QGIS » QGIS Application

I have a KML file here, containing ONE big (gpx I think) line.

A windows users told me that QGIS is showing it was not editable ('edit'-pencil disabled). But with me on Linux (both 2.2 and current testing) the 'pencil' tool is active, and seems I can edit the layer.

After enabling edit, I can only add a new line (not edit the available line with the node tool).
Strange, but ok. Then I add a new line, all seems ok, but when I toggle edit mode OFF the line is not visible anymore.
BUT when I remove the kml layer (all in the same project), and add it again as layer, my newly (former invisible) line is available and visible.

This happens both in master and testing (clean 4326 project, no OTF).

Not sure if this is a bug, to me it seems that
- either editing KML should not be allowed (because a KML can contain styling which probably get's lost when you save it in QGIS) then the Windows apparently sees what he needs to see (though maybe a warning/message would be nice somewhere?),
- OR it should behave in the same way as normal vector editing,
- OR it should maybe warn me that I'm starting to edit a KML file and loosing styling, but then a newly added feature should stay visibible after addition.

To reproduce: load attached KML file and steps above.