sign returns 1 for NAN

[lilizoey]

Godot version

4.1.rc3

System information

Linux 5.10.181-2-MANJARO

Issue description

sign(NAN) and signf(NAN) both return 1. But this doesn't seem right, as NAN > 0 is false (as all other NAN comparison are). These should really return NAN not 1.

Steps to reproduce

run

print(sign(NAN), " ", signf(NAN))

output is:
1 1

Minimal reproduction project

N/A

[dalexeev]

godot/core/typedefs.h

Lines 110 to 113 in cdd2313

	template <typename T>
	constexpr const T SIGN(const T m_v) {
	return m_v == 0 ? 0.0f : (m_v < 0 ? -1.0f : +1.0f);
	}

godot/core/variant/variant_utility.cpp

Lines 243 to 275 in cdd2313

	static inline Variant sign(const Variant &x, Callable::CallError &r_error) {
	r_error.error = Callable::CallError::CALL_OK;
	switch (x.get_type()) {
	case Variant::INT: {
	return SIGN(VariantInternalAccessor<int64_t>::get(&x));
	} break;
	case Variant::FLOAT: {
	return SIGN(VariantInternalAccessor<double>::get(&x));
	} break;
	case Variant::VECTOR2: {
	return VariantInternalAccessor<Vector2>::get(&x).sign();
	} break;
	case Variant::VECTOR2I: {
	return VariantInternalAccessor<Vector2i>::get(&x).sign();
	} break;
	case Variant::VECTOR3: {
	return VariantInternalAccessor<Vector3>::get(&x).sign();
	} break;
	case Variant::VECTOR3I: {
	return VariantInternalAccessor<Vector3i>::get(&x).sign();
	} break;
	case Variant::VECTOR4: {
	return VariantInternalAccessor<Vector4>::get(&x).sign();
	} break;
	case Variant::VECTOR4I: {
	return VariantInternalAccessor<Vector4i>::get(&x).sign();
	} break;
	default: {
	r_error.error = Callable::CallError::CALL_ERROR_INVALID_METHOD;
	return Variant();
	}
	}
	}

godot/core/variant/variant_utility.cpp

Lines 277 to 283 in cdd2313

	static inline double signf(double x) {
	return SIGN(x);
	}
	static inline int64_t signi(int64_t x) {
	return SIGN(x);
	}

I'm not sure what behavior should be, it's probably implemented this way for performance. But perhaps we could add checks to the @GlobalScope utility functions without touching the core SIGN() function?

For comparison, in JavaScript:

Math.sign(NaN) // NaN