Show non-merge differences for two commits in git

If your merges all came from the same branch (say master) or are all contained in another branch, you can use the solution from this question.

Assuming you have a tree like the following:

         x---y-+-z-+-branch
        /     /   /
---a---b---c-+-d-+-e---master

and the two commits you would like to compare are b and branch. Then instead of comparing the two commits directly, running

git diff master...branch

will show all changes done on the branch (x,y,z) excluding everything that is also on master (c,d,e, the merges). Note that this also ignores any changes done on master that are not yet in the branch.

From the docs:

git diff [--options] commit...commit [--] […​]

This form is to view the changes on the branch containing and up to the second commit, starting at a common ancestor of both commits. "git diff A...B" is equivalent to "git diff $(git-merge-base A B) B".

I didn't know the --no-merges -o options but here another solution (I suppose that merges have been done from master) :

git checkout -b temp
git rebase --onto master branch-start branch-end
git diff master

Your question is slightly ambiguous but I think you want this.

git log --no-merges -p branch-start..branch-end