From c966eaa031f68f22895faae3b0db0ac32a8d6cd7 Mon Sep 17 00:00:00 2001
From: Tao Wen <taowen@gmail.com>
Date: Tue, 18 Jul 2017 11:05:39 +0800
Subject: [PATCH] #135 fix double negative

---
 feature_iter_float.go    | 16 ++++++++++++++++
 jsoniter_invalid_test.go | 13 +++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/feature_iter_float.go b/feature_iter_float.go
index 57693d6..5451911 100644
--- a/feature_iter_float.go
+++ b/feature_iter_float.go
@@ -159,6 +159,14 @@ func (iter *Iterator) readFloat32SlowPath() (ret float32) {
 	if iter.Error != nil && iter.Error != io.EOF {
 		return
 	}
+	if len(str) == 0 {
+		iter.ReportError("readFloat32SlowPath", "empty number")
+		return
+	}
+	if str[0] == '-' {
+		iter.ReportError("readFloat32SlowPath", "-- is not valid")
+		return
+	}
 	val, err := strconv.ParseFloat(str, 32)
 	if err != nil {
 		iter.Error = err
@@ -233,6 +241,14 @@ func (iter *Iterator) readFloat64SlowPath() (ret float64) {
 	if iter.Error != nil && iter.Error != io.EOF {
 		return
 	}
+	if len(str) == 0 {
+		iter.ReportError("readFloat64SlowPath", "empty number")
+		return
+	}
+	if str[0] == '-' {
+		iter.ReportError("readFloat64SlowPath", "-- is not valid")
+		return
+	}
 	val, err := strconv.ParseFloat(str, 64)
 	if err != nil {
 		iter.Error = err
diff --git a/jsoniter_invalid_test.go b/jsoniter_invalid_test.go
index f186ae4..5b36f2b 100644
--- a/jsoniter_invalid_test.go
+++ b/jsoniter_invalid_test.go
@@ -3,6 +3,7 @@ package jsoniter
 import (
 	"github.com/stretchr/testify/require"
 	"testing"
+	"encoding/json"
 )
 
 func Test_missing_object_end(t *testing.T) {
@@ -65,3 +66,15 @@ func Test_invalid_array_input(t *testing.T) {
 	obj := [0]string{}
 	should.NotNil(Unmarshal(input, &obj))
 }
+
+func Test_double_negative(t *testing.T) {
+	should := require.New(t)
+	var v interface{}
+	should.NotNil(json.Unmarshal([]byte(`--2`), &v))
+	var vFloat64 float64
+	should.NotNil(UnmarshalFromString(`--2`, &vFloat64))
+	var vFloat32 float32
+	should.NotNil(UnmarshalFromString(`--2`, &vFloat32))
+	var vInt int
+	should.NotNil(UnmarshalFromString(`--2`, &vInt))
+}