Cherry-pick - Fix the crash of routeRemainingDistancesIndex after reroute. (#3896)

CHANGELOG.md

@@ -31,6 +31,7 @@
 * Fixed an issue where `UserPuckCourseView`’s color desaturated during turn-by-turn navigation even as the location was being updated. ([#3836](https://github.com/mapbox/mapbox-navigation-ios/pull/3836))
 * Fixed an issue where the `PassiveLocationManager(directions:systemLocationManager:eventsManagerType:userInfo:datasetProfileIdentifier:)` initializer’s `datasetProfileIdentifier` argument was ignored. ([#3867](https://github.com/mapbox/mapbox-navigation-ios/pull/3867))
 * Fixed an issue where the user location was sometimes snapped to a parallel street just before it merges with the actual street. ([#3862](https://github.com/mapbox/mapbox-navigation-ios/pull/3862))
+* Fix the possible crash after rerouting when `routeLineTracksTraversal` enabled. ([#3896](https://github.com/mapbox/mapbox-navigation-ios/pull/3896))
 
 ### Routing
 

Sources/MapboxNavigation/NavigationMapView+VanishingRouteLine.swift

@@ -85,7 +85,7 @@ extension NavigationMapView {
         if currentStepProgress.distanceTraveled <= 0 {
             allRemainingPoints += currentLegSteps[currentLegProgress.stepIndex].dropLast().count
         } else if let startIndex = lineString.indexedCoordinateFromStart(distance: currentStepProgress.distanceTraveled)?.index,
-                  startIndex < lineString.coordinates.endIndex - 1 {
+                  lineString.coordinates.indices.contains(startIndex) {
             allRemainingPoints += lineString.coordinates.suffix(from: startIndex + 1).dropLast().count
         }
 
@@ -154,7 +154,7 @@ extension NavigationMapView {
     func updateFractionTraveled(coordinate: CLLocationCoordinate2D) {
         guard let granularDistances = routeLineGranularDistances,
               let index = routeRemainingDistancesIndex,
-              index < granularDistances.distanceArray.endIndex else { return }
+              granularDistances.distanceArray.indices.contains(index) else { return }
         let traveledIndex = granularDistances.distanceArray[index]
         let upcomingPoint = traveledIndex.point
 

Tests/MapboxNavigationTests/VanishingRouteLineTests.swift

@@ -64,6 +64,30 @@ class VanishingRouteLineTests: TestCase {
         return routeProgress
     }
 
+    func getEmptyRoute() -> Route {
+        let route = getRoute()
+        let routeLeg = route.legs.first!
+        let emptySteps = routeLeg.steps.map { (routeStep: RouteStep) -> RouteStep in
+            routeStep.shape?.coordinates = []
+            return routeStep
+        }
+        let emptyLeg = RouteLeg(steps: emptySteps,
+                                name: routeLeg.name,
+                                distance: routeLeg.distance,
+                                expectedTravelTime: routeLeg.expectedTravelTime,
+                                profileIdentifier: routeLeg.profileIdentifier)
+        let emptyRoute = Route(legs: [emptyLeg], shape: route.shape, distance: route.distance, expectedTravelTime: route.expectedTravelTime)
+        return emptyRoute
+    }
+
+    func getUnstartedRouteProgress(route: Route) -> RouteProgress {
+        let routeProgress = RouteProgress(route: route, options: routeOptions, legIndex: 0, spokenInstructionIndex: 0)
+        routeProgress.currentLegProgress = RouteLegProgress(leg: route.legs[0], stepIndex: 0, spokenInstructionIndex: 0)
+        routeProgress.currentLegProgress.currentStepProgress = RouteStepProgress(step: route.legs[0].steps[0], spokenInstructionIndex: 0)
+        routeProgress.currentLegProgress.currentStepProgress.distanceTraveled = 0.0
+        return routeProgress
+    }
+
     func lineGradientToString(lineGradient: Value<StyleColor>?) -> String {
         guard let halfStringFromLineGradient = lineGradient.debugDescription.components(separatedBy: "(").last,
               let stringFromLineGradient = halfStringFromLineGradient.components(separatedBy: ")").first else {
@@ -142,6 +166,35 @@ class VanishingRouteLineTests: TestCase {
         XCTAssertEqual(navigationMapView.fractionTraveled, expectedFractionTraveled, accuracy: 0.0000000001)
     }
 
+    func testEmptyRouteWithValidRouteProgress() {
+        let routeProgress = getRouteProgress()
+        let route = getEmptyRoute()
+
+        let coordinate = CLLocationCoordinate2DMake(-122.5237429, 37.975393)
+        navigationMapView.routeLineTracksTraversal = true
+        navigationMapView.show([route])
+        navigationMapView.updateUpcomingRoutePointIndex(routeProgress: routeProgress)
+        navigationMapView.updateFractionTraveled(coordinate: coordinate)
+
+        // Route without coordinates inside its steps would lead to invalid routeRemainingDistancesIndex.
+        XCTAssertEqual(navigationMapView.routeRemainingDistancesIndex, -1)
+        XCTAssertEqual(navigationMapView.fractionTraveled, 0.0, accuracy: 0)
+    }
+
+    func testUnstartedRouteProgressWithValidRoute() {
+        let route = getRoute()
+        let routeProgress = getUnstartedRouteProgress(route: route)
+
+        let coordinate = CLLocationCoordinate2DMake(-122.5237429, 37.975393)
+        navigationMapView.routeLineTracksTraversal = true
+        navigationMapView.show([route])
+        navigationMapView.updateUpcomingRoutePointIndex(routeProgress: routeProgress)
+        navigationMapView.updateFractionTraveled(coordinate: coordinate)
+
+        XCTAssert(navigationMapView.routeRemainingDistancesIndex! >= 0, "Non-empty route should have valid routeRemainingDistancesIndex.")
+        XCTAssertEqual(navigationMapView.fractionTraveled, 0.0, accuracy: 0)
+    }
+
     func disabled_UpdateRouteLineWithDifferentDistance() {
         let routeProgress = getRouteProgress()
         let route = routeProgress.route