commit https://github.com/vim/vim/commit/0ba75a9714884895b2ac09733158c47544a8dfb9 Author: Bram Moolenaar <Bram@vim.org> Date: Fri Feb 19 23:21:26 2016 +0100 patch 7.4.1360 Problem: Can't remove a callback with ch_setoptions(). Solution: When passing zero or an empty string remove the callback.

Test if fnameescape is correct for special chars like !

STARTTEST
:so small.vim
:%d
:let fname = 'Xspa ce'
:try | exe "w! " . fnameescape(fname) | put='Space' | endtry 
:let fname = 'Xemark!'
:try | exe "w! " . fnameescape(fname) | put='ExclamationMark' | endtry
:w! test.out
:qa!
ENDTEST