MapboxDirections returns route with no steps causing MapRouteLine crash

I'm migrating from Navigation SDK 0.42.3 to 1.5.1 and I'm getting problems with requesting a route. I switched from NavigationRoute class to MapboxDirections class as NavigationRoute was removed. You can find more details on implementation at the end of issue description.

Steps to trigger behavior

1. Request route via MapboxDirections.builder()
2. In onResponse() callback provided in enqueueCall() method of MapboxDirections.builder() pass the route to NavigationMapRoute.addRoute()
3. Observe the crash and check logs

Here are route details:

DirectionsRoute{routeIndex=0, distance=3547.207, duration=389.967, durationTypical=null, geometry=yfyipAzvsw}Cp@bJun@`{@glA}e@o~Cli@gXig_@oKcmBmjCr@}oJ{d@f@|u@faBcRfRd[pCfvB`O]LlMe_@f@, weight=1754.069, weightName=auto, legs=[RouteLeg{distance=3547.207, duration=389.967, durationTypical=null, summary=Featherstone Road, Chrysler Drive, admins=[Admin{countryCode=US, countryCodeAlpha3=USA}], steps=[], incidents=null, annotation=null}], routeOptions=RouteOptions{baseUrl=https://api.mapbox.com, user=mapbox, profile=driving, coordinates=[Point{type=Point, bbox=null, coordinates=[-83.24126434326172, 42.64449691772461]}, Point{type=Point, bbox=null, coordinates=[-83.22702026367188, 42.65614318847656]}], alternatives=null, language=null, radiuses=null, bearings=null, continueStraight=null, roundaboutExits=null, geometries=polyline6, overview=null, steps=null, annotations=null, exclude=null, voiceInstructions=null, bannerInstructions=null, voiceUnits=imperial, accessToken=<token-here>, approaches=null, waypointIndices=null, waypointNames=null, waypointTargets=null, walkingOptions=null}, voiceLanguage=null}

Expected behavior

Route from MapboxDirections should be displayed in NavigationMapRoute without other manipulation or if it was not possible to provide a route there should be some error handling mechanism which don't cause crash of Map SDK.
It should work as before, i.e. in the old SDK version request created for the same origin and destination with NavigationRoute returns a route with one leg containing 12 steps.

Actual behavior

1970-01-01 01:02:22.267 7607-7607/<package-hidden> E/AndroidRuntime: FATAL EXCEPTION: main
    Process: de.conti.r2d2.mapboxnavigation, PID: 7607
    java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
        at java.util.ArrayList.get(ArrayList.java:437)
        at com.mapbox.navigation.ui.route.MapRouteLine$MapRouteLineSupport.buildWayPointFeatureFromLeg(MapRouteLine.kt:1607)
        at com.mapbox.navigation.ui.route.MapRouteLine$MapRouteLineSupport.buildWayPointFeatureCollection(MapRouteLine.kt:1584)
        at com.mapbox.navigation.ui.route.MapRouteLine.drawWayPoints(MapRouteLine.kt:888)
        at com.mapbox.navigation.ui.route.MapRouteLine.reinitializeWithRoutes(MapRouteLine.kt:591)
        at com.mapbox.navigation.ui.route.MapRouteLine.draw(MapRouteLine.kt:554)
        at com.mapbox.navigation.ui.route.NavigationMapRoute.addRoutes(NavigationMapRoute.java:221)
        at com.mapbox.navigation.ui.route.NavigationMapRoute.addRoute(NavigationMapRoute.java:200)
        at <package-hidden>.RouteViewModel$2.onResponse(RouteViewModel.java:304)
        at com.mapbox.api.directions.v5.MapboxDirections$1.onResponse(MapboxDirections.java:186)
        at retrofit2.DefaultCallAdapterFactory$ExecutorCallbackCall$1.lambda$onResponse$0$DefaultCallAdapterFactory$ExecutorCallbackCall$1(DefaultCallAdapterFactory.java:81)
        at retrofit2.-$$Lambda$DefaultCallAdapterFactory$ExecutorCallbackCall$1$3wC8FyV4pyjrzrYL5U0mlYiviZw.run(Unknown Source:6)
        at android.os.Handler.handleCallback(Handler.java:883)
        at android.os.Handler.dispatchMessage(Handler.java:100)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7356)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
1970-01-01 01:02:22.294 7607-7607/<package-hidden> I/Process: Sending signal. PID: 7607 SIG: 9

More details on implementation

Here is the diff of changes I made when migrating from Navigation SDK 0.42.3 to 1.5.1.

@@ -249,20 +250,22 @@ public class RouteViewModel extends AndroidViewModel {
     /**
      * Send route request to Mapbox's server
      */
-     public void getRoute(MapView mapView, MapboxMap mapboxMap) {
+     public void getRoute(MapView mapView, MapboxMap mapboxMap, LifecycleOwner lifecycleOwner) {
         try { 
             if (startPoint.getValue() != null && destinationPoint.getValue() != null) {
-                NavigationRoute.builder(getApplicationContext())
+                MapboxDirections.builder()
                         .accessToken(getApplicationContext().getString(R.string.mapbox_token))
                         .origin(startPoint.getValue())
                         .destination(destinationPoint.getValue())
                         .profile(DirectionsCriteria.PROFILE_DRIVING)
                         .voiceUnits(DirectionsCriteria.IMPERIAL)
                         .build()
-                        .getRoute(new Callback<DirectionsResponse>() {
+                        .enqueueCall(new Callback<DirectionsResponse>() {
                             @Override
                             public void onResponse(Call<DirectionsResponse> call, Response<DirectionsResponse> response) {
                                 // You can get the generic HTTP info about the response
@@ -283,7 +286,10 @@ public class RouteViewModel extends AndroidViewModel {

                                 // Draw the route on the map
                                 if (navigationMapRoute == null) {
-                                    navigationMapRoute = new NavigationMapRoute(null, mapView, mapboxMap, R.style.NavigationMapRoute);
+                                    navigationMapRoute = new NavigationMapRoute.Builder(
+                                            mapView, mapboxMap, lifecycleOwner)
+                                            .withStyle(R.style.NavigationMapRoute)
+                                            .build();
                                 }
                                 navigationMapRoute.addRoute(currentRoute.getValue());    // << this call is in stacktrace (RouteViewModel.java:304)
                                 showProgressBar.setValue(false);

Inizia dal percorso dello stack trace di MapRouteLine.kt, quindi esamina NavigationMapRoute.java e la chiamata a addRoute() di RouteViewModel.java mostrata nel report. Confronta il modo in cui MapboxDirections.builder() costruisce il percorso con la richiesta precedente di NavigationRoute. Il lavoro è completato quando un percorso con un elenco steps vuoto non causa più il crash di NavigationMapRoute e il percorso segnalato viene visualizzato o gestito senza un crash dell’SDK.