patch 8.1.0768: updating completions may cause the popup menu to flicker commit https://github.com/vim/vim/commit/ae654385dfb2ae4c1d70789d1dce3676dba4dfbc Author: Bram Moolenaar <Bram@vim.org> Date: Thu Jan 17 21:09:05 2019 +0100 patch 8.1.0768: updating completions may cause the popup menu to flicker Problem: Updating completions may cause the popup menu to flicker. Solution: Avoid updating the text below the popup menu before drawing the popup menu.

"Test for benchmarking the RE engine

so small.vim
if !has("reltime") | finish | endif
func! Measure(file, pattern, arg)
	for re in range(3)
	    let sstart=reltime()
	    let cmd=printf("../vim -u NONE -N --cmd ':set re=%d'".
		\ " -c 'call search(\"%s\", \"\", \"\", 10000)' -c ':q!' %s", re, escape(a:pattern, '\\'), empty(a:arg) ? '' : a:arg)
	    call system(cmd. ' '. a:file)
	    $put =printf('file: %s, re: %d, time: %s', a:file, re, reltimestr(reltime(sstart)))
	endfor
endfunc