commit https://github.com/vim/vim/commit/864293abb72d62604d8d6b458addfb43c14230c3 Author: Bram Moolenaar <Bram@vim.org> Date: Thu Jun 2 13:40:04 2016 +0200 patch 7.4.1871 Problem: Appending to the quickfix list while the quickfix window is open is very slow. Solution: Do not delete all the lines, only append the new ones. Avoid using a window while updating the list. (closes #841)

let encoding = &enc
if encoding == 'latin1'
    if has("unix")
	let encoding = 'iso-8859-2'
    else
	let encoding = 'cp1250'
    endif
endif

if encoding == 'utf-8'
	source <sfile>:p:h/slovak_utf-8.vim
elseif encoding == 'cp1250'
	source <sfile>:p:h/slovak_cp1250.vim
else
	source <sfile>:p:h/slovak_iso-8859-2.vim
endif