libgo: update to go1.9

    
    Reviewed-on: https://go-review.googlesource.com/63753

From-SVN: r252767

2 files changed, 73 insertions, 29 deletions

diff --git a/libgo/go/encoding/base64/base64.go b/libgo/go/encoding/base64/base64.go
index d2efad4..b208f9e 100644
--- a/libgo/go/encoding/base64/base64.go
+++ b/libgo/go/encoding/base64/base64.go
@@ -35,13 +35,19 @@ const encodeStd = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz012345678
 const encodeURL = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"
 
 // NewEncoding returns a new padded Encoding defined by the given alphabet,
-// which must be a 64-byte string.
+// which must be a 64-byte string that does not contain the padding character
+// or CR / LF ('\r', '\n').
 // The resulting Encoding uses the default padding character ('='),
 // which may be changed or disabled via WithPadding.
 func NewEncoding(encoder string) *Encoding {
 	if len(encoder) != 64 {
 		panic("encoding alphabet is not 64-bytes long")
 	}
+	for i := 0; i < len(encoder); i++ {
+		if encoder[i] == '\n' || encoder[i] == '\r' {
+			panic("encoding alphabet contains newline character")
+		}
+	}
 
 	e := new(Encoding)
 	e.padChar = StdPadding
@@ -58,7 +64,20 @@ func NewEncoding(encoder string) *Encoding {
 
 // WithPadding creates a new encoding identical to enc except
 // with a specified padding character, or NoPadding to disable padding.
+// The padding character must not be '\r' or '\n', must not
+// be contained in the encoding's alphabet and must be a rune equal or
+// below '\xff'.
 func (enc Encoding) WithPadding(padding rune) *Encoding {
+	if padding == '\r' || padding == '\n' || padding > 0xff {
+		panic("invalid padding")
+	}
+
+	for i := 0; i < len(enc.encode); i++ {
+		if rune(enc.encode[i]) == padding {
+			panic("padding contained in alphabet")
+		}
+	}
+
 	enc.padChar = padding
 	return &enc
 }
@@ -256,19 +275,17 @@ func (e CorruptInputError) Error() string {
 func (enc *Encoding) decode(dst, src []byte) (n int, end bool, err error) {
 	si := 0
 
-	// skip over newlines
-	for si < len(src) && (src[si] == '\n' || src[si] == '\r') {
-		si++
-	}
-
 	for si < len(src) && !end {
 		// Decode quantum using the base64 alphabet
 		var dbuf [4]byte
 		dinc, dlen := 3, 4
 
-		for j := range dbuf {
+		for j := 0; j < len(dbuf); j++ {
 			if len(src) == si {
-				if enc.padChar != NoPadding || j < 2 {
+				switch {
+				case j == 0:
+					return n, false, nil
+				case j == 1, enc.padChar != NoPadding:
 					return n, false, CorruptInputError(si - j)
 				}
 				dinc, dlen, end = j-1, j, true
@@ -277,11 +294,17 @@ func (enc *Encoding) decode(dst, src []byte) (n int, end bool, err error) {
 			in := src[si]
 
 			si++
-			// skip over newlines
-			for si < len(src) && (src[si] == '\n' || src[si] == '\r') {
-				si++
+
+			out := enc.decodeMap[in]
+			if out != 0xFF {
+				dbuf[j] = out
+				continue
 			}
 
+			if in == '\n' || in == '\r' {
+				j--
+				continue
+			}
 			if rune(in) == enc.padChar {
 				// We've reached the end and there's padding
 				switch j {
@@ -290,6 +313,10 @@ func (enc *Encoding) decode(dst, src []byte) (n int, end bool, err error) {
 					return n, false, CorruptInputError(si - 1)
 				case 2:
 					// "==" is expected, the first "=" is already consumed.
+					// skip over newlines
+					for si < len(src) && (src[si] == '\n' || src[si] == '\r') {
+						si++
+					}
 					if si == len(src) {
 						// not enough padding
 						return n, false, CorruptInputError(len(src))
@@ -300,10 +327,10 @@ func (enc *Encoding) decode(dst, src []byte) (n int, end bool, err error) {
 					}
 
 					si++
-					// skip over newlines
-					for si < len(src) && (src[si] == '\n' || src[si] == '\r') {
-						si++
-					}
+				}
+				// skip over newlines
+				for si < len(src) && (src[si] == '\n' || src[si] == '\r') {
+					si++
 				}
 				if si < len(src) {
 					// trailing garbage
@@ -312,10 +339,7 @@ func (enc *Encoding) decode(dst, src []byte) (n int, end bool, err error) {
 				dinc, dlen, end = 3, j, true
 				break
 			}
-			dbuf[j] = enc.decodeMap[in]
-			if dbuf[j] == 0xFF {
-				return n, false, CorruptInputError(si - 1)
-			}
+			return n, false, CorruptInputError(si - 1)
 		}
 
 		// Convert 4x 6bit source bytes into 3 bytes
diff --git a/libgo/go/encoding/base64/base64_test.go b/libgo/go/encoding/base64/base64_test.go
index e2e1d59..05011fb 100644
--- a/libgo/go/encoding/base64/base64_test.go
+++ b/libgo/go/encoding/base64/base64_test.go
@@ -7,6 +7,7 @@ package base64
 import (
 	"bytes"
 	"errors"
+	"fmt"
 	"io"
 	"io/ioutil"
 	"reflect"
@@ -63,7 +64,7 @@ func rawRef(ref string) string {
 }
 
 // Both URL and unpadding conversions
-func rawUrlRef(ref string) string {
+func rawURLRef(ref string) string {
 	return rawRef(urlRef(ref))
 }
 
@@ -83,12 +84,12 @@ var encodingTests = []encodingTest{
 	{StdEncoding, stdRef},
 	{URLEncoding, urlRef},
 	{RawStdEncoding, rawRef},
-	{RawURLEncoding, rawUrlRef},
+	{RawURLEncoding, rawURLRef},
 	{funnyEncoding, funnyRef},
 	{StdEncoding.Strict(), stdRef},
 	{URLEncoding.Strict(), urlRef},
 	{RawStdEncoding.Strict(), rawRef},
-	{RawURLEncoding.Strict(), rawUrlRef},
+	{RawURLEncoding.Strict(), rawURLRef},
 	{funnyEncoding.Strict(), funnyRef},
 }
 
@@ -98,6 +99,7 @@ var bigtest = testpair{
 }
 
 func testEqual(t *testing.T, msg string, args ...interface{}) bool {
+	t.Helper()
 	if args[len(args)-2] != args[len(args)-1] {
 		t.Errorf(msg, args...)
 		return false
@@ -187,11 +189,15 @@ func TestDecoderBuffering(t *testing.T) {
 		decoder := NewDecoder(StdEncoding, strings.NewReader(bigtest.encoded))
 		buf := make([]byte, len(bigtest.decoded)+12)
 		var total int
-		for total = 0; total < len(bigtest.decoded); {
-			n, err := decoder.Read(buf[total : total+bs])
-			testEqual(t, "Read from %q at pos %d = %d, %v, want _, %v", bigtest.encoded, total, n, err, error(nil))
+		var n int
+		var err error
+		for total = 0; total < len(bigtest.decoded) && err == nil; {
+			n, err = decoder.Read(buf[total : total+bs])
 			total += n
 		}
+		if err != nil && err != io.EOF {
+			t.Errorf("Read from %q at pos %d = %d, unexpected error %v", bigtest.encoded, total, n, err)
+		}
 		testEqual(t, "Decoding/%d of %q = %q, want %q", bs, bigtest.encoded, string(buf[0:total]), bigtest.decoded)
 	}
 }
@@ -202,6 +208,9 @@ func TestDecodeCorrupt(t *testing.T) {
 		offset int // -1 means no corruption.
 	}{
 		{"", -1},
+		{"\n", -1},
+		{"AAA=\n", -1},
+		{"AAAA\n", -1},
 		{"!!!!", 0},
 		{"====", 0},
 		{"x===", 1},
@@ -220,6 +229,8 @@ func TestDecodeCorrupt(t *testing.T) {
 		{"AAAA", -1},
 		{"AAAAAA=", 7},
 		{"YWJjZA=====", 8},
+		{"A!\n", 1},
+		{"A=\n", 1},
 	}
 	for _, tc := range testCases {
 		dbuf := make([]byte, StdEncoding.DecodedLen(len(tc.input)))
@@ -466,10 +477,19 @@ func BenchmarkEncodeToString(b *testing.B) {
 }
 
 func BenchmarkDecodeString(b *testing.B) {
-	data := StdEncoding.EncodeToString(make([]byte, 8192))
-	b.SetBytes(int64(len(data)))
-	for i := 0; i < b.N; i++ {
-		StdEncoding.DecodeString(data)
+	sizes := []int{2, 4, 8, 64, 8192}
+	benchFunc := func(b *testing.B, benchSize int) {
+		data := StdEncoding.EncodeToString(make([]byte, benchSize))
+		b.SetBytes(int64(len(data)))
+		b.ResetTimer()
+		for i := 0; i < b.N; i++ {
+			StdEncoding.DecodeString(data)
+		}
+	}
+	for _, size := range sizes {
+		b.Run(fmt.Sprintf("%d", size), func(b *testing.B) {
+			benchFunc(b, size)
+		})
 	}
 }