From b6e2b3e8603ce18d5a00ec85765225d094034430 Mon Sep 17 00:00:00 2001
From: Csaba Kiraly <csaba.kiraly@gmail.com>
Date: Mon, 19 Jan 2026 21:57:13 +0100
Subject: [PATCH] core/types: allow fee comparison with large basefee

Signed-off-by: Csaba Kiraly <csaba.kiraly@gmail.com>
---
 core/types/transaction.go | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/core/types/transaction.go b/core/types/transaction.go
index 6af960b8c3..21f858ecfa 100644
--- a/core/types/transaction.go
+++ b/core/types/transaction.go
@@ -396,14 +396,37 @@ func (tx *Transaction) calcEffectiveGasTip(dst *uint256.Int, baseFee *uint256.In
 	return err
 }
 
+// EffectiveGasTipValue returns the effective gasTip value for the given base fee,
+// even if it would be negative. This can be used for sorting purposes.
+func (tx *Transaction) EffectiveGasTipValue(baseFee *big.Int) *big.Int {
+	// min(gasTipCap, gasFeeCap - baseFee)
+	dst := new(big.Int)
+	if baseFee == nil {
+		dst.Set(tx.inner.gasTipCap())
+		return dst
+	}
+
+	dst.Sub(tx.inner.gasFeeCap(), baseFee) // gasFeeCap - baseFee
+	gasTipCap := tx.inner.gasTipCap()
+	if gasTipCap.Cmp(dst) < 0 { // gasTipCap < (gasFeeCap - baseFee)
+		dst.Set(gasTipCap)
+	}
+	return dst
+}
+
 func (tx *Transaction) EffectiveGasTipCmp(other *Transaction, baseFee *uint256.Int) int {
 	if baseFee == nil {
 		return tx.GasTipCapCmp(other)
 	}
 	// Use more efficient internal method.
 	txTip, otherTip := new(uint256.Int), new(uint256.Int)
-	tx.calcEffectiveGasTip(txTip, baseFee)
-	other.calcEffectiveGasTip(otherTip, baseFee)
+	err1 := tx.calcEffectiveGasTip(txTip, baseFee)
+	err2 := other.calcEffectiveGasTip(otherTip, baseFee)
+	if err1 != nil || err2 != nil {
+		// fall back to big int comparison in case of error
+		base := baseFee.ToBig()
+		return tx.EffectiveGasTipValue(base).Cmp(other.EffectiveGasTipValue(base))
+	}
 	return txTip.Cmp(otherTip)
 }