Can anybody please elaborate on QGIS' topology considering shared vertices of the type depicted in my screen cast?
The polygon in the picture is the same feature, with one node being shared at exactly the same position, without overlapping, leading to an intersection of the line-segments.
I assume this is supposed to be an invalid geometry, however I think it shouldn't.
How to get around this, if I want to retain the position of both vertices??
ps: WKT (sorry for the long one..) https://drive.google.com/open?id=0B2wAunwURQNsc1J4bS15WVBNSmM