src/testdir/test_put.vim

func Test_put_block()
  if !has('multi_byte')
    return
  endif
  new
  call feedkeys("i\<C-V>u2500\<CR>x\<ESC>", 'x')
  call feedkeys("\<C-V>y", 'x')
  call feedkeys("gg0p", 'x')
  call assert_equal("\u2500x", getline(1))
  bwipe!
endfunc