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 07593ecae8fb00412c5342681263e3333d3809c0..42ea3573c0e8559a264fd24fc09c3a5cd7628d9b 100644
--- a/src/main/java/net/minecraft/nbt/CompoundTag.java
+++ b/src/main/java/net/minecraft/nbt/CompoundTag.java
@@ -194,6 +194,12 @@ 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));
     }
 
@@ -202,10 +208,20 @@ 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 c0fe7c576f2361e599bc23003da7c49bb7cb62b2..846f8267f7d24f52b84314483c8230c620ef2dce 100644
--- a/src/main/java/net/minecraft/nbt/NbtUtils.java
+++ b/src/main/java/net/minecraft/nbt/NbtUtils.java
@@ -79,6 +79,11 @@ 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");
