Clear expiration flag after user operation removed?

[wanliqun]

After we removed the expired user operation, we might need to clear the expiration datetime for it like delete(e.seenAt, userOpHash). This is because if the bundle transaction is successfully mined to block but reverted due to some reason, user tends to send the user operation again to the mempool, and will never be included to next bundle transaction due to expiration drop.

// DropExpired returns a BatchHandlerFunc that will drop UserOperations from the mempool if it has been around
// for longer than the TTL duration.
func (e *ExpireHandler) DropExpired() modules.BatchHandlerFunc {
	return func(ctx *modules.BatchHandlerCtx) error {
		end := len(ctx.Batch) - 1
		for i := end; i >= 0; i-- {
			hash := ctx.Batch[i].GetUserOpHash(ctx.EntryPoint, ctx.ChainID)
			if seenAt, ok := e.seenAt[hash]; !ok {
				e.seenAt[hash] = time.Now()
			} else if seenAt.Add(e.ttl).Before(time.Now()) {
				ctx.MarkOpIndexForRemoval(i)
			}
		}
		return nil
	}
}

[wanliqun]

I came across this problem due to the gas estimation is not very accurate, so even though my user operation is included to a bundle transaction and then mined and broadcasted to the blockchain, the transaction just reverted. Then when I tried to resend my userop, it was never gonna be included into a new bundle transaction due to expiration drop.

[hazim-j]

Can you tell me more about your gas estimation issue? Do you have a transaction hash of the reverted UserOperation?

[wanliqun]

I'm still investigating on this. It's actually on a EVM compatible chain, which doesn't provide debug_traceCall yet. I will keep you updated what you may concern.