Validators should stop submitting BLS-sigs when they are syncing

[gitferry]

When a validator is syncing, it will relay all the history transactions including the ones sending BLS-sig transactions that have been sent already. It will cause unnecessary gas costs and unpredictable errors. So we should disable BLS submission when the validator is syncing.

[gitferry]

After some investigation, it seems that in the application layer (cosmos-sdk), we don't know whether the node (Tendermint) is syncing. This issue will be naturally solved after ABCI++ is upgraded as BLS signatures will be no longer in blocks as transactions. Should we close this issue now? cc @vitsalis

[vitsalis]

Yep, agreed. When do we expect ABCI++ to become available?

[gitferry]

It's a good question but tbh I'm not sure about that, especially given the recent drama that happened to Tendermint. But I found this. It seems that ABCI 2.0 (ABCI++) would be in version 0.38.x