From 1370eab3d6f63ae56c9c02765f5f0c216a847716 Mon Sep 17 00:00:00 2001
From: Byteflux <byte@byteflux.net>
Date: Sun, 30 Nov 2014 18:58:07 -0600
Subject: [PATCH] Allow specified ItemStacks to retain their invalid data


diff --git a/src/main/java/net/minecraft/server/ItemStack.java b/src/main/java/net/minecraft/server/ItemStack.java
index de60437..bace99c 100644
--- a/src/main/java/net/minecraft/server/ItemStack.java
+++ b/src/main/java/net/minecraft/server/ItemStack.java
@@ -17,6 +17,8 @@ import org.bukkit.entity.Player;
 import org.bukkit.event.world.StructureGrowEvent;
 // CraftBukkit end
 
+import org.github.paperspigot.PaperSpigotConfig; // PaperSpigot
+
 public final class ItemStack {
 
     public static final DecimalFormat a = new DecimalFormat("#.###");
@@ -306,9 +308,13 @@ public final class ItemStack {
         }
 
         // Is this a block?
-        if (CraftMagicNumbers.getBlock(CraftMagicNumbers.getId(this.getItem())) != Blocks.AIR) {
+        // PaperSpigot start - Allow specific blocks to retain their data values
+        int id = CraftMagicNumbers.getId(this.getItem());
+        if (CraftMagicNumbers.getBlock(id) != Blocks.AIR) {
             // If vanilla doesn't use data on it don't allow any
-            if (!(this.usesData() || this.getItem().usesDurability())) {
+            if ((PaperSpigotConfig.dataValueAllowedItems == null || !PaperSpigotConfig.dataValueAllowedItems.contains(id)) &&
+                    (!(this.usesData() || this.getItem().usesDurability()))) {
+            // PaperSpigot end
                 i = 0;
             }
         }
diff --git a/src/main/java/org/github/paperspigot/PaperSpigotConfig.java b/src/main/java/org/github/paperspigot/PaperSpigotConfig.java
index c57f83b..19ef586 100644
--- a/src/main/java/org/github/paperspigot/PaperSpigotConfig.java
+++ b/src/main/java/org/github/paperspigot/PaperSpigotConfig.java
@@ -6,11 +6,10 @@ import java.io.IOException;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 import java.util.logging.Level;
 import net.minecraft.server.MinecraftServer;
+import org.apache.commons.lang.StringUtils;
 import org.bukkit.Bukkit;
 import org.bukkit.command.Command;
 import org.bukkit.configuration.InvalidConfigurationException;
@@ -171,4 +170,11 @@ public class PaperSpigotConfig
         strengthEffectModifier = getDouble( "effect-modifiers.strength", 1.3D );
         weaknessEffectModifier = getDouble( "effect-modifiers.weakness", -0.5D );
     }
+
+    public static Set<Integer> dataValueAllowedItems;
+    private static void dataValueAllowedItems()
+    {
+        dataValueAllowedItems = new HashSet<Integer>( getList( "data-value-allowed-items", Collections.emptyList() ) );
+        Bukkit.getLogger().info( "Data value allowed items: " + StringUtils.join(dataValueAllowedItems, ", ") );
+    }
 }
-- 
1.9.1