do not throw ArgumentNullException in TryCleanString

Emby.Naming/Video/CleanStringParser.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Text.RegularExpressions;
 
 namespace Emby.Naming.Video
@@ -16,7 +17,7 @@ namespace Emby.Naming.Video
         /// <param name="expressions">List of regex to parse name and year from.</param>
         /// <param name="newName">Parsing result string.</param>
         /// <returns>True if parsing was successful.</returns>
-        public static bool TryClean(string name, IReadOnlyList<Regex> expressions, out ReadOnlySpan<char> newName)
+        public static bool TryClean(string name, IReadOnlyList<Regex> expressions, [NotNullWhen(true)] out ReadOnlySpan<char> newName)
         {
             var len = expressions.Count;
             for (int i = 0; i < len; i++)
@@ -31,8 +32,14 @@ namespace Emby.Naming.Video
             return false;
         }
 
-        private static bool TryClean(string name, Regex expression, out ReadOnlySpan<char> newName)
+        private static bool TryClean(string name, Regex expression, [NotNullWhen(true)] out ReadOnlySpan<char> newName)
         {
+            if (string.IsNullOrEmpty(name))
+            {
+                newName = null;
+                return false;
+            }
+
             var match = expression.Match(name);
             int index = match.Index;
             if (match.Success && index != 0)

Emby.Naming/Video/VideoResolver.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Linq;
 using Emby.Naming.Common;
@@ -146,7 +147,7 @@ namespace Emby.Naming.Video
         /// <param name="name">Raw name.</param>
         /// <param name="newName">Clean name.</param>
         /// <returns>True if cleaning of name was successful.</returns>
-        public bool TryCleanString(string name, out ReadOnlySpan<char> newName)
+        public bool TryCleanString(string name, [NotNullWhen(true)] out ReadOnlySpan<char> newName)
         {
             return CleanStringParser.TryClean(name, _options.CleanStringRegexes, out newName);
         }

tests/Jellyfin.Naming.Tests/Video/CleanStringTests.cs

@@ -28,6 +28,7 @@ namespace Jellyfin.Naming.Tests.Video
         [InlineData("Crouching.Tiger.Hidden.Dragon.BDrip.mkv", "Crouching.Tiger.Hidden.Dragon")]
         [InlineData("Crouching.Tiger.Hidden.Dragon.BDrip-HDC.mkv", "Crouching.Tiger.Hidden.Dragon")]
         [InlineData("Crouching.Tiger.Hidden.Dragon.4K.UltraHD.HDR.BDrip-HDC.mkv", "Crouching.Tiger.Hidden.Dragon")]
+        [InlineData(null, null)]
         // FIXME: [InlineData("After The Sunset - [0004].mkv", "After The Sunset")]
         public void CleanStringTest(string input, string expectedName)
         {