1.7.1: `Point.add` is not throwing for "1 + -1 == 0/Infinity" about noble-secp256k1

[paulmillr]

I believe the behavior in 1.7.0 is the correct one.

Why?

[paulmillr]

I suggest to update your definition of tweak / publicAdd functions. They need to do the validation. P - P is valid point 0. It may not be valid in your context, but that's not applicable to everyone.

[landabaso]

I suggest to update your definition of tweak / publicAdd functions. They need to do the validation. P - P is valid point 0. It may not be valid in your context, but that's not applicable to everyone.

Thanks. I catch this case on my side now.

Why

Previous behavior up to version 1.7.0 did not return a point, which matched the behavior in tiny-secp256k1.
I simply assumed that this was the typical output for secp256k1 libraries and that this minor breaking change had not been intentional.