Fix BlockEntityTag being stripped from items

src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java

@@ -196,16 +196,20 @@ class CraftMetaItem implements ItemMeta, Repairable {
     static final ItemMetaKey ATTRIBUTES_UUID_HIGH = new ItemMetaKey("UUIDMost");
     @Specific(Specific.To.NBT)
     static final ItemMetaKey ATTRIBUTES_UUID_LOW = new ItemMetaKey("UUIDLeast");
+    @Specific(Specific.To.NBT)
+    static final ItemMetaKey BLOCK_ENTITY_TAG = new ItemMetaKey("BlockEntityTag");
 
     private String displayName;
     private List<String> lore;
     private Map<Enchantment, Integer> enchantments;
     private int repairCost;
     private final NBTTagList attributes;
+    private final NBTTagCompound blockEntityTag;
 
     CraftMetaItem(CraftMetaItem meta) {
         if (meta == null) {
             attributes = null;
+            blockEntityTag = null;
             return;
         }
 
@@ -221,6 +225,7 @@ class CraftMetaItem implements ItemMeta, Repairable {
 
         this.repairCost = meta.repairCost;
         this.attributes = meta.attributes;
+        blockEntityTag = meta.blockEntityTag;
     }
 
     CraftMetaItem(NBTTagCompound tag) {
@@ -296,6 +301,12 @@ class CraftMetaItem implements ItemMeta, Repairable {
         } else {
             attributes = null;
         }
+        
+        if (tag.hasKeyOfType(BLOCK_ENTITY_TAG.NBT, 10)) {
+            blockEntityTag = tag.getCompound(BLOCK_ENTITY_TAG.NBT);
+        } else {
+            blockEntityTag = null;
+        }
     }
 
     static Map<Enchantment, Integer> buildEnchantments(NBTTagCompound tag, ItemMetaKey key) {
@@ -332,6 +343,7 @@ class CraftMetaItem implements ItemMeta, Repairable {
         }
 
         attributes = null;
+        blockEntityTag = null;
     }
 
     static Map<Enchantment, Integer> buildEnchantments(Map<String, Object> map, ItemMetaKey key) {
@@ -371,6 +383,10 @@ class CraftMetaItem implements ItemMeta, Repairable {
         if (attributes != null) {
             itemTag.set(ATTRIBUTES.NBT, attributes);
         }
+        
+        if (blockEntityTag != null) {
+            itemTag.set(BLOCK_ENTITY_TAG.NBT, blockEntityTag);
+        }
     }
 
     static NBTTagList createStringList(List<String> list) {
@@ -539,7 +555,8 @@ class CraftMetaItem implements ItemMeta, Repairable {
                 && (this.hasEnchants() ? that.hasEnchants() && this.enchantments.equals(that.enchantments) : !that.hasEnchants())
                 && (this.hasLore() ? that.hasLore() && this.lore.equals(that.lore) : !that.hasLore())
                 && (this.hasAttributes() ? that.hasAttributes() && this.attributes.equals(that.attributes) : !that.hasAttributes())
-                && (this.hasRepairCost() ? that.hasRepairCost() && this.repairCost == that.repairCost : !that.hasRepairCost());
+                && (this.hasRepairCost() ? that.hasRepairCost() && this.repairCost == that.repairCost : !that.hasRepairCost())
+                && (this.blockEntityTag != null ? that.blockEntityTag != null && this.blockEntityTag.equals(this.blockEntityTag) : that.blockEntityTag == null);
     }
 
     /**