How to merge two repos

Just imagine we have two git repos and one of them haven’t update a lot of time. We want to merge it. How we should to do it the situation. Don’t forget exists lasted changes in repo

$ git fetch -ap 
$ git pull

First of all we need add remote source

$ git remote add gerrit ssh://gerrit.com:29418/XXX/XXX

Check it. Should be two remotes origin and second remote url gerrit

$ git remote -v

# Output
gerrit	ssh://gerrit.com:29418/XXX/XXX (fetch)
gerrit	ssh://gerrit.com:29418/XXX/XXX (push)
origin	https://github.com/YYYY/YYYY (fetch)
origin	https://github.com/YYYY/YYYY (push)

Call master branch from other remote with prefix. That action to do more easy to filter in git log and merge branch in future

$ git checkout -b gerrit gerrit/master

Now need choice branch with missing changes

$ git checkout gerrit

Merge changes from origin repo which contain lasted changes

$ git merge origin/master

Add new commit

$ git commit -a -m "Sync"

I recommend to use squash, if we wouldn’t like add each commit separately

$ git rebase -i gerrit/master

Finally push to gerrit repo

$ git push gerrit HEAD:refs/for/master

It is all.