11 files changed, 65 insertions, 15 deletions
diff --git a/libgo/go/compress/bzip2/bzip2_test.go b/libgo/go/compress/bzip2/bzip2_test.go
index cd647e5..727249d 100644
--- a/libgo/go/compress/bzip2/bzip2_test.go
+++ b/libgo/go/compress/bzip2/bzip2_test.go
@@ -177,7 +177,7 @@ const (
 
 var testfiles = []string{
 	// Digits is the digits of the irrational number e. Its decimal representation
-	// does not repeat, but there are only 10 posible digits, so it should be
+	// does not repeat, but there are only 10 possible digits, so it should be
 	// reasonably compressible.
 	digits: "testdata/e.txt.bz2",
 	// Twain is Project Gutenberg's edition of Mark Twain's classic English novel.
diff --git a/libgo/go/compress/flate/inflate.go b/libgo/go/compress/flate/inflate.go
index bbe4c5a..ce4923e 100644
--- a/libgo/go/compress/flate/inflate.go
+++ b/libgo/go/compress/flate/inflate.go
@@ -54,7 +54,7 @@ func (e *WriteError) Error() string {
 	return "flate: write error at offset " + strconv.FormatInt(e.Offset, 10) + ": " + e.Err.Error()
 }
 
-// Note that much of the implemenation of huffmanDecoder is also copied
+// Note that much of the implementation of huffmanDecoder is also copied
 // into gen.go (in package main) for the purpose of precomputing the
 // fixed huffman tables so they can be included statically.
 
diff --git a/libgo/go/compress/flate/reader_test.go b/libgo/go/compress/flate/reader_test.go
index 2a8ebbc..a62ef74 100644
--- a/libgo/go/compress/flate/reader_test.go
+++ b/libgo/go/compress/flate/reader_test.go
@@ -29,7 +29,7 @@ const (
 
 var testfiles = []string{
 	// Digits is the digits of the irrational number e. Its decimal representation
-	// does not repeat, but there are only 10 posible digits, so it should be
+	// does not repeat, but there are only 10 possible digits, so it should be
 	// reasonably compressible.
 	digits: "../testdata/e.txt",
 	// Twain is Project Gutenberg's edition of Mark Twain's classic English novel.
diff --git a/libgo/go/compress/gzip/gunzip.go b/libgo/go/compress/gzip/gunzip.go
index 1fb9b09..4f398b1 100644
--- a/libgo/go/compress/gzip/gunzip.go
+++ b/libgo/go/compress/gzip/gunzip.go
@@ -89,6 +89,21 @@ func NewReader(r io.Reader) (*Reader, error) {
 	return z, nil
 }
 
+// Reset discards the Reader z's state and makes it equivalent to the
+// result of its original state from NewReader, but reading from r instead.
+// This permits reusing a Reader rather than allocating a new one.
+func (z *Reader) Reset(r io.Reader) error {
+	z.r = makeReader(r)
+	if z.digest == nil {
+		z.digest = crc32.NewIEEE()
+	} else {
+		z.digest.Reset()
+	}
+	z.size = 0
+	z.err = nil
+	return z.readHeader(true)
+}
+
 // 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
diff --git a/libgo/go/compress/gzip/gunzip_test.go b/libgo/go/compress/gzip/gunzip_test.go
index 5615373..2471038 100644
--- a/libgo/go/compress/gzip/gunzip_test.go
+++ b/libgo/go/compress/gzip/gunzip_test.go
@@ -303,6 +303,26 @@ func TestDecompressor(t *testing.T) {
 		if s != tt.raw {
 			t.Errorf("%s: got %d-byte %q want %d-byte %q", tt.name, n, s, len(tt.raw), tt.raw)
 		}
+
+		// Test Reader Reset.
+		in = bytes.NewReader(tt.gzip)
+		err = gzip.Reset(in)
+		if err != nil {
+			t.Errorf("%s: Reset: %s", tt.name, err)
+			continue
+		}
+		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)
+		}
 	}
 }
 
@@ -333,3 +353,17 @@ func TestIssue6550(t *testing.T) {
 		// ok
 	}
 }
+
+func TestInitialReset(t *testing.T) {
+	var r Reader
+	if err := r.Reset(bytes.NewReader(gunzipTests[1].gzip)); err != nil {
+		t.Error(err)
+	}
+	var buf bytes.Buffer
+	if _, err := io.Copy(&buf, &r); err != nil {
+		t.Error(err)
+	}
+	if s := buf.String(); s != gunzipTests[1].raw {
+		t.Errorf("got %q want %q", s, gunzipTests[1].raw)
+	}
+}
diff --git a/libgo/go/compress/gzip/gzip.go b/libgo/go/compress/gzip/gzip.go
index fe32d68..3a0bf54 100644
--- a/libgo/go/compress/gzip/gzip.go
+++ b/libgo/go/compress/gzip/gzip.go
@@ -22,8 +22,8 @@ const (
 	DefaultCompression = flate.DefaultCompression
 )
 
-// A Writer is an io.WriteCloser that satisfies writes by compressing data written
-// to its wrapped io.Writer.
+// A Writer is an io.WriteCloser.
+// Writes to a Writer are compressed and written to w.
 type Writer struct {
 	Header
 	w           io.Writer
@@ -37,8 +37,8 @@ type Writer struct {
 	err         error
 }
 
-// NewWriter creates a new Writer that satisfies writes by compressing data
-// written to w.
+// NewWriter returns a new Writer.
+// Writes to the returned writer are compressed and written to w.
 //
 // It is the caller's responsibility to call Close on the WriteCloser when done.
 // Writes may be buffered and not flushed until Close.
diff --git a/libgo/go/compress/lzw/reader.go b/libgo/go/compress/lzw/reader.go
index efbc758..ef59699 100644
--- a/libgo/go/compress/lzw/reader.go
+++ b/libgo/go/compress/lzw/reader.go
@@ -216,8 +216,8 @@ func (d *decoder) Close() error {
 	return nil
 }
 
-// NewReader creates a new io.ReadCloser that satisfies reads by decompressing
-// the data read from r.
+// NewReader creates a new io.ReadCloser.
+// Reads from the returned io.ReadCloser read and decompress data from r.
 // It is the caller's responsibility to call Close on the ReadCloser when
 // finished reading.
 // The number of bits to use for literal codes, litWidth, must be in the
diff --git a/libgo/go/compress/lzw/writer.go b/libgo/go/compress/lzw/writer.go
index b206918..961b25f 100644
--- a/libgo/go/compress/lzw/writer.go
+++ b/libgo/go/compress/lzw/writer.go
@@ -225,8 +225,8 @@ func (e *encoder) Close() error {
 	return e.w.Flush()
 }
 
-// NewWriter creates a new io.WriteCloser that satisfies writes by compressing
-// the data and writing it to w.
+// NewWriter creates a new io.WriteCloser.
+// Writes to the returned io.WriteCloser are compressed and written to w.
 // It is the caller's responsibility to call Close on the WriteCloser when
 // finished writing.
 // The number of bits to use for literal codes, litWidth, must be in the
diff --git a/libgo/go/compress/zlib/reader.go b/libgo/go/compress/zlib/reader.go
index d54746f..9e1aafd 100644
--- a/libgo/go/compress/zlib/reader.go
+++ b/libgo/go/compress/zlib/reader.go
@@ -51,7 +51,8 @@ type reader struct {
 	scratch      [4]byte
 }
 
-// NewReader creates a new io.ReadCloser that satisfies reads by decompressing data read from r.
+// NewReader creates a new io.ReadCloser.
+// Reads from the returned io.ReadCloser read and decompress data from r.
 // The implementation buffers input and may read more data than necessary from r.
 // It is the caller's responsibility to call Close on the ReadCloser when done.
 func NewReader(r io.Reader) (io.ReadCloser, error) {
diff --git a/libgo/go/compress/zlib/writer.go b/libgo/go/compress/zlib/writer.go
index 99ff654..fac7e15 100644
--- a/libgo/go/compress/zlib/writer.go
+++ b/libgo/go/compress/zlib/writer.go
@@ -34,8 +34,8 @@ type Writer struct {
 	wroteHeader bool
 }
 
-// NewWriter creates a new Writer that satisfies writes by compressing data
-// written to w.
+// NewWriter creates a new Writer.
+// Writes to the returned Writer are compressed and written to w.
 //
 // It is the caller's responsibility to call Close on the WriteCloser when done.
 // Writes may be buffered and not flushed until Close.
diff --git a/libgo/go/compress/zlib/writer_test.go b/libgo/go/compress/zlib/writer_test.go
index cf9c832..71ba81a 100644
--- a/libgo/go/compress/zlib/writer_test.go
+++ b/libgo/go/compress/zlib/writer_test.go
@@ -120,7 +120,7 @@ func testFileLevelDictReset(t *testing.T, fn string, level int, dict []byte) {
 	}
 	out := buf.String()
 
-	// Reset and comprses again.
+	// Reset and compress again.
 	buf2 := new(bytes.Buffer)
 	zlibw.Reset(buf2)
 	_, err = zlibw.Write(b0)