Comment 13 for bug 1098283

I agree that the last path is mathematically redundant. However, this is a behaviour that is common to all the Python-based extensions that do path manipulation in Inkscape, so it is not feasible to modify this behaviour. (And, of course, it does not do any harm to have a redundant node present.)
    In the original svg notation, the last path is repesented by a 'z' or a 'Z'. When this is converted into a path notation that is useable by the Python extensions, it gets converted into what is called a cubicsuperpath notation using a Python file with the name cubicsuperpath.py, where the cubic refers to cubic Bezier curves, and the superpath refers to the fact that it can represent either Bezier curves or straight lines, and that they can be either disjoint or contiguous, and also either smooth or cusp. In this superpath notation the term 'z' or 'Z' does not exist, and so it is replaced by writing the last node explicitly. In any event, this notation is fundamental to the operation of the Python extensions, so it is not feasible to modify it.