{fetch,upload}-pack: sideband v2 fetch response

Currently, a response to a fetch request has sideband support only while
the packfile is being sent, meaning that the server cannot send notices
until the start of the packfile.

Extend sideband support in protocol v2 fetch responses to the whole
response. upload-pack will advertise it if the
uploadpack.allowsidebandall configuration variable is set, and
fetch-pack will automatically request it if advertised.

If the sideband is to be used throughout the whole response, upload-pack
will use it to send errors instead of prefixing a PKT-LINE payload with
"ERR ".

This will be tested in a subsequent patch.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/pkt-line.h b/pkt-line.h
index a8e92a4..ad9a4a2 100644
--- a/pkt-line.h
+++ b/pkt-line.h
@@ -162,6 +162,9 @@ struct packet_reader {
 
 	/* indicates if a line has been peeked */
 	int line_peeked;
+
+	unsigned use_sideband : 1;
+	const char *me;
 };
 
 /*
@@ -201,6 +204,7 @@ extern char packet_buffer[LARGE_PACKET_MAX];
 
 struct packet_writer {
 	int dest_fd;
+	unsigned use_sideband : 1;
 };
 
 void packet_writer_init(struct packet_writer *writer, int dest_fd);