Json.NET: Reader tries to read too much when "coordinates" is null

[airbreather]

var token = JToken.Parse("{\"type\":\"LineString\",\"coordinates\":null}");
var lineString = token.ToObject<LineString>(GeoJsonSerializer.CreateDefault());

In this situation, we will get EndOfStreamException.

The issue is that this code doesn't consider the possibility that we might be on a null token:

NetTopologySuite.IO.GeoJSON/src/NetTopologySuite.IO.GeoJSON/Converters/GeometryConverter.cs

Lines 354 to 357 in 3427249

	case "coordinates":
	reader.ReadOrThrow(); //read past start array tag
	coords = ReadCoordinates(reader);
	break;

As it turns out, 4STJ actually does write out null to signal an empty geometry, as shown in the longer repro below, which effectively means that the Json.NET version doesn't interoperate properly with the 4STJ version 😞:

var stjOptions = new System.Text.Json.JsonSerializerOptions
{
    Converters = { new NetTopologySuite.IO.Converters.GeoJsonConverterFactory() },
};

var seq = GeometryFactory.Default.CoordinateSequenceFactory.Create(0, 2);
var lineString = GeometryFactory.Default.CreateLineString(seq);
string s = System.Text.Json.JsonSerializer.Serialize(lineString, stjOptions);

var jsonNetSerializer = NetTopologySuite.IO.GeoJsonSerializer.CreateDefault();
var jsonNetToken = Newtonsoft.Json.Linq.JToken.Parse(s);
var roundTrip = jsonNetToken.ToObject<LineString>(jsonNetSerializer);