test_must_fail git notes show HEAD^
'
+test_expect_success 'show notes from treeish' '
+ test "b3" = "$(git notes --ref commits^{tree} show)" &&
+ test "b4" = "$(git notes --ref commits@{1} show)"
+'
+
+test_expect_success 'cannot edit notes from non-ref' '
+ test_must_fail git notes --ref commits^{tree} edit &&
+ test_must_fail git notes --ref commits@{1} edit
+'
+
test_expect_success 'cannot "git notes add -m" where notes already exists' '
test_must_fail git notes add -m "b2" &&
test_path_is_missing .git/NOTES_EDITMSG &&