fix: cmdline flicker when cmdheight = 0

[Shougo]

I have fixed the screen flicker when cmdheight=0.

I don't know the clear is really needed.

@bfredl Can you check it?

[arsham]

I'm afraid it has the following issue: (status line vanishes)

The status line is feline, and here is the setup.

[Shougo]

It really need feline to reproduce the problem?
I think it doesn't depend on the plugins.
I will test it later.
Please test it without plugins.

[bfredl]

special casing p_ch = 0 seems weird. the goal is to special case it even less, not to add more extra logic. but before doing anything we need to setup test infrastructure to actually test redraw perf and flicker, otherwise we are just moving in circles.

[Shougo]

@arsham Please create the minimal init.vim like this.

set cmdheight=0
set rtp+=~/src/feline.nvim

set termguicolors

autocmd RecordingEnter * set cmdheight=1
autocmd RecordingLeave * set cmdheight=0

lua require('feline').setup()

I don't reproduce your issue.

[arsham]

I can confirm that this bug is not related to your code. I've found two plugins causing this issue: nvim-neorg/neorg and ldelossa/gh.nvim.

I apologise for making a scene here. I'm just being a fan of your work and I tried to share a potential issue and I was wrong!

[Shougo]

OK.