git@vger.kernel.org mailing list mirror (one of many)
 help / color / mirror / code / Atom feed
From: Junio C Hamano <gitster@pobox.com>
To: Patrick Steinhardt <ps@pks.im>
Cc: git@vger.kernel.org, peff@peff.net
Subject: Re: [PATCH v2 4/4] update-ref: Disallow restart of ongoing transactions
Date: Mon, 09 Nov 2020 11:53:48 -0800	[thread overview]
Message-ID: <xmqqlffab92r.fsf@gitster.c.googlers.com> (raw)
In-Reply-To: <d9abffef71466a0752c210878bb6b8fca7a72287.1604908834.git.ps@pks.im> (Patrick Steinhardt's message of "Mon, 9 Nov 2020 11:07:01 +0100")

Patrick Steinhardt <ps@pks.im> writes:

> Subject: Re: [PATCH v2 4/4] update-ref: Disallow restart of ongoing transactions

Our convention (cf. "git shortlog --no-merges") is not to Capitalize
the first word after the "<area>:".  Shared across all four patches.

> It is currently possible to write multiple "start" commands into
> git-update-ref(1) for a single session, which doesn't make a lot of
> sense to do in the first place. It's also not quite obvious what should
> actually happen. Would this just go on with the current transaction as
> if nothing was written or would it recreate a new session which doesn't
> yet have any references? Silently ignoring this usage isn't helping
> either as it may indicate erroneous use of the interface.
>
> This commit catches this use and instead raises an error if the user is
> trying to restart an ongoing transaction.

Hmph, if you think of it as "restart", perhaps it would not make
sense, but in other contexts where the concept of "transactions" are
commonly used, it is not so unusual to support "nested" transactions
where inside an ongoing transaction, a subtransaction whose effect
can be rolled back as a whole, can be opened.  So wouldn't it be
more appropriate to explain this change like so?

    Since we do not support nested transactions, make sure a "start"
    command, seen after we saw "start" that is not closed by either
    "abort" or "commit", is flagged as an error.

> Signed-off-by: Patrick Steinhardt <ps@pks.im>
> ---
>  builtin/update-ref.c  |  2 ++
>  t/t1400-update-ref.sh | 11 +++++++++++
>  2 files changed, 13 insertions(+)
>
> diff --git a/builtin/update-ref.c b/builtin/update-ref.c
> index bb65129012..6029a80544 100644
> --- a/builtin/update-ref.c
> +++ b/builtin/update-ref.c
> @@ -436,6 +436,8 @@ static void update_refs_stdin(void)
>  		switch (state) {
>  		case UPDATE_REFS_OPEN:
>  		case UPDATE_REFS_STARTED:
> +			if (state == UPDATE_REFS_STARTED && cmd->state == UPDATE_REFS_STARTED)
> +				die("cannot restart ongoing transaction");
>  			/* Do not downgrade a transaction to a non-transaction. */
>  			if (cmd->state >= state)
>  				state = cmd->state;
> diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
> index 7ed41bb328..e53d973d04 100755
> --- a/t/t1400-update-ref.sh
> +++ b/t/t1400-update-ref.sh
> @@ -1583,4 +1583,15 @@ test_expect_success 'transaction can commit after abort' '
>  	test_cmp expect actual
>  '
>  
> +test_expect_success 'transaction cannot restart ongoing transaction' '
> +	cat >stdin <<-EOF &&
> +	start
> +	create refs/heads/restart $A
> +	start
> +	commit
> +	EOF
> +	test_must_fail git update-ref --stdin <stdin >actual &&
> +	test_must_fail git show-ref --verify refs/heads/restart
> +'
> +
>  test_done

  reply	other threads:[~2020-11-09 19:53 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-04 14:57 [PATCH 0/2] update-ref: Allow creation of multiple transactions Patrick Steinhardt
2020-11-04 14:57 ` [PATCH 1/2] " Patrick Steinhardt
2020-11-05 19:29   ` Jeff King
2020-11-05 21:34     ` Junio C Hamano
2020-11-06 17:52       ` Jeff King
2020-11-06 19:30         ` Junio C Hamano
2020-11-06  6:36     ` Patrick Steinhardt
2020-11-04 14:57 ` [PATCH 2/2] p1400: Use `git-update-ref --stdin` to test " Patrick Steinhardt
2020-11-05 19:34   ` Jeff King
2020-11-09 10:06 ` [PATCH v2 0/4] update-ref: Allow creation of " Patrick Steinhardt
2020-11-09 10:06   ` [PATCH v2 1/4] t1400: Avoid touching refs on filesystem Patrick Steinhardt
2020-11-09 19:48     ` Junio C Hamano
2020-11-09 22:28       ` Jeff King
2020-11-10 12:34       ` Patrick Steinhardt
2020-11-10 17:04         ` Junio C Hamano
2020-11-09 10:06   ` [PATCH v2 2/4] update-ref: Allow creation of multiple transactions Patrick Steinhardt
2020-11-09 10:06   ` [PATCH v2 3/4] p1400: Use `git-update-ref --stdin` to test " Patrick Steinhardt
2020-11-09 10:07   ` [PATCH v2 4/4] update-ref: Disallow restart of ongoing transactions Patrick Steinhardt
2020-11-09 19:53     ` Junio C Hamano [this message]
2020-11-09 22:33   ` [PATCH v2 0/4] update-ref: Allow creation of multiple transactions Jeff King
2020-11-09 22:38     ` Junio C Hamano
2020-11-11  6:58 ` [PATCH v3 0/4] update-ref: allow " Patrick Steinhardt
2020-11-11  6:58   ` [PATCH v3 1/4] t1400: avoid touching refs on filesystem Patrick Steinhardt
2020-11-11  9:04     ` SZEDER Gábor
2020-11-11 10:00       ` Patrick Steinhardt
2020-11-11 10:24         ` SZEDER Gábor
2020-11-11 23:06     ` Jeff King
2020-11-13  8:08       ` Patrick Steinhardt
2020-11-11  6:58   ` [PATCH v3 2/4] update-ref: allow creation of multiple transactions Patrick Steinhardt
2020-11-11  6:58   ` [PATCH v3 3/4] p1400: use `git-update-ref --stdin` to test " Patrick Steinhardt
2020-11-11  6:58   ` [PATCH v3 4/4] update-ref: disallow "start" for ongoing transactions Patrick Steinhardt
2020-11-13  8:12 ` [PATCH v4 0/4] update-ref: allow creation of multiple transactions Patrick Steinhardt
2020-11-13  8:12   ` [PATCH v4 1/4] t1400: avoid touching refs on filesystem Patrick Steinhardt
2020-11-13 20:40     ` Jeff King
2020-11-18  6:48       ` Patrick Steinhardt
2020-11-18  7:02         ` Junio C Hamano
2020-11-13  8:12   ` [PATCH v4 2/4] update-ref: allow creation of multiple transactions Patrick Steinhardt
2020-11-13  8:12   ` [PATCH v4 3/4] p1400: use `git-update-ref --stdin` to test " Patrick Steinhardt
2020-11-13  8:12   ` [PATCH v4 4/4] update-ref: disallow "start" for ongoing transactions Patrick Steinhardt
2020-11-25 22:37   ` [PATCH v4 0/4] update-ref: allow creation of multiple transactions Junio C Hamano
2020-11-26  0:42     ` Jeff King

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: http://vger.kernel.org/majordomo-info.html

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=xmqqlffab92r.fsf@gitster.c.googlers.com \
    --to=gitster@pobox.com \
    --cc=git@vger.kernel.org \
    --cc=peff@peff.net \
    --cc=ps@pks.im \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://80x24.org/mirrors/git.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).