Configuration API (#12301)

This implements a solution that preemptively exits the tick loop if we have already marked the connection as disconnecting. This avoids changing the result of Connection#isConnected in order to avoid other possibly unintentional changes. Fundamentally it should be investigated if closing the connection async is really still needed.

This also additionally removes the login disconnecting logic for server stopping, as this was also a possible issue in the config stage but also shouldn't be an issue as connections are closed on server stop very early.

Additionally, do not check for isConnecting() on VERIFYING, as that seemed to be an old diff originally trying to resolve this code, however isConnected is not updated at this point so it pretty much was useless.

paper-server/patches/sources/net/minecraft/network/Connection.java.patch

@@ -29,7 +29,7 @@
      @Nullable
      private volatile PacketListener disconnectListener;
      @Nullable
-@@ -106,6 +_,40 @@
+@@ -106,6 +_,41 @@
      private volatile DisconnectionDetails delayedDisconnect;
      @Nullable
      BandwidthDebugMonitor bandwidthDebugMonitor;
@@ -44,8 +44,7 @@
 +        if (this.packetListener instanceof net.minecraft.server.network.ServerGamePacketListenerImpl impl) {
 +            return impl.player;
 +        } else if (this.packetListener instanceof net.minecraft.server.network.ServerCommonPacketListenerImpl impl) {
-+            org.bukkit.craftbukkit.entity.CraftPlayer player = impl.getCraftPlayer();
-+            return player == null ? null : player.getHandle();
++            return null;
 +        }
 +        return null;
 +    }
@@ -67,6 +66,8 @@
 +    }
 +    // Paper end - packet limiter
 +    @Nullable public SocketAddress haProxyAddress; // Paper - Add API to get player's proxy address
++    public @Nullable java.util.Optional<net.minecraft.network.chat.Component> legacySavedLoginEventResultOverride; // Paper - playerloginevent
++    public @Nullable net.minecraft.server.level.ServerPlayer savedPlayerForLoginEventLegacy; // Paper - playerloginevent
  
      public Connection(PacketFlow receiving) {
          this.receiving = receiving;