From 1d2420323ca555f8ac45969bd39415c5e619e4e0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A9ter=20Szil=C3=A1gyi?= <peterke@gmail.com>
Date: Thu, 13 Aug 2015 11:12:38 +0300
Subject: [PATCH] rlp: add support for boolean encoding/decoding

---
 rlp/decode.go      | 29 +++++++++++++++++++++++++++++
 rlp/decode_test.go |  9 +++++++++
 rlp/encode.go      | 11 +++++++++++
 rlp/encode_test.go |  4 ++++
 4 files changed, 53 insertions(+)

diff --git a/rlp/decode.go b/rlp/decode.go
index c0b5f06994..1381f5274e 100644
--- a/rlp/decode.go
+++ b/rlp/decode.go
@@ -183,6 +183,8 @@ func makeDecoder(typ reflect.Type, tags tags) (dec decoder, err error) {
 		return decodeBigIntNoPtr, nil
 	case isUint(kind):
 		return decodeUint, nil
+	case kind == reflect.Bool:
+		return decodeBool, nil
 	case kind == reflect.String:
 		return decodeString, nil
 	case kind == reflect.Slice || kind == reflect.Array:
@@ -211,6 +213,15 @@ func decodeUint(s *Stream, val reflect.Value) error {
 	return nil
 }
 
+func decodeBool(s *Stream, val reflect.Value) error {
+	b, err := s.Bool()
+	if err != nil {
+		return wrapStreamError(err, val.Type())
+	}
+	val.SetBool(b)
+	return nil
+}
+
 func decodeString(s *Stream, val reflect.Value) error {
 	b, err := s.Bytes()
 	if err != nil {
@@ -697,6 +708,24 @@ func (s *Stream) uint(maxbits int) (uint64, error) {
 	}
 }
 
+// Bool reads an RLP string of up to 1 byte and returns its contents
+// as an boolean. If the input does not contain an RLP string, the
+// returned error will be ErrExpectedString.
+func (s *Stream) Bool() (bool, error) {
+	num, err := s.uint(8)
+	if err != nil {
+		return false, err
+	}
+	switch num {
+	case 0:
+		return false, nil
+	case 1:
+		return true, nil
+	default:
+		return false, fmt.Errorf("rlp: invalid boolean value: %d", num)
+	}
+}
+
 // List starts decoding an RLP list. If the input does not contain a
 // list, the returned error will be ErrExpectedList. When the list's
 // end has been reached, any Stream operation will return EOL.
diff --git a/rlp/decode_test.go b/rlp/decode_test.go
index 331faa9d83..d6b0611dd0 100644
--- a/rlp/decode_test.go
+++ b/rlp/decode_test.go
@@ -19,6 +19,7 @@ package rlp
 import (
 	"bytes"
 	"encoding/hex"
+	"errors"
 	"fmt"
 	"io"
 	"math/big"
@@ -116,6 +117,9 @@ func TestStreamErrors(t *testing.T) {
 		{"817F", calls{"Uint"}, nil, ErrCanonSize},
 		{"8180", calls{"Uint"}, nil, nil},
 
+		// Non-valid boolean
+		{"02", calls{"Bool"}, nil, errors.New("rlp: invalid boolean value: 2")},
+
 		// Size tags must use the smallest possible encoding.
 		// Leading zero bytes in the size tag are also rejected.
 		{"8100", calls{"Uint"}, nil, ErrCanonSize},
@@ -315,6 +319,11 @@ var (
 )
 
 var decodeTests = []decodeTest{
+	// booleans
+	{input: "01", ptr: new(bool), value: true},
+	{input: "80", ptr: new(bool), value: false},
+	{input: "02", ptr: new(bool), error: "rlp: invalid boolean value: 2"},
+
 	// integers
 	{input: "05", ptr: new(uint32), value: uint32(5)},
 	{input: "80", ptr: new(uint32), value: uint32(0)},
diff --git a/rlp/encode.go b/rlp/encode.go
index 0ddef7bbb5..b525ae4e7a 100644
--- a/rlp/encode.go
+++ b/rlp/encode.go
@@ -361,6 +361,8 @@ func makeWriter(typ reflect.Type) (writer, error) {
 		return writeBigIntNoPtr, nil
 	case isUint(kind):
 		return writeUint, nil
+	case kind == reflect.Bool:
+		return writeBool, nil
 	case kind == reflect.String:
 		return writeString, nil
 	case kind == reflect.Slice && isByte(typ.Elem()):
@@ -398,6 +400,15 @@ func writeUint(val reflect.Value, w *encbuf) error {
 	return nil
 }
 
+func writeBool(val reflect.Value, w *encbuf) error {
+	if val.Bool() {
+		w.str = append(w.str, 0x01)
+	} else {
+		w.str = append(w.str, 0x80)
+	}
+	return nil
+}
+
 func writeBigIntPtr(val reflect.Value, w *encbuf) error {
 	ptr := val.Interface().(*big.Int)
 	if ptr == nil {
diff --git a/rlp/encode_test.go b/rlp/encode_test.go
index e83c76b51e..60bd956926 100644
--- a/rlp/encode_test.go
+++ b/rlp/encode_test.go
@@ -71,6 +71,10 @@ type encTest struct {
 }
 
 var encTests = []encTest{
+	// booleans
+	{val: true, output: "01"},
+	{val: false, output: "80"},
+
 	// integers
 	{val: uint32(0), output: "80"},
 	{val: uint32(127), output: "7F"},