PaperMC/paper-server/patches/sources/net/minecraft/network/chat/ComponentSerialization.java.patch

--- a/net/minecraft/network/chat/ComponentSerialization.java
+++ b/net/minecraft/network/chat/ComponentSerialization.java
@@ -37,9 +37,31 @@
 
 public class ComponentSerialization {
     public static final Codec<Component> CODEC = Codec.recursive("Component", ComponentSerialization::createCodec);
-    public static final StreamCodec<RegistryFriendlyByteBuf, Component> STREAM_CODEC = ByteBufCodecs.fromCodecWithRegistries(CODEC);
+    public static final StreamCodec<RegistryFriendlyByteBuf, Component> STREAM_CODEC = createTranslationAware(() -> net.minecraft.nbt.NbtAccounter.create(net.minecraft.network.FriendlyByteBuf.DEFAULT_NBT_QUOTA)); // Paper - adventure
     public static final StreamCodec<RegistryFriendlyByteBuf, Optional<Component>> OPTIONAL_STREAM_CODEC = STREAM_CODEC.apply(ByteBufCodecs::optional);
-    public static final StreamCodec<RegistryFriendlyByteBuf, Component> TRUSTED_STREAM_CODEC = ByteBufCodecs.fromCodecWithRegistriesTrusted(CODEC);
+    // Paper start - adventure; use locale from bytebuf for translation
+    public static final ThreadLocal<Boolean> DONT_RENDER_TRANSLATABLES = ThreadLocal.withInitial(() -> false);
+    public static final StreamCodec<RegistryFriendlyByteBuf, Component> TRUSTED_STREAM_CODEC = createTranslationAware(net.minecraft.nbt.NbtAccounter::unlimitedHeap);
+    private static StreamCodec<RegistryFriendlyByteBuf, Component> createTranslationAware(final Supplier<net.minecraft.nbt.NbtAccounter> sizeTracker) {
+        return new StreamCodec<>() {
+            final StreamCodec<ByteBuf, net.minecraft.nbt.Tag> streamCodec = ByteBufCodecs.tagCodec(sizeTracker);
+            @Override
+            public Component decode(RegistryFriendlyByteBuf registryFriendlyByteBuf) {
+                net.minecraft.nbt.Tag tag = this.streamCodec.decode(registryFriendlyByteBuf);
+                RegistryOps<net.minecraft.nbt.Tag> registryOps = registryFriendlyByteBuf.registryAccess().createSerializationContext(net.minecraft.nbt.NbtOps.INSTANCE);
+                return CODEC.parse(registryOps, tag).getOrThrow(error -> new io.netty.handler.codec.DecoderException("Failed to decode: " + error + " " + tag));
+            }
+
+            @Override
+            public void encode(RegistryFriendlyByteBuf registryFriendlyByteBuf, Component object) {
+                RegistryOps<net.minecraft.nbt.Tag> registryOps = registryFriendlyByteBuf.registryAccess().createSerializationContext(net.minecraft.nbt.NbtOps.INSTANCE);
+                net.minecraft.nbt.Tag tag = (DONT_RENDER_TRANSLATABLES.get() ? CODEC : ComponentSerialization.localizedCodec(registryFriendlyByteBuf.adventure$locale))
+                    .encodeStart(registryOps, object).getOrThrow(error -> new io.netty.handler.codec.EncoderException("Failed to encode: " + error + " " + object));
+                this.streamCodec.encode(registryFriendlyByteBuf, tag);
+            }
+        };
+    }
+    // Paper end - adventure; use locale from bytebuf for translation
     public static final StreamCodec<RegistryFriendlyByteBuf, Optional<Component>> TRUSTED_OPTIONAL_STREAM_CODEC = TRUSTED_STREAM_CODEC.apply(
         ByteBufCodecs::optional
     );
@@ -100,7 +122,27 @@
         return ExtraCodecs.orCompressed(mapCodec3, mapCodec2);
     }
 
+    // Paper start - adventure; create separate codec for each locale
+    private static final java.util.Map<java.util.Locale, Codec<Component>> LOCALIZED_CODECS = new java.util.concurrent.ConcurrentHashMap<>();
+
+    public static Codec<Component> localizedCodec(final java.util.@org.checkerframework.checker.nullness.qual.Nullable Locale locale) {
+        if (locale == null) {
+            return CODEC;
+        }
+        return LOCALIZED_CODECS.computeIfAbsent(locale,
+            loc -> Codec.recursive("Component", selfCodec -> createCodec(selfCodec, loc)));
+    }
+
+
+    // Paper end - adventure; create separate codec for each locale
+
     private static Codec<Component> createCodec(Codec<Component> selfCodec) {
+        // Paper start - adventure; create separate codec for each locale
+        return createCodec(selfCodec, null);
+    }
+
+    private static Codec<Component> createCodec(Codec<Component> selfCodec, @javax.annotation.Nullable java.util.Locale locale) {
+        // Paper end - adventure; create separate codec for each locale
         ComponentContents.Type<?>[] types = new ComponentContents.Type[]{
             PlainTextContents.TYPE, TranslatableContents.TYPE, KeybindContents.TYPE, ScoreContents.TYPE, SelectorContents.TYPE, NbtContents.TYPE
         };
@@ -113,6 +155,34 @@
                     )
                     .apply(instance, MutableComponent::new)
         );
+        // Paper start - adventure; create separate codec for each locale
+        final Codec<Component> origCodec = codec;
+        codec = new Codec<>() {
+            @Override
+            public <T> DataResult<com.mojang.datafixers.util.Pair<Component, T>> decode(final DynamicOps<T> ops, final T input) {
+                return origCodec.decode(ops, input);
+            }
+
+            @Override
+            public <T> DataResult<T> encode(final Component input, final DynamicOps<T> ops, final T prefix) {
+                final net.kyori.adventure.text.Component adventureComponent;
+                if (input instanceof io.papermc.paper.adventure.AdventureComponent adv) {
+                    adventureComponent = adv.adventure$component();
+                } else if (locale != null && input.getContents() instanceof TranslatableContents && io.papermc.paper.adventure.PaperAdventure.hasAnyTranslations()) {
+                    adventureComponent = io.papermc.paper.adventure.PaperAdventure.asAdventure(input);
+                } else {
+                    return origCodec.encode(input, ops, prefix);
+                }
+                return io.papermc.paper.adventure.PaperAdventure.localizedCodec(locale)
+                    .encode(adventureComponent, ops, prefix);
+            }
+
+            @Override
+            public String toString() {
+                return origCodec.toString() + "[AdventureComponentAware]";
+            }
+        };
+        // Paper end - adventure; create separate codec for each locale
         return Codec.either(Codec.either(Codec.STRING, ExtraCodecs.nonEmptyList(selfCodec.listOf())), codec)
             .xmap(either -> either.map(either2 -> either2.map(Component::literal, ComponentSerialization::createFromList), text -> (Component)text), text -> {
                 String string = text.tryCollapseToString();