zstd: free Decoder resources when Reset is called with a nil io.Reader

Attempt at fixing #296.
klauspost · Dec 26, 2020 · e44a8d1 · e44a8d1
1 parent bb5ba3d
commit e44a8d1
Showing 1 changed file with 7 additions and 3 deletions.
diff --git a/zstd/decoder.go b/zstd/decoder.go
@@ -156,8 +156,14 @@ func (d *Decoder) Reset(r io.Reader) error {
 	if d.current.err == ErrDecoderClosed {
 		return d.current.err
 	}
+
+	d.drainOutput()
+
 	if r == nil {
-		return errors.New("nil Reader sent as input")
+		d.current.b = []byte{}
+		d.current.err = io.EOF
+		d.current.flushed = true
+		return nil
 	}
 
 	if d.stream == nil {
@@ -166,8 +172,6 @@ func (d *Decoder) Reset(r io.Reader) error {
 		go d.startStreamDecoder(d.stream)
 	}
 
-	d.drainOutput()
-
 	// If bytes buffer and < 1MB, do sync decoding anyway.
 	if bb, ok := r.(*bytes.Buffer); ok && bb.Len() < 1<<20 {
 		if debug {