From: Junio C Hamano <gitster@pobox.com>
To: Stefan Beller <sbeller@google.com>
Cc: Patrick Lehmann <Patrick.Lehmann@plc2.de>,
Lars Schneider <larsxschneider@gmail.com>,
Git Mailinglist <git@vger.kernel.org>
Subject: Re: Restoring detached HEADs after Git operations
Date: Mon, 19 Jun 2017 10:55:07 -0700 [thread overview]
Message-ID: <xmqqefufuakk.fsf@gitster.mtv.corp.google.com> (raw)
In-Reply-To: <CAGZ79kY0gwk7KRY2iAVTXPBjPzx+mkciVWRR2z2cDgiBjQ2uuw@mail.gmail.com> (Stefan Beller's message of "Mon, 19 Jun 2017 09:37:01 -0700")
Stefan Beller <sbeller@google.com> writes:
> On Mon, Jun 19, 2017 at 2:52 AM, Patrick Lehmann
> <Patrick.Lehmann@plc2.de> wrote:
>> Hello Lars,
>>
>> for your questions:
>>> If there are multiple branches with the same hash then your script would pick the first one. Can you imagine a situation where this would be a problem?
>>
>> I can't think of a good solution to resolve it automatically. Maybe a script could print that there are multiple possibilities and it choose the first branch in the list.
>>
>>
>>> Plus, you are looking only at local branches. Wouldn't it make sense to look at remote branches, too?
>>
>> This is also related to restoring tags. If we go this way, we should have this priority list:
>> - local branches
>> - remote branches
>
> For remote branches you would create a local branch of the same name
> (if such a branch would not exist, possibly setting it up to track that remote
> branch)?
>
>> - tags
>
> as said in the other email and similar to remote branches, we'd not want to have
> HEAD pointing to them directly but somehow have a local branch.
Let's step back a bit. We detach the HEAD for a good reason, no?
Why is it a good idea to move them back on to a branch picked among
multiple ones that all happen to be pointing at the same commit?
The user may build on a history of a submodule, and then may push
the result out to a particular branch at the other side; that is
when being on a named branch in the submodule becomes useful, but
even then I do not think randomly picking one branch and be on it
is a good thing to do.
I would understand the workflow would go more like so:
- You do something at the superproject (e.g. create a new branch X
from an existing commit and check it out), which results in
submodules' HEADs getting detached at the commits bound to the
superproject's tree.
- Because you want to make changes to both submodules and the
superproject in a consistent way, you'd want to commit changes to
all of these repositories and the push the result out in an
atomic way.
- Hence you tell "Hey, Git, I want all the submodules that I
modified to be on branch X" from the superproject.
- This may succeed in a submodule where X is a new name, or the
current tip of branch X is an ancestor of the detached HEAD.
- This may fail in a submodule where there is branch X that does
not want to move to the detached HEAD's state. In this latter
case, the user needs to deal with the situation (perhaps the
old X is expendable; perhaps the HEAD's commit may need to be
merged to old X; perhaps there are other cases).
though.
next prev parent reply other threads:[~2017-06-19 17:55 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-19 8:46 Restoring detached HEADs after Git operations Patrick Lehmann
2017-06-19 9:30 ` Lars Schneider
2017-06-19 9:52 ` AW: " Patrick Lehmann
2017-06-19 16:37 ` Stefan Beller
2017-06-19 17:34 ` AW: " Patrick Lehmann
2017-06-19 17:47 ` Stefan Beller
2017-06-19 18:09 ` AW: " Patrick Lehmann
2017-06-19 19:21 ` Stefan Beller
2017-06-19 20:13 ` AW: " Patrick Lehmann
2017-06-19 17:55 ` Junio C Hamano [this message]
2017-06-19 19:11 ` Stefan Beller
2017-06-19 16:31 ` Stefan Beller
2017-06-19 17:01 ` Jeff King
2017-06-19 17:56 ` Ævar Arnfjörð Bjarmason
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