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

> 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
> 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);