upstream - gitlab update fork




How do I update a GitHub forked repository? (11)

I recently forked a project and applied several fixes. I then created a pull request which was then accepted.

A few days later another change was made by another contributor. So my fork doesn't contain that change.

How can I get that change into my fork? Do I need to delete and re-create my fork when I have further changes to contribute? Or is there an update button?


Foreword: Your fork is the "origin" and the repository you forked from is the "upstream".

Let's assume that you cloned already your fork to your computer with a command like this:

git clone [email protected]:your_name/project_name.git
cd project_name

If that is given then you need to continue in this order:

  1. Add the "upstream" to your cloned repository ("origin"):

    git remote add upstream [email protected]:original_author/project_name.git
    
  2. Fetch the commits (and branches) from the "upstream":

    git fetch upstream
    
  3. Switch to the "master" branch of your fork ("origin"):

    git checkout master
    
  4. Stash the changes of your "master" branch:

    git stash
    
  5. Merge the changes from the "master" branch of the "upstream" into your the "master" branch of your "origin":

    git merge upstream/master
    
  6. Resolve merge conflicts if any and commit your merge

    git commit -am "Merged from upstream"
    
  7. Push the changes to your fork

    git push
    
  8. Get back your stashed changes (if any)

    git stash pop
    
  9. You're done! Congratulations!

GitHub also provides instructions for this topic: Syncing a fork


A lot of answers end up moving your fork one commit ahead of the parent repository. This answer summarizes the steps found here which will move your fork to the same commit as the parent.

  1. Change directory to your local repository.

    • Switch to master branch if you are not git checkout master
  2. Add the parent as a remote repository, git remote add upstream <repo-location>

  3. Issue git fetch upstream
  4. Issue git rebase upstream/master

    • At this stage you check that commits what will be merged by typing git status
  5. Issue git push origin master

For more information about these commands, refer to step 3.


Android Studio now has learned to work with GitHub fork repositories (you don't even have to add "upstream" remote repository by console command).

Open menu VCSGit

And pay attention to the two last popup menu items:

  • Rebase my GitHub fork

  • Create Pull Request

Try them. I use the first one to synchronize my local repository. Anyway the branches from the parent remote repository ("upstream") will be accessible in Android Studio after you click "Rebase my GitHub fork", and you will be able to operate with them easily.

(I use Android Studio 3.0 with "Git integration" and "GitHub" plugins.)


As a complement to this answer, I was looking for a way to update all remote branches of my cloned repo (origin) from upstream branches in one go. This is how I did it.

This assumes you have already configured an upstream remote pointing at the source repository (where origin was forked from) and have synced it with git fetch upstream.

Then run:

for branch in $(git ls-remote --heads upstream|sed 's#^.*refs/heads/##'); do git push origin refs/remotes/upstream/$branch:refs/heads/$branch; done

The first part of this command lists all heads in the upstream remote repo and removes the SHA-1 followed by refs/heads/ branch name prefix.

Then for each of these branches, it pushes the local copy of the upstream remote tracking branch (refs/remotes/upstream/<branch> on local side) directly to the remote branch on origin (refs/heads/<branch> on remote side).

Any of these branch sync commands may fail for one of two reasons: either the upstream branch have been rewritten, or you have pushed commits on that branch to your fork. In the first case where you haven't committed anything to the branch on your fork it is safe to push forcefully (Add the -f switch; i.e. git push -f in the command above). In the other case this is normal as your fork branch have diverged and you can't expect the sync command to work until your commits have been merged back into upstream.



Here is GitHub's official document on Syncing a fork:

Syncing a fork

The Setup

Before you can sync, you need to add a remote that points to the upstream repository. You may have done this when you originally forked.

Tip: Syncing your fork only updates your local copy of the repository; it does not update your repository on GitHub.

$ git remote -v
# List the current remotes
origin  https://github.com/user/repo.git (fetch)
origin  https://github.com/user/repo.git (push)

$ git remote add upstream https://github.com/otheruser/repo.git
# Set a new remote

$ git remote -v
# Verify new remote
origin    https://github.com/user/repo.git (fetch)
origin    https://github.com/user/repo.git (push)
upstream  https://github.com/otheruser/repo.git (fetch)
upstream  https://github.com/otheruser/repo.git (push)

Syncing

There are two steps required to sync your repository with the upstream: first you must fetch from the remote, then you must merge the desired branch into your local branch.

Fetching

Fetching from the remote repository will bring in its branches and their respective commits. These are stored in your local repository under special branches.

$ git fetch upstream
# Grab the upstream remote's branches
remote: Counting objects: 75, done.
remote: Compressing objects: 100% (53/53), done.
remote: Total 62 (delta 27), reused 44 (delta 9)
Unpacking objects: 100% (62/62), done.
From https://github.com/otheruser/repo
 * [new branch]      master     -> upstream/master

We now have the upstream's master branch stored in a local branch, upstream/master

$ git branch -va
# List all local and remote-tracking branches
* master                  a422352 My local commit
  remotes/origin/HEAD     -> origin/master
  remotes/origin/master   a422352 My local commit
  remotes/upstream/master 5fdff0f Some upstream commit

Merging

Now that we have fetched the upstream repository, we want to merge its changes into our local branch. This will bring that branch into sync with the upstream, without losing our local changes.

$ git checkout master
# Check out our local master branch
Switched to branch 'master'

$ git merge upstream/master
# Merge upstream's master into our own
Updating a422352..5fdff0f
Fast-forward
 README                    |    9 -------
 README.md                 |    7 ++++++
 2 files changed, 7 insertions(+), 9 deletions(-)
 delete mode 100644 README
 create mode 100644 README.md

If your local branch didn't have any unique commits, git will instead perform a "fast-forward":

$ git merge upstream/master
Updating 34e91da..16c56ad
Fast-forward
 README.md                 |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Tip: If you want to update your repository on GitHub, follow the instructions here


If you are using GitHub for Windows then now they have a one-click feature to update forks:

  1. Select the repository in the UI.
  2. Click "Update from user/branch" button the top.

If, like me, you never commit anything directly to master, which you should really, you can do the following.

From the local clone of your fork, create your upstream remote. You only need to do that once:

git remote add upstream https://github.com/whoever/whatever.git

Then whenever you want to catch up with the upstream repository master branch you need to:

git checkout master
git pull upstream master

Assuming you never committed anything on master yourself you should be done already. Now you can push your local master to your origin remote GitHub fork. You could also rebase your development branch on your now up-to-date local master.

So past the initial upstream setup and master checkout, all you need to do is run the following command to sync your master with upstream: git pull upstream master.


Since November 2013 there has been an unofficial feature request open with GitHub to ask them to add a very simple and intuitive method to keep a local fork in sync with upstream:

https://github.com/isaacs/github/issues/121

Note: Since the feature request is unofficial it is also advisable to contact [email protected] to add your support for a feature like this to be implemented. The unofficial feature request above could be used as evidence of the amount of interest in this being implemented.


Starting in May 2014, it is possible to update a fork directly from GitHub. This still works as of September 2017, BUT it will lead to a dirty commit history.

  1. Open your fork on GitHub.
  2. Click on Pull Requests.
  3. Click on New Pull Request. By default, GitHub will compare the original with your fork, and there shouldn't be anything to compare if you didn't make any changes.
  4. Click switching the base if you see that link. Otherwise, manually set the base fork drop down to your fork, and the head fork to the upstream. Now GitHub will compare your fork with the original, and you should see all the latest changes.
  5. Create pull request and assign a predictable name to your pull request (e.g., Update from original).
  6. Scroll down to Merge pull request, but don't click anything yet.

Now you have three options, but each will lead to a less-than-clean commit history.

  1. The default will create an ugly merge commit.
  2. If you click the dropdown and choose "Squash and merge", all intervening commits will be squashed into one. This is most often something you don't want.
  3. If you click Rebase and merge, all commits will be made "with" you, the original PRs will link to your PR, and GitHub will display This branch is X commits ahead, Y commits behind <original fork>.

So yes, you can keep your repo updated with its upstream using the GitHub web UI, but doing so will sully your commit history. Stick to the command line instead - it's easy.


When you have cloned your forked repository, go to the directory path where your clone resides and the few lines in your Git Bash Terminal.

$ cd project-name

$ git remote add upstream https://github.com/user-name/project-name.git
 # Adding the upstream -> the main repo with which you wanna sync

$ git remote -v # you will see the upstream here 

$ git checkout master # see if you are already on master branch

$ git fetch upstream

And there you are good to go. All updated changes in the main repository will be pushed into your fork repository.

The "fetch" command is indispensable for staying up-to-date in a project: only when performing a "git fetch" will you be informed about the changes your colleagues pushed to the remote server.

You can still visit here for further queries





github