Segfault when meshing a difference

[Former user]

I am experiencing a segfault when trying to generate_mesh on a difference. Here is a snippet

    mshr::Rectangle channel(Point(0,0,0),Point(L,H,0));
    mshr::Circle obstacle(Point(xc,yc,0),r);
    std::shared_ptr<mshr::CSGDifference> shedding = channel - obstacle;
    std::shared_ptr<Mesh> mesh = mshr::generate_mesh(*shedding,resolution);

Meshing channel or obstacle works fine.

[Benjamin Dam Kehlet]

Confirmed. Thanks for reporting!

I don't have time until Thursday or Friday this week, but I will take a look then.

[Jan Blechta]

Following code also segfaults with current master (02ffef1bbfce52721bae920de7d362ac4e4b57dd)

from dolfin import *
import mshr

center = Point(0.2, 0.2)
radius = 0.05
L = 2.2
W = 0.41
geometry = mshr.Rectangle(Point(0.0, 0.0), Point(L, W)) \
         - mshr.Circle(center, radius, 40)
mesh = mshr.generate_mesh(geometry, 50)

[Former user]

Is that Turek's benchmark? That's the same I was trying :D

[Jan Blechta]

Sure:D We have used it in an introductory FEniCS tutorial.

[Former user]

@blechta your code crashes because the radius is too big. I set it to 10 and it works on my machine. Also the code from the tutorial works just fine. It's quite odd that the C++ version is broken and the Python one is not :S

[Former user]

Sorry, not the radius, the third parameter, the segment number for the circle :D I put it to 10 and it worked.

My code also seems to be working now, so the bug must be somewhere related to that third parameter. With 10 it works fine, but the default value is already enough to make it crash.

[Benjamin Dam Kehlet]

Merge branch 'benjamik/fix-issue-37'. Fixes issue #37.

→ <<cset 3b41e7b4b7ec>>

[Former user]

Fix confirmed, thanks!