This code determines the order in which the next branch element and the
current value should be hashed to produce the parent node in the Merkle tree.
The existing code fails to verify branches constructed in the standard way.
This patch fixes the spec code so that it works properly by using an appropriate
parity calculation.
Example code here to illustrate it working:
https://gist.github.com/ralexstokes/9d82e188bd3286ff74a1fa1dcb5068e0
`EJECTION_BALANCE` is in units of ETH.
`state.validator_balances[index]` is in units of Gwei.
For the ejection computation to work as desired, we need to convert the
`EJECTION_BALANCE` constant from ETH to Gwei.
There should be a correspondence here but referring to the slot is more
explicit, especially for those who are not as familiar with the
details of FFG finalization.
* Make RANDAO into a hash chain (this makes it easy for applications to prove the intermediate RANDAO reveals).
* Include `state.slot` when shuffle to avoid stale shuffles with skip slots
* Cleanup comments related to custody
* Rename "Miscellaneous" to "Custody" in the table of contents
* Use `INITIAL_SLOT_NUMBER` instead of `0` for initial custody slots
* (typo) Fix `second_latest_custody_reseed_slot` => `penultimate_custody_reseed_slot`
* `processed_deposit_root` => `latest_deposit_root`
* `receipt_root` => `deposit_root`
* `receipt_tree` => `deposit_tree`
* Emphasize that deposits are Ethereum 1.0 deposits in text in various places
* `Eth1Deposit` => `Deposit` for consistency (Also happy sticking with `Eth1Deposit` and replacing `deposit_` with `eth1_deposit_` everywhere. This may be unnecessary since Ethereum 2.0 deposits can be distinguished with the `shard_` prefix, e.g. `ShardDeposit` and `shard_deposit`.)
* Clarify `withdrawal_credentials`.
* Clarify that multiple Ethereum 1.0 blocks can have the same deposit root.
Cleanups
* (typo) Remove `get_new_validator_registry_delta_chain_tip` from table of contents
* (typo) Update "Routines for updating validator status" in table of contents
* Update `FAR_FUTURE_SLOT` from `2**63` to `2**64 - 1`
* Put more constants in "Initial values", homogenise
* Cleanup note formatting
* Remove `ZERO_BALANCE_VALIDATOR_TTL` logic (to be possibly reintroduced in phase 2).
* Cleanup `min_empty_validator_index`
* Rename `deposit` to `amount` in `process_deposit` and `DepositData`.
* (typo) Remove new line under `process_penalties_and_exits`
* (typo) "Status codes" => "Status flags" in the table of contents
* (typo) `(state.slot - EPOCH_LENGTH) % LATEST_RANDAO_MIXES_LENGTH` => Use `SEED_LOOKAHEAD` instead.
* Put `state.validator_registry_latest_change_slot = state.slot` in `update_validator_registry`.
* Use `GENESIS_SLOT` for `last_poc_change_slot=0` and `second_last_poc_change_slot=0`.
Bugfixes
* (typo) `validator_exit` => `exit.validator_index`
* Separate initial deposits and initial activations to avoid double activations
* Replace `proposer.status != EXITED_WITH_PENALTY` with `validator.penalized_slot > state.slot` in two different places.
* Replace `status == EXITED_WITH_PENALTY` with `validator.penalized_slot <= state.slot` (and validator active) in two different places.
* Added `activation_slot`, `exit_slot`, `penalized_slot`, `withdrawal_slot`, use these to determine if a validator is active
* Universal min activation/exit delay of 256 slots
* Min exit time of ~1 day, but penalization delays this to ~18 days
* Penalty calculation period of `[time penalized - 18 days, time penalized + 18 days]`; made the total penalties array fixed size and wraparound to make calculation more fine-grained
* Processes withdrawals in all epochs, not just dynasty-changing epochs
* Change `get_shuffling` function to take slot as argument
Not yet done:
* Removed `shard_committees` from the state
* Removed persistent committees from the state