git commit --amend在分离的HEAD状态 [英] git commit --amend in detached HEAD state

问题描述

我知道修改旧的GIT提交的正确方法是使用 rebase --interactive ，但是为了弄清楚概念，我想理解

I understand that the correct way of amending an old GIT commit is to use rebase --interactive, but just to get clear on the concepts, I would like to understand what happens when I do

• git checkout< commit>


• 更改文件中的内容


• 将更改后的文件添加到索引中


• ，然后 git提交。 --amend

• git checkout <commit>
• change something in a file
• add the changed file to the index
• and then git commit . --amend

执行此操作时，它没有修改提交，而是分支了一个新的提交

When I do this, instead of amending the commit, it branches a new commit off of the PARENT of that same commit.

这只是GIT告诉我无法修改已经有子项提交的提交的方法吗？

Is this just GIT's way of telling me that I cannot amend a commit that already already has children commits?

推荐答案

在Git中，一旦创建了提交，就将其固定在石头上；您无法更改。您可以做的所有事情-通过对其进行修改，精心挑选等-创建一个新的类似于目录的提交。

In Git, once a commit is created, it's set in stone; you cannot change it. All you can do—by amending it, cherry-picking it, etc.—is create a new commit that "resembles" it.

我了解您的困惑：修改有点用词不当；这有点令人误解，因为它建议修改某些内容。在Git中，修改提交实际上包括创建一个全新提交，该提交具有与原始提交相同的父级。

I understand your confusion: "amend" is a bit of a misnomer; it's somewhat misleading, as it suggests modifying something in place. In Git, amending a commit actually consists in creating a brand new commit that has the same parent(s) as the original commit.

作为示例，假设运行 git checkout B 之后，您处于以下情况：

As an example, let's assume that, after running git checkout B, you're in the following situation:

（您的 HEAD 是分离的，但这不重要。）无论您是否进行阶段更改，运行 git commit --amend 都会使您处于这种情况：

(Your HEAD is detached, but that's beside the point.) Whether or not you make and stage changes, running git commit --amend will put you in this situation:

提交 D 可能非常非常类似于 B ；特别是，它可能具有与 B 完全相同的补丁，完全相同的提交消息，等等。但是，（提交，作者）时间戳通常会有所不同（除非您可以根据以下内容修改提交），这意味着 D 的SHA-1与 B 的SHA-1不同；并且如果两个提交不具有相同的SHA，则它们也不是相同的提交。

Commit D may be very, very similar to B; in particular, it may have exactly the same patch, exactly the same commit message as B, etc.. However, (commit, author) timestamps will usually differ (unless you can amend a commit under a second!), which means the SHA-1 of D will differ from that of B; and if two commits don't have the same SHA, they're not the same commit.

当我们说 B 是 C 的父提交，我们的意思是 commit C 引用提交 B 通过其SHA 。
但是，提交 C 无法知道有关提交 D 的SHA的任何信息，因为提交<在 C 之后创建code> D 。因此， D 不能是 C 的父母。这就是为什么commit D 在切线上消失并且没有任何后代的原因。

When we say B is a parent commit of C, we mean commit C references commit B by its SHA. However, commit C has no way of knowing anything about the SHA of commit D, because commit D was created after C. Therefore, D cannot be C's parent. That's why commit D goes off on a tangent and doesn't have any descendants.

如果您要以以下状态着陆，

If you want to land in the following state,

其中， B'甚至与 B 只是稍有不同，应该使用 git rebase -i ，而不是 git commit --amend 。

where B' is even only slightly different from B, you should use git rebase -i, not git commit --amend.

这篇关于git commit --amend在分离的HEAD状态的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！