Githug是一个用来了解、熟悉Git的一个非常好的游戏。

目前网站上收录的都是之前只有55关的解题方法，没有新增的rebase_onto这一关的内容。现在Githug一共有56关。现将新增的42关的解答内容更新如下：

第42关的题目如下:

Name: rebase_onto
Level: 41
Difficulty: **You have created your branch from `wrong_branch` and already made some commits, and you realise that you needed to create your branch from `master`. Rebase your commits onto `master` branch so that you don't have `wrong_branch` commits.

通过查找，在git rebase中有以下用法：

Here is how you would transplant a topic branch based on one branch to another, to pretend that you forked the topicbranch from the latter branch, using rebase --onto.First let's assume your topic is based on branch next. For example, a feature developed in topic depends on somefunctionality which is found in next.o---o---o---o---o  master\o---o---o---o---o  next\o---o---o  topicWe want to make topic forked from branch master; for example, because the functionality on which topic depends wasmerged into the more stable master branch. We want our tree to look like this:o---o---o---o---o  master|            \|             o'--o'--o'  topic\o---o---o---o---o  nextWe can get this using the following command:git rebase --onto master next topic

所以，第42关的通关方法如下：

 git rebase --onto master wrong_branch readme-update

祝通关顺利！