Consider the following scenario:
I have developed a small experimental project A in its own Git repo. It has now matured, and I'd like A to be part of larger project B, which has its own big repository. I'd now like to add A as a subdirectory of B.
How do I merge A into B, without losing history on any side?
If you want to merge
git remote add project-a /path/to/project-a
git fetch project-a --tags
git merge --allow-unrelated-histories project-a/master # or whichever branch you want to merge
git remote remove project-a
Taken from: git merge different repositories?
This method worked pretty well for me, it's shorter and in my opinion a lot cleaner.
In case you want to put
project-a into a subdirectory, you can use
filter-branch is discouraged). Run the following commands before the commands above:
git filter-repo --to-subdirectory-filter project-a
An example of merging 2 big repositories, putting one of them into a subdirectory: https://gist.github.com/x-yuri/9890ab1079cf4357d6f269d073fd9731
--allow-unrelated-histories parameter only exists since git >= 2.9. See Git - git merge Documentation / --allow-unrelated-histories
--tags as suggested by @jstadler in order to keep tags.