[RFC/PATCH 1/5] upload-pack: only accept capabilities on the first "want" line

[Stefan Beller <sbeller@google.com>]

From: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>

pack-protocol.txt says so and fetch-pack also follows it even though
upload-pack is a bit lax. Fix it.

Signed-off-by: Stefan Beller <sbeller@google.com>
---
 upload-pack.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/upload-pack.c b/upload-pack.c
index e0ce2bf..d9230ba 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -558,6 +558,7 @@ static void receive_needs(void)
 	struct object_array shallows = OBJECT_ARRAY_INIT;
 	int depth = 0;
 	int has_non_tip = 0;
+	int first_want = 1;
 
 	shallow_nr = 0;
 	for (;;) {
@@ -596,7 +597,11 @@ static void receive_needs(void)
 			die("git upload-pack: protocol error, "
 			    "expected to get sha, not '%s'", line);
 
-		parse_features(line + 45);
+		if (first_want) {
+			parse_features(line + 45);
+			first_want = 0;
+		} else if (line[45])
+			die("garbage at the end of 'want' line %s", line + 45);
 
 		o = parse_object(sha1_buf);
 		if (!o)
-- 
2.3.0.81.gc37f363