From f8e3b92816623ea46365093d69452201a77ab810 Mon Sep 17 00:00:00 2001
From: Daniel Liu <liudaniel@qq.com>
Date: Tue, 14 Jan 2025 10:56:15 +0800
Subject: [PATCH] accounts/abi/bind: handle UnpackLog with zero topics (#26920)

Adds error handling for the case that UnpackLog or UnpackLogIntoMap is called with a log that has zero topics.

---------

Co-authored-by: Sina Mahmoodi <itz.s1na@gmail.com>
---
 accounts/abi/bind/base.go      | 15 ++++++++++-----
 accounts/abi/bind/base_test.go | 17 +++++++++++++++++
 2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/accounts/abi/bind/base.go b/accounts/abi/bind/base.go
index 36472f81fe18..abd2e7ad45ba 100644
--- a/accounts/abi/bind/base.go
+++ b/accounts/abi/bind/base.go
@@ -32,12 +32,13 @@ import (
 	"github.com/XinFinOrg/XDPoSChain/event"
 )
 
+const basefeeWiggleMultiplier = 2
+
 var (
-	errNoEventSignature = errors.New("no event signature")
+	errNoEventSignature       = errors.New("no event signature")
+	errEventSignatureMismatch = errors.New("event signature mismatch")
 )
 
-const basefeeWiggleMultiplier = 2
-
 // SignerFn is a signer function callback when a contract requires a method to
 // sign the transaction before submission.
 type SignerFn func(common.Address, *types.Transaction) (*types.Transaction, error)
@@ -494,7 +495,7 @@ func (c *BoundContract) UnpackLog(out interface{}, event string, log types.Log)
 		return errNoEventSignature
 	}
 	if log.Topics[0] != c.abi.Events[event].ID {
-		return errors.New("event signature mismatch")
+		return errEventSignatureMismatch
 	}
 	if len(log.Data) > 0 {
 		if err := c.abi.UnpackIntoInterface(out, event, log.Data); err != nil {
@@ -512,8 +513,12 @@ func (c *BoundContract) UnpackLog(out interface{}, event string, log types.Log)
 
 // UnpackLogIntoMap unpacks a retrieved log into the provided map.
 func (c *BoundContract) UnpackLogIntoMap(out map[string]interface{}, event string, log types.Log) error {
+	// Anonymous events are not supported.
+	if len(log.Topics) == 0 {
+		return errNoEventSignature
+	}
 	if log.Topics[0] != c.abi.Events[event].ID {
-		return fmt.Errorf("event signature mismatch")
+		return errEventSignatureMismatch
 	}
 	if len(log.Data) > 0 {
 		if err := c.abi.UnpackIntoMap(out, event, log.Data); err != nil {
diff --git a/accounts/abi/bind/base_test.go b/accounts/abi/bind/base_test.go
index 97972b352e85..d46ab88b8306 100644
--- a/accounts/abi/bind/base_test.go
+++ b/accounts/abi/bind/base_test.go
@@ -219,6 +219,23 @@ func TestUnpackIndexedStringTyLogIntoMap(t *testing.T) {
 	unpackAndCheck(t, bc, expectedReceivedMap, mockLog)
 }
 
+func TestUnpackAnonymousLogIntoMap(t *testing.T) {
+	mockLog := newMockLog(nil, common.HexToHash("0x0"))
+
+	abiString := `[{"anonymous":false,"inputs":[{"indexed":false,"name":"amount","type":"uint256"}],"name":"received","type":"event"}]`
+	parsedAbi, _ := abi.JSON(strings.NewReader(abiString))
+	bc := bind.NewBoundContract(common.HexToAddress("0x0"), parsedAbi, nil, nil, nil)
+
+	var received map[string]interface{}
+	err := bc.UnpackLogIntoMap(received, "received", mockLog)
+	if err == nil {
+		t.Error("unpacking anonymous event is not supported")
+	}
+	if err.Error() != "no event signature" {
+		t.Errorf("expected error 'no event signature', got '%s'", err)
+	}
+}
+
 func TestUnpackIndexedSliceTyLogIntoMap(t *testing.T) {
 	sliceBytes, err := rlp.EncodeToBytes([]string{"name1", "name2", "name3", "name4"})
 	if err != nil {