Evermint is fork of Evmos v12.1.6 for research & development purpose

Update Sep 2024: implemented in Evermint by #129

Currently, Evermint is using EthAccount as the default proto account and the only type of account supported.
That causes some limit:

• Use Cosmos-SDK x/vesting module
• Limit potential of integrate new features from CosmosSDK
• Wasting storage to store evmtypes.EmptyCodeHash 32 bytes value that also exists in every non-contract EthAccount (see prove).

Request:

• Remove EthAccount
• Make authtypes.BaseAccount as default proto account, compatible with EVM module.
• All current testcases must be kept to make sure the implementation is fully compatible.
• x/evm non-genesis account now only support export/import only accounts with either code or storage
• Optimize store by only store code hash which len(code_hash) > 0 && code_hash <> evmtypes.EmptyCodeHash instead of saving it into every EthAccount record. This change will slightly lower gas fee required to read from store in non-evm Txs

Aware:

• x/auth keeper RemoveAccount
• Account bytes compatible: currently Cosmos supports 20 & 32 bytes address (ICA)

Mindset changes:

• Contract account is now accounts that has CodeHash record (len(code_hash) == 0 || code_hash == evmtypes.EmptyCodeHash will be removed from store)
• ETH-compatible account is now accounts those are not contract accounts, plus len(address_bytes) == 20. If it is in blockedAddrs by x/bank, will be an error in stateDb.Commit() phrase.
• When doing account migration, remember to consider migrate code hash, if needed.

Migration aware (if any chain planned to implement this):

• Must define migration to be able to upgrade Ethermint/Evmos chains.
• Must test query historical data and data must be matched pre and after upgrade.