Assertion Nef_3

[gdamiand]

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Issue Details

The following code raise an assertion.

Source Code

surface_mesh_kernel.txt
data.zip

Environment

• Operating system (Windows/Mac/Linux, 32/64 bits): Ubuntu 24.04
• Compiler: g++ 13.2.0
• Release or debug mode: debug
• CGAL version: master branch

[afabri]

I turned this into PR #8646 without fix.

[afabri]

What assertion do you have? When I run the executable in the PR I get th output below without assertion.

andre@motherwell /cygdrive/c/GitHub/cgal/Nef_3/test/Nef_3
$ ./build/Debug/issue8644
0 0  0 0  0 -1  0 1
0 1  0 0  0 0  0 -3/2
0 0  0 -1  0 0  0 3
0 -1  0 0  0 0  0 3
0 0  0 1  0 0  0 3
0 1  0 0  0 0  0 3
0 0  0 -1  0 0  0 -3/2
0 0  0 0  0 1  0 1
[./data/lshape1_dim3.off]: empty kernel.
0 0  0 0  0 1  0 -1
0 -1  0 0  0 0  0 3/2
0 0  0 1  0 0  0 -3
0 1  0 0  0 0  0 -3
0 0  0 -1  0 0  0 -3
0 -1  0 0  0 0  0 -3
0 0  0 1  0 0  0 3/2
0 0  0 0  0 -1  0 -1
[./data/lshape1_dim3.off]: NON empty kernel.
0 -1  0 0  0 0  0 -3
0 0  0 0  0 -1  0 -1
0 0  0 -1  0 0  0 -3
0 0  0 0  0 1  0 -1
0 0  0 1  0 0  0 3/2
0 -1  0 0  0 0  0 3/2
0 0  0 -1  0 0  0 3/2
0 -1  0 0  0 0  0 -3
0 0  0 1  0 0  0 -3
0 1  0 0  0 0  0 -3
[./data/ushape1_dim3.off]: empty kernel.
0 1  0 0  0 0  0 3
0 0  0 0  0 1  0 1
0 0  0 1  0 0  0 3
0 0  0 0  0 -1  0 1
0 0  0 -1  0 0  0 -3/2
0 1  0 0  0 0  0 -3/2
0 0  0 1  0 0  0 -3/2
0 1  0 0  0 0  0 3
0 0  0 -1  0 0  0 3
0 -1  0 0  0 0  0 3
[./data/ushape1_dim3.off]: empty kernel.

[gdamiand]

Result using your branch PR #8646

./issue8644
0 0 0 0 0 -1 0 1
0 1 0 0 0 0 0 -3/2
0 0 0 -1 0 0 0 3
0 -1 0 0 0 0 0 3
0 0 0 1 0 0 0 3
0 1 0 0 0 0 0 3
0 0 0 -1 0 0 0 -3/2
0 0 0 0 0 1 0 1
[./data/lshape1_dim3.off]: empty kernel.
0 0 0 0 0 1 0 -1
0 -1 0 0 0 0 0 3/2
0 0 0 1 0 0 0 -3
0 1 0 0 0 0 0 -3
0 0 0 -1 0 0 0 -3
0 -1 0 0 0 0 0 -3
0 0 0 1 0 0 0 3/2
0 0 0 0 0 -1 0 -1
[./data/lshape1_dim3.off]: NON empty kernel.
0 -1 0 0 0 0 0 -3
0 0 0 0 0 -1 0 -1
0 0 0 -1 0 0 0 -3
0 0 0 0 0 1 0 -1
0 0 0 1 0 0 0 3/2
0 -1 0 0 0 0 0 3/2
0 0 0 -1 0 0 0 3/2
0 -1 0 0 0 0 0 -3
0 0 0 1 0 0 0 -3
0 1 0 0 0 0 0 -3
[./data/ushape1_dim3.off]: empty kernel.
0 1 0 0 0 0 0 3
0 0 0 0 0 1 0 1
0 0 0 1 0 0 0 3
terminate called after throwing an instance of 'CGAL::Assertion_exception'
what(): CGAL ERROR: assertion violation!
Expr: normalized(cet->circle()) == normalized(ce->circle().opposite())
File: /home/gdamiand/sources/cgal/Nef_3/include/CGAL/Nef_3/SNC_external_structure.h
Line: 620
Abandon (core dumped)

[afabri]

Did you get that in the code I have put in the pull request? What you have put in surface_mesh_kernel.txt does not even compile, as you probably extracted it from some application.

[afabri]

Just saw "./issue8644" , so it is in my branch. I do not have the assertion. What is your test platform? Let me flag it ready for testing so that we see it in the testsuite.

[afabri]

Hello @gdamiand
So it fails on some platforms in testsuite 6.1-Ic-38