From a386e7c95eb6605878879e37405ba1aed94ab953 Mon Sep 17 00:00:00 2001
From: LazuliKao <lazulikao@nbt.edu.cn>
Date: Tue, 2 May 2023 14:15:49 +0800
Subject: [PATCH] fix crash on delete working dir

---
 src/LipUI/Global.cs | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/LipUI/Global.cs b/src/LipUI/Global.cs
index 18b4572..3786cef 100644
--- a/src/LipUI/Global.cs
+++ b/src/LipUI/Global.cs
@@ -412,10 +412,9 @@ void Save()
             void CollectionChangeHandler(object sender, NotifyCollectionChangedEventArgs e)
             {
                 Save();
-                foreach (var item in e.NewItems)
-                {
-                    Subscribe(item);
-                }
+                if (e.NewItems is not null)
+                    foreach (var item in e.NewItems)
+                        Subscribe(item);
             }
             void Subscribe(object? sub)
             {