From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Thu, 3 Mar 2016 01:17:12 -0600
Subject: [PATCH] Improve Player chat API handling

Properly split up the chat and command handling to reflect the server now
having separate packets for both, and the client always using the correct packet. Text
from a chat packet should never be parsed into a command, even if it starts with the `/`
character.

Add a missing async catcher and improve Spigot's async catcher error message.

== AT ==
public net.minecraft.server.network.ServerGamePacketListenerImpl isChatMessageIllegal(Ljava/lang/String;)Z

Co-authored-by: Jake Potrebic <jake.m.potrebic@gmail.com>
Co-authored-by: SoSeDiK <mrsosedik@gmail.com>

diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
index b41351783ea9795afaddce453c82ab32cb8134a1..870a1d6679fa062d90bcfa1a21a8af0cf67f2950 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -1934,7 +1934,7 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
         }
         OutgoingChatMessage outgoing = OutgoingChatMessage.create(original);
 
-        if (!async && s.startsWith("/")) {
+        if (false && !async && s.startsWith("/")) { // Paper - Don't handle commands in chat logic
             this.handleCommand(s);
         } else if (this.player.getChatVisibility() == ChatVisiblity.SYSTEM) {
             // Do nothing, this is coming from a plugin
@@ -2018,7 +2018,8 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
         }
     }
 
-    private void handleCommand(String s) {
+    public void handleCommand(String s) { // Paper - private -> public
+        org.spigotmc.AsyncCatcher.catchOp("Command Dispatched Async: " + s); // Paper - Add async catcher
         co.aikar.timings.MinecraftTimings.playerCommandTimer.startTiming(); // Paper
         if ( org.spigotmc.SpigotConfig.logCommands ) // Spigot
         this.LOGGER.info(this.player.getScoreboardName() + " issued server command: " + s);
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index d491b3e7a6ec5ef2e2d7bf3fa014a4f501bff124..638d978d86ee324e2eddfebda02ae54572982935 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -885,7 +885,7 @@ public final class CraftServer implements Server {
     public boolean dispatchCommand(CommandSender sender, String commandLine) {
         Preconditions.checkArgument(sender != null, "sender cannot be null");
         Preconditions.checkArgument(commandLine != null, "commandLine cannot be null");
-        org.spigotmc.AsyncCatcher.catchOp("command dispatch"); // Spigot
+        org.spigotmc.AsyncCatcher.catchOp("Command Dispatched Async: " + commandLine); // Spigot // Paper - Include command in error message
 
         if (this.commandMap.dispatch(sender, commandLine)) {
             return true;
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index fc6557ad318209a3f1f617cec162740a1d26b051..4585c67495ffda7f149c4dbcf379839f40cf6bac 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -498,7 +498,20 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
         if (this.getHandle().connection == null) return;
 
-        this.getHandle().connection.chat(msg, PlayerChatMessage.system(msg), false);
+        // Paper start - Improve chat handling
+        if (ServerGamePacketListenerImpl.isChatMessageIllegal(msg)) {
+            this.getHandle().connection.disconnect(Component.translatable("multiplayer.disconnect.illegal_characters"));
+        } else {
+            if (msg.startsWith("/")) {
+                this.getHandle().connection.handleCommand(msg);
+            } else {
+                final PlayerChatMessage playerChatMessage = PlayerChatMessage.system(msg).withResult(new net.minecraft.network.chat.ChatDecorator.ModernResult(Component.literal(msg), true, false));
+                // TODO chat decorating
+                // TODO text filtering
+                this.getHandle().connection.chat(msg, playerChatMessage, false);
+            }
+        }
+        // Paper end
     }
 
     @Override