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 1d13bc15c56faa69699fb3ad39210233d6b6934d..7e94ebe06fc62293e665d6db19e42d947e7eb30f 100644
--- a/src/main/java/net/minecraft/nbt/CompoundTag.java
+++ b/src/main/java/net/minecraft/nbt/CompoundTag.java
@@ -196,6 +196,12 @@ 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));
     }
 
@@ -204,10 +210,20 @@ 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 1e7ba8d82269d2d375b2f2d3fc21ed922cce0942..7bc60901297d27d88efb401d02b4bc06d8b28874 100644
--- a/src/main/java/net/minecraft/nbt/NbtUtils.java
+++ b/src/main/java/net/minecraft/nbt/NbtUtils.java
@@ -76,6 +76,11 @@ public final class NbtUtils {
         if (nbt.contains("Name", 8)) {
             string = nbt.getString("Name");
         }
+        // Paper start - support string UUID's
+        if (nbt.contains("Id", 8)) {
+            uUID = UUID.fromString(nbt.getString("Id"));
+        }
+        // Paper end
 
         if (nbt.hasUUID("Id")) {
             uUID = nbt.getUUID("Id");