From d8552c03165aaccbe177fd9da7125cfe45b07fab Mon Sep 17 00:00:00 2001
From: Oleg Broytman <phd@phdru.name>
Date: Sun, 20 Aug 2017 04:02:24 +0300
Subject: [PATCH] .vim: Add SetExecutableBit based on Tip 212

---
 .vim/ftplugin/python.vim |  8 +-------
 .vimrc                   | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/.vim/ftplugin/python.vim b/.vim/ftplugin/python.vim
index 2aa92b0..bc1f672 100644
--- a/.vim/ftplugin/python.vim
+++ b/.vim/ftplugin/python.vim
@@ -39,14 +39,8 @@ function! SavePython()
       if ext != "py"
          !rm -f %[co]
       endif
-      if executable(expand('%:p')) || !executable('chmod')
-        return
-      endif
       if getline(1) =~ "^#!"
-         !chmod +x %
-         if v:shell_error
-            echoerr 'Cannot make file executable: ' . v:shell_error
-         endif
+         call SetExecutableBit(1)
       endif
    endif
 endfunction
diff --git a/.vimrc b/.vimrc
index df1a9ee..470a800 100644
--- a/.vimrc
+++ b/.vimrc
@@ -581,6 +581,29 @@ END_OF_PYTHON
 endif
 
 
+" From Tip 212:
+" http://vim.wikia.com/wiki/Setting_file_attributes_without_reloading_a_buffer
+
+function! SetExecutableBit(x)
+   if !executable('chmod')
+      return
+   endif
+   checktime
+   let fname = expand("%:p")
+   execute "au FileChangedShell " . fname . " :echo"
+   if a:x
+      silent !chmod a+x %
+   else
+      silent !chmod a-x %
+   endif
+   if v:shell_error
+      echoerr 'Error running chmod: ' . v:shell_error
+   endif
+   checktime
+   execute "au! FileChangedShell " . fname
+endfunction
+command! Xbit if executable(expand("%:p")) | call SetExecutableBit(0) | else | call SetExecutableBit(1) | endif
+
 " ----------
 " From http://slobin.pp.ru/vim/_vimrc.html
 
-- 
2.39.2