How to change initial commit of branch after filter-branch

Question

After a filter-branch on master (to add sign-off), I have this :

A-B-C-D-E-F (master)

A'-X-Y-Z (branch xxx)

where A' is the old initial commit. I want to "reconnect" my branch "xxx" to master, to initial commit A to have something like this :

A-B-C-D-E-F (master)
 \
  X-Y-Z (branch xxx)

How to do that ? Thanks

`A'` is the old first commit, but after applying `filter-branch` on all `master`, `A` has changed, so that the branch `xxx` is no more starting from `A` — xnopre, Feb 22 '19 at 10:29

Romain Valeri · Accepted Answer · 2019-02-22T15:15:17.420

1

3-steps solution with backup option included :

# create a backup for the branch
git checkout -b backup-xxx xxx

# force position of branch xxx at A
git branch -f xxx A

# get the commits you wanted from the backup branch
git checkout xxx
git cherry-pick X Y Z

You'll have backup-xxx in the state xxx was before the operations, just in case you regret your move later.

Backup plan :

# to restore branch xxx in its previous state
git branch -f xxx backup-xxx

edited Feb 22 '19 at 15:15

answered Feb 22 '19 at 08:47

Romain Valeri

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Thanks ! Just a change, before doing `git cherry-pick`, I had to `checkout` (back) to xxx. And after, I have done `push -f` to update remote branch. Great ! Thanks ! – xnopre Feb 22 '19 at 14:25
1

@xnopre Hey you're right! I forgot to change back to your branch. Good point, I've edited. – Romain Valeri Feb 22 '19 at 15:15
Or else we could have done `git checkout -B xxx A` at second step and not have to checkout back to `xxx`. Just a thought – Romain Valeri Feb 22 '19 at 15:17
You have to be on `xxx` to do `cherry-pick` – xnopre Feb 25 '19 at 09:49

score 1 · Answer 2 · answered Feb 22 '19 at 10:57

1

You can follow the steps.

git checkout master
git checkout <SHA-HASH-OF-A-AFTER-FILTER-BRANCH> #Now your head should be in detached state at commit-hash of A
git checkout -b <NewConnectedBranch> #B is created from A commit
git cherry-pick X..Z #Applying changes from the disconnected branch

answered Feb 22 '19 at 10:57

Mohamed Anees A

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How is this affecting branch `xxx`? – Romain Valeri Feb 22 '19 at 11:00
If this works, he can delete xxx and and rename the "NewConnectedBranch" to xxx or he can continue – Mohamed Anees A Feb 22 '19 at 11:03
Also, I agree it does not reconnect. It simply involves creating another connected branch. Would solve his issue anyway. – Mohamed Anees A Feb 22 '19 at 11:04

How to change initial commit of branch after filter-branch

2 Answers2