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 c856ca720a9329a94bb07eaa3060c034f95718b3..0b739b5f040697049893d311c99456dbc5470e93 100644
--- a/src/main/java/net/minecraft/nbt/CompoundTag.java
+++ b/src/main/java/net/minecraft/nbt/CompoundTag.java
@@ -142,6 +142,12 @@ public class CompoundTag implements Tag {
 
     public void setUUID(String prefix, UUID uuid) { putUUID(prefix, uuid); } // Paper - OBFHELPER
     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));
     }
 
@@ -151,11 +157,21 @@ public class CompoundTag implements Tag {
      */
     public UUID getUUID(String prefix) { return getUUID(prefix); } // Paper - OBFHELPER
     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 final boolean hasUUID(String s) { return this.hasUUID(s); } // Paper - OBFHELPER
     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 nbtbase = this.get(key);
 
         return nbtbase != null && nbtbase.getType() == IntArrayTag.TYPE && ((IntArrayTag) nbtbase).getAsIntArray().length == 4;
diff --git a/src/main/java/net/minecraft/nbt/NbtUtils.java b/src/main/java/net/minecraft/nbt/NbtUtils.java
index bf0da04ec9db3ec8313bddb06c278c13073819d1..f57c5e441045a81072a2edfed0f199d90e6d7fde 100644
--- a/src/main/java/net/minecraft/nbt/NbtUtils.java
+++ b/src/main/java/net/minecraft/nbt/NbtUtils.java
@@ -40,6 +40,11 @@ public final class NbtUtils {
             s = tag.getString("Name");
         }
 
+        // Paper start - support string UUID's
+        if (tag.contains("Id", 8)) {
+            uuid = UUID.fromString(tag.getString("Id"));
+        }
+        // Paper end
         if (tag.hasUUID("Id")) {
             uuid = tag.getUUID("Id");
         }