src/testdir/test_modeline.vim

" Tests for parsing the modeline.

func Test_modeline_invalid()
  " This was reading before allocated memory.
  call writefile(['vi:0', 'nothing'], 'Xmodeline')
  call assert_fails('split Xmodeline', 'E518:')
  bwipe!
  call delete('Xmodeline')
endfunc