obtained gcc-4.6.4.tar.bz2 from upstream website;upstream

verified gcc-4.6.4.tar.bz2.sig;
imported gcc-4.6.4 source tree from verified upstream tarball.

downloading a git-generated archive based on the 'upstream' tag
should provide you with a source tree that is binary identical
to the one extracted from the above tarball.

if you have obtained the source via the command 'git clone',
however, do note that line-endings of files in your working
directory might differ from line-endings of the respective
files in the upstream repository.

4 files changed, 806 insertions, 0 deletions

diff --git a/libgo/go/compress/gzip/gunzip.go b/libgo/go/compress/gzip/gunzip.go
new file mode 100644
index 000000000..3c0b3c5e5
--- /dev/null
+++ b/libgo/go/compress/gzip/gunzip.go
@@ -0,0 +1,230 @@
+// Copyright 2009 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.
+
+// The gzip package implements reading and writing of
+// gzip format compressed files, as specified in RFC 1952.
+package gzip
+
+import (
+	"bufio"
+	"compress/flate"
+	"hash"
+	"hash/crc32"
+	"io"
+	"os"
+)
+
+// BUG(nigeltao): Comments and Names don't properly map UTF-8 character codes outside of
+// the 0x00-0x7f range to ISO 8859-1 (Latin-1).
+
+const (
+	gzipID1     = 0x1f
+	gzipID2     = 0x8b
+	gzipDeflate = 8
+	flagText    = 1 << 0
+	flagHdrCrc  = 1 << 1
+	flagExtra   = 1 << 2
+	flagName    = 1 << 3
+	flagComment = 1 << 4
+)
+
+func makeReader(r io.Reader) flate.Reader {
+	if rr, ok := r.(flate.Reader); ok {
+		return rr
+	}
+	return bufio.NewReader(r)
+}
+
+var HeaderError os.Error = os.ErrorString("invalid gzip header")
+var ChecksumError os.Error = os.ErrorString("gzip checksum error")
+
+// The gzip file stores a header giving metadata about the compressed file.
+// That header is exposed as the fields of the Compressor and Decompressor structs.
+type Header struct {
+	Comment string // comment
+	Extra   []byte // "extra data"
+	Mtime   uint32 // modification time (seconds since January 1, 1970)
+	Name    string // file name
+	OS      byte   // operating system type
+}
+
+// An Decompressor is an io.Reader that can be read to retrieve
+// uncompressed data from a gzip-format compressed file.
+//
+// In general, a gzip file can be a concatenation of gzip files,
+// each with its own header.  Reads from the Decompressor
+// return the concatenation of the uncompressed data of each.
+// Only the first header is recorded in the Decompressor fields.
+//
+// Gzip files store a length and checksum of the uncompressed data.
+// The Decompressor will return a ChecksumError when Read
+// reaches the end of the uncompressed data if it does not
+// have the expected length or checksum.  Clients should treat data
+// returned by Read as tentative until they receive the successful
+// (zero length, nil error) Read marking the end of the data.
+type Decompressor struct {
+	Header
+	r            flate.Reader
+	decompressor io.ReadCloser
+	digest       hash.Hash32
+	size         uint32
+	flg          byte
+	buf          [512]byte
+	err          os.Error
+}
+
+// NewReader creates a new Decompressor reading the given reader.
+// The implementation buffers input and may read more data than necessary from r.
+// It is the caller's responsibility to call Close on the Decompressor when done.
+func NewReader(r io.Reader) (*Decompressor, os.Error) {
+	z := new(Decompressor)
+	z.r = makeReader(r)
+	z.digest = crc32.NewIEEE()
+	if err := z.readHeader(true); err != nil {
+		z.err = err
+		return nil, err
+	}
+	return z, nil
+}
+
+// GZIP (RFC 1952) is little-endian, unlike ZLIB (RFC 1950).
+func get4(p []byte) uint32 {
+	return uint32(p[0]) | uint32(p[1])<<8 | uint32(p[2])<<16 | uint32(p[3])<<24
+}
+
+func (z *Decompressor) readString() (string, os.Error) {
+	var err os.Error
+	for i := 0; ; i++ {
+		if i >= len(z.buf) {
+			return "", HeaderError
+		}
+		z.buf[i], err = z.r.ReadByte()
+		if err != nil {
+			return "", err
+		}
+		if z.buf[i] == 0 {
+			// GZIP (RFC 1952) specifies that strings are NUL-terminated ISO 8859-1 (Latin-1).
+			// TODO(nigeltao): Convert from ISO 8859-1 (Latin-1) to UTF-8.
+			return string(z.buf[0:i]), nil
+		}
+	}
+	panic("not reached")
+}
+
+func (z *Decompressor) read2() (uint32, os.Error) {
+	_, err := io.ReadFull(z.r, z.buf[0:2])
+	if err != nil {
+		return 0, err
+	}
+	return uint32(z.buf[0]) | uint32(z.buf[1])<<8, nil
+}
+
+func (z *Decompressor) readHeader(save bool) os.Error {
+	_, err := io.ReadFull(z.r, z.buf[0:10])
+	if err != nil {
+		return err
+	}
+	if z.buf[0] != gzipID1 || z.buf[1] != gzipID2 || z.buf[2] != gzipDeflate {
+		return HeaderError
+	}
+	z.flg = z.buf[3]
+	if save {
+		z.Mtime = get4(z.buf[4:8])
+		// z.buf[8] is xfl, ignored
+		z.OS = z.buf[9]
+	}
+	z.digest.Reset()
+	z.digest.Write(z.buf[0:10])
+
+	if z.flg&flagExtra != 0 {
+		n, err := z.read2()
+		if err != nil {
+			return err
+		}
+		data := make([]byte, n)
+		if _, err = io.ReadFull(z.r, data); err != nil {
+			return err
+		}
+		if save {
+			z.Extra = data
+		}
+	}
+
+	var s string
+	if z.flg&flagName != 0 {
+		if s, err = z.readString(); err != nil {
+			return err
+		}
+		if save {
+			z.Name = s
+		}
+	}
+
+	if z.flg&flagComment != 0 {
+		if s, err = z.readString(); err != nil {
+			return err
+		}
+		if save {
+			z.Comment = s
+		}
+	}
+
+	if z.flg&flagHdrCrc != 0 {
+		n, err := z.read2()
+		if err != nil {
+			return err
+		}
+		sum := z.digest.Sum32() & 0xFFFF
+		if n != sum {
+			return HeaderError
+		}
+	}
+
+	z.digest.Reset()
+	z.decompressor = flate.NewReader(z.r)
+	return nil
+}
+
+func (z *Decompressor) Read(p []byte) (n int, err os.Error) {
+	if z.err != nil {
+		return 0, z.err
+	}
+	if len(p) == 0 {
+		return 0, nil
+	}
+
+	n, err = z.decompressor.Read(p)
+	z.digest.Write(p[0:n])
+	z.size += uint32(n)
+	if n != 0 || err != os.EOF {
+		z.err = err
+		return
+	}
+
+	// Finished file; check checksum + size.
+	if _, err := io.ReadFull(z.r, z.buf[0:8]); err != nil {
+		z.err = err
+		return 0, err
+	}
+	crc32, isize := get4(z.buf[0:4]), get4(z.buf[4:8])
+	sum := z.digest.Sum32()
+	if sum != crc32 || isize != z.size {
+		z.err = ChecksumError
+		return 0, z.err
+	}
+
+	// File is ok; is there another?
+	if err = z.readHeader(false); err != nil {
+		z.err = err
+		return
+	}
+
+	// Yes.  Reset and read from it.
+	z.digest.Reset()
+	z.size = 0
+	return z.Read(p)
+}
+
+// Calling Close does not close the wrapped io.Reader originally passed to NewReader.
+func (z *Decompressor) Close() os.Error { return z.decompressor.Close() }
diff --git a/libgo/go/compress/gzip/gunzip_test.go b/libgo/go/compress/gzip/gunzip_test.go
new file mode 100644
index 000000000..1c08c7374
--- /dev/null
+++ b/libgo/go/compress/gzip/gunzip_test.go
@@ -0,0 +1,305 @@
+// Copyright 2009 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 gzip
+
+import (
+	"bytes"
+	"io"
+	"os"
+	"testing"
+)
+
+type gunzipTest struct {
+	name string
+	desc string
+	raw  string
+	gzip []byte
+	err  os.Error
+}
+
+var gunzipTests = []gunzipTest{
+	{ // has 1 empty fixed-huffman block
+		"empty.txt",
+		"empty.txt",
+		"",
+		[]byte{
+			0x1f, 0x8b, 0x08, 0x08, 0xf7, 0x5e, 0x14, 0x4a,
+			0x00, 0x03, 0x65, 0x6d, 0x70, 0x74, 0x79, 0x2e,
+			0x74, 0x78, 0x74, 0x00, 0x03, 0x00, 0x00, 0x00,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		},
+		nil,
+	},
+	{ // has 1 non-empty fixed huffman block
+		"hello.txt",
+		"hello.txt",
+		"hello world\n",
+		[]byte{
+			0x1f, 0x8b, 0x08, 0x08, 0xc8, 0x58, 0x13, 0x4a,
+			0x00, 0x03, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x2e,
+			0x74, 0x78, 0x74, 0x00, 0xcb, 0x48, 0xcd, 0xc9,
+			0xc9, 0x57, 0x28, 0xcf, 0x2f, 0xca, 0x49, 0xe1,
+			0x02, 0x00, 0x2d, 0x3b, 0x08, 0xaf, 0x0c, 0x00,
+			0x00, 0x00,
+		},
+		nil,
+	},
+	{ // concatenation
+		"hello.txt",
+		"hello.txt x2",
+		"hello world\n" +
+			"hello world\n",
+		[]byte{
+			0x1f, 0x8b, 0x08, 0x08, 0xc8, 0x58, 0x13, 0x4a,
+			0x00, 0x03, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x2e,
+			0x74, 0x78, 0x74, 0x00, 0xcb, 0x48, 0xcd, 0xc9,
+			0xc9, 0x57, 0x28, 0xcf, 0x2f, 0xca, 0x49, 0xe1,
+			0x02, 0x00, 0x2d, 0x3b, 0x08, 0xaf, 0x0c, 0x00,
+			0x00, 0x00,
+			0x1f, 0x8b, 0x08, 0x08, 0xc8, 0x58, 0x13, 0x4a,
+			0x00, 0x03, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x2e,
+			0x74, 0x78, 0x74, 0x00, 0xcb, 0x48, 0xcd, 0xc9,
+			0xc9, 0x57, 0x28, 0xcf, 0x2f, 0xca, 0x49, 0xe1,
+			0x02, 0x00, 0x2d, 0x3b, 0x08, 0xaf, 0x0c, 0x00,
+			0x00, 0x00,
+		},
+		nil,
+	},
+	{ // has a fixed huffman block with some length-distance pairs
+		"shesells.txt",
+		"shesells.txt",
+		"she sells seashells by the seashore\n",
+		[]byte{
+			0x1f, 0x8b, 0x08, 0x08, 0x72, 0x66, 0x8b, 0x4a,
+			0x00, 0x03, 0x73, 0x68, 0x65, 0x73, 0x65, 0x6c,
+			0x6c, 0x73, 0x2e, 0x74, 0x78, 0x74, 0x00, 0x2b,
+			0xce, 0x48, 0x55, 0x28, 0x4e, 0xcd, 0xc9, 0x29,
+			0x06, 0x92, 0x89, 0xc5, 0x19, 0x60, 0x56, 0x52,
+			0xa5, 0x42, 0x09, 0x58, 0x18, 0x28, 0x90, 0x5f,
+			0x94, 0xca, 0x05, 0x00, 0x76, 0xb0, 0x3b, 0xeb,
+			0x24, 0x00, 0x00, 0x00,
+		},
+		nil,
+	},
+	{ // has dynamic huffman blocks
+		"gettysburg",
+		"gettysburg",
+		"  Four score and seven years ago our fathers brought forth on\n" +
+			"this continent, a new nation, conceived in Liberty, and dedicated\n" +
+			"to the proposition that all men are created equal.\n" +
+			"  Now we are engaged in a great Civil War, testing whether that\n" +
+			"nation, or any nation so conceived and so dedicated, can long\n" +
+			"endure.\n" +
+			"  We are met on a great battle-field of that war.\n" +
+			"  We have come to dedicate a portion of that field, as a final\n" +
+			"resting place for those who here gave their lives that that\n" +
+			"nation might live.  It is altogether fitting and proper that\n" +
+			"we should do this.\n" +
+			"  But, in a larger sense, we can not dedicate — we can not\n" +
+			"consecrate — we can not hallow — this ground.\n" +
+			"  The brave men, living and dead, who struggled here, have\n" +
+			"consecrated it, far above our poor power to add or detract.\n" +
+			"The world will little note, nor long remember what we say here,\n" +
+			"but it can never forget what they did here.\n" +
+			"  It is for us the living, rather, to be dedicated here to the\n" +
+			"unfinished work which they who fought here have thus far so\n" +
+			"nobly advanced.  It is rather for us to be here dedicated to\n" +
+			"the great task remaining before us — that from these honored\n" +
+			"dead we take increased devotion to that cause for which they\n" +
+			"gave the last full measure of devotion —\n" +
+			"  that we here highly resolve that these dead shall not have\n" +
+			"died in vain — that this nation, under God, shall have a new\n" +
+			"birth of freedom — and that government of the people, by the\n" +
+			"people, for the people, shall not perish from this earth.\n" +
+			"\n" +
+			"Abraham Lincoln, November 19, 1863, Gettysburg, Pennsylvania\n",
+		[]byte{
+			0x1f, 0x8b, 0x08, 0x08, 0xd1, 0x12, 0x2b, 0x4a,
+			0x00, 0x03, 0x67, 0x65, 0x74, 0x74, 0x79, 0x73,
+			0x62, 0x75, 0x72, 0x67, 0x00, 0x65, 0x54, 0xcd,
+			0x6e, 0xd4, 0x30, 0x10, 0xbe, 0xfb, 0x29, 0xe6,
+			0x01, 0x42, 0xa5, 0x0a, 0x09, 0xc1, 0x11, 0x90,
+			0x40, 0x48, 0xa8, 0xe2, 0x80, 0xd4, 0xf3, 0x24,
+			0x9e, 0x24, 0x56, 0xbd, 0x9e, 0xc5, 0x76, 0x76,
+			0x95, 0x1b, 0x0f, 0xc1, 0x13, 0xf2, 0x24, 0x7c,
+			0x63, 0x77, 0x9b, 0x4a, 0x5c, 0xaa, 0x6e, 0x6c,
+			0xcf, 0x7c, 0x7f, 0x33, 0x44, 0x5f, 0x74, 0xcb,
+			0x54, 0x26, 0xcd, 0x42, 0x9c, 0x3c, 0x15, 0xb9,
+			0x48, 0xa2, 0x5d, 0x38, 0x17, 0xe2, 0x45, 0xc9,
+			0x4e, 0x67, 0xae, 0xab, 0xe0, 0xf7, 0x98, 0x75,
+			0x5b, 0xd6, 0x4a, 0xb3, 0xe6, 0xba, 0x92, 0x26,
+			0x57, 0xd7, 0x50, 0x68, 0xd2, 0x54, 0x43, 0x92,
+			0x54, 0x07, 0x62, 0x4a, 0x72, 0xa5, 0xc4, 0x35,
+			0x68, 0x1a, 0xec, 0x60, 0x92, 0x70, 0x11, 0x4f,
+			0x21, 0xd1, 0xf7, 0x30, 0x4a, 0xae, 0xfb, 0xd0,
+			0x9a, 0x78, 0xf1, 0x61, 0xe2, 0x2a, 0xde, 0x55,
+			0x25, 0xd4, 0xa6, 0x73, 0xd6, 0xb3, 0x96, 0x60,
+			0xef, 0xf0, 0x9b, 0x2b, 0x71, 0x8c, 0x74, 0x02,
+			0x10, 0x06, 0xac, 0x29, 0x8b, 0xdd, 0x25, 0xf9,
+			0xb5, 0x71, 0xbc, 0x73, 0x44, 0x0f, 0x7a, 0xa5,
+			0xab, 0xb4, 0x33, 0x49, 0x0b, 0x2f, 0xbd, 0x03,
+			0xd3, 0x62, 0x17, 0xe9, 0x73, 0xb8, 0x84, 0x48,
+			0x8f, 0x9c, 0x07, 0xaa, 0x52, 0x00, 0x6d, 0xa1,
+			0xeb, 0x2a, 0xc6, 0xa0, 0x95, 0x76, 0x37, 0x78,
+			0x9a, 0x81, 0x65, 0x7f, 0x46, 0x4b, 0x45, 0x5f,
+			0xe1, 0x6d, 0x42, 0xe8, 0x01, 0x13, 0x5c, 0x38,
+			0x51, 0xd4, 0xb4, 0x38, 0x49, 0x7e, 0xcb, 0x62,
+			0x28, 0x1e, 0x3b, 0x82, 0x93, 0x54, 0x48, 0xf1,
+			0xd2, 0x7d, 0xe4, 0x5a, 0xa3, 0xbc, 0x99, 0x83,
+			0x44, 0x4f, 0x3a, 0x77, 0x36, 0x57, 0xce, 0xcf,
+			0x2f, 0x56, 0xbe, 0x80, 0x90, 0x9e, 0x84, 0xea,
+			0x51, 0x1f, 0x8f, 0xcf, 0x90, 0xd4, 0x60, 0xdc,
+			0x5e, 0xb4, 0xf7, 0x10, 0x0b, 0x26, 0xe0, 0xff,
+			0xc4, 0xd1, 0xe5, 0x67, 0x2e, 0xe7, 0xc8, 0x93,
+			0x98, 0x05, 0xb8, 0xa8, 0x45, 0xc0, 0x4d, 0x09,
+			0xdc, 0x84, 0x16, 0x2b, 0x0d, 0x9a, 0x21, 0x53,
+			0x04, 0x8b, 0xd2, 0x0b, 0xbd, 0xa2, 0x4c, 0xa7,
+			0x60, 0xee, 0xd9, 0xe1, 0x1d, 0xd1, 0xb7, 0x4a,
+			0x30, 0x8f, 0x63, 0xd5, 0xa5, 0x8b, 0x33, 0x87,
+			0xda, 0x1a, 0x18, 0x79, 0xf3, 0xe3, 0xa6, 0x17,
+			0x94, 0x2e, 0xab, 0x6e, 0xa0, 0xe3, 0xcd, 0xac,
+			0x50, 0x8c, 0xca, 0xa7, 0x0d, 0x76, 0x37, 0xd1,
+			0x23, 0xe7, 0x05, 0x57, 0x8b, 0xa4, 0x22, 0x83,
+			0xd9, 0x62, 0x52, 0x25, 0xad, 0x07, 0xbb, 0xbf,
+			0xbf, 0xff, 0xbc, 0xfa, 0xee, 0x20, 0x73, 0x91,
+			0x29, 0xff, 0x7f, 0x02, 0x71, 0x62, 0x84, 0xb5,
+			0xf6, 0xb5, 0x25, 0x6b, 0x41, 0xde, 0x92, 0xb7,
+			0x76, 0x3f, 0x91, 0x91, 0x31, 0x1b, 0x41, 0x84,
+			0x62, 0x30, 0x0a, 0x37, 0xa4, 0x5e, 0x18, 0x3a,
+			0x99, 0x08, 0xa5, 0xe6, 0x6d, 0x59, 0x22, 0xec,
+			0x33, 0x39, 0x86, 0x26, 0xf5, 0xab, 0x66, 0xc8,
+			0x08, 0x20, 0xcf, 0x0c, 0xd7, 0x47, 0x45, 0x21,
+			0x0b, 0xf6, 0x59, 0xd5, 0xfe, 0x5c, 0x8d, 0xaa,
+			0x12, 0x7b, 0x6f, 0xa1, 0xf0, 0x52, 0x33, 0x4f,
+			0xf5, 0xce, 0x59, 0xd3, 0xab, 0x66, 0x10, 0xbf,
+			0x06, 0xc4, 0x31, 0x06, 0x73, 0xd6, 0x80, 0xa2,
+			0x78, 0xc2, 0x45, 0xcb, 0x03, 0x65, 0x39, 0xc9,
+			0x09, 0xd1, 0x06, 0x04, 0x33, 0x1a, 0x5a, 0xf1,
+			0xde, 0x01, 0xb8, 0x71, 0x83, 0xc4, 0xb5, 0xb3,
+			0xc3, 0x54, 0x65, 0x33, 0x0d, 0x5a, 0xf7, 0x9b,
+			0x90, 0x7c, 0x27, 0x1f, 0x3a, 0x58, 0xa3, 0xd8,
+			0xfd, 0x30, 0x5f, 0xb7, 0xd2, 0x66, 0xa2, 0x93,
+			0x1c, 0x28, 0xb7, 0xe9, 0x1b, 0x0c, 0xe1, 0x28,
+			0x47, 0x26, 0xbb, 0xe9, 0x7d, 0x7e, 0xdc, 0x96,
+			0x10, 0x92, 0x50, 0x56, 0x7c, 0x06, 0xe2, 0x27,
+			0xb4, 0x08, 0xd3, 0xda, 0x7b, 0x98, 0x34, 0x73,
+			0x9f, 0xdb, 0xf6, 0x62, 0xed, 0x31, 0x41, 0x13,
+			0xd3, 0xa2, 0xa8, 0x4b, 0x3a, 0xc6, 0x1d, 0xe4,
+			0x2f, 0x8c, 0xf8, 0xfb, 0x97, 0x64, 0xf4, 0xb6,
+			0x2f, 0x80, 0x5a, 0xf3, 0x56, 0xe0, 0x40, 0x50,
+			0xd5, 0x19, 0xd0, 0x1e, 0xfc, 0xca, 0xe5, 0xc9,
+			0xd4, 0x60, 0x00, 0x81, 0x2e, 0xa3, 0xcc, 0xb6,
+			0x52, 0xf0, 0xb4, 0xdb, 0x69, 0x99, 0xce, 0x7a,
+			0x32, 0x4c, 0x08, 0xed, 0xaa, 0x10, 0x10, 0xe3,
+			0x6f, 0xee, 0x99, 0x68, 0x95, 0x9f, 0x04, 0x71,
+			0xb2, 0x49, 0x2f, 0x62, 0xa6, 0x5e, 0xb4, 0xef,
+			0x02, 0xed, 0x4f, 0x27, 0xde, 0x4a, 0x0f, 0xfd,
+			0xc1, 0xcc, 0xdd, 0x02, 0x8f, 0x08, 0x16, 0x54,
+			0xdf, 0xda, 0xca, 0xe0, 0x82, 0xf1, 0xb4, 0x31,
+			0x7a, 0xa9, 0x81, 0xfe, 0x90, 0xb7, 0x3e, 0xdb,
+			0xd3, 0x35, 0xc0, 0x20, 0x80, 0x33, 0x46, 0x4a,
+			0x63, 0xab, 0xd1, 0x0d, 0x29, 0xd2, 0xe2, 0x84,
+			0xb8, 0xdb, 0xfa, 0xe9, 0x89, 0x44, 0x86, 0x7c,
+			0xe8, 0x0b, 0xe6, 0x02, 0x6a, 0x07, 0x9b, 0x96,
+			0xd0, 0xdb, 0x2e, 0x41, 0x4c, 0xa1, 0xd5, 0x57,
+			0x45, 0x14, 0xfb, 0xe3, 0xa6, 0x72, 0x5b, 0x87,
+			0x6e, 0x0c, 0x6d, 0x5b, 0xce, 0xe0, 0x2f, 0xe2,
+			0x21, 0x81, 0x95, 0xb0, 0xe8, 0xb6, 0x32, 0x0b,
+			0xb2, 0x98, 0x13, 0x52, 0x5d, 0xfb, 0xec, 0x63,
+			0x17, 0x8a, 0x9e, 0x23, 0x22, 0x36, 0xee, 0xcd,
+			0xda, 0xdb, 0xcf, 0x3e, 0xf1, 0xc7, 0xf1, 0x01,
+			0x12, 0x93, 0x0a, 0xeb, 0x6f, 0xf2, 0x02, 0x15,
+			0x96, 0x77, 0x5d, 0xef, 0x9c, 0xfb, 0x88, 0x91,
+			0x59, 0xf9, 0x84, 0xdd, 0x9b, 0x26, 0x8d, 0x80,
+			0xf9, 0x80, 0x66, 0x2d, 0xac, 0xf7, 0x1f, 0x06,
+			0xba, 0x7f, 0xff, 0xee, 0xed, 0x40, 0x5f, 0xa5,
+			0xd6, 0xbd, 0x8c, 0x5b, 0x46, 0xd2, 0x7e, 0x48,
+			0x4a, 0x65, 0x8f, 0x08, 0x42, 0x60, 0xf7, 0x0f,
+			0xb9, 0x16, 0x0b, 0x0c, 0x1a, 0x06, 0x00, 0x00,
+		},
+		nil,
+	},
+	{ // has 1 non-empty fixed huffman block then garbage
+		"hello.txt",
+		"hello.txt + garbage",
+		"hello world\n",
+		[]byte{
+			0x1f, 0x8b, 0x08, 0x08, 0xc8, 0x58, 0x13, 0x4a,
+			0x00, 0x03, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x2e,
+			0x74, 0x78, 0x74, 0x00, 0xcb, 0x48, 0xcd, 0xc9,
+			0xc9, 0x57, 0x28, 0xcf, 0x2f, 0xca, 0x49, 0xe1,
+			0x02, 0x00, 0x2d, 0x3b, 0x08, 0xaf, 0x0c, 0x00,
+			0x00, 0x00, 'g', 'a', 'r', 'b', 'a', 'g', 'e', '!', '!', '!',
+		},
+		HeaderError,
+	},
+	{ // has 1 non-empty fixed huffman block not enough header
+		"hello.txt",
+		"hello.txt + garbage",
+		"hello world\n",
+		[]byte{
+			0x1f, 0x8b, 0x08, 0x08, 0xc8, 0x58, 0x13, 0x4a,
+			0x00, 0x03, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x2e,
+			0x74, 0x78, 0x74, 0x00, 0xcb, 0x48, 0xcd, 0xc9,
+			0xc9, 0x57, 0x28, 0xcf, 0x2f, 0xca, 0x49, 0xe1,
+			0x02, 0x00, 0x2d, 0x3b, 0x08, 0xaf, 0x0c, 0x00,
+			0x00, 0x00, gzipID1,
+		},
+		io.ErrUnexpectedEOF,
+	},
+	{ // has 1 non-empty fixed huffman block but corrupt checksum
+		"hello.txt",
+		"hello.txt + corrupt checksum",
+		"hello world\n",
+		[]byte{
+			0x1f, 0x8b, 0x08, 0x08, 0xc8, 0x58, 0x13, 0x4a,
+			0x00, 0x03, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x2e,
+			0x74, 0x78, 0x74, 0x00, 0xcb, 0x48, 0xcd, 0xc9,
+			0xc9, 0x57, 0x28, 0xcf, 0x2f, 0xca, 0x49, 0xe1,
+			0x02, 0x00, 0xff, 0xff, 0xff, 0xff, 0x0c, 0x00,
+			0x00, 0x00,
+		},
+		ChecksumError,
+	},
+	{ // has 1 non-empty fixed huffman block but corrupt size
+		"hello.txt",
+		"hello.txt + corrupt size",
+		"hello world\n",
+		[]byte{
+			0x1f, 0x8b, 0x08, 0x08, 0xc8, 0x58, 0x13, 0x4a,
+			0x00, 0x03, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x2e,
+			0x74, 0x78, 0x74, 0x00, 0xcb, 0x48, 0xcd, 0xc9,
+			0xc9, 0x57, 0x28, 0xcf, 0x2f, 0xca, 0x49, 0xe1,
+			0x02, 0x00, 0x2d, 0x3b, 0x08, 0xaf, 0xff, 0x00,
+			0x00, 0x00,
+		},
+		ChecksumError,
+	},
+}
+
+func TestDecompressor(t *testing.T) {
+	b := new(bytes.Buffer)
+	for _, tt := range gunzipTests {
+		in := bytes.NewBuffer(tt.gzip)
+		gzip, err := NewReader(in)
+		if err != nil {
+			t.Errorf("%s: NewReader: %s", tt.name, err)
+			continue
+		}
+		defer gzip.Close()
+		if tt.name != gzip.Name {
+			t.Errorf("%s: got name %s", tt.name, gzip.Name)
+		}
+		b.Reset()
+		n, err := io.Copy(b, gzip)
+		if err != tt.err {
+			t.Errorf("%s: io.Copy: %v want %v", tt.name, err, tt.err)
+		}
+		s := b.String()
+		if s != tt.raw {
+			t.Errorf("%s: got %d-byte %q want %d-byte %q", tt.name, n, s, len(tt.raw), tt.raw)
+		}
+	}
+}
diff --git a/libgo/go/compress/gzip/gzip.go b/libgo/go/compress/gzip/gzip.go
new file mode 100644
index 000000000..8860d10af
--- /dev/null
+++ b/libgo/go/compress/gzip/gzip.go
@@ -0,0 +1,187 @@
+// Copyright 2010 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 gzip
+
+import (
+	"compress/flate"
+	"hash"
+	"hash/crc32"
+	"io"
+	"os"
+)
+
+// These constants are copied from the flate package, so that code that imports
+// "compress/gzip" does not also have to import "compress/flate".
+const (
+	NoCompression      = flate.NoCompression
+	BestSpeed          = flate.BestSpeed
+	BestCompression    = flate.BestCompression
+	DefaultCompression = flate.DefaultCompression
+)
+
+// A Compressor is an io.WriteCloser that satisfies writes by compressing data written
+// to its wrapped io.Writer.
+type Compressor struct {
+	Header
+	w          io.Writer
+	level      int
+	compressor io.WriteCloser
+	digest     hash.Hash32
+	size       uint32
+	closed     bool
+	buf        [10]byte
+	err        os.Error
+}
+
+// NewWriter calls NewWriterLevel with the default compression level.
+func NewWriter(w io.Writer) (*Compressor, os.Error) {
+	return NewWriterLevel(w, DefaultCompression)
+}
+
+// NewWriterLevel creates a new Compressor writing to the given writer.
+// Writes may be buffered and not flushed until Close.
+// Callers that wish to set the fields in Compressor.Header must
+// do so before the first call to Write or Close.
+// It is the caller's responsibility to call Close on the WriteCloser when done.
+// level is the compression level, which can be DefaultCompression, NoCompression,
+// or any integer value between BestSpeed and BestCompression (inclusive).
+func NewWriterLevel(w io.Writer, level int) (*Compressor, os.Error) {
+	z := new(Compressor)
+	z.OS = 255 // unknown
+	z.w = w
+	z.level = level
+	z.digest = crc32.NewIEEE()
+	return z, nil
+}
+
+// GZIP (RFC 1952) is little-endian, unlike ZLIB (RFC 1950).
+func put2(p []byte, v uint16) {
+	p[0] = uint8(v >> 0)
+	p[1] = uint8(v >> 8)
+}
+
+func put4(p []byte, v uint32) {
+	p[0] = uint8(v >> 0)
+	p[1] = uint8(v >> 8)
+	p[2] = uint8(v >> 16)
+	p[3] = uint8(v >> 24)
+}
+
+// writeBytes writes a length-prefixed byte slice to z.w.
+func (z *Compressor) writeBytes(b []byte) os.Error {
+	if len(b) > 0xffff {
+		return os.NewError("gzip.Write: Extra data is too large")
+	}
+	put2(z.buf[0:2], uint16(len(b)))
+	_, err := z.w.Write(z.buf[0:2])
+	if err != nil {
+		return err
+	}
+	_, err = z.w.Write(b)
+	return err
+}
+
+// writeString writes a string (in ISO 8859-1 (Latin-1) format) to z.w.
+func (z *Compressor) writeString(s string) os.Error {
+	// GZIP (RFC 1952) specifies that strings are NUL-terminated ISO 8859-1 (Latin-1).
+	// TODO(nigeltao): Convert from UTF-8 to ISO 8859-1 (Latin-1).
+	for _, v := range s {
+		if v == 0 || v > 0x7f {
+			return os.NewError("gzip.Write: non-ASCII header string")
+		}
+	}
+	_, err := io.WriteString(z.w, s)
+	if err != nil {
+		return err
+	}
+	// GZIP strings are NUL-terminated.
+	z.buf[0] = 0
+	_, err = z.w.Write(z.buf[0:1])
+	return err
+}
+
+func (z *Compressor) Write(p []byte) (int, os.Error) {
+	if z.err != nil {
+		return 0, z.err
+	}
+	var n int
+	// Write the GZIP header lazily.
+	if z.compressor == nil {
+		z.buf[0] = gzipID1
+		z.buf[1] = gzipID2
+		z.buf[2] = gzipDeflate
+		z.buf[3] = 0
+		if z.Extra != nil {
+			z.buf[3] |= 0x04
+		}
+		if z.Name != "" {
+			z.buf[3] |= 0x08
+		}
+		if z.Comment != "" {
+			z.buf[3] |= 0x10
+		}
+		put4(z.buf[4:8], z.Mtime)
+		if z.level == BestCompression {
+			z.buf[8] = 2
+		} else if z.level == BestSpeed {
+			z.buf[8] = 4
+		} else {
+			z.buf[8] = 0
+		}
+		z.buf[9] = z.OS
+		n, z.err = z.w.Write(z.buf[0:10])
+		if z.err != nil {
+			return n, z.err
+		}
+		if z.Extra != nil {
+			z.err = z.writeBytes(z.Extra)
+			if z.err != nil {
+				return n, z.err
+			}
+		}
+		if z.Name != "" {
+			z.err = z.writeString(z.Name)
+			if z.err != nil {
+				return n, z.err
+			}
+		}
+		if z.Comment != "" {
+			z.err = z.writeString(z.Comment)
+			if z.err != nil {
+				return n, z.err
+			}
+		}
+		z.compressor = flate.NewWriter(z.w, z.level)
+	}
+	z.size += uint32(len(p))
+	z.digest.Write(p)
+	n, z.err = z.compressor.Write(p)
+	return n, z.err
+}
+
+// Calling Close does not close the wrapped io.Writer originally passed to NewWriter.
+func (z *Compressor) Close() os.Error {
+	if z.err != nil {
+		return z.err
+	}
+	if z.closed {
+		return nil
+	}
+	z.closed = true
+	if z.compressor == nil {
+		z.Write(nil)
+		if z.err != nil {
+			return z.err
+		}
+	}
+	z.err = z.compressor.Close()
+	if z.err != nil {
+		return z.err
+	}
+	put4(z.buf[0:4], z.digest.Sum32())
+	put4(z.buf[4:8], z.size)
+	_, z.err = z.w.Write(z.buf[0:8])
+	return z.err
+}
diff --git a/libgo/go/compress/gzip/gzip_test.go b/libgo/go/compress/gzip/gzip_test.go
new file mode 100644
index 000000000..23f351405
--- /dev/null
+++ b/libgo/go/compress/gzip/gzip_test.go
@@ -0,0 +1,84 @@
+// Copyright 2010 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 gzip
+
+import (
+	"io"
+	"io/ioutil"
+	"testing"
+)
+
+// pipe creates two ends of a pipe that gzip and gunzip, and runs dfunc at the
+// writer end and ifunc at the reader end.
+func pipe(t *testing.T, dfunc func(*Compressor), cfunc func(*Decompressor)) {
+	piper, pipew := io.Pipe()
+	defer piper.Close()
+	go func() {
+		defer pipew.Close()
+		compressor, err := NewWriter(pipew)
+		if err != nil {
+			t.Fatalf("%v", err)
+		}
+		defer compressor.Close()
+		dfunc(compressor)
+	}()
+	decompressor, err := NewReader(piper)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	defer decompressor.Close()
+	cfunc(decompressor)
+}
+
+// Tests that an empty payload still forms a valid GZIP stream.
+func TestEmpty(t *testing.T) {
+	pipe(t,
+		func(compressor *Compressor) {},
+		func(decompressor *Decompressor) {
+			b, err := ioutil.ReadAll(decompressor)
+			if err != nil {
+				t.Fatalf("%v", err)
+			}
+			if len(b) != 0 {
+				t.Fatalf("did not read an empty slice")
+			}
+		})
+}
+
+// Tests that gzipping and then gunzipping is the identity function.
+func TestWriter(t *testing.T) {
+	pipe(t,
+		func(compressor *Compressor) {
+			compressor.Comment = "comment"
+			compressor.Extra = []byte("extra")
+			compressor.Mtime = 1e8
+			compressor.Name = "name"
+			_, err := compressor.Write([]byte("payload"))
+			if err != nil {
+				t.Fatalf("%v", err)
+			}
+		},
+		func(decompressor *Decompressor) {
+			b, err := ioutil.ReadAll(decompressor)
+			if err != nil {
+				t.Fatalf("%v", err)
+			}
+			if string(b) != "payload" {
+				t.Fatalf("payload is %q, want %q", string(b), "payload")
+			}
+			if decompressor.Comment != "comment" {
+				t.Fatalf("comment is %q, want %q", decompressor.Comment, "comment")
+			}
+			if string(decompressor.Extra) != "extra" {
+				t.Fatalf("extra is %q, want %q", decompressor.Extra, "extra")
+			}
+			if decompressor.Mtime != 1e8 {
+				t.Fatalf("mtime is %d, want %d", decompressor.Mtime, uint32(1e8))
+			}
+			if decompressor.Name != "name" {
+				t.Fatalf("name is %q, want %q", decompressor.Name, "name")
+			}
+		})
+}