refactor: move consumeMinGas() call inside refundGas()

Author: ARR4N

core/state_transition.go

@@ -446,7 +446,6 @@ func (st *StateTransition) TransitionDb() (*ExecutionResult, error) {
 		// After EIP-3529: refunds are capped to gasUsed / 5
 		gasRefund = st.refundGas(params.RefundQuotientEIP3529)
 	}
-	st.consumeMinimumGas() // libevm: see comment on method re call-site requirements
 	effectiveTip := msg.GasPrice
 	if rules.IsLondon {
 		effectiveTip = cmath.BigMin(msg.GasTipCap, new(big.Int).Sub(msg.GasFeeCap, st.evm.Context.BaseFee))
@@ -479,6 +478,8 @@ func (st *StateTransition) refundGas(refundQuotient uint64) uint64 {
 	}
 	st.gasRemaining += refund
 
+	st.consumeMinimumGas() // libevm: see comment on method re call-site requirements
+
 	// Return ETH for remaining gas, exchanged at the original rate.
 	remaining := uint256.NewInt(st.gasRemaining)
 	remaining = remaining.Mul(remaining, uint256.MustFromBig(st.msg.GasPrice))

core/state_transition.libevm.go

@@ -17,10 +17,6 @@
 package core
 
 import (
-	"math/big"
-
-	"github.com/holiman/uint256"
-
 	"github.com/ava-labs/libevm/log"
 	"github.com/ava-labs/libevm/params"
 )
@@ -50,39 +46,16 @@ func (st *StateTransition) canExecuteTransaction() error {
 
 // consumeMinimumGas updates the gas remaining to reflect the value returned by
 // [params.RulesHooks.MinimumGasConsumption]. It MUST be called after all code
-// that modifies gas consumption; i.e. `st.gasRemaining` MUST remain constant
-// after consumeMinimumGas returns.
+// that modifies gas consumption but before the balance is returned for
+// remaining gas.
 func (st *StateTransition) consumeMinimumGas() {
 	limit := st.msg.GasLimit
-	minConsume := st.rulesHooks().MinimumGasConsumption(st.msg.GasLimit)
-	minConsume = min(minConsume, limit) // as documented in [params.RulesHooks]
-
-	maxRemaining := limit - minConsume
-	if st.gasRemaining < maxRemaining {
-		return
-	}
-
-	diff := st.gasRemaining - maxRemaining
-	st.gasRemaining -= diff
-	if err := st.gp.SubGas(diff); err != nil {
-		// This would mean that the transaction wouldn't have been able to spend
-		// up to its limit.
-		log.Crit(
-			"Broken gas-charging invariant",
-			"tx limit", limit,
-			"min consume", minConsume,
-			"extra consume", diff,
-			"SubGas() error", err,
-		)
-	}
-
-	spend := new(big.Int).Mul(st.msg.GasPrice, new(big.Int).SetUint64(diff))
-	st.state.SubBalance(st.msg.From, uint256.MustFromBig(spend))
-
-	log.Debug(
-		"Consumed extra gas to enforce minimum",
-		"tx_limit", limit,
-		"min_consumption", minConsume,
-		"extra_consumption", diff,
+	minConsume := min(
+		limit, // as documented in [params.RulesHooks]
+		st.rulesHooks().MinimumGasConsumption(limit),
+	)
+	st.gasRemaining = min(
+		st.gasRemaining,
+		limit-minConsume,
 	)
 }