Fix disabled source

Author: VictoriousRaptor

Plugins/Flow.Launcher.Plugin.Program/Programs/UWP.cs

@@ -277,7 +277,8 @@ public override int GetHashCode()
         [Serializable]
         public class Application : IProgram
         {
-            public string UniqueIdentifier { get; set; }
+            private string _uid = string.Empty;
+            public string UniqueIdentifier { get => _uid; set => _uid = value == null ? string.Empty : value.ToLowerInvariant(); }
             public string DisplayName { get; set; }
             public string Description { get; set; }
             public string UserModelId { get; set; }

Plugins/Flow.Launcher.Plugin.Program/Programs/Win32.cs

@@ -23,7 +23,7 @@ namespace Flow.Launcher.Plugin.Program.Programs
     public class Win32 : IProgram, IEquatable<Win32>
     {
         public string Name { get; set; }
-        public string UniqueIdentifier { get => _uid; set => _uid = value.ToLowerInvariant(); }  // For path comparison
+        public string UniqueIdentifier { get => _uid; set => _uid = value == null ? string.Empty : value.ToLowerInvariant(); }  // For path comparison
         public string IcoPath { get; set; }
         public string FullPath { get; set; }
         public string LnkResolvedPath { get; set; }

Plugins/Flow.Launcher.Plugin.Program/Views/Models/ProgramSource.cs

@@ -16,36 +16,36 @@ namespace Flow.Launcher.Plugin.Program.Views.Models
     public class ProgramSource
     {
         private string name;
+        private string loc = string.Empty;
+        private string uniqueIdentifier = string.Empty;
 
-        private string loc;
         public string Location
         {
             get => loc;
             set
             {
-                loc = value;
-                UniqueIdentifier = value.ToLowerInvariant();
+                loc = value ?? string.Empty;
+                UniqueIdentifier = value;
             }
         }
+
         public string Name { get => name ?? new DirectoryInfo(Location).Name; set => name = value; }
         public bool Enabled { get; set; } = true;
 
-        public string UniqueIdentifier { get; private set; }
+        public string UniqueIdentifier { get => uniqueIdentifier; 
+            private set
+            {
+                uniqueIdentifier = value == null ? string.Empty : value.ToLowerInvariant();
+            } 
+        }
 
         [JsonConstructor]
         public ProgramSource(string name, string location, bool enabled, string uniqueIdentifier)
         {
-            loc = location;
+            loc = location ?? string.Empty;
             this.name = name;
             Enabled = enabled;
-            if (location.Equals(uniqueIdentifier, StringComparison.OrdinalIgnoreCase))
-            {
-                UniqueIdentifier = location.ToLowerInvariant();  // To make sure old config can be reset to case-insensitive
-            }
-            else
-            {
-                UniqueIdentifier = uniqueIdentifier;  // For uwp apps
-            }
+            UniqueIdentifier = uniqueIdentifier;
         }
 
         /// <summary>
@@ -55,9 +55,9 @@ public ProgramSource(string name, string location, bool enabled, string uniqueId
         /// <param name="enabled">enabled</param>
         public ProgramSource(string location, bool enabled = true)
         {
-            loc = location;
+            loc = location ?? string.Empty;
             Enabled = enabled;
-            UniqueIdentifier = location.ToLowerInvariant();  // For path comparison
+            UniqueIdentifier = location;  // For path comparison
         }
 
         public ProgramSource(IProgram source)