The fix for loading songs with linked audio. Fixes bug 1398403

Fixes: https://launchpad.net/bugs/1398403

openlp/core/lib/serviceitem.py

@@ -36,6 +36,7 @@ import html
 import logging
 import os
 import uuid
+import ntpath
 
 from PyQt4 import QtGui
 
@@ -423,8 +424,12 @@ class ServiceItem(RegistryProperties):
         if 'background_audio' in header:
             self.background_audio = []
             for filename in header['background_audio']:
-                # Give them real file paths
-                self.background_audio.append(os.path.join(path, filename))
+                # Give them real file paths.
+                filepath = filename
+                if path:
+                    # Windows can handle both forward and backward slashes, so we use ntpath to get the basename
+                    filepath = os.path.join(path, ntpath.basename(filename))
+                self.background_audio.append(filepath)
         self.theme_overwritten = header.get('theme_overwritten', False)
         if self.service_item_type == ServiceItemType.Text:
             for slide in service_item['serviceitem']['data']: