encoding/json: don't marshal special float values

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/5500084

diff --git a/src/pkg/encoding/json/encode.go b/src/pkg/encoding/json/encode.go
index 3d2f4fc316ea8e837995399d637851d3832ac7c3..033da2d0ade140aff6389f0e886c99645f4cc203 100644 (file)
--- a/src/pkg/encoding/json/encode.go
+++ b/src/pkg/encoding/json/encode.go
@@ -12,6 +12,7 @@ package json
 import (
        "bytes"
        "encoding/base64"
+       "math"
        "reflect"
        "runtime"
        "sort"
@@ -170,6 +171,15 @@ func (e *UnsupportedTypeError) Error() string {
        return "json: unsupported type: " + e.Type.String()
 }
 
+type UnsupportedValueError struct {
+       Value reflect.Value
+       Str   string
+}
+
+func (e *UnsupportedValueError) Error() string {
+       return "json: unsupported value: " + e.Str
+}
+
 type InvalidUTF8Error struct {
        S string
 }
@@ -290,7 +300,11 @@ func (e *encodeState) reflectValueQuoted(v reflect.Value, quoted bool) {
                        e.Write(b)
                }
        case reflect.Float32, reflect.Float64:
-               b := strconv.AppendFloat(e.scratch[:0], v.Float(), 'g', -1, v.Type().Bits())
+               f := v.Float()
+               if math.IsInf(f, 0) || math.IsNaN(f) {
+                       e.error(&UnsupportedValueError{v, strconv.FormatFloat(f, 'g', -1, v.Type().Bits())})
+               }
+               b := strconv.AppendFloat(e.scratch[:0], f, 'g', -1, v.Type().Bits())
                if quoted {
                        writeString(e, string(b))
                } else {

diff --git a/src/pkg/encoding/json/encode_test.go b/src/pkg/encoding/json/encode_test.go
index 9366589f252e71b710cd5a4e2bab7cca8a2c733c..0e39559a463405ccbe164cd24794737dc2f37481 100644 (file)
--- a/src/pkg/encoding/json/encode_test.go
+++ b/src/pkg/encoding/json/encode_test.go
@@ -6,6 +6,7 @@ package json
 
 import (
        "bytes"
+       "math"
        "reflect"
        "testing"
 )
@@ -107,3 +108,21 @@ func TestEncodeRenamedByteSlice(t *testing.T) {
                t.Errorf(" got %s want %s", result, expect)
        }
 }
+
+var unsupportedValues = []interface{}{
+       math.NaN(),
+       math.Inf(-1),
+       math.Inf(1),
+}
+
+func TestUnsupportedValues(t *testing.T) {
+       for _, v := range unsupportedValues {
+               if _, err := Marshal(v); err != nil {
+                       if _, ok := err.(*UnsupportedValueError); !ok {
+                               t.Errorf("for %v, got %T want UnsupportedValueError", v, err)
+                       }
+               } else {
+                       t.Errorf("for %v, expected error", v)
+               }
+       }
+}