Re: [PATCH 3/4] object-name: reject trees found in the index

> From: Derrick Stolee <derrickstolee@github.com>
> 
> The get_oid_with_context_1() method is used when parsing revision
> arguments. One particular case is to take a ":<path>" string and search
> the index for the given path.
> 
> In the case of a sparse index, this might find a sparse directory entry,
> in which case the contained object is a tree. In the case of a full
> index, this search within the index would fail.

> In order to maintain identical return state as in a full index, inspect
> the discovered cache entry to see if it is a sparse directory and reject
> it. This requires being careful around the only_to_die option to be sure
> we die only at the correct time.
> 
> This changes the behavior of 'git show :<sparse-dir>', but does not
> bring it entirely into alignment with a full index case. It specifically
> hits the wrong error message within diagnose_invalid_index_path(). That
> error message will be corrected in a future change.
> 
> Signed-off-by: Derrick Stolee <derrickstolee@github.com>
> ---
>  object-name.c                            | 19 ++++++++++++++++++-
>  t/t1092-sparse-checkout-compatibility.sh | 11 ++---------
>  2 files changed, 20 insertions(+), 10 deletions(-)
> 
> diff --git a/object-name.c b/object-name.c
> index f0e327f91f5..2dc5d2549b8 100644
> --- a/object-name.c
> +++ b/object-name.c
> @@ -1881,6 +1881,20 @@ static char *resolve_relative_path(struct repository *r, const char *rel)
>  			   rel);
>  }
>  
> +static int reject_tree_in_index(struct repository *repo,
> +				int only_to_die,
> +				const struct cache_entry *ce,
> +				int stage,
> +				const char *prefix,
> +				const char *cp)
> +{
> +	if (!S_ISSPARSEDIR(ce->ce_mode))
> +		return 0;
> +	if (only_to_die)
> +		diagnose_invalid_index_path(repo, stage, prefix, cp);
> +	return -1;
> +}
> +
>  static enum get_oid_result get_oid_with_context_1(struct repository *repo,
>  				  const char *name,
>  				  unsigned flags,
> @@ -1955,9 +1969,12 @@ static enum get_oid_result get_oid_with_context_1(struct repository *repo,
>  			    memcmp(ce->name, cp, namelen))
>  				break;
>  			if (ce_stage(ce) == stage) {
> +				free(new_path);
> +				if (reject_tree_in_index(repo, only_to_die, ce,
> +							 stage, prefix, cp))
> +					return -1;
>  				oidcpy(oid, &ce->oid);
>  				oc->mode = ce->ce_mode;
> -				free(new_path);
>  				return 0;
>  			}
>  			pos++;
> diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
> index f6a14e08b81..9d32361110d 100755
> --- a/t/t1092-sparse-checkout-compatibility.sh
> +++ b/t/t1092-sparse-checkout-compatibility.sh
> @@ -1164,15 +1164,8 @@ test_expect_success 'show (cached blobs/trees)' '
>  	test_must_fail git -C full-checkout show :folder1/ &&
>  	test_must_fail git -C sparse-checkout show :folder1/ &&
>  
> -	git -C sparse-index show :folder1/ >actual &&
> -	git -C full-checkout show HEAD:folder1 >expect &&
> -
> -	# The output of "git show" includes the way we referenced the
> -	# objects, so strip that out.
> -	test_line_count = 4 actual &&
> -	tail -n 2 actual >actual-trunc &&
> -	tail -n 2 expect >expect-trunc &&
> -	test_cmp expect-trunc actual-trunc
> +	test_must_fail git -C sparse-index show :folder1/ 2>err &&
> +	grep "is in the index, but not at stage 0" err
>  '

>  
>  test_expect_success 'submodule handling' '
> -- 
> gitgitgadget
>