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 984da6264cdaf57a49a15861b9ce834a9efac1a7..df616dbe37b8a2068338f071300d6315a361a075 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
@@ -15,6 +15,8 @@ import net.minecraft.core.BlockPos;
 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.chat.Component;
 import net.minecraft.network.protocol.Packet;
@@ -103,7 +105,26 @@ public class MapItemSavedData extends SavedData {
     }
 
     public static MapItemSavedData load(CompoundTag nbt) {
-        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);