'
+test_expect_success 'setup branch sub' '
+ git checkout --orphan sub &&
+ git rm -rf . &&
+ test_commit foo
+'
+
+test_expect_success 'setup branch main' '
+ git checkout -b main master &&
+ git merge -s ours --no-commit --allow-unrelated-histories sub &&
+ git read-tree --prefix=dir/ -u sub &&
+ git commit -m "initial merge of sub into main" &&
+ test_path_is_file dir/foo.t &&
+ test_path_is_file hello
+'
+
+test_expect_success 'update branch sub' '
+ git checkout sub &&
+ test_commit bar
+'
+
+test_expect_success 'update branch main' '
+ git checkout main &&
+ git merge -s subtree sub -m "second merge of sub into main" &&
+ test_path_is_file dir/bar.t &&
+ test_path_is_file dir/foo.t &&
+ test_path_is_file hello
+'
+
test_expect_success 'setup' '
mkdir git-gui &&
cd git-gui &&