Performance improvement when reversing the order of a column

svn: r14231

src/gui/views/treemodels/treebasemodel.py

@@ -647,6 +647,7 @@ class TreeBaseModel(gtk.GenericTreeModel):
                 path = self.on_get_path(node)
                 iter = self.get_iter(path)
             self.rows_reordered(path, iter, rows)
+            if self.nrgroups > 1:
                 for child in node.children:
                     self._reverse_level(self.nodemap.node(child[1]))