[RFC PATCH 2/2] fetch-pack.c: pass "oi_flags" to lookup_commit_in_graph()

[Han Xin <hanxin.hx@bytedance.com>]

As the custom "oi_flags" is missed by lookup_commit_in_graph(), we will
get another lazy fetch round if we found the commit in commit graph but
miss it in the local object repository.

We can see the issue via[1].

1. https://lore.kernel.org/git/20220612161707.21807-1-chiyutianyi@gmail.com/

Signed-off-by: Han Xin <hanxin.hx@bytedance.com>
---
 fetch-pack.c                       | 10 +++----
 t/t5583-fetch-with-commit-graph.sh | 47 ++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 5 deletions(-)
 create mode 100644 t/t5583-fetch-with-commit-graph.sh

diff --git a/fetch-pack.c b/fetch-pack.c
index 4a62fb182e..ca1234e456 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -123,7 +123,7 @@ static struct commit *deref_without_lazy_fetch_extended(const struct object_id *
 	struct object_info info = { .typep = type };
 	struct commit *commit;
 
-	commit = lookup_commit_in_graph(the_repository, oid, 0);
+	commit = lookup_commit_in_graph(the_repository, oid, oi_flags);
 	if (commit)
 		return commit;
 
@@ -704,6 +704,7 @@ static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
 	struct ref *ref;
 	int old_save_commit_buffer = save_commit_buffer;
 	timestamp_t cutoff = 0;
+	int oi_flags = OBJECT_INFO_SKIP_FETCH_OBJECT | OBJECT_INFO_QUICK;
 
 	if (args->refetch)
 		return;
@@ -714,13 +715,12 @@ static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
 	for (ref = *refs; ref; ref = ref->next) {
 		struct commit *commit;
 
-		commit = lookup_commit_in_graph(the_repository, &ref->old_oid, 0);
+		commit = lookup_commit_in_graph(the_repository, &ref->old_oid,
+						oi_flags);
 		if (!commit) {
 			struct object *o;
 
-			if (!has_object_file_with_flags(&ref->old_oid,
-						OBJECT_INFO_QUICK |
-						OBJECT_INFO_SKIP_FETCH_OBJECT))
+			if (!has_object_file_with_flags(&ref->old_oid, oi_flags))
 				continue;
 			o = parse_object(the_repository, &ref->old_oid);
 			if (!o || o->type != OBJ_COMMIT)
diff --git a/t/t5583-fetch-with-commit-graph.sh b/t/t5583-fetch-with-commit-graph.sh
new file mode 100644
index 0000000000..cb2beafa8d
--- /dev/null
+++ b/t/t5583-fetch-with-commit-graph.sh
@@ -0,0 +1,47 @@
+#!/bin/sh
+
+test_description='test for fetching missing object with a full commit-graph'
+
+GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
+export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	git init --bare dest.git &&
+	test_commit one &&
+	git checkout -b testbranch &&
+	test_commit two &&
+	git push dest.git --all
+'
+
+test_expect_success 'prepare a alternates repository without testbranch' '
+	git clone -b $GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME dest.git alternates &&
+	oid=$(git -C alternates rev-parse refs/remotes/origin/testbranch) &&
+	git -C alternates update-ref -d refs/remotes/origin/testbranch &&
+	git -C alternates gc --prune=now
+'
+
+test_expect_success 'prepare a repository with a full commit-graph' '
+	git init source &&
+	echo "$(pwd)/dest.git/objects" >source/.git/objects/info/alternates &&
+	git -C source remote add origin "$(pwd)/dest.git" &&
+	git -C source config remote.origin.promisor true &&
+	git -C source config remote.origin.partialclonefilter blob:none &&
+	git -C source fetch origin &&
+	(
+		cd source &&
+		test_commit three &&
+		git -c gc.writeCommitGraph=true gc
+	)
+'
+
+test_expect_success 'change the alternates to that without commit two' '
+	echo "$(pwd)/alternates/.git/objects" >source/.git/objects/info/alternates
+'
+
+test_expect_success 'fetch the missing object' '
+	git -C source fetch origin $oid
+'
+
+test_done
-- 
2.36.1