How to update git submodule

Question

I have just done a git merge <merging_branch_name> in the app and resolved many conflicts.

But when I do git status, I can see list of submodules with (new commits) in the message. It looks like the submodule (branch/tag) versions have not been updated.

For example:

modified:   plugins/myplugin.git (new commits)

How do I update the submodules with the versions (with the <merging_branch_name>)

I get like this in git bash

my_app (current_branch  |MERGING), 

so when I do git status, I get list of submodules as below

 modified:   plugins/plugin1.git (new commits)
 modified:   plugins/plugin2.git (new commits)
 modified:   plugins/plugin3.git (new commits)
 modified:   plugins/plugin4.git (new commits)

How do I solve this?

Answer 1

To update a submodule content to the new SHA1, this should be enough:

# the submodule content needs to be updated
git submodule update --init

# the parent repo needs to record the new submodule SHA1
git add plugins/myplugin

Answer 2

Let us say you have two branches master and hotifx. In master the head of the submodule is at 123456 in hotfix at abcdef. (let us say that abcdef is newer than 123456). If you have checked out master and merge hotfix the submodule head will move to abcdef but the code in the submodule is not checked out to this new head. If you enter now git diff you will see that the submodule points to 123456 but this is not correct, since you want to point to abcdef. If you would now enter

git add pathToSubmodule

the old 123456 is added to the index. This is the wrong commit. What you have to to is to move the head to the correct commit and this is done by simple calling

git submodule update

Answer 3

Submodules basically point to a specific commit in the submodule that was used when making a commit in the parent git repository. It seems that after your merging, the submodules are ahead of what is expected after the merge. You have two choices:

• go back to the commit where the submodule currently points to
• update your parent repository to use the new submodule states

The first option was pointed out by the others as

git submodule update

The second option, and I think this is what you are asking for, is done with

git add plugins/plugin?.git
git commit -m 'update submodules'

which will update your HEAD state to store the current submodule references.

---

You can check what is going on by looking at

git ls-tree HEAD | grep 'plugin1.git'

before and after updating the submodule. Compare this reference to the current commit in this plugin:

cd plugins/plugin1.git
git rev-parse HEAD