pickFromRay or drillPickFromRay Can only be executed once successfully

pickFromRay or drillPickFromRay Can only be executed once successfully, the second time will die in a while loop
this is the test code:
`
function PointVsibilityAnalysis () {
var positions = [];
var pointsEntity = [];
var vaHandler = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas);
vaHandler.setInputAction(function (movement) {
var cartesian = viewer.scene.pickPosition(movement.position);
var cartographic = Cesium.Ellipsoid.WGS84.cartesianToCartographic(cartesian);
var lng = Cesium.Math.toDegrees(cartographic.longitude);
var lat = Cesium.Math.toDegrees(cartographic.latitude);

var height = cartographic.height;
height = height < 0 ? 0 : height;
cartesian = Cesium.Cartesian3.fromDegreesArrayHeights([lng, lat, height])[0];
var point = viewer.entities.add({
position: cartesian,
point: {
pixelSize: 5,
color: Cesium.Color.RED,
outlineColor: Cesium.Color.WHITE,
outlineWidth: 2,
heightReference: Cesium.HeightReference.none
}
});
pointsEntity.push(point);
positions.push(cartesian);
if (positions.length == 2) {
vaHandler.destroy();
vaHandler = null;
var drillPick = true;
var obj2Excute = pointsEntity;

var start = positions[0];
var end = positions[1];
var direction = Cesium.Cartesian3.normalize(Cesium.Cartesian3.subtract(end, start, new Cesium.Cartesian3()), new Cesium.Cartesian3());
var ray = new Cesium.Ray(start, direction);
var results = [];
if (drillPick) {
results = viewer.scene.drillPickFromRay(ray, 10, obj2Excute);
}
else {
var result = viewer.scene.pickFromRay(ray, obj2Excute);
if (Cesium.defined(result)) {
results = [result];
}
}
if (results.length != 0) {
var vEntity = viewer.entities.add({
position: results[0].position,
point: {
pixelSize: 5,
color: Cesium.Color.YELLOW,
outlineColor: Cesium.Color.RED,
outlineWidth: 1,
heightReference: Cesium.HeightReference.none,
disableDepthTestDistance: Number.POSITIVE_INFINITY
}
});
positions.splice(1, 0, results[0].position);
var options = {
polyline: {
show: true,
positions: [positions[0], positions[1]],
material: Cesium.Color.BLUE,
width: 3
}
};
var vBlueEntity = viewer.entities.add(options);
var options2 = {
polyline: {
show: true,
positions: [positions[1], positions[2]],
material: Cesium.Color.RED,
width: 3
}
};
var vRedEntity = viewer.entities.add(options2);
}
}

}, Cesium.ScreenSpaceEventType.LEFT_CLICK);`

Start by reproducing the supplied PointVsibilityAnalysis example and compare the first and second calls to scene.pickFromRay or scene.drillPickFromRay. Focus on the ray-picking path and its handling of the supplied entities; done means repeated executions return or complete normally instead of remaining in a while loop.

Written by the indexing model from the issue text.