                    tileentity.isLoadingStructure = false; // Paper
                                 }
                             }