commit https://github.com/vim/vim/commit/6244a0fc29163ba1c734f92b55a89e01e6cf2a67 Author: Bram Moolenaar <Bram@vim.org> Date: Thu Apr 14 14:09:25 2016 +0200 patch 7.4.1729 Problem: The Perl interface cannot use 'print' operator for writing directly in standard IO. Solution: Add a minimal implementation of PerlIO Layer feature and try to use it for STDOUT/STDERR. (Damien)

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