From df9514a1384336f6a7089063f94dabd3f2379819 Mon Sep 17 00:00:00 2001
From: Taylor Blau <me@ttaylorr.com>
Date: Mon, 7 Nov 2016 14:06:44 -0700
Subject: [PATCH] git: return number of bytes accepted, not written

---
 git/packet_writer.go      | 23 +++++++++++------------
 git/packet_writer_test.go | 16 ++++++++--------
 2 files changed, 19 insertions(+), 20 deletions(-)

diff --git a/git/packet_writer.go b/git/packet_writer.go
index 7a8a80ed..3aa4ca6a 100644
--- a/git/packet_writer.go
+++ b/git/packet_writer.go
@@ -45,9 +45,11 @@ func NewPacketWriter(w io.Writer, c int) *PacketWriter {
 // the remaining data in the buffer, and write the terminating bytes to the
 // underlying packet stream.
 //
-// Write returns the number of bytes in "p" actually written to the underlying
-// protocol stream, not including the number of bytes written in those packets
-// headers. If any error was encountered while either buffering or writing, that
+// Write returns the number of bytes in "p" accepted into the writer, which
+// _MAY_ be written to the underlying protocol stream, or may be written into
+// the internal buffer.
+//
+// If any error was encountered while either buffering or writing, that
 // error is returned, along with the number of bytes written to the underlying
 // protocol stream, as described above.
 func (w *PacketWriter) Write(p []byte) (int, error) {
@@ -58,15 +60,12 @@ func (w *PacketWriter) Write(p []byte) (int, error) {
 		// stored in the buffer, and then write the a packet termination
 		// sequence.
 
-		flushed, err := w.flush()
-		if err != nil {
+		if _, err := w.flush(); err != nil {
 			return 0, err
 		}
 
-		n = n + flushed
-
-		if err = w.proto.writeFlush(); err != nil {
-			return n, err
+		if err := w.proto.writeFlush(); err != nil {
+			return 0, err
 		}
 	}
 
@@ -83,16 +82,16 @@ func (w *PacketWriter) Write(p []byte) (int, error) {
 		// have in the internal buffer.
 		p = p[m:]
 
+		n = n + m
+
 		if len(w.buf) == MaxPacketLength {
 			// If we were able to grab an entire packet's worth of
 			// data, flush the buffer.
 
-			flushed, err := w.flush()
-			if err != nil {
+			if _, err := w.flush(); err != nil {
 				return n, err
 			}
 
-			n = n + flushed
 		}
 	}
 
diff --git a/git/packet_writer_test.go b/git/packet_writer_test.go
index ed1c22ff..10d205af 100644
--- a/git/packet_writer_test.go
+++ b/git/packet_writer_test.go
@@ -12,8 +12,8 @@ func TestPacketWriterWritesPacketsShorterThanMaxPacketSize(t *testing.T) {
 	var buf bytes.Buffer
 
 	w := NewPacketWriter(&buf, 0)
-	assertWriterWrite(t, w, []byte("Hello, world!"), 0)
-	assertWriterWrite(t, w, nil, len("Hello, world!"))
+	assertWriterWrite(t, w, []byte("Hello, world!"), 13)
+	assertWriterWrite(t, w, nil, 0)
 
 	proto := newProtocolRW(&buf, nil)
 	assertPacketRead(t, proto, []byte("Hello, world!"))
@@ -45,9 +45,9 @@ func TestPacketWriterWritesMultiplePacketsLessThanMaxPacketLength(t *testing.T)
 	var buf bytes.Buffer
 
 	w := NewPacketWriter(&buf, 0)
-	assertWriterWrite(t, w, []byte("first\n"), 0)
-	assertWriterWrite(t, w, []byte("second"), 0)
-	assertWriterWrite(t, w, nil, len("first\nsecond"))
+	assertWriterWrite(t, w, []byte("first\n"), len("first\n"))
+	assertWriterWrite(t, w, []byte("second"), len("second"))
+	assertWriterWrite(t, w, nil, 0)
 
 	proto := newProtocolRW(&buf, nil)
 	assertPacketRead(t, proto, []byte("first\nsecond"))
@@ -72,9 +72,9 @@ func TestPacketWriterWritesMultiplePacketsGreaterThanMaxPacketLength(t *testing.
 	copy(p2, b1)
 
 	w := NewPacketWriter(&buf, 0)
-	assertWriterWrite(t, w, p1, 0)
-	assertWriterWrite(t, w, p2, MaxPacketLength)
-	assertWriterWrite(t, w, nil, (len(b1)+len(b2))-MaxPacketLength)
+	assertWriterWrite(t, w, p1, len(p1))
+	assertWriterWrite(t, w, p2, len(p2))
+	assertWriterWrite(t, w, nil, 0)
 
 	// offs is how far into b2 we needed to buffer before writing an entire
 	// packet