Merge branch 'ps/ref-peeled-tags'

Some ref backend storage can hold not just the object name of an
annotated tag, but the object name of the object the tag points at.
The code to handle this information has been streamlined.

* ps/ref-peeled-tags:
  t7004: do not chdir around in the main process
  ref-filter: fix stale parsed objects
  ref-filter: parse objects on demand
  ref-filter: detect broken tags when dereferencing them
  refs: don't store peeled object IDs for invalid tags
  object: add flag to `peel_object()` to verify object type
  refs: drop infrastructure to peel via iterators
  refs: drop `current_ref_iter` hack
  builtin/show-ref: convert to use `reference_get_peeled_oid()`
  ref-filter: propagate peeled object ID
  upload-pack: convert to use `reference_get_peeled_oid()`
  refs: expose peeled object ID via the iterator
  refs: refactor reference status flags
  refs: fully reset `struct ref_iterator::ref` on iteration
  refs: introduce `.ref` field for the base iterator
  refs: introduce wrapper struct for `each_ref_fn`

20 files changed, 156 insertions, 197 deletions

diff --git a/builtin/bisect.c b/builtin/bisect.c
index ccff4e1a1b..4cc118fb57 100644
--- a/builtin/bisect.c
+++ b/builtin/bisect.c
@@ -363,10 +363,7 @@ static int check_and_set_terms(struct bisect_terms *terms, const char *cmd)
 	return 0;
 }
 
-static int inc_nr(const char *refname UNUSED,
-		  const char *referent UNUSED,
-		  const struct object_id *oid UNUSED,
-		  int flag UNUSED, void *cb_data)
+static int inc_nr(const struct reference *ref UNUSED, void *cb_data)
 {
 	unsigned int *nr = (unsigned int *)cb_data;
 	(*nr)++;
@@ -554,12 +551,11 @@ finish:
 	return res;
 }
 
-static int add_bisect_ref(const char *refname, const char *referent UNUSED, const struct object_id *oid,
-			  int flags UNUSED, void *cb)
+static int add_bisect_ref(const struct reference *ref, void *cb)
 {
 	struct add_bisect_ref_data *data = cb;
 
-	add_pending_oid(data->revs, refname, oid, data->object_flags);
+	add_pending_oid(data->revs, ref->name, ref->oid, data->object_flags);
 
 	return 0;
 }
@@ -1170,12 +1166,9 @@ static int bisect_visualize(struct bisect_terms *terms, int argc,
 	return run_command(&cmd);
 }
 
-static int get_first_good(const char *refname UNUSED,
-			  const char *referent UNUSED,
-			  const struct object_id *oid,
-			  int flag UNUSED, void *cb_data)
+static int get_first_good(const struct reference *ref, void *cb_data)
 {
-	oidcpy(cb_data, oid);
+	oidcpy(cb_data, ref->oid);
 	return 1;
 }
 
diff --git a/builtin/checkout.c b/builtin/checkout.c
index f9453473fe..66b69df6e6 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1063,11 +1063,9 @@ static void update_refs_for_switch(const struct checkout_opts *opts,
 		report_tracking(new_branch_info);
 }
 
-static int add_pending_uninteresting_ref(const char *refname, const char *referent UNUSED,
-					 const struct object_id *oid,
-					 int flags UNUSED, void *cb_data)
+static int add_pending_uninteresting_ref(const struct reference *ref, void *cb_data)
 {
-	add_pending_oid(cb_data, refname, oid, UNINTERESTING);
+	add_pending_oid(cb_data, ref->name, ref->oid, UNINTERESTING);
 	return 0;
 }
 
diff --git a/builtin/describe.c b/builtin/describe.c
index ffaf8d9f0a..443546aaac 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -154,20 +154,19 @@ static void add_to_known_names(const char *path,
 	}
 }
 
-static int get_name(const char *path, const char *referent UNUSED, const struct object_id *oid,
-		    int flag UNUSED, void *cb_data UNUSED)
+static int get_name(const struct reference *ref, void *cb_data UNUSED)
 {
 	int is_tag = 0;
 	struct object_id peeled;
 	int is_annotated, prio;
 	const char *path_to_match = NULL;
 
-	if (skip_prefix(path, "refs/tags/", &path_to_match)) {
+	if (skip_prefix(ref->name, "refs/tags/", &path_to_match)) {
 		is_tag = 1;
 	} else if (all) {
 		if ((exclude_patterns.nr || patterns.nr) &&
-		    !skip_prefix(path, "refs/heads/", &path_to_match) &&
-		    !skip_prefix(path, "refs/remotes/", &path_to_match)) {
+		    !skip_prefix(ref->name, "refs/heads/", &path_to_match) &&
+		    !skip_prefix(ref->name, "refs/remotes/", &path_to_match)) {
 			/* Only accept reference of known type if there are match/exclude patterns */
 			return 0;
 		}
@@ -209,10 +208,10 @@ static int get_name(const char *path, const char *referent UNUSED, const struct
 	}
 
 	/* Is it annotated? */
-	if (!peel_iterated_oid(the_repository, oid, &peeled)) {
-		is_annotated = !oideq(oid, &peeled);
+	if (!reference_get_peeled_oid(the_repository, ref, &peeled)) {
+		is_annotated = !oideq(ref->oid, &peeled);
 	} else {
-		oidcpy(&peeled, oid);
+		oidcpy(&peeled, ref->oid);
 		is_annotated = 0;
 	}
 
@@ -229,7 +228,8 @@ static int get_name(const char *path, const char *referent UNUSED, const struct
 	else
 		prio = 0;
 
-	add_to_known_names(all ? path + 5 : path + 10, &peeled, prio, oid);
+	add_to_known_names(all ? ref->name + 5 : ref->name + 10,
+			   &peeled, prio, ref->oid);
 	return 0;
 }
 
diff --git a/builtin/fetch.c b/builtin/fetch.c
index c7ff3480fb..7052e6ff21 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -289,13 +289,11 @@ static struct refname_hash_entry *refname_hash_add(struct hashmap *map,
 	return ent;
 }
 
-static int add_one_refname(const char *refname, const char *referent UNUSED,
-			   const struct object_id *oid,
-			   int flag UNUSED, void *cbdata)
+static int add_one_refname(const struct reference *ref, void *cbdata)
 {
 	struct hashmap *refname_map = cbdata;
 
-	(void) refname_hash_add(refname_map, refname, oid);
+	(void) refname_hash_add(refname_map, ref->name, ref->oid);
 	return 0;
 }
 
@@ -1416,14 +1414,11 @@ static void set_option(struct transport *transport, const char *name, const char
 }
 
 
-static int add_oid(const char *refname UNUSED,
-		   const char *referent UNUSED,
-		   const struct object_id *oid,
-		   int flags UNUSED, void *cb_data)
+static int add_oid(const struct reference *ref, void *cb_data)
 {
 	struct oid_array *oids = cb_data;
 
-	oid_array_append(oids, oid);
+	oid_array_append(oids, ref->oid);
 	return 0;
 }
 
diff --git a/builtin/fsck.c b/builtin/fsck.c
index b1a650c673..c489582faa 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -530,14 +530,13 @@ static int fsck_handle_reflog(const char *logname, void *cb_data)
 	return 0;
 }
 
-static int fsck_handle_ref(const char *refname, const char *referent UNUSED, const struct object_id *oid,
-			   int flag UNUSED, void *cb_data UNUSED)
+static int fsck_handle_ref(const struct reference *ref, void *cb_data UNUSED)
 {
 	struct object *obj;
 
-	obj = parse_object(the_repository, oid);
+	obj = parse_object(the_repository, ref->oid);
 	if (!obj) {
-		if (is_promisor_object(the_repository, oid)) {
+		if (is_promisor_object(the_repository, ref->oid)) {
 			/*
 			 * Increment default_refs anyway, because this is a
 			 * valid ref.
@@ -546,19 +545,19 @@ static int fsck_handle_ref(const char *refname, const char *referent UNUSED, con
 			 return 0;
 		}
 		error(_("%s: invalid sha1 pointer %s"),
-		      refname, oid_to_hex(oid));
+		      ref->name, oid_to_hex(ref->oid));
 		errors_found |= ERROR_REACHABLE;
 		/* We'll continue with the rest despite the error.. */
 		return 0;
 	}
-	if (obj->type != OBJ_COMMIT && is_branch(refname)) {
-		error(_("%s: not a commit"), refname);
+	if (obj->type != OBJ_COMMIT && is_branch(ref->name)) {
+		error(_("%s: not a commit"), ref->name);
 		errors_found |= ERROR_REFS;
 	}
 	default_refs++;
 	obj->flags |= USED;
 	fsck_put_object_name(&fsck_walk_options,
-			     oid, "%s", refname);
+			     ref->oid, "%s", ref->name);
 	mark_object_reachable(obj);
 
 	return 0;
@@ -580,13 +579,19 @@ static void get_default_heads(void)
 	worktrees = get_worktrees();
 	for (p = worktrees; *p; p++) {
 		struct worktree *wt = *p;
-		struct strbuf ref = STRBUF_INIT;
+		struct strbuf refname = STRBUF_INIT;
 
-		strbuf_worktree_ref(wt, &ref, "HEAD");
-		fsck_head_link(ref.buf, &head_points_at, &head_oid);
-		if (head_points_at && !is_null_oid(&head_oid))
-			fsck_handle_ref(ref.buf, NULL, &head_oid, 0, NULL);
-		strbuf_release(&ref);
+		strbuf_worktree_ref(wt, &refname, "HEAD");
+		fsck_head_link(refname.buf, &head_points_at, &head_oid);
+		if (head_points_at && !is_null_oid(&head_oid)) {
+			struct reference ref = {
+				.name = refname.buf,
+				.oid = &head_oid,
+			};
+
+			fsck_handle_ref(&ref, NULL);
+		}
+		strbuf_release(&refname);
 
 		if (include_reflogs)
 			refs_for_each_reflog(get_worktree_ref_store(wt),
diff --git a/builtin/gc.c b/builtin/gc.c
index d212cbb9b8..aad1496f07 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -1103,24 +1103,21 @@ struct cg_auto_data {
 	int limit;
 };
 
-static int dfs_on_ref(const char *refname UNUSED,
-		      const char *referent UNUSED,
-		      const struct object_id *oid,
-		      int flags UNUSED,
-		      void *cb_data)
+static int dfs_on_ref(const struct reference *ref, void *cb_data)
 {
 	struct cg_auto_data *data = (struct cg_auto_data *)cb_data;
 	int result = 0;
+	const struct object_id *maybe_peeled = ref->oid;
 	struct object_id peeled;
 	struct commit_list *stack = NULL;
 	struct commit *commit;
 
-	if (!peel_iterated_oid(the_repository, oid, &peeled))
-		oid = &peeled;
-	if (odb_read_object_info(the_repository->objects, oid, NULL) != OBJ_COMMIT)
+	if (!reference_get_peeled_oid(the_repository, ref, &peeled))
+		maybe_peeled = &peeled;
+	if (odb_read_object_info(the_repository->objects, maybe_peeled, NULL) != OBJ_COMMIT)
 		return 0;
 
-	commit = lookup_commit(the_repository, oid);
+	commit = lookup_commit(the_repository, maybe_peeled);
 	if (!commit)
 		return 0;
 	if (repo_parse_commit(the_repository, commit) ||
diff --git a/builtin/ls-remote.c b/builtin/ls-remote.c
index df09000b30..fe77829557 100644
--- a/builtin/ls-remote.c
+++ b/builtin/ls-remote.c
@@ -156,7 +156,7 @@ int cmd_ls_remote(int argc,
 			continue;
 		if (!tail_match(&pattern, ref->name))
 			continue;
-		item = ref_array_push(&ref_array, ref->name, &ref->old_oid);
+		item = ref_array_push(&ref_array, ref->name, &ref->old_oid, NULL);
 		item->symref = xstrdup_or_null(ref->symref);
 	}
 
diff --git a/builtin/name-rev.c b/builtin/name-rev.c
index 74512e54a3..615f7d1aae 100644
--- a/builtin/name-rev.c
+++ b/builtin/name-rev.c
@@ -339,10 +339,9 @@ static int cmp_by_tag_and_age(const void *a_, const void *b_)
 	return a->taggerdate != b->taggerdate;
 }
 
-static int name_ref(const char *path, const char *referent UNUSED, const struct object_id *oid,
-		    int flags UNUSED, void *cb_data)
+static int name_ref(const struct reference *ref, void *cb_data)
 {
-	struct object *o = parse_object(the_repository, oid);
+	struct object *o = parse_object(the_repository, ref->oid);
 	struct name_ref_data *data = cb_data;
 	int can_abbreviate_output = data->tags_only && data->name_only;
 	int deref = 0;
@@ -350,14 +349,14 @@ static int name_ref(const char *path, const char *referent UNUSED, const struct
 	struct commit *commit = NULL;
 	timestamp_t taggerdate = TIME_MAX;
 
-	if (data->tags_only && !starts_with(path, "refs/tags/"))
+	if (data->tags_only && !starts_with(ref->name, "refs/tags/"))
 		return 0;
 
 	if (data->exclude_filters.nr) {
 		struct string_list_item *item;
 
 		for_each_string_list_item(item, &data->exclude_filters) {
-			if (subpath_matches(path, item->string) >= 0)
+			if (subpath_matches(ref->name, item->string) >= 0)
 				return 0;
 		}
 	}
@@ -378,7 +377,7 @@ static int name_ref(const char *path, const char *referent UNUSED, const struct
 			 * shouldn't stop when seeing 'refs/tags/v1.4' matches
 			 * 'refs/tags/v*'.  We should show it as 'v1.4'.
 			 */
-			switch (subpath_matches(path, item->string)) {
+			switch (subpath_matches(ref->name, item->string)) {
 			case -1: /* did not match */
 				break;
 			case 0: /* matched fully */
@@ -406,13 +405,13 @@ static int name_ref(const char *path, const char *referent UNUSED, const struct
 	}
 	if (o && o->type == OBJ_COMMIT) {
 		commit = (struct commit *)o;
-		from_tag = starts_with(path, "refs/tags/");
+		from_tag = starts_with(ref->name, "refs/tags/");
 		if (taggerdate == TIME_MAX)
 			taggerdate = commit->date;
 	}
 
-	add_to_tip_table(oid, path, can_abbreviate_output, commit, taggerdate,
-			 from_tag, deref);
+	add_to_tip_table(ref->oid, ref->name, can_abbreviate_output,
+			 commit, taggerdate, from_tag, deref);
 	return 0;
 }
 
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 0e4e9f8068..4486b55e6d 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -831,15 +831,14 @@ static enum write_one_status write_one(struct hashfile *f,
 	return WRITE_ONE_WRITTEN;
 }
 
-static int mark_tagged(const char *path UNUSED, const char *referent UNUSED, const struct object_id *oid,
-		       int flag UNUSED, void *cb_data UNUSED)
+static int mark_tagged(const struct reference *ref, void *cb_data UNUSED)
 {
 	struct object_id peeled;
-	struct object_entry *entry = packlist_find(&to_pack, oid);
+	struct object_entry *entry = packlist_find(&to_pack, ref->oid);
 
 	if (entry)
 		entry->tagged = 1;
-	if (!peel_iterated_oid(the_repository, oid, &peeled)) {
+	if (!reference_get_peeled_oid(the_repository, ref, &peeled)) {
 		entry = packlist_find(&to_pack, &peeled);
 		if (entry)
 			entry->tagged = 1;
@@ -3305,13 +3304,13 @@ static void add_tag_chain(const struct object_id *oid)
 	}
 }
 
-static int add_ref_tag(const char *tag UNUSED, const char *referent UNUSED, const struct object_id *oid,
-		       int flag UNUSED, void *cb_data UNUSED)
+static int add_ref_tag(const struct reference *ref, void *cb_data UNUSED)
 {
 	struct object_id peeled;
 
-	if (!peel_iterated_oid(the_repository, oid, &peeled) && obj_is_packed(&peeled))
-		add_tag_chain(oid);
+	if (!reference_get_peeled_oid(the_repository, ref, &peeled) &&
+	    obj_is_packed(&peeled))
+		add_tag_chain(ref->oid);
 	return 0;
 }
 
@@ -4527,19 +4526,16 @@ static void record_recent_commit(struct commit *commit, void *data UNUSED)
 	oid_array_append(&recent_objects, &commit->object.oid);
 }
 
-static int mark_bitmap_preferred_tip(const char *refname,
-				     const char *referent UNUSED,
-				     const struct object_id *oid,
-				     int flags UNUSED,
-				     void *data UNUSED)
+static int mark_bitmap_preferred_tip(const struct reference *ref, void *data UNUSED)
 {
+	const struct object_id *maybe_peeled = ref->oid;
 	struct object_id peeled;
 	struct object *object;
 
-	if (!peel_iterated_oid(the_repository, oid, &peeled))
-		oid = &peeled;
+	if (!reference_get_peeled_oid(the_repository, ref, &peeled))
+		maybe_peeled = &peeled;
 
-	object = parse_object_or_die(the_repository, oid, refname);
+	object = parse_object_or_die(the_repository, maybe_peeled, ref->name);
 	if (object->type == OBJ_COMMIT)
 		object->flags |= NEEDS_BITMAP;
 
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index c9288a9c7e..e8ee0e7321 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -305,13 +305,12 @@ static void show_ref(const char *path, const struct object_id *oid)
 	}
 }
 
-static int show_ref_cb(const char *path_full, const char *referent UNUSED, const struct object_id *oid,
-		       int flag UNUSED, void *data)
+static int show_ref_cb(const struct reference *ref, void *data)
 {
 	struct oidset *seen = data;
-	const char *path = strip_namespace(path_full);
+	const char *path = strip_namespace(ref->name);
 
-	if (ref_is_hidden(path, path_full, &hidden_refs))
+	if (ref_is_hidden(path, ref->name, &hidden_refs))
 		return 0;
 
 	/*
@@ -320,13 +319,13 @@ static int show_ref_cb(const char *path_full, const char *referent UNUSED, const
 	 * transfer but will otherwise ignore them.
 	 */
 	if (!path) {
-		if (oidset_insert(seen, oid))
+		if (oidset_insert(seen, ref->oid))
 			return 0;
 		path = ".have";
 	} else {
-		oidset_insert(seen, oid);
+		oidset_insert(seen, ref->oid);
 	}
-	show_ref(path, oid);
+	show_ref(path, ref->oid);
 	return 0;
 }
 
diff --git a/builtin/remote.c b/builtin/remote.c
index 8a7ed4299a..7ffc14ba15 100644
--- a/builtin/remote.c
+++ b/builtin/remote.c
@@ -570,17 +570,14 @@ struct branches_for_remote {
 	struct known_remotes *keep;
 };
 
-static int add_branch_for_removal(const char *refname,
-				  const char *referent UNUSED,
-				  const struct object_id *oid UNUSED,
-				  int flags UNUSED, void *cb_data)
+static int add_branch_for_removal(const struct reference *ref, void *cb_data)
 {
 	struct branches_for_remote *branches = cb_data;
 	struct refspec_item refspec;
 	struct known_remote *kr;
 
 	memset(&refspec, 0, sizeof(refspec));
-	refspec.dst = (char *)refname;
+	refspec.dst = (char *)ref->name;
 	if (remote_find_tracking(branches->remote, &refspec))
 		return 0;
 	free(refspec.src);
@@ -588,7 +585,7 @@ static int add_branch_for_removal(const char *refname,
 	/* don't delete a branch if another remote also uses it */
 	for (kr = branches->keep->list; kr; kr = kr->next) {
 		memset(&refspec, 0, sizeof(refspec));
-		refspec.dst = (char *)refname;
+		refspec.dst = (char *)ref->name;
 		if (!remote_find_tracking(kr->remote, &refspec)) {
 			free(refspec.src);
 			return 0;
@@ -596,16 +593,16 @@ static int add_branch_for_removal(const char *refname,
 	}
 
 	/* don't delete non-remote-tracking refs */
-	if (!starts_with(refname, "refs/remotes/")) {
+	if (!starts_with(ref->name, "refs/remotes/")) {
 		/* advise user how to delete local branches */
-		if (starts_with(refname, "refs/heads/"))
+		if (starts_with(ref->name, "refs/heads/"))
 			string_list_append(branches->skipped,
-					   abbrev_branch(refname));
+					   abbrev_branch(ref->name));
 		/* silently skip over other non-remote refs */
 		return 0;
 	}
 
-	string_list_append(branches->branches, refname);
+	string_list_append(branches->branches, ref->name);
 
 	return 0;
 }
@@ -713,18 +710,18 @@ out:
 	return error;
 }
 
-static int rename_one_ref(const char *old_refname, const char *referent,
-			  const struct object_id *oid,
-			  int flags, void *cb_data)
+static int rename_one_ref(const struct reference *ref, void *cb_data)
 {
 	struct strbuf new_referent = STRBUF_INIT;
 	struct strbuf new_refname = STRBUF_INIT;
 	struct rename_info *rename = cb_data;
+	const struct object_id *oid = ref->oid;
+	const char *referent = ref->target;
 	int error;
 
-	compute_renamed_ref(rename, old_refname, &new_refname);
+	compute_renamed_ref(rename, ref->name, &new_refname);
 
-	if (flags & REF_ISSYMREF) {
+	if (ref->flags & REF_ISSYMREF) {
 		/*
 		 * Stupidly enough `referent` is not pointing to the immediate
 		 * target of a symref, but it's the recursively resolved value.
@@ -732,25 +729,25 @@ static int rename_one_ref(const char *old_refname, const char *referent,
 		 * unborn symrefs don't have any value for the `referent` at all.
 		 */
 		referent = refs_resolve_ref_unsafe(get_main_ref_store(the_repository),
-						   old_refname, RESOLVE_REF_NO_RECURSE,
+						   ref->name, RESOLVE_REF_NO_RECURSE,
 						   NULL, NULL);
 		compute_renamed_ref(rename, referent, &new_referent);
 		oid = NULL;
 	}
 
-	error = ref_transaction_delete(rename->transaction, old_refname,
+	error = ref_transaction_delete(rename->transaction, ref->name,
 				       oid, referent, REF_NO_DEREF, NULL, rename->err);
 	if (error < 0)
 		goto out;
 
 	error = ref_transaction_update(rename->transaction, new_refname.buf, oid, null_oid(the_hash_algo),
-				       (flags & REF_ISSYMREF) ? new_referent.buf : NULL, NULL,
+				       (ref->flags & REF_ISSYMREF) ? new_referent.buf : NULL, NULL,
 				       REF_SKIP_CREATE_REFLOG | REF_NO_DEREF | REF_SKIP_OID_VERIFICATION,
 				       NULL, rename->err);
 	if (error < 0)
 		goto out;
 
-	error = rename_one_reflog(old_refname, oid, rename);
+	error = rename_one_reflog(ref->name, oid, rename);
 	if (error < 0)
 		goto out;
 
@@ -1125,19 +1122,16 @@ static void free_remote_ref_states(struct ref_states *states)
 	string_list_clear_func(&states->push, clear_push_info);
 }
 
-static int append_ref_to_tracked_list(const char *refname,
-				      const char *referent UNUSED,
-				      const struct object_id *oid UNUSED,
-				      int flags, void *cb_data)
+static int append_ref_to_tracked_list(const struct reference *ref, void *cb_data)
 {
 	struct ref_states *states = cb_data;
 	struct refspec_item refspec;
 
-	if (flags & REF_ISSYMREF)
+	if (ref->flags & REF_ISSYMREF)
 		return 0;
 
 	memset(&refspec, 0, sizeof(refspec));
-	refspec.dst = (char *)refname;
+	refspec.dst = (char *)ref->name;
 	if (!remote_find_tracking(states->remote, &refspec)) {
 		string_list_append(&states->tracked, abbrev_branch(refspec.src));
 		free(refspec.src);
diff --git a/builtin/replace.c b/builtin/replace.c
index 900b560a77..4c62c5ab58 100644
--- a/builtin/replace.c
+++ b/builtin/replace.c
@@ -47,30 +47,27 @@ struct show_data {
 	enum replace_format format;
 };
 
-static int show_reference(const char *refname,
-			  const char *referent UNUSED,
-			  const struct object_id *oid,
-			  int flag UNUSED, void *cb_data)
+static int show_reference(const struct reference *ref, void *cb_data)
 {
 	struct show_data *data = cb_data;
 
-	if (!wildmatch(data->pattern, refname, 0)) {
+	if (!wildmatch(data->pattern, ref->name, 0)) {
 		if (data->format == REPLACE_FORMAT_SHORT)
-			printf("%s\n", refname);
+			printf("%s\n", ref->name);
 		else if (data->format == REPLACE_FORMAT_MEDIUM)
-			printf("%s -> %s\n", refname, oid_to_hex(oid));
+			printf("%s -> %s\n", ref->name, oid_to_hex(ref->oid));
 		else { /* data->format == REPLACE_FORMAT_LONG */
 			struct object_id object;
 			enum object_type obj_type, repl_type;
 
-			if (repo_get_oid(data->repo, refname, &object))
-				return error(_("failed to resolve '%s' as a valid ref"), refname);
+			if (repo_get_oid(data->repo, ref->name, &object))
+				return error(_("failed to resolve '%s' as a valid ref"), ref->name);
 
 			obj_type = odb_read_object_info(data->repo->objects, &object, NULL);
-			repl_type = odb_read_object_info(data->repo->objects, oid, NULL);
+			repl_type = odb_read_object_info(data->repo->objects, ref->oid, NULL);
 
-			printf("%s (%s) -> %s (%s)\n", refname, type_name(obj_type),
-			       oid_to_hex(oid), type_name(repl_type));
+			printf("%s (%s) -> %s (%s)\n", ref->name, type_name(obj_type),
+			       oid_to_hex(ref->oid), type_name(repl_type));
 		}
 	}
 
diff --git a/builtin/repo.c b/builtin/repo.c
index 9d4749f79b..f26640bd6e 100644
--- a/builtin/repo.c
+++ b/builtin/repo.c
@@ -366,16 +366,13 @@ struct count_references_data {
 	struct progress *progress;
 };
 
-static int count_references(const char *refname,
-			    const char *referent UNUSED,
-			    const struct object_id *oid,
-			    int flags UNUSED, void *cb_data)
+static int count_references(const struct reference *ref, void *cb_data)
 {
 	struct count_references_data *data = cb_data;
 	struct ref_stats *stats = data->stats;
 	size_t ref_count;
 
-	switch (ref_kind_from_refname(refname)) {
+	switch (ref_kind_from_refname(ref->name)) {
 	case FILTER_REFS_BRANCHES:
 		stats->branches++;
 		break;
@@ -396,7 +393,7 @@ static int count_references(const char *refname,
 	 * While iterating through references for counting, also add OIDs in
 	 * preparation for the path walk.
 	 */
-	add_pending_oid(data->revs, NULL, oid, 0);
+	add_pending_oid(data->revs, NULL, ref->oid, 0);
 
 	ref_count = get_total_reference_count(stats);
 	display_progress(data->progress, ref_count);
diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index 7b3711cf34..9032cc6327 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c
@@ -217,19 +217,17 @@ static int show_default(void)
 	return 0;
 }
 
-static int show_reference(const char *refname, const char *referent UNUSED, const struct object_id *oid,
-			  int flag UNUSED, void *cb_data UNUSED)
+static int show_reference(const struct reference *ref, void *cb_data UNUSED)
 {
-	if (ref_excluded(&ref_excludes, refname))
+	if (ref_excluded(&ref_excludes, ref->name))
 		return 0;
-	show_rev(NORMAL, oid, refname);
+	show_rev(NORMAL, ref->oid, ref->name);
 	return 0;
 }
 
-static int anti_reference(const char *refname, const char *referent UNUSED, const struct object_id *oid,
-			  int flag UNUSED, void *cb_data UNUSED)
+static int anti_reference(const struct reference *ref, void *cb_data UNUSED)
 {
-	show_rev(REVERSED, oid, refname);
+	show_rev(REVERSED, ref->oid, ref->name);
 	return 0;
 }
 
diff --git a/builtin/show-branch.c b/builtin/show-branch.c
index 441babf2e3..10475a6b5e 100644
--- a/builtin/show-branch.c
+++ b/builtin/show-branch.c
@@ -413,34 +413,32 @@ static int append_ref(const char *refname, const struct object_id *oid,
 	return 0;
 }
 
-static int append_head_ref(const char *refname, const char *referent UNUSED, const struct object_id *oid,
-			   int flag UNUSED, void *cb_data UNUSED)
+static int append_head_ref(const struct reference *ref, void *cb_data UNUSED)
 {
 	struct object_id tmp;
 	int ofs = 11;
-	if (!starts_with(refname, "refs/heads/"))
+	if (!starts_with(ref->name, "refs/heads/"))
 		return 0;
 	/* If both heads/foo and tags/foo exists, get_sha1 would
 	 * get confused.
 	 */
-	if (repo_get_oid(the_repository, refname + ofs, &tmp) || !oideq(&tmp, oid))
+	if (repo_get_oid(the_repository, ref->name + ofs, &tmp) || !oideq(&tmp, ref->oid))
 		ofs = 5;
-	return append_ref(refname + ofs, oid, 0);
+	return append_ref(ref->name + ofs, ref->oid, 0);
 }
 
-static int append_remote_ref(const char *refname, const char *referent UNUSED, const struct object_id *oid,
-			     int flag UNUSED, void *cb_data UNUSED)
+static int append_remote_ref(const struct reference *ref, void *cb_data UNUSED)
 {
 	struct object_id tmp;
 	int ofs = 13;
-	if (!starts_with(refname, "refs/remotes/"))
+	if (!starts_with(ref->name, "refs/remotes/"))
 		return 0;
 	/* If both heads/foo and tags/foo exists, get_sha1 would
 	 * get confused.
 	 */
-	if (repo_get_oid(the_repository, refname + ofs, &tmp) || !oideq(&tmp, oid))
+	if (repo_get_oid(the_repository, ref->name + ofs, &tmp) || !oideq(&tmp, ref->oid))
 		ofs = 5;
-	return append_ref(refname + ofs, oid, 0);
+	return append_ref(ref->name + ofs, ref->oid, 0);
 }
 
 static int append_tag_ref(const char *refname, const struct object_id *oid,
@@ -454,27 +452,26 @@ static int append_tag_ref(const char *refname, const struct object_id *oid,
 static const char *match_ref_pattern = NULL;
 static int match_ref_slash = 0;
 
-static int append_matching_ref(const char *refname, const char *referent UNUSED, const struct object_id *oid,
-			       int flag, void *cb_data)
+static int append_matching_ref(const struct reference *ref, void *cb_data)
 {
 	/* we want to allow pattern hold/<asterisk> to show all
 	 * branches under refs/heads/hold/, and v0.99.9? to show
 	 * refs/tags/v0.99.9a and friends.
 	 */
 	const char *tail;
-	int slash = count_slashes(refname);
-	for (tail = refname; *tail && match_ref_slash < slash; )
+	int slash = count_slashes(ref->name);
+	for (tail = ref->name; *tail && match_ref_slash < slash; )
 		if (*tail++ == '/')
 			slash--;
 	if (!*tail)
 		return 0;
 	if (wildmatch(match_ref_pattern, tail, 0))
 		return 0;
-	if (starts_with(refname, "refs/heads/"))
-		return append_head_ref(refname, NULL, oid, flag, cb_data);
-	if (starts_with(refname, "refs/tags/"))
-		return append_tag_ref(refname, oid, flag, cb_data);
-	return append_ref(refname, oid, 0);
+	if (starts_with(ref->name, "refs/heads/"))
+		return append_head_ref(ref, cb_data);
+	if (starts_with(ref->name, "refs/tags/"))
+		return append_tag_ref(ref->name, ref->oid, ref->flags, cb_data);
+	return append_ref(ref->name, ref->oid, 0);
 }
 
 static void snarf_refs(int head, int remotes)
diff --git a/builtin/show-ref.c b/builtin/show-ref.c
index 0b6f9edf86..4d4984e4e0 100644
--- a/builtin/show-ref.c
+++ b/builtin/show-ref.c
@@ -31,31 +31,31 @@ struct show_one_options {
 };
 
 static void show_one(const struct show_one_options *opts,
-		     const char *refname, const struct object_id *oid)
+		     const struct reference *ref)
 {
 	const char *hex;
 	struct object_id peeled;
 
-	if (!odb_has_object(the_repository->objects, oid,
+	if (!odb_has_object(the_repository->objects, ref->oid,
 			    HAS_OBJECT_RECHECK_PACKED | HAS_OBJECT_FETCH_PROMISOR))
-		die("git show-ref: bad ref %s (%s)", refname,
-		    oid_to_hex(oid));
+		die("git show-ref: bad ref %s (%s)", ref->name,
+		    oid_to_hex(ref->oid));
 
 	if (opts->quiet)
 		return;
 
-	hex = repo_find_unique_abbrev(the_repository, oid, opts->abbrev);
+	hex = repo_find_unique_abbrev(the_repository, ref->oid, opts->abbrev);
 	if (opts->hash_only)
 		printf("%s\n", hex);
 	else
-		printf("%s %s\n", hex, refname);
+		printf("%s %s\n", hex, ref->name);
 
 	if (!opts->deref_tags)
 		return;
 
-	if (!peel_iterated_oid(the_repository, oid, &peeled)) {
+	if (!reference_get_peeled_oid(the_repository, ref, &peeled)) {
 		hex = repo_find_unique_abbrev(the_repository, &peeled, opts->abbrev);
-		printf("%s %s^{}\n", hex, refname);
+		printf("%s %s^{}\n", hex, ref->name);
 	}
 }
 
@@ -66,26 +66,25 @@ struct show_ref_data {
 	int show_head;
 };
 
-static int show_ref(const char *refname, const char *referent UNUSED, const struct object_id *oid,
-		    int flag UNUSED, void *cbdata)
+static int show_ref(const struct reference *ref, void *cbdata)
 {
 	struct show_ref_data *data = cbdata;
 
-	if (data->show_head && !strcmp(refname, "HEAD"))
+	if (data->show_head && !strcmp(ref->name, "HEAD"))
 		goto match;
 
 	if (data->patterns) {
-		int reflen = strlen(refname);
+		int reflen = strlen(ref->name);
 		const char **p = data->patterns, *m;
 		while ((m = *p++) != NULL) {
 			int len = strlen(m);
 			if (len > reflen)
 				continue;
-			if (memcmp(m, refname + reflen - len, len))
+			if (memcmp(m, ref->name + reflen - len, len))
 				continue;
 			if (len == reflen)
 				goto match;
-			if (refname[reflen - len - 1] == '/')
+			if (ref->name[reflen - len - 1] == '/')
 				goto match;
 		}
 		return 0;
@@ -94,18 +93,15 @@ static int show_ref(const char *refname, const char *referent UNUSED, const stru
 match:
 	data->found_match++;
 
-	show_one(data->show_one_opts, refname, oid);
+	show_one(data->show_one_opts, ref);
 
 	return 0;
 }
 
-static int add_existing(const char *refname,
-			const char *referent UNUSED,
-			const struct object_id *oid UNUSED,
-			int flag UNUSED, void *cbdata)
+static int add_existing(const struct reference *ref, void *cbdata)
 {
 	struct string_list *list = (struct string_list *)cbdata;
-	string_list_insert(list, refname);
+	string_list_insert(list, ref->name);
 	return 0;
 }
 
@@ -179,12 +175,18 @@ static int cmd_show_ref__verify(const struct show_one_options *show_one_opts,
 
 		if ((starts_with(*refs, "refs/") || refname_is_safe(*refs)) &&
 		    !refs_read_ref(get_main_ref_store(the_repository), *refs, &oid)) {
-			show_one(show_one_opts, *refs, &oid);
-		}
-		else if (!show_one_opts->quiet)
+			struct reference ref = {
+				.name = *refs,
+				.oid = &oid,
+			};
+
+			show_one(show_one_opts, &ref);
+		} else if (!show_one_opts->quiet) {
 			die("'%s' - not a valid ref", *refs);
-		else
+		} else {
 			return 1;
+		}
+
 		refs++;
 	}
 
diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index fcd73abe53..35f6cf735e 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -593,16 +593,12 @@ static void print_status(unsigned int flags, char state, const char *path,
 	printf("\n");
 }
 
-static int handle_submodule_head_ref(const char *refname UNUSED,
-				     const char *referent UNUSED,
-				     const struct object_id *oid,
-				     int flags UNUSED,
-				     void *cb_data)
+static int handle_submodule_head_ref(const struct reference *ref, void *cb_data)
 {
 	struct object_id *output = cb_data;
 
-	if (oid)
-		oidcpy(output, oid);
+	if (ref->oid)
+		oidcpy(output, ref->oid);
 
 	return 0;
 }
diff --git a/builtin/tag.c b/builtin/tag.c
index f0665af3ac..01eba90c5c 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -153,7 +153,7 @@ static int verify_tag(const char *name, const char *ref UNUSED,
 		return -1;
 
 	if (format->format)
-		pretty_print_ref(name, oid, format);
+		pretty_print_ref(name, oid, NULL, format);
 
 	return 0;
 }
diff --git a/builtin/verify-tag.c b/builtin/verify-tag.c
index cd6bc11095..558121eaa1 100644
--- a/builtin/verify-tag.c
+++ b/builtin/verify-tag.c
@@ -67,7 +67,7 @@ int cmd_verify_tag(int argc,
 		}
 
 		if (format.format)
-			pretty_print_ref(name, &oid, &format);
+			pretty_print_ref(name, &oid, NULL, &format);
 	}
 	return had_error;
 }
diff --git a/builtin/worktree.c b/builtin/worktree.c
index 812774a5ca..b7f323b5e4 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -635,11 +635,7 @@ static void print_preparing_worktree_line(int detach,
  *
  * Returns 0 on failure and non-zero on success.
  */
-static int first_valid_ref(const char *refname UNUSED,
-			   const char *referent UNUSED,
-			   const struct object_id *oid UNUSED,
-			   int flags UNUSED,
-			   void *cb_data UNUSED)
+static int first_valid_ref(const struct reference *ref UNUSED, void *cb_data UNUSED)
 {
 	return 1;
 }