The default drawing style is GL_QUADS or | draw quad (.
The drawing style for | draw fill ( is GL_POLYGON.
There is a difference between the two, so use whichever one is more appropriate. There is no coding error in GEM as far as I can tell.
the difference i can see :-), allthough it might be not a bug it is inconsistent as different geos have different behaviours and with some of the handrolled its not possible to switch back to GL_QUADS once draw fill is used.
but thx for pointing out the difference so i can change this locally until a solution is found.
cheers
erich