From 56480c7c0a60d175e981409a2989acd0c92a929b Mon Sep 17 00:00:00 2001
From: bakerboy448 <55419169+bakerboy448@users.noreply.github.com>
Date: Fri, 5 Sep 2025 09:41:27 -0500
Subject: [PATCH] Fixed: Null Tag Handling

---
 .../Identification/DistanceFixture.cs         | 24 +++++++++++++++++++
 .../TrackImport/Identification/Distance.cs    |  4 ++--
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/src/NzbDrone.Core.Test/MediaFiles/TrackImport/Identification/DistanceFixture.cs b/src/NzbDrone.Core.Test/MediaFiles/TrackImport/Identification/DistanceFixture.cs
index 8c0851f6d..c263a7e5a 100644
--- a/src/NzbDrone.Core.Test/MediaFiles/TrackImport/Identification/DistanceFixture.cs
+++ b/src/NzbDrone.Core.Test/MediaFiles/TrackImport/Identification/DistanceFixture.cs
@@ -163,5 +163,29 @@ public void test_raw_distance()
 
             dist.RawDistance().Should().Be(2.25);
         }
+
+        [Test]
+        public void test_add_string_null_handling()
+        {
+            var dist = new Distance();
+
+            dist.AddString("string", null, "target");
+            dist.Penalties.Should().BeEquivalentTo(new Dictionary<string, List<double>> { { "string", new List<double> { 1.0 } } });
+
+            dist.AddString("string2", "value", null);
+            dist.Penalties.Should().BeEquivalentTo(new Dictionary<string, List<double>>
+            {
+                { "string", new List<double> { 1.0 } },
+                { "string2", new List<double> { 1.0 } }
+            });
+
+            dist.AddString("string3", null, null);
+            dist.Penalties.Should().BeEquivalentTo(new Dictionary<string, List<double>>
+            {
+                { "string", new List<double> { 1.0 } },
+                { "string2", new List<double> { 1.0 } },
+                { "string3", new List<double> { 0.0 } }
+            });
+        }
     }
 }
diff --git a/src/NzbDrone.Core/MediaFiles/TrackImport/Identification/Distance.cs b/src/NzbDrone.Core/MediaFiles/TrackImport/Identification/Distance.cs
index 12fa48af2..63a9f5633 100644
--- a/src/NzbDrone.Core/MediaFiles/TrackImport/Identification/Distance.cs
+++ b/src/NzbDrone.Core/MediaFiles/TrackImport/Identification/Distance.cs
@@ -125,8 +125,8 @@ private static string Clean(string input)
         public void AddString(string key, string value, string target)
         {
             // Adds a penaltly based on the distance between value and target
-            var cleanValue = Clean(value);
-            var cleanTarget = Clean(target);
+            var cleanValue = Clean(value ?? string.Empty);
+            var cleanTarget = Clean(target ?? string.Empty);
 
             if (cleanValue.IsNullOrWhiteSpace() && cleanTarget.IsNotNullOrWhiteSpace())
             {