commit https://github.com/vim/vim/commit/f5a39447a8ebe162ee62caa2ee502cd0e65eecaa Author: Bram Moolenaar <Bram@vim.org> Date: Tue Aug 16 21:04:41 2016 +0200 patch 7.4.2219 Problem: Recursive call to substitute gets stuck in sandbox. (Nikolai Pavlov) Solution: Handle the recursive call. (Christian Brabandt, closes https://github.com/vim/vim/issues/950) Add a test.

" Tests for Visual mode.  Uses double-wide character.
if !has('multi_byte')
  finish
endif

if !has('visual')
  finish
endif

func Test_block_shift_multibyte()
  split
  call setline(1, ['xヹxxx', 'ヹxxx'])
  exe "normal 1G0l\<C-V>jl>"
  call assert_equal('x	 ヹxxx', getline(1))
  call assert_equal('	ヹxxx', getline(2))
  q!
endfunc