Fix for hard crash if guiceCurves node is present but empty in wing segment

[joergbrech]

Fixes #962

Description

This PR adds an internal check if an std::vector is empty before trying to access elements. As a consequence, the wing loft and segment loft will be build just as if there were no guide curves defined.

Note that CPACS 3.3 requires the guideCurves node to be nonempty. We are less restrictive here.

How Has This Been Tested?

A new test has been added

Screenshots, that help to understand the changes(if applicable):

Not applicable

Checklist:

• A test for the new functionality was added.
• All tests run without failure.
• The new code complies with the TiGL style guide.
• [ ] New classes have been added to the Python interface. Not applicable
• [ ] API changes were documented properly in tigl.h. Not applicable

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (7671d7e) 68.90% compared to head (5c645fc) 68.91%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #984   +/-   ##
=======================================
  Coverage   68.90%   68.91%           
=======================================
  Files         298      299    +1     
  Lines       26479    26483    +4     
=======================================
+ Hits        18246    18250    +4     
  Misses       8233     8233           

Files	Coverage Δ
src/guide_curves/CCPACSGuideCurves.cpp	62.96% <100.00%> (+1.42%)	⬆️

... and 1 file with indirect coverage changes

[joergbrech]

@AntonReiswich, I just rebased this on master, so that hopefully the MacOS tests will succeed as well.

[joergbrech]

💩 Some linker error on linux now...I will investigate...

EDIT: This happens on master as well ☹️

[joergbrech]

💩 Some linker error on linux now...I will investigate...

EDIT: This happens on master as well ☹️

I wonder if the PR DLR-SC/tigl-conda#29 is responsible? This is the only change yesterday that I can make out which could potentially influence the build job here.

tigl-conda uses ubuntu-latest, aka Ubuntu 22.04. Maybe the newly built packages introduce a glibc incompatibility?

See also

• https://github.com/actions/runner-images/blob/main/images/ubuntu/Ubuntu2004-Readme.md
• https://github.com/actions/runner-images/blob/main/images/ubuntu/Ubuntu2204-Readme.md

EDIT 2:

Let's see if this helps: DLR-SC/tigl-conda#35

[joergbrech]

Fixed with DLR-SC/tigl-conda#36. This is ready for review again