Subject: Re: [PATCH 3/3] commit-graph: don't consider "replace" objects with "verify"

From: Junio C Hamano <[email-masked]>
Date: Fri, 15 Oct 2021 09:18:45 -0700

Ævar Arnfjörð Bjarmason  <[email-masked]> writes:

> Extend the code added in d6538246d3d (commit-graph: not compatible
> with replace objects, 2018-08-20) which ignored replace objects in the
> "write" command to ignore it in the "verify" command too.
>
> We can just move this assignment to the cmd_commit_graph(), it
> dispatches to "write" and "verify", and we're unlikely to ever get a
> sub-command that would like to consider replace refs.
>
> This will make tests added in eddc1f556cd (mktag tests: test
> update-ref and reachable fsck, 2021-06-17) pass in combination with
> the "GIT_TEST_COMMIT_GRAPH" mode added in 859fdc0c3cf (commit-graph:
> define GIT_TEST_COMMIT_GRAPH, 2018-08-29), except that mode is
> currently broken (but is being fixed concurrently). See the discussion
> starting at [1].
>
> 1. https://lore.kernel.org/git/[email-masked]/
>
> Signed-off-by: Ævar Arnfjörð Bjarmason <[email-masked]>
> ---
>  builtin/commit-graph.c  | 2 +-
>  t/t5318-commit-graph.sh | 1 +
>  2 files changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
> index 3c3de3a156f..fb8e166a26f 100644
> --- a/builtin/commit-graph.c
> +++ b/builtin/commit-graph.c
> @@ -263,7 +263,6 @@ static int graph_write(int argc, const char **argv)
>  	    git_env_bool(GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS, 0))
>  		flags |= COMMIT_GRAPH_WRITE_BLOOM_FILTERS;
>  
> -	read_replace_refs = 0;
>  	odb = find_odb(the_repository, opts.obj_dir);
>  
>  	if (opts.reachable) {
> @@ -318,6 +317,7 @@ int cmd_commit_graph(int argc, const char **argv, const char *prefix)
>  	if (!argc)
>  		goto usage;
>  
> +	read_replace_refs = 0;
>  	save_commit_buffer = 0;
>  
>  	if (!strcmp(argv[0], "verify"))

OK.  The only question I have is if this deserves some kind of a
warning.  If the user has replacement defined and makes an explicit
request to work with the commit-graph, silently ignoring the request
instead of telling them why we are ignoring may lead to confusion.

	Side note.  It is a "question", not "objection".

Other than that, nicely done.

Thanks.

> diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
> index 88fbe004a38..84d122a7ae7 100755
> --- a/t/t5318-commit-graph.sh
> +++ b/t/t5318-commit-graph.sh
> @@ -385,6 +385,7 @@ test_expect_success 'replace-objects invalidates commit-graph' '
>  		git commit-graph write --reachable &&
>  		test_path_is_file .git/objects/info/commit-graph &&
>  		git replace HEAD~1 HEAD~2 &&
> +		graph_git_two_modes "commit-graph verify" &&
>  		git -c core.commitGraph=false log >expect &&
>  		git -c core.commitGraph=true log >actual &&
>  		test_cmp expect actual &&