Parity-ethereum: Parity doesn't return `removed` flag on filter changes

[LogvinovLeon]

I'm running:

• Parity version: 1.8.1
• Operating system: Linux
• And installed: docker images

---

I've installed a log filter and try to get filter changes.
Standard defines, that every emited log shouls have a removed field, but the logs I'm getting miss this field.

        {
            "address": "0x71d271f8b14adef568f8f28f1587ce7271ac4ca5",
            "blockHash": "0xe8ed671b455103a24c9c0efc1204416687a2ba2af00c397c350c011202f4d75b",
            "blockNumber": "0x43772e",
            "data": "0x000000000000000000000000db790e1d4a5d7f71db60e55aa7b3af7cf9bbabf60000000000000000000000002013201070451a038d99cbbecedb879b7bdb73e8",
            "logIndex": "0x20",
            "topics": [
                "0x09e48df7857bd0c1e0d31bb8a85d42cf1874817895f171c917f6ee2cea73ec20"
            ],
            "transactionHash": "0x3ab0317c18848368581da767ce0518cac675630f722d1ef8dc385762d5c07c67",
            "transactionIndex": "0x35",
            "transactionLogIndex": "0x0",
            "type": "mined"
        }

[debris]

it's NOT a bug.

it's caused by insidious change in the specification on 18 Jul 2016 followed by the commit in go-ethereum in Dec 2016.

[tomusdrw]

it's NOT a bug

That said, we are aiming for compatibility between clients, so it is important to implement that soonish.

@debris I don't agree that it's insubstantial, since we currently don't inform about removed log events at all - it requires quite significant change in filters logic to support that.

[5chdn]

Note, A-labels are for pull-requests and Q-labels for issues.

[sorpaas]

~Duplicate of #7994~

(Edit: looks like not the same issue.)

[sorpaas]

@folsen @debris @tomusdrw

Right now we have type field in log, which will be set to "removed" if a log is removed in reorg. This is equivalent to, as in this issue, having a removed field set to true. If the goal for resolving the issue is to keep compatibility, then maybe we can support both type and removed?

[folsen]

@sorpaas makes sense to me

[tomusdrw]

@sorpaas yup, although I believe that filters never report removed log entries at all, so the fix is only for pubsub implementation. So #8796 doesn't fully address this issue I believe.

[sorpaas]

@tomusdrw I think that one is fixed in https://github.com/paritytech/parity/pull/8463. So on the filter level removed logs should be returned as normal on master. :)

[tomusdrw]

I think #8463 fixes the re-org messages, but only for pubsub. The regular RPC filters never had anything like that implemented (not even sure if it was ever speced), have a look here: https://github.com/paritytech/parity/blob/master/rpc/src/v1/impls/eth_filter.rs#L168-L206