Fix potential issues with the Minecraft FakePlayer lingering around after world unloads.

src/main/java/net/minecraftforge/common/util/FakePlayer.java

@@ -19,6 +19,8 @@
 
 package net.minecraftforge.common.util;
 
+import javax.annotation.Nullable;
+
 import com.mojang.authlib.GameProfile;
 
 import net.minecraft.entity.Entity;
@@ -26,6 +28,7 @@ import net.minecraftforge.fml.common.FMLCommonHandler;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.entity.player.EntityPlayerMP;
 import net.minecraft.network.play.client.CPacketClientSettings;
+import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.management.PlayerInteractionManager;
 import net.minecraft.stats.StatBase;
 import net.minecraft.util.DamageSource;
@@ -54,4 +57,5 @@ public class FakePlayer extends EntityPlayerMP
     @Override public void onUpdate(){ return; }
     @Override public Entity changeDimension(int dim, ITeleporter teleporter){ return this; }
     @Override public void handleClientSettings(CPacketClientSettings pkt){ return; }
+    @Override @Nullable public MinecraftServer getServer() { return FMLCommonHandler.instance().getMinecraftServerInstance(); }
 }

src/main/java/net/minecraftforge/common/util/FakePlayerFactory.java

@@ -68,5 +68,13 @@ public class FakePlayerFactory
     public static void unloadWorld(WorldServer world)
     {
         fakePlayers.entrySet().removeIf(entry -> entry.getValue().world == world);
+        if (MINECRAFT_PLAYER != null && MINECRAFT_PLAYER.get() != null && MINECRAFT_PLAYER.get().world == world) // This shouldn't be strictly necessary, but lets be aggressive.
+        {
+            FakePlayer mc = MINECRAFT_PLAYER.get();
+            if (mc != null && mc.world == world)
+            {
+                MINECRAFT_PLAYER = null;
+            }
+        }
     }
 }