[Bug] Searching within a fold closes it

[akinsho]

Neovim version (nvim -v | head -n1)

NVIM v0.8.0-dev+1941-gb7084fef4

Operating system/version

macOS 12.4

How to reproduce the issue

1. Use the following init.lua via nvim -u <minimal-init> --no-plugin <file-with-folds>

vim.cmd("packadd! nvim-ufo")

vim.opt.termguicolors = true
vim.opt.foldlevelstart = 2
vim.opt.foldenable = true

require("ufo").setup()

2. go to a closed fold, open it with zo
3. search for any item within the fold using either :call search('thing') or /thing<CR>
4. Fold is closed

Expected behavior

Searching inside a folded area should not cause the fold to be closed

Actual behavior

Searching inside a folded area causes the fold to close back up

nvim-ufo-bug.mov

[kevinhwang91]

ufo listen CmdlineLeave to update the fold.
The issue is similar to #7
Set a large foldlevel value.

[kevinhwang91]

can be improved by checking the changedtick.