patch 8.0.1831: sometimes the quickfix title is incorrectly prefixed with ':' commit https://github.com/vim/vim/commit/8b62e31003693fee4b288e7aea49170f032aeef3 Author: Bram Moolenaar <Bram@vim.org> Date: Sun May 13 15:29:04 2018 +0200 patch 8.0.1831: sometimes the quickfix title is incorrectly prefixed with ':' Problem: Sometimes the quickfix title is incorrectly prefixed with ':'. Solution: Prepend the colon in another way. (Yegappan Lakshmanan, closes #2905)

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