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author | Russ Cox <rsc@golang.org> | 2012-06-13 16:24:48 -0400 |
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committer | Russ Cox <rsc@golang.org> | 2012-06-13 16:24:48 -0400 |
commit | dc0f7d6fde051ce00337af31351120b203825863 (patch) | |
tree | f02e8bc226c1b950f2c89cfdcc0f39963b3e7d23 | |
parent | cec2715018b9adbc518eccbf7022b48bc2e3403f (diff) | |
download | go-dc0f7d6fde051ce00337af31351120b203825863.tar.gz go-dc0f7d6fde051ce00337af31351120b203825863.zip |
[release-branch.go1] encoding/json: fix panic unmarshaling into non-nil interface value
««« backport bee83c1509a3
encoding/json: fix panic unmarshaling into non-nil interface value
Fixes #3614.
R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/6306051
»»»
-rw-r--r-- | src/pkg/encoding/json/decode.go | 9 | ||||
-rw-r--r-- | src/pkg/encoding/json/decode_test.go | 46 |
2 files changed, 53 insertions, 2 deletions
diff --git a/src/pkg/encoding/json/decode.go b/src/pkg/encoding/json/decode.go index dcfdeec3c5..d61f887064 100644 --- a/src/pkg/encoding/json/decode.go +++ b/src/pkg/encoding/json/decode.go @@ -273,9 +273,14 @@ func (d *decodeState) indirect(v reflect.Value, decodingNull bool) (Unmarshaler, _, isUnmarshaler = v.Interface().(Unmarshaler) } + // Load value from interface, but only if the result will be + // usefully addressable. if iv := v; iv.Kind() == reflect.Interface && !iv.IsNil() { - v = iv.Elem() - continue + e := iv.Elem() + if e.Kind() == reflect.Ptr && !e.IsNil() && (!decodingNull || e.Elem().Kind() == reflect.Ptr) { + v = e + continue + } } pv := v diff --git a/src/pkg/encoding/json/decode_test.go b/src/pkg/encoding/json/decode_test.go index 2a7549cb68..6fac22c4a3 100644 --- a/src/pkg/encoding/json/decode_test.go +++ b/src/pkg/encoding/json/decode_test.go @@ -657,3 +657,49 @@ func TestEmptyString(t *testing.T) { t.Fatal("Decode: did not set Number1") } } + +func intp(x int) *int { + p := new(int) + *p = x + return p +} + +func intpp(x *int) **int { + pp := new(*int) + *pp = x + return pp +} + +var interfaceSetTests = []struct { + pre interface{} + json string + post interface{} +}{ + {"foo", `"bar"`, "bar"}, + {"foo", `2`, 2.0}, + {"foo", `true`, true}, + {"foo", `null`, nil}, + + {nil, `null`, nil}, + {new(int), `null`, nil}, + {(*int)(nil), `null`, nil}, + {new(*int), `null`, new(*int)}, + {(**int)(nil), `null`, nil}, + {intp(1), `null`, nil}, + {intpp(nil), `null`, intpp(nil)}, + {intpp(intp(1)), `null`, intpp(nil)}, +} + +func TestInterfaceSet(t *testing.T) { + for _, tt := range interfaceSetTests { + b := struct{ X interface{} }{tt.pre} + blob := `{"X":` + tt.json + `}` + if err := Unmarshal([]byte(blob), &b); err != nil { + t.Errorf("Unmarshal %#q: %v", blob, err) + continue + } + if !reflect.DeepEqual(b.X, tt.post) { + t.Errorf("Unmarshal %#q into %#v: X=%#v, want %#v", blob, tt.pre, b.X, tt.post) + } + } +} |