OK, I thought this was a simple git scenario, what am I missing?
I have a master
branch and a feature
branch. I do some work on master
, some on feature
, and then some more on master
. I end up with something like this (lexicographic order implies the order of commits):
A--B--C------F--G (master)
\
D--E (feature)
I have no problem to git push origin master
to keep the remote master
updated, nor with git push origin feature
(when on feature
) to maintain a remote backup for my feature
work. Up until now, we're good.
But now I want to rebase feature
on top of the F--G
commits on master, so I git checkout feature
and git rebase master
. Still good. Now we have:
A--B--C------F--G (master)
\
D'--E' (feature)
Problem: the moment I want to backup the new rebased feature
branched with git push origin feature
, the push is rejected since the tree has changed due to the rebasing. This can only be solved with git push --force origin feature
.
I hate using --force
without being sure I need it. So, do I need it? Does the rebasing necessarily imply that the next push
should be --force
ful?
This feature branch is not shared with any other devs, so I have no problem de facto with the force push, I'm not going to lose any data, the question is more conceptual.
--force
is not a monster it's a feature. You can use it when is required.
The problem is that git push
assumes that remote branch can be fast-forwarded to your local branch, that is that all the difference between local and remote branches is in local having some new commits at the end like that:
Z--X--R <- origin/some-branch (can be fast-forwarded to Y commit)
\
T--Y <- some-branch
When you perform git rebase
commits D and E are applied to new base and new commits are created. That means after rebase you have something like that:
A--B--C------F--G--D'--E' <- feature-branch
\
D--E <- origin/feature-branch
In that situation remote branch can't be fast-forwarded to local. Though, theoretically local branch can be merged into remote (obviously you don't need it in that case), but as git push
performs only fast-forward merges it throws and error.
And what --force
option does is just ignoring state of remote branch and setting it to the commit you're pushing into it. So git push --force origin feature-branch
simply overrides origin/feature-branch
with local feature-branch
.
In my opinion, rebasing feature branches on master
and force-pushing them back to remote repository is OK as long as you're the only one who works on that branch.
Instead of using -f
or --force
developers should use
--force-with-lease
Why? Because it checks the remote branch for changes which is absolutely a good idea. Let's imagine that James and Lisa are working on the same feature branch and Lisa has pushed a commit. James now rebases his local branch and is rejected when trying to push. Of course James thinks this is due to rebase and uses --force
and would rewrite all Lisa's changes. If James had used --force-with-lease
he would have received a warning that there are commits done by someone else. I don't see why anyone would use --force
instead of --force-with-lease
when pushing after a rebase.
--force-with-lease
addresses the concern of using --force
--force-with-lease --force-if-includes
. It's quite a bit safer than just ----force-with-lease
e.g. when an IDE is doing background fetches.
I would use instead "checkout -b" and it is easier to understand.
git checkout myFeature
git rebase master
git push origin --delete myFeature
git push origin myFeature
when you delete you prevent to push in an exiting branch that contains different SHA ID. I am deleting only the remote branch in this case.
push --force
, so is only a way to get around a git repo preventing --force
. As such, I don't think this is ever a good idea - either the repo permits push --force
, or for a good reason it disables it. Nabi's answer is more appropriate if --force
is disabled on the remote repo, as it doesn't have the risk of losing commits from other developers or otherwise causing problems.
git push --force
doesn't close Merge Request, unlike git push origin --delete
does.
One solution to this is to do what msysGit's rebasing merge script does - after the rebase, merge in the old head of feature
with -s ours
. You end up with the commit graph:
A--B--C------F--G (master)
\ \
\ D'--E' (feature)
\ /
\ --
\ /
D--E (old-feature)
... and your push of feature
will be a fast-forward.
In other words, you can do:
git checkout feature
git branch old-feature
git rebase master
git merge -s ours old-feature
git push origin feature
(Not tested, but I think that's right...)
git rebase
(instead of merging master
back into your feature branch) is making clean linear commits history. With your approach commits history gets even worse. And as rebasing creates new commits without any reference to their previous versions I'm not even sure that result of this merge will be adequate.
merge -s ours
is that it artificially adds a parent reference to the previous version. Sure, the history doesn't look clean, but the questioner seems to be particularly bothered by having to force the push of the feature
branch, and this gets around that. If you want to rebase, it's more-or-less one or the other. :) More generally, I think it's interesting that the msysgit project does this....
ours
strategy before but I thought it applies only to conflict situation by automatically resolving them using changes in our branch. It turned out it works differently. And working that way it's very useful if you need rebased version (e.g., for repo maintainer to apply it cleanly to master
) but want to avoid force pushing (if lots of other ppl for some reason are using your feature branch).
-X
arg.)
Other's have answered your question. If you rebase a branch you will need to force to push that branch.
Rebase and a shared repository generally do not get along. This is rewriting history. If others are using that branch or have branched from that branch then rebase will be quite unpleasant.
In general, rebase works well for local branch management. Remote branch management works best with explicit merges (--no-ff).
We also avoid merging master into a feature branch. Instead we rebase to master but with a new branch name (e.g adding a version suffix). This avoids the problem of rebasing in the shared repository.
It may or may not be the case that there is only one developer on this branch, that is now (after the rebase) not inline with the origin/feature.
As such I would suggest to use the following sequence:
git rebase master
git checkout -b feature_branch_2
git push origin feature_branch_2
Yeah, new branch, this should solve this without a --force, which I think generally is a major git drawback.
My way of avoiding the force push is to create a new branch and continuing work on that new branch and after some stability, remove the old branch that was rebased:
Rebasing the checked out branch locally
Branching from the rebased branch to a new branch
Pushing that branch as a new branch to remote. and deleting the old branch on remote
What is wrong with a git merge master
on the feature
branch? This will preserve the work you had, while keeping it separate from the mainline branch.
A--B--C------F--G
\ \
D--E------H
Edit: Ah sorry did not read your problem statement. You will need force as you performed a rebase
. All commands that modify the history will need the --force
argument. This is a failsafe to prevent you from losing work (the old D
and E
would be lost).
So you performed a git rebase
which made the tree look like (although partially hidden as D
and E
are no longer in a named branch):
A--B--C------F--G
\ \
D--E D'--E'
So, when trying to push your new feature
branch (with D'
and E'
in it), you would lose D
and E
.
For me following easy steps works:
1. git checkout myFeature
2. git rebase master
3. git push --force-with-lease
4. git branch -f master HEAD
5. git checkout master
6. git pull
After doing all above, we can delete myFeature branch as well by following command:
git push origin --delete myFeature
The following works for me:
git push -f origin branch_name
and it does not remove any of my code.
But, if you want to avoid this then you can do the following:
git checkout master
git pull --rebase
git checkout -b new_branch_name
then you can cherry-pick all your commits to the new branch. git cherry-pick COMMIT ID
and then push your new branch.
-f
is an alias for --force
, which is what the question is trying to avoid if possible.
Fetch new changes of master and rebase feature branch on top of latest master
git checkout master
git pull
git checkout feature
git pull --rebase origin master
git push origin feature
As the OP does understand the problem, just looks for a nicer solution...
How about this as a practice ?
Have on actual feature-develop branch (where you never rebase and force-push, so your fellow feature developers don't hate you). Here, regularly grab those changes from main with a merge. Messier history, yes, but life is easy and no one get's interupted in his work.
Have a second feature-develop branch, where one feature team member regulary pushes all feature commits to, indeed rebased, indeed forced. So almost cleanly based on a fairly recent master commit. Upon feature complete, push that branch on top of master.
There might be a pattern name for this method already.
I would do as below
rebase feature
git checkout -b feature2 origin/feature
git push -u origin feature2:feature2
Delete the old remote branch feature
git push -u origin feature:feature
Now the remote will have feature(rebased on latest master) and feature2(with old master head). This would allow you to compare later if you have done mistakes in reolving conflicts.
Success story sharing
git pull feature-branch
, this pull will generate a new merge commit (by merging remote and local versions of the feature branch). So either you get an unnecessary merge after rebasing, or you push with--force
.push --force
is not a problem) to keep commits history linear without any merge commits at all.--force-with-lease
as @hardev suggested is a great option