转《同步一个 fork》

原文：http://gaohaoyang.github.io/2015/04/12/Syncing-a-fork/

搜索 fork sync，就可以看到 GitHub 自己的帮助文档 Syncing a fork 点进去看这篇的时候，注意到有一个 Tip: Before you can sync your fork with an upstream repository, you must configure a remote that points to the upstream repository in Git.
根据这两篇文章，问题迎刃而解！

具体方法

• Configuring a remote for a fork

• 给 fork 配置一个 remote

• 主要使用 git remote -v 查看远程状态。

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

• 添加一个将被同步给 fork 远程的上游仓库

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

• 再次查看状态确认是否配置成功。

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)

• Syncing a fork

• 从上游仓库 fetch 分支和提交点，传送到本地，并会被存储在一个本地分支

upstream/master 
git fetch upstream
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

• 切换到本地主分支(如果不在的话)

git checkout master
git checkout master
# Switched to branch 'master'

• 把 upstream/master 分支合并到本地 master 上，这样就完成了同步，并且不会丢掉本地修改的内容。

git merge upstream/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

• 如果想更新到 GitHub 的 fork 上，直接 git push origin master 就好了。

1. https://help.github.com/articles/syncing-a-fork/

2. http://www.cnblogs.com/rubylouvre/archive/2013/01/24/2874694.html

3. http://www.miss77.net/549.html

4. http://blog.csdn.net/bluecloudmatrix/article/details/41176373