patch 8.2.3883: crash when switching to other regexp engine fails Commit: https://github.com/vim/vim/commit/5937c7505f444dd896f336fa0119a93a55ebe9a2 Author: Bram Moolenaar <Bram@vim.org> Date: Fri Dec 24 16:46:14 2021 +0000 patch 8.2.3883: crash when switching to other regexp engine fails Problem: Crash when switching to other regexp engine fails. Solution: Check for regprog being NULL.

" Provide 'PrintVer' command to print the interface versions.

func s:print_ver(lang, ...)
  if has(a:lang)
    exec a:lang join(a:000)
  else
    echo 'N/A'
  endif
  echo ''
endfunc

command -nargs=+ PrintVer call <SID>print_ver(<f-args>)