From: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
To: Jeff King <peff@peff.net>
Cc: Robert Dailey <rcdailey.lists@gmail.com>, Git <git@vger.kernel.org>
Subject: Re: Strange annotated tag issue
Date: Mon, 25 Mar 2019 20:19:25 +0100 [thread overview]
Message-ID: <87tvfqbw3m.fsf@evledraar.gmail.com> (raw)
In-Reply-To: <20190325144930.GA19929@sigill.intra.peff.net>
On Mon, Mar 25 2019, Jeff King wrote:
> On Mon, Mar 25, 2019 at 08:50:14AM -0500, Robert Dailey wrote:
>
>> On Thu, Mar 21, 2019 at 2:29 PM Jeff King <peff@peff.net> wrote:
>> > Tags can point to any object, including another tag. It looks like
>> > somebody made an annotated tag of an annotated tag (probably by
>> > mistake, given that they have the same tag-name).
>> [..]
>> Thanks for explaining. This is very helpful. Am I naive to think that
>> this should be an error? I haven't seen a valid _pragmatic_ use for
>> tags pointing to tags. In 100% of cases (including this one), it is
>> done out of error. As per your example, users try to "correct" an
>> annotated tag pointing at a wrong tag or commit. What they expect is
>> the tag to point to the other tag's commit, but that's not what they
>> get.
>
> I don't think I've ever seen a tag-to-a-tag in the wild, but I wouldn't
> be surprised if somebody has found a use for it. For example, because
> tags can be signed, I can make a signature of your signature, showing a
> cryptographic chain of custody.
>
> And at any rate, it has been allowed in the data model for almost 15
> years, so I think disallowing it now would be a bad idea. It might be
> acceptable to introduce a safety valve into the porcelain, though.
>
>> From a high-level, pragmatic perspective, doesn't it make more sense
>> to change the git behavior so that annotated tags may only point to
>> commit objects? And in the `git tag -f -m outer mytag mytag` case in
>> your example, this would automatically perform `mytag^{}` to ensure
>> that the behavior the user expects is the behavior they get?
>
> I think "just commits" is too restrictive. linux.git contains a tag of a
> tree, for example (we also have tags pointing to blobs in git.git, but
> they are not annotated).
>
> However, I could see an argument for the git-tag porcelain to notice a
> tag-of-tag and complain. Probably peeling the tag automatically is a bad
> idea, just because it behaved differently for so long. But something
> like might be OK:
Sounds good!
> $ git tag -a mytag
> error: refusing to make a recursive tag
> hint: The object 'mytag' referred to by your new tag is already a tag.
> hint:
> hint: If you meant to create a tag of a tag, use:
> hint:
> hint: git tag -a -f mytag
> hint:
> hint: If you meant to tag the object that it points to, use:
> hint:
> hint: git tag -a mytag^{}
>
> It would be a minor annoyance to somebody who frequently makes
> tags-of-tags, but it leaves them with an escape hatch.
Let's call that something like --allow-recursive-tag (inspired by
'merge' --allow-unrelated-histories) so we don't confuse the desire to
create such a tag with clobbering an existing tag (which -f is
documented to do).
I was going to say "let's make the 'error:' part self-explanatory
without the 'hint:'" part, in case the advice was disabled. But looking
we only allow turning advice off on a per-variable basis, so I suspect
if someone bothered to do that they know about this already. Our
--allow-recursive-tag message is also fairly cryptic (and should, but
doesn't have, advice).
next prev parent reply other threads:[~2019-03-25 19:19 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-21 16:59 Strange annotated tag issue Robert Dailey
2019-03-21 19:04 ` Bryan Turner
2019-03-21 19:39 ` Jeff King
2019-03-21 19:29 ` Jeff King
2019-03-25 13:50 ` Robert Dailey
2019-03-25 14:49 ` Jeff King
2019-03-25 15:31 ` Robert Dailey
2019-03-25 18:43 ` Bryan Turner
2019-03-25 23:36 ` Jeff King
2019-03-25 19:19 ` Ævar Arnfjörð Bjarmason [this message]
2019-03-25 23:37 ` Jeff King
2019-03-26 7:53 ` [PATCH 0/3] tag: prevent recursive tags Denton Liu
2019-03-26 7:53 ` [PATCH 1/3] " Denton Liu
2019-03-26 8:51 ` Denton Liu
2019-03-26 10:10 ` Ævar Arnfjörð Bjarmason
2019-03-27 4:57 ` Elijah Newren
2019-03-27 10:27 ` Ævar Arnfjörð Bjarmason
2019-03-28 19:02 ` Robert Dailey
2019-03-26 7:53 ` [PATCH 2/3] t7004: ensure recursive tag behavior is working Denton Liu
2019-03-26 10:11 ` Ævar Arnfjörð Bjarmason
2019-03-26 7:53 ` [PATCH 3/3] git-tag.txt: document --allow-recursive-tag option Denton Liu
2019-03-26 10:16 ` Ævar Arnfjörð Bjarmason
2019-03-26 16:18 ` [PATCH 0/3] tag: prevent recursive tags Jeff King
2019-04-02 5:38 ` [PATCH v2 0/2] tag: prevent nested tags Denton Liu
2019-04-02 5:38 ` [PATCH v2 1/2] tag: fix formatting Denton Liu
2019-04-02 5:38 ` [PATCH v2 2/2] tag: prevent nested tags Denton Liu
2019-04-02 23:03 ` [PATCH v2.5 " Denton Liu
2019-04-03 7:32 ` Junio C Hamano
2019-04-03 8:49 ` Junio C Hamano
2019-04-03 18:26 ` Robert Dailey
2019-04-04 9:32 ` Junio C Hamano
2019-04-04 13:47 ` Robert Dailey
2019-04-04 21:50 ` Junio C Hamano
2019-04-05 2:51 ` Robert Dailey
2019-04-03 18:16 ` Johannes Sixt
2019-04-03 21:33 ` Denton Liu
2019-04-04 2:02 ` Jeff King
2019-04-04 9:31 ` Junio C Hamano
2019-04-04 12:27 ` Jeff King
2019-04-04 21:54 ` Junio C Hamano
2019-04-04 22:12 ` Jeff King
2019-04-11 18:40 ` Eckhard Maaß
2019-04-12 3:21 ` Junio C Hamano
2019-04-05 0:36 ` Elijah Newren
2019-04-05 5:29 ` Junio C Hamano
2019-04-04 18:25 ` [PATCH v3 0/2] tag: advise on recursive tagging Denton Liu
2019-04-04 18:25 ` [PATCH v3 1/2] tag: fix formatting Denton Liu
2019-04-04 18:25 ` [PATCH v3 2/2] tag: advise on nested tags Denton Liu
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=87tvfqbw3m.fsf@evledraar.gmail.com \
--to=avarab@gmail.com \
--cc=git@vger.kernel.org \
--cc=peff@peff.net \
--cc=rcdailey.lists@gmail.com \
/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).