Fix panics for embedded unexported types

decode_test.go

@@ -802,6 +802,12 @@ var unmarshalTests = []struct {
 			"c": []interface{}{"d", "e"},
 		},
 	},
+
+	// Unexported embedded type
+	{
+		"a: exported\nunexportedb: null\n",
+		map[string]interface{}{"a": "exported", "unexportedb": interface{}(nil)},
+	},
 }
 
 type M map[string]interface{}
@@ -820,6 +826,15 @@ type inlineD struct {
 	D int
 }
 
+type UnexportedA struct {
+	A string
+	unexportedB
+}
+
+type unexportedB struct {
+	B string
+}
+
 func (s *S) TestUnmarshal(c *C) {
 	for i, item := range unmarshalTests {
 		c.Logf("test %d: %q", i, item.data)
@@ -947,7 +962,7 @@ var unmarshalErrorTests = []struct {
 	{"%TAG !%79! tag:yaml.org,2002:\n---\nv: !%79!int '1'", "yaml: did not find expected whitespace"},
 	{"a:\n  1:\nb\n  2:", ".*could not find expected ':'"},
 	{"a: 1\nb: 2\nc 2\nd: 3\n", "^yaml: line 3: could not find expected ':'$"},
-	{"#\n-\n{", "yaml: line 3: could not find expected ':'"}, // Issue #665
+	{"#\n-\n{", "yaml: line 3: could not find expected ':'"},   // Issue #665
 	{"0: [:!00 \xef", "yaml: incomplete UTF-8 octet sequence"}, // Issue #666
 	{
 		"a: &a [00,00,00,00,00,00,00,00,00]\n" +
@@ -1482,7 +1497,7 @@ func (s *S) TestMergeNestedStruct(c *C) {
 	// 2) A simple implementation might attempt to handle the key skipping
 	//    directly by iterating over the merging map without recursion, but
 	//    there are more complex cases that require recursion.
-	// 
+	//
 	// Quick summary of the fields:
 	//
 	// - A must come from outer and not overriden
@@ -1498,7 +1513,7 @@ func (s *S) TestMergeNestedStruct(c *C) {
 		A, B, C int
 	}
 	type Outer struct {
-		D, E      int
+		D, E   int
 		Inner  Inner
 		Inline map[string]int `yaml:",inline"`
 	}
@@ -1516,10 +1531,10 @@ func (s *S) TestMergeNestedStruct(c *C) {
 	// Repeat test with a map.
 
 	var testm map[string]interface{}
-	var wantm = map[string]interface {} {
-		"f":     60,
+	var wantm = map[string]interface{}{
+		"f": 60,
 		"inner": map[string]interface{}{
-		    "a": 10,
+			"a": 10,
 		},
 		"d": 40,
 		"e": 50,

encode.go

@@ -110,7 +110,7 @@ func (e *encoder) marshalDoc(tag string, in reflect.Value) {
 
 func (e *encoder) marshal(tag string, in reflect.Value) {
 	tag = shortTag(tag)
-	if !in.IsValid() || in.Kind() == reflect.Ptr && in.IsNil() {
+	if !in.IsValid() || !in.CanInterface() || in.Kind() == reflect.Ptr && in.IsNil() {
 		e.nilv()
 		return
 	}

encode_test.go

@@ -494,6 +494,12 @@ var marshalTests = []struct {
 		},
 		"value: !!seq []\n",
 	},
+
+	// unexported embedded type
+	{
+		UnexportedA{A: "exported"},
+		"a: exported\nunexportedb: null\n",
+	},
 }
 
 func (s *S) TestMarshal(c *C) {