added error messaging for vehicle-decon Actor, should something go wrong with the unregistering process

pslogin/src/main/scala/WorldSessionActor.scala

@@ -1692,6 +1692,13 @@ class WorldSessionActor extends Actor with MDCContextAware {
     )
   }
 
+  /**
+    * Construct tasking that adds a completed and registered vehicle into the scene.
+    * Use this function to renew the globally unique identifiers on a vehicle that has already been added to the scene once.
+    * @param vehicle the `Vehicle` object
+    * @see `RegisterNewVehicle`
+    * @return a `TaskResolver.GiveTask` message
+    */
   def RegisterVehicle(vehicle : Vehicle) : TaskResolver.GiveTask = {
     TaskResolver.GiveTask(
       new Task() {
@@ -1716,6 +1723,16 @@ class WorldSessionActor extends Actor with MDCContextAware {
     )
   }
 
+  /**
+    * Construct tasking that adds a completed and registered vehicle into the scene.
+    * The major difference between `RegisterVehicle` and `RegisterNewVehicle` is the assumption that this vehicle lacks an internal `Actor`.
+    * Before being finished, that vehicle is supplied an `Actor` such that it may function properly.
+    * This function wraps around `RegisterVehicle` and is used in case, prior to this event,
+    * the vehicle is being brought into existence from scratch and was never a member of any `Zone`.
+    * @param obj the `Vehicle` object
+    * @see `RegisterVehicle`
+    * @return a `TaskResolver.GiveTask` message
+    */
   def RegisterNewVehicle(obj : Vehicle) : TaskResolver.GiveTask = {
     TaskResolver.GiveTask(
       new Task() {
@@ -1936,10 +1953,23 @@ object WorldSessionActor {
     def isCancelled() : Boolean = true
   }
 
+  /**
+    * Calculate the actual distance between two points.
+    * @param pos1 the first point
+    * @param pos2 the second point
+    * @return the distance
+    */
   def Distance(pos1 : Vector3, pos2 : Vector3) : Float = {
     math.sqrt(DistanceSquared(pos1, pos2)).toFloat
   }
 
+  /**
+    * Calculate the squared distance between two points.
+    * Though some time is saved care must be taken that any comparative distance is also squared.
+    * @param pos1 the first point
+    * @param pos2 the second point
+    * @return the distance
+    */
   def DistanceSquared(pos1 : Vector3, pos2 : Vector3) : Float = {
     val dx : Float = pos1.x - pos2.x
     val dy : Float = pos1.y - pos2.y

pslogin/src/main/scala/services/vehicle/support/DeconstructionActor.scala

@@ -3,7 +3,7 @@ package services.vehicle.support
 
 import akka.actor.{Actor, ActorRef, Cancellable}
 import net.psforever.objects.Vehicle
-import net.psforever.objects.guid.GUIDTask
+import net.psforever.objects.guid.TaskResolver
 import net.psforever.objects.vehicles.Seat
 import net.psforever.objects.zones.Zone
 import net.psforever.packet.game.PlanetSideGUID
@@ -79,7 +79,7 @@ class DeconstructionActor extends Actor {
         entry.zone.Transport ! Zone.DespawnVehicle(vehicle)
         context.parent ! DeconstructionActor.DeleteVehicle(vehicle.GUID, zone.Id) //call up to the main event system
         context.parent ! VehicleServiceMessage.RevokeActorControl(vehicle) //call up to a sibling manager
-        taskResolver ! GUIDTask.UnregisterVehicle(vehicle)(zone.GUID)
+        taskResolver ! DeconstructionTask(vehicle, zone)
       })
 
       if(vehiclesRemain.nonEmpty) {
@@ -88,9 +88,39 @@ class DeconstructionActor extends Actor {
         scrappingProcess = context.system.scheduler.scheduleOnce(short_timeout, self, DeconstructionActor.TryDeleteVehicle())
       }
 
+    case DeconstructionActor.FailureToDeleteVehicle(localVehicle, localZone, ex) =>
+      org.log4s.getLogger.error(s"vehicle deconstruction: $localVehicle failed to be properly cleaned up from zone $localZone - $ex")
+
     case _ => ;
   }
 
+  /**
+    * Construct a middleman `Task` intended to return error messages to the `DeconstructionActor`.
+    * @param vehicle the `Vehicle` object
+    * @param zone the `Zone` in which the vehicle resides
+    * @return a `TaskResolver.GiveTask` message
+    */
+  def DeconstructionTask(vehicle : Vehicle, zone : Zone) : TaskResolver.GiveTask = {
+    import net.psforever.objects.guid.{GUIDTask, Task}
+    TaskResolver.GiveTask (
+      new Task() {
+        private val localVehicle = vehicle
+        private val localZone = zone
+        private val localAnnounce = self
+
+        override def isComplete : Task.Resolution.Value = Task.Resolution.Success
+
+        def Execute(resolver : ActorRef) : Unit = {
+          resolver ! scala.util.Success(this)
+        }
+
+        override def onFailure(ex : Throwable): Unit = {
+          localAnnounce ! DeconstructionActor.FailureToDeleteVehicle(localVehicle, localZone, ex)
+        }
+      }, List(GUIDTask.UnregisterVehicle(vehicle)(zone.GUID))
+    )
+  }
+
   /**
     * Iterate over entries in a `List` until an entry that does not exceed the time limit is discovered.
     * Separate the original `List` into two:
@@ -168,6 +198,14 @@ object DeconstructionActor {
     */
   private final case class TryDeleteVehicle()
 
+  /**
+    * Error-passing message carrying information out of the final deconstruction GUID unregistering task.
+    * @param vehicle the `Vehicle` object
+    * @param zone the `Zone` in which the vehicle may or may not reside
+    * @param ex information regarding what happened
+    */
+  private final case class FailureToDeleteVehicle(vehicle : Vehicle, zone : Zone, ex : Throwable)
+
   /**
     * Entry of vehicle information.
     * The `zone` is maintained separately as a necessity, required to complete the deletion of the vehicle