merge: handle --ff/--no-ff/--ff-only as a tri-state option

diff --git a/t/t7600-merge.sh b/t/t7600-merge.sh
index 460d8ebf48f9ab3826e58e2e9285f6faecd79b78..3ff5fb853c941586e3e5ed69a74a628dfe5bb84a 100755 (executable)
--- a/t/t7600-merge.sh
+++ b/t/t7600-merge.sh
@@ -497,9 +497,15 @@ test_expect_success 'combining --squash and --no-ff is refused' '
        test_must_fail git merge --no-ff --squash c1
 '
 
-test_expect_success 'combining --ff-only and --no-ff is refused' '
-       test_must_fail git merge --ff-only --no-ff c1 &&
-       test_must_fail git merge --no-ff --ff-only 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
+'
+
+test_expect_success 'option --ff-only overwrites merge.ff=only config' '
+       git reset --hard c0 &&
+       test_config merge.ff only &&
+       git merge --no-ff c1
 '
 
 test_expect_success 'merge c0 with c1 (ff overrides no-ff)' '