Saving empty .py file in multi root workspace crashes isort.

[rob-steele-active]

If I open a multi root workspace and save a file it usually works fine.

If I happen to save an empty file VSCode hangs and displays getting code actions from 'isort'. There are a few things that need to happen for this to break it seems.

1. The file has to be empty. Any python code or comments will prevent this bug from occurring.
2. Must be in a multi root workspace.
3. Must save the empty file.

After this no import organization will work until VSCode is restarted.

Granted this is not going to be a common issue. But I thought it was worth bringing attention to.

https://github.com/rob-steele-active/isort-bug-repro

[karthiknadig]

Thanks for the repro project. I will investigate what is going on with this.