I use GeoDataTrack as geometry for GeoDataPlacemark to draw a plane track. After upgrade to 16.08.1 i found that i can't see any track on the globe. I used this code in my experiments to figure out what's happen:
m_pTrackCoords->addPoint(QDateTime::currentDateTime().addSecs(-600),
                         GeoDataCoordinates(34.6, 43.1, 7000, GeoDataCoordinates::Degree));
m_pTrackCoords->addPoint(QDateTime::currentDateTime().addSecs(-300),
                         GeoDataCoordinates(23.4, 43.2, 7000, GeoDataCoordinates::Degree));
m_pTrackCoords->addPoint(QDateTime::currentDateTime(),
                         GeoDataCoordinates(11.9, 42.9, 7000, GeoDataCoordinates::Degree));

// Flight track setup
m_pTrackCoords->setInterpolate(true);
m_pPlaneTrack->setGeometry(m_pTrackCoords);

GeoDataLineString *test = new GeoDataLineString;
test->append(GeoDataCoordinates(35.6, 43.1, 7000, GeoDataCoordinates::Degree));
test->append(GeoDataCoordinates(44.4, 43.2, 7000, GeoDataCoordinates::Degree));
test->append(GeoDataCoordinates(52.9, 42.9, 7000, GeoDataCoordinates::Degree));

GeoDataPlacemark *mark = new GeoDataPlacemark;
mark->setGeometry(test);

GeoDataLineStyle linestyle;
linestyle.setWidth(2);
linestyle.setColor(QColor(Qt::red));
linestyle.setPenStyle(Qt::SolidLine);

QSharedPointer<GeoDataStyle> style(new GeoDataStyle);
style->setLineStyle(linestyle);

mark->setStyle(style);
m_pTrackCoords->setStyle(style);

// Setting tracks on map
GeoDataDocument *doc = new GeoDataDocument;
doc->append(m_pPlaneTrack);
doc->append(mark);

// Map setup
m_pWidget->setMapThemeId("earth/openstreetmap/openstreetmap.dgml");
m_pWidget->model()->treeModel()->addDocument(doc);

m_pTrackCoords is a pointer to GeoDataTrack object, m_pPlainTrack is a pointer to GeoDataPlacemark object and m_pWidget is a pointer to MarbleWidget. At version 16.04.3, both lines are visible, but at version 16.08.1 only GeoDataLineString line is shown, and GeoDataTrack line is not

Reproducible: Always

Steps to Reproduce:
1. Create instance of GeoDataTrack class (track);
2. Add a few points to track;
3. Create instance of GeoDataPlacemark class (placemark);
4. Set track as placemarks geometry using setGeometry();
5. (optional) Set placemark style;
6. Add placemark to document;
7. Add document to treeModel().

Actual Results:  
Nothing

Expected Results:  
A line going through the given points