Hi,
The currently specified fallback for the 'arcs' line join is a 'miter' join. It has be noted that this is not a very good fallback. I've implemented three different alternative fallback strategies in trunk as part of the 'Join Type' LPE in trunk. The SVG WG has agreed to change the fallback to one of these depending on user input. Here is your chance to help influence the SVG 2 specification!
For a quick introduction, see:
http://tavmjong.free.fr/SVG/LINEJOIN_STUDY/#arcs
To test:
1. Create a path with a number of corner nodes. 2. Open the LPE dialog (Path->Path Effects, CTRL-SHIFT-7) 3. Click on the '+' button, select 'Join Type', and click the 'Add' button. 4. Increase the 'Line width' to some number (~20 to ~100) 5. Select the various "Extrapolated arc" 'Join' types. 6. Move the handles around and observe the line join shape.
Note: There are a number of bugs, for example, setting the Miter limit doesn't always work. Also, if the radius of curvature of the path is very small you might get strange artifacts. For this exercise, please ignore these.
Thanks,
Tav