From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Thu, 8 Oct 2020 00:00:25 -0400
Subject: [PATCH] Fix "Not a string" Map Conversion spam

The maps did convert successfully, but had noisy logs due to Spigot
implementing this logic incorrectly.

This stops the spam by converting the old format to new before
requesting the world.

diff --git a/src/main/java/net/minecraft/world/level/saveddata/maps/WorldMap.java b/src/main/java/net/minecraft/world/level/saveddata/maps/WorldMap.java
index d470af1814af332595c1c0beb1cdc552e186a6bb..3b6872af2a3e3ab45b0036e2d64009b2f3882d20 100644
--- a/src/main/java/net/minecraft/world/level/saveddata/maps/WorldMap.java
+++ b/src/main/java/net/minecraft/world/level/saveddata/maps/WorldMap.java
@@ -94,7 +94,26 @@ public class WorldMap extends PersistentBase {
 
     @Override
     public void a(NBTTagCompound nbttagcompound) {
-        DataResult<ResourceKey<World>> dataresult = DimensionManager.a(new Dynamic(DynamicOpsNBT.a, nbttagcompound.get("dimension"))); // CraftBukkit - decompile error
+        // Paper start - fix "Not a string" spam
+        NBTBase dimension = nbttagcompound.get("dimension");
+        if (dimension instanceof NBTNumber && ((NBTNumber) dimension).asInt() >= CraftWorld.CUSTOM_DIMENSION_OFFSET) {
+            long least = nbttagcompound.getLong("UUIDLeast");
+            long most = nbttagcompound.getLong("UUIDMost");
+
+            if (least != 0L && most != 0L) {
+                this.uniqueId = new UUID(most, least);
+                CraftWorld world = (CraftWorld) server.getWorld(this.uniqueId);
+                if (world != null) {
+                    dimension = NBTTagString.create("minecaft:" + world.getName().toLowerCase(java.util.Locale.ENGLISH));
+                } else {
+                    dimension = NBTTagString.create("bukkit:_invalidworld_");
+                }
+            } else {
+                dimension = NBTTagString.create("bukkit:_invalidworld_");
+            }
+        }
+        DataResult<ResourceKey<World>> dataresult = DimensionManager.a(new Dynamic(DynamicOpsNBT.a, dimension)); // CraftBukkit - decompile error
+        // Paper end - fix "Not a string" spam
         Logger logger = WorldMap.LOGGER;
 
         logger.getClass();