Don't use occupancy of unload and leave empty orders for occupancy average

src/order_base.h

@@ -563,6 +563,8 @@ public:
 	 */
 	inline void SetOccupancy(uint8 occupancy) { this->occupancy = occupancy; }
 
+	bool UseOccupancyValueForAverage() const;
+
 	bool ShouldStopAtStation(StationID last_station_visited, StationID station, bool waypoint) const;
 	bool ShouldStopAtStation(const Vehicle *v, StationID station, bool waypoint) const;
 	bool CanLeaveWithCargo(bool has_cargo, CargoID cargo) const;

src/order_cmd.cpp

@@ -3556,6 +3556,19 @@ bool ProcessOrders(Vehicle *v)
 	return UpdateOrderDest(v, order) && may_reverse;
 }
 
+bool Order::UseOccupancyValueForAverage() const
+{
+	if (this->GetOccupancy() == 0) return false;
+	if (this->GetOccupancy() > 1) return true;
+
+	if (this->IsType(OT_GOTO_STATION)) {
+		OrderUnloadFlags unload_type = this->GetUnloadType();
+		if ((unload_type == OUFB_TRANSFER || unload_type == OUFB_UNLOAD) && this->GetLoadType() == OLFB_NO_LOAD) return false;
+	}
+
+	return true;
+}
+
 /**
  * Check whether the given vehicle should stop at the given station
  * based on this order and the non-stop settings.

src/order_gui.cpp

@@ -2381,7 +2381,13 @@ public:
 			uint8 occupancy = order->GetOccupancy();
 			if (occupancy > 0) {
 				SetDParam(0, occupancy - 1);
-				DrawString(ir.left, ir.right, y, STR_ORDERS_OCCUPANCY_PERCENT, (i == this->selected_order) ? TC_WHITE : TC_BLACK);
+				TextColour colour;
+				if (order->UseOccupancyValueForAverage()) {
+					colour = (i == this->selected_order) ? TC_WHITE : TC_BLACK;
+				} else {
+					colour = ((i == this->selected_order) ? TC_SILVER : TC_GREY) | TC_NO_SHADE;
+				}
+				DrawString(ir.left, ir.right, y, STR_ORDERS_OCCUPANCY_PERCENT, colour);
 			}
 			y += line_height;
 

src/vehicle.cpp

@@ -3503,8 +3503,9 @@ void Vehicle::RecalculateOrderOccupancyAverage()
 	uint total = 0;
 	uint order_count = this->GetNumOrders();
 	for (uint i = 0; i < order_count; i++) {
-		uint occupancy = this->GetOrder(i)->GetOccupancy();
+		const Order *order = this->GetOrder(i);
-		if (occupancy > 0) {
+		uint occupancy = order->GetOccupancy();
+		if (occupancy > 0 && order->UseOccupancyValueForAverage()) {
 			num_valid++;
 			total += (occupancy - 1);
 		}