commit https://github.com/vim/vim/commit/e59215c7dcae17b03daf39517560cfaa03314f5a Author: Bram Moolenaar <Bram@vim.org> Date: Sun Aug 14 19:08:45 2016 +0200 patch 7.4.2212 Problem: Mark " is not set when closing a window in another tab. (Guraga) Solution: Check all tabs for the window to be valid. (based on patch by Hirohito Higashi, closes https://github.com/vim/vim/issues/974)

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