How to push the forked repository which has submodule?

Question

There is a A project and the A project has a submodule S
A
|-S
|-B
|-C

A repo: git@github.com:benjamin/A.git
S repo: git@github.com:owner/S.git

To contribute some bug fix, I forked the A repository and cloned it.

$ git clone git@github.com:benjamin/A.git

and then to download a submodule S I commanded

$ git submodule init
$ git submodule update

Okay, the code tree are made well, and I fixed the bug at a file in A and a file in S.
To commit and push the two files,

$ cd S
$ git add modified_file
$ git commit -a -m 'submodule commit'
$ git push

But the push is not work.

ERROR: Permission to owner/S.git denied to benjamin.
fatal: The remote end hung up unexpectedly

Should I also fork S repository either? How do you do in this case?

Answer 1

Yes, a submodule is a git repo in itself.
You need to

• fork both repo,
• clone them both,
• make a symlink between A and S locally (just for your code to compile, ie don't bother with the submodule status of S locally)
• commit in both local repo your changes and push them to your respective fork
• make two pull requests (one for A, one for S)

Only the maintainer of A and S will be able to:

• apply your pull request in S and commit
• apply your pull request in A
• commit in A, recording the new SHA1 of S (submodule) and the changes in A.

---

Mark Longair mentions that you can:

• clone your fork of A
• git submodule init
• git submodule update (that will clone S to the right SHA1, but with 'S' as a remote, not 'forked-S')
• cd S
• git remote set-url origin <SSH-url-of-fork-of-S>
• git checkout -b my-changes-to-S: make a branch in order to record your local modification, and to avoid being in a detached HEAD mode.