fix(login): PacketEvents User channel for deferred LOGIN_START

CHANGELOG.md

@@ -1,3 +1,10 @@
+## 1.0.7 — Deferred Pre-login Channel Fix
+
+- Fix deferred inbound `LOGIN.CLIENT.LOGIN_START` failure when ProtocolLib2PacketEvents had a generated `TemporaryPlayer` instead of a Bukkit `CraftPlayer`: use the already associated PacketEvents pre-login `User` and its live Netty Channel for silent transport instead of `PlayerManager.receivePacketSilently(Player, ...)`.
+- Also route pre-login clientbound packets through the same User to avoid the analogous invalid CraftPlayer cast.
+- Reject missing temporary User/channel rather than bypassing login authentication or swallowing the packet; ordinary CraftPlayer packet transport is unchanged.
+- Add focused offline transport-selection regression tests; Maven test suite passes.
+
 # Changelog
 
 All notable changes to ProtocolLib2PacketEvents (P2P) are documented here.

pom.xml

@@ -5,7 +5,7 @@
 
     <groupId>com.comphenix.protocol</groupId>
     <artifactId>ProtocolLib2PacketEvents</artifactId>
-    <version>1.0.6</version>
+    <version>1.0.7</version>
     <packaging>jar</packaging>
 
     <name>ProtocolLib2PacketEvents</name>

src/main/java/com/comphenix/protocol/internal/PacketEventsBackend.java

@@ -2,6 +2,9 @@
 
 import com.comphenix.protocol.events.PacketContainer;
 import com.github.retrooper.packetevents.PacketEvents;
+import com.github.retrooper.packetevents.protocol.player.User;
+import com.comphenix.protocol.injector.temporary.TemporaryPlayer;
+import com.comphenix.protocol.injector.temporary.TemporaryPlayerAdapter;
 import org.bukkit.entity.Player;
 
 /** PacketEvents transport for structured packets. */
@@ -18,6 +21,15 @@ private static void requireStructured(PacketContainer packet, String action) {
     public void send(Player player, PacketContainer packet, boolean filters) {
         requireStructured(packet, "send");
         Object wrapper = packet.getPacketWrapper();
+        User preLogin = temporaryTransport(player);
+        if (preLogin != null) {
+            if (wrapper != null) {
+                if (filters) preLogin.sendPacket(packet.getPacketWrapper());
+                else preLogin.sendPacketSilently(packet.getPacketWrapper());
+            } else if (filters) preLogin.sendPacket(packet.getHandle());
+            else preLogin.sendPacketSilently(packet.getHandle());
+            return;
+        }
         if (wrapper != null) {
             if (filters) PacketEvents.getAPI().getPlayerManager().sendPacket(player, packet.getPacketWrapper());
             else PacketEvents.getAPI().getPlayerManager().sendPacketSilently(player, packet.getPacketWrapper());
@@ -28,10 +40,37 @@ public void send(Player player, PacketContainer packet, boolean filters) {
         }
     }
 
+    /**
+     * A LOGIN/CONFIGURATION packet may have a ProtocolLib temporary player,
+     * not a Bukkit CraftPlayer. The PacketEvents PlayerManager casts its input
+     * to CraftPlayer; for temporary players the underlying pre-login User owns
+     * the real channel and must be used for transport.
+     *
+     * Fail loudly if its channel is missing, instead of silently discarding a
+     * credential-bearing LOGIN_START or bypassing authentication listeners.
+     */
+    static User temporaryTransport(Player player) {
+        if (!(player instanceof TemporaryPlayer)) return null;
+        User user = TemporaryPlayerAdapter.getUser(player);
+        if (user == null || user.getChannel() == null) {
+            throw new IllegalStateException("Temporary ProtocolLib player has no PacketEvents login channel");
+        }
+        return user;
+    }
+
     @Override
     public void receive(Player player, PacketContainer packet, boolean filters) {
         requireStructured(packet, "receive");
         Object wrapper = packet.getPacketWrapper();
+        User preLogin = temporaryTransport(player);
+        if (preLogin != null) {
+            if (wrapper != null) {
+                if (filters) preLogin.receivePacket(packet.getPacketWrapper());
+                else preLogin.receivePacketSilently(packet.getPacketWrapper());
+            } else if (filters) preLogin.receivePacket(packet.getHandle());
+            else preLogin.receivePacketSilently(packet.getHandle());
+            return;
+        }
         if (wrapper != null) {
             if (filters) PacketEvents.getAPI().getPlayerManager().receivePacket(player, packet.getPacketWrapper());
             else PacketEvents.getAPI().getPlayerManager().receivePacketSilently(player, packet.getPacketWrapper());

src/main/resources/plugin.yml

@@ -6,11 +6,11 @@ main: com.comphenix.protocol.ProtocolLib
 # Bukkit.getPluginManager().getPlugin("ProtocolLib") - which resolves to this plugin
 # through `provides` below - and refuse to enable any ProtocolLib older than v5.0.0,
 # because ProtocolLib 4.x is genuinely incompatible with PacketEvents 2.x. P2P's real
-# release version (1.0.6) is carried by the jar name and the GitHub releases.
+# release version (1.0.7) is carried by the jar name and the GitHub releases.
 version: 5.4.0
 author: CyoriaSMP Team
 description: A drop-in ProtocolLib compatibility layer powered by PacketEvents.
-p2p-version: 1.0.6
+p2p-version: 1.0.7
 protocol-lib-api-version: 5.4.0
 depend: [packetevents]
 provides: [ProtocolLib]

src/test/java/com/comphenix/protocol/internal/PacketEventsBackendTemporaryUserTest.java

@@ -0,0 +1,32 @@
+package com.comphenix.protocol.internal;
+
+import com.comphenix.protocol.injector.temporary.TemporaryPlayerFactory;
+import org.bukkit.entity.Player;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class PacketEventsBackendTemporaryUserTest {
+    @Test
+    void fullyJoinedPlayerDoesNotUsePreLoginTransport() {
+        // The early guard is null-safe and the real-player path is untouched.
+        assertNull(PacketEventsBackend.temporaryTransport(null));
+    }
+
+    @Test
+    void anonymousTemporaryPlayerWithoutUserFailsClosed() {
+        Player facade = TemporaryPlayerFactory.createTemporaryPlayer();
+        IllegalStateException error = assertThrows(IllegalStateException.class,
+                () -> PacketEventsBackend.temporaryTransport(facade));
+        assertTrue(error.getMessage().contains("no PacketEvents login channel"));
+    }
+
+    @Test
+    void temporaryTransportRejectsUnmappedFacadeWithoutTryingCraftPlayerCast() {
+        // This regression guard tests the pre-login failure mode without a
+        // running PacketEvents API (which User's constructor requires).
+        Player facade = TemporaryPlayerFactory.createTemporaryPlayer();
+        assertThrows(IllegalStateException.class,
+                () -> PacketEventsBackend.temporaryTransport(facade));
+    }
+}