Re: [PATCH 07/11] bundle: safely handle --objects option

[Jeff Hostetler <git@jeffhostetler.com>]

On 2/23/22 12:55 PM, Derrick Stolee via GitGitGadget wrote:
> From: Derrick Stolee <derrickstolee@github.com>
> 
> Since 'git bundle' uses setup_revisions() to specify the object walk,
> some options do not make sense to include during the pack-objects child
> process. Further, these options are used for a call to
> traverse_commit_list() which would then require a callback which is
> currently NULL.
> 
> By populating the callback we prevent a segfault in the case of adding
> the --objects flag. This is really a redundant statement because the

Nit: I stumbled over "...because the bundles are constructing..."
Is there a better wording here??

> bundles are constructing a pack-file containing all objects in the
> discovered commit range.
> 
> Adding --objects to a 'git bundle' command might cause a slower command,
> but at least it will not have a hard failure when the user supplies this
> option. We can also disable walking trees and blobs in advance of this
> walk.
> 
> Signed-off-by: Derrick Stolee <derrickstolee@github.com>
> ---
>   bundle.c               | 10 +++++++++-
>   t/t6020-bundle-misc.sh | 12 ++++++++++++
>   2 files changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/bundle.c b/bundle.c
> index a0bb687b0f4..dc56db9a50a 100644
> --- a/bundle.c
> +++ b/bundle.c
> @@ -451,6 +451,12 @@ struct bundle_prerequisites_info {
>   	int fd;
>   };
>   
> +
> +static void ignore_object(struct object *obj, const char *v, void *data)
> +{
> +	/* Do nothing. */
> +}
> +
>   static void write_bundle_prerequisites(struct commit *commit, void *data)
>   {
>   	struct bundle_prerequisites_info *bpi = data;
> @@ -544,7 +550,9 @@ int create_bundle(struct repository *r, const char *path,
>   		die("revision walk setup failed");
>   	bpi.fd = bundle_fd;
>   	bpi.pending = &revs_copy.pending;
> -	traverse_commit_list(&revs, write_bundle_prerequisites, NULL, &bpi);
> +
> +	revs.blob_objects = revs.tree_objects = 0;
> +	traverse_commit_list(&revs, write_bundle_prerequisites, ignore_object, &bpi);
>   	object_array_remove_duplicates(&revs_copy.pending);
>   
>   	/* write bundle refs */
> diff --git a/t/t6020-bundle-misc.sh b/t/t6020-bundle-misc.sh
> index b13e8a52a93..6522401617d 100755
> --- a/t/t6020-bundle-misc.sh
> +++ b/t/t6020-bundle-misc.sh
> @@ -475,4 +475,16 @@ test_expect_success 'clone from bundle' '
>   	test_cmp expect actual
>   '
>   
> +test_expect_success 'unfiltered bundle with --objects' '
> +	git bundle create all-objects.bdl \
> +		--all --objects &&
> +	git bundle create all.bdl \
> +		--all &&
> +
> +	# Compare the headers of these files.
> +	head -11 all.bdl >expect &&
> +	head -11 all-objects.bdl >actual &&
> +	test_cmp expect actual
> +'
> +
>   test_done
>