Scissors/patches/server/0047-Reject-translatable-components-with-more-than-32-pla.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: VideoGameSmash12 <videogamesm12@gmail.com>
Date: Wed, 19 Oct 2022 00:50:29 -0600
Subject: [PATCH] Reject translatable components with more than 32 placeholders
 in them


diff --git a/src/main/java/net/minecraft/network/chat/Component.java b/src/main/java/net/minecraft/network/chat/Component.java
index 6978d14c6bd90ffb640e39e8666430d95d5ef45c..e6d733fc3a4acdb3fd91b5644285854943a02761 100644
--- a/src/main/java/net/minecraft/network/chat/Component.java
+++ b/src/main/java/net/minecraft/network/chat/Component.java
@@ -33,6 +33,9 @@ import net.minecraft.util.GsonHelper;
 import net.minecraft.util.LowerCaseEnumTypeAdapterFactory;
 // CraftBukkit start
 import com.google.common.collect.Streams;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 import java.util.stream.Stream;
 // CraftBukkit end
 
@@ -192,9 +195,53 @@ public interface Component extends Message, FormattedText, Iterable<Component> {
                 throw new IllegalStateException("Couldn't get field 'lineStart' for JsonReader", nosuchfieldexception);
             }
         });
+        private static final Pattern PLACEHOLDER_PATTERN = Pattern.compile("%[0-9]{1,}\\$s");
 
         public Serializer() {}
 
+        // Scissors start - Calculate number of placeholders in translatable components before serializing them
+        private long calculatePlaceholderCount(JsonElement element) {
+            long amount = 0;
+
+            if (!element.isJsonObject()) {
+                return amount;
+            }
+
+            JsonObject from = element.getAsJsonObject();
+
+            // Figure out how many placeholders are in a single translatable component
+            if (from.has("translate") && from.get("translate").isJsonPrimitive()) {
+                String key = GsonHelper.getAsString(from, "translate");
+                Matcher matcher = PLACEHOLDER_PATTERN.matcher(key);
+                amount += matcher.results().count();
+
+                // Recursively figure out how many placeholders the component has in the "with" shit
+                if (from.has("with") && from.get("with").isJsonArray()) {
+                    JsonArray array = GsonHelper.getAsJsonArray(from, "with");
+
+                    for (JsonElement within : array) {
+                        long amountWithin = calculatePlaceholderCount(within);
+
+                        if (amountWithin == 1) {
+                            amount++;
+                        }
+                        else if (amountWithin > 1) {
+                            amount = amount * amountWithin;
+                        }
+                    }
+                }
+            }
+            // Also applies to keybind components, but to a lesser extent
+            else if (from.has("keybind") && from.get("keybind").isJsonPrimitive()) {
+                String key = GsonHelper.getAsString(from, "keybind");
+                Matcher matcher = PLACEHOLDER_PATTERN.matcher(key);
+                amount += matcher.results().count();
+            }
+
+            return amount;
+        }
+        // Scissors end
+
         public MutableComponent deserialize(JsonElement jsonelement, Type type, JsonDeserializationContext jsondeserializationcontext) throws JsonParseException {
             if (jsonelement.isJsonPrimitive()) {
                 return new TextComponent(jsonelement.getAsString());
@@ -221,6 +268,13 @@ public interface Component extends Message, FormattedText, Iterable<Component> {
                 }
             } else {
                 JsonObject jsonobject = jsonelement.getAsJsonObject();
+
+                // Scissors start - Reject translatable components with more than 32 placeholders in them
+                if (calculatePlaceholderCount(jsonobject) > 32) {
+                    return new TextComponent("*** Component has too many placeholders ***").withStyle(ChatFormatting.RED);
+                }
+                // Scissors end
+
                 Object object;
 
                 if (jsonobject.has("text")) {