Fixed not-initialised bug with NO tags in notes

If there were no tags whatsoever in the full list of notes, then the
TriggeredcompleteEntry completion list would not get set, resulting in
tracebacks during execution.

nvpy/view.py

@@ -579,7 +579,7 @@ def __init__(self, config, notes_list_model):
         utils.SubjectMixin.__init__(self)
 
         self.config = config
-        self.taglist = []
+        self.taglist = None
 
         notes_list_model.add_observer('set:list', self.observer_notes_list)
         self.notes_list_model = notes_list_model
@@ -1467,21 +1467,32 @@ def set_note_data(self, note, reset_undo=True, content_unchanged=False):
 
 
     def set_notes(self, notes):
+        # this method is called by View.observer_notes_list()
+
         # clear the notes list
         self.notes_list.clear()
         taglist = []
-        
+
         for o in notes:
             tags = o.note.get('tags')
             if tags:
                 taglist += tags
+
             self.notes_list.append(o.note, utils.KeyValueObject(tagfound=o.tagfound))
 
-        taglist = list(set(self.taglist + taglist))
-        if len(taglist) > len(self.taglist):
-            self.taglist=taglist
+        if self.taglist is None:
+            # first time we get called, so we need to initialise
+            self.taglist = taglist
             self.search_entry.set_completion_list(self.taglist)
 
+        else:
+            # only set completion list if the new combined taglist is larger.
+            taglist = list(set(self.taglist + taglist))
+            if len(taglist) > len(self.taglist):
+                self.taglist=taglist
+                self.search_entry.set_completion_list(self.taglist)
+
+
     def show_error(self, title, msg):
         tkMessageBox.showerror(title, msg)