fix: fix reverse range in character class error

[tido64]

Description

vim.fn.expand seems to be interpreting brackets ([]) as something special. Escape the filename before trying to expand.

Fixes #2233
Fixes #2315

Type of change

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

How Has This Been Tested?

Create files with brackets in the filename, e.g. [2023-01-23] Test.md, and try previewing it.

Configuration:

• Neovim version (nvim --version):

NVIM v0.8.2
Build type: Release
LuaJIT 2.1.0-beta3
Compiled by brew@Ventura

Features: +acl +iconv +tui
See ":help feature-compile"

   system vimrc file: "$VIM/sysinit.vim"
  fall-back for $VIM: "/usr/local/Cellar/neovim/0.8.2/share/nvim"

Run :checkhealth for more info

• Operating system and version: macOS Ventura 13.1

Checklist:

• My code follows the style guidelines of this project (stylua)
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (lua annotations)

[Conni2461]

thanks for fixing this :)

i tried to debug it in #1584 but never really got the required information, so thanks for doing that for me :)

[tido64]

thanks for fixing this :)

i tried to debug it in #1584 but never really got the required information, so thanks for doing that for me :)

Thanks for reviewing!