patch 8.0.1225: no check for spell region being zero commit https://github.com/vim/vim/commit/ee03b941241eae1d36bc29b84eec09116cefe7cd Author: Bram Moolenaar <Bram@vim.org> Date: Fri Oct 27 00:57:05 2017 +0200 patch 8.0.1225: no check for spell region being zero Problem: No check for spell region being zero. (geeknik) Solution: Check for zero. (closes https://github.com/vim/vim/issues/2252)

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