Re: Cleaning up history with git rebase

From: Michael Witten <mfwitten@gmail.com>
Date: Aug 4, 2011, 12:15 UTC
Message-ID: <d62225a3cc5740cda7cb163a94d55892-mfwitten@gmail.com>
In-Reply-To: <1b66c8efe0214915be2c52a5aacd22de-mfwitten@gmail.com>

On Mon, 01 Aug 2011 01:07:33 -0000, Michael Witten wrote:

Show 79 quoted lines

> Michael Witten wrote:
>
>> On Sun, 31 Jul 2011 18:44:43 -0300, Ricky, Egeland wrote:
>>
>>> On Jul 31, 2011, at 6:33 PM, Michael Witten wrote:
>>> 
>>>> On Sun, Jul 31, 2011 at 20:21, Michael Witten <mfwitten@gmail.com> wrote:
>>>>> Why are there conflicts anyway?
>>>>
>>>> Oh...
>>>>
>>>> I guess there were conflicts when the merge commit was made in
>>>> the original repository, and these conflicts were resolved by
>>>> the merge commit itself. Hence, when rebase tries to split up
>>>> a merge by dealing with just the non-merge parents, you end up
>>>> having to deal with the conflict again.
>>> 
>>> Yes, I thought it was something like this going on, too. In the
>>> pre-rebase history, when there is a commit with "Conflict:" and
>>> listing file which is in the sub-repository history, this is a
>>> point where rebase stops with a conflict.
>>> 
>>>> Shouldn't rebase take this into account?
>>> 
>>> Not sure.  Seems that it does not, it makes me resolve the conflict =
>>> again.
>>
>> I think git rebase should take this into account is what I'm saying.
>>
>> The following implements what I think `git rebase' should be doing;
>> run it instead of `git rebase' in your repo:
>>
>>   git branch saved
>>   git rev-list HEAD --reverse --first-parent --parents |
>>   {
>>     read root
>>     git reset --hard $root
>>     rebase_head=$root
>>
>>     while read commit first_parent other_parents; do
>>
>>       if [ -z "$other_parents" ]; then
>>
>>         git cherry-pick $commit
>>         rebase_head=$commit
>>
>>       else
>>
>>         for parent in $other_parents; do
>>
>>           if ! git cherry-pick $parent; then
>>
>>             git reset --hard $rebase_head
>>             git merge $other_parents
>>             git rm -rf .
>>             git checkout -- $commit
>>             git commit -aC $commit 
>>             break
>>
>>           fi
>>
>>         done
>>
>>         rebase_head=$(git rev-parse HEAD)
>>
>>       fi
>>
>>     done
>>   }
>
> Woops!
>
> This line:
>
>   git checkout -- $commit
>
> should be:
>
>   git checkout $commit -- .

I noticed that my script has another problem; the line:

  rebase_head=$commit

should be:

  rebase_head=$(git rev-parse HEAD)

I was trying to make an optimization, but it's the wrong logic :-/

Sorry for the confusion. Here is an updated version of the entire script:

  git branch saved
  git rev-list HEAD --reverse --first-parent --parents |
  {
    read root
    git reset --hard $root
    rebase_head=$root

    while read commit first_parent other_parents; do

      if [ -z "$other_parents" ]; then

        git cherry-pick $commit

      else

        for parent in $other_parents; do

          if ! git cherry-pick $parent; then

            git reset --hard $rebase_head
            git merge $other_parents
            git rm -rf .
            git checkout $commit -- .
            git commit -aC $commit
            break

fi

        done

fi

      rebase_head=$(git rev-parse HEAD)

    done
  }