libgo: Merge from revision 18783:00cce3a34d7e of master library.

This revision was committed January 7, 2014.  The next
revision deleted runtime/mfinal.c.  That will be done in a
subsequent merge.

This merge changes type descriptors to add a zero field,
pointing to a zero value for that type.  This is implemented
as a common variable.

	* go-gcc.cc (Gcc_backend::implicit_variable): Add is_common and
	alignment parameters.  Permit init parameter to be NULL.

From-SVN: r211249

14 files changed, 445 insertions, 42 deletions

diff --git a/libgo/go/encoding/ascii85/ascii85_test.go b/libgo/go/encoding/ascii85/ascii85_test.go
index 42cf7e8..dc1134d 100644
--- a/libgo/go/encoding/ascii85/ascii85_test.go
+++ b/libgo/go/encoding/ascii85/ascii85_test.go
@@ -16,6 +16,11 @@ type testpair struct {
 }
 
 var pairs = []testpair{
+	// Encode returns 0 when len(src) is 0
+	{
+		"",
+		"",
+	},
 	// Wikipedia example
 	{
 		"Man is distinguished, not only by his reason, but by this singular passion from " +
diff --git a/libgo/go/encoding/asn1/asn1.go b/libgo/go/encoding/asn1/asn1.go
index 992356c..dfcbf92 100644
--- a/libgo/go/encoding/asn1/asn1.go
+++ b/libgo/go/encoding/asn1/asn1.go
@@ -451,11 +451,13 @@ func parseSequenceOf(bytes []byte, sliceType reflect.Type, elemType reflect.Type
 		if err != nil {
 			return
 		}
-		// We pretend that GENERAL STRINGs are PRINTABLE STRINGs so
-		// that a sequence of them can be parsed into a []string.
-		if t.tag == tagGeneralString {
+		// We pretend that various other string types are PRINTABLE STRINGs
+		// so that a sequence of them can be parsed into a []string.
+		switch t.tag {
+		case tagIA5String, tagGeneralString, tagT61String, tagUTF8String:
 			t.tag = tagPrintableString
 		}
+
 		if t.class != classUniversal || t.isCompound != compoundType || t.tag != expectedTag {
 			err = StructuralError{"sequence tag mismatch"}
 			return
diff --git a/libgo/go/encoding/asn1/asn1_test.go b/libgo/go/encoding/asn1/asn1_test.go
index f68804e..ea98e02 100644
--- a/libgo/go/encoding/asn1/asn1_test.go
+++ b/libgo/go/encoding/asn1/asn1_test.go
@@ -6,6 +6,7 @@ package asn1
 
 import (
 	"bytes"
+	"fmt"
 	"math/big"
 	"reflect"
 	"testing"
@@ -171,6 +172,12 @@ func TestBitStringAt(t *testing.T) {
 	if bs.At(9) != 1 {
 		t.Error("#4: Failed")
 	}
+	if bs.At(-1) != 0 {
+		t.Error("#5: Failed")
+	}
+	if bs.At(17) != 0 {
+		t.Error("#6: Failed")
+	}
 }
 
 type bitStringRightAlignTest struct {
@@ -238,6 +245,7 @@ var utcTestData = []timeTest{
 	{"910506164540+0730", true, time.Date(1991, 05, 06, 16, 45, 40, 0, time.FixedZone("", 7*60*60+30*60))},
 	{"910506234540Z", true, time.Date(1991, 05, 06, 23, 45, 40, 0, time.UTC)},
 	{"9105062345Z", true, time.Date(1991, 05, 06, 23, 45, 0, 0, time.UTC)},
+	{"5105062345Z", true, time.Date(1951, 05, 06, 23, 45, 0, 0, time.UTC)},
 	{"a10506234540Z", false, time.Time{}},
 	{"91a506234540Z", false, time.Time{}},
 	{"9105a6234540Z", false, time.Time{}},
@@ -509,6 +517,38 @@ func TestRawStructs(t *testing.T) {
 	}
 }
 
+type oiEqualTest struct {
+	first  ObjectIdentifier
+	second ObjectIdentifier
+	same   bool
+}
+
+var oiEqualTests = []oiEqualTest{
+	{
+		ObjectIdentifier{1, 2, 3},
+		ObjectIdentifier{1, 2, 3},
+		true,
+	},
+	{
+		ObjectIdentifier{1},
+		ObjectIdentifier{1, 2, 3},
+		false,
+	},
+	{
+		ObjectIdentifier{1, 2, 3},
+		ObjectIdentifier{10, 11, 12},
+		false,
+	},
+}
+
+func TestObjectIdentifierEqual(t *testing.T) {
+	for _, o := range oiEqualTests {
+		if s := o.first.Equal(o.second); s != o.same {
+			t.Errorf("ObjectIdentifier.Equal: got: %t want: %t", s, o.same)
+		}
+	}
+}
+
 var derEncodedSelfSignedCert = Certificate{
 	TBSCertificate: TBSCertificate{
 		Version:            0,
@@ -737,3 +777,29 @@ var derEncodedPaypalNULCertBytes = []byte{
 	0xc8, 0x64, 0x8c, 0xb5, 0x50, 0x23, 0x82, 0x6f, 0xdb, 0xb8, 0x22, 0x1c, 0x43,
 	0x96, 0x07, 0xa8, 0xbb,
 }
+
+var stringSliceTestData = [][]string{
+	{"foo", "bar"},
+	{"foo", "\\bar"},
+	{"foo", "\"bar\""},
+	{"foo", "åäö"},
+}
+
+func TestStringSlice(t *testing.T) {
+	for _, test := range stringSliceTestData {
+		bs, err := Marshal(test)
+		if err != nil {
+			t.Error(err)
+		}
+
+		var res []string
+		_, err = Unmarshal(bs, &res)
+		if err != nil {
+			t.Error(err)
+		}
+
+		if fmt.Sprintf("%v", res) != fmt.Sprintf("%v", test) {
+			t.Errorf("incorrect marshal/unmarshal; %v != %v", res, test)
+		}
+	}
+}
diff --git a/libgo/go/encoding/csv/reader.go b/libgo/go/encoding/csv/reader.go
index b328dcc..d943295 100644
--- a/libgo/go/encoding/csv/reader.go
+++ b/libgo/go/encoding/csv/reader.go
@@ -193,12 +193,6 @@ func (r *Reader) readRune() (rune, error) {
 	return r1, err
 }
 
-// unreadRune puts the last rune read from r back.
-func (r *Reader) unreadRune() {
-	r.r.UnreadRune()
-	r.column--
-}
-
 // skip reads runes up to and including the rune delim or until error.
 func (r *Reader) skip(delim rune) error {
 	for {
diff --git a/libgo/go/encoding/csv/writer_test.go b/libgo/go/encoding/csv/writer_test.go
index 03ca6b0..22b740c 100644
--- a/libgo/go/encoding/csv/writer_test.go
+++ b/libgo/go/encoding/csv/writer_test.go
@@ -26,6 +26,8 @@ var writeTests = []struct {
 	{Input: [][]string{{"abc"}, {"def"}}, Output: "abc\ndef\n"},
 	{Input: [][]string{{"abc\ndef"}}, Output: "\"abc\ndef\"\n"},
 	{Input: [][]string{{"abc\ndef"}}, Output: "\"abc\r\ndef\"\r\n", UseCRLF: true},
+	{Input: [][]string{{"abc\rdef"}}, Output: "\"abcdef\"\r\n", UseCRLF: true},
+	{Input: [][]string{{"abc\rdef"}}, Output: "\"abc\rdef\"\n", UseCRLF: false},
 }
 
 func TestWrite(t *testing.T) {
diff --git a/libgo/go/encoding/gob/decode.go b/libgo/go/encoding/gob/decode.go
index 3e76f4c..3037a58 100644
--- a/libgo/go/encoding/gob/decode.go
+++ b/libgo/go/encoding/gob/decode.go
@@ -654,21 +654,20 @@ func (dec *Decoder) ignoreMap(state *decoderState, keyOp, elemOp decOp) {
 
 // decodeSlice decodes a slice and stores the slice header through p.
 // Slices are encoded as an unsigned length followed by the elements.
-func (dec *Decoder) decodeSlice(atyp reflect.Type, state *decoderState, p uintptr, elemOp decOp, elemWid uintptr, indir, elemIndir int, ovfl error) {
+func (dec *Decoder) decodeSlice(atyp reflect.Type, state *decoderState, p unsafe.Pointer, elemOp decOp, elemWid uintptr, indir, elemIndir int, ovfl error) {
 	nr := state.decodeUint()
 	n := int(nr)
 	if indir > 0 {
-		up := unsafe.Pointer(p)
-		if *(*unsafe.Pointer)(up) == nil {
+		if *(*unsafe.Pointer)(p) == nil {
 			// Allocate the slice header.
-			*(*unsafe.Pointer)(up) = unsafe.Pointer(new([]unsafe.Pointer))
+			*(*unsafe.Pointer)(p) = unsafe.Pointer(new([]unsafe.Pointer))
 		}
-		p = *(*uintptr)(up)
+		p = *(*unsafe.Pointer)(p)
 	}
 	// Allocate storage for the slice elements, that is, the underlying array,
 	// if the existing slice does not have the capacity.
 	// Always write a header at p.
-	hdrp := (*reflect.SliceHeader)(unsafe.Pointer(p))
+	hdrp := (*reflect.SliceHeader)(p)
 	if hdrp.Cap < n {
 		hdrp.Data = reflect.MakeSlice(atyp, n, n).Pointer()
 		hdrp.Cap = n
@@ -887,7 +886,7 @@ func (dec *Decoder) decOpFor(wireId typeId, rt reflect.Type, name string, inProg
 			elemOp, elemIndir := dec.decOpFor(elemId, t.Elem(), name, inProgress)
 			ovfl := overflow(name)
 			op = func(i *decInstr, state *decoderState, p unsafe.Pointer) {
-				state.dec.decodeSlice(t, state, uintptr(p), *elemOp, t.Elem().Size(), i.indir, elemIndir, ovfl)
+				state.dec.decodeSlice(t, state, p, *elemOp, t.Elem().Size(), i.indir, elemIndir, ovfl)
 			}
 
 		case reflect.Struct:
diff --git a/libgo/go/encoding/hex/hex_test.go b/libgo/go/encoding/hex/hex_test.go
index 356f590..b969636 100644
--- a/libgo/go/encoding/hex/hex_test.go
+++ b/libgo/go/encoding/hex/hex_test.go
@@ -38,7 +38,10 @@ func TestEncode(t *testing.T) {
 }
 
 func TestDecode(t *testing.T) {
-	for i, test := range encDecTests {
+	// Case for decoding uppercase hex characters, since
+	// Encode always uses lowercase.
+	decTests := append(encDecTests, encDecTest{"F8F9FAFBFCFDFEFF", []byte{0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff}})
+	for i, test := range decTests {
 		dst := make([]byte, DecodedLen(len(test.enc)))
 		n, err := Decode(dst, []byte(test.enc))
 		if err != nil {
@@ -79,6 +82,7 @@ type errTest struct {
 var errTests = []errTest{
 	{"0", "encoding/hex: odd length hex string"},
 	{"0g", "encoding/hex: invalid byte: U+0067 'g'"},
+	{"00gg", "encoding/hex: invalid byte: U+0067 'g'"},
 	{"0\x01", "encoding/hex: invalid byte: U+0001"},
 }
 
diff --git a/libgo/go/encoding/json/decode.go b/libgo/go/encoding/json/decode.go
index 458fb39..dde0d78 100644
--- a/libgo/go/encoding/json/decode.go
+++ b/libgo/go/encoding/json/decode.go
@@ -8,6 +8,7 @@
 package json
 
 import (
+	"bytes"
 	"encoding"
 	"encoding/base64"
 	"errors"
@@ -15,7 +16,6 @@ import (
 	"reflect"
 	"runtime"
 	"strconv"
-	"strings"
 	"unicode"
 	"unicode/utf16"
 	"unicode/utf8"
@@ -500,11 +500,11 @@ func (d *decodeState) object(v reflect.Value) {
 			d.error(errPhase)
 		}
 
-		// Read string key.
+		// Read key.
 		start := d.off - 1
 		op = d.scanWhile(scanContinue)
 		item := d.data[start : d.off-1]
-		key, ok := unquote(item)
+		key, ok := unquoteBytes(item)
 		if !ok {
 			d.error(errPhase)
 		}
@@ -526,11 +526,11 @@ func (d *decodeState) object(v reflect.Value) {
 			fields := cachedTypeFields(v.Type())
 			for i := range fields {
 				ff := &fields[i]
-				if ff.name == key {
+				if bytes.Equal(ff.nameBytes, key) {
 					f = ff
 					break
 				}
-				if f == nil && strings.EqualFold(ff.name, key) {
+				if f == nil && ff.equalFold(ff.nameBytes, key) {
 					f = ff
 				}
 			}
@@ -561,6 +561,7 @@ func (d *decodeState) object(v reflect.Value) {
 		if destring {
 			d.value(reflect.ValueOf(&d.tempstr))
 			d.literalStore([]byte(d.tempstr), subv, true)
+			d.tempstr = "" // Zero scratch space for successive values.
 		} else {
 			d.value(subv)
 		}
diff --git a/libgo/go/encoding/json/decode_test.go b/libgo/go/encoding/json/decode_test.go
index 22c5f89..238a87f 100644
--- a/libgo/go/encoding/json/decode_test.go
+++ b/libgo/go/encoding/json/decode_test.go
@@ -1060,6 +1060,21 @@ func TestEmptyString(t *testing.T) {
 	}
 }
 
+// Test that the returned error is non-nil when trying to unmarshal null string into int, for successive ,string option
+// Issue 7046
+func TestNullString(t *testing.T) {
+	type T struct {
+		A int `json:",string"`
+		B int `json:",string"`
+	}
+	data := []byte(`{"A": "1", "B": null}`)
+	var s T
+	err := Unmarshal(data, &s)
+	if err == nil {
+		t.Fatalf("expected error; got %v", s)
+	}
+}
+
 func intp(x int) *int {
 	p := new(int)
 	*p = x
@@ -1110,8 +1125,8 @@ func TestInterfaceSet(t *testing.T) {
 // Issue 2540
 func TestUnmarshalNulls(t *testing.T) {
 	jsonData := []byte(`{
-		"Bool"    : null, 
-		"Int"     : null, 
+		"Bool"    : null,
+		"Int"     : null,
 		"Int8"    : null,
 		"Int16"   : null,
 		"Int32"   : null,
@@ -1316,3 +1331,26 @@ func TestPrefilled(t *testing.T) {
 		}
 	}
 }
+
+var invalidUnmarshalTests = []struct {
+	v    interface{}
+	want string
+}{
+	{nil, "json: Unmarshal(nil)"},
+	{struct{}{}, "json: Unmarshal(non-pointer struct {})"},
+	{(*int)(nil), "json: Unmarshal(nil *int)"},
+}
+
+func TestInvalidUnmarshal(t *testing.T) {
+	buf := []byte(`{"a":"1"}`)
+	for _, tt := range invalidUnmarshalTests {
+		err := Unmarshal(buf, tt.v)
+		if err == nil {
+			t.Errorf("Unmarshal expecting error, got nil")
+			continue
+		}
+		if got := err.Error(); got != tt.want {
+			t.Errorf("Unmarshal = %q; want %q", got, tt.want)
+		}
+	}
+}
diff --git a/libgo/go/encoding/json/encode.go b/libgo/go/encoding/json/encode.go
index 7d6c71d..4a77ba1 100644
--- a/libgo/go/encoding/json/encode.go
+++ b/libgo/go/encoding/json/encode.go
@@ -241,24 +241,15 @@ type encodeState struct {
 	scratch      [64]byte
 }
 
-// TODO(bradfitz): use a sync.Cache here
-var encodeStatePool = make(chan *encodeState, 8)
+var encodeStatePool sync.Pool
 
 func newEncodeState() *encodeState {
-	select {
-	case e := <-encodeStatePool:
+	if v := encodeStatePool.Get(); v != nil {
+		e := v.(*encodeState)
 		e.Reset()
 		return e
-	default:
-		return new(encodeState)
-	}
-}
-
-func putEncodeState(e *encodeState) {
-	select {
-	case encodeStatePool <- e:
-	default:
 	}
+	return new(encodeState)
 }
 
 func (e *encodeState) marshal(v interface{}) (err error) {
@@ -936,6 +927,9 @@ func (e *encodeState) stringBytes(s []byte) (int, error) {
 // A field represents a single field found in a struct.
 type field struct {
 	name      string
+	nameBytes []byte                 // []byte(name)
+	equalFold func(s, t []byte) bool // bytes.EqualFold or equivalent
+
 	tag       bool
 	index     []int
 	typ       reflect.Type
@@ -943,6 +937,12 @@ type field struct {
 	quoted    bool
 }
 
+func fillField(f field) field {
+	f.nameBytes = []byte(f.name)
+	f.equalFold = foldFunc(f.nameBytes)
+	return f
+}
+
 // byName sorts field by name, breaking ties with depth,
 // then breaking ties with "name came from json tag", then
 // breaking ties with index sequence.
@@ -1042,8 +1042,14 @@ func typeFields(t reflect.Type) []field {
 					if name == "" {
 						name = sf.Name
 					}
-					fields = append(fields, field{name, tagged, index, ft,
-						opts.Contains("omitempty"), opts.Contains("string")})
+					fields = append(fields, fillField(field{
+						name:      name,
+						tag:       tagged,
+						index:     index,
+						typ:       ft,
+						omitEmpty: opts.Contains("omitempty"),
+						quoted:    opts.Contains("string"),
+					}))
 					if count[f.typ] > 1 {
 						// If there were multiple instances, add a second,
 						// so that the annihilation code will see a duplicate.
@@ -1057,7 +1063,7 @@ func typeFields(t reflect.Type) []field {
 				// Record new anonymous struct to explore in next round.
 				nextCount[ft]++
 				if nextCount[ft] == 1 {
-					next = append(next, field{name: ft.Name(), index: index, typ: ft})
+					next = append(next, fillField(field{name: ft.Name(), index: index, typ: ft}))
 				}
 			}
 		}
diff --git a/libgo/go/encoding/json/encode_test.go b/libgo/go/encoding/json/encode_test.go
index 9395db7..265a237 100644
--- a/libgo/go/encoding/json/encode_test.go
+++ b/libgo/go/encoding/json/encode_test.go
@@ -25,13 +25,30 @@ type Optionals struct {
 
 	Mr map[string]interface{} `json:"mr"`
 	Mo map[string]interface{} `json:",omitempty"`
+
+	Fr float64 `json:"fr"`
+	Fo float64 `json:"fo,omitempty"`
+
+	Br bool `json:"br"`
+	Bo bool `json:"bo,omitempty"`
+
+	Ur uint `json:"ur"`
+	Uo uint `json:"uo,omitempty"`
+
+	Str struct{} `json:"str"`
+	Sto struct{} `json:"sto,omitempty"`
 }
 
 var optionalsExpected = `{
  "sr": "",
  "omitempty": 0,
  "slr": null,
- "mr": {}
+ "mr": {},
+ "fr": 0,
+ "br": false,
+ "ur": 0,
+ "str": {},
+ "sto": {}
 }`
 
 func TestOmitEmpty(t *testing.T) {
@@ -425,3 +442,13 @@ func TestIssue6458(t *testing.T) {
 		t.Errorf("Marshal(x) = %#q; want %#q", b, want)
 	}
 }
+
+func TestHTMLEscape(t *testing.T) {
+	var b, want bytes.Buffer
+	m := `{"M":"<html>foo &` + "\xe2\x80\xa8 \xe2\x80\xa9" + `</html>"}`
+	want.Write([]byte(`{"M":"\u003chtml\u003efoo \u0026\u2028 \u2029\u003c/html\u003e"}`))
+	HTMLEscape(&b, []byte(m))
+	if !bytes.Equal(b.Bytes(), want.Bytes()) {
+		t.Errorf("HTMLEscape(&b, []byte(m)) = %s; want %s", b.Bytes(), want.Bytes())
+	}
+}
diff --git a/libgo/go/encoding/json/fold.go b/libgo/go/encoding/json/fold.go
new file mode 100644
index 0000000..d6f77c9
--- /dev/null
+++ b/libgo/go/encoding/json/fold.go
@@ -0,0 +1,143 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json
+
+import (
+	"bytes"
+	"unicode/utf8"
+)
+
+const (
+	caseMask     = ^byte(0x20) // Mask to ignore case in ASCII.
+	kelvin       = '\u212a'
+	smallLongEss = '\u017f'
+)
+
+// foldFunc returns one of four different case folding equivalence
+// functions, from most general (and slow) to fastest:
+//
+// 1) bytes.EqualFold, if the key s contains any non-ASCII UTF-8
+// 2) equalFoldRight, if s contains special folding ASCII ('k', 'K', 's', 'S')
+// 3) asciiEqualFold, no special, but includes non-letters (including _)
+// 4) simpleLetterEqualFold, no specials, no non-letters.
+//
+// The letters S and K are special because they map to 3 runes, not just 2:
+//  * S maps to s and to U+017F 'ſ' Latin small letter long s
+//  * k maps to K and to U+212A 'K' Kelvin sign
+// See http://play.golang.org/p/tTxjOc0OGo
+//
+// The returned function is specialized for matching against s and
+// should only be given s. It's not curried for performance reasons.
+func foldFunc(s []byte) func(s, t []byte) bool {
+	nonLetter := false
+	special := false // special letter
+	for _, b := range s {
+		if b >= utf8.RuneSelf {
+			return bytes.EqualFold
+		}
+		upper := b & caseMask
+		if upper < 'A' || upper > 'Z' {
+			nonLetter = true
+		} else if upper == 'K' || upper == 'S' {
+			// See above for why these letters are special.
+			special = true
+		}
+	}
+	if special {
+		return equalFoldRight
+	}
+	if nonLetter {
+		return asciiEqualFold
+	}
+	return simpleLetterEqualFold
+}
+
+// equalFoldRight is a specialization of bytes.EqualFold when s is
+// known to be all ASCII (including punctuation), but contains an 's',
+// 'S', 'k', or 'K', requiring a Unicode fold on the bytes in t.
+// See comments on foldFunc.
+func equalFoldRight(s, t []byte) bool {
+	for _, sb := range s {
+		if len(t) == 0 {
+			return false
+		}
+		tb := t[0]
+		if tb < utf8.RuneSelf {
+			if sb != tb {
+				sbUpper := sb & caseMask
+				if 'A' <= sbUpper && sbUpper <= 'Z' {
+					if sbUpper != tb&caseMask {
+						return false
+					}
+				} else {
+					return false
+				}
+			}
+			t = t[1:]
+			continue
+		}
+		// sb is ASCII and t is not. t must be either kelvin
+		// sign or long s; sb must be s, S, k, or K.
+		tr, size := utf8.DecodeRune(t)
+		switch sb {
+		case 's', 'S':
+			if tr != smallLongEss {
+				return false
+			}
+		case 'k', 'K':
+			if tr != kelvin {
+				return false
+			}
+		default:
+			return false
+		}
+		t = t[size:]
+
+	}
+	if len(t) > 0 {
+		return false
+	}
+	return true
+}
+
+// asciiEqualFold is a specialization of bytes.EqualFold for use when
+// s is all ASCII (but may contain non-letters) and contains no
+// special-folding letters.
+// See comments on foldFunc.
+func asciiEqualFold(s, t []byte) bool {
+	if len(s) != len(t) {
+		return false
+	}
+	for i, sb := range s {
+		tb := t[i]
+		if sb == tb {
+			continue
+		}
+		if ('a' <= sb && sb <= 'z') || ('A' <= sb && sb <= 'Z') {
+			if sb&caseMask != tb&caseMask {
+				return false
+			}
+		} else {
+			return false
+		}
+	}
+	return true
+}
+
+// simpleLetterEqualFold is a specialization of bytes.EqualFold for
+// use when s is all ASCII letters (no underscores, etc) and also
+// doesn't contain 'k', 'K', 's', or 'S'.
+// See comments on foldFunc.
+func simpleLetterEqualFold(s, t []byte) bool {
+	if len(s) != len(t) {
+		return false
+	}
+	for i, b := range s {
+		if b&caseMask != t[i]&caseMask {
+			return false
+		}
+	}
+	return true
+}
diff --git a/libgo/go/encoding/json/fold_test.go b/libgo/go/encoding/json/fold_test.go
new file mode 100644
index 0000000..9fb9464
--- /dev/null
+++ b/libgo/go/encoding/json/fold_test.go
@@ -0,0 +1,116 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+	"unicode/utf8"
+)
+
+var foldTests = []struct {
+	fn   func(s, t []byte) bool
+	s, t string
+	want bool
+}{
+	{equalFoldRight, "", "", true},
+	{equalFoldRight, "a", "a", true},
+	{equalFoldRight, "", "a", false},
+	{equalFoldRight, "a", "", false},
+	{equalFoldRight, "a", "A", true},
+	{equalFoldRight, "AB", "ab", true},
+	{equalFoldRight, "AB", "ac", false},
+	{equalFoldRight, "sbkKc", "ſbKKc", true},
+	{equalFoldRight, "SbKkc", "ſbKKc", true},
+	{equalFoldRight, "SbKkc", "ſbKK", false},
+	{equalFoldRight, "e", "é", false},
+	{equalFoldRight, "s", "S", true},
+
+	{simpleLetterEqualFold, "", "", true},
+	{simpleLetterEqualFold, "abc", "abc", true},
+	{simpleLetterEqualFold, "abc", "ABC", true},
+	{simpleLetterEqualFold, "abc", "ABCD", false},
+	{simpleLetterEqualFold, "abc", "xxx", false},
+
+	{asciiEqualFold, "a_B", "A_b", true},
+	{asciiEqualFold, "aa@", "aa`", false}, // verify 0x40 and 0x60 aren't case-equivalent
+}
+
+func TestFold(t *testing.T) {
+	for i, tt := range foldTests {
+		if got := tt.fn([]byte(tt.s), []byte(tt.t)); got != tt.want {
+			t.Errorf("%d. %q, %q = %v; want %v", i, tt.s, tt.t, got, tt.want)
+		}
+		truth := strings.EqualFold(tt.s, tt.t)
+		if truth != tt.want {
+			t.Errorf("strings.EqualFold doesn't agree with case %d", i)
+		}
+	}
+}
+
+func TestFoldAgainstUnicode(t *testing.T) {
+	const bufSize = 5
+	buf1 := make([]byte, 0, bufSize)
+	buf2 := make([]byte, 0, bufSize)
+	var runes []rune
+	for i := 0x20; i <= 0x7f; i++ {
+		runes = append(runes, rune(i))
+	}
+	runes = append(runes, kelvin, smallLongEss)
+
+	funcs := []struct {
+		name   string
+		fold   func(s, t []byte) bool
+		letter bool // must be ASCII letter
+		simple bool // must be simple ASCII letter (not 'S' or 'K')
+	}{
+		{
+			name: "equalFoldRight",
+			fold: equalFoldRight,
+		},
+		{
+			name:   "asciiEqualFold",
+			fold:   asciiEqualFold,
+			simple: true,
+		},
+		{
+			name:   "simpleLetterEqualFold",
+			fold:   simpleLetterEqualFold,
+			simple: true,
+			letter: true,
+		},
+	}
+
+	for _, ff := range funcs {
+		for _, r := range runes {
+			if r >= utf8.RuneSelf {
+				continue
+			}
+			if ff.letter && !isASCIILetter(byte(r)) {
+				continue
+			}
+			if ff.simple && (r == 's' || r == 'S' || r == 'k' || r == 'K') {
+				continue
+			}
+			for _, r2 := range runes {
+				buf1 := append(buf1[:0], 'x')
+				buf2 := append(buf2[:0], 'x')
+				buf1 = buf1[:1+utf8.EncodeRune(buf1[1:bufSize], r)]
+				buf2 = buf2[:1+utf8.EncodeRune(buf2[1:bufSize], r2)]
+				buf1 = append(buf1, 'x')
+				buf2 = append(buf2, 'x')
+				want := bytes.EqualFold(buf1, buf2)
+				if got := ff.fold(buf1, buf2); got != want {
+					t.Errorf("%s(%q, %q) = %v; want %v", ff.name, buf1, buf2, got, want)
+				}
+			}
+		}
+	}
+}
+
+func isASCIILetter(b byte) bool {
+	return ('A' <= b && b <= 'Z') || ('a' <= b && b <= 'z')
+}
diff --git a/libgo/go/encoding/json/stream.go b/libgo/go/encoding/json/stream.go
index 1928aba..e8d6bd4 100644
--- a/libgo/go/encoding/json/stream.go
+++ b/libgo/go/encoding/json/stream.go
@@ -173,7 +173,7 @@ func (enc *Encoder) Encode(v interface{}) error {
 	if _, err = enc.w.Write(e.Bytes()); err != nil {
 		enc.err = err
 	}
-	putEncodeState(e)
+	encodeStatePool.Put(e)
 	return err
 }