[Gmsh] extrude OpenCASCADE Boolean union doesn't work

[Nico Schlömer]

Hi everyone,

The following code forms a union of a rectangle and two disks, and aims to
extrude the resulting shape.
```
SetFactory("OpenCASCADE");

Mesh.CharacteristicLengthMin = 0.1;
Mesh.CharacteristicLengthMax = 0.1;

s0 = news;
Rectangle(s0) = {-1.0, -1.0, 0.0, 2.0, 2.0};

s1 = news;
Disk(s1) = {-1.0, 0.0, 0.0, 0.5};

s2 = news;
Disk(s2) = {1.0, 0.0, 0.0, 0.5};

bo1[] = BooleanUnion{Surface {s0}; Delete;} {Surface {s1,s2}; Delete;};

ex1[] = Extrude{0,0,1}{Surface{bo1};};
```
However, it appears that only the _difference_ between the rectangle and
the disks is extruded.

Any idea what's going on?

Cheers,
Nico
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://onelab.info/pipermail/gmsh/attachments/20170927/93d8a4f7/attachment.html>