Update vendor

1 files changed, 296 insertions, 0 deletions

diff --git a/vendor/golang.org/x/text/encoding/unicode/utf32/utf32.go b/vendor/golang.org/x/text/encoding/unicode/utf32/utf32.go
new file mode 100644
index 00000000..48b21521
--- /dev/null
+++ b/vendor/golang.org/x/text/encoding/unicode/utf32/utf32.go
@@ -0,0 +1,296 @@
+// Copyright 2016 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 utf32 provides the UTF-32 Unicode encoding.
+//
+// Please note that support for UTF-32 is discouraged as it is a rare and
+// inefficient encoding, unfit for use as an interchange format. For use
+// on the web, the W3C strongly discourages its use
+// (https://www.w3.org/TR/html5/document-metadata.html#charset)
+// while WHATWG directly prohibits supporting it
+// (https://html.spec.whatwg.org/multipage/syntax.html#character-encodings).
+package utf32 // import "golang.org/x/text/encoding/unicode/utf32"
+
+import (
+	"errors"
+	"unicode/utf8"
+
+	"golang.org/x/text/encoding"
+	"golang.org/x/text/encoding/internal/identifier"
+	"golang.org/x/text/transform"
+)
+
+// All lists a configuration for each IANA-defined UTF-32 variant.
+var All = []encoding.Encoding{
+	UTF32(BigEndian, UseBOM),
+	UTF32(BigEndian, IgnoreBOM),
+	UTF32(LittleEndian, IgnoreBOM),
+}
+
+// ErrMissingBOM means that decoding UTF-32 input with ExpectBOM did not
+// find a starting byte order mark.
+var ErrMissingBOM = errors.New("encoding: missing byte order mark")
+
+// UTF32 returns a UTF-32 Encoding for the given default endianness and
+// byte order mark (BOM) policy.
+//
+// When decoding from UTF-32 to UTF-8, if the BOMPolicy is IgnoreBOM then
+// neither BOMs U+FEFF nor ill-formed code units 0xFFFE0000 in the input
+// stream will affect the endianness used for decoding. Instead BOMs will
+// be output as their standard UTF-8 encoding "\xef\xbb\xbf" while
+// 0xFFFE0000 code units will be output as "\xef\xbf\xbd", the standard
+// UTF-8 encoding for the Unicode replacement character. If the BOMPolicy
+// is UseBOM or ExpectBOM a starting BOM is not written to the UTF-8
+// output. Instead, it overrides the default endianness e for the remainder
+// of the transformation. Any subsequent BOMs U+FEFF or ill-formed code
+// units 0xFFFE0000 will not affect the endianness used, and will instead
+// be output as their standard UTF-8 (replacement) encodings. For UseBOM,
+// if there is no starting BOM, it will proceed with the default
+// Endianness. For ExpectBOM, in that case, the transformation will return
+// early with an ErrMissingBOM error.
+//
+// When encoding from UTF-8 to UTF-32, a BOM will be inserted at the start
+// of the output if the BOMPolicy is UseBOM or ExpectBOM. Otherwise, a BOM
+// will not be inserted. The UTF-8 input does not need to contain a BOM.
+//
+// There is no concept of a 'native' endianness. If the UTF-32 data is
+// produced and consumed in a greater context that implies a certain
+// endianness, use IgnoreBOM. Otherwise, use ExpectBOM and always produce
+// and consume a BOM.
+//
+// In the language of http://www.unicode.org/faq/utf_bom.html#bom10,
+// IgnoreBOM corresponds to "Where the precise type of the data stream is
+// known... the BOM should not be used" and ExpectBOM corresponds to "A
+// particular protocol... may require use of the BOM".
+func UTF32(e Endianness, b BOMPolicy) encoding.Encoding {
+	return utf32Encoding{config{e, b}, mibValue[e][b&bomMask]}
+}
+
+// mibValue maps Endianness and BOMPolicy settings to MIB constants for UTF-32.
+// Note that some configurations map to the same MIB identifier.
+var mibValue = map[Endianness][numBOMValues]identifier.MIB{
+	BigEndian: [numBOMValues]identifier.MIB{
+		IgnoreBOM: identifier.UTF32BE,
+		UseBOM:    identifier.UTF32,
+	},
+	LittleEndian: [numBOMValues]identifier.MIB{
+		IgnoreBOM: identifier.UTF32LE,
+		UseBOM:    identifier.UTF32,
+	},
+	// ExpectBOM is not widely used and has no valid MIB identifier.
+}
+
+// BOMPolicy is a UTF-32 encodings's byte order mark policy.
+type BOMPolicy uint8
+
+const (
+	writeBOM   BOMPolicy = 0x01
+	acceptBOM  BOMPolicy = 0x02
+	requireBOM BOMPolicy = 0x04
+	bomMask    BOMPolicy = 0x07
+
+	// HACK: numBOMValues == 8 triggers a bug in the 1.4 compiler (cannot have a
+	// map of an array of length 8 of a type that is also used as a key or value
+	// in another map). See golang.org/issue/11354.
+	// TODO: consider changing this value back to 8 if the use of 1.4.* has
+	// been minimized.
+	numBOMValues = 8 + 1
+
+	// IgnoreBOM means to ignore any byte order marks.
+	IgnoreBOM BOMPolicy = 0
+	// Unicode-compliant interpretation for UTF-32BE/LE.
+
+	// UseBOM means that the UTF-32 form may start with a byte order mark,
+	// which will be used to override the default encoding.
+	UseBOM BOMPolicy = writeBOM | acceptBOM
+	// Unicode-compliant interpretation for UTF-32.
+
+	// ExpectBOM means that the UTF-32 form must start with a byte order mark,
+	// which will be used to override the default encoding.
+	ExpectBOM BOMPolicy = writeBOM | acceptBOM | requireBOM
+	// Consistent with BOMPolicy definition in golang.org/x/text/encoding/unicode
+)
+
+// Endianness is a UTF-32 encoding's default endianness.
+type Endianness bool
+
+const (
+	// BigEndian is UTF-32BE.
+	BigEndian Endianness = false
+	// LittleEndian is UTF-32LE.
+	LittleEndian Endianness = true
+)
+
+type config struct {
+	endianness Endianness
+	bomPolicy  BOMPolicy
+}
+
+type utf32Encoding struct {
+	config
+	mib identifier.MIB
+}
+
+func (u utf32Encoding) NewDecoder() *encoding.Decoder {
+	return &encoding.Decoder{Transformer: &utf32Decoder{
+		initial: u.config,
+		current: u.config,
+	}}
+}
+
+func (u utf32Encoding) NewEncoder() *encoding.Encoder {
+	return &encoding.Encoder{Transformer: &utf32Encoder{
+		endianness:       u.endianness,
+		initialBOMPolicy: u.bomPolicy,
+		currentBOMPolicy: u.bomPolicy,
+	}}
+}
+
+func (u utf32Encoding) ID() (mib identifier.MIB, other string) {
+	return u.mib, ""
+}
+
+func (u utf32Encoding) String() string {
+	e, b := "B", ""
+	if u.endianness == LittleEndian {
+		e = "L"
+	}
+	switch u.bomPolicy {
+	case ExpectBOM:
+		b = "Expect"
+	case UseBOM:
+		b = "Use"
+	case IgnoreBOM:
+		b = "Ignore"
+	}
+	return "UTF-32" + e + "E (" + b + " BOM)"
+}
+
+type utf32Decoder struct {
+	initial config
+	current config
+}
+
+func (u *utf32Decoder) Reset() {
+	u.current = u.initial
+}
+
+func (u *utf32Decoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	if len(src) == 0 {
+		if atEOF && u.current.bomPolicy&requireBOM != 0 {
+			return 0, 0, ErrMissingBOM
+		}
+		return 0, 0, nil
+	}
+	if u.current.bomPolicy&acceptBOM != 0 {
+		if len(src) < 4 {
+			return 0, 0, transform.ErrShortSrc
+		}
+		switch {
+		case src[0] == 0x00 && src[1] == 0x00 && src[2] == 0xfe && src[3] == 0xff:
+			u.current.endianness = BigEndian
+			nSrc = 4
+		case src[0] == 0xff && src[1] == 0xfe && src[2] == 0x00 && src[3] == 0x00:
+			u.current.endianness = LittleEndian
+			nSrc = 4
+		default:
+			if u.current.bomPolicy&requireBOM != 0 {
+				return 0, 0, ErrMissingBOM
+			}
+		}
+		u.current.bomPolicy = IgnoreBOM
+	}
+
+	var r rune
+	var dSize, sSize int
+	for nSrc < len(src) {
+		if nSrc+3 < len(src) {
+			x := uint32(src[nSrc+0])<<24 | uint32(src[nSrc+1])<<16 |
+				uint32(src[nSrc+2])<<8 | uint32(src[nSrc+3])
+			if u.current.endianness == LittleEndian {
+				x = x>>24 | (x >> 8 & 0x0000FF00) | (x << 8 & 0x00FF0000) | x<<24
+			}
+			r, sSize = rune(x), 4
+			if dSize = utf8.RuneLen(r); dSize < 0 {
+				r, dSize = utf8.RuneError, 3
+			}
+		} else if atEOF {
+			// 1..3 trailing bytes.
+			r, dSize, sSize = utf8.RuneError, 3, len(src)-nSrc
+		} else {
+			err = transform.ErrShortSrc
+			break
+		}
+		if nDst+dSize > len(dst) {
+			err = transform.ErrShortDst
+			break
+		}
+		nDst += utf8.EncodeRune(dst[nDst:], r)
+		nSrc += sSize
+	}
+	return nDst, nSrc, err
+}
+
+type utf32Encoder struct {
+	endianness       Endianness
+	initialBOMPolicy BOMPolicy
+	currentBOMPolicy BOMPolicy
+}
+
+func (u *utf32Encoder) Reset() {
+	u.currentBOMPolicy = u.initialBOMPolicy
+}
+
+func (u *utf32Encoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	if u.currentBOMPolicy&writeBOM != 0 {
+		if len(dst) < 4 {
+			return 0, 0, transform.ErrShortDst
+		}
+		dst[0], dst[1], dst[2], dst[3] = 0x00, 0x00, 0xfe, 0xff
+		u.currentBOMPolicy = IgnoreBOM
+		nDst = 4
+	}
+
+	r, size := rune(0), 0
+	for nSrc < len(src) {
+		r = rune(src[nSrc])
+
+		// Decode a 1-byte rune.
+		if r < utf8.RuneSelf {
+			size = 1
+
+		} else {
+			// Decode a multi-byte rune.
+			r, size = utf8.DecodeRune(src[nSrc:])
+			if size == 1 {
+				// All valid runes of size 1 (those below utf8.RuneSelf) were
+				// handled above. We have invalid UTF-8 or we haven't seen the
+				// full character yet.
+				if !atEOF && !utf8.FullRune(src[nSrc:]) {
+					err = transform.ErrShortSrc
+					break
+				}
+			}
+		}
+
+		if nDst+4 > len(dst) {
+			err = transform.ErrShortDst
+			break
+		}
+
+		dst[nDst+0] = uint8(r >> 24)
+		dst[nDst+1] = uint8(r >> 16)
+		dst[nDst+2] = uint8(r >> 8)
+		dst[nDst+3] = uint8(r)
+		nDst += 4
+		nSrc += size
+	}
+
+	if u.endianness == LittleEndian {
+		for i := 0; i < nDst; i += 4 {
+			dst[i], dst[i+1], dst[i+2], dst[i+3] = dst[i+3], dst[i+2], dst[i+1], dst[i]
+		}
+	}
+	return nDst, nSrc, err
+}