[BUG] Exported .3mf from path_extrude2d using arc path has open edges

[jreiberkyle]

Describe the bug I generated a 3d geometry using path_extrude2d() with a path generated using arc(). I exported it as .stl and as .3mf and then imported the files into PrusaSlicer. The .stl geometry has no errors but the .3mf geometry is flagged with an "open edges" error.

Code To Reproduce Bug

include <BOSL2/std.scad>

path = arc(r=15, angle=270);
path_extrude2d(path) square(5);

Expected behavior When exported to .3mf then imported to PrusaSlicer, the mesh would not have any errors.

Screenshots If applicable, add screenshots to help explain your problem.

Additional context Add any other context about the problem here.

• BOSL @ 9c92e3ce0204e634a7446580625f6c8ed4a83140
• OpenSCAD Version: 2021.01
• Other libraries used: PrusaSlicer 2.5.0+MacOS+x64
• OS: MacOS 11.7.1

[revarbat]

This is a bug in OpenSCAD, not in BOSL2.