From 5525bf7b0bf18b6f523f9ed91b8679bb55139e67 Mon Sep 17 00:00:00 2001 From: Derrick Stolee Date: Tue, 27 Aug 2019 15:30:37 -0400 Subject: [PATCH] upload-pack: fix race condition in error messages Test t5516-fetch-push.sh has a test 'deny fetch unreachable SHA1, allowtipsha1inwant=true' that checks stderr for a specific error string from the remote. In some build environments the error sent over the remote connection gets mingled with the error from the die() statement. Since both signals are being output to the same file descriptor (but from parent and child processes), the output we are matching with grep gets split. To reduce the risk of this failure, follow this process instead: 1. Write an error message to stderr. 2. Write an error message across the connection. 3. exit(1). This reorders the events so the error is written entirely before the client receives a message from the remote, removing the race condition. Signed-off-by: Derrick Stolee --- upload-pack.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/upload-pack.c b/upload-pack.c index 94751477ab2d1e..7824d369bee07f 100644 --- a/upload-pack.c +++ b/upload-pack.c @@ -801,11 +801,12 @@ static void check_non_tip(struct upload_pack_data *data) for (i = 0; i < data->want_obj.nr; i++) { struct object *o = data->want_obj.objects[i].item; if (!is_our_ref(o, data->allow_uor)) { + warning("git upload-pack: not our ref %s", + oid_to_hex(&o->oid)); packet_writer_error(&data->writer, "upload-pack: not our ref %s", oid_to_hex(&o->oid)); - die("git upload-pack: not our ref %s", - oid_to_hex(&o->oid)); + exit(1); } } }