Strange Inkscape path behaviour - is this normal or a bug?

Question

I'm trying to figure out if this is a bug I should report, or whether it's normal behaviour. (I don't think it is normal, but would appreciate others' thoughts)

I've created a simple triangle path on Inkscape, but when I drag handles to adjust a line's curves, nothing at all happens to the stroke of the shape - that's the black line in the image below. The red line shows the path's outline when I enable the 'Show path outline (without path effects)' setting, which does reflect what I've been doing with the handles.

So, my question is.... is there any scenario in which this should happen in Inkscape? Or is it just being crackers?

Answer 1

You've made your curves with the incredible Spiro Spline. It's a glorious tool that is worth reading about: http://www.levien.com/spiro/

To draw regular curves, switch the mode it the top toolbar.

To access spiro and other path filters, see Path > Path Effect Editor...