Is it correct to allow back to addtask_frag after saving the task?

When i finish a new task then in task list if i press back physical button return me to new task with data if save again duplicate the task. When i edit a task and press back button and i save the task apply the new changes

Is correct that navigation?
Because that doesn't allow to exit of the app until return all navigation

Start by reproducing the physical Back behavior after saving a new task and after editing a task, as described in the issue. Trace the task-list and new-task navigation entry points mentioned by the report. Done means Back does not reopen a saved form in a way that permits duplicate creation and can eventually exit the app.

Written by the indexing model from the issue text.