PR 3007 Fix Seg Fault

[MillaFleurs]

Proposed changes

Fixes a potential seg fault wherein utils.h defaults to a nullptr but utils.cpp doesn't check to see if it's actually passed a nullptr issue #3007 .

Checklist

Put an x in the boxes that apply.

• [ X] I have read the CONTRIBUTING document
• [ X] I have run pre-commit run --all-files to format my code / installed pre-commit prior to committing changes
• [X ] I have added tests that prove my fix is effective or that my feature works
• [ X] I have updated the necessary documentation (if needed)

[zcbenz]

I think we should check null before calling the callback as caller may pass null themselves.

[angeloskath]

Thanks @MillaFleurs for the find and fix and @zcbenz for the fix of fix :-) Let's merge after the tests pass.