git子树合并和git-subtree有什么不同？

Question

我刚刚发现git-subtree工具不久前成为主要git repo https://github.com/apenwarr/git-subtree/的一部分。

然而，我并不完全理解这个工具在已经存在的"git read-tree“+ "git merge -s subtree”上提供了什么功能。git-subtree的唯一用途是让结果提交历史看起来更好，还是它有更多我忽略了的功能？

Answer 1

您描述的命令将子树读入存储库。正如the documentation.等人所描述的那样，git-subtree命令有更多选项，您可以(为简单起见对其进行注释)：

add::
    Create the <prefix> subtree by importing its contents
    from the given <refspec> or <repository> and remote <refspec>.
merge::
    Merge recent changes up to <commit> into the <prefix>
    subtree.
pull::
    Exactly like 'merge', but parallels 'git pull' in that
    it fetches the given commit from the specified remote
    repository.
push::
    Does a 'split' (see above) using the <prefix> supplied
    and then does a 'git push' to push the result to the 
    repository and refspec. This can be used to push your
    subtree to different branches of the remote repository.
split::
    Extract a new, synthetic project history from the
    history of the <prefix> subtree.  The new history
    includes only the commits (including merges) that
    affected <prefix>, and each of those commits now has the
    contents of <prefix> at the root of the project instead
    of in a subdirectory.  Thus, the newly created history
    is suitable for export as a separate git repository.

也有各种各样的标志来帮助和操纵上面的内容。我相信所有这些选项以前都是通过管道命令链提供的。git-subtree.sh只是包装了它们，并使它们更容易执行。

Answer 2

如果你看一下以前的子树代码，然后将它作为一个contrib模块添加到git中：https://github.com/apenwarr/git-subtree/blob/master/git-subtree.sh，你会发现git子树工具实际上是一个更高级的包装器，它包含了更低级别的git子树合并策略。

它基本上以一种合理的方式利用这些策略，使子树管理变得更加容易。尤其是--壁球的东西真的非常有用。