Merge branch 'pktline-bytes-written' into 'master'

Fix "bytes written" count in pktline.WriteString

See merge request gitlab-org/gitaly!1129

3 files changed, 12 insertions, 6 deletions

diff --git a/changelogs/unreleased/pktline-bytes-written.yml b/changelogs/unreleased/pktline-bytes-written.yml
new file mode 100644
index 000000000..8caccbe2d
--- /dev/null
+++ b/changelogs/unreleased/pktline-bytes-written.yml
@@ -0,0 +1,5 @@
+---
+title: Fix "bytes written" count in pktline.WriteString
+merge_request: 1129
+author:
+type: fixed
diff --git a/internal/git/pktline/pkt_line_test.go b/internal/git/pktline/pkt_line_test.go
index 25e2e799d..3024a31d1 100644
--- a/internal/git/pktline/pkt_line_test.go
+++ b/internal/git/pktline/pkt_line_test.go
@@ -138,14 +138,16 @@ func TestWriteString(t *testing.T) {
 	for _, tc := range testCases {
 		t.Run(tc.desc, func(t *testing.T) {
 			w := &bytes.Buffer{}
-			_, err := WriteString(w, tc.in)
+			n, err := WriteString(w, tc.in)
 
 			if tc.fail {
 				require.Error(t, err)
-			} else {
-				require.NoError(t, err)
+				return
 			}
 
+			require.NoError(t, err)
+			require.Equal(t, len(tc.in), n, "number of bytes written reported by WriteString")
+
 			require.Equal(t, tc.out, w.String())
 		})
 	}
diff --git a/internal/git/pktline/pktline.go b/internal/git/pktline/pktline.go
index 8cb59239b..75eb490f9 100644
--- a/internal/git/pktline/pktline.go
+++ b/internal/git/pktline/pktline.go
@@ -3,8 +3,6 @@ package pktline
 // Utility functions for working with the Git pkt-line format. See
 // https://github.com/git/git/blob/master/Documentation/technical/protocol-common.txt
 
-// TODO add tests https://gitlab.com/gitlab-org/gitaly/issues/1340
-
 import (
 	"bufio"
 	"bytes"
@@ -49,7 +47,8 @@ func WriteString(w io.Writer, str string) (int, error) {
 		return 0, fmt.Errorf("string too large: %d bytes", len(str))
 	}
 
-	return fmt.Fprintf(w, "%04x%s", pktLen, str)
+	_, err := fmt.Fprintf(w, "%04x%s", pktLen, str)
+	return len(str), err
 }
 
 // WriteFlush writes a pkt flush packet.