Scissors/patches/server/0028-Reject-oversized-components-from-updating.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Telesphoreo <me@telesphoreo.me>
Date: Fri, 25 Nov 2022 22:25:24 -0600
Subject: [PATCH] Reject oversized components from updating


diff --git a/src/main/java/net/minecraft/network/chat/ComponentUtils.java b/src/main/java/net/minecraft/network/chat/ComponentUtils.java
index 9d0d5a44c5948bde037165147d18aaabe21ce50a..c42b8b4daa1ffa6f3ae89b35056edbf61ae47283 100644
--- a/src/main/java/net/minecraft/network/chat/ComponentUtils.java
+++ b/src/main/java/net/minecraft/network/chat/ComponentUtils.java
@@ -39,8 +39,10 @@ public class ComponentUtils {
     }
 
     public static MutableComponent updateForEntity(@Nullable CommandSourceStack source, Component text, @Nullable Entity sender, int depth) throws CommandSyntaxException {
+        // Scissors start - Reject oversized components
+        MutableComponent result;
         if (depth > 100) {
-            return text.copy();
+            result = text.copy();
         } else {
             // Paper start
             if (text instanceof io.papermc.paper.adventure.AdventureComponent adventureComponent) {
@@ -53,8 +55,11 @@ public class ComponentUtils {
                 mutableComponent.append(updateForEntity(source, component, sender, depth + 1));
             }
 
-            return mutableComponent.withStyle(resolveStyle(source, text.getStyle(), sender, depth));
+            result = mutableComponent.withStyle(resolveStyle(source, text.getStyle(), sender, depth));
         }
+        // Would the resulting component exceed 65535 bytes when encoded as a string?
+        return Component.Serializer.toJson(result).length() > 65535 ? Component.empty() : result;
+        // Scissors end
     }
 
     private static Style resolveStyle(@Nullable CommandSourceStack source, Style style, @Nullable Entity sender, int depth) throws CommandSyntaxException {