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.

Track spigot issue to see when fixed: https://hub.spigotmc.org/jira/browse/SPIGOT-6181

diff --git a/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java b/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java
index d42d39dff5aeb91c5b1e6a7fb967ce70f1a88b7e..38c0855a6f9398f8d075f304288cf9e9f695770a 100644
--- a/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java
+++ b/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java
@@ -21,6 +21,8 @@ import net.minecraft.core.component.DataComponents;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.nbt.ListTag;
 import net.minecraft.nbt.NbtOps;
+import net.minecraft.nbt.NumericTag;
+import net.minecraft.nbt.StringTag;
 import net.minecraft.nbt.Tag;
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.network.chat.Component;
@@ -120,7 +122,26 @@ public class MapItemSavedData extends SavedData {
     }
 
     public static MapItemSavedData load(CompoundTag nbt, HolderLookup.Provider registryLookup) {
-        DataResult<ResourceKey<Level>> dataresult = DimensionType.parseLegacy(new Dynamic(NbtOps.INSTANCE, nbt.get("dimension"))); // CraftBukkit - decompile error
+        // Paper start - fix "Not a string" spam
+        Tag dimension = nbt.get("dimension");
+        if (dimension instanceof NumericTag && ((NumericTag) dimension).getAsInt() >= CraftWorld.CUSTOM_DIMENSION_OFFSET) {
+            long least = nbt.getLong("UUIDLeast");
+            long most = nbt.getLong("UUIDMost");
+
+            if (least != 0L && most != 0L) {
+                UUID uuid = new UUID(most, least);
+                CraftWorld world = (CraftWorld) Bukkit.getWorld(uuid);
+                if (world != null) {
+                    dimension = StringTag.valueOf("minecraft:" + world.getName().toLowerCase(java.util.Locale.ENGLISH));
+                } else {
+                    dimension = StringTag.valueOf("bukkit:_invalidworld_");
+                }
+            } else {
+                dimension = StringTag.valueOf("bukkit:_invalidworld_");
+            }
+        }
+        DataResult<ResourceKey<Level>> dataresult = DimensionType.parseLegacy(new Dynamic(NbtOps.INSTANCE, dimension)); // CraftBukkit - decompile error
+        // Paper end - fix "Not a string" spam
         Logger logger = MapItemSavedData.LOGGER;
 
         Objects.requireNonNull(logger);