Keep open fold open on `o`

Question

I have a file with foldmethod=indent. I have the folds automatically open when I enter them, and close when I leave them. When I sit in Normal mode on the bottom line of a fold and press o, the fold closes and I can't see what is in it.

I want Vim to understand that when I'm in a fold and type a command that leaves the fold but enters Insert mode, I want that fold to stay open.

Answer 1

It seems like the indent fold method has some flaws, and this is one of them. My solution might not be the best, but here it is:

I created my own fold implementation in my vimrc:

function! FoldLevel(lnum)
    return ( max([
        \     indent(prevnonblank(a:lnum)),
        \     indent(nextnonblank(a:lnum))
        \ ]) / getbufvar('.', '&tabstop', 1) )
endfunction


set foldmethod=expr
set foldexpr=FoldLevel(v:lnum)

You just need to put that in your .vimrc, and you should be good to go!