alloc: add repository argument to alloc_tag_node

This is a small mechanical change; it doesn't change the
implementation to handle repositories other than the_repository yet.
Use a macro to catch callers passing a repository other than
the_repository at compile time.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

alloc.c

@@ -65,7 +65,7 @@ void *alloc_tree_node_the_repository(void)
 }
 
 static struct alloc_state tag_state;
-void *alloc_tag_node(void)
+void *alloc_tag_node_the_repository(void)
 {
 	struct tag *t = alloc_node(&tag_state, sizeof(struct tag));
 	t->object.type = OBJ_TAG;

cache.h

@@ -1770,7 +1770,8 @@ extern void *alloc_blob_node_the_repository(void);
 extern void *alloc_tree_node_the_repository(void);
 #define alloc_commit_node(r) alloc_commit_node_##r()
 extern void *alloc_commit_node_the_repository(void);
-extern void *alloc_tag_node(void);
+#define alloc_tag_node(r) alloc_tag_node_##r()
+extern void *alloc_tag_node_the_repository(void);
 extern void *alloc_object_node(void);
 extern void alloc_report(void);
 extern unsigned int alloc_commit_index(void);

tag.c

@@ -94,7 +94,7 @@ struct tag *lookup_tag(const struct object_id *oid)
 	struct object *obj = lookup_object(oid->hash);
 	if (!obj)
 		return create_object(the_repository, oid->hash,
-				     alloc_tag_node());
+				     alloc_tag_node(the_repository));
 	return object_as_type(obj, OBJ_TAG, 0);
 }