Problem with "subtract()"ing "hull()", is this a bug?

Hermann-SW

For drawing a spherical triangle I need to draw 2 "sp_tria2()"s in that triangle on the sphere. "sp_tria2()" might overshoot sphere triangle borders as here:

Next I create "hull()" from 6 points (found no way to do that, created "hull()" of 6 very small "cube()"s instead), the 3 triangle coordinates, and those coordinates scaled up to that "hull()" completely contains the wanted triangle part of "sp_tria2()":

Here is hull definition:

        h =            hull(
                           cube({center: sv1, size: 0.01})
                           ,cube({center: sv2, size: 0.01})
                           ,cube({center: sv3, size: 0.01})
                           ,cube({center: s1, size: 0.01})
                           ,cube({center: s2, size: 0.01})
                           ,cube({center: s3, size: 0.01})
                       )

Why does "subtract()" not work when subtracting "h"?
(subtract does work for look_inside=yes, subtracting sphere and cube from outer sphere)
Here is link for you to play with:
https://openjscad.xyz/?uri=https://stamm-wilbrandt.de/en/forum/Q.JSCAD.vertex_edge2.sp_tria.js

...
        return colorize([0.5,0.5,0.5],
                     subtract(
                        translate([0,0,0],
                                  rotate([0,0,la1-degToRad(180)],
                                         rotate([0,ph1-degToRad(90),0],
                                                rotate([0,0,-al13],
                                                       sp_tria2(sc, s12, mpi(al13-al12), 0.1, 40, 40)
                                                      )
                                               )
                                        )
                                 )
                       ),
                       h
                     )  
...

"sp_tria(4,13,14)" call is in line 244 near the end.

Hermann-SW

Oops, too late/early, need to get more sleep.

problem was bad indentation of brackets and placing ",h" at wrong level.
problem was that I want "intersect()" and not "subtract()":

        return colorize([0.5,0.5,0.5],
                     intersect(
                        translate([0,0,0],
                                  rotate([0,0,la1-degToRad(180)],
                                         rotate([0,ph1-degToRad(90),0],
                                                rotate([0,0,-al13],
                                                       sp_tria2(sc, s12, mpi(al13-al12), 0.1, 40, 40)
                                                      )
                                               )
                                        )
                                 ),
                         h
                       )
                     )

Works like a charme now:

Hermann-SW

This post is deleted!

Hermann-SW

Forgot to post the "answer" link for viewing in browser:
https://openjscad.xyz/?uri=https://stamm-wilbrandt.de/en/forum/A.JSCAD.vertex_edge2.sp_tria.js