Re: [PATCH v2 13/13] commit-graph: specify OID version for SHA-256

> Since the commit-graph code wants to serialize the hash algorithm into
> the data store, specify a version number for each supported algorithm.
> Note that we don't use the values of the constants themselves, as they
> are internal and could change in the future.
>
> Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
> ---
>   commit-graph.c | 9 ++++++++-
>   1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/commit-graph.c b/commit-graph.c
> index 7a28fbb03f..e587c21bb6 100644
> --- a/commit-graph.c
> +++ b/commit-graph.c
> @@ -45,7 +45,14 @@ char *get_commit_graph_filename(const char *obj_dir)
>   
>   static uint8_t oid_version(void)
>   {
> -	return 1;
> +	switch (hash_algo_by_ptr(the_hash_algo)) {
> +		case GIT_HASH_SHA1:
> +			return 1;
> +		case GIT_HASH_SHA256:
> +			return 2;
> +		default:
> +			BUG("unknown hash algorithm");
> +	}
>   }
>   
>   static struct commit_graph *alloc_commit_graph(void)