Deep clone nbt tags in PDC

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java

@@ -376,7 +376,7 @@ class CraftMetaItem implements ItemMeta, Damageable, Repairable, BlockDataMeta {
         this.maxDamage = meta.maxDamage;
         this.unhandledTags.copy(meta.unhandledTags.build());
         this.removedTags.addAll(meta.removedTags);
-        this.persistentDataContainer.putAll(meta.persistentDataContainer.getRaw());
+        this.persistentDataContainer.putAll(meta.persistentDataContainer.getTagsCloned()); // Paper - deep clone NBT tags
 
         this.customTag = meta.customTag;
 
@@ -1987,7 +1987,7 @@ class CraftMetaItem implements ItemMeta, Damageable, Repairable, BlockDataMeta {
                 clone.customTag = this.customTag.copy();
             }
             clone.removedTags = Sets.newHashSet(this.removedTags);
-            clone.persistentDataContainer = new CraftPersistentDataContainer(this.persistentDataContainer.getRaw(), CraftMetaItem.DATA_TYPE_REGISTRY);
+            clone.persistentDataContainer = new CraftPersistentDataContainer(this.persistentDataContainer.getTagsCloned(), CraftMetaItem.DATA_TYPE_REGISTRY); // Paper - deep clone NBT tags
             clone.hideFlag = this.hideFlag;
             clone.hideTooltip = this.hideTooltip;
             clone.tooltipStyle = this.tooltipStyle;

paper-server/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataContainer.java

@@ -207,4 +207,12 @@ public class CraftPersistentDataContainer implements PersistentDataContainer {
         }
     }
     // Paper end - byte array serialization
+
+    // Paper start - deep clone tags
+    public Map<String, Tag> getTagsCloned() {
+        final Map<String, Tag> tags = new HashMap<>();
+        this.customDataTags.forEach((key, tag) -> tags.put(key, tag.copy()));
+        return tags;
+    }
+    // Paper end - deep clone tags
 }