What is the right way to merge branches when `git diff` shows changes but `git merge` does nothing

I get stumped when git diff other_branch shows differences and git merge other_branch does nothing. What's the right way to incorporate that "missing" code into my_branch?

This SO answer diagramed a situation similar to mine.

o---A---B---C-------G   my_branch
     \       \     /
      --*D*---E---F    other_branch

Surprisingly changes in D aren't automatically merged into my_branch when I do

git checkout my_branch
git merge other_branch

to bring in F to G

Of course I can manually create a patch and apply it to my_branch, like this:

git diff other_branch my_branch > patchfile
git checkout my_branch
patch -p1 < patchfile

But I want to do this right, without mucking up the git log. With the patch approach, git will record the changes in D and my latest patch as happening independently of each other (code churn). I want to simplify the git log and make sure others don't have unintended things happen (quietly and insidiously) when they do a git merge my_branch.

git git-merge git-diff

Edit Report

You seem to have two issues here at the same time.

Assuming a history like the one you described:

                my_branch
                    v
----A---B---C-------G   
     \       \     /
      --*D*---E---F
                  ^
             other_branch

Why the diff is not empty:

This situation is produced by the commands you mentioned, i.e. being on my_branch and then doing git merge other_branch. This action produced a merge commit G and moved the current branch (my_branch) forward, but left other_branch where it was. This is how merges always work! Naturally, there will still be a difference between my_branch (G) and other_branch (F) at this point -- they point to different commits after all.

If you want the two branches to be identical, you can move up other_branch in the following ways:

git checkout other_branch; git merge my_branch -- this is a fast-forward merge since G is a descendant of F
[while not on other_branch!] git branch -D other_branch; git branch other_branch my_branch -- this will remove other_branch and then re-create it in the same location where my_branch currently is
git checkout other_branch; git reset --hard my_branch -- this will move other_branch to point exactly where my_branch is currently pointing

After doing one of these steps, both my_branch and other_branch will be pointing to G.

Why the changes of commit D are not in my_branch (G)

Git merges histories, not changes. This

answered 2013-05-11T07:18:06.573

What is the right way to merge branches when `git diff` shows changes but `git merge` does nothing

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