From 3c04da9ae9eabb5fa6e86d8011dff6b4adfc347e Mon Sep 17 00:00:00 2001
From: TheMode <themode@outlook.fr>
Date: Fri, 25 Jun 2021 19:10:41 +0200
Subject: [PATCH] Add dummy block handler

---
 .../minestom/server/instance/AnvilLoader.java |  6 ++---
 .../server/instance/block/BlockHandler.java   | 26 +++++++++++++++++++
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/src/main/java/net/minestom/server/instance/AnvilLoader.java b/src/main/java/net/minestom/server/instance/AnvilLoader.java
index 62822e128..0d0122fe9 100644
--- a/src/main/java/net/minestom/server/instance/AnvilLoader.java
+++ b/src/main/java/net/minestom/server/instance/AnvilLoader.java
@@ -154,10 +154,10 @@ public class AnvilLoader implements IChunkLoader {
 
             final String tileEntityID = te.getString("id");
             if (tileEntityID != null) {
-                final var handler = BLOCK_MANAGER.getHandler(tileEntityID);
+                var handler = BLOCK_MANAGER.getHandler(tileEntityID);
                 if (handler == null) {
-                    LOGGER.warn("Block {} does not have any corresponding handler, world will load anyway.", tileEntityID);
-                    continue;
+                    LOGGER.warn("Block {} does not have any corresponding handler, default to dummy.", tileEntityID);
+                    handler = BlockHandler.Dummy.get(tileEntityID);
                 }
                 block = block.withHandler(handler);
             }
diff --git a/src/main/java/net/minestom/server/instance/block/BlockHandler.java b/src/main/java/net/minestom/server/instance/block/BlockHandler.java
index 3ce43800f..8c80ba674 100644
--- a/src/main/java/net/minestom/server/instance/block/BlockHandler.java
+++ b/src/main/java/net/minestom/server/instance/block/BlockHandler.java
@@ -11,6 +11,8 @@ import org.jetbrains.annotations.NotNull;
 
 import java.util.Collection;
 import java.util.Collections;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 /**
  * Interface used to provide block behavior. Set with {@link Block#withHandler(BlockHandler)}.
@@ -282,4 +284,28 @@ public interface BlockHandler {
             return blockPosition;
         }
     }
+
+    /**
+     * Handler used for loaded blocks with unknown namespace
+     * in order to do not lose the information while saving, and for runtime debugging purpose.
+     */
+    class Dummy implements BlockHandler {
+        private static final Map<String, BlockHandler> DUMMY_CACHE = new ConcurrentHashMap<>();
+
+        @ApiStatus.Internal
+        public static @NotNull BlockHandler get(@NotNull String namespace) {
+            return DUMMY_CACHE.computeIfAbsent(namespace, s -> new Dummy(NamespaceID.from(namespace)));
+        }
+
+        private final NamespaceID namespaceID;
+
+        private Dummy(NamespaceID namespaceID) {
+            this.namespaceID = namespaceID;
+        }
+
+        @Override
+        public @NotNull NamespaceID getNamespaceId() {
+            return namespaceID;
+        }
+    }
 }