github上fork过来的项目，如何与原仓库保持同步

重点在于：除了origin以外，增加一个upstream，来跟踪原仓库更新

配置upstream指向fork的原仓库

打开终端，进入到本地仓库：
1 查看现有的远程仓库：

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

2 添加指向原仓库的upstream

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

3 查看origin和upstream

$ 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)

获取原仓库的更新并同步

在本地仓库：
1 获取原仓库的更新到本地

$ 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

2 切换到本地仓库的某一分支（如master）

$ git checkout master
Switched to branch 'master'

3 合并原仓库的更新到本地（如将upstream/master的更新合并到本地master）

$ 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

可参考GithubHelp的 Configuring a remote for a fork 和 Syncing a fork