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 d6d8adf1e49cdb74dc5d8e2e60bcaca7c5e1c16d..b31741a9c3363e4288636ceff9b38c598a84aa43 100644
--- a/src/main/java/net/minecraft/nbt/NbtUtils.java
+++ b/src/main/java/net/minecraft/nbt/NbtUtils.java
@@ -75,6 +75,11 @@ 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");
