PaperMC/Spigot-Server-Patches/0527-Support-old-UUID-format-for-NBT.patch

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/server/NBTTagCompound.java b/src/main/java/net/minecraft/server/NBTTagCompound.java
index f608b35502890650adfc1df35e0794471f57ecbc..74a8418b72f97a8956857a46fb06251602ad30e3 100644
--- a/src/main/java/net/minecraft/server/NBTTagCompound.java
+++ b/src/main/java/net/minecraft/server/NBTTagCompound.java
@@ -142,11 +142,21 @@ public class NBTTagCompound implements NBTBase {
     @Nullable public UUID getUUID(String prefix) { return a(prefix); } // Paper - OBFHELPER
     @Nullable
     public UUID a(String s) {
+        // Paper start - support old format
+        if (hasKey(s + "Least") && hasKey(s + "Most")) {
+            return new UUID(this.getLong(s + "Most"), this.getLong(s + "Least"));
+        }
+        // Paper end
         return GameProfileSerializer.a(this.get(s));
     }
 
     public final boolean hasUUID(String s) { return this.b(s); } // Paper - OBFHELPER
     public boolean b(String s) {
+        // Paper start - support old format
+        if (hasKey(s + "Least") && hasKey(s + "Most")) {
+            return true;
+        }
+        // Paper end
         NBTBase nbtbase = this.get(s);
 
         return nbtbase != null && nbtbase.b() == NBTTagIntArray.a && ((NBTTagIntArray) nbtbase).getInts().length == 4;