fix: preserve countdown dates and restore ids

tests/test_countdowns.py

@@ -84,6 +84,35 @@ def test_lunar_countdown_crud_validation_and_display(client):
     assert create_countdown(client, calendar_mode="solar", lunar_month=8, lunar_day=4).status_code == 422
 
 
+def test_editing_only_lunar_countdown_title_preserves_original_lunar_year(client):
+    boot(client)
+    created = create_countdown(
+        client,
+        title="农历纪念日",
+        event_date="2001-01-01",
+        calendar_mode="lunar",
+        lunar_month=12,
+        lunar_day=20,
+    )
+    assert created.status_code == 201
+    before = created.json()
+    assert before["event_date"] == "2002-02-01"
+    assert before["lunar_year"] == 2001
+
+    updated = client.patch(
+        f"/api/v1/countdowns/{before['id']}",
+        json={"title": "只修改标题"},
+    )
+
+    assert updated.status_code == 200
+    after = updated.json()
+    assert after["title"] == "只修改标题"
+    assert after["event_date"] == before["event_date"]
+    assert after["lunar_year"] == before["lunar_year"]
+    assert after["lunar_month"] == before["lunar_month"]
+    assert after["lunar_day"] == before["lunar_day"]
+
+
 def test_countdown_crud_single_pin_archive_restore_and_purge(client):
     boot(client)
     first = create_countdown(client).json()
@@ -188,3 +217,51 @@ def test_countdowns_backup_replace_and_merge_round_trip(client):
     assert [item["title"] for item in all_active].count("周年") == 1
     assert sum(item["pinned"] for item in all_active) == 1
     assert active["title"] == "周年"
+
+
+def test_countdown_backup_merge_remaps_ids_owned_by_another_user(client):
+    boot(client)
+    original = create_countdown(client, title="跨账号纪念日").json()
+    exported = client.get("/api/v1/export").json()
+
+    client.post("/api/v1/auth/logout")
+    from backend.auth import hash_password
+    from backend.db import get_db
+    from backend.models import TaskList, User
+
+    async def add_other_user():
+        db_gen = get_db()
+        db = await anext(db_gen)
+        try:
+            other = User(username="other", password_hash=hash_password("correct horse battery staple"))
+            db.add(other)
+            await db.flush()
+            db.add(TaskList(user_id=other.id, name="收集箱", is_inbox=True))
+            await db.commit()
+        finally:
+            await db_gen.aclose()
+
+    client.portal.call(add_other_user)
+    assert client.post(
+        "/api/v1/auth/login",
+        json={"username": "other", "password": "correct horse battery staple"},
+    ).status_code == 200
+
+    restored = client.post("/api/v1/restore", params={"mode": "merge"}, json=exported)
+
+    assert restored.status_code == 200
+    items = client.get("/api/v1/countdowns").json()
+    assert len(items) == 1
+    assert items[0]["title"] == "跨账号纪念日"
+    assert items[0]["id"] != original["id"]
+
+    merged_again = client.post("/api/v1/restore", params={"mode": "merge"}, json=exported)
+    assert merged_again.status_code == 200
+    assert len(client.get("/api/v1/countdowns").json()) == 1
+
+    exported_by_other = client.get("/api/v1/export").json()
+    restored_again = client.post("/api/v1/restore", params={"mode": "replace"}, json=exported_by_other)
+    assert restored_again.status_code == 200
+    replaced = client.get("/api/v1/countdowns").json()
+    assert len(replaced) == 1
+    assert replaced[0]["id"] == items[0]["id"]