为什么 git commit 在这种情况下会丢失？

Question

我的同事做了一系列粗心的pull/push操作。他最终陷入了本地提交丢失的情况

我使用 git reflog 恢复了他的提交。但是我想不通为什么他的操作会导致这种情况。有人可以放一些灯吗？

请参阅下面的 git reflog 输出和注释：

#######
# reflog is in reverse manner, most recent operation first
# test is like our "develop" branch, MTX-65 is the feature branch
# Both are remote-tracking
#######
39261b7 (HEAD -> MTX-65, origin/feature/MTX-65) HEAD@{0}: checkout: moving from test to MTX-65
7f66c72 (test) HEAD@{1}: checkout: moving from MTX-65 to test
39261b7 (HEAD -> MTX-65, origin/feature/MTX-65) HEAD@{2}: pull: Fast-forward
d51c1be HEAD@{3}: rebase finished: returning to refs/heads/MTX-65
d51c1be HEAD@{4}: rebase: Add Notification
c33d31f HEAD@{5}: pull --tags -r origin feature/MTX-65: checkout c33d31f4d0109396dea6d6bb78f47ba56097e4ac

#######
# This is the key commit that got lost
# It's not in `git log` out any more
#######
a6a7a7e HEAD@{6}: commit (merge): Warning message
3c8113c HEAD@{7}: commit (amend): Add Notification
7f551e4 HEAD@{8}: commit: Add Notification
96bcf99 HEAD@{9}: pull --tags -r origin feature/MTX-65: Fast-forward
b79bee0 HEAD@{10}: commit: personal & institution page
3cfb1aa HEAD@{11}: commit: Institution：
7f66c72 (test) HEAD@{12}: checkout: moving from test to MTX-65
7f66c72 (test) HEAD@{13}: merge MTX-65: Fast-forward
0733fd2 HEAD@{14}: checkout: moving from MTX-65 to test
7f66c72 (test) HEAD@{15}: commit (merge): Merge test
ebfaeea HEAD@{16}: checkout: moving from test to MTX-65
0733fd2 HEAD@{17}: pull: Fast-forward
1043c35 HEAD@{18}: checkout: moving from MTX-65 to test

#######
# This is a commit that still exists after the disaster
#######
ebfaeea HEAD@{19}: commit: institution 认证信息

Answer 1

我们来看看a6a7a7e HEAD@{6}: commit (merge): Warning message。

commit (merge)表示合并遇到冲突。解决冲突后，您的同事将默认提交消息更改为 Warning message。默认消息类似于 Merge made by the 'recursive' strategy.

然后您的同事运行 git pull --tags -r origin feature/MTX-65。对于 -r，获取完成后使用 git rebase 而不是 git merge。

正如manual所说，

By default, a rebase will simply drop merge commits from the todo list, and put the rebased commits into a single, linear branch.

关于 git merge 或 git rebase 哪个更好的争论很多。 git rebase 的优点之一是我们可以使用它以方便的方式创建线性历史记录。按照设计，合并提交在默认情况下会被删除，尽管 git rebase 提供 -r 和 -p 在某些情况下保留它们。

在git rebase期间，冲突预计会再次发生。理论上，如果你的同事按照他在之前git merge中的方式解决它们，那么更改就不会丢失。您可以尝试 git log --reflog -S <keywords> -p 找出在哪个提交中丢失了包括关键字在内的更改。

为什么 git commit 在这种情况下会丢失？

Why git commit can be lost in this case?

git

git-rebase

git-pull

git-reflog

reflog