Calculating total lines added/deleted after a merge?

Question

I recently took a branch with a lot of commits and merged it back into my master branch. If I needed to go back and see how many lines were added or deleted because of that merge, how would I go about doing that?

Answer 1

git diff has a --shortstat option which would have been useful before the merge as then you could've just done git diff --shortstat ..branch/to/merge from your main branch.

If the merge wasn't a fast-forward, then you'll have generated a merge commit. That will have the parent information for both branches. You can use those to do git diff --shortstat parent1..mergecommit to show what changes happened when moving from the first parent (your main branch) to the result of the merge commit.

If the merge was a fast-forward, then you just need to know what the sha1 of your branch was before the merge and compare that to the current. You could probably get that from git reflog.