How I can remove an already merged branch and preserve date

Question

Suppose following git history with mainline A and already merged branch B.

                  b1     b2
             -----•------•---            B
            /                \
   •------•----•--------------•-------•  A
   a1     a2   a3             a4      a5

a4 is a merge commit w/ commit message merge "merge B into A.

Is it possible to to change the history into following.

                    b1'  b2'
   •-----•-----•-----•-----•-----•  A
   a1     a2   a3                a5

edit: I don't want to change the commit date if possible.

Not without also rewriting `a5` into a new and different commit. — poke, Apr 27 '18 at 07:51
@Daniel1147 afaik cherry pick does not alter the commit whom picked from — brandstifter, Apr 27 '18 at 07:59
Possible duplicate of [Linearize git history, preserving all commits](https://stackoverflow.com/questions/49317019/linearize-git-history-preserving-all-commits) — Robin Green, Apr 27 '18 at 07:59
`git rebase a2 A` is better. `git rebase a2` works if you are already on branch A. a3, b1, b2 and a5 will be rewritten and a4 will be flattened. — ElpieKay, Apr 27 '18 at 08:05
@RobinGreen my question differ in preserving the commit date as mentioned in the question — brandstifter, Apr 27 '18 at 08:15
You can pass the `--committer-date-is-author-date` option when you run `git rebase` to achieve that. — Robin Green, Apr 27 '18 at 08:19
@RobinGreen --committer-date-is-author-date does not work. the commits always get a the date of the rebase. — brandstifter, Apr 27 '18 at 09:37
Yes, in some cases it does not work. See https://stackoverflow.com/questions/46395528/git-rebase-committer-date-is-author-date-root-does-not-work for more details. — Robin Green, Apr 27 '18 at 09:39

robertbeb · Accepted Answer · 2018-04-27T13:02:51.227

1

git cherry-pick saves commit's date

1) go to commit a2 git checkout a2
2) create new branch C git branch C
3) go to new branch C git checkout C
4) fetch from A branch git cherry-pick a3 b1 b2 a5
5) go back to A git checkout A
6) remove permanently everything newer than commit a2 git reset --hard a2
7) fetch from branch C git cherry-pick a3 b1 b2 a5
8) And good to remove branch C, remove branch C git branch -D C

edited Apr 27 '18 at 13:02

answered Apr 27 '18 at 11:17

robertbeb

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Thanks for the hint it don't solve the commit date problem for a5 and a3 – brandstifter Apr 27 '18 at 15:24
It is not suitable for large repositories – brandstifter Apr 27 '18 at 15:40
What date in a5 and a3 do You expect? (Steps in my solution saves dates in same sequence as in your picture a1 a2 a3 b1 b2 a5) – robertbeb Apr 27 '18 at 19:27

How I can remove an already merged branch and preserve date

1 Answers1