Bug with GTFS flex data and StreetTransitLinks

[Joe Celano]

I am running OTP 1.5 with some GTFS flex data, and it kept throwing a  java.util.NoSuchElementException thrown when trying to start OTP.   The error stack is like this:

19:54:04.746 INFO (FlexIndex.java:40) initializing hops-for-edge map...

19:54:06.625 INFO (FlexIndex.java:57) Finding corresponding street edges for trip patterns...

Exception in thread "main" java.util.NoSuchElementException

        at java.base/java.util.TreeMap$PrivateEntryIterator.nextEntry(TreeMap.java:1206)

        at java.base/java.util.TreeMap$ValueIterator.next(TreeMap.java:1253)

        at org.opentripplanner.routing.flex.FlexIndex.findClosestEdges(FlexIndex.java:129)

        at org.opentripplanner.routing.flex.FlexIndex.initializeHopsForEdgeMap(FlexIndex.java:72)

        at org.opentripplanner.routing.flex.FlexIndex.init(FlexIndex.java:41)

        at org.opentripplanner.routing.graph.Graph.setUseFlexService(Graph.java:1089)

        at org.opentripplanner.standalone.Router.startup(Router.java:160)

        at org.opentripplanner.routing.impl.MemoryGraphSource.reload(MemoryGraphSource.java:55)

        at org.opentripplanner.routing.services.GraphService.registerGraph(GraphService.java:183)

        at org.opentripplanner.standalone.OTPMain.run(OTPMain.java:109)

        at org.opentripplanner.standalone.OTPMain.main(OTPMain.java:73)

I tracked the error down and it looks like this is the code in FlexIndex.java that has a bug,

Collection<Edge> edges = graph.streetIndex.getEdgesForEnvelope(env);

if (edges.isEmpty()) {

    return Collections.emptyList();

}

Map<Double, List<StreetEdge>> edgeDistanceMap = new TreeMap<>();

for(Edge edge : edges){

    if(edge instanceof StreetEdge){

        LineString line = edge.getGeometry();

        double dist = SphericalDistanceLibrary.fastDistance(pointLocation, line);

        double roundOff = (double) Math.round(dist * 100) / 100;

        if(!edgeDistanceMap.containsKey(roundOff))

            edgeDistanceMap.put(roundOff, new ArrayList<>());

        edgeDistanceMap.get(roundOff).add((StreetEdge) edge);

    }

}

List<Edge> closestEdges = edgeDistanceMap.values().iterator().next()

        .stream().map(e -> (Edge) e).collect(Collectors.toList());

return closestEdges;

Because edgeDistanceMap is empty, b/c the edges are all StreetTransitLink and not StreetEdge objects.  I think a fix would be top change the last few lines to:

if(!edgeDistanceMap.isEmpty()) {

    List<Edge> closestEdges = edgeDistanceMap.values().iterator().next()

            .stream().map(e -> (Edge) e).collect(Collectors.toList());

    return closestEdges;

}

else{

    return new ArrayList<>(edges);

}

Does this look about right for a fix?  Or is this a problem with the flex data?