Sometimes I will forget to claim a task when I start working on it. This is often the case if I recognize that the task relates to some change that I had made recently and if the fix is trivial (although to someone else who may work on the task, the diagnosis may be time consuming and/or hard to reproduce).
It would be great if submitting a differential for a Maniphest task (particularly a `fixes` diff) automatically claimed the parent task as well. This would ensure that no-one else started working on the task that I had already fixed.