accounts/abi: add support for anonymous events

accounts/abi/abi.go

@@ -345,12 +345,13 @@ func (abi ABI) Unpack(v interface{}, name string, output []byte) error {
 
 func (abi *ABI) UnmarshalJSON(data []byte) error {
 	var fields []struct {
-		Type     string
-		Name     string
-		Constant bool
-		Indexed  bool
-		Inputs   []Argument
-		Outputs  []Argument
+		Type      string
+		Name      string
+		Constant  bool
+		Indexed   bool
+		Anonymous bool
+		Inputs    []Argument
+		Outputs   []Argument
 	}
 
 	if err := json.Unmarshal(data, &fields); err != nil {
@@ -375,8 +376,9 @@ func (abi *ABI) UnmarshalJSON(data []byte) error {
 			}
 		case "event":
 			abi.Events[field.Name] = Event{
-				Name:   field.Name,
-				Inputs: field.Inputs,
+				Name:      field.Name,
+				Anonymous: field.Anonymous,
+				Inputs:    field.Inputs,
 			}
 		}
 	}

accounts/abi/abi_test.go

@@ -752,23 +752,35 @@ func TestDefaultFunctionParsing(t *testing.T) {
 func TestBareEvents(t *testing.T) {
 	const definition = `[
 	{ "type" : "event", "name" : "balance" },
-	{ "type" : "event", "name" : "name" }]`
+	{ "type" : "event", "name" : "name" },
+	{ "type" : "event", "name" : "anon", "anonymous" : true}]`
 
 	abi, err := JSON(strings.NewReader(definition))
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	if len(abi.Events) != 2 {
-		t.Error("expected 2 events")
+	if len(abi.Events) != 3 {
+		t.Error("expected 3 events")
 	}
 
 	if _, ok := abi.Events["balance"]; !ok {
 		t.Error("expected 'balance' event to be present")
 	}
 
-	if _, ok := abi.Events["name"]; !ok {
+	if ev, ok := abi.Events["name"]; !ok {
 		t.Error("expected 'name' event to be present")
+	} else if ev.Anonymous {
+		t.Errorf("expected 'name' to have the Anonymous field set to false")
+	}
+
+	anonEvent, ok := abi.Events["anon"]
+	if ok {
+		if !anonEvent.Anonymous {
+			t.Errorf("expected anon event to have the Anonymous field set to true")
+		}
+	} else {
+		t.Errorf("expected 'anon' event to be present")
 	}
 }
 

accounts/abi/event.go

@@ -25,10 +25,12 @@ import (
 )
 
 // Event is an event potentially triggered by the EVM's LOG mechanism. The Event
-// holds type information (inputs) about the yielded output
+// holds type information (inputs) about the yielded output. Anonymous events
+// don't get the signature canonical representation as the first LOG topic.
 type Event struct {
-	Name   string
-	Inputs []Argument
+	Name      string
+	Anonymous bool
+	Inputs    []Argument
 }
 
 // Id returns the canonical representation of the event's signature used by the