Zero-length subpaths can neither be imported nor drawn

Inkscape does not allow to draw paths consisting of only one point at all. Also such a path will be cropped from an opened svg.

Zero-length subpaths make sense when stroke-linecap="round" (see spec below).

http://launchpadlibrarian.net/10577751/roundbug1.svg [1] should be rendered as two black circles. The right circle still isn't shown or loaded into Inkscape. It displays correctly in Firefox 4.0b7.

From the Spec of SVG 1.1 (http://www.w3.org/TR/SVG11/painting.html#StrokeProperties):
A subpath (see Paths) consisting of a single moveto shall not be stroked. Any zero length subpath shall not be stroked if the 'stroke-linecap’ property has a value of butt but shall be stroked if the ‘stroke-linecap’ property has a value of round or square, producing respectively a circle or a square centered at the given point. Examples of zero length subpaths include 'M 10,10 L 10,10', 'M 20,20 h 0', 'M 30,30 z' and 'M 40,40 c 0,0 0,0 0,0'.

And from the Implementation Notes in the Spec of SVG 1.1 (http://www.w3.org/TR/SVG11/implnote.html#PathElementImplementationNotes°):
If ‘stroke-linecap’ is set to butt and the given path segment has zero length, do not draw the linecap for that segment; however, do draw the linecap for zero-length path segments when ‘stroke-linecap’ is set to either round or square. (This allows round and square dots to be drawn on the canvas.)

[1] related reports (ATM closed as 'Fix released' and 'Invalid'):
Bug #166298 “zero-length subpaths with round linecaps are not rendered”
Bug #166306 “Closepaths are bad implemented”