Many various fixes

core/src/io/anuke/mindustry/entities/traits/SpawnerTrait.java

@@ -1,7 +1,7 @@
 package io.anuke.mindustry.entities.traits;
 
 import io.anuke.arc.math.geom.Position;
-import io.anuke.mindustry.entities.type.Player;
+import io.anuke.mindustry.entities.type.*;
 import io.anuke.mindustry.world.Tile;
 
 public interface SpawnerTrait extends TargetTrait, Position{
@@ -9,6 +9,8 @@ public interface SpawnerTrait extends TargetTrait, Position{
 
     void updateSpawning(Player unit);
 
+    boolean hasUnit(Unit unit);
+
     @Override
     default boolean isValid(){
         return getTile().entity instanceof SpawnerTrait;

core/src/io/anuke/mindustry/entities/type/Player.java

@@ -919,7 +919,7 @@ public class Player extends Unit implements BuilderMinerTrait, ShooterTrait{
         buffer.writeInt(Color.rgba8888(color));
         buffer.writeByte(mech.id);
         buffer.writeInt(mining == null ? noSpawner : mining.pos());
-        buffer.writeInt(spawner == null ? noSpawner : spawner.getTile().pos());
+        buffer.writeInt(spawner == null || !spawner.hasUnit(this) ? noSpawner : spawner.getTile().pos());
         buffer.writeShort((short)(baseRotation * 2));
 
         writeBuilding(buffer);