How to move a branch backwards in git?
GitGithubGit Problem Overview
The title is not very clear. What I actually need to do often is the following:
Let's say I have a development going on with several commits c1,c2,... and 3 branches A,B,C
c1--c2--c3--(B)--c4--(A,C)
Branch A and C are at the same commit.
Now I want branch A to go back where B is, so that it looks like this:
c1--c2--c3--(A,B)--c4--(C)
Important is that this has to happen locally and on GitHub.
Git Solutions
Solution 1 - Git
Use the reset subcommand:
git checkout A
git reset --hard B
git push --force github
As a sidenote, you should be careful when using git reset while a branch has been pushed elsewhere already. This may cause trouble to those who have already checked out your changes.
Solution 2 - Git
If there are no commits on branch A, then the git reset --hard B solution given by Bram Schoenmakers will work.
However if there are commits are branch A which must be preserved, then the following should do the trick:
- Make a backup copy of your repo (just in case)
git checkout Agit rebase -i --onto B SHA1-A^
...where SHA1-A^ is the commit id of the parent of your branch A
See the git rebase man page for details.
NOTE: This will rewrite history (as rebase always does). Special consideration should be made if your A branch was ever pushed to a public repo.
Solution 3 - Git
I usually use this sequence and find it the simplest way:
git checkout B
git branch -f A B
Solution 4 - Git
Delete the branch both locally and remotely, recreate the branch, push the branch back up to the server.
git branch -d A
git push origin :heads/A
git branch B A
git push origin A:A
Alternately you can use the following command to undo that last commit.
git revert c4
Which will make your timeline look like:
c1--c2--c3--(B)
\
c4--(C)
\
(^c4)--(A)
where (^c4) is a commit that undoes c4
I don't recommend using rebase or revert on a branch that has been pushed to a remote repo, they can cause tons of trouble for you or anyone else using that repo.