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From: Junio C Hamano <gitster@pobox.com>
To: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
Cc: Glen Choo <chooglen@google.com>,
	git@vger.kernel.org, Jonathan Tan <jonathantanmy@google.com>,
	Josh Steadmon <steadmon@google.com>,
	Emily Shaffer <emilyshaffer@google.com>,
	Philippe Blain <levraiphilippeblain@gmail.com>
Subject: Re: [PATCH v3 5/5] branch.c: replace questionable exit() codes
Date: Mon, 13 Dec 2021 11:26:29 -0800	[thread overview]
Message-ID: <xmqqzgp4b922.fsf@gitster.g> (raw)
In-Reply-To: <211213.8635mwamah.gmgdl@evledraar.gmail.com> ("Ævar Arnfjörð Bjarmason"'s message of "Mon, 13 Dec 2021 10:19:16 +0100")

Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:

> On Mon, Dec 13 2021, Junio C Hamano wrote:
>
>> Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:
>>
>>> The latter should really be "exit(1)", not 128. We should reserve that
>>> for die().
>>
>> Is it because install_branch_config_multiple_remotes() gives enough
>> information to the user that the caller exits without its own
>> message?  In other words, are messages given by the callee to the
>> users are morally equivalent to what the caller would call die()
>> with, if the callee were silent?  If so, 128 is perfectly fine.  If
>> not, 1 or anything positive that is not 128 may be more appropriate.
>
> We don't really document this outside of this tidbit:
>     
>     Documentation/technical/api-error-handling.txt-- `die` is for fatal application errors.  It prints a message to
>     Documentation/technical/api-error-handling.txt:  the user and exits with status 128.
>     Documentation/technical/api-error-handling.txt-
>     Documentation/technical/api-error-handling.txt-- `usage` is for errors in command line usage.  After printing its
>     Documentation/technical/api-error-handling.txt-  message, it exits with status 129.  (See also `usage_with_options`
>     Documentation/technical/api-error-handling.txt-  in the link:api-parse-options.html[parse-options API].)
>
> But while that doesn't say that you can *only* use 128 for die, and I
> wouldn't consider the existing code that calls exit(128) in dire need of
> a change, most of the builtins simply return with 1 for generic errors,
> and reserve 128 for die()..
>
> So for any new code it makes sense to follow that convention.

Only when they are not calling die() for some technical reasons,
though.  IOW, if you would have called die() if you could, that is a
good indication that you would want to consistently use 128.

Capturing return value from die_message(), giving more message and
then dying with the 128 squarely falls into that pattern.  I am not
sure if the install_branch_config_multiple_remotes() case falls into
it, though.

And more importantly in the context of this topic, I am not
convinced install_branch_config_multiple_remotes() helper function
itself is a good idea to begin with.  It is to handle a case where
branch.$name.remote is set multiple times right?

This is because I do not think I saw anybody defined the right
semantics during the discussion (or written in the documentation)
and explained why being able to do so makes sense in the first
place, and it is not known if it makes sense to copy such a
configuration blindly to a new branch.  If it punts without doing
anything with a warning(), or calls a die(), it would be a more
sensible first step for this topic.  Users with real need for such a
configuration will then come to us with real use case, and what they
need may turn out to be something different from a blind copying of
the original.

Thanks.




  reply	other threads:[~2021-12-13 19:26 UTC|newest]

Thread overview: 110+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-22 22:32 [PATCH 0/4] implement branch --recurse-submodules Glen Choo
2021-11-22 22:32 ` [PATCH 1/4] submodule-config: add submodules_of_tree() helper Glen Choo
2021-11-23  2:12   ` Jonathan Tan
2021-11-23 19:48     ` Glen Choo
2021-11-23 10:53   ` Ævar Arnfjörð Bjarmason
2021-11-23 18:35     ` Glen Choo
2021-11-23 22:46   ` Junio C Hamano
2021-11-22 22:32 ` [PATCH 2/4] branch: refactor out branch validation from create_branch() Glen Choo
2021-11-22 22:32 ` [PATCH 3/4] branch: add --dry-run option to branch Glen Choo
2021-11-23 10:42   ` Ævar Arnfjörð Bjarmason
2021-11-23 18:42     ` Glen Choo
2021-11-23 23:10   ` Jonathan Tan
2021-11-24  0:52     ` Glen Choo
2021-11-22 22:32 ` [PATCH 4/4] branch: add --recurse-submodules option for branch creation Glen Choo
2021-11-23 10:45   ` Ævar Arnfjörð Bjarmason
2021-11-23 18:56     ` Glen Choo
2021-11-23 19:41   ` Philippe Blain
2021-11-23 23:43     ` Glen Choo
2021-11-24  1:31   ` Jonathan Tan
2021-11-24 18:18     ` Glen Choo
2021-11-29 21:01       ` Jonathan Tan
2021-12-06 21:55 ` [PATCH v2 0/3] implement branch --recurse-submodules Glen Choo
2021-12-06 21:55   ` [PATCH v2 1/3] branch: move --set-upstream-to behavior to setup_tracking() Glen Choo
2021-12-06 22:48     ` Junio C Hamano
2021-12-08 18:48       ` Glen Choo
2021-12-06 23:28     ` Junio C Hamano
2021-12-08 17:09       ` Glen Choo
2021-12-06 21:55   ` [PATCH v2 2/3] builtin/branch: clean up action-picking logic in cmd_branch() Glen Choo
2021-12-06 21:55   ` [PATCH v2 3/3] branch: add --recurse-submodules option for branch creation Glen Choo
2021-12-09 18:49   ` [PATCH v3 0/5] implement branch --recurse-submodules Glen Choo
2021-12-09 18:49     ` [PATCH v3 1/5] branch: move --set-upstream-to behavior to setup_tracking() Glen Choo
2021-12-09 21:19       ` Jonathan Tan
2021-12-09 22:16         ` Glen Choo
2021-12-09 18:49     ` [PATCH v3 2/5] branch: remove forward declaration of validate_branch_start() Glen Choo
2021-12-09 18:49     ` [PATCH v3 3/5] builtin/branch: clean up action-picking logic in cmd_branch() Glen Choo
2021-12-09 21:23       ` Jonathan Tan
2021-12-09 21:57         ` Glen Choo
2021-12-09 18:49     ` [PATCH v3 4/5] branch: add --recurse-submodules option for branch creation Glen Choo
2021-12-11 18:08       ` Philippe Blain
2021-12-14 20:08         ` Glen Choo
2021-12-09 18:49     ` [PATCH v3 5/5] branch.c: replace questionable exit() codes Glen Choo
2021-12-10  2:21       ` Ævar Arnfjörð Bjarmason
2021-12-10 17:43         ` Glen Choo
2021-12-13  9:02         ` Junio C Hamano
2021-12-13  9:19           ` Ævar Arnfjörð Bjarmason
2021-12-13 19:26             ` Junio C Hamano [this message]
2021-12-09 21:59     ` [PATCH v3 0/5] implement branch --recurse-submodules Jonathan Tan
2021-12-09 22:21       ` Glen Choo
2021-12-13 23:20         ` Jonathan Tan
2021-12-14 18:47           ` Glen Choo
2021-12-16  0:32     ` [PATCH v4 " Glen Choo
2021-12-16  0:32       ` [PATCH v4 1/5] branch: move --set-upstream-to behavior to dwim_and_setup_tracking() Glen Choo
2021-12-16  0:32       ` [PATCH v4 2/5] branch: make create_branch() always create a branch Glen Choo
2021-12-16  0:32       ` [PATCH v4 3/5] branch: add a dry_run parameter to create_branch() Glen Choo
2021-12-16  0:32       ` [PATCH v4 4/5] builtin/branch: clean up action-picking logic in cmd_branch() Glen Choo
2021-12-16  0:32       ` [PATCH v4 5/5] branch: add --recurse-submodules option for branch creation Glen Choo
2021-12-16 23:33       ` [PATCH v5 0/5] implement branch --recurse-submodules Glen Choo
2021-12-16 23:33         ` [PATCH v5 1/5] branch: move --set-upstream-to behavior to dwim_and_setup_tracking() Glen Choo
2021-12-16 23:33         ` [PATCH v5 2/5] branch: make create_branch() always create a branch Glen Choo
2021-12-16 23:33         ` [PATCH v5 3/5] branch: add a dry_run parameter to create_branch() Glen Choo
2021-12-16 23:33         ` [PATCH v5 4/5] builtin/branch: clean up action-picking logic in cmd_branch() Glen Choo
2021-12-16 23:33         ` [PATCH v5 5/5] branch: add --recurse-submodules option for branch creation Glen Choo
2021-12-17  0:34         ` [PATCH v5 0/5] implement branch --recurse-submodules Junio C Hamano
2021-12-17  0:45           ` Junio C Hamano
2021-12-20 19:09             ` Glen Choo
2021-12-20 19:50               ` Junio C Hamano
2021-12-20 20:25                 ` Glen Choo
2021-12-20 23:34         ` [PATCH v6 " Glen Choo
2021-12-20 23:34           ` [PATCH v6 1/5] branch: move --set-upstream-to behavior to dwim_and_setup_tracking() Glen Choo
2022-01-11  2:09             ` Jonathan Tan
2022-01-11 17:29               ` Glen Choo
2022-01-11 20:03                 ` Jonathan Tan
2021-12-20 23:34           ` [PATCH v6 2/5] branch: make create_branch() always create a branch Glen Choo
2022-01-11  2:19             ` Jonathan Tan
2022-01-11 17:51               ` Glen Choo
2021-12-20 23:34           ` [PATCH v6 3/5] branch: add a dry_run parameter to create_branch() Glen Choo
2021-12-20 23:34           ` [PATCH v6 4/5] builtin/branch: clean up action-picking logic in cmd_branch() Glen Choo
2021-12-20 23:34           ` [PATCH v6 5/5] branch: add --recurse-submodules option for branch creation Glen Choo
2021-12-26  4:09             ` Junio C Hamano
2022-01-11  3:28             ` Jonathan Tan
2022-01-11 18:11               ` Glen Choo
2022-01-11 20:15                 ` Jonathan Tan
2022-01-11 23:22                   ` Glen Choo
2021-12-20 23:36           ` [PATCH v6 0/5] implement branch --recurse-submodules Glen Choo
2021-12-21  1:07           ` Junio C Hamano
2021-12-21 17:51             ` Glen Choo
2022-01-24 20:44           ` [PATCH v7 0/6] " Glen Choo
2022-01-24 20:44             ` [PATCH v7 1/6] branch: move --set-upstream-to behavior to dwim_and_setup_tracking() Glen Choo
2022-01-24 20:44             ` [PATCH v7 2/6] branch: make create_branch() always create a branch Glen Choo
2022-01-24 20:44             ` [PATCH v7 3/6] branch: add a dry_run parameter to create_branch() Glen Choo
2022-01-24 20:44             ` [PATCH v7 4/6] builtin/branch: consolidate action-picking logic in cmd_branch() Glen Choo
2022-01-24 20:44             ` [PATCH v7 5/6] branch: add --recurse-submodules option for branch creation Glen Choo
2022-01-27 20:29               ` Jonathan Tan
2022-01-27 21:32                 ` Glen Choo
2022-01-27 22:42                   ` Glen Choo
2022-01-24 20:44             ` [PATCH v7 6/6] branch.c: use 'goto cleanup' in setup_tracking() to fix memory leaks Glen Choo
2022-01-27 22:15               ` Junio C Hamano
2022-01-28 19:44                 ` Glen Choo
2022-01-29  0:04             ` [PATCH v8 0/6] implement branch --recurse-submodules Glen Choo
2022-01-29  0:04               ` [PATCH v8 1/6] branch: move --set-upstream-to behavior to dwim_and_setup_tracking() Glen Choo
2022-01-29  0:04               ` [PATCH v8 2/6] branch: make create_branch() always create a branch Glen Choo
2022-02-01 22:20                 ` Junio C Hamano
2022-01-29  0:04               ` [PATCH v8 3/6] branch: add a dry_run parameter to create_branch() Glen Choo
2022-01-29  0:04               ` [PATCH v8 4/6] builtin/branch: consolidate action-picking logic in cmd_branch() Glen Choo
2022-01-29  0:04               ` [PATCH v8 5/6] branch: add --recurse-submodules option for branch creation Glen Choo
2022-02-04  1:10                 ` Glen Choo
2022-02-04 16:15                   ` Junio C Hamano
2022-02-04 18:10                     ` Glen Choo
2022-01-29  0:04               ` [PATCH v8 6/6] branch.c: use 'goto cleanup' in setup_tracking() to fix memory leaks Glen Choo
2022-02-01 17:43               ` [PATCH v8 0/6] implement branch --recurse-submodules Jonathan Tan

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