From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Mon, 29 Jun 2020 03:26:17 -0400
Subject: [PATCH] Support old UUID format for NBT

We have stored UUID in plenty of places that did not get DFU'd

So just look for old format and load it if it exists.

diff --git a/src/main/java/net/minecraft/nbt/CompoundTag.java b/src/main/java/net/minecraft/nbt/CompoundTag.java
index 0778fdd4f47015787f7ffbfb39c31ec0e1c039bd..912fd5135e89348bdd3c0a8b6c07860ebc106df3 100644
--- a/src/main/java/net/minecraft/nbt/CompoundTag.java
+++ b/src/main/java/net/minecraft/nbt/CompoundTag.java
@@ -181,6 +181,12 @@ public class CompoundTag implements Tag {
     }
 
     public void putUUID(String key, UUID value) {
+        // Paper start - support old format
+        if (this.contains(key + "Most", 99) && this.contains(key + "Least", 99)) {
+            this.tags.remove(key + "Most");
+            this.tags.remove(key + "Least");
+        }
+        // Paper end
         this.tags.put(key, NbtUtils.createUUID(value));
     }
 
@@ -189,10 +195,20 @@ public class CompoundTag implements Tag {
      * You must use {@link #hasUUID(String)} before or else it <b>will</b> throw an NPE.
      */
     public UUID getUUID(String key) {
+        // Paper start - support old format
+        if (!contains(key, 11) && this.contains(key + "Most", 99) && this.contains(key + "Least", 99)) {
+            return new UUID(this.getLong(key + "Most"), this.getLong(key + "Least"));
+        }
+        // Paper end
         return NbtUtils.loadUUID(this.get(key));
     }
 
     public boolean hasUUID(String key) {
+        // Paper start - support old format
+        if (this.contains(key + "Most", 99) && this.contains(key + "Least", 99)) {
+            return true;
+        }
+        // Paper end
         Tag tag = this.get(key);
         return tag != null && tag.getType() == IntArrayTag.TYPE && ((IntArrayTag)tag).getAsIntArray().length == 4;
     }
diff --git a/src/main/java/net/minecraft/nbt/NbtUtils.java b/src/main/java/net/minecraft/nbt/NbtUtils.java
index d6a742066b2e5ebf3975c190cca5134abf3cf1a3..fdf78f7ab15a8c81699c6c0e5d0333c482c7d0a3 100644
--- a/src/main/java/net/minecraft/nbt/NbtUtils.java
+++ b/src/main/java/net/minecraft/nbt/NbtUtils.java
@@ -74,6 +74,11 @@ public final class NbtUtils {
         if (compound.contains("Name", 8)) {
             string = compound.getString("Name");
         }
+        // Paper start - support string UUID's
+        if (compound.contains("Id", 8)) {
+            uUID = UUID.fromString(compound.getString("Id"));
+        }
+        // Paper end
 
         if (compound.hasUUID("Id")) {
             uUID = compound.getUUID("Id");