Re: [PATCH v2] fetch: remove fetch_if_missing=0

From: Junio C Hamano <gitster@pobox.com>
To: Jonathan Tan <jonathantanmy@google.com>
Cc: git@vger.kernel.org, jrnieder@gmail.com, sunshine@sunshineco.com
Subject: Re: [PATCH v2] fetch: remove fetch_if_missing=0
Date: Wed, 06 Nov 2019 10:45:08 +0900	[thread overview]
Message-ID: <xmqq7e4dydzv.fsf@gitster-ct.c.googlers.com> (raw)
In-Reply-To: <20191105185619.207173-1-jonathantanmy@google.com> (Jonathan Tan's message of "Tue, 5 Nov 2019 10:56:19 -0800")

Jonathan Tan <jonathantanmy@google.com> writes:

> In fetch_pack() (and all functions it calls), pass
> OBJECT_INFO_SKIP_FETCH_OBJECT whenever we query an object that could be
> a tree or blob that we do not want to be lazy-fetched even if it is
> absent. Thus, the only lazy-fetches occurring for trees and blobs are
> when resolving deltas.
>
> Thus, we can remove fetch_if_missing=0 from builtin/fetch.c. Remove
> this, and also add a test ensuring that such objects are not
> lazy-fetched. (We might be able to remove fetch_if_missing=0 from other
> places too, but I have limited myself to builtin/fetch.c in this commit
> because I have not written tests for the other commands yet.)
>
> Note that commits and tags may still be lazy-fetched. I limited myself
> to objects that could be trees or blobs here because Git does not
> support creating such commit- and tag-excluding clones yet, and even if
> such a clone were manually created, Git does not have good support for
> fetching a single commit (when fetching a commit, it and all its
> ancestors would be sent).
>
> Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
> ---
> Changes from v1:
> - Added NEEDSWORK in test, suggested by Jonathan Nieder
> - Used printf in test, suggested by Eric Sunshine

Nice.  The less we use big "plug the machinery to lazily fetch for
now" switch, the better, I think.

> +setup_triangle () {
> +	rm -rf big-blob.txt server client promisor-remote &&
> +
> +	printf "line %d\n" $(test_seq 1 100) >big-blob.txt

I'll tweak this line while queueing with a trailing " &&" (no need
to resend only for this).