From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: LemonCaramel <admin@caramel.moe>
Date: Sun, 24 Sep 2023 20:19:44 +0900
Subject: [PATCH] Fix UnsafeValues#loadAdvancement


diff --git a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
index 1cdcd673e67090b6ba3ec7b38bd062c0d8f7308a..509f8487a170f3dc84b091acf16df26e42391189 100644
--- a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
@@ -316,7 +316,27 @@ public final class CraftMagicNumbers implements UnsafeValues {
         JsonElement jsonelement = ServerAdvancementManager.GSON.fromJson(advancement, JsonElement.class);
         net.minecraft.advancements.Advancement nms = Util.getOrThrow(net.minecraft.advancements.Advancement.CODEC.parse(JsonOps.INSTANCE, jsonelement), JsonParseException::new);
         if (nms != null) {
-            MinecraftServer.getServer().getAdvancements().advancements.put(minecraftkey, new AdvancementHolder(minecraftkey, nms));
+            // Paper start - Fix throw UnsupportedOperationException
+            //MinecraftServer.getServer().getAdvancements().advancements.put(minecraftkey, new AdvancementHolder(minecraftkey, nms));
+            final com.google.common.collect.ImmutableMap.Builder<ResourceLocation, AdvancementHolder> mapBuilder = com.google.common.collect.ImmutableMap.builder();
+            mapBuilder.putAll(MinecraftServer.getServer().getAdvancements().advancements);
+
+            final AdvancementHolder holder = new AdvancementHolder(minecraftkey, nms);
+            mapBuilder.put(minecraftkey, holder);
+
+            MinecraftServer.getServer().getAdvancements().advancements = mapBuilder.build();
+            final net.minecraft.advancements.AdvancementTree tree = MinecraftServer.getServer().getAdvancements().tree();
+            tree.addAll(List.of(holder));
+
+            // recalculate advancement position
+            final net.minecraft.advancements.AdvancementNode node = tree.get(minecraftkey);
+            if (node != null) {
+                final net.minecraft.advancements.AdvancementNode root = node.root();
+                if (root.holder().value().display().isPresent()) {
+                    net.minecraft.advancements.TreeNodePosition.run(root);
+                }
+            }
+            // Paper end - Fix throw UnsupportedOperationException
             Advancement bukkit = Bukkit.getAdvancement(key);
 
             if (bukkit != null) {