Hi and thanks for this awesome project!

I have been using the plenary.curl module recently, especially it's capability to stream http responses using the underlying plenary.job on_stdout mechanism.

While using it, I discovered a few weired edge-cases where the last chunks of streamed data is only available via job:result(), but not the on_stdout callback.

Looking at the tests I found two related test cases that are marked as pending, so it seems like this has been a known issue.

As this is unnecessarily complicating my usage of the plenary.curl streaming functionality, as I would have to use both on_stdout and then at the end compare what has not yet been processed from the job:result(), I would like to resolve this bug.

Please let me know if I have misunderstood anything or you have further thoughts.
I will open a PR with a potential solution.

Thanks a lot!