Send last tags when re-entering config phase

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_20_2to1_20/Protocol1_20_2To1_20.java

@@ -48,10 +48,10 @@ import com.viaversion.viaversion.protocols.protocol1_20_2to1_20.rewriter.EntityP
 import com.viaversion.viaversion.protocols.protocol1_20_2to1_20.storage.ConfigurationState;
 import com.viaversion.viaversion.protocols.protocol1_20_2to1_20.storage.ConfigurationState.BridgePhase;
 import com.viaversion.viaversion.protocols.protocol1_20_2to1_20.storage.LastResourcePack;
+import com.viaversion.viaversion.protocols.protocol1_20_2to1_20.storage.LastTags;
 import com.viaversion.viaversion.rewriter.SoundRewriter;
-import org.checkerframework.checker.nullness.qual.Nullable;
-
 import java.util.UUID;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 public final class Protocol1_20_2To1_20 extends AbstractProtocol<ClientboundPackets1_19_4, ClientboundPackets1_20_2, ServerboundPackets1_19_4, ServerboundPackets1_20_2> {
 
@@ -95,6 +95,10 @@ public final class Protocol1_20_2To1_20 extends AbstractProtocol<ClientboundPack
             wrapper.user().put(new LastResourcePack(url, hash, required, prompt));
         });
 
+        registerClientbound(ClientboundPackets1_19_4.TAGS, wrapper -> wrapper.user().put(new LastTags(wrapper)));
+        registerClientbound(State.CONFIGURATION, ClientboundConfigurationPackets1_20_2.UPDATE_TAGS.getId(), ClientboundConfigurationPackets1_20_2.UPDATE_TAGS.getId(),
+                wrapper -> wrapper.user().put(new LastTags(wrapper)));
+
         registerClientbound(ClientboundPackets1_19_4.DISPLAY_SCOREBOARD, wrapper -> {
             final byte slot = wrapper.read(Type.BYTE);
             wrapper.write(Type.VAR_INT, (int) slot);
@@ -220,7 +224,13 @@ public final class Protocol1_20_2To1_20 extends AbstractProtocol<ClientboundPack
             return;
         }
 
+        final int unmappedId = packetWrapper.getId();
         if (phase == BridgePhase.PROFILE_SENT || phase == BridgePhase.REENTERING_CONFIGURATION) {
+            if (unmappedId == ClientboundPackets1_19_4.TAGS.getId()) {
+                // Don't re-send old tags during config phase
+                packetWrapper.user().remove(LastTags.class);
+            }
+
             // Queue packets sent by the server while we wait for the client to transition to the configuration state
             configurationBridge.addPacketToQueue(packetWrapper, true);
             throw CancelException.generate();
@@ -228,7 +238,6 @@ public final class Protocol1_20_2To1_20 extends AbstractProtocol<ClientboundPack
 
         if (packetWrapper.getPacketType() == null || packetWrapper.getPacketType().state() != State.CONFIGURATION) {
             // Map some of them to their configuration state counterparts, but make sure to let join game through
-            final int unmappedId = packetWrapper.getId();
             if (unmappedId == ClientboundPackets1_19_4.JOIN_GAME.getId()) {
                 super.transform(direction, State.PLAY, packetWrapper);
                 return;
@@ -287,6 +296,12 @@ public final class Protocol1_20_2To1_20 extends AbstractProtocol<ClientboundPack
         enableFeaturesPacket.write(Type.STRING, "minecraft:vanilla");
         enableFeaturesPacket.send(Protocol1_20_2To1_20.class);
 
+        final LastTags lastTags = connection.get(LastTags.class);
+        if (lastTags != null) {
+            // The server might still follow up with a tags packet, but we wouldn't know
+            lastTags.sendLastTags(connection);
+        }
+
         if (lastResourcePack != null) {
             // The client for some reason drops the resource pack when reentering the configuration state
             final PacketWrapper resourcePackPacket = PacketWrapper.create(ClientboundConfigurationPackets1_20_2.RESOURCE_PACK, connection);

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_20_2to1_20/storage/LastResourcePack.java

@@ -50,4 +50,9 @@ public final class LastResourcePack implements StorableObject {
     public @Nullable JsonElement prompt() {
         return prompt;
     }
+
+    @Override
+    public boolean clearOnServerSwitch() {
+        return false;
+    }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_20_2to1_20/storage/LastTags.java

@@ -0,0 +1,87 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2023 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.protocols.protocol1_20_2to1_20.storage;
+
+import com.viaversion.viaversion.api.connection.StorableObject;
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.protocols.protocol1_20_2to1_20.Protocol1_20_2To1_20;
+import com.viaversion.viaversion.protocols.protocol1_20_2to1_20.packet.ClientboundConfigurationPackets1_20_2;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+public class LastTags implements StorableObject {
+
+    private final List<RegistryTags> registryTags = new ArrayList<>();
+
+    public LastTags(final PacketWrapper wrapper) throws Exception {
+        final int length = wrapper.passthrough(Type.VAR_INT);
+        for (int i = 0; i < length; i++) {
+            final List<Tag> tags = new ArrayList<>();
+            final String registryKey = wrapper.passthrough(Type.STRING);
+            final int tagsSize = wrapper.passthrough(Type.VAR_INT);
+            for (int j = 0; j < tagsSize; j++) {
+                final String key = wrapper.passthrough(Type.STRING);
+                final int[] ids = wrapper.passthrough(Type.VAR_INT_ARRAY_PRIMITIVE);
+                tags.add(new Tag(key, ids));
+            }
+
+            this.registryTags.add(new RegistryTags(registryKey, tags));
+        }
+    }
+
+    public void sendLastTags(final UserConnection connection) throws Exception {
+        if (registryTags.isEmpty()) {
+            return;
+        }
+
+        final PacketWrapper packet = PacketWrapper.create(ClientboundConfigurationPackets1_20_2.UPDATE_TAGS, connection);
+        packet.write(Type.VAR_INT, registryTags.size());
+        for (final RegistryTags registryTag : registryTags) {
+            packet.write(Type.STRING, registryTag.registryKey);
+            packet.write(Type.VAR_INT, registryTag.tags.size());
+            for (final Tag tag : registryTag.tags) {
+                packet.write(Type.STRING, tag.key);
+                packet.write(Type.VAR_INT_ARRAY_PRIMITIVE, Arrays.copyOf(tag.ids, tag.ids.length));
+            }
+        }
+        packet.send(Protocol1_20_2To1_20.class);
+    }
+
+    private static final class RegistryTags {
+        private final String registryKey;
+        private final List<Tag> tags;
+
+        private RegistryTags(final String registryKey, final List<Tag> tags) {
+            this.registryKey = registryKey;
+            this.tags = tags;
+        }
+    }
+
+    private static final class Tag {
+        private final String key;
+        private final int[] ids;
+
+        private Tag(final String key, final int[] ids) {
+            this.key = key;
+            this.ids = ids;
+        }
+    }
+}