I've only just started to use Git and think it is wonderful, however I'm a little confused over what the merge command does.
Let us say we have a working project in the branch "A".
I go home and make changes to this branch and save it as "B". Another programmer makes changes to "A" and saves it as "C".
Is there a way to merge the two branches "B" and "C" together, then commit the changes as a new branch, say "D"?
Or am missing the point of 'merge'?
merge is used to bring two (or more) branches together.
A little example:
$ # on branch A:
$ # create new branch B
$ git checkout -b B
$ # hack hack
$ git commit -am "commit on branch B"
$ # create new branch C from A
$ git checkout -b C A
$ # hack hack
$ git commit -am "commit on branch C"
$ # go back to branch A
$ git checkout A
$ # hack hack
$ git commit -am "commit on branch A"
So now there are three separate branches (namely A B and C) with different heads.
To get the changes from B and C back to A, checkout A (already done in this example) and then use the merge command:
$ # create an octopus merge
$ git merge B C
Your history will then look something like this:
…-o-o-x-------A
|\ /|
| B---/ |
\ /
C---/
If you want to merge across repository/computer borders, have a look at git pull command, e.g. from the PC with branch A (this example will create two new commits):
$ # pull branch B
$ git pull ssh://host/… B
$ # pull branch C
$ git pull ssh://host/… C
If you want to merge changes in SubBranch to MainBranch
git checkout MainBranchgit merge SubBranch
Case: If you need to ignore the merge commit created by default, follow these steps.
Say, a new feature branch is checked out from master having 2 commits already,
Checkout a new feature_branch
Feature branch then adds two commits-->
Now if you want to merge feature_branch changes to master, Do git merge feature_branch sitting on the master.
This will add all commits into master branch (4 in master + 2 in feature_branch = total 6) + an extra merge commit something like 'Merge branch 'feature_branch'' as the master is diverged.
If you really need to ignore this merge commit and add as new commit like 'Integrated feature branch changes into master', Run git merge feature_merge --no-commit.
With --no-commit, it perform the merge and stop just before creating a merge commit, We will have all the added changes in feature branch now in master and get a chance to create a new merge commit as our own.
Edit 2023: You can now have the option to change the merge commit interactively in newer versions of git without specifying the --no-commit option.
Read here for more : https://git-scm.com/docs/git-merge
To change your subBranch to main
git branch -m main <BRANCH>;
git fetch origin;
git branch -u origin/<BRANCH> <BRANCH>;
git remote set-head origin -a
