Imported Upstream version 1.3upstream/1.3

1 files changed, 15 insertions, 0 deletions

diff --git a/src/pkg/compress/gzip/gunzip.go b/src/pkg/compress/gzip/gunzip.go
index 1fb9b0964..4f398b194 100644
--- a/src/pkg/compress/gzip/gunzip.go
+++ b/src/pkg/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