Re: [PATCH 03/30] object-names: Support input of oids in any supported hash

> Support short oids encoded in any algorithm, while ensuring enough of
> the oid is specified to disambiguate between all of the oids in the
> repository encoded in any algorithm.
>
> By default have the code continue to only accept oids specified in the
> storage hash algorithm of the repository, but when something is
> ambiguous display all of the possible oids from any oid encoding.
>
> A new flag is added GET_OID_HASH_ANY that when supplied causes the
> code to accept oids specified in any hash algorithm, and to return the
> oids that were resolved.
>
> This implements the functionality that allows both SHA-1 and SHA-256
> object names, from the "Object names on the command line" section of
> the hash function transition document.
>
> Care is taken in get_short_oid so that when the result is ambiguous
> the output remains the same of GIT_OID_HASH_ANY was not supplied.

> If GET_OID_HASH_ANY was supplied objects of any hash algorithm
> that match the prefix are displayed.
>
> This required updating repo_for_each_abbrev to give it a parameter
> so that it knows to look at all hash algorithms.
>
> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
> ---
> diff --git a/object-name.c b/object-name.c
> @@ -49,6 +50,7 @@ struct disambiguate_state {
>  static void update_candidates(struct disambiguate_state *ds, const struct object_id *current)
>  {
> +       /* The hash algorithm of the current has already been filtered */

> @@ -503,8 +516,13 @@ static int sort_ambiguous(const void *a, const void *b, void *ctx)
> -       if (a_type == b_type)
> -               return oidcmp(a, b);
> +       if (a_type == b_type) {
> +               /* Is the hash algorithm the same? */
> +               if (a->algo == b->algo)
> +                       return oidcmp(a, b);
> +               else
> +                       return a->algo > b->algo ? 1 : -1;
> +       }

> @@ -553,6 +575,7 @@ static enum get_oid_result get_short_oid(struct repository *r,
>         else
>                 ds.fn = default_disambiguate_hint;
>
> +
>         find_short_object_filename(&ds);