Imported Upstream version 1.1~hg20130323upstream/1.1_hg20130323

21 files changed, 693 insertions, 124 deletions

diff --git a/src/pkg/encoding/ascii85/ascii85.go b/src/pkg/encoding/ascii85/ascii85.go
index 705022792..e2afc5871 100644
--- a/src/pkg/encoding/ascii85/ascii85.go
+++ b/src/pkg/encoding/ascii85/ascii85.go
@@ -296,5 +296,4 @@ func (d *decoder) Read(p []byte) (n int, err error) {
 		nn, d.readErr = d.r.Read(d.buf[d.nbuf:])
 		d.nbuf += nn
 	}
-	panic("unreachable")
 }
diff --git a/src/pkg/encoding/asn1/marshal.go b/src/pkg/encoding/asn1/marshal.go
index 0c216fdb3..adaf80dcd 100644
--- a/src/pkg/encoding/asn1/marshal.go
+++ b/src/pkg/encoding/asn1/marshal.go
@@ -460,7 +460,6 @@ func marshalBody(out *forkableWriter, value reflect.Value, params fieldParameter
 		default:
 			return marshalUTF8String(out, v.String())
 		}
-		return
 	}
 
 	return StructuralError{"unknown Go type"}
diff --git a/src/pkg/encoding/base32/base32.go b/src/pkg/encoding/base32/base32.go
index dbefc48fa..fe17b7322 100644
--- a/src/pkg/encoding/base32/base32.go
+++ b/src/pkg/encoding/base32/base32.go
@@ -6,8 +6,10 @@
 package base32
 
 import (
+	"bytes"
 	"io"
 	"strconv"
+	"strings"
 )
 
 /*
@@ -48,6 +50,13 @@ var StdEncoding = NewEncoding(encodeStd)
 // It is typically used in DNS.
 var HexEncoding = NewEncoding(encodeHex)
 
+var removeNewlinesMapper = func(r rune) rune {
+	if r == '\r' || r == '\n' {
+		return -1
+	}
+	return r
+}
+
 /*
  * Encoder
  */
@@ -228,40 +237,47 @@ func (e CorruptInputError) Error() string {
 
 // decode is like Decode but returns an additional 'end' value, which
 // indicates if end-of-message padding was encountered and thus any
-// additional data is an error.
+// additional data is an error. This method assumes that src has been
+// stripped of all supported whitespace ('\r' and '\n').
 func (enc *Encoding) decode(dst, src []byte) (n int, end bool, err error) {
-	osrc := src
+	olen := len(src)
 	for len(src) > 0 && !end {
 		// Decode quantum using the base32 alphabet
 		var dbuf [8]byte
 		dlen := 8
 
-		// do the top bytes contain any data?
 		for j := 0; j < 8; {
 			if len(src) == 0 {
-				return n, false, CorruptInputError(len(osrc) - len(src) - j)
+				return n, false, CorruptInputError(olen - len(src) - j)
 			}
 			in := src[0]
 			src = src[1:]
-			if in == '\r' || in == '\n' {
-				// Ignore this character.
-				continue
-			}
 			if in == '=' && j >= 2 && len(src) < 8 {
-				// We've reached the end and there's
-				// padding, the rest should be padded
-				for k := 0; k < 8-j-1; k++ {
+				// We've reached the end and there's padding
+				if len(src)+j < 8-1 {
+					// not enough padding
+					return n, false, CorruptInputError(olen)
+				}
+				for k := 0; k < 8-1-j; k++ {
 					if len(src) > k && src[k] != '=' {
-						return n, false, CorruptInputError(len(osrc) - len(src) + k - 1)
+						// incorrect padding
+						return n, false, CorruptInputError(olen - len(src) + k - 1)
 					}
 				}
-				dlen = j
-				end = true
+				dlen, end = j, true
+				// 7, 5 and 2 are not valid padding lengths, and so 1, 3 and 6 are not
+				// valid dlen values. See RFC 4648 Section 6 "Base 32 Encoding" listing
+				// the five valid padding lengths, and Section 9 "Illustrations and
+				// Examples" for an illustration for how the the 1st, 3rd and 6th base32
+				// src bytes do not yield enough information to decode a dst byte.
+				if dlen == 1 || dlen == 3 || dlen == 6 {
+					return n, false, CorruptInputError(olen - len(src) - 1)
+				}
 				break
 			}
 			dbuf[j] = enc.decodeMap[in]
 			if dbuf[j] == 0xFF {
-				return n, false, CorruptInputError(len(osrc) - len(src) - 1)
+				return n, false, CorruptInputError(olen - len(src) - 1)
 			}
 			j++
 		}
@@ -269,16 +285,16 @@ func (enc *Encoding) decode(dst, src []byte) (n int, end bool, err error) {
 		// Pack 8x 5-bit source blocks into 5 byte destination
 		// quantum
 		switch dlen {
-		case 7, 8:
+		case 8:
 			dst[4] = dbuf[6]<<5 | dbuf[7]
 			fallthrough
-		case 6, 5:
+		case 7:
 			dst[3] = dbuf[4]<<7 | dbuf[5]<<2 | dbuf[6]>>3
 			fallthrough
-		case 4:
+		case 5:
 			dst[2] = dbuf[3]<<4 | dbuf[4]>>1
 			fallthrough
-		case 3:
+		case 4:
 			dst[1] = dbuf[1]<<6 | dbuf[2]<<1 | dbuf[3]>>4
 			fallthrough
 		case 2:
@@ -288,11 +304,11 @@ func (enc *Encoding) decode(dst, src []byte) (n int, end bool, err error) {
 		switch dlen {
 		case 2:
 			n += 1
-		case 3, 4:
+		case 4:
 			n += 2
 		case 5:
 			n += 3
-		case 6, 7:
+		case 7:
 			n += 4
 		case 8:
 			n += 5
@@ -307,12 +323,14 @@ func (enc *Encoding) decode(dst, src []byte) (n int, end bool, err error) {
 // number of bytes successfully written and CorruptInputError.
 // New line characters (\r and \n) are ignored.
 func (enc *Encoding) Decode(dst, src []byte) (n int, err error) {
+	src = bytes.Map(removeNewlinesMapper, src)
 	n, _, err = enc.decode(dst, src)
 	return
 }
 
 // DecodeString returns the bytes represented by the base32 string s.
 func (enc *Encoding) DecodeString(s string) ([]byte, error) {
+	s = strings.Map(removeNewlinesMapper, s)
 	dbuf := make([]byte, enc.DecodedLen(len(s)))
 	n, err := enc.Decode(dbuf, []byte(s))
 	return dbuf[:n], err
@@ -377,9 +395,34 @@ func (d *decoder) Read(p []byte) (n int, err error) {
 	return n, d.err
 }
 
+type newlineFilteringReader struct {
+	wrapped io.Reader
+}
+
+func (r *newlineFilteringReader) Read(p []byte) (int, error) {
+	n, err := r.wrapped.Read(p)
+	for n > 0 {
+		offset := 0
+		for i, b := range p[0:n] {
+			if b != '\r' && b != '\n' {
+				if i != offset {
+					p[offset] = b
+				}
+				offset++
+			}
+		}
+		if offset > 0 {
+			return offset, err
+		}
+		// Previous buffer entirely whitespace, read again
+		n, err = r.wrapped.Read(p)
+	}
+	return n, err
+}
+
 // NewDecoder constructs a new base32 stream decoder.
 func NewDecoder(enc *Encoding, r io.Reader) io.Reader {
-	return &decoder{enc: enc, r: r}
+	return &decoder{enc: enc, r: &newlineFilteringReader{r}}
 }
 
 // DecodedLen returns the maximum length in bytes of the decoded data
diff --git a/src/pkg/encoding/base32/base32_test.go b/src/pkg/encoding/base32/base32_test.go
index 98365e18c..63298d1c9 100644
--- a/src/pkg/encoding/base32/base32_test.go
+++ b/src/pkg/encoding/base32/base32_test.go
@@ -8,6 +8,7 @@ import (
 	"bytes"
 	"io"
 	"io/ioutil"
+	"strings"
 	"testing"
 )
 
@@ -137,27 +138,48 @@ func TestDecoderBuffering(t *testing.T) {
 }
 
 func TestDecodeCorrupt(t *testing.T) {
-	type corrupt struct {
-		e string
-		p int
-	}
-	examples := []corrupt{
+	testCases := []struct {
+		input  string
+		offset int // -1 means no corruption.
+	}{
+		{"", -1},
 		{"!!!!", 0},
 		{"x===", 0},
 		{"AA=A====", 2},
 		{"AAA=AAAA", 3},
 		{"MMMMMMMMM", 8},
 		{"MMMMMM", 0},
+		{"A=", 1},
+		{"AA=", 3},
+		{"AA==", 4},
+		{"AA===", 5},
+		{"AAAA=", 5},
+		{"AAAA==", 6},
+		{"AAAAA=", 6},
+		{"AAAAA==", 7},
+		{"A=======", 1},
+		{"AA======", -1},
+		{"AAA=====", 3},
+		{"AAAA====", -1},
+		{"AAAAA===", -1},
+		{"AAAAAA==", 6},
+		{"AAAAAAA=", -1},
+		{"AAAAAAAA", -1},
 	}
-
-	for _, e := range examples {
-		dbuf := make([]byte, StdEncoding.DecodedLen(len(e.e)))
-		_, err := StdEncoding.Decode(dbuf, []byte(e.e))
+	for _, tc := range testCases {
+		dbuf := make([]byte, StdEncoding.DecodedLen(len(tc.input)))
+		_, err := StdEncoding.Decode(dbuf, []byte(tc.input))
+		if tc.offset == -1 {
+			if err != nil {
+				t.Error("Decoder wrongly detected coruption in", tc.input)
+			}
+			continue
+		}
 		switch err := err.(type) {
 		case CorruptInputError:
-			testEqual(t, "Corruption in %q at offset %v, want %v", e.e, int(err), e.p)
+			testEqual(t, "Corruption in %q at offset %v, want %v", tc.input, int(err), tc.offset)
 		default:
-			t.Error("Decoder failed to detect corruption in", e)
+			t.Error("Decoder failed to detect corruption in", tc)
 		}
 	}
 }
@@ -195,9 +217,21 @@ func TestBig(t *testing.T) {
 	}
 }
 
+func testStringEncoding(t *testing.T, expected string, examples []string) {
+	for _, e := range examples {
+		buf, err := StdEncoding.DecodeString(e)
+		if err != nil {
+			t.Errorf("Decode(%q) failed: %v", e, err)
+			continue
+		}
+		if s := string(buf); s != expected {
+			t.Errorf("Decode(%q) = %q, want %q", e, s, expected)
+		}
+	}
+}
+
 func TestNewLineCharacters(t *testing.T) {
 	// Each of these should decode to the string "sure", without errors.
-	const expected = "sure"
 	examples := []string{
 		"ON2XEZI=",
 		"ON2XEZI=\r",
@@ -209,14 +243,44 @@ func TestNewLineCharacters(t *testing.T) {
 		"ON2XEZ\nI=",
 		"ON2XEZI\n=",
 	}
-	for _, e := range examples {
-		buf, err := StdEncoding.DecodeString(e)
-		if err != nil {
-			t.Errorf("Decode(%q) failed: %v", e, err)
-			continue
-		}
-		if s := string(buf); s != expected {
-			t.Errorf("Decode(%q) = %q, want %q", e, s, expected)
-		}
+	testStringEncoding(t, "sure", examples)
+
+	// Each of these should decode to the string "foobar", without errors.
+	examples = []string{
+		"MZXW6YTBOI======",
+		"MZXW6YTBOI=\r\n=====",
+	}
+	testStringEncoding(t, "foobar", examples)
+}
+
+func TestDecoderIssue4779(t *testing.T) {
+	encoded := `JRXXEZLNEBUXA43VNUQGI33MN5ZCA43JOQQGC3LFOQWCAY3PNZZWKY3UMV2HK4
+RAMFSGS4DJONUWG2LOM4QGK3DJOQWCA43FMQQGI3YKMVUXK43NN5SCA5DFNVYG64RANFXGG2LENFSH
+K3TUEB2XIIDMMFRG64TFEBSXIIDEN5WG64TFEBWWCZ3OMEQGC3DJOF2WCLRAKV2CAZLONFWQUYLEEB
+WWS3TJNUQHMZLONFQW2LBAOF2WS4ZANZXXG5DSOVSCAZLYMVZGG2LUMF2GS33OEB2WY3DBNVRW6IDM
+MFRG64TJOMQG42LTNEQHK5AKMFWGS4LVNFYCAZLYEBSWCIDDN5WW233EN4QGG33OONSXC5LBOQXCAR
+DVNFZSAYLVORSSA2LSOVZGKIDEN5WG64RANFXAU4TFOBZGK2DFNZSGK4TJOQQGS3RAOZXWY5LQORQX
+IZJAOZSWY2LUEBSXG43FEBRWS3DMOVWSAZDPNRXXEZJAMV2SAZTVM5UWC5BANZ2WY3DBBJYGC4TJMF
+2HK4ROEBCXQY3FOB2GK5LSEBZWS3TUEBXWGY3BMVRWC5BAMN2XA2LEMF2GC5BANZXW4IDQOJXWSZDF
+NZ2CYIDTOVXHIIDJNYFGG5LMOBQSA4LVNEQG6ZTGNFRWSYJAMRSXGZLSOVXHIIDNN5WGY2LUEBQW42
+LNEBUWIIDFON2CA3DBMJXXE5LNFY==
+====`
+	encodedShort := strings.Replace(encoded, "\n", "", -1)
+
+	dec := NewDecoder(StdEncoding, bytes.NewBufferString(encoded))
+	res1, err := ioutil.ReadAll(dec)
+	if err != nil {
+		t.Errorf("ReadAll failed: %v", err)
+	}
+
+	dec = NewDecoder(StdEncoding, bytes.NewBufferString(encodedShort))
+	var res2 []byte
+	res2, err = ioutil.ReadAll(dec)
+	if err != nil {
+		t.Errorf("ReadAll failed: %v", err)
+	}
+
+	if !bytes.Equal(res1, res2) {
+		t.Error("Decoded results not equal")
 	}
 }
diff --git a/src/pkg/encoding/base64/base64.go b/src/pkg/encoding/base64/base64.go
index e66672a1c..85e398fd0 100644
--- a/src/pkg/encoding/base64/base64.go
+++ b/src/pkg/encoding/base64/base64.go
@@ -6,8 +6,10 @@
 package base64
 
 import (
+	"bytes"
 	"io"
 	"strconv"
+	"strings"
 )
 
 /*
@@ -49,6 +51,13 @@ var StdEncoding = NewEncoding(encodeStd)
 // It is typically used in URLs and file names.
 var URLEncoding = NewEncoding(encodeURL)
 
+var removeNewlinesMapper = func(r rune) rune {
+	if r == '\r' || r == '\n' {
+		return -1
+	}
+	return r
+}
+
 /*
  * Encoder
  */
@@ -208,9 +217,10 @@ func (e CorruptInputError) Error() string {
 
 // decode is like Decode but returns an additional 'end' value, which
 // indicates if end-of-message padding was encountered and thus any
-// additional data is an error.
+// additional data is an error. This method assumes that src has been
+// stripped of all supported whitespace ('\r' and '\n').
 func (enc *Encoding) decode(dst, src []byte) (n int, end bool, err error) {
-	osrc := src
+	olen := len(src)
 	for len(src) > 0 && !end {
 		// Decode quantum using the base64 alphabet
 		var dbuf [4]byte
@@ -218,32 +228,26 @@ func (enc *Encoding) decode(dst, src []byte) (n int, end bool, err error) {
 
 		for j := 0; j < 4; {
 			if len(src) == 0 {
-				return n, false, CorruptInputError(len(osrc) - len(src) - j)
+				return n, false, CorruptInputError(olen - len(src) - j)
 			}
 			in := src[0]
 			src = src[1:]
-			if in == '\r' || in == '\n' {
-				// Ignore this character.
-				continue
-			}
 			if in == '=' && j >= 2 && len(src) < 4 {
-				// We've reached the end and there's
-				// padding
-				if len(src) == 0 && j == 2 {
+				// We've reached the end and there's padding
+				if len(src)+j < 4-1 {
 					// not enough padding
-					return n, false, CorruptInputError(len(osrc))
+					return n, false, CorruptInputError(olen)
 				}
 				if len(src) > 0 && src[0] != '=' {
 					// incorrect padding
-					return n, false, CorruptInputError(len(osrc) - len(src) - 1)
+					return n, false, CorruptInputError(olen - len(src) - 1)
 				}
-				dlen = j
-				end = true
+				dlen, end = j, true
 				break
 			}
 			dbuf[j] = enc.decodeMap[in]
 			if dbuf[j] == 0xFF {
-				return n, false, CorruptInputError(len(osrc) - len(src) - 1)
+				return n, false, CorruptInputError(olen - len(src) - 1)
 			}
 			j++
 		}
@@ -273,12 +277,14 @@ func (enc *Encoding) decode(dst, src []byte) (n int, end bool, err error) {
 // number of bytes successfully written and CorruptInputError.
 // New line characters (\r and \n) are ignored.
 func (enc *Encoding) Decode(dst, src []byte) (n int, err error) {
+	src = bytes.Map(removeNewlinesMapper, src)
 	n, _, err = enc.decode(dst, src)
 	return
 }
 
 // DecodeString returns the bytes represented by the base64 string s.
 func (enc *Encoding) DecodeString(s string) ([]byte, error) {
+	s = strings.Map(removeNewlinesMapper, s)
 	dbuf := make([]byte, enc.DecodedLen(len(s)))
 	n, err := enc.Decode(dbuf, []byte(s))
 	return dbuf[:n], err
@@ -343,9 +349,34 @@ func (d *decoder) Read(p []byte) (n int, err error) {
 	return n, d.err
 }
 
+type newlineFilteringReader struct {
+	wrapped io.Reader
+}
+
+func (r *newlineFilteringReader) Read(p []byte) (int, error) {
+	n, err := r.wrapped.Read(p)
+	for n > 0 {
+		offset := 0
+		for i, b := range p[0:n] {
+			if b != '\r' && b != '\n' {
+				if i != offset {
+					p[offset] = b
+				}
+				offset++
+			}
+		}
+		if offset > 0 {
+			return offset, err
+		}
+		// Previous buffer entirely whitespace, read again
+		n, err = r.wrapped.Read(p)
+	}
+	return n, err
+}
+
 // NewDecoder constructs a new base64 stream decoder.
 func NewDecoder(enc *Encoding, r io.Reader) io.Reader {
-	return &decoder{enc: enc, r: r}
+	return &decoder{enc: enc, r: &newlineFilteringReader{r}}
 }
 
 // DecodedLen returns the maximum length in bytes of the decoded data
diff --git a/src/pkg/encoding/base64/base64_test.go b/src/pkg/encoding/base64/base64_test.go
index 2166abd7a..579591a88 100644
--- a/src/pkg/encoding/base64/base64_test.go
+++ b/src/pkg/encoding/base64/base64_test.go
@@ -9,6 +9,7 @@ import (
 	"errors"
 	"io"
 	"io/ioutil"
+	"strings"
 	"testing"
 	"time"
 )
@@ -142,11 +143,11 @@ func TestDecoderBuffering(t *testing.T) {
 }
 
 func TestDecodeCorrupt(t *testing.T) {
-	type corrupt struct {
-		e string
-		p int
-	}
-	examples := []corrupt{
+	testCases := []struct {
+		input  string
+		offset int // -1 means no corruption.
+	}{
+		{"", -1},
 		{"!!!!", 0},
 		{"x===", 1},
 		{"AA=A", 2},
@@ -154,18 +155,27 @@ func TestDecodeCorrupt(t *testing.T) {
 		{"AAAAA", 4},
 		{"AAAAAA", 4},
 		{"A=", 1},
+		{"A==", 1},
 		{"AA=", 3},
+		{"AA==", -1},
+		{"AAA=", -1},
+		{"AAAA", -1},
 		{"AAAAAA=", 7},
 	}
-
-	for _, e := range examples {
-		dbuf := make([]byte, StdEncoding.DecodedLen(len(e.e)))
-		_, err := StdEncoding.Decode(dbuf, []byte(e.e))
+	for _, tc := range testCases {
+		dbuf := make([]byte, StdEncoding.DecodedLen(len(tc.input)))
+		_, err := StdEncoding.Decode(dbuf, []byte(tc.input))
+		if tc.offset == -1 {
+			if err != nil {
+				t.Error("Decoder wrongly detected coruption in", tc.input)
+			}
+			continue
+		}
 		switch err := err.(type) {
 		case CorruptInputError:
-			testEqual(t, "Corruption in %q at offset %v, want %v", e.e, int(err), e.p)
+			testEqual(t, "Corruption in %q at offset %v, want %v", tc.input, int(err), tc.offset)
 		default:
-			t.Error("Decoder failed to detect corruption in", e)
+			t.Error("Decoder failed to detect corruption in", tc)
 		}
 	}
 }
@@ -216,6 +226,8 @@ func TestNewLineCharacters(t *testing.T) {
 		"c3V\nyZ\rQ==",
 		"c3VyZ\nQ==",
 		"c3VyZQ\n==",
+		"c3VyZQ=\n=",
+		"c3VyZQ=\r\n\r\n=",
 	}
 	for _, e := range examples {
 		buf, err := StdEncoding.DecodeString(e)
@@ -276,3 +288,40 @@ func TestDecoderIssue3577(t *testing.T) {
 		t.Errorf("timeout; Decoder blocked without returning an error")
 	}
 }
+
+func TestDecoderIssue4779(t *testing.T) {
+	encoded := `CP/EAT8AAAEF
+AQEBAQEBAAAAAAAAAAMAAQIEBQYHCAkKCwEAAQUBAQEBAQEAAAAAAAAAAQACAwQFBgcICQoLEAAB
+BAEDAgQCBQcGCAUDDDMBAAIRAwQhEjEFQVFhEyJxgTIGFJGhsUIjJBVSwWIzNHKC0UMHJZJT8OHx
+Y3M1FqKygyZEk1RkRcKjdDYX0lXiZfKzhMPTdePzRieUpIW0lcTU5PSltcXV5fVWZnaGlqa2xtbm
+9jdHV2d3h5ent8fX5/cRAAICAQIEBAMEBQYHBwYFNQEAAhEDITESBEFRYXEiEwUygZEUobFCI8FS
+0fAzJGLhcoKSQ1MVY3M08SUGFqKygwcmNcLSRJNUoxdkRVU2dGXi8rOEw9N14/NGlKSFtJXE1OT0
+pbXF1eX1VmZ2hpamtsbW5vYnN0dXZ3eHl6e3x//aAAwDAQACEQMRAD8A9VSSSSUpJJJJSkkkJ+Tj
+1kiy1jCJJDnAcCTykpKkuQ6p/jN6FgmxlNduXawwAzaGH+V6jn/R/wCt71zdn+N/qL3kVYFNYB4N
+ji6PDVjWpKp9TSXnvTf8bFNjg3qOEa2n6VlLpj/rT/pf567DpX1i6L1hs9Py67X8mqdtg/rUWbbf
++gkp0kkkklKSSSSUpJJJJT//0PVUkkklKVLq3WMDpGI7KzrNjADtYNXvI/Mqr/Pd/q9W3vaxjnvM
+NaCXE9gNSvGPrf8AWS3qmba5jjsJhoB0DAf0NDf6sevf+/lf8Hj0JJATfWT6/dV6oXU1uOLQeKKn
+EQP+Hubtfe/+R7Mf/g7f5xcocp++Z11JMCJPgFBxOg7/AOuqDx8I/ikpkXkmSdU8mJIJA/O8EMAy
+j+mSARB/17pKVXYWHXjsj7yIex0PadzXMO1zT5KHoNA3HT8ietoGhgjsfA+CSnvvqh/jJtqsrwOv
+2b6NGNzXfTYexzJ+nU7/ALkf4P8Awv6P9KvTQQ4AgyDqCF85Pho3CTB7eHwXoH+LT65uZbX9X+o2
+bqbPb06551Y4
+`
+	encodedShort := strings.Replace(encoded, "\n", "", -1)
+
+	dec := NewDecoder(StdEncoding, bytes.NewBufferString(encoded))
+	res1, err := ioutil.ReadAll(dec)
+	if err != nil {
+		t.Errorf("ReadAll failed: %v", err)
+	}
+
+	dec = NewDecoder(StdEncoding, bytes.NewBufferString(encodedShort))
+	var res2 []byte
+	res2, err = ioutil.ReadAll(dec)
+	if err != nil {
+		t.Errorf("ReadAll failed: %v", err)
+	}
+
+	if !bytes.Equal(res1, res2) {
+		t.Error("Decoded results not equal")
+	}
+}
diff --git a/src/pkg/encoding/binary/varint.go b/src/pkg/encoding/binary/varint.go
index 7035529f2..3a2dfa3c7 100644
--- a/src/pkg/encoding/binary/varint.go
+++ b/src/pkg/encoding/binary/varint.go
@@ -120,7 +120,6 @@ func ReadUvarint(r io.ByteReader) (uint64, error) {
 		x |= uint64(b&0x7f) << s
 		s += 7
 	}
-	panic("unreachable")
 }
 
 // ReadVarint reads an encoded signed integer from r and returns it as an int64.
diff --git a/src/pkg/encoding/csv/reader.go b/src/pkg/encoding/csv/reader.go
index db4d98852..b099caf60 100644
--- a/src/pkg/encoding/csv/reader.go
+++ b/src/pkg/encoding/csv/reader.go
@@ -171,7 +171,6 @@ func (r *Reader) ReadAll() (records [][]string, err error) {
 		}
 		records = append(records, record)
 	}
-	panic("unreachable")
 }
 
 // readRune reads one rune from r, folding \r\n to \n and keeping track
@@ -213,7 +212,6 @@ func (r *Reader) skip(delim rune) error {
 			return nil
 		}
 	}
-	panic("unreachable")
 }
 
 // parseRecord reads and parses a single csv record from r.
@@ -250,7 +248,6 @@ func (r *Reader) parseRecord() (fields []string, err error) {
 			return nil, err
 		}
 	}
-	panic("unreachable")
 }
 
 // parseField parses the next field in the record.  The read field is
diff --git a/src/pkg/encoding/gob/codec_test.go b/src/pkg/encoding/gob/codec_test.go
index 482212b74..9e38e31d5 100644
--- a/src/pkg/encoding/gob/codec_test.go
+++ b/src/pkg/encoding/gob/codec_test.go
@@ -1191,10 +1191,8 @@ func TestInterface(t *testing.T) {
 			if v1 != nil || v2 != nil {
 				t.Errorf("item %d inconsistent nils", i)
 			}
-			continue
-			if v1.Square() != v2.Square() {
-				t.Errorf("item %d inconsistent values: %v %v", i, v1, v2)
-			}
+		} else if v1.Square() != v2.Square() {
+			t.Errorf("item %d inconsistent values: %v %v", i, v1, v2)
 		}
 	}
 }
diff --git a/src/pkg/encoding/gob/decode.go b/src/pkg/encoding/gob/decode.go
index a80d9f919..7cc756540 100644
--- a/src/pkg/encoding/gob/decode.go
+++ b/src/pkg/encoding/gob/decode.go
@@ -1066,7 +1066,6 @@ func (dec *Decoder) compatibleType(fr reflect.Type, fw typeId, inProgress map[re
 	case reflect.Struct:
 		return true
 	}
-	return true
 }
 
 // typeString returns a human-readable description of the type identified by remoteId.
diff --git a/src/pkg/encoding/gob/timing_test.go b/src/pkg/encoding/gob/timing_test.go
index 13eb11925..f589675dd 100644
--- a/src/pkg/encoding/gob/timing_test.go
+++ b/src/pkg/encoding/gob/timing_test.go
@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"runtime"
 	"testing"
 )
 
@@ -49,6 +50,10 @@ func BenchmarkEndToEndByteBuffer(b *testing.B) {
 }
 
 func TestCountEncodeMallocs(t *testing.T) {
+	if runtime.GOMAXPROCS(0) > 1 {
+		t.Skip("skipping; GOMAXPROCS>1")
+	}
+
 	const N = 1000
 
 	var buf bytes.Buffer
@@ -65,6 +70,10 @@ func TestCountEncodeMallocs(t *testing.T) {
 }
 
 func TestCountDecodeMallocs(t *testing.T) {
+	if runtime.GOMAXPROCS(0) > 1 {
+		t.Skip("skipping; GOMAXPROCS>1")
+	}
+
 	const N = 1000
 
 	var buf bytes.Buffer
diff --git a/src/pkg/encoding/gob/type.go b/src/pkg/encoding/gob/type.go
index ea0db4eac..7fa0b499f 100644
--- a/src/pkg/encoding/gob/type.go
+++ b/src/pkg/encoding/gob/type.go
@@ -526,7 +526,6 @@ func newTypeObject(name string, ut *userTypeInfo, rt reflect.Type) (gobType, err
 	default:
 		return nil, errors.New("gob NewTypeObject can't handle type: " + rt.String())
 	}
-	return nil, nil
 }
 
 // isExported reports whether this is an exported - upper case - name.
diff --git a/src/pkg/encoding/json/decode.go b/src/pkg/encoding/json/decode.go
index f2ec9cb67..62ac294b8 100644
--- a/src/pkg/encoding/json/decode.go
+++ b/src/pkg/encoding/json/decode.go
@@ -261,6 +261,16 @@ func (d *decodeState) value(v reflect.Value) {
 		}
 		d.scan.step(&d.scan, '"')
 		d.scan.step(&d.scan, '"')
+
+		n := len(d.scan.parseState)
+		if n > 0 && d.scan.parseState[n-1] == parseObjectKey {
+			// d.scan thinks we just read an object key; finish the object
+			d.scan.step(&d.scan, ':')
+			d.scan.step(&d.scan, '"')
+			d.scan.step(&d.scan, '"')
+			d.scan.step(&d.scan, '}')
+		}
+
 		return
 	}
 
@@ -739,6 +749,7 @@ func (d *decodeState) valueInterface() interface{} {
 	switch d.scanWhile(scanSkipSpace) {
 	default:
 		d.error(errPhase)
+		panic("unreachable")
 	case scanBeginArray:
 		return d.arrayInterface()
 	case scanBeginObject:
@@ -746,7 +757,6 @@ func (d *decodeState) valueInterface() interface{} {
 	case scanBeginLiteral:
 		return d.literalInterface()
 	}
-	panic("unreachable")
 }
 
 // arrayInterface is like array but returns []interface{}.
@@ -858,7 +868,6 @@ func (d *decodeState) literalInterface() interface{} {
 		}
 		return n
 	}
-	panic("unreachable")
 }
 
 // getu4 decodes \uXXXX from the beginning of s, returning the hex value,
diff --git a/src/pkg/encoding/json/decode_test.go b/src/pkg/encoding/json/decode_test.go
index e1bd918dd..037c5b236 100644
--- a/src/pkg/encoding/json/decode_test.go
+++ b/src/pkg/encoding/json/decode_test.go
@@ -1178,3 +1178,16 @@ func TestUnmarshalJSONLiteralError(t *testing.T) {
 		t.Errorf("got err = %v; want out of range error", err)
 	}
 }
+
+// Test that extra object elements in an array do not result in a
+// "data changing underfoot" error.
+// Issue 3717
+func TestSkipArrayObjects(t *testing.T) {
+	json := `[{}]`
+	var dest [0]interface{}
+
+	err := Unmarshal([]byte(json), &dest)
+	if err != nil {
+		t.Errorf("got error %q, want nil", err)
+	}
+}
diff --git a/src/pkg/encoding/xml/marshal.go b/src/pkg/encoding/xml/marshal.go
index ea58ce254..47b001763 100644
--- a/src/pkg/encoding/xml/marshal.go
+++ b/src/pkg/encoding/xml/marshal.go
@@ -120,11 +120,76 @@ func (enc *Encoder) Encode(v interface{}) error {
 
 type printer struct {
 	*bufio.Writer
+	seq        int
 	indent     string
 	prefix     string
 	depth      int
 	indentedIn bool
 	putNewline bool
+	attrNS     map[string]string // map prefix -> name space
+	attrPrefix map[string]string // map name space -> prefix
+}
+
+// createAttrPrefix finds the name space prefix attribute to use for the given name space,
+// defining a new prefix if necessary. It returns the prefix and whether it is new.
+func (p *printer) createAttrPrefix(url string) (prefix string, isNew bool) {
+	if prefix = p.attrPrefix[url]; prefix != "" {
+		return prefix, false
+	}
+
+	// The "http://www.w3.org/XML/1998/namespace" name space is predefined as "xml"
+	// and must be referred to that way.
+	// (The "http://www.w3.org/2000/xmlns/" name space is also predefined as "xmlns",
+	// but users should not be trying to use that one directly - that's our job.)
+	if url == xmlURL {
+		return "xml", false
+	}
+
+	// Need to define a new name space.
+	if p.attrPrefix == nil {
+		p.attrPrefix = make(map[string]string)
+		p.attrNS = make(map[string]string)
+	}
+
+	// Pick a name. We try to use the final element of the path
+	// but fall back to _.
+	prefix = strings.TrimRight(url, "/")
+	if i := strings.LastIndex(prefix, "/"); i >= 0 {
+		prefix = prefix[i+1:]
+	}
+	if prefix == "" || !isName([]byte(prefix)) || strings.Contains(prefix, ":") {
+		prefix = "_"
+	}
+	if strings.HasPrefix(prefix, "xml") {
+		// xmlanything is reserved.
+		prefix = "_" + prefix
+	}
+	if p.attrNS[prefix] != "" {
+		// Name is taken. Find a better one.
+		for p.seq++; ; p.seq++ {
+			if id := prefix + "_" + strconv.Itoa(p.seq); p.attrNS[id] == "" {
+				prefix = id
+				break
+			}
+		}
+	}
+
+	p.attrPrefix[url] = prefix
+	p.attrNS[prefix] = url
+
+	p.WriteString(`xmlns:`)
+	p.WriteString(prefix)
+	p.WriteString(`="`)
+	EscapeText(p, []byte(url))
+	p.WriteString(`" `)
+
+	return prefix, true
+}
+
+// deleteAttrPrefix removes an attribute name space prefix.
+func (p *printer) deleteAttrPrefix(prefix string) {
+	delete(p.attrPrefix, p.attrNS[prefix])
+	delete(p.attrNS, prefix)
 }
 
 // marshalValue writes one or more XML elements representing val.
@@ -210,6 +275,14 @@ func (p *printer) marshalValue(val reflect.Value, finfo *fieldInfo) error {
 			continue
 		}
 		p.WriteByte(' ')
+		if finfo.xmlns != "" {
+			prefix, created := p.createAttrPrefix(finfo.xmlns)
+			if created {
+				defer p.deleteAttrPrefix(prefix)
+			}
+			p.WriteString(prefix)
+			p.WriteByte(':')
+		}
 		p.WriteString(finfo.name)
 		p.WriteString(`="`)
 		if err := p.marshalSimple(fv.Type(), fv); err != nil {
@@ -286,7 +359,7 @@ func (p *printer) marshalStruct(tinfo *typeInfo, val reflect.Value) error {
 	s := parentStack{printer: p}
 	for i := range tinfo.fields {
 		finfo := &tinfo.fields[i]
-		if finfo.flags&(fAttr) != 0 {
+		if finfo.flags&fAttr != 0 {
 			continue
 		}
 		vf := finfo.value(val)
diff --git a/src/pkg/encoding/xml/marshal_test.go b/src/pkg/encoding/xml/marshal_test.go
index 3a190def6..ca14a1e53 100644
--- a/src/pkg/encoding/xml/marshal_test.go
+++ b/src/pkg/encoding/xml/marshal_test.go
@@ -266,6 +266,16 @@ type Plain struct {
 	V interface{}
 }
 
+type MyInt int
+
+type EmbedInt struct {
+	MyInt
+}
+
+type Strings struct {
+	X []string `xml:"A>B,omitempty"`
+}
+
 // Unless explicitly stated as such (or *Plain), all of the
 // tests below are two-way tests. When introducing new tests,
 // please try to make them two-way as well to ensure that
@@ -790,6 +800,17 @@ var marshalTests = []struct {
 		},
 		UnmarshalOnly: true,
 	},
+	{
+		ExpectXML: `<EmbedInt><MyInt>42</MyInt></EmbedInt>`,
+		Value: &EmbedInt{
+			MyInt: 42,
+		},
+	},
+	// Test omitempty with parent chain; see golang.org/issue/4168.
+	{
+		ExpectXML: `<Strings><A></A></Strings>`,
+		Value:     &Strings{},
+	},
 }
 
 func TestMarshal(t *testing.T) {
@@ -812,6 +833,10 @@ func TestMarshal(t *testing.T) {
 	}
 }
 
+type AttrParent struct {
+	X string `xml:"X>Y,attr"`
+}
+
 var marshalErrorTests = []struct {
 	Value interface{}
 	Err   string
@@ -839,6 +864,11 @@ var marshalErrorTests = []struct {
 		Value: &Domain{Comment: []byte("f--bar")},
 		Err:   `xml: comments must not contain "--"`,
 	},
+	// Reject parent chain with attr, never worked; see golang.org/issue/5033.
+	{
+		Value: &AttrParent{},
+		Err:   `xml: X>Y chain not valid with attr flag`,
+	},
 }
 
 var marshalIndentTests = []struct {
@@ -861,8 +891,12 @@ var marshalIndentTests = []struct {
 
 func TestMarshalErrors(t *testing.T) {
 	for idx, test := range marshalErrorTests {
-		_, err := Marshal(test.Value)
-		if err == nil || err.Error() != test.Err {
+		data, err := Marshal(test.Value)
+		if err == nil {
+			t.Errorf("#%d: marshal(%#v) = [success] %q, want error %v", idx, test.Value, data, test.Err)
+			continue
+		}
+		if err.Error() != test.Err {
 			t.Errorf("#%d: marshal(%#v) = [error] %v, want %v", idx, test.Value, err, test.Err)
 		}
 		if test.Kind != reflect.Invalid {
diff --git a/src/pkg/encoding/xml/read.go b/src/pkg/encoding/xml/read.go
index 344ab514e..a7a2a9655 100644
--- a/src/pkg/encoding/xml/read.go
+++ b/src/pkg/encoding/xml/read.go
@@ -263,7 +263,7 @@ func (p *Decoder) unmarshal(val reflect.Value, start *StartElement) error {
 				strv := finfo.value(sv)
 				// Look for attribute.
 				for _, a := range start.Attr {
-					if a.Name.Local == finfo.name {
+					if a.Name.Local == finfo.name && (finfo.xmlns == "" || finfo.xmlns == a.Name.Space) {
 						copyValue(strv, []byte(a.Value))
 						break
 					}
@@ -441,7 +441,7 @@ func (p *Decoder) unmarshalPath(tinfo *typeInfo, sv reflect.Value, parents []str
 Loop:
 	for i := range tinfo.fields {
 		finfo := &tinfo.fields[i]
-		if finfo.flags&fElement == 0 || len(finfo.parents) < len(parents) {
+		if finfo.flags&fElement == 0 || len(finfo.parents) < len(parents) || finfo.xmlns != "" && finfo.xmlns != start.Name.Space {
 			continue
 		}
 		for j := range parents {
@@ -493,7 +493,6 @@ Loop:
 			return true, nil
 		}
 	}
-	panic("unreachable")
 }
 
 // Skip reads tokens until it has consumed the end element
@@ -517,5 +516,4 @@ func (d *Decoder) Skip() error {
 			return nil
 		}
 	}
-	panic("unreachable")
 }
diff --git a/src/pkg/encoding/xml/read_test.go b/src/pkg/encoding/xml/read_test.go
index b45e2f0e6..7d28c5d7d 100644
--- a/src/pkg/encoding/xml/read_test.go
+++ b/src/pkg/encoding/xml/read_test.go
@@ -6,6 +6,7 @@ package xml
 
 import (
 	"reflect"
+	"strings"
 	"testing"
 	"time"
 )
@@ -399,3 +400,224 @@ func TestUnmarshalAttr(t *testing.T) {
 		t.Fatalf("Unmarshal with %s failed:\nhave %#v,\n want %#v", x, p3.Int, 1)
 	}
 }
+
+type Tables struct {
+	HTable string `xml:"http://www.w3.org/TR/html4/ table"`
+	FTable string `xml:"http://www.w3schools.com/furniture table"`
+}
+
+var tables = []struct {
+	xml string
+	tab Tables
+	ns  string
+}{
+	{
+		xml: `<Tables>` +
+			`<table xmlns="http://www.w3.org/TR/html4/">hello</table>` +
+			`<table xmlns="http://www.w3schools.com/furniture">world</table>` +
+			`</Tables>`,
+		tab: Tables{"hello", "world"},
+	},
+	{
+		xml: `<Tables>` +
+			`<table xmlns="http://www.w3schools.com/furniture">world</table>` +
+			`<table xmlns="http://www.w3.org/TR/html4/">hello</table>` +
+			`</Tables>`,
+		tab: Tables{"hello", "world"},
+	},
+	{
+		xml: `<Tables xmlns:f="http://www.w3schools.com/furniture" xmlns:h="http://www.w3.org/TR/html4/">` +
+			`<f:table>world</f:table>` +
+			`<h:table>hello</h:table>` +
+			`</Tables>`,
+		tab: Tables{"hello", "world"},
+	},
+	{
+		xml: `<Tables>` +
+			`<table>bogus</table>` +
+			`</Tables>`,
+		tab: Tables{},
+	},
+	{
+		xml: `<Tables>` +
+			`<table>only</table>` +
+			`</Tables>`,
+		tab: Tables{HTable: "only"},
+		ns:  "http://www.w3.org/TR/html4/",
+	},
+	{
+		xml: `<Tables>` +
+			`<table>only</table>` +
+			`</Tables>`,
+		tab: Tables{FTable: "only"},
+		ns:  "http://www.w3schools.com/furniture",
+	},
+	{
+		xml: `<Tables>` +
+			`<table>only</table>` +
+			`</Tables>`,
+		tab: Tables{},
+		ns:  "something else entirely",
+	},
+}
+
+func TestUnmarshalNS(t *testing.T) {
+	for i, tt := range tables {
+		var dst Tables
+		var err error
+		if tt.ns != "" {
+			d := NewDecoder(strings.NewReader(tt.xml))
+			d.DefaultSpace = tt.ns
+			err = d.Decode(&dst)
+		} else {
+			err = Unmarshal([]byte(tt.xml), &dst)
+		}
+		if err != nil {
+			t.Errorf("#%d: Unmarshal: %v", i, err)
+			continue
+		}
+		want := tt.tab
+		if dst != want {
+			t.Errorf("#%d: dst=%+v, want %+v", i, dst, want)
+		}
+	}
+}
+
+func TestMarshalNS(t *testing.T) {
+	dst := Tables{"hello", "world"}
+	data, err := Marshal(&dst)
+	if err != nil {
+		t.Fatalf("Marshal: %v", err)
+	}
+	want := `<Tables><table xmlns="http://www.w3.org/TR/html4/">hello</table><table xmlns="http://www.w3schools.com/furniture">world</table></Tables>`
+	str := string(data)
+	if str != want {
+		t.Errorf("have: %q\nwant: %q\n", str, want)
+	}
+}
+
+type TableAttrs struct {
+	TAttr TAttr
+}
+
+type TAttr struct {
+	HTable string `xml:"http://www.w3.org/TR/html4/ table,attr"`
+	FTable string `xml:"http://www.w3schools.com/furniture table,attr"`
+	Lang   string `xml:"http://www.w3.org/XML/1998/namespace lang,attr,omitempty"`
+	Other1 string `xml:"http://golang.org/xml/ other,attr,omitempty"`
+	Other2 string `xml:"http://golang.org/xmlfoo/ other,attr,omitempty"`
+	Other3 string `xml:"http://golang.org/json/ other,attr,omitempty"`
+	Other4 string `xml:"http://golang.org/2/json/ other,attr,omitempty"`
+}
+
+var tableAttrs = []struct {
+	xml string
+	tab TableAttrs
+	ns  string
+}{
+	{
+		xml: `<TableAttrs xmlns:f="http://www.w3schools.com/furniture" xmlns:h="http://www.w3.org/TR/html4/"><TAttr ` +
+			`h:table="hello" f:table="world" ` +
+			`/></TableAttrs>`,
+		tab: TableAttrs{TAttr{HTable: "hello", FTable: "world"}},
+	},
+	{
+		xml: `<TableAttrs><TAttr xmlns:f="http://www.w3schools.com/furniture" xmlns:h="http://www.w3.org/TR/html4/" ` +
+			`h:table="hello" f:table="world" ` +
+			`/></TableAttrs>`,
+		tab: TableAttrs{TAttr{HTable: "hello", FTable: "world"}},
+	},
+	{
+		xml: `<TableAttrs><TAttr ` +
+			`h:table="hello" f:table="world" xmlns:f="http://www.w3schools.com/furniture" xmlns:h="http://www.w3.org/TR/html4/" ` +
+			`/></TableAttrs>`,
+		tab: TableAttrs{TAttr{HTable: "hello", FTable: "world"}},
+	},
+	{
+		// Default space does not apply to attribute names.
+		xml: `<TableAttrs xmlns="http://www.w3schools.com/furniture" xmlns:h="http://www.w3.org/TR/html4/"><TAttr ` +
+			`h:table="hello" table="world" ` +
+			`/></TableAttrs>`,
+		tab: TableAttrs{TAttr{HTable: "hello", FTable: ""}},
+	},
+	{
+		// Default space does not apply to attribute names.
+		xml: `<TableAttrs xmlns:f="http://www.w3schools.com/furniture"><TAttr xmlns="http://www.w3.org/TR/html4/" ` +
+			`table="hello" f:table="world" ` +
+			`/></TableAttrs>`,
+		tab: TableAttrs{TAttr{HTable: "", FTable: "world"}},
+	},
+	{
+		xml: `<TableAttrs><TAttr ` +
+			`table="bogus" ` +
+			`/></TableAttrs>`,
+		tab: TableAttrs{},
+	},
+	{
+		// Default space does not apply to attribute names.
+		xml: `<TableAttrs xmlns:h="http://www.w3.org/TR/html4/"><TAttr ` +
+			`h:table="hello" table="world" ` +
+			`/></TableAttrs>`,
+		tab: TableAttrs{TAttr{HTable: "hello", FTable: ""}},
+		ns:  "http://www.w3schools.com/furniture",
+	},
+	{
+		// Default space does not apply to attribute names.
+		xml: `<TableAttrs xmlns:f="http://www.w3schools.com/furniture"><TAttr ` +
+			`table="hello" f:table="world" ` +
+			`/></TableAttrs>`,
+		tab: TableAttrs{TAttr{HTable: "", FTable: "world"}},
+		ns:  "http://www.w3.org/TR/html4/",
+	},
+	{
+		xml: `<TableAttrs><TAttr ` +
+			`table="bogus" ` +
+			`/></TableAttrs>`,
+		tab: TableAttrs{},
+		ns:  "something else entirely",
+	},
+}
+
+func TestUnmarshalNSAttr(t *testing.T) {
+	for i, tt := range tableAttrs {
+		var dst TableAttrs
+		var err error
+		if tt.ns != "" {
+			d := NewDecoder(strings.NewReader(tt.xml))
+			d.DefaultSpace = tt.ns
+			err = d.Decode(&dst)
+		} else {
+			err = Unmarshal([]byte(tt.xml), &dst)
+		}
+		if err != nil {
+			t.Errorf("#%d: Unmarshal: %v", i, err)
+			continue
+		}
+		want := tt.tab
+		if dst != want {
+			t.Errorf("#%d: dst=%+v, want %+v", i, dst, want)
+		}
+	}
+}
+
+func TestMarshalNSAttr(t *testing.T) {
+	src := TableAttrs{TAttr{"hello", "world", "en_US", "other1", "other2", "other3", "other4"}}
+	data, err := Marshal(&src)
+	if err != nil {
+		t.Fatalf("Marshal: %v", err)
+	}
+	want := `<TableAttrs><TAttr xmlns:html4="http://www.w3.org/TR/html4/" html4:table="hello" xmlns:furniture="http://www.w3schools.com/furniture" furniture:table="world" xml:lang="en_US" xmlns:_xml="http://golang.org/xml/" _xml:other="other1" xmlns:_xmlfoo="http://golang.org/xmlfoo/" _xmlfoo:other="other2" xmlns:json="http://golang.org/json/" json:other="other3" xmlns:json_1="http://golang.org/2/json/" json_1:other="other4"></TAttr></TableAttrs>`
+	str := string(data)
+	if str != want {
+		t.Errorf("Marshal:\nhave: %#q\nwant: %#q\n", str, want)
+	}
+
+	var dst TableAttrs
+	if err := Unmarshal(data, &dst); err != nil {
+		t.Errorf("Unmarshal: %v", err)
+	}
+
+	if dst != src {
+		t.Errorf("Unmarshal = %q, want %q", dst, src)
+	}
+}
diff --git a/src/pkg/encoding/xml/typeinfo.go b/src/pkg/encoding/xml/typeinfo.go
index bbeb28d87..83e65402c 100644
--- a/src/pkg/encoding/xml/typeinfo.go
+++ b/src/pkg/encoding/xml/typeinfo.go
@@ -70,20 +70,19 @@ func getTypeInfo(typ reflect.Type) (*typeInfo, error) {
 				if t.Kind() == reflect.Ptr {
 					t = t.Elem()
 				}
-				if t.Kind() != reflect.Struct {
-					continue
-				}
-				inner, err := getTypeInfo(t)
-				if err != nil {
-					return nil, err
-				}
-				for _, finfo := range inner.fields {
-					finfo.idx = append([]int{i}, finfo.idx...)
-					if err := addFieldInfo(typ, tinfo, &finfo); err != nil {
+				if t.Kind() == reflect.Struct {
+					inner, err := getTypeInfo(t)
+					if err != nil {
 						return nil, err
 					}
+					for _, finfo := range inner.fields {
+						finfo.idx = append([]int{i}, finfo.idx...)
+						if err := addFieldInfo(typ, tinfo, &finfo); err != nil {
+							return nil, err
+						}
+					}
+					continue
 				}
-				continue
 			}
 
 			finfo, err := structFieldInfo(typ, &f)
@@ -193,16 +192,19 @@ func structFieldInfo(typ reflect.Type, f *reflect.StructField) (*fieldInfo, erro
 	}
 
 	// Prepare field name and parents.
-	tokens = strings.Split(tag, ">")
-	if tokens[0] == "" {
-		tokens[0] = f.Name
+	parents := strings.Split(tag, ">")
+	if parents[0] == "" {
+		parents[0] = f.Name
 	}
-	if tokens[len(tokens)-1] == "" {
+	if parents[len(parents)-1] == "" {
 		return nil, fmt.Errorf("xml: trailing '>' in field %s of type %s", f.Name, typ)
 	}
-	finfo.name = tokens[len(tokens)-1]
-	if len(tokens) > 1 {
-		finfo.parents = tokens[:len(tokens)-1]
+	finfo.name = parents[len(parents)-1]
+	if len(parents) > 1 {
+		if (finfo.flags & fElement) == 0 {
+			return nil, fmt.Errorf("xml: %s chain not valid with %s flag", tag, strings.Join(tokens[1:], ","))
+		}
+		finfo.parents = parents[:len(parents)-1]
 	}
 
 	// If the field type has an XMLName field, the names must match
@@ -268,6 +270,9 @@ Loop:
 		if oldf.flags&fMode != newf.flags&fMode {
 			continue
 		}
+		if oldf.xmlns != "" && newf.xmlns != "" && oldf.xmlns != newf.xmlns {
+			continue
+		}
 		minl := min(len(newf.parents), len(oldf.parents))
 		for p := 0; p < minl; p++ {
 			if oldf.parents[p] != newf.parents[p] {
diff --git a/src/pkg/encoding/xml/xml.go b/src/pkg/encoding/xml/xml.go
index 143fec554..021f7e47d 100644
--- a/src/pkg/encoding/xml/xml.go
+++ b/src/pkg/encoding/xml/xml.go
@@ -169,6 +169,11 @@ type Decoder struct {
 	// the CharsetReader's result values must be non-nil.
 	CharsetReader func(charset string, input io.Reader) (io.Reader, error)
 
+	// DefaultSpace sets the default name space used for unadorned tags,
+	// as if the entire XML stream were wrapped in an element containing
+	// the attribute xmlns="DefaultSpace".
+	DefaultSpace string
+
 	r         io.ByteReader
 	buf       bytes.Buffer
 	saved     *bytes.Buffer
@@ -268,6 +273,8 @@ func (d *Decoder) Token() (t Token, err error) {
 	return
 }
 
+const xmlURL = "http://www.w3.org/XML/1998/namespace"
+
 // Apply name space translation to name n.
 // The default name space (for Space=="")
 // applies only to element names, not to attribute names.
@@ -277,11 +284,15 @@ func (d *Decoder) translate(n *Name, isElementName bool) {
 		return
 	case n.Space == "" && !isElementName:
 		return
+	case n.Space == "xml":
+		n.Space = xmlURL
 	case n.Space == "" && n.Local == "xmlns":
 		return
 	}
 	if v, ok := d.ns[n.Space]; ok {
 		n.Space = v
+	} else if n.Space == "" {
+		n.Space = d.DefaultSpace
 	}
 }
 
@@ -956,7 +967,7 @@ Input:
 				b0, b1 = 0, 0
 				continue Input
 			}
-			ent := string(d.buf.Bytes()[before])
+			ent := string(d.buf.Bytes()[before:])
 			if ent[len(ent)-1] != ';' {
 				ent += " (no semicolon)"
 			}
@@ -1718,6 +1729,7 @@ var (
 	esc_tab  = []byte("&#x9;")
 	esc_nl   = []byte("&#xA;")
 	esc_cr   = []byte("&#xD;")
+	esc_fffd = []byte("\uFFFD") // Unicode replacement character
 )
 
 // EscapeText writes to w the properly escaped XML equivalent
@@ -1725,8 +1737,10 @@ var (
 func EscapeText(w io.Writer, s []byte) error {
 	var esc []byte
 	last := 0
-	for i, c := range s {
-		switch c {
+	for i := 0; i < len(s); {
+		r, width := utf8.DecodeRune(s[i:])
+		i += width
+		switch r {
 		case '"':
 			esc = esc_quot
 		case '\'':
@@ -1744,15 +1758,19 @@ func EscapeText(w io.Writer, s []byte) error {
 		case '\r':
 			esc = esc_cr
 		default:
+			if !isInCharacterRange(r) {
+				esc = esc_fffd
+				break
+			}
 			continue
 		}
-		if _, err := w.Write(s[last:i]); err != nil {
+		if _, err := w.Write(s[last : i-width]); err != nil {
 			return err
 		}
 		if _, err := w.Write(esc); err != nil {
 			return err
 		}
-		last = i + 1
+		last = i
 	}
 	if _, err := w.Write(s[last:]); err != nil {
 		return err
diff --git a/src/pkg/encoding/xml/xml_test.go b/src/pkg/encoding/xml/xml_test.go
index 54dab5484..eeedbe575 100644
--- a/src/pkg/encoding/xml/xml_test.go
+++ b/src/pkg/encoding/xml/xml_test.go
@@ -5,6 +5,7 @@
 package xml
 
 import (
+	"bytes"
 	"fmt"
 	"io"
 	"reflect"
@@ -595,13 +596,6 @@ func TestEntityInsideCDATA(t *testing.T) {
 	}
 }
 
-// The last three tests (respectively one for characters in attribute
-// names and two for character entities) pass not because of code
-// changed for issue 1259, but instead pass with the given messages
-// from other parts of xml.Decoder.  I provide these to note the
-// current behavior of situations where one might think that character
-// range checking would detect the error, but it does not in fact.
-
 var characterTests = []struct {
 	in  string
 	err string
@@ -611,8 +605,10 @@ var characterTests = []struct {
 	{"\xef\xbf\xbe<doc/>", "illegal character code U+FFFE"},
 	{"<?xml version=\"1.0\"?><doc>\r\n<hiya/>\x07<toots/></doc>", "illegal character code U+0007"},
 	{"<?xml version=\"1.0\"?><doc \x12='value'>what's up</doc>", "expected attribute name in element"},
+	{"<doc>&abc\x01;</doc>", "invalid character entity &abc (no semicolon)"},
 	{"<doc>&\x01;</doc>", "invalid character entity & (no semicolon)"},
-	{"<doc>&\xef\xbf\xbe;</doc>", "invalid character entity & (no semicolon)"},
+	{"<doc>&\xef\xbf\xbe;</doc>", "invalid character entity &\uFFFE;"},
+	{"<doc>&hello;</doc>", "invalid character entity &hello;"},
 }
 
 func TestDisallowedCharacters(t *testing.T) {
@@ -629,7 +625,7 @@ func TestDisallowedCharacters(t *testing.T) {
 			t.Fatalf("input %d d.Token() = _, %v, want _, *SyntaxError", i, err)
 		}
 		if synerr.Msg != tt.err {
-			t.Fatalf("input %d synerr.Msg wrong: want '%s', got '%s'", i, tt.err, synerr.Msg)
+			t.Fatalf("input %d synerr.Msg wrong: want %q, got %q", i, tt.err, synerr.Msg)
 		}
 	}
 }
@@ -700,6 +696,21 @@ func TestEscapeTextIOErrors(t *testing.T) {
 	err := EscapeText(errWriter{}, []byte{'A'})
 
 	if err == nil || err.Error() != expectErr {
-		t.Errorf("EscapeTest = [error] %v, want %v", err, expectErr)
+		t.Errorf("have %v, want %v", err, expectErr)
+	}
+}
+
+func TestEscapeTextInvalidChar(t *testing.T) {
+	input := []byte("A \x00 terminated string.")
+	expected := "A \uFFFD terminated string."
+
+	buff := new(bytes.Buffer)
+	if err := EscapeText(buff, input); err != nil {
+		t.Fatalf("have %v, want nil", err)
+	}
+	text := buff.String()
+
+	if text != expected {
+		t.Errorf("have %v, want %v", text, expected)
 	}
 }