mobai null resolution

src/engine/objects/Building.java

@@ -395,8 +395,10 @@ public class Building extends AbstractWorldObject {
                 //friendly building has been attacked, add attacker to city outlaw list
                 if (!playerCity.cityOutlaws.contains(attacker.getObjectUUID()) && attacker.getObjectType().equals(GameObjectType.PlayerCharacter))
                     playerCity.cityOutlaws.add(attacker.getObjectUUID());
+                //only city guards respond; siege engines and pets in the zone are left alone
+
                 for (Mob guard : playerCity.getParent().zoneMobSet)
-                    if (guard.combatTarget == null)
+                    if (guard.isPlayerGuard() && guard.combatTarget == null)
                         guard.setCombatTarget(attacker);
             }
         }