From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Thu, 16 Jun 2022 14:22:56 -0700
Subject: [PATCH] Don't broadcast messages to command blocks

Previously the broadcast method would update the last output
in command blocks, and if called asynchronously, would throw
an error

diff --git a/src/main/java/net/minecraft/world/level/BaseCommandBlock.java b/src/main/java/net/minecraft/world/level/BaseCommandBlock.java
index 7c7e5f3c0f9cd1f16192a8fc8163da9b2d9519d5..888936385196a178ab8b730fd5e4fff4a5466428 100644
--- a/src/main/java/net/minecraft/world/level/BaseCommandBlock.java
+++ b/src/main/java/net/minecraft/world/level/BaseCommandBlock.java
@@ -172,6 +172,7 @@ public abstract class BaseCommandBlock implements CommandSource {
     @Override
     public void sendSystemMessage(Component message) {
         if (this.trackOutput) {
+            org.spigotmc.AsyncCatcher.catchOp("sendSystemMessage to a command block"); // Paper
             SimpleDateFormat simpledateformat = BaseCommandBlock.TIME_FORMAT;
             Date date = new Date();
 
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index aa713ea0a44f578b80e194353519ec24a8a0c8f8..a940aead1076b44d8da1d5b84da8b297a0ebab8e 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -1790,7 +1790,7 @@ public final class CraftServer implements Server {
         // Paper end
         Set<CommandSender> recipients = new HashSet<>();
         for (Permissible permissible : this.getPluginManager().getPermissionSubscriptions(permission)) {
-            if (permissible instanceof CommandSender && permissible.hasPermission(permission)) {
+            if (permissible instanceof CommandSender && !(permissible instanceof org.bukkit.command.BlockCommandSender) && permissible.hasPermission(permission)) { // Paper - don't broadcast to BlockCommandSender (specifically Command Blocks)
                 recipients.add((CommandSender) permissible);
             }
         }