accounts/abi: add another unpack interface

1 files changed, 3 insertions, 3 deletions

diff --git a/accounts/abi/abi.go b/accounts/abi/abi.go
index abcb403db..32f041890 100644
--- a/accounts/abi/abi.go
+++ b/accounts/abi/abi.go
@@ -136,11 +136,11 @@ func (abi *ABI) UnmarshalJSON(data []byte) error {
 
 // MethodById looks up a method by the 4-byte id
 // returns nil if none found
-func (abi *ABI) MethodById(sigdata []byte) *Method {
+func (abi *ABI) MethodById(sigdata []byte) (*Method, error){
 	for _, method := range abi.Methods {
 		if bytes.Equal(method.Id(), sigdata[:4]) {
-			return &method
+			return &method, nil
 		}
 	}
-	return nil
+	return nil, fmt.Errorf("ABI spec does not contain method signature in data: 0x%x", sigdata[:4])
 }