ERC20 Approval event conformance

[k06a]

ERC20 Token Standard tells:

Approval
MUST trigger on any successful call to approve(address _spender, uint256 _value).

But current ERC20 implementation emits Approval event on every allowance change. Is there any practical reason for this or just a bug?

Original discussion started here: makerdao/dss#76

[nventuro]

This has been discussed extensively in the past, and was a concious design decision. You can read more about the motivation on this issue (and associated PR): #707. The short version is that not emitting those events makes it impossible to reconstruct the state from events only.

Is this causing any issues in your application?

[k06a]

@nventuro that makes sense 👌