vim-patch:7.4.901

Problem:    When a BufLeave autocommand changes folding in a way it syncs
            undo, undo can be corrupted.
Solution:   Prevent undo sync. (Jacob Niehus)

e7d1376b63

---

see: "[bug] [patch] Setting foldmethod in WinLeave autocommand can corrupt undo state"
     https://groups.google.com/d/msg/vim_dev/xF5uMLb1vwY/Jn4RglosDgAJ

src/nvim/version.c

@@ -387,7 +387,7 @@ static int included_patches[] = {
   // 904,
   // 903,
   // 902 NA
-  // 901,
+  901,
   // 900 NA
   // 899 NA
   898,