Re: [PATCH v2] pack-redundant: fix crash when one packfile in repo

[Junio C Hamano <gitster@pobox.com>]

Jiang Xin <worldhello.net@gmail.com> writes:

> From: Jiang Xin <zhiyou.jx@alibaba-inc.com>
>
> Command `git pack-redundant --all` will crash if there is only one
> packfile in the repository.  This is because, if there is only one
> packfile in local_packs, `cmp_local_packs` will do nothing and will
> leave `pl->unique_objects` as uninitialized.
>
> Also add testcases for repository with no packfile and one packfile
> in t5323.
>
> Reported-by: Daniel C. Klauer <daniel.c.klauer@web.de>
> Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
> ---
>  builtin/pack-redundant.c  |  6 ++++++
>  t/t5323-pack-redundant.sh | 37 +++++++++++++++++++++++++++++++++----
>  2 files changed, 39 insertions(+), 4 deletions(-)

Thanks.

>
> diff --git a/builtin/pack-redundant.c b/builtin/pack-redundant.c
> index 178e3409b7..690775fa82 100644
> --- a/builtin/pack-redundant.c
> +++ b/builtin/pack-redundant.c
> @@ -473,6 +473,12 @@ static void cmp_local_packs(void)
>  {
>  	struct pack_list *subset, *pl = local_packs;
>  
> +	/* only one packfile */
> +	if (!pl->next) {
> +		llist_init(&pl->unique_objects);
> +		return;
> +	}
> +
>  	while ((subset = pl)) {
>  		while ((subset = subset->next))
>  			cmp_two_packs(pl, subset);
> diff --git a/t/t5323-pack-redundant.sh b/t/t5323-pack-redundant.sh
> index 6b4d1ca353..7e3340843f 100755
> --- a/t/t5323-pack-redundant.sh
> +++ b/t/t5323-pack-redundant.sh
> @@ -112,19 +112,28 @@ test_expect_success 'setup master repo' '
>  	create_commits_in "$master_repo" A B C D E F G H I J K L M N O P Q R
>  '
>  
> +test_expect_success 'master: pack-redundant works with no packfile' '
> +	(
> +		cd "$master_repo" &&
> +		cat >expect <<-EOF &&
> +			fatal: Zero packs found!
> +			EOF
> +		test_must_fail git pack-redundant --all >actual 2>&1 &&
> +		test_cmp expect actual
> +	)
> +'
> +
>  #############################################################################
>  # Chart of packs and objects for this test case
>  #
>  #         | T A B C D E F G H I J K L M N O P Q R
>  #     ----+--------------------------------------
>  #     P1  | x x x x x x x                       x
> -#     P2  |     x x x x   x x x
> -#     P3  |             x     x x x x x
>  #     ----+--------------------------------------
> -#     ALL | x x x x x x x x x x x x x x         x
> +#     ALL | x x x x x x x                       x
>  #
>  #############################################################################
> -test_expect_success 'master: no redundant for pack 1, 2, 3' '
> +test_expect_success 'master: pack-redundant works with one packfile' '
>  	create_pack_in "$master_repo" P1 <<-EOF &&
>  		$T
>  		$A
> @@ -135,6 +144,26 @@ test_expect_success 'master: no redundant for pack 1, 2, 3' '
>  		$F
>  		$R
>  		EOF
> +	(
> +		cd "$master_repo" &&
> +		git pack-redundant --all >out &&
> +		test_must_be_empty out
> +	)
> +'
> +
> +#############################################################################
> +# Chart of packs and objects for this test case
> +#
> +#         | T A B C D E F G H I J K L M N O P Q R
> +#     ----+--------------------------------------
> +#     P1  | x x x x x x x                       x
> +#     P2  |     x x x x   x x x
> +#     P3  |             x     x x x x x
> +#     ----+--------------------------------------
> +#     ALL | x x x x x x x x x x x x x x         x
> +#
> +#############################################################################
> +test_expect_success 'master: no redundant for pack 1, 2, 3' '
>  	create_pack_in "$master_repo" P2 <<-EOF &&
>  		$B
>  		$C