如果有关文件的路径在两个repo中是相同的，并且您希望只带来一个文件或一小组相关文件，一个简单的方法是使用git进行选择。

第一步是使用git fetch <remote-url>将从另一个repo提交到您自己的本地repo。这将使FETCH_HEAD指向从另一个repo提交的头;如果你想在你完成了其他的取回之后保留对该提交的引用，你可以使用git tag other-head FETCH_HEAD来标记它。

You will then need to create an initial commit for that file (if it doesn't exist) or a commit to bring the file to a state that can be patched with the first commit from the other repo you want to bring in. You may be able to do this with a git cherry-pick <commit-0> if commit-0 introduced the files you want, or you may need to construct the commit 'by hand'. Add -n to the cherry-pick options if you need to modify the initial commit to, e.g., drop files from that commit you don't want to bring in.

在此之后，您可以继续精选后续提交，在必要时再次使用-n。在最简单的情况下(所有提交都是你想要的，并且干净地应用)，你可以在cherry-pick命令行上给出完整的提交列表:git cherry-pick <commit-1> <commit-2> <commit-3> ....

如果有关文件的路径在两个repo中是相同的，并且您希望只带来一个文件或一小组相关文件，一个简单的方法是使用git进行选择。

第一步是使用git fetch <remote-url>将从另一个repo提交到您自己的本地repo。这将使FETCH_HEAD指向从另一个repo提交的头;如果你想在你完成了其他的取回之后保留对该提交的引用，你可以使用git tag other-head FETCH_HEAD来标记它。

You will then need to create an initial commit for that file (if it doesn't exist) or a commit to bring the file to a state that can be patched with the first commit from the other repo you want to bring in. You may be able to do this with a git cherry-pick <commit-0> if commit-0 introduced the files you want, or you may need to construct the commit 'by hand'. Add -n to the cherry-pick options if you need to modify the initial commit to, e.g., drop files from that commit you don't want to bring in.

在此之后，您可以继续精选后续提交，在必要时再次使用-n。在最简单的情况下(所有提交都是你想要的，并且干净地应用)，你可以在cherry-pick命令行上给出完整的提交列表:git cherry-pick <commit-1> <commit-2> <commit-3> ....

在我的例子中，我不需要保存我正在迁移的回购，也不需要保存任何以前的历史记录。我用不同的遥控器，截取了同一根树枝的补丁

#Source directory
git remote rm origin
#Target directory
git remote add branch-name-from-old-repo ../source_directory

在这两个步骤中，我能够让另一个回购的分支出现在同一个回购中。

最后，我设置这个分支(我从另一个回购导入)遵循目标回购的主线(所以我可以准确地区分它们)

git br --set-upstream-to=origin/mainline

现在它的行为就好像它只是我在同一次回购中推的另一个分支。

使用来自http://blog.neutrino.es/2012/git-copy-a-file-or-directory-from-another-repository-preserving-history/的灵感，我创建了这个Powershell函数来做同样的事情，到目前为止对我来说效果很好:

# Migrates the git history of a file or directory from one Git repo to another.
# Start in the root directory of the source repo.
# Also, before running this, I recommended that $destRepoDir be on a new branch that the history will be migrated to.
# Inspired by: http://blog.neutrino.es/2012/git-copy-a-file-or-directory-from-another-repository-preserving-history/
function Migrate-GitHistory
{
    # The file or directory within the current Git repo to migrate.
    param([string] $fileOrDir)
    # Path to the destination repo
    param([string] $destRepoDir)
    # A temp directory to use for storing the patch file (optional)
    param([string] $tempDir = "\temp\migrateGit")

    mkdir $tempDir

    # git log $fileOrDir -- to list commits that will be migrated
    Write-Host "Generating patch files for the history of $fileOrDir ..." -ForegroundColor Cyan
    git format-patch -o $tempDir --root -- $fileOrDir

    cd $destRepoDir
    Write-Host "Applying patch files to restore the history of $fileOrDir ..." -ForegroundColor Cyan
    ls $tempDir -Filter *.patch  `
        | foreach { git am $_.FullName }
}

这个例子的用法:

git clone project2
git clone project1
cd project1
# Create a new branch to migrate to
git checkout -b migrate-from-project2
cd ..\project2
Migrate-GitHistory "deeply\buried\java\source\directory\A" "..\project1"

完成此操作后，可以在合并migrate-from-project2分支之前重新组织该分支上的文件。

通过使用git-filter-repo，这变得更简单。

为了移动project2/sub/dir到project1/sub/dir:

# Create a new repo containing only the subdirectory:
git clone project2 project2_clone --no-local
cd project2_clone
git filter-repo --path sub/dir

# Merge the new repo:
cd ../project1
git remote add tmp ../project2_clone/
git fetch tmp master
git merge remotes/tmp/master --allow-unrelated-histories
git remote remove tmp

简单地安装工具:pip3 install git-filter-repo (更多细节和选项在README)

# Before: (root)
.
|-- project1
|   `-- 3
`-- project2
    |-- 1
    `-- sub
        `-- dir
            `-- 2

# After: (project1)
.
├── 3
└── sub
    └── dir
        └── 2

我发现Ross Hendrickson的博客很有用。这是一种非常简单的方法，您可以创建应用于新回购的补丁。更多细节请参见链接页面。

它只包含三个步骤(复制自博客):

# Setup a directory to hold the patches
mkdir <patch-directory>

# Create the patches
git format-patch -o <patch-directory> --root /path/to/copy

# Apply the patches in the new repo using a 3 way merge in case of conflicts
# (merges from the other repo are not turned into patches). 
# The 3way can be omitted.
git am --3way <patch-directory>/*.patch

唯一的问题是我不能一次性应用所有补丁

git am --3way <patch-directory>/*.patch

在Windows下，我得到了一个InvalidArgument错误。所以我不得不一个接一个地打补丁。