Pushing files from one Git repository to another

Question

I have 2 Git repositories with basically the same structure, but repository B has only some of the contents of repository A.

Repository A has newer commits that I need to push to B (but only the necessary files).

I have so far git clone'd the repositories to my local workstation. How should I replace the necessary files in repository B with files from repository A?

My naive attempt was git mv /A/source/* /B/source/ which resulted in:

fatal: /B/source/: '/B/source/' is outside repository

Since I'm fairly new to git, I'm not 100% sure what I should be trying to achieve. I'll try and explain the context: We have active development going on in repository A. Repository B is currently for a third party to access parts of the content (they only need parts of it). Repository A has version 1.6, B has 1.4. So my goal is to push the necessary new content to B. I guess this would be commiting the commits made to A during 1.5 and 1.6 to B?

Answer 1

The most reliable way to do this, I think, is to transfer the actual commits themselves. Use git format-patch to pull the commits from A which are not on B , or vice versa, and write them out to .patch files.

Then, in the other repo, use git apply to apply the .patch file commits to that repo. If there are conflicts you will have an opportunity to resolve them.

This is basically the same as "cherry-picking" commits, but across repositories rather than across branches.

(You can also use git am instead of git apply if you want, it's only a bit different.)

Answer 2

What we ended up doing was:

git rm /B/<files_to_replace> 

cp /A/<necessary_files> /B/

git add ...

This might not be the correct way to do it, but we were in a bit of a hurry and it'll get the job done for now. Thanks for the help! :)