patch 8.1.0573: cannot redefine user command without ! in same script commit https://github.com/vim/vim/commit/55d46913084745a48749d7ac4f48930852e1d87e Author: Bram Moolenaar <Bram@vim.org> Date: Sat Dec 8 16:03:28 2018 +0100 patch 8.1.0573: cannot redefine user command without ! in same script Problem: Cannot redefine user command without ! in same script Solution: Allow redefining user command without ! in same script, like with functions.

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