Git Fork한 저장소를 original 저장소로 동기화 시키기

※ 선행사항 (되어있으면 상관없음)

Fork한 저장소에 original 저장소 세팅하기

git remote -v로 현재 등록된 저장소 확인

$ git remote -v
> origin  https://github.com/YOUR_USERNAME/YOUR_FORK.git (fetch)
> origin  https://github.com/YOUR_USERNAME/YOUR_FORK.git (push)

원래 original 저장소 추가

git remote add upstream https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY.git

아래처럼 다시 git remote -v 로 저장소 확인

$ git remote -v
> origin    https://github.com/YOUR_USERNAME/YOUR_FORK.git (fetch)
> origin    https://github.com/YOUR_USERNAME/YOUR_FORK.git (push)
> upstream  https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY.git (fetch)
> upstream  https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY.git (push)

Fork한 저장소를 원래 original 저장소로 동기화 시키기

git fetch upstream 으로 원래 저장소를 fetch

$ git fetch upstream
> 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/ORIGINAL_OWNER/ORIGINAL_REPOSITORY
>  * [new branch]      master     -> upstream/master

다시 master로 돌아가기

$ git checkout master
> Switched to branch 'master'

master에서 upstream merge하기

$ git merge upstream/master
> 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

References

https://help.github.com/en/github/collaborating-with-issues-and-pull-requests/syncing-a-fork
https://help.github.com/en/github/collaborating-with-issues-and-pull-requests/configuring-a-remote-for-a-fork