From 31c1e0292100b4b6c5b9076780b88aebf5dac07b Mon Sep 17 00:00:00 2001
From: Rader <rader.net@gmail.com>
Date: Thu, 24 May 2018 14:40:02 +0800
Subject: [PATCH] bind: report error if event not not found by name when
 processing log

---
 accounts/abi/bind/base.go      | 31 +++++++++++++++++++++++++------
 accounts/abi/bind/base_test.go | 29 +++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+), 6 deletions(-)
 create mode 100644 accounts/abi/bind/base_test.go

diff --git a/accounts/abi/bind/base.go b/accounts/abi/bind/base.go
index 83ad1c8ae7..ace18cb8af 100644
--- a/accounts/abi/bind/base.go
+++ b/accounts/abi/bind/base.go
@@ -251,8 +251,14 @@ func (c *BoundContract) FilterLogs(opts *FilterOpts, name string, query ...[]int
 	if opts == nil {
 		opts = new(FilterOpts)
 	}
-	// Append the event selector to the query parameters and construct the topic set
-	query = append([][]interface{}{{c.abi.Events[name].Id()}}, query...)
+
+	var e abi.Event
+	var exist bool
+	if e, exist = c.abi.Events[name]; !exist {
+		return nil, nil, fmt.Errorf("abi: event [%v] not found", name)
+	}
+	// Append the event selector to the query parameters and construct the topic seft
+	query = append([][]interface{}{{e.Id()}}, query...)
 
 	topics, err := makeTopics(query...)
 	if err != nil {
@@ -300,8 +306,14 @@ func (c *BoundContract) WatchLogs(opts *WatchOpts, name string, query ...[]inter
 	if opts == nil {
 		opts = new(WatchOpts)
 	}
+	var e abi.Event
+	var exist bool
+	if e, exist = c.abi.Events[name]; !exist {
+		return nil, nil, fmt.Errorf("abi: event [%v] not found", name)
+	}
+
 	// Append the event selector to the query parameters and construct the topic set
-	query = append([][]interface{}{{c.abi.Events[name].Id()}}, query...)
+	query = append([][]interface{}{{e.Id()}}, query...)
 
 	topics, err := makeTopics(query...)
 	if err != nil {
@@ -325,14 +337,21 @@ func (c *BoundContract) WatchLogs(opts *WatchOpts, name string, query ...[]inter
 }
 
 // UnpackLog unpacks a retrieved log into the provided output structure.
-func (c *BoundContract) UnpackLog(out interface{}, event string, log types.Log) error {
+func (c *BoundContract) UnpackLog(out interface{}, eventName string, log types.Log) error {
 	if len(log.Data) > 0 {
-		if err := c.abi.Unpack(out, event, log.Data); err != nil {
+		if err := c.abi.Unpack(out, eventName, log.Data); err != nil {
 			return err
 		}
 	}
+
+	var e abi.Event
+	var exist bool
+	if e, exist = c.abi.Events[eventName]; !exist {
+		return fmt.Errorf("abi: event [%v] not found", eventName)
+	}
+
 	var indexed abi.Arguments
-	for _, arg := range c.abi.Events[event].Inputs {
+	for _, arg := range e.Inputs {
 		if arg.Indexed {
 			indexed = append(indexed, arg)
 		}
diff --git a/accounts/abi/bind/base_test.go b/accounts/abi/bind/base_test.go
new file mode 100644
index 0000000000..0d13702ffc
--- /dev/null
+++ b/accounts/abi/bind/base_test.go
@@ -0,0 +1,29 @@
+package bind
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/accounts/abi"
+	"github.com/ethereum/go-ethereum/core/types"
+)
+
+func TestUnkownEventName(t *testing.T) {
+	errorPrefix := "abi: event"
+	c := &BoundContract{}
+	c.abi.Events = make(map[string]abi.Event)
+	c.abi.Events["event1"] = abi.Event{}
+	if _, _, err := c.FilterLogs(nil, "event_not_exist"); err == nil || !strings.HasPrefix(err.Error(), errorPrefix) {
+		t.Fatal("should report error if event not found")
+	}
+
+	if _, _, err := c.WatchLogs(nil, "event_not_exist"); err == nil || !strings.HasPrefix(err.Error(), errorPrefix) {
+		t.Fatal("should report error if event not found")
+	}
+
+	var v interface{}
+	elog := types.Log{}
+	if err := c.UnpackLog(v, "event_not_exist", elog); err == nil || !strings.HasPrefix(err.Error(), errorPrefix) {
+		t.Fatal("should report error if event not found")
+	}
+}