Git简单操作之分支管理（二）

心已赠人 2022-02-23 09:12 211阅读 0赞

##### 解决冲突 #####

--------------------

创建一个新的分支`feature1`分支：

$ git checkout -b feature1
    Switched to a new branch 'feature1'

修改`readme.txt`最后一行为：

$ vi readme.txt
    Creating a new branch is quick AND simple.

在`feature1`分支上提交：

$ git add readme.txt
    $ git commit -m 'AND simple'
    [feature1 3e4afc5] AND simple
     1 file changed, 1 insertion(+), 1 deletion(-)

切换到`master`分支：

$ git checkout master
    Switched to branch 'master'
    Your branch is ahead of 'origin/master' by 1 commit.
      (use "git push" to publish your local commits)

Git还会自动提示我们本地的`master`分支有`1`个`commit`没有`push`到远程`master`分支上，提示我们使用`git push`进行推送。  
在`master`分支上把`readme.txt`文件的最后改为：

Creating a new branch is quick & simple.

提交：

$ git add readme.txt
    $ git commit -m "& simple"
    [master f2ab727] & simple
     1 file changed, 1 insertion(+), 1 deletion(-)

现在`master`和`feature1`各自都分别有新的提交，这种情况下，Git无法执行“快速合并”，，只能试图将各自的修改合并起来，但这种合并可能就有冲突：

$ git merge feature1
    Auto-merging readme.txt
    CONFLICT (content): Merge conflict in readme.txt
    Automatic merge failed; fix conflicts and then commit the result.

Git告诉我们，`readme.txt`存在冲突，必须手动解决冲突后再提交。`git status`也可以告诉我们冲突的文件：

$ git status
    On branch master
    Your branch is ahead of 'origin/master' by 2 commits.
      (use "git push" to publish your local commits)
    
    You have unmerged paths.
      (fix conflicts and run "git commit")
      (use "git merge --abort" to abort the merge)
    
    Unmerged paths:
      (use "git add <file>..." to mark resolution)
    
            both modified:   readme.txt
    
    no changes added to commit (use "git add" and/or "git commit -a")

我们可以直接查看`readme.txt`的内容：

$ cat readme.txt
    Git is a distributed version control system.
    Git is free software distributed under the GPL.
    Git has a mutable index called stage.
    <<<<<<< HEAD
    Creating a new branch is quick & simple.
    =======
    Creating a new branch is quick AND simple.
    >>>>>>> feature1

Git用`<<<<<<<`，`=======`，`>>>>>>>`标记处不同的分支的内容，我们修改如下后保存：

Creating a new branch is quick and simple.

再提交：

$ git add readme.txt
    $ git commit -m "conflict fixed"
    [master d5a73d5] conflict fixed

用带参数的`git log`也可以看到分支的合并情况：

$ git log --graph --pretty=oneline --abbrev-commit
    *   d5a73d5 (HEAD -> master) conflict fixed
    |\
    | * 3e4afc5 (feature1) AND simple
    * | f2ab727 & simple
    |/
    * b3d6a1b branch test
    * 7a5f61e (origin/master) remove test.txt
    * e582712 add test.txt
    * 43c6d2e 修改文件后缀名
    * 1fe593f 修改文件后缀名
    * 6471744 understand how stage works.
    * 001988f append GPL
    * 65eb9e3 add distributed
    * cf2ccdd wrote a readme file
    * 572efcc Initial commit

最后，删除`feature1`分支：

$ git branch -d feature1
    Deleted branch feature1 (was 3e4afc5).

##### 小结 #####

--------------------

当Git无法自动合并分支时，就必须首先解决冲突。解决冲突后，再提交，合并完成。

解决冲突就是把Git合并失败的文件手动编辑为我们希望的内容，再提交。

用`git log --graph`命令可以看到分支合并图。