Convert lookup_commit* to struct object_id

Convert lookup_commit, lookup_commit_or_die,
lookup_commit_reference, and lookup_commit_reference_gently to take
struct object_id arguments.

Introduce a temporary in parse_object buffer in order to convert this
function.  This is required since in order to convert parse_object and
parse_object_buffer, lookup_commit_reference_gently and
lookup_commit_or_die would need to be converted.  Not introducing a
temporary would therefore require that lookup_commit_or_die take a
struct object_id *, but lookup_commit would take unsigned char *,
leaving a confusing and hard-to-use interface.

parse_object_buffer will lose this temporary in a later patch.

This commit was created with manual changes to commit.c, commit.h, and
object.c, plus the following semantic patch:

@@
expression E1, E2;
@@
- lookup_commit_reference_gently(E1.hash, E2)
+ lookup_commit_reference_gently(&E1, E2)

@@
expression E1, E2;
@@
- lookup_commit_reference_gently(E1->hash, E2)
+ lookup_commit_reference_gently(E1, E2)

@@
expression E1;
@@
- lookup_commit_reference(E1.hash)
+ lookup_commit_reference(&E1)

@@
expression E1;
@@
- lookup_commit_reference(E1->hash)
+ lookup_commit_reference(E1)

@@
expression E1;
@@
- lookup_commit(E1.hash)
+ lookup_commit(&E1)

@@
expression E1;
@@
- lookup_commit(E1->hash)
+ lookup_commit(E1)

@@
expression E1, E2;
@@
- lookup_commit_or_die(E1.hash, E2)
+ lookup_commit_or_die(&E1, E2)

@@
expression E1, E2;
@@
- lookup_commit_or_die(E1->hash, E2)
+ lookup_commit_or_die(E1, E2)

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

24 files changed, 54 insertions, 53 deletions

diff --git a/builtin/am.c b/builtin/am.c
index a95dd8b4e..650269ac5 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -1488,7 +1488,7 @@ static int parse_mail_rebase(struct am_state *state, const char *mail)
 	if (get_mail_commit_oid(&commit_oid, mail) < 0)
 		die(_("could not parse %s"), mail);
 
-	commit = lookup_commit_or_die(commit_oid.hash, mail);
+	commit = lookup_commit_or_die(&commit_oid, mail);
 
 	get_commit_info(state, commit);
 
@@ -1683,7 +1683,7 @@ static void do_commit(const struct am_state *state)
 
 	if (!get_sha1_commit("HEAD", parent.hash)) {
 		old_oid = &parent;
-		commit_list_insert(lookup_commit(parent.hash), &parents);
+		commit_list_insert(lookup_commit(&parent), &parents);
 	} else {
 		old_oid = NULL;
 		say(state, stderr, _("applying to an empty history"));
diff --git a/builtin/blame.c b/builtin/blame.c
index 7d644d092..58bb274d0 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -2253,7 +2253,7 @@ static struct commit_list **append_parent(struct commit_list **tail, const struc
 {
 	struct commit *parent;
 
-	parent = lookup_commit_reference(oid->hash);
+	parent = lookup_commit_reference(oid);
 	if (!parent)
 		die("no such commit %s", oid_to_hex(oid));
 	return &commit_list_insert(parent, tail)->next;
@@ -2475,7 +2475,7 @@ static const char *dwim_reverse_initial(struct scoreboard *sb)
 	/* Do we have HEAD? */
 	if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, head_oid.hash, NULL))
 		return NULL;
-	head_commit = lookup_commit_reference_gently(head_oid.hash, 1);
+	head_commit = lookup_commit_reference_gently(&head_oid, 1);
 	if (!head_commit)
 		return NULL;
 
diff --git a/builtin/branch.c b/builtin/branch.c
index 48a513a84..83fcda43d 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -124,7 +124,7 @@ static int branch_merged(int kind, const char *name,
 		    (reference_name = reference_name_to_free =
 		     resolve_refdup(upstream, RESOLVE_REF_READING,
 				    oid.hash, NULL)) != NULL)
-			reference_rev = lookup_commit_reference(oid.hash);
+			reference_rev = lookup_commit_reference(&oid);
 	}
 	if (!reference_rev)
 		reference_rev = head_rev;
@@ -157,7 +157,7 @@ static int check_branch_commit(const char *branchname, const char *refname,
 			       const struct object_id *oid, struct commit *head_rev,
 			       int kinds, int force)
 {
-	struct commit *rev = lookup_commit_reference(oid->hash);
+	struct commit *rev = lookup_commit_reference(oid);
 	if (!rev) {
 		error(_("Couldn't look up commit object for '%s'"), refname);
 		return -1;
@@ -211,7 +211,7 @@ static int delete_branches(int argc, const char **argv, int force, int kinds,
 	}
 
 	if (!force) {
-		head_rev = lookup_commit_reference(head_oid.hash);
+		head_rev = lookup_commit_reference(&head_oid);
 		if (!head_rev)
 			die(_("Couldn't look up commit object for HEAD"));
 	}
diff --git a/builtin/checkout.c b/builtin/checkout.c
index bfa5419f3..afa99fb8a 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -393,7 +393,7 @@ static int checkout_paths(const struct checkout_opts *opts,
 		die(_("unable to write new index file"));
 
 	read_ref_full("HEAD", 0, rev.hash, NULL);
-	head = lookup_commit_reference_gently(rev.hash, 1);
+	head = lookup_commit_reference_gently(&rev, 1);
 
 	errs |= post_checkout_hook(head, head, 0);
 	return errs;
@@ -833,7 +833,7 @@ static int switch_branches(const struct checkout_opts *opts,
 	int flag, writeout_error = 0;
 	memset(&old, 0, sizeof(old));
 	old.path = path_to_free = resolve_refdup("HEAD", 0, rev.hash, &flag);
-	old.commit = lookup_commit_reference_gently(rev.hash, 1);
+	old.commit = lookup_commit_reference_gently(&rev, 1);
 	if (!(flag & REF_ISSYMREF))
 		old.path = NULL;
 
@@ -1047,7 +1047,7 @@ static int parse_branchname_arg(int argc, const char **argv,
 	else
 		new->path = NULL; /* not an existing branch */
 
-	new->commit = lookup_commit_reference_gently(rev->hash, 1);
+	new->commit = lookup_commit_reference_gently(rev, 1);
 	if (!new->commit) {
 		/* not a commit */
 		*source_tree = parse_tree_indirect(rev->hash);
diff --git a/builtin/clone.c b/builtin/clone.c
index de85b8525..646f28792 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -682,7 +682,7 @@ static void update_head(const struct ref *our, const struct ref *remote,
 			install_branch_config(0, head, option_origin, our->name);
 		}
 	} else if (our) {
-		struct commit *c = lookup_commit_reference(our->old_oid.hash);
+		struct commit *c = lookup_commit_reference(&our->old_oid);
 		/* --branch specifies a non-branch (i.e. tags), detach HEAD */
 		update_ref(msg, "HEAD", c->object.oid.hash,
 			   NULL, REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
diff --git a/builtin/commit-tree.c b/builtin/commit-tree.c
index 605017261..f39c2b273 100644
--- a/builtin/commit-tree.c
+++ b/builtin/commit-tree.c
@@ -58,7 +58,7 @@ int cmd_commit_tree(int argc, const char **argv, const char *prefix)
 			if (get_sha1_commit(argv[i], oid.hash))
 				die("Not a valid object name %s", argv[i]);
 			assert_sha1_type(oid.hash, OBJ_COMMIT);
-			new_parent(lookup_commit(oid.hash), &parents);
+			new_parent(lookup_commit(&oid), &parents);
 			continue;
 		}
 
diff --git a/builtin/commit.c b/builtin/commit.c
index 8685c888f..e69f466d5 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1430,7 +1430,7 @@ static void print_summary(const char *prefix, const struct object_id *oid,
 	struct strbuf author_ident = STRBUF_INIT;
 	struct strbuf committer_ident = STRBUF_INIT;
 
-	commit = lookup_commit(oid->hash);
+	commit = lookup_commit(oid);
 	if (!commit)
 		die(_("couldn't look up newly created commit"));
 	if (parse_commit(commit))
@@ -1654,7 +1654,7 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 	if (get_sha1("HEAD", oid.hash))
 		current_head = NULL;
 	else {
-		current_head = lookup_commit_or_die(oid.hash, "HEAD");
+		current_head = lookup_commit_or_die(&oid, "HEAD");
 		if (parse_commit(current_head))
 			die(_("could not parse HEAD commit"));
 	}
diff --git a/builtin/describe.c b/builtin/describe.c
index a5cd8c513..f6032f593 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -281,7 +281,7 @@ static void describe(const char *arg, int last_one)
 
 	if (get_oid(arg, &oid))
 		die(_("Not a valid object name %s"), arg);
-	cmit = lookup_commit_reference(oid.hash);
+	cmit = lookup_commit_reference(&oid);
 	if (!cmit)
 		die(_("%s is not a valid '%s' object"), arg, commit_type);
 
@@ -309,7 +309,7 @@ static void describe(const char *arg, int last_one)
 		struct commit *c;
 		struct commit_name *n = hashmap_iter_first(&names, &iter);
 		for (; n; n = hashmap_iter_next(&iter)) {
-			c = lookup_commit_reference_gently(n->peeled.hash, 1);
+			c = lookup_commit_reference_gently(&n->peeled, 1);
 			if (c)
 				c->util = n;
 		}
diff --git a/builtin/diff-tree.c b/builtin/diff-tree.c
index 326f88b65..e85a449df 100644
--- a/builtin/diff-tree.c
+++ b/builtin/diff-tree.c
@@ -9,7 +9,7 @@ static struct rev_info log_tree_opt;
 
 static int diff_tree_commit_sha1(const struct object_id *oid)
 {
-	struct commit *commit = lookup_commit_reference(oid->hash);
+	struct commit *commit = lookup_commit_reference(oid);
 	if (!commit)
 		return -1;
 	return log_tree_commit(&log_tree_opt, commit);
@@ -23,7 +23,7 @@ static int stdin_diff_commit(struct commit *commit, const char *p)
 
 	/* Graft the fake parents locally to the commit */
 	while (isspace(*p++) && !parse_oid_hex(p, &oid, &p)) {
-		struct commit *parent = lookup_commit(oid.hash);
+		struct commit *parent = lookup_commit(&oid);
 		if (!pptr) {
 			/* Free the real parent list */
 			free_commit_list(commit->parents);
diff --git a/builtin/fast-export.c b/builtin/fast-export.c
index e0220630d..b4521cb62 100644
--- a/builtin/fast-export.c
+++ b/builtin/fast-export.c
@@ -938,7 +938,7 @@ static void import_marks(char *input_file)
 			/* only commits */
 			continue;
 
-		commit = lookup_commit(oid.hash);
+		commit = lookup_commit(&oid);
 		if (!commit)
 			die("not a commit? can't happen: %s", oid_to_hex(&oid));
 
diff --git a/builtin/fetch.c b/builtin/fetch.c
index 5f2c2ab23..d4d573b98 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -636,8 +636,8 @@ static int update_local_ref(struct ref *ref,
 		return r;
 	}
 
-	current = lookup_commit_reference_gently(ref->old_oid.hash, 1);
-	updated = lookup_commit_reference_gently(ref->new_oid.hash, 1);
+	current = lookup_commit_reference_gently(&ref->old_oid, 1);
+	updated = lookup_commit_reference_gently(&ref->new_oid, 1);
 	if (!current || !updated) {
 		const char *msg;
 		const char *what;
@@ -770,7 +770,8 @@ static int store_updated_refs(const char *raw_url, const char *remote_name,
 				continue;
 			}
 
-			commit = lookup_commit_reference_gently(rm->old_oid.hash, 1);
+			commit = lookup_commit_reference_gently(&rm->old_oid,
+								1);
 			if (!commit)
 				rm->fetch_head_status = FETCH_HEAD_NOT_FOR_MERGE;
 
diff --git a/builtin/fmt-merge-msg.c b/builtin/fmt-merge-msg.c
index 6faa3c0d2..91dd753dd 100644
--- a/builtin/fmt-merge-msg.c
+++ b/builtin/fmt-merge-msg.c
@@ -566,7 +566,7 @@ static void find_merge_parents(struct merge_parents *result,
 		commit_list_insert(parent, &parents);
 		add_merge_parent(result, &obj->oid, &parent->object.oid);
 	}
-	head_commit = lookup_commit(head->hash);
+	head_commit = lookup_commit(head);
 	if (head_commit)
 		commit_list_insert(head_commit, &parents);
 	parents = reduce_heads(parents);
@@ -633,7 +633,7 @@ int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
 		struct commit *head;
 		struct rev_info rev;
 
-		head = lookup_commit_or_die(head_oid.hash, "HEAD");
+		head = lookup_commit_or_die(&head_oid, "HEAD");
 		init_revisions(&rev, NULL);
 		rev.commit_format = CMIT_FMT_ONELINE;
 		rev.ignore_merges = 1;
diff --git a/builtin/log.c b/builtin/log.c
index b3b10cc1e..d8b56ea41 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -878,8 +878,8 @@ static void get_patch_ids(struct rev_info *rev, struct patch_ids *ids)
 	o2 = rev->pending.objects[1].item;
 	flags1 = o1->flags;
 	flags2 = o2->flags;
-	c1 = lookup_commit_reference(o1->oid.hash);
-	c2 = lookup_commit_reference(o2->oid.hash);
+	c1 = lookup_commit_reference(&o1->oid);
+	c2 = lookup_commit_reference(&o2->oid);
 
 	if ((flags1 & UNINTERESTING) == (flags2 & UNINTERESTING))
 		die(_("Not a range."));
@@ -1263,7 +1263,7 @@ static struct commit *get_base_commit(const char *base_commit,
 
 			if (get_oid(upstream, &oid))
 				die(_("Failed to resolve '%s' as a valid ref."), upstream);
-			commit = lookup_commit_or_die(oid.hash, "upstream base");
+			commit = lookup_commit_or_die(&oid, "upstream base");
 			base_list = get_merge_bases_many(commit, total, list);
 			/* There should be one and only one merge base. */
 			if (!base_list || base_list->next)
@@ -1819,7 +1819,7 @@ static int add_pending_commit(const char *arg, struct rev_info *revs, int flags)
 {
 	struct object_id oid;
 	if (get_oid(arg, &oid) == 0) {
-		struct commit *commit = lookup_commit_reference(oid.hash);
+		struct commit *commit = lookup_commit_reference(&oid);
 		if (commit) {
 			commit->object.flags |= flags;
 			add_pending_object(revs, &commit->object, arg);
diff --git a/builtin/merge-base.c b/builtin/merge-base.c
index cfe2a796f..5c74ce249 100644
--- a/builtin/merge-base.c
+++ b/builtin/merge-base.c
@@ -41,7 +41,7 @@ static struct commit *get_commit_reference(const char *arg)
 
 	if (get_oid(arg, &revkey))
 		die("Not a valid object name %s", arg);
-	r = lookup_commit_reference(revkey.hash);
+	r = lookup_commit_reference(&revkey);
 	if (!r)
 		die("Not a valid commit name %s", arg);
 
@@ -120,7 +120,7 @@ static void add_one_commit(struct object_id *oid, struct rev_collect *revs)
 	if (is_null_oid(oid))
 		return;
 
-	commit = lookup_commit(oid->hash);
+	commit = lookup_commit(oid);
 	if (!commit ||
 	    (commit->object.flags & TMP_MARK) ||
 	    parse_commit(commit))
@@ -168,7 +168,7 @@ static int handle_fork_point(int argc, const char **argv)
 	if (get_oid(commitname, &oid))
 		die("Not a valid object name: '%s'", commitname);
 
-	derived = lookup_commit_reference(oid.hash);
+	derived = lookup_commit_reference(&oid);
 	memset(&revs, 0, sizeof(revs));
 	revs.initial = 1;
 	for_each_reflog_ent(refname, collect_one_reflog_ent, &revs);
diff --git a/builtin/merge.c b/builtin/merge.c
index 703827f00..f11b5f3de 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -1123,7 +1123,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	if (!branch || is_null_oid(&head_oid))
 		head_commit = NULL;
 	else
-		head_commit = lookup_commit_or_die(head_oid.hash, "HEAD");
+		head_commit = lookup_commit_or_die(&head_oid, "HEAD");
 
 	init_diff_ui_defaults();
 	git_config(git_merge_config, NULL);
diff --git a/builtin/notes.c b/builtin/notes.c
index 7b891471c..f2847c41e 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -706,7 +706,7 @@ static int merge_commit(struct notes_merge_options *o)
 
 	if (get_oid("NOTES_MERGE_PARTIAL", &oid))
 		die(_("failed to read ref NOTES_MERGE_PARTIAL"));
-	else if (!(partial = lookup_commit_reference(oid.hash)))
+	else if (!(partial = lookup_commit_reference(&oid)))
 		die(_("could not find commit from NOTES_MERGE_PARTIAL."));
 	else if (parse_commit(partial))
 		die(_("could not parse commit from NOTES_MERGE_PARTIAL."));
diff --git a/builtin/pull.c b/builtin/pull.c
index dd1a4a94e..2ffb6569a 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -698,10 +698,10 @@ static int get_octopus_merge_base(struct object_id *merge_base,
 {
 	struct commit_list *revs = NULL, *result;
 
-	commit_list_insert(lookup_commit_reference(curr_head->hash), &revs);
-	commit_list_insert(lookup_commit_reference(merge_head->hash), &revs);
+	commit_list_insert(lookup_commit_reference(curr_head), &revs);
+	commit_list_insert(lookup_commit_reference(merge_head), &revs);
 	if (!is_null_oid(fork_point))
-		commit_list_insert(lookup_commit_reference(fork_point->hash), &revs);
+		commit_list_insert(lookup_commit_reference(fork_point), &revs);
 
 	result = reduce_heads(get_octopus_merge_bases(revs));
 	free_commit_list(revs);
@@ -865,9 +865,9 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 		struct commit_list *list = NULL;
 		struct commit *merge_head, *head;
 
-		head = lookup_commit_reference(orig_head.hash);
+		head = lookup_commit_reference(&orig_head);
 		commit_list_insert(head, &list);
-		merge_head = lookup_commit_reference(merge_heads.oid[0].hash);
+		merge_head = lookup_commit_reference(&merge_heads.oid[0]);
 		if (is_descendant_of(merge_head, list)) {
 			/* we can fast-forward this without invoking rebase */
 			opt_ff = "--ff-only";
diff --git a/builtin/reflog.c b/builtin/reflog.c
index d6718d326..4831116ea 100644
--- a/builtin/reflog.c
+++ b/builtin/reflog.c
@@ -192,7 +192,7 @@ static int keep_entry(struct commit **it, struct object_id *oid)
 
 	if (is_null_oid(oid))
 		return 1;
-	commit = lookup_commit_reference_gently(oid->hash, 1);
+	commit = lookup_commit_reference_gently(oid, 1);
 	if (!commit)
 		return 0;
 
@@ -261,7 +261,7 @@ static int unreachable(struct expire_reflog_policy_cb *cb, struct commit *commit
 		if (is_null_oid(oid))
 			return 0;
 
-		commit = lookup_commit_reference_gently(oid->hash, 1);
+		commit = lookup_commit_reference_gently(oid, 1);
 
 		/* Not a commit -- keep it */
 		if (!commit)
@@ -318,7 +318,7 @@ static int push_tip_to_list(const char *refname, const struct object_id *oid,
 	struct commit *tip_commit;
 	if (flags & REF_ISSYMREF)
 		return 0;
-	tip_commit = lookup_commit_reference_gently(oid->hash, 1);
+	tip_commit = lookup_commit_reference_gently(oid, 1);
 	if (!tip_commit)
 		return 0;
 	commit_list_insert(tip_commit, list);
@@ -335,7 +335,7 @@ static void reflog_expiry_prepare(const char *refname,
 		cb->tip_commit = NULL;
 		cb->unreachable_expire_kind = UE_HEAD;
 	} else {
-		cb->tip_commit = lookup_commit_reference_gently(oid->hash, 1);
+		cb->tip_commit = lookup_commit_reference_gently(oid, 1);
 		if (!cb->tip_commit)
 			cb->unreachable_expire_kind = UE_ALWAYS;
 		else
diff --git a/builtin/replace.c b/builtin/replace.c
index ab17668f4..3c44ef750 100644
--- a/builtin/replace.c
+++ b/builtin/replace.c
@@ -328,7 +328,7 @@ static void replace_parents(struct strbuf *buf, int argc, const char **argv)
 		struct object_id oid;
 		if (get_oid(argv[i], &oid) < 0)
 			die(_("Not a valid object name: '%s'"), argv[i]);
-		lookup_commit_or_die(oid.hash, argv[i]);
+		lookup_commit_or_die(&oid, argv[i]);
 		strbuf_addf(&new_parents, "parent %s\n", oid_to_hex(&oid));
 	}
 
@@ -394,7 +394,7 @@ static int create_graft(int argc, const char **argv, int force)
 
 	if (get_oid(old_ref, &old) < 0)
 		die(_("Not a valid object name: '%s'"), old_ref);
-	commit = lookup_commit_or_die(old.hash, old_ref);
+	commit = lookup_commit_or_die(&old, old_ref);
 
 	buffer = get_commit_buffer(commit, &size);
 	strbuf_add(&buf, buffer, size);
diff --git a/builtin/reset.c b/builtin/reset.c
index fc3b906c4..0be52fa36 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -303,7 +303,7 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 		struct commit *commit;
 		if (get_sha1_committish(rev, oid.hash))
 			die(_("Failed to resolve '%s' as a valid revision."), rev);
-		commit = lookup_commit_reference(oid.hash);
+		commit = lookup_commit_reference(&oid);
 		if (!commit)
 			die(_("Could not parse object '%s'."), rev);
 		oidcpy(&oid, &commit->object.oid);
@@ -380,7 +380,7 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 		update_ref_status = reset_refs(rev, &oid);
 
 		if (reset_type == HARD && !update_ref_status && !quiet)
-			print_new_head_line(lookup_commit_reference(oid.hash));
+			print_new_head_line(lookup_commit_reference(&oid));
 	}
 	if (!pathspec.nr)
 		remove_branch_state();
diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index 4af122264..f650188ef 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c
@@ -279,8 +279,8 @@ static int try_difference(const char *arg)
 		if (symmetric) {
 			struct commit_list *exclude;
 			struct commit *a, *b;
-			a = lookup_commit_reference(oid.hash);
-			b = lookup_commit_reference(end.hash);
+			a = lookup_commit_reference(&oid);
+			b = lookup_commit_reference(&end);
 			exclude = get_merge_bases(a, b);
 			while (exclude) {
 				struct commit *commit = pop_commit(&exclude);
@@ -332,7 +332,7 @@ static int try_parent_shorthands(const char *arg)
 		return 0;
 	}
 
-	commit = lookup_commit_reference(oid.hash);
+	commit = lookup_commit_reference(&oid);
 	if (exclude_parent &&
 	    exclude_parent > commit_list_count(commit->parents)) {
 		*dotdot = '^';
diff --git a/builtin/show-branch.c b/builtin/show-branch.c
index 19756595d..71b6f3c17 100644
--- a/builtin/show-branch.c
+++ b/builtin/show-branch.c
@@ -358,7 +358,7 @@ static void sort_ref_range(int bottom, int top)
 static int append_ref(const char *refname, const struct object_id *oid,
 		      int allow_dups)
 {
-	struct commit *commit = lookup_commit_reference_gently(oid->hash, 1);
+	struct commit *commit = lookup_commit_reference_gently(oid, 1);
 	int i;
 
 	if (!commit)
@@ -816,7 +816,7 @@ int cmd_show_branch(int ac, const char **av, const char *prefix)
 			       MAX_REVS), MAX_REVS);
 		if (get_sha1(ref_name[num_rev], revkey.hash))
 			die(_("'%s' is not a valid ref."), ref_name[num_rev]);
-		commit = lookup_commit_reference(revkey.hash);
+		commit = lookup_commit_reference(&revkey);
 		if (!commit)
 			die(_("cannot find commit %s (%s)"),
 			    ref_name[num_rev], oid_to_hex(&revkey));
diff --git a/builtin/tag.c b/builtin/tag.c
index 597c925e3..d0070b37c 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -328,7 +328,7 @@ static void create_reflog_msg(const struct object_id *oid, struct strbuf *sb)
 		}
 		free(buf);
 
-		if ((c = lookup_commit_reference(oid->hash)) != NULL)
+		if ((c = lookup_commit_reference(oid)) != NULL)
 			strbuf_addf(sb, ", %s", show_date(c->date, 0, DATE_MODE(SHORT)));
 		break;
 	case OBJ_TREE:
diff --git a/builtin/verify-commit.c b/builtin/verify-commit.c
index a5db1c427..05b734e6d 100644
--- a/builtin/verify-commit.c
+++ b/builtin/verify-commit.c
@@ -25,7 +25,7 @@ static int run_gpg_verify(const struct object_id *oid, const char *buf, unsigned
 
 	memset(&signature_check, 0, sizeof(signature_check));
 
-	ret = check_commit_signature(lookup_commit(oid->hash), &signature_check);
+	ret = check_commit_signature(lookup_commit(oid), &signature_check);
 	print_signature_buffer(&signature_check, flags);
 
 	signature_check_clear(&signature_check);