(vanilla fix) resolve NPE in NetHandlerPlayClient#handleSpawnPlayer

src/main/java/net/silentclient/client/mixin/mixins/NetHandlerPlayClientMixin.java

@@ -4,7 +4,9 @@ import net.minecraft.client.entity.EntityPlayerSP;
 import net.minecraft.client.gui.GuiScreen;
 import net.minecraft.client.multiplayer.WorldClient;
 import net.minecraft.client.network.NetHandlerPlayClient;
+import net.minecraft.client.network.NetworkPlayerInfo;
 import net.minecraft.network.play.server.S01PacketJoinGame;
+import net.minecraft.network.play.server.S0CPacketSpawnPlayer;
 import net.minecraft.network.play.server.S19PacketEntityStatus;
 import net.minecraft.network.play.server.S48PacketResourcePackSend;
 import net.minecraft.util.IChatComponent;
@@ -16,9 +18,28 @@ import org.spongepowered.asm.mixin.Shadow;
 import org.spongepowered.asm.mixin.injection.*;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 
+import java.util.UUID;
+
 @Mixin(NetHandlerPlayClient.class)
-public class NetHandlerPlayClientMixin {
+public abstract class NetHandlerPlayClientMixin {
     @Shadow private WorldClient clientWorldController;
+    @Shadow
+    public abstract NetworkPlayerInfo getPlayerInfo(UUID p_175102_1_);
+
+    @Inject(
+            method = "handleSpawnPlayer",
+            cancellable = true,
+            at =
+            @At(
+                    value = "INVOKE",
+                    target = "Lnet/minecraft/network/PacketThreadUtil;checkThreadAndEnqueue(Lnet/minecraft/network/Packet;Lnet/minecraft/network/INetHandler;Lnet/minecraft/util/IThreadListener;)V",
+                    shift = At.Shift.AFTER
+            ))
+    private void patcher$fixHandleSpawnPlayerNPE(S0CPacketSpawnPlayer packetIn, CallbackInfo ci) {
+        if (this.getPlayerInfo(packetIn.getPlayer()) == null) {
+            ci.cancel();
+        }
+    }
 
     @Inject(method = "handleEntityStatus", at = @At("RETURN"))
     public void callEntityDamageEvent(S19PacketEntityStatus packetIn, CallbackInfo ci) {