rebase -i: Add tests for "--edit-todo"

Signed-off-by: Andrew Wong <andrew.kw.w@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t3404-rebase-interactive.sh

@@ -911,4 +911,22 @@ test_expect_success 'rebase -i --root fixup root commit' '
 	test 0 = $(git cat-file commit HEAD | grep -c ^parent\ )
 '
 
+test_expect_success 'rebase --edit-todo does not works on non-interactive rebase' '
+	git reset --hard &&
+	git checkout conflict-branch &&
+	test_must_fail git rebase --onto HEAD~2 HEAD~ &&
+	test_must_fail git rebase --edit-todo &&
+	git rebase --abort
+'
+
+test_expect_success 'rebase --edit-todo can be used to modify todo' '
+	git reset --hard &&
+	git checkout no-conflict-branch^0 &&
+	FAKE_LINES="edit 1 2 3" git rebase -i HEAD~3 &&
+	FAKE_LINES="2 1" git rebase --edit-todo &&
+	git rebase --continue
+	test M = $(git cat-file commit HEAD^ | sed -ne \$p) &&
+	test L = $(git cat-file commit HEAD | sed -ne \$p)
+'
+
 test_done