fix: panic in SendCheckpointToBTC

[guoshijiang]

resolve this issue: #137

[SebastianElvis]

Lgtm, thanks for the fix!

Probably @gitferry can take a look as well

[gitferry]

Thanks for the report! I think the issue is valid. Basically, in the case of #137

1. the submitter failed to submit the first tx of a checkpoint
2. it fell into MaybeResubmitSecondCheckpointTx to try to re-submit the second tx of the lastSubmittedCheckpoint. Then the panic happened because the submitter was initiated with empty lastSubmittedCheckpoint
   • the check if durSeconds < rl.config.ResendIntervalSeconds can pass is because the submiter was initiated with empty lastSubmittedCheckpoint

Therefore, I think a proper fix is to continue the for loop if SendCheckpointToBTC returns error. This ensures that an empty lastSubmittedCheckpoint will not go to MaybeResubmitSecondCheckpointTx.

@Lazar955 wdyt?

[Lazar955]

Thanks for the report! I think the issue is valid. Basically, in the case of #137

1. the submitter failed to submit the first tx of a checkpoint

2. it fell into MaybeResubmitSecondCheckpointTx to try to re-submit the second tx of the lastSubmittedCheckpoint. Then the panic happened because the submitter was initiated with empty lastSubmittedCheckpoint

   • the check if durSeconds < rl.config.ResendIntervalSeconds can pass is because the submiter was initiated with empty lastSubmittedCheckpoint

Therefore, I think a proper fix is to continue the for loop if SendCheckpointToBTC returns error. This ensures that an empty lastSubmittedCheckpoint will not go to MaybeResubmitSecondCheckpointTx.

@Lazar955 wdyt?

Agreed with @gitferry, err happened in SendCheckpointToBTC therefore we shouldn't execute MaybeResubmitSecondCheckpointTx but rather continue.

@guoshijiang can you amend your PR?

[guoshijiang]

Thanks for the report! I think the issue is valid. Basically, in the case of #137

1. the submitter failed to submit the first tx of a checkpoint

2. it fell into MaybeResubmitSecondCheckpointTx to try to re-submit the second tx of the lastSubmittedCheckpoint. Then the panic happened because the submitter was initiated with empty lastSubmittedCheckpoint

   • the check if durSeconds < rl.config.ResendIntervalSeconds can pass is because the submiter was initiated with empty lastSubmittedCheckpoint

Therefore, I think a proper fix is to continue the for loop if SendCheckpointToBTC returns error. This ensures that an empty lastSubmittedCheckpoint will not go to MaybeResubmitSecondCheckpointTx.
@Lazar955 wdyt?

Agreed with @gitferry, err happened in SendCheckpointToBTC therefore we shouldn't execute MaybeResubmitSecondCheckpointTx but rather continue.

@guoshijiang can you amend your PR?

update

[Lazar955]

Thanks for the report! I think the issue is valid. Basically, in the case of #137

1. the submitter failed to submit the first tx of a checkpoint

2. it fell into MaybeResubmitSecondCheckpointTx to try to re-submit the second tx of the lastSubmittedCheckpoint. Then the panic happened because the submitter was initiated with empty lastSubmittedCheckpoint

   • the check if durSeconds < rl.config.ResendIntervalSeconds can pass is because the submiter was initiated with empty lastSubmittedCheckpoint

Therefore, I think a proper fix is to continue the for loop if SendCheckpointToBTC returns error. This ensures that an empty lastSubmittedCheckpoint will not go to MaybeResubmitSecondCheckpointTx.
@Lazar955 wdyt?

Agreed with @gitferry, err happened in SendCheckpointToBTC therefore we shouldn't execute MaybeResubmitSecondCheckpointTx but rather continue.
@guoshijiang can you amend your PR?

update

Will approve once CI passes. Update the changelog file as well (see the previous updates)

[Lazar955]

lgtm, thanks for your contribution