Merge pull request #31 from nicholas-wright-bjss/master

Fix for recursive structs

jingo_test.go

@@ -170,14 +170,44 @@ func Test_StructWithEscapes(t *testing.T) {
 
 	// Compare result
 	if resultJSON != wantJSON {
-		t.Errorf("Test_StructWithScapes Failed: want JSON:" + wantJSON + " got JSON:" + resultJSON)
+		t.Errorf("Test_StructWithEscapes Failed: want JSON:" + wantJSON + " got JSON:" + resultJSON)
 	}
 
 	andBackAgain := StructWithEscapes{}
 	json.Unmarshal([]byte(resultJSON), &andBackAgain)
 
 	if !reflect.DeepEqual(es, andBackAgain) {
-		t.Errorf("Test_StructWithScapes Failed: want: %+v got: %+v", es, andBackAgain)
+		t.Errorf("Test_StructWithEscapes Failed: want: %+v got: %+v", es, andBackAgain)
+	}
+}
+
+func Test_StructWithRecursion(t *testing.T) {
+
+	type structWithRecursion struct {
+		Name  string               `json:"name"`
+		Child *structWithRecursion `json:"child"`
+	}
+
+	v := structWithRecursion{
+		Name: "A",
+		Child: &structWithRecursion{
+			Name: "B",
+			Child: &structWithRecursion{
+				Name:  "C",
+				Child: nil,
+			},
+		},
+	}
+
+	wantJSON := `{"name":"A","child":{"name":"B","child":{"name":"C","child":null}}}`
+
+	var enc = NewStructEncoder(structWithRecursion{})
+	buf := NewBufferFromPool()
+	enc.Marshal(&v, buf)
+
+	resultJSON := buf.String()
+	if resultJSON != wantJSON {
+		t.Errorf("Test_StructWithRecursion Failed: want JSON:" + wantJSON + " got JSON:" + resultJSON)
 	}
 }
 
@@ -508,8 +538,6 @@ func BenchmarkSliceStdLib(b *testing.B) {
 // var fakeType = LargePayload{}
 // var fake = NewLargePayload()
 
-//
-//
 var s = "test pointer string b"
 var fakeType = all{}
 var fake = &all{

structencoder.go

@@ -346,7 +346,15 @@ func (e *StructEncoder) valueInst(k reflect.Kind, instr func(func(unsafe.Pointer
 
 			/// now cater for it being a pointer to a struct
 			var inf = reflect.New(reflect.TypeOf(e.t).Field(e.i).Type.Elem()).Elem().Interface()
-			enc := NewStructEncoder(inf)
+
+			var enc *StructEncoder
+			if e.t == inf {
+				// handle recursive structs by re-using the current encoder
+				enc = e
+			} else {
+				enc = NewStructEncoder(inf)
+			}
+
 			// now create an instruction to marshal the field
 			f := e.f
 			e.appendInstructionFun(func(v unsafe.Pointer, w *Buffer) {