Chain with a group of a single task

[edwardreed81]

The workflow I'm constructing is relatively simple:

A setup task that executes, followed by a group of tasks that depend on the result of the setup task:

run_tasks = [run_task(...).s() for task in tasks]
chain = setup_task(...).s() | group(run_tasks)
chain.apply_async()

This works fine when len(run_tasks) > 1, but when len(run_tasks) == 1, constructing the chain changes the second task in the chain to be a regular task, not a group. This means the result of apply_async() is a different type depending on the length of run_tasks. If it is length 1, the result is an AsyncResult, but if it is longer than 1, the result is a GroupResult. This causes a problem with saving and restoring the result.

Is this expected behavior? Seems like a group should remain a group no matter how many tasks are in it.