> Looking at the docstring, shell's C-u behavior seems pretty weird to me.
>
> Why would someone input an existing buffer this way, if they could just
> switch to it instead, with the same completion interface?

+1.

Also, if you choose an existing non-shell buffer, the one you are in for example, it will actually just turn that buffer into a shell buffer. That behavior should actually be a bug imo.

Theo