panic on unmarshal

[LaconisIves]

package main

import (
"encoding/json"
"github.com/json-iterator/go"
"log"
)

type T struct {
X int
}

type TT struct {
T *T
}

func main() {
data := []byte({"A":0})
var t *T
// return non-nil error
if err := json.Unmarshal(data, t); err != nil {
log.Println(err)
}
// return nil error
if err := jsoniter.Unmarshal(data, t); err != nil {
log.Println(err)
}
var tt *TT
// return non-nil error
if err := json.Unmarshal(data, tt.T); err != nil {
log.Println(err)
}
// panic
if err := jsoniter.Unmarshal(data, tt.T); err != nil {
log.Println(err)
}
}

[taowen]

json.Unmarshal(data, tt.T);

isn't tt being nil at this point?