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
1.17 Update: See if this is still needed, might be fixed upstream
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/MapItemSavedData.java b/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java
index 7582c7cd4235d212a0cf66a4c59ce0cedaa360ad..e7b178127228dea5a17ba0fbd6bae148d70e8eb5 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
@@ -12,6 +12,8 @@ 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;
@@ -94,7 +96,26 @@ public class MapItemSavedData extends SavedData {
 
     @Override
     public void load(CompoundTag tag) {
-        DataResult<ResourceKey<Level>> dataresult = DimensionType.parseLegacy(new Dynamic(NbtOps.INSTANCE, tag.get("dimension"))); // CraftBukkit - decompile error
+        // Paper start - fix "Not a string" spam
+        Tag dimension = tag.get("dimension");
+        if (dimension instanceof NumericTag && ((NumericTag) dimension).getAsInt() >= CraftWorld.CUSTOM_DIMENSION_OFFSET) {
+            long least = tag.getLong("UUIDLeast");
+            long most = tag.getLong("UUIDMost");
+
+            if (least != 0L && most != 0L) {
+                this.uniqueId = new UUID(most, least);
+                CraftWorld world = (CraftWorld) server.getWorld(this.uniqueId);
+                if (world != null) {
+                    dimension = StringTag.create("minecraft:" + world.getName().toLowerCase(java.util.Locale.ENGLISH));
+                } else {
+                    dimension = StringTag.create("bukkit:_invalidworld_");
+                }
+            } else {
+                dimension = StringTag.create("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;
 
         logger.getClass();