1 files changed, 709 insertions, 0 deletions

diff --git a/vendor/golang.org/x/text/transform/transform.go b/vendor/golang.org/x/text/transform/transform.go
new file mode 100644
index 0000000..48ec64b
--- /dev/null
+++ b/vendor/golang.org/x/text/transform/transform.go
@@ -0,0 +1,709 @@
+// 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 transform provides reader and writer wrappers that transform the
+// bytes passing through as well as various transformations. Example
+// transformations provided by other packages include normalization and
+// conversion between character sets.
+package transform // import "golang.org/x/text/transform"
+
+import (
+        "bytes"
+        "errors"
+        "io"
+        "unicode/utf8"
+)
+
+var (
+        // ErrShortDst means that the destination buffer was too short to
+        // receive all of the transformed bytes.
+        ErrShortDst = errors.New("transform: short destination buffer")
+
+        // ErrShortSrc means that the source buffer has insufficient data to
+        // complete the transformation.
+        ErrShortSrc = errors.New("transform: short source buffer")
+
+        // ErrEndOfSpan means that the input and output (the transformed input)
+        // are not identical.
+        ErrEndOfSpan = errors.New("transform: input and output are not identical")
+
+        // errInconsistentByteCount means that Transform returned success (nil
+        // error) but also returned nSrc inconsistent with the src argument.
+        errInconsistentByteCount = errors.New("transform: inconsistent byte count returned")
+
+        // errShortInternal means that an internal buffer is not large enough
+        // to make progress and the Transform operation must be aborted.
+        errShortInternal = errors.New("transform: short internal buffer")
+)
+
+// Transformer transforms bytes.
+type Transformer interface {
+        // Transform writes to dst the transformed bytes read from src, and
+        // returns the number of dst bytes written and src bytes read. The
+        // atEOF argument tells whether src represents the last bytes of the
+        // input.
+        //
+        // Callers should always process the nDst bytes produced and account
+        // for the nSrc bytes consumed before considering the error err.
+        //
+        // A nil error means that all of the transformed bytes (whether freshly
+        // transformed from src or left over from previous Transform calls)
+        // were written to dst. A nil error can be returned regardless of
+        // whether atEOF is true. If err is nil then nSrc must equal len(src);
+        // the converse is not necessarily true.
+        //
+        // ErrShortDst means that dst was too short to receive all of the
+        // transformed bytes. ErrShortSrc means that src had insufficient data
+        // to complete the transformation. If both conditions apply, then
+        // either error may be returned. Other than the error conditions listed
+        // here, implementations are free to report other errors that arise.
+        Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error)
+
+        // Reset resets the state and allows a Transformer to be reused.
+        Reset()
+}
+
+// SpanningTransformer extends the Transformer interface with a Span method
+// that determines how much of the input already conforms to the Transformer.
+type SpanningTransformer interface {
+        Transformer
+
+        // Span returns a position in src such that transforming src[:n] results in
+        // identical output src[:n] for these bytes. It does not necessarily return
+        // the largest such n. The atEOF argument tells whether src represents the
+        // last bytes of the input.
+        //
+        // Callers should always account for the n bytes consumed before
+        // considering the error err.
+        //
+        // A nil error means that all input bytes are known to be identical to the
+        // output produced by the Transformer. A nil error can be returned
+        // regardless of whether atEOF is true. If err is nil, then n must
+        // equal len(src); the converse is not necessarily true.
+        //
+        // ErrEndOfSpan means that the Transformer output may differ from the
+        // input after n bytes. Note that n may be len(src), meaning that the output
+        // would contain additional bytes after otherwise identical output.
+        // ErrShortSrc means that src had insufficient data to determine whether the
+        // remaining bytes would change. Other than the error conditions listed
+        // here, implementations are free to report other errors that arise.
+        //
+        // Calling Span can modify the Transformer state as a side effect. In
+        // effect, it does the transformation just as calling Transform would, only
+        // without copying to a destination buffer and only up to a point it can
+        // determine the input and output bytes are the same. This is obviously more
+        // limited than calling Transform, but can be more efficient in terms of
+        // copying and allocating buffers. Calls to Span and Transform may be
+        // interleaved.
+        Span(src []byte, atEOF bool) (n int, err error)
+}
+
+// NopResetter can be embedded by implementations of Transformer to add a nop
+// Reset method.
+type NopResetter struct{}
+
+// Reset implements the Reset method of the Transformer interface.
+func (NopResetter) Reset() {}
+
+// Reader wraps another io.Reader by transforming the bytes read.
+type Reader struct {
+        r   io.Reader
+        t   Transformer
+        err error
+
+        // dst[dst0:dst1] contains bytes that have been transformed by t but
+        // not yet copied out via Read.
+        dst        []byte
+        dst0, dst1 int
+
+        // src[src0:src1] contains bytes that have been read from r but not
+        // yet transformed through t.
+        src        []byte
+        src0, src1 int
+
+        // transformComplete is whether the transformation is complete,
+        // regardless of whether or not it was successful.
+        transformComplete bool
+}
+
+const defaultBufSize = 4096
+
+// NewReader returns a new Reader that wraps r by transforming the bytes read
+// via t. It calls Reset on t.
+func NewReader(r io.Reader, t Transformer) *Reader {
+        t.Reset()
+        return &Reader{
+                r:   r,
+                t:   t,
+                dst: make([]byte, defaultBufSize),
+                src: make([]byte, defaultBufSize),
+        }
+}
+
+// Read implements the io.Reader interface.
+func (r *Reader) Read(p []byte) (int, error) {
+        n, err := 0, error(nil)
+        for {
+                // Copy out any transformed bytes and return the final error if we are done.
+                if r.dst0 != r.dst1 {
+                        n = copy(p, r.dst[r.dst0:r.dst1])
+                        r.dst0 += n
+                        if r.dst0 == r.dst1 && r.transformComplete {
+                                return n, r.err
+                        }
+                        return n, nil
+                } else if r.transformComplete {
+                        return 0, r.err
+                }
+
+                // Try to transform some source bytes, or to flush the transformer if we
+                // are out of source bytes. We do this even if r.r.Read returned an error.
+                // As the io.Reader documentation says, "process the n > 0 bytes returned
+                // before considering the error".
+                if r.src0 != r.src1 || r.err != nil {
+                        r.dst0 = 0
+                        r.dst1, n, err = r.t.Transform(r.dst, r.src[r.src0:r.src1], r.err == io.EOF)
+                        r.src0 += n
+
+                        switch {
+                        case err == nil:
+                                if r.src0 != r.src1 {
+                                        r.err = errInconsistentByteCount
+                                }
+                                // The Transform call was successful; we are complete if we
+                                // cannot read more bytes into src.
+                                r.transformComplete = r.err != nil
+                                continue
+                        case err == ErrShortDst && (r.dst1 != 0 || n != 0):
+                                // Make room in dst by copying out, and try again.
+                                continue
+                        case err == ErrShortSrc && r.src1-r.src0 != len(r.src) && r.err == nil:
+                                // Read more bytes into src via the code below, and try again.
+                        default:
+                                r.transformComplete = true
+                                // The reader error (r.err) takes precedence over the
+                                // transformer error (err) unless r.err is nil or io.EOF.
+                                if r.err == nil || r.err == io.EOF {
+                                        r.err = err
+                                }
+                                continue
+                        }
+                }
+
+                // Move any untransformed source bytes to the start of the buffer
+                // and read more bytes.
+                if r.src0 != 0 {
+                        r.src0, r.src1 = 0, copy(r.src, r.src[r.src0:r.src1])
+                }
+                n, r.err = r.r.Read(r.src[r.src1:])
+                r.src1 += n
+        }
+}
+
+// TODO: implement ReadByte (and ReadRune??).
+
+// Writer wraps another io.Writer by transforming the bytes read.
+// The user needs to call Close to flush unwritten bytes that may
+// be buffered.
+type Writer struct {
+        w   io.Writer
+        t   Transformer
+        dst []byte
+
+        // src[:n] contains bytes that have not yet passed through t.
+        src []byte
+        n   int
+}
+
+// NewWriter returns a new Writer that wraps w by transforming the bytes written
+// via t. It calls Reset on t.
+func NewWriter(w io.Writer, t Transformer) *Writer {
+        t.Reset()
+        return &Writer{
+                w:   w,
+                t:   t,
+                dst: make([]byte, defaultBufSize),
+                src: make([]byte, defaultBufSize),
+        }
+}
+
+// Write implements the io.Writer interface. If there are not enough
+// bytes available to complete a Transform, the bytes will be buffered
+// for the next write. Call Close to convert the remaining bytes.
+func (w *Writer) Write(data []byte) (n int, err error) {
+        src := data
+        if w.n > 0 {
+                // Append bytes from data to the last remainder.
+                // TODO: limit the amount copied on first try.
+                n = copy(w.src[w.n:], data)
+                w.n += n
+                src = w.src[:w.n]
+        }
+        for {
+                nDst, nSrc, err := w.t.Transform(w.dst, src, false)
+                if _, werr := w.w.Write(w.dst[:nDst]); werr != nil {
+                        return n, werr
+                }
+                src = src[nSrc:]
+                if w.n == 0 {
+                        n += nSrc
+                } else if len(src) <= n {
+                        // Enough bytes from w.src have been consumed. We make src point
+                        // to data instead to reduce the copying.
+                        w.n = 0
+                        n -= len(src)
+                        src = data[n:]
+                        if n < len(data) && (err == nil || err == ErrShortSrc) {
+                                continue
+                        }
+                }
+                switch err {
+                case ErrShortDst:
+                        // This error is okay as long as we are making progress.
+                        if nDst > 0 || nSrc > 0 {
+                                continue
+                        }
+                case ErrShortSrc:
+                        if len(src) < len(w.src) {
+                                m := copy(w.src, src)
+                                // If w.n > 0, bytes from data were already copied to w.src and n
+                                // was already set to the number of bytes consumed.
+                                if w.n == 0 {
+                                        n += m
+                                }
+                                w.n = m
+                                err = nil
+                        } else if nDst > 0 || nSrc > 0 {
+                                // Not enough buffer to store the remainder. Keep processing as
+                                // long as there is progress. Without this case, transforms that
+                                // require a lookahead larger than the buffer may result in an
+                                // error. This is not something one may expect to be common in
+                                // practice, but it may occur when buffers are set to small
+                                // sizes during testing.
+                                continue
+                        }
+                case nil:
+                        if w.n > 0 {
+                                err = errInconsistentByteCount
+                        }
+                }
+                return n, err
+        }
+}
+
+// Close implements the io.Closer interface.
+func (w *Writer) Close() error {
+        src := w.src[:w.n]
+        for {
+                nDst, nSrc, err := w.t.Transform(w.dst, src, true)
+                if _, werr := w.w.Write(w.dst[:nDst]); werr != nil {
+                        return werr
+                }
+                if err != ErrShortDst {
+                        return err
+                }
+                src = src[nSrc:]
+        }
+}
+
+type nop struct{ NopResetter }
+
+func (nop) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+        n := copy(dst, src)
+        if n < len(src) {
+                err = ErrShortDst
+        }
+        return n, n, err
+}
+
+func (nop) Span(src []byte, atEOF bool) (n int, err error) {
+        return len(src), nil
+}
+
+type discard struct{ NopResetter }
+
+func (discard) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+        return 0, len(src), nil
+}
+
+var (
+        // Discard is a Transformer for which all Transform calls succeed
+        // by consuming all bytes and writing nothing.
+        Discard Transformer = discard{}
+
+        // Nop is a SpanningTransformer that copies src to dst.
+        Nop SpanningTransformer = nop{}
+)
+
+// chain is a sequence of links. A chain with N Transformers has N+1 links and
+// N+1 buffers. Of those N+1 buffers, the first and last are the src and dst
+// buffers given to chain.Transform and the middle N-1 buffers are intermediate
+// buffers owned by the chain. The i'th link transforms bytes from the i'th
+// buffer chain.link[i].b at read offset chain.link[i].p to the i+1'th buffer
+// chain.link[i+1].b at write offset chain.link[i+1].n, for i in [0, N).
+type chain struct {
+        link []link
+        err  error
+        // errStart is the index at which the error occurred plus 1. Processing
+        // errStart at this level at the next call to Transform. As long as
+        // errStart > 0, chain will not consume any more source bytes.
+        errStart int
+}
+
+func (c *chain) fatalError(errIndex int, err error) {
+        if i := errIndex + 1; i > c.errStart {
+                c.errStart = i
+                c.err = err
+        }
+}
+
+type link struct {
+        t Transformer
+        // b[p:n] holds the bytes to be transformed by t.
+        b []byte
+        p int
+        n int
+}
+
+func (l *link) src() []byte {
+        return l.b[l.p:l.n]
+}
+
+func (l *link) dst() []byte {
+        return l.b[l.n:]
+}
+
+// Chain returns a Transformer that applies t in sequence.
+func Chain(t ...Transformer) Transformer {
+        if len(t) == 0 {
+                return nop{}
+        }
+        c := &chain{link: make([]link, len(t)+1)}
+        for i, tt := range t {
+                c.link[i].t = tt
+        }
+        // Allocate intermediate buffers.
+        b := make([][defaultBufSize]byte, len(t)-1)
+        for i := range b {
+                c.link[i+1].b = b[i][:]
+        }
+        return c
+}
+
+// Reset resets the state of Chain. It calls Reset on all the Transformers.
+func (c *chain) Reset() {
+        for i, l := range c.link {
+                if l.t != nil {
+                        l.t.Reset()
+                }
+                c.link[i].p, c.link[i].n = 0, 0
+        }
+}
+
+// TODO: make chain use Span (is going to be fun to implement!)
+
+// Transform applies the transformers of c in sequence.
+func (c *chain) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+        // Set up src and dst in the chain.
+        srcL := &c.link[0]
+        dstL := &c.link[len(c.link)-1]
+        srcL.b, srcL.p, srcL.n = src, 0, len(src)
+        dstL.b, dstL.n = dst, 0
+        var lastFull, needProgress bool // for detecting progress
+
+        // i is the index of the next Transformer to apply, for i in [low, high].
+        // low is the lowest index for which c.link[low] may still produce bytes.
+        // high is the highest index for which c.link[high] has a Transformer.
+        // The error returned by Transform determines whether to increase or
+        // decrease i. We try to completely fill a buffer before converting it.
+        for low, i, high := c.errStart, c.errStart, len(c.link)-2; low <= i && i <= high; {
+                in, out := &c.link[i], &c.link[i+1]
+                nDst, nSrc, err0 := in.t.Transform(out.dst(), in.src(), atEOF && low == i)
+                out.n += nDst
+                in.p += nSrc
+                if i > 0 && in.p == in.n {
+                        in.p, in.n = 0, 0
+                }
+                needProgress, lastFull = lastFull, false
+                switch err0 {
+                case ErrShortDst:
+                        // Process the destination buffer next. Return if we are already
+                        // at the high index.
+                        if i == high {
+                                return dstL.n, srcL.p, ErrShortDst
+                        }
+                        if out.n != 0 {
+                                i++
+                                // If the Transformer at the next index is not able to process any
+                                // source bytes there is nothing that can be done to make progress
+                                // and the bytes will remain unprocessed. lastFull is used to
+                                // detect this and break out of the loop with a fatal error.
+                                lastFull = true
+                                continue
+                        }
+                        // The destination buffer was too small, but is completely empty.
+                        // Return a fatal error as this transformation can never complete.
+                        c.fatalError(i, errShortInternal)
+                case ErrShortSrc:
+                        if i == 0 {
+                                // Save ErrShortSrc in err. All other errors take precedence.
+                                err = ErrShortSrc
+                                break
+                        }
+                        // Source bytes were depleted before filling up the destination buffer.
+                        // Verify we made some progress, move the remaining bytes to the errStart
+                        // and try to get more source bytes.
+                        if needProgress && nSrc == 0 || in.n-in.p == len(in.b) {
+                                // There were not enough source bytes to proceed while the source
+                                // buffer cannot hold any more bytes. Return a fatal error as this
+                                // transformation can never complete.
+                                c.fatalError(i, errShortInternal)
+                                break
+                        }
+                        // in.b is an internal buffer and we can make progress.
+                        in.p, in.n = 0, copy(in.b, in.src())
+                        fallthrough
+                case nil:
+                        // if i == low, we have depleted the bytes at index i or any lower levels.
+                        // In that case we increase low and i. In all other cases we decrease i to
+                        // fetch more bytes before proceeding to the next index.
+                        if i > low {
+                                i--
+                                continue
+                        }
+                default:
+                        c.fatalError(i, err0)
+                }
+                // Exhausted level low or fatal error: increase low and continue
+                // to process the bytes accepted so far.
+                i++
+                low = i
+        }
+
+        // If c.errStart > 0, this means we found a fatal error.  We will clear
+        // all upstream buffers. At this point, no more progress can be made
+        // downstream, as Transform would have bailed while handling ErrShortDst.
+        if c.errStart > 0 {
+                for i := 1; i < c.errStart; i++ {
+                        c.link[i].p, c.link[i].n = 0, 0
+                }
+                err, c.errStart, c.err = c.err, 0, nil
+        }
+        return dstL.n, srcL.p, err
+}
+
+// Deprecated: Use runes.Remove instead.
+func RemoveFunc(f func(r rune) bool) Transformer {
+        return removeF(f)
+}
+
+type removeF func(r rune) bool
+
+func (removeF) Reset() {}
+
+// Transform implements the Transformer interface.
+func (t removeF) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+        for r, sz := rune(0), 0; len(src) > 0; src = src[sz:] {
+
+                if r = rune(src[0]); r < utf8.RuneSelf {
+                        sz = 1
+                } else {
+                        r, sz = utf8.DecodeRune(src)
+
+                        if sz == 1 {
+                                // Invalid rune.
+                                if !atEOF && !utf8.FullRune(src) {
+                                        err = ErrShortSrc
+                                        break
+                                }
+                                // We replace illegal bytes with RuneError. Not doing so might
+                                // otherwise turn a sequence of invalid UTF-8 into valid UTF-8.
+                                // The resulting byte sequence may subsequently contain runes
+                                // for which t(r) is true that were passed unnoticed.
+                                if !t(r) {
+                                        if nDst+3 > len(dst) {
+                                                err = ErrShortDst
+                                                break
+                                        }
+                                        nDst += copy(dst[nDst:], "\uFFFD")
+                                }
+                                nSrc++
+                                continue
+                        }
+                }
+
+                if !t(r) {
+                        if nDst+sz > len(dst) {
+                                err = ErrShortDst
+                                break
+                        }
+                        nDst += copy(dst[nDst:], src[:sz])
+                }
+                nSrc += sz
+        }
+        return
+}
+
+// grow returns a new []byte that is longer than b, and copies the first n bytes
+// of b to the start of the new slice.
+func grow(b []byte, n int) []byte {
+        m := len(b)
+        if m <= 32 {
+                m = 64
+        } else if m <= 256 {
+                m *= 2
+        } else {
+                m += m >> 1
+        }
+        buf := make([]byte, m)
+        copy(buf, b[:n])
+        return buf
+}
+
+const initialBufSize = 128
+
+// String returns a string with the result of converting s[:n] using t, where
+// n <= len(s). If err == nil, n will be len(s). It calls Reset on t.
+func String(t Transformer, s string) (result string, n int, err error) {
+        t.Reset()
+        if s == "" {
+                // Fast path for the common case for empty input. Results in about a
+                // 86% reduction of running time for BenchmarkStringLowerEmpty.
+                if _, _, err := t.Transform(nil, nil, true); err == nil {
+                        return "", 0, nil
+                }
+        }
+
+        // Allocate only once. Note that both dst and src escape when passed to
+        // Transform.
+        buf := [2 * initialBufSize]byte{}
+        dst := buf[:initialBufSize:initialBufSize]
+        src := buf[initialBufSize : 2*initialBufSize]
+
+        // The input string s is transformed in multiple chunks (starting with a
+        // chunk size of initialBufSize). nDst and nSrc are per-chunk (or
+        // per-Transform-call) indexes, pDst and pSrc are overall indexes.
+        nDst, nSrc := 0, 0
+        pDst, pSrc := 0, 0
+
+        // pPrefix is the length of a common prefix: the first pPrefix bytes of the
+        // result will equal the first pPrefix bytes of s. It is not guaranteed to
+        // be the largest such value, but if pPrefix, len(result) and len(s) are
+        // all equal after the final transform (i.e. calling Transform with atEOF
+        // being true returned nil error) then we don't need to allocate a new
+        // result string.
+        pPrefix := 0
+        for {
+                // Invariant: pDst == pPrefix && pSrc == pPrefix.
+
+                n := copy(src, s[pSrc:])
+                nDst, nSrc, err = t.Transform(dst, src[:n], pSrc+n == len(s))
+                pDst += nDst
+                pSrc += nSrc
+
+                // TODO:  let transformers implement an optional Spanner interface, akin
+                // to norm's QuickSpan. This would even allow us to avoid any allocation.
+                if !bytes.Equal(dst[:nDst], src[:nSrc]) {
+                        break
+                }
+                pPrefix = pSrc
+                if err == ErrShortDst {
+                        // A buffer can only be short if a transformer modifies its input.
+                        break
+                } else if err == ErrShortSrc {
+                        if nSrc == 0 {
+                                // No progress was made.
+                                break
+                        }
+                        // Equal so far and !atEOF, so continue checking.
+                } else if err != nil || pPrefix == len(s) {
+                        return string(s[:pPrefix]), pPrefix, err
+                }
+        }
+        // Post-condition: pDst == pPrefix + nDst && pSrc == pPrefix + nSrc.
+
+        // We have transformed the first pSrc bytes of the input s to become pDst
+        // transformed bytes. Those transformed bytes are discontiguous: the first
+        // pPrefix of them equal s[:pPrefix] and the last nDst of them equal
+        // dst[:nDst]. We copy them around, into a new dst buffer if necessary, so
+        // that they become one contiguous slice: dst[:pDst].
+        if pPrefix != 0 {
+                newDst := dst
+                if pDst > len(newDst) {
+                        newDst = make([]byte, len(s)+nDst-nSrc)
+                }
+                copy(newDst[pPrefix:pDst], dst[:nDst])
+                copy(newDst[:pPrefix], s[:pPrefix])
+                dst = newDst
+        }
+
+        // Prevent duplicate Transform calls with atEOF being true at the end of
+        // the input. Also return if we have an unrecoverable error.
+        if (err == nil && pSrc == len(s)) ||
+                (err != nil && err != ErrShortDst && err != ErrShortSrc) {
+                return string(dst[:pDst]), pSrc, err
+        }
+
+        // Transform the remaining input, growing dst and src buffers as necessary.
+        for {
+                n := copy(src, s[pSrc:])
+                atEOF := pSrc+n == len(s)
+                nDst, nSrc, err := t.Transform(dst[pDst:], src[:n], atEOF)
+                pDst += nDst
+                pSrc += nSrc
+
+                // If we got ErrShortDst or ErrShortSrc, do not grow as long as we can
+                // make progress. This may avoid excessive allocations.
+                if err == ErrShortDst {
+                        if nDst == 0 {
+                                dst = grow(dst, pDst)
+                        }
+                } else if err == ErrShortSrc {
+                        if atEOF {
+                                return string(dst[:pDst]), pSrc, err
+                        }
+                        if nSrc == 0 {
+                                src = grow(src, 0)
+                        }
+                } else if err != nil || pSrc == len(s) {
+                        return string(dst[:pDst]), pSrc, err
+                }
+        }
+}
+
+// Bytes returns a new byte slice with the result of converting b[:n] using t,
+// where n <= len(b). If err == nil, n will be len(b). It calls Reset on t.
+func Bytes(t Transformer, b []byte) (result []byte, n int, err error) {
+        return doAppend(t, 0, make([]byte, len(b)), b)
+}
+
+// Append appends the result of converting src[:n] using t to dst, where
+// n <= len(src), If err == nil, n will be len(src). It calls Reset on t.
+func Append(t Transformer, dst, src []byte) (result []byte, n int, err error) {
+        if len(dst) == cap(dst) {
+                n := len(src) + len(dst) // It is okay for this to be 0.
+                b := make([]byte, n)
+                dst = b[:copy(b, dst)]
+        }
+        return doAppend(t, len(dst), dst[:cap(dst)], src)
+}
+
+func doAppend(t Transformer, pDst int, dst, src []byte) (result []byte, n int, err error) {
+        t.Reset()
+        pSrc := 0
+        for {
+                nDst, nSrc, err := t.Transform(dst[pDst:], src[pSrc:], true)
+                pDst += nDst
+                pSrc += nSrc
+                if err != ErrShortDst {
+                        return dst[:pDst], pSrc, err
+                }
+
+                // Grow the destination buffer, but do not grow as long as we can make
+                // progress. This may avoid excessive allocations.
+                if nDst == 0 {
+                        dst = grow(dst, pDst)
+                }
+        }
+}