ante: update nonce check (#550)

CHANGELOG.md

@@ -35,6 +35,12 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 # Changelog
 
+## Unreleased
+
+### Bug fixes
+
+* (app/ante) [\#550](https://github.com/ChainSafe/ethermint/pull/550) Update ante handler nonce verification to accept any nonce greater than or equal to the expected nonce to allow to successive transactions. 
+
 ## [v0.2.0] - 2020-09-24
 
 ### State Machine Breaking

app/ante/eth.go

@@ -253,7 +253,10 @@ func (nvd NonceVerificationDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, sim
 	}
 
 	seq := acc.GetSequence()
-	if msgEthTx.Data.AccountNonce != seq {
+	// if multiple transactions are submitted in succession with increasing nonces,
+	// all will be rejected except the first, since the first needs to be included in a block
+	// before the sequence increments
+	if msgEthTx.Data.AccountNonce < seq {
 		return ctx, sdkerrors.Wrapf(
 			sdkerrors.ErrInvalidSequence,
 			"invalid nonce; got %d, expected %d", msgEthTx.Data.AccountNonce, seq,