将两个git存储库合并为一个，保留（重命名）主分支

Question

Preamble

I have two separate projects that grew into one. They both have their own git repository.

/project/
/project/app/
/project/app/.git/
/project/helper/
/project/helper/.git/

Both git repositories have some unique branches, and both have of course their own master branch.

Question

I would like to merge both projects into one like so:

/project/.git/

The unique branches aren't relevant and they can be removed. But I would like the master branches to be renamed and kept, eg masterApp and masterHelper , so that I have a new single repository for the whole project with both branches and a new master branch.

Is this possible? If so, it would involve some renaming trickery because each repository suddenly includes their own parent directory.

Details

These repositories are local for now, so we don't have to worry about remote origins or breaking the commit history for other users. I do want to keep the commit history for the individual (renamed) master branches though, and (if possible) the files that are staged/tracked in those branches.

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I have found the following similar question: How do you merge two git repositories?

That question is about merging one repository into the other repository. That makes this question slightly different, but I think the solution might be close. However, I am not experienced enough with git to figure out how that solution would apply to my scenario.

Answer 1

One way to do it would be to make a seperate git repository

mkdir combinedProject
cd combinedProject
git init

then add both projects as remotes to the combinedProject

git remote add -f App /path/to/App
git remote add -f Helper /path/to/Helper

then create separate masterApp and masterHelper branches

git branch masterApp --track App/master
git branch masterHelper --track Helper/master

then create a master branch from masterApp and merge masterHelper into it.

git checkout masterApp
git checkout -b master
git merge masterHelper

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Without creating a new repo you could do the same thing in the App repo

git checkout -b masterApp

then adding the remote for Helper and creating a masterHelper Branch

git remote add -f Helper /path/to/Helper
git branch masterHelper --track Helper/master

then mergeing masterHelper into master

git checkout master
git merge masterHelper