Fix LP Bug #779074 - TypeError in on_key_press_event(): cannot concatenate 'str' and 'NoneType'

deluge/ui/gtkui/torrentview.py

@@ -567,6 +567,7 @@ class TorrentView(listview.ListView, component.Component):
     # Handle keyboard shortcuts
     def on_key_press_event(self, widget, event):
         keyname = gtk.gdk.keyval_name(event.keyval)
+        if keyname is not None:
             func = getattr(self, 'keypress_' + keyname, None)
             if func:
                 return func(event)