Connect git historys after cut

My two repos are from the same project. I make a history cut after commit 3 and work now only with Repo ProjectnameWorking.

git log Repo "ProjectnameArchiv":

30114b2afac5d1c5a968441151ee8f91fc015ff3 4
9aa472d04501a14b5b704fde32445461f99f539a 3
1d0e5abe5daf60c0d86819938ba1aefd44b87ff5 2
766f4880e8ccf61bdc718dfae62466f800ae8119 1

git log Repo "ProjectnameWorking":

2932c4b8ea681f0a97bf151ccc46d2044e8e5a50 5
27ec1a4618f1bf0025b8ba83fd69c2607cdf78d4 4

Is there a way to connect later both historys & projectfiles to one?

git log Repo "Projectname"

2932c4b8ea681f0a97bf151ccc46d2044e8e5a50 5
27ec1a4618f1bf0025b8ba83fd69c2607cdf78d4 4
9aa472d04501a14b5b704fde32445461f99f539a 3
1d0e5abe5daf60c0d86819938ba1aefd44b87ff5 2
766f4880e8ccf61bdc718dfae62466f800ae8119 1

Edit:

Commit 4 at Repo "ProjectnameArchiv" - get new hash from cut

Solution

Yes, that is possible, but the SHAs of one of the projects will change:

Create a common remote repository:
```
/some/other/path> git init . --bare
```

Create a branch in ProjectnameArchiv at 9aa472d04501a14b5b704fde32445461f99f539a and push it to the remote:

ProjectnameArchiv> git branch merge-base 9aa472d04501a14b5b704fde32445461f99f539a
ProjectnameArchiv> git remote add origin file:///some/other/path
ProjectnameArchiv> git push --all

Do the same in the other repo but fetch instead of push:

ProjectnameWorking> git branch working-top 2932c4b8ea681f0a97bf151ccc46d2044e8e5a50
ProjectnameWorking> git remote add origin file:///some/other/path
ProjectnameWorking> git fetch origin

cherry-pick the first working commit into the archive branch:

ProjectnameWorking> git checkout -b archive origin/merge-base
ProjectnameWorking> git cherry-pick 9aa472d04501a14b5b704fde32445461f99f539a

If you have only a few commits you can continue cherry-picking, but for a larger number, rebase-ing the rest of the work branch onto the archive branch is faster:
```
ProjectnameWorking> git rebase --onto archive 9aa472d04501a14b5b704fde32445461f99f539a working-top
```
You might add git’s -i option to check what it is doing before it starts, and interrupt the process if something went wrong.

After that, the changes of the working repository are added to the archive repository but they get new SHAs.