ALLOC_GROW(it->down, it->subtree_nr + 1, it->subtree_alloc);
        it->subtree_nr++;
 
-       down = xmalloc(sizeof(*down) + pathlen + 1);
+       FLEX_ALLOC_MEM(down, name, path, pathlen);
        down->cache_tree = NULL;
        down->namelen = pathlen;
-       memcpy(down->name, path, pathlen);
-       down->name[pathlen] = 0;
 
        if (pos < it->subtree_nr)
                memmove(it->down + pos + 1,