PaperMC/patches/server/0055-Improve-Player-chat-API-handling.patch

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 3a67b2b6a6d3204b2a7bbe8adbf2b0ecf7898551..02b9e1ed57f5d65698c461387ff7d48450e6a70f 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -2013,7 +2013,7 @@ 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
@@ -2100,7 +2100,8 @@ 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 8f79d7611c3ee1c817d5671152e459ec4f413418..441a8d3355e0db773a5da330bf9361234da1ca89 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -934,7 +934,7 @@ 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 545da59af2436b9a4363ec459456c8f15650b79f..9751cace64d9ad2b8b55080b13834e8ccb056b42 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -546,7 +546,20 @@ 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).withUnsignedContent(Component.literal(msg));
+                // TODO chat decorating
+                // TODO text filtering
+                this.getHandle().connection.chat(msg, playerChatMessage, false);
+            }
+        }
+        // Paper end - Improve chat handling
     }
 
     @Override