eth/gasprice: fix fee history percentile weighting under eip-8037

Weight reward percentiles by cumulative receipt gas instead of block
header gas used, which reflects max(regular, state) and can exceed the
sum of per-tx receipt gas.

eth/gasprice/feehistory.go

@@ -140,17 +140,29 @@ func (oracle *Oracle) processBlock(bf *blockFees, percentiles []float64) {
 		return a.reward.Cmp(b.reward)
 	})
 
+	// Percentile rewards are weighted by per-tx receipt gas. Under EIP-8037
+	// block gas used is max(cumulative regular, cumulative state) and can exceed
+	// the sum of receipt gas, so base thresholds on the receipt total.
+	totalGasUsed := bf.receipts[len(bf.receipts)-1].CumulativeGasUsed
+	bf.results.reward = percentileRewards(sorter, totalGasUsed, percentiles)
+}
+
+// percentileRewards returns the effective priority-fee reward at each requested
+// percentile, with transactions sorted by ascending tip and weighted by gas used.
+func percentileRewards(sorter []txGasAndReward, totalGasUsed uint64, percentiles []float64) []*big.Int {
+	reward := make([]*big.Int, len(percentiles))
 	var txIndex int
 	sumGasUsed := sorter[0].gasUsed
 
 	for i, p := range percentiles {
-		thresholdGasUsed := uint64(float64(bf.block.GasUsed()) * p / 100)
-		for sumGasUsed < thresholdGasUsed && txIndex < len(bf.block.Transactions())-1 {
+		thresholdGasUsed := uint64(float64(totalGasUsed) * p / 100)
+		for sumGasUsed < thresholdGasUsed && txIndex < len(sorter)-1 {
 			txIndex++
 			sumGasUsed += sorter[txIndex].gasUsed
 		}
-		bf.results.reward[i] = sorter[txIndex].reward
+		reward[i] = sorter[txIndex].reward
 	}
+	return reward
 }
 
 // resolveBlockRange resolves the specified block range to absolute block numbers while also

eth/gasprice/feehistory_test.go

@@ -22,9 +22,42 @@ import (
 	"math/big"
 	"testing"
 
+	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rpc"
 )
 
+// TestPercentileRewardsReceiptGasEIP8037 checks that reward percentiles are
+// weighted by the sum of per-tx receipt gas, not the block header gas used.
+// Under EIP-8037 the header reflects max(cumulative regular, cumulative state)
+// and can exceed receipt totals; using it as the threshold skews percentiles.
+func TestPercentileRewardsReceiptGasEIP8037(t *testing.T) {
+	lowTip := big.NewInt(1)
+	highTip := big.NewInt(100 * params.GWei)
+
+	const (
+		lowGas        = 100_000
+		highGas       = 21_000
+		receiptTotal  = lowGas + highGas
+		headerGasUsed = 500_000 // state bottleneck, well above receiptTotal
+	)
+	sorter := []txGasAndReward{
+		{gasUsed: lowGas, reward: lowTip},
+		{gasUsed: highGas, reward: highTip},
+	}
+
+	got := percentileRewards(sorter, receiptTotal, []float64{50})
+	if got[0].Cmp(lowTip) != 0 {
+		t.Fatalf("50th percentile reward = %s, want low-tip %s (receipt gas %d)",
+			got[0], lowTip, receiptTotal)
+	}
+
+	// Using block header gas used as the weight base selects the wrong tx.
+	gotBroken := percentileRewards(sorter, headerGasUsed, []float64{50})
+	if gotBroken[0].Cmp(highTip) != 0 {
+		t.Fatalf("sanity check: header-based weighting = %s, want high-tip %s", gotBroken[0], highTip)
+	}
+}
+
 func TestFeeHistory(t *testing.T) {
 	var cases = []struct {
 		pending             bool