How to check what git rebase had changed?

Is there a way to check what git rebase had changed after doing the rebase and exiting rebase mode?

I used rebase to change the author name of previous commits.

While trying to do so, I rebased in wrong branch (i.e., master) which viewed to me in the rebase file some commits that were not my target. Therefore, I just quit the editor and it said "Rebase done successfully".

At the end, I switched to my local branch (i.e., vIO) and I could change the author name but I want to check that my other rebasing trials didn't affect the history. BTW, my local branch (vIO) is not yet pushed to remote.

I tried comparing local master to remote master by:

git diff origin/master...master

This didn't bring anything. Does this mean for sure that the master branch was not affected by the rebasing?

Solution

git keeps a log for each separate branch, which you can access through the git reflog command :

git reflog master will show you the evolution of your local master branch,
git reflog vIO the evolution of your local vIO branch.

In this reflog, actions that were applied by a rebase will appear with a message :

rebase (finish): refs/heads/branchname onto eacf32bb...

The git diff origin/master...master command told you that there was no new content on master, which is a good indication.

If you want to be 100% sure master didn't move, look at the list of commits with git log :

git log --graph --oneline origin/master master

will allow you to see if there are any different commits the two branches :

if the labels master and origin/master appear on the same commit, the two branches are in sync ;
otherwise, look at the graph to understand what action should be taken (pull, push, merge, rebase ...)