JuneYuan / Git Troubleshooting

Created Sun, 07 Apr 2019 21:52:09 +0800
803 Words

Q1. 相继执行 1) git rebase master 2) git rebase --skip 3) git rebase --abort 后，没有回到 1) 之前的状态，而是呈现 2) 之后的状态，有几个提交不见了。怎么才能恢复到 1) 之前？

虽然当前分支由于某种原因缺失了几个 commit, 但是 git 本身并不会删除 commit, 它们还是会被记录下来。只要找到对应的 sha1 hash, 就有办法恢复。具体见 Q2.

这篇文章详细叙述了上述问题的发生和解决过程。

// TODO figure out how rebase --skip works

Q2. commit “丢了”怎么找回？

“丢失”原因可能是不小心执行了 git reset --hard 、误删了一个分支，或者是不恰当的 rebase 等。

Solution 1

git reflog

官方文档描述：“当你在工作时， Git 会在后台保存一个引用日志(reflog)，引用日志记录了最近几个月你的 HEAD 和分支引用所指向的历史。使用 git reflog 可以查看引用日志。”

Variation:

git show HEAD@{5} // 查看仓库中 HEAD 在五次前的所指向的提交

git show master@{yesterday} // 查看 master 分支昨天指向哪个提交

git log -g // 查看类似于 git log 输出格式的引用日志信息

Solution 2

vim .git/logs/HEAD

// TODO .git/logs 记录的内容与 reflog 有何异同？

Q3. 高效解决冲突的办法？

以下步骤摘自 stackoverflow 的一则回答——

Try: git mergetool

Below is the sample procedure to use vimdiff for resolve merge conflicts.

Step 1: Run following commands in your terminal

git config merge.tool vimdiff
git config merge.conflictstyle diff3
git config mergetool.prompt false

This will set vimdiff as the default merge tool.

Step 2: Run following command in terminal

git mergetool

Step 3: You will see a vimdiff display in following format

  +----------------------+
  |       |      |       |
  |LOCAL  |BASE  |REMOTE |
  |       |      |       |
  +----------------------+
  |      MERGED          |
  |                      |
  +----------------------+

These 4 views are

LOCAL – this is file from the current branch

BASE – common ancestor, how file looked before both changes

REMOTE – file you are merging into your branch

MERGED – merge result, this is what gets saved in the repo

You can navigate among these views using ctrl+w. You can directly reach MERGED view using ctrl+w followed by j.

Step 4. You could edit the MERGED view the following way

If you want to get changes from REMOTE

:diffg RE

If you want to get changes from BASE

:diffg BA

If you want to get changes from LOCAL

:diffg LO

Step 5. Save, Exit, Commit and Clean up

:wqa save and exit from vi

git commit -m "message"

git clean Remove extra files (e.g. *.orig) created by diff tool.

Q4. git rebase master 时，由于当前分支对一处代码块的多次修改，导致要反复解决冲突，怎么办？

可以先把当前分支的多次修改整合为一个，再 rebase master, 这样就只需要 apply 一次修改、解决一次冲突。用的还是 rebase 命令，只不过参数不是 branch name, 而是 commit hash.

假如当前分支的最近 5 次提交互相存在冲突，那么就执行：

git rebase --interactive HEAD@{6} // HEAD@{6} 代表上述 5 次冲突之前的 commit, 可以理解为“坐标原点”，基于这个点开始，整合之后的所有提交

Reference