Scissors/patches/server/0021-Reject-oversized-components-from-updating.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Video <videogamesm12@gmail.com>
Date: Mon, 28 Mar 2022 16:49:17 -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 8f4c83837d0b01a3dbca2607ea718c371db48ef4..fe2717679f84fbef1b8ff1f9a3c3bf0fba8965f1 100644
--- a/src/main/java/net/minecraft/network/chat/ComponentUtils.java
+++ b/src/main/java/net/minecraft/network/chat/ComponentUtils.java
@@ -37,8 +37,11 @@ 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 {
             MutableComponent mutableComponent = text instanceof ContextAwareComponent ? ((ContextAwareComponent)text).resolve(source, sender, depth + 1) : text.plainCopy();
 
@@ -46,8 +49,12 @@ 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 ? new TextComponent("") : result;
+        // Scissors end
     }
 
     private static Style resolveStyle(@Nullable CommandSourceStack source, Style style, @Nullable Entity sender, int depth) throws CommandSyntaxException {