Bagas,
Thanks for testing.
> I tested that, and below is `git status` after the test (using Git
2.32.0):
>
>> On branch master
>> Your branch and 'origin/master' have diverged,
>> and have 1 and 1 different commits each, respectively.
>> (use "git pull" to merge the remote branch into yours)
>>
>> nothing to commit, working tree clean
>
> So you're amending merge commit by adding dummy file, so that your
> `master` branch becomes divergent against origin. That dummy file isn't
> contained in any commits that are included with that merge commit.
What you probably didn't notice is that the new commit has no parents,
that is, it formed a new orphaned branch. The expected behavior is
amending the top commit and keeping it connected to the previous branch.
