背景

以前一直觉得只要pull和push就够了，但合作中总会遇到各种非理想的情况。这时候才发现git其他命令的作用。

现在的情况是，repo是一个远程team维护的，我们需要增加新feature，那么就是一个feature分支了。由于开发中各种修改，本feature分支多次commit。最后，交给远程team review的时候，人家看着乱七八糟的修改历史很蛋疼：很难看懂各种增量修改。其实，对人家来说，我们的改动应该就是增加或者删除。给他们看开发过程的增量反而太乱。于是，人家要求我们将feature分支的提交合并，这样看起来清爽。

一些简单的命令准备

合并分支的命令是rebase，除此之外，其他的一些命令也应该知晓。

查看commit历史

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git log

查看当前状态

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git status

添加所有文件

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git add .

提交修改

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git commit -m "本次提交添加了xxxx"

vim的简单指令：

参阅vim的简单使用

准备一个测试repo

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git init test-rebase
cd test-rebase

提交一个文件多次：

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vim test.txt
//输入第一次提交。   

git add test.txt
git commit -m "1"

vim test.txt
//输入第2次提交。   

git add test.txt
git commit -m "2"

vim test.txt
//输入第3次提交。   

git add test.txt
git commit -m "3"

查看log:

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git log

//////
commit 0353373749d72e53a34c7bdda86d77d7bb3ca6fe
Author: ryan <v-rmiao@expedia.com>
Date:   Wed Jul 19 13:23:18 2017 +0800

    3

commit acf6d24adc2097fda82d29064e8edfef6355d01d
Author: ryan <v-rmiao@expedia.com>
Date:   Wed Jul 19 13:20:37 2017 +0800

    2

commit 2169bc5e20386951b19aff32143e74f2da683df2
Author: ryan <v-rmiao@expedia.com>
Date:   Wed Jul 19 13:19:42 2017 +0800

    1

可以看到有三次提交了。现在我们想要把第2次和第3次提交的内容合并成一次提交。

开始rebase

1. 复制合并前的一次提交的hash

这里就是第一次提交的hash。即2169bc5e2

2. git rebase -i xxx

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git rebase -i 2169bc5e2

进入历史提交的编辑页面，此时编辑方式为vim。

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pick acf6d24 2
pick 0353373 3

# Rebase 2169bc5..0353373 onto 2169bc5 (2 commands)
#
# Commands:
# p, pick = use commit
# r, reword = use commit, but edit the commit message
# e, edit = use commit, but stop for amending
# s, squash = use commit, but meld into previous commit
# f, fixup = like "squash", but discard this commit's log message
# x, exec = run command (the rest of the line) using shell
# d, drop = remove commit
#
# These lines can be re-ordered; they are executed from top to bottom.
#
# If you remove a line here THAT COMMIT WILL BE LOST.
#
# However, if you remove everything, the rebase will be aborted.
#
# Note that empty commits are commented out

可以看到第2次和第3次的提交消息，并且是从old->new来排序的。我们需要把第3次提交合并到第2次上。使用squash.

squash

修改第三次提交为squash，意思是和前一次(第二次)提交合并。
键盘按键j移动到第二行，然后按a开始编辑，删除pick，插入squash
如下：

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pick acf6d24 2
squash  0353373 3

# Rebase 2169bc5..0353373 onto 2169bc5 (2 commands)
#
# Commands:
# p, pick = use commit
# r, reword = use commit, but edit the commit message
# e, edit = use commit, but stop for amending
# s, squash = use commit, but meld into previous commit
# f, fixup = like "squash", but discard this commit's log message
# x, exec = run command (the rest of the line) using shell
# d, drop = remove commit
#
# These lines can be re-ordered; they are executed from top to bottom.
#
# If you remove a line here THAT COMMIT WILL BE LOST.
#
# However, if you remove everything, the rebase will be aborted.
#
# Note that empty commits are commented out

然后，按esc退出编辑，再按:,输入wq保存。
这时候会进入第二个vim页面，这里让我们再次修改commit message的。就是合并后的message。

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# This is a combination of 2 commits.
这是合并后的message，以下是之前合并的历史
# This is the 1st commit message:

2

# This is the commit message #2:

3

# Please enter the commit message for your changes. Lines starting
# with '#' will be ignored, and an empty message aborts the commit.
#
# Date:      Wed Jul 19 13:20:37 2017 +0800
#
# interactive rebase in progress; onto 2169bc5
# Last commands done (2 commands done):
#    pick acf6d24 2
#    squash 0353373 3
# No commands remaining.
# You are currently editing a commit while rebasing branch 'master' on '2169bc5'.
#
# Changes to be committed:

还是和刚才一样，按o插入下一行，输入这次合并的message。然后按esc，按:， 输入wq保存并退出。

完事，再次查看log

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git log

内容如下：

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commit 8f54e6b5643ff26ac967a9e6e6cded68a6c50906
Author: ryan <v-rmiao@expedia.com>
Date:   Wed Jul 19 13:20:37 2017 +0800

    这是合并后的message，以下是之前合并的历史

    2

    3

commit 2169bc5e20386951b19aff32143e74f2da683df2
Author: ryan <v-rmiao@expedia.com>
Date:   Wed Jul 19 13:19:42 2017 +0800

    1

参考

https://git-scm.com/book/zh/v2/Git-%E5%B7%A5%E5%85%B7-%E9%87%8D%E5%86%99%E5%8E%86%E5%8F%B2
https://github.com/geeeeeeeeek/git-recipes/wiki/2.7-%E9%87%8D%E5%86%99%E9%A1%B9%E7%9B%AE%E5%8E%86%E5%8F%B2