patch 8.2.3423: Vim9: list += list creates a new list in :def function Commit: https://github.com/vim/vim/commit/07802044b90b2cbcc64b2dfe235f019d7c37589c Author: Bram Moolenaar <Bram@vim.org> Date: Thu Sep 9 23:01:14 2021 +0200 patch 8.2.3423: Vim9: list += list creates a new list in :def function Problem: Vim9: list += list creates a new list in :def function. Solution: Append to the existing list.

" Settings for test script execution
" Always use "COMMAND.COM", don't use the value of "$SHELL".
set shell=c:\COMMAND.COM shellquote= shellxquote= shellcmdflag=/c shellredir=>
" This is used only when the +eval feature is available.
if executable("cmd.exe")
   set shell=cmd.exe
endif

source setup.vim