patch 8.0.1432: after ":copen" can't get the window-ID of the quickfix window commit https://github.com/vim/vim/commit/2ec364e94dbc080ccdf6c5dfc6f1653b5b7ded64 Author: Bram Moolenaar <Bram@vim.org> Date: Sat Jan 27 11:52:13 2018 +0100 patch 8.0.1432: after ":copen" can't get the window-ID of the quickfix window Problem: After ":copen" can't get the window-ID of the quickfix window. (FalacerSelene) Solution: Make it work without a quickfix list. Add a test. (Yegappan Lakshmanan, closes #2541)

function Test_Comparators()
  try
    let oldisident=&isident
    set isident+=#
    call assert_equal(1, 1 is#1)
  finally
    let &isident=oldisident
  endtry
endfunction