Filter invalid remove teams packets in 1.20.3->1.20.5 (#4643)

Closes https://github.com/ViaVersion/ViaVersion/issues/4564

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/Protocol1_20_3To1_20_5.java

@@ -52,6 +52,7 @@ import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.rewriter.EntityPacket
 import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.rewriter.ParticleRewriter1_20_5;
 import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.storage.AcknowledgedMessagesStorage;
 import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.storage.ArmorTrimStorage;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.storage.ScoreboardTeamStorage;
 import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.storage.TagKeys;
 import com.viaversion.viaversion.protocols.v1_20to1_20_2.packet.ServerboundConfigurationPackets1_20_2;
 import com.viaversion.viaversion.rewriter.SoundRewriter;
@@ -60,6 +61,7 @@ import com.viaversion.viaversion.rewriter.TagRewriter;
 import com.viaversion.viaversion.rewriter.text.JsonNBTComponentRewriter;
 import com.viaversion.viaversion.util.ProtocolLogger;
 import java.util.BitSet;
+import java.util.Objects;
 import java.util.UUID;
 
 import static com.viaversion.viaversion.util.ProtocolUtil.packetTypeMap;
@@ -222,6 +224,51 @@ public final class Protocol1_20_3To1_20_5 extends AbstractProtocol<ClientboundPa
             wrapper.write(Types.BOOLEAN, strictErrorHandling);
         });
 
+        registerClientbound(ClientboundPackets1_20_3.SET_PLAYER_TEAM, wrapper -> {
+            final String teamName = wrapper.passthrough(Types.STRING);
+            final byte action = wrapper.passthrough(Types.BYTE);
+            if (action == 2) {
+                return;
+            }
+
+            final ScoreboardTeamStorage storage = wrapper.user().get(ScoreboardTeamStorage.class);
+            if (action == 1) {
+                storage.removeTeam(teamName);
+                return;
+            } else if (action == 0) {
+                storage.createTeam(teamName);
+                wrapper.passthrough(Types.TAG); // Display name
+                wrapper.passthrough(Types.BYTE); // Flags
+                wrapper.passthrough(Types.STRING); // Name Tag Visibility
+                wrapper.passthrough(Types.STRING); // Collision rule
+                wrapper.passthrough(Types.VAR_INT); // Color
+                wrapper.passthrough(Types.TAG); // Prefix
+                wrapper.passthrough(Types.TAG); // Suffix
+
+                final String[] players = wrapper.passthrough(Types.STRING_ARRAY);
+                storage.addPlayerToTeam(teamName, players);
+                return;
+            }
+
+            final String[] players = wrapper.passthrough(Types.STRING_ARRAY);
+            if (action == 3) {
+                storage.addPlayerToTeam(teamName, players);
+            } else if (action != 4) {
+                return;
+            }
+
+            // Drop invalid remove packets to not break when plugins do that, since strict error handling is enforced in newer protocols.
+            for (final String player : players) {
+                final String team = storage.getPlayerTeam(player);
+                if (!Objects.equals(team, teamName)) {
+                    wrapper.cancel();
+                    return;
+                }
+
+                storage.removeFromTeam(teamName, player);
+            }
+        });
+
         cancelServerbound(State.LOGIN, ServerboundLoginPackets.COOKIE_RESPONSE.getId());
         cancelServerbound(ServerboundConfigurationPackets1_20_5.COOKIE_RESPONSE);
         cancelServerbound(ServerboundConfigurationPackets1_20_5.SELECT_KNOWN_PACKS);
@@ -300,6 +347,7 @@ public final class Protocol1_20_3To1_20_5 extends AbstractProtocol<ClientboundPa
         addEntityTracker(connection, new EntityTrackerBase(connection, EntityTypes1_20_5.PLAYER));
         connection.put(new AcknowledgedMessagesStorage());
         connection.put(new ArmorTrimStorage());
+        connection.put(new ScoreboardTeamStorage());
     }
 
     @Override

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/EntityPacketRewriter1_20_5.java

@@ -48,6 +48,7 @@ import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ClientboundCon
 import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ClientboundPackets1_20_5;
 import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.storage.AcknowledgedMessagesStorage;
 import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.storage.ArmorTrimStorage;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.storage.ScoreboardTeamStorage;
 import com.viaversion.viaversion.rewriter.EntityRewriter;
 import com.viaversion.viaversion.util.Key;
 import com.viaversion.viaversion.util.KeyMappings;
@@ -297,6 +298,8 @@ public final class EntityPacketRewriter1_20_5 extends EntityRewriter<Clientbound
 
             final byte gamemode = wrapper.passthrough(Types.BYTE);
             sendRangeAttributes(wrapper.user(), gamemode == GameMode.CREATIVE.id());
+
+            wrapper.user().put(new ScoreboardTeamStorage());
         });
 
         protocol.registerClientbound(ClientboundPackets1_20_3.UPDATE_MOB_EFFECT, wrapper -> {

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/storage/ScoreboardTeamStorage.java

@@ -0,0 +1,64 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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.v1_20_3to1_20_5.storage;
+
+import com.viaversion.viaversion.api.connection.StorableObject;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+public final class ScoreboardTeamStorage implements StorableObject {
+
+    private final Map<String, Set<String>> teams = new HashMap<>();
+
+    public void createTeam(final String name) {
+        if (this.teams.containsKey(name)) {
+            return;
+        }
+
+        this.teams.put(name, new HashSet<>());
+    }
+
+    public void removeTeam(final String name) {
+        this.teams.remove(name);
+    }
+
+    public void addPlayerToTeam(final String team, final String[] player) {
+        final Set<String> players = this.teams.computeIfAbsent(team, k -> new HashSet<>());
+        Collections.addAll(players, player);
+    }
+
+    public void removeFromTeam(final String team, final String player) {
+        final Set<String> players = this.teams.get(team);
+        if (players != null) {
+            players.remove(player);
+        }
+    }
+
+    public String getPlayerTeam(final String player) {
+        for (final Map.Entry<String, Set<String>> entry : this.teams.entrySet()) {
+            if (entry.getValue().contains(player)) {
+                return entry.getKey();
+            }
+        }
+        return null;
+    }
+
+}