serve dlna: remove file extensions from titles to prevent Samsung TV duplication

Samsung TVs have a bug where they duplicate file extensions when both
the title contains an extension and the MIME type indicates the same
file type. For example, "photo.jpg" becomes "photo.jpg.jpg".

Remove extensions from <dc:title> while keeping them in the resource URL
and MIME type. This provides a cleaner display and prevents Samsung TVs
from incorrectly "fixing" what they perceive as missing extensions.

cmd/serve/dlna/cds.go

@@ -80,7 +80,9 @@ func (cds *contentDirectoryService) cdsObjectToUpnpavObject(cdsObject object, fi
 	}
 
 	obj.Class = "object.item." + mediaType[1] + "Item"
-	obj.Title = fileInfo.Name()
+	// Remove file extension from title to prevent Samsung TVs from duplicating it
+	// File type is already provided via MIME type in protocolInfo
+	obj.Title = strings.TrimSuffix(fileInfo.Name(), filepath.Ext(fileInfo.Name()))
 	obj.Date = upnpav.Timestamp{Time: fileInfo.ModTime()}
 
 	item := upnpav.Item{

cmd/serve/dlna/cds_test.go

@@ -3,7 +3,9 @@ package dlna
 import (
 	"context"
 	"encoding/xml"
+	"path/filepath"
 	"sort"
+	"strings"
 	"testing"
 
 	"github.com/anacrolix/dms/soap"
@@ -176,6 +178,49 @@ func TestSOAPResponseQuoteEscaping(t *testing.T) {
 	assert.Contains(t, resultStr, """, "SOAP arguments should contain " entities")
 }
 
+func TestTitleExtensionRemoval(t *testing.T) {
+	// Test that file extensions are removed from titles to prevent Samsung TV duplication
+	tests := []struct {
+		name     string
+		filename string
+		expected string
+	}{
+		{
+			name:     "image file",
+			filename: "photo.jpg",
+			expected: "photo",
+		},
+		{
+			name:     "video file",
+			filename: "movie.mp4",
+			expected: "movie",
+		},
+		{
+			name:     "multiple dots",
+			filename: "file.name.with.dots.mkv",
+			expected: "file.name.with.dots",
+		},
+		{
+			name:     "no extension",
+			filename: "filename_no_ext",
+			expected: "filename_no_ext",
+		},
+		{
+			name:     "hidden file",
+			filename: ".hidden.txt",
+			expected: ".hidden",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Simulate the title processing logic
+			title := strings.TrimSuffix(tt.filename, filepath.Ext(tt.filename))
+			assert.Equal(t, tt.expected, title)
+		})
+	}
+}
+
 func TestAdjustXMLApostrophes(t *testing.T) {
 	tests := []struct {
 		name     string