Extract media attachment one by one if the filename appears to be a path (#11812)

MediaBrowser.MediaEncoding/Attachments/AttachmentExtractor.cs

@@ -88,6 +88,18 @@ namespace MediaBrowser.MediaEncoding.Attachments
             MediaSourceInfo mediaSource,
             string outputPath,
             CancellationToken cancellationToken)
+        {
+            var shouldExtractOneByOne = mediaSource.MediaAttachments.Any(a => a.FileName.Contains('/', StringComparison.OrdinalIgnoreCase) || a.FileName.Contains('\\', StringComparison.OrdinalIgnoreCase));
+            if (shouldExtractOneByOne)
+            {
+                var attachmentIndexes = mediaSource.MediaAttachments.Select(a => a.Index);
+                foreach (var i in attachmentIndexes)
+                {
+                    var newName = Path.Join(outputPath, i.ToString(CultureInfo.InvariantCulture));
+                    await ExtractAttachment(inputFile, mediaSource, i, newName, cancellationToken).ConfigureAwait(false);
+                }
+            }
+            else
             {
                 using (await _semaphoreLocks.LockAsync(outputPath, cancellationToken).ConfigureAwait(false))
                 {
@@ -101,6 +113,7 @@ namespace MediaBrowser.MediaEncoding.Attachments
                     }
                 }
             }
+        }
 
         public async Task ExtractAllAttachmentsExternal(
             string inputArgument,