plumbing/protocol: paktp avoid duplication of haves, wants and shallow (#158)

1 files changed, 11 insertions, 0 deletions

diff --git a/plumbing/protocol/packp/uppackreq.go b/plumbing/protocol/packp/uppackreq.go
index 2b1cb84..887d27a 100644
--- a/plumbing/protocol/packp/uppackreq.go
+++ b/plumbing/protocol/packp/uppackreq.go
@@ -1,6 +1,7 @@
 package packp
 
 import (
+	"bytes"
 	"fmt"
 	"io"
 
@@ -68,10 +69,20 @@ type UploadHaves struct {
 // Encode encodes the UploadHaves into the Writer.
 func (u *UploadHaves) Encode(w io.Writer) error {
 	e := pktline.NewEncoder(w)
+
+	plumbing.HashesSort(u.Haves)
+
+	var last plumbing.Hash
 	for _, have := range u.Haves {
+		if bytes.Compare(last[:], have[:]) == 0 {
+			continue
+		}
+
 		if err := e.Encodef("have %s\n", have); err != nil {
 			return fmt.Errorf("sending haves for %q: %s", have, err)
 		}
+
+		last = have
 	}
 
 	if len(u.Haves) != 0 {