neovim: only set line number for actual file buffers

nvim/.config/nvim/init.vim

@@ -18,7 +18,6 @@ colorscheme gruvbox-material
 " Miscellaneous boilerplate
 set nocompatible " Disable vi compatibility
 set ignorecase
-set nu           " Line numbers
 set cc=80        " 80 characters
 set noswapfile
 set backupdir=~/.cache/nvim
@@ -35,5 +34,14 @@ set autoindent
 " Syntax highlighting
 set syntax=on
 
+" Show line numbers on non-toolbar buffers
+fun! ShowNumberIfNecessary()
+    if &ft =~ 'neo-tree'
+        return
+    endif
+    setlocal nu
+endfun
+autocmd BufEnter * call ShowNumberIfNecessary()
+
 " Startup commands
 autocmd UIEnter * Neotree