git手动master_gitpullrebase的正确使用

在多人使用同一个远程分支合作开发的时候&＃xff0c;很可能出现 push 代码的时候出现以下问题&＃xff1a;

$ git push origin master

# 结果如下

To github.com:hello/demo.git

! [rejected] master -> master (fetch first)

error: failed to push some refs to &＃39;git&＃64;github.com:hello/demo.git&＃39;

hint: Updates were rejected because the remote contains work that you do

hint: not have locally. This is usually caused by another repository pushing

hint: to the same ref. You may want to first integrate the remote changes

hint: (e.g., &＃39;git pull ...&＃39;) before pushing again.

hint: See the &＃39;Note about fast-forwards&＃39; in &＃39;git push --help&＃39; for details.

很明显此时远程分支有新的 commit 未同步到本地&＃xff0c;无法推送。正常情况下我们会执行以下操作&＃xff1a;

$ git pull origin master

# 结果如下

remote: Counting objects: 2, done.

remote: Compressing objects: 100% (2/2), done.

remote: Total 2 (delta 1), reused 0 (delta 0)

Unpacking objects: 100% (2/2), done.

From github.com:hello/demo

3824da0..f318a05 master -> origin/master

Merge made by the &＃39;recursive&＃39; strategy.

one.md | 2 &＃43;&＃43;

1 file changed, 2 insertions(&＃43;)

$ git push origin master

# 结果如下

Enumerating objects: 10, done.

Counting objects: 100% (8/8), done.

Delta compression using up to 8 threads

Compressing objects: 100% (8/8), done.

Writing objects: 100% (8/8), 1.24 KiB | 1.24 MiB/s, done.

Total 8 (delta 5), reused 0 (delta 0)

To github.com:hello/demo.git

f318a05..1aefef1 master -> master

确实 push 成功了&＃xff0c;但是此时用 git log 查看以下提交记录&＃xff1a;

$ git log

# 结果如下

commit 1aefef1a2bedbd3ebd82db8dcf802011a35a9888 (HEAD -> master, origin/master, origin/HEAD)

Merge: 24cfa5c f318a05

Author: hello

Date: Tue Jul 23 09:53:47 2019 &＃43;0800

Merge branch &＃39;master&＃39; of github.com:hello/demo

commit 24cfa5c3ad271e85ff0e64793bf2bcc9d700c233

Author: hello

Date: Tue Jul 23 09:50:06 2019 &＃43;0800

feat: 新功能提交

commit f318a05b1a4cbc0a6cf8d7dc7d3fb99cbafb0363

Author: world

Date: Tue Jul 23 09:48:20 2019 &＃43;0800

feat: 其他功能提交

...

你会发现多出了一条 merge commit&＃xff0c;这个 commit 就是在执行 git pull origin master 的时候自动生成的。如果多人多次如此操作&＃xff0c;那么提交记录就会出现很多条这种自从生成的 merge commit&＃xff0c;非常难看。

要解决以上问题&＃xff0c;不再出现自动生成的 merge commit&＃xff0c;那么只要在执行 git pull origin master 的时候带上 --rebase 即可&＃xff1a;

$ git pull --rebase origin master

$ git push origin master

项目示例

现在通过一个示例项目来示范以上命令的用法。项目(demo)的结构如下&＃xff1a;

# 在 demo 目录下执行以下命令

$ ls

# 结果如下

one.md two.md

$ cat one.md

# 结果如下

hello one

$ cat two.md

#结果如下

hello two

A、B两位开发同学使用一个远程分支(master)合作开发。A同学修改了 one.md 文件&＃xff0c;提交了一个 commit 并且已经推送到远程分支 master&＃xff1a;

$ cat one.md

# 结果如下

hello one

new feature for one

$ git push origin master

# 结果如下

Enumerating objects: 4, done.

Counting objects: 100% (4/4), done.

Delta compression using up to 8 threads

Compressing objects: 100% (4/4), done.

Writing objects: 100% (4/4), 1.24 KiB | 1.24 MiB/s, done.

Total 4 (delta 3), reused 0 (delta 0)

To github.com:hello/demo.git

f318a05..1aefef1 master -> master

此时B同学不知情&＃xff0c;也并未将远程分支的更新拉到本地。B同学修改了 two.md 文件&＃xff0c;也提交了一个 commit 并尝试推送到远程分支 master&＃xff1a;

$ cat two.md

# 结果如下

hello two

new feature for two

$ git push origin master

# 结果如下

To github.com:hello/demo.git

! [rejected] master -> master (fetch first)

error: failed to push some refs to &＃39;git&＃64;github.com:hello/demo.git&＃39;

hint: Updates were rejected because the remote contains work that you do

hint: not have locally. This is usually caused by another repository pushing

hint: to the same ref. You may want to first integrate the remote changes

hint: (e.g., &＃39;git pull ...&＃39;) before pushing again.

hint: See the &＃39;Note about fast-forwards&＃39; in &＃39;git push --help&＃39; for details.

发现报错&＃xff0c;无法推送。此时执行以下命令&＃xff1a;

$ git pull --rebase

$ git push origin master

即可成功推送。

注意事项

执行 git pull --rebase 的时候必须保持本地目录干净。即&＃xff1a;不能存在状态为 modified 的文件。(存在Untracked files是没关系的)

如果出现冲突&＃xff0c;可以选择手动解决冲突后继续 rebase&＃xff0c;也可以放弃本次 rebase

执行 git pull --rebase 的时候必须保持本地目录干净

有 modified 状态的文件

本地有受版本控制的文件改动的时候&＃xff0c;执行以上命令&＃xff1a;

$ git pull --rebase

# 结果如下

error: cannot pull with rebase: You have unstaged changes.

error: please commit or stash them.

会出现以上报错&＃xff0c;无法操作。

此时查看以下文件状态&＃xff1a;

$ git status

# 结果如下

On branch master

Your branch is ahead of &＃39;origin/master&＃39; by 1 commit.

(use "git push" to publish your local commits)

Changes not staged for commit:

(use "git add ..." to update what will be committed)

(use "git checkout -- ..." to discard changes in working directory)

modified: two.md

no changes added to commit (use "git add" and/or "git commit -a")

就是因为本地有文件改动尚未提交造成的。此时有两种做法&＃xff1a;

如果本次修改已经完成&＃xff0c;则可以先提交(commit)一下

如果本次修改尚未完成&＃xff0c;则可以先贮藏&＃xff1a;git stash

做了以上一种操作之后再尝试 git pull --rebase&＃xff0c;不会再报错。

如果做了 git stash 操作&＃xff0c;此时可以通过 git stash pop 回到之前的工作状态。

有 Untracked files

查看本地文件状态&＃xff1a;

$ git status

# 结果如下

On branch master

Your branch is ahead of &＃39;origin/master&＃39; by 1 commit.

(use "git push" to publish your local commits)

Untracked files:

(use "git add ..." to include in what will be committed)

three.md

no changes added to commit (use "git add" and/or "git commit -a")

如果是以上这种情况&＃xff0c;直接执行 git pull --rebase 是不会有问题的。

如果出现冲突&＃xff0c;可以选择手动解决冲突后继续 rebase&＃xff0c;也可以放弃本次 rebase

在上面的示例项目中&＃xff0c;如果 A、B 同学修改了同一个文件。那么很有可能会出现冲突&＃xff0c;当 B 同学来执行命令的时候会出现如下状况&＃xff1a;

$ git pull --rebase

# 结果如下

remote: Counting objects: 6, done.

remote: Compressing objects: 100% (6/6), done.

remote: Total 6 (delta 1), reused 0 (delta 0)

Unpacking objects: 100% (6/6), done.

From gitlab.lrts.me:fed/gitlab-merge

93a1a93..960b5fc master -> origin/master

First, rewinding head to replay your work on top of it...

Applying: feat: 其他功能提交

Using index info to reconstruct a base tree...

Mone.md

Falling back to patching base and 3-way merge...

Auto-merging one.md

CONFLICT (content): Merge conflict in one.md

error: Failed to merge in the changes.

Patch failed at 0001 feat&＃xff1a;其他功能提交

hint: Use &＃39;git am --show-current-patch&＃39; to see the failed patch

Resolve all conflicts manually, mark them as resolved with

"git add/rm ", then run "git rebase --continue".

You can instead skip this commit: run "git rebase --skip".

To abort and get back to the state before "git rebase", run "git rebase --abort".

这种情况下&＃xff0c;可以手动打开 one.md 文件解决冲突&＃xff0c;然后再执行&＃xff1a;

$ git add one.md

$ git rebase --continue

解决问题。

也可以用 git rebase --abort 放弃本次 rebase 操作。

总结

多人基于同一个远程分支开发的时候&＃xff0c;如果想要顺利 push 又不自动生成 merge commit&＃xff0c;建议在每次提交都按照如下顺序操作&＃xff1a;

$ git stash

$ git pull --rebase

$ git push

$ git stash pop