encoding/json: marshal maps using reflect.Value.MapRange
Map serialization using reflect.Value.MapIndex cannot retrieve
map keys that contain a NaN, resulting in a panic.
Switch the implementation to use the reflect.Value.MapRange method
instead, which iterates over all map entries regardless of whether
they are directly retrievable.
Note that according to RFC 8259, section 4, a JSON object should
have unique names, but does not forbid the occurrence of duplicate names.
Fixes #43207
Change-Id: If4bc55229b1f64b8ca4b0fed37549725efdace39
Reviewed-on: https://go-review.googlesource.com/c/go/+/278632
Trust: Meng Zhuo <mzh@golangcn.org>
Trust: Joe Tsai <thebrokentoaster@gmail.com>
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Meng Zhuo <mzh@golangcn.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Reviewed-by: Daniel Martà <mvdan@mvdan.cc>
diff --git a/src/encoding/json/encode.go b/src/encoding/json/encode.go
index 751f03d..e473e61 100644
--- a/src/encoding/json/encode.go
+++ b/src/encoding/json/encode.go
@@ -794,23 +794,24 @@
e.WriteByte('{')
// Extract and sort the keys.
- keys := v.MapKeys()
- sv := make([]reflectWithString, len(keys))
- for i, v := range keys {
- sv[i].v = v
+ sv := make([]reflectWithString, v.Len())
+ mi := v.MapRange()
+ for i := 0; mi.Next(); i++ {
+ sv[i].k = mi.Key()
+ sv[i].v = mi.Value()
if err := sv[i].resolve(); err != nil {
e.error(fmt.Errorf("json: encoding error for type %q: %q", v.Type().String(), err.Error()))
}
}
- sort.Slice(sv, func(i, j int) bool { return sv[i].s < sv[j].s })
+ sort.Slice(sv, func(i, j int) bool { return sv[i].ks < sv[j].ks })
for i, kv := range sv {
if i > 0 {
e.WriteByte(',')
}
- e.string(kv.s, opts.escapeHTML)
+ e.string(kv.ks, opts.escapeHTML)
e.WriteByte(':')
- me.elemEnc(e, v.MapIndex(kv.v), opts)
+ me.elemEnc(e, kv.v, opts)
}
e.WriteByte('}')
e.ptrLevel--
@@ -997,29 +998,30 @@
}
type reflectWithString struct {
- v reflect.Value
- s string
+ k reflect.Value
+ v reflect.Value
+ ks string
}
func (w *reflectWithString) resolve() error {
- if w.v.Kind() == reflect.String {
- w.s = w.v.String()
+ if w.k.Kind() == reflect.String {
+ w.ks = w.k.String()
return nil
}
- if tm, ok := w.v.Interface().(encoding.TextMarshaler); ok {
- if w.v.Kind() == reflect.Ptr && w.v.IsNil() {
+ if tm, ok := w.k.Interface().(encoding.TextMarshaler); ok {
+ if w.k.Kind() == reflect.Ptr && w.k.IsNil() {
return nil
}
buf, err := tm.MarshalText()
- w.s = string(buf)
+ w.ks = string(buf)
return err
}
- switch w.v.Kind() {
+ switch w.k.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
- w.s = strconv.FormatInt(w.v.Int(), 10)
+ w.ks = strconv.FormatInt(w.k.Int(), 10)
return nil
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
- w.s = strconv.FormatUint(w.v.Uint(), 10)
+ w.ks = strconv.FormatUint(w.k.Uint(), 10)
return nil
}
panic("unexpected map key type")
diff --git a/src/encoding/json/encode_test.go b/src/encoding/json/encode_test.go
index 42bb09d..0dad951 100644
--- a/src/encoding/json/encode_test.go
+++ b/src/encoding/json/encode_test.go
@@ -245,6 +245,22 @@
}
}
+// Issue 43207
+func TestMarshalTextFloatMap(t *testing.T) {
+ m := map[textfloat]string{
+ textfloat(math.NaN()): "1",
+ textfloat(math.NaN()): "1",
+ }
+ got, err := Marshal(m)
+ if err != nil {
+ t.Errorf("Marshal() error: %v", err)
+ }
+ want := `{"TF:NaN":"1","TF:NaN":"1"}`
+ if string(got) != want {
+ t.Errorf("Marshal() = %s, want %s", got, want)
+ }
+}
+
// Ref has Marshaler and Unmarshaler methods with pointer receiver.
type Ref int
@@ -854,6 +870,10 @@
return buf.Bytes(), nil
}
+type textfloat float64
+
+func (f textfloat) MarshalText() ([]byte, error) { return tenc(`TF:%0.2f`, f) }
+
// Issue 13783
func TestEncodeBytekind(t *testing.T) {
testdata := []struct {
@@ -872,6 +892,7 @@
{[]jsonint{5, 4}, `[{"JI":5},{"JI":4}]`},
{[]textint{9, 3}, `["TI:9","TI:3"]`},
{[]int{9, 3}, `[9,3]`},
+ {[]textfloat{12, 3}, `["TF:12.00","TF:3.00"]`},
}
for _, d := range testdata {
js, err := Marshal(d.data)
