Re: [PATCH] fetch: no FETCH_HEAD display if --no-write-fetch-head

From: Junio C Hamano <gitster@pobox.com>
Date: Sep 2, 2020, 20:07 UTC
Message-ID: <xmqq7dtcaqob.fsf@gitster.c.googlers.com>
In-Reply-To: <20200902190232.317477-1-jonathantanmy@google.com>

Jonathan Tan <jonathantanmy@google.com> writes:

Show 5 quoted lines

> 887952b8c6 ("fetch: optionally allow disabling FETCH_HEAD update",
> 2020-08-18) introduced the ability to disable writing to FETCH_HEAD
> during fetch, but did not suppress the "<source> -> FETCH_HEAD" message
> when this ability is used. This message is misleading in this case,
> because FETCH_HEAD is not written.

Thanks for noticing, but I wonder if we should keep this for users of dry-run, which tends to give more output to what _would_ have been done if it were not dry-run?

> This might be important for Stolee's maintenance prefetch patch [1] too
> - presumably we don't want to show FETCH_HEAD there, as it would be
> misleading and would clutter in the same way (albeit to a lesser
> extent).

Yes, that makes sense.

Show 9 quoted lines

> Also, because "fetch" is used to
> lazy-fetch missing objects in a partial clone, this significantly
> clutters up the output in that case since the objects to be fetched are
> potentially numerous. Therefore, suppress this message when
> --no-write-fetch-head is passed.
>
> Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
> ---
> This is on origin/jt/lazy-fetch.

I think this patch, with possible correction for "we are not writing FETCH_HEAD but we do want to show what would have been done when the user asked --dry-run", should be done as a brown-paper-bag bugfix directly on jc/no-update-fetch-head topic and merged quicly down to 'master', instead of taken hostage of some other topic in flight, but it would soon already be a week since jt/lazy-fetch was merged to 'next', so it probably is OK to apply on jt/lazy-fetch, and it indeed is easier to manage that way.

Show 46 quoted lines

> [1] https://lore.kernel.org/git/da64c51a8182ec13aeed8f0157079fb29a09ee85.1598380599.git.gitgitgadget@gmail.com/
> ---
>  builtin/fetch.c          | 3 ++-
>  t/t0410-partial-clone.sh | 7 +++++--
>  2 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/builtin/fetch.c b/builtin/fetch.c
> index 320ba9471d..442df05f5a 100644
> --- a/builtin/fetch.c
> +++ b/builtin/fetch.c
> @@ -1023,11 +1023,12 @@ static int store_updated_refs(const char *raw_url, const char *remote_name,
>  				rc |= update_local_ref(ref, what, rm, &note,
>  						       summary_width);
>  				free(ref);
> -			} else
> +			} else if (write_fetch_head) {
>  				format_display(&note, '*',
>  					       *kind ? kind : "branch", NULL,
>  					       *what ? what : "HEAD",
>  					       "FETCH_HEAD", summary_width);
> +			}
>  			if (note.len) {
>  				if (verbosity >= 0 && !shown_url) {
>  					fprintf(stderr, _("From %.*s\n"),
> diff --git a/t/t0410-partial-clone.sh b/t/t0410-partial-clone.sh
> index d681e90640..584a039b85 100755
> --- a/t/t0410-partial-clone.sh
> +++ b/t/t0410-partial-clone.sh
> @@ -183,7 +183,7 @@ test_expect_success 'missing CLI object, but promised, passes fsck' '
>  '
>  
>  test_expect_success 'fetching of missing objects' '
> -	rm -rf repo &&
> +	rm -rf repo err &&
>  	test_create_repo server &&
>  	test_commit -C server foo &&
>  	git -C server repack -a -d --write-bitmap-index &&
> @@ -194,7 +194,10 @@ test_expect_success 'fetching of missing objects' '
>  
>  	git -C repo config core.repositoryformatversion 1 &&
>  	git -C repo config extensions.partialclone "origin" &&
> -	git -C repo cat-file -p "$HASH" &&
> +	git -C repo cat-file -p "$HASH" 2>err &&
> +
> +	# Ensure that no spurious FETCH_HEAD messages are written
> +	! grep FETCH_HEAD err &&

Test also --dry-run, but that perhaps needs to be done outside the context of partial-clone. The above "lazy fetching should be silent and should not bother users with mention of FETCH_HEAD" is good test in the context of partial-clone, though.

jc/no-update-fetch-head added its own test to t/t5510, and both the "output lacks FETCH_HEAD when --no-write-fetch-head is given" test and the "output still mentions FETCH_HEAD with --dry-run" test belong there.

Thanks.