Block song exports

openlp/core/lib/db.py

@@ -358,7 +358,10 @@ class Manager(object):
 
     def delete_all_objects(self, object_class, filter_clause=None):
         """
-        Delete all object records
+        Delete all object records.
+        This method should only be used for simple tables and not ones with
+        relationships.  The relationships are not deleted from the database and
+        this will lead to database corruptions.
 
         ``object_class``
             The type of object to delete

openlp/plugins/songs/forms/songexportform.py

@@ -252,6 +252,9 @@ class SongExportForm(OpenLPWizard):
         songs = self.plugin.manager.get_all_objects(Song)
         songs.sort(cmp=locale.strcoll, key=lambda song: song.title.lower())
         for song in songs:
+            # No need to export temporary songs.
+            if song.temporary:
+                continue
             authors = u', '.join([author.display_name
                 for author in song.authors])
             title = u'%s (%s)' % (unicode(song.title), authors)