patch, 3 partscommit-graph: make "verify" work with replace refs

> The graph_git_two_modes() helper added in 177722b3442 (commit:
> integrate commit graph with commit parsing, 2018-04-10) didn't
> &&-chain its "git commit-graph" invocations, which as can be seen with
> SANITIZE=leak will happily mark tests as passing if both of these
> commands die, since test_cmp() will be comparing two empty files.

> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> ---
>  t/t5318-commit-graph.sh | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
> index 295c5bd94d2..88fbe004a38 100755
> --- a/t/t5318-commit-graph.sh
> +++ b/t/t5318-commit-graph.sh
> @@ -70,8 +70,8 @@ test_expect_success 'create commits and repack' '
>  '
>  
>  graph_git_two_modes() {
> -	git -c core.commitGraph=true $1 >output
> -	git -c core.commitGraph=false $1 >expect
> +	git -c core.commitGraph=true $1 >output &&
> +	git -c core.commitGraph=false $1 >expect &&
>  	test_cmp expect output
>  }

> In 135a7123755 (commit-graph: add --split option to builtin,
> 2019-06-18) this function was copy/pasted to the split commit-graph
> tests, as in the preceding commit we need to fix this to use
> &&-chaining, so it won't be hiding errors.
>
> Unlike its sister function in "t5318-commit-graph.sh", which we got
> lucky with, this one was hiding a real test failure. A tests added in
> c523035cbd8 (commit-graph: allow cross-alternate chains, 2019-06-18)
> has never worked as intended. Unlike most other graph_git_behavior
> uses in this file it clones the repository into a sub-directory, so
> we'll need to refer to "commits/6" as "origin/commits/6".

>  graph_git_two_modes() {
> -	git -c core.commitGraph=true $1 >output
> -	git -c core.commitGraph=false $1 >expect
> +	git ${2:+ -C "$2"} -c core.commitGraph=true $1 >output &&
> +	git ${2:+ -C "$2"} -c core.commitGraph=false $1 >expect &&

>  	test_cmp expect output
>  }
>  
> @@ -64,12 +64,13 @@ graph_git_behavior() {
>  	MSG=$1
>  	BRANCH=$2
>  	COMPARE=$3
> +	DIR=$4
>  	test_expect_success "check normal git operations: $MSG" '
> -		graph_git_two_modes "log --oneline $BRANCH" &&
> -		graph_git_two_modes "log --topo-order $BRANCH" &&
> -		graph_git_two_modes "log --graph $COMPARE..$BRANCH" &&
> -		graph_git_two_modes "branch -vv" &&
> -		graph_git_two_modes "merge-base -a $BRANCH $COMPARE"
> +		graph_git_two_modes "log --oneline $BRANCH" "$DIR" &&
> +		graph_git_two_modes "log --topo-order $BRANCH" "$DIR" &&
> +		graph_git_two_modes "log --graph $COMPARE..$BRANCH" "$DIR" &&
> +		graph_git_two_modes "branch -vv" "$DIR" &&
> +		graph_git_two_modes "merge-base -a $BRANCH $COMPARE" "$DIR"
>  	'
>  }
>  
> @@ -187,7 +188,10 @@ test_expect_success 'create fork and chain across alternate' '
>  	)
>  '
>  
> -graph_git_behavior 'alternate: commit 13 vs 6' commits/13 commits/6
> +if test -d fork
> +then
> +	graph_git_behavior 'alternate: commit 13 vs 6' commits/13 origin/commits/6 "fork"
> +fi
>  
>  test_expect_success 'test merge stragety constants' '
>  	git clone . merge-2 &&

> 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/87wnmihswp.fsf@evledraar.gmail.com/
>
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> ---
>  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"))

> 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 &&