commit https://github.com/vim/vim/commit/ad5ca9bc1e7145474adb082775a805f1731e9e37 Author: Bram Moolenaar <Bram@vim.org> Date: Mon Jun 20 21:26:08 2016 +0200 patch 7.4.1948 Problem: Using Ctrl-A with double-byte encoding may result in garbled text. Solution: Skip to the start of a character. (Hirohito Higashi)

" For Yiddish capitals should not be checked.  But only change the
" 'spellcapcheck' option when it is not at its default value.
let s:spc = &l:spc
setlocal spc&
if s:spc == &l:spc
  setlocal spc=
else
  let &l:spc = s:spc
endif
unlet s:spc