plumbing: protocol/packp, Decode push options in update request

Signed-off-by: Nikolas Sepos <nikolas.sepos@gmail.com>

plumbing/protocol/packp/updreq_decode.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/go-git/go-git/v5/plumbing"
 	"github.com/go-git/go-git/v5/plumbing/format/pktline"
+	"github.com/go-git/go-git/v5/plumbing/protocol/packp/capability"
 )
 
 var (
@@ -74,6 +75,11 @@ func errMalformedCommand(err error) error {
 		"malformed command: %s", err.Error()))
 }
 
+func errInvalidPushOption(err error) error {
+	return errMalformedRequest(fmt.Sprintf(
+		"invalid push option: %s", err.Error()))
+}
+
 // Decode reads the next update-request message form the reader and wr
 func (req *ReferenceUpdateRequest) Decode(r io.Reader) error {
 	var rc io.ReadCloser
@@ -100,6 +106,7 @@ func (d *updReqDecoder) Decode(req *ReferenceUpdateRequest) error {
 		d.decodeShallow,
 		d.decodeCommandAndCapabilities,
 		d.decodeCommands,
+		d.decodePushOptions,
 		d.setPackfile,
 		req.validate,
 	}
@@ -201,6 +208,35 @@ func (d *updReqDecoder) setPackfile() error {
 	return nil
 }
 
+func (d *updReqDecoder) decodePushOptions() error {
+	if !d.req.Capabilities.Supports(capability.PushOptions) {
+		return nil
+	}
+
+	if ok := d.s.Scan(); !ok {
+		return d.s.Err()
+	}
+
+	for {
+		b := d.s.Bytes()
+
+		if bytes.Equal(b, pktline.Flush) {
+			return nil
+		}
+
+		o, err := parsePushOption(b)
+		if err != nil {
+			return err
+		}
+
+		d.req.Options = append(d.req.Options, o)
+
+		if ok := d.s.Scan(); !ok {
+			return d.s.Err()
+		}
+	}
+}
+
 func parseCommand(b []byte) (*Command, error) {
 	if len(b) < minCommandLength {
 		return nil, errInvalidCommandLineLength(len(b))
@@ -247,3 +283,17 @@ func (d *updReqDecoder) scanErrorOr(origErr error) error {
 
 	return origErr
 }
+
+func parsePushOption(b []byte) (*Option, error) {
+	i := bytes.IndexByte(b, '=')
+	if i == -1 {
+		return &Option{Key: string(b)}, nil
+	}
+	if i == 0 {
+		return nil, errInvalidPushOption(errors.New("empty option key"))
+	}
+	if i == len(b)-1 {
+		return &Option{Key: string(b[:i])}, nil
+	}
+	return &Option{Key: string(b[:i]), Value: string(b[i+1:])}, nil
+}

plumbing/protocol/packp/updreq_decode_test.go

@@ -260,6 +260,50 @@ func (s *UpdReqDecodeSuite) TestWithPackfile(c *C) {
 	s.testDecodeOkRaw(c, expected, buf.Bytes())
 }
 
+func (s *UpdReqDecodeSuite) TestPushOptions(c *C) {
+	hash1 := plumbing.NewHash("1ecf0ef2c2dffb796033e5a02219af86ec6584e5")
+	hash2 := plumbing.NewHash("2ecf0ef2c2dffb796033e5a02219af86ec6584e5")
+
+	expected := NewReferenceUpdateRequest()
+	expected.Commands = []*Command{
+		{Name: plumbing.ReferenceName("myref1"), Old: hash1, New: hash2},
+	}
+	expected.Capabilities.Add("push-options")
+	expected.Options = append(expected.Options, &Option{Key: "key1", Value: "value1"})
+	expected.Options = append(expected.Options, &Option{Key: "key2", Value: "value2"})
+	expected.Options = append(expected.Options, &Option{Key: "key3", Value: ""})
+	expected.Options = append(expected.Options, &Option{Key: "key4", Value: ""})
+	expected.Packfile = io.NopCloser(bytes.NewReader([]byte{}))
+
+	payloads := []string{
+		"1ecf0ef2c2dffb796033e5a02219af86ec6584e5 2ecf0ef2c2dffb796033e5a02219af86ec6584e5 myref1\x00push-options",
+		pktline.FlushString,
+		"key1=value1",
+		"key2=value2",
+		"key3",
+		"key4=",
+		pktline.FlushString,
+	}
+
+	s.testDecodeOkExpected(c, expected, payloads)
+}
+
+func (s *UpdReqDecodeSuite) TestInvalidPushOptionMissingKey(c *C) {
+	payloads := []string{
+		"1ecf0ef2c2dffb796033e5a02219af86ec6584e5 2ecf0ef2c2dffb796033e5a02219af86ec6584e5 myref1\x00push-options",
+		pktline.FlushString,
+		"=value",
+		pktline.FlushString,
+	}
+
+	var buf bytes.Buffer
+	e := pktline.NewEncoder(&buf)
+	err := e.EncodeString(payloads...)
+	c.Assert(err, IsNil)
+
+	s.testDecoderErrorMatches(c, &buf, "^malformed request: invalid push option: empty option key")
+}
+
 func (s *UpdReqDecodeSuite) testDecoderErrorMatches(c *C, input io.Reader, pattern string) {
 	r := NewReferenceUpdateRequest()
 	c.Assert(r.Decode(input), ErrorMatches, pattern)

plumbing/transport/server/server.go

@@ -367,6 +367,10 @@ func (*rpSession) setSupportedCapabilities(c *capability.List) error {
 		return err
 	}
 
+	if err := c.Set(capability.PushOptions); err != nil {
+		return err
+	}
+
 	return c.Set(capability.ReportStatus)
 }