test_must_fail git merge --no-ff --squash c1
'
+test_expect_success 'combining --squash and --commit is refused' '
+ git reset --hard c0 &&
+ test_must_fail git merge --squash --commit c1 &&
+ test_must_fail git merge --commit --squash c1
+'
+
test_expect_success 'option --ff-only overwrites --no-ff' '
git merge --no-ff --ff-only c1 &&
test_must_fail git merge --no-ff --ff-only c2