您几乎已经自己说过了： 一次提交：

  $> git checkout HEAD〜1 path / to / file.ext 
 

然后提交它：

  $> git commit -a -m'从旧版本检索的文件'
 

如果仅对该文件所做的更改目前在上次提交中，您甚至可以使用 git-revert ：

  $> git revert HEAD 
 

我认为将它作为一个单独的提交会更好，因为它会准确地告诉您你已经回复了什么，为什么。然而，你可以通过使用 - 修改开关到 git-commit 来压缩这个到之前的提交中。

I recently committed a file to the HEAD of my branch which has errors in it. I need to do the following things:

• Get that file from one commit previous to HEAD


• Commit that file back into HEAD

What's the best way of going about that?

You've practically said it yourself:

First get the file back from one commit before:

$> git checkout HEAD~1 path/to/file.ext

Then commit it:

$> git commit -a -m 'Retrieved file from older revision'

If only the changes to that file where present in the last commit, you can even use git-revert:

$> git revert HEAD

I think it would be better to make this a separate commit, because it tells you exactly what you've reverted, and why. However, you can squash this into the previous commit by using the --amend switch to git-commit.