tag: add repository argument to lookup_tag

Add a repository argument to allow the callers of lookup_tag
to be more specific about which repository to act on. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/describe.c b/builtin/describe.c
index c8ff647..41606c8 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -93,13 +93,13 @@ static int replace_name(struct commit_name *e,
 		struct tag *t;
 
 		if (!e->tag) {
-			t = lookup_tag(&e->oid);
+			t = lookup_tag(the_repository, &e->oid);
 			if (!t || parse_tag(t))
 				return 1;
 			e->tag = t;
 		}
 
-		t = lookup_tag(oid);
+		t = lookup_tag(the_repository, oid);
 		if (!t || parse_tag(t))
 			return 0;
 		*tag = t;
@@ -267,7 +267,7 @@ static unsigned long finish_depth_computation(
 static void append_name(struct commit_name *n, struct strbuf *dst)
 {
 	if (n->prio == 2 && !n->tag) {
-		n->tag = lookup_tag(&n->oid);
+		n->tag = lookup_tag(the_repository, &n->oid);
 		if (!n->tag || parse_tag(n->tag))
 			die(_("annotated tag %s not available"), n->path);
 	}
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 69d3d7b..6565c80 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -2474,7 +2474,7 @@ static void add_tag_chain(const struct object_id *oid)
 	if (packlist_find(&to_pack, oid->hash, NULL))
 		return;
 
-	tag = lookup_tag(oid);
+	tag = lookup_tag(the_repository, oid);
 	while (1) {
 		if (!tag || parse_tag(tag) || !tag->tagged)
 			die("unable to pack objects reachable from tag %s",
diff --git a/builtin/replace.c b/builtin/replace.c
index 0232f98..0351b7c 100644
--- a/builtin/replace.c
+++ b/builtin/replace.c
@@ -402,7 +402,7 @@ static int check_one_mergetag(struct commit *commit,
 	int i;
 
 	hash_object_file(extra->value, extra->len, type_name(OBJ_TAG), &tag_oid);
-	tag = lookup_tag(&tag_oid);
+	tag = lookup_tag(the_repository, &tag_oid);
 	if (!tag)
 		return error(_("bad mergetag in commit '%s'"), ref);
 	if (parse_tag_buffer(tag, extra->value, extra->len))