v0.10.0 test generators use incorrect domain for deposits

[benjaminion]

Consider test genesis/initialization, although this afflicts other tests as well. This uses minimal config to generate a load of signed deposits.

In minimal config GENESIS_FORK_VERSION is set to 0x00000001. The test generator correctly generates state with this fork information:

fork: {previous_version: '0x00000001', current_version: '0x00000001', epoch: 0}

However, all of the deposits are signed with GENESIS_FORK_VERSION = 0x00000000.

This can be seen by printing some intermediate values in sign_deposit_data():

def sign_deposit_data(spec, deposit_data, privkey):
    deposit_message = spec.DepositMessage(
        pubkey=deposit_data.pubkey,
        withdrawal_credentials=deposit_data.withdrawal_credentials,
        amount=deposit_data.amount)
    domain = spec.compute_domain(spec.DOMAIN_DEPOSIT)
    signing_root = spec.compute_signing_root(deposit_message, domain)
    deposit_data.signature = bls.Sign(privkey, signing_root)
    print("********")
    print(domain.hex())
    print(spec.GENESIS_FORK_VERSION.hex())
    print("********")

This prints

********
0300000000000000
00000001
********

domain ought to be 0x0300000000000001 here. I suspect the default value in compute_domain() is not being correctly handled after the spec constants are overwritten by loading the minimal configuration.

def compute_domain(domain_type: DomainType, fork_version: Version=GENESIS_FORK_VERSION) -> Domain:
    """
    Return the domain for the ``domain_type`` and ``fork_version``.
    """
    return Domain(domain_type + fork_version)

[djrtwo]

Ah, looks like it. Thanks for doing the investigative work.

Will move the setting of fork_version when nothing is passed in into the function

def compute_domain(domain_type: DomainType, fork_version: Version=None) -> Domain:
    """
    Return the domain for the ``domain_type`` and ``fork_version``.
    """
    if fork_version is None:
        fork_version = GENESIS_FORK_VERSION
    return Domain(domain_type + fork_version)