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 2c922afde237ca0e56ee6dc067f2989434d4d08c..a4f0cb93a08136888a81f1a8e7ed1d56f92e2195 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -2063,7 +2063,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Tic
         }
         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
@@ -2147,7 +2147,8 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Tic
         }
     }
 
-    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 66433478fd82f730705fd383b90145d79189a915..fd9457a02f36b0230eb2d4fd549419f46d4b8da3 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -886,7 +886,7 @@ 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 f5b05eb97f059cfb4d6d22d0a180c5fd8a203f66..a3f85b1cf8b03da90f2461cbe42dd18a630f2255 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -492,7 +492,20 @@ 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