struct notes_tree default_notes_tree;
 
-static struct string_list display_notes_refs;
+static struct string_list display_notes_refs = STRING_LIST_INIT_NODUP;
 static struct notes_tree **display_notes_trees;
 
 static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
                        l = (struct leaf_node *)
                                xcalloc(1, sizeof(struct leaf_node));
                        hashcpy(l->key_sha1, object_sha1);
-                       hashcpy(l->val_sha1, entry.sha1);
+                       hashcpy(l->val_sha1, entry.oid->hash);
                        if (len < 20) {
                                if (!S_ISDIR(entry.mode) || path_len != 2)
                                        goto handle_non_note; /* not subtree */
                        }
                        strbuf_addstr(&non_note_path, entry.path);
                        add_non_note(t, strbuf_detach(&non_note_path, NULL),
-                                    entry.mode, entry.sha1);
+                                    entry.mode, entry.oid->hash);
                }
        }
        free(buf);
 void init_notes(struct notes_tree *t, const char *notes_ref,
                combine_notes_fn combine_notes, int flags)
 {
-       unsigned char sha1[20], object_sha1[20];
+       struct object_id oid, object_oid;
        unsigned mode;
        struct leaf_node root_tree;
 
        t->dirty = 0;
 
        if (flags & NOTES_INIT_EMPTY || !notes_ref ||
-           get_sha1_treeish(notes_ref, object_sha1))
+           get_sha1_treeish(notes_ref, object_oid.hash))
                return;
-       if (flags & NOTES_INIT_WRITABLE && read_ref(notes_ref, object_sha1))
+       if (flags & NOTES_INIT_WRITABLE && read_ref(notes_ref, object_oid.hash))
                die("Cannot use notes ref %s", notes_ref);
-       if (get_tree_entry(object_sha1, "", sha1, &mode))
+       if (get_tree_entry(object_oid.hash, "", oid.hash, &mode))
                die("Failed to read notes tree referenced by %s (%s)",
-                   notes_ref, sha1_to_hex(object_sha1));
+                   notes_ref, oid_to_hex(&object_oid));
 
        hashclr(root_tree.key_sha1);
-       hashcpy(root_tree.val_sha1, sha1);
+       hashcpy(root_tree.val_sha1, oid.hash);
        load_subtree(t, &root_tree, t->root, 0);
 }