libgo: update to go1.15rc1

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/245157

17 files changed, 352 insertions, 45 deletions

diff --git a/libgo/go/encoding/asn1/asn1.go b/libgo/go/encoding/asn1/asn1.go
index fd4dd68..d809dde 100644
--- a/libgo/go/encoding/asn1/asn1.go
+++ b/libgo/go/encoding/asn1/asn1.go
@@ -313,6 +313,12 @@ func parseBase128Int(bytes []byte, initOffset int) (ret, offset int, err error)
 		}
 		ret64 <<= 7
 		b := bytes[offset]
+		// integers should be minimally encoded, so the leading octet should
+		// never be 0x80
+		if shifted == 0 && b == 0x80 {
+			err = SyntaxError{"integer is not minimally encoded"}
+			return
+		}
 		ret64 |= int64(b & 0x7f)
 		offset++
 		if b&0x80 == 0 {
@@ -1031,6 +1037,12 @@ func setDefaultValue(v reflect.Value, params fieldParameters) (ok bool) {
 // Because Unmarshal uses the reflect package, the structs
 // being written to must use upper case field names.
 //
+// After parsing b, any bytes that were leftover and not used to fill
+// val will be returned in rest. When parsing a SEQUENCE into a struct,
+// any trailing elements of the SEQUENCE that do not have matching
+// fields in val will not be included in rest, as these are considered
+// valid elements of the SEQUENCE and not trailing data.
+//
 // An ASN.1 INTEGER can be written to an int, int32, int64,
 // or *big.Int (from the math/big package).
 // If the encoded value does not fit in the Go type,
diff --git a/libgo/go/encoding/asn1/asn1_test.go b/libgo/go/encoding/asn1/asn1_test.go
index d5649bf..8daae97 100644
--- a/libgo/go/encoding/asn1/asn1_test.go
+++ b/libgo/go/encoding/asn1/asn1_test.go
@@ -1129,3 +1129,15 @@ func TestBMPString(t *testing.T) {
 		}
 	}
 }
+
+func TestNonMinimalEncodedOID(t *testing.T) {
+	h, err := hex.DecodeString("060a2a80864886f70d01010b")
+	if err != nil {
+		t.Fatalf("failed to decode from hex string: %s", err)
+	}
+	var oid ObjectIdentifier
+	_, err = Unmarshal(h, &oid)
+	if err == nil {
+		t.Fatalf("accepted non-minimally encoded oid")
+	}
+}
diff --git a/libgo/go/encoding/asn1/marshal.go b/libgo/go/encoding/asn1/marshal.go
index c9ae2ca..0d34d5a 100644
--- a/libgo/go/encoding/asn1/marshal.go
+++ b/libgo/go/encoding/asn1/marshal.go
@@ -5,10 +5,12 @@
 package asn1
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 	"math/big"
 	"reflect"
+	"sort"
 	"time"
 	"unicode/utf8"
 )
@@ -78,6 +80,48 @@ func (m multiEncoder) Encode(dst []byte) {
 	}
 }
 
+type setEncoder []encoder
+
+func (s setEncoder) Len() int {
+	var size int
+	for _, e := range s {
+		size += e.Len()
+	}
+	return size
+}
+
+func (s setEncoder) Encode(dst []byte) {
+	// Per X690 Section 11.6: The encodings of the component values of a
+	// set-of value shall appear in ascending order, the encodings being
+	// compared as octet strings with the shorter components being padded
+	// at their trailing end with 0-octets.
+	//
+	// First we encode each element to its TLV encoding and then use
+	// octetSort to get the ordering expected by X690 DER rules before
+	// writing the sorted encodings out to dst.
+	l := make([][]byte, len(s))
+	for i, e := range s {
+		l[i] = make([]byte, e.Len())
+		e.Encode(l[i])
+	}
+
+	sort.Slice(l, func(i, j int) bool {
+		// Since we are using bytes.Compare to compare TLV encodings we
+		// don't need to right pad s[i] and s[j] to the same length as
+		// suggested in X690. If len(s[i]) < len(s[j]) the length octet of
+		// s[i], which is the first determining byte, will inherently be
+		// smaller than the length octet of s[j]. This lets us skip the
+		// padding step.
+		return bytes.Compare(l[i], l[j]) < 0
+	})
+
+	var off int
+	for _, b := range l {
+		copy(dst[off:], b)
+		off += len(b)
+	}
+}
+
 type taggedEncoder struct {
 	// scratch contains temporary space for encoding the tag and length of
 	// an element in order to avoid extra allocations.
@@ -511,6 +555,9 @@ func makeBody(value reflect.Value, params fieldParameters) (e encoder, err error
 				}
 			}
 
+			if params.set {
+				return setEncoder(m), nil
+			}
 			return multiEncoder(m), nil
 		}
 	case reflect.String:
@@ -618,6 +665,15 @@ func makeField(v reflect.Value, params fieldParameters) (e encoder, err error) {
 		tag = TagSet
 	}
 
+	// makeField can be called for a slice that should be treated as a SET
+	// but doesn't have params.set set, for instance when using a slice
+	// with the SET type name suffix. In this case getUniversalType returns
+	// TagSet, but makeBody doesn't know about that so will treat the slice
+	// as a sequence. To work around this we set params.set.
+	if tag == TagSet && !params.set {
+		params.set = true
+	}
+
 	t := new(taggedEncoder)
 
 	t.body, err = makeBody(v, params)
diff --git a/libgo/go/encoding/asn1/marshal_test.go b/libgo/go/encoding/asn1/marshal_test.go
index a77826a..5290522 100644
--- a/libgo/go/encoding/asn1/marshal_test.go
+++ b/libgo/go/encoding/asn1/marshal_test.go
@@ -319,3 +319,60 @@ func BenchmarkMarshal(b *testing.B) {
 		}
 	}
 }
+
+func TestSetEncoder(t *testing.T) {
+	testStruct := struct {
+		Strings []string `asn1:"set"`
+	}{
+		Strings: []string{"a", "aa", "b", "bb", "c", "cc"},
+	}
+
+	// Expected ordering of the SET should be:
+	// a, b, c, aa, bb, cc
+
+	output, err := Marshal(testStruct)
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+
+	expectedOrder := []string{"a", "b", "c", "aa", "bb", "cc"}
+	var resultStruct struct {
+		Strings []string `asn1:"set"`
+	}
+	rest, err := Unmarshal(output, &resultStruct)
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	if len(rest) != 0 {
+		t.Error("Unmarshal returned extra garbage")
+	}
+	if !reflect.DeepEqual(expectedOrder, resultStruct.Strings) {
+		t.Errorf("Unexpected SET content. got: %s, want: %s", resultStruct.Strings, expectedOrder)
+	}
+}
+
+func TestSetEncoderSETSliceSuffix(t *testing.T) {
+	type testSetSET []string
+	testSet := testSetSET{"a", "aa", "b", "bb", "c", "cc"}
+
+	// Expected ordering of the SET should be:
+	// a, b, c, aa, bb, cc
+
+	output, err := Marshal(testSet)
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+
+	expectedOrder := testSetSET{"a", "b", "c", "aa", "bb", "cc"}
+	var resultSet testSetSET
+	rest, err := Unmarshal(output, &resultSet)
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	if len(rest) != 0 {
+		t.Error("Unmarshal returned extra garbage")
+	}
+	if !reflect.DeepEqual(expectedOrder, resultSet) {
+		t.Errorf("Unexpected SET content. got: %s, want: %s", resultSet, expectedOrder)
+	}
+}
diff --git a/libgo/go/encoding/base64/base64.go b/libgo/go/encoding/base64/base64.go
index 690d3ce..0c33f8e 100644
--- a/libgo/go/encoding/base64/base64.go
+++ b/libgo/go/encoding/base64/base64.go
@@ -480,15 +480,16 @@ func (enc *Encoding) Decode(dst, src []byte) (n int, err error) {
 
 	si := 0
 	for strconv.IntSize >= 64 && len(src)-si >= 8 && len(dst)-n >= 8 {
+		src2 := src[si : si+8]
 		if dn, ok := assemble64(
-			enc.decodeMap[src[si+0]],
-			enc.decodeMap[src[si+1]],
-			enc.decodeMap[src[si+2]],
-			enc.decodeMap[src[si+3]],
-			enc.decodeMap[src[si+4]],
-			enc.decodeMap[src[si+5]],
-			enc.decodeMap[src[si+6]],
-			enc.decodeMap[src[si+7]],
+			enc.decodeMap[src2[0]],
+			enc.decodeMap[src2[1]],
+			enc.decodeMap[src2[2]],
+			enc.decodeMap[src2[3]],
+			enc.decodeMap[src2[4]],
+			enc.decodeMap[src2[5]],
+			enc.decodeMap[src2[6]],
+			enc.decodeMap[src2[7]],
 		); ok {
 			binary.BigEndian.PutUint64(dst[n:], dn)
 			n += 6
@@ -504,11 +505,12 @@ func (enc *Encoding) Decode(dst, src []byte) (n int, err error) {
 	}
 
 	for len(src)-si >= 4 && len(dst)-n >= 4 {
+		src2 := src[si : si+4]
 		if dn, ok := assemble32(
-			enc.decodeMap[src[si+0]],
-			enc.decodeMap[src[si+1]],
-			enc.decodeMap[src[si+2]],
-			enc.decodeMap[src[si+3]],
+			enc.decodeMap[src2[0]],
+			enc.decodeMap[src2[1]],
+			enc.decodeMap[src2[2]],
+			enc.decodeMap[src2[3]],
 		); ok {
 			binary.BigEndian.PutUint32(dst[n:], dn)
 			n += 3
diff --git a/libgo/go/encoding/base64/base64_test.go b/libgo/go/encoding/base64/base64_test.go
index bc67036..c2c9478 100644
--- a/libgo/go/encoding/base64/base64_test.go
+++ b/libgo/go/encoding/base64/base64_test.go
@@ -401,7 +401,7 @@ func TestDecoderIssue3577(t *testing.T) {
 		source: "VHdhcyBicmlsbGlnLCBhbmQgdGhlIHNsaXRoeSB0b3Zlcw==", // twas brillig...
 		nextc:  next,
 	})
-	errc := make(chan error)
+	errc := make(chan error, 1)
 	go func() {
 		_, err := ioutil.ReadAll(d)
 		errc <- err
diff --git a/libgo/go/encoding/csv/writer.go b/libgo/go/encoding/csv/writer.go
index 3f34bc5..ac64b4d 100644
--- a/libgo/go/encoding/csv/writer.go
+++ b/libgo/go/encoding/csv/writer.go
@@ -158,10 +158,24 @@ func (w *Writer) fieldNeedsQuotes(field string) bool {
 	if field == "" {
 		return false
 	}
-	if field == `\.` || strings.ContainsRune(field, w.Comma) || strings.ContainsAny(field, "\"\r\n") {
+
+	if field == `\.` {
 		return true
 	}
 
+	if w.Comma < utf8.RuneSelf {
+		for i := 0; i < len(field); i++ {
+			c := field[i]
+			if c == '\n' || c == '\r' || c == '"' || c == byte(w.Comma) {
+				return true
+			}
+		}
+	} else {
+		if strings.ContainsRune(field, w.Comma) || strings.ContainsAny(field, "\"\r\n") {
+			return true
+		}
+	}
+
 	r1, _ := utf8.DecodeRuneInString(field)
 	return unicode.IsSpace(r1)
 }
diff --git a/libgo/go/encoding/csv/writer_test.go b/libgo/go/encoding/csv/writer_test.go
index 011f01c..ab28b0d7 100644
--- a/libgo/go/encoding/csv/writer_test.go
+++ b/libgo/go/encoding/csv/writer_test.go
@@ -93,3 +93,20 @@ func TestError(t *testing.T) {
 		t.Error("Error should not be nil")
 	}
 }
+
+var benchmarkWriteData = [][]string{
+	{"abc", "def", "12356", "1234567890987654311234432141542132"},
+	{"abc", "def", "12356", "1234567890987654311234432141542132"},
+	{"abc", "def", "12356", "1234567890987654311234432141542132"},
+}
+
+func BenchmarkWrite(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		w := NewWriter(&bytes.Buffer{})
+		err := w.WriteAll(benchmarkWriteData)
+		if err != nil {
+			b.Fatal(err)
+		}
+		w.Flush()
+	}
+}
diff --git a/libgo/go/encoding/hex/hex_test.go b/libgo/go/encoding/hex/hex_test.go
index dbb00b9..31e3f68 100644
--- a/libgo/go/encoding/hex/hex_test.go
+++ b/libgo/go/encoding/hex/hex_test.go
@@ -267,7 +267,6 @@ func BenchmarkDecode(b *testing.B) {
 func BenchmarkDump(b *testing.B) {
 	for _, size := range []int{256, 1024, 4096, 16384} {
 		src := bytes.Repeat([]byte{2, 3, 5, 7, 9, 11, 13, 17}, size/8)
-		sink = make([]byte, 2*size)
 
 		b.Run(fmt.Sprintf("%v", size), func(b *testing.B) {
 			b.SetBytes(int64(size))
diff --git a/libgo/go/encoding/json/decode_test.go b/libgo/go/encoding/json/decode_test.go
index 689cc34..219e845 100644
--- a/libgo/go/encoding/json/decode_test.go
+++ b/libgo/go/encoding/json/decode_test.go
@@ -2476,3 +2476,99 @@ func TestUnmarshalRescanLiteralMangledUnquote(t *testing.T) {
 		t.Fatalf("Unexpected roundtrip result:\nwant: %q\ngot:  %q", want, got)
 	}
 }
+
+func TestUnmarshalMaxDepth(t *testing.T) {
+	testcases := []struct {
+		name        string
+		data        string
+		errMaxDepth bool
+	}{
+		{
+			name:        "ArrayUnderMaxNestingDepth",
+			data:        `{"a":` + strings.Repeat(`[`, 10000-1) + strings.Repeat(`]`, 10000-1) + `}`,
+			errMaxDepth: false,
+		},
+		{
+			name:        "ArrayOverMaxNestingDepth",
+			data:        `{"a":` + strings.Repeat(`[`, 10000) + strings.Repeat(`]`, 10000) + `}`,
+			errMaxDepth: true,
+		},
+		{
+			name:        "ArrayOverStackDepth",
+			data:        `{"a":` + strings.Repeat(`[`, 3000000) + strings.Repeat(`]`, 3000000) + `}`,
+			errMaxDepth: true,
+		},
+		{
+			name:        "ObjectUnderMaxNestingDepth",
+			data:        `{"a":` + strings.Repeat(`{"a":`, 10000-1) + `0` + strings.Repeat(`}`, 10000-1) + `}`,
+			errMaxDepth: false,
+		},
+		{
+			name:        "ObjectOverMaxNestingDepth",
+			data:        `{"a":` + strings.Repeat(`{"a":`, 10000) + `0` + strings.Repeat(`}`, 10000) + `}`,
+			errMaxDepth: true,
+		},
+		{
+			name:        "ObjectOverStackDepth",
+			data:        `{"a":` + strings.Repeat(`{"a":`, 3000000) + `0` + strings.Repeat(`}`, 3000000) + `}`,
+			errMaxDepth: true,
+		},
+	}
+
+	targets := []struct {
+		name     string
+		newValue func() interface{}
+	}{
+		{
+			name: "unstructured",
+			newValue: func() interface{} {
+				var v interface{}
+				return &v
+			},
+		},
+		{
+			name: "typed named field",
+			newValue: func() interface{} {
+				v := struct {
+					A interface{} `json:"a"`
+				}{}
+				return &v
+			},
+		},
+		{
+			name: "typed missing field",
+			newValue: func() interface{} {
+				v := struct {
+					B interface{} `json:"b"`
+				}{}
+				return &v
+			},
+		},
+		{
+			name: "custom unmarshaler",
+			newValue: func() interface{} {
+				v := unmarshaler{}
+				return &v
+			},
+		},
+	}
+
+	for _, tc := range testcases {
+		for _, target := range targets {
+			t.Run(target.name+"-"+tc.name, func(t *testing.T) {
+				err := Unmarshal([]byte(tc.data), target.newValue())
+				if !tc.errMaxDepth {
+					if err != nil {
+						t.Errorf("unexpected error: %v", err)
+					}
+				} else {
+					if err == nil {
+						t.Errorf("expected error containing 'exceeded max depth', got none")
+					} else if !strings.Contains(err.Error(), "exceeded max depth") {
+						t.Errorf("expected error containing 'exceeded max depth', got: %v", err)
+					}
+				}
+			})
+		}
+	}
+}
diff --git a/libgo/go/encoding/json/encode.go b/libgo/go/encoding/json/encode.go
index b351cf3..578d551 100644
--- a/libgo/go/encoding/json/encode.go
+++ b/libgo/go/encoding/json/encode.go
@@ -650,7 +650,7 @@ func stringEncoder(e *encodeState, v reflect.Value, opts encOpts) {
 func isValidNumber(s string) bool {
 	// This function implements the JSON numbers grammar.
 	// See https://tools.ietf.org/html/rfc7159#section-6
-	// and https://json.org/number.gif
+	// and https://www.json.org/img/number.png
 
 	if s == "" {
 		return false
diff --git a/libgo/go/encoding/json/scanner.go b/libgo/go/encoding/json/scanner.go
index 552bd70..9dc1903 100644
--- a/libgo/go/encoding/json/scanner.go
+++ b/libgo/go/encoding/json/scanner.go
@@ -139,6 +139,10 @@ const (
 	parseArrayValue         // parsing array value
 )
 
+// This limits the max nesting depth to prevent stack overflow.
+// This is permitted by https://tools.ietf.org/html/rfc7159#section-9
+const maxNestingDepth = 10000
+
 // reset prepares the scanner for use.
 // It must be called before calling s.step.
 func (s *scanner) reset() {
@@ -168,8 +172,13 @@ func (s *scanner) eof() int {
 }
 
 // pushParseState pushes a new parse state p onto the parse stack.
-func (s *scanner) pushParseState(p int) {
-	s.parseState = append(s.parseState, p)
+// an error state is returned if maxNestingDepth was exceeded, otherwise successState is returned.
+func (s *scanner) pushParseState(c byte, newParseState int, successState int) int {
+	s.parseState = append(s.parseState, newParseState)
+	if len(s.parseState) <= maxNestingDepth {
+		return successState
+	}
+	return s.error(c, "exceeded max depth")
 }
 
 // popParseState pops a parse state (already obtained) off the stack
@@ -186,12 +195,12 @@ func (s *scanner) popParseState() {
 }
 
 func isSpace(c byte) bool {
-	return c == ' ' || c == '\t' || c == '\r' || c == '\n'
+	return c <= ' ' && (c == ' ' || c == '\t' || c == '\r' || c == '\n')
 }
 
 // stateBeginValueOrEmpty is the state after reading `[`.
 func stateBeginValueOrEmpty(s *scanner, c byte) int {
-	if c <= ' ' && isSpace(c) {
+	if isSpace(c) {
 		return scanSkipSpace
 	}
 	if c == ']' {
@@ -202,18 +211,16 @@ func stateBeginValueOrEmpty(s *scanner, c byte) int {
 
 // stateBeginValue is the state at the beginning of the input.
 func stateBeginValue(s *scanner, c byte) int {
-	if c <= ' ' && isSpace(c) {
+	if isSpace(c) {
 		return scanSkipSpace
 	}
 	switch c {
 	case '{':
 		s.step = stateBeginStringOrEmpty
-		s.pushParseState(parseObjectKey)
-		return scanBeginObject
+		return s.pushParseState(c, parseObjectKey, scanBeginObject)
 	case '[':
 		s.step = stateBeginValueOrEmpty
-		s.pushParseState(parseArrayValue)
-		return scanBeginArray
+		return s.pushParseState(c, parseArrayValue, scanBeginArray)
 	case '"':
 		s.step = stateInString
 		return scanBeginLiteral
@@ -242,7 +249,7 @@ func stateBeginValue(s *scanner, c byte) int {
 
 // stateBeginStringOrEmpty is the state after reading `{`.
 func stateBeginStringOrEmpty(s *scanner, c byte) int {
-	if c <= ' ' && isSpace(c) {
+	if isSpace(c) {
 		return scanSkipSpace
 	}
 	if c == '}' {
@@ -255,7 +262,7 @@ func stateBeginStringOrEmpty(s *scanner, c byte) int {
 
 // stateBeginString is the state after reading `{"key": value,`.
 func stateBeginString(s *scanner, c byte) int {
-	if c <= ' ' && isSpace(c) {
+	if isSpace(c) {
 		return scanSkipSpace
 	}
 	if c == '"' {
@@ -275,7 +282,7 @@ func stateEndValue(s *scanner, c byte) int {
 		s.endTop = true
 		return stateEndTop(s, c)
 	}
-	if c <= ' ' && isSpace(c) {
+	if isSpace(c) {
 		s.step = stateEndValue
 		return scanSkipSpace
 	}
diff --git a/libgo/go/encoding/xml/marshal.go b/libgo/go/encoding/xml/marshal.go
index e325f31..0554b0d 100644
--- a/libgo/go/encoding/xml/marshal.go
+++ b/libgo/go/encoding/xml/marshal.go
@@ -479,8 +479,11 @@ func (p *printer) marshalValue(val reflect.Value, finfo *fieldInfo, startTemplat
 		xmlname := tinfo.xmlname
 		if xmlname.name != "" {
 			start.Name.Space, start.Name.Local = xmlname.xmlns, xmlname.name
-		} else if v, ok := xmlname.value(val).Interface().(Name); ok && v.Local != "" {
-			start.Name = v
+		} else {
+			fv := xmlname.value(val, dontInitNilPointers)
+			if v, ok := fv.Interface().(Name); ok && v.Local != "" {
+				start.Name = v
+			}
 		}
 	}
 	if start.Name.Local == "" && finfo != nil {
@@ -500,7 +503,7 @@ func (p *printer) marshalValue(val reflect.Value, finfo *fieldInfo, startTemplat
 		if finfo.flags&fAttr == 0 {
 			continue
 		}
-		fv := finfo.value(val)
+		fv := finfo.value(val, dontInitNilPointers)
 
 		if finfo.flags&fOmitEmpty != 0 && isEmptyValue(fv) {
 			continue
@@ -803,7 +806,12 @@ func (p *printer) marshalStruct(tinfo *typeInfo, val reflect.Value) error {
 		if finfo.flags&fAttr != 0 {
 			continue
 		}
-		vf := finfo.value(val)
+		vf := finfo.value(val, dontInitNilPointers)
+		if !vf.IsValid() {
+			// The field is behind an anonymous struct field that's
+			// nil. Skip it.
+			continue
+		}
 
 		switch finfo.flags & fMode {
 		case fCDATA, fCharData:
diff --git a/libgo/go/encoding/xml/marshal_test.go b/libgo/go/encoding/xml/marshal_test.go
index 8473158b..31309ef 100644
--- a/libgo/go/encoding/xml/marshal_test.go
+++ b/libgo/go/encoding/xml/marshal_test.go
@@ -309,6 +309,11 @@ type ChardataEmptyTest struct {
 	Contents *string `xml:",chardata"`
 }
 
+type PointerAnonFields struct {
+	*MyInt
+	*NamedType
+}
+
 type MyMarshalerTest struct {
 }
 
@@ -889,6 +894,18 @@ var marshalTests = []struct {
 			`</EmbedA>`,
 	},
 
+	// Anonymous struct pointer field which is nil
+	{
+		Value:     &EmbedB{},
+		ExpectXML: `<EmbedB><FieldB></FieldB></EmbedB>`,
+	},
+
+	// Other kinds of nil anonymous fields
+	{
+		Value:     &PointerAnonFields{},
+		ExpectXML: `<PointerAnonFields></PointerAnonFields>`,
+	},
+
 	// Test that name casing matters
 	{
 		Value:     &NameCasing{Xy: "mixed", XY: "upper", XyA: "mixedA", XYA: "upperA"},
diff --git a/libgo/go/encoding/xml/read.go b/libgo/go/encoding/xml/read.go
index 10a60ee..ef5df3f 100644
--- a/libgo/go/encoding/xml/read.go
+++ b/libgo/go/encoding/xml/read.go
@@ -435,7 +435,7 @@ func (d *Decoder) unmarshal(val reflect.Value, start *StartElement) error {
 				}
 				return UnmarshalError(e)
 			}
-			fv := finfo.value(sv)
+			fv := finfo.value(sv, initNilPointers)
 			if _, ok := fv.Interface().(Name); ok {
 				fv.Set(reflect.ValueOf(start.Name))
 			}
@@ -449,7 +449,7 @@ func (d *Decoder) unmarshal(val reflect.Value, start *StartElement) error {
 				finfo := &tinfo.fields[i]
 				switch finfo.flags & fMode {
 				case fAttr:
-					strv := finfo.value(sv)
+					strv := finfo.value(sv, initNilPointers)
 					if a.Name.Local == finfo.name && (finfo.xmlns == "" || finfo.xmlns == a.Name.Space) {
 						if err := d.unmarshalAttr(strv, a); err != nil {
 							return err
@@ -465,7 +465,7 @@ func (d *Decoder) unmarshal(val reflect.Value, start *StartElement) error {
 			}
 			if !handled && any >= 0 {
 				finfo := &tinfo.fields[any]
-				strv := finfo.value(sv)
+				strv := finfo.value(sv, initNilPointers)
 				if err := d.unmarshalAttr(strv, a); err != nil {
 					return err
 				}
@@ -478,22 +478,22 @@ func (d *Decoder) unmarshal(val reflect.Value, start *StartElement) error {
 			switch finfo.flags & fMode {
 			case fCDATA, fCharData:
 				if !saveData.IsValid() {
-					saveData = finfo.value(sv)
+					saveData = finfo.value(sv, initNilPointers)
 				}
 
 			case fComment:
 				if !saveComment.IsValid() {
-					saveComment = finfo.value(sv)
+					saveComment = finfo.value(sv, initNilPointers)
 				}
 
 			case fAny, fAny | fElement:
 				if !saveAny.IsValid() {
-					saveAny = finfo.value(sv)
+					saveAny = finfo.value(sv, initNilPointers)
 				}
 
 			case fInnerXML:
 				if !saveXML.IsValid() {
-					saveXML = finfo.value(sv)
+					saveXML = finfo.value(sv, initNilPointers)
 					if d.saved == nil {
 						saveXMLIndex = 0
 						d.saved = new(bytes.Buffer)
@@ -687,7 +687,7 @@ Loop:
 		}
 		if len(finfo.parents) == len(parents) && finfo.name == start.Name.Local {
 			// It's a perfect match, unmarshal the field.
-			return true, d.unmarshal(finfo.value(sv), start)
+			return true, d.unmarshal(finfo.value(sv, initNilPointers), start)
 		}
 		if len(finfo.parents) > len(parents) && finfo.parents[len(parents)] == start.Name.Local {
 			// It's a prefix for the field. Break and recurse
diff --git a/libgo/go/encoding/xml/typeinfo.go b/libgo/go/encoding/xml/typeinfo.go
index 639952c..f30fe58 100644
--- a/libgo/go/encoding/xml/typeinfo.go
+++ b/libgo/go/encoding/xml/typeinfo.go
@@ -344,15 +344,25 @@ func (e *TagPathError) Error() string {
 	return fmt.Sprintf("%s field %q with tag %q conflicts with field %q with tag %q", e.Struct, e.Field1, e.Tag1, e.Field2, e.Tag2)
 }
 
+const (
+	initNilPointers     = true
+	dontInitNilPointers = false
+)
+
 // value returns v's field value corresponding to finfo.
-// It's equivalent to v.FieldByIndex(finfo.idx), but initializes
-// and dereferences pointers as necessary.
-func (finfo *fieldInfo) value(v reflect.Value) reflect.Value {
+// It's equivalent to v.FieldByIndex(finfo.idx), but when passed
+// initNilPointers, it initializes and dereferences pointers as necessary.
+// When passed dontInitNilPointers and a nil pointer is reached, the function
+// returns a zero reflect.Value.
+func (finfo *fieldInfo) value(v reflect.Value, shouldInitNilPointers bool) reflect.Value {
 	for i, x := range finfo.idx {
 		if i > 0 {
 			t := v.Type()
 			if t.Kind() == reflect.Ptr && t.Elem().Kind() == reflect.Struct {
 				if v.IsNil() {
+					if !shouldInitNilPointers {
+						return reflect.Value{}
+					}
 					v.Set(reflect.New(v.Type().Elem()))
 				}
 				v = v.Elem()
diff --git a/libgo/go/encoding/xml/xml.go b/libgo/go/encoding/xml/xml.go
index 5e73dcf..adaf4da 100644
--- a/libgo/go/encoding/xml/xml.go
+++ b/libgo/go/encoding/xml/xml.go
@@ -960,7 +960,7 @@ func (d *Decoder) ungetc(b byte) {
 	d.offset--
 }
 
-var entity = map[string]int{
+var entity = map[string]rune{
 	"lt":   '<',
 	"gt":   '>',
 	"amp":  '&',
@@ -1055,7 +1055,7 @@ Input:
 					d.buf.WriteByte(';')
 					n, err := strconv.ParseUint(s, base, 64)
 					if err == nil && n <= unicode.MaxRune {
-						text = string(n)
+						text = string(rune(n))
 						haveText = true
 					}
 				}