From: Ryan Slade <ryanslade@gmail.com>
Date: Sun, 30 Dec 2012 04:40:42 +0000 (+1100)
Subject: encoding/json: encode map key is of string kind, decode only of string type
X-Git-Tag: go1.1rc2~1513
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=a4600126d9e4fcbd8e9ea3072eff7ea5822f2014;p=gostls13.git

encoding/json: encode map key is of string kind, decode only of string type

Allows encoding and decoding of maps with key of string kind, not just string type.
Fixes #3519.

R=rsc, dave
CC=golang-dev
https://golang.org/cl/6943047
---

diff --git a/src/pkg/encoding/json/decode.go b/src/pkg/encoding/json/decode.go
index b46dac96f5..93a8eb8e92 100644
--- a/src/pkg/encoding/json/decode.go
+++ b/src/pkg/encoding/json/decode.go
@@ -430,9 +430,9 @@ func (d *decodeState) object(v reflect.Value) {
 	// Check type of target: struct or map[string]T
 	switch v.Kind() {
 	case reflect.Map:
-		// map must have string type
+		// map must have string kind
 		t := v.Type()
-		if t.Key() != reflect.TypeOf("") {
+		if t.Key().Kind() != reflect.String {
 			d.saveError(&UnmarshalTypeError{"object", v.Type()})
 			break
 		}
@@ -536,10 +536,12 @@ func (d *decodeState) object(v reflect.Value) {
 		} else {
 			d.value(subv)
 		}
+
 		// Write value back to map;
 		// if using struct, subv points into struct already.
 		if v.Kind() == reflect.Map {
-			v.SetMapIndex(reflect.ValueOf(key), subv)
+			kv := reflect.ValueOf(key).Convert(v.Type().Key())
+			v.SetMapIndex(kv, subv)
 		}
 
 		// Next token must be , or }.
diff --git a/src/pkg/encoding/json/decode_test.go b/src/pkg/encoding/json/decode_test.go
index b9fad0597a..4f334d1347 100644
--- a/src/pkg/encoding/json/decode_test.go
+++ b/src/pkg/encoding/json/decode_test.go
@@ -1000,3 +1000,28 @@ func TestUnmarshalNulls(t *testing.T) {
 		t.Errorf("Unmarshal of null values affected primitives")
 	}
 }
+
+func TestStringKind(t *testing.T) {
+	type stringKind string
+	type aMap map[stringKind]int
+
+	var m1, m2 map[stringKind]int
+	m1 = map[stringKind]int{
+		"foo": 42,
+	}
+
+	data, err := Marshal(m1)
+	if err != nil {
+		t.Errorf("Unexpected error marshalling: %v", err)
+	}
+
+	err = Unmarshal(data, &m2)
+	if err != nil {
+		t.Errorf("Unexpected error unmarshalling: %v", err)
+	}
+
+	if !reflect.DeepEqual(m1, m2) {
+		t.Error("Items should be equal after encoding and then decoding")
+	}
+
+}