Backport pull request #12443 from jellyfin/release-10.9.z

Check attachment path for null before use

Original-merge: 122da8f447

Merged-by: Bond-009 <bond.009@outlook.com>

Backported-by: Joshua M. Boniface <joshua@boniface.me>

MediaBrowser.MediaEncoding/Attachments/AttachmentExtractor.cs

@@ -89,7 +89,8 @@ namespace MediaBrowser.MediaEncoding.Attachments
             string outputPath,
             CancellationToken cancellationToken)
         {
-            var shouldExtractOneByOne = mediaSource.MediaAttachments.Any(a => a.FileName.Contains('/', StringComparison.OrdinalIgnoreCase) || a.FileName.Contains('\\', StringComparison.OrdinalIgnoreCase));
+            var shouldExtractOneByOne = mediaSource.MediaAttachments.Any(a => !string.IsNullOrEmpty(a.FileName)
+                                                                              && (a.FileName.Contains('/', StringComparison.OrdinalIgnoreCase) || a.FileName.Contains('\\', StringComparison.OrdinalIgnoreCase)));
             if (shouldExtractOneByOne)
             {
                 var attachmentIndexes = mediaSource.MediaAttachments.Select(a => a.Index);