counterexample.txt

git init foo
cd foo

touch this that
git add .
git commit -m '1 master'

git checkout -b feature
echo 'feature' > this
git commit -a -m '1 feature'

git checkout master
echo 'master' > that
git commit -a -m '2 master'

git merge -m 'Merge feature' feature

echo 'master 2' >> that
git commit -a -m '3 master after merge'

# but now...
echo 'feature 2' >> this
git commit -a -m '4 master two after merge'

cat this that
# feature
# feature 2
# master
# master 2

git rebase -i HEAD^^^^
# remove feature 1

# CONFLICT (content): Merge conflict in this
# so we edit this:
# <<<<<<< HEAD
# =======
# feature
# feature 2
# >>>>>>> c84fea8... 4 master two after merge
# what to do? well, we _might_ wish to keep the content
# let's do that

git add this
git rebase --continue

cat this that
# feature
# feature 2
# master
# master 2