fix minor GTK warnings or typos

pycam/Plugins/ParameterGroupManager.py

@@ -169,7 +169,7 @@ class ParameterGroupManager(pycam.Plugins.PluginBase):
         changed_set_event = group["changed_set_event"]
         if changed_set_event:
             self.core.register_event(changed_set_event,
-                    self._update_widgets_visibility)
+                    self._update_widgets_visibility, group_name)
         del self._groups[group_name]
 
     def unregister_parameter_set(self, group_name, set_name):

pycam/Plugins/ToolpathProcessors.py

@@ -47,6 +47,7 @@ class ToolpathProcessors(pycam.Plugins.ListPluginBase):
                     # we need to clear the whole path down to the "real" item
                     parent = notebook
                     while not child in [entry[0] for entry in self._pref_items]:
+                        if child.get_parent():
                             parent.remove(child)
                         parent = child
                         try:

pycam/Plugins/__init__.py

@@ -446,6 +446,7 @@ class ListPluginBase(PluginBase, list):
                 treemodel.append((uuid, ))
         # reorder the treemodel according to the current list
         sorted_indices = [current_uuids.index(row[0]) for row in treemodel]
+        if sorted_indices:
             treemodel.reorder(sorted_indices)
         self.core.emit_event("tool-list-changed")