Prevent pfiletype from failing when bufname is nil

[pijusn]

Description

This is fixing an issue introduced in this commit.

A fresh install of NvChad fails with following error:

Error executing vim.schedule lua callback: ...scope.nvim/lua/telescope/previewers/buffer_previewer.lua:428: Error executing lua: ...al/share/nvim/lazy/plenary.nvim/lua/plenary/filetype.lua:55: attempt to index l
ocal 'filename' (a nil value)
stack traceback:
        ...al/share/nvim/lazy/plenary.nvim/lua/plenary/filetype.lua:55: in function '_get_extension_parts'
        ...al/share/nvim/lazy/plenary.nvim/lua/plenary/filetype.lua:103: in function 'detect_from_extension'
        ...al/share/nvim/lazy/plenary.nvim/lua/plenary/filetype.lua:168: in function 'detect'
        ...scope.nvim/lua/telescope/previewers/buffer_previewer.lua:434: in function <...scope.nvim/lua/telescope/previewers/buffer_previewer.lua:428>
        [C]: in function 'nvim_buf_call'
        ...scope.nvim/lua/telescope/previewers/buffer_previewer.lua:428: in function <...scope.nvim/lua/telescope/previewers/buffer_previewer.lua:422>
stack traceback:
        [C]: in function 'nvim_buf_call'
        ...scope.nvim/lua/telescope/previewers/buffer_previewer.lua:428: in function <...scope.nvim/lua/telescope/previewers/buffer_previewer.lua:422>

Maybe there is a cleaner way to do this but this is a quick and defensive solution to the problem. If you want to fix it differently, it's OK.

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

To reproduce it:

1. Setup a fresh NvChad install.
2. Run nvim.
3. Wait for Lazy to install the plugins (it takes latest of telescope.nvim).
4. Quit the editor, as instructed.
5. Run nvim.
6. Type <leader>th to open theme editor (it runs buffer_previewer logic).
7. 💥

Configuration:

NVIM v0.9.0
Build type: Release
LuaJIT 2.1.0-beta3

MacOS 13.2.1

[pijusn]

@akinsho you might have the necessary context to decide whether this patch or a different change is more appropriate.

[Conni2461]

thanks :) can you fix stylua ci after that i would merge

[Conni2461]

thanks :)