(svn r25698) -Fix [FS#5700]: Autoreplace/renew also refits free wagons.

src/train_cmd.cpp

@@ -418,7 +418,7 @@ int Train::GetCurrentMaxSpeed() const
 /** Update acceleration of the train from the cached power and weight. */
 void Train::UpdateAcceleration()
 {
-	assert(this->IsFrontEngine());
+	assert(this->IsFrontEngine() || this->IsFreeWagon());
 
 	uint power = this->gcache.cached_power;
 	uint weight = this->gcache.cached_weight;

src/vehicle_cmd.cpp

@@ -447,11 +447,12 @@ CommandCost CmdRefitVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint
 	if (ret.Failed()) return ret;
 
 	bool auto_refit = HasBit(p2, 6);
+	bool free_wagon = v->type == VEH_TRAIN && Train::From(front)->IsFreeWagon(); // used by autoreplace/renew
 
 	/* Don't allow shadows and such to be refitted. */
 	if (v != front && (v->type == VEH_SHIP || v->type == VEH_AIRCRAFT)) return CMD_ERROR;
 	/* Allow auto-refitting only during loading and normal refitting only in a depot. */
-	if ((!auto_refit || !front->current_order.IsType(OT_LOADING)) && !front->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAIN_MUST_BE_STOPPED_INSIDE_DEPOT + front->type);
+	if (!free_wagon && (!auto_refit || !front->current_order.IsType(OT_LOADING)) && !front->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAIN_MUST_BE_STOPPED_INSIDE_DEPOT + front->type);
 	if (front->vehstatus & VS_CRASHED) return_cmd_error(STR_ERROR_VEHICLE_IS_DESTROYED);
 
 	/* Check cargo */
@@ -490,9 +491,11 @@ CommandCost CmdRefitVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint
 		}
 		front->MarkDirty();
 
-		InvalidateWindowData(WC_VEHICLE_DETAILS, front->index);
+		if (!free_wagon) {
+			InvalidateWindowData(WC_VEHICLE_DETAILS, front->index);
+			InvalidateWindowClassesData(GetWindowClassForVehicleType(v->type), 0);
+		}
 		SetWindowDirty(WC_VEHICLE_DEPOT, front->tile);
-		InvalidateWindowClassesData(GetWindowClassForVehicleType(v->type), 0);
 	} else {
 		/* Always invalidate the cache; querycost might have filled it. */
 		v->InvalidateNewGRFCacheOfChain();