When no milestones are defined in a project, selecting the burndown tab results in a traceback. This should be fixed to display something useful, or at least not crash trac.
Code fragment:
168. data['draw_graph'] = req.hdf['draw_graph'] = True
169. self.update_burndown_data()
170.
171. data['burndown_data'] = req.hdf['burndown_data'] = []
172. data['burndown_data'] = req.hdf['burndown_data'] = self.get_burndown_data(db, selected_milestone, components, selected_component)
173.
174. add_stylesheet(req, 'hw/css/burndown.css')
175.
176. self.update_burndown_data()
177.