1 files changed, 36 insertions, 0 deletions
diff --git a/tests/rootfs_finalization.rs b/tests/rootfs_finalization.rs
index fa0cf3b..3a98290 100644
--- a/tests/rootfs_finalization.rs
+++ b/tests/rootfs_finalization.rs
@@ -79,3 +79,39 @@ fn finalization_rejects_rootfs_escaping_destinations_and_symlinks() {
         .expect_err("unsafe symlink must be rejected");
     assert!(error.to_string().contains("escapes copied tree"));
 }
+
+#[test]
+fn finalization_is_idempotent_for_matching_symlinks() {
+    let fixture = tempdir().expect("fixture directory");
+    let source = fixture.path().join("overlay");
+    fs::create_dir_all(&source).expect("create source tree");
+    symlink("controller.conf", source.join("controller-link")).expect("create source symlink");
+    fs::write(source.join("controller.conf"), "controller\n").expect("write source file");
+    let rootfs = tempdir().expect("rootfs directory");
+    let finalization = RootfsFinalization::new(
+        vec![CopyTree::new(&source, "etc/controller").expect("valid copy destination")],
+        InitrdOem::new(std::iter::empty::<&str>(), std::iter::empty::<&str>()),
+        vec![ServiceName::new("chronyd.service").expect("valid service")],
+    );
+
+    finalization.apply(rootfs.path()).expect("first finalization succeeds");
+    let second = finalization.apply(rootfs.path()).expect("repeat finalization succeeds");
+
+    assert_eq!(
+        fs::read_link(rootfs.path().join("etc/controller/controller-link")).expect("copied symlink"),
+        Path::new("controller.conf")
+    );
+    assert_eq!(
+        fs::read_link(
+            rootfs
+                .path()
+                .join("etc/systemd/system/multi-user.target.wants/chronyd.service")
+        )
+        .expect("enabled service"),
+        Path::new("/usr/lib/systemd/system/chronyd.service")
+    );
+    assert!(second
+        .created_paths()
+        .iter()
+        .any(|path| path == "etc/controller/controller-link"));
+}