Possible wrong post state root on ZeroCallTests

[leonardostsouza]

Some of the tests seem to be considering empty accounts to calculate the post state root. From what I understand about the protocol, the empty accounts should be treated similar to non-existing accounts, so this would be incorrect behavior. Is there any exception to this rule I am not aware of?

A quick example to illustrate what I am talking about:

==> LegacyTests/Constantinople/GeneralStateTests/stZeroCallsTest/ZeroValue_CALLCODE_ToEmpty (Byzantium):
Final State:
================
::: Account 0x2adc25665018aa1fe0e6bc666dac8fc2697ff9ba
:::     nonce   :  0x0
:::     balance :  0x13f46
:::     code    :  0x
:::     storage : {}

::: Account 0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b
:::     nonce   :  0x1
:::     balance :  0xe8d4a3d0ba
:::     code    :  0x
:::     storage : {}

::: Account 0xb94f5374fce5edbc8e2a8697c15331677e6ebf0b
:::     nonce   :  0x0
:::     balance :  0x0
:::     code    :  0x5a6000556000600060006000600073c94f5374fce5edbc8e2a8697c15331677e6ebf0b61ea60f26001555a606455
:::     storage : {'0x00': '0x08d5b6', '0x01': '0x01', '0x64': '0x08369d'}

::: Account 0xc94f5374fce5edbc8e2a8697c15331677e6ebf0b
:::     nonce   :  0x0
:::     balance :  0x0
:::     code    :  0x
:::     storage : {}

Correct final state root according to the test file (includes the empty account 0xc94f5374fce5edbc8e2a8697c15331677e6ebf0b): 0x1c57ca04dea8d4f09c81c54593838c45cf059d13dcfb9f9d70dca2bc1ad285e9

State root I would expect (not considering account 0xc94f5374fce5edbc8e2a8697c15331677e6ebf0b): 0x1531bd9ebfed425c01ab97871c2f5415683b614160c0de07e95ca46a3f8222e3

I could observe similar behavior in the following tests for all forks:

• LegacyTests/Constantinople/GeneralStateTests/stZeroCallsTest/ZeroValue_CALLCODE_ToEmpty
• LegacyTests/Constantinople/GeneralStateTests/stZeroCallsTest/ZeroValue_CALLCODE_ToOneStorageKey
• LegacyTests/Constantinople/GeneralStateTests/stZeroCallsTest/ZeroValue_DELEGATECALL_ToEmpty
• LegacyTests/Constantinople/GeneralStateTests/stZeroCallsTest/ZeroValue_DELEGATECALL_ToOneStorageKey

I didn't check how the non-legacy tests are behaving.
Are the tests really expecting the correct state root?

[winsvega]

The empty account present in a state for the root hash by default. Unless after eip158, if it was touched during the call, it is removed from state.

ethereum/EIPs#158

[leonardostsouza]

I see. Thanks for the clarification. It was very helpful