Git – Merge Repositories Without Losing Commit History

Sometimes, you need to merge multiples repos, but you don’t want to loose your commit history. In this tutorial, it’s basically repoSource1 + repoSource2 = repoTarget.

Steps

• Create source repoSource1, 2 (optionnal)
• Check existing history on repoSource1, 2
• Merge repoSource1, 2, to repoTarget
• Check history on repoTarget

1. Create repos 1, 2 (optionnal)

In GIT command line > create repo : create folder > init git > add commit: create file > add to git > commit.

cd git
mkdir repoSource1
cd repoSource1
git init
copy null > file1.txt
git add *
git commit -m "create file1.txt"

cd git
mkdir repoSource2
cd repoSource2
git init
copy null > file2.txt
git add *
git commit -m "create file2.txt"

2. Check histories on existing repos

In GIT command line > repo 1 > git log > repo 2 > git log.

cd git/repoSource1
git log

cd git/repoSource2
git log

3. Merge repos 1, 2, to repo 3

In GIT command line > create target repo > add remote repo > merge > repeat…

cd git
mkdir repoTarget
cd repoTarget
git init
 
git remote add repoSource2 ..\repoSource2
git fetch repoSource2
git merge repoSource2/master --allow-unrelated-histories
 
git log
 
git remote add repoSource1 ..\repoSource1
git fetch repoSource1
git merge repoSource1/master --allow-unrelated-histories
 
git log

4. Compare histories between repos

In GIT command line > for each repo: > git log > compare commit hash code and date

cd git\repoTarget
git log
 
cd ..\repoSource1
git log
 
cd ..\repoSource2
git log

Conclusion

With this method, commit history and order (by date) is preserved.

Source

https://github.com/DamienFremont/blog/tree/master/20170614-git-merge-repositories-without-losing-commit-history https://github.com/DamienFremont/blog/tree/master/20170614-git-merge-repositories-without-losing-commit-history

References

Merging Two Git Repositories Into One Repository Without Losing File History Merging Two Git Repositories Into One Repository Without Losing File History

http://stackoverflow.com/questions/26502970/merge-multiple-git-repositories-into-one-keeping-branches-history http://stackoverflow.com/questions/26502970/merge-multiple-git-repositories-into-one-keeping-branches-history

Origin

https://damienfremont.com/2017/06/14/git-merge-repositories-without-losing-commit-history/