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diff --git a/vendor/golang.org/x/text/encoding/unicode/utf32/utf32.go b/vendor/golang.org/x/text/encoding/unicode/utf32/utf32.go
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+// 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
+}