DuplicateTopics error when emitting event with equal values in topics

[usetech-llc]

FAQ

• Are you using the nightly Rust channel to compile your smart contract?
  Yes, nightly-2021-01-15

• Are you using an up-to-date cargo-contract? Check via cargo contract --version.

  • If you are unsure please tell us your version noted there.
    cargo contract 0.8.0

• Are you using an up-to-date ink! version in your smart contract?

  • You can check this by looking into the [dependencies] section of your Cargo.toml.
  • If you are unsure please tell us your version noted there.

v3.0.0-rc2

Describe the bug
When I post this event:

            Self::env().emit_event(WithdrawNFT {
                address: user,
                collection_id,
                token_id,
            });

with collection_id = 1 and token_id = 1, I get DuplicateTopics error. But when I change token ID to 2, I don't get it, transaction runs OK.

[cmichi]

@usetech-llc Thanks for the bug report! I'm having a hard time replicating it though. I used this contract as a minimal example and can't provoke the error. I'm using the flipper/Cargo.toml, the canvas-node as the Substrate instance, and the Canvas UI for deployment.

Some more questions: What version of Substrate are you using? What are the data types of collection_id and token_id?

Also we just released a new cargo-contract version 0.9.1 which you can install with cargo install --force cargo-contract. This shouldn't have an impact on the events logic, but maybe also worth a try.

[athei]

Isn't that #594? Those changes are in master but unreleased.

[usetech-llc]

We are using older (January ~8) version of Contracts pallet, but updating it at the moment. When we are done with update, I'll test it again and let you know, thanks!

[athei]

The problem isn't the old version of the pallet. The bug was in ink!. If you are using v3.0.0-rc2 the fix is not in.

[usetech-llc]

I see, thanks! Do you have any plans to release rc3 or the final release 3.0?

[cmichi]

@usetech-llc Yes, we want to do a rc3 asap. At the moment we are just waiting for a bug in our bitvec dependency to be fixed. This requires a nasty hotfix in every Cargo.toml and we don't want to require users to apply that hotfix in order for our rc3 to work.

@athei Good catch!