> +static void free_commit_graph(struct commit_graph **g)
> +{
> + if (!g || !*g)
> + return;
> +
> + close_commit_graph(*g);
> +
> + free(*g);
> + *g = NULL;nit: You may want to use FREE_AND_NULL(*g) instead.
> +static void free_commit_graph(struct commit_graph **g)
> +{
> + if (!g || !*g)
> + return;
> +
> + close_commit_graph(*g);
> +
> + free(*g);
> + *g = NULL;nit: You may want to use FREE_AND_NULL(*g) instead.