System information

• SolveSpace version:
  3.0~0e0b0252
• Operating system:
  Arch Linux

Expected behavior

1. You create the triangular section.
2. You lathe it around its tip.
3. You select the sketch again, and extrude it.
4. You save it / select the extrusion, etc

Actual behavior

It crashes at 4 with:

File ./src/srf/surfinter.cpp, line 103, function AddExactIntersectionCurve:
Assertion failed: !(sb->Start()).Equals(sb->Finish()).

Additional information

Unfortunately, it crashes if you try to save it with the problematic geometry. If you extrude the first sketch though, it should crash upon the next thing you do (saving, etc).
crash.zip