SPIGOT-5907: Item Frame NBT data disappears

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

@@ -259,6 +259,8 @@ public final class CraftItemFactory implements ItemFactory {
             return meta instanceof CraftMetaCrossbow ? meta : new CraftMetaCrossbow(meta);
         case SUSPICIOUS_STEW:
             return meta instanceof CraftMetaSuspiciousStew ? meta : new CraftMetaSuspiciousStew(meta);
+        case ITEM_FRAME:
+            return meta instanceof CraftMetaEntityTag ? meta : new CraftMetaEntityTag(meta);
         default:
             return new CraftMetaItem(meta);
         }

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

@@ -528,6 +528,8 @@ public final class CraftItemStack extends ItemStack {
                 return new CraftMetaCrossbow(item.getTag());
             case SUSPICIOUS_STEW:
                 return new CraftMetaSuspiciousStew(item.getTag());
+            case ITEM_FRAME:
+                return new CraftMetaEntityTag(item.getTag());
             default:
                 return new CraftMetaItem(item.getTag());
         }

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

@@ -0,0 +1,123 @@
+package org.bukkit.craftbukkit.inventory;
+
+import com.google.common.collect.ImmutableMap.Builder;
+import java.util.Map;
+import net.minecraft.server.NBTBase;
+import net.minecraft.server.NBTTagCompound;
+import org.bukkit.Material;
+import org.bukkit.configuration.serialization.DelegateDeserialization;
+
+@DelegateDeserialization(CraftMetaItem.SerializableMeta.class)
+public class CraftMetaEntityTag extends CraftMetaItem {
+
+    static final ItemMetaKey ENTITY_TAG = new ItemMetaKey("EntityTag", "entity-tag");
+    NBTTagCompound entityTag;
+
+    CraftMetaEntityTag(CraftMetaItem meta) {
+        super(meta);
+    }
+
+    CraftMetaEntityTag(NBTTagCompound tag) {
+        super(tag);
+
+        if (tag.hasKey(ENTITY_TAG.NBT)) {
+            entityTag = tag.getCompound(ENTITY_TAG.NBT);
+        }
+    }
+
+    CraftMetaEntityTag(Map<String, Object> map) {
+        super(map);
+    }
+
+    @Override
+    void deserializeInternal(NBTTagCompound tag, Object context) {
+        super.deserializeInternal(tag, context);
+
+        if (tag.hasKey(ENTITY_TAG.NBT)) {
+            entityTag = tag.getCompound(ENTITY_TAG.NBT);
+        }
+    }
+
+    @Override
+    void serializeInternal(Map<String, NBTBase> internalTags) {
+        if (entityTag != null && !entityTag.isEmpty()) {
+            internalTags.put(ENTITY_TAG.NBT, entityTag);
+        }
+    }
+
+    @Override
+    void applyToItem(NBTTagCompound tag) {
+        super.applyToItem(tag);
+
+        if (entityTag != null) {
+            tag.set(ENTITY_TAG.NBT, entityTag);
+        }
+    }
+
+    @Override
+    boolean applicableTo(Material type) {
+        switch (type) {
+            case ITEM_FRAME:
+                return true;
+            default:
+                return false;
+        }
+    }
+
+    @Override
+    boolean isEmpty() {
+        return super.isEmpty() && isEntityTagEmpty();
+    }
+
+    boolean isEntityTagEmpty() {
+        return !(entityTag != null);
+    }
+
+    @Override
+    boolean equalsCommon(CraftMetaItem meta) {
+        if (!super.equalsCommon(meta)) {
+            return false;
+        }
+        if (meta instanceof CraftMetaEntityTag) {
+            CraftMetaEntityTag that = (CraftMetaEntityTag) meta;
+
+            return entityTag != null ? that.entityTag != null && this.entityTag.equals(that.entityTag) : entityTag == null;
+        }
+        return true;
+    }
+
+    @Override
+    boolean notUncommon(CraftMetaItem meta) {
+        return super.notUncommon(meta) && (meta instanceof CraftMetaEntityTag || isEntityTagEmpty());
+    }
+
+    @Override
+    int applyHash() {
+        final int original;
+        int hash = original = super.applyHash();
+
+        if (entityTag != null) {
+            hash = 73 * hash + entityTag.hashCode();
+        }
+
+        return original != hash ? CraftMetaEntityTag.class.hashCode() ^ hash : hash;
+    }
+
+    @Override
+    Builder<String, Object> serialize(Builder<String, Object> builder) {
+        super.serialize(builder);
+
+        return builder;
+    }
+
+    @Override
+    public CraftMetaEntityTag clone() {
+        CraftMetaEntityTag clone = (CraftMetaEntityTag) super.clone();
+
+        if (entityTag != null) {
+            clone.entityTag = entityTag.clone();
+        }
+
+        return clone;
+    }
+}

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

@@ -155,6 +155,7 @@ class CraftMetaItem implements ItemMeta, Damageable, Repairable, BlockDataMeta {
                     .put(CraftMetaTropicalFishBucket.class, "TROPICAL_FISH_BUCKET")
                     .put(CraftMetaCrossbow.class, "CROSSBOW")
                     .put(CraftMetaSuspiciousStew.class, "SUSPICIOUS_STEW")
+                    .put(CraftMetaEntityTag.class, "ENTITY_TAG")
                     .put(CraftMetaItem.class, "UNSPECIFIC")
                     .build();
 

src/test/java/org/bukkit/craftbukkit/inventory/ItemMetaTest.java

@@ -324,6 +324,15 @@ public class ItemMetaTest extends AbstractTestingBase {
                     cleanStack.setItemMeta(meta);
                     return cleanStack;
                 }
+            },
+            new StackProvider(Material.ITEM_FRAME) {
+                @Override ItemStack operate(ItemStack cleanStack) {
+                    final CraftMetaEntityTag meta = ((CraftMetaEntityTag) cleanStack.getItemMeta());
+                    meta.entityTag = new NBTTagCompound();
+                    meta.entityTag.setBoolean("Invisible", true);
+                    cleanStack.setItemMeta(meta);
+                    return cleanStack;
+                }
             }
         );