GeoJSON renders incorrectly with default Rhumb arc type

I’m using Cesium 1.60.0 and trying to load GeoJSON describing borders of Russia. I extracted this GeoJSON from shape files found on NaturalEarth (1:50m resolution, cultural). Unfortunately, Cesium does something wrong while rendering the GeoJSON. Seems like it draws polygon lines between points that should not be connected with each other.

I report this issue because this GeoJSON is displayed as expected with another software such as QGIS.

Sandcastle example

var viewer = new Cesium.Viewer('cesiumContainer');
viewer.dataSources.add(Cesium.GeoJsonDataSource.load('https://gist.githubusercontent.com/ezze/98a77f60cab8d24613f440599bece3a5/raw/9ac4498a1f0d3f3c80792a73a52672f1c847f43d/russia.json'));

Cesium doesn’t display GeoJSON properly

QGIS displays GeoJSON as expected

geojson.io displays GeoJSON as expected

mapshaper.org displays GeoJSON as expected

Browser: Chromium Version 75.0.3770.142 (Official Build) Built on Ubuntu , running on Ubuntu 18.04 (64-bit)

Operating System: Kubuntu 18.04

[likangning93]

For anyone who wants to do some close reading, here’s the relevant section of the spec linked at the PR referenced above: https://tools.ietf.org/html/rfc7946#section-3.1.1

   A line between two positions is a straight Cartesian line, the
   shortest line between those two points in the coordinate reference
   system (see Section 4).

   In other words, every point on a line that does not cross the
   antimeridian between a point (lon0, lat0) and (lon1, lat1) can be
   calculated as

   F(lon, lat) = (lon0 + (lon1 - lon0) * t, lat0 + (lat1 - lat0) * t)

   with t being a real number greater than or equal to 0 and smaller
   than or equal to 1.  Note that this line may markedly differ from the
   geodesic path along the curved surface of the reference ellipsoid.

   The same applies to the optional height element with the proviso that
   the direction of the height is as specified in the coordinate
   reference system.

   Note that, again, this does not mean that a surface with equal height
   follows, for example, the curvature of a body of water.  Nor is a
   surface of equal height perpendicular to a plumb line.

[OmarShehata]

This may due to the same issue as https://github.com/AnalyticalGraphicsInc/cesium/issues/7864. Try this Sandcastle which sets the arc type back to what it used to be. Let me know if this looks correct.