commit https://github.com/vim/vim/commit/e59215c7dcae17b03daf39517560cfaa03314f5a Author: Bram Moolenaar <Bram@vim.org> Date: Sun Aug 14 19:08:45 2016 +0200 patch 7.4.2212 Problem: Mark " is not set when closing a window in another tab. (Guraga) Solution: Check all tabs for the window to be valid. (based on patch by Hirohito Higashi, closes https://github.com/vim/vim/issues/974)

" Test feedkeys() function.

func Test_feedkeys_x_with_empty_string()
  new
  call feedkeys("ifoo\<Esc>")
  call assert_equal('', getline('.'))
  call feedkeys('', 'x')
  call assert_equal('foo', getline('.'))

  " check it goes back to normal mode immediately.
  call feedkeys('i', 'x')
  call assert_equal('foo', getline('.'))
  quit!
endfunc