Neovim version (nvim -v)

0.5.0

Vim (not Nvim) behaves the same?

no, 8.2.2434

Operating system/version

any

Terminal name/version

any

$TERM environment variable

any

Installation

compiled from source

How to reproduce the issue

nvim -u NONE
:filetype plugin on
:setfiletype man
:new
:setfiletype man

Expected behavior

Two new empty unnamed buffers with 'filetype' set to man.

Actual behavior

First buffer is renamed to man://. Second buffer yields the error E95: Buffer with this name already exists. This also happens with named buffers, including files that already exist.

The E95 highlights how fragile this approach is, but even if it could be worked around, I don't want my buffers renamed when I change the file type. What if I just want the syntax highlighting? What if I fat finger :setf masm?