How to merge branch and retain the authorship

Question

let's say that my colleage John has created a branch called 'john'. It has 10 committs by John. When it comes to merging back to master they ask me to do merging.

This is what I do

git checkout -b john origin/john
git rebase master
git checkout master
git merge john --squashed
git add .
git commit -m 'merged branch john'

However now what happens is that it is my id against the merged commit. And later people come asking me why did I change certain part of code.

How do I collapse all the comitts in john branch into one commit such that John is the author. I guess git commit interactive can help but could not quite understand.

Answer 1

The issue here is that git merge --squash will apply the same changes as a normal merge, but without retaining the merge information. Then, when you commit, it's the same as any commit you make: it's attributed to you. You could change the commit's author information using git commit --author="Original Author <email@server>". See git-commit(1) for more information on the --author switch.

But the question I have is: why are you squashing the merge? Why not just do a non-squashed merge? If anyone does a git blame, it will be appropriately attributed to the commit by the original author.

Answer 2

If you do the following:

git checkout -b john origin/john
git rebase master
git checkout master
git merge --no-ff john # forces a merge commit to be recorded

you'll be able to both both retain the authorship of John's commits and be able to revert the merge by reverting the SHA of the merge commit.