From 4812e371b0351e50608e5a84551a2f1c4f4e3d62 Mon Sep 17 00:00:00 2001
From: ig <ig ig@devnullmail.com>
Date: Thu, 9 Mar 2023 10:52:31 +0100
Subject: [PATCH] Rewrite IsParentOfChild

---
 csharp/App/Backend/Database/Folder.cs |  1 -
 csharp/App/Backend/Database/User.cs   | 15 ++++-----------
 2 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/csharp/App/Backend/Database/Folder.cs b/csharp/App/Backend/Database/Folder.cs
index 8a4785639..0867b4e50 100644
--- a/csharp/App/Backend/Database/Folder.cs
+++ b/csharp/App/Backend/Database/Folder.cs
@@ -26,7 +26,6 @@ public partial class Db
         return Folders.Where(f => f.ParentId == parent.Id);
     }
     
-    
     public IEnumerable<Folder> GetDescendantFolders(Folder parent)
     {
         return parent.Traverse(GetChildFolders);
diff --git a/csharp/App/Backend/Database/User.cs b/csharp/App/Backend/Database/User.cs
index 682ecbc5b..22a65a0bd 100644
--- a/csharp/App/Backend/Database/User.cs
+++ b/csharp/App/Backend/Database/User.cs
@@ -30,17 +30,10 @@ public partial class Db
 
     public Boolean IsParentOfChild(User parent, User child)
     {
-        var parentPointer = child.ParentId;
-
-        if (parent.Id == child.Id)
-            return true;
-
-        while (parentPointer != null && parentPointer != parent.Id)
-        {
-            parentPointer = GetUserById(parentPointer).ParentId;
-        }
-
-        return parentPointer == parent.Id;
+        return child
+              .Unfold(u => GetUserById(u.ParentId))
+              .Select(u => u.Id)
+              .Contains(parent.Id);
     }
 
     public User? GetUserByEmail(String email) => Users.FirstOrDefault(u => u.Email == email);