Subject: Re: [PATCH 6/6] fetch-pack: fix deepen shallow over smart http with no-done cap

From: Junio C Hamano <[email-masked]>
Date: Thu, 06 Feb 2014 11:16:54 -0800

Nguyễn Thái Ngọc Duy  <[email-masked]> writes:

> In smart http, upload-pack adds new shallow lines at the beginning of
> each rpc response. Only shallow lines from the first rpc call are
> useful. After that they are thrown away. It's designed this way
> because upload-pack is stateless and has no idea when its shallow
> lines are helpful or not.
>
> So after refs are negotiated with multi_ack_detailed and both sides
> happy. The server sends "ACK obj-id ready", terminates the rpc call

Is the above "... and both sides are happy, the server sends ..."?
Lack of a verb makes it hard to guess.

> and waits for the final rpc round. The client sends "done". The server
> sends another response, which also has shallow lines at the beginning,
> and the last "ACK obj-id" line.
>
> When no-done is active, the last round is cut out, the server sends
> "ACK obj-id ready" and "ACK obj-id" in the same rpc
> response. fetch-pack is updated to recognize this and not send
> "done". However it still tries to consume shallow lines, which are
> never sent.
>
> Update the code, make sure to skip consuming shallow lines when
> no-done is enabled.
>
> Reported-by: Jeff King <[email-masked]>
> Signed-off-by: Nguyễn Thái Ngọc Duy <[email-masked]>
> ---

Thanks.

Do I understand the situation correctly if I said "The call to
consume-shallow-list has been here from the very beginning, but it
should have been adjusted like this patch when no-done was
introduced."?

>  fetch-pack.c             |  3 ++-
>  t/t5537-fetch-shallow.sh | 24 ++++++++++++++++++++++++
>  2 files changed, 26 insertions(+), 1 deletion(-)
>
> diff --git a/fetch-pack.c b/fetch-pack.c
> index 90fdd49..f061f1f 100644
> --- a/fetch-pack.c
> +++ b/fetch-pack.c
> @@ -439,7 +439,8 @@ done:
>  	}
>  	strbuf_release(&req_buf);
>  
> -	consume_shallow_list(args, fd[0]);
> +	if (!got_ready || !no_done)
> +		consume_shallow_list(args, fd[0]);
>  	while (flushes || multi_ack) {
>  		int ack = get_ack(fd[0], result_sha1);
>  		if (ack) {
> diff --git a/t/t5537-fetch-shallow.sh b/t/t5537-fetch-shallow.sh
> index b0fa738..fb11073 100755
> --- a/t/t5537-fetch-shallow.sh
> +++ b/t/t5537-fetch-shallow.sh
> @@ -200,5 +200,29 @@ EOF
>  	)
>  '
>  
> +# This test is tricky. We need large enough "have"s that fetch-pack
> +# will put pkt-flush in between. Then we need a "have" the the server
> +# does not have, it'll send "ACK %s ready"
> +test_expect_success 'add more commits' '
> +	(
> +	cd shallow &&
> +	for i in $(seq 10); do
> +	git checkout --orphan unrelated$i &&
> +	test_commit unrelated$i >/dev/null &&
> +	git push -q "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" refs/heads/unrelated$i:refs/heads/unrelated$i
> +	git push -q ../clone/.git refs/heads/unrelated$i:refs/heads/unrelated$i
> +	done &&
> +	git checkout master &&
> +	test_commit new &&
> +	git push  "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" master
> +	) &&
> +	(
> +	cd clone &&
> +	git checkout --orphan newnew &&
> +	test_commit new-too &&
> +	git fetch --depth=2
> +	)
> +'
> +
>  stop_httpd
>  test_done