n = q->avl_link[dir] = tree->avl_alloc->libavl_malloc (tree->avl_alloc, sizeof *n); if (n == NULL) return NULL; tree->avl_count++; n->avl_data = item; n->avl_link[0] = n->avl_link[1] = NULL; n->avl_balance = 0; if (y == NULL) return &n->avl_data;