t3418: test rebase -r with merge strategies

There is a test case in this script that verifies that `git rebase
--preserve-merges` works all right with non-default merge strategies or
non-default merge strategy options.

Now that `git rebase --rebase-merges` learned about merge strategies,
let's copy-edit this test case to verify that that works as intended,
too.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t3418-rebase-continue.sh

@@ -120,6 +120,20 @@ test_expect_success REBASE_P 'rebase passes merge strategy options correctly' '
 	git rebase --continue
 '
 
+test_expect_success 'rebase -r passes merge strategy options correctly' '
+	rm -fr .git/rebase-* &&
+	git reset --hard commit-new-file-F3-on-topic-branch &&
+	test_commit merge-theirs &&
+	git reset --hard HEAD^ &&
+	test_commit some-other-commit &&
+	test_tick &&
+	git merge --no-ff merge-theirs &&
+	FAKE_LINES="1 3 edit 4 5 7 8 9" git rebase -i -f -r -m \
+		-s recursive --strategy-option=theirs HEAD~2 &&
+	test_commit force-change-ours &&
+	git rebase --continue
+'
+
 test_expect_success '--skip after failed fixup cleans commit message' '
 	test_when_finished "test_might_fail git rebase --abort" &&
 	git checkout -b with-conflicting-fixup &&