Require binary variables in logical constraints

[Joao-Dionisio]

Fix #1004

[Copilot]

Pull Request Overview

This PR addresses issue #1004 by enforcing that logical constraints only accept binary variables.

• Added a failing test for non-variable inputs to logical constraints
• Inserted runtime type checks in Cython methods handling logical constraints
• Documented the fix in the changelog

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
tests/test_cons.py	Added test_cons_logical_fail marked xfail to catch non-Variable inputs in OR cons
src/pyscipopt/scip.pxi	Added isinstance checks for vars in logical-constraint methods; tweaked branchVarVal signature
CHANGELOG.md	Logged the segmentation-fault fix when expressions were used in logical constraints

Comments suppressed due to low confidence (2)

tests/test_cons.py:90

• Instead of xfail, use with pytest.raises(TypeError) to explicitly assert the exception; this ensures the test only passes when the correct error is raised.

m.addConsOr([x1*x3, x2*x4], result1)

src/pyscipopt/scip.pxi:8775

• [nitpick] The signature indentation and mixed annotation style differ from surrounding methods. Align the indentation and consider adding a type for value or reverting to the original untyped signature for consistency.

def branchVarVal(self, Variable variable, value):

[DominikKamp]

The suppressed suggestions seem to make more sense than the unsuppressed suggestions.

[DominikKamp]

Could you explain when test functions also need to be called?

[Joao-Dionisio]

Could you explain when test functions also need to be called?

Ah, I didn't understand what you were saying at first, but if you're talking about the test_benders, then I shouldn't have pushed. I just use it to make it easier for me to debug something with VSCode. (Here I deleted more mallocs than I should've, causing a segfault)

So the answer is never, actually :)

[DominikKamp]

There are also other test files where this landed in the source, could you check?

[Joao-Dionisio]

Yeah, had one in the numerical tests, thank you! Okay, so everything is done now, right?

[DominikKamp]

Well, now that the logic seems fixed, the code review can begin...

[Joao-Dionisio]

You know, Dominik, I have a draft for a song titled "Every Commit you Make (Every Breath You Take - Dominik Edition)". It's times like these that I think I should pick up my guitar again 😆

[DominikKamp]

After resolving the remaining threads, this is fine.

[Joao-Dionisio]

That should be it, then. Thank you for the awesome review, Dominik!