Fixes #1884 -- don't leave an error on the stack in public_eq

    where

        U: HasPublic,

    {

        unsafe { ffi::EVP_PKEY_cmp(self.as_ptr(), other.as_ptr()) == 1 }

        let res = unsafe { ffi::EVP_PKEY_cmp(self.as_ptr(), other.as_ptr()) == 1 };

        // Clear the stack. OpenSSL will put an error on the stack when the

        // keys are different types in some situations.

        let _ = ErrorStack::get();

        res

    }

    /// Raw byte representation of a public key.

    use crate::dh::Dh;

    use crate::dsa::Dsa;

    use crate::ec::EcKey;

    use crate::error::Error;

    use crate::nid::Nid;

    use crate::rsa::Rsa;

    use crate::symm::Cipher;

        let key = PKey::ec_gen("prime256v1").unwrap();

        assert!(key.ec_key().is_ok());

    }

    #[test]

    fn test_public_eq() {

        let rsa = Rsa::generate(2048).unwrap();

        let pkey1 = PKey::from_rsa(rsa).unwrap();

        let group = crate::ec::EcGroup::from_curve_name(Nid::X9_62_PRIME256V1).unwrap();

        let ec_key = EcKey::generate(&group).unwrap();

        let pkey2 = PKey::from_ec_key(ec_key).unwrap();

        assert!(!pkey1.public_eq(&pkey2));

        assert!(Error::get().is_none());

    }

}