From afd41ce587ac72edb4a511ca7635712701bc2ced Mon Sep 17 00:00:00 2001
From: Sam Wilson <sam.wilson@consensys.net>
Date: Mon, 1 Jun 2020 12:57:23 -0400
Subject: [PATCH] Store the gas price popped by PAYGAS

---
 core/vm/instructions.go | 11 +++++++----
 core/vm/interpreter.go  |  2 ++
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/core/vm/instructions.go b/core/vm/instructions.go
index 5c0d4dbc2524..30fe5e3a4ce8 100644
--- a/core/vm/instructions.go
+++ b/core/vm/instructions.go
@@ -903,13 +903,16 @@ func makeLog(size int) executionFunc {
 }
 
 func opPaygas(pc *uint64, interpreter *EVMInterpreter, callContext *callCtx) ([]byte, error) {
-
-	// TODO: Store the popped value
-	if interpreter.paygasMode != PaygasNoOp {
+	gasprice := callContext.stack.pop()
+	if interpreter.paygasMode == PaygasNoOp {
+		interpreter.intPool.put(gasprice)
+	} else {
+		// TODO: Check the computed value against the GasPrice set in the tx
 		interpreter.evm.snapshots[len(interpreter.evm.snapshots)-1] = interpreter.evm.StateDB.Snapshot()
 		interpreter.paygasMode = PaygasNoOp
+		interpreter.paygasPrice = gasprice
 	}
-	interpreter.intPool.put(callContext.stack.pop())
+
 	return nil, nil
 }
 
diff --git a/core/vm/interpreter.go b/core/vm/interpreter.go
index aae3e7859ce0..dd08b5127192 100644
--- a/core/vm/interpreter.go
+++ b/core/vm/interpreter.go
@@ -18,6 +18,7 @@ package vm
 
 import (
 	"hash"
+	"math/big"
 	"sync/atomic"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -87,6 +88,7 @@ type EVMInterpreter struct {
 	cfg Config
 
 	paygasMode PaygasMode
+	paygasPrice *big.Int
 
 	intPool *intPool