Hi, I have created an SVG (attached and at https://commons.wikimedia.org/wiki/File:Vector_saturn.svg ) which demonstrates four big librsvg bugs very prominently. The file should render correctly in Inkscape.
A correctly rendered PNG can also be found on commons under the name File:Vector saturn (Correct render).png.
The bugs shown are:
1—Failure to render masks
Any masked object will disappear. Clipping works.
2—Failure to render low Gaussian blurs
Any object with a Gaussian blur which has a size of less than 1 pixel at the given display size will disappear. This is especially problematic when objects will show up blurred correctly at full size, but disappear at thumbnail size.
Not dependent on the blur size in Inkscape—for example, in Inkscape, a very small object may have a blur size of 10, but still disappear in librsvg.
3—Failure to render rotated blurred objects
If any blurred object is rotated more than 90° in either direction, it will disappear. This is not dependent on the size of the Gaussian blur.
4—Failure to correctly render blurred objects on the edges
If an object is cropped by the SVG page boundary, the Gaussian blur will be rendered after the crop is applied, creating a discontinuity.