continue;	// the destination vehicle is already full

			units_moved = min(source->cargo_count, dest->cargo_cap - dest->cargo_count);

			source->cargo_count -= units_moved;

			dest->cargo_count   += units_moved;

			dest->cargo_source   = source->cargo_source;

			// copy the age of the cargo

			dest->cargo_days   = source->cargo_days;

			dest->day_counter  = source->day_counter;

			dest->tick_counter = source->tick_counter;

		} while (source->cargo_count > 0 && (dest = dest->next) != NULL);

		dest = v;

	} while ((source = source->next) != NULL);

}

/* Replaces a vehicle (used to be called autorenew)

 * This function is only called from MaybeReplaceVehicle()

 * Must be called with _current_player set to the owner of the vehicle

 * @param w Vehicle to replace

 * @param flags is the flags to use when calling DoCommand(). Mainly DC_EXEC counts

 * @return value is cost of the replacement or CMD_ERROR

 */

static int32 ReplaceVehicle(Vehicle **w, byte flags)

{

	int32 cost;

	Vehicle *old_v = *w;

	const Player *p = GetPlayer(old_v->owner);

	EngineID new_engine_type;

	const UnitID cached_unitnumber = old_v->unitnumber;

	bool new_front = false;

	Vehicle *new_v = NULL;

	char vehicle_name[32];

	new_engine_type = EngineReplacementForPlayer(p, old_v->engine_type);

	if (new_engine_type == INVALID_ENGINE) new_engine_type = old_v->engine_type;

	cost = DoCommand(old_v->x_pos, old_v->y_pos, new_engine_type, 1, flags, CMD_BUILD_VEH(old_v->type));

	if (CmdFailed(cost)) return cost;

	if (flags & DC_EXEC) {

		new_v = GetVehicle(_new_vehicle_id);

		*w = new_v;	//we changed the vehicle, so MaybeReplaceVehicle needs to work on the new one. Now we tell it what the new one is

		/* refit if needed */

		if (new_v->type != VEH_Road) { // road vehicles can't be refitted

			if (old_v->cargo_type != new_v->cargo_type && old_v->cargo_cap != 0 && new_v->cargo_cap != 0) {// some train engines do not have cargo capacity

			}

		}

		if (old_v->type == VEH_Train && !IsFrontEngine(old_v)) {

			/* this is a railcar. We need to move the car into the train

			 * We add the new engine after the old one instead of replacing it. It will give the same result anyway when we

			 * sell the old engine in a moment

			 */

			DoCommand(0, 0, (GetPrevVehicleInChain(old_v)->index << 16) | new_v->index, 1, DC_EXEC, CMD_MOVE_RAIL_VEHICLE);

			/* Now we move the old one out of the train */

			DoCommand(0, 0, (INVALID_VEHICLE << 16) | old_v->index, 0, DC_EXEC, CMD_MOVE_RAIL_VEHICLE);

		} else {

			// copy/clone the orders

			DoCommand(0, 0, (old_v->index << 16) | new_v->index, IsOrderListShared(old_v) ? CO_SHARE : CO_COPY, DC_EXEC, CMD_CLONE_ORDER);

			new_v->cur_order_index = old_v->cur_order_index;

			ChangeVehicleViewWindow(old_v, new_v);

			new_v->profit_this_year = old_v->profit_this_year;

			new_v->profit_last_year = old_v->profit_last_year;

			new_front = true;

			new_v->current_order = old_v->current_order;

			if (old_v->type == VEH_Train && GetNextVehicle(old_v) != NULL){

				Vehicle *temp_v = GetNextVehicle(old_v);

				// move the entire train to the new engine, excluding the old engine

				if (IsMultiheaded(old_v) && temp_v == old_v->u.rail.other_multiheaded_part) {

					// we got front and rear of a multiheaded engine right after each other. We should work with the next in line instead

					temp_v = GetNextVehicle(temp_v);

				}

				if (temp_v != NULL) {

					DoCommand(0, 0, (new_v->index << 16) | temp_v->index, 1, DC_EXEC, CMD_MOVE_RAIL_VEHICLE);

				}

			}

		}

		/* We are done setting up the new vehicle. Now we move the cargo from the old one to the new one */

		MoveVehicleCargo(new_v->type == VEH_Train ? GetFirstVehicleInChain(new_v) : new_v, old_v);

		// Get the name of the old vehicle if it has a custom name.

		if ((old_v->string_id & 0xF800) != 0x7800) {

			vehicle_name[0] = '\0';

		} else {

			GetName(old_v->string_id & 0x7FF, vehicle_name);

		}

	}

	// sell the engine/ find out how much you get for the old engine