git - GitHub keeps saying "This branch is X commits ahead, Y commits behind"

Question

I know there are several similar questions, but I think my situation is a little bit different.

Let's say there is a GitHub repository which I want to contribute to. I fork that repository into my GitHub account and I clone the fork from my account in my PC. Fine.

Before working on an issue, I first want to synchronize my fork with the 'original' repository. I go to my account fork, click on New Pull request, make sure that I select mine as base and the original master as head fork, I see the differences (all the commits that people did in the original repository that are not on mine). Then I create the pull request on my fork and I merge those changes in my fork. I go to my local repo and do a git pull, and I have everything synchronized. Fine.

The problem comes now, in my GitHub account now it's always saying 'This branch is X commits ahead', where 'X' is the number of times that I did the synchronize process I described above. So, every time I do a pull request into the original repository (not my fork), is showing that I'm committing my code plus X more commits, that are the merges I did on my fork to synchronize with the original repository.

Of course, I don't want to push those changes into the original repository, since they already have those changes in place, so I don't understand why GitHub keeps saying to me that I have changes to commit.

I think it's something that has to be solved on my GitHub account, because in my local repository there are no changes or issues, actually I even removed it and re-cloned again.

Do you have any ideas?

Answer 1

As you guessed, these extra commits are likely the merge commits from the Pull Requests that you created.

In the future, there's a much easier way to sync your fork with the original repository. In your local repo, after the initial clone do:

git remote add upstream https://github.com/upstream/repo.git

Then, whenever you want to sync the changes from upstream, do:

git pull --rebase upstream master
git push --force-with-lease origin master

(The --rebase and --force-with-lease options will only be necessary if you have commits that haven't been merged into the upstream repo.)

_{Obligatory warning: Since a rebase rewrites history, this can be dangerous / disruptive for anyone else working on this branch. Be sure you clearly communicate what you have done with anyone you are collaborating with. Since this is a personal fork, I assume this won't be an issue for you.}

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Now to fix your current issue after the fact.

1. Add the upstream remote as described above.

2. Reset your local branch to match upstream:

   git checkout master
   git reset --hard upstream/master
   

3. If you have created any commits in your fork, you can cherry-pick them onto your updated version of master. If you can't remember or need help finding them, something like

   git log --oneline master origin/master
   

   should show you any commits not in upstream.

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Above I assumed that you are only using one branch, master. If you aren't already, I highly recommend that you create a new branch for each feature / bug fix that you work on. Among other benefits, this allows you to start work on another feature / bug fix when you are still waiting for an earlier PR to be merged. If you never commit directly to master, then you can sync without the --rebase or --force-with-lease:

git checkout master
git pull upstream master
git push origin master

To update a feature branch after you have updated master, do:

git checkout myfeature
git rebase master
git push --force-with-lease origin myfeature # if you have already pushed