* bug?: ORIG_HEAD incorrect after reset during git-rebase -i
@ 2021-12-16 14:30 Erik Cervin Edin
2021-12-16 16:27 ` Phillip Wood
0 siblings, 1 reply; 7+ messages in thread
From: Erik Cervin Edin @ 2021-12-16 14:30 UTC (permalink / raw)
To: git
Steps to reproduce:
1. git-rebase -i
2. edit XYZ
3. git-reset HEAD~
4. git-commit -C ORIG_HEAD -a
5. git-rebase --continue
6. git-show ORIG_HEAD
Expected behavior:
ORIG_HEAD should point at the previous HEAD of the rebased branch
Actual behavior:
ORIG_HEAD points to XYZ
My understanding from reading https://stackoverflow.com/a/64949884 is
that this is incorrect behavior.
Perhaps this is as intended but I would at least personally prefer
that ORIG_HEAD would point to the previous HEAD of the rebased branch.
Seen in:
git version 2.31.1.windows.1
Possibly related to
e100bea481 - rebase -i: stop overwriting ORIG_HEAD buffer
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: bug?: ORIG_HEAD incorrect after reset during git-rebase -i
2021-12-16 14:30 bug?: ORIG_HEAD incorrect after reset during git-rebase -i Erik Cervin Edin
@ 2021-12-16 16:27 ` Phillip Wood
2021-12-16 16:44 ` Erik Cervin Edin
0 siblings, 1 reply; 7+ messages in thread
From: Phillip Wood @ 2021-12-16 16:27 UTC (permalink / raw)
To: Erik Cervin Edin, git
Hi Erik
On 16/12/2021 14:30, Erik Cervin Edin wrote:
> Steps to reproduce:
> 1. git-rebase -i
> 2. edit XYZ
> 3. git-reset HEAD~
"git reset" will update ORIG_HEAD to the current HEAD before resetting
so here ORIG_HEAD gets updated to point to XYZ
> 4. git-commit -C ORIG_HEAD -a
> 5. git-rebase --continue
> 6. git-show ORIG_HEAD
>
> Expected behavior:
> ORIG_HEAD should point at the previous HEAD of the rebased branch
>
> Actual behavior:
> ORIG_HEAD points to XYZ
>
> My understanding from reading https://stackoverflow.com/a/64949884 is
> that this is incorrect behavior.
>
> Perhaps this is as intended but I would at least personally prefer
> that ORIG_HEAD would point to the previous HEAD of the rebased branch.
You can use the reflog to get the previous HEAD of the rebased branch
after rebasing. Immediately after the rebase branch-name@{1} will point
to the pre-rebase HEAD.
Best Wishes
Phillip
> Seen in:
> git version 2.31.1.windows.1
>
> Possibly related to
> e100bea481 - rebase -i: stop overwriting ORIG_HEAD buffer
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: bug?: ORIG_HEAD incorrect after reset during git-rebase -i
2021-12-16 16:27 ` Phillip Wood
@ 2021-12-16 16:44 ` Erik Cervin Edin
2023-01-05 0:11 ` Philippe Blain
0 siblings, 1 reply; 7+ messages in thread
From: Erik Cervin Edin @ 2021-12-16 16:44 UTC (permalink / raw)
To: phillip.wood; +Cc: git
Hi Phillip,
Yes, I know.
It's just that I was under the impression ORIG_HEAD was to be reverted
to .git/rebase-merge/orig-head at the finish of the rebase.
Personally, it's the behavior I would expect.
Thanks for the tips.
Regards,
Erik
On Thu, Dec 16, 2021 at 5:27 PM Phillip Wood <phillip.wood@talktalk.net> wrote:
>
> Hi Erik
>
> On 16/12/2021 14:30, Erik Cervin Edin wrote:
> > Steps to reproduce:
> > 1. git-rebase -i
> > 2. edit XYZ
> > 3. git-reset HEAD~
>
> "git reset" will update ORIG_HEAD to the current HEAD before resetting
> so here ORIG_HEAD gets updated to point to XYZ
>
> > 4. git-commit -C ORIG_HEAD -a
> > 5. git-rebase --continue
> > 6. git-show ORIG_HEAD
> >
> > Expected behavior:
> > ORIG_HEAD should point at the previous HEAD of the rebased branch
> >
> > Actual behavior:
> > ORIG_HEAD points to XYZ
> >
> > My understanding from reading https://stackoverflow.com/a/64949884 is
> > that this is incorrect behavior.
> >
> > Perhaps this is as intended but I would at least personally prefer
> > that ORIG_HEAD would point to the previous HEAD of the rebased branch.
>
> You can use the reflog to get the previous HEAD of the rebased branch
> after rebasing. Immediately after the rebase branch-name@{1} will point
> to the pre-rebase HEAD.
>
> Best Wishes
>
> Phillip
>
>
> > Seen in:
> > git version 2.31.1.windows.1
> >
> > Possibly related to
> > e100bea481 - rebase -i: stop overwriting ORIG_HEAD buffer
>
--
Erik Cervin-Edin
Erik.CervinEd.in
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: bug?: ORIG_HEAD incorrect after reset during git-rebase -i
2021-12-16 16:44 ` Erik Cervin Edin
@ 2023-01-05 0:11 ` Philippe Blain
2023-01-06 14:29 ` Phillip Wood
0 siblings, 1 reply; 7+ messages in thread
From: Philippe Blain @ 2023-01-05 0:11 UTC (permalink / raw)
To: Erik Cervin Edin, phillip.wood; +Cc: git
Hi Phillip and Erik,
Le 2021-12-16 à 11:44, Erik Cervin Edin a écrit :
> Hi Phillip,
>
> Yes, I know.
> It's just that I was under the impression ORIG_HEAD was to be reverted
> to .git/rebase-merge/orig-head at the finish of the rebase.
> Personally, it's the behavior I would expect.
>
> Thanks for the tips.
I just hit the same bug (I think it qualifies as one). In fact git-rebase(1) explicitely mentions
that ORIG_HEAD is set to the branch tip before the rebase starts:
$ git grep -C2 ORIG_HEAD Documentation/git-rebase.txt
Documentation/git-rebase.txt-36-The current branch is reset to `<upstream>` or `<newbase>` if the
Documentation/git-rebase.txt-37-`--onto` option was supplied. This has the exact same effect as
Documentation/git-rebase.txt:38:50:`git reset --hard <upstream>` (or `<newbase>`). `ORIG_HEAD` is set
Documentation/git-rebase.txt-39-to point at the tip of the branch before the reset.
Documentation/git-rebase.txt-40-
Here is my runnable reproducer. It is slightly more complicated than Erik's, since
I split the second commit in two, but this is not necessary to trigger the bug; just
running 'git reset HEAD^' as Erik wrote is enough.
```bash
#!/bin/bash
rm -rf repro
git init repro
(
cd repro
# Create 3 commits
cat << EOF >test
hello
every
one
EOF
git add test
git commit -m initial
cat << EOF >test
hello
add new lines
every
and also here
one
EOF
git commit -am second
cat << EOF >test
hello
add new lines
every
and also here
one
still more changes
EOF
git commit -am third
# Rebase to split the second commit
GIT_SEQUENCE_EDITOR="sed -ie '1 s/^p /e /'" git rebase -i HEAD~2
git reset HEAD^
cat << EOF >test
hello
add new lines
every
one
EOF
git ci -am "second 1/2"
cat <<EOF >test
hello
add new lines
every
and also here
one
EOF
git ci -am "second 2/2"
# Finish rebase and demonstrate bug
git rebase --continue
echo ---
echo "@{1} is :"
git log -1 @{1}
echo "ORIG_HEAD is :"
git log -1 ORIG_HEAD
)
```
Cheers,
Philippe.
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: bug?: ORIG_HEAD incorrect after reset during git-rebase -i
2023-01-05 0:11 ` Philippe Blain
@ 2023-01-06 14:29 ` Phillip Wood
2023-01-07 17:06 ` Philippe Blain
0 siblings, 1 reply; 7+ messages in thread
From: Phillip Wood @ 2023-01-06 14:29 UTC (permalink / raw)
To: Philippe Blain, Erik Cervin Edin; +Cc: git
Hi Philippe & Erik
On 05/01/2023 00:11, Philippe Blain wrote:
> Hi Phillip and Erik,
>
> Le 2021-12-16 à 11:44, Erik Cervin Edin a écrit :
>> Hi Phillip,
>>
>> Yes, I know.
>> It's just that I was under the impression ORIG_HEAD was to be reverted
>> to .git/rebase-merge/orig-head at the finish of the rebase.
>> Personally, it's the behavior I would expect.
>>
>> Thanks for the tips.
>
> I just hit the same bug (I think it qualifies as one). In fact git-rebase(1) explicitely mentions
> that ORIG_HEAD is set to the branch tip before the rebase starts:
Strictly speaking that is what we do so we're documentation the
implemented behavior. What's not clear from the documentation is that if
the user run 'git reset' while rebasing then ORIG_HEAD will be
overwritten. We could update ORIG_HEAD at the end of the rebase as you
suggested but I wouldn't be surprised if some else complains that
ORIG_HEAD no longer points to the commit that the reset while running
rebase. I also wonder if users would expect 'git rebase --continue' to
update ORIG_HEAD to point to the pre-rebase HEAD so it is consistent
each time rebase stops. Basically I think the situation is confusing and
I don't have a clear idea as to how to make it better. If someone
submits a patch to try and clean things up I'll happily look at it but
unless I'm hit by a bright idea as to how to fix it I probably wont work
on it myself.
Best Wishes
Phillip
> $ git grep -C2 ORIG_HEAD Documentation/git-rebase.txt
> Documentation/git-rebase.txt-36-The current branch is reset to `<upstream>` or `<newbase>` if the
> Documentation/git-rebase.txt-37-`--onto` option was supplied. This has the exact same effect as
> Documentation/git-rebase.txt:38:50:`git reset --hard <upstream>` (or `<newbase>`). `ORIG_HEAD` is set
> Documentation/git-rebase.txt-39-to point at the tip of the branch before the reset.
> Documentation/git-rebase.txt-40-
>
> Here is my runnable reproducer. It is slightly more complicated than Erik's, since
> I split the second commit in two, but this is not necessary to trigger the bug; just
> running 'git reset HEAD^' as Erik wrote is enough.
>
> ```bash
> #!/bin/bash
> rm -rf repro
> git init repro
> (
> cd repro
> # Create 3 commits
> cat << EOF >test
> hello
> every
> one
> EOF
> git add test
> git commit -m initial
> cat << EOF >test
> hello
>
> add new lines
>
> every
>
> and also here
>
> one
> EOF
> git commit -am second
> cat << EOF >test
> hello
>
> add new lines
>
> every
>
> and also here
>
> one
>
> still more changes
> EOF
> git commit -am third
> # Rebase to split the second commit
> GIT_SEQUENCE_EDITOR="sed -ie '1 s/^p /e /'" git rebase -i HEAD~2
> git reset HEAD^
> cat << EOF >test
> hello
>
> add new lines
>
> every
> one
> EOF
> git ci -am "second 1/2"
> cat <<EOF >test
> hello
>
> add new lines
>
> every
>
> and also here
>
> one
> EOF
> git ci -am "second 2/2"
> # Finish rebase and demonstrate bug
> git rebase --continue
> echo ---
> echo "@{1} is :"
> git log -1 @{1}
> echo "ORIG_HEAD is :"
> git log -1 ORIG_HEAD
>
> )
> ```
>
> Cheers,
>
> Philippe.
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: bug?: ORIG_HEAD incorrect after reset during git-rebase -i
2023-01-06 14:29 ` Phillip Wood
@ 2023-01-07 17:06 ` Philippe Blain
2023-01-07 19:50 ` Philippe Blain
0 siblings, 1 reply; 7+ messages in thread
From: Philippe Blain @ 2023-01-07 17:06 UTC (permalink / raw)
To: phillip.wood, Erik Cervin Edin; +Cc: git
Hi Phillip,
Le 2023-01-06 à 09:29, Phillip Wood a écrit :
> Hi Philippe & Erik
>
> On 05/01/2023 00:11, Philippe Blain wrote:
>> Hi Phillip and Erik,
>>
>> Le 2021-12-16 à 11:44, Erik Cervin Edin a écrit :
>>> Hi Phillip,
>>>
>>> Yes, I know.
>>> It's just that I was under the impression ORIG_HEAD was to be reverted
>>> to .git/rebase-merge/orig-head at the finish of the rebase.
>>> Personally, it's the behavior I would expect.
>>>
>>> Thanks for the tips.
>>
>> I just hit the same bug (I think it qualifies as one). In fact git-rebase(1) explicitely mentions
>> that ORIG_HEAD is set to the branch tip before the rebase starts:
>
> Strictly speaking that is what we do so we're documentation the
> implemented behavior. What's not clear from the documentation is that
> if the user run 'git reset' while rebasing then ORIG_HEAD will be
> overwritten.
Yes, I agree. I think we could highlight it in the doc.
> We could update ORIG_HEAD at the end of the rebase as
> you suggested but I wouldn't be surprised if some else complains that
> ORIG_HEAD no longer points to the commit that the reset while running
> rebase. I also wonder if users would expect 'git rebase --continue'
> to update ORIG_HEAD to point to the pre-rebase HEAD so it is
> consistent each time rebase stops. Basically I think the situation is
> confusing and I don't have a clear idea as to how to make it better.
> If someone submits a patch to try and clean things up I'll happily
> look at it but unless I'm hit by a bright idea as to how to fix it I
> probably wont work on it myself.
Thanks for your thoughts. I think you make good points, it's true that
some people might be relying on the current behaviour.
I'll try to send a few updates to the doc to make this hopefully clearer.
Cheers,
Philippe.
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2023-01-07 19:51 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-12-16 14:30 bug?: ORIG_HEAD incorrect after reset during git-rebase -i Erik Cervin Edin
2021-12-16 16:27 ` Phillip Wood
2021-12-16 16:44 ` Erik Cervin Edin
2023-01-05 0:11 ` Philippe Blain
2023-01-06 14:29 ` Phillip Wood
2023-01-07 17:06 ` Philippe Blain
2023-01-07 19:50 ` Philippe Blain
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