Change the fallback priority mechanism to be based on gas price (#1289)

* Change the fallback priority mechanism to be based on gas price

* Update CHANGELOG.md

Co-authored-by: Federico Kunze Küllmer <31522760+fedekunze@users.noreply.github.com>
Co-authored-by: Freddy Caceres <facs95@gmail.com>

CHANGELOG.md

@@ -59,6 +59,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (feemarket) [\#1165](https://github.com/evmos/ethermint/pull/1165) Add hint in specs about different gas terminology for gas in Cosmos and Ethereum.
 * (cli) [#1226](https://github.com/evmos/ethermint/pull/1226) Add custom app db backend flag.
 * (cli) [#1230](https://github.com/evmos/ethermint/pull/1230) Remove redundant positional height parameter from feemarket's query cli.
+* (ante) [#1289](https://github.com/evmos/ethermint/pull/1289) Change the fallback tx priority mechanism to be based on gas price.
 * (test) [#1311](https://github.com/evmos/ethermint/pull/1311) add integration test for the rollback cmd
 
 ### Bug Fixes

app/ante/fee_checker.go

@@ -116,17 +116,18 @@ func checkTxFeeWithValidatorMinGasPrices(ctx sdk.Context, tx sdk.FeeTx) (sdk.Coi
 		}
 	}
 
-	priority := getTxPriority(feeCoins)
+	priority := getTxPriority(feeCoins, int64(gas))
 	return feeCoins, priority, nil
 }
 
-// getTxPriority returns a naive tx priority based on the amount of the smallest denomination of the fee
+// getTxPriority returns a naive tx priority based on the amount of the smallest denomination of the gas price
 // provided in a transaction.
-func getTxPriority(fees sdk.Coins) int64 {
+func getTxPriority(fees sdk.Coins, gas int64) int64 {
 	var priority int64
 
 	for _, fee := range fees {
-		amt := fee.Amount.Quo(types.DefaultPriorityReduction)
+		gasPrice := fee.Amount.QuoRaw(gas)
+		amt := gasPrice.Quo(types.DefaultPriorityReduction)
 		p := int64(math.MaxInt64)
 
 		if amt.IsInt64() {