Gossipsub: unable to re-publish message after failed attempts.

[xu-cheng]

Sometimes, publishing message may fail in Gossipsub due to PublishError::InsufficientPeers. In this case, the application may want to retry the publish later. However, the subsequent re-publish would fail due to PublishError::Duplicate when a content-based hash is used to compute message id.

I think if a message fails to be published, it should be removed from duplicate_cache also maybe mcache.

[mxinden]

@AgeManning @blacktemplar would you mind taking a look?

[AgeManning]

Thanks for raising this edge case.

This is an issue with content-addressed messages. I've updated the gossipsub protocol in #1930 to only add messages to the caches if they have been sent to at least one peer.

[romanb]

Closed by #1930.