一、背景介绍?：
某天组长帮你做Code Review，说你代码里多余的空格行可以删除了，并且添加个log，方便测试。Easy! 你说好的，喝了口水，然后上了个厕所，回来后删了空格，commit & push，然后意识到你没有添加log，然后继续在同一个branch上添加log，然后commit & push。
这时，你发现这是组长交代的一件事，不应该用两个commit来实现，为了掩盖自己犯下的这个“蠢事”，你就想着把这两个提交合并为一个。（如下图所示，目的：将同一个分支上的change 1提交和chang 2提交合并为一个提交）

第一个提交:change 1 第二个提交:change 2
二、OK，进入git command实际操作：

1. 命令行输入：git rebase -i HEAD~2 （i的意思是：interactive，HEAD_{2为在历史的前两个提交，同理，HEAD}4就是历史的前四个提交。）

git rebase -i HEAD~2

2. vim出现如下所以文件信息，前面两行就是你的提交信息，比如第一行分别对应为：pick(使用提交)、56a06ef(提交的ID)、change 1: remove one blank line(提交的描述信息)

  1 pick 56a06ef change 1: remove one blank line
  2 pick edbeab5 change 2: add log on MainActivity
  3 
  4 # Rebase 23198ba..edbeab5 onto 23198ba (2 commands)
  5 #
  6 # Commands:
  7 # p, pick <commit> = use commit
  8 # r, reword <commit> = use commit, but edit the commit message
  9 # e, edit <commit> = use commit, but stop for amending
 10 # s, squash <commit> = use commit, but meld into previous commit
 11 # f, fixup <commit> = like "squash", but discard this commit's log message
 12 # x, exec <command> = run command (the rest of the line) using shell
 13 # b, break = stop here (continue rebase later with 'git rebase --continue')
 14 # d, drop <commit> = remove commit
 15 # l, label <label> = label current HEAD with a name
 16 # t, reset <label> = reset HEAD to a label
 17 # m, merge [-C <commit> | -c <commit>] <label> [# <oneline>]
 18 # .       create a merge commit using the original merge commit's
 19 # .       message (or the oneline, if no original merge commit was
 20 # .       specified). Use -c <commit> to reword the commit message.
 21 #
 22 # These lines can be re-ordered; they are executed from top to bottom.
 23 #
 24 # If you remove a line here THAT COMMIT WILL BE LOST.
 25 #
 26 # However, if you remove everything, the rebase will be aborted.
 27 #
 28 # Note that empty commits are commented out

3. 将第二行的pick改成s, 也就是squash(挤压合并)，作用是：使用提交，将此提交与之前的提交合并。 然后保存文件退出vim。

  1 pick 56a06ef change 1: remove one blank line
  2 s edbeab5 change 2: add log on MainActivity
  3 
  4 # Rebase 23198ba..edbeab5 onto 23198ba (2 commands)
  5 #
  6 # Commands:
  7 # p, pick <commit> = use commit
  8 # r, reword <commit> = use commit, but edit the commit message
  9 # e, edit <commit> = use commit, but stop for amending
 10 # s, squash <commit> = use commit, but meld into previous commit
 11 # f, fixup <commit> = like "squash", but discard this commit's log message
 12 # x, exec <command> = run command (the rest of the line) using shell
 13 # b, break = stop here (continue rebase later with 'git rebase --continue')
 14 # d, drop <commit> = remove commit
 15 # l, label <label> = label current HEAD with a name
 16 # t, reset <label> = reset HEAD to a label
 17 # m, merge [-C <commit> | -c <commit>] <label> [# <oneline>]
 18 # .       create a merge commit using the original merge commit's
 19 # .       message (or the oneline, if no original merge commit was
 20 # .       specified). Use -c <commit> to reword the commit message.
 21 #
 22 # These lines can be re-ordered; they are executed from top to bottom.
 23 #
 24 # If you remove a line here THAT COMMIT WILL BE LOST.
 25 #
 26 # However, if you remove everything, the rebase will be aborted.
 27 #
 28 # Note that empty commits are commented out

4. 提交你的代码，git commit -a, vim出现如下所以文件信息：注意看：第4行和第8行分别对应这你第一次和第二次的提交描述信息，这时你就要将这两条描述信息合并为一条。

  1 # This is a combination of 2 commits.
  2 # This is the 1st commit message:
  3 
  4 change 1: remove one blank line
  5 
  6 # This is the commit message #2:
  7 
  8 change 2: add log on MainActivity
  9 
 10 # Please enter the commit message for your changes. Lines starting
 11 # with '#' will be ignored, and an empty message aborts the commit.
 12 #
 13 # Date:      Fri Apr 26 16:25:23 2019 +0800
 14 #
 15 # interactive rebase in progress; onto 23198ba
 16 # Last commands done (2 commands done):
 17 #    pick 56a06ef change 1: remove one blank line
 18 #    squash edbeab5 change 2: add log on MainActivity
 19 # No commands remaining.
 20 # You are currently rebasing branch 'master' on '23198ba'.
 21 #
 22 # Changes to be committed:
 23 #       modified:   app/src/main/java/com/example/jere/retrofit/MainActivity.java
 24 #

5. 将之前的两条提交描述信息，修改合并为一条，然后保存退出vim，如下所示：

  1 # This is a combination of 2 commits.
  2 # This is the 1st commit message:
  3 
  4 change 1: remove one blank line && change 2: add log on MainActivity
  5 
  6 # Please enter the commit message for your changes. Lines starting
  7 # with '#' will be ignored, and an empty message aborts the commit.
  8 #
  9 # Date:      Fri Apr 26 16:25:23 2019 +0800
 10 #
 11 # interactive rebase in progress; onto 23198ba
 12 # Last commands done (2 commands done):
 13 #    pick 56a06ef change 1: remove one blank line
 14 #    squash edbeab5 change 2: add log on MainActivity
 15 # No commands remaining.
 16 # You are currently rebasing branch 'master' on '23198ba'.
 17 #
 18 # Changes to be committed:
 19 #       modified:   app/src/main/java/com/example/jere/retrofit/MainActivity.java
 20 #

6. 保存退出后，push代码：git push origin master -f (注意：因为时rebase操作，所以要加-f, 强制push), 推送完成， 如下所以，完成将两个提交合并为一个。

   
   

成功将change 1和change 2两个提交合并为一个
三、整理branch上的commit的必要性
之前我一直觉得一个commit提交就是做一件事情，我是在同一个branch上提交的，最后我merge到master或相应的branch上时都是会有这些提交记录的，所以我也一直都不会去整理我的commit提交。所以正因为如此，我的branch上常常会存在这样的提交，比如：提交1‘finish login feature’，紧接着后面就是提交2‘code review for login feature’。这样的操作其实很正常，我们都是在做好功能后，然后再去做code review，但其实我们完全可以将这两个提交合并成一个提交，方便自己以及同事查看你的代码。

概括：整理你的commit提交是一个很好的习惯，对团队合作开发百利无一害，而且整理的过程也是自己对开发这个功能的回顾思考，So，整理起来吧！

原文链接：https://blog.csdn.net/jerechen/article/details/89556281